MEGA EMRCS Flashcards

Question

A 56 year old man with chronic obstructive pulmonary disease (COPD) is brought into A&E following sudden onset shortness of breath. A chest x-ray confirms a right sided pneumothorax. The chest wall-hilar measurement is 2.4cm. What is the SINGLE most appropriate management? A. Needle aspiration B. Cannula decompression C. Chest drain insertion D. Supplemental oxygen E. Pleurodesis

Answer 1

C: Large secondary pneumothorax requires chest drain

Answer 2

E- Initial management for someone who is overweight (BMI 25-29.9) is to provide detailed advice on diet, physical activity, and behavioural changes. Referral to a dietician or consideration of ather interventions might be appropriate if initial advice does not result in weight loss or if there are other health issues involved.

Answer 3

E: Adult polycystic kidney disease is an autosomal dominant condition.

Answer 4

D: This syndrome is characterized by the repeated, effortless regurgitation of recently ingested food. it is not preceded by retching, which differentiates it from conditions like bulimia nervosa where vomiting is induced, The food can be re-chewed, re swallowed, or spit out. Compensatory behaviours are only seen in anorexia and bulimia.

Answer 5

The description of the patient’s symptoms and the findings from the microscopy point towards a specific causative organism. Key Points: 1. Penile Discharge: Described as green and sticky. 2. Pain: In the penis and groin. 3. Reddening of the Penile Opening: Indicative of inflammation or infection. 4. Microscopy Findings: Presence of Gram-negative diplococci. Interpretation: • Gram-negative diplococci: This is a characteristic finding for Neisseria gonorrhoeae. Diagnosis: • Neisseria gonorrhoeae is the most likely causative organism given the presentation and microscopy findings. Correct Answer: D. Neisseria gonorrhoeae Explanation: • Trichomoniasis vaginalis: Typically causes frothy, yellow-green discharge, but is a protozoan and not a Gram-negative diplococci. • Chlamydia trachomatis: Often causes clear or white discharge and is an intracellular bacterium, not seen as Gram-negative diplococci. • Bacterial vaginosis: Primarily affects women and is characterized by a fishy odor and clue cells, not Gram-negative diplococci. • Mycoplasma genitalium: Causes non-gonococcal urethritis, typically clear discharge, and does not appear as Gram-negative diplococci on microscopy. Therefore, Neisseria gonorrhoeae is the most consistent with the clinical and microscopic findings in this case.

Answer 6

Wide local excision + postoperative radiotherapy Although mastectomy and mastectomy + postoperative radiotherapy are accepted treatment options for DCIS, wide local excision + postoperative radiotherapy is now frequently offered to women with tumours less than 40 mm in diameter of not an aggressive grade. Wide local excision attempts to conserve the unaffected breast tissue, thus avoiding the need for complete mastectomy, which carries greater psychological trauma to the patient. Mastectomy + postoperative radiotherapy is offered when DCIS is found in multiple areas of the breast, the tumour grade is aggressive, the size of the tumour is greater than 40 mm and if the ostrogen receptor status is negative. Ductal carcinoma in situ implies that the tumour is still confined to the basement membrane and has not broken through the latter. Thus axillary lymph nodes are at a greater chance of being affected once the tumour has broken through the basement membrane. With some exceptions, axillary staging and clearance is performed when multiple foci of extensive and aggressive DCIS are found.

Answer 7

Wide local excision and sentinel node biopsy The patient has a unifocal 2.5 cm malignant tumour in the right breast. The most appropriate management would be to perform a wide local excision of the breast tumour and it is essential to establish whether axillary disease is present or not. To assess disease positivity/negativity in the axilla, sentinel node biopsy should be performed. If the axillary sentinel lymph node is involved with metastatic tumour deposits originating from the primary breast tumour (e.g. macrometastases; tumour deposits. 2 mm), depending on the level of involvement of the axilla, the patient will undergo axillary clearance. This involves removing level 1-3 axillary lymph nodes to remove residual malignancy. It is not common practice for a patient diagnosed with breast cancer to undergo axillary clearance if the axilla has not been assessed. In some cases, an axillary lymph node FNA cytology assessment may be performed if there is palpable axillary disease. If the result confirms malignant disease, then the patient will undergo axillary clearance. Otherwise, sentinel node biopsy is usually performed to plan, whether the patient requires axillary clearance. The main indications for mastectomy are patients who have large tumours (>5 cm) that are unresponsive to chemotherapy, multifocal breast tumours, diffuse DCIS, and a large tumour relative to the patient's breast tissue

Answer 8

Breast carcinoma The most likely diagnosis here is breast carcinoma. The patient is in her sixth decade with a nulliparous history. Furthermore, blood-stained nipple discharge coupled with the non-tender breast lump place her at high risk of breast cancer. Milky to dirty-green nipple discharge is usually seen with mammary duct ectasia (common in postmenopausal women) and often, but not always, occurs bilaterally. Acute and periductal mastitis are unlikely here due to the absence of mastalgia. Although duct papillomas are relatively common causes of bloodstained discharge, they do not classically present with a breast lump and other symptoms are rarely present. Owing to the similar presentation of breast carcinoma, it is difficult to distinguish it from a duct papilloma by clinical examination alone.

Answer 9

Given the clinical presentation of a 58-year-old postmenopausal woman with a suspicious breast lump, the most appropriate course of action is to perform a biopsy to obtain a tissue diagnosis. The characteristics described (non-tender, irregular, firm lump with calcification on mammography and a solid mass on ultrasound) are concerning for malignancy. Most appropriate course of action: B. Core biopsy Explanation: • Repeat mammography and ultrasound scans in 6 months (A): Delaying further investigation in a postmenopausal woman with a suspicious breast lump is not appropriate. Prompt evaluation is necessary to rule out malignancy. • Core biopsy (B): A core biopsy provides a tissue sample for histopathological examination, which is crucial for diagnosing the nature of the lump, especially given the concerning features. • Fine needle aspiration (FNA) to ensure that the lump is not really fluid filled (C): FNA can help distinguish between cystic and solid masses, but it does not provide as much tissue as a core biopsy. In this case, core biopsy is preferred for a more definitive diagnosis. • Repeat mammography and ultrasound scans in 3 months (D): Similar to option A, this would delay necessary diagnosis and treatment. Immediate biopsy is more appropriate. • Reassure and discharge (E): Given the suspicious features of the lump, reassurance and discharge without further investigation is not appropriate. Conclusion: A core biopsy is the most appropriate next step to definitively diagnose the nature of the breast lump and guide further management.

Answer 10

Considering the patient’s age and the need for a thorough evaluation to rule out malignancy, the combination of imaging techniques is indeed crucial. In women over 40, breast lumps should be thoroughly evaluated to exclude breast cancer, even if the lump appears cystic. Most appropriate next course of action: E. Mammography and ultrasound Explanation: • Mammography and core biopsy (A): Core biopsy is invasive and typically follows imaging if needed. • Core biopsy (B): Not the initial step without prior imaging. • Fine needle aspiration (C): While FNA can confirm a cyst and provide symptom relief, it does not provide the comprehensive assessment needed to exclude malignancy. • Computed tomography scan (D): Not typically used for initial evaluation of breast lumps. • Mammography and ultrasound (E): This combination is the best initial approach, especially in women over 40, as it provides detailed information about the nature of the lump. Mammography can identify suspicious calcifications, and ultrasound can differentiate between solid and cystic lesions. Conclusion: For a 48-year-old perimenopausal woman with a breast lump, mammography and ultrasound is the most appropriate initial course of action. This approach ensures a comprehensive assessment to rule out malignancy while providing detailed information about the lump’s nature.

Answer 11

Alfa-blockade, followed by B-blockade followed by surgical resection Definitive treatment of a phaeochromocytoma is surgical resection, but before this is performed, pharmacological therapy is required to antagonize the effects of serum circulating catecholamines. a blockade with phenoxybenzamine is usually commenced 7-10 days before surgery, which allows blood volume expansion. Once this is achieved, ß blockade therapy is started. ß blockade cannot be initiated too early as unopposed a receptor stimulation may precipitate a hypertensive crisis. Once the patient has been established on adequate a and ß blockade, surgical resection of the tumour is carried out.

Answer 12

Fat necrosis The most likely answer here is fat necrosis. Although the irregularity and hardness of the breast lump with overlying skin tethering suggests breast carcinoma, the history of recent trauma coupled with overlying breast lump tenderness and bruising indicates fat necrosis rather than breast cyst, fibroadenosis and breast abscess. Breast cyst, fibroadenosis and breast abscess are all unlikely here because of the history.

Answer 13

Annual follow-up Once a breast cyst is diagnosed and imaging features are benign, there is usually a follow-up with the patient in 1 year. Wide local excision, follow-up appointment in 3 months, reassure and discharge and core biopsy are incorrect. Benign breast cysts usually produce a strawcoloured aspirate. Once drained, fluid-filled benign cysts usually collapse and the lump disappears. If the aspirate is blood stained or the lump fails to resolve, reevaluation with triple assessment is done within a few weeks.

Answer 14

Phyllodes tumour The most likely answer here is a malignant phyllodes tumour which accounts for 0.5% of all breast tumours. The recent increase in size of the right breast coupled with the discovery of a non-tender, mobile lump, giving the right breast a 'tear drop' appearance, is suggestive of a malignant phyllodes tumour. Phyllodes tumours have many of the clinical and histological features of fibroadenomas (which are common in women in their early to late twenties). Inflammatory breast carcinoma, as its name suggests, is associated with pain (unlike other breast cancers), breast erythema, peau d'orange (the skin overlying the breast resembles that of red-coloured orange peel) and skin ridging with or without a palpable mass. Paget's disease of the nipple presents as a unilateral, non-itchy, irregular eczematoid eruption of the nipple. It can be easily confused with eczema of the nipple, which usually occurs bilaterally, with pruritus, and can be nipple sparing. Breast abscess is unlikely here, and for more information, please refer to the answer to Question 2.

Answer 15

Paget's disease of the nipple The most likely answer here is Paget's disease of the nipple. The nonitchy, eczematoid changes in the overlying skin of the right nipple and accompanying ymphadenopathy suggests underlying breast malignancy rather than eczema. Paget's disease of the nipple is almost always associated with an underlying intraductal or invasive carcinoma. Early BCC lesions consist of raised pearly pink papules with fine overlying areas of telangiectasia. Late BCC lesions gradually ulcerate and are often referred to as 'rodent ulcers'. A malignant phyllodes tumour is unlikely here due to the absence of a lump and increase in size of the breast. Mastitis and breast abscess are also unlikely due to the presenting history and clinical findings (please refer to the answer to Question 2).

Answer 16

Mammary duct ectasia This presentation is typical of mammary duct ectasia, which is common in the decade around the menopause. The nipple discharge can vary, ranging from milky, brown to a dirty green colour. The nipple discharge can be bilateral and occasionally it is associated with cyclical mastalgia. The history of nipple retraction can cause confusion, leading the clinician to suspect breast carcinoma. However, the presence of the slit in the nipple, coupled with the colour of the nipple discharge and the perimenopausal age of the patient, make it more likely to be duct ectasia. Galactorrhoea is unlikely here as nipple discharge is usually bilateral and milky in appearance and this usually follows lactation. Duct papillomas usually present with blood-stained nipple discharge. Fibroadenoma does not usually present with nipple discharge and is common in women under the age of 35.

Answer 17

A Reassurance and discharge Traumatic fat necrosis of the breast, in most cases, does not warrant any treatment or follow-up and will usually resolve with time. In some cases, fat necrosis can leave a hard, irregular lump (with some overlying skin tethering) which can be mistaken for carcinoma. History of recent trauma to the breasts) makes carcinoma unlikely. Core biopsy can be performed to confirm the diagnosis. Therefore, follow-up appointment in 3 months, wide local excision, left mastectomy, and follow-up appointment in 6 months are all incorrect.

Answer 18

Excision of the lump After a diagnosis of fibroadenoma is made, small lesions (i.e. <2.5 cm) do not warrant excision. In most cases, patients are reassured and discharged from clinic, but due to the patient's significant family history of breast carcinoma, it is essential, and reassuring to her, for the lump to be excised. Therefore, excision of the lump is the most appropriate answer in this clinical vignette.

Answer 19

Reassure and discharge Mammary duct ectasia does not warrant treatment providing investigations are normal. Duct excision is only performed if the discharge is frequent and excessive. Antibiotic therapy is not usually a treatment option for this condition and will not provide a cure. Performing a mammography in 3 months is unlikely to be beneficial. Mastectomy of the right breast is not a recommended treatment modality.

Answer 20

Flucloxacillin Flucloxacillin is the antibiotic of choice for treating lactational acute mastitis. The crack in the left nipple allows invasion by skin commensal Staphylococcus aureus, the most common cause of breast infection. Flucloxacillin is a penicillinase-resistant antibiotic that is very effective against S. aureus infections. Breastfeeding or milk expression is still encouraged during treatment and has shown to quicken recovery. Amoxicillin (from the penicillin family), and ciprofloxacin (from the quinolone family) are ineffective against S. aureus. Erythromycin (from the macrolide family) is usually administered to patients who are allergic to penicillin formulas. It is not as effective as penicillinase-resistant antibiotics against S. aureus. Cephalexin (from the cephalosporin family), a moderate-spectrum antibiotic, can be used for S. aureus infections. However, cephalosporins are not considered a first line antibiotic therapy for the treatment of breast abscesses due to moderate-spectrum activity. In this case, the patient is not allergic to penicillin and thus flucloxacillin is the more appropriate choice of treatment.

Answer 21

Mastectomy + axillary clearance + postoperative radiotherapy to the axilla Lymphoedema of the arm usually occurs following the combination of surgical axillary clearance and postoperative radiotherapy to the axilla. This therapeutic combination is therefore not offered to patients as it is associated with an unacceptably high incidence of lymphoedema. Mastectomy + axillary clearance + postoperative radiotherapy to the chest wall, mastectomy + axillary clearance + systemic chemotherapy, mastectomy + axillary clearance and mastectomy + postoperative radiotherapy are incorrect options where the incidence of lymphoedema is relatively lower compared with mastectomy + axillary clearance + postoperative radiotherapy to the axilla.

Answer 22

Ultrasound guided fine needle aspiration Ultrasound assessment of this patient's breast lump confirms that it is a fluid-filled cyst with benign features. The next best course of action is therefore to offer the patient fine needle aspiration of the cyst. The extracted fluid is usually discarded. In some cases, if the Radiologist suspects that the cyst has indeterminate features, the aspirated cystic fluid may be sent off for cytological analysis (if but in some cases the fluid may be blood). Breast MRI is used in the assessment of multifocal/ bilateral disease and also in patients with cosmetic implants who are at a predisposed risk of breast cancer. Core biopsy, reassure and discharge and mammography are thus incorrect answers. For further clarification, please refer to the answer to Question 7.

Answer 23

Request an ultrasound of the left breast All breast lumps are investigated using 'triple assessment' which involves clinical examination, ultrasound breast scans for women younger than 35 (due to relatively denser breast tissue) or mammograms for women older than 35, followed by fine needle aspiration cytology and/or core biopsy for cytological and histological assessment, respectively. Women over the age of 35 tend to have less dense breast tissue, which increases the sensitivity and specificity of mammography. This patient is 25, which coupled with the discovery of two new lumps, indicates that the next line investigation, following clinical examination, would be an ultrasound of the left breast. Mammography would not be suitable as this patient is under the age of 35. Reassurance and discharge is clearly wrong as all breast lumps should undergo triple assessment before the patient is discharged. Fine needle aspiration and core biopsy, although they will be carried out, are not considered until radiological assessment has been performed.

Answer 24

Invasive breast carcinoma Triple assessment is adopted when investigating all breast lumps. Clinical history and examination is followed by imaging and then by cytological or histological analysis. On palpation of a breast lump, a grade of 1-5 is given based on its clinical characteristics. These are: • P1 - Normal breast tissue • P2 - Benign breast tissue • P3 - Suspicious but probably benign • P4 - Suspicious but probably malignant • P5 - Malignant The same 1-5 grading is used for imaging, but an 'M' is used for mammography and 'U' for ultrasound. Cytological grades are given as follows: • C1 - Normal cell architecture or inadequate sample • C2 - Benign cytology • C3 - Suspcious but probably benign • C4 - Suspicious but probably malignant • C5 - Malignant Histology grades for needle core biopsy are • B1 - Normal breast tissue or inadequate sample • B2 - Benign breast tissue • B3 - Suspious but probably benign • B4 - Suspicious but probably malignant • B5a - Carcinoma in-situ (e.g. ductal/lobular carcinoma in situ) • B5b - Invasive carcinoma (e.g. invasive ductal/lobular carcinoma) With regard to the question, the breast lesion was given a 'B5b' histology grade from the needle core biopsy sample. This histology result implies invasive malignancy

Answer 25

Desmopressin Symptoms of polyuria and polydipsia are common in many conditions. From the patient's history, she had suffered a head injury (the triggering factor for her symptoms) and after 2 weeks her symptoms started. The fact that she has no other symptoms makes it likely that this patient is suffering from diabetes insipidus, where vast amounts of dilute urine are secreted. Two forms exist: cranial diabetes insipidus (causes include head injury, cranial surgery, sarcoidosis), where there is a lack of ADH secretion from the posterior pituitary gland; and nephrogenic diabetes insipidus (causes include hypokalaemia, hypercalcaemia, drugs such as lithium and demecycline, genetic defects and heavy metal poisoning), where there is a lack of response of the kidneys to ADH. Diagnosis can be confirmed using the water deprivation test. This patient has cranial diabetes insipidus. From the list of options, the most likely answer is treatment with desmopressin (a synthetic analogue of ADH). Carbimazole is given to patients with hyperthyroidism. Spironolactone, in the context of endocrine medicine, is given to patients with Conn's syndrome. Thyroxine is given to hypothyroid patients and octreotide (a somatostatin analogue) can be used in patients with excessive growth hormone production (e.g. acromegaly) and patients with carcinoid syndrome.

Answer 26

Breast abscess Lactational breast abscesses are caused by the skin's commensal microorganisms, nearly always staphylococci, infiltrating cracks in the nipple during breastfeeding. Segmental breast inflammation occurs, leading to cellulitis which, if not treated promptly, results in breast tissue necrosis, pus build up and abscess formation within the breast segment. Continuous pain and sleepless nights coupled with the hard 3 cm painful lump suggest an abscess rather than acute mastitis. Fat necrosis is unlikely here with no history of previous minor local trauma. Periductal mastitis is possible, but classically occurs in non-lactating women of reproductive age and is associated with smoking. From the nature of the history and physical examination findings, it is unlikely to be a breast cyst.

Answer 27

Cyclical mastalgia The history of bilateral cyclical breast pain, which gradually intensifies before the start of the menses, and which is relieved once the menses start, is highly suggestive of cyclical mastalgia. The absolute cause of this condition is not yet clear, although it is thought to arise due to the sensitivity and responsiveness of breast tissue to hormones. Noncyclical mastalgia does not fit the history as it is not usually associated with the menstrual cycle. Tietze's syndrome is characterized by tenderness usually over the second, third or fourth costochondral junctions because of chondritis of the costal cartilages. Acute bacterial mastitis is possible, but usually does not present bilaterally and is not associated with the menstrual cycle. The affected breast is usually erythematous, swollen and extremely tender. Traumatic fat necrosis is clearly wrong as there is no history of recent trauma to the breasts.

Answer 28

Breast cyst Breast cysts usually occur in women over the age of 40 years through to the menopause. The aetiology in unclear, but it is thought that they occur due to hormonal imbalances around the menopause. Not all breast cysts manifest as pre-menstrual tenderness. The lump is mobile and fluctuant, suggesting that it is a fluid-filled cyst. Fibroadenomas classically present in females below the age of 35 and are infrequent after the age of 35-40. Fibroadenosis presents at a similar age, however the lump is fluctuant, making it more likely to be a cyst. Fat necrosis is unlikely here in the absence of previous minor local trauma (which is not stated in the history). Periductal mastitis is commonly seen in non-lactating women in their thirties (with a history of smoking) with pain usually developing in the areolar area.

Answer 29

Mastectomy + axillary clearance + systemic chemotherapy + radiotherapy and Tamoxifen The treatment options for male breast cancer are similar to those for female breast cancer. The most common form of breast cancer in males is invasive ductal carcinoma, which is also the most common type in women. There are four clinical stages of ductal carcinoma and determining the clinical stage allows for the selection of initial treatment. Patients who have stage 1 or 2 (early breast cancer) are more suitable for surgery whereas surgery should be avoided in patients who have stage 3 and 4 breast cancer, that is locally advanced cancer or metastatic spread at presentation, respectively, and they should be treated with chemotherapy. In this case, the patient has stage 2 breast cancer, implying that he is suitable for surgery. In addition, this tumour is ostrogen receptor positive; 90% of male breast cancers are oestrogen receptor positive. Mastectomy + axillary clearance, followed by systemic chemotherapy, radiotherapy and Tamoxifen, is the most suitable answer out of the five options. Chest wall radiotherapy coupled with systemic chemotherapy carries a better prognosis for the patient. Mastectomy alone would ensure tumour removal, but would not ensure the clearance of micrometastases, and the risk of recurrence/metastases would be higher without chemo/radiotherapy. Wide local excision would be difficult due to the invasive nature of the tumour and ensuring tumour clear margins of tissue. Mastectomy + radiotherapy is possible, but the addition of chemotherapy and hormonal therapy with Tamoxifen carries a better prognosis because of the higher Likelihood of removal of micrometastases. Patients who have stage 4 breast cancer (metastases at presentation) are usually offered palliative care

Answer 30

Fibroadenoma Fibroadenomas classically present in females below the age of 35 and are infrequent after the age of 35-40. They are described as painless, rubbery to firm, non-fluctuant, discrete mobile breast lumps commonly referred to as 'breast mice'. Breast cysts occur more frequently after the age of 35 and may present with breast pain. They can be fluctuant if fluid filled and characteristically are tense, discrete, mobile lumps. Carcinoma of the breast is rare under the age of 35, and usually presents as a solitary, painless, ill-defined lump of varying size which may show signs of skin tethering. Lipomas, although very common, are usually soft, fluctuant, irregularly defined lumps. Sebaceous cysts are typically round, soft lumps attached to the skin and have a central punctum.

Answer 31

C-Deltoid will atrophy as a result of severe damage to the axillary nerve, which may occur following dislocation of the shoulder. The axillary nerve also innervates teres minor and skin over the lateral side of the proximal part of the arm. Sensory loss in this area suggests nerve damage. The axillary nerve (C5, C6) winds around the surgical neck of the humerus, accompanying the posterior circumflex humeral vessels. It is prone to damage in humeral neck fractures or dislocation of the shoulder. The radial nerve runs in the spiral groove, where it is accompanied by the profunda brachii artery. Mid-shaft humeral fractures may damage the radial nerve as it runs in the spiral groove. The branches to the lateral and long head of triceps arise before the nerve enters the groove, and thus only the medial head is affected. The characteristic sign of this injury is wrist drop due to paralysis of the posterior compartment of the forearm. The ulnar nerve passes posterior to the medial epicondyle where it is superficial, easily palpable and prone to injury.

Answer 32

Smoking. Factors predisposing to gallstone formation include sepsis within the biliary tree, anatomical variants which predispose to stasis and changes in the composition of bile which make it lithogenic. Amirand's triangle is a diagrammatic representation of how changes in bile composition can predispose to stone formation. Put simply, if the percentage composition of cholesterol increases, or the percentage composition of bile salts or phospholipids (lecithin) decreases, then the bile is more likely to form gallstones. When taking a focused history and examination, candidates should aim to elicit/exclude the following risk factors for gallstone formation: • Race (higher incidence in black and Asian populations) • High-fat diet/history of hypercholesterolaemia • Obesity • High ostrogen states (CCP, pregnancy, PCOS; hence the slight female predominance) • Haemolytic states The loss of the terminal ileum following surgery or as a consequence of Crohn's disease also predisposes to gallstone formation as the terminal ileum is the site of re-absorption of bile salts. Smoking is not known to directly influence the risk of gallstone formation.

Answer 33

Hamartomas are fundamentally comprised of disordered replications of normal tissue cells. The underlying mechanisms of anomalous replications are not fully recognized. The particular property is a clearly demarcated mass mainly containing fat and cartilage, but other tissue cells may also be present depending on the anatomic location. The size of most hamartomas is between 1 to 3 cm. References https://www.ncbi.nlm.nih.gov/books/NBK562298/

Answer 34

The patient’s symptoms of dizziness, sweating, palpitations, and collapsing episodes after meals, particularly large ones, suggest dumping syndrome, a common complication after gastric bypass surgery. This condition is typically caused by the rapid transit of hyperosmolar food from the stomach into the small intestine, leading to a rapid fluid shift and subsequent release of hormones. Key Points: • Symptoms: Dizziness, sweating, palpitations, collapsing episodes after meals. • Context: Post-gastric bypass surgery. Likely Mechanism: • Early Dumping Syndrome: Occurs 15-30 minutes after eating, caused by rapid gastric emptying. • Pathophysiology: Rapid entry of hyperosmolar contents into the small intestine leads to fluid shift, triggering autonomic responses and release of gastrointestinal hormones. • Release of Insulin: The rapid absorption of carbohydrates can lead to a quick spike in blood glucose followed by a compensatory release of insulin, which can cause hypoglycemia and associated symptoms like dizziness, sweating, and palpitations. Explanation: • C Release of insulin: The rapid transit of food into the small intestine and subsequent hyperglycemia results in a quick release of insulin, which then causes hypoglycemia and the described symptoms. Answer: C Release of insulin

Answer 35

A chest drain can cause an intercostal artery bleed during insertion or movement, either by direct trauma or tissue injury to the artery. Improper technique or anatomical variations can increase this risk. Prompt recognition and management are crucial. References https://www.ncbi.nlm.nih.gov/pmc/articles/PMC861090 4/#:-:text=Complications%20such%20as%20intercost| al% 20artery,procedure%2C%20unlike%20in%20cathet| er%20removal.

Answer 36

The most common region in descending order: superficial inguinal pouch which lies anterior to the external oblique aponeurosis, perineum / anterior to root of penis, femoral triangle / upper thigh, contralateral scrotum. References https://radiopaedia.org/articles/ectopic-testis

Answer 37

The middle colic artery passes in the layers of the transverse mesocolon to the transverse colon and divides into right and left branches: Right branch supplies the right portion of the transverse colon and anastomoses at the hepatic flexure with the ascending branch of the right colic artery. Left branch supplies the left portion of the transverse colon and anastomoses at the splenic flexure with the left colic artery of the inferior mesenteric artery. References https://radiopaedia.org/articles/middle-colic-artery

Answer 38

The raindrop skull appearance of calvarial multiple myeloma is the presence of well defined lytic lesions (punched out lesions) of various sizes scattered throughout the skull. References https://radiopaedia.org/cases/multiple-myeloma-skull-

Answer 39

Pancreatitis can be associated with tetany and hypocalcemia. Ranson Criteria: Criteria and Prognosis At Admission • Age > 55 years • Leukocyte count > 16 x 103/mcL • Blood glucose > 200 mg/dL • Serum LDH > 350 IU/L • Serum AST > 250 IU/L At 48 hours • Decrease in hematocrit > 10% • Increase in BUN of > 8 mg/dL • Serum calcium less than 8 mg/dL • Pa02 < 60 mm Hg • Base deficit > 4 mEq/L • Estimated fluid sequestration > 6,000 mL Score < 3 = Mortality 0-3% • Score 2 3 = Mortality 11-15% • Score ≥ 6 = Mortality 40% References https://emedicine.medscape.com/article/241893- overview#:-:text=Pancreatitis%20can%20be%20assoc iated%20with,secretion%20may%20play%20a%20role

Answer 40

In the cubital fossa, the anatomical relationships of the structures are crucial for surgical exploration and management. The brachial artery has a specific relationship to the median nerve and other structures in this region. The correct answer is C lateral to the median nerve. Explanation: The anatomical arrangement of structures in the cubital fossa from medial to lateral is often remembered by the mnemonic “My Brother Throws Rad Parties,” which stands for: • Medial nerve • Brachial artery • Tendon of the biceps brachii • Radial nerve (superficial and deep branches) So, in detail: • The median nerve lies most medially. • The brachial artery lies just lateral to the median nerve. • The biceps tendon lies lateral to the brachial artery. • The radial nerve is the most lateral structure in the cubital fossa. Given these anatomical relationships: • A: Medial to the median nerve – Incorrect. The brachial artery is lateral to the median nerve. • B: Anterior to the median nerve – Incorrect. The brachial artery is not anterior to the median nerve. • C: Lateral to the median nerve – Correct. This matches the anatomical relationship in the cubital fossa. • D: Superficial to the bicipital aponeurosis – Incorrect. The brachial artery is deep to the bicipital aponeurosis. • E: Lateral to the biceps tendon – Incorrect. The brachial artery is medial to the biceps tendon.

Answer 41

Second left intercostal space is where pulmonary value is located. EXPLANATION OF THE AUSCULTATION AREAS A(Aortic area): The second intercostal space to the right of the sternum. B(Pulmonic area: The second intercostal space to the left of the sternum. C(Tricuspid area: The fourth intercostal space to the left of the sternum. D(Mitral area) : The fifth intercostal space in the left midclavicular line.

Answer 42

A subareolar abscess is a painful collection of pus that forms beneath the areola, usually as a result of an infected milk duct. The presentation often includes localized pain, redness, swelling, and warmth in the affected breast area. Squamous metaplasia of lactiferous ducts can occur in cases of subareolar abscess. Squamous metaplasia is a process where the normal glandular epithelium lining the lactiferous ducts undergoes transformation into squamous epithelium. This transformation is often associated with chronic inflammation and infection in the breast, such as in the case of a subareolar abscess. References https://www.ncbi.nlm.nih.gov/pmc/articles/PMC773308 8/#:-:text=Squamous%20metaplasia%20of%20lactifer ous%20ducts%20(SMOLD)%20was%20previously%20 known%20as,changes%20to%20the%20breast%20duc ts.

Answer 43

The hematological picture presented, which includes an elevated hemoglobin level (polycythemia), is most likely associated with renal cell carcinoma. Correct Answer: C renal cell carcinoma Explanation: Renal cell carcinoma (RCC) is known for its potential to produce erythropoietin (EPO), a hormone that stimulates red blood cell production. This can lead to secondary polycythemia, which is characterized by elevated hemoglobin levels as seen in this patient. The other blood parameters (white cell count and platelet count) are within normal ranges, which is consistent with the isolated effect on red blood cell production typically seen in RCC-induced polycythemia. • A bronchial carcinoma: While bronchial carcinoma can present with various paraneoplastic syndromes, polycythemia is not commonly associated with it. • B transitional cell carcinoma of the kidney: This type of carcinoma does not typically produce EPO or lead to polycythemia. • D prostatic carcinoma: This carcinoma does not commonly cause polycythemia. • E pancreatic carcinoma: Pancreatic carcinoma can be associated with various paraneoplastic syndromes, but polycythemia is not typically one of them. Given the patient’s elevated hemoglobin level and the known association of RCC with EPO production, renal cell carcinoma is the most likely diagnosis.

Answer 44

Starvation ketoacidosis (SKA) represents one of three metabolic acidoses caused by the accumulation of ketone bodies within the bloodstream. While easily treated, it is a diagnosis that can be easily missed in patients with an unexplained metabolic acidosis. The clinical scenario suggests that the patient is in acute kidney injury (AKI), likely due to dehydration and reduced intake following surgery, leading to elevated urea and creatinine levels. The patient has also not eaten for four days, which can contribute to metabolic derangements. Given the elevated creatinine, the patient likely has reduced renal function, which often leads to a metabolic acidosis, characterized by a low pH, low bicarbonate, and a compensatory low pCO2 due to hyperventilation. Correct Answer: B рН 7.23, pO2 13.6kPa, pCO2 3.8kPa, Bicarbonate 13.5mmol/L Explanation: • pH 7.23: Indicates acidosis (pH < 7.35). • pO2 13.6kPa: Oxygen levels can vary but are within a reasonable range. • pCO2 3.8kPa: Low pCO2 indicates respiratory compensation for metabolic acidosis (hyperventilation). • Bicarbonate 13.5mmol/L: Low bicarbonate is consistent with metabolic acidosis. Other options are less likely because they do not fit the expected acid-base disorder in the context of acute kidney injury and metabolic stress from not eating: • A: Normal pH with high bicarbonate, suggesting metabolic alkalosis, which does not fit the clinical picture. • C: Normal to slightly elevated pH with low bicarbonate and low pCO2, suggesting respiratory alkalosis, which does not fit the clinical picture. • D: Elevated pH indicating alkalosis, which does not fit with the expected acidosis. • E: Low pH and high bicarbonate with high pCO2, suggesting a mixed disorder but not fitting with the typical response in acute kidney injury and fasting.

Answer 45

The closure of the tricuspid valve occurs at the onset of the isovolumetric contraction phase of the cardiac cycle. References https://www.sciencedirect.com/topics/agricultural-and- biological-sciences/isovolumetric-contraction

Answer 46

Initially, during a Valsalva, intrathoracic (intrapleural) pressure becomes very positive because of compression of the thoracic organs by the contracting rib cage. Manoeuvre: • Valsalva manoeuvre refers to a forced expiration against a closed glottis. • This causes marked decrease in the thoracic volume causing deflation of lungs. Under such circumstances the intrapleural pressure can become positive by 60-70 mmHg. • The common everyday activities in which Valsalva manoeuvre effect straining defecation, phase coughing, during during parturition. In some of the pathological conditions such as Pneumothorax Hydrothorax Hemothorde Dothorax Tends to be more positive. -In Valsalva Maneuver pleural pressure becomes more positive. -In reverse Valsalva/Mueller's Maneuver pleural pressure becomes less positive. References https://cvphysiology.com/hemodynamics/h014

Answer 47

The correct answer to the question is: E. Lacunar ligament Explanation: In the anatomy of the femoral region, the femoral canal, through which a femoral hernia protrudes, is bounded by the lacunar ligament medially. The lacunar ligament is a crescent-shaped fibrous band that forms the medial boundary of the femoral ring. It is located medial to the femoral vein and, therefore, medial to the neck of a femoral hernia. This anatomical relationship is crucial for understanding the path of femoral hernias and their surgical treatment. The femoral canal is an anatomical structure located in the femoral region. It is a small compartment within the femoral sheath, and its boundaries are important to understand, especially in the context of femoral hernias. The boundaries of the femoral canal are as follows: 1. Anterior Boundary: Inguinal ligament. 2. Posterior Boundary: Pectineal ligament (also known as the ligament of Cooper), which lies over the pectineus muscle and fascia. 3. Medial Boundary: Lacunar ligament. 4. Lateral Boundary: Femoral vein. These boundaries form a conical space that allows for the passage of lymphatics and a small amount of fat. The femoral ring, the entrance to the femoral canal, is a potential weak spot where femoral hernias can occur.

Answer 48

The symptoms described — abdominal pain, multiple episodes of bloody diarrhea, joint pain (knees and elbows), and visual problems — are highly suggestive of an inflammatory bowel disease (IBD). The most likely diagnosis among the options provided is: B. Ulcerative colitis Explanation: • Ulcerative colitis is a chronic inflammatory bowel disease that typically presents with bloody diarrhea, abdominal pain, and can also have extra-intestinal manifestations such as arthritis (pain in joints) and uveitis or episcleritis (visual problems). • Intestinal tuberculosis usually presents with chronic abdominal pain, weight loss, and sometimes diarrhea, but bloody diarrhea is less typical and extra-intestinal symptoms such as joint pain and visual problems are less common. • Infective colitis can cause bloody diarrhea, but the chronic joint and visual symptoms are less characteristic. • Collagenous colitis typically presents with chronic watery diarrhea and does not usually cause bloody diarrhea or extra-intestinal symptoms like joint pain and visual issues. • Diverticulitis typically presents with localized abdominal pain, often in the left lower quadrant, and does not usually cause bloody diarrhea or extra-intestinal symptoms. Therefore, the combination of gastrointestinal and extra-intestinal symptoms in this patient most strongly suggests ulcerative colitis.

Answer 49

The electrocardiogram (ECG) change that would support a diagnosis of pulmonary embolism is: B. T wave inversion in V1-V3 Explanation: • Pulmonary embolism often causes right ventricular strain, which can be reflected on an ECG. One of the common ECG changes seen in pulmonary embolism is T wave inversion in the right precordial leads (V1-V3). • Dominant R wave in V6 is not typically associated with pulmonary embolism. • Left axis deviation is more commonly associated with left-sided heart conditions and is not a typical finding in pulmonary embolism. • ST elevation in V1-V3 could indicate an acute myocardial infarction (MI) but is not typical for pulmonary embolism. • Left bundle branch block (LBBB) indicates a delay in electrical conduction in the left bundle branch and is not specific to pulmonary embolism. Therefore, T wave inversion in V1-V3 is the most relevant ECG finding that would support the suspicion of a pulmonary embolism.

Answer 50

The muscle most likely damaged in this scenario is: E. Supraspinatus Explanation: • The supraspinatus muscle is part of the rotator cuff and is primarily responsible for initiating the abduction of the arm. If the patient is unable to actively initiate abduction, it suggests damage to this muscle. • Teres major is involved in the internal rotation and adduction of the arm, not abduction. • The clavicular head of pectoralis major assists in flexion, adduction, and internal rotation of the arm. • Infraspinatus is another rotator cuff muscle, but it is primarily responsible for external rotation of the arm, not abduction. • The trapezius muscle is involved in moving, rotating, and stabilizing the scapula, and it assists in shoulder elevation but is not responsible for initiating abduction. Given the specific inability to initiate abduction, damage to the supraspinatus muscle is the most likely cause.

Answer 51

The correct statement is: B. Clavicle derives its cutaneous innervation from C4. Explanation: • A. Posterior surface of the forearm derives its cutaneous innervation from T1: This is incorrect. The posterior surface of the forearm is typically innervated by C6 and C7 dermatomes. • B. Clavicle derives its cutaneous innervation from C4: This is correct. The skin over the clavicle is typically innervated by the C4 dermatome. • C. Thumb derives its cutaneous innervation from T1: This is incorrect. The thumb is innervated by the C6 dermatome. • D. Little finger derives its cutaneous innervation from C7: This is incorrect. The little finger is innervated by the C8 dermatome. • E. Lateral aspect of the upper limb derives its cutaneous innervation from C8 and T1: This is incorrect. The lateral aspect of the upper limb is primarily innervated by C5 and C6 dermatomes. Therefore, the correct answer is that the skin over the clavicle derives its cutaneous innervation from C4.

Answer 52

The most appropriate ending for the sentence is: C. Gives no muscular branches in the arm. Explanation: • A. Supplies all of flexor digitorum profundus: This is incorrect. The median nerve supplies only the lateral half (index and middle fingers) of the flexor digitorum profundus, while the ulnar nerve supplies the medial half (ring and little fingers). • B. Arises from both the posterior and medial cords of the brachial plexus: This is incorrect. The median nerve arises from both the lateral and medial cords of the brachial plexus. • C. Gives no muscular branches in the arm: This is correct. The median nerve does not supply any muscles in the arm; its motor branches are all in the forearm and hand. • D. Enters the forearm by passing between the two heads of flexor carpi ulnaris: This is incorrect. The median nerve enters the forearm by passing between the two heads of the pronator teres, not the flexor carpi ulnaris. • E. Passes from the medial to the lateral side of the brachial artery in the arm: This is incorrect. The median nerve passes from the lateral to the medial side of the brachial artery as it descends in the arm. Thus, the most accurate statement is that the median nerve gives no muscular branches in the arm.

Answer 53

The accurate statement about the axillary artery is: A. The axillary vein lies medial throughout its course. Explanation: • A. The axillary vein lies medial throughout its course: This is correct. The axillary vein lies medial to the axillary artery throughout its course in the axilla. • B. It is divided into three parts by pectoralis major: This is incorrect. The axillary artery is divided into three parts by the pectoralis minor muscle, not pectoralis major. • C. It becomes the brachial artery at the inferior border of teres minor: This is incorrect. The axillary artery becomes the brachial artery at the inferior border of the teres major muscle, not teres minor. • D. The cords of the brachial plexus are named according to their positions relative to the first part: This is incorrect. The cords of the brachial plexus are named according to their positions relative to the second part of the axillary artery. • E. It gives the suprascapular artery as one of its branches: This is incorrect. The suprascapular artery is a branch of the thyrocervical trunk, which is a branch of the subclavian artery, not the axillary artery. Therefore, the most accurate statement is that the axillary vein lies medial throughout its course.

Answer 54

To determine which statement regarding the radius and ulna is correct, we will analyze each option step by step. A. Both articulate with the humerus at the elbow joint. The radius and ulna are both forearm bones that do indeed articulate with the humerus at the elbow joint. The ulna primarily forms the hinge joint with the humerus, while the radius also plays a role in this articulation, especially in terms of rotation during pronation and supination of the forearm. Therefore, this statement is correct. B. Both have a styloid process at the proximal end. The radius has a styloid process at its distal end, while the ulna has a styloid process at its distal end as well but not at its proximal end. This means that this statement is incorrect because only one of them has a styloid process at the proximal end. C. Fracture is most commonly of the Smith’s type. A Smith’s fracture refers to a fracture of the distal radius with volar angulation (the palm side). While fractures of the radius are common, particularly in older adults due to falls, they are more often Colles’ fractures rather than Smith’s fractures. Therefore, this statement is incorrect. D. Direct injury usually produces transverse fractures of both bones in the distal third. Direct injuries can lead to various types of fractures depending on the mechanism involved; however, transverse fractures specifically affecting both bones in their distal third are not typically described as common outcomes from direct trauma. This statement is therefore considered incorrect. E. Both articulate with the carpal bones at the wrist joint. The radius articulates directly with several carpal bones (specifically scaphoid and lunate) at the wrist joint, while the ulna does not have a direct articulation with any carpal bones; instead, it is separated from them by an articular disc (the triangular fibrocartilage complex). Thus, this statement is incorrect. After analyzing all statements: The only correct statement regarding both radius and ulna is: A Both articulate with the humerus at the elbow joint.

Answer 55

Let’s analyze each option to determine which best describes the forearm: A. Pronator quadratus lies deep to the long flexor tendons just proximal to the wrist. • True. Pronator quadratus is located deep to the flexor digitorum superficialis and profundus tendons near the wrist. B. The median nerve is related anteriorly to flexor digitorum superficialis. • False. The median nerve runs between the flexor digitorum superficialis and the flexor digitorum profundus, not anteriorly to flexor digitorum superficialis. C. Flexor digitorum profundus is partially supplied by the posterior interosseous nerve. • False. Flexor digitorum profundus is innervated by the median nerve (anterior interosseous branch) for the lateral part and the ulnar nerve for the medial part. D. The ulnar nerve lies superficial to flexor carpi ulnaris. • False. The ulnar nerve actually lies deep to flexor carpi ulnaris. E. The radial nerve carries motor fibres in the anterior compartment of the forearm. • False. The radial nerve supplies the muscles in the posterior compartment of the forearm. Based on the analysis, the correct answer is: A. Pronator quadratus lies deep to the long flexor tendons just proximal to the wrist. Explanation: Pronator quadratus is a deep muscle in the forearm located just proximal to the wrist, lying beneath the tendons of the flexor digitorum profundus and superficialis, aligning with the description in the correct option.

Answer 56

C The biceps jerk principally tests the C5 reflex arc, with a contribution from C6. The supinator jerk corresponds primarily to the C6 reflex arc, with a contribution from C5. The triceps jerk is principally mediated by C7, with a contribution from C8. This reflex may be of occasional use, and is elicited by placing the examiner's index finger across the tip of the shoulder on the deltoid muscle belly, and tapping the finger. It solely tests the reflex arc of spinal cord segment C5. The pectoral reflex is elicited by placing the examiner's index and middle fingers on the lateral border of pectoralis major and tapping them with a tendon hammer. It tests the reflex arc of C7.

Answer 57

E Flexor pollicis longus is one of the deep group of flexor muscles. Its principle origin is from the radius. It is characteristically unipennate, which aids its identification during forearm surgery. The median nerve enters the forearm between the two heads of pronator teres. The ulnar nerve enters the forearm by passing between the two heads of flexor carpi ulnaris. Palmaris longus is a vestigial structure, absent in 13% of arms. Flexor digitorum profundus is one of the deep group of flexor muscles and principally takes origin from the ulna. The superficial group of flexor muscles are pronator teres, flexor carpi radialis, palmaris longus, flexor digitorum superficialis and flexor carpi ulnaris. The median nerve innervates all these muscles except flexor carpi ulnaris, which is innervated by the ulnar nerve.

Answer 58

D The 8 carpal bones, arranged in 2 rows of 4, form the carpus. The carpus is convex posteriorly and concave anteriorly from side to side. This shape is maintained by the shape of the bones and by the pull of the flexor retinaculum. The most commonly fractured bone is the scaphoid. This occurs most commonly as a result of a fall onto the palm, with the hand extended and abducted. The principal blood supply of the scaphoid enters from its distal end. A fracture may therefore interrupt the blood supply to the proximal fragment, leading to avascular necrosis and consequent degenerative change. The scaphoid is one of the four proximal bones of the wrist and articulates with the radius proximally. The trapezium is the carpal bone which articulates with the 1st metacarpal. The deep branch of the ulnar nerve is closely related to the hook of the hamate, and is threatened by a hamate fracture. Decreased grip strength usually ensues. The pisiform bone is a small, pea-shaped, sesamoid bone in the tendon of the flexor carpi ulnaris. Its ossification centre usually does not appear until the age of 9-12 years. It is the last carpal bone to begin ossification.

Answer 59

A The flexor digitorum superficialis tendon splits to enclose the profundus tendon as it inserts into the middle phalanx of the finger. The profundus tendon continues to insert into the base of the distal phalanx. The fibrous flexor sheaths run from the metacarpal heads to the distal phalanges. They are occupied by the tendons of flexors digitorum superficialis and profundus in the fingers and the tendon of flexor pollicis longus in the thumb. The annular pullies overlie the phalanges and consist of strong transverse sheath fibres. In the index, middle and ring fingers there is a gap between the common flexor sheath in the carpal tunnel and the synovial sheaths of the fingers. The sheaths of the thumb and little finger are continuous with those of the carpal tunnel. The cruciform pullies overlie the interphalangeal joints and consist of loose fibres which are arranged obliquely.

Answer 60

Milroy's disease is congenital. Meiges' develops after birth. Lymphoedema - Due to impaired lymphatic drainage in the presence of normal capillary function. Lymphoedema causes the accumulation of protein rich fluid, subdermal fibrosis and dermal thickening. Characteristically fluid is confined to the epifascial space (skin and subcutaneous tissues); muscle compartments are free of oedema. It involves the foot, unlike other forms of oedema. There may be a 'buffalo hump' on the dorsum of the foot and the skin cannot be pinched due to subcutaneous fibrosis. Causes of lymphoedema Primary Congenital < 1 year: sporadic, Milroy's disease Onset 1-35 years: sporadic, Meige's disease > 35 years: Tarda Secondary Bacterial/fungal/parasitic infection (filariasis) Lymphatic malignancy Radiotherapy to lymph nodes Surgical resection of lymph nodes DVT Thrombophlebitis Indications for surgery Marked disability or deformity from limb swelling Lymphoedema caused by proximal lymphatic obstruction with patent distal lymphatics suitable for a lymphatic drainage procedure Lymphocutaneous fistulae and megalymphatics Procedures Homans operation Reduction procedure with preservation of overlying skin (which must be in good condition). Skin flaps are raised and the underlying tissue excised. Limb circumference typically reduced by a third. Charles operation All skin and subcutaneous tissue around the calf are excised down to the deep fascia. Split skin grafts are placed over the site. May be performed if overlying skin is not in good condition. Larger reduction in size than with Homans procedure. Lymphovenous anastamosis Identifiable lymphatics are anastomosed to sub dermal venules. Usually indicated in 2% of patients with proximal lymphatic obstruction and normal distal lymphatics.

Answer 61

Carbohydrate loading is one of the enhanced recovery principles. Pre operative fluid management Fluid management has been described in the British Consensus guidelines on IV fluid therapy for Adult Surgical patients (GIFTASUP) and by NICE (CG174 December 2013 updated May 2017) The Recommendations include: Use Ringer's lactate or Hartmann's when a crystalloid is needed for resuscitation or replacement of fluids. Avoid 0.9% N. Saline (due to risk of hyperchloraemic acidosis) unless patient vomiting or has gastric drainage. Use 4%/0.18% dextrose saline or 5% dextrose in maintenance fluids. It should not be used in resuscitation or as replacement fluids. Adult maintenance fluid requirements are: Na 50-100 mmol/day and K 40-80 mmol/day in 1.5-2.5L fluid per day. Patients for elective surgery should NOT be nil by mouth for >2 hours (unless has disorder of gastric emptying). Patients for elective surgery should be given carbohydrate rich drinks 2-3h before. Ideally this should form part of a normal pre op plan to facilitate recovery. Avoid mechanical bowel preparation. If bowel prep is used, simultaneous administration of Hartmann's or Ringer's lactate should be considered. Excessive fluid losses from vomiting should be treated with a crystalloid with potassium replacement. 0.9% N. Saline should be given if there is hypochloraemia. Otherwise Hartmann's or Ringer lactate should be given for diarrhoea/ileostomy/ileus/obstruction. Hartmann's should also be given in sodium losses secondary to diuretics. High risk patients should receive fluids and inotropes. An attempt should be made to detect pre or operative hypovolaemia using flow based measurements. If this is not available, then clinical evaluation is needed i.e. JVP, pulse volume etc. In Blood loss or infection causing hypovolaemia should be treated with a balanced crystalloid or colloid (or until blood available in blood loss). A critically ill patient is unable to excrete Na or H20 leading to a 5% risk of interstitial oedema. Therefore 5% dextrose as well as colloid should be given. If patients need IV fluid resuscitation, use crystalloids that contain sodium in the range 130-154 mmol/l, with a bolus of 500 ml over less than 15 minutes (NICE Guidance CG 174).

Answer 62

At the 3rd month the foetus's spinal cord occupies the entire length of the vertebral canal. The vertebral column then grows longer exceeding the growth rate of the spinal cord. This results with the cord being at L3 at birth and L1-2 by adulthood. Spinal cord - Located in a canal within the vertebral column that affords it structural support. Rostrally it continues to the medulla oblongata of the brain and caudally it tapers at a level corresponding to the L1-2 interspace (in the adult), a central structure, the filum terminale anchors the cord to the first coccygeal vertebra. The spinal cord is characterised by cervico-lumbar enlargements and these, broadly speaking, are the sites which correspond to the brachial and lumbar plexuses respectively. There are some key points to note when considering the surgical anatomy of the spinal cord: * During foetal growth the spinal cord becomes shorter than the spinal canal, hence the adult site of cord termination at the L1-2 level. * Due to growth of the vertebral column the spine segmental levels may not always correspond to bony landmarks as they do in the cervical spine. * The spinal cord is incompletely divided into two symmetrical halves by a dorsal median sulcus and ventral median fissure. Grey matter surrounds a central canal that is continuous rostrally with the ventricular system of the CNS. * The grey matter is sub divided cytoarchitecturally into Rexeds laminae. * Afferent fibres entering through the dorsal roots usually terminate near their point of entry but may travel for varying distances in Lissauers tract. In this way they may establish synaptic connections over several levels * At the tip of the dorsal horn are afferents associated with nociceptive stimuli. The ventral horn contains neurones that innervate skeletal muscle. The key point to remember when revising CNS anatomy is to keep a clinical perspective in mind. So it is worth classifying the ways in which the spinal cord may become injured. These include: Trauma either direct or as a result of disc protrusion Neoplasia either by direct invasion (rare) or as a result of pathological vertebral fracture Inflammatory diseases such as Rheumatoid disease, or OA (formation of osteophytes compressing nerve roots etc. Vascular either as a result of stroke (rare in cord) or as complication of aortic dissection Infection historically diseases such as TB, epidural abscesses. The anatomy of the cord will, to an extent dictate the clinical presentation. Some points/ conditions to remember: Brown- Sequard syndrome-Hemisection of the cord producing ipsilateral loss of proprioception and upper motor neurone signs, plus contralateral loss of pain and temperature sensation. The explanation of this is that the fibres decussate at different levels. Lesions below L1 will tend to present with lower motor neurone signs

Answer 63

Coarctation of the aorta may occur due to the remnant of the ductus arteriosus acting as a fibrous constrictive band of the aorta. Weak arm pulses may be seen, radiofemoral delay is the classical physical finding. Collateral flow through the intercostal vessels may produce notching of the ribs, if the disease is long standing. Vascular disease Aortic dissection Chest pain (anterior chest pain- ascending aorta, back pain - descending aorta) Widening of aorta on chest x-ray Diagnosis made by CT scanning Treatment is either medical (Type B disease) or surgical (Type A disease) Cervical rib Supernumery fibrous band arising from seventh cervical vertebra Incidence of 1 in 500 May cause thoracic outlet syndrome Treatment involves surgical division of rib Subclavian steal syndrome Due to proximal stenotic lesion of the subclavian artery Results in retrograte flow through vertebral or internal thoracic arteries The result is that decrease in cerebral blood flow may occur and produce syncopal symptoms A duplex scan and/ or angiogram will delineate the lesion and allow treatment to be planned Takayasu's arteritis Large vessel granulomatous vasculitis Results in intimal narrowing Most commonly affects young asian females Patients present with features of mild systemic illness, followed by pulseless phase with symptoms of vascular insufficiency Treatment is with systemic steroids Patent ductus arteriosus Ductus arteriosus is a normal foetal vessel that closes spontaneously after birth Results in high pressure, oxygenated blood entering the pulmonary circuit Untreated patients develop symptoms of congestive cardiac failure Coarctation of the aorta Aortic stenosis at the site of the ductus arteriosus insertion More prevalent in boys or females with Turners syndrome Patients may present with symptoms of arterial insufficiency, such as syncope and claudication Blood pressure mismatch may be seen, as may mismatch of pulse pressure in the upper and lower limbs Treatment is either with angioplasty or surgical resection (the former is the most common)

Answer 64

Peroneus brevis passes posterior to the lateral malleolus. Peroneus tertius is closely related to extensor digitorum and like that muscle, its tendon passes anterior to the lateral malleolus Lateral malleolus Structures posterior to the lateral malleolus and superficial to superior peroneal retinaculum Sural nerve Short saphenous vein Structures posterior to the lateral malleolus and deep to superior peroneal retinaculum Peroneus longus tendon Peroneus brevis tendon The calcaneofibular ligament is attached at the lateral malleolus

Answer 65

Correct Answer: D. Sodium thiopentone Explanation: Positive inotropic drugs increase the strength of cardiac muscle contraction, which improves cardiac output. Here’s a brief explanation of each drug: • Dopamine: A catecholamine that increases heart contractility and cardiac output by stimulating beta-1 adrenergic receptors. • Glucagon: Increases heart contractility by stimulating adenylate cyclase and increasing cyclic AMP, independent of the adrenergic receptors. • Theophylline: A methylxanthine that can increase heart contractility through its action as a phosphodiesterase inhibitor, leading to increased cyclic AMP levels. • Sodium thiopentone (Thiopental): A barbiturate used for induction of anesthesia. It has a depressive effect on the central nervous system and does not have positive inotropic effects. In fact, it can cause myocardial depression and reduce cardiac output. • Dobutamine: A synthetic catecholamine that acts on beta-1 adrenergic receptors, increasing heart contractility and cardiac output. Therefore, Sodium thiopentone is the drug that is not positively inotropic. Inotropes are a class of drugs that increase the force or cardiac contractility. This may improve cardiac output. Increased blood pressure may have direct beneficial effects for the heart in that it improves myocardial perfusion pressure. Dopamine and dobutamine are both commonly used inotropes, they should be administered via a central line and in a monitored setting. Glucagon and theophylline are also positive inotropes (although not commonly used for this purpose). In contrast sodium thiopentone causes marked myocardial depression. Inotropes and cardiovascular receptors Inotropes are a class of drugs which work primarily by increasing cardiac output. They should be distinguished from vasoconstrictor drugs which are used specifically when the primary problem is peripheral vasodilatation. Catecholamine type agents are commonly used and work by increasing cAMP levels by adenylate cyclase stimulation. This in turn increases intracellular calcium ion mobilisation and thus the force of contraction. Adrenaline works as a beta adrenergic receptor agonist at lower doses and an alpha receptor agonist at higher doses. Dopamine causes dopamine receptor mediated renal and mesenteric vascular dilatation and beta 1 receptor agonism at higher doses. This results in increased cardiac output. Since both heart rate and blood pressure are raised, there is less overall myocardial ischaemia. Dobutamine is a predominantly beta 1 receptor agonist with weak beta 2 and alpha receptor agonist properties. Noradrenaline is a catecholamine type agent and predominantly acts as an alpha receptor agonist and serves as a peripheral vasoconstrictor. Phosphodiesterase inhibitors such as milrinone act specifically on the cardiac phosphodiesterase and increase cardiac output. Inotrope Cardiovascular receptor action Adrenaline α-1, α-2, β-1, β-2 Noradrenaline α-1,( α-2), (β-1), (β-2) Dobutamine β-1, (β 2) Dopamine (α-1), (α-2), (β-1), D-1,D-2 Minor receptor effects in brackets Effects of receptor binding α-1, α-2 vasoconstriction β-1 increased cardiac contractility and HR β-2 vasodilatation D-1 renal and spleen vasodilatation D-2 inhibits release of noradrenaline

Answer 66

Correct Answer: 3. Place in futura splint and review in fracture clinic Explanation: Tenderness in the anatomical snuffbox following a fall onto an outstretched hand is highly suggestive of a scaphoid fracture, even if initial X-rays are normal. Scaphoid fractures may not always be visible on initial X-rays and can lead to complications such as nonunion or avascular necrosis if not properly managed. Appropriate management includes: • Immobilization: Placing the wrist in a splint, such as a futura splint, to immobilize the area and prevent further injury. • Follow-up: Arranging for a review in the fracture clinic where further imaging (e.g., repeat X-rays, MRI, or CT) can be performed if needed to confirm the diagnosis. Options not chosen: • Discharge with reassurance: Inappropriate due to the high suspicion of a scaphoid fracture. • Place in arm sling and discharge: Insufficient as it does not adequately immobilize the wrist. • Admit for surgical exploration: Not indicated at this stage without a confirmed fracture. • Apply an external fixation device: Unnecessary for a suspected scaphoid fracture without a confirmed diagnosis. Therefore, the best course of action is to place the wrist in a futura splint and arrange for a review in the fracture clinic. This could well be a scaphoid fracture and should be temporarily immobilised pending further review. A futura splint will immobilise better than an arm sling for this problem. Fracture management Bony injury resulting in a fracture may arise from trauma (excessive forces applied to bone), stress related (repetitive low velocity injury) or pathological (abnormal bone which fractures during normal use of following minimal trauma) Diagnosis involves not just evaluating the fracture ; such as site and type of injury but also other associated injuries and distal neurovascular deficits. This may entail not just clinical examination but radiographs of proximal and distal joints. When assessing x-rays it is important to assess for changes in length of the bone, the angulation of the distal bone, rotational effects, presence of material such as glass. Fracture types Fracture type Description Oblique fracture Fracture lies obliquely to long axis of bone Comminuted fracture >2 fragments Segmental fracture More than one fracture along a bone Transverse fracture Perpendicular to long axis of bone Spiral fracture Severe oblique fracture with rotation along long axis of bone Open Vs Closed It is also important to distinguish open from closed injuries. The most common classification system for open fractures is the Gustilo and Anderson classification system (given below): Grade Injury 1 Low energy wound <1cm 2 Greater than 1cm wound with moderate soft tissue damage 3 High energy wound > 10cm with extensive soft tissue damage 3 A (sub group of 3) Adequate soft tissue coverage 3 B (sub group of 3) Inadequate soft tissue coverage 3 C (sub group of 3) Associated arterial injury Key points in management of fractures Immobilise the fracture including the proximal and distal joints Carefully monitor and document neurovascular status, particularly following reduction and immobilisation Manage infection including tetanus prophylaxis IV broad spectrum antibiotics for open injuries As a general principle all open fractures should be thoroughly debrided ( and internal fixation devices avoided or used with extreme caution) Open fractures constitute an emergency and should be debrided and lavaged within 6 hours of injury

Answer 67

The symptoms are typical for sialolithiasis. The stones most commonly form in the submandibular gland and therefore may occlude Whartons duct. Stensens duct drains the parotid gland. Submandibular glands- disease Physiology The submandibular glands secrete approximately 800- 1000ml saliva per day. They typically produce mixed seromucinous secretions. When parasympathetic activity is dominant; the secretions will be more serous. The parasympathetic fibres are derived from the chorda tympani nerves and the submandibular ganglion. Sensory fibres are conveyed by the lingual branch of the mandibular nerve. Sialolithiasis 80% of all salivary gland calculi occur in the submandibular gland 70% of the these calculi are radio-opaque Stones are usually composed of calcium phosphate or calcium carbonate Patients typically develop colicky pain and post prandial swelling of the gland Investigation involves sialography to demonstrate the site of obstruction and associated other stones Stones impacted in the distal aspect of Whartons duct may be removed orally, other stones and chronic inflammation will usually require gland excision Sialadenitis Usually occurs as a result of Staphylococcus aureus infection Pus may be seen leaking from the duct, erythema may also be noted Development of a sub mandibular abscess is a serious complication as it may spread through the other deep fascial spaces and occlude the airway Submandibular tumours Only 8% of salivary gland tumours affect the sub mandibular gland Of these 50% are malignant (usually adenoid cystic carcinoma) Diagnosis usually involves fine needle aspiration cytology Imaging is with CT and MRI In view of the high prevalence of malignancy, all masses of the submandibular glands should generally be excised.

Answer 68

Given the clinical scenario of a 20-year-old man with bloody diarrhea, a failing response to intravenous steroids, and development of megacolon, the most appropriate course of action is a surgical intervention. The options of further medical management, such as doubling the steroid dose, are unlikely to be effective at this stage due to the risk of perforation and other complications associated with toxic megacolon. The most appropriate course of action is: Undertake a sub total colectomy and end ileostomy Explanation: 1. Development of Megacolon: The patient has developed a toxic megacolon, which is a severe complication of colitis characterized by extreme dilatation of the colon and potential for perforation. This condition requires urgent surgical intervention. 2. Failure of Medical Management: The patient has been on intravenous steroids for 5 days without improvement, indicating that medical management has failed. 3. Rising Complications: With falling hemoglobin levels and static inflammatory markers, the patient’s condition is worsening, necessitating immediate surgery. A subtotal colectomy with an end ileostomy is typically recommended as it removes the diseased colon and diverts fecal stream, reducing the risk of perforation and sepsis, and stabilizing the patient. Pan proctocolectomy should not be performed in acute unwell patients Loop ileostomy is not conventional management of UC This man requires a sub total colectomy. Conservative management has failed. Patients with ulcerative colitis should undergo colectomy if there is no significant improvement in 5-7 days after initiating medical therapy if they have a severe attack of the disease. To undertake a pan proctocolectomy in an acutely unwell patient is very high risk and most unwise. Management of the rectum is generally left until the patient is more stable. IBD Ulcerative colitis Vs Crohns Crohn's disease Ulcerative colitis Distribution Mouth to anus Rectum and colon Macroscopic changes Cobblestone appearance, apthoid ulceration Contact bleeding Depth of disease Transmural inflammation Superficial inflammation Distribution pattern Patchy Continuous Histological features Granulomas (non caseating epithelioid cell aggregates with Langerhans' giant cells) Crypt abscesses, Inflammatory cells in the lamina propria Surgical treatment Ulcerative colitis In UC the main place for surgery is when medical treatment has failed, in the emergency setting this will be a sub total colectomy, end ileostomy and a mucous fistula. Electively it will be a pan proctocolectomy, an ileoanal pouch may be a selected option for some. Remember that longstanding UC increases colorectal cancer risk. Crohn's disease Unlike UC Crohn's patients need to avoid surgeons, minimal resections are the rule. They should not have ileoanal pouches as they will do poorly with them. Management of Crohn's ano rectal sepsis is with a minimal approach, simply drain sepsis and use setons to facilitate drainage. Definitive fistula surgery should be avoided.

Answer 69

A unilateral dilated pupil is a classic sign of transtentorial herniation. The medial aspect of the temporal lobe (uncus) herniates across the tentorium and causes pressure on the ipsilateral oculomotor nerve, interrupting parasympathetic input to the eye and resulting in a dilated pupil. In addition the brainstem is compressed. As the ipsilateral oculomotor nerve is being compressed, craniotomy (rather than Burr Holes) should be made on the ipsilateral side. Head injury Patients who suffer head injuries should be managed according to ATLS principles and extra cranial injuries should be managed alongside cranial trauma. Inadequate cardiac output will compromise CNS perfusion irrespective of the nature of the cranial injury. Types of traumatic brain injury Extradural haematoma Bleeding into the space between the dura mater and the skull. Often results from acceleration-deceleration trauma or a blow to the side of the head. The majority of extradural haematomas occur in the temporal region where skull fractures cause a rupture of the middle meningeal artery. Features Raised intracranial pressure Some patients may exhibit a lucid interval Subdural haematoma Bleeding into the outermost meningeal layer. Most commonly occur around the frontal and parietal lobes. May be either acute or chronic. Risk factors include old age and alcoholism. Slower onset of symptoms than a extradural haematoma. Subarachnoid haemorrhage Usually occurs spontaneously in the context of a ruptured cerebral aneurysm, but may be seen in association with other injuries when a patient has sustained a traumatic brain injury. Pathophysiology Primary brain injury may be focal (contusion/ haematoma) or diffuse (diffuse axonal injury) Diffuse axonal injury occurs as a result of mechanical shearing following deceleration, causing disruption and tearing of axons Intra-cranial haematomas can be extradural, subdural or intracerebral, while contusions may occur adjacent to (coup) or contralateral (contre-coup) to the side of impact Secondary brain injury occurs when cerebral oedema, ischaemia, infection, tonsillar or tentorial herniation exacerbates the original injury. The normal cerebral auto regulatory processes are disrupted following trauma rendering the brain more susceptible to blood flow changes and hypoxia The Cushings reflex (hypertension and bradycardia) often occurs late and is usually a pre terminal event Management Where there is life threatening rising ICP such as in extra dural haematoma and whilst theatre is prepared or transfer arranged use of IV mannitol/ frusemide may be required. Diffuse cerebral oedema may require decompressive craniotomy Exploratory Burr Holes have little management in modern practice except where scanning may be unavailable and to thus facilitate creation of formal craniotomy flap Depressed skull fractures that are open require formal surgical reduction and debridement, closed injuries may be managed non operatively if there is minimal displacement. ICP monitoring is appropriate in those who have GCS 3-8 and normal CT scan. ICP monitoring is mandatory in those who have GCS 3-8 and abnormal CT scan. Hyponatraemia is most likely to be due to syndrome of inappropriate ADH secretion. Minimum of cerebral perfusion pressure of 70mmHg in adults. Minimum cerebral perfusion pressure of between 40 and 70 mmHg in children. Interpretation of pupillary findings in head injuries Pupil size Light response Interpretation Unilaterally dilated Sluggish or fixed 3rd nerve compression secondary to tentorial herniation Bilaterally dilated Sluggish or fixed Poor CNS perfusion Bilateral 3rd nerve palsy Unilaterally dilated or equal Cross reactive (Marcus - Gunn) Optic nerve injury Bilaterally constricted May be difficult to assess Opiates Pontine lesions Metabolic encephalopathy Unilaterally constricted Preserved Sympathetic pathway disruption

Answer 70

D In established aneurysmal disease there is dilation of all layers of the arterial wall and loss of both elastin and collagen. The primary event is loss of elastic fibres with subsequent degradation of collagen fibres. Pathology of abdominal aortic aneurysm Abdominal aortic aneurysms occur primarily as a result of the failure of elastic proteins within the extracellular matrix. Aneurysms typically represent dilation of all layers of the arterial wall. Most aneurysms are caused by degenerative disease. After the age of 50 years the normal diameter of the infrarenal aorta is 1.5cm in females and 1.7cm in males. Diameters of 3cm and greater, are considered aneurysmal. The pathophysiology involved in the development of aneurysms is complex and the primary event is loss of the intima with loss of elastic fibres from the media. This process is associated with, and potentiated by, increased proteolytic activity and lymphocytic infiltration. Major risk factors for the development of aneurysms include smoking and hypertension. Rare but important causes include syphilis and connective tissues diseases such as Ehlers Danlos type 1 and Marfans syndrome.

Answer 71

Epirubicin is an anthracycline chemotherapeutic agent primarily used in the treatment of various cancers, including breast cancer. The primary mode of action of epirubicin is: Intercalation of DNA Explanation: 1. Intercalation of DNA: Epirubicin works by intercalating into DNA, which means it inserts itself between DNA base pairs. This intercalation disrupts the structure of the DNA helix, inhibiting DNA replication and transcription. Additionally, it stabilizes the topoisomerase II-DNA complex, preventing the religation of the DNA strands and leading to apoptosis of the cancer cells. 2. Antimetabolite: Antimetabolites are drugs that interfere with the normal metabolism of cells, usually by mimicking the normal substrates of key enzymes, but this is not the primary action of epirubicin. 3. Monoclonal antibody to epidermal growth factor: Monoclonal antibodies target specific proteins, such as the epidermal growth factor receptor (EGFR), but epirubicin is not a monoclonal antibody. 4. Inhibition of DNA gyrase: DNA gyrase is an enzyme targeted by some antibiotics, particularly in bacteria, but it is not the target of epirubicin. 5. Inhibition of topoisomerase 1: Epirubicin primarily inhibits topoisomerase II, not topoisomerase I. Therefore, epirubicin’s primary mode of action is intercalation of DNA.

Answer 72

The lesser omentum will need to be divided. During a radical gastrectomy this forms one of the nodal stations that will need to be taken. Coeliac axis The coeliac axis has three main branches. Left gastric Hepatic: branches-Right Gastric, Gastroduodenal, Superior Pancreaticoduodenal, Cystic (occasionally). Splenic: branches- Pancreatic, Short Gastric, Left Gastroepiploic It occasionally gives off one of the inferior phrenic arteries. Relations Anteriorly Lesser omentum Right Right coeliac ganglion and caudate process of liver Left Left coeliac ganglion and gastric cardia Inferiorly Upper border of pancreas and renal vein

Answer 73

The most likely sensory impairment that the patient may notice post-operatively is: Parasthesia overlying the angle of the jaw Explanation: The middle meningeal artery is a branch of the maxillary artery and supplies the meninges of the brain. During a craniotomy to control hemorrhage from the middle meningeal artery, nearby structures, including the auriculotemporal nerve, can be affected. The auriculotemporal nerve is a branch of the mandibular nerve (V3) and provides sensory innervation to the skin over the temple and the anterior portion of the ear, as well as the temporomandibular joint (TMJ). Given this anatomical relationship, damage or manipulation of the auriculotemporal nerve during the surgery could lead to parasthesia (abnormal sensation) overlying the angle of the jaw. This is because the auriculotemporal nerve innervates that region. Other options do not align as closely with the anatomical course and innervation area of the middle meningeal artery and its surrounding structures: • Parasthesia of the ipsilateral external ear: This would more likely involve the great auricular nerve or lesser occipital nerve. • Loss of taste sensation from the anterior two-thirds of the tongue: This involves the chorda tympani branch of the facial nerve (VII). • Loss of sensation from the ipsilateral side of the tongue: This involves the lingual nerve, a branch of the mandibular nerve (V3). • Loss of taste from the posterior two-thirds of the tongue: This involves the glossopharyngeal nerve (IX).

Answer 74

The terminal part of the thoracic duct inserts into the left subclavian vein and it passes posterior to the jugular vein. Internal jugular vein Each jugular vein begins in the jugular foramen, where they are the continuation of the sigmoid sinus. They terminate at the medial end of the clavicle where they unite with the subclavian vein. The vein lies within the carotid sheath throughout its course. Below the skull the internal carotid artery and last four cranial nerves are anteromedial to the vein. Thereafter it is in contact medially with the internal (then common) carotid artery. The vagus lies posteromedially. At its superior aspect, the vein is overlapped by sternocleidomastoid and covered by it at the inferior aspect of the vein. Below the transverse process of the atlas it is crossed on its lateral side by the accessory nerve. At its mid point it is crossed by the inferior root of the ansa cervicalis. Posterior to the vein are the transverse processes of the cervical vertebrae, the phenic nerve as it descends on the scalenus anterior, and the first part of the subclavian artery. On the left side its also related to the thoracic duct.

Answer 75

Chronic rejection of renal transplants is mediated via T lymphocytes and is therefore a type IV hypersensitivity reaction. This process can be mitigated by immunosupression. Organ Transplant A number of different organ and tissue transplants are now available. In many cases an allograft is performed, where an organ is transplanted from one individual to another. Allografts will elicit an immune response and this is one of the main reasons for organ rejection. Graft rejection occurs because allografts have allelic differences at genes that code immunohistocompatability complex genes. The main antigens that give rise to rejection are: ABO blood group Human leucocyte antigens (HLA) Minor histocompatability antigens ABO Matching ABO incompatibility will result in early organ rejection (hyperacute) because of pre existing antibodies to other groups. Group O donors can give organs to any type of ABO recipient whereas group AB donor can only donate to AB recipient. HLA System The four most important HLA alleles are: HLA A HLA B HLA C HLA DR An ideal organ match would be one in which all 8 alleles are matched (remember 2 from each parent, four each = 8 alleles). Modern immunosuppressive regimes help to manage the potential rejection due to HLA mismatching. However, the greater the number of mismatches the worse the long term outcome will be. T lymphocytes will recognise antigens bound to HLA molecules and will then become activated. Clonal expansion then occurs with a response directed against that antigen. Types of organ rejection Hyperacute. This occurs immediately through presence of pre formed antibodies (such as ABO incompatibility). Acute. Occurs during the first 6 months and is usually T cell mediated. Usually tissue infiltrates and vascular lesions. Chronic. Occurs after the first 6 months. Vascular changes predominate. Hyperacute Renal transplants at greatest risk and liver transplants at least risk. Although ABO incompatibility and HLA Class I incompatible transplants will all fare worse in long term. Acute All organs may undergo acute rejection. Mononuclear cell infiltrates predominate. All types of transplanted organ are susceptible and it may occur in up to 50% cases. Chronic Again all transplants with HLA mismatch may suffer this fate. Previous acute rejections and other immunosensitising events all increase the risk. Vascular changes are most prominent with myointimal proliferation leading to organ ischaemia. Organ specific changes are also seen such as loss of acinar cells in pancreas transplants and rapidly progressive coronary artery disease in cardiac transplants. Surgical overview-Renal transplantation A brief overview of the steps involved in renal transplantation is given. Patients with end stage renal failure who are dialysis dependent or likely to become so in the immediate future are considered for transplant. Exclusion criteria include; active malignancy, old age (due to limited organ availability). Patients are medically optimised. Donor kidneys, these may be taken from live related donors and close family, members may have less HLA mismatch than members of the general population. Laparoscopic donor nephrectomy further minimises the operative morbidity for the donor. Other organs are typically taken from brain dead or dying patients who have a cardiac arrest and in whom resuscitation is futile. The key event is to minimise the warm ischaemic time in the donor phase. The kidney once removed is usually prepared on the bench in theatre by the transplant surgeon immediately prior to implantation and factors such as accessory renal arteries and vessel length are assessed and managed. For first time recipients the operation is performed under general anaesthesia. A Rutherford-Morison incision is made on the preferred side. This provides excellent extraperitoneal access to the iliac vessels. The external iliac artery and vein are dissected out and following systemic heparinisation are cross clamped. The vein and artery are anastamosed to the iliacs and the clamps removed. The ureter is then implanted into the bladder and a stent is usually placed to maintain patency. The wounds are then closed and the patient recovered from surgery. In the immediate phase a common problem encountered in cadaveric kidneys is acute tubular necrosis and this tends to resolve. Graft survival times from cadaveric donors are typically of the order of 9 years and monozygotic twin transplant (live donor) may survive as long as 25 years.

Answer 76

Splenic trauma is nearly always managed conservatively. Hilar injuries (grade IV) are less amenable to this and will tend to come to surgery. The most appropriate course of action for a 10-year-old child with a grade III splenic laceration and stable vital signs is: Admit the child to the high dependency unit for close monitoring Explanation: In pediatric patients, the management of splenic injuries often favors non-operative treatment, especially in the context of stable vital signs. Grade III splenic lacerations, while significant, can often be managed conservatively if the patient remains hemodynamically stable. Close monitoring in a high dependency unit (HDU) is appropriate to ensure any changes in the child’s condition are promptly addressed. This approach minimizes the risks associated with surgery and preserves splenic function, which is important for immunological reasons. • Immediate laparotomy and splenectomy: This is typically reserved for patients who are hemodynamically unstable or have ongoing significant bleeding that cannot be controlled non-operatively. • Laparoscopy and laparoscopic splenectomy: Similar to open splenectomy, this is more invasive and generally not the first choice in hemodynamically stable pediatric patients. • Splenic artery embolisation: This is usually considered for patients with ongoing bleeding but can often be avoided in stable children. • Laparotomy and splenic repair: This is an option if non-operative management fails or if there is significant concern for complications that cannot be managed non-operatively. However, in a stable child, initial non-operative management is preferred. Therefore, admitting the child to the HDU for close monitoring is the most appropriate and conservative approach, given the current stability of the patient. Trauma management The cornerstone of trauma management is embodied in the principles of ATLS. Following trauma there is a trimodal death distribution: Immediately following injury. Typically as result of brain or high spinal injuries, cardiac or great vessel damage. Salvage rate is low. In early hours following injury. In this group deaths are due to phenomena such as splenic rupture, sub dural haematomas and haemopneumothoraces In the days following injury. Usually due to sepsis or multi organ failure. Aspects of trauma management ABCDE approach. Tension pneumothoraces will deteriorate with vigorous ventilation attempts. External haemorrhage is managed as part of the primary survey. As a rule tourniquets should not be used. Blind application of clamps will tend to damage surrounding structures and packing is the preferred method of haemorrhage control. Urinary catheters and naso gastric tubes may need inserting. Be wary of basal skull fractures and urethral injuries. Patients with head and neck trauma should be assumed to have a cervical spine injury until proven otherwise. Thoracic injuries Simple pneumothorax Mediastinal traversing wounds Tracheobronchial tree injury Haemothorax Blunt cardiac injury Diaphragmatic injury Aortic disruption Pulmonary contusion Management of thoracic trauma Simple pneumothorax insert chest drain. Aspiration is risky in trauma as pneumothorax may be from lung laceration and convert to tension pneumothorax. Mediastinal traversing wounds These result from situations like stabbings. Exit and entry wounds in separate hemithoraces. The presence of a mediastinal haematoma indicates the likelihood of a great vessel injury. All patients should undergo CT angiogram and oesophageal contrast swallow. Indications for thoracotomy are largely related to blood loss and will be addressed below. Tracheobronchial tree injury Unusual injuries. In blunt trauma most injuries occur within 4cm of the carina. Features suggesting this injury include haemoptysis and surgical emphysema. These injuries have a very large air leak and may have tension pneumothorax. Haemothorax Usually caused by laceration of lung vessel or internal mammary artery by rib fracture. Patients should all have a wide bore 36F chest drain. Indications for thoracotomy include loss of more than 1.5L blood initially or ongoing losses of >200ml per hour for >2 hours. Cardiac contusions Usually cardiac arrhythmias, often overlying sternal fracture. Perform echocardiography to exclude pericardial effusions and tamponade. Risk of arrhythmias falls after 24 hours. Diaphragmatic injury Usually left sided. Direct surgical repair is performed. Traumatic aortic disruption Commonest cause of death after RTA or falls. Usually incomplete laceration near ligamentum arteriosum. All survivors will have contained haematoma. Only 1-2% of patients with this injury will have a normal chest x-ray. Pulmonary contusion Common and lethal. Insidious onset. Early intubation and ventilation. Abdominal trauma Deceleration injuries are common. In blunt trauma requiring laparotomy the spleen is most commonly injured (40%) Stab wounds traverse structures most commonly liver (40%) Gunshot wounds have variable effects depending upon bullet type. Small bowel is most commonly injured (50%) Patients with stab wounds and no peritoneal signs up to 25% will not enter the peritoneal cavity Blood at urethral meatus suggests a urethral tear High riding prostate on PR = urethral disruption Mechanical testing for pelvic stability should only be performed once Investigations in abdominal trauma Diagnostic Peritoneal Lavage Abdominal CT scan USS Indication Document bleeding if hypotensive Document organ injury if normotensive Document fluid if hypotensive Advantages Early diagnosis and sensitive; 98% accurate Most specific for localising injury; 92 to 98% accurate Early diagnosis, non invasive and repeatable; 86 to 95% accurate Disadvantages Invasive and may miss retroperitoneal and diaphragmatic injury Location of scanner away from facilities, time taken for reporting, need for contrast Operator dependent and may miss retroperitoneal injury Amylase may be normal following pancreatic trauma Urethrography if suspected urethral injury

Answer 77

Given that the child is well, the risks of removing the pellet are not outweighed by the benefits and it should be left in situ at this stage. Management of acute cases- Paediatric Children will often insert objects into orifices such as the nose and external auditory meatus Assessment includes assessment of airway and haemodynamic status Where the airway is not immediately threatened decisions can be made as to whether to manage in the emergency department or transfer to theatre In general children do not tolerate procedures well and it is usually safer to remove objects in theatre and under general anaesthesia with a secure airway A chest x-ray is required to ensure that no object is present in the chest, not all objects are radioopaque. However, signs such as focal consolidation may indicate small airway obstruction In the case of small bore missile injuries the decision relating to surgery depends on the size of the missile and its location. Airgun pellets are a common culprit, if there is a long time interval between the incident and presentation and the object has not caused any significant problems then it may be best left alone Airgun pellets (and glass) lodged in the soft tissues are usually notoriously difficult to localise and extract, no matter how superficial. Removal in theatre is usually the best option. If the object is radioopaque then an image intensifier should be used

Answer 78

This is a typical presentation of pseudogout. An elevated transferrin saturation may indicate haemochromatosis, a recognised cause of pseudogout. A high ferritin level is also seen in haemochromatosis but can be raised in a variety of infective and inflammatory processes, including pseudogout, as part of an acute phase response. Pseudogout Pseudogout is a form of microcrystal synovitis caused by the deposition of calcium pyrophosphate dihydrate in the synovium Risk factors hyperparathyroidism hypothyroidism haemochromatosis acromegaly low magnesium, low phosphate Wilson's disease Features knee, wrist and shoulders most commonly affected joint aspiration: weakly-positively birefringent rhomboid shaped crystals x-ray: chondrocalcinosis Management aspiration of joint fluid, to exclude septic arthritis NSAIDs or intra-articular, intra-muscular or oral steroids as for gout

Answer 79

Prilocaine is a recognised cause of methaemoglobinaemia, this is characterised by the development of cyanosis and dyspnoea. This disorder occurs because of the change haemoglobin to a ferric subtype rather than ferrous (Fe2+). This type of change shifts the oxygen dissociation curve to the left and tissue hypoxia occurs. Methylene blue will revert the haemoglobin to the ferrous type and reverse this effect. Local anaesthetic toxicity Toxicity results from either accidental intravascular injection (rapid onset of symptoms-usually correct dose), or from excessive dosage (slower onset). Local anaesthetic agents not only exert a membrane stabilising effect on peripheral nerves but will also act on excitable membranes within the CNS and Heart. The sensory neurones in the CNS are suppressed before the motor ones. As a result the early symptoms will typically be those of circumoral paraesthesia and tinnitus, followed by falling GCS and eventually coma. Management of toxicity Stop injecting the anaesthetic agent High flow 100% oxygen via face mask Cardiovascular monitoring Administer lipid emulsion (Intralipid 20%) at 1.5ml/Kg over 1 minute as a bolus Consider lipid emulsion infusion, at 0.25ml/ Kg/ minute If toxicity due to prilocaine then administer methylene blue Safe doses 10ml of lignocaine 1% contains 100mg of drug, this would constitute 70% of the maximum safe dose in a 50 kg patient. Up to 7mg / kg can be administered if adrenaline is added to the solution. Doses of local anaesthetics Agent Dose plain Dose with adrenaline Lignocaine 3mg/Kg 7mg/Kg Bupivicane 2mg/Kg 2mg/Kg Prilocaine 6mg/Kg 9mg/Kg These are a guide only as actual doses depend on site of administration, tissue vascularity and co-morbidities.

Answer 80

t is important to be aware of what can falsely elevate 5-HIAA to avoid diagnosing carcinoid syndrome incorrectly. These include: Food: spinach, cheese, wine, caffeine, tomatoes Drugs: Naproxen, Monoamine oxidase inhibitors Recent surgery Carcinoid syndrome Carcinoid tumours secrete serotonin Originate in neuroendocrine cells mainly in the intestine (midgut-distal ileum/appendix) Can occur in the rectum, bronchi Hormonal symptoms mainly occur when disease spreads outside the bowel Clinical features Onset: insidious over many years Flushing face Palpitations Pulmonary valve stenosis and tricuspid regurgitation causing dyspnoea Asthma Severe diarrhoea (secretory, persists despite fasting) Investigation 5-HIAA in a 24-hour urine collection Somatostatin receptor scintigraphy CT scan Blood testing for chromogranin A Treatment Octreotide Surgical removal

Answer 81

The CSF flows from the 3rd to the 4th ventricle via the Aqueduct of Sylvius. Cerebrospinal fluid The CSF fills the space between the arachnoid mater and pia mater (covering surface of the brain). The total volume of CSF in the brain is approximately 150ml. Approximately 500 ml is produced by the ependymal cells in the choroid plexus (70%), or blood vessels (30%). It is reabsorbed via the arachnoid granulations which project into the venous sinuses. Circulation 1. Lateral ventricles (via foramen of Munro) 2. 3rd ventricle 3. Cerebral aqueduct (aqueduct of Sylvius) 4. 4th ventricle 5. Subarachnoid space (via foramina of Magendie and Luschka) 6. Reabsorbed into the venous system via arachnoid granulations into superior sagittal sinus Composition Glucose: 50-80mg/dl Protein: 15-40 mg/dl Red blood cells: Nil White blood cells: 0-3 cells/ mm3

Answer 82

Adenocarcinomas are the most common tumour type present in never smokers. They are usually located at the periphery. Lung cancer Lung cancers may be classified according to histological subtypes. The main distinction is between small cell and non small cell lung cancer. Non small cell lung cancer is the most common variant and accounts for 80% of all lung cancers. Non small cell lung cancer These share common features of prognosis and management. They comprise the following tumours: Squamous cell carcinoma (25% cases) Adenocarcinoma (40% cases) Large cell carcinoma (10% cases) Paraneoplastic features and early disease dissemination are less likely than with small cell lung carcinoma. Adenocarcinoma is the most common lung cancer type encountered in never smokers. Small cell lung carcinoma Small cell lung carcinomas are comprised of cells with a neuro endocrine differentiation. The neuroendocrine hormones may be released from these cells with a wide range of paraneoplastic associations. These tumours are strongly associated with smoking and will typically arise in the larger airways. They disseminate early in the course of the disease and although they are usually chemosensitive this seldom results in long lasting remissions.

Answer 83

During a TEP repair of inguinal hernia the only structure to lie posterior to the mesh is peritoneum. The question is really only asking which structure lies posterior to the rectus abdominis muscle. Since this region is below the arcuate line, the transversalis fascia and peritoneum lie posterior to it. Bucks fascia lies in the penis. Rectus abdominis muscle The rectus sheath is formed by the aponeuroses of the lateral abdominal wall muscles. The rectus sheath has a composition that varies according to anatomical level. 1. Above the costal margin the anterior sheath is composed of external oblique aponeurosis, the costal cartilages are posterior to it. 2. From the costal margin to the arcuate line, the anterior rectus sheath is composed of external oblique aponeurosis and the anterior part of the internal oblique aponeurosis. The posterior part of the internal oblique aponeurosis and transversus abdominis form the posterior rectus sheath. 3. Below the arcuate line the aponeuroses of all the abdominal muscles lie in anterior aspect of the rectus sheath. Posteriorly lies the transversalis fascia and peritoneum. The arcuate line is the point at which the inferior epigastric vessels enter the rectus sheath.

Answer 84

After separation of the cord there should not be any discharge from the umbilicus. The presence of clear fluid points towards this being urine rather than bowel content coming from the umbilicus. A patent urachus implies a persistent collection to the bladder, allowing small amounts of urine to leak but the patient often remains completely well. A patent urachus - correct A patent vitello-intestinal duct - you would expect bowel content, not clear fluid with a connection to the bowel A urachal cyst - a urachal cyst typically will not drain as the urachal tract is obliterated on either side of the cyst An exomphalos - this is an abdominal wall defect with the bowel covered by the cord structures and would be identified soon after birth An umbilical granuloma - a granuloma may leak small amounts of fluid but typically is more serosanguinous The correct answer is: A patent urachus

Answer 85

The most compelling reason for treating a pituitary microadenoma causing acromegaly is: Avoidance of cardiovascular complications Explanation: Acromegaly is associated with significant morbidity and mortality due to its systemic effects. Cardiovascular complications are the leading cause of death in patients with acromegaly, primarily due to hypertension, cardiomyopathy, and other related issues. Effective treatment of the pituitary adenoma can reduce the excess production of growth hormone and mitigate these severe cardiovascular risks. • Avoidance of colonic cancer: While there is an increased risk of colonic polyps and cancer in acromegaly patients, it is not the most immediate or compelling reason for treatment compared to cardiovascular risks. • Avoidance of diabetes: Diabetes is a common complication of acromegaly due to growth hormone-induced insulin resistance, but cardiovascular complications are more critical. • Avoidance of optic pathway compression: This is a concern for larger pituitary adenomas (macroadenomas) that can compress adjacent structures. Microadenomas (less than 10 mm in size) typically do not cause optic pathway compression. • Avoidance of radiological progression: Preventing tumor growth is important, but the primary focus is on mitigating the clinical consequences of hormone excess, particularly cardiovascular risks. Therefore, the most compelling reason for treating a pituitary microadenoma in a patient with acromegaly is to avoid cardiovascular complications, which have the most significant impact on morbidity and mortality.

Answer 86

The approach described for the washout of the hip joint in septic arthritis involves the anterior approach between the rectus femoris and the gluteus medius muscles. This approach utilizes an internervous plane to minimize the risk of nerve damage. The correct internervous plane for this approach is: Femoral nerve and superior gluteal nerve Explanation: • The femoral nerve innervates the rectus femoris muscle. • The superior gluteal nerve innervates the gluteus medius muscle. Thus, the correct answer is: Femoral nerve and superior gluteal nerve

Answer 87

Among the visceral anastomoses listed, the one with the lowest risk of anastomotic leak, assuming all are constructed in ideal circumstances, is generally considered to be: Stapled ileocolic anastomosis Explanation: • Stapled ileocolic anastomosis typically has a lower risk of anastomotic leak compared to other types of anastomoses because the ileum and colon are relatively well-vascularized and less prone to tension and technical difficulties. • Hand-sewn anastomoses, particularly in complex areas like the oesophagojejunal junction, carry higher risks due to the technical challenges and the poor vascularity of the tissues involved. • Stapled colorectal anastomoses, even when defunctioned with loop ileostomy or loop colostomy, have higher risks of leaks compared to ileocolic anastomoses because the rectal area is more prone to complications due to factors like tension, poor blood supply, and potential for contamination. Therefore, the correct answer is: Stapled ileocolic anastomosis For a visceral anastomosis to heal, three factors need to be satisfied: 1. Mucosal- mucosal apposition 2. A good blood supply 3. No tension The more these are compromised, the higher the leak rate. Rectal and oesophageal surgery have some of the highest rates of anastomotic leakage. Following anterior resection leaks are quoted to occur in up to 10% of cases. Small bowel anastomoses are the most technically forgiving. Factors increasing the risk of anastamotic leakage include previous irradiation, sepsis, malnutrition, poor blood supply and poor technique. The defunctioning of rectal anastomoses may reduce the clinical impact of anastomotic leak and make it amenable to percutaneous drainage, but does not necessarily reduce the incidence of leaks themselves.

Answer 88

The outermost covering of the spermatic cord is derived from the external oblique aponeurosis.This layer is added as the cord passes through the superficial inguinal ring. Scrotal and testicular anatomy Spermatic cord Formed by the vas deferens and is covered by the following structures: Layer Origin Internal spermatic fascia Transversalis fascia Cremasteric fascia From the fascial coverings of internal oblique External spermatic fascia External oblique aponeurosis Contents of the cord Vas deferens Transmits sperm and accessory gland secretions Testicular artery Branch of abdominal aorta supplies testis and epididymis Artery of vas deferens Arises from inferior vesical artery Cremasteric artery Arises from inferior epigastric artery Pampiniform plexus Venous plexus, drains into right or left testicular vein Sympathetic nerve fibres Lie on arteries, the parasympathetic fibres lie on the vas Genital branch of the genitofemoral nerve Supplies cremaster Lymphatic vessels Drain to lumbar and para-aortic nodes Scrotum Composed of skin and closely attached dartos fascia. Arterial supply from the anterior and posterior scrotal arteries Lymphatic drainage to the inguinal lymph nodes Parietal layer of the tunica vaginalis is the innermost layer Testes The testes are surrounded by the tunica vaginalis (closed peritoneal sac). The parietal layer of the tunica vaginalis adjacent to the internal spermatic fascia. The testicular arteries arise from the aorta immediately inferiorly to the renal arteries. The pampiniform plexus drains into the testicular veins, the left drains into the left renal vein and the right into the inferior vena cava. Lymphatic drainage is to the para-aortic nodes.

Answer 89

The obstruction is most likely to be the result of an annular pancreas. The dorsal and ventral pancreas structures initially lie opposite each other. However, the ventral pancreas rotates to eventually fuse with the dorsal. Sometimes this can result in an annular pancreas and some patients can develop obstruction as a result. Pancreatic embryology The pancreas develops from a ventral and dorsal entodermal outgrowth from the duodenum. The ventral arises close to, or in common with, the hepatic diverticulum, and the larger, dorsal outgrowth arises slightly cranial to the ventral and extends into the mesoduodenum and dorsal mesogastrium. As a result of the differential growth in the duodenal wall, the point of attachment of the ventral outgrowth with the undivided stem of the hepatic diverticulum and the ventral mesentery are displaced around the right hand side of the duodenum to a dorsal position. As a result, the two pancreatic remnants eventually lie together and then become fused. In this process the ventral rudiment forms the uncinate process and the adjacent region of the head, while the dorsal forms the anterior part of the head, the body and the tail of the pancreas. At the time of fusion, the ducts become joined. This occurs in a manner that results in the dorsal remnant being drained by the duct of the ventral remnant, this composite duct being named the pancreatic duct.

Answer 90

Renal transplant HLA matching - DR is the most important. Renal transplant:HLA typing and graft failure The human leucocyte antigen (HLA) system is the name given to the major histocompatibility complex (MHC) in humans. It is coded for on chromosome 6. Some basic points on the HLA system Class 1 antigens include A, B and C. Class 2 antigens include DP,DQ and DR When HLA matching for a renal transplant the relative importance of the HLA antigens are as follows DR > B > A Graft survival 1 year = 90%, 10 years = 60% for cadaveric transplants 1 year = 95%, 10 years = 70% for living-donor transplants Post-op problems ATN of graft Vascular thrombosis Urine leakage UTI Hyperacute acute rejection Due to antibodies against donor HLA type 1 antigens Rarely seen due to HLA matching Acute graft failure (< 6 months) Usually due to mismatched HLA Other causes include cytomegalovirus infection Management: give steroids, if resistant use monoclonal antibodies Causes of chronic graft failure (> 6 months) Chronic allograft nephropathy Ureteric obstruction Recurrence of original renal disease (MCGN > IgA > FSGS)

Answer 91

Mnemonic for drugs causing gynaecomastia: DISCO D igitalis I soniazid S pironolactone C imetidine O estrogen Mnemonic for causes of gynaecomastia: METOCLOPRAMIDE M etoclopramide E ctopic oestrogen T rauma skull/tumour breast, testes O rchitis C imetidine, Cushings L iver cirrhosis O besity P araplegia R A A cromegaly M ethyldopa I soniazid D igoxin E thionamide Carbimazole is not associated with gynaecomastia. Note the question asks for the least likely cause. Gynaecomastia Gynaecomastia describes an abnormal amount of breast tissue in males and is usually caused by an increased oestrogen:androgen ratio. It is important to differentiate the causes of galactorrhoea (due to the actions of prolactin on breast tissue) from those of gynaecomastia Causes of gynaecomastia physiological: normal in puberty syndromes with androgen deficiency: Kallman's, Klinefelter's testicular failure: e.g. Mumps liver disease testicular cancer e.g. Seminoma secreting HCG ectopic tumour secretion hyperthyroidism haemodialysis drugs: see below Drug causes of gynaecomastia spironolactone (most common drug cause) cimetidine digoxin cannabis finasteride oestrogens, anabolic steroids Very rare drug causes of gynaecomastia tricyclics isoniazid calcium channel blockers heroin busulfan methyldopa Treatment options identify and manage any overt underlying cause liposuction provides the best cosmetic outcome

Answer 92

The presence of chronic sinuses together with gram positive organisms and sulphur granules is highly suggestive of Actinomycosis. Crohns disease is associated with multiple fistulae, but not gram positive organisms with sulphur granules. Actinomycosis Chronic, progressive granulomatous disease caused by filamentous gram positive anaerobic bacteria from the Actinomycetaceae family. Actinomyces are commensal bacteria that become pathogenic when a mucosal barrier is breached. The disease most commonly occurs in the head and neck, although it may also occur in the abdominal cavity and in the thorax. The mass will often enlarge across tissue planes with the formation of multiple sinus tracts. Abdominopelvic actinomycosis occurs most frequently in individuals that have had appendicitis (65%) cases. Pathology On histological examination gram positive organisms and evidence of sulphur granules. Sulphur granules are colonies of organisms that appear as round or oval basophilic masses. They are also seen in other conditions such as nocardiosis. Treatment Long term antibiotic therapy usually with penicillin. Surgical resection is indicated for extensive necrotic tissue, non healing sinus tracts, abscesses or where biopsy is needed to exclude malignancy. References Wong V, Turmezei T and Weston V. Actinomycosis. BMJ 2011;343d6099.

Answer 93

The superior adrenal artery is a branch of the inferior phrenic artery. Adrenal gland anatomy Location Superomedially to the upper pole of each kidney Relationships of the right adrenal Diaphragm-Posteriorly, Kidney-Inferiorly, Vena Cava-Medially, Hepato-renal pouch and bare area of the liver-Anteriorly Relationships of the left adrenal Crus of the diaphragm-Postero- medially, Pancreas and splenic vessels-Inferiorly, Lesser sac and stomach-Anteriorly Arterial supply Superior adrenal arteries- from inferior phrenic artery, Middle adrenal arteries - from aorta, Inferior adrenal arteries -from renal arteries Venous drainage of the right adrenal Via one central vein directly into the IVC Venous drainage of the left adrenal Via one central vein into the left renal vein

Answer 94

Diaphragm disease, which is characterized by multiple thin, diaphragm-like strictures in the small intestine, is most commonly associated with: Oral non-steroidal anti-inflammatory drugs (NSAIDs) Explanation: • Oral NSAIDs are well-documented causes of diaphragm disease in the small intestine. NSAIDs can lead to mucosal injury, resulting in the formation of strictures and characteristic diaphragm-like lesions. • Alcohol abuse, abdominal radiotherapy, oral steroids, and chronic laxative misuse are not typically associated with diaphragm disease. Therefore, the correct answer is: Oral non-steroidal anti-inflammatory drugs

Answer 95

Glioblastomas typically display such marked appearances and an important differential on imaging is one of cerebral abscess. A meningioma would not display such infiltrative behavior. Significant necrosis is more commonly seen with glioblastomas than with other CNS tumours. CNS tumours 60% = Glioma and metastatic disease 20% = Meningioma 10% = Pituitary lesions In paediatric practice medulloblastomas (neuroectodermal tumours) were the commonest lesions, astrocytomas now account for the majority. Tumours arising in right temporal and frontal lobe may reach considerable size before becoming symptomatic. Whereas tumours in the speech and visual areas will typically produce early symptoms. Most paediatric CNS tumours are infratentorial Most adult CNS tumours are supratentorial Diagnosis MRI Scanning provides the best resolution. Treatment Usually surgery, even if tumour cannot be completely resected conditions such as rising ICP can be addressed with tumour debulking and survival and quality of life prolonged. Curative surgery can usually be undertaken with lesions such as meningiomas. Gliomas have a marked propensity to invade normal brain and resection of these lesions is nearly always incomplete.

Answer 96

The anion gap may be calculated by using (sodium + potassium) - (bicarbonate + chloride) = (142 + 4.0) - (104 + 19) = 23 mmol/L Anion gap The anion gap is calculated by: (sodium + potassium) - (bicarbonate + chloride) A normal anion gap is 8-14 mmol/L It is useful to consider in patients with a metabolic acidosis: Causes of a normal anion gap or hyperchloraemic metabolic acidosis gastrointestinal bicarbonate loss: diarrhoea, ureterosigmoidostomy, fistula renal tubular acidosis drugs: e.g. acetazolamide ammonium chloride injection Addison's disease Causes of a raised anion gap metabolic acidosis lactate: shock, hypoxia ketones: diabetic ketoacidosis, alcohol urate: renal failure acid poisoning: salicylates, methanol

Answer 97

A significant proportion of patients who take lithium treatment will develop a goitre and a number will become clinically hypothyroid. For this reason, monitoring of thyroid function tests is necessary during lithium therapy. Thyroid disease Patients may present with a number of different manifestations of thyroid disease. They can be broadly sub classified according to whether they are euthyroid or have clinical signs of thyroid dysfunction. In addition it needs to be established whether they have a mass or not. Assessment History Examination including USS If a nodule is identified then it should be sampled ideally via an image guided fine needle aspiration Radionucleotide scanning is of limited use Thyroid Tumours Papillary carcinoma Follicular carcinoma Anaplastic carcinoma Medullary carcinoma Lymphoma's Multinodular goitre One of the most common reasons for presentation Provided the patient is euthyroid and asymptomatic and no discrete nodules are seen, they can be reassured. In those with compressive symptoms surgery is required and the best operation is a total thyroidectomy. Sub total resections were practised in the past and simply result in recurrent disease that requires a difficult revisional resection. Endocrine dysfunction In general these patients are managed by physicians initially. Surgery may be offered alongside radio iodine for patients with Graves disease that fails with medical management or in patients who would prefer not to be irradiated (e.g. pregnant women). Patients with hypothyroidism do not generally get offered a thyroidectomy. Sometimes people inadvertently get offered resections during the early phase of Hashimotos thyroiditis, however, with time the toxic phase passes and patients can simply be managed with thyroxine. Complications following surgery Anatomical such as recurrent laryngeal nerve damage. Bleeding. Owing to the confined space haematoma's may rapidly lead to respiratory compromise owing to laryngeal oedema. Damage to the parathyroid glands resulting in hypocalcaemia. Further sources of information 1. http://www.acb.org.uk/docs/TFTguidelinefinal.pdf- Association of Clinical Biochemistry guidelines for thyroid function tests. 2. British association of endocrine surgeons website- http://www.baets.org.uk

Answer 98

With the exception of subscapularis which inserts into the lesser tuberosity, the muscles of the rotator cuff insert into the greater tuberosity. Shoulder joint Shallow synovial ball and socket type of joint. It is an inherently unstable joint, but is capable to a wide range of movement. Stability is provided by muscles of the rotator cuff that pass from the scapula to insert in the greater tuberosity (all except sub scapularis-lesser tuberosity). Glenoid labrum Fibrocartilaginous rim attached to the free edge of the glenoid cavity Tendon of the long head of biceps arises from within the joint from the supraglenoid tubercle, and is fused at this point to the labrum. The long head of triceps attaches to the infraglenoid tubercle Fibrous capsule Attaches to the scapula external to the glenoid labrum and to the labrum itself (postero-superiorly) Attaches to the humerus at the level of the anatomical neck superiorly and the surgical neck inferiorly Anteriorly the capsule is in contact with the tendon of subscapularis, superiorly with the supraspinatus tendon, and posteriorly with the tendons of infraspinatus and teres minor. All these blend with the capsule towards their insertion. Two defects in the fibrous capsule; superiorly for the tendon of biceps. Anteriorly there is a defect beneath the subscapularis tendon. The inferior extension of the capsule is closely related to the axillary nerve at the surgical neck and this nerve is at risk in anteroinferior dislocations. It also means that proximally sited osteomyelitis may progress to septic arthritis. Movements and muscles Flexion Anterior part of deltoid Pectoralis major Biceps Coracobrachialis Extension Posterior deltoid Teres major Latissimus dorsi Adduction Pectoralis major Latissimus dorsi Teres major Coracobrachialis Abduction Mid deltoid Supraspinatus Medial rotation Subscapularis Anterior deltoid Teres major Latissimus dorsi Lateral rotation Posterior deltoid Infraspinatus Teres minor Important anatomical relations Anteriorly Brachial plexus Axillary artery and vein Posterior Suprascapular nerve Suprascapular vessels Inferior Axillary nerve Circumflex humeral vessels

Answer 99

Sturge - Weber syndrome is a an arteriovenous malformation affecting the face and CNS, the peripheral vessels are not affected. Simple varicose veins should not typically be associated with port wine staining, nor should a DVT or angiosarcoma. Klippel-Trenaunay syndrome Klippel-Trenaunay-Weber syndrome generally affects a single extremity, although cases of multiple affected limbs have been reported. The leg is the most common site followed by the arms, the trunk, and rarely the head and the neck Signs and symptoms The birth defect is diagnosed by the presence of a combination of these symptoms: One or more distinctive port-wine stains with sharp borders Varicose veins Hypertrophy of bony and soft tissues, that may lead to local gigantism or shrinking. An improperly developed lymphatic system In some cases, port-wine stains (capillary port wine type) may be absent. Such cases are very rare and may be classified as 'atypical Klippel-Trenaunay syndrome'. KTS can either affect blood vessels, lymph vessels, or both. The condition most commonly presents with a mixture of the two. Those with venous involvement experience increased pain and complications.

Answer 100

Macrolides act by inhibiting bacterial protein synthesis. If pushed to give an answer they are bacteriostatic in nature, but in reality this depends on the dose and type of organism being treated. Erythromycin was the first macrolide used clinically. Newer examples include clarithromycin and azithromycin. Adverse effects of erythromycin gastrointestinal side-effects are common cholestatic jaundice: risk may be reduced if erythromycin stearate is used P450 inhibitor Antibiotics: mechanism of action The lists below summarise the site of action of the commonly used antibiotics Inhibit cell wall formation penicillins cephalosporins Inhibit protein synthesis aminoglycosides (cause misreading of mRNA) chloramphenicol macrolides (e.g. erythromycin) tetracyclines fusidic acid Inhibit DNA synthesis quinolones (e.g. ciprofloxacin) metronidazole sulphonamides trimethoprim Inhibit RNA synthesis rifampicin

Answer 101

In statistics, the 68-95-99.7 rule or three-sigma rule, or empirical rule states that for a normal distribution, nearly all values lie within 3 standard deviations of the mean. About 68.27% of the values lie within 1 standard deviation of the mean. Similarly, about 95.45% of the values lie within 2 standard deviations of the mean. Nearly all (99.73%) of the values lie within 3 standard deviations of the mean 95.4% of values lie within 2 SD of the mean.

Answer 102

The spongy urethra is around 15cm long and is the longest part of the male urethra. Urethral anatomy Female urethra The female urethra is shorter and more acutely angulated than the male urethra. It is an extra-peritoneal structure and embedded in the endopelvic fascia. The neck of the bladder is subjected to transmitted intra-abdominal pressure and therefore deficiency in this area may result in stress urinary incontinence. Between the layers of the urogenital diaphragm the female urethra is surrounded by the external urethral sphincter, this is innervated by the pudendal nerve. It ultimately lies anterior to the vaginal orifice. Male urethra In males the urethra is much longer and is divided into four parts. Pre-prostatic urethra Extremely short and lies between the bladder and prostate gland.It has a stellate lumen and is between 1 and 1.5cm long.Innervated by sympathetic noradrenergic fibres, as this region is composed of striated muscles bundles they may contract and prevent retrograde ejaculation. Prostatic urethra This segment is wider than the membranous urethra and contains several openings for the transmission of semen (at the midpoint of the urethral crest). Membranous urethra Narrowest part of the urethra and surrounded by external sphincter. It traverses the perineal membrane 2.5cm postero-inferior to the symphysis pubis. Penile urethra Travels through the corpus spongiosum on the underside of the penis. It is the longest urethral segment.It is dilated at its origin as the infrabulbar fossa and again in the glans penis as the navicular fossa. The bulbo-urethral glands open into the spongiose section of the urethra 2.5cm below the perineal membrane. The urothelium is transitional in nature near to the bladder and becomes squamous more distally.

Answer 103

Ferritin can be markedly increased during acute illness. The other parameters tend to decrease during an acute phase response. Acute phase proteins Acute phase proteins CRP procalcitonin ferritin fibrinogen alpha-1 antitrypsin caeruloplasmin serum amyloid A haptoglobin complement During the acute phase response the liver decreases the production of other proteins (sometimes referred to as negative acute phase proteins). Examples include: albumin transthyretin (formerly known as prealbumin) transferrin retinol binding protein cortisol binding protein Levels of CRP are commonly measured in acutely unwell patients. CRP is a protein synthesised in the liver and binds to phosphocholine in bacterial cells and on those cells undergoing apoptosis. In binding to these cells it is then able to activate the complement system. CRP levels are known to rise in patients following surgery. However, levels of greater than 150 at 48 hours post operatively are suggestive of evolving complications.

Answer 104

This patient has neuropathic pain. Amitryptyline is the treatment of choice. Carbamazepine is mainly used for trigeminal neuralgia. Neuropathic pain Neuropathic pain may be defined as pain which arises following damage or disruption of the nervous system. It is often difficult to treat and responds poorly to standard analgesia. Examples include: diabetic neuropathy post-herpetic neuralgia trigeminal neuralgia prolapsed intervertebral disc NICE issued guidance in 2010 on the management of neuropathic pain: first-line treatment*: oral amitriptyline or pregabalin if satisfactory pain reduction is obtained with amitriptyline but the person cannot tolerate the adverse effects, consider oral imipramine or nortriptyline as an alternative second-line treatment: if first-line treatment was with amitriptyline, switch to or combine with pregabalin. If first-line treatment was with pregabalin, switch to or combine with amitriptyline other options: pain management clinic, tramadol (not other strong opioids), topical lidocaine for localised pain if patients unable to take oral medication *please note that for some specific conditions the guidance may vary. For example carbamazepine is used first-line for trigeminal neuralgia, duloxetine for diabetic neuropathy

Answer 105

The injury described—initial inability to extend the wrist following a road traffic accident, which then improves over the following weeks—is most consistent with a radial nerve neuropraxia. Neuropraxia is a type of nerve injury characterized by a temporary loss of motor and sensory function due to blockage of nerve conduction. This is often caused by compression or blunt trauma, and typically, there is no physical damage to the nerve itself. Recovery is usually complete and occurs within days to weeks. Here’s why the other options are less likely: • Radial nerve neurotmesis: This is a more severe form of nerve injury where the nerve is completely severed. Recovery typically requires surgical intervention and takes much longer, with less chance of full recovery. • Axillary nerve axonotmesis: This involves damage to the axillary nerve and the nerve fibers (axons), but the surrounding connective tissue remains intact. It would not typically result in wrist drop, as the axillary nerve primarily innervates the deltoid muscle and the teres minor muscle. • Ulnar nerve neuropraxia: This would affect the ulnar nerve, which primarily controls muscles in the forearm and hand. It would not cause wrist drop, which is specifically related to the radial nerve. • Ulnar nerve axonotmesis: Similar to the above, this involves damage to the ulnar nerve and would not result in wrist drop. Therefore, the most likely injury is radial nerve neuropraxia. Neuropraxia Nerve intact but electrical conduction is affected Myelin sheath integrity is preserved Full recovery Autonomic function preserved Wallerian degeneration does not occur

Answer 106

The appropriate initial dose of calories to be administered via total parenteral nutrition (TPN) for a severely unwell, malnourished 50-year-old male weighing 70 kg would be: 2000 Kcal This recommendation aligns with standard clinical practice for initial TPN administration, where the caloric intake typically ranges from 25 to 35 kcal/kg/day, starting at the lower end for critically ill or malnourished patients and gradually increasing as tolerated. Explanation: TPN is used to provide nutrition intravenously when enteral feeding is not possible. The initial caloric needs are calculated based on the patient’s weight and clinical condition. For a 70 kg male: • Minimum requirement: 70 \text{ kg} \times 25 \text{ kcal/kg/day} = 1750 \text{ kcal/day} • Optimal requirement: 70 \text{ kg} \times 30 \text{ kcal/kg/day} = 2100 \text{ kcal/day} Thus, starting at 2000 kcal/day is a reasonable and appropriate initial dose. As this person is severely ill and malnourished, the initial calories administered is reduced by 50% in the first few days. Given that the initial caloric intake should be reduced by 50% in the first few days for a patient starting on total parenteral nutrition (TPN), the most appropriate initial dose of calories for this patient would be: 1000 Kcal Explanation: If we consider that the optimal caloric requirement for a 70 kg male is approximately 2000 kcal/day (as calculated previously), then reducing this by 50% for the initial period would result in an initial dose of: 2000 \text{ kcal/day} \times 0.5 = 1000 \text{ kcal/day} Therefore, 1000 kcal/day is a safer starting dose to prevent complications such as refeeding syndrome. However, since 1000 kcal/day was not one of the options provided, the closest and most appropriate option would be: 700 Kcal This represents a conservative approach to initiate TPN and gradually increase the caloric intake as the patient stabilizes. Nutrition prescriptions National institute of clinical excellence (NICE) guidelines For people not severely ill and not at risk of refeeding syndrome aim to give 25-35 kcal/kg/day (lower if BMI > 25) 0.8-1.5g protein /kg/day 30-35 ml fluid/kg/day Adequate electrolytes, minerals, vitamins Severely ill patients aim to give < 50% of the energy and protein levels over the first 24-48h. For people at high risk of refeeding syndrome: Start at up to 10 kcal/kg/day increasing to full needs over 4-7 days Start immediately before and during feeding: oral thiamine 200-300mg/day, vitamin B co strong 1 tds and supplements Give K+ (2-4 mmol/kg/day), phosphate (0.3-0.6 mmol/kg/day), magnesium (0.2-0.4 mmol/kg/day)

Answer 107

These histological features are typically seen in TB. Necrosis occurring in granulomas is usually indicative of an underlying infective cause. Churg Strauss syndrome is a form of vasculitis, which is the usual histological finding. Granulomas are reported in the condition, but it is rare for them to demonstrate necrosis. Tuberculosis pathology Is a form of primary chronic inflammation, caused by the inability of macrophages to kill the Mycobacterium tuberculosis. The macrophages often migrate to regional lymph nodes, the lung lesion plus affected lymph nodes is referred to as a Ghon complex. This leads to the formation of a granuloma which is a collection of epithelioid histiocytes. There is the presence of caseous necrosis in the centre. The inflammatory response is mediated by a type 4 hypersensitivity reaction. In healthy individuals the disease may be contained, in the immunocompromised disseminated (miliary TB) may occur. Diagnosis Waxy membrane of mycobacteria prevents binding with normal stains. Ziehl - Neelsen staining is typically used. Culture based methods take far longer. Image showing acid- alcohol fast mycobacteria stained using the Ziehl- Neelsen method

Answer 108

This will demonstrate any overt splenic injury. A CT scan carries a significant dose of radiation. In the absence of haemodynamic instability or other major associated injuries the use of USS to exclude intraabdominal free fluid (blood) would seem safe when coupled with active observation. An USS will also show splenic haematomas. Splenic trauma - The spleen is one of the more commonly injured intra abdominal organs In most cases the spleen can be conserved. The management is dictated by the associated injuries, haemodynamic status and extent of direct splenic injury. Management of splenic trauma Conservative Small subcapsular haematoma Minimal intra abdominal blood No hilar disruption Laparotomy with conservation Increased amounts of intraabdominal blood Moderate haemodynamic compromise Tears or lacerations affecting <50% Resection Hilar injuries Major haemorrhage Major associated injuries Splenectomy Technique Trauma GA Long midline incision If time permits insert a self retaining retractor (e.g. Balfour/ omnitract) Large amount of free blood is usually present. Pack all 4 quadrants of the abdomen. Allow the anaesthetist to 'catch up' Remove the packs and assess the viability of the spleen. Hilar injuries and extensive parenchymal lacerations will usually require splenectomy. Divide the short gastric vessels and ligate them. Clamp the splenic artery and vein. Two clamps on the patient side are better and allow for double ligation and serve as a safety net if your assistant does not release the clamp smoothly. Be careful not to damage the tail of the pancreas, if you do then this will need to be formally removed and the pancreatic duct closed. Wash out the abdomen and place a tube drain to the splenic bed. Some surgeons implant a portion of spleen into the omentum, whether you decide to do this is a matter of personal choice. Post operatively the patient will require prophylactic penicillin V and pneumococcal vaccine. Elective Elective splenectomy is a very different operation from that performed in the emergency setting. The spleen is often large (sometimes massive). Most cases can be performed laparoscopically. The spleen will often be macerated inside a specimen bag to facilitate extraction. Complications Haemorrhage (may be early and either from short gastrics or splenic hilar vessels Pancreatic fistula (from iatrogenic damage to pancreatic tail) Thrombocytosis: prophylactic aspirin Encapsulated bacteria infection e.g. Strep. pneumoniae, Haemophilus influenzae and Neisseria meningitidis

Answer 109

The phrenic nerve lies anteriorly at the root of the right lung. Lung anatomy The right lung is composed of 3 lobes divided by the oblique and transverse fissures. The left lung has two lobes divided by the oblique fissure.The apex of both lungs is approximately 4cm superior to the sterno-costal joint of the first rib. Immediately below this is a sulcus created by the subclavian artery. Peripheral contact points of the lung Base: diaphragm Costal surface: corresponds to the cavity of the chest Mediastinal surface: Contacts the mediastinal pleura. Has the cardiac impression. Above and behind this concavity is a triangular depression named the hilum, where the structures which form the root of the lung enter and leave the viscus. These structures are invested by pleura, which, below the hilum and behind the pericardial impression, forms the pulmonary ligament Right lung Above the hilum is the azygos vein; Superior to this is the groove for the superior vena cava and right innominate vein; behind this, and nearer the apex, is a furrow for the innominate artery. Behind the hilum and the attachment of the pulmonary ligament is a vertical groove for the oesophagus; In front and to the right of the lower part of the oesophageal groove is a deep concavity for the extrapericardiac portion of the inferior vena cava. The root of the right lung lies behind the superior vena cava and the right atrium, and below the azygos vein. The right main bronchus is shorter, wider and more vertical than the left main bronchus and therefore the route taken by most foreign bodies. Left lung Above the hilum is the furrow produced by the aortic arch, and then superiorly the groove accommodating the left subclavian artery; Behind the hilum and pulmonary ligament is a vertical groove produced by the descending aorta, and in front of this, near the base of the lung, is the lower part of the oesophagus. The root of the left lung passes under the aortic arch and in front of the descending aorta. Inferior borders of both lungs 6th rib in mid clavicular line 8th rib in mid axillary line 10th rib posteriorly The pleura runs two ribs lower than the corresponding lung level. Bronchopulmonary segments Segment number Right lung Left lung 1 Apical Apical 2 Posterior Posterior 3 Anterior Anterior 4 Lateral Superior lingular 5 Medial Inferior lingular 6 Superior (apical) Superior (apical) 7 Medial basal Medial basal 8 Anterior basal Anterior basal 9 Lateral basal Lateral basal 10 Posterior basal Posterior basal

Answer 110

The entire female urethra drains to the internal iliac nodes. Urethral anatomy Female urethra The female urethra is shorter and more acutely angulated than the male urethra. It is an extra-peritoneal structure and embedded in the endopelvic fascia. The neck of the bladder is subjected to transmitted intra-abdominal pressure and therefore deficiency in this area may result in stress urinary incontinence. Between the layers of the urogenital diaphragm the female urethra is surrounded by the external urethral sphincter, this is innervated by the pudendal nerve. It ultimately lies anterior to the vaginal orifice. Male urethra In males the urethra is much longer and is divided into four parts. Pre-prostatic urethra Extremely short and lies between the bladder and prostate gland.It has a stellate lumen and is between 1 and 1.5cm long.Innervated by sympathetic noradrenergic fibres, as this region is composed of striated muscles bundles they may contract and prevent retrograde ejaculation. Prostatic urethra This segment is wider than the membranous urethra and contains several openings for the transmission of semen (at the midpoint of the urethral crest). Membranous urethra Narrowest part of the urethra and surrounded by external sphincter. It traverses the perineal membrane 2.5cm postero-inferior to the symphysis pubis. Penile urethra Travels through the corpus spongiosum on the underside of the penis. It is the longest urethral segment.It is dilated at its origin as the infrabulbar fossa and again in the glans penis as the navicular fossa. The bulbo-urethral glands open into the spongiose section of the urethra 2.5cm below the perineal membrane. The urothelium is transitional in nature near to the bladder and becomes squamous more distally.

Answer 111

The false statement regarding omphalocele is: The herniated organs lie outside the peritoneal sac. Explanation: Omphalocele is a congenital defect in the abdominal wall where the intestines, liver, and occasionally other organs remain outside the abdomen in a sac because of a failure of the intestines to return to the abdominal cavity during fetal development. The sac is covered by a membrane consisting of peritoneum and amnion. 1. The herniated organs lie outside the peritoneal sac: This is false. In omphalocele, the herniated organs are contained within a protective sac formed by the peritoneum and amnion. 2. Cardiac abnormalities co-exist in 25%: This is true. Omphalocele is often associated with other congenital anomalies, including cardiac defects. 3. The caecum is usually right sided: This is true. The caecum and other abdominal organs are typically in their normal positions within the sac. 4. The defect occurs through the umbilicus: This is true. Omphalocele occurs through the umbilical ring. 5. Mortality may be as high as 15%: This is true. Mortality rates can be high, especially if there are associated congenital anomalies and complications. Therefore, the correct answer is that the statement “The herniated organs lie outside the peritoneal sac” is false. Gastroschisis: Isolated abnormality, bowel lies outside abdominal wall through defect located to right of umbilicus. Exomphalos: Liver and gut remain covered with membranous sac connected to umbilical cord. It is associated with other developmental defects. They are contained within the peritoneal sac and therefore do not have the fluid losses seen in gastroschisis. True malrotation is unusual and minor variants may not result in a requirement for surgery. Paediatric Gastrointestinal disorders Pyloric stenosis M>F 5-10% Family history in parents Projectile non bile stained vomiting at 4-6 weeks of life Diagnosis is made by test feed or USS Treatment: Ramstedt pyloromyotomy (open or laparoscopic) Acute appendicitis Uncommon under 3 years When occurs may present atypically Mesenteric adenitis Central abdominal pain and URTI Conservative management Intussusception Telescoping bowel Proximal to or at the level of, ileocaecal valve 6-9 months age Colicky pain, diarrhoea and vomiting, sausage shaped mass, red jelly stool. Treatment: reduction with air insufflation Malrotation High caecum at the midline Feature in exomphalos, congenital diaphragmatic hernia, intrinsic duodenal atresia May be complicated by development of volvulus, infant with volvulus may have bile stained vomiting Diagnosis is made by upper GI contrast study and USS Treatment is by laparotomy, if volvulus is present (or at high risk of occurring then a ladds procedure is performed Hirschsprung's disease Absence of ganglion cells from myenteric and submucosal plexuses Occurs in 1/5000 births Full thickness rectal biopsy for diagnosis Delayed passage of meconium and abdominal distension Treatment is with rectal washouts initially, thereafter an anorectal pull through procedure Oesophageal atresia Associated with tracheo-oesophageal fistula and polyhydramnios May present with choking and cyanotic spells following aspiration VACTERL associations Meconium ileus Usually delayed passage of meconium and abdominal distension Majority have cystic fibrosis X-Rays may not show a fluid level as the meconium is viscid (depends upon feeding), PR contrast studies may dislodge meconium plugs and be therapeutic Infants who do not respond to PR contrast and NG N-acetyl cysteine will require surgery to remove the plugs Biliary atresia Jaundice > 14 days Increased conjugated bilirubin Urgent Kasai procedure Necrotising enterocolitis Prematurity is the main risk factor Early features include abdominal distension and passage of bloody stools X-Rays may show pneumatosis intestinalis and evidence of free air Increased risk when empirical antibiotics are given to infants beyond 5 days Treatment is with total gut rest and TPN, babies with perforations will require laparotomy

Answer 112

The presence of a cardiac tamponade is suggested by Becks Triad: Hypotension Muffled heart sounds Raised JVP Thoracic trauma Key points related to thoracic trauma Less than 10% of blunt chest trauma and 15-30% of penetrating chest trauma requires operative intervention. The physiologic consequences of thoracic trauma are hypoxia, hypercarbia, and acidosis. Contusion, hematoma, and alveolar collapse, or changes in intrathoracic pressure relationships (e.g., tension pneumothorax and open pneumothorax) cause hypoxia and lead to metabolic acidosis. Hypercarbia causes respiratory acidosis and most often follows inadequate ventilation caused by changes in intrathoracic pressure relationships and depressed level of consciousness. Types of thoracic trauma Tension pneumothorax Often laceration to lung parenchyma with flap Pressure develops in thorax Most common cause is mechanical ventilation in patient with pleural injury Symptoms overlap with cardiac tamponade, hyper-resonant percussion note is more likely in tension pnemothorax Flail chest Chest wall disconnects from thoracic cage Multiple rib fractures (at least two fractures per rib in at least two ribs) Associated with pulmonary contusion Abnormal chest motion Avoid over hydration and fluid overload Pneumothorax Most common cause is lung laceration with air leakage Most traumatic pneumothoraces should have a chest drain Patients with traumatic pneumothorax should never be mechanically ventilated until a chest drain is inserted Haemothorax Most commonly due to laceration of lung, intercostal vessel or internal mammary artery Haemothoraces large enough to appear on CXR are treated with large bore chest drain Surgical exploration is warranted if >1500ml blood drained immediately Cardiac tamponade Beck's triad: elevated venous pressure, reduced arterial pressure, reduced heart sounds Pulsus paradoxus May occur with as little as 100ml blood Pulmonary contusion Most common potentially lethal chest injury Arterial blood gases and pulse oximetry important Early intubation within an hour if significant hypoxia Blunt cardiac injury Usually occurs secondary to chest wall injury ECG may show features of myocardial infarction Sequelae: hypotension, arrhythmias, cardiac wall motion abnormalities Aorta disruption Deceleration injuries Contained haematoma Widened mediastinum Diaphragm disruption Most due to motor vehicle accidents and blunt trauma causing large radial tears (laceration injuries result in small tears) More common on left side Insert gastric tube, may pass into intrathoracic stomach Mediastinal traversing wounds Entrance wound in one hemithorax and exit wound/foreign body in opposite hemithorax Mediastinal haematoma or pleural cap suggests great vessel injury Mortality is 20%

Answer 113

Villous adenomas carry the highest risk of malignant transformation. Hyperplastic polyps carry little in the way of increased risk. Although, patients with hamartomatous polyp syndromes may have a high risk of malignancy, the polyps themselves have little malignant potential. Colonic polyps Colonic Polyps May occur in isolation, or greater numbers as part of the polyposis syndromes. In FAP greater than 100 polyps are typically present. The risk of malignancy in association with adenomas is related to size, and is the order of 10% in a 1cm adenoma. Isolated adenomas seldom give risk of symptoms (unless large and distal). Distally sited villous lesions may produce mucous and if very large, electrolyte disturbances may occur. Follow up of colonic polyps Group Action Colorectal cancer Colonoscopy 1 year post resection Large non pedunculated colorectal polyps (LNPCP), R0 resection One off scope at 3 years Large non pedunculated colorectal polyps (LNPCP) R1 or non en bloc resection Site check at 2-6 months and then a further scope at 12 months High risk findings at baseline colonoscopy One off surveillance at 3 years No high risk findings at baseline colonoscopy No colonoscopic surveillance and invite participation in NHSBCSP programme when due High risk findings More than 2 premalignant polyps including 1 or more advanced colorectal polyps OR More than 5 pre malignant polyps Exceptions to guidelines If patient more than 10 years younger than lower screening age and has polyps but no high risk findings, consider colonoscopy at 5 or 10 years. Segmental resection or complete colectomy should be considered when: 1. Incomplete excision of malignant polyp 2. Malignant sessile polyp 3. Malignant pedunculated polyp with submucosal invasion 4. Polyps with poorly differentiated carcinoma 5. Familial polyposis coli -Screening from teenager up to 40 years by 2 yearly sigmoidoscopy/colonoscopy -Panproctocolectomy and Ileostomy or Restorative Panproctocolectomy. Rectal polypoidal lesions may be amenable to trans anal endoscopic microsurgery.

Answer 114

The testicular artery is a branch of the abdominal aorta. Scrotal and testicular anatomy Spermatic cord Formed by the vas deferens and is covered by the following structures: Layer Origin Internal spermatic fascia Transversalis fascia Cremasteric fascia From the fascial coverings of internal oblique External spermatic fascia External oblique aponeurosis Contents of the cord Vas deferens Transmits sperm and accessory gland secretions Testicular artery Branch of abdominal aorta supplies testis and epididymis Artery of vas deferens Arises from inferior vesical artery Cremasteric artery Arises from inferior epigastric artery Pampiniform plexus Venous plexus, drains into right or left testicular vein Sympathetic nerve fibres Lie on arteries, the parasympathetic fibres lie on the vas Genital branch of the genitofemoral nerve Supplies cremaster Lymphatic vessels Drain to lumbar and para-aortic nodes Scrotum Composed of skin and closely attached dartos fascia. Arterial supply from the anterior and posterior scrotal arteries Lymphatic drainage to the inguinal lymph nodes Parietal layer of the tunica vaginalis is the innermost layer Testes The testes are surrounded by the tunica vaginalis (closed peritoneal sac). The parietal layer of the tunica vaginalis adjacent to the internal spermatic fascia. The testicular arteries arise from the aorta immediately inferiorly to the renal arteries. The pampiniform plexus drains into the testicular veins, the left drains into the left renal vein and the right into the inferior vena cava. Lymphatic drainage is to the para-aortic nodes.

Answer 115

Heberdens nodes may produce swelling of the distal interphalangeal joint with deviation of the finger tip. Hand diseases Dupuytrens contracture Fixed flexion contracture of the hand where the fingers bend towards the palm and cannot be fully extended. Caused by underlying contractures of the palmar aponeurosis . The ring finger and little finger are the fingers most commonly affected. The middle finger may be affected in advanced cases, but the index finger and the thumb are nearly always spared. Progresses slowly and is usually painless. In patients with this condition, the tissues under the skin on the palm of the hand thicken and shorten so that the tendons connected to the fingers cannot move freely. The palmar aponeurosis becomes hyperplastic and undergoes contracture. Commonest in males over 40 years of age. Association with liver cirrhosis and alcoholism. However, many cases are idiopathic. Treatment is surgical and involves fasciectomy. However, the condition may recur and many surgical therapies are associated with risk of neurovascular damage to the digital nerves and arteries. Carpal tunnel syndrome Idiopathic median neuropathy at the carpal tunnel. Characterised by altered sensation of the lateral 3 fingers. The condition is commoner in females and is associated with other connective tissue disorders such as rheumatoid disease. It may also occur following trauma to the distal radius. Symptoms occur mainly at night in early stages of the condition. Examination may demonstrate wasting of the muscles of the thenar eminence and symptoms may be reproduced by Tinels test (compression of the contents of the carpal tunnel). Formal diagnosis is usually made by electrophysiological studies. Treatment is by surgical decompression of the carpal tunnel, a procedure achieved by division of the flexor retinaculum. Non - surgical options include splinting and bracing. Miscellaneous hand lumps Osler's nodes Osler's nodes are painful, red, raised lesions found on the hands and feet. They are the result of the deposition of immune complexes. Bouchard's nodes Hard, bony outgrowths or gelatinous cysts on the proximal interphalangeal joints (the middle joints of fingers or toes.) They are a sign of osteoarthritis, and are caused by formation of calcific spurs of the articular cartilage. Heberden's nodes Typically develop in middle age, beginning either with a chronic swelling of the affected joints or the sudden painful onset of redness, numbness, and loss of manual dexterity. This initial inflammation and pain eventually subsides, and the patient is left with a permanent bony outgrowth that often skews the fingertip sideways. It typically affects the DIP joint. Ganglion Swelling in association with a tendon sheath commonly near a joint. They are common lesions in the wrist and hand. Usually they are asymptomatic and cause little in the way of functional compromise. They are fluid filled although the fluid is similar to synovial fluid it is slightly more viscous. When the cysts are troublesome they may be excised.

Answer 116

Lignocaine blocks sodium channels. They will typically be activated first, hence the pain some patients experience on administration. Local anaesthetic agents Lidocaine An amide Local anaesthetic and a less commonly used antiarrhythmic (affects Na channels in the axon) Hepatic metabolism, protein bound, renally excreted Toxicity: due to IV or excess administration. Increased risk if liver dysfunction or low protein states. Note acidosis causes lidocaine to detach from protein binding. Drug interactions: Beta blockers, ciprofloxacin, phenytoin Features of toxicity: Initial CNS over activity then depression as lidocaine initially blocks inhibitory pathways then blocks both inhibitory and activating pathways. Cardiac arrhythmias. Increased doses may be used when combined with adrenaline to limit systemic absorption. Cocaine Pure cocaine is a salt, usually cocaine hydrochloride. It is supplied for local anaesthetic purposes as a paste. It is supplied for clinical use in concentrations of 4 and 10%. It may be applied topically to the nasal mucosa. It has a rapid onset of action and has the additional advantage of causing marked vasoconstriction. It is lipophillic and will readily cross the blood brain barrier. Its systemic effects also include cardiac arrhythmias and tachycardia. Apart from its limited use in ENT surgery it is otherwise used rarely in mainstream surgical practice. Bupivacaine Bupivacaine binds to the intracellular portion of sodium channels and blocks sodium influx into nerve cells, which prevents depolarization. It has a much longer duration of action than lignocaine and this is of use in that it may be used for topical wound infiltration at the conclusion of surgical procedures with long duration analgesic effect. It is cardiotoxic and is therefore contra indicated in regional blockage in case the tourniquet fails. Levobupivacaine (Chirocaine) is less cardiotoxic and causes less vasodilation. Prilocaine Similar mechanism of action to other local anaesthetic agents. However, it is far less cardiotoxic and is therefore the agent of choice for intravenous regional anaesthesia e.g. Biers Block. All local anaesthetic agents dissociate in tissues and this contributes to their therapeutic effect. The dissociation constant shifts in tissues that are acidic e.g. where an abscess is present, and this reduces the efficacy. Doses of local anaesthetics Agent Dose plain Dose with adrenaline Lignocaine 3mg/Kg 7mg/Kg Bupivacaine 2mg/Kg 2mg/Kg Prilocaine 6mg/Kg 9mg/Kg These are a guide only as actual doses depend on site of administration, tissue vascularity and co-morbidities. Maximum total local anaesthetic doses Lignocaine 1% plain - 3mg/ Kg - 200mg (20ml) Lignocaine 1% with 1 in 200,000 adrenaline - 7mg/Kg - 500mg (50ml) Bupivacaine 0.5% - 2mg/kg- 150mg (30ml) Maximum doses are based on ideal body weight Effects of adrenaline Adrenaline may be added to local anaesthetic drugs. It prolongs the duration of action at the site of injection and permits usage of higher doses (see above). It is contra indicated in patients taking MAOI's or tricyclic antidepressants. The toxicity of bupivacaine is related to protein binding and addition of adrenaline to this drug does not permit increases in the total dose of bupivacaine, in contrast to the situation with lignocaine.

Answer 117

The Bolam test defines if a decision made by a doctor is in agreement with the professional standard of medical practise. Consent There are 3 types of consent: 1. Informed 2. Expressed 3. Implied Consent forms used in UK NHS Consent Form 1 For competent adults who are able to consent for themselves where consciousness may be impaired (e.g. GA) Consent Form 2 For an adult consenting on behalf of a child where consciousness is impaired Consent Form 3 For an adult or child where consciousness is not impaired Consent Form 4 For adults who lack capacity to provide informed consent Capacity Key points include: 1. Understand and retain information 2. Patient believes the information to be true 3. Patient is able to weigh the information to make a decision All patients must be assumed to have capacity Consent in minors Young children and older children who are not Gillick competent cannot consent for themselves. In British law the patients biological mother can always provide consent. The child's father can consent if the parents are married (and the father is the biological father), or if the father is named on the birth certificate (irrespective of marital status). If parents are not married and the father is not named on the birth certificate then the father cannot consent.

Answer 118

Musculocutaneous nerve compression due to entrapment of the nerve between biceps and brachialis. Elbow flexion and supination of the arm are affected. This is a rare isolated injury. Musculocutaneous nerve Branch of lateral cord of brachial plexus Path It penetrates the coracobrachialis muscle Passes obliquely between the biceps brachii and the brachialis to the lateral side of the arm Above the elbow it pierces the deep fascia lateral to the tendon of the biceps brachii Continues into the forearm as the lateral cutaneous nerve of the forearm Innervates Coracobrachialis Biceps brachii Brachialis

Answer 119

This man needs urgent decompression and extradural haematoma is the most likely event, from a lacerated middle meningeal artery. Most neurosurgeons would perform a craniotomy. However, rural units and those units without neurosurgical kit facing this emergency may resort to Burr Holes. Head injury management- NICE Guidelines Summary of guidelines All patients should be assessed within 15 minutes on arrival to A&E Document all 3 components of the GCS If GCS <8 or = to 8, consider stabilising the airway Full spine immobilisation until assessment if: - GCS < 15 - neck pain/tenderness - paraesthesia extremities - focal neurological deficit - suspected c-spine injury If a c-spine injury is suspected a 3 view c-spine x-ray is indicated. CT c-spine is preferred if: - Intubated - GCS <13 - Normal x-ray but continued concerns regarding c-spine injury - Any focal neurology - A CT head scan is being performed - Initial plain films are abnormal Immediate CT head (within 1 hour) if: GCS < 12 on admission GCS < 15 2 hours after admission Suspected open or depressed skull fracture Suspected skull base fracture (panda eyes, Battle's sign, CSF from nose/ear, bleeding ear) Focal neurology Vomiting > 1 episode Post traumatic seizure Contact neurosurgeon if: Persistent GCS < 8 or = 8 Unexplained confusion > 4h Reduced GCS after admission Progressive neurological signs Incomplete recovery post seizure Penetrating injury Cerebrospinal fluid leak Observations 1/2 hourly GCS until 15 In the latest guidance, there is a move to considering CT in those on anticoagulants rather than mandating it.

Answer 120

Case series that are non randomised and lack concurrent controls at best supply level IV evidence only. To qualify for level I and II evidence a prospective randomised controlled trial with appropriate blinding, control matching and power calculations is needed. Levels of evidence The level of evidence refers to the study design used by investigators to minimise bias. Level of evidence Source I Evidence obtained from systematic review of all relevant randomised controlled trials II Evidence derived from at least one properly designed randomised controlled trial III Evidence derived from well designed pseudo-randomised controlled trials (e.g. alternate allocation) or historical controls IV Evidence derived from case series or case reports V Panel or expert opinion Many of the categories contain sub groups, detailed knowledge of these are not required for MRCS Part A.

Answer 121

The most appropriate course of action for a 30-year-old man with an open tibial fracture (20 cm wound, extensive periosteal stripping, neurovascularly intact) who has already received IV antibiotics and dressing is: Immediate skeletal stabilisation and application of negative pressure dressing. Explanation: This scenario describes a Gustilo-Anderson grade IIIB open fracture, characterized by extensive soft tissue damage and periosteal stripping. The current best practice in such cases includes: 1. Early debridement within 24 hours. 2. Skeletal stabilization to allow for further management. 3. Temporary wound coverage, often using negative pressure wound therapy (NPWT) to help reduce contamination, promote granulation tissue, and allow for delayed definitive soft tissue coverage. 4. Definitive soft tissue coverage (e.g., flap coverage) is generally done within 72 hours to 7 days depending on the case specifics and MDT planning. The other options are either: • Not applicable here (e.g., vascular shunting, as there’s no vascular injury), • Too delayed (e.g., combined reconstruction on a scheduled list), • Not indicated in this setting (e.g., fasciotomy unless compartment syndrome is present). This patient has a Gustillo-Anderson Grade 3B open fracture. He will require definitive skeletal and soft tissue reconstruction, which should be performed on a combined ortho-plastic scheduled operating list, as per the BOA/BAPRAS guidelines. The surgery does not have to be performed out of scheduled hours unless there is marine/ sewage contamination, vascular compromise or it is a polytrauma. Whilst it is reasonable to apply an external fixator prior to definitive skeletal and soft tissue reconstruction, this should be converted to internal fixation within 72 hours. Open fractures The term open fracture refers to a disruption of the bony cortex associated with a breach in the overlying skin. Any wound that is present in the same limb as a fracture should be suspected as being representative of an open fracture. One of the main problems with open fractures is the associated injuries to the surrounding soft tissues. Whilst the skin is usually relatively resistant to trauma, underlying muscle can be damaged or devitalised, nerves, blood vessels and periosteum may all be disrupted the degree to which this occurs correlates with the severity of the injury and the outcome. These can be graded using the Gustilo and Anderson system (see below). Grade Injury 1 Low energy wound <1cm 2 Greater than 1cm wound with moderate soft tissue damage 3 High energy wound > 10cm with extensive soft tissue damage 3 A (sub group of 3) Adequate soft tissue coverage 3 B (sub group of 3) Inadequate soft tissue coverage 3 C (sub group of 3) Associated arterial injury In Type IIIc injuries, the mangled extremity scoring system (MESS) can help to predict the need for primary amputation. Key points for initial management Remove obvious contaminants from very contaminated wounds in the ED Wound lavage should usually be undertaken in the OR Early wound photography should be performed Consider transfer of complex cases to centres that provide orthoplastic care All wounds should be managed within 24 hours and high velocity ones within 12 hours, those with vascular compromise should be managed immediately CT angiography is useful in delineating the extent of concommitant vascular injury

Answer 122

The IMA is usually divided during anterior resection. Not only is this borne out of oncological necessity but it also permits sufficient colonic mobilisation for anastomosis. Colon anatomy The colon commences with the caecum. This represents the most dilated segment of the human colon and its base (which is intraperitoneal) is marked by the convergence of teniae coli. At this point is located the vermiform appendix. The colon continues as the ascending colon, the posterior aspect of which is retroperitoneal. The line of demarcation between the intra and retro peritoneal right colon is visible as a white line, in the living, and forms the line of incision for colonic resections. The ascending colon becomes the transverse colon after passing the hepatic flexure. At this location the colon becomes wholly intra peritoneal once again. The superior aspect of the transverse colon is the point of attachment of the transverse colon to the greater omentum. This is an important anatomical site since division of these attachments permits entry into the lesser sac. Separation of the greater omentum from the transverse colon is a routine operative step in both gastric and colonic resections. At the left side of the abdomen the transverse colon passes to the left upper quadrant and makes an oblique inferior turn at the splenic flexure. Following this, the posterior aspect becomes retroperitoneal once again. At the level of approximately L4 the descending colon becomes wholly intraperitoneal and becomes the sigmoid colon. Whilst the sigmoid is wholly intraperitoneal there are usually attachments laterally between the sigmoid and the lateral pelvic sidewall. These small congenital adhesions are not formal anatomical attachments but frequently require division during surgical resections. At its distal end the sigmoid passes to the midline and at the region around the sacral promontary it becomes the upper rectum. This transition is visible macroscopically as the point where the teniae fuse. More distally the rectum passes through the peritoneum at the region of the peritoneal reflection and becomes extraperitoneal. Arterial supply Superior mesenteric artery and inferior mesenteric artery: linked by the marginal artery. Ascending colon: ileocolic and right colic arteries Transverse colon: middle colic artery Descending and sigmoid colon: inferior mesenteric artery Venous drainage From regional veins (that accompany arteries) to superior and inferior mesenteric vein Lymphatic drainage Initially along nodal chains that accompany supplying arteries, then para-aortic nodes. Embryology Midgut- Second part of duodenum to 2/3 transverse colon Hindgut- Distal 1/3 transverse colon to anus Peritoneal location The right and left colon are part intraperitoneal and part extraperitoneal. The sigmoid and transverse colon are generally wholly intraperitoneal. This has implications for the sequelae of perforations, which will tend to result in generalised peritonitis in the wholly intra peritoneal segments. Colonic relations Region of colon Relation Caecum/ right colon Right ureter, gonadal vessels Hepatic flexure Gallbladder (medially) Splenic flexure Spleen and tail of pancreas Distal sigmoid/ upper rectum Left ureter Rectum Ureters, autonomic nerves, seminal vesicles, prostate, urethra (distally)

Answer 123

Diverticular disease is the commonest cause of lower GI bleeding in adults. Diverticular associated bleeding is the commonest cause of lower GI bleeding in older adults and it is important to note that it is not associated with diverticulitis which seldom bleeds. Most cases will stop bleeding spontaneously. Lower Gastrointestinal bleeding Colonic bleeding This typically presents as bright red or dark red blood per rectum. Colonic bleeding rarely presents as malaena type stool, this is because blood in the colon has a powerful laxative effect and is rarely retained long enough for transformation to occur and because the digestive enzymes present in the small bowel are not present in the colon. Up to 15% of patients presenting with haemochezia will have an upper gastrointestinal source of haemorrhage. As a general rule right sided bleeds tend to present with darker coloured blood than left sided bleeds. Haemorrhoidal bleeding typically presents as bright red rectal bleeding that occurs post defecation either onto toilet paper or into the toilet pan. It is very unusual for haemorrhoids alone to cause any degree of haemodynamic compromise. Causes Cause Presenting features Colitis Bleeding may be brisk in advanced cases, diarrhoea is commonly present. Abdominal x-ray may show featureless colon. Diverticular disease Acute diverticulitis often is not complicated by major bleeding and diverticular bleeds often occur sporadically. 75% all will cease spontaneously within 24-48 hours. Bleeding is often dark and of large volume. Cancer Colonic cancers often bleed and for many patients this may be the first sign of the disease. Major bleeding from early lesions is uncommon Haemorrhoidal bleeding Typically bright red bleeding occurring post defecation. Although patients may give graphic descriptions bleeding of sufficient volume to cause haemodynamic compromise is rare. Angiodysplasia Apart from bleeding, which may be massive, these arteriovenous lesions cause little in the way of symptoms. The right side of the colon is more commonly affected. Management Prompt correction of any haemodynamic compromise is required. Unlike upper gastrointestinal bleeding the first line management is usually supportive. This is because in the acute setting endoscopy is rarely helpful. When haemorrhoidal bleeding is suspected a proctosigmoidoscopy is reasonable as attempts at full colonoscopy are usually time consuming and often futile. In the unstable patient the usual procedure would be an angiogram (either CT or percutaneous), when these are performed during a period of haemodynamic instability they may show a bleeding point and may be the only way of identifying a patch of angiodysplasia. In others who are more stable the standard procedure would be a colonoscopy in the elective setting. In patients undergoing angiography attempts can be made to address the lesion in question such as coiling. Otherwise surgery will be necessary. In patients with ulcerative colitis who have significant haemorrhage the standard approach would be a sub total colectomy, particularly if medical management has already been tried and is not effective. Indications for surgery Patients > 60 years Continued bleeding despite endoscopic intervention Recurrent bleeding Known cardiovascular disease with poor response to hypotension Surgery Selective mesenteric embolisation if life threatening bleeding. This is most helpful if conducted during a period of relative haemodynamic instability. If all haemodynamic parameters are normal then the bleeding is most likely to have stopped and any angiography normal in appearance. In many units a CT angiogram will replace selective angiography but the same caveats will apply. If the source of colonic bleeding is unclear; perform a laparotomy, on table colonic lavage and following this attempt a resection. A blind sub total colectomy is most unwise, for example bleeding from an small bowel arterio-venous malformation will not be treated by this manoeuvre. Summary of Acute Lower GI bleeding recommendations Consider admission if: * Over 60 years * Haemodynamically unstable/profuse PR bleeding * On aspirin or NSAID * Significant co morbidity Management All patients should have a history and examination, PR and proctoscopy Colonoscopic haemostasis aimed for in post polypectomy or diverticular bleeding

Answer 124

Retinal and cerebellar haemangiomas are key features of Von Hippel-Lindau syndrome. Retinal haemangiomas are bilateral in 25% of patients and may lead to vitreous haemorrhage Von Hippel-Lindau syndrome Von Hippel-Lindau (VHL) syndrome is an autosomal dominant condition predisposing to neoplasia. It is due to an abnormality in the VHL gene located on short arm of chromosome 3 Features cerebellar haemangiomas retinal haemangiomas: vitreous haemorrhage renal cysts (premalignant) phaeochromocytoma extra-renal cysts: epididymal, pancreatic, hepatic endolymphatic sac tumours

Answer 125

Carotid body tumours are the commonest type of head and neck paraganglionoma. Carotid body tumour These are rare tumours. However, they typically account for around 60% of head and neck paraganglionomas. They are usually tumours of middle age. Around 5% are bilateral and around 5% are malignant. They are rarely found as part of the MEN II or neurofibromatosis type I disease complexes. They typically present as an asymptomatic neck mass in the anterior triangle of the neck. They are typically slow growing lesions. Types of carotid body tumour Sporadic - Accounts for 85% of cases Familial - Seen in around 10% of cases and usually in younger patients Hyperplastic - Seen in those at high altitude or in those with COPD Imaging They are readily imaged using duplex ultrasonography. CT angiography is sometimes helpful. Treatment Typically this comprises surgical resection. This is preceded by embolization in selected cases.

Answer 126

The intragastric pH is usually 2. Administration of proton pump inhibitors can result in almost complete abolition of acidity Gastric secretions A working knowledge of gastric secretions is important for surgery because peptic ulcers are common, surgeons frequently prescribe anti secretory drugs and because there are still patients around who will have undergone acid lowering procedures (Vagotomy) in the past. Gastric acid Is produced by the parietal cells in the stomach pH of gastric acid is around 2 with acidity being maintained by the H+/K+ ATP ase pump. As part of the process bicarbonate ions will be secreted into the surrounding vessels. Sodium and chloride ions are actively secreted from the parietal cell into the canaliculus. This sets up a negative potential across the membrane and as a result sodium and potassium ions diffuse across into the canaliculus. Carbonic anhydrase forms carbonic acid which dissociates and the hydrogen ions formed by dissociation leave the cell via the H+/K+ antiporter pump. At the same time sodium ions are actively absorbed. This leaves hydrogen and chloride ions in the canaliculus these mix and are secreted into the lumen of the oxyntic gland. Phases of gastric acid secretion There are 3 phases of gastric secretion: 1. Cephalic phase (smell / taste of food) 30% acid produced Vagal cholinergic stimulation causing secretion of HCL and gastrin release from G cells 2. Gastric phase (distension of stomach ) 60% acid produced Stomach distension/low H+/peptides causes Gastrin release 3. Intestinal phase (food in duodenum) 10% acid produced High acidity/distension/hypertonic solutions in the duodenum inhibits gastric acid secretion via enterogastrones (CCK, secretin) and neural reflexes. Regulation of gastric acid production Factors increasing production include: Vagal nerve stimulation Gastrin release Histamine release (indirectly following gastrin release) from enterchromaffin like cells Factors decreasing production include: Somatostatin (inhibits histamine release) Cholecystokinin Secretin The diagram below illustrates some of the factors involved in regulating gastric acid secretion and the relevant associated pharmacology Below is a brief summary of the major hormones involved in food digestion: Source Stimulus Actions Gastrin G cells in antrum of the stomach Distension of stomach, extrinsic nerves Inhibited by: low antral pH, somatostatin Increase HCL, pepsinogen and IF secretion, increases gastric motility, trophic effect on gastric mucosa CCK I cells in upper small intestine Partially digested proteins and triglycerides Increases secretion of enzyme-rich fluid from pancreas, contraction of gallbladder and relaxation of sphincter of Oddi, decreases gastric emptying, trophic effect on pancreatic acinar cells, induces satiety Secretin S cells in upper small intestine Acidic chyme, fatty acids Increases secretion of bicarbonate-rich fluid from pancreas and hepatic duct cells, decreases gastric acid secretion, trophic effect on pancreatic acinar cells VIP Small intestine, pancreas Neural Stimulates secretion by pancreas and intestines, inhibits acid and pepsinogen secretion Somatostatin D cells in the pancreas and stomach Fat, bile salts and glucose in the intestinal lumen Decreases acid and pepsin secretion, decreases gastrin secretion, decreases pancreatic enzyme secretion, decreases insulin and glucagon secretion inhibits trophic effects of gastrin, stimulates gastric mucous production

Answer 127

The radial nerve runs in its groove on between the two heads. The ulnar nerve lies anterior to the medial head. The axillary nerve passes through the quadrangular space. This lies superior to lateral head of the triceps muscle and thus the lateral border of the quadrangular space is the humerus. Therefore the correct answer is the radial nerve. Triceps Origin Long head- infraglenoid tubercle of the scapula. Lateral head- dorsal surface of the humerus, lateral and proximal to the groove of the radial nerve Medial head- posterior surface of the humerus on the inferomedial side of the radial groove and both of the intermuscular septae Insertion Olecranon process of the ulna. Here the olecranon bursa is between the triceps tendon and olecranon. Some fibres insert to the deep fascia of the forearm, posterior capsule of the elbow (preventing the capsule from being trapped between olecranon and olecranon fossa during extension) Innervation Radial nerve Blood supply Profunda brachii artery Action Elbow extension. The long head can adduct the humerus and extend it from a flexed position Relations The radial nerve and profunda brachii vessels lie between the lateral and medial heads

Answer 128

Malunion would be unusual with a femoral neck fracture. Because it is a weight bearing joint, if the fracture is not united then it does not heal at all. It is for this reason that most femoral neck fractures are fixed. Avascular necrosis is a well recognised complication and a total hip replacement or hemiarthroplasty is usually considered in the elderly. Hip fractures Background Neck of femur (NOF) fracture is a common orthopaedic presentation, with over 65000 fractures in the UK per year. Like many orthopaedic injuries, there is a bimodal age distribution. It is imperative to distinguish between the high energy injury in a young patient, and the low energy osteoporotic fracture in the elderly, as their management aims are very different: Young patient - Usually high energy trauma (e.g road traffic accident, horse riding) and needs treating in accordance with Advanced Trauma Life Support (ATLS) principles. Will often have associated injuries. Aim is to retain the patients own anatomy, and optimise their function. Elderly patient - Predominantly female, fall from standing height (fragility fracture). Often patients have multiple comorbidities that will ultimately dictate their prognosis. Aim of orthopaedic treatment is to immediately regain patient mobility so that morbidity (infection, thromboembolic events, pressure sores etc) and mortality associated with prolonged bed rest is avoided. Left untreated, a neck of femur fracture can be considered a terminal event. Historically, mortality associated with elderly hip fracture is 10% at one month, and 30% at one year. However, this has been improved in the UK with the introduction of multidisciplinary, orthogeriatric lead care and the National Hip Fracture Database and Best Practice Tariff. Pertinent anatomy Osteology - normal neck-shaft angle is 130 +/- 7 degrees, and 10 +/- 7 degrees of neck anteversion. Vascular supply - The predominant blood supply to the femoral head and neck is from the medial and lateral femoral circumflex arteries (branches of profunda femoris). These anastomose and pierce the joint capsule at the base of the neck, mainly posteriorly. There is a small vascular contribution from the artery of the ligament teres. Understanding the blood supply is fundamental to the decision making process in treating NOF fractures. Presentation and initial management Typically, patients present with pain in the hip/groin, a shortened, abducted, externally rotated leg (due to the unopposed pull of the muscles that act across the hip joint) and the inability to straight-leg-raise. With undisplaced fractures, signs are more subtle. High energy injuries should be treated in line with ATLS principles. All patients should be fluid resuscitated, have adequate pain relief (often with a fascio-iliiaca nerve block), and be optimised for surgery. In addition, elderly patients should be assessed by an orthogeriatrician. Imaging Anteroposterior and cross-table lateral plain radiographs are sufficient to diagnose the majority of NOF fractures. If the fracture extends below the level of the lesser trochanter, or there is any possibility of pathological fracture, full length femur views are essential to plan surgery. Where there is a high index of suspicion of fracture, but plain radiographs are inconclusive, gold standard investigation is MRI. However, if unavailable within 24 hours, or if the patient will not tolerate MRI, CT is appropriate. The majority of fractures can be seen with modern CT techniques, and so this is becoming first line in many hospitals. Classification There has been a move away from named classification systems towards descriptive classification systems. Two main types of NOF exist: Intra-capsular, and extra-capsular. Extra-capsular fractures are further divided into pertrochanteric or subtrochanteric (within 5cm distal to the lesser trochanter). All fractures are then described as undisplaced, minimally displaced, or displaced. Femoral neck and head blood supply disruption is common with intracapsular NOF fractures, and rare with extracapsular fractures. This fundamental principle underpins the practise of arthroplasty for intracapsular fractures, and fixation for extracapsular fractures. If you wish to use a named classification system, the most commonly used are below: Elderly intracapsular - Garden Classification Young intrasapsular - Pauvels Classification Intertrochanteric - Evans Subtrochanteric - Russell Taylor Treatment In general, NOF fractures are treated operatively except if the patient is deemed unlikely to survive an anaesthetic. Best Practice Tarif (BPT) dictates that surgery should happen within 36 hours, as delay of greater than 48 hours is associated with increased morbidity and mortality. Below are suggested algorithms for the treatment of NOF. There are some areas of debate/controversy which are detailed below. * The priority with the young patient is to retain the femoral head if possible, even with a displaced intracapsular fracture. The risk of avascular necrosis and non-union (and therefore revision surgery) associated with internal fixation needs weighing up against the sequelae of total hip replacement in the young (wear, dislocation, revision). Discussion is necessary with the patient, on a case by case basis. ** Undisplaced fractures in the elderly can be treated with internal fixation, often with cannulated screws. This is appropriate for valgus impacted subcapital fractures which are inherently stable, to prevent secondary displacement. This does still carry the risk of AVN or non-union, and therefore a future revision. For this reason, many surgeons advocate arthroplasty as a single surgery. *** NICE guidance - patients who fulfil these criteria should be offered total hip replacement which conveys better function and prosthetic survivorship, compared with hemiarthroplasty, but at an increased risk of dislocation. * Intertrochanteric fractures vary greatly in their stability. If the trochanter (and therefore lateral wall), and medial calcar is in tact, then the fracture configuration bears stability. This can be treated with a DHS, as collapse of the fracture is predictable. Where either or both structures are involved in the fracture, stability becomes compromised and many surgeons will favour using an intramedullary device. This is an ongoing debate, and difficult to test in an exam setting. Post operative management Patients should be mobilised fully weight bearing where possible. Care is multidisciplinary in its delivery. Elderly patients should have orthogeriatrician assessment of comorbidity, and bone health with secondary prevention measures if appropriate. There should be early involvement of physiotherapy and occupational therapy services. For further guidance see sources listed below.

Answer 129

Sarcomas in which Lymphatic Metastasis is seen: 'RACE For MS' R: Rhabdomyosarcoma A: Angiosarcoma C: Clear cell sarcoma E: Epithelial cell sarcoma For: Fibrosarcoma M: Malignant fibrous histiocytoma S: Synovial cell sarcoma Or 'SCARE' Synovial sarcoma Clear cell sarcoma Angiosarcoma Rhabdomyosarcoma Epithelioid sarcoma Sarcomas often metastasise via the haematogenous route and the lung is a common site for sarcoma metastasis. The liver and brain are often spared (at least initially). A smaller number may develop lymphatic metastasis Sarcomas Malignant tumours of mesenchymal origin Types May be either bone or soft tissue in origin. Bone sarcoma include: Osteosarcoma Ewings sarcoma (although non bony sites recognised) Chondrosarcoma - originate from Chondrocytes Soft tissue sarcoma are a far more heterogeneous group and include: Liposarcoma-adipocytes Rhabdomyosarcoma-striated muscle Leiomyosarcoma-smooth muscle Synovial sarcomas- close to joints (cell of origin not known but not synovium) Malignant fibrous histiocytoma is now referred to as undifferentiated pleomorphic sarcoma. Careful histological assessment of lesions now allows more accurate categorisation of sarcoma subtypes than was previously possible. Features Certain features of a mass or swelling should raise suspicion for a sarcoma these include: Large >5cm soft tissue mass Deep tissue location or intra muscular location Rapid growth Painful lump Assessment Imaging of suspicious masses should utilise a combination of MRI, CT and USS. Blind biopsy should not be performed prior to imaging and where required should be done in such a way that the biopsy tract can be subsequently included in any resection. Ewings sarcoma Commoner in males Incidence of 0.3 / 1, 000, 000 Onset typically between 10 and 20 years of age Location by femoral diaphysis is commonest site Histologically it is a small round tumour Blood borne metastasis is common and chemotherapy is often combined with surgery Osteosarcoma Mesenchymal cells with osteoblastic differentiation 20% of all primary bone tumours Incidence of 5 per 1,000,000 Peak age 15-30, commoner in males Limb preserving surgery may be possible and many patients will receive chemotherapy Liposarcoma Malignancy of adipocytes Rare, approximately 2.5 per 1,000,000. They are the most common soft tissue sarcoma Typically located in deep locations such as retroperitoneum Affect older age group usually >40 years of age May be well differentiated and thus slow growing although may undergo de-differentiation and disease progression Many tumours will have a pseudocapsule that can misleadingly allow surgeons to feel that they can 'shell out' these lesions. In reality, tumour may invade at the edge of the pseudocapsule and result in local recurrence if this strategy is adopted Usually resistant to radiotherapy, although this is often used in a palliative setting Malignant Fibrous Histiocytoma Tumour with large number of histiocytes Also described as undifferentiated pleomorphic sarcoma NOS (i.e. Cell of origin is not known) Four major subtypes are recognised: storiform-pleomorphic (70% cases), myxoid (less aggressive), giant cell and inflammatory Treatment is usually with surgical resection and adjuvant radiotherapy as this reduces the likelihood of local recurrence

Answer 130

An ileus in itself is seldom a cause of a pyrexia. It may serve as a proxy marker of other complications. In this scenario atelectasis would be the most likely underlying cause, as open extended right hemicolectomies will necessitate a long midline incision. Anastomotic leaks are less common after right sided colonic surgery and the timeframe for it is rather short (but are possible). Both wound infections and UTI's ,may complicate major abdominal surgery at any stage. We remind you to check the wording of the question, it asks for the 'least likely' cause of pyrexia. Pyrexia- post operative Many surgical patients will develop a pyrexia post operatively. The cause and investigation depends upon the nature of the infection. The following scenarios may account for post operative pyrexia: Cause Features Anastomotic leak Swinging pyrexia Ileus Increasing abdominal pain Raised inflammatory markers Wound infection Evidence of superficial erythema, discharge of pus or increasing pain Usually mild pyrexia (unless major or deep seated wound infection) May be accompanied by evidence of wound dehisence Inflammatory markers raised Atelectasis Usually complicates abdominal surgery Most common after midline laparotomies (pain impairs ventilation) Pyrexia usually mild and non swinging Most patients will have chest signs on examination Inflammatory markers raised Central line sepsis Patients with complex venous access May have marked pyrexia Access site may show evidence of erythema Diagnosis is by blood culture from line, line removal and subsequent tip culture Groin lines and those for TPN have the highest risk Inflammatory markers raised Urinary tract infection Common in surgical patients Usually occur in patients with indwelling urinary catheters Diagnosis is by dipstick and CSU and signs of raised inflammatory markers Treatment is with antibiotics (to cover hospital acquired organisms)

Answer 131

In otherwise fit patients aged over 70, the best long term functional outcomes are obtained with total hip arthroplasty. Hip fractures Background Neck of femur (NOF) fracture is a common orthopaedic presentation, with over 65000 fractures in the UK per year. Like many orthopaedic injuries, there is a bimodal age distribution. It is imperative to distinguish between the high energy injury in a young patient, and the low energy osteoporotic fracture in the elderly, as their management aims are very different: Young patient - Usually high energy trauma (e.g road traffic accident, horse riding) and needs treating in accordance with Advanced Trauma Life Support (ATLS) principles. Will often have associated injuries. Aim is to retain the patients own anatomy, and optimise their function. Elderly patient - Predominantly female, fall from standing height (fragility fracture). Often patients have multiple comorbidities that will ultimately dictate their prognosis. Aim of orthopaedic treatment is to immediately regain patient mobility so that morbidity (infection, thromboembolic events, pressure sores etc) and mortality associated with prolonged bed rest is avoided. Left untreated, a neck of femur fracture can be considered a terminal event. Historically, mortality associated with elderly hip fracture is 10% at one month, and 30% at one year. However, this has been improved in the UK with the introduction of multidisciplinary, orthogeriatric lead care and the National Hip Fracture Database and Best Practice Tariff. Pertinent anatomy Osteology - normal neck-shaft angle is 130 +/- 7 degrees, and 10 +/- 7 degrees of neck anteversion. Vascular supply - The predominant blood supply to the femoral head and neck is from the medial and lateral femoral circumflex arteries (branches of profunda femoris). These anastomose and pierce the joint capsule at the base of the neck, mainly posteriorly. There is a small vascular contribution from the artery of the ligament teres. Understanding the blood supply is fundamental to the decision making process in treating NOF fractures. Presentation and initial management Typically, patients present with pain in the hip/groin, a shortened, abducted, externally rotated leg (due to the unopposed pull of the muscles that act across the hip joint) and the inability to straight-leg-raise. With undisplaced fractures, signs are more subtle. High energy injuries should be treated in line with ATLS principles. All patients should be fluid resuscitated, have adequate pain relief (often with a fascio-iliiaca nerve block), and be optimised for surgery. In addition, elderly patients should be assessed by an orthogeriatrician. Imaging Anteroposterior and cross-table lateral plain radiographs are sufficient to diagnose the majority of NOF fractures. If the fracture extends below the level of the lesser trochanter, or there is any possibility of pathological fracture, full length femur views are essential to plan surgery. Where there is a high index of suspicion of fracture, but plain radiographs are inconclusive, gold standard investigation is MRI. However, if unavailable within 24 hours, or if the patient will not tolerate MRI, CT is appropriate. The majority of fractures can be seen with modern CT techniques, and so this is becoming first line in many hospitals. Classification There has been a move away from named classification systems towards descriptive classification systems. Two main types of NOF exist: Intra-capsular, and extra-capsular. Extra-capsular fractures are further divided into pertrochanteric or subtrochanteric (within 5cm distal to the lesser trochanter). All fractures are then described as undisplaced, minimally displaced, or displaced. Femoral neck and head blood supply disruption is common with intracapsular NOF fractures, and rare with extracapsular fractures. This fundamental principle underpins the practise of arthroplasty for intracapsular fractures, and fixation for extracapsular fractures. If you wish to use a named classification system, the most commonly used are below: Elderly intracapsular - Garden Classification Young intrasapsular - Pauvels Classification Intertrochanteric - Evans Subtrochanteric - Russell Taylor Treatment In general, NOF fractures are treated operatively except if the patient is deemed unlikely to survive an anaesthetic. Best Practice Tarif (BPT) dictates that surgery should happen within 36 hours, as delay of greater than 48 hours is associated with increased morbidity and mortality. Below are suggested algorithms for the treatment of NOF. There are some areas of debate/controversy which are detailed below. * The priority with the young patient is to retain the femoral head if possible, even with a displaced intracapsular fracture. The risk of avascular necrosis and non-union (and therefore revision surgery) associated with internal fixation needs weighing up against the sequelae of total hip replacement in the young (wear, dislocation, revision). Discussion is necessary with the patient, on a case by case basis. ** Undisplaced fractures in the elderly can be treated with internal fixation, often with cannulated screws. This is appropriate for valgus impacted subcapital fractures which are inherently stable, to prevent secondary displacement. This does still carry the risk of AVN or non-union, and therefore a future revision. For this reason, many surgeons advocate arthroplasty as a single surgery. *** NICE guidance - patients who fulfil these criteria should be offered total hip replacement which conveys better function and prosthetic survivorship, compared with hemiarthroplasty, but at an increased risk of dislocation. * Intertrochanteric fractures vary greatly in their stability. If the trochanter (and therefore lateral wall), and medial calcar is in tact, then the fracture configuration bears stability. This can be treated with a DHS, as collapse of the fracture is predictable. Where either or both structures are involved in the fracture, stability becomes compromised and many surgeons will favour using an intramedullary device. This is an ongoing debate, and difficult to test in an exam setting. Post operative management Patients should be mobilised fully weight bearing where possible. Care is multidisciplinary in its delivery. Elderly patients should have orthogeriatrician assessment of comorbidity, and bone health with secondary prevention measures if appropriate. There should be early involvement of physiotherapy and occupational therapy services.

Answer 132

It terminates at the upper border of the thyroid cartilage, Which is usually located at C4. Common carotid artery The right common carotid artery arises at the bifurcation of the brachiocephalic trunk, the left common carotid arises from the arch of the aorta. Both terminate at the level of the upper border of the thyroid cartilage (the lower border of the third cervical vertebra) by dividing into the internal and external carotid arteries. Left common carotid artery This vessel arises immediately to the left and slightly behind the origin of the brachiocephalic trunk. Its thoracic portion is 2.5- 3.5 cm in length and runs superolaterally to the sternoclavicular joint. In the thorax The vessel is in contact, from below upwards, with the trachea, left recurrent laryngeal nerve, left margin of the oesophagus. Anteriorly the left brachiocephalic vein runs across the artery, and the cardiac branches from the left vagus descend in front of it. These structures together with the thymus and the anterior margins of the left lung and pleura separate the artery from the manubrium. In the neck The artery runs superiorly deep to sternocleidomastoid and then enters the anterior triangle. At this point it lies within the carotid sheath with the vagus nerve and the internal jugular vein. Posteriorly the sympathetic trunk lies between the vessel and the prevertebral fascia. At the level of C7 the vertebral artery and thoracic duct lie behind it. The anterior tubercle of C6 transverse process is prominent and the artery can be compressed against this structure (it corresponds to the level of the cricoid). Anteriorly at C6 the omohyoid muscle passes superficial to the artery. Within the carotid sheath the jugular vein lies lateral to the artery. Right common carotid artery The right common carotid arises from the brachiocephalic artery. The right common carotid artery corresponds with the cervical portion of the left common carotid, except that there is no thoracic duct on the right. The oesophagus is less closely related to the right carotid than the left. Summary points about the carotid anatomy Path Passes behind the sternoclavicular joint (12% patients above this level) to the upper border of the thyroid cartilage, to divide into the external (ECA) and internal carotid arteries (ICA). Relations Level of 6th cervical vertebra crossed by omohyoid Then passes deep to the thyrohyoid, sternohyoid, sternomastoid muscles. Passes anterior to the carotid tubercle (transverse process 6th cervical vertebra)-NB compression here stops haemorrhage. The inferior thyroid artery passes posterior to the common carotid artery. Then : Left common carotid artery crosses the thoracic duct, Right common carotid artery crossed by recurrent laryngeal nerve

Answer 133

Proximally sited atresia will produce high volume vomits which may or may not be bile stained. Abdominal distension is characteristically absent. Whilst under resuscitated children may be a little dehydrated they are seldom severely ill. The presence of Trisomy 21 (palmar and eye signs) increases the likelihood of duodenal atresia. Bilious vomiting in neonates Causes of intestinal obstruction with bilious vomiting in neonates Disorder Incidence and causation Age at presentation Diagnosis Treatment Duodenal atresia 1 in 5000 (higher in Downs syndrome) Few hours after birth AXR shows 'double bubble sign, contrast study may confirm Duodenoduodenostomy Malrotation with volvulus Usually cause by incomplete rotation during embryogenesis Usually 3-7 days after birth, volvulus with compromised circulation may result in peritoneal signs and haemodynamic instability Upper GI contrast study may show DJ flexure is more medially placed, USS may show abnormal orientation of SMA and SMV Ladd's procedure Jejunal/ ileal atresia Usually caused by vascular insufficiency in utero, usually 1 in 3000 Usually within 24 hours of birth AXR will show air-fluid levels Laparotomy with primary resection and anastomosis Meconium ileus Occurs in between 15 and20% of those babies with cystic fibrosis, otherwise 1 in 5000 Typically in first 24-48 hours of life with abdominal distension and bilious vomiting Air - fluid levels on AXR, sweat test to confirm cystic fibrosis Surgical decompression, serosal damage may require segmental resection Necrotising enterocolitis Up to 2.4 per 1000 births, risks increased in prematurity and inter-current illness Usually second week of life Dilated bowel loops on AXR, pneumatosis and portal venous air Conservative and supportive for non perforated cases, laparotomy and resection in cases of perforation of ongoing clinical deteriorat

Answer 134

The lobule of the ear drains to the superficial cervical nodes. Lymphatic drainage of the auricle Lymphatic Drainage The lateral surface of the upper half drains to the superficial parotid lymph nodes The cranial surface of the superior half drains to the mastoid nodes and deep cervical lymph nodes The lower half and lobule drain into the superficial cervical lymph nodes.

Answer 135

Fromen's test, also known as the Fromen (or Froment) sign, is a clinical test used to evaluate the function of the ulnar nerve, specifically assessing the strength of the adductor pollicis muscle. Here is how it is typically performed: 1. The patient is asked to hold a piece of paper between their thumb and index finger. 2. The examiner attempts to pull the paper away. In a positive Fromen's sign, the patient compensates for a weak adductor pollicis by flexing the thumb's interphalangeal joint, which is facilitated by the flexor pollicis longus muscle, innervated by the median nerve. This compensation indicates weakness or paralysis of the adductor pollicis muscle due to ulnar nerve dysfunction. Fromen's test can be useful in diagnosing conditions that affect the ulnar nerve, such as cubital tunnel syndrome or ulnar neuropathy. Assess for ulnar nerve palsy Adductor pollicis muscle function tested Hold a piece of paper between their thumb and index finger. The object is then pulled away. If ulnar nerve palsy, unable to hold the paper and will flex the flexor pollicis longus to compensate (flexion of thumb at interphalangeal joint). Phalen's test Assess carpal tunnel syndrome More sensitive than Tinel's sign Hold wrist in maximum flexion and the test is positive if there is numbness in the median nerve distribution. Tinel's sign Assess for carpal tunnel syndrome Tap the median nerve at the wrist and the test is positive if there is tingling/electric-like sensations over the distribution of the median nerve.

Answer 136

The keyword here is suspected. That being the case the investigation is CT. Although it is known that ionising radiation exposure can lead to cell death, mutation of germ cells, and carcinogenesis, there is no common modern radiographic procedure that results in radiation exposure to a level that threatens embryo or fetal well-being.Radiation exposure of <5 rads (a computed tomographic abdomen/pelvis study carries an exposure of 3.5 rads) has not been associated with fetal defects or loss. Careful shielding of the patient can also minimise exposure. Importantly, the use of ultrasound for diagnosis is clearly safe in pregnancy, although it should be used to evaluate and answer a defined clinical problem. A negative laparoscopy/ laparotomy poses signifcant foetal risks and at either procedure the enlarged uterus can result in missed pathology. Abdominal imaging in pregnancy Pregnant patients will often present with abdominal pain and the co-existing physiological leucocytosis can make laboratory assessment less reliable. In the non pregnant patient there is a low threshold for cross sectional imaging with CT scanning. The main foetal risks from cross sectional imaging in pregnancy are delayed rather than immediate. That being the case, where CT is likely to facilitate accurate diagnosis that improves short term foetal outcomes or saves foetal life, it is justified. At all times, alternatives to CT need to be considered and utilised where possible. MRI is often used though for complex sequences movement artifact can limit the quality of views obtained. The use of shields can also limit radiation exposure to the foetus.

Answer 137

The event occurring at day 12 with right sided ECG changes all favor PE. Surgery and cancer are risk factors. Pneumothorax would tend to occur much earlier in the post operative period. Pulmonary Embolism: ECG changes - No changes S1, Q3, T3 Tall R waves: V1 P pulmonale (peaked P waves): inferior leads Right axis deviation, Right bundle branch block Atrial arrhythmias T wave inversion: V1, V2, V3 Right ventricular strain: if identified is associated with adverse short-term outcome and adds prognostic value to echocardiographic evidence of right ventricular dysfunction in patients with acute pulmonary embolism and normal blood pressure.

Answer 138

Based on the information provided, the most likely diagnosis for this 12-year-old obese boy is: Slipped Upper Femoral Epiphysis (SUFE) Here's why this is the most probable diagnosis: 1. Age and body habitus: SUFE typically occurs in adolescents, often during growth spurts. It is more common in obese children, which matches the description of this patient. 2. Symptoms: - Pain in the hip and knee: SUFE often presents with hip pain that can be referred to the knee. - Antalgic gait: This is a common finding in SUFE, where the patient tries to avoid putting weight on the affected side. 3. Physical examination: - Limitation of internal rotation: This is a classic sign of SUFE. The slippage of the femoral head causes restricted internal rotation of the hip. - Normal knee examination: The knee pain is referred from the hip, so the knee itself shows no abnormalities on examination. Let's briefly consider why the other options are less likely: - Septic arthritis: This would typically present with more acute symptoms, fever, and more severe limitation of movement. - Developmental dysplasia of the hip: This is usually diagnosed in infancy or early childhood, not at 12 years old. - Perthes disease: While possible, it's less common in obese children and typically affects younger children (4-8 years old). - Osteoarthritis of the hip: This is extremely rare in a 12-year-old and would not be a primary consideration. Given the patient's age, obesity, symptoms, and examination findings, Slipped Upper Femoral Epiphysis (SUFE) is the most likely diagnosis. This condition requires prompt recognition and treatment to prevent further slippage and potential complications. Slipped upper femoral epiphysis is commonest in obese adolescent males. The x-ray will show displacement of the femoral epiphysis inferolaterally. Treatment is usually with rest and non weight bearing crutches. Paediatric orthopaedics Diagnosis Mode of presentation Treatment Radiology Developmental dysplasia of the hip Usually diagnosed in infancy by screening tests. May be bilateral, when disease is unilateral there may be leg length inequality. As disease progresses child may limp and then early onset arthritis. More common in extended breech babies. Splints and harnesses or traction. In later years osteotomy and hip realignment procedures may be needed. In arthritis a joint replacement may be needed. However, this is best deferred if possible as it will almost certainly require revision Initially no obvious change on plain films and USS gives best resolution until 3 months of age. On plain films Shentons line should form a smooth arc Perthes Disease Hip pain (may be referred to the knee) usually occurring between 5 and 12 years of age. Bilateral disease in 20%. Remove pressure from joint to allow normal development. Physiotherapy. Usually self-limiting if diagnosed and treated promptly. X-rays will show flattened femoral head. Eventually in untreated cases the femoral head will fragment. Slipped upper femoral epiphysis Typically seen in obese male adolescents. Pain is often referred to the knee. Limitation to internal rotation is usually seen. Knee pain is usually present 2 months prior to hip slipping. Bilateral in 20%. Bed rest and non-weight bearing. Aim to avoid avascular necrosis. If severe slippage or risk of it occurring then percutaneous pinning of the hip may be required. X-rays will show the femoral head displaced and falling inferolaterally (like a melting ice cream cone) The Southwick angle gives indication of disease severity

Answer 139

The musculocutaneous nerve lies between the biceps and brachialis muscles. Musculocutaneous nerve Branch of lateral cord of brachial plexus Path It penetrates the coracobrachialis muscle Passes obliquely between the biceps brachii and the brachialis to the lateral side of the arm Above the elbow it pierces the deep fascia lateral to the tendon of the biceps brachii Continues into the forearm as the lateral cutaneous nerve of the forearm Innervates Coracobrachialis Biceps brachii Brachialis

Answer 140

Ovarian tumours are supplied by the ovarian vessels, these branch directly from the aorta. The cervix drains to the internal and external iliac nodes. Para-aortic lymphadenopathy Organ sites that may metastasise (early) to the para-aortic lymph nodes: Testis Ovary Uterine fundus Many other organs may result in para-aortic nodal disease. However, these deposits will represent a much later stage of the disease, since other nodal stations are involved earlier.

Answer 141

The dorsalis pedis is a continuation of the anterior tibial artery. Foot- anatomy Arches of the foot The foot is conventionally considered to have two arches. The longitudinal arch is higher on the medial than on the lateral side. The posterior part of the calcaneum forms a posterior pillar to support the arch. The lateral part of this structure passes via the cuboid bone and the lateral two metatarsal bones. The medial part of this structure is more important. The head of the talus marks the summit of this arch, located between the sustentaculum tali and the navicular bone. The anterior pillar of the medial arch is composed of the navicular bone, the three cuneiforms and the medial three metatarsal bones. The transverse arch is situated on the anterior part of the tarsus and the posterior part of the metatarsus. The cuneiforms and metatarsal bases narrow inferiorly, which contributes to the shape of the arch. Intertarsal joints Sub talar joint Formed by the cylindrical facet on the lower surface of the body of the talus and the posterior facet on the upper surface of the calcaneus. The facet on the talus is concave anteroposteriorly, the other is convex. The synovial cavity of this joint does not communicate with any other joint. Talocalcaneonavicular joint The anterior part of the socket is formed by the concave articular surface of the navicular bone, posteriorly by the upper surface of the sustentaculum tali. The talus sits within this socket Calcaneocuboid joint Highest point in the lateral part of the longitudinal arch. The lower aspect of this joint is reinforced by the long plantar and plantar calcaneocuboid ligaments. Transverse tarsal joint The talocalcaneonavicular joint and the calcaneocuboid joint extend across the tarsus in an irregular transverse plane, between the talus and calcaneus behind and the navicular and cuboid bones in front. This plane is termed the transverse tarsal joint. Cuneonavicular joint Formed between the convex anterior surface of the navicular bone and the concave surface of the the posterior ends of the three cuneiforms. Intercuneiform joints Between the three cuneiform bones. Cuneocuboid joint Between the circular facets on the lateral cuneiform bone and the cuboid. This joint contributes to the tarsal part of the transverse arch. A detailed knowledge of the joints is not required for MRCS Part A. However, the contribution they play to the overall structure of the foot should be appreciated Muscles of the foot Muscle Origin Insertion Nerve supply Action Abductor hallucis Medial side of the calcaneus, flexor retinaculum, plantar aponeurosis Medial side of the base of the proximal phalanx Medial plantar nerve Abducts the great toe Flexor digitorum brevis Medial process of the calcaneus, plantar eponeurosis. Via 4 tendons into the middle phalanges of the lateral 4 toes. Medial plantar nerve Flexes all the joints of the lateral 4 toes except for the interphalangeal joint. Abductor digit minimi From the tubercle of the calcaneus and from the plantar aponeurosis Together with flexor digit minimi brevis into the lateral side of the base of the proximal phalanx of the little toe Lateral plantar nerve Abducts the little toe at the metatarsophalangeal joint Flexor hallucis brevis From the medial side of the plantar surface of the cuboid bone, from the adjacent part of the lateral cuneiform bone and from the tendon of tibialis posterior. Into the proximal phalanx of the great toe, the tendon contains a sesamoid bone Medial plantar nerve Flexes the metatarsophalangeal joint of the great toe. Adductor hallucis Arises from two heads. The oblique head arises from the sheath of the peroneus longus tendon, and from the plantar surfaces of the bases of the 2nd, 3rd and 4th metatarsal bones. The transverse head arises from the plantar surface of the lateral 4 metatarsophalangeal joints and from the deep transverse metatarsal ligament. Lateral side of the base of the proximal phalanx of the great toe. Lateral plantar nerve Adducts the great toe towards the second toe. Helps maintain the transverse arch of the foot. Extensor digitorum brevis On the dorsal surface of the foot from the upper surface of the calcaneus and its associated fascia Via four thin tendons which run forward and medially to be inserted into the medial four toes. The lateral three tendons join with hoods of extensor digitorum longus. Deep peroneal Extend the metatarsophalangeal joint of the medial four toes. It is unable to extend the interphalangeal joint without the assistance of the lumbrical muscles. Nerves in the foot Lateral plantar nerve Passes anterolaterally towards the base of the 5th metatarsal between flexor digitorum brevis and flexor accessorius. On the medial aspect of the lateral plantar artery. At the base of the 5th metatarsal it splits into superficial and deep branches. Medial plantar nerve Passes forwards with the medial plantar artery under the cover of the flexor retinaculum to the interval between abductor hallucis and flexor digitorum brevis on the sole of the foot. Plantar arteries Arise under the cover of the flexor retinaculum, midway between the tip of the medial malleolus and the most prominent part of the medial side of the heel. Medial plantar artery. Passes forwards medial to medial plantar nerve in the space between abductor hallucis and flexor digitorum brevis.Ends by uniting with a branch of the 1st plantar metatarsal artery. Lateral plantar artery. Runs obliquely across the sole of the foot. It lies lateral to the lateral plantar nerve. At the base of the 5th metatarsal bone it arches medially across the foot on the metatarsals Dorsalis pedis artery This vessel is a direct continuation of the anterior tibial artery. It commences on the front of the ankle joint and runs to the proximal end of the first metatarsal space. Here is gives off the arcuate artery and continues forwards as the first dorsal metatarsal artery. It is accompanied by two veins throughout its length. It is crossed by the extensor hallucis brevis

Answer 142

The glossopharyngeal nerve supplies the taste and general sensation to the posterior third of the tongue. Tongue The tongue is a muscular organ concerned with both feeding and speech. It is shaped like an inverted boot with a root through which extrinsic muscles pass to attach it to the soft palate, the styloid process, the hyoid bone and the mandible. It has a body that comprises muscle intermingled with lingual salivary glands, connective tissue, nerves, vessels and lymphatic follicles. The dorsum of the tongue is divided by an ill defined V shaped groove, the sulcus terminalis, into an anterior two thirds and a posterior third. The arterial blood supply to the tongue is from the paired sets of lingual arteries that arise from the external carotid. The venous drainage is via dorsal lingual veins which then join the lingual veins and eventually into the sublingual vein. The nerve supply is as follows: The lingual branch of the mandibular division of the trigeminal nerve supplies common sensation to the anterior two thirds The chorda tympani branch of the facial nerve supplies taste to the anterior two thirds The lingual branch of the glossopharyngeal nerve supplies common sensation and taste to the posterior third of the tongue All intrinsic muscles of the tongue are supplied by the hypoglossal nerve

Answer 143

Bleeding post operatively, epistaxis and menorrhagia may indicate a diagnosis of vWD. Haemoarthroses are rare. The bleeding time is usually normal in haemophilia (X-linked) and vitamin K deficiency. von Willebrands disease - Most common inherited bleeding disorder All vWD is caused by mutations in the gene for von Willebrand factor. von Willebrand factor is an adhesive glycoprotein that is secreted by endothelium and megakaryocytes von Willebrand factor promotes platelet adhesion to damaged endothelium and other platelets. It is also involved in the transport and stabilization of factor VIII There are 7 subtypes of von Willebrand disease. The commonest is type I (autosomal dominant) which accounts for 80% of cases, type 2vWD (autosomal dominant or recessive) accounts for 15% of cases There is a significant spectrum of severity ranging from spontaneous bleeding and epistaxis through to troublesome excessive bleeding following minor procedures The test that is most commonly used are von willebrand factor assays Treatments include administration of tranexamic acid for minor cases undergoing minor procedures. More significant bleeding or more significant procedures respond well to DDAVP. This is most effective in type I, less effective in type 2 and contraindicated in type 2B. Patients with type 3 disease do not respond to DDAVP as they lack the ability to secrete vWF Individuals who cannot have DDAVP or in whom it is contra indicated usually receive factor VIII concentrates containing vWF

Answer 144

Neostigmine can cause bradycardia and atropine is often administered concomitantly to counter this effect. Muscle relaxants Suxamethonium Depolarising neuromuscular blocker Inhibits action of acetylcholine at the neuromuscular junction Degraded by plasma cholinesterase and acetylcholinesterase (affected by lack of acetylcholinesterase) Fastest onset and shortest duration of action of all muscle relaxants Produces generalised muscular contraction prior to paralysis Adverse effects include hyperkalaemia, malignant hyperthermia, delayed recovery Atracurium Non depolarising neuromuscular blocking drug Duration of action usually 30-45 minutes Generalised histamine release on administration may produce facial flushing, tachycardia and hypotension Not excreted by liver or kidney, broken down in tissues by hydrolysis Reversed by neostigmine Vecuronium Non depolarising neuromuscular blocking drug Duration of action approximately 30 - 40 minutes Degraded by liver and kidney and effects prolonged in organ dysfunction Effects may be reversed by neostigmine Pancuronium Non depolarising neuromuscular blocker Onset of action approximately 2-3 minutes Duration of action up to 2 hours Effects may be partially reversed with drugs such as neostigmine

Answer 145

In NF2 bilateral acoustic neuromas are characteristic with a family history of Neurofibroma. Genetics and surgical disease Some of the more commonly occurring genetic conditions occurring in surgical patients are presented here. Li-Fraumeni Syndrome Autosomal dominant Consists of germline mutations to p53 tumour suppressor gene High incidence of malignancies particularly sarcomas and leukaemias Diagnosed when: *Individual develops sarcoma under 45 years *First degree relative diagnosed with any cancer below age 45 years and another family member develops malignancy under 45 years or sarcoma at any age BRCA 1 and 2 Carried on chromosome 17 (BRCA 1) and Chromosome 13 (BRCA 2) Linked to developing breast cancer (60%) risk. Associated risk of developing ovarian cancer (55% with BRCA 1 and 25% with BRCA 2). Lynch Syndrome Autosomal dominant Develop colonic cancer and endometrial cancer at young age 80% of affected individuals will get colonic and/ or endometrial cancer High risk individuals may be identified using the Amsterdam criteria Amsterdam criteria Three or more family members with a confirmed diagnosis of colorectal cancer, one of whom is a first degree (parent, child, sibling) relative of the other two. Two successive affected generations. One or more colon cancers diagnosed under age 50 years. Familial adenomatous polyposis (FAP) has been excluded. Gardners syndrome Autosomal dominant familial colorectal polyposis Multiple colonic polyps Extra colonic diseases include: skull osteoma, thyroid cancer and epidermoid cysts Desmoid tumours are seen in 15% Mutation of APC gene located on chromosome 5 Due to colonic polyps most patients will undergo colectomy to reduce risk of colorectal cancer Now considered a variant of familial adenomatous polyposis coli

Answer 146

The deep external pudendal artery is a branch of the SFA and it runs medially under the long saphenous vein near its point of union with the femoral vein. The superficial external pudendal artery lies superior to the SFJ. Neither vessel is functionally important and if injured they are best ligated. Femoral triangle anatomy Boundaries Superiorly Inguinal ligament Laterally Sartorius Medially Adductor longus Floor Iliopsoas, adductor longus and pectineus Roof Fascia lata and Superficial fascia Superficial inguinal lymph nodes (palpable below the inguinal ligament) Long saphenous vein

Answer 147

Superior and inferior gluteal nerve Superior gluteal nerve Arises from dorsal surface of the sacral plexus (L4, L5, S1) Passes into gluteal region together with superior gluteal vessels Supplies gluteus medius and minimus Inferior gluteal nerve Arises from dorsal surface of sacral plexus (L5, S1 and S2) Runs medial to the posterior femoral cutaneous nerve Enters gluteal region at inferior border of piriformis Supplies gluteus maximus

Answer 148

Given the patient's history of a previous esophagectomy and the current need for long-term feeding due to an unsafe swallow, the best option for long-term feeding would be: **Surgically inserted feeding jejunostomy tube** Here's why: 1. **Previous Esophagectomy**: This history complicates the placement of a percutaneous endoscopic gastrostomy (PEG) tube, whether endoscopic or surgical, as the anatomy may be altered significantly. 2. **Safety Concerns**: A feeding jejunostomy tube can bypass the stomach and esophagus altogether, effectively preventing potential complications related to his previous esophagectomy. 3. **Long-term Feeding**: A surgically inserted jejunostomy tube is suitable for long-term nutritional support, especially in patients where the upper gastrointestinal tract cannot be used safely. 4. **TPN (Total Parenteral Nutrition)**: While TPN can be used for nutritional support, it is generally considered as a last resort due to the high risk of complications such as infections, liver dysfunction, and metabolic disturbances, especially over the long term. Peripheral TPN is not suitable for long-term use, and central TPN carries significant risks. Therefore, the most appropriate and safest option for long-term feeding in this patient is the surgically inserted feeding jejunostomy tube.

Answer 149

Oxyphil cells are typically found in parathyroid glands. Parathyroid glands- anatomy Four parathyroid glands Located posterior to the thyroid gland They lie within the pretracheal fascia Embryology The parathyroids develop from the extremities of the third and fourth pharyngeal pouches. The parathyroids derived from the fourth pharyngeal pouch are located more superiorly and are associated with the thyroid gland. Those derived from the third pharyngeal pouch lie more inferiorly and may become associated with the thymus. Blood supply The blood supply to the parathyroid glands is derived from the inferior and superior thyroid arteries[1]. There is a rich anastomosis between the two vessels. Venous drainage is into the thyroid veins. Relations Laterally Common carotid Medially Recurrent laryngeal nerve, trachea Anterior Thyroid Posterior Pretracheal fascia

Answer 150

Any advanced right iliac fossa pathology can result in a positive Rovsings sign. However, in retrocaecal appendicitis, it may be absent and this fact can contribute to a delayed diagnosis if undue weight is placed on the presence of the sign in making the diagnosis.

Answer 151

This is likely to represent epididymo-orchitis, this is usually due to infection with gonorrhoea or chlamydia in this age group. In addition to treatment with antibiotics contact tracing and appropriate swabs should also be performed. Testicular disorders Testicular cancer Testicular cancer is the most common malignancy in men aged 20-30 years. Around 95% of cases of testicular cancer are germ-cell tumours. Germ cell tumours may essentially be divided into: Tumour type Key features Tumour markers Pathology Seminoma Commonest subtype (50%) Average age at diagnosis = 40 Even advanced disease associated with 5 year survival of 73% AFP usually normal HCG elevated in 10% seminomas Lactate dehydrogenase; elevated in 10-20% seminomas (but also in many other conditions) Sheet like lobular patterns of cells with substantial fibrous component. Fibrous septa contain lymphocytic inclusions and granulomas may be seen. Non seminomatous germ cell tumours (42%) Teratoma Yolk sac tumour Choriocarcinoma Mixed germ cell tumours (10%) Younger age at presentation =20-30 years Advanced disease carries worse prognosis (48% at 5 years) Retroperitoneal lymph node dissection may be needed for residual disease after chemotherapy Risk factors for testicular cancer Cryptorchidism Infertility Family history Klinefelter's syndrome Mumps orchitis Features A painless lump is the most common presenting symptom Pain may also be present in a minority of men Other possible features include hydrocele, gynaecomastia Diagnosis Ultrasound is first-line CT scanning of the chest/ abdomen and pelvis is used for staging Tumour markers (see above) should be measured Management Orchidectomy (Inguinal approach) Chemotherapy and radiotherapy may be given depending on staging Abdominal lesions >1cm following chemotherapy may require retroperitoneal lymph node dissection. Prognosis is generally excellent 5 year survival for seminomas is around 95% if Stage I 5 year survival for teratomas is around 85% if Stage I Benign disease Epididymo-orchitis Acute epididymitis is an acute inflammation of the epididymis, often involving the testis and usually caused by bacterial infection. Infection spreads from the urethra or bladder. In men <35 years, gonorrhoea or chlamydia are the usual infections. Amiodarone is a recognised non infective cause of epididymitis, which resolves on stopping the drug. Tenderness is usually confined to the epididymis, which may facilitate differentiating it from torsion where pain usually affects the entire testis. Testicular torsion Twist of the spermatic cord resulting in testicular ischaemia and necrosis. Most common in males aged between 10 and 30 (peak incidence 13-15 years) Pain is usually severe and of sudden onset. Cremasteric reflex is lost and elevation of the testis does not ease the pain. Treatment is with surgical exploration. If a torted testis is identified then both testis should be fixed as the condition of bell clapper testis is often bilateral. Hydrocele Presents as a mass that transilluminates, usually possible to 'get above' it on examination. In younger men it should be investigated with USS to exclude tumour. In children it may occur as a result of a patent processus vaginalis. Treatment in adults is with a Lords or Jabouley procedure. Treatment in children is with trans inguinal ligation of PPV.

Answer 152

0.45% saline/ 5% glucose solutions carry a risk of hyponatraemia and is contra indicated- see below. Paediatric fluid management Since 2000 there have been at least 4 reported deaths from fluid induced hyponatraemia in children. This led to the National Patient Safety Agency introducing revised guidelines in 2007. These have been reviewed and extensively updated by NICE in 2015 and further modified in 2020. Indications for IV fluids include: Resuscitation and circulatory support Replacing on-going fluid losses Maintenance fluids for children for whom oral fluids are not appropriate Correction of electrolyte disturbances Fluids to be avoided Outside the neonatal period saline / glucose solutions should not be given. The greatest risk is with saline 0.18 / glucose 4% solutions. The report states that 0.45% saline / 5% glucose may be used. But preference should be given to isotonic solutions and few indications exist for this solution either. The key point emphasised in the NICE guidelines in the avoidance of glucose containing solutions and instead of routinely giving glucose IV to children and neonates, the blood glucose levels should be monitored. In neonates in the first few days of life, sodium levels in the range of 131-154 mmol/l may be too high and a neonatologist consulted on a case by case basis. Fluids to be used If children and young people need IV fluids for routine maintenance, initially use isotonic crystalloids that contain sodium in the range 131 to 154 mmol/litre Potassium should be added to maintenance fluids according patients plasma potassium levels (which should be monitored). Blood glucose levels should be monitored in individuals at risk of hypoglycaemia Intraoperative fluid management If children and young people need IV fluids for routine maintenance, initially use isotonic crystalloids that contain sodium in the range 131 to 154 mmol/litre Blood glucose levels should be monitored Maintenance fluids Weight Water requirement/kg/day Na mmol/kg/day K mmol/kg/day First 10Kg body weight 100ml 2-4 1.5-2.5 Second 10Kg body weight 50ml 1-2 0.5-1.5 Subsequent Kg 20ml 0.5-1.0 0.2-0.7 Blood glucose will need to be monitored

Answer 153

Wound Healing Processes at 10 Days Post-Laparotomy Wound healing is a complex biological process that occurs in several overlapping phases: hemostasis, inflammation, proliferation, and remodeling. By the tenth day following a laparotomy, the wound is typically in the proliferative phase of healing. During this phase, several key processes are actively occurring: Angiogenesis: This is the formation of new blood vessels from pre-existing ones. It is crucial for supplying nutrients and oxygen to the healing tissue. At 10 days post-surgery, angiogenesis is likely to be well underway as the body attempts to restore blood supply to the area. Synthesis of Collagen: Fibroblasts play a significant role in synthesizing collagen, which provides structural support to the wound. By this stage, collagen deposition is prominent as part of the body’s efforts to strengthen the newly formed tissue. Necrosis of Fibroblasts: This refers to cell death due to injury or lack of blood supply. In a healing wound at this stage, necrosis of fibroblasts would be less likely because these cells are essential for wound repair and are actively proliferating and synthesizing extracellular matrix components. Secretion of Matrix Metalloproteinases (MMPs) by Fibroblasts: MMPs are enzymes that degrade various components of the extracellular matrix and play a role in tissue remodeling. While their secretion can occur during wound healing, it is more prominent later in the remodeling phase rather than at 10 days post-surgery when fibroblast activity focuses on synthesis rather than degradation. Proliferation of Fibroblasts: This process involves an increase in fibroblast numbers as they migrate into the wound site and begin producing collagen and other extracellular matrix components necessary for repair. Given these considerations, we can analyze which process is least likely occurring at this stage: Angiogenesis is expected. Synthesis of collagen is expected. Proliferation of fibroblasts is expected. Secretion of MMPs may occur but not as prominently as other processes. Necrosis of fibroblasts would be atypical since they are vital for healing. Based on this analysis, necrosis of fibroblasts is least likely to be occurring in the wound at this stage because fibroblasts are actively involved in healing rather than undergoing necrosis. Answer: Necrosis of fibroblasts

Answer 154

To access the sub mandibular gland a transverse incision 3cm below the mandible should be made. Incisions located higher than this may damage the marginal mandibular branch of the facial nerve. Anterior triangle of the neck Boundaries Anterior border of the Sternocleidomastoid Lower border of mandible Anterior midline Sub triangles (divided by Digastric above and Omohyoid) Muscular triangle: Neck strap muscles Carotid triangle: Carotid sheath Submandibular Triangle (digastric) Contents of the anterior triangle Digastric triangle Submandibular gland Submandibular nodes Facial vessels Hypoglossal nerve Muscular triangle Strap muscles Jugular vein Carotid triangle Carotid sheath (Common carotid, vagus and internal jugular vein) Ansa cervicalis Nerve supply to digastric muscle Anterior: Mylohyoid nerve Posterior: Facial nerve

Answer 155

Adductor pollicis is innervated by the ulnar nerve. Medial two lumbricals innervated by the ulnar nerve. Median nerve The median nerve is formed by the union of a lateral and medial root respectively from the lateral (C5,6,7) and medial (C8 and T1) cords of the brachial plexus; the medial root passes anterior to the third part of the axillary artery. The nerve descends lateral to the brachial artery, crosses to its medial side (usually passing anterior to the artery). It passes deep to the bicipital aponeurosis and the median cubital vein at the elbow. It passes between the two heads of the pronator teres muscle, and runs on the deep surface of flexor digitorum superficialis (within its fascial sheath). Near the wrist it becomes superficial between the tendons of flexor digitorum superficialis and flexor carpi radialis, deep to palmaris longus tendon. It passes deep to the flexor retinaculum to enter the palm, but lies anterior to the long flexor tendons within the carpal tunnel. Branches Region Branch Upper arm No branches, although the nerve commonly communicates with the musculocutaneous nerve Forearm Pronator teres Pronator quadratus Flexor carpi radialis Palmaris longus Flexor digitorum superficialis Flexor pollicis longus Flexor digitorum profundus (only the radial half) Distal forearm Palmar cutaneous branch Hand (Motor) Motor supply (LOAF) Lateral 2 lumbricals Opponens pollicis Abductor pollicis brevis Flexor pollicis brevis Hand (Sensory) Over thumb and lateral 2 ½ fingers On the palmar aspect this projects proximally, on the dorsal aspect only the distal regions are innervated with the radial nerve providing the more proximal cutaneous innervation. Patterns of damage Damage at wrist e.g. carpal tunnel syndrome paralysis and wasting of thenar eminence muscles and opponens pollicis (ape hand deformity) sensory loss to palmar aspect of lateral (radial) 2 ½ fingers Damage at elbow, as above plus: unable to pronate forearm weak wrist flexion ulnar deviation of wrist Anterior interosseous nerve (branch of median nerve) leaves just below the elbow results in loss of pronation of forearm and weakness of long flexors of thumb and index finger

Answer 156

This is one variant of a below knee amputation. The Burgess flap is the other commonly practised approach. Amputations Amputations are indicated when the affected limb is one of the following: Dead non viable Deadly where it is posing a major threat to life Dead useless where it is viable but a prosthesis would be preferable Orthopaedic surgery Amputation is often undertaken as an option of last resort e.g. Limb salvage has failed and the limb is so non functional that mobility needs would be best met with prosthesis. Chronic fracture non union or significant limb shortening following trauma would fit into this category. Occasionally following major trauma a primary amputation is preferable. This would be the case in an open fracture with major distal neurovascular compromise and other more life threatening injuries are present. Vascular surgery The first two categories are the most prevalent. Diabetic foot sepsis is often a major cause of sepsis which can spread rapidly in the presence of established peripheral vascular disease. As a general rule the main issue in vascular surgery is to optimise vascular inflow prior to surgery. The more distal the planned amputation is to be, the more important this rule becomes. In other situations there has been something such as an embolic event that has not been revascularised in time. In this case the limb shows fixed mottling and an amputation will be needed. Types of amputations As the vast majority of commonly performed amputations affect the lower limbs these will be covered here. The main categories of amputations are: Pelvic disarticulation (hindquarter) Above knee amputation Gritti Stokes (through knee amputation) Below knee amputation (using either Skew or Burgess flaps) Syme's amputation (through ankle) Amputations of mid foot and digits Choosing a level of amputation depends on: The disease process being treated Desired functional outcome Co-morbidities of the patient Above knee amputations Quick to perform Heal reliably Patients regain their general health quickly For this benefit, a functional price has to be paid and many patients over the age of 70 will never walk on an above knee prosthesis. Above knee amputations use equal anterior-posterior flaps Below knee amputations Technically more challenging to perform Heal less reliably than their above knee counterparts. However, many more patients are able to walk using a below knee prosthesis. In below knee amputations the two main flaps are Skew flaps or the Burgess long posterior flap. Skew flaps result in a less bulky limb that is easier to attach a prosthesis to. It is worth remembering that whilst it may be technically feasible to offer a below knee amputation there may be circumstances where an above knee option is preferable. For example, in fixed flexion deformities of the lower limb, little functional benefit would be gained from below knee amputation surgery.

Answer 157

A sudden anemia and a LOW reticulocyte count indicates parvovirus. Acute sequestration and haemolysis causes a high reticulocyte count. There is no clinical indication to suspect a bleed, therefore you can advise the F1 not to panic and to speak to the haematologists! Sickle cell anaemia Autosomal recessive Single base mutation Deoxygenated cells become sickle in shape Causes: short red cell survival, obstruction of microvessels and infarction Sickling is precipitated by: dehydration, infection, hypoxia Manifest at 6 months age Africans, Middle East, Indian Diagnosis: Hb electrophoresis Sickle crises Bone pain Pleuritic chest pain: acute sickle chest syndrome commonest cause of death CVA, seizures Papillary necrosis Splenic infarcts Priapism Hepatic pain Hb does not fall during a crisis, unless there is Aplasia: parvovirus Acute sequestration Haemolysis Long-term complications Infections: Streptococcus pnemoniae Chronic leg ulcers Gallstones: haemolysis Aseptic necrosis of bone Chronic renal disease Retinal detachment, proliferative retinopathy Surgical complications Bowel ischaemia Cholecystitis Avascular necrosis Management Supportive Hydroxyurea Repeated transfusions pre operatively Exchange transfusion in emergencies Sickle cell trait Heterozygous state Asymptomatic Symptoms associated with extreme situations ie anaesthesia complications Protective against Plasmodium falciparum

Answer 158

A- Cryoprecipitate - Blood product made from plasma Usually transfused as 6 unit pool Indications include massive haemorrhage and uncontrolled bleeding due to haemophilia Composition Agent Quantity Factor VIII 100IU Fibrinogen 250mg von Willebrand factor Variable Factor XIII Variable

Answer 159

All local anaesthetics have a chemical bond linking an amine to either an amide or an ester. Most local anaesthetics are of the amino- amide types, these have a more favorable side effect profile and are more stable in solution. Procaine and benzocaine have amino - ester groups, these are metabolised by pseudocholinesterases. Local anaesthetic agents Lidocaine An amide Local anaesthetic and a less commonly used antiarrhythmic (affects Na channels in the axon) Hepatic metabolism, protein bound, renally excreted Toxicity: due to IV or excess administration. Increased risk if liver dysfunction or low protein states. Note acidosis causes lidocaine to detach from protein binding. Drug interactions: Beta blockers, ciprofloxacin, phenytoin Features of toxicity: Initial CNS over activity then depression as lidocaine initially blocks inhibitory pathways then blocks both inhibitory and activating pathways. Cardiac arrhythmias. Increased doses may be used when combined with adrenaline to limit systemic absorption. Cocaine Pure cocaine is a salt, usually cocaine hydrochloride. It is supplied for local anaesthetic purposes as a paste. It is supplied for clinical use in concentrations of 4 and 10%. It may be applied topically to the nasal mucosa. It has a rapid onset of action and has the additional advantage of causing marked vasoconstriction. It is lipophillic and will readily cross the blood brain barrier. Its systemic effects also include cardiac arrhythmias and tachycardia. Apart from its limited use in ENT surgery it is otherwise used rarely in mainstream surgical practice. Bupivacaine Bupivacaine binds to the intracellular portion of sodium channels and blocks sodium influx into nerve cells, which prevents depolarization. It has a much longer duration of action than lignocaine and this is of use in that it may be used for topical wound infiltration at the conclusion of surgical procedures with long duration analgesic effect. It is cardiotoxic and is therefore contra indicated in regional blockage in case the tourniquet fails. Levobupivacaine (Chirocaine) is less cardiotoxic and causes less vasodilation. Prilocaine Similar mechanism of action to other local anaesthetic agents. However, it is far less cardiotoxic and is therefore the agent of choice for intravenous regional anaesthesia e.g. Biers Block. All local anaesthetic agents dissociate in tissues and this contributes to their therapeutic effect. The dissociation constant shifts in tissues that are acidic e.g. where an abscess is present, and this reduces the efficacy. Doses of local anaesthetics Agent Dose plain Dose with adrenaline Lignocaine 3mg/Kg 7mg/Kg Bupivacaine 2mg/Kg 2mg/Kg Prilocaine 6mg/Kg 9mg/Kg These are a guide only as actual doses depend on site of administration, tissue vascularity and co-morbidities. Maximum total local anaesthetic doses Lignocaine 1% plain - 3mg/ Kg - 200mg (20ml) Lignocaine 1% with 1 in 200,000 adrenaline - 7mg/Kg - 500mg (50ml) Bupivacaine 0.5% - 2mg/kg- 150mg (30ml) Maximum doses are based on ideal body weight Effects of adrenaline Adrenaline may be added to local anaesthetic drugs. It prolongs the duration of action at the site of injection and permits usage of higher doses (see above). It is contra indicated in patients taking MAOI's or tricyclic antidepressants. The toxicity of bupivacaine is related to protein binding and addition of adrenaline to this drug does not permit increases in the total dose of bupivacaine, in contrast to the situation with lignocaine. References An excellent review is provided by: French J and Sharp L. Local Anaesthetics. Ann R Coll Surg Engl 2012; 94: 76-80.

Answer 160

Peroneus tertius is innervated by the deep peroneal nerve. Tibial nerve Begins at the upper border of the popliteal fossa and is a branch of the sciatic nerve. Root values: L4, L5, S1, S2, S3 Muscles innervated Popliteus Gastrocnemius Soleus Plantaris Tibialis posterior Flexor hallucis longus Flexor digitorum brevis and longus Terminates by dividing into the medial and lateral plantar nerves.

Answer 161

Post transplant complications CMV: 4 weeks to 6 months post transplant EBV: post transplant lymphoproliferative disease. > 6 months post transplant Post transplant lymphoproliferative disorder is most commonly associated with Epstein-Barr virus. It typically occurs 6 months post transplant and is associated with high dose immunosupressant therapy. Remember cytomegalovirus presents within the first 4 weeks to 6 months post transplant. Renal transplant:HLA typing and graft failure The human leucocyte antigen (HLA) system is the name given to the major histocompatibility complex (MHC) in humans. It is coded for on chromosome 6. Some basic points on the HLA system Class 1 antigens include A, B and C. Class 2 antigens include DP,DQ and DR When HLA matching for a renal transplant the relative importance of the HLA antigens are as follows DR > B > A Graft survival 1 year = 90%, 10 years = 60% for cadaveric transplants 1 year = 95%, 10 years = 70% for living-donor transplants Post-op problems ATN of graft Vascular thrombosis Urine leakage UTI Hyperacute acute rejection Due to antibodies against donor HLA type 1 antigens Rarely seen due to HLA matching Acute graft failure (< 6 months) Usually due to mismatched HLA Other causes include cytomegalovirus infection Management: give steroids, if resistant use monoclonal antibodies Causes of chronic graft failure (> 6 months) Chronic allograft nephropathy Ureteric obstruction Recurrence of original renal disease (MCGN > IgA > FSGS)

Answer 162

The transverse cervical nerve lies within the posterior triangle (the transverse cervical nerve divides into superior and inferior branches of the anterior margin of SCM). The anterior jugular vein is formed in the submental region and descends in the superficial fascia near the median plane. It passes inferior to enter the suprasternal space, it is linked to the contralateral anterior jugular vein by the jugular venous arch. Anterior triangle of the neck Boundaries Anterior border of the Sternocleidomastoid Lower border of mandible Anterior midline Sub triangles (divided by Digastric above and Omohyoid) Muscular triangle: Neck strap muscles Carotid triangle: Carotid sheath Submandibular Triangle (digastric) Contents of the anterior triangle Digastric triangle Submandibular gland Submandibular nodes Facial vessels Hypoglossal nerve Muscular triangle Strap muscles Jugular vein Carotid triangle Carotid sheath (Common carotid, vagus and internal jugular vein) Ansa cervicalis Nerve supply to digastric muscle Anterior: Mylohyoid nerve Posterior: Facial nerve

Answer 163

The thyrocervical trunk is a branch of the subclavian artery. It arises from the first part between the subclavian artery and the inner border of scalenus anterior. It branches off the subclavian distal to the vertebral artery. Root of the neck Thoracic Outlet Where the subclavian artery and vein and the brachial plexus exit the thorax and enter the arm. They pass over the 1st rib and under the clavicle. The subclavian vein is the most anterior structure and is immediately anterior to scalenus anterior and its attachment to the first rib. Then subclavian artery passes between the anterior and middle scalene muscles. At the level of the first rib, the lower cervical nerve roots combine to form the 3 trunks of the brachial plexus. The lowest trunk is formed by the union of C8 and T1, and this trunk lies directly posterior to the artery and is in contact with the superior surface of the first rib. Thoracic outlet obstruction causes neurovascular compromise.

Answer 164

When a person, such as a 22-year-old man, injures his thumb by punching an opponent, the most likely type of fracture to occur is a **Bennett's fracture**. This is a fracture at the base of the thumb metacarpal involving the carpometacarpal (CMC) joint, resulting in a clean break with a significant piece of bone broken off. This type of fracture is common in scenarios involving direct trauma to the thumb, such as punching. Eponymous fractures Colles' fracture (dinner fork deformity) Fall onto extended outstretched hand Classical Colles' fractures have the following 3 features: 1. Transverse fracture of the radius 2. 1 inch proximal to the radio-carpal joint 3. Dorsal displacement and angulation Smith's fracture (reverse Colles' fracture) Volar angulation of distal radius fragment (Garden spade deformity) Caused by falling backwards onto the palm of an outstretched hand or falling with wrists flexed Bennett's fracture Intra-articular fracture of the first carpometacarpal joint Impact on flexed metacarpal, caused by fist fights X-ray: triangular fragment at ulnar base of metacarpal Monteggia's fracture Dislocation of the proximal radioulnar joint in association with an ulna fracture Fall on outstretched hand with forced pronation Needs prompt diagnosis to avoid disability Galeazzi fracture Radial shaft fracture with associated dislocation of the distal radioulnar joint Direct blow Pott's fracture Bimalleolar ankle fracture Forced foot eversion Barton's fracture Distal radius fracture (Colles'/Smith's) with associated radiocarpal dislocation Fall onto extended and pronated wrist Involvement of the joint is a defining feature Holstein Lewis Fracture A HolsteinLewis fracture is a fracture of the distal third of the humerus resulting in entrapment of the radial nerve. The radial nerve is one of the major nerves of the upper limb. It innervates all of the muscles in the extensor compartments of the arm. Conservative treatment includes reduction and use of a functional brace Vascular injury may require open surgery

Answer 165

The phrenic nerve is the most anteriorly located structure in the lung root. The vagus nerve lies most posteriorly. Lung anatomy The right lung is composed of 3 lobes divided by the oblique and transverse fissures. The left lung has two lobes divided by the oblique fissure.The apex of both lungs is approximately 4cm superior to the sterno-costal joint of the first rib. Immediately below this is a sulcus created by the subclavian artery. Peripheral contact points of the lung Base: diaphragm Costal surface: corresponds to the cavity of the chest Mediastinal surface: Contacts the mediastinal pleura. Has the cardiac impression. Above and behind this concavity is a triangular depression named the hilum, where the structures which form the root of the lung enter and leave the viscus. These structures are invested by pleura, which, below the hilum and behind the pericardial impression, forms the pulmonary ligament Right lung Above the hilum is the azygos vein; Superior to this is the groove for the superior vena cava and right innominate vein; behind this, and nearer the apex, is a furrow for the innominate artery. Behind the hilum and the attachment of the pulmonary ligament is a vertical groove for the oesophagus; In front and to the right of the lower part of the oesophageal groove is a deep concavity for the extrapericardiac portion of the inferior vena cava. The root of the right lung lies behind the superior vena cava and the right atrium, and below the azygos vein. The right main bronchus is shorter, wider and more vertical than the left main bronchus and therefore the route taken by most foreign bodies. Left lung Above the hilum is the furrow produced by the aortic arch, and then superiorly the groove accommodating the left subclavian artery; Behind the hilum and pulmonary ligament is a vertical groove produced by the descending aorta, and in front of this, near the base of the lung, is the lower part of the oesophagus. The root of the left lung passes under the aortic arch and in front of the descending aorta. Inferior borders of both lungs 6th rib in mid clavicular line 8th rib in mid axillary line 10th rib posteriorly The pleura runs two ribs lower than the corresponding lung level. Bronchopulmonary segments Segment number Right lung Left lung 1 Apical Apical 2 Posterior Posterior 3 Anterior Anterior 4 Lateral Superior lingular 5 Medial Inferior lingular 6 Superior (apical) Superior (apical) 7 Medial basal Medial basal 8 Anterior basal Anterior basal 9 Lateral basal Lateral basal 10 Posterior basal Posterior basal

Answer 166

The recurrent laryngeal nerve may be injured at this site during ligation of the inferior thyroid artery. Thyroid gland Right and left lobes connected by isthmus Surrounded by sheath from pretracheal layer of deep fascia Apex: Lamina of thyroid cartilage Base: 4th-5th tracheal ring Pyramidal lobe: from isthmus May be attached to foramen caecum at the base of the tongue Relations Anteromedially Sternothyroid Superior belly of omohyoid Sternohyoid Anterior aspect of sternocleidomastoid Posterolaterally Carotid sheath Medially Larynx Trachea Pharynx Oesophagus Cricothyroid muscle External laryngeal nerve (near superior thyroid artery) Recurrent laryngeal nerve (near inferior thyroid artery) Posterior Parathyroid glands Anastomosis of superior and inferior thyroid arteries Isthmus Anteriorly: Sternothyroids, sternohyoids, anterior jugular veins Posteriorly: 2nd, 3rd, 4th tracheal rings (attached via Ligament of Berry) Blood Supply Arterial Superior thyroid artery (1st branch of external carotid) Inferior thyroid artery (from thyrocervical trunk) Thyroidea ima (in 10% of population -from brachiocephalic artery or aorta) Venous Superior and middle thyroid veins - into the IJV Inferior thyroid vein - into the brachiocephalic veins

Answer 167

The application of cold compresses is indicated in doxorubicin extravasation. Warm compresses increase the risk of doxorubicin ulceration. Hyaluronidase is indicated in the extravasation of contrast media, TPN and vinca alkaloids. However, if administered following doxorubicin extravasation it will dramatically worsen the situation and is contra indicated. Up to 50% of those sustaining severe injuries will require delayed surgical reconstruction. Extravasation injury Chemotherapy may be complicated by extravasation reactions in up to 6% of cases. The following chemotherapy agents are recognised causes of extravasation reactions; doxorubicin, vincristine, vinblastine, cisplatin, mitomycin and mithramycin. Up to 30% of extravasation reactions may be complicated by the development of ulceration. When an extravasation reaction is suspected, the infusion should be stopped and the infusing device aspirated. The extremity should be elevated. As a general rule cold compresses have been shown to reduce the incidence of subsequent ulceration with doxorubicin. Warm compresses have been found to be beneficial in extravasation of vinca alkaloids. Dimethylsulfoxide may be infused in some cases, ideally within 5 hours of the event occurring. No conclusive evidence exists to support the use of corticosteroids or sodium bicarbonate for extravasation injuries. Extravasation of total parenteral nutrition solutions is usually managed by the local administration of hyaluronidase to the infusion site.

Answer 168

Analysis of Statements Regarding Squamous Cell Carcinoma To determine which statement is false regarding the squamous cell carcinoma (SCC) diagnosed in the 68-year-old man, we will analyze each statement based on current medical knowledge and guidelines. In this particular case margins of at least 6mm are required: For SCC, especially those that are larger or have certain risk factors, surgical excision with clear margins is critical to minimize the risk of recurrence. The recommended margin for low-risk SCCs can be around 4-5mm, but for high-risk lesions (which may include those that are larger than 2cm or deeper than 4mm), a margin of at least 6mm is often recommended. Given that this lesion measures 25mm in diameter and is 4mm deep, it would be prudent to require a margin of at least 6mm. Therefore, this statement is true. Use of cryosurgery to treat this patient’s lesion would have been unsafe: Cryosurgery can be used for superficial skin cancers; however, it is generally not recommended for invasive SCCs due to the potential for incomplete treatment and local recurrence. Given the size and depth of this lesion (25mm and 4mm respectively), using cryosurgery would indeed be considered unsafe as it may not adequately address the invasive nature of the cancer. Thus, this statement is true. Use of radiotherapy to treat this lesion would have been unsafe: Radiotherapy can be an effective treatment modality for SCC, particularly in cases where surgery is not feasible or when there are concerns about surgical margins. It can also be used post-operatively if there are positive margins or other high-risk features present. Therefore, stating that radiotherapy would be unsafe in treating this lesion does not align with current practices; thus, this statement is false. This patient’s local recurrence rate may approach 15%: Local recurrence rates for SCC can vary widely based on several factors including tumor size, depth, location, and adequacy of surgical margins. For high-risk lesions such as large or deeply invasive SCCs, local recurrence rates can indeed approach or exceed 15%. This aligns with clinical data suggesting higher recurrence rates in such cases; therefore, this statement is true. The disease usually spreads via lymphatics: SCC typically spreads through lymphatic channels rather than hematogenous routes (bloodstream). This characteristic behavior is well-documented in medical literature regarding squamous cell carcinoma; hence, this statement is also true. Based on the analysis above: The false statement among those provided regarding the management and characteristics of squamous cell carcinoma in this patient scenario is: Use of radiotherapy to treat this lesion would have been unsafe Poor prognostic factors in SCC: Size >20mm (local recurrence rate of up to 15%) Depth greater than 4mm (risk of metastasis up to 30%) This man has an SCC with significant risk of metastasis. Although cryotherapy may be used to treat SCC it would be most unsafe in this setting as the lesion extends deeply. However, radiotherapy is a safe treatment modality for SCC and may be used in selected cases. It is unwise to use radiotherapy in areas prone to radionecrosis e.g. the nose. Squamous cell carcinoma of the skin Second most common skin malignancy Derived from epidermal keratinocytes Commonest in fair skinned individuals in sun exposed sites May occur in perianal and genital skin especially in association with Human Papilloma Virus 16 and 18 infections. Groups at high risk Renal transplant and on immunosuppression Individuals with HIV Those who have received psoralen UVA therapy Chronic wounds (Marjolins ulcer) Xeroderma pigmentosum Oculocutaneous albinism Prognosis Good Prognosis Poor prognosis Well differentiated tumours Poorly differentiated tumours <20mm diameter >20mm in diameter <2mm deep >4mm deep No associated diseases Immunosupression for whatever reason Treatment Surgical excision with 4mm margins if lesion <20mm in diameter. If tumour >20mm then margins should be 6mm.

Answer 169

Clinical Presentation and Context In this scenario, we have a 20-year-old man with a severe head injury, as evidenced by the CT scan showing multiple intracerebral bleeds. The clinical signs include dilated pupils that react sluggishly to light, bradycardia (heart rate of 50 beats/minute), hypertension (blood pressure of 170/110 mmHg), and a controlled respiratory rate set at 10 breaths/minute due to intubation and ventilation. Understanding the Physiological Responses Intracranial Pressure (ICP): Severe head injuries often lead to increased intracranial pressure due to swelling or bleeding within the cranial cavity. This increase in ICP can stimulate various physiological responses. Sympathetic Nervous System Activation: In response to elevated ICP, the body may activate the sympathetic nervous system as a compensatory mechanism. This activation can lead to increased systemic vascular resistance and subsequent hypertension. Cushing’s Reflex: The combination of bradycardia and hypertension is indicative of Cushing’s reflex, which is a physiological response to increased ICP. This reflex involves: Increased blood pressure due to sympathetic stimulation. Bradycardia as a result of baroreceptor reflexes responding to high blood pressure. Baroreceptor Response: While baroreceptors in the carotid arteries and aorta respond to changes in blood pressure, in this case, the primary driver for the observed hypertension is likely related to increased intracranial pressure rather than direct stimulation from baroreceptors alone. Other Factors Considered: Cortisol Stimulation: While cortisol can influence blood pressure regulation, it is not the primary factor in acute head trauma scenarios. Renin-Angiotensin Stimulation: This system typically responds to low blood volume or low blood pressure situations rather than isolated increases in ICP. Sympathetic Stimulation Related to Blood Loss: There is no indication of significant blood loss in this scenario; thus, this option is less relevant. Given these considerations, the most plausible explanation for the rising blood pressure in this patient is: Sympathetic stimulation related to increased intracranial pressure This conclusion aligns with established medical knowledge regarding responses following severe head injuries and their effects on cardiovascular dynamics. The changes seen are the result of raised ICP, its rare for head injuries to cause sufficient blood loss to affect the circulating volume. Cushing reflex When intra cranial pressure exceeds mean arterial pressure, compression of cerebral arterioles occurs. This results in cerebral ischaemia. Increases in ICP results in stepwise activation of the sympathetic nervous system initially. This raises peripheral vascular resistance and results in hypertension. Cardiac output is also increased. These haemodynamic changes are detected by aortic arch baroreceptors and this results in activation of the parasympathetic nervous system. These parasympathetic effects comprise the second stage of the Cushing reflex. The Cushing reflex is a serious development that indicates imminent coning or other terminal events if not resolved quickly.

Answer 170

Benzodiazepine overdose with marked suppression of respiratory activity should be managed with IV flumazenil. Midazolam Midazolam is a short acting benzodiazepine. It is usually administered intravenously, when administered orally, dosing is less reliable. It is eliminated via the cytochrome P450 pathway in the liver. It is often used for procedural related sedation purposes. It is generally administered in doses of 2-5mg for this purpose. It is often given in combination with a short acting opiate such as fentanyl for analgesic purposes. One of the main reasons that midazolam is preferred for procedural related sedation is due to a degree of amnesia that can accompany it. If administered in excess, most patients can be managed with simple airway support measures an monitoring. However, if there is significant respiratory compromise, it can be reversed with the agent flumazenil which is a selective GABA receptor antagonist.

Answer 171

Bowel obstruction due to RECTAL cancer should be treated by loop colostomy. Bowel obstruction due to obstructing left sided COLON cancer is usually treated by resection of the primary lesion and formation of colostomy. This patient should be defunctioned, definitive surgery should wait until staging is completed. A loop ileostomy will not satisfactorily decompress an acutely obstructed colon. Low rectal cancers that are obstructed should not usually be primarily resected. The obstructed colon that would be used for anastomosis would carry a high risk of anastomotic dehiscence. In addition, as this is an emergency presentation, staging may not be completed, an attempted resection may therefore compromise the circumferential resection margin, with an associated risk of local recurrence. Colorectal cancer treatment Patients diagnosed as having colorectal cancer should be completely staged using CT of the chest/ abdomen and pelvis. Their entire colon should have been evaluated with colonoscopy or CT colonography. Patients whose tumours lie below the peritoneal reflection should have their mesorectum evaluated with MRI. Once their staging is complete patients should be discussed within a dedicated colorectal MDT meeting and a treatment plan formulated. Treatment of colonic cancer Cancer of the colon is nearly always treated with surgery. Stents, surgical bypass and diversion stomas may all be used as palliative adjuncts. Resectional surgery is the only option for cure in patients with colon cancer. The procedure is tailored to the patient and the tumour location. The lymphatic drainage of the colon follows the arterial supply and therefore most resections are tailored around the resection of particular lymphatic chains (e.g. ileo-colic pedicle for right sided tumours). Some patients may have confounding factors that will govern the choice of procedure, for example a tumour in a patient from a HNPCC family may be better served with a panproctocolectomy rather than segmental resection. Following resection the decision has to be made regarding restoration of continuity. For an anastomosis to heal the key technical factors include; adequate blood supply, mucosal apposition and no tissue tension. Surrounding sepsis, unstable patients and inexperienced surgeons may compromise these key principles and in such circumstances it may be safer to construct an end stoma rather than attempting an anastomosis. When a colonic cancer presents with an obstructing lesion; the options are to either stent it or resect. In modern practice it is unusual to simply defunction a colonic tumour with a proximal loop stoma. This differs from the situation in the rectum (see below). Following resection patients with risk factors for disease recurrence are usually offered chemotherapy, a combination of 5FU and oxaliplatin is common. Rectal cancer The management of rectal cancer is slightly different to that of colonic cancer. This reflects the rectum's anatomical location and the challenges posed as a result. Tumours located in the rectum can be surgically resected with either an anterior resection or an abdomino - perineal resection. The technical aspects governing the choice between these two procedures can be complex to appreciate and the main point to appreciate for the MRCS is that involvement of the sphincter complex or very low tumours require APER. In the rectum a 2cm distal clearance margin is required and this may also impact on the procedure chosen. In addition to excision of the rectal tube an integral part of the procedure is a meticulous dissection of the mesorectal fat and lymph nodes (total mesorectal excision/ TME). In rectal cancer surgery invovlement of the cirumferential resection margin carries a high risk of disease recurrence. Because the rectum is an extraperitoneal structure (until you remove it that is!) it is possible to irradiate it, something which cannot be offered for colonic tumours. This has a major impact in rectal cancer treatment and many patients will be offered neoadjuvent radiotherapy (both long and short course) prior to resectional surgery. Patients with T1, 2 and 3 /N0 disease on imaging do not require irradiation and should proceed straight to surgery. Patients with T4 disease will typically have long course chemo radiotherapy. Patients presenting with large bowel obstruction from rectal cancer should not undergo resectional surgery without staging as primary treatment (very different from colonic cancer). This is because rectal surgery is more technically demanding, the anastomotic leak rate is higher and the danger of a positive resection margin in an unstaged patient is high. Therefore patients with obstructing rectal cancer should have a defunctioning loop colostomy. Summary of procedures The operations for cancer are segmental resections based on blood supply and lymphatic drainage. These commonly performed procedures are core knowledge for the MRCS and should be understood. Site of cancer Type of resection Anastomosis Risk of leak Right colon Right hemicolectomy Ileo-colic Low <5% Transverse Extended right hemicolectomy Ileo-colic Low <5% Splenic flexure Extended right hemicolectomy Ileo-colic Low <5% Splenic flexure Left hemicolectomy Colo-colon 2-5% Left colon Left hemicolectomy Colo-colon 2-5% Sigmoid colon High anterior resection Colo-rectal 5% Upper rectum Anterior resection (TME) Colo-rectal 5% Low rectum Anterior resection (Low TME) Colo-rectal (+/- Defunctioning stoma) 10% Anal verge Abdomino-perineal excision of colon and rectum None n/a In the emergency setting, where the bowel has perforated, the risk of an anastomotic breakdown is much greater, particularly when the anastomosis is colon-colon. In this situation, an end colostomy is often safer and can be reversed later. When resection of the sigmoid colon is performed and an end colostomy is fashioned the operation is referred to as a Hartmans procedure. Whilst left sided resections are more risky, ileo-colic anastomoses are relatively safe even in the emergency setting and do not need to be defunctioned. References A review of the diagnosis and management of colorectal cancer and a summary of the UK National Institute of Clinical Excellence guidelines is provided in: Poston G, et al . Diagnosis and management of colorectal cancer: summary of NICE guidance. BMJ 2011: 343: d 6751.

Answer 172

Unless there are concerns about implant rupture, the imaging of a breast lump in a young patient with implants would be USS initially. If this is not conclusive then MRI should be performed. Remember that MRI is the modality of choice where an implant related complication is suspected or there are concerns about malignant or pre malignant changes and none of these apply here. Breast imaging Breast imaging is undertaken with a combination of USS and mammography in most women presenting with a palpable lump. In younger patients, the denser breasts encountered in this group may make mammography less informative. In women who present with breast implants with a palpable lump, the imaging of choice remains the same. However, specialized imaging techniques may be needed to obtain optimal mammographic views. Where there are specific concerns about a breast implant, rather than a lump, the imaging modality of choice is MRI scanning. MRI scanning may be beneficial in screening younger patients with a family history and also in patients with lobular cancers who are being considered for breast conserving surgery.

Answer 173

Answer: Delayed hypersensitivity reaction against bacteria Pathogenicity of the Tubercle Bacillus The pathogenicity of the tubercle bacillus, scientifically known as Mycobacterium tuberculosis, is a complex process that involves several mechanisms. To determine which option best describes the primary cause of its pathogenicity, we will analyze each provided choice in detail. Necrosis caused by expanding granulomas: Granulomas are organized structures formed in response to chronic inflammation, typically seen in infections like tuberculosis. They consist of macrophages, lymphocytes, and other immune cells that attempt to contain the infection. While necrosis can occur within granulomas due to cell death and tissue damage, it is not the primary mechanism through which M. tuberculosis exerts its pathogenic effects. Ability to multiply within fibroblasts: Fibroblasts are connective tissue cells that play a role in wound healing and tissue repair. However, M. tuberculosis primarily resides and replicates within macrophages rather than fibroblasts. The ability to survive and multiply inside macrophages is crucial for its pathogenicity but does not specifically highlight fibroblasts as a significant factor. Delayed hypersensitivity reaction against bacteria: The immune response to M. tuberculosis includes delayed-type hypersensitivity (DTH), which is mediated by T cells and leads to the formation of granulomas. This immune response is an important aspect of how the body attempts to control the infection; however, it is more a consequence of infection rather than a direct cause of pathogenicity. Effect of antibody response: Antibodies play a role in the immune response against many pathogens; however, M. tuberculosis has evolved mechanisms to evade antibody-mediated responses effectively. The bacterium’s cell wall contains mycolic acids that protect it from being effectively targeted by antibodies. Direct toxic effect on host cells: While M. tuberculosis does not produce traditional toxins like some other bacteria, it can induce cytotoxic effects indirectly through immune-mediated mechanisms and inflammation caused by its presence in host tissues. After analyzing these options, it becomes clear that while all these factors contribute to the overall disease process associated with tuberculosis, none directly encapsulate the primary mechanism behind the pathogenicity of M. tuberculosis. However, if we consider how this organism survives and thrives within host tissues despite an immune response aimed at eliminating it, we find that: The most relevant factor among those listed would be related to its ability to evade destruction within macrophages (not explicitly mentioned but implied) leading to chronic infection and delayed hypersensitivity reactions as part of the immune response. Thus, considering all aspects discussed: The pathogenicity of the tubercle bacillus is primarily due to its ability to multiply within host cells (macrophages) and elicit a delayed hypersensitivity reaction against itself, but since “ability to multiply within fibroblasts” was one option presented: Mycobacteria stimulate a specific T cell response of cell mediated immunity. This is effective in reducing the infection, the delayed hypersensitivity also damages tissues. Necrosis occurs in TB but is usually within the granuloma. Tuberculosis pathology Is a form of primary chronic inflammation, caused by the inability of macrophages to kill the Mycobacterium tuberculosis. The macrophages often migrate to regional lymph nodes, the lung lesion plus affected lymph nodes is referred to as a Ghon complex. This leads to the formation of a granuloma which is a collection of epithelioid histiocytes. There is the presence of caseous necrosis in the centre. The inflammatory response is mediated by a type 4 hypersensitivity reaction. In healthy individuals the disease may be contained, in the immunocompromised disseminated (miliary TB) may occur. Diagnosis Waxy membrane of mycobacteria prevents binding with normal stains. Ziehl - Neelsen staining is typically used. Culture based methods take far longer.

Answer 174

Unlike most anaesthetic agents ketamine does not cause myocardial or marked respiratory depression. It is not associated with the adrenal suppression that may occur with etomidate. It is however, associated with a state of dissociative anaesthesia which patients may find distressing. Anaesthetic agents The table below summarises some of the more commonly used IV induction agents Agent Specific features Propofol Rapid onset of anaesthesia Pain on IV injection Rapidly metabolised with little accumulation of metabolites Proven anti emetic properties Moderate myocardial depression Widely used especially for maintaining sedation on ITU, total IV anaesthesia and for daycase surgery Sodium thiopentone Extremely rapid onset of action making it the agent of choice for rapid sequence of induction Marked myocardial depression may occur Metabolites build up quickly Unsuitable for maintenance infusion Little analgesic effects Ketamine May be used for induction of anaesthesia Has moderate to strong analgesic properties Produces little myocardial depression making it a suitable agent for anaesthesia in those who are haemodynamically unstable May induce state of dissociative anaesthesia resulting in nightmares Etomidate Has favorable cardiac safety profile with very little haemodynamic instability No analgesic properties Unsuitable for maintaining sedation as prolonged (and even brief) use may result in adrenal suppression Post operative vomiting is common

Answer 175

The azygos vein is routinely divided during an oesophagectomy to allow mobilisation. It arches anteriorly to insert into the SVC on the right hand side. Treatment of oesophageal cancer - In general resections are not offered to those patients with distant metastasis, and usually not to those with N2 disease. Local nodal involvement is not in itself a contra indication to resection. Surgical resection is the mainstay of treatment. Neoadjuvent chemotherapy is given in most cases prior to surgery. In situ disease may be managed by endoscopic mucosal resection, although this is still debated. In patients with lower third lesions an Ivor - Lewis type procedure is most commonly performed. Very distal tumours may be suitable to a transhiatal procedure. Which is an attractive option as the penetration of two visceral cavities required for an Ivor- Lewis type procedure increases the morbidity considerably. More proximal lesions will require a total oesphagectomy (Mckeown type) with anastomosis to the cervical oesophagus. Patients with unresectable disease may derive benefit from local ablative procedures, palliative chemotherapy or stent insertion. Operative details of Ivor- Lewis procedure Combined laparotomy and right thoracotomy Indication Lower and middle third oesophageal tumours Preparation Staging with a combination of CT chest abdomen and pelvis- if no metastatic disease detected then patients will undergo a staging laparoscopy to detect peritoneal disease. If both these modalities are negative then patients will finally undergo a PET CT scan to detect occult metastatic disease. Only in those whom no evidence of advanced disease is detected will proceed to resection. Patients receive a GA, double lumen endotracheal tube to allow for lung deflation, CVP and arterial monitoring. Procedure A rooftop incision is made to access the stomach and duodenum. Laparotomy To mobilize the stomach The greater omentum is incised away from its attachment to the right gastroepiploic vessels along the greater curvature of the stomach. Then the short gastric vessels are ligated and detached from the greater curvature from the spleen. The lesser omentum is incised, preserving the right gastric artery. The retroperitoneal attachments of the duodenum in its second and third portions are incised, allowing the pylorus to reach the oesophageal hiatus. Some surgeons perform a pyloroplasty at this point to facilitate gastric emptying. The left gastric vessels are then ligated, avoiding any injury to the common hepatic or splenic arteries. Care must be taken to avoid inadvertently devascularising the liver owing to variations in anatomy. Right Thoracotomy Oesophageal resection and oesophagogastric anastomosis Through 5th intercostal space Dissection performed 10cm above the tumour This may involve transection of the azygos vein. The oesophagus is then removed with the stomach creating a gastric tube. An anastomosis is created. The chest is closed with underwater seal drainage and tube drains to the abdominal cavity. Post operatively Patients will typically recover in ITU initially. A nasogastric tube will have been inserted intraoperatively and must remain in place during the early phases of recovery. Post operatively these patients are at relatively high risk of developing complications: * Atelectasis- due to the effects of thoracotomy and lung collapse * Anastomotic leakage. The risk is relatively high owing to the presence of a relatively devascularised stomach. Often the only blood supply is from the gastroepiploic artery as all others will have been divided. If a leak does occur then many will attempt to manage conservatively with prolonged nasogastric tube drainage and TPN. The reality is that up to 50% of patients developing an anastomotic leak will not survive to discharge. * Delayed gastric emptying (may be avoided by performing a pyloroplasty).

Answer 176

99% of males with cystic fibrosis will have absent vas. Underlying Disease Association in a 28-Year-Old Man with Recurrent Chest Infections and No Palpable Vas Deferens To determine the most likely underlying disease association for the clinical scenario presented, we need to analyze the symptoms and their implications step by step. Clinical Features Recurrent Chest Infections: This symptom suggests an underlying issue with respiratory function or immune response. In particular, recurrent infections can be associated with conditions that affect mucous production or ciliary function. No Palpable Vas Deferens: The absence of the vas deferens is a significant finding. This condition is known as congenital bilateral absence of the vas deferens (CBAVD), which is commonly associated with certain genetic disorders. Testes Located Within the Scrotum: The presence of both testes in the scrotum indicates that there is no issue with testicular descent, which rules out some conditions like cryptorchidism. Differential Diagnosis Now let’s evaluate each of the potential associations provided: Klinefelter Syndrome: This genetic condition (47,XXY) typically presents with hypogonadism, gynecomastia, and infertility but does not specifically correlate with recurrent chest infections or absent vas deferens. Kallmann Syndrome: This condition involves hypogonadotropic hypogonadism and anosmia (loss of smell). While it can lead to infertility due to low testosterone levels, it does not typically present with recurrent chest infections or absent vas deferens. Cystic Fibrosis: Cystic fibrosis is a genetic disorder caused by mutations in the CFTR gene, leading to thickened secretions in various organs including the lungs and pancreas. Patients often experience recurrent respiratory infections due to obstructed airways and may also have CBAVD due to abnormal development of the reproductive tract. Coeliac Disease: This autoimmune disorder primarily affects the gastrointestinal system and does not typically present with absent vas deferens or recurrent chest infections as primary symptoms. Gardner’s Syndrome: This is a genetic disorder characterized by multiple polyps in the colon along with other tumors and skin lesions but does not correlate directly with respiratory issues or absent vas deferens. Conclusion Given that this patient has recurrent chest infections along with congenital bilateral absence of the vas deferens, cystic fibrosis emerges as the most likely underlying disease association due to its well-documented connection between respiratory complications and reproductive tract anomalies such as CBAVD. Therefore, based on this analysis: Cystic fibrosis Absence of the vas deferens Absence of the vas may be unilateral or bilateral Cystic fibrosis CFTR gene mutations are the cause in 40% of cases Some non CF cases are due to unilateral renal agenesis Sperm harvesting may allow for assisted conception

Answer 177

Assessment of the Clinical Scenario In this clinical scenario, we have an infant presenting with respiratory infection symptoms and posterior rib fractures identified on a chest radiograph. The infant was born prematurely at 37 weeks’ gestation and had a transient episode of tachypnoea that resolved quickly. Additionally, there is a notable increase in head circumference that has crossed three centiles since birth. Step 1: Analyzing the Symptoms Respiratory Infection: This can be common in infants, especially those born prematurely due to underdeveloped lungs. Posterior Rib Fractures: The presence of rib fractures in an infant raises concern for potential underlying issues. In infants, rib fractures can occur due to various reasons, including accidental trauma or non-accidental injury (abuse). Increased Head Circumference: A rapid increase in head circumference could indicate conditions such as hydrocephalus or other intracranial pathology. Step 2: Evaluating Possible Causes Accidental Fracture: While possible, the specific location of the fractures (posterior ribs) and the context suggest a higher likelihood of non-accidental injury. Paget’s Disease: This condition primarily affects older adults and is characterized by abnormal bone remodeling. It is not relevant in this case involving an infant. Myeloproliferative Disorder: These disorders involve excessive production of blood cells but do not typically present with rib fractures or increased head circumference as primary symptoms. Non-Accidental Injury: Given the combination of posterior rib fractures and rapid increase in head circumference, non-accidental injury (child abuse) becomes a significant consideration. Rib fractures are often associated with physical abuse in infants, particularly when they are located posteriorly. Osteomalacia: This condition involves softening of bones due to vitamin D deficiency but would not typically present with isolated rib fractures or increased head circumference without other systemic signs. Step 3: Conclusion Considering all these factors, the most likely underlying issue for this infant is non-accidental injury. The combination of posterior rib fractures and excessive increase in head circumference strongly suggests that there may be underlying trauma or abuse rather than benign causes. Final Answer: Non accidental injury Posterior rib fractures are extremely unusual in neonates. The change in head size may be accounted for by hydrocephalus which may occur as a sequelae from head injury. Paediatric fractures Paediatric fracture types Type Injury pattern Complete fracture Both sides of cortex are breached Toddlers fracture Oblique tibial fracture in infants Plastic deformity Stress on bone resulting in deformity without cortical disruption Greenstick fracture Unilateral cortical breach only Buckle fracture Incomplete cortical disruption resulting in periosteal haematoma only Growth plate fractures In paediatric practice fractures may also involve the growth plate and these injuries are classified according to the Salter- Harris system (given below): Type Injury pattern I Fracture through the physis only (x-ray often normal) II Fracture through the physis and metaphysis III Fracture through the physis and epiphyisis to include the joint IV Fracture involving the physis, metaphysis and epiphysis V Crush injury involving the physis (x-ray may resemble type I, and appear normal) As a general rule it is safer to assume that growth plate tenderness is indicative of an underlying fracture even if the x-ray appears normal. Injuries of Types III, IV and V will usually require surgery. Type V injuries are often associated with disruption to growth. Non accidental injury Delayed presentation Delay in attaining milestones Lack of concordance between proposed and actual mechanism of injury Multiple injuries Injuries at sites not commonly exposed to trauma Children on the at risk register Pathological fractures Genetic conditions, such as osteogenesis imperfecta, may cause pathological fractures. Osteogenesis imperfecta Defective osteoid formation due to congenital inability to produce adequate intercellular substances like osteoid, collagen and dentine. Failure of maturation of collagen in all the connective tissues. Radiology may show translucent bones, multiple fractures, particularly of the long bones, wormian bones (irregular patches of ossification) and a trefoil pelvis. Subtypes Type I The collagen is normal quality but insufficient quantity. Type II- Poor collagen quantity and quality. Type III- Collagen poorly formed. Normal quantity. Type IV- Sufficient collagen quantity but poor quality. Osteopetrosis Bones become harder and more dense. Autosomal recessive condition. It is commonest in young adults. Radiology reveals a lack of differentiation between the cortex and the medulla described as marble bone.

Answer 178

The rectum has the potential to generate secretions rich in potassium. This is the rationale behind administration of resins for hyperkalaemia and the development of hypokalaemia in patients with villous adenoma of the rectum. Potassium secretion -GI tract Potassium secretions Salivary glands Variable may be up to 60mmol/L Stomach 10 mmol/L Bile 5 mmol/L Pancreas 4-5 mmol/L Small bowel 10 mmol/L Rectum 30 mmol/L The above table provides average figures only and the exact composition varies depending upon the existence of disease, serum aldosterone levels and serum pH. A key point to remember for the exam is that gastric potassium secretions are low. Hypokalaemia may occur in vomiting, usually as a result of renal wasting of potassium, not because of potassium loss in vomit.

Answer 179

This patch of skin is supplied by the axillary nerve Axillary nerve Terminal branch of the posterior cord of the brachial plexus Root values C5 and C6 Descends posterior to the axillary artery at the lower border of subscapularis and then passes through quadrangular space with the posterior circumflex humeral vessels Divides into anterior and posterior branches Innervates deltoid muscle and small patch of skin over deltoid

Answer 180

The ureter is the most posterior structure at the hilum of the right kidney and would therefore be encountered first during a posterior approach. Renal arteries The right renal artery is longer than the left renal artery The renal vein/artery/pelvis enter the kidney at the hilum Relations Right Anterior- IVC, right renal vein, the head of the pancreas, and the descending part of the duodenum Left Anterior- left renal vein, the tail of the pancreas Branches The renal arteries are direct branches off the aorta (upper border of L2- right side and L1 - left side) In 30% there may be accessory arteries (mainly left side). Instead of entering the kidney at the hilum, they usually pierce the upper or lower part of the organ. Before reaching the hilum of the kidney, each artery divides into four or five segmental branches (renal vein anterior and ureter posterior); which then divide within the sinus into lobar arteries supplying each pyramid and cortex. Each vessel gives off some small inferior suprarenal branches to the suprarenal gland, the ureter, and the surrounding cellular tissue and muscles.

Answer 181

Virus Associated with Kaposi’s Sarcoma Kaposi’s sarcoma (KS) is a type of cancer that primarily affects the skin, but can also involve other organs. It is characterized by the development of tumors that appear as purple or brown lesions on the skin and can be associated with significant morbidity. Understanding the viral etiology of Kaposi’s sarcoma is crucial for both diagnosis and treatment. Human Herpes Virus 8 (HHV-8) The primary virus associated with Kaposi’s sarcoma is Human herpes virus 8 (HHV-8), also known as Kaposi’s sarcoma-associated herpesvirus (KSHV). HHV-8 was discovered in 1994 and has since been established as a necessary factor in the development of KS, particularly in immunocompromised individuals, such as those with HIV/AIDS. Mechanism of Action: HHV-8 infects endothelial cells, which line blood vessels, leading to their proliferation and the formation of vascular tumors characteristic of KS. The virus encodes several proteins that interfere with normal cellular processes, promoting cell survival and proliferation while inhibiting apoptosis (programmed cell death). Epidemiology: The prevalence of HHV-8 varies geographically and demographically. It is more common in certain populations, including men who have sex with men and individuals from regions such as sub-Saharan Africa where KS is endemic. Clinical Presentation: In patients who are immunocompromised, particularly those with HIV/AIDS, KS can present aggressively. In contrast, in immunocompetent individuals, KS may remain asymptomatic or present more indolently. Other Viruses Considered While HHV-8 is the primary virus linked to Kaposi’s sarcoma, other viruses listed in the question have different associations: Human Papillomavirus 16 & 18 (HPV): These viruses are primarily associated with cervical cancer and other anogenital cancers but are not directly linked to Kaposi’s sarcoma. Human T-Lymphotropic Virus 1 (HTLV-1): This virus is associated with adult T-cell leukemia/lymphoma but does not have a direct connection to KS. Epstein-Barr Virus (EBV): While EBV has been implicated in various lymphoproliferative disorders and some forms of lymphoma, it does not have a direct causal relationship with Kaposi’s sarcoma. In conclusion, after analyzing the associations between these viruses and Kaposi’s sarcoma: The correct answer is: Human herpes virus 8 Oncoviruses Viruses which cause cancer These may be detected on blood test and prevented by vaccine These are the main types of oncoviruses and their diseases: Oncovirus Cancer Epstein-Barr virus Burkitt's lymphoma Hodgkin's lymphoma Post transplant lymphoma Nasopharyngeal carcinoma Human papillomavirus 16/18 Cervical cancer Anal cancer Penile cancer Vulval cancer Oropharyneal cancer Human herpes virus 8 Kaposi's sarcoma Hepatitis B virus Hepatocellular carcinoma Hepatitis C virus Hepatocellular carcinoma Human T-lymphotropic virus 1 Tropical spastic paraparesis Adult T cell leukaemia

Answer 182

Surgery is indicated in less than 10% of cases. However, severe deformity is one of the indications for surgery. Lymphovenous anastomosis is indicated where the proximal lymphatics are not patent. When the overlying skin is healthy (and limb deformity a problem), a Homans procedure is a reasonable first line operative option. Lymphoedema - Due to impaired lymphatic drainage in the presence of normal capillary function. Lymphoedema causes the accumulation of protein rich fluid, subdermal fibrosis and dermal thickening. Characteristically fluid is confined to the epifascial space (skin and subcutaneous tissues); muscle compartments are free of oedema. It involves the foot, unlike other forms of oedema. There may be a 'buffalo hump' on the dorsum of the foot and the skin cannot be pinched due to subcutaneous fibrosis. Causes of lymphoedema Primary Congenital < 1 year: sporadic, Milroy's disease Onset 1-35 years: sporadic, Meige's disease > 35 years: Tarda Secondary Bacterial/fungal/parasitic infection (filariasis) Lymphatic malignancy Radiotherapy to lymph nodes Surgical resection of lymph nodes DVT Thrombophlebitis Indications for surgery Marked disability or deformity from limb swelling Lymphoedema caused by proximal lymphatic obstruction with patent distal lymphatics suitable for a lymphatic drainage procedure Lymphocutaneous fistulae and megalymphatics Procedures Homans operation Reduction procedure with preservation of overlying skin (which must be in good condition). Skin flaps are raised and the underlying tissue excised. Limb circumference typically reduced by a third. Charles operation All skin and subcutaneous tissue around the calf are excised down to the deep fascia. Split skin grafts are placed over the site. May be performed if overlying skin is not in good condition. Larger reduction in size than with Homans procedure. Lymphovenous anastamosis Identifiable lymphatics are anastomosed to sub dermal venules. Usually indicated in 2% of patients with proximal lymphatic obstruction and normal distal lymphatics.

Answer 183

Anticoagulation will worsen compartment syndrome. Compartment syndrome - This is a particular complication that may occur following fractures (or following ischaemia re-perfusion injury in vascular patients). It is characterised by raised pressure within a closed anatomical space. The raised pressure within the compartment will eventually compromise tissue perfusion resulting in necrosis. The two main fractures carrying this complication include supracondylar fractures and tibial shaft injuries. Symptoms and signs Pain, especially on movement (even passive) Parasthesiae Pallor may be present Arterial pulsation may still be felt as the necrosis occurs as a result of microvascular compromise Paralysis of the muscle group may occur Diagnosis Is made by measurement of intracompartmental pressure measurements. Pressures in excess of 20mmHg are abnormal and >40mmHg is diagnostic. Treatment This is essentially prompt and extensive fasciotomies In the lower limb the deep muscles may be inadequately decompressed by the inexperienced operator when smaller incisions are performed Myoglobinuria may occur following fasciotomy and result in renal failure and for this reason these patients require aggressive IV fluids Where muscle groups are frankly necrotic at fasciotomy they should be debrided and amputation may have to be considered Death of muscle groups may occur within 4-6 hours

Answer 184

The radial nerve passes through the triangular interval to leave the axilla. The superior border of this is bounded by the teres major muscle to which the radial nerve is closely related. Radial nerve Continuation of posterior cord of the brachial plexus (root values C5 to T1) Path In the axilla: lies posterior to the axillary artery on subscapularis, latissimus dorsi and teres major. Enters the arm between the brachial artery and the long head of triceps (medial to humerus). Spirals around the posterior surface of the humerus in the groove for the radial nerve. At the distal third of the lateral border of the humerus it then pierces the intermuscular septum and descends in front of the lateral epicondyle. At the lateral epicondyle it lies deeply between brachialis and brachioradialis where it then divides into a superficial and deep terminal branch. Deep branch crosses the supinator to become the posterior interosseous nerve. Regions innervated Motor (main nerve) Triceps Anconeus Brachioradialis Extensor carpi radialis Motor (posterior interosseous branch) Supinator Extensor carpi ulnaris Extensor digitorum Extensor indicis Extensor digiti minimi Extensor pollicis longus and brevis Abductor pollicis longus Sensory The area of skin supplying the proximal phalanges on the dorsal aspect of the hand is supplied by the radial nerve (this does not apply to the little finger and part of the ring finger) Muscular innervation and effect of denervation Anatomical location Muscle affected Effect of paralysis Shoulder Long head of triceps Minor effects on shoulder stability in abduction Arm Triceps Loss of elbow extension Forearm Supinator Brachioradialis Extensor carpi radialis longus and brevis

Answer 185

Axillary nerve passes through the quadrangular space Axillary nerve Terminal branch of the posterior cord of the brachial plexus Root values C5 and C6 Descends posterior to the axillary artery at the lower border of subscapularis and then passes through quadrangular space with the posterior circumflex humeral vessels Divides into anterior and posterior branches Innervates deltoid muscle and small patch of skin over deltoid

Answer 186

LHRH analogues may cause flare of metastatic disease and anti androgens should be administered to counter this. Surgical orchidectomy reduces testosterone levels within 8 hours (but fails to reduce adrenal androgen release). Cyproterone and flutamide are androgen blockers that may be considered as add on therapy to reduce the risk of tumour flare when commencing treatment with LH RH analogues. Prostate Cancer Prostate Cancer This is a common condition and up to 30,000 men are diagnosed with the condition each year. Up to 9,000 will die in in the UK from the condition per year. Diagnosis Early prostate cancers have few symptoms. Metastatic disease may present as bone pain. Locally advanced disease may present as pelvic pain or with urinary symptoms. Prostate specific antigen measurement Digital rectal examination Trans rectal USS (+/- biopsy) MRI/ CT and bone scan for staging. PSA Test The normal upper limit for PSA is 4ng/ml. However, in this group will lie patients with benign disease and some with localised prostate cancer. False positives may be due to prostatitis, UTI, BPH, vigorous DRE. The percentage of free: total PSA may help to distinguish benign disease from cancer. Values of <20% are suggestive of cancer and biopsy is advised. Pathology 95% adenocarcinoma In situ malignancy is sometimes found in areas adjacent to cancer. Multiple biopsies needed to call true in situ disease. Often multifocal- 70% lie in the peripheral zone. Graded using the Gleason grading system, two grades awarded 1 for most dominant grade (on scale of 1-5) and 2 for second most dominant grade (scale 1-5). The two added together give the Gleason score. Where 2 is best prognosis and 10 the worst. Lymphatic spread occurs first to the obturator nodes and local extra prostatic spread to the seminal vesicles is associated with distant disease. Treatment Watch and wait- Elderly, multiple co-morbidities, low Gleason score Radiotherapy (External)- Both potentially curative and palliative therapy possible. However, radiation proctitis and rectal malignancy are late problems. Brachytherapy is a modification allowing internal radiotherapy. Surgery- Radical prostatectomy. Surgical removal of the prostate is the standard treatment for localised disease. The robot is being used increasingly for this procedure. As well as the prostate the obturator nodes are also removed to complement the staging process. Erectile dysfunction is a common side effect. Survival may be better than with radiotherapy (see references). Functional outcomes are better when a robotic approach is used. Hormonal therapy- Testosterone stimulates prostate tissue and prostatic cancers usually show some degree of testosterone dependence. 95% of testosterone is derived from the testis and bilateral orchidectomy may be used for this reason. Pharmacological alternatives include LHRH analogues and anti androgens (which may be given in combination). In the UK the National Institute for Clinical Excellence (NICE) suggests that active surveillance is the preferred option for low risk men. It is particularly suitable for men with clinical stage T1c, Gleason score 3+3 and PSA density < 0.15 ng/ml/ml who have cancer in less than 50% of their biopsy cores, with < 10 mm of any core involved. Candidates for active surveillance should: have had at least 10 biopsy cores taken have at least one re-biopsy. If men on active surveillance show evidence of disease progression, offer radical treatment. Treatment decisions should be made with the man, taking into account co-morbidities and life expectancy.

Answer 187

A neuronal injury such as this will result in Wallerian degeneration even though the nerve remains in continuity. Neuromas may well form. Nerve injury There are 3 types of nerve injury: Neuropraxia Nerve intact but electrical conduction is affected Full recovery Autonomic function preserved Wallerian degeneration does not occur Axonotmesis Axon is damaged and the myelin sheath is preserved. The connective tissue framework is not affected. Wallerian degeneration occurs. Neurotmesis Disruption of the axon, myelin sheath and surrounding connective tissue. Wallerian degeneration occurs. Wallerian Degeneration Axonal degeneration distal to the site of injury. Typically begins 24-36 hours following injury. Axons are excitable prior to degeneration occurring. Myelin sheath degenerates and is phagocytosed by tissue macrophages. Nerve repair Neuronal repair may only occur physiologically where nerves are in direct contact. Where a large defect is present, the process of nerve regeneration is hampered. It may not occur at all or result in the formation of a neuroma. Where nerve regrowth occurs it is typically at a rate of 1mm per day.

Answer 188

The maximum voluntary ventilation is the maximal ventilation over the course of 1 minute. Definitions Tidal volume (TV) Is the volume of air inspired and expired during each ventilatory cycle at rest. It is normally 500mls in males and 340mls in females. Inspiratory reserve volume (IRV) Is the maximum volume of air that can be forcibly inhaled following a normal inspiration. 3000mls. Expiratory reserve volume (ERV) Is the maximum volume of air that can be forcibly exhaled following a normal expiration. 1000mls. Residual volume (RV) Is that volume of air remaining in the lungs after a maximal expiration. RV = FRC - ERV. 1500mls. Functional residual capacity (FRC) Is the volume of air remaining in the lungs at the end of a normal expiration. FRC = RV + ERV. 2500mls. Vital capacity (VC) Is the maximal volume of air that can be forcibly exhaled after a maximal inspiration. VC = TV + IRV + ERV. 4500mls in males, 3500mls in females. Total lung capacity (TLC) Is the volume of air in the lungs at the end of a maximal inspiration. TLC = FRC + TV + IRV = VC + RV. 5500-6000mls. Forced vital capacity (FVC) The volume of air that can be maximally forcefully exhaled.

Answer 189

A-The vocal cords have no lymphatic drainage and therefore this region serves as a lymphatic watershed. The supraglottic part drains to the upper deep cervical nodes through vessels piercing the thyrohyoid membrane. The sub glottic part drains to the pre laryngeal, pre tracheal and inferior deep cervical nodes. The aryepiglottic and vestibular folds have a rich lymphatic drainage and will metastasise early. Larynx The larynx lies in the anterior part of the neck at the levels of C3 to C6 vertebral bodies. The laryngeal skeleton consists of a number of cartilagenous segments. Three of these are paired; arytenoid, corniculate and cuneiform. Three are single; thyroid, cricoid and epiglottic. The cricoid cartilage forms a complete ring (the only one to do so). The laryngeal cavity extends from the laryngeal inlet to the level of the inferior border of the cricoid cartilage. Divisions of the laryngeal cavity Laryngeal vestibule Superior to the vestibular folds Laryngeal ventricle Lies between vestibular folds and superior to the vocal cords Infraglottic cavity Extends from vocal cords to inferior border of the cricoid cartilage The vocal folds (true vocal cords) control sound production. The apex of each fold projects medially into the laryngeal cavity. Each vocal fold includes: Vocal ligament Vocalis muscle (most medial part of thyroarytenoid muscle) The glottis is composed of the vocal folds, processes and rima glottidis. The rima glottidis is the narrowest potential site within the larynx, as the vocal cords may be completely opposed, forming a complete barrier. Muscles of the larynx Muscle Origin Insertion Innervation Action Posterior cricoarytenoid Posterior aspect of lamina of cricoid Muscular process of arytenoid Recurrent Laryngeal Abducts vocal fold Lateral cricoarytenoid Arch of cricoid Muscular process of arytenoid Recurrent laryngeal Adducts vocal fold Thyroarytenoid Posterior aspect of thyroid cartilage Muscular process of arytenoid Recurrent laryngeal Relaxes vocal fold Transverse and oblique arytenoids Arytenoid cartilage Contralateral arytenoid Recurrent laryngeal Closure of intercartilagenous part of the rima glottidis Vocalis Depression between lamina of thyroid cartilage Vocal ligament and vocal process of arytenoid cartilage Recurrent laryngeal Relaxes posterior vocal ligament, tenses anterior part Cricothyroid Anterolateral part of cricoid Inferior margin and horn of thyroid cartilage External laryngeal Tenses vocal fold Blood supply Arterial supply is via the laryngeal arteries, branches of the superior and inferior thyroid arteries. The superior laryngeal artery is closely related to the internal laryngeal nerve. The inferior laryngeal artery is related to the inferior laryngeal nerve. Venous drainage is via superior and inferior laryngeal veins, the former draining into the superior thyroid vein and the latter draining into the middle thyroid vein, or thyroid venous plexus. Lymphatic drainage The vocal cords have no lymphatic drainage and this site acts as a lymphatic watershed. Supraglottic part Upper deep cervical nodes Subglottic part Prelaryngeal and pretracheal nodes and inferior deep cervical nodes The aryepiglottic fold and vestibular folds have a dense plexus of lymphatics associated with them and malignancies at these sites have a greater propensity for nodal metastasis.

Answer 190

There are no valves which is why it is relatively easy to insert a CVP line from the internal jugular vein into the right atrium. Superior vena cava Drainage Head and neck Upper limbs Thorax Part of abdominal walls Formation Subclavian and internal jugular veins unite to form the right and left brachiocephalic veins These unite to form the SVC Azygos vein joins the SVC before it enters the right atrium Relations Anterior Anterior margins of the right lung and pleura Posteromedial Trachea and right vagus nerve Posterolateral Posterior aspects of right lung and pleura Pulmonary hilum is posterior Right lateral Right phrenic nerve and pleura Left lateral Brachiocephalic artery and ascending aorta Developmental variations Anomalies of the connection of the SVC are recognised. In some individuals a persistent left sided SVC drains into the right atrium via an enlarged orifice of the coronary sinus. More rarely the left sided vena cava may connect directly with the superior aspect of the left atrium, usually associated with an un-roofing of the coronary sinus. The commonest lesion of the IVC is for its abdominal course to be interrupted, with drainage achieved via the azygos venous system. This may occur in patients with left sided atrial isomerism.

Answer 191

Cohort studies - relative risk Study design The following table highlights the main features of the main types of study: Randomised controlled trial Participants randomly allocated to intervention or control group (e.g. standard treatment or placebo) Practical or ethical problems may limit use Cohort study Observational and prospective. Two (or more) are selected according to their exposure to a particular agent (e.g. medicine, toxin) and followed up to see how many develop a disease or other outcome. The usual outcome measure is the relative risk. Examples include Framingham Heart Study Case-control study Observational and retrospective. Patients with a particular condition (cases) are identified and matched with controls. Data is then collected on past exposure to a possible causal agent for the condition. The usual outcome measure is the odds ratio. Inexpensive, produce quick results Useful for studying rare conditions Prone to confounding Cross-sectional survey Provide a 'snapshot', sometimes called prevalence studies Provide weak evidence of cause and effect

Answer 192

This baby is a full term and has > 14 days of jaundice, therefore needs an urgent conjugated bilirubin check to rule out biliary atresia. If physiological jaundice the unconjugated bilirubin levels will be increased. Isotope scanning may be used in diagnosis, but a definitive diagnosis is normally made during a laparotomy. Biliary atresia 1 in 17000 affected Biliary tree lumen is obliterated by an inflammatory cholangiopathy causing progressive liver damage Clinical features Infant well in 1st few weeks of life No family history of liver disease Jaundice in infants > 14 days in term infants (>21 days in pre term infants) Pale stool, yellow urine (colourless in babies) Associated with cardiac malformations, polysplenia, situs inversus Investigation Conjugated bilirubin (prolonged physiological jaundice or breast milk jaundice will cause a rise in unconjugated bilirubin, whereas those with obstructive liver disease will have a rise in conjugated bilirubin) Ultrasound of the liver (excludes extrahepatic causes, in biliary atresia infant may have tiny or invisible gallbladder) Hepato-iminodiacetic acid radionuclide scan (good uptake but no excretion usually seen) Management Early recognition is important to prevent liver transplantation. Nutritional support. Roux-en-Y portojejunostomy (Kasai procedure). If Kasai procedure fails or late recognition, a liver transplant becomes the only option.

Answer 193

The ileo - colic artery supplies the caecum and would require high ligation during a right hemicolectomy. The middle colic artery should generally be preserved when resecting a caecal lesion. This question is essentially asking you to name the vessel supplying the caecum. The SMA does not directly supply the caecum, it is the ileocolic artery which does this. Caecum Location Proximal right colon below the ileocaecal valve Intraperitoneal Posterior relations Psoas Iliacus Femoral nerve Genitofemoral nerve Gonadal vessels Anterior relations Greater omentum Arterial supply Ileocolic artery Lymphatic drainage Mesenteric nodes accompany the venous drainage The caecum is the most distensible part of the colon and in complete large bowel obstruction with a competent ileocaecal valve the most likely site of eventual perforation.

Answer 194

Damage to the deep branch of the ulnar nerve may result in an inability to adduct the thumb. This is tested clinically by trying to withdraw a piece of paper from a patients hand grasped between thumb and index finger. Adductor pollicis Origin Insertion Nerve supply Actions Tendon sheath of flexor carpi radialis Bases of second, third and fourth metacarpals Anterior aspect of the trapezoid and capitate bones Transverse head comes from the longitudinal ride of the third metacarpal

Answer 195

This child is short, has hyperactivity (disruptive behaviour) and is within the age range for Perthes disease. Hyperactivity and short stature are associated with Perthes disease. Paediatric orthopaedics Diagnosis Mode of presentation Treatment Radiology Developmental dysplasia of the hip Usually diagnosed in infancy by screening tests. May be bilateral, when disease is unilateral there may be leg length inequality. As disease progresses child may limp and then early onset arthritis. More common in extended breech babies. Splints and harnesses or traction. In later years osteotomy and hip realignment procedures may be needed. In arthritis a joint replacement may be needed. However, this is best deferred if possible as it will almost certainly require revision. Initially no obvious change on plain films and USS gives best resolution until 3 months of age. On plain films Shentons line should form a smooth arc Perthes Disease Hip pain (may be referred to the knee) usually occurring between 5 and 12 years of age. Bilateral disease in 20%. Remove pressure from joint to allow normal development. Physiotherapy. Usually self-limiting if diagnosed and treated promptly. X-rays will show flattened femoral head. Eventually in untreated cases the femoral head will fragment. Slipped upper femoral epiphysis Typically seen in obese male adolescents. Pain is often referred to the knee. Limitation to internal rotation is usually seen. Knee pain is usually present 2 months prior to hip slipping. Bilateral in 20%. Bed rest and non-weight bearing. Aim to avoid avascular necrosis. If severe slippage or risk of it occurring then percutaneous pinning of the hip may be required. X-rays will show the femoral head displaced and falling inferolaterally (like a melting ice cream cone) The Southwick angle gives indication of disease severity

Answer 196

The conus arteriosus (infundibulum) is the smooth walled outflow tract of the right ventricle leading to the pulmonary trunk.

Answer 197

The sympathetic chain lies posterior to the parietal pleura. During a thorascopic sympathetomy this structure will need to be divided. The intercostal vessels lie posteriorly. They may be damaged with troublesome bleeding but otherwise are best left alone as deliberate division will not improve surgical access

Answer 198

The transfusion of packed red cells has been shown to increase serum potassium levels. The risk is higher with large volume transfusions and with old blood.

Answer 199

Samples of CSF are normally obtained by inserting a needle between the third and fourth lumbar vertebrae. The tip of the needle lies in the sub arachnoid space, the spinal cord terminates at L1 and is not at risk of injury. Clinical evidence of raised intracranial pressure is a contraindication to lumbar puncture.

Answer 200

ITP causes splenic sequestration of platelets. Therefore a platelet transfusion should be carefully timed. Too soon and it will be ineffective. Too late and unnecessary bleeding will occur. The optimal time is after the splenic artery has been ligated.

Answer 201

All of the above

Answer 202

Median Median nerve The median nerve is formed by the union of a lateral and medial root respectively from the lateral (C5,6,7) and medial (C8 and T1) cords of the brachial plexus; the medial root passes anterior to the third part of the axillary artery. The nerve descends lateral to the brachial artery, crosses to its medial side (usually passing anterior to the artery). It passes deep to the bicipital aponeurosis and the median cubital vein at the elbow. It passes between the two heads of the pronator teres muscle, and runs on the deep surface of flexor digitorum superficialis (within its fascial sheath). Near the wrist it becomes superficial between the tendons of flexor digitorum superficialis and flexor carpi radialis, deep to palmaris longus tendon. It passes deep to the flexor retinaculum to enter the palm, but lies anterior to the long flexor tendons within the carpal tunnel. Branches Region Branch Upper arm No branches, although the nerve commonly communicates with the musculocutaneous nerve Forearm Pronator teres Pronator quadratus Flexor carpi radialis Palmaris longus Flexor digitorum superficialis Flexor pollicis longus Flexor digitorum profundus (only the radial half) Distal forearm Palmar cutaneous branch Hand (Motor) Motor supply (LOAF) Lateral 2 lumbricals Opponens pollicis Abductor pollicis brevis Flexor pollicis brevis Hand (Sensory) Over thumb and lateral 2 Â½ fingers On the palmar aspect this projects proximally, on the dorsal aspect only the distal regions are innervated with the radial nerve providing the more proximal cutaneous innervation. Patterns of damage Damage at wrist e.g. carpal tunnel syndrome paralysis and wasting of thenar eminence muscles and opponens pollicis (ape hand deformity) sensory loss to palmar aspect of lateral (radial) 2 Â½ fingers Damage at elbow, as above plus: unable to pronate forearm weak wrist flexion ulnar deviation of wrist Anterior interosseous nerve (branch of median nerve) leaves just below the elbow results in loss of pronation of forearm and weakness of long flexors of thumb and index finger

Answer 203

% 15 at 5 years

Answer 204

All of the above

Answer 205

% 5-10 at 5 years

Answer 206

Pancreatic lipase is required for digestion of fat, Proteases facilitate protein and B12 absorption. Folate digestion is independent of the pancreas. Pancreas exocrine physiology Composition of pancreatic secretions Pancreatic secretions are usually 1000-1500ml per 24 hours and have a pH of 8. Secretion Source Substances secreted Enzymic Acinar cells Trypsinogen Procarboxylase Amylase Elastase Aqueous Ductal and Centroacinar cells Sodium Bicarbonate Water Potassium Chloride NB: Sodium and potassium reflect their plasma levels; chloride and bicarbonate vary with flow rate Regulation The cephalic and gastric phases (neuronal and physical) are less important in regulating the pancreatic secretions. The effect of digested material in the small bowel stimulates CCK release and ACh which stimulate acinar and ductal cells. Of these CCK is the most potent stimulus. In the case of the ductal cells these are potently stimulated by secretin which is released by the S cells of the duodenum. This results in an increase in bicarbonate. Enzyme activation Trypsinogen is converted via enterokinase to active trypsin in the duodenum. Trypsin then activates the other inactive enzymes

Answer 207

The tibial nerve lies superior to the vessels in the inferior aspect of the popliteal fossa. In the upper part of the fossa the tibial nerve lies lateral to the vessels, it then passes superficial to them to lie medially. The popliteal artery is the deepest structure in the popliteal fossa.

Answer 208

The correct answer is Angiodysplasia Angiodysplasia can be difficult to identify and treat. The colonoscopic stigmata are easily missed by poor bowel preparation. Lower Gastrointestinal bleeding Colonic bleeding This typically presents as bright red or dark red blood per rectum. Colonic bleeding rarely presents as malaena type stool, this is because blood in the colon has a powerful laxative effect and is rarely retained long enough for transformation to occur and because the digestive enzymes present in the small bowel are not present in the colon. Up to 15% of patients presenting with haemochezia will have an upper gastrointestinal source of haemorrhage. As a general rule right sided bleeds tend to present with darker coloured blood than left sided bleeds. Haemorrhoidal bleeding typically presents as bright red rectal bleeding that occurs post defecation either onto toilet paper or into the toilet pan. It is very unusual for haemorrhoids alone to cause any degree of haemodynamic compromise. Causes Cause Presenting features Colitis Bleeding may be brisk in advanced cases, diarrhoea is commonly present. Abdominal x-ray may show featureless colon. Diverticular disease Acute diverticulitis often is not complicated by major bleeding and diverticular bleeds often occur sporadically. 75% all will cease spontaneously within 24-48 hours. Bleeding is often dark and of large volume. Cancer Colonic cancers often bleed and for many patients this may be the first sign of the disease. Major bleeding from early lesions is uncommon Haemorrhoidal bleeding Typically bright red bleeding occurring post defecation. Although patients may give graphic descriptions bleeding of sufficient volume to cause haemodynamic compromise is rare. Angiodysplasia Apart from bleeding, which may be massive, these arteriovenous lesions cause little in the way of symptoms. The right side of the colon is more commonly affected. Management Prompt correction of any haemodynamic compromise is required. Unlike upper gastrointestinal bleeding the first line management is usually supportive. This is because in the acute setting endoscopy is rarely helpful. When haemorrhoidal bleeding is suspected a proctosigmoidoscopy is reasonable as attempts at full colonoscopy are usually time consuming and often futile. In the unstable patient the usual procedure would be an angiogram (either CT or percutaneous), when these are performed during a period of haemodynamic instability they may show a bleeding point and may be the only way of identifying a patch of angiodysplasia. In others who are more stable the standard procedure would be a colonoscopy in the elective setting. In patients undergoing angiography attempts can be made to address the lesion in question such as coiling. Otherwise surgery will be necessary. In patients with ulcerative colitis who have significant haemorrhage the standard approach would be a sub total colectomy, particularly if medical management has already been tried and is not effective. Indications for surgery Patients > 60 years Continued bleeding despite endoscopic intervention Recurrent bleeding Known cardiovascular disease with poor response to hypotension Surgery Selective mesenteric embolisation if life threatening bleeding. This is most helpful if conducted during a period of relative haemodynamic instability. If all haemodynamic parameters are normal then the bleeding is most likely to have stopped and any angiography normal in appearance. In many units a CT angiogram will replace selective angiography but the same caveats will apply. If the source of colonic bleeding is unclear; perform a laparotomy, on table colonic lavage and following this attempt a resection. A blind sub total colectomy is most unwise, for example bleeding from an small bowel arterio-venous malformation will not be treated by this manoeuvre. Summary of Acute Lower GI bleeding recommendations Consider admission if: * Over 60 years * Haemodynamically unstable/profuse PR bleeding * On aspirin or NSAID * Significant co morbidity Management All patients should have a history and examination, PR and proctoscopy Colonoscopic haemostasis aimed for in post polypectomy or diverticular bleeding References http://www.sign.ac.uk/guidelines/fulltext/105/index.html

Answer 209

Step 1: Understanding Crohn’s Disease and Its Complications Crohn’s disease is a type of inflammatory bowel disease (IBD) that can affect any part of the gastrointestinal tract but most commonly affects the terminal ileum. It is characterized by chronic inflammation, which can lead to various complications over time. Patients with Crohn’s disease are at risk for several conditions due to the nature of their illness. Step 2: Evaluating Each Condition Gallstones: Patients with Crohn’s disease, particularly those with ileal involvement, are at an increased risk for gallstones. This is primarily due to malabsorption of bile salts, which can lead to changes in bile composition and promote gallstone formation. Malabsorption: Malabsorption is a common complication in patients with Crohn’s disease, especially when the terminal ileum is affected. The terminal ileum is responsible for absorbing vitamin B12 and bile acids; thus, its dysfunction can lead to significant nutritional deficiencies. Pyoderma Gangrenosum: This is a rare skin condition associated with IBD, including Crohn’s disease. While it can occur in patients with Crohn’s, it is not as common as other complications. Amyloidosis: This condition involves the deposition of amyloid proteins in various tissues and organs and can occur in patients with chronic inflammatory diseases like Crohn’s disease. However, it is relatively rare compared to other complications. Felty’s Syndrome: This syndrome consists of rheumatoid arthritis, splenomegaly, and neutropenia (low white blood cell count). It is primarily associated with rheumatoid arthritis rather than Crohn’s disease or other forms of IBD. Step 3: Determining the Least Likely Condition Given the above evaluations: Gallstones are likely due to malabsorption. Malabsorption itself is very likely. Pyoderma gangrenosum may occur but isn’t as prevalent. Amyloidosis could develop but is less common. Felty’s syndrome has no direct association with Crohn’s disease and occurs primarily in rheumatoid arthritis patients. Thus, among these options, Felty’s syndrome stands out as the least likely condition for a patient suffering from terminal ileal Crohn’s disease. Answer: Felty’s syndrome

Answer 210

IV Pamidronate is the drug of choice as it most effective and has long lasting effects. Calcitonin would need to be given with another agent, to ensure that the hypercalcaemia is treated once its short term effects wear off. IV zoledronate is preferred in scenarios associated with malignancy.

Answer 211

Pancreatic head is supplied by the pancreaticoduodenal artery Pancreatic tail is supplied by branches of the splenic artery There is an arterial watershed in the supply between the head and tail of the pancreas. The head is supplied by the pancreaticoduodenal artery and the tail is supplied by branches of the splenic artery.

Answer 212

The most likely cause for the postoperative numbness superior to the ankle in this case is a Saphenous nerve injury. The Saphenous nerve runs alongside the long saphenous vein, which is typically addressed during procedures like saphenofemoral disconnection and vein stripping. Nerve injuries during these surgeries can lead to sensory disturbances such as numbness. It’s advisable for the patient to discuss this with their healthcare provider for a more accurate assessment. The sural nerve is related to the short saphenous vein. The saphenous nerve is related to the long saphenous vein below the knee and for this reason full length stripping of the vein is no longer advocated.

Answer 213

Tributaries of the Saphenous Vein The saphenous vein is a major superficial vein in the leg, primarily responsible for draining blood from the lower extremities. It has several tributaries that contribute to its function. To determine which of the listed veins are true tributaries of the saphenous vein, we will analyze each option step by step. Medial Marginal Vein: The medial marginal vein runs along the medial side of the foot and is known to drain into the great saphenous vein. Therefore, this option is indeed a true tributary. Superficial Epigastric Vein: This vein arises from the femoral vein and travels upward towards the abdomen, draining into the external iliac vein rather than directly into the saphenous system. Thus, it is not a tributary of the saphenous vein. Superficial Iliac Circumflex Vein: Similar to the superficial epigastric vein, this vessel also drains into the external iliac vein and does not connect with or drain into the saphenous system. Therefore, it is not a tributary of the saphenous vein. Superficial External Pudendal Veins: These veins also originate from areas around the groin and drain into either the femoral or external iliac veins rather than directly contributing to the saphenous system. Hence, they are not considered tributaries of the saphenous vein. After analyzing all four options: The only true tributary of the saphenous vein among those listed is Medial Marginal Vein. Thus, based on this detailed examination: Answer: Medial marginal

Answer 214

Cryptosporidium infection Cryptosporidium is associated with infection, particularly in those who are immunocompromised. Diarrhoea is the main disease. The cysts are typically identified on stool microscopy.

Answer 215

Duodenal polyps occur in up to 100% of patients with FAP if follow up is continued for long enough. Duodenal cancer has an incidence of 4-10%. Duodenal polyps are the commonest extra colonic lesion in FAP. Gastric fundal polyps are seen in 50% of patients. Skull osteomas are seen in Gardeners syndrome which is a variant of FAP.

Answer 216

Hypothermia: Hypothermia typically causes a leftward shift in the oxygen-haemoglobin dissociation curve. This is because lower temperatures increase hemoglobin’s affinity for oxygen, making it hold onto oxygen more tightly rather than releasing it. Respiratory Alkalosis: Respiratory alkalosis occurs when there is a decrease in carbon dioxide (CO2) levels due to hyperventilation, leading to an increase in blood pH. This condition also results in a leftward shift of the curve, as higher pH increases hemoglobin’s affinity for oxygen. Low Altitude: At low altitudes, the partial pressure of oxygen is higher compared to high altitudes; however, this does not directly cause a rightward shift in the dissociation curve. The body generally maintains normal hemoglobin-oxygen affinity at low altitudes. Decreased 2,3-DPG in Transfused Red Cells: 2,3-Diphosphoglycerate (2,3-DPG) is a metabolite produced by red blood cells that decreases hemoglobin’s affinity for oxygen when present in higher concentrations. In transfused red cells where 2,3-DPG levels are decreased (as stored blood has lower levels), there would be a leftward shift rather than a rightward one. Chronic Iron Deficiency Anaemia: Chronic iron deficiency anemia can lead to changes in hemoglobin structure and function that may result in a rightward shift of the curve due to increased production of 2,3-DPG as the body attempts to enhance tissue oxygen delivery despite reduced overall hemoglobin levels. Conclusion Based on the analysis above: The only scenario among those listed that leads to a rightward shift of the oxygen-haemoglobin dissociation curve is Chronic Iron Deficiency Anaemia. Thus, the answer is: Chronic iron deficiency anaemia Mnemonic to remember causes of right shift of the oxygen dissociation curve: CADET face RIGHT C O2 A cidosis 2,3-DPG E xercise T emperature The curve is shifted to the right when there is an increased oxygen requirement by the tissue. This includes: Increased temperature Acidosis Increased DPG: DPG is found in erythrocytes and is increased during glycolysis. It binds to the Hb molecule, thereby releasing oxygen to tissues. DPG is increased in conditions associated with poor oxygen delivery to tissues, such as anaemia and high altitude.

Answer 217

Hassall’s corpuscles are the concentric ring of epithelial cells seen in the medulla of the thymus.

Answer 218

The brachial artery begins at the lower border of teres major and terminates in the cubital fossa by branching into the radial and ulnar arteries. In the upper arm the median nerve lies closest to it in the lateral position. In the cubital fossa it lies medial to it.

Answer 219

The decision as to how best to manage patients with re-bleeding is difficult. Whilst it is tempting to offer repeat endoscopy, this intervention is best used on those with small ulcers. Large posteriorly sited duodenal ulcers are at high risk for re-bleeding and the timeframe of this event suggests that primary endoscopic haemostasis was inadequate. Surgery thus represents the safest way forward.

Answer 220

Angiosarcoma of the liver is a rare tumour. However, it is linked to working with vinyl chloride, as in this case. Although modern factories minimise the exposure to this agent, this has not always been the case.

Answer 221

Investigators in the 1960’s dehydrated and measured the sodium content of ileostomy effluent and determined this concentration. Not an experiment many would care to repeat! (120)

Answer 222

Suxamethonium may induce generalised muscular contractions following administration. This may raise serum potassium levels.

Answer 223

In the UK, platelets either come from pooling of the platelet component from four units of whole donated blood, called random donor platelets, or by plasmapharesis from a single donor. The platelets are suspended in 200-300 ml of plasma and may be stored for up to 4 days in the transfusion laboratory where they are continually agitated at 22oC to preserve function. One adult platelet pool raises the normal platelet count by 30,000 to 60,000 platelets litre. ABO identical or compatible platelets are preferred but not necessary in adults; but rhesus compatibility is required in recipients who are children and women of childbearing age to prevent haemolytic disease of the newborn.

Answer 224

Up to 4 units of SAG M Blood may be administered. Thereafter whole blood is preferred. After 8 units, clotting factors and platelets should be considered.

Answer 225

Mnemonic for contents of cavernous sinus: O TOM CAT Occulomotor nerve (III) Trochlear nerve (IV) Ophthalmic nerve (V1) Maxillary nerve (V2) Carotid artery Abducent nerve (VI) T OTOM=lateral wall components CA= components within sinus The optic nerve lies above and outside the cavernous sinus.

Answer 226

Bladder occlusion The most likely explanation for this event is a blocked catheter. This may be the result of blood clot from the ureteric anastomosis. Bladder irrigation will usually resolve the problem.

Answer 227

The correct answer is Renal artery thrombosis Right sided live donor transplants are extremely rare. This is because the vena cava precludes mobilisation of the right renal artery. The short right renal artery that is produced therefore presents a major challenge. The sudden cessation of urine output in this context is highly suggestive of an acute thrombosis. Delay in thrombectomy beyond 1 hour almost inevitably results in graft loss.

Answer 228

Action of furosemide = ascending limb of the loop of Henle Furosemide and bumetanide are loop diuretics that act by inhibiting the Na-K-Cl cotransporter in the thick ascending limb of the loop of Henle, reducing the absorption of NaCl. Diuretic agents The diuretic drugs are divided into three major classes, which are distinguished according to the site at which they impair sodium reabsorption: loop diuretics in the thick ascending loop of Henle, thiazide type diuretics in the distal tubule and connecting segment; and potassium sparing diuretics in the aldosterone - sensitive principal cells in the cortical collecting tubule. In the kidney, sodium is reabsorbed through Na+/ K+ ATPase pumps located on the basolateral membrane. These pumps return reabsorbed sodium to the circulation and maintain low intracellular sodium levels. This latter effect ensures a constant concentration gradient. Physiological effects of commonly used diuretics Site of action Diuretic Carrier or channel inhibited Percentage of filtered sodium excreted Ascending limb of loop of Henle Frusemide Na+/K+ 2Cl - carrier Up to 25% Distal tubule and connecting segment Thiazides Na+Cl- carrier Between 3 and 5% Cortical collecting tubule Spironolactone Na+/K+ ATP ase pump Between 1 and 2%

Answer 229

Oesophageal rupture Spontaneous rupture of the oesophagus may occur following an episode of vomiting. The subsequent mediastinitis can produce severe sepsis and death if not treated promptly. Adequate drainage of sepsis and early surgery are the cornerstones of management.

Answer 230

Squamous cell carcinoma The risk of squamous cell carcinoma of the oesophagus is increased in people with achalasia. The condition often presents late and has a poor prognosis.

Answer 231

Pharyngeal pouches occur when a defect occurs in killians dehiscence. Difficulty in intubation is a well recognised consequence and care must be taken to take the correct track during OGD to avoid perforation. Most cases are now treated with endoscopic stapling.

Answer 232

The portal vein transports 70% of the blood supply to the liver, while the hepatic artery provides 30%. The portal vein contains the products of digestion. The arterial and venous blood is dispersed by sinusoids to the central veins of the liver lobules; these drain into the hepatic veins and then into the IVC. The caudate lobe drains directly into the IVC rather than into other hepatic veins.

Answer 233

In Barrett’s surveillance the safest option is quadrantic (i.e. 4 biopsies, one from each quarter of the oesophagus at 2cm intervals) Low grade dysplasia in conjunction with Barretts oesphagus should be monitored with regular (6 monthly) upper GI endoscopy and quadrantic biopsies. If the disease remains static at 2 years then the screening frequency may be decreased.

Answer 234

Administer a carbohydrate based loading drink 3 hours pre operatively, and avoid intravenous fluids Patients for elective surgery should not have solids for 6 hours pre-operatively. However, clear fluids may be given up to 2 hours pre-operatively. Enhanced recovery programmes are now the standard of care in many countries around the world and involve administration of carbohydrate loading drinks. The routine administration of 5% dextrose in the scenarios given above would convey little in the way of benefit and increase the risks of electrolyte derangement post operatively

Answer 235

The ilioinguinal nerve passes through the inguinal canal and is the nerve most commonly identified during hernia surgery. The genitofemoral nerve splits into two branches, the genital branch passes through the inguinal canal within the cord structures. The femoral branch of the genitofemoral nerve enters the thigh posterior to the inguinal ligament, lateral to the femoral artery. The iliohypogastric nerve pierces the external oblique aponeurosis above the superficial inguinal ring.

Answer 236

Work of breathing is decreased which is one reasons it is popular option for weaning ventilated patients. Humidified air in this setting helps to reduce the viscosity of mucous that forms.

Answer 237

At the 3rd month the foetus’s spinal cord occupies the entire length of the vertebral canal. The vertebral column then grows longer exceeding the growth rate of the spinal cord. This results with the cord being at L3 at birth and L1-2 by adulthood.

Answer 238

Fascial layers surrounding the rectum: Anteriorly lies the fascia of Denonvilliers Posteriorly lies Waldeyers fascia Waldeyers fascia separates the mesorectum from the sacrum and will need to be divided.

Answer 239

Acalculous cholecystitis Acalculous cholecystitis is more common in patients with an underlying co-morbidity. The morbidity and mortality following intervention are higher than in conventional gallstone disease.

Answer 240

Cholangitis Features of jaundice, fever and systemic sepsis are typical of cholangitis.

Answer 241

Acute cholecystitis The features of pain and fever with right upper quadrant pain are suggestive of acute cholecystitis. The short nature of the history makes an abscess less likely.

Answer 242

The external aspect of the tympanic membrane is lined by stratified squamous epithelium. This is significant clinically in the development of middle ear infections when this type of epithelium may migrate inside the middle ear.

Answer 243

The SMA leaves the aorta at L1. It passes under the neck of the pancreas prior to giving its first branch the inferior pancreatico-duodenal artery.

Answer 244

W. Bancrofti is the commonest cause of filariasis leading to lymphatic obstruction. Infection with Loa loa typically occurs in the African sub continent and usually results in generalised sub cutaneous infections without lymphatic obstruction. Trypanosomal infections would not produce this clinical picture.

Answer 245

It supplies biceps, brachialis and coracobrachialis. If damaged then elbow flexion rather than extension will be impaired.

Answer 246

Mnemonic: OVALE O tic ganglion V3 (Mandibular nerve:3rd branch of trigeminal) A ccessory meningeal artery L esser petrosal nerve E missary veins

Answer 247

The z score is determined using the normal distribution and is not a descriptive statistic

Answer 248

Cranial nerves carrying parasympathetic fibres X IX VII III (1973) The parasympathetic functions served by the cranial nerves include: III (oculomotor)Pupillary constriction and accommodation VII (facial)Lacrimal gland, submandibular and sublingual glands IX (glossopharyngeal)Parotid X (vagus)Heart and abdominal viscera The optic nerve carries no parasympathetic fibres. The cranial preganglionic parasympathetic nerves arise from specific nuclei in the CNS. These synapse at one of four parasympathetic ganglia; otic, pterygopalatine, ciliary and submandibular. From these ganglia the parasympathetic nerves complete their journey to their target tissues via CN V (trigeminal) branches (ophthalmic nerve CNV branch 1, Maxillary nerve CN V branch2, mandibular nerve CN V branch 3)

Answer 249

The left renal vein will be stretched over the neck of the anuerysm in this location and is not infrequently divided. This adds to the nephrotoxic insult of juxtarenal aortic surgery as a supra renal clamp is also often applied. Deliberate division of the Cisterna Chyli will not improve access and will result in a chyle leak. Division of the transverse colon will not help at all and would result in a high risk of graft infection. Division of the SMA is pointless for a juxtarenal procedure.

Answer 250

Application of ankle boot This is a Weber A fracture. It is a stable ankle injury and can therefore be managed conservatively. Whilst this patient could also be treated in a below knee plaster, most clinicians would nowadays treat this injury in an ankle boot. Patients should be advised to mobilise in the ankle boot, as pain allows, and can wean themselves out of the boot as the symptoms improve.

Answer 251

The correct answer is Surgical fixation This is an unstable fracture pattern with a Weber B fracture of the distal fibula and a fracture of the medial malleolus. Talar shift indicates loss of ankle mortice congruity. This injury should therefore be treated with surgical fixation.

Answer 252

Application of below knee plaster This is a Weber B fracture and therefore potentially unstable. Medial malleolar tenderness indicates deltoid ligament injury. As the fracture is currently undisplaced and the ankle mortice is congruent, the injury can be initially managed conservatively in a below knee plaster but the patient should be monitored in the outpatient clinic for fracture displacement in the first few weeks.

Answer 253

Brocas area is usually supplied by branches from the middle cerebral artery.

Answer 254

Inflammatory carcinoma Inflammatory breast cancers have an aggressive nature. Dissemination occurs early and is more resistant to adjuvent treatments than other types of breast cancer. Often occurs in pregnancy or lactation.

Answer 255

The correct answer is Invasive ductal carcinoma A post menopausal woman is more likely to have a ductal carcinoma and they tend to occur at a single focus within the breast.

Answer 256

The correct answer is Invasive lobular carcinoma This is likely to be an invasive lobular carcinoma, mainly due to the multifocal lesions and the history of previous breast cancer in the opposite breast.

Answer 257

Secretion of saliva by the parotid gland is controlled by nerve fibres originating in the inferior salivatory nucleus; these leave the brain via the tympanic nerve (branch of glossopharyngeal nerve (CN IX), travel through the tympanic plexus (located in the middle ear), and then form the lesser petrosal nerve until reaching the otic ganglion. After synapsing in the Otic ganglion, the postganglionic (postsynaptic) fibres travel as part of the auriculotemporal nerve (a branch of the mandibular nerve (V3) to reach the parotid gland.

Answer 258

The spinal cord is approximately 45cm in men and 43cm in women. The denticulate ligament is a continuation of the pia mater (innermost covering of the spinal cord) which has intermittent lateral projections attaching the spinal cord to the dura mater.

Answer 259

‘Safe Triangle’ for chest drain insertion: 5th intercostal space, mid axillary line

Answer 260

Dupuytren’s contracture Discomfort of the hand is not uncommon in Dupuytrens contracture, true pain is unusual. The disease most commonly affects the ring and little fingers.

Answer 261

Heberden’s nodes These are bony outgrowths that occur in the distal interphalangeal joint in association with osteoarthritis. They may skew the finger tip sideways. Bouchards nodes are similar, but affect the proximal interphalangeal joint.

Answer 262

Carpal tunnel syndrome Carpal tunnel syndrome commonly produces pain at night as the wrists are flexed during sleep. Compromise of the median nerve may produce wasting of the thenar eminence muscles.

Answer 263

Bouchards nodes

Answer 264

Based on the description provided, the condition being described is: H. Heberden's nodes Let's break down the key features that point to this diagnosis: 1. Age of onset: The description mentions "typically develop in middle age," which is consistent with Heberden's nodes. 2. Joint affected: The condition "typically affects the DIP joint" (Distal Interphalangeal joint). This is the defining characteristic of Heberden's nodes. 3. Presentation: - Can begin with "chronic swelling of the affected joints" or "sudden painful onset of redness, numbness, and loss of manual dexterity." - The initial inflammation and pain eventually subsides. - Results in "permanent bony outgrowth that often skews the fingertip sideways." 4. Nature of the condition: Heberden's nodes are bony enlargements of the DIP joints, which matches the description of "permanent bony outgrowth." Heberden's nodes are a sign of osteoarthritis in the hands. They are named after William Heberden, an English physician who first described them in 1802. These nodes represent osteophytes (bone spurs) that form as a result of the degenerative process in osteoarthritis. It's worth noting that while similar, this condition is different from: - Bouchard's nodes (option C), which affect the proximal interphalangeal (PIP) joints rather than the DIP joints. - The other options listed do not match the specific description provided, particularly the involvement of the DIP joint and the characteristic bony outgrowth.

Answer 265

Polymorphnuclear leucocytes, cellular debris and fibrin These are typical components of an abscess cavity. Polymorphonuclear leucocytes may be found in a granuloma if there is a focus of suppuration.

Answer 266

Seminomas typically have normal AFP and HCG. These are usually raised in teratomas and yolk sac tumours This man’s age, presenting symptoms and normal tumour markers make a seminoma the most likely diagnosis. Epididymo-orchitis does not produce irregular mass lesions which are painless. Testicular disorders Testicular cancer Testicular cancer is the most common malignancy in men aged 20-30 years. Around 95% of cases of testicular cancer are germ-cell tumours. Germ cell tumours may essentially be divided into: Tumour type Key features Tumour markers Pathology Seminoma Commonest subtype (50%) Average age at diagnosis = 40 Even advanced disease associated with 5 year survival of 73% AFP usually normal HCG elevated in 10% seminomas Lactate dehydrogenase; elevated in 10-20% seminomas (but also in many other conditions) Sheet like lobular patterns of cells with substantial fibrous component. Fibrous septa contain lymphocytic inclusions and granulomas may be seen. Non seminomatous germ cell tumours (42%) Teratoma Yolk sac tumour Choriocarcinoma Mixed germ cell tumours (10%) Younger age at presentation =20-30 years Advanced disease carries worse prognosis (48% at 5 years) Retroperitoneal lymph node dissection may be needed for residual disease after chemotherapy AFP elevated in up to 70% of cases HCG elevated in up to 40% of cases Other markers rarely helpful Risk factors for testicular cancer Cryptorchidism Infertility Family history Klinefelter's syndrome Mumps orchitis Features A painless lump is the most common presenting symptom Pain may also be present in a minority of men Other possible features include hydrocele, gynaecomastia Diagnosis Ultrasound is first-line CT scanning of the chest/ abdomen and pelvis is used for staging Tumour markers (see above) should be measured Management Orchidectomy (Inguinal approach) Chemotherapy and radiotherapy may be given depending on staging Abdominal lesions >1cm following chemotherapy may require retroperitoneal lymph node dissection. Prognosis is generally excellent 5 year survival for seminomas is around 95% if Stage I 5 year survival for teratomas is around 85% if Stage I Benign disease Epididymo-orchitis Acute epididymitis is an acute inflammation of the epididymis, often involving the testis and usually caused by bacterial infection. Infection spreads from the urethra or bladder. In men <35 years, gonorrhoea or chlamydia are the usual infections. Amiodarone is a recognised non infective cause of epididymitis, which resolves on stopping the drug. Tenderness is usually confined to the epididymis, which may facilitate differentiating it from torsion where pain usually affects the entire testis. Testicular torsion Twist of the spermatic cord resulting in testicular ischaemia and necrosis. Most common in males aged between 10 and 30 (peak incidence 13-15 years) Pain is usually severe and of sudden onset. Cremasteric reflex is lost and elevation of the testis does not ease the pain. Treatment is with surgical exploration. If a torted testis is identified then both testis should be fixed as the condition of bell clapper testis is often bilateral. Hydrocele Presents as a mass that transilluminates, usually possible to 'get above' it on examination. In younger men it should be investigated with USS to exclude tumour. In children it may occur as a result of a patent processus vaginalis. Treatment in adults is with a Lords or Jabouley procedure. Treatment in children is with trans inguinal ligation of PPV.

Answer 267

The correct answer is Insertion of self expanding metallic stent Ideally, the distant disease should be managed first and then the primary lesion addressed. A self expanding stent is likely to achieve this and avoids a stoma.

Answer 268

The correct answer is Loop colostomy of the sigmoid colon Rectal cancers should not be primarily resected prior to definitive staging and a tumour of this nature is likely to have circumferential margin involvement. Whilst a sigmoid and transverse loop colostomy would both provide an equal relief of obstruction the former procedure has the added benefit of making a subsequent resection safer, since a transverse colostomy would have to be taken down and closed during the course of subsequent surgery.

Answer 269

The correct answer is Right hemicolectomy This lesion should be amenable to standard right hemicolectomy. Extending the resection to take the middle colic vessels and distal transverse colon is unlikely to provide additional oncological benefit.

Answer 270

The most likely underlying diagnosis in this case is Choanal atresia. Choanal atresia is a congenital condition where there is a blockage or narrowing of one or both of the nasal passages, which can cause difficulty breathing. Newborns are obligate nasal breathers, so a blockage of the nasal airway can lead to episodes of cyanosis, especially during feeding (when the baby is not able to breathe through the nose) and improve when the baby cries (which opens the airway and allows the baby to breathe through the mouth). This condition can be diagnosed with nasal endoscopy or imaging and typically requires surgical correction. It’s often associated with other anomalies, so a thorough evaluation for other defects may be necessary. The other conditions listed typically have different clinical presentations: • Oesophageal reflux: Can cause vomiting or irritability, but not cyanosis that improves with crying. • Tetralogy of Fallot: Involves cyanosis, but it typically presents earlier and with more persistent symptoms rather than improving with crying. • Oesophageal atresia: Usually presents with feeding difficulties and choking, but doesn’t typically cause cyanosis that improves with crying. • Congenital diaphragmatic hernia: Causes respiratory distress, but this is usually more severe and presents earlier after birth, not specifically associated with feeding.

Answer 271

Acute pancreatitis is known to precipitate ARDS. ARDS is characterised by bilateral pulmonary infiltrates and hypoxaemia. Note that pulmonary oedema is excluded by the CVP reading < 18mmHg.

Answer 272

Let me help you determine the appropriate surgical resection margin for this melanoma case by analyzing the key characteristics: Key facts: - Melanoma confirmed by biopsy - Diameter: 1 cm - Breslow thickness: 0.1 mm (very thin) - Current margins: < 1 mm (from excisional biopsy) For melanoma, surgical margins are primarily determined by Breslow thickness. In this case: - 0.1 mm is considered a very thin melanoma (< 1 mm) - For melanomas with Breslow thickness < 1 mm, guidelines recommend a 1 cm margin - Larger margins (2-3 cm) are reserved for thicker melanomas - 5 cm margins are excessive for any melanoma - 0.5 cm would be inadequate even for thin melanomas Therefore, the correct surgical resection margin for this lesion is 1 cm. This follows current guidelines which recommend: - Melanoma in situ: 0.5-1 cm margin - Melanoma < 1 mm: 1 cm margin - Melanoma 1-2 mm: 1-2 cm margin - Melanoma > 2 mm: 2 cm margin The correct answer is 1 cm.

Answer 273

Breast implants often become surrounded by a pseudocapsule and this may secondarily then be subjected to a process of dystrophic calcification.

Answer 274

Lymphangiosarcoma is a rare condition arising as a result of chronic oedema. It is an aggressive malignancy.

Answer 275

Renal artery stenosis Renal artery stenosis typically occurs over several months and will usually result in the development of hypertension. Most cases can be assessed using duplex scanning and managed with angioplasty. Complications of renal transplantation A number of complications may occur following renal transplantation. A critical aspect of post operative care is evaluation of graft function. Post operatively, urine output is the most readily available, and easily measured, indicator of graft function. If an individual was relatively anuric pre-transplant and has a good urine output following surgery then this is more useful than it would be in someone who had a higher volume diuresis prior to transplantation. Recipients can be divided into three main groups following renal transplantation, with regard to their graft function: Immediate graft function; brisk diuresis and falling serum creatinine Slow graft function; modest urine output and slowly falling creatinine levels Delayed graft function; defined as need for dialysis post transplant Decreased urine output following surgery can be the result of hypovolvaemia or a blocked catheter (commonest causes). Other important causes include rejection, or a vascular complication. Vascular complications These may involve the donor vessels, those of the recipient or both. Renal artery thrombosis usually occurs early post transplant, but is uncommon with an incidence of less than 1%. It typically results in graft loss. It usually occurs as a result of a technical problem such a vessel torsion or sub intimal flaps. The usual presenting feature is a sudden cessation of urine output. When suspected, the occlusion is usually well demonstrated with duplex scanning. Ideally immediate surgical re-exploration should occur. Sadly, the graft has usually been lost by this stage and will require graft nephrectomy. Renal vein thrombosis is not as common as arterial graft thrombosis and the usual presenting features include discomfort at the graft site and swelling of the graft associated with loss of urine output. Again, duplex scanning is indicated. Unfortunately, this complication is also associated with a high incidence of graft loss. Over a longer time frame (typically months) some individuals will develop renal artery stenosis. These individuals will typically develop hypertension and over time graft function will decline as hypertensive nephropathy occurs. It is usually demonstrated by duplex scanning and is usually amenable to endovascular intervention. Urological complications Urinary tract complications manifesting as leakage or obstruction are common complications following renal transplantation and occur in up to 10% of patients. The main underlying cause is the relatively poor blood supply to the transplanted ureter. Patients typically present relatively early in the first 5 weeks following transplantation with pain and swelling at the graft site. Imaging with USS is often the initial test. Therapeutic options include surgical re-implantation of the ureter for large leaks and stent insertion and nephrostomy placement for smaller leaks. Lymphocele These do not generally occur until 2 weeks or longer after surgery. They are, however, relatively common and may be seen in up to 18% of patients. Symptoms usually occur as a result of mass effect with compression of adjacent structures. These include the vessels supplying both the graft, with deterioration in graft function, the ureter, with alteration in urine output and the recipients lower limb vessels, with development of leg swelling. Creation of a laparoscopic or open peritoneal window is a favored treatment. Rejection Four types of graft rejection are recognised; hyperacute, accelerated acute, acute and chronic. Type of rejection Key features Hyperacute Occurs within minutes of clamp release Due to pre formed antibodies Immediate loss of graft occurs Accelerated acute Occurs in first few days following surgery Involved both cellular and antibody mediated injury Pre-sensitisation of the donor is a common cause Acute Traditionally the most common type of rejection Seen days to weeks after surgery Predominantly a cell mediated process mediated by lymphocytes Organ biopsy demonstrates cellular infiltrates and graft cell apoptosis Chronic Increasingly common problem Typically; graft atrophy and atherosclerosis are seen. Fibrosis often occurs as a late event

Answer 276

Lymphocele Swelling over the graft site is often due to a lymphocele and this is further suggested by the normal renal function. They cause symptoms through mass effect and limb swelling may occur. Treatment is often surgical.

Answer 277

In a normally distributed sample, the mean, median and mode are the same.

Answer 278

Cowden disease PTEN is a tumour supressor gene and loss of function mutations result in up regulation of the mTOR pathway.

Answer 279

The correct answer is A. Peutz-Jeghers syndrome. Explanation: Peutz-Jeghers syndrome is a genetic condition characterized by multiple intestinal hamartomatous polyps and distinctive mucocutaneous pigmentation, typically around the mouth, lips, and sometimes on the fingers and toes. It is caused by mutations in the STK11 (LKB1) gene. Patients with this syndrome are also at an increased risk of developing certain types of cancer, including gastrointestinal, pancreatic, and breast cancer. Other options: • B. Cowden disease: Associated with multiple hamartomas but not pigmentation around the mouth. • C. Familial adenomatous polyposis coli: Causes numerous adenomatous polyps in the colon and a high risk of colorectal cancer, but lacks pigmentation features. • D. Lynch syndrome: A hereditary cancer syndrome, primarily increasing the risk for colorectal and endometrial cancer, without hamartomas or pigmentation. • E. MYH-associated polyposis: Associated with polyps and colorectal cancer but no pigmentation.

Answer 280

**Answer: D. Lynch syndrome** **Explanation:** The clinical scenario aligns with **Lynch syndrome (Hereditary Nonpolyposis Colorectal Cancer, HNPCC)** due to the following key features: 1. **Early-onset colorectal cancer** (age 28) with **mucinous histology**, which is characteristic of Lynch syndrome. 2. **Right-sided tumor location** (cecum), common in Lynch syndrome. 3. **Scanty polyps**, as Lynch is not associated with polyposis (unlike FAP or MAP). 4. **Autosomal dominant inheritance** suggested by the father’s early death from colorectal cancer at age 34. Lynch syndrome is caused by germline mutations in mismatch repair genes (e.g., *MLH1*, *MSH2*), leading to microsatellite instability and increased risk of colorectal, endometrial, and other cancers. The absence of extensive polyposis and the mucinous carcinoma strongly differentiate this from polyposis syndromes (FAP/MAP) or hamartomatous syndromes (Peutz-Jeghers, Cowden). **Exclusion of Other Options:** - **A. Peutz-Jeghers syndrome**: Hamartomatous polyps (not adenomas) and mucocutaneous pigmentation; typically small bowel polyps. - **B. Cowden disease**: PTEN mutations, hamartomas, and non-colonic cancers (breast, thyroid). - **C. FAP**: Hundreds to thousands of adenomas; mucinous carcinoma is rare. - **E. MYH-associated polyposis**: Autosomal recessive, attenuated polyposis; less likely given the dominant family history. **Conclusion:** Lynch syndrome is the most likely diagnosis given the clinical and familial features.

Answer 281

The treatment of colorectal liver metastasis is usually with chemotherapy followed by surgical resection. Where surgery is performed for liver metastasis with curative intent, the 5 year survival is 20%. Palliation would generally only be considered if the patient were frail or widespread disease found on imaging. Radiotherapy is not part of the treatment of liver metastasis. Colorectal cancer treatment Patients diagnosed as having colorectal cancer should be completely staged using CT of the chest/ abdomen and pelvis. Their entire colon should have been evaluated with colonoscopy or CT colonography. Patients whose tumours lie below the peritoneal reflection should have their mesorectum evaluated with MRI. Once their staging is complete patients should be discussed within a dedicated colorectal MDT meeting and a treatment plan formulated. Treatment of colonic cancer Cancer of the colon is nearly always treated with surgery. Stents, surgical bypass and diversion stomas may all be used as palliative adjuncts. Resectional surgery is the only option for cure in patients with colon cancer. The procedure is tailored to the patient and the tumour location. The lymphatic drainage of the colon follows the arterial supply and therefore most resections are tailored around the resection of particular lymphatic chains (e.g. ileo-colic pedicle for right sided tumours). Some patients may have confounding factors that will govern the choice of procedure, for example a tumour in a patient from a HNPCC family may be better served with a panproctocolectomy rather than segmental resection. Following resection the decision has to be made regarding restoration of continuity. For an anastomosis to heal the key technical factors include; adequate blood supply, mucosal apposition and no tissue tension. Surrounding sepsis, unstable patients and inexperienced surgeons may compromise these key principles and in such circumstances it may be safer to construct an end stoma rather than attempting an anastomosis. When a colonic cancer presents with an obstructing lesion; the options are to either stent it or resect. In modern practice it is unusual to simply defunction a colonic tumour with a proximal loop stoma. This differs from the situation in the rectum (see below). Following resection patients with risk factors for disease recurrence are usually offered chemotherapy, a combination of 5FU and oxaliplatin is common. Rectal cancer The management of rectal cancer is slightly different to that of colonic cancer. This reflects the rectum's anatomical location and the challenges posed as a result. Tumours located in the rectum can be surgically resected with either an anterior resection or an abdomino - perineal resection. The technical aspects governing the choice between these two procedures can be complex to appreciate and the main point to appreciate for the MRCS is that involvement of the sphincter complex or very low tumours require APER. In the rectum a 2cm distal clearance margin is required and this may also impact on the procedure chosen. In addition to excision of the rectal tube an integral part of the procedure is a meticulous dissection of the mesorectal fat and lymph nodes (total mesorectal excision/ TME). In rectal cancer surgery invovlement of the cirumferential resection margin carries a high risk of disease recurrence. Because the rectum is an extraperitoneal structure (until you remove it that is!) it is possible to irradiate it, something which cannot be offered for colonic tumours. This has a major impact in rectal cancer treatment and many patients will be offered neoadjuvent radiotherapy (both long and short course) prior to resectional surgery. Patients with T1, 2 and 3 /N0 disease on imaging do not require irradiation and should proceed straight to surgery. Patients with T4 disease will typically have long course chemo radiotherapy. Patients presenting with large bowel obstruction from rectal cancer should not undergo resectional surgery without staging as primary treatment (very different from colonic cancer). This is because rectal surgery is more technically demanding, the anastomotic leak rate is higher and the danger of a positive resection margin in an unstaged patient is high. Therefore patients with obstructing rectal cancer should have a defunctioning loop colostomy. Summary of procedures The operations for cancer are segmental resections based on blood supply and lymphatic drainage. These commonly performed procedures are core knowledge for the MRCS and should be understood. Site of cancer Type of resection Anastomosis Risk of leak Right colon Right hemicolectomy Ileo-colic Low <5% Transverse Extended right hemicolectomy Ileo-colic Low <5% Splenic flexure Extended right hemicolectomy Ileo-colic Low <5% Splenic flexure Left hemicolectomy Colo-colon 2-5% Left colon Left hemicolectomy Colo-colon 2-5% Sigmoid colon High anterior resection Colo-rectal 5% Upper rectum Anterior resection (TME) Colo-rectal 5% Low rectum Anterior resection (Low TME) Colo-rectal (+/- Defunctioning stoma) 10% Anal verge Abdomino-perineal excision of colon and rectum None n/a In the emergency setting, where the bowel has perforated, the risk of an anastomotic breakdown is much greater, particularly when the anastomosis is colon-colon. In this situation, an end colostomy is often safer and can be reversed later. When resection of the sigmoid colon is performed and an end colostomy is fashioned the operation is referred to as a Hartmans procedure. Whilst left sided resections are more risky, ileo-colic anastomoses are relatively safe even in the emergency setting and do not need to be defunctioned. References A review of the diagnosis and management of colorectal cancer and a summary of the UK National Institute of Clinical Excellence guidelines is provided in: NICE Guideline NG151. Last updated in 2020.

Answer 282

The non-characteristic features of central chemoreceptors in the control of ventilation are: **They are stimulated primarily by venous hypercapnia** Central chemoreceptors respond to **arterial** CO₂ levels indirectly via changes in cerebrospinal fluid (CSF) pH, not venous hypercapnia. Venous blood typically has higher CO₂ levels, but central chemoreceptors are influenced by arterial CO₂ crossing the blood-brain barrier and altering CSF pH. Venous hypercapnia is not their primary stimulus. **Explanation of Other Options:** - **Located in the medulla oblongata**: Correct. Central chemoreceptors are situated in the medulla. - **Relatively insensitive to hypoxia**: Correct. Central chemoreceptors respond weakly to low oxygen; peripheral chemoreceptors (carotid/aortic bodies) detect hypoxia. - **Affected by CSF pH**: Correct. Their activation depends on CO₂-induced pH changes in the CSF. - **Carotid receptors stimulated first during acute hypercapnia**: Correct. Peripheral chemoreceptors (carotid bodies) detect rapid changes in arterial CO₂ before central chemoreceptors, which have a slower response due to CSF dynamics. **Final Answer:** The statement **"They are stimulated primarily by venous hypercapnia"** is not characteristic of central chemoreceptors.

Answer 283

The most likely process causing the rapid graft failure in this scenario is **hyperacute rejection**, mediated by pre-existing antibodies in the recipient. Here's the breakdown: 1. **Key Mechanism**: Hyperacute rejection occurs within minutes to hours due to pre-existing antibodies in the recipient that bind to donor antigens, triggering complement activation, endothelial damage, and thrombosis. ABO incompatibility is a common cause, but the question specifies ABO matching, so the culprit must be non-ABO antibodies. 2. **Antibody Type**: - **IgG antibodies** are typically involved in hyperacute rejection because they result from prior sensitization (e.g., previous transplants, blood transfusions, pregnancies). IgG activates complement more effectively than IgM, leading to rapid tissue destruction. - **IgM antibodies** are usually part of a primary immune response (e.g., ABO incompatibility) and are less likely to cause hyperacute rejection in this context. 3. **HLA Class I vs. Class II**: - **HLA Class I** is expressed on all nucleated cells, including the endothelial cells of the transplanted kidney, making them a prime target for antibody-mediated damage. - **HLA Class II** is primarily on antigen-presenting cells and less relevant in hyperacute rejection. 4. **Eliminating Options**: - **C and D** (donor antibodies) are incorrect because the donor’s antibodies do not attack the recipient’s immune system. - **E** (IgM anti-HLA Class II) is unlikely because IgM is not typically associated with prior sensitization, and Class II is less critical here. - **B** (IgM anti-HLA Class I) is less probable as HLA antibodies are not "natural" like ABO antibodies; they develop after exposure, which would lead to IgG production. **Conclusion**: The rapid graft failure is most likely due to **IgG anti-HLA Class I antibodies in the recipient (A)**, reflecting prior sensitization and a classic hyperacute rejection mechanism. **Answer**: **A. IgG anti HLA Class I antibodies in the recipient**

Answer 284

**Answer: D. Ligamentum flavum** **Explanation:** During a **posterior surgical approach** (e.g., laminectomy), the sequence of structures encountered includes: 1. **Supraspinous ligament** (connects spinous process tips posteriorly). 2. **Interspinous ligament** (between adjacent spinous processes). 3. **Ligamentum flavum** (located **anterior to the spinous processes** and laminae, bridging adjacent vertebral arches). The **ligamentum flavum** is a thick, elastic, yellow ligament that forms the posterior wall of the spinal canal. Surgeons must pierce this ligament to access the epidural space and spinal canal. It lies directly anterior to the laminae and spinous processes, consistent with the description in the question. **Exclusion of Other Options:** - **A. Transverse spinal ligament**: Not a standard spinal ligament; possibly confused with the transverse ligament of the atlas (C1), irrelevant here. - **B. Supraspinous ligament**: Lies **posterior** to the spinous processes, not anterior. - **C. Anterior longitudinal ligament**: Located on the **anterior surface** of the vertebral bodies, inaccessible via a posterior approach. - **E. Posterior longitudinal ligament**: Runs along the **posterior vertebral bodies inside the spinal canal**, deeper than the ligamentum flavum. **Conclusion:** The **ligamentum flavum** is the tough ligamentous structure encountered anterior to the spinous processes during a posterior spinal approach.

Answer 285

Based on the description of the radiolucent lesion in the head of the humerus extending to the subchondral plate, the most likely diagnosis is: F. Giant cell tumour Giant cell tumors (GCTs) are benign but locally aggressive neoplasms that typically occur in the epiphyseal region of long bones, such as the humerus. They often present with pain and swelling, and radiographs show a characteristic "soap bubble" appearance with a well-defined margin and extension to the subchondral plate. Other options are less likely: A. Osteosarcoma: Typically presents with a mixed lytic and blastic lesion, and is more common in younger patients. B. Osteomalacia: Characterized by softening of bones due to vitamin D deficiency, and typically presents with diffuse bone pain and muscle weakness. C. Osteoporosis: Characterized by diffuse bone loss, and typically presents with vertebral compression fractures or hip fractures in older patients. D. Metastatic carcinoma: Typically presents with multiple lytic lesions in various bones, and is more common in older patients. E. Osteoblastoma: A rare benign tumor that typically presents with a small, well-defined lytic lesion in the spine or long bones. G. Ewing’s sarcoma: A malignant tumor that typically presents with a permeative lytic lesion and a large soft tissue mass, and is more common in younger patients.

Answer 286

The most likely diagnosis for a 72-year-old woman with a lumbar vertebral crush fracture, hypocalcemia, and low urinary calcium is **B. Osteomalacia**. ### Explanation: 1. **Hypocalcemia and low urinary calcium**: These findings suggest a defect in calcium metabolism, which is often seen in osteomalacia due to vitamin D deficiency or impaired phosphate metabolism. This leads to inadequate bone mineralization. 2. **Vertebral crush fracture**: While osteoporosis (C) is a common cause of vertebral fractures in elderly women, the presence of hypocalcemia and low urinary calcium points more toward osteomalacia, which is characterized by defective bone mineralization rather than just low bone density. ### Why not the other options? - **A. Osteosarcoma** and **E. Osteoblastoma**: These are bone tumors and are not typically associated with hypocalcemia or low urinary calcium. - **C. Osteoporosis**: While osteoporosis can cause vertebral fractures, it is not typically associated with hypocalcemia or low urinary calcium. - **D. Metastatic carcinoma**: This can cause bone fractures, but it is not associated with hypocalcemia or low urinary calcium unless there is widespread bone destruction, which would typically present with hypercalcemia. - **F. Giant cell tumor** and **G. Ewing’s sarcoma**: These are bone tumors and are not associated with hypocalcemia or low urinary calcium. Thus, **B. Osteomalacia** is the most appropriate diagnosis in this clinical scenario.

Answer 287

The most likely diagnosis for the 16-year-old boy with a pelvic fracture, a lytic lesion, and "onion-type" periosteal reaction is **G. Ewing’s sarcoma**. ### Key Points: 1. **Clinical Context**: - Age: **Adolescents** are the typical demographic for Ewing’s sarcoma. - Mechanism: Pathologic fracture after **minor trauma** (kicking a football) suggests underlying bone weakness from a tumor. 2. **Imaging Findings**: - **Lytic lesion**: Indicates bone destruction. - **"Onion-type" (lamellated) periosteal reaction**: Classic radiographic feature of Ewing’s sarcoma, caused by layers of reactive bone formation in response to tumor growth. 3. **Why Not Other Options**: - **A. Osteosarcoma**: More common around the knee, with a "sunburst" periosteal reaction. Pelvic involvement is less typical. - **B. Osteomalacia/C. Osteoporosis**: Metabolic bone diseases causing diffuse bone weakness, not focal lytic lesions with aggressive periosteal reactions. - **D. Metastatic carcinoma**: Rare in teenagers without a known primary cancer; periosteal reaction is atypical. - **E. Osteoblastoma/F. Giant cell tumor**: Benign tumors with less aggressive imaging features (e.g., sclerotic rim or "soap bubble" appearance). ### Conclusion: The combination of age, pathologic fracture, lytic lesion, and classic "onion-skin" periosteal reaction strongly supports **Ewing’s sarcoma**. Biopsy and further imaging (MRI, PET-CT) would confirm the diagnosis.

Answer 288

The cell of origin in virtually all pancreatic carcinomas is **the ductular epithelium**. ### Explanation: - **Pancreatic ductal adenocarcinoma (PDAC)**: This is the most common type of pancreatic cancer, accounting for about 90% of cases. It arises from the **ductular epithelium** of the pancreatic ducts. - **Other cell types**: - **Acinar cells**: These cells produce digestive enzymes and are the origin of rare pancreatic tumors like acinar cell carcinoma. - **Islet beta cells** and **alpha cells**: These are part of the endocrine pancreas and give rise to neuroendocrine tumors (e.g., insulinomas, glucagonomas), which are distinct from pancreatic ductal adenocarcinoma. - **Interstitial fibroblasts**: These are stromal cells and are not the origin of pancreatic carcinomas. ### Conclusion: The vast majority of pancreatic carcinomas arise from **the ductular epithelium**, making this the correct answer.

Answer 289

Mnemonic for the nerves passing through the supraorbital fissure: Live Frankly To See Absolutely No Insult Lacrimal Frontal Trochlear Superior Division of Oculomotor Abducens Nasociliary Inferior Division of Oculomotor nerve The opthalmic artery arises from the internal carotid immediately after it has pierced the dura and arachnoid. It runs through the optic canal below the optic nerve and within its dural and arachnoid sheaths. It terminates as the supratrochlear and dorsal nasal arteries

Answer 290

The most likely culprit vessel for postoperative hemorrhage following a tonsillectomy is the **B) External palatine vein**. ### Explanation: 1. **Tonsillectomy Anatomy**: - The **external palatine vein** (also known as the paratonsillar vein) is located in the **paratonsillar space**, near the lower pole of the tonsil. It is a common source of bleeding during or after tonsillectomy. - This vein is vulnerable to injury during dissection of the tonsillar bed, especially if the tonsillar capsule is not adequately preserved. 2. **Why Not Other Options**: - **A) Facial vein**: This is not directly related to the tonsillar bed and is unlikely to be the source of hemorrhage. - **C) External carotid artery**: While the tonsillar branches of the external carotid artery supply the tonsils, significant arterial bleeding would be more dramatic and less likely to occur in the recovery phase. - **D) Internal jugular vein**: This is a deep structure and not typically involved in tonsillectomy-related bleeding. - **E) None of the above**: The external palatine vein is a well-known source of post-tonsillectomy hemorrhage. ### Conclusion: The **external palatine vein** is the most likely vessel responsible for postoperative hemorrhage in this case. Management includes prompt recognition, pressure application, and surgical intervention if necessary.

Answer 291

The correct answer is 1% xylocaine with 1 in 200,000 adrenaline Historically cocaine was popular for the management of epistaxis. Some surgeons will still routinely use cocaine paste for this indication. Its popularity stems from the fact that it causes vasospasm. However, systemic absorption carries the risk of adverse reactions. Where it is used the correct dose is 4%. Topically applied short acting local anaesthetic agents with adrenaline may produce similar effects, with lower risks of toxicity.

Answer 292

The correct answer is 1% Lignocaine This is excision of the toe nail and a fast acting local anaesthetic is indicated. Adrenaline should be avoided in this setting as it can cause digital ischaemia

Answer 293

The correct choice for a Biers Block (intravenous regional anesthesia) to facilitate the reduction of a distal radius fracture is: **E. Prilocaine 1%** ### Explanation: - **Prilocaine 1%** is the preferred local anesthetic for intravenous regional anesthesia (Biers Block) due to its favorable safety profile, including a lower risk of systemic toxicity compared to other local anesthetics. - It has a rapid onset and provides adequate anesthesia for the duration of the procedure. - Prilocaine is metabolized to o-toluidine, which can cause methemoglobinemia in high doses, but this is rare at the doses used for Biers Block. ### Why not the others? - **A. 1% Xylocaine with 1 in 200,000 adrenaline**: Adrenaline is contraindicated in intravenous regional anesthesia because it can cause severe vasoconstriction and ischemia. - **B. 1% Lignocaine (Lidocaine)**: Lidocaine can be used, but it has a higher risk of systemic toxicity compared to prilocaine. - **C. 0.5% Bupivacaine with 1 in 200,000 adrenaline**: Bupivacaine is contraindicated due to its high cardiotoxicity if accidentally released systemically. - **D. 0.5% Bupivacaine**: Same as above; bupivacaine is not safe for Biers Block. - **F. Procaine 1%**: Procaine is not commonly used for Biers Block due to its slower onset and shorter duration. - **G. Cocaine 25% and H. Cocaine 10%**: Cocaine is not used for Biers Block due to its high toxicity and potential for severe adverse effects. Thus, **Prilocaine 1%** is the safest and most appropriate choice for this procedure.

Answer 294

The branches of the lower molar and premolar teeth are supplied by branches of the inferior alveolar nerve. Those of the canine and incisors by the incisive branch of the same nerve. The gingiva and supporting structures are innervated by the lingual nerve. Trigeminal nerve The trigeminal nerve is the main sensory nerve of the head. In addition to its major sensory role, it also innervates the muscles of mastication. Distribution of the trigeminal nerve Sensory Scalp Face Oral cavity (and teeth) Nose and sinuses Dura mater Motor Muscles of mastication Mylohyoid Anterior belly of digastric Tensor tympani Tensor palati Autonomic connections (ganglia) Ciliary Sphenopalatine Otic Submandibular Path Originates at the pons Sensory root forms the large, crescentic trigeminal ganglion within Meckel's cave, and contains the cell bodies of incoming sensory nerve fibres. Here the 3 branches exit. The motor root cell bodies are in the pons and the motor fibres are distributed via the mandibular nerve. The motor root is not part of the trigeminal ganglion. Branches of the trigeminal nerve Ophthalmic nerve Sensory only Maxillary nerve Sensory only Mandibular nerve Sensory and motor Sensory Ophthalmic Exits skull via the superior orbital fissure Sensation of: scalp and forehead, the upper eyelid, the conjunctiva and cornea of the eye, the nose (including the tip of the nose, except alae nasi), the nasal mucosa, the frontal sinuses, and parts of the meninges (the dura and blood vessels). Maxillary nerve Exit skull via the foramen rotundum Sensation: lower eyelid and cheek, the nares and upper lip, the upper teeth and gums, the nasal mucosa, the palate and roof of the pharynx, the maxillary, ethmoid and sphenoid sinuses, and parts of the meninges. Mandibular nerve Exit skull via the foramen ovale Sensation: lower lip, the lower teeth and gums, the chin and jaw (except the angle of the jaw), parts of the external ear, and parts of the meninges. Motor Distributed via the mandibular nerve. The following muscles of mastication are innervated: Masseter Temporalis Medial pterygoid Lateral pterygoid Other muscles innervated include: Tensor veli palatini Mylohyoid Anterior belly of digastric Tensor tympani

Answer 295

The anesthetic agent most likely to induce **adrenal suppression** is: **Etomidate** ### Explanation: - **Etomidate** is known to inhibit the enzyme **11β-hydroxylase** in the adrenal cortex, which is essential for the synthesis of cortisol and other corticosteroids. This suppression can occur even after a single dose and may last for several hours to days, depending on the duration of exposure. - Adrenal suppression by etomidate can lead to reduced cortisol levels, which may be clinically significant, especially in critically ill patients or those with pre-existing adrenal insufficiency. ### Why not the others? - **Sodium thiopentone**: Does not have a significant effect on adrenal function. - **Midazolam**: A benzodiazepine with no known impact on adrenal suppression. - **Propofol**: Does not affect adrenal steroidogenesis. - **Ketamine**: Stimulates the sympathetic nervous system but does not cause adrenal suppression. Thus, **etomidate** is the most likely anesthetic agent to induce adrenal suppression.

Answer 296

### Correct Answer: **C. Propofol** ### Explanation: - **Propofol** is characterised by a rapid onset of anaesthesia, pain on injection (which can be mitigated by lidocaine pretreatment), and rapid metabolism with little accumulation, making it suitable for repeated dosing or infusions. - It has **antiemetic properties**, which are particularly beneficial for day-case surgery and procedures with a high risk of postoperative nausea and vomiting. - Propofol causes **moderate myocardial depression**, leading to a decrease in blood pressure, which must be carefully managed, especially in hypovolaemic or critically ill patients. - It is widely used for **maintaining sedation in ITU**, **total intravenous anaesthesia (TIVA)**, and **day-case surgery** due to its favourable pharmacokinetic profile. ### Why not the others? - **A. Thiopentone**: Rapid onset but lacks antiemetic properties and is not commonly used for infusions or sedation in ITU due to its long context-sensitive half-life. - **B. Ketamine**: Does not cause myocardial depression (it stimulates the cardiovascular system) and is not typically used for day-case surgery or sedation in ITU. - **D. Etomidate**: Rapid onset but lacks antiemetic properties and is associated with adrenal suppression, limiting its use for infusions. - **E. Midazolam**: Slower onset of action, no antiemetic properties, and is not the first choice for TIVA or day-case surgery. Thus, **Propofol** is the most appropriate agent described in the question.

Answer 297

### Correct Answer: **B. Thiopentone (Thiopental)** ### Explanation: - **Thiopentone** is a barbiturate with an **extremely rapid onset of action**, making it ideal for **rapid sequence induction (RSI)**. - It causes **marked myocardial depression**, which can lead to significant hypotension, especially in hypovolaemic or critically ill patients. - Thiopentone is metabolised in the liver, and its **active metabolites can accumulate quickly**, making it unsuitable for prolonged infusions or maintenance of anaesthesia. - It has **little to no analgesic properties**, meaning additional analgesics are required for pain management. ### Why not the others? - **A. Propofol**: Rapid onset but is suitable for maintenance infusions and has some analgesic properties. - **C. Ketamine**: Rapid onset but does not cause myocardial depression (it stimulates the cardiovascular system) and has strong analgesic effects. - **D. Etomidate**: Rapid onset but does not cause significant myocardial depression and is not associated with metabolite accumulation. - **E. Midazolam**: Slower onset of action and is not typically used for RSI. Thus, **Thiopentone (Thiopental)** is the most appropriate agent described in the question.

Answer 298

### Correct Answer: **C. Ketamine** ### Explanation: - **Ketamine** is a unique intravenous anaesthetic agent that can be used for **induction of anaesthesia**. - It has **moderate to strong analgesic properties**, making it useful for painful procedures. - Ketamine causes **little myocardial depression** and often stimulates the cardiovascular system, making it an excellent choice for **haemodynamically unstable patients**. - It induces a state of **dissociative anaesthesia**, characterised by profound analgesia and amnesia, but patients may experience **nightmares, hallucinations, or vivid dreams** during recovery. ### Why not the others? - **A. Propofol**: Lacks analgesic properties and can cause significant myocardial depression. - **B. Thiopentone (Thiopental)**: Causes marked myocardial depression and has no analgesic properties. - **D. Etomidate**: Does not provide analgesia and is not associated with dissociative anaesthesia. - **E. Midazolam**: Lacks analgesic properties and is not typically used for induction in haemodynamically unstable patients. Thus, **Ketamine** is the most appropriate agent described in the question.

Answer 299

### Correct Answer: **D. Etomidate** ### Explanation: - **Etomidate** is known for its **favourable cardiac safety profile**, causing minimal haemodynamic instability, making it suitable for patients with cardiovascular disease. - It has **no analgesic properties**, so additional analgesics are required for pain management. - Etomidate is **unsuitable for maintaining sedation** because even a single dose can inhibit adrenal steroidogenesis, leading to **adrenal suppression**. - **Postoperative nausea and vomiting (PONV)** are common side effects of etomidate. ### Why not the others? - **A. Propofol**: Has some analgesic properties and is commonly used for maintaining sedation. It does not cause adrenal suppression. - **B. Thiopentone (Thiopental)**: Causes significant myocardial depression and is not associated with adrenal suppression. - **C. Ketamine**: Has strong analgesic properties and does not cause adrenal suppression. - **E. Midazolam**: Lacks analgesic properties but does not cause adrenal suppression and is not typically associated with PONV. Thus, **Etomidate** is the most appropriate agent described in the question.

Answer 300

Papillary carcinoma The presence of papillary structures together with the cytoplasmic features described is strongly suggestive of papillary carcinoma. They are seldom encapsulated.

Answer 301

Hashimotos thyroiditis Lymphocytic infiltrates and fibrosis are typically seen in Hashimotos thyroiditis. In Lymphoma only dense lymphatic type tissue is usually present.

Answer 302

Total abdominal ultrasound scan This patient has risk factors for a wound infection which is not in itself an indication for scanning. However, he also had abdominal distension and this, together with the history of distension would generally attract a recommendation for imaging. A USS will show an abdominal wall collection and more importantly any phrenic or pelvic collections. Unlike adult practice, CT scanning is rarely performed in children.

Answer 303

Abdominal CT scan with oral and IV contrast This would most likely be the result of an anastomotic leak with abscess formation. Detailed imaging is required to allow accurate diagnosis and planning of management.

Answer 304

ERCP The most likely cause of a bile leak in this scenario would be a dislodged clip from the cystic duct. Whilst it may be tempting to try and plan to manage this surgically the anatomy is often unfavorable and the duct very difficult to identify. An ERCP has the advantage of demonstrating the cause of the leak and allowing placement of a stent. This will usually allow the resolution of most leaks without the need for surgery.

Answer 305

Memory aid: T8 (8 letters) = vena cava T10 (10 letters) = oesophagus T12 (12 letters) = aortic hiatus

Answer 306

The correct answer is Superior gluteal nerve. Damage to the superior gluteal nerve results in weakness of the gluteus medius and gluteus minimus muscles, which are responsible for thigh abduction. This leads to a Trendelenburg gait, where the pelvis dips on the opposite side when the patient stands on the affected leg. The patient compensates by adopting a waddling gait to maintain balance. The presence of buttock muscle wasting further supports the diagnosis of superior gluteal nerve injury

Answer 307

The correct answer is Atenolol. Explanation: • Gastrin: Stimulates insulin release indirectly by promoting gastric acid secretion and subsequent nutrient absorption. • Protein: Ingested proteins stimulate insulin secretion through amino acids such as leucine and arginine. • Secretin: Enhances insulin release by promoting bicarbonate secretion and facilitating nutrient absorption. • Vagal cholinergic action: Stimulates insulin release via parasympathetic activation (mediated by acetylcholine). • Atenolol: A β-blocker that inhibits insulin secretion by blocking β2-adrenergic receptors in pancreatic beta cells. Thus, atenolol does not stimulate insulin release and may even suppress it, potentially leading to hypoglycaemic unawareness in diabetic patients. Beta adrenergic drugs

Answer 308

During a radical neck dissection, division of the carotid sheath will expose the ansa cervicalis. This is because: 1. The ansa cervicalis is formed by the ventral rami of C1-C3 spinal nerves 2. It lies within or closely associated with the carotid sheath, anterior to the internal jugular vein 3. The carotid sheath contains three main structures: - Internal jugular vein - Common carotid artery - Vagus nerve The other options are incorrect because: - Pretracheal fascia: Surrounds the trachea and thyroid gland - Prevertebral fascia: Covers the vertebral bodies and deep neck muscles - Investing layer (deep cervical fascia): Most superficial layer, encircles the neck - Sibson's fascia: A dome-shaped fascia over the apex of the lung Therefore, the correct answer is "Carotid sheath."

Answer 309

All of the above. Rule of 10s in phaeochromocytoma

Answer 310

Scaphoid fractures in children are rare, will usually involve the distal pole and are easily missed. The initial clinical examination (and sometimes x-rays) may be normal and repeated clinical examination and imaging is advised for this reason. Whilst the other injuries may be sustained from a fall onto an outstretched hand they are less likely to be overlooked on clinical examination. In the case of a Bennetts fracture, the injury mechanism is less compatible with this type of injury.

Answer 311

S2, 3, 4 Keeps the poo off the floor The external anal sphincter is innervated by the inferior rectal branch of the pudendal nerve, this has root values of S2, 3 and the perineal branch of S4.

Answer 312

The structure most likely to be injured in this scenario is the **ulnar artery**. ### Explanation: - The **pisiform bone** is located on the ulnar side of the wrist, and the injury is described as being immediately lateral to it. This places the injury in the hypothenar region of the hand, which is supplied by the ulnar nerve and artery. - The **ulnar artery** runs in close proximity to the pisiform bone, passing through Guyon's canal (a space between the pisiform and the hook of the hamate). It is vulnerable to injury in this area. - The other structures listed are less likely to be injured: - The **palmar cutaneous branch of the median nerve** is located more radially and superficially, not in the immediate vicinity of the pisiform. - The **lateral tendons of the flexor digitorum superficialis** and **profundus** are located more centrally in the palm and are not typically near the pisiform. - The **flexor carpi radialis tendons** are located on the radial side of the wrist and are not near the pisiform. Thus, the **ulnar artery** is the most likely structure to be injured in this case.

Answer 313

The correct answer is: E. Abducens nerve (Cranial Nerve VI) Explanation: This patient presents with signs of raised intracranial pressure (ICP), including: • Severe headache • Nausea • Recent epileptic fit • Papilloedema on fundoscopy • Diplopia (double vision) Among the cranial nerves, the abducens nerve (CN VI) is the most vulnerable to raised ICP because it has a long intracranial course and is easily compressed. Compression leads to lateral rectus palsy, causing horizontal diplopia, which worsens when looking to the affected side. Why not the others? • A. Optic nerve (CN II) → Can be affected in raised ICP (causing papilloedema), but it does not cause diplopia. • B. Oculomotor nerve (CN III) → A lesion would cause ptosis, pupil dilation (mydriasis), and eye deviation down and out rather than simple horizontal diplopia. • C. Trigeminal nerve (CN V) → Responsible for facial sensation and mastication, not eye movement. • D. Facial nerve (CN VII) → Causes facial palsy, not diplopia. • F. Glossopharyngeal nerve (CN IX) → Involved in swallowing and taste, not eye movement. • G. Vestibulocochlear nerve (CN VIII) → Causes vertigo and hearing loss, not diplopia. • H. Accessory nerve (CN XI) → Controls the sternocleidomastoid and trapezius, unrelated to diplopia. • I. Hypoglossal nerve (CN XII) → Controls tongue movement, unrelated to diplopia. Key Learning Point: Abducens nerve palsy is a classic sign of raised ICP due to its susceptibility to compression.

Answer 314

Glossopharyngeal nerve The glossopharyngeal nerve supplies this area and the ear and otalgia may be the result of referred pain.

Answer 315

Iron is best absorbed from the proximal small bowel (duodenum and jejunum) in the Fe 2+ state. Iron is transported across the small bowel mucosa by a divalent membrane transporter protein (hence the improved absorption of Fe 2+). The intestinal cells typically store the bound iron as ferritin. Cells requiring iron will typically then absorb the complex as needed.

Answer 316

The iliacus lies posterior to the femoral nerve in the femoral triangle. The femoral sheath lies anterior to the iliacus and pectineus muscles.

Answer 317

The most likely diagnosis in this case is Glucagonoma. Explanation: • Glucagonoma is a rare pancreatic neuroendocrine tumour arising from alpha cells, leading to excessive glucagon secretion. • Classic features include: • Necrolytic migratory erythema (NME): A characteristic rash presenting as erythematous blisters with an irregular border, commonly affecting the abdomen and buttocks. • Diabetes mellitus or glucose intolerance: Due to the hyperglycaemic effects of glucagon. • Weight loss: Despite high blood glucose levels, patients experience significant unintentional weight loss. • Diarrhoea: May be present as part of a general systemic effect. This patient’s presentation of diarrhoea, significant weight loss (10 kg), and an erythematous blistering rash strongly suggests glucagonoma . Why not the other options? • Colonic adenocarcinoma: While it can cause weight loss and diarrhoea, it does not typically present with the characteristic skin rash seen in this patient. • Pancreatic adenocarcinoma: Usually associated with painless jaundice and upper abdominal pain rather than the described rash and symptoms. • Tropical sprue: Causes diarrhoea and weight loss but is linked to malabsorption and not necrolytic migratory erythema. • Insulinoma: Presents with episodes of hypoglycaemia (light-headedness, confusion, sweating), not hyperglycaemia or the skin rash seen here. Diagnosis: • Confirmed through serum glucagon levels, imaging (CT/MRI), and biopsy if needed. Glucagonoma is strongly associated with necrolytic migratory erythema.

Answer 318

The most likely vessel responsible for the brisk bleeding in this scenario is the Inferior Vena Cava (IVC). Explanation: • The right adrenal vein is very short and drains directly into the IVC. • When traction is applied to the adrenal gland during an adrenalectomy, this short vein can easily avulse from the IVC, leading to severe bleeding. • This is a well-known complication of right adrenalectomy, requiring careful dissection and often managed with a Satinsky clamp and 6/0 prolene sutures . Why not the other options? • Portal vein: Drains blood from the gastrointestinal tract and spleen; not involved in adrenal venous drainage. • Phrenic vein: Drains the diaphragm and is not the main venous drainage of the adrenal gland. • Right renal vein: The right adrenal vein empties into the IVC, not the renal vein (unlike the left adrenal vein, which drains into the left renal vein). • Superior mesenteric vein: Drains the intestines and is unrelated to adrenal circulation. Key Learning Point: • Left adrenal gland: Drains into the left renal vein. • Right adrenal gland: Drains directly into the IVC via a short vein, making it vulnerable to injury.

Answer 319

The pudendal nerve innervates the posterior vulval area and is routinely blocked in procedures such as episiotomy.

Answer 320

During splenectomy the tail of the pancreas may be damaged. The pancreatic duct will then drain into the splenic bed, amylase is the most likely biochemical finding. Glucagon is not secreted into the pancreatic duct.

Answer 321

Hepatitis A Infective hepatitis is the most likely cause. In the UK, foreign travel is a common cause of developing infectious hepatitis, of which hepatitis A is the most common.

Answer 322

Hepatocellular carcinoma HCC may complicate cirrhosis. AFP is often raised in HCC.

Answer 323

Bile duct stones Bile salts are absorbed in the terminal ileum. When this process is impaired as in Crohns the patient may develop gallstones, if these pass into the CBD then obstructive jaundice will result.

Answer 324

Beware of damaging the thoracodorsal trunk if a latissimus dorsi flap reconstruction is planned. The thoracodorsal trunk runs through the nodes in the axilla. If injured it may compromise the function and blood supply to latissimus dorsi, which is significant if it is to be used as a flap for a reconstructive procedure.

Answer 325

The correct answer is Inguinal lymph nodes. The lymphatic drainage of the anal canal is determined by its relation to the dentate line: • Above the dentate line: Lymph drains to the internal iliac nodes. • Below the dentate line: Lymph drains to the superficial inguinal nodes. Since this patient’s squamous cell carcinoma is located below the dentate line, it will primarily metastasise to the inguinal lymph nodes .

Answer 326

The patient's presentation of **neuropathic facial pain**, **weakness of the muscles of facial expression** (suggesting facial nerve involvement), and a **hard mass anterior to the external auditory meatus** is highly suggestive of a tumor involving the **parotid gland**. The most likely diagnosis in this case is **adenoid cystic carcinoma**. ### Key Points: 1. **Adenoid cystic carcinoma** is a malignant tumor that often arises in the salivary glands, particularly the parotid gland. It is known for its **perineural invasion**, which can cause neuropathic pain and facial nerve weakness, as seen in this patient. 2. The hard mass anterior to the external auditory meatus is consistent with a parotid gland tumor, as the parotid gland is located in this area. ### Why Not the Other Options? - **Pleomorphic adenoma**: This is the most common benign tumor of the parotid gland. It typically presents as a painless, slow-growing mass and does not cause facial nerve weakness or neuropathic pain unless it undergoes malignant transformation. - **Adenocarcinoma**: This is a rare malignant tumor of the salivary glands. While it can cause facial nerve involvement, it is less commonly associated with neuropathic pain compared to adenoid cystic carcinoma. - **Mucoepidermoid carcinoma**: This is the most common malignant tumor of the parotid gland. It can cause facial nerve involvement, but it is less likely to present with neuropathic pain compared to adenoid cystic carcinoma. - **Lymphoma**: This is a rare cause of parotid gland masses and is less likely to cause neuropathic pain or facial nerve weakness. ### Conclusion: The most likely diagnosis is **adenoid cystic carcinoma** due to the combination of neuropathic pain, facial nerve weakness, and a hard mass in the parotid region. This tumor's propensity for perineural invasion makes it a strong candidate in this clinical scenario.

Answer 327

The correct answer is: Intercalation of DNA. Explanation: Epirubicin is an anthracycline chemotherapy drug used to treat breast cancer. Its primary mode of action is by intercalating into DNA, which disrupts DNA replication and transcription. Additionally, epirubicin inhibits topoisomerase II, an enzyme crucial for DNA unwinding, leading to DNA strand breaks and ultimately cell death. Why not the other options? • Antimetabolite – Drugs like methotrexate or 5-fluorouracil fall under this category; they interfere with DNA synthesis by mimicking nucleotides. • Monoclonal antibody to epidermal growth factor – This describes targeted therapies like trastuzumab (Herceptin), which specifically target HER2 receptors. • Inhibition of DNA gyrase – DNA gyrase is a bacterial enzyme targeted by quinolone antibiotics (e.g., ciprofloxacin), not by cancer drugs. • Inhibition of topoisomerase 1 – Drugs like irinotecan act on topoisomerase I, whereas anthracyclines like epirubicin primarily target topoisomerase II. Thus, intercalation of DNA is the correct mechanism of action for epirubicin.

Answer 328

HPV is associated with: Cervical cancer (HPV 16/18 most common) Anal cancer Penile cancer Vulval cancer Oropharyngeal cancer

Answer 329

99% of males with cystic fibrosis will have absent vas

Answer 330

Carcinoma of the head of the pancreas Carcinoma of the pancreas (Courvoisiers law!). The development of jaundice in association with a smooth right upper quadrant mass is typical of distal biliary obstruction secondary to pancreatic malignancy. A bile duct stricture would not present in this way, all the other choices are related to gallstones and Fitz Hugh Curtis syndrome is a complication of pelvic inflammatory disease.

Answer 331

Mirizzi syndrome In Mirizzi syndrome the gallstone becomes impacted in Hartmans pouch. Episodes of recurrent inflammation occur and this causes compression of the bile duct. In severe cases this then progresses to fistulation. Surgery is extremely difficult as Calots triangle is often completely obliterated and the risks of causing injury to the CBD are high.

Answer 332

Peri hilar lymphadenopathy Unfortunately metastatic disease is the most likely event. Peri hilar lymphadenopathy would be a common culprit.

Answer 333

Seborrhoeic keratosis Seborrhoeic keratosis may have a number of appearances. However, the scaly, thick, greasy surface with scattered keratin plugs makes this the most likely diagnosis.

Answer 334

Dermatofibroma Dermatofibromas may be pigmented and are often larger than they appear. They frequently occur at sites of previous trauma.

Answer 335

The ligament that contains the artery supplying the head of the femur in children is the **Ligamentum teres** (also known as the ligament of the head of the femur). In children, the artery within the ligamentum teres (a branch of the obturator artery) contributes to the blood supply of the femoral head. This is particularly important in pediatric patients because the medial and lateral circumflex arteries, which are the primary blood supply in adults, are not fully developed. The other ligaments listed (transverse ligament, iliofemoral ligament, ischiofemoral ligament, and pubofemoral ligament) do not contain arteries that supply the femoral head.

Answer 336

In epidemiology, the absolute risk reduction, or risk difference is the decrease in risk of a given activity or treatment in relation to a control activity or treatment. It is the inverse of the number needed to treat.

Answer 337

Post splenectomy blood film features: Howell- Jolly bodies Pappenheimer bodies Target cells Irregular contracted erythrocytes As the filtration function is the spleen is no longer present Howell-Jolly bodies are found. The loss of splenic tissue results in the inability to readily remove immature or abnormal red blood cells from the circulation. The red cell count does not alter significantly. However, cytoplasmic inclusions may be seen e.g. Howell-Jolly bodies. In the first few days after splenectomy target cells, siderocytes and reticulocytes will appear in the circulation. Immediately following splenectomy a granulocytosis (mainly composed of neutrophils) is seen, this is replaced by a lymphocytosis and monocytosis over the following weeks. The platelet count is usually increased and this may be persistent, oral antiplatelet agents may be needed in some patients.

Answer 338

BRCA 1 mutation patients are 55% more likely to get ovarian cancer. Those with BRCA 2 are 25% more likely. The risk of developing other malignancies is slightly increased but not to the same extent, and not enough to justify screening.

Answer 339

Formation of autoantibodies against cell surface antigens Mnemonic for the reactions and the mediators involved ACID EGG-T Type 1 Anaphylactic Type 2 Cytotoxic Type 3 Immune complex Type 4 Delayed type EGG T (mediators) IgE IgG IgG T cells Type 2 hypersensitivity reactions (which includes haemolytic anaemia) are associated with formation of antibody against cell surface antigens. Hypersensitivity reactions The Gell and Coombs classification divides hypersensitivity reactions into 4 types Type I Type II Type III Type IV Description Anaphylactic Cytotoxic Immune complex Delayed type Mediator IgE IgG, IgM IgG, Ig A, IgM T-cells Antigen Exogenous Cell surface Soluble Tissues Response time Minutes Hours Hours 2-3 days Examples Asthma Hay fever Autoimmune haemolytic anaemia Pemphigus Goodpasture's Serum sickness SLE Aspergillosis Graft versus host disease Contact dermatitis

Answer 340

Intersphincteric fistulas are the commonest type and the external opening may be internal or external. These are the classical type of fistula and will have an internal opening near the anal verge and obey Goodsalls rule. Primary fistulotomy in this situation usually poses little risk to continence.

Answer 341

The renal veins lie most anteriorly, then artery and ureter lies posteriorly.

Answer 342

The trigeminal nerve is the major sensory nerve to the face except over the angle of the jaw. The angle of the jaw is innervated by the greater auricular nerve.

Answer 343

The interclavicular ligament lies at the upper end of a median sternotomy and is routinely divided to provide access. The pleural reflections are often encountered and should not be intentionally divided, if they are, then a chest drain will need to be inserted on the affected side as collections may then accumulate in the pleural cavity. Other structures encountered include the pectoralis major muscles, again if the incision is truly midline then these should not require formal division. The close relationship of the brachiocephalic vein should be borne in mind and it should be avoided, iatrogenic injury to this structure will result in considerable haemorrhage.

Answer 344

The correct answer is Delayed primary closure Wounds which are contaminated or have the potential to become so are unsafe for immediate primary closure. The combination of diabetes and steroids makes wound complications more likely. Despite his high risk a primary skin graft or flap is unlikely to be a safer option. Either may be used at a later date in the event that delayed primary closure is unsuccessful.

Answer 345

Delayed split thickness skin graft Pretibial lacerations do not heal well. Simple apposition of skin edges almost always fails due to poor quality dermal tissues and underlying haematoma. Debridement of devitalised tissues prior to grafting usually gives the best results.

Answer 346

Compression bandages This is likely to be a venous leg ulcer. These are typically managed using compression bandages. Contra indications to this technique include peripheral vascular disease (not present here).

Answer 347

The artery and vein are separated by scalenus anterior. This muscle runs from the transverse processes of C3,4,5 and 6 to insert onto the scalene tubercle of the first rib.

Answer 348

Beware of ureteric injury in colonic surgery. The inferior mesenteric vein drains into the splenic vein, this point of union lies close to the duodenum and this surgical maneouvre is a recognised cause of ileus.

Answer 349

C The median nerve innervates the 1st and 2nd muscles of the thenar eminence, including the abductor pollicis brevis and opponens pollicis.

Answer 350

E The rounded tendon of the sternocleidomastoid muscle is attached to the upper manubrium sterni.

Answer 351

B Parasympathetic discharge causes erection, while sympathetic discharge causes ejaculation and detumescence.

Answer 352

B The extensor retinaculum is a thickening of the deep fascia that stretches across the back of the wrist and holds the long extensor tendons in position.

Answer 353

A The arterial supply to the adrenal glands includes superior adrenal arteries from the inferior phrenic artery, middle adrenal arteries from the aorta, and inferior adrenal arteries from the renal arteries.

Answer 354

A The knee joint is supplied by the femoral, tibial and common peroneal divisions of the sciatic and by a branch from the obturator nerve.

Answer 355

The clavipectoral fascia is situated under the clavicular portion of pectoralis major. It protects both the axillary vessels and nodes. During an axillary node clearance for breast cancer the clavipectoral fascia is incised and this allows access to the nodal stations. The nodal stations are; level 1 nodes inferior to pectoralis minor, level 2 lie behind it and level 3 above it. During a Patey Mastectomy surgeons divide pectoralis minor to gain access to level 3 nodes. The use of sentinel node biopsy (and stronger assistants!) have made this procedure far less common.

Answer 356

Bounded by latissimus dorsi, pectoralis major, line superior to the nipple and apex at the axilla

Answer 357

Ki 67 is a nuclear proliferation marker (used in immunohistochemistry). Although, Ki67 positivity is a marker of malignancy, it is not itself, an oncogene. Among the options you provided, Ki 67 is not an oncogene 123. Ki 67 is a protein that is expressed in proliferating cells and is used as a marker of cell proliferation 13. It is not a gene that has the potential to cause cancer 13. On the other hand, ras, myc, sis, and erb-B are all oncogenes 14. Ras is a family of genes that encode proteins involved in cell signaling pathways that regulate cell growth and division 14. Mutations in ras genes can cause them to become permanently activated, leading to uncontrolled cell growth and division, and ultimately cancer 14. Myc is a transcription factor that regulates the expression of genes involved in cell growth and division 14. Overexpression of myc can lead to uncontrolled cell growth and division, and ultimately cancer 14. Sis is a gene that encodes a protein called platelet-derived growth factor (PDGF) 14. PDGF is involved in cell growth and division, and overexpression of sis can lead to uncontrolled cell growth and division, and ultimately cancer 14. Erb-B is a gene that encodes a receptor protein involved in cell signaling pathways that regulate cell growth and division 14. Mutations in erb-B can cause the receptor to become permanently activated, leading to uncontrolled cell growth and division, and ultimately cancer 14.

Answer 358

The loss of 500ml (assuming a 70 Kg male) will usually be sufficient to activate the renin angiotensin system. It is unlikely that it would cause any other physiological disturbance.

Answer 359

The vertebral artery passes through the foramina which are located in the transverse processes of the cervical vertebra, it does not traverse the intervertebral foramen. The vertebral artery is a major artery in the neck that supplies blood to the brainstem and cerebellum. It arises from the subclavian artery and enters the transverse foramen of the cervical vertebrae, except for the seventh cervical vertebra (C7) 1. After passing through the transverse foramina of the cervical vertebrae, the vertebral artery ascends posteromedially towards the skull 2. It passes through the foramen magnum, which is a large opening in the occipital bone of the skull that allows the spinal cord to connect with the brain 2. The vertebral artery also passes through the subarachnoid space, which is the space between the arachnoid mater and the pia mater that surrounds the brain and spinal cord 3. However, the vertebral artery does not traverse the intervertebral foramen 45. The intervertebral foramen is the opening between adjacent vertebrae through which spinal nerves exit the spinal cord 6

Answer 360

This patient is likely to have had compartment syndrome (tibial fracture + fasciotomies) which may produce myoglobinuria. The presence of worsening renal function, together with muddy brown casts is strongly suggestive of acute tubular necrosis. Acute interstitial nephritis usually arises from drug toxicity and does not usually produce urinary muddy brown casts. Thin basement membrane disease is an autosomal dominant condition that causes persistent microscopic haematuria, but not worsening renal function.

Answer 361

The azygos vein is routinely divided during an oesophagectomy to allow mobilisation. It arches anteriorly to insert into the SVC on the right hand side.

Answer 362

The modality least likely to be affected by an injury to the inferior trunk of the brachial plexus is: Initiating abduction of the shoulder. Here’s why: The inferior trunk of the brachial plexus is formed by the C8 and T1 nerve roots and primarily contributes to the medial cord, which gives rise to: • Ulnar nerve • Medial root of the median nerve These are responsible for: • Fine motor control of the hand • Flexion of the little finger • Abduction of the fingers (interossei via ulnar nerve) • Sensation of the medial hand (ulnar nerve) So: • Abduction of the fingers → Affected (interossei = ulnar nerve) • Flexion of the little finger → Affected (flexor digiti minimi = ulnar nerve) • Sensation on the palmar aspect of the little finger → Affected (cutaneous branch of ulnar nerve) • Gripping a screwdriver → Affected (requires intrinsic hand muscles, many from ulnar/median nerve) However: • Initiating abduction of the shoulder is done by the supraspinatus muscle, innervated by the suprascapular nerve, which comes from the upper trunk (C5-C6) — not the inferior trunk. Thus, it’s least likely to be affected. Inferior trunk of brachial plexus. C8 and T1 roots Contributes to ulnar nerve and part of median nerve The inferior trunk of the brachial plexus is rarely injured. Nerve roots C8 and T1 are the main contributors to this trunk. Therefore an injury to this site will most consistently affect the ulnar nerve. The inferior trunk also contributes to the median nerve by way of the medial cord and therefore some impairment of grip is almost inevitable. Brachial plexus The brachial plexus extends from the neck to the axilla. It is formed by the ventral rami of the fifth to the eighth cervical nerves with the ascending part of the first thoracic nerve. Location of the plexus The ventral rami which form the plexus enter the lower part of the posterior triangle of the neck in series with the ventral rami of the cervical plexus. The second part of the subclavian artery lies immediately anterior to the lower two rami. The upper three rami intermingle and pass inferolaterally towards the axilla and subclavian artery. They are enclosed within an extension of the prevertebral fascia. In the neck the plexus lies deep to platysma, the supraclavicular nerves, inferior belly of omohyoid and the transverse cervical artery. It then passes deep to the clavicle and the suprascapular vessels, to enter the axilla, and thence surround the second part of the axillary artery Composition of the plexus Ventral rami, the roots of the plexus, lie between scalenus medius and anterior. As they enter the posterior triangle, the upper two (C5,6) and lower two (C8, T1) roots of the plexus unite to form the upper and lower trunks of the plexus respectively. Meanwhile, C7 continues as the middle trunk. The lower trunk may groove the superior surface of the first rib posterior to the subclavian artery, and the root from the first ventral ramus is always in contact with it. Each trunk divides into ventral and dorsal divisions which are destined to supply the anterior (flexor) and posterior (extensor) parts of the upper limb. The cords of the plexus are formed in the axilla. The dorsal divisions unite to form the posterior cord (C5-8). The ventral divisions of the upper and middle trunks unite to form the lateral cord (C5-7), while the ventral divisions of the lower trunk continues as the medial cord (C8-T1). The cords are named according to their relationship to the axillary artery. Each cord terminates by dividing into two main branches at the beginning of the third part of the artery. Sympathetic communications The fifth and sixth cervical ventral rami receive grey rami communicantes from the middle cervical ganglion, while the two or more grey rami communicantes pass from the inferior cervical ganglion to the seventh and eighth cervical ventral rami. The first thoracic ventral ramus receives its grey ramus from the cervicothoracic ganglion. Its for this reason that inferior plexus injury can be complicated by a Horners syndrome. Summary Origin Anterior rami of C5 to T1 Sections of the plexus Roots, trunks, divisions, cords, branches Mnemonic:Real Teenagers Drink Cold Beer Roots Located in the posterior triangle Pass between scalenus anterior and medius Trunks Located posterior to middle third of clavicle Upper and middle trunks related superiorly to the subclavian artery Lower trunk passes over 1st rib posterior to the subclavian artery Divisions Apex of axilla Cords Related to axillary artery

Answer 363

Brown tumors are tumors of bone that arise in settings of excess osteoclast activity, such as hyperparathyroidism, and consist of fibrous tissue, woven bone and supporting vasculature, but no matrix. They are radiolucent on x-ray. The osteoclasts consume the trabecular bone that osteoblasts lay down and this front of reparative bone deposition followed by additional resorption can expand beyond the usual shape of the bone, involving the periosteum thus causing bone pain. They appear brown because haemosiderin is deposited at the site. Primary hyperparathyroidism In exams, primary hyperparathyroidism is stereotypically seen in elderly females with an unquenchable thirst and an inappropriately normal or raised parathyroid hormone level. It is most commonly due to a solitary adenoma Causes of primary hyperparathyroidism 80%: solitary adenoma 15%: hyperplasia 4%: multiple adenoma 1%: carcinoma Features - 'bones, stones, abdominal groans and psychic moans' Polydipsia, polyuria Peptic ulceration/constipation/pancreatitis Bone pain/fracture Renal stones Depression Hypertension Associations Hypertension Multiple endocrine neoplasia: MEN I and II Investigations Raised calcium, low phosphate PTH may be raised or normal Technetium-MIBI subtraction scan Treatment Parathyroidectomy, if imaging suggests target gland then a focused approach may be used

Answer 364

The brachialis muscle inserts into the ulna. The other muscles are all inserted onto the radius. Radius The radius is one of the two long forearm bones that extends from the lateral side of the elbow to the thumb side of the wrist. It has two expanded ends, of which the distal end is the larger. Key points relating to its topography and relations are outlined below; Upper end Articular cartilage- covers medial > lateral side Articulates with radial notch of the ulna by the annular ligament Muscle attachment- biceps brachii at the tuberosity Shaft Muscle attachment Upper third of the body Supinator Flexor digitorum superficialis Flexor pollicis longus Middle third of the body Pronator teres Lower quarter of the body Pronator quadratus Tendon of supinator longus Lower end Quadrilateral Anterior surface- capsule of wrist joint Medial surface- head of ulna Lateral surface- ends in the styloid process Posterior surface: 3 grooves containing: 1. Tendons of extensor carpi radialis longus and brevis 2. Tendon of extensor pollicis longus 3. Tendon of extensor indicis

Answer 365

p24 antigen test HIV testing HIV seroconversion is symptomatic in 60-80% of patients and typically presents as a glandular fever type illness. Increased symptomatic severity is associated with poorer long term prognosis. It typically occurs 3-12 weeks after infection Features sore throat lymphadenopathy malaise, myalgia, arthralgia diarrhoea maculopapular rash mouth ulcers rarely meningoencephalitis Diagnosis antibodies to HIV may not be present HIV PCR and p24 antigen tests can confirm diagnosis HIV antibody test most common and accurate test usually consists of both a screening ELISA (Enzyme Linked Immuno-Sorbent Assay) test and a confirmatory Western Blot Assay most people develop antibodies to HIV at 4-6 weeks but 99% do by 3 months p24 antigen test usually positive from about 1 week to 3 - 4 weeks after infection with HIV sometimes used as an additional screening test in blood banks

Answer 366

Death of CNS tissue through vascular compromise tends to result in colliquative necrosis as the cells have less formal supporting stroma. Cell death Cells can die via two mechanisms; necrosis and apoptosis. These are outlined below: Necrosis Necrosis is characterised by bioenergetics failure. Loss of tissue perfusion results in hypoxia and an inability to generate ATP. The integrity of the cellular membrane is lost and the loss of ATP results in loss of energy dependent cellular transport mechanisms. There is an influx of water, ionic instability and cellular lysis. The release of intracellular contents may stimulate an inflammatory response. Several types of necrosis are recognised; coagulative, colliquative, caseous, gangrene, fibrinoid and fat necrosis. The type of tissue and the underlying cause determine the predominant necrosis pattern. Coagulative necrosis The commonest type, occurs in most organs Tissue is initially firm, later becomes soft as tissue is digested by macrophages In the early phases the histological appearances may demonstrate little change In later stages cellular outlines are seen with loss of intracellular detail Colliquative necrosis Occurs in tissues with no supporting stroma Dominant necrosis pattern in the CNS Necrotic site may eventually become encysted Caseous necrosis No definable structure seen in the necrotic tissue Amorphous eosinophilic tissue may be seen histologically Classically seen in tuberculosis Gangrene Necrosis with putrefaction of tissue May complicate ischaemia Haemoglobin degenerates and results in the deposition of iron sulphide (which is why the tissue is black) Both wet and dry gangrene may occur, in wet gangrene there is often a liquefactive component and super-added infection (which usually smells!) Fibrinoid necrosis Classically seen in arterioles in patients with hypertension (malignant type) Necrosis of the smooth muscle wall occurs and plasma may extravasate into the media with fibrin deposition Fat necrosis Direct trauma to fat can result in rupture of adipocytes Lipids incite a local inflammatory reaction Inflammatory cells phagocytose the lipid with eventual fibrosis Apoptosis Also known as programmed cell death Energy dependent pathways are activated via a number of intracellular signalling mechanisms It is the result of the activation of caspases triggered by the bcl-2 family or the binding of the FAS ligand to its receptor DNA fragments, mitochondrial function ceases, nuclear and cellular shrinkage occurs Phagocytosis of the cell does not occur, instead the cell degenerates into apoptotic bodies

Answer 367

It drains to the internal jugular vein. Which is one of the reasons why it bleeds so copiously if a ligature slips. Thyroid gland Right and left lobes connected by isthmus Surrounded by sheath from pretracheal layer of deep fascia Apex: Lamina of thyroid cartilage Base: 4th-5th tracheal ring Pyramidal lobe: from isthmus May be attached to foramen caecum at the base of the tongue Relations Anteromedially Sternothyroid Superior belly of omohyoid Sternohyoid Anterior aspect of sternocleidomastoid Posterolaterally Carotid sheath Medially Larynx Trachea Pharynx Oesophagus Cricothyroid muscle External laryngeal nerve (near superior thyroid artery) Recurrent laryngeal nerve (near inferior thyroid artery) Posterior Parathyroid glands Anastomosis of superior and inferior thyroid arteries Isthmus Anteriorly: Sternothyroids, sternohyoids, anterior jugular veins Posteriorly: 2nd, 3rd, 4th tracheal rings (attached via Ligament of Berry) Blood Supply Arterial Superior thyroid artery (1st branch of external carotid) Inferior thyroid artery (from thyrocervical trunk) Thyroidea ima (in 10% of population -from brachiocephalic artery or aorta) Venous Superior and middle thyroid veins - into the IJV Inferior thyroid vein - into the brachiocephalic veins

Answer 368

Head injury and haematoma Risk of haematoma (requiring removal) in adults attending accident and emergency units following head injury. Injury Conscious level Risk of haematoma requiring removal Concussion, no skull fracture Orientated 1 in 6000 Concussion, no skull fracture Not orientated 1 in 120 Skull fracture Orientated 1 in 32 Skull fracture Not orientated 1 in 4

Answer 369

MEN IIa Medullary thyroid cancer Hyperparathyroidism (usually hyperplasia) Phaeochromocytoma In MEN IIa the commonest lesion is medullary thyroid cancer, with regards to the parathyroid glands the most common lesion is hyperplasia. In MEN I a parathyroid adenoma is the most common lesion. Multiple Endocrine Neoplasia Multiple endocrine neoplasia (MEN) is inherited as an autosomal dominant disorder. The table below summarises the three main types of MEN: MEN type I MEN type IIa MEN type IIb Mnemonic 'three P's': Parathyroid (95%): Parathyroid adenoma Pituitary (70%): Prolactinoma/ACTH/Growth Hormone secreting adenoma Pancreas (50%): Islet cell tumours/Zollinger Ellison syndrome also: Adrenal (adenoma) and thyroid (adenoma) Phaeochromocytoma Medullary thyroid cancer (70%) Hyperparathyroidism (60%) Same as MEN IIa with addition of: Marfanoid body habitus Mucosal neuromas MENIN gene (chromosome 11) Most common presentation = hypercalcaemia RET oncogene (chromosome 10) RET oncogene (chromosome 10)

Answer 370

Superior Thyroid Artery Mnemonic (Order in which they branch off)Some (sup thyroid)Attendings (Ascending Pharyngeal)Like (Lingual)Freaking (Facial)Out (Occipital)Potential (Post auricular)Medical (Maxillary)Students (Sup temporal) The first branch of the external carotid artery is the superior thyroid artery. The inferior thyroid artery is derived from the thyrocervical trunk. External carotid artery The external carotid commences immediately lateral to the pharyngeal side wall. It ascends and lies anterior to the internal carotid and posterior to the posterior belly of digastric and stylohyoid. More inferiorly it is covered by sternocleidomastoid, passed by hypoglossal nerves, lingual and facial veins. It then pierces the fascia of the parotid gland finally dividing into its terminal branches within the gland itself. Surface marking of the carotid This is an imaginary line drawn from the bifurcation of the common carotid passing behind the angle of the jaw to a point immediately anterior to the tragus of the ear. Branches of the external carotid artery It has six main branches, three in front, two behind and one deep. Three in front Superior thyroid Lingual Facial Two behind Occipital Posterior auricular Deep Ascending pharyngeal

Answer 371

Discomfort of the hand is not uncommon in Dupuytren's contracture, true pain is unusual. The disease most commonly affects the ring and little fingers. Hand diseases Dupuytrens contracture Fixed flexion contracture of the hand where the fingers bend towards the palm and cannot be fully extended. Caused by underlying contractures of the palmar aponeurosis . The ring finger and little finger are the fingers most commonly affected. The middle finger may be affected in advanced cases, but the index finger and the thumb are nearly always spared. Progresses slowly and is usually painless. In patients with this condition, the tissues under the skin on the palm of the hand thicken and shorten so that the tendons connected to the fingers cannot move freely. The palmar aponeurosis becomes hyperplastic and undergoes contracture. Commonest in males over 40 years of age. Association with liver cirrhosis and alcoholism. However, many cases are idiopathic. Treatment is surgical and involves fasciectomy. However, the condition may recur and many surgical therapies are associated with risk of neurovascular damage to the digital nerves and arteries. Carpal tunnel syndrome Idiopathic median neuropathy at the carpal tunnel. Characterised by altered sensation of the lateral 3 fingers. The condition is commoner in females and is associated with other connective tissue disorders such as rheumatoid disease. It may also occur following trauma to the distal radius. Symptoms occur mainly at night in early stages of the condition. Examination may demonstrate wasting of the muscles of the thenar eminence and symptoms may be reproduced by Tinels test (compression of the contents of the carpal tunnel). Formal diagnosis is usually made by electrophysiological studies. Treatment is by surgical decompression of the carpal tunnel, a procedure achieved by division of the flexor retinaculum. Non - surgical options include splinting and bracing. Miscellaneous hand lumps Osler's nodes Osler's nodes are painful, red, raised lesions found on the hands and feet. They are the result of the deposition of immune complexes. Bouchard's nodes Hard, bony outgrowths or gelatinous cysts on the proximal interphalangeal joints (the middle joints of fingers or toes.) They are a sign of osteoarthritis, and are caused by formation of calcific spurs of the articular cartilage. Heberden's nodes Typically develop in middle age, beginning either with a chronic swelling of the affected joints or the sudden painful onset of redness, numbness, and loss of manual dexterity. This initial inflammation and pain eventually subsides, and the patient is left with a permanent bony outgrowth that often skews the fingertip sideways. It typically affects the DIP joint. Ganglion Swelling in association with a tendon sheath commonly near a joint. They are common lesions in the wrist and hand. Usually they are asymptomatic and cause little in the way of functional compromise. They are fluid filled although the fluid is similar to synovial fluid it is slightly more viscous. When the cysts are troublesome they may be excised.

Answer 372

ADH (vasopressin) results in the insertion of aquaporin channels in apical membrane of the distal tubule and collecting ducts. Renal Physiology Overview Each nephron is supplied with blood from an afferent arteriole that opens onto the glomerular capillary bed. Blood then flows to an efferent arteriole, supplying the peritubular capillaries and medullary vasa recta. The kidney receives up to 25% of resting cardiac output. Control of blood flow The kidney is able to autoregulate its blood flow between systolic pressures of 80- 180mmHg so there is little variation in renal blood flow. This is achieved by myogenic control of arteriolar tone, both sympathetic input and hormonal signals (e.g. renin) are responsible. Glomerular structure and function Blood inside the glomerulus has considerable hydrostatic pressure. The basement membrane has pores that will allow free diffusion of smaller solutes, larger negatively charged molecules such as albumin are unable to cross. The glomerular filtration rate (GFR) is equal to the concentration of a solute in the urine, times the volume of urine produced per minute, divided by the plasma concentration (assuming that the solute is freely diffused e.g. inulin). In clinical practice creatinine is used because it is subjected to very little proximal tubular secretion. Although subject to variability, the typical GFR is 125ml per minute. Glomerular filtration rate = Total volume of plasma per unit time leaving the capillaries and entering the bowman's capsule Renal clearance = volume plasma from which a substance is removed per minute by the kidneys Substances used to measure GFR have the following features: 1. Inert 2. Free filtration from the plasma at the glomerulus (not protein bound) 3. Not absorbed or secreted at the tubules 4. Plasma concentration constant during urine collection Examples: inulin, creatinine GFR = urine concentration (mmol/l) x urine volume (ml/min) -------------------------------------------------------------------------- plasma concentration (mmol/l) The clearance of a substance is dependent not only on its diffusivity across the basement membrane but also subsequent tubular secretion and / or reabsorption. So glucose which is freely filtered across the basement membrane is usually reabsorbed from tubules giving a clearance of zero. Tubular function Reabsorption and secretion of substances occurs in the tubules. In the proximal tubule substrates such as glucose, amino acids and phosphate are co-transported with sodium across the semi permeable membrane. Glucose is reabsorbed by both active and passive processes. The former uses sodium–glucose co-transporters (SGLTs) in the proximal convoluted tubule. The latter achieved through facilitated and passive process through GLUT transporters. Up to two thirds of filtered water is reabsorbed in the proximal tubules. This will lead to increase in urea concentration in the distal tubule allowing for its increased diffusion. Substances to be secreted into the tubules are taken up from the peritubular blood by tubular cells. Solutes such as paraaminohippuric acid are cleared with a single passage through the kidneys and this is why it is used to measure renal plasma flow. Ions such as calcium and phosphate will have a tubular reabsorption that is influenced by plasma PTH levels. Potassium may be both secreted and re-absorbed and is co-exchanged with sodium. Loop of Henle Approximately 60 litres of water containing 9000mmol sodium enters the descending limb of the loop of Henle in 24 hours. Loops from the juxtamedullary nephrons run deep into the medulla. The osmolarity of fluid changes and is greatest at the tip of the papilla. The thick ascending limb is impermeable to water, but highly permeable to sodium and chloride ions. This loss means that at the beginning of the thick ascending limb the fluid is hypo osmotic compared with adjacent interstitial fluid. In the thick ascending limb the reabsorption of sodium and chloride ions occurs by both facilitated and passive diffusion pathways. The loops of Henle are co-located with vasa recta, these will have similar solute compositions to the surrounding extracellular fluid so preventing the diffusion and subsequent removal of this hypertonic fluid. The energy dependent reabsorption of sodium and chloride in the thick ascending limb helps to maintain this osmotic gradient.

Answer 373

Features of an addisonian crisis: Hyponatraemia Hyperkalaemia Hypoglycaemia This man is on steroids for polymyalgia rheumatica. Surgery can precipitate acute adrenal deficiency. The diagnosis is further confirmed by the blood results of hyponatraemia, hyperkalaemia and hypoglycaemia. This patient urgently needs hydrocortisone. Addisonian crisis Causes Sepsis or surgery causing an acute exacerbation of chronic insufficiency (Addison's, Hypopituitarism) Adrenal haemorrhage eg Waterhouse-Friderichsen syndrome (fulminant meningococcemia) Steroid withdrawal Management Hydrocortisone 100 mg im or iv 1 litre normal saline infused over 30-60 mins or with dextrose if hypoglycaemic Continue hydrocortisone 6 hourly until the patient is stable. No fludrocortisone is required because high cortisol exerts weak mineralocorticoid action Oral replacement may begin after 24 hours and be reduced to maintenance over 3-4 days

Answer 374

Lupus vulgaris is not associated with the Koebner phenomenon. Koebner phenomenon The Koebner phenomenon describes skin lesions which appear at the site of injury. It is seen in: Psoriasis Vitiligo Warts Lichen planus Lichen sclerosus Molluscum contagiosum

Answer 375

The posterior cerebral arteries are formed at the bifurcation of the basilar artery and is connected to the circle of Willis via the posterior communicating artery. The posterior cerebral arteries supply the occipital lobe and part of the temporal lobe. Circle of Willis The two internal carotid arteries and two vertebral arteries form an anastomosis known as the Circle of Willis on the inferior surface of the brain. Each half of the circle is formed by: 1. Anterior communicating artery 2. Anterior cerebral artery 3. Internal carotid artery 4. Posterior communicating artery 5. Posterior cerebral arteries and the termination of the basilar artery The circle and its branches supply; the corpus striatum, internal capsule, diencephalon and midbrain. Vertebral arteries Enter the cranial cavity via foramen magnum Lie in the subarachnoid space Ascend on anterior surface of medulla oblongata Unite to form the basilar artery at the base of the pons Branches: Posterior spinal artery Anterior spinal artery Posterior inferior cerebellar artery Basilar artery Branches: Anterior inferior cerebellar artery Labyrinthine artery Pontine arteries Superior cerebellar artery Posterior cerebral artery (at the point where it bifurcates) Internal carotid arteries Branches: Posterior communicating artery Anterior cerebral artery Middle cerebral artery Anterior choroid artery

Answer 376

The presence of metastatic disease in the context of pancreatic cancer renders this incurable and resection of metastatic disease is not appropriate. Pancreatic cancer - Adenocarcinoma Risk factors: Smoking, diabetes, adenoma, familial adenomatous polyposis Mainly occur in the head of the pancreas (70%) Spread locally and metastasizes to the liver Carcinoma of the pancreas should be differentiated from other periampullary tumours with better prognosis Clinical features Weight loss Painless jaundice Epigastric discomfort (pain usually due to invasion of the coeliac plexus is a late feature) Pancreatitis Trousseau's sign: migratory superficial thrombophlebitis Investigations USS: May miss small lesions CT Scanning (pancreatic protocol). If unresectable on CT then no further staging needed PET/CT for those with operable disease on CT alone ERCP/ MRI for bile duct assessment Staging laparoscopy to exclude peritoneal disease Management Head of pancreas: Whipple's resection (SE dumping and ulcers). Newer techniques include pylorus preservation and SMA/ SMV resection Carcinoma body and tail: poor prognosis, distal pancreatectomy, if operable Usually adjuvent chemotherapy for resectable disease ERCP and stent for jaundice and palliation Surgical bypass may be needed for duodenal obstruction

Answer 377

Mnemonic for radial nerve muscles: BEST B rachioradialis E xtensors S upinator T riceps Radial nerve Continuation of posterior cord of the brachial plexus (root values C5 to T1) Path In the axilla: lies posterior to the axillary artery on subscapularis, latissimus dorsi and teres major. Enters the arm between the brachial artery and the long head of triceps (medial to humerus). Spirals around the posterior surface of the humerus in the groove for the radial nerve. At the distal third of the lateral border of the humerus it then pierces the intermuscular septum and descends in front of the lateral epicondyle. At the lateral epicondyle it lies deeply between brachialis and brachioradialis where it then divides into a superficial and deep terminal branch. Deep branch crosses the supinator to become the posterior interosseous nerve.

Answer 378

Mnemonic for muscle attachment on greater trochanter is POGO: Piriformis Obturator internus Gemelli Obturator externus The quadratus femoris fibres pass laterally to be inserted into the quadrate tubercle on the intertrochanteric crest of the femur. The other muscles all insert on the trochanteric fossa lying medial to the greater trochanter. Gluteal region Gluteal muscles Gluteus maximus: inserts to gluteal tuberosity of the femur and iliotibial tract Gluteus medius: attach to lateral greater trochanter Gluteus minimis: attach to anterior greater trochanter All extend and abduct the hip Deep lateral hip rotators Piriformis Gemelli Obturator internus Quadratus femoris Nerves Superior gluteal nerve (L4,L5, S1) Gluteus medius Gluteus minimis Tensor fascia lata Inferior gluteal nerve (L5, S1, S2) Gluteus maximus Damage to the superior gluteal nerve will result in the patient developing a Trendelenberg gait. Affected patients are unable to abduct the thigh at the hip joint. During the stance phase, the weakened abductor muscles allow the pelvis to tilt down on the opposite side. To compensate, the trunk lurches to the weakened side to attempt to maintain a level pelvis throughout the gait cycle. The pelvis sags on the opposite side of the lesioned superior gluteal nerve.

Answer 379

To remember nerve roots and their reflexes: 1-2 Ankle (S1-S2) 3-4 Knee (L3-L4) 5-6 Biceps (C5-C6) 7-8 Triceps (C7-C8) The radial nerve innervates all three heads of triceps, with a separate branch to each head. Triceps Origin Long head- infraglenoid tubercle of the scapula. Lateral head- dorsal surface of the humerus, lateral and proximal to the groove of the radial nerve Medial head- posterior surface of the humerus on the inferomedial side of the radial groove and both of the intermuscular septae Insertion Olecranon process of the ulna. Here the olecranon bursa is between the triceps tendon and olecranon. Some fibres insert to the deep fascia of the forearm, posterior capsule of the elbow (preventing the capsule from being trapped between olecranon and olecranon fossa during extension) Innervation Radial nerve Blood supply Profunda brachii artery Action Elbow extension. The long head can adduct the humerus and extend it from a flexed position Relations The radial nerve and profunda brachii vessels lie between the lateral and medial heads

Answer 380

Groshong lines and Hickman lines are similar and knowledge of these systems is needed because surgeons are often called upon to either insert or remove them. Chemotherapy for AML requires long term therapy and multiple blood tests therefore an indwelling device is preferable. Intravenous access Venous access A number of routes for establishing venous access are available. Peripheral venous cannula Easy to insert with minimal morbidity. Wide lumen cannulae can provide rapid fluid infusions. When properly managed infections may be promptly identified and the cannula easily re sited. Problems relate to their peripheral sites and they are unsuitable for the administration of vaso active drugs, such as inotropes and irritant drugs such as TPN (except in the very short term setting). Central lines Insertion is more difficult and most operators and NICE advocate the use of ultra sound. Coagulopathies may lead to haemorrhage following iatrogenic arterial injury. Femoral lines are easier to insert and iatrogenic injuries easier to manage in this site however they are prone to high infection rates. Internal jugular route is preferred. They have multiple lumens allowing for administration of multiple infusions. The lumens are relatively narrow and thus they do not allow particularly rapid rates of infusion. Intraosseous access This is typically undertaken at the anteromedial aspect of the proximal tibia and provides access to the marrow cavity and circulatory system. Although traditionally preferred in paediatric practice they may be used in adults and a wide range of fluids can be infused using these devices. Tunneled lines Tunneled lines such as Groshong and Hickman lines are popular devices for patients with long term therapeutic requirements. These devices are usually inserted using ultrasound guidance into the internal jugular vein and then tunneled under the skin. A cuff of woven material is sited near the end and helps to anchor the device into the tissues. These cuffs require formal dissection to allow the device to be removed. Tunneled lines can be linked to injection ports that are located under the skin. These are especially popular in paediatric practice. Peripherally inserted central cannula Referred to as PICC lines, these are popular methods for establishing central venous access. Because they are inserted peripherally they are less prone to major complications relating to device insertion than conventional central lines.

Answer 381

The canal exists to allow for the physiological expansion of the femoral vein, which lies lateral to it. Femoral canal The femoral canal lies at the medial aspect of the femoral sheath. The femoral sheath is a fascial tunnel containing both the femoral artery laterally and femoral vein medially. The canal lies medial to the vein. Borders of the femoral canal Laterally Femoral vein Medially Lacunar ligament Anteriorly Inguinal ligament Posteriorly Pectineal ligament Contents Lymphatic vessels Cloquet's lymph node Physiological significance Allows the femoral vein to expand to allow for increased venous return from the lower limbs. Pathological significance As a potential space, it is the site of femoral hernias. The relatively tight neck places these at high risk of strangulation.

Answer 382

The extensor hallucis longus tendon lies medial to the dorsalis pedis artery. Foot- anatomy Arches of the foot The foot is conventionally considered to have two arches. The longitudinal arch is higher on the medial than on the lateral side. The posterior part of the calcaneum forms a posterior pillar to support the arch. The lateral part of this structure passes via the cuboid bone and the lateral two metatarsal bones. The medial part of this structure is more important. The head of the talus marks the summit of this arch, located between the sustentaculum tali and the navicular bone. The anterior pillar of the medial arch is composed of the navicular bone, the three cuneiforms and the medial three metatarsal bones. The transverse arch is situated on the anterior part of the tarsus and the posterior part of the metatarsus. The cuneiforms and metatarsal bases narrow inferiorly, which contributes to the shape of the arch. Intertarsal joints Sub talar joint Formed by the cylindrical facet on the lower surface of the body of the talus and the posterior facet on the upper surface of the calcaneus. The facet on the talus is concave anteroposteriorly, the other is convex. The synovial cavity of this joint does not communicate with any other joint. Talocalcaneonavicular joint The anterior part of the socket is formed by the concave articular surface of the navicular bone, posteriorly by the upper surface of the sustentaculum tali. The talus sits within this socket Calcaneocuboid joint Highest point in the lateral part of the longitudinal arch. The lower aspect of this joint is reinforced by the long plantar and plantar calcaneocuboid ligaments. Transverse tarsal joint The talocalcaneonavicular joint and the calcaneocuboid joint extend across the tarsus in an irregular transverse plane, between the talus and calcaneus behind and the navicular and cuboid bones in front. This plane is termed the transverse tarsal joint. Cuneonavicular joint Formed between the convex anterior surface of the navicular bone and the concave surface of the the posterior ends of the three cuneiforms. Intercuneiform joints Between the three cuneiform bones. Cuneocuboid joint Between the circular facets on the lateral cuneiform bone and the cuboid. This joint contributes to the tarsal part of the transverse arch. A detailed knowledge of the joints is not required for MRCS Part A. However, the contribution they play to the overall structure of the foot should be appreciated Nerves in the foot Lateral plantar nerve Passes anterolaterally towards the base of the 5th metatarsal between flexor digitorum brevis and flexor accessorius. On the medial aspect of the lateral plantar artery. At the base of the 5th metatarsal it splits into superficial and deep branches. Medial plantar nerve Passes forwards with the medial plantar artery under the cover of the flexor retinaculum to the interval between abductor hallucis and flexor digitorum brevis on the sole of the foot. Plantar arteries Arise under the cover of the flexor retinaculum, midway between the tip of the medial malleolus and the most prominent part of the medial side of the heel. Medial plantar artery. Passes forwards medial to medial plantar nerve in the space between abductor hallucis and flexor digitorum brevis.Ends by uniting with a branch of the 1st plantar metatarsal artery. Lateral plantar artery. Runs obliquely across the sole of the foot. It lies lateral to the lateral plantar nerve. At the base of the 5th metatarsal bone it arches medially across the foot on the metatarsals Dorsalis pedis artery This vessel is a direct continuation of the anterior tibial artery. It commences on the front of the ankle joint and runs to the proximal end of the first metatarsal space. Here is gives off the arcuate artery and continues forwards as the first dorsal metatarsal artery. It is accompanied by two veins throughout its length. It is crossed by the extensor hallucis brevis

Answer 383

Although the optic chiasm is closely related to the pituitary, and craniopharyngiomas may compress this structure leading to bitemporal hemianopia, it is separated from the chiasm itself by a dural fold. Pituitary Gland The pituitary gland is located within the sella turcica within the sphenoid bone in the middle cranial fossa. It is covered by a dural fold and weighs around 0.5g. It is attached to the hypothalamus by the infundibulum. The anterior pituitary receives hormonal stimuli from the hypothalamus by way of the hypothalamo-pituitary portal system. It develops from a depression in the wall of the pharynx (Rathkes pouch). Anterior pituitary hormones Growth hormone Thyroid stimulating hormone ACTH Prolactin LH and FSH Melanocyte releasing hormone Posterior pituitary hormones Oxytocin Anti diuretic hormone

Answer 384

The short head of biceps femoris, which may occasionally be absent, is innervated by the common peroneal component of the sciatic nerve. The long head is innervated by the tibial division of the sciatic nerve. Biceps femoris The biceps femoris is one of the hamstring group of muscles located in the posterior upper thigh. It has two heads. Long head Origin Ischial tuberosity Insertion Fibular head Action Knee flexion, lateral rotation tibia, extension hip Innervation Tibial division of sciatic nerve (L5, S1, S2) Arterial supply Profunda femoris artery, inferior gluteal artery, and the superior muscular branches of popliteal artery Short head Origin Lateral lip of linea aspera, lateral supracondylar ridge of femur Insertion Fibular head Action Knee flexion, lateral rotation tibia Innervation Common peroneal division of sciatic nerve (L5, S1, S2) Arterial supply Profunda femoris artery, inferior gluteal art

Answer 385

The key point is that the phrenic nerve runs posterior to the medial aspect of the first rib. Superiorly, it lies on the surface of scalenus anterior. Phrenic nerve Origin C3,4,5 Supplies Diaphragm, sensation central diaphragm and pericardium Path The phrenic nerve passes with the internal jugular vein across scalenus anterior. It passes superficial to prevertebral fascia of deep cervical fascia. Left: crosses anterior to the 1st part of the subclavian artery. Right: Anterior to scalenus anterior and crosses anterior to the 2nd part of the subclavian artery. On both sides, the phrenic nerve runs posterior to the subclavian vein and posterior to the internal thoracic artery as it enters the thorax. Right phrenic nerve In the superior mediastinum: anterior to right vagus and laterally to superior vena cava Middle mediastinum: right of pericardium It passes over the right atrium to exit the diaphragm at T8 Left phrenic nerve Passes lateral to the left subclavian artery, aortic arch and left ventricle Passes anterior to the root of the lung Pierces the diaphragm alone

Answer 386

Posterior circumflex humeral The other branches include: Subscapular Anterior circumflex humeral The dorsal scapular artery arises from the third part of the subclavian artery in most cases Axilla Boundaries of the axilla Medially Chest wall and Serratus anterior Laterally Humeral head Floor Subscapularis Anterior aspect Lateral border of Pectoralis major Fascia Clavipectoral fascia Content: Long thoracic nerve (of Bell) Derived from C5-C7 and passes behind the brachial plexus to enter the axilla. It lies on the medial chest wall and supplies serratus anterior. Its location puts it at risk during axillary surgery and damage will lead to winging of the scapula. Thoracodorsal nerve and thoracodorsal trunk Innervate and vascularise latissimus dorsi. Axillary vein Lies at the apex of the axilla, it is the continuation of the basilic vein. Becomes the subclavian vein at the outer border of the first rib. Intercostobrachial nerves Traverse the axillary lymph nodes and are often divided during axillary surgery. They provide cutaneous sensation to the axillary skin. Lymph nodes The axilla is the main site of lymphatic drainage for the breast. Branches of Axillary Artery FROM FIRST PART Superior thoracic artery, a very small branch, originates near the subclavius, enters between the pectoralis major and minor muscles, and then these muscles go towards the medial wall of the axilla. FROM SECOND PART Thoraco-acromial artery (acromiothoracic artery) : emerges at the upper border of pectoralis minor, pierces clavipectoral fascia and soon breaks up into 4 branches: (a) pectoral branch, (b) deltoid branch, (c) acromial branch, and (d) clavicular branch. These branches radiate at right angle to every other. The pectoral branch consists of pectoral muscles, deltoid branch, ends by joining anastomosis over the acromion, clavicular branch supplied sternoclavicular joint. Lateral thoracic artery : emerges at and runs along the inferior border of pectoralis minor, supplying the branches to pectoralis major and minor and serratus anterior muscles. In the females, the lateral thoracic artery is large and gives significant supply to the breast via it’s lateral mammary branches. FROM THIRD PART Subscapular artery, the largest branch of axillary artery, runs along the lower border of the subscapularis and ends near the inferior angle of the scapula. It supplies a large branch, the circumflex scapular artery; which goes through upper triangular intermuscular space, winds round the lateral border of scapula to goes into infraspinous fossa. Additionally, it supplies numerous small branches. Anterior circumflex humeral artery, a small branch, enters in front of surgical neck of humerus and anastomoses with the posterior circumflex humeral artery to create an arterial circle around the surgical neck of humerus. It supplies an ascending branch, which runs upwards into the intertubercular sulcus of humerus to supply the head of humerus and shoulder joint. Posterior circumflex humeral artery, larger in relation to the anterior circumflex humeral artery, enters backwards, together with axillary nerve via the quadrangular intermuscular space, crosses the posterior aspect of surgical neck of humerus to anastomose with the anterior circumflex humeral artery. It supplies the deltoid muscle and shoulder joint.

Answer 387

Normotension is seen in around 10% cases. The remainder show a degree of hypertension. Phaeochromocytoma and adrenal lesions Phaeochromocytoma Neuroendocrine tumour of the chromaffin cells of the adrenal medulla. Hypertension and hyperglycaemia are often found. 10% of cases are bilateral. 10% occur in children. 11% are malignant (higher when tumour is located outside the adrenal). 10% will not be hypertensive. Familial cases are usually linked to the Multiple endocrine neoplasia syndromes (considered under its own heading). Most tumours are unilateral (often right sided) and smaller than 10cm. Diagnosis Urine and plasma metanephrine levels. CT and MRI scanning are both used to localise the lesion. Treatment Patients require medical therapy first. An irreversible alpha adrenoreceptor blocker should be given, although minority may prefer reversible blockade(1). Labetolol may be co-administered for cardiac chronotropic control. Isolated beta blockade should not be considered as it will lead to unopposed alpha activity. These patients are often volume depleted and will often require moderate volumes of intra venous normal saline perioperatively. Once medically optimised the phaeochromocytoma should be removed. Most adrenalectomies can now be performed using a laparoscopic approach(2). The adrenals are highly vascular structures and removal can be complicated by catastrophic haemorrhage in the hands of the inexperienced. This is particularly true of right sided resections where the IVC is perilously close. Should the IVC be damaged a laparotomy will be necessary and the defect enclosed within a Satinsky style vascular clamp and the defect closed with prolene sutures. Attempting to interfere with the IVC using any instruments other than vascular clamps will result in vessel trauma and make a bad situation much worse. Incidental adrenal lesions Adrenal lesions may be identified on CT scanning performed for other reasons(3). Factors suggesting benign disease on CT include(4): Size less than 3cm Homogeneous texture Lipid rich tissue Thin wall to lesion All patients with incidental lesions should be managed jointly with an endocrinologist and full work up as described above. Patients with functioning lesions or those with adverse radiological features (Particularly size >3cm) should proceed to surgery.

Answer 388

They are true aneurysms and have all 3 layers of arterial wall. Abdominal aorta aneurysm - Abdominal aortic aneurysms are a common problem in vascular surgery. They may occur as either true or false aneurysm. With the former all 3 layers of the arterial wall are involved, in the latter only a single layer of fibrous tissue forms the aneurysm wall. True abdominal aortic aneurysms have an approximate incidence of 0.06 per 1000 people. They are commonest in elderly men and for this reason the UK is now introducing the aneurysm screening program with the aim of performing an abdominal aortic ultrasound measurement in all men aged 65 years. Causes Several different groups of patients suffer from aneurysmal disease. The commonest group is those who suffer from standard arterial disease, i.e. Those who are hypertensive and have been or are smokers. Other patients such as those suffering from connective tissue diseases such as Marfan's may also develop aneurysms. In patients with abdominal aortic aneurysms the extracellular matrix becomes disrupted with a change in the balance of collagen and elastic fibres. Management Most abdominal aortic aneurysms are an incidental finding. Symptoms most often relate to rupture or impending rupture. 20% rupture anteriorly into the peritoneal cavity. Very poor prognosis. 80% rupture posteriorly into the retroperitoneal space The risk of rupture is related to aneurysm size, only 2% of aneurysms measuring less than 4cm in diameter will rupture over a 5 year period. This contrasts with 75% of aneurysms measuring over 7cm in diameter. This is well explained by Laplaces' law which relates size to transmural pressure. For this reason most vascular surgeons will subject patients with an aneurysm size of 5cm or greater to CT scanning of the chest, abdomen and pelvis with the aim of delineating anatomy and planning treatment. Depending upon co-morbidities, surgery is generally offered once the aneurysm is between 5.5cm and 6cm. Indications for surgery Symptomatic aneurysms (80% annual mortality if untreated) Increasing size above 5.5cm if asymptomatic Rupture (100% mortality without surgery) Surgical procedures Abdominal aortic aneurysm repair Procedure: GA Invasive monitoring (A-line, CVP, catheter) Incision: Midline or transverse Bowel and distal duodenum mobilised to access aorta. Aneurysm neck and base dissected out and prepared for cross clamp Systemic heparinisation Cross clamp (proximal first) Longitudinal aortotomy Atherectomy Deal with back bleeding from lumbar vessels and inferior mesenteric artery Insert graft either tube or bifurcated depending upon anatomy Suture using Prolene (3/0 for proximal , distal anastomosis suture varies according to site) Clamps off: End tidal CO2 will rise owing to effects of reperfusion, at this point major risk of myocardial events. Haemostasis Closure of aneurysm sac to minimise risk of aorto-enteric fistula Closure: Loop 1 PDS or Prolene to abdominal wall Skin- surgeons preference Post operatively: ITU (Almost all) Greatest risk of complications following emergency repair Complications: Embolic- gut and foot infarcts Cardiac - owing to premorbid states, re-perfusion injury and effects of cross clamp Wound problems Later risks related to graft- infection and aorto-enteric fistula Special groups Supra renal AAA These patients will require a supra renal clamp and this carries a far higher risk of complications and risk of renal failure. Ruptured AAA Pre-operatively the management depends upon haemodynamic instability. In patients with symptoms of rupture (typical pain, haemodynamic compromise and risk factors) then ideally prompt laparotomy. In those with vague symptoms and haemodynamic stability the ideal test is CT scan to determine whether rupture has occurred or not. Most common rupture site is retroperitoneal 80%. These patients will tend to develop retroperitoneal haematoma. This can be disrupted if Bp is allowed to rise too high so aim for Bp 100mmHg. Operative details are similar to elective repair although surgery should be swift, blind rushing often makes the situation worse. Plunging vascular clamps blindly into a pool of blood at the aneurysm neck carries the risk of injury the vena cava that these patients do not withstand. Occasionally a supracoeliac clamp is needed to effect temporary control, although leaving this applied for more than 20 minutes tends to carry a dismal outcome. EVAR Increasingly patients are now being offered endovascular aortic aneurysm repair. This is undertaken by surgeons and radiologists working jointly. The morphology of the aneurysm is important and not all are suitable. Here is a typical list of those features favoring a suitable aneurysm: Long neck Straight iliac vessels Healthy groin vessels Clearly few AAA patients possess the above and compromise has to be made. The use of fenestrated grafts can allow supra renal AAA to be treated. Procedure: GA Radiology or theatre Bilateral groin incisions Common femoral artery dissected out Heparinisation Arteriotomy and insertion of guide wire Dilation of arteriotomy Insertion of EVAR Device Once in satisfactory position it is released Arteriotomy closed once check angiogram shows good position and no endoleak Complications: Endoleaks depending upon site are either Type I or 2. These may necessitate re-intervention and all EVAR patients require follow up . Details are not needed for MRCS.

Answer 389

Palmaris brevis - Ulnar nerve Palmar interossei- Ulnar nerve Adductor pollicis - Ulnar nerve Abductor pollicis longus - Posterior interosseous nerve Abductor pollicis brevis - Median nerve The median nerve innervates all the short muscles of the thumb except the adductor and the deep head of the short flexor. Palmaris and the interossei are innervated by the ulnar nerve. Median nerve The median nerve is formed by the union of a lateral and medial root respectively from the lateral (C5,6,7) and medial (C8 and T1) cords of the brachial plexus; the medial root passes anterior to the third part of the axillary artery. The nerve descends lateral to the brachial artery, crosses to its medial side (usually passing anterior to the artery). It passes deep to the bicipital aponeurosis and the median cubital vein at the elbow. It passes between the two heads of the pronator teres muscle, and runs on the deep surface of flexor digitorum superficialis (within its fascial sheath). Near the wrist it becomes superficial between the tendons of flexor digitorum superficialis and flexor carpi radialis, deep to palmaris longus tendon. It passes deep to the flexor retinaculum to enter the palm, but lies anterior to the long flexor tendons within the carpal tunnel. Branches Region Branch Upper arm No branches, although the nerve commonly communicates with the musculocutaneous nerve Forearm Pronator teres Pronator quadratus Flexor carpi radialis Palmaris longus Flexor digitorum superficialis Flexor pollicis longus Flexor digitorum profundus (only the radial half) Distal forearm Palmar cutaneous branch Hand (Motor) Motor supply (LOAF) Lateral 2 lumbricals Opponens pollicis Abductor pollicis brevis Flexor pollicis brevis Hand (Sensory) Over thumb and lateral 2 ½ fingers On the palmar aspect this projects proximally, on the dorsal aspect only the distal regions are innervated with the radial nerve providing the more proximal cutaneous innervation. Patterns of damage Damage at wrist e.g. carpal tunnel syndrome paralysis and wasting of thenar eminence muscles and opponens pollicis (ape hand deformity) sensory loss to palmar aspect of lateral (radial) 2 ½ fingers Damage at elbow, as above plus: unable to pronate forearm weak wrist flexion ulnar deviation of wrist Anterior interosseous nerve (branch of median nerve) leaves just below the elbow results in loss of pronation of forearm and weakness of long flexors of thumb and index finger

Answer 390

The correct answer is Syringomyelia This patient has syringomyelia which selectively affects the spinotholamic tracts. Syringomyelia is a disorder in which a cystic cavity forms within the spinal cord. The commonest variant is the Arnold- Chiari malformation in which the cavity connects with a congenital malformation affecting the cerebellum. Acquired forms of the condition may occur as a result of previous meningitis, surgery or tumours. Many neurological manifestations have been reported, although the classical variety spares the dorsal columns and medial lemniscus and affecting only the spinothalamic tract with loss of pain and temperature sensation. The bilateral distribution of this patients symptoms would therefore favor syringomyelia over SCID or Brown Sequard syndrome. Osteomyelitis would tend to present with back pain and fever in addition to any neurological signs. Epidural haematoma large enough to produce neurological impairment will usually have motor symptoms in addition to any selective sensory loss, and the history is usually shorter.

Answer 391

The correct answer is Osteomyelitis In an IVDU with back pain and pyrexia have a high suspicion for osteomylelitis. The most likely organism is staph aureus and the cervical spine is the most common region affected. TB tends to affect the thoracic spine and in other causes of osteomyelitis the lumbar spine is affected.

Answer 392

The correct answer is Brown-Sequard syndrome Theme from January 2012 exam Brown -Sequard syndrome is caused by hemisection of the spinal cord. It may result from stab injuries or lateral vertebral fractures. It results in ipsilateral paralysis (pyramidal tract) , and also loss of proprioception and fine discrimination (dorsal columns). Pain and temperature sensation are lost on the contra-lateral side. This is because the fibres of the spinothalamic tract have decussated below the level of the cord transection. Spinal disorders Dorsal column lesion Spinothalamic tract lesion Central cord lesion Infarction spinal cord Loss vibration and proprioception Tabes dorsalis, SACD Loss of pain, sensation and temperature Flaccid paralysis of the upper limbs Dorsal column signs (loss of proprioception and fine discrimination) Osteomyelitis Normally progressive Staph aureus in IVDU, normally cervical region affected Fungal infections in immunocompromised Thoracic region affected in TB Cord compression UMN signs Malignancy Haematoma Fracture Brown-sequard syndrome Hemisection of the spinal cord Ipsilateral paralysis Ipsilateral loss of proprioception and fine discrimination Contralateral loss of pain and temperature

Answer 393

Theme from April 2012 The combination of a crush injury, limb swelling and inability to move digits should raise suspicion of a compartment syndrome that will require a fasciotomy. Paralysis is a very late sign. Compartment syndrome This is a particular complication that may occur following fractures (or following ischaemia re-perfusion injury in vascular patients). It is characterised by raised pressure within a closed anatomical space. The raised pressure within the compartment will eventually compromise tissue perfusion resulting in necrosis. The two main fractures carrying this complication include supracondylar fractures and tibial shaft injuries. Symptoms and signs Pain, especially on movement (even passive) Parasthesiae Pallor may be present Arterial pulsation may still be felt as the necrosis occurs as a result of microvascular compromise Paralysis of the muscle group may occur Diagnosis Is made by measurement of intracompartmental pressure measurements. Pressures in excess of 20mmHg are abnormal and >40mmHg is diagnostic. Treatment This is essentially prompt and extensive fasciotomies In the lower limb the deep muscles may be inadequately decompressed by the inexperienced operator when smaller incisions are performed Myoglobinuria may occur following fasciotomy and result in renal failure and for this reason these patients require aggressive IV fluids Where muscle groups are frankly necrotic at fasciotomy they should be debrided and amputation may have to be considered Death of muscle groups may occur within 4-6 hours

Answer 394

Autologous transplant- same individual (genetically identical) Allograft - Genetically different The kidney is highly susceptible to HLA mismatches and hyperacute rejection may occur in patients with IgG anti HLA Class I antibodies. The liver is at far lower risk of rejection of this nature. Although the heart is sensitive to HLA mismatches this is less than the kidney. Cardiac valves and the cornea incite little immunological response. Organ Transplant A number of different organ and tissue transplants are now available. In many cases an allograft is performed, where an organ is transplanted from one individual to another. Allografts will elicit an immune response and this is one of the main reasons for organ rejection. Graft rejection occurs because allografts have allelic differences at genes that code immunohistocompatability complex genes. The main antigens that give rise to rejection are: ABO blood group Human leucocyte antigens (HLA) Minor histocompatability antigens ABO Matching ABO incompatibility will result in early organ rejection (hyperacute) because of pre existing antibodies to other groups. Group O donors can give organs to any type of ABO recipient whereas group AB donor can only donate to AB recipient. HLA System The four most important HLA alleles are: HLA A HLA B HLA C HLA DR An ideal organ match would be one in which all 8 alleles are matched (remember 2 from each parent, four each = 8 alleles). Modern immunosuppressive regimes help to manage the potential rejection due to HLA mismatching. However, the greater the number of mismatches the worse the long term outcome will be. T lymphocytes will recognise antigens bound to HLA molecules and will then become activated. Clonal expansion then occurs with a response directed against that antigen. Types of organ rejection Hyperacute. This occurs immediately through presence of pre formed antibodies (such as ABO incompatibility). Acute. Occurs during the first 6 months and is usually T cell mediated. Usually tissue infiltrates and vascular lesions. Chronic. Occurs after the first 6 months. Vascular changes predominate. Hyperacute Renal transplants at greatest risk and liver transplants at least risk. Although ABO incompatibility and HLA Class I incompatible transplants will all fare worse in long term. Acute All organs may undergo acute rejection. Mononuclear cell infiltrates predominate. All types of transplanted organ are susceptible and it may occur in up to 50% cases. Chronic Again all transplants with HLA mismatch may suffer this fate. Previous acute rejections and other immunosensitising events all increase the risk. Vascular changes are most prominent with myointimal proliferation leading to organ ischaemia. Organ specific changes are also seen such as loss of acinar cells in pancreas transplants and rapidly progressive coronary artery disease in cardiac transplants. Surgical overview-Renal transplantation A brief overview of the steps involved in renal transplantation is given. Patients with end stage renal failure who are dialysis dependent or likely to become so in the immediate future are considered for transplant. Exclusion criteria include; active malignancy, old age (due to limited organ availability). Patients are medically optimised. Donor kidneys, these may be taken from live related donors and close family, members may have less HLA mismatch than members of the general population. Laparoscopic donor nephrectomy further minimises the operative morbidity for the donor. Other organs are typically taken from brain dead or dying patients who have a cardiac arrest and in whom resuscitation is futile. The key event is to minimise the warm ischaemic time in the donor phase. The kidney once removed is usually prepared on the bench in theatre by the transplant surgeon immediately prior to implantation and factors such as accessory renal arteries and vessel length are assessed and managed. For first time recipients the operation is performed under general anaesthesia. A Rutherford-Morison incision is made on the preferred side. This provides excellent extraperitoneal access to the iliac vessels. The external iliac artery and vein are dissected out and following systemic heparinisation are cross clamped. The vein and artery are anastamosed to the iliacs and the clamps removed. The ureter is then implanted into the bladder and a stent is usually placed to maintain patency. The wounds are then closed and the patient recovered from surgery. In the immediate phase a common problem encountered in cadaveric kidneys is acute tubular necrosis and this tends to resolve. Graft survival times from cadaveric donors are typically of the order of 9 years and monozygotic twin transplant (live donor) may survive as long as 25 years.

Answer 395

Menisci have no nerve or blood supply and thus heal poorly. Established tears with associated symptoms are best managed by arthroscopic menisectomy.

Answer 396

Vital capacity The maximum voluntary ventilation is the maximal ventilation over the course of 1 minute.

Answer 397

This F1 should have spoken to his senior. This patient has familial hypocalciuric hypercalcaemia, which requires no further action. A calcium to creatinine clearance ratio of <0.01 will confirm this diagnosis.

Answer 398

A weeping, crusty lesion such as this is most likely to represent Pagets disease of the nipple (especially since the areolar region is spared). Although no mass lesion is palpable, a proportion of patients will still have an underlying invasive malignancy (hence the lymphadenopathy). Pagets disease differs from eczema of the nipple in that it involves the nipple primarily and only latterly spreads to the areolar (the opposite occurs in eczema).

Answer 399

Quadratus lumborum Origin: Medial aspect of iliac crest and iliolumbar ligament Insertion: 12th rib Action: Pulls the rib cage inferiorly. Lateral flexion. Nerve supply: Anterior primary rami of T12 and L1-3 The rectus abdominis causes flexion of the thoracic spine and therefore the statement suggesting that quaratus lumborum does so is incorrect.

Answer 400

Transfemoral embolectomy without prophylactic fasciotomy A limb which is acutely ischaemic and with normal contralateral pulses normally indicates an acute embolus. Whilst intra arterial thrombolysis may be an option there is a reasonable argument for immediate surgery. A fasciotomy is unlikely to be required.

Answer 401

The correct answer is Angiogram The history favors a more chronic process and the great toe cyanotic spell may be indicative of previous embolism from pathology such as an aneurysm. In the ideal scenario a duplex scan would be performed. However, an angiogram would probably supply sufficient information and allow appropriate endovascular therapy.

Answer 402

Primary amputation This is an unsalvagable limb and is best amputated primarily.

Answer 403

Increased FRC: Erect position Emphysema Asthma Decreased FRC: Pulmonary fibrosis Laparoscopic surgery Obesity Abdominal swelling Muscle relaxants When the patient is upright the diaphragm and abdominal organs put less pressure on the lung bases, allowing for an increase in the functional residual capacity (FRC). Other causes of increased FRC include: Emphysema Asthma In addition to those listed above, causes of reduced FRC include: Abdominal swelling Pulmonary oedema Reduced muscle tone of the diaphragm Age

Answer 404

The radial nerve wraps around the humerus and may be injured during a posterior approach. An IM nail may be preferred as it avoids the complex dissection needed for direct bone exposure.

Answer 405

Loss of elastic fibres from the media In established aneurysmal disease there is dilation of all layers of the arterial wall and loss of both elastin and collagen. The primary event is loss of elastic fibres with subsequent degradation of collagen fibres.

Answer 406

P values are related to the significance levels of a statistical test and therefore are in effect measuring the risk of a type 1 error.

Answer 407

The zona fasciculata of the adrenal gland is the primary site responsible for the production of dehydroepiandrosterone (DHEA). This layer of the adrenal cortex synthesizes DHEA, which is an important precursor for sex hormones. On the other hand, the zona glomerulosa is primarily involved in the production of aldosterone, a mineralocorticoid hormone that regulates sodium and potassium balance in the body. So, when it comes to DHEA, think zona fasciculata!

Answer 408

Aschoff-Rokitansky sinuses are the result of hyperplasia and herniation of epithelial cells through the fibromuscular layer of the gallbladder wall. They may be macroscopic or microscopic. Ashoff-Rokitansky sinuses may be identified in cases of chronic cholecystitis and gallstones. Although gallstones may predispose to the development of gallbladder cancer the actual incidence of dysplasia and metaplastic change is rare. In the elective setting described above necrosis would be rare.

Answer 409

Congenital heart disease Cyanotic: TGA most common at birth, Fallot’s most common overall Acyanotic: VSD most common cause It is important to be aware of common congenital cardiac abnormalities. The main differentiating factor is whether the patient is cyanotic or acyanotic. In the neonate, TGA is the most common condition presenting with profound cyanosis. The other options are causes of acyanotic congenital heart disease

Answer 410

Osteopetrosis Osteopetrosis is an autosomal recessive condition. It is commonest in young adults. They may present with symptoms of anaemia or thrombocytopaenia due to decreased marrow space. Radiology reveals a lack of differentiation between the cortex and the medulla described as marble bone. These bones are very dense and brittle.

Answer 411

Osteogenesis imperfecta Osteogenesis imperfecta is caused by defective osteoid formation due to congenital inability to produce adequate intercellular substances like osteoid, collagen and dentine. There is a failure of maturation of collagen in all the connective tissues.Radiology may show translucent bones, multiple fractures, particularly of the long bones, wormian bones (irregular patches of ossification) and a trefoil pelvis.

Answer 412

Rickets Rickets is the childhood form of osteomalacia. It is due to the failure of the osteoid to ossify due to vitamin D deficiency. Symptoms start about the age of one. The child is small for age and there is a history of failure to thrive. Bony deformities include bowing of the femur and tibia, a large head, deformity of the chest wall with thickening of the costochondral junction (rickettary rosary), and a transverse sulcus in the chest caused by the pull of the diaphragm (Harrison’s sulcus). X- Rays show widening and cupping of the epiphysis of the long bones, most readily apparent in the wrist.

Answer 413

They are at high risk of developing leukaemia.

Answer 414

Axillary nerve The Axillary nerve winds around the bone at the neck of the humerus. The axillary nerve is also at risk during shoulder dislocation.

Answer 415

Brachial Trunks C8-T1 The patient has a Klumpke’s paralysis involving brachial trunks C8-T1. Classically there is weakness of the hand intrinsic muscles. Involvement of T1 may cause a Horner’s syndrome. It occurs as a result of traction injuries or during delivery.

Answer 416

Brachial Trunks C5-6 The patient has an Erb’s palsy involving brachial trunks C5-6.

Answer 417

Aortic transection Aortic transections typically occur distal to the ligamentum arteriosum. A temporary haematoma may prevent the immediate death that usually occurs. This is a deceleration injury. A widened mediastinum may be seen on x-ray.

Answer 418

Duodeno-jejunal flexure disruption This is another site of sudden deceleration injury. Given the large amount of free fluid, if it were blood, then a greater degree of haemodynamic instability would be expected.

Answer 419

Haemopericardium This is most likely a cardiac tamponade produced by haemopericardium. As little as 100ml of blood may result in tamponade as the pericardial sac is not distensible. Diagnosis is suggested by muffled heart sounds, paradoxical pulse and jugular vein distension.

Answer 420

70ml Stroke volumes range from 55-100ml.

Answer 421

Parathyroid carcinomas account for up to 5% of tumours. Adenomas are often encapsulated. Lesions that are fibrotic and densely adherent to the gland may be a carcinoma. 85% cases of primary hyperparathyroidism are due to a single adenoma and this is the reason some surgeons favour a focused parathyroidectomy.

Answer 422

Papillary carcinoma is the most common subtype and may cause lymph node metastasis (mass separate from the gland itself) that is rare with follicular tumours. Anaplastic carcinoma would cause more local symptoms and would be rare in this age group.

Answer 423

Vasopressin, also known as antidiuretic hormone (ADH), is a crucial hormone released from the posterior pituitary gland. Let’s explore its effects: Vasoconstriction of the Afferent Glomerular Arteriole: True. Vasopressin acts on the afferent arteriole of the glomerulus in the kidneys, causing vasoconstriction. This constriction reduces blood flow into the glomerulus, helping to regulate glomerular filtration rate (GFR) and maintain blood pressure1. Increased Permeability of Mesangial Cells to Glucose: False. Vasopressin does not directly affect glucose permeability in mesangial cells. Reduced Permeability of the Inner Medullary Portion of the Collecting Duct to Urea: True. Vasopressin increases the permeability of the collecting ducts in the kidney, allowing for greater reabsorption of water. This process concentrates urine and reduces urea loss2. Increased Secretion of Aldosterone from the Macula Densa: False. Aldosterone is primarily regulated by the zona glomerulosa of the adrenal cortex, not vasopressin. Increased Water Permeability of Distal Tubule Cells of the Kidney: True. Vasopressin acts on the distal tubules and collecting ducts to enhance water reabsorption. It promotes the insertion of aquaporin-2 channels in the tubular cells, allowing water to move from the tubules back into the bloodstream1. In summary, vasopressin primarily affects water balance by regulating water reabsorption in the kidneys, leading to concentrated urine and maintaining blood pressure. The most likely effect of vasopressin (antidiuretic hormone) is increased water permeability of the distal tubule cells of the kidney. Vasopressin acts on the distal tubules and collecting ducts, promoting the insertion of aquaporin-2 channels in the tubular cells. This allows water to move from the tubules back into the bloodstream, leading to water reabsorption and concentrated urine

Answer 424

Aldosterone is responsible for regulating ion exchange in salivary glands. It acts on a sodium / potassium ion exchange pump.It is a mineralocorticoid hormone derived from the zona glomerulosa of the adrenal gland.

Answer 425

Wide local excision and sentinel lymph node biopsy A small peripheral lesion such as this would usually be suitable for breast conserving surgery. Since imaging and clinical examination is not suspicious for axillary disease, a sentinel lymph node biopsy should be performed.

Answer 426

Wide local excision and axillary node clearance Although the primary lesion is small enough for breast conserving surgery, the presence of overt axillary lymph node metastasis will attract a recommendation for axillary node clearance

Answer 427

Simple mastectomy and axillary node clearance A combination of established axillary disease and multifocal invasive lesions attracts an indication for mastectomy and axillary clearance. A radical mastectomy is less frequently indicated in modern surgical practice, disease that is locally advanced is often best downstaged using medical therapy, rather than embarking on the operations for breast cancer that were first popularised over 100 years ago.

Answer 428

Sudden arterial embolus will affect the axillary artery in up to 30% cases. Because of the acute nature of the condition there is no time for the development of a collateral circulation so the limb is usually pale and painful. Emboli occur usually occur as a result of atrial fibrillation. Fast atrial fibrillation can cause syncope and an acute embolus.

Answer 429

Cervical rib Compression of the thoracic outlet by the fibrous band of the “rib” can result in both neurological and circulatory compromise. When manual tasks are performed in which the hand works overhead the signs and symptoms will be maximal and this is the basis of Adsons test.

Answer 430

Raynaud’s disease Raynauds disease is characterised by a series of colour changes and discomfort is often present. The young age at presentation coupled with the absence of a smoking history (in most cases) makes occlusive disease unlikely.

Answer 431

Brachial artery

Answer 432

The quadratus femoris fibres pass laterally to be inserted into the quadrate tubercle on the intertrochanteric crest of the femur. The other muscles all insert on the trochanteric fossa lying medial to the greater trochanter. The mnemonic for the muscles that insert on the medial surface of the greater trochanter is indeed “POGO”: P: Piriformis O: Obturator internus G: Gemelli O: Obturator externus

Answer 433

Obturator externus

Answer 434

The vessels supplying the omentum are the omental branches of the right and left gastro-epiploic arteries. The colonic vessels are not responsible for the arterial supply to the omentum. The left gastro-epiploic artery is a branch of the splenic artery and the right gastro-epiploic artery is a terminal branch of the gastroduodenal artery.

Answer 435

Haemarthrosis without trauma is typically a feature of haemophilia A and B Without a history of trauma, ligamentous rupture or tibial plateau fractures would be unusual. Haemarthroses may occur in 45% of patients with severe von Willebrands disease. However, this is rare

Answer 436

The common carotid artery is a lateral relation of the inferior parathyroid.

Answer 437

The common iliac veins fuse with the IVC at L5.

Answer 438

The inferior thyroid artery is usually derived from the thyrocervical trunk, a branch of the subclavian artery. Thoracic aorta Origin T4 Terminates T12 Relations Anteriorly (from top to bottom)-root of the left lung, the pericardium, the oesophagus, and the diaphragm Posteriorly-vertebral column, azygos vein Right- azygos veins, thoracic duct Left- left pleura and lung Branches Lateral segmental branches: Posterior intercostal arteries Lateral visceral: Bronchial arteries supply bronchial walls and lung excluding the alveoli Midline branches: Oesophageal arteries

Answer 439

The musculi pectinati are found in the atria, hence the reason that the atrial walls in the right atrium are irregular anteriorly. The musculi pectinati of the atria are internal muscular ridges on the anterolateral surface of the chambers and they are only present in the area derived from the embryological true atrium. Heart anatomy The walls of each cardiac chamber comprise: Epicardium Myocardium Endocardium Cardiac muscle is attached to the cardiac fibrous skeleton. Relations The heart and roots of the great vessels within the pericardial sac are related to the posterior aspect of the sternum, medial ends of the 3rd to 5th ribs on the left and their associated costal cartilages. The heart and pericardial sac are situated obliquely two thirds to the left and one third to the right of the median plane. The pulmonary valve lies at the level of the left third costal cartilage. The mitral valve lies at the level of the fourth costal cartilage. Coronary sinus This lies in the posterior part of the coronary groove and receives blood from the cardiac veins. The great cardiac vein lies at its left and the middle and small cardiac veins lie on its right. The smallest cardiac vein (anterior cardiac vein) drains into the right atrium directly. Aortic sinus Right coronary artery arises from the right aortic sinus, the left is derived from the left aortic sinus, which lies posteriorly. Features of the left ventricle as opposed to the right Structure Left Ventricle A-V Valve Mitral (double leaflet) Walls Twice as thick as right Trabeculae carnae Much thicker and more numerous Right coronary artery The RCA supplies: Right atrium Diaphragmatic part of the right ventricle Usually the posterior third of the interventricular septum The sino atrial node (60% cases) The atrio ventricular node (80% cases) Left coronary artery The LCA supplies: Left atrium Most of left ventricle Part of the right ventricle Anterior two thirds of the inter ventricular septum The sino atrial node (remaining 40% cases) Innervation of the heart Autonomic nerve fibres from the superficial and deep cardiac plexus. These lie anterior to the bifurcation of the trachea, posterior to the ascending aorta and superior to the bifurcation of the pulmonary trunk. The parasympathetic supply to the heart is from presynaptic fibres of the vagus nerves. Valves of the heart Mitral valve Aortic valve Pulmonary valve Tricuspid valve 2 cusps 3 cusps 3 cusps 3 cusps First heart sound Second heart sound Second heart sound First heart sound 1 anterior cusp 2 anterior cusps 2 anterior cusps 2 anterior cusps Attached to chordae tendinae No chordae No chordae Attached to chordae tendinae

Answer 440

Anterior interosseous nerve The anterior interosseous nerve (volar interosseous nerve) is a branch of the median nerve that supplies the deep muscles on the front of the forearm, except the ulnar half of the flexor digitorum profundus. It accompanies the anterior interosseous artery along the anterior of the interosseous membrane of the forearm, in the interval between the flexor pollicis longus and flexor digitorum profundus, supplying the whole of the former and (most commonly) the radial half of the latter, and ending below in the pronator quadratus and wrist joint. Innervation The anterior interosseous nerve classically innervates 2.5 muscles: Flexor pollicis longus Pronator quadratus The radial half of flexor digitorum profundus (the lateral two out of the four tendons). These muscles are in the deep level of the anterior compartment of the forearm.

Answer 441

The posterior circumflex humeral vessels which are branches of the axillary artery are related to the axillary nerve within the quadrangular space. Axillary nerve Terminal branch of the posterior cord of the brachial plexus Root values C5 and C6 Descends posterior to the axillary artery at the lower border of subscapularis and then passes through quadrangular space with the posterior circumflex humeral vessels Divides into anterior and posterior branches Innervates deltoid muscle and small patch of skin over deltoid

Answer 442

Mycosis fungoides Oncoviruses Viruses which cause cancer These may be detected on blood test and prevented by vaccine These are the main types of oncoviruses and their diseases: Oncovirus Cancer Epstein-Barr virus Burkitt's lymphoma Hodgkin's lymphoma Post transplant lymphoma Nasopharyngeal carcinoma Human papillomavirus 16/18 Cervical cancer Anal cancer Penile cancer Vulval cancer Oropharyneal cancer Human herpes virus 8 Kaposi's sarcoma Hepatitis B virus Hepatocellular carcinoma Hepatitis C virus Hepatocellular carcinoma Human T-lymphotropic virus 1 Tropical spastic paraparesis Adult T cell leukaemia

Answer 443

Fixed mottling is a sign of an unsalvageable limb and mandates either amputation or palliation. A through knee amputation (Gritti Stokes) is unlikely to heal in this setting. Acute limb ischaemia - Thrombosis of a pre-existing site of atherosclerosis is the commonest cause of acute limb ischaemia Acute thrombosis of popliteal aneurysms poses the greatest threat to the limb Sudden occlusion of a large proximal vessel results in the typical appearances of acute limb ischaemia Clinical appearances Less than 6 hours = White leg At 6 -12 hours = Mottled limb with blanching on pressure More than 12-24 hours = Fixed mottling Management of acutely ischaemic leg Clinical picture Treatment White leg with sensorimotor deficit Surgery and embolectomy Dusky leg, mild anaesthesia Angiography Fixed mottling Primary amputation Role of thrombolysis Intra arterial thrombolysis is better than peripheral thrombolysis Mainly indicated in acute on chronic thrombosis Avoid if within 2 months of CVA or 2 weeks of surgery Aspiration of clot may improve success rate if the thrombosis is large Surgery Both groins should be prepared Transverse arteriotomy is easier to close Poor inflow should be managed with iliac trawl- if this fails to improve then consider a femoro-femoral cross over or axillo-femoral cross over. A check angiogram should be performed on table and prior to closure Systemic heparinisation should follow surgery Fasciotomy should be considered if the time between onset and surgery exceeds 6 hours

Answer 444

Excessive infusions of any intravenous fluid carry the risk of development of tissue oedema and potentially cardiac failure. Excessive administration of sodium chloride is a recognised cause of hyperchloraemic acidosis and therefore Hartmans solution may be preferred where large volumes of fluid are to be administered. Post operative fluid management Composition of commonly used intravenous fluids mmol-1 Na K Cl Bicarbonate Lactate Plasma 137-147 4-5.5 95-105 22-25 - 0.9% Saline 153 - 153 - - Dextrose / saline 30.6 - 30.6 - - Hartmans 130 4 110 - 28 Post operative fluid management In the UK the GIFTASUP and NICE (CG174 2017) guidelines (see reference below) were devised to try and provide some consensus guidance as to how intravenous fluids should be administered. Some time ago it was a commonly held belief that little harm would occur as a result of excessive administration of normal saline and many oliguric post operative patients received enormous quantities of IV fluids. As a result they developed hyperchloraemic acidosis. With greater understanding of this potential complication, the use of electrolyte balanced solutions (Ringers lactate/ Hartmans) is now favored over normal saline. The other guidance includes: Fluids given should be documented clearly and easily available Assess the patient's fluid status when they leave theatre If a patient is haemodynamically stable and euvolaemic, aim to restart oral fluid intake as soon as possible Review patients whose urinary sodium is < 20 If a patient is oedematous, hypovolaemia if present should be treated first. This should then be followed by a negative balance of sodium and water, monitored using urine Na excretion levels Solutions such as Dextran 70 should be used in caution in patients with sepsis as there is a risk of developing acute renal injury

Answer 445

The obturator nerve supplies sensation to the medial aspect of the thigh and causes adduction and internal rotation of the thigh. Injury occurs during pelvic or abdominal surgery. L3 cord compression is unlikely. Obturator nerve The obturator nerve arises from L2, L3 and L4 by branches from the ventral divisions of each of these nerve roots. L3 forms the main contribution and the second lumbar branch is occasionally absent. These branches unite in the substance of psoas major, descending vertically in its posterior part to emerge from its medial border at the lateral margin of the sacrum. It then crosses the sacroiliac joint to enter the lesser pelvis, it descends on obturator internus to enter the obturator groove. In the lesser pelvis the nerve lies lateral to the internal iliac vessels and ureter, and is joined by the obturator vessels lateral to the ovary or ductus deferens. Supplies Medial compartment of thigh Muscles supplied: external obturator, adductor longus, adductor brevis, adductor magnus (not the lower part-sciatic nerve), gracilis The cutaneous branch is often absent. When present, it passes between gracilis and adductor longus near the middle part of the thigh, and supplies the skin and fascia of the distal two thirds of the medial aspect. Obturator canal Connects the pelvis and thigh: contains the obturator artery, vein, nerve which divides into anterior and posterior branches.

Answer 446

Desmopressin is useful in managing the bleeding from the commonest type of vWD. Vasopressin is less likely to be disease specific and at most would have a vasoconstrictor approach which is likely to be of brief duration. von Willebrands disease - Most common inherited bleeding disorder All vWD is caused by mutations in the gene for von Willebrand factor. von Willebrand factor is an adhesive glycoprotein that is secreted by endothelium and megakaryocytes von Willebrand factor promotes platelet adhesion to damaged endothelium and other platelets. It is also involved in the transport and stabilization of factor VIII There are 7 subtypes of von Willebrand disease. The commonest is type I (autosomal dominant) which accounts for 80% of cases, type 2vWD (autosomal dominant or recessive) accounts for 15% of cases There is a significant spectrum of severity ranging from spontaneous bleeding and epistaxis through to troublesome excessive bleeding following minor procedures The test that is most commonly used are von willebrand factor assays Treatments include administration of tranexamic acid for minor cases undergoing minor procedures. More significant bleeding or more significant procedures respond well to DDAVP. This is most effective in type I, less effective in type 2 and contraindicated in type 2B. Patients with type 3 disease do not respond to DDAVP as they lack the ability to secrete vWF Individuals who cannot have DDAVP or in whom it is contra indicated usually receive factor VIII concentrates containing vWF

Answer 447

Adductor longus is supplied by the obturator nerve. Femoral nerve Root values L2, 3, 4 Innervates Pectineus Sartorius Quadriceps femoris Vastus lateralis/medialis/intermedius Rectus femoris Branches Medial cutaneous nerve of thigh Saphenous nerve Intermediate cutaneous nerve of thigh Path Penetrates psoas major and exits the pelvis by passing under the inguinal ligament to enter the femoral triangle, lateral to the femoral artery and vein. Mnemonic for femoral nerve supply (don't) M I S V Q Scan for PE M edial cutaneous nerve of the thigh I ntermediate cutaneous nerve of the thigh S aphenous nerve V astus Q uadriceps femoris S artorius PE ectineus

Answer 448

A patent urachus will present with umbilical urinary discharge. The skin may become macerated if not properly cared for. The discharge is most likely to be present when intra-abdominal pressure is raised. It is associated with posterior urethral valves. Paediatric umbilical disorders Embryology During development the umbilicus has two umbilical arteries and one umbilical vein. The arteries are continuous with the internal iliac arteries and the vein is continuous with the falciform ligament (ductus venosus). After birth the cord dessicates and separates and the umbilical ring closes. Umbilical hernia Up to 20% of neonates may have an umbilical hernia, it is more common in premature infants. The majority of these hernias will close spontaneously (may take between 12 months and three years). Strangulation is rare. Paraumbilical hernia These are due to defects in the linea alba that are in close proximity to the umbilicus. The edges of a paraumbilical hernia are more clearly defined than those of an umbilical hernia. They are less likely to resolve spontaneously than an umbilical hernia. Omphalitis This condition consists of infection of the umbilicus. Infection with Staphylococcus aureus is the commonest cause. The condition is potentially serious as infection may spread rapidly through the umbilical vessels in neonates with a risk of portal pyaemia, and portal vein thrombosis. Treatment is usually with a combination of topical and systemic antibiotics. Umbilical granuloma These consist of cherry red lesions surrounding the umbilicus, they may bleed on contact and be a site of seropurulent discharge. Infection is unusual and they will often respond favorably to chemical cautery with topically applied silver nitrate. Persistent urachus This is characterised by urinary discharge from the umbilicus. It is caused by persistence of the urachus which attaches to the bladder. They are associated with other urogenital abnormalities. Persistent vitello-intestinal duct This will typically present as an umbilical discharge that discharges small bowel content. Complete persistence of the duct is a rare condition. Much more common is the persistence of part of the duct (Meckels diverticulum). Persistent vitello-intestinal ducts are best imaged using a contrast study to delineate the anatomy and are managed by laparotomy and surgical closure.

Answer 449

A locally perforated colonic tumour will typically cause an intense inflammatory response and if peritonitis is not present clinically then at the very least a localised abscess. This inflammatory process is the most likely (from the list) to falsely raise the serum ferritin level. Angiodysplasia and dieulafoy lesions are mucosal arteriovenous malformations and unlikely to result in considerable inflammatory activity. Ferritin Ferritin is an intracellular protein that binds iron and stores it to be released in a controlled fashion at sites where iron is required. Because iron and ferritin are bound the total body ferritin levels may be decreased in cases of iron deficiency anaemia. Measurement of serum ferritin levels can be useful in determining whether an apparently low haemoglobin and microcytosis is truly caused by an iron deficiency state. Ferritin is an acute phase protein and may be synthesised in increased quantities in situations where inflammatory activity is ongoing. Falsely elevated results may therefore be encountered clinically and need to be taken in context of the clinical picture and full blood count results.

Answer 450

Pes anserinus: GOOSE'S FOOT Combination of sartorius, gracilis and semitendinous tendons inserting into the anteromedial proximal tibia. Pes Anserinus Bursitis is common in sportsmen due to overuse injuries. The main sign is of pain in the medial proximal tibia. As the McMurray test is negative, medial meniscal injury is excluded. Sartorius - Longest strap muscle in the body Most superficial muscle in the anterior compartment of the thigh Origin Anterior superior iliac spine Insertion Medial surface of the of the body of the tibia (upper part). It inserts anterior to gracilis and semitendinosus Nerve Supply Femoral nerve (L2,3 -root values for sartorius) Action Flexor of the hip and knee, slight abducts the thigh and rotates it laterally It assists with medial rotation of the tibia on the femur. For example it would play a pivotal role in placing the right heel onto the left knee ( and vice versa) Important relations The middle third of this muscle, and its strong underlying fascia forms the roof of the adductor canal , in which lie the femoral vessels, the saphenous nerve and the nerve to vastus medialis.

Answer 451

Painful third nerve palsy = posterior communicating artery aneurysm Given the combination of a headache and third nerve palsy it is important to exclude a posterior communicating artery aneurysm Third nerve palsy Features eye is deviated 'down and out' ptosis pupil may be dilated (sometimes called a 'surgical' third nerve palsy) Causes diabetes mellitus vasculitis e.g. temporal arteritis, SLE false localizing sign* due to uncal herniation through tentorium if raised ICP posterior communicating artery aneurysm (pupil dilated) cavernous sinus thrombosis Weber's syndrome: ipsilateral third nerve palsy with contralateral hemiplegia -caused by midbrain strokes other possible causes: amyloid, multiple sclerosis *this term is usually associated with sixth nerve palsies but it may be used for a variety of neurological presentations

Answer 452

Calculate routine maintenance IV fluid rates for children and young people using the HollidaySegar formula (100 ml/kg/day for the first 10 kg of weight, 50 ml/kg/day for the next 10 kg and 20 ml/kg/day for the weight over 20 kg). Be aware that over a 24hour period, males rarely need more than 2500 ml and females rarely need more than 2000 ml of fluids. From birth to day 1: 50-60 ml/kg/day. Day 2: 70-80 ml/kg/day. Day 3: 80-100 ml/kg/day. Day 4: 100-120 ml/kg/day. Days 5-8: 120-150 ml/kg/day. Paediatric fluid management Since 2000 there have been at least 4 reported deaths from fluid induced hyponatraemia in children. This led to the National Patient Safety Agency introducing revised guidelines in 2007. These have been reviewed and extensively updated by NICE in 2015 and further modified in 2020. Indications for IV fluids include: Resuscitation and circulatory support Replacing on-going fluid losses Maintenance fluids for children for whom oral fluids are not appropriate Correction of electrolyte disturbances Fluids to be avoided Outside the neonatal period saline / glucose solutions should not be given. The greatest risk is with saline 0.18 / glucose 4% solutions. The report states that 0.45% saline / 5% glucose may be used. But preference should be given to isotonic solutions and few indications exist for this solution either. The key point emphasised in the NICE guidelines in the avoidance of glucose containing solutions and instead of routinely giving glucose IV to children and neonates, the blood glucose levels should be monitored. In neonates in the first few days of life, sodium levels in the range of 131-154 mmol/l may be too high and a neonatologist consulted on a case by case basis. Fluids to be used If children and young people need IV fluids for routine maintenance, initially use isotonic crystalloids that contain sodium in the range 131 to 154 mmol/litre Potassium should be added to maintenance fluids according patients plasma potassium levels (which should be monitored). Blood glucose levels should be monitored in individuals at risk of hypoglycaemia Intraoperative fluid management If children and young people need IV fluids for routine maintenance, initially use isotonic crystalloids that contain sodium in the range 131 to 154 mmol/litre Blood glucose levels should be monitored Maintenance fluids Weight Water requirement/kg/day Na mmol/kg/day K mmol/kg/day First 10Kg body weight 100ml 2-4 1.5-2.5 Second 10Kg body weight 50ml 1-2 0.5-1.5 Subsequent Kg 20ml 0.5-1.0 0.2-0.7 Blood glucose will need to be monitored

Answer 453

Suprascapular nerve The suprascapular nerve arises from the upper trunk of the brachial plexus. It lies superior to the trunks of the brachial plexus and passes inferolaterally parallel to them. It passes through the scapular notch, deep to trapezius. It innervates both supraspinatus and infraspinatus and initiates abduction of the shoulder. If damaged, patients may be able to abduct the shoulder by leaning over the affected side and deltoid can then continue to abduct the shoulder.

Answer 454

Removal of metal work implantation of gentamicin beads and delayed revision is the mainstay of managing this complication after 4 weeks. In earlier infections, linear exchanges covered by prolonged courses of antibiotics can be used. Osteomyelitis Infection of the bone Causes S aureus and occasionally Enterobacter or Streptococcus species In sickle cell: Salmonella species Clinical features Erythema Pain Fever Investigation X-ray: lytic centre with a ring of sclerosis Bone biopsy and culture Treatment Prolonged antibiotics Sequestra may need surgical removal

Answer 455

A left sided varicocele is a recognised presenting sign of a renal tumour occluding the renal vein (into which the left testicular vein drains). An abdominal ultrasound should be undertaken to exclude this. Surgery for uncomplicated varicocele is usually unnecessary. Renal tumours Renal cell carcinoma Renal cell carcinoma is an adenocarcinoma of the renal cortex and is believed to arise from the proximal convoluted tubule. They are usually solid lesions, up to 20% may be multifocal, 20% may be calcified and 20% may have either a cystic component or be wholly cystic. They are often circumscribed by a pseudocapsule of compressed normal renal tissue. Spread may occur either by direct extension into the adrenal gland, renal vein or surrounding fascia. More distant disease usually occurs via the haematogenous route to lung, bone or brain. Renal cell carcinoma comprise up to 85% of all renal malignancies. Males are more commonly affected than females and sporadic tumours typically affect patients in their sixth decade. Patients may present with a variety of symptoms including; haematuria (50%), loin pain (40%), mass (30%) and up to 25% may have symptoms of metastasis.Less than 10% have the classic triad of haematuria, pain and mass. Investigation Many cases will present as haematuria and be discovered during diagnostic work up. Benign renal tumours are rare, so renal masses should be investigated with multislice CT scanning. Most tumours are also characterised with an arterial phase CT, particularly if they may be suitable for partial nephrectomy. CT scanning of the chest and abdomen to detect distant disease should also be undertaken. Routine bone scanning is not indicated in the absence of symptoms. Biopsy should not be performed when a nephrectomy is planned but is mandatory before any ablative therapies are undertaken. Assessment of the functioning of the contra lateral kidney. Management T1 lesions may be managed by partial nephrectomy and this gives equivalent oncological results to total radical nephrectomy. Partial nephrectomy may also be performed when there is inadequate reserve in the remaining kidney. Ablative techniques may also be considered for small T1 lesions in unfit patients. In general, outcomes are less favorable than with surgical resection. For T2 lesions and above a radical nephrectomy is standard practice and this may be performed via a laparoscopic or open approach. Preoperative embolisation is not indicated nor is resection of uninvolved adrenal glands. During surgery early venous control is mandatory to avoid shedding of tumour cells into the circulation. Patients with completely resected disease do not benefit from adjuvant therapy with either chemotherapy or biological agents. These should not be administered outside the setting of clinical trials. Patients with transitional cell cancer will require a nephroureterectomy with disconnection of the ureter at the bladder.

Answer 456

Note the question asks for initial management The initial management of open fractures should include administration of intravenous antibiotics, photography of wound and application of a sterile soaked gauze and impermeable film. The wound should only be handled to remove gross contamination. The patient is then likely to require definitive skeletal and soft tissue reconstruction. Open fractures The term open fracture refers to a disruption of the bony cortex associated with a breach in the overlying skin. Any wound that is present in the same limb as a fracture should be suspected as being representative of an open fracture. One of the main problems with open fractures is the associated injuries to the surrounding soft tissues. Whilst the skin is usually relatively resistant to trauma, underlying muscle can be damaged or devitalised, nerves, blood vessels and periosteum may all be disrupted the degree to which this occurs correlates with the severity of the injury and the outcome. These can be graded using the Gustilo and Anderson system (see below). Grade Injury 1 Low energy wound <1cm 2 Greater than 1cm wound with moderate soft tissue damage 3 High energy wound > 10cm with extensive soft tissue damage 3 A (sub group of 3) Adequate soft tissue coverage 3 B (sub group of 3) Inadequate soft tissue coverage 3 C (sub group of 3) Associated arterial injury In Type IIIc injuries, the mangled extremity scoring system (MESS) can help to predict the need for primary amputation. Key points for initial management Remove obvious contaminants from very contaminated wounds in the ED Wound lavage should usually be undertaken in the OR Early wound photography should be performed Consider transfer of complex cases to centres that provide orthoplastic care All wounds should be managed within 24 hours and high velocity ones within 12 hours, those with vascular compromise should be managed immediately CT angiography is useful in delineating the extent of concommitant vascular injury

Answer 457

Beta blockers should not be stopped acutely prior to surgery as there may be a rebound effect associated with increased complications. Brain natriuretic peptide is a neurohormone synthesized in the cardiac ventricles. Levels have been used to assess prognosis in heart failure and acute coronary syndromes. Preoperative elevated brain natriuretic peptide levels identify patients undergoing non cardiac surgery at high risk of cardiac mortality and all cause mortality. All patients with peripheral vascular disease should take statins prior to vascular surgery as studies have shown a 50% risk reduction and a reduction in perioperative cardiac events. Proactive care of older people undergoing surgery (POPS) Comprehensive geriatric assessment MDT assessment preoperatively Main predictors of complications are co-morbidities cardiac disease and reduced functional capacity - preoperative assessment is the key to preventing adverse postoperative outcomes Patients screened for risk factors (albumin <30, co morbidities) Management plan made and disseminated to all involved Patients education: pain relief, post op exercises, nutrition Outcomes: Fewer postoperative medical complications Reduced length of stay by 4.5 days

Answer 458

It is used in arteriovenous fistula surgery during a procedure known as a basilic vein transposition. Basilic vein The basilic and cephalic veins both provide the main pathways of venous drainage for the arm and hand. It is continuous with the palmar venous arch distally and the axillary vein proximally. Path Originates on the medial side of the dorsal venous network of the hand, and passes up the forearm and arm. Most of its course is superficial. Near the region anterior to the cubital fossa the vein joins the cephalic vein. Midway up the humerus the basilic vein passes deep under the muscles. At the lower border of the teres major muscle, the anterior and posterior circumflex humeral veins feed into it. It is often joined by the medial brachial vein before draining into the axillary vein.

Answer 459

This describes a relative afferent pupillary defect (RAPD). RAPD is a defect in the direct response to light. It is due to damage in optic nerve or severe retinal disease. If an optic nerve lesion is present the affected pupil will not constrict to light when light is shone in the that pupil during the swinging flashlight test. However, it will constrict if light is shone in the other eye (consensual response). The most likely cause for this is an optic neuritis (not really surgical!). Other causes include ischemic optic disease or retinal disease, severe glaucoma causing trauma to optic nerve and direct optic nerve damage (trauma, radiation, tumor). Cranial nerves Cranial nerve lesions Olfactory nerve May be injured in basal skull fractures or involved in frontal lobe tumour extension. Loss of olfactory nerve function in relation to major CNS pathology is seldom an isolated event and thus it is poor localiser of CNS pathology. Optic nerve Problems with visual acuity may result from intra ocular disorders. Problems with the blood supply such as amaurosis fugax may produce temporary visual distortion. More important surgically is the pupillary response to light. The pupillary size may be altered in a number of disorders. Nerves involved in the resizing of the pupil connect to the pretectal nucleus of the high midbrain, bypassing the lateral geniculate nucleus and the primary visual cortex. From the pretectal nucleus neurones pass to the Edinger - Westphal nucleus, motor axons from here pass along with the oculomotor nerve. They synapse with ciliary ganglion neurones; the parasympathetic axons from this then innervate the iris and produce miosis. The miotic pupil is seen in disorders such as Horner's syndrome or opiate overdose. Mydriasis is the dilatation of the pupil in response to disease, trauma, drugs (or the dark!). It is pathological when light fails to induce miosis. The radial muscle is innervated by the sympathetic nervous system. Because the parasympathetic fibres travel with the oculomotor nerve they will be damaged by lesions affecting this nerve (e.g. cranial trauma). The response to light shone in one eye is usually a constriction of both pupils. This indicates intact direct and consensual light reflexes. When the optic nerve has an afferent defect the light shining on the affected eye will produce a diminished pupillary response in both eyes. Whereas light shone on the unaffected eye will produce a normal pupillary response in both eyes. This is referred to as the Marcus Gunn pupil and is seen in conditions such as optic neuritis. In a total CN II lesion shining the light in the affected eye will produce no response. Oculomotor nerve The pupillary effects are described above. In addition it supplies all ocular muscles apart from lateral rectus and superior oblique. Thus the affected eye will be deviated inferolaterally. Levator palpebrae superioris may also be impaired resulting in impaired ability to open the eye. Trochlear nerve The eye will not be able to look down. Trigeminal nerve Largest cranial nerve. Exits the brainstem at the pons. Branches are ophthalmic, maxillary and mandibular. Only the mandibular branch has both sensory and motor fibres. Branches converge to form the trigeminal ganglion (located in Meckels cave). It supplies the muscles of mastication and also tensor veli palatine, mylohyoid, anterior belly of digastric and tensor tympani. The detailed descriptions of the various sensory functions are described in other areas of the website. The corneal reflex is important and is elicited by applying a small tip of cotton wool to the cornea, a reflex blink should occur if it is intact. It is mediated by: the naso ciliary branch of the ophthalmic branch of the trigeminal (sensory component) and the facial nerve producing the motor response. Lesions of the afferent arc will produce bilateral absent blink and lesions of the efferent arc will result in a unilateral absent blink. Abducens nerve The affected eye will have a deficit of abduction. This cranial nerve exits the brainstem between the pons and medulla. It thus has a relatively long intra cranial course which renders it susceptible to damage in raised intra cranial pressure. Facial nerve Emerges from brainstem between pons and medulla. It controls muscles of facial expression and taste from the anterior 2/3 of the tongue. The nerve passes into the petrous temporal bone and into the internal auditory meatus. It then passes through the facial canal and exits at the stylomastoid foramen. It passes through the parotid gland and divides at this point. It does not innervate the parotid gland. Its divisions are considered in other parts of the website. Its motor fibres innervate orbicularis oculi to produce the efferent arm of the corneal reflex. In surgical practice it may be injured during parotid gland surgery or invaded by malignancies of the gland and a lower motor neurone on the ipsilateral side will result. Vestibulo-cochlear nerve Exits from the pons and then passes through the internal auditory meatus. It is implicated in sensorineural hearing loss. Individuals with sensorineural hearing loss will localise the sound in webers test to the normal ear. Rinnes test will be reduced on the affected side but should still work. These two tests will distinguish sensorineural hearing loss from conductive deafness. In the latter condition webers test will localise to the affected ear and Rinnes test will be impaired on the affected side. Surgical lesions affecting this nerve include CNS tumours and basal skull fractures. It may also be damaged by the administration of ototoxic drugs (of which gentamicin is the most commonly used in surgical practice). Glossopharyngeal nerve Exits the pons just above the vagus. Receives sensory fibres from posterior 1/3 tongue, tonsils, pharynx and middle ear (otalgia may occur following tonsillectomy). It receives visceral afferents from the carotid bodies. It supplies parasympathetic fibres to the parotid gland via the otic ganglion and motor function to stylopharyngeaus muscle. The sensory function of the nerve is tested using the gag reflex. Vagus nerve Leaves the medulla between the olivary nucleus and the inferior cerebellar peduncle. Passes through the jugular foramen and into the carotid sheath. Details of the functions of the vagus nerve are covered in the website under relevant organ sub headings. Accessory nerve Exists from the caudal aspect of the brainstem (multiple branches) supplies trapezius and sternocleidomastoid muscles. The distal portion of this nerve is most prone to injury during surgical procedures. Hypoglossal nerve Emerges from the medulla at the preolivary sulcus, passes through the hypoglossal canal. It lies on the carotid sheath and passes deep to the posterior belly of digastric to supply muscles of the tongue (except palatoglossus). Its location near the carotid sheath makes it vulnerable during carotid endarterectomy surgery and damage will produce ipsilateral defect in muscle function.

Answer 460

Sibson's fascia overlies the apices of both lungs The suprapleural fascia (Sibson's fascia) runs from C7 to the first rib and overlies the apex of both lungs.It lies between the parietal pleura and the thoracic cage. Lung anatomy The right lung is composed of 3 lobes divided by the oblique and transverse fissures. The left lung has two lobes divided by the oblique fissure.The apex of both lungs is approximately 4cm superior to the sterno-costal joint of the first rib. Immediately below this is a sulcus created by the subclavian artery. Peripheral contact points of the lung Base: diaphragm Costal surface: corresponds to the cavity of the chest Mediastinal surface: Contacts the mediastinal pleura. Has the cardiac impression. Above and behind this concavity is a triangular depression named the hilum, where the structures which form the root of the lung enter and leave the viscus. These structures are invested by pleura, which, below the hilum and behind the pericardial impression, forms the pulmonary ligament Right lung Above the hilum is the azygos vein; Superior to this is the groove for the superior vena cava and right innominate vein; behind this, and nearer the apex, is a furrow for the innominate artery. Behind the hilum and the attachment of the pulmonary ligament is a vertical groove for the oesophagus; In front and to the right of the lower part of the oesophageal groove is a deep concavity for the extrapericardiac portion of the inferior vena cava. The root of the right lung lies behind the superior vena cava and the right atrium, and below the azygos vein. The right main bronchus is shorter, wider and more vertical than the left main bronchus and therefore the route taken by most foreign bodies. Left lung Above the hilum is the furrow produced by the aortic arch, and then superiorly the groove accommodating the left subclavian artery; Behind the hilum and pulmonary ligament is a vertical groove produced by the descending aorta, and in front of this, near the base of the lung, is the lower part of the oesophagus. The root of the left lung passes under the aortic arch and in front of the descending aorta. Inferior borders of both lungs 6th rib in mid clavicular line 8th rib in mid axillary line 10th rib posteriorly The pleura runs two ribs lower than the corresponding lung level. Bronchopulmonary segments Segment number Right lung Left lung 1 Apical Apical 2 Posterior Posterior 3 Anterior Anterior 4 Lateral Superior lingular 5 Medial Inferior lingular 6 Superior (apical) Superior (apical) 7 Medial basal Medial basal 8 Anterior basal Anterior basal 9 Lateral basal Lateral basal 10 Posterior basal Posterior basal

Answer 461

Abducens. The long intracranial course of this nerve makes it susceptible to damage early in the course of raised ICP. Cranial nerves Cranial nerve lesions Olfactory nerve May be injured in basal skull fractures or involved in frontal lobe tumour extension. Loss of olfactory nerve function in relation to major CNS pathology is seldom an isolated event and thus it is poor localiser of CNS pathology. Optic nerve Problems with visual acuity may result from intra ocular disorders. Problems with the blood supply such as amaurosis fugax may produce temporary visual distortion. More important surgically is the pupillary response to light. The pupillary size may be altered in a number of disorders. Nerves involved in the resizing of the pupil connect to the pretectal nucleus of the high midbrain, bypassing the lateral geniculate nucleus and the primary visual cortex. From the pretectal nucleus neurones pass to the Edinger - Westphal nucleus, motor axons from here pass along with the oculomotor nerve. They synapse with ciliary ganglion neurones; the parasympathetic axons from this then innervate the iris and produce miosis. The miotic pupil is seen in disorders such as Horner's syndrome or opiate overdose. Mydriasis is the dilatation of the pupil in response to disease, trauma, drugs (or the dark!). It is pathological when light fails to induce miosis. The radial muscle is innervated by the sympathetic nervous system. Because the parasympathetic fibres travel with the oculomotor nerve they will be damaged by lesions affecting this nerve (e.g. cranial trauma). The response to light shone in one eye is usually a constriction of both pupils. This indicates intact direct and consensual light reflexes. When the optic nerve has an afferent defect the light shining on the affected eye will produce a diminished pupillary response in both eyes. Whereas light shone on the unaffected eye will produce a normal pupillary response in both eyes. This is referred to as the Marcus Gunn pupil and is seen in conditions such as optic neuritis. In a total CN II lesion shining the light in the affected eye will produce no response. Oculomotor nerve The pupillary effects are described above. In addition it supplies all ocular muscles apart from lateral rectus and superior oblique. Thus the affected eye will be deviated inferolaterally. Levator palpebrae superioris may also be impaired resulting in impaired ability to open the eye. Trochlear nerve The eye will not be able to look down. Trigeminal nerve Largest cranial nerve. Exits the brainstem at the pons. Branches are ophthalmic, maxillary and mandibular. Only the mandibular branch has both sensory and motor fibres. Branches converge to form the trigeminal ganglion (located in Meckels cave). It supplies the muscles of mastication and also tensor veli palatine, mylohyoid, anterior belly of digastric and tensor tympani. The detailed descriptions of the various sensory functions are described in other areas of the website. The corneal reflex is important and is elicited by applying a small tip of cotton wool to the cornea, a reflex blink should occur if it is intact. It is mediated by: the naso ciliary branch of the ophthalmic branch of the trigeminal (sensory component) and the facial nerve producing the motor response. Lesions of the afferent arc will produce bilateral absent blink and lesions of the efferent arc will result in a unilateral absent blink. Abducens nerve The affected eye will have a deficit of abduction. This cranial nerve exits the brainstem between the pons and medulla. It thus has a relatively long intra cranial course which renders it susceptible to damage in raised intra cranial pressure. Facial nerve Emerges from brainstem between pons and medulla. It controls muscles of facial expression and taste from the anterior 2/3 of the tongue. The nerve passes into the petrous temporal bone and into the internal auditory meatus. It then passes through the facial canal and exits at the stylomastoid foramen. It passes through the parotid gland and divides at this point. It does not innervate the parotid gland. Its divisions are considered in other parts of the website. Its motor fibres innervate orbicularis oculi to produce the efferent arm of the corneal reflex. In surgical practice it may be injured during parotid gland surgery or invaded by malignancies of the gland and a lower motor neurone on the ipsilateral side will result. Vestibulo-cochlear nerve Exits from the pons and then passes through the internal auditory meatus. It is implicated in sensorineural hearing loss. Individuals with sensorineural hearing loss will localise the sound in webers test to the normal ear. Rinnes test will be reduced on the affected side but should still work. These two tests will distinguish sensorineural hearing loss from conductive deafness. In the latter condition webers test will localise to the affected ear and Rinnes test will be impaired on the affected side. Surgical lesions affecting this nerve include CNS tumours and basal skull fractures. It may also be damaged by the administration of ototoxic drugs (of which gentamicin is the most commonly used in surgical practice). Glossopharyngeal nerve Exits the pons just above the vagus. Receives sensory fibres from posterior 1/3 tongue, tonsils, pharynx and middle ear (otalgia may occur following tonsillectomy). It receives visceral afferents from the carotid bodies. It supplies parasympathetic fibres to the parotid gland via the otic ganglion and motor function to stylopharyngeaus muscle. The sensory function of the nerve is tested using the gag reflex. Vagus nerve Leaves the medulla between the olivary nucleus and the inferior cerebellar peduncle. Passes through the jugular foramen and into the carotid sheath. Details of the functions of the vagus nerve are covered in the website under relevant organ sub headings. Accessory nerve Exists from the caudal aspect of the brainstem (multiple branches) supplies trapezius and sternocleidomastoid muscles. The distal portion of this nerve is most prone to injury during surgical procedures. Hypoglossal nerve Emerges from the medulla at the preolivary sulcus, passes through the hypoglossal canal. It lies on the carotid sheath and passes deep to the posterior belly of digastric to supply muscles of the tongue (except palatoglossus). Its location near the carotid sheath makes it vulnerable during carotid endarterectomy surgery and damage will produce ipsilateral defect in muscle function.

Answer 462

Hepatitis B Hepatitis B is a double-stranded DNA virus and is spread through exposure to infected blood or body fluids, including vertical transmission from mother to child. The incubation period is 6-20 weeks. Immunisation against hepatitis B Contains HBsAg absorbed onto aluminium hydroxide adjuvant and is prepared from yeast cells using recombinant DNA technology Most schedules give 3 doses of the vaccine with a recommendation for a one-off booster 5 years following the initial primary vaccination At risk groups who should be vaccinated include: healthcare workers, intravenous drug users, sex workers, close family contacts of an individual with hepatitis B, individuals receiving blood transfusions regularly, chronic kidney disease patients who may soon require renal replacement therapy, prisoners, chronic liver disease patients Around 10-15% of adults fail to respond or respond poorly to 3 doses of the vaccine. Risk factors include age over 40 years, obesity, smoking, alcohol excess and immunosuppression Testing for anti-HBs is only recommended for those at risk of occupational exposure (i.e. Healthcare workers) and patients with chronic kidney disease. In these patients anti-HBs levels should be checked 1-4 months after primary immunisation The table below shows how to interpret anti-HBs levels: Anti-HBs level (mIU/ml) Response > 100 Indicates adequate response, no further testing required. Should still receive booster at 5 years 10 - 100 Suboptimal response - one additional vaccine dose should be given. If immunocompetent no further testing is required < 10 Non-responder. Test for current or past infection. Give further vaccine course (i.e. 3 doses again) with testing following. If still fails to respond then HBIG would be required for protection if exposed to the virus Complications of hepatitis B infection Chronic hepatitis (5-10%) Fulminant liver failure (1%) Hepatocellular carcinoma Glomerulonephritis Polyarteritis nodosa Cryoglobulinaemia Management of hepatitis B Pegylated interferon-alpha used to be the only treatment available. It reduces viral replication in up to 30% of chronic carriers. A better response is predicted by being female, < 50 years old, low HBV DNA levels, non-Asian, HIV negative, high degree of inflammation on liver biopsy However, due to the side-effects of pegylated interferon it is now used less commonly in clinical practice. Oral antiviral medication is increasingly used with an aim to suppress viral replication (not in dissimilar way to treating HIV patients) Examples include lamivudine, tenofovir and entecavir

Answer 463

The appendix is derived from the midgut It is derived from the midgut which is why early appendicitis may present with periumbilical pain. Appendix Location: Base of caecum. Up to 10cm long. Mainly lymphoid tissue (Hence mesenteric adenitis may mimic appendicitis). Caecal taenia coli converge at base of appendix and form a longitudinal muscle cover over the appendix. This convergence should facilitate its identification at surgery if it is retrocaecal and difficult to find (which it can be when people start doing appendicectomies!) Arterial supply: Appendicular artery (branch of the ileocolic). It is intra peritoneal. McBurney's point 1/3 of the way along a line drawn from the Anterior Superior Iliac Spine to the Umbilicus 6 Positions: Retrocaecal 74% Pelvic 21% Postileal Subcaecal Paracaecal Preileal

Answer 464

Mnemonic branches off the posterior cord S ubscapular (upper and lower) T horacodorsal A xillary R adial The musculocutaneous nerve is a branch off the lateral cord. Brachial plexus The brachial plexus extends from the neck to the axilla. It is formed by the ventral rami of the fifth to the eighth cervical nerves with the ascending part of the first thoracic nerve. Location of the plexus The ventral rami which form the plexus enter the lower part of the posterior triangle of the neck in series with the ventral rami of the cervical plexus. The second part of the subclavian artery lies immediately anterior to the lower two rami. The upper three rami intermingle and pass inferolaterally towards the axilla and subclavian artery. They are enclosed within an extension of the prevertebral fascia. In the neck the plexus lies deep to platysma, the supraclavicular nerves, inferior belly of omohyoid and the transverse cervical artery. It then passes deep to the clavicle and the suprascapular vessels, to enter the axilla, and thence surround the second part of the axillary artery Composition of the plexus Ventral rami, the roots of the plexus, lie between scalenus medius and anterior. As they enter the posterior triangle, the upper two (C5,6) and lower two (C8, T1) roots of the plexus unite to form the upper and lower trunks of the plexus respectively. Meanwhile, C7 continues as the middle trunk. The lower trunk may groove the superior surface of the first rib posterior to the subclavian artery, and the root from the first ventral ramus is always in contact with it. Each trunk divides into ventral and dorsal divisions which are destined to supply the anterior (flexor) and posterior (extensor) parts of the upper limb. The cords of the plexus are formed in the axilla. The dorsal divisions unite to form the posterior cord (C5-8). The ventral divisions of the upper and middle trunks unite to form the lateral cord (C5-7), while the ventral divisions of the lower trunk continues as the medial cord (C8-T1). The cords are named according to their relationship to the axillary artery. Each cord terminates by dividing into two main branches at the beginning of the third part of the artery. Sympathetic communications The fifth and sixth cervical ventral rami receive grey rami communicantes from the middle cervical ganglion, while the two or more grey rami communicantes pass from the inferior cervical ganglion to the seventh and eighth cervical ventral rami. The first thoracic ventral ramus receives its grey ramus from the cervicothoracic ganglion. Its for this reason that inferior plexus injury can be complicated by a Horners syndrome. Summary Origin Anterior rami of C5 to T1 Sections of the plexus Roots, trunks, divisions, cords, branches Mnemonic:Real Teenagers Drink Cold Beer Roots Located in the posterior triangle Pass between scalenus anterior and medius Trunks Located posterior to middle third of clavicle Upper and middle trunks related superiorly to the subclavian artery Lower trunk passes over 1st rib posterior to the subclavian artery Divisions Apex of axilla Cords Related to axillary artery

Answer 465

Enhanced recovery regimes try and avoid excessive IV fluids. These increase the rates of ileus in GI surgery. The oral route is preferred where possible. Enhanced recovery programmes Many surgical specialties have developed or adopted an enhanced recovery approach following procedures. Whilst the exact aspects differ according to the specialty involved, the broad principles remain the same. Pre admission Aim to optimise nutrition and any pre existing conditions. Prehabilitation programmes are used in some centres. Unit visits can be helpful to ensure patients know what to expect following the procedure. Admission In many cases admission on the day of the procedure is desirable and as near to the time of the procedure as possible. Procedure related preparation Try to minimise starvation times if GA is to be used. In many cases a carbohydrate loading drink is given 2 hours pre procedure. This is usually omitted in diabetic patients who are on complex insulin regimes. For GI surgery, it is desirable to avoid mechanical bowel preparation unless this is essential. Procedure Minimally invasive procedures are preferred and sufficient analgesia to facilitate early ambulation. Avoid excessive IV fluids during the procedure as this can result in interstitial oedema and increase complication rates. Post procedure Aim for early ambulation, early removal of drains, catheters and IV lines where possible. Restart oral nutrition as soon as possible. Encourage patients to dress and walk about ward.

Answer 466

The prostatic and membranous urethra drain to the internal iliac nodes. Urethral anatomy Female urethra The female urethra is shorter and more acutely angulated than the male urethra. It is an extra-peritoneal structure and embedded in the endopelvic fascia. The neck of the bladder is subjected to transmitted intra-abdominal pressure and therefore deficiency in this area may result in stress urinary incontinence. Between the layers of the urogenital diaphragm the female urethra is surrounded by the external urethral sphincter, this is innervated by the pudendal nerve. It ultimately lies anterior to the vaginal orifice. Male urethra In males the urethra is much longer and is divided into four parts. Pre-prostatic urethra Extremely short and lies between the bladder and prostate gland.It has a stellate lumen and is between 1 and 1.5cm long.Innervated by sympathetic noradrenergic fibres, as this region is composed of striated muscles bundles they may contract and prevent retrograde ejaculation. Prostatic urethra This segment is wider than the membranous urethra and contains several openings for the transmission of semen (at the midpoint of the urethral crest). Membranous urethra Narrowest part of the urethra and surrounded by external sphincter. It traverses the perineal membrane 2.5cm postero-inferior to the symphysis pubis. Penile urethra Travels through the corpus spongiosum on the underside of the penis. It is the longest urethral segment.It is dilated at its origin as the infrabulbar fossa and again in the glans penis as the navicular fossa. The bulbo-urethral glands open into the spongiose section of the urethra 2.5cm below the perineal membrane. The urothelium is transitional in nature near to the bladder and becomes squamous more distally.

Answer 467

Orchidopexy can be quite uncomfortable immediately following surgery. A caudal block can be a very effective adjunct and provides good analgesia. A spinal block and epidural would be inappropriate. A TAP block may cover the inguinal canal but this is not generally reliable and wound catheters are not used. Management of pain World Health Organisation Analgesic Ladder Initially peripherally acting drugs such as paracetamol or non-steroidal anti-inflammatory drugs (NSAIDs) are given. If pain control is not achieved, the second part of the ladder is to introduce weak opioid drugs such as codeine or dextropropoxyphene together with appropriate agents to control and minimise side effects. The final rung of the ladder is to introduce strong opioid drugs such as morphine. Analgesia from peripherally acting drugs may be additive to that from centrally-acting opioids and thus, the two are given together. The World Federation of Societies of Anaesthesiologists (WFSA) Analgesic Ladder For management of acute pain Initially, the pain can be expected to be severe and may need controlling with strong analgesics in combination with local anaesthetic blocks and peripherally acting drugs. The second rung on the postoperative pain ladder is the restoration of the use of the oral route to deliver analgesia. Strong opioids may no longer be required and adequate analgesia can be obtained by using combinations of peripherally acting agents and weak opioids. The final step is when the pain can be controlled by peripherally acting agents alone. Local anaesthetics Infiltration of a wound with a long-acting local anaesthetic such as Bupivacaine Analgesia for several hours Further pain relief can be obtained with repeat injections or by infusions via a thin catheter Blockade of plexuses or peripheral nerves will provide selective analgesia in those parts of the body supplied by the plexus or nerves Can either be used to provide anaesthesia for the surgery or specifically for postoperative pain relief Especially useful where a sympathetic block is needed to improve postoperative blood supply or where central blockade such as spinal or epidural blockade is contraindicated. Spinal anaesthesia Provides excellent analgesia for surgery in the lower half of the body and pain relief can last many hours after completion of the operation if long-acting drugs containing vasoconstrictors are used. - Side effects of spinal anaesthesia include: hypotension, sensory and motor block, nausea and urinary retention. Epidural anaesthesia An indwelling epidural catheter inserted. This can then be used to provide a continuous infusion of analgesic agents. It can provide excellent analgesia. They are still the preferred option following major open abdominal procedures and help prevent post operative respiratory compromise resulting from pain. - Disadvantages of epidurals is that they usually confine patients to bed, especially if a motor block is present. In addition an indwelling urinary catheter is required. Which may not only impair mobility but also serve as a conduit for infection. They are contraindicated in coagulopathies. Transversus Abdominal Plane block (TAP) In this technique an ultrasound is used to identify the correct muscle plane and local anaesthetic (usually bupivicaine) is injected. The agent diffuses in the plane and blocks many of the spinal nerves. It is an attractive technique as it provides a wide field of blockade but does not require the placement of any indwelling devices. There is no post operative motor impairment. For this reason it is the preferred technique when extensive laparoscopic abdominal procedures are performed. They will then provide analgesia immediately following surgery but as they do not confine the patient to bed, the focus on enhanced recovery can begin sooner. -The main disadvantage is that their duration of action is limited to the half life of the local anaesthetic agent chosen. In addition some anaesthetists do not have the USS skills required to site the injections. Patient Controlled Analgesia (PCA) - Patients administer their own intravenous analgesia and titrate the dose to their own end-point of pain relief using a small microprocessor - controlled pump. Morphine is the most popular drug used. Strong Opioids Severe pain arising from deep or visceral structures requires the use of strong opioids Morphine Short half life and poor bioavailability. Metabolised in the liver and clearance is reduced in patients with liver disease, in the elderly and the debilitated Side effects include nausea, vomiting, constipation and respiratory depression. Tolerance may occur with repeated dosage Pethidine Synthetic opioid which is structurally different from morphine but which has similar actions. Has 10% potency of morphine. Short half life and similar bioavailability and clearance to morphine. Short duration of action and may need to be given hourly. Pethidine has a toxic metabolite (norpethidine) which is cleared by the kidney, but which accumulates in renal failure or following frequent and prolonged doses and may lead to muscle twitching and convulsions. Extreme caution is advised if pethidine is used over a prolonged period or in patients with renal failure. Weak opioids Codeine: markedly less active than morphine, has predictable effects when given orally and is effective against mild to moderate pain. Non opioid analgesics - Mild to moderate pain. Paracetamol Inhibits prostaglandin synthesis. Analgesic and antipyretic properties but little anti-inflammatory effect It is well absorbed orally and is metabolised almost entirely in the liver Side effects in normal dosage and is widely used for the treatment of minor pain. It causes hepatotoxicity in over dosage by overloading the normal metabolic pathways with the formation of a toxic metabolite. NSAIDs Analgesic and anti-inflammatory actions Inhibition of prostaglandin synthesis by the enzyme Cyclooxygenase which catalyses the conversion of arachidonic acid to the various prostaglandins that are the chief mediators of inflammation. All NSAIDs work in the same way and thus there is no point in giving more than one at a time. . NSAIDs are, in general, more useful for superficial pain arising from the skin, buccal mucosa, joint surfaces and bone. Relative contraindications: history of peptic ulceration, gastrointestinal bleeding or bleeding diathesis; operations associated with high blood loss, asthma, moderate to severe renal impairment, dehydration and any history of hypersensitivity to NSAIDs or aspirin. Neuropathic pain National Institute of Clinical Excellence (UK) guidelines: First line: Amitriptyline (Imipramine if cannot tolerate) or pregabalin Second line: Amitriptyline AND pregabalin Third line: refer to pain specialist. Give tramadol in the interim (avoid morphine) If diabetic neuropathic pain: Duloxetine As of 1 April 2019, pregabalin and gabapentin are Class C controlled substances (under the Misuse of Drugs Act 1971) and scheduled under the Misuse of Drugs Regulations 2001 as Schedule 3. Evaluate patients carefully for a history of drug abuse before prescribing and observe patients for development of signs of abuse and dependence (MHRA, Drug Safety Update April 2019).

Answer 468

Relations of median nerve to the brachial artery: Lateral -> Anterior -> Medial The median nerve descends lateral to the brachial artery, it usually passes anterior to the artery to lie on its medial side. It passes deep to the bicipital aponeurosis and the median cubital vein at the elbow. It enters the forearm between the two heads of the pronator teres muscle. Brachial artery The brachial artery begins at the lower border of teres major as a continuation of the axillary artery. It terminates in the cubital fossa at the level of the neck of the radius by dividing into the radial and ulnar arteries. Relations Posterior relations include the long head of triceps with the radial nerve and profunda vessels intervening. Anteriorly it is overlapped by the medial border of biceps. It is crossed by the median nerve in the middle of the arm. In the cubital fossa it is separated from the median cubital vein by the bicipital aponeurosis. The basilic vein is in contact at the most proximal aspect of the cubital fossa and lies medially.

Answer 469

Dopamine: Dopamine, acting as a PRL-inhibitory factor (PIF), inhibits prolactin release. When dopamine levels decrease (such as during suckling), there is a disinhibition effect, leading to prolactin secretion12. Thyrotropin Releasing Hormone (TRH): TRH, produced by the hypothalamus, stimulates the release of prolactin. Additionally, oestrogens enhance lactotroph sensitivity to TRH and reduce their sensitivity to dopamine inhibition1. In summary, dopamine suppresses prolactin, while TRH and oestrogens promote its release. The other hormones listed (luteinizing hormone and follicle-stimulating hormone) do not directly influence prolactin13. Remember, prolactin plays a crucial role in breast development, milk production, and other physiological processes, particularly in females Prolactin Prolactin is a peptide hormone released from the anterior pituitary. It is under tonic dopamine inhibition, thyrotropin releasing hormone has a stimulatory effect on release. Prolactin release stimulates milk production but also reduces gonadal activity. It decreases GnRH pulsatility at the hypothalamic level and to a lesser extent, blocks the action of LH on the ovary or testis.

Answer 470

The most likely lesion to occur in the cerebello-pontine angle is an acoustic neuroma. The trigeminal nerve has a broad base and involvement of at least part of this nerve is the most likely initial finding. The defect may be subtle such as loss of the ipsilateral corneal reflex. Ipsilateral hearing loss will also occur. Untreated, progressive lesions, may ultimately affect cranial nerve roots in this region. Cranial nerves Cranial nerve lesions Olfactory nerve May be injured in basal skull fractures or involved in frontal lobe tumour extension. Loss of olfactory nerve function in relation to major CNS pathology is seldom an isolated event and thus it is poor localiser of CNS pathology. Optic nerve Problems with visual acuity may result from intra ocular disorders. Problems with the blood supply such as amaurosis fugax may produce temporary visual distortion. More important surgically is the pupillary response to light. The pupillary size may be altered in a number of disorders. Nerves involved in the resizing of the pupil connect to the pretectal nucleus of the high midbrain, bypassing the lateral geniculate nucleus and the primary visual cortex. From the pretectal nucleus neurones pass to the Edinger - Westphal nucleus, motor axons from here pass along with the oculomotor nerve. They synapse with ciliary ganglion neurones; the parasympathetic axons from this then innervate the iris and produce miosis. The miotic pupil is seen in disorders such as Horner's syndrome or opiate overdose. Mydriasis is the dilatation of the pupil in response to disease, trauma, drugs (or the dark!). It is pathological when light fails to induce miosis. The radial muscle is innervated by the sympathetic nervous system. Because the parasympathetic fibres travel with the oculomotor nerve they will be damaged by lesions affecting this nerve (e.g. cranial trauma). The response to light shone in one eye is usually a constriction of both pupils. This indicates intact direct and consensual light reflexes. When the optic nerve has an afferent defect the light shining on the affected eye will produce a diminished pupillary response in both eyes. Whereas light shone on the unaffected eye will produce a normal pupillary response in both eyes. This is referred to as the Marcus Gunn pupil and is seen in conditions such as optic neuritis. In a total CN II lesion shining the light in the affected eye will produce no response. Oculomotor nerve The pupillary effects are described above. In addition it supplies all ocular muscles apart from lateral rectus and superior oblique. Thus the affected eye will be deviated inferolaterally. Levator palpebrae superioris may also be impaired resulting in impaired ability to open the eye. Trochlear nerve The eye will not be able to look down. Trigeminal nerve Largest cranial nerve. Exits the brainstem at the pons. Branches are ophthalmic, maxillary and mandibular. Only the mandibular branch has both sensory and motor fibres. Branches converge to form the trigeminal ganglion (located in Meckels cave). It supplies the muscles of mastication and also tensor veli palatine, mylohyoid, anterior belly of digastric and tensor tympani. The detailed descriptions of the various sensory functions are described in other areas of the website. The corneal reflex is important and is elicited by applying a small tip of cotton wool to the cornea, a reflex blink should occur if it is intact. It is mediated by: the naso ciliary branch of the ophthalmic branch of the trigeminal (sensory component) and the facial nerve producing the motor response. Lesions of the afferent arc will produce bilateral absent blink and lesions of the efferent arc will result in a unilateral absent blink. Abducens nerve The affected eye will have a deficit of abduction. This cranial nerve exits the brainstem between the pons and medulla. It thus has a relatively long intra cranial course which renders it susceptible to damage in raised intra cranial pressure. Facial nerve Emerges from brainstem between pons and medulla. It controls muscles of facial expression and taste from the anterior 2/3 of the tongue. The nerve passes into the petrous temporal bone and into the internal auditory meatus. It then passes through the facial canal and exits at the stylomastoid foramen. It passes through the parotid gland and divides at this point. It does not innervate the parotid gland. Its divisions are considered in other parts of the website. Its motor fibres innervate orbicularis oculi to produce the efferent arm of the corneal reflex. In surgical practice it may be injured during parotid gland surgery or invaded by malignancies of the gland and a lower motor neurone on the ipsilateral side will result. Vestibulo-cochlear nerve Exits from the pons and then passes through the internal auditory meatus. It is implicated in sensorineural hearing loss. Individuals with sensorineural hearing loss will localise the sound in webers test to the normal ear. Rinnes test will be reduced on the affected side but should still work. These two tests will distinguish sensorineural hearing loss from conductive deafness. In the latter condition webers test will localise to the affected ear and Rinnes test will be impaired on the affected side. Surgical lesions affecting this nerve include CNS tumours and basal skull fractures. It may also be damaged by the administration of ototoxic drugs (of which gentamicin is the most commonly used in surgical practice). Glossopharyngeal nerve Exits the pons just above the vagus. Receives sensory fibres from posterior 1/3 tongue, tonsils, pharynx and middle ear (otalgia may occur following tonsillectomy). It receives visceral afferents from the carotid bodies. It supplies parasympathetic fibres to the parotid gland via the otic ganglion and motor function to stylopharyngeaus muscle. The sensory function of the nerve is tested using the gag reflex. Vagus nerve Leaves the medulla between the olivary nucleus and the inferior cerebellar peduncle. Passes through the jugular foramen and into the carotid sheath. Details of the functions of the vagus nerve are covered in the website under relevant organ sub headings. Accessory nerve Exists from the caudal aspect of the brainstem (multiple branches) supplies trapezius and sternocleidomastoid muscles. The distal portion of this nerve is most prone to injury during surgical procedures. Hypoglossal nerve Emerges from the medulla at the preolivary sulcus, passes through the hypoglossal canal. It lies on the carotid sheath and passes deep to the posterior belly of digastric to supply muscles of the tongue (except palatoglossus). Its location near the carotid sheath makes it vulnerable during carotid endarterectomy surgery and damage will produce ipsilateral defect in muscle function.

Answer 471

Metaraminol is an alpha receptor agonist. As a general rule, inotropes and vasopressors can only be administered via a central vein. Metaraminol is an exception to this as it can be administered via a peripheral line. Circulatory support of the critically ill Circulatory support Impaired tissue oxygenation may occur as a result of circulatory shock. Shock is considered further under its own topic heading. Patients requiring circulatory support require haemodynamic monitoring. At its simplest level this may simply be in the form of regular urine output measurements and blood pressure monitoring. In addition ECG monitoring will allow the identification of cardiac arrhythmias. Pulse oximeter measurements will allow quick estimation haemoglobin oxygen saturation in arterial blood. Invasive arterial blood pressure monitoring is undertaken by the use of an indwelling arterial line. Most arterial sites can be used although the radial artery is the commonest. It is important not to cannulate end arteries. The arterial trace can be tracked to ventilation phases and those patients whose systolic pressure varies with changes in intrathoracic pressure may benefit from further intravenous fluids. Central venous pressure is measured using a CVP line that is usually sited in the superior vena cava via the internal jugular route. The CVP will demonstrate right atrial filling pressure and volume status. When adequate intra vascular volume is present a fluid challenge will typically cause a prolonged rise in CVP (usually greater than 6-8mmHg). To monitor the cardiac output a Swan-Ganz catheter is traditionally inserted (other devices may be used and are less invasive). Inflation of the distal balloon will provide the pulmonary artery occlusion pressure and the pressure distal to the balloon will equate to the left atrial pressure. This gives a measure of left ventricular preload. Because the Swan-Ganz catheter can measure several variables it can be used to calculate: Stroke volume Systemic vascular resistance Pulmonary artery resistance Oxygen delivery (and consumption) Inotropes In patients with an adequate circulating volume but on-going circulatory compromise a vasoactive drug may be considered. These should usually be administered via the central venous route. Commonly used inotropes include: Agent Mode of action Effect Noradrenaline α agonist Vasopressor action, minimal effect on cardiac output Adrenaline α and β receptor agonist Increases cardiac output and peripheral vascular resistance Dopamine β1 agonist Increases contractility and rate Dobutamine β1 and β2 agonist Increases cardiac output and decreases SVR Milrinone Phosphodiesterase inhibitor Elevation of cAMP levels improves muscular contractility, short half life and acts as vasodilator

Answer 472

Pregabalin is generally the first line agent for neuropathic pain. Management of pain World Health Organisation Analgesic Ladder Initially peripherally acting drugs such as paracetamol or non-steroidal anti-inflammatory drugs (NSAIDs) are given. If pain control is not achieved, the second part of the ladder is to introduce weak opioid drugs such as codeine or dextropropoxyphene together with appropriate agents to control and minimise side effects. The final rung of the ladder is to introduce strong opioid drugs such as morphine. Analgesia from peripherally acting drugs may be additive to that from centrally-acting opioids and thus, the two are given together. The World Federation of Societies of Anaesthesiologists (WFSA) Analgesic Ladder For management of acute pain Initially, the pain can be expected to be severe and may need controlling with strong analgesics in combination with local anaesthetic blocks and peripherally acting drugs. The second rung on the postoperative pain ladder is the restoration of the use of the oral route to deliver analgesia. Strong opioids may no longer be required and adequate analgesia can be obtained by using combinations of peripherally acting agents and weak opioids. The final step is when the pain can be controlled by peripherally acting agents alone. Local anaesthetics Infiltration of a wound with a long-acting local anaesthetic such as Bupivacaine Analgesia for several hours Further pain relief can be obtained with repeat injections or by infusions via a thin catheter Blockade of plexuses or peripheral nerves will provide selective analgesia in those parts of the body supplied by the plexus or nerves Can either be used to provide anaesthesia for the surgery or specifically for postoperative pain relief Especially useful where a sympathetic block is needed to improve postoperative blood supply or where central blockade such as spinal or epidural blockade is contraindicated. Spinal anaesthesia Provides excellent analgesia for surgery in the lower half of the body and pain relief can last many hours after completion of the operation if long-acting drugs containing vasoconstrictors are used. - Side effects of spinal anaesthesia include: hypotension, sensory and motor block, nausea and urinary retention. Epidural anaesthesia An indwelling epidural catheter inserted. This can then be used to provide a continuous infusion of analgesic agents. It can provide excellent analgesia. They are still the preferred option following major open abdominal procedures and help prevent post operative respiratory compromise resulting from pain. - Disadvantages of epidurals is that they usually confine patients to bed, especially if a motor block is present. In addition an indwelling urinary catheter is required. Which may not only impair mobility but also serve as a conduit for infection. They are contraindicated in coagulopathies. Transversus Abdominal Plane block (TAP) In this technique an ultrasound is used to identify the correct muscle plane and local anaesthetic (usually bupivicaine) is injected. The agent diffuses in the plane and blocks many of the spinal nerves. It is an attractive technique as it provides a wide field of blockade but does not require the placement of any indwelling devices. There is no post operative motor impairment. For this reason it is the preferred technique when extensive laparoscopic abdominal procedures are performed. They will then provide analgesia immediately following surgery but as they do not confine the patient to bed, the focus on enhanced recovery can begin sooner. -The main disadvantage is that their duration of action is limited to the half life of the local anaesthetic agent chosen. In addition some anaesthetists do not have the USS skills required to site the injections. Patient Controlled Analgesia (PCA) - Patients administer their own intravenous analgesia and titrate the dose to their own end-point of pain relief using a small microprocessor - controlled pump. Morphine is the most popular drug used. Strong Opioids Severe pain arising from deep or visceral structures requires the use of strong opioids Morphine Short half life and poor bioavailability. Metabolised in the liver and clearance is reduced in patients with liver disease, in the elderly and the debilitated Side effects include nausea, vomiting, constipation and respiratory depression. Tolerance may occur with repeated dosage Pethidine Synthetic opioid which is structurally different from morphine but which has similar actions. Has 10% potency of morphine. Short half life and similar bioavailability and clearance to morphine. Short duration of action and may need to be given hourly. Pethidine has a toxic metabolite (norpethidine) which is cleared by the kidney, but which accumulates in renal failure or following frequent and prolonged doses and may lead to muscle twitching and convulsions. Extreme caution is advised if pethidine is used over a prolonged period or in patients with renal failure. Weak opioids Codeine: markedly less active than morphine, has predictable effects when given orally and is effective against mild to moderate pain. Non opioid analgesics - Mild to moderate pain. Paracetamol Inhibits prostaglandin synthesis. Analgesic and antipyretic properties but little anti-inflammatory effect It is well absorbed orally and is metabolised almost entirely in the liver Side effects in normal dosage and is widely used for the treatment of minor pain. It causes hepatotoxicity in over dosage by overloading the normal metabolic pathways with the formation of a toxic metabolite. NSAIDs Analgesic and anti-inflammatory actions Inhibition of prostaglandin synthesis by the enzyme Cyclooxygenase which catalyses the conversion of arachidonic acid to the various prostaglandins that are the chief mediators of inflammation. All NSAIDs work in the same way and thus there is no point in giving more than one at a time. . NSAIDs are, in general, more useful for superficial pain arising from the skin, buccal mucosa, joint surfaces and bone. Relative contraindications: history of peptic ulceration, gastrointestinal bleeding or bleeding diathesis; operations associated with high blood loss, asthma, moderate to severe renal impairment, dehydration and any history of hypersensitivity to NSAIDs or aspirin. Neuropathic pain National Institute of Clinical Excellence (UK) guidelines: First line: Amitriptyline (Imipramine if cannot tolerate) or pregabalin Second line: Amitriptyline AND pregabalin Third line: refer to pain specialist. Give tramadol in the interim (avoid morphine) If diabetic neuropathic pain: Duloxetine As of 1 April 2019, pregabalin and gabapentin are Class C controlled substances (under the Misuse of Drugs Act 1971) and scheduled under the Misuse of Drugs Regulations 2001 as Schedule 3. Evaluate patients carefully for a history of drug abuse before prescribing and observe patients for development of signs of abuse and dependence (MHRA, Drug Safety Update April 2019). References 1. http://guidance.nice.org.uk/CG173/Guidance/pdf/English 2. Lovich-Sapola J, Smith CE, Brandt CP. Post operative pain control. Surg Clin North Am. 2015 Apr;95(2):301-183. Finnerup N et al. Pharmacotherapy for neuropathic pain in adults: a systematic review and meta-analysis. Lancet Neurol. 2015 Feb;14(2):162-73.

Answer 473

Suspicious naevi should NOT be partially sampled as histological interpretation is severely compromised. Complete excision is mandatory where lesions fulfil diagnostic criteria. However, wide excision for margins may be deferred until definitive histology is available. Lesions that are suspicious for melanoma should be excised with complete margins. Radical excision is not routinely undertaken for diagnostic purposes and therefore if subsequent histopathological assessment determines that the lesion is a melanoma a re-exicision of margins may be required. Incisional punch biopsies of potential melanomas makes histological interpretation difficult and is best avoided Malignant melanoma The main diagnostic features (major criteria): Change in size Change in shape Change in colour Secondary features (minor criteria) Diameter >6mm Inflammation Oozing or bleeding Altered sensation Treatment Suspicious lesions should undergo excision biopsy. The lesion should be removed in completely as incision biopsy can make subsequent histopathological assessment difficult. Once the diagnosis is confirmed the pathology report should be reviewed to determine whether further re-excision of margins is required (see below): Margins of excision-Related to Breslow thickness Lesions 0-1mm thick 1cm Lesions 1-2mm thick 1- 2cm (Depending upon site and pathological features) Lesions 2-4mm thick 2-3 cm (Depending upon site and pathological features) Lesions >4 mm thick 3cm Marsden J et al Revised UK guidelines for management of Melanoma. Br J Dermatol 2010 163:238-256. Further treatments such as sentinel lymph node mapping, isolated limb perfusion and block dissection of regional lymph node groups should be selectively applied. Guidelines The UK NICE guidance is covered by Melanoma: assessment and management NICE guideline [NG14]. However, the complex oncological regimens are not extensively covered in this guidance though more formal guidance is provided by relevant oncological organisations.

Answer 474

Embryological origin stapes = 2nd pharyngeal arch The ectoderm covering the outer aspect of the second arch originates from a strip of ectoderm lateral to the metencephalic neural fold. The cartilaginous element to this, eponymously known as Reicherts cartilage extends from the otic capsule to the midline on each side. Its dorsal end separates and becomes enclosed in the tympanic cavity as the stapes. The dorsal ends of the cartilages of the first and second pharyngeal arches articulate superior to the tubotympanic recess. These cartilages form the malleus, incus and stapes. At least part of the malleus is formed from the first arch and the stapes from the second arch. The incus is most likely to arise from the first arch. Pharyngeal arches These develop during the fourth week of embryonic growth from a series of mesodermal outpouchings of the developing pharynx. They develop and fuse in the ventral midline. Pharyngeal pouches form on the endodermal side between the arches. There are 6 pharyngeal arches, the fifth does not contribute any useful structures and often fuses with the sixth arch. Pharyngeal arches Pharyngeal arch Muscular contributions Skeletal contributions Endocrine Artery Nerve First Muscles of mastication Anterior belly of digastric Mylohyoid Tensor tympanic Tensor veli palatini Maxilla Meckels cartilage Incus Malleus n/a Maxillary External carotid Mandibular Second Buccinator Platysma Muscles of facial expression Stylohyoid Posterior belly of digastric Stapedius Stapes Styloid process Lesser horn and upper body of hyoid n/a Inferior branch of superior thyroid artery Stapedial artery Facial Third Stylopharyngeus Greater horn and lower part of hyoid Thymus Inferior parathyroids Common and internal carotid Glossopharyngeal Fourth Cricothyroid All intrinsic muscles of the soft palate Thyroid and epiglottic cartilages Superior parathyroids Right- subclavian artery, Left-aortic arch Vagus Sixth All intrinsic muscles of the larynx (except cricothyroid) Cricoid, arytenoid and corniculate cartilages n/a Right -Pulmonary artery, Left- Pulmonary artery and ductus arteriosus Vagus and recurrent laryngeal nerve

Answer 475

Since the distal humerus is affected, the radial is at risk. Eponymous fractures Colles' fracture (dinner fork deformity) Fall onto extended outstretched hand Classical Colles' fractures have the following 3 features: 1. Transverse fracture of the radius 2. 1 inch proximal to the radio-carpal joint 3. Dorsal displacement and angulation Smith's fracture (reverse Colles' fracture) Volar angulation of distal radius fragment (Garden spade deformity) Caused by falling backwards onto the palm of an outstretched hand or falling with wrists flexed Bennett's fracture Intra-articular fracture of the first carpometacarpal joint Impact on flexed metacarpal, caused by fist fights Monteggia's fracture Dislocation of the proximal radioulnar joint in association with an ulna fracture Fall on outstretched hand with forced pronation Needs prompt diagnosis to avoid disability Galeazzi fracture Radial shaft fracture with associated dislocation of the distal radioulnar joint Direct blow Pott's fracture Bimalleolar ankle fracture Forced foot eversion Barton's fracture Distal radius fracture (Colles'/Smith's) with associated radiocarpal dislocation Fall onto extended and pronated wrist Involvement of the joint is a defining feature Holstein Lewis Fracture A HolsteinLewis fracture is a fracture of the distal third of the humerus resulting in entrapment of the radial nerve. The radial nerve is one of the major nerves of the upper limb. It innervates all of the muscles in the extensor compartments of the arm. Conservative treatment includes reduction and use of a functional brace Vascular injury may require open surgery

Answer 476

Surface anatomy of the neck In the midline from above down, the following structures are felt Structure Level Hyoid C3 Notch of the thyroid cartilage C4 Cricoid cartilage(termination) C6 The lower border of the cricoid cartilage corresponds to the commencement of the trachea and also to the following: Junction of larynx with trachea Junction of pharynx with oesophagus Level at which the inferior thyroid artery enters the thyroid gland The level at which the vertebral artery enters the transverse foramen in the 6th cervical vertebra Level at which the superior belly of omohyoid crosses the carotid sheath The level of the middle cervical sympathetic ganglion The level at which the carotid artery can be compressed against the transverse process of C6 (carotid tubercle).

Answer 477

Decreased sodium. Aldosterone affects the parotid gland secretions and has the effect of conserving sodium (so salivary sodium reduced) and potassium secretion increased. Parotid gland secretions - Parotid gland secretions account for around 25% of salivary secretions Levels of sodium and chloride are lower than plasma, potassium and bicarbonate levels are higher Parotid secretions are watery and have high enzyme concentrations Parasympathetic stimulation produces a water rich, serous saliva. Sympathetic stimulation leads to the production of a low volume, enzyme-rich saliva. Fluid that is secreted within the acini is isotonic with plasma and undergoes modification within the ducts via process of ion exchange The ducts are affected by aldosterone and so will retain sodium and secrete potassium when aldosterone levels are elevated

Answer 478

The veins that drain into the sinus are important as sepsis can cause cavernous sinus thrombosis. The maxillary branch of the trigeminal and not the mandibular branches pass through the sinus Cavernous sinus The cavernous sinuses are paired and are situated on the body of the sphenoid bone. It runs from the superior orbital fissure to the petrous temporal bone. Relations Medial Lateral Pituitary fossa Sphenoid sinus Temporal lobe Contents Lateral wall components (from top to bottom:) Oculomotor nerve Trochlear nerve Ophthalmic nerve Maxillary nerve Contents of the sinus (from medial to lateral:) Internal carotid artery (and sympathetic plexus) Abducens nerve Blood supply Ophthalmic vein, superficial cortical veins, basilar plexus of veins posteriorly. Drains into the internal jugular vein via: the superior and inferior petrosal sinuses

Answer 479

It is generally accepted that proximal pole fractures of the scaphoid should be surgically fixed as non union rates of up to 34% can be seen when cast immobilization alone is attempted. Scaphoid fractures - Incidence of scaphoid fractures in UK ranges from 12.4 per 100,000 to 29 per 100,000 Surface of scaphoid is covered by articular cartilage with small area available for blood vessels (fracture risks blood supply) Forms floor of anatomical snuffbox Risk of fracture associated with fall onto outstretched hand (tubercle, waist, or proximal third) A series of 4 scaphoid radiographs should be undertaken (PA, pronated oblique, Ziter view and lateral view). The Ziter view is a PA view with the wrist in ulnar deviation and beam angulated at 20 degrees Sensitivity of scaphoid radiographs in 1st week of injury is 80% Immobilization of scaphoid fractures difficult Repeat imaging should be done at 10 days. MRI should be done in cases of diagnostic uncertainty Classification of scaphoid fractures Scaphoid tubercle Distal pole Waist Proximal pole Management Undisplaced fractures of the waist of the scaphoid and most distal pole fractures can be managed in a cast for 6 weeks with high rates of union. Displaced scaphoid waist fractures (more than 1-2mm) should be viewed as unstable and surgically fixed. All proximal pole fractures should be fixed surgically. Complications Non union of scaphoid Avascular necrosis of the scaphoid Scapholunate disruption and wrist collapse Degenerative changes of the adjacent joint

Answer 480

The obturator nerve exits through the obturator foramen. Greater sciatic foramen Contents Nerves Sciatic Nerve Superior and Inferior Gluteal Nerves Pudendal Nerve Posterior Femoral Cutaneous Nerve Nerve to Quadratus Femoris Nerve to Obturator internus Vessels Superior Gluteal Artery and vein Inferior Gluteal Artery and vein Internal Pudendal Artery and vein Piriformis The piriformis is a landmark for identifying structures passing out of the sciatic notch Above piriformis: Superior gluteal vessels Below piriformis: Inferior gluteal vessels, sciatic nerve (10% pass through it, <1% above it), posterior cutaneous nerve of the thigh Greater sciatic foramen boundaries Anterolaterally Greater sciatic notch of the ilium Posteromedially Sacrotuberous ligament Inferior Sacrospinous ligament and the ischial spine Superior Anterior sacroiliac ligament Structures passing between both foramina (Medial to lateral) Pudendal nerve Internal pudendal artery Nerve to obturator internus Contents of the lesser sciatic foramen Tendon of the obturator internus Pudendal nerve Internal pudendal artery and vein Nerve to the obturator internus

Answer 481

JVP: C wave - closure of the tricuspid valve The c wave of the jugular venous waveform is associated with the closure of the tricuspid valve. Jugular venous pressure As well as providing information on right atrial pressure, the jugular vein waveform may provide clues to underlying valvular disease. A non-pulsatile JVP is seen in superior vena caval obstruction. Kussmaul's sign describes a paradoxical rise in JVP during inspiration seen in constrictive pericarditis 'a' wave = atrial contraction large if atrial pressure e.g. tricuspid stenosis, pulmonary stenosis, pulmonary hypertension absent if in atrial fibrillation Cannon 'a' waves caused by atrial contractions against a closed tricuspid valve are seen in complete heart block, ventricular tachycardia/ectopics, nodal rhythm, single chamber ventricular pacing 'c' wave closure of tricuspid valve not normally visible 'v' wave due to passive filling of blood into the atrium against a closed tricuspid valve giant v waves in tricuspid regurgitation 'x' descent = fall in atrial pressure during ventricular systole 'y' descent = opening of tricuspid valve

Answer 482

Most surgeons would excise a mass of this size rather than attempt biopsy. Further information relating to adrenal masses is covered under this topic. Tissue sampling Tissue sampling is an important surgical process. Biopsy modalities vary according to the site, experience and subsequent planned therapeutic outcome The modalities comprise: -Fine needle aspiration cytology -Core biopsy -Excision biopsy -Tru cut biopsy -Punch biopsy -Cytological smears -Endoscopic or laparoscopic biopsy When the lesion is superficial the decision needs to be taken as to whether complete excision is desirable or whether excision biopsy is acceptable. In malignant melanoma for example the need for safe margins will mean that a more radical surgical approach needs to be adopted after diagnostic confirmation from excision biopsy than would be the case in basal cell carcinoma. Punch biopsies are useful in gaining histological diagnosis of unclear skin lesions where excision biopsy is undesirable such as in establishing whether a skin lesion is vasculitic or not. Fine needle aspiration cytology (FNAC) is an operator dependent procedure that may or may not be image guided and essentially involves passing a needle through a lesion whilst suction is applied to a syringe. The material thus obtained is expressed onto a slide and sent for cytological assessment. This test can be limited by operator inexperience and also by the lack of histological architectural information (e.g. Follicular carcinoma of the thyroid). Where a discharge is present a sample may be sent for cytology although in some sites (e.g. Nipple discharge ) the information gleaned may be meaningless. Tissue samples may be obtained by both core and tru cut biopsy. A core biopsy is obtained by use of a spring loaded gun with a needle passing quickly through the lesion of interest. A tru cut biopsy achieves the same objective but the needle moved by hand. When performing these techniques image guidance may be desirable (e.g. In breast lesions). Consideration needs to be given to any planned surgical resection as it may be necessary to resect the biopsy tract along with the specimen (e.g. In sarcoma surgery). Visceral lesions may be accessed percutaneously under image guidance such as ultrasound guided biopsy of liver metastases. Or under direct vision such as a colonoscopic biopsy.

Answer 483

Intestinal malrotation with volvulus is treated with a Ladd's procedure. Intestinal malrotation in neonates Normal embryology During the fourth week of embryogenesis the intestine moves into the abdomen via the base of the umbilicus. Through a combination of foetal growth and bowel maturation the bowel resides in the abdominal cavity and undergoes a 270o counterclockwise twist. At the conclusion of this process the ligament of Treitz lies to the left of the spine and the caecum in the right lower quadrant. Malrotation occurs when the rotational process described is incomplete. Typically the duodenal loop lies to the left of the caecum and therefore lacks 90 o of its 270o rotation. It becomes fixed in this position with peritoneal attachments (Ladds bands). Symptoms Bilious vomiting is the cardinal symptom and sign. In most cases there are no antecedent symptoms. If untreated then gut perfusion may be impaired with resultant development of further symptoms. Diagnosis The main problem is that the infant develops mid gut volvulus. In this situation the bowel undergoes a 720o twist, the bowel viability depends upon a narrow mesentery containing the superior mesenteric artery. To ascertain whether this has occurred the two main tests include an abdominal ultrasound scan to determine the relationship between the superior mesenteric artery and vein (normally SMA lies to the left of the SMV). This test is complemented with an upper GI contrast series and this aims to establish that the DJ flexure is correctly sited to the left of the vertebral bodies. Treatment Laparotomy and division of adhesional bands (Ladds procedure). The division of the congenital adhesions allows widening of the small bowel mesentery. The bowel is untwisted and assessed for viability. The bowel is returned to the abdominal cavity in the non rotated fashion with the small bowel on the right hand side and the large bowel on the left, the caecum is positioned in the left upper quadrant. Because the caecum is located in this new location many surgeons will also perform an appendicectomy due to the diagnostic difficulty posed in diagnosing appendicitis in this group of patients.

Answer 484

Transfer factor raised: asthma, haemorrhage, left-to-right shunts, polycythaemia low: everything else Where alveolar haemorrhage occurs the TLCO tends to increase due to the enhanced uptake of carbon monoxide by intra-alveolar haemoglobin. Transfer factor The transfer factor describes the rate at which a gas will diffuse from alveoli into blood. Carbon monoxide is used to test the rate of diffusion. Results may be given as the total gas transfer (TLCO) or that corrected for lung volume (transfer coefficient, KCO) Causes of a raised TLCO asthma pulmonary haemorrhage (Wegener's, Goodpasture's) left-to-right cardiac shunts polycythaemia hyperkinetic states male gender, exercise Causes of a lower TLCO pulmonary fibrosis pneumonia pulmonary emboli pulmonary oedema emphysema anaemia low cardiac output KCO also tends to increase with age. Some conditions may cause an increased KCO with a normal or reduced TLCO pneumonectomy/lobectomy scoliosis/kyphosis neuromuscular weakness ankylosis of costovertebral joints e.g. ankylosing spondylitis

Answer 485

Pain out of proportion to physical signs, AF and generalized abdominal pain suggest widespread infarction. Acute abdominal pain-diagnoses Conditions presenting with acute abdominal pain Condition Features Investigations Management Appendicitis History of migratory pain. Fever. Anorexia. Evidence of right iliac fossa tenderness. Mild pyrexia. Differential white cell count Pregnancy test C-Reactive protein Amylase Urine dipstick testing Appendicectomy Mesenteric adenitis Usually recent upper respiratory tract infection. High fever. Generalised abdominal discomfort- true localised pain and signs are rare. Full blood count- may show slightly raised white cell count Urine dipstick often normal Abdominal ultrasound scan - usually no free fluid Conservative management- appendicectomy if diagnostic doubt Mittelschmerz Only seen in females Mid cycle pain Usually occurs two weeks after last menstrual period Pain usually has a supra-pubic location Usually subsides over a 24-48 hour period. Full blood count- normal Urine dipstick- normal Abdominal and pelvic ultrasound- may show a trace of pelvic free fluid Manage conservatively if doubt or symptoms fail to settle then laparoscopy Fitz-Hugh Curtis syndrome Disseminated infection with Chlamydia. Usually seen in females. Consists of evidence of pelvic inflammatory disease together with peri-hepatic inflammation and subsequent adhesion formation. Abdominal ultrasound scan- may show free fluid High vaginal swabs - may show evidence of sexually transmitted infections Usually medically managed- doxycycline or azithromycin Abdominal aortic aneurysm (ruptured) Sudden onset of abdominal pain radiating to the back in older adults (look for risk factors). Collapse. May be moribund on arrival in casualty, more stable if contained haematoma. Careful clinical assessment may reveal pulsatile mass. Patients who are haemodynamically stable should have a CT scan Unstable patients should undergo immediate surgery (unless it is not in their best interests). Those with evidence of contained leak on CT should undergo immediate surgery Increasing unruptured aneurysmal size is an indication for urgent surgical intervention (that can wait until the next working day) Perforated peptic ulcer Sudden onset of pain (usually epigastric). Often preceding history of upper abdominal pain. Soon develop generalised abdominal pain. On examination may have clinical evidence of peritonitis. Erect CXR may show free air. A CT scan may be indicated where there is diagnostic doubt Laparotomy (laparoscopic surgery for perforated peptic ulcers is both safe and feasible in experienced hands) Intestinal obstruction Colicky abdominal pain and vomiting (the nature of which depends on the level of the obstruction). Abdominal distension and constipation (again depending upon site of obstruction). Features of peritonism may occur where local necrosis of bowel loops is occurring. A plain abdominal film may help with making the diagnosis. A CT scan may be useful where diagnostic uncertainty exists In those with a virgin abdomen a lower and earlier threshold for laparotomy should exist than in those who may have adhesional obstruction Mesenteric infarction Embolic events present with sudden pain and forceful evacuation. Acute on chronic events usually have a longer history and previous weight loss. On examination the pain is typically greater than the physical signs would suggest. Arterial pH and lactate Arterial phase CT scanning is the most sensitive test

Answer 486

The inferior mesenteric artery leaves the aorta at L3. It supplies the left colon and sigmoid. Its proximal continuation to communicate with the middle colic artery is via the marginal artery. Levels Transpyloric plane Level of the body of L1 Pylorus stomach Left kidney hilum (L1- left one!) Fundus of the gallbladder Neck of pancreas Duodenojejunal flexure Superior mesenteric artery Portal vein Left and right colic flexure Root of the transverse mesocolon 2nd part of the duodenum Upper part of conus medullaris Spleen Can be identified by asking the supine patient to sit up without using their arms. The plane is located where the lateral border of the rectus muscle crosses the costal margin. Anatomical planes Subcostal plane Lowest margin of 10th costal cartilage Intercristal plane Level of body L4 (highest point of iliac crest) Intertubercular plane Level of body L5 Common level landmarks Inferior mesenteric artery L3 Bifurcation of aorta into common iliac arteries L4 Formation of IVC L5 (union of common iliac veins) Diaphragm apertures Vena cava T8 Oesophagus T10 Aortic hiatus T12

Answer 487

This patient has pre-existing joint disease, good level of activity and a relatively high life expectancy, therefore THR is preferable to hemiarthroplasty. Hip fractures Background Neck of femur (NOF) fracture is a common orthopaedic presentation, with over 65000 fractures in the UK per year. Like many orthopaedic injuries, there is a bimodal age distribution. It is imperative to distinguish between the high energy injury in a young patient, and the low energy osteoporotic fracture in the elderly, as their management aims are very different: Young patient - Usually high energy trauma (e.g road traffic accident, horse riding) and needs treating in accordance with Advanced Trauma Life Support (ATLS) principles. Will often have associated injuries. Aim is to retain the patients own anatomy, and optimise their function. Elderly patient - Predominantly female, fall from standing height (fragility fracture). Often patients have multiple comorbidities that will ultimately dictate their prognosis. Aim of orthopaedic treatment is to immediately regain patient mobility so that morbidity (infection, thromboembolic events, pressure sores etc) and mortality associated with prolonged bed rest is avoided. Left untreated, a neck of femur fracture can be considered a terminal event. Historically, mortality associated with elderly hip fracture is 10% at one month, and 30% at one year. However, this has been improved in the UK with the introduction of multidisciplinary, orthogeriatric lead care and the National Hip Fracture Database and Best Practice Tariff. Pertinent anatomy Osteology - normal neck-shaft angle is 130 +/- 7 degrees, and 10 +/- 7 degrees of neck anteversion. Vascular supply - The predominant blood supply to the femoral head and neck is from the medial and lateral femoral circumflex arteries (branches of profunda femoris). These anastomose and pierce the joint capsule at the base of the neck, mainly posteriorly. There is a small vascular contribution from the artery of the ligament teres. Understanding the blood supply is fundamental to the decision making process in treating NOF fractures. Presentation and initial management Typically, patients present with pain in the hip/groin, a shortened, abducted, externally rotated leg (due to the unopposed pull of the muscles that act across the hip joint) and the inability to straight-leg-raise. With undisplaced fractures, signs are more subtle. High energy injuries should be treated in line with ATLS principles. All patients should be fluid resuscitated, have adequate pain relief (often with a fascio-iliiaca nerve block), and be optimised for surgery. In addition, elderly patients should be assessed by an orthogeriatrician. Imaging Anteroposterior and cross-table lateral plain radiographs are sufficient to diagnose the majority of NOF fractures. If the fracture extends below the level of the lesser trochanter, or there is any possibility of pathological fracture, full length femur views are essential to plan surgery. Where there is a high index of suspicion of fracture, but plain radiographs are inconclusive, gold standard investigation is MRI. However, if unavailable within 24 hours, or if the patient will not tolerate MRI, CT is appropriate. The majority of fractures can be seen with modern CT techniques, and so this is becoming first line in many hospitals. Classification There has been a move away from named classification systems towards descriptive classification systems. Two main types of NOF exist: Intra-capsular, and extra-capsular. Extra-capsular fractures are further divided into pertrochanteric or subtrochanteric (within 5cm distal to the lesser trochanter). All fractures are then described as undisplaced, minimally displaced, or displaced. Femoral neck and head blood supply disruption is common with intracapsular NOF fractures, and rare with extracapsular fractures. This fundamental principle underpins the practise of arthroplasty for intracapsular fractures, and fixation for extracapsular fractures. If you wish to use a named classification system, the most commonly used are below: Elderly intracapsular - Garden Classification Young intrasapsular - Pauvels Classification Intertrochanteric - Evans Subtrochanteric - Russell Taylor Treatment In general, NOF fractures are treated operatively except if the patient is deemed unlikely to survive an anaesthetic. Best Practice Tarif (BPT) dictates that surgery should happen within 36 hours, as delay of greater than 48 hours is associated with increased morbidity and mortality. Below are suggested algorithms for the treatment of NOF. * The priority with the young patient is to retain the femoral head if possible, even with a displaced intracapsular fracture. The risk of avascular necrosis and non-union (and therefore revision surgery) associated with internal fixation needs weighing up against the sequelae of total hip replacement in the young (wear, dislocation, revision). Discussion is necessary with the patient, on a case by case basis. ** Undisplaced fractures in the elderly can be treated with internal fixation, often with cannulated screws. This is appropriate for valgus impacted subcapital fractures which are inherently stable, to prevent secondary displacement. This does still carry the risk of AVN or non-union, and therefore a future revision. For this reason, many surgeons advocate arthroplasty as a single surgery. *** NICE guidance - patients who fulfil these criteria should be offered total hip replacement which conveys better function and prosthetic survivorship, compared with hemiarthroplasty, but at an increased risk of dislocation. * Intertrochanteric fractures vary greatly in their stability. If the trochanter (and therefore lateral wall), and medial calcar is in tact, then the fracture configuration bears stability. This can be treated with a DHS, as collapse of the fracture is predictable. Where either or both structures are involved in the fracture, stability becomes compromised and many surgeons will favour using an intramedullary device. This is an ongoing debate, and difficult to test in an exam setting. Post operative management Patients should be mobilised fully weight bearing where possible. Care is multidisciplinary in its delivery. Elderly patients should have orthogeriatrician assessment of comorbidity, and bone health with secondary prevention measures if appropriate. There should be early involvement of physiotherapy and occupational therapy services. For further guidance see sources listed below. NICE clinical guidance on hip fracture: https://www.nice.org.uk/guidance/cg124 Best Practice Tarif: www.nhfd.co.uk/20/hipfractureR.../Best%20Practice%20Tariff%20User%20Guide.pdf National Hip Fracture Database: www.nhfd.co.uk/

Answer 488

Sudden loss of urine output is most commonly due to a blocked catheter. However, if this is excluded (and is not included in the options) the most worrisome cause is arterial thrombosis. This will often be a delayed diagnosis and the rate of graft loss is high. Complications of renal transplantation A number of complications may occur following renal transplantation. A critical aspect of post operative care is evaluation of graft function. Post operatively, urine output is the most readily available, and easily measured, indicator of graft function. If an individual was relatively anuric pre-transplant and has a good urine output following surgery then this is more useful than it would be in someone who had a higher volume diuresis prior to transplantation. Recipients can be divided into three main groups following renal transplantation, with regard to their graft function: Immediate graft function; brisk diuresis and falling serum creatinine Slow graft function; modest urine output and slowly falling creatinine levels Delayed graft function; defined as need for dialysis post transplant Decreased urine output following surgery can be the result of hypovolvaemia or a blocked catheter (commonest causes). Other important causes include rejection, or a vascular complication. Vascular complications These may involve the donor vessels, those of the recipient or both. Renal artery thrombosis usually occurs early post transplant, but is uncommon with an incidence of less than 1%. It typically results in graft loss. It usually occurs as a result of a technical problem such a vessel torsion or sub intimal flaps. The usual presenting feature is a sudden cessation of urine output. When suspected, the occlusion is usually well demonstrated with duplex scanning. Ideally immediate surgical re-exploration should occur. Sadly, the graft has usually been lost by this stage and will require graft nephrectomy. Renal vein thrombosis is not as common as arterial graft thrombosis and the usual presenting features include discomfort at the graft site and swelling of the graft associated with loss of urine output. Again, duplex scanning is indicated. Unfortunately, this complication is also associated with a high incidence of graft loss. Over a longer time frame (typically months) some individuals will develop renal artery stenosis. These individuals will typically develop hypertension and over time graft function will decline as hypertensive nephropathy occurs. It is usually demonstrated by duplex scanning and is usually amenable to endovascular intervention. Urological complications Urinary tract complications manifesting as leakage or obstruction are common complications following renal transplantation and occur in up to 10% of patients. The main underlying cause is the relatively poor blood supply to the transplanted ureter. Patients typically present relatively early in the first 5 weeks following transplantation with pain and swelling at the graft site. Imaging with USS is often the initial test. Therapeutic options include surgical re-implantation of the ureter for large leaks and stent insertion and nephrostomy placement for smaller leaks. Lymphocele These do not generally occur until 2 weeks or longer after surgery. They are, however, relatively common and may be seen in up to 18% of patients. Symptoms usually occur as a result of mass effect with compression of adjacent structures. These include the vessels supplying both the graft, with deterioration in graft function, the ureter, with alteration in urine output and the recipients lower limb vessels, with development of leg swelling. Creation of a laparoscopic or open peritoneal window is a favored treatment. Rejection Four types of graft rejection are recognised; hyperacute, accelerated acute, acute and chronic. Type of rejection Key features Hyperacute Occurs within minutes of clamp release Due to pre formed antibodies Immediate loss of graft occurs Accelerated acute Occurs in first few days following surgery Involved both cellular and antibody mediated injury Pre-sensitisation of the donor is a common cause Acute Traditionally the most common type of rejection Seen days to weeks after surgery Predominantly a cell mediated process mediated by lymphocytes Organ biopsy demonstrates cellular infiltrates and graft cell apoptosis Chronic Increasingly common problem Typically; graft atrophy and atherosclerosis are seen. Fibrosis often occurs as a late event

Answer 489

In haemophilia A the APTT is prolonged and there is reduced levels of factor 8:C. The bleeding time and PT are normal. Cholestatic jaundice prevents the absorption of the fat soluble vitamin K. Massive transfusion (>10u blood or equivalent to the blood volume of a person) puts the patient at risk of thrombocytopaenia, factor 5 and 8 deficiency. Abnormal coagulation Cause Factors affected Heparin Prevents activation factors 2,9,10,11 Warfarin Affects synthesis of factors 2,7,9,10 DIC Factors 1,2,5,8,11 Liver disease Factors 1,2,5,7,9,10,11 Interpretation blood clotting test results Disorder APTT PT Bleeding time Haemophilia Increased Normal Normal von Willebrand's disease Increased Normal Increased Vitamin K deficiency Increased Increased Normal

Answer 490

Mnemonic for contents of cavernous sinus: O TOM CAT Occulomotor nerve (III) Trochlear nerve (IV) Ophthalmic nerve (V1) Maxillary nerve (V2) Carotid artery Abducent nerve (VI) T OTOM=lateral wall components CA= components within sinus The optic nerve lies above and outside the cavernous sinus.

Answer 491

The adductors are innervated by the obturator nerve. Adductor longus Origin Anterior body of pubis Insertion Middle third of linea aspera Action Adducts and flexes the thigh, medially rotate the hip Innervation Anterior division of obturator nerve (L2, L3, L4)

Answer 492

6 pillars of clinical governance: Clinical effectiveness Research and development Openness Risk management Education and training Clinical audit Audits should compare performance against known standards. Where a novel technique is being introduced standards are unlikely to exist, sample sizes cannot therefore be accurately calculated. This is an example of research, which is not an audit.

Answer 493

Although some acid lowering procedures increase the risk of gastric cancer the use of sucralfate does not, at the present time, seem to increase the risk. Gastric cancer Overview There are 700,000 new cases of gastric cancer worldwide each year. It is most common in Japan and less common in western countries. It is more common in men and incidence rises with increasing age. The exact cause of many sporadic cancer is not known, however, familial cases do occur in HNPCC families. In addition, smoking and smoked or preserved foods increase the risk. Japanese migrants retain their increased risk (decreased in subsequent generations). The distribution of the disease in western countries is changing towards a more proximal location (perhaps due to rising obesity). Pathology There is some evidence of support a stepwise progression of the disease through intestinal metaplasia progressing to atrophic gastritis and subsequent dysplasia, through to cancer. The favoured staging system is TNM. The risk of lymph node involvement is related to size and depth of invasion; early cancers confined to submucosa have a 20% incidence of lymph node metastasis. Tumours of the gastro-oesophageal junction are classified as below: Type 1 True oesophageal cancers and may be associated with Barrett's oesophagus. Type 2 Carcinoma of the cardia, arising from cardiac type epithelium or short segments with intestinal metaplasia at the oesophagogastric junction. Type 3 Sub cardial cancers that spread across the junction. Involve similar nodal stations to gastric cancer. Groups for close endoscopic monitoring Intestinal metaplasia of columnar type Atrophic gastritis Low to medium grade dysplasia Patients who have previously undergone resections for benign peptic ulcer disease (except highly selective vagotomy). Referral to endoscopy Patients of any age with dyspepsia and any of the following Patients without dyspepsia Worsening dyspepsia Chronic gastrointestinal bleeding Dysphagia Barretts oesophagus Dysphagia Unexplained abdominal pain or weight loss Intestinal metaplasia Weight loss Vomiting Dysplasia Iron deficiency anaemia Upper abdominal mass Atrophic gastritis Upper abdominal mass Jaundice Patient aged over 55 years with unexplained or persistent dyspepsia Upper GI endoscopy performed for dyspepsia. The addition of dye spraying (as shown in the bottom right) may facilitate identification of smaller tumours Staging CT scanning of the chest abdomen and pelvis is the routine first line staging investigation in most centres. Laparoscopy to identify occult peritoneal disease PET CT (particularly for junctional tumours) Treatment Proximally sited disease greater than 5-10cm from the OG junction may be treated by sub total gastrectomy Total gastrectomy if tumour is <5cm from OG junction For type 2 junctional tumours (extending into oesophagus) oesophagogastrectomy is usual Endoscopic sub mucosal resection may play a role in early gastric cancer confined to the mucosa and perhaps the sub mucosa (this is debated) Lymphadenectomy should be performed. A D2 lymphadenectomy is widely advocated by the Japanese, the survival advantages of extended lymphadenectomy have been debated. However, the overall recommendation is that a D2 nodal dissection be undertaken. Most patients will receive chemotherapy either pre or post operatively. Prognosis UK Data Disease extent Percentage 5 year survival All RO resections 54% Early gastric cancer 91% Stage 1 87% Stage 2 65% Stage 3 18% Operative procedure Total Gastrectomy , lymphadenectomy and Roux en Y anastomosis General anaesthesia Prophylactic intravenous antibiotics Incision: Rooftop. Perform a thorough laparotomy to identify any occult disease. Mobilise the left lobe of the liver off the diaphragm and place a large pack over it. Insert a large self retaining retractor e.g. omnitract or Balfour (take time with this, the set up should be perfect). Pack the small bowel away. Begin by mobilising the omentum off the transverse colon. Proceed to detach the short gastric vessels. Mobilise the pylorus and divide it at least 2cm distally using a linear cutter stapling device. Continue the dissection into the lesser sac taking the lesser omentum and left gastric artery flush at its origin. The lymph nodes should be removed en bloc with the specimen where possible. Place 2 stay sutures either side of the distal oesophagus. Ask the anaesthetist to pull back on the nasogastric tube. Divide the distal oesophagus and remove the stomach. The oesphago jejunal anastomosis should be constructed. Identify the DJ flexure and bring a loop of jejunum up to the oesophagus (to check it will reach). Divide the jejunum at this point. Bring the divided jejunum either retrocolic or antecolic to the oesophagus. Anastamose the oesophagus to the jejunum, using either interrupted 3/0 vicryl or a stapling device. Then create the remainder of the Roux en Y reconstruction distally. Place a jejunostomy feeding tube. Wash out the abdomen and insert drains (usually the anastomosis and duodenal stump). Help the anaesthetist insert the nasogastric tube (carefully!) Close the abdomen and skin. Enteral feeding may commence on the first post-operative day. However, most surgeons will leave patients on free NG drainage for several days and keep them nil by mouth.

Answer 494

Urinary metanephrine measurements are not completely specific but constitute first line assessment and more accurate than urinary VMA measurements. Stimulation tests of any sort are not justified in first line assessments. Phaeochromocytoma and adrenal lesions Phaeochromocytoma Neuroendocrine tumour of the chromaffin cells of the adrenal medulla. Hypertension and hyperglycaemia are often found. 10% of cases are bilateral. 10% occur in children. 11% are malignant (higher when tumour is located outside the adrenal). 10% will not be hypertensive. Familial cases are usually linked to the Multiple endocrine neoplasia syndromes (considered under its own heading). Most tumours are unilateral (often right sided) and smaller than 10cm. Diagnosis Urine and plasma metanephrine levels. CT and MRI scanning are both used to localise the lesion. Treatment Patients require medical therapy first. An irreversible alpha adrenoreceptor blocker should be given, although minority may prefer reversible blockade(1). Labetolol may be co-administered for cardiac chronotropic control. Isolated beta blockade should not be considered as it will lead to unopposed alpha activity. These patients are often volume depleted and will often require moderate volumes of intra venous normal saline perioperatively. Once medically optimised the phaeochromocytoma should be removed. Most adrenalectomies can now be performed using a laparoscopic approach(2). The adrenals are highly vascular structures and removal can be complicated by catastrophic haemorrhage in the hands of the inexperienced. This is particularly true of right sided resections where the IVC is perilously close. Should the IVC be damaged a laparotomy will be necessary and the defect enclosed within a Satinsky style vascular clamp and the defect closed with prolene sutures. Attempting to interfere with the IVC using any instruments other than vascular clamps will result in vessel trauma and make a bad situation much worse. Incidental adrenal lesions Adrenal lesions may be identified on CT scanning performed for other reasons(3). Factors suggesting benign disease on CT include(4): Size less than 3cm Homogeneous texture Lipid rich tissue Thin wall to lesion All patients with incidental lesions should be managed jointly with an endocrinologist and full work up as described above. Patients with functioning lesions or those with adverse radiological features (Particularly size >3cm) should proceed to surgery.

Answer 495

Cerebral perfusion pressure= Mean arterial pressure - intra cranial pressure The mean arterial pressure can be calculated as: MAP= Diastolic pressure+ 0.333(Systolic pressure- Diastolic pressure) In this situation the MAP = 93. The ICP is subtracted from this value; 93 - 17 = 76 Cerebral perfusion pressure The cerebral perfusion pressure (CPP) is defined as being the net pressure gradient causing blood flow to the brain. The CPP is tightly autoregulated to maximise cerebral perfusion. A sharp rise in CPP may result in a rising ICP, a fall in CPP may result in cerebral ischaemia. It may be calculated by the following equation: CPP= Mean arterial pressure - Intra cranial pressure Following trauma, the CPP has to be carefully controlled and the may require invasive monitoring of the ICP and MAP.

Answer 496

The annular ligament connects the radial head to the radial notch of the ulna. Radius The radius is one of the two long forearm bones that extends from the lateral side of the elbow to the thumb side of the wrist. It has two expanded ends, of which the distal end is the larger. Key points relating to its topography and relations are outlined below; Upper end Articular cartilage- covers medial > lateral side Articulates with radial notch of the ulna by the annular ligament Muscle attachment- biceps brachii at the tuberosity Shaft Muscle attachment Upper third of the body Supinator Flexor digitorum superficialis Flexor pollicis longus Middle third of the body Pronator teres Lower quarter of the body Pronator quadratus Tendon of supinator longus Lower end Quadrilateral Anterior surface- capsule of wrist joint Medial surface- head of ulna Lateral surface- ends in the styloid process Posterior surface: 3 grooves containing: 1. Tendons of extensor carpi radialis longus and brevis 2. Tendon of extensor pollicis longus 3. Tendon of extensor indicis

Answer 497

The tricuspid valve is generally referred to being best auscultated adjacent to the sternum. The plane of projected sound from the mitral area is best heard in the region of the cardiac apex. Heart sounds Sites of auscultation Valve Site Pulmonary valve Left second intercostal space, at the upper sternal border Aortic valve Right second intercostal space, at the upper sternal border Mitral valve Left fifth intercostal space, just medial to mid clavicular line Tricuspid valve Left fourth intercostal space, at the lower left sternal border

Answer 498

The retromandibular vein lies slightly more deeply than the facial nerve in the parotid gland. It is formed from the maxillary and superficial temporal vein. Retromandibular vein Formed by a union of the maxillary vein and superficial temporal vein It descends through the parotid gland and bifurcates within it The anterior division passes forwards to join the facial vein, the posterior division is one of the tributaries of the external jugular vein

Answer 499

Lesions at the optic chiasm classically produce a bitemporal hemianopia, however note lesions that spread up from below ie pituitary tumours, the defect is worse in the upper fields and if a lesion spreads down from above ie craniopharyngiomas, the visual defect is worse in the lower quadrants. Therefore this patient is likely to have a lower bitemporal hemianopia. Visual field defects left homonymous hemianopia means visual field defect to the left, i.e. Lesion of right optic tract homonymous quadrantanopias: PITS (Parietal-Inferior, Temporal-Superior) incongruous defects = optic tract lesion; congruous defects = optic radiation lesion or occipital cortex Homonymous hemianopia Incongruous defects: lesion of optic tract Congruous defects: lesion of optic radiation or occipital cortex Macula sparing: lesion of occipital cortex Homonymous quadrantanopias Superior: lesion of temporal lobe Inferior: lesion of parietal lobe Mnemonic = PITS (Parietal-Inferior, Temporal-Superior) Bitemporal hemianopia Lesion of optic chiasm Upper quadrant defect > lower quadrant defect = inferior chiasmal compression, commonly a pituitary tumour Lower quadrant defect > upper quadrant defect = superior chiasmal compression, commonly a craniopharyngioma

Answer 500

Eponymous fractures Colles' fracture (dinner fork deformity) Fall onto extended outstretched hand Classical Colles' fractures have the following 3 features: 1. Transverse fracture of the radius 2. 1 inch proximal to the radio-carpal joint 3. Dorsal displacement and angulation Smith's fracture (reverse Colles' fracture) Volar angulation of distal radius fragment (Garden spade deformity) Caused by falling backwards onto the palm of an outstretched hand or falling with wrists flexed Bennett's fracture Intra-articular fracture of the first carpometacarpal joint Impact on flexed metacarpal, caused by fist fights X-ray: triangular fragment at ulnar base of metacarpal Monteggia's fracture Dislocation of the proximal radioulnar joint in association with an ulna fracture Fall on outstretched hand with forced pronation Needs prompt diagnosis to avoid disability Galeazzi fracture Radial shaft fracture with associated dislocation of the distal radioulnar joint Direct blow Pott's fracture Bimalleolar ankle fracture Forced foot eversion Barton's fracture Distal radius fracture (Colles'/Smith's) with associated radiocarpal dislocation Fall onto extended and pronated wrist Involvement of the joint is a defining feature Holstein Lewis Fracture A HolsteinLewis fracture is a fracture of the distal third of the humerus resulting in entrapment of the radial nerve. The radial nerve is one of the major nerves of the upper limb. It innervates all of the muscles in the extensor compartments of the arm. Conservative treatment includes reduction and use of a functional brace Vascular injury may require open surgery

Answer 501

Water absorption in the gastrointestinal tract predominantly occurs in the small bowel (jejunum and ileum). The colon is an important site of water absorption, however, its overall contribution is relatively small. The importance of the colonic component to water absorption may increase following extensive small bowel resections. Water absorption During a 24 hours period the average person will ingest up to 2000ml of liquid orally. In addition a further 8000ml of fluid will enter the small bowel as gastrointestinal secretions. Intestinal water absorption is a passive process and is related to solute load. In the jejunum the active absorption of glucose and amino acids will create a concentration gradient that water will flow across. In the ileum most water is absorbed by a process of facilitated diffusion (with sodium). Approximately 150ml of water enters the colon daily, most is absorbed, the colon can adapt to, and increase this amount following resection.

Answer 502

Mitral stenosis is the commonest cause of cardiac abnormality occurring in pregnant women. Mitral stenosis is becoming less common in the UK population, however should be considered in women from countries where there is a higher incidence of rheumatic heart disease. Mitral stenosis causes a mid diastolic murmur which may be difficult to auscultate unless the patient is placed into the left lateral position. These patients are at risk of atrial fibrillation (up to 40%), which can also contribute to rapid decompensation such as pulmonary oedema (hence cxr 'whiteout' of lungs). Physiological changes in pregnancy may cause an otherwise asymptomatic patient to suddenly deteriorate. Balloon valvuloplasty is the treatment of choice.

Answer 503

This patient may well develop raised ICP over the next few days and intracranial pressure monitoring will help with management. Head injury management- NICE Guidelines Summary of guidelines All patients should be assessed within 15 minutes on arrival to A&E Document all 3 components of the GCS If GCS <8 or = to 8, consider stabilising the airway Full spine immobilisation until assessment if: - GCS < 15 - neck pain/tenderness - paraesthesia extremities - focal neurological deficit - suspected c-spine injury If a c-spine injury is suspected a 3 view c-spine x-ray is indicated. CT c-spine is preferred if: - Intubated - GCS <13 - Normal x-ray but continued concerns regarding c-spine injury - Any focal neurology - A CT head scan is being performed - Initial plain films are abnormal Immediate CT head (within 1 hour) if: GCS < 12 on admission GCS < 15 2 hours after admission Suspected open or depressed skull fracture Suspected skull base fracture (panda eyes, Battle's sign, CSF from nose/ear, bleeding ear) Focal neurology Vomiting > 1 episode Post traumatic seizure Contact neurosurgeon if: Persistent GCS < 8 or = 8 Unexplained confusion > 4h Reduced GCS after admission Progressive neurological signs Incomplete recovery post seizure Penetrating injury Cerebrospinal fluid leak Observations 1/2 hourly GCS until 15 In the latest guidance, there is a move to considering CT in those on anticoagulants rather than mandating it. Reference 1. NICE Guidance NG 232 (Published 2023). 2. Hodgkinson S et al. Early management of head injury: summary of NICE guidance. BMJ 2014 (348):34-37.

Answer 504

The diaphragm is the major muscle involved in this process and it is for this reason that diminished activity following major abdominal surgery (note surgery type not specified here) can result in atelectasis. Alveolar ventilation - Minute ventilation is the total volume of gas ventilated per minute. MV (ml/min)= tidal volume x Respiratory rate (resps/min). Dead space ventilation describes the volume of gas not involved in exchange in the blood. There are 2 types: 1. Anatomical dead space: 150mls Volume of gas in the respiratory tree not involved in gaseous exchange: mouth, pharynx, trachea, bronchi up to terminal bronchioles Measured by Fowlers method Increased by: Standing, increased size of person, increased lung volume and drugs causing bronchodilatation e.g. Adrenaline 2. Physiological dead space: normal 150 mls, increases in ventilation/perfusion mismatch e.g. PE, COPD, hypotension Volume of gas in the alveoli and anatomical dead space not involved in gaseous exchange. Alveolar ventilation is the volume of fresh air entering the alveoli per minute. Alveolar ventilation = minute ventilation - Dead space volume

Answer 505

Obstructing sigmoid cancers can be resected or stented. If stented, then the patient may need definitive surgery later. If resected, then a resection and end colostomy (Hartmann's ) procedure is usually undertaken because of the risks of anastomotic leak in the setting of anastomosing obstructed colon to rectum. Large bowel obstruction Colonic obstruction remains a common surgical problem. It is most commonly due to malignancy (60%) and diverticular disease (20%). Volvulus affecting the colon accounts for 5% of cases. Acute colonic pseudo-obstruction remains a potential differential diagnosis in all cases. Intussusception affecting the colon (most often due to tumours in the adult population) remains a rare but recognised cause. The typical patient will present with gradual onset of progressive abdominal distension, colicky abdominal pain and either obstipation or absolute constipation. On examination abdominal distension is present, the presence of caecal tenderness (assuming no overt evidence of peritonitis) is a useful sign to elicit. A digital rectal examination and rigid sigmoidoscopy should be performed. A plain abdominal x-ray is the usual first line test and; the caecal diameter and ileocaecal valve competency should be assessed on this film. Imaging modalities Debate long surrounds the use of CT versus gastrograffin enemas. The latter investigation has always been the traditional method of determining whether a structural lesion is indeed present. However, in the UK the use of this technique has declined and in most units a CT scan will be offered as the first line investigation by the majority of radiologists (and is advocated by the ACPGBI). In most cases this will provide sufficient detail to allow operative planning, and since malignancy accounts for most presentations may also stage the disease. In the event that the radiologist cannot provide a clear statement of lesion site, the surgeon should have no hesitation in requesting a contrast enema. Surgical options The decision as to when to operate or not is determined firstly by the patients physiological status. Unstable patients require resuscitation prior to surgery and admission to a critical care unit for invasive monitoring and potential inotropic support may be needed. In patients who are otherwise stable the decision then rests on the radiological and clinical findings. As a general rule the old adage that the sun should not rise and set on unrelieved large bowel obstruction still holds true. A caecal diameter of 12cm or more in the presence of complete obstruction with a competent ileocaecal valve and caecal tenderness is a sign of impending perforation and a relative indication for prompt surgery. Right sided and transverse lesions Right sided lesions producing large bowel obstruction should generally be treated by right hemicolectomy or its extended variant if the lesion lies in the distal transverse colon or splenic flexure. In these cases an ileocolic anastomosis may be easily constructed and even in the emergency setting has a low risk of anastomotic leak. Left sided lesions The options here lie between sub total colectomy and anastomosis, left hemicolectomy with on table lavage and primary anastomosis, left hemicolectomy and end colostomy formation and finally colonic stent insertion. The usefulness of colonic stents was the subject of a Cochrane review in 2011. The authors concluded that on the basis of the data that they reviewed, there was no benefit from the use of colonic stents over conventional surgical resection with a tendency to better outcomes seen in the surgical group (1). A more recently conducted meta analysis met with the same conclusion (2). However, the recently concluded CREST trial has suggested that self expanding metallic stents can improve outcomes and avoids a stoma. Rectosigmoid lesions Lesions below the peritoneal reflection that are causing obstruction should generally be treated with a loop colostomy. Primary resection of unstaged rectal cancer would most likely carry a high CRM positivity rate and cannot be condoned. Where the lesion occupies the distal sigmoid colon the usual practice would be to perform a high anterior resection. The decision surrounding restoration of intestinal continuity would lie with the operating surgeon. References 1. Sagar J. Colorectal stents for the management of malignant colonic obstructions. Cochrane Database of Systematic Reviews 2011, Issue 11. Art. No.: CD007378. DOI: 10.1002/14651858.CD007378.pub2. 2. Cirrochi et al Safety and efficacy of endoscopic colonic stenting as a bridge to surgery in the management of intestinal obstruction due to left colon and rectal cancer: A systematic review and meta-analysis. Surg Oncol. 2013 Mar;22(1):14-21.

Answer 506

This is an unstable ankle injury that is likely to require surgical fixation. The immediate management of a displaced ankle fracture is to reduce the fracture to prevent soft tissues compromise and help reduce swelling. This can be performed before an x-ray is obtained if performing the x-ray will significantly delay reduction. Ankle injuries An ankle fracture relates to a fracture around the tibio-talar joint. It generally refers to a fracture involving the lateral, and/or medial and/or posterior malleolus. Pilon and Tillaux fractures are also considered to be ankle fractures, but are not covered here. Ankle fractures are common. They effect men and women in equal numbers, but men have a higher rate as young adults (sports and contact injuries), and women a higher rate post-menopausal (fragility type fracture). Osseous anatomy The ankle (or mortise) joint consists of the distal tibia (tibial plafond and posterior malleolus), the distal fibula (lateral malleolus), and the talus. The main movement at the ankle joint is plantar and dorsiflexion. Ligamentous anatomy Medial side: Deltoid ligament. This is divided into superficial and deep portions. It is the primary restraint to valgus tilting of the talus. Lateral side: Lateral ligament complex consisting from anterior to posterior of the anterior talofibular ligament (ATFL), calcaneofibular ligament (CFL), and the posterior talofibular ligament (PTFL). Together they resist valgus stress to the ankle, and are a restraint to anterior translation of the talus within the mortise joint. Syndesmosis: The syndesmosis is a ligament complex between the distal tibia and fibula, holding the two bones together. It is fundamental to the integrity of the ankle joint, and its disruption leads to instability. It consists of (from anterior to posterior) the anterior-inferior tibiofibular ligament (AITFL), the transverse tibiofibular ligament (TTFL), the interosseous membrane, and the posterior-inferior tibiofibular ligament (PITFL). Presentation and initial management Patients will present following a traumatic event with a painful, swollen ankle, and reluctance/inability to weight bear. The Ottawa rules can be applied to differentiate between an ankle fracture and sprain, but can be unreliable. In high energy injuries, management should follow ATLS principles to identify more significant injuries first. Neurovascular status of the foot should be documented, and open injuries should be excluded. If an open injury is identified, it should be managed in line with BOAST 4 principles1. If an obvious deformity exists, it should be reduced as soon as possible with appropriate analgesia or conscious sedation. Radiographs of clearly deformed or dislocated joints are not necessary, and removing the pressure on the surrounding soft tissues from the underlying bony deformity is the priority. If the fracture pattern is not clinically obvious then plain radiographs are appropriate and will guide the subsequent manipulation during plaster-of-paris below knee backslab application. Imaging AP, lateral and mortise views (20 degrees internal rotation) are essential to evaluate fracture displacement and syndesmotic injury. Decreased tibiofibular overlap, medial joint clear space and lateral talar shift all indicate a syndesmotic injury. (In subtle cases of shift, imaging the uninjured ankle can be helpful as a proportion of the population have little or no tibiotalar overlap-reference 2.) Where there is suspicion of syndesmosis involvement in the absence of radiographic evidence, stress radiographs can be diagnostic. Complex fracture patterns (and increasingly posterior malleolar fractures) are best defined using CT. Classification The most commonly used classifications are Lauge-Hansen and Danis-Weber. Lauge-Hansen Comprises two parts: first part is the foot position, and the second part is the force applied. Useful for understanding the forces involved and therefore predict the ligamentous or bony injury. Results in four injury patterns: Supination - Adduction (SA) - 10-20% Supination - External rotation (SER) - 40-75% Pronation - Abduction (PA) - 5-20% Pronation - External rotation (PER) - 5-20% Not often used in clinical practice but good for understanding the principles of ankle fracture. Danis-Weber Commonly used. Based on the level of the fibula fracture in relation to the syndesmosis. The more proximal, the greater the risk of syndesmotic injury and therefore fracture instability. A - fracture below the level of the syndesmosis B - fracture at the level of the syndesmosis / level of the tibial plafond C - fracture above the level of the syndesmosis. This includes Maisonneuve fractures (proximal fibula fracture), which can be associated with ankle instability. Beware the high fibula fracture - it may be an ankle fracture! The Weber classification is based purely on the the lateral side. All injuries can include a medial or posterior bony or ligamentous injury which also dictates fracture stability (bimalleolar and trimalleolar fractures are more unstable). Treatment When deciding upon treatment for an ankle fracture, one must consider both the fracture and the patient. Diabetic patients and smokers are at greater risk of post-operative complication, especially wound problems and infection. Likewise, the long term outcome of post-traumatic arthritis from a malunited ankle fracture is extremely important for a young patient, but not as relevant in the elderly. Therefore, normal surgical decision processes apply as with all fractures. Defining stability of an ankle fracture underpins the treatment decision. Weber A - Unimalleolar Weber A Weber fractures by definition are stable and therefore can be mobilised fully weight bearing in an ankle boot. Weber C - Fractures tend to include syndesmotic disruption and are usually bimalleolar (either bony or ligamentous). They are therefore unstable and usually require operative fixation. In addition to the fracture fixation, the syndesmosis usually requires reconstruction/augmentation with screws to restore the joint integrity and function. Weber B - B fractures vary greatly. They can be part of a trimalleolar injury and therefore extremely unstable, requiring fixation. Alternatively, a uni-malleolar Weber B fracture can be a stable injury, and therefore mobilised immediately in an ankle boot. Defining the stability can be challenging, and often involves stress radiographs, or a trial of mobilisation and repeat radiographs. However, treating undisplaced ankle fractures in a below knee plaster, non-weight bearing for six weeks is still widely practised, and a safe approach. When operative fixation is appropriate, it is usually via open reduction and internal fixation using plates and screws. It must be carried out when soft tissue swelling has settled in order to minimise the risk of wound problems. This can often take a week to settle. The use of fibula nails is expanding, but is not yet mainstream. Ankle fractures can also be treated with external fixation, or with a hind foot nail in patients who need fixation but where soft tissue or bone quality is poor. Post operative management Ankle fractures generally take 6 weeks to unite enough to prevent secondary displacement. This is therefore an appropriate time period to keep a cast on in a conservatively managed patient. Weight bearing post-operatively depends on the quality of the fixation and bone quality, and preference varies between surgeons, ranging from aggressive early mobilisation to a period of non-weight bearing. Return to activities takes approximately three months, and often requires assistance of a physiotherapist to improve range-of-movement and muscle strengthening. References 1. http://www.boa.ac.uk/publications/boa-standards-trauma-boasts/ 2. Shah AS, Kadakia AR, Tan GJ, Karadsheh MS, Wolter TD, Sabb B. Radiographic evaluation of the normal distal tibiofibular syndesmosis. Foot Ankle Int. 2012;33(10):870-6

Answer 507

SCC of the kidney usually arises in an area of chronic inflammation such as a staghorn calculus. They are rare. Renal tumours Renal cell carcinoma Renal cell carcinoma is an adenocarcinoma of the renal cortex and is believed to arise from the proximal convoluted tubule. They are usually solid lesions, up to 20% may be multifocal, 20% may be calcified and 20% may have either a cystic component or be wholly cystic. They are often circumscribed by a pseudocapsule of compressed normal renal tissue. Spread may occur either by direct extension into the adrenal gland, renal vein or surrounding fascia. More distant disease usually occurs via the haematogenous route to lung, bone or brain. Renal cell carcinoma comprise up to 85% of all renal malignancies. Males are more commonly affected than females and sporadic tumours typically affect patients in their sixth decade. Patients may present with a variety of symptoms including; haematuria (50%), loin pain (40%), mass (30%) and up to 25% may have symptoms of metastasis.Less than 10% have the classic triad of haematuria, pain and mass. Investigation Many cases will present as haematuria and be discovered during diagnostic work up. Benign renal tumours are rare, so renal masses should be investigated with multislice CT scanning. Most tumours are also characterised with an arterial phase CT, particularly if they may be suitable for partial nephrectomy. CT scanning of the chest and abdomen to detect distant disease should also be undertaken. Routine bone scanning is not indicated in the absence of symptoms. Biopsy should not be performed when a nephrectomy is planned but is mandatory before any ablative therapies are undertaken. Assessment of the functioning of the contra lateral kidney. Management T1 lesions may be managed by partial nephrectomy and this gives equivalent oncological results to total radical nephrectomy. Partial nephrectomy may also be performed when there is inadequate reserve in the remaining kidney. Ablative techniques may also be considered for small T1 lesions in unfit patients. In general, outcomes are less favorable than with surgical resection. For T2 lesions and above a radical nephrectomy is standard practice and this may be performed via a laparoscopic or open approach. Preoperative embolisation is not indicated nor is resection of uninvolved adrenal glands. During surgery early venous control is mandatory to avoid shedding of tumour cells into the circulation. Patients with completely resected disease do not benefit from adjuvant therapy with either chemotherapy or biological agents. These should not be administered outside the setting of clinical trials. Patients with transitional cell cancer will require a nephroureterectomy with disconnection of the ureter at the bladder. References Capitanio U, Montorsi F. Renal cancer. Lancet. 2016 Feb 27;387(10021):894-906. Capitanio U et al. Epidemiology of Renal Cell Carcinoma. Eur Urol. 2019 Jan;75(1):74-84.

Answer 508

Whilst the base of the ulcer may be lined by granulation tissue, this is seldom exophytic. One of the concerns would be that this represents a malignant transformation. Chronic venous insufficiency and varicose veins Wide spectrum of disease ranging from minor cosmetic problem through to ulceration and disability. It is commoner in women than men and is worse during pregnancy. Varicose veins are best considered as being a saccular dilation of veins (WHO). Chronic venous insufficiency is a series of tissue changes which occur in relation to pooling of blood in the extremities with associated venous hypertension occurring as a result of incompetent deep vein valves. The veins of the lower limb consist of an interconnected network of superficial and deep venous systems. Varices occur because of localised weakness in the vein wall resulting in dilatation and reflux of blood due to non union of valve cusps. Histologically, the typical changes include fibrous scar tissue dividing smooth muscle within media in the vessel wall. Tissue damage in chronic venous insufficiency occurs because of perivascular cytokine leakage resulting in localised tissue damage coupled with impaired lymphatic flow. Diagnosis Typical symptoms of varicose veins include: Cosmetic appearance Aching Ankle swelling that worsens as the day progresses Episodic thrombophlebitis Bleeding Itching Symptoms of chronic venous insufficiency include: Dependant leg pain Prominent leg swelling Oedema extending beyond the ankle Venous stasis ulcers The typical venous stasis ulcer is: Located above the medial malleolus Indolent appearance with basal granulation tissue Variable degree of scarring Non ischaemic edges Haemosiderin deposition in the gaiter area (and also lipodermatosclerosis). Differential diagnosis Lower limb arterial disease Marjolins ulcer Claudication Spinal stenosis Swelling due to medical causes e.g. CCF. Exclusion of these differentials is by means of physical examination and ankle brachial pressure index measurement. Examination Assess for dilated short saphenous vein (popliteal fossa) and palpate for saphena varix medial to the femoral artery Brodie-Trendelenburg test: to assess level of incompetence Perthes' walking test: assess if deep venous system competent Investigation Doppler exam: if incompetent a biphasic signal due to retrograde flow is detected Duplex scanning: to ensure patent deep venous system (do if DVT or trauma) All patients should have a Doppler assessment to assess for venous reflux and should be classified as having uncomplicated varicose veins or varicose veins with associated chronic venous insufficiency. In the history establishing a previous thrombotic event (DVT/ lower limb fracture) is important and patients with such a history and all who have evidence of chronic venous insufficiency should have a duplex scan performed. Owing to litigation patients with saphenopopliteal incompetence should have a duplex scan performed and the site marked by scan on the day of surgery. Treatment Indications for surgery: Cosmetic: majority Lipodermatosclerosis causing venous ulceration Recurrent superficial thrombophlebitis Bleeding from ruptured varix Condition Therapy Minor varicose veins - no complications Reassure/ cosmetic therapy Symptomatic uncomplicated varicose veins In those without deep venous insufficiency options include; endothermal ablation, foam sclerotherapy, saphenofemoral / popliteal disconnection, stripping and avulsions, compression stockings Varicose veins with skin changes Therapy as above (if compression minimum is formal class I stockings) Chronic venous insufficiency or ulcers Class 2-3 compression stockings (ensure no arterial disease). Application of formal compression stockings (usually class II/III). In patients who have suffered ulceration, compression stockings should be worn long term. Where ulceration is present and established saphenofemoral reflux exists this should be addressed surgically for durable relief of symptoms, either at the outset or following ulcer healing. Injection sclerotherapy (5% Ethanolamine oleate), foam is increasingly popular, though transient blindness has been reported. Endo venous laser therapy is another minimally invasive option Sapheno-femoral or sapheno-popliteal ligation, in the case of the LSV; stripping and multiple phlebectomies Current best practice guidance In the United Kingdom the National Institute of Clinical Excellence guidance on varicose veins suggests that for patients with symptomatic varicose veins the first line procedure of choice should be endothermal ablation (see reference for more information). Where this is unavailable or unsuitable then foam sclerotherapy should be the second line option. Surgery is currently the third line treatment option. Trendelenburg procedure (sapheno-femoral junction ligation) Head tilt 15 degrees and legs abducted Oblique incision 1cm medial from artery Tributaries ligated (Superficial circumflex iliac vein, Superficial inferior epigastric vein, Superficial and deep external pudendal vein) SF junction double ligated Saphenous vein stripped to level of knee/upper calf. NB increased risk of saphenous neuralgia if stripped more distally References Marsden G et al. Diagnosis of management of varicose veins in the the legs: summary of NICE guidance. BMJ 2013 (347): 30-31.

Answer 509

The posterior compartment of the lower leg has both superficial and deep posterior layers, together with the anterior and lateral compartments this allows for four compartments. Decompression of the deep posterior compartment during fasciotomy may be overlooked with significant sequelae. Fascial compartments of the leg Compartments of the thigh Formed by septae passing from the femur to the fascia lata. Compartment Nerve Muscles Blood supply Anterior compartment Femoral Iliacus Tensor fasciae latae Sartorius Quadriceps femoris Femoral artery Medial compartment Obturator Adductor longus/magnus/brevis Gracilis Obturator externus Profunda femoris artery and obturator artery Posterior compartment (2 layers) Sciatic Semimembranosus Semitendinosus Biceps femoris Branches of Profunda femoris artery Compartments of the lower leg Separated by the interosseous membrane (anterior and posterior compartments), anterior fascial septum (separate anterior and lateral compartments) and posterior fascial septum (separate lateral and posterior compartments) Compartment Nerve Muscles Blood supply Anterior compartment Deep peroneal nerve Tibialis anterior Extensor digitorum longus Extensor hallucis longus Peroneus tertius Anterior tibial artery Posterior compartment Tibial Muscles: deep and superficial compartments (separated by deep transverse fascia) Deep: Flexor hallucis longus, Flexor digitalis longus, Tibialis posterior, Popliteus Superficial: Gastrocnemius, Soleus, Plantaris Posterior tibial Lateral compartment Superficial peroneal Peroneus longus/brevis Peroneal artery

Answer 510

Early plain x-ray changes in Perthes Disease: Widening of the joint space. Sub chondral linear lucency. This is a typical presentation for Perthes disease. X-ray may show flattening of the femoral head or fragmentation in more advanced cases. Paediatric orthopaedics Diagnosis Mode of presentation Treatment Radiology Developmental dysplasia of the hip Usually diagnosed in infancy by screening tests. May be bilateral, when disease is unilateral there may be leg length inequality. As disease progresses child may limp and then early onset arthritis. More common in extended breech babies. Splints and harnesses or traction. In later years osteotomy and hip realignment procedures may be needed. In arthritis a joint replacement may be needed. However, this is best deferred if possible as it will almost certainly require revision Initially no obvious change on plain films and USS gives best resolution until 3 months of age. On plain films Shentons line should form a smooth arc Perthes Disease Hip pain (may be referred to the knee) usually occurring between 5 and 12 years of age. Bilateral disease in 20%. Remove pressure from joint to allow normal development. Physiotherapy. Usually self-limiting if diagnosed and treated promptly. X-rays will show flattened femoral head. Eventually in untreated cases the femoral head will fragment. Slipped upper femoral epiphysis Typically seen in obese male adolescents. Pain is often referred to the knee. Limitation to internal rotation is usually seen. Knee pain is usually present 2 months prior to hip slipping. Bilateral in 20%. Bed rest and non-weight bearing. Aim to avoid avascular necrosis. If severe slippage or risk of it occurring then percutaneous pinning of the hip may be required. X-rays will show the femoral head displaced and falling inferolaterally (like a melting ice cream cone) The Southwick angle gives indication of disease severity

Answer 511

In the autonomic nervous system, noradrenaline is the commonly used neurotransmitter. However, in the adrenal medulla, Acetylcholine is released to stimulate adrenaline release. Adrenal physiology Adrenal medulla The chromaffin cells of the adrenal medulla secrete the catecholamines noradrenaline and adrenaline. The medulla is innervated by the splanchnic nerves; the preganglionic sympathetic fibres secrete acetylcholine causing the chromaffin cells to secrete their contents by exocytosis. Phaeochromocytomas are derived from these cells and will secrete both adrenaline and nor adrenaline. Adrenal cortex Three histologically distinct zones are recognised: Zone Location Hormone Secreted Zona glomerulosa Outer zone Aldosterone Zona fasiculata Middle zone Glucocorticoids Zona reticularis Inner zone Androgens The glucocorticoids and aldosterone are mostly bound to plasma proteins in the circulation. Glucocorticoids are inactivated and excreted by the liver.

Answer 512

Head injury with anticoagulants= CT head Head injury management- NICE Guidelines Summary of guidelines All patients should be assessed within 15 minutes on arrival to A&E Document all 3 components of the GCS If GCS <8 or = to 8, consider stabilising the airway Full spine immobilisation until assessment if: - GCS < 15 - neck pain/tenderness - paraesthesia extremities - focal neurological deficit - suspected c-spine injury If a c-spine injury is suspected a 3 view c-spine x-ray is indicated. CT c-spine is preferred if: - Intubated - GCS <13 - Normal x-ray but continued concerns regarding c-spine injury - Any focal neurology - A CT head scan is being performed - Initial plain films are abnormal Immediate CT head (within 1 hour) if: GCS < 12 on admission GCS < 15 2 hours after admission Suspected open or depressed skull fracture Suspected skull base fracture (panda eyes, Battle's sign, CSF from nose/ear, bleeding ear) Focal neurology Vomiting > 1 episode Post traumatic seizure Contact neurosurgeon if: Persistent GCS < 8 or = 8 Unexplained confusion > 4h Reduced GCS after admission Progressive neurological signs Incomplete recovery post seizure Penetrating injury Cerebrospinal fluid leak Observations 1/2 hourly GCS until 15 In the latest guidance, there is a move to considering CT in those on anticoagulants rather than mandating it. Reference 1. NICE Guidance NG 232 (Published 2023). 2. Hodgkinson S et al. Early management of head injury: summary of NICE guidance. BMJ 2014 (348):34-37.

Answer 513

The sural nerve is related to the short saphenous vein. The saphenous nerve is related to the long saphenous vein below the knee and for this reason full length stripping of the vein is no longer advocated. Saphenous vein Long saphenous vein This vein may be harvested for bypass surgery, or removed as treatment for varicose veins with saphenofemoral junction incompetence. Originates at the 1st digit where the dorsal vein merges with the dorsal venous arch of the foot Passes anterior to the medial malleolus and runs up the medial side of the leg At the knee, it runs over the posterior border of the medial epicondyle of the femur bone Then passes laterally to lie on the anterior surface of the thigh before entering an opening in the fascia lata called the saphenous opening It joins with the femoral vein in the region of the femoral triangle at the saphenofemoral junction Tributaries Medial marginal Superficial epigastric Superficial iliac circumflex Superficial external pudendal veins Short saphenous vein Originates at the 5th digit where the dorsal vein merges with the dorsal venous arch of the foot, which attaches to the great saphenous vein. It passes around the lateral aspect of the foot (inferior and posterior to the lateral malleolus) and runs along the posterior aspect of the leg (with the sural nerve) Passes between the heads of the gastrocnemius muscle, and drains into the popliteal vein, approximately at or above the level of the knee joint.

Answer 514

Lynch syndrome is inherited in an autosomal dominant fashion. It is characterised by microsatellite instability in the DNA mismatch repair genes. Colonic tumours in patients with Lynch syndrome are more likely to be right sided tumours and to be poorly differentiated. Genetics and surgical disease Some of the more commonly occurring genetic conditions occurring in surgical patients are presented here. Li-Fraumeni Syndrome Autosomal dominant Consists of germline mutations to p53 tumour suppressor gene High incidence of malignancies particularly sarcomas and leukaemias Diagnosed when: *Individual develops sarcoma under 45 years *First degree relative diagnosed with any cancer below age 45 years and another family member develops malignancy under 45 years or sarcoma at any age BRCA 1 and 2 Carried on chromosome 17 (BRCA 1) and Chromosome 13 (BRCA 2) Linked to developing breast cancer (60%) risk. Associated risk of developing ovarian cancer (55% with BRCA 1 and 25% with BRCA 2). Lynch Syndrome Autosomal dominant Develop colonic cancer and endometrial cancer at young age 80% of affected individuals will get colonic and/ or endometrial cancer High risk individuals may be identified using the Amsterdam criteria Amsterdam criteria Three or more family members with a confirmed diagnosis of colorectal cancer, one of whom is a first degree (parent, child, sibling) relative of the other two. Two successive affected generations. One or more colon cancers diagnosed under age 50 years. Familial adenomatous polyposis (FAP) has been excluded. Gardners syndrome Autosomal dominant familial colorectal polyposis Multiple colonic polyps Extra colonic diseases include: skull osteoma, thyroid cancer and epidermoid cysts Desmoid tumours are seen in 15% Mutation of APC gene located on chromosome 5 Due to colonic polyps most patients will undergo colectomy to reduce risk of colorectal cancer Now considered a variant of familial adenomatous polyposis coli

Answer 515

This patient has primary hyperparathyroidism and nephrolithiasis, which is an indication for parathyroidectomy. Parathyroid glands and disorders of calcium metabolism Hyperparathyroidism Disease type Hormone profile Clinical features Cause Primary hyperparathyroidism PTH (Elevated) Ca2+ (Elevated) Phosphate (Low) Urine calcium : creatinine clearance ratio > 0.01 May be asymptomatic if mild Recurrent abdominal pain (pancreatitis, renal colic) Changes to emotional or cognitive state Most cases due to solitary adenoma (80%), multifocal disease occurs in 10-15% and parathyroid carcinoma in 1% or less Secondary hyperparathyroidism PTH (Elevated) Ca2+ (Low or normal) Phosphate (Elevated) Vitamin D levels (Low) May have few symptoms Eventually may develop bone disease, osteitis fibrosa cystica and soft tissue calcifications Parathyroid gland hyperplasia occurs as a result of low calcium, almost always in a setting of chronic renal failure Tertiary hyperparathyroidism Ca2+ (Normal or high) PTH (Elevated) Phosphate levels (Decreased or Normal) Vitamin D (Normal or decreased) Alkaline phosphatase (Elevated) Metastatic calcification Bone pain and / or fracture Nephrolithiasis Pancreatitis Occurs as a result of ongoing hyperplasia of the parathyroid glands after correction of underlying renal disorder, hyperplasia of all 4 glands is usually the cause Differential diagnoses It is important to consider the rare but relatively benign condition of benign familial hypocalciuric hypercalcaemia, caused by an autosomal dominant genetic disorder. Diagnosis is usually made by genetic testing and concordant biochemistry (urine calcium : creatinine clearance ratio <0.01-distinguished from primary hyperparathyroidism). Treatment Primary hyperparathyroidism Indications for surgery Elevated serum Calcium > 1mg/dL above normal Hypercalciuria > 400mg/day Creatinine clearance < 30% compared with normal Episode of life threatening hypercalcaemia Nephrolithiasis Age < 50 years Neuromuscular symptoms Reduction in bone mineral density of the femoral neck, lumbar spine, or distal radius of more than 2.5 standard deviations below peak bone mass (T score lower than -2.5) Secondary hyperparathyroidism Usually managed with medical therapy. Indications for surgery in secondary (renal) hyperparathyroidism: Bone pain Persistent pruritus Soft tissue calcifications Tertiary hyperparathyroidism Allow 12 months to elapse following transplant as many cases will resolve The presence of an autonomously functioning parathyroid gland may require surgery. If the culprit gland can be identified then it should be excised. Otherwise total parathyroidectomy and re-implantation of part of the gland may be required. References 1. Insogna K. Primary Hyperparathyroidism. N Engl J Med. 2018 Sep 13;379(11):1050-1059. 2. van der Plas W Y et al. Secondary and Tertiary Hyperparathyroidism: A Narrative Review. Scand J Surg. 2020 Dec;109(4):271-278.

Answer 516

A sub total colectomy involves the removal of the entire right, transverse, left and part of the sigmoid colon. The rectal stump is closed and an end ileostomy fashioned in the right iliac fossa. Abdominal stomas Stomas may be sited during a range of abdominal procedures and involve bringing the lumen or visceral contents onto the skin. In most cases this applies to the bowel. However, other organs or their contents may be diverted in case of need. With bowel stomas the type method of construction and to a lesser extent the site will be determined by the contents of the bowel. In practice, small bowel stomas should be spouted so that their irritant contents are not in contact with the skin. Colonic stomas do not need to be spouted as their contents are less irritant. In the ideal situation the site of the stoma should be marked with the patient prior to surgery. Stoma siting is important as it will ultimately influence the ability of the patient to manage their stoma and also reduce the risk of leakage. Leakage of stoma contents and subsequent maceration of the surrounding skin can rapidly progress into a spiraling loss of control of stoma contents. Types of stomas Name of stoma Use Common sites Gastrostomy Gastric decompression or fixation Feeding Epigastrium Loop jejunostomy Seldom used as very high output May be used following emergency laparotomy with planned early closure Any location according to need Percutaneous jejunostomy Usually performed for feeding purposes and site in the proximal bowel Usually left upper quadrant Loop ileostomy Defunctioning of colon e.g. following rectal cancer surgery Does not decompress colon (if ileocaecal valve competent) Usually right iliac fossa End ileostomy Usually following complete excision of colon or where ileo-colic anastomosis is not planned May be used to defunction colon, but reversal is more difficult Usually right iliac fossa End colostomy Where a colon is diverted or resected and anastomosis is not primarily achievable or desirable Either left or right iliac fossa Loop colostomy To defunction a distal segment of colon Since both lumens are present the distal lumen acts as a vent May be located in any region of the abdomen, depending upon colonic segment used Caecostomy Stoma of last resort where loop colostomy is not possible Right iliac fossa Mucous fistula To decompress a distal segment of bowel following colonic division or resection Where closure of a distal resection margin is not safe or achievable May be located in any region of the abdomen according to clinical need

Answer 517

Mnemonic for intrinsic hand muscles 'A OF A OF A' A bductor pollicis brevis O pponens pollicis F lexor pollicis brevis A dductor pollicis (thenar muscles) O pponens digiti minimi F lexor digiti minimi brevis A bductor digiti minimi (hypothenar muscles) Palmaris longus originates in the forearm. Hand Anatomy of the hand Bones 8 Carpal bones 5 Metacarpals 14 phalanges Intrinsic Muscles 8 Interossei - Supplied by ulnar nerve 4 palmar-adduct fingers 4 dorsal- abduct fingers Intrinsic muscles Lumbricals Flex MCPJ and extend the IPJ. Origin deep flexor tendon and insertion dorsal extensor hood mechanism. Innervation: 1st and 2nd- median nerve, 3rd and 4th- deep branch of the ulnar nerve. Thenar eminence Abductor pollicis brevis Opponens pollicis Flexor pollicis brevis Hypothenar eminence Opponens digiti minimi Flexor digiti minimi brevis Abductor digiti minimi Fascia and compartments of the palm The fascia of the palm is continuous with the antebrachial fascia and the fascia of the dorsum of the hand. The palmar fascia is thin over the thenar and hypothenar eminences. In contrast, the central palmar fascia is relatively thick. The palmar aponeurosis covers the soft tissues and overlies the flexor tendons. The apex of the palmar aponeurosis is continuous with the flexor retinaculum and the palmaris longus tendon. Distally, it forms four longitudinal digital bands that attach to the bases of the proximal phalanges, blending with the fibrous digital sheaths. A medial fibrous septum extends deeply from the medial border of the palmar aponeurosis to the 5th metacarpal. Lying medial to this are the hypothenar muscles. In a similar fashion, a lateral fibrous septum extends deeply from the lateral border of the palmar aponeurosis to the 3rd metacarpal. The thenar compartment lies lateral to this area. Lying between the thenar and hypothenar compartments is the central compartment. It contains the flexor tendons and their sheaths, the lumbricals, the superficial palmar arterial arch and the digital vessels and nerves. The deepest muscular plane is the adductor compartment, which contains adductor pollicis. Short muscles of the hand These comprise the lumbricals and interossei. The four slender lumbrical muscles flex the fingers at the metacarpophalangeal joints and extend the interphalangeal joint. The four dorsal interossei are located between the metacarpals and the four palmar interossei lie on the palmar surface of the metacarpals in the interosseous compartment of the hand. Long flexor tendons and sheaths in the hand The tendons of FDS and FDP enter the common flexor sheath deep to the flexor retinaculum. The tendons enter the central compartment of the hand and fan out to their respective digital synovial sheaths. Near the base of the proximal phalanx, the tendon of FDS splits to permit the passage of FDP. The FDP tendons are attached to the margins of the anterior aspect of the base of the distal phalanx. The fibrous digital sheaths contain the flexor tendons and their synovial sheaths. These extend from the heads of the metacarpals to the base of the distal phalanges. Palmar Interossei Note that there are 4 palmar interossei. The first is a small slip of muscle which arises from the ulnar side of the base of the first metacarpal and passes between the head of the first dorsal interosseous and the oblique head of adductor pollicis to insert into the ulnar base of the of the proximal phalanx of the thumb. The second arises from the ulnar side of the body of the second metacarpal and is inserted into the ulnar side of the extensor hood of the index. The third and fourth palmar interossei arise from the radial sides of the bodies of the 4th and 5th metacarpals respectively and insert into the radial sides of the extensor hoods of the ring and little fingers.

Answer 518

Anatomical dead space is measured by Fowlers method. A patient inhales 100% oxygen to empty the conducting zone gases of nitrogen and then exhales through a mouthpiece which analyses the nitrogen concentration at the mouth. Initially the exhaled gases contain no nitrogen as this is dead space gas; the nitrogen concentration will increase as the alveolar gases are exhaled. Nitrogen which is measured following the breath of 100% oxygen must then have come only from gas exchanging areas of the lung and not dead space. Alveolar ventilation - Minute ventilation is the total volume of gas ventilated per minute. MV (ml/min)= tidal volume x Respiratory rate (resps/min). Dead space ventilation describes the volume of gas not involved in exchange in the blood. There are 2 types: 1. Anatomical dead space: 150mls Volume of gas in the respiratory tree not involved in gaseous exchange: mouth, pharynx, trachea, bronchi up to terminal bronchioles Measured by Fowlers method Increased by: Standing, increased size of person, increased lung volume and drugs causing bronchodilatation e.g. Adrenaline 2. Physiological dead space: normal 150 mls, increases in ventilation/perfusion mismatch e.g. PE, COPD, hypotension Volume of gas in the alveoli and anatomical dead space not involved in gaseous exchange. Alveolar ventilation is the volume of fresh air entering the alveoli per minute. Alveolar ventilation = minute ventilation - Dead space volume Alveolar ventilation

Answer 519

The greater petrosal nerve may be injured and carries fibres for lacrimation (see below). Lacrimal system Lacrimal gland Consists of an orbital part and palpebral part. They are continuous posterolaterally around the concave lateral edge of the levator palpebrae superioris muscle. The ducts of the lacrimal gland open into the superior fornix. Those from the orbital part penetrate the aponeurosis of levator palpebrae superioris to join those from the palpebral part. Therefore excision of the palpebral part is functionally similar to excision of the entire gland. Blood supply Lacrimal branch of the opthalmic artery. Venous drainage is to the superior opthalmic vein. Innervation The gland is innervated by the secretomotor parasympathetic fibres from the pterygopalatine ganglion which in turn may reach the gland via the zygomatic or lacrimal branches of the maxillary nerve or pass directly to the gland. The preganglionic fibres travel to the ganglion in the greater petrosal nerve (a branch of the facial nerve at the geniculate ganglion). Nasolacrimal duct Descends from the lacrimal sac to open anteriorly in the inferior meatus of the nose. Lacrimation reflex Occurs in response to conjunctival irritation (or emotional events). The conjunctiva will send signals via the opthalmic nerve. These then pass to the superior salivary centre. The efferent signals pass via the greater petrosal nerve (parasympathetic preganglionic fibres) and the deep petrosal nerve which carries the post ganglionic sympathetic fibres. The parasympathetic fibres will relay in the pterygopalatine ganglion, the sympathetic fibres do not synapse. They in turn will relay to the lacrimal apparatus.

Answer 520

Acquired factor 12 deficiency Vitamin K deficiency results from cholestatic jaundice and prolonged antibiotic therapy. Acquired factor 12 deficiency causes prolonged APTT. Abnormal coagulation Cause Factors affected Heparin Prevents activation factors 2,9,10,11 Warfarin Affects synthesis of factors 2,7,9,10 DIC Factors 1,2,5,8,11 Liver disease Factors 1,2,5,7,9,10,11 Interpretation blood clotting test results Disorder APTT PT Bleeding time Haemophilia Increased Normal Normal von Willebrand's disease Increased Normal Increased Vitamin K deficiency Increased Increased Normal

Answer 521

Recurrence occurs in 60% cases Classical features include: a limp, back pain and fever. Recurrence rates are about 15-20%. In the UK, Staphylococcus is the commonest primary cause, others include Streptococcus and E.coli. Management is ideally by CT guided drainage. Iliopsoas abscess - Collection of pus in iliopsoas compartment (iliopsoas and iliacus) Causes: Primary Haematogenous spread of bacteria Staphylococcus aureus: most common Secondary Crohn's (commonest cause in this category) Diverticulitis, Colorectal cancer UTI, GU cancers Vertebral osteomyelitis Femoral catheter, lithotripsy Endocarditis Note the mortality rate can be up to 19-20% in secondary iliopsoas abscesses compared with 2.4% in primary abscesses. Clinical features Fever Back/flank pain Limp Weight loss Clinical examination Patient in the supine position with the knee flexed and the hip mildly externally rotated Specific tests to diagnose iliopsoas inflammation: Place hand proximal to the patient's ipsilateral knee and ask patient to lift thigh against your hand. This will cause pain due to contraction of the psoas muscle. Lie the patient on the normal side and hyperextend the affected hip. In inflammation this should elicit pain as the psoas muscle is stretched. Investigation CT is gold standard Management Antibiotics Percutaneous drainage Surgery is indicated if: 1. Failure of percutaneous drainage 2. Presence of an another intra-abdominal pathology which requires surgery Surgical approach The authors technique for draining these collections is given here. Review the CT scans and plan surgical approach. An extraperitoneal approach is important. The collection usually extends inferiorly and can be accessed from an incision at a level of L4 on the affected side. GA Transverse laterally placed incision. Incise external oblique. Split the subsequent muscle layers. As you approach the peritoneum use blunt dissection to pass laterally around it. Remember the ureter and gonadal veins lie posterior at this level. Eventually you will enter the abscess cavity, a large amount of pus is usually released at this point. Drain the area with suction and washout with saline. Place a corrugated drain well into the abscess cavity. If you have made a small skin incision it is reasonable to bring the drain up through the skin wound. Otherwise place a lateral exit site and close the skin and external oblique. If you do this ensure that you use interrupted sutures. Anchor the drain with strong securely tied silk sutures (it is extremely tiresome if it falls out!) Reference Iliopsoas abscesses I H Mallick, M H Thoufeeq, T P Rajendran Postgrad Med J 2004;80:459-462

Answer 522

It is not linked to cigarette smoking. When identified at an early stage a radical resection is the favored option. Radiotherapy is often given perioperatively. However, it is not a particularly radiosensitive tumour. Combination chemotherapy gives some of the best results and most regimes are cisplatin based. Occupational cancers Occupational cancers accounted for 5.3% cancer deaths in 2005. In men the main cancers include: Mesothelioma Bladder cancer Non melanoma skin cancer Lung cancer Sino nasal cancer Occupations with high levels of occupational tumours include: Construction industry Working with coal tar and pitch Mining Metalworkers Working with asbestos (accounts for 98% of all mesotheliomas) Working in rubber industry Shift work has been linked to breast cancer in women (Health and safety executive report RR595). The latency between exposure and disease is typically 15 years for solid tumours and 20 for leukaemia. Many occupational cancers are otherwise rare. For example sino nasal cancer is an uncommon tumour, 50% will be SCC. They are linked to conditions such as wood dust exposure and unlike lung cancer is not strongly linked to cigarette smoking. Another typical occupational tumour is angiosarcoma of the liver which is linked to working with vinyl chloride. Again in the non occupational context this is an extremely rare sporadic tumour.

Answer 523

The reticuloendothelial cells are concerned with the immune functions of the spleen and these are therefore concentrated in the white pulp. Spleen- function The spleen is a reticuloendothelial organ, it develops in the dorsal mesogastrium at around 5 weeks gestation. At this stage it has an irregular surface and migrates to the left upper quadrant over the following weeks. In most cases the irregular hillocks on the spleen surface unify, when they fail to do so, accessory spleens may develop and are found in around 20% of people. The spleen is composed of both red and white pulp. In the red pulp, blood filled venous sinuses are found. In the white pulp, reticuloendothelial cords and white lymphoid follicles are present. Blood flows into the spleen at a rate of 150ml per minute. As blood passes through the spleen, the erythrocytes have to pass through fine endothelial fenestrations, older and less deformable erythrocytes are trapped during this process and destroyed. Red cell inclusion bodies such as parasites or residual nuclear components are split off during this process which is termed pitting. Functions of spleen Maintenance of the quality of erythrocytes in the red pulp by removal of senescent and dysfunctional cells Antibody production in the white pulp Removal of antibody coated bacteria and blood cells from the circulation Because of these important functions, the spleen is seldom removed. Indications for splenectomy include major trauma and uncontrollable haemorrhage and the treatment of haemolytic anaemia. The absence of a spleen has minimal long term effects on the haematologic profile. In the immediate post operative period, both leucocytosis and thrombocytosis are seen. In the longer term, the main manifestations are visible on the blood film and include visible nuclear remnants (Howell Jolly bodies), denatured haemoglobin (Heinz bodies), basophilic stippling and occasional nucleated erythrocytes. The main risk following splenectomy is overwhelming sepsis with encapsulated organisms. Patients should receive the pneumococcal vaccine and long term antibiotic prophylaxis.

Answer 524

The zygomatic nerve is transmitted via the inferior orbital fissure. A useful mnemonic for the structures that pass through the superior orbital fissure: SUPERIOR ORBITAL FISSURE: Outside L - lacrimal F - frontal T - trochlear done Inside N - nasociliary A - abducens nerve O - oculomotor nerve LFT done outside No Abnormality Occurred inside Orbital foramina Foramina Structures transmitted Superior orbital fissure Recurrent meningeal artery* Lacrimal nerve Trochlear nerve Abducens nerve Superior ophthalmic vein Superior division of the oculomotor nerve Inferior orbital fissure Maxillary nerve Inferior ophthalmic vein Zygomatic nerve Optic foramen Optic nerve Ophthalmic artery *=It may help to know that it is also termed the anastomotic branch ( of the middle meningeal artery). It enters the orbit lateral in the superior orbital fissure, it anastomoses with the recurrent branch of the lacrimal artery.

Answer 525

Serratus anterior Winging of the scapula is most commonly the result of long thoracic nerve injury or dysfunction. Iatrogenic damage during the course of the difficult axillary dissection is the most likely cause in this scenario. Damage to the rhomboids may produce winging of the scapula but would be rare in the scenario given. Long thoracic nerve Derived from ventral rami of C5, C6, and C7 (close to their emergence from intervertebral foramina) It runs downward and passes either anterior or posterior to the middle scalene muscle It reaches upper tip of serratus anterior muscle and descends on outer surface of this muscle, giving branches into it Winging of Scapula occurs in long thoracic nerve injury (most common) or from spinal accessory nerve injury (which denervates the trapezius) or a dorsal scapular nerve injury

Answer 526

It passes through the diaphragm at T8. Inferior vena cava Origin L5 Path Left and right common iliac veins merge to form the IVC. Passes right of midline Paired segmental lumbar veins drain into the IVC throughout its length The right gonadal vein empties directly into the cava and the left gonadal vein generally empties into the left renal vein. The next major veins are the renal veins and the hepatic veins Pierces the central tendon of diaphragm at T8 Right atrium Relations Anteriorly Small bowel, first and third part of duodenum, head of pancreas, liver and bile duct, right common iliac artery, right gonadal artery Posteriorly Right renal artery, right psoas, right sympathetic chain, coeliac ganglion Levels Level Vein T8 Hepatic vein, inferior phrenic vein, pierces diaphragm L1 Right suprarenal vein, renal vein L2 Gonadal vein L1-5 Lumbar veins L5 Common iliac vein, formation of IVC

Answer 527

The high salivary viscosity of submandibular gland secretions favors stone formation. Most stones are radio-opaque. The marginal mandibular nerve is the most superficial structure. The facial artery lies between the gland and mandible and is often ligated during excision of the gland. The lingual artery may be encountered but this is usually later in the operative process as Whartons duct is mobilised. Submandibular gland Relations of the submandibular gland Superficial Platysma, deep fascia and mandible Submandibular lymph nodes Facial vein (facial artery near mandible) Marginal mandibular nerve Cervical branch of the facial nerve Deep Facial artery (inferior to the mandible) Mylohyoid muscle Sub mandibular duct Hyoglossus muscle Lingual nerve Submandibular ganglion Hypoglossal nerve Submandibular duct (Wharton's duct) Opens lateral to the lingual frenulum on the anterior floor of mouth. 5 cm length Lingual nerve wraps around Wharton's duct. As the duct passes forwards it crosses medial to the nerve to lie above it and then crosses back, lateral to it, to reach a position below the nerve. Innervation Sympathetic innervation- Derived from superior cervical ganglion Parasympathetic innervation- Submandibular ganglion via lingual nerve Arterial supply Branch of the facial artery. The facial artery passes through the gland to groove its deep surface. It then emerges onto the face by passing between the gland and the mandible. Venous drainage Anterior facial vein (lies deep to the Marginal Mandibular nerve) Lymphatic drainage Deep cervical and jugular chains of nodes

Answer 528

Waldeyers fascia- Posterior ano-rectum Sibsons fascia- Lung apex Bucks fascia- Base of penis Gerotas fascia- Surrounding kidney Denonvilliers fascia- Between rectum and prostate Renal anatomy Each kidney is about 11cm long, 5cm wide and 3cm thick. They are located in a deep gutter alongside the projecting vertebral bodies, on the anterior surface of psoas major. In most cases the left kidney lies approximately 1.5cm higher than the right. The upper pole of both kidneys approximates with the 11th rib (beware pneumothorax during nephrectomy). On the left hand side the hilum is located at the L1 vertebral level and the right kidney at level L1-2. The lower border of the kidneys is usually alongside L3. The table below shows the anatomical relations of the kidneys: Relations Relations Right Kidney Left Kidney Posterior Quadratus lumborum, diaphragm, psoas major, transversus abdominis Quadratus lumborum, diaphragm, psoas major, transversus abdominis Anterior Hepatic flexure of colon Stomach, Pancreatic tail Superior Liver, adrenal gland Spleen, adrenal gland Fascial covering Each kidney and suprarenal gland is enclosed within a common layer of investing fascia, derived from the transversalis fascia. It is divided into anterior and posterior layers (Gerotas fascia). Renal structure Kidneys are surrounded by an outer cortex and an inner medulla which usually contains between 6 and 10 pyramidal structures. The papilla marks the innermost apex of these. They terminate at the renal pelvis, into the ureter. Lying in a hollow within the kidney is the renal sinus. This contains: 1. Branches of the renal artery 2. Tributaries of the renal vein 3. Major and minor calyces's 4. Fat Structures at the renal hilum The renal vein lies most anteriorly, then renal artery (it is an end artery) and the ureter lies most posterior.

Answer 529

If a stone cannot be removed at surgery then the chances of succeeding at ERCP are slim. In this case, its probably best to bypass the distal bile duct and a choledochoduodenostomy is the best way of achieving this. There are long term risks of cholangitis which are less of a concern in older patients. Biliary disease Diagnosis Typical features Pathogenesis Gallstones Typically history of biliary colic or episodes of chlolecystitis. Obstructive type history and test results. Usually small calibre gallstones which can pass through the cystic duct. In Mirizzi syndrome the stone may compress the bile duct directly- one of the rare times that cholecystitis may present with jaundice Cholangitis Usually obstructive and will have Charcot's triad of symptoms (pain, fever, jaundice) Ascending infection of the bile ducts usually by E. coli and by definition occurring in a pool of stagnant bile. Pancreatic cancer Typically painless jaundice with palpable gallbladder (Courvoisier's Law) Direct occlusion of distal bile duct or pancreatic duct by tumour. Sometimes nodal disease at the portal hepatis may be the culprit in which case the bile duct may be of normal calibre. TPN (total parenteral nutrition) associated jaundice Usually follows long term use and is usually painless with non obstructive features Often due to hepatic dysfunction and fatty liver which may occur with long term TPN usage. Bile duct injury Depending upon the type of injury may be of sudden or gradual onset and is usually of obstructive type Often due to a difficult laparoscopic cholecystectomy when anatomy in Calots triangle is not appreciated. In the worst scenario the bile duct is excised and jaundice develops rapidly post operatively. More insidious is that of bile duct stenosis which may be caused by clips or diathermy injury. Cholangiocarcinoma Gradual onset obstructive pattern Direct occlusion by disease and also extrinsic compression by nodal disease at the porta hepatis. Septic surgical patient Usually hepatic features Combination of impaired biliary excretion and drugs such as ciprofloxacin which may cause cholestasis. Metastatic disease Mixed hepatic and post hepatic Combination of liver synthetic failure (late) and extrinsic compression by nodal disease and anatomical compression of intra hepatic structures (earlier) A gallbladder may develop a thickened wall in chronic cholecystitis, microscopically Roikitansky-Aschoff Sinuses may be seen

Answer 530

The left main bronchus lies at T6. Topographical anatomy of the thorax is important as it helps surgeons to predict the likely structures to be injured in trauma scenarios (so popular with examiners) Lung anatomy The right lung is composed of 3 lobes divided by the oblique and transverse fissures. The left lung has two lobes divided by the oblique fissure.The apex of both lungs is approximately 4cm superior to the sterno-costal joint of the first rib. Immediately below this is a sulcus created by the subclavian artery. Peripheral contact points of the lung Base: diaphragm Costal surface: corresponds to the cavity of the chest Mediastinal surface: Contacts the mediastinal pleura. Has the cardiac impression. Above and behind this concavity is a triangular depression named the hilum, where the structures which form the root of the lung enter and leave the viscus. These structures are invested by pleura, which, below the hilum and behind the pericardial impression, forms the pulmonary ligament Right lung Above the hilum is the azygos vein; Superior to this is the groove for the superior vena cava and right innominate vein; behind this, and nearer the apex, is a furrow for the innominate artery. Behind the hilum and the attachment of the pulmonary ligament is a vertical groove for the oesophagus; In front and to the right of the lower part of the oesophageal groove is a deep concavity for the extrapericardiac portion of the inferior vena cava. The root of the right lung lies behind the superior vena cava and the right atrium, and below the azygos vein. The right main bronchus is shorter, wider and more vertical than the left main bronchus and therefore the route taken by most foreign bodies. Left lung Above the hilum is the furrow produced by the aortic arch, and then superiorly the groove accommodating the left subclavian artery; Behind the hilum and pulmonary ligament is a vertical groove produced by the descending aorta, and in front of this, near the base of the lung, is the lower part of the oesophagus. The root of the left lung passes under the aortic arch and in front of the descending aorta. Inferior borders of both lungs 6th rib in mid clavicular line 8th rib in mid axillary line 10th rib posteriorly The pleura runs two ribs lower than the corresponding lung level. Bronchopulmonary segments Segment number Right lung Left lung 1 Apical Apical 2 Posterior Posterior 3 Anterior Anterior 4 Lateral Superior lingular 5 Medial Inferior lingular 6 Superior (apical) Superior (apical) 7 Medial basal Medial basal 8 Anterior basal Anterior basal 9 Lateral basal Lateral basal 10 Posterior basal Posterior basal

Answer 531

The transversalis fascia forms the superolateral edge of the deep inguinal ring. The epigastric vessels form its inferomedial wall. Inguinal canal Location Above the inguinal ligament The inguinal canal is 4cm long The superficial ring is located anterior to the pubic tubercle The deep ring is located approximately 1.5-2cm above the half way point between the anterior superior iliac spine and the pubic tubercle Boundaries of the inguinal canal Floor External oblique aponeurosis Inguinal ligament Lacunar ligament Roof Internal oblique Transversus abdominis Anterior wall External oblique aponeurosis Posterior wall Transversalis fascia Conjoint tendon Laterally Internal ring Transversalis fascia Fibres of internal oblique Medially External ring Conjoint tendon Contents Males Spermatic cord and ilioinguinal nerve As it passes through the canal the spermatic cord has 3 coverings: External spermatic fascia from external oblique aponeurosis Cremasteric fascia Internal spermatic fascia Females Round ligament of uterus and ilioinguinal nerve

Answer 532

Lobular carcinoma in situ has a low association with invasive malignancy. It is seldom associated with microcalcification and therefore MRI is the best tool for determining disease extent. Resection of in situ disease is not generally recommended and most surgeons would simply pursue a policy of close clinical and radiological follow up. Lobular carcinoma of the breast Lobular breast cancers are less common than their ductal counterparts. They typically present differently, the mass is usually more diffuse and less obvious on the usual imaging modalities of ultrasound and mammography. This is significant since the disease may be understaged resulting in inadequate treatment when wide local excision is undertaken. In women with invasive lobular carcinoma it is usually safest to perform an MRI scan of the breast, if breast conserving surgery is planned. Lobular carcinomas are also more likely to be multifocal and metastasise to the contralateral breast. Lobular carcinoma in situ is occasionally diagnosed incidentally on core biopsies. Unlike DCIS, lobular carcinoma in situ is far less strongly associated with foci of invasion and is usually managed by close monitoring.

Answer 533

Methylene blue stains the parathyroid glands and can be useful in facilitating their identification. Preparation for surgery Elective and emergency patients require different preparation. Elective cases Consider pre admission clinic to address medical issues. Blood tests including FBC, U+E, LFT's, Clotting, Group and Save Urine analysis Pregnancy test Sickle cell test ECG/ Chest x-ray Exact tests to be performed will depend upon the proposed procedure and patient fitness. Risk factors for development of deep vein thrombosis should be assessed and a plan for thromboprophylaxis formulated. Diabetes Diabetic patients have greater risk of complications. Poorly controlled diabetes carries high risk of wound infections. Patients with diet or tablet controlled diabetes may be managed using a policy of omitting medication and checking blood glucose levels regularly. Diabetics who are poorly controlled or who take insulin may require a intravenous sliding scale. Potassium supplementation should also be given. Diabetic cases should be operated on first. Emergency cases Stabilise and resuscitate where needed. Consider whether antibiotics are needed and when and how they should be administered. Inform blood bank if major procedures planned particularly where coagulopathies are present at the outset or anticipated (e.g. Ruptured AAA repair) Don't forget to consent and inform relatives. Special preparation Some procedures require special preparation: Thyroid surgery; vocal cord check. Parathyroid surgery; consider methylene blue to identify gland. Sentinel node biopsy; radioactive marker/ patent blue dye. Surgery involving the thoracic duct; consider administration of cream. Pheochromocytoma surgery; will need alpha and beta blockade. Surgery for carcinoid tumours; will need covering with octreotide. Colorectal cases; bowel preparation (especially left sided surgery) Thyrotoxicosis; lugols iodine/ medical therapy.

Answer 534

The vitelline arteries supply a Meckels these are usually derived from the ileal arcades. Meckel's diverticulum - Congenital abnormality resulting in incomplete obliteration of the vitello-intestinal duct Normally, in the foetus, there is an attachment between the vitello-intestinal duct and the yolk sac.This disappears at 6 weeks gestation. The tip is free in majority of cases. Associated with enterocystomas, umbilical sinuses, and omphaloileal fistulas. Arterial supply: omphalomesenteric artery. 2% of population, 2 inches long, 2 feet from the ileocaecal valve. Typically lined by ileal mucosa but ectopic gastric mucosa can occur, with the risk of peptic ulceration. Pancreatic and jejunal mucosa can also occur. Clinical Normally asymptomatic and an incidental finding. Complications are the result of obstruction, ectopic tissue, or inflammation. Removal if narrow neck or symptomatic. Options are between wedge excision or formal small bowel resection and anastomosis.

Answer 535

Right-to-left shunting is characteristic of Fallot's. In some patients there can be bidirectional shunting (if there is mild pulmonary stenosis) and a few patients can even have pink tetralogy when there is a predominant shunt from left to right due to minimal infundibular stenosis. Tetralogy of Fallot Tetralogy of Fallot (TOF) is the most common cause of cyanotic congenital heart disease*. It typically presents at around 1-2 months, although may not be picked up until the baby is 6 months old The four characteristic features are: ventricular septal defect (VSD) right ventricular hypertrophy right ventricular outflow tract obstruction, pulmonary stenosis overriding aorta The severity of the right ventricular outflow tract obstruction determines the degree of cyanosis and clinical severity Other features cyanosis causes a right-to-left shunt ejection systolic murmur due to pulmonary stenosis (the VSD doesn't usually cause a murmur) a right-sided aortic arch is seen in 25% of patients chest x-ray shows a 'boot-shaped' heart, ECG shows right ventricular hypertrophy Management surgical repair is often undertaken in two parts cyanotic episodes may be helped by beta-blockers to reduce infundibular spasm *however, at birth transposition of the great arteries is the more common lesion as patients with TOF generally present at around 1-2 months

Answer 536

Charcots triad = Surgical emergency. Patients need: Biliary decompression and broad spectrum antibiotics. E Coli is the most common organism implicated in cholangitis infections. Whilst enterobacter is occasionally cultured it is not the most common organism. Cholangitis - Combination of bacterial infection and biliary obstruction Most common organisms are: (most frequent at top of list) Escherichia coli Klebsiella species Enterococcus species Streptococcus species Clinical features Charcot's triad: Fever (90% cases) Right upper quadrant pain Jaundice Reynolds pentad: Above plus confusion and hypotension Investigations USS 1st line CT scan ERCP: may be 1st line if high clinical suspicion and suitable for treatment Treatment ERCP -usually after 72 hours of antibiotics Percutaneous transhepatic cholangiogram and biliary drain

Answer 537

The radial nerve lies in this groove and may be compromised by fractures involving the shaft. Humerus The humerus extends from the scapula to the elbow joint. It has a body and two ends. It is almost completely covered with muscle but can usually be palpated throughout its length. The smooth rounded surface of the head articulates with the shallow glenoid cavity. The head is connected to the body of the humerus by the anatomical neck. The surgical neck is the region below the head and tubercles and where they join the shaft and is the commonest site of fracture. The capsule of the shoulder joint is attached to the anatomical neck superiorly but extends down to 1.5cm on the surgical neck. The greater tubercle is the prominence on the lateral side of the upper end of the bone. It merges with the body below and can be felt through the deltoid inferior to the acromion. The tendons of the supraspinatus and infraspinatus are inserted into impressions on its superior aspect. The lesser tubercle is a distinct prominence on the front of the upper end of the bone. It can be palpated through the deltoid just lateral to the tip of the coracoid process. The intertubercular groove passes on the body between the greater and lesser tubercles, continuing down from the anterior borders of the tubercles to form the edges of the groove. The tendon of biceps within its synovial sheath passes through this groove, held within it by a transverse ligament. The posterior surface of the body is marked by a spiral groove for the radial nerve which runs obliquely across the upper half of the body to reach the lateral border below the deltoid tuberosity. Within this groove lie the radial nerve and brachial vessels and both may be affected by fractures involving the shaft of the humerus. The lower end of the humerus is wide and flattened anteroposteriorly, and inclined anteriorly. The middle third of the distal edge forms the trochlea. Superior to this are indentations for the coronoid fossa anteriorly and olecranon fossa posteriorly. Lateral to the trochlea is a rounded capitulum which articulates with the radius. The medial epicondyle is very prominent with a smooth posterior surface which contains a sulcus for the ulnar nerve and collateral vessels. It's distal margin gives attachment for the ulnar collateral ligament and, in front of this, the anterior surface has an impression for the common flexor tendon.

Answer 538

5 alpha reductase inhibitors reduce the risk of urinary retention. In the PLESS study, data show a reduction in the risk of urinary retention although the absolute risk reduction was small. Finasteride is a medication used to treat benign prostatic hyperplasia (BPH) by reducing the size of the prostate gland. It works by inhibiting the conversion of testosterone to dihydrotestosterone (DHT), which is a hormone that contributes to the growth of the prostate gland. Alfuzosin, tamsulosin, and terazosin are medications that belong to a class of drugs called alpha-blockers. These medications work by relaxing the smooth muscle in the prostate gland and bladder neck, which can improve urine flow and decrease urinary symptoms. While alpha-blockers are effective in improving urinary symptoms associated with BPH, they do not reduce the size of the prostate gland and are not associated with a reduction in the risk of urinary retention. Prazosin is an alpha-blocker that is used to treat high blood pressure and post-traumatic stress disorder (PTSD). It is not typically used to treat urinary symptoms associated with BPH Reference McConnell J et al. The effect of finasteride on the risk of urinary retention and the need for surgical intervention amongst men with benign prostatic hyperplasia. N Engl J Med 338:557-563

Answer 539

As this patient most likely has anaphylaxis, administration of adrenaline is most appropriate. Anaphylactic shock - Suspect if there has been exposure to an allergen Management - Remove allergen - ABCD - Drugs: Adrenaline 1:1000 0.5ml INTRAMUSCULARLY (not IV). Repeat after 5 mins if no response. Consider antihistamine if ongoing local symptoms. In the refractory anaphylaxis guidance, consideration is given to adrenaline infusions. Reference Emergency treatment of anaphylactic reactions. Guidelines for healthcare providers. Working Group of the Resuscitation Council (UK).2021

Answer 540

Do not confuse the early phase of Charcot foot with cellulitis Trauma (even if only minor) is a prerequisite. Patients cannot usually recall the traumatic event. The associated neuropathy means that patients continue to walk on the affected foot with subsequent deformity developing over time. Peripheral vascular disease Indications for surgery to revascularise the lower limb Intermittent claudication Critical ischaemia Ulceration Gangrene Intermittent claudication that is not disabling may provide a relative indication, whilst the other complaints are often absolute indications depending upon the frailty of the patient. Assessment Clinical examination Ankle brachial pressure index measurement Duplex arterial ultrasound Angiography (standard, CT or MRI): usually performed only if intervention being considered. Angioplasty In order for angioplasty to be undertaken successfully the artery has to be accessible. The lesion relatively short and reasonable distal vessel runoff. Longer lesions may be amenable to sub-intimal angioplasty. Surgery Surgery will be undertaken where attempts at angioplasty have either failed or are unsuitable. Bypass essentially involves bypassing the affected arterial segment by utilising a graft to run from above the disease to below the disease. As with angioplasty good runoff improves the outcome. Some key concepts with bypass surgery Superficial femoral artery occlusion to the above knee popliteal In the ideal scenario, vein (either in situ or reversed LSV) would be used as a conduit. However, prosthetic material has reasonable 5 year patency rates and some would advocate using this in preference to vein so that vein can be used for other procedures in the future. In general terms either technique is usually associated with an excellent outcome (if run off satisfactory). Procedure Artery dissected out, IV heparin 3,000 units given and then the vessels are cross clamped Longitudinal arteriotomy Graft cut to size and tunneled to arteriotomy sites Anastomosis to femoral artery usually with 5/0 'double ended' Prolene suture Distal anastomosis usually using 6/0 'double ended' Prolene Distal disease Femoro-distal bypass surgery takes longer to perform, is more technically challenging and has higher failure rates. In elderly diabetic patients with poor runoff a primary amputation may well be a safer and more effective option. There is no point in embarking on this type of surgery in patients who are wheelchair bound. In femorodistal bypasses vein gives superior outcomes to PTFE. Rules Vein mapping 1st to see whether there is suitable vein (the preferred conduit). Sub intimal hyperplasia occurs early when PTFE is used for the distal anastomosis and will lead to early graft occlusion and failure. Essential operative procedure as for above knee fem-pop. If there is insufficient vein for the entire conduit then vein can be attached to the end of the PTFE graft and then used for the distal anastomosis. This type of 'vein boot' is technically referred to as a Miller Cuff and is associated with better patency rates than PTFE alone. Remember the more distal the arterial anastomosis the lower the success rate. References Peach G et al. Diagnosis and management of peripheral arterial disease. BMJ 2012; 345: 36-41.

Answer 541

The new legal judgement recognises this individual approach to warning patients about risk. Rather than taking into account the percentage possibility of a risk arising, doctors need to bear in mind the significance of a given risk for that particular patient, and the nature of the risk, such as the effect it would have on the patient's life if it were to occur. The assessment is therefore considered to be both fact-sensitive and sensitive to the characteristics of the particular patient. Consent There are 3 types of consent: 1. Informed 2. Expressed 3. Implied Consent forms used in UK NHS Consent Form 1 For competent adults who are able to consent for themselves where consciousness may be impaired (e.g. GA) Consent Form 2 For an adult consenting on behalf of a child where consciousness is impaired Consent Form 3 For an adult or child where consciousness is not impaired Consent Form 4 For adults who lack capacity to provide informed consent Capacity Key points include: 1. Understand and retain information 2. Patient believes the information to be true 3. Patient is able to weigh the information to make a decision All patients must be assumed to have capacity Consent in minors Young children and older children who are not Gillick competent cannot consent for themselves. In British law the patients biological mother can always provide consent. The child's father can consent if the parents are married (and the father is the biological father), or if the father is named on the birth certificate (irrespective of marital status). If parents are not married and the father is not named on the birth certificate then the father cannot consent.

Answer 542

Rectal varices are a recognised complication of portal hypertension. In the first instance they can be managed with medical therapy to lower pressure in the portal venous system. TIPSS may be considered. Whilst band ligation is an option, attempting to inject these in same way as haemorroids would carry a high risk of precipitating further haemorrhage. Lower Gastrointestinal bleeding Colonic bleeding This typically presents as bright red or dark red blood per rectum. Colonic bleeding rarely presents as malaena type stool, this is because blood in the colon has a powerful laxative effect and is rarely retained long enough for transformation to occur and because the digestive enzymes present in the small bowel are not present in the colon. Up to 15% of patients presenting with haemochezia will have an upper gastrointestinal source of haemorrhage. As a general rule right sided bleeds tend to present with darker coloured blood than left sided bleeds. Haemorrhoidal bleeding typically presents as bright red rectal bleeding that occurs post defecation either onto toilet paper or into the toilet pan. It is very unusual for haemorrhoids alone to cause any degree of haemodynamic compromise. Causes Cause Presenting features Colitis Bleeding may be brisk in advanced cases, diarrhoea is commonly present. Abdominal x-ray may show featureless colon. Diverticular disease Acute diverticulitis often is not complicated by major bleeding and diverticular bleeds often occur sporadically. 75% all will cease spontaneously within 24-48 hours. Bleeding is often dark and of large volume. Cancer Colonic cancers often bleed and for many patients this may be the first sign of the disease. Major bleeding from early lesions is uncommon Haemorrhoidal bleeding Typically bright red bleeding occurring post defecation. Although patients may give graphic descriptions bleeding of sufficient volume to cause haemodynamic compromise is rare. Angiodysplasia Apart from bleeding, which may be massive, these arteriovenous lesions cause little in the way of symptoms. The right side of the colon is more commonly affected. Management Prompt correction of any haemodynamic compromise is required. Unlike upper gastrointestinal bleeding the first line management is usually supportive. This is because in the acute setting endoscopy is rarely helpful. When haemorrhoidal bleeding is suspected a proctosigmoidoscopy is reasonable as attempts at full colonoscopy are usually time consuming and often futile. In the unstable patient the usual procedure would be an angiogram (either CT or percutaneous), when these are performed during a period of haemodynamic instability they may show a bleeding point and may be the only way of identifying a patch of angiodysplasia. In others who are more stable the standard procedure would be a colonoscopy in the elective setting. In patients undergoing angiography attempts can be made to address the lesion in question such as coiling. Otherwise surgery will be necessary. In patients with ulcerative colitis who have significant haemorrhage the standard approach would be a sub total colectomy, particularly if medical management has already been tried and is not effective. Indications for surgery Patients > 60 years Continued bleeding despite endoscopic intervention Recurrent bleeding Known cardiovascular disease with poor response to hypotension Surgery Selective mesenteric embolisation if life threatening bleeding. This is most helpful if conducted during a period of relative haemodynamic instability. If all haemodynamic parameters are normal then the bleeding is most likely to have stopped and any angiography normal in appearance. In many units a CT angiogram will replace selective angiography but the same caveats will apply. If the source of colonic bleeding is unclear; perform a laparotomy, on table colonic lavage and following this attempt a resection. A blind sub total colectomy is most unwise, for example bleeding from an small bowel arterio-venous malformation will not be treated by this manoeuvre. Summary of Acute Lower GI bleeding recommendations Consider admission if: * Over 60 years * Haemodynamically unstable/profuse PR bleeding * On aspirin or NSAID * Significant co morbidity Management All patients should have a history and examination, PR and proctoscopy Colonoscopic haemostasis aimed for in post polypectomy or diverticular bleeding References http://www.sign.ac.uk/guidelines/fulltext/105/index.html

Answer 543

Chronic iron deficiency anemia Mnemonic to remember causes of right shift of the oxygen dissociation curve: CADET face RIGHT C O2 A cidosis 2,3-DPG E xercise T emperature The curve is shifted to the right when there is an increased oxygen requirement by the tissue. This includes: Increased temperature Acidosis Increased DPG: DPG is found in erythrocytes and is increased during glycolysis. It binds to the Hb molecule, thereby releasing oxygen to tissues. DPG is increased in conditions associated with poor oxygen delivery to tissues, such as anaemia and high altitude.

Answer 544

Follicular carcinomas are a recognised cause of bone metastasis. Papillary lesions typically spread via the lymphatics. Thyroid malignancy Papillary carcinoma Commonest sub-type Accurately diagnosed on fine needle aspiration cytology Histologically, they may demonstrate psammoma bodies (areas of calcification) and so called 'orphan Annie' nuclei They typically metastasise via the lymphatics and thus laterally located apparently ectopic thyroid tissue is usually a metastasis from a well differentiated papillary carcinoma Follicular carcinoma Are less common than papillary lesions Like papillary tumours, they may present as a discrete nodule. Although they appear to be well encapsulated macroscopically there is invasion on microscopic evaluation Lymph node metastases are uncommon and these tumours tend to spread haematogenously. This translates into a higher mortality rate Follicular lesions cannot be accurately diagnosed on fine needle aspiration cytology and thus all follicular FNA's (THY 3f) will require at least a hemi thyroidectomy Anaplastic carcinoma Less common and tend to occur in elderly females Disease is usually advanced at presentation and often only palliative decompression and radiotherapy can be offered. Medullary carcinoma These are tumours of the parafollicular cells ( C Cells) and are of neural crest origin. The serum calcitonin may be elevated which is of use when monitoring for recurrence. They may be familial and occur as part of the MEN -2A disease spectrum. Spread may be either lymphatic or haematogenous and as these tumours are not derived primarily from thyroid cells they are not responsive to radioiodine. Lymphoma These respond well to combined chemoradiotherapy Radical surgery is unnecessary once the disease has been diagnosed on biopsy material. Such biopsy material is not generated by an FNA and thus a core biopsy has to be obtained (with care!).

Answer 545

The layers that will be encountered are (in order): 1. Skin 2. Dartos fascia and muscle 3. External spermatic fascia 4. Cremasteric muscle and fascia 5. Internal spermatic fascia 6. Parietal layer of the tunica vaginalis The layers of the spermatic cord and scrotum are a popular topic in the MRCS exam. A mnemonic which may help: Some Damned Examiner Called It The Testes (skin dartos external fascia cremaster internal fascia tunica Testes) Scrotal and testicular anatomy Spermatic cord Formed by the vas deferens and is covered by the following structures: Layer Origin Internal spermatic fascia Transversalis fascia Cremasteric fascia From the fascial coverings of internal oblique External spermatic fascia External oblique aponeurosis Contents of the cord Vas deferens Transmits sperm and accessory gland secretions Testicular artery Branch of abdominal aorta supplies testis and epididymis Artery of vas deferens Arises from inferior vesical artery Cremasteric artery Arises from inferior epigastric artery Pampiniform plexus Venous plexus, drains into right or left testicular vein Sympathetic nerve fibres Lie on arteries, the parasympathetic fibres lie on the vas Genital branch of the genitofemoral nerve Supplies cremaster Lymphatic vessels Drain to lumbar and para-aortic nodes Scrotum Composed of skin and closely attached dartos fascia. Arterial supply from the anterior and posterior scrotal arteries Lymphatic drainage to the inguinal lymph nodes Parietal layer of the tunica vaginalis is the innermost layer Testes The testes are surrounded by the tunica vaginalis (closed peritoneal sac). The parietal layer of the tunica vaginalis adjacent to the internal spermatic fascia. The testicular arteries arise from the aorta immediately inferiorly to the renal arteries. The pampiniform plexus drains into the testicular veins, the left drains into the left renal vein and the right into the inferior vena cava. Lymphatic drainage is to the para-aortic nodes.

Answer 546

Glucagonoma is strongly associated with necrolytic migratory erythema. Glucagonoma Rare pancreatic tumours arising from the alpha cells of the pancreas. Glucagon levels markedly elevated. Symptoms include diarrhoea, weight loss and necrolytic migratory erythema. A serum level of glucagon >1000pg/ml usually suggests the diagnosis, imaging with CT scanning is also required. Treatment is with surgical resection. However, careful staging is required for these tumours are usually malignant and non resectable.

Answer 547

A laminar flow is the single most important intervention, many units will also use exhaust suits but these are less essential. Shaving skin on the ward increases infection rates. Extended chemoprophylaxis increases risks of antibiotic associated diarrhea. Surgical site infection - Surgical site infections may occur following a breach in tissue surfaces and allow normal commensals and other pathogens to initiate infection. They are a major cause of morbidity and mortality. Surgical site infections (SSI) comprise up to 20% of all healthcare associated infections and at least 5% of patients undergoing surgery will develop an SSI as a result. In many cases the organisms are derived from the patient's own body. Measures that may increase the risk of SSI include: Shaving the wound using a razor (disposable clipper preferred) Using a non iodine impregnated incise drape if one is deemed to be necessary Tissue hypoxia Delayed administration of prophylactic antibiotics in tourniquet surgery Preoperatively Don't remove body hair routinely If hair needs removal, use electrical clippers with single use head (razors increase infection risk) Antibiotic prophylaxis if: - placement of prosthesis or valve - clean-contaminated surgery - contaminated surgery Use local formulary Aim to give single dose IV antibiotic on anaesthesia If a tourniquet is to be used, give prophylactic antibiotics earlier Intraoperatively Prepare the skin with alcoholic chlorhexidine (Lowest incidence of SSI) Cover surgical site with dressing A recent meta analysis has confirmed that administration of supplementary oxygen does not reduce the risk of wound infection. In contrast to previous individual RCT's(1) Wound edge protectors do not appear to confer benefit (2) Post operatively Tissue viability advice for management of surgical wounds healing by secondary intention Use of diathermy for skin incisions In the NICE guidelines the use of diathermy for skin incisions is not advocated(3). Several randomised controlled trials have been undertaken and demonstrated no increase in risk of SSI when diathermy is used(4). References 1. Brar M et al.. Perioperative supplemental oxygen in colorectal patients: a meta analysis. J Surg Res 2011 (166): 227 -235. 2. Pinkney T et al. Impact of wound edge protection devices on surgical site infection after laparotomy: impact of a multicentre randomised controlled trial (ROSSINI Trial). BMJ 2013 (347):10. 3. http://www.nice.org.uk/CG74 4. Ahmad N and Ahmed A. Meta-analysis of the effectiveness of surgical scalpel or diathermy in making abdominal skin incisions. Ann Surg 2011, 253(1):8-13.

Answer 548

The hypoglossal nerve passes through the hypoglossal canal. Foramina of the base of the skull Foramen Location Contents Foramen ovale Sphenoid bone Otic ganglion V3 (Mandibular nerve:3rd branch of trigeminal) Accessory meningeal artery Lesser petrosal nerve Emissary veins Foramen spinosum Sphenoid bone Middle meningeal artery Meningeal branch of the Mandibular nerve Foramen rotundum Sphenoid bone Maxillary nerve (V2) Foramen lacerum/ carotid canal Located between the sphenoid, the apex of the petrous temporal and the basilar part of the occipital Base of the medial pterygoid plate. Internal carotid artery* Nerve and artery of the pterygoid canal Jugular foramen Temporal bone Anterior: inferior petrosal sinus Intermediate: glossopharyngeal, vagus, and accessory nerves. Posterior: sigmoid sinus (becoming the internal jugular vein) and some meningeal branches from the occipital and ascending pharyngeal arteries. Foramen magnum Occipital bone Anterior and posterior spinal arteries Vertebral arteries Medulla oblongata Stylomastoid foramen Temporal bone Stylomastoid artery Facial nerve Superior orbital fissure Sphenoid bone Oculomotor nerve (III) Recurrent meningeal artery Trochlear nerve (IV) Lacrimal, frontal and nasociliary branches of opthalmic nerve (V1) Abducent nerve (VI) Superior ophthalmic vein *= In life the foramen lacerum is occluded by a cartilagenous plug. The ICA initially passes into the carotid canal which ascends superomedially to enter the cranial cavity through the foramen lacerum.

Answer 549

Fracture of the radial head is common in young adults. It is usually caused by a fall on the outstretched hand. On examination, there is marked local tenderness over the head of the radius, impaired movements at the elbow, and a sharp pain at the lateral side of the elbow at the extremes of rotation (pronation and supination). Upper limb fractures Colles' fracture Fall onto extended outstretched hands Described as a dinner fork type deformity Classical Colles' fractures have the following 3 features: Features of the injury 1. Transverse fracture of the radius 2. 1 inch proximal to the radio-carpal joint 3. Dorsal displacement and angulation Smith's fracture (reverse Colles' fracture) Volar angulation of distal radius fragment (Garden spade deformity) Caused by falling backwards onto the palm of an outstretched hand or falling with wrists flexed Bennett's fracture Intra-articular fracture of the first carpometacarpal joint Impact on flexed metacarpal, caused by fist fights X-ray: triangular fragment at ulnar base of metacarpal Monteggia's fracture Dislocation of the proximal radioulnar joint in association with an ulna fracture Fall on outstretched hand with forced pronation Needs prompt diagnosis to avoid disability Galeazzi fracture Radial shaft fracture with associated dislocation of the distal radioulnar joint Occur after a fall on the hand with a rotational force superimposed on it. On examination, there is bruising, swelling and tenderness over the lower end of the forearm. X Rays reveal the displaced fracture of the radius and a prominent ulnar head due to dislocation of the inferior radio-ulnar joint. Barton's fracture Distal radius fracture (Colles'/Smith's) with associated radiocarpal dislocation Fall onto extended and pronated wrist Scaphoid fractures Scaphoid fractures are the commonest carpal fractures. Surface of scaphoid is covered by articular cartilage with small area available for blood vessels (fracture risks blood supply) Forms floor of anatomical snuffbox Risk of fracture associated with fall onto outstretched hand (tubercle, waist, or proximal 1/3) The main physical signs are swelling and tenderness in the anatomical snuff box, and pain on wrist movements and on longitudinal compression of the thumb. Ulnar deviation AP needed for visualization of scaphoid Immobilization of scaphoid fractures difficult Radial head fracture Fracture of the radial head is common in young adults. It is usually caused by a fall on the outstretched hand. On examination, there is marked local tenderness over the head of the radius, impaired movements at the elbow, and a sharp pain at the lateral side of the elbow at the extremes of rotation (pronation and supination).

Answer 550

The cerebellopontine angle is located between the superior and inferior limbs of the angular cerebellopontine fissure formed by the petrosal cerebellar surface folding around the pons and middle cerebellar peduncle. The cerebellopontine fissure opens medially and has superior and inferior limbs that meet at a lateral apex. The fourth through the eleventh cranial nerves are located near or within the angular space between the two limbs commonly referred to as the cerebellopontine angle. The commonest lesion to affect this site is an acoustic neuroma. Therefore the vestibulocochlear nerve is commonly compromised. Larger lesions may also affect the facial nerve which lies closest to this site. Cranial nerves Cranial nerve lesions Olfactory nerve May be injured in basal skull fractures or involved in frontal lobe tumour extension. Loss of olfactory nerve function in relation to major CNS pathology is seldom an isolated event and thus it is poor localiser of CNS pathology. Optic nerve Problems with visual acuity may result from intra ocular disorders. Problems with the blood supply such as amaurosis fugax may produce temporary visual distortion. More important surgically is the pupillary response to light. The pupillary size may be altered in a number of disorders. Nerves involved in the resizing of the pupil connect to the pretectal nucleus of the high midbrain, bypassing the lateral geniculate nucleus and the primary visual cortex. From the pretectal nucleus neurones pass to the Edinger - Westphal nucleus, motor axons from here pass along with the oculomotor nerve. They synapse with ciliary ganglion neurones; the parasympathetic axons from this then innervate the iris and produce miosis. The miotic pupil is seen in disorders such as Horner's syndrome or opiate overdose. Mydriasis is the dilatation of the pupil in response to disease, trauma, drugs (or the dark!). It is pathological when light fails to induce miosis. The radial muscle is innervated by the sympathetic nervous system. Because the parasympathetic fibres travel with the oculomotor nerve they will be damaged by lesions affecting this nerve (e.g. cranial trauma). The response to light shone in one eye is usually a constriction of both pupils. This indicates intact direct and consensual light reflexes. When the optic nerve has an afferent defect the light shining on the affected eye will produce a diminished pupillary response in both eyes. Whereas light shone on the unaffected eye will produce a normal pupillary response in both eyes. This is referred to as the Marcus Gunn pupil and is seen in conditions such as optic neuritis. In a total CN II lesion shining the light in the affected eye will produce no response. Oculomotor nerve The pupillary effects are described above. In addition it supplies all ocular muscles apart from lateral rectus and superior oblique. Thus the affected eye will be deviated inferolaterally. Levator palpebrae superioris may also be impaired resulting in impaired ability to open the eye. Trochlear nerve The eye will not be able to look down. Trigeminal nerve Largest cranial nerve. Exits the brainstem at the pons. Branches are ophthalmic, maxillary and mandibular. Only the mandibular branch has both sensory and motor fibres. Branches converge to form the trigeminal ganglion (located in Meckels cave). It supplies the muscles of mastication and also tensor veli palatine, mylohyoid, anterior belly of digastric and tensor tympani. The detailed descriptions of the various sensory functions are described in other areas of the website. The corneal reflex is important and is elicited by applying a small tip of cotton wool to the cornea, a reflex blink should occur if it is intact. It is mediated by: the naso ciliary branch of the ophthalmic branch of the trigeminal (sensory component) and the facial nerve producing the motor response. Lesions of the afferent arc will produce bilateral absent blink and lesions of the efferent arc will result in a unilateral absent blink. Abducens nerve The affected eye will have a deficit of abduction. This cranial nerve exits the brainstem between the pons and medulla. It thus has a relatively long intra cranial course which renders it susceptible to damage in raised intra cranial pressure. Facial nerve Emerges from brainstem between pons and medulla. It controls muscles of facial expression and taste from the anterior 2/3 of the tongue. The nerve passes into the petrous temporal bone and into the internal auditory meatus. It then passes through the facial canal and exits at the stylomastoid foramen. It passes through the parotid gland and divides at this point. It does not innervate the parotid gland. Its divisions are considered in other parts of the website. Its motor fibres innervate orbicularis oculi to produce the efferent arm of the corneal reflex. In surgical practice it may be injured during parotid gland surgery or invaded by malignancies of the gland and a lower motor neurone on the ipsilateral side will result. Vestibulo-cochlear nerve Exits from the pons and then passes through the internal auditory meatus. It is implicated in sensorineural hearing loss. Individuals with sensorineural hearing loss will localise the sound in webers test to the normal ear. Rinnes test will be reduced on the affected side but should still work. These two tests will distinguish sensorineural hearing loss from conductive deafness. In the latter condition webers test will localise to the affected ear and Rinnes test will be impaired on the affected side. Surgical lesions affecting this nerve include CNS tumours and basal skull fractures. It may also be damaged by the administration of ototoxic drugs (of which gentamicin is the most commonly used in surgical practice). Glossopharyngeal nerve Exits the pons just above the vagus. Receives sensory fibres from posterior 1/3 tongue, tonsils, pharynx and middle ear (otalgia may occur following tonsillectomy). It receives visceral afferents from the carotid bodies. It supplies parasympathetic fibres to the parotid gland via the otic ganglion and motor function to stylopharyngeaus muscle. The sensory function of the nerve is tested using the gag reflex. Vagus nerve Leaves the medulla between the olivary nucleus and the inferior cerebellar peduncle. Passes through the jugular foramen and into the carotid sheath. Details of the functions of the vagus nerve are covered in the website under relevant organ sub headings. Accessory nerve Exists from the caudal aspect of the brainstem (multiple branches) supplies trapezius and sternocleidomastoid muscles. The distal portion of this nerve is most prone to injury during surgical procedures. Hypoglossal nerve Emerges from the medulla at the preolivary sulcus, passes through the hypoglossal canal. It lies on the carotid sheath and passes deep to the posterior belly of digastric to supply muscles of the tongue (except palatoglossus). Its location near the carotid sheath makes it vulnerable during carotid endarterectomy surgery and damage will produce ipsilateral defect in muscle function.

Answer 551

Polycythaemia is a recognised feature of renal cell carcinoma. Wilms tumours most commonly occur in children. Haematuria Causes of haematuria Trauma Injury to renal tract Renal trauma commonly due to blunt injury (others penetrating injuries) Ureter trauma rare: iatrogenic Bladder trauma: due to RTA or pelvic fractures Infection Remember TB Malignancy Renal cell carcinoma (remember paraneoplastic syndromes): painful or painless Urothelial malignancies: 90% are transitional cell carcinoma, can occur anywhere along the urinary tract. Painless haematuria. Squamous cell carcinoma and adenocarcinoma: rare bladder tumours Prostate cancer Penile cancers: SCC Renal disease Glomerulonephritis Stones Microscopic haematuria common Structural abnormalities Benign prostatic hyperplasia (BPH) causes haematuria due to hypervascularity of the prostate gland Cystic renal lesions e.g. polycystic kidney disease Vascular malformations Renal vein thrombosis due to renal cell carcinoma Coagulopathy Causes bleeding of underlying lesions Drugs Cause tubular necrosis or interstitial nephritis: aminoglycosides, chemotherapy Interstitial nephritis: penicillin, sulphonamides, and NSAIDs Anticoagulants Benign Exercise Gynaecological Endometriosis: flank pain, dysuria, and haematuria that is cyclical Iatrogenic Catheterisation Radiotherapy; cystitis, severe haemorrhage, bladder necrosis Pseudohaematuria For example following consumption of beetroot References Http://bestpractice.bmj.com/best-practice/monograph/316/overview/aetiology.html

Answer 552

It is likely to be underpowered with the number provided. However, it would be possible to classify such data into a 2x2 contingency table. However, when the sample size is small, the Chi squared test is not suitable and in these situations the Fishers exact test is used. Statistics Statistics is a topic that generally strikes fear and dread into most surgeons hearts. The MRCS is not an examination designed to test mathematical skill but the examiners do expect you to have working knowledge of commonly used tests so that you can appraise the literature properly. Data types Before selecting a method of statistical analysis it is imperative that the type of data to be analysed is correctly categorised. Commonly used terms include nominal, ordinal, interval and continuous. Term Interpretation Nominal Data can be allocated a numerical code that is arbitrary. For example allocating people as alive or dead using codes of 0 or 1 Ordinal data Data using numbers that can be used on a scale. Severity of pain is often measured in this way Interval scale Data is measured numerically. However, the zero point is arbitrary Continuous Data is measured numerically where the numerical value is a real number and may be any value. Examples include height and weight Analysing data Having ascribed the data it is then possible to begin the process of analysis. Nominal data is often tabulated into categories because of the nature of the underlying data sets. Continuous data may be displayed graphically often as individual data points. When the sample size is large enough, continuous data can be analysed to determine the distribution of the data points. Often, but not always these will be in the form of a gaussian distribution. Determining whether data is normally distributed or not is key to making sense of the subsequent statistical tests. Parametric tests are used to test normally distributed data, the T Test is one of the best examples. Data which is not normally distributed cannot be analysed in this way and a non parametric test must be used. Examples of such tests include Chi Squared and Mann Whitney U tests. Chi squared tests often appear in the medical literature. There are some assumptions that are made in relation to Chi squared tests; these include the need to use 2 degrees of freedom (usually) and the minimum sample size. Where the sample size is small then a different test is appropriate and the Fishers exact test is often used. In situations where data is normally distributed and paired samples are taken from the same individuals (such as following an intervention) then the paired T Test may be used. Multiple testing and post hoc analysis In the ideal world statistical analysis is conducted on data that is collected prospectively according to pre set power calculations and defined end points. Occasionally, data does not produce an expected outcome or a certain type of patient appears to have a different result. Subsequent analysis of such groups is termed a post hoc analysis. This can be perfectly legitimate, alternatively it can represent the last ditch attempt of a researcher to try and find any aspect of the data that is worthwhile. This can lead to errors and false rejection of a null hypothesis. A statistically significant result is more likely to occur if the same dataset is subjected to multiple analyses. To counteract this problem some researchers will apply a Bonferroni correction, this adjusts the analysis to allow for multiple testing.

Answer 553

In modern venous surgery, decision making is based on venous imaging to determine which treatment modality is best. Few surgeons would proceed straight to surgery and excision without this test. A venous doppler would show incompetence of the valve but not more than that. Vascular investigations Venous disease Venous Doppler The simplest investigation for assessment of venous junctional incompetence is a Doppler assessment. This involves the patient standing and manual compression of the limb distal to the junction of interest. Flow should normally occur in one direction only. Where junctional incompetence is present reverse flow will occur and is relatively easy to identify. Venograms and duplex scans Structural venous information is historically obtained using a venogram. This is an invasive test and rarely required in modern clinical practice. The most helpful test is a venous duplex scan which will provide information relating to flow and vessel characteristics. Duplex is also useful in providing vein maps for bypass surgery. Arterial disease Ankle-brachial pressure The ankle brachial pressure index measurement is an important investigation as it will allow classification of the severity of the flow compromise present. False readings may occur in those with calcified vessels such as diabetics and results in such settings should be interpreted with caution. When auscultating the vessel note should be made of the character of the signal. Monophasic signals are associated with a proximal stenosis and reduction in flow. Triphasic signals provide reassurance of a healthy vessel. Arterial Duplex As with the vein the duplex scan can provide a substantial amount of information about arterial patency and flow patterns. In skilled hands they can provide insight as to the state of proximal vessels that are anatomically inaccessible to duplex (e.g. Iliacs). Through assessment of distal flow patterns. It is an operator dependent test. Conventional angiogram Vessel puncture and catheter angiography is the gold standard method of assessing arteries. High quality information can usually be obtained. Limitations of the technique include the risk of contrast toxicity and risks of vessel damage. Severely calcified vessels may be difficult to puncture and in this situation a remote access site (e.g. brachial) may be used. This technique is particularly useful in providing a distal arterial roadmap prior to femoro-distal bypass. CT angiography These tests provide a considerable amount of structural and flow information. They require contrast and thus carry the risks associated with this. They are particularly useful in the setting of GI bleeding as they are rapidly available and can be performed by a non vascular radiologist. However, they lack the facility for endovascular intervention. In general they do not provide high enough resolution for distal arterial surgery. Magnetic resonance angiography This has the advantage of being non-invasive and not using nephrotoxic contrast. Movement artifact remains a problem in some sites and distal arterial resolution is imperfect.

Answer 554

Three cranial nerves may be injured during submandibular gland excision. Marginal mandibular branch of the facial nerve Lingual nerve Hypoglossal nerve Hypoglossal nerve damage may result in paralysis of the ipsilateral aspect of the tongue. The nerve itself lies deep to the capsule surrounding the gland and should not be injured during an intracapsular dissection. The lingual nerve is probably at greater risk of injury. However, the effects of lingual nerve injury are sensory rather than motor. Submandibular gland Relations of the submandibular gland Superficial Platysma, deep fascia and mandible Submandibular lymph nodes Facial vein (facial artery near mandible) Marginal mandibular nerve Cervical branch of the facial nerve Deep Facial artery (inferior to the mandible) Mylohyoid muscle Sub mandibular duct Hyoglossus muscle Lingual nerve Submandibular ganglion Hypoglossal nerve Submandibular duct (Wharton's duct) Opens lateral to the lingual frenulum on the anterior floor of mouth. 5 cm length Lingual nerve wraps around Wharton's duct. As the duct passes forwards it crosses medial to the nerve to lie above it and then crosses back, lateral to it, to reach a position below the nerve. Innervation Sympathetic innervation- Derived from superior cervical ganglion Parasympathetic innervation- Submandibular ganglion via lingual nerve Arterial supply Branch of the facial artery. The facial artery passes through the gland to groove its deep surface. It then emerges onto the face by passing between the gland and the mandible. Venous drainage Anterior facial vein (lies deep to the Marginal Mandibular nerve) Lymphatic drainage Deep cervical and jugular chains of nodes

Answer 555

Malignant otitis externa is caused by Pseudomonas aeruginosa Severe pain, headaches and granulation tissue within the external auditory meatus are key features of malignant otitis externa. Diabetes mellitus is one of the commonest risk factors. Malignant otitis externa - Uncommon type of otitis externa that is found in immunocompromised individuals (90% cases found in diabetics) Infective organism is usually Pseudomonas aeruginosa Infection commences in the soft tissues of the external auditory meatus, then progresses to involve the soft tissues and into the bony ear canal Progresses to temporal bone osteomyelitis Key features in history Diabetes (90%) or immunosuppression (illness or treatment related) Severe, unrelenting, deep-seated otalgia Temporal headaches Purulent otorrhea Possibly dysphagia, hoarseness, and/or facial nerve dysfunction Treatment Anti pseudomonal antimicrobial agents Topical agents Hyperbaric oxygen is sometimes used in refractory cases

Answer 556

The Ampulla of Vater is usually located 8-10cm from the pylorus and 2-3cm inferior to the opening of the accessory pancreatic duct of the lesser duodenal papilla. Knowledge of the location of the Ampulla is important when cannulating it at ERCP. Duodenum This is the first and widest part of the small bowel. It has a diameter of around 4-5cm. Its commencement is immediately distal to the pylorus and it runs for around 25cm where it becomes the jejunum at the region of the duodenojejunal flexure. It comprises four parts, superior, descending, horizontal and ascending. Of these, the horizontal is the longest segment. The first 2-3cm of the superior duodenum are intraperitoneal. The remainder is largely retroperitoneal with the exception of the final 1-2cm. Medial relations of the duodenum include the superior pancreatico-duodenal artery and the pancreatic head. The descending duodenum is closely related to the commencement of the transverse colon which has little in the way of mesentery at this area. Posterior to the descending duodenum lies the right kidney. The horizontal part passes transversely to the left with an upward deflection as it does so. From right to left it crosses in front of the right ureter, right psoas major, right gonadal vessels and IVC. It terminates anterior to the aorta. Anteriorly, it's relations include the superior mesenteric vessels and the root of the small bowel. The ascending part runs to the left of the aorta and upwards to the level of L2. It terminates by binding abruptly forwards as the duodenojejunal flexure. Posteriorly, are the left sympathetic trunk, left psoas major and left gonadal vessels. Anteriorly, it gives attachment to the root of the mesentery, while the left kidney lies laterally and the uncinate process of the pancreas lies medially. The region of the duodenojenunal flexure is fixed in position by the suspensory muscle of the duodenum. This fibromuscular band blends with the musculature of the flexure and passes upwards deep to the pancreas to gain attachment to the right crus of the diaphragm. It is referred to eponymously as the ligament of Treitz.

Answer 557

The sural nerve lies behind the distal fibula. Inversion and eversion are sub talar movements. The structures passing behind the medial malleolus from anterior to posterior include: tibialis posterior, flexor digitorum longus, posterior tibial vein, posterior tibial artery, nerve, flexor hallucis longus. Ankle joint The ankle joint is a synovial joint composed of the tibia and fibula superiorly and the talus inferiorly. Ligaments of the ankle joint Deltoid ligament (medially) Lateral collateral ligament Talofibular ligaments (both anteriorly and posteriorly) The calcaneofibular ligament is separate from the fibrous capsule of the joint. The two talofibular ligaments are fused with it. The components of the syndesmosis are Antero-inferior tibiofibular ligament Postero-inferior tibiofibular ligament Inferior transverse tibiofibular ligament Interosseous ligament Movements at the ankle joint Plantar flexion (55 degrees) Dorsiflexion (35 degrees) Inversion and eversion movements occur at the level of the sub talar joint Nerve supply Branches of deep peroneal and tibial nerves. References Golano P et al. Anatomy of the ankle ligaments: a pictorial essay. Knee Surg Sports Traumatol Arthrosc. 2010 May;18(5):557-69

Answer 558

Invasion is the hallmark of malignancy. The others may occur in insitu disease or dysplastic lesions. Tissue sampling Tissue sampling is an important surgical process. Biopsy modalities vary according to the site, experience and subsequent planned therapeutic outcome The modalities comprise: -Fine needle aspiration cytology -Core biopsy -Excision biopsy -Tru cut biopsy -Punch biopsy -Cytological smears -Endoscopic or laparoscopic biopsy When the lesion is superficial the decision needs to be taken as to whether complete excision is desirable or whether excision biopsy is acceptable. In malignant melanoma for example the need for safe margins will mean that a more radical surgical approach needs to be adopted after diagnostic confirmation from excision biopsy than would be the case in basal cell carcinoma. Punch biopsies are useful in gaining histological diagnosis of unclear skin lesions where excision biopsy is undesirable such as in establishing whether a skin lesion is vasculitic or not. Fine needle aspiration cytology (FNAC) is an operator dependent procedure that may or may not be image guided and essentially involves passing a needle through a lesion whilst suction is applied to a syringe. The material thus obtained is expressed onto a slide and sent for cytological assessment. This test can be limited by operator inexperience and also by the lack of histological architectural information (e.g. Follicular carcinoma of the thyroid). Where a discharge is present a sample may be sent for cytology although in some sites (e.g. Nipple discharge ) the information gleaned may be meaningless. Tissue samples may be obtained by both core and tru cut biopsy. A core biopsy is obtained by use of a spring loaded gun with a needle passing quickly through the lesion of interest. A tru cut biopsy achieves the same objective but the needle moved by hand. When performing these techniques image guidance may be desirable (e.g. In breast lesions). Consideration needs to be given to any planned surgical resection as it may be necessary to resect the biopsy tract along with the specimen (e.g. In sarcoma surgery). Visceral lesions may be accessed percutaneously under image guidance such as ultrasound guided biopsy of liver metastases. Or under direct vision such as a colonoscopic biopsy.

Answer 559

The testicular venous drainage begins in the septa and these veins together with those of the tunica vasculosa converge on the posterior border of the testis as the pampiniform plexus. The pampiniform plexus drains to the testicular vein. The left testicular vein drains into the left renal vein. The right testicular vein drains into the inferior vena cava. Scrotal and testicular anatomy Spermatic cord Formed by the vas deferens and is covered by the following structures: Layer Origin Internal spermatic fascia Transversalis fascia Cremasteric fascia From the fascial coverings of internal oblique External spermatic fascia External oblique aponeurosis Contents of the cord Vas deferens Transmits sperm and accessory gland secretions Testicular artery Branch of abdominal aorta supplies testis and epididymis Artery of vas deferens Arises from inferior vesical artery Cremasteric artery Arises from inferior epigastric artery Pampiniform plexus Venous plexus, drains into right or left testicular vein Sympathetic nerve fibres Lie on arteries, the parasympathetic fibres lie on the vas Genital branch of the genitofemoral nerve Supplies cremaster Lymphatic vessels Drain to lumbar and para-aortic nodes Scrotum Composed of skin and closely attached dartos fascia. Arterial supply from the anterior and posterior scrotal arteries Lymphatic drainage to the inguinal lymph nodes Parietal layer of the tunica vaginalis is the innermost layer Testes The testes are surrounded by the tunica vaginalis (closed peritoneal sac). The parietal layer of the tunica vaginalis adjacent to the internal spermatic fascia. The testicular arteries arise from the aorta immediately inferiorly to the renal arteries. The pampiniform plexus drains into the testicular veins, the left drains into the left renal vein and the right into the inferior vena cava. Lymphatic drainage is to the para-aortic nodes.

Answer 560

Tumour markers Tumour markers may be divided into: monoclonal antibodies against carbohydrate or glycoprotein tumour antigens tumour antigens enzymes (alkaline phosphatase, neurone specific enolase) hormones (e.g. calcitonin, ADH) It should be noted that tumour markers usually have a low specificity Monoclonal antibodies Tumour marker Association CA 125 Ovarian cancer CA 19-9 Pancreatic cancer CA 15-3 Breast cancer NB: The breast cancer tumour marker is not specific or sensitive enough to be used routinely. Tumour antigens Tumour marker Association Prostate specific antigen (PSA) Prostatic carcinoma Alpha-feto protein (AFP) Hepatocellular carcinoma, teratoma Carcinoembryonic antigen (CEA) Colorectal cancer

Answer 561

The parasympathetic fibres to the lacrimal apparatus transit via the pterygopalatine ganglion. Lacrimal system Lacrimal gland Consists of an orbital part and palpebral part. They are continuous posterolaterally around the concave lateral edge of the levator palpebrae superioris muscle. The ducts of the lacrimal gland open into the superior fornix. Those from the orbital part penetrate the aponeurosis of levator palpebrae superioris to join those from the palpebral part. Therefore excision of the palpebral part is functionally similar to excision of the entire gland. Blood supply Lacrimal branch of the opthalmic artery. Venous drainage is to the superior opthalmic vein. Innervation The gland is innervated by the secretomotor parasympathetic fibres from the pterygopalatine ganglion which in turn may reach the gland via the zygomatic or lacrimal branches of the maxillary nerve or pass directly to the gland. The preganglionic fibres travel to the ganglion in the greater petrosal nerve (a branch of the facial nerve at the geniculate ganglion). Nasolacrimal duct Descends from the lacrimal sac to open anteriorly in the inferior meatus of the nose. Lacrimation reflex Occurs in response to conjunctival irritation (or emotional events). The conjunctiva will send signals via the opthalmic nerve. These then pass to the superior salivary centre. The efferent signals pass via the greater petrosal nerve (parasympathetic preganglionic fibres) and the deep petrosal nerve which carries the post ganglionic sympathetic fibres. The parasympathetic fibres will relay in the pterygopalatine ganglion, the sympathetic fibres do not synapse. They in turn will relay to the lacrimal apparatus.

Answer 562

Axonal degeneration distal to the site of injury Full recovery may occur 6-8 weeks after nerve injury in neuropraxia. Wallerian degeneration does not usually occur in simple neuropraxia. Autonomic function is usually preserved. Nerve injury There are 3 types of nerve injury: Neuropraxia Nerve intact but electrical conduction is affected Full recovery Autonomic function preserved Wallerian degeneration does not occur Axonotmesis Axon is damaged and the myelin sheath is preserved. The connective tissue framework is not affected. Wallerian degeneration occurs. Neurotmesis Disruption of the axon, myelin sheath and surrounding connective tissue. Wallerian degeneration occurs. Wallerian Degeneration Axonal degeneration distal to the site of injury. Typically begins 24-36 hours following injury. Axons are excitable prior to degeneration occurring. Myelin sheath degenerates and is phagocytosed by tissue macrophages. Nerve repair Neuronal repair may only occur physiologically where nerves are in direct contact. Where a large defect is present, the process of nerve regeneration is hampered. It may not occur at all or result in the formation of a neuroma. Where nerve regrowth occurs it is typically at a rate of 1mm per day.

Answer 563

Lipomas are typically small and mobile lesions. They may be multiple. Lesions >5cm may be indicative of a soft tissue sarcoma and additional diagnostic tests may be required prior to excision. Lipomata Benign tumour of adipocytes Occur in middle aged adults Smooth, mobile, painless Subtypes: Angiolipoma, Angiolipoleiomyoma Malignant transformation is rare Features suggestive of sarcomatous change Size >5cm Increasing size Pain Deep anatomical location In one series the presence of all 4 features was associated with up to 85% being sarcomatous (1). Lipoma removed surgically. Benign lesions are often small and well encapsulated. Deep seated or lesions larger than 5cm are at increased risk of being associated with sarcomatous change

Answer 564

Obturator nerve Deep perineal pouch The perineal pouch is surrounded inferiorly by the inferior fascia of the urogenital diaphragm. This fascial boundary extends laterally to form the medial wall of the ischiorectal fossa. The pouch is bounded superiorly by the superior fascia of the urogenital diaphragm and this lies beneath the levator ani muscle. Contents of the deep perineal pouch Urethral sphincter Transversus perinei Dorsal nerve of penis, muscular branches of the perineal nerve Deep and dorsal arteries of penis, stem of origin of artery to the bulb of penis, urethral artery.

Answer 565

Don't confuse AP resection and proctectomy. The former is a cancer related procedure. In patients with UC where medical management is not successful, surgical resection may offer a chance of cure. Those patients wishing to avoid a permanent stoma may be considered for an ileoanal pouch. However, this procedure is only offered in the elective setting. Surgery for inflammatory bowel disease Patients with inflammatory bowel disease (UC and Crohns) frequently present in surgical practice. Ulcerative colitis may be cured by surgical resection (Proctocolectomy), this is not the case in Crohns disease which may recur and affect other areas of the gastrointestinal tract. Ulcerative colitis Elective indications for surgery include disease that is requiring maximal therapy, or prolonged courses of steroids. Longstanding UC is associated with a risk of malignant transformation. Dysplastic transformation of the colonic epithelium with associated mass lesions is an absolute indication for a proctocolectomy. Emergency presentations of poorly controlled colitis that fails to respond to medical therapy should usually be managed with a sub total colectomy. Excision of the rectum is a procedure with a higher morbidity and is not generally performed in the emergency setting. An end ileostomy is usually created and the rectum either stapled off and left in situ, or, if the bowel is very oedematous, may be brought to the surface as a mucous fistula. Patients with IBD have a high incidence of DVT and appropriate thromboprophylaxis is mandatory. Restorative options in UC include an ileoanal pouch. This procedure can only be performed whilst the rectum is in situ and cannot usually be undertaken as a delayed procedure following proctectomy. Ileoanal pouch complications include, anastomotic dehiscence, pouchitis and poor physiological function with seepage and soiling. Crohns disease Surgical resection of Crohns disease does not equate with cure, but may produce substantial symptomatic improvement. Indications for surgery include complications such as fistulae, abscess formation and strictures. Extensive small bowel resections may result in short bowel syndrome and localised stricturoplasty may allow preservation of intestinal length. Staging of Crohns will usually involve colonoscopy and a small bowel study (e.g. MRI enteroclysis). Complex perianal fistulae are best managed with long term draining seton sutures, complex attempts at fistula closure e.g. advancement flaps, may be complicated by non healing and fistula recurrence. Severe perianal and / or rectal Crohns may require proctectomy. Ileoanal pouch reconstruction in Crohns carries a high risk of fistula formation and pouch failure and is not recommended. Terminal ileal Crohns remains the commonest disease site and these patients may be treated with limited ileocaecal resections. Terminal ileal Crohns may affect enterohepatic bile salt recycling and increase the risk of gallstones.

Answer 566

Electrical activity of the heart Myocardial action potential Phase Description Mechanism 0 Rapid depolarisation Rapid sodium influx These channels automatically deactivate after a few ms 1 Early repolarisation Efflux of potassium 2 Plateau Slow influx of calcium 3 Final repolarisation Efflux of potassium 4 Restoration of ionic concentrations Resting potential is restored by Na+/K+ ATPase There is slow entry of Na+ into the cell decreasing the potential difference until the threshold potential is reached, triggering a new action potential NB cardiac muscle remains contracted 10-15 times longer than skeletal muscle Conduction velocity Atrial conduction Spreads along ordinary atrial myocardial fibres at 1 m/sec AV node conduction 0.05 m/sec Ventricular conduction Purkinje fibres are of large diameter and achieve velocities of 2-4 m/sec (this allows a rapid and coordinated contraction of the ventricles

Answer 567

Establishing bladder drainage will often correct the situation. These patients often have a significant diuresis with associated electrolyte disturbance. The urethral route should be tried first. Hydronephrosis Causes of hydronephrosis Unilateral: PACT Pelvic-ureteric obstruction (congenital or acquired) Aberrant renal vessels Calculi Tumours of renal pelvis Bilateral: SUPER Stenosis of the urethra Urethral valve Prostatic enlargement Extensive bladder tumour Retro-peritoneal fibrosis Investigation USS- identifies presence of hydronephrosis and can assess the kidneys IVU- assess the position of the obstruction Antegrade or retrograde pyelography- allows treatment If renal colic suspected: non contrast CT scan (majority of stones are detected this way) Management Remove the obstruction and drainage of urine Acute upper urinary tract obstruction: Nephrostomy tube Chronic upper urinary tract obstruction: Ureteric stent or a pyeloplasty

Answer 568

Radiotherapy is routine following breast conserving surgery. Without irradiation the local recurrence rates are approximately 40%. These rates are potentially lower in older patients who receive endocrine therapy and who have small low grade tumours. Alongside this, an anti oestrogen will be needed. Breast cancer treatment Treatment Indication Endocrine therapy Oestrogen receptor positive tumours Downstaging primary lesions Definitive treatment in old, infirm patients Irradiation Wide local excision Large lesion, high grade or marked vascular invasion following mastectomy Chemotherapy Downstaging advanced lesions to facilitate breast conserving surgery Patients with grade 3 lesions or axillary nodal disease Endocrine agents Tamoxifen is used and works as a partial oestrogen receptor agonist. It will typically block activity at the breast. It does, however, stimulate the receptors at other sites and it is this that accounts for its association with endometrial cancer. In post menopausal women the process of aromatisation accounts for most oestrogen production. Therefore in this group aromatase inhibitors are the preferred agents. Women who are perimenopausal start on tamoxifen and switch at 3 years. More recent studies (aTTom and ATLAS) have demonstrated benefits for continuing the drug for 10 years. In pre-menopausal women, there is increasing preference for the use of Exemestane over tamoxifen. Chemotherapy The FEC regime is most commonly used (Fluorouracil, epirubicin and cyclophosphamide). This was found to be superior to the older CMF regime. The Taxanes are commonly used in high risk patients and in this setting a regime of docetaxal, doxorubicin and cyclophosphamide may be used. The anthracycline class drugs have marked cardiotoxicity (a property that they share with trastuzumab) and this can limit their use.

Answer 569

Goodsals rule: Anterior fistulae will tend to have an internal opening opposite the external opening. Posterior fistulae will tend to have a curved track that passes towards the midline. According to Goodsalls rule the track of a posteriorly sited fistula will track to the posterior midline (i.e. 6 o'clock) Fistulas A fistula is defined as an abnormal connection between two epithelial surfaces. There are many types ranging from Branchial fistulae in the neck to entero-cutaneous fistulae abdominally. In general surgical practice the abdominal cavity generates the majority and most of these arise from diverticular disease and Crohn's. As a general rule all fistulae will resolve spontaneously as long as there is no distal obstruction. This is particularly true of intestinal fistulae. The four types of fistulae are: Enterocutaneous These link the intestine to the skin. They may be high (>500ml) or low output (<250ml) depending upon source. Duodenal /jejunal fistulae will tend to produce high volume, electrolyte rich secretions which can lead to severe excoriation of the skin. Colo-cutaneous fistulae will tend to leak faeculent material. Both fistulae may result from the spontaneous rupture of an abscess cavity onto the skin (such as following perianal abscess drainage) or may occur as a result of iatrogenic input. In some cases it may even be surgically desirable e.g. mucous fistula following sub total colectomy for colitis. Suspect if there is excess fluid in the drain. Enteroenteric or Enterocolic This is a fistula that involves the large or small intestine. They may originate in a similar manner to enterocutaneous fistulae. A particular problem with this fistula type is that bacterial overgrowth may precipitate malabsorption syndromes. This may be particularly serious in inflammatory bowel disease. Enterovaginal Aetiology as above. Enterovesical This type of fistula goes to the bladder. These fistulas may result in frequent urinary tract infections, or the passage of gas from the urethra during urination. Management Some rules relating to fistula management: They will heal provided there is no underlying inflammatory bowel disease and no distal obstruction, so conservative measures may be the best option Where there is skin involvement, protect the overlying skin, often using a well fitted stoma bag- skin damage is difficult to treat A high output fistula may be rendered more easily managed by the use of octreotide, this will tend to reduce the volume of pancreatic secretions. Nutritional complications are common especially with high fistula (e.g. high jejunal or duodenal) these may necessitate the use of TPN to provide nutritional support together with the concomitant use of octreotide to reduce volume and protect skin. When managing perianal fistulae surgeons should avoid probing the fistula where acute inflammation is present, this almost always worsens outcomes. When perianal fistulae occur secondary to Crohn's disease the best management option is often to drain acute sepsis and maintain that drainage through the judicious use of setons whilst medical management is implemented. Always attempt to delineate the fistula anatomy, for abscesses and fistulae that have an intra abdominal source the use of barium and CT studies should show a track. For perianal fistulae surgeons should recall Goodsall's rule in relation to internal and external openings.

Answer 570

The spinal cord is approximately 45cm in men and 43cm in women. The denticulate ligament is a continuation of the pia mater (innermost covering of the spinal cord) which has intermittent lateral projections attaching the spinal cord to the dura mater. Spinal cord - Located in a canal within the vertebral column that affords it structural support. Rostrally it continues to the medulla oblongata of the brain and caudally it tapers at a level corresponding to the L1-2 interspace (in the adult), a central structure, the filum terminale anchors the cord to the first coccygeal vertebra. The spinal cord is characterised by cervico-lumbar enlargements and these, broadly speaking, are the sites which correspond to the brachial and lumbar plexuses respectively. There are some key points to note when considering the surgical anatomy of the spinal cord: * During foetal growth the spinal cord becomes shorter than the spinal canal, hence the adult site of cord termination at the L1-2 level. * Due to growth of the vertebral column the spine segmental levels may not always correspond to bony landmarks as they do in the cervical spine. * The spinal cord is incompletely divided into two symmetrical halves by a dorsal median sulcus and ventral median fissure. Grey matter surrounds a central canal that is continuous rostrally with the ventricular system of the CNS. * The grey matter is sub divided cytoarchitecturally into Rexeds laminae. * Afferent fibres entering through the dorsal roots usually terminate near their point of entry but may travel for varying distances in Lissauers tract. In this way they may establish synaptic connections over several levels * At the tip of the dorsal horn are afferents associated with nociceptive stimuli. The ventral horn contains neurones that innervate skeletal muscle. The key point to remember when revising CNS anatomy is to keep a clinical perspective in mind. So it is worth classifying the ways in which the spinal cord may become injured. These include: Trauma either direct or as a result of disc protrusion Neoplasia either by direct invasion (rare) or as a result of pathological vertebral fracture Inflammatory diseases such as Rheumatoid disease, or OA (formation of osteophytes compressing nerve roots etc. Vascular either as a result of stroke (rare in cord) or as complication of aortic dissection Infection historically diseases such as TB, epidural abscesses. The anatomy of the cord will, to an extent dictate the clinical presentation. Some points/ conditions to remember: Brown- Sequard syndrome-Hemisection of the cord producing ipsilateral loss of proprioception and upper motor neurone signs, plus contralateral loss of pain and temperature sensation. The explanation of this is that the fibres decussate at different levels. Lesions below L1 will tend to present with lower motor neurone signs

Answer 571

A knee injury in the footballer with a positive valgus stress test is usually associated with MCL injury. Knee collateral ligament Anatomy The tibial collateral ligament is a broad, flat band. Its upper end has an extensive attachment to the medial epicondyle of the femur with some fibres projecting onto the adductor magnus tendon. The ligament passes downwards and forwards to the medial side of the tibia. The deepest fibres are fused with the medial meniscus. The fibular collateral ligament is round and cord like and stands clear of the thin, lateral part of the fibrous capsule. It is enclosed within the fascia lata. It passes from the lateral epicondyle of the femur to the head of the fibula in front of its highest point and splits the tendon of biceps femoris. On the lateral side of the joint the fibres are short and weak and bridge the interval between the femoral and tibial condyles. The popliteus tendon intervenes between the lateral meniscus and the capsule. The tibial and fibular collateral ligaments prevent disruption of the joint at the sides. They are most tightly stretched in extension, and then their direction- the fibular ligament downwards and backwards, the tibial downwards and forwards- prevents rotation of the tibia laterally or the femur medially. Rotation may be demonstrated in the flexed knee. Injury The collateral ligaments are commonly injured, the medial is most often affected. It requires a significant force such as sporting tackle or motor vehicle to strike the side of the leg. Associated injuries to both the tibial plateau or menisci are not uncommon. Grading and treatment Grade of injury Features Treatment 1 Minor tearing of ligament fibres Negative instability tests Conservative (analgesia and physiotherapy) 2 Ligament laxity (seen with knee in 30o flexion) Knee stable when joint extended Usually splinting or casting for 4-6 weeks 3 Ligament completely torn Joint instability Surgical ligament reconstruction

Answer 572

The choroid plexus lies in all ventricles. Cerebrospinal fluid The CSF fills the space between the arachnoid mater and pia mater (covering surface of the brain). The total volume of CSF in the brain is approximately 150ml. Approximately 500 ml is produced by the ependymal cells in the choroid plexus (70%), or blood vessels (30%). It is reabsorbed via the arachnoid granulations which project into the venous sinuses. Circulation 1. Lateral ventricles (via foramen of Munro) 2. 3rd ventricle 3. Cerebral aqueduct (aqueduct of Sylvius) 4. 4th ventricle 5. Subarachnoid space (via foramina of Magendie and Luschka) 6. Reabsorbed into the venous system via arachnoid granulations into superior sagittal sinus Composition Glucose: 50-80mg/dl Protein: 15-40 mg/dl Red blood cells: Nil White blood cells: 0-3 cells/ mm3

Answer 573

Fresh blood is the fluid of choice when large volume blood loss complicates trauma. Mortality is doubled when blood >3 weeks old is used. Trauma management The cornerstone of trauma management is embodied in the principles of ATLS. Following trauma there is a trimodal death distribution: Immediately following injury. Typically as result of brain or high spinal injuries, cardiac or great vessel damage. Salvage rate is low. In early hours following injury. In this group deaths are due to phenomena such as splenic rupture, sub dural haematomas and haemopneumothoraces In the days following injury. Usually due to sepsis or multi organ failure. Aspects of trauma management ABCDE approach. Tension pneumothoraces will deteriorate with vigorous ventilation attempts. External haemorrhage is managed as part of the primary survey. As a rule tourniquets should not be used. Blind application of clamps will tend to damage surrounding structures and packing is the preferred method of haemorrhage control. Urinary catheters and naso gastric tubes may need inserting. Be wary of basal skull fractures and urethral injuries. Patients with head and neck trauma should be assumed to have a cervical spine injury until proven otherwise. Thoracic injuries Simple pneumothorax Mediastinal traversing wounds Tracheobronchial tree injury Haemothorax Blunt cardiac injury Diaphragmatic injury Aortic disruption Pulmonary contusion Management of thoracic trauma Simple pneumothorax insert chest drain. Aspiration is risky in trauma as pneumothorax may be from lung laceration and convert to tension pneumothorax. Mediastinal traversing wounds These result from situations like stabbings. Exit and entry wounds in separate hemithoraces. The presence of a mediastinal haematoma indicates the likelihood of a great vessel injury. All patients should undergo CT angiogram and oesophageal contrast swallow. Indications for thoracotomy are largely related to blood loss and will be addressed below. Tracheobronchial tree injury Unusual injuries. In blunt trauma most injuries occur within 4cm of the carina. Features suggesting this injury include haemoptysis and surgical emphysema. These injuries have a very large air leak and may have tension pneumothorax. Haemothorax Usually caused by laceration of lung vessel or internal mammary artery by rib fracture. Patients should all have a wide bore 36F chest drain. Indications for thoracotomy include loss of more than 1.5L blood initially or ongoing losses of >200ml per hour for >2 hours. Cardiac contusions Usually cardiac arrhythmias, often overlying sternal fracture. Perform echocardiography to exclude pericardial effusions and tamponade. Risk of arrhythmias falls after 24 hours. Diaphragmatic injury Usually left sided. Direct surgical repair is performed. Traumatic aortic disruption Commonest cause of death after RTA or falls. Usually incomplete laceration near ligamentum arteriosum. All survivors will have contained haematoma. Only 1-2% of patients with this injury will have a normal chest x-ray. Pulmonary contusion Common and lethal. Insidious onset. Early intubation and ventilation. Abdominal trauma Deceleration injuries are common. In blunt trauma requiring laparotomy the spleen is most commonly injured (40%) Stab wounds traverse structures most commonly liver (40%) Gunshot wounds have variable effects depending upon bullet type. Small bowel is most commonly injured (50%) Patients with stab wounds and no peritoneal signs up to 25% will not enter the peritoneal cavity Blood at urethral meatus suggests a urethral tear High riding prostate on PR = urethral disruption Mechanical testing for pelvic stability should only be performed once Investigations in abdominal trauma Diagnostic Peritoneal Lavage Abdominal CT scan USS Indication Document bleeding if hypotensive Document organ injury if normotensive Document fluid if hypotensive Advantages Early diagnosis and sensitive; 98% accurate Most specific for localising injury; 92 to 98% accurate Early diagnosis, non invasive and repeatable; 86 to 95% accurate Disadvantages Invasive and may miss retroperitoneal and diaphragmatic injury Location of scanner away from facilities, time taken for reporting, need for contrast Operator dependent and may miss retroperitoneal injury Amylase may be normal following pancreatic trauma Urethrography if suspected urethral injury

Answer 574

Aortic dissection is associated with the 3rd trimester of pregnancy, connective tissue disorders (Marfan's, Ehlers- Danlos) and bicuspid valve. Patients may complain of a tearing chest pain or syncope. Clinically they may be hypertensive. The right coronary artery may become involved in the dissection, causing myocardial infarct in up to 2% cases (hence ST elevation in the inferior leads). An aortic regurgitant murmur may be auscultated. Chest pain in pregnancy Aortic dissection Predisposing factors in pregnancy are hypertension, congenital heart disease and Marfan's syndrome Mainly Stanford type A dissections Sudden tearing chest pain, transient syncope Patient may be cold and clammy, hypertensive and have an aortic regurgitation murmur Involvement of the right coronary artery may cause inferior myocardial infarction Surgical management Gestational timeframe Management < 28/40 Aortic repair with the fetus kept in utero 28-32/40 Dependent on fetal condition > 32/40 Primary Cesarean section followed by aortic repair at the same operation Mitral stenosis Most cases associated with rheumatic heart disease Becoming less common in British women; suspect in women who have moved recently to the country Commonest cardiac condition in pregnancy Commonly associated with mortality Valve surgery; balloon valvuloplasty preferable Pulmonary embolism Leading cause of mortality in pregnancy Half dose scintigraphy; CT chest if underlying lung disease, should aid diagnosis Treatment with low molecular weight heparin throughout pregnancy and 4-6 weeks after childbirth Warfarin is contra indicated in pregnancy (though may be continued in women with mechanical heart valves due to the significant risk of thromboembolism) References 1. Bates S.M. and Ginsberg J.S. How we manage venous thromboembolism during pregnancy. Blood 2002 (100): 3470-3478. 2. Scarsbrook A.Fand Gleeson V. Investigating suspected pulmonary embolism in pregnancy. BMJ 2007 (326) : 1135 doi: 10.1136/bmj.7399.1135. 3. Morley C. A. and Lim B. A. Lesson of the Week: The risks of delay in diagnosis of breathlessness in pregnancy. BMJ 1995 (311) : 1083.

Answer 575

5 Flurouracil Drugs causing SIADH: ABCD A nalgesics: opioids, NSAIDs B arbiturates C yclophosphamide/ Chlorpromazine/ Carbamazepine D iuretic (thiazides) Hyponatraemia This is commonly tested in the MRCS (despite most surgeons automatically seeking medical advice if this occurs!). The most common cause in surgery is the over administration of 5% dextrose. Hyponatraemia may be caused by water excess or sodium depletion. Causes of pseudohyponatraemia include hyperlipidaemia (increase in serum volume) or a taking blood from a drip arm. Urinary sodium and osmolarity levels aid making a diagnosis. Classification Urinary sodium > 20 mmol/l Sodium depletion, renal loss Patient often hypovolaemic Diuretics (thiazides) Addison's Diuretic stage of renal failure SIADH (serum osmolality low, urine osmolality high, urine Na high) Patient often euvolaemic Mnemonic: Syndrome of INAPPropriate Anti-Diuretic Hormone: In creased Na (sodium) PP (urine) Urinary sodium < 20 mmol/l Sodium depletion, extra-renal loss Diarrhoea, vomiting, sweating Burns, adenoma of rectum (if villous lesion and large) Water excess (patient often hypervolaemic and oedematous) Secondary hyperaldosteronism: CCF, cirrhosis Reduced GFR: renal failure IV dextrose, psychogenic polydipsia Management Symptomatic Hyponatremia : Acute hyponatraemia with Na <120: immediate therapy. Central Pontine Myelinolisis, may occur from overly rapid correction of serum sodium. Aim to correct until the Na is > 125 at a rate of 1 mEq/h. Normal saline with frusemide is an alternative method. The sodium requirement can be calculated as follows : (125 - serum sodium) x 0.6 x body weight = required mEq of sodium

Answer 576

Feltys syndrome: Rheumatoid disease Splenomegaly Neutropenia Feltys syndrome is associated with rheumatoid disease. Individuals with long standing Crohns disease are at risk of gallstones because of impairment of the enterohepatic recycling of bile salts. Formation of entero-enteric fistulation may produce malabsorption. Amyloidosis may complicate chronic inflammatory states. Crohns disease Crohns disease is a chronic transmural inflammation of a segment(s) of the gastrointestinal tract and may be associated with extra intestinal manifestations. Frequent disease patterns observed include ileal, ileocolic and colonic disease. Peri-anal disease may occur in association with any of these. The disease is often discontinuous in its distribution. Inflammation may cause ulceration, fissures, fistulas and fibrosis with stricturing. Histology reveals a chronic inflammatory infiltrate that is usually patchy and transmural. Ulcerative colitis Vs Crohns Crohn's disease Ulcerative colitis Distribution Mouth to anus Rectum and colon Macroscopic changes Cobblestone appearance, apthoid ulceration Contact bleeding Depth of disease Transmural inflammation Superficial inflammation Distribution pattern Patchy Continuous Histological features Granulomas (non caseating epithelioid cell aggregates with Langhans' giant cells) Crypt abscesses, Inflammatory cells in the lamina propria Extraintestinal manifestations of Crohns Related to disease extent Unrelated to disease extent Aphthous ulcers (10%) Sacroiliiitis (10-15%) Erythema nodosum (5-10%) Ankylosing spondylitis (1-2%) Pyoderma gangrenosum (0.5%) Primary sclerosing cholangitis (Rare) Acute arthropathy (6-12%) Gallstones (up to 30%) Ocular complications (up to 10%) Renal calculi (up to 10%) Diarrhoea in Crohns Diarrhoea in Crohns may be multifactorial since actual inflammation of the colon is not common. Causes therefore include the following: Bile salt diarrhoea secondary to terminal ileal disease Entero-colic fistula Short bowel due to multiple resections Bacterial overgrowth Surgical interventions in Crohns disease The commonest disease pattern in Crohns is stricturing terminal ileal disease and this often culminates in an ileocaecal resection. Other procedures performed include segmental small bowel resections and stricturoplasty. Colonic involvement in patients with Crohns is not common and, where found, distribution is often segmental. However, despite this distribution segmental resections of the colon in patients with Crohns disease are generally not advocated because the recurrence rate in the remaining colon is extremely high. As a result, the standard options of colonic surgery in Crohns patients are generally; sub total colectomy, panproctocolectomy and staged sub total colectomy and proctectomy. Restorative procedures such as ileoanal pouch have no role in therapy. Crohns disease is notorious for the developmental of intestinal fistulae; these may form between the rectum and skin (peri anal) or the small bowel and skin. Fistulation between loops of bowel may also occur and result in bacterial overgrowth and malabsorption. Management of enterocutaneous fistulae involves controlling sepsis, optimising nutrition, imaging the disease and planning definitive surgical management.

Answer 577

The Klippel-Trenaunay vein is a large, lateral, superficial vein sometimes seen at birth. This vein begins in the foot or the lower leg and travels proximally until it enters the thigh or the gluteal area. Otherwise, varicosities may not be clinically evident until the child begins to ambulate. Varicosities may be extensive, though they often spare the saphenous distribution. They are seen below the knee, laterally above the knee, and occasionally in the pelvic region. Varicosities may affect the superficial, deep, and perforating venous systems. Flow rates through the vascular anomalies are low flow rates in contrast to Parkes Weber syndrome where high flow rates are seen. Surgical exploration has demonstrated atresia and agenesis of deep veins, compression due to fibrous bands, aberrant arteries, abnormal muscles, or venous sheaths. Rarely, varicosities have been found in the bladder, the colon, and the pulmonary vessels Klippel-Trenaunay syndrome is a rare condition that affects the development of blood vessels, soft tissues, and bones. The disorder has three characteristic features: a red birthmark called a port-wine stain, abnormal overgrowth of soft tissues and bones, and vein malformations12 The cause of Klippel-Trenaunay syndrome is not well understood, but it is not directly inherited from parents. It may be related to problems with how the blood vessel system develops during pregnancy23 The symptoms of Klippel-Trenaunay syndrome vary from person to person, but they usually affect only one limb, most often the leg. The port-wine stain is often the first sign of the condition, and it may cover a large area of the skin. The affected limb may also be longer and wider than the other, and have varicose veins or lymphatic malformations12 There is no cure for Klippel-Trenaunay syndrome, but treatments can help manage the symptoms and prevent complications. These may include compression garments, laser therapy, surgery, or medication24

Answer 578

Rhabdomyosarcomas as one of the more common malignant solid tumours in children (though all are rare). They have an aggressive behavior pattern and metastases are common. Teratomas are nearly always benign in younger children. Seminomas are very rare indeed. Malignant fibrous histiocytomas are almost never found in this location. Sarcomas Malignant tumours of mesenchymal origin Types May be either bone or soft tissue in origin. Bone sarcoma include: Osteosarcoma Ewings sarcoma (although non bony sites recognised) Chondrosarcoma - originate from Chondrocytes Soft tissue sarcoma are a far more heterogeneous group and include: Liposarcoma-adipocytes Rhabdomyosarcoma-striated muscle Leiomyosarcoma-smooth muscle Synovial sarcomas- close to joints (cell of origin not known but not synovium) Malignant fibrous histiocytoma is now referred to as undifferentiated pleomorphic sarcoma. Careful histological assessment of lesions now allows more accurate categorisation of sarcoma subtypes than was previously possible. Features Certain features of a mass or swelling should raise suspicion for a sarcoma these include: Large >5cm soft tissue mass Deep tissue location or intra muscular location Rapid growth Painful lump Assessment Imaging of suspicious masses should utilise a combination of MRI, CT and USS. Blind biopsy should not be performed prior to imaging and where required should be done in such a way that the biopsy tract can be subsequently included in any resection. Ewings sarcoma Commoner in males Incidence of 0.3 / 1, 000, 000 Onset typically between 10 and 20 years of age Location by femoral diaphysis is commonest site Histologically it is a small round tumour Blood borne metastasis is common and chemotherapy is often combined with surgery Osteosarcoma Mesenchymal cells with osteoblastic differentiation 20% of all primary bone tumours Incidence of 5 per 1,000,000 Peak age 15-30, commoner in males Limb preserving surgery may be possible and many patients will receive chemotherapy Liposarcoma Malignancy of adipocytes Rare, approximately 2.5 per 1,000,000. They are the most common soft tissue sarcoma Typically located in deep locations such as retroperitoneum Affect older age group usually >40 years of age May be well differentiated and thus slow growing although may undergo de-differentiation and disease progression Many tumours will have a pseudocapsule that can misleadingly allow surgeons to feel that they can 'shell out' these lesions. In reality, tumour may invade at the edge of the pseudocapsule and result in local recurrence if this strategy is adopted Usually resistant to radiotherapy, although this is often used in a palliative setting Malignant Fibrous Histiocytoma Tumour with large number of histiocytes Also described as undifferentiated pleomorphic sarcoma NOS (i.e. Cell of origin is not known) Four major subtypes are recognised: storiform-pleomorphic (70% cases), myxoid (less aggressive), giant cell and inflammatory Treatment is usually with surgical resection and adjuvant radiotherapy as this reduces the likelihood of local recurrence

Answer 579

The sphenoidal sinus drains into the sphenoethmoidal recess and is likely to be affected. The other sinuses drain into the superior, middle and inferior meatus. Nasal cavity There are two nasal cavities separated by the median nasal septum. This structure consists of septal cartilage and two bony parts: the vomer and the perpendicular plate of the ethmoid bone. Each cavity is approximately 5cm high and 7cm long, from the nares anteriorly to the choanae posteriorly. The lateral walls of each cavity are mainly made up of the maxilla. However, the lacrimal, ethmoid and palatine bones also contribute. The ethmoid gives rise to the two upper protrusions from the lateral walls, the superior and middle conchae. The inferior concha is a separate bone. Above the superior concha lies the sphenoethmoidal recess. The spaces inferior to conchae are the superior, middle and inferior meatus. The structures draining into each space are shown below: Sphenoethmoidal recess Sphenoidal sinus Superior meatus Posterior ethmoidal sinus Middle meatus Frontal sinus, maxillary sinus ,anterior and middle ethmoidal sinus Inferior meatus Nasolacrimal duct The main arterial supply to the septum and lateral walls is the sphenopalatine artery, a branch of the maxillary artery. The olfactory nerve conveys special sensation. Common sensation from the nasal mucosa is conveyed by the trigeminal nerve.

Answer 580

The deep posterior compartment lies anterior to soleus. The sural nerve is superficially sited and therefore not contained within it. Lower limb- Muscular compartments Anterior compartment Muscle Nerve Action Tibialis anterior Deep peroneal nerve Dorsiflexes ankle joint, inverts foot Extensor digitorum longus Deep peroneal nerve Extends lateral four toes, dorsiflexes ankle joint Peroneus tertius Deep peroneal nerve Dorsiflexes ankle, everts foot Extensor hallucis longus Deep peroneal nerve Dorsiflexes ankle joint, extends big toe Peroneal compartment Muscle Nerve Action Peroneus longus Superficial peroneal nerve Everts foot, assists in plantar flexion Peroneus brevis Superficial peroneal nerve Plantar flexes the ankle joint Superficial posterior compartment Nerve Action Gastrocnemius Tibial nerve Plantar flexes the foot, may also flex the knee Soleus Tibial nerve Plantar flexor Deep posterior compartment Muscle Nerve Action Flexor digitorum longus Tibial Flexes the lateral four toes Flexor hallucis longus Tibial Flexes the great toe Tibialis posterior Tibial Plantar flexor, inverts the foot

Answer 581

It's cardiac effects are mediated via β 1 receptors. The coronary arteries which have β 2 receptors are unaffected. Adrenaline Fight or Flight response - Catecholamine (phenylalanine and tyrosine) - Neurotransmitter and hormone - Released by the adrenal glands - Effects on α 1 and 2, β 1 and 2 receptors - Effect on β 2 receptors in skeletal muscle vessels-causing vasodilation - Increase cardiac output and total peripheral resistance - Vasoconstriction in the skin and kidneys causing a narrow pulse pressure Actions α adrenergic receptors: Inhibits insulin secretion by the pancreas Stimulates glycogenolysis in the liver and muscle Stimulates glycolysis in muscle β adrenergic receptors: Stimulates glucagon secretion in the pancreas Stimulates ACTH Stimulates lipolysis by adipose tissue

Answer 582

The likely diagnosis is one of a familial cancer syndrome and now that he has developed a colonic cancer the safest operative strategy is a total colectomy and end ileostomy. Polyposis syndromes Syndrome Genetic defect Features Screening and management Associated disorders Familial adenomatous polyposis Mutation of APC gene (80%) cases, dominant Typically over 100 colonic adenomas Cancer risk of 100% 20% are new mutations If known to be at risk then predictive genetic testing as teenager Annual flexible sigmoidoscopy from 15 years If no polyps found then 5 yearly colonoscopy started at age 20 Polyps found = resectional surgery (resection and pouch Vs sub total colectomy and IRA) Gastric fundal polyps (50%). Duodenal polyps 90%. If severe duodenal polyposis cancer risk of 30% at 10 years. Abdominal desmoid tumours. MYH associated polyposis Biallelic mutation of mut Y human homologue (MYH) on chromosome 1p, recessive Multiple colonic polyps Later onset right sided cancers more common than in FAP 100% cancer risk by age 60 Once identified resection and ileoanal pouch reconstruction is recommended Attenuated phenotype - regular colonoscopy Duodenal polyposis in 30% Associated with increased risk of breast cancer (self examination) Peutz -Jeghers syndrome STK11 (LKB1) mutation on chromosome 19 in some (but not all) cases, dominant Multiple benign intestinal hamartomas Episodic obstruction and intussceception Increased risk of GI cancers (colorectal cancer 20%, gastric 5%) Increased risk of breast, ovarian, cervical pancreatic and testicular cancers Annual examination Pan intestinal endoscopy every 2-3 years Malignancies at other sites Classical pigmentation pattern Cowden disease Mutation of PTEN gene on chromosome 10q22, dominant Macrocephaly Multiple intestinal hamartomas Multiple trichilemmomas 89% risk of cancer at any site 16% risk of colorectal cancer Targeted individualised screening Breast cancer (81% risk) Thyroid cancer and non toxic goitre Uterine cancer HNPCC (Lynch syndrome) Germline mutations of DNA mismatch repair genes Colo rectal cancer 30-70% Endometrial cancer 30-70% Gastric cancer 5-10% Scanty colonic polyps may be present Colonic tumours likely to be right sided and mucinous Colonoscopy every 1-2 years from age 25 Consideration of prophylactic surgery Extra colonic surveillance recommended Extra colonic cancers

Answer 583

The resection of the proximal stomach which is performed in these cases together with the gastric mobilisation required results in the division of all vessels except the right gastro-epiploic artery which then supplies the gastric remnant. It is this precarious supply that can result in conduit necrosis. Stomach anatomy The abdominal oesophagus enters the stomach through the cardiac orifice, it tends to lie around the level of T11 although this can vary considerably. The pyloric orifice tends to lie on a level of L1 (the transpyloric plane) although this, too, can vary. Structurally, the stomach comprises fundic, body and pyloric regions. The body is comprises most of the gastric surface area. The anterior and posterior surfaces of the stomach unite at the greater and lesser curvatures. The peritoneum on the anterior and posterior surfaces of the stomach unites at the greater curvature to form the gastrosplenic ligament above and the anterior layer of the greater omentum below. There are three muscular layers to the stomach wall; circular muscle fibres, longitudinal fibres and oblique fibres. Blood supply Left gastric artery Short gastric vessels Gastro-epiploic arteries The veins draining the stomach accompany the arteries. The right and left gastric veins drain directly into the portal vein. The right gastro-epiploic vein either drains into the SMV or middle colic vein. The left gastro-epiploic and short gastric veins drain into the splenic vein. Innervation Sympathetic nerves arise from the coeliac ganglia with post ganglionic fibres accompanying the arteries. Parasympathetic innervation is from the anterior and posterior vagal trunks

Answer 584

D- Hyponatraemia There are many adverse effects associated with excess glucocorticoids. Thinning of the skin, osteonecrosis and osteoporosis are all common. Steroids are associated with retention of sodium and water. Potassium loss may occur and hypokalaemic alkalosis has been reported. Cortisol Glucocorticoid Released by zona fasiculata of the adrenal gland 90% protein bound; 10% active Circadian rhythm: High in the mornings Negative feedback via ACTH Actions Glycogenolysis Gluconeogenesis Protein catabolism Lipolysis Stress response Anti-inflammatory Decrease protein in bones Increase gastric acid Increases neutrophils/platelets/red blood cells Inhibits fibroblastic activity

Answer 585

The aorta may be injured in deceleration accidents. In the setting of deceleration injury, chest pain and mediastinal widening the most likely problem is aortic rupture. This will typically occur distal to the left subclavian artery. Rupture of the proximal aorta may occur. However, survival is unlikely. It is important to note that the question uses the term Most likely injury as this is the component that distinguishes an ascending rupture from a descending rupture. Thoracic aorta rupture Mechanism of injury: Decelerating force i.e. RTA, fall from a great height Most people die at scene Survivors may have an incomplete laceration at the ligamentum arteriosum of the aorta. Clinical features Contained haematoma: persistent hypotension Detected mainly by history, CXR changes CXR changes Widened mediastinum Trachea/Oesophagus to right Depression of left main stem bronchus Widened paratracheal stripe/paraspinal interfaces Space between aorta and pulmonary artery obliterated Rib fracture/left haemothorax Diagnosis Angiography, usually CT aortogram. Treatment Repair or replacement. Ideally they should undergo endovascular repair.

Answer 586

The most likely injury is to the superior laryngeal nerve which innervates the cricothyroid muscle. Since this tenses the vocal cords, singing high notes becomes a problem. Voice production There are 2 main nerves involved: Superior laryngeal nerve (SLN) Innervates the cricothyroid muscle Since the cricothyroid muscle is involved in adjusting the tension of the vocal fold for high notes during singing, SLN paresis and paralysis result in: a. Abnormalities in pitch b. Inability to sing with smooth change to each higher note (glissando or pitch glide) Recurrent laryngeal nerve (RLN)/Inferior laryngeal nerve Innervates intrinsic larynx muscles a. Opening vocal folds (as in breathing, coughing) b. Closing vocal folds for vocal fold vibration during voice use c. Closing vocal folds during swallowing

Answer 587

The ductus arteriosus connects the pulmonary artery to the first part of the descending aorta. The ductus venosus connects the umbilical vein to the inferior vena cava and bypasses the liver. The volume transferred by this route decreases with gestation. Persistent patent ductus arteriosus is treated with NSAIDS in most cases. Ductus arteriosus The ductus arteriosus is formed from the left 6th aortic arch during embryonic development and attaches to the final part of the aortic arch (the isthmus of aorta) and the first part of the pulmonary artery. It serves to allow blood in the developing foetus to bypass the lungs. It usually closes soon after birth. Should it not do so, it can be stimulated to close by administration of indomethacin.

Answer 588

Mnemonic: SALTER S (Type 1): Straight through the growth plate A (Type 2): Above - through growth plate and Above involving the metaphysis L (Type 3): Lower -through growth plate and beLow involving the epiphysis T (Type 4):Through - Through both metaphysis, epiphysis and growth plate E (Type 5): Everything - Crush / compression injury R (Type 5): Ruined As recommended by one of our users Salter Harris injury types 1 and 5 (transverse fracture through growth plate Vs. Compression fracture) may mimic each other radiologically. Type 5 injuries have the worst outcomes. Radiological signs of type 5 injuries are subtle and may include narrowing of the growth plate. Epiphyseal fractures Fractures involving the growth plate in children are classified using the Salter - Harris system. There are 5 main types. Salter Harris Classification Type Description Type 1 Transverse fracture through the growth plate Type 2 Fracture through the growth plate to the metaphysis (commonest type) Type 3 Fracture through the growth plate and the epiphysis with metaphysis spared Type 4 Fracture involving the growth plate, metaphysis and epiphysis Type 5 Compression fracture of the growth plate (worst outcome) Management Non displaced type 1 injuries can generally be managed conservatively. Unstable or more extensive injuries will usually require surgical reduction and/ or fixation, as proper alignment is crucial.

Answer 589

Pancreatic cancer has a poor prognosis and most cases have metastatic disease at presentation. There is no role in pancreatic cancer for liver resection together with pancreatic surgery as there is no survival benefit. Most centres will offer palliative chemotherapy which has improved both longevity and quality of life. Pancreatic cancer - Adenocarcinoma Risk factors: Smoking, diabetes, adenoma, familial adenomatous polyposis Mainly occur in the head of the pancreas (70%) Spread locally and metastasizes to the liver Carcinoma of the pancreas should be differentiated from other periampullary tumours with better prognosis Clinical features Weight loss Painless jaundice Epigastric discomfort (pain usually due to invasion of the coeliac plexus is a late feature) Pancreatitis Trousseau's sign: migratory superficial thrombophlebitis Investigations USS: May miss small lesions CT Scanning (pancreatic protocol). If unresectable on CT then no further staging needed PET/CT for those with operable disease on CT alone ERCP/ MRI for bile duct assessment Staging laparoscopy to exclude peritoneal disease Management Head of pancreas: Whipple's resection (SE dumping and ulcers). Newer techniques include pylorus preservation and SMA/ SMV resection Carcinoma body and tail: poor prognosis, distal pancreatectomy, if operable Usually adjuvent chemotherapy for resectable disease ERCP and stent for jaundice and palliation Surgical bypass may be needed for duodenal obstruction

Answer 590

Tuberous sclerosis Tuberous sclerosis (TS) is a genetic condition of autosomal dominant inheritance. Like neurofibromatosis, the majority of features seen in TS are neuro-cutaneous Cutaneous features depigmented 'ash-leaf' spots which fluoresce under UV light roughened patches of skin over lumbar spine (Shagreen patches) adenoma sebaceum: butterfly distribution over nose fibromata beneath nails (subungual fibromata) café-au-lait spots* may be seen Neurological features developmental delay epilepsy (infantile spasms or partial) intellectual impairment Also retinal hamartomas: dense white areas on retina (phakomata) rhabdomyomas of the heart gliomatous changes can occur in the brain lesions polycystic kidneys, renal angiomyolipomata *these of course are more commonly associated with neurofibromatosis. However a 1998 study of 106 children with TS found café-au-lait spots in 28% of patients

Answer 591

Preload is the same as end diastolic volume. When it is increased slightly there is an associated increase in cardiac output (Frank Starling principle). When it is markedly increased e.g. over 250ml then cardiac output falls. Cardiac physiology - The heart has four chambers ejecting blood into both low pressure and high pressure systems. The pumps generate pressures of between 0-25mmHg on the right side and 0-120 mmHg on the left. At rest diastole comprises 2/3 of the cardiac cycle. The product of the frequency of heart rate and stroke volume combine to give the cardiac output which is typically 5-6L per minute. Detailed descriptions of the various waveforms are often not a feature of MRCS A (although they are on the syllabus). However, they are a very popular topic for surgical physiology in the MRCS B exam. Electrical properties Intrinsic myogenic rhythm within cardiac myocytes means that even the denervated heart is capable of contraction. In the normal situation the cardiac impulse is generated in the sino atrial node in the right atrium and conveyed to the ventricles via the atrioventricular node. The sino atrial node is also capable of spontaneous discharge and in the absence of background vagal tone will typically discharge around 100x per minute. Hence the higher resting heart rate found in cardiac transplant cases. In the SA and AV nodes the resting membrane potential is lower than in surrounding cardiac cells and will slowly depolarise from -70mV to around -50mV at which point an action potential is generated. Differences in the depolarisation slopes between SA and AV nodes help to explain why the SA node will depolarise first. The cells have a refractory period during which they cannot be re-stimulated and this period allows for adequate ventricular filling. In pathological tachycardic states this time period is overridden and inadequate ventricular filling may then occur, cardiac output falls and syncope may ensue. Parasympathetic fibres project to the heart via the vagus and will release acetylcholine. Sympathetic fibres release nor adrenaline and circulating adrenaline comes from the adrenal medulla. Noradrenaline binds to β 1 receptors in the SA node and increases the rate of pacemaker potential depolarisation. Mid diastole: AV valves open. Ventricles hold 80% of final volume. Outflow valves shut. Aortic pressure is high. Late diastole: Atria contract. Ventricles receive 20% to complete filling. Typical end diastolic volume 130-160ml. Early systole: AV valves shut. Ventricular pressure rises. Isovolumetric ventricular contraction. AV Valves bulge into atria (c-wave). Aortic and pulmonary pressure exceeded- blood is ejected. Shortening of ventricles pulls atria downwards and drops intra atrial pressure (x-descent). Late systole: Ventricular muscles relax and ventricular pressures drop. Although ventricular pressure drops the aortic pressure remains constant owing to peripheral vascular resistance and elastic property of the aorta. Brief period of retrograde flow that occurs in aortic recoil shuts the aortic valve. Ventricles will contain 60ml end systolic volume. The average stroke volume is 70ml (i.e. Volume ejected). Early diastole: All valves are closed. Isovolumetric ventricular relaxation occurs. Pressure wave associated with closure of the aortic valve increases aortic pressure. The pressure dip before this rise can be seen on arterial waveforms and is called the incisura. During systole the atrial pressure increases such that it is now above zero (v- wave). Eventually atrial pressure exceed ventricular pressure and AV valves open - atria empty passively into ventricles and atrial pressure falls (y -descent ) The negative atrial pressures are of clinical importance as they can allow air embolization to occur if the neck veins are exposed to air. This patient positioning is important in head and neck surgery to avoid this occurrence if veins are inadvertently cut, or during CVP line insertion. Mechanical properties Preload = end diastolic volume Afterload = aortic pressure It is important to understand the principles of Laplace's law in surgery. It states that for hollow organs with a circular cross section, the total circumferential wall tension depends upon the circumference of the wall, multiplied by the thickness of the wall and on the wall tension. The total luminal pressure depends upon the cross sectional area of the lumen and the transmural pressure. Transmural pressure is the internal pressure minus external pressure and at equilibrium the total pressure must counterbalance each other. In terms of cardiac physiology the law explains that the rise in ventricular pressure that occurs during the ejection phase is due to physical change in heart size. It also explains why a dilated diseased heart will have impaired systolic function. Starlings law Increase in end diastolic volume will produce larger stroke volume. This occurs up to a point beyond which cardiac fibres are excessively stretched and stroke volume will fall once more. It is important for the regulation of cardiac output in cardiac transplant patients who need to increase their cardiac output. Baroreceptor reflexes Baroreceptors located in aortic arch and carotid sinus. Aortic baroreceptor impulses travel via the vagus and from the carotid via the glossopharyngeal nerve. They are stimulated by arterial stretch. Even at normal blood pressures they are tonically active. Increase in baroreceptor discharge causes: *Increased parasympathetic discharge to the SA node. *Decreased sympathetic discharge to ventricular muscle causing decreased contractility and fall in stroke volume. *Decreased sympathetic discharge to venous system causing increased compliance. *Decreased peripheral arterial vascular resistance Atrial stretch receptors Located in atria at junction between pulmonary veins and vena cava. Stimulated by atrial stretch and are thus low pressure sensors. Increased blood volume will cause increased parasympathetic activity. Very rapid infusion of blood will result in increase in heart rate mediated via atrial receptors: the Bainbridge reflex. Decreases in receptor stimulation results in increased sympathetic activity this will decrease renal blood flow-decreases GFR-decreases urinary sodium excretion-renin secretion by juxtaglomerular apparatus-Increase in angiotensin II. Increased atrial stretch will also result in increased release of atrial natriuretic peptide.

Answer 592

The posterior inferior cerebellar artery is the largest of the cerebellar arteries arising from the vertebral artery. The labyrinthine artery is long and slender and may arise from the lower part of the basilar artery. It accompanies the facial and vestibulocochlear nerves into the internal auditory meatus. The posterior cerebral artery is often larger than the superior cerebellar artery and it is separated from the vessel, near it's origin, by the oculomotor nerve. Arterial decompression is a well established therapy for trigeminal neuralgia. Circle of Willis The two internal carotid arteries and two vertebral arteries form an anastomosis known as the Circle of Willis on the inferior surface of the brain. Each half of the circle is formed by: 1. Anterior communicating artery 2. Anterior cerebral artery 3. Internal carotid artery 4. Posterior communicating artery 5. Posterior cerebral arteries and the termination of the basilar artery The circle and its branches supply; the corpus striatum, internal capsule, diencephalon and midbrain. Vertebral arteries Enter the cranial cavity via foramen magnum Lie in the subarachnoid space Ascend on anterior surface of medulla oblongata Unite to form the basilar artery at the base of the pons Branches: Posterior spinal artery Anterior spinal artery Posterior inferior cerebellar artery Basilar artery Branches: Anterior inferior cerebellar artery Labyrinthine artery Pontine arteries Superior cerebellar artery Posterior cerebral artery (at the point where it bifurcates) Internal carotid arteries Branches: Posterior communicating artery Anterior cerebral artery Middle cerebral artery Anterior choroid artery

Answer 593

Individuals with small carcinoids can be discharged (<2cm and limited to the appendix). Larger tumours should have a radioisotope scan. Where the resection margin is positive or where the isotope scan suggests lymphatic metastasis a right hemicolectomy should be performed. Carcinoid syndrome Carcinoid tumours secrete serotonin Originate in neuroendocrine cells mainly in the intestine (midgut-distal ileum/appendix) Can occur in the rectum, bronchi Hormonal symptoms mainly occur when disease spreads outside the bowel Clinical features Onset: insidious over many years Flushing face Palpitations Pulmonary valve stenosis and tricuspid regurgitation causing dyspnoea Asthma Severe diarrhoea (secretory, persists despite fasting) Investigation 5-HIAA in a 24-hour urine collection Somatostatin receptor scintigraphy CT scan Blood testing for chromogranin A Treatment Octreotide Surgical removal

Answer 594

The lateral aspect of the external nose is innervated by lateral nasal branches of the anterior ethmoidal nerve. The ethmoidal nerve is a branch of the nasociliary nerve which is one of the divisions of the trigeminal. Trigeminal nerve The trigeminal nerve is the main sensory nerve of the head. In addition to its major sensory role, it also innervates the muscles of mastication. Distribution of the trigeminal nerve Sensory Scalp Face Oral cavity (and teeth) Nose and sinuses Dura mater Motor Muscles of mastication Mylohyoid Anterior belly of digastric Tensor tympani Tensor palati Autonomic connections (ganglia) Ciliary Sphenopalatine Otic Submandibular Path Originates at the pons Sensory root forms the large, crescentic trigeminal ganglion within Meckel's cave, and contains the cell bodies of incoming sensory nerve fibres. Here the 3 branches exit. The motor root cell bodies are in the pons and the motor fibres are distributed via the mandibular nerve. The motor root is not part of the trigeminal ganglion. Branches of the trigeminal nerve Ophthalmic nerve Sensory only Maxillary nerve Sensory only Mandibular nerve Sensory and motor Sensory Ophthalmic Exits skull via the superior orbital fissure Sensation of: scalp and forehead, the upper eyelid, the conjunctiva and cornea of the eye, the nose (including the tip of the nose, except alae nasi), the nasal mucosa, the frontal sinuses, and parts of the meninges (the dura and blood vessels). Maxillary nerve Exit skull via the foramen rotundum Sensation: lower eyelid and cheek, the nares and upper lip, the upper teeth and gums, the nasal mucosa, the palate and roof of the pharynx, the maxillary, ethmoid and sphenoid sinuses, and parts of the meninges. Mandibular nerve Exit skull via the foramen ovale Sensation: lower lip, the lower teeth and gums, the chin and jaw (except the angle of the jaw), parts of the external ear, and parts of the meninges. Motor Distributed via the mandibular nerve. The following muscles of mastication are innervated: Masseter Temporalis Medial pterygoid Lateral pterygoid Other muscles innervated include: Tensor veli palatini Mylohyoid Anterior belly of digastric Tensor tympani

Answer 595

Ciclosporin- nephrotoxicity This patient is at risk of nephrotoxicity and should be referred to the renal team as soon as possible. Alopecia is associated with azathioprine and diabetes is associated with long term use. Organ transplantation: immunosuppressants A number of drugs are available which help to mitigate the processes resulting in acute rejection. Cyclosporin and tacrolimus are commonly used drugs. Example regime Initial: ciclosporin/tacrolimus with a monoclonal antibody Maintenance: ciclosporin/tacrolimus with MMF or sirolimus Add steroids if more than one steroid responsive acute rejection episode Ciclosporin Inhibits calcineurin, a phosphatase involved in T cell activation Nephrotoxic Monitor levels Azathioprine Metabolised to form 6 mercaptopurine which inhibits DNA synthesis and cell division Side effects include myelosupression, alopecia and nausea Tacrolimus Lower incidence of acute rejection compared to ciclosporin Also less hypertension and hyperlipidaemia However, high incidence of impaired glucose tolerance and diabetes Mycophenolate mofetil (MMF) Blocks purine synthesis by inhibition of IMPDH Therefore inhibits proliferation of B and T cells Side-effects: GI and marrow suppression Sirolimus (rapamycin) Blocks T cell proliferation by blocking the IL-2 receptor Can cause hyperlipidaemia Monoclonal antibodies Selective inhibitors of IL-2 receptor Daclizumab Basilximab

Answer 596

Brown -Sequard syndrome is caused by hemisection of the spinal cord. It may result from stab injuries or lateral vertebral fractures. It results in ipsilateral paralysis (pyramidal tract) , and also loss of proprioception and fine discrimination (dorsal columns). Pain and temperature sensation are lost on the contra-lateral side. This is because the fibres of the spinothalamic tract have decussated below the level of the cord transection. Spinal disorders Dorsal column lesion Loss vibration and proprioception Tabes dorsalis, SACD Spinothalamic tract lesion Loss of pain, sensation and temperature Central cord lesion Flaccid paralysis of the upper limbs Osteomyelitis Normally progressive Staph aureus in IVDU, normally cervical region affected Fungal infections in immunocompromised Thoracic region affected in TB Infarction spinal cord Dorsal column signs (loss of proprioception and fine discrimination) Cord compression UMN signs Malignancy Haematoma Fracture Brown-sequard syndrome Hemisection of the spinal cord Ipsilateral paralysis Ipsilateral loss of proprioception and fine discrimination Contralateral loss of pain and temperature Dermatomes C2 to C4 The C2 dermatome covers the occiput and the top part of the neck. C3 covers the lower part of the neck to the clavicle. C4 covers the area just below the clavicle. C5 to T1 Situated in the arms. C5 covers the lateral arm at and above the elbow. C6 covers the forearm and the radial (thumb) side of the hand. C7 is the middle finger, C8 is the medial aspect of the hand, and T1 covers the medial side of the forearm. T2 to T12 The thoracic covers the axillary and chest region. T3 to T12 covers the chest and back to the hip girdle. The nipples are situated in the middle of T4. T10 is situated at the umbilicus. T12 ends just above the hip girdle. L1 to L5 The cutaneous dermatome representing the hip girdle and groin area is innervated by L1 spinal cord. L2 and 3 cover the front part of the thighs. L4 and L5 cover medial and lateral aspects of the lower leg. S1 to S5 S1 covers the heel and the middle back of the leg. S2 covers the back of the thighs. S3 cover the medial side of the buttocks and S4-5 covers the perineal region. S5 is of course the lowest dermatome and represents the skin immediately at and adjacent to the anus. Myotomes Upper limb Elbow flexors/Biceps C5 Wrist extensors C6 Elbow extensors/Triceps C7 Long finger flexors C8 Small finger abductors T1 Lower limb Hip flexors (psoas) L1 and L2 Knee extensors (quadriceps) L3 Ankle dorsiflexors (tibialis anterior) L4 and L5 Toe extensors (hallucis longus) L 5 Ankle plantar flexors (gastrocnemius) S1 The anal sphincter is innervated by S2,3,4

Answer 597

The external jugular vein lies lateral (i.e. superficial) to the sternocleidomastoid. Sternocleidomastoid Anatomy Origin Rounded tendon attached to upper manubrium sterni and muscular head attached to medial third of the clavicle Insertion Mastoid process of the temporal bone and lateral area of the superior nuchal line of the occipital bone Innervation Spinal part of accessory nerve and anterior rami of C2 and C3 (proprioception) Action Both: extend the head at atlanto-occipital joint and flex the cervical vertebral column. Accessory muscles of inspiration. Single: lateral flexion of neck, rotates head so face looks upward to the opposite side Sternocleidomastoid divides the anterior and posterior triangles of the neck.

Answer 598

Erbs Palsy C5, C6 lesion The features include: Waiter's tip position Loss of shoulder abduction (deltoid and supraspinatus paralysis) Loss of external rotation of the shoulder (paralysis of infraspinatus) Loss of elbow flexion (paralysis of biceps, brachialis and brachioradialis) Loss of forearm supination (paralysis of Biceps) The motorcyclist has had an Erb's palsy (C5, C6 root lesion). This is commonly known to be associated with birth injury when a baby has a shoulder dystocia. Brachial plexus The brachial plexus extends from the neck to the axilla. It is formed by the ventral rami of the fifth to the eighth cervical nerves with the ascending part of the first thoracic nerve. Location of the plexus The ventral rami which form the plexus enter the lower part of the posterior triangle of the neck in series with the ventral rami of the cervical plexus. The second part of the subclavian artery lies immediately anterior to the lower two rami. The upper three rami intermingle and pass inferolaterally towards the axilla and subclavian artery. They are enclosed within an extension of the prevertebral fascia. In the neck the plexus lies deep to platysma, the supraclavicular nerves, inferior belly of omohyoid and the transverse cervical artery. It then passes deep to the clavicle and the suprascapular vessels, to enter the axilla, and thence surround the second part of the axillary artery Composition of the plexus Ventral rami, the roots of the plexus, lie between scalenus medius and anterior. As they enter the posterior triangle, the upper two (C5,6) and lower two (C8, T1) roots of the plexus unite to form the upper and lower trunks of the plexus respectively. Meanwhile, C7 continues as the middle trunk. The lower trunk may groove the superior surface of the first rib posterior to the subclavian artery, and the root from the first ventral ramus is always in contact with it. Each trunk divides into ventral and dorsal divisions which are destined to supply the anterior (flexor) and posterior (extensor) parts of the upper limb. The cords of the plexus are formed in the axilla. The dorsal divisions unite to form the posterior cord (C5-8). The ventral divisions of the upper and middle trunks unite to form the lateral cord (C5-7), while the ventral divisions of the lower trunk continues as the medial cord (C8-T1). The cords are named according to their relationship to the axillary artery. Each cord terminates by dividing into two main branches at the beginning of the third part of the artery. Sympathetic communications The fifth and sixth cervical ventral rami receive grey rami communicantes from the middle cervical ganglion, while the two or more grey rami communicantes pass from the inferior cervical ganglion to the seventh and eighth cervical ventral rami. The first thoracic ventral ramus receives its grey ramus from the cervicothoracic ganglion. Its for this reason that inferior plexus injury can be complicated by a Horners syndrome. Summary Origin Anterior rami of C5 to T1 Sections of the plexus Roots, trunks, divisions, cords, branches Mnemonic:Real Teenagers Drink Cold Beer Roots Located in the posterior triangle Pass between scalenus anterior and medius Trunks Located posterior to middle third of clavicle Upper and middle trunks related superiorly to the subclavian artery Lower trunk passes over 1st rib posterior to the subclavian artery Divisions Apex of axilla Cords Related to axillary artery

Answer 599

In Barrett's surveillance the safest option is quadrantic (i.e. 4 biopsies, one from each quarter of the oesophagus at 2cm intervals) Low grade dysplasia in conjunction with Barretts oesphagus should be monitored with regular (6 monthly) upper GI endoscopy and quadrantic biopsies. If the disease remains static at 2 years then the screening frequency may be decreased. Barrett's oesophagus Barretts oesophagus is a condition characterised by the metaplastic transformation of squamous oesophageal epithelium to columnar gastric type epithelium. Three types of this metaplastic process are recognised; intestinal (high risk), cardiac and fundic. The latter two categories may cause difficulties in diagnosis. The most concrete diagnosis can be made when endoscopic features of Barretts oesophagus are present together with a deep biopsy that demonstrates not just goblet cell metaplasia but also oesophageal glands. Barrett's can be sub divided into short (<3cm) and long (>3cm). The length of the affected segment correlates strongly with the chances of identifying metaplasia. The overall prevalence of Barrett's oesophagus is difficult to determine but may be in the region of 1 in 20 and is identified in up to 12% of those undergoing endoscopy for reflux. A proportion of patients with metaplasia will progress to dysplasia and for this reason individuals identified as having Barrett's should undergo endoscopic surveillance (every 2-5 years). Biopsies should be quadrantic and taken at 2-3cm intervals. Biopsies need to be adequate. Where mass lesions are present consideration should be given to endoscopic sub mucosal resection. Up to 40% of patients will be upstaged from high grade dysplasia to invasive malignancy with such techniques. Treatment Long term proton pump inhibitor Consider pH and manometry studies in younger patients who may prefer to consider an anti reflux procedure Regular endoscopic monitoring (more frequently if moderate dysplasia). With quadrantic biopsies every 2-3 cm If severe dysplasia be very wary of small foci of cancer References A consensus statement of the British approach is provided by: Bennett C et al Consensus Statements for Management of Barrett's Dysplasia and Early-Stage Esophageal Adenocarcinoma, Based on a Delphi Process. Gastroenterology Volume 143, Issue 2 , Pages 336-346, August 2012.

Answer 600

Standard right hemicolectomy involves colonic division to the right of the middle colic vessels Extended right hemicolectomy involves division of the middle colic vessels and usually resection of the splenic flexure as well. The question always causes confusion and to understand it the information needs to be carefully read. Firstly, the tumour is definitely at the splenic flexure and the second point is that the operation is definitely an extended right hemicolectomy. A left hemicolectomy or even the older operation of a transverse colectomy could be considered if the patient was not obstructed. However, when obstruction is present, an extended right hemicolectomy (which involves an ileocolic anastomosis) is relatively safe even in the obstructed setting. Colorectal cancer treatment Patients diagnosed as having colorectal cancer should be completely staged using CT of the chest/ abdomen and pelvis. Their entire colon should have been evaluated with colonoscopy or CT colonography. Patients whose tumours lie below the peritoneal reflection should have their mesorectum evaluated with MRI. Once their staging is complete patients should be discussed within a dedicated colorectal MDT meeting and a treatment plan formulated. Treatment of colonic cancer Cancer of the colon is nearly always treated with surgery. Stents, surgical bypass and diversion stomas may all be used as palliative adjuncts. Resectional surgery is the only option for cure in patients with colon cancer. The procedure is tailored to the patient and the tumour location. The lymphatic drainage of the colon follows the arterial supply and therefore most resections are tailored around the resection of particular lymphatic chains (e.g. ileo-colic pedicle for right sided tumours). Some patients may have confounding factors that will govern the choice of procedure, for example a tumour in a patient from a HNPCC family may be better served with a panproctocolectomy rather than segmental resection. Following resection the decision has to be made regarding restoration of continuity. For an anastomosis to heal the key technical factors include; adequate blood supply, mucosal apposition and no tissue tension. Surrounding sepsis, unstable patients and inexperienced surgeons may compromise these key principles and in such circumstances it may be safer to construct an end stoma rather than attempting an anastomosis. When a colonic cancer presents with an obstructing lesion; the options are to either stent it or resect. In modern practice it is unusual to simply defunction a colonic tumour with a proximal loop stoma. This differs from the situation in the rectum (see below). Following resection patients with risk factors for disease recurrence are usually offered chemotherapy, a combination of 5FU and oxaliplatin is common. Rectal cancer The management of rectal cancer is slightly different to that of colonic cancer. This reflects the rectum's anatomical location and the challenges posed as a result. Tumours located in the rectum can be surgically resected with either an anterior resection or an abdomino - perineal resection. The technical aspects governing the choice between these two procedures can be complex to appreciate and the main point to appreciate for the MRCS is that involvement of the sphincter complex or very low tumours require APER. In the rectum a 2cm distal clearance margin is required and this may also impact on the procedure chosen. In addition to excision of the rectal tube an integral part of the procedure is a meticulous dissection of the mesorectal fat and lymph nodes (total mesorectal excision/ TME). In rectal cancer surgery invovlement of the cirumferential resection margin carries a high risk of disease recurrence. Because the rectum is an extraperitoneal structure (until you remove it that is!) it is possible to irradiate it, something which cannot be offered for colonic tumours. This has a major impact in rectal cancer treatment and many patients will be offered neoadjuvent radiotherapy (both long and short course) prior to resectional surgery. Patients with T1, 2 and 3 /N0 disease on imaging do not require irradiation and should proceed straight to surgery. Patients with T4 disease will typically have long course chemo radiotherapy. Patients presenting with large bowel obstruction from rectal cancer should not undergo resectional surgery without staging as primary treatment (very different from colonic cancer). This is because rectal surgery is more technically demanding, the anastomotic leak rate is higher and the danger of a positive resection margin in an unstaged patient is high. Therefore patients with obstructing rectal cancer should have a defunctioning loop colostomy. Summary of procedures The operations for cancer are segmental resections based on blood supply and lymphatic drainage. These commonly performed procedures are core knowledge for the MRCS and should be understood. Site of cancer Type of resection Anastomosis Risk of leak Right colon Right hemicolectomy Ileo-colic Low <5% Transverse Extended right hemicolectomy Ileo-colic Low <5% Splenic flexure Extended right hemicolectomy Ileo-colic Low <5% Splenic flexure Left hemicolectomy Colo-colon 2-5% Left colon Left hemicolectomy Colo-colon 2-5% Sigmoid colon High anterior resection Colo-rectal 5% Upper rectum Anterior resection (TME) Colo-rectal 5% Low rectum Anterior resection (Low TME) Colo-rectal (+/- Defunctioning stoma) 10% Anal verge Abdomino-perineal excision of colon and rectum None n/a In the emergency setting, where the bowel has perforated, the risk of an anastomotic breakdown is much greater, particularly when the anastomosis is colon-colon. In this situation, an end colostomy is often safer and can be reversed later. When resection of the sigmoid colon is performed and an end colostomy is fashioned the operation is referred to as a Hartmans procedure. Whilst left sided resections are more risky, ileo-colic anastomoses are relatively safe even in the emergency setting and do not need to be defunctioned. References A review of the diagnosis and management of colorectal cancer and a summary of the UK National Institute of Clinical Excellence guidelines is provided in: Poston G, et al . Diagnosis and management of colorectal cancer: summary of NICE guidance. BMJ 2011: 343: d 6751.

Answer 601

Foramina of the base of the skull Foramen Location Contents Foramen ovale Sphenoid bone Otic ganglion V3 (Mandibular nerve:3rd branch of trigeminal) Accessory meningeal artery Lesser petrosal nerve Emissary veins Foramen spinosum Sphenoid bone Middle meningeal artery Meningeal branch of the Mandibular nerve Foramen rotundum Sphenoid bone Maxillary nerve (V2) Foramen lacerum/ carotid canal Located between the sphenoid, the apex of the petrous temporal and the basilar part of the occipital Base of the medial pterygoid plate. Internal carotid artery* Nerve and artery of the pterygoid canal Jugular foramen Temporal bone Anterior: inferior petrosal sinus Intermediate: glossopharyngeal, vagus, and accessory nerves. Posterior: sigmoid sinus (becoming the internal jugular vein) and some meningeal branches from the occipital and ascending pharyngeal arteries. Foramen magnum Occipital bone Anterior and posterior spinal arteries Vertebral arteries Medulla oblongata Stylomastoid foramen Temporal bone Stylomastoid artery Facial nerve Superior orbital fissure Sphenoid bone Oculomotor nerve (III) Recurrent meningeal artery Trochlear nerve (IV) Lacrimal, frontal and nasociliary branches of opthalmic nerve (V1) Abducent nerve (VI) Superior ophthalmic vein *= In life the foramen lacerum is occluded by a cartilagenous plug. The ICA initially passes into the carotid canal which ascends superomedially to enter the cranial cavity through the foramen lacerum.

Answer 602

No single one of the above nerves is responsible for direct cardiac innervation (which those who have handled the heart surgically will appreciate). The heart receives its nerves from the superficial and deep cardiac plexuses. The cardiac plexuses send small branches to the heart along the major vessels, continuing with the right and left coronary arteries. The vagal efferent fibres emerge from the brainstem in the roots of the vagus and accessory nerves, and run to ganglia in the cardiac plexuses and within the heart itself. The background vagal discharge serves to limit heart rate, and loss of this background vagal tone accounts for the higher resting heart rate seen following cardiac transplant. Sinoatrial node Located in the wall of the right atrium in the upper part of the sulcus terminalis from which it extends anteriorly over the opening of the superior vena cava. In most cases it is supplied by the right coronary artery. It has a complicated nerve supply from the cardiac nerve plexus that takes both sympathetic and parasympathetic fibres that run alongside the main vessels.

Answer 603

Binding to µ opioid receptors within the CNS 4 Types of opioid receptor: δ (located in CNS)- Accounts for analgesic and antidepressant effects k (mainly CNS)- analgesic and dissociative effects µ (central and peripheral) - causes analgesia, miosis, decreased gut motility Nociceptin receptor (CNS)- Affect of appetite and tolerance to µ agonists. Morphine Strong opiate analgesic. It is a pro- type narcotic drug and its effects mediated via the 4 types of opioid receptor. Its clinical effects stem from binding to these receptor sites within the CNS and gastrointestinal tract. Unwanted side effects include nausea, constipation, respiratory depression and, if used long term, addiction . It may be administered orally or intravenously. It can be reversed with naloxone.

Answer 604

Intravenous drug users are at high risk of right sided cardiac valvular endocarditis. The character of the murmur fits with a diagnosis of tricuspid valve endocarditis. Cardiac murmurs Type of Murmur Conditions Ejection systolic Aortic stenosis Pulmonary stenosis, HOCM ASD, Fallot's Pan-systolic Mitral regurgitation Tricuspid regurgitation VSD Late systolic Mitral valve prolapse Coarctation of aorta Early diastolic Aortic regurgitation Graham-Steel murmur (pulmonary regurgitation) Mid diastolic Mitral stenosis Austin-Flint murmur (severe aortic regurgitation)

Answer 605

The right middle lobe is a wedge shaped structure. Its apex is posterior and it lies deep to the 6th rib in the mid axillary line. Anteriorly, it is in contact with the 5th, 6th and 7th costal cartiladges. Lung anatomy The right lung is composed of 3 lobes divided by the oblique and transverse fissures. The left lung has two lobes divided by the oblique fissure.The apex of both lungs is approximately 4cm superior to the sterno-costal joint of the first rib. Immediately below this is a sulcus created by the subclavian artery. Peripheral contact points of the lung Base: diaphragm Costal surface: corresponds to the cavity of the chest Mediastinal surface: Contacts the mediastinal pleura. Has the cardiac impression. Above and behind this concavity is a triangular depression named the hilum, where the structures which form the root of the lung enter and leave the viscus. These structures are invested by pleura, which, below the hilum and behind the pericardial impression, forms the pulmonary ligament Right lung Above the hilum is the azygos vein; Superior to this is the groove for the superior vena cava and right innominate vein; behind this, and nearer the apex, is a furrow for the innominate artery. Behind the hilum and the attachment of the pulmonary ligament is a vertical groove for the oesophagus; In front and to the right of the lower part of the oesophageal groove is a deep concavity for the extrapericardiac portion of the inferior vena cava. The root of the right lung lies behind the superior vena cava and the right atrium, and below the azygos vein. The right main bronchus is shorter, wider and more vertical than the left main bronchus and therefore the route taken by most foreign bodies. Left lung Above the hilum is the furrow produced by the aortic arch, and then superiorly the groove accommodating the left subclavian artery; Behind the hilum and pulmonary ligament is a vertical groove produced by the descending aorta, and in front of this, near the base of the lung, is the lower part of the oesophagus. The root of the left lung passes under the aortic arch and in front of the descending aorta. Inferior borders of both lungs 6th rib in mid clavicular line 8th rib in mid axillary line 10th rib posteriorly The pleura runs two ribs lower than the corresponding lung level. Bronchopulmonary segments Segment number Right lung Left lung 1 Apical Apical 2 Posterior Posterior 3 Anterior Anterior 4 Lateral Superior lingular 5 Medial Inferior lingular 6 Superior (apical) Superior (apical) 7 Medial basal Medial basal 8 Anterior basal Anterior basal 9 Lateral basal Lateral basal 10 Posterior basal Posterior basal

Answer 606

The biceps femoris is the laterally located hamstring muscle. The semitendinosus and semimembranosus are located medially. Rupture of gastrocnemius and soleus may occur but is less common. Biceps femoris The biceps femoris is one of the hamstring group of muscles located in the posterior upper thigh. It has two heads. Long head Origin Ischial tuberosity Insertion Fibular head Action Knee flexion, lateral rotation tibia, extension hip Innervation Tibial division of sciatic nerve (L5, S1, S2) Arterial supply Profunda femoris artery, inferior gluteal artery, and the superior muscular branches of popliteal artery Short head Origin Lateral lip of linea aspera, lateral supracondylar ridge of femur Insertion Fibular head Action Knee flexion, lateral rotation tibia Innervation Common peroneal division of sciatic nerve (L5, S1, S2) Arterial supply Profunda femoris artery, inferior gluteal artery, and the superior muscular branches of popliteal artery

Answer 607

Pseudopolyps are a feature of ulcerative colitis and occur when there is severe mucosal ulceration. The remaining islands of mucosa may then appear to be isolated and almost polypoidal. Crohns disease Crohns disease is a chronic transmural inflammation of a segment(s) of the gastrointestinal tract and may be associated with extra intestinal manifestations. Frequent disease patterns observed include ileal, ileocolic and colonic disease. Peri-anal disease may occur in association with any of these. The disease is often discontinuous in its distribution. Inflammation may cause ulceration, fissures, fistulas and fibrosis with stricturing. Histology reveals a chronic inflammatory infiltrate that is usually patchy and transmural. Ulcerative colitis Vs Crohns Crohn's disease Ulcerative colitis Distribution Mouth to anus Rectum and colon Macroscopic changes Cobblestone appearance, apthoid ulceration Contact bleeding Depth of disease Transmural inflammation Superficial inflammation Distribution pattern Patchy Continuous Histological features Granulomas (non caseating epithelioid cell aggregates with Langhans' giant cells) Crypt abscesses, Inflammatory cells in the lamina propria Extraintestinal manifestations of Crohns Related to disease extent Unrelated to disease extent Aphthous ulcers (10%) Sacroiliiitis (10-15%) Erythema nodosum (5-10%) Ankylosing spondylitis (1-2%) Pyoderma gangrenosum (0.5%) Primary sclerosing cholangitis (Rare) Acute arthropathy (6-12%) Gallstones (up to 30%) Ocular complications (up to 10%) Renal calculi (up to 10%) Diarrhoea in Crohns Diarrhoea in Crohns may be multifactorial since actual inflammation of the colon is not common. Causes therefore include the following: Bile salt diarrhoea secondary to terminal ileal disease Entero-colic fistula Short bowel due to multiple resections Bacterial overgrowth Surgical interventions in Crohns disease The commonest disease pattern in Crohns is stricturing terminal ileal disease and this often culminates in an ileocaecal resection. Other procedures performed include segmental small bowel resections and stricturoplasty. Colonic involvement in patients with Crohns is not common and, where found, distribution is often segmental. However, despite this distribution segmental resections of the colon in patients with Crohns disease are generally not advocated because the recurrence rate in the remaining colon is extremely high. As a result, the standard options of colonic surgery in Crohns patients are generally; sub total colectomy, panproctocolectomy and staged sub total colectomy and proctectomy. Restorative procedures such as ileoanal pouch have no role in therapy. Crohns disease is notorious for the developmental of intestinal fistulae; these may form between the rectum and skin (peri anal) or the small bowel and skin. Fistulation between loops of bowel may also occur and result in bacterial overgrowth and malabsorption. Management of enterocutaneous fistulae involves controlling sepsis, optimising nutrition, imaging the disease and planning definitive surgical management.

Answer 608

The key in this question is that its during the caecal mobilization. The gonadal vessels and ureter are important posterior relations that are at risk during a right hemicolectomy. During latter stages of the procedure, the ileocolic artery and vein are traced along the anterior aspect of the duodenum. At this point it is possible to injure these, the superior mesenteric vein or the middle colic vein, injury to any of these can result in torrential bleeding that is very difficult to control. Caecum Location Proximal right colon below the ileocaecal valve Intraperitoneal Posterior relations Psoas Iliacus Femoral nerve Genitofemoral nerve Gonadal vessels Anterior relations Greater omentum Arterial supply Ileocolic artery Lymphatic drainage Mesenteric nodes accompany the venous drainage The caecum is the most distensible part of the colon and in complete large bowel obstruction with a competent ileocaecal valve the most likely site of eventual perforation.

Answer 609

With decreased 2,3-DPG in transfused red cells S shaped curve The curve is shifted to the left when there is a decreased oxygen requirement by the tissue. This includes: 1. Hypothermia 2. Alkalosis 3. Reduced levels of DPG: DPG is found in erythrocytes and is reduced in non exercising muscles, i.e. when there is reduced glycolysis. 4. Polycythaemia Oxygen Transport Oxygen transport Almost all oxygen is transported within erythrocytes. It has limited solubility and only 1% is carried as solution. Therefore the amount of oxygen transported will depend upon haemoglobin concentration and its degree of saturation. Haemoglobin Globular protein composed of 4 subunits. Haem consists of a protoporphyrin ring surrounding an iron atom in its ferrous state. The iron can form two additional bonds; one with oxygen and the other with a polypeptide chain. There are two alpha and two beta subunits to this polypeptide chain in an adult and together these form globin. Globin cannot bind oxygen but is able to bind to carbon dioxide and hydrogen ions, the beta chains are able to bind to 2,3 diphosphoglycerate. The oxygenation of haemoglobin is a reversible reaction. The molecular shape of haemoglobin is such that binding of one oxygen molecule facilitates the binding of subsequent molecules. Oxygen dissociation curve The oxygen dissociation curve describes the relationship between the percentage of saturated haemoglobin and partial pressure of oxygen in the blood. It is not affected by haemoglobin concentration. Chronic anaemia causes 2, 3 DPG levels to increase, hence shifting the curve to the right Haldane effect Shifts to left = for given oxygen tension there is increased saturation of Hb with oxygen i.e. Decreased oxygen delivery to tissues Bohr effect Shifts to right = for given oxygen tension there is reduced saturation of Hb with oxygen i.e. Enhanced oxygen delivery to tissues Shifts to Left = Lower oxygen delivery HbF, methaemoglobin, carboxyhaemoglobin low [H+] (alkali) low pCO2 low 2,3-DPG low temperature Shifts to Right = Raised oxygen delivery raised [H+] (acidic) raised pCO2 raised 2,3-DPG* raised temperature *2,3-diphosphoglycerate

Answer 610

Nerves at risk during a carotid endarterectomy: Hypoglossal nerve Greater auricular nerve Superior laryngeal nerve During a carotid endarterectomy the sternocleidomastoid muscle is dissected, with ligation of the common facial vein and then the internal jugular is dissected exposing the common and the internal carotid arteries. The nerves at risk during the operation include: Hypoglossal nerve Greater auricular nerve Superior laryngeal nerve The sympathetic chain lies posteriorly and is less prone to injury in this procedure. Internal carotid artery The internal carotid artery is formed from the common carotid opposite the upper border of the thyroid cartilage. It extends superiorly to enter the skull via the carotid canal. From the carotid canal it then passes through the cavernous sinus, above which it divides into the anterior and middle cerebral arteries. Relations in the neck Posterior Longus capitis Pre-vertebral fascia Sympathetic chain Superior laryngeal nerve Medially External carotid (near origin) Wall of pharynx Ascending pharyngeal artery Laterally Internal jugular vein (moves posteriorly at entrance to skull) Vagus nerve (most posterolaterally) Anteriorly Sternocleidomastoid Lingual and facial veins Hypoglossal nerve Relations in the carotid canal Internal carotid plexus Cochlea and middle ear cavity Trigeminal ganglion (superiorly) Leaves canal lies above the foramen lacerum Path and relations in the cranial cavity The artery bends sharply forwards in the cavernous sinus, the aducens nerve lies close to its inferolateral aspect. The oculomotor, trochlear, opthalmic and, usually, the maxillary nerves lie in the lateral wall of the sinus. Near the superior orbital fissure it turns posteriorly and passes postero-medially to pierce the roof of the cavernous sinus inferior to the optic nerve. It then passes between the optic and oculomotor nerves to terminate below the anterior perforated substance by dividing into the anterior and middle cerebral arteries. Branches Anterior and middle cerebral artery Ophthalmic artery Posterior communicating artery Anterior choroid artery Meningeal arteries Hypophyseal arteries

Answer 611

A teenage girl with knee pain on walking down the stairs is characteristic for chondromalacia patellae (anterior knee pain). Most cases are managed with physiotherapy. Knee injury Types of injury Ruptured anterior cruciate ligament Sport injury Mechanism: high twisting force applied to a bent knee Typically presents with: loud crack, pain and RAPID joint swelling (haemoarthrosis) Poor healing Management: intense physiotherapy or surgery Ruptured posterior cruciate ligament Mechanism: hyperextension injuries Tibia lies back on the femur Paradoxical anterior draw test Rupture of medial collateral ligament Mechanism: leg forced into valgus via force outside the leg Knee unstable when put into valgus position Menisceal tear Rotational sporting injuries Delayed knee swelling Joint locking (Patient may develop skills to 'unlock' the knee Recurrent episodes of pain and effusions are common, often following minor trauma Chondromalacia patellae Teenage girls, following an injury to knee e.g. Dislocation patella Typical history of pain on going downstairs or at rest Tenderness, quadriceps wasting Dislocation of the patella Most commonly occurs as a traumatic primary event, either through direct trauma or through severe contraction of quadriceps with knee stretched in valgus and external rotation Genu valgum, tibial torsion and high riding patella are risk factors Skyline x-ray views of patella are required, although displaced patella may be clinically obvious An osteochondral fracture is present in 5% The condition has a 20% recurrence rate Fractured patella 2 types: i. Direct blow to patella causing undisplaced fragments ii. Avulsion fracture Tibial plateau fracture Occur in the elderly (or following significant trauma in young) Mechanism: knee forced into valgus or varus, but the knee fractures before the ligaments rupture Varus injury affects medial plateau and if valgus injury, lateral plateau depressed fracture occurs Classified using the Schatzker system (see below) Schatzker Classification system for tibial plateau fractures Type Anatomical description Features 1 Vertical split of lateral condyle Fracture through dense bone, usually in the young. It may be virtually undisplaced, or the condylar fragment may be pushed inferiorly and tilted 2 Vertical split of the lateral condyle combined with an adjacent load bearing part of the condyle The wedge fragment (which may be of variable size), is displaced laterally; the joint is widened. Untreated, a valgus deformity may develop 3 Depression of the articular surface with intact condylar rim The split does not extend to the edge of the plateau. Depressed fragments may be firmly embedded in subchondral bone, the joint is stable 4 Fragment of the medial tibial condyle Two injuries are seen in this category; (1) a depressed fracture of osteoporotic bone in the elderly. (2) a high energy fracture resulting in a condylar split that runs from the intercondylar eminence to the medial cortex. Associated ligamentous injury may be severe 5 Fracture of both condyles Both condyles fractured but the column of the metaphysis remains in continuity with the tibial shaft 6 Combined condylar and subcondylar fractures High energy fracture with marked comminution

Answer 612

Platelets are stored at room temperature and must be used soon after collection. This places them at increased risk of culturing gram positive organisms. Iatrogenic infection with gram negative organisms is more likely with packed red cells as these are stored at 4 degrees. Infections with blood products of this nature are both rare. Blood products Whole blood fractions Fraction Key points Packed red cells Used for transfusion in chronic anaemia and cases where infusion of large volumes of fluid may result in cardiovascular compromise. Product obtained by centrifugation of whole blood. Platelet rich plasma Usually administered to patients who are thrombocytopaenic and are bleeding or require surgery. It is obtained by low speed centrifugation. Platelet concentrate Prepared by high speed centrifugation and administered to patients with thrombocytopaenia. Fresh frozen plasma Prepared from single units of blood. Contains clotting factors, albumin and immunoglobulin. Unit is usually 200 to 250ml. Usually used in correcting clotting deficiencies in patients with hepatic synthetic failure who are due to undergo surgery. Usual dose is 12-15ml/Kg-1. It should not be used as first line therapy for hypovolaemia. Cryoprecipitate Formed from supernatant of FFP. Rich source of Factor VIII and fibrinogen. Allows large concentration of factor VIII to be administered in small volume. SAG-Mannitol Blood Removal of all plasma from a blood unit and substitution with: Sodium chloride Adenine Anhydrous glucose Mannitol Up to 4 units of SAG M Blood may be administered. Thereafter whole blood is preferred. After 8 units, clotting factors and platelets should be considered. Cell saver devices These collect patients own blood lost during surgery and then re-infuse it. There are two main types: Those which wash the blood cells prior to re-infusion. These are more expensive to purchase and more complicated to operate. However, they reduce the risk of re-infusing contaminated blood back into the patient. Those which do not wash the blood prior to re-infusion. Their main advantage is that they avoid the use of infusion of blood from donors into patients and this may reduce risk of blood borne infection. It may be acceptable to Jehovah's witnesses. It is contraindicated in malignant disease for risk of facilitating disease dissemination. Blood products used in warfarin reversal In some surgical patients the use of warfarin can pose specific problems and may require the use of specialised blood products Immediate or urgent surgery in patients taking warfarin(1) (2): 1. Stop warfarin 2. Vitamin K (reversal within 4-24 hours) -IV takes 4-6h to work (at least 5mg) -Oral can take 24 hours to be clinically effective 3. Fresh frozen plasma Used less commonly now as 1st line warfarin reversal -30ml/kg-1 -Need to give at least 1L fluid in 70kg person (therefore not appropriate in fluid overload) -Need blood group -Only use if human prothrombin complex is not available 4. Human Prothrombin Complex (reversal within 1 hour) -Bereplex 50 u/kg -Rapid action but factor 6 short half life, therefore give with vitamin K References 1. Dentali, F., C. Marchesi, et al. (2011). 'Safety of prothrombin complex concentrates for rapid anticoagulation reversal of vitamin K antagonists. A meta-analysis.' Thromb Haemost 106(3): 429-438. 2. http://www.transfusionguidelines.org/docs/pdfs/bbt-03warfarin-reversal-flowchart-2006.pdf

Answer 613

Avascular necrosis- radiological changes occur late. Radiolucency and subchondral collapse are late changes. The earliest evidence on plain films is the affected area appearing as being more radio-opaque due to hyperaemia and resorption of the neighboring area. It may be diagnosed earlier using bone scans and MRI. Avascular necrosis Cellular death of bone components due to interruption of the blood supply, causing bone destruction Main joints affected are hip, scaphoid, lunate and the talus. It is not the same as non union. The fracture has usually united. Radiological evidence is slow to appear. Vascular ingrowth into the affected bone may occur. However, many joints will develop secondary osteoarthritis. Causes P ancreatitis L upus A lcohol S teroids T rauma I diopathic, infection C aisson disease, collagen vascular disease R adiation, rheumatoid arthritis A myloid G aucher disease S ickle cell disease Presentation Usually pain. Often despite apparent fracture union. Investigation MRI scanning will show changes earlier than plain films. Treatment In fractures at high risk sites anticipation is key. Early prompt and accurate reduction is essential. Non weight bearing may help to facilitate vascular regeneration. Joint replacement may be necessary, or even the preferred option (e.g. Hip in the elderly).

Answer 614

An inferior alveolar nerve block is a nerve block technique that anesthetizes the areas of the mouth and face innervated by one of the inferior alveolar nerves1. It may result in various symptoms, such as numbness of the lower lip and chin, parts of the tongue and gingiva, and transient facial weakness2. The best answer to your question is: Numbness of lower lip on injected side This is because the inferior alveolar nerve block affects the mental nerve, which is a branch of the inferior alveolar nerve that supplies the skin and mucous membranes of the lower lip and chin on one side1. The other options are either incorrect or less likely to occur. For example, an inferior alveolar nerve block is usually effective for the lower incisor teeth, unless there is anatomical variation or accessory innervation3. Numbness of the hard palate is not caused by an inferior alveolar nerve block, but by a maxillary nerve block. Inability to clench jaws is not a common symptom of an inferior alveolar nerve block, but it may happen if the nerve block also affects the motor branches of the mandibular nerve. Transient ipsilateral facial weakness is a rare complication of an inferior alveolar nerve block, and it may occur due to diffusion of the anesthetic agent into the parotid gland, affecting the facial nerve.

Answer 615

Elderly patients may be managed using endocrine therapy alone. Eventually most will escape hormonal control. In post menopausal women oestrogens are produced by the peripheral aromatization of androgens and aromatase inhibitors are therefore the most popular agent in this age group. Breast cancer treatment Treatment Indication Endocrine therapy Oestrogen receptor positive tumours Downstaging primary lesions Definitive treatment in old, infirm patients Irradiation Wide local excision Large lesion, high grade or marked vascular invasion following mastectomy Chemotherapy Downstaging advanced lesions to facilitate breast conserving surgery Patients with grade 3 lesions or axillary nodal disease Endocrine agents Tamoxifen is used and works as a partial oestrogen receptor agonist. It will typically block activity at the breast. It does, however, stimulate the receptors at other sites and it is this that accounts for its association with endometrial cancer. In post menopausal women the process of aromatisation accounts for most oestrogen production. Therefore in this group aromatase inhibitors are the preferred agents. Women who are perimenopausal start on tamoxifen and switch at 3 years. More recent studies (aTTom and ATLAS) have demonstrated benefits for continuing the drug for 10 years. In pre-menopausal women, there is increasing preference for the use of Exemestane over tamoxifen. Chemotherapy The FEC regime is most commonly used (Fluorouracil, epirubicin and cyclophosphamide). This was found to be superior to the older CMF regime. The Taxanes are commonly used in high risk patients and in this setting a regime of docetaxal, doxorubicin and cyclophosphamide may be used. The anthracycline class drugs have marked cardiotoxicity (a property that they share with trastuzumab) and this can limit their use.

Answer 616

The cystic duct lies outside the porta hepatis and is an important landmark in laparoscopic cholecystectomy. The structures in the porta hepatis are: Portal vein Hepatic artery Common hepatic duct These structures divide immediately after or within the porta hepatis to supply the functional left and right lobes of the liver. The porta hepatis is also surrounded by lymph nodes, that may enlarge to produce obstructive jaundice and parasympathetic nervous fibres that travel along vessels to enter the liver. Liver Structure of the liver Right lobe Supplied by right hepatic artery Contains Couinaud segments V to VIII (-/+Sg I) Left lobe Supplied by the left hepatic artery Contains Couinaud segments II to IV (+/- Sg1) Quadrate lobe Part of the right lobe anatomically, functionally is part of the left Couinaud segment IV Porta hepatis lies behind On the right lies the gallbladder fossa On the left lies the fossa for the umbilical vein Caudate lobe Supplied by both right and left hepatic arteries Couinaud segment I Lies superior to the porta hepatis Anterior and medial to the inferior vena cava Bile from the caudate lobe drains into both right and left hepatic ducts Detailed knowledge of Couinaud segments is not required for MRCS Between the liver lobules are portal canals which contain the portal triad: Hepatic Artery, Portal Vein, tributary of Bile Duct. Relations of the liver Anterior Postero inferiorly Diaphragm Oesophagus Xiphoid process Stomach Duodenum Hepatic flexure of colon Right kidney Gallbladder Inferior vena cava Porta hepatis Location Postero inferior surface, it joins nearly at right angles with the left sagittal fossa, and separates the caudate lobe behind from the quadrate lobe in front Transmits Common hepatic duct Hepatic artery Portal vein Sympathetic and parasympathetic nerve fibres Lymphatic drainage of the liver (and nodes) Ligaments Falciform ligament 2 layer fold peritoneum from the umbilicus to anterior liver surface Contains ligamentum teres (remnant umbilical vein) On superior liver surface it splits into the coronary and left triangular ligaments Ligamentum teres Joins the left branch of the portal vein in the porta hepatis Ligamentum venosum Remnant of ductus venosus Arterial supply Hepatic artery Venous Hepatic veins Portal vein Nervous supply Sympathetic and parasympathetic trunks of coeliac plexus

Answer 617

You should suspect cholangitis in a patient with fevers and jaundice. Charcot's triad may only be present in 20% of patients. Note the question states treatment option, this excludes MRCP and USS which are not treatments. Whilst PTC may access the duct, the drains may displace easily and the transduodenal route is the preferred first line access. Management of Pancreatitis Management of Acute Pancreatitis in the UK Diagnosis Traditionally hyperamylasaemia has been utilised with amylase being elevated three times the normal range. However, amylase may give both false positive and negative results. Serum lipase is both more sensitive and specific than serum amylase. It also has a longer half life. Serum amylase levels do not correlate with disease severity. Differential causes of hyperamylasaemia Acute pancreatitis Pancreatic pseudocyst Mesenteric infarct Perforated viscus Acute cholecystitis Diabetic ketoacidosis Assessment of severity Glasgow, Ranson scoring systems and APACHE II Biochemical scoring e.g. using CRP Features that may predict a severe attack within 48 hours of admission to hospital Initial assessment Clinical impression of severity Body mass index >30 Pleural effusion APACHE score >8 24 hours after admission Clinical impression of severity APACHE II >8 Glasgow score of 3 or more Persisting multiple organ failure CRP>150 48 hours after admission Glasgow Score of >3 CRP >150 Persisting or progressive organ failure Table adapted from UK guidelines for management of acute pancreatitis. GUT 2005, 54 suppl III Management Nutrition There is reasonable evidence to suggest that the use of enteral nutrition does not worsen the outcome in pancreatitis Most trials to date were underpowered to demonstrate a conclusive benefit. The rationale behind feeding is that it helps to prevent bacterial translocation from the gut, thereby contributing to the development of infected pancreatic necrosis. Use of antibiotic therapy Many UK surgeons administer antibiotics to patients with acute pancreatitis. However, there is very little evidence to support this practice. A recent Cochrane review highlights the potential benefits of administering Imipenem to patients with established pancreatic necrosis in the hope of averting the progression to infection. There are concerns that the administration of antibiotics in mild attacks of pancreatitis will not affect outcome and may contribute to antibiotic resistance and increase the risks of antibiotic associated diarrhoea. Surgery Patients with acute pancreatitis due to gallstones should undergo early cholecystectomy. Patients with obstructed biliary system due to stones should undergo early ERCP. Patients with extensive necrosis where infection is suspected should usually undergo FNA for culture. Patients with infected necrosis should undergo either radiological drainage or surgical necrosectomy. The choice of procedure depends upon local expertise. References www.bsg.org.uk/pdfworddocs/pancreatic.pdf Antibiotic therapy for prophylaxis against infection of pancreatic necrosis in acute pancreatitis. Villatoro et al. Cochrane Library DOI: 10.1002/14651858.CD002941.pub3. 2010 version.

Answer 618

There is minimum mixing of blood passing through the vessels. Circle of Willis The two internal carotid arteries and two vertebral arteries form an anastomosis known as the Circle of Willis on the inferior surface of the brain. Each half of the circle is formed by: 1. Anterior communicating artery 2. Anterior cerebral artery 3. Internal carotid artery 4. Posterior communicating artery 5. Posterior cerebral arteries and the termination of the basilar artery The circle and its branches supply; the corpus striatum, internal capsule, diencephalon and midbrain. Vertebral arteries Enter the cranial cavity via foramen magnum Lie in the subarachnoid space Ascend on anterior surface of medulla oblongata Unite to form the basilar artery at the base of the pons Branches: Posterior spinal artery Anterior spinal artery Posterior inferior cerebellar artery Basilar artery Branches: Anterior inferior cerebellar artery Labyrinthine artery Pontine arteries Superior cerebellar artery Posterior cerebral artery (at the point where it bifurcates) Internal carotid arteries Branches: Posterior communicating artery Anterior cerebral artery Middle cerebral artery Anterior choroid artery

Answer 619

Avoid emergency resections in large bowel obstruction due to rectal cancer This patient has presented with large bowel obstruction. However, in the case of rectal cancer, she is incompletely staged as ability to completely resect the lesion can only be determined with MRI scanning and this information is not provided. Even if the lesion were resectable, in the emergency setting, it is often safer to undertake a simple procedure such as a loop colostomy and then complete surgery at a later date. A low anterior resection and loop ileostomy in this situation would almost certainly leak (and for the reasons outlined above, may be incomplete). Large bowel obstruction Colonic obstruction remains a common surgical problem. It is most commonly due to malignancy (60%) and diverticular disease (20%). Volvulus affecting the colon accounts for 5% of cases. Acute colonic pseudo-obstruction remains a potential differential diagnosis in all cases. Intussusception affecting the colon (most often due to tumours in the adult population) remains a rare but recognised cause. The typical patient will present with gradual onset of progressive abdominal distension, colicky abdominal pain and either obstipation or absolute constipation. On examination abdominal distension is present, the presence of caecal tenderness (assuming no overt evidence of peritonitis) is a useful sign to elicit. A digital rectal examination and rigid sigmoidoscopy should be performed. A plain abdominal x-ray is the usual first line test and; the caecal diameter and ileocaecal valve competency should be assessed on this film. Imaging modalities Debate long surrounds the use of CT versus gastrograffin enemas. The latter investigation has always been the traditional method of determining whether a structural lesion is indeed present. However, in the UK the use of this technique has declined and in most units a CT scan will be offered as the first line investigation by the majority of radiologists (and is advocated by the ACPGBI). In most cases this will provide sufficient detail to allow operative planning, and since malignancy accounts for most presentations may also stage the disease. In the event that the radiologist cannot provide a clear statement of lesion site, the surgeon should have no hesitation in requesting a contrast enema. Surgical options The decision as to when to operate or not is determined firstly by the patients physiological status. Unstable patients require resuscitation prior to surgery and admission to a critical care unit for invasive monitoring and potential inotropic support may be needed. In patients who are otherwise stable the decision then rests on the radiological and clinical findings. As a general rule the old adage that the sun should not rise and set on unrelieved large bowel obstruction still holds true. A caecal diameter of 12cm or more in the presence of complete obstruction with a competent ileocaecal valve and caecal tenderness is a sign of impending perforation and a relative indication for prompt surgery. Right sided and transverse lesions Right sided lesions producing large bowel obstruction should generally be treated by right hemicolectomy or its extended variant if the lesion lies in the distal transverse colon or splenic flexure. In these cases an ileocolic anastomosis may be easily constructed and even in the emergency setting has a low risk of anastomotic leak. Left sided lesions The options here lie between sub total colectomy and anastomosis, left hemicolectomy with on table lavage and primary anastomosis, left hemicolectomy and end colostomy formation and finally colonic stent insertion. The usefulness of colonic stents was the subject of a Cochrane review in 2011. The authors concluded that on the basis of the data that they reviewed, there was no benefit from the use of colonic stents over conventional surgical resection with a tendency to better outcomes seen in the surgical group (1). A more recently conducted meta analysis met with the same conclusion (2). However, the recently concluded CREST trial has suggested that self expanding metallic stents can improve outcomes and avoids a stoma. Rectosigmoid lesions Lesions below the peritoneal reflection that are causing obstruction should generally be treated with a loop colostomy. Primary resection of unstaged rectal cancer would most likely carry a high CRM positivity rate and cannot be condoned. Where the lesion occupies the distal sigmoid colon the usual practice would be to perform a high anterior resection. The decision surrounding restoration of intestinal continuity would lie with the operating surgeon. References 1. Sagar J. Colorectal stents for the management of malignant colonic obstructions. Cochrane Database of Systematic Reviews 2011, Issue 11. Art. No.: CD007378. DOI: 10.1002/14651858.CD007378.pub2. 2. Cirrochi et al Safety and efficacy of endoscopic colonic stenting as a bridge to surgery in the management of intestinal obstruction due to left colon and rectal cancer: A systematic review and meta-analysis. Surg Oncol. 2013 Mar;22(1):14-21.

Answer 620

The arch of the azygos vein lies in the middle mediastinum. Mediastinum Region between the pulmonary cavities. It is covered by the mediastinal pleura. It does not contain the lungs. It extends from the thoracic inlet superiorly to the diaphragm inferiorly. Mediastinal regions Superior mediastinum (between manubriosternal angle and T4/5) Middle mediastinum Posterior mediastinum Anterior mediastinum Region Contents Superior mediastinum Superior vena cava Brachiocephalic veins Arch of aorta Thoracic duct Trachea Oesophagus Thymus Vagus nerve Left recurrent laryngeal nerve Phrenic nerve Anterior mediastinum Thymic remnants Lymph nodes Fat Middle mediastinum Pericardium Heart Aortic root Arch of azygos vein Main bronchi Posterior mediastinum Oesophagus Thoracic aorta Azygos vein Thoracic duct Vagus nerve Sympathetic nerve trunks Splanchnic nerves

Answer 621

Erythema is a classical feature of acute inflammation. Potent mediators of vascular dilatation include; histamine, prostaglandins, nitric oxide, platelet activating factor, complement C5a (and C3a) and lysosomal compounds. Although serotonin is associated with acute inflammation it is a vasoconstrictor. The effects of serotonin are dependent upon the state of the vessels in the tissues. Intact and healthy tissues and vessels will respond to a serotonin infusion with vasodilation (hence the flushing seen in carcinoid syndrome). In contrast it worsens cardiac ischaemia in myocardial infarcts when released from damaged platelets. Acute inflammation Inflammation is the reaction of the tissue elements to injury. Vascular changes occur, resulting in the generation of a protein rich exudate. So long as the injury does not totally destroy the existing tissue architecture, the episode may resolve with restoration of original tissue architecture. Vascular changes Vasodilation occurs and persists throughout the inflammatory phase. Inflammatory cells exit the circulation at the site of injury. The equilibrium that balances Starlings forces within capillary beds is disrupted and a protein rich exudate will form as the vessel walls also become more permeable to proteins. The high fibrinogen content of the fluid may form a fibrin clot. This has several important immunomodulatory functions. Sequelae Resolution Typically occurs with minimal initial injury Stimulus removed and normal tissue architecture results Organisation Delayed removal of exudate Tissues undergo organisation and usually fibrosis Suppuration Typically formation of an abscess or an empyema Sequestration of large quantities of dead neutrophils Progression to chronic inflammation Coupled inflammatory and reparative activities Usually occurs when initial infection or suppuration has been inadequately managed Causes Infections e.g. Viruses, exotoxins or endotoxins released by bacteria Chemical agents Physical agents e.g. Trauma Hypersensitivity reactions Tissue necrosis Presence of neutrophil polymorphs is a histological diagnostic feature of acute inflammation

Answer 622

The vertebral artery passes through the foramina which are located in the transverse processes of the cervical vertebra, it does not traverse the intervertebral foramen. Vertebral artery The vertebral artery is the first branch of the subclavian artery. Anatomically it is divisible into 4 regions: The first part runs to the foramen in the transverse process of C6. Anterior to this part lies the vertebral and internal jugular veins. On the left side the thoracic duct is also an anterior relation. The second part runs superiorly through the foramina of the the transverse processes of the upper 6 cervical vertebrae. Once it has passed through the transverse process of the axis it then turns superolaterally to the atlas. It is accompanied by a venous plexus and the inferior cervical sympathetic ganglion. The third part runs posteromedially on the lateral mass of the atlas. It enters the sub occipital triangle, in the groove of the upper surface of the posterior arch of the atlas. It then passes anterior to the edge of the posterior atlanto-occipital membrane to enter the vertebral canal. The fourth part passes through the spinal dura and arachnoid, running superiorly and anteriorly at the lateral aspect of the medulla oblongata. At the lower border of the pons it unites to form the basilar artery.

Answer 623

Multiple rib fractures with > or = 2 rib fractures in more than 2 ribs is diagnosed as a flail chest. This is associated with pulmonary contusion. Thoracic trauma Key points related to thoracic trauma Less than 10% of blunt chest trauma and 15-30% of penetrating chest trauma requires operative intervention. The physiologic consequences of thoracic trauma are hypoxia, hypercarbia, and acidosis. Contusion, hematoma, and alveolar collapse, or changes in intrathoracic pressure relationships (e.g., tension pneumothorax and open pneumothorax) cause hypoxia and lead to metabolic acidosis. Hypercarbia causes respiratory acidosis and most often follows inadequate ventilation caused by changes in intrathoracic pressure relationships and depressed level of consciousness. Types of thoracic trauma Tension pneumothorax Often laceration to lung parenchyma with flap Pressure develops in thorax Most common cause is mechanical ventilation in patient with pleural injury Symptoms overlap with cardiac tamponade, hyper-resonant percussion note is more likely in tension pnemothorax Flail chest Chest wall disconnects from thoracic cage Multiple rib fractures (at least two fractures per rib in at least two ribs) Associated with pulmonary contusion Abnormal chest motion Avoid over hydration and fluid overload Pneumothorax Most common cause is lung laceration with air leakage Most traumatic pneumothoraces should have a chest drain Patients with traumatic pneumothorax should never be mechanically ventilated until a chest drain is inserted Haemothorax Most commonly due to laceration of lung, intercostal vessel or internal mammary artery Haemothoraces large enough to appear on CXR are treated with large bore chest drain Surgical exploration is warranted if >1500ml blood drained immediately Cardiac tamponade Beck's triad: elevated venous pressure, reduced arterial pressure, reduced heart sounds Pulsus paradoxus May occur with as little as 100ml blood Pulmonary contusion Most common potentially lethal chest injury Arterial blood gases and pulse oximetry important Early intubation within an hour if significant hypoxia Blunt cardiac injury Usually occurs secondary to chest wall injury ECG may show features of myocardial infarction Sequelae: hypotension, arrhythmias, cardiac wall motion abnormalities Aorta disruption Deceleration injuries Contained haematoma Widened mediastinum Diaphragm disruption Most due to motor vehicle accidents and blunt trauma causing large radial tears (laceration injuries result in small tears) More common on left side Insert gastric tube, may pass into intrathoracic stomach Mediastinal traversing wounds Entrance wound in one hemithorax and exit wound/foreign body in opposite hemithorax Mediastinal haematoma or pleural cap suggests great vessel injury Mortality is 20%

Answer 624

Saphenous vein Long saphenous vein This vein may be harvested for bypass surgery, or removed as treatment for varicose veins with saphenofemoral junction incompetence. Originates at the 1st digit where the dorsal vein merges with the dorsal venous arch of the foot Passes anterior to the medial malleolus and runs up the medial side of the leg At the knee, it runs over the posterior border of the medial epicondyle of the femur bone Then passes laterally to lie on the anterior surface of the thigh before entering an opening in the fascia lata called the saphenous opening It joins with the femoral vein in the region of the femoral triangle at the saphenofemoral junction Tributaries Medial marginal Superficial epigastric Superficial iliac circumflex Superficial external pudendal veins Short saphenous vein Originates at the 5th digit where the dorsal vein merges with the dorsal venous arch of the foot, which attaches to the great saphenous vein. It passes around the lateral aspect of the foot (inferior and posterior to the lateral malleolus) and runs along the posterior aspect of the leg (with the sural nerve) Passes between the heads of the gastrocnemius muscle, and drains into the popliteal vein, approximately at or above the level of the knee joint.

Answer 625

40% of sarcomas are found in the extremities. Sarcomas Malignant tumours of mesenchymal origin Types May be either bone or soft tissue in origin. Bone sarcoma include: Osteosarcoma Ewings sarcoma (although non bony sites recognised) Chondrosarcoma - originate from Chondrocytes Soft tissue sarcoma are a far more heterogeneous group and include: Liposarcoma-adipocytes Rhabdomyosarcoma-striated muscle Leiomyosarcoma-smooth muscle Synovial sarcomas- close to joints (cell of origin not known but not synovium) Malignant fibrous histiocytoma is now referred to as undifferentiated pleomorphic sarcoma. Careful histological assessment of lesions now allows more accurate categorisation of sarcoma subtypes than was previously possible. Features Certain features of a mass or swelling should raise suspicion for a sarcoma these include: Large >5cm soft tissue mass Deep tissue location or intra muscular location Rapid growth Painful lump Assessment Imaging of suspicious masses should utilise a combination of MRI, CT and USS. Blind biopsy should not be performed prior to imaging and where required should be done in such a way that the biopsy tract can be subsequently included in any resection. Ewings sarcoma Commoner in males Incidence of 0.3 / 1, 000, 000 Onset typically between 10 and 20 years of age Location by femoral diaphysis is commonest site Histologically it is a small round tumour Blood borne metastasis is common and chemotherapy is often combined with surgery Osteosarcoma Mesenchymal cells with osteoblastic differentiation 20% of all primary bone tumours Incidence of 5 per 1,000,000 Peak age 15-30, commoner in males Limb preserving surgery may be possible and many patients will receive chemotherapy Liposarcoma Malignancy of adipocytes Rare, approximately 2.5 per 1,000,000. They are the most common soft tissue sarcoma Typically located in deep locations such as retroperitoneum Affect older age group usually >40 years of age May be well differentiated and thus slow growing although may undergo de-differentiation and disease progression Many tumours will have a pseudocapsule that can misleadingly allow surgeons to feel that they can 'shell out' these lesions. In reality, tumour may invade at the edge of the pseudocapsule and result in local recurrence if this strategy is adopted Usually resistant to radiotherapy, although this is often used in a palliative setting Malignant Fibrous Histiocytoma Tumour with large number of histiocytes Also described as undifferentiated pleomorphic sarcoma NOS (i.e. Cell of origin is not known) Four major subtypes are recognised: storiform-pleomorphic (70% cases), myxoid (less aggressive), giant cell and inflammatory Treatment is usually with surgical resection and adjuvant radiotherapy as this reduces the likelihood of local recurrence

Answer 626

Extra dural haematoma The middle meningeal artery is prone to damage when the temporal side of the head is hit. Note that there may NOT be any initial LOC or lucid interval. Head injury Patients who suffer head injuries should be managed according to ATLS principles and extra cranial injuries should be managed alongside cranial trauma. Inadequate cardiac output will compromise CNS perfusion irrespective of the nature of the cranial injury. Types of traumatic brain injury Extradural haematoma Bleeding into the space between the dura mater and the skull. Often results from acceleration-deceleration trauma or a blow to the side of the head. The majority of extradural haematomas occur in the temporal region where skull fractures cause a rupture of the middle meningeal artery. Features Raised intracranial pressure Some patients may exhibit a lucid interval Subdural haematoma Bleeding into the outermost meningeal layer. Most commonly occur around the frontal and parietal lobes. May be either acute or chronic. Risk factors include old age and alcoholism. Slower onset of symptoms than a extradural haematoma. Subarachnoid haemorrhage Usually occurs spontaneously in the context of a ruptured cerebral aneurysm, but may be seen in association with other injuries when a patient has sustained a traumatic brain injury. Pathophysiology Primary brain injury may be focal (contusion/ haematoma) or diffuse (diffuse axonal injury) Diffuse axonal injury occurs as a result of mechanical shearing following deceleration, causing disruption and tearing of axons Intra-cranial haematomas can be extradural, subdural or intracerebral, while contusions may occur adjacent to (coup) or contralateral (contre-coup) to the side of impact Secondary brain injury occurs when cerebral oedema, ischaemia, infection, tonsillar or tentorial herniation exacerbates the original injury. The normal cerebral auto regulatory processes are disrupted following trauma rendering the brain more susceptible to blood flow changes and hypoxia The Cushings reflex (hypertension and bradycardia) often occurs late and is usually a pre terminal event Management Where there is life threatening rising ICP such as in extra dural haematoma and whilst theatre is prepared or transfer arranged use of IV mannitol/ frusemide may be required. Diffuse cerebral oedema may require decompressive craniotomy Exploratory Burr Holes have little management in modern practice except where scanning may be unavailable and to thus facilitate creation of formal craniotomy flap Depressed skull fractures that are open require formal surgical reduction and debridement, closed injuries may be managed non operatively if there is minimal displacement. ICP monitoring is appropriate in those who have GCS 3-8 and normal CT scan. ICP monitoring is mandatory in those who have GCS 3-8 and abnormal CT scan. Hyponatraemia is most likely to be due to syndrome of inappropriate ADH secretion. Minimum of cerebral perfusion pressure of 70mmHg in adults. Minimum cerebral perfusion pressure of between 40 and 70 mmHg in children. Interpretation of pupillary findings in head injuries Pupil size Light response Interpretation Unilaterally dilated Sluggish or fixed 3rd nerve compression secondary to tentorial herniation Bilaterally dilated Sluggish or fixed Poor CNS perfusion Bilateral 3rd nerve palsy Unilaterally dilated or equal Cross reactive (Marcus - Gunn) Optic nerve injury Bilaterally constricted May be difficult to assess Opiates Pontine lesions Metabolic encephalopathy Unilaterally constricted Preserved Sympathetic pathway disruption

Answer 627

Quadratus lumborum Origin: Medial aspect of iliac crest and iliolumbar ligament Insertion: 12th rib Action: Pulls the rib cage inferiorly. Lateral flexion. Nerve supply: Anterior primary rami of T12 and L1-3 The rectus abdominis causes flexion of the thoracic spine and therefore the statement suggesting that quadratus lumborum does so is incorrect. Abdominal wall The 2 main muscles of the abdominal wall are the rectus abdominis (anterior) and the quadratus lumborum (posterior). The remaining abdominal wall consists of 3 muscular layers. Each muscle passes from the lateral aspect of the quadratus lumborum posteriorly to the lateral margin of the rectus sheath anteriorly. Each layer is muscular posterolaterally and aponeurotic anteriorly. Muscles of abdominal wall External oblique Lies most superficially Originates from 5th to 12th ribs Inserts into the anterior half of the outer aspect of the iliac crest, linea alba and pubic tubercle More medially and superiorly to the arcuate line, the aponeurotic layer overlaps the rectus abdominis muscle The lower border forms the inguinal ligament The triangular expansion of the medial end of the inguinal ligament is the lacunar ligament. Internal oblique Arises from the thoracolumbar fascia, the anterior 2/3 of the iliac crest and the lateral 2/3 of the inguinal ligament The muscle sweeps upwards to insert into the cartilages of the lower 3 ribs The lower fibres form an aponeurosis that runs from the tenth costal cartilage to the body of the pubis At its lowermost aspect it joins the fibres of the aponeurosis of transversus abdominis to form the conjoint tendon. Transversus abdominis Innermost muscle Arises from the inner aspect of the costal cartilages of the lower 6 ribs , from the anterior 2/3 of the iliac crest and lateral 1/3 of the inguinal ligament Its fibres run horizontally around the abdominal wall ending in an aponeurosis. The upper part runs posterior to the rectus abdominis. Lower down the fibres run anteriorly only. The rectus abdominis lies medially; running from the pubic crest and symphysis to insert into the xiphoid process and 5th, 6th and 7th costal cartilages. The muscles lies in a aponeurosis as described above. Nerve supply: anterior primary rami of T7-12 Surgical notes During abdominal surgery it is usually necessary to divide either the muscles or their aponeuroses. During a midline laparotomy it is desirable to divide the aponeurosis. This will leave the rectus sheath intact above the arcuate line and the muscles intact below it. Straying off the midline will often lead to damage to the rectus muscles, particularly below the arcuate line where they may often be in close proximity to each other.

Answer 628

A Bankart lesion is an injury of the anterior (inferior) glenoid labrum of the shoulder due to anterior shoulder dislocation. When this happens, a pocket at the front of the glenoid forms that allows the humeral head to dislocate into it. Anterior dislocations are the most common. When recurrent, a Bankart lesion is the most common underlying abnormality. This is usually visualised by CT and MRI scanning and often repaired arthroscopically. Shoulder disorders Shoulder fractures and dislocations Fractures Proximal humerus Background Third most common fragility fracture in the elderly. Results from low energy fall in predominantly elderly females, or from high energy trauma in young males. Can be associated with nerve injury (commonly axillary), and fracture-dislocation of the humeral head. Detailed neurological assessment is essential for all upper limb injuries. Anatomy Osteology Consists of articular head, greater tuberosity, lesser tuberosity, metaphysis and diaphysis. Between the articular head and the tuberosities is the anatomical neck (previous physis). Between the tuberosities and the metaphysis is the surgical neck. The supraspinatus, infraspinatus and teres minor muscles attach to the greater tuberosity. The subscapularis muscle attaches to the lesser tuberosity. Vascular Supply Humeral head is supplied by the anterior and posterior humeral circumflex arteries. Anatomical neck fractures are at greatest risk of osteonecrosis. Imaging Imaging aims to both delineate the fracture pattern, and confirm/exlude the presence of an associated dislocation. Radiographs - True anteroposterior (AP), axillary lateral and/or scapula Y view. CT - indicated to better define intra-articular involvement and to aid pre-operative planning. MRI is not useful for fracture imaging. Classification Description of the fracture is often more useful than classification. Particular attention should be paid to humeral alignment, fracture displacement, and greater tuberosity position (rotator cuff will pull the GT supero-posterioly, which can cause impingement problems with malunion). - Neer Classification: Most commonly used. Describes fracture as 2,3,or 4 part depending upon the number main fragments. Also comments on the degree of displacement. Fragments: -greater tuberosity -lesser tuberosity - articular surface - shaft Displacement: >1cm or angulation >45 degrees. Treatment The vast majority of proximal humeral fractures are minimally displaced, and therefore can be managed conservatively. This involves immobilisation in a polysling, and progressive mobilisation. Pendular exercise can commence at 14 days, and active abduction from 4-6 weeks. Irreducible fracture dislocation is an indication for operative management. Other indications include large displacement, younger patient, head splitting (intra-articular fractures). However, the recent PROFHER trial (1) has suggested no benefit to operative intervention on patient outcome (it must be applied cautiously as majority of patients were elderly with extraarticular fractures). Options available for surgical management include: ORIF Most commonly used. Plate and screw fixation. Can reconstruct complex fractures. Intramedullary nail Suitable for extra-articular configuration, predominantly surgical neck +/- GT fractures. Hemiarthroplasty Used for un-reconstructable fractures in the older patient who has good glenoid quality. Total shoulder arthroplasty Unconstructable fractures where high functioning shoulder is required (hemiarthroplasty will cause glenoid erosion) Reverse shoulder arthroplasty Total shoulder arthroplasty that provides better functional outcome than conventional total shoulder replacement. Scapula Background Uncommon fractures usually associated with high energy trauma. Most commonly involve scapula body or spine (50%), glenoid fossa and glenoid neck. Important to exclude associated life threatening injury. Imaging Plain radiographs should include true anteroposterior (AP), axillary lateral and/or scapula Y view. CT scanning is useful for defining intra-articular involvement, displacement and for three dimensional reconstruction. Classification Based on the location of the fracture (coracoid, acromion, glenoid neck, glenoid fossa, scapula body). Beware of ipsilateral glenoid neck and clavicle fracture -floating shoulder - where limb is effectively dissociated from axial skeleton. Treatment The vast majority of scapula fractures are amenable to conservative management, consisting of sling immobilisation for two weeks followed by early rehabilitation. Floating shoulder will usually require fixation, and consideration of surgery should also be given to intra-articular and displaced/angulated glenoid fractures. Dislocations Types Dislocations around the shoulder joint include glenohumeral dislocation, acromioclavicular joint disruption and sternoclavicular dislocation. Only glenohumeral dislocation will be covered here. Glenohumeral dislocation Diagnosis, classification and management are covered here. Background Shoulder dislocation is commonly seen in A&E. It has a high recurrence rate that is as high as 80% in teenagers. Initial management requires emergent reduction to prevent lasting chondral damage. Early assessment and management Usually a traumatic cause (multi-directional instability in frequent dislocations requires discussion with orthopaedics and is not covered here). Careful history, examination and documentation of neurovascular status of the limb, in particular the axillary nerve (regimental badge sensation). This should be re-assessed post manipulation. Early radiographs to confirm direction of dislocation. Initial management consists of emergent closed reduction under under entanox and analgesia, but often requires conscious sedation. Arm should then be immobilised in a polysling, and XR to confirm relocation. Imaging - True anteroposterior (AP), axillary lateral and/or scapula Y view. Reduced humeral head should lie between acromion and coracoid on lateral/scapula view. Types Direction Features Cause Examination Reduction techniques Anterior Most Common >90% Usually traumatic - anterior force on arm when shoulder is abducted, externally rotated Loss of shoulder contour - sulcus sign. Humeral head can be felt anteriorly. Hippocratic. Milch. Stimson. Kocher not advised due to complication of fracture Posterior 50% missed in A&E 50% traumatic, but classically post seizure or electrocution Shoulder locked in internal rotation. XR may show lightbulb appearance. Gentle lateral traction to adducted arm. Inferior Rare Associated with pectorals and rotator cuff tears, and glenoid fracture As for primary injury Management of primary injury Superior Rare Associated with acrominon/clavicle fracture As for primary injury Management of primary injury Associated injuries Bankart lesion - avulsion of the anterior glenoid labrum with an anterior shoulder dislocation (reverse Bankart if poster labrum in posterior dislocation). Hill Sachs defect - chondral impaction on posteriosuperior humeral head from contact with gleonoid rim. Can be large enough to lock shoulder, requiring open reduction. (Reverse Hill Sachs in posterior dislocation). Rotator cuff tear - increases with age. Greater or lesser tuberosity fracture - increases with age. Humeral neck fracture - shoulder fracture dislocation. More common in high energy trauma and elderly. Should be discussed with orthopaedics prior to any attempted reduction. Rotator Cuff Disease Rotator cuff disease is a spectrum of conditions that ranges from subacromial impingement to rotator cuff tears and eventually to rotator cuff arthropathy (arthritis). Anatomy The rotator cuff is a group of four muscles that are important in shoulder movements, and maintenance of glenohumeral stability. Muscle Scapular attachment Humeral attachment Action Innervation Supraspinatus Supraspinatus fossa Superior facet of greater tuberosity Initiation of abduction of humerus Suprascapular nerve Infraspinatus Infraspinatus fossa Posterior facet of greater tuberosity External rotation of humerus Suprascapular nerve Teres Minor Lateral border Inferior facet of greater tuberosity External rotation of humerus Axillary Nerve Subscapularis Subscapular fossa Lesser tuberosity Internal rotation of humerus Upper and lower subscapular nerve The inferior rotator cuff muscles (infraspinatus, teres minor, and subscapularis) balance the superior pull of the deltoid. Injury/tear results in upward migration of the humeral head on the glenoid (can be seen on AP radiograph). Likewise, the anterior muscles (subscapularis) are balanced with the posterior muscles (infraspinatus, teres minor). Subacromial Impingement The most common cause of shoulder pain, which results from impingement of the superior cuff on the undersurface of the acromion, and an inflammatory bursitis. Associated with certain types of acromial morphology (Bigliani classification). Presents as insidious pain which is exacerbated by overhead activities. Rotator Cuff Tear Often presents as an acute event on the background of chronic subacromial impingement in the older patient, but can present as an avulsion injury in younger patients. Majority of tears are to the superior cuff (supraspinatus, infraspinatus, teres minor), though a tear to subscapularis is associated with subcoracoid impingement. Tears present as pain and weakness when using the muscles in question. Rotator Cuff Arthropathy Defined as shoulder arthritis in the setting of rotator cuff dysfunction. Results from superior migration due to the loss of rotator cuff function and integrity. Unopposed deltoid pulls the humeral head superiorly. Associated with massive chronic cuff tears. Imaging Plain radiographs AP of the shoulder may show superior migration of the humerus with a cuff tear, and features of arthritis with arthropathy. Other causes of pain may also be identified (e.g. calcific tendonitis/fracture) Outlet view is useful for defining the acromial morphology USS Allows dynamic imaging of the cuff, and is inexpensive. However, it is very user dependent. MRI Best imaging modality for cuff pathology. Also allows imaging of the rest of the shoulder. When intra-articular pathology is suspected, can be combined with an arthrogram for improved sensitivity and specificity. Treatment Subacromial impingement Physiotherapy, oral anti-inflammatory medication Subacromial steroid injection can settle inflammation Arthroscopic subacromial decompression by shaving away the undersurface of the acromion, more space is created for the rotator cuff. Cuff integrity is assessed also at time of surgery, and can be repaired if necessary. Rotator cuff tear When considering repair of a cuff tear, the age and activity of the patient, the nature of the tear (degenerative vs. acute traumatic), and the size and retraction of the tear should be considered when making a surgical plan. Mild tears or tears in the elderly can be managed conservatively, as outlined above. Moderate tears can be repaired arthroscopically. Massive or retracted tears will often require an open repair (occasionally with a tendon transfer). Subacromial decompression is performed at the same time to reduce impingement, symptoms and recurrence. Calcific tendonitis Calcific tendonitis involves calcific deposits within tendons anywhere in the body, but most commonly in the rotator cuff (specifically the supraspinatus tendon). When present in the shoulder, it is associated with subacromial impingement and pain. Pathology More common in women aged 30-60 years. Association with diabetes and hypothyroidism There are three stages of calcification Formative phase characterized by calcific deposits Resting phase deposit is stable, but presents with impingement problems Resorptive phase phagocytic resorption. Most painful stage. Presentation Similar in presentation to subacromial impingement, with pain especially with over head activities. Atraumatic in nature. Imaging Plain radiographs show calcification of the rotator cuff, usually within 1.5cm of its insertion on the humerus. Supraspinatus outlet views can show level of impingment. Further imaging is rarely needed. Treatment Non-operative NSAIDS, steroid injection (controversial, but practiced) and physiotherapy. Approximately 75% will resolve by 6 months with conservative management. Ultrasound guided or surgical needle barbotage can break down deposits and resolve symptoms. Occasionally surgical excision is required. Adhesive capsulitis (Frozen Shoulder) Pain and loss of movement of shoulder joint, which involves fibroplastic proliferation of capsular tissue, causing soft tissue scarring and contracture. Patients present with a painful and decreased arc of motion. Associated with prolonged immobilization, previous surgery, thyroid disorders (AI) and diabetes Classically three stages which can take up to two years to resolve: Stage one the freezing and painful stage Stage two the frozen and stiff stage Stage three the thawing stage, where shoulder movement slowly improves Imaging Plain radiographs to exclude other causes of a painful shoulder MRI arthrogram may show capsular contracture, and again may be used to exclude cuff pathology. However, often not performed as diagnosis is largely clinical. Treatment Non-operative NSAIDS, steroid injection and physiotherapy. Patience is required as condition can take up to 2 years to improve. Operative MUA or arthroscopic adhesiolysis (release of adhesions) can expedite recovery, followed by intensive physiotherapy. Glenohumeral Arthritis Background May be osteoarthritis (primary or secondary to cuff tear or trauma), rheumatoid arthritis, or as part of a spondyloarthropathy. Majority of those with RA will develop symptoms. More common in the elderly Presents like any other arthritis - pain at night and with movement Imaging AP and axillary radiographs will show features of arthritis. CT/MRI is often useful to classify the shape of the glenoid and extent of bone loss when considering arthroplasty. MRI also essential to asses integrity of rotator cuff if considering shoulder replacement. Treatment Like all orthopaedics, start with simple measures: NSAIDS, management of RA, physiotherapy, steroid injection. Hemiarthroplasty can sometimes be considered if glenoid is in excellent condition or if patient has large comorbidity. Arthroscopic debridement is useful if patient has isolated ACJ arthritis, but is rarely used for glenohumeral arthritis. Total shoulder replacement is shown to produce superior outcome when compared to hemiarthroplasty in terms of pain relief, function and implant survival. Total shoulder replacement can be anatomical (ball on humerus, with cup on glenoid), or reverse geometry (ball on glenoid, with cup on humerus). Anatomical TSR requires an in tact rotator cuff, so often reverse is preferable when the cuff if questionable in integrity. References 1. JAMA. 2015;313(10):1037-1047. doi:10.1001/jama.2015.1629

Answer 629

The ulnar paradox- the higher the lesion, the less the clawing of the fingers seen clinically. At the elbow the ulnar nerve lesion affects the flexor carpi ulnaris and flexor digitorum profundus. Ulnar nerve Origin C8, T1 Supplies (no muscles in the upper arm) Flexor carpi ulnaris Flexor digitorum profundus Flexor digiti minimi Abductor digiti minimi Opponens digiti minimi Adductor pollicis Interossei muscle Third and fourth lumbricals Palmaris brevis Path Posteromedial aspect of upper arm to flexor compartment of forearm, then along the ulnar. Passes beneath the flexor carpi ulnaris muscle, then superficially over the flexor retinaculum into the palm of the hand. Branches Branch Supplies Muscular branch Flexor carpi ulnaris Medial half of the flexor digitorum profundus Palmar cutaneous branch (Arises near the middle of the forearm) Skin on the medial part of the palm Dorsal cutaneous branch Dorsal surface of the medial part of the hand Superficial branch Cutaneous fibres to the anterior surfaces of the medial one and one-half digits Deep branch Hypothenar muscles All the interosseous muscles Third and fourth lumbricals Adductor pollicis Medial head of the flexor pollicis brevis Effects of injury Damage at the wrist Wasting and paralysis of intrinsic hand muscles (claw hand) Wasting and paralysis of hypothenar muscles Loss of sensation medial 1 and half fingers Damage at the elbow Radial deviation of the wrist Clawing less in 4th and 5th digits

Answer 630

The aorta typically bifurcates at L4. This level is usually fairly constant and is often tested in the exam. Levels Transpyloric plane Level of the body of L1 Pylorus stomach Left kidney hilum (L1- left one!) Fundus of the gallbladder Neck of pancreas Duodenojejunal flexure Superior mesenteric artery Portal vein Left and right colic flexure Root of the transverse mesocolon 2nd part of the duodenum Upper part of conus medullaris Spleen Can be identified by asking the supine patient to sit up without using their arms. The plane is located where the lateral border of the rectus muscle crosses the costal margin. Anatomical planes Subcostal plane Lowest margin of 10th costal cartilage Intercristal plane Level of body L4 (highest point of iliac crest) Intertubercular plane Level of body L5 Common level landmarks Inferior mesenteric artery L3 Bifurcation of aorta into common iliac arteries L4 Formation of IVC L5 (union of common iliac veins) Diaphragm apertures Vena cava T8 Oesophagus T10 Aortic hiatus T12

Answer 631

Scaphoid fractures usually occur as a result of direct hard blow to the palm or following a fall on the out-stretched hand. The main physical signs are swelling and tenderness in the anatomical snuff box, and pain on wrist movements and on longitudinal compression of the thumb Upper limb fractures Colles' fracture Fall onto extended outstretched hands Described as a dinner fork type deformity Classical Colles' fractures have the following 3 features: Features of the injury 1. Transverse fracture of the radius 2. 1 inch proximal to the radio-carpal joint 3. Dorsal displacement and angulation Smith's fracture (reverse Colles' fracture) Volar angulation of distal radius fragment (Garden spade deformity) Caused by falling backwards onto the palm of an outstretched hand or falling with wrists flexed Bennett's fracture Intra-articular fracture of the first carpometacarpal joint Impact on flexed metacarpal, caused by fist fights X-ray: triangular fragment at ulnar base of metacarpal Monteggia's fracture Dislocation of the proximal radioulnar joint in association with an ulna fracture Fall on outstretched hand with forced pronation Needs prompt diagnosis to avoid disability Galeazzi fracture Radial shaft fracture with associated dislocation of the distal radioulnar joint Occur after a fall on the hand with a rotational force superimposed on it. On examination, there is bruising, swelling and tenderness over the lower end of the forearm. X Rays reveal the displaced fracture of the radius and a prominent ulnar head due to dislocation of the inferior radio-ulnar joint. Barton's fracture Distal radius fracture (Colles'/Smith's) with associated radiocarpal dislocation Fall onto extended and pronated wrist Scaphoid fractures Scaphoid fractures are the commonest carpal fractures. Surface of scaphoid is covered by articular cartilage with small area available for blood vessels (fracture risks blood supply) Forms floor of anatomical snuffbox Risk of fracture associated with fall onto outstretched hand (tubercle, waist, or proximal 1/3) The main physical signs are swelling and tenderness in the anatomical snuff box, and pain on wrist movements and on longitudinal compression of the thumb. Ulnar deviation AP needed for visualization of scaphoid Immobilization of scaphoid fractures difficult Radial head fracture Fracture of the radial head is common in young adults. It is usually caused by a fall on the outstretched hand. On examination, there is marked local tenderness over the head of the radius, impaired movements at the elbow, and a sharp pain at the lateral side of the elbow at the extremes of rotation (pronation and supination).

Answer 632

A thoracic cord lesion causes spastic paraperesis, hyperrflexia and extensor plantar responses (UMN lesion), incontinence, sensory loss below the lesion and 'sensory' ataxia.These features typically manifest several weeks later, once spinal shock (in which areflexia predominates) has resolved. Spinal cord - Located in a canal within the vertebral column that affords it structural support. Rostrally it continues to the medulla oblongata of the brain and caudally it tapers at a level corresponding to the L1-2 interspace (in the adult), a central structure, the filum terminale anchors the cord to the first coccygeal vertebra. The spinal cord is characterised by cervico-lumbar enlargements and these, broadly speaking, are the sites which correspond to the brachial and lumbar plexuses respectively. There are some key points to note when considering the surgical anatomy of the spinal cord: * During foetal growth the spinal cord becomes shorter than the spinal canal, hence the adult site of cord termination at the L1-2 level. * Due to growth of the vertebral column the spine segmental levels may not always correspond to bony landmarks as they do in the cervical spine. * The spinal cord is incompletely divided into two symmetrical halves by a dorsal median sulcus and ventral median fissure. Grey matter surrounds a central canal that is continuous rostrally with the ventricular system of the CNS. * The grey matter is sub divided cytoarchitecturally into Rexeds laminae. * Afferent fibres entering through the dorsal roots usually terminate near their point of entry but may travel for varying distances in Lissauers tract. In this way they may establish synaptic connections over several levels * At the tip of the dorsal horn are afferents associated with nociceptive stimuli. The ventral horn contains neurones that innervate skeletal muscle. The key point to remember when revising CNS anatomy is to keep a clinical perspective in mind. So it is worth classifying the ways in which the spinal cord may become injured. These include: Trauma either direct or as a result of disc protrusion Neoplasia either by direct invasion (rare) or as a result of pathological vertebral fracture Inflammatory diseases such as Rheumatoid disease, or OA (formation of osteophytes compressing nerve roots etc. Vascular either as a result of stroke (rare in cord) or as complication of aortic dissection Infection historically diseases such as TB, epidural abscesses. The anatomy of the cord will, to an extent dictate the clinical presentation. Some points/ conditions to remember: Brown- Sequard syndrome-Hemisection of the cord producing ipsilateral loss of proprioception and upper motor neurone signs, plus contralateral loss of pain and temperature sensation. The explanation of this is that the fibres decussate at different levels. Lesions below L1 will tend to present with lower motor neurone signs

Answer 633

There are six tunnels, each lined by its own synovial sheath. Extensor retinaculum The extensor retinaculum is a thickening of the deep fascia that stretches across the back of the wrist and holds the long extensor tendons in position. Its attachments are: The pisiform and triquetral medially The end of the radius laterally Structures related to the extensor retinaculum Structures superficial to the retinaculum Basilic vein Dorsal cutaneous branch of the ulnar nerve Cephalic vein Superficial branch of the radial nerve Structures passing deep to the extensor retinaculum Extensor carpi ulnaris tendon Extensor digiti minimi tendon Extensor digitorum and extensor indicis tendon Extensor pollicis longus tendon Extensor carpi radialis longus tendon Extensor carpi radialis brevis tendon Abductor pollicis longus and extensor pollicis brevis tendons Beneath the extensor retinaculum fibrous septa form six compartments that contain the extensor muscle tendons. Each compartment has its own synovial sheath. The radial artery The radial artery passes between the lateral collateral ligament of the wrist joint and the tendons of the abductor pollicis longus and extensor pollicis brevis. Image illustrating the topography of tendons passing under the extensor retinaculum

Answer 634

Myofibroblasts are differentiated fibroblasts, in which the cytoskeleton contains actin filaments. These cell types facilitate wound contracture and are the hallmark of a mature wound. They are almost never found in wounds less than 1 month old. Remember the question asks about the cell type asks about which cells are least likely to be found. Phases of wound healing Phase Key features Cells Timeframe Haemostasis Vasospasm in adjacent vessels Platelet plug formation and generation of fibrin rich clot Erythrocytes and platelets Seconds/ Minutes Inflammation Neutrophils migrate into wound (function impaired in diabetes). Growth factors released, including basic fibroblast growth factor and vascular endothelial growth factor. Fibroblasts replicate within the adjacent matrix and migrate into wound. Macrophages and fibroblasts couple matrix regeneration and clot substitution. Neutrophils, fibroblasts and macrophages Days Regeneration Platelet derived growth factor and transformation growth factors stimulate fibroblasts and epithelial cells. Fibroblasts produce a collagen network. Angiogenesis occurs and wound resembles granulation tissue. Fibroblasts, endothelial cells, macrophages Weeks Remodelling Longest phase of the healing process and may last up to one year (or longer). During this phase fibroblasts become differentiated (myofibroblasts) and these facilitate wound contraction. Collagen fibres are remodelled. Microvessels regress leaving a pale scar. Myofibroblasts

Answer 635

Dobutamine is a sympathomimetic with both alpha- and beta-agonist properties; it displays a considerable selectivity for beta1-cardiac receptors. Inotropes and cardiovascular receptors Inotropes are a class of drugs which work primarily by increasing cardiac output. They should be distinguished from vasoconstrictor drugs which are used specifically when the primary problem is peripheral vasodilatation. Catecholamine type agents are commonly used and work by increasing cAMP levels by adenylate cyclase stimulation. This in turn increases intracellular calcium ion mobilisation and thus the force of contraction. Adrenaline works as a beta adrenergic receptor agonist at lower doses and an alpha receptor agonist at higher doses. Dopamine causes dopamine receptor mediated renal and mesenteric vascular dilatation and beta 1 receptor agonism at higher doses. This results in increased cardiac output. Since both heart rate and blood pressure are raised, there is less overall myocardial ischaemia. Dobutamine is a predominantly beta 1 receptor agonist with weak beta 2 and alpha receptor agonist properties. Noradrenaline is a catecholamine type agent and predominantly acts as an alpha receptor agonist and serves as a peripheral vasoconstrictor. Phosphodiesterase inhibitors such as milrinone act specifically on the cardiac phosphodiesterase and increase cardiac output. Inotrope Cardiovascular receptor action Adrenaline α-1, α-2, β-1, β-2 Noradrenaline α-1,( α-2), (β-1), (β-2) Dobutamine β-1, (β 2) Dopamine (α-1), (α-2), (β-1), D-1,D-2 Minor receptor effects in brackets Effects of receptor binding α-1, α-2 vasoconstriction β-1 increased cardiac contractility and HR β-2 vasodilatation D-1 renal and spleen vasodilatation D-2 inhibits release of noradrenaline

Answer 636

Vertigo and dysarthria suggest a posterior circulation event. In the scenario of a patient complaining of posterior symptoms and a sudden deterioration in consciousness, the main differential diagnosis is of a basilar artery occlusion. Stroke: types Primary intracerebral haemorrhage (PICH, c. 10%) Presents with headache, vomiting, loss of consciousness Total anterior circulation infarcts (TACI, c. 15%) Involves middle and anterior cerebral arteries Hemiparesis/hemisensory loss Homonymous hemianopia Higher cognitive dysfunction e.g. Dysphasia Partial anterior circulation infarcts (PACI, c. 25%) Involves smaller arteries of anterior circulation e.g. upper or lower division of middle cerebral artery Higher cognitive dysfunction or two of the three TACI features Lacunar infarcts (LACI, c. 25%) Involves perforating arteries around the internal capsule, thalamus and basal ganglia Present with either isolated hemiparesis, hemisensory loss or hemiparesis with limb ataxia Posterior circulation infarcts (POCI, c. 25%) Vertebrobasilar arteries Presents with features of brainstem damage Ataxia, disorders of gaze and vision, cranial nerve lesions Lateral medullary syndrome (posterior inferior cerebellar artery) Wallenberg's syndrome Ipsilateral: ataxia, nystagmus, dysphagia, facial numbness, cranial nerve palsy Contralateral: limb sensory loss Weber's syndrome Ipsilateral III palsy Contralateral weakness -------------------------------------- Anterior cerebral artery Contralateral hemiparesis and sensory loss, lower extremity > upper Disconnection syndrome Middle cerebral artery Contralateral hemiparesis and sensory loss, upper extremity > lower Contralateral hemianopia Aphasia (Wernicke's) Gaze abnormalities Posterior cerebral artery Contralateral hemianopia with macular sparing Disconnection syndrome Lacunar Present with either isolated hemiparesis, hemisensory loss or hemiparesis with limb ataxia Lateral medulla (posterior inferior cerebellar artery) Ipsilateral: ataxia, nystagmus, dysphagia, facial numbness, cranial nerve palsy e.g. Horner's Contralateral: limb sensory loss Pontine VI nerve: horizontal gaze palsy VII nerve Contralateral hemiparesis

Answer 637

Taste to the anterior two thirds of the tongue is supplied by the facial nerve, the trigeminal supplies general sensation, this is mediated by the mandibular branch of the trigeminal nerve (via the lingual nerve). Cranial nerves Cranial nerve lesions Olfactory nerve May be injured in basal skull fractures or involved in frontal lobe tumour extension. Loss of olfactory nerve function in relation to major CNS pathology is seldom an isolated event and thus it is poor localiser of CNS pathology. Optic nerve Problems with visual acuity may result from intra ocular disorders. Problems with the blood supply such as amaurosis fugax may produce temporary visual distortion. More important surgically is the pupillary response to light. The pupillary size may be altered in a number of disorders. Nerves involved in the resizing of the pupil connect to the pretectal nucleus of the high midbrain, bypassing the lateral geniculate nucleus and the primary visual cortex. From the pretectal nucleus neurones pass to the Edinger - Westphal nucleus, motor axons from here pass along with the oculomotor nerve. They synapse with ciliary ganglion neurones; the parasympathetic axons from this then innervate the iris and produce miosis. The miotic pupil is seen in disorders such as Horner's syndrome or opiate overdose. Mydriasis is the dilatation of the pupil in response to disease, trauma, drugs (or the dark!). It is pathological when light fails to induce miosis. The radial muscle is innervated by the sympathetic nervous system. Because the parasympathetic fibres travel with the oculomotor nerve they will be damaged by lesions affecting this nerve (e.g. cranial trauma). The response to light shone in one eye is usually a constriction of both pupils. This indicates intact direct and consensual light reflexes. When the optic nerve has an afferent defect the light shining on the affected eye will produce a diminished pupillary response in both eyes. Whereas light shone on the unaffected eye will produce a normal pupillary response in both eyes. This is referred to as the Marcus Gunn pupil and is seen in conditions such as optic neuritis. In a total CN II lesion shining the light in the affected eye will produce no response. Oculomotor nerve The pupillary effects are described above. In addition it supplies all ocular muscles apart from lateral rectus and superior oblique. Thus the affected eye will be deviated inferolaterally. Levator palpebrae superioris may also be impaired resulting in impaired ability to open the eye. Trochlear nerve The eye will not be able to look down. Trigeminal nerve Largest cranial nerve. Exits the brainstem at the pons. Branches are ophthalmic, maxillary and mandibular. Only the mandibular branch has both sensory and motor fibres. Branches converge to form the trigeminal ganglion (located in Meckels cave). It supplies the muscles of mastication and also tensor veli palatine, mylohyoid, anterior belly of digastric and tensor tympani. The detailed descriptions of the various sensory functions are described in other areas of the website. The corneal reflex is important and is elicited by applying a small tip of cotton wool to the cornea, a reflex blink should occur if it is intact. It is mediated by: the naso ciliary branch of the ophthalmic branch of the trigeminal (sensory component) and the facial nerve producing the motor response. Lesions of the afferent arc will produce bilateral absent blink and lesions of the efferent arc will result in a unilateral absent blink. Abducens nerve The affected eye will have a deficit of abduction. This cranial nerve exits the brainstem between the pons and medulla. It thus has a relatively long intra cranial course which renders it susceptible to damage in raised intra cranial pressure. Facial nerve Emerges from brainstem between pons and medulla. It controls muscles of facial expression and taste from the anterior 2/3 of the tongue. The nerve passes into the petrous temporal bone and into the internal auditory meatus. It then passes through the facial canal and exits at the stylomastoid foramen. It passes through the parotid gland and divides at this point. It does not innervate the parotid gland. Its divisions are considered in other parts of the website. Its motor fibres innervate orbicularis oculi to produce the efferent arm of the corneal reflex. In surgical practice it may be injured during parotid gland surgery or invaded by malignancies of the gland and a lower motor neurone on the ipsilateral side will result. Vestibulo-cochlear nerve Exits from the pons and then passes through the internal auditory meatus. It is implicated in sensorineural hearing loss. Individuals with sensorineural hearing loss will localise the sound in webers test to the normal ear. Rinnes test will be reduced on the affected side but should still work. These two tests will distinguish sensorineural hearing loss from conductive deafness. In the latter condition webers test will localise to the affected ear and Rinnes test will be impaired on the affected side. Surgical lesions affecting this nerve include CNS tumours and basal skull fractures. It may also be damaged by the administration of ototoxic drugs (of which gentamicin is the most commonly used in surgical practice). Glossopharyngeal nerve Exits the pons just above the vagus. Receives sensory fibres from posterior 1/3 tongue, tonsils, pharynx and middle ear (otalgia may occur following tonsillectomy). It receives visceral afferents from the carotid bodies. It supplies parasympathetic fibres to the parotid gland via the otic ganglion and motor function to stylopharyngeaus muscle. The sensory function of the nerve is tested using the gag reflex. Vagus nerve Leaves the medulla between the olivary nucleus and the inferior cerebellar peduncle. Passes through the jugular foramen and into the carotid sheath. Details of the functions of the vagus nerve are covered in the website under relevant organ sub headings. Accessory nerve Exists from the caudal aspect of the brainstem (multiple branches) supplies trapezius and sternocleidomastoid muscles. The distal portion of this nerve is most prone to injury during surgical procedures. Hypoglossal nerve Emerges from the medulla at the preolivary sulcus, passes through the hypoglossal canal. It lies on the carotid sheath and passes deep to the posterior belly of digastric to supply muscles of the tongue (except palatoglossus). Its location near the carotid sheath makes it vulnerable during carotid endarterectomy surgery and damage will produce ipsilateral defect in muscle function.

Answer 638

Inguinal hernia repairs under local anaesthetic have a short operative time and patients are usually ambulant immediately afterwards. His family history is unlikely to be significant and he is at very low risk. Thromboprophylaxis in surgical patients Deep vein thrombosis may develop insidiously in many surgical patients. Untreated it may progress to result in pulmonary embolism. The following surgical patients are at increased risk of deep vein thrombosis: Surgery greater than 90 minutes at any site or greater than 60 minutes if the procedure involves the lower limbs or pelvis Acute admissions with inflammatory process involving the abdominal cavity Expected significant reduction in mobility Age over 60 years Known malignancy Thrombophilia Previous thrombosis BMI >30 Taking hormone replacement therapy or the contraceptive pill Varicose veins with phlebitis Mechanical thromboprophylaxis Early ambulation after surgery is cheap and is effective Compression stockings (contra -indicated in peripheral arterial disease) Intermittent pneumatic compression devices Foot impulse devices Therapeutic agents Agent Mode of action Uses Low molecular weight heparin Binds antithrombin causing inhibition of factor Xa Thromboprophylaxis or treatment of thromboembolic events in those with normal renal function. It is given as once daily subcutaneous injection Unfractionated heparin Binds antithrombin III affecting thrombin and factor Xa Effective anticoagulation, administered intravenously it has a rapid onset and its therapeutic effects decline quickly on stopping and infusion. Its activity is measured using the APTT. If need be it can be reversed using protamine sulphate Dabigatran Orally administered direct thrombin inhibitor Used prophylaxis in hip and knee surgery. It does not require therapeutic monitoring. It should not be used in any patient in whom there is a risk of active bleeding or imminent likelihood of surgery. It is reversed using Idarucizumab

Answer 639

Acute inflammation is not mediated by free radicals Chemical mediators facilitate the spread of inflammation into normal tissue Chemical mediators include: Lysosomal compounds Chemokines such as serotinin and histamine (released by platelets and mast cells) Other enzyme cascades producing inflammatory mediators include: Complement, kinin, coagulation system and fibrinolytic system Acute inflammation Inflammation is the reaction of the tissue elements to injury. Vascular changes occur, resulting in the generation of a protein rich exudate. So long as the injury does not totally destroy the existing tissue architecture, the episode may resolve with restoration of original tissue architecture. Vascular changes Vasodilation occurs and persists throughout the inflammatory phase. Inflammatory cells exit the circulation at the site of injury. The equilibrium that balances Starlings forces within capillary beds is disrupted and a protein rich exudate will form as the vessel walls also become more permeable to proteins. The high fibrinogen content of the fluid may form a fibrin clot. This has several important immunomodulatory functions. Sequelae Resolution Typically occurs with minimal initial injury Stimulus removed and normal tissue architecture results Organisation Delayed removal of exudate Tissues undergo organisation and usually fibrosis Suppuration Typically formation of an abscess or an empyema Sequestration of large quantities of dead neutrophils Progression to chronic inflammation Coupled inflammatory and reparative activities Usually occurs when initial infection or suppuration has been inadequately managed Causes Infections e.g. Viruses, exotoxins or endotoxins released by bacteria Chemical agents Physical agents e.g. Trauma Hypersensitivity reactions Tissue necrosis Presence of neutrophil polymorphs is a histological diagnostic feature of acute inflammation

Answer 640

Features of Klumpkes Paralysis Claw hand (MCP joints extended and IP joints flexed) Loss of sensation over medial aspect of forearm and hand Horner's syndrome Loss of flexors of the wrist A C8, T1 root lesion is called Klumpke's paralysis and is caused by delivery with the arm extended. Brachial plexus The brachial plexus extends from the neck to the axilla. It is formed by the ventral rami of the fifth to the eighth cervical nerves with the ascending part of the first thoracic nerve. Location of the plexus The ventral rami which form the plexus enter the lower part of the posterior triangle of the neck in series with the ventral rami of the cervical plexus. The second part of the subclavian artery lies immediately anterior to the lower two rami. The upper three rami intermingle and pass inferolaterally towards the axilla and subclavian artery. They are enclosed within an extension of the prevertebral fascia. In the neck the plexus lies deep to platysma, the supraclavicular nerves, inferior belly of omohyoid and the transverse cervical artery. It then passes deep to the clavicle and the suprascapular vessels, to enter the axilla, and thence surround the second part of the axillary artery Composition of the plexus Ventral rami, the roots of the plexus, lie between scalenus medius and anterior. As they enter the posterior triangle, the upper two (C5,6) and lower two (C8, T1) roots of the plexus unite to form the upper and lower trunks of the plexus respectively. Meanwhile, C7 continues as the middle trunk. The lower trunk may groove the superior surface of the first rib posterior to the subclavian artery, and the root from the first ventral ramus is always in contact with it. Each trunk divides into ventral and dorsal divisions which are destined to supply the anterior (flexor) and posterior (extensor) parts of the upper limb. The cords of the plexus are formed in the axilla. The dorsal divisions unite to form the posterior cord (C5-8). The ventral divisions of the upper and middle trunks unite to form the lateral cord (C5-7), while the ventral divisions of the lower trunk continues as the medial cord (C8-T1). The cords are named according to their relationship to the axillary artery. Each cord terminates by dividing into two main branches at the beginning of the third part of the artery. Sympathetic communications The fifth and sixth cervical ventral rami receive grey rami communicantes from the middle cervical ganglion, while the two or more grey rami communicantes pass from the inferior cervical ganglion to the seventh and eighth cervical ventral rami. The first thoracic ventral ramus receives its grey ramus from the cervicothoracic ganglion. Its for this reason that inferior plexus injury can be complicated by a Horners syndrome. Summary Origin Anterior rami of C5 to T1 Sections of the plexus Roots, trunks, divisions, cords, branches Mnemonic:Real Teenagers Drink Cold Beer Roots Located in the posterior triangle Pass between scalenus anterior and medius Trunks Located posterior to middle third of clavicle Upper and middle trunks related superiorly to the subclavian artery Lower trunk passes over 1st rib posterior to the subclavian artery Divisions Apex of axilla Cords Related to axillary artery

Answer 641

Onufs nucleus is located in the anterior horn of S2 and is the origin of neurones to the external urethral sphincter. Urinary incontinence Involuntary passage of urine. Most cases are female (80%). It has a prevalence of 11% in those aged greater than 65 years. The commonest variants include: Stress urinary incontinence (50%) Urge incontinence (15%) Mixed (35%) Males Males may also suffer from incontinence although it is a much rarer condition in men. A number of anatomical factors contribute to this. Males have 2 powerful sphincters; one at the bladder neck and the other in the urethra. Damage to the bladder neck mechanism is a factor in causing retrograde ejaculation following prostatectomy. The short segment of urethra passing through the urogenital diaphragm consists of striated muscle fibres (the external urethral sphincter) and smooth muscle capable of more sustained contraction. It is the latter mechanism that maintains continence following prostatectomy. Females The sphincter complex at the level of bladder neck is poorly developed in females. As a result the external sphincter complex is functionally more important, its composition being similar to that of males. Innervation is via the pudendal nerve and the neuropathy that may accompany obstetric events may compromise this and lead to stress urinary incontinence. Innervation Somatic innervation to the bladder is via the pudendal, hypogastric and pelvic nerves. Autonomic nerves travel in these nerve fibres too. Bladder filling leads to detrusor relaxation (sympathetic) coupled with sphincter contraction. The parasympathetic system causes detrusor contraction and sphincter relaxation. Overall control of micturition is centrally mediated via centres in the Pons. Stress urinary incontinence 50% of cases, especially in females. Damage (often obstetric) to the supporting structures surrounding the bladder may lead to urethral hypermobility. Other cases due to sphincter dysfunction, usually from neurological disorders (e.g. Pudendal neuropathy, multiple sclerosis). Urethral mobility: Pressure not transmitted appropriately to the urethra resulting in involuntary passage of urine during episodes of raised intra-abdominal pressure. Sphincter dysfunction: Sphincter fails to adapt to compress urethra resulting in involuntary passage of urine. When the sphincter completely fails there is often to continuous passage of urine. Urge incontinence In these patients there is sense of urgency followed by incontinence. The detrusor muscle in these patients is unstable and urodynamic investigation will demonstrate overactivity of the detrusor muscle at inappropriate times (e.g. Bladder filling). Urgency may be seen in patients with overt neurological disorders and those without. The pathophysiology is not well understood but poor central and peripheral co-ordination of the events surrounding bladder filling are the main processes. Assessment Careful history and examination including vaginal examination for cystocele. Bladder diary for at least 3 days Consider flow cystometry if unclear symptomatology or surgery considered and diagnosis is unclear. Exclusion of other organic disease (e.g. Stones, UTI, Cancer) Management Conservative measures should be tried first; Stress urinary incontinence or mixed symptoms should undergo 3 months of pelvic floor exercise. Over active bladder should have 6 weeks of bladder retraining. Drug therapy for women with overactive bladder should be offered oxybutynin (or solifenacin if elderly) if conservative measures fail. In women with detrusor instability who fail non operative therapy a trial of sacral neuromodulation may be considered, with conversion to permanent implant if good response. Augmentation cystoplasty is an alternative but will involve long term intermittent self catheterisation. In women with stress urinary incontinence a urethral sling type procedure may be undertaken. Where cystocele is present in association with incontinence it should be repaired particularly if it lies at the introitus. NICE guidelines Initial assessment urinary incontinence should be classified as stress/urge/mixed. At least 3/7 bladder diary if unable to classify easily. Start conservative treatment before urodynamic studies if a diagnosis is obvious from the history Urodynamic studies if plans for surgery. Stress incontinence: Pelvic floor exercises 3/12, if fails consider surgery. Urge incontinence: Bladder training >6/52, if fails for oxybutynin (antimuscarinic drugs) then sacral nerve stimulation. Pelvic floor exercises offered to all women in their 1st pregnancy.

Answer 642

Cervical ribs occur as a result of the elongation of the transverse process of the 7th cervical vertebra. It is usually a fibrous band that attaches to the first thoracic rib. Cervical ribs 0.2-0.4% incidence Most cases present with neurological symptoms Consist of an anomalous fibrous band that often originates from C7 and may arc towards, but rarely reaches the sternum Congenital cases may present around the third decade, some cases are reported to occur following trauma Bilateral in up to 70% Compression of the subclavian artery may produce absent radial pulse on clinical examination and in particular may result in a positive Adsons test (lateral flexion of the neck towards the symptomatic side and traction of the symptomatic arm- leads to obliteration of radial pulse) Treatment is most commonly undertaken when there is evidence of neurovascular compromise. A transaxillary approach is the traditional operative method for excision.

Answer 643

Peroneus longus is innervated by the superficial peroneal nerve (L4, L5, S1).

Answer 644

The time frame of deterioration of an acute sub dural bleed would fit with this scenario. They are highly lethal and not uncommon injuries. As the bleed enlarges, lateralising signs may be seen and eventually coning and death will occur. Intra cranial haemorrhage Extradural haematoma Bleeding into the space between the dura mater and the skull. Often results from acceleration-deceleration trauma or a blow to the side of the head. The majority of extradural haematomas occur in the temporal region where skull fractures cause a rupture of the middle meningeal artery. Features Raised intracranial pressure Some patients may exhibit a lucid interval Subdural haematoma Bleeding into the outermost meningeal layer. Most commonly occur around the frontal and parietal lobes. May be either acute or chronic. Risk factors include old age and alcoholism. Slower onset of symptoms than a extradural haematoma. Intracerebral haematoma Usually hyperdense lesions on CT scanning. Arise in areas of traumatic contusion which fuse to become a haematoma. Areas of clot and fresh blood may co-exist on the same CT scan (Swirl sign). Large haematomas and those associated with mass effect should be evacuated. Subarachnoid haemorrhage Usually occurs spontaneously in the context of a ruptured cerebral aneurysm but may be seen in association with other injuries when a patient has sustained a traumatic brain injury Intraventricular haemorrhage Haemorrhage that occurs into the ventricular system of the brain. It is relatively rare in adult surgical practice and when it does occur, it is typically associated with severe head injuries. In premature neonates it may occur spontaneously. The blood may clot and occlude CSF flow, hydrocephalus may result. In neonatal practice the vast majority of IVH occur in the first 72 hours after birth, the aetiology is not well understood and it is suggested to occur as a result of birth trauma combined with cellular hypoxia, together with the delicate neonatal CNS.

Answer 645

The flexor digiti minimi brevis originates from the Hamate, on its under- surface lie the ulnar contribution to the superficial palmar arterial arch and digital nerves derived from the ulnar nerve. The median nerve overlies the flexor tendons. Hand Anatomy of the hand Bones 8 Carpal bones 5 Metacarpals 14 phalanges Intrinsic Muscles 8 Interossei - Supplied by ulnar nerve 4 palmar-adduct fingers 4 dorsal- abduct fingers Intrinsic muscles Lumbricals Flex MCPJ and extend the IPJ. Origin deep flexor tendon and insertion dorsal extensor hood mechanism. Innervation: 1st and 2nd- median nerve, 3rd and 4th- deep branch of the ulnar nerve. Thenar eminence Abductor pollicis brevis Opponens pollicis Flexor pollicis brevis Hypothenar eminence Opponens digiti minimi Flexor digiti minimi brevis Abductor digiti minimi Fascia and compartments of the palm The fascia of the palm is continuous with the antebrachial fascia and the fascia of the dorsum of the hand. The palmar fascia is thin over the thenar and hypothenar eminences. In contrast, the central palmar fascia is relatively thick. The palmar aponeurosis covers the soft tissues and overlies the flexor tendons. The apex of the palmar aponeurosis is continuous with the flexor retinaculum and the palmaris longus tendon. Distally, it forms four longitudinal digital bands that attach to the bases of the proximal phalanges, blending with the fibrous digital sheaths. A medial fibrous septum extends deeply from the medial border of the palmar aponeurosis to the 5th metacarpal. Lying medial to this are the hypothenar muscles. In a similar fashion, a lateral fibrous septum extends deeply from the lateral border of the palmar aponeurosis to the 3rd metacarpal. The thenar compartment lies lateral to this area. Lying between the thenar and hypothenar compartments is the central compartment. It contains the flexor tendons and their sheaths, the lumbricals, the superficial palmar arterial arch and the digital vessels and nerves. The deepest muscular plane is the adductor compartment, which contains adductor pollicis. Short muscles of the hand These comprise the lumbricals and interossei. The four slender lumbrical muscles flex the fingers at the metacarpophalangeal joints and extend the interphalangeal joint. The four dorsal interossei are located between the metacarpals and the four palmar interossei lie on the palmar surface of the metacarpals in the interosseous compartment of the hand. Long flexor tendons and sheaths in the hand The tendons of FDS and FDP enter the common flexor sheath deep to the flexor retinaculum. The tendons enter the central compartment of the hand and fan out to their respective digital synovial sheaths. Near the base of the proximal phalanx, the tendon of FDS splits to permit the passage of FDP. The FDP tendons are attached to the margins of the anterior aspect of the base of the distal phalanx. The fibrous digital sheaths contain the flexor tendons and their synovial sheaths. These extend from the heads of the metacarpals to the base of the distal phalanges. Palmar Interossei Note that there are 4 palmar interossei. The first is a small slip of muscle which arises from the ulnar side of the base of the first metacarpal and passes between the head of the first dorsal interosseous and the oblique head of adductor pollicis to insert into the ulnar base of the of the proximal phalanx of the thumb. The second arises from the ulnar side of the body of the second metacarpal and is inserted into the ulnar side of the extensor hood of the index. The third and fourth palmar interossei arise from the radial sides of the bodies of the 4th and 5th metacarpals respectively and insert into the radial sides of the extensor hoods of the ring and little fingers.

Answer 646

Rotator cuff tears are common in elderly people and may occur following minor trauma or as a result of long standing impingement. Tears greater than 2cm should generally be repaired surgically. The length of the history in this scenario is suggestive of a tear complicating impingement. Shoulder disorders Shoulder fractures and dislocations Fractures Proximal humerus Background Third most common fragility fracture in the elderly. Results from low energy fall in predominantly elderly females, or from high energy trauma in young males. Can be associated with nerve injury (commonly axillary), and fracture-dislocation of the humeral head. Detailed neurological assessment is essential for all upper limb injuries. Anatomy Osteology Consists of articular head, greater tuberosity, lesser tuberosity, metaphysis and diaphysis. Between the articular head and the tuberosities is the anatomical neck (previous physis). Between the tuberosities and the metaphysis is the surgical neck. The supraspinatus, infraspinatus and teres minor muscles attach to the greater tuberosity. The subscapularis muscle attaches to the lesser tuberosity. Vascular Supply Humeral head is supplied by the anterior and posterior humeral circumflex arteries. Anatomical neck fractures are at greatest risk of osteonecrosis. Imaging Imaging aims to both delineate the fracture pattern, and confirm/exlude the presence of an associated dislocation. Radiographs - True anteroposterior (AP), axillary lateral and/or scapula Y view. CT - indicated to better define intra-articular involvement and to aid pre-operative planning. MRI is not useful for fracture imaging. Classification Description of the fracture is often more useful than classification. Particular attention should be paid to humeral alignment, fracture displacement, and greater tuberosity position (rotator cuff will pull the GT supero-posterioly, which can cause impingement problems with malunion). - Neer Classification: Most commonly used. Describes fracture as 2,3,or 4 part depending upon the number main fragments. Also comments on the degree of displacement. Fragments: -greater tuberosity -lesser tuberosity - articular surface - shaft Displacement: >1cm or angulation >45 degrees. Treatment The vast majority of proximal humeral fractures are minimally displaced, and therefore can be managed conservatively. This involves immobilisation in a polysling, and progressive mobilisation. Pendular exercise can commence at 14 days, and active abduction from 4-6 weeks. Irreducible fracture dislocation is an indication for operative management. Other indications include large displacement, younger patient, head splitting (intra-articular fractures). However, the recent PROFHER trial (1) has suggested no benefit to operative intervention on patient outcome (it must be applied cautiously as majority of patients were elderly with extraarticular fractures). Options available for surgical management include: ORIF Most commonly used. Plate and screw fixation. Can reconstruct complex fractures. Intramedullary nail Suitable for extra-articular configuration, predominantly surgical neck +/- GT fractures. Hemiarthroplasty Used for un-reconstructable fractures in the older patient who has good glenoid quality. Total shoulder arthroplasty Unconstructable fractures where high functioning shoulder is required (hemiarthroplasty will cause glenoid erosion) Reverse shoulder arthroplasty Total shoulder arthroplasty that provides better functional outcome than conventional total shoulder replacement. Scapula Background Uncommon fractures usually associated with high energy trauma. Most commonly involve scapula body or spine (50%), glenoid fossa and glenoid neck. Important to exclude associated life threatening injury. Imaging Plain radiographs should include true anteroposterior (AP), axillary lateral and/or scapula Y view. CT scanning is useful for defining intra-articular involvement, displacement and for three dimensional reconstruction. Classification Based on the location of the fracture (coracoid, acromion, glenoid neck, glenoid fossa, scapula body). Beware of ipsilateral glenoid neck and clavicle fracture -floating shoulder - where limb is effectively dissociated from axial skeleton. Treatment The vast majority of scapula fractures are amenable to conservative management, consisting of sling immobilisation for two weeks followed by early rehabilitation. Floating shoulder will usually require fixation, and consideration of surgery should also be given to intra-articular and displaced/angulated glenoid fractures. Dislocations Types Dislocations around the shoulder joint include glenohumeral dislocation, acromioclavicular joint disruption and sternoclavicular dislocation. Only glenohumeral dislocation will be covered here. Glenohumeral dislocation Diagnosis, classification and management are covered here. Background Shoulder dislocation is commonly seen in A&E. It has a high recurrence rate that is as high as 80% in teenagers. Initial management requires emergent reduction to prevent lasting chondral damage. Early assessment and management Usually a traumatic cause (multi-directional instability in frequent dislocations requires discussion with orthopaedics and is not covered here). Careful history, examination and documentation of neurovascular status of the limb, in particular the axillary nerve (regimental badge sensation). This should be re-assessed post manipulation. Early radiographs to confirm direction of dislocation. Initial management consists of emergent closed reduction under under entanox and analgesia, but often requires conscious sedation. Arm should then be immobilised in a polysling, and XR to confirm relocation. Imaging - True anteroposterior (AP), axillary lateral and/or scapula Y view. Reduced humeral head should lie between acromion and coracoid on lateral/scapula view. Types Direction Features Cause Examination Reduction techniques Anterior Most Common >90% Usually traumatic - anterior force on arm when shoulder is abducted, externally rotated Loss of shoulder contour - sulcus sign. Humeral head can be felt anteriorly. Hippocratic. Milch. Stimson. Kocher not advised due to complication of fracture Posterior 50% missed in A&E 50% traumatic, but classically post seizure or electrocution Shoulder locked in internal rotation. XR may show lightbulb appearance. Gentle lateral traction to adducted arm. Inferior Rare Associated with pectorals and rotator cuff tears, and glenoid fracture As for primary injury Management of primary injury Superior Rare Associated with acrominon/clavicle fracture As for primary injury Management of primary injury Associated injuries Bankart lesion - avulsion of the anterior glenoid labrum with an anterior shoulder dislocation (reverse Bankart if poster labrum in posterior dislocation). Hill Sachs defect - chondral impaction on posteriosuperior humeral head from contact with gleonoid rim. Can be large enough to lock shoulder, requiring open reduction. (Reverse Hill Sachs in posterior dislocation). Rotator cuff tear - increases with age. Greater or lesser tuberosity fracture - increases with age. Humeral neck fracture - shoulder fracture dislocation. More common in high energy trauma and elderly. Should be discussed with orthopaedics prior to any attempted reduction. Rotator Cuff Disease Rotator cuff disease is a spectrum of conditions that ranges from subacromial impingement to rotator cuff tears and eventually to rotator cuff arthropathy (arthritis). Anatomy The rotator cuff is a group of four muscles that are important in shoulder movements, and maintenance of glenohumeral stability. Muscle Scapular attachment Humeral attachment Action Innervation Supraspinatus Supraspinatus fossa Superior facet of greater tuberosity Initiation of abduction of humerus Suprascapular nerve Infraspinatus Infraspinatus fossa Posterior facet of greater tuberosity External rotation of humerus Suprascapular nerve Teres Minor Lateral border Inferior facet of greater tuberosity External rotation of humerus Axillary Nerve Subscapularis Subscapular fossa Lesser tuberosity Internal rotation of humerus Upper and lower subscapular nerve The inferior rotator cuff muscles (infraspinatus, teres minor, and subscapularis) balance the superior pull of the deltoid. Injury/tear results in upward migration of the humeral head on the glenoid (can be seen on AP radiograph). Likewise, the anterior muscles (subscapularis) are balanced with the posterior muscles (infraspinatus, teres minor). Subacromial Impingement The most common cause of shoulder pain, which results from impingement of the superior cuff on the undersurface of the acromion, and an inflammatory bursitis. Associated with certain types of acromial morphology (Bigliani classification). Presents as insidious pain which is exacerbated by overhead activities. Rotator Cuff Tear Often presents as an acute event on the background of chronic subacromial impingement in the older patient, but can present as an avulsion injury in younger patients. Majority of tears are to the superior cuff (supraspinatus, infraspinatus, teres minor), though a tear to subscapularis is associated with subcoracoid impingement. Tears present as pain and weakness when using the muscles in question. Rotator Cuff Arthropathy Defined as shoulder arthritis in the setting of rotator cuff dysfunction. Results from superior migration due to the loss of rotator cuff function and integrity. Unopposed deltoid pulls the humeral head superiorly. Associated with massive chronic cuff tears. Imaging Plain radiographs AP of the shoulder may show superior migration of the humerus with a cuff tear, and features of arthritis with arthropathy. Other causes of pain may also be identified (e.g. calcific tendonitis/fracture) Outlet view is useful for defining the acromial morphology USS Allows dynamic imaging of the cuff, and is inexpensive. However, it is very user dependent. MRI Best imaging modality for cuff pathology. Also allows imaging of the rest of the shoulder. When intra-articular pathology is suspected, can be combined with an arthrogram for improved sensitivity and specificity. Treatment Subacromial impingement Physiotherapy, oral anti-inflammatory medication Subacromial steroid injection can settle inflammation Arthroscopic subacromial decompression by shaving away the undersurface of the acromion, more space is created for the rotator cuff. Cuff integrity is assessed also at time of surgery, and can be repaired if necessary. Rotator cuff tear When considering repair of a cuff tear, the age and activity of the patient, the nature of the tear (degenerative vs. acute traumatic), and the size and retraction of the tear should be considered when making a surgical plan. Mild tears or tears in the elderly can be managed conservatively, as outlined above. Moderate tears can be repaired arthroscopically. Massive or retracted tears will often require an open repair (occasionally with a tendon transfer). Subacromial decompression is performed at the same time to reduce impingement, symptoms and recurrence. Calcific tendonitis Calcific tendonitis involves calcific deposits within tendons anywhere in the body, but most commonly in the rotator cuff (specifically the supraspinatus tendon). When present in the shoulder, it is associated with subacromial impingement and pain. Pathology More common in women aged 30-60 years. Association with diabetes and hypothyroidism There are three stages of calcification Formative phase characterized by calcific deposits Resting phase deposit is stable, but presents with impingement problems Resorptive phase phagocytic resorption. Most painful stage. Presentation Similar in presentation to subacromial impingement, with pain especially with over head activities. Atraumatic in nature. Imaging Plain radiographs show calcification of the rotator cuff, usually within 1.5cm of its insertion on the humerus. Supraspinatus outlet views can show level of impingment. Further imaging is rarely needed. Treatment Non-operative NSAIDS, steroid injection (controversial, but practiced) and physiotherapy. Approximately 75% will resolve by 6 months with conservative management. Ultrasound guided or surgical needle barbotage can break down deposits and resolve symptoms. Occasionally surgical excision is required. Adhesive capsulitis (Frozen Shoulder) Pain and loss of movement of shoulder joint, which involves fibroplastic proliferation of capsular tissue, causing soft tissue scarring and contracture. Patients present with a painful and decreased arc of motion. Associated with prolonged immobilization, previous surgery, thyroid disorders (AI) and diabetes Classically three stages which can take up to two years to resolve: Stage one the freezing and painful stage Stage two the frozen and stiff stage Stage three the thawing stage, where shoulder movement slowly improves Imaging Plain radiographs to exclude other causes of a painful shoulder MRI arthrogram may show capsular contracture, and again may be used to exclude cuff pathology. However, often not performed as diagnosis is largely clinical. Treatment Non-operative NSAIDS, steroid injection and physiotherapy. Patience is required as condition can take up to 2 years to improve. Operative MUA or arthroscopic adhesiolysis (release of adhesions) can expedite recovery, followed by intensive physiotherapy. Glenohumeral Arthritis Background May be osteoarthritis (primary or secondary to cuff tear or trauma), rheumatoid arthritis, or as part of a spondyloarthropathy. Majority of those with RA will develop symptoms. More common in the elderly Presents like any other arthritis - pain at night and with movement Imaging AP and axillary radiographs will show features of arthritis. CT/MRI is often useful to classify the shape of the glenoid and extent of bone loss when considering arthroplasty. MRI also essential to asses integrity of rotator cuff if considering shoulder replacement. Treatment Like all orthopaedics, start with simple measures: NSAIDS, management of RA, physiotherapy, steroid injection. Hemiarthroplasty can sometimes be considered if glenoid is in excellent condition or if patient has large comorbidity. Arthroscopic debridement is useful if patient has isolated ACJ arthritis, but is rarely used for glenohumeral arthritis. Total shoulder replacement is shown to produce superior outcome when compared to hemiarthroplasty in terms of pain relief, function and implant survival. Total shoulder replacement can be anatomical (ball on humerus, with cup on glenoid), or reverse geometry (ball on glenoid, with cup on humerus). Anatomical TSR requires an in tact rotator cuff, so often reverse is preferable when the cuff if questionable in integrity. References 1. JAMA. 2015;313(10):1037-1047. doi:10.1001/jama.2015.1629

Answer 647

The presence of a blown right pupil is a sign of a third cranial nerve compression. The most likely cause is an extradural bleed. However, since this option is not listed the process of trans tentorial herniation would be the most applicable answer. Intraventricular bleeds are typically more common in premature neonates, deterioration due to hydrocephalus is more chronic. Head injuries Head injury is the commonest cause of death and disability in people aged 1-40 years in the UK. In the UK 1.4 million people will attend emergency departments each year with a recent head injury. The typical patterns are described below: Extradural haematoma Bleeding into the space between the dura mater and the skull. Often results from acceleration-deceleration trauma or a blow to the side of the head. The majority of extradural haematomas occur in the temporal region where skull fractures cause a rupture of the middle meningeal artery. Features Raised intracranial pressure Some patients may exhibit a lucid interval Subdural haematoma Bleeding into the outermost meningeal layer. Most commonly occur around the frontal and parietal lobes. May be either acute or chronic. Risk factors include old age and alcoholism. Slower onset of symptoms than a extradural haematoma. Subarachnoid haemorrhage Usually occurs spontaneously in the context of a ruptured cerebral aneurysm but may be seen in association with other injuries when a patient has sustained a traumatic brain injury

Answer 648

Superior and inferior gluteal nerve Superior gluteal nerve Arises from dorsal surface of the sacral plexus (L4, L5, S1) Passes into gluteal region together with superior gluteal vessels Supplies gluteus medius and minimus Inferior gluteal nerve Arises from dorsal surface of sacral plexus (L5, S1 and S2) Runs medial to the posterior femoral cutaneous nerve Enters gluteal region at inferior border of piriformis Supplies gluteus maximus

Answer 649

Nerves at risk during branchial cyst excision: Mandibular branch of facial nerve, greater auricular nerve and accessory nerve. They do not move on swallowing. They should be diagnosed with caution in those aged >40 years, as lumps in this age group may in fact be metastatic disease from oropharyngeal cancer. Neck lumps The table below gives characteristic exam question features for conditions causing neck lumps: Reactive lymphadenopathy By far the most common cause of neck swellings. There may be a history of local infection or a generalised viral illness Lymphoma Rubbery, painless lymphadenopathy The phenomenon of pain whilst drinking alcohol is very uncommon There may be associated night sweats and splenomegaly Thyroid swelling May be hypo-, eu- or hyperthyroid symptomatically Moves upwards on swallowing Thyroglossal cyst More common in patients < 20 years old Usually midline, between the isthmus of the thyroid and the hyoid bone Moves upwards with protrusion of the tongue May be painful if infected Pharyngeal pouch More common in older men Represents a posteromedial herniation between thyropharyngeus and cricopharyngeus muscles Usually not seen, but if large then a midline lump in the neck that gurgles on palpation Typical symptoms are dysphagia, regurgitation, aspiration and chronic cough Cystic hygroma A congenital lymphatic lesion (lymphangioma) typically found in the neck, classically on the left side Most are evident at birth, around 90% present before 2 years of age Branchial cyst An oval, mobile cystic mass that develops between the sternocleidomastoid muscle and the pharynx Develop due to failure of obliteration of the second branchial cleft in embryonic development Usually present in early adulthood Cervical rib More common in adult females Around 10% develop thoracic outlet syndrome Carotid aneurysm Pulsatile lateral neck mass which doesn't move on swallowing

Answer 650

The posterior cord gives rise to: Radial nerve ((innervates the triceps, brachioradialis, wrist extensors, and finger extensors) Axillary nerve (innervates deltoid and teres minor) Upper subscapular nerve (innervates subscapularis) Lower subscapular nerve (innervates teres major and subscapularis) Thoracodorsal nerve (innervates latissimus dorsi) This is a description of a posterior cord lesion. Remember that the posterior cord gives rise to the axillary and radial nerve.

Answer 651

The right recurrent laryngeal nerve branches off the right vagus more proximally and arches posteriorly round the subclavian artery. So of the structures given it is the least likely to be injured. Mediastinum Region between the pulmonary cavities. It is covered by the mediastinal pleura. It does not contain the lungs. It extends from the thoracic inlet superiorly to the diaphragm inferiorly. Mediastinal regions Superior mediastinum (between manubriosternal angle and T4/5) Middle mediastinum Posterior mediastinum Anterior mediastinum Region Contents Superior mediastinum Superior vena cava Brachiocephalic veins Arch of aorta Thoracic duct Trachea Oesophagus Thymus Vagus nerve Left recurrent laryngeal nerve Phrenic nerve Anterior mediastinum Thymic remnants Lymph nodes Fat Middle mediastinum Pericardium Heart Aortic root Arch of azygos vein Main bronchi Posterior mediastinum Oesophagus Thoracic aorta Azygos vein Thoracic duct Vagus nerve Sympathetic nerve trunks Splanchnic nerves

Answer 652

Screening for colonic cancer using CEA is not justified Carcinoembryonic antigen is elevated in colonic cancer, typically in relation to disease extent with highest serum levels noted in metastatic disease. It is falsely elevated in a number of non-malignant disease states such as cirrhosis and colitis and for this reason it has no role in monitoring colitics for colonic cancer[1]. Reference 1. Sturgeon, C.M., L.C. Lai, and M.J. Duffy. Serum tumour markers: how to order and interpret them. BMJ, 2009. 339: p. b3527. Colorectal cancer screening and diagnosis Overview Most cancers develop from adenomatous polyps. Screening for colorectal cancer has been shown to reduce mortality by 16% The NHS now has a national screening programme offering screening every 2 years to all men and women aged 60 to 69 years. Patients aged over 70 years may request screening Eligible patients are sent faecal occult blood (FOB) tests through the post. This is being replaced by FIT testing. Patients with abnormal results are offered a colonoscopy - The NHS BOSS flexible sigmoidoscopy screening comprises a single flexible sigmoidoscopy to patients aged 55 years At colonoscopy, approximately: 5 out of 10 patients will have a normal exam 4 out of 10 patients will be found to have polyps which may be removed due to their premalignant potential 1 out of 10 patients will be found to have cancer Diagnosis Essentially the following patients need referral: - Altered bowel habit for more than six weeks - New onset of rectal bleeding - Symptoms of tenesmus Colonoscopy is the gold standard, provided it is complete and good mucosal visualisation is achieved. Other options include double contrast barium enema and CT colonography. Staging Once a malignant diagnosis is made patients with colonic cancer will be staged using chest / abdomen and pelvic CT. Patients with rectal cancer will also undergo evaluation of the mesorectum with pelvic MRI scanning. For examination purposes the Dukes and TNM systems are preferred. Tumour markers Carcinoembryonic antigen (CEA) is the main tumour marker in colorectal cancer. Not all tumours secrete this, and it may be raised in conditions such as IBD. However, absolute levels do correlate (roughly) with disease burden and it is once again being used routinely in follow up.

Answer 653

It is important to distinguish between blood and urine tests for carcinoid syndrome. Blood tests usually measure chromogranin A,neuron-specific enolase (NSE), substance P, and gastrin. Urine tests usually measure 5 HIAA, which is a metabolite of serotonin. Sometimes blood tests for 5 hydroxytryptamine (serotonin) are also performed. Carcinoid syndrome Carcinoid tumours secrete serotonin Originate in neuroendocrine cells mainly in the intestine (midgut-distal ileum/appendix) Can occur in the rectum, bronchi Hormonal symptoms mainly occur when disease spreads outside the bowel Clinical features Onset: insidious over many years Flushing face Palpitations Pulmonary valve stenosis and tricuspid regurgitation causing dyspnoea Asthma Severe diarrhoea (secretory, persists despite fasting) Investigation 5-HIAA in a 24-hour urine collection Somatostatin receptor scintigraphy CT scan Blood testing for chromogranin A Treatment Octreotide Surgical removal

Answer 654

Although the primary lesion is small enough for breast conserving surgery, the presence of overt axillary lymph node metastasis will attract a recommendation for axillary node clearance. Note that an excision biopsy is not appropriate for malignant cases. Breast cancer management - Surgery is performed in most patients suffering from breast cancer. Chemotherapy may be used to downstage tumours and allow breast conserving surgery. Hormonal therapy may also be used for the same purposes. Radiotherapy is given to most patients who have undergone breast conserving surgery (some older patients receiving hormone treatment and who have small low grade tumours may safely avoid DXT. Therapeutic mammoplasty is an option for some patients but requires symmetrizing surgery in most cases. Patients who have undergone mastectomy may be offered a reconstructive procedure either in conjunction with their primary resection or as a staged procedure at a later date. Surgical options Mastectomy vs Wide local excision Mastectomy Wide Local Excision Multifocal tumour Solitary lesion Central tumour Peripheral tumour Large lesion in small breast Small lesion in large breast DCIS >4cm DCIS <4cm Patient Choice Patient choice Central lesions may be managed using breast conserving surgery, where an acceptable cosmetic result may be obtained, this is rarely the case in small breasts Axillary disease As a minimum, all patients with invasive breast cancer should have their axilla staged. In those who do not have overt evidence of axillary nodal involvement this can be undertaken using sentinel lymph node biopsy. Patients with a positive sentinel lymph node biopsy or who have imaging and cytological or histological evidence of axillary nodal metastasis should undergo axillary node clearance or axillary irradiation. Axillary node clearance is associated with the development of lymphoedema, increased risk of cellulitis and frozen shoulder.

Answer 655

Diabetes may be complicated by vessel calcification and neuropathic pain. Therefore individuals may present with pain which is atypical for claudication both in terms of its tempo of onset and location. Ankle-Brachial pressure index Measurement of ankle- brachial pressure index (ABPI) is a commonly performed vascular investigation. Calculated by dividing lower limb pressure by the highest upper limb pressure. Results of ABPI 1.2 or greater Usually due to vessel calcification 1.0- 1.2 Normal 0.8-1.0 Minor stenotic lesion Initiate risk factor management 0.50-0.8 Moderate stenotic lesion Consider duplex Risk factor management If mixed ulcers present then avoid tight compression bandages 0.3 - 0.5 Likely significant stenosis Duplex scanning to delineate lesions needed Compression bandaging contra indicated Less than 0.3 Indicative of critical ischaemia Urgent detailed imaging required

Answer 656

Both unfractionated and low-molecular weight heparin can cause hyperkalaemia. This is thought to be caused by inhibition of aldosterone secretion. Salbutamol is a recognised treatment for hyperkalaemia. Hyperkalaemia - Plasma potassium levels are regulated by a number of factors including aldosterone, acid-base balance and insulin levels. Metabolic acidosis is associated with hyperkalaemia as hydrogen and potassium ions compete with each other for exchange with sodium ions across cell membranes and in the distal tubule. ECG changes seen in hyperkalaemia include tall-tented T waves, small P waves, widened QRS leading to a sinusoidal pattern and asystole Causes of hyperkalaemia Acute renal failure Drugs*: potassium sparing diuretics, ACE inhibitors, angiotensin 2 receptor blockers, spironolactone, ciclosporin, heparin** Metabolic acidosis Addison's Tissue necrosis/rhabdomyolysis: burns, trauma Massive blood transfusion Foods that are high in potassium Salt substitutes (i.e. Contain potassium rather than sodium) Bananas, oranges, kiwi fruit, avocado, spinach, tomatoes *beta-blockers interfere with potassium transport into cells and can potentially cause hyperkalaemia in renal failure patients - remember beta-agonists, e.g. Salbutamol, are sometimes used as emergency treatment **both unfractionated and low-molecular weight heparin can cause hyperkalaemia. This is thought to be caused by inhibition of aldosterone secretion

Answer 657

Risk factors for developing active tuberculosis include: silicosis chronic renal failure HIV positive solid organ transplantation with immunosuppression intravenous drug use haematological malignancy anti-TNF treatment previous gastrectomy Tuberculosis Tuberculosis (TB) is an infection caused by Mycobacterium tuberculosis that most commonly affects the lungs. Understanding the pathophysiology of TB can be difficult - the key is to differentiate between primary and secondary disease. Primary tuberculosis A non-immune host who is exposed to M. tuberculosis may develop primary infection of the lungs. A small lung lesion known as a Ghon focus develops. The Ghon focus is composed of tubercle-laden macrophages. The combination of a Ghon focus and hilar lymph nodes is known as a Ghon complex In immunocompetent people the initial lesion usually heals by fibrosis. Those who are immunocompromised may develop disseminated disease (miliary tuberculosis). Secondary (post-primary) tuberculosis If the host becomes immunocompromised the initial infection may become reactivated. Reactivation generally occurs in the apex of the lungs and may spread locally or to more distant sites. Possible causes of immunocomprise include: immunosuppressive drugs including steroids HIV malnutrition The lungs remain the most common site for secondary tuberculosis. Extra-pulmonary infection may occur in the following areas: central nervous system (tuberculous meningitis - the most serious complication) vertebral bodies (Pott's disease) cervical lymph nodes (scrofuloderma) renal gastrointestinal tract

Answer 658

It contains the saphenous nerve, femoral vein and the superficial branch of the femoral artery. Adductor canal Also called Hunter's or subsartorial canal Immediately distal to the apex of the femoral triangle, lying in the middle third of the thigh. Canal terminates at the adductor hiatus. Borders Contents Laterally Vastus medialis muscle Saphenous nerve Posteriorly Adductor longus, adductor magnus Superficial femoral artery Roof Sartorius Superficial femoral vein

Answer 659

It terminates by dividing into the superficial temporal and maxillary branches. The external carotid has eight branches, 3 from its anterior surface ; thyroid, lingual and facial. The pharyngeal artery is a medial branch. The posterior auricular and occipital are posterior branches. External carotid artery The external carotid commences immediately lateral to the pharyngeal side wall. It ascends and lies anterior to the internal carotid and posterior to the posterior belly of digastric and stylohyoid. More inferiorly it is covered by sternocleidomastoid, passed by hypoglossal nerves, lingual and facial veins. It then pierces the fascia of the parotid gland finally dividing into its terminal branches within the gland itself. Surface marking of the carotid This is an imaginary line drawn from the bifurcation of the common carotid passing behind the angle of the jaw to a point immediately anterior to the tragus of the ear. Branches of the external carotid artery It has six main branches, three in front, two behind and one deep. Three in front Superior thyroid Lingual Facial Two behind Occipital Posterior auricular Deep Ascending pharyngeal It terminates by dividing into the superficial temporal and maxillary arteries in the parotid gland.

Answer 660

The middle meningeal artery is the most likely source of the extradural haematoma in this setting. It is a branch of the maxillary artery. The middle cerebral artery does not give rise to the middle meningeal artery. Note that the question is asking for the vessel which gives rise to the middle meningeal artery ('the likely culprit vessel is a branch of which of the following') Middle meningeal artery Middle meningeal artery is typically the third branch of the first part of the maxillary artery, one of the two terminal branches of the external carotid artery. After branching off the maxillary artery in the infratemporal fossa, it runs through the foramen spinosum to supply the dura mater (the outermost meninges) . The middle meningeal artery is the largest of the three (paired) arteries which supply the meninges, the others being the anterior meningeal artery and the posterior meningeal artery. The middle meningeal artery runs beneath the pterion. It is vulnerable to injury at this point, where the skull is thin. Rupture of the artery may give rise to an extra dural hematoma. In the dry cranium, the middle meningeal, which runs within the dura mater surrounding the brain, makes a deep indention in the calvarium. The middle meningeal artery is intimately associated with the auriculotemporal nerve which wraps around the artery making the two easily identifiable in the dissection of human cadavers and also easily damaged in surgery.

Answer 661

The accessory nerve has a number of lymph nodes applied to it near the sternocleidomastoid muscle. It is particularly at risk if SCM is mobilized. If injured, the trapezius muscle and SCM will be paralysed. Trapezius Origin Medial third of the superior nuchal line of the occiput External occipital protruberance Ligamentum nuchae Spines of C7 and all thoracic vertebrae and all intervening interspinous ligaments Insertion Posterior border of the lateral third of the clavicle Medial border of the acromion Upper border of the crest of the spine of the scapula Nerve supply Spinal portion of the accessory nerve Actions Elevation of the shoulder girdle Lateral rotation of the scapula

Answer 662

B-Abdominal ultrasound A left sided varicocele is a recognized presenting sign of a renal tumour occluding the renal vein (into which left testicular vein drains). An abdominal ultrasound should be undertaken to exclude this. Surgery for uncomplicated varicocele is usually unnecessary.

Answer 663

B-Rhabdomyosarcoma Rhabdomyosarcomas are paratesticular tumours with a bimodal distribution. Because the mass is felt separate to the testis, this is the more likely diagnosis. • 5% of testicular tumors • Most often arises of distal portion of spermatic cord and may invade testis or surounding tissues • Bimodal age distribution - 3-4 months - 16 years • Arises from mesenchymal tissue - 90% embryonal variant (better prognosis) - 30% - 50% have metastasis (usually lymph node) at diagnosis

Answer 664

Anaemia is seldom seen in appendicitis and if present should prompt a search for an alternative underlying diagnosis. Sickle cell anaemia is characterised by severe chronic haemolytic anaemia resulting from poorly formed erythrocytes. Painful crises result from vaso-occlusive episodes, which may occur spontaneously or may be precipitated by infection. Consider this diagnosis in all children of appropriate ethnic background. Acute abdominal pain-diagnoses Conditions presenting with acute abdominal pain Condition Features Investigations Management Appendicitis History of migratory pain. Fever. Anorexia. Evidence of right iliac fossa tenderness. Mild pyrexia. Differential white cell count Pregnancy test C-Reactive protein Amylase Urine dipstick testing Appendicectomy Mesenteric adenitis Usually recent upper respiratory tract infection. High fever. Generalised abdominal discomfort- true localised pain and signs are rare. Full blood count- may show slightly raised white cell count Urine dipstick often normal Abdominal ultrasound scan - usually no free fluid Conservative management- appendicectomy if diagnostic doubt Mittelschmerz Only seen in females Mid cycle pain Usually occurs two weeks after last menstrual period Pain usually has a supra-pubic location Usually subsides over a 24-48 hour period. Full blood count- normal Urine dipstick- normal Abdominal and pelvic ultrasound- may show a trace of pelvic free fluid Manage conservatively if doubt or symptoms fail to settle then laparoscopy Fitz-Hugh Curtis syndrome Disseminated infection with Chlamydia. Usually seen in females. Consists of evidence of pelvic inflammatory disease together with peri-hepatic inflammation and subsequent adhesion formation. Abdominal ultrasound scan- may show free fluid High vaginal swabs - may show evidence of sexually transmitted infections Usually medically managed- doxycycline or azithromycin Abdominal aortic aneurysm (ruptured) Sudden onset of abdominal pain radiating to the back in older adults (look for risk factors). Collapse. May be moribund on arrival in casualty, more stable if contained haematoma. Careful clinical assessment may reveal pulsatile mass. Patients who are haemodynamically stable should have a CT scan Unstable patients should undergo immediate surgery (unless it is not in their best interests). Those with evidence of contained leak on CT should undergo immediate surgery Increasing unruptured aneurysmal size is an indication for urgent surgical intervention (that can wait until the next working day) Perforated peptic ulcer Sudden onset of pain (usually epigastric). Often preceding history of upper abdominal pain. Soon develop generalised abdominal pain. On examination may have clinical evidence of peritonitis. Erect CXR may show free air. A CT scan may be indicated where there is diagnostic doubt Laparotomy (laparoscopic surgery for perforated peptic ulcers is both safe and feasible in experienced hands) Intestinal obstruction Colicky abdominal pain and vomiting (the nature of which depends on the level of the obstruction). Abdominal distension and constipation (again depending upon site of obstruction). Features of peritonism may occur where local necrosis of bowel loops is occurring. A plain abdominal film may help with making the diagnosis. A CT scan may be useful where diagnostic uncertainty exists In those with a virgin abdomen a lower and earlier threshold for laparotomy should exist than in those who may have adhesional obstruction Mesenteric infarction Embolic events present with sudden pain and forceful evacuation. Acute on chronic events usually have a longer history and previous weight loss. On examination the pain is typically greater than the physical signs would suggest. Arterial pH and lactate Arterial phase CT scanning is the most sensitive test Immediate laparotomy and resection of affected segments, in acute embolic events SMA embolectomy may be needed.

Answer 665

Most insulinomas are benign and radical resection is therefore not justified. Insulinoma - Insulin producing tumours of the pancreatic β cells Incidence of 1 per 1,000,000 per year 90% of lesions are benign Most tumours less than 2cm in size Between 5 and 10% have MEN type 1 75% of patients with MEN 1 will develop pancreatic islet cell tumours Typical features of insulinoma Symptomatic hypoglycaemia during fasting Concomitant blood glucose of less than 3mmol/L Relief of hypoglycaemia by use of glucose Testing When neuroglycopenic symptoms occur blood is taken for serum insulin levels, serum glucose, C-peptide and pro insulin concentrations. The plasma insulin concentration is >10 micro U/ml in patients with the disorder. Tumour localisation USS (25% accuracy), endoscopic USS better (75% accuracy) CT scanning (pancreatic protocol=40% accuracy) Malignant insulinomas are larger and diagnostic accuracy with MRI is nearly 100% in such cases Somatostatin receptor scintigraphy (50% accuracy) Treatment Since the majority of tumours are benign; the blind segmental resection of the pancreas (e.g. Whipples) cannot be justified, this may be considered acceptable for malignant lesions. The best approach at laparotomy is to corroborate pre operative imaging with intraoperative ultrasonography to identify the lesion. Tumours may be close to the pancreatic duct and this must be appreciated by the operating surgeon. The perioperative use of octreotide reduces the amount of pancreatic drainage, but not overall complications.

Answer 666

S1, Q3, T3 J waves are pathognomonic of hypothermia. Pulmonary Embolism: ECG changes - No changes S1, Q3, T3 Tall R waves: V1 P pulmonale (peaked P waves): inferior leads Right axis deviation, Right bundle branch block Atrial arrhythmias T wave inversion: V1, V2, V3 Right ventricular strain: if identified is associated with adverse short-term outcome and adds prognostic value to echocardiographic evidence of right ventricular dysfunction in patients with acute pulmonary embolism and normal blood pressure. References Vanni S et al. Prognostic value of ECG among patients with acute pulmonary embolism and normal blood pressure. Am J Med. 2009 Mar;122(3):257-64.

Answer 667

Tranexamic acid inhibits plasmin and this prevents fibrin degradation. Tranexamic acid Tranexamic acid is a synthetic derivative of lysine. Its primary mode of action is as an anti fibrinolytic that competitively inhibits the conversion of plasminogen to plasmin. Plasmin degrades fibrin and therefore rendering plasmin inactive slows this process. The role of tranexamic acid in trauma was investigated in the CRASH 2 trial and has been shown to be of benefit in bleeding trauma when administered in the first 3 hours.

Answer 668

It is likely that the patient has hereditary spherocytosis. Given the familial nature, EBV infection is unlikely and so a Paul Bunnell test will be negative. Lymphoma would be unusual and Spur cells are seen in association with liver disease and / or renal failure. Hereditary Spherocytosis Most common disorder of the red cell membrane, it has an incidence of 1 in 5000. The abnormally shaped erythrocytes are prone to splenic sequestration and destruction. This can result in hyperbilirubinaemia, jaundice and splenomegaly. In older patients an intercurrent illness may increase the rate of red cell destruction resulting in more acute symptoms. Severe cases may benefit from splenectomy.

Answer 669

The tumour is too low for restorative surgery to be considered with an acceptable functional outcome. The tumour will therefore require an ELAPE style abdomino perineal resection. Since the lesion is T2 there is no prognostic benefit from adding radiotherapy which will confer additional morbidity. Colorectal cancer treatment Patients diagnosed as having colorectal cancer should be completely staged using CT of the chest/ abdomen and pelvis. Their entire colon should have been evaluated with colonoscopy or CT colonography. Patients whose tumours lie below the peritoneal reflection should have their mesorectum evaluated with MRI. Once their staging is complete patients should be discussed within a dedicated colorectal MDT meeting and a treatment plan formulated. Treatment of colonic cancer Cancer of the colon is nearly always treated with surgery. Stents, surgical bypass and diversion stomas may all be used as palliative adjuncts. Resectional surgery is the only option for cure in patients with colon cancer. The procedure is tailored to the patient and the tumour location. The lymphatic drainage of the colon follows the arterial supply and therefore most resections are tailored around the resection of particular lymphatic chains (e.g. ileo-colic pedicle for right sided tumours). Some patients may have confounding factors that will govern the choice of procedure, for example a tumour in a patient from a HNPCC family may be better served with a panproctocolectomy rather than segmental resection. Following resection the decision has to be made regarding restoration of continuity. For an anastomosis to heal the key technical factors include; adequate blood supply, mucosal apposition and no tissue tension. Surrounding sepsis, unstable patients and inexperienced surgeons may compromise these key principles and in such circumstances it may be safer to construct an end stoma rather than attempting an anastomosis. When a colonic cancer presents with an obstructing lesion; the options are to either stent it or resect. In modern practice it is unusual to simply defunction a colonic tumour with a proximal loop stoma. This differs from the situation in the rectum (see below). Following resection patients with risk factors for disease recurrence are usually offered chemotherapy, a combination of 5FU and oxaliplatin is common. Rectal cancer The management of rectal cancer is slightly different to that of colonic cancer. This reflects the rectum's anatomical location and the challenges posed as a result. Tumours located in the rectum can be surgically resected with either an anterior resection or an abdomino - perineal resection. The technical aspects governing the choice between these two procedures can be complex to appreciate and the main point to appreciate for the MRCS is that involvement of the sphincter complex or very low tumours require APER. In the rectum a 2cm distal clearance margin is required and this may also impact on the procedure chosen. In addition to excision of the rectal tube an integral part of the procedure is a meticulous dissection of the mesorectal fat and lymph nodes (total mesorectal excision/ TME). In rectal cancer surgery invovlement of the cirumferential resection margin carries a high risk of disease recurrence. Because the rectum is an extraperitoneal structure (until you remove it that is!) it is possible to irradiate it, something which cannot be offered for colonic tumours. This has a major impact in rectal cancer treatment and many patients will be offered neoadjuvent radiotherapy (both long and short course) prior to resectional surgery. Patients with T1, 2 and 3 /N0 disease on imaging do not require irradiation and should proceed straight to surgery. Patients with T4 disease will typically have long course chemo radiotherapy. Patients presenting with large bowel obstruction from rectal cancer should not undergo resectional surgery without staging as primary treatment (very different from colonic cancer). This is because rectal surgery is more technically demanding, the anastomotic leak rate is higher and the danger of a positive resection margin in an unstaged patient is high. Therefore patients with obstructing rectal cancer should have a defunctioning loop colostomy. Summary of procedures The operations for cancer are segmental resections based on blood supply and lymphatic drainage. These commonly performed procedures are core knowledge for the MRCS and should be understood. Site of cancer Type of resection Anastomosis Risk of leak Right colon Right hemicolectomy Ileo-colic Low <5% Transverse Extended right hemicolectomy Ileo-colic Low <5% Splenic flexure Extended right hemicolectomy Ileo-colic Low <5% Splenic flexure Left hemicolectomy Colo-colon 2-5% Left colon Left hemicolectomy Colo-colon 2-5% Sigmoid colon High anterior resection Colo-rectal 5% Upper rectum Anterior resection (TME) Colo-rectal 5% Low rectum Anterior resection (Low TME) Colo-rectal (+/- Defunctioning stoma) 10% Anal verge Abdomino-perineal excision of colon and rectum None n/a In the emergency setting, where the bowel has perforated, the risk of an anastomotic breakdown is much greater, particularly when the anastomosis is colon-colon. In this situation, an end colostomy is often safer and can be reversed later. When resection of the sigmoid colon is performed and an end colostomy is fashioned the operation is referred to as a Hartmans procedure. Whilst left sided resections are more risky, ileo-colic anastomoses are relatively safe even in the emergency setting and do not need to be defunctioned. References A review of the diagnosis and management of colorectal cancer and a summary of the UK National Institute of Clinical Excellence guidelines is provided in: Poston G, et al . Diagnosis and management of colorectal cancer: summary of NICE guidance. BMJ 2011: 343: d 6751.

Answer 670

Otic ganglion Secretion of saliva by the parotid gland is controlled by nerve fibres originating in the inferior salivatory nucleus; these leave the brain via the tympanic nerve (branch of glossopharyngeal nerve (CN IX), travel through the tympanic plexus (located in the middle ear), and then form the lesser petrosal nerve until reaching the otic ganglion. After synapsing in the Otic ganglion, the postganglionic (postsynaptic) fibres travel as part of the auriculotemporal nerve (a branch of the mandibular nerve (V3) to reach the parotid gland. Parotid gland Anatomy of the parotid gland Location Overlying the mandibular ramus; anterior and inferior to the ear. Salivary duct Crosses the masseter, pierces the buccinator and drains adjacent to the 2nd upper molar tooth (Stensen's duct). Structures passing through the gland Facial nerve (Mnemonic: The Zebra Buggered My Cat; Temporal Zygomatic, Buccal, Mandibular, Cervical) External carotid artery Retromandibular vein Auriculotemporal nerve Relations Anterior: masseter, medial pterygoid, superficial temporal and maxillary artery, facial nerve, stylomandibular ligament Posterior: posterior belly digastric muscle, sternocleidomastoid, stylohyoid, internal carotid artery, mastoid process, styloid process Arterial supply Branches of external carotid artery Venous drainage Retromandibular vein Lymphatic drainage Deep cervical nodes Nerve innervation Parasympathetic-Secretomotor Sympathetic-Superior cervical ganglion Sensory- Greater auricular nerve Parasympathetic stimulation produces a water rich, serous saliva. Sympathetic stimulation leads to the production of a low volume, enzyme-rich saliva.

Answer 671

Zinc is mainly absorbed in the duodenum and jejunum. Bile reflux may occur post gastrectomy. The risk of bile reflux is lower if a Roux en Y reconstruction is used. Post gastrectomy syndromes Post gastrectomy syndromes may vary slightly depending upon whether a total or partial gastrectomy is performed. A Roux en Y reconstruction generally gives the best functional outcomes. Where a gastrojejunostomy is performed as reconstruction following a distal gastrectomy the gastric emptying is generally better if the jejunal limbs are tunneled in the retrocolic plane. The following may occur following gastrectomy: Small capacity (early satiety) Dumping syndrome Bile gastritis Afferent loop syndrome Efferent loop syndrome Anaemia (B12 deficiency) Metabolic bone disease

Answer 672

It's an easy question really, we just made the wording difficult (on purpose). It is asking about the branches of the axillary artery and knowledge of the fact that there is an extensive collateral network around the shoulder joint. As a result, the occlusion of the proximal aspect of the circumflex humeral inflow (from the axillary artery) ceases and there is then retrograde flow through it from collaterals. The circumflex scapular artery is a branch of the subscapular artery and normally supplies the muscle on the dorsal aspect of the scapula. In this instance, flow is reversed in the circumflex scapular and subscapular arteries forming a collateral circulation around the scapula. Axillary artery The axillary artery extends from the outer border of the first rib to the lower border of teres major, where it becomes the brachial artery. The vessel is subdivided into three zones; the first part lies above pectoralis minor, the second part is behind the muscle and the third part lies inferior to it. First part Together with the axillary vein, the artery is enclosed within the cords of the brachial plexus. Both vessels are contained within the axillary sheath, a prolongation of the prevertebral fascia. Posteriomedial to the sheath lies the first intercostal space, the superior aspect of the serratus anterior and the long thoracic nerve. Within the sheath, the medial cord of the brachial plexus lies behind the artery. Anteriorly lies the clavipectoral fascia. Superolaterally, lie the lateral and posterior cords of the brachial plexus. Inferomedially lies the axillary vein. Second part Posterior to the second part lies the posterior cord of the brachial plexus and the subscapularis muscle. Anteriorly, lie pectoralis minor and major. The lateral cord of the brachial plexus lies laterally. Medially, lies the medial cord of the brachial plexus, here it separates the artery from the vein. Third part Posterior to the artery lie subscapularis, latissimus dorsi and teres major. Interspersed between the vessel and subscapularis are the axillary and radial nerves. Anterior to the vessel is the medial root of the median nerve. Laterally, the lies the median and musculocutaneous nerves and coracobrachialis. The axillary vein is related medially. Branches of the axillary artery Highest thoracic artery Thoraco-acromial artery Lateral thoracic artery Subscapular artery Posterior circumflex humeral artery Anterior circumflex humeral artery

Answer 673

The accessory nerve has a superficial course and is easily injured. It lies under platysma and may be divided during the early part of the procedure. Accessory nerve The cranial root of the accessory nerve arises from the caudal two thirds of the nucleus ambiguus and the caudal four fifths of the dorsal nucleus of the vagus. The cranial root emerges as four rootlets from the dorsolateral surface of the medulla oblongata below those of the vagus. It then traverses the jugular foramen. On exiting the jugular foramen it separates from its spinal part. Whereupon its cranial fibres joint those of the vagus to innervate some of the palatal muscles. The fibres arising from the spinal root exit near the junction between the spinal cord and the medulla. The fibres pass rostrally to unite with the cranial roots to exit through the jugular foramen. As outlined above these separate on exiting the foramen. The spinal part then crosses the transverse process of the atlas, and is crossed by the occipital artery as it does so. It descends obliquely, medial to the styloid process, stylohyoid and the posterior belly of digastric. It then reaches the upper part of sternocleidomastoid to enter its upper surface. It typically exits this muscle a little above the midpoint of the posterior aspect of it. This point is usually 4-6cm below the tip of the mastoid process. It crosses the posterior triangle on the levator scapulae separated from it by the pre vertebral layer of deep cervical fascia. At this point, the nerve is superficial and related to the superficial cervical lymph nodes. Approximately 3-5 cm above the clavicle it passes behind the anterior border of trapezius which it innervates.

Answer 674

This is likely to represent Buergers disease. It is commonest in young males who smoke heavily. Arterial occlusions/ insufficiency Arterial occlusions may occur as a result of a number of processes. The typical clinical scenarios are outlined below. Cause of occlusion Typical picture Embolus Sudden onset Depending upon level of occlusion; limb may show typical features of pain, loss of pulses and pallor. Sensory perceptive changes may also be present Thrombosis Usually known disease and prodromal symptoms e.g. claudication Disruption to flow may be incomplete If background disease process present then collaterals may be present and picture less dramatic Vasospasm May be due to Raynauds and affect extremities Symptoms are often temperature related Discolouration of the hands may occur (pale, dark, red) Symptoms improve during pregnancy (hyperdynamic circulation) Steal syndromes Occur secondary to arteriovenous fistula, or partial arterial occlusions (e.g. cervical rib) Pain and diminished pulses distal to fistula are seen Vasculitis Vessel diameter and vasculitis classification Aorta and branches Takayasu's arteritis Buergers disease Giant cell arteritis Large and medium sized arteries Buergers disease Giant cell arteritis Polyarteritis nodosa Medium sized muscular arteries Polyarteritis nodosa Wegeners granulomatosis Small muscular arteries Wegeners granulomatosis Rheumatoid vasculitis Specific conditions Takyasu's arteritis Inflammatory, obliterative arteritis affecting aorta and branches Females> Males Symptoms may include upper limb claudication Clinical findings include diminished or absent pulses ESR often affected during the acute phase Buergers disease Segmental thrombotic occlusions of the small and medium sized lower limb vessels Commonest in young male smokers Proximal pulses usually present, but pedal pulses are lost An acuter hypercellular occlusive thrombus is often present Tortuous corkscrew shaped collateral vessels may be seen on angiography Giant cell arteritis Systemic granulomatous arteritis that usually affects large and medium sized vessels Females > Males Temporal arteritis is commonest type Granulomatous lesions may be seen on biopsy (although up to 50% are normal) Polyarteritis nodosa Systemic necrotising vasculitis affecting small and medium sized muscular arteries Most common in populations with high prevalence of hepatitis B Renal disease is seen in 70% cases Angiography may show saccular or fusiform aneurysms and arterial stenoses Wegeners granulomatosis Predominantly affects small and medium sized arteries Systemic necrotising granulomatous vasculitis Cutaneous vascular lesions may be seen (ulceration, nodules and purpura) Sinus imaging may show mucosal thickening and air fluid levels

Answer 675

This patient has possible urethral injury based on the history. Urethral catheterisation is contraindicated in this situation. Lower genitourinary tract trauma Most bladder injuries occur due to blunt trauma 85% associated with pelvic fractures Easily overlooked during assessment in trauma Up to 10% of male pelvic fractures are associated with urethral or bladder injuries Types of injury Urethral injury Mainly in males Blood at the meatus (50% cases) There are 2 types: i.Bulbar rupture - most common - straddle type injury e.g. bicycles - triad signs: urinary retention, perineal haematoma, blood at the meatus ii. Membranous rupture - can be extra or intraperitoneal - commonly due to pelvic fracture - Penile or perineal oedema/ hematoma - PR: prostate displaced upwards (beware co-existing retroperitoneal haematomas as they may make examination difficult) - Investigation: ascending urethrogram - Management: suprapubic catheter (surgical placement, not percutaneously) External genitalia injuries (i.e., the penis and the scrotum) Secondary to injuries caused by penetration, blunt trauma, continence- or sexual pleasure-enhancing devices, and mutilation Bladder injury rupture is intra or extraperitoneal presents with haematuria or suprapubic pain history of pelvic fracture and inability to void: always suspect bladder or urethral injury inability to retrieve all fluid used to irrigate the bladder through a Foley catheter indicates bladder injury investigation- IVU or cystogram management: laparotomy if intraperitoneal, conservative if extraperitoneal

Answer 676

Application of below knee walking boot This is a Weber B fracture and therefore potentially unstable. Medial malleolar tenderness indicates deltoid ligament injury. As the fracture is currently undisplaced and the ankle mortise is congruent, the injury can be initially managed conservatively in a moon boot but the patient should be monitored in the outpatient clinic for fracture displacement in the first few weeks. Ankle injuries An ankle fracture relates to a fracture around the tibio-talar joint. It generally refers to a fracture involving the lateral, and/or medial and/or posterior malleolus. Pilon and Tillaux fractures are also considered to be ankle fractures, but are not covered here. Ankle fractures are common. They effect men and women in equal numbers, but men have a higher rate as young adults (sports and contact injuries), and women a higher rate post-menopausal (fragility type fracture). Osseous anatomy The ankle (or mortise) joint consists of the distal tibia (tibial plafond and posterior malleolus), the distal fibula (lateral malleolus), and the talus. The main movement at the ankle joint is plantar and dorsiflexion. Ligamentous anatomy Medial side: Deltoid ligament. This is divided into superficial and deep portions. It is the primary restraint to valgus tilting of the talus. Lateral side: Lateral ligament complex consisting from anterior to posterior of the anterior talofibular ligament (ATFL), calcaneofibular ligament (CFL), and the posterior talofibular ligament (PTFL). Together they resist valgus stress to the ankle, and are a restraint to anterior translation of the talus within the mortise joint. Syndesmosis: The syndesmosis is a ligament complex between the distal tibia and fibula, holding the two bones together. It is fundamental to the integrity of the ankle joint, and its disruption leads to instability. It consists of (from anterior to posterior) the anterior-inferior tibiofibular ligament (AITFL), the transverse tibiofibular ligament (TTFL), the interosseous membrane, and the posterior-inferior tibiofibular ligament (PITFL). Presentation and initial management Patients will present following a traumatic event with a painful, swollen ankle, and reluctance/inability to weight bear. The Ottawa rules can be applied to differentiate between an ankle fracture and sprain, but can be unreliable. In high energy injuries, management should follow ATLS principles to identify more significant injuries first. Neurovascular status of the foot should be documented, and open injuries should be excluded. If an open injury is identified, it should be managed in line with BOAST 4 principles1. If an obvious deformity exists, it should be reduced as soon as possible with appropriate analgesia or conscious sedation. Radiographs of clearly deformed or dislocated joints are not necessary, and removing the pressure on the surrounding soft tissues from the underlying bony deformity is the priority. If the fracture pattern is not clinically obvious then plain radiographs are appropriate and will guide the subsequent manipulation during plaster-of-paris below knee backslab application. Imaging AP, lateral and mortise views (20 degrees internal rotation) are essential to evaluate fracture displacement and syndesmotic injury. Decreased tibiofibular overlap, medial joint clear space and lateral talar shift all indicate a syndesmotic injury. (In subtle cases of shift, imaging the uninjured ankle can be helpful as a proportion of the population have little or no tibiotalar overlap-reference 2.) Where there is suspicion of syndesmosis involvement in the absence of radiographic evidence, stress radiographs can be diagnostic. Complex fracture patterns (and increasingly posterior malleolar fractures) are best defined using CT. Classification The most commonly used classifications are Lauge-Hansen and Danis-Weber. Lauge-Hansen Comprises two parts: first part is the foot position, and the second part is the force applied. Useful for understanding the forces involved and therefore predict the ligamentous or bony injury. Results in four injury patterns: Supination - Adduction (SA) - 10-20% Supination - External rotation (SER) - 40-75% Pronation - Abduction (PA) - 5-20% Pronation - External rotation (PER) - 5-20% Not often used in clinical practice but good for understanding the principles of ankle fracture. Danis-Weber Commonly used. Based on the level of the fibula fracture in relation to the syndesmosis. The more proximal, the greater the risk of syndesmotic injury and therefore fracture instability. A - fracture below the level of the syndesmosis B - fracture at the level of the syndesmosis / level of the tibial plafond C - fracture above the level of the syndesmosis. This includes Maisonneuve fractures (proximal fibula fracture), which can be associated with ankle instability. Beware the high fibula fracture - it may be an ankle fracture! The Weber classification is based purely on the the lateral side. All injuries can include a medial or posterior bony or ligamentous injury which also dictates fracture stability (bimalleolar and trimalleolar fractures are more unstable). Treatment When deciding upon treatment for an ankle fracture, one must consider both the fracture and the patient. Diabetic patients and smokers are at greater risk of post-operative complication, especially wound problems and infection. Likewise, the long term outcome of post-traumatic arthritis from a malunited ankle fracture is extremely important for a young patient, but not as relevant in the elderly. Therefore, normal surgical decision processes apply as with all fractures. Defining stability of an ankle fracture underpins the treatment decision. Weber A - Unimalleolar Weber A Weber fractures by definition are stable and therefore can be mobilised fully weight bearing in an ankle boot. Weber C - Fractures tend to include syndesmotic disruption and are usually bimalleolar (either bony or ligamentous). They are therefore unstable and usually require operative fixation. In addition to the fracture fixation, the syndesmosis usually requires reconstruction/augmentation with screws to restore the joint integrity and function. Weber B - B fractures vary greatly. They can be part of a trimalleolar injury and therefore extremely unstable, requiring fixation. Alternatively, a uni-malleolar Weber B fracture can be a stable injury, and therefore mobilised immediately in an ankle boot. Defining the stability can be challenging, and often involves stress radiographs, or a trial of mobilisation and repeat radiographs. However, treating undisplaced ankle fractures in a below knee plaster, non-weight bearing for six weeks is still widely practised, and a safe approach. When operative fixation is appropriate, it is usually via open reduction and internal fixation using plates and screws. It must be carried out when soft tissue swelling has settled in order to minimise the risk of wound problems. This can often take a week to settle. The use of fibula nails is expanding, but is not yet mainstream. Ankle fractures can also be treated with external fixation, or with a hind foot nail in patients who need fixation but where soft tissue or bone quality is poor. Post operative management Ankle fractures generally take 6 weeks to unite enough to prevent secondary displacement. This is therefore an appropriate time period to keep a cast on in a conservatively managed patient. Weight bearing post-operatively depends on the quality of the fixation and bone quality, and preference varies between surgeons, ranging from aggressive early mobilisation to a period of non-weight bearing. Return to activities takes approximately three months, and often requires assistance of a physiotherapist to improve range-of-movement and muscle strengthening. References 1. http://www.boa.ac.uk/publications/boa-standards-trauma-boasts/ 2. Shah AS, Kadakia AR, Tan GJ, Karadsheh MS, Wolter TD, Sabb B. Radiographic evaluation of the normal distal tibiofibular syndesmosis. Foot Ankle Int. 2012;33(10):870-6

Answer 677

The flattened appearance of the face is a classical description of the dish/pan face associated with Le fort fracture 2 or 3 of the maxilla. Craniomaxillofacial injuries Craniomaxillofacial injuries in the UK are due to: Interpersonal violence (52%) Motor vehicle accidents (16%) Sporting injuries (19%) Falls (11%) Le Fort Fractures Grade Feature Le Fort 1 The fracture extends from the nasal septum to the lateral pyriform rims, travels horizontally above the teeth apices, crosses below the zygomaticomaxillary junction, and traverses the pterygomaxillary junction to interrupt the pterygoid plates. Le Fort 2 These fractures have a pyramidal shape and extend from the nasal bridge at or below the nasofrontal suture through the frontal process of the maxilla, inferolaterally through the lacrimal bones and inferior orbital floor and rim through or near the inferior orbital foramen, and inferiorly through the anterior wall of the maxillary sinus; it then travels under the zygoma, across the pterygomaxillary fissure, and through the pterygoid plates. Le Fort 3 These fractures start at the nasofrontal and frontomaxillary sutures and extend posteriorly along the medial wall of the orbit through the nasolacrimal groove and ethmoid bones. The thicker sphenoid bone posteriorly usually prevents continuation of the fracture into the optic canal. Instead, the fracture continues along the floor of the orbit along the inferior orbital fissure and continues superolaterally through the lateral orbital wall, through the zygomaticofrontal junction and the zygomatic arch. Intranasally, a branch of the fracture extends through the base of the perpendicular plate of the ethmoid, through the vomer, and through the interface of the pterygoid plates to the base of the sphenoid. This type of fracture predisposes the patient to CSF rhinorrhea more commonly than the other types. Ocular injuries Superior orbital fissure syndrome Severe force to the lateral wall of the orbit resulting in compression of neurovascular structures. Results in : Complete opthalmoplegia and ptosis (Cranial nerves 3, 4, 6 and nerve to levator palpebrae superioris) Relative afferent pupillary defect Dilatation of the pupil and loss of accommodation and corneal reflexes Altered sensation from forehead to vertex (frontal branch of trigeminal nerve) Orbital blow out fracture Typically occurs when an object of slightly larger diameter than the orbital rim strikes the incompressible eyeball. The bone fragment is displaced downwards into the antral cavity, remaining attached to the orbital periosteum. Periorbital fat may be herniated through the defect, interfering with the inferior rectus and inferior oblique muscles which are contained within the same fascial sheath. This prevents upward movement and outward rotation of the eye and the patient experiences diplopia on upward gaze. The initial bruising and swelling may make assessment difficult and patients should usually be reviewed 5 days later. Residual defects may require orbital floor reconstruction. Nasal Fractures Common injury Ensure new and not old deformity Control epistaxis CSF rhinorrhoea implies that the cribriform plate has been breached and antibiotics will be required. Usually best to allow bruising and swelling to settle and then review patient clinically. Major persistent deformity requires fracture manipulation, best performed within 10 days of injury. Retrobulbar haemorrhage Rare but important ocular emergency. Presents with: Pain (usually sharp and within the globe) Proptosis Pupil reactions are lost Paralysis (eye movements lost) Visual acuity is lost (colour vision is lost first) May be the result of Le Fort type facial fractures. Management: Mannitol 1g/Kg as 20% infusion, Osmotic diuretic, Contra-indicated in congestive heart failure and pulmonary oedema Acetazolamide 500mg IV, (Monitor FBC/U+E) Reduces aqueous pressure by inhibition of carbonic anhydrase (used in glaucoma) Dexamethasone 8mg orally or intravenously In a traumatic setting an urgent cantholysis may be needed prior to definitive surgery. Consider Papaverine 40mg smooth muscle relaxant Dextran 40 500mls IV improves perfusion

Answer 678

DALM lesions complicating ulcerative colitis should be managed with panproctocolectomy. An anterior resection is inadequate since it will only remove the rectum and ulcerative colitis affects the entire colon. Since many will be associated with invasion a snare polypectomy is not sufficient either. Colonic lesions - DALM The term DALM lesion refers to a Dysplasia Associated Lesion or Mass. They may complicate dysplasia occurring in patients with longstanding ulcerative colitis. They have a high incidence of invasive foci. When they complicate longstanding ulcerative colitis, they should be treated by panproctocolectomy.

Answer 679

Hypovolaemia is the most likely cause for oliguria and a fluid challenge is the most appropriate action. Blind administration of inotropes to hypovolaemic patients is unwise, with the possible exception of cardiac patients. Hypovolaemia and the surgical patient Hypovolaemia often represents the end point of multiple pathological processes. It may be divided into the following categories; overt compensated hypovolaemia, covert compensated hypovolaemia and decompensated hypovolaemia. Of these three categories the covert compensated subtype of hypovolaemia remains the commonest and is accounted for by the fact that class I shock will often produce no overtly discernible clinical signs. This is due, in most cases, to a degree of splanchnic autotransfusion. The most useful diagnostic test for detection of covert compensated hypovolaemia remains urinanalysis. This often shows increased urinary osmolality and decreased sodium concentration. In overt compensated hypovolaemia the blood pressure is maintained although other haemodynamic parameters may be affected. This correlates to class II shock. In most cases assessment can be determined clinically. Where underlying cardiopulmonary disease may be present the placement of a CVP line may guide fluid resuscitation. Severe pulmonary disease may produce discrepancies between right and left atrial filling pressures. This problem was traditionally overcome through the use of Swann-Ganz catheters. Untreated, hypovolaemia may ultimately become uncompensated with resultant end organ dysfunction. Microvascular hypoperfusion may result in acidosis with a subsequent myocardial depressive effect, thereby producing a vicious circle. The treatment of hypovolaemia is with intravenous fluids. In the first instance a fluid challenge such as the rapid infusion of 250ml of crystalloid will often serve as both a diagnostic and resuscitative measure. In the event that this fails to produce the desired response the patient will need to be re-evaluated clinically. More fluid may be needed. However, it is important not to overlook mechanical ureteric obstruction in the anuric, normotensive patient.

Answer 680

Renal adenocarcinoma are the most common renal tumours. These will typically affect the renal parenchyma. Transitional cell carcinoma will usually affect urothelial surfaces. Nephroblastoma would be very rare in this age group. Renal adenocarcinoma may produce cannon ball metastasis in the lung which cause haemoptysis, this is not a feature of PKD. Renal tumours Renal cell carcinoma Renal cell carcinoma is an adenocarcinoma of the renal cortex and is believed to arise from the proximal convoluted tubule. They are usually solid lesions, up to 20% may be multifocal, 20% may be calcified and 20% may have either a cystic component or be wholly cystic. They are often circumscribed by a pseudocapsule of compressed normal renal tissue. Spread may occur either by direct extension into the adrenal gland, renal vein or surrounding fascia. More distant disease usually occurs via the haematogenous route to lung, bone or brain. Renal cell carcinoma comprise up to 85% of all renal malignancies. Males are more commonly affected than females and sporadic tumours typically affect patients in their sixth decade. Patients may present with a variety of symptoms including; haematuria (50%), loin pain (40%), mass (30%) and up to 25% may have symptoms of metastasis.Less than 10% have the classic triad of haematuria, pain and mass. Investigation Many cases will present as haematuria and be discovered during diagnostic work up. Benign renal tumours are rare, so renal masses should be investigated with multislice CT scanning. Most tumours are also characterised with an arterial phase CT, particularly if they may be suitable for partial nephrectomy. CT scanning of the chest and abdomen to detect distant disease should also be undertaken. Routine bone scanning is not indicated in the absence of symptoms. Biopsy should not be performed when a nephrectomy is planned but is mandatory before any ablative therapies are undertaken. Assessment of the functioning of the contra lateral kidney. Management T1 lesions may be managed by partial nephrectomy and this gives equivalent oncological results to total radical nephrectomy. Partial nephrectomy may also be performed when there is inadequate reserve in the remaining kidney. Ablative techniques may also be considered for small T1 lesions in unfit patients. In general, outcomes are less favorable than with surgical resection. For T2 lesions and above a radical nephrectomy is standard practice and this may be performed via a laparoscopic or open approach. Preoperative embolisation is not indicated nor is resection of uninvolved adrenal glands. During surgery early venous control is mandatory to avoid shedding of tumour cells into the circulation. Patients with completely resected disease do not benefit from adjuvant therapy with either chemotherapy or biological agents. These should not be administered outside the setting of clinical trials. Patients with transitional cell cancer will require a nephroureterectomy with disconnection of the ureter at the bladder. References Capitanio U, Montorsi F. Renal cancer. Lancet. 2016 Feb 27;387(10021):894-906. Capitanio U et al. Epidemiology of Renal Cell Carcinoma. Eur Urol. 2019 Jan;75(1):74-84.

Answer 681

These lesions are often extensive and superficial. Shave excision will suffice, material must be sent for histology. Skin Diseases Skin lesions may be referred for surgical assessment, but more commonly will come via a dermatologist for definitive surgical management. Skin malignancies include basal cell carcinoma, squamous cell carcinoma and malignant melanoma. Basal Cell Carcinoma Most common form of skin cancer. Commonly occur on sun exposed sites apart from the ear. Sub types include nodular, morphoeic, superficial and pigmented. Typically slow growing with low metastatic potential. Standard surgical excision, topical chemotherapy and radiotherapy are all successful. As a minimum a diagnostic punch biopsy should be taken if treatment other than standard surgical excision is planned. Squamous Cell Carcinoma Again related to sun exposure. May arise in pre - existing solar keratoses. May metastasize if left. Immunosupression (e.g. following transplant), increases risk. Wide local excision is the treatment of choice and where a diagnostic excision biopsy has demonstrated SCC, repeat surgery to gain adequate margins may be required. Malignant Melanoma The main diagnostic features (major criteria): Change in size Change in shape Change in colour Secondary features (minor criteria) Diameter >6mm Inflammation Oozing or bleeding Altered sensation Treatment Suspicious lesions should undergo excision biopsy. The lesion should be removed completely as incision biopsy can make subsequent histopathological assessment difficult. Once the diagnosis is confirmed the pathology report should be reviewed to determine whether further re-excision of margins is required (see below): Margins of excision-Related to Breslow thickness Lesions 0-1mm thick 1cm Lesions 1-2mm thick 1- 2cm (Depending upon site and pathological features) Lesions 2-4mm thick 2-3 cm (Depending upon site and pathological features) Lesions >4 mm thick 3cm Marsden J et al. Revised UK guidelines for management of Melanoma. Br J Dermatol 2010 163:238-256. Further treatments such as sentinel lymph node mapping, isolated limb perfusion and block dissection of regional lymph node groups should be selectively applied. Kaposi Sarcoma Tumour of vascular and lymphatic endothelium. Purple cutaneous nodules. Associated with immuno supression. Classical form affects elderly males and is slow growing. Immunosupression form is much more aggressive and tends to affect those with HIV related disease. Non malignant skin disease Dermatitis Herpetiformis Chronic itchy clusters of blisters. Linked to underlying gluten enteropathy (coeliac disease). Dermatofibroma Benign lesion. Firm elevated nodules. Usually history of trauma. Lesion consists of histiocytes, blood vessels and fibrotic changes. Pyogenic granuloma Overgrowth of blood vessels. Red nodules. Usually follow trauma. May mimic amelanotic melanoma. Acanthosis nigricans Brown to black, poorly defined, velvety hyperpigmentation of the skin. Usually found in body folds such as the posterior and lateral folds of the neck, the axilla, groin, umbilicus, forehead, and other areas. The most common cause of acanthosis nigricans is insulin resistance, which leads to increased circulating insulin levels. Insulin spillover into the skin results in its abnormal increase in growth (hyperplasia of the skin). In the context of a malignant disease, acanthosis nigricans is a paraneoplastic syndrome and is then commonly referred to as acanthosis nigricans maligna. Involvement of mucous membranes is rare and suggests a coexisting malignant condition.

Answer 682

Warthins tumours are most common in elderly smokers. They have a relatively benign and indolent course. Parotid gland clinical Benign neoplasms Up to 80% of all salivary gland tumours occur in the parotid gland and up to 80% of these are benign. There is no consistent correlation between the rate of growth and the malignant potential of the lesion. However, benign tumours should not invade structures such as the facial nerve. With the exception of Warthins tumours, they are commoner in women than men. The median age of developing a lesion is in the 5th decade of life. Benign tumour types Tumour type Features Benign pleomorphic adenoma or benign mixed tumor Most common parotid neoplasm (80%) Proliferation of epithelial and myoepithelial cells of the ducts and an increase in stromal components Slow growing, lobular, and not well encapsulated Recurrence rate of 1-5% with appropriate excision (parotidectomy) Recurrence possibly secondary to capsular disruption during surgery Malignant degeneration occurring in 2-10% of adenomas observed for long periods, with carcinoma ex-pleomorphic adenoma occurring most frequently as adenocarcinoma Warthin tumor (papillary cystadenoma lymphoma or adenolymphoma) Second most common benign parotid tumor (5%) Most common bilateral benign neoplasm of the parotid Marked male as compared to female predominance Occurs later in life (sixth and seventh decades) Presents as a lymphocytic infiltrate and cystic epithelial proliferation May represent heterotopic salivary gland epithelial tissue trapped within intraparotid lymph nodes Incidence of bilaterality and multicentricity of 10% Malignant transformation rare (almost unheard of) Monomorphic adenoma Account for less than 5% of tumours Slow growing Consist of only one morphological cell type (hence term mono) Include; basal cell adenoma, canalicular adenoma, oncocytoma, myoepitheliomas Haemangioma Should be considered in the differential of a parotid mass in a child Accounts for 90% of parotid tumours in children less than 1 year of age Hypervascular on imaging Spontaneous regression may occur and malignant transformation is almost unheard of Malignant salivary gland tumours Types of malignancy Mucoepidermoid carcinoma 30% of all parotid malignancies Usually low potential for local invasiveness and metastasis (depends mainly on grade) Adenoid cystic carcinoma Unpredictable growth pattern Tendency for perineural spread Nerve growth may display skip lesions resulting in incomplete excision Distant metastasis more common (visceral rather than nodal spread) 5 year survival 35% Mixed tumours Often a malignancy occurring in a previously benign parotid lesion Acinic cell carcinoma Intermediate grade malignancy May show perineural invasion Low potential for distant metastasis 5 year survival 80% Adenocarcinoma Develops from secretory portion of gland Risk of regional nodal and distant metastasis 5 year survival depends upon stage at presentation, may be up to 75% with small lesions with no nodal involvement Lymphoma Large rubbery lesion, may occur in association with Warthins tumours Diagnosis should be based on regional nodal biopsy rather than parotid resection Treatment is with chemotherapy (and radiotherapy) Diagnostic evaluation Plain x-rays may be used to exclude calculi Sialography may be used to delineate ductal anatomy FNAC is used in most cases Superficial parotidectomy may be either diagnostic or therapeutic depending upon the nature of the lesion Where malignancy is suspected the primary approach should be definitive resection rather than excisional biopsy CT/ MRI may be used in cases of malignancy for staging primary disease Treatment For nearly all lesions this consists of surgical resection, for benign disease this will usually consist of a superficial parotidectomy. For malignant disease a radical or extended radical parotidectomy is performed. The facial nerve is included in the resection if involved. The need for neck dissection is determined by the potential for nodal involvement. Other parotid disorders HIV infection Lymphoepithelial cysts associated with HIV occur almost exclusively in the parotid Typically presents as bilateral, multicystic, symmetrical swelling Risk of malignant transformation is low and management usually conservative Sjogren syndrome Autoimmune disorder characterised by parotid enlargement, xerostomia and keratoconjunctivitis sicca 90% of cases occur in females Second most common connective tissue disorder Bilateral, non tender enlargement of the gland is usual Histologically, the usual findings are of a lymphocytic infiltrate in acinar units and epimyoepithelial islands surrounded by lymphoid stroma Treatment is supportive There is an increased risk of subsequent lymphoma Sarcoid Parotid involvement occurs in 6% of patients with sarcoid Bilateral in most cases Gland is not tender Xerostomia may occur Management of isolated parotid disease is usually conservative

Answer 683

The question asks for the incorrect association. Certain ethnic groups are at increased risk of keloid scar formation. Severe burns can be complicated by wound contracture that requires surgery. Radiotherapy and zinc deficiency are both recognized risk factors for delayed healing. However, fully healed wounds cannot breakdown with chemotherapy and this statement is therefore incorrect and represents the correct answer. Wound healing Surgical wounds are either incisional or excisional and either clean, clean contaminated or dirty. Although the stages of wound healing are broadly similar their contributions will vary according to the wound type. The main stages of wound healing include: Haemostasis Minutes to hours following injury Vasospasm in adjacent vessels, platelet plug formation and generation of fibrin rich clot. Inflammation Typically days 1-5 Neutrophils migrate into wound (function impaired in diabetes). Growth factors released, including basic fibroblast growth factor and vascular endothelial growth factor. Fibroblasts replicate within the adjacent matrix and migrate into wound. Macrophages and fibroblasts couple matrix regeneration and clot substitution. Regeneration Typically days 7 to 56 Platelet derived growth factor and transformation growth factors stimulate fibroblasts and epithelial cells. Fibroblasts produce a collagen network. Angiogenesis occurs and wound resembles granulation tissue. Remodeling From 6 weeks to 1 year Longest phase of the healing process and may last up to one year (or longer). During this phase fibroblasts become differentiated (myofibroblasts) and these facilitate wound contraction. Collagen fibres are remodeled. Microvessels regress leaving a pale scar. The above description represents an idealised scenario. A number of diseases may distort this process. Neovascularisation is an important early process. Endothelial cells may proliferate in the wound bed and recanalise to form a vessel. Vascular disease, shock and sepsis can all compromise microvascular flow and impair healing. Conditions such as jaundice will impair fibroblast synthetic function and immunity with a detrimental effect in most parts of the healing process. Problems with scars: Hypertrophic scars Excessive amounts of collagen within a scar. Nodules may be present histologically containing randomly arranged fibrils within and parallel fibres on the surface. The tissue itself is confined to the extent of the wound itself and is usually the result of a full thickness dermal injury. They may go on to develop contractures. Keloid scars Excessive amounts of collagen within a scar. Typically a keloid scar will pass beyond the boundaries of the original injury. They do not contain nodules and may occur following even trivial injury. They do not regress over time and may recur following removal. Drugs which impair wound healing: Non steroidal anti inflammatory drugs Steroids Immunosupressive agents Anti neoplastic drugs Closure Delayed primary closure is the anatomically precise closure that is delayed for a few days but before granulation tissue becomes macroscopically evident. Secondary closure refers to either spontaneous closure or to surgical closure after granulation tissue has formed.

Answer 684

The internal carotid does not have any branches in the neck. Internal carotid artery The internal carotid artery is formed from the common carotid opposite the upper border of the thyroid cartilage. It extends superiorly to enter the skull via the carotid canal. From the carotid canal it then passes through the cavernous sinus, above which it divides into the anterior and middle cerebral arteries. Relations in the neck Posterior Longus capitis Pre-vertebral fascia Sympathetic chain Superior laryngeal nerve Medially External carotid (near origin) Wall of pharynx Ascending pharyngeal artery Laterally Internal jugular vein (moves posteriorly at entrance to skull) Vagus nerve (most posterolaterally) Anteriorly Sternocleidomastoid Lingual and facial veins Hypoglossal nerve Relations in the carotid canal Internal carotid plexus Cochlea and middle ear cavity Trigeminal ganglion (superiorly) Leaves canal lies above the foramen lacerum Path and relations in the cranial cavity The artery bends sharply forwards in the cavernous sinus, the aducens nerve lies close to its inferolateral aspect. The oculomotor, trochlear, opthalmic and, usually, the maxillary nerves lie in the lateral wall of the sinus. Near the superior orbital fissure it turns posteriorly and passes postero-medially to pierce the roof of the cavernous sinus inferior to the optic nerve. It then passes between the optic and oculomotor nerves to terminate below the anterior perforated substance by dividing into the anterior and middle cerebral arteries. Branches Anterior and middle cerebral artery Ophthalmic artery Posterior communicating artery Anterior choroid artery Meningeal arteries Hypophyseal arteries

Answer 685

Innervates: all intrinsic larynx muscles (excluding cricothyroid) The external branch of the superior laryngeal nerve innervates the cricothyroid muscle. Recurrent laryngeal nerve Branch of the vagus nerve Path Right Arises anterior to the subclavian artery and ascends obliquely next to the trachea, behind the common carotid artery It is either anterior or posterior to the inferior thyroid artery Left Arises left to the arch of the aorta Winds below the aorta Ascends along the side of the trachea Then both Pass in a groove between the trachea and oesophagus Enters the larynx behind the articulation between the thyroid cartilage and cricoid Distributed to larynx muscles Branches to Cardiac plexus Mucous membrane and muscular coat of the oesophagus and trachea Innervates Intrinsic larynx muscles (excluding cricothyroid)

Answer 686

Bilious vomiting in neonates is a surgical emergency and is intestinal malrotation and volvulus until otherwise proven. It is investigated with an upper GI contrast study. Contrast should be seen to exit the stomach and the location of the DJ flexure is noted (it lies to the left of the midline). If this is not the case, or the study is inconclusive, a laparotomy is performed. Intestinal malrotation in neonates Normal embryology During the fourth week of embryogenesis the intestine moves into the abdomen via the base of the umbilicus. Through a combination of foetal growth and bowel maturation the bowel resides in the abdominal cavity and undergoes a 270o counterclockwise twist. At the conclusion of this process the ligament of Treitz lies to the left of the spine and the caecum in the right lower quadrant. Malrotation occurs when the rotational process described is incomplete. Typically the duodenal loop lies to the left of the caecum and therefore lacks 90 o of its 270o rotation. It becomes fixed in this position with peritoneal attachments (Ladds bands). Symptoms Bilious vomiting is the cardinal symptom and sign. In most cases there are no antecedent symptoms. If untreated then gut perfusion may be impaired with resultant development of further symptoms. Diagnosis The main problem is that the infant develops mid gut volvulus. In this situation the bowel undergoes a 720o twist, the bowel viability depends upon a narrow mesentery containing the superior mesenteric artery. To ascertain whether this has occurred the two main tests include an abdominal ultrasound scan to determine the relationship between the superior mesenteric artery and vein (normally SMA lies to the left of the SMV). This test is complemented with an upper GI contrast series and this aims to establish that the DJ flexure is correctly sited to the left of the vertebral bodies. Treatment Laparotomy and division of adhesional bands (Ladds procedure). The division of the congenital adhesions allows widening of the small bowel mesentery. The bowel is untwisted and assessed for viability. The bowel is returned to the abdominal cavity in the non rotated fashion with the small bowel on the right hand side and the large bowel on the left, the caecum is positioned in the left upper quadrant. Because the caecum is located in this new location many surgeons will also perform an appendicectomy due to the diagnostic difficulty posed in diagnosing appendicitis in this group of patients.

Answer 687

Improved results when the degloved segment is left in situ as a temporary closure Degloving injuries typically involve extremities and are usually friction injuries e.g. arm being run over. There is abnormal motility of the overlying skin, pallor, loss of sensation. Early treatment is key and should involve skin grafting which may use the degloved segment. This however, should be formally prepared for the role and simple compression bandaging gives poor results. Wound healing Surgical wounds are either incisional or excisional and either clean, clean contaminated or dirty. Although the stages of wound healing are broadly similar their contributions will vary according to the wound type. The main stages of wound healing include: Haemostasis Minutes to hours following injury Vasospasm in adjacent vessels, platelet plug formation and generation of fibrin rich clot. Inflammation Typically days 1-5 Neutrophils migrate into wound (function impaired in diabetes). Growth factors released, including basic fibroblast growth factor and vascular endothelial growth factor. Fibroblasts replicate within the adjacent matrix and migrate into wound. Macrophages and fibroblasts couple matrix regeneration and clot substitution. Regeneration Typically days 7 to 56 Platelet derived growth factor and transformation growth factors stimulate fibroblasts and epithelial cells. Fibroblasts produce a collagen network. Angiogenesis occurs and wound resembles granulation tissue. Remodeling From 6 weeks to 1 year Longest phase of the healing process and may last up to one year (or longer). During this phase fibroblasts become differentiated (myofibroblasts) and these facilitate wound contraction. Collagen fibres are remodeled. Microvessels regress leaving a pale scar. The above description represents an idealised scenario. A number of diseases may distort this process. Neovascularisation is an important early process. Endothelial cells may proliferate in the wound bed and recanalise to form a vessel. Vascular disease, shock and sepsis can all compromise microvascular flow and impair healing. Conditions such as jaundice will impair fibroblast synthetic function and immunity with a detrimental effect in most parts of the healing process. Problems with scars: Hypertrophic scars Excessive amounts of collagen within a scar. Nodules may be present histologically containing randomly arranged fibrils within and parallel fibres on the surface. The tissue itself is confined to the extent of the wound itself and is usually the result of a full thickness dermal injury. They may go on to develop contractures.

Answer 688

The Monroe-Kelly Doctrine assumes that the cranial cavity is a rigid box. In children with non fused fontanells this is not the case. Applied neurophysiology Pressure within the cranium is governed by the Monroe-Kelly doctrine. This considers the skull as a closed box. Increases in mass can be accommodated by loss of CSF. Once a critical point is reached (usually 100- 120ml of CSF lost) there can be no further compensation and ICP rises sharply. The next step is that pressure will begin to equate with MAP and neuronal death will occur. Herniation will also accompany this process. The CNS can autoregulate its own blood supply. Vaso constriction and dilatation of the cerebral blood vessels is the primary method by which this occurs. Extremes of blood pressure can exceed this capacity resulting in risk of stroke. Other metabolic factors such as hypercapnia will also cause vasodilation, which is of importance in ventilating head injured patients. The brain can only metabolise glucose, when glucose levels fall, consciousness will be impaired.

Answer 689

Glioblastoma is rare in children. Ependymoma account for up to 33% of CNS tumours in those under age of 3. They commonly arise in the 4th ventricle and can grow through the foramina of Luschka and Magendie CNS tumours 60% = Glioma and metastatic disease 20% = Meningioma 10% = Pituitary lesions In paediatric practice medulloblastomas (neuroectodermal tumours) were the commonest lesions, astrocytomas now account for the majority. Tumours arising in right temporal and frontal lobe may reach considerable size before becoming symptomatic. Whereas tumours in the speech and visual areas will typically produce early symptoms. Most paediatric CNS tumours are infratentorial Most adult CNS tumours are supratentorial Diagnosis MRI Scanning provides the best resolution. Treatment Usually surgery, even if tumour cannot be completely resected conditions such as rising ICP can be addressed with tumour debulking and survival and quality of life prolonged. Curative surgery can usually be undertaken with lesions such as meningiomas. Gliomas have a marked propensity to invade normal brain and resection of these lesions is nearly always incomplete.

Answer 690

Loss of the median nerve will result in loss of function of the flexor muscles. However, flexor carpi ulnaris will still function and produce ulnar deviation and some residual wrist flexion. High median nerve lesions result in complete loss of flexion at the thumb joint. Median nerve The median nerve is formed by the union of a lateral and medial root respectively from the lateral (C5,6,7) and medial (C8 and T1) cords of the brachial plexus; the medial root passes anterior to the third part of the axillary artery. The nerve descends lateral to the brachial artery, crosses to its medial side (usually passing anterior to the artery). It passes deep to the bicipital aponeurosis and the median cubital vein at the elbow. It passes between the two heads of the pronator teres muscle, and runs on the deep surface of flexor digitorum superficialis (within its fascial sheath). Near the wrist it becomes superficial between the tendons of flexor digitorum superficialis and flexor carpi radialis, deep to palmaris longus tendon. It passes deep to the flexor retinaculum to enter the palm, but lies anterior to the long flexor tendons within the carpal tunnel. Branches Region Branch Upper arm No branches, although the nerve commonly communicates with the musculocutaneous nerve Forearm Pronator teres Pronator quadratus Flexor carpi radialis Palmaris longus Flexor digitorum superficialis Flexor pollicis longus Flexor digitorum profundus (only the radial half) Distal forearm Palmar cutaneous branch Hand (Motor) Motor supply (LOAF) Lateral 2 lumbricals Opponens pollicis Abductor pollicis brevis Flexor pollicis brevis Hand (Sensory) Over thumb and lateral 2 ½ fingers On the palmar aspect this projects proximally, on the dorsal aspect only the distal regions are innervated with the radial nerve providing the more proximal cutaneous innervation. Patterns of damage Damage at wrist e.g. carpal tunnel syndrome paralysis and wasting of thenar eminence muscles and opponens pollicis (ape hand deformity) sensory loss to palmar aspect of lateral (radial) 2 ½ fingers Damage at elbow, as above plus: unable to pronate forearm weak wrist flexion ulnar deviation of wrist Anterior interosseous nerve (branch of median nerve) leaves just below the elbow results in loss of pronation of forearm and weakness of long flexors of thumb and index finger

Answer 691

The coeliac axis lies at T12, it takes an almost horizontal angle off the aorta. It has three major branches. Abdominal aortic branches Branches Level Paired Type Inferior phrenic T12 (Upper border) Yes Parietal Coeliac T12 No Visceral Superior mesenteric L1 No Visceral Middle suprarenal L1 Yes Visceral Renal L1-L2 Yes Visceral Gonadal L2 Yes Visceral Lumbar L1-L4 Yes Parietal Inferior mesenteric L3 No Visceral Median sacral L4 No Parietal Common iliac L4 Yes Terminal

Answer 692

The correct answer is bicipital aponeurosis. The bicipital aponeurosis is a thin sheet of connective tissue that extends from the biceps brachii muscle and covers the brachial artery and median nerve in the cubital fossa1. It separates these structures from the median cubital vein, which is a superficial vein that connects the cephalic vein (located laterally) and the basilic vein (located medially)2. The other options are muscles that are either located outside the cubital fossa or form the floor of the fossa, but do not separate the cephalic vein and the brachial artery.

Answer 693

Distant disease in patients with oesophageal cancer is a contra indication to a resectional strategy and downstaging with chemotherapy is not routinely undertaken in this age group as the results are poor. An expanding stent will provide rapid and durable palliation. Oesophageal cancer - treatment Treatments for SCC's and adenocarcinomas of the oesophagus differ. This is primarily due to the positive outcomes that are observed when localised SCC's (particularly of the proximal oesophagus) are treated with radical chemoradiotherapy (obviating the need for surgery). Only those patients whose staging investigations are negative for metastatic disease should be considered for surgery. Surgical options Endoscopic mucosal resection Treatment for early localised adenocarcinoma of the distal oesophagus. Survival mirrors that of surgical resection for Tis and T1 disease Transhiatal oeosphagectomy Most commonly used for junctional (type II) (1) tumours where limited thoracic oesophageal resection is required. Less morbidity than two field oesophagectomy Ivor Lewis oesophagectomy Two stage approach for middle and distal tumours. Very commonly performed, intrathoracic anastomosis will result in mediastinitis in event of anastomotic leak. Lower incidence of recurrent laryngeal nerve injury McKeown oesophagectomy Three field approach, may be useful for proximal tumours. Anastomotic leakage is less serious. Higher incidence of recurrent laryngeal nerve injury Neoadjuvent and adjuvent treatment Neoadjuvent radiotherapy alone prior to resection confers little benefit and is not routinely performed (2) Preoperative chemotherapy is associated with a survival advantage (OE02 trial) Peri operative (pre and post operative) chemotherapy confers a survival advantage in junctional tumours Post operative chemotherapy is not generally recommended following oesophageal resections outside clinical trials Palliation strategies Combination chemotherapy improves quality of life and survival in non operable disease (3) Trastuzumab may improve survival in patients with HER 2 positive tumours Oesophageal intubation with self expanding metal stents is the treatment of choice in patients with occluding tumours >2cm from the cricopharyngeus Covered metal stents are useful in cases of malignant fistulas Laser therapy and argon plasma coagulation may be useful as therapies for tumour overgrowth and bleeding Photodynamic therapy and ethanol injections confer little benefit and should not be routinely used References 1. Hulscher JB, van Sandick JW, de Boer AG, et al. Extended transthoracic resection compared with limited transhiatal resection for adenocarcinoma of the esophagus. N Engl J Med 2002;347:1662-9 2. Deng HY, Wang WP, Wang YC, Hu WP, Ni PZ, Lin YD, Chen LQ. Neoadjuvant chemoradiotherapy or chemotherapy? A comprehensive systematic review and meta-analysis of the options for neoadjuvant therapy for treating oesophageal cancer. Eur J Cardiothorac Surg. 2017 Mar 1;51(3):421-431. doi: 10.1093/ejcts/ezw315. 3.Khin MO, Bromham N, Harrison M, Eadon H. Assessment and management of oesophago-gastric cancer: summary of NICE guidance. BMJ. 2018 Jan 29;360:k213. doi: 10.1136/bmj.k213.

Answer 694

Seminoma is the commonest type of testicular tumour and is more common in males aged between 30-40 years. Classical seminoma is the commonest subtype and histology shows lymphocytic stromal infiltrate. Other subtypes include: 1. Spermatocytic: tumour cells resemble spermatocytes. Excellent prognosis. 2. Anaplastic 3. Syncytiotrophoblast giant cells: β HCG present in cells A teratoma is more common in males aged 20-30 years. Testicular disorders Testicular cancer Testicular cancer is the most common malignancy in men aged 20-30 years. Around 95% of cases of testicular cancer are germ-cell tumours. Germ cell tumours may essentially be divided into: Tumour type Key features Tumour markers Pathology Seminoma Commonest subtype (50%) Average age at diagnosis = 40 Even advanced disease associated with 5 year survival of 73% AFP usually normal HCG elevated in 10% seminomas Lactate dehydrogenase; elevated in 10-20% seminomas (but also in many other conditions) Sheet like lobular patterns of cells with substantial fibrous component. Fibrous septa contain lymphocytic inclusions and granulomas may be seen. Non seminomatous germ cell tumours (42%) Teratoma Yolk sac tumour Choriocarcinoma Mixed germ cell tumours (10%) Younger age at presentation =20-30 years Advanced disease carries worse prognosis (48% at 5 years) Retroperitoneal lymph node dissection may be needed for residual disease after chemotherapy AFP elevated in up to 70% of cases HCG elevated in up to 40% of cases Other markers rarely helpful Risk factors for testicular cancer Cryptorchidism Infertility Family history Klinefelter's syndrome Mumps orchitis Features A painless lump is the most common presenting symptom Pain may also be present in a minority of men Other possible features include hydrocele, gynaecomastia Diagnosis Ultrasound is first-line CT scanning of the chest/ abdomen and pelvis is used for staging Tumour markers (see above) should be measured Management Orchidectomy (Inguinal approach) Chemotherapy and radiotherapy may be given depending on staging Abdominal lesions >1cm following chemotherapy may require retroperitoneal lymph node dissection. Prognosis is generally excellent 5 year survival for seminomas is around 95% if Stage I 5 year survival for teratomas is around 85% if Stage I Benign disease Epididymo-orchitis Acute epididymitis is an acute inflammation of the epididymis, often involving the testis and usually caused by bacterial infection. Infection spreads from the urethra or bladder. In men <35 years, gonorrhoea or chlamydia are the usual infections. Amiodarone is a recognised non infective cause of epididymitis, which resolves on stopping the drug. Tenderness is usually confined to the epididymis, which may facilitate differentiating it from torsion where pain usually affects the entire testis. Testicular torsion Twist of the spermatic cord resulting in testicular ischaemia and necrosis. Most common in males aged between 10 and 30 (peak incidence 13-15 years) Pain is usually severe and of sudden onset. Cremasteric reflex is lost and elevation of the testis does not ease the pain. Treatment is with surgical exploration. If a torted testis is identified then both testis should be fixed as the condition of bell clapper testis is often bilateral. Hydrocele Presents as a mass that transilluminates, usually possible to 'get above' it on examination. In younger men it should be investigated with USS to exclude tumour. In children it may occur as a result of a patent processus vaginalis. Treatment in adults is with a Lords or Jabouley procedure. Treatment in children is with trans inguinal ligation of PPV.

Answer 695

Recurrence following attempted resection of thyroglossal cysts is very common. Complete excision of the cyst and its track and origin is mandatory (Sistrunks procedure). Thyroglossal cysts The commonest midline neck mass in children is a congenital cyst of the thyroglossal duct. Embryologically, the cyst can arise at any point along the route of the thyroglossal duct, extending from the foramen caecum to the thyroid gland. They are typically located below the hyoid and moves both on swallowing and tongue protrusion. Whilst most cysts are asymptomatic, associated infection may result in pain and swelling. The usual treatment is excision of the cyst and track, this is a called a Sistrunk procedure.

Answer 696

Most are sporadic and risk in subsequent pregnancies is not increased. Paediatric Gastrointestinal disorders Pyloric stenosis M>F 5-10% Family history in parents Projectile non bile stained vomiting at 4-6 weeks of life Diagnosis is made by test feed or USS Treatment: Ramstedt pyloromyotomy (open or laparoscopic) Acute appendicitis Uncommon under 3 years When occurs may present atypically Mesenteric adenitis Central abdominal pain and URTI Conservative management Intussusception Telescoping bowel Proximal to or at the level of, ileocaecal valve 6-9 months age Colicky pain, diarrhoea and vomiting, sausage shaped mass, red jelly stool. Treatment: reduction with air insufflation Malrotation High caecum at the midline Feature in exomphalos, congenital diaphragmatic hernia, intrinsic duodenal atresia May be complicated by development of volvulus, infant with volvulus may have bile stained vomiting Diagnosis is made by upper GI contrast study and USS Treatment is by laparotomy, if volvulus is present (or at high risk of occurring then a ladds procedure is performed Hirschsprung's disease Absence of ganglion cells from myenteric and submucosal plexuses Occurs in 1/5000 births Full thickness rectal biopsy for diagnosis Delayed passage of meconium and abdominal distension Treatment is with rectal washouts initially, thereafter an anorectal pull through procedure Oesophageal atresia Associated with tracheo-oesophageal fistula and polyhydramnios May present with choking and cyanotic spells following aspiration VACTERL associations Meconium ileus Usually delayed passage of meconium and abdominal distension Majority have cystic fibrosis X-Rays may not show a fluid level as the meconium is viscid (depends upon feeding), PR contrast studies may dislodge meconium plugs and be therapeutic Infants who do not respond to PR contrast and NG N-acetyl cysteine will require surgery to remove the plugs Biliary atresia Jaundice > 14 days Increased conjugated bilirubin Urgent Kasai procedure Necrotising enterocolitis Prematurity is the main risk factor Early features include abdominal distension and passage of bloody stools X-Rays may show pneumatosis intestinalis and evidence of free air Increased risk when empirical antibiotics are given to infants beyond 5 days Treatment is with total gut rest and TPN, babies with perforations will require laparotomy

Answer 697

Most are sporadic and risk in subsequent pregnancies is not increased. Paediatric Gastrointestinal disorders Pyloric stenosis M>F 5-10% Family history in parents Projectile non bile stained vomiting at 4-6 weeks of life Diagnosis is made by test feed or USS Treatment: Ramstedt pyloromyotomy (open or laparoscopic) Acute appendicitis Uncommon under 3 years When occurs may present atypically Mesenteric adenitis Central abdominal pain and URTI Conservative management Intussusception Telescoping bowel Proximal to or at the level of, ileocaecal valve 6-9 months age Colicky pain, diarrhoea and vomiting, sausage shaped mass, red jelly stool. Treatment: reduction with air insufflation Malrotation High caecum at the midline Feature in exomphalos, congenital diaphragmatic hernia, intrinsic duodenal atresia May be complicated by development of volvulus, infant with volvulus may have bile stained vomiting Diagnosis is made by upper GI contrast study and USS Treatment is by laparotomy, if volvulus is present (or at high risk of occurring then a ladds procedure is performed Hirschsprung's disease Absence of ganglion cells from myenteric and submucosal plexuses Occurs in 1/5000 births Full thickness rectal biopsy for diagnosis Delayed passage of meconium and abdominal distension Treatment is with rectal washouts initially, thereafter an anorectal pull through procedure Oesophageal atresia Associated with tracheo-oesophageal fistula and polyhydramnios May present with choking and cyanotic spells following aspiration VACTERL associations Meconium ileus Usually delayed passage of meconium and abdominal distension Majority have cystic fibrosis X-Rays may not show a fluid level as the meconium is viscid (depends upon feeding), PR contrast studies may dislodge meconium plugs and be therapeutic Infants who do not respond to PR contrast and NG N-acetyl cysteine will require surgery to remove the plugs Biliary atresia Jaundice > 14 days Increased conjugated bilirubin Urgent Kasai procedure Necrotising enterocolitis Prematurity is the main risk factor Early features include abdominal distension and passage of bloody stools X-Rays may show pneumatosis intestinalis and evidence of free air Increased risk when empirical antibiotics are given to infants beyond 5 days Treatment is with total gut rest and TPN, babies with perforations will require laparotomy

Answer 698

Recurrence following attempted resection of thyroglossal cysts is very common. Complete excision of the cyst and its track and origin is mandatory (Sistrunks procedure). Thyroglossal cysts The commonest midline neck mass in children is a congenital cyst of the thyroglossal duct. Embryologically, the cyst can arise at any point along the route of the thyroglossal duct, extending from the foramen caecum to the thyroid gland. They are typically located below the hyoid and moves both on swallowing and tongue protrusion. Whilst most cysts are asymptomatic, associated infection may result in pain and swelling. The usual treatment is excision of the cyst and track, this is a called a Sistrunk procedure.

Answer 699

An abdomino-perineal excision of the colon and rectum is a cancer procedure and not appropriate in the context of inflammatory bowel disease. The only appropriate surgical option here is a proctectomy to remove the rectal stump and anal canal. IBD Ulcerative colitis Vs Crohns Crohn's disease Ulcerative colitis Distribution Mouth to anus Rectum and colon Macroscopic changes Cobblestone appearance, apthoid ulceration Contact bleeding Depth of disease Transmural inflammation Superficial inflammation Distribution pattern Patchy Continuous Histological features Granulomas (non caseating epithelioid cell aggregates with Langerhans' giant cells) Crypt abscesses, Inflammatory cells in the lamina propria Surgical treatment Ulcerative colitis In UC the main place for surgery is when medical treatment has failed, in the emergency setting this will be a sub total colectomy, end ileostomy and a mucous fistula. Electively it will be a pan proctocolectomy, an ileoanal pouch may be a selected option for some. Remember that longstanding UC increases colorectal cancer risk. Crohn's disease Unlike UC Crohn's patients need to avoid surgeons, minimal resections are the rule. They should not have ileoanal pouches as they will do poorly with them. Management of Crohn's ano rectal sepsis is with a minimal approach, simply drain sepsis and use setons to facilitate drainage. Definitive fistula surgery should be avoided.

Answer 700

Platelet dysfunction. The clopidogrel should have been stopped sooner. Vascular injuries are usually evident intraoperatively. Clopidogrel Clopidogrel is an antiplatelet agent that is usually administered orally in doses of 75mg. It is converted by the P450 enzymes in the liver into the active drug. It decreases ADP induced platelet aggregation persisting for 120 hours after the final dose. This last point is especially relevant for surgeons as it means that it needs to be stopped around 5-7 days prior to surgery. Its effects are very potent and failure to adhere to this can result in significant increases in perioperative bleeding that can be difficult to control.

Answer 701

The lateral cutaneous nerve supplies sensation to the anterior and lateral aspect of the thigh. Entrapment is commonly due to intra and extra pelvic causes. Treatment involves local anaesthetic injections. Lateral cutaneous nerve of the thigh Cutaneous nerve arising from posterior surface of the second and third lumbar ventral rami Emerges from the lateral border of psoas major anterior to the iliac crest, and passes between iliacus and iliac fascia Enters thigh posterior to the lateral end of the inguinal ligament, medial to the anterior superior iliac spine It pierces the fascia lata 10cm inferior to the anterior superior iliac spine and divides into 2 branches Anterior branch supplies skin and fascia of the anterolateral surface of the knee Smaller posterior branch supplies the skin and fascia on the lateral part of the upper leg between the greater trochanter and distal third of the thigh

Answer 702

There is a 50% risk that this lesion is malignant (in some series up to 70%). Therefore the gland should be excised entirely. At this stage a radical neck dissection is not justified. Submandibular glands- disease Physiology The submandibular glands secrete approximately 800- 1000ml saliva per day. They typically produce mixed seromucinous secretions. When parasympathetic activity is dominant; the secretions will be more serous. The parasympathetic fibres are derived from the chorda tympani nerves and the submandibular ganglion. Sensory fibres are conveyed by the lingual branch of the mandibular nerve. Sialolithiasis 80% of all salivary gland calculi occur in the submandibular gland 70% of the these calculi are radio-opaque Stones are usually composed of calcium phosphate or calcium carbonate Patients typically develop colicky pain and post prandial swelling of the gland Investigation involves sialography to demonstrate the site of obstruction and associated other stones Stones impacted in the distal aspect of Whartons duct may be removed orally, other stones and chronic inflammation will usually require gland excision Sialadenitis Usually occurs as a result of Staphylococcus aureus infection Pus may be seen leaking from the duct, erythema may also be noted Development of a sub mandibular abscess is a serious complication as it may spread through the other deep fascial spaces and occlude the airway Submandibular tumours Only 8% of salivary gland tumours affect the sub mandibular gland Of these 50% are malignant (usually adenoid cystic carcinoma) Diagnosis usually involves fine needle aspiration cytology Imaging is with CT and MRI In view of the high prevalence of malignancy, all masses of the submandibular glands should generally be excised.

Answer 703

This patient is at extremely low risk of having sustained a scaphoid injury and may be discharged. Scaphoid fractures - Incidence of scaphoid fractures in UK ranges from 12.4 per 100,000 to 29 per 100,000 Surface of scaphoid is covered by articular cartilage with small area available for blood vessels (fracture risks blood supply) Forms floor of anatomical snuffbox Risk of fracture associated with fall onto outstretched hand (tubercle, waist, or proximal third) A series of 4 scaphoid radiographs should be undertaken (PA, pronated oblique, Ziter view and lateral view). The Ziter view is a PA view with the wrist in ulnar deviation and beam angulated at 20 degrees Sensitivity of scaphoid radiographs in 1st week of injury is 80% Immobilization of scaphoid fractures difficult Repeat imaging should be done at 10 days. MRI should be done in cases of diagnostic uncertainty Classification of scaphoid fractures Scaphoid tubercle Distal pole Waist Proximal pole Management Undisplaced fractures of the waist of the scaphoid and most distal pole fractures can be managed in a cast for 6 weeks with high rates of union. Displaced scaphoid waist fractures (more than 1-2mm) should be viewed as unstable and surgically fixed. All proximal pole fractures should be fixed surgically. Complications Non union of scaphoid Avascular necrosis of the scaphoid Scapholunate disruption and wrist collapse Degenerative changes of the adjacent joint Reference Berber O et al. Fractures of the scaphoid. BMJ 2020 (369): 414-416.

Answer 704

Adrenal cortical adenoma 25% of all adrenal lesions >4cm in diameter are malignant Incidentalomas of the adrenal gland are common and represent the most likely lesion in this scenario. Clearly the other lesions are all possibilities but are unlikely. Adrenal lesions- Incidental Incidentaloma of the adrenal glands have become increasingly common as CT scanning of the abdomen is widely undertaken. Prevalences range from 1.5-9% in autopsy studies. Overall, 75% will be non functioning adenomas. Investigation to exclude a functioning lesion is as below: Investigation Morning and midnight plasma cortisol measurements Dexamethasone suppression test 24 hour urinary cortisol excretion 24 hour urinary excretion of catecholamines Serum potassium, aldosterone and renin levels Management The risk of malignancy is related to the size of the lesion and 25% of all masses greater than 4cm will be malignant. Such lesions should usually be excised. Where a lesion is a suspected metastatic deposit a biopsy may be considered.

Answer 705

The cervical oesophagus is supplied by the inferior thyroid artery. The thoracic oesophagus (removed in this case) is supplied by direct branches from the thoracic aorta. Oesophagus - 25cm long Starts at C6 vertebra, pierces diaphragm at T10 and ends at T11 Squamous epithelium Constrictions of the oesophagus Structure Distance from incisors Cricoid cartilage 15cm Arch of the Aorta 22.5cm Left principal bronchus 27cm Diaphragmatic hiatus 40cm Relations Anteriorly Trachea to T4 Recurrent laryngeal nerve Left bronchus, Left atrium Diaphragm Posteriorly Thoracic duct to left at T5 Hemiazygos to the left T8 Descending aorta First 2 intercostal branches of aorta Left Thoracic duct Left subclavian artery Right Azygos vein Arterial, venous and lymphatic drainage of the oesophagus Artery Vein Lymphatics Muscularis externa Upper third Inferior thyroid Inferior thyroid Deep cervical Striated muscle Mid third Aortic branches Azygos branches Mediastinal Smooth & striated muscle Lower third Left gastric Left gastric Gastric Smooth muscle Nerve supply Upper half is supplied by recurrent laryngeal nerve Lower half by oesophageal plexus (vagus) Histology Mucosa :Non-keratinized stratified squamous epithelium Submucosa: glandular tissue Muscularis externa (muscularis): composition varies. See table Adventitia

Answer 706

Mesenteric vein thrombosis may complicate severe intra abdominal sepsis and when it progresses may impair bowel perfusion. The serosa is quite resistant to ischaemia so in this case the appearances are usually patchy. Mesenteric vessel disease Mesenteric ischaemia accounts for 1 in 1000 acute surgical admissions. It is primarily caused by arterial embolism resulting in infarction of the colon. It is more likely to occur in areas such as the splenic flexure that are located at the borders of the territory supplied by the superior and inferior mesenteric arteries. Types Acute mesenteric embolus (commonest 50%) Sudden onset abdominal pain followed by profuse diarrhoea. May be associated with vomiting. Rapid clinical deterioration. Serological tests: WCC, lactate, amylase may all be abnormal particularly in established disease. These can be normal in the early phases. Acute on chronic mesenteric ischaemia Usually longer prodromal history. Post prandial abdominal discomfort and weight loss are dominant features. Patients will usually present with an acute on chronic event, but otherwise will tend not to present until mesenteric flow is reduced by greater than 80%. When acute thrombosis occurs presentation may be as above. In the chronic setting the symptoms will often be those of ischaemic colitis (mucosa is the most sensitive area to this insult). Mesenteric vein thrombosis Usually a history over weeks. Overt abdominal signs and symptoms will not occur until venous thrombosis has reached a stage to compromise arterial inflow. Thrombophilia accounts for 60% of cases. Low flow mesenteric infarction This occurs in patients with multiple co morbidities in whom mesenteric perfusion is significantly compromised by overuse of inotropes or background cardiovascular compromise. The end result is that the bowel is not adequately perfused and infarcts occur from the mucosa outwards. Diagnosis Serological tests: WCC, lactate, CRP, amylase (can be normal in early disease). Cornerstone for diagnosis of arterial AND venous mesenteric disease is CT angiography scanning in the arterial phase with thin slices (<5mm). Venous phase contrast is not helpful. SMA duplex USS is useful in the evaluation of proximal SMA disease in patients with chronic mesenteric ischaemia. MRI is of limited use due to gut peristalsis and movement artefact. Management Overt signs of peritonism: Laparotomy Mesenteric vein thrombosis: If no peritonism: Medical management with IV heparin At operation limited resection of frankly necrotic bowel with view to relook laparotomy at 24-48h. In the interim urgent bowel revascularisation via endovascular (preferred) or surgery. Prognosis Overall poor. Best outlook is from an acute ischaemia from an embolic event where surgery occurs within 12h. Survival may be 50%. This falls to 30% with treatment delay. The other conditions carry worse survival figures.

Answer 707

The quadrangular space is bordered by the humerus laterally, subscapularis and teres minor superiorly, teres major inferiorly and the long head of triceps medially. It lies lateral to the triangular space. It transmits the axillary nerve and posterior circumflex humeral artery. Shoulder joint Shallow synovial ball and socket type of joint. It is an inherently unstable joint, but is capable to a wide range of movement. Stability is provided by muscles of the rotator cuff that pass from the scapula to insert in the greater tuberosity (all except sub scapularis-lesser tuberosity). Glenoid labrum Fibrocartilaginous rim attached to the free edge of the glenoid cavity Tendon of the long head of biceps arises from within the joint from the supraglenoid tubercle, and is fused at this point to the labrum. The long head of triceps attaches to the infraglenoid tubercle Fibrous capsule Attaches to the scapula external to the glenoid labrum and to the labrum itself (postero-superiorly) Attaches to the humerus at the level of the anatomical neck superiorly and the surgical neck inferiorly Anteriorly the capsule is in contact with the tendon of subscapularis, superiorly with the supraspinatus tendon, and posteriorly with the tendons of infraspinatus and teres minor. All these blend with the capsule towards their insertion. Two defects in the fibrous capsule; superiorly for the tendon of biceps. Anteriorly there is a defect beneath the subscapularis tendon. The inferior extension of the capsule is closely related to the axillary nerve at the surgical neck and this nerve is at risk in anteroinferior dislocations. It also means that proximally sited osteomyelitis may progress to septic arthritis. Movements and muscles Flexion Anterior part of deltoid Pectoralis major Biceps Coracobrachialis Extension Posterior deltoid Teres major Latissimus dorsi Adduction Pectoralis major Latissimus dorsi Teres major Coracobrachialis Abduction Mid deltoid Supraspinatus Medial rotation Subscapularis Anterior deltoid Teres major Latissimus dorsi Lateral rotation Posterior deltoid Infraspinatus Teres minor Important anatomical relations Anteriorly Brachial plexus Axillary artery and vein Posterior Suprascapular nerve Suprascapular vessels Inferior Axillary nerve Circumflex humeral vessels

Answer 708

This patient has tuberous sclerosis. This is associated with angiomyolipoma, which is present in 60-80% patients. It is a benign lesion. Renal lesions Lesion Disease specific features Treatment Renal cell carcinoma Most present with haematuria (50%) Common renal tumour (85% cases) Paraneoplastic features include hypertension and polycythaemia Most commonly has haematogenous mestastasis Usually radical or partial nephrectomy Nephroblastoma Rare childhood tumour It accounts for 80% of all genitourinary malignancies in those under the age of 15 years Up to 90% will have a mass 50% will be hypertensive Diagnostic work up includes ultrasound and CT scanning Surgical resection combined with chemotherapy (usually vincristine, actinomycin D and doxorubicin) Neuroblastoma Most common extracranial tumour of childhood 80% occur in those under 4 years of age Tumour of neural crest origin (up to 50% occur in the adrenal gland) The tumour is usually calcified and may be diagnosed using MIBG scanning Staging is with CT Surgical resection, radiotherapy and chemotherapy Transitional cell carcinoma Accounts for 90% of lower urinary tract tumours, but only 10% of renal tumours Males affected 3x more than females Occupational exposure to industrial dyes and rubber chemicals may increase risk Up to 80% present with painless haematuria Diagnosis and staging is with CT IVU Radical nephroureterectomy Angiomyolipoma 80% of these hamartoma type lesions occur sporadically, the remainder are seen in those with tuberous sclerosis Tumour is composed of blood vessels, smooth muscle and fat Massive bleeding may occur in 10% of cases 50% of patients with lesions >4cm will have symptoms and will require surgical resection

Answer 709

Impacted fractures of the surgical neck are stable injuries and usually heal without complication. It is rare to need to resort to surgery. Its important to start physiotherapy early. Proximal humerus fractures Very common injury. Usually through the surgical neck. Number of classification systems though for practical purposes describing the number of fracture fragments is probably easier. Some key points: It is rare to have fractures through the anatomical neck. Anatomical neck fractures which are displaced by >1cm carry a risk of avascular necrosis to the humeral head. In children the commonest injury pattern is a greenstick fracture through the surgical neck. Impacted fractures of the surgical neck are usually managed with a collar and cuff for 3 weeks followed by physiotherapy. More significant displaced fractures may require open reduction and fixation or use of an intramedullary device.

Answer 710

This man is peri arrest with the diagnosis of pulmonary embolism (chest pain,bedbound, collapse, low saturations). He needs urgent thrombolysis with alteplase (he may not survive if you wait for the medical Spr/ITU to arrive!). Pulmonary embolism: management A summary of the British Thoracic Society guidelines Heparin should be given if intermediate or high clinical probability before imaging. Unfractionated heparin (UFH) should be considered (a) as a first dose bolus, (b) in massive PE, or (c) where rapid reversal of effect may be needed. Otherwise, low molecular weight heparin (LMWH) should be considered as preferable to UFH, having equal efficacy and safety and being easier to use. Oral anticoagulation should only be commenced once VTE has been reliably confirmed. The target INR should be 2.0-3.0; when this is achieved, heparin can be discontinued. The standard duration of oral anticoagulation is: 4 to 6 weeks for temporary risk factors, 3 months for first idiopathic, and at least 6 months for other; the risk of bleeding should be balanced with that of further VTE. Massive PE CTPA or echocardiography will reliably diagnose clinically massive PE. Thrombolysis is 1st line for massive PE (ie circulatory failure) and may be instituted on clinical grounds alone if cardiac arrest is imminent; a 50 mg bolus of alteplase is recommended. Invasive approaches (thrombus fragmentation and IVC filter insertion) should be considered where facilities and expertise are readily available.

Answer 711

The serum amylase may rise and fall quite quickly and lead to a false negative result. Should the clinical picture not be concordant with the amylase level then serum lipase or a CT Scan should be performed. Management of Pancreatitis Management of Acute Pancreatitis in the UK Diagnosis Traditionally hyperamylasaemia has been utilised with amylase being elevated three times the normal range. However, amylase may give both false positive and negative results. Serum lipase is both more sensitive and specific than serum amylase. It also has a longer half life. Serum amylase levels do not correlate with disease severity. Differential causes of hyperamylasaemia Acute pancreatitis Pancreatic pseudocyst Mesenteric infarct Perforated viscus Acute cholecystitis Diabetic ketoacidosis Assessment of severity Glasgow, Ranson scoring systems and APACHE II Biochemical scoring e.g. using CRP Features that may predict a severe attack within 48 hours of admission to hospital Initial assessment Clinical impression of severity Body mass index >30 Pleural effusion APACHE score >8 24 hours after admission Clinical impression of severity APACHE II >8 Glasgow score of 3 or more Persisting multiple organ failure CRP>150 48 hours after admission Glasgow Score of >3 CRP >150 Persisting or progressive organ failure Table adapted from UK guidelines for management of acute pancreatitis. GUT 2005, 54 suppl III Management Nutrition There is reasonable evidence to suggest that the use of enteral nutrition does not worsen the outcome in pancreatitis Most trials to date were underpowered to demonstrate a conclusive benefit. The rationale behind feeding is that it helps to prevent bacterial translocation from the gut, thereby contributing to the development of infected pancreatic necrosis. Use of antibiotic therapy Many UK surgeons administer antibiotics to patients with acute pancreatitis. However, there is very little evidence to support this practice. A recent Cochrane review highlights the potential benefits of administering Imipenem to patients with established pancreatic necrosis in the hope of averting the progression to infection. There are concerns that the administration of antibiotics in mild attacks of pancreatitis will not affect outcome and may contribute to antibiotic resistance and increase the risks of antibiotic associated diarrhoea. Surgery Patients with acute pancreatitis due to gallstones should undergo early cholecystectomy. Patients with obstructed biliary system due to stones should undergo early ERCP. Patients with extensive necrosis where infection is suspected should usually undergo FNA for culture. Patients with infected necrosis should undergo either radiological drainage or surgical necrosectomy. The choice of procedure depends upon local expertise. References www.bsg.org.uk/pdfworddocs/pancreatic.pdf Antibiotic therapy for prophylaxis against infection of pancreatic necrosis in acute pancreatitis. Villatoro et al. Cochrane Library DOI: 10.1002/14651858.CD002941.pub3. 2010 version.

Answer 712

Kocher's 'WIFE' is: WCC >12 Inability to weight bear Fever ESR >40 = >90 chance of septic arthritis Kocher criteria 1. Non weight bearing on affected side 2. ESR > 40 mm/hr 3. Fever 4. WBC count of >12,000 mm3 - When 4/4 criteria are met, there is a 99% chance that the child has septic arthritis The Kocher criteria do not consider blood culture results. Septic arthritis- Paediatric Septic arthritis Staph aureus commonest organism Urgent washout and antibiotics otherwise high risk of joint destruction Diagnosis Plain x-rays Consider aspiration Utilise the Kocher criteria (see below) Kocher criteria: 1. Non weight bearing on affected side 2. ESR > 40 mm/hr 3. Fever 4. WBC count of >12,000 mm3 - when 4/4 criteria are met, there is a 99% chance that the child has septic arthritis Treatment Surgical drainage of the affected joint is required, this should be done as soon as possible since permanent damage to the joint may occur. In some cases repeated procedures are necessary. Appropriate intravenous antibiotics should be administered.

Answer 713

Unlike low molecular weight heparins that do not require monitoring unfractionated heparin does require monitoring, this is done by measuring the APTT. Heparin Causes the formation of complexes between antithrombin and activated thrombin/factors 7,9,10,11 & 12 Advantages of low molecular weight heparin Better bioavailability Lower risk of bleeding Longer half life Little effect on APTT at prophylactic dosages Less risk of HIT Complications Bleeding Osteoporosis Heparin induced thrombocytopenia (HIT): occurs 5-14 days after 1st exposure Anaphylaxis In surgical patients that may need a rapid return to theatre, administration of unfractionated heparin is preferred; as low molecular weight heparins have a longer duration of action and are harder to reverse.

Answer 714

Adrenal cortex mnemonic: GFR - ACD DHEA possesses some androgenic activity and is almost exclusively released from the adrenal gland. Renin-angiotensin-aldosterone system Adrenal cortex (mnemonic GFR - ACD) Zona glomerulosa (on outside): mineralocorticoids, mainly aldosterone Zona fasciculata (middle): glucocorticoids, mainly cortisol Zona reticularis (on inside): androgens, mainly dehydroepiandrosterone (DHEA) Renin Released by JGA cells in kidney in response to reduced renal perfusion, low sodium Hydrolyses angiotensinogen to form angiotensin I Factors stimulating renin secretion Low BP Hyponatraemia Sympathetic nerve stimulation Catecholamines Erect posture Angiotensin ACE in lung converts angiotensin I → angiotensin II Vasoconstriction leads to raised BP Stimulates thirst Stimulates aldosterone and ADH release Aldosterone Released by the zona glomerulosa in response to raised angiotensin II, potassium, and ACTH levels Causes retention of Na+ in exchange for K+/H+ in distal tubule

Answer 715

When DNA cannot be repaired it will induce cellular apoptosis (not necrosis) Genetics and surgical disease Some of the more commonly occurring genetic conditions occurring in surgical patients are presented here. Li-Fraumeni Syndrome Autosomal dominant Consists of germline mutations to p53 tumour suppressor gene High incidence of malignancies particularly sarcomas and leukaemias Diagnosed when: *Individual develops sarcoma under 45 years *First degree relative diagnosed with any cancer below age 45 years and another family member develops malignancy under 45 years or sarcoma at any age BRCA 1 and 2 Carried on chromosome 17 (BRCA 1) and Chromosome 13 (BRCA 2) Linked to developing breast cancer (60%) risk. Associated risk of developing ovarian cancer (55% with BRCA 1 and 25% with BRCA 2). Lynch Syndrome Autosomal dominant Develop colonic cancer and endometrial cancer at young age 80% of affected individuals will get colonic and/ or endometrial cancer High risk individuals may be identified using the Amsterdam criteria Amsterdam criteria Three or more family members with a confirmed diagnosis of colorectal cancer, one of whom is a first degree (parent, child, sibling) relative of the other two. Two successive affected generations. One or more colon cancers diagnosed under age 50 years. Familial adenomatous polyposis (FAP) has been excluded. Gardners syndrome Autosomal dominant familial colorectal polyposis Multiple colonic polyps Extra colonic diseases include: skull osteoma, thyroid cancer and epidermoid cysts Desmoid tumours are seen in 15% Mutation of APC gene located on chromosome 5 Due to colonic polyps most patients will undergo colectomy to reduce risk of colorectal cancer Now considered a variant of familial adenomatous polyposis coli

Answer 716

The superficial branch of the radial nerve passes superior to the extensor retinaculum in the position of this laceration and is at greatest risk of injury. The dorsal branch of the ulnar nerve and artery also pass superior to the extensor retinaculum but are located medially. Extensor retinaculum The extensor retinaculum is a thickening of the deep fascia that stretches across the back of the wrist and holds the long extensor tendons in position. Its attachments are: The pisiform and triquetral medially The end of the radius laterally Structures related to the extensor retinaculum Structures superficial to the retinaculum Basilic vein Dorsal cutaneous branch of the ulnar nerve Cephalic vein Superficial branch of the radial nerve Structures passing deep to the extensor retinaculum Extensor carpi ulnaris tendon Extensor digiti minimi tendon Extensor digitorum and extensor indicis tendon Extensor pollicis longus tendon Extensor carpi radialis longus tendon Extensor carpi radialis brevis tendon Abductor pollicis longus and extensor pollicis brevis tendons Beneath the extensor retinaculum fibrous septa form six compartments that contain the extensor muscle tendons. Each compartment has its own synovial sheath. The radial artery The radial artery passes between the lateral collateral ligament of the wrist joint and the tendons of the abductor pollicis longus and extensor pollicis brevis. Image illustrating the topography of tendons passing under the extensor retinaculum

Answer 717

To treat hyperhidrosis the sympathetic ganglia at T2 and T3 should be divided. Dividing the other structures listed would either carry a risk of Horners syndrome or be ineffective. Useful mnemonic: T2 & T3 Make the hands sweat-free Sympathetic nervous system- anatomy The cell bodies of the pre-ganglionic efferent neurones lie in the lateral horn of the grey matter of the spinal cord in the thoraco-lumbar regions. The pre-ganglionic efferents leave the spinal cord at levels T1-L2. These pass to the sympathetic chain. Lateral branches of the sympathetic chain connect it to every spinal nerve. These post ganglionic nerves will pass to structures that receive sympathetic innervation at the periphery. Sympathetic chains These lie on the vertebral column and run from the base of the skull to the coccyx. Cervical region Lie anterior to the transverse processes of the cervical vertebrae and posterior to the carotid sheath. Thoracic region Lie anterior to the neck of the upper ribs and and lateral sides of the lower thoracic vertebrae.They are covered by the parietal pleura Lumbar region Enter by passing posterior to the medial arcuate ligament. Lie anteriorly to the vertebrae and medial to psoas major. Sympathetic ganglia Superior cervical ganglion lies anterior to C2 and C3. Middle cervical ganglion (if present) C6 Stellate ganglion- anterior to transverse process of C7, lies posterior to the subclavian artery, vertebral artery and cervical pleura. Thoracic ganglia are segmentally arranged. There are usually 4 lumbar ganglia. Clinical importance Interruption of the head and neck supply of the sympathetic nerves will result in an ipsilateral Horners syndrome. For treatment of hyperhidrosis the sympathetic denervation can be achieved by removing the second and third thoracic ganglia with their rami. Removal of T1 will cause a Horners syndrome and is therefore not performed. In patients with vascular disease of the lower limbs a lumbar sympathetomy may be performed, either radiologically or (more rarely now) surgically. The ganglia of L2 and below are disrupted. If L1 is removed then ejaculation may be compromised (and little additional benefit conferred as the preganglionic fibres do not arise below L2.

Answer 718

Mnemonic for rotator cuff muscles (TISS) Teres minor Infraspinatus Supraspinatus Subscapularis Deltoid may abduct the s houlder and is not a rotator cuff muscle. Muscles of the rotator cuff Muscle Innervation Supraspinatus muscle Suprascapular nerve Infraspinatus muscle Suprascapular nerve Teres minor muscle Axillary nerve Subscapularis muscle Superior and inferior subscapular nerves

Answer 719

As a rule most vascular surgeons will administer approximately 3,000 units of systemic heparin 3-5 minutes prior to cross clamping to help prevent further intra arterial thromboses. A dose of 30,000 units is given prior to going on cardiopulmonary bypass. Heparin given at induction will cause bleeding during routine dissection. Heparin Causes the formation of complexes between antithrombin and activated thrombin/factors 7,9,10,11 & 12 Advantages of low molecular weight heparin Better bioavailability Lower risk of bleeding Longer half life Little effect on APTT at prophylactic dosages Less risk of HIT Complications Bleeding Osteoporosis Heparin induced thrombocytopenia (HIT): occurs 5-14 days after 1st exposure Anaphylaxis In surgical patients that may need a rapid return to theatre, administration of unfractionated heparin is preferred; as low molecular weight heparins have a longer duration of action and are harder to reverse.

Answer 720

The vessel will be the gastroduodenal artery, this arises from the common hepatic artery. Gastroduodenal artery Supplies Pylorus, proximal part of the duodenum, and indirectly to the pancreatic head (via the anterior and posterior superior pancreaticoduodenal arteries) Path The gastroduodenal artery most commonly arises from the common hepatic artery of the coeliac trunk. It terminates by bifurcating into the right gastroepiploic artery and the superior pancreaticoduodenal artery

Answer 721

Branchial cysts are remnants of the branchial cleft. They may become infected. Neck lumps The table below gives characteristic exam question features for conditions causing neck lumps: Reactive lymphadenopathy By far the most common cause of neck swellings. There may be a history of local infection or a generalised viral illness Lymphoma Rubbery, painless lymphadenopathy The phenomenon of pain whilst drinking alcohol is very uncommon There may be associated night sweats and splenomegaly Thyroid swelling May be hypo-, eu- or hyperthyroid symptomatically Moves upwards on swallowing Thyroglossal cyst More common in patients < 20 years old Usually midline, between the isthmus of the thyroid and the hyoid bone Moves upwards with protrusion of the tongue May be painful if infected Pharyngeal pouch More common in older men Represents a posteromedial herniation between thyropharyngeus and cricopharyngeus muscles Usually not seen, but if large then a midline lump in the neck that gurgles on palpation Typical symptoms are dysphagia, regurgitation, aspiration and chronic cough Cystic hygroma A congenital lymphatic lesion (lymphangioma) typically found in the neck, classically on the left side Most are evident at birth, around 90% present before 2 years of age Branchial cyst An oval, mobile cystic mass that develops between the sternocleidomastoid muscle and the pharynx Develop due to failure of obliteration of the second branchial cleft in embryonic development Usually present in early adulthood Cervical rib More common in adult females Around 10% develop thoracic outlet syndrome Carotid aneurysm Pulsatile lateral neck mass which doesn't move on swallowing

Answer 722

Don't confuse loop ileostomy and loop colostomy. A loop colostomy is the only safe option for an obstructing rectal cancer. Loop ileostomy in the context of rectal cancer is performed to mitigate the effects of anastomotic leak following a low anterior resection. Large bowel obstruction resulting from carcinoma should be resected, stented or defunctioned. The first two options typically apply to tumours above the peritoneal reflection. Lower tumours should be defunctioned with a loop colostomy and then formal staging undertaken prior to definitive surgery. An emergency attempted rectal resection carries a high risk of involvement of the circumferential resection margin and is not recommended. Abdominal stomas Stomas may be sited during a range of abdominal procedures and involve bringing the lumen or visceral contents onto the skin. In most cases this applies to the bowel. However, other organs or their contents may be diverted in case of need. With bowel stomas the type method of construction and to a lesser extent the site will be determined by the contents of the bowel. In practice, small bowel stomas should be spouted so that their irritant contents are not in contact with the skin. Colonic stomas do not need to be spouted as their contents are less irritant. In the ideal situation the site of the stoma should be marked with the patient prior to surgery. Stoma siting is important as it will ultimately influence the ability of the patient to manage their stoma and also reduce the risk of leakage. Leakage of stoma contents and subsequent maceration of the surrounding skin can rapidly progress into a spiraling loss of control of stoma contents. Types of stomas Name of stoma Use Common sites Gastrostomy Gastric decompression or fixation Feeding Epigastrium Loop jejunostomy Seldom used as very high output May be used following emergency laparotomy with planned early closure Any location according to need Percutaneous jejunostomy Usually performed for feeding purposes and site in the proximal bowel Usually left upper quadrant Loop ileostomy Defunctioning of colon e.g. following rectal cancer surgery Does not decompress colon (if ileocaecal valve competent) Usually right iliac fossa End ileostomy Usually following complete excision of colon or where ileo-colic anastomosis is not planned May be used to defunction colon, but reversal is more difficult Usually right iliac fossa End colostomy Where a colon is diverted or resected and anastomosis is not primarily achievable or desirable Either left or right iliac fossa Loop colostomy To defunction a distal segment of colon Since both lumens are present the distal lumen acts as a vent May be located in any region of the abdomen, depending upon colonic segment used Caecostomy Stoma of last resort where loop colostomy is not possible Right iliac fossa Mucous fistula To decompress a distal segment of bowel following colonic division or resection Where closure of a distal resection margin is not safe or achievable

Answer 723

This is a Smith fracture (reverse Colles' fracture); unlike a Colles' this is a high velocity injury and may require surgical correction. Note that Colles' fractures are usually dorsally displaced. Eponymous fractures Colles' fracture (dinner fork deformity) Fall onto extended outstretched hand Classical Colles' fractures have the following 3 features: 1. Transverse fracture of the radius 2. 1 inch proximal to the radio-carpal joint 3. Dorsal displacement and angulation Smith's fracture (reverse Colles' fracture) Volar angulation of distal radius fragment (Garden spade deformity) Caused by falling backwards onto the palm of an outstretched hand or falling with wrists flexed Bennett's fracture Intra-articular fracture of the first carpometacarpal joint Impact on flexed metacarpal, caused by fist fights X-ray: triangular fragment at ulnar base of metacarpal Monteggia's fracture Dislocation of the proximal radioulnar joint in association with an ulna fracture Fall on outstretched hand with forced pronation Needs prompt diagnosis to avoid disability Galeazzi fracture Radial shaft fracture with associated dislocation of the distal radioulnar joint Direct blow Pott's fracture Bimalleolar ankle fracture Forced foot eversion Barton's fracture Distal radius fracture (Colles'/Smith's) with associated radiocarpal dislocation Fall onto extended and pronated wrist Involvement of the joint is a defining feature Holstein Lewis Fracture A HolsteinLewis fracture is a fracture of the distal third of the humerus resulting in entrapment of the radial nerve. The radial nerve is one of the major nerves of the upper limb. It innervates all of the muscles in the extensor compartments of the arm. Conservative treatment includes reduction and use of a functional brace Vascular injury may require open surgery

Answer 724

Slow transmission of mechanothermal stimuli is transmitted via C fibres. A γ fibres transmit information relating to motor proprioception, A β fibres transmit touch and pressure and B fibres are autonomic fibres. Pain - neuronal transmission Somatic pain Peripheral nociceptors are innervated by either small myelinated fibres (A-delta) fibres or by unmyelinated C fibres. The A gamma fibres register high intensity mechanical stimuli. The C fibres usually register high intensity mechanothermal stimuli.

Answer 725

Young athletic females are the group most frequently affected by spondylolythesis who have a background of spondylolysis. Whilst the latter condition is a risk factor for spondylolythesis the former condition is most likely in a young athletic female who presents with sudden pain. Diseases affecting the vertebral column Ankylosing spondylitis Chronic inflammatory disorder affecting the axial skeleton Sacro-ilitis is a usually visible in plain films Up to 20% of those who are HLA B27 positive will develop the condition Affected articulations develop bony or fibrous changes Typical spinal features include loss of the lumbar lordosis and progressive kyphosis of the cervico-thoracic spine Scheuermann's disease Epiphysitis of the vertebral joints is the main pathological process Predominantly affects adolescents Symptoms include back pain and stiffness X-ray changes include epiphyseal plate disturbance and anterior wedging Clinical features include progressive kyphosis (at least 3 vertebrae must be involved) Minor cases may be managed with physiotherapy and analgesia, more severe cases may require bracing or surgical stabilisation Scoliosis Consists of curvature of the spine in the coronal plane Divisible into structural and non structural, the latter being commonest in adolescent females who develop minor postural changes only. Postural scoliosis will typically disappear on manoeuvres such as bending forwards Structural scoliosis affects > 1 vertebral body and is divisible into idiopathic, congential and neuromuscular in origin. It is not correctable by alterations in posture Within structural scoliosis, idiopathic is the most common type Severe, or progressive structural disease is often managed surgically with bilateral rod stabilisation of the spine Spina bifida Non fusion of the vertebral arches during embryonic development Three categories; myelomeningocele, spina bifida occulta and meningocele Myelomeningocele is the most severe type with associated neurological defects that may persist in spite of anatomical closure of the defect Up to 10% of the population may have spina bifida occulta, in this condition the skin and tissues (but not not bones) may develop over the distal cord. The site may be identifiable by a birth mark or hair patch The incidence of the condition is reduced by use of folic acid supplements during pregnancy Spondylolysis Congenital or acquired deficiency of the pars interarticularis of the neural arch of a particular vertebral body, usually affects L4/ L5 May be asymptomatic and affects up to 5% of the population Spondylolysis is the commonest cause of spondylolisthesis in children Asymptomatic cases do not require treatment Spondylolisthesis This occurs when one vertebra is displaced relative to its immediate inferior vertebral body May occur as a result of stress fracture or spondylolysis Traumatic cases may show the classic 'Scotty Dog' appearance on plain films Treatment depends upon the extent of deformity and associated neurological symptoms, minor cases may be actively monitored. Individuals with radicular symptoms or signs will usually require spinal decompression and stabilisation

Answer 726

The sympathetic chain lies posterior to the parietal pleura. During a thorascopic sympathectomy this structure will need to be divided. The intercostal vessels lie posteriorly. They may be damaged with troublesome bleeding but otherwise are best left alone as deliberate division will not improve surgical access. Sympathetic nervous system- anatomy The cell bodies of the pre-ganglionic efferent neurones lie in the lateral horn of the grey matter of the spinal cord in the thoraco-lumbar regions. The pre-ganglionic efferents leave the spinal cord at levels T1-L2. These pass to the sympathetic chain. Lateral branches of the sympathetic chain connect it to every spinal nerve. These post ganglionic nerves will pass to structures that receive sympathetic innervation at the periphery. Sympathetic chains These lie on the vertebral column and run from the base of the skull to the coccyx. Cervical region Lie anterior to the transverse processes of the cervical vertebrae and posterior to the carotid sheath. Thoracic region Lie anterior to the neck of the upper ribs and and lateral sides of the lower thoracic vertebrae.They are covered by the parietal pleura Lumbar region Enter by passing posterior to the medial arcuate ligament. Lie anteriorly to the vertebrae and medial to psoas major. Sympathetic ganglia Superior cervical ganglion lies anterior to C2 and C3. Middle cervical ganglion (if present) C6 Stellate ganglion- anterior to transverse process of C7, lies posterior to the subclavian artery, vertebral artery and cervical pleura. Thoracic ganglia are segmentally arranged. There are usually 4 lumbar ganglia. Clinical importance Interruption of the head and neck supply of the sympathetic nerves will result in an ipsilateral Horners syndrome. For treatment of hyperhidrosis the sympathetic denervation can be achieved by removing the second and third thoracic ganglia with their rami. Removal of T1 will cause a Horners syndrome and is therefore not performed. In patients with vascular disease of the lower limbs a lumbar sympathetomy may be performed, either radiologically or (more rarely now) surgically. The ganglia of L2 and below are disrupted. If L1 is removed then ejaculation may be compromised (and little additional benefit conferred as the preganglionic fibres do not arise below L2.

Answer 727

Recurrent laryngeal nerve Branch of the vagus nerve Path Right Arises anterior to the subclavian artery and ascends obliquely next to the trachea, behind the common carotid artery It is either anterior or posterior to the inferior thyroid artery Left Arises left to the arch of the aorta Winds below the aorta Ascends along the side of the trachea Then both Pass in a groove between the trachea and oesophagus Enters the larynx behind the articulation between the thyroid cartilage and cricoid Distributed to larynx muscles Branches to Cardiac plexus Mucous membrane and muscular coat of the oesophagus and trachea Innervates Intrinsic larynx muscles (excluding cricothyroid)

Answer 728

The internal sphincter is formed by the circular arrangement of smooth muscle of the bladder wall at the neck of the bladder. The detrusor muscle and internal sphincter are under autonomic control. Parasympathetic fibres cause contraction of the detrusor muscle and relaxation of the internal sphincter. Sympathetic fibres cause relaxation of the detrusor muscle and contraction of the internal sphincter. The external sphincter is under voluntary control. Bladder The empty bladder is contained within the pelvic cavity. It is usually a three sided pyramid. The apex of the bladder points forwards towards the symphysis pubis and the base lies immediately anterior to the rectum or vagina. Continuous with the apex is the median umbilical ligament, during development this was the site of the urachus. The inferior aspect of the bladder is retroperitoneal and the superior aspect covered by peritoneum. As the bladder distends it will tend to separate the peritoneum from the fascia of transversalis. For this reason a bladder that is distended due to acute urinary retention may be approached with a suprapubic catheter that avoids entry into the peritoneal cavity. The trigone is the least mobile part of the bladder and forms the site of the ureteric orifices and internal urethral orifice. In the empty bladder the ureteric orifices are approximately 2-3cm apart, this distance may increase to 5cm in the distended bladder. Arterial supply The superior and inferior vesical arteries provide the main blood supply to the bladder. These are branches of the internal iliac artery. Venous drainage In males the bladder is drained by the vesicoprostatic venous plexus. In females the bladder is drained by the vesicouterine venous plexus. In both sexes this venous plexus will ultimately drain to the internal iliac veins. Lymphatic drainage Lymphatic drainage is predominantly to the external iliac nodes, internal iliac and obturator nodes also form sites of bladder lymphatic drainage. Innervation Parasympathetic nerve fibres innervate the bladder from the pelvic splanchnic nerves. Sympathetic nerve fibres are derived from L1 and L2 via the hypogastric nerve plexuses. The parasympathetic nerve fibres will typically cause detrusor muscle contraction and result in voiding. The muscle of the trigone is innervated by the sympathetic nervous system. The external urethral sphincter is under conscious control. During bladder filling the rate of firing of nerve impulses to the detrusor muscle is low and receptive relaxation occurs. At higher volumes and increased intra vesical pressures the rate of neuronal firing will increase and eventually voiding will occur.

Answer 729

The Bainbridge reflex is the increase in heart rate mediated via atrial stretch receptors that occurs following a rapid infusion of blood. Note the question asks which will not occur and that is why it is A and not the other options. Cardiac physiology - The heart has four chambers ejecting blood into both low pressure and high pressure systems. The pumps generate pressures of between 0-25mmHg on the right side and 0-120 mmHg on the left. At rest diastole comprises 2/3 of the cardiac cycle. The product of the frequency of heart rate and stroke volume combine to give the cardiac output which is typically 5-6L per minute. Detailed descriptions of the various waveforms are often not a feature of MRCS A (although they are on the syllabus). However, they are a very popular topic for surgical physiology in the MRCS B exam. Electrical properties Intrinsic myogenic rhythm within cardiac myocytes means that even the denervated heart is capable of contraction. In the normal situation the cardiac impulse is generated in the sino atrial node in the right atrium and conveyed to the ventricles via the atrioventricular node. The sino atrial node is also capable of spontaneous discharge and in the absence of background vagal tone will typically discharge around 100x per minute. Hence the higher resting heart rate found in cardiac transplant cases. In the SA and AV nodes the resting membrane potential is lower than in surrounding cardiac cells and will slowly depolarise from -70mV to around -50mV at which point an action potential is generated. Differences in the depolarisation slopes between SA and AV nodes help to explain why the SA node will depolarise first. The cells have a refractory period during which they cannot be re-stimulated and this period allows for adequate ventricular filling. In pathological tachycardic states this time period is overridden and inadequate ventricular filling may then occur, cardiac output falls and syncope may ensue. Parasympathetic fibres project to the heart via the vagus and will release acetylcholine. Sympathetic fibres release nor adrenaline and circulating adrenaline comes from the adrenal medulla. Noradrenaline binds to β 1 receptors in the SA node and increases the rate of pacemaker potential depolarisation. Mid diastole: AV valves open. Ventricles hold 80% of final volume. Outflow valves shut. Aortic pressure is high. Late diastole: Atria contract. Ventricles receive 20% to complete filling. Typical end diastolic volume 130-160ml. Early systole: AV valves shut. Ventricular pressure rises. Isovolumetric ventricular contraction. AV Valves bulge into atria (c-wave). Aortic and pulmonary pressure exceeded- blood is ejected. Shortening of ventricles pulls atria downwards and drops intra atrial pressure (x-descent). Late systole: Ventricular muscles relax and ventricular pressures drop. Although ventricular pressure drops the aortic pressure remains constant owing to peripheral vascular resistance and elastic property of the aorta. Brief period of retrograde flow that occurs in aortic recoil shuts the aortic valve. Ventricles will contain 60ml end systolic volume. The average stroke volume is 70ml (i.e. Volume ejected). Early diastole: All valves are closed. Isovolumetric ventricular relaxation occurs. Pressure wave associated with closure of the aortic valve increases aortic pressure. The pressure dip before this rise can be seen on arterial waveforms and is called the incisura. During systole the atrial pressure increases such that it is now above zero (v- wave). Eventually atrial pressure exceed ventricular pressure and AV valves open - atria empty passively into ventricles and atrial pressure falls (y -descent ) The negative atrial pressures are of clinical importance as they can allow air embolization to occur if the neck veins are exposed to air. This patient positioning is important in head and neck surgery to avoid this occurrence if veins are inadvertently cut, or during CVP line insertion. Mechanical properties Preload = end diastolic volume Afterload = aortic pressure It is important to understand the principles of Laplace's law in surgery. It states that for hollow organs with a circular cross section, the total circumferential wall tension depends upon the circumference of the wall, multiplied by the thickness of the wall and on the wall tension. The total luminal pressure depends upon the cross sectional area of the lumen and the transmural pressure. Transmural pressure is the internal pressure minus external pressure and at equilibrium the total pressure must counterbalance each other. In terms of cardiac physiology the law explains that the rise in ventricular pressure that occurs during the ejection phase is due to physical change in heart size. It also explains why a dilated diseased heart will have impaired systolic function. Starlings law Increase in end diastolic volume will produce larger stroke volume. This occurs up to a point beyond which cardiac fibres are excessively stretched and stroke volume will fall once more. It is important for the regulation of cardiac output in cardiac transplant patients who need to increase their cardiac output. Baroreceptor reflexes Baroreceptors located in aortic arch and carotid sinus. Aortic baroreceptor impulses travel via the vagus and from the carotid via the glossopharyngeal nerve. They are stimulated by arterial stretch. Even at normal blood pressures they are tonically active. Increase in baroreceptor discharge causes: *Increased parasympathetic discharge to the SA node. *Decreased sympathetic discharge to ventricular muscle causing decreased contractility and fall in stroke volume. *Decreased sympathetic discharge to venous system causing increased compliance. *Decreased peripheral arterial vascular resistance Atrial stretch receptors Located in atria at junction between pulmonary veins and vena cava. Stimulated by atrial stretch and are thus low pressure sensors. Increased blood volume will cause increased parasympathetic activity. Very rapid infusion of blood will result in increase in heart rate mediated via atrial receptors: the Bainbridge reflex. Decreases in receptor stimulation results in increased sympathetic activity this will decrease renal blood flow-decreases GFR-decreases urinary sodium excretion-renin secretion by juxtaglomerular apparatus-Increase in angiotensin II. Increased atrial stretch will also result in increased release of atrial natriuretic peptide.

Answer 730

The left kidney lies in this location and is the most likely structure to be injured. The Spleen lies more superiorly, and the left adrenal and ureter are unlikely to be injured in isolation. Levels Transpyloric plane Level of the body of L1 Pylorus stomach Left kidney hilum (L1- left one!) Fundus of the gallbladder Neck of pancreas Duodenojejunal flexure Superior mesenteric artery Portal vein Left and right colic flexure Root of the transverse mesocolon 2nd part of the duodenum Upper part of conus medullaris Spleen Can be identified by asking the supine patient to sit up without using their arms. The plane is located where the lateral border of the rectus muscle crosses the costal margin. Anatomical planes Subcostal plane Lowest margin of 10th costal cartilage Intercristal plane Level of body L4 (highest point of iliac crest) Intertubercular plane Level of body L5 Common level landmarks Inferior mesenteric artery L3 Bifurcation of aorta into common iliac arteries L4 Formation of IVC L5 (union of common iliac veins) Diaphragm apertures Vena cava T8 Oesophagus T10 Aortic hiatus T12

Answer 731

The sciatic nerve most commonly arises from L4 to S3. Sciatic nerve The sciatic nerve is formed from the sacral plexus and is the largest nerve in the body. It is the continuation of the main part of the plexus arising from ventral rami of L4 to S3. These rami converge at the inferior border of piriformis to form the nerve itself. It passes through the inferior part of the greater sciatic foramen and emerges beneath piriformis. Medially, lie the inferior gluteal nerve and vessels and the pudendal nerve and vessels. It runs inferolaterally under the cover of gluteus maximus midway between the greater trochanter and ischial tuberosity. It receives its blood supply from the inferior gluteal artery. The nerve provides cutaneous sensation to the skin of the foot and the leg. It also innervates the posterior thigh muscles and the lower leg and foot muscles. The nerve splits into the tibial and common peroneal nerves approximately half way down the posterior thigh. The tibial nerve supplies the flexor muscles and the common peroneal nerve supplies the extensor muscles and the evertor muscles of the foot. Summary points Origin Spinal nerves L4 - S3 Articular Branches Hip joint Muscular branches in upper leg Semitendinosus Semimembranosus Biceps femoris Part of adductor magnus Cutaneous sensation Posterior aspect of thigh (via cutaneous nerves) Gluteal region Entire lower leg (except the medial aspect) Terminates At the upper part of the popliteal fossa by dividing into the tibial and peroneal nerves The nerve to the short head of the biceps femoris comes from the common peroneal part of the sciatic and the other muscular branches arise from the tibial portion. The tibial nerve goes on to innervate all muscles of the foot except the extensor digitorum brevis (which is innervated by the common peroneal nerve).

Answer 732

Contents of carotid sheath: Common carotid artery Internal carotid artery Internal jugular vein Vagus nerve Common carotid artery The right common carotid artery arises at the bifurcation of the brachiocephalic trunk, the left common carotid arises from the arch of the aorta. Both terminate at the level of the upper border of the thyroid cartilage (the lower border of the third cervical vertebra) by dividing into the internal and external carotid arteries. Left common carotid artery This vessel arises immediately to the left and slightly behind the origin of the brachiocephalic trunk. Its thoracic portion is 2.5- 3.5 cm in length and runs superolaterally to the sternoclavicular joint. In the thorax The vessel is in contact, from below upwards, with the trachea, left recurrent laryngeal nerve, left margin of the oesophagus. Anteriorly the left brachiocephalic vein runs across the artery, and the cardiac branches from the left vagus descend in front of it. These structures together with the thymus and the anterior margins of the left lung and pleura separate the artery from the manubrium. In the neck The artery runs superiorly deep to sternocleidomastoid and then enters the anterior triangle. At this point it lies within the carotid sheath with the vagus nerve and the internal jugular vein. Posteriorly the sympathetic trunk lies between the vessel and the prevertebral fascia. At the level of C7 the vertebral artery and thoracic duct lie behind it. The anterior tubercle of C6 transverse process is prominent and the artery can be compressed against this structure (it corresponds to the level of the cricoid). Anteriorly at C6 the omohyoid muscle passes superficial to the artery. Within the carotid sheath the jugular vein lies lateral to the artery. Right common carotid artery The right common carotid arises from the brachiocephalic artery. The right common carotid artery corresponds with the cervical portion of the left common carotid, except that there is no thoracic duct on the right. The oesophagus is less closely related to the right carotid than the left. Summary points about the carotid anatomy Path Passes behind the sternoclavicular joint (12% patients above this level) to the upper border of the thyroid cartilage, to divide into the external (ECA) and internal carotid arteries (ICA). Relations Level of 6th cervical vertebra crossed by omohyoid Then passes deep to the thyrohyoid, sternohyoid, sternomastoid muscles. Passes anterior to the carotid tubercle (transverse process 6th cervical vertebra)-NB compression here stops haemorrhage. The inferior thyroid artery passes posterior to the common carotid artery. Then : Left common carotid artery crosses the thoracic duct, Right common carotid artery crossed by recurrent laryngeal nerve

Answer 733

Most cases will settle with conservative management with NG decompression and appropriate support. Laparotomy should be undertaken in patients do not who progress despite conservative management or in whom compelling indications for surgery exist (eg free air). Paediatric Gastrointestinal disorders Pyloric stenosis M>F 5-10% Family history in parents Projectile non bile stained vomiting at 4-6 weeks of life Diagnosis is made by test feed or USS Treatment: Ramstedt pyloromyotomy (open or laparoscopic) Acute appendicitis Uncommon under 3 years When occurs may present atypically Mesenteric adenitis Central abdominal pain and URTI Conservative management Intussusception Telescoping bowel Proximal to or at the level of, ileocaecal valve 6-9 months age Colicky pain, diarrhoea and vomiting, sausage shaped mass, red jelly stool. Treatment: reduction with air insufflation Malrotation High caecum at the midline Feature in exomphalos, congenital diaphragmatic hernia, intrinsic duodenal atresia May be complicated by development of volvulus, infant with volvulus may have bile stained vomiting Diagnosis is made by upper GI contrast study and USS Treatment is by laparotomy, if volvulus is present (or at high risk of occurring then a ladds procedure is performed Hirschsprung's disease Absence of ganglion cells from myenteric and submucosal plexuses Occurs in 1/5000 births Full thickness rectal biopsy for diagnosis Delayed passage of meconium and abdominal distension Treatment is with rectal washouts initially, thereafter an anorectal pull through procedure Oesophageal atresia Associated with tracheo-oesophageal fistula and polyhydramnios May present with choking and cyanotic spells following aspiration VACTERL associations Meconium ileus Usually delayed passage of meconium and abdominal distension Majority have cystic fibrosis X-Rays may not show a fluid level as the meconium is viscid (depends upon feeding), PR contrast studies may dislodge meconium plugs and be therapeutic Infants who do not respond to PR contrast and NG N-acetyl cysteine will require surgery to remove the plugs Biliary atresia Jaundice > 14 days Increased conjugated bilirubin Urgent Kasai procedure Necrotising enterocolitis Prematurity is the main risk factor Early features include abdominal distension and passage of bloody stools X-Rays may show pneumatosis intestinalis and evidence of free air Increased risk when empirical antibiotics are given to infants beyond 5 days Treatment is with total gut rest and TPN, babies with perforations will require laparotomy

Answer 734

Type II respiratory failure This is a sign of acute type 2 respiratory failure (non compensated). This is the result of carbon dioxide retention. Metabolic acidosis This is the most common surgical acid - base disorder. Reduction in plasma bicarbonate levels. Two mechanisms: 1. Gain of strong acid (e.g. diabetic ketoacidosis) 2. Loss of base (e.g. from bowel in diarrhoea) - Classified according to the anion gap, this can be calculated by: (Na+ + K+) - (Cl- + HCO3-). - If a question supplies the chloride level then this is often a clue that the anion gap should be calculated. The normal range = 10-18 mmol/L Normal anion gap ( = hyperchloraemic metabolic acidosis) Gastrointestinal bicarbonate loss: diarrhoea, ureterosigmoidostomy, fistula Renal tubular acidosis Drugs: e.g. acetazolamide Ammonium chloride injection Addison's disease Raised anion gap Lactate: shock, hypoxia Ketones: diabetic ketoacidosis, alcohol Urate: renal failure Acid poisoning: salicylates, methanol Metabolic acidosis secondary to high lactate levels may be subdivided into two types: Lactic acidosis type A: (Perfusion disorders e.g.shock, hypoxia, burns) Lactic acidosis type B: (Metabolic e.g. metformin toxicity) Metabolic alkalosis Usually caused by a rise in plasma bicarbonate levels. Rise of bicarbonate above 24 mmol/L will typically result in renal excretion of excess bicarbonate. Caused by a loss of hydrogen ions or a gain of bicarbonate. It is due mainly to problems of the kidney or gastrointestinal tract Causes Vomiting / aspiration (e.g. Peptic ulcer leading to pyloric stenosis, nasogastric suction) Diuretics Liquorice, carbenoxolone Hypokalaemia Primary hyperaldosteronism Cushing's syndrome Bartter's syndrome Congenital adrenal hyperplasia Mechanism of metabolic alkalosis Activation of renin-angiotensin II-aldosterone (RAA) system is a key factor Aldosterone causes reabsorption of Na+ in exchange for H+ in the distal convoluted tubule ECF depletion (vomiting, diuretics) → Na+ and Cl- loss → activation of RAA system → raised aldosterone levels In hypokalaemia, K+ shift from cells → ECF, alkalosis is caused by shift of H+ into cells to maintain neutrality Respiratory acidosis Rise in carbon dioxide levels usually as a result of alveolar hypoventilation Renal compensation may occur leading to Compensated respiratory acidosis Causes COPD Decompensation in other respiratory conditions e.g. Life-threatening asthma / pulmonary oedema Sedative drugs: benzodiazepines, opiate overdose Respiratory alkalosis Hyperventilation resulting in excess loss of carbon dioxide This will result in increasing pH Causes Psychogenic: anxiety leading to hyperventilation Hypoxia causing a subsequent hyperventilation: pulmonary embolism, high altitude Early salicylate poisoning* CNS stimulation: stroke, subarachnoid haemorrhage, encephalitis Pregnancy *Salicylate overdose leads to a mixed respiratory alkalosis and metabolic acidosis. Early stimulation of the respiratory centre leads to a respiratory alkalosis whilst later the direct acid effects of salicylates (combined with acute renal failure) may lead to an acidosis

Answer 735

Metastatic cancer accounts for most cases of hypercalcaemia in hospitalised patients. In the community primary hyperparathyroidism is the commonest cause. Hypercalcaemia Main causes Malignancy (most common cause in hospital in-patients) Primary hyperparathyroidism (commonest cause in non hospitalised patients) Less common Sarcoidosis (extrarenal synthesis of calcitriol ) Thiazides, lithium Immobilisation Pagets disease Vitamin A/D toxicity Thyrotoxicosis MEN Milk alkali syndrome Clinical features Stones, bones, abdominal groans, and psychic moans High serum calcium levels result in decreased neuronal excitability. Therefore sluggish reflexes, muscle weakness and constipation may occur.

Answer 736

Thyrotoxicosis Diuretics increase the risk of re-feeding syndrome through a process of increasing the risk of depletion of key electrolytes. Nutrition - Refeeding syndrome Refeeding syndrome describes the metabolic abnormalities which occur on feeding a person following a period of starvation. The metabolic consequences include: Hypophosphataemia Hypokalaemia Hypomagnesaemia Abnormal fluid balance These abnormalities can lead to organ failure. Re-feeding problems If patient not eaten for > 5 days, aim to re-feed at < 50% energy and protein levels High risk for re-feeding problems If one or more of the following: BMI < 16 kg/m2 Unintentional weight loss >15% over 3-6 months Little nutritional intake > 10 days Hypokalaemia, Hypophosphataemia or hypomagnesaemia prior to feeding (unless high) If two or more of the following: BMI < 18.5 kg/m2 Unintentional weight loss > 10% over 3-6 months Little nutritional intake > 5 days History of: alcohol abuse, drug therapy including insulin, chemotherapy, diuretics and antacids Prescription Start at up to 10 kcal/kg/day increasing to full needs over 4-7 days Start immediately before and during feeding: oral thiamine 200-300mg/day, vitamin B co strong 1 tds and supplements Give K+ (2-4 mmol/kg/day), phosphate (0.3-0.6 mmol/kg/day), magnesium (0.2-0.4 mmol/kg/day)

Answer 737

Mesenteric cysts may be associated with intra abdominal catastrophes where these occur they are typically either intestinal volvulus or intestinal infarction. They seldom cause intussusception. Cystic fibrosis may lead to the formation of meconium ileus equivalent and plugs may occasionally serve as the lead points for an intussusception. Intussusception- Paediatric Intussusception typically presents with colicky abdominal pain and vomiting. The telescoping of the bowel produces mucosal ischaemia and bleeding may occur resulting in the passage of red current jelly stools. Recognised causes include lumenal pathologies such as polyps, lymphadenopathy and diseases such as cystic fibrosis. Idiopathic intussceception of the ileocaecal valve and terminal ileum is the most common variant and typically affects young children and toddlers. The diagnosis is usually made by abdominal ultrasound investigation. The decision as to the optimal treatment is dictated by the patients physiological status and abdominal signs. In general, children who are unstable with localising peritoneal signs should undergo laparotomy, as should those in whom attempted radiological reduction has failed. In relatively well children, without localising signs, attempted pneumatic reduction under fluroscopic guidance is the usual treatment. This is not done where there are concerns about impending perforation or if there is a small bowel intussusception.

Answer 738

Extraintestinal manifestation of inflammatory bowel disease: A PIE SAC Aphthous ulcers Pyoderma gangrenosum Iritis Erythema nodosum Sclerosing cholangitis Arthritis Clubbing Crohns disease Crohns disease is a chronic transmural inflammation of a segment(s) of the gastrointestinal tract and may be associated with extra intestinal manifestations. Frequent disease patterns observed include ileal, ileocolic and colonic disease. Peri-anal disease may occur in association with any of these. The disease is often discontinuous in its distribution. Inflammation may cause ulceration, fissures, fistulas and fibrosis with stricturing. Histology reveals a chronic inflammatory infiltrate that is usually patchy and transmural. Ulcerative colitis Vs Crohns Crohn's disease Ulcerative colitis Distribution Mouth to anus Rectum and colon Macroscopic changes Cobblestone appearance, apthoid ulceration Contact bleeding Depth of disease Transmural inflammation Superficial inflammation Distribution pattern Patchy Continuous Histological features Granulomas (non caseating epithelioid cell aggregates with Langhans' giant cells) Crypt abscesses, Inflammatory cells in the lamina propria Extraintestinal manifestations of Crohns Related to disease extent Unrelated to disease extent Aphthous ulcers (10%) Sacroiliiitis (10-15%) Erythema nodosum (5-10%) Ankylosing spondylitis (1-2%) Pyoderma gangrenosum (0.5%) Primary sclerosing cholangitis (Rare) Acute arthropathy (6-12%) Gallstones (up to 30%) Ocular complications (up to 10%) Renal calculi (up to 10%) Diarrhoea in Crohns Diarrhoea in Crohns may be multifactorial since actual inflammation of the colon is not common. Causes therefore include the following: Bile salt diarrhoea secondary to terminal ileal disease Entero-colic fistula Short bowel due to multiple resections Bacterial overgrowth Surgical interventions in Crohns disease The commonest disease pattern in Crohns is stricturing terminal ileal disease and this often culminates in an ileocaecal resection. Other procedures performed include segmental small bowel resections and stricturoplasty. Colonic involvement in patients with Crohns is not common and, where found, distribution is often segmental. However, despite this distribution segmental resections of the colon in patients with Crohns disease are generally not advocated because the recurrence rate in the remaining colon is extremely high. As a result, the standard options of colonic surgery in Crohns patients are generally; sub total colectomy, panproctocolectomy and staged sub total colectomy and proctectomy. Restorative procedures such as ileoanal pouch have no role in therapy. Crohns disease is notorious for the developmental of intestinal fistulae; these may form between the rectum and skin (peri anal) or the small bowel and skin. Fistulation between loops of bowel may also occur and result in bacterial overgrowth and malabsorption. Management of enterocutaneous fistulae involves controlling sepsis, optimising nutrition, imaging the disease and planning definitive surgical management.

Answer 739

Prostate cancers are typically biopsied prior to treatment. Prostate Cancer Prostate Cancer This is a common condition and up to 30,000 men are diagnosed with the condition each year. Up to 9,000 will die in in the UK from the condition per year. Diagnosis Early prostate cancers have few symptoms. Metastatic disease may present as bone pain. Locally advanced disease may present as pelvic pain or with urinary symptoms. Prostate specific antigen measurement Digital rectal examination Trans rectal USS (+/- biopsy) MRI/ CT and bone scan for staging. PSA Test The normal upper limit for PSA is 4ng/ml. However, in this group will lie patients with benign disease and some with localised prostate cancer. False positives may be due to prostatitis, UTI, BPH, vigorous DRE. The percentage of free: total PSA may help to distinguish benign disease from cancer. Values of <20% are suggestive of cancer and biopsy is advised. Pathology 95% adenocarcinoma In situ malignancy is sometimes found in areas adjacent to cancer. Multiple biopsies needed to call true in situ disease. Often multifocal- 70% lie in the peripheral zone. Graded using the Gleason grading system, two grades awarded 1 for most dominant grade (on scale of 1-5) and 2 for second most dominant grade (scale 1-5). The two added together give the Gleason score. Where 2 is best prognosis and 10 the worst. Lymphatic spread occurs first to the obturator nodes and local extra prostatic spread to the seminal vesicles is associated with distant disease. Treatment Watch and wait- Elderly, multiple co-morbidities, low Gleason score Radiotherapy (External)- Both potentially curative and palliative therapy possible. However, radiation proctitis and rectal malignancy are late problems. Brachytherapy is a modification allowing internal radiotherapy. Surgery- Radical prostatectomy. Surgical removal of the prostate is the standard treatment for localised disease. The robot is being used increasingly for this procedure. As well as the prostate the obturator nodes are also removed to complement the staging process. Erectile dysfunction is a common side effect. Survival may be better than with radiotherapy (see references). Functional outcomes are better when a robotic approach is used. Hormonal therapy- Testosterone stimulates prostate tissue and prostatic cancers usually show some degree of testosterone dependence. 95% of testosterone is derived from the testis and bilateral orchidectomy may be used for this reason. Pharmacological alternatives include LHRH analogues and anti androgens (which may be given in combination). In the UK the National Institute for Clinical Excellence (NICE) suggests that active surveillance is the preferred option for low risk men. It is particularly suitable for men with clinical stage T1c, Gleason score 3+3 and PSA density < 0.15 ng/ml/ml who have cancer in less than 50% of their biopsy cores, with < 10 mm of any core involved. Candidates for active surveillance should: have had at least 10 biopsy cores taken have at least one re-biopsy. If men on active surveillance show evidence of disease progression, offer radical treatment. Treatment decisions should be made with the man, taking into account co-morbidities and life expectancy. References 1. Prostate cancer pathway. NICE.(http://guidance.nice.org.uk/IPG424) 2. Sooriakumaran P et al. Comparative effectiveness of radical prostatectomy and radiotherapy in prostate cancer: observational study of mortality outcomes. BMJ 2014 (348):13. This study shows that in men with localised disease survival was greater in those offered surgery.

Answer 740

In an existing lesion a complication such as thrombosis is more likely than embolus. These patients should receive heparin and imaging with duplex scanning. Whilst an early surgical bypass or intra-arterial thrombolysis may be indicated, an embolectomy should not generally be performed as the lesion is not an embolus and the operation therefore ineffective. Claudication Claudication is a condition in which patients develop pain in a limb during periods of exercise. The underlying disorder is usually that of arterial insufficiency. Atheroma develops in the arterial wall and once this occludes >50-75% of the lumenal diameter the supply to metabolising tissues distally may become compromised. The typical claudicant complains of calf pain that is worse on exercise and relieved by rest. This typical description assumes that the SFA is the site of disease, more proximal disease may present with other symptoms such as buttock claudication and impotence. The history is usually a progressive one, patients presenting as an emergency with severe pain, diminished sensation, pallor and absent pulses have critical limb ischaemia. This may complicate claudication and usually indicates a plaque related complication, such as thrombosis. Risk factors Risk factors for claudication include smoking, diabetes and hyperlipidaemia. Diagnosis Diagnostic work -up includes measurement of ankle- brachial pressure indices, duplex scanning and formal angiography. Treatment Those with long claudication distances, no ulceration or gangrene may be managed conservatively. Patients with rest pain, ulceration or gangrene will almost always require intervention. All patients should receive an antiplatelet agent and a statin unless there are compelling contra-indications.

Answer 741

This scenario should raise suspicion for Meckels as these may contain ectopic gastric mucosa which may secrete acid with subsequent bleeding and ulceration. The iron deficiency anaemia makes a Meckels more likely than IBS. Right iliac fossa pain Differential diagnosis Appendicitis Pain radiating to right iliac fossa Anorexia (very common) Short history Diarrhoea and profuse vomiting rare Crohn's disease Often long history Signs of malnutrition Change in bowel habit, especially diarrhoea Mesenteric adenitis Mainly affects children Causes include Adenoviruses, Epstein Barr Virus, beta-haemolytic Streptococcus, Staphylococcus spp., Escherichia coli, Streptococcus viridans and Yersinia spp. Patients have a higher temperature than those with appendicitis If laparotomy is performed, enlarged mesenteric lymph nodes will be present Diverticulitis Both left and right sided disease may present with right iliac fossa pain Clinical history may be similar, although some change in bowel habit is usual When suspected, a CT scan may help in refining the diagnosis Meckel's diverticulitis A Meckel's diverticulum is a congenital abnormality that is present in about 2% of the population Typically 2 feet proximal to the ileocaecal valve May be lined by ectopic gastric mucosal tissue and produce bleeding Perforated peptic ulcer This usually produces upper quadrant pain but pain may be lower Perforations typically have a sharp sudden onset of pain in the history Incarcerated right inguinal or femoral hernia Usually only right iliac fossa pain if right sided or bowel obstruction. Bowel perforation secondary to caecal or colon carcinoma Seldom localised to right iliac fossa, although complete large bowel obstruction with caecal distension may cause pain prior to perforation. Gynaecological causes Pelvic inflammatory disease/salpingitis/pelvic abscess/Ectopic pregnancy/Ovarian torsion/Threatened or complete abortion/Mittelschmerz Urological causes Ureteric colic/UTI/Testicular torsion Other causes TB/Typhoid/Herpes Zoster/AAA/Situs inversus

Answer 742

Rule of thirds: 1/3 multiple 1/3 small bowel 1/3 metastasize 1/3 second tumour Carcinoids secrete serotonin. Carcinoid syndrome will only occur in the presence of liver metastasis as the hormone released from primary lesions will typically be metabolised by the liver. Carcinoid syndrome Carcinoid tumours secrete serotonin Originate in neuroendocrine cells mainly in the intestine (midgut-distal ileum/appendix) Can occur in the rectum, bronchi Hormonal symptoms mainly occur when disease spreads outside the bowel Clinical features Onset: insidious over many years Flushing face Palpitations Pulmonary valve stenosis and tricuspid regurgitation causing dyspnoea Asthma Severe diarrhoea (secretory, persists despite fasting) Investigation 5-HIAA in a 24-hour urine collection Somatostatin receptor scintigraphy CT scan Blood testing for chromogranin A Treatment Octreotide Surgical removal

Answer 743

Comedo type DCIS is usually associated with microcalcifications. Cribriform lesions are usually multifocal but less likely to form microcalcifications. Lobular cancers and in situ lesions rarely form microcalcifications and are difficult to detect using mammography. Breast cancer - In situ disease Breast cancer that has yet to invade the basement membrane is referred to as in situ disease. Both ductal and lobular in situ variants are recognised. Ductal carcinoma in situ Sub types include; comedo, cribriform, micropapillary and solid Comdeo DCIS is most likely to form microcalcifications Cribriform and micropapillary are most likely to be multifocal Most lesions are mixed (composed of multiple subtypes) High nuclear grade DCIS is associated with more malignant characteristics (loss of p53, increased erbB2 expression) Local excision of low nuclear grade DCIS will usually produce satisfactory outcomes. Multifocal lesions, large and high nuclear grade lesions will usually require mastectomy Whole breast irradiation improves locoregional control when breast conserving surgery is performed Lobular carcinoma in situ Much rarer than DCIS Does not form microcalcifications Usually single growth pattern When an invasive component is found it is less likely to be associated with axillary nodal metastasis than with invasive foci found within DCIS Low grade LCIS is usually treated by monitoring rather than excision

Answer 744

At its lower end the carotid sheath is related to sternohyoid and sternothyroid. Opposite the cricoid cartilage the sheath is crossed by the superior belly of omohyoid. Above this level the sheath is covered by the sternocleidomastoid muscle. Above the level of the hyoid the vessels pass deep to the posterior belly of digastric and stylohyoid. Opposite the hyoid bone the sheath is crossed obliquely by the hypoglossal nerve. Common carotid artery The right common carotid artery arises at the bifurcation of the brachiocephalic trunk, the left common carotid arises from the arch of the aorta. Both terminate at the level of the upper border of the thyroid cartilage (the lower border of the third cervical vertebra) by dividing into the internal and external carotid arteries. Left common carotid artery This vessel arises immediately to the left and slightly behind the origin of the brachiocephalic trunk. Its thoracic portion is 2.5- 3.5 cm in length and runs superolaterally to the sternoclavicular joint. In the thorax The vessel is in contact, from below upwards, with the trachea, left recurrent laryngeal nerve, left margin of the oesophagus. Anteriorly the left brachiocephalic vein runs across the artery, and the cardiac branches from the left vagus descend in front of it. These structures together with the thymus and the anterior margins of the left lung and pleura separate the artery from the manubrium. In the neck The artery runs superiorly deep to sternocleidomastoid and then enters the anterior triangle. At this point it lies within the carotid sheath with the vagus nerve and the internal jugular vein. Posteriorly the sympathetic trunk lies between the vessel and the prevertebral fascia. At the level of C7 the vertebral artery and thoracic duct lie behind it. The anterior tubercle of C6 transverse process is prominent and the artery can be compressed against this structure (it corresponds to the level of the cricoid). Anteriorly at C6 the omohyoid muscle passes superficial to the artery. Within the carotid sheath the jugular vein lies lateral to the artery. Right common carotid artery The right common carotid arises from the brachiocephalic artery. The right common carotid artery corresponds with the cervical portion of the left common carotid, except that there is no thoracic duct on the right. The oesophagus is less closely related to the right carotid than the left. Summary points about the carotid anatomy Path Passes behind the sternoclavicular joint (12% patients above this level) to the upper border of the thyroid cartilage, to divide into the external (ECA) and internal carotid arteries (ICA). Relations Level of 6th cervical vertebra crossed by omohyoid Then passes deep to the thyrohyoid, sternohyoid, sternomastoid muscles. Passes anterior to the carotid tubercle (transverse process 6th cervical vertebra)-NB compression here stops haemorrhage. The inferior thyroid artery passes posterior to the common carotid artery. Then : Left common carotid artery crosses the thoracic duct, Right common carotid artery crossed by recurrent laryngeal nerve

Answer 745

The lunate lies medially in the anatomical plane. Fractures of the scaphoid that are associated with high velocity injuries may cause associated lunate dislocation. Scaphoid bone The scaphoid has a concave articular surface for the head of the capitate and at the edge of this is a crescentic surface for the corresponding area on the lunate. Proximally, it has a wide convex articular surface with the radius. It has a distally sited tubercle that can be palpated. The remaining articular surface is to the lateral side of the tubercle. It faces laterally and is associated with the trapezium and trapezoid bones. The narrow strip between the radial and trapezial surfaces and the tubercle gives rise to the radial collateral carpal ligament. Blood supply This is from the scaphoid tubercle vessels that comprise 20% and the dorsal ridge vessels that supply 80%.

Answer 746

Lacunar ligament The femoral canal and the femoral triangle are distinct anatomical structures. Do not confuse them, especially in the time pressured exam situation. Femoral canal The femoral canal lies at the medial aspect of the femoral sheath. The femoral sheath is a fascial tunnel containing both the femoral artery laterally and femoral vein medially. The canal lies medial to the vein. Borders of the femoral canal Laterally Femoral vein Medially Lacunar ligament Anteriorly Inguinal ligament Posteriorly Pectineal ligament Contents Lymphatic vessels Cloquet's lymph node Physiological significance Allows the femoral vein to expand to allow for increased venous return from the lower limbs. Pathological significance As a potential space, it is the site of femoral hernias. The relatively tight neck places these at high risk of strangulation.

Answer 747

The trochlear nerve has a relatively long intracranial course and this makes it vulnerable to injury in head trauma. Head trauma is the commonest cause of an acute fourth nerve palsy. A 4th nerve palsy is the commonest cause of a vertical diplopia. The diplopia is at its worst when the eye looks medially which it usually does as part of the accommodation reflex when walking down stairs. Disorders of the oculomotor system Nerve Path Nerve palsy features Oculomotor nerve Large nucleus at the midbrain Fibres pass through the red nucleus and the pyramidal tract; through the cavernous sinus into the orbit Ptosis Eye down and out Unable to move the eye superiorly, inferiorly, medially Pupil fixed and dilated Trochlear nerve Longest intracranial course Only nerve to exit the dorsal aspect of brainstem Nucleus at midbrain, passes between the posterior cerebral and superior cerebellar arteries, through the cavernous sinus into the orbit Vertical diplopia (diplopia on descending the stairs) Unable to look down and in Abducens nerve Nucleus lies in the mid pons Convergence of eyes in primary position Lateral diplopia towards side of lesion Eye deviates medially

Answer 748

Cranial nerves carrying parasympathetic fibres X IX VII III (1973) The parasympathetic functions served by the cranial nerves include: III (oculomotor) Pupillary constriction and accommodation VII (facial) Lacrimal gland, submandibular and sublingual glands IX (glossopharyngeal) Parotid X (vagus) Heart and abdominal viscera The optic nerve carries no parasympathetic fibres. The cranial preganglionic parasympathetic nerves arise from specific nuclei in the CNS. These synapse at one of four parasympathetic ganglia; otic, pterygopalatine, ciliary and submandibular. From these ganglia the parasympathetic nerves complete their journey to their target tissues via CN V (trigeminal) branches (ophthalmic nerve CNV branch 1, Maxillary nerve CN V branch2, mandibular nerve CN V branch 3) Cranial nerves Cranial nerve lesions Olfactory nerve May be injured in basal skull fractures or involved in frontal lobe tumour extension. Loss of olfactory nerve function in relation to major CNS pathology is seldom an isolated event and thus it is poor localiser of CNS pathology. Optic nerve Problems with visual acuity may result from intra ocular disorders. Problems with the blood supply such as amaurosis fugax may produce temporary visual distortion. More important surgically is the pupillary response to light. The pupillary size may be altered in a number of disorders. Nerves involved in the resizing of the pupil connect to the pretectal nucleus of the high midbrain, bypassing the lateral geniculate nucleus and the primary visual cortex. From the pretectal nucleus neurones pass to the Edinger - Westphal nucleus, motor axons from here pass along with the oculomotor nerve. They synapse with ciliary ganglion neurones; the parasympathetic axons from this then innervate the iris and produce miosis. The miotic pupil is seen in disorders such as Horner's syndrome or opiate overdose. Mydriasis is the dilatation of the pupil in response to disease, trauma, drugs (or the dark!). It is pathological when light fails to induce miosis. The radial muscle is innervated by the sympathetic nervous system. Because the parasympathetic fibres travel with the oculomotor nerve they will be damaged by lesions affecting this nerve (e.g. cranial trauma). The response to light shone in one eye is usually a constriction of both pupils. This indicates intact direct and consensual light reflexes. When the optic nerve has an afferent defect the light shining on the affected eye will produce a diminished pupillary response in both eyes. Whereas light shone on the unaffected eye will produce a normal pupillary response in both eyes. This is referred to as the Marcus Gunn pupil and is seen in conditions such as optic neuritis. In a total CN II lesion shining the light in the affected eye will produce no response. Oculomotor nerve The pupillary effects are described above. In addition it supplies all ocular muscles apart from lateral rectus and superior oblique. Thus the affected eye will be deviated inferolaterally. Levator palpebrae superioris may also be impaired resulting in impaired ability to open the eye. Trochlear nerve The eye will not be able to look down. Trigeminal nerve Largest cranial nerve. Exits the brainstem at the pons. Branches are ophthalmic, maxillary and mandibular. Only the mandibular branch has both sensory and motor fibres. Branches converge to form the trigeminal ganglion (located in Meckels cave). It supplies the muscles of mastication and also tensor veli palatine, mylohyoid, anterior belly of digastric and tensor tympani. The detailed descriptions of the various sensory functions are described in other areas of the website. The corneal reflex is important and is elicited by applying a small tip of cotton wool to the cornea, a reflex blink should occur if it is intact. It is mediated by: the naso ciliary branch of the ophthalmic branch of the trigeminal (sensory component) and the facial nerve producing the motor response. Lesions of the afferent arc will produce bilateral absent blink and lesions of the efferent arc will result in a unilateral absent blink. Abducens nerve The affected eye will have a deficit of abduction. This cranial nerve exits the brainstem between the pons and medulla. It thus has a relatively long intra cranial course which renders it susceptible to damage in raised intra cranial pressure. Facial nerve Emerges from brainstem between pons and medulla. It controls muscles of facial expression and taste from the anterior 2/3 of the tongue. The nerve passes into the petrous temporal bone and into the internal auditory meatus. It then passes through the facial canal and exits at the stylomastoid foramen. It passes through the parotid gland and divides at this point. It does not innervate the parotid gland. Its divisions are considered in other parts of the website. Its motor fibres innervate orbicularis oculi to produce the efferent arm of the corneal reflex. In surgical practice it may be injured during parotid gland surgery or invaded by malignancies of the gland and a lower motor neurone on the ipsilateral side will result. Vestibulo-cochlear nerve Exits from the pons and then passes through the internal auditory meatus. It is implicated in sensorineural hearing loss. Individuals with sensorineural hearing loss will localise the sound in webers test to the normal ear. Rinnes test will be reduced on the affected side but should still work. These two tests will distinguish sensorineural hearing loss from conductive deafness. In the latter condition webers test will localise to the affected ear and Rinnes test will be impaired on the affected side. Surgical lesions affecting this nerve include CNS tumours and basal skull fractures. It may also be damaged by the administration of ototoxic drugs (of which gentamicin is the most commonly used in surgical practice). Glossopharyngeal nerve Exits the pons just above the vagus. Receives sensory fibres from posterior 1/3 tongue, tonsils, pharynx and middle ear (otalgia may occur following tonsillectomy). It receives visceral afferents from the carotid bodies. It supplies parasympathetic fibres to the parotid gland via the otic ganglion and motor function to stylopharyngeaus muscle. The sensory function of the nerve is tested using the gag reflex. Vagus nerve Leaves the medulla between the olivary nucleus and the inferior cerebellar peduncle. Passes through the jugular foramen and into the carotid sheath. Details of the functions of the vagus nerve are covered in the website under relevant organ sub headings. Accessory nerve Exists from the caudal aspect of the brainstem (multiple branches) supplies trapezius and sternocleidomastoid muscles. The distal portion of this nerve is most prone to injury during surgical procedures. Hypoglossal nerve Emerges from the medulla at the preolivary sulcus, passes through the hypoglossal canal. It lies on the carotid sheath and passes deep to the posterior belly of digastric to supply muscles of the tongue (except palatoglossus). Its location near the carotid sheath makes it vulnerable during carotid endarterectomy surgery and damage will produce ipsilateral defect in muscle function.

Answer 749

A combination of a high reticulocyte count and severe anaemia indicates sickle cell anaemia, however another differential can be of a transient aplastic crisis due to parvovirus. This is less likely as this causes a reticulocytopenia rather than a reticulocytosis. Parvovirus B19 infects erythroid progenitor cells in the bone marrow and causes temporary cessation of red blood cell production, patients who have underlying hematologic abnormalities are at risk of cessation of red blood cell production if they become infected. This can result in a transient aplastic crisis. Thus, patients with sickle cell anaemia are at risk. Typically, these patients have a viral prodrome followed by anaemia, often with haemoglobin concentrations falling below 5.0 g/dL and reticulocytopenia. Sickle cell anaemia Autosomal recessive Single base mutation Deoxygenated cells become sickle in shape Causes: short red cell survival, obstruction of microvessels and infarction Sickling is precipitated by: dehydration, infection, hypoxia Manifest at 6 months age Africans, Middle East, Indian Diagnosis: Hb electrophoresis Sickle crises Bone pain Pleuritic chest pain: acute sickle chest syndrome commonest cause of death CVA, seizures Papillary necrosis Splenic infarcts Priapism Hepatic pain Hb does not fall during a crisis, unless there is Aplasia: parvovirus Acute sequestration Haemolysis Long-term complications Infections: Streptococcus pnemoniae Chronic leg ulcers Gallstones: haemolysis Aseptic necrosis of bone Chronic renal disease Retinal detachment, proliferative retinopathy Surgical complications Bowel ischaemia Cholecystitis Avascular necrosis Management Supportive Hydroxyurea Repeated transfusions pre operatively Exchange transfusion in emergencies Sickle cell trait Heterozygous state Asymptomatic Symptoms associated with extreme situations ie anaesthesia complications Protective against Plasmodium falciparum

Answer 750

It has a different structure. It is much more lipid soluble than morphine. It produces less biliary tract spasm than morphine. Management of pain World Health Organisation Analgesic Ladder Initially peripherally acting drugs such as paracetamol or non-steroidal anti-inflammatory drugs (NSAIDs) are given. If pain control is not achieved, the second part of the ladder is to introduce weak opioid drugs such as codeine or dextropropoxyphene together with appropriate agents to control and minimise side effects. The final rung of the ladder is to introduce strong opioid drugs such as morphine. Analgesia from peripherally acting drugs may be additive to that from centrally-acting opioids and thus, the two are given together. The World Federation of Societies of Anaesthesiologists (WFSA) Analgesic Ladder For management of acute pain Initially, the pain can be expected to be severe and may need controlling with strong analgesics in combination with local anaesthetic blocks and peripherally acting drugs. The second rung on the postoperative pain ladder is the restoration of the use of the oral route to deliver analgesia. Strong opioids may no longer be required and adequate analgesia can be obtained by using combinations of peripherally acting agents and weak opioids. The final step is when the pain can be controlled by peripherally acting agents alone. Local anaesthetics Infiltration of a wound with a long-acting local anaesthetic such as Bupivacaine Analgesia for several hours Further pain relief can be obtained with repeat injections or by infusions via a thin catheter Blockade of plexuses or peripheral nerves will provide selective analgesia in those parts of the body supplied by the plexus or nerves Can either be used to provide anaesthesia for the surgery or specifically for postoperative pain relief Especially useful where a sympathetic block is needed to improve postoperative blood supply or where central blockade such as spinal or epidural blockade is contraindicated. Spinal anaesthesia Provides excellent analgesia for surgery in the lower half of the body and pain relief can last many hours after completion of the operation if long-acting drugs containing vasoconstrictors are used. - Side effects of spinal anaesthesia include: hypotension, sensory and motor block, nausea and urinary retention. Epidural anaesthesia An indwelling epidural catheter inserted. This can then be used to provide a continuous infusion of analgesic agents. It can provide excellent analgesia. They are still the preferred option following major open abdominal procedures and help prevent post operative respiratory compromise resulting from pain. - Disadvantages of epidurals is that they usually confine patients to bed, especially if a motor block is present. In addition an indwelling urinary catheter is required. Which may not only impair mobility but also serve as a conduit for infection. They are contraindicated in coagulopathies. Transversus Abdominal Plane block (TAP) In this technique an ultrasound is used to identify the correct muscle plane and local anaesthetic (usually bupivicaine) is injected. The agent diffuses in the plane and blocks many of the spinal nerves. It is an attractive technique as it provides a wide field of blockade but does not require the placement of any indwelling devices. There is no post operative motor impairment. For this reason it is the preferred technique when extensive laparoscopic abdominal procedures are performed. They will then provide analgesia immediately following surgery but as they do not confine the patient to bed, the focus on enhanced recovery can begin sooner. -The main disadvantage is that their duration of action is limited to the half life of the local anaesthetic agent chosen. In addition some anaesthetists do not have the USS skills required to site the injections. Patient Controlled Analgesia (PCA) - Patients administer their own intravenous analgesia and titrate the dose to their own end-point of pain relief using a small microprocessor - controlled pump. Morphine is the most popular drug used. Strong Opioids Severe pain arising from deep or visceral structures requires the use of strong opioids Morphine Short half life and poor bioavailability. Metabolised in the liver and clearance is reduced in patients with liver disease, in the elderly and the debilitated Side effects include nausea, vomiting, constipation and respiratory depression. Tolerance may occur with repeated dosage Pethidine Synthetic opioid which is structurally different from morphine but which has similar actions. Has 10% potency of morphine. Short half life and similar bioavailability and clearance to morphine. Short duration of action and may need to be given hourly. Pethidine has a toxic metabolite (norpethidine) which is cleared by the kidney, but which accumulates in renal failure or following frequent and prolonged doses and may lead to muscle twitching and convulsions. Extreme caution is advised if pethidine is used over a prolonged period or in patients with renal failure. Weak opioids Codeine: markedly less active than morphine, has predictable effects when given orally and is effective against mild to moderate pain. Non opioid analgesics - Mild to moderate pain. Paracetamol Inhibits prostaglandin synthesis. Analgesic and antipyretic properties but little anti-inflammatory effect It is well absorbed orally and is metabolised almost entirely in the liver Side effects in normal dosage and is widely used for the treatment of minor pain. It causes hepatotoxicity in over dosage by overloading the normal metabolic pathways with the formation of a toxic metabolite. NSAIDs Analgesic and anti-inflammatory actions Inhibition of prostaglandin synthesis by the enzyme Cyclooxygenase which catalyses the conversion of arachidonic acid to the various prostaglandins that are the chief mediators of inflammation. All NSAIDs work in the same way and thus there is no point in giving more than one at a time. . NSAIDs are, in general, more useful for superficial pain arising from the skin, buccal mucosa, joint surfaces and bone. Relative contraindications: history of peptic ulceration, gastrointestinal bleeding or bleeding diathesis; operations associated with high blood loss, asthma, moderate to severe renal impairment, dehydration and any history of hypersensitivity to NSAIDs or aspirin. Neuropathic pain National Institute of Clinical Excellence (UK) guidelines: First line: Amitriptyline (Imipramine if cannot tolerate) or pregabalin Second line: Amitriptyline AND pregabalin Third line: refer to pain specialist. Give tramadol in the interim (avoid morphine) If diabetic neuropathic pain: Duloxetine As of 1 April 2019, pregabalin and gabapentin are Class C controlled substances (under the Misuse of Drugs Act 1971) and scheduled under the Misuse of Drugs Regulations 2001 as Schedule 3. Evaluate patients carefully for a history of drug abuse before prescribing and observe patients for development of signs of abuse and dependence (MHRA, Drug Safety Update April 2019). References 1. http://guidance.nice.org.uk/CG173/Guidance/pdf/English 2. Lovich-Sapola J, Smith CE, Brandt CP. Post operative pain control. Surg Clin North Am. 2015 Apr;95(2):301-183. Finnerup N et al. Pharmacotherapy for neuropathic pain in adults: a systematic review and meta-analysis. Lancet Neurol. 2015 Feb;14(2):162-73.

Answer 751

The triceps will not be affected so elbow extension will be preserved. Loss of wrist extension will be the most obvious effect. Radial nerve Continuation of posterior cord of the brachial plexus (root values C5 to T1) Path In the axilla: lies posterior to the axillary artery on subscapularis, latissimus dorsi and teres major. Enters the arm between the brachial artery and the long head of triceps (medial to humerus). Spirals around the posterior surface of the humerus in the groove for the radial nerve. At the distal third of the lateral border of the humerus it then pierces the intermuscular septum and descends in front of the lateral epicondyle. At the lateral epicondyle it lies deeply between brachialis and brachioradialis where it then divides into a superficial and deep terminal branch. Deep branch crosses the supinator to become the posterior interosseous nerve. Regions innervated Motor (main nerve) Triceps Anconeus Brachioradialis Extensor carpi radialis Motor (posterior interosseous branch) Supinator Extensor carpi ulnaris Extensor digitorum Extensor indicis Extensor digiti minimi Extensor pollicis longus and brevis Abductor pollicis longus Sensory The area of skin supplying the proximal phalanges on the dorsal aspect of the hand is supplied by the radial nerve (this does not apply to the little finger and part of the ring finger) Muscular innervation and effect of denervation Anatomical location Muscle affected Effect of paralysis Shoulder Long head of triceps Minor effects on shoulder stability in abduction Arm Triceps Loss of elbow extension Forearm Supinator Brachioradialis Extensor carpi radialis longus and brevis Weakening of supination of prone hand and elbow flexion in mid prone position

Answer 752

This man is unstable, and at 7 hours after extraction, the limb is not viable. The safest option is primary amputation. Fracture management Bony injury resulting in a fracture may arise from trauma (excessive forces applied to bone), stress related (repetitive low velocity injury) or pathological (abnormal bone which fractures during normal use of following minimal trauma) Diagnosis involves not just evaluating the fracture ; such as site and type of injury but also other associated injuries and distal neurovascular deficits. This may entail not just clinical examination but radiographs of proximal and distal joints. When assessing x-rays it is important to assess for changes in length of the bone, the angulation of the distal bone, rotational effects, presence of material such as glass. Fracture types Fracture type Description Oblique fracture Fracture lies obliquely to long axis of bone Comminuted fracture >2 fragments Segmental fracture More than one fracture along a bone Transverse fracture Perpendicular to long axis of bone Spiral fracture Severe oblique fracture with rotation along long axis of bone Open Vs Closed It is also important to distinguish open from closed injuries. The most common classification system for open fractures is the Gustilo and Anderson classification system (given below): Grade Injury 1 Low energy wound <1cm 2 Greater than 1cm wound with moderate soft tissue damage 3 High energy wound > 10cm with extensive soft tissue damage 3 A (sub group of 3) Adequate soft tissue coverage 3 B (sub group of 3) Inadequate soft tissue coverage 3 C (sub group of 3) Associated arterial injury Key points in management of fractures Immobilise the fracture including the proximal and distal joints Carefully monitor and document neurovascular status, particularly following reduction and immobilisation Manage infection including tetanus prophylaxis IV broad spectrum antibiotics for open injuries As a general principle all open fractures should be thoroughly debrided ( and internal fixation devices avoided or used with extreme caution) Open fractures constitute an emergency and should be debrided and lavaged within 6 hours of injury

Answer 753

There are 8 muscles: 1. Two flexors (flexor pollicis brevis and flexor pollicis longus) 2. Two extensors (extensor pollicis brevis and longus) 3. Two abductors (abductor pollicis brevis and longus) 4. One adductor (adductor pollicis) 5. One muscle that opposes the thumb by rotating the CMC joint (opponens pollicis). Flexor and extensor longus insert on the distal phalanx moving both the MCP and IP joints. Hand Anatomy of the hand Bones 8 Carpal bones 5 Metacarpals 14 phalanges Intrinsic Muscles 8 Interossei - Supplied by ulnar nerve 4 palmar-adduct fingers 4 dorsal- abduct fingers Intrinsic muscles Lumbricals Flex MCPJ and extend the IPJ. Origin deep flexor tendon and insertion dorsal extensor hood mechanism. Innervation: 1st and 2nd- median nerve, 3rd and 4th- deep branch of the ulnar nerve. Thenar eminence Abductor pollicis brevis Opponens pollicis Flexor pollicis brevis Hypothenar eminence Opponens digiti minimi Flexor digiti minimi brevis Abductor digiti minimi Image sourced from Wikipedia Fascia and compartments of the palm The fascia of the palm is continuous with the antebrachial fascia and the fascia of the dorsum of the hand. The palmar fascia is thin over the thenar and hypothenar eminences. In contrast, the central palmar fascia is relatively thick. The palmar aponeurosis covers the soft tissues and overlies the flexor tendons. The apex of the palmar aponeurosis is continuous with the flexor retinaculum and the palmaris longus tendon. Distally, it forms four longitudinal digital bands that attach to the bases of the proximal phalanges, blending with the fibrous digital sheaths. A medial fibrous septum extends deeply from the medial border of the palmar aponeurosis to the 5th metacarpal. Lying medial to this are the hypothenar muscles. In a similar fashion, a lateral fibrous septum extends deeply from the lateral border of the palmar aponeurosis to the 3rd metacarpal. The thenar compartment lies lateral to this area. Lying between the thenar and hypothenar compartments is the central compartment. It contains the flexor tendons and their sheaths, the lumbricals, the superficial palmar arterial arch and the digital vessels and nerves. The deepest muscular plane is the adductor compartment, which contains adductor pollicis. Short muscles of the hand These comprise the lumbricals and interossei. The four slender lumbrical muscles flex the fingers at the metacarpophalangeal joints and extend the interphalangeal joint. The four dorsal interossei are located between the metacarpals and the four palmar interossei lie on the palmar surface of the metacarpals in the interosseous compartment of the hand. Long flexor tendons and sheaths in the hand The tendons of FDS and FDP enter the common flexor sheath deep to the flexor retinaculum. The tendons enter the central compartment of the hand and fan out to their respective digital synovial sheaths. Near the base of the proximal phalanx, the tendon of FDS splits to permit the passage of FDP. The FDP tendons are attached to the margins of the anterior aspect of the base of the distal phalanx. The fibrous digital sheaths contain the flexor tendons and their synovial sheaths. These extend from the heads of the metacarpals to the base of the distal phalanges. Palmar Interossei Note that there are 4 palmar interossei. The first is a small slip of muscle which arises from the ulnar side of the base of the first metacarpal and passes between the head of the first dorsal interosseous and the oblique head of adductor pollicis to insert into the ulnar base of the of the proximal phalanx of the thumb. The second arises from the ulnar side of the body of the second metacarpal and is inserted into the ulnar side of the extensor hood of the index. The third and fourth palmar interossei arise from the radial sides of the bodies of the 4th and 5th metacarpals respectively and insert into the radial sides of the extensor hoods of the ring and little fingers.

Answer 754

The coccygeus, pubococcygeus and iliococcygeus form part of the pelvic diaphragm and are not related to it. The piriformis exits the pelvis via the greater sciatic foramen and is not associated with the canal in the ischiorectal fossa. Pudendal canal The pudendal canal is located along the lateral wall of the ischioanal fossa at the inferior margin of the obturator internus muscle. It extends from the lesser sciatic foramen to the posterior margin of the urogenital diaphragm. It conveys the internal pudendal vessels and nerve.

Answer 755

Mnemonic lateral hip rotators: P-GO-GO-Q (top to bottom) Piriformis Gemellus superior Obturator internus Gemellus inferior Obturator externus Quadratus femoris Pectineus adducts and medially rotates the femur. Hip joint Head of femur articulates with acetabulum of the pelvis Both covered by articular hyaline cartilage The acetabulum forms at the union of the ilium, pubis, and ischium The triradiate cartilage (Y-shaped growth plate) separates the pelvic bones The acetabulum holds the femoral head by the acetabular labrum Normal angle between femoral head and femoral shaft is 130o Ligaments Transverse ligament: joints anterior and posterior ends of the articular cartilage Head of femur ligament (ligamentum teres): acetabular notch to the fovea. Contains arterial supply to head of femur in children. Extracapsular ligaments Iliofemoral ligament: inverted Y shape. Anterior iliac spine to the trochanteric line Pubofemoral ligament: acetabulum to lesser trochanter Ischiofemoral ligament: posterior support. Ischium to greater trochanter. Blood supply Medial circumflex femoral and lateral circumflex femoral arteries (Branches of profunda femoris). Also from the inferior gluteal artery. These form an anastomosis and travel to up the femoral neck to supply the head.

Answer 756

When there are concerns that pancreatic necrosis may have become infected the usual approach is to perform an image guided FNA for culture. There is always the risk of seeding infection with such a strategy so it must be performed with care. Pancreatic necrosectomy is not usually undertaken until the presence of infection is proven. Management of Pancreatitis Management of Acute Pancreatitis in the UK Diagnosis Traditionally hyperamylasaemia has been utilised with amylase being elevated three times the normal range. However, amylase may give both false positive and negative results. Serum lipase is both more sensitive and specific than serum amylase. It also has a longer half life. Serum amylase levels do not correlate with disease severity. Differential causes of hyperamylasaemia Acute pancreatitis Pancreatic pseudocyst Mesenteric infarct Perforated viscus Acute cholecystitis Diabetic ketoacidosis Assessment of severity Glasgow, Ranson scoring systems and APACHE II Biochemical scoring e.g. using CRP Features that may predict a severe attack within 48 hours of admission to hospital Initial assessment Clinical impression of severity Body mass index >30 Pleural effusion APACHE score >8 24 hours after admission Clinical impression of severity APACHE II >8 Glasgow score of 3 or more Persisting multiple organ failure CRP>150 48 hours after admission Glasgow Score of >3 CRP >150 Persisting or progressive organ failure Table adapted from UK guidelines for management of acute pancreatitis. GUT 2005, 54 suppl III Management Nutrition There is reasonable evidence to suggest that the use of enteral nutrition does not worsen the outcome in pancreatitis Most trials to date were underpowered to demonstrate a conclusive benefit. The rationale behind feeding is that it helps to prevent bacterial translocation from the gut, thereby contributing to the development of infected pancreatic necrosis. Use of antibiotic therapy Many UK surgeons administer antibiotics to patients with acute pancreatitis. However, there is very little evidence to support this practice. A recent Cochrane review highlights the potential benefits of administering Imipenem to patients with established pancreatic necrosis in the hope of averting the progression to infection. There are concerns that the administration of antibiotics in mild attacks of pancreatitis will not affect outcome and may contribute to antibiotic resistance and increase the risks of antibiotic associated diarrhoea. Surgery Patients with acute pancreatitis due to gallstones should undergo early cholecystectomy. Patients with obstructed biliary system due to stones should undergo early ERCP. Patients with extensive necrosis where infection is suspected should usually undergo FNA for culture. Patients with infected necrosis should undergo either radiological drainage or surgical necrosectomy. The choice of procedure depends upon local expertise. References www.bsg.org.uk/pdfworddocs/pancreatic.pdf Antibiotic therapy for prophylaxis against infection of pancreatic necrosis in acute pancreatitis. Villatoro et al. Cochrane Library DOI: 10.1002/14651858.CD002941.pub3. 2010 version.

Answer 757

The tensor tympani muscle (in conjunction with stapedius) helps to mitigate the effects of loud sounds. The tensor tympani is innervated by the trigeminal nerve (the stapedius by the facial). In some people with hyperacousia, the tensor tympani muscle does not function normally. Trigeminal nerve The trigeminal nerve is the main sensory nerve of the head. In addition to its major sensory role, it also innervates the muscles of mastication. Distribution of the trigeminal nerve Sensory Scalp Face Oral cavity (and teeth) Nose and sinuses Dura mater Motor Muscles of mastication Mylohyoid Anterior belly of digastric Tensor tympani Tensor palati Autonomic connections (ganglia) Ciliary Sphenopalatine Otic Submandibular Path Originates at the pons Sensory root forms the large, crescentic trigeminal ganglion within Meckel's cave, and contains the cell bodies of incoming sensory nerve fibres. Here the 3 branches exit. The motor root cell bodies are in the pons and the motor fibres are distributed via the mandibular nerve. The motor root is not part of the trigeminal ganglion. Branches of the trigeminal nerve Ophthalmic nerve Sensory only Maxillary nerve Sensory only Mandibular nerve Sensory and motor Sensory Ophthalmic Exits skull via the superior orbital fissure Sensation of: scalp and forehead, the upper eyelid, the conjunctiva and cornea of the eye, the nose (including the tip of the nose, except alae nasi), the nasal mucosa, the frontal sinuses, and parts of the meninges (the dura and blood vessels). Maxillary nerve Exit skull via the foramen rotundum Sensation: lower eyelid and cheek, the nares and upper lip, the upper teeth and gums, the nasal mucosa, the palate and roof of the pharynx, the maxillary, ethmoid and sphenoid sinuses, and parts of the meninges. Mandibular nerve Exit skull via the foramen ovale Sensation: lower lip, the lower teeth and gums, the chin and jaw (except the angle of the jaw), parts of the external ear, and parts of the meninges. Motor Distributed via the mandibular nerve. The following muscles of mastication are innervated: Masseter Temporalis Medial pterygoid Lateral pterygoid Other muscles innervated include: Tensor veli palatini Mylohyoid Anterior belly of digastric Tensor tympani

Answer 758

The ansa cervicalis lies anterior to the carotid artery and on the carotid sheath. It may be exposed by division of the pretracheal fascia at the posterolateral aspect of the thyroid gland. The pre vertebral fascia lies more posteriorly and division of the investing layer of fascia will not expose this nerve. Ansa cervicalis Superior root Branch of C1 anterolateral to carotid sheath Inferior root Derived from C2 and C3 roots, passes posterolateral to the internal jugular vein (may lie either deep or superficial to it) Innervation Sternohyoid Sternothyroid Omohyoid The ansa cervicalis lies anterior to the carotid sheath. The nerve supply to the inferior strap muscles enters at their inferior aspect. Therefore when dividing these muscles to expose a large goitre, the muscles should be divided in their upper half.

Answer 759

The stress response to surgery is multimodal and encompasses a number of physiological responses. However, cardiac output is usually increased (sympathetic nervous system induces hypertension and tachycardia). Its also results in GI tract smooth muscle relaxation. The renin angiotensin system is activated resulting in vasoconstriction and increased angiotensin II levels. Stress response: Endocrine and metabolic changes - Surgery precipitates hormonal and metabolic changes causing the stress response. Stress response is associated with: substrate mobilization, muscle protein loss, sodium and water retention, suppression of anabolic hormone secretion, activation of the sympathetic nervous system, immunological and haematological changes. The hypothalamic-pituitary axis and the sympathetic nervous systems are activated and there is a failure of the normal feedback mechanisms of control of hormone secretion. A summary of the hormonal changes associated with the stress response: Increased Decreased No Change Growth hormone Insulin Thyroid stimulating hormone Cortisol Testosterone Luteinizing hormone Renin Oestrogen Follicle stimulating hormone Adrenocorticotrophic hormone (ACTH) Aldosterone Prolactin Antidiuretic hormone Glucagon Sympathetic nervous system Stimulates catecholamine release Causes tachycardia and hypertension Pituitary gland ACTH and growth hormone (GH) is stimulated by hypothalamic releasing factors, corticotrophin releasing factor (CRF) and somatotrophin (or growth hormone releasing factor) Perioperative increased prolactin secretion occurs by release of inhibitory control Secretion of thyroid stimulating hormone (TSH), luteinizing hormone (LH) and follicle stimulating hormone (FSH) does not change significantly ACTH stimulates cortisol production within a few minutes of the start of surgery. More ACTH is produced than needed to produce a maximum adrenocortical response. Cortisol Significant increases within 4-6 hours of surgery (>1000 nmol litre-1). The usual negative feedback mechanism fails and concentrations of ACTH and cortisol remain persistently increased. The magnitude and duration of the increase correlate with the severity of stress and the response is not abolished by the administration of corticosteroids. The metabolic effects of cortisol are enhanced: Skeletal muscle protein breakdown to provide gluconeogenic precursors and amino acids for protein synthesis in the liver Stimulation of lipolysis 'Anti-insulin effect' Mineralocorticoid effects Anti-inflammatory effects Growth hormone Increased secretion after surgery has a minor role Most important for preventing muscle protein breakdown and promote tissue repair by insulin growth factors Alpha Endorphin Increased Antidiuretic hormone An important vasopressor and enhances haemostasis Renin is released causing the conversion of angiotensinogen to angiotensin I Angiotensin II formed by ACE on angiotensin 1, which causes the secretion of aldosterone from the adrenal cortex. This increases sodium reabsorption at the distal convoluted tubule Insulin Release inhibited by stress Occurs via the inhibition of the beta cells in the pancreas by the α2-adrenergic inhibitory effects of catecholamines Insulin resistance by target cells occurs later The perioperative period is characterized by a state of functional insulin deficiency Thyroxine (T4) and tri-iodothyronine (T3) Circulating concentrations are inversely correlated with sympathetic activity and after surgery there is a reduction in thyroid hormone production, which normalises over a few days. Metabolic effect of endocrine response Carbohydrate metabolism Hyperglycaemia is a main feature of the metabolic response to surgery Due to increase in glucose production and a reduction in glucose utilization Catecholamines and cortisol promote glycogenolysis and gluconeogenesis Initial failure of insulin secretion followed by insulin resistance affects the normal responses The proportion of the hyperglycaemic response reflects the severity of surgery Hyperglycaemia impairs wound healing and increase infection rates Protein metabolism Initially there is inhibition of protein anabolism, followed later, if the stress response is severe, by enhanced catabolism The amount of protein degradation is influenced by the type of surgery and also by the nutritional status of the patient Mainly skeletal muscle protein is affected The amino acids released form acute phase proteins (fibrinogen, C reactive protein, complement proteins, a2-macroglobulin, amyloid A and ceruloplasmin) and are used for gluconeogenesis Nutritional support has little effect on preventing catabolism Lipid metabolism Increased catecholamine, cortisol and glucagon secretion, and insulin deficiency, promotes lipolysis and ketone body production. Salt and water metabolism ADH causes water retention, concentrated urine, and potassium loss and may continue for 3 to 5 days after surgery Renin causes sodium and water retention Cytokines Glycoproteins Interleukins (IL) 1 to 17, interferons, and tumour necrosis factor Synthesized by activated macrophages, fibroblasts, endothelial and glial cells in response to tissue injury from surgery or trauma IL-6 main cytokine associated with surgery. Peak 12 to 24 h after surgery and increase by the degree of tissue damage Other effects of cytokines include fever, granulocytosis, haemostasis, tissue damage limitation and promotion of healing. Modifying the response Opioids suppress hypothalamic and pituitary hormone secretion At high doses the hormonal response to pelvic and abdominal surgery is abolished. However, such doses prolong recovery and increase the need for postoperative ventilatory support Spinal anaesthesia can reduce the glucose, ACTH, cortisol, GH and epinephrine changes, although cytokine responses are unaltered Cytokine release is reduced in less invasive surgery Nutrition prevents the adverse effects of the stress response. Enteral feeding improves recovery Growth hormone and anabolic steroids may improve outcome Normothermia decreases the metabolic response References Vasiliki Manou-Stathopoulou et al. Redefining the perioperative stress response: a narrative review. Br J Anaesth. 2019 Nov;123(5):570-583. Deborah Burton, Grainne Nicholson, and George Hall Endocrine and metabolic response to surgery . Contin Educ Anaesth Crit Care Pain (2004) 4(5): 144-147 doi:10.1093/bjaceaccp/mkh040

Answer 760

The circumflex artery is generally a branch of the left coronary artery. Heart anatomy The walls of each cardiac chamber comprise: Epicardium Myocardium Endocardium Cardiac muscle is attached to the cardiac fibrous skeleton. Relations The heart and roots of the great vessels within the pericardial sac are related to the posterior aspect of the sternum, medial ends of the 3rd to 5th ribs on the left and their associated costal cartilages. The heart and pericardial sac are situated obliquely two thirds to the left and one third to the right of the median plane. The pulmonary valve lies at the level of the left third costal cartilage. The mitral valve lies at the level of the fourth costal cartilage. Coronary sinus This lies in the posterior part of the coronary groove and receives blood from the cardiac veins. The great cardiac vein lies at its left and the middle and small cardiac veins lie on its right. The smallest cardiac vein (anterior cardiac vein) drains into the right atrium directly. Aortic sinus Right coronary artery arises from the right aortic sinus, the left is derived from the left aortic sinus, which lies posteriorly. Features of the left ventricle as opposed to the right Structure Left Ventricle A-V Valve Mitral (double leaflet) Walls Twice as thick as right Trabeculae carnae Much thicker and more numerous Right coronary artery The RCA supplies: Right atrium Diaphragmatic part of the right ventricle Usually the posterior third of the interventricular septum The sino atrial node (60% cases) The atrio ventricular node (80% cases) Left coronary artery The LCA supplies: Left atrium Most of left ventricle Part of the right ventricle Anterior two thirds of the inter ventricular septum The sino atrial node (remaining 40% cases) Innervation of the heart Autonomic nerve fibres from the superficial and deep cardiac plexus. These lie anterior to the bifurcation of the trachea, posterior to the ascending aorta and superior to the bifurcation of the pulmonary trunk. The parasympathetic supply to the heart is from presynaptic fibres of the vagus nerves. Valves of the heart Mitral valve Aortic valve Pulmonary valve Tricuspid valve 2 cusps 3 cusps 3 cusps 3 cusps First heart sound Second heart sound Second heart sound First heart sound 1 anterior cusp 2 anterior cusps 2 anterior cusps 2 anterior cusps Attached to chordae tendinae No chordae No chordae Attached to chordae tendinae

Answer 761

The external urethral sphincter is innervated by branches of the pudendal nerve, therefore the root values are S2, S3, S4. Urethral anatomy Female urethra The female urethra is shorter and more acutely angulated than the male urethra. It is an extra-peritoneal structure and embedded in the endopelvic fascia. The neck of the bladder is subjected to transmitted intra-abdominal pressure and therefore deficiency in this area may result in stress urinary incontinence. Between the layers of the urogenital diaphragm the female urethra is surrounded by the external urethral sphincter, this is innervated by the pudendal nerve. It ultimately lies anterior to the vaginal orifice. Male urethra In males the urethra is much longer and is divided into four parts. Pre-prostatic urethra Extremely short and lies between the bladder and prostate gland.It has a stellate lumen and is between 1 and 1.5cm long.Innervated by sympathetic noradrenergic fibres, as this region is composed of striated muscles bundles they may contract and prevent retrograde ejaculation. Prostatic urethra This segment is wider than the membranous urethra and contains several openings for the transmission of semen (at the midpoint of the urethral crest). Membranous urethra Narrowest part of the urethra and surrounded by external sphincter. It traverses the perineal membrane 2.5cm postero-inferior to the symphysis pubis. Penile urethra Travels through the corpus spongiosum on the underside of the penis. It is the longest urethral segment.It is dilated at its origin as the infrabulbar fossa and again in the glans penis as the navicular fossa. The bulbo-urethral glands open into the spongiose section of the urethra 2.5cm below the perineal membrane. The urothelium is transitional in nature near to the bladder and becomes squamous more distally.

Answer 762

Boundaries of the deep inguinal ring: Superolaterally - transversalis fascia Inferomedially - inferior epigastric artery The deep inguinal ring is closely related to the inferior epigastric artery. The inferior epigastric artery forms part of the structure referred to as Hesselbach's triangle. Inguinal canal Location Above the inguinal ligament The inguinal canal is 4cm long The superficial ring is located anterior to the pubic tubercle The deep ring is located approximately 1.5-2cm above the half way point between the anterior superior iliac spine and the pubic tubercle Boundaries of the inguinal canal Floor External oblique aponeurosis Inguinal ligament Lacunar ligament Roof Internal oblique Transversus abdominis Anterior wall External oblique aponeurosis Posterior wall Transversalis fascia Conjoint tendon Laterally Internal ring Transversalis fascia Fibres of internal oblique Medially External ring Conjoint tendon Contents Males Spermatic cord and ilioinguinal nerve As it passes through the canal the spermatic cord has 3 coverings: External spermatic fascia from external oblique aponeurosis Cremasteric fascia Internal spermatic fascia Females Round ligament of uterus and ilioinguinal nerve

Answer 763

SIADH - drug causes: carbamazepine, sulfonylureas, SSRIs, tricyclics Lithium can cause diabetes insipidus but this is generally associated with a high sodium. Lithium only tends to cause raised antidiuretic hormone levels following a severe overdosage. syndrome of inappropriate antidiuretic hormone (SIADH): causes Malignancy especially small cell lung cancer also: pancreas, prostate Neurological stroke subarachnoid haemorrhage subdural haemorrhage meningitis/encephalitis/abscess Infections tuberculosis pneumonia Drugs sulfonylureas SSRIs, tricyclics carbamazepine vincristine cyclophosphamide Other causes positive end-expiratory pressure (PEEP) porphyrias

Answer 764

It drains directly via a very short vessel. If the sutures are not carefully tied then it may be avulsed off the IVC. An injury best managed using a Satinsky clamp and a 6/0 prolene suture. Adrenal gland anatomy Anatomy Location Superomedially to the upper pole of each kidney Relationships of the right adrenal Diaphragm-Posteriorly, Kidney-Inferiorly, Vena Cava-Medially, Hepato-renal pouch and bare area of the liver-Anteriorly Relationships of the left adrenal Crus of the diaphragm-Postero- medially, Pancreas and splenic vessels-Inferiorly, Lesser sac and stomach-Anteriorly Arterial supply Superior adrenal arteries- from inferior phrenic artery, Middle adrenal arteries - from aorta, Inferior adrenal arteries -from renal arteries Venous drainage of the right adrenal Via one central vein directly into the IVC Venous drainage of the left adrenal Via one central vein into the left renal vein

Answer 765

The posterior cruciate ligament is separated from the popliteal vessels at its origin by the oblique popliteal ligament.It is attached above to the upper margin of the intercondyloid fossa and posterior surface of the femur close to the articular margins of the condyles, and below to the posterior margin of the head of the tibia. The transverse ligament is located anteriorly. Knee joint The knee joint is a synovial joint, the largest and most complicated. It consists of two condylar joints between the femur and tibia and a sellar joint between the patella and the femur. The tibiofemoral articular surfaces are incongruent, however, this is improved by the presence of the menisci. The degree of congruence is related to the anatomical position of the knee joint and is greatest in full extension. Knee joint compartments Tibiofemoral Comprised of the patella/femur joint, lateral and medial compartments (between femur condyles and tibia) Synovial membrane and cruciate ligaments partially separate the medial and lateral compartments Patellofemoral Ligamentum patellae Actions: provides joint stability in full extension Fibrous capsule The capsule of the knee joint is a complex, composite structure with contributions from adjacent tendons. Anterior fibres The capsule does not pass proximal to the patella. It blends with the tendinous expansions of vastus medialis and lateralis Posterior fibres These fibres are vertical and run from the posterior surface of the femoral condyles to the posterior aspect of the tibial condyle Medial fibres Attach to the femoral and tibial condyles beyond their articular margins, blending with the tibial collateral ligament Lateral fibres Attach to the femur superior to popliteus, pass over its tendon to head of fibula and tibial condyle Bursae Anterior Subcutaneous prepatellar bursa; between patella and skin Deep infrapatellar bursa; between tibia and patellar ligament Subcutaneous infrapatellar bursa; between distal tibial tuberosity and skin Laterally Bursa between lateral head of gastrocnemius and joint capsule Bursa between fibular collateral ligament and tendon of biceps femoris Bursa between fibular collateral ligament and tendon of popliteus Medially Bursa between medial head of gastrocnemius and the fibrous capsule Bursa between tibial collateral ligament and tendons of sartorius, gracilis and semitendinosus Bursa between the tendon of semimembranosus and medial tibial condyle and medial head of gastrocnemius Posterior Highly variable and inconsistent Ligaments Medial collateral ligament Medial epicondyle femur to medial tibial condyle: valgus stability Lateral collateral ligament Lateral epicondyle femur to fibula head: varus stability Anterior cruciate ligament Anterior tibia to lateral intercondylar notch femur: prevents tibia sliding anteriorly Posterior cruciate ligament Posterior tibia to medial intercondylar notch femur: prevents tibia sliding posteriorly Patellar ligament Central band of the tendon of quadriceps femoris, extends from patella to tibial tuberosity Menisci Medial and lateral menisci compensate for the incongruence of the femoral and tibial condyles. Composed of fibrous tissue. Medial meniscus is attached to the tibial collateral ligament. Lateral meniscus is attached to the loose fibres at the lateral edge of the joint and is separate from the fibular collateral ligament. The lateral meniscus is crossed by the popliteus tendon. Nerve supply The knee joint is supplied by the femoral, tibial and common peroneal divisions of the sciatic and by a branch from the obturator nerve. Hip pathology pain may be referred to the knee. Blood supply Genicular branches of the femoral artery, popliteal and anterior tibial arteries all supply the knee joint.

Answer 766

Amiodarone Drugs commonly implicated in parotid gland enlargement include: Thiouracil, isoprenaline, phenylbutazone, high oestrogen dose contraceptive pills. Parotid gland clinical Benign neoplasms Up to 80% of all salivary gland tumours occur in the parotid gland and up to 80% of these are benign. There is no consistent correlation between the rate of growth and the malignant potential of the lesion. However, benign tumours should not invade structures such as the facial nerve. With the exception of Warthins tumours, they are commoner in women than men. The median age of developing a lesion is in the 5th decade of life. Benign tumour types Tumour type Features Benign pleomorphic adenoma or benign mixed tumor Most common parotid neoplasm (80%) Proliferation of epithelial and myoepithelial cells of the ducts and an increase in stromal components Slow growing, lobular, and not well encapsulated Recurrence rate of 1-5% with appropriate excision (parotidectomy) Recurrence possibly secondary to capsular disruption during surgery Malignant degeneration occurring in 2-10% of adenomas observed for long periods, with carcinoma ex-pleomorphic adenoma occurring most frequently as adenocarcinoma Warthin tumor (papillary cystadenoma lymphoma or adenolymphoma) Second most common benign parotid tumor (5%) Most common bilateral benign neoplasm of the parotid Marked male as compared to female predominance Occurs later in life (sixth and seventh decades) Presents as a lymphocytic infiltrate and cystic epithelial proliferation May represent heterotopic salivary gland epithelial tissue trapped within intraparotid lymph nodes Incidence of bilaterality and multicentricity of 10% Malignant transformation rare (almost unheard of) Monomorphic adenoma Account for less than 5% of tumours Slow growing Consist of only one morphological cell type (hence term mono) Include; basal cell adenoma, canalicular adenoma, oncocytoma, myoepitheliomas Haemangioma Should be considered in the differential of a parotid mass in a child Accounts for 90% of parotid tumours in children less than 1 year of age Hypervascular on imaging Spontaneous regression may occur and malignant transformation is almost unheard of Malignant salivary gland tumours Types of malignancy Mucoepidermoid carcinoma 30% of all parotid malignancies Usually low potential for local invasiveness and metastasis (depends mainly on grade) Adenoid cystic carcinoma Unpredictable growth pattern Tendency for perineural spread Nerve growth may display skip lesions resulting in incomplete excision Distant metastasis more common (visceral rather than nodal spread) 5 year survival 35% Mixed tumours Often a malignancy occurring in a previously benign parotid lesion Acinic cell carcinoma Intermediate grade malignancy May show perineural invasion Low potential for distant metastasis 5 year survival 80% Adenocarcinoma Develops from secretory portion of gland Risk of regional nodal and distant metastasis 5 year survival depends upon stage at presentation, may be up to 75% with small lesions with no nodal involvement Lymphoma Large rubbery lesion, may occur in association with Warthins tumours Diagnosis should be based on regional nodal biopsy rather than parotid resection Treatment is with chemotherapy (and radiotherapy) Diagnostic evaluation Plain x-rays may be used to exclude calculi Sialography may be used to delineate ductal anatomy FNAC is used in most cases Superficial parotidectomy may be either diagnostic or therapeutic depending upon the nature of the lesion Where malignancy is suspected the primary approach should be definitive resection rather than excisional biopsy CT/ MRI may be used in cases of malignancy for staging primary disease Treatment For nearly all lesions this consists of surgical resection, for benign disease this will usually consist of a superficial parotidectomy. For malignant disease a radical or extended radical parotidectomy is performed. The facial nerve is included in the resection if involved. The need for neck dissection is determined by the potential for nodal involvement. Other parotid disorders HIV infection Lymphoepithelial cysts associated with HIV occur almost exclusively in the parotid Typically presents as bilateral, multicystic, symmetrical swelling Risk of malignant transformation is low and management usually conservative Sjogren syndrome Autoimmune disorder characterised by parotid enlargement, xerostomia and keratoconjunctivitis sicca 90% of cases occur in females Second most common connective tissue disorder Bilateral, non tender enlargement of the gland is usual Histologically, the usual findings are of a lymphocytic infiltrate in acinar units and epimyoepithelial islands surrounded by lymphoid stroma Treatment is supportive There is an increased risk of subsequent lymphoma Sarcoid Parotid involvement occurs in 6% of patients with sarcoid Bilateral in most cases Gland is not tender Xerostomia may occur Management of isolated parotid disease is usually conservative

Answer 767

Non specific abdominal pain is a commonly recorded diagnosis for patients presenting with acute abdominal pain. Following careful diagnostic work up, a proportion of patients may be identified with disorders such as coeliac disease and the diagnosis of non specific abdominal pain should not be used lightly. Acute abdominal pain Acute abdominal pain is a common cause of admission to hospital. The relative proportions of conditions presenting with abdominal pain is given below: Non specific abdominal pain (35%) Appendicitis (17%) Intestinal obstruction (15%) Urological disease (6%) Gallstone disease (5%) Colonic diverticular disease (4%) Abdominal trauma (3%) Perforated peptic ulcer (3%) Pancreatitis (2%) (Data derived from Irvin T. Br. J. Surg 1989 76:1121-1125) Non specific abdominal pain should really be a diagnosis of exclusion and if care is taken in excluding organic disease the proportion of cases labeled such should decline. It should also be appreciated that a proportion of patients may have an underlying medical cause for their symptoms such as pneumonia or diabetic ketoacidosis. Key points in management Early administration of adequate analgesia (including opiates). Abdominal ultrasound is safe, non invasive and cheap and yields significantly more information than plain radiology. However, plain radiology is still the main test for suspected perforated viscus, especially out of hours. In up to 50% cases with perforated peptic ulcer, the plain x-rays may show no evidence of free air. If clinical signs suggest otherwise, then a CT scan may be a more accurate investigation, if plain films are normal. Plain film radiology usually cannot detect <1mm free air, and is 33% sensitive for detection of 1-13mm pockets of free air (Stoker et al. Radiology 2009 253: 31-46). Think of strangulated intestine when there is fever, raised white cell count, tachycardia and peritonism. In suspected large bowel obstruction a key investigation is either a water soluble contrast enema or CT scan. Where need for surgery is difficult to define and imaging is inconclusive the use of laparoscopy as a definitive diagnostic test is both safe and sensible.

Answer 768

Path Dorsal venous arch drains laterally into the cephalic vein Crosses the anatomical snuffbox and travels laterally up the arm At the antecubital fossa connected to the basilic vein by the median cubital vein Pierces deep fascia of deltopectoral groove to join axillary vein

Answer 769

A combination of ipsilateral ataxia, nystagmus, dysphagia, facial numbness, cranial nerve palsy with contralateral hemisensory loss indicates this diagnosis. Stroke: types Primary intracerebral haemorrhage (PICH, c. 10%) Presents with headache, vomiting, loss of consciousness Total anterior circulation infarcts (TACI, c. 15%) Involves middle and anterior cerebral arteries Hemiparesis/hemisensory loss Homonymous hemianopia Higher cognitive dysfunction e.g. Dysphasia Partial anterior circulation infarcts (PACI, c. 25%) Involves smaller arteries of anterior circulation e.g. upper or lower division of middle cerebral artery Higher cognitive dysfunction or two of the three TACI features Lacunar infarcts (LACI, c. 25%) Involves perforating arteries around the internal capsule, thalamus and basal ganglia Present with either isolated hemiparesis, hemisensory loss or hemiparesis with limb ataxia Posterior circulation infarcts (POCI, c. 25%) Vertebrobasilar arteries Presents with features of brainstem damage Ataxia, disorders of gaze and vision, cranial nerve lesions Lateral medullary syndrome (posterior inferior cerebellar artery) Wallenberg's syndrome Ipsilateral: ataxia, nystagmus, dysphagia, facial numbness, cranial nerve palsy Contralateral: limb sensory loss Weber's syndrome Ipsilateral III palsy Contralateral weakness -------------------------------------- Anterior cerebral artery Contralateral hemiparesis and sensory loss, lower extremity > upper Disconnection syndrome Middle cerebral artery Contralateral hemiparesis and sensory loss, upper extremity > lower Contralateral hemianopia Aphasia (Wernicke's) Gaze abnormalities Posterior cerebral artery Contralateral hemianopia with macular sparing Disconnection syndrome Lacunar Present with either isolated hemiparesis, hemisensory loss or hemiparesis with limb ataxia Lateral medulla (posterior inferior cerebellar artery) Ipsilateral: ataxia, nystagmus, dysphagia, facial numbness, cranial nerve palsy e.g. Horner's Contralateral: limb sensory loss Pontine VI nerve: horizontal gaze palsy VII nerve Contralateral hemiparesis

Answer 770

PT: Vitamin K dependent factors 2, 7, 9, 10 APTT: Factors 8, 9, 11, 12 Jaundice will impair the production of vitamin K dependent clotting factors. This is most accurately tested by measuring the prothrombin time. APTT can be affected by vitamin K deficiency (due to factor 9 deficiency), however this occurs to a lesser extent and is normally associated with severe liver disease. The bleeding time is a measure of platelet function. Abnormal coagulation Cause Factors affected Heparin Prevents activation factors 2,9,10,11 Warfarin Affects synthesis of factors 2,7,9,10 DIC Factors 1,2,5,8,11 Liver disease Factors 1,2,5,7,9,10,11 Interpretation blood clotting test results Disorder APTT PT Bleeding time Haemophilia Increased Normal Normal von Willebrand's disease Increased Normal Increased Vitamin K deficiency Increased Increased Normal

Answer 771

This is common in footballers as the football boot studs stick to the ground and high twisting force is applied to a flexed knee. Rapid joint swelling also supports the diagnosis. Knee injury Types of injury Ruptured anterior cruciate ligament Sport injury Mechanism: high twisting force applied to a bent knee Typically presents with: loud crack, pain and RAPID joint swelling (haemoarthrosis) Poor healing Management: intense physiotherapy or surgery Ruptured posterior cruciate ligament Mechanism: hyperextension injuries Tibia lies back on the femur Paradoxical anterior draw test Rupture of medial collateral ligament Mechanism: leg forced into valgus via force outside the leg Knee unstable when put into valgus position Menisceal tear Rotational sporting injuries Delayed knee swelling Joint locking (Patient may develop skills to 'unlock' the knee Recurrent episodes of pain and effusions are common, often following minor trauma Chondromalacia patellae Teenage girls, following an injury to knee e.g. Dislocation patella Typical history of pain on going downstairs or at rest Tenderness, quadriceps wasting Dislocation of the patella Most commonly occurs as a traumatic primary event, either through direct trauma or through severe contraction of quadriceps with knee stretched in valgus and external rotation Genu valgum, tibial torsion and high riding patella are risk factors Skyline x-ray views of patella are required, although displaced patella may be clinically obvious An osteochondral fracture is present in 5% The condition has a 20% recurrence rate Fractured patella 2 types: i. Direct blow to patella causing undisplaced fragments ii. Avulsion fracture Tibial plateau fracture Occur in the elderly (or following significant trauma in young) Mechanism: knee forced into valgus or varus, but the knee fractures before the ligaments rupture Varus injury affects medial plateau and if valgus injury, lateral plateau depressed fracture occurs Classified using the Schatzker system (see below) Schatzker Classification system for tibial plateau fractures Type Anatomical description Features 1 Vertical split of lateral condyle Fracture through dense bone, usually in the young. It may be virtually undisplaced, or the condylar fragment may be pushed inferiorly and tilted 2 Vertical split of the lateral condyle combined with an adjacent load bearing part of the condyle The wedge fragment (which may be of variable size), is displaced laterally; the joint is widened. Untreated, a valgus deformity may develop 3 Depression of the articular surface with intact condylar rim The split does not extend to the edge of the plateau. Depressed fragments may be firmly embedded in subchondral bone, the joint is stable 4 Fragment of the medial tibial condyle Two injuries are seen in this category; (1) a depressed fracture of osteoporotic bone in the elderly. (2) a high energy fracture resulting in a condylar split that runs from the intercondylar eminence to the medial cortex. Associated ligamentous injury may be severe 5 Fracture of both condyles Both condyles fractured but the column of the metaphysis remains in continuity with the tibial shaft 6 Combined condylar and subcondylar fractures High energy fracture with marked comminution

Answer 772

Because it is excreted by renal tubular cells a MAG 3 renogram provides excellent imaging of renal function and is often used in investigating failing transplants. Functional renal imaging DMSA scan Dimercaptosuccinic acid (DMSA) scintigraphy DMSA localises to the renal cortex with little accumulation in the renal papilla and medulla. It is useful for the identification of cortical defects and ectopic or aberrant kidneys. It does not provide useful information on the ureter of collecting system. Diethylene-triamine-penta-acetic acid (DTPA) This is primarily a glomerular filtration agent. It is most useful for the assessment of renal function. Because it is filtered at the level of the glomerulus it provides useful information about the GFR. Image quality may be degraded in patients with chronic renal impairment and derangement of GFR. MAG 3 renogram Mercaptoacetyle triglycine is an is extensively protein bound and is primarily secreted by tubular cells rather than filtered at the glomerulus. This makes it the agent of choice for imaging the kidneys of patients with existing renal impairment (where GFR is impaired). Micturating cystourethrogram (MCUG scan) This scan provides information relating to bladder reflux and is obtained by filling the bladder with contrast media (via a catheter) and asking the child to void. Images are taken during this phase and the degree of reflux can be calculated Intra venous urography This examination is conducted by the administration of intravenous iodinated contrast media. The agent is filtered by the kidneys and excreted and may provide evidence of renal stones or other structural lesions. A rough approximation of renal function may be obtained using the technique. But it is not primarily a technique to be used for this purpose. With the advent of widespread non contrast CT scan protocols for the detection of urinary tract calculi it is now rarely used. PET/CT This may be used to evaluate structurally indeterminate lesions in the staging of malignancy. References Davis A et al. Investigating urinary tract infections in children. BMJ 2013 (346):35-37.

Answer 773

When a patient requires a significant intervention, time permits and the patient lacks capacity to decide for themselves The Mental Capacity Act (MCA) requires doctors to involve an independent mental capacity advocate (IMCA) for serious medical treatment decisions when: a best interests decision is required because the doctor has assessed the person as not having the capacity to make the decision themselves the person does not have family or friends with whom it is appropriate to consult about the decision. Serious medical treatment is defined in the Mental Capacity Act 2005 (Independent Mental Capacity Advocates) (General) Regulations 2006 as treatment which involves providing, withdrawing or withholding treatment in circumstances where one or more of the following apply: in a case where a single treatment is being proposed, there is a fine balance between its benefits to the patient and the burdens and risks it is likely to entail for them in a case where there is a choice of treatments, a decision as to which one to use is finely balanced what is proposed would be likely to involve serious consequences for the patient. The MCA Code of Practice says that serious consequences may include treatment options which: cause serious and prolonged pain, distress or side effects have potentially major consequences for the patient (for example, major surgery or stopping life-sustaining treatment) have a serious impact on the patients future life choices. Consent There are 3 types of consent: 1. Informed 2. Expressed 3. Implied Consent forms used in UK NHS Consent Form 1 For competent adults who are able to consent for themselves where consciousness may be impaired (e.g. GA) Consent Form 2 For an adult consenting on behalf of a child where consciousness is impaired Consent Form 3 For an adult or child where consciousness is not impaired Consent Form 4 For adults who lack capacity to provide informed consent Capacity Key points include: 1. Understand and retain information 2. Patient believes the information to be true 3. Patient is able to weigh the information to make a decision All patients must be assumed to have capacity Consent in minors Young children and older children who are not Gillick competent cannot consent for themselves. In British law the patients biological mother can always provide consent. The child's father can consent if the parents are married (and the father is the biological father), or if the father is named on the birth certificate (irrespective of marital status). If parents are not married and the father is not named on the birth certificate then the father cannot consent.

Answer 774

The decision as to how best to manage patients with re-bleeding is difficult. Whilst it is tempting to offer repeat endoscopy, this intervention is best used on those with small ulcers. Large posteriorly sited duodenal ulcers are at high risk for re-bleeding and the timeframe of this event suggests that primary endoscopic haemostasis was inadequate. Surgery thus represents the safest way forward. Upper gastrointestinal bleeding Patients may present with the following: Haematemesis and/ or malaena Epigastric discomfort Sudden collapse The extent to which these will occur will depend upon the source. Mortality is higher in patients presenting with haematemesis than malaena alone. Oesophageal bleeding Cause Presenting features Oesophagitis Small volume of fresh blood, often streaking vomit. Malaena rare. Often ceases spontaneously. Usually history of antecedent GORD type symptoms. Cancer Usually small volume of blood, except as pre terminal event with erosion of major vessels. Often associated symptoms of dysphagia and constitutional symptoms such as weight loss. May be recurrent until malignancy managed. Mallory Weiss Tear Typically brisk small to moderate volume of bright red blood following bout of repeated vomiting. Malaena rare. Usually ceases spontaneously. Varices Usually large volume of fresh blood. Swallowed blood may cause malaena. Often associated with haemodynamic compromise. May stop spontaneously but re-bleeds are common until appropriately managed. Gastric Bleeding Cause Presenting features Gastric cancer May be frank haematemesis or altered blood mixed with vomit. Usually prodromal features of dyspepsia and may have constitutional symptoms. Amount of bleeding variable but erosion of major vessel may produce considerable haemorrhage. Dieulafoy Lesion Often no prodromal features prior to haematemesis and malaena, but this arteriovenous malformation may produce quite considerable haemorrhage and may be difficult to detect endoscopically. Diffuse erosive gastritis Usually haematemesis and epigastric discomfort. Usually there is an underlying cause such as recent NSAID usage. Large volume haemorrhage may occur with considerable haemodynamic compromise. Gastric ulcer Small low volume bleeds more common so would tend to present as iron deficiency anaemia. Erosion into a significant vessel may produce considerable haemorrhage and haematemesis. Duodenum Most common cause of major haemorrhage is a posteriorly sited duodenal ulcer. However, ulcers at any site in the duodenum may present with haematemesis, malaena and epigastric discomfort. The pain of duodenal ulcer is slightly different to that of gastric ulcers and often occurs several hours after eating. Peri ampullary tumours may bleed but these are rare. In patients with previous abdominal aortic aneurysm surgery aorto-enteric fistulation remains a rare but important cause of major haemorrhage associated with high mortality. Management Admission to hospital careful monitoring, cross match blood, check FBC, LFTs, U+E and Clotting (as a minimum) Patients with on-going bleeding and haemodynamic instability are likely to require O negative blood pending cross matched blood Early control of airway is vital (e.g. Drowsy patient with liver failure) Patients with suspected varices should receive terlipressin prior to endoscopy Ideally all patients admitted with upper gastrointestinal haemorrhage should undergo Upper GI endoscopy within 24 hours of admission. In those who are unstable this should occur immediately after resuscitation or in tandem with it. The endoscopy department is a potentially dangerous place for unstable patients and it may be safer to perform the endoscopy in theatre with an anaesthetist present. Varices should be banded or subjected to sclerotherapy. If this is not possible owing to active bleeding then a Sengstaken- Blakemore tube (or Minnesota tube) should be inserted. This should be done with care; gastric balloon should be inflated first and oesophageal balloon second. Remember the balloon will need deflating after 12 hours (ideally sooner) to prevent necrosis. Portal pressure should be lowered by combination of medical therapy +/- TIPSS. Patients with erosive oesophagitis / gastritis should receive a proton pump inhibitor. Mallory Weiss tears will typically resolve spontaneously Identifiable bleeding points should receive combination therapy of injection of adrenaline and either a thermal or mechanical treatment. All who have received intervention should receive a continuous infusion of a proton pump inhibitor (IV omeprazole for 72 hours) to reduce the re-bleeding rate. Patients with diffuse erosive gastritis who cannot be managed endoscopically and continue to bleed may require gastrectomy Bleeding ulcers that cannot be controlled endoscopically may require laparotomy and ulcer underruning Indications for surgery Patients > 60 years Continued bleeding despite endoscopic intervention Recurrent bleeding Known cardiovascular disease with poor response to hypotension Surgery Duodenal ulcer Laparotomy, duodenotomy and under running of the ulcer. If bleeding is brisk then the ulcer is almost always posteriorly sited and will have invaded the gastroduodenal artery. Large bites using 0 Vicryl are taken above and below the ulcer base to occlude the vessel. The duodenotomy should be longitudinal but closed transversely to avoid stenosis. For gastric ulcer Under-running of the bleeding site Partial gastrectomy-antral ulcer Partial gastrectomy or under running the ulcer- lesser curve ulcer (involving left gastric artery) Total gastrectomy if bleeding persists Summary of Acute Upper GI bleeding recommendations: The need for admission and timing of endoscopic intervention may be predicted by using the Blatchford score. This considers a patients Hb, serum urea, pulse rate and blood pressure. Those patients with a score of 0 are low risk, all others are considered high risk and require admission and endoscopy. The requirement for pre endoscopic proton pump inhibition is contentious. In the UK the National Institute of Clinical Excellence guidelines suggest the pre endoscopic PPI therapy is unnecessary. Whilst it is accepted that such treatment has no impact on mortality or morbidity a Cochrane review of this practice in 2007 did suggest that it reduced the stigmata of recent haemorrhage at endoscopy. As a result many will still administer PPI to patients prior to endoscopic intervention. Following endoscopy it is important to calculate the Rockall score for patients to determine their risk of rebleeding and mortality. A score of 3 or less is associated with a rebleeding rate of 4% and a very low risk of mortality and identifies a group of patients suitable for early discharge. References 1. http://www.sign.ac.uk/guidelines/fulltext/105/index.html 2. Joint Advisory Group on Endoscopy (JAG) Guidelines - http://www.thejag.org.uk 3. NICE Guideline: Management of acute upper GI bleeding. July 2012.

Answer 775

This is a typical scenario for medullary carcinoma in which a phaeochromocytoma may also be present. It may be inherited in an autosomal dominant fashion and affected family members may be offered prophylactic thyroidectomy. Thyroid disease Patients may present with a number of different manifestations of thyroid disease. They can be broadly sub classified according to whether they are euthyroid or have clinical signs of thyroid dysfunction. In addition it needs to be established whether they have a mass or not. Assessment History Examination including USS If a nodule is identified then it should be sampled ideally via an image guided fine needle aspiration Radionucleotide scanning is of limited use Thyroid Tumours Papillary carcinoma Follicular carcinoma Anaplastic carcinoma Medullary carcinoma Lymphoma's Multinodular goitre One of the most common reasons for presentation Provided the patient is euthyroid and asymptomatic and no discrete nodules are seen, they can be reassured. In those with compressive symptoms surgery is required and the best operation is a total thyroidectomy. Sub total resections were practised in the past and simply result in recurrent disease that requires a difficult revisional resection. Endocrine dysfunction In general these patients are managed by physicians initially. Surgery may be offered alongside radio iodine for patients with Graves disease that fails with medical management or in patients who would prefer not to be irradiated (e.g. pregnant women). Patients with hypothyroidism do not generally get offered a thyroidectomy. Sometimes people inadvertently get offered resections during the early phase of Hashimotos thyroiditis, however, with time the toxic phase passes and patients can simply be managed with thyroxine. Complications following surgery Anatomical such as recurrent laryngeal nerve damage. Bleeding. Owing to the confined space haematoma's may rapidly lead to respiratory compromise owing to laryngeal oedema. Damage to the parathyroid glands resulting in hypocalcaemia. Further sources of information 1. http://www.acb.org.uk/docs/TFTguidelinefinal.pdf- Association of Clinical Biochemistry guidelines for thyroid function tests. 2. British association of endocrine surgeons website- http://www.baets.org.uk

Answer 776

Many conditions may result in overactivity of the spleen. It is not seen in coeliac disease. Feltys syndrome occurs in association with rheumatoid disease. Disorders affecting the spleen One of the commonest conditions to affect the spleen is traumatic rupture and this is addressed elsewhere. Splenomegaly Enlargement of the spleen can commonly accompany a variety of haematological disorders. Of these, chronic conditions such as haemolytic anaemia and chronic leukaemia are often associated with splenomegaly. More acute haematological conditions tend not to cause massive splenic enlargement. Infections with parasites (such as malaria) and viruses such as Epstein Barr virus can cause splenomegaly and this one condition that is associated with sudden spontaneous splenic rupture. Portal hypertension can result in splenomegaly and the finding of an enlarged spleen on abdominal examination should prompt a search for the other stigmata of chronic liver disease. Splenic atrophy This typically occurs as a result of conditions that impair the blood flow to the spleen. Division of some of the major vessels can cause shrinkage of the spleen and this is commonly seen when splenic artery aneurysms are coiled for example.

Answer 777

Hypotension Cushings triad Widening of the pulse pressure Respiratory changes Bradycardia Due to raised ICP systemic hypertension is usually seen. Compression of the respiratory centre will typically result in Cheyne Stokes style respiration. Coning The cranial vault is a confined cavity apart from infants with a non fused fontanelle. Rises in ICP may be accommodated by shifts of CSF. Once the CSF shifting has reached its capacity ICP will start to rise briskly. The brain autoregulates its blood supply, as ICP rises the systemic circulation will display changes to try and meet the perfusion needs of the brain. Usually this will involve hypertension. As ICP rises further, the brain will be compressed, cranial nerve palsies may be seen and compression of essential centres in the brain stem will occur. When the cardiac centre is involved bradycardia will often develop.

Answer 778

Mucinous carcinomas comprise 2-3% of all breast cancers. They are one of the special type of carcinomas. These have a better prognosis than is associated with tumours of Non Special Type (NST) and axillary nodal disease is rare in this group. Breast cancer - Commoner in the older age group Invasive ductal carcinomas are the most common type. Some may arise as a result of ductal carcinoma in situ (DCIS). There are associated carcinomas of special type e.g. Tubular that may carry better prognosis. The pathological assessment involves assessment of the tumour and lymph nodes, sentinel lymph node biopsy is often used to minimise the morbidity of an axillary dissection. Treatment, typically this is either wide local excision or mastectomy. There are many sub types of both of these that fall outside of the MRCS. Some key rules to bear in mind. Whatever operation is contemplated the final cosmetic outcome does have a bearing. A woman with small breasts and a large tumour will tend to fare better with mastectomy, even if clear pathological and clinical margins can be obtained. Conversely a women with larger breasts may be able to undergo breast conserving surgery even with a relatively large primary lesion (NB tumours >4cm used to attract recommendation for mastectomy). For screen detected and impalpable tumour image guidance will be necessary. Reconstruction is always an option following any resectional procedure. However, its exact type must be tailored to age and co-morbidities of the patient. The main operations in common use include latissimus dorsi myocutaneous flap and sub pectoral implants. Women wishing to avoid a prosthesis may be offered TRAM or DIEP flaps. Surgical options Mastectomy vs Wide local excision Mastectomy Wide Local Excision Multifocal tumour Solitary lesion Central tumour Peripheral tumour Large lesion in small breast Small lesion in large breast DCIS >4cm DCIS <4cm Patient Choice Patient choice Central lesions may be managed using breast conserving surgery where an acceptable cosmetic result may be obtained, this is rarely the case in small breasts Whatever surgical option is chosen the aim should be to have a local recurrence rate of 5% or less at 5 years [1]. Nottingham Prognostic Index The Nottingham Prognostic Index can be used to give an indication of survival. In this system the tumour size is weighted less heavily than other major prognostic parameters. Calculation of NPI Tumour Size x 0.2 + Lymph node score(From table below)+Grade score(From table below). Score Lymph nodes involved Grade 1 0 1 2 1-3 2 3 >3 3 Prognosis Score Percentage 5 year survival 2.0 to 2.4 93% 2.5 to 3.4 85% 3.5 to 5.4 70% >5.4 50% This data was originally published in 1992. It should be emphasised that other factors such as vascular invasion and receptor status also impact on survival and are not included in this data and account for varying prognoses often cited in the literature. References For guidance on how breast cancer is managed in the United Kingdom visit the Association of Breast Surgery website (www.https://associationofbreastsurgery.org.uk/).

Answer 779

A Lower infusion volumes are now administered to burn patients to minimize the potential harm caused by excessive fluid administration Fluid resuscitation burns Indication: >15% total body area burns in adults (>10% children) The main aim of resuscitation is to prevent the burn deepening Most fluid is lost 24 hours after injury First 8-12 hour fluid shifts are from intravascular to interstitial fluid compartments Therefore circulatory volume can be compromised. However fluid resuscitation causes more fluid into the interstitial compartment especially colloid (therefore avoided in first 8-24 hours) Protein loss occurs There are concerns that use of the traditional Parkland formula resulted in the administration of excessive quantities of intravenous fluids in patients with burns. The current consensus guidelines state that fluid resuscitation should begin at 2 ml of lactated Ringers x patients body weight in kg x % TBSA for second- and third-degree burns. The calculated fluid volume is initiated in the following manner: one-half of the total fluid is provided in the first 8 hours after the burn injury (for example, a 100-kg man with 80% TBSA burns requires 2 × 80 × 100 = 16,000 mL in 24 hours). One-half of that volume (8,000 mL) should be provided in the first 8 hours, so the patient should be started at a rate of 1000 mL/hr. The remaining one-half of the total fluid is administered during the subsequent 16 hours. The efficacy of fluid replacement is determined in the main by monitoring urine output. For adults this is in the region of 0.5ml/kg/hr and for children less than 30Kg it is 1ml/kg/hr. Fluid resuscitation according to burn type Type of burn Age or weight Fluid rate Urine output Flames or scalding Adults and children over 14 years 2 ml Hartmanns x kg x % TBSA 0.3-0.5ml/kg/hr OR 30-50ml per hour Flames or scalding Children less than 14 years 3 ml Hartmanns x kg x % TBSA 1ml/kg/hr Flames or scalds Children less than 30Kg and infants 3 ml Hartmanns x kg x % TBSA. Plus a sugar-containing solution at maintenance rate 1ml/kg/hr Electrical injury All ages 4 ml Hartmanns x kg x % TBSA until urine clears 1-1.5 ml/kg/hr until urine clears Fluid resuscitation in electrical burn patients is different because they have far greater soft tissue involvement in muscle compartments and associated muscle death that can result in myoglobinuria. After 24 hours Maintenance crystalloid (usually dextrose-saline) is continued at a rate of 1.5 ml x(burn area)x(body weight) Colloids are rarely used (e.g. albumin) Antioxidants, such as vitamin C, can be used to minimize oxidant-mediated contributions to the inflammatory cascade in burns High tension electrical injuries and inhalation injuries require more fluid Monitor: packed cell volume, plasma sodium, base excess, and lactate Reference ATLS Manual 10th Edition.

Answer 780

Medullary breast cancer is a breast cancer of special type. Histologically, it is characterised by a marked lymphocytic infiltrate. Many of the breast cancers of special type (which comprise less than 5% of all breast cancers) have a very good prognosis. These special type cancers include; medullary, tubular, mucinous, adenoid cystic, Breast cancer - Commoner in the older age group Invasive ductal carcinomas are the most common type. Some may arise as a result of ductal carcinoma in situ (DCIS). There are associated carcinomas of special type e.g. Tubular that may carry better prognosis. The pathological assessment involves assessment of the tumour and lymph nodes, sentinel lymph node biopsy is often used to minimise the morbidity of an axillary dissection. Treatment, typically this is either wide local excision or mastectomy. There are many sub types of both of these that fall outside of the MRCS. Some key rules to bear in mind. Whatever operation is contemplated the final cosmetic outcome does have a bearing. A woman with small breasts and a large tumour will tend to fare better with mastectomy, even if clear pathological and clinical margins can be obtained. Conversely a women with larger breasts may be able to undergo breast conserving surgery even with a relatively large primary lesion (NB tumours >4cm used to attract recommendation for mastectomy). For screen detected and impalpable tumour image guidance will be necessary. Reconstruction is always an option following any resectional procedure. However, its exact type must be tailored to age and co-morbidities of the patient. The main operations in common use include latissimus dorsi myocutaneous flap and sub pectoral implants. Women wishing to avoid a prosthesis may be offered TRAM or DIEP flaps. Surgical options Mastectomy vs Wide local excision Mastectomy Wide Local Excision Multifocal tumour Solitary lesion Central tumour Peripheral tumour Large lesion in small breast Small lesion in large breast DCIS >4cm DCIS <4cm Patient Choice Patient choice Central lesions may be managed using breast conserving surgery where an acceptable cosmetic result may be obtained, this is rarely the case in small breasts A compelling indication for mastectomy, a larger tumour that would be unsuitable for breast conserving surgery Whatever surgical option is chosen the aim should be to have a local recurrence rate of 5% or less at 5 years [1]. Nottingham Prognostic Index The Nottingham Prognostic Index can be used to give an indication of survival. In this system the tumour size is weighted less heavily than other major prognostic parameters. Calculation of NPI Tumour Size x 0.2 + Lymph node score(From table below)+Grade score(From table below). Score Lymph nodes involved Grade 1 0 1 2 1-3 2 3 >3 3 Prognosis Score Percentage 5 year survival 2.0 to 2.4 93% 2.5 to 3.4 85% 3.5 to 5.4 70% >5.4 50% This data was originally published in 1992. It should be emphasised that other factors such as vascular invasion and receptor status also impact on survival and are not included in this data and account for varying prognoses often cited in the literature. References For guidance on how breast cancer is managed in the United Kingdom visit the Association of Breast Surgery website (www.https://associationofbreastsurgery.org.uk/).

Answer 781

Mnemonic for branches of the cerebral portion of the internal carotid artery 'Only Press Carotid Arteries Momentarily' Only = Opthalmic Press = Posterior communicating Carotid = Choroidal Arteries = Anterior cerebral Momentarily = Middle cerebral Internal carotid artery The internal carotid artery is formed from the common carotid opposite the upper border of the thyroid cartilage. It extends superiorly to enter the skull via the carotid canal. From the carotid canal it then passes through the cavernous sinus, above which it divides into the anterior and middle cerebral arteries. Relations in the neck Posterior Longus capitis Pre-vertebral fascia Sympathetic chain Superior laryngeal nerve Medially External carotid (near origin) Wall of pharynx Ascending pharyngeal artery Laterally Internal jugular vein (moves posteriorly at entrance to skull) Vagus nerve (most posterolaterally) Anteriorly Sternocleidomastoid Lingual and facial veins Hypoglossal nerve Relations in the carotid canal Internal carotid plexus Cochlea and middle ear cavity Trigeminal ganglion (superiorly) Leaves canal lies above the foramen lacerum Path and relations in the cranial cavity The artery bends sharply forwards in the cavernous sinus, the aducens nerve lies close to its inferolateral aspect. The oculomotor, trochlear, opthalmic and, usually, the maxillary nerves lie in the lateral wall of the sinus. Near the superior orbital fissure it turns posteriorly and passes postero-medially to pierce the roof of the cavernous sinus inferior to the optic nerve. It then passes between the optic and oculomotor nerves to terminate below the anterior perforated substance by dividing into the anterior and middle cerebral arteries. Branches Anterior and middle cerebral artery Ophthalmic artery Posterior communicating artery Anterior choroid artery Meningeal arteries Hypophyseal arteries

Answer 782

Stroke volumes range from 55-100ml. Stroke volume-Cardiac physiology The stroke volume equates to the volume of blood ejected from the ventricle during each cycle of cardiac contraction. The volumes for both ventricles are typically equal and equate roughly to 70ml for a 70Kg man. It is calculated by subtracting the end systolic volume from the end diastolic volume. Factors affecting stroke volume Cardiac size Contractility Preload Afterload

Answer 783

Structures passing through the lesser and greater sciatic foramina (medial to lateral): PIN Pudendal nerve Internal pudendal artery Nerve to obturator internus The pudendal nerve originates from the ventral rami of the second, third, and fourth sacral nerves (S2, S3, S4). It passes between the piriformis and coccygeus muscles and exits the pelvis through the the greater sciatic foramen. It crosses the spine of the ischium and reenters the pelvis through the lesser sciatic foramen. It passes through the pudendal canal. The pudendal nerve gives off the inferior rectal nerves. It terminates into 2 branches: perineal nerve, and the dorsal nerve of the penis or the dorsal nerve of the clitoris.

Answer 784

This is a description of Froment's sign, which tests for ulnar nerve palsy. It mainly tests for the function of adductor pollicis. This is supplied by the deep branch of the ulnar nerve. Remember the anterior interosseous branch (of the median nerve), which innervates the flexor pollicis longus (hence causing flexion of the thumb IP joint), branches off more proximally to the wrist. Ulnar nerve Origin C8, T1 Supplies (no muscles in the upper arm) Flexor carpi ulnaris Flexor digitorum profundus Flexor digiti minimi Abductor digiti minimi Opponens digiti minimi Adductor pollicis Interossei muscle Third and fourth lumbricals Palmaris brevis Path Posteromedial aspect of upper arm to flexor compartment of forearm, then along the ulnar. Passes beneath the flexor carpi ulnaris muscle, then superficially over the flexor retinaculum into the palm of the hand. Branches Branch Supplies Muscular branch Flexor carpi ulnaris Medial half of the flexor digitorum profundus Palmar cutaneous branch (Arises near the middle of the forearm) Skin on the medial part of the palm Dorsal cutaneous branch Dorsal surface of the medial part of the hand Superficial branch Cutaneous fibres to the anterior surfaces of the medial one and one-half digits Deep branch Hypothenar muscles All the interosseous muscles Third and fourth lumbricals Adductor pollicis Medial head of the flexor pollicis brevis Effects of injury Damage at the wrist Wasting and paralysis of intrinsic hand muscles (claw hand) Wasting and paralysis of hypothenar muscles Loss of sensation medial 1 and half fingers Damage at the elbow Radial deviation of the wrist Clawing less in 4th and 5th digits

Answer 785

Although not specific CA 19-9 in the context of this history is highly suggestive of pancreatic cancer over the other scenarios. Pancreatic cancer - Adenocarcinoma Risk factors: Smoking, diabetes, adenoma, familial adenomatous polyposis Mainly occur in the head of the pancreas (70%) Spread locally and metastasizes to the liver Carcinoma of the pancreas should be differentiated from other periampullary tumours with better prognosis Clinical features Weight loss Painless jaundice Epigastric discomfort (pain usually due to invasion of the coeliac plexus is a late feature) Pancreatitis Trousseau's sign: migratory superficial thrombophlebitis Investigations USS: May miss small lesions CT Scanning (pancreatic protocol). If unresectable on CT then no further staging needed PET/CT for those with operable disease on CT alone ERCP/ MRI for bile duct assessment Staging laparoscopy to exclude peritoneal disease Management Head of pancreas: Whipple's resection (SE dumping and ulcers). Newer techniques include pylorus preservation and SMA/ SMV resection Carcinoma body and tail: poor prognosis, distal pancreatectomy, if operable Usually adjuvent chemotherapy for resectable disease ERCP and stent for jaundice and palliation Surgical bypass may be needed for duodenal obstruction

Answer 786

Adrenal rests are a very common finding in term neonates (50%) and most regress so that by adulthood the population incidence is 1%. The adrenal glands and gonads both develop from the urogenital ridge. In early embryogenesis, the adrenal cortical tissue can migrate with the descending gonads. Adrenal gland embryology First detected at 6 weeks' gestation, the adrenal cortex is derived from the mesoderm of the posterior abdominal wall. Steroid secretion from the fetal cortex begins shortly thereafter. Adult-type zona glomerulosa and fasciculata are detected in fetal life but make up only a small proportion of the gland, and the zona reticularis is not present at all. The fetal cortex predominates throughout fetal life. The adrenal medulla is of ectodermal origin, arising from neural crest cells that migrate to the medial aspect of the developing cortex. The fetal adrenal gland is relatively large. At 4 months' gestation, it is 4 times the size of the kidney; however, at birth, it is a third of the size of the kidney. This occurs because of the rapid regression of the fetal cortex at birth. It disappears almost completely by age 1 year; by age 4-5 years, the permanent adult-type adrenal cortex has fully developed. Anatomic anomalies of the adrenal gland may occur. Because the development of the adrenals is closely associated with that of the kidneys, agenesis of an adrenal gland is usually associated with ipsilateral agenesis of the kidney, and fused adrenal glands (whereby the 2 glands join across the midline posterior to the aorta) are also associated with a fused kidney. Adrenal hypoplasia occurs in the following 2 forms: (1) hypoplasia or absence of the fetal cortex with a poorly formed medulla and (2) disorganized fetal cortex and medulla with no permanent cortex present. Adrenal heterotopia describes a normal adrenal gland in an abnormal location, such as within the renal or hepatic capsules. Accessory adrenal tissue (adrenal rests), which is usually comprised only of cortex but seen combined with medulla in some cases, is most commonly located in the broad ligament or spermatic cord but can be found anywhere within the abdomen. Even intracranial adrenal rests have been reported.

Answer 787

Colonic resections with an anastomosis below the peritoneal reflection may have an anastomotic leak rate (both clinical and radiological) of up to 15%. Therefore most surgeons will defunction such an anastomosis to reduce the clinical severity of an anastomotic leak. A loop ileostomy will achieve this end point and is relatively easy to reverse. Loop colostomy is less popular in this setting as reversal can compromise the blood supply to the anastomosis. Abdominal stomas Stomas may be sited during a range of abdominal procedures and involve bringing the lumen or visceral contents onto the skin. In most cases this applies to the bowel. However, other organs or their contents may be diverted in case of need. With bowel stomas the type method of construction and to a lesser extent the site will be determined by the contents of the bowel. In practice, small bowel stomas should be spouted so that their irritant contents are not in contact with the skin. Colonic stomas do not need to be spouted as their contents are less irritant. In the ideal situation the site of the stoma should be marked with the patient prior to surgery. Stoma siting is important as it will ultimately influence the ability of the patient to manage their stoma and also reduce the risk of leakage. Leakage of stoma contents and subsequent maceration of the surrounding skin can rapidly progress into a spiraling loss of control of stoma contents. Types of stomas Name of stoma Use Common sites Gastrostomy Gastric decompression or fixation Feeding Epigastrium Loop jejunostomy Seldom used as very high output May be used following emergency laparotomy with planned early closure Any location according to need Percutaneous jejunostomy Usually performed for feeding purposes and site in the proximal bowel Usually left upper quadrant Loop ileostomy Defunctioning of colon e.g. following rectal cancer surgery Does not decompress colon (if ileocaecal valve competent) Usually right iliac fossa End ileostomy Usually following complete excision of colon or where ileo-colic anastomosis is not planned May be used to defunction colon, but reversal is more difficult Usually right iliac fossa End colostomy Where a colon is diverted or resected and anastomosis is not primarily achievable or desirable Either left or right iliac fossa Loop colostomy To defunction a distal segment of colon Since both lumens are present the distal lumen acts as a vent May be located in any region of the abdomen, depending upon colonic segment used Caecostomy Stoma of last resort where loop colostomy is not possible Right iliac fossa Mucous fistula To decompress a distal segment of bowel following colonic division or resection Where closure of a distal resection margin is not safe or achievable May be located in any region of the abdomen according to clinical need

Answer 788

Prednisolone and it's metabolites can chemically mimic cortisol in radio-immunoassay techniques of laboratory analysis. Dexamethasone can be given as glucorticoid replacement during testing for addisons or adrenal insufficiency as it does not interfere with cortisol levels. For example, if you have a patient with polymyalgia rheumatica and they are on long term prednisolone, you can replace the prednisolone with dexamethasone to undertake a short synacthen test. Cortisol Glucocorticoid Released by zona fasiculata of the adrenal gland 90% protein bound; 10% active Circadian rhythm: High in the mornings Negative feedback via ACTH Actions Glycogenolysis Gluconeogenesis Protein catabolism Lipolysis Stress response Anti-inflammatory Decrease protein in bones Increase gastric acid Increases neutrophils/platelets/red blood cells Inhibits fibroblastic activity

Answer 789

Many of these nerves are at risk of injury during carotid surgery. However, only damage to the vagus would account for a hoarse voice. Vagus nerve The vagus nerve has mixed functions and supplies the structures from the fourth and sixth pharyngeal arches. It also supplies the fore and midgut sections of the embryonic gut tube. It carries afferent fibres from these areas (viz; pharynx, larynx, oesophagus, stomach, lungs, heart and great vessels). The efferent fibres of the vagus are of two main types. The first are preganglionic parasympathetic fibres distributed to the parasympathetic ganglia that innervate smooth muscle of the innervated organs (such as gut). The second type of efferent fibres have direct skeletal muscle innervation, these are largely to the muscles of the larynx and pharynx. Origin and course The vagus arises from the lateral surface of the medulla oblongata by a series of rootlets. It is related to the glossopharyngeal nerve cranially and the accessory nerve caudally. It exits through the jugular foramen and is contained within its own dural sheath alongside the accessory nerve. In the neck it descends vertically in the carotid sheath where it is closely related to the internal and common carotid arteries. It leaves the neck and enters the mediastinum. On the right it passes anterior to the first part of the subclavian artery, on the left it lies in the interval between the common carotid and subclavian arteries. In the mediastinum both nerves pass postero-inferiorly and reach the posterior surface of the corresponding lung root. These then branch into both lungs. At the inferior end of the mediastinum these plexuses reunite to form the formal vagal trunks that pass through the oesophageal hiatus and into the abdomen. The anterior and posterior vagal trunks are formal nerve fibres these then splay out once again sending fibres over the stomach and posteriorly to the coeliac plexus. Branches pass to the liver, spleen and kidney. Communications and branches Communication Details Superior ganglion Located in jugular foramen Communicates with the superior cervical sympathetic ganglion, accessory nerve Two branches; meningeal and auricular (the latter may give rise to vagal stimulation following instrumentation of the external auditory meatus) Inferior ganglion Communicates with the superior cervical sympathetic ganglion, hypoglossal nerve and loop between first and second cervical ventral rami Two branches; pharyngeal (supplies pharyngeal muscles) and superior laryngeal nerve (inferomedially- deep to both carotid arteries) Branches in the neck Branch Detail Superior and inferior cervical cardiac branches Arise at various points and descend into thorax On the right these pass posterior to the subclavian artery On the left the superior branch passes between the arch of the aorta and the trachea to connect with the deep cardiac plexus. The inferior branch descends with the vagus itself. Right recurrent laryngeal nerve Arises from vagus anterior to the first part of the subclavian artery, hooks under it, and ascends superomedially. It passes close to the common carotid and finally the inferior thyroid artery to insert into the larynx Branches in the thorax Branch Details Left recurrent laryngeal nerve Arises from the vagus on the aortic arch. It hooks around the inferior surface of the arch, posterior to the ligamentum arteriosum and passes upwards through the superior mediastinum and lower part of the neck. It lies in the groove between oesophagus and trachea (supplies both). It passes with the inferior thyroid artery and inserts into the larynx. Thoracic and cardiac branches There are extensive branches to both the heart and lung roots. These pass throughout both these viscera. The fibres reunite distally prior to passing into the abdomen. Abdominal branches After entry into the abdominal cavity the nerves branch extensively. In previous years the extensive network of the distal branches (nerves of Laterjet) over the surface of the distal stomach were important for the operation of highly selective vagotomy. The use of modern PPI's has reduced the need for such highly selective procedures. Branches pass to the coeliac axis and alongside the vessels to supply the spleen, liver and kidney.

Answer 790

The IJV does not lie in the posterior triangle. However, the terminal branches of the external jugular vein do. Posterior triangle of the neck Boundaries Apex Sternocleidomastoid and the Trapezius muscles at the Occipital bone Anterior Posterior border of the Sternocleidomastoid Posterior Anterior border of the Trapezius Base Middle third of the clavicle Contents Nerves Accessory nerve Phrenic nerve Three trunks of the brachial plexus Branches of the cervical plexus: Supraclavicular nerve, transverse cervical nerve, great auricular nerve, lesser occipital nerve Vessels External jugular vein Subclavian artery Muscles Inferior belly of omohyoid Scalene Lymph nodes Supraclavicular Occipital

Answer 791

L3 Prolapsed disc A prolapsed lumbar disc usually produces clear dermatomal leg pain associated with neurological deficits. Features Leg pain usually worse than back Pain often worse when sitting The table below demonstrates the expected features according to the level of compression: L3 nerve root compression Sensory loss over anterior thigh/knee Weak quadriceps Reduced knee reflex Positive femoral stretch test L5 nerve root compression Sensory loss dorsum of foot Weakness in foot and big toe dorsiflexion Reflexes intact Positive sciatic nerve stretch test S1 nerve root compression Sensory loss posterolateral aspect of leg and lateral aspect of foot Weakness in plantar flexion of foot Reduced ankle reflex Positive sciatic nerve stretch test Management Similar to that of other musculoskeletal lower back pain: analgesia, physiotherapy, exercises Persistent symptoms, muscular weakness, bladder or bowel dysfunction are indications for urgent MRI scanning to delineate the disease extent to allow surgical planning Plain spinal x-rays have no useful role in establishing the extent of disc disease

Answer 792

Constrictions of the oesophagus : ABCD A- Arch of the Aorta B- Left main Bronchus C- Cricoid Cartilage D- Diaphragmatic Hiatus The oesophagus is not constricted at the level of the lower oesophageal sphincter. Oesophagus - 25cm long Starts at C6 vertebra, pierces diaphragm at T10 and ends at T11 Squamous epithelium Constrictions of the oesophagus Structure Distance from incisors Cricoid cartilage 15cm Arch of the Aorta 22.5cm Left principal bronchus 27cm Diaphragmatic hiatus 40cm Relations Anteriorly Trachea to T4 Recurrent laryngeal nerve Left bronchus, Left atrium Diaphragm Posteriorly Thoracic duct to left at T5 Hemiazygos to the left T8 Descending aorta First 2 intercostal branches of aorta Left Thoracic duct Left subclavian artery Right Azygos vein Arterial, venous and lymphatic drainage of the oesophagus Artery Vein Lymphatics Muscularis externa Upper third Inferior thyroid Inferior thyroid Deep cervical Striated muscle Mid third Aortic branches Azygos branches Mediastinal Smooth & striated muscle Lower third Left gastric Left gastric Gastric Smooth muscle Nerve supply Upper half is supplied by recurrent laryngeal nerve Lower half by oesophageal plexus (vagus) Histology Mucosa :Non-keratinized stratified squamous epithelium Submucosa: glandular tissue Muscularis externa (muscularis): composition varies. See table Adventitia

Answer 793

JVP 3 Upward deflections and 2 downward deflections Upward deflections a wave = atrial contraction c wave = ventricular contraction v wave = atrial venous filling Downward deflections x wave = atrium relaxes and tricuspid valve moves down y wave = ventricular filling The y descent represents the emptying of the atrium and the filling of the right ventricle. Cardiac physiology - The heart has four chambers ejecting blood into both low pressure and high pressure systems. The pumps generate pressures of between 0-25mmHg on the right side and 0-120 mmHg on the left. At rest diastole comprises 2/3 of the cardiac cycle. The product of the frequency of heart rate and stroke volume combine to give the cardiac output which is typically 5-6L per minute. Detailed descriptions of the various waveforms are often not a feature of MRCS A (although they are on the syllabus). However, they are a very popular topic for surgical physiology in the MRCS B exam. Electrical properties Intrinsic myogenic rhythm within cardiac myocytes means that even the denervated heart is capable of contraction. In the normal situation the cardiac impulse is generated in the sino atrial node in the right atrium and conveyed to the ventricles via the atrioventricular node. The sino atrial node is also capable of spontaneous discharge and in the absence of background vagal tone will typically discharge around 100x per minute. Hence the higher resting heart rate found in cardiac transplant cases. In the SA and AV nodes the resting membrane potential is lower than in surrounding cardiac cells and will slowly depolarise from -70mV to around -50mV at which point an action potential is generated. Differences in the depolarisation slopes between SA and AV nodes help to explain why the SA node will depolarise first. The cells have a refractory period during which they cannot be re-stimulated and this period allows for adequate ventricular filling. In pathological tachycardic states this time period is overridden and inadequate ventricular filling may then occur, cardiac output falls and syncope may ensue. Parasympathetic fibres project to the heart via the vagus and will release acetylcholine. Sympathetic fibres release nor adrenaline and circulating adrenaline comes from the adrenal medulla. Noradrenaline binds to β 1 receptors in the SA node and increases the rate of pacemaker potential depolarisation. Cardiac cycle Mid diastole: AV valves open. Ventricles hold 80% of final volume. Outflow valves shut. Aortic pressure is high. Late diastole: Atria contract. Ventricles receive 20% to complete filling. Typical end diastolic volume 130-160ml. Early systole: AV valves shut. Ventricular pressure rises. Isovolumetric ventricular contraction. AV Valves bulge into atria (c-wave). Aortic and pulmonary pressure exceeded- blood is ejected. Shortening of ventricles pulls atria downwards and drops intra atrial pressure (x-descent). Late systole: Ventricular muscles relax and ventricular pressures drop. Although ventricular pressure drops the aortic pressure remains constant owing to peripheral vascular resistance and elastic property of the aorta. Brief period of retrograde flow that occurs in aortic recoil shuts the aortic valve. Ventricles will contain 60ml end systolic volume. The average stroke volume is 70ml (i.e. Volume ejected). Early diastole: All valves are closed. Isovolumetric ventricular relaxation occurs. Pressure wave associated with closure of the aortic valve increases aortic pressure. The pressure dip before this rise can be seen on arterial waveforms and is called the incisura. During systole the atrial pressure increases such that it is now above zero (v- wave). Eventually atrial pressure exceed ventricular pressure and AV valves open - atria empty passively into ventricles and atrial pressure falls (y -descent ) The negative atrial pressures are of clinical importance as they can allow air embolization to occur if the neck veins are exposed to air. This patient positioning is important in head and neck surgery to avoid this occurrence if veins are inadvertently cut, or during CVP line insertion. Mechanical properties Preload = end diastolic volume Afterload = aortic pressure It is important to understand the principles of Laplace's law in surgery. It states that for hollow organs with a circular cross section, the total circumferential wall tension depends upon the circumference of the wall, multiplied by the thickness of the wall and on the wall tension. The total luminal pressure depends upon the cross sectional area of the lumen and the transmural pressure. Transmural pressure is the internal pressure minus external pressure and at equilibrium the total pressure must counterbalance each other. In terms of cardiac physiology the law explains that the rise in ventricular pressure that occurs during the ejection phase is due to physical change in heart size. It also explains why a dilated diseased heart will have impaired systolic function. Starlings law Increase in end diastolic volume will produce larger stroke volume. This occurs up to a point beyond which cardiac fibres are excessively stretched and stroke volume will fall once more. It is important for the regulation of cardiac output in cardiac transplant patients who need to increase their cardiac output. Baroreceptor reflexes Baroreceptors located in aortic arch and carotid sinus. Aortic baroreceptor impulses travel via the vagus and from the carotid via the glossopharyngeal nerve. They are stimulated by arterial stretch. Even at normal blood pressures they are tonically active. Increase in baroreceptor discharge causes: *Increased parasympathetic discharge to the SA node. *Decreased sympathetic discharge to ventricular muscle causing decreased contractility and fall in stroke volume. *Decreased sympathetic discharge to venous system causing increased compliance. *Decreased peripheral arterial vascular resistance Atrial stretch receptors Located in atria at junction between pulmonary veins and vena cava. Stimulated by atrial stretch and are thus low pressure sensors. Increased blood volume will cause increased parasympathetic activity. Very rapid infusion of blood will result in increase in heart rate mediated via atrial receptors: the Bainbridge reflex. Decreases in receptor stimulation results in increased sympathetic activity this will decrease renal blood flow-decreases GFR-decreases urinary sodium excretion-renin secretion by juxtaglomerular apparatus-Increase in angiotensin II. Increased atrial stretch will also result in increased release of atrial natriuretic peptide.

Answer 794

Dysphagia lusoria is caused by compression of the esophagus from any of several congenital vascular abnormalities. The vascular abnormality is usually an aberrant right subclavian artery arising from the left side of the aortic arch, a double aortic arch, or a right aortic arch with left ligamentum arteriosum. The dysphagia may develop in childhood or later in life as a result of arteriosclerotic changes in the aberrant vessel. Barium swallow shows the extrinsic compression, but arteriography is necessary for absolute diagnosis. Dysphagia Causes of dysphagia Extrinsic Mediastinal masses Cervical spondylosis Oesophageal wall Achalasia Diffuse oesophageal spasm Hypertensive lower oesophageal sphincter Intrinsic Tumours Strictures Oesophageal web Schatzki rings Neurological CVA Parkinson's disease Multiple Sclerosis Brainstem pathology Myasthenia Gravis Investigation All patients require an upper GI endoscopy unless there are compelling reasons for this not to be performed. Motility disorders may be best appreciated by undertaking fluoroscopic swallowing studies. A full blood count should be performed. Ambulatory oesophageal pH and manometry studies will be required to evaluate conditions such as achalasia and patients with GORD being considered for fundoplication surgery.

Answer 795

Raised intracranial pressure (Cushing response) Hypertension Bradycardia Respiratory depression In the patient described, hypotension and tachycardia should not be uncritically attributed to the head injury, since these findings in the setting of blunt trauma are suggestive of serious thoracic, abdominal, or pelvic hemorrhage. When cardiovascular collapse occurs as a result of rising intracranial pressure, it is generally accompanied by hypertension, bradycardia, and respiratory depression.

Answer 796

The aorta is accompanied by the thoracic duct as it traverses the aortic hiatus. The vagal trunks accompany the oesophagus which passes through the muscular part of the diaphragm on the right. The right phrenic nerve accompanies the IVC as it passes through the caval opening. The left phrenic nerve passes through the muscular part of the diaphragm anterior to the central tendon on the left. Abdominal aorta Abdominal aortic topography Origin T12 Termination L4 Posterior relations L1-L4 Vertebral bodies Anterior relations Lesser omentum Liver Left renal vein Inferior mesenteric vein Third part of duodenum Pancreas Parietal peritoneum Peritoneal cavity Right lateral relations Right crus of the diaphragm Cisterna chyli IVC (becomes posterior distally) Left lateral relations 4th part of duodenum Duodenal-jejunal flexure Left sympathetic trunk

Answer 797

Episodes of hyperacute rejection are typically due to preformed antibodies. ABO mismatch is the best example. However, IgG anti HLA Class I antibodies are another potential cause. These events are now seen less commonly because the cross matching process generally takes this possibility into account. Organ Transplant A number of different organ and tissue transplants are now available. In many cases an allograft is performed, where an organ is transplanted from one individual to another. Allografts will elicit an immune response and this is one of the main reasons for organ rejection. Graft rejection occurs because allografts have allelic differences at genes that code immunohistocompatability complex genes. The main antigens that give rise to rejection are: ABO blood group Human leucocyte antigens (HLA) Minor histocompatability antigens ABO Matching ABO incompatibility will result in early organ rejection (hyperacute) because of pre existing antibodies to other groups. Group O donors can give organs to any type of ABO recipient whereas group AB donor can only donate to AB recipient. HLA System The four most important HLA alleles are: HLA A HLA B HLA C HLA DR An ideal organ match would be one in which all 8 alleles are matched (remember 2 from each parent, four each = 8 alleles). Modern immunosuppressive regimes help to manage the potential rejection due to HLA mismatching. However, the greater the number of mismatches the worse the long term outcome will be. T lymphocytes will recognise antigens bound to HLA molecules and will then become activated. Clonal expansion then occurs with a response directed against that antigen. Types of organ rejection Hyperacute. This occurs immediately through presence of pre formed antibodies (such as ABO incompatibility). Acute. Occurs during the first 6 months and is usually T cell mediated. Usually tissue infiltrates and vascular lesions. Chronic. Occurs after the first 6 months. Vascular changes predominate. Hyperacute Renal transplants at greatest risk and liver transplants at least risk. Although ABO incompatibility and HLA Class I incompatible transplants will all fare worse in long term. Acute All organs may undergo acute rejection. Mononuclear cell infiltrates predominate. All types of transplanted organ are susceptible and it may occur in up to 50% cases. Chronic Again all transplants with HLA mismatch may suffer this fate. Previous acute rejections and other immunosensitising events all increase the risk. Vascular changes are most prominent with myointimal proliferation leading to organ ischaemia. Organ specific changes are also seen such as loss of acinar cells in pancreas transplants and rapidly progressive coronary artery disease in cardiac transplants. Surgical overview-Renal transplantation A brief overview of the steps involved in renal transplantation is given. Patients with end stage renal failure who are dialysis dependent or likely to become so in the immediate future are considered for transplant. Exclusion criteria include; active malignancy, old age (due to limited organ availability). Patients are medically optimised. Donor kidneys, these may be taken from live related donors and close family, members may have less HLA mismatch than members of the general population. Laparoscopic donor nephrectomy further minimises the operative morbidity for the donor. Other organs are typically taken from brain dead or dying patients who have a cardiac arrest and in whom resuscitation is futile. The key event is to minimise the warm ischaemic time in the donor phase. The kidney once removed is usually prepared on the bench in theatre by the transplant surgeon immediately prior to implantation and factors such as accessory renal arteries and vessel length are assessed and managed. For first time recipients the operation is performed under general anaesthesia. A Rutherford-Morison incision is made on the preferred side. This provides excellent extraperitoneal access to the iliac vessels. The external iliac artery and vein are dissected out and following systemic heparinisation are cross clamped. The vein and artery are anastamosed to the iliacs and the clamps removed. The ureter is then implanted into the bladder and a stent is usually placed to maintain patency. The wounds are then closed and the patient recovered from surgery. In the immediate phase a common problem encountered in cadaveric kidneys is acute tubular necrosis and this tends to resolve. Graft survival times from cadaveric donors are typically of the order of 9 years and monozygotic twin transplant (live donor) may survive as long as 25 years.

Answer 798

APKD is associated with liver cysts (70%), berry aneurysms (25%) and pancreatic cysts (10%). Patients may have a renal mass, hypertension, renal calculi and macroscopic haematuria. Haematuria Causes of haematuria Trauma Injury to renal tract Renal trauma commonly due to blunt injury (others penetrating injuries) Ureter trauma rare: iatrogenic Bladder trauma: due to RTA or pelvic fractures Infection Remember TB Malignancy Renal cell carcinoma (remember paraneoplastic syndromes): painful or painless Urothelial malignancies: 90% are transitional cell carcinoma, can occur anywhere along the urinary tract. Painless haematuria. Squamous cell carcinoma and adenocarcinoma: rare bladder tumours Prostate cancer Penile cancers: SCC Renal disease Glomerulonephritis Stones Microscopic haematuria common Structural abnormalities Benign prostatic hyperplasia (BPH) causes haematuria due to hypervascularity of the prostate gland Cystic renal lesions e.g. polycystic kidney disease Vascular malformations Renal vein thrombosis due to renal cell carcinoma Coagulopathy Causes bleeding of underlying lesions Drugs Cause tubular necrosis or interstitial nephritis: aminoglycosides, chemotherapy Interstitial nephritis: penicillin, sulphonamides, and NSAIDs Anticoagulants Benign Exercise Gynaecological Endometriosis: flank pain, dysuria, and haematuria that is cyclical Iatrogenic Catheterisation Radiotherapy; cystitis, severe haemorrhage, bladder necrosis Pseudohaematuria For example following consumption of beetroot References Http://bestpractice.bmj.com/best-practice/monograph/316/overview/aetiology.html

Answer 799

The laryngeal branches of the vagus supply sensory information from the larynx. Larynx The larynx lies in the anterior part of the neck at the levels of C3 to C6 vertebral bodies. The laryngeal skeleton consists of a number of cartilagenous segments. Three of these are paired; arytenoid, corniculate and cuneiform. Three are single; thyroid, cricoid and epiglottic. The cricoid cartilage forms a complete ring (the only one to do so). The laryngeal cavity extends from the laryngeal inlet to the level of the inferior border of the cricoid cartilage. Divisions of the laryngeal cavity Laryngeal vestibule Superior to the vestibular folds Laryngeal ventricle Lies between vestibular folds and superior to the vocal cords Infraglottic cavity Extends from vocal cords to inferior border of the cricoid cartilage The vocal folds (true vocal cords) control sound production. The apex of each fold projects medially into the laryngeal cavity. Each vocal fold includes: Vocal ligament Vocalis muscle (most medial part of thyroarytenoid muscle) The glottis is composed of the vocal folds, processes and rima glottidis. The rima glottidis is the narrowest potential site within the larynx, as the vocal cords may be completely opposed, forming a complete barrier. Muscles of the larynx Muscle Origin Insertion Innervation Action Posterior cricoarytenoid Posterior aspect of lamina of cricoid Muscular process of arytenoid Recurrent Laryngeal Abducts vocal fold Lateral cricoarytenoid Arch of cricoid Muscular process of arytenoid Recurrent laryngeal Adducts vocal fold Thyroarytenoid Posterior aspect of thyroid cartilage Muscular process of arytenoid Recurrent laryngeal Relaxes vocal fold Transverse and oblique arytenoids Arytenoid cartilage Contralateral arytenoid Recurrent laryngeal Closure of intercartilagenous part of the rima glottidis Vocalis Depression between lamina of thyroid cartilage Vocal ligament and vocal process of arytenoid cartilage Recurrent laryngeal Relaxes posterior vocal ligament, tenses anterior part Cricothyroid Anterolateral part of cricoid Inferior margin and horn of thyroid cartilage External laryngeal Tenses vocal fold Blood supply Arterial supply is via the laryngeal arteries, branches of the superior and inferior thyroid arteries. The superior laryngeal artery is closely related to the internal laryngeal nerve. The inferior laryngeal artery is related to the inferior laryngeal nerve. Venous drainage is via superior and inferior laryngeal veins, the former draining into the superior thyroid vein and the latter draining into the middle thyroid vein, or thyroid venous plexus. Lymphatic drainage The vocal cords have no lymphatic drainage and this site acts as a lymphatic watershed. Supraglottic part Upper deep cervical nodes Subglottic part Prelaryngeal and pretracheal nodes and inferior deep cervical nodes The aryepiglottic fold and vestibular folds have a dense plexus of lymphatics associated with them and malignancies at these sites have a greater propensity for nodal metastasis.

Answer 800

Peritrochanteric lesions have the greatest risks of fracture (due to loading). The lesions from breast cancer are usually lytic and therefore at higher risk rather than the sclerotic lesions from prostate cancer. Metastatic bone disease- risk of fracture Metastatic bone tumours may be described as blastic, lytic or mixed. Osteoblastic metastatic disease has the lowest risk of spontaneous fracture when compared to osteolytic lesions of a similar size. Lesions affecting the peritrochanteric region are most prone to spontaneous fracture (because of loading forces at that site). The factors are incorporated into the Mirel Scoring system to stratify the risk of spontaneous fracture for bone metastasis of varying types. Mirel Scoring system Score points Site Radiographic appearance Width of bone involved Pain 1 Upper extremity Blastic Less than 1/3 Mild 2 Lower extremity Mixed 1/3 to 2/3 Moderate 3 Peritrochanteric Lytic More than 2/3 Aggravated by function Depending upon the score the treatment should be as follows: Score Risk of fracture Treatment 9 or greater Impending (33%) Prophylactic fixation 8 Borderline Consider fixation 7 or less Not impending (4%) Non operative management

Answer 801

The auriculotemporal nerve is a direct branch of the mandibular nerve. Other branches of the mandibular nerve include: Lingual Inferior alveolar Nerve to the mylohyoid Mental Facial nerve The facial nerve is the main nerve supplying the structures of the second embryonic branchial arch. It is predominantly an efferent nerve to the muscles of facial expression, digastric muscle and also to many glandular structures. It contains a few afferent fibres which originate in the cells of its genicular ganglion and are concerned with taste. Supply - 'face, ear, taste, tear' Face: muscles of facial expression Ear: nerve to stapedius Taste: supplies anterior two-thirds of tongue Tear: parasympathetic fibres to lacrimal glands, also salivary glands Path Subarachnoid path Origin: motor- pons, sensory- nervus intermedius Pass through the petrous temporal bone into the internal auditory meatus with the vestibulocochlear nerve. Here they combine to become the facial nerve. Facial canal path The canal passes superior to the vestibule of the inner ear At the medial aspect of the middle ear, it becomes wider and contains the geniculate ganglion. - 3 branches: 1. greater petrosal nerve 2. nerve to stapedius 3. chorda tympani Stylomastoid foramen Passes through the stylomastoid foramen (tympanic cavity anterior and mastoid antrum posteriorly) Posterior auricular nerve and branch to posterior belly of digastric and stylohyoid muscle Face Enters parotid gland and divides into 5 branches: Temporal branch Zygomatic branch Buccal branch Marginal mandibular branch Cervical branch

Answer 802

The chorda tympani runs medially to the pars flaccida. Ear- anatomy The ear is composed of three anatomically distinct regions. External ear Auricle is composed of elastic cartilage covered by skin. The lobule has no cartilage and contains fat and fibrous tissue. External auditory meatus is approximately 2.5cm long. Lateral third of the external auditory meatus is cartilaginous and the medial two thirds is bony. The region is innervated by the greater auricular nerve. The auriculotemporal branch of the trigeminal nerve supplies most of the external auditory meatus and the lateral surface of the auricle. Middle ear Space between the tympanic membrane and cochlea. The aditus leads to the mastoid air cells is the route through which middle ear infections may cause mastoiditis. Anteriorly the eustacian tube connects the middle ear to the naso pharynx. The tympanic membrane consists of: Outer layer of stratified squamous epithelium. Middle layer of fibrous tissue. Inner layer of mucous membrane continuous with the middle ear. The tympanic membrane is approximately 1cm in diameter. The chorda tympani nerve passes on the medial side of the pars flaccida. The middle ear is innervated by the glossopharyngeal nerve and pain may radiate to the middle ear following tonsillectomy. Ossicles Malleus attaches to the tympanic membrane (the Umbo). Malleus articulates with the incus (synovial joint). Incus attaches to stapes (another synovial joint). Internal ear Cochlea, semi circular canals and vestibule Organ of corti is the sense organ of hearing and is located on the inside of the cochlear duct on the basilar membrane. Vestibule accommodates the utricule and the saccule. These structures contain endolymph and are surrounded by perilymph within the vestibule. The semicircular canals lie at various angles to the petrous temporal bone. All share a common opening into the vestibule.

Answer 803

Crohns disease is a contra indication to having an ileo-anal pouch as its associated with very poor pouch function and significant complications. Whilst the patient wishes to avoid a stoma, that's inevitable here. Surgery for inflammatory bowel disease Patients with inflammatory bowel disease (UC and Crohns) frequently present in surgical practice. Ulcerative colitis may be cured by surgical resection (Proctocolectomy), this is not the case in Crohns disease which may recur and affect other areas of the gastrointestinal tract. Ulcerative colitis Elective indications for surgery include disease that is requiring maximal therapy, or prolonged courses of steroids. Longstanding UC is associated with a risk of malignant transformation. Dysplastic transformation of the colonic epithelium with associated mass lesions is an absolute indication for a proctocolectomy. Emergency presentations of poorly controlled colitis that fails to respond to medical therapy should usually be managed with a sub total colectomy. Excision of the rectum is a procedure with a higher morbidity and is not generally performed in the emergency setting. An end ileostomy is usually created and the rectum either stapled off and left in situ, or, if the bowel is very oedematous, may be brought to the surface as a mucous fistula. Patients with IBD have a high incidence of DVT and appropriate thromboprophylaxis is mandatory. Restorative options in UC include an ileoanal pouch. This procedure can only be performed whilst the rectum is in situ and cannot usually be undertaken as a delayed procedure following proctectomy. Ileoanal pouch complications include, anastomotic dehiscence, pouchitis and poor physiological function with seepage and soiling. Crohns disease Surgical resection of Crohns disease does not equate with cure, but may produce substantial symptomatic improvement. Indications for surgery include complications such as fistulae, abscess formation and strictures. Extensive small bowel resections may result in short bowel syndrome and localised stricturoplasty may allow preservation of intestinal length. Staging of Crohns will usually involve colonoscopy and a small bowel study (e.g. MRI enteroclysis). Complex perianal fistulae are best managed with long term draining seton sutures, complex attempts at fistula closure e.g. advancement flaps, may be complicated by non healing and fistula recurrence. Severe perianal and / or rectal Crohns may require proctectomy. Ileoanal pouch reconstruction in Crohns carries a high risk of fistula formation and pouch failure and is not recommended. Terminal ileal Crohns remains the commonest disease site and these patients may be treated with limited ileocaecal resections. Terminal ileal Crohns may affect enterohepatic bile salt recycling and increase the risk of gallstones.

Answer 804

Streptococcus bovis septicaemia is associated with carcinoma of the colon. It can also cause endocarditis. Streptococcus bovis is a gram positive organism. In most cases, its portal of entry is via the GI tract and for that reason its typically associated with large bowel malignancy. Surgical Microbiology An extensive topic so an overview is given here. Organisms causing common surgical infections are reasonable topics in the examination. However, microbiology is less rigorously tested than anatomy, for example. Common organisms Staphylococcus aureus Facultative anaerobe Gram positive coccus Haemolysis on blood agar plates Catalase positive 20% population are long term carriers Exo and entero toxin may result in toxic shock syndrome and gastroenteritis respectively Ideally treated with penicillin although many strains now resistant through beta Lactamase production. In the UK less than 5% of isolates are sensitive to penicillin. Resistance to methicillin (and other antibiotics) is mediated by the mec operon , essentially penicillin binding protein is altered and resistance to this class of antibiotics ensues Common cause of cutaneous infections and abscesses Streptococcus pyogenes Gram positive, forms chain like colonies, Lancefield Group A Streptococcus Produces beta haemolysis on blood agar plates Rarely part of normal skin microflora Catalase negative Releases a number of proteins/ virulence factors into host including hyaluronidase, streptokinase which allow rapid tissue destruction Releases superantigens such as pyogenic exotoxin A which results in scarlet fever Remains sensitive to penicillin, macrolides may be used as an alternative. Escherichia coli Gram negative rod Facultative anaerobe, non sporing Wide range of subtypes and some are normal gut commensals Some subtypes such as 0157 may produce lethal toxins resulting in haemolytic-uraemic syndrome Enterotoxigenic E-Coli produces an enterotoxin (ST enterotoxin) that results in large volume fluid secretion into the gut lumen (Via cGMP activation) Enteropathogenic E-Coli binds to intestinal cells and cause structural damage, this coupled with a moderate (or in case of enteroinvasive E-Coli significant) invasive component produces enteritis and large volume diarrhoea together with fever. They are resistant to many antibiotics used to treat gram positive infections and acquire resistance rapidly and are recognised as producing beta lactamases Campylobacter jejuni Curved, gram negative, non sporulating bacteria One of the commonest causes of diarrhoea worldwide Produces enteritis which is often diffuse and blood may be passed Remains a differential for right iliac fossa pain with diarrhoea Self limiting infection so antibiotics are not usually advised. However, the quinolones are often rapidly effective. Helicobacter pylori Gram negative, helix shaped rod, microaerophillic Produces hydrogenase that can derive energy from hydrogen released by intestinal bacteria Flagellated and mobile Those carrying the cag A gene may cause ulcers It secretes urease that breaks down gastric urea> Carbon dioxide and ammonia> ammonium>bicarbonate (simplified!) The bicarbonate can neutralise the gastric acid. Usually colonises the gastric antrum and irritates resulting in increased gastrin release and higher levels of gastric acid. These patients will develop duodenal ulcers. In those with more diffuse H-Pylori infection gastric acid levels are lower and ulcers develop by local tissue damage from H-Pylori- these patients get gastric ulcers. Diagnosis may be made by serology (approx. 75% sensitive). Biopsy urease test during endoscopy probably the most sensitive. In patients who are colonised 10-20% risk of peptic ulcer, 1-2% risk gastric cancer, <1% risk MALT lymphoma.

Answer 805

Secretin is released from mucosal cells in the duodenum and jejunum. Pancreas endocrine physiology Hormones released from the islets of Langerhans Beta cells Insulin (70% of total secretions) Alpha cells Glucagon Delta cells Somatostatin F cells Pancreatic polypeptide

Answer 806

Patients can generally be managed without transfusion as long as the Hb is 7 or greater. The exact level depends upon patient factors such as co-morbidities. Old blood functions less effectively and should not be used during massive transfusions.

Answer 807

Twisting sporting injuries followed by delayed onset of knee swelling and locking are strongly suggestive of a menisceal tear. Arthroscopic menisectomy is the usual treatment. Knee injury Types of injury Ruptured anterior cruciate ligament Sport injury Mechanism: high twisting force applied to a bent knee Typically presents with: loud crack, pain and RAPID joint swelling (haemoarthrosis) Poor healing Management: intense physiotherapy or surgery Ruptured posterior cruciate ligament Mechanism: hyperextension injuries Tibia lies back on the femur Paradoxical anterior draw test Rupture of medial collateral ligament Mechanism: leg forced into valgus via force outside the leg Knee unstable when put into valgus position Menisceal tear Rotational sporting injuries Delayed knee swelling Joint locking (Patient may develop skills to 'unlock' the knee Recurrent episodes of pain and effusions are common, often following minor trauma Chondromalacia patellae Teenage girls, following an injury to knee e.g. Dislocation patella Typical history of pain on going downstairs or at rest Tenderness, quadriceps wasting Dislocation of the patella Most commonly occurs as a traumatic primary event, either through direct trauma or through severe contraction of quadriceps with knee stretched in valgus and external rotation Genu valgum, tibial torsion and high riding patella are risk factors Skyline x-ray views of patella are required, although displaced patella may be clinically obvious An osteochondral fracture is present in 5% The condition has a 20% recurrence rate Fractured patella 2 types: i. Direct blow to patella causing undisplaced fragments ii. Avulsion fracture Tibial plateau fracture Occur in the elderly (or following significant trauma in young) Mechanism: knee forced into valgus or varus, but the knee fractures before the ligaments rupture Varus injury affects medial plateau and if valgus injury, lateral plateau depressed fracture occurs Classified using the Schatzker system (see below) Schatzker Classification system for tibial plateau fractures Type Anatomical description Features 1 Vertical split of lateral condyle Fracture through dense bone, usually in the young. It may be virtually undisplaced, or the condylar fragment may be pushed inferiorly and tilted 2 Vertical split of the lateral condyle combined with an adjacent load bearing part of the condyle The wedge fragment (which may be of variable size), is displaced laterally; the joint is widened. Untreated, a valgus deformity may develop 3 Depression of the articular surface with intact condylar rim The split does not extend to the edge of the plateau. Depressed fragments may be firmly embedded in subchondral bone, the joint is stable 4 Fragment of the medial tibial condyle Two injuries are seen in this category; (1) a depressed fracture of osteoporotic bone in the elderly. (2) a high energy fracture resulting in a condylar split that runs from the intercondylar eminence to the medial cortex. Associated ligamentous injury may be severe 5 Fracture of both condyles Both condyles fractured but the column of the metaphysis remains in continuity with the tibial shaft 6 Combined condylar and subcondylar fractures High energy fracture with marked comminution

Answer 808

Some may argue for local therapy. However, in young patients who are otherwise fit, multifocal disease such as this should probably be resected. (Debatable answer. Perplexity answer at the end) Treatment of oesophageal cancer - In general resections are not offered to those patients with distant metastasis, and usually not to those with N2 disease. Local nodal involvement is not in itself a contra indication to resection. Surgical resection is the mainstay of treatment. Neoadjuvent chemotherapy is given in most cases prior to surgery. In situ disease may be managed by endoscopic mucosal resection, although this is still debated. In patients with lower third lesions an Ivor - Lewis type procedure is most commonly performed. Very distal tumours may be suitable to a transhiatal procedure. Which is an attractive option as the penetration of two visceral cavities required for an Ivor- Lewis type procedure increases the morbidity considerably. More proximal lesions will require a total oesphagectomy (Mckeown type) with anastomosis to the cervical oesophagus. Patients with unresectable disease may derive benefit from local ablative procedures, palliative chemotherapy or stent insertion. Operative details of Ivor- Lewis procedure Combined laparotomy and right thoracotomy Indication Lower and middle third oesophageal tumours Preparation Staging with a combination of CT chest abdomen and pelvis- if no metastatic disease detected then patients will undergo a staging laparoscopy to detect peritoneal disease. If both these modalities are negative then patients will finally undergo a PET CT scan to detect occult metastatic disease. Only in those whom no evidence of advanced disease is detected will proceed to resection. Patients receive a GA, double lumen endotracheal tube to allow for lung deflation, CVP and arterial monitoring. Procedure A rooftop incision is made to access the stomach and duodenum. Laparotomy To mobilize the stomach The greater omentum is incised away from its attachment to the right gastroepiploic vessels along the greater curvature of the stomach. Then the short gastric vessels are ligated and detached from the greater curvature from the spleen. The lesser omentum is incised, preserving the right gastric artery. The retroperitoneal attachments of the duodenum in its second and third portions are incised, allowing the pylorus to reach the oesophageal hiatus. Some surgeons perform a pyloroplasty at this point to facilitate gastric emptying. The left gastric vessels are then ligated, avoiding any injury to the common hepatic or splenic arteries. Care must be taken to avoid inadvertently devascularising the liver owing to variations in anatomy. Right Thoracotomy Oesophageal resection and oesophagogastric anastomosis Through 5th intercostal space Dissection performed 10cm above the tumour This may involve transection of the azygos vein. The oesophagus is then removed with the stomach creating a gastric tube. An anastomosis is created. The chest is closed with underwater seal drainage and tube drains to the abdominal cavity. Post operatively Patients will typically recover in ITU initially. A nasogastric tube will have been inserted intraoperatively and must remain in place during the early phases of recovery. Post operatively these patients are at relatively high risk of developing complications: * Atelectasis- due to the effects of thoracotomy and lung collapse * Anastomotic leakage. The risk is relatively high owing to the presence of a relatively devascularised stomach. Often the only blood supply is from the gastroepiploic artery as all others will have been divided. If a leak does occur then many will attempt to manage conservatively with prolonged nasogastric tube drainage and TPN. The reality is that up to 50% of patients developing an anastomotic leak will not survive to discharge. * Delayed gastric emptying (may be avoided by performing a pyloroplasty). The best course of action for a 52-year-old man with long-standing Barrett's esophagus diagnosed with multifocal, mainly distally sited high-grade dysplasia is endoscopic surveillance at 3-month intervals. According to a clinical practice update on endoscopic surveillance and management of dysplasia, endoscopic surveillance is recommended for patients with high-grade dysplasia. This approach allows for close monitoring of the condition and enables early intervention if the dysplasia progresses. Other options such as photodynamic therapy, Nissen's fundoplication, esophagectomy, or external beam radiotherapy may be considered based on individual patient factors and the progression of the dysplasia, but the initial recommended approach is endoscopic surveillance

Answer 809

The cutaneous branch of the obturator nerve is frequently absent. However, the obturator nerve is a recognised contributor to innervation of the medial thigh and large pelvic tumours may compress this nerve with resultant pain radiating distally. Obturator nerve The obturator nerve arises from L2, L3 and L4 by branches from the ventral divisions of each of these nerve roots. L3 forms the main contribution and the second lumbar branch is occasionally absent. These branches unite in the substance of psoas major, descending vertically in its posterior part to emerge from its medial border at the lateral margin of the sacrum. It then crosses the sacroiliac joint to enter the lesser pelvis, it descends on obturator internus to enter the obturator groove. In the lesser pelvis the nerve lies lateral to the internal iliac vessels and ureter, and is joined by the obturator vessels lateral to the ovary or ductus deferens. Supplies Medial compartment of thigh Muscles supplied: external obturator, adductor longus, adductor brevis, adductor magnus (not the lower part-sciatic nerve), gracilis The cutaneous branch is often absent. When present, it passes between gracilis and adductor longus near the middle part of the thigh, and supplies the skin and fascia of the distal two thirds of the medial aspect. Obturator canal Connects the pelvis and thigh: contains the obturator artery, vein, nerve which divides into anterior and posterior branches. Cadaveric cross section demonstrating relationships of the obturator nerve

Answer 810

The foramen spinosum transmits the middle meningeal artery. The foramen ovale transmits the mandibular nerve. As the foramina weaken the bone, a fracture at this site is not uncommon. Foramina of the base of the skull Foramen Location Contents Foramen ovale Sphenoid bone Otic ganglion V3 (Mandibular nerve:3rd branch of trigeminal) Accessory meningeal artery Lesser petrosal nerve Emissary veins Foramen spinosum Sphenoid bone Middle meningeal artery Meningeal branch of the Mandibular nerve Foramen rotundum Sphenoid bone Maxillary nerve (V2) Foramen lacerum/ carotid canal Located between the sphenoid, the apex of the petrous temporal and the basilar part of the occipital Base of the medial pterygoid plate. Internal carotid artery* Nerve and artery of the pterygoid canal Jugular foramen Temporal bone Anterior: inferior petrosal sinus Intermediate: glossopharyngeal, vagus, and accessory nerves. Posterior: sigmoid sinus (becoming the internal jugular vein) and some meningeal branches from the occipital and ascending pharyngeal arteries. Foramen magnum Occipital bone Anterior and posterior spinal arteries Vertebral arteries Medulla oblongata Stylomastoid foramen Temporal bone Stylomastoid artery Facial nerve Superior orbital fissure Sphenoid bone Oculomotor nerve (III) Recurrent meningeal artery Trochlear nerve (IV) Lacrimal, frontal and nasociliary branches of opthalmic nerve (V1) Abducent nerve (VI) Superior ophthalmic vein *= In life the foramen lacerum is occluded by a cartilagenous plug. The ICA initially passes into the carotid canal which ascends superomedially to enter the cranial cavity through the foramen lacerum.

Answer 811

% 5 70 Kg male = 42 L water (60% of total body weight) Fluid compartment physiology Body fluid compartments comprise intracellular and extracellular compartments. The latter includes interstitial fluid, plasma and transcellular fluid. Typical figures are based on the 70 Kg male. Body fluid volumes Compartment Volume in litres Percentage of total volume Intracellular 28 L 60-65% Extracellular 14 L 35-40% Plasma 3 L 5% Interstitial 10 L 24% Transcellular 1 L 3% Figures are approximate

Answer 812

This patient has syringomyelia which selectively affects the spinotholamic tracts. Syringomyelia is a disorder in which a cystic cavity forms within the spinal cord. The commonest variant is the Arnold- Chiari malformation in which the cavity connects with a congenital malformation affecting the cerebellum. Acquired forms of the condition may occur as a result of previous meningitis, surgery or tumours. Many neurological manifestations have been reported, although the classical variety spares the dorsal columns and medial lemniscus and affecting only the spinothalamic tract with loss of pain and temperature sensation. The bilateral distribution of this patients symptoms would therefore favor syringomyelia over SCID or Brown Sequard syndrome. Osteomyelitis would tend to present with back pain and fever in addition to any neurological signs. Epidural haematoma large enough to produce neurological impairment will usually have motor symptoms in addition to any selective sensory loss, and the history is usually shorter.

Answer 813

Branchial cysts are usually located laterally and derived from the second branchial cleft. Unless infection has occurred they will usually have an anechoic appearance on ultrasound. Neck Masses in Children Thyroglossal cyst Located in the anterior triangle, usually in the midline and below the hyoid (65% cases) Derived from remnants of the thyroglossal duct Thin walled and anechoic on USS (echogenicity suggests infection of cyst) Branchial cyst Six branchial arches separated by branchial clefts Incomplete obliteration of the branchial apparatus may result in cysts, sinuses or fistulae 75% of branchial cysts originate from the second branchial cleft Usually located anterior to the sternocleidomastoid near the angle of the mandible Unless infected the fluid of the cyst has a similar consistency to water and is anechoic on USS Dermoids Derived from pleuripotent stem cells and are located in the midline Most commonly in a suprahyoid location They have heterogeneous appearances on imaging and contain variable amounts of calcium and fat Thyroid gland True thyroid lesions are rare in children and usually represent thyroglossal cysts or tumours like lymphoma Lymphatic malformations Usually located posterior to the sternocleidomastoid Cystic hygroma result from occlusion of lymphatic channels The painless, fluid filled, lesions usually present prior to the age of 2 They are often closely linked to surrounding structures and surgical removal is difficult They are typically hypoechoic on USS Infantile haemangioma May present in either triangle of the neck Grow rapidly initially and then will often spontaneously regress Plain x-rays will show a mass lesion, usually containing calcified phleboliths As involution occurs the fat content of the lesions increases Lymphadenopathy Located in either triangle of the neck May be reactive or neoplastic Generalised lymphadenopathy usually secondary to infection in children (very common)

Answer 814

The vessels supplying the omentum are the omental branches of the right and left gastro-epiploic arteries. The colonic vessels are not responsible for the arterial supply to the omentum. The left gastro-epiploic artery is a branch of the splenic artery and the right gastro-epiploic artery is a terminal branch of the gastroduodenal artery. Omentum The omentum is divided into two parts which invest the stomach. Giving rise to the greater and lesser omentum. The greater omentum is attached to the inferolateral border of the stomach and houses the gastro-epiploic arteries. It is of variable size but is less well developed in children. This is important as the omentum confers protection against visceral perforation (e.g. Appendicitis). Inferiorly between the omentum and transverse colon is one potential entry point into the lesser sac. Several malignant processes may involve the omentum of which ovarian cancer is the most notable.

Answer 815

The term septic shock has a precise meaning and refers to refractory systemic arterial hypotension in spite of fluid resuscitation. Patients will therefore usually require vasopressors. Individuals suffering from neurogenic shock will usually receive intravenous fluids to achieve a mean arterial pressure of 90mmHg. If this target cannot be achieved then these patients will receive inotropes. Hypovolaemic shock requires fluids and the management of cardiogenic shock is multifactorial and includes inotropes, vasodilators and intra-aortic balloon pumps. Inotropes and cardiovascular receptors Inotropes are a class of drugs which work primarily by increasing cardiac output. They should be distinguished from vasoconstrictor drugs which are used specifically when the primary problem is peripheral vasodilatation. Catecholamine type agents are commonly used and work by increasing cAMP levels by adenylate cyclase stimulation. This in turn increases intracellular calcium ion mobilisation and thus the force of contraction. Adrenaline works as a beta adrenergic receptor agonist at lower doses and an alpha receptor agonist at higher doses. Dopamine causes dopamine receptor mediated renal and mesenteric vascular dilatation and beta 1 receptor agonism at higher doses. This results in increased cardiac output. Since both heart rate and blood pressure are raised, there is less overall myocardial ischaemia. Dobutamine is a predominantly beta 1 receptor agonist with weak beta 2 and alpha receptor agonist properties. Noradrenaline is a catecholamine type agent and predominantly acts as an alpha receptor agonist and serves as a peripheral vasoconstrictor. Phosphodiesterase inhibitors such as milrinone act specifically on the cardiac phosphodiesterase and increase cardiac output. Inotrope Cardiovascular receptor action Adrenaline α-1, α-2, β-1, β-2 Noradrenaline α-1,( α-2), (β-1), (β-2) Dobutamine β-1, (β 2) Dopamine (α-1), (α-2), (β-1), D-1,D-2 Minor receptor effects in brackets Effects of receptor binding α-1, α-2 vasoconstriction β-1 increased cardiac contractility and HR β-2 vasodilatation D-1 renal and spleen vasodilatation D-2 inhibits release of noradrenaline

Answer 816

This is associated with transfusion of unirradiated blood in immunosuppressed patients. Transfusion associated GVHD can occur 4-30 days after a transfusion and follows a sub acute pathway. Patients may also have diarrhoea and abnormal liver function tests. Management involves steroid therapy. Blood transfusion reactions Acute transfusion reactions present as adverse signs or symptoms during or within 24 hours of a blood transfusion. The most frequent reactions are fever, chills, pruritus, or urticaria, which typically resolve promptly without specific treatment or complications. Other signs occurring in temporal relationship with a blood transfusion, such as severe dyspnoea, pyrexia, or loss of consciousness may be the first indication of a more severe potentially fatal reaction. The causes of adverse reactions are multi-factorial. Immune mediated reactions, some of the most feared, occur as a result of component mismatch, the commonest cause of which is clerical error. More common, non immune mediated, complications may occur as a result of product contamination, this may be bacterial or viral. Transfusion related lung injury is well recognised and there are two proposed mechanisms which underpin this. One involves the sequestration of primed neutrophils within the recipient pulmonary capillary bed. The other proposed mechanism suggests that HLA mismatches between donor neutrophils and recipient lung tissue is to blame. The table below summarises the main types of transfusion reaction. Immune mediated Non immune mediated Pyrexia Hypocalcaemia Alloimmunization CCF Thrombocytopaenia Infections Transfusion associated lung injury Hyperkalaemia Graft vs Host disease Urticaria Acute or delayed haemolysis ABO incompatibility Rhesus incompatibility

Answer 817

Yersinia can be mistaken for acute appendicitis due to mesenteric lymphadenitis and ileitis. Yersinia infection of the terminal ileum typically produces more marked clinical changes of this segment of bowel than infection with campylobacter. Yersinia pestis causes plague. Bacterial Gastroenteritis Causative organisms Features Campylobacter jejuni Most common cause of acute infective diarrhoea Spiral, gram negative rods Usually infects caecum and terminal ileum. Local lymphadenopathy is common May mimic appendicitis as it has marked right iliac fossa pain Reactive arthritis is seen in 1-2% of cases Shigella spp. Members of the enterobacteriaceae Gram negative bacilli Clinically causes dysentery Shigella soneii is the commonest infective organism (mild illness) Usually self limiting, ciprofloxacin may be required if individual is in a high risk group Salmonella spp Facultatively anaerobic, gram negative, enterobacteriaceae Infective dose varies according to subtype Salmonellosis: usually transmitted by infected meat (especially poultry) and eggs E. coli Enteropathogenic Enteroinvasive: dysentery, large bowel necrosis/ulcers Enterotoxigenic: small intestine, travelers diarrhoea Enterohaemorrhagic: 0157, cause a haemorrhagic colitis, haemolytic uraemic syndrome and thrombotic thrombocytopaenic purpura Yersinia enterocolitica Gram negative, coccobacilli Typically produces a protracted terminal ileitis that may mimic Crohns disease Differential diagnosis acute appendicitis May progress to septicaemia in susceptible individuals Usually sensitive to quinolone or tetracyclines Vibrio cholera Short, gram negative rods Transmitted by contaminated water, seafood Symptoms include sudden onset of effortless vomiting and profuse watery diarrhoea Correction of fluid and electrolyte losses are the mainstay of treatment Most cases will resolve, antibiotics are not generally indicated

Answer 818

Mnemonic to remember factors affecting wound healing: DID NOT HEAL D iabetes I nfection, irradiation D rugs eg steroids, chemotherapy N utritional deficiencies (vitamin A, C & zinc, manganese), Neoplasia O bject (foreign material) T issue necrosis H ypoxia E xcess tension on wound A nother wound L ow temperature, Liver jaundice Multiple sclerosis is associated with pressure sores, however the cellular healing process is not affected. Wound healing Surgical wounds are either incisional or excisional and either clean, clean contaminated or dirty. Although the stages of wound healing are broadly similar their contributions will vary according to the wound type. The main stages of wound healing include: Haemostasis Minutes to hours following injury Vasospasm in adjacent vessels, platelet plug formation and generation of fibrin rich clot. Inflammation Typically days 1-5 Neutrophils migrate into wound (function impaired in diabetes). Growth factors released, including basic fibroblast growth factor and vascular endothelial growth factor. Fibroblasts replicate within the adjacent matrix and migrate into wound. Macrophages and fibroblasts couple matrix regeneration and clot substitution. Regeneration Typically days 7 to 56 Platelet derived growth factor and transformation growth factors stimulate fibroblasts and epithelial cells. Fibroblasts produce a collagen network. Angiogenesis occurs and wound resembles granulation tissue. Remodeling From 6 weeks to 1 year Longest phase of the healing process and may last up to one year (or longer). During this phase fibroblasts become differentiated (myofibroblasts) and these facilitate wound contraction. Collagen fibres are remodeled. Microvessels regress leaving a pale scar. The above description represents an idealised scenario. A number of diseases may distort this process. Neovascularisation is an important early process. Endothelial cells may proliferate in the wound bed and recanalise to form a vessel. Vascular disease, shock and sepsis can all compromise microvascular flow and impair healing. Conditions such as jaundice will impair fibroblast synthetic function and immunity with a detrimental effect in most parts of the healing process. Problems with scars: Hypertrophic scars Excessive amounts of collagen within a scar. Nodules may be present histologically containing randomly arranged fibrils within and parallel fibres on the surface. The tissue itself is confined to the extent of the wound itself and is usually the result of a full thickness dermal injury. They may go on to develop contractures.

Answer 819

Where the history is strongly suggestive and the parents have a clear image or even description, most surgeons would proceed without confirmatory imaging. Herniograms and MRI would require a GA in a child of this age and are not routine. Herniotomy is the usual procedure and no mesh is used. Inguinal hernia surgery Inguinal hernias occur when the abdominal viscera protrude through the anterior abdominal wall into the inguinal canal. They may be classified as being either direct or indirect. The distinction between these two rests on their relation to Hesselbach's triangle. Boundaries of Hesselbach's Triangle Medial: Rectus abdominis Lateral: Inferior epigastric vessels Inferior: Inguinal ligament Hernias occurring within the triangle tend to be direct and those outside - indirect. Diagnosis Most cases are diagnosed clinically, a reducible swelling may be located at the level of the inguinal canal. Large hernia's may extend down into the male scrotum, these will not trans-illuminate and it is not possible to 'get above' the swelling. Cases that are unclear on examination, but suspected from the history, may be further investigated using ultrasound or by performing a herniogram. Treatment Hernias associated with few symptoms may be managed conservatively. Symptomatic hernias or those which are at risk of developing complications are usually treated surgically. First time hernias may be treated by performing an open inguinal hernia repair; the inguinal canal is opened, the hernia reduced and the defect repaired. A prosthetic mesh may be placed posterior to the cord structures to re-enforce the repair and reduce the risk of recurrence. Recurrent hernias and those which are bilateral are generally managed with a laparoscopic approach. This may be via an intra or extra peritoneal route. As in open surgery a mesh is deployed. However, it will typically lie posterior to the deep ring. Inguinal hernia in children Inguinal hernias in children are almost always of an indirect type and therefore are usually dealt with by herniotomy, rather than herniorraphy. Neonatal hernias especially in those children born prematurely are at highest risk of strangulation and should be repaired urgently. Other hernias may be repaired on an elective basis. References The UK Based National Institute of Clinical Excellence has published guidelines relating to the choice between open and laparoscopic inguinal hernia repair. Which users may find interesting: http://guidance.nice.org.uk/TA83/Guidance/pdf/English

Answer 820

The motor supply to the sternocleidomastoid is from the accessory nerve. The ansa cervicalis supplies sensory information from the muscle. Sternocleidomastoid Anatomy Origin Rounded tendon attached to upper manubrium sterni and muscular head attached to medial third of the clavicle Insertion Mastoid process of the temporal bone and lateral area of the superior nuchal line of the occipital bone Innervation Spinal part of accessory nerve and anterior rami of C2 and C3 (proprioception) Action Both: extend the head at atlanto-occipital joint and flex the cervical vertebral column. Accessory muscles of inspiration. Single: lateral flexion of neck, rotates head so face looks upward to the opposite side Sternocleidomastoid divides the anterior and posterior triangles of the neck.

Answer 821

Fistulas are more likely to heal in the absence of distal luminal obstruction Colocutaneous fistulae may occur as a result of anastomotic leakage following loop colostomy reversal. In the absence of abdominal signs a laparotomy is not necessarily required. Signs of wound sepsis may require antibiotics. Because there is not any distal obstruction (note normal pre-operative gastrograffin enema) these fistulae will usually close spontaneously. Fistulas A fistula is defined as an abnormal connection between two epithelial surfaces. There are many types ranging from Branchial fistulae in the neck to entero-cutaneous fistulae abdominally. In general surgical practice the abdominal cavity generates the majority and most of these arise from diverticular disease and Crohn's. As a general rule all fistulae will resolve spontaneously as long as there is no distal obstruction. This is particularly true of intestinal fistulae. The four types of fistulae are: Enterocutaneous These link the intestine to the skin. They may be high (>500ml) or low output (<250ml) depending upon source. Duodenal /jejunal fistulae will tend to produce high volume, electrolyte rich secretions which can lead to severe excoriation of the skin. Colo-cutaneous fistulae will tend to leak faeculent material. Both fistulae may result from the spontaneous rupture of an abscess cavity onto the skin (such as following perianal abscess drainage) or may occur as a result of iatrogenic input. In some cases it may even be surgically desirable e.g. mucous fistula following sub total colectomy for colitis. Suspect if there is excess fluid in the drain. Enteroenteric or Enterocolic This is a fistula that involves the large or small intestine. They may originate in a similar manner to enterocutaneous fistulae. A particular problem with this fistula type is that bacterial overgrowth may precipitate malabsorption syndromes. This may be particularly serious in inflammatory bowel disease. Enterovaginal Aetiology as above. Enterovesical This type of fistula goes to the bladder. These fistulas may result in frequent urinary tract infections, or the passage of gas from the urethra during urination. Management Some rules relating to fistula management: They will heal provided there is no underlying inflammatory bowel disease and no distal obstruction, so conservative measures may be the best option Where there is skin involvement, protect the overlying skin, often using a well fitted stoma bag- skin damage is difficult to treat A high output fistula may be rendered more easily managed by the use of octreotide, this will tend to reduce the volume of pancreatic secretions. Nutritional complications are common especially with high fistula (e.g. high jejunal or duodenal) these may necessitate the use of TPN to provide nutritional support together with the concomitant use of octreotide to reduce volume and protect skin. When managing perianal fistulae surgeons should avoid probing the fistula where acute inflammation is present, this almost always worsens outcomes. When perianal fistulae occur secondary to Crohn's disease the best management option is often to drain acute sepsis and maintain that drainage through the judicious use of setons whilst medical management is implemented. Always attempt to delineate the fistula anatomy, for abscesses and fistulae that have an intra abdominal source the use of barium and CT studies should show a track. For perianal fistulae surgeons should recall Goodsall's rule in relation to internal and external openings.

Answer 822

The shoulder joint is a shallow joint, hence its great mobility. However, this comes at the expense of stability. The fibrous capsule attaches to the anatomical neck superiorly and the surgical neck inferiorly Shoulder joint Shallow synovial ball and socket type of joint. It is an inherently unstable joint, but is capable to a wide range of movement. Stability is provided by muscles of the rotator cuff that pass from the scapula to insert in the greater tuberosity (all except sub scapularis-lesser tuberosity). Glenoid labrum Fibrocartilaginous rim attached to the free edge of the glenoid cavity Tendon of the long head of biceps arises from within the joint from the supraglenoid tubercle, and is fused at this point to the labrum. The long head of triceps attaches to the infraglenoid tubercle Fibrous capsule Attaches to the scapula external to the glenoid labrum and to the labrum itself (postero-superiorly) Attaches to the humerus at the level of the anatomical neck superiorly and the surgical neck inferiorly Anteriorly the capsule is in contact with the tendon of subscapularis, superiorly with the supraspinatus tendon, and posteriorly with the tendons of infraspinatus and teres minor. All these blend with the capsule towards their insertion. Two defects in the fibrous capsule; superiorly for the tendon of biceps. Anteriorly there is a defect beneath the subscapularis tendon. The inferior extension of the capsule is closely related to the axillary nerve at the surgical neck and this nerve is at risk in anteroinferior dislocations. It also means that proximally sited osteomyelitis may progress to septic arthritis. Movements and muscles Flexion Anterior part of deltoid Pectoralis major Biceps Coracobrachialis Extension Posterior deltoid Teres major Latissimus dorsi Adduction Pectoralis major Latissimus dorsi Teres major Coracobrachialis Abduction Mid deltoid Supraspinatus Medial rotation Subscapularis Anterior deltoid Teres major Latissimus dorsi Lateral rotation Posterior deltoid Infraspinatus Teres minor Important anatomical relations Anteriorly Brachial plexus Axillary artery and vein Posterior Suprascapular nerve Suprascapular vessels Inferior Axillary nerve Circumflex humeral vessels

Answer 823

The tibial nerve lies superior to the vessels in the inferior aspect of the popliteal fossa. In the upper part of the fossa the tibial nerve lies lateral to the vessels, it then passes superficial to them to lie medially. The popliteal artery is the deepest structure in the popliteal fossa. Popliteal fossa Boundaries of the popliteal fossa Laterally Biceps femoris above, lateral head of gastrocnemius and plantaris below Medially Semimembranosus and semitendinosus above, medial head of gastrocnemius below Floor Popliteal surface of the femur, posterior ligament of knee joint and popliteus muscle Roof Superficial and deep fascia Contents Popliteal artery and vein Small saphenous vein Common peroneal nerve Tibial nerve Posterior cutaneous nerve of the thigh Genicular branch of the obturator nerve Lymph nodes

Answer 824

As an artery of the anterior compartment, the anterior tibial artery is closely related to tibialis anterior. The tibialis posterior is related to it at its origin. Anterior tibial artery Begins opposite the distal border of popliteus Terminates in front of the ankle, continuing as the dorsalis pedis artery As it descends it lies on the interosseous membrane, distal part of the tibia and front of the ankle joint Passes between the tendons of extensor digitorum and extensor hallucis longus distally It is related to the deep peroneal nerve, it lies anterior to the middle third of the vessel and lateral to it in the lower third

Answer 825

The parasympathetic nerves to the pelvic organs can be encountered in left sided distal colonic resections. If divided, there are notable effects on bladder function and this can result in impaired detrusor muscle function as parasympathetic nerves are responsible for detrusor contraction. The sympathetic nerves cause detrusor relaxation. The external sphincter is not affected. This is one of the reasons that patients may develop urinary retention following colon resections. Bladder The empty bladder is contained within the pelvic cavity. It is usually a three sided pyramid. The apex of the bladder points forwards towards the symphysis pubis and the base lies immediately anterior to the rectum or vagina. Continuous with the apex is the median umbilical ligament, during development this was the site of the urachus. The inferior aspect of the bladder is retroperitoneal and the superior aspect covered by peritoneum. As the bladder distends it will tend to separate the peritoneum from the fascia of transversalis. For this reason a bladder that is distended due to acute urinary retention may be approached with a suprapubic catheter that avoids entry into the peritoneal cavity. The trigone is the least mobile part of the bladder and forms the site of the ureteric orifices and internal urethral orifice. In the empty bladder the ureteric orifices are approximately 2-3cm apart, this distance may increase to 5cm in the distended bladder. Arterial supply The superior and inferior vesical arteries provide the main blood supply to the bladder. These are branches of the internal iliac artery. Venous drainage In males the bladder is drained by the vesicoprostatic venous plexus. In females the bladder is drained by the vesicouterine venous plexus. In both sexes this venous plexus will ultimately drain to the internal iliac veins. Lymphatic drainage Lymphatic drainage is predominantly to the external iliac nodes, internal iliac and obturator nodes also form sites of bladder lymphatic drainage. Innervation Parasympathetic nerve fibres innervate the bladder from the pelvic splanchnic nerves. Sympathetic nerve fibres are derived from L1 and L2 via the hypogastric nerve plexuses. The parasympathetic nerve fibres will typically cause detrusor muscle contraction and result in voiding. The muscle of the trigone is innervated by the sympathetic nervous system. The external urethral sphincter is under conscious control. During bladder filling the rate of firing of nerve impulses to the detrusor muscle is low and receptive relaxation occurs. At higher volumes and increased intra vesical pressures the rate of neuronal firing will increase and eventually voiding will occur.

Answer 826

If the problem was related to how the surgical department is performing the surgeries, rather than stock control and the system by which the materials are used within the theater, then an operational audit would be more appropriate. For example, if the problem was that the surgical department was not using the prosthetic mesh material in the most effective manner during the surgery, such as incorrect placement or incorrect sizing, then an operational audit would be more appropriate. The audit would focus on evaluating the effectiveness and efficiency of the surgical procedures being performed, including the policies and procedures, resources, and performance metrics. The audit would identify any inefficiencies or breakdowns in the day-to-day operations that are contributing to the problem and recommend solutions to improve the effectiveness and efficiency of the surgical procedures. So, in summary, the type of audit that is most appropriate depends on the nature of the problem being investigated. If the problem is related to a breakdown in the system or technology infrastructure, then a system-based audit would be more appropriate. If the problem is related to day-to-day operations, policies, and procedures, then an operational audit would be more appropriate. Audit categories Audits may be used in a variety of clinical settings. These range from standards based audits, which will be familiar to most clinicians, through to systems based audits which focus more on the processes within an organisation. Types of audit Financial audit A historically oriented, independent evaluation performed for the purpose of attesting to the fairness, accuracy, and reliability of financial data Operational audit A future-oriented, systematic, and independent evaluation of organizational activities. Financial data may be used, but the primary sources of evidence are the operational policies and achievements related to organizational objectives. Internal controls and efficiencies may be evaluated during this type of review. Departmental review A current period analysis of administrative functions, to evaluate the adequacy of controls, safeguarding of assets, efficient use of resources, compliance with related laws, regulations and institutional policy and integrity of financial information. Standards based audit Comparison of care or passage of care against set and widely agreed standards or outcomes. Systems based audit Evaluation of processes occurring within an institution. Systems based audits are an integral part of the process of clinical governance.

Answer 827

Nausea inhibits gastric secretion via higher cerebral activity and sympathetic innervation. Gastric secretions A working knowledge of gastric secretions is important for surgery because peptic ulcers are common, surgeons frequently prescribe anti secretory drugs and because there are still patients around who will have undergone acid lowering procedures (Vagotomy) in the past. Gastric acid Is produced by the parietal cells in the stomach pH of gastric acid is around 2 with acidity being maintained by the H+/K+ ATP ase pump. As part of the process bicarbonate ions will be secreted into the surrounding vessels. Sodium and chloride ions are actively secreted from the parietal cell into the canaliculus. This sets up a negative potential across the membrane and as a result sodium and potassium ions diffuse across into the canaliculus. Carbonic anhydrase forms carbonic acid which dissociates and the hydrogen ions formed by dissociation leave the cell via the H+/K+ antiporter pump. At the same time sodium ions are actively absorbed. This leaves hydrogen and chloride ions in the canaliculus these mix and are secreted into the lumen of the oxyntic gland. Phases of gastric acid secretion There are 3 phases of gastric secretion: 1. Cephalic phase (smell / taste of food) 30% acid produced Vagal cholinergic stimulation causing secretion of HCL and gastrin release from G cells 2. Gastric phase (distension of stomach ) 60% acid produced Stomach distension/low H+/peptides causes Gastrin release 3. Intestinal phase (food in duodenum) 10% acid produced High acidity/distension/hypertonic solutions in the duodenum inhibits gastric acid secretion via enterogastrones (CCK, secretin) and neural reflexes. Regulation of gastric acid production Factors increasing production include: Vagal nerve stimulation Gastrin release Histamine release (indirectly following gastrin release) from enterchromaffin like cells Factors decreasing production include: Somatostatin (inhibits histamine release) Cholecystokinin Secretin Below is a brief summary of the major hormones involved in food digestion: Source Stimulus Actions Gastrin G cells in antrum of the stomach Distension of stomach, extrinsic nerves Inhibited by: low antral pH, somatostatin Increase HCL, pepsinogen and IF secretion, increases gastric motility, trophic effect on gastric mucosa CCK I cells in upper small intestine Partially digested proteins and triglycerides Increases secretion of enzyme-rich fluid from pancreas, contraction of gallbladder and relaxation of sphincter of Oddi, decreases gastric emptying, trophic effect on pancreatic acinar cells, induces satiety Secretin S cells in upper small intestine Acidic chyme, fatty acids Increases secretion of bicarbonate-rich fluid from pancreas and hepatic duct cells, decreases gastric acid secretion, trophic effect on pancreatic acinar cells VIP Small intestine, pancreas Neural Stimulates secretion by pancreas and intestines, inhibits acid and pepsinogen secretion Somatostatin D cells in the pancreas and stomach Fat, bile salts and glucose in the intestinal lumen Decreases acid and pepsin secretion, decreases gastrin secretion, decreases pancreatic enzyme secretion, decreases insulin and glucagon secretion inhibits trophic effects of gastrin, stimulates gastric mucous production

Answer 828

Narrowing joint space Osteoarthritis is a degenerative joint disorder, which results from a loss of hyaline cartilage in synovial joints. The first radiographic sign of osteoarthritis is non-uniform joint space narrowing. Osteopenia Osteopenia is a condition in which bone mineral density is lower than normal. Osteophytes Osteophyte formation is a radiographic sign of osteoarthritis, but it is not the first to appear. As the disease progresses, subluxation may occur and osteophytes may form. Soft tissue swelling Rest pain, stiffness and bony swelling are clinical features of osteoarthritis. Soft tissue swelling is more commonly associated with rheumatoid arthritis. Subchondral sclerosis Subchrondal sclerosis occurs as cartilage loss increases and appears as an area of increased density on the radiograph. The classic radiographic signs of osteoarthritis are joint space narrowing, subchondral sclerosis, osteophytes and subchondral cysts. Osteopenia and soft tissue swelling are often associated with rheumatoid arthritis.

Answer 829

Based on the information you provided, the most likely diagnosis is A. Transitional cell carcinoma of the bladder. This is a type of cancer that arises from the cells that line the inner surface of the bladder. It is the most common type of bladder cancer and accounts for about 90% of cases1. Some of the risk factors for transitional cell carcinoma of the bladder include: Age over 55 years Male sex Smoking Exposure to certain chemicals, such as aromatic amines, benzene, or arsenic Chronic urinary tract infections or irritation Family history of bladder cancer12 Some of the signs and symptoms of transitional cell carcinoma of the bladder include: Hematuria (blood in the urine) Dysuria (painful or difficult urination) Frequency (urinating more often than usual) Urgency (feeling a strong need to urinate) Nocturia (waking up at night to urinate) Lower back pain Pelvic pain Weight loss Fatigue12 The diagnosis of transitional cell carcinoma of the bladder is usually confirmed by: Urinalysis and urine cytology (to check for blood, infection, or abnormal cells in the urine) Cystoscopy (a procedure that uses a thin, flexible tube with a light and a camera to examine the inside of the bladder) Biopsy (a procedure that removes a small sample of tissue from the bladder for microscopic examination) Imaging tests, such as ultrasound, CT scan, or MRI (to check for the size, location, and extent of the tumor and possible spread to other organs)12 The treatment of transitional cell carcinoma of the bladder depends on the stage and grade of the cancer, as well as the patient’s age, overall health, and preferences. Some of the treatment options include: Surgery (to remove the tumor, part of the bladder, or the entire bladder) Chemotherapy (to kill cancer cells with drugs) Immunotherapy (to stimulate the body’s immune system to fight cancer cells) Radiation therapy (to destroy cancer cells with high-energy rays) Intravesical therapy (to deliver drugs directly into the bladder through a catheter)

Answer 830

The correct answer is B. Anterior talofibular ligament. This is the most frequently damaged ligament in the ankle, especially when the foot is forcefully inverted12. The anterior talofibular ligament connects the talus bone to the fibula bone on the outer side of the ankle

Answer 831

Vena cava T8 (eight letters) Oesophagus T10 (ten letters) Aortic hiatus T12 (twelve letters) The dura terminates at S2. The spinal cord terminates at L1, which is why it's safe to undertake an LP at L4/5. Levels Transpyloric plane Level of the body of L1 Pylorus stomach Left kidney hilum (L1- left one!) Fundus of the gallbladder Neck of pancreas Duodenojejunal flexure Superior mesenteric artery Portal vein Left and right colic flexure Root of the transverse mesocolon 2nd part of the duodenum Upper part of conus medullaris Spleen Can be identified by asking the supine patient to sit up without using their arms. The plane is located where the lateral border of the rectus muscle crosses the costal margin. Anatomical planes Subcostal plane Lowest margin of 10th costal cartilage Intercristal plane Level of body L4 (highest point of iliac crest) Intertubercular plane Level of body L5 Common level landmarks Inferior mesenteric artery L3 Bifurcation of aorta into common iliac arteries L4 Formation of IVC L5 (union of common iliac veins) Diaphragm apertures Vena cava T8 Oesophagus T10 Aortic hiatus T12

Answer 832

Pseudocholinesterase Neuromuscular blocking drugs These drugs work by preventing acetylcholine interacting with the post synaptic (nicotinic) receptors on the motor end plate of skeletal muscle. They are described as being either depolarising or non depolarising according to their mode of action. Depolarising neuromuscular blocking drugs Suxamethonium is the only commonly used drug in this category. Following injection there is a brief period of muscular fasciculation as the membrane is depolarised followed by paralysis. Recovery occurs spontaneously as the suxamethonium is hydrolysed by the enzyme plasma pseudocholinesterase. This process typically takes 4-6 minutes. Suxamethonium has a number of important side effects which include malignant hyperpyrexia in susceptible patients, increased intra ocular pressure, prolonged apoea in those with pseudocholinesterase deficiency, a rise in serum potassium (which is most marked in burns and crush injury patients). Pseudocholinesterase deficiency Approximately 50 in 1000 will have slightly reduced enzyme activity and the paralysis effects may last for up to 20 minutes. In those with true and complete enzyme deficiency the apnoea can lasts for up to 2 hours, the incidence of this is <1 per 1000. Patients who display an enzyme lack will require prolonged ventillatory support subsequently and should be warned of this. This should then be clearly recorded in patient notes. Non depolarising neuromuscular blocking drugs These drugs compete with acetylcholine and block its access at the post synaptic receptor sites on the muscle. They do not cause depolarisation. They have a slower duration of onset and a longer duration of action than suxamethonium. In many cases an anticholinesterase may be administered to hasten recovery. This results in an increase in acetylcholine at the receptor site which then competes with the paralysing drug at the receptor site. Reversal drugs are not administered until there is some evidence of returning neuromuscular function to avoid rebound paralysis following recovery from anaesthesia. An antimuscarinic drug is used concomitantly with reversal agents to avoid the parsympathetic surge that would otherwise accompany a rise in AcH levels at the parasympathetic receptors with associated bradycardia and salivation. Neostigmine is the reversal agent in common use and it is often administered with atropine or glycopyrrolate to avoid the adverse effects outline above.

Answer 833

The increased permeability allows the exudation of plasma proteins. Acute inflammation Inflammation is the reaction of the tissue elements to injury. Vascular changes occur, resulting in the generation of a protein rich exudate. So long as the injury does not totally destroy the existing tissue architecture, the episode may resolve with restoration of original tissue architecture. Vascular changes Vasodilation occurs and persists throughout the inflammatory phase. Inflammatory cells exit the circulation at the site of injury. The equilibrium that balances Starlings forces within capillary beds is disrupted and a protein rich exudate will form as the vessel walls also become more permeable to proteins. The high fibrinogen content of the fluid may form a fibrin clot. This has several important immunomodulatory functions. Sequelae Resolution Typically occurs with minimal initial injury Stimulus removed and normal tissue architecture results Organisation Delayed removal of exudate Tissues undergo organisation and usually fibrosis Suppuration Typically formation of an abscess or an empyema Sequestration of large quantities of dead neutrophils Progression to chronic inflammation Coupled inflammatory and reparative activities Usually occurs when initial infection or suppuration has been inadequately managed Causes Infections e.g. Viruses, exotoxins or endotoxins released by bacteria Chemical agents Physical agents e.g. Trauma Hypersensitivity reactions Tissue necrosis Presence of neutrophil polymorphs is a histological diagnostic feature of acute inflammation

Answer 834

Stylohyoid is innervated by the facial nerve. Trigeminal nerve The trigeminal nerve is the main sensory nerve of the head. In addition to its major sensory role, it also innervates the muscles of mastication. Distribution of the trigeminal nerve Sensory Scalp Face Oral cavity (and teeth) Nose and sinuses Dura mater Motor Muscles of mastication Mylohyoid Anterior belly of digastric Tensor tympani Tensor palati Autonomic connections (ganglia) Ciliary Sphenopalatine Otic Submandibular Path Originates at the pons Sensory root forms the large, crescentic trigeminal ganglion within Meckel's cave, and contains the cell bodies of incoming sensory nerve fibres. Here the 3 branches exit. The motor root cell bodies are in the pons and the motor fibres are distributed via the mandibular nerve. The motor root is not part of the trigeminal ganglion. Branches of the trigeminal nerve Ophthalmic nerve Sensory only Maxillary nerve Sensory only Mandibular nerve Sensory and motor Sensory Ophthalmic Exits skull via the superior orbital fissure Sensation of: scalp and forehead, the upper eyelid, the conjunctiva and cornea of the eye, the nose (including the tip of the nose, except alae nasi), the nasal mucosa, the frontal sinuses, and parts of the meninges (the dura and blood vessels). Maxillary nerve Exit skull via the foramen rotundum Sensation: lower eyelid and cheek, the nares and upper lip, the upper teeth and gums, the nasal mucosa, the palate and roof of the pharynx, the maxillary, ethmoid and sphenoid sinuses, and parts of the meninges. Mandibular nerve Exit skull via the foramen ovale Sensation: lower lip, the lower teeth and gums, the chin and jaw (except the angle of the jaw), parts of the external ear, and parts of the meninges. Motor Distributed via the mandibular nerve. The following muscles of mastication are innervated: Masseter Temporalis Medial pterygoid Lateral pterygoid Other muscles innervated include: Tensor veli palatini Mylohyoid Anterior belly of digastric Tensor tympani

Answer 835

The retromandibular vein is formed from the union of the maxillary and superficial temporal veins. Retromandibular vein Formed by a union of the maxillary vein and superficial temporal vein It descends through the parotid gland and bifurcates within it The anterior division passes forwards to join the facial vein, the posterior division is one of the tributaries of the external jugular vein

Answer 836

Unilateral isolated cleft lip represents a failure of nasolabial ring fusion. It is not related to branchial arch fusion. Arch disorders have a far more profound phenotype and malformation sequences. Cleft lip and palate Cleft lip and palate are the most common congenital deformity affecting the orofacial structures. Whilst they may be an isolated developmental malformation they are also a recognised component of more than 200 birth defects. The incidence is as high as 1 in 600 live births. The commonest variants are: Isolated cleft lip (15%) Isolated cleft palate (40%) Combined cleft lip and palate (45%) The aetiology of the disorder is multifactorial; both genetic (affected first degree relative increases risk) and environmental factors play a role. Cleft lip Cleft lip occurs as a result of disruption of the muscles of the upper lip and nasolabial region. These muscles comprise a chain of muscles viz; nasolabial, bilabial and labiomental. Defects may be unilateral or bilateral. Cleft palate The primary palate consists of all anatomical structures anterior to the incisive foramen. The secondary palate lies more posteriorly and is sub divided into the hard and soft palate. Cleft palate occurs as a result of non fusion of the two palatine shelves. Both hard and soft palate may be involved. Complete cases are associated with complete separation of the nasal septum and vomer from the palatine processes. Treatment Surgical reconstruction is the mainstay of management. The procedures are planned according to the extent of malformation and child age. Simple defects are managed as a single procedure. Complex malformations are usually corrected in stages. Affected individuals have a higher incidence of hearing and speech problems.

Answer 837

Most patients with Sjogrens present in the post menopausal years. Multi system involvement is common. Parotid gland clinical Benign neoplasms Up to 80% of all salivary gland tumours occur in the parotid gland and up to 80% of these are benign. There is no consistent correlation between the rate of growth and the malignant potential of the lesion. However, benign tumours should not invade structures such as the facial nerve. With the exception of Warthins tumours, they are commoner in women than men. The median age of developing a lesion is in the 5th decade of life. Benign tumour types Tumour type Features Benign pleomorphic adenoma or benign mixed tumor Most common parotid neoplasm (80%) Proliferation of epithelial and myoepithelial cells of the ducts and an increase in stromal components Slow growing, lobular, and not well encapsulated Recurrence rate of 1-5% with appropriate excision (parotidectomy) Recurrence possibly secondary to capsular disruption during surgery Malignant degeneration occurring in 2-10% of adenomas observed for long periods, with carcinoma ex-pleomorphic adenoma occurring most frequently as adenocarcinoma Warthin tumor (papillary cystadenoma lymphoma or adenolymphoma) Second most common benign parotid tumor (5%) Most common bilateral benign neoplasm of the parotid Marked male as compared to female predominance Occurs later in life (sixth and seventh decades) Presents as a lymphocytic infiltrate and cystic epithelial proliferation May represent heterotopic salivary gland epithelial tissue trapped within intraparotid lymph nodes Incidence of bilaterality and multicentricity of 10% Malignant transformation rare (almost unheard of) Monomorphic adenoma Account for less than 5% of tumours Slow growing Consist of only one morphological cell type (hence term mono) Include; basal cell adenoma, canalicular adenoma, oncocytoma, myoepitheliomas Haemangioma Should be considered in the differential of a parotid mass in a child Accounts for 90% of parotid tumours in children less than 1 year of age Hypervascular on imaging Spontaneous regression may occur and malignant transformation is almost unheard of Malignant salivary gland tumours Types of malignancy Mucoepidermoid carcinoma 30% of all parotid malignancies Usually low potential for local invasiveness and metastasis (depends mainly on grade) Adenoid cystic carcinoma Unpredictable growth pattern Tendency for perineural spread Nerve growth may display skip lesions resulting in incomplete excision Distant metastasis more common (visceral rather than nodal spread) 5 year survival 35% Mixed tumours Often a malignancy occurring in a previously benign parotid lesion Acinic cell carcinoma Intermediate grade malignancy May show perineural invasion Low potential for distant metastasis 5 year survival 80% Adenocarcinoma Develops from secretory portion of gland Risk of regional nodal and distant metastasis 5 year survival depends upon stage at presentation, may be up to 75% with small lesions with no nodal involvement Lymphoma Large rubbery lesion, may occur in association with Warthins tumours Diagnosis should be based on regional nodal biopsy rather than parotid resection Treatment is with chemotherapy (and radiotherapy) Diagnostic evaluation Plain x-rays may be used to exclude calculi Sialography may be used to delineate ductal anatomy FNAC is used in most cases Superficial parotidectomy may be either diagnostic or therapeutic depending upon the nature of the lesion Where malignancy is suspected the primary approach should be definitive resection rather than excisional biopsy CT/ MRI may be used in cases of malignancy for staging primary disease Treatment For nearly all lesions this consists of surgical resection, for benign disease this will usually consist of a superficial parotidectomy. For malignant disease a radical or extended radical parotidectomy is performed. The facial nerve is included in the resection if involved. The need for neck dissection is determined by the potential for nodal involvement. Other parotid disorders HIV infection Lymphoepithelial cysts associated with HIV occur almost exclusively in the parotid Typically presents as bilateral, multicystic, symmetrical swelling Risk of malignant transformation is low and management usually conservative Sjogren syndrome Autoimmune disorder characterised by parotid enlargement, xerostomia and keratoconjunctivitis sicca 90% of cases occur in females Second most common connective tissue disorder Bilateral, non tender enlargement of the gland is usual Histologically, the usual findings are of a lymphocytic infiltrate in acinar units and epimyoepithelial islands surrounded by lymphoid stroma Treatment is supportive There is an increased risk of subsequent lymphoma Sarcoid Parotid involvement occurs in 6% of patients with sarcoid Bilateral in most cases Gland is not tender Xerostomia may occur Management of isolated parotid disease is usually conservative

Answer 838

The middle finger has no attachment of the palmar interosseous. Note that there are 4 palmar interossei. The first is a small slip of muscle which arises from the ulnar side of the base of the first metacarpal and passes between the head of the first dorsal interosseous and the oblique head of adductor pollicis to insert into the ulnar base of the of the proximal phalanx of the thumb. The second arises from the ulnar side of the body of the second metacarpal and is inserted into the ulnar side of the extensor hood of the index. The third and fourth palmar interossei arise from the radial sides of the bodies of the 4th and 5th metacarpals respectively and insert into the radial sides of the extensor hoods of the ring and little fingers. Hand Anatomy of the hand Bones 8 Carpal bones 5 Metacarpals 14 phalanges Intrinsic Muscles 8 Interossei - Supplied by ulnar nerve 4 palmar-adduct fingers 4 dorsal- abduct fingers Intrinsic muscles Lumbricals Flex MCPJ and extend the IPJ. Origin deep flexor tendon and insertion dorsal extensor hood mechanism. Innervation: 1st and 2nd- median nerve, 3rd and 4th- deep branch of the ulnar nerve. Thenar eminence Abductor pollicis brevis Opponens pollicis Flexor pollicis brevis Hypothenar eminence Opponens digiti minimi Flexor digiti minimi brevis Abductor digiti minimi Fascia and compartments of the palm The fascia of the palm is continuous with the antebrachial fascia and the fascia of the dorsum of the hand. The palmar fascia is thin over the thenar and hypothenar eminences. In contrast, the central palmar fascia is relatively thick. The palmar aponeurosis covers the soft tissues and overlies the flexor tendons. The apex of the palmar aponeurosis is continuous with the flexor retinaculum and the palmaris longus tendon. Distally, it forms four longitudinal digital bands that attach to the bases of the proximal phalanges, blending with the fibrous digital sheaths. A medial fibrous septum extends deeply from the medial border of the palmar aponeurosis to the 5th metacarpal. Lying medial to this are the hypothenar muscles. In a similar fashion, a lateral fibrous septum extends deeply from the lateral border of the palmar aponeurosis to the 3rd metacarpal. The thenar compartment lies lateral to this area. Lying between the thenar and hypothenar compartments is the central compartment. It contains the flexor tendons and their sheaths, the lumbricals, the superficial palmar arterial arch and the digital vessels and nerves. The deepest muscular plane is the adductor compartment, which contains adductor pollicis. Short muscles of the hand These comprise the lumbricals and interossei. The four slender lumbrical muscles flex the fingers at the metacarpophalangeal joints and extend the interphalangeal joint. The four dorsal interossei are located between the metacarpals and the four palmar interossei lie on the palmar surface of the metacarpals in the interosseous compartment of the hand. Long flexor tendons and sheaths in the hand The tendons of FDS and FDP enter the common flexor sheath deep to the flexor retinaculum. The tendons enter the central compartment of the hand and fan out to their respective digital synovial sheaths. Near the base of the proximal phalanx, the tendon of FDS splits to permit the passage of FDP. The FDP tendons are attached to the margins of the anterior aspect of the base of the distal phalanx. The fibrous digital sheaths contain the flexor tendons and their synovial sheaths. These extend from the heads of the metacarpals to the base of the distal phalanges. Palmar Interossei Note that there are 4 palmar interossei. The first is a small slip of muscle which arises from the ulnar side of the base of the first metacarpal and passes between the head of the first dorsal interosseous and the oblique head of adductor pollicis to insert into the ulnar base of the of the proximal phalanx of the thumb. The second arises from the ulnar side of the body of the second metacarpal and is inserted into the ulnar side of the extensor hood of the index. The third and fourth palmar interossei arise from the radial sides of the bodies of the 4th and 5th metacarpals respectively and insert into the radial sides of the extensor hoods of the ring and little fingers.

Answer 839

Nocturnal diarrhea and incontinence is a key feature in the history and is strongly suggestive of a diagnosis of IBD. More benign IBS presentations seldom have nocturnal events or a short history. Rectal bleeding Rectal bleeding is a common cause for patients to be referred to the surgical clinic. In the clinical history it is useful to try and localise the anatomical source of the blood. Bright red blood is usually of rectal anal canal origin, whilst dark red blood is more suggestive of a proximally sited bleeding source. Blood which has entered the GI tract from a gastro-duodenal source will typically resemble malaena due to the effects of the digestive enzymes on the blood itself. In the table below we give some typical bleeding scenarios together with physical examination findings and causation. Cause Type of bleeding Features in history Examination findings Fissure in ano Bright red rectal bleeding Painful bleeding that occurs post defecation in small volumes. Usually antecedent features of constipation Muco-epithelial defect usually in the midline posteriorly (anterior fissures more likely to be due to underlying disease) Haemorroids Bright red rectal bleeding Post defecation bleeding noted both on toilet paper and drips into pan. May be alteration of bowel habit and history of straining. No blood mixed with stool. No local pain. Normal colon and rectum. Proctoscopy may show internal haemorrhoids. Internal haemorrhoids are usually impalpable. Crohns disease Bright red or mixed blood Bleeding that is accompanied by other symptoms such as altered bowel habit, malaise, history of fissures (especially anterior) and abscesses. Perineal inspection may show fissures or fistulae. Proctoscopy may demonstrate indurated mucosa and possibly strictures. Skip lesions may be noted at colonoscopy. Ulcerative colitis Bright red bleeding often mixed with stool Diarrhoea, weight loss, nocturnal incontinence, passage of mucous PR. Proctitis is the most marked finding. Peri anal disease is usually absent. Colonoscopy will show continuous mucosal lesion. Rectal cancer Bright red blood mixed volumes Alteration of bowel habit. Tenesmus may be present. Symptoms of metastatic disease. Usually obvious mucosal abnormality. Lesion may be fixed or mobile depending upon disease extent. Surrounding mucosa often normal, although polyps may be present. Image showing a fissure in ano. Typically these are located posteriorly and in the midline. Fissures at other sites may be associated with underlying disease. Investigation All patients presenting with rectal bleeding require digital rectal examination and procto-sigmoidoscopy as a minimal baseline. Remember that haemorrhoids are typically impalpable and to attribute bleeding to these in the absence of accurate internal inspection is unsatisfactory. In young patients with no other concerning features in the history a carefully performed sigmoidoscopy that demonstrates clear haemorrhoidal disease may be sufficient. If clear views cannot be obtained then patients require bowel preparation with an enema and a flexible sigmoidscopy performed. In those presenting with features of altered bowel habit or suspicion of inflammatory bowel disease a colonoscopy is the best test. Patients with excessive pain who are suspected of having a fissure may require an examination under general or local anaesthesia. In young patients with external stigmata of fissure and a compatible history it is acceptable to treat medically and defer internal examination until the fissure is healed. If the fissure fails to heal then internal examination becomes necessary along the lines suggested above to exclude internal disease. Special tests In patients with a malignancy of the rectum the staging investigations comprise an MRI of the rectum to identify circumferential resection margin compromise and to identify mesorectal nodal disease. In addition to this CT scanning of the chest abdomen and pelvis is necessary to stage for more distant disease. Some centres will still stage the mesorectum with endo rectal ultrasound but this is becoming far less common. Patients with fissure in ano who are being considered for surgical sphincterotomy and are females who have an obstetric history should probably have ano rectal manometry testing performed together with endo anal ultrasound. As this service is not universally available it is not mandatory but in the absence of such information there are continence issues that may arise following sphincterotomy. Management Disease Management Fissure in ano GTN ointment 0.2% or diltiazem cream applied topically is the usual first line treatment. Botulinum toxin for those who fail to respond. Internal sphincterotomy for those who fail with botox, can be considered earlier in males. Haemorroids Lifestyle advice, for small internal haemorrhoids can consider injection sclerotherapy or rubber band ligation. For external haemorrhoids consider haemorrhoidectomy. Modern options include HALO procedure and stapled haemorrhoidectomy. Inflammatory bowel disease Medical management- although surgery may be needed for fistulating Crohns (setons). Rectal cancer Anterior resection or abdomino-perineal excision of the colon and rectum. Total mesorectal excision is now standard of care. Most resections below the peritoneal reflection will require defunctioning ileostomy. Most patients will require preoperative radiotherapy.

Answer 840

It is innervated by the superficial branch of the femoral nerve. It is a component of the pes anserinus. Sartorius - Longest strap muscle in the body Most superficial muscle in the anterior compartment of the thigh Origin Anterior superior iliac spine Insertion Medial surface of the of the body of the tibia (upper part). It inserts anterior to gracilis and semitendinosus Nerve Supply Femoral nerve (L2,3 -root values for sartorius) Action Flexor of the hip and knee, slight abducts the thigh and rotates it laterally It assists with medial rotation of the tibia on the femur. For example it would play a pivotal role in placing the right heel onto the left knee ( and vice versa) Important relations The middle third of this muscle, and its strong underlying fascia forms the roof of the adductor canal , in which lie the femoral vessels, the saphenous nerve and the nerve to vastus medialis.

Answer 841

CD20 is a B cell lymphoma marker and is useful in histochemical analysis of biopsies. Even without knowing that, it is still possible to approach questions like this with a logical exclusion approach. Follicular lesions tend not to have lymphatic involvement and the same is true of Hashimotos thyroiditis. Papillary thyroid cancers do remain a possible tumour as they have lymphatic involvement (its for this that knowledge of the CD20 is required). Thyroid malignancy Papillary carcinoma Commonest sub-type Accurately diagnosed on fine needle aspiration cytology Histologically, they may demonstrate psammoma bodies (areas of calcification) and so called 'orphan Annie' nuclei They typically metastasise via the lymphatics and thus laterally located apparently ectopic thyroid tissue is usually a metastasis from a well differentiated papillary carcinoma Follicular carcinoma Are less common than papillary lesions Like papillary tumours, they may present as a discrete nodule. Although they appear to be well encapsulated macroscopically there is invasion on microscopic evaluation Lymph node metastases are uncommon and these tumours tend to spread haematogenously. This translates into a higher mortality rate Follicular lesions cannot be accurately diagnosed on fine needle aspiration cytology and thus all follicular FNA's (THY 3f) will require at least a hemi thyroidectomy Anaplastic carcinoma Less common and tend to occur in elderly females Disease is usually advanced at presentation and often only palliative decompression and radiotherapy can be offered. Medullary carcinoma These are tumours of the parafollicular cells ( C Cells) and are of neural crest origin. The serum calcitonin may be elevated which is of use when monitoring for recurrence. They may be familial and occur as part of the MEN -2A disease spectrum. Spread may be either lymphatic or haematogenous and as these tumours are not derived primarily from thyroid cells they are not responsive to radioiodine. Lymphoma These respond well to combined chemoradiotherapy Radical surgery is unnecessary once the disease has been diagnosed on biopsy material. Such biopsy material is not generated by an FNA and thus a core biopsy has to be obtained (with care!).

Answer 842

A bisphosphonate, calcium and vitamin D supplementation should be given to all patients aged over 75 years after having a fracture. A DEXA scan is only needed of the patient is aged below 75 years. Hormone replacement therapy has been shown to reduce vertebral and non vertebral fractures, however the risks of cardiovascular disease and breast malignancy make this a less favourable option. Osteoporosis: secondary prevention NICE guidelines were updated in 2008 on the secondary prevention of osteoporotic fractures in postmenopausal women. Key points include Treatment is indicated following osteoporotic fragility fractures in postmenopausal women who are confirmed to have osteoporosis (a T-score of - 2.5 SD or below). In women aged 75 years or older, a DEXA scan may not be required if the responsible clinician considers it to be clinically inappropriate or unfeasible Vitamin D and calcium supplementation should be offered to all women unless the clinician is confident they have adequate calcium intake and are vitamin D replete Alendronate is first-line Around 25% of patients cannot tolerate alendronate, usually due to upper gastrointestinal problems. These patients should be offered risedronate or etidronate (see treatment criteria below) Strontium ranelate and raloxifene are recommended if patients cannot tolerate bisphosphonates (see treatment criteria below) Supplementary notes on treatment Bisphosphonates Alendronate, risedronate and etidronate are all licensed for the prevention and treatment of post-menopausal and glucocorticoid-induced osteoporosis All three have been shown to reduce the risk of both vertebral and non-vertebral fractures although alendronate, risedronate may be superior to etidronate in preventing hip fractures Ibandronate is a once-monthly oral bisphosphonate Vitamin D and calcium Poor evidence base to suggest reduced fracture rates in the general population at risk of osteoporotic fractures - may reduce rates in frail, housebound patients Raloxifene - selective oestrogen receptor modulator (SERM) Has been shown to prevent bone loss and to reduce the risk of vertebral fractures, but has not yet been shown to reduce the risk of non-vertebral fractures Has been shown to increase bone density in the spine and proximal femur May worsen menopausal symptoms Increased risk of thromboembolic events May decrease risk of breast cancer Strontium ranelate 'Dual action bone agent' - increases deposition of new bone by osteoblasts and reduces the resorption of bone by osteoclasts Strong evidence base, may be second-line treatment in near future Increased risk of thromboembolic events

Answer 843

The pretracheal fascia encloses the thyroid and is unyielding. Therefore tense haematomas can develop Thyroid gland Right and left lobes connected by isthmus Surrounded by sheath from pretracheal layer of deep fascia Apex: Lamina of thyroid cartilage Base: 4th-5th tracheal ring Pyramidal lobe: from isthmus May be attached to foramen caecum at the base of the tongue Relations Anteromedially Sternothyroid Superior belly of omohyoid Sternohyoid Anterior aspect of sternocleidomastoid Posterolaterally Carotid sheath Medially Larynx Trachea Pharynx Oesophagus Cricothyroid muscle External laryngeal nerve (near superior thyroid artery) Recurrent laryngeal nerve (near inferior thyroid artery) Posterior Parathyroid glands Anastomosis of superior and inferior thyroid arteries Isthmus Anteriorly: Sternothyroids, sternohyoids, anterior jugular veins Posteriorly: 2nd, 3rd, 4th tracheal rings (attached via Ligament of Berry) Blood Supply Arterial Superior thyroid artery (1st branch of external carotid) Inferior thyroid artery (from thyrocervical trunk) Thyroidea ima (in 10% of population -from brachiocephalic artery or aorta) Venous Superior and middle thyroid veins - into the IJV Inferior thyroid vein - into the brachiocephalic veins

Answer 844

The arterial supply to the prostate gland is from the inferior vesical artery, it is a branch of the prostatovesical artery. The prostatovesical artery usually arises from the internal pudendal and inferior gluteal arterial branches of the internal iliac artery. Prostate gland The prostate gland is approximately the shape and size of a walnut and is located inferior to the bladder. It is separated from the rectum by Denonvilliers fascia and its blood supply is derived from the internal iliac vessels (via inferior vesical artery). The internal sphincter lies at the apex of the gland and may be damaged during prostatic surgery, affected individuals may complain of retrograde ejaculation. Summary of prostate gland Arterial supply Inferior vesical artery (from internal iliac) Venous drainage Prostatic venous plexus (to paravertebral veins) Lymphatic drainage Internal iliac nodes Innervation Inferior hypogastric plexus Dimensions Transverse diameter (4cm) AP diameter (2cm) Height (3cm) Lobes Posterior lobe: posterior to urethra Median lobe: posterior to urethra, in between ejaculatory ducts Lateral lobes x 2 Isthmus Zones Peripheral zone: subcapsular portion of posterior prostate. Most prostate cancers are here Central zone Transition zone Stroma Relations Anterior Pubic symphysis Prostatic venous plexus Posterior Denonvilliers fascia Rectum Ejaculatory ducts Lateral Venous plexus (lies on prostate) Levator ani (immediately below the puboprostatic ligaments)

Answer 845

Hyperacute graft rejection is due to pre-existent antibodies to HLA antigens and is therefore IgG mediated Renal transplant:HLA typing and graft failure The human leucocyte antigen (HLA) system is the name given to the major histocompatibility complex (MHC) in humans. It is coded for on chromosome 6. Some basic points on the HLA system Class 1 antigens include A, B and C. Class 2 antigens include DP,DQ and DR When HLA matching for a renal transplant the relative importance of the HLA antigens are as follows DR > B > A Graft survival 1 year = 90%, 10 years = 60% for cadaveric transplants 1 year = 95%, 10 years = 70% for living-donor transplants Post-op problems ATN of graft Vascular thrombosis Urine leakage UTI Hyperacute acute rejection Due to antibodies against donor HLA type 1 antigens Rarely seen due to HLA matching Acute graft failure (< 6 months) Usually due to mismatched HLA Other causes include cytomegalovirus infection Management: give steroids, if resistant use monoclonal antibodies Causes of chronic graft failure (> 6 months) Chronic allograft nephropathy Ureteric obstruction Recurrence of original renal disease (MCGN > IgA > FSGS)

Answer 846

A score of this value is unlikely to be reached with a grade 1 tumour and a size of 2cm. Therefore lymph node metastasis are definitely present. In addition since the maximal score for lymph node metastasis is 3 the tumour is likely be of a higher grade (see below). The Nottingham Prognostic Index provides no information about oestrogen receptor status or the presence or absence of vascular invasion. Nottingham prognostic index The Nottingham Prognostic Index can be used to give an indication of survival following breast cancer surgery. In this system, the tumour size is weighted less heavily than other major prognostic parameters. Calculation of NPI Tumour Size x 0.2 + Lymph node score(From table below)+Grade score(From table below). Score Lymph nodes involved Grade 1 0 1 2 1-3 2 3 >3 3 Prognosis Score Percentage 5 year survival 2.0 to 2.4 93% 2.5 to 3.4 85% 3.5 to 5.4 70% >5.4 50% This data was originally published in 1992. It should be emphasised that other factors such as vascular invasion and receptor status also impact on survival and are not included in this data and account for varying prognoses often cited in the literature. Reference Galea, M.H., et al., The Nottingham Prognostic Index in primary breast cancer. Breast Cancer Res Treat, 1992. 22(3): p. 207-19.

Answer 847

A combination of thromboembolism and coagulation issues in a young woman should raise the possibility of antiphospholipid syndrome. Other features may include foetal loss, venous and arterial thrombosis and thrombocytopenia. A Lupus anticoagulant may be present and the APTT is prolonged. Abnormal coagulation Cause Factors affected Heparin Prevents activation factors 2,9,10,11 Warfarin Affects synthesis of factors 2,7,9,10 DIC Factors 1,2,5,8,11 Liver disease Factors 1,2,5,7,9,10,11 Interpretation blood clotting test results Disorder APTT PT Bleeding time Haemophilia Increased Normal Normal von Willebrand's disease Increased Normal Increased Vitamin K deficiency Increased Increased Normal

Answer 848

The hypogastric plexuses provide autonomic control of the bladder. However, voluntary control of the urethral sphincter is provided by the pudendal nerve. Pudendal nerve The pudendal nerve arises from nerve roots S2, S3 and S4 and exits the pelvis through the greater sciatic foramen. It re-enters the perineum through the lesser sciatic foramen. It travels inferior to give innervation to the anal sphincters and external urethral sphincter. It also provides cutaneous innervation to the region of perineum surrounding the anus and posterior vulva. Traction and compression of the pudendal nerve by the foetus in late pregnancy may result in late onset pudendal neuropathy which may be part of the process involved in the development of faecal incontinence.

Answer 849

Nutrition Monitoring-NICE guidelines Weight: daily if fluid balance concerns, otherwise weekly reducing to monthly BMI: at start of feeding and then monthly If weight cannot be obtained: monthly mid arm circumference or triceps skin fold thickness Daily electrolytes until levels stable. Then once or twice a week. Weekly glucose, phosphate, magnesium, LFTs, Ca, albumin, FBC, MCV levels if stable 2-4 weekly Zn, Folate, B12 and Cu levels if stable 3-6 monthly iron and ferritin levels, manganese (if on home parenteral regime) 6 monthly vitamin D Bone densitometry initially on starting home parenteral nutrition then every 2 years

Answer 850

The cephalic vein is a favored vessel for arteriovenous fistula formation and should be preserved in patients with end stage renal failure The cephalic vein penetrates the clavipectoral fascia (but not the pectoralis major) prior to terminating in the axillary vein. Cephalic vein Path Dorsal venous arch drains laterally into the cephalic vein Crosses the anatomical snuffbox and travels laterally up the arm At the antecubital fossa connected to the basilic vein by the median cubital vein Pierces deep fascia of deltopectoral groove to join axillary vein

Answer 851

The pain or discomfort of IBS is typically migratory and variable in intensity. Pain at a fixed site is suggestive of malignancy. Abdominal bloating is an extremely common feature. Irritable bowel syndrome The diagnosis of irritable bowel syndrome is made according to the ROME IV diagnostic criteria which state: Recurrent abdominal pain or discomfort at 3 days per month for the past 3 months associated with two or more of the following: Improvement with defecation. Onset associated with a change in the frequency of stool. Onset associated with a change in the form of the stool. Features such as lethargy, nausea, backache and bladder symptoms may also support the diagnosis Red flag features should be inquired about: Rectal bleeding Unexplained/unintentional weight loss Family history of bowel or ovarian cancer Onset after 60 years of age Suggested investigations are: Full blood count ESR/CRP Coeliac disease screen (tissue transglutaminase antibodies) Colonoscopy (if worrying symptoms, positive family history) Thyroid function tests Glucose (ensure not diabetic) The NICE criteria state that blood tests alone will suffice in people fulfilling the diagnostic criteria. We would point out that luminal colonic studies should be considered early in patients with altered bowel habit referred to hospital and a diagnosis of IBS should still be largely one of exclusion. Treatment Usually reduce fibre intake. Tailored prescriptions of laxatives or loperamide according to clinical picture. Dietary modification (caffeine avoidance, less carbonated drinks). Consider low dose tricyclic antidepressants if pain is a dominant symptom. Biofeedback may help.

Answer 852

The common iliac veins fuse with the IVC at L5. Inferior vena cava Origin L5 Path Left and right common iliac veins merge to form the IVC. Passes right of midline Paired segmental lumbar veins drain into the IVC throughout its length The right gonadal vein empties directly into the cava and the left gonadal vein generally empties into the left renal vein. The next major veins are the renal veins and the hepatic veins Pierces the central tendon of diaphragm at T8 Right atrium Relations Anteriorly Small bowel, first and third part of duodenum, head of pancreas, liver and bile duct, right common iliac artery, right gonadal artery Posteriorly Right renal artery, right psoas, right sympathetic chain, coeliac ganglion Levels Level Vein T8 Hepatic vein, inferior phrenic vein, pierces diaphragm L1 Right suprarenal vein, renal vein L2 Gonadal vein L1-5 Lumbar veins L5 Common iliac vein, formation of IVC

Answer 853

Patients with malabsorption may develop magnesium deficiency, although her TPN feeds may have contained magnesium it may not have been sufficient to correct her losses. Sodium, phosphate and potassium would not have this effect on serum calcium. Combined deficiency of magnesium and calcium Magnesium is required for both PTH secretion and its action on target tissues. Hypomagnesaemia may both cause hypocalcaemia and render patients unresponsive to treatment with calcium and vitamin D supplementation. Magnesium is the fourth most abundant cation in the body. The body contains 1000mmol, with half contained in bone and the remainder in muscle, soft tissues and extracellular fluid. There is no one specific hormonal control of magnesium and various hormones including PTH and aldosterone affect the renal handling of magnesium. Magnesium and calcium interact at a cellular level also and as a result decreased magnesium will tend to affect the permeability of cellular membranes to calcium, resulting in hyperexcitability.

Answer 854

Mnemonic for lower sternal angle: Red, white, blue and air 2 Red- arch of aorta White- the thoracic duct crosses at the midline Bue- azygous joins the svc Air- tracheal bifurcation 2- costal cartilage of the second rib At the level of the Angle of Louis (Manubriosternal angle), is the surface marking for the aortic arch. The oesophagus is posteriorly located and at less risk. Sternal angle Anatomical structures at the level of the manubrium and upper sternum Upper part of the manubrium Left brachiocephalic vein Brachiocephalic artery Left common carotid Left subclavian artery Lower part of the manubrium/ manubrio-sternal angle Costal cartilages of the 2nd ribs Transition point between superior and inferior mediastinum Arch of the aorta Tracheal bifurcation Union of the azygos vein and superior vena cava The thoracic duct crosses to the midline

Answer 855

Neutrophils are the main cells of acute inflammation, important action against gram -ve and +ve bacteria Appearance of segmented nucleus and granulated cytoplasm Have a lifespan of 1-3 days (shorter when consumed during septic process, though 9 hours is unusual) Actions include: movement, opsonise microorganisms, phagocytosis & intracellular killing of microorganisms via aerobic (produce HYDROGEN PEROXIDE) & anaerobic mechanisms. Neutrophil disorders include chronic granulomatous diseases: rare AIDS associated with T cell deficiency Acute inflammation Inflammation is the reaction of the tissue elements to injury. Vascular changes occur, resulting in the generation of a protein rich exudate. So long as the injury does not totally destroy the existing tissue architecture, the episode may resolve with restoration of original tissue architecture. Vascular changes Vasodilation occurs and persists throughout the inflammatory phase. Inflammatory cells exit the circulation at the site of injury. The equilibrium that balances Starlings forces within capillary beds is disrupted and a protein rich exudate will form as the vessel walls also become more permeable to proteins. The high fibrinogen content of the fluid may form a fibrin clot. This has several important immunomodulatory functions. Sequelae Resolution Typically occurs with minimal initial injury Stimulus removed and normal tissue architecture results Organisation Delayed removal of exudate Tissues undergo organisation and usually fibrosis Suppuration Typically formation of an abscess or an empyema Sequestration of large quantities of dead neutrophils Progression to chronic inflammation Coupled inflammatory and reparative activities Usually occurs when initial infection or suppuration has been inadequately managed Causes Infections e.g. Viruses, exotoxins or endotoxins released by bacteria Chemical agents Physical agents e.g. Trauma Hypersensitivity reactions Tissue necrosis Presence of neutrophil polymorphs is a histological diagnostic feature of acute inflammation

Answer 856

Marjolin's ulcer is a squamous cell carcinoma occurring at sites of chronic inflammation or previous injury. Lower leg ulcers Venous leg ulcers Most due to venous hypertension, secondary to chronic venous insufficiency (other causes include calf pump dysfunction or neuromuscular disorders) Ulcers form due to capillary fibrin cuff or leucocyte sequestration Features of venous insufficiency include oedema, brown pigmentation, lipodermatosclerosis, eczema Location above the ankle, painless Deep venous insufficiency is related to previous DVT and superficial venous insufficiency is associated with varicose veins Doppler ultrasound looks for presence of reflux and duplex ultrasound looks at the anatomy/ flow of the vein Management: 4 layer compression banding after exclusion of arterial disease or surgery If fail to heal after 12 weeks or >10cm2 skin grafting may be needed Marjolin's ulcer Squamous cell carcinoma Occurring at sites of chronic inflammation e.g; burns, osteomyelitis after 10-20 years Mainly occur on the lower limb Arterial ulcers Occur on the toes and heel Painful There may be areas of gangrene Cold with no palpable pulses Low ABPI measurements Neuropathic ulcers Commonly over plantar surface of metatarsal head and plantar surface of hallux The plantar neuropathic ulcer is the condition that most commonly leads to amputation in diabetic patients Due to pressure Management includes cushioned shoes to reduce callus formation Pyoderma gangrenosum Associated with inflammatory bowel disease/RA Can occur at stoma sites Erythematous nodules or pustules which ulcerate

Answer 857

Carbimazole is used to treat hyperthyroidism. Carbimazole is a pro-drug as after absorption it is converted to the active form, methimazole. Methimazole prevents thyroid peroxidase enzyme from iodinating and coupling the tyrosine residues on thyroglobulin, hence reducing the production of the thyroid hormones T3 and T4. Clinical effects take some months to occur as thyroid globulin stores remain for some time after treatment commences. Thyroid hormones Hormones of the thyroid gland Triiodothyronine T3 Major hormone active in target cells Thyroxine T4 Most prevalent form in plasma, less biologically active than T3 Calcitonin Lowers plasma calcium Synthesis and secretion of thyroid hormones Thyroid actively concentrates iodide to twenty five times the plasma concentration. Iodide is oxidised by peroxidase in the follicular cells to atomic iodine which then iodinates tyrosine residues contained in thyroglobulin. Iodinated tyrosine residues in thyroglobulin undergo coupling to either T3 or T4. Process is stimulated by TSH, which stimulates secretion of thyroid hormones. The normal thyroid has approximately 3 month reserves of thyroid hormones. LATS and Graves disease In Graves disease, patients develop IgG antibodies to the TSH receptors on the thyroid gland. This results in chronic and long term stimulation of the gland with release of thyroid hormones. The typically situation is raised thyroid hormones and low TSH. Thyroid receptor autoantibodies should be checked in individuals presenting with hyperthyroidism as they are present in up to 85% cases.

Answer 858

Anaphylactic shock: Antigen recognised by IgE molecules on the surface of mast cells resulting in rapid degranulation with release of histamine and other inflammatory cytokines. This is a case of anaphylactic shock. In anaphylaxis the mast cells degranulate. Anaphylactic shock - Suspect if there has been exposure to an allergen Management - Remove allergen - ABCD - Drugs: Adrenaline 1:1000 0.5ml INTRAMUSCULARLY (not IV). Repeat after 5 mins if no response. Consider antihistamine if ongoing local symptoms. In the refractory anaphylaxis guidance, consideration is given to adrenaline infusions. Reference Emergency treatment of anaphylactic reactions. Guidelines for healthcare providers. Working Group of the Resuscitation Council (UK).2021

Answer 859

The presence of invasion is a hallmark of invasive disease and thus would not be a feature of DCIS. Angiogenesis may occur in association with high grade DCIS. Histopathology of malignancy Abnormal tissue architecture Coarse chromatin Invasion of basement membrane* Abnormal mitoses Angiogenesis De-differentiation Areas of necrosis Nuclear pleomorphism *= Those features that distinguish invasive malignancy from in situ disease

Answer 860

The pancreas develops from two foregut outgrowths (ventral and dorsal). During rotation the ventral bud and adjacent gallbladder and bile duct lie together and fuse. When the pancreas fails to rotate normally it can compress the duodenum with development of obstruction. Usually occurring as a result of associated duodenal malformation. The second part of the duodenum is the commonest site. Pancreas The pancreas is a retroperitoneal organ and lies posterior to the stomach. It may be accessed surgically by dividing the peritoneal reflection that connects the greater omentum to the transverse colon. The pancreatic head sits in the curvature of the duodenum. Its tail lies close to the hilum of the spleen, a site of potential injury during splenectomy. Relations Posterior to the pancreas Pancreatic head Inferior vena cava Common bile duct Right and left renal veins Superior mesenteric vein and artery Pancreatic neck Superior mesenteric vein, portal vein Pancreatic body- Left renal vein Crus of diaphragm Psoas muscle Adrenal gland Kidney Aorta Pancreatic tail Left kidney Anterior to the pancreas Pancreatic head 1st part of the duodenum Pylorus SMA and SMV(uncinate process) Pancreatic body Stomach Duodenojejunal flexure Pancreatic tail Splenic hilum Superior to the pancreas Coeliac trunk and its branches common hepatic artery and splenic artery Grooves of the head of the pancreas 2nd and 3rd part of the duodenum Arterial supply Head: pancreaticoduodenal artery Rest: splenic artery Venous drainage Head: superior mesenteric vein Body and tail: splenic vein Ampulla of Vater Merge of pancreatic duct and common bile duct Is an important landmark, halfway along the second part of the duodenum, that marks the anatomical transition from foregut to midgut (also the site of transition between regions supplied by coeliac trunk and SMA).

Answer 861

The chorda tympani branch of the facial nerve passes forwards through its canaliculus into the middle ear, and crosses the medial aspect of the tympanic membrane. It then passes antero-inferiorly in the infratemporal fossa. It distributes taste fibres to the anterior two thirds of the tongue. The chorda tympani branch of the facial nerve passes forwards through its canaliculus into the middle ear, and crosses the medial aspect of the tympanic membrane. It then passes antero-inferiorly in the infratemporal fossa. It distributes taste fibres to the anterior two thirds of the tongue.

Answer 862

Subclavian steal syndrome is associated with a stenosis or occlusion of the subclavian artery, proximal to the origin of the vertebral artery. As a result, the increased metabolic needs of the arm then cause retrograde flow and symptoms of CNS vascular insufficiency. Vascular disease Aortic dissection Chest pain (anterior chest pain- ascending aorta, back pain - descending aorta) Widening of aorta on chest x-ray Diagnosis made by CT scanning Treatment is either medical (Type B disease) or surgical (Type A disease) Cervical rib Supernumery fibrous band arising from seventh cervical vertebra Incidence of 1 in 500 May cause thoracic outlet syndrome Treatment involves surgical division of rib Subclavian steal syndrome Due to proximal stenotic lesion of the subclavian artery Results in retrograte flow through vertebral or internal thoracic arteries The result is that decrease in cerebral blood flow may occur and produce syncopal symptoms A duplex scan and/ or angiogram will delineate the lesion and allow treatment to be planned Takayasu's arteritis Large vessel granulomatous vasculitis Results in intimal narrowing Most commonly affects young asian females Patients present with features of mild systemic illness, followed by pulseless phase with symptoms of vascular insufficiency Treatment is with systemic steroids Patent ductus arteriosus Ductus arteriosus is a normal foetal vessel that closes spontaneously after birth Results in high pressure, oxygenated blood entering the pulmonary circuit Untreated patients develop symptoms of congestive cardiac failure Coarctation of the aorta Aortic stenosis at the site of the ductus arteriosus insertion More prevalent in boys or females with Turners syndrome Patients may present with symptoms of arterial insufficiency, such as syncope and claudication Blood pressure mismatch may be seen, as may mismatch of pulse pressure in the upper and lower limbs Treatment is either with angioplasty or surgical resection (the former is the most common)

Answer 863

Crohns disease is worse in smokers and smoking is an independent risk factor for disease recurrence following resection. Fat wrapping of the terminal ileum is commonly seen in patients with ileal disease (the commonest disease site). The mesenteric fat in patients with IBD is often dense, hard and prone to considerable haemorrhage during surgery. At endoscopy, the mucosa in patients with Crohns disease is said to resemble cobblestones, mucosal islands (pseudopolyps) are seen in ulcerative colitis. Crohns disease Crohns disease is a chronic transmural inflammation of a segment(s) of the gastrointestinal tract and may be associated with extra intestinal manifestations. Frequent disease patterns observed include ileal, ileocolic and colonic disease. Peri-anal disease may occur in association with any of these. The disease is often discontinuous in its distribution. Inflammation may cause ulceration, fissures, fistulas and fibrosis with stricturing. Histology reveals a chronic inflammatory infiltrate that is usually patchy and transmural. Ulcerative colitis Vs Crohns Crohn's disease Ulcerative colitis Distribution Mouth to anus Rectum and colon Macroscopic changes Cobblestone appearance, apthoid ulceration Contact bleeding Depth of disease Transmural inflammation Superficial inflammation Distribution pattern Patchy Continuous Histological features Granulomas (non caseating epithelioid cell aggregates with Langhans' giant cells) Crypt abscesses, Inflammatory cells in the lamina propria Extraintestinal manifestations of Crohns Related to disease extent Unrelated to disease extent Aphthous ulcers (10%) Sacroiliiitis (10-15%) Erythema nodosum (5-10%) Ankylosing spondylitis (1-2%) Pyoderma gangrenosum (0.5%) Primary sclerosing cholangitis (Rare) Acute arthropathy (6-12%) Gallstones (up to 30%) Ocular complications (up to 10%) Renal calculi (up to 10%) Diarrhoea in Crohns Diarrhoea in Crohns may be multifactorial since actual inflammation of the colon is not common. Causes therefore include the following: Bile salt diarrhoea secondary to terminal ileal disease Entero-colic fistula Short bowel due to multiple resections Bacterial overgrowth Surgical interventions in Crohns disease The commonest disease pattern in Crohns is stricturing terminal ileal disease and this often culminates in an ileocaecal resection. Other procedures performed include segmental small bowel resections and stricturoplasty. Colonic involvement in patients with Crohns is not common and, where found, distribution is often segmental. However, despite this distribution segmental resections of the colon in patients with Crohns disease are generally not advocated because the recurrence rate in the remaining colon is extremely high. As a result, the standard options of colonic surgery in Crohns patients are generally; sub total colectomy, panproctocolectomy and staged sub total colectomy and proctectomy. Restorative procedures such as ileoanal pouch have no role in therapy. Crohns disease is notorious for the developmental of intestinal fistulae; these may form between the rectum and skin (peri anal) or the small bowel and skin. Fistulation between loops of bowel may also occur and result in bacterial overgrowth and malabsorption. Management of enterocutaneous fistulae involves controlling sepsis, optimising nutrition, imaging the disease and planning definitive surgical management.

Answer 864

Calcitonin is clinically utilised to screen for medullary thyroid cancer recurrence. Thyroid function testing does not form part of either diagnosis or follow up from a malignancy perspective. However, routine assessment of TSH may be needed in patients on thyroxine. Thyroid malignancy Papillary carcinoma Commonest sub-type Accurately diagnosed on fine needle aspiration cytology Histologically, they may demonstrate psammoma bodies (areas of calcification) and so called 'orphan Annie' nuclei They typically metastasise via the lymphatics and thus laterally located apparently ectopic thyroid tissue is usually a metastasis from a well differentiated papillary carcinoma Follicular carcinoma Are less common than papillary lesions Like papillary tumours, they may present as a discrete nodule. Although they appear to be well encapsulated macroscopically there is invasion on microscopic evaluation Lymph node metastases are uncommon and these tumours tend to spread haematogenously. This translates into a higher mortality rate Follicular lesions cannot be accurately diagnosed on fine needle aspiration cytology and thus all follicular FNA's (THY 3f) will require at least a hemi thyroidectomy Anaplastic carcinoma Less common and tend to occur in elderly females Disease is usually advanced at presentation and often only palliative decompression and radiotherapy can be offered. Medullary carcinoma These are tumours of the parafollicular cells ( C Cells) and are of neural crest origin. The serum calcitonin may be elevated which is of use when monitoring for recurrence. They may be familial and occur as part of the MEN -2A disease spectrum. Spread may be either lymphatic or haematogenous and as these tumours are not derived primarily from thyroid cells they are not responsive to radioiodine. Lymphoma These respond well to combined chemoradiotherapy Radical surgery is unnecessary once the disease has been diagnosed on biopsy material. Such biopsy material is not generated by an FNA and thus a core biopsy has to be obtained (with care!).

Answer 865

Ansa cervicalis muscles: GHost THought SOmeone Stupid Shot Irene GenioHyoid ThyroidHyoid Superior Omohyoid SternoThyroid SternoHyoid Inferior Omohyoid Mylohyoid is innervated by the mylohyoid branch of the inferior alveolar nerve.

Answer 866

At its distal end, the patent processes vaginalis will envelop the testis. Both visceral and parietal layers will be present. Fluid of a hydrocele does not collect in the other spaces. Scrotal and testicular anatomy Spermatic cord Formed by the vas deferens and is covered by the following structures: Layer Origin Internal spermatic fascia Transversalis fascia Cremasteric fascia From the fascial coverings of internal oblique External spermatic fascia External oblique aponeurosis Contents of the cord Vas deferens Transmits sperm and accessory gland secretions Testicular artery Branch of abdominal aorta supplies testis and epididymis Artery of vas deferens Arises from inferior vesical artery Cremasteric artery Arises from inferior epigastric artery Pampiniform plexus Venous plexus, drains into right or left testicular vein Sympathetic nerve fibres Lie on arteries, the parasympathetic fibres lie on the vas Genital branch of the genitofemoral nerve Supplies cremaster Lymphatic vessels Drain to lumbar and para-aortic nodes Scrotum Composed of skin and closely attached dartos fascia. Arterial supply from the anterior and posterior scrotal arteries Lymphatic drainage to the inguinal lymph nodes Parietal layer of the tunica vaginalis is the innermost layer Testes The testes are surrounded by the tunica vaginalis (closed peritoneal sac). The parietal layer of the tunica vaginalis adjacent to the internal spermatic fascia. The testicular arteries arise from the aorta immediately inferiorly to the renal arteries. The pampiniform plexus drains into the testicular veins, the left drains into the left renal vein and the right into the inferior vena cava. Lymphatic drainage is to the para-aortic nodes.

Answer 867

The subclavian artery lies posterior to scalenus anterior, the vein lies in front. Sibson's fascia is another name for the suprapleural membrane. Root of the neck Thoracic Outlet Where the subclavian artery and vein and the brachial plexus exit the thorax and enter the arm. They pass over the 1st rib and under the clavicle. The subclavian vein is the most anterior structure and is immediately anterior to scalenus anterior and its attachment to the first rib. Then subclavian artery passes between the anterior and middle scalene muscles. At the level of the first rib, the lower cervical nerve roots combine to form the 3 trunks of the brachial plexus. The lowest trunk is formed by the union of C8 and T1, and this trunk lies directly posterior to the artery and is in contact with the superior surface of the first rib. Thoracic outlet obstruction causes neurovascular compromise.

Answer 868

The posterior longitudinal ligament overlies the posterior aspect of the vertebral bodies. It also overlies the posterior aspect of the intervertebral discs. Intervertebral discs Consist of an outer annulus fibrosus and an inner nucleus pulposus. The anulus fibrosus consists of several layers of fibrocartilage. The nucleus pulposus contains loose fibres suspended in a mucoprotein gel with the consistency of jelly. The nucleus of the disc acts as a shock absorber. Pressure on the disc causes posterior protrusion of the nucleus pulposus. Most commonly in the lumbrosacral and lower cervical areas. There is one disc between each pair of vertebrae, except for C1/2 and the sacrococcygeal vertebrae.

Answer 869

Of the muscles listed, only the abductor pollicis brevis is innervated by the median. In questions like this one, ensure you don't become confused between adductor and abductor. Abductor pollicis brevis Origin Fleshy fibres from the flexor retinaculum, scaphoid and trapezium Insertion Via a short tendon into the radial side of the proximal phalanx of the thumb Nerve Recurrent branch of median nerve in the palm Actions Abducts the thumb at the carpometacarpal and metacarpophalangeal joints, causing it to travel anteriorly at right angles to the plane of the palm and to rotate medially (e.g. typing). When the thumb is fully abducted there is angulation of around 30 degrees between the proximal phalanx and the metacarpal. Because of the direction of the muscle, abduction involves medial rotation of the metacarpal, and the abductor is used along with opponens pollicis in the initial stages of thumb opposition

Answer 870

Of the conditions listed, Pagets disease is the most likely diagnosis (skull vault expansion and sensorineural hearing loss). Multiple myeloma would typically result in multiple areas of radiolucency and usually raised calcium in this setting. Osteopetrosis is a recognised cause of the features described. However, it is a rare inherited disorder and usually presents in children in young adults. Presentation at this stage with no prior symptoms would be extremely rare and therefore this is not the most likely diagnosis. Pagets disease Paget's disease is a disease of increased but uncontrolled bone turnover and is characterised by architecturally abnormal bones. It is thought to be primarily a disorder of osteoclasts, with excessive osteoclastic resorption followed by increased osteoblastic activity causing areas of sclerosis and deformity. Paget's disease is common (UK prevalence 5%) but symptomatic in only 1 in 20 patients Predisposing factors increasing age male sex northern latitude family history Clinical features bone pain (e.g. pelvis, lumbar spine, femur) classical, untreated features: bowing of tibia, bossing of skull raised alkaline phosphatase (ALP) - calcium* and phosphate are typically normal skull x-ray: thickened vault, osteoporosis circumscripta Indications for treatment include bone pain, skull or long bone deformity, fracture, periarticular Paget's bisphosphonate (either oral risedronate or IV zoledronate) calcitonin is less commonly used now Complications deafness (cranial nerve entrapment) bone sarcoma (1% if affected for > 10 years) fractures skull thickening high-output cardiac failure *usually normal in this condition but hypercalcaemia may occur with prolonged immobilisation

Answer 871

The history of varicose veins should indicate a more likely diagnosis of a varix. The varix can enlarge during coughing/sneezing. A blue discolouration may be noted. Groin masses clinical Groin masses are common and include: Herniae Lipomas Lymph nodes Undescended testis Femoral aneurysm Saphena varix (more a swelling than a mass!) In the history, features relating to systemic illness and tempo of onset will often give a clue as to the most likely underlying diagnosis. Groin lumps- some key questions Is there a cough impulse Is it pulsatile AND is it expansile (to distinguish between false and true aneurysm) Are both testes intra scrotal Any lesions in the legs such as malignancy or infections (?lymph nodes) Examine the ano rectum as anal cancer may metastasise to the groin Is the lump soft, small and very superficial (?lipoma) Scrotal lumps - some key questions Is the lump entirely intra scrotal Does it transilluminate (?hydrocele) Is there a cough impulse (?hernia) In most cases a diagnosis can be made clinically. Where it is not clear an ultrasound scan is often the most convenient next investigation.

Answer 872

Note, the question asked for least likely. That being the case, the correct answer is small cell lung cancer as they are nearly always disseminated at diagnosis. Lung cancer Lung cancers may be classified according to histological subtypes. The main distinction is between small cell and non small cell lung cancer. Non small cell lung cancer is the most common variant and accounts for 80% of all lung cancers. Non small cell lung cancer These share common features of prognosis and management. They comprise the following tumours: Squamous cell carcinoma (25% cases) Adenocarcinoma (40% cases) Large cell carcinoma (10% cases) Paraneoplastic features and early disease dissemination are less likely than with small cell lung carcinoma. Adenocarcinoma is the most common lung cancer type encountered in never smokers. Small cell lung carcinoma Small cell lung carcinomas are comprised of cells with a neuro endocrine differentiation. The neuroendocrine hormones may be released from these cells with a wide range of paraneoplastic associations. These tumours are strongly associated with smoking and will typically arise in the larger airways. They disseminate early in the course of the disease and although they are usually chemosensitive this seldom results in long lasting remissions.

Answer 873

Mnemonic for structures posterior to the medial malleolus: Tom Dick And Nervous Harry T ibialis posterior tendon flexor Digitorum longus A rtery N erve H allucis longus Medial malleolus The following structures pass posterior to medial malleolus (in order): Tibialis posterior tendon Flexor digitorum longus tendon Posterior tibial artery Tibial nerve Tendon of flexor hallucis longus

Answer 874

The sciatic nerve is traditionally viewed as being a nerve of the posterior compartment. It is known to contribute to the innervation of adductor magnus (although the main innervation to this muscle is from the obturator nerve). The quadriceps femoris is nearly always innervated by the femoral nerve. Sciatic nerve The sciatic nerve is formed from the sacral plexus and is the largest nerve in the body. It is the continuation of the main part of the plexus arising from ventral rami of L4 to S3. These rami converge at the inferior border of piriformis to form the nerve itself. It passes through the inferior part of the greater sciatic foramen and emerges beneath piriformis. Medially, lie the inferior gluteal nerve and vessels and the pudendal nerve and vessels. It runs inferolaterally under the cover of gluteus maximus midway between the greater trochanter and ischial tuberosity. It receives its blood supply from the inferior gluteal artery. The nerve provides cutaneous sensation to the skin of the foot and the leg. It also innervates the posterior thigh muscles and the lower leg and foot muscles. The nerve splits into the tibial and common peroneal nerves approximately half way down the posterior thigh. The tibial nerve supplies the flexor muscles and the common peroneal nerve supplies the extensor muscles and the evertor muscles of the foot. Summary points Origin Spinal nerves L4 - S3 Articular Branches Hip joint Muscular branches in upper leg Semitendinosus Semimembranosus Biceps femoris Part of adductor magnus Cutaneous sensation Posterior aspect of thigh (via cutaneous nerves) Gluteal region Entire lower leg (except the medial aspect) Terminates At the upper part of the popliteal fossa by dividing into the tibial and peroneal nerves The nerve to the short head of the biceps femoris comes from the common peroneal part of the sciatic and the other muscular branches arise from the tibial portion. The tibial nerve goes on to innervate all muscles of the foot except the extensor digitorum brevis (which is innervated by the common peroneal nerve).

Answer 875

Mutation of mismatch repair genes or Lynch syndrome which is characterised by aggressive right sided colonic malignancy and endometrial cancer is caused by microsatellite instability of DNA repair genes. Genetics of colorectal cancer The lifetime risk of colorectal cancer in the UK population is 5%. Up to 5% of newly diagnosed bowel cancers will be in those individuals who have a high genetically acquired risk of bowel cancer. Cancers arising in the low-moderate genetic risk group comprise approximately 30% of newly diagnosed bowel cancer. Genetics of inherited colorectal cancer syndromes Syndrome Features Genes implicated FAP More than 100 adenomatous polyps affecting the colon and rectum. Duodenal and fundic glandular polyps APC (over 90%) Gardner syndrome As FAP but with desmoid tumours and mandibular osteomas APC Turcots syndrome Polyposis and colonic tumours and CNS tumours APC +MLH1 and PMS2 HNPCC Colorectal cancer without extensive polyposis. Endometrial cancer, renal and CNS MSH2, MLH1, PMS2 and GTBP Peutz-Jeghers syndrome Hamartomatous polyps in GI tract and increased risk of GI malignancy LKB1 andSTK11 (in up to 70%) Cowden disease Multiple hamartomas (see below) PTEN (85%) MYH associated polyposis Autosomal recessive, multiple adenomatous polyps in GI tract, those in colon having somatic KRAS mutations MYH FAP Autosomal dominant condition, affects 1 in 12,000. Accounts for 0.5% of all CRCs. Lifetime incidence of colorectal cancer in untreated FAP =100%. Up to 25% cases are caused by de-novo germ line mutations and show no prior family history. The APC tumour suppressor gene is affected in most cases. APC in non inherited colorectal cancer Up to 80% of sporadic colorectal cancers will have somatic mutations that inactivate APC[1]. Both alleles are usually affected. Although the APC protein more than likely has multiple critical cellular functions, the best-established role for APC in the cancer process is as a major binding partner and regulator of the β- catenin protein in the so-called canonical or β- catenin dependent Wnt signaling pathway. HNPCC (Lynch syndrome) HNPCC cancers differ from conventional tumours in a number of respects. In the colon the tumours are more likely to be right sided, histologically they are more likely to be mucinous and have dense lymphocytic infiltrates. To be diagnosed as having HNPCC individuals must show typically HNPCC tumours in at least three individuals, (one of whom must be a first degree relative to the other two). In at least two successive generations. At least one cancer must be diagnosed under the age of 50. FAP must be excluded and tumours should be verified by pathological identification (Amsterdam criteria). The genetic changes in HNPCC stem primarily from microsatellite instability affecting DNA mismatch repair genes. In HNPCC the mismatch repair genes most commonly implicated include; MSH2 and MLH1 and these occur in up to 70% of people with HNPCC. The finding of microsatellite instability is unusual in sporadic colorectal cancers. Approximately 60% of individuals who fulfill the Amsterdam criteria will not be found to have evidence of mismatch repair gene defects on genetic testing. The risk of developing colorectal cancer in those who have not demonstrated mutation of the mis match repair genes is increased if they fulfill the Amsterdam criteria, but not the extent that it is increased in those who fulfill the criteria AND have evidence of mis match repair gene defects. KRAS Mutations The RAS family of small G proteins act as molecular switches downstream of growth factor receptors. KRAS and the other two members of the family; HRAS and NRAS, are the site of mutation in approximately 40% of colorectal cancers. When adenomas are examined the proportion of adenomas less than 1cm showing KRAS mutations was only 10% which contrasts with 50% in those lesions greater than 1cm. p53 mutations The p53 protein functions as a key transcriptional regulator of genes that encode proteins with functions in cell-cycle checkpoints at the G1/S and G2/M boundaries, in promoting apoptosis, and in restricting angiogenesis . As such, selection for p53 defects at the adenoma-carcinoma transition may reflect the fact that stresses on tumor cells activate cell-cycle arrest, apoptotic, and antiangiogenic pathways in cells with wild-type p53 function. Many colonic tumours will demonstrate changes in the p53 gene that may facilitate tumour progression through from adenoma to carcinoma. Cowden syndrome Also known as multiple hamartoma syndrome. Rare autosomal dominant condition with incidence of 1 in 200,000.. It is characterised by multiple mucocutaneous lesions, trichilemmomas, oral papillomas and acral keratosis. Most often diagnosed in third decade of life. Breast carcinoma may occur in up to 50% of patients and conditions such as fibrocystic disease of the breast may occur in 75% of women. Thyroid disease occurs in 75% and may include malignancy. Endoscopic screening will identify disease in up to 85% although the small bowel is rarely involved. There is a 15-20% risk of developing colorectal cancer and regular colonoscopic screening from age 45 is recommended. Terminology Oncogene Oncogenes are genes which have the potential to induce cellular proliferation and avoid apoptosis. Oncogene mutations are general gain of function and are therefore dominant. Increased expression of oncogenes are found in most tumours Tumour suppressor gene These genes generally inhibit cellular proliferation or induce apoptosis. Mutations in tumour suppressor genes are generally loss of function mutations, and are therefore recessive. Mutations in both tumour suppressor gene alleles allow cells to proliferate without restraint References 1. Fearon, E.R. and B. Vogelstein, A genetic model for colorectal tumorigenesis. Cell, 1990. 61(5): p. 759-67.

Answer 876

There are 4 collateral venous systems: Azygos venous system Internal mammary venous pathway Long thoracic venous system with connections to the femoral and vertebral veins (2 pathways) Despite this, venous hypertension still occurs. Superior vena cava Drainage Head and neck Upper limbs Thorax Part of abdominal walls Formation Subclavian and internal jugular veins unite to form the right and left brachiocephalic veins These unite to form the SVC Azygos vein joins the SVC before it enters the right atrium Relations Anterior Anterior margins of the right lung and pleura Posteromedial Trachea and right vagus nerve Posterolateral Posterior aspects of right lung and pleura Pulmonary hilum is posterior Right lateral Right phrenic nerve and pleura Left lateral Brachiocephalic artery and ascending aorta Developmental variations Anomalies of the connection of the SVC are recognised. In some individuals a persistent left sided SVC drains into the right atrium via an enlarged orifice of the coronary sinus. More rarely the left sided vena cava may connect directly with the superior aspect of the left atrium, usually associated with an un-roofing of the coronary sinus. The commonest lesion of the IVC is for its abdominal course to be interrupted, with drainage achieved via the azygos venous system. This may occur in patients with left sided atrial isomerism.

Answer 877

Right subclavian artery The axillary artery is a branch of the subclavian artery and although developmental anomalies may occur they are rare. The catheter may also enter the right carotid. There is no brachiocephalic artery on the left side. Brachiocephalic artery The brachiocephalic artery is the largest branch of the aortic arch. From its aortic origin it ascends superiorly, it initially lies anterior to the trachea and then on its right hand side. It branches into the common carotid and right subclavian arteries at the level of the sternoclavicular joint. Path Origin- apex of the midline of the aortic arch Passes superiorly and posteriorly to the right Divides into the right subclavian and right common carotid artery Relations Anterior Sternohyoid Sternothyroid Thymic remnants Left brachiocephalic vein Right inferior thyroid veins Posterior Trachea Right pleura Right lateral Right brachiocephalic vein Superior part of SVC Left lateral Thymic remnants Origin of left common carotid Inferior thyroid veins Trachea (higher level) Branches Normally none but may have the thyroidea ima artery

Answer 878

A Arterial blood gas interpretation In advanced life support training, a 5 step approach to arterial blood gas interpretation is advocated. 1. How is the patient? 2. Is the patient hypoxaemic? The Pa02 on air should be 10.0-13.0 kPa 3. Is the patient acidaemic (pH <7.35) or alkalaemic (pH >7.45) 4. What has happened to the PaCO2? If there is acidaemia, an elevated PaCO2 will account for this 5. What is the bicarbonate level or base excess? A metabolic acidosis will have a low bicarbonate level and a low base excess (< -2 mmol) A metabolic alkalosis will have a high bicarbonate and a high base excess (> +2 mmol)

Answer 879

A-Noradrenaline Since the main issue here is vasodilation, a vasoconstrictor is most likely to be helpful. Circulatory support of the critically ill Circulatory support Impaired tissue oxygenation may occur as a result of circulatory shock. Shock is considered further under its own topic heading. Patients requiring circulatory support require haemodynamic monitoring. At its simplest level this may simply be in the form of regular urine output measurements and blood pressure monitoring. In addition ECG monitoring will allow the identification of cardiac arrhythmias. Pulse oximeter measurements will allow quick estimation haemoglobin oxygen saturation in arterial blood. Invasive arterial blood pressure monitoring is undertaken by the use of an indwelling arterial line. Most arterial sites can be used although the radial artery is the commonest. It is important not to cannulate end arteries. The arterial trace can be tracked to ventilation phases and those patients whose systolic pressure varies with changes in intrathoracic pressure may benefit from further intravenous fluids. Central venous pressure is measured using a CVP line that is usually sited in the superior vena cava via the internal jugular route. The CVP will demonstrate right atrial filling pressure and volume status. When adequate intra vascular volume is present a fluid challenge will typically cause a prolonged rise in CVP (usually greater than 6-8mmHg). To monitor the cardiac output a Swan-Ganz catheter is traditionally inserted (other devices may be used and are less invasive). Inflation of the distal balloon will provide the pulmonary artery occlusion pressure and the pressure distal to the balloon will equate to the left atrial pressure. This gives a measure of left ventricular preload. Because the Swan-Ganz catheter can measure several variables it can be used to calculate: Stroke volume Systemic vascular resistance Pulmonary artery resistance Oxygen delivery (and consumption) Inotropes In patients with an adequate circulating volume but on-going circulatory compromise a vasoactive drug may be considered. These should usually be administered via the central venous route. Commonly used inotropes include: Agent Mode of action Effect Noradrenaline α agonist Vasopressor action, minimal effect on cardiac output Adrenaline α and β receptor agonist Increases cardiac output and peripheral vascular resistance Dopamine β1 agonist Increases contractility and rate Dobutamine β1 and β2 agonist Increases cardiac output and decreases SVR Milrinone Phosphodiesterase inhibitor Elevation of cAMP levels improves muscular contractility, short half life and acts as vasodilator

Answer 880

Mnemonic for the Carpal Bones Sally Likes To Play The Tiny Chrome Harmonica She Looks Too Pretty Try To Catch Her Scared Lovers Try Positions That They Can't Handle Trapezius is a muscle of the back. Carpal bones The wrist is comprised of 8 carpal bones, these are arranged in two rows of 4. It is convex from side to side posteriorly and concave anteriorly.

Answer 881

A Hill-Sachs lesion occurs when the cartilage surface of the humerus is in contact with the rim of the glenoid. About 50% of anterior glenohumeral dislocations are associated with this lesion. Shoulder disorders Shoulder fractures and dislocations Fractures Proximal humerus Background Third most common fragility fracture in the elderly. Results from low energy fall in predominantly elderly females, or from high energy trauma in young males. Can be associated with nerve injury (commonly axillary), and fracture-dislocation of the humeral head. Detailed neurological assessment is essential for all upper limb injuries. Anatomy Osteology Consists of articular head, greater tuberosity, lesser tuberosity, metaphysis and diaphysis. Between the articular head and the tuberosities is the anatomical neck (previous physis). Between the tuberosities and the metaphysis is the surgical neck. The supraspinatus, infraspinatus and teres minor muscles attach to the greater tuberosity. The subscapularis muscle attaches to the lesser tuberosity. Vascular Supply Humeral head is supplied by the anterior and posterior humeral circumflex arteries. Anatomical neck fractures are at greatest risk of osteonecrosis. Imaging Imaging aims to both delineate the fracture pattern, and confirm/exlude the presence of an associated dislocation. Radiographs - True anteroposterior (AP), axillary lateral and/or scapula Y view. CT - indicated to better define intra-articular involvement and to aid pre-operative planning. MRI is not useful for fracture imaging. Classification Description of the fracture is often more useful than classification. Particular attention should be paid to humeral alignment, fracture displacement, and greater tuberosity position (rotator cuff will pull the GT supero-posterioly, which can cause impingement problems with malunion). - Neer Classification: Most commonly used. Describes fracture as 2,3,or 4 part depending upon the number main fragments. Also comments on the degree of displacement. Fragments: -greater tuberosity -lesser tuberosity - articular surface - shaft Displacement: >1cm or angulation >45 degrees. Treatment The vast majority of proximal humeral fractures are minimally displaced, and therefore can be managed conservatively. This involves immobilisation in a polysling, and progressive mobilisation. Pendular exercise can commence at 14 days, and active abduction from 4-6 weeks. Irreducible fracture dislocation is an indication for operative management. Other indications include large displacement, younger patient, head splitting (intra-articular fractures). However, the recent PROFHER trial (1) has suggested no benefit to operative intervention on patient outcome (it must be applied cautiously as majority of patients were elderly with extraarticular fractures). Options available for surgical management include: ORIF Most commonly used. Plate and screw fixation. Can reconstruct complex fractures. Intramedullary nail Suitable for extra-articular configuration, predominantly surgical neck +/- GT fractures. Hemiarthroplasty Used for un-reconstructable fractures in the older patient who has good glenoid quality. Total shoulder arthroplasty Unconstructable fractures where high functioning shoulder is required (hemiarthroplasty will cause glenoid erosion) Reverse shoulder arthroplasty Total shoulder arthroplasty that provides better functional outcome than conventional total shoulder replacement. Scapula Background Uncommon fractures usually associated with high energy trauma. Most commonly involve scapula body or spine (50%), glenoid fossa and glenoid neck. Important to exclude associated life threatening injury. Imaging Plain radiographs should include true anteroposterior (AP), axillary lateral and/or scapula Y view. CT scanning is useful for defining intra-articular involvement, displacement and for three dimensional reconstruction. Classification Based on the location of the fracture (coracoid, acromion, glenoid neck, glenoid fossa, scapula body). Beware of ipsilateral glenoid neck and clavicle fracture -floating shoulder - where limb is effectively dissociated from axial skeleton. Treatment The vast majority of scapula fractures are amenable to conservative management, consisting of sling immobilisation for two weeks followed by early rehabilitation. Floating shoulder will usually require fixation, and consideration of surgery should also be given to intra-articular and displaced/angulated glenoid fractures. Dislocations Types Dislocations around the shoulder joint include glenohumeral dislocation, acromioclavicular joint disruption and sternoclavicular dislocation. Only glenohumeral dislocation will be covered here. Glenohumeral dislocation Diagnosis, classification and management are covered here. Background Shoulder dislocation is commonly seen in A&E. It has a high recurrence rate that is as high as 80% in teenagers. Initial management requires emergent reduction to prevent lasting chondral damage. Early assessment and management Usually a traumatic cause (multi-directional instability in frequent dislocations requires discussion with orthopaedics and is not covered here). Careful history, examination and documentation of neurovascular status of the limb, in particular the axillary nerve (regimental badge sensation). This should be re-assessed post manipulation. Early radiographs to confirm direction of dislocation. Initial management consists of emergent closed reduction under under entanox and analgesia, but often requires conscious sedation. Arm should then be immobilised in a polysling, and XR to confirm relocation. Imaging - True anteroposterior (AP), axillary lateral and/or scapula Y view. Reduced humeral head should lie between acromion and coracoid on lateral/scapula view. Types Direction Features Cause Examination Reduction techniques Anterior Most Common >90% Usually traumatic - anterior force on arm when shoulder is abducted, externally rotated Loss of shoulder contour - sulcus sign. Humeral head can be felt anteriorly. Hippocratic. Milch. Stimson. Kocher not advised due to complication of fracture Posterior 50% missed in A&E 50% traumatic, but classically post seizure or electrocution Shoulder locked in internal rotation. XR may show lightbulb appearance. Gentle lateral traction to adducted arm. Inferior Rare Associated with pectorals and rotator cuff tears, and glenoid fracture As for primary injury Management of primary injury Superior Rare Associated with acrominon/clavicle fracture As for primary injury Management of primary injury Associated injuries Bankart lesion - avulsion of the anterior glenoid labrum with an anterior shoulder dislocation (reverse Bankart if poster labrum in posterior dislocation). Hill Sachs defect - chondral impaction on posteriosuperior humeral head from contact with gleonoid rim. Can be large enough to lock shoulder, requiring open reduction. (Reverse Hill Sachs in posterior dislocation). Rotator cuff tear - increases with age. Greater or lesser tuberosity fracture - increases with age. Humeral neck fracture - shoulder fracture dislocation. More common in high energy trauma and elderly. Should be discussed with orthopaedics prior to any attempted reduction. Rotator Cuff Disease Rotator cuff disease is a spectrum of conditions that ranges from subacromial impingement to rotator cuff tears and eventually to rotator cuff arthropathy (arthritis). Anatomy The rotator cuff is a group of four muscles that are important in shoulder movements, and maintenance of glenohumeral stability. Muscle Scapular attachment Humeral attachment Action Innervation Supraspinatus Supraspinatus fossa Superior facet of greater tuberosity Initiation of abduction of humerus Suprascapular nerve Infraspinatus Infraspinatus fossa Posterior facet of greater tuberosity External rotation of humerus Suprascapular nerve Teres Minor Lateral border Inferior facet of greater tuberosity External rotation of humerus Axillary Nerve Subscapularis Subscapular fossa Lesser tuberosity Internal rotation of humerus Upper and lower subscapular nerve The inferior rotator cuff muscles (infraspinatus, teres minor, and subscapularis) balance the superior pull of the deltoid. Injury/tear results in upward migration of the humeral head on the glenoid (can be seen on AP radiograph). Likewise, the anterior muscles (subscapularis) are balanced with the posterior muscles (infraspinatus, teres minor). Subacromial Impingement The most common cause of shoulder pain, which results from impingement of the superior cuff on the undersurface of the acromion, and an inflammatory bursitis. Associated with certain types of acromial morphology (Bigliani classification). Presents as insidious pain which is exacerbated by overhead activities. Rotator Cuff Tear Often presents as an acute event on the background of chronic subacromial impingement in the older patient, but can present as an avulsion injury in younger patients. Majority of tears are to the superior cuff (supraspinatus, infraspinatus, teres minor), though a tear to subscapularis is associated with subcoracoid impingement. Tears present as pain and weakness when using the muscles in question. Rotator Cuff Arthropathy Defined as shoulder arthritis in the setting of rotator cuff dysfunction. Results from superior migration due to the loss of rotator cuff function and integrity. Unopposed deltoid pulls the humeral head superiorly. Associated with massive chronic cuff tears. Imaging Plain radiographs AP of the shoulder may show superior migration of the humerus with a cuff tear, and features of arthritis with arthropathy. Other causes of pain may also be identified (e.g. calcific tendonitis/fracture) Outlet view is useful for defining the acromial morphology USS Allows dynamic imaging of the cuff, and is inexpensive. However, it is very user dependent. MRI Best imaging modality for cuff pathology. Also allows imaging of the rest of the shoulder. When intra-articular pathology is suspected, can be combined with an arthrogram for improved sensitivity and specificity. Treatment Subacromial impingement Physiotherapy, oral anti-inflammatory medication Subacromial steroid injection can settle inflammation Arthroscopic subacromial decompression by shaving away the undersurface of the acromion, more space is created for the rotator cuff. Cuff integrity is assessed also at time of surgery, and can be repaired if necessary. Rotator cuff tear When considering repair of a cuff tear, the age and activity of the patient, the nature of the tear (degenerative vs. acute traumatic), and the size and retraction of the tear should be considered when making a surgical plan. Mild tears or tears in the elderly can be managed conservatively, as outlined above. Moderate tears can be repaired arthroscopically. Massive or retracted tears will often require an open repair (occasionally with a tendon transfer). Subacromial decompression is performed at the same time to reduce impingement, symptoms and recurrence. Calcific tendonitis Calcific tendonitis involves calcific deposits within tendons anywhere in the body, but most commonly in the rotator cuff (specifically the supraspinatus tendon). When present in the shoulder, it is associated with subacromial impingement and pain. Pathology More common in women aged 30-60 years. Association with diabetes and hypothyroidism There are three stages of calcification Formative phase characterized by calcific deposits Resting phase deposit is stable, but presents with impingement problems Resorptive phase phagocytic resorption. Most painful stage. Presentation Similar in presentation to subacromial impingement, with pain especially with over head activities. Atraumatic in nature. Imaging Plain radiographs show calcification of the rotator cuff, usually within 1.5cm of its insertion on the humerus. Supraspinatus outlet views can show level of impingment. Further imaging is rarely needed. Treatment Non-operative NSAIDS, steroid injection (controversial, but practiced) and physiotherapy. Approximately 75% will resolve by 6 months with conservative management. Ultrasound guided or surgical needle barbotage can break down deposits and resolve symptoms. Occasionally surgical excision is required. Adhesive capsulitis (Frozen Shoulder) Pain and loss of movement of shoulder joint, which involves fibroplastic proliferation of capsular tissue, causing soft tissue scarring and contracture. Patients present with a painful and decreased arc of motion. Associated with prolonged immobilization, previous surgery, thyroid disorders (AI) and diabetes Classically three stages which can take up to two years to resolve: Stage one the freezing and painful stage Stage two the frozen and stiff stage Stage three the thawing stage, where shoulder movement slowly improves Imaging Plain radiographs to exclude other causes of a painful shoulder MRI arthrogram may show capsular contracture, and again may be used to exclude cuff pathology. However, often not performed as diagnosis is largely clinical. Treatment Non-operative NSAIDS, steroid injection and physiotherapy. Patience is required as condition can take up to 2 years to improve. Operative MUA or arthroscopic adhesiolysis (release of adhesions) can expedite recovery, followed by intensive physiotherapy. Glenohumeral Arthritis Background May be osteoarthritis (primary or secondary to cuff tear or trauma), rheumatoid arthritis, or as part of a spondyloarthropathy. Majority of those with RA will develop symptoms. More common in the elderly Presents like any other arthritis - pain at night and with movement Imaging AP and axillary radiographs will show features of arthritis. CT/MRI is often useful to classify the shape of the glenoid and extent of bone loss when considering arthroplasty. MRI also essential to asses integrity of rotator cuff if considering shoulder replacement. Treatment Like all orthopaedics, start with simple measures: NSAIDS, management of RA, physiotherapy, steroid injection. Hemiarthroplasty can sometimes be considered if glenoid is in excellent condition or if patient has large comorbidity. Arthroscopic debridement is useful if patient has isolated ACJ arthritis, but is rarely used for glenohumeral arthritis. Total shoulder replacement is shown to produce superior outcome when compared to hemiarthroplasty in terms of pain relief, function and implant survival. Total shoulder replacement can be anatomical (ball on humerus, with cup on glenoid), or reverse geometry (ball on glenoid, with cup on humerus). Anatomical TSR requires an in tact rotator cuff, so often reverse is preferable when the cuff if questionable in integrity. References 1. JAMA. 2015;313(10):1037-1047. doi:10.1001/jama.2015.1629

Answer 882

Cutting current The high energy levels result in tissue vaporisation and cleavage of tissues. Electrosurgery Electrosurgery utilises the heat generated by the passage of high frequency alternating electrical current through living tissues. The application of a voltage across human tissue results in the formation of an electrical circuit between the voltage source and the tissue. The tissue acts as a resistor and the level of resistance is determined by the water content of the tissue. It is this resistance that results in the formation of heat. An alternating current constantly changes the direction in which the current flows, the speed with which this occurs is measured in Hertz. Most diathermy units operate at a frequency of between 200,000 kHZ to 5MHz. This means that tissue such as nerves and muscles will not depolarise (since this seldom occurs at frequencies above 10,000Hz). The current waveform can be adjusted to deliver three main therapeutic modalities; cutting, coagulation and blend. Types of current Cutting Sinusoidal and non modulated waveform High average power and current density Precise cutting without thermal damage Coagulation Modulated current with intermittent dampened sine waves of high peak voltage Evaporation, rather than vaporisation of intracellular fluid occurs Results in formation of coagulum Desication Active electrode in direct contact with tissue Low current and high voltage system Results in loss of cellular water but no protein damage Fulguration Electrode probe is held away from tissue Produces spray effect with local, superficial tissue destruction Low amplitude and high voltage system Blend Alternating cutting and coagulation modes Total average power is less than with cutting

Answer 883

The trachea is normally deviated to the right. Thoracic aorta rupture Mechanism of injury: Decelerating force i.e. RTA, fall from a great height Most people die at scene Survivors may have an incomplete laceration at the ligamentum arteriosum of the aorta. Clinical features Contained haematoma: persistent hypotension Detected mainly by history, CXR changes CXR changes Widened mediastinum Trachea/Oesophagus to right Depression of left main stem bronchus Widened paratracheal stripe/paraspinal interfaces Space between aorta and pulmonary artery obliterated Rib fracture/left haemothorax Diagnosis Angiography, usually CT aortogram. Treatment Repair or replacement. Ideally they should undergo endovascular repair.

Answer 884

The loss of extension is secondary to triceps injury which reflects its innervation by the radial nerve. Radial nerve Continuation of posterior cord of the brachial plexus (root values C5 to T1) Path In the axilla: lies posterior to the axillary artery on subscapularis, latissimus dorsi and teres major. Enters the arm between the brachial artery and the long head of triceps (medial to humerus). Spirals around the posterior surface of the humerus in the groove for the radial nerve. At the distal third of the lateral border of the humerus it then pierces the intermuscular septum and descends in front of the lateral epicondyle. At the lateral epicondyle it lies deeply between brachialis and brachioradialis where it then divides into a superficial and deep terminal branch. Deep branch crosses the supinator to become the posterior interosseous nerve. Regions innervated Motor (main nerve) Triceps Anconeus Brachioradialis Extensor carpi radialis Motor (posterior interosseous branch) Supinator Extensor carpi ulnaris Extensor digitorum Extensor indicis Extensor digiti minimi Extensor pollicis longus and brevis Abductor pollicis longus Sensory The area of skin supplying the proximal phalanges on the dorsal aspect of the hand is supplied by the radial nerve (this does not apply to the little finger and part of the ring finger) Muscular innervation and effect of denervation Anatomical location Muscle affected Effect of paralysis Shoulder Long head of triceps Minor effects on shoulder stability in abduction Arm Triceps Loss of elbow extension Forearm Supinator Brachioradialis Extensor carpi radialis longus and brevis Weakening of supination of prone hand and elbow flexion in mid prone positio

Answer 885

D-The adrenal gland releases adrenaline in response to increased sympathetic discharge from preganglionic sympathetic fibres of the splanchnic nerves. These cause the chromafin cells of the medulla to release adrenaline (which is preformed) by exocytosis. Adrenaline Fight or Flight response - Catecholamine (phenylalanine and tyrosine) - Neurotransmitter and hormone - Released by the adrenal glands - Effects on α 1 and 2, β 1 and 2 receptors - Effect on β 2 receptors in skeletal muscle vessels-causing vasodilation - Increase cardiac output and total peripheral resistance - Vasoconstriction in the skin and kidneys causing a narrow pulse pressure Actions α adrenergic receptors: Inhibits insulin secretion by the pancreas Stimulates glycogenolysis in the liver and muscle Stimulates glycolysis in muscle β adrenergic receptors: Stimulates glucagon secretion in the pancreas Stimulates ACTH Stimulates lipolysis by adipose tissue

Answer 886

Mnemonic for femoral nerve supply (don't) M I S V Q Scan for PE M edial cutaneous nerve of the thigh I ntermediate cutaneous nerve of the thigh S aphenous nerve V astus Q uadriceps femoris S artorius PE ectineus Adductor magnus is innervated by the obturator and sciatic nerve. The pectineus muscle is sometimes supplied by the obturator nerve but this is variable. Since the question states least likely, the correct answer is adductor magnus.

Answer 887

D-The superficial perineal pouch is a compartment bounded superficially by the superficial perineal fascia, deep by the perineal membrane (inferior fascia of the urogenital diaphragm), and laterally by the ischiopubic ramus. It contains the crura of the penis or clitoris, muscles, viscera, blood vessels, nerves, the proximal part of the spongy urethra in males, and the greater vestibular glands in females. When urethral rupture occurs as in this case the urine will tend to pass anteriorly because the fascial condensations will prevent lateral and posterior passage of the urine. Urogenital triangle The urogenital triangle is formed by the: Ischiopubic inferior rami Ischial tuberosities A fascial sheet is attached to the sides, forming the inferior fascia of the urogenital diaphragm. It transmits the urethra in males and both the urethra and vagina in females. The membranous urethra lies deep to this structure and is surrounded by the external urethral sphincter. Superficial to the urogenital diaphragm lies the superficial perineal pouch. In males this contains: Bulb of penis Crura of the penis Superficial transverse perineal muscle Posterior scrotal arteries Posterior scrotal nerves In females the internal pudendal artery branches to become the posterior labial arteries in the superficial perineal pouch.

Answer 888

Dorsally, the first interosseous occupies the space between the thumb and index finger. The tendon of the second inserts into the radial side of the extensor hood and proximal phalanx of the middle finger. The third and the fourth are inserted into the ulnar sides of the extensor hoods of the middle and ring fingers. Interossei Origin and insertion Nerve supply Actions Four palmar and four dorsal interossei occupy the spaces between the metacarpal bones. Each palmar interossei originates from the metacarpal of the digit on which it acts. Each dorsal interossei comes from the surface of the adjacent metacarpal on which it acts. As a result the dorsal interossei are twice the size of the palmar ones. The interossei tendons, except the first palmar, pass to one or other side of the metacarpophalangeal joint posterior to the deep transverse metacarpal ligament. They become inserted into the base of the proximal phalanx and partly into the extensor hood They are all innervated by the ulnar nerve Dorsal interossei abduct the fingers, palmar interossei adduct the fingers Clinical notes Along with the lumbricals the interossei flex the metacarpophalangeal joints and extend the proximal and distal interphalangeal joints. They are responsible for fine tuning these movements. When the interossei and lumbricals are paralysed the digits are pulled into hyperextension by extensor digitorum and a claw hand is seen.

Answer 889

Femoral triangle: Adductor longus medially Inguinal ligament superiorly Sartorius muscle laterally Adductor longus forms the medial border of the femoral triangle. It is closely related to the long saphenous vein which overlies it and the profunda branch of the femoral artery. The femoral nerve is related to it inferiorly. However, the tendon of iliacus inserts proximally and is not in contact with adductor longus. Adductor longus Origin Anterior body of pubis Insertion Middle third of linea aspera Action Adducts and flexes the thigh, medially rotate the hip Innervation Anterior division of obturator nerve (L2, L3, L4)

Answer 890

Pulmonary vessels develop from the sixth arch Embryological aortic arches - The aortic arches are a series of six paired embryological vascular structures which give rise to the great arteries of the neck and head. The first and second arches disappear early. A remnant of the 1st arch forms part of the maxillary artery. The external carotid buds from the horns of the aortic sac left behind by the regression of the first two arches. The third aortic arch constitutes the commencement of the internal carotid artery, and is therefore named the carotid arch. It contributes to the common carotid artery and the proximal portion of the internal carotid artery. The fourth right arch forms the right subclavian as far as the origin of its internal mammary branch. The fourth left arch forms the arch of the aorta between the origin of the left carotid artery and the termination of the ductus arteriosus. The fifth arch regresses or forms incompletely. The proximal part of the sixth right arch persists as the proximal part of the right pulmonary artery while the distal section degenerates; The sixth left arch gives off the left pulmonary artery and forms the ductus arteriosus.

Answer 891

Massive hemothorax results from the rapid accumulation of more than 1500 mL of blood or one third or more of the patients blood volume in the chest cavity. It is most commonly caused by a penetrating wound that disrupts the systemic or hilar vessels, although massive hemothorax can also result from blunt trauma. In massive haemothorax the neck veins are typically collapsed and the chest wall remains mobile. These features can help distinguish it from pneumothorax where the neck veins are distended. Penetrating thoracic trauma that is then followed by cardiac arrest in the department is an indication for ER thoracotomy. Thoracic trauma Key points related to thoracic trauma Less than 10% of blunt chest trauma and 15-30% of penetrating chest trauma requires operative intervention. The physiologic consequences of thoracic trauma are hypoxia, hypercarbia, and acidosis. Contusion, hematoma, and alveolar collapse, or changes in intrathoracic pressure relationships (e.g., tension pneumothorax and open pneumothorax) cause hypoxia and lead to metabolic acidosis. Hypercarbia causes respiratory acidosis and most often follows inadequate ventilation caused by changes in intrathoracic pressure relationships and depressed level of consciousness. Types of thoracic trauma Tension pneumothorax Often laceration to lung parenchyma with flap Pressure develops in thorax Most common cause is mechanical ventilation in patient with pleural injury Symptoms overlap with cardiac tamponade, hyper-resonant percussion note is more likely in tension pnemothorax Flail chest Chest wall disconnects from thoracic cage Multiple rib fractures (at least two fractures per rib in at least two ribs) Associated with pulmonary contusion Abnormal chest motion Avoid over hydration and fluid overload Pneumothorax Most common cause is lung laceration with air leakage Most traumatic pneumothoraces should have a chest drain Patients with traumatic pneumothorax should never be mechanically ventilated until a chest drain is inserted Haemothorax Most commonly due to laceration of lung, intercostal vessel or internal mammary artery Haemothoraces large enough to appear on CXR are treated with large bore chest drain Surgical exploration is warranted if >1500ml blood drained immediately Cardiac tamponade Beck's triad: elevated venous pressure, reduced arterial pressure, reduced heart sounds Pulsus paradoxus May occur with as little as 100ml blood Pulmonary contusion Most common potentially lethal chest injury Arterial blood gases and pulse oximetry important Early intubation within an hour if significant hypoxia Blunt cardiac injury Usually occurs secondary to chest wall injury ECG may show features of myocardial infarction Sequelae: hypotension, arrhythmias, cardiac wall motion abnormalities Aorta disruption Deceleration injuries Contained haematoma Widened mediastinum Diaphragm disruption Most due to motor vehicle accidents and blunt trauma causing large radial tears (laceration injuries result in small tears) More common on left side Insert gastric tube, may pass into intrathoracic stomach Mediastinal traversing wounds Entrance wound in one hemithorax and exit wound/foreign body in opposite hemithorax Mediastinal haematoma or pleural cap suggests great vessel injury Mortality is 20% References ATLS Manual 10th Edition. ISBN 78-0-9968262-3-5

Answer 892

In patients with major cardiac co-morbidities the safest option is to choose an axillo-bifemoral bypass graft. The long term patency rates are less good than with aorto-bifemoral bypass grafts, however, the operation is less major. Peripheral vascular disease Indications for surgery to revascularise the lower limb Intermittent claudication Critical ischaemia Ulceration Gangrene Intermittent claudication that is not disabling may provide a relative indication, whilst the other complaints are often absolute indications depending upon the frailty of the patient. Assessment Clinical examination Ankle brachial pressure index measurement Duplex arterial ultrasound Angiography (standard, CT or MRI): usually performed only if intervention being considered. Angioplasty In order for angioplasty to be undertaken successfully the artery has to be accessible. The lesion relatively short and reasonable distal vessel runoff. Longer lesions may be amenable to sub-intimal angioplasty. Surgery Surgery will be undertaken where attempts at angioplasty have either failed or are unsuitable. Bypass essentially involves bypassing the affected arterial segment by utilising a graft to run from above the disease to below the disease. As with angioplasty good runoff improves the outcome. Some key concepts with bypass surgery Superficial femoral artery occlusion to the above knee popliteal In the ideal scenario, vein (either in situ or reversed LSV) would be used as a conduit. However, prosthetic material has reasonable 5 year patency rates and some would advocate using this in preference to vein so that vein can be used for other procedures in the future. In general terms either technique is usually associated with an excellent outcome (if run off satisfactory). Procedure Artery dissected out, IV heparin 3,000 units given and then the vessels are cross clamped Longitudinal arteriotomy Graft cut to size and tunneled to arteriotomy sites Anastomosis to femoral artery usually with 5/0 'double ended' Prolene suture Distal anastomosis usually using 6/0 'double ended' Prolene Distal disease Femoro-distal bypass surgery takes longer to perform, is more technically challenging and has higher failure rates. In elderly diabetic patients with poor runoff a primary amputation may well be a safer and more effective option. There is no point in embarking on this type of surgery in patients who are wheelchair bound. In femorodistal bypasses vein gives superior outcomes to PTFE. Rules Vein mapping 1st to see whether there is suitable vein (the preferred conduit). Sub intimal hyperplasia occurs early when PTFE is used for the distal anastomosis and will lead to early graft occlusion and failure. Essential operative procedure as for above knee fem-pop. If there is insufficient vein for the entire conduit then vein can be attached to the end of the PTFE graft and then used for the distal anastomosis. This type of 'vein boot' is technically referred to as a Miller Cuff and is associated with better patency rates than PTFE alone. Remember the more distal the arterial anastomosis the lower the success rate. References Peach G et al. Diagnosis and management of peripheral arterial disease. BMJ 2012; 345: 36-41.

Answer 893

Paneth cells are secretory cells located in the crypts of Lieberkuhn. They are an important contributor to the gut microbiome and have roles in host defence and immunity. Gastrointestinal secretions Up to 7 litres of gastrointestinal secretions enter the lumen of the GI tract in a 24 hour period. The absorptive function of the small bowel is such that by the time a formed stool is created, it will contain, on average 200ml water. The common secretions together with their approximate volumes are demonstrated below: Origin of secretion Volume in ml / 24 hour period Na + mmol/L K+ mmol/L Cl-mmol/L HCO3 Salivary glands 1500 10 26 10 30 Stomach 1500 60 10 130 Duodenum 100-2000 140 80 80 Pancreas 1000 140 5 70 115 Bile 50-800 145 5 100 35 Jejunum/ileum 3000 140 10 104 30 Colon 100 60 30 40 The regulation of these secretions is dependent upon location. In the salivary glands a complex interaction of flow rate governed by the autonomic nervous system. The exact composition of sodium and potassium is regulated by aldosterone. In the stomach hormones such as gastrin play a role and feedback is both endocrine and neurologically mediated (vagus). In the duodenum CCK is released in response to duodenal distension and this causes contraction of the gallbladder and release of bile. Pancreatic secretions are affected by somatostatin. The secretions in the small bowel are affected by the osmolality of the lumenal contents. This is in part due to the tightness of cellular junctions and in this regard the jejunum is more permeable than the ileum. The practical implication of this is that if an individual has an extensive intestinal resection and a high output, proximally sited stoma then administration of hypotonic rather than isotonic solutions will result in worsening of electrolyte disturbances as electrolyte rich secretions will enter the jejunum. In some individuals a colectomy or similar procedure results in formation of an end or loop ileostomy. Ileostomies typically lose between 500 and 1000ml over a 24 hour period and patients with high output ileostomies can rapidly become dehydrated. Ileostomy effluent typically contains 126mmol/L of sodium and 22mmol/L of potassium. Knowledge of this fluid composition should guide fluid prescribing in replacing losses.

Answer 894

Beware of damaging the thoracodorsal trunk if a latissimus dorsi flap reconstruction is planned. The thoracodorsal trunk runs through the nodes in the axilla. If injured it may compromise the function and blood supply to latissimus dorsi, which is significant if it is to be used as a flap for a reconstructive procedure. Axilla Boundaries of the axilla Medially Chest wall and Serratus anterior Laterally Humeral head Floor Subscapularis Anterior aspect Lateral border of Pectoralis major Fascia Clavipectoral fascia Content: Long thoracic nerve (of Bell) Derived from C5-C7 and passes behind the brachial plexus to enter the axilla. It lies on the medial chest wall and supplies serratus anterior. Its location puts it at risk during axillary surgery and damage will lead to winging of the scapula. Thoracodorsal nerve and thoracodorsal trunk Innervate and vascularise latissimus dorsi. Axillary vein Lies at the apex of the axilla, it is the continuation of the basilic vein. Becomes the subclavian vein at the outer border of the first rib. Intercostobrachial nerves Traverse the axillary lymph nodes and are often divided during axillary surgery. They provide cutaneous sensation to the axillary skin. Lymph nodes The axilla is the main site of lymphatic drainage for the breast.

Answer 895

S2, 3, 4 Keeps the poo off the floor The external anal sphincter is innervated by the inferior rectal branch of the pudendal nerve, this has root values of S2, 3 and the perineal branch of S4. Anal sphincter Internal anal sphincter composed of smooth muscle continuous with the circular muscle of the rectum. It surrounds the upper two- thirds of the anal canal and is supplied by sympathetic nerves. External anal sphincter is composed of striated muscle which surrounds the internal sphincter but extends more distally. The nerve supply of the external anal sphincter is from the inferior rectal branch of the pudendal nerve (S2 and S3) and the perineal branch of the S4 nerve roots.

Answer 896

Bronchoconstriction Response to surgery Sympathetic nervous system Noradrenaline from sympathetic nerves and adrenaline from adrenal medulla Blood diverted from skin and visceral organs; bronchodilatation, reduced intestinal motility, increased glucagon and glycogenolysis, insulin reduced Heart rate and myocardial contractility are increased Acute phase response TNF-α, IL-1, IL-2, IL-6, interferon and prostaglandins are released Excess cytokines may cause SIRS Cytokines increase the release of acute phase proteins Endocrine response Hypothalamus, pituitary, adrenal axis Increases ACTH and cortisol production: increases protein breakdown increases blood glucose levels Aldosterone increases sodium re-absorption Vasopressin increases water re-absorption and causes vasoconstriction Vascular endothelium Nitric oxide produces vasodilatation Platelet activating factor enhances the cytokine response Prostaglandins produce vasodilatation and induce platelet aggregation

Answer 897

Samples of CSF are normally obtained by inserting a needle between the third and fourth lumbar vertebrae. The tip of the needle lies in the sub arachnoid space, the spinal cord terminates at L1 and is not at risk of injury. Clinical evidence of raised intracranial pressure is a contraindication to lumbar puncture. Cerebrospinal fluid The CSF fills the space between the arachnoid mater and pia mater (covering surface of the brain). The total volume of CSF in the brain is approximately 150ml. Approximately 500 ml is produced by the ependymal cells in the choroid plexus (70%), or blood vessels (30%). It is reabsorbed via the arachnoid granulations which project into the venous sinuses. Circulation 1. Lateral ventricles (via foramen of Munro) 2. 3rd ventricle 3. Cerebral aqueduct (aqueduct of Sylvius) 4. 4th ventricle 5. Subarachnoid space (via foramina of Magendie and Luschka) 6. Reabsorbed into the venous system via arachnoid granulations into superior sagittal sinus Composition Glucose: 50-80mg/dl Protein: 15-40 mg/dl Red blood cells: Nil White blood cells: 0-3 cells/ mm3

Answer 898

Injury to the ulnar nerve in the mid to distal forearm will typically produce a claw hand. This consists of flexion of the 4th and 5th interphalangeal joints and extension of the metacarpophalangeal joints. The effects are potentiated when flexor digitorum profundus is not affected, and the clawing is more pronounced.More proximally sited ulnar nerve lesions produce a milder clinical picture owing to the simultaneous paralysis of flexor digitorum profundus (ulnar half). This is the 'ulnar paradox', due to the more proximal level of transection the hand will typically not have a claw like appearance that may be seen following a more distal injury. The first dorsal interosseous muscle will be affected as it is supplied by the ulnar nerve. Ulnar nerve Origin C8, T1 Supplies (no muscles in the upper arm) Flexor carpi ulnaris Flexor digitorum profundus Flexor digiti minimi Abductor digiti minimi Opponens digiti minimi Adductor pollicis Interossei muscle Third and fourth lumbricals Palmaris brevis Path Posteromedial aspect of upper arm to flexor compartment of forearm, then along the ulnar. Passes beneath the flexor carpi ulnaris muscle, then superficially over the flexor retinaculum into the palm of the hand. Branches Branch Supplies Muscular branch Flexor carpi ulnaris Medial half of the flexor digitorum profundus Palmar cutaneous branch (Arises near the middle of the forearm) Skin on the medial part of the palm Dorsal cutaneous branch Dorsal surface of the medial part of the hand Superficial branch Cutaneous fibres to the anterior surfaces of the medial one and one-half digits Deep branch Hypothenar muscles All the interosseous muscles Third and fourth lumbricals Adductor pollicis Medial head of the flexor pollicis brevis Effects of injury Damage at the wrist Wasting and paralysis of intrinsic hand muscles (claw hand) Wasting and paralysis of hypothenar muscles Loss of sensation medial 1 and half fingers Damage at the elbow Radial deviation of the wrist Clawing less in 4th and 5th digits

Answer 899

Many of these events contribute to healing. However, platelet degranulation is the earliest phase and results in haemostasis, the main event is then allowing the release of cytokines to attract other cells types to the wound and co-ordinate healing. Phases of wound healing Phase Key features Cells Timeframe Haemostasis Vasospasm in adjacent vessels Platelet plug formation and generation of fibrin rich clot Erythrocytes and platelets Seconds/ Minutes Inflammation Neutrophils migrate into wound (function impaired in diabetes). Growth factors released, including basic fibroblast growth factor and vascular endothelial growth factor. Fibroblasts replicate within the adjacent matrix and migrate into wound. Macrophages and fibroblasts couple matrix regeneration and clot substitution. Neutrophils, fibroblasts and macrophages Days Regeneration Platelet derived growth factor and transformation growth factors stimulate fibroblasts and epithelial cells. Fibroblasts produce a collagen network. Angiogenesis occurs and wound resembles granulation tissue. Fibroblasts, endothelial cells, macrophages Weeks Remodelling Longest phase of the healing process and may last up to one year (or longer). During this phase fibroblasts become differentiated (myofibroblasts) and these facilitate wound contraction. Collagen fibres are remodelled. Microvessels regress leaving a pale scar. Myofibroblasts

Answer 900

Epidermis alone. This is the process of re-epithelialisation. Wound healing Surgical wounds are either incisional or excisional and either clean, clean contaminated or dirty. Although the stages of wound healing are broadly similar their contributions will vary according to the wound type. The main stages of wound healing include: Haemostasis Minutes to hours following injury Vasospasm in adjacent vessels, platelet plug formation and generation of fibrin rich clot. Inflammation Typically days 1-5 Neutrophils migrate into wound (function impaired in diabetes). Growth factors released, including basic fibroblast growth factor and vascular endothelial growth factor. Fibroblasts replicate within the adjacent matrix and migrate into wound. Macrophages and fibroblasts couple matrix regeneration and clot substitution. Regeneration Typically days 7 to 56 Platelet derived growth factor and transformation growth factors stimulate fibroblasts and epithelial cells. Fibroblasts produce a collagen network. Angiogenesis occurs and wound resembles granulation tissue. Remodeling From 6 weeks to 1 year Longest phase of the healing process and may last up to one year (or longer). During this phase fibroblasts become differentiated (myofibroblasts) and these facilitate wound contraction. Collagen fibres are remodeled. Microvessels regress leaving a pale scar. The above description represents an idealised scenario. A number of diseases may distort this process. Neovascularisation is an important early process. Endothelial cells may proliferate in the wound bed and recanalise to form a vessel. Vascular disease, shock and sepsis can all compromise microvascular flow and impair healing. Conditions such as jaundice will impair fibroblast synthetic function and immunity with a detrimental effect in most parts of the healing process. Problems with scars: Hypertrophic scars Excessive amounts of collagen within a scar. Nodules may be present histologically containing randomly arranged fibrils within and parallel fibres on the surface. The tissue itself is confined to the extent of the wound itself and is usually the result of a full thickness dermal injury. They may go on to develop contractures. Keloid scars Excessive amounts of collagen within a scar. Typically a keloid scar will pass beyond the boundaries of the original injury. They do not contain nodules and may occur following even trivial injury. They do not regress over time and may recur following removal. Drugs which impair wound healing: Non steroidal anti inflammatory drugs Steroids Immunosupressive agents Anti neoplastic drugs Closure Delayed primary closure is the anatomically precise closure that is delayed for a few days but before granulation tissue becomes macroscopically evident. Secondary closure refers to either spontaneous closure or to surgical closure after granulation tissue has formed.

Answer 901

The 15-month-old girl is a patient with nephrotic syndrome. Patients with this condition are at risk of septicaemia and peritonitis from Streptococcus pneumonia, due to the loss of immunoglobulins and opsonins in the urine.

Answer 902

Trapezius muscle. Posterior triangle of the neck Boundaries Apex Sternocleidomastoid and the Trapezius muscles at the Occipital bone Anterior Posterior border of the Sternocleidomastoid Posterior Anterior border of the Trapezius Base Middle third of the clavicle Contents Nerves Accessory nerve Phrenic nerve Three trunks of the brachial plexus Branches of the cervical plexus: Supraclavicular nerve, transverse cervical nerve, great auricular nerve, lesser occipital nerve Vessels External jugular vein Subclavian artery Muscles Inferior belly of omohyoid Scalene Lymph nodes Supraclavicular Occipital

Answer 903

D. Autonomic nerve injury is the most common cause. Nerve lesions during surgery A variety of different procedures carry the risk of iatrogenic nerve injury. These are important not only from the patients perspective but also from a medicolegal standpoint. The following operations and their associated nerve lesions are listed here: Posterior triangle lymph node biopsy and accessory nerve lesion. Lloyd Davies stirrups and common peroneal nerve. Thyroidectomy and laryngeal nerve. Anterior resection of rectum and hypogastric autonomic nerves. Axillary node clearance; long thoracic nerve, thoracodorsal nerve and intercostobrachial nerve. Inguinal hernia surgery and ilioinguinal nerve. Varicose vein surgery- sural and saphenous nerves. Posterior approach to the hip and sciatic nerve. Carotid endarterectomy and hypoglossal nerve. There are many more, with sound anatomical understanding of the commonly performed procedures the incidence of nerve lesions can be minimised. They commonly occur when surgeons operate in an unfamiliar tissue plane or by blind placement of haemostats (not recommended).

Answer 904

A. The fundus of the stomach is a posterior relation. The pylorus lies more inferolaterally. During a total gastrectomy division of the ligaments holding the left lobe of the liver will facilitate access to the proximal stomach and abdominal oesophagus. This manoeuvre is seldom beneficial during a distal gastrectomy. Liver Structure of the liver Right lobe Supplied by right hepatic artery Contains Couinaud segments V to VIII (-/+Sg I) Left lobe Supplied by the left hepatic artery Contains Couinaud segments II to IV (+/- Sg1) Quadrate lobe Part of the right lobe anatomically, functionally is part of the left Couinaud segment IV Porta hepatis lies behind On the right lies the gallbladder fossa On the left lies the fossa for the umbilical vein Caudate lobe Supplied by both right and left hepatic arteries Couinaud segment I Lies superior to the porta hepatis Anterior and medial to the inferior vena cava Bile from the caudate lobe drains into both right and left hepatic ducts Detailed knowledge of Couinaud segments is not required for MRCS Between the liver lobules are portal canals which contain the portal triad: Hepatic Artery, Portal Vein, tributary of Bile Duct. Relations of the liver Anterior Postero inferiorly Diaphragm Oesophagus Xiphoid process Stomach Duodenum Hepatic flexure of colon Right kidney Gallbladder Inferior vena cava Porta hepatis Location Postero inferior surface, it joins nearly at right angles with the left sagittal fossa, and separates the caudate lobe behind from the quadrate lobe in front Transmits Common hepatic duct Hepatic artery Portal vein Sympathetic and parasympathetic nerve fibres Lymphatic drainage of the liver (and nodes) Ligaments Falciform ligament 2 layer fold peritoneum from the umbilicus to anterior liver surface Contains ligamentum teres (remnant umbilical vein) On superior liver surface it splits into the coronary and left triangular ligaments Ligamentum teres Joins the left branch of the portal vein in the porta hepatis Ligamentum venosum Remnant of ductus venosus Arterial supply Hepatic artery Venous Hepatic veins Portal vein Nervous supply Sympathetic and parasympathetic trunks of coeliac plexus

Answer 905

Patients should have their Rockall score calculated following endoscopy for upper GI haemorrhage Mnemonic for Rockall score ABCDE A: Age B: Blood pressure drop (Shock) C: Co-morbidity D: Diagnosis E: Evidence of bleeding Rockall Score Applies to upper gastrointestinal bleeding Variable Score 0 Score 1 Score 2 Score 3 Age <60 60-79 >80 Shock None Pulse >100 Hypotension (systolic <100mmHg) Co-Morbidity Nil or minimal Major organ disease e.g. IHD, CCF Renal or liver failure, metastatic cancer Diagnosis Mallory-Weiss All GI Cancer Evidence of Bleeding None Clot, Blood, spurting vessel Score <3 = Good prognosis (mortality approx. 2%) Score >8= High mortality (Mortality approx. 40%) Upper gastrointestinal bleeding Patients may present with the following: Haematemesis and/ or malaena Epigastric discomfort Sudden collapse The extent to which these will occur will depend upon the source. Mortality is higher in patients presenting with haematemesis than malaena alone. Oesophageal bleeding Cause Presenting features Oesophagitis Small volume of fresh blood, often streaking vomit. Malaena rare. Often ceases spontaneously. Usually history of antecedent GORD type symptoms. Cancer Usually small volume of blood, except as pre terminal event with erosion of major vessels. Often associated symptoms of dysphagia and constitutional symptoms such as weight loss. May be recurrent until malignancy managed. Mallory Weiss Tear Typically brisk small to moderate volume of bright red blood following bout of repeated vomiting. Malaena rare. Usually ceases spontaneously. Varices Usually large volume of fresh blood. Swallowed blood may cause malaena. Often associated with haemodynamic compromise. May stop spontaneously but re-bleeds are common until appropriately managed. Gastric Bleeding Cause Presenting features Gastric cancer May be frank haematemesis or altered blood mixed with vomit. Usually prodromal features of dyspepsia and may have constitutional symptoms. Amount of bleeding variable but erosion of major vessel may produce considerable haemorrhage. Dieulafoy Lesion Often no prodromal features prior to haematemesis and malaena, but this arteriovenous malformation may produce quite considerable haemorrhage and may be difficult to detect endoscopically. Diffuse erosive gastritis Usually haematemesis and epigastric discomfort. Usually there is an underlying cause such as recent NSAID usage. Large volume haemorrhage may occur with considerable haemodynamic compromise. Gastric ulcer Small low volume bleeds more common so would tend to present as iron deficiency anaemia. Erosion into a significant vessel may produce considerable haemorrhage and haematemesis. Duodenum Most common cause of major haemorrhage is a posteriorly sited duodenal ulcer. However, ulcers at any site in the duodenum may present with haematemesis, malaena and epigastric discomfort. The pain of duodenal ulcer is slightly different to that of gastric ulcers and often occurs several hours after eating. Peri ampullary tumours may bleed but these are rare. In patients with previous abdominal aortic aneurysm surgery aorto-enteric fistulation remains a rare but important cause of major haemorrhage associated with high mortality. Management Admission to hospital careful monitoring, cross match blood, check FBC, LFTs, U+E and Clotting (as a minimum) Patients with on-going bleeding and haemodynamic instability are likely to require O negative blood pending cross matched blood Early control of airway is vital (e.g. Drowsy patient with liver failure) Patients with suspected varices should receive terlipressin prior to endoscopy Ideally all patients admitted with upper gastrointestinal haemorrhage should undergo Upper GI endoscopy within 24 hours of admission. In those who are unstable this should occur immediately after resuscitation or in tandem with it. The endoscopy department is a potentially dangerous place for unstable patients and it may be safer to perform the endoscopy in theatre with an anaesthetist present. Varices should be banded or subjected to sclerotherapy. If this is not possible owing to active bleeding then a Sengstaken- Blakemore tube (or Minnesota tube) should be inserted. This should be done with care; gastric balloon should be inflated first and oesophageal balloon second. Remember the balloon will need deflating after 12 hours (ideally sooner) to prevent necrosis. Portal pressure should be lowered by combination of medical therapy +/- TIPSS. Patients with erosive oesophagitis / gastritis should receive a proton pump inhibitor. Mallory Weiss tears will typically resolve spontaneously Identifiable bleeding points should receive combination therapy of injection of adrenaline and either a thermal or mechanical treatment. All who have received intervention should receive a continuous infusion of a proton pump inhibitor (IV omeprazole for 72 hours) to reduce the re-bleeding rate. Patients with diffuse erosive gastritis who cannot be managed endoscopically and continue to bleed may require gastrectomy Bleeding ulcers that cannot be controlled endoscopically may require laparotomy and ulcer underruning Indications for surgery Patients > 60 years Continued bleeding despite endoscopic intervention Recurrent bleeding Known cardiovascular disease with poor response to hypotension Surgery Duodenal ulcer Laparotomy, duodenotomy and under running of the ulcer. If bleeding is brisk then the ulcer is almost always posteriorly sited and will have invaded the gastroduodenal artery. Large bites using 0 Vicryl are taken above and below the ulcer base to occlude the vessel. The duodenotomy should be longitudinal but closed transversely to avoid stenosis. For gastric ulcer Under-running of the bleeding site Partial gastrectomy-antral ulcer Partial gastrectomy or under running the ulcer- lesser curve ulcer (involving left gastric artery) Total gastrectomy if bleeding persists Summary of Acute Upper GI bleeding recommendations: The need for admission and timing of endoscopic intervention may be predicted by using the Blatchford score. This considers a patients Hb, serum urea, pulse rate and blood pressure. Those patients with a score of 0 are low risk, all others are considered high risk and require admission and endoscopy. The requirement for pre endoscopic proton pump inhibition is contentious. In the UK the National Institute of Clinical Excellence guidelines suggest the pre endoscopic PPI therapy is unnecessary. Whilst it is accepted that such treatment has no impact on mortality or morbidity a Cochrane review of this practice in 2007 did suggest that it reduced the stigmata of recent haemorrhage at endoscopy. As a result many will still administer PPI to patients prior to endoscopic intervention. Following endoscopy it is important to calculate the Rockall score for patients to determine their risk of rebleeding and mortality. A score of 3 or less is associated with a rebleeding rate of 4% and a very low risk of mortality and identifies a group of patients suitable for early discharge. References 1. http://www.sign.ac.uk/guidelines/fulltext/105/index.html 2. Joint Advisory Group on Endoscopy (JAG) Guidelines - http://www.thejag.org.uk 3. NICE Guideline: Management of acute upper GI bleeding. July 2012.

Answer 906

This patient has an extensive disease process and lobular cancers are notorious for being multifocal. In this case a mastectomy is the safest next step. Radiotherapy is not appropriate in this setting as the margins are not clear. Breast cancer management - Surgery is performed in most patients suffering from breast cancer. Chemotherapy may be used to downstage tumours and allow breast conserving surgery. Hormonal therapy may also be used for the same purposes. Radiotherapy is given to most patients who have undergone breast conserving surgery (some older patients receiving hormone treatment and who have small low grade tumours may safely avoid DXT. Therapeutic mammoplasty is an option for some patients but requires symmetrizing surgery in most cases. Patients who have undergone mastectomy may be offered a reconstructive procedure either in conjunction with their primary resection or as a staged procedure at a later date. Surgical options Mastectomy vs Wide local excision Mastectomy Wide Local Excision Multifocal tumour Solitary lesion Central tumour Peripheral tumour Large lesion in small breast Small lesion in large breast DCIS >4cm DCIS <4cm Patient Choice Patient choice Central lesions may be managed using breast conserving surgery, where an acceptable cosmetic result may be obtained, this is rarely the case in small breasts Axillary disease As a minimum, all patients with invasive breast cancer should have their axilla staged. In those who do not have overt evidence of axillary nodal involvement this can be undertaken using sentinel lymph node biopsy. Patients with a positive sentinel lymph node biopsy or who have imaging and cytological or histological evidence of axillary nodal metastasis should undergo axillary node clearance or axillary irradiation. Axillary node clearance is associated with the development of lymphoedema, increased risk of cellulitis and frozen shoulder.

Answer 907

The posterior belly of digastric is innervated by the facial nerve and the anterior belly by the mylohoid nerve. Anterior triangle of the neck Boundaries Anterior border of the Sternocleidomastoid Lower border of mandible Anterior midline Sub triangles (divided by Digastric above and Omohyoid) Muscular triangle: Neck strap muscles Carotid triangle: Carotid sheath Submandibular Triangle (digastric) Contents of the anterior triangle Digastric triangle Submandibular gland Submandibular nodes Facial vessels Hypoglossal nerve Muscular triangle Strap muscles Jugular vein Carotid triangle Carotid sheath (Common carotid, vagus and internal jugular vein) Ansa cervicalis Nerve supply to digastric muscle Anterior: Mylohyoid nerve Posterior: Facial nerve

Answer 908

Vagotomy seriously compromises gastric emptying which is why either a pyloroplasty or gastro-enterostomy is routinely performed at the same time. Chloramphenicol has no effect on gastric emptying. Ondansetron slows gastric emptying slightly. Metoclopramide increases the rate of gastric emptying but its effects are mediated via the vagus nerve. Erythromycin enhances gastric emptying by acting via the motilin receptor in the gut. Gastric emptying The stomach serves both a mechanical and immunological function. Solid and liquid are retained in the stomach during which time repeated peristaltic activity against a closed pyloric sphincter will cause fragmentation of food bolus material. Contact with gastric acid will help to neutralise any pathogens present. The amount of time material spends in the stomach is related to its composition and volume. For example a glass of water will empty more quickly than a large meal. The presence of amino acids and fat will all serve to delay gastric emptying. Controlling factors Neuronal stimulation of the stomach is mediated via the vagus and the parasympathetic nervous system will tend to favor an increase in gastric motility. It is for this reason that individuals who have undergone truncal vagotomy will tend to routinely require either a pyloroplasty or gastro-enterostomy as they would otherwise have delayed gastric emptying. The following hormonal factors are all involved: Delay emptying Increase emptying Gastric inhibitory peptide Gastrin Cholecystokinin Enteroglucagon Diseases affecting gastric emptying All diseases that affect gastric emptying may result in bacterial overgrowth, retained food and eventually the formation of bezoars that may occlude the pylorus and make gastric emptying even worse. Fermentation of food may cause dyspepsia, reflux and foul smelling belches of gas. Iatrogenic Gastric surgery can have profound effects on gastric emptying. As stated above any procedure that disrupts the vagus can cause delayed emptying. Whilst this is particularly true of vagotomy, this operation is now rarely performed. Surgeons are divided on the importance of vagal disruption that occurs during an oesophagectomy, some will routinely perform a pyloroplasty and others will not. When a distal gastrectomy is performed, the type of anastomosis performed will impact on emptying. When a gastro-enterostomy is constructed, a posterior, retrocolic gastroenterostomy will empty better than an anterior one. Diabetic gastroparesis This is predominantly due to neuropathy affecting the vagus nerve. The stomach empties poorly and patients may have episodes of repeated and protracted vomiting. Diagnosis is made by upper GI endoscopy and contrast studies, in some cases a radio nucleotide scan is needed to demonstrate the abnormality more clearly. In treating these conditions, drugs such as metoclopramide will be less effective as they exert their effect via the vagus nerve. One of the few prokinetic drugs that do not work in this way is the antibiotic erythromycin. Malignancies Obviously a distal gastric cancer may obstruct the pylorus and delay emptying. In addition, malignancies of the pancreas may cause extrinsic compression of the duodenum and delay emptying. Treatment in these cases is by gastric decompression using a wide bore nasogastric tube and insertion of a stent or, if that is not possible, by a surgical gastroenterostomy. As a general rule gastroenterostomies constructed for bypass of malignancy are usually placed on the anterior wall of the stomach (in spite of the fact that they empty less well). A Roux en Y bypass may also be undertaken, but the increased number of anastomoses for this, in malignant disease that is being palliated, is probably not justified. Congenital Hypertrophic Pyloric Stenosis This is typically a disease of infancy. Most babies will present around 6 weeks of age with projectile non bile stained vomiting. It has an incidence of 2.4 per 1000 live births and is more common in males. Diagnosis is usually made by careful history and examination and a mass may be palpable in the epigastrium (often cited seldom felt!). The most important diagnostic test is an ultrasound that usually demonstrates the hypertrophied pylorus. Blood tests may reveal a hypochloraemic metabolic alkalosis if the vomiting is long standing. Once the diagnosis is made the infant is resuscitated and a pyloromyotomy is performed (either open or laparoscopically). Once treated there are no long term sequelae.

Answer 909

The inferior gluteal artery arises from the anterior trunk of the internal iliac artery The superior gluteal artery arises from the posterior trunk of the internal iliac artery Gluteal region Gluteal muscles Gluteus maximus: inserts to gluteal tuberosity of the femur and iliotibial tract Gluteus medius: attach to lateral greater trochanter Gluteus minimis: attach to anterior greater trochanter All extend and abduct the hip Deep lateral hip rotators Piriformis Gemelli Obturator internus Quadratus femoris Nerves Superior gluteal nerve (L4,L5, S1) Gluteus medius Gluteus minimis Tensor fascia lata Inferior gluteal nerve (L5, S1, S2) Gluteus maximus Damage to the superior gluteal nerve will result in the patient developing a Trendelenberg gait. Affected patients are unable to abduct the thigh at the hip joint. During the stance phase, the weakened abductor muscles allow the pelvis to tilt down on the opposite side. To compensate, the trunk lurches to the weakened side to attempt to maintain a level pelvis throughout the gait cycle. The pelvis sags on the opposite side of the lesioned superior gluteal nerve.

Answer 910

Posterior third tumours of the tongue commonly metastasise to the bilateral deep cervical lymph nodes Tumours of the posterior third of the tongue will typically metastasise early and bilateral nodal involvement is well recognised, this is most often true of centrally located tumours and those adjacent to the midline as the lymph vessels may cross the median plane at this location. Lymphatic drainage of the tongue - The lymphatic drainage of the anterior two thirds of the tongue shows only minimal communication of lymphatics across the midline, so metastasis to the ipsilateral nodes is usual. The lymphatic drainage of the posterior third of the tongue have communicating networks, as a result early bilateral nodal metastases are more common in this area. Lymphatics from the tip of the tongue usually pass to the sub mental nodes and from there to the deep cervical nodes. Lymphatics from the mid portion of the tongue usually drain to the submandibular nodes and then to the deep cervical nodes. Mid tongue tumours that are laterally located will usually drain to the ipsilateral deep cervical nodes, those from more central regions may have bilateral deep cervical nodal involvement.

Answer 911

Median nerve The median nerve is formed by the union of a lateral and medial root respectively from the lateral (C5,6,7) and medial (C8 and T1) cords of the brachial plexus; the medial root passes anterior to the third part of the axillary artery. The nerve descends lateral to the brachial artery, crosses to its medial side (usually passing anterior to the artery). It passes deep to the bicipital aponeurosis and the median cubital vein at the elbow. It passes between the two heads of the pronator teres muscle, and runs on the deep surface of flexor digitorum superficialis (within its fascial sheath). Near the wrist it becomes superficial between the tendons of flexor digitorum superficialis and flexor carpi radialis, deep to palmaris longus tendon. It passes deep to the flexor retinaculum to enter the palm, but lies anterior to the long flexor tendons within the carpal tunnel. Branches Region Branch Upper arm No branches, although the nerve commonly communicates with the musculocutaneous nerve Forearm Pronator teres Pronator quadratus Flexor carpi radialis Palmaris longus Flexor digitorum superficialis Flexor pollicis longus Flexor digitorum profundus (only the radial half) Distal forearm Palmar cutaneous branch Hand (Motor) Motor supply (LOAF) Lateral 2 lumbricals Opponens pollicis Abductor pollicis brevis Flexor pollicis brevis Hand (Sensory) Over thumb and lateral 2 Â½ fingers On the palmar aspect this projects proximally, on the dorsal aspect only the distal regions are innervated with the radial nerve providing the more proximal cutaneous innervation. Patterns of damage Damage at wrist e.g. carpal tunnel syndrome paralysis and wasting of thenar eminence muscles and opponens pollicis (ape hand deformity) sensory loss to palmar aspect of lateral (radial) 2 Â½ fingers Damage at elbow, as above plus: unable to pronate forearm weak wrist flexion ulnar deviation of wrist Anterior interosseous nerve (branch of median nerve) leaves just below the elbow results in loss of pronation of forearm and weakness of long flexors of thumb and index finger

Answer 912

She requires urgent decompression of her biliary system. An ERCP is the conventional method of performing this. It is important to ensure that her coagulation status is normalised prior to performing this procedure. Management of Pancreatitis Management of Acute Pancreatitis in the UK Diagnosis Traditionally hyperamylasaemia has been utilised with amylase being elevated three times the normal range. However, amylase may give both false positive and negative results. Serum lipase is both more sensitive and specific than serum amylase. It also has a longer half life. Serum amylase levels do not correlate with disease severity. Differential causes of hyperamylasaemia Acute pancreatitis Pancreatic pseudocyst Mesenteric infarct Perforated viscus Acute cholecystitis Diabetic ketoacidosis Assessment of severity Glasgow, Ranson scoring systems and APACHE II Biochemical scoring e.g. using CRP Features that may predict a severe attack within 48 hours of admission to hospital Initial assessment Clinical impression of severity Body mass index >30 Pleural effusion APACHE score >8 24 hours after admission Clinical impression of severity APACHE II >8 Glasgow score of 3 or more Persisting multiple organ failure CRP>150 48 hours after admission Glasgow Score of >3 CRP >150 Persisting or progressive organ failure Table adapted from UK guidelines for management of acute pancreatitis. GUT 2005, 54 suppl III Management Nutrition There is reasonable evidence to suggest that the use of enteral nutrition does not worsen the outcome in pancreatitis Most trials to date were underpowered to demonstrate a conclusive benefit. The rationale behind feeding is that it helps to prevent bacterial translocation from the gut, thereby contributing to the development of infected pancreatic necrosis. Use of antibiotic therapy Many UK surgeons administer antibiotics to patients with acute pancreatitis. However, there is very little evidence to support this practice. A recent Cochrane review highlights the potential benefits of administering Imipenem to patients with established pancreatic necrosis in the hope of averting the progression to infection. There are concerns that the administration of antibiotics in mild attacks of pancreatitis will not affect outcome and may contribute to antibiotic resistance and increase the risks of antibiotic associated diarrhoea. Surgery Patients with acute pancreatitis due to gallstones should undergo early cholecystectomy. Patients with obstructed biliary system due to stones should undergo early ERCP. Patients with extensive necrosis where infection is suspected should usually undergo FNA for culture. Patients with infected necrosis should undergo either radiological drainage or surgical necrosectomy. The choice of procedure depends upon local expertise. References www.bsg.org.uk/pdfworddocs/pancreatic.pdf Antibiotic therapy for prophylaxis against infection of pancreatic necrosis in acute pancreatitis. Villatoro et al. Cochrane Library DOI: 10.1002/14651858.CD002941.pub3. 2010 version.

Answer 913

n the middle of the forearm, the artery is overlapped by the flexor carpi ulnaris and on the flexor retinaculum it is covered by a superficial layer from that structure. In its distal two-thirds, flexor digitorum superficialis lies on its radial side, and the ulnar nerve is situated on its ulnar side. Ulnar artery Path Starts: middle of antecubital fossa Passes obliquely downward, reaching the ulnar side of the forearm at a point about midway between the elbow and the wrist. It follows the ulnar border to the wrist, crossing over the flexor retinaculum. It then divides into the superficial and deep volar arches. Relations Deep to- Pronator teres, Flexor carpi ulnaris, Palmaris longus Lies on- Brachialis and Flexor digitorum profundus Superficial to the flexor retinaculum at the wrist The median nerve is in relation with the medial side of the artery for about 2.5 cm. And then crosses the vessel, being separated from it by the ulnar head of the Pronator teres The ulnar nerve lies medially to the lower two-thirds of the artery Branch Anterior interosseous artery

Answer 914

Glioblastoma multiforme is rare in childhood. In contrast, astrocytoma is the commonest brain tumour in children. Medulloblastoma is no longer the commonest CNS tumour in children (Cancer research UK) CNS tumours 60% = Glioma and metastatic disease 20% = Meningioma 10% = Pituitary lesions In paediatric practice medulloblastomas (neuroectodermal tumours) were the commonest lesions, astrocytomas now account for the majority. Tumours arising in right temporal and frontal lobe may reach considerable size before becoming symptomatic. Whereas tumours in the speech and visual areas will typically produce early symptoms. Most paediatric CNS tumours are infratentorial Most adult CNS tumours are supratentorial Diagnosis MRI Scanning provides the best resolution. Treatment Usually surgery, even if tumour cannot be completely resected conditions such as rising ICP can be addressed with tumour debulking and survival and quality of life prolonged. Curative surgery can usually be undertaken with lesions such as meningiomas. Gliomas have a marked propensity to invade normal brain and resection of these lesions is nearly always incomplete.

Answer 915

Calcium phosphate stones are the most radiodense stones, calcium oxalate stones slightly less so. Uric acid stones are radiolucent (unless they have calcium contained within them). Renal stones Type of stones Features Percentage of all calculi Calcium oxalate Hypercalciuria is a major risk factor (various causes) Hyperoxaluria may also increase risk Hypocitraturia increases risk because citrate forms complexes with calcium making it more soluble Stones are radio-opaque (though less than calcium phosphate stones) Hyperuricosuria may cause uric acid stones to which calcium oxalate binds 85% Cystine Inherited recessive disorder of transmembrane cystine transport leading to decreased absorption of cystine from intestine and renal tubule Multiple stones may form Relatively radiodense because they contain sulphur 1% Uric acid Uric acid is a product of purine metabolism May precipitate when urinary pH low May be caused by diseases with extensive tissue breakdown e.g. malignancy More common in children with inborn errors of metabolism Radiolucent 5-10% Calcium phosphate May occur in renal tubular acidosis, high urinary pH increases supersaturation of urine with calcium and phosphate Renal tubular acidosis types 1 and 3 increase risk of stone formation (types 2 and 4 do not) Radio-dense stones (composition similar to bone) 10% Struvite Stones formed from magnesium, ammonium and phosphate Occur as a result of urease producing bacteria (and are thus associated with chronic infections) Under the alkaline conditions produced, the crystals can precipitate Slightly radio-opaque 2-20% Effect of urinary pH on stone formation Urine pH will show individual variation (from pH 5-7). Post prandially the pH falls as purine metabolism will produce uric acid. Then the urine becomes more alkaline (alkaline tide). When the stone is not available for analysis the pH of urine may help to determine which stone was present. Stone type Urine acidity Mean urine pH Calcium phosphate Normal- alkaline >5.5 Calcium oxalate Variable 6 Uric acid Acid 5.5 Struvite Alkaline >7.2 Cystine Normal 6.5

Answer 916

From superficial to deep: The common peroneal nerve exits the popliteal fossa along the medial border of the biceps tendon. Then the tibial nerve lies lateral to the popliteal vessels to pass posteriorly and then medially to them. The popliteal vein lies superficial to the popliteal artery, which is the deepest structure in the fossa. Popliteal fossa Boundaries of the popliteal fossa Laterally Biceps femoris above, lateral head of gastrocnemius and plantaris below Medially Semimembranosus and semitendinosus above, medial head of gastrocnemius below Floor Popliteal surface of the femur, posterior ligament of knee joint and popliteus muscle Roof Superficial and deep fascia Contents Popliteal artery and vein Small saphenous vein Common peroneal nerve Tibial nerve Posterior cutaneous nerve of the thigh Genicular branch of the obturator nerve Lymph nodes

Answer 917

The classical LFS malignancies - sarcoma, cancers of the breast, brain and adrenal glands - comprise about 80% of all cancers that occur in this syndrome. They are at high risk of developing leukaemia. Genetics and surgical disease Some of the more commonly occurring genetic conditions occurring in surgical patients are presented here. Li-Fraumeni Syndrome Autosomal dominant Consists of germline mutations to p53 tumour suppressor gene High incidence of malignancies particularly sarcomas and leukaemias Diagnosed when: *Individual develops sarcoma under 45 years *First degree relative diagnosed with any cancer below age 45 years and another family member develops malignancy under 45 years or sarcoma at any age BRCA 1 and 2 Carried on chromosome 17 (BRCA 1) and Chromosome 13 (BRCA 2) Linked to developing breast cancer (60%) risk. Associated risk of developing ovarian cancer (55% with BRCA 1 and 25% with BRCA 2). Lynch Syndrome Autosomal dominant Develop colonic cancer and endometrial cancer at young age 80% of affected individuals will get colonic and/ or endometrial cancer High risk individuals may be identified using the Amsterdam criteria Amsterdam criteria Three or more family members with a confirmed diagnosis of colorectal cancer, one of whom is a first degree (parent, child, sibling) relative of the other two. Two successive affected generations. One or more colon cancers diagnosed under age 50 years. Familial adenomatous polyposis (FAP) has been excluded. Gardners syndrome Autosomal dominant familial colorectal polyposis Multiple colonic polyps Extra colonic diseases include: skull osteoma, thyroid cancer and epidermoid cysts Desmoid tumours are seen in 15% Mutation of APC gene located on chromosome 5 Due to colonic polyps most patients will undergo colectomy to reduce risk of colorectal cancer Now considered a variant of familial adenomatous polyposis coli

Answer 918

Incompletely excised BCC have upwards of 30% recurrence rates. Systemic spread with these lesions is rare and it is usually local recurrence that is the main problem. Skin disorders in surgery- malignancy and related lesions Non melanoma skin cancer (BCC and SCC) are some of the commonest types of human malignancy. Up to 80% of these are BCC's with approximately 20% comprising SCC's. The incidence of NMSC's increases with age and whilst there is a female preponderance in those under 40 years of age, in latter life the sex incidence is roughly equal. The vast majority of NMSC's are related to UV light exposure. For SCC's the major pattern is in chronic long term exposure. For BCC's, the pattern of sporadic exposure with episodes of burning is more important. Organ transplant recipients have a markedly increased incidence of SCC, risk factors include length of immunosuppression, ethnic origin and associated sunlight exposure. Human papilloma virus DNA is found in the majority of transplant recipient SCC's. In addition to this increased risk, transplant recipients are also more likely to develop locoregional recurrences following treatment. Actinic keratosis and SCC Actinic keratosis is viewed as a premalignant lesion because there are atypical keratinocytes present in the epidermis. In a person with 7 actinic keratosis the risks of subsequent SCC is of the order of 10% at 10 years. The primary lesion is a rough erythematous papule with a white to yellow scale. Lesions are typically clustered at sites of chronic sun exposure. Squamous cell carcinoma in situ Also known as Bowens disease the commonest presentation of in situ SCC is with an erythematous scaling patch or elevated plaque arising on sun exposed skin in an elderly patient. Lesions may arise de novo or from pre-existing actinic keratosis. Pathologically there is full thickness atypia of dermal keratinocytes over a broad zone. Nuclear pleomorphism, apoptosis and abnormal mitoses are all seen. Invasive SCC The commonest clinical presentation of SCC is with an erythematous keratotic papule or nodule on a background of sun exposure. Ulceration may occur and both exophytic and endophytic areas may be seen. Regional lymphadenopathy may be present. Pathologically there is downward proliferation of malignant cells and invasion of the basement membrane. Poorly differentiated lesions may show perineural invasion and require immunohistochemistry with S100 to distinguish them from melanomas (which stain strongly positive with this marker). Basal cell carcinoma Nodular BCC Commonest variant (60%) Raised translucent papule Usually affect the face Large nodular BCC's are locally destructive Superficial BCC Usually appears as superficial erythematous macule affecting the trunk Younger age at presentation (mean 57) May show areas of spontaneous regression Horizontal growth pattern predominates High recurrence rate (due to sub clinical lateral spread) Morpheaform BCC Macroscopically resembles flat, slightly atrophic lesion or plaque without well defined borders Tumour has sub clinical lateral spread which increases recurrence rates Cystic BCC Often have clear or blue - grey appearance Cystic degeneration may not be clinically obvious and tumour may resemble nodular BCC Basosquamous carcinoma Atypical BCC Basaloid histological BCC features with eosinophillic squamoid features of SCC Biologically more aggressive and are more locally destructive Rare lesion accounts for 1% of all non melanoma skin cancers Metastatic disease may occur in 9-10% of cases and resemble an SCC Keratoacanthoma Dome shaped erythematous lesions that develop over a period of days and grow rapidly. They often contain a central pit of keratin. They then begin to necrose and slough off. They are generally benign lesions although some do view them as precursors of malignancy. They may be treated by curettage and cautery. If there is diagnostic doubt (they can mimic malignancy) then formal excision biopsy is warranted. Pyogenic granuloma These present as friable overgrowths of granulation at sites of minor trauma. They may be ulcerated and bleeding on contact is common. They may be treated with curretage and cautery, formal excision may be used if there is diagnostic doubt.

Answer 919

C-Usual history of regurgitation of undigested food or coughing at night. Associated with halitosis and throat infections. Neck lumps The table below gives characteristic exam question features for conditions causing neck lumps: Reactive lymphadenopathy By far the most common cause of neck swellings. There may be a history of local infection or a generalised viral illness Lymphoma Rubbery, painless lymphadenopathy The phenomenon of pain whilst drinking alcohol is very uncommon There may be associated night sweats and splenomegaly Thyroid swelling May be hypo-, eu- or hyperthyroid symptomatically Moves upwards on swallowing Thyroglossal cyst More common in patients < 20 years old Usually midline, between the isthmus of the thyroid and the hyoid bone Moves upwards with protrusion of the tongue May be painful if infected Pharyngeal pouch More common in older men Represents a posteromedial herniation between thyropharyngeus and cricopharyngeus muscles Usually not seen, but if large then a midline lump in the neck that gurgles on palpation Typical symptoms are dysphagia, regurgitation, aspiration and chronic cough Cystic hygroma A congenital lymphatic lesion (lymphangioma) typically found in the neck, classically on the left side Most are evident at birth, around 90% present before 2 years of age Branchial cyst An oval, mobile cystic mass that develops between the sternocleidomastoid muscle and the pharynx Develop due to failure of obliteration of the second branchial cleft in embryonic development Usually present in early adulthood Cervical rib More common in adult females Around 10% develop thoracic outlet syndrome Carotid aneurysm Pulsatile lateral neck mass which doesn't move on swallowing

Answer 920

Rickets is the childhood form of osteomalacia. It is due to the failure of the osteoid to ossify due to vitamin D deficiency. Symptoms start about the age of one. The child is small for age and there is a history of failure to thrive. Bony deformities include bowing of the femur and tibia, a large head, deformity of the chest wall with thickening of the costochondral junction (rickettary rosary), and a transverse sulcus in the chest caused by the pull of the diaphragm (Harrison's sulcus). X- Rays show widening and cupping of the epiphysis of the long bones, most readily apparent in the wrist. Paediatric fractures Paediatric fracture types Type Injury pattern Complete fracture Both sides of cortex are breached Toddlers fracture Oblique tibial fracture in infants Plastic deformity Stress on bone resulting in deformity without cortical disruption Greenstick fracture Unilateral cortical breach only Buckle fracture Incomplete cortical disruption resulting in periosteal haematoma only Growth plate fractures In paediatric practice fractures may also involve the growth plate and these injuries are classified according to the Salter- Harris system (given below): Type Injury pattern I Fracture through the physis only (x-ray often normal) II Fracture through the physis and metaphysis III Fracture through the physis and epiphyisis to include the joint IV Fracture involving the physis, metaphysis and epiphysis V Crush injury involving the physis (x-ray may resemble type I, and appear normal) As a general rule it is safer to assume that growth plate tenderness is indicative of an underlying fracture even if the x-ray appears normal. Injuries of Types III, IV and V will usually require surgery. Type V injuries are often associated with disruption to growth. Non accidental injury Delayed presentation Delay in attaining milestones Lack of concordance between proposed and actual mechanism of injury Multiple injuries Injuries at sites not commonly exposed to trauma Children on the at risk register Pathological fractures Genetic conditions, such as osteogenesis imperfecta, may cause pathological fractures. Osteogenesis imperfecta Defective osteoid formation due to congenital inability to produce adequate intercellular substances like osteoid, collagen and dentine. Failure of maturation of collagen in all the connective tissues. Radiology may show translucent bones, multiple fractures, particularly of the long bones, wormian bones (irregular patches of ossification) and a trefoil pelvis. Subtypes Type I The collagen is normal quality but insufficient quantity. Type II- Poor collagen quantity and quality. Type III- Collagen poorly formed. Normal quantity. Type IV- Sufficient collagen quantity but poor quality. Osteopetrosis Bones become harder and more dense. Autosomal recessive condition. It is commonest in young adults. Radiology reveals a lack of differentiation between the cortex and the medulla described as marble bone.

Answer 921

Parietal cells are responsible for the release of gastric acid. Brunners glands are found in the duodenum. Gastric secretions A working knowledge of gastric secretions is important for surgery because peptic ulcers are common, surgeons frequently prescribe anti secretory drugs and because there are still patients around who will have undergone acid lowering procedures (Vagotomy) in the past. Gastric acid Is produced by the parietal cells in the stomach pH of gastric acid is around 2 with acidity being maintained by the H+/K+ ATP ase pump. As part of the process bicarbonate ions will be secreted into the surrounding vessels. Sodium and chloride ions are actively secreted from the parietal cell into the canaliculus. This sets up a negative potential across the membrane and as a result sodium and potassium ions diffuse across into the canaliculus. Carbonic anhydrase forms carbonic acid which dissociates and the hydrogen ions formed by dissociation leave the cell via the H+/K+ antiporter pump. At the same time sodium ions are actively absorbed. This leaves hydrogen and chloride ions in the canaliculus these mix and are secreted into the lumen of the oxyntic gland. Phases of gastric acid secretion There are 3 phases of gastric secretion: 1. Cephalic phase (smell / taste of food) 30% acid produced Vagal cholinergic stimulation causing secretion of HCL and gastrin release from G cells 2. Gastric phase (distension of stomach ) 60% acid produced Stomach distension/low H+/peptides causes Gastrin release 3. Intestinal phase (food in duodenum) 10% acid produced High acidity/distension/hypertonic solutions in the duodenum inhibits gastric acid secretion via enterogastrones (CCK, secretin) and neural reflexes. Regulation of gastric acid production Factors increasing production include: Vagal nerve stimulation Gastrin release Histamine release (indirectly following gastrin release) from enterchromaffin like cells Factors decreasing production include: Somatostatin (inhibits histamine release) Cholecystokinin Secretin Below is a brief summary of the major hormones involved in food digestion: Source Stimulus Actions Gastrin G cells in antrum of the stomach Distension of stomach, extrinsic nerves Inhibited by: low antral pH, somatostatin Increase HCL, pepsinogen and IF secretion, increases gastric motility, trophic effect on gastric mucosa CCK I cells in upper small intestine Partially digested proteins and triglycerides Increases secretion of enzyme-rich fluid from pancreas, contraction of gallbladder and relaxation of sphincter of Oddi, decreases gastric emptying, trophic effect on pancreatic acinar cells, induces satiety Secretin S cells in upper small intestine Acidic chyme, fatty acids Increases secretion of bicarbonate-rich fluid from pancreas and hepatic duct cells, decreases gastric acid secretion, trophic effect on pancreatic acinar cells VIP Small intestine, pancreas Neural Stimulates secretion by pancreas and intestines, inhibits acid and pepsinogen secretion Somatostatin D cells in the pancreas and stomach Fat, bile salts and glucose in the intestinal lumen Decreases acid and pepsin secretion, decreases gastrin secretion, decreases pancreatic enzyme secretion, decreases insulin and glucagon secretion inhibits trophic effects of gastrin, stimulates gastric mucous production

Answer 922

Extensor hallucis longus is derived from L5 and loss of EHL function is a useful test to determine whether this level is involved. Spinal cord - Located in a canal within the vertebral column that affords it structural support. Rostrally it continues to the medulla oblongata of the brain and caudally it tapers at a level corresponding to the L1-2 interspace (in the adult), a central structure, the filum terminale anchors the cord to the first coccygeal vertebra. The spinal cord is characterised by cervico-lumbar enlargements and these, broadly speaking, are the sites which correspond to the brachial and lumbar plexuses respectively. There are some key points to note when considering the surgical anatomy of the spinal cord: * During foetal growth the spinal cord becomes shorter than the spinal canal, hence the adult site of cord termination at the L1-2 level. * Due to growth of the vertebral column the spine segmental levels may not always correspond to bony landmarks as they do in the cervical spine. * The spinal cord is incompletely divided into two symmetrical halves by a dorsal median sulcus and ventral median fissure. Grey matter surrounds a central canal that is continuous rostrally with the ventricular system of the CNS. * The grey matter is sub divided cytoarchitecturally into Rexeds laminae. * Afferent fibres entering through the dorsal roots usually terminate near their point of entry but may travel for varying distances in Lissauers tract. In this way they may establish synaptic connections over several levels * At the tip of the dorsal horn are afferents associated with nociceptive stimuli. The ventral horn contains neurones that innervate skeletal muscle. The key point to remember when revising CNS anatomy is to keep a clinical perspective in mind. So it is worth classifying the ways in which the spinal cord may become injured. These include: Trauma either direct or as a result of disc protrusion Neoplasia either by direct invasion (rare) or as a result of pathological vertebral fracture Inflammatory diseases such as Rheumatoid disease, or OA (formation of osteophytes compressing nerve roots etc. Vascular either as a result of stroke (rare in cord) or as complication of aortic dissection Infection historically diseases such as TB, epidural abscesses. The anatomy of the cord will, to an extent dictate the clinical presentation. Some points/ conditions to remember: Brown- Sequard syndrome-Hemisection of the cord producing ipsilateral loss of proprioception and upper motor neurone signs, plus contralateral loss of pain and temperature sensation. The explanation of this is that the fibres decussate at different levels. Lesions below L1 will tend to present with lower motor neurone signs

Answer 923

The middle colonic vein drains into the SMV, if avulsed during mobilisation then dramatic haemorrhage can occur and be difficult to control. Transverse colon The right colon undergoes a sharp turn at the level of the hepatic flexure to become the transverse colon. At this point it also becomes intraperitoneal. It is connected to the inferior border of the pancreas by the transverse mesocolon. The greater omentum is attached to the superior aspect of the transverse colon from which it can easily be separated. The mesentery contains the middle colic artery and vein. The greater omentum remains attached to the transverse colon up to the splenic flexure. At this point the colon undergoes another sharp turn. Relations Superior Liver and gall-bladder, the greater curvature of the stomach, and the lower end of the spleen Inferior Small intestine Anterior Greater omentum Posterior From right to left with the descending portion of the duodenum, the head of the pancreas, convolutions of the jejunum and ileum, spleen

Answer 924

This is a case of Kartagener's syndrome. The primary problem is of immotile cilia syndrome. When associated with situs inversus Kartagener's syndrome is diagnosed. Genetics and surgical disease Some of the more commonly occurring genetic conditions occurring in surgical patients are presented here. Li-Fraumeni Syndrome Autosomal dominant Consists of germline mutations to p53 tumour suppressor gene High incidence of malignancies particularly sarcomas and leukaemias Diagnosed when: *Individual develops sarcoma under 45 years *First degree relative diagnosed with any cancer below age 45 years and another family member develops malignancy under 45 years or sarcoma at any age BRCA 1 and 2 Carried on chromosome 17 (BRCA 1) and Chromosome 13 (BRCA 2) Linked to developing breast cancer (60%) risk. Associated risk of developing ovarian cancer (55% with BRCA 1 and 25% with BRCA 2). Lynch Syndrome Autosomal dominant Develop colonic cancer and endometrial cancer at young age 80% of affected individuals will get colonic and/ or endometrial cancer High risk individuals may be identified using the Amsterdam criteria Amsterdam criteria Three or more family members with a confirmed diagnosis of colorectal cancer, one of whom is a first degree (parent, child, sibling) relative of the other two. Two successive affected generations. One or more colon cancers diagnosed under age 50 years. Familial adenomatous polyposis (FAP) has been excluded. Gardners syndrome Autosomal dominant familial colorectal polyposis Multiple colonic polyps Extra colonic diseases include: skull osteoma, thyroid cancer and epidermoid cysts Desmoid tumours are seen in 15% Mutation of APC gene located on chromosome 5 Due to colonic polyps most patients will undergo colectomy to reduce risk of colorectal cancer Now considered a variant of familial adenomatous polyposis coli

Answer 925

Greenstick fractures are common childhood injuries. Unilateral cortical disruption is the main radiological feature, since involvement of both cortices makes the injury a complete fracture. Buckle fractures will show periosteal haematoma formation only. Paediatric fractures Paediatric fracture types Type Injury pattern Complete fracture Both sides of cortex are breached Toddlers fracture Oblique tibial fracture in infants Plastic deformity Stress on bone resulting in deformity without cortical disruption Greenstick fracture Unilateral cortical breach only Buckle fracture Incomplete cortical disruption resulting in periosteal haematoma only Growth plate fractures In paediatric practice fractures may also involve the growth plate and these injuries are classified according to the Salter- Harris system (given below): Type Injury pattern I Fracture through the physis only (x-ray often normal) II Fracture through the physis and metaphysis III Fracture through the physis and epiphyisis to include the joint IV Fracture involving the physis, metaphysis and epiphysis V Crush injury involving the physis (x-ray may resemble type I, and appear normal) As a general rule it is safer to assume that growth plate tenderness is indicative of an underlying fracture even if the x-ray appears normal. Injuries of Types III, IV and V will usually require surgery. Type V injuries are often associated with disruption to growth. Non accidental injury Delayed presentation Delay in attaining milestones Lack of concordance between proposed and actual mechanism of injury Multiple injuries Injuries at sites not commonly exposed to trauma Children on the at risk register Pathological fractures Genetic conditions, such as osteogenesis imperfecta, may cause pathological fractures. Osteogenesis imperfecta Defective osteoid formation due to congenital inability to produce adequate intercellular substances like osteoid, collagen and dentine. Failure of maturation of collagen in all the connective tissues. Radiology may show translucent bones, multiple fractures, particularly of the long bones, wormian bones (irregular patches of ossification) and a trefoil pelvis. Subtypes Type I The collagen is normal quality but insufficient quantity. Type II- Poor collagen quantity and quality. Type III- Collagen poorly formed. Normal quantity. Type IV- Sufficient collagen quantity but poor quality. Osteopetrosis Bones become harder and more dense. Autosomal recessive condition. It is commonest in young adults. Radiology reveals a lack of differentiation between the cortex and the medulla described as marble bone.

Answer 926

Keratoacanthomas are characterised by a rapid growth phase. This may mimic amelanotic melanoma (although such rapid growth is rare even in these lesions). The keratin core is the clue as to the true nature of the lesion. Skin disorders in surgery- malignancy and related lesions Non melanoma skin cancer (BCC and SCC) are some of the commonest types of human malignancy. Up to 80% of these are BCC's with approximately 20% comprising SCC's. The incidence of NMSC's increases with age and whilst there is a female preponderance in those under 40 years of age, in latter life the sex incidence is roughly equal. The vast majority of NMSC's are related to UV light exposure. For SCC's the major pattern is in chronic long term exposure. For BCC's, the pattern of sporadic exposure with episodes of burning is more important. Organ transplant recipients have a markedly increased incidence of SCC, risk factors include length of immunosuppression, ethnic origin and associated sunlight exposure. Human papilloma virus DNA is found in the majority of transplant recipient SCC's. In addition to this increased risk, transplant recipients are also more likely to develop locoregional recurrences following treatment. Actinic keratosis and SCC Actinic keratosis is viewed as a premalignant lesion because there are atypical keratinocytes present in the epidermis. In a person with 7 actinic keratosis the risks of subsequent SCC is of the order of 10% at 10 years. The primary lesion is a rough erythematous papule with a white to yellow scale. Lesions are typically clustered at sites of chronic sun exposure. Squamous cell carcinoma in situ Also known as Bowens disease the commonest presentation of in situ SCC is with an erythematous scaling patch or elevated plaque arising on sun exposed skin in an elderly patient. Lesions may arise de novo or from pre-existing actinic keratosis. Pathologically there is full thickness atypia of dermal keratinocytes over a broad zone. Nuclear pleomorphism, apoptosis and abnormal mitoses are all seen. Invasive SCC The commonest clinical presentation of SCC is with an erythematous keratotic papule or nodule on a background of sun exposure. Ulceration may occur and both exophytic and endophytic areas may be seen. Regional lymphadenopathy may be present. Pathologically there is downward proliferation of malignant cells and invasion of the basement membrane. Poorly differentiated lesions may show perineural invasion and require immunohistochemistry with S100 to distinguish them from melanomas (which stain strongly positive with this marker). Basal cell carcinoma Nodular BCC Commonest variant (60%) Raised translucent papule Usually affect the face Large nodular BCC's are locally destructive Superficial BCC Usually appears as superficial erythematous macule affecting the trunk Younger age at presentation (mean 57) May show areas of spontaneous regression Horizontal growth pattern predominates High recurrence rate (due to sub clinical lateral spread) Morpheaform BCC Macroscopically resembles flat, slightly atrophic lesion or plaque without well defined borders Tumour has sub clinical lateral spread which increases recurrence rates Cystic BCC Often have clear or blue - grey appearance Cystic degeneration may not be clinically obvious and tumour may resemble nodular BCC Basosquamous carcinoma Atypical BCC Basaloid histological BCC features with eosinophillic squamoid features of SCC Biologically more aggressive and are more locally destructive Rare lesion accounts for 1% of all non melanoma skin cancers Metastatic disease may occur in 9-10% of cases and resemble an SCC Keratoacanthoma Dome shaped erythematous lesions that develop over a period of days and grow rapidly. They often contain a central pit of keratin. They then begin to necrose and slough off. They are generally benign lesions although some do view them as precursors of malignancy. They may be treated by curettage and cautery. If there is diagnostic doubt (they can mimic malignancy) then formal excision biopsy is warranted. Pyogenic granuloma These present as friable overgrowths of granulation at sites of minor trauma. They may be ulcerated and bleeding on contact is common. They may be treated with curretage and cautery, formal excision may be used if there is diagnostic doubt.

Answer 927

A posterior urethral valve is an obstructive, developmental uropathy that usually affects male infants (incidence 1 in 8000). Diagnostic features include bladder wall hypertrophy, hydronephrosis and bladder diverticula. Urethral valves Posterior urethral valves are the commonest cause of infravesical outflow obstruction in males. They may be diagnosed on ante natal ultrasonography. Because the bladder has to develop high emptying pressures in utero, the child may develop renal parenchymal damage. This translates to renal impairment noted in 70% of boys at presentation. Treatment is with bladder catheterisation. Endoscopic valvotomy is the definitive treatment of choice with cystoscopic and renal follow up.

Answer 928

Mnemonic Muscles innervated by the musculocutaneous nerve BBC: Biceps brachii Brachialis Coracobrachialis Musculocutaneous nerve Branch of lateral cord of brachial plexus Path It penetrates the coracobrachialis muscle Passes obliquely between the biceps brachii and the brachialis to the lateral side of the arm Above the elbow it pierces the deep fascia lateral to the tendon of the biceps brachii Continues into the forearm as the lateral cutaneous nerve of the forearm Innervates Coracobrachialis Biceps brachii Brachialis

Answer 929

Hydatid disease is more common in those who work with sheep or dogs. Liver function tests may be abnormal and an eosinophilia is often present. Plain radiographs may reveal a calcified cyst wall. Fasciolopsiasis infection is confined to intestinal wall in most cases. Benign liver lesions Benign liver lesions Haemangioma Most common benign tumours of mesenchymal origin Incidence in autopsy series is 8% Cavernous haemangiomas may be enormous Clinically they are reddish purple hypervascular lesions Lesions are normally separated from normal liver by ring of fibrous tissue On ultrasound they are typically hyperechoic Liver cell adenoma 90% develop in women in their third to fifth decade Linked to use of oral contraceptive pill Lesions are usually solitary They are usually sharply demarcated from normal liver although they usually lack a fibrous capsule On ultrasound the appearances are of mixed echoity and heterogeneous texture. On CT most lesions are hypodense when imaged prior to administration of IV contrast agents In patients with haemorrhage or symptoms removal of the adenoma may be required Mesenchymal hamartomas Congential and benign, usually present in infants. May compress normal liver Liver abscess Biliary sepsis is a major predisposing factor Structures drained by the portal venous system form the second largest source Common symptoms include fever, right upper quadrant pain. Jaundice may be seen in 50% Ultrasound will usually show a fluid filled cavity, hyperechoic walls may be seen in chronic abscesses Amoebic abscess Liver abscess is the most common extra intestinal manifestation of amoebiasis Between 75 and 90% lesions occur in the right lobe Presenting complaints typically include fever and right upper quadrant pain Ultrasonography will usually show a fluid filled structure with poorly defined boundaries Aspiration yield sterile odourless fluid which has an anchovy paste consistency Treatment is with metronidazole Hyatid cysts Seen in cases of Echinococcus infection Typically an intense fibrotic reaction occurs around sites of infection The cyst has no epithelial lining Cysts are commonly unilocular and may grow to 20cm in size. The cyst wall is thick and has an external laminated hilar membrane and an internal enucleated germinal layer Typically presents with malaise and right upper quadrant pain. Secondary bacterial infection occurs in 10%. Liver function tests are usually abnormal and eosinophilia is present in 33% cases Ultrasound may show septa and hyatid sand or daughter cysts. Percutaneous aspiration was previously contra indicated, it is now incorporated into some treatment regimens Treatment is by sterilisation of the cyst with mebendazole and may be followed by surgical resection. Hypertonic swabs are packed around the cysts during surgery Polycystic liver disease Usually occurs in association with polycystic kidney disease Autosomal dominant disorder Symptoms may occur as a result of capsular stretch Cystadenoma Rare lesions with malignant potential Usually solitary multiloculated lesions Liver function tests usually normal Ultrasonography typically shows a large anechoic, fluid filled area with irregular margins. Internal echos may result from septa Surgical resection is indicated in all cases

Answer 930

T8. Levels Transpyloric plane Level of the body of L1 Pylorus stomach Left kidney hilum (L1- left one!) Fundus of the gallbladder Neck of pancreas Duodenojejunal flexure Superior mesenteric artery Portal vein Left and right colic flexure Root of the transverse mesocolon 2nd part of the duodenum Upper part of conus medullaris Spleen Can be identified by asking the supine patient to sit up without using their arms. The plane is located where the lateral border of the rectus muscle crosses the costal margin. Anatomical planes Subcostal plane Lowest margin of 10th costal cartilage Intercristal plane Level of body L4 (highest point of iliac crest) Intertubercular plane Level of body L5 Common level landmarks Inferior mesenteric artery L3 Bifurcation of aorta into common iliac arteries L4 Formation of IVC L5 (union of common iliac veins) Diaphragm apertures Vena cava T8 Oesophagus T10 Aortic hiatus T12

Answer 931

Superior quadranopia = temporal lobe lesion Inferior quadranopia = parietal lobe lesion Parietal lesions cause a contralateral inferior quadranopia. Visual field defects left homonymous hemianopia means visual field defect to the left, i.e. Lesion of right optic tract homonymous quadrantanopias: PITS (Parietal-Inferior, Temporal-Superior) incongruous defects = optic tract lesion; congruous defects = optic radiation lesion or occipital cortex Homonymous hemianopia Incongruous defects: lesion of optic tract Congruous defects: lesion of optic radiation or occipital cortex Macula sparing: lesion of occipital cortex Homonymous quadrantanopias Superior: lesion of temporal lobe Inferior: lesion of parietal lobe Mnemonic = PITS (Parietal-Inferior, Temporal-Superior) Bitemporal hemianopia Lesion of optic chiasm Upper quadrant defect > lower quadrant defect = inferior chiasmal compression, commonly a pituitary tumour Lower quadrant defect > upper quadrant defect = superior chiasmal compression, commonly a craniopharyngioma

Answer 932

The hypoglossal nerve innervates the tongue and is one of the structures more commonly at risk in carotid surgery. Internal carotid artery The internal carotid artery is formed from the common carotid opposite the upper border of the thyroid cartilage. It extends superiorly to enter the skull via the carotid canal. From the carotid canal it then passes through the cavernous sinus, above which it divides into the anterior and middle cerebral arteries. Relations in the neck Posterior Longus capitis Pre-vertebral fascia Sympathetic chain Superior laryngeal nerve Medially External carotid (near origin) Wall of pharynx Ascending pharyngeal artery Laterally Internal jugular vein (moves posteriorly at entrance to skull) Vagus nerve (most posterolaterally) Anteriorly Sternocleidomastoid Lingual and facial veins Hypoglossal nerve Relations in the carotid canal Internal carotid plexus Cochlea and middle ear cavity Trigeminal ganglion (superiorly) Leaves canal lies above the foramen lacerum Path and relations in the cranial cavity The artery bends sharply forwards in the cavernous sinus, the aducens nerve lies close to its inferolateral aspect. The oculomotor, trochlear, opthalmic and, usually, the maxillary nerves lie in the lateral wall of the sinus. Near the superior orbital fissure it turns posteriorly and passes postero-medially to pierce the roof of the cavernous sinus inferior to the optic nerve. It then passes between the optic and oculomotor nerves to terminate below the anterior perforated substance by dividing into the anterior and middle cerebral arteries. Branches Anterior and middle cerebral artery Ophthalmic artery Posterior communicating artery Anterior choroid artery Meningeal arteries Hypophyseal arteries

Answer 933

The trachea bifurcates at the level of the angle of Louis which is the intervertebral space between the fourth and fifth thoracic vertebra. Trachea Trachea Location C6 vertebra to the upper border of T5 vertebra (bifurcation) Arterial and venous supply Inferior thyroid arteries and the thyroid venous plexus. Nerve Branches of vagus, sympathetic and the recurrent nerves Relations in the neck Anterior(Superior to inferior) Isthmus of the thyroid gland Inferior thyroid veins Arteria thyroidea ima (when that vessel exists) Sternothyroid Sternohyoid Cervical fascia Anastomosing branches between the anterior jugular veins Posterior Oesophagus. Laterally Common carotid arteries Right and left lobes of the thyroid gland Inferior thyroid arteries Recurrent laryngeal nerves Relations in the thorax Anterior Manubrium, the remains of the thymus, the aortic arch, left common carotid arteries, and the deep cardiac plexus Lateral In the superior mediastinum, on the right side is the pleura and right vagus; on its left side are the left recurrent nerve, the aortic arch, and the left common carotid and subclavian arteries.

Answer 934

Rapid surgery and high dose antibiotics are indicated in the treatment of gas gangrene. Meleney's Gangrene and Necrotising Fasciitis Necrotising fasciitis Advancing soft tissue infection associated with fascial necrosis Uncommon, but can be fatal In many cases there is underlying background immunosuppression e.g. Diabetes Caused by polymicrobial flora (aerobic and anaerobic) and MRSA is seen increasingly in cases of necrotising fasciitis Streptococcus is the commonest organism in isolated pathogen infection (15%) Meleneys gangrene Meleneys is a similar principle but the infection is more superficially sited than necrotising fasciitis and often confined to the trunk Fournier gangrene Necrotising fasciitis affecting the perineum Polymicrobial with E-coli and Bacteroides acting in synergy Clinical features Fever Pain Cellulitis Oedema Induration Numbness Late findings Purple/black skin discolouration Blistering Haemorrhagic bullae Crepitus Dirty Dishwater fluid discharge Septic shock Diagnosis is mainly clinical Management Radical surgical debridement forms the cornerstone of management Sterile dressing is used to dress the wound Reconstructive surgery is considered once the infection is completely treated Reference Hasham S, Matteucci P, Stanley PR, Hart NB. Necrotising fasciitis. BMJ 2005;330:830-833.

Answer 935

Paranasal sinus cancer is strongly associated with wood work. Most cases require an occupational exposure of greater than 10 years and are adenocarcinomas on histology. Most cases are ethmoidal in origin References: Hadfield E. Ann R Coll Surg Engl. 1970 June; 46(6): 301319 Binazzi A et al. Occupational exposure and sinonasal cancer: a systematic review and meta-analysis. BMC Cancer. 2015; 15: 49. This is a comprehensive review of the topic. In particular, it summarises that it is not maxillary sinus cancer in the woodworking subgroup. Diseases of nose and sinuses Benign Tumours Simple papillomas may be an incidental finding or present with obstructive symptoms. Excision under general anaesthesia is sufficient management. Transitional cell papillomas may be more extensive and produce obstructive symptoms. Erosion of local structures is a recognised complication. These lesions may rarely undergo malignant transformation and therefore careful and complete excision is required, some cases may require partial or total maxillectomy. Pleomorphic adenomas of the maxillary sinuses are reported but are extremely rare, their symptoms typically include nasal obstruction and pain if the sinus is obstructed. Treatment is by complete surgical excision, the diagnosis is not infrequently made post operatively. Benign osteomas may develop in the paranasal sinuses, the frontal sinus is the most frequent location of such lesions. Symptoms include; pain, rhinorrhoea and anosmia. Most osteomas may be observed if asymptomatic, sphenoid osteomas should be resected soon after diagnosis as enlargement may compromise visual fields. Many sinus osteomas can now be resected endoscopically, complete surgical resection is required. Nasal polyps are benign lesions of the ethmoid sinus mucosa. Many patients may also have asthma, cystic fibrosis and a sensitivity to aspirin. Symptoms include watery rhinorrhoea, infection and anosmia. The polyps are usually a semi transparent grey mass. They are rare in childhood. Treatment is either with systemic steroids or surgical resection. The latter should be combined with antral washout. Low dose, nasal, steroid drops may reduce the risk of recurrence. Malignant disease Malignancies encountered in the nose and paranasal sinuses include; adenoid cystic carcinoma, squamous cell carcinoma and adenocarcinoma. Adenocarcinoma of the paranasal sinuses and nasopharynx is strongly linked to exposure to hard wood dust (after >10 years exposure). Adenoid cystic carcinoma usually originate in the smaller salivary glands. The majority of cancers (50%) arise from the lateral nasal wall, a smaller number (33%) arise from the maxillary antrum, ethmoid and sphenoid cancers comprise only 7%. Signs of malignancy on clinical examination include loose teeth, cranial nerve palsies and lymphadenopathy. Nasopharyngeal cancers are most common in individuals presenting from China and Asia and are linked to viral infection with Epstein Barr Virus. Radiotherapy and chemotherapy are the most commonly used modalities. Maxillary sinusitis Common symptoms include post nasal discharge, pain, headache and toothache. Imaging may show a fluid level in the antrum. Common organisms include Haemophilus influenzae or Streptococcus pneumoniae. Treatment with antral lavage may facilitate diagnosis and relieve symptoms. Antimicrobial therapy has to be continued for long periods. Antrostomy may be needed. Frontoethmoidal sinusitis Usually presents with frontal headache, nasal obstruction and altered sense of smell. Inflammation may progress to involve periorbital tissues. Ocular symptoms may occur and secondary CNS involvement brought about by infection entering via emissary veins. CT scanning is the imaging modality of choice. Early cases may be managed with antibiotics. More severe cases usually require surgical drainage.

Answer 936

Flexor digitorum is supplied by the tibial nerve. Common peroneal nerve Derived from the dorsal divisions of the sacral plexus (L4, L5, S1 and S2). This nerve supplies the skin and fascia of the anterolateral surface of the leg and the dorsum of the foot. It also innervates the muscles of the anterior and peroneal compartments of the leg, extensor digitorum brevis as well as the knee, ankle and foot joints. It is laterally placed within the sciatic nerve. From the bifurcation of the sciatic nerve it passes inferolaterally in the lateral and proximal part of the popliteal fossa, under the cover of biceps femoris and its tendon. To reach the posterior aspect of the fibular head. It ends by dividing into the deep and superficial peroneal nerves at the point where it winds around the lateral surface of the neck of the fibula in the body of peroneus longus, approximately 2cm distal to the apex of the head of the fibula. It is palpable posterior to the head of the fibula. Branches In the thigh Nerve to the short head of biceps Articular branch (knee) In the popliteal fossa Lateral cutaneous nerve of the calf Neck of fibula Superficial and deep peroneal nerves

Answer 937

Ulcerative colitis spreads in a progressive distal to proximal manner. Over time a dysplastic transformation is recognised. Such endoscopic findings mandate a minimum of close endoscopic surveillance and if they occur in association with a colonic mass then usually a panproctocolectomy. Ulcerative colitis Ulcerative colitis is a form of inflammatory bowel disease. Inflammation always starts at rectum, does not spread beyond ileocaecal valve (although backwash ileitis may occur) and is continuous. The peak incidence of ulcerative colitis is in people aged 15-25 years and in those aged 55-65 years. It is less common in smokers. The initial presentation is usually following insidious and intermittent symptoms. Features include: bloody diarrhoea urgency tenesmus abdominal pain, particularly in the left lower quadrant extra-intestinal features (see below) Questions regarding the 'extra-intestinal' features of inflammatory bowel disease are common. Extra-intestinal features include sclerosing cholangitis, iritis and ankylosing spondylitis. Common to both Crohn's disease (CD) and Ulcerative colitis (UC) Notes Related to disease activity Arthritis: pauciarticular, asymmetric Erythema nodosum Episcleritis Osteoporosis Arthritis is the most common extra-intestinal feature in both CD and UC Episcleritis is more common in Crohns disease Unrelated to disease activity Arthritis: polyarticular, symmetric Uveitis Pyoderma gangrenosum Clubbing Primary sclerosing cholangitis Primary sclerosing cholangitis is much more common in UC Uveitis is more common in UC Pathology Red, raw mucosa, bleeds easily No inflammation beyond submucosa (unless fulminant disease) Widespread superficial ulceration with preservation of adjacent mucosa which has the appearance of polyps ('pseudopolyps') Inflammatory cell infiltrate in lamina propria Neutrophils migrate through the walls of glands to form crypt abscesses Depletion of goblet cells and mucin from gland epithelium Granulomas are infrequent Barium enema Loss of haustrations Superficial ulceration, 'pseudopolyps' Long standing disease: colon is narrow and short -'drainpipe colon' Endoscopy Superficial inflammation of the colonic and rectal mucosa Continuous disease from rectum proximally Superficial ulceration, mucosal islands, loss of vascular definition and continuous ulceration pattern. Management Patients with long term disease are at increased risk of development of malignancy Acute exacerbations are generally managed with steroids, in chronic patients agents such as azathioprine and infliximab may be used Individuals with medically unresponsive disease usually require surgery- in the acute phase a sub total colectomy and end ileostomy. In the longer term a proctectomy will be required. An ileoanal pouch is an option for selected patients References Ford A et al. Ulcerative colitis. BMJ 2013 (346):29-34.

Answer 938

Septic arthritis - most common organism: Staphylococcus aureus Septic arthritis Overview Most common organism overall is Staphylococcus aureus In young adults who are sexually active Neisseria gonorrhoeae should also be considered Management Synovial fluid should be obtained before starting treatment Intravenous antibiotics which cover Gram-positive cocci are indicated. The BNF currently recommends flucloxacillin or clindamycin if penicillin allergic Antibiotic treatment is normally be given for several weeks (BNF states 6-12 weeks) Needle aspiration should be used to decompress the joint Arthroscopic lavage may be required

Answer 939

Where there are definite plans for early re-look surgery and it is desirable to visualize the viscera (as it would be in this case), application of a Bogota bag will provide the best closure option. Abdominal wound dehiscence - This is a significant problem facing all surgeons who undertake abdominal surgery on a regular basis. Traditionally, it is said to occur when all layers of an abdominal mass closure fail and the viscera protrude externally (associated with 30% mortality). It can be subdivided into superficial, in which the skin wound alone fails and complete, implying failure of all layers. Factors which increase the risk are: * Malnutrition * Vitamin deficiencies * Jaundice * Steroid use * Major wound contamination (e.g. faecal peritonitis) * Poor surgical technique (Mass closure technique is the preferred method-Jenkins Rule) When sudden full dehiscence occurs the management is as follows: * Analgesia * Intravenous fluids * Intravenous broad spectrum antibiotics * Coverage of the wound with saline impregnated gauze (on the ward) * Arrangements made for a return to theatre Surgical strategy Correct the underlying cause (e.g. TPN or NG feed if malnourished) Determine the most appropriate strategy for managing the wound Options Resuturing of the wound This may be an option if the wound edges are healthy and there is enough tissue for sufficient coverage. Deep tension sutures are traditionally used for this purpose. Application of a wound manager This is a clear dressing with removable front. Particularly suitable when some granulation tissue is present over the viscera or where there is a high output bowel fistula present in the dehisced wound. Application of a 'Bogota bag' This is a clear plastic bag that is cut and sutured to the wound edges and is only a temporary measure to be adopted when the wound cannot be closed and will necessitate a return to theatre for definitive management. Application of a VAC dressing system These can be safely used BUT ONLY if the correct layer is interposed between the suction device and the bowel. Failure to adhere to this absolute rule will almost invariably result in the development of multiple bowel fistulae and create an extremely difficult management problem.

Answer 940

In mild hypothermia TSH release is increased as is corticosterone, glucagon and aldosterone. The effects on electrolytes are minimal. There is a perceived loss of plasma volume which may reflect microvascular changes within capillary beds. Hypothermia Core body temperature below 35oC. Severe hypothermia is present when the core temperature is below 28oC. Hypothermia is associated with a reduction in both respiratory and cardiac activity. Many cases are complicated by the presence of alcohol intoxication. Stages of hypothermia Stage Features Classification Temperature oC 1 Awake and shivering Mild 32-35 2 Drowsy and not shivering Moderate 28-32 3 Unconcious and not shivering Severe 20-28 4 No vital signs Profound Less than 20 Management An organised cardiac rhythm may be converted to fibrillation if CPR is attempted inappropriately so ECG should be analysed with care. The rewarming technique used depends upon the degree of hypothermia and the physiological state of the patient. Mild hypothermia may respond to external rewarming devices. Severe hypothermia may require active core rewarming techniques such as peritoneal lavage, haemodialysis or cardiac bypass. Patients who develop cardiac arrhythmias who are severely hypothermic may respond to bretylium toslyte (sadly no longer available in most centres), but do not generally respond to standard therapies or DC cardioversion.

Answer 941

The inferior parathyroid is a derivative of the third pharyngeal pouch. The superior parathyroid originates from the fourth pharyngeal pouch. Parathyroid glands- anatomy Four parathyroid glands Located posterior to the thyroid gland They lie within the pretracheal fascia Embryology The parathyroids develop from the extremities of the third and fourth pharyngeal pouches. The parathyroids derived from the fourth pharyngeal pouch are located more superiorly and are associated with the thyroid gland. Those derived from the third pharyngeal pouch lie more inferiorly and may become associated with the thymus. Blood supply The blood supply to the parathyroid glands is derived from the inferior and superior thyroid arteries[1]. There is a rich anastomosis between the two vessels. Venous drainage is into the thyroid veins. Relations Laterally Common carotid Medially Recurrent laryngeal nerve, trachea Anterior Thyroid Posterior Pretracheal fascia References 1.Nobori, M., et al., Blood supply of the parathyroid gland from the superior thyroid artery. Surgery, 1994. 115(4): p. 417-23.

Answer 942

Retroperitoneal fibrosis is an uncommon condition and its aetiology is poorly understood. In a significant proportion the ureters are displaced medially. In most retroperitoneal malignancies they are displaced laterally. Hypertension is another common finding. A CT scan will often show a para-aortic mass Retroperitoneal fibrosis Retroperitoneal fibrosis or Ormond's disease is a disease featuring the proliferation of fibrous tissue in the retroperitoneum, the compartment of the body containing the kidneys, aorta, renal tract, and various other structures. It may present with lower back pain, kidney failure, hypertension, deep vein thrombosis, and other obstructive symptoms. It is named after John Kelso Ormond, who rediscovered the condition in 1948 Imaged with CT scanning of the abdomen Biopsy is usually performed to exclude other causes Treatment includes steroids and occasionally surgery, ureteric stent insertion is commonly required

Answer 943

Clear cell tumours are a sub type of renal cell cancer it is associated with specific genetic changes localised to chromosome 3. Renal lesions Lesion Disease specific features Treatment Renal cell carcinoma Most present with haematuria (50%) Common renal tumour (85% cases) Paraneoplastic features include hypertension and polycythaemia Most commonly has haematogenous mestastasis Usually radical or partial nephrectomy Nephroblastoma Rare childhood tumour It accounts for 80% of all genitourinary malignancies in those under the age of 15 years Up to 90% will have a mass 50% will be hypertensive Diagnostic work up includes ultrasound and CT scanning Surgical resection combined with chemotherapy (usually vincristine, actinomycin D and doxorubicin) Neuroblastoma Most common extracranial tumour of childhood 80% occur in those under 4 years of age Tumour of neural crest origin (up to 50% occur in the adrenal gland) The tumour is usually calcified and may be diagnosed using MIBG scanning Staging is with CT Surgical resection, radiotherapy and chemotherapy Transitional cell carcinoma Accounts for 90% of lower urinary tract tumours, but only 10% of renal tumours Males affected 3x more than females Occupational exposure to industrial dyes and rubber chemicals may increase risk Up to 80% present with painless haematuria Diagnosis and staging is with CT IVU Radical nephroureterectomy Angiomyolipoma 80% of these hamartoma type lesions occur sporadically, the remainder are seen in those with tuberous sclerosis Tumour is composed of blood vessels, smooth muscle and fat Massive bleeding may occur in 10% of cases 50% of patients with lesions >4cm will have symptoms and will require surgical resection

Answer 944

Contents of the jugular foramen: Anterior: inferior petrosal sinus Intermediate: glossopharyngeal, vagus, and accessory nerves Posterior: sigmoid sinus (becoming the internal jugular vein) and some meningeal branches from the occipital and ascending pharyngeal arteries The jugular foramen may be divided into three compartments: Anterior compartment transmits the inferior petrosal sinus Middle compartment transmits cranial nerves IX, X and XI Posterior compartment transmits the sigmoid sinus Foramina of the base of the skull Foramen Location Contents Foramen ovale Sphenoid bone Otic ganglion V3 (Mandibular nerve:3rd branch of trigeminal) Accessory meningeal artery Lesser petrosal nerve Emissary veins Foramen spinosum Sphenoid bone Middle meningeal artery Meningeal branch of the Mandibular nerve Foramen rotundum Sphenoid bone Maxillary nerve (V2) Foramen lacerum/ carotid canal Located between the sphenoid, the apex of the petrous temporal and the basilar part of the occipital Base of the medial pterygoid plate. Internal carotid artery* Nerve and artery of the pterygoid canal Jugular foramen Temporal bone Anterior: inferior petrosal sinus Intermediate: glossopharyngeal, vagus, and accessory nerves. Posterior: sigmoid sinus (becoming the internal jugular vein) and some meningeal branches from the occipital and ascending pharyngeal arteries. Foramen magnum Occipital bone Anterior and posterior spinal arteries Vertebral arteries Medulla oblongata Stylomastoid foramen Temporal bone Stylomastoid artery Facial nerve Superior orbital fissure Sphenoid bone Oculomotor nerve (III) Recurrent meningeal artery Trochlear nerve (IV) Lacrimal, frontal and nasociliary branches of opthalmic nerve (V1) Abducent nerve (VI) Superior ophthalmic vein *= In life the foramen lacerum is occluded by a cartilagenous plug. The ICA initially passes into the carotid canal which ascends superomedially to enter the cranial cavity through the foramen lacerum.

Answer 945

The internal mammary artery is an excellent conduit for coronary artery bypass. It has better long term patency rates than venous grafts. The thoraco-acromial artery is seldom used. Cardiopulmonary bypass Indications for surgery Left main stem stenosis or equivalent (proximal LAD and proximal circumflex) Triple vessel disease Diffuse disease unsuitable for PCI The guidelines state that CABG is the preferred treatment in high-risk patients with severe ventricular dysfunction or diabetes mellitus. Technique General anaesthesia Central and arterial lines Midline sternotomy or left sub mammary incision Aortic root and pericardium dissected Heart inspected Bypass grafting may be performed using a cardiopulmonary bypass circuit with cardiac arrest or using a number of novel 'off pump' techniques. Procedure cardiopulmonary bypass Aortic root cannulated Right atrial cannula Circuit primed and patient fully heparinised (30,000 Units unfractionated heparin) as the circuit is highly thrombogenic Flow established through circuit Aortic cross clamp applied Cardioplegia solution instilled into the aortic root below cross clamp Heart now asystolic and ready for surgery Off pump techniques are evolving on a constant basis and details are beyond the scope of the MRCS. Conduits for bypass > Internal mammary artery is best. Use of both is associated with increased risk of sternal wound dehiscence. However, many surgeons will use both especially for redo surgery. > Radial artery harvested from forearm. Ensure ulnar collateral working first! > Reversed long saphenous vein grafts Typically anastamosed using 7/0-8/0 prolene sutures (distally) and 6/0 prolene for top end. Once flow established Anticoagulation reversed using protamine Patient is taken off bypass Inotropes given if needed Sternum closed using sternal closure device or stainless steel wire Complications Post perfusion syndrome: transient cognitive impairment Non union of the sternum; due to loss of the internal thoracic artery Myocardial infarction Late graft stenosis Acute renal failure Stroke Gastrointestinal Perioperative risk is quantified using the Parsonnet and Euroscores and unit outcomes are audited using this data. Reference Eagle KA, Guyton RA, Davidoff R, et al: ACC/AHA 2004 guideline update for coronary artery bypass graft surgery: A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee to Revise the 1999 Guidelines for Coronary Artery Bypass Graft Surgery). Circulation 2004; 110

Answer 946

Anti phospholipid syndrome= following antibodies Lupus anticoagulant Anti-cardiolipin Anti-β2-glycoprotein Antiphospholipid syndrome, is an autoimmune, hypercoagulable state caused by antiphospholipid antibodies. APS provokes blood clots (thrombosis) in both arteries and veins as well as pregnancy-related complications such as miscarriage, stillbirth, preterm delivery, or severe preeclampsia. The diagnostic criteria requires one clinical event, i.e. thrombosis or pregnancy complication, and two positive blood tests spaced at least 3 months apart. These antibodies are: lupus anticoagulant, anti-cardiolipin and anti-β2-glycoprotein. Antiphospholipid syndrome can be primary or secondary. Primary antiphospholipid syndrome occurs in the absence of any other related disease. Secondary antiphospholipid syndrome occurs with other autoimmune diseases, such as systemic lupus erythematosus (SLE). In rare cases, APS leads to rapid organ failure due to generalised thrombosis; this is termed catastrophic antiphospholipid syndrome (CAPS) and is associated with a high risk of death. Antiphospholipid syndrome often requires treatment with anticoagulant medication such as heparin to reduce the risk of further episodes of thrombosis and improve the prognosis of pregnancy. Warfarin is not used during pregnancy because it can cross the placenta, unlike heparin, and is teratogenic. Hypercoagulability Type of thrombophilia Features Antithrombin deficiency Antithrombin inactivates thrombin and factor XII a, XIa, IXa and Xa Rare defect, inherited in autosomal dominant fashion 10x increase in risk of thrombotic events Heparin may be ineffective because it works via antithrombin Protein C and S deficiency These are natural anticoagulants (vitamin K dependent synthesis) Protein C produced by liver Protein S produced by liver, megakaryocytes, Leydig cells and endothelial cells Protein C and S bind to form activated complex which binds to factor V Deficiency accounts for up to 5% of thrombotic episodes Factor V Leiden Resistance to anticoagulant effect of activated protein C May account for up to 20% or more of thrombotic episodes Prevalence of 7% in Europe Most common genetic defect accounting for DVT Antiphospholipid syndrome Multi organ disease Pregnancy involvement common Arterial and venous thromboses Either Lupus anticoagulant or Anti cardiolipin antibodies APTT usually prolonged Antibodies may be elevated following surgery, drugs or malignancy Need anticoagulation with INR between 3 and 4

Answer 947

The middle colic artery supplies the transverse colon and requires high ligation during cancer resections. It is a branch of the superior mesenteric artery. Transverse colon The right colon undergoes a sharp turn at the level of the hepatic flexure to become the transverse colon. At this point it also becomes intraperitoneal. It is connected to the inferior border of the pancreas by the transverse mesocolon. The greater omentum is attached to the superior aspect of the transverse colon from which it can easily be separated. The mesentery contains the middle colic artery and vein. The greater omentum remains attached to the transverse colon up to the splenic flexure. At this point the colon undergoes another sharp turn. Relations Superior Liver and gall-bladder, the greater curvature of the stomach, and the lower end of the spleen Inferior Small intestine Anterior Greater omentum Posterior From right to left with the descending portion of the duodenum, the head of the pancreas, convolutions of the jejunum and ileum, spleen

Answer 948

The extrinsic pathway is the main path of coagulation. Heparin inhibits the activation of factors 2,9,10,11. The activation of factor 10 is when both pathways meet. Thrombin converts fibrinogen to fibrin. During fibrinolysis plasminogen is converted to plasmin to break down fibrin. Coagulation cascade Two pathways lead to fibrin formation Intrinsic pathway (components already present in the blood) Minor role in clotting Subendothelial damage e.g. collagen Formation of the primary complex on collagen by high-molecular-weight kininogen (HMWK), prekallikrein, and Factor 12 Prekallikrein is converted to kallikrein and Factor 12 becomes activated Factor 12 activates Factor 11 Factor 11 activates Factor 9, which with its co-factor Factor 8a form the tenase complex which activates Factor 10 Extrinsic pathway (needs tissue factor released by damaged tissue) Tissue damage Factor 7 binds to Tissue factor This complex activates Factor 9 Activated Factor 9 works with Factor 8 to activate Factor 10 Common pathway Activated Factor 10 causes the conversion of prothrombin to thrombin Thrombin hydrolyses fibrinogen peptide bonds to form fibrin and also activates factor 13 to form links between fibrin molecules Fibrinolysis Plasminogen is converted to plasmin to facilitate clot resorption Clotting pathway Clotting parameters affected Factors affected Intrinsic pathway Increased APTT Factors 8,9,11,12 Extrinsic pathway Increased PT Factor 7 Common pathway Increased APTT & PT Factors 2,5,10 Vitamin K dependent Factors 2,7,9,10

Answer 949

B-Even in cases where an open fracture is present, patella fractures can be managed with definitive fixation and encirlage wires represent one such technique. Patella fractures do not lend themselves to external fixator placement. Patella excision would be an unusual immediate option unless severe contamination and or severe comminution were present. Patella fractures These are rather uncommon injuries and account for around 1% of fractures overall. Around 7% of them are open injuries. Typical mechanisms include either direct impact of indirect tension style injuries which occur from rapid knee flexion against contracted quadriceps muscle causing failure in tension. Depending on mechanism some are comminuted injuries others can be simple transverse or inferior avulsion style injuries. Management is determined by mechanism of injury and patient status. Vertical or minimally displaced fractures can be managed by conservative measures. More complex fracture patterns may require operative fixation. There are several operative techniques, plates, cannulated screws and wires are all used. Healing rates of up to 95% are seen. Patients with open fractures see non union rates of up to 10%. Cases which are infected or fail to heal or are significantly infected may require partial or total patellectomy and tendon advancement. These procedures carry associated functional compromise.

Answer 950

Prosthetic heart valves on Chest X-rays The aortic and mitral valves are most commonly replaced and when a metallic valve is used, can be most readily identified on plain x-rays. The presence of cardiac disease (such as cardiomegaly) may affect the figures quoted here. Aortic Usually located medial to the 3rd interspace on the right. Mitral Usually located medial to the 4th interspace on the left. Tricuspid Usually located medial to the 5th interspace on the right. Please note that these are the sites at which an artificial valve may be located and are NOT the sites of auscultation.

Answer 951

PTH has a very short half life usually less than 10 minutes. Therefore a demonstrable drop in serum PTH should be identified within 10 minutes of removing the adenoma. This is useful clinically since it is possible to check the serum PTH intraoperatively prior to skin closure and explore the other glands if levels fail to fall. Calcium homeostasis Calcium ions are linked to a wide range of physiological processes. The largest store of bodily calcium is contained within the skeleton. Calcium levels are primarily controlled by parathyroid hormone, vitamin D and calcitonin. Hormonal regulation of calcium Hormone Actions Parathyroid hormone (PTH) Increase calcium levels and decrease phosphate levels Increases bone resorption Immediate action on osteoblasts to increase ca2+ in extracellular fluid Osteoblasts produce a protein signaling molecule that activate osteoclasts which cause bone resorption Increases renal tubular reabsorption of calcium Increases synthesis of 1,25(OH)2D (active form of vitamin D) in the kidney which increases bowel absorption of Ca2+ Decreases renal phosphate reabsorption 1,25-dihydroxycholecalciferol (the active form of vitamin D) Increases plasma calcium and plasma phosphate Increases renal tubular reabsorption and gut absorption of calcium Increases osteoclastic activity at high levels and osteoblasts at low levels Increases renal phosphate reabsorption Calcitonin Secreted by C cells of thyroid Inhibits intestinal calcium absorption Inhibits osteoclast activity Inhibits renal tubular absorption of calcium Both growth hormone and thyroxine also play a small role in calcium metabolism.

Answer 952

Osteopetrosis is an autosomal recessive condition. It is commonest in young adults. They may present with symptoms of anaemia or thrombocytopaenia due to decreased marrow space. Radiology reveals a lack of differentiation between the cortex and the medulla described as marble bone. These bones are very dense and brittle. Paediatric fractures Paediatric fracture types Type Injury pattern Complete fracture Both sides of cortex are breached Toddlers fracture Oblique tibial fracture in infants Plastic deformity Stress on bone resulting in deformity without cortical disruption Greenstick fracture Unilateral cortical breach only Buckle fracture Incomplete cortical disruption resulting in periosteal haematoma only Growth plate fractures In paediatric practice fractures may also involve the growth plate and these injuries are classified according to the Salter- Harris system (given below): Type Injury pattern I Fracture through the physis only (x-ray often normal) II Fracture through the physis and metaphysis III Fracture through the physis and epiphyisis to include the joint IV Fracture involving the physis, metaphysis and epiphysis V Crush injury involving the physis (x-ray may resemble type I, and appear normal) As a general rule it is safer to assume that growth plate tenderness is indicative of an underlying fracture even if the x-ray appears normal. Injuries of Types III, IV and V will usually require surgery. Type V injuries are often associated with disruption to growth. Non accidental injury Delayed presentation Delay in attaining milestones Lack of concordance between proposed and actual mechanism of injury Multiple injuries Injuries at sites not commonly exposed to trauma Children on the at risk register Pathological fractures Genetic conditions, such as osteogenesis imperfecta, may cause pathological fractures. Osteogenesis imperfecta Defective osteoid formation due to congenital inability to produce adequate intercellular substances like osteoid, collagen and dentine. Failure of maturation of collagen in all the connective tissues. Radiology may show translucent bones, multiple fractures, particularly of the long bones, wormian bones (irregular patches of ossification) and a trefoil pelvis. Subtypes Type I The collagen is normal quality but insufficient quantity. Type II- Poor collagen quantity and quality. Type III- Collagen poorly formed. Normal quantity. Type IV- Sufficient collagen quantity but poor quality. Osteopetrosis Bones become harder and more dense. Autosomal recessive condition. It is commonest in young adults. Radiology reveals a lack of differentiation between the cortex and the medulla described as marble bone.

Answer 953

In most cases the submandibular space is involved. Incision and drainage of this space is often undertaken. Ludwigs angina This is a severe form of infection which affects the floor of mouth and surrounding tissues. The underlying cause in many cases is dental caries affecting the third molar tooth. The floor of the mouth and neck usually becomes very swollen and drooling is often seen. The presence of immunosuppression or conditions like diabetes or HIV increases the risks. Staphylococcal organisms and streptococcal organisms account for many cases. Management comprises careful attention to maintaining airway, prompt administration of antibiotics and surgical drainage of any discrete collections. The underlying cause should also be identified and addressed.

Answer 954

The sural nerve is closely related and damage to this structure is a major cause of litigation. The other structures may all be injured but the risks are lower. Popliteal fossa Boundaries of the popliteal fossa Laterally Biceps femoris above, lateral head of gastrocnemius and plantaris below Medially Semimembranosus and semitendinosus above, medial head of gastrocnemius below Floor Popliteal surface of the femur, posterior ligament of knee joint and popliteus muscle Roof Superficial and deep fascia Contents Popliteal artery and vein Small saphenous vein Common peroneal nerve Tibial nerve Posterior cutaneous nerve of the thigh Genicular branch of the obturator nerve Lymph nodes

Answer 955

Trotter's triad (diagnosis of nasopharyngeal carcinoma) Unilateral conductive hearing loss Ipsilateral facial & ear pain Ipsilateral paralysis of soft palate The clinical scenario is most typical for nasopharyngeal carcinoma. An association with previous Epstein Barr Virus is well established. Infection with the other viruses listed is not a recognised risk factor for the development of the condition. Nasopharyngeal carcinoma Squamous cell carcinoma of the nasopharynx Rare in most parts of the world, apart from individuals from Southern China Associated with Epstein Barr virus infection Presenting features Systemic Local Cervical lymphadenopathy Otalgia Unilateral serous otitis media Nasal obstruction, discharge and/ or epistaxis Cranial nerve palsies e.g. III-VI Imaging Combined CT and MRI. Treatment Radiotherapy is first line therapy.

Answer 956

The IMA leaves the front of the aorta usually about 3 to 4cm superior to its bifurcation. The median sacral is not an anterior branch. Abdominal aortic branches Branches Level Paired Type Inferior phrenic T12 (Upper border) Yes Parietal Coeliac T12 No Visceral Superior mesenteric L1 No Visceral Middle suprarenal L1 Yes Visceral Renal L1-L2 Yes Visceral Gonadal L2 Yes Visceral Lumbar L1-L4 Yes Parietal Inferior mesenteric L3 No Visceral Median sacral L4 No Parietal Common iliac L4 Yes Terminal

Answer 957

The routine use of mechanical bowel preparation is not recommended. There is some recent evidence to support the use of selective gut decontamination. However, this is not in mainstream practice at present. Surgical site infection - Surgical site infections may occur following a breach in tissue surfaces and allow normal commensals and other pathogens to initiate infection. They are a major cause of morbidity and mortality. Surgical site infections (SSI) comprise up to 20% of all healthcare associated infections and at least 5% of patients undergoing surgery will develop an SSI as a result. In many cases the organisms are derived from the patient's own body. Measures that may increase the risk of SSI include: Shaving the wound using a razor (disposable clipper preferred) Using a non iodine impregnated incise drape if one is deemed to be necessary Tissue hypoxia Delayed administration of prophylactic antibiotics in tourniquet surgery Preoperatively Don't remove body hair routinely If hair needs removal, use electrical clippers with single use head (razors increase infection risk) Antibiotic prophylaxis if: - placement of prosthesis or valve - clean-contaminated surgery - contaminated surgery Use local formulary Aim to give single dose IV antibiotic on anaesthesia If a tourniquet is to be used, give prophylactic antibiotics earlier Intraoperatively Prepare the skin with alcoholic chlorhexidine (Lowest incidence of SSI) Cover surgical site with dressing A recent meta analysis has confirmed that administration of supplementary oxygen does not reduce the risk of wound infection. In contrast to previous individual RCT's(1) Wound edge protectors do not appear to confer benefit (2) Post operatively Tissue viability advice for management of surgical wounds healing by secondary intention Use of diathermy for skin incisions In the NICE guidelines the use of diathermy for skin incisions is not advocated(3). Several randomised controlled trials have been undertaken and demonstrated no increase in risk of SSI when diathermy is used(4). References 1. Brar M et al.. Perioperative supplemental oxygen in colorectal patients: a meta analysis. J Surg Res 2011 (166): 227 -235. 2. Pinkney T et al. Impact of wound edge protection devices on surgical site infection after laparotomy: impact of a multicentre randomised controlled trial (ROSSINI Trial). BMJ 2013 (347):10. 3. http://www.nice.org.uk/CG74 4. Ahmad N and Ahmed A. Meta-analysis of the effectiveness of surgical scalpel or diathermy in making abdominal skin incisions. Ann Surg 2011, 253(1):8-13.

Answer 958

The patient has coeliac disease and this is classically associated with dermatitis herpetiformis. Skin Diseases Skin lesions may be referred for surgical assessment, but more commonly will come via a dermatologist for definitive surgical management. Skin malignancies include basal cell carcinoma, squamous cell carcinoma and malignant melanoma. Basal Cell Carcinoma Most common form of skin cancer. Commonly occur on sun exposed sites apart from the ear. Sub types include nodular, morphoeic, superficial and pigmented. Typically slow growing with low metastatic potential. Standard surgical excision, topical chemotherapy and radiotherapy are all successful. As a minimum a diagnostic punch biopsy should be taken if treatment other than standard surgical excision is planned. Squamous Cell Carcinoma Again related to sun exposure. May arise in pre - existing solar keratoses. May metastasize if left. Immunosupression (e.g. following transplant), increases risk. Wide local excision is the treatment of choice and where a diagnostic excision biopsy has demonstrated SCC, repeat surgery to gain adequate margins may be required. Malignant Melanoma The main diagnostic features (major criteria): Change in size Change in shape Change in colour Secondary features (minor criteria) Diameter >6mm Inflammation Oozing or bleeding Altered sensation Treatment Suspicious lesions should undergo excision biopsy. The lesion should be removed completely as incision biopsy can make subsequent histopathological assessment difficult. Once the diagnosis is confirmed the pathology report should be reviewed to determine whether further re-excision of margins is required (see below): Margins of excision-Related to Breslow thickness Lesions 0-1mm thick 1cm Lesions 1-2mm thick 1- 2cm (Depending upon site and pathological features) Lesions 2-4mm thick 2-3 cm (Depending upon site and pathological features) Lesions >4 mm thick 3cm Marsden J et al. Revised UK guidelines for management of Melanoma. Br J Dermatol 2010 163:238-256. Further treatments such as sentinel lymph node mapping, isolated limb perfusion and block dissection of regional lymph node groups should be selectively applied. Kaposi Sarcoma Tumour of vascular and lymphatic endothelium. Purple cutaneous nodules. Associated with immuno supression. Classical form affects elderly males and is slow growing. Immunosupression form is much more aggressive and tends to affect those with HIV related disease. Non malignant skin disease Dermatitis Herpetiformis Chronic itchy clusters of blisters. Linked to underlying gluten enteropathy (coeliac disease). Dermatofibroma Benign lesion. Firm elevated nodules. Usually history of trauma. Lesion consists of histiocytes, blood vessels and fibrotic changes. Pyogenic granuloma Overgrowth of blood vessels. Red nodules. Usually follow trauma. May mimic amelanotic melanoma. Acanthosis nigricans Brown to black, poorly defined, velvety hyperpigmentation of the skin. Usually found in body folds such as the posterior and lateral folds of the neck, the axilla, groin, umbilicus, forehead, and other areas. The most common cause of acanthosis nigricans is insulin resistance, which leads to increased circulating insulin levels. Insulin spillover into the skin results in its abnormal increase in growth (hyperplasia of the skin). In the context of a malignant disease, acanthosis nigricans is a paraneoplastic syndrome and is then commonly referred to as acanthosis nigricans maligna. Involvement of mucous membranes is rare and suggests a coexisting malignant condition.

Answer 959

In children with ongoing losses, these should be replaced with 0.9% sodium chloride with added potassium. Paediatric fluid management Since 2000 there have been at least 4 reported deaths from fluid induced hyponatraemia in children. This led to the National Patient Safety Agency introducing revised guidelines in 2007. These have been reviewed and extensively updated by NICE in 2015 and further modified in 2020. Indications for IV fluids include: Resuscitation and circulatory support Replacing on-going fluid losses Maintenance fluids for children for whom oral fluids are not appropriate Correction of electrolyte disturbances Fluids to be avoided Outside the neonatal period saline / glucose solutions should not be given. The greatest risk is with saline 0.18 / glucose 4% solutions. The report states that 0.45% saline / 5% glucose may be used. But preference should be given to isotonic solutions and few indications exist for this solution either. The key point emphasised in the NICE guidelines in the avoidance of glucose containing solutions and instead of routinely giving glucose IV to children and neonates, the blood glucose levels should be monitored. In neonates in the first few days of life, sodium levels in the range of 131-154 mmol/l may be too high and a neonatologist consulted on a case by case basis. Fluids to be used If children and young people need IV fluids for routine maintenance, initially use isotonic crystalloids that contain sodium in the range 131 to 154 mmol/litre Potassium should be added to maintenance fluids according patients plasma potassium levels (which should be monitored). Blood glucose levels should be monitored in individuals at risk of hypoglycaemia Intraoperative fluid management If children and young people need IV fluids for routine maintenance, initially use isotonic crystalloids that contain sodium in the range 131 to 154 mmol/litre Blood glucose levels should be monitored Maintenance fluids Weight Water requirement/kg/day Na mmol/kg/day K mmol/kg/day First 10Kg body weight 100ml 2-4 1.5-2.5 Second 10Kg body weight 50ml 1-2 0.5-1.5 Subsequent Kg 20ml 0.5-1.0 0.2-0.7 Blood glucose will need to be monitored Reference NPSA -reducing risk of hyponatraemia when administering intravenous fluids to children. Issue date March 2007. Further references included in this document. NICE Guidance NG29. Intravenous fluid therapy in children and young people in hospital. Published 2015, reviewed an updated 2020.

Answer 960

The psoas major inserts into the lesser trochanter. Psoas Muscle Origin The deep part originates from the transverse processes of the five lumbar vertebrae, the superficial part originates from T12 and the first 4 lumbar vertebrae. Insertion Lesser trochanter of the femur. Innervation Anterior rami of L1 to L3. Action Flexion and external rotation of the hip. Bilateral contraction can raise the trunk from the supine position.

Answer 961

Squamous cell carcinomas are reported to be more slow growing and are typically centrally located. Small cell carcinomas are usually centrally located. However, small cell carcinomas would seldom be associated with a survival of a year without treatment. Lung cancer Lung cancers may be classified according to histological subtypes. The main distinction is between small cell and non small cell lung cancer. Non small cell lung cancer is the most common variant and accounts for 80% of all lung cancers. Non small cell lung cancer These share common features of prognosis and management. They comprise the following tumours: Squamous cell carcinoma (25% cases) Adenocarcinoma (40% cases) Large cell carcinoma (10% cases) Paraneoplastic features and early disease dissemination are less likely than with small cell lung carcinoma. Adenocarcinoma is the most common lung cancer type encountered in never smokers. Small cell lung carcinoma Small cell lung carcinomas are comprised of cells with a neuro endocrine differentiation. The neuroendocrine hormones may be released from these cells with a wide range of paraneoplastic associations. These tumours are strongly associated with smoking and will typically arise in the larger airways. They disseminate early in the course of the disease and although they are usually chemosensitive this seldom results in long lasting remissions.

Answer 962

CTPA is the first line investigation for PE according to current BTS guidelines Current UK NICE guidance supports CTPA as first line investigation now. Pulmonary angiography is of course the 'gold standard' but this is not what the question asks for Pulmonary embolism: investigation UK 2020 NICE guidance endorses CTPA is most cases of suspected PE. Key points from the guidelines include: computed tomographic pulmonary angiography (CTPA) is now the recommended initial lung-imaging modality for non-massive PE. Advantages compared to V/Q scans include speed, easier to perform out-of-hours, a reduced need for further imaging and the possibility of providing an alternative diagnosis if PE is excluded if the CTPA is negative then patients do not need further investigations or treatment for PE ventilation-perfusion scanning may be used initially if appropriate facilities exist, the chest x-ray is normal, and there is no significant symptomatic concurrent cardiopulmonary disease Some other points Clinical probability scores based on risk factors and history and now widely used to help decide on further investigation/management D-dimers sensitivity = 95-98%, but poor specificity V/Q scan sensitivity = 98%; specificity = 40% - high negative predictive value, i.e. if normal virtually excludes PE other causes of mismatch in V/Q include old pulmonary embolisms, AV malformations, vasculitis, previous radiotherapy COPD gives matched defects CTPA peripheral emboli affecting subsegmental arteries may be missed Pulmonary angiography the gold standard significant complication rate compared to other investigations

Answer 963

Metastatic bone pain may respond to NSAIDs, bisphosphonates or radiotherapy Bone pain often responds well to NSAIDs. Both radiotherapy and bisphosphonates have a role in managing bony pain but these are not first-line treatments. Palliative care prescribing: pain SIGN issued guidance on the control of pain in adults with cancer in 2008. Selected points the breakthrough dose of morphine is one-sixth the daily dose of morphine all patients who receive opioids should be prescribed a laxative opioids should be used with caution in patients with chronic kidney disease. Alfentanil, buprenorphine and fentanyl are preferred metastatic bone pain may respond to NSAIDs, bisphosphonates or radiotherapy When increasing the dose of opioids the next dose should be increased by 30-50%. Conversion between opioids From To Oral codeine Oral morphine Divide by 10 Oral tramadol Oral morphine Divide by 5 From To Oral morphine Oral oxycodone Divide by 2 The BNF states that oral morphine sulphate 80-90mg over 24 hours is approximately equivalent to one '25 mcg/hour' fentanyl patch, therefore product literature should be consulted. From To Oral morphine Subcutaneous diamorphine Divide by 3 Oral oxycodone Subcutaneous diamorphine Divide by 1.5

Answer 964

Ileo-ileal intussusception are far less common than the ileo-colic variant. However, where they occur, they require surgery and are not amenable to pneumatic reduction. Intussusception- Paediatric Intussusception typically presents with colicky abdominal pain and vomiting. The telescoping of the bowel produces mucosal ischaemia and bleeding may occur resulting in the passage of red current jelly stools. Recognised causes include lumenal pathologies such as polyps, lymphadenopathy and diseases such as cystic fibrosis. Idiopathic intussceception of the ileocaecal valve and terminal ileum is the most common variant and typically affects young children and toddlers. The diagnosis is usually made by abdominal ultrasound investigation. The decision as to the optimal treatment is dictated by the patients physiological status and abdominal signs. In general, children who are unstable with localising peritoneal signs should undergo laparotomy, as should those in whom attempted radiological reduction has failed. In relatively well children, without localising signs, attempted pneumatic reduction under fluroscopic guidance is the usual treatment. This is not done where there are concerns about impending perforation or if there is a small bowel intussusception.

Answer 965

The mnemonic 'SALTR' can be used to help remember the first five types. This mnemonic requires the reader to imagine the bones as long bones, with the epiphyses at the base. I 'S' = Slip (separated or straight across). Fracture of the cartilage of the physis (growth plate) II 'A' = Above. The fracture lies above the physis, or Away from the joint. III 'L' = Lower. The fracture is below the physis in the epiphysis. IV 'TE' = Through Everything. The fracture is through the metaphysis, physis, and epiphysis. V 'R' = Rammed (crushed). The physis has been crushed The Salter - Harris system is most commonly used. The radiological signs in Type 1 and 5 injuries may be identical. Which is unfortunate as type 5 injuries do not do well (and may be missed!). One of our users has helpfully supplied a mnemonic for remembering the types (see above).

Answer 966

The superior mesenteric artery arises from the aorta and passes anterior to the lower part of the pancreas. Invasion of this structure is a relative contra indication to resectional surgery. Pancreas The pancreas is a retroperitoneal organ and lies posterior to the stomach. It may be accessed surgically by dividing the peritoneal reflection that connects the greater omentum to the transverse colon. The pancreatic head sits in the curvature of the duodenum. Its tail lies close to the hilum of the spleen, a site of potential injury during splenectomy. Relations Posterior to the pancreas Pancreatic head Inferior vena cava Common bile duct Right and left renal veins Superior mesenteric vein and artery Pancreatic neck Superior mesenteric vein, portal vein Pancreatic body- Left renal vein Crus of diaphragm Psoas muscle Adrenal gland Kidney Aorta Pancreatic tail Left kidney Anterior to the pancreas Pancreatic head 1st part of the duodenum Pylorus SMA and SMV(uncinate process) Pancreatic body Stomach Duodenojejunal flexure Pancreatic tail Splenic hilum Superior to the pancreas Coeliac trunk and its branches common hepatic artery and splenic artery Grooves of the head of the pancreas 2nd and 3rd part of the duodenum Arterial supply Head: pancreaticoduodenal artery Rest: splenic artery Venous drainage Head: superior mesenteric vein Body and tail: splenic vein Ampulla of Vater Merge of pancreatic duct and common bile duct Is an important landmark, halfway along the second part of the duodenum, that marks the anatomical transition from foregut to midgut (also the site of transition between regions supplied by coeliac trunk and SMA).

Answer 967

Mnemonic for the causes of hypercalcaemia: CHIMPANZEES C alcium supplementation H yperparathyroidism I atrogentic (Drugs: Thiazides) M ilk Alkali syndrome P aget disease of the bone A cromegaly and Addison's Disease N eoplasia Z olinger-Ellison Syndrome (MEN Type I) E xcessive Vitamin D E xcessive Vitamin A S arcoidosis Patients with coeliac disease tend to develop hypocalcaemia due to malabsorption of calcium by the bowel.

Answer 968

The history of polyhydramios makes diaphragmatic hernia less likely. The other conditions tend not to cause choking. In the short term this is addressed by passage of a Replogle tube which can be used to remove the oesophageal secretions, pending surgery. Paediatric Gastrointestinal disorders Pyloric stenosis M>F 5-10% Family history in parents Projectile non bile stained vomiting at 4-6 weeks of life Diagnosis is made by test feed or USS Treatment: Ramstedt pyloromyotomy (open or laparoscopic) Acute appendicitis Uncommon under 3 years When occurs may present atypically Mesenteric adenitis Central abdominal pain and URTI Conservative management Intussusception Telescoping bowel Proximal to or at the level of, ileocaecal valve 6-9 months age Colicky pain, diarrhoea and vomiting, sausage shaped mass, red jelly stool. Treatment: reduction with air insufflation Malrotation High caecum at the midline Feature in exomphalos, congenital diaphragmatic hernia, intrinsic duodenal atresia May be complicated by development of volvulus, infant with volvulus may have bile stained vomiting Diagnosis is made by upper GI contrast study and USS Treatment is by laparotomy, if volvulus is present (or at high risk of occurring then a ladds procedure is performed Hirschsprung's disease Absence of ganglion cells from myenteric and submucosal plexuses Occurs in 1/5000 births Full thickness rectal biopsy for diagnosis Delayed passage of meconium and abdominal distension Treatment is with rectal washouts initially, thereafter an anorectal pull through procedure Oesophageal atresia Associated with tracheo-oesophageal fistula and polyhydramnios May present with choking and cyanotic spells following aspiration VACTERL associations Meconium ileus Usually delayed passage of meconium and abdominal distension Majority have cystic fibrosis X-Rays may not show a fluid level as the meconium is viscid (depends upon feeding), PR contrast studies may dislodge meconium plugs and be therapeutic Infants who do not respond to PR contrast and NG N-acetyl cysteine will require surgery to remove the plugs Biliary atresia Jaundice > 14 days Increased conjugated bilirubin Urgent Kasai procedure Necrotising enterocolitis Prematurity is the main risk factor Early features include abdominal distension and passage of bloody stools X-Rays may show pneumatosis intestinalis and evidence of free air Increased risk when empirical antibiotics are given to infants beyond 5 days Treatment is with total gut rest and TPN, babies with perforations will require laparotomy

Answer 969

The brachialis inserts some of its fibres into the fibrous joint of the elbow capsule and when it contracts, it helps to flex the joint. Elbow joint This large synovial joint is of the hinge variety of joint, the bones of the forearm articulate with the lower end of the humerus. The upper ends of the radius and ulnar are bound together by the anular ligament of the radius in such a way as to permit movement between these two bones at what is described as the proximal radio-ulnar joint. The elbow and the proximal radio-ulnar joints have a common fibrous capsule and synovial cavity, and though the anular ligament plays a part in the structure of both joints, it is described with the proximal radio-ulnar joint. Articular surfaces The humeral articular surface at the elbow comprises the grooved trochlea, the spheroidal capitulum, and the sulcus between them. This composite surface is covered by a layer of articular cartilage. The capitulum is confined to the anterior and distal aspects of the bone, but the trochea extends round the distal end of the bone from the lower edge of the coronoid fossa on the front of the humerus to the lower edge of the olecranon fossa posteriorly. The articular surface covering the ulnar surface of the elbow joint is interrupted along the deepest part in a transverse line. Then trochlear notch articulates with the trochlea of the humerus forming a saddle shaped joint with it. The radial surface has a slight concavity to the proximal surface of the head which articulates with the capitulum while its raised margin lies on the capitulotrochlear groove. This surface of the head is covered with articular cartilage which is continuous with that round the sides in the radio-ulnar joint. The radial and ulnar surfaces are most fully in contact with the corresponding humeral surfaces when the forearm is in a position midway between full pronation and supination and the elbow is fixed to a right angle. Fibrous capsule The joint is encased within a fibrous capsule that is relatively weak anteriorly and posteriorly, its strengthened at the sides to form the radial and ulnar collateral ligaments. The anterior part of the capsule is attached to the front of the humerus immediately superior to the radial and coronoid fossae, to the anterior border of the coronoid process of the ulna, and to the anterior part of the anular ligament of the radius. The brachialis muscle covers the greater part of the front of the capsule, and some of its deep fibres insert into the capsule. The posterior part of the capsule is very weak in its median part. However, the tendon of triceps inserts at this site and supports it and also draws it upwards in extension. The radial collateral ligament is a strong triangular shaped thickening of the fibrous capsule. Its apex is attached superiorly to the antero-inferior aspect of the lateral epicondyle of the humerus in close relation to the common extensor muscles whose common origin overlies this site. Distally, the broad base of the ligament blends with the anular ligament of the radius, and is attached both in front and behind to the margins of the radial notch on the ulna. The ulna collateral ligament is comprised of three capsular condensations which are continuous with one another. An anterior band passes from the front of the medial epicondyle of the humerus to the medial edge of the coronoid process of the ulna; it is closely related to the common origin of the superficial flexor muscles. A posterior band is attached above to the back of the medial epicondyle and below to the medial edge of the olecranon. A transverse band stretches between the attachments of the anterior and posterior bands on the coronoid process and the olecranon. The lower edge of this transverse ligament is free, a small amount of synovial membrane may protrude through the space between this and the underlying bone. Synovial membrane The attachments of the synovial membrane generally follow those of the fibrous capsule. Nerve supply The elbow joint derives its nerve supply from the musculocutaneous, median, radial and ulnar nerves. Movements Movement occurs around a transverse axis, a movement of flexion when the forearm makes anteriorly a diminishing angle with the upper arm and extension when the opposite occurs. The axis of movement passes through the humeral epicondyles and is not at right angles with either the humerus or bones of the forearm. In full extension with the forearm supinated, the arm and forearm form an angle which is more than 180 degrees, the extent to which this angle is exceeded is termed the carrying angle. The carrying angle is masked when the forearm is pronated.

Answer 970

Contraindications to lung cancer surgery include SVC obstruction, FEV < 1.5, MALIGNANT pleural effusion, and vocal cord paralysis Paralysis of a vocal cord implies extracapsular spread to mediastinal nodes and is an indication of inoperability. Lung cancer: non-small cell management Management Only 20% suitable for surgery Mediastinoscopy performed prior to surgery as CT does not always show mediastinal lymph node involvement Curative or palliative radiotherapy Poor response to chemotherapy Surgery contraindications Assess general health Stage IIIb or IV (i.e. metastases present) FEV1 < 1.5 litres is considered a general cut-off point* Malignant pleural effusion Tumour near hilum Vocal cord paralysis SVC obstruction * However if FEV1 < 1.5 for lobectomy or < 2.0 for pneumonectomy then some authorities advocate further lung function tests as operations may still go ahead based on the results

Answer 971

This patient has acute adrenal insufficiency and urgently needs steroid replacement. Addisonian crisis Causes Sepsis or surgery causing an acute exacerbation of chronic insufficiency (Addison's, Hypopituitarism) Adrenal haemorrhage eg Waterhouse-Friderichsen syndrome (fulminant meningococcemia) Steroid withdrawal Management Hydrocortisone 100 mg im or iv 1 litre normal saline infused over 30-60 mins or with dextrose if hypoglycaemic Continue hydrocortisone 6 hourly until the patient is stable. No fludrocortisone is required because high cortisol exerts weak mineralocorticoid action Oral replacement may begin after 24 hours and be reduced to maintenance over 3-4 days

Answer 972

Neostigmine affects the degradation of acetylcholine and will therefore stimulate both nicotinic and muscarinic receptors. It may produce symptomatic bradycardia and should therefore only be administered in a monitored environment. In colonic pseudo-obstruction it produces generalised colonic contractions and its onset is usually rapid. Colonic pseudo-obstruction Colonic pseudo-obstruction is characterised by the progressive and painless dilation of the colon. The abdomen may become grossly distended and tympanic. Unless a complication such as impending bowel necrosis or perforation occurs, there is usually little pain. Diagnosis involves excluding a mechanical bowel obstruction with a plain film and contrast enema. The underlying cause is usually electrolyte imbalance and the condition will resolve with correction of this and supportive care. Patients who do not respond to supportive measures should be treated with attempted colonoscopic decompression and/ or the drug neostigmine. In rare cases surgery may be required.

Answer 973

The sural nerve supplies the lateral aspect of the foot. It runs alongside the short saphenous vein and may be injured in short saphenous vein surgery. Foot- Cutaneous sensation Region Nerve Lateral plantar Sural Dorsum (not 1st web space) Superficial peroneal 1st Web space Deep peroneal Extremities of toes Medial and lateral plantar nerves Proximal plantar Tibial Medial plantar Medial plantar nerve Lateral plantar (inferior aspect) Lateral plantar nerve

Answer 974

Femoro-femoral cross over grafts are an option for treatment of iliac occlusions in patients with significant co-morbidities and healthy contralateral vessels. In reality, the idealised situation presented here seldom applies and the opposite vessels usually have some disease and one must be careful not to damage the healthy side. Peripheral vascular disease Indications for surgery to revascularise the lower limb Intermittent claudication Critical ischaemia Ulceration Gangrene Intermittent claudication that is not disabling may provide a relative indication, whilst the other complaints are often absolute indications depending upon the frailty of the patient. Assessment Clinical examination Ankle brachial pressure index measurement Duplex arterial ultrasound Angiography (standard, CT or MRI): usually performed only if intervention being considered. Angioplasty In order for angioplasty to be undertaken successfully the artery has to be accessible. The lesion relatively short and reasonable distal vessel runoff. Longer lesions may be amenable to sub-intimal angioplasty. Surgery Surgery will be undertaken where attempts at angioplasty have either failed or are unsuitable. Bypass essentially involves bypassing the affected arterial segment by utilising a graft to run from above the disease to below the disease. As with angioplasty good runoff improves the outcome. Some key concepts with bypass surgery Superficial femoral artery occlusion to the above knee popliteal In the ideal scenario, vein (either in situ or reversed LSV) would be used as a conduit. However, prosthetic material has reasonable 5 year patency rates and some would advocate using this in preference to vein so that vein can be used for other procedures in the future. In general terms either technique is usually associated with an excellent outcome (if run off satisfactory). Procedure Artery dissected out, IV heparin 3,000 units given and then the vessels are cross clamped Longitudinal arteriotomy Graft cut to size and tunneled to arteriotomy sites Anastomosis to femoral artery usually with 5/0 'double ended' Prolene suture Distal anastomosis usually using 6/0 'double ended' Prolene Distal disease Femoro-distal bypass surgery takes longer to perform, is more technically challenging and has higher failure rates. In elderly diabetic patients with poor runoff a primary amputation may well be a safer and more effective option. There is no point in embarking on this type of surgery in patients who are wheelchair bound. In femorodistal bypasses vein gives superior outcomes to PTFE. Rules Vein mapping 1st to see whether there is suitable vein (the preferred conduit). Sub intimal hyperplasia occurs early when PTFE is used for the distal anastomosis and will lead to early graft occlusion and failure. Essential operative procedure as for above knee fem-pop. If there is insufficient vein for the entire conduit then vein can be attached to the end of the PTFE graft and then used for the distal anastomosis. This type of 'vein boot' is technically referred to as a Miller Cuff and is associated with better patency rates than PTFE alone. Remember the more distal the arterial anastomosis the lower the success rate. References Peach G et al. Diagnosis and management of peripheral arterial disease. BMJ 2012; 345: 36-41.

Answer 975

B Chest drains There are a number of different indications for chest drain insertion. In general terms large bore chest drains are preferred for trauma and haemothorax drainage. Smaller diameter chest drains can be used for pneumothorax or pleural effusion drainage. Insertion can be performed either using anatomical guidance or through ultrasound guidance. In the exam, the anatomical method is usually tested. It is advised that chest drains are placed in the 'safe triangle'. The triangle is located in the mid axillary line of the 5th intercostal space. It is bordered by: Anterior edge latissimus dorsi, the lateral border of pectoralis major, a line superior to the horizontal level of the nipple, and the apex below the axilla. Another triangle is situated behind the scapula. It is bounded above by the trapezius, below by the latissimus dorsi, and laterally by the vertebral border of the scapula; the floor is partly formed by the rhomboid major. If the scapula is drawn forward by folding the arms across the chest, and the trunk bent forward, parts of the sixth and seventh ribs and the interspace between them become subcutaneous and available for auscultation. The space is therefore known as the triangle of auscultation. References Prof Harold Ellis. The applied anatomy of chest drains insertions. British Journal of hospital medicine 2007; (68): 44-45. Laws D, Neville E, Duffy J. BTS guidelines for insertion of chest drains. Thorax, 2003; (58): 53-59.

Answer 976

Mnemonic: OVALE O tic ganglion V3 (Mandibular nerve:3rd branch of trigeminal) A ccessory meningeal artery L esser petrosal nerve E missary veins Foramina of the base of the skull Foramen Location Contents Foramen ovale Sphenoid bone Otic ganglion V3 (Mandibular nerve:3rd branch of trigeminal) Accessory meningeal artery Lesser petrosal nerve Emissary veins Foramen spinosum Sphenoid bone Middle meningeal artery Meningeal branch of the Mandibular nerve Foramen rotundum Sphenoid bone Maxillary nerve (V2) Foramen lacerum/ carotid canal Located between the sphenoid, the apex of the petrous temporal and the basilar part of the occipital Base of the medial pterygoid plate. Internal carotid artery* Nerve and artery of the pterygoid canal Jugular foramen Temporal bone Anterior: inferior petrosal sinus Intermediate: glossopharyngeal, vagus, and accessory nerves. Posterior: sigmoid sinus (becoming the internal jugular vein) and some meningeal branches from the occipital and ascending pharyngeal arteries. Foramen magnum Occipital bone Anterior and posterior spinal arteries Vertebral arteries Medulla oblongata Stylomastoid foramen Temporal bone Stylomastoid artery Facial nerve Superior orbital fissure Sphenoid bone Oculomotor nerve (III) Recurrent meningeal artery Trochlear nerve (IV) Lacrimal, frontal and nasociliary branches of opthalmic nerve (V1) Abducent nerve (VI) Superior ophthalmic vein *= In life the foramen lacerum is occluded by a cartilagenous plug. The ICA initially passes into the carotid canal which ascends superomedially to enter the cranial cavity through the foramen lacerum.

Answer 977

The superior mesenteric vein drains into the portal vein. The right and left hepatic veins drain into it directly, this can account for major bleeding in more extensive liver shearing type injuries. Inferior vena cava Origin L5 Path Left and right common iliac veins merge to form the IVC. Passes right of midline Paired segmental lumbar veins drain into the IVC throughout its length The right gonadal vein empties directly into the cava and the left gonadal vein generally empties into the left renal vein. The next major veins are the renal veins and the hepatic veins Pierces the central tendon of diaphragm at T8 Right atrium Relations Anteriorly Small bowel, first and third part of duodenum, head of pancreas, liver and bile duct, right common iliac artery, right gonadal artery Posteriorly Right renal artery, right psoas, right sympathetic chain, coeliac ganglion Levels Level Vein T8 Hepatic vein, inferior phrenic vein, pierces diaphragm L1 Right suprarenal vein, renal vein L2 Gonadal vein L1-5 Lumbar veins L5 Common iliac vein, formation of IVC

Answer 978

Etomidate is a recognised cause of adrenal suppression, this has been associated with increased mortality when used as a sedation agent in the critically ill. Anaesthetic agents The table below summarises some of the more commonly used IV induction agents Agent Specific features Propofol Rapid onset of anaesthesia Pain on IV injection Rapidly metabolised with little accumulation of metabolites Proven anti emetic properties Moderate myocardial depression Widely used especially for maintaining sedation on ITU, total IV anaesthesia and for daycase surgery Sodium thiopentone Extremely rapid onset of action making it the agent of choice for rapid sequence of induction Marked myocardial depression may occur Metabolites build up quickly Unsuitable for maintenance infusion Little analgesic effects Ketamine May be used for induction of anaesthesia Has moderate to strong analgesic properties Produces little myocardial depression making it a suitable agent for anaesthesia in those who are haemodynamically unstable May induce state of dissociative anaesthesia resulting in nightmares Etomidate Has favorable cardiac safety profile with very little haemodynamic instability No analgesic properties Unsuitable for maintaining sedation as prolonged (and even brief) use may result in adrenal suppression Post operative vomiting is common

Answer 979

The vagus nerve is the most posteriorly located structure at the lung root. The phrenic nerve lies most anteriorly. Lung anatomy The right lung is composed of 3 lobes divided by the oblique and transverse fissures. The left lung has two lobes divided by the oblique fissure.The apex of both lungs is approximately 4cm superior to the sterno-costal joint of the first rib. Immediately below this is a sulcus created by the subclavian artery. Peripheral contact points of the lung Base: diaphragm Costal surface: corresponds to the cavity of the chest Mediastinal surface: Contacts the mediastinal pleura. Has the cardiac impression. Above and behind this concavity is a triangular depression named the hilum, where the structures which form the root of the lung enter and leave the viscus. These structures are invested by pleura, which, below the hilum and behind the pericardial impression, forms the pulmonary ligament Right lung Above the hilum is the azygos vein; Superior to this is the groove for the superior vena cava and right innominate vein; behind this, and nearer the apex, is a furrow for the innominate artery. Behind the hilum and the attachment of the pulmonary ligament is a vertical groove for the oesophagus; In front and to the right of the lower part of the oesophageal groove is a deep concavity for the extrapericardiac portion of the inferior vena cava. The root of the right lung lies behind the superior vena cava and the right atrium, and below the azygos vein. The right main bronchus is shorter, wider and more vertical than the left main bronchus and therefore the route taken by most foreign bodies. Left lung Above the hilum is the furrow produced by the aortic arch, and then superiorly the groove accommodating the left subclavian artery; Behind the hilum and pulmonary ligament is a vertical groove produced by the descending aorta, and in front of this, near the base of the lung, is the lower part of the oesophagus. The root of the left lung passes under the aortic arch and in front of the descending aorta. Inferior borders of both lungs 6th rib in mid clavicular line 8th rib in mid axillary line 10th rib posteriorly The pleura runs two ribs lower than the corresponding lung level. Bronchopulmonary segments Segment number Right lung Left lung 1 Apical Apical 2 Posterior Posterior 3 Anterior Anterior 4 Lateral Superior lingular 5 Medial Inferior lingular 6 Superior (apical) Superior (apical) 7 Medial basal Medial basal 8 Anterior basal Anterior basal 9 Lateral basal Lateral basal 10 Posterior basal Posterior basal

Answer 980

By 16 years of age almost all foreskins should be retractile and if they are not circumcision should be considered at around this time. Paediatric urology- foreskin disorders Disorders of the foreskin At birth and in the neonatal period the normal foreskin is non retractile due to the presence of adhesions between the foreskin and glans. In most cases these will separate spontaneously. By the end of puberty 95% of foreskins can be retracted. In some children the non-retractile foreskin may balloon during micturition. This is a normal variant and requires no specific treatment. Balanitis This is inflammation of the glans penis. It may occur in both circumcised and non-circumcised individuals. Posthitis This is inflammation of the foreskin. It may occur as a result of infections such as gonorrhoea and other STD's. It may also complicate diabetes. Posthitis may progress to phimosis and as this may make cleaning of the glans difficult and allow progression to balanoposthitis. Paraphimosis Prolonged retraction of the foreskin proximal to the glans may allow oedema to occur. This may then make foreskin manipulation difficult. It can usually be managed by compression to reduce the oedema and replacement of the foreskin. Where this fails a dorsal slit may be required and this followed by delayed circumcision. Phimosis This is inability to retract the foreskin and may be partial or complete. It may occur secondary to balanoposthitis or balanitis xerotica obliterans. Depending upon the severity and symptoms treatment with circumcision may be required. Balanitis xerotica obliterans This is a dermatological condition in which scarring of the foreskin occurs leading to phimosis. It is rare below the age of 5 years. Treatment is usually with circumcision.

Answer 981

Calcium is mainly absorbed from the small bowel and this will have a direct long term impact on calcium metabolism and increase the risk of osteoporosis. Gastric banding and distal gastrectomy may affect a patients dietary choices but any potential deleterious nutritional intake may be counteracted by administration of calcium supplements orally. Only 10% of calcium is absorbed from the colon so that a sub total colectomy will only have a negligible effect. Calcium homeostasis Calcium ions are linked to a wide range of physiological processes. The largest store of bodily calcium is contained within the skeleton. Calcium levels are primarily controlled by parathyroid hormone, vitamin D and calcitonin. Hormonal regulation of calcium Hormone Actions Parathyroid hormone (PTH) Increase calcium levels and decrease phosphate levels Increases bone resorption Immediate action on osteoblasts to increase ca2+ in extracellular fluid Osteoblasts produce a protein signaling molecule that activate osteoclasts which cause bone resorption Increases renal tubular reabsorption of calcium Increases synthesis of 1,25(OH)2D (active form of vitamin D) in the kidney which increases bowel absorption of Ca2+ Decreases renal phosphate reabsorption 1,25-dihydroxycholecalciferol (the active form of vitamin D) Increases plasma calcium and plasma phosphate Increases renal tubular reabsorption and gut absorption of calcium Increases osteoclastic activity at high levels and osteoblasts at low levels Increases renal phosphate reabsorption Calcitonin Secreted by C cells of thyroid Inhibits intestinal calcium absorption Inhibits osteoclast activity Inhibits renal tubular absorption of calcium Both growth hormone and thyroxine also play a small role in calcium metabolism.

Answer 982

Duodenal polyps occur in up to 100% of patients with FAP if follow up is continued for long enough. Duodenal cancer has an incidence of 4-10%. Duodenal polyps are the commonest extra colonic lesion in FAP. Gastric fundal polyps are seen in 50% of patients. Skull osteomas are seen in Gardeners syndrome which is a variant of FAP. Polyposis syndromes Syndrome Genetic defect Features Screening and management Associated disorders Familial adenomatous polyposis Mutation of APC gene (80%) cases, dominant Typically over 100 colonic adenomas Cancer risk of 100% 20% are new mutations If known to be at risk then predictive genetic testing as teenager Annual flexible sigmoidoscopy from 15 years If no polyps found then 5 yearly colonoscopy started at age 20 Polyps found = resectional surgery (resection and pouch Vs sub total colectomy and IRA) Gastric fundal polyps (50%). Duodenal polyps 90%. If severe duodenal polyposis cancer risk of 30% at 10 years. Abdominal desmoid tumours. MYH associated polyposis Biallelic mutation of mut Y human homologue (MYH) on chromosome 1p, recessive Multiple colonic polyps Later onset right sided cancers more common than in FAP 100% cancer risk by age 60 Once identified resection and ileoanal pouch reconstruction is recommended Attenuated phenotype - regular colonoscopy Duodenal polyposis in 30% Associated with increased risk of breast cancer (self examination) Peutz -Jeghers syndrome STK11 (LKB1) mutation on chromosome 19 in some (but not all) cases, dominant Multiple benign intestinal hamartomas Episodic obstruction and intussceception Increased risk of GI cancers (colorectal cancer 20%, gastric 5%) Increased risk of breast, ovarian, cervical pancreatic and testicular cancers Annual examination Pan intestinal endoscopy every 2-3 years Malignancies at other sites Classical pigmentation pattern Cowden disease Mutation of PTEN gene on chromosome 10q22, dominant Macrocephaly Multiple intestinal hamartomas Multiple trichilemmomas 89% risk of cancer at any site 16% risk of colorectal cancer Targeted individualised screening Breast cancer (81% risk) Thyroid cancer and non toxic goitre Uterine cancer HNPCC (Lynch syndrome) Germline mutations of DNA mismatch repair genes Colo rectal cancer 30-70% Endometrial cancer 30-70% Gastric cancer 5-10% Scanty colonic polyps may be present Colonic tumours likely to be right sided and mucinous Colonoscopy every 1-2 years from age 25 Consideration of prophylactic surgery Extra colonic surveillance recommended Extra colonic cancers

Answer 983

The radial nerve may become entrapped in the arcade of Frohse which is a superficial part of the supinator muscle which overlies the posterior interosseous nerve. This nerve is entirely muscular and articular in its distribution. It passes postero-inferiorly and gives branches to extensor carpi radialis brevis and supinator. It enters supinator and curves around the lateral and posterior surfaces of the radius. On emerging from the supinator the posterior interosseous nerve lies between the superficial extensor muscles and the lowermost fibres of supinator. It then gives branches to the extensors. Posterior interosseous nerve Emerges from supinator between the superficial extensor muscles and lowest fibres of supinator It gives recurrent branches which innervate extensor digitorum, extensor digiti minimi and extensor carpi ulnaris It then passes with the posterior interosseous artery superficial to the abductor pollicis longus supplying it. It supplies branches to extensor pollicis longus and brevis and extensor indicis and ends as a small gangliform enlargement at the back of the carpus from which the intercarpal joints are supplied.

Answer 984

Although this is likely to be benign disease, her age coupled with an episode of blood stained discharge would attract a recommendation for microdochectomy. She may have an intraductal papilloma. But the concern would be DCIS. Nipple discharge Causes of nipple discharge Physiological During breast feeding Galactorrhoea Commonest cause may be response to emotional events, drugs such as histamine receptor antagonists are also implicated Hyperprolactinaemia Commonest type of pituitary tumour Microadenomas <1cm in diameter Macroadenomas >1cm in diameter Pressure on optic chiasm may cause bitemporal hemianopia Mammary duct ectasia Dilatation breast ducts. Most common in menopausal women Discharge typically thick and green in colour Most common in smokers Carcinoma Often blood stained May be underlying mass or axillary lymphadenopathy Intraductal papilloma Commoner in younger patients May cause blood stained discharge There is usually no palpable lump Assessment of patients Examine breast and determine whether there is mass lesion present All mass lesions should undergo Triple assessment. Reporting of investigations Where a mass lesion is suspected or investigations are requested these are prefixed using a system that denotes the investigation type e.g. M for mammography, followed by a numerical code as shown below: 1 No abnormality 2 Abnormality with benign features 3 Indeterminate probably benign 4 Indeterminate probably malignant 5 Malignant Management of non malignant nipple discharge Exclude endocrine disease Nipple cytology unhelpful Smoking cessation advice for duct ectasia For duct ectasia with severe symptoms, total duct excision may be warranted.

Answer 985

Venous drainage of hemorrhoidal tissue mirrors embryologic origin. Internal hemorrhoids drain through the superior rectal vein into the portal system. External hemorrhoids drain through the inferior rectal vein into the inferior vena cava. Rectum The rectum is approximately 12 cm long. It is a capacitance organ. It has both intra and extraperitoneal components. The transition between the sigmoid colon is marked by the disappearance of the tenia coli.The extra peritoneal rectum is surrounded by mesorectal fat that also contains lymph nodes. This mesorectal fatty layer is removed surgically during rectal cancer surgery (Total Mesorectal Excision). The fascial layers that surround the rectum are important clinical landmarks, anteriorly lies the fascia of Denonvilliers. Posteriorly lies Waldeyers fascia. Extra peritoneal rectum Posterior upper third Posterior and lateral middle third Whole lower third Relations Anteriorly (Males) Rectovesical pouch Bladder Prostate Seminal vesicles Anteriorly (Females) Recto-uterine pouch (Douglas) Cervix Vaginal wall Posteriorly Sacrum Coccyx Middle sacral artery Laterally Levator ani Coccygeus Arterial supply Superior rectal artery Middle rectal artery (from the internal iliac) Inferior rectal artery (from the pudendal vessels) Venous drainage Superior rectal vein Inferior rectal vein Note the venous drainage is a site of portosystemic anastomosis. Lymphatic drainage Mesorectal lymph nodes (superior to dentate line) Inguinal nodes (inferior to dentate line)

Answer 986

A persistent vitello-intestinal duct may allow the persistent and ongoing discharge of small bowel content from the umbilicus. This fluid may be very irritant to the surrounding skin. Paediatric umbilical disorders Embryology During development the umbilicus has two umbilical arteries and one umbilical vein. The arteries are continuous with the internal iliac arteries and the vein is continuous with the falciform ligament (ductus venosus). After birth the cord dessicates and separates and the umbilical ring closes. Umbilical hernia Up to 20% of neonates may have an umbilical hernia, it is more common in premature infants. The majority of these hernias will close spontaneously (may take between 12 months and three years). Strangulation is rare. Paraumbilical hernia These are due to defects in the linea alba that are in close proximity to the umbilicus. The edges of a paraumbilical hernia are more clearly defined than those of an umbilical hernia. They are less likely to resolve spontaneously than an umbilical hernia. Omphalitis This condition consists of infection of the umbilicus. Infection with Staphylococcus aureus is the commonest cause. The condition is potentially serious as infection may spread rapidly through the umbilical vessels in neonates with a risk of portal pyaemia, and portal vein thrombosis. Treatment is usually with a combination of topical and systemic antibiotics. Umbilical granuloma These consist of cherry red lesions surrounding the umbilicus, they may bleed on contact and be a site of seropurulent discharge. Infection is unusual and they will often respond favorably to chemical cautery with topically applied silver nitrate. Persistent urachus This is characterised by urinary discharge from the umbilicus. It is caused by persistence of the urachus which attaches to the bladder. They are associated with other urogenital abnormalities. Persistent vitello-intestinal duct This will typically present as an umbilical discharge that discharges small bowel content. Complete persistence of the duct is a rare condition. Much more common is the persistence of part of the duct (Meckels diverticulum). Persistent vitello-intestinal ducts are best imaged using a contrast study to delineate the anatomy and are managed by laparotomy and surgical closure.

Answer 987

Gastrinomas are typically the source of gastrin in Zollinger Ellison syndrome. Upper gastrointestinal bleeding Patients may present with the following: Haematemesis and/ or malaena Epigastric discomfort Sudden collapse The extent to which these will occur will depend upon the source. Mortality is higher in patients presenting with haematemesis than malaena alone. Oesophageal bleeding Cause Presenting features Oesophagitis Small volume of fresh blood, often streaking vomit. Malaena rare. Often ceases spontaneously. Usually history of antecedent GORD type symptoms. Cancer Usually small volume of blood, except as pre terminal event with erosion of major vessels. Often associated symptoms of dysphagia and constitutional symptoms such as weight loss. May be recurrent until malignancy managed. Mallory Weiss Tear Typically brisk small to moderate volume of bright red blood following bout of repeated vomiting. Malaena rare. Usually ceases spontaneously. Varices Usually large volume of fresh blood. Swallowed blood may cause malaena. Often associated with haemodynamic compromise. May stop spontaneously but re-bleeds are common until appropriately managed. Gastric Bleeding Cause Presenting features Gastric cancer May be frank haematemesis or altered blood mixed with vomit. Usually prodromal features of dyspepsia and may have constitutional symptoms. Amount of bleeding variable but erosion of major vessel may produce considerable haemorrhage. Dieulafoy Lesion Often no prodromal features prior to haematemesis and malaena, but this arteriovenous malformation may produce quite considerable haemorrhage and may be difficult to detect endoscopically. Diffuse erosive gastritis Usually haematemesis and epigastric discomfort. Usually there is an underlying cause such as recent NSAID usage. Large volume haemorrhage may occur with considerable haemodynamic compromise. Gastric ulcer Small low volume bleeds more common so would tend to present as iron deficiency anaemia. Erosion into a significant vessel may produce considerable haemorrhage and haematemesis. Duodenum Most common cause of major haemorrhage is a posteriorly sited duodenal ulcer. However, ulcers at any site in the duodenum may present with haematemesis, malaena and epigastric discomfort. The pain of duodenal ulcer is slightly different to that of gastric ulcers and often occurs several hours after eating. Peri ampullary tumours may bleed but these are rare. In patients with previous abdominal aortic aneurysm surgery aorto-enteric fistulation remains a rare but important cause of major haemorrhage associated with high mortality. Management Admission to hospital careful monitoring, cross match blood, check FBC, LFTs, U+E and Clotting (as a minimum) Patients with on-going bleeding and haemodynamic instability are likely to require O negative blood pending cross matched blood Early control of airway is vital (e.g. Drowsy patient with liver failure) Patients with suspected varices should receive terlipressin prior to endoscopy Ideally all patients admitted with upper gastrointestinal haemorrhage should undergo Upper GI endoscopy within 24 hours of admission. In those who are unstable this should occur immediately after resuscitation or in tandem with it. The endoscopy department is a potentially dangerous place for unstable patients and it may be safer to perform the endoscopy in theatre with an anaesthetist present. Varices should be banded or subjected to sclerotherapy. If this is not possible owing to active bleeding then a Sengstaken- Blakemore tube (or Minnesota tube) should be inserted. This should be done with care; gastric balloon should be inflated first and oesophageal balloon second. Remember the balloon will need deflating after 12 hours (ideally sooner) to prevent necrosis. Portal pressure should be lowered by combination of medical therapy +/- TIPSS. Patients with erosive oesophagitis / gastritis should receive a proton pump inhibitor. Mallory Weiss tears will typically resolve spontaneously Identifiable bleeding points should receive combination therapy of injection of adrenaline and either a thermal or mechanical treatment. All who have received intervention should receive a continuous infusion of a proton pump inhibitor (IV omeprazole for 72 hours) to reduce the re-bleeding rate. Patients with diffuse erosive gastritis who cannot be managed endoscopically and continue to bleed may require gastrectomy Bleeding ulcers that cannot be controlled endoscopically may require laparotomy and ulcer underruning Indications for surgery Patients > 60 years Continued bleeding despite endoscopic intervention Recurrent bleeding Known cardiovascular disease with poor response to hypotension Surgery Duodenal ulcer Laparotomy, duodenotomy and under running of the ulcer. If bleeding is brisk then the ulcer is almost always posteriorly sited and will have invaded the gastroduodenal artery. Large bites using 0 Vicryl are taken above and below the ulcer base to occlude the vessel. The duodenotomy should be longitudinal but closed transversely to avoid stenosis. For gastric ulcer Under-running of the bleeding site Partial gastrectomy-antral ulcer Partial gastrectomy or under running the ulcer- lesser curve ulcer (involving left gastric artery) Total gastrectomy if bleeding persists Summary of Acute Upper GI bleeding recommendations: The need for admission and timing of endoscopic intervention may be predicted by using the Blatchford score. This considers a patients Hb, serum urea, pulse rate and blood pressure. Those patients with a score of 0 are low risk, all others are considered high risk and require admission and endoscopy. The requirement for pre endoscopic proton pump inhibition is contentious. In the UK the National Institute of Clinical Excellence guidelines suggest the pre endoscopic PPI therapy is unnecessary. Whilst it is accepted that such treatment has no impact on mortality or morbidity a Cochrane review of this practice in 2007 did suggest that it reduced the stigmata of recent haemorrhage at endoscopy. As a result many will still administer PPI to patients prior to endoscopic intervention. Following endoscopy it is important to calculate the Rockall score for patients to determine their risk of rebleeding and mortality. A score of 3 or less is associated with a rebleeding rate of 4% and a very low risk of mortality and identifies a group of patients suitable for early discharge. References 1. http://www.sign.ac.uk/guidelines/fulltext/105/index.html 2. Joint Advisory Group on Endoscopy (JAG) Guidelines - http://www.thejag.org.uk 3. NICE Guideline: Management of acute upper GI bleeding. July 2012.

Answer 988

B- These may still extend by virtue of retained lumbrical muscle function. Radial nerve Continuation of posterior cord of the brachial plexus (root values C5 to T1) Path In the axilla: lies posterior to the axillary artery on subscapularis, latissimus dorsi and teres major. Enters the arm between the brachial artery and the long head of triceps (medial to humerus). Spirals around the posterior surface of the humerus in the groove for the radial nerve. At the distal third of the lateral border of the humerus it then pierces the intermuscular septum and descends in front of the lateral epicondyle. At the lateral epicondyle it lies deeply between brachialis and brachioradialis where it then divides into a superficial and deep terminal branch. Deep branch crosses the supinator to become the posterior interosseous nerve. egions innervated Motor (main nerve) Triceps Anconeus Brachioradialis Extensor carpi radialis Motor (posterior interosseous branch) Supinator Extensor carpi ulnaris Extensor digitorum Extensor indicis Extensor digiti minimi Extensor pollicis longus and brevis Abductor pollicis longus Sensory The area of skin supplying the proximal phalanges on the dorsal aspect of the hand is supplied by the radial nerve (this does not apply to the little finger and part of the ring finger) Muscular innervation and effect of denervation Anatomical location Muscle affected Effect of paralysis Shoulder Long head of triceps Minor effects on shoulder stability in abduction Arm Triceps Loss of elbow extension Forearm Supinator Brachioradialis Extensor carpi radialis longus and brevis Weakening of supination of prone hand and elbow flexion in mid prone position

Answer 989

They lie in the carotid sinus and aortic arch. Cardiac physiology - The heart has four chambers ejecting blood into both low pressure and high pressure systems. The pumps generate pressures of between 0-25mmHg on the right side and 0-120 mmHg on the left. At rest diastole comprises 2/3 of the cardiac cycle. The product of the frequency of heart rate and stroke volume combine to give the cardiac output which is typically 5-6L per minute. Detailed descriptions of the various waveforms are often not a feature of MRCS A (although they are on the syllabus). However, they are a very popular topic for surgical physiology in the MRCS B exam. Electrical properties Intrinsic myogenic rhythm within cardiac myocytes means that even the denervated heart is capable of contraction. In the normal situation the cardiac impulse is generated in the sino atrial node in the right atrium and conveyed to the ventricles via the atrioventricular node. The sino atrial node is also capable of spontaneous discharge and in the absence of background vagal tone will typically discharge around 100x per minute. Hence the higher resting heart rate found in cardiac transplant cases. In the SA and AV nodes the resting membrane potential is lower than in surrounding cardiac cells and will slowly depolarise from -70mV to around -50mV at which point an action potential is generated. Differences in the depolarisation slopes between SA and AV nodes help to explain why the SA node will depolarise first. The cells have a refractory period during which they cannot be re-stimulated and this period allows for adequate ventricular filling. In pathological tachycardic states this time period is overridden and inadequate ventricular filling may then occur, cardiac output falls and syncope may ensue. Parasympathetic fibres project to the heart via the vagus and will release acetylcholine. Sympathetic fibres release nor adrenaline and circulating adrenaline comes from the adrenal medulla. Noradrenaline binds to β 1 receptors in the SA node and increases the rate of pacemaker potential depolarisation. Cardiac cycle Image sourced from Wikipedia Mid diastole: AV valves open. Ventricles hold 80% of final volume. Outflow valves shut. Aortic pressure is high. Late diastole: Atria contract. Ventricles receive 20% to complete filling. Typical end diastolic volume 130-160ml. Early systole: AV valves shut. Ventricular pressure rises. Isovolumetric ventricular contraction. AV Valves bulge into atria (c-wave). Aortic and pulmonary pressure exceeded- blood is ejected. Shortening of ventricles pulls atria downwards and drops intra atrial pressure (x-descent). Late systole: Ventricular muscles relax and ventricular pressures drop. Although ventricular pressure drops the aortic pressure remains constant owing to peripheral vascular resistance and elastic property of the aorta. Brief period of retrograde flow that occurs in aortic recoil shuts the aortic valve. Ventricles will contain 60ml end systolic volume. The average stroke volume is 70ml (i.e. Volume ejected). Early diastole: All valves are closed. Isovolumetric ventricular relaxation occurs. Pressure wave associated with closure of the aortic valve increases aortic pressure. The pressure dip before this rise can be seen on arterial waveforms and is called the incisura. During systole the atrial pressure increases such that it is now above zero (v- wave). Eventually atrial pressure exceed ventricular pressure and AV valves open - atria empty passively into ventricles and atrial pressure falls (y -descent ) The negative atrial pressures are of clinical importance as they can allow air embolization to occur if the neck veins are exposed to air. This patient positioning is important in head and neck surgery to avoid this occurrence if veins are inadvertently cut, or during CVP line insertion. Mechanical properties Preload = end diastolic volume Afterload = aortic pressure It is important to understand the principles of Laplace's law in surgery. It states that for hollow organs with a circular cross section, the total circumferential wall tension depends upon the circumference of the wall, multiplied by the thickness of the wall and on the wall tension. The total luminal pressure depends upon the cross sectional area of the lumen and the transmural pressure. Transmural pressure is the internal pressure minus external pressure and at equilibrium the total pressure must counterbalance each other. In terms of cardiac physiology the law explains that the rise in ventricular pressure that occurs during the ejection phase is due to physical change in heart size. It also explains why a dilated diseased heart will have impaired systolic function. Starlings law Increase in end diastolic volume will produce larger stroke volume. This occurs up to a point beyond which cardiac fibres are excessively stretched and stroke volume will fall once more. It is important for the regulation of cardiac output in cardiac transplant patients who need to increase their cardiac output. Baroreceptor reflexes Baroreceptors located in aortic arch and carotid sinus. Aortic baroreceptor impulses travel via the vagus and from the carotid via the glossopharyngeal nerve. They are stimulated by arterial stretch. Even at normal blood pressures they are tonically active. Increase in baroreceptor discharge causes: *Increased parasympathetic discharge to the SA node. *Decreased sympathetic discharge to ventricular muscle causing decreased contractility and fall in stroke volume. *Decreased sympathetic discharge to venous system causing increased compliance. *Decreased peripheral arterial vascular resistance Atrial stretch receptors Located in atria at junction between pulmonary veins and vena cava. Stimulated by atrial stretch and are thus low pressure sensors. Increased blood volume will cause increased parasympathetic activity. Very rapid infusion of blood will result in increase in heart rate mediated via atrial receptors: the Bainbridge reflex. Decreases in receptor stimulation results in increased sympathetic activity this will decrease renal blood flow-decreases GFR-decreases urinary sodium excretion-renin secretion by juxtaglomerular apparatus-Increase in angiotensin II. Increased atrial stretch will also result in increased release of atrial natriuretic peptide.

Answer 990

Rhabdomyosarcoma are paratesticular tumours with a bimodal distribution. Because the mass is felt separate to the testis, this is the more likely diagnosis. 5% of testicular tumors Most often arises in distal portion of spermatic cord and may invade testis of surrounding tissues 60% occur in the first 2 decades of life Bimodal age distribution - 3-4 months - 16 years Arises from mesenchymal tissue - 90% embryonal variant (better prognosis) - 30% - 50% have metastasis (usually lymph node) at diagnosis Testicular disorders Testicular cancer Testicular cancer is the most common malignancy in men aged 20-30 years. Around 95% of cases of testicular cancer are germ-cell tumours. Germ cell tumours may essentially be divided into: Tumour type Key features Tumour markers Pathology Seminoma Commonest subtype (50%) Average age at diagnosis = 40 Even advanced disease associated with 5 year survival of 73% AFP usually normal HCG elevated in 10% seminomas Lactate dehydrogenase; elevated in 10-20% seminomas (but also in many other conditions) Sheet like lobular patterns of cells with substantial fibrous component. Fibrous septa contain lymphocytic inclusions and granulomas may be seen. Non seminomatous germ cell tumours (42%) Teratoma Yolk sac tumour Choriocarcinoma Mixed germ cell tumours (10%) Younger age at presentation =20-30 years Advanced disease carries worse prognosis (48% at 5 years) Retroperitoneal lymph node dissection may be needed for residual disease after chemotherapy AFP elevated in up to 70% of cases HCG elevated in up to 40% of cases Other markers rarely helpful Heterogenous texture with occasional ectopic tissue such as hair Risk factors for testicular cancer Cryptorchidism Infertility Family history Klinefelter's syndrome Mumps orchitis Features A painless lump is the most common presenting symptom Pain may also be present in a minority of men Other possible features include hydrocele, gynaecomastia Diagnosis Ultrasound is first-line CT scanning of the chest/ abdomen and pelvis is used for staging Tumour markers (see above) should be measured Management Orchidectomy (Inguinal approach) Chemotherapy and radiotherapy may be given depending on staging Abdominal lesions >1cm following chemotherapy may require retroperitoneal lymph node dissection. Prognosis is generally excellent 5 year survival for seminomas is around 95% if Stage I 5 year survival for teratomas is around 85% if Stage I Benign disease Epididymo-orchitis Acute epididymitis is an acute inflammation of the epididymis, often involving the testis and usually caused by bacterial infection. Infection spreads from the urethra or bladder. In men <35 years, gonorrhoea or chlamydia are the usual infections. Amiodarone is a recognised non infective cause of epididymitis, which resolves on stopping the drug. Tenderness is usually confined to the epididymis, which may facilitate differentiating it from torsion where pain usually affects the entire testis. Testicular torsion Twist of the spermatic cord resulting in testicular ischaemia and necrosis. Most common in males aged between 10 and 30 (peak incidence 13-15 years) Pain is usually severe and of sudden onset. Cremasteric reflex is lost and elevation of the testis does not ease the pain. Treatment is with surgical exploration. If a torted testis is identified then both testis should be fixed as the condition of bell clapper testis is often bilateral. Hydrocele Presents as a mass that transilluminates, usually possible to 'get above' it on examination. In younger men it should be investigated with USS to exclude tumour. In children it may occur as a result of a patent processus vaginalis. Treatment in adults is with a Lords or Jabouley procedure. Treatment in children is with trans inguinal ligation of PPV.

Answer 991

Routine chemotherapy is not effective in patients with renal adenocarcinoma and should not be used following R0 resections. Routine renal biopsy should not be performed in cases for nephrectomy. Most cases of malignancy can be accurately classified on imaging. Renal tumours Renal cell carcinoma Renal cell carcinoma is an adenocarcinoma of the renal cortex and is believed to arise from the proximal convoluted tubule. They are usually solid lesions, up to 20% may be multifocal, 20% may be calcified and 20% may have either a cystic component or be wholly cystic. They are often circumscribed by a pseudocapsule of compressed normal renal tissue. Spread may occur either by direct extension into the adrenal gland, renal vein or surrounding fascia. More distant disease usually occurs via the haematogenous route to lung, bone or brain. Renal cell carcinoma comprise up to 85% of all renal malignancies. Males are more commonly affected than females and sporadic tumours typically affect patients in their sixth decade. Patients may present with a variety of symptoms including; haematuria (50%), loin pain (40%), mass (30%) and up to 25% may have symptoms of metastasis.Less than 10% have the classic triad of haematuria, pain and mass. Investigation Many cases will present as haematuria and be discovered during diagnostic work up. Benign renal tumours are rare, so renal masses should be investigated with multislice CT scanning. Most tumours are also characterised with an arterial phase CT, particularly if they may be suitable for partial nephrectomy. CT scanning of the chest and abdomen to detect distant disease should also be undertaken. Routine bone scanning is not indicated in the absence of symptoms. Biopsy should not be performed when a nephrectomy is planned but is mandatory before any ablative therapies are undertaken. Assessment of the functioning of the contra lateral kidney. Management T1 lesions may be managed by partial nephrectomy and this gives equivalent oncological results to total radical nephrectomy. Partial nephrectomy may also be performed when there is inadequate reserve in the remaining kidney. Ablative techniques may also be considered for small T1 lesions in unfit patients. In general, outcomes are less favorable than with surgical resection. For T2 lesions and above a radical nephrectomy is standard practice and this may be performed via a laparoscopic or open approach. Preoperative embolisation is not indicated nor is resection of uninvolved adrenal glands. During surgery early venous control is mandatory to avoid shedding of tumour cells into the circulation. Patients with completely resected disease do not benefit from adjuvant therapy with either chemotherapy or biological agents. These should not be administered outside the setting of clinical trials. Patients with transitional cell cancer will require a nephroureterectomy with disconnection of the ureter at the bladder. References Capitanio U, Montorsi F. Renal cancer. Lancet. 2016 Feb 27;387(10021):894-906. Capitanio U et al. Epidemiology of Renal Cell Carcinoma. Eur Urol. 2019 Jan;75(1):74-84.

Answer 992

Takayasu's arteritis most commonly affects young Asian females. Pulseless peripheries are a classical finding. The CNS symptoms may be variable. Vascular disease Aortic dissection Chest pain (anterior chest pain- ascending aorta, back pain - descending aorta) Widening of aorta on chest x-ray Diagnosis made by CT scanning Treatment is either medical (Type B disease) or surgical (Type A disease) Cervical rib Supernumery fibrous band arising from seventh cervical vertebra Incidence of 1 in 500 May cause thoracic outlet syndrome Treatment involves surgical division of rib Subclavian steal syndrome Due to proximal stenotic lesion of the subclavian artery Results in retrograte flow through vertebral or internal thoracic arteries The result is that decrease in cerebral blood flow may occur and produce syncopal symptoms A duplex scan and/ or angiogram will delineate the lesion and allow treatment to be planned Takayasu's arteritis Large vessel granulomatous vasculitis Results in intimal narrowing Most commonly affects young asian females Patients present with features of mild systemic illness, followed by pulseless phase with symptoms of vascular insufficiency Treatment is with systemic steroids Patent ductus arteriosus Ductus arteriosus is a normal foetal vessel that closes spontaneously after birth Results in high pressure, oxygenated blood entering the pulmonary circuit Untreated patients develop symptoms of congestive cardiac failure Coarctation of the aorta Aortic stenosis at the site of the ductus arteriosus insertion More prevalent in boys or females with Turners syndrome Patients may present with symptoms of arterial insufficiency, such as syncope and claudication Blood pressure mismatch may be seen, as may mismatch of pulse pressure in the upper and lower limbs Treatment is either with angioplasty or surgical resection (the former is the most common)

Answer 993

The subclavian artery passes anterior to the middle scalene. Scalene muscles The 3 paired muscles are: Scalenus anterior: Elevate 1st rib and laterally flex the neck to same side Scalenus medius: Same action as scalenus anterior Scalenus posterior: Elevate 2nd rib and tilt the cervical spine Innervation Spinal nerves C4-6 Origin Transverse processes C2 to C7 Insertion First and second ribs Important relations The brachial plexus and subclavian artery pass between the anterior and middle scalenes through a space called the scalene hiatus/fissure. The subclavian vein and phrenic nerve pass anteriorly to the anterior scalene as it crosses over the first rib. Thoracic outlet syndrome The scalenes are at risk of adhering to the fascia surrounding the brachial plexus or shortening causing compression of the brachial plexus when it passes between the clavicle and 1st rib causing thoracic outlet syndrome.

Answer 994

The description fits with Heberdens nodes. These are bony outgrowths that occur in the distal interphalangeal joint in association with osteoarthritis. They may skew the finger tip sideways. Bouchards nodes are similar, but affect the proximal interphalangeal joint. Hand diseases Dupuytrens contracture Fixed flexion contracture of the hand where the fingers bend towards the palm and cannot be fully extended. Caused by underlying contractures of the palmar aponeurosis . The ring finger and little finger are the fingers most commonly affected. The middle finger may be affected in advanced cases, but the index finger and the thumb are nearly always spared. Progresses slowly and is usually painless. In patients with this condition, the tissues under the skin on the palm of the hand thicken and shorten so that the tendons connected to the fingers cannot move freely. The palmar aponeurosis becomes hyperplastic and undergoes contracture. Commonest in males over 40 years of age. Association with liver cirrhosis and alcoholism. However, many cases are idiopathic. Treatment is surgical and involves fasciectomy. However, the condition may recur and many surgical therapies are associated with risk of neurovascular damage to the digital nerves and arteries. Carpal tunnel syndrome Idiopathic median neuropathy at the carpal tunnel. Characterised by altered sensation of the lateral 3 fingers. The condition is commoner in females and is associated with other connective tissue disorders such as rheumatoid disease. It may also occur following trauma to the distal radius. Symptoms occur mainly at night in early stages of the condition. Examination may demonstrate wasting of the muscles of the thenar eminence and symptoms may be reproduced by Tinels test (compression of the contents of the carpal tunnel). Formal diagnosis is usually made by electrophysiological studies. Treatment is by surgical decompression of the carpal tunnel, a procedure achieved by division of the flexor retinaculum. Non - surgical options include splinting and bracing. Miscellaneous hand lumps Osler's nodes Osler's nodes are painful, red, raised lesions found on the hands and feet. They are the result of the deposition of immune complexes. Bouchard's nodes Hard, bony outgrowths or gelatinous cysts on the proximal interphalangeal joints (the middle joints of fingers or toes.) They are a sign of osteoarthritis, and are caused by formation of calcific spurs of the articular cartilage. Heberden's nodes Typically develop in middle age, beginning either with a chronic swelling of the affected joints or the sudden painful onset of redness, numbness, and loss of manual dexterity. This initial inflammation and pain eventually subsides, and the patient is left with a permanent bony outgrowth that often skews the fingertip sideways. It typically affects the DIP joint. Ganglion Swelling in association with a tendon sheath commonly near a joint. They are common lesions in the wrist and hand. Usually they are asymptomatic and cause little in the way of functional compromise. They are fluid filled although the fluid is similar to synovial fluid it is slightly more viscous. When the cysts are troublesome they may be excised.

Answer 995

The most likely diagnosis is an anterior MI. As there are no ST changes in the inferior leads, aortic dissection is less likely. Chest pain Aortic dissection This occurs when there is a flap or filling defect within the aortic intima. Blood tracks into the medial layer and splits the tissues with the subsequent creation of a false lumen. It most commonly occurs in the ascending aorta or just distal to the left subclavian artery (less common). It is most common in Afro-carribean males aged 50-70 years. Patients usually present with a tearing intrascapular pain, which may be similar to the pain of a myocardial infarct. The dissection may spread either proximally or distally with subsequent disruption to the arterial branches that are encountered. In the Stanford classification system the disease is classified into lesions with a proximal origin (Type A) and those that commence distal to the left subclavian (Type B). Diagnosis may be suggested by a chest x-ray showing a widened mediastinum. Confirmation of the diagnosis is usually made by use of CT angiography Proximal (Type A) lesions are usually treated surgically, type B lesions are usually managed non operatively. Pulmonary embolism Typically sudden onset of chest pain, haemoptysis, hypoxia and small pleural effusions may be present. Most patients will have an underlying deep vein thrombosis Diagnosis may be suggested by various ECG findings including S waves in lead I, Q waves in lead III and inverted T waves in lead III. Confirmation of the diagnosis is usually made through use of CT pulmonary angiography. Treatment is with anticoagulation, in those patients who develop a cardiac arrest or severe compromise from their PE, consideration may be given to thrombolysis. Myocardial infarction Traditionally described as sudden onset of central, crushing chest pain. It may radiate into the neck and down the left arm. Signs of autonomic dysfunction may be present. The presenting features may be atypical in the elderly and those with diabetes. Diagnosis is made through identification of new and usually dynamic ECG changes (and cardiac enzyme changes). Inferior and anterior infarcts may be distinguished by the presence of specific ECG changes (usually II, III and aVF for inferior, leads V1-V5 for anterior). Treatment is with oral antiplatelet agents, primary coronary angioplasty and/ or thrombolysis. Perforated peptic ulcer Patients usually develop sudden onset of epigastric abdominal pain, it may be soon followed by generalised abdominal pain. There may be features of antecendant abdominal discomfort, the pain of gastric ulcer is typically worse immediately after eating. Diagnosis may be made by erect chest x-ray which may show a small amount of free intra-abdominal air (very large amounts of air are more typically associated with colonic perforation). Treatment is usually with a laparotomy, small defects may be excised and overlaid with an omental patch, larger defects are best managed with a partial gastrectomy. Boerhaaves syndrome Spontaneous rupture of the oesophagus that occurs as a result of repeated episodes of vomiting. The rupture is usually distally sited and on the left side. Patients usually give a history of sudden onset of severe chest pain that may complicate severe vomiting. Severe sepsis occurs secondary to mediastinitis. Diagnosis is CT contrast swallow. Treatment is with thoracotomy and lavage, if less than 12 hours after onset then primary repair is usually feasible, surgery delayed beyond 12 hours is best managed by insertion of a T tube to create a controlled fistula between oesophagus and skin. Delays beyond 24 hours are associated with a very high mortality rate.

Answer 996

Leriche syndrome Classically, it is described in male patients as a triad of symptoms: 1. Claudication of the buttocks and thighs 2. Atrophy of the musculature of the legs 3. Impotence (due to paralysis of the L1 nerve) Leriche syndrome, is atherosclerotic occlusive disease involving the abdominal aorta and/or both of the iliac arteries. Management involves correcting underlying risk factors such as hypercholesterolaemia and stopping smoking. Investigation is usually with angiography. Leriche syndrome Atheromatous disease involving the iliac vessels. Blood flow to the pelvic viscera is compromised. Patients may present with buttock claudication and impotence (in this particular syndrome). Diagnostic work up will include angiography, where feasible, iliac occlusions are usually treated with endovascular angioplasty and stent insertion.

Answer 997

The carpal tunnel contains nine flexor tendons: Flexor digitorum profundus Flexor digitorum superficialis Flexor pollicis longus The tendon of flexor digitorum profundus lies deepest in the tunnel and will thus lie nearest to the hamate bone. Carpal bones The wrist is comprised of 8 carpal bones, these are arranged in two rows of 4. It is convex from side to side posteriorly and concave anteriorly. Diagrammatic image of carpal bones Key to image A Scaphoid B Lunate C Triquetrum D Pisiform E Trapezium F Trapezoid G Capitate H Hamate 1 Radius 2 Ulna 3 Metacarpals No tendons attach to: Scaphoid, lunate, triquetrum (stabilised by ligaments)

Answer 998

Gastrin: From G cells: stimulates gastric acid production Pepsin: Digestion of protein, secretion occurs simultaneously with gastrin Secretin: From mucosal cells in the duodenum and jejunum: inhibits gastric acid, stimulates bile and pancreatic juice production Gastric inhibitory peptide: (produced in response to fatty acids) inhibits gastrin release and acid secretion from parietal cells Cholecystokinin: From mucosal cells in the duodenum and jejunum (produced in response to fatty acids) inhibits acid secretion from parietal cells, causes gallbladder contraction and relaxation of sphincter of Oddi Somatostatin: From D cells Histamine released from enterochromaffin like cells then stimulates the acid-making cells (parietal cells) in a paracrine manner to increase gastric acid production. Hormonal control of gastric acid secretion Source Stimulus Actions Gastrin G cells in antrum of the stomach Distension of stomach, extrinsic nerves Inhibited by: low antral pH, somatostatin Increase HCL, pepsinogen and IF secretion, increases gastric motility, trophic effect on gastric mucosa CCK I cells in upper small intestine Partially digested proteins and triglycerides Increases secretion of enzyme-rich fluid from pancreas, contraction of gallbladder and relaxation of sphincter of Oddi, decreases gastric emptying, trophic effect on pancreatic acinar cells, induces satiety Secretin S cells in upper small intestine Acidic chyme, fatty acids Increases secretion of bicarbonate-rich fluid from pancreas and hepatic duct cells, decreases gastric acid secretion, trophic effect on pancreatic acinar cells VIP Small intestine, pancreas Neural Stimulates secretion by pancreas and intestines, inhibits acid and pepsinogen secretion Somatostatin D cells in the pancreas and stomach Fat, bile salts and glucose in the intestinal lumen Decreases acid and pepsin secretion, decreases gastrin secretion, decreases pancreatic enzyme secretion, decreases insulin and glucagon secretion inhibits trophic effects of gastrin, stimulates gastric mucous production

Answer 999

Tensor tympania and stapedius are the only two muscles of the middle ear. Contraction of tensor tympani will tend to dampen the vibrations produced by loud sounds, it is innervated by a branch of the trigeminal nerve. The stapedius dampens movements of the ossicles in response to loud sounds and is innervated by a branch of the facial nerve. The auriculotemporal nerve, which is derived from the mandibular branch of the trigeminal nerve supplies this area. Some areas may also be innervated by the vagus. Ear- anatomy The ear is composed of three anatomically distinct regions. External ear Auricle is composed of elastic cartilage covered by skin. The lobule has no cartilage and contains fat and fibrous tissue. External auditory meatus is approximately 2.5cm long. Lateral third of the external auditory meatus is cartilaginous and the medial two thirds is bony. The region is innervated by the greater auricular nerve. The auriculotemporal branch of the trigeminal nerve supplies most of the external auditory meatus and the lateral surface of the auricle. Middle ear Space between the tympanic membrane and cochlea. The aditus leads to the mastoid air cells is the route through which middle ear infections may cause mastoiditis. Anteriorly the eustacian tube connects the middle ear to the naso pharynx. The tympanic membrane consists of: Outer layer of stratified squamous epithelium. Middle layer of fibrous tissue. Inner layer of mucous membrane continuous with the middle ear. The tympanic membrane is approximately 1cm in diameter. The chorda tympani nerve passes on the medial side of the pars flaccida. The middle ear is innervated by the glossopharyngeal nerve and pain may radiate to the middle ear following tonsillectomy. Ossicles Malleus attaches to the tympanic membrane (the Umbo). Malleus articulates with the incus (synovial joint). Incus attaches to stapes (another synovial joint). Internal ear Cochlea, semi circular canals and vestibule Organ of corti is the sense organ of hearing and is located on the inside of the cochlear duct on the basilar membrane. Vestibule accommodates the utricule and the saccule. These structures contain endolymph and are surrounded by perilymph within the vestibule. The semicircular canals lie at various angles to the petrous temporal bone. All share a common opening into the vestibule.

Answer 1000

The interosseous membrane separates the anterior and posterior compartments. The deep and superficial compartments are separated by the deep transverse fascia. The peroneus brevis is part of the lateral compartment. Fascial compartments of the leg Compartments of the thigh Formed by septae passing from the femur to the fascia lata. Compartment Nerve Muscles Blood supply Anterior compartment Femoral Iliacus Tensor fasciae latae Sartorius Quadriceps femoris Femoral artery Medial compartment Obturator Adductor longus/magnus/brevis Gracilis Obturator externus Profunda femoris artery and obturator artery Posterior compartment (2 layers) Sciatic Semimembranosus Semitendinosus Biceps femoris Branches of Profunda femoris artery Compartments of the lower leg Separated by the interosseous membrane (anterior and posterior compartments), anterior fascial septum (separate anterior and lateral compartments) and posterior fascial septum (separate lateral and posterior compartments) Compartment Nerve Muscles Blood supply Anterior compartment Deep peroneal nerve Tibialis anterior Extensor digitorum longus Extensor hallucis longus Peroneus tertius Anterior tibial artery Posterior compartment Tibial Muscles: deep and superficial compartments (separated by deep transverse fascia) Deep: Flexor hallucis longus, Flexor digitalis longus, Tibialis posterior, Popliteus Superficial: Gastrocnemius, Soleus, Plantaris Posterior tibial Lateral compartment Superficial peroneal Peroneus longus/brevis Peroneal artery

Answer 1001

This is a Weber A fracture. It is a stable ankle injury and can therefore be managed conservatively. Whilst this patient could also be treated in a below knee plaster, most clinicians would nowadays treat this injury in an ankle boot. Patients should be advised to mobilise in the ankle boot, as pain allows, and can wean themselves out of the boot as the symptoms improve. Ankle injuries An ankle fracture relates to a fracture around the tibio-talar joint. It generally refers to a fracture involving the lateral, and/or medial and/or posterior malleolus. Pilon and Tillaux fractures are also considered to be ankle fractures, but are not covered here. Ankle fractures are common. They effect men and women in equal numbers, but men have a higher rate as young adults (sports and contact injuries), and women a higher rate post-menopausal (fragility type fracture). Osseous anatomy The ankle (or mortise) joint consists of the distal tibia (tibial plafond and posterior malleolus), the distal fibula (lateral malleolus), and the talus. The main movement at the ankle joint is plantar and dorsiflexion. Ligamentous anatomy Medial side: Deltoid ligament. This is divided into superficial and deep portions. It is the primary restraint to valgus tilting of the talus. Lateral side: Lateral ligament complex consisting from anterior to posterior of the anterior talofibular ligament (ATFL), calcaneofibular ligament (CFL), and the posterior talofibular ligament (PTFL). Together they resist valgus stress to the ankle, and are a restraint to anterior translation of the talus within the mortise joint. Syndesmosis: The syndesmosis is a ligament complex between the distal tibia and fibula, holding the two bones together. It is fundamental to the integrity of the ankle joint, and its disruption leads to instability. It consists of (from anterior to posterior) the anterior-inferior tibiofibular ligament (AITFL), the transverse tibiofibular ligament (TTFL), the interosseous membrane, and the posterior-inferior tibiofibular ligament (PITFL). Presentation and initial management Patients will present following a traumatic event with a painful, swollen ankle, and reluctance/inability to weight bear. The Ottawa rules can be applied to differentiate between an ankle fracture and sprain, but can be unreliable. In high energy injuries, management should follow ATLS principles to identify more significant injuries first. Neurovascular status of the foot should be documented, and open injuries should be excluded. If an open injury is identified, it should be managed in line with BOAST 4 principles1. If an obvious deformity exists, it should be reduced as soon as possible with appropriate analgesia or conscious sedation. Radiographs of clearly deformed or dislocated joints are not necessary, and removing the pressure on the surrounding soft tissues from the underlying bony deformity is the priority. If the fracture pattern is not clinically obvious then plain radiographs are appropriate and will guide the subsequent manipulation during plaster-of-paris below knee backslab application. Imaging AP, lateral and mortise views (20 degrees internal rotation) are essential to evaluate fracture displacement and syndesmotic injury. Decreased tibiofibular overlap, medial joint clear space and lateral talar shift all indicate a syndesmotic injury. (In subtle cases of shift, imaging the uninjured ankle can be helpful as a proportion of the population have little or no tibiotalar overlap-reference 2.) Where there is suspicion of syndesmosis involvement in the absence of radiographic evidence, stress radiographs can be diagnostic. Complex fracture patterns (and increasingly posterior malleolar fractures) are best defined using CT. Classification The most commonly used classifications are Lauge-Hansen and Danis-Weber. Lauge-Hansen Comprises two parts: first part is the foot position, and the second part is the force applied. Useful for understanding the forces involved and therefore predict the ligamentous or bony injury. Results in four injury patterns: Supination - Adduction (SA) - 10-20% Supination - External rotation (SER) - 40-75% Pronation - Abduction (PA) - 5-20% Pronation - External rotation (PER) - 5-20% Not often used in clinical practice but good for understanding the principles of ankle fracture. Danis-Weber Commonly used. Based on the level of the fibula fracture in relation to the syndesmosis. The more proximal, the greater the risk of syndesmotic injury and therefore fracture instability. A - fracture below the level of the syndesmosis B - fracture at the level of the syndesmosis / level of the tibial plafond C - fracture above the level of the syndesmosis. This includes Maisonneuve fractures (proximal fibula fracture), which can be associated with ankle instability. Beware the high fibula fracture - it may be an ankle fracture! The Weber classification is based purely on the the lateral side. All injuries can include a medial or posterior bony or ligamentous injury which also dictates fracture stability (bimalleolar and trimalleolar fractures are more unstable). Treatment When deciding upon treatment for an ankle fracture, one must consider both the fracture and the patient. Diabetic patients and smokers are at greater risk of post-operative complication, especially wound problems and infection. Likewise, the long term outcome of post-traumatic arthritis from a malunited ankle fracture is extremely important for a young patient, but not as relevant in the elderly. Therefore, normal surgical decision processes apply as with all fractures. Defining stability of an ankle fracture underpins the treatment decision. Weber A - Unimalleolar Weber A Weber fractures by definition are stable and therefore can be mobilised fully weight bearing in an ankle boot. Weber C - Fractures tend to include syndesmotic disruption and are usually bimalleolar (either bony or ligamentous). They are therefore unstable and usually require operative fixation. In addition to the fracture fixation, the syndesmosis usually requires reconstruction/augmentation with screws to restore the joint integrity and function. Weber B - B fractures vary greatly. They can be part of a trimalleolar injury and therefore extremely unstable, requiring fixation. Alternatively, a uni-malleolar Weber B fracture can be a stable injury, and therefore mobilised immediately in an ankle boot. Defining the stability can be challenging, and often involves stress radiographs, or a trial of mobilisation and repeat radiographs. However, treating undisplaced ankle fractures in a below knee plaster, non-weight bearing for six weeks is still widely practised, and a safe approach. When operative fixation is appropriate, it is usually via open reduction and internal fixation using plates and screws. It must be carried out when soft tissue swelling has settled in order to minimise the risk of wound problems. This can often take a week to settle. The use of fibula nails is expanding, but is not yet mainstream. Ankle fractures can also be treated with external fixation, or with a hind foot nail in patients who need fixation but where soft tissue or bone quality is poor. Post operative management Ankle fractures generally take 6 weeks to unite enough to prevent secondary displacement. This is therefore an appropriate time period to keep a cast on in a conservatively managed patient. Weight bearing post-operatively depends on the quality of the fixation and bone quality, and preference varies between surgeons, ranging from aggressive early mobilisation to a period of non-weight bearing. Return to activities takes approximately three months, and often requires assistance of a physiotherapist to improve range-of-movement and muscle strengthening. References 1. http://www.boa.ac.uk/publications/boa-standards-trauma-boasts/ 2. Shah AS, Kadakia AR, Tan GJ, Karadsheh MS, Wolter TD, Sabb B. Radiographic evaluation of the normal distal tibiofibular syndesmosis. Foot Ankle Int. 2012;33(10):870-6

Answer 1002

3 divisions of the pudendal nerve: Rectal nerve Perineal nerve Dorsal nerve of penis/ clitoris All these pass through the greater sciatic foramen. The pudendal nerve innervates the perineum. It passes between piriformis and coccygeus medial to the sciatic nerve. Gluteal region Gluteal muscles Gluteus maximus: inserts to gluteal tuberosity of the femur and iliotibial tract Gluteus medius: attach to lateral greater trochanter Gluteus minimis: attach to anterior greater trochanter All extend and abduct the hip Deep lateral hip rotators Piriformis Gemelli Obturator internus Quadratus femoris Nerves Superior gluteal nerve (L4,L5, S1) Gluteus medius Gluteus minimis Tensor fascia lata Inferior gluteal nerve (L5, S1, S2) Gluteus maximus Damage to the superior gluteal nerve will result in the patient developing a Trendelenberg gait. Affected patients are unable to abduct the thigh at the hip joint. During the stance phase, the weakened abductor muscles allow the pelvis to tilt down on the opposite side. To compensate, the trunk lurches to the weakened side to attempt to maintain a level pelvis throughout the gait cycle. The pelvis sags on the opposite side of the lesioned superior gluteal nerve.

Answer 1003

Embryological aortic arches - The aortic arches are a series of six paired embryological vascular structures which give rise to the great arteries of the neck and head. The first and second arches disappear early. A remnant of the 1st arch forms part of the maxillary artery. The external carotid buds from the horns of the aortic sac left behind by the regression of the first two arches. The third aortic arch constitutes the commencement of the internal carotid artery, and is therefore named the carotid arch. It contributes to the common carotid artery and the proximal portion of the internal carotid artery. The fourth right arch forms the right subclavian as far as the origin of its internal mammary branch. The fourth left arch forms the arch of the aorta between the origin of the left carotid artery and the termination of the ductus arteriosus. The fifth arch regresses or forms incompletely. The proximal part of the sixth right arch persists as the proximal part of the right pulmonary artery while the distal section degenerates; The sixth left arch gives off the left pulmonary artery and forms the ductus arteriosus.

Answer 1004

Do not confuse the management of pneumothorax due to trauma with the management of spontaneous uncomplicated pneumothorax. For a rib fracture to cause a pneumothorax, there must also be laceration to the underlying lung parenchyma. This has the risk of developing into a tension pneumothorax and for this reason a chest drain should be inserted and the patient admitted. Thoracic trauma Key points related to thoracic trauma Less than 10% of blunt chest trauma and 15-30% of penetrating chest trauma requires operative intervention. The physiologic consequences of thoracic trauma are hypoxia, hypercarbia, and acidosis. Contusion, hematoma, and alveolar collapse, or changes in intrathoracic pressure relationships (e.g., tension pneumothorax and open pneumothorax) cause hypoxia and lead to metabolic acidosis. Hypercarbia causes respiratory acidosis and most often follows inadequate ventilation caused by changes in intrathoracic pressure relationships and depressed level of consciousness. Types of thoracic trauma Tension pneumothorax Often laceration to lung parenchyma with flap Pressure develops in thorax Most common cause is mechanical ventilation in patient with pleural injury Symptoms overlap with cardiac tamponade, hyper-resonant percussion note is more likely in tension pnemothorax Flail chest Chest wall disconnects from thoracic cage Multiple rib fractures (at least two fractures per rib in at least two ribs) Associated with pulmonary contusion Abnormal chest motion Avoid over hydration and fluid overload Pneumothorax Most common cause is lung laceration with air leakage Most traumatic pneumothoraces should have a chest drain Patients with traumatic pneumothorax should never be mechanically ventilated until a chest drain is inserted Haemothorax Most commonly due to laceration of lung, intercostal vessel or internal mammary artery Haemothoraces large enough to appear on CXR are treated with large bore chest drain Surgical exploration is warranted if >1500ml blood drained immediately Cardiac tamponade Beck's triad: elevated venous pressure, reduced arterial pressure, reduced heart sounds Pulsus paradoxus May occur with as little as 100ml blood Pulmonary contusion Most common potentially lethal chest injury Arterial blood gases and pulse oximetry important Early intubation within an hour if significant hypoxia Blunt cardiac injury Usually occurs secondary to chest wall injury ECG may show features of myocardial infarction Sequelae: hypotension, arrhythmias, cardiac wall motion abnormalities Aorta disruption Deceleration injuries Contained haematoma Widened mediastinum Diaphragm disruption Most due to motor vehicle accidents and blunt trauma causing large radial tears (laceration injuries result in small tears) More common on left side Insert gastric tube, may pass into intrathoracic stomach Mediastinal traversing wounds Entrance wound in one hemithorax and exit wound/foreign body in opposite hemithorax Mediastinal haematoma or pleural cap suggests great vessel injury Mortality is 20% References ATLS Manual 10th Edition. ISBN 78-0-9968262-3-5

Answer 1005

Mnemonic for the branches of the subclavian artery: VIT C & D V ertebral artery I nternal thoracic T hyrocervical trunk C ostalcervical trunk D orsal scapular Superior thyroid artery is a branch of the external carotid artery. Subclavian artery Path The left subclavian comes directly off the arch of aorta The right subclavian arises from the brachiocephalic artery (trunk) when it bifurcates into the subclavian and the right common carotid artery. From its origin, the subclavian artery travels laterally, passing between anterior and middle scalene muscles, deep to scalenus anterior and anterior to scalenus medius. As the subclavian artery crosses the lateral border of the first rib, it becomes the axillary artery. At this point it is superficial and within the subclavian triangle. Branches Vertebral artery Internal thoracic artery Thyrocervical trunk Costocervical trunk Dorsal scapular artery

Answer 1006

Elevated thyroglobulin levels raises suspicion of recurrence. Thyroid malignancy Papillary carcinoma Commonest sub-type Accurately diagnosed on fine needle aspiration cytology Histologically, they may demonstrate psammoma bodies (areas of calcification) and so called 'orphan Annie' nuclei They typically metastasise via the lymphatics and thus laterally located apparently ectopic thyroid tissue is usually a metastasis from a well differentiated papillary carcinoma Follicular carcinoma Are less common than papillary lesions Like papillary tumours, they may present as a discrete nodule. Although they appear to be well encapsulated macroscopically there is invasion on microscopic evaluation Lymph node metastases are uncommon and these tumours tend to spread haematogenously. This translates into a higher mortality rate Follicular lesions cannot be accurately diagnosed on fine needle aspiration cytology and thus all follicular FNA's (THY 3f) will require at least a hemi thyroidectomy Anaplastic carcinoma Less common and tend to occur in elderly females Disease is usually advanced at presentation and often only palliative decompression and radiotherapy can be offered. Medullary carcinoma These are tumours of the parafollicular cells ( C Cells) and are of neural crest origin. The serum calcitonin may be elevated which is of use when monitoring for recurrence. They may be familial and occur as part of the MEN -2A disease spectrum. Spread may be either lymphatic or haematogenous and as these tumours are not derived primarily from thyroid cells they are not responsive to radioiodine. Lymphoma These respond well to combined chemoradiotherapy Radical surgery is unnecessary once the disease has been diagnosed on biopsy material. Such biopsy material is not generated by an FNA and thus a core biopsy has to be obtained (with care!).

Answer 1007

Ulnar nerve. The radial nerve is located near the lateral epicondyle. Ulnar nerve Origin C8, T1 Supplies (no muscles in the upper arm) Flexor carpi ulnaris Flexor digitorum profundus Flexor digiti minimi Abductor digiti minimi Opponens digiti minimi Adductor pollicis Interossei muscle Third and fourth lumbricals Palmaris brevis Path Posteromedial aspect of upper arm to flexor compartment of forearm, then along the ulnar. Passes beneath the flexor carpi ulnaris muscle, then superficially over the flexor retinaculum into the palm of the hand. Branches Branch Supplies Muscular branch Flexor carpi ulnaris Medial half of the flexor digitorum profundus Palmar cutaneous branch (Arises near the middle of the forearm) Skin on the medial part of the palm Dorsal cutaneous branch Dorsal surface of the medial part of the hand Superficial branch Cutaneous fibres to the anterior surfaces of the medial one and one-half digits Deep branch Hypothenar muscles All the interosseous muscles Third and fourth lumbricals Adductor pollicis Medial head of the flexor pollicis brevis Effects of injury Damage at the wrist Wasting and paralysis of intrinsic hand muscles (claw hand) Wasting and paralysis of hypothenar muscles Loss of sensation medial 1 and half fingers Damage at the elbow Radial deviation of the wrist Clawing less in 4th and 5th digits

Answer 1008

Femoral canal The femoral canal lies at the medial aspect of the femoral sheath. The femoral sheath is a fascial tunnel containing both the femoral artery laterally and femoral vein medially. The canal lies medial to the vein. Borders of the femoral canal Laterally Femoral vein Medially Lacunar ligament Anteriorly Inguinal ligament Posteriorly Pectineal ligament Contents Lymphatic vessels Cloquet's lymph node Physiological significance Allows the femoral vein to expand to allow for increased venous return from the lower limbs. Pathological significance As a potential space, it is the site of femoral hernias. The relatively tight neck places these at high risk of strangulation.

Answer 1009

Ribs. Chordoma is a neoplasm originating from ectopic cellular remnants of the notochord and therefore arises from the midline of the axial skeleton. It accounts for 24% of all primary malignant bone tumours. Chordoma is the second commonest primary malignancy of the spine and accounts for over 50% of primary sacral tumours. The neoplasm has a predilection for the sacrococcygeal (50%) and clival (40%) regions, with other areas of the spine rarely involved. More than one vertebral body can be affected in half the cases. Chordomas most commonly present between 50 and 70 years of age. Sex incidence is equal below 40 years, but men are affected twice as often at older ages, particularly in the sacral region. The most frequent radiographic appearance of chordoma is that of a destructive lesion of a vertebral body centered in the midline, with a large, associated soft-tissue mass. Chordoma Chordoma is a rare slow-growing bone tumour. Their favored origin is remnants of the notochord. Chordomas can arise anywhere from the skull base to the sacrum. The two most common locations are the skull base and sacrum. There are three histological variants of chordoma: classical (or 'conventional'), chondroid and de-differentiated. The histological appearance of classical chordoma is of a lobulated tumor composed of groups of cells separated by fibrous septa. The cells have small round nuclei and abundant vacuolated cytoplasm. Chondroid chordomas histologically show features of both chordoma and chondrosarcoma. The 10-year tumor free survival rate for sacral chordoma was 46%. Chondroid chordomas appear to have a more indolent clinical course. In most cases, complete surgical resection followed by radiation therapy offers the best chance of long-term control. Unfortunately, the lesion has a close proximity to the spine itself and this can compromise resection margins. Chordomas are relatively radioresistant, requiring high doses of radiation to be controlled. The proximity of chordomas to vital neurological structures such as the brain stem and nerves limits the dose of radiation that can safely be delivered. Therefore, highly focused radiation such as proton therapy and carbon ion therapy are more effective than conventional x-ray radiation.

Answer 1010

The gastroduodenal artery divides into the gastro-epiploic and pancreaticoduodenal arteries at the superior aspect of the pancreas. Pancreas The pancreas is a retroperitoneal organ and lies posterior to the stomach. It may be accessed surgically by dividing the peritoneal reflection that connects the greater omentum to the transverse colon. The pancreatic head sits in the curvature of the duodenum. Its tail lies close to the hilum of the spleen, a site of potential injury during splenectomy. Relations Posterior to the pancreas Pancreatic head Inferior vena cava Common bile duct Right and left renal veins Superior mesenteric vein and artery Pancreatic neck Superior mesenteric vein, portal vein Pancreatic body- Left renal vein Crus of diaphragm Psoas muscle Adrenal gland Kidney Aorta Pancreatic tail Left kidney Anterior to the pancreas Pancreatic head 1st part of the duodenum Pylorus SMA and SMV(uncinate process) Pancreatic body Stomach Duodenojejunal flexure Pancreatic tail Splenic hilum Superior to the pancreas Coeliac trunk and its branches common hepatic artery and splenic artery Grooves of the head of the pancreas 2nd and 3rd part of the duodenum Arterial supply Head: pancreaticoduodenal artery Rest: splenic artery Venous drainage Head: superior mesenteric vein Body and tail: splenic vein Ampulla of Vater Merge of pancreatic duct and common bile duct Is an important landmark, halfway along the second part of the duodenum, that marks the anatomical transition from foregut to midgut (also the site of transition between regions supplied by coeliac trunk and SMA).

Answer 1011

TCC is a rare form of renal cancer, accounting for approximately 7% of all renal tumours. Risk factors include exposure to chemicals in the textile, plastic and rubber industry. Renal lesions Lesion Disease specific features Treatment Renal cell carcinoma Most present with haematuria (50%) Common renal tumour (85% cases) Paraneoplastic features include hypertension and polycythaemia Most commonly has haematogenous mestastasis Usually radical or partial nephrectomy Nephroblastoma Rare childhood tumour It accounts for 80% of all genitourinary malignancies in those under the age of 15 years Up to 90% will have a mass 50% will be hypertensive Diagnostic work up includes ultrasound and CT scanning Surgical resection combined with chemotherapy (usually vincristine, actinomycin D and doxorubicin) Neuroblastoma Most common extracranial tumour of childhood 80% occur in those under 4 years of age Tumour of neural crest origin (up to 50% occur in the adrenal gland) The tumour is usually calcified and may be diagnosed using MIBG scanning Staging is with CT Surgical resection, radiotherapy and chemotherapy Transitional cell carcinoma Accounts for 90% of lower urinary tract tumours, but only 10% of renal tumours Males affected 3x more than females Occupational exposure to industrial dyes and rubber chemicals may increase risk Up to 80% present with painless haematuria Diagnosis and staging is with CT IVU Radical nephroureterectomy Angiomyolipoma 80% of these hamartoma type lesions occur sporadically, the remainder are seen in those with tuberous sclerosis Tumour is composed of blood vessels, smooth muscle and fat Massive bleeding may occur in 10% of cases

Answer 1012

Combined chemoradiotherapy is the standard treatment for anal cancer First line treatment for anal cancer (which is very different from rectal cancer) is radical chemoradiotherapy. Anal cancer - Cancers arising from the squamous epithelium of the anal canal Arise inferior to the dentate line Strongly linked to HPV type 16 infection Other risk factors include ano-receptive intercourse, smoking and immunosuppression Presenting symptoms include anal discomfort, discharge or pruritus Lymphatic spread typically occurs to the inguinal nodes Diagnosis is made by EUA and biopsies Staging is with CT scanning of the chest, abdomen and pelvis First line treatment is typically with chemoradiotherapy Second line treatment for non metastatic disease is with salvage radical abdominoperineal excision of the anus and rectum

Answer 1013

Median. Motor supply: LOAF L ateral 2 lumbricals O pponens pollicis A bductor pollicisbrevis F lexor pollicis brevis The most likely diagnosis here is carpal tunnel syndrome, the median nerve is compressed in the wrist and symptoms usually affect the fingers and wrist either at night or when the hand is being used (e.g. as a typist). Median nerve The median nerve is formed by the union of a lateral and medial root respectively from the lateral (C5,6,7) and medial (C8 and T1) cords of the brachial plexus; the medial root passes anterior to the third part of the axillary artery. The nerve descends lateral to the brachial artery, crosses to its medial side (usually passing anterior to the artery). It passes deep to the bicipital aponeurosis and the median cubital vein at the elbow. It passes between the two heads of the pronator teres muscle, and runs on the deep surface of flexor digitorum superficialis (within its fascial sheath). Near the wrist it becomes superficial between the tendons of flexor digitorum superficialis and flexor carpi radialis, deep to palmaris longus tendon. It passes deep to the flexor retinaculum to enter the palm, but lies anterior to the long flexor tendons within the carpal tunnel. Branches Region Branch Upper arm No branches, although the nerve commonly communicates with the musculocutaneous nerve Forearm Pronator teres Pronator quadratus Flexor carpi radialis Palmaris longus Flexor digitorum superficialis Flexor pollicis longus Flexor digitorum profundus (only the radial half) Distal forearm Palmar cutaneous branch Hand (Motor) Motor supply (LOAF) Lateral 2 lumbricals Opponens pollicis Abductor pollicis brevis Flexor pollicis brevis Hand (Sensory) Over thumb and lateral 2 Â½ fingers On the palmar aspect this projects proximally, on the dorsal aspect only the distal regions are innervated with the radial nerve providing the more proximal cutaneous innervation. Patterns of damage Damage at wrist e.g. carpal tunnel syndrome paralysis and wasting of thenar eminence muscles and opponens pollicis (ape hand deformity) sensory loss to palmar aspect of lateral (radial) 2 Â½ fingers Damage at elbow, as above plus: unable to pronate forearm weak wrist flexion ulnar deviation of wrist Anterior interosseous nerve (branch of median nerve) leaves just below the elbow results in loss of pronation of forearm and weakness of long flexors of thumb and index finger

Answer 1014

Hypertension and bradycardia are seen prior to coning. The brain autoregulates its blood supply by controlling systemic blood pressure. Head injury Patients who suffer head injuries should be managed according to ATLS principles and extra cranial injuries should be managed alongside cranial trauma. Inadequate cardiac output will compromise CNS perfusion irrespective of the nature of the cranial injury. Types of traumatic brain injury Extradural haematoma Bleeding into the space between the dura mater and the skull. Often results from acceleration-deceleration trauma or a blow to the side of the head. The majority of extradural haematomas occur in the temporal region where skull fractures cause a rupture of the middle meningeal artery. Features Raised intracranial pressure Some patients may exhibit a lucid interval Subdural haematoma Bleeding into the outermost meningeal layer. Most commonly occur around the frontal and parietal lobes. May be either acute or chronic. Risk factors include old age and alcoholism. Slower onset of symptoms than a extradural haematoma. Subarachnoid haemorrhage Usually occurs spontaneously in the context of a ruptured cerebral aneurysm, but may be seen in association with other injuries when a patient has sustained a traumatic brain injury. Pathophysiology Primary brain injury may be focal (contusion/ haematoma) or diffuse (diffuse axonal injury) Diffuse axonal injury occurs as a result of mechanical shearing following deceleration, causing disruption and tearing of axons Intra-cranial haematomas can be extradural, subdural or intracerebral, while contusions may occur adjacent to (coup) or contralateral (contre-coup) to the side of impact Secondary brain injury occurs when cerebral oedema, ischaemia, infection, tonsillar or tentorial herniation exacerbates the original injury. The normal cerebral auto regulatory processes are disrupted following trauma rendering the brain more susceptible to blood flow changes and hypoxia The Cushings reflex (hypertension and bradycardia) often occurs late and is usually a pre terminal event Management Where there is life threatening rising ICP such as in extra dural haematoma and whilst theatre is prepared or transfer arranged use of IV mannitol/ frusemide may be required. Diffuse cerebral oedema may require decompressive craniotomy Exploratory Burr Holes have little management in modern practice except where scanning may be unavailable and to thus facilitate creation of formal craniotomy flap Depressed skull fractures that are open require formal surgical reduction and debridement, closed injuries may be managed non operatively if there is minimal displacement. ICP monitoring is appropriate in those who have GCS 3-8 and normal CT scan. ICP monitoring is mandatory in those who have GCS 3-8 and abnormal CT scan. Hyponatraemia is most likely to be due to syndrome of inappropriate ADH secretion. Minimum of cerebral perfusion pressure of 70mmHg in adults. Minimum cerebral perfusion pressure of between 40 and 70 mmHg in children. Interpretation of pupillary findings in head injuries Pupil size Light response Interpretation Unilaterally dilated Sluggish or fixed 3rd nerve compression secondary to tentorial herniation Bilaterally dilated Sluggish or fixed Poor CNS perfusion Bilateral 3rd nerve palsy Unilaterally dilated or equal Cross reactive (Marcus - Gunn) Optic nerve injury Bilaterally constricted May be difficult to assess Opiates Pontine lesions Metabolic encephalopathy Unilaterally constricted Preserved Sympathetic pathway disruption

Answer 1015

Data from multiple RCT's are best displayed using Forest plots. Funnel plots may be used to determine the effect of small studies and their overall effect on the data. Violin plots and Box Whisker plots are often used to graphically display non parametric data from single studies and are not generally used to display data from meta analyses. Forest plots A Forest plot is a graphical display designed to illustrate the relative strength of treatment effects in multiple quantitative scientific studies, addressing the same question. It is often used to graphically display meta analyses of randomised controlled trials. The graph may be plotted on a natural logarithmic scale when using odds ratios or other ratio-based effect measures, so that the confidence intervals are symmetrical about the means from each study and to ensure undue emphasis is not given to odds ratios greater than 1 when compared to those less than 1. The area of each square is proportional to the study's weight in the meta-analysis. The overall meta-analysed measure of effect is often represented on the plot as a vertical line. This meta-analysed measure of effect is commonly plotted as a diamond, the lateral points of which indicate confidence intervals for this estimate. A vertical line representing no effect is also plotted. If the confidence intervals for individual studies overlap with this line, it demonstrates that at the given level of confidence their effect sizes do not differ from no effect for the individual study. The same applies for the meta-analysed measure of effect: if the points of the diamond overlap the line of no effect the overall meta-analysed result cannot be said to differ from no effect at the given level of confidence.

Answer 1016

Amyloidosis = apple green birefringence with polarised light Amyloid Amyloid is an extracellular protein deposit which is insoluble. These deposits disrupt normal tissue structure and if excessive may affect function. All types of amyloid consist of a major fibrillar protein that defines the type of amyloid (approximately 90%) plus various minor components. Amyloid is classified with the prefix A (for amyloid) and the suffix depending upon the fibrillary protein present. The main clinical types are AA and AL amyloidosis. Systemic AA amyloidosis is a long-term complication of several chronic inflammatory disorders - e.g. rheumatoid arthritis, ankylosing spondylitis, Crohn's disease, malignancies and conditions predisposing to recurrent infections. AL amyloidosis results from extra-cellular deposition of fibril-forming monoclonal immunoglobulin light chains (most commonly of lambda isotype). Most patients have evidence of isolated monoclonal gammopathy or asymptomatic myeloma, and the occurrence of AL amyloidosis in patients with symptomatic multiple myeloma or other B-cell lymphoproliferative disorders is unusual. AL type amyloidosis is the most common variant. The kidney and heart are two of the most commonly affected sites. Diagnosis is based on surgical biopsy and characteristic histological features which consist birefringence under polarised light. Immunohistochemistry is used to delineate the subtype. Treatment is usually targeted at the underlying cause.

Answer 1017

In straightforward uncomplicated laparoscopic cholecystectomy the wound infection rates are around 3-5% (Pasquali et al and Matsui et al). The use of antibiotics in this group is therefore unnecessary. Complex procedures, bile spills and acute cholecystectomy have higher infection rates and antibiotics should be administered to these patients. References: S Pasquali , M Boal , E A Griffiths , D Alderson , R S Vohra, CholeS Study Group; West Midlands Research Collaborative. Meta-analysis of perioperative antibiotics in patients undergoing laparoscopic cholecystectomy. Br J Surg. 2016 Jan;103(1):27-34 Yoichi Matsui, Sohei Satoi, Satoshi Hirooka, Hisashi Kosaka, Takayuki Kawaura, and Tomoki Kitawaki. Reappraisal of previously reported meta-analyses on antibiotic prophylaxis for low-risk laparoscopic cholecystectomy: an overview of systematic reviews. BMJ Open. 2018; 8(3): e016666. Surgical site infection - Surgical site infections may occur following a breach in tissue surfaces and allow normal commensals and other pathogens to initiate infection. They are a major cause of morbidity and mortality. Surgical site infections (SSI) comprise up to 20% of all healthcare associated infections and at least 5% of patients undergoing surgery will develop an SSI as a result. In many cases the organisms are derived from the patient's own body. Measures that may increase the risk of SSI include: Shaving the wound using a razor (disposable clipper preferred) Using a non iodine impregnated incise drape if one is deemed to be necessary Tissue hypoxia Delayed administration of prophylactic antibiotics in tourniquet surgery Preoperatively Don't remove body hair routinely If hair needs removal, use electrical clippers with single use head (razors increase infection risk) Antibiotic prophylaxis if: - placement of prosthesis or valve - clean-contaminated surgery - contaminated surgery Use local formulary Aim to give single dose IV antibiotic on anaesthesia If a tourniquet is to be used, give prophylactic antibiotics earlier Intraoperatively Prepare the skin with alcoholic chlorhexidine (Lowest incidence of SSI) Cover surgical site with dressing A recent meta analysis has confirmed that administration of supplementary oxygen does not reduce the risk of wound infection. In contrast to previous individual RCT's(1) Wound edge protectors do not appear to confer benefit (2) Post operatively Tissue viability advice for management of surgical wounds healing by secondary intention Use of diathermy for skin incisions In the NICE guidelines the use of diathermy for skin incisions is not advocated(3). Several randomised controlled trials have been undertaken and demonstrated no increase in risk of SSI when diathermy is used(4). References 1. Brar M et al.. Perioperative supplemental oxygen in colorectal patients: a meta analysis. J Surg Res 2011 (166): 227 -235. 2. Pinkney T et al. Impact of wound edge protection devices on surgical site infection after laparotomy: impact of a multicentre randomised controlled trial (ROSSINI Trial). BMJ 2013 (347):10. 3. http://www.nice.org.uk/CG74 4. Ahmad N and Ahmed A. Meta-analysis of the effectiveness of surgical scalpel or diathermy in making abdominal skin incisions. Ann Surg 2011, 253(1):8-13.

Answer 1018

The intestinal phase of gastric acid secretion accounts for only 10% of gastric acid produced. Gastric secretions A working knowledge of gastric secretions is important for surgery because peptic ulcers are common, surgeons frequently prescribe anti secretory drugs and because there are still patients around who will have undergone acid lowering procedures (Vagotomy) in the past. Gastric acid Is produced by the parietal cells in the stomach pH of gastric acid is around 2 with acidity being maintained by the H+/K+ ATP ase pump. As part of the process bicarbonate ions will be secreted into the surrounding vessels. Sodium and chloride ions are actively secreted from the parietal cell into the canaliculus. This sets up a negative potential across the membrane and as a result sodium and potassium ions diffuse across into the canaliculus. Carbonic anhydrase forms carbonic acid which dissociates and the hydrogen ions formed by dissociation leave the cell via the H+/K+ antiporter pump. At the same time sodium ions are actively absorbed. This leaves hydrogen and chloride ions in the canaliculus these mix and are secreted into the lumen of the oxyntic gland. Phases of gastric acid secretion There are 3 phases of gastric secretion: 1. Cephalic phase (smell / taste of food) 30% acid produced Vagal cholinergic stimulation causing secretion of HCL and gastrin release from G cells 2. Gastric phase (distension of stomach ) 60% acid produced Stomach distension/low H+/peptides causes Gastrin release 3. Intestinal phase (food in duodenum) 10% acid produced High acidity/distension/hypertonic solutions in the duodenum inhibits gastric acid secretion via enterogastrones (CCK, secretin) and neural reflexes. Regulation of gastric acid production Factors increasing production include: Vagal nerve stimulation Gastrin release Histamine release (indirectly following gastrin release) from enterchromaffin like cells Factors decreasing production include: Somatostatin (inhibits histamine release) Cholecystokinin Secretin Below is a brief summary of the major hormones involved in food digestion: Source Stimulus Actions Gastrin G cells in antrum of the stomach Distension of stomach, extrinsic nerves Inhibited by: low antral pH, somatostatin Increase HCL, pepsinogen and IF secretion, increases gastric motility, trophic effect on gastric mucosa CCK I cells in upper small intestine Partially digested proteins and triglycerides Increases secretion of enzyme-rich fluid from pancreas, contraction of gallbladder and relaxation of sphincter of Oddi, decreases gastric emptying, trophic effect on pancreatic acinar cells, induces satiety Secretin S cells in upper small intestine Acidic chyme, fatty acids Increases secretion of bicarbonate-rich fluid from pancreas and hepatic duct cells, decreases gastric acid secretion, trophic effect on pancreatic acinar cells VIP Small intestine, pancreas Neural Stimulates secretion by pancreas and intestines, inhibits acid and pepsinogen secretion Somatostatin D cells in the pancreas and stomach Fat, bile salts and glucose in the intestinal lumen Decreases acid and pepsin secretion, decreases gastrin secretion, decreases pancreatic enzyme secretion, decreases insulin and glucagon secretion inhibits trophic effects of gastrin, stimulates gastric mucous production

Answer 1019

PTH increases the activity of 1-α-hydroxylase enzyme, which converts 25-hydroxycholecalciferol to 1,25-dihydroxycholecalciferol, the active form of vitamin D. Osteoclasts do not have a PTH receptor and effects are mediated via osteoblasts. Parathyroid hormone Parathyroid hormone is secreted by the chief cells of the parathyroid glands. It acts to increase serum calcium concentration by stimulation of the PTH receptors in the kidney and bone. PTH has a plasma half life of 4 minutes. Effects of PTH Bone Binds to osteoblasts which signal to osteoclasts to cause resorption of bone and release calcium. Kidney Active reabsorption of calcium and magnesium from the distal convoluted tubule. Decreases reabsorption of phosphate. Intestine via kidney Increases intestinal calcium absorption by increasing activated vitamin D. Activated vitamin D increases calcium absorption.

Answer 1020

The mid inguinal point is midway between the anterior superior iliac spine and the symphysis pubis The mid inguinal point in the surface marking for the femoral artery. Femoral triangle anatomy Boundaries Superiorly Inguinal ligament Laterally Sartorius Medially Adductor longus Floor Iliopsoas, adductor longus and pectineus Roof Fascia lata and Superficial fascia Superficial inguinal lymph nodes (palpable below the inguinal ligament) Long saphenous vein Contents Femoral vein (medial to lateral) Femoral artery-pulse palpated at the mid inguinal point Femoral nerve Deep and superficial inguinal lymph nodes Lateral cutaneous nerve Great saphenous vein Femoral branch of the genitofemoral nerve

Answer 1021

In trauma, sudden development of hypoxia following intubation suggests a pneumothorax. Where there is concern and time permits, it is usually safer to insert a chest drain prior to intubation and if a trauma patient does require intubation at scene . It is often safer to prophylactically insert a chest drain prior to transfer. Pneumothorax Pneumothorax is a common medical problem. In surgical practice patients can be divided into those who sustain thoracic trauma with an associated pneumothorax and those who happen to be surgical patients for another reason and develop a pneumothorax. In some cases this may be a sudden spontaneous event. For others, it may be the result of iatrogenic injury. Initial approach ABCD approach High flow oxygen Adequate monitoring Early imaging (portable CXR) Traumatic pneumothorax The management of a traumatic pneumothorax is embodied in the ATLS principles. The most important decision to make and to make early, is whether the patient has a tension present. Signs of tension pneumothorax Severe respiratory distress Hyper-expanded chest Tracheal shift Hyperressonant percussion note Distended neck veins Decreased breath sounds If so then it must be immediately decompressed using a wide bore needle inserted in the fourth intercostal space in the mid axillary line. Once this has been undertaken, immediate steps should be taken to insert a chest drain. Traumatic pneumothoraxes may occur via a number of different mechanisms. Penetrating trauma may create a flap of lung tissue that can predispose to subsequent tension and for that reason, most would proceed to insert a chest drain if even a small pneumothorax were present by the underlying mechanism one of penetrating injury. One potential pitfall is to fail to appreciate that blunt mechanisms of injury to the chest wall may cause a rib fracture which is then able to inflict a penetrating lung injury. The insertion of chest drains for chest trauma is different from the seldinger sets that are often used by physicians. In trauma it is usual to insert a wide bore chest drain (between 30 and 34Fr) using an open technique (with trochar removed). Triangle of safety It is advised that chest drains are placed in the 'safe triangle'. The triangle is located in the mid axillary line of the 5th intercostal space. It is bordered by: Anterior edge latissimus dorsi, the lateral border of pectoralis major, a line superior to the horizontal level of the nipple, and the apex below the axilla. Non traumatic pneumothorax The management of these is governed by the British Thoracic Society Guidelines (which do not apply to trauma cases). When reviewing the chest x-rays for these cases it is useful to distinguish between large and small pneumothoraces, The differentiation of a large from a small pneumo-thorax continues to be the presence of a visible rim of >2 cm between the lung margin and the chest wall (at the level of the hilum). However, size does not correlate well with symptoms. The presence of small primary pneumothorax in a patient with no compromise may not require any specific treatment. Those with underlying lung disease or large pneumothoraces should be considered for aspiration or chest drain insertion. Where a chest drain is inserted, a small calibre drain is sufficient. Detailed management of these cases is usually provided by physicians with an interest in respiratory medicine and fall outside of the remit of general surgical practice (and thus the MRCS!) Whenever a chest drain or thoracic aspiration is performed, a check x-ray should be routinely performed following the intervention

Answer 1022

Seromas are very common after breast surgery. The exposed raw surfaces created during the elevation of the skin flaps are a common cause. Treatment usually involves percutaneous drainage under aseptic conditions. Complications of breast surgery Breast surgery may be associated with the following complications: Long thoracic nerve injury. This may occur during the axillary dissection and result in winging of the scapula. Intercostobrachial nerve injury. These nerves traverse the axilla. When they are divided (which they often are) the patient will notice an area of parasthesia in the armpit. Injury to the thoracodorsal trunk. This nerve and vessels supply latissimus dorsi. If they are damaged the functional effects are not too serious, the greatest setback is that a latissimus dorsi flap cannot be used for reconstruction purposes. Infections. Cellulitis of the chest wall and arm may be a major problem if axillary nodal clearance is undertaken. Infections may run a protracted course and require polytherapy for treatment. Lymphoedema. Usually complicates axillary node clearance or irradiation. Treatment is with manual lymphatic drainage and compression sleeves. Seroma. This is an accumulation of fluid at the site of surgery. The fluid is usually straw coloured and may re-accumulate despite drainage. Most will resolve with time.

Answer 1023

In young patients with proximal disease and healthy distal lymphatics a lymphovenous anastomosis may be considered. Such cases are rare. Lymphoedema - Due to impaired lymphatic drainage in the presence of normal capillary function. Lymphoedema causes the accumulation of protein rich fluid, subdermal fibrosis and dermal thickening. Characteristically fluid is confined to the epifascial space (skin and subcutaneous tissues); muscle compartments are free of oedema. It involves the foot, unlike other forms of oedema. There may be a 'buffalo hump' on the dorsum of the foot and the skin cannot be pinched due to subcutaneous fibrosis. Causes of lymphoedema Primary Congenital < 1 year: sporadic, Milroy's disease Onset 1-35 years: sporadic, Meige's disease > 35 years: Tarda Secondary Bacterial/fungal/parasitic infection (filariasis) Lymphatic malignancy Radiotherapy to lymph nodes Surgical resection of lymph nodes DVT Thrombophlebitis Indications for surgery Marked disability or deformity from limb swelling Lymphoedema caused by proximal lymphatic obstruction with patent distal lymphatics suitable for a lymphatic drainage procedure Lymphocutaneous fistulae and megalymphatics Procedures Homans operation Reduction procedure with preservation of overlying skin (which must be in good condition). Skin flaps are raised and the underlying tissue excised. Limb circumference typically reduced by a third. Charles operation All skin and subcutaneous tissue around the calf are excised down to the deep fascia. Split skin grafts are placed over the site. May be performed if overlying skin is not in good condition. Larger reduction in size than with Homans procedure. Lymphovenous anastamosis Identifiable lymphatics are anastomosed to sub dermal venules. Usually indicated in 2% of patients with proximal lymphatic obstruction and normal distal lymphatics.

Answer 1024

The heads of gastrocnemius will contract to pull the fracture segment posteriorly. The popliteal artery lies against the bone and may be damaged or compressed. Popliteal fossa Boundaries of the popliteal fossa Laterally Biceps femoris above, lateral head of gastrocnemius and plantaris below Medially Semimembranosus and semitendinosus above, medial head of gastrocnemius below Floor Popliteal surface of the femur, posterior ligament of knee joint and popliteus muscle Roof Superficial and deep fascia Contents Popliteal artery and vein Small saphenous vein Common peroneal nerve Tibial nerve Posterior cutaneous nerve of the thigh Genicular branch of the obturator nerve Lymph nodes

Answer 1025

The renal arteries usually branch off the aorta on a level with L2. Renal arteries The right renal artery is longer than the left renal artery The renal vein/artery/pelvis enter the kidney at the hilum Relations Right Anterior- IVC, right renal vein, the head of the pancreas, and the descending part of the duodenum Left Anterior- left renal vein, the tail of the pancreas Branches The renal arteries are direct branches off the aorta (upper border of L2- right side and L1 - left side) In 30% there may be accessory arteries (mainly left side). Instead of entering the kidney at the hilum, they usually pierce the upper or lower part of the organ. Before reaching the hilum of the kidney, each artery divides into four or five segmental branches (renal vein anterior and ureter posterior); which then divide within the sinus into lobar arteries supplying each pyramid and cortex. Each vessel gives off some small inferior suprarenal branches to the suprarenal gland, the ureter, and the surrounding cellular tissue and muscles.

Answer 1026

The superior thoracic artery is the first branch of the axillary artery arises from the first part Two branches arise from the second part, thoraco acromial and lateral thoracic Three branches from the third part, subscapular artery, anterior and posterior circumflex humeral arteries Mnemonic for axillary artery branches Screw The Lawyer Save A patient Superior thoracic artery Thoracoacromial artery Lateral thoracic artery Subscapular artery Anterior humeral circumflex artery Posterior humeral circumflex artery

Answer 1027

Hashimoto's thyroiditis is associated with thyroid lymphoma Rarely, a patient with Hashimotos thyroiditis may develop a lymphoma of the thyroid gland. The exact aetiology of thyroid gland lymphoma is unknown. Hashimotos thyroiditis is a definite risk factor. It is possible that the lymphoma may represent the expansion of a clone of immortalised intrathyroidal lymphocytes. Lymphoma of the gland is characterised by rapid thyroid growth despite T4 therapy. Whilst adenocarcinoma of the thyroid may occur in association with thyroiditis there are no studies, to date, showing a correlation between these two conditions. The commonest sequelae of thyroiditis is hypothyroidism. Thyroiditis Sub acute thyroiditis Subacute thyroiditis (also known as De Quervain's thyroiditis) is thought to occur following viral infection and typically presents with hyperthyroidism Features Hyperthyroidism Painful goitre Raised ESR Globally reduced uptake on iodine-131 scan Management Usually self-limiting - most patients do not require treatment Thyroid pain may respond to aspirin or other NSAIDs In more severe cases steroids are used, particularly if hypothyroidism develops Hashimotos thyroiditis Hashimotos thyroiditis is an immunological disorder in which lymphocytes become sensitised to thyroidal antigens. The three most important antibodies include; thyroglobulin, TPO and TSH-R. During the early phase of Hashimotos the the thyroglobulin antibody is markedly elevated and then declines. Features Goitre and either euthyroid or mild hypothyroidism Progressive hypothyroidism (and associated symptoms) Management During the hyperthyroid phase of illness beta blockers may manage symptoms As hypothyroidism develops patients may require thyroxine

Answer 1028

The ulnar nerve and artery lie adjacent to the pisiform bone. The capitate bone articulates with the lunate, scaphoid, hamate and trapezoid bones, which are therefore closely related to it. Capitate bone This is the largest of the carpal bones. It is centrally placed with a rounded head set into the cavities of the lunate and scaphoid bones. Flatter articular surfaces are present for the hamate medially and the trapezoid laterally. Distally the bone articulates predominantly with the middle metacarpal.

Answer 1029

Type 2 diabetics may have vessel calcification. This will result in abnormally high ABPI readings. Pain of this nature in diabetics is usually neuropathic and if a duplex scan is normal then treatment with an agent such as duloxetine is sometimes helpful. Ankle-Brachial pressure index Measurement of ankle- brachial pressure index (ABPI) is a commonly performed vascular investigation. Calculated by dividing lower limb pressure by the highest upper limb pressure. Results of ABPI 1.2 or greater Usually due to vessel calcification 1.0- 1.2 Normal 0.8-1.0 Minor stenotic lesion Initiate risk factor management 0.50-0.8 Moderate stenotic lesion Consider duplex Risk factor management If mixed ulcers present then avoid tight compression bandages 0.3 - 0.5 Likely significant stenosis Duplex scanning to delineate lesions needed Compression bandaging contra indicated Less than 0.3 Indicative of critical ischaemia Urgent detailed imaging required

Answer 1030

Mesenteric cysts are often smooth. Imaging with ultrasound and CT is usually sufficient. Although rare, they most often occur in young children (up to 30% present before the age of 15). Many are asymptomatic and discovered incidentally. Acute presentations are recognised and may occur following cyst torsion, infarction or rupture. Most cysts will be surgically resected. Spigelian hernias are very rare in children, liposarcomas are not smooth swellings. An appendix mass will usually produce systemic illness. Right iliac fossa pain Differential diagnosis Appendicitis Pain radiating to right iliac fossa Anorexia (very common) Short history Diarrhoea and profuse vomiting rare Crohn's disease Often long history Signs of malnutrition Change in bowel habit, especially diarrhoea Mesenteric adenitis Mainly affects children Causes include Adenoviruses, Epstein Barr Virus, beta-haemolytic Streptococcus, Staphylococcus spp., Escherichia coli, Streptococcus viridans and Yersinia spp. Patients have a higher temperature than those with appendicitis If laparotomy is performed, enlarged mesenteric lymph nodes will be present Diverticulitis Both left and right sided disease may present with right iliac fossa pain Clinical history may be similar, although some change in bowel habit is usual When suspected, a CT scan may help in refining the diagnosis Meckel's diverticulitis A Meckel's diverticulum is a congenital abnormality that is present in about 2% of the population Typically 2 feet proximal to the ileocaecal valve May be lined by ectopic gastric mucosal tissue and produce bleeding Perforated peptic ulcer This usually produces upper quadrant pain but pain may be lower Perforations typically have a sharp sudden onset of pain in the history Incarcerated right inguinal or femoral hernia Usually only right iliac fossa pain if right sided or bowel obstruction. Bowel perforation secondary to caecal or colon carcinoma Seldom localised to right iliac fossa, although complete large bowel obstruction with caecal distension may cause pain prior to perforation. Gynaecological causes Pelvic inflammatory disease/salpingitis/pelvic abscess/Ectopic pregnancy/Ovarian torsion/Threatened or complete abortion/Mittelschmerz Urological causes Ureteric colic/UTI/Testicular torsion Other causes TB/Typhoid/Herpes Zoster/AAA/Situs inversus

Answer 1031

Cardiooesophageal junction level = T11 A knowledge of this anatomic level is commonly tested. The oesophagus extends from C6 (the lower border of the cricoid cartilage) to T11 at the cardioesophageal junction. Note that in the neonate the oesophagus extends from C4 or C5 to T9. Levels Transpyloric plane Level of the body of L1 Pylorus stomach Left kidney hilum (L1- left one!) Fundus of the gallbladder Neck of pancreas Duodenojejunal flexure Superior mesenteric artery Portal vein Left and right colic flexure Root of the transverse mesocolon 2nd part of the duodenum Upper part of conus medullaris Spleen Can be identified by asking the supine patient to sit up without using their arms. The plane is located where the lateral border of the rectus muscle crosses the costal margin. Anatomical planes Subcostal plane Lowest margin of 10th costal cartilage Intercristal plane Level of body L4 (highest point of iliac crest) Intertubercular plane Level of body L5 Common level landmarks Inferior mesenteric artery L3 Bifurcation of aorta into common iliac arteries L4 Formation of IVC L5 (union of common iliac veins) Diaphragm apertures Vena cava T8 Oesophagus T10 Aortic hiatus T12

Answer 1032

In most patients with Pagets disease, an underlying mammary carcinoma will be found. Paget's is associated with DCIS or invasive carcinoma. Unlike eczema of the nipple which predominantly affects the areolar region, Pagets will usually affect the nipple first and then spread to the areolar area. Diagnosis is made by punch biopsy. Breast cancer - Commoner in the older age group Invasive ductal carcinomas are the most common type. Some may arise as a result of ductal carcinoma in situ (DCIS). There are associated carcinomas of special type e.g. Tubular that may carry better prognosis. The pathological assessment involves assessment of the tumour and lymph nodes, sentinel lymph node biopsy is often used to minimise the morbidity of an axillary dissection. Treatment, typically this is either wide local excision or mastectomy. There are many sub types of both of these that fall outside of the MRCS. Some key rules to bear in mind. Whatever operation is contemplated the final cosmetic outcome does have a bearing. A woman with small breasts and a large tumour will tend to fare better with mastectomy, even if clear pathological and clinical margins can be obtained. Conversely a women with larger breasts may be able to undergo breast conserving surgery even with a relatively large primary lesion (NB tumours >4cm used to attract recommendation for mastectomy). For screen detected and impalpable tumour image guidance will be necessary. Reconstruction is always an option following any resectional procedure. However, its exact type must be tailored to age and co-morbidities of the patient. The main operations in common use include latissimus dorsi myocutaneous flap and sub pectoral implants. Women wishing to avoid a prosthesis may be offered TRAM or DIEP flaps. Surgical options Mastectomy vs Wide local excision Mastectomy Wide Local Excision Multifocal tumour Solitary lesion Central tumour Peripheral tumour Large lesion in small breast Small lesion in large breast DCIS >4cm DCIS <4cm Patient Choice Patient choice Central lesions may be managed using breast conserving surgery where an acceptable cosmetic result may be obtained, this is rarely the case in small breasts Whatever surgical option is chosen the aim should be to have a local recurrence rate of 5% or less at 5 years [1]. Nottingham Prognostic Index The Nottingham Prognostic Index can be used to give an indication of survival. In this system the tumour size is weighted less heavily than other major prognostic parameters. Calculation of NPI Tumour Size x 0.2 + Lymph node score(From table below)+Grade score(From table below). Score Lymph nodes involved Grade 1 0 1 2 1-3 2 3 >3 3 Prognosis Score Percentage 5 year survival 2.0 to 2.4 93% 2.5 to 3.4 85% 3.5 to 5.4 70% >5.4 50% This data was originally published in 1992. It should be emphasised that other factors such as vascular invasion and receptor status also impact on survival and are not included in this data and account for varying prognoses often cited in the literature. References For guidance on how breast cancer is managed in the United Kingdom visit the Association of Breast Surgery website (www.https://associationofbreastsurgery.org.uk/).

Answer 1033

Superficial peroneal nerve Supplies Lateral compartment of leg: peroneus longus, peroneus brevis (action: eversion and plantar flexion) Sensation over dorsum of the foot (except the first web space, which is innervated by the deep peroneal nerve) Path Passes between peroneus longus and peroneus brevis along the length of the proximal one third of the fibula 10-12 cm above the tip of the lateral malleolus, the superficial peroneal nerve pierces the fascia 6-7 cm distal to the fibula, the superficial peroneal nerve bifurcates into intermediate and medial dorsal cutaneous nerves

Answer 1034

T3 binds to a receptor on chromatin to induce protein synthesis. Thyroid hormones Hormones of the thyroid gland Triiodothyronine T3 Major hormone active in target cells Thyroxine T4 Most prevalent form in plasma, less biologically active than T3 Calcitonin Lowers plasma calcium Synthesis and secretion of thyroid hormones Thyroid actively concentrates iodide to twenty five times the plasma concentration. Iodide is oxidised by peroxidase in the follicular cells to atomic iodine which then iodinates tyrosine residues contained in thyroglobulin. Iodinated tyrosine residues in thyroglobulin undergo coupling to either T3 or T4. Process is stimulated by TSH, which stimulates secretion of thyroid hormones. The normal thyroid has approximately 3 month reserves of thyroid hormones. LATS and Graves disease In Graves disease, patients develop IgG antibodies to the TSH receptors on the thyroid gland. This results in chronic and long term stimulation of the gland with release of thyroid hormones. The typically situation is raised thyroid hormones and low TSH. Thyroid receptor autoantibodies should be checked in individuals presenting with hyperthyroidism as they are present in up to 85% cases.

Answer 1035

The oesophagus passes into the abdomen at T10. Oesophagus - 25cm long Starts at C6 vertebra, pierces diaphragm at T10 and ends at T11 Squamous epithelium Constrictions of the oesophagus Structure Distance from incisors Cricoid cartilage 15cm Arch of the Aorta 22.5cm Left principal bronchus 27cm Diaphragmatic hiatus 40cm Relations Anteriorly Trachea to T4 Recurrent laryngeal nerve Left bronchus, Left atrium Diaphragm Posteriorly Thoracic duct to left at T5 Hemiazygos to the left T8 Descending aorta First 2 intercostal branches of aorta Left Thoracic duct Left subclavian artery Right Azygos vein Arterial, venous and lymphatic drainage of the oesophagus Artery Vein Lymphatics Muscularis externa Upper third Inferior thyroid Inferior thyroid Deep cervical Striated muscle Mid third Aortic branches Azygos branches Mediastinal Smooth & striated muscle Lower third Left gastric Left gastric Gastric Smooth muscle Nerve supply Upper half is supplied by recurrent laryngeal nerve Lower half by oesophageal plexus (vagus) Histology Mucosa :Non-keratinized stratified squamous epithelium Submucosa: glandular tissue Muscularis externa (muscularis): composition varies. See table Adventitia

Answer 1036

The most likely explanation for this event is a blocked catheter. This may be the result of blood clot from the ureteric anastomosis. Bladder irrigation will usually resolve the problem. Complications following renal transplant Renal transplantation is widely practised. The commonest technical related complications are related to the ureteric anastomosis. The warm ischaemic time is also of considerable importance and graft survival is directly related to this. Long warm ischaemic times increase the risk of acute tubular necrosis which may occur in all types of renal transplanation and provided other insults are minimised, will usually recover. Organ rejection may occur at any phase following the transplantation process. Immunological complications Types of organ rejection Hyperacute. This occurs immediately through presence of pre formed antibody (such as ABO incompatibility). Acute. Occurs during the first 6 months and is usually T cell mediated. Usually tissue infiltrates and vascular lesions. Chronic. Occurs after the first 6 months. Vascular changes predominate. Hyperacute Renal transplants are most susceptible to this process. Risk factors include major HLA mismatch and ABO incompatibility. The rejection occurs almost immediately and the macroscopic features may become manifest following completion of the vascular anastomosis and removal of clamps. The kidney becomes mottled, dusky and the vessels will thrombose. The only treatment is removal of the graft, if left in situ it will result in abscess formation. Acute All organs may undergo acute rejection. Mononuclear cell infiltrates predominate. All types of transplanted organ are susceptible and it may occur in up to 50% cases. Most cases can be managed medically. Chronic Again all transplants with HLA mismatch may suffer this fate. Previous acute rejections and other immunosensitising events all increase the risk. Vascular changes are most prominent with myointimal proliferation leading to organ ischaemia. Organ specific changes are also seen such as loss of acinar cells in pancreas transplants and rapidly progressive coronary artery disease in cardiac transplants. Technical complications Complication Presenting features Treatment Renal artery thrombosis Sudden complete loss of urine output Immediate surgery may salvage the graft, delays beyond 30 minutes are associated with a high rate of graft loss Renal artery stenosis Uncontrolled hypertension, allograft dysfunction and oedema Angioplasty is the treatment of choice Renal vein thrombosis Pain and swelling over the graft site, haematuria and oliguria The graft is usually lost Urine leaks Diminished urine output, rising creatinine, fever and abdominal pain USS shows perigraft collection, necrosis of ureter tip is the commonest cause and the anastomosis may need revision Lymphocele Common complication (occurs in 15%), may present as a mass, if large may compress ureter May be drained with percutaneous technique and sclerotherapy, or intraperitoneal drainage

Answer 1037

The first priority in this patient is to stabilise the myocardium with intravenous calcium gluconate. Management of hyperkalaemia Untreated hyperkalaemia may cause life-threatening arrhythmias. Precipitating factors should be addressed (e.g. acute renal failure) and aggravating drugs stopped (e.g. ACE inhibitors). Management may be categorised by the aims of treatment Stabilisation of the cardiac membrane Intravenous calcium gluconate Short-term shift in potassium from extracellular to intracellular fluid compartment Combined insulin/dextrose infusion Nebulised salbutamol Removal of potassium from the body Calcium resonium (orally or enema) Loop diuretics Dialysis

Answer 1038

Endocrine parameters reduced in stress response: Insulin Testosterone Oestrogen Insulin is often released in decreased quantities following surgery. Stress response: Endocrine and metabolic changes - Surgery precipitates hormonal and metabolic changes causing the stress response. Stress response is associated with: substrate mobilization, muscle protein loss, sodium and water retention, suppression of anabolic hormone secretion, activation of the sympathetic nervous system, immunological and haematological changes. The hypothalamic-pituitary axis and the sympathetic nervous systems are activated and there is a failure of the normal feedback mechanisms of control of hormone secretion. A summary of the hormonal changes associated with the stress response: Increased Decreased No Change Growth hormone Insulin Thyroid stimulating hormone Cortisol Testosterone Luteinizing hormone Renin Oestrogen Follicle stimulating hormone Adrenocorticotrophic hormone (ACTH) Aldosterone Prolactin Antidiuretic hormone Glucagon Sympathetic nervous system Stimulates catecholamine release Causes tachycardia and hypertension Pituitary gland ACTH and growth hormone (GH) is stimulated by hypothalamic releasing factors, corticotrophin releasing factor (CRF) and somatotrophin (or growth hormone releasing factor) Perioperative increased prolactin secretion occurs by release of inhibitory control Secretion of thyroid stimulating hormone (TSH), luteinizing hormone (LH) and follicle stimulating hormone (FSH) does not change significantly ACTH stimulates cortisol production within a few minutes of the start of surgery. More ACTH is produced than needed to produce a maximum adrenocortical response. Cortisol Significant increases within 4-6 hours of surgery (>1000 nmol litre-1). The usual negative feedback mechanism fails and concentrations of ACTH and cortisol remain persistently increased. The magnitude and duration of the increase correlate with the severity of stress and the response is not abolished by the administration of corticosteroids. The metabolic effects of cortisol are enhanced: Skeletal muscle protein breakdown to provide gluconeogenic precursors and amino acids for protein synthesis in the liver Stimulation of lipolysis 'Anti-insulin effect' Mineralocorticoid effects Anti-inflammatory effects Growth hormone Increased secretion after surgery has a minor role Most important for preventing muscle protein breakdown and promote tissue repair by insulin growth factors Alpha Endorphin Increased Antidiuretic hormone An important vasopressor and enhances haemostasis Renin is released causing the conversion of angiotensinogen to angiotensin I Angiotensin II formed by ACE on angiotensin 1, which causes the secretion of aldosterone from the adrenal cortex. This increases sodium reabsorption at the distal convoluted tubule Insulin Release inhibited by stress Occurs via the inhibition of the beta cells in the pancreas by the α2-adrenergic inhibitory effects of catecholamines Insulin resistance by target cells occurs later The perioperative period is characterized by a state of functional insulin deficiency Thyroxine (T4) and tri-iodothyronine (T3) Circulating concentrations are inversely correlated with sympathetic activity and after surgery there is a reduction in thyroid hormone production, which normalises over a few days. Metabolic effect of endocrine response Carbohydrate metabolism Hyperglycaemia is a main feature of the metabolic response to surgery Due to increase in glucose production and a reduction in glucose utilization Catecholamines and cortisol promote glycogenolysis and gluconeogenesis Initial failure of insulin secretion followed by insulin resistance affects the normal responses The proportion of the hyperglycaemic response reflects the severity of surgery Hyperglycaemia impairs wound healing and increase infection rates Protein metabolism Initially there is inhibition of protein anabolism, followed later, if the stress response is severe, by enhanced catabolism The amount of protein degradation is influenced by the type of surgery and also by the nutritional status of the patient Mainly skeletal muscle protein is affected The amino acids released form acute phase proteins (fibrinogen, C reactive protein, complement proteins, a2-macroglobulin, amyloid A and ceruloplasmin) and are used for gluconeogenesis Nutritional support has little effect on preventing catabolism Lipid metabolism Increased catecholamine, cortisol and glucagon secretion, and insulin deficiency, promotes lipolysis and ketone body production. Salt and water metabolism ADH causes water retention, concentrated urine, and potassium loss and may continue for 3 to 5 days after surgery Renin causes sodium and water retention Cytokines Glycoproteins Interleukins (IL) 1 to 17, interferons, and tumour necrosis factor Synthesized by activated macrophages, fibroblasts, endothelial and glial cells in response to tissue injury from surgery or trauma IL-6 main cytokine associated with surgery. Peak 12 to 24 h after surgery and increase by the degree of tissue damage Other effects of cytokines include fever, granulocytosis, haemostasis, tissue damage limitation and promotion of healing. Modifying the response Opioids suppress hypothalamic and pituitary hormone secretion At high doses the hormonal response to pelvic and abdominal surgery is abolished. However, such doses prolong recovery and increase the need for postoperative ventilatory support Spinal anaesthesia can reduce the glucose, ACTH, cortisol, GH and epinephrine changes, although cytokine responses are unaltered Cytokine release is reduced in less invasive surgery Nutrition prevents the adverse effects of the stress response. Enteral feeding improves recovery Growth hormone and anabolic steroids may improve outcome Normothermia decreases the metabolic response References Vasiliki Manou-Stathopoulou et al. Redefining the perioperative stress response: a narrative review. Br J Anaesth. 2019 Nov;123(5):570-583. Deborah Burton, Grainne Nicholson, and George Hall Endocrine and metabolic response to surgery . Contin Educ Anaesth Crit Care Pain (2004) 4(5): 144-147 doi:10.1093/bjaceaccp/mkh040

Answer 1039

Wide local excision and excision biopsy are different procedures. The imaging and biopsy results are not concordant. At this stage an excision biopsy is the safest option. CT scanning is seldom helpful in breast surgery. Breast cancer management - Surgery is performed in most patients suffering from breast cancer. Chemotherapy may be used to downstage tumours and allow breast conserving surgery. Hormonal therapy may also be used for the same purposes. Radiotherapy is given to most patients who have undergone breast conserving surgery (some older patients receiving hormone treatment and who have small low grade tumours may safely avoid DXT. Therapeutic mammoplasty is an option for some patients but requires symmetrizing surgery in most cases. Patients who have undergone mastectomy may be offered a reconstructive procedure either in conjunction with their primary resection or as a staged procedure at a later date. Surgical options Mastectomy vs Wide local excision Mastectomy Wide Local Excision Multifocal tumour Solitary lesion Central tumour Peripheral tumour Large lesion in small breast Small lesion in large breast DCIS >4cm DCIS <4cm Patient Choice Patient choice Central lesions may be managed using breast conserving surgery, where an acceptable cosmetic result may be obtained, this is rarely the case in small breasts Axillary disease As a minimum, all patients with invasive breast cancer should have their axilla staged. In those who do not have overt evidence of axillary nodal involvement this can be undertaken using sentinel lymph node biopsy. Patients with a positive sentinel lymph node biopsy or who have imaging and cytological or histological evidence of axillary nodal metastasis should undergo axillary node clearance or axillary irradiation. Axillary node clearance is associated with the development of lymphoedema, increased risk of cellulitis and frozen shoulder.

Answer 1040

This child is at risk of developmental dysplasia of the hip (up to 20% will have DDH), so should have the hip joints scanned to exclude this. Paediatric orthopaedics Diagnosis Mode of presentation Treatment Radiology Developmental dysplasia of the hip Usually diagnosed in infancy by screening tests. May be bilateral, when disease is unilateral there may be leg length inequality. As disease progresses child may limp and then early onset arthritis. More common in extended breech babies. Splints and harnesses or traction. In later years osteotomy and hip realignment procedures may be needed. In arthritis a joint replacement may be needed. However, this is best deferred if possible as it will almost certainly require revision Initially no obvious change on plain films and USS gives best resolution until 3 months of age. On plain films Shentons line should form a smooth arc Perthes Disease Hip pain (may be referred to the knee) usually occurring between 5 and 12 years of age. Bilateral disease in 20%. Remove pressure from joint to allow normal development. Physiotherapy. Usually self-limiting if diagnosed and treated promptly. X-rays will show flattened femoral head. Eventually in untreated cases the femoral head will fragment. Slipped upper femoral epiphysis Typically seen in obese male adolescents. Pain is often referred to the knee. Limitation to internal rotation is usually seen. Knee pain is usually present 2 months prior to hip slipping. Bilateral in 20%. Bed rest and non-weight bearing. Aim to avoid avascular necrosis. If severe slippage or risk of it occurring then percutaneous pinning of the hip may be required. X-rays will show the femoral head displaced and falling inferolaterally (like a melting ice cream cone) The Southwick angle gives indication of disease severity

Answer 1041

Organisms causing post splenectomy sepsis: Streptococcus pneumoniae Haemophilus influenzae Meningococci Encapsulated organisms carry the greatest pathogenic risk following splenectomy. The effects of sepsis following splenectomy are variable. This may be the result of small isolated fragments of splenic tissue that retain some function following splenectomy. These may implant spontaneously following splenic rupture (in trauma) or be surgically implanted at the time of splenectomy. Post splenectomy sepsis Hyposplenism may complicate certain medical conditions where splenic atrophy occurs or may be the result of medical intervention such as splenic artery embolization and splenectomy for trauma. Diagnosis of hyposplenism is difficult and whilst there may be peripheral markers of the splenectomised state (e.g. Howell Jolly bodies) these are neither 100% sensitive or specific. The most sensitive test is a radionucleotide labeled red cell scan. Hyposplenism, by whatever mechanism it occurs dramatically increases the risk of post splenectomy sepsis, particularly with encapsulated organisms. Since these organisms may be opsonised, but this then goes undetected at an immunological level due to loss of the spleen. For this reason individuals are recommended to be vaccinated and have antibiotic prophylaxis. Key recommendations All those with hyposplenism or may become so (such as prior to an elective splenectomy) should receive pneumococcal, haemophilus type b and meningococcal type C vaccines. These should be administered 2 weeks prior to splenectomy or two weeks following splenectomy. The vaccine schedule for meningococcal disease essentially consists of a dose of Men C and Hib at 2 weeks and then a dose of the MenACWY vaccine one month later. Those aged under 2 may require a booster at 2 years. A dose of pneumococcal polyvalent polysaccharide vaccine (PPV) is given at two weeks. A conjugated vaccine (PCV) is offered to young children. The PCV is more immunogenic but covers fewer serotypes. Boosting PPV is either guided by serological measurements (where available) or by routine boosting doses at 5 yearly intervals. Annual influenza vaccination is recommended in all cases Antibiotic prophylaxis is offered to all. The risk of post splenectomy sepsis is greatest immediately following splenectomy and in those aged less than 16 years or greater than 50 years. Individuals with a poor response to pneumococcal vaccination are another high risk group. High risk individuals should be counselled to take penicillin or macrolide prophylaxis. Those at low risk may choose to discontinue therapy. All patients should be advised about taking antibiotics early in the case of intercurrent infections. Asplenic individuals traveling to malaria endemic areas are at high risk and should have both pharmacological and mechanical protection. Dosing Penicillin V 500mg BD or amoxicillin 250mg BD References Davies J et al. Review of guidelines for the prevention and treatment of infection in patients with an absent or dysfunctional spleen: Prepared on behalf of the British Committee for Standards in Haematology by a Working Party of the Haemato-Oncology Task Force. British Journal of Haematology 2011 (155): 308317.

Answer 1042

A below knee amputation is the best option here. The foot is non salvageable. However, she may ambulate with a prosthesis. Amputations Amputations are indicated when the affected limb is one of the following: Dead non viable Deadly where it is posing a major threat to life Dead useless where it is viable but a prosthesis would be preferable Orthopaedic surgery Amputation is often undertaken as an option of last resort e.g. Limb salvage has failed and the limb is so non functional that mobility needs would be best met with prosthesis. Chronic fracture non union or significant limb shortening following trauma would fit into this category. Occasionally following major trauma a primary amputation is preferable. This would be the case in an open fracture with major distal neurovascular compromise and other more life threatening injuries are present. Vascular surgery The first two categories are the most prevalent. Diabetic foot sepsis is often a major cause of sepsis which can spread rapidly in the presence of established peripheral vascular disease. As a general rule the main issue in vascular surgery is to optimise vascular inflow prior to surgery. The more distal the planned amputation is to be, the more important this rule becomes. In other situations there has been something such as an embolic event that has not been revascularised in time. In this case the limb shows fixed mottling and an amputation will be needed. Types of amputations As the vast majority of commonly performed amputations affect the lower limbs these will be covered here. The main categories of amputations are: Pelvic disarticulation (hindquarter) Above knee amputation Gritti Stokes (through knee amputation) Below knee amputation (using either Skew or Burgess flaps) Syme's amputation (through ankle) Amputations of mid foot and digits Choosing a level of amputation depends on: The disease process being treated Desired functional outcome Co-morbidities of the patient Above knee amputations Quick to perform Heal reliably Patients regain their general health quickly For this benefit, a functional price has to be paid and many patients over the age of 70 will never walk on an above knee prosthesis. Above knee amputations use equal anterior-posterior flaps Below knee amputations Technically more challenging to perform Heal less reliably than their above knee counterparts. However, many more patients are able to walk using a below knee prosthesis. In below knee amputations the two main flaps are Skew flaps or the Burgess long posterior flap. Skew flaps result in a less bulky limb that is easier to attach a prosthesis to. It is worth remembering that whilst it may be technically feasible to offer a below knee amputation there may be circumstances where an above knee option is preferable. For example, in fixed flexion deformities of the lower limb, little functional benefit would be gained from below knee amputation surgery.

Answer 1043

A-Milrinone Circulatory support of the critically ill Circulatory support Impaired tissue oxygenation may occur as a result of circulatory shock. Shock is considered further under its own topic heading. Patients requiring circulatory support require haemodynamic monitoring. At its simplest level this may simply be in the form of regular urine output measurements and blood pressure monitoring. In addition ECG monitoring will allow the identification of cardiac arrhythmias. Pulse oximeter measurements will allow quick estimation haemoglobin oxygen saturation in arterial blood. Invasive arterial blood pressure monitoring is undertaken by the use of an indwelling arterial line. Most arterial sites can be used although the radial artery is the commonest. It is important not to cannulate end arteries. The arterial trace can be tracked to ventilation phases and those patients whose systolic pressure varies with changes in intrathoracic pressure may benefit from further intravenous fluids. Central venous pressure is measured using a CVP line that is usually sited in the superior vena cava via the internal jugular route. The CVP will demonstrate right atrial filling pressure and volume status. When adequate intra vascular volume is present a fluid challenge will typically cause a prolonged rise in CVP (usually greater than 6-8mmHg). To monitor the cardiac output a Swan-Ganz catheter is traditionally inserted (other devices may be used and are less invasive). Inflation of the distal balloon will provide the pulmonary artery occlusion pressure and the pressure distal to the balloon will equate to the left atrial pressure. This gives a measure of left ventricular preload. Because the Swan-Ganz catheter can measure several variables it can be used to calculate: Stroke volume Systemic vascular resistance Pulmonary artery resistance Oxygen delivery (and consumption) Inotropes In patients with an adequate circulating volume but on-going circulatory compromise a vasoactive drug may be considered. These should usually be administered via the central venous route. Commonly used inotropes include: Agent Mode of action Effect Noradrenaline α agonist Vasopressor action, minimal effect on cardiac output Adrenaline α and β receptor agonist Increases cardiac output and peripheral vascular resistance Dopamine β1 agonist Increases contractility and rate Dobutamine β1 and β2 agonist Increases cardiac output and decreases SVR Milrinone Phosphodiesterase inhibitor Elevation of cAMP levels improves muscular contractility, short half life and acts as vasodilator

Answer 1044

Pyoderma gangrenosum is associated with inflammatory bowel disease (this patient had a stoma for crohns!). It is commonly found on lower limbs and described as being painful, the size of an insect bite and growing. It looks like a margherita pizza (with a red base and yellow topping!) Treatment involves steroids. It would be rare for a poorly fitting appliance to cause a deep painful ulcer. Benign skin diseases Seborrhoeic keratosis Most commonly arise in patients over the age of 50 years, often idiopathic Equal sex incidence and prevalence Usually multiple lesions over face and trunk Flat, raised, filiform and pedunculated subtypes are recognised Variable colours and surface may have greasy scale overlying it Treatment options consist of leaving alone or simple shave excision Melanocytic naevi Congenital melanocytic naevi Typically appear at, or soon after, birth Usually greater than 1cm diameter Increased risk of malignant transformation (increased risk greatest for large lesions) Junctional melanocytic naevi Circular macules May have heterogeneous colour even within same lesion Most naevi of the palms, soles and mucous membranes are of this type Compound naevi Domed pigmented nodules up to 1cm in diameter Arise from junctional naevi, usually have uniform colour and are smooth Spitz naevus Usually develop over a few months in children May be pink or red in colour, most common on face and legs May grow up to 1cm and growth can be rapid, this usually results in excision Atypical naevus syndrome Atypical melanocytic naevi that may be autosomally dominantly inherited Some individuals are at increased risk of melanoma (usually have mutations of CDKN2A gene) Many people with atypical naevus syndrome AND a parent sibling with melanoma will develop melanoma Epidermoid cysts Common and affect face and trunk They have a central punctum, they may contain small quantities of sebum The cyst lining is either normal epidermis (epidermoid cyst) or outer root sheath of hair follicle (pilar cyst) Dermatofibroma Solitary dermal nodules Usually affect extremities of young adults Lesions feel larger than they appear visually Histologically they consist of proliferating fibroblasts merging with sparsely cellular dermal tissues Painful skin lesions Eccrine spiradenoma Neuroma Glomus tumour Leiomyoma Angiolipoma Neurofibroma (rarely painful) and dermatofibroma (rarely painful)

Answer 1045

Cystine stones are associated with an inherited metabolic disorder. Renal stones Type of stones Features Percentage of all calculi Calcium oxalate Hypercalciuria is a major risk factor (various causes) Hyperoxaluria may also increase risk Hypocitraturia increases risk because citrate forms complexes with calcium making it more soluble Stones are radio-opaque (though less than calcium phosphate stones) Hyperuricosuria may cause uric acid stones to which calcium oxalate binds 85% Cystine Inherited recessive disorder of transmembrane cystine transport leading to decreased absorption of cystine from intestine and renal tubule Multiple stones may form Relatively radiodense because they contain sulphur 1% Uric acid Uric acid is a product of purine metabolism May precipitate when urinary pH low May be caused by diseases with extensive tissue breakdown e.g. malignancy More common in children with inborn errors of metabolism Radiolucent 5-10% Calcium phosphate May occur in renal tubular acidosis, high urinary pH increases supersaturation of urine with calcium and phosphate Renal tubular acidosis types 1 and 3 increase risk of stone formation (types 2 and 4 do not) Radio-dense stones (composition similar to bone) 10% Struvite Stones formed from magnesium, ammonium and phosphate Occur as a result of urease producing bacteria (and are thus associated with chronic infections) Under the alkaline conditions produced, the crystals can precipitate Slightly radio-opaque 2-20% Effect of urinary pH on stone formation Urine pH will show individual variation (from pH 5-7). Post prandially the pH falls as purine metabolism will produce uric acid. Then the urine becomes more alkaline (alkaline tide). When the stone is not available for analysis the pH of urine may help to determine which stone was present. Stone type Urine acidity Mean urine pH Calcium phosphate Normal- alkaline >5.5 Calcium oxalate Variable 6 Uric acid Acid 5.5 Struvite Alkaline >7.2 Cystine Normal 6.5

Answer 1046

The decrease in blood pressure will be sensed by the juxtaglomerular cells in the kidney. This will cause renin secretion. Shock - Shock occurs when there is insufficient tissue perfusion. The pathophysiology of shock is an important surgical topic and may be divided into the following aetiological groups: Septic Haemorrhagic Neurogenic Cardiogenic Anaphylactic Septic shock Septic shock is a major problem and those patients with severe sepsis have a mortality rate in excess of 40%. In those who are admitted to intensive care mortality ranges from 6% with no organ failure to 65% in those with 4 organ failure. Sepsis is defined as an infection that triggers a particular Systemic Inflammatory Response Syndrome (SIRS). In 2016, the European Society of Intensive Care Medicine and the Society of Critical Care Medicine (SCCM) created a task force that proposed Sepsis-3, a new definition for sepsis. The new definition excluded the establishment of SIRS criteria to define sepsis and made it more nonspecific as any life-threatening organ dysfunction caused by the dysregulated host response to infection. The task force claimed that sequential organ failure assessment (SOFA) has a better predictive validity for sepsis than SIRS criteria. It has better prognostic accuracy and the ability to predict in-hospital mortality. To reduce the complexity of calculating the SOFA, they introduced q SOFA Q SOFA 3 component assessment system with: Systolic blood pressure below 100 mm Hg Highest respiratory rate exceeding 21 Lowest Glasgow coma score is under 15 Although the validity of q SOFA is limited in an ICU setting, it has consistently outperformed SIRS criteria in predicting organ dysfunction in a non-ICU and ER setting. The use of vasopressors, mechanical ventilation, and aggressive therapeutic interventions in ICU limit the efficacy of q SOFA. During the septic process there is marked activation of the immune system with extensive cytokine release. This may be coupled with or triggered by systemic circulation of bacterial toxins. These all cause endothelial cell damage and neutrophil adhesion. The overall hallmarks are thus those of excessive inflammation, coagulation and fibrinolytic suppression. The main management issues with severe infections resulting in organ dysfunction are as follows: Prompt administration of antibiotics to cover all likely pathogens coupled with a rigorous search for the source of infection. Haemodynamic stabilisation. Many patients are hypovolaemic and require aggressive fluid administration. Aim for CVP 8-12 cm H2O, MAP >65mmHg. Modulation of the septic response. This includes manoeuvres to counteract the changes and includes measures such as tight glycaemic control. The routine use of steroids is not advised. In surgical patients, the main groups with septic shock include those with anastomotic leaks, abscesses and extensive superficial infections such as necrotising fasciitis. When performing surgery the aim should be to undertake the minimum necessary to restore physiology. These patients do not fare well with prolonged surgery. Definitive surgery can be more safely undertaken when physiology is restored and clotting in particular has been normalised. Haemorrhagic shock The average adult blood volume comprises 7% of body weight. Thus in the 70 Kg adult this will equate to 5 litres. This changes in children (8-9% body weight) and is slightly lower in the elderly. The table below outlines the 4 major classes of haemorrhagic shock and their associated physiological sequelae: Parameter Class I Class II Class III Class IV Blood loss ml <750ml 750-1500ml 1500-2000ml >2000ml Blood loss % <15% 15-30% 30-40% >40% Pulse rate <100 >100 >120 >140 Blood pressure Normal Normal Decreased Decreased Respiratory rate 14-20 20-30 30-40 >35 Urine output >30ml 20-30ml 5-15ml <5ml Symptoms Normal Anxious Confused Lethargic Decreasing blood pressure during haemorrhagic shock causes organ hypoperfusion and relative myocardial ischaemia. The cardiac index gives a numerical value for tissue oxygen delivery and is given by the equation: Cardiac index= Cardiac output/ body surface area. Where Hb is haemoglobin concentration in blood and SaO2 the saturation and PaO2 the partial pressure of oxygen. Detailed knowledge of this equation is required for the MRCS Viva but not for part A, although you should understand the principle. In patients suffering from trauma the most likely cause of shock is haemorrhage. However, the following may also be the cause or occur concomitantly: Tension pneumothorax Spinal cord injury Myocardial contusion Cardiac tamponade When assessing trauma patients it is worth remembering that in order to generate a palpable femoral pulse an arterial pressure of >65mmHg is required. Once bleeding is controlled and circulating volume normalised the levels of transfusion should be to maintain a Hb of 7-8 in those with no risk factors for tissue hypoxia and Hb 10 for those who have such risk factors. Neurogenic shock This occurs most often following a spinal cord transection, usually at a high level. There is resultant interruption of the autonomic nervous system. The result is either decreased sympathetic tone or increased parasympathetic tone, the effect of which is a decrease in peripheral vascular resistance mediated by marked vasodilation. This results in decreased preload and thus decreased cardiac output (Starlings law). There is decreased peripheral tissue perfusion and shock is thus produced. In contrast with many other types of shock peripheral vasoconstrictors are used to return vascular tone to normal. Cardiogenic shock In medical patients the main cause is ischaemic heart disease. In the traumatic setting direct myocardial trauma or contusion is more likely. Evidence of ECG changes and overlying sternal fractures or contusions should raise the suspicion of injury. Treatment is largely supportive and transthoracic echocardiography should be used to determine evidence of pericardial fluid or direct myocardial injury. The measurement of troponin levels in trauma patients may be undertaken but they are less useful in delineating the extent of myocardial trauma than following MI. When cardiac injury is of a blunt nature and is associated with cardiogenic shock the right side of the heart is the most likely site of injury with chamber and or valve rupture. These patients require surgery to repair these defects and will require cardiopulmonary bypass to achieve this. Some may require intra aortic balloon pump as a bridge to surgery. Anaphylactic shock Anaphylaxis may be defined as a severe, life-threatening, generalised or systemic hypersensitivity reaction. Anaphylaxis is one of the few times when you would not have time to look up the dose of a medication. The Resuscitation Council guidelines on anaphylaxis have recently been updated. Adrenaline is by far the most important drug in anaphylaxis and should be given as soon as possible. The recommended doses for adrenaline, hydrocortisone and chlorpheniramine (if one wishes to use them) are as follows: Adrenaline Hydrocortisone Chlorpheniramine < 6 months 150 mcg (0.15ml 1 in 1,000) 25 mg 250 mcg/kg 6 months - 6 years 150 mcg (0.15ml 1 in 1,000) 50 mg 2.5 mg 6-12 years 300 mcg (0.3ml 1 in 1,000) 100 mg 5 mg Adult and child 12 years 500 mcg (0.5ml 1 in 1,000) 200 mg 10 mg Adrenaline can be repeated every 5 minutes if necessary. The best site for IM injection is the anterolateral aspect of the middle third of the thigh. Common identified causes of anaphylaxis food (e.g. Nuts) - the most common cause in children drugs venom (e.g. Wasp sting)

Answer 1047

The most likely diagnosis is a carotid body tumour and it is likely to be of the hyperplastic type. Carotid body tumour These are rare tumours. However, they typically account for around 60% of head and neck paraganglionomas. They are usually tumours of middle age. Around 5% are bilateral and around 5% are malignant. They are rarely found as part of the MEN II or neurofibromatosis type I disease complexes. They typically present as an asymptomatic neck mass in the anterior triangle of the neck. They are typically slow growing lesions. Types of carotid body tumour Sporadic - Accounts for 85% of cases Familial - Seen in around 10% of cases and usually in younger patients Hyperplastic - Seen in those at high altitude or in those with COPD Imaging They are readily imaged using duplex ultrasonography. CT angiography is sometimes helpful. Treatment Typically this comprises surgical resection. This is preceded by embolization in selected cases.

Answer 1048

HCC may complicate cirrhosis. AFP is often raised in HCC. Hepatocellular carcinoma Hepatocellular carcinoma is the second leading cause of cancer deaths globally. Up to 750,000 cases are reported annually. Unfortunately the incidence approximates to the death rate so there are few long term survivors[1]. The disease occurs most commonly in those with chronic hepatitis and established liver cirrhosis. Therefore, these individuals should be closely screened for the development of HCC with serum AFP and liver USS every 6-12 months. Rising AFP and liver USS showing a nodule greater than 1cm in diameter makes HCC much more likely and such patients should then undergo MRI scanning. The presence of adenomas in an otherwise healthy liver is a recognised risk factor for HCC [2, 3] and many surgeons will remove liver adenomas for this reason[4]. Diagnosis The aim is to avoid unnecessary percutaneous biopsy. Radiologically on CT the classical feature is a suspicious lesion which is highlighted during the arterial phase with washout during the venous phase, this reflects the hypervascularity of the lesions.The risk of tumour seeding as a result of a liver biopsy is 2.7% with a median time interval between biopsy and seeding of 17 months[5]. Barcelona Clinic Liver Classification There are many classification systems for addressing the management and prognosis, the BCLC system has the convenience of categorising disease extent with treatment and prognostic outcomes. In determining the ideal treatment modality for HCC the key points are not just disease extent, but also the functional state of the liver and patient. Stage Features Treatment Prognosis-5 yr survival Stage 0 Child-Pugh A Single lesion (less than 2cm) Normal portal pressures Resection 40-70% Stage A Single nodule greater than 3cm or multiple nodules (no more than 3) Child Pugh A/ B If associated disease then radiofrequency ablation If no associated disease then transplantation May be up to 70% in some Stage B Multiple nodules Child Pugh A/B Trans arterial chemo-embolisation (usually with doxorubicin) 26% at 3 years Stage C Advanced tumours Invasion of portal vein Child Pugh A/B Sorafenib Usually survive 10.7 months Stage D Child Pugh stage C Advanced tumours Best supportive care Less than 6 months survival [6] In selected patients the best outcomes are achieved with surgical resection, or transplantation where surgical resection is precluded. Anatomical resections with minimum 2cm margins provide the best outcomes. At the present time there is no evidence to recommend treatment with adjuvant chemotherapy[6]. Sorafenib This is an oral multi tyrosine kinase inhibitor. It is the only drug that has been currently demonstrated to extend survival in individuals with advanced hepatocellular cancer[7]. The improvement in survival is from a median of 7 months to 10 months. References 1. Jemal, A., et al., Global cancer statistics. CA Cancer J Clin, 2011. 61(2): p. 69-90. 2. Leese, T., O. Farges, and H. Bismuth, Liver cell adenomas. A 12-year surgical experience from a specialist hepato-biliary unit. Ann Surg, 1988. 208(5): p. 558-64. 3. Farges, O. and S. Dokmak, Malignant transformation of liver adenoma: an analysis of the literature. Dig Surg, 2010. 27(1): p. 32-8. 4. Ehrl, D., et al., 'Incidentaloma' of the liver: management of a diagnostic and therapeutic dilemma. HPB Surg, 2012. 2012: p. 891787. 5. Silva, M.A., et al., Needle track seeding following biopsy of liver lesions in the diagnosis of hepatocellular cancer: a systematic review and meta-analysis. Gut, 2008. 57(11): p. 1592-6. 6. EASL-EORTC clinical practice guidelines: management of hepatocellular carcinoma. J Hepatol, 2012. 56(4): p. 908-43. 7. Abou-Alfa, G.K., et al., Phase II study of sorafenib in patients with advanced hepatocellular carcinoma. J Clin Oncol, 2006. 24(26): p. 4293-300.

Answer 1049

Decreased SVR is a major feature of sepsis. A hyperdynamic circulation is often present. This is the reason for the use of vasoconstrictors. Pulmonary artery occlusion pressure monitoring The pulmonary artery occlusion pressure is an indirect measure of left atrial pressure, and thus filling pressure of the left heart. The low resistance within the pulmonary venous system allows this useful measurement to be made. The most accurate trace is made by inflating the balloon at the catheter tip and 'floating' it so that it occludes the vessel. If it is not possible to occlude the vessel in this way then the measurement gained will be the pulmonary artery end diastolic pressure. Interpretation of PAOP PAOP mmHg Scenario Normal 8-12 Low <5 Hypovolaemia Low with pulmonary oedema <5 ARDS High >18 Overload When combined with measurements of systemic vascular resistance and cardiac output it is possible to accurately classify patients. Systemic vascular resistance Derived from aortic pressure, right atrial pressure and cardiac output. SVR=80(mean aortic pressure-mean right atrial pressure)/cardiac output

Answer 1050

A flail chest injury should usually be managed by intubation if saturations are 90% or less. Beware of the potential for underlying parenchymal lung injury which may require chest drain insertion. Thoracic trauma Key points related to thoracic trauma Less than 10% of blunt chest trauma and 15-30% of penetrating chest trauma requires operative intervention. The physiologic consequences of thoracic trauma are hypoxia, hypercarbia, and acidosis. Contusion, hematoma, and alveolar collapse, or changes in intrathoracic pressure relationships (e.g., tension pneumothorax and open pneumothorax) cause hypoxia and lead to metabolic acidosis. Hypercarbia causes respiratory acidosis and most often follows inadequate ventilation caused by changes in intrathoracic pressure relationships and depressed level of consciousness. Types of thoracic trauma Tension pneumothorax Often laceration to lung parenchyma with flap Pressure develops in thorax Most common cause is mechanical ventilation in patient with pleural injury Symptoms overlap with cardiac tamponade, hyper-resonant percussion note is more likely in tension pnemothorax Flail chest Chest wall disconnects from thoracic cage Multiple rib fractures (at least two fractures per rib in at least two ribs) Associated with pulmonary contusion Abnormal chest motion Avoid over hydration and fluid overload Pneumothorax Most common cause is lung laceration with air leakage Most traumatic pneumothoraces should have a chest drain Patients with traumatic pneumothorax should never be mechanically ventilated until a chest drain is inserted Haemothorax Most commonly due to laceration of lung, intercostal vessel or internal mammary artery Haemothoraces large enough to appear on CXR are treated with large bore chest drain Surgical exploration is warranted if >1500ml blood drained immediately Cardiac tamponade Beck's triad: elevated venous pressure, reduced arterial pressure, reduced heart sounds Pulsus paradoxus May occur with as little as 100ml blood Pulmonary contusion Most common potentially lethal chest injury Arterial blood gases and pulse oximetry important Early intubation within an hour if significant hypoxia Blunt cardiac injury Usually occurs secondary to chest wall injury ECG may show features of myocardial infarction Sequelae: hypotension, arrhythmias, cardiac wall motion abnormalities Aorta disruption Deceleration injuries Contained haematoma Widened mediastinum Diaphragm disruption Most due to motor vehicle accidents and blunt trauma causing large radial tears (laceration injuries result in small tears) More common on left side Insert gastric tube, may pass into intrathoracic stomach Mediastinal traversing wounds Entrance wound in one hemithorax and exit wound/foreign body in opposite hemithorax Mediastinal haematoma or pleural cap suggests great vessel injury Mortality is 20% References ATLS Manual 10th Edition. ISBN 78-0-9968262-3-5

Answer 1051

The cuboid is located at the lateral aspect of the foot between the calcaneus posteriorly and the 4th and 5th metatarsals distally. Foot- anatomy Arches of the foot The foot is conventionally considered to have two arches. The longitudinal arch is higher on the medial than on the lateral side. The posterior part of the calcaneum forms a posterior pillar to support the arch. The lateral part of this structure passes via the cuboid bone and the lateral two metatarsal bones. The medial part of this structure is more important. The head of the talus marks the summit of this arch, located between the sustentaculum tali and the navicular bone. The anterior pillar of the medial arch is composed of the navicular bone, the three cuneiforms and the medial three metatarsal bones. The transverse arch is situated on the anterior part of the tarsus and the posterior part of the metatarsus. The cuneiforms and metatarsal bases narrow inferiorly, which contributes to the shape of the arch. Intertarsal joints Sub talar joint Formed by the cylindrical facet on the lower surface of the body of the talus and the posterior facet on the upper surface of the calcaneus. The facet on the talus is concave anteroposteriorly, the other is convex. The synovial cavity of this joint does not communicate with any other joint. Talocalcaneonavicular joint The anterior part of the socket is formed by the concave articular surface of the navicular bone, posteriorly by the upper surface of the sustentaculum tali. The talus sits within this socket Calcaneocuboid joint Highest point in the lateral part of the longitudinal arch. The lower aspect of this joint is reinforced by the long plantar and plantar calcaneocuboid ligaments. Transverse tarsal joint The talocalcaneonavicular joint and the calcaneocuboid joint extend across the tarsus in an irregular transverse plane, between the talus and calcaneus behind and the navicular and cuboid bones in front. This plane is termed the transverse tarsal joint. Cuneonavicular joint Formed between the convex anterior surface of the navicular bone and the concave surface of the the posterior ends of the three cuneiforms. Intercuneiform joints Between the three cuneiform bones. Cuneocuboid joint Between the circular facets on the lateral cuneiform bone and the cuboid. This joint contributes to the tarsal part of the transverse arch. A detailed knowledge of the joints is not required for MRCS Part A. However, the contribution they play to the overall structure of the foot should be appreciated Ligaments of the ankle joint and foot Muscles of the foot Muscle Origin Insertion Nerve supply Action Abductor hallucis Medial side of the calcaneus, flexor retinaculum, plantar aponeurosis Medial side of the base of the proximal phalanx Medial plantar nerve Abducts the great toe Flexor digitorum brevis Medial process of the calcaneus, plantar eponeurosis. Via 4 tendons into the middle phalanges of the lateral 4 toes. Medial plantar nerve Flexes all the joints of the lateral 4 toes except for the interphalangeal joint. Abductor digit minimi From the tubercle of the calcaneus and from the plantar aponeurosis Together with flexor digit minimi brevis into the lateral side of the base of the proximal phalanx of the little toe Lateral plantar nerve Abducts the little toe at the metatarsophalangeal joint Flexor hallucis brevis From the medial side of the plantar surface of the cuboid bone, from the adjacent part of the lateral cuneiform bone and from the tendon of tibialis posterior. Into the proximal phalanx of the great toe, the tendon contains a sesamoid bone Medial plantar nerve Flexes the metatarsophalangeal joint of the great toe. Adductor hallucis Arises from two heads. The oblique head arises from the sheath of the peroneus longus tendon, and from the plantar surfaces of the bases of the 2nd, 3rd and 4th metatarsal bones. The transverse head arises from the plantar surface of the lateral 4 metatarsophalangeal joints and from the deep transverse metatarsal ligament. Lateral side of the base of the proximal phalanx of the great toe. Lateral plantar nerve Adducts the great toe towards the second toe. Helps maintain the transverse arch of the foot. Extensor digitorum brevis On the dorsal surface of the foot from the upper surface of the calcaneus and its associated fascia Via four thin tendons which run forward and medially to be inserted into the medial four toes. The lateral three tendons join with hoods of extensor digitorum longus. Deep peroneal Extend the metatarsophalangeal joint of the medial four toes. It is unable to extend the interphalangeal joint without the assistance of the lumbrical muscles. Nerves in the foot Lateral plantar nerve Passes anterolaterally towards the base of the 5th metatarsal between flexor digitorum brevis and flexor accessorius. On the medial aspect of the lateral plantar artery. At the base of the 5th metatarsal it splits into superficial and deep branches. Medial plantar nerve Passes forwards with the medial plantar artery under the cover of the flexor retinaculum to the interval between abductor hallucis and flexor digitorum brevis on the sole of the foot. Plantar arteries Arise under the cover of the flexor retinaculum, midway between the tip of the medial malleolus and the most prominent part of the medial side of the heel. Medial plantar artery. Passes forwards medial to medial plantar nerve in the space between abductor hallucis and flexor digitorum brevis.Ends by uniting with a branch of the 1st plantar metatarsal artery. Lateral plantar artery. Runs obliquely across the sole of the foot. It lies lateral to the lateral plantar nerve. At the base of the 5th metatarsal bone it arches medially across the foot on the metatarsals Dorsalis pedis artery This vessel is a direct continuation of the anterior tibial artery. It commences on the front of the ankle joint and runs to the proximal end of the first metatarsal space. Here is gives off the arcuate artery and continues forwards as the first dorsal metatarsal artery. It is accompanied by two veins throughout its length. It is crossed by the extensor hallucis brevis

Answer 1052

The vertebral bodies lie outside of the mediastinum, as do the lungs. Mediastinum Region between the pulmonary cavities. It is covered by the mediastinal pleura. It does not contain the lungs. It extends from the thoracic inlet superiorly to the diaphragm inferiorly. Mediastinal regions Superior mediastinum (between manubriosternal angle and T4/5) Middle mediastinum Posterior mediastinum Anterior mediastinum Region Contents Superior mediastinum Superior vena cava Brachiocephalic veins Arch of aorta Thoracic duct Trachea Oesophagus Thymus Vagus nerve Left recurrent laryngeal nerve Phrenic nerve Anterior mediastinum Thymic remnants Lymph nodes Fat Middle mediastinum Pericardium Heart Aortic root Arch of azygos vein Main bronchi Posterior mediastinum Oesophagus Thoracic aorta Azygos vein Thoracic duct Vagus nerve Sympathetic nerve trunks Splanchnic nerves

Answer 1053

The middle adrenal artery is usually a branch of the aorta, the lower adrenal artery typically arises from the renal vessels. Adrenal gland anatomy Anatomy Location Superomedially to the upper pole of each kidney Relationships of the right adrenal Diaphragm-Posteriorly, Kidney-Inferiorly, Vena Cava-Medially, Hepato-renal pouch and bare area of the liver-Anteriorly Relationships of the left adrenal Crus of the diaphragm-Postero- medially, Pancreas and splenic vessels-Inferiorly, Lesser sac and stomach-Anteriorly Arterial supply Superior adrenal arteries- from inferior phrenic artery, Middle adrenal arteries - from aorta, Inferior adrenal arteries -from renal arteries Venous drainage of the right adrenal Via one central vein directly into the IVC Venous drainage of the left adrenal Via one central vein into the left renal vein

Answer 1054

Impalpable testes are an indication for laparoscopy. Ultrasound is a relatively unhelpful tool in evaluating cryptorchid patients and most experienced paediatric surgeons would not use it pre-operatively. They may be associated with an intra-abdominal location. Whilst it is reasonable to defer orchidopexy for retractile testis completely absent testes should be investigated further. Cryptorchidism A congenital undescended testis is one that has failed to reach the bottom of the scrotum by 3 months of age. At birth up to 5% of boys will have an undescended testis, post natal descent occurs in most and by 3 months the incidence of cryptorchidism falls to 1-2%. In the vast majority of cases the cause of the maldescent is unknown. A proportion may be associated with other congenital defects including: Patent processus vaginalis Abnormal epididymis Cerebral palsy Developmental delay Wilms tumour Abdominal wall defects (e.g. gastroschisis, prune belly syndrome) Differential diagnosis These include retractile testes and, in the case of absent bilateral testes the possibility of intersex conditions. A retractile testis can be brought into the scrotum by the clinician and when released remains in the scrotum. If the examining clinician notes the testis to return rapidly into the inguinal canal when released then surgery is probably indicated. Reasons for correction of cryptorchidism Reduce risk of infertility Allows the testes to be examined for testicular cancer Avoid testicular torsion Cosmetic appearance Males with undescended testis are 40 times as likely to develop testicular cancer (seminoma) as males without undescended testis The location of the undescended testis affects the relative risk of testicular cancer (50% intra-abdominal testes) Treatment Orchidopexy at 6- 18 months of age. The operation usually consists of inguinal exploration, mobilisation of the testis and implantation into a dartos pouch. Intra-abdominal testis should be evaluated laparoscopically and mobilised. Whether this is a single stage or two stage procedure depends upon the exact location. After the age of 2 years in untreated individuals the Sertoli cells will degrade and those presenting late in teenage years may be better served by orchidectomy than to try and salvage a non functioning testis with an increased risk of malignancy.

Answer 1055

Dextran 40 and 70 have higher incidence of anaphylaxis than either gelatins or starches. Dextrans are branched polysaccharide molecules. Dextran 40 and 70 are available. The higher molecular weight dextran 70 may persist for up to 8 hours. They inhibit platelet aggregation and leucocyte plugging in the microcirculation. Thereby improving flow through the microcirculation, primarily of use in sepsis. Unlike many other intravenous fluids Dextrans are a recognised cause of anaphylaxis. Post operative fluid management Composition of commonly used intravenous fluids mmol-1 Na K Cl Bicarbonate Lactate Plasma 137-147 4-5.5 95-105 22-25 - 0.9% Saline 153 - 153 - - Dextrose / saline 30.6 - 30.6 - - Hartmans 130 4 110 - 28 Post operative fluid management In the UK the GIFTASUP and NICE (CG174 2017) guidelines (see reference below) were devised to try and provide some consensus guidance as to how intravenous fluids should be administered. Some time ago it was a commonly held belief that little harm would occur as a result of excessive administration of normal saline and many oliguric post operative patients received enormous quantities of IV fluids. As a result they developed hyperchloraemic acidosis. With greater understanding of this potential complication, the use of electrolyte balanced solutions (Ringers lactate/ Hartmans) is now favored over normal saline. The other guidance includes: Fluids given should be documented clearly and easily available Assess the patient's fluid status when they leave theatre If a patient is haemodynamically stable and euvolaemic, aim to restart oral fluid intake as soon as possible Review patients whose urinary sodium is < 20 If a patient is oedematous, hypovolaemia if present should be treated first. This should then be followed by a negative balance of sodium and water, monitored using urine Na excretion levels Solutions such as Dextran 70 should be used in caution in patients with sepsis as there is a risk of developing acute renal injury References NICE guidance CG174. Intravenous fluid therapy in adults. May 2017. NICE guidance NG29. Intravenous fluid therapy in children and young people in hospital (2020) British Consensus Guidelines on Intravenous Fluid Therapy for Adult Surgical Patients. GIFTASUP (2009)

Answer 1056

Typically the pancreas secretes between 1000 and 1500ml per day. Pancreas exocrine physiology Composition of pancreatic secretions Pancreatic secretions are usually 1000-1500ml per 24 hours and have a pH of 8. Secretion Source Substances secreted Enzymic Acinar cells Trypsinogen Procarboxylase Amylase Elastase Aqueous Ductal and Centroacinar cells Sodium Bicarbonate Water Potassium Chloride NB: Sodium and potassium reflect their plasma levels; chloride and bicarbonate vary with flow rate Regulation The cephalic and gastric phases (neuronal and physical) are less important in regulating the pancreatic secretions. The effect of digested material in the small bowel stimulates CCK release and ACh which stimulate acinar and ductal cells. Of these CCK is the most potent stimulus. In the case of the ductal cells these are potently stimulated by secretin which is released by the S cells of the duodenum. This results in an increase in bicarbonate. Enzyme activation Trypsinogen is converted via enterokinase to active trypsin in the duodenum. Trypsin then activates the other inactive enzymes

Answer 1057

Long standing pathology is usually the cause of massive splenomegaly. Of these, its a common finding in chronic leukaemia. Its rare for EBV infections to cause massive splenomegaly. Disorders affecting the spleen One of the commonest conditions to affect the spleen is traumatic rupture and this is addressed elsewhere. Splenomegaly Enlargement of the spleen can commonly accompany a variety of haematological disorders. Of these, chronic conditions such as haemolytic anaemia and chronic leukaemia are often associated with splenomegaly. More acute haematological conditions tend not to cause massive splenic enlargement. Infections with parasites (such as malaria) and viruses such as Epstein Barr virus can cause splenomegaly and this one condition that is associated with sudden spontaneous splenic rupture. Portal hypertension can result in splenomegaly and the finding of an enlarged spleen on abdominal examination should prompt a search for the other stigmata of chronic liver disease. Splenic atrophy This typically occurs as a result of conditions that impair the blood flow to the spleen. Division of some of the major vessels can cause shrinkage of the spleen and this is commonly seen when splenic artery aneurysms are coiled for example.

Answer 1058

Causes of increased anion acidosis: MUDPILES M - Methanol U - Uraemia D - DKA/AKA P - Paraldehyde/phenformin I - Iron/INH L - Lactic acidosis E - Ethylene glycol S - Salicylates Uraemia, paraldehyde, diabetic ketoacidosis, and ethylene glycol are all known to cause increased anion gap acidosis. Uraemia is a condition in which there is a buildup of urea and other nitrogenous wastes in the blood, leading to the production of acidic metabolites. Paraldehyde is a medication used to treat alcohol withdrawal, but it can cause metabolic acidosis due to the accumulation of acetaldehyde. Diabetic ketoacidosis is a complication of diabetes in which there is an accumulation of ketone bodies in the blood, leading to metabolic acidosis. Ethylene glycol, which is found in antifreeze, can be metabolized into acidic metabolites that can cause metabolic acidosis. Acetazolamide, on the other hand, is a medication that works by inhibiting carbonic anhydrase, an enzyme that is involved in the production of bicarbonate in the body. As a result, acetazolamide can cause a non-anion gap metabolic acidosis due to the loss of bicarbonate, but it does not cause an increased anion gap acidosis.

Answer 1059

The anterior interosseous nerve is a motor branch of the median nerve just below the elbow. When damaged it classically causes: Pain in the forearm Loss of pincer movement of the thumb and index finger (innervates the long flexor muscles of flexor pollicis longus & flexor digitorum profundus of the index and middle finger) Minimal loss of sensation due to lack of a cutaneous branch Median nerve The median nerve is formed by the union of a lateral and medial root respectively from the lateral (C5,6,7) and medial (C8 and T1) cords of the brachial plexus; the medial root passes anterior to the third part of the axillary artery. The nerve descends lateral to the brachial artery, crosses to its medial side (usually passing anterior to the artery). It passes deep to the bicipital aponeurosis and the median cubital vein at the elbow. It passes between the two heads of the pronator teres muscle, and runs on the deep surface of flexor digitorum superficialis (within its fascial sheath). Near the wrist it becomes superficial between the tendons of flexor digitorum superficialis and flexor carpi radialis, deep to palmaris longus tendon. It passes deep to the flexor retinaculum to enter the palm, but lies anterior to the long flexor tendons within the carpal tunnel. Branches Region Branch Upper arm No branches, although the nerve commonly communicates with the musculocutaneous nerve Forearm Pronator teres Pronator quadratus Flexor carpi radialis Palmaris longus Flexor digitorum superficialis Flexor pollicis longus Flexor digitorum profundus (only the radial half) Distal forearm Palmar cutaneous branch Hand (Motor) Motor supply (LOAF) Lateral 2 lumbricals Opponens pollicis Abductor pollicis brevis Flexor pollicis brevis Hand (Sensory) Over thumb and lateral 2 Â½ fingers On the palmar aspect this projects proximally, on the dorsal aspect only the distal regions are innervated with the radial nerve providing the more proximal cutaneous innervation. Patterns of damage Damage at wrist e.g. carpal tunnel syndrome paralysis and wasting of thenar eminence muscles and opponens pollicis (ape hand deformity) sensory loss to palmar aspect of lateral (radial) 2 Â½ fingers Damage at elbow, as above plus: unable to pronate forearm weak wrist flexion ulnar deviation of wrist Anterior interosseous nerve (branch of median nerve) leaves just below the elbow results in loss of pronation of forearm and weakness of long flexors of thumb and index finger

Answer 1060

This is likely to be Fournier's Gangrene. A number of agents are implicated. E-coli and bacteroides are the most commonly isolated organisms. The key point is that both aerobic and anaerobic organisms must be present. This is likely to be Fournier's Gangrene. A number of agents are implicated. E-coli and bacteroides are the most commonly isolated organisms. The key point is that both aerobic and anaerobic organisms must be present. This is likely to be Fournier's Gangrene. A number of agents are implicated. E-coli and bacteroides are the most commonly isolated organisms. The key point is that both aerobic and anaerobic organisms must be present.

Answer 1061

Asteroid bodies are often found in the granulomas of individuals with sarcoid. Unlike the granulomata associated with tuberculosis the granulomas of sarcoid are rarely associated with extensive necrosis. Psammoma bodies are concentrically lamellated calcific structures that can be found in various tissues, particularly in tumors and lesions. They are typically small, round, and resemble grains of sand under the microscope, hence the name “psammoma,” which is derived from the Greek word for sand. These bodies are often observed in certain types of tumors, including: 1. Papillary Thyroid Carcinoma: Psammoma bodies are commonly found in papillary thyroid carcinoma, a type of thyroid cancer. 2. Meningioma: They can also be present in meningiomas, which are tumors that arise from the meninges, the protective membranes surrounding the brain and spinal cord. 3. Serous Ovarian Carcinoma: Psammoma bodies can occur in serous ovarian carcinoma, a type of ovarian cancer. Psammoma bodies are formed through a process called dystrophic calcification, where calcium salts are deposited in tissues that are undergoing degeneration or necrosis. While their exact significance is not fully understood, their presence can aid in the diagnosis of certain tumors when observed in histological specimens. Understanding the presence of psammoma bodies in tissues can assist pathologists in identifying specific types of tumors and guiding treatment decisions for patients.

Answer 1062

Mnemonic: Standing Room Only -Exit of branches of trigeminal nerve from the skull V1 -Superior orbital fissure V2 -foramen Rotundum V3 -foramen Ovale The opthalmic branch of the trigeminal nerve exits the skull through the superior orbital fissure. Trigeminal nerve The trigeminal nerve is the main sensory nerve of the head. In addition to its major sensory role, it also innervates the muscles of mastication. Distribution of the trigeminal nerve Sensory Scalp Face Oral cavity (and teeth) Nose and sinuses Dura mater Motor Muscles of mastication Mylohyoid Anterior belly of digastric Tensor tympani Tensor palati Autonomic connections (ganglia) Ciliary Sphenopalatine Otic Submandibular Path Originates at the pons Sensory root forms the large, crescentic trigeminal ganglion within Meckel's cave, and contains the cell bodies of incoming sensory nerve fibres. Here the 3 branches exit. The motor root cell bodies are in the pons and the motor fibres are distributed via the mandibular nerve. The motor root is not part of the trigeminal ganglion. Branches of the trigeminal nerve Ophthalmic nerve Sensory only Maxillary nerve Sensory only Mandibular nerve Sensory and motor Sensory Ophthalmic Exits skull via the superior orbital fissure Sensation of: scalp and forehead, the upper eyelid, the conjunctiva and cornea of the eye, the nose (including the tip of the nose, except alae nasi), the nasal mucosa, the frontal sinuses, and parts of the meninges (the dura and blood vessels). Maxillary nerve Exit skull via the foramen rotundum Sensation: lower eyelid and cheek, the nares and upper lip, the upper teeth and gums, the nasal mucosa, the palate and roof of the pharynx, the maxillary, ethmoid and sphenoid sinuses, and parts of the meninges. Mandibular nerve Exit skull via the foramen ovale Sensation: lower lip, the lower teeth and gums, the chin and jaw (except the angle of the jaw), parts of the external ear, and parts of the meninges. Motor Distributed via the mandibular nerve. The following muscles of mastication are innervated: Masseter Temporalis Medial pterygoid Lateral pterygoid Other muscles innervated include: Tensor veli palatini Mylohyoid Anterior belly of digastric Tensor tympani

Answer 1063

The 5th tendon sheath extends from the little finger to the proximal aspect of the carpal tunnel. This carries a significant risk of allowing infections to migrate proximally. Hand Anatomy of the hand Bones 8 Carpal bones 5 Metacarpals 14 phalanges Intrinsic Muscles 8 Interossei - Supplied by ulnar nerve 4 palmar-adduct fingers 4 dorsal- abduct fingers Intrinsic muscles Lumbricals Flex MCPJ and extend the IPJ. Origin deep flexor tendon and insertion dorsal extensor hood mechanism. Innervation: 1st and 2nd- median nerve, 3rd and 4th- deep branch of the ulnar nerve. Thenar eminence Abductor pollicis brevis Opponens pollicis Flexor pollicis brevis Hypothenar eminence Opponens digiti minimi Flexor digiti minimi brevis Abductor digiti minimi Fascia and compartments of the palm The fascia of the palm is continuous with the antebrachial fascia and the fascia of the dorsum of the hand. The palmar fascia is thin over the thenar and hypothenar eminences. In contrast, the central palmar fascia is relatively thick. The palmar aponeurosis covers the soft tissues and overlies the flexor tendons. The apex of the palmar aponeurosis is continuous with the flexor retinaculum and the palmaris longus tendon. Distally, it forms four longitudinal digital bands that attach to the bases of the proximal phalanges, blending with the fibrous digital sheaths. A medial fibrous septum extends deeply from the medial border of the palmar aponeurosis to the 5th metacarpal. Lying medial to this are the hypothenar muscles. In a similar fashion, a lateral fibrous septum extends deeply from the lateral border of the palmar aponeurosis to the 3rd metacarpal. The thenar compartment lies lateral to this area. Lying between the thenar and hypothenar compartments is the central compartment. It contains the flexor tendons and their sheaths, the lumbricals, the superficial palmar arterial arch and the digital vessels and nerves. The deepest muscular plane is the adductor compartment, which contains adductor pollicis. Short muscles of the hand These comprise the lumbricals and interossei. The four slender lumbrical muscles flex the fingers at the metacarpophalangeal joints and extend the interphalangeal joint. The four dorsal interossei are located between the metacarpals and the four palmar interossei lie on the palmar surface of the metacarpals in the interosseous compartment of the hand. Long flexor tendons and sheaths in the hand The tendons of FDS and FDP enter the common flexor sheath deep to the flexor retinaculum. The tendons enter the central compartment of the hand and fan out to their respective digital synovial sheaths. Near the base of the proximal phalanx, the tendon of FDS splits to permit the passage of FDP. The FDP tendons are attached to the margins of the anterior aspect of the base of the distal phalanx. The fibrous digital sheaths contain the flexor tendons and their synovial sheaths. These extend from the heads of the metacarpals to the base of the distal phalanges. Palmar Interossei Note that there are 4 palmar interossei. The first is a small slip of muscle which arises from the ulnar side of the base of the first metacarpal and passes between the head of the first dorsal interosseous and the oblique head of adductor pollicis to insert into the ulnar base of the of the proximal phalanx of the thumb. The second arises from the ulnar side of the body of the second metacarpal and is inserted into the ulnar side of the extensor hood of the index. The third and fourth palmar interossei arise from the radial sides of the bodies of the 4th and 5th metacarpals respectively and insert into the radial sides of the extensor hoods of the ring and little fingers.

Answer 1064

Bile salts are absorbed in the terminal ileum. When this process is impaired as in Crohns the patient may develop gallstones, if these pass into the CBD then obstructive jaundice will result. Surgical jaundice Jaundice can present in a manner of different surgical situations. As with all types of jaundice a careful history and examination will often give clues as to the most likely underlying cause. Liver function tests whilst conveying little in the way of information about liver synthetic function, will often facilitate classification as to whether the jaundice is pre hepatic, hepatic or post hepatic. The typical LFT patterns are given below: Location Bilirubin ALT/ AST Alkaline phosphatase Pre hepatic Normal or high Normal Normal Hepatic High Elevated (often very high) Elevated but seldom to very high levels Post hepatic High-very high Moderate elevation High- very high In post hepatic jaundice the stools are often of pale colour and this feature should be specifically addressed in the history. Modes of presentation These are addressed in the table below: Diagnosis Typical features Pathogenesis Gallstones Typically history of biliary colic or episodes of chlolecystitis. Obstructive type history and test results. Usually small calibre gallstones which can pass through the cystic duct. In Mirizzi syndrome the stone may compress the bile duct directly- one of the rare times that cholecystitis may present with jaundice Cholangitis Usually obstructive and will have Charcots triad of symptoms (pain, fever, jaundice) Ascending infection of the bile ducts usually by E. coli and by definition occurring in a pool of stagnant bile. Pancreatic cancer Typically painless jaundice with palpable gallbladder (Courvoisier's Law) Direct occlusion of distal bile duct or pancreatic duct by tumour. Sometimes nodal disease at the portal hepatis may be the culprit in which case the bile duct may be of normal calibre. TPN associated jaundice Usually follows long term use and is usually painless with non obstructive features Often due to hepatic dysfunction and fatty liver which may occur with long term TPN usage. Bile duct injury Depending upon the type of injury may be of sudden or gradual onset and is usually of obstructive type Often due to a difficult cholecystectomy when anatomy in Calots triangle is not appreciated. In the worst scenario the bile duct is excised and jaundice offers rapidly post operatively. More insidious is that of bile duct stenosis which may be caused by clips or diathermy injury. Cholangiocarcinoma Gradual onset obstructive pattern Direct occlusion by disease and also extrinsic compression by nodal disease at the porta hepatis. Septic surgical patient Usually hepatic features Combination of impaired biliary excretion and drugs such as ciprofloxacin which may cause cholestasis. Metastatic disease Mixed hepatic and post hepatic Combination of liver synthetic failure (late) and extrinsic compression by nodal disease and anatomical compression of intra hepatic structures (earlier) Diagnosis An ultrasound of the liver and biliary tree is the most commonly used first line test. This will establish bile duct calibre, often ascertain the presence of gallstones, may visualise pancreatic masses and other lesions. The most important clinical question is essentially the extent of biliary dilatation and its distribution. Where pancreatic neoplasia is suspected, the next test should be a pancreatic protocol CT scan. With liver tumours and cholangiocarcinoma an MRI/ MRCP is often the preferred option. PET scans may be used to stage a number of malignancies but do not routinely form part of first line testing. Where MRCP fails to give adequate information an ERCP may be necessary. In many cases this may form part of patient management. It is however, invasive and certainly not without risk and highly operator dependent. Management Clearly this will depend to an extent upon the underlying cause but relief of jaundice is important, even if surgery forms part of the planned treatment. Patients with unrelieved jaundice have a much higher incidence of septic complications, bleeding and death. Screen for and address any clotting irregularities In patients with malignancy a stent will need to be inserted. These come in two main types; metal and plastic. Plastic stents are cheap and easy to replace and should be used if any surgical intervention (e.g. Whipples) is planned. However, they are prone to displacement and blockage. Metal stents are much more expensive and may compromise a surgical resection. However, they are far less prone to displacement and to a lesser extent blockage than their plastic counterparts. If malignancy is in bile duct/ pancreatic head and stenting has been attempted and has failed, then an alternative strategy is to drain the biliary system percutaneously via a transhepatic route. It may also be possible to insert a stent in this way. One of the main problems with temporary PTC's is their propensity to displacement, which may result in a bile leak. In patients who have a bile duct injury surgery will be required to repair the defect. If the bile duct has been inadvertently excised then a hepatico-jejunostomy will need to be created (difficult!) If gallstones are the culprit, then these may be removed by ERCP and a cholecystectomy performed. Where there is doubt about the efficacy of the ERCP an operative cholangiogram should be performed and bile duct exploration undertaken where stones remain. When the bile duct has been formally opened the options are between closure over a T tube, a choledochoduodenostomy or choledochojejunostomy. Patients with cholangitis should receive high dose broad spectrum antibiotics via the intravenous route. Biliary decompression should follow soon afterwards, instrumenting the bile duct of these patients will often provoke a septic episode (but should be done anyway).

Answer 1065

Halothane is largely of historical interest and that is because of its hepatotoxicity. Anaesthetic agents The table below summarises some of the more commonly used IV induction agents Agent Specific features Propofol Rapid onset of anaesthesia Pain on IV injection Rapidly metabolised with little accumulation of metabolites Proven anti emetic properties Moderate myocardial depression Widely used especially for maintaining sedation on ITU, total IV anaesthesia and for daycase surgery Sodium thiopentone Extremely rapid onset of action making it the agent of choice for rapid sequence of induction Marked myocardial depression may occur Metabolites build up quickly Unsuitable for maintenance infusion Little analgesic effects Ketamine May be used for induction of anaesthesia Has moderate to strong analgesic properties Produces little myocardial depression making it a suitable agent for anaesthesia in those who are haemodynamically unstable May induce state of dissociative anaesthesia resulting in nightmares Etomidate Has favorable cardiac safety profile with very little haemodynamic instability No analgesic properties Unsuitable for maintaining sedation as prolonged (and even brief) use may result in adrenal suppression Post operative vomiting is common

Answer 1066

It's boundaries are extensor pollicis longus medially and laterally by the tendons of abductor pollicis longus and extensor pollicis brevis. Anatomical snuffbox Posterior border Tendon of extensor pollicis longus Anterior border Tendons of extensor pollicis brevis and abductor pollicis longus Proximal border Styloid process of the radius Distal border Apex of snuffbox triangle Floor Trapezium and scaphoid Content Radial artery

Answer 1067

Frozen shoulder is more likely. Metastatic cancer can cause pain. However, passive movements are normally unaffected. Frozen shoulder passes through an initial painful stage followed by a period of joint stiffness. With physiotherapy the problem will usually resolve although it may take up to 2 years to do so. Shoulder disorders Shoulder fractures and dislocations Fractures Proximal humerus Background Third most common fragility fracture in the elderly. Results from low energy fall in predominantly elderly females, or from high energy trauma in young males. Can be associated with nerve injury (commonly axillary), and fracture-dislocation of the humeral head. Detailed neurological assessment is essential for all upper limb injuries. Anatomy Osteology Consists of articular head, greater tuberosity, lesser tuberosity, metaphysis and diaphysis. Between the articular head and the tuberosities is the anatomical neck (previous physis). Between the tuberosities and the metaphysis is the surgical neck. The supraspinatus, infraspinatus and teres minor muscles attach to the greater tuberosity. The subscapularis muscle attaches to the lesser tuberosity. Vascular Supply Humeral head is supplied by the anterior and posterior humeral circumflex arteries. Anatomical neck fractures are at greatest risk of osteonecrosis. Imaging Imaging aims to both delineate the fracture pattern, and confirm/exlude the presence of an associated dislocation. Radiographs - True anteroposterior (AP), axillary lateral and/or scapula Y view. CT - indicated to better define intra-articular involvement and to aid pre-operative planning. MRI is not useful for fracture imaging. Classification Description of the fracture is often more useful than classification. Particular attention should be paid to humeral alignment, fracture displacement, and greater tuberosity position (rotator cuff will pull the GT supero-posterioly, which can cause impingement problems with malunion). - Neer Classification: Most commonly used. Describes fracture as 2,3,or 4 part depending upon the number main fragments. Also comments on the degree of displacement. Fragments: -greater tuberosity -lesser tuberosity - articular surface - shaft Displacement: >1cm or angulation >45 degrees. Treatment The vast majority of proximal humeral fractures are minimally displaced, and therefore can be managed conservatively. This involves immobilisation in a polysling, and progressive mobilisation. Pendular exercise can commence at 14 days, and active abduction from 4-6 weeks. Irreducible fracture dislocation is an indication for operative management. Other indications include large displacement, younger patient, head splitting (intra-articular fractures). However, the recent PROFHER trial (1) has suggested no benefit to operative intervention on patient outcome (it must be applied cautiously as majority of patients were elderly with extraarticular fractures). Options available for surgical management include: ORIF Most commonly used. Plate and screw fixation. Can reconstruct complex fractures. Intramedullary nail Suitable for extra-articular configuration, predominantly surgical neck +/- GT fractures. Hemiarthroplasty Used for un-reconstructable fractures in the older patient who has good glenoid quality. Total shoulder arthroplasty Unconstructable fractures where high functioning shoulder is required (hemiarthroplasty will cause glenoid erosion) Reverse shoulder arthroplasty Total shoulder arthroplasty that provides better functional outcome than conventional total shoulder replacement. Scapula Background Uncommon fractures usually associated with high energy trauma. Most commonly involve scapula body or spine (50%), glenoid fossa and glenoid neck. Important to exclude associated life threatening injury. Imaging Plain radiographs should include true anteroposterior (AP), axillary lateral and/or scapula Y view. CT scanning is useful for defining intra-articular involvement, displacement and for three dimensional reconstruction. Classification Based on the location of the fracture (coracoid, acromion, glenoid neck, glenoid fossa, scapula body). Beware of ipsilateral glenoid neck and clavicle fracture -floating shoulder - where limb is effectively dissociated from axial skeleton. Treatment The vast majority of scapula fractures are amenable to conservative management, consisting of sling immobilisation for two weeks followed by early rehabilitation. Floating shoulder will usually require fixation, and consideration of surgery should also be given to intra-articular and displaced/angulated glenoid fractures. Dislocations Types Dislocations around the shoulder joint include glenohumeral dislocation, acromioclavicular joint disruption and sternoclavicular dislocation. Only glenohumeral dislocation will be covered here. Glenohumeral dislocation Diagnosis, classification and management are covered here. Background Shoulder dislocation is commonly seen in A&E. It has a high recurrence rate that is as high as 80% in teenagers. Initial management requires emergent reduction to prevent lasting chondral damage. Early assessment and management Usually a traumatic cause (multi-directional instability in frequent dislocations requires discussion with orthopaedics and is not covered here). Careful history, examination and documentation of neurovascular status of the limb, in particular the axillary nerve (regimental badge sensation). This should be re-assessed post manipulation. Early radiographs to confirm direction of dislocation. Initial management consists of emergent closed reduction under under entanox and analgesia, but often requires conscious sedation. Arm should then be immobilised in a polysling, and XR to confirm relocation. Imaging - True anteroposterior (AP), axillary lateral and/or scapula Y view. Reduced humeral head should lie between acromion and coracoid on lateral/scapula view. Types Direction Features Cause Examination Reduction techniques Anterior Most Common >90% Usually traumatic - anterior force on arm when shoulder is abducted, externally rotated Loss of shoulder contour - sulcus sign. Humeral head can be felt anteriorly. Hippocratic. Milch. Stimson. Kocher not advised due to complication of fracture Posterior 50% missed in A&E 50% traumatic, but classically post seizure or electrocution Shoulder locked in internal rotation. XR may show lightbulb appearance. Gentle lateral traction to adducted arm. Inferior Rare Associated with pectorals and rotator cuff tears, and glenoid fracture As for primary injury Management of primary injury Superior Rare Associated with acrominon/clavicle fracture As for primary injury Management of primary injury Associated injuries Bankart lesion - avulsion of the anterior glenoid labrum with an anterior shoulder dislocation (reverse Bankart if poster labrum in posterior dislocation). Hill Sachs defect - chondral impaction on posteriosuperior humeral head from contact with gleonoid rim. Can be large enough to lock shoulder, requiring open reduction. (Reverse Hill Sachs in posterior dislocation). Rotator cuff tear - increases with age. Greater or lesser tuberosity fracture - increases with age. Humeral neck fracture - shoulder fracture dislocation. More common in high energy trauma and elderly. Should be discussed with orthopaedics prior to any attempted reduction. Rotator Cuff Disease Rotator cuff disease is a spectrum of conditions that ranges from subacromial impingement to rotator cuff tears and eventually to rotator cuff arthropathy (arthritis). Anatomy The rotator cuff is a group of four muscles that are important in shoulder movements, and maintenance of glenohumeral stability. Muscle Scapular attachment Humeral attachment Action Innervation Supraspinatus Supraspinatus fossa Superior facet of greater tuberosity Initiation of abduction of humerus Suprascapular nerve Infraspinatus Infraspinatus fossa Posterior facet of greater tuberosity External rotation of humerus Suprascapular nerve Teres Minor Lateral border Inferior facet of greater tuberosity External rotation of humerus Axillary Nerve Subscapularis Subscapular fossa Lesser tuberosity Internal rotation of humerus Upper and lower subscapular nerve The inferior rotator cuff muscles (infraspinatus, teres minor, and subscapularis) balance the superior pull of the deltoid. Injury/tear results in upward migration of the humeral head on the glenoid (can be seen on AP radiograph). Likewise, the anterior muscles (subscapularis) are balanced with the posterior muscles (infraspinatus, teres minor). Subacromial Impingement The most common cause of shoulder pain, which results from impingement of the superior cuff on the undersurface of the acromion, and an inflammatory bursitis. Associated with certain types of acromial morphology (Bigliani classification). Presents as insidious pain which is exacerbated by overhead activities. Rotator Cuff Tear Often presents as an acute event on the background of chronic subacromial impingement in the older patient, but can present as an avulsion injury in younger patients. Majority of tears are to the superior cuff (supraspinatus, infraspinatus, teres minor), though a tear to subscapularis is associated with subcoracoid impingement. Tears present as pain and weakness when using the muscles in question. Rotator Cuff Arthropathy Defined as shoulder arthritis in the setting of rotator cuff dysfunction. Results from superior migration due to the loss of rotator cuff function and integrity. Unopposed deltoid pulls the humeral head superiorly. Associated with massive chronic cuff tears. Imaging Plain radiographs AP of the shoulder may show superior migration of the humerus with a cuff tear, and features of arthritis with arthropathy. Other causes of pain may also be identified (e.g. calcific tendonitis/fracture) Outlet view is useful for defining the acromial morphology USS Allows dynamic imaging of the cuff, and is inexpensive. However, it is very user dependent. MRI Best imaging modality for cuff pathology. Also allows imaging of the rest of the shoulder. When intra-articular pathology is suspected, can be combined with an arthrogram for improved sensitivity and specificity. Treatment Subacromial impingement Physiotherapy, oral anti-inflammatory medication Subacromial steroid injection can settle inflammation Arthroscopic subacromial decompression by shaving away the undersurface of the acromion, more space is created for the rotator cuff. Cuff integrity is assessed also at time of surgery, and can be repaired if necessary. Rotator cuff tear When considering repair of a cuff tear, the age and activity of the patient, the nature of the tear (degenerative vs. acute traumatic), and the size and retraction of the tear should be considered when making a surgical plan. Mild tears or tears in the elderly can be managed conservatively, as outlined above. Moderate tears can be repaired arthroscopically. Massive or retracted tears will often require an open repair (occasionally with a tendon transfer). Subacromial decompression is performed at the same time to reduce impingement, symptoms and recurrence. Calcific tendonitis Calcific tendonitis involves calcific deposits within tendons anywhere in the body, but most commonly in the rotator cuff (specifically the supraspinatus tendon). When present in the shoulder, it is associated with subacromial impingement and pain. Pathology More common in women aged 30-60 years. Association with diabetes and hypothyroidism There are three stages of calcification Formative phase characterized by calcific deposits Resting phase deposit is stable, but presents with impingement problems Resorptive phase phagocytic resorption. Most painful stage. Presentation Similar in presentation to subacromial impingement, with pain especially with over head activities. Atraumatic in nature. Imaging Plain radiographs show calcification of the rotator cuff, usually within 1.5cm of its insertion on the humerus. Supraspinatus outlet views can show level of impingment. Further imaging is rarely needed. Treatment Non-operative NSAIDS, steroid injection (controversial, but practiced) and physiotherapy. Approximately 75% will resolve by 6 months with conservative management. Ultrasound guided or surgical needle barbotage can break down deposits and resolve symptoms. Occasionally surgical excision is required. Adhesive capsulitis (Frozen Shoulder) Pain and loss of movement of shoulder joint, which involves fibroplastic proliferation of capsular tissue, causing soft tissue scarring and contracture. Patients present with a painful and decreased arc of motion. Associated with prolonged immobilization, previous surgery, thyroid disorders (AI) and diabetes Classically three stages which can take up to two years to resolve: Stage one the freezing and painful stage Stage two the frozen and stiff stage Stage three the thawing stage, where shoulder movement slowly improves Imaging Plain radiographs to exclude other causes of a painful shoulder MRI arthrogram may show capsular contracture, and again may be used to exclude cuff pathology. However, often not performed as diagnosis is largely clinical. Treatment Non-operative NSAIDS, steroid injection and physiotherapy. Patience is required as condition can take up to 2 years to improve. Operative MUA or arthroscopic adhesiolysis (release of adhesions) can expedite recovery, followed by intensive physiotherapy. Glenohumeral Arthritis Background May be osteoarthritis (primary or secondary to cuff tear or trauma), rheumatoid arthritis, or as part of a spondyloarthropathy. Majority of those with RA will develop symptoms. More common in the elderly Presents like any other arthritis - pain at night and with movement Imaging AP and axillary radiographs will show features of arthritis. CT/MRI is often useful to classify the shape of the glenoid and extent of bone loss when considering arthroplasty. MRI also essential to asses integrity of rotator cuff if considering shoulder replacement. Treatment Like all orthopaedics, start with simple measures: NSAIDS, management of RA, physiotherapy, steroid injection. Hemiarthroplasty can sometimes be considered if glenoid is in excellent condition or if patient has large comorbidity. Arthroscopic debridement is useful if patient has isolated ACJ arthritis, but is rarely used for glenohumeral arthritis. Total shoulder replacement is shown to produce superior outcome when compared to hemiarthroplasty in terms of pain relief, function and implant survival. Total shoulder replacement can be anatomical (ball on humerus, with cup on glenoid), or reverse geometry (ball on glenoid, with cup on humerus). Anatomical TSR requires an in tact rotator cuff, so often reverse is preferable when the cuff if questionable in integrity. References 1. JAMA. 2015;313(10):1037-1047. doi:10.1001/jama.2015.1629

Answer 1068

The anhidrosis will be mild as this is a distal lesion and at worst only a very limited area of the ipsilateral face will be anhidrotic. Horners syndrome Horners syndrome, clinical features: Ptosis Miosis Enopthalmos Anhydrosis Primarily a disorder of the sympathetic nervous system. Extent of symptoms depends upon the anatomical site of the lesion. Proximal lesions occur along the hypothalamospinal tract Distal lesions are usually post ganglionic e.g. at level of internal carotid artery or beyond.

Answer 1069

Suxamethonium may cause malignant hyperthermia and 1 in 2800 will have abnormal cholinesterase enzyme and prolonged clinical effect. Muscle relaxants Suxamethonium Depolarising neuromuscular blocker Inhibits action of acetylcholine at the neuromuscular junction Degraded by plasma cholinesterase and acetylcholinesterase (affected by lack of acetylcholinesterase) Fastest onset and shortest duration of action of all muscle relaxants Produces generalised muscular contraction prior to paralysis Adverse effects include hyperkalaemia, malignant hyperthermia, delayed recovery Atracurium Non depolarising neuromuscular blocking drug Duration of action usually 30-45 minutes Generalised histamine release on administration may produce facial flushing, tachycardia and hypotension Not excreted by liver or kidney, broken down in tissues by hydrolysis Reversed by neostigmine Vecuronium Non depolarising neuromuscular blocking drug Duration of action approximately 30 - 40 minutes Degraded by liver and kidney and effects prolonged in organ dysfunction Effects may be reversed by neostigmine Pancuronium Non depolarising neuromuscular blocker Onset of action approximately 2-3 minutes Duration of action up to 2 hours Effects may be partially reversed with drugs such as neostigmine

Answer 1070

Ethmoidal sinusitis may spread to the periorbital tissues resulting in periorbital cellulitis. The superomedial distribution makes a maxillary sinusitis less likely. Diseases of nose and sinuses Benign Tumours Simple papillomas may be an incidental finding or present with obstructive symptoms. Excision under general anaesthesia is sufficient management. Transitional cell papillomas may be more extensive and produce obstructive symptoms. Erosion of local structures is a recognised complication. These lesions may rarely undergo malignant transformation and therefore careful and complete excision is required, some cases may require partial or total maxillectomy. Pleomorphic adenomas of the maxillary sinuses are reported but are extremely rare, their symptoms typically include nasal obstruction and pain if the sinus is obstructed. Treatment is by complete surgical excision, the diagnosis is not infrequently made post operatively. Benign osteomas may develop in the paranasal sinuses, the frontal sinus is the most frequent location of such lesions. Symptoms include; pain, rhinorrhoea and anosmia. Most osteomas may be observed if asymptomatic, sphenoid osteomas should be resected soon after diagnosis as enlargement may compromise visual fields. Many sinus osteomas can now be resected endoscopically, complete surgical resection is required. Nasal polyps are benign lesions of the ethmoid sinus mucosa. Many patients may also have asthma, cystic fibrosis and a sensitivity to aspirin. Symptoms include watery rhinorrhoea, infection and anosmia. The polyps are usually a semi transparent grey mass. They are rare in childhood. Treatment is either with systemic steroids or surgical resection. The latter should be combined with antral washout. Low dose, nasal, steroid drops may reduce the risk of recurrence. Malignant disease Malignancies encountered in the nose and paranasal sinuses include; adenoid cystic carcinoma, squamous cell carcinoma and adenocarcinoma. Adenocarcinoma of the paranasal sinuses and nasopharynx is strongly linked to exposure to hard wood dust (after >10 years exposure). Adenoid cystic carcinoma usually originate in the smaller salivary glands. The majority of cancers (50%) arise from the lateral nasal wall, a smaller number (33%) arise from the maxillary antrum, ethmoid and sphenoid cancers comprise only 7%. Signs of malignancy on clinical examination include loose teeth, cranial nerve palsies and lymphadenopathy. Nasopharyngeal cancers are most common in individuals presenting from China and Asia and are linked to viral infection with Epstein Barr Virus. Radiotherapy and chemotherapy are the most commonly used modalities. Maxillary sinusitis Common symptoms include post nasal discharge, pain, headache and toothache. Imaging may show a fluid level in the antrum. Common organisms include Haemophilus influenzae or Streptococcus pneumoniae. Treatment with antral lavage may facilitate diagnosis and relieve symptoms. Antimicrobial therapy has to be continued for long periods. Antrostomy may be needed. Frontoethmoidal sinusitis Usually presents with frontal headache, nasal obstruction and altered sense of smell. Inflammation may progress to involve periorbital tissues. Ocular symptoms may occur and secondary CNS involvement brought about by infection entering via emissary veins. CT scanning is the imaging modality of choice. Early cases may be managed with antibiotics. More severe cases usually require surgical drainage.

Answer 1071

The thoracic duct lies within the posterior and superior mediastinum. Mediastinum Region between the pulmonary cavities. It is covered by the mediastinal pleura. It does not contain the lungs. It extends from the thoracic inlet superiorly to the diaphragm inferiorly. Mediastinal regions Superior mediastinum (between manubriosternal angle and T4/5) Middle mediastinum Posterior mediastinum Anterior mediastinum Region Contents Superior mediastinum Superior vena cava Brachiocephalic veins Arch of aorta Thoracic duct Trachea Oesophagus Thymus Vagus nerve Left recurrent laryngeal nerve Phrenic nerve Anterior mediastinum Thymic remnants Lymph nodes Fat Middle mediastinum Pericardium Heart Aortic root Arch of azygos vein Main bronchi Posterior mediastinum Oesophagus Thoracic aorta Azygos vein Thoracic duct Vagus nerve Sympathetic nerve trunks Splanchnic nerves

Answer 1072

Liver cell adenomas are linked to OCP use and 90% of patients with liver cell adenomas have used the OCP. Liver function tests are often normal. The lesions will typically have a mixed echoity and heterogeneous texture. Benign liver lesions Benign liver lesions Haemangioma Most common benign tumours of mesenchymal origin Incidence in autopsy series is 8% Cavernous haemangiomas may be enormous Clinically they are reddish purple hypervascular lesions Lesions are normally separated from normal liver by ring of fibrous tissue On ultrasound they are typically hyperechoic Liver cell adenoma 90% develop in women in their third to fifth decade Linked to use of oral contraceptive pill Lesions are usually solitary They are usually sharply demarcated from normal liver although they usually lack a fibrous capsule On ultrasound the appearances are of mixed echoity and heterogeneous texture. On CT most lesions are hypodense when imaged prior to administration of IV contrast agents In patients with haemorrhage or symptoms removal of the adenoma may be required Mesenchymal hamartomas Congential and benign, usually present in infants. May compress normal liver Liver abscess Biliary sepsis is a major predisposing factor Structures drained by the portal venous system form the second largest source Common symptoms include fever, right upper quadrant pain. Jaundice may be seen in 50% Ultrasound will usually show a fluid filled cavity, hyperechoic walls may be seen in chronic abscesses Amoebic abscess Liver abscess is the most common extra intestinal manifestation of amoebiasis Between 75 and 90% lesions occur in the right lobe Presenting complaints typically include fever and right upper quadrant pain Ultrasonography will usually show a fluid filled structure with poorly defined boundaries Aspiration yield sterile odourless fluid which has an anchovy paste consistency Treatment is with metronidazole Hyatid cysts Seen in cases of Echinococcus infection Typically an intense fibrotic reaction occurs around sites of infection The cyst has no epithelial lining Cysts are commonly unilocular and may grow to 20cm in size. The cyst wall is thick and has an external laminated hilar membrane and an internal enucleated germinal layer Typically presents with malaise and right upper quadrant pain. Secondary bacterial infection occurs in 10%. Liver function tests are usually abnormal and eosinophilia is present in 33% cases Ultrasound may show septa and hyatid sand or daughter cysts. Percutaneous aspiration was previously contra indicated, it is now incorporated into some treatment regimens Treatment is by sterilisation of the cyst with mebendazole and may be followed by surgical resection. Hypertonic swabs are packed around the cysts during surgery Polycystic liver disease Usually occurs in association with polycystic kidney disease Autosomal dominant disorder Symptoms may occur as a result of capsular stretch Cystadenoma Rare lesions with malignant potential Usually solitary multiloculated lesions Liver function tests usually normal Ultrasonography typically shows a large anechoic, fluid filled area with irregular margins. Internal echos may result from septa Surgical resection is indicated in all cases

Answer 1073

The child is most likely to have a juvenile polyp, these are hamartomatous lesions. Cloacogenic inflammatory polyps correspond to a rare subtype of prolapsing mucosal polyps that arise around the anal transitional zone. They can rarely mimic neoplasia. Adenomatous lesions are rarely seen in children. Lower GI polyps Colonic polyps are a common condition and there are a number of different types. The type of polyps found varies according to the age of the patient and the aetiology of the polyp. Isolated, small proximal polyps are often an incidental. Multiple, distal or large polyps may give rise to symptoms such as bleeding, intussceception or systemic disturbance owing to electrolyte derangement. Polyp types Type Key features Management Juvenile polyp Often single hamartomatous lesions Rectum commonest site Multiple lesions associated with increased risk of malignancy Excision (usually per anal or endoscopic) Hyperplastic polyps Account for 90% of all polyps Usually less than 5mm in diameter Rectosigmoid is commonest location If multiple polyps (more than 20) increased risk of malignancy Isolated hyperplastic polyps are benign and can be left Peutz-Jeghers syndrome Hamartomatous polyps Mucocutaneous hyperpigmentation Family history (autosomal dominant) Polyps benign but may intusscecept Surveillance as increased risk of malignancy Adenoma Comprise around 10% of all colonic polyps 90% less than 1cm in diameter Increased risk of malignancy in those over 1cm in diameter 3 types villous, tubulovillous and tubular Serrated adenomas are a combination of adenomatous and hyperplastic features and are also associated with increased risk of malignancy Full colonoscopic evaluation Colonoscopic polypectomy Follow up depending upon polyp burden and risk factors Inflammatory pseudopolyp Found in patients with IBD Co-existing inflammation is present Management directed at underlying cause Polyposis syndromes Syndrome Genetic defect Features Screening and management Associated disorders Familial adenomatous polyposis Mutation of APC gene (80%) cases, dominant Typically over 100 colonic adenomas Cancer risk of 100% 20% are new mutations If known to be at risk then predictive genetic testing as teenager Annual flexible sigmoidoscopy from 15 years If no polyps found then 5 yearly colonoscopy started at age 20 Polyps found = resectional surgery (resection and pouch Vs sub total colectomy and IRA) Gastric fundal polyps (50%). Duodenal polyps 90%. If severe duodenal polyposis cancer risk of 30% at 10 years. Abdominal desmoid tumours MYH associated polyposis Biallelic mutation of mut Y human homologue (MYH) on chromosome 1p, recessive Multiple colonic polyps Later onset right sided cancers more common than in FAP 100% cancer risk by age 60 Once identified resection and ileoanal pouch reconstruction is recommended Attenuated phenotype - regular colonoscopy Duodenal polyposis in 30% Associated with increased risk of breast cancer (self examination) Peutz -Jeghers syndrome STK11 (LKB1) mutation on chromosome 19 in some (but not all) cases, dominant Multiple benign intestinal hamartomas Episodic obstruction and intussceception Increased risk of GI cancers (colorectal cancer 20%, gastric 5%) Increased risk of breast, ovarian, cervical pancreatic and testicular cancers Annual examination Pan intestinal endoscopy every 2-3 years Malignancies at other sites Classical pigmentation pattern Cowden disease Mutation of PTEN gene on chromosome 10q22, dominant Macrocephaly Multiple intestinal hamartomas Multiple trichilemmomas 89% risk of cancer at any site 16% risk of colorectal cancer Targeted individualised screening Breast cancer (81% risk) Thyroid cancer and non toxic goitre Uterine cancer HNPCC (Lynch syndrome) Germline mutations of DNA mismatch repair genes Colo rectal cancer 30-70% Endometrial cancer 30-70% Gastric cancer 5-10% Scanty colonic polyps may be present Colonic tumours likely to be right sided and mucinous Colonoscopy every 1-2 years from age 25 Consideration of prophylactic surgery Extra colonic surveillance recommended Extra colonic cancers

Answer 1074

A T Test is most suited to data which follows the normal distribution as the others are non parametric tests. The Bonferroni test is used to provide correction when multiple tests are used. Qualitative and quantitative data Qualitative and quantitative data Qualitative (categorical) data refers to different descriptions of a characteristic, although it may be possible to allocate a number it has no scale. Quantitative data is associated with numerical values on a numerical scale. Since quantitative data is based on a numerical scale it can be organised to create a distribution curve. The central tendency may be estimated using the mode, median and mean. The standard deviation gives an estimation of the spread of data.

Answer 1075

There are three unpaired branches to the abdominal viscera. These include the coeliac axis, the SMA and IMA. Branches to the adrenals, renal arteries and gonadal vessels are paired. The fourth unpaired branch of the abdominal aorta, the median sacral artery, does not directly supply the abdominal viscera. Abdominal aortic branches Branches Level Paired Type Inferior phrenic T12 (Upper border) Yes Parietal Coeliac T12 No Visceral Superior mesenteric L1 No Visceral Middle suprarenal L1 Yes Visceral Renal L1-L2 Yes Visceral Gonadal L2 Yes Visceral Lumbar L1-L4 Yes Parietal Inferior mesenteric L3 No Visceral Median sacral L4 No Parietal Common iliac L4 Yes Terminal

Answer 1076

When a diagnosis of lymphoma is suspected, the correct investigation is excision biopsy of a complete lymph node to confirm the diagnosis. Excision of a single node is appropriate. Lymphoma is usually treated with chemotherapy and axillary node clearance is therefore inappropriate. FNA and core biopsy will not allow accurate diagnosis and are therefore not appropriate. Hodgkins lymphoma Presenting features Asymptomatic lympadenopathy Cough, Pel Ebstein fever, haemoptysis, dyspnoea B Symptoms - 10% weight loss, fever, night sweats Staging All patients are staged with CT scanning of the chest, abdomen and pelvis The Ann Arbor staging system is commonly used Stage Features I Single lymph node region II Two or more regions on the same side of the diaphragm III Involvement of lymph node regions on both sides of the diaphragm IV Involvement of extra nodal sites Sub types Classical Hodgkin lymphoma is classified into the following 4 types: Nodular sclerosing Hodgkin lymphoma (NSHL) Mixed-cellularity Hodgkin lymphoma (MCHL) Lymphocyte-depleted Hodgkin lymphoma (LDHL) Lymphocyte-rich classical Hodgkin lymphoma (LRHL) Reed Sternberg cells may be identified histologically. Treatment This may be multimodal and both chemo and radiotherapy are used. Diagnosis This is made by excision of a complete lymph node that is then submitted for detailed histological evaluation. Pathogenesis Infection with Ebstein Barr virus is linked to the condition (particularly mixed cellularity lymphoma). Prognosis Stage I disease is associated with survival figures of up to 85% at 5 years. Nodular sclerosing has the best prognosis. Lymphocyte depleted Hodgkins lymphoma, advancing age, male sex and stage IV disease are all associated with a worsening of prognosis. Reference Shanbhag S and Ambinder R. Hodgkin Lymphoma: a review and update on recent progress. CA Cancer J Clin . 2018 March ; 68(2): 116132

Answer 1077

Mnemonic for radial nerve muscles: BEST B rachioradialis E xtensors S upinator T riceps Abductor digiti minimi is innervated by the ulnar nerve. Radial nerve Continuation of posterior cord of the brachial plexus (root values C5 to T1) Path In the axilla: lies posterior to the axillary artery on subscapularis, latissimus dorsi and teres major. Enters the arm between the brachial artery and the long head of triceps (medial to humerus). Spirals around the posterior surface of the humerus in the groove for the radial nerve. At the distal third of the lateral border of the humerus it then pierces the intermuscular septum and descends in front of the lateral epicondyle. At the lateral epicondyle it lies deeply between brachialis and brachioradialis where it then divides into a superficial and deep terminal branch. Deep branch crosses the supinator to become the posterior interosseous nerve. Regions innervated Motor (main nerve) Triceps Anconeus Brachioradialis Extensor carpi radialis Motor (posterior interosseous branch) Supinator Extensor carpi ulnaris Extensor digitorum Extensor indicis Extensor digiti minimi Extensor pollicis longus and brevis Abductor pollicis longus Sensory The area of skin supplying the proximal phalanges on the dorsal aspect of the hand is supplied by the radial nerve (this does not apply to the little finger and part of the ring finger) Muscular innervation and effect of denervation Anatomical location Muscle affected Effect of paralysis Shoulder Long head of triceps Minor effects on shoulder stability in abduction Arm Triceps Loss of elbow extension Forearm Supinator Brachioradialis Extensor carpi radialis longus and brevis Weakening of supination of prone hand and elbow flexion in mid prone position

Answer 1078

Jugular venous pressure Absent a waves = Atrial fibrillation Large a waves = Any cause of right ventricular hypertrophy, tricuspid stenosis Cannon waves (extra large a waves) = Complete heart block Prominent v waves = Tricuspid regurgitation Slow y descent = Tricuspid stenosis, right atrial myxoma Steep y descent = Right ventricular failure, constrictive pericarditis, tricuspid regurgitation This patient has atrial fibrillation and is most likely to have absent a waves. Jugular venous pressure As well as providing information on right atrial pressure, the jugular vein waveform may provide clues to underlying valvular disease. A non-pulsatile JVP is seen in superior vena caval obstruction. Kussmaul's sign describes a paradoxical rise in JVP during inspiration seen in constrictive pericarditis 'a' wave = atrial contraction large if atrial pressure e.g. tricuspid stenosis, pulmonary stenosis, pulmonary hypertension absent if in atrial fibrillation Cannon 'a' waves caused by atrial contractions against a closed tricuspid valve are seen in complete heart block, ventricular tachycardia/ectopics, nodal rhythm, single chamber ventricular pacing 'c' wave closure of tricuspid valve not normally visible 'v' wave due to passive filling of blood into the atrium against a closed tricuspid valve giant v waves in tricuspid regurgitation 'x' descent = fall in atrial pressure during ventricular systole 'y' descent = opening of tricuspid valve

Answer 1079

The MRSA would or may be resistant to Other antibiotics. Rifampicin is normally given in combination with another antibiotic. MRSA Methicillin-resistant Staphylococcus aureus (MRSA) was one of the first organisms which highlighted the dangers of hospital-acquired infections. Who should be screened for MRSA? all patients awaiting elective admissions (exceptions include day patients having terminations of pregnancy and ophthalmic surgery. Patients admitted to mental health trusts are also excluded) in the UK all emergency admissions are currently screened How should a patient be screened for MRSA? nasal swab and skin lesions or wounds the swab should be wiped around the inside rim of a patient's nose for 5 seconds the microbiology form must be labelled 'MRSA screen' Suppression of MRSA from a carrier once identified nose: mupirocin 2% in white soft paraffin, tds for 5 days skin: chlorhexidine gluconate, od for 5 days. Apply all over but particularly to the axilla, groin and perineum The following antibiotics are commonly used in the treatment of MRSA infections: vancomycin teicoplanin Some strains may be sensitive to the antibiotics listed below but they should not generally be used alone because resistance may develop: rifampicin macrolides tetracyclines aminoglycosides clindamycin Relatively new antibiotics such as linezolid, quinupristin/dalfopristin combinations and tigecycline have activity against MRSA but should be reserved for resistant cases

Answer 1080

The lingual nerve wraps around Whartons duct. The lingual nerve provides sensory supply to the anterior 2/3 of the tongue. Submandibular gland Relations of the submandibular gland Superficial Platysma, deep fascia and mandible Submandibular lymph nodes Facial vein (facial artery near mandible) Marginal mandibular nerve Cervical branch of the facial nerve Deep Facial artery (inferior to the mandible) Mylohyoid muscle Sub mandibular duct Hyoglossus muscle Lingual nerve Submandibular ganglion Hypoglossal nerve Submandibular duct (Wharton's duct) Opens lateral to the lingual frenulum on the anterior floor of mouth. 5 cm length Lingual nerve wraps around Wharton's duct. As the duct passes forwards it crosses medial to the nerve to lie above it and then crosses back, lateral to it, to reach a position below the nerve. Innervation Sympathetic innervation- Derived from superior cervical ganglion Parasympathetic innervation- Submandibular ganglion via lingual nerve Arterial supply Branch of the facial artery. The facial artery passes through the gland to groove its deep surface. It then emerges onto the face by passing between the gland and the mandible. Venous drainage Anterior facial vein (lies deep to the Marginal Mandibular nerve) Lymphatic drainage Deep cervical and jugular chains of nodes

Answer 1081

The history of blood stained discharge and tenderness makes an ectopic pregnancy a strong possibility, a USS should be performed and a pregnancy test undertaken. If the beta HCG is high then an intra uterine pregnancy should be found. If it is not, then an ectopic pregnancy is likely and surgery should be considered. Right iliac fossa pain Differential diagnosis Appendicitis Pain radiating to right iliac fossa Anorexia (very common) Short history Diarrhoea and profuse vomiting rare Crohn's disease Often long history Signs of malnutrition Change in bowel habit, especially diarrhoea Mesenteric adenitis Mainly affects children Causes include Adenoviruses, Epstein Barr Virus, beta-haemolytic Streptococcus, Staphylococcus spp., Escherichia coli, Streptococcus viridans and Yersinia spp. Patients have a higher temperature than those with appendicitis If laparotomy is performed, enlarged mesenteric lymph nodes will be present Diverticulitis Both left and right sided disease may present with right iliac fossa pain Clinical history may be similar, although some change in bowel habit is usual When suspected, a CT scan may help in refining the diagnosis Meckel's diverticulitis A Meckel's diverticulum is a congenital abnormality that is present in about 2% of the population Typically 2 feet proximal to the ileocaecal valve May be lined by ectopic gastric mucosal tissue and produce bleeding Perforated peptic ulcer This usually produces upper quadrant pain but pain may be lower Perforations typically have a sharp sudden onset of pain in the history Incarcerated right inguinal or femoral hernia Usually only right iliac fossa pain if right sided or bowel obstruction. Bowel perforation secondary to caecal or colon carcinoma Seldom localised to right iliac fossa, although complete large bowel obstruction with caecal distension may cause pain prior to perforation. Gynaecological causes Pelvic inflammatory disease/salpingitis/pelvic abscess/Ectopic pregnancy/Ovarian torsion/Threatened or complete abortion/Mittelschmerz Urological causes Ureteric colic/UTI/Testicular torsion Other causes TB/Typhoid/Herpes Zoster/AAA/Situs inversus

Answer 1082

Sarcoid occurs bilaterally in 70% of cases and facial nerve involvement is recognised. Treatment is conservative in most cases although individuals with facial nerve palsy will usually receive steroids with good effect. Parotid gland clinical Benign neoplasms Up to 80% of all salivary gland tumours occur in the parotid gland and up to 80% of these are benign. There is no consistent correlation between the rate of growth and the malignant potential of the lesion. However, benign tumours should not invade structures such as the facial nerve. With the exception of Warthins tumours, they are commoner in women than men. The median age of developing a lesion is in the 5th decade of life. Benign tumour types Tumour type Features Benign pleomorphic adenoma or benign mixed tumor Most common parotid neoplasm (80%) Proliferation of epithelial and myoepithelial cells of the ducts and an increase in stromal components Slow growing, lobular, and not well encapsulated Recurrence rate of 1-5% with appropriate excision (parotidectomy) Recurrence possibly secondary to capsular disruption during surgery Malignant degeneration occurring in 2-10% of adenomas observed for long periods, with carcinoma ex-pleomorphic adenoma occurring most frequently as adenocarcinoma Warthin tumor (papillary cystadenoma lymphoma or adenolymphoma) Second most common benign parotid tumor (5%) Most common bilateral benign neoplasm of the parotid Marked male as compared to female predominance Occurs later in life (sixth and seventh decades) Presents as a lymphocytic infiltrate and cystic epithelial proliferation May represent heterotopic salivary gland epithelial tissue trapped within intraparotid lymph nodes Incidence of bilaterality and multicentricity of 10% Malignant transformation rare (almost unheard of) Monomorphic adenoma Account for less than 5% of tumours Slow growing Consist of only one morphological cell type (hence term mono) Include; basal cell adenoma, canalicular adenoma, oncocytoma, myoepitheliomas Haemangioma Should be considered in the differential of a parotid mass in a child Accounts for 90% of parotid tumours in children less than 1 year of age Hypervascular on imaging Spontaneous regression may occur and malignant transformation is almost unheard of Malignant salivary gland tumours Types of malignancy Mucoepidermoid carcinoma 30% of all parotid malignancies Usually low potential for local invasiveness and metastasis (depends mainly on grade) Adenoid cystic carcinoma Unpredictable growth pattern Tendency for perineural spread Nerve growth may display skip lesions resulting in incomplete excision Distant metastasis more common (visceral rather than nodal spread) 5 year survival 35% Mixed tumours Often a malignancy occurring in a previously benign parotid lesion Acinic cell carcinoma Intermediate grade malignancy May show perineural invasion Low potential for distant metastasis 5 year survival 80% Adenocarcinoma Develops from secretory portion of gland Risk of regional nodal and distant metastasis 5 year survival depends upon stage at presentation, may be up to 75% with small lesions with no nodal involvement Lymphoma Large rubbery lesion, may occur in association with Warthins tumours Diagnosis should be based on regional nodal biopsy rather than parotid resection Treatment is with chemotherapy (and radiotherapy) Diagnostic evaluation Plain x-rays may be used to exclude calculi Sialography may be used to delineate ductal anatomy FNAC is used in most cases Superficial parotidectomy may be either diagnostic or therapeutic depending upon the nature of the lesion Where malignancy is suspected the primary approach should be definitive resection rather than excisional biopsy CT/ MRI may be used in cases of malignancy for staging primary disease Treatment For nearly all lesions this consists of surgical resection, for benign disease this will usually consist of a superficial parotidectomy. For malignant disease a radical or extended radical parotidectomy is performed. The facial nerve is included in the resection if involved. The need for neck dissection is determined by the potential for nodal involvement. Other parotid disorders HIV infection Lymphoepithelial cysts associated with HIV occur almost exclusively in the parotid Typically presents as bilateral, multicystic, symmetrical swelling Risk of malignant transformation is low and management usually conservative Sjogren syndrome Autoimmune disorder characterised by parotid enlargement, xerostomia and keratoconjunctivitis sicca 90% of cases occur in females Second most common connective tissue disorder Bilateral, non tender enlargement of the gland is usual Histologically, the usual findings are of a lymphocytic infiltrate in acinar units and epimyoepithelial islands surrounded by lymphoid stroma Treatment is supportive There is an increased risk of subsequent lymphoma Sarcoid Parotid involvement occurs in 6% of patients with sarcoid Bilateral in most cases Gland is not tender Xerostomia may occur Management of isolated parotid disease is usually conservative

Answer 1083

The common peroneal nerve bifurcates at the neck of the fibula (where it is most likely to be injured). Common peroneal nerve Derived from the dorsal divisions of the sacral plexus (L4, L5, S1 and S2). This nerve supplies the skin and fascia of the anterolateral surface of the leg and the dorsum of the foot. It also innervates the muscles of the anterior and peroneal compartments of the leg, extensor digitorum brevis as well as the knee, ankle and foot joints. It is laterally placed within the sciatic nerve. From the bifurcation of the sciatic nerve it passes inferolaterally in the lateral and proximal part of the popliteal fossa, under the cover of biceps femoris and its tendon. To reach the posterior aspect of the fibular head. It ends by dividing into the deep and superficial peroneal nerves at the point where it winds around the lateral surface of the neck of the fibula in the body of peroneus longus, approximately 2cm distal to the apex of the head of the fibula. It is palpable posterior to the head of the fibula. Branches In the thigh Nerve to the short head of biceps Articular branch (knee) In the popliteal fossa Lateral cutaneous nerve of the calf Neck of fibula Superficial and deep peroneal nerves

Answer 1084

The cell saver is inappropriate because the cells will be contaminated with malignant cells and faecal matter from the open bowel. Blood products Whole blood fractions Fraction Key points Packed red cells Used for transfusion in chronic anaemia and cases where infusion of large volumes of fluid may result in cardiovascular compromise. Product obtained by centrifugation of whole blood. Platelet rich plasma Usually administered to patients who are thrombocytopaenic and are bleeding or require surgery. It is obtained by low speed centrifugation. Platelet concentrate Prepared by high speed centrifugation and administered to patients with thrombocytopaenia. Fresh frozen plasma Prepared from single units of blood. Contains clotting factors, albumin and immunoglobulin. Unit is usually 200 to 250ml. Usually used in correcting clotting deficiencies in patients with hepatic synthetic failure who are due to undergo surgery. Usual dose is 12-15ml/Kg-1. It should not be used as first line therapy for hypovolaemia. Cryoprecipitate Formed from supernatant of FFP. Rich source of Factor VIII and fibrinogen. Allows large concentration of factor VIII to be administered in small volume. SAG-Mannitol Blood Removal of all plasma from a blood unit and substitution with: Sodium chloride Adenine Anhydrous glucose Mannitol Up to 4 units of SAG M Blood may be administered. Thereafter whole blood is preferred. After 8 units, clotting factors and platelets should be considered. Cell saver devices These collect patients own blood lost during surgery and then re-infuse it. There are two main types: Those which wash the blood cells prior to re-infusion. These are more expensive to purchase and more complicated to operate. However, they reduce the risk of re-infusing contaminated blood back into the patient. Those which do not wash the blood prior to re-infusion. Their main advantage is that they avoid the use of infusion of blood from donors into patients and this may reduce risk of blood borne infection. It may be acceptable to Jehovah's witnesses. It is contraindicated in malignant disease for risk of facilitating disease dissemination. Blood products used in warfarin reversal In some surgical patients the use of warfarin can pose specific problems and may require the use of specialised blood products Immediate or urgent surgery in patients taking warfarin(1) (2): 1. Stop warfarin 2. Vitamin K (reversal within 4-24 hours) -IV takes 4-6h to work (at least 5mg) -Oral can take 24 hours to be clinically effective 3. Fresh frozen plasma Used less commonly now as 1st line warfarin reversal -30ml/kg-1 -Need to give at least 1L fluid in 70kg person (therefore not appropriate in fluid overload) -Need blood group -Only use if human prothrombin complex is not available 4. Human Prothrombin Complex (reversal within 1 hour) -Bereplex 50 u/kg -Rapid action but factor 6 short half life, therefore give with vitamin K References 1. Dentali, F., C. Marchesi, et al. (2011). 'Safety of prothrombin complex concentrates for rapid anticoagulation reversal of vitamin K antagonists. A meta-analysis.' Thromb Haemost 106(3): 429-438. 2. http://www.transfusionguidelines.org/docs/pdfs/bbt-03warfarin-reversal-flowchart-2006.pdf

Answer 1085

Synchronous colonic tumours are seen in 5% cases and all patients having a flexible sigmoidoscopy should have completion colonoscopy if tumours or polyps are found Synchronous lesions may occur in up to 5% of patients with colorectal cancer. A full and complete lumenal study with either colonoscopy, CT cologram or barium enema is mandatory in all patients being considered for surgery. Colorectal cancer Annually, about 150,000 new cases are diagnosed and 50,000 deaths from the disease About 75% will have sporadic disease and 25% will have a family history Colorectal tumours comprise a spectrum of disease ranging from adenomas through to polyp cancers and frank malignancy. Polyps may be categorised into: neoplastic polyps, adenomatous polyps and non neoplastic polyps. The majority of adenomas are polypoidal lesions, although flat lesions do occur and may prove to be dysplastic. Non-neoplastic polyps include hyperplastic, juvenile, hamartomatous, inflammatory, and lymphoid polyps, which have not generally been thought of as precursors of cancer. Three characteristics of adenomas that correlate with malignant potential have been characterised. These include increased size, villous architecture and dysplasia. For this reason most polyps identified at colonoscopy should be removed. The transformation from polyp to cancer is described by the adenoma - carcinoma sequence and its principles should be appreciated. Essentially genetic changes accompany the transition from adenoma to carcinoma; key changes include APC, c-myc, K RAS mutations and p53 deletions.

Answer 1086

Most gastric malignancies are adenocarcinomas. Gastric cancer Overview There are 700,000 new cases of gastric cancer worldwide each year. It is most common in Japan and less common in western countries. It is more common in men and incidence rises with increasing age. The exact cause of many sporadic cancer is not known, however, familial cases do occur in HNPCC families. In addition, smoking and smoked or preserved foods increase the risk. Japanese migrants retain their increased risk (decreased in subsequent generations). The distribution of the disease in western countries is changing towards a more proximal location (perhaps due to rising obesity). Pathology There is some evidence of support a stepwise progression of the disease through intestinal metaplasia progressing to atrophic gastritis and subsequent dysplasia, through to cancer. The favoured staging system is TNM. The risk of lymph node involvement is related to size and depth of invasion; early cancers confined to submucosa have a 20% incidence of lymph node metastasis. Tumours of the gastro-oesophageal junction are classified as below: Type 1 True oesophageal cancers and may be associated with Barrett's oesophagus. Type 2 Carcinoma of the cardia, arising from cardiac type epithelium or short segments with intestinal metaplasia at the oesophagogastric junction. Type 3 Sub cardial cancers that spread across the junction. Involve similar nodal stations to gastric cancer. Groups for close endoscopic monitoring Intestinal metaplasia of columnar type Atrophic gastritis Low to medium grade dysplasia Patients who have previously undergone resections for benign peptic ulcer disease (except highly selective vagotomy). Referral to endoscopy Patients of any age with dyspepsia and any of the following Patients without dyspepsia Worsening dyspepsia Chronic gastrointestinal bleeding Dysphagia Barretts oesophagus Dysphagia Unexplained abdominal pain or weight loss Intestinal metaplasia Weight loss Vomiting Dysplasia Iron deficiency anaemia Upper abdominal mass Atrophic gastritis Upper abdominal mass Jaundice Patient aged over 55 years with unexplained or persistent dyspepsia Staging CT scanning of the chest abdomen and pelvis is the routine first line staging investigation in most centres. Laparoscopy to identify occult peritoneal disease PET CT (particularly for junctional tumours) Treatment Proximally sited disease greater than 5-10cm from the OG junction may be treated by sub total gastrectomy Total gastrectomy if tumour is <5cm from OG junction For type 2 junctional tumours (extending into oesophagus) oesophagogastrectomy is usual Endoscopic sub mucosal resection may play a role in early gastric cancer confined to the mucosa and perhaps the sub mucosa (this is debated) Lymphadenectomy should be performed. A D2 lymphadenectomy is widely advocated by the Japanese, the survival advantages of extended lymphadenectomy have been debated. However, the overall recommendation is that a D2 nodal dissection be undertaken. Most patients will receive chemotherapy either pre or post operatively. Prognosis UK Data Disease extent Percentage 5 year survival All RO resections 54% Early gastric cancer 91% Stage 1 87% Stage 2 65% Stage 3 18% Operative procedure Total Gastrectomy , lymphadenectomy and Roux en Y anastomosis General anaesthesia Prophylactic intravenous antibiotics Incision: Rooftop. Perform a thorough laparotomy to identify any occult disease. Mobilise the left lobe of the liver off the diaphragm and place a large pack over it. Insert a large self retaining retractor e.g. omnitract or Balfour (take time with this, the set up should be perfect). Pack the small bowel away. Begin by mobilising the omentum off the transverse colon. Proceed to detach the short gastric vessels. Mobilise the pylorus and divide it at least 2cm distally using a linear cutter stapling device. Continue the dissection into the lesser sac taking the lesser omentum and left gastric artery flush at its origin. The lymph nodes should be removed en bloc with the specimen where possible. Place 2 stay sutures either side of the distal oesophagus. Ask the anaesthetist to pull back on the nasogastric tube. Divide the distal oesophagus and remove the stomach. The oesphago jejunal anastomosis should be constructed. Identify the DJ flexure and bring a loop of jejunum up to the oesophagus (to check it will reach). Divide the jejunum at this point. Bring the divided jejunum either retrocolic or antecolic to the oesophagus. Anastamose the oesophagus to the jejunum, using either interrupted 3/0 vicryl or a stapling device. Then create the remainder of the Roux en Y reconstruction distally. Place a jejunostomy feeding tube. Wash out the abdomen and insert drains (usually the anastomosis and duodenal stump). Help the anaesthetist insert the nasogastric tube (carefully!) Close the abdomen and skin. Enteral feeding may commence on the first post-operative day. However, most surgeons will leave patients on free NG drainage for several days and keep them nil by mouth.

Answer 1087

The absence of fibrosis coupled with small size suggests a more acute ulcer. Management should include biopsy, PPI and repeat endoscopy at 6 weeks. Upper gastrointestinal bleeding Patients may present with the following: Haematemesis and/ or malaena Epigastric discomfort Sudden collapse The extent to which these will occur will depend upon the source. Mortality is higher in patients presenting with haematemesis than malaena alone. Oesophageal bleeding Cause Presenting features Oesophagitis Small volume of fresh blood, often streaking vomit. Malaena rare. Often ceases spontaneously. Usually history of antecedent GORD type symptoms. Cancer Usually small volume of blood, except as pre terminal event with erosion of major vessels. Often associated symptoms of dysphagia and constitutional symptoms such as weight loss. May be recurrent until malignancy managed. Mallory Weiss Tear Typically brisk small to moderate volume of bright red blood following bout of repeated vomiting. Malaena rare. Usually ceases spontaneously. Varices Usually large volume of fresh blood. Swallowed blood may cause malaena. Often associated with haemodynamic compromise. May stop spontaneously but re-bleeds are common until appropriately managed. Gastric Bleeding Cause Presenting features Gastric cancer May be frank haematemesis or altered blood mixed with vomit. Usually prodromal features of dyspepsia and may have constitutional symptoms. Amount of bleeding variable but erosion of major vessel may produce considerable haemorrhage. Dieulafoy Lesion Often no prodromal features prior to haematemesis and malaena, but this arteriovenous malformation may produce quite considerable haemorrhage and may be difficult to detect endoscopically. Diffuse erosive gastritis Usually haematemesis and epigastric discomfort. Usually there is an underlying cause such as recent NSAID usage. Large volume haemorrhage may occur with considerable haemodynamic compromise. Gastric ulcer Small low volume bleeds more common so would tend to present as iron deficiency anaemia. Erosion into a significant vessel may produce considerable haemorrhage and haematemesis. Duodenum Most common cause of major haemorrhage is a posteriorly sited duodenal ulcer. However, ulcers at any site in the duodenum may present with haematemesis, malaena and epigastric discomfort. The pain of duodenal ulcer is slightly different to that of gastric ulcers and often occurs several hours after eating. Peri ampullary tumours may bleed but these are rare. In patients with previous abdominal aortic aneurysm surgery aorto-enteric fistulation remains a rare but important cause of major haemorrhage associated with high mortality. Management Admission to hospital careful monitoring, cross match blood, check FBC, LFTs, U+E and Clotting (as a minimum) Patients with on-going bleeding and haemodynamic instability are likely to require O negative blood pending cross matched blood Early control of airway is vital (e.g. Drowsy patient with liver failure) Patients with suspected varices should receive terlipressin prior to endoscopy Ideally all patients admitted with upper gastrointestinal haemorrhage should undergo Upper GI endoscopy within 24 hours of admission. In those who are unstable this should occur immediately after resuscitation or in tandem with it. The endoscopy department is a potentially dangerous place for unstable patients and it may be safer to perform the endoscopy in theatre with an anaesthetist present. Varices should be banded or subjected to sclerotherapy. If this is not possible owing to active bleeding then a Sengstaken- Blakemore tube (or Minnesota tube) should be inserted. This should be done with care; gastric balloon should be inflated first and oesophageal balloon second. Remember the balloon will need deflating after 12 hours (ideally sooner) to prevent necrosis. Portal pressure should be lowered by combination of medical therapy +/- TIPSS. Patients with erosive oesophagitis / gastritis should receive a proton pump inhibitor. Mallory Weiss tears will typically resolve spontaneously Identifiable bleeding points should receive combination therapy of injection of adrenaline and either a thermal or mechanical treatment. All who have received intervention should receive a continuous infusion of a proton pump inhibitor (IV omeprazole for 72 hours) to reduce the re-bleeding rate. Patients with diffuse erosive gastritis who cannot be managed endoscopically and continue to bleed may require gastrectomy Bleeding ulcers that cannot be controlled endoscopically may require laparotomy and ulcer underruning Indications for surgery Patients > 60 years Continued bleeding despite endoscopic intervention Recurrent bleeding Known cardiovascular disease with poor response to hypotension Surgery Duodenal ulcer Laparotomy, duodenotomy and under running of the ulcer. If bleeding is brisk then the ulcer is almost always posteriorly sited and will have invaded the gastroduodenal artery. Large bites using 0 Vicryl are taken above and below the ulcer base to occlude the vessel. The duodenotomy should be longitudinal but closed transversely to avoid stenosis. For gastric ulcer Under-running of the bleeding site Partial gastrectomy-antral ulcer Partial gastrectomy or under running the ulcer- lesser curve ulcer (involving left gastric artery) Total gastrectomy if bleeding persists Summary of Acute Upper GI bleeding recommendations: The need for admission and timing of endoscopic intervention may be predicted by using the Blatchford score. This considers a patients Hb, serum urea, pulse rate and blood pressure. Those patients with a score of 0 are low risk, all others are considered high risk and require admission and endoscopy. The requirement for pre endoscopic proton pump inhibition is contentious. In the UK the National Institute of Clinical Excellence guidelines suggest the pre endoscopic PPI therapy is unnecessary. Whilst it is accepted that such treatment has no impact on mortality or morbidity a Cochrane review of this practice in 2007 did suggest that it reduced the stigmata of recent haemorrhage at endoscopy. As a result many will still administer PPI to patients prior to endoscopic intervention. Following endoscopy it is important to calculate the Rockall score for patients to determine their risk of rebleeding and mortality. A score of 3 or less is associated with a rebleeding rate of 4% and a very low risk of mortality and identifies a group of patients suitable for early discharge. References 1. http://www.sign.ac.uk/guidelines/fulltext/105/index.html 2. Joint Advisory Group on Endoscopy (JAG) Guidelines - http://www.thejag.org.uk 3. NICE Guideline: Management of acute upper GI bleeding. July 2012.

Answer 1088

The aorta bifurcates at L4. An important landmark that is tested frequently. Abdominal aorta Abdominal aortic topography Origin T12 Termination L4 Posterior relations L1-L4 Vertebral bodies Anterior relations Lesser omentum Liver Left renal vein Inferior mesenteric vein Third part of duodenum Pancreas Parietal peritoneum Peritoneal cavity Right lateral relations Right crus of the diaphragm Cisterna chyli IVC (becomes posterior distally) Left lateral relations 4th part of duodenum Duodenal-jejunal flexure Left sympathetic trunk

Answer 1089

The presence of distant disease in the context of oesophageal cancer renders him incurable. Further staging is not needed and surgery is not an option. Palliation is the preferred option and a metallic stent will achieve this. Treatment of oesophageal cancer - In general resections are not offered to those patients with distant metastasis, and usually not to those with N2 disease. Local nodal involvement is not in itself a contra indication to resection. Surgical resection is the mainstay of treatment. Neoadjuvent chemotherapy is given in most cases prior to surgery. In situ disease may be managed by endoscopic mucosal resection, although this is still debated. In patients with lower third lesions an Ivor - Lewis type procedure is most commonly performed. Very distal tumours may be suitable to a transhiatal procedure. Which is an attractive option as the penetration of two visceral cavities required for an Ivor- Lewis type procedure increases the morbidity considerably. More proximal lesions will require a total oesphagectomy (Mckeown type) with anastomosis to the cervical oesophagus. Patients with unresectable disease may derive benefit from local ablative procedures, palliative chemotherapy or stent insertion. Operative details of Ivor- Lewis procedure Combined laparotomy and right thoracotomy Indication Lower and middle third oesophageal tumours Preparation Staging with a combination of CT chest abdomen and pelvis- if no metastatic disease detected then patients will undergo a staging laparoscopy to detect peritoneal disease. If both these modalities are negative then patients will finally undergo a PET CT scan to detect occult metastatic disease. Only in those whom no evidence of advanced disease is detected will proceed to resection. Patients receive a GA, double lumen endotracheal tube to allow for lung deflation, CVP and arterial monitoring. Procedure A rooftop incision is made to access the stomach and duodenum. Laparotomy To mobilize the stomach The greater omentum is incised away from its attachment to the right gastroepiploic vessels along the greater curvature of the stomach. Then the short gastric vessels are ligated and detached from the greater curvature from the spleen. The lesser omentum is incised, preserving the right gastric artery. The retroperitoneal attachments of the duodenum in its second and third portions are incised, allowing the pylorus to reach the oesophageal hiatus. Some surgeons perform a pyloroplasty at this point to facilitate gastric emptying. The left gastric vessels are then ligated, avoiding any injury to the common hepatic or splenic arteries. Care must be taken to avoid inadvertently devascularising the liver owing to variations in anatomy. Right Thoracotomy Oesophageal resection and oesophagogastric anastomosis Through 5th intercostal space Dissection performed 10cm above the tumour This may involve transection of the azygos vein. The oesophagus is then removed with the stomach creating a gastric tube. An anastomosis is created. The chest is closed with underwater seal drainage and tube drains to the abdominal cavity. Post operatively Patients will typically recover in ITU initially. A nasogastric tube will have been inserted intraoperatively and must remain in place during the early phases of recovery. Post operatively these patients are at relatively high risk of developing complications: * Atelectasis- due to the effects of thoracotomy and lung collapse * Anastomotic leakage. The risk is relatively high owing to the presence of a relatively devascularised stomach. Often the only blood supply is from the gastroepiploic artery as all others will have been divided. If a leak does occur then many will attempt to manage conservatively with prolonged nasogastric tube drainage and TPN. The reality is that up to 50% of patients developing an anastomotic leak will not survive to discharge. * Delayed gastric emptying (may be avoided by performing a pyloroplasty).

Answer 1090

Stensens duct conveys secretions from the parotid gland and these enter the oral cavity at the level of the second molar tooth. Parotid gland Anatomy of the parotid gland Location Overlying the mandibular ramus; anterior and inferior to the ear. Salivary duct Crosses the masseter, pierces the buccinator and drains adjacent to the 2nd upper molar tooth (Stensen's duct). Structures passing through the gland Facial nerve (Mnemonic: The Zebra Buggered My Cat; Temporal Zygomatic, Buccal, Mandibular, Cervical) External carotid artery Retromandibular vein Auriculotemporal nerve Relations Anterior: masseter, medial pterygoid, superficial temporal and maxillary artery, facial nerve, stylomandibular ligament Posterior: posterior belly digastric muscle, sternocleidomastoid, stylohyoid, internal carotid artery, mastoid process, styloid process Arterial supply Branches of external carotid artery Venous drainage Retromandibular vein Lymphatic drainage Deep cervical nodes Nerve innervation Parasympathetic-Secretomotor Sympathetic-Superior cervical ganglion Sensory- Greater auricular nerve Parasympathetic stimulation produces a water rich, serous saliva. Sympathetic stimulation leads to the production of a low volume, enzyme-rich saliva.

Answer 1091

Delayed limb re-perfusion = Risk of compartment syndrome Delayed surgery for limb ischaemic carries a risk of re-perfusion injury and compartment syndrome. Where surgery is delayed beyond 6 hours, most surgeons would perform a fasciotomy at the same time as the embolectomy. However, whilst the compartments below the knee are vulnerable, its very rare for this to occur in the thigh and so, as a rule, the thigh is not treated in this manner. Acute limb ischaemia - Thrombosis of a pre-existing site of atherosclerosis is the commonest cause of acute limb ischaemia Acute thrombosis of popliteal aneurysms poses the greatest threat to the limb Sudden occlusion of a large proximal vessel results in the typical appearances of acute limb ischaemia Clinical appearances Less than 6 hours = White leg At 6 -12 hours = Mottled limb with blanching on pressure More than 12-24 hours = Fixed mottling Management of acutely ischaemic leg Clinical picture Treatment White leg with sensorimotor deficit Surgery and embolectomy Dusky leg, mild anaesthesia Angiography Fixed mottling Primary amputation Role of thrombolysis Intra arterial thrombolysis is better than peripheral thrombolysis Mainly indicated in acute on chronic thrombosis Avoid if within 2 months of CVA or 2 weeks of surgery Aspiration of clot may improve success rate if the thrombosis is large Surgery Both groins should be prepared Transverse arteriotomy is easier to close Poor inflow should be managed with iliac trawl- if this fails to improve then consider a femoro-femoral cross over or axillo-femoral cross over. A check angiogram should be performed on table and prior to closure Systemic heparinisation should follow surgery Fasciotomy should be considered if the time between onset and surgery exceeds 6 hours

Answer 1092

Causes: Systemic (DM, Hyperbilirubinaemia, aplastic anaemia) Mechanical (diarrhoea, constipation, anal fissure) Infections (STDs) Dermatological Drugs (quinidine, colchicine) Topical agents Ano rectal disease Haemorrhoids Location: 3, 7, 11 o'clock position Internal or external Treatment: Conservative, Rubber band ligation, Haemorrhoidectomy Fissure in ano Location: midline 6 (posterior midline 90%) and 12 o'clock position. Distal to the dentate line Chronic fissure > 6/52: triad: Ulcer, sentinel pile, enlarged anal papillae Proctitis Causes: Crohn's, ulcerative colitis, Clostridium difficile Ano rectal abscess E.coli, staph aureus Positions: Perianal, Ischiorectal, Pelvirectal, Intersphincteric Anal fistula Usually due to previous ano-rectal abscess Intersphincteric, transsphincteric, suprasphincteric, and extrasphincteric. Goodsalls rule determines location Rectal prolapse Associated with childbirth and rectal intussceception. May be internal or external Pruritus ani Systemic and local causes Anal neoplasm Squamous cell carcinoma commonest unlike adenocarcinoma in rectum Solitary rectal ulcer Associated with chronic straining and constipation. Histology shows mucosal thickening, lamina propria replaced with collagen and smooth muscle (fibromuscular obliteration) Rectal prolapse Common especially in multiparous women. May be internal or external. Internal rectal prolapse can present insidiously. External prolapse can ulcerate and in long term impair continence. Diagnostic work up includes colonoscopy, defecating proctogram, ano rectal manometry studies and if doubt exists an examination under anaesthesia. Treatments for prolapse In the acute setting reduce it (covering it with sugar may reduce swelling. Delormes procedure which excises mucosa and plicates the rectum (high recurrence rates) may be used for external prolapse. Altmeirs procedure which resects the colon via the perineal route has lower recurrence rates but carries the risk of anastamotic leak. Rectopexy is an abdominal procedure in which the rectum is elevated and usually supported at the level of the sacral promontory. Post operative constipation may be reduced by limiting the dissection to the anterior plane (laparoscopic ventral mesh rectopexy). Pruritus ani Extremely common. Check not secondary to altered bowel habits (e.g. Diarrhoea) Associated with underlying diseases such as haemorrhoids. Examine to look for causes such as worms. Proctosigmoidoscopy to identify associated haemorrhoids and exclude cancer. Treatment is largely supportive and patients should avoid using perfumed products around the area. Fissure in ano Typically painful PR bleeding (bright red). Nearly always in the posterior midline. Usually solitary. Treatment Stool softeners. Topical diltiazem (or GTN). If topical treatments fail then botulinum toxin should be injected. If botulinum toxin fails then males should probably undergo lateral internal sphincterotomy. Females who do not respond to botulinum toxin should undergo ano rectal manometry studies and endo anal USS prior to being offered surgery such as sphincterotomy.

Answer 1093

Barton's fractures tend to have intra-articular involvement and dislocation may sometimes be present. Eponymous fractures Colles' fracture (dinner fork deformity) Fall onto extended outstretched hand Classical Colles' fractures have the following 3 features: 1. Transverse fracture of the radius 2. 1 inch proximal to the radio-carpal joint 3. Dorsal displacement and angulation Smith's fracture (reverse Colles' fracture) Volar angulation of distal radius fragment (Garden spade deformity) Caused by falling backwards onto the palm of an outstretched hand or falling with wrists flexed Bennett's fracture Intra-articular fracture of the first carpometacarpal joint Impact on flexed metacarpal, caused by fist fights X-ray: triangular fragment at ulnar base of metacarpal Monteggia's fracture Dislocation of the proximal radioulnar joint in association with an ulna fracture Fall on outstretched hand with forced pronation Needs prompt diagnosis to avoid disability Galeazzi fracture Radial shaft fracture with associated dislocation of the distal radioulnar joint Direct blow Pott's fracture Bimalleolar ankle fracture Forced foot eversion Barton's fracture Distal radius fracture (Colles'/Smith's) with associated radiocarpal dislocation Fall onto extended and pronated wrist Involvement of the joint is a defining feature Holstein Lewis Fracture A HolsteinLewis fracture is a fracture of the distal third of the humerus resulting in entrapment of the radial nerve. The radial nerve is one of the major nerves of the upper limb. It innervates all of the muscles in the extensor compartments of the arm. Conservative treatment includes reduction and use of a functional brace Vascular injury may require open surgery

Answer 1094

The circumflex humeral arteries lie at the surgical neck and is this scenario the posterior circumflex is likely to be injured. The thoracoacromial and transverse scapular arteries lie more superomedially. The posterior circumflex humeral artery is a branch of the axillary artery. Shoulder joint Shallow synovial ball and socket type of joint. It is an inherently unstable joint, but is capable to a wide range of movement. Stability is provided by muscles of the rotator cuff that pass from the scapula to insert in the greater tuberosity (all except sub scapularis-lesser tuberosity). Glenoid labrum Fibrocartilaginous rim attached to the free edge of the glenoid cavity Tendon of the long head of biceps arises from within the joint from the supraglenoid tubercle, and is fused at this point to the labrum. The long head of triceps attaches to the infraglenoid tubercle Fibrous capsule Attaches to the scapula external to the glenoid labrum and to the labrum itself (postero-superiorly) Attaches to the humerus at the level of the anatomical neck superiorly and the surgical neck inferiorly Anteriorly the capsule is in contact with the tendon of subscapularis, superiorly with the supraspinatus tendon, and posteriorly with the tendons of infraspinatus and teres minor. All these blend with the capsule towards their insertion. Two defects in the fibrous capsule; superiorly for the tendon of biceps. Anteriorly there is a defect beneath the subscapularis tendon. The inferior extension of the capsule is closely related to the axillary nerve at the surgical neck and this nerve is at risk in anteroinferior dislocations. It also means that proximally sited osteomyelitis may progress to septic arthritis. Movements and muscles Flexion Anterior part of deltoid Pectoralis major Biceps Coracobrachialis Extension Posterior deltoid Teres major Latissimus dorsi Adduction Pectoralis major Latissimus dorsi Teres major Coracobrachialis Abduction Mid deltoid Supraspinatus Medial rotation Subscapularis Anterior deltoid Teres major Latissimus dorsi Lateral rotation Posterior deltoid Infraspinatus Teres minor Important anatomical relations Anteriorly Brachial plexus Axillary artery and vein Posterior Suprascapular nerve Suprascapular vessels Inferior Axillary nerve Circumflex humeral vessels

Answer 1095

These arterial blood gas results are classically seen in situations where there is metabolic alkalosis such as may occur following prolonged vomiting. Disorders of acid - base balance Disorders of acid- base balance are often covered in the MRCS part A. Metabolic acidosis This is the most common surgical acid - base disorder. Reduction in plasma bicarbonate levels. Two mechanisms: 1. Gain of strong acid (e.g. diabetic ketoacidosis) 2. Loss of base (e.g. from bowel in diarrhoea) - Classified according to the anion gap, this can be calculated by: (Na+ + K+) - (Cl- + HCO3-). - If a question supplies the chloride level then this is often a clue that the anion gap should be calculated. The normal range = 10-18 mmol/L Normal anion gap ( = hyperchloraemic metabolic acidosis) Gastrointestinal bicarbonate loss: diarrhoea, ureterosigmoidostomy, fistula Renal tubular acidosis Drugs: e.g. acetazolamide Ammonium chloride injection Addison's disease Raised anion gap Lactate: shock, hypoxia Ketones: diabetic ketoacidosis, alcohol Urate: renal failure Acid poisoning: salicylates, methanol Metabolic acidosis secondary to high lactate levels may be subdivided into two types: Lactic acidosis type A: (Perfusion disorders e.g.shock, hypoxia, burns) Lactic acidosis type B: (Metabolic e.g. metformin toxicity) Metabolic alkalosis Usually caused by a rise in plasma bicarbonate levels. Rise of bicarbonate above 24 mmol/L will typically result in renal excretion of excess bicarbonate. Caused by a loss of hydrogen ions or a gain of bicarbonate. It is due mainly to problems of the kidney or gastrointestinal tract Causes Vomiting / aspiration (e.g. Peptic ulcer leading to pyloric stenosis, nasogastric suction) Diuretics Liquorice, carbenoxolone Hypokalaemia Primary hyperaldosteronism Cushing's syndrome Bartter's syndrome Congenital adrenal hyperplasia Mechanism of metabolic alkalosis Activation of renin-angiotensin II-aldosterone (RAA) system is a key factor Aldosterone causes reabsorption of Na+ in exchange for H+ in the distal convoluted tubule ECF depletion (vomiting, diuretics) → Na+ and Cl- loss → activation of RAA system → raised aldosterone levels In hypokalaemia, K+ shift from cells → ECF, alkalosis is caused by shift of H+ into cells to maintain neutrality Respiratory acidosis Rise in carbon dioxide levels usually as a result of alveolar hypoventilation Renal compensation may occur leading to Compensated respiratory acidosis Causes COPD Decompensation in other respiratory conditions e.g. Life-threatening asthma / pulmonary oedema Sedative drugs: benzodiazepines, opiate overdose Respiratory alkalosis Hyperventilation resulting in excess loss of carbon dioxide This will result in increasing pH Causes Psychogenic: anxiety leading to hyperventilation Hypoxia causing a subsequent hyperventilation: pulmonary embolism, high altitude Early salicylate poisoning* CNS stimulation: stroke, subarachnoid haemorrhage, encephalitis Pregnancy *Salicylate overdose leads to a mixed respiratory alkalosis and metabolic acidosis. Early stimulation of the respiratory centre leads to a respiratory alkalosis whilst later the direct acid effects of salicylates (combined with acute renal failure) may lead to an acidosis

Answer 1096

Hyperlipidaemia and multiple myeloma are known to cause a pseudohyponatraemia, this is due to raised protein. Hyponatraemia This is commonly tested in the MRCS (despite most surgeons automatically seeking medical advice if this occurs!). The most common cause in surgery is the over administration of 5% dextrose. Hyponatraemia may be caused by water excess or sodium depletion. Causes of pseudohyponatraemia include hyperlipidaemia (increase in serum volume) or a taking blood from a drip arm. Urinary sodium and osmolarity levels aid making a diagnosis. Classification Urinary sodium > 20 mmol/l Sodium depletion, renal loss Patient often hypovolaemic Diuretics (thiazides) Addison's Diuretic stage of renal failure SIADH (serum osmolality low, urine osmolality high, urine Na high) Patient often euvolaemic Mnemonic: Syndrome of INAPPropriate Anti-Diuretic Hormone: In creased Na (sodium) PP (urine) Urinary sodium < 20 mmol/l Sodium depletion, extra-renal loss Diarrhoea, vomiting, sweating Burns, adenoma of rectum (if villous lesion and large) Water excess (patient often hypervolaemic and oedematous) Secondary hyperaldosteronism: CCF, cirrhosis Reduced GFR: renal failure IV dextrose, psychogenic polydipsia Management Symptomatic Hyponatremia : Acute hyponatraemia with Na <120: immediate therapy. Central Pontine Myelinolisis, may occur from overly rapid correction of serum sodium. Aim to correct until the Na is > 125 at a rate of 1 mEq/h. Normal saline with frusemide is an alternative method. The sodium requirement can be calculated as follows : (125 - serum sodium) x 0.6 x body weight = required mEq of sodium

Answer 1097

A less common cause of venous insufficiency is Klippel-Trenaunay-Weber (KTW) syndrome, which involves port-wine stains, varicose veins, and bony or soft-tissue hypertrophy. Lower leg ulcers Venous leg ulcers Most due to venous hypertension, secondary to chronic venous insufficiency (other causes include calf pump dysfunction or neuromuscular disorders) Ulcers form due to capillary fibrin cuff or leucocyte sequestration Features of venous insufficiency include oedema, brown pigmentation, lipodermatosclerosis, eczema Location above the ankle, painless Deep venous insufficiency is related to previous DVT and superficial venous insufficiency is associated with varicose veins Doppler ultrasound looks for presence of reflux and duplex ultrasound looks at the anatomy/ flow of the vein Management: 4 layer compression banding after exclusion of arterial disease or surgery If fail to heal after 12 weeks or >10cm2 skin grafting may be needed Marjolin's ulcer Squamous cell carcinoma Occurring at sites of chronic inflammation e.g; burns, osteomyelitis after 10-20 years Mainly occur on the lower limb Arterial ulcers Occur on the toes and heel Painful There may be areas of gangrene Cold with no palpable pulses Low ABPI measurements Neuropathic ulcers Commonly over plantar surface of metatarsal head and plantar surface of hallux The plantar neuropathic ulcer is the condition that most commonly leads to amputation in diabetic patients Due to pressure Management includes cushioned shoes to reduce callus formation Pyoderma gangrenosum Associated with inflammatory bowel disease/RA Can occur at stoma sites Erythematous nodules or pustules which ulcerate

Answer 1098

Motilin is released by the small bowel in response to alkaline contents in the duodenum/ jejunum and increases the migrating motor complexes in the small bowel Cholecystokinin, secretin and GIP are all released in response to changes in the luminal contents. Gastrin is released from G cells and whilst the luminal contents affect its release, it is also directly released in response to vagal stimuli. Hormonal control of gastric acid secretion Source Stimulus Actions Gastrin G cells in antrum of the stomach Distension of stomach, extrinsic nerves Inhibited by: low antral pH, somatostatin Increase HCL, pepsinogen and IF secretion, increases gastric motility, trophic effect on gastric mucosa CCK I cells in upper small intestine Partially digested proteins and triglycerides Increases secretion of enzyme-rich fluid from pancreas, contraction of gallbladder and relaxation of sphincter of Oddi, decreases gastric emptying, trophic effect on pancreatic acinar cells, induces satiety Secretin S cells in upper small intestine Acidic chyme, fatty acids Increases secretion of bicarbonate-rich fluid from pancreas and hepatic duct cells, decreases gastric acid secretion, trophic effect on pancreatic acinar cells VIP Small intestine, pancreas Neural Stimulates secretion by pancreas and intestines, inhibits acid and pepsinogen secretion Somatostatin D cells in the pancreas and stomach Fat, bile salts and glucose in the intestinal lumen Decreases acid and pepsin secretion, decreases gastrin secretion, decreases pancreatic enzyme secretion, decreases insulin and glucagon secretion inhibits trophic effects of gastrin, stimulates gastric mucous production

Answer 1099

Usually IgG antibodies are formed against the TSH receptors on the thyroid gland. Which is why the TSH level is often very low in Graves disease. Thyroid hormones Hormones of the thyroid gland Triiodothyronine T3 Major hormone active in target cells Thyroxine T4 Most prevalent form in plasma, less biologically active than T3 Calcitonin Lowers plasma calcium Synthesis and secretion of thyroid hormones Thyroid actively concentrates iodide to twenty five times the plasma concentration. Iodide is oxidised by peroxidase in the follicular cells to atomic iodine which then iodinates tyrosine residues contained in thyroglobulin. Iodinated tyrosine residues in thyroglobulin undergo coupling to either T3 or T4. Process is stimulated by TSH, which stimulates secretion of thyroid hormones. The normal thyroid has approximately 3 month reserves of thyroid hormones. LATS and Graves disease In Graves disease, patients develop IgG antibodies to the TSH receptors on the thyroid gland. This results in chronic and long term stimulation of the gland with release of thyroid hormones. The typically situation is raised thyroid hormones and low TSH. Thyroid receptor autoantibodies should be checked in individuals presenting with hyperthyroidism as they are present in up to 85% cases.

Answer 1100

The ansa cervicalis is composed of a superior and inferior root, derived from C1, C2 and C3. The superior root arises where the nerve crosses the internal carotid artery. It descends anterior to the carotid sheath in the anterior triangle. It is joined in the region of the mid neck by the inferior root. The inferior root may pass either superficially or deep to the internal jugular vein. Ansa cervicalis Superior root Branch of C1 anterolateral to carotid sheath Inferior root Derived from C2 and C3 roots, passes posterolateral to the internal jugular vein (may lie either deep or superficial to it) Innervation Sternohyoid Sternothyroid Omohyoid The ansa cervicalis lies anterior to the carotid sheath. The nerve supply to the inferior strap muscles enters at their inferior aspect. Therefore when dividing these muscles to expose a large goitre, the muscles should be divided in their upper half.

Answer 1101

The ophthalmic artery supplies the gland Lacrimal apparatus Comprises the lacrimal gland and its ducts, lacrimal canaliculi, lacrimal sac and naso lacrimal duct. It lies anteriorly in the superolateral region of the orbit and is divided into 2 parts by the levator palpebrae superioris. Numerous ducts empty glandular secretions into the lateral part of the superior fornix of the conjunctiva. The fluid so produced finally accumulates in the lacrimal lake from which it drains via the lacrimal canaliculi, one with each eyelid. Passing medially, the lacrimal canaliculi eventually join the lacrimal sac between the anterior and posterior lacrimal crests, posterior to the medial palpebral ligament and anterior to the lacrimal part of the orbicularis oculi muscle. When the orbicularis oculi muscle contracts during blinking, the small lacrimal part of the muscle dilates the lacrimal sac and draws tears into it. Innervation Secretomotor fibres from the parasympathetic nervous system. The preganglionic parasympathetic neurons leave the CNS in the facial nerve, enter the greater petrosal nerve and continue with this nerve until it becomes the nerve of the pterygoid canal. The nerve of the pterygoid canal eventually joins the pterygopalatine ganglion where the pre-ganglionic parasympathetic neurons synapse on post ganglionic parasympathetic neurons. The post ganglionic neurons join the maxillary nerve and continue with it until the zygomatic nerve branches from it, and travels with the zygomatic nerve until it gives off the zygomaticotemporal nerve which eventually distributes the post ganglionic parasympathetic fibres in a small branch that joins the lacrimal nerve. Sympathetic innervation follows a similar path to the parasympathetic path described above. Post ganglionic sympathetic fibres originating in the superior cervical ganglion travel along the plexus surrounding the internal carotid. They leave this plexus as the deep petrosal nerve and join the parasympathetic fibres in the nerve of the pterygoid canal. Passing through the pterygopalatine ganglion, the parasympathetic fibres from this point onwards follow the same path as the parasympathetic fibres to the lacrimal gland. Vessels Arterial supply is from branches of the ophthalmic artery and venous drainage is to the ophthalmic veins

Answer 1102

Sartorius is supplied by the anterior (superficial) branch of the femoral nerve. Most of the branches of the superficial femoral nerve are cutaneous. However, it does also supply sartorius. Sartorius - Longest strap muscle in the body Most superficial muscle in the anterior compartment of the thigh Origin Anterior superior iliac spine Insertion Medial surface of the of the body of the tibia (upper part). It inserts anterior to gracilis and semitendinosus Nerve Supply Femoral nerve (L2,3 -root values for sartorius) Action Flexor of the hip and knee, slight abducts the thigh and rotates it laterally It assists with medial rotation of the tibia on the femur. For example it would play a pivotal role in placing the right heel onto the left knee ( and vice versa) Important relations The middle third of this muscle, and its strong underlying fascia forms the roof of the adductor canal , in which lie the femoral vessels, the saphenous nerve and the nerve to vastus medialis.

Answer 1103

In the first instance, control of cardiac rate and administration of antithyroid drugs are typically used. Development of jaundice in people with a thyrotoxic storm is well described and the aetiology multifactorial. Management of thyroid disease Management of thyroid disease Lesion Management Large multinodular goitre Surgery for pressure symptoms. Total thyroidectomy is treatment of choice Toxic nodule Hemithyroidectomy Follicular lesion (THY 3f) Hemithyroidectomy to establish diagnosis Papillary thyroid cancer Total thyroidectomy and central compartment nodal dissection (extended lymphadenectomy as required) Follicular thyroid cancer Total thyroidectomy (usually completion as already had hemithyroidectomy) Anaplastic thyroid cancer Palliative radiotherapy Medullary thyroid cancer Total thyroidectomy and central compartment nodal dissection (screen for other MEN tumours) Lymphoma of the thyroid Consider core biopsy Persistent refilling cysts Injection sclerotherapy and surgery if this fails Graves disease with significant eye signs Total thyroidectomy Graves disease without significant eye signs Patient choice radioiodine Vs surgery

Answer 1104

The scrotum is drained by the inguinal nodes. Scrotal and testicular anatomy Spermatic cord Formed by the vas deferens and is covered by the following structures: Layer Origin Internal spermatic fascia Transversalis fascia Cremasteric fascia From the fascial coverings of internal oblique External spermatic fascia External oblique aponeurosis Contents of the cord Vas deferens Transmits sperm and accessory gland secretions Testicular artery Branch of abdominal aorta supplies testis and epididymis Artery of vas deferens Arises from inferior vesical artery Cremasteric artery Arises from inferior epigastric artery Pampiniform plexus Venous plexus, drains into right or left testicular vein Sympathetic nerve fibres Lie on arteries, the parasympathetic fibres lie on the vas Genital branch of the genitofemoral nerve Supplies cremaster Lymphatic vessels Drain to lumbar and para-aortic nodes Scrotum Composed of skin and closely attached dartos fascia. Arterial supply from the anterior and posterior scrotal arteries Lymphatic drainage to the inguinal lymph nodes Parietal layer of the tunica vaginalis is the innermost layer Testes The testes are surrounded by the tunica vaginalis (closed peritoneal sac). The parietal layer of the tunica vaginalis adjacent to the internal spermatic fascia. The testicular arteries arise from the aorta immediately inferiorly to the renal arteries. The pampiniform plexus drains into the testicular veins, the left drains into the left renal vein and the right into the inferior vena cava. Lymphatic drainage is to the para-aortic nodes.

Answer 1105

Factors V and VIII are sensitive to temperature which is the reason why FFP is frozen soon after collection. Blood products Whole blood fractions Fraction Key points Packed red cells Used for transfusion in chronic anaemia and cases where infusion of large volumes of fluid may result in cardiovascular compromise. Product obtained by centrifugation of whole blood. Platelet rich plasma Usually administered to patients who are thrombocytopaenic and are bleeding or require surgery. It is obtained by low speed centrifugation. Platelet concentrate Prepared by high speed centrifugation and administered to patients with thrombocytopaenia. Fresh frozen plasma Prepared from single units of blood. Contains clotting factors, albumin and immunoglobulin. Unit is usually 200 to 250ml. Usually used in correcting clotting deficiencies in patients with hepatic synthetic failure who are due to undergo surgery. Usual dose is 12-15ml/Kg-1. It should not be used as first line therapy for hypovolaemia. Cryoprecipitate Formed from supernatant of FFP. Rich source of Factor VIII and fibrinogen. Allows large concentration of factor VIII to be administered in small volume. SAG-Mannitol Blood Removal of all plasma from a blood unit and substitution with: Sodium chloride Adenine Anhydrous glucose Mannitol Up to 4 units of SAG M Blood may be administered. Thereafter whole blood is preferred. After 8 units, clotting factors and platelets should be considered. Cell saver devices These collect patients own blood lost during surgery and then re-infuse it. There are two main types: Those which wash the blood cells prior to re-infusion. These are more expensive to purchase and more complicated to operate. However, they reduce the risk of re-infusing contaminated blood back into the patient. Those which do not wash the blood prior to re-infusion. Their main advantage is that they avoid the use of infusion of blood from donors into patients and this may reduce risk of blood borne infection. It may be acceptable to Jehovah's witnesses. It is contraindicated in malignant disease for risk of facilitating disease dissemination. Blood products used in warfarin reversal In some surgical patients the use of warfarin can pose specific problems and may require the use of specialised blood products Immediate or urgent surgery in patients taking warfarin(1) (2): 1. Stop warfarin 2. Vitamin K (reversal within 4-24 hours) -IV takes 4-6h to work (at least 5mg) -Oral can take 24 hours to be clinically effective 3. Fresh frozen plasma Used less commonly now as 1st line warfarin reversal -30ml/kg-1 -Need to give at least 1L fluid in 70kg person (therefore not appropriate in fluid overload) -Need blood group -Only use if human prothrombin complex is not available 4. Human Prothrombin Complex (reversal within 1 hour) -Bereplex 50 u/kg -Rapid action but factor 6 short half life, therefore give with vitamin K References 1. Dentali, F., C. Marchesi, et al. (2011). 'Safety of prothrombin complex concentrates for rapid anticoagulation reversal of vitamin K antagonists. A meta-analysis.' Thromb Haemost 106(3): 429-438. 2. http://www.transfusionguidelines.org/docs/pdfs/bbt-03warfarin-reversal-flowchart-2006.pdf

Answer 1106

The left renal vein lies behind of the SMA as it branches off the aorta. Whilst juxtarenal AAA may sometimes require the division of the left renal vein, direct involvement of the SMA may require a hybrid surgical bypass and subsequent endovascular occlusion. Abdominal aortic branches Branches Level Paired Type Inferior phrenic T12 (Upper border) Yes Parietal Coeliac T12 No Visceral Superior mesenteric L1 No Visceral Middle suprarenal L1 Yes Visceral Renal L1-L2 Yes Visceral Gonadal L2 Yes Visceral Lumbar L1-L4 Yes Parietal Inferior mesenteric L3 No Visceral Median sacral L4 No Parietal Common iliac L4 Yes Terminal

Answer 1107

E=2, V= 2, M=2. Glasgow coma scale Modality Options Eye opening Spontaneous To speech To pain None Verbal response Orientated Confused Words Sounds None Motor response Obeys commands Localises to pain Withdraws from pain Abnormal flexion to pain (decorticate posture) Extending to pain None Responses are taken from each category (marks in descending order) to produce an overall score. Severe brain injuries are generally associated with GCS <8.

Answer 1108

Extension of the knee joint is caused by the obturator and femoral nerves. Sensation to the posterior aspect of the thigh is via the posterior cutaneous nerve of the thigh and this is a direct branch from the plexus itself. Sciatic nerve The sciatic nerve is formed from the sacral plexus and is the largest nerve in the body. It is the continuation of the main part of the plexus arising from ventral rami of L4 to S3. These rami converge at the inferior border of piriformis to form the nerve itself. It passes through the inferior part of the greater sciatic foramen and emerges beneath piriformis. Medially, lie the inferior gluteal nerve and vessels and the pudendal nerve and vessels. It runs inferolaterally under the cover of gluteus maximus midway between the greater trochanter and ischial tuberosity. It receives its blood supply from the inferior gluteal artery. The nerve provides cutaneous sensation to the skin of the foot and the leg. It also innervates the posterior thigh muscles and the lower leg and foot muscles. The nerve splits into the tibial and common peroneal nerves approximately half way down the posterior thigh. The tibial nerve supplies the flexor muscles and the common peroneal nerve supplies the extensor muscles and the evertor muscles of the foot. Summary points Origin Spinal nerves L4 - S3 Articular Branches Hip joint Muscular branches in upper leg Semitendinosus Semimembranosus Biceps femoris Part of adductor magnus Cutaneous sensation Posterior aspect of thigh (via cutaneous nerves) Gluteal region Entire lower leg (except the medial aspect) Terminates At the upper part of the popliteal fossa by dividing into the tibial and peroneal nerves The nerve to the short head of the biceps femoris comes from the common peroneal part of the sciatic and the other muscular branches arise from the tibial portion. The tibial nerve goes on to innervate all muscles of the foot except the extensor digitorum brevis (which is innervated by the common peroneal nerve).

Answer 1109

The description provided would fit with bone lesions that are seen in hyperparathyroidism and this would account for the generalised osteopaenia. Malignancies of the prostate present in older adults and the lesions are different. A GI cause may cause malabsorption but not create lucent areas. Renal tumours are often very hypervascular but there is not osteopaenia. Primary hyperparathyroidism In exams, primary hyperparathyroidism is stereotypically seen in elderly females with an unquenchable thirst and an inappropriately normal or raised parathyroid hormone level. It is most commonly due to a solitary adenoma Causes of primary hyperparathyroidism 80%: solitary adenoma 15%: hyperplasia 4%: multiple adenoma 1%: carcinoma Features - 'bones, stones, abdominal groans and psychic moans' Polydipsia, polyuria Peptic ulceration/constipation/pancreatitis Bone pain/fracture Renal stones Depression Hypertension Associations Hypertension Multiple endocrine neoplasia: MEN I and II Investigations Raised calcium, low phosphate PTH may be raised or normal Technetium-MIBI subtraction scan Treatment Parathyroidectomy, if imaging suggests target gland then a focused approach may be used

Answer 1110

Although mesenteric infarct may raise the lactate the pH may be raised often secondary to vomiting. Mesenteric vessel disease Mesenteric ischaemia accounts for 1 in 1000 acute surgical admissions. It is primarily caused by arterial embolism resulting in infarction of the colon. It is more likely to occur in areas such as the splenic flexure that are located at the borders of the territory supplied by the superior and inferior mesenteric arteries. Types Acute mesenteric embolus (commonest 50%) Sudden onset abdominal pain followed by profuse diarrhoea. May be associated with vomiting. Rapid clinical deterioration. Serological tests: WCC, lactate, amylase may all be abnormal particularly in established disease. These can be normal in the early phases. Acute on chronic mesenteric ischaemia Usually longer prodromal history. Post prandial abdominal discomfort and weight loss are dominant features. Patients will usually present with an acute on chronic event, but otherwise will tend not to present until mesenteric flow is reduced by greater than 80%. When acute thrombosis occurs presentation may be as above. In the chronic setting the symptoms will often be those of ischaemic colitis (mucosa is the most sensitive area to this insult). Mesenteric vein thrombosis Usually a history over weeks. Overt abdominal signs and symptoms will not occur until venous thrombosis has reached a stage to compromise arterial inflow. Thrombophilia accounts for 60% of cases. Low flow mesenteric infarction This occurs in patients with multiple co morbidities in whom mesenteric perfusion is significantly compromised by overuse of inotropes or background cardiovascular compromise. The end result is that the bowel is not adequately perfused and infarcts occur from the mucosa outwards. Diagnosis Serological tests: WCC, lactate, CRP, amylase (can be normal in early disease). Cornerstone for diagnosis of arterial AND venous mesenteric disease is CT angiography scanning in the arterial phase with thin slices (<5mm). Venous phase contrast is not helpful. SMA duplex USS is useful in the evaluation of proximal SMA disease in patients with chronic mesenteric ischaemia. MRI is of limited use due to gut peristalsis and movement artefact. Management Overt signs of peritonism: Laparotomy Mesenteric vein thrombosis: If no peritonism: Medical management with IV heparin At operation limited resection of frankly necrotic bowel with view to relook laparotomy at 24-48h. In the interim urgent bowel revascularisation via endovascular (preferred) or surgery. Prognosis Overall poor. Best outlook is from an acute ischaemia from an embolic event where surgery occurs within 12h. Survival may be 50%. This falls to 30% with treatment delay. The other conditions carry worse survival figures.

Answer 1111

The positional nature of the pain and the fact that improves with walking uphill makes an underlying vascular aetiology far less likely. Lumbar spinal stenosis Lumbar spinal stenosis is a condition in which the central canal is narrowed by tumour, disk prolapse or other similar degenerative changes. Patients may present with a combination of back pain, neuropathic pain and symptoms mimicking claudication. One of the main features that may help to differentiate it from true claudication in the history is the positional element to the pain. Sitting is better than standing and patients may find it easier to walk uphill rather than downhill. The neurogenic claudication type history makes lumbar spinal stenosis a likely underlying diagnosis, the absence of such symptoms makes it far less likely. Pathology Degenerative disease is the commonest underlying cause. Degeneration is believed to begin in the intervertebral disk where biochemical changes such as cell death and loss of proteoglycan and water content lead to progressive disk bulging and collapse. This process leads to an increased stress transfer to the posterior facet joints, which accelerates cartilaginous degeneration, hypertrophy, and osteophyte formation; this is associated with thickening and distortion of the ligamentum flavum. The combination of the ventral disk bulging, osteophyte formation at the dorsal facet, and ligamentum flavum hyptertrophy combine to circumferentially narrow the spinal canal and the space available for the neural elements. The compression of the nerve roots of the cauda equina leads to the characteristic clinical signs and symptoms of lumbar spinal stenosis. Diagnosis MRI scanning is the best modality for demonstrating the canal narrowing. Historically a bicycle test was used as true vascular claudicants could not complete the test. Treatment Laminectomy

Answer 1112

In Choanal atresia the episodes of cyanosis are usually worst during feeding. Improvement may be seen when the baby cries as the oropharyngeal airway is used. Choanal atresia Congenital disorder with an incidence of 1 in 7000 births. Posterior nasal airway occluded by soft tissue or bone. Associated with other congenital malformations e.g. coloboma Babies with unilateral disease may go unnoticed. Babies with bilateral disease will present early in life as they can then only breathe through their mouth. Treatment is with fenestration procedures designed to restore patency.

Answer 1113

Ilioinguinal nerve Nerve lesions during surgery A variety of different procedures carry the risk of iatrogenic nerve injury. These are important not only from the patients perspective but also from a medicolegal standpoint. The following operations and their associated nerve lesions are listed here: Posterior triangle lymph node biopsy and accessory nerve lesion. Lloyd Davies stirrups and common peroneal nerve. Thyroidectomy and laryngeal nerve. Anterior resection of rectum and hypogastric autonomic nerves. Axillary node clearance; long thoracic nerve, thoracodorsal nerve and intercostobrachial nerve. Inguinal hernia surgery and ilioinguinal nerve. Varicose vein surgery- sural and saphenous nerves. Posterior approach to the hip and sciatic nerve. Carotid endarterectomy and hypoglossal nerve. There are many more, with sound anatomical understanding of the commonly performed procedures the incidence of nerve lesions can be minimised. They commonly occur when surgeons operate in an unfamiliar tissue plane or by blind placement of haemostats (not recommended).

Answer 1114

The posterior belly of digastric is supplied by the branchial motor component of the facial nerve. All of the other muscles are supplied by axons from the motor nucleus of cranial nerve V. Trigeminal nerve The trigeminal nerve is the main sensory nerve of the head. In addition to its major sensory role, it also innervates the muscles of mastication. Distribution of the trigeminal nerve Sensory Scalp Face Oral cavity (and teeth) Nose and sinuses Dura mater Motor Muscles of mastication Mylohyoid Anterior belly of digastric Tensor tympani Tensor palati Autonomic connections (ganglia) Ciliary Sphenopalatine Otic Submandibular Path Originates at the pons Sensory root forms the large, crescentic trigeminal ganglion within Meckel's cave, and contains the cell bodies of incoming sensory nerve fibres. Here the 3 branches exit. The motor root cell bodies are in the pons and the motor fibres are distributed via the mandibular nerve. The motor root is not part of the trigeminal ganglion. Branches of the trigeminal nerve Ophthalmic nerve Sensory only Maxillary nerve Sensory only Mandibular nerve Sensory and motor Sensory Ophthalmic Exits skull via the superior orbital fissure Sensation of: scalp and forehead, the upper eyelid, the conjunctiva and cornea of the eye, the nose (including the tip of the nose, except alae nasi), the nasal mucosa, the frontal sinuses, and parts of the meninges (the dura and blood vessels). Maxillary nerve Exit skull via the foramen rotundum Sensation: lower eyelid and cheek, the nares and upper lip, the upper teeth and gums, the nasal mucosa, the palate and roof of the pharynx, the maxillary, ethmoid and sphenoid sinuses, and parts of the meninges. Mandibular nerve Exit skull via the foramen ovale Sensation: lower lip, the lower teeth and gums, the chin and jaw (except the angle of the jaw), parts of the external ear, and parts of the meninges. Motor Distributed via the mandibular nerve. The following muscles of mastication are innervated: Masseter Temporalis Medial pterygoid Lateral pterygoid Other muscles innervated include: Tensor veli palatini Mylohyoid Anterior belly of digastric Tensor tympani

Answer 1115

The rectum is supplied by 3 main vessels Superior rectal artery from inferior mesenteric artery Middle rectal artery from the internal iliac artery Inferior rectal artery from the internal pudendal artery The rectum has a dual blood supply. The superior rectal artery is a branch of the inferior mesenteric artery. Inferiorly, it derives a blood supply from branches of the internal iliac artery. Rectum The rectum is approximately 12 cm long. It is a capacitance organ. It has both intra and extraperitoneal components. The transition between the sigmoid colon is marked by the disappearance of the tenia coli.The extra peritoneal rectum is surrounded by mesorectal fat that also contains lymph nodes. This mesorectal fatty layer is removed surgically during rectal cancer surgery (Total Mesorectal Excision). The fascial layers that surround the rectum are important clinical landmarks, anteriorly lies the fascia of Denonvilliers. Posteriorly lies Waldeyers fascia. Extra peritoneal rectum Posterior upper third Posterior and lateral middle third Whole lower third Relations Anteriorly (Males) Rectovesical pouch Bladder Prostate Seminal vesicles Anteriorly (Females) Recto-uterine pouch (Douglas) Cervix Vaginal wall Posteriorly Sacrum Coccyx Middle sacral artery Laterally Levator ani Coccygeus Arterial supply Superior rectal artery Middle rectal artery (from the internal iliac) Inferior rectal artery (from the pudendal vessels) Venous drainage Superior rectal vein Inferior rectal vein Note the venous drainage is a site of portosystemic anastomosis. Lymphatic drainage Mesorectal lymph nodes (superior to dentate line) Inguinal nodes (inferior to dentate line)

Answer 1116

Experimental event rate, EER = 10 / 100 = 0.10 Control event rate, CER = 50 / 300 = 0.166 Therefore the relative risk = EER / CER = 0.1 / 0.166 = 0.6 Relative risk Relative risk (RR) is the ratio of risk in the experimental group (experimental event rate, EER) to risk in the control group (control event rate, CER) To recap EER = rate at which events occur in the experimental group CER = rate at which events occur in the control group For example, if we look at a trial comparing the use of paracetamol for back pain compared to placebo we may get the following results Total number of patients Experienced significant pain relief Paracetamol 100 60 Placebo 80 20 Experimental event rate, EER = 60 / 100 = 0.6 Control event rate, CER = 20 / 80 = 0.25 Therefore the relative risk = EER / CER = 0.6 / 0.25 = 2.4 If the risk ratio is > 1 then the rate of an event (in this case experiencing significant pain relief) is increased compared to controls. It is therefore appropriate to calculate the relative risk increase if necessary (see below). If the risk ratio is < 1 then the rate of an event is decreased compared to controls. The relative risk reduction should therefore be calculated (see below). Relative risk reduction (RRR) or relative risk increase (RRI) is calculated by dividing the absolute risk change by the control event rate Using the above data, RRI = (EER - CER) / CER = (0.6 - 0.25) / 0.25 = 1.4 = 140%

Answer 1117

The duct crosses the masseter muscle and buccal fat pad and then penetrates the buccinator muscle to enter the oral cavity opposite the second upper molar tooth. Parotid gland Anatomy of the parotid gland Location Overlying the mandibular ramus; anterior and inferior to the ear. Salivary duct Crosses the masseter, pierces the buccinator and drains adjacent to the 2nd upper molar tooth (Stensen's duct). Structures passing through the gland Facial nerve (Mnemonic: The Zebra Buggered My Cat; Temporal Zygomatic, Buccal, Mandibular, Cervical) External carotid artery Retromandibular vein Auriculotemporal nerve Relations Anterior: masseter, medial pterygoid, superficial temporal and maxillary artery, facial nerve, stylomandibular ligament Posterior: posterior belly digastric muscle, sternocleidomastoid, stylohyoid, internal carotid artery, mastoid process, styloid process Arterial supply Branches of external carotid artery Venous drainage Retromandibular vein Lymphatic drainage Deep cervical nodes Nerve innervation Parasympathetic-Secretomotor Sympathetic-Superior cervical ganglion Sensory- Greater auricular nerve Parasympathetic stimulation produces a water rich, serous saliva. Sympathetic stimulation leads to the production of a low volume, enzyme-rich saliva.

Answer 1118

The 60-40-20 rule: 60% total body weight is water 40% of total body weight is intracellular fluids 20% of body weight is extracellular fluids Plasma typically accounts for 4-6% of body weight in healthy individuals. Males typically have more water per unit weight than females, as females have a higher fat content. Fluid compartment physiology Body fluid compartments comprise intracellular and extracellular compartments. The latter includes interstitial fluid, plasma and transcellular fluid. Typical figures are based on the 70 Kg male. Body fluid volumes Compartment Volume in litres Percentage of total volume Intracellular 28 L 60-65% Extracellular 14 L 35-40% Plasma 3 L 5% Interstitial 10 L 24% Transcellular 1 L 3% Figures are approximate

Answer 1119

The radial nerve is most commonly injured and results in a wrist drop. The ulnar nerve arises from the medial cord and is rarely affected as a result of this injury mechanism. Brachial plexus The brachial plexus extends from the neck to the axilla. It is formed by the ventral rami of the fifth to the eighth cervical nerves with the ascending part of the first thoracic nerve. Location of the plexus The ventral rami which form the plexus enter the lower part of the posterior triangle of the neck in series with the ventral rami of the cervical plexus. The second part of the subclavian artery lies immediately anterior to the lower two rami. The upper three rami intermingle and pass inferolaterally towards the axilla and subclavian artery. They are enclosed within an extension of the prevertebral fascia. In the neck the plexus lies deep to platysma, the supraclavicular nerves, inferior belly of omohyoid and the transverse cervical artery. It then passes deep to the clavicle and the suprascapular vessels, to enter the axilla, and thence surround the second part of the axillary artery Composition of the plexus Ventral rami, the roots of the plexus, lie between scalenus medius and anterior. As they enter the posterior triangle, the upper two (C5,6) and lower two (C8, T1) roots of the plexus unite to form the upper and lower trunks of the plexus respectively. Meanwhile, C7 continues as the middle trunk. The lower trunk may groove the superior surface of the first rib posterior to the subclavian artery, and the root from the first ventral ramus is always in contact with it. Each trunk divides into ventral and dorsal divisions which are destined to supply the anterior (flexor) and posterior (extensor) parts of the upper limb. The cords of the plexus are formed in the axilla. The dorsal divisions unite to form the posterior cord (C5-8). The ventral divisions of the upper and middle trunks unite to form the lateral cord (C5-7), while the ventral divisions of the lower trunk continues as the medial cord (C8-T1). The cords are named according to their relationship to the axillary artery. Each cord terminates by dividing into two main branches at the beginning of the third part of the artery. Sympathetic communications The fifth and sixth cervical ventral rami receive grey rami communicantes from the middle cervical ganglion, while the two or more grey rami communicantes pass from the inferior cervical ganglion to the seventh and eighth cervical ventral rami. The first thoracic ventral ramus receives its grey ramus from the cervicothoracic ganglion. Its for this reason that inferior plexus injury can be complicated by a Horners syndrome. Summary Origin Anterior rami of C5 to T1 Sections of the plexus Roots, trunks, divisions, cords, branches Mnemonic:Real Teenagers Drink Cold Beer Roots Located in the posterior triangle Pass between scalenus anterior and medius Trunks Located posterior to middle third of clavicle Upper and middle trunks related superiorly to the subclavian artery Lower trunk passes over 1st rib posterior to the subclavian artery Divisions Apex of axilla Cords Related to axillary artery

Answer 1120

Cryptosporidium is associated with infection, particularly in those who are immunocompromised. Diarrhoea is the main disease. The cysts are typically identified on stool microscopy. Gastro intestinal parasitic infections Common infections Enterobiasis Due to organism Enterobius vermicularis Common cause of pruritus ani Diagnosis usually made by placing scotch tape at the anus, this will trap eggs that can then be viewed microscopically Treatment is with mebendazole Ancylostoma duodenale Hookworms that anchor in proximal small bowel Most infections are asymptomatic although may cause iron deficiency anaemia Larvae may be found in stools left at ambient temperature, otherwise infection is difficult to diagnose Infection occurs as a result of cutaneous penetration, migrates to lungs, coughed up and then swallowed Treatment is with mebendazole Ascariasis Due to infection with roundworm Ascaris lumbricoides Infections begin in gut following ingestion, then penetrate duodenal wall to migrate to lungs, coughed up and swallowed, cycle begins again Diagnosis is made by identification of worm or eggs within faeces Treatment is with mebendazole Strongyloidiasis Due to infection with Strongyloides stercoralis Rare in west Organism is a nematode living in duodenum of host Initial infection is via skin penetration. They then migrate to lungs and are coughed up and swallowed. Then mature in small bowel are excreted and cycle begins again An auto infective cycle is also recognised where larvae will penetrate colonic wall Individuals may be asymptomatic, although they may also have respiratory disease and skin lesions Diagnosis is usually made by stool microscopy In the UK mebendazole is used for treatment Cryptosporidium Protozoal infection Organisms produce cysts which are excreted and thereby cause new infections Symptoms consist of diarrhoea and cramping abdominal pains. Symptoms are worse in immunosuppressed people Cysts may be identified in stools Treatment is with metronidazole Giardiasis Diarrhoeal infection caused by Giardia lamblia (protozoan) Infections occur as a result of ingestion of cysts Symptoms are usually gastrointestinal with abdominal pain, bloating and passage of soft or loose stools Diagnosis is by serology or stool microscopy First line treatment is with metronidazole

Answer 1121

The use of esmarch bandage tourniquet increases the risk of nerve injury as it increases pressure in the limb. Limb elevation is safer. Tourniquets Tourniquets are used during surgery to minimise blood loss and ensure a clear operative field. They must be correctly applied and monitored. They are applied to extremities and in most cases are inflated using a pressure monitoring system. There are a number of systemic effects that can accompany tourniquet use, these can be divided into those which occur following inflation and those that occur once the tourniquet is deflated. Post inflation Increased systemic vascular resistance, increased CVP and increased BP Slower gradual increase in BP over time Induced hypercoagulable state Slow increase in core temperature Post deflation Fall in CVP, BP and SVR Increased end tidal carbon dioxide Enhanced fibrinolysis Fall in core temperature Raised serum potassium and lactate levels Contra indications Absolute Relative AV fistula Severe peripheral vascular disease Previous vascular surgery Bone fracture or thrombosis at the site of tourniquet application Sickle cell disease History of thromboembolic events Skin grafts Localised infection Lymphoedema Local complications Damage to skin Damage to muscle (rarely compartment syndrome) Damage to vessels Neuropraxia

Answer 1122

The intercostal vein is more superior than the artery and is thus slightly less susceptible to injury. Within the intercostal spaces there are thin, strong muscles, intercostal vessels, nerves and lymphatics. There are 3 intercostal muscle layers corresponding to the lateral abdominal wall; external, internal, innermost intercostals. At the mid axillary line there are thin intracostals which is an extension of the internal intercostal muscle. In each intercostal space lies the neurovascular bundle, comprising, from superior to inferiorly; the posterior intercostal vein, artery and nerve, lying protected in the subcostal groove of the rib above and situated between the second and third layer of the intercostal muscles. These blood vessels anastomose anteriorly with the anterior intercostal vessels, which arise from the internal thoracic artery and vein. Chest drains There are a number of different indications for chest drain insertion. In general terms large bore chest drains are preferred for trauma and haemothorax drainage. Smaller diameter chest drains can be used for pneumothorax or pleural effusion drainage. Insertion can be performed either using anatomical guidance or through ultrasound guidance. In the exam, the anatomical method is usually tested. It is advised that chest drains are placed in the 'safe triangle'. The triangle is located in the mid axillary line of the 5th intercostal space. It is bordered by: Anterior edge latissimus dorsi, the lateral border of pectoralis major, a line superior to the horizontal level of the nipple, and the apex below the axilla. Another triangle is situated behind the scapula. It is bounded above by the trapezius, below by the latissimus dorsi, and laterally by the vertebral border of the scapula; the floor is partly formed by the rhomboid major. If the scapula is drawn forward by folding the arms across the chest, and the trunk bent forward, parts of the sixth and seventh ribs and the interspace between them become subcutaneous and available for auscultation. The space is therefore known as the triangle of auscultation. References Prof Harold Ellis. The applied anatomy of chest drains insertions. British Journal of hospital medicine 2007; (68): 44-45. Laws D, Neville E, Duffy J. BTS guidelines for insertion of chest drains. Thorax, 2003; (58): 53-59.

Answer 1123

Malignant melanoma The main diagnostic features (major criteria): Change in size Change in shape Change in colour Secondary features (minor criteria) Diameter >6mm Inflammation Oozing or bleeding Altered sensation Treatment Suspicious lesions should undergo excision biopsy. The lesion should be removed in completely as incision biopsy can make subsequent histopathological assessment difficult. Once the diagnosis is confirmed the pathology report should be reviewed to determine whether further re-excision of margins is required (see below): Margins of excision-Related to Breslow thickness Lesions 0-1mm thick 1cm Lesions 1-2mm thick 1- 2cm (Depending upon site and pathological features) Lesions 2-4mm thick 2-3 cm (Depending upon site and pathological features) Lesions >4 mm thick 3cm Marsden J et al Revised UK guidelines for management of Melanoma. Br J Dermatol 2010 163:238-256. Further treatments such as sentinel lymph node mapping, isolated limb perfusion and block dissection of regional lymph node groups should be selectively applied. Guidelines The UK NICE guidance is covered by Melanoma: assessment and management NICE guideline [NG14]. However, the complex oncological regimens are not extensively covered in this guidance though more formal guidance is provided by relevant oncological organisations.

Answer 1124

The internal carotid artery lies posterolaterally to the external carotid artery at it's origin from the common carotid. The superior thyroid, lingual and facial arteries all arise from its anterior surface. External carotid artery The external carotid commences immediately lateral to the pharyngeal side wall. It ascends and lies anterior to the internal carotid and posterior to the posterior belly of digastric and stylohyoid. More inferiorly it is covered by sternocleidomastoid, passed by hypoglossal nerves, lingual and facial veins. It then pierces the fascia of the parotid gland finally dividing into its terminal branches within the gland itself. Surface marking of the carotid This is an imaginary line drawn from the bifurcation of the common carotid passing behind the angle of the jaw to a point immediately anterior to the tragus of the ear. Branches of the external carotid artery It has six main branches, three in front, two behind and one deep. Three in front Superior thyroid Lingual Facial Two behind Occipital Posterior auricular Deep Ascending pharyngeal It terminates by dividing into the superficial temporal and maxillary arteries in the parotid gland.

Answer 1125

The absence of trauma here makes an acute sub dural and extra dural bleed unlikely. Chronic sub dural bleeds would usually cause a more gradual deterioration than is seen here. The absence of any skull fracture also makes an underlying intra cranial bleed less likely. Sudden onset headaches, together with sudden deterioration in neurological function are typical of a sub arachnoid haemorrhage. Intra cranial haemorrhage Extradural haematoma Bleeding into the space between the dura mater and the skull. Often results from acceleration-deceleration trauma or a blow to the side of the head. The majority of extradural haematomas occur in the temporal region where skull fractures cause a rupture of the middle meningeal artery. Features Raised intracranial pressure Some patients may exhibit a lucid interval Subdural haematoma Bleeding into the outermost meningeal layer. Most commonly occur around the frontal and parietal lobes. May be either acute or chronic. Risk factors include old age and alcoholism. Slower onset of symptoms than a extradural haematoma. Intracerebral haematoma Usually hyperdense lesions on CT scanning. Arise in areas of traumatic contusion which fuse to become a haematoma. Areas of clot and fresh blood may co-exist on the same CT scan (Swirl sign). Large haematomas and those associated with mass effect should be evacuated. Subarachnoid haemorrhage Usually occurs spontaneously in the context of a ruptured cerebral aneurysm but may be seen in association with other injuries when a patient has sustained a traumatic brain injury Intraventricular haemorrhage Haemorrhage that occurs into the ventricular system of the brain. It is relatively rare in adult surgical practice and when it does occur, it is typically associated with severe head injuries. In premature neonates it may occur spontaneously. The blood may clot and occlude CSF flow, hydrocephalus may result. In neonatal practice the vast majority of IVH occur in the first 72 hours after birth, the aetiology is not well understood and it is suggested to occur as a result of birth trauma combined with cellular hypoxia, together with the delicate neonatal CNS.

Answer 1126

The sub mandibular gland is the most common site for salivary calculi. Patients will usually complain of pain, which is worse on eating. When the lesion is located distally the duct may be laid open and the stone excised. Otherwise the gland will require removal. In this case the increase in size will be the result of infection occurring in a blocked duct. Neck lumps The table below gives characteristic exam question features for conditions causing neck lumps: Reactive lymphadenopathy By far the most common cause of neck swellings. There may be a history of local infection or a generalised viral illness Lymphoma Rubbery, painless lymphadenopathy The phenomenon of pain whilst drinking alcohol is very uncommon There may be associated night sweats and splenomegaly Thyroid swelling May be hypo-, eu- or hyperthyroid symptomatically Moves upwards on swallowing Thyroglossal cyst More common in patients < 20 years old Usually midline, between the isthmus of the thyroid and the hyoid bone Moves upwards with protrusion of the tongue May be painful if infected Pharyngeal pouch More common in older men Represents a posteromedial herniation between thyropharyngeus and cricopharyngeus muscles Usually not seen, but if large then a midline lump in the neck that gurgles on palpation Typical symptoms are dysphagia, regurgitation, aspiration and chronic cough Cystic hygroma A congenital lymphatic lesion (lymphangioma) typically found in the neck, classically on the left side Most are evident at birth, around 90% present before 2 years of age Branchial cyst An oval, mobile cystic mass that develops between the sternocleidomastoid muscle and the pharynx Develop due to failure of obliteration of the second branchial cleft in embryonic development Usually present in early adulthood Cervical rib More common in adult females Around 10% develop thoracic outlet syndrome Carotid aneurysm Pulsatile lateral neck mass which doesn't move on swallowing

Answer 1127

Patients with significant mediastinal and lung injuries are best operated on using a Clam shell thoracotomy. All modes of access involve a degree of compromise. A sternotomy would give good access to the heart. However, it takes longer to perform and does not provide good access to the lungs. Trauma should not be managed using laparoscopy. Trauma management The cornerstone of trauma management is embodied in the principles of ATLS. Following trauma there is a trimodal death distribution: Immediately following injury. Typically as result of brain or high spinal injuries, cardiac or great vessel damage. Salvage rate is low. In early hours following injury. In this group deaths are due to phenomena such as splenic rupture, sub dural haematomas and haemopneumothoraces In the days following injury. Usually due to sepsis or multi organ failure. Aspects of trauma management ABCDE approach. Tension pneumothoraces will deteriorate with vigorous ventilation attempts. External haemorrhage is managed as part of the primary survey. As a rule tourniquets should not be used. Blind application of clamps will tend to damage surrounding structures and packing is the preferred method of haemorrhage control. Urinary catheters and naso gastric tubes may need inserting. Be wary of basal skull fractures and urethral injuries. Patients with head and neck trauma should be assumed to have a cervical spine injury until proven otherwise. Thoracic injuries Simple pneumothorax Mediastinal traversing wounds Tracheobronchial tree injury Haemothorax Blunt cardiac injury Diaphragmatic injury Aortic disruption Pulmonary contusion Management of thoracic trauma Simple pneumothorax insert chest drain. Aspiration is risky in trauma as pneumothorax may be from lung laceration and convert to tension pneumothorax. Mediastinal traversing wounds These result from situations like stabbings. Exit and entry wounds in separate hemithoraces. The presence of a mediastinal haematoma indicates the likelihood of a great vessel injury. All patients should undergo CT angiogram and oesophageal contrast swallow. Indications for thoracotomy are largely related to blood loss and will be addressed below. Tracheobronchial tree injury Unusual injuries. In blunt trauma most injuries occur within 4cm of the carina. Features suggesting this injury include haemoptysis and surgical emphysema. These injuries have a very large air leak and may have tension pneumothorax. Haemothorax Usually caused by laceration of lung vessel or internal mammary artery by rib fracture. Patients should all have a wide bore 36F chest drain. Indications for thoracotomy include loss of more than 1.5L blood initially or ongoing losses of >200ml per hour for >2 hours. Cardiac contusions Usually cardiac arrhythmias, often overlying sternal fracture. Perform echocardiography to exclude pericardial effusions and tamponade. Risk of arrhythmias falls after 24 hours. Diaphragmatic injury Usually left sided. Direct surgical repair is performed. Traumatic aortic disruption Commonest cause of death after RTA or falls. Usually incomplete laceration near ligamentum arteriosum. All survivors will have contained haematoma. Only 1-2% of patients with this injury will have a normal chest x-ray. Pulmonary contusion Common and lethal. Insidious onset. Early intubation and ventilation. Abdominal trauma Deceleration injuries are common. In blunt trauma requiring laparotomy the spleen is most commonly injured (40%) Stab wounds traverse structures most commonly liver (40%) Gunshot wounds have variable effects depending upon bullet type. Small bowel is most commonly injured (50%) Patients with stab wounds and no peritoneal signs up to 25% will not enter the peritoneal cavity Blood at urethral meatus suggests a urethral tear High riding prostate on PR = urethral disruption Mechanical testing for pelvic stability should only be performed once Investigations in abdominal trauma Diagnostic Peritoneal Lavage Abdominal CT scan USS Indication Document bleeding if hypotensive Document organ injury if normotensive Document fluid if hypotensive Advantages Early diagnosis and sensitive; 98% accurate Most specific for localising injury; 92 to 98% accurate Early diagnosis, non invasive and repeatable; 86 to 95% accurate Disadvantages Invasive and may miss retroperitoneal and diaphragmatic injury Location of scanner away from facilities, time taken for reporting, need for contrast Operator dependent and may miss retroperitoneal injury Amylase may be normal following pancreatic trauma Urethrography if suspected urethral injury

Answer 1128

Spitz naevi can often resemble melanoma and are best excised. Benign skin diseases Seborrhoeic keratosis Most commonly arise in patients over the age of 50 years, often idiopathic Equal sex incidence and prevalence Usually multiple lesions over face and trunk Flat, raised, filiform and pedunculated subtypes are recognised Variable colours and surface may have greasy scale overlying it Treatment options consist of leaving alone or simple shave excision Melanocytic naevi Congenital melanocytic naevi Typically appear at, or soon after, birth Usually greater than 1cm diameter Increased risk of malignant transformation (increased risk greatest for large lesions) Junctional melanocytic naevi Circular macules May have heterogeneous colour even within same lesion Most naevi of the palms, soles and mucous membranes are of this type Compound naevi Domed pigmented nodules up to 1cm in diameter Arise from junctional naevi, usually have uniform colour and are smooth Spitz naevus Usually develop over a few months in children May be pink or red in colour, most common on face and legs May grow up to 1cm and growth can be rapid, this usually results in excision Atypical naevus syndrome Atypical melanocytic naevi that may be autosomally dominantly inherited Some individuals are at increased risk of melanoma (usually have mutations of CDKN2A gene) Many people with atypical naevus syndrome AND a parent sibling with melanoma will develop melanoma Epidermoid cysts Common and affect face and trunk They have a central punctum, they may contain small quantities of sebum The cyst lining is either normal epidermis (epidermoid cyst) or outer root sheath of hair follicle (pilar cyst) Dermatofibroma Solitary dermal nodules Usually affect extremities of young adults Lesions feel larger than they appear visually Histologically they consist of proliferating fibroblasts merging with sparsely cellular dermal tissues Painful skin lesions Eccrine spiradenoma Neuroma Glomus tumour Leiomyoma Angiolipoma Neurofibroma (rarely painful) and dermatofibroma (rarely painful)

Answer 1129

Liver lesions that are suspicious of HCC should be scanned prior to resection as there is a risk of multifocal lesions that would either preclude or otherwise affect the decision to proceed with segmental resection. Hepatocellular carcinoma Hepatocellular carcinoma is the second leading cause of cancer deaths globally. Up to 750,000 cases are reported annually. Unfortunately the incidence approximates to the death rate so there are few long term survivors[1]. The disease occurs most commonly in those with chronic hepatitis and established liver cirrhosis. Therefore, these individuals should be closely screened for the development of HCC with serum AFP and liver USS every 6-12 months. Rising AFP and liver USS showing a nodule greater than 1cm in diameter makes HCC much more likely and such patients should then undergo MRI scanning. The presence of adenomas in an otherwise healthy liver is a recognised risk factor for HCC [2, 3] and many surgeons will remove liver adenomas for this reason[4]. Diagnosis The aim is to avoid unnecessary percutaneous biopsy. Radiologically on CT the classical feature is a suspicious lesion which is highlighted during the arterial phase with washout during the venous phase, this reflects the hypervascularity of the lesions.The risk of tumour seeding as a result of a liver biopsy is 2.7% with a median time interval between biopsy and seeding of 17 months[5]. Barcelona Clinic Liver Classification There are many classification systems for addressing the management and prognosis, the BCLC system has the convenience of categorising disease extent with treatment and prognostic outcomes. In determining the ideal treatment modality for HCC the key points are not just disease extent, but also the functional state of the liver and patient. Stage Features Treatment Prognosis-5 yr survival Stage 0 Child-Pugh A Single lesion (less than 2cm) Normal portal pressures Resection 40-70% Stage A Single nodule greater than 3cm or multiple nodules (no more than 3) Child Pugh A/ B If associated disease then radiofrequency ablation If no associated disease then transplantation May be up to 70% in some Stage B Multiple nodules Child Pugh A/B Trans arterial chemo-embolisation (usually with doxorubicin) 26% at 3 years Stage C Advanced tumours Invasion of portal vein Child Pugh A/B Sorafenib Usually survive 10.7 months Stage D Child Pugh stage C Advanced tumours Best supportive care Less than 6 months survival [6] In selected patients the best outcomes are achieved with surgical resection, or transplantation where surgical resection is precluded. Anatomical resections with minimum 2cm margins provide the best outcomes. At the present time there is no evidence to recommend treatment with adjuvant chemotherapy[6]. Sorafenib This is an oral multi tyrosine kinase inhibitor. It is the only drug that has been currently demonstrated to extend survival in individuals with advanced hepatocellular cancer[7]. The improvement in survival is from a median of 7 months to 10 months. References 1. Jemal, A., et al., Global cancer statistics. CA Cancer J Clin, 2011. 61(2): p. 69-90. 2. Leese, T., O. Farges, and H. Bismuth, Liver cell adenomas. A 12-year surgical experience from a specialist hepato-biliary unit. Ann Surg, 1988. 208(5): p. 558-64. 3. Farges, O. and S. Dokmak, Malignant transformation of liver adenoma: an analysis of the literature. Dig Surg, 2010. 27(1): p. 32-8. 4. Ehrl, D., et al., 'Incidentaloma' of the liver: management of a diagnostic and therapeutic dilemma. HPB Surg, 2012. 2012: p. 891787. 5. Silva, M.A., et al., Needle track seeding following biopsy of liver lesions in the diagnosis of hepatocellular cancer: a systematic review and meta-analysis. Gut, 2008. 57(11): p. 1592-6. 6. EASL-EORTC clinical practice guidelines: management of hepatocellular carcinoma. J Hepatol, 2012. 56(4): p. 908-43. 7. Abou-Alfa, G.K., et al., Phase II study of sorafenib in patients with advanced hepatocellular carcinoma. J Clin Oncol, 2006. 24(26): p. 4293-300.

Answer 1130

It enters the gland at C6. Surface anatomy of the neck In the midline from above down, the following structures are felt Structure Level Hyoid C3 Notch of the thyroid cartilage C4 Cricoid cartilage(termination) C6 The lower border of the cricoid cartilage corresponds to the commencement of the trachea and also to the following: Junction of larynx with trachea Junction of pharynx with oesophagus Level at which the inferior thyroid artery enters the thyroid gland The level at which the vertebral artery enters the transverse foramen in the 6th cervical vertebra Level at which the superior belly of omohyoid crosses the carotid sheath The level of the middle cervical sympathetic ganglion The level at which the carotid artery can be compressed against the transverse process of C6 (carotid tubercle).

Answer 1131

This will be a retroperitoneal rupture (anterior ones generally don't survive to hospital). The debate regarding CT varies, it is the authors opinion that a systolic BP of <100mmHg at presentation mandates immediate laparotomy. Acute abdominal pain-diagnoses Conditions presenting with acute abdominal pain Condition Features Investigations Management Appendicitis History of migratory pain. Fever. Anorexia. Evidence of right iliac fossa tenderness. Mild pyrexia. Differential white cell count Pregnancy test C-Reactive protein Amylase Urine dipstick testing Appendicectomy Mesenteric adenitis Usually recent upper respiratory tract infection. High fever. Generalised abdominal discomfort- true localised pain and signs are rare. Full blood count- may show slightly raised white cell count Urine dipstick often normal Abdominal ultrasound scan - usually no free fluid Conservative management- appendicectomy if diagnostic doubt Mittelschmerz Only seen in females Mid cycle pain Usually occurs two weeks after last menstrual period Pain usually has a supra-pubic location Usually subsides over a 24-48 hour period. Full blood count- normal Urine dipstick- normal Abdominal and pelvic ultrasound- may show a trace of pelvic free fluid Manage conservatively if doubt or symptoms fail to settle then laparoscopy Fitz-Hugh Curtis syndrome Disseminated infection with Chlamydia. Usually seen in females. Consists of evidence of pelvic inflammatory disease together with peri-hepatic inflammation and subsequent adhesion formation. Abdominal ultrasound scan- may show free fluid High vaginal swabs - may show evidence of sexually transmitted infections Usually medically managed- doxycycline or azithromycin Abdominal aortic aneurysm (ruptured) Sudden onset of abdominal pain radiating to the back in older adults (look for risk factors). Collapse. May be moribund on arrival in casualty, more stable if contained haematoma. Careful clinical assessment may reveal pulsatile mass. Patients who are haemodynamically stable should have a CT scan Unstable patients should undergo immediate surgery (unless it is not in their best interests). Those with evidence of contained leak on CT should undergo immediate surgery Increasing unruptured aneurysmal size is an indication for urgent surgical intervention (that can wait until the next working day) Perforated peptic ulcer Sudden onset of pain (usually epigastric). Often preceding history of upper abdominal pain. Soon develop generalised abdominal pain. On examination may have clinical evidence of peritonitis. Erect CXR may show free air. A CT scan may be indicated where there is diagnostic doubt Laparotomy (laparoscopic surgery for perforated peptic ulcers is both safe and feasible in experienced hands) Intestinal obstruction Colicky abdominal pain and vomiting (the nature of which depends on the level of the obstruction). Abdominal distension and constipation (again depending upon site of obstruction). Features of peritonism may occur where local necrosis of bowel loops is occurring. A plain abdominal film may help with making the diagnosis. A CT scan may be useful where diagnostic uncertainty exists In those with a virgin abdomen a lower and earlier threshold for laparotomy should exist than in those who may have adhesional obstruction Mesenteric infarction Embolic events present with sudden pain and forceful evacuation. Acute on chronic events usually have a longer history and previous weight loss. On examination the pain is typically greater than the physical signs would suggest. Arterial pH and lactate Arterial phase CT scanning is the most sensitive test Immediate laparotomy and resection of affected segments, in acute embolic events SMA embolectomy may be needed.

Answer 1132

Infection from omphalitis may spread rapidly and cause severe sepsis especially in immunologically compromised, premature neonates. Paediatric umbilical disorders Embryology During development the umbilicus has two umbilical arteries and one umbilical vein. The arteries are continuous with the internal iliac arteries and the vein is continuous with the falciform ligament (ductus venosus). After birth the cord dessicates and separates and the umbilical ring closes. Umbilical hernia Up to 20% of neonates may have an umbilical hernia, it is more common in premature infants. The majority of these hernias will close spontaneously (may take between 12 months and three years). Strangulation is rare. Paraumbilical hernia These are due to defects in the linea alba that are in close proximity to the umbilicus. The edges of a paraumbilical hernia are more clearly defined than those of an umbilical hernia. They are less likely to resolve spontaneously than an umbilical hernia. Omphalitis This condition consists of infection of the umbilicus. Infection with Staphylococcus aureus is the commonest cause. The condition is potentially serious as infection may spread rapidly through the umbilical vessels in neonates with a risk of portal pyaemia, and portal vein thrombosis. Treatment is usually with a combination of topical and systemic antibiotics. Umbilical granuloma These consist of cherry red lesions surrounding the umbilicus, they may bleed on contact and be a site of seropurulent discharge. Infection is unusual and they will often respond favorably to chemical cautery with topically applied silver nitrate. Persistent urachus This is characterised by urinary discharge from the umbilicus. It is caused by persistence of the urachus which attaches to the bladder. They are associated with other urogenital abnormalities. Persistent vitello-intestinal duct This will typically present as an umbilical discharge that discharges small bowel content. Complete persistence of the duct is a rare condition. Much more common is the persistence of part of the duct (Meckels diverticulum). Persistent vitello-intestinal ducts are best imaged using a contrast study to delineate the anatomy and are managed by laparotomy and surgical closure.

Answer 1133

When it does occur, a burst abdomen is most common at 6 days and is usually the result of technical error when Jenkins rule is not followed and sutures are placed in the zone of collagenolysis. The choice of materials given above does not influence dehisence rates. Abdominal wound dehiscence - This is a significant problem facing all surgeons who undertake abdominal surgery on a regular basis. Traditionally, it is said to occur when all layers of an abdominal mass closure fail and the viscera protrude externally (associated with 30% mortality). It can be subdivided into superficial, in which the skin wound alone fails and complete, implying failure of all layers. Factors which increase the risk are: * Malnutrition * Vitamin deficiencies * Jaundice * Steroid use * Major wound contamination (e.g. faecal peritonitis) * Poor surgical technique (Mass closure technique is the preferred method-Jenkins Rule) When sudden full dehiscence occurs the management is as follows: * Analgesia * Intravenous fluids * Intravenous broad spectrum antibiotics * Coverage of the wound with saline impregnated gauze (on the ward) * Arrangements made for a return to theatre Surgical strategy Correct the underlying cause (e.g. TPN or NG feed if malnourished) Determine the most appropriate strategy for managing the wound Options Resuturing of the wound This may be an option if the wound edges are healthy and there is enough tissue for sufficient coverage. Deep tension sutures are traditionally used for this purpose. Application of a wound manager This is a clear dressing with removable front. Particularly suitable when some granulation tissue is present over the viscera or where there is a high output bowel fistula present in the dehisced wound. Application of a 'Bogota bag' This is a clear plastic bag that is cut and sutured to the wound edges and is only a temporary measure to be adopted when the wound cannot be closed and will necessitate a return to theatre for definitive management. Application of a VAC dressing system These can be safely used BUT ONLY if the correct layer is interposed between the suction device and the bowel. Failure to adhere to this absolute rule will almost invariably result in the development of multiple bowel fistulae and create an extremely difficult management problem.

Answer 1134

Direct inguinal hernias pass through Hesselbachs triangle (although this is of minimal clinical significance!). Its medial boundary is the rectus muscle. Hesselbach's triangle Direct hernias pass through Hesselbachs triangle. Superolaterally Epigastric vessels Medially Lateral edge of rectus muscle Inferiorly Inguinal ligament

Answer 1135

Sartorius is supplied by the femoral nerve. In approximately 20% of the population, pectineus is supplied by the accessory obturator nerve. Adductor magnus has a composite supply from the obturator and sciatic nerves. Obturator nerve The obturator nerve arises from L2, L3 and L4 by branches from the ventral divisions of each of these nerve roots. L3 forms the main contribution and the second lumbar branch is occasionally absent. These branches unite in the substance of psoas major, descending vertically in its posterior part to emerge from its medial border at the lateral margin of the sacrum. It then crosses the sacroiliac joint to enter the lesser pelvis, it descends on obturator internus to enter the obturator groove. In the lesser pelvis the nerve lies lateral to the internal iliac vessels and ureter, and is joined by the obturator vessels lateral to the ovary or ductus deferens. Supplies Medial compartment of thigh Muscles supplied: external obturator, adductor longus, adductor brevis, adductor magnus (not the lower part-sciatic nerve), gracilis The cutaneous branch is often absent. When present, it passes between gracilis and adductor longus near the middle part of the thigh, and supplies the skin and fascia of the distal two thirds of the medial aspect. Obturator canal Connects the pelvis and thigh: contains the obturator artery, vein, nerve which divides into anterior and posterior branches.

Answer 1136

The inferior gluteal artery runs on the deep surface of the gluteus maximus muscle. It is a branch of the internal iliac artery. It is commonly divided during the posterior approach to the hip joint. Hip joint Head of femur articulates with acetabulum of the pelvis Both covered by articular hyaline cartilage The acetabulum forms at the union of the ilium, pubis, and ischium The triradiate cartilage (Y-shaped growth plate) separates the pelvic bones The acetabulum holds the femoral head by the acetabular labrum Normal angle between femoral head and femoral shaft is 130o Ligaments Transverse ligament: joints anterior and posterior ends of the articular cartilage Head of femur ligament (ligamentum teres): acetabular notch to the fovea. Contains arterial supply to head of femur in children. Hip joint Head of femur articulates with acetabulum of the pelvis Both covered by articular hyaline cartilage The acetabulum forms at the union of the ilium, pubis, and ischium The triradiate cartilage (Y-shaped growth plate) separates the pelvic bones The acetabulum holds the femoral head by the acetabular labrum Normal angle between femoral head and femoral shaft is 130o Ligaments Transverse ligament: joints anterior and posterior ends of the articular cartilage Head of femur ligament (ligamentum teres): acetabular notch to the fovea. Contains arterial supply to head of femur in children. Extracapsular ligaments Iliofemoral ligament: inverted Y shape. Anterior iliac spine to the trochanteric line Pubofemoral ligament: acetabulum to lesser trochanter Ischiofemoral ligament: posterior support. Ischium to greater trochanter. Blood supply Medial circumflex femoral and lateral circumflex femoral arteries (Branches of profunda femoris). Also from the inferior gluteal artery. These form an anastomosis and travel to up the femoral neck to supply the head.

Answer 1137

This is a classical description of a femoral nerve injury. Femoral nerve Root values L2, 3, 4 Innervates Pectineus Sartorius Quadriceps femoris Vastus lateralis/medialis/intermedius Rectus femoris Branches Medial cutaneous nerve of thigh Saphenous nerve Intermediate cutaneous nerve of thigh Path Penetrates psoas major and exits the pelvis by passing under the inguinal ligament to enter the femoral triangle, lateral to the femoral artery and vein. Mnemonic for femoral nerve supply (don't) M I S V Q Scan for PE M edial cutaneous nerve of the thigh I ntermediate cutaneous nerve of the thigh S aphenous nerve V astus Q uadriceps femoris S artorius PE ectineus

Answer 1138

LEARN THIS! Mnemonic for the assessment of the severity of pancreatitis: PANCREAS (Ann R Coll Surg Engl 2000; 82: 16-17 P a02 < 60 mmHg A ge > 55 years N eutrophils > 15 x 10/l C alcium < 2 mmol/l R aised urea > 16 mmol/l E nzyme (lactate dehydrogenase) > 600 units/l A lbumin < 32 g/l S ugar (glucose) > 10 mmol/l > 3 positive criteria indicates severe pancreatitis. Acute early fluid collections are seen in 25% of patients with pancreatitis and require no specific treatment. Attempts at drainage may introduce infection and result in pancreatic abscess formation. Management of Pancreatitis Management of Acute Pancreatitis in the UK Diagnosis Traditionally hyperamylasaemia has been utilised with amylase being elevated three times the normal range. However, amylase may give both false positive and negative results. Serum lipase is both more sensitive and specific than serum amylase. It also has a longer half life. Serum amylase levels do not correlate with disease severity. Differential causes of hyperamylasaemia Acute pancreatitis Pancreatic pseudocyst Mesenteric infarct Perforated viscus Acute cholecystitis Diabetic ketoacidosis Assessment of severity Glasgow, Ranson scoring systems and APACHE II Biochemical scoring e.g. using CRP Features that may predict a severe attack within 48 hours of admission to hospital Initial assessment Clinical impression of severity Body mass index >30 Pleural effusion APACHE score >8 24 hours after admission Clinical impression of severity APACHE II >8 Glasgow score of 3 or more Persisting multiple organ failure CRP>150 48 hours after admission Glasgow Score of >3 CRP >150 Persisting or progressive organ failure Table adapted from UK guidelines for management of acute pancreatitis. GUT 2005, 54 suppl III Management Nutrition There is reasonable evidence to suggest that the use of enteral nutrition does not worsen the outcome in pancreatitis Most trials to date were underpowered to demonstrate a conclusive benefit. The rationale behind feeding is that it helps to prevent bacterial translocation from the gut, thereby contributing to the development of infected pancreatic necrosis. Use of antibiotic therapy Many UK surgeons administer antibiotics to patients with acute pancreatitis. However, there is very little evidence to support this practice. A recent Cochrane review highlights the potential benefits of administering Imipenem to patients with established pancreatic necrosis in the hope of averting the progression to infection. There are concerns that the administration of antibiotics in mild attacks of pancreatitis will not affect outcome and may contribute to antibiotic resistance and increase the risks of antibiotic associated diarrhoea. Surgery Patients with acute pancreatitis due to gallstones should undergo early cholecystectomy. Patients with obstructed biliary system due to stones should undergo early ERCP. Patients with extensive necrosis where infection is suspected should usually undergo FNA for culture. Patients with infected necrosis should undergo either radiological drainage or surgical necrosectomy. The choice of procedure depends upon local expertise. References www.bsg.org.uk/pdfworddocs/pancreatic.pdf Antibiotic therapy for prophylaxis against infection of pancreatic necrosis in acute pancreatitis. Villatoro et al. Cochrane Library DOI: 10.1002/14651858.CD002941.pub3. 2010 version.

Answer 1139

Unfortunately, lymphoedema may complicate redo varicose vein surgery (in 0.5% of cases). As the presentation is mild, she should be managed using compression hosiery. Diuretics do not help in cases of true lymphoedema and a dramatic response suggests an alternative underlying cause. Lymphoedema - Due to impaired lymphatic drainage in the presence of normal capillary function. Lymphoedema causes the accumulation of protein rich fluid, subdermal fibrosis and dermal thickening. Characteristically fluid is confined to the epifascial space (skin and subcutaneous tissues); muscle compartments are free of oedema. It involves the foot, unlike other forms of oedema. There may be a 'buffalo hump' on the dorsum of the foot and the skin cannot be pinched due to subcutaneous fibrosis. Causes of lymphoedema Primary Congenital < 1 year: sporadic, Milroy's disease Onset 1-35 years: sporadic, Meige's disease > 35 years: Tarda Secondary Bacterial/fungal/parasitic infection (filariasis) Lymphatic malignancy Radiotherapy to lymph nodes Surgical resection of lymph nodes DVT Thrombophlebitis Indications for surgery Marked disability or deformity from limb swelling Lymphoedema caused by proximal lymphatic obstruction with patent distal lymphatics suitable for a lymphatic drainage procedure Lymphocutaneous fistulae and megalymphatics Procedures Homans operation Reduction procedure with preservation of overlying skin (which must be in good condition). Skin flaps are raised and the underlying tissue excised. Limb circumference typically reduced by a third. Charles operation All skin and subcutaneous tissue around the calf are excised down to the deep fascia. Split skin grafts are placed over the site. May be performed if overlying skin is not in good condition. Larger reduction in size than with Homans procedure. Lymphovenous anastamosis Identifiable lymphatics are anastomosed to sub dermal venules. Usually indicated in 2% of patients with proximal lymphatic obstruction and normal distal lymphatics.

Answer 1140

Leydig cell tumours are rare testicular sex cord stromal tumours (which also include sertoli cell tumours) which are associated with hormonal activity. Patients with Leydig cell tumours may present with gynaecomastia before they notice testicular enlargement. Majority are benign Histology: eosinophilic cells in columns Testicular disorders Testicular cancer Testicular cancer is the most common malignancy in men aged 20-30 years. Around 95% of cases of testicular cancer are germ-cell tumours. Germ cell tumours may essentially be divided into: Tumour type Key features Tumour markers Pathology Seminoma Commonest subtype (50%) Average age at diagnosis = 40 Even advanced disease associated with 5 year survival of 73% AFP usually normal HCG elevated in 10% seminomas Lactate dehydrogenase; elevated in 10-20% seminomas (but also in many other conditions) Sheet like lobular patterns of cells with substantial fibrous component. Fibrous septa contain lymphocytic inclusions and granulomas may be seen. Non seminomatous germ cell tumours (42%) Teratoma Yolk sac tumour Choriocarcinoma Mixed germ cell tumours (10%) Younger age at presentation =20-30 years Advanced disease carries worse prognosis (48% at 5 years) Retroperitoneal lymph node dissection may be needed for residual disease after chemotherapy AFP elevated in up to 70% of cases HCG elevated in up to 40% of cases Other markers rarely helpful Heterogenous texture with occasional ectopic tissue such as hair Risk factors for testicular cancer Cryptorchidism Infertility Family history Klinefelter's syndrome Mumps orchitis Features A painless lump is the most common presenting symptom Pain may also be present in a minority of men Other possible features include hydrocele, gynaecomastia Diagnosis Ultrasound is first-line CT scanning of the chest/ abdomen and pelvis is used for staging Tumour markers (see above) should be measured Management Orchidectomy (Inguinal approach) Chemotherapy and radiotherapy may be given depending on staging Abdominal lesions >1cm following chemotherapy may require retroperitoneal lymph node dissection. Prognosis is generally excellent 5 year survival for seminomas is around 95% if Stage I 5 year survival for teratomas is around 85% if Stage I Benign disease Epididymo-orchitis Acute epididymitis is an acute inflammation of the epididymis, often involving the testis and usually caused by bacterial infection. Infection spreads from the urethra or bladder. In men <35 years, gonorrhoea or chlamydia are the usual infections. Amiodarone is a recognised non infective cause of epididymitis, which resolves on stopping the drug. Tenderness is usually confined to the epididymis, which may facilitate differentiating it from torsion where pain usually affects the entire testis. Testicular torsion Twist of the spermatic cord resulting in testicular ischaemia and necrosis. Most common in males aged between 10 and 30 (peak incidence 13-15 years) Pain is usually severe and of sudden onset. Cremasteric reflex is lost and elevation of the testis does not ease the pain. Treatment is with surgical exploration. If a torted testis is identified then both testis should be fixed as the condition of bell clapper testis is often bilateral. Hydrocele Presents as a mass that transilluminates, usually possible to 'get above' it on examination. In younger men it should be investigated with USS to exclude tumour. In children it may occur as a result of a patent processus vaginalis. Treatment in adults is with a Lords or Jabouley procedure. Treatment in children is with trans inguinal ligation of PPV.

Answer 1141

Cyclophosphamide is metabolised into a toxic metabolite acrolein. The effects may be attenuated by administration of large volumes of intravenous fluids and mesna (which neutralises the metabolite). The condition may be managed initially by bladder catheterisation and irrigation. Haematuria Causes of haematuria Trauma Injury to renal tract Renal trauma commonly due to blunt injury (others penetrating injuries) Ureter trauma rare: iatrogenic Bladder trauma: due to RTA or pelvic fractures Infection Remember TB Malignancy Renal cell carcinoma (remember paraneoplastic syndromes): painful or painless Urothelial malignancies: 90% are transitional cell carcinoma, can occur anywhere along the urinary tract. Painless haematuria. Squamous cell carcinoma and adenocarcinoma: rare bladder tumours Prostate cancer Penile cancers: SCC Renal disease Glomerulonephritis Stones Microscopic haematuria common Structural abnormalities Benign prostatic hyperplasia (BPH) causes haematuria due to hypervascularity of the prostate gland Cystic renal lesions e.g. polycystic kidney disease Vascular malformations Renal vein thrombosis due to renal cell carcinoma Coagulopathy Causes bleeding of underlying lesions Drugs Cause tubular necrosis or interstitial nephritis: aminoglycosides, chemotherapy Interstitial nephritis: penicillin, sulphonamides, and NSAIDs Anticoagulants Benign Exercise Gynaecological Endometriosis: flank pain, dysuria, and haematuria that is cyclical Iatrogenic Catheterisation Radiotherapy; cystitis, severe haemorrhage, bladder necrosis Pseudohaematuria For example following consumption of beetroot References Http://bestpractice.bmj.com/best-practice/monograph/316/overview/aetiology.html

Answer 1142

Forearm fractures may be complicated by neurovascular compromise. The anterior interosseous nerve may be affected. It has no sensory supply so the defect is motor alone. Anterior interosseous nerve The anterior interosseous nerve (volar interosseous nerve) is a branch of the median nerve that supplies the deep muscles on the front of the forearm, except the ulnar half of the flexor digitorum profundus. It accompanies the anterior interosseous artery along the anterior of the interosseous membrane of the forearm, in the interval between the flexor pollicis longus and flexor digitorum profundus, supplying the whole of the former and (most commonly) the radial half of the latter, and ending below in the pronator quadratus and wrist joint. Innervation The anterior interosseous nerve classically innervates 2.5 muscles: Flexor pollicis longus Pronator quadratus The radial half of flexor digitorum profundus (the lateral two out of the four tendons). These muscles are in the deep level of the anterior compartment of the forearm.

Answer 1143

The clavipectoral fascia is situated under the clavicular portion of pectoralis major. It protects both the axillary vessels and nodes. During an axillary node clearance for breast cancer the clavipectoral fascia is incised and this allows access to the nodal stations. The nodal stations are; level 1 nodes inferior to pectoralis minor, level 2 lie behind it and level 3 above it. During a Patey Mastectomy surgeons divide pectoralis minor to gain access to level 3 nodes. The use of sentinel node biopsy (and stronger assistants!) have made this procedure far less common. Axilla Boundaries of the axilla Medially Chest wall and Serratus anterior Laterally Humeral head Floor Subscapularis Anterior aspect Lateral border of Pectoralis major Fascia Clavipectoral fascia Content: Long thoracic nerve (of Bell) Derived from C5-C7 and passes behind the brachial plexus to enter the axilla. It lies on the medial chest wall and supplies serratus anterior. Its location puts it at risk during axillary surgery and damage will lead to winging of the scapula. Thoracodorsal nerve and thoracodorsal trunk Innervate and vascularise latissimus dorsi. Axillary vein Lies at the apex of the axilla, it is the continuation of the basilic vein. Becomes the subclavian vein at the outer border of the first rib. Intercostobrachial nerves Traverse the axillary lymph nodes and are often divided during axillary surgery. They provide cutaneous sensation to the axillary skin. Lymph nodes The axilla is the main site of lymphatic drainage for the breast.

Answer 1144

Routine use of antibiotics is not advised as this may predispose to resistant organisms. Pentoxifylline was subjected to a Cochrane review in 2007 and shown to improve healing rates. Lower leg ulcers Venous leg ulcers Most due to venous hypertension, secondary to chronic venous insufficiency (other causes include calf pump dysfunction or neuromuscular disorders) Ulcers form due to capillary fibrin cuff or leucocyte sequestration Features of venous insufficiency include oedema, brown pigmentation, lipodermatosclerosis, eczema Location above the ankle, painless Deep venous insufficiency is related to previous DVT and superficial venous insufficiency is associated with varicose veins Doppler ultrasound looks for presence of reflux and duplex ultrasound looks at the anatomy/ flow of the vein Management: 4 layer compression banding after exclusion of arterial disease or surgery If fail to heal after 12 weeks or >10cm2 skin grafting may be needed Marjolin's ulcer Squamous cell carcinoma Occurring at sites of chronic inflammation e.g; burns, osteomyelitis after 10-20 years Mainly occur on the lower limb Arterial ulcers Occur on the toes and heel Painful There may be areas of gangrene Cold with no palpable pulses Low ABPI measurements Neuropathic ulcers Commonly over plantar surface of metatarsal head and plantar surface of hallux The plantar neuropathic ulcer is the condition that most commonly leads to amputation in diabetic patients Due to pressure Management includes cushioned shoes to reduce callus formation Pyoderma gangrenosum Associated with inflammatory bowel disease/RA Can occur at stoma sites Erythematous nodules or pustules which ulcerate

Answer 1145

It is standard practice to administer a sedative drug prior to achieving paralysis. Ketamine causes the least haemodynamic instability and would usually be used first. A paralysing agent is then used. Anaesthetic agents The table below summarises some of the more commonly used IV induction agents Agent Specific features Propofol Rapid onset of anaesthesia Pain on IV injection Rapidly metabolised with little accumulation of metabolites Proven anti emetic properties Moderate myocardial depression Widely used especially for maintaining sedation on ITU, total IV anaesthesia and for daycase surgery Sodium thiopentone Extremely rapid onset of action making it the agent of choice for rapid sequence of induction Marked myocardial depression may occur Metabolites build up quickly Unsuitable for maintenance infusion Little analgesic effects Ketamine May be used for induction of anaesthesia Has moderate to strong analgesic properties Produces little myocardial depression making it a suitable agent for anaesthesia in those who are haemodynamically unstable May induce state of dissociative anaesthesia resulting in nightmares Etomidate Has favorable cardiac safety profile with very little haemodynamic instability No analgesic properties Unsuitable for maintaining sedation as prolonged (and even brief) use may result in adrenal suppression Post operative vomiting is common

Answer 1146

Osteosarcoma may complicate Pagets disease of bone in up to 10% cases. Radiological appearances include bone destruction coupled with new bone formation, periosteal elevation may also occur. Surgical resection is the main treatment. Sarcomas Malignant tumours of mesenchymal origin Types May be either bone or soft tissue in origin. Bone sarcoma include: Osteosarcoma Ewings sarcoma (although non bony sites recognised) Chondrosarcoma - originate from Chondrocytes Soft tissue sarcoma are a far more heterogeneous group and include: Liposarcoma-adipocytes Rhabdomyosarcoma-striated muscle Leiomyosarcoma-smooth muscle Synovial sarcomas- close to joints (cell of origin not known but not synovium) Malignant fibrous histiocytoma is now referred to as undifferentiated pleomorphic sarcoma. Careful histological assessment of lesions now allows more accurate categorisation of sarcoma subtypes than was previously possible. Features Certain features of a mass or swelling should raise suspicion for a sarcoma these include: Large >5cm soft tissue mass Deep tissue location or intra muscular location Rapid growth Painful lump Assessment Imaging of suspicious masses should utilise a combination of MRI, CT and USS. Blind biopsy should not be performed prior to imaging and where required should be done in such a way that the biopsy tract can be subsequently included in any resection. Ewings sarcoma Commoner in males Incidence of 0.3 / 1, 000, 000 Onset typically between 10 and 20 years of age Location by femoral diaphysis is commonest site Histologically it is a small round tumour Blood borne metastasis is common and chemotherapy is often combined with surgery Osteosarcoma Mesenchymal cells with osteoblastic differentiation 20% of all primary bone tumours Incidence of 5 per 1,000,000 Peak age 15-30, commoner in males Limb preserving surgery may be possible and many patients will receive chemotherapy Liposarcoma Malignancy of adipocytes Rare, approximately 2.5 per 1,000,000. They are the most common soft tissue sarcoma Typically located in deep locations such as retroperitoneum Affect older age group usually >40 years of age May be well differentiated and thus slow growing although may undergo de-differentiation and disease progression Many tumours will have a pseudocapsule that can misleadingly allow surgeons to feel that they can 'shell out' these lesions. In reality, tumour may invade at the edge of the pseudocapsule and result in local recurrence if this strategy is adopted Usually resistant to radiotherapy, although this is often used in a palliative setting Malignant Fibrous Histiocytoma Tumour with large number of histiocytes Also described as undifferentiated pleomorphic sarcoma NOS (i.e. Cell of origin is not known) Four major subtypes are recognised: storiform-pleomorphic (70% cases), myxoid (less aggressive), giant cell and inflammatory Treatment is usually with surgical resection and adjuvant radiotherapy as this reduces the likelihood of local recurrence

Answer 1147

During endoscopic procedures, many patients have conscious sedation and retain decision making ability. If they request the procedure to be stopped this must be adhered to. Consent There are 3 types of consent: 1. Informed 2. Expressed 3. Implied Consent forms used in UK NHS Consent Form 1 For competent adults who are able to consent for themselves where consciousness may be impaired (e.g. GA) Consent Form 2 For an adult consenting on behalf of a child where consciousness is impaired Consent Form 3 For an adult or child where consciousness is not impaired Consent Form 4 For adults who lack capacity to provide informed consent Capacity Key points include: 1. Understand and retain information 2. Patient believes the information to be true 3. Patient is able to weigh the information to make a decision All patients must be assumed to have capacity Consent in minors Young children and older children who are not Gillick competent cannot consent for themselves. In British law the patients biological mother can always provide consent. The child's father can consent if the parents are married (and the father is the biological father), or if the father is named on the birth certificate (irrespective of marital status). If parents are not married and the father is not named on the birth certificate then the father cannot consent.

Answer 1148

Whilst many of these nerves can be injured in hip surgery, for a foot drop to develop in this context (i.e. revision THR), the sciatic nerve is the most likely. Sciatic nerve The sciatic nerve is formed from the sacral plexus and is the largest nerve in the body. It is the continuation of the main part of the plexus arising from ventral rami of L4 to S3. These rami converge at the inferior border of piriformis to form the nerve itself. It passes through the inferior part of the greater sciatic foramen and emerges beneath piriformis. Medially, lie the inferior gluteal nerve and vessels and the pudendal nerve and vessels. It runs inferolaterally under the cover of gluteus maximus midway between the greater trochanter and ischial tuberosity. It receives its blood supply from the inferior gluteal artery. The nerve provides cutaneous sensation to the skin of the foot and the leg. It also innervates the posterior thigh muscles and the lower leg and foot muscles. The nerve splits into the tibial and common peroneal nerves approximately half way down the posterior thigh. The tibial nerve supplies the flexor muscles and the common peroneal nerve supplies the extensor muscles and the evertor muscles of the foot. Summary points Origin Spinal nerves L4 - S3 Articular Branches Hip joint Muscular branches in upper leg Semitendinosus Semimembranosus Biceps femoris Part of adductor magnus Cutaneous sensation Posterior aspect of thigh (via cutaneous nerves) Gluteal region Entire lower leg (except the medial aspect) Terminates At the upper part of the popliteal fossa by dividing into the tibial and peroneal nerves The nerve to the short head of the biceps femoris comes from the common peroneal part of the sciatic and the other muscular branches arise from the tibial portion. The tibial nerve goes on to innervate all muscles of the foot except the extensor digitorum brevis (which is innervated by the common peroneal nerve).

Answer 1149

The cremasteric reflex is usually preserved when the torsion affects the appendage only. Testicular disorders Testicular cancer Testicular cancer is the most common malignancy in men aged 20-30 years. Around 95% of cases of testicular cancer are germ-cell tumours. Germ cell tumours may essentially be divided into: Tumour type Key features Tumour markers Pathology Seminoma Commonest subtype (50%) Average age at diagnosis = 40 Even advanced disease associated with 5 year survival of 73% AFP usually normal HCG elevated in 10% seminomas Lactate dehydrogenase; elevated in 10-20% seminomas (but also in many other conditions) Sheet like lobular patterns of cells with substantial fibrous component. Fibrous septa contain lymphocytic inclusions and granulomas may be seen. Non seminomatous germ cell tumours (42%) Teratoma Yolk sac tumour Choriocarcinoma Mixed germ cell tumours (10%) Younger age at presentation =20-30 years Advanced disease carries worse prognosis (48% at 5 years) Retroperitoneal lymph node dissection may be needed for residual disease after chemotherapy AFP elevated in up to 70% of cases HCG elevated in up to 40% of cases Other markers rarely helpful Risk factors for testicular cancer Cryptorchidism Infertility Family history Klinefelter's syndrome Mumps orchitis Features A painless lump is the most common presenting symptom Pain may also be present in a minority of men Other possible features include hydrocele, gynaecomastia Diagnosis Ultrasound is first-line CT scanning of the chest/ abdomen and pelvis is used for staging Tumour markers (see above) should be measured Management Orchidectomy (Inguinal approach) Chemotherapy and radiotherapy may be given depending on staging Abdominal lesions >1cm following chemotherapy may require retroperitoneal lymph node dissection. Prognosis is generally excellent 5 year survival for seminomas is around 95% if Stage I 5 year survival for teratomas is around 85% if Stage I Benign disease Epididymo-orchitis Acute epididymitis is an acute inflammation of the epididymis, often involving the testis and usually caused by bacterial infection. Infection spreads from the urethra or bladder. In men <35 years, gonorrhoea or chlamydia are the usual infections. Amiodarone is a recognised non infective cause of epididymitis, which resolves on stopping the drug. Tenderness is usually confined to the epididymis, which may facilitate differentiating it from torsion where pain usually affects the entire testis. Testicular torsion Twist of the spermatic cord resulting in testicular ischaemia and necrosis. Most common in males aged between 10 and 30 (peak incidence 13-15 years) Pain is usually severe and of sudden onset. Cremasteric reflex is lost and elevation of the testis does not ease the pain. Treatment is with surgical exploration. If a torted testis is identified then both testis should be fixed as the condition of bell clapper testis is often bilateral. Hydrocele Presents as a mass that transilluminates, usually possible to 'get above' it on examination. In younger men it should be investigated with USS to exclude tumour. In children it may occur as a result of a patent processus vaginalis. Treatment in adults is with a Lords or Jabouley procedure. Treatment in children is with trans inguinal ligation of PPV.

Answer 1150

This high velocity injury can often produce significant angulation and displacement. Both of these may impair the function of the median nerve with loss of function of the muscles of the thenar eminence. Median nerve The median nerve is formed by the union of a lateral and medial root respectively from the lateral (C5,6,7) and medial (C8 and T1) cords of the brachial plexus; the medial root passes anterior to the third part of the axillary artery. The nerve descends lateral to the brachial artery, crosses to its medial side (usually passing anterior to the artery). It passes deep to the bicipital aponeurosis and the median cubital vein at the elbow. It passes between the two heads of the pronator teres muscle, and runs on the deep surface of flexor digitorum superficialis (within its fascial sheath). Near the wrist it becomes superficial between the tendons of flexor digitorum superficialis and flexor carpi radialis, deep to palmaris longus tendon. It passes deep to the flexor retinaculum to enter the palm, but lies anterior to the long flexor tendons within the carpal tunnel. Branches Region Branch Upper arm No branches, although the nerve commonly communicates with the musculocutaneous nerve Forearm Pronator teres Pronator quadratus Flexor carpi radialis Palmaris longus Flexor digitorum superficialis Flexor pollicis longus Flexor digitorum profundus (only the radial half) Distal forearm Palmar cutaneous branch Hand (Motor) Motor supply (LOAF) Lateral 2 lumbricals Opponens pollicis Abductor pollicis brevis Flexor pollicis brevis Hand (Sensory) Over thumb and lateral 2 Â½ fingers On the palmar aspect this projects proximally, on the dorsal aspect only the distal regions are innervated with the radial nerve providing the more proximal cutaneous innervation. Patterns of damage Damage at wrist e.g. carpal tunnel syndrome paralysis and wasting of thenar eminence muscles and opponens pollicis (ape hand deformity) sensory loss to palmar aspect of lateral (radial) 2 Â½ fingers Damage at elbow, as above plus: unable to pronate forearm weak wrist flexion ulnar deviation of wrist Anterior interosseous nerve (branch of median nerve) leaves just below the elbow results in loss of pronation of forearm and weakness of long flexors of thumb and index finger

Answer 1151

The abducens nerve (CN VI) has a long intra cranial course and is thus susceptible to raised intra cranial pressure. It also passes over the petrous temporal bone and 6th nerve palsies are also seen in mastoiditis. Cranial nerves Cranial nerve lesions Olfactory nerve May be injured in basal skull fractures or involved in frontal lobe tumour extension. Loss of olfactory nerve function in relation to major CNS pathology is seldom an isolated event and thus it is poor localiser of CNS pathology. Optic nerve Problems with visual acuity may result from intra ocular disorders. Problems with the blood supply such as amaurosis fugax may produce temporary visual distortion. More important surgically is the pupillary response to light. The pupillary size may be altered in a number of disorders. Nerves involved in the resizing of the pupil connect to the pretectal nucleus of the high midbrain, bypassing the lateral geniculate nucleus and the primary visual cortex. From the pretectal nucleus neurones pass to the Edinger - Westphal nucleus, motor axons from here pass along with the oculomotor nerve. They synapse with ciliary ganglion neurones; the parasympathetic axons from this then innervate the iris and produce miosis. The miotic pupil is seen in disorders such as Horner's syndrome or opiate overdose. Mydriasis is the dilatation of the pupil in response to disease, trauma, drugs (or the dark!). It is pathological when light fails to induce miosis. The radial muscle is innervated by the sympathetic nervous system. Because the parasympathetic fibres travel with the oculomotor nerve they will be damaged by lesions affecting this nerve (e.g. cranial trauma). The response to light shone in one eye is usually a constriction of both pupils. This indicates intact direct and consensual light reflexes. When the optic nerve has an afferent defect the light shining on the affected eye will produce a diminished pupillary response in both eyes. Whereas light shone on the unaffected eye will produce a normal pupillary response in both eyes. This is referred to as the Marcus Gunn pupil and is seen in conditions such as optic neuritis. In a total CN II lesion shining the light in the affected eye will produce no response. Oculomotor nerve The pupillary effects are described above. In addition it supplies all ocular muscles apart from lateral rectus and superior oblique. Thus the affected eye will be deviated inferolaterally. Levator palpebrae superioris may also be impaired resulting in impaired ability to open the eye. Trochlear nerve The eye will not be able to look down. Trigeminal nerve Largest cranial nerve. Exits the brainstem at the pons. Branches are ophthalmic, maxillary and mandibular. Only the mandibular branch has both sensory and motor fibres. Branches converge to form the trigeminal ganglion (located in Meckels cave). It supplies the muscles of mastication and also tensor veli palatine, mylohyoid, anterior belly of digastric and tensor tympani. The detailed descriptions of the various sensory functions are described in other areas of the website. The corneal reflex is important and is elicited by applying a small tip of cotton wool to the cornea, a reflex blink should occur if it is intact. It is mediated by: the naso ciliary branch of the ophthalmic branch of the trigeminal (sensory component) and the facial nerve producing the motor response. Lesions of the afferent arc will produce bilateral absent blink and lesions of the efferent arc will result in a unilateral absent blink. Abducens nerve The affected eye will have a deficit of abduction. This cranial nerve exits the brainstem between the pons and medulla. It thus has a relatively long intra cranial course which renders it susceptible to damage in raised intra cranial pressure. Facial nerve Emerges from brainstem between pons and medulla. It controls muscles of facial expression and taste from the anterior 2/3 of the tongue. The nerve passes into the petrous temporal bone and into the internal auditory meatus. It then passes through the facial canal and exits at the stylomastoid foramen. It passes through the parotid gland and divides at this point. It does not innervate the parotid gland. Its divisions are considered in other parts of the website. Its motor fibres innervate orbicularis oculi to produce the efferent arm of the corneal reflex. In surgical practice it may be injured during parotid gland surgery or invaded by malignancies of the gland and a lower motor neurone on the ipsilateral side will result. Vestibulo-cochlear nerve Exits from the pons and then passes through the internal auditory meatus. It is implicated in sensorineural hearing loss. Individuals with sensorineural hearing loss will localise the sound in webers test to the normal ear. Rinnes test will be reduced on the affected side but should still work. These two tests will distinguish sensorineural hearing loss from conductive deafness. In the latter condition webers test will localise to the affected ear and Rinnes test will be impaired on the affected side. Surgical lesions affecting this nerve include CNS tumours and basal skull fractures. It may also be damaged by the administration of ototoxic drugs (of which gentamicin is the most commonly used in surgical practice). Glossopharyngeal nerve Exits the pons just above the vagus. Receives sensory fibres from posterior 1/3 tongue, tonsils, pharynx and middle ear (otalgia may occur following tonsillectomy). It receives visceral afferents from the carotid bodies. It supplies parasympathetic fibres to the parotid gland via the otic ganglion and motor function to stylopharyngeaus muscle. The sensory function of the nerve is tested using the gag reflex. Vagus nerve Leaves the medulla between the olivary nucleus and the inferior cerebellar peduncle. Passes through the jugular foramen and into the carotid sheath. Details of the functions of the vagus nerve are covered in the website under relevant organ sub headings. Accessory nerve Exists from the caudal aspect of the brainstem (multiple branches) supplies trapezius and sternocleidomastoid muscles. The distal portion of this nerve is most prone to injury during surgical procedures. Hypoglossal nerve Emerges from the medulla at the preolivary sulcus, passes through the hypoglossal canal. It lies on the carotid sheath and passes deep to the posterior belly of digastric to supply muscles of the tongue (except palatoglossus). Its location near the carotid sheath makes it vulnerable during carotid endarterectomy surgery and damage will produce ipsilateral defect in muscle function.

Answer 1152

Muscles of the deep posterior compartment: Tibialis posterior Flexor hallucis longus Flexor digitorum longus Popliteus The plantaris muscle lies within the superficial posterior compartment of the lower leg. Lower limb- Muscular compartments Anterior compartment Muscle Nerve Action Tibialis anterior Deep peroneal nerve Dorsiflexes ankle joint, inverts foot Extensor digitorum longus Deep peroneal nerve Extends lateral four toes, dorsiflexes ankle joint Peroneus tertius Deep peroneal nerve Dorsiflexes ankle, everts foot Extensor hallucis longus Deep peroneal nerve Dorsiflexes ankle joint, extends big toe Peroneal compartment Muscle Nerve Action Peroneus longus Superficial peroneal nerve Everts foot, assists in plantar flexion Peroneus brevis Superficial peroneal nerve Plantar flexes the ankle joint Superficial posterior compartment Nerve Action Gastrocnemius Tibial nerve Plantar flexes the foot, may also flex the knee Soleus Tibial nerve Plantar flexor Deep posterior compartment Muscle Nerve Action Flexor digitorum longus Tibial Flexes the lateral four toes Flexor hallucis longus Tibial Flexes the great toe Tibialis posterior Tibial Plantar flexor, inverts the foot

Answer 1153

Ventricular tachycardia - verapamil is contraindicated Verapamil should never be given to a patient with a broad complex tachycardia as it may precipitate ventricular fibrillation in patients with ventricular tachycardia. Adenosine is sometimes given in this situation as a 'trial' if there is a strong suspicion the underlying rhythm is a supraventricular tachycardia with aberrant conduction Ventricular tachycardia: management Whilst a broad complex tachycardia may result from a supraventricular rhythm with aberrant conduction, the European Resuscitation Council advise that in a peri-arrest situation it is assumed to be ventricular in origin If the patient has adverse signs (systolic BP < 90 mmHg, chest pain, heart failure or rate > 150 beats/min) then immediate cardioversion is indicated. In the absence of such signs antiarrhythmics may be used. If these fail, then electrical cardioversion may be needed with synchronised DC shocks Drug therapy amiodarone: ideally administered through a central line lidocaine: use with caution in severe left ventricular impairment procainamide Verapamil should NOT be used in VT If drug therapy fails electrophysiological study (EPS) implant able cardioverter-defibrillator (ICD) - this is particularly indicated in patients with significantly impaired LV function

Answer 1154

The radial nerve supplies the extensor muscle group. Radial nerve Continuation of posterior cord of the brachial plexus (root values C5 to T1) Path In the axilla: lies posterior to the axillary artery on subscapularis, latissimus dorsi and teres major. Enters the arm between the brachial artery and the long head of triceps (medial to humerus). Spirals around the posterior surface of the humerus in the groove for the radial nerve. At the distal third of the lateral border of the humerus it then pierces the intermuscular septum and descends in front of the lateral epicondyle. At the lateral epicondyle it lies deeply between brachialis and brachioradialis where it then divides into a superficial and deep terminal branch. Deep branch crosses the supinator to become the posterior interosseous nerve. Regions innervated Motor (main nerve) Triceps Anconeus Brachioradialis Extensor carpi radialis Motor (posterior interosseous branch) Supinator Extensor carpi ulnaris Extensor digitorum Extensor indicis Extensor digiti minimi Extensor pollicis longus and brevis Abductor pollicis longus Sensory The area of skin supplying the proximal phalanges on the dorsal aspect of the hand is supplied by the radial nerve (this does not apply to the little finger and part of the ring finger) Muscular innervation and effect of denervation Anatomical location Muscle affected Effect of paralysis Shoulder Long head of triceps Minor effects on shoulder stability in abduction Arm Triceps Loss of elbow extension Forearm Supinator Brachioradialis Extensor carpi radialis longus and brevis Weakening of supination of prone hand and elbow flexion in mid prone position

Answer 1155

It decreases the rate of gastric emptying. Gastric secretions A working knowledge of gastric secretions is important for surgery because peptic ulcers are common, surgeons frequently prescribe anti secretory drugs and because there are still patients around who will have undergone acid lowering procedures (Vagotomy) in the past. Gastric acid Is produced by the parietal cells in the stomach pH of gastric acid is around 2 with acidity being maintained by the H+/K+ ATP ase pump. As part of the process bicarbonate ions will be secreted into the surrounding vessels. Sodium and chloride ions are actively secreted from the parietal cell into the canaliculus. This sets up a negative potential across the membrane and as a result sodium and potassium ions diffuse across into the canaliculus. Carbonic anhydrase forms carbonic acid which dissociates and the hydrogen ions formed by dissociation leave the cell via the H+/K+ antiporter pump. At the same time sodium ions are actively absorbed. This leaves hydrogen and chloride ions in the canaliculus these mix and are secreted into the lumen of the oxyntic gland. Phases of gastric acid secretion There are 3 phases of gastric secretion: 1. Cephalic phase (smell / taste of food) 30% acid produced Vagal cholinergic stimulation causing secretion of HCL and gastrin release from G cells 2. Gastric phase (distension of stomach ) 60% acid produced Stomach distension/low H+/peptides causes Gastrin release 3. Intestinal phase (food in duodenum) 10% acid produced High acidity/distension/hypertonic solutions in the duodenum inhibits gastric acid secretion via enterogastrones (CCK, secretin) and neural reflexes. Regulation of gastric acid production Factors increasing production include: Vagal nerve stimulation Gastrin release Histamine release (indirectly following gastrin release) from enterchromaffin like cells Factors decreasing production include: Somatostatin (inhibits histamine release) Cholecystokinin Secretin Below is a brief summary of the major hormones involved in food digestion: Source Stimulus Actions Gastrin G cells in antrum of the stomach Distension of stomach, extrinsic nerves Inhibited by: low antral pH, somatostatin Increase HCL, pepsinogen and IF secretion, increases gastric motility, trophic effect on gastric mucosa CCK I cells in upper small intestine Partially digested proteins and triglycerides Increases secretion of enzyme-rich fluid from pancreas, contraction of gallbladder and relaxation of sphincter of Oddi, decreases gastric emptying, trophic effect on pancreatic acinar cells, induces satiety Secretin S cells in upper small intestine Acidic chyme, fatty acids Increases secretion of bicarbonate-rich fluid from pancreas and hepatic duct cells, decreases gastric acid secretion, trophic effect on pancreatic acinar cells VIP Small intestine, pancreas Neural Stimulates secretion by pancreas and intestines, inhibits acid and pepsinogen secretion Somatostatin D cells in the pancreas and stomach Fat, bile salts and glucose in the intestinal lumen Decreases acid and pepsin secretion, decreases gastrin secretion, decreases pancreatic enzyme secretion, decreases insulin and glucagon secretion inhibits trophic effects of gastrin, stimulates gastric mucous production

Answer 1156

E- Potassium sparing diuretics Potassium-sparing diuretics may be divided into the epithelial sodium channel blockers (amiloride and triamterene) and aldosterone antagonists (spironolactone and eplerenone). Amiloride is a weak diuretic which blocks the epithelial sodium channel in the distal convoluted tubule. Usually given with thiazides or loop diuretics as an alternative to potassium supplementation. Spironolactone is an aldosterone antagonist which acts at in the distal convoluted tubule. Indications ascites: patients with cirrhosis develop a secondary hyperaldosteronism. Relatively large doses such as 100 or 200mg are often used heart failure nephrotic syndrome Conn's syndrome

Answer 1157

This will minimise thermal trauma to the recurrent laryngeal nerve Diathermy - Diathermy devices are used by surgeons in all branches of surgery. Use electric currents to produce local heat and thereby facilitate haemostasis or surgical dissection. Consist of a generator unit that is located outside the patient and can be set to the level of power required by the surgeon. There are two major types of diathermy machine; Monopolar The current flows through the diathermy unit into a handheld device that is controlled by the surgeon. Electricity can flow from the tip of the device into the patient. The earth electrode is located some distance away. The relatively narrow tip of the diathermy device produces local heat and this can be used to vaporise and fulgurate tissues. The current can be adjusted in terms of frequency so that different actions can be effected. In cutting mode sufficient power is applied to the tissues to vaporise their water content. In coagulation mode the power level is reduced so that a coagulum is formed instead. Some diathermy machines can utilise a setting known as blend that alternates cutting and coagulation functions, these tend to be used during procedures such as colonoscopic polypectomy. Bipolar The electric current flows from one electrode to another however, both electrodes are usually contained within the same device e.g. a pair of forceps. The result is that heating is localised to the area between the two electrodes and surrounding tissue damage is minimised. Ultrasound based devices These include CUSA and Harmonic scalpel. They generate high frequency oscillations that seal and coagulate tissues. They have different energy settings that allow them to dissect and simultaneously seal vessels if required. The CUSA device leaves vessels intact that may then be divided. Ligasure device Delivers tailored energy levels to allow simultaneous haemostasis and dissection. The device senses the impedance of the tissues and tailors energy levels accordingly. Hazards of diathermy Inadvertent patient burn. This may result of careless handling of the device or in the case of monopolar devices forgetting to apply a return electrode plate, In this situation patients may develop a contact burn when electricity flows to earth Explosion or fire. This may occur when volatile anaesthetic gases or skin preparation fluid have been used

Answer 1158

Facial. Damage to the nerve in the bony canal may result in impaired innervation to stapedius and therefore sounds are no longer dampened. Another cause of hyperacusis is increased activity in the tensor tympani muscle, this is innervated by the trigeminal nerve. Facial nerve The facial nerve is the main nerve supplying the structures of the second embryonic branchial arch. It is predominantly an efferent nerve to the muscles of facial expression, digastric muscle and also to many glandular structures. It contains a few afferent fibres which originate in the cells of its genicular ganglion and are concerned with taste. Supply - 'face, ear, taste, tear' Face: muscles of facial expression Ear: nerve to stapedius Taste: supplies anterior two-thirds of tongue Tear: parasympathetic fibres to lacrimal glands, also salivary glands Path Subarachnoid path Origin: motor- pons, sensory- nervus intermedius Pass through the petrous temporal bone into the internal auditory meatus with the vestibulocochlear nerve. Here they combine to become the facial nerve. Facial canal path The canal passes superior to the vestibule of the inner ear At the medial aspect of the middle ear, it becomes wider and contains the geniculate ganglion. - 3 branches: 1. greater petrosal nerve 2. nerve to stapedius 3. chorda tympani Stylomastoid foramen Passes through the stylomastoid foramen (tympanic cavity anterior and mastoid antrum posteriorly) Posterior auricular nerve and branch to posterior belly of digastric and stylohyoid muscle Face Enters parotid gland and divides into 5 branches: Temporal branch Zygomatic branch Buccal branch Marginal mandibular branch Cervical branch

Answer 1159

The thoracic duct lies posterior to the oesophagus and passes to the left at the level of the Angle of Louis. It enters the thorax at T12 alongside with the aorta. Thoracic duct Continuation of the cisterna chyli in the abdomen. Enters the thorax at T12. Lies posterior to the oesophagus for most of its intrathoracic course. Passes to the left at T5. Lymphatics draining the left side of the head and neck join the thoracic duct prior to its insertion into the junction between left subclavian and internal jugular veins. Lymphatics draining the right side of the head and neck drain via the subclavian and jugular trunks into the right lymphatic duct and thence into the mediastinal trunk and eventually the right brachiocephalic vein. Its location in the thorax makes it prone to injury during oesophageal surgery. Some surgeons administer cream to patients prior to oesophagectomy so that it is easier to identify the cut ends of the duct.

Answer 1160

The intercostobrachial nerves traverse the axilla and innervate the overlying skin. These can be injured or divided during axillary surgery and the result is anaesthesia of the overlying skin. Axilla Boundaries of the axilla Medially Chest wall and Serratus anterior Laterally Humeral head Floor Subscapularis Anterior aspect Lateral border of Pectoralis major Fascia Clavipectoral fascia Content: Long thoracic nerve (of Bell) Derived from C5-C7 and passes behind the brachial plexus to enter the axilla. It lies on the medial chest wall and supplies serratus anterior. Its location puts it at risk during axillary surgery and damage will lead to winging of the scapula. Thoracodorsal nerve and thoracodorsal trunk Innervate and vascularise latissimus dorsi. Axillary vein Lies at the apex of the axilla, it is the continuation of the basilic vein. Becomes the subclavian vein at the outer border of the first rib. Intercostobrachial nerves Traverse the axillary lymph nodes and are often divided during axillary surgery. They provide cutaneous sensation to the axillary skin. Lymph nodes The axilla is the main site of lymphatic drainage for the breast.

Answer 1161

Pyrexia is the most common adverse event in transfusing packed red cells Urticaria is the most common adverse event following infusion of FFP Blood transfusion reactions Acute transfusion reactions present as adverse signs or symptoms during or within 24 hours of a blood transfusion. The most frequent reactions are fever, chills, pruritus, or urticaria, which typically resolve promptly without specific treatment or complications. Other signs occurring in temporal relationship with a blood transfusion, such as severe dyspnoea, pyrexia, or loss of consciousness may be the first indication of a more severe potentially fatal reaction. The causes of adverse reactions are multi-factorial. Immune mediated reactions, some of the most feared, occur as a result of component mismatch, the commonest cause of which is clerical error. More common, non immune mediated, complications may occur as a result of product contamination, this may be bacterial or viral. Transfusion related lung injury is well recognised and there are two proposed mechanisms which underpin this. One involves the sequestration of primed neutrophils within the recipient pulmonary capillary bed. The other proposed mechanism suggests that HLA mismatches between donor neutrophils and recipient lung tissue is to blame. The table below summarises the main types of transfusion reaction. Immune mediated Non immune mediated Pyrexia Hypocalcaemia Alloimmunization CCF Thrombocytopaenia Infections Transfusion associated lung injury Hyperkalaemia Graft vs Host disease Urticaria Acute or delayed haemolysis ABO incompatibility Rhesus incompatibility

Answer 1162

Beware of ureteric injury in colonic surgery. The inferior mesenteric vein drains into the splenic vein, this point of union lies close to the duodenum and this surgical maneouvre is a recognised cause of ileus. Left colon Position As the left colon passes inferiorly its posterior aspect becomes extraperitoneal, and the ureter and gonadal vessels are close posterior relations that may become involved in disease processes At a level of L3-4 (variable) the left colon becomes the sigmoid colon and wholly intraperitoneal once again The sigmoid colon is a highly mobile structure and may even lie on the right side of the abdomen It passes towards the midline, the taenia blend and this marks the transition between sigmoid colon and upper rectum Blood supply Inferior mesenteric artery However, the marginal artery (from the right colon) contributes, this contribution becomes clinically significant when the IMA is divided surgically (e.g. During AAA repair)

Answer 1163

Triad of symptoms: Respiratory Neurological Petechial rash (tends to occur after the first 2 symptoms) This man has a recent injury and physical signs that would be concordant with fat embolism syndrome. Meningococcal sepsis is not usually associated with hypoxia initially. Pulmonary emboli are not typically associated with pyrexia. Fat embolism Diagnosis and clinical features System Feature Respiratory Early persistent tachycardia Tachypnoea, dyspnoea, hypoxia usually 72 hours following injury Pyrexia Dermatological Red/ brown impalpable petechial rash (usually only in 25-50%) Subconjunctival and oral haemorrhage/ petechiae CNS Confusion and agitation Retinal haemorrhages and intra-arterial fat globules on fundoscopy Imaging May be normal Fat emboli tend to lodge distally and therefore CTPA may not show any vascular occlusion, a ground glass appearance may be seen at the periphery Treatment Prompt fixation of long bone fractures Some debate regarding benefit Vs. risk of medullary reaming in femoral shaft/ tibial fractures in terms of increasing risk (probably does not). DVT prophylaxis General supportive care

Answer 1164

This patient has had a left occipital infarct, as there is only a homonymous hemianopia. If this patient had a temporal or parietal lobe infarct, there would be associated hemiparesis and higher cortical dysfunction. This is important to differentiate, as the carotid endarterectomy is inappropriate in this patient as the lesion is in the posterior cerebral artery. Stroke: types Primary intracerebral haemorrhage (PICH, c. 10%) Presents with headache, vomiting, loss of consciousness Total anterior circulation infarcts (TACI, c. 15%) Involves middle and anterior cerebral arteries Hemiparesis/hemisensory loss Homonymous hemianopia Higher cognitive dysfunction e.g. Dysphasia Partial anterior circulation infarcts (PACI, c. 25%) Involves smaller arteries of anterior circulation e.g. upper or lower division of middle cerebral artery Higher cognitive dysfunction or two of the three TACI features Lacunar infarcts (LACI, c. 25%) Involves perforating arteries around the internal capsule, thalamus and basal ganglia Present with either isolated hemiparesis, hemisensory loss or hemiparesis with limb ataxia Posterior circulation infarcts (POCI, c. 25%) Vertebrobasilar arteries Presents with features of brainstem damage Ataxia, disorders of gaze and vision, cranial nerve lesions Lateral medullary syndrome (posterior inferior cerebellar artery) Wallenberg's syndrome Ipsilateral: ataxia, nystagmus, dysphagia, facial numbness, cranial nerve palsy Contralateral: limb sensory loss Weber's syndrome Ipsilateral III palsy Contralateral weakness -------------------------------------- Anterior cerebral artery Contralateral hemiparesis and sensory loss, lower extremity > upper Disconnection syndrome Middle cerebral artery Contralateral hemiparesis and sensory loss, upper extremity > lower Contralateral hemianopia Aphasia (Wernicke's) Gaze abnormalities Posterior cerebral artery Contralateral hemianopia with macular sparing Disconnection syndrome Lacunar Present with either isolated hemiparesis, hemisensory loss or hemiparesis with limb ataxia Lateral medulla (posterior inferior cerebellar artery) Ipsilateral: ataxia, nystagmus, dysphagia, facial numbness, cranial nerve palsy e.g. Horner's Contralateral: limb sensory loss Pontine VI nerve: horizontal gaze palsy VII nerve Contralateral hemiparesis

Answer 1165

The histological features are as described with a classic biphasic (mixed stromal and epithelial elements), although benign local recurrence can complicate incomplete excision. As this is a benign lesion direct extension into the facial nerve is unlikely to occur. Facial nerve injury can happen during repeat parotid surgery. Neck lumps The table below gives characteristic exam question features for conditions causing neck lumps: Reactive lymphadenopathy By far the most common cause of neck swellings. There may be a history of local infection or a generalised viral illness Lymphoma Rubbery, painless lymphadenopathy The phenomenon of pain whilst drinking alcohol is very uncommon There may be associated night sweats and splenomegaly Thyroid swelling May be hypo-, eu- or hyperthyroid symptomatically Moves upwards on swallowing Thyroglossal cyst More common in patients < 20 years old Usually midline, between the isthmus of the thyroid and the hyoid bone Moves upwards with protrusion of the tongue May be painful if infected Pharyngeal pouch More common in older men Represents a posteromedial herniation between thyropharyngeus and cricopharyngeus muscles Usually not seen, but if large then a midline lump in the neck that gurgles on palpation Typical symptoms are dysphagia, regurgitation, aspiration and chronic cough Cystic hygroma A congenital lymphatic lesion (lymphangioma) typically found in the neck, classically on the left side Most are evident at birth, around 90% present before 2 years of age Branchial cyst An oval, mobile cystic mass that develops between the sternocleidomastoid muscle and the pharynx Develop due to failure of obliteration of the second branchial cleft in embryonic development Usually present in early adulthood Cervical rib More common in adult females Around 10% develop thoracic outlet syndrome Carotid aneurysm Pulsatile lateral neck mass which doesn't move on swallowing

Answer 1166

The patient has large volume blood loss and is unstable in spite of volume replacement. A laparoscopy is unlikely to demonstrate clear operative views to allow assessment. At laparotomy, there will need to be evacuation of blood (the use of a cell saver can be considered). Damage control principles should be followed in such cases. Massive haemorrhage Definition This is the loss of one blood volume in a 24 hour period or the loss of 50% of the circulating blood volume in 3 hours. A blood loss of 150ml/ minute is also included. The normal adult blood volume is 7% of total adult body weight. The blood volume equates to between 8 and 9% of a child's body weight. Complications of massive transfusion Complication Key points Hypothermia Blood is refrigerated Hypothermic blood impairs homeostasis Shifts Bohr curve to the left Hypocalcaemia Both FFP and platelets contain citrate anticoagulant, this may chelate calcium Hyperkalaemia Plasma of red cells stored for 4-5 weeks contains 5-10 mmol K+ Delayed type transfusion reactions Due to minor incompatibility issues especially if urgent or non cross matched blood used Transfusion related lung injury Acute onset non cardiogenic pulmonary oedema Leading cause of transfusion related deaths Greatest risk posed with plasma components Occurs as a result of leucocyte antibodies in transfused plasma Aggregation and degranulation of leucocytes in lung tissue accounts for lung injury Coagulopathy Anticipate once circulating blood volume transfused 1 blood volume usually drops platelet count to 100 or less 1 blood volume will both dilute and not replace clotting factors Fibrinogen concentration halves per 0.75 blood volume transfused References Stanworth S et al. Haematological management of major haemorrhage: a British Society for Haematology Guideline British Journal of Haematology 2022 (198): 654 to 667.

Answer 1167

The carotid sheath is crossed anteriorly by the hypoglossal nerves and the ansa cervicalis. The vagus lies within it. The cervical sympathetic chain lies posteriorly between the sheath and the prevertebral fascia. Common carotid artery The right common carotid artery arises at the bifurcation of the brachiocephalic trunk, the left common carotid arises from the arch of the aorta. Both terminate at the level of the upper border of the thyroid cartilage (the lower border of the third cervical vertebra) by dividing into the internal and external carotid arteries. Left common carotid artery This vessel arises immediately to the left and slightly behind the origin of the brachiocephalic trunk. Its thoracic portion is 2.5- 3.5 cm in length and runs superolaterally to the sternoclavicular joint. In the thorax The vessel is in contact, from below upwards, with the trachea, left recurrent laryngeal nerve, left margin of the oesophagus. Anteriorly the left brachiocephalic vein runs across the artery, and the cardiac branches from the left vagus descend in front of it. These structures together with the thymus and the anterior margins of the left lung and pleura separate the artery from the manubrium. In the neck The artery runs superiorly deep to sternocleidomastoid and then enters the anterior triangle. At this point it lies within the carotid sheath with the vagus nerve and the internal jugular vein. Posteriorly the sympathetic trunk lies between the vessel and the prevertebral fascia. At the level of C7 the vertebral artery and thoracic duct lie behind it. The anterior tubercle of C6 transverse process is prominent and the artery can be compressed against this structure (it corresponds to the level of the cricoid). Anteriorly at C6 the omohyoid muscle passes superficial to the artery. Within the carotid sheath the jugular vein lies lateral to the artery. Right common carotid artery The right common carotid arises from the brachiocephalic artery. The right common carotid artery corresponds with the cervical portion of the left common carotid, except that there is no thoracic duct on the right. The oesophagus is less closely related to the right carotid than the left. Summary points about the carotid anatomy Path Passes behind the sternoclavicular joint (12% patients above this level) to the upper border of the thyroid cartilage, to divide into the external (ECA) and internal carotid arteries (ICA). Relations Level of 6th cervical vertebra crossed by omohyoid Then passes deep to the thyrohyoid, sternohyoid, sternomastoid muscles. Passes anterior to the carotid tubercle (transverse process 6th cervical vertebra)-NB compression here stops haemorrhage. The inferior thyroid artery passes posterior to the common carotid artery. Then : Left common carotid artery crosses the thoracic duct, Right common carotid artery crossed by recurrent laryngeal nerve

Answer 1168

The key point in the history is the preceding flu like illness and absence of abdominal signs. These make mesenteric adenitis the most likely diagnosis. The patient should have a period of active observation, if this were to represent early appendicitis, then the clinical picture may change and this would be detected with serial examination. Right iliac fossa pain Differential diagnosis Appendicitis Pain radiating to right iliac fossa Anorexia (very common) Short history Diarrhoea and profuse vomiting rare Crohn's disease Often long history Signs of malnutrition Change in bowel habit, especially diarrhoea Mesenteric adenitis Mainly affects children Causes include Adenoviruses, Epstein Barr Virus, beta-haemolytic Streptococcus, Staphylococcus spp., Escherichia coli, Streptococcus viridans and Yersinia spp. Patients have a higher temperature than those with appendicitis If laparotomy is performed, enlarged mesenteric lymph nodes will be present Diverticulitis Both left and right sided disease may present with right iliac fossa pain Clinical history may be similar, although some change in bowel habit is usual When suspected, a CT scan may help in refining the diagnosis Meckel's diverticulitis A Meckel's diverticulum is a congenital abnormality that is present in about 2% of the population Typically 2 feet proximal to the ileocaecal valve May be lined by ectopic gastric mucosal tissue and produce bleeding Perforated peptic ulcer This usually produces upper quadrant pain but pain may be lower Perforations typically have a sharp sudden onset of pain in the history Incarcerated right inguinal or femoral hernia Usually only right iliac fossa pain if right sided or bowel obstruction. Bowel perforation secondary to caecal or colon carcinoma Seldom localised to right iliac fossa, although complete large bowel obstruction with caecal distension may cause pain prior to perforation. Gynaecological causes Pelvic inflammatory disease/salpingitis/pelvic abscess/Ectopic pregnancy/Ovarian torsion/Threatened or complete abortion/Mittelschmerz Urological causes Ureteric colic/UTI/Testicular torsion Other causes TB/Typhoid/Herpes Zoster/AAA/Situs inversus

Answer 1169

In the UK, the guidance has now changed and patients like this are managed expectantly with suggestion that they participate in bowel cancer screening programmes. Colonic polyps Colonic Polyps May occur in isolation, or greater numbers as part of the polyposis syndromes. In FAP greater than 100 polyps are typically present. The risk of malignancy in association with adenomas is related to size, and is the order of 10% in a 1cm adenoma. Isolated adenomas seldom give risk of symptoms (unless large and distal). Distally sited villous lesions may produce mucous and if very large, electrolyte disturbances may occur. Follow up of colonic polyps Group Action Colorectal cancer Colonoscopy 1 year post resection Large non pedunculated colorectal polyps (LNPCP), R0 resection One off scope at 3 years Large non pedunculated colorectal polyps (LNPCP) R1 or non en bloc resection Site check at 2-6 months and then a further scope at 12 months High risk findings at baseline colonoscopy One off surveillance at 3 years No high risk findings at baseline colonoscopy No colonoscopic surveillance and invite participation in NHSBCSP programme when due High risk findings More than 2 premalignant polyps including 1 or more advanced colorectal polyps OR More than 5 pre malignant polyps Exceptions to guidelines If patient more than 10 years younger than lower screening age and has polyps but no high risk findings, consider colonoscopy at 5 or 10 years. Segmental resection or complete colectomy should be considered when: 1. Incomplete excision of malignant polyp 2. Malignant sessile polyp 3. Malignant pedunculated polyp with submucosal invasion 4. Polyps with poorly differentiated carcinoma 5. Familial polyposis coli -Screening from teenager up to 40 years by 2 yearly sigmoidoscopy/colonoscopy -Panproctocolectomy and Ileostomy or Restorative Panproctocolectomy. Rectal polypoidal lesions may be amenable to trans anal endoscopic microsurgery. References Rutter MD et al. British Society of Gastroenterology/Association of Coloproctology of Great Britain and Ireland/Public Health England post- polypectomy and post- colorectal cancer resection surveillance guidelines. Gut 2019;0:123.

Answer 1170

The most likely diagnosis is pelvic inflammatory disease. Right upper quadrant pain occurs as part of the Fitz Hugh Curtis syndrome in which peri hepatic inflammation occurs. Gynaecological causes of abdominal pain A number of women will present with abdominal pain and subsequently be diagnosed with a gynaecological disorder. In addition to routine diagnostic work up of abdominal pain, all female patients should also undergo a bimanual vaginal examination, urine pregnancy test and consideration given to abdominal and pelvic ultrasound scanning. When diagnostic doubt persists a laparoscopy provides a reliable method of assessing suspected tubulo-ovarian pathology. Differential diagnoses of abdominal pain in females Diagnosis Features Investigation Treatment Mittelschmerz Usually mid cycle pain. Often sharp onset. Little systemic disturbance. May have recurrent episodes. Usually settles over 24-48 hours. Full blood count- usually normal Ultrasound- may show small quantity of free fluid Conservative Endometriosis 25% asymptomatic, in a further 25% associated with other pelvic organ pathology. Remaining 50% may have menstrual irregularity, infertility, pain and deep dyspareunia. Complex disease may result in pelvic adhesional formation with episodes of intermittent small bowel obstruction. Intra-abdominal bleeding may produce localised peritoneal inflammation. Recurrent episodes are common. Ultrasound- may show free fluid Laparoscopy will usually show lesions Usually managed medically, complex disease will often require surgery and some patients will even require formal colonic and rectal resections if these areas are involved Ovarian torsion Usually sudden onset of deep seated colicky abdominal pain. Associated with vomiting and distress. Vaginal examination may reveal adnexial tenderness. Ultrasound may show free fluid Laparoscopy is usually both diagnostic and therapeutic Laparoscopy Ectopic gestation Symptoms of pregnancy without evidence of intra uterine gestation. Present as an emergency with evidence of rupture or impending rupture. Open tubular ruptures may have sudden onset of abdominal pain and circulatory collapse, in other the symptoms may be more prolonged and less marked. Small amount of vaginal discharge is common. There is usually adnexial tenderness. Ultrasound showing no intra uterine pregnancy and beta HCG that is elevated May show intra abdominal free fluid Laparoscopy or laparotomy is haemodynamically unstable. A salphingectomy is usually performed. Pelvic inflammatory disease Bilateral lower abdominal pain associated with vaginal discharge. Dysuria may also be present. Peri-hepatic inflammation secondary to Chlamydia (Fitz Hugh Curtis Syndrome) may produce right upper quadrant discomfort. Fever >38o Full blood count- Leucocytosis Pregnancy test negative (Although infection and pregnancy may co-exist) Amylase - usually normal or slightly raised High vaginal and urethral swabs Usually medical management

Answer 1171

In Ghana, Schistosomiasis is more common than in the UK and may cause recurrent episodes of haematuria. In those affected with the condition who develop a bladder neoplasm, an SCC is the most common type. Bladder cancer Bladder cancer is the second most common urological cancer. It most commonly affects males aged between 50 and 80 years of age. Those who are current, or previous (within 20 years), smokers have a 2-5 fold increased risk of the disease. Exposure to hydrocarbons such as 2-Naphthylamine increases the risk. Although rare in the UK, chronic bladder inflammation arising from Schistosomiasis infection remains a common cause of squamous cell carcinomas, in those countries where the disease is endemic. Benign tumours Benign tumours of the bladder including inverted urothelial papilloma and nephrogenic adenoma are uncommon. Bladder malignancies Transitional cell carcinoma (>90% of cases) Squamous cell carcinoma ( 1-7% -except in regions affected by schistosomiasis) Adenocarcinoma (2%) Transitional cell carcinomas may arise as solitary lesions, or may be multifocal, owing to the effect of 'field change' within the urothelium. Up to 70% of TCC's will have a papillary growth pattern. These tumours are usually superficial in location and accordingly have a better prognosis. The remaining tumours show either mixed papillary and solid growth or pure solid growths. These tumours are typically more prone to local invasion and may be of higher grade, the prognosis is therefore worse. Those with T3 disease or worse have a 30% (or higher) risk of regional or distant lymph node metastasis. TNM Staging Stage Description T0 No evidence of tumour Ta Non invasive papillary carcinoma T1 Tumour invades sub epithelial connective tissue T2a Tumor invades superficial muscularis propria (inner half) T2b Tumor invades deep muscularis propria (outer half) T3 Tumour extends to perivesical fat T4 Tumor invades any of the following: prostatic stroma, seminal vesicles, uterus, vagina T4a Invasion of uterus, prostate or bowel T4b Invasion of pelvic sidewall or abdominal wall N0 No nodal disease N1 Single regional lymph node metastasis in the true pelvis (hypogastric, obturator, external iliac, or presacral lymph node) N2 Multiple regional lymph node metastasis in the true pelvis (hypogastric, obturator, external iliac, or presacral lymph node metastasis) N3 Lymph node metastasis to the common iliac lymph nodes M0 No distant metastasis M1 Distant disease Presentation Most patients (85%) will present with painless, macroscopic haematuria. In those patients with incidental microscopic haematuria, up to 10% of females aged over 50 will be found to have a malignancy (once infection excluded). Staging Most will undergo a cystoscopy and biopsies or TURBT, this provides histological diagnosis and information relating to depth of invasion. Locoregional spread is best determined using pelvic MRI and distant disease CT scanning. Nodes of uncertain significance may be investigated using PET CT. Treatment Those with superficial lesions may be managed using TURBT in isolation. Those with recurrences or higher grade/ risk on histology may be offered intravesical chemotherapy. Those with T2 disease are usually offered either surgery (radical cystectomy and ileal conduit) or radical radiotherapy. Prognosis T1 90% T2 60% T3 35% T4a 10-25% Any T, N1-N2 30%

Answer 1172

This will require a total gastrectomy. Retention of a gastric remnant is unlikely to achieve acceptable resection margins. Resection of the proximal stomach with pull up of the stomach is not standard oncological practice for gastric cancer. Gastric cancer Overview There are 700,000 new cases of gastric cancer worldwide each year. It is most common in Japan and less common in western countries. It is more common in men and incidence rises with increasing age. The exact cause of many sporadic cancer is not known, however, familial cases do occur in HNPCC families. In addition, smoking and smoked or preserved foods increase the risk. Japanese migrants retain their increased risk (decreased in subsequent generations). The distribution of the disease in western countries is changing towards a more proximal location (perhaps due to rising obesity). Pathology There is some evidence of support a stepwise progression of the disease through intestinal metaplasia progressing to atrophic gastritis and subsequent dysplasia, through to cancer. The favoured staging system is TNM. The risk of lymph node involvement is related to size and depth of invasion; early cancers confined to submucosa have a 20% incidence of lymph node metastasis. Tumours of the gastro-oesophageal junction are classified as below: Type 1 True oesophageal cancers and may be associated with Barrett's oesophagus. Type 2 Carcinoma of the cardia, arising from cardiac type epithelium or short segments with intestinal metaplasia at the oesophagogastric junction. Type 3 Sub cardial cancers that spread across the junction. Involve similar nodal stations to gastric cancer. Groups for close endoscopic monitoring Intestinal metaplasia of columnar type Atrophic gastritis Low to medium grade dysplasia Patients who have previously undergone resections for benign peptic ulcer disease (except highly selective vagotomy). Referral to endoscopy Patients of any age with dyspepsia and any of the following Patients without dyspepsia Worsening dyspepsia Chronic gastrointestinal bleeding Dysphagia Barretts oesophagus Dysphagia Unexplained abdominal pain or weight loss Intestinal metaplasia Weight loss Vomiting Dysplasia Iron deficiency anaemia Upper abdominal mass Atrophic gastritis Upper abdominal mass Jaundice Patient aged over 55 years with unexplained or persistent dyspepsia Staging CT scanning of the chest abdomen and pelvis is the routine first line staging investigation in most centres. Laparoscopy to identify occult peritoneal disease PET CT (particularly for junctional tumours) Treatment Proximally sited disease greater than 5-10cm from the OG junction may be treated by sub total gastrectomy Total gastrectomy if tumour is <5cm from OG junction For type 2 junctional tumours (extending into oesophagus) oesophagogastrectomy is usual Endoscopic sub mucosal resection may play a role in early gastric cancer confined to the mucosa and perhaps the sub mucosa (this is debated) Lymphadenectomy should be performed. A D2 lymphadenectomy is widely advocated by the Japanese, the survival advantages of extended lymphadenectomy have been debated. However, the overall recommendation is that a D2 nodal dissection be undertaken. Most patients will receive chemotherapy either pre or post operatively. Prognosis UK Data Disease extent Percentage 5 year survival All RO resections 54% Early gastric cancer 91% Stage 1 87% Stage 2 65% Stage 3 18% Operative procedure Total Gastrectomy , lymphadenectomy and Roux en Y anastomosis General anaesthesia Prophylactic intravenous antibiotics Incision: Rooftop. Perform a thorough laparotomy to identify any occult disease. Mobilise the left lobe of the liver off the diaphragm and place a large pack over it. Insert a large self retaining retractor e.g. omnitract or Balfour (take time with this, the set up should be perfect). Pack the small bowel away. Begin by mobilising the omentum off the transverse colon. Proceed to detach the short gastric vessels. Mobilise the pylorus and divide it at least 2cm distally using a linear cutter stapling device. Continue the dissection into the lesser sac taking the lesser omentum and left gastric artery flush at its origin. The lymph nodes should be removed en bloc with the specimen where possible. Place 2 stay sutures either side of the distal oesophagus. Ask the anaesthetist to pull back on the nasogastric tube. Divide the distal oesophagus and remove the stomach. The oesphago jejunal anastomosis should be constructed. Identify the DJ flexure and bring a loop of jejunum up to the oesophagus (to check it will reach). Divide the jejunum at this point. Bring the divided jejunum either retrocolic or antecolic to the oesophagus. Anastamose the oesophagus to the jejunum, using either interrupted 3/0 vicryl or a stapling device. Then create the remainder of the Roux en Y reconstruction distally. Place a jejunostomy feeding tube. Wash out the abdomen and insert drains (usually the anastomosis and duodenal stump). Help the anaesthetist insert the nasogastric tube (carefully!) Close the abdomen and skin. Enteral feeding may commence on the first post-operative day. However, most surgeons will leave patients on free NG drainage for several days and keep them nil by mouth.

Answer 1173

The urinary bladder has a rich venous plexus surrounding it, this drains subsequently into the internal iliac vein. The vesicoprostatic plexus may be a site of considerable venous bleeding during cystectomy. Bladder The empty bladder is contained within the pelvic cavity. It is usually a three sided pyramid. The apex of the bladder points forwards towards the symphysis pubis and the base lies immediately anterior to the rectum or vagina. Continuous with the apex is the median umbilical ligament, during development this was the site of the urachus. The inferior aspect of the bladder is retroperitoneal and the superior aspect covered by peritoneum. As the bladder distends it will tend to separate the peritoneum from the fascia of transversalis. For this reason a bladder that is distended due to acute urinary retention may be approached with a suprapubic catheter that avoids entry into the peritoneal cavity. The trigone is the least mobile part of the bladder and forms the site of the ureteric orifices and internal urethral orifice. In the empty bladder the ureteric orifices are approximately 2-3cm apart, this distance may increase to 5cm in the distended bladder. Arterial supply The superior and inferior vesical arteries provide the main blood supply to the bladder. These are branches of the internal iliac artery. Venous drainage In males the bladder is drained by the vesicoprostatic venous plexus. In females the bladder is drained by the vesicouterine venous plexus. In both sexes this venous plexus will ultimately drain to the internal iliac veins. Lymphatic drainage Lymphatic drainage is predominantly to the external iliac nodes, internal iliac and obturator nodes also form sites of bladder lymphatic drainage. Innervation Parasympathetic nerve fibres innervate the bladder from the pelvic splanchnic nerves. Sympathetic nerve fibres are derived from L1 and L2 via the hypogastric nerve plexuses. The parasympathetic nerve fibres will typically cause detrusor muscle contraction and result in voiding. The muscle of the trigone is innervated by the sympathetic nervous system. The external urethral sphincter is under conscious control. During bladder filling the rate of firing of nerve impulses to the detrusor muscle is low and receptive relaxation occurs. At higher volumes and increased intra vesical pressures the rate of neuronal firing will increase and eventually voiding will occur.

Answer 1174

Isolated hemisensory loss is a feature of a lacunar infarct. Stroke: types Primary intracerebral haemorrhage (PICH, c. 10%) Presents with headache, vomiting, loss of consciousness Total anterior circulation infarcts (TACI, c. 15%) Involves middle and anterior cerebral arteries Hemiparesis/hemisensory loss Homonymous hemianopia Higher cognitive dysfunction e.g. Dysphasia Partial anterior circulation infarcts (PACI, c. 25%) Involves smaller arteries of anterior circulation e.g. upper or lower division of middle cerebral artery Higher cognitive dysfunction or two of the three TACI features Lacunar infarcts (LACI, c. 25%) Involves perforating arteries around the internal capsule, thalamus and basal ganglia Present with either isolated hemiparesis, hemisensory loss or hemiparesis with limb ataxia Posterior circulation infarcts (POCI, c. 25%) Vertebrobasilar arteries Presents with features of brainstem damage Ataxia, disorders of gaze and vision, cranial nerve lesions Lateral medullary syndrome (posterior inferior cerebellar artery) Wallenberg's syndrome Ipsilateral: ataxia, nystagmus, dysphagia, facial numbness, cranial nerve palsy Contralateral: limb sensory loss Weber's syndrome Ipsilateral III palsy Contralateral weakness -------------------------------------- Anterior cerebral artery Contralateral hemiparesis and sensory loss, lower extremity > upper Disconnection syndrome Middle cerebral artery Contralateral hemiparesis and sensory loss, upper extremity > lower Contralateral hemianopia Aphasia (Wernicke's) Gaze abnormalities Posterior cerebral artery Contralateral hemianopia with macular sparing Disconnection syndrome Lacunar Present with either isolated hemiparesis, hemisensory loss or hemiparesis with limb ataxia Lateral medulla (posterior inferior cerebellar artery) Ipsilateral: ataxia, nystagmus, dysphagia, facial numbness, cranial nerve palsy e.g. Horner's Contralateral: limb sensory loss Pontine VI nerve: horizontal gaze palsy VII nerve Contralateral hemiparesis

Answer 1175

Most commonly found in the duodenum (in up to 50% patients), then the pancreas (approximately 20%). Other ectopic areas include stomach, spleen, gallbladder and ovary Greater than 4/5 of gastrinomas are found within the triangle bounded by: Cystic and common bile duct (Top) 2nd and 3rd part of the duodenum (Bottom) Neck and body of pancreas (Medial) Pancreatic gastrinomas are normally solitary and display malignant behaviour. Zollinger Ellison syndrome is composed of the triad of: 1. Non beta islet cell tumours of the pancreas 2. Hypergastrinaemia 3. Severe ulcer disease Clinical features related to peptic ulcer disease. Diagnosis is based on 3 criteria: 1. Fasting hypergastrinaemia 2. Increased basal acid output 3. Secretin stimulation test positive Management Resection if localised disease Pancreatic cancer - Adenocarcinoma Risk factors: Smoking, diabetes, adenoma, familial adenomatous polyposis Mainly occur in the head of the pancreas (70%) Spread locally and metastasizes to the liver Carcinoma of the pancreas should be differentiated from other periampullary tumours with better prognosis Clinical features Weight loss Painless jaundice Epigastric discomfort (pain usually due to invasion of the coeliac plexus is a late feature) Pancreatitis Trousseau's sign: migratory superficial thrombophlebitis Investigations USS: May miss small lesions CT Scanning (pancreatic protocol). If unresectable on CT then no further staging needed PET/CT for those with operable disease on CT alone ERCP/ MRI for bile duct assessment Staging laparoscopy to exclude peritoneal disease Management Head of pancreas: Whipple's resection (SE dumping and ulcers). Newer techniques include pylorus preservation and SMA/ SMV resection Carcinoma body and tail: poor prognosis, distal pancreatectomy, if operable Usually adjuvent chemotherapy for resectable disease ERCP and stent for jaundice and palliation Surgical bypass may be needed for duodenal obstruction

Answer 1176

Sub dural haematomas are the commonest intracranial mass lesions resulting from trauma. They are classified as acute, sub acute or chronic according to tempo of onset. Acute sub dural haematomas will present within 72 hours of the original injury and have hyperdense, crescent shaped appearances on CT scanning. Head injury Patients who suffer head injuries should be managed according to ATLS principles and extra cranial injuries should be managed alongside cranial trauma. Inadequate cardiac output will compromise CNS perfusion irrespective of the nature of the cranial injury. Types of traumatic brain injury Extradural haematoma Bleeding into the space between the dura mater and the skull. Often results from acceleration-deceleration trauma or a blow to the side of the head. The majority of extradural haematomas occur in the temporal region where skull fractures cause a rupture of the middle meningeal artery. Features Raised intracranial pressure Some patients may exhibit a lucid interval Subdural haematoma Bleeding into the outermost meningeal layer. Most commonly occur around the frontal and parietal lobes. May be either acute or chronic. Risk factors include old age and alcoholism. Slower onset of symptoms than a extradural haematoma. Subarachnoid haemorrhage Usually occurs spontaneously in the context of a ruptured cerebral aneurysm, but may be seen in association with other injuries when a patient has sustained a traumatic brain injury. Pathophysiology Primary brain injury may be focal (contusion/ haematoma) or diffuse (diffuse axonal injury) Diffuse axonal injury occurs as a result of mechanical shearing following deceleration, causing disruption and tearing of axons Intra-cranial haematomas can be extradural, subdural or intracerebral, while contusions may occur adjacent to (coup) or contralateral (contre-coup) to the side of impact Secondary brain injury occurs when cerebral oedema, ischaemia, infection, tonsillar or tentorial herniation exacerbates the original injury. The normal cerebral auto regulatory processes are disrupted following trauma rendering the brain more susceptible to blood flow changes and hypoxia The Cushings reflex (hypertension and bradycardia) often occurs late and is usually a pre terminal event Management Where there is life threatening rising ICP such as in extra dural haematoma and whilst theatre is prepared or transfer arranged use of IV mannitol/ frusemide may be required. Diffuse cerebral oedema may require decompressive craniotomy Exploratory Burr Holes have little management in modern practice except where scanning may be unavailable and to thus facilitate creation of formal craniotomy flap Depressed skull fractures that are open require formal surgical reduction and debridement, closed injuries may be managed non operatively if there is minimal displacement. ICP monitoring is appropriate in those who have GCS 3-8 and normal CT scan. ICP monitoring is mandatory in those who have GCS 3-8 and abnormal CT scan. Hyponatraemia is most likely to be due to syndrome of inappropriate ADH secretion. Minimum of cerebral perfusion pressure of 70mmHg in adults. Minimum cerebral perfusion pressure of between 40 and 70 mmHg in children. Interpretation of pupillary findings in head injuries Pupil size Light response Interpretation Unilaterally dilated Sluggish or fixed 3rd nerve compression secondary to tentorial herniation Bilaterally dilated Sluggish or fixed Poor CNS perfusion Bilateral 3rd nerve palsy Unilaterally dilated or equal Cross reactive (Marcus - Gunn) Optic nerve injury Bilaterally constricted May be difficult to assess Opiates Pontine lesions Metabolic encephalopathy Unilaterally constricted Preserved Sympathetic pathway disruption

Answer 1177

Osler nodes are normally described as tender, purple/red raised lesions with a pale centre. These lesions occur as a result of immune complex deposition. These occur most often in association with endocarditis. However, other causes include SLE, gonorrhoea, typhoid and haemolytic anaemia. Hand diseases Dupuytrens contracture Fixed flexion contracture of the hand where the fingers bend towards the palm and cannot be fully extended. Caused by underlying contractures of the palmar aponeurosis . The ring finger and little finger are the fingers most commonly affected. The middle finger may be affected in advanced cases, but the index finger and the thumb are nearly always spared. Progresses slowly and is usually painless. In patients with this condition, the tissues under the skin on the palm of the hand thicken and shorten so that the tendons connected to the fingers cannot move freely. The palmar aponeurosis becomes hyperplastic and undergoes contracture. Commonest in males over 40 years of age. Association with liver cirrhosis and alcoholism. However, many cases are idiopathic. Treatment is surgical and involves fasciectomy. However, the condition may recur and many surgical therapies are associated with risk of neurovascular damage to the digital nerves and arteries. Carpal tunnel syndrome Idiopathic median neuropathy at the carpal tunnel. Characterised by altered sensation of the lateral 3 fingers. The condition is commoner in females and is associated with other connective tissue disorders such as rheumatoid disease. It may also occur following trauma to the distal radius. Symptoms occur mainly at night in early stages of the condition. Examination may demonstrate wasting of the muscles of the thenar eminence and symptoms may be reproduced by Tinels test (compression of the contents of the carpal tunnel). Formal diagnosis is usually made by electrophysiological studies. Treatment is by surgical decompression of the carpal tunnel, a procedure achieved by division of the flexor retinaculum. Non - surgical options include splinting and bracing. Miscellaneous hand lumps Osler's nodes Osler's nodes are painful, red, raised lesions found on the hands and feet. They are the result of the deposition of immune complexes. Bouchard's nodes Hard, bony outgrowths or gelatinous cysts on the proximal interphalangeal joints (the middle joints of fingers or toes.) They are a sign of osteoarthritis, and are caused by formation of calcific spurs of the articular cartilage. Heberden's nodes Typically develop in middle age, beginning either with a chronic swelling of the affected joints or the sudden painful onset of redness, numbness, and loss of manual dexterity. This initial inflammation and pain eventually subsides, and the patient is left with a permanent bony outgrowth that often skews the fingertip sideways. It typically affects the DIP joint. Ganglion Swelling in association with a tendon sheath commonly near a joint. They are common lesions in the wrist and hand. Usually they are asymptomatic and cause little in the way of functional compromise. They are fluid filled although the fluid is similar to synovial fluid it is slightly more viscous. When the cysts are troublesome they may be excised.

Answer 1178

Ewing's sarcoma is a malignant round cell tumour occurring in the diaphysis of the long bones in the children. These are not confined to the ends of long bones. X- Rays often show a large soft-tissue mass with concentric layers of new bone formation ( 'onion-peel' sign). The ESR may be elevated, thus suggesting an inflammatory or an infective cause such as osteomyelitis; although osteomyelitis usually affects the metaphyseal region in children. Treatment is with chemotherapy and surgical excision, an endoprosthesis may be used to conserve the limb. Sarcomas Malignant tumours of mesenchymal origin Types May be either bone or soft tissue in origin. Bone sarcoma include: Osteosarcoma Ewings sarcoma (although non bony sites recognised) Chondrosarcoma - originate from Chondrocytes Soft tissue sarcoma are a far more heterogeneous group and include: Liposarcoma-adipocytes Rhabdomyosarcoma-striated muscle Leiomyosarcoma-smooth muscle Synovial sarcomas- close to joints (cell of origin not known but not synovium) Malignant fibrous histiocytoma is now referred to as undifferentiated pleomorphic sarcoma. Careful histological assessment of lesions now allows more accurate categorisation of sarcoma subtypes than was previously possible. Features Certain features of a mass or swelling should raise suspicion for a sarcoma these include: Large >5cm soft tissue mass Deep tissue location or intra muscular location Rapid growth Painful lump Assessment Imaging of suspicious masses should utilise a combination of MRI, CT and USS. Blind biopsy should not be performed prior to imaging and where required should be done in such a way that the biopsy tract can be subsequently included in any resection. Ewings sarcoma Commoner in males Incidence of 0.3 / 1, 000, 000 Onset typically between 10 and 20 years of age Location by femoral diaphysis is commonest site Histologically it is a small round tumour Blood borne metastasis is common and chemotherapy is often combined with surgery Osteosarcoma Mesenchymal cells with osteoblastic differentiation 20% of all primary bone tumours Incidence of 5 per 1,000,000 Peak age 15-30, commoner in males Limb preserving surgery may be possible and many patients will receive chemotherapy Liposarcoma Malignancy of adipocytes Rare, approximately 2.5 per 1,000,000. They are the most common soft tissue sarcoma Typically located in deep locations such as retroperitoneum Affect older age group usually >40 years of age May be well differentiated and thus slow growing although may undergo de-differentiation and disease progression Many tumours will have a pseudocapsule that can misleadingly allow surgeons to feel that they can 'shell out' these lesions. In reality, tumour may invade at the edge of the pseudocapsule and result in local recurrence if this strategy is adopted Usually resistant to radiotherapy, although this is often used in a palliative setting Malignant Fibrous Histiocytoma Tumour with large number of histiocytes Also described as undifferentiated pleomorphic sarcoma NOS (i.e. Cell of origin is not known) Four major subtypes are recognised: storiform-pleomorphic (70% cases), myxoid (less aggressive), giant cell and inflammatory Treatment is usually with surgical resection and adjuvant radiotherapy as this reduces the likelihood of local recurrence

Answer 1179

Stipple cells are found in lead poisoning/haemoglobinopathies. Blood film in hyposplenism: Howell-Jolly bodies Pappenheimer bodies Poikilocytes (Target cells) Erythrocyte containing siderotic granules Heinz bodies Post splenectomy blood film changes The loss of splenic tissue results in the inability to readily remove immature or abnormal red blood cells from the circulation. The red cell count does not alter significantly. However, cytoplasmic inclusions may be seen e.g. Howell-Jolly bodies. In the first few days after splenectomy target cells, siderocytes and reticulocytes will appear in the circulation. Immediately following splenectomy a granulocytosis (mainly composed of neutrophils) is seen, this is replaced by a lymphocytosis and monocytosis over the following weeks. The platelet count is usually increased and this may be persistent, oral antiplatelet agents may be needed in some patients.

Answer 1180

A CT scan with IV contrast is needed, without contrast only the perforated viscus question can be answered. Management of Pancreatitis Management of Acute Pancreatitis in the UK Diagnosis Traditionally hyperamylasaemia has been utilised with amylase being elevated three times the normal range. However, amylase may give both false positive and negative results. Serum lipase is both more sensitive and specific than serum amylase. It also has a longer half life. Serum amylase levels do not correlate with disease severity. Differential causes of hyperamylasaemia Acute pancreatitis Pancreatic pseudocyst Mesenteric infarct Perforated viscus Acute cholecystitis Diabetic ketoacidosis Assessment of severity Glasgow, Ranson scoring systems and APACHE II Biochemical scoring e.g. using CRP Features that may predict a severe attack within 48 hours of admission to hospital Initial assessment Clinical impression of severity Body mass index >30 Pleural effusion APACHE score >8 24 hours after admission Clinical impression of severity APACHE II >8 Glasgow score of 3 or more Persisting multiple organ failure CRP>150 48 hours after admission Glasgow Score of >3 CRP >150 Persisting or progressive organ failure Table adapted from UK guidelines for management of acute pancreatitis. GUT 2005, 54 suppl III Management Nutrition There is reasonable evidence to suggest that the use of enteral nutrition does not worsen the outcome in pancreatitis Most trials to date were underpowered to demonstrate a conclusive benefit. The rationale behind feeding is that it helps to prevent bacterial translocation from the gut, thereby contributing to the development of infected pancreatic necrosis. Use of antibiotic therapy Many UK surgeons administer antibiotics to patients with acute pancreatitis. However, there is very little evidence to support this practice. A recent Cochrane review highlights the potential benefits of administering Imipenem to patients with established pancreatic necrosis in the hope of averting the progression to infection. There are concerns that the administration of antibiotics in mild attacks of pancreatitis will not affect outcome and may contribute to antibiotic resistance and increase the risks of antibiotic associated diarrhoea. Surgery Patients with acute pancreatitis due to gallstones should undergo early cholecystectomy. Patients with obstructed biliary system due to stones should undergo early ERCP. Patients with extensive necrosis where infection is suspected should usually undergo FNA for culture. Patients with infected necrosis should undergo either radiological drainage or surgical necrosectomy. The choice of procedure depends upon local expertise. References www.bsg.org.uk/pdfworddocs/pancreatic.pdf Antibiotic therapy for prophylaxis against infection of pancreatic necrosis in acute pancreatitis. Villatoro et al. Cochrane Library DOI: 10.1002/14651858.CD002941.pub3. 2010 version.

Answer 1181

This is a classic description of an oculogyric crisis, a form of extrapyramidal disorder. An oculogyric crisis is an acute dystonic reaction. This is precipitated by antipsychotics (haloperidol) and metoclopramide in susceptible individuals with a genetic predisposition to this. Treatment is with procyclidine IM. Oculogyric crisis An oculogyric crisis is a dystonic reaction to certain drugs or medical conditions Features Restlessness, agitation Involuntary upward deviation of the eyes Causes Phenothiazines Haloperidol Metoclopramide Postencephalitic Parkinson's disease Management Procyclidine

Answer 1182

Ulnar nerve injury at wrist Branches of the ulnar nerve in the wrist and hand At the wrist the ulnar nerve divides into superficial and deep branches. The superficial branch lies deep to the palmaris brevis. It divides into two; to produce digital nerves, which innervate the skin of the medial third of the palm and the palmar surface of one and a half fingers. The deep branch arises from the nerve on the flexor retinaculum lateral to the pisiform bone. It passes posteriorly between the abductor and short flexor of the little finger supplying them, and supplying and piercing the opponens digiti minimi near its origin from the flexor retinaculum, turns laterally over the distal surface of the Hook of the Hamate bone. It eventually passes between the two heads of adductor pollicis with the deep palmar arch and ends in the first dorsal interosseous muscle. In the palm the deep branch also innervates the lumbricals and interosseous muscles.

Answer 1183

For ureteric stones with a maximum diameter of less than 10mm the first-line treatment is extracorporeal shock wave lithotripsy (ESWL). If ESWL fails or if the stone is impacted in the upper ureter then ureteroscopy can be performed. Management of renal stones Urolithiasis will affect up to 15% of the worldwide population. The development of sudden onset loin to groin pain which is colicky in nature is a classic feature in the history. It is nearly always associated with haematuria that is either visible or non-visible but detectable on urine dipstick testing. Where the diagnosis is suspected the most sensitive and specific investigation is helical, non-contrast, computerised tomographic (CT) scanning. Management Most renal stones measuring less than 5mm in maximum diameter will typically pass within 4 weeks of symptom onset(1)(2). More urgent treatment is indicated in the presence of ureteric obstruction, renal developmental abnormalities such as horseshoe kidney and previous renal transplant. Ureteric obstruction together with infection is a surgical emergency and the system must be decompressed. Options include nephrostomy tube placement or ureteric stent placement via cystoscopy. In the non-emergency setting the preferred options for treatment of stone disease include extracorporeal shock wave lithotripsy (ESWL), percutaneous nephrolithotomy (PCNL) and ureteroscopy (URS). These minimally invasive options are the most popular first line treatments. Open surgery remains an option in a few selected cases. Extracorporeal shock wave lithotripsy A shock wave is generated external to the patient. Internally, cavitation bubbles and mechanical stress lead to stone fragmentation. The passage of shock waves can occasionally result in the development of solid organ injury. Fragmentation of larger stones may result in the development of ureteric obstruction. The procedure can be uncomfortable for patients and analgesia is often required during the procedure and afterwards. ESWL is contra-indicated in pregnant females and patients with significant vascular calcification. Ureteroscopy A ureteroscope is passed retrograde via the urethra and bladder, into the ureter and renal pelvis. Laser or pneumatic fragmentation (lithoclasty) is performed using the ureteroscope and stone fragments are extracted(3). In some cases a stent is left in situ after the procedure. Percutaneous nephrolithotomy In this procedure percutaneous access is gained to the renal collecting system. Once access is achieved, endoscopic intra-corporeal lithotripsy, lithoclasty or laser stone fragmentation is performed and stone fragments removed. Therapeutic selection Renal stones Size First line option Less than 5mm and asymptomatic Watchful waiting Less than 10mm ESWL 10 20mm ESWL or ureteroscopy Greater than 20mm (including staghorn calculi) PCNL Ureteric stones Size First line option Less than 5mm Watchful waiting 5-10mm ESWL (if upper ureter) 10-20mm Ureteroscopy Reference 1. Bultitude M, Rees J. Management of renal colic. BMJ. 2012;345(7872):18. 2. Shah TT, Gao C, Peters M, Manning T, Cashman S, Nambiar A, et al. Factors associated with spontaneous stone passage in a contemporary cohort of patients presenting with acute ureteric colic: results from the Multi-centre cohort study evaluating the role of Inflammatory Markers In patients presenting with acute ureteric . BJU Int. 2019 Apr. 3. BAUS. Ureteroscopy (Telescopic surgery for stone removal) (Internet). BAUS patient information leaflet. 2017 (cited 2019 Jun 27). p. 16. Available from: https://www.baus.org.uk/userfiles/pages/files/Patients/Leaflets/Ureteroscopy for stone.pdf 4. BAUS. Percutaneous nephrolithotomy (keyhole surgery for kidney stones). BAUS patient information leaflet. 2017. p. 16. Available from: https://www.baus.org.uk/userfiles/pages/files/Patients/Leaflets/PCNL.pdf 5. NICE. Renal and ureteric stones: assessment and management. NICE Guide[NG118]. 2019;(January):112.

Answer 1184

Bacteroides is commonly present in severe peritoneal infections and as it is facultatively anaerobic may be present in pus. It has a pungent aroma. Surgical Microbiology An extensive topic so an overview is given here. Organisms causing common surgical infections are reasonable topics in the examination. However, microbiology is less rigorously tested than anatomy, for example. Common organisms Staphylococcus aureus Facultative anaerobe Gram positive coccus Haemolysis on blood agar plates Catalase positive 20% population are long term carriers Exo and entero toxin may result in toxic shock syndrome and gastroenteritis respectively Ideally treated with penicillin although many strains now resistant through beta Lactamase production. In the UK less than 5% of isolates are sensitive to penicillin. Resistance to methicillin (and other antibiotics) is mediated by the mec operon , essentially penicillin binding protein is altered and resistance to this class of antibiotics ensues Common cause of cutaneous infections and abscesses Streptococcus pyogenes Gram positive, forms chain like colonies, Lancefield Group A Streptococcus Produces beta haemolysis on blood agar plates Rarely part of normal skin microflora Catalase negative Releases a number of proteins/ virulence factors into host including hyaluronidase, streptokinase which allow rapid tissue destruction Releases superantigens such as pyogenic exotoxin A which results in scarlet fever Remains sensitive to penicillin, macrolides may be used as an alternative. Escherichia coli Gram negative rod Facultative anaerobe, non sporing Wide range of subtypes and some are normal gut commensals Some subtypes such as 0157 may produce lethal toxins resulting in haemolytic-uraemic syndrome Enterotoxigenic E-Coli produces an enterotoxin (ST enterotoxin) that results in large volume fluid secretion into the gut lumen (Via cGMP activation) Enteropathogenic E-Coli binds to intestinal cells and cause structural damage, this coupled with a moderate (or in case of enteroinvasive E-Coli significant) invasive component produces enteritis and large volume diarrhoea together with fever. They are resistant to many antibiotics used to treat gram positive infections and acquire resistance rapidly and are recognised as producing beta lactamases Campylobacter jejuni Curved, gram negative, non sporulating bacteria One of the commonest causes of diarrhoea worldwide Produces enteritis which is often diffuse and blood may be passed Remains a differential for right iliac fossa pain with diarrhoea Self limiting infection so antibiotics are not usually advised. However, the quinolones are often rapidly effective. Helicobacter pylori Gram negative, helix shaped rod, microaerophillic Produces hydrogenase that can derive energy from hydrogen released by intestinal bacteria Flagellated and mobile Those carrying the cag A gene may cause ulcers It secretes urease that breaks down gastric urea> Carbon dioxide and ammonia> ammonium>bicarbonate (simplified!) The bicarbonate can neutralise the gastric acid. Usually colonises the gastric antrum and irritates resulting in increased gastrin release and higher levels of gastric acid. These patients will develop duodenal ulcers. In those with more diffuse H-Pylori infection gastric acid levels are lower and ulcers develop by local tissue damage from H-Pylori- these patients get gastric ulcers. Diagnosis may be made by serology (approx. 75% sensitive). Biopsy urease test during endoscopy probably the most sensitive. In patients who are colonised 10-20% risk of peptic ulcer, 1-2% risk gastric cancer, <1% risk MALT lymphoma.

Answer 1185

5 alpha reductase inhibitors have a more favorable side effect profile than α blockers. Alpha blockers have a faster onset of action (but lower reduction of complications from BPH) than 5 α reductase inhibitors. Benign Prostatic Hyperplasia Benign prostatic hyperplasia occurs via an increase in the epithelial and stromal cell numbers in the peri-urethral zone of the prostate. BPH is very common and 90% of men aged over 80 will have at least microscopic evidence of benign prostatic hyperplasia. The causes of BPH are still not well understood, but the importance of androgens remains appreciated even if the exact role by which they induce BPH is elusive. Presentation The vast majority of men will present with lower urinary tract symptoms. These will typically be: Poor flow Nocturia Hesitancy Incomplete and double voiding Terminal dribbling Urgency Incontinence Investigation Digital rectal examination to assess prostatic size and morphology. Urine dipstick for infections and haematuria. Uroflowmetry (a flow rate of >15ml/second helps to exclude BOO) Bladder pressure studies may help identify detrusor failure and whilst may not form part of first line investigations should be included in those with atypical symptoms and prior to redo surgery. Bladder scanning to demonstrate residual volumes. USS if high pressure chronic retention. Management Lifestyle changes such as stopping smoking and altering fluid intake may help those with mild symptoms. Medical therapy includes alpha blockers and 5 α reductase inhibitors. The former work quickly on receptor zones located at the bladder neck. Cardiovascular side effects are well documented. The latter work on testosterone metabolising enzymes. Although they have a slower onset of action, the 5 α reductase inhibitors may prevent acute urinary retention. Surgical therapy includes transurethral resection of the prostate and is the treatment of choice in those with severe symptoms and those who fail to respond to medical therapy. More tailored bladder neck incision procedures may be considered in those with small prostates. Retrograde ejaculation may occur following surgery. The change in the type of irrigation solutions used has helped to minimise the TURP syndrome of electrolyte disturbances.

Answer 1186

Aldosterone serves to conserve sodium and water. It is produced in the zona glomerulosa of the adrenal cortex. Aldosterone Aldosterone is secreted by the zona glomerulosa of the adrenal cortex. It is a mineralocorticoid hormone. Secretion is regulated by the renin- angiotensin system, and by plasma levels of sodium and potassium. Aldosterone conserves sodium by stimulating the reabsorption of sodium in the distal nephron in exchange for potassium. Lack of aldosterone release will result in hyperkalaemia and hyponatraemia.

Answer 1187

It is likely that the patient has developed lower leg compartment syndrome and as cell death occurs, hyperkalaemia results. The time taken for the laparotomy would have contributed to this event and provided a distraction. It is less likely that the patient will have developed intra abdominal compartment syndrome in this time frame. Compartment syndrome - This is a particular complication that may occur following fractures (or following ischaemia re-perfusion injury in vascular patients). It is characterised by raised pressure within a closed anatomical space. The raised pressure within the compartment will eventually compromise tissue perfusion resulting in necrosis. The two main fractures carrying this complication include supracondylar fractures and tibial shaft injuries. Symptoms and signs Pain, especially on movement (even passive) Parasthesiae Pallor may be present Arterial pulsation may still be felt as the necrosis occurs as a result of microvascular compromise Paralysis of the muscle group may occur Diagnosis Is made by measurement of intracompartmental pressure measurements. Pressures in excess of 20mmHg are abnormal and >40mmHg is diagnostic. Treatment This is essentially prompt and extensive fasciotomies In the lower limb the deep muscles may be inadequately decompressed by the inexperienced operator when smaller incisions are performed Myoglobinuria may occur following fasciotomy and result in renal failure and for this reason these patients require aggressive IV fluids Where muscle groups are frankly necrotic at fasciotomy they should be debrided and amputation may have to be considered Death of muscle groups may occur within 4-6 hours

Answer 1188

Most renal tumours are yellow or brown in colour. TCC's are one of the few tumours to appear pink. The finding of a TCC in the renal pelvis mandates a nephroureterectomy. Renal lesions Lesion Disease specific features Treatment Renal cell carcinoma Most present with haematuria (50%) Common renal tumour (85% cases) Paraneoplastic features include hypertension and polycythaemia Most commonly has haematogenous mestastasis Usually radical or partial nephrectomy Nephroblastoma Rare childhood tumour It accounts for 80% of all genitourinary malignancies in those under the age of 15 years Up to 90% will have a mass 50% will be hypertensive Diagnostic work up includes ultrasound and CT scanning Surgical resection combined with chemotherapy (usually vincristine, actinomycin D and doxorubicin) Neuroblastoma Most common extracranial tumour of childhood 80% occur in those under 4 years of age Tumour of neural crest origin (up to 50% occur in the adrenal gland) The tumour is usually calcified and may be diagnosed using MIBG scanning Staging is with CT Surgical resection, radiotherapy and chemotherapy Transitional cell carcinoma Accounts for 90% of lower urinary tract tumours, but only 10% of renal tumours Males affected 3x more than females Occupational exposure to industrial dyes and rubber chemicals may increase risk Up to 80% present with painless haematuria Diagnosis and staging is with CT IVU Radical nephroureterectomy Angiomyolipoma 80% of these hamartoma type lesions occur sporadically, the remainder are seen in those with tuberous sclerosis Tumour is composed of blood vessels, smooth muscle and fat Massive bleeding may occur in 10% of cases 50% of patients with lesions >4cm will have symptoms and will require surgical resection

Answer 1189

Pregnancy and frank haematuria, especially if there is a history of placenta previa or prior caesarean section, should indicate this diagnosis. There is invasive placental implantation into the myometrium, which can rarely extend into the bladder causing severe bleeding. Haematuria Causes of haematuria Trauma Injury to renal tract Renal trauma commonly due to blunt injury (others penetrating injuries) Ureter trauma rare: iatrogenic Bladder trauma: due to RTA or pelvic fractures Infection Remember TB Malignancy Renal cell carcinoma (remember paraneoplastic syndromes): painful or painless Urothelial malignancies: 90% are transitional cell carcinoma, can occur anywhere along the urinary tract. Painless haematuria. Squamous cell carcinoma and adenocarcinoma: rare bladder tumours Prostate cancer Penile cancers: SCC Renal disease Glomerulonephritis Stones Microscopic haematuria common Structural abnormalities Benign prostatic hyperplasia (BPH) causes haematuria due to hypervascularity of the prostate gland Cystic renal lesions e.g. polycystic kidney disease Vascular malformations Renal vein thrombosis due to renal cell carcinoma Coagulopathy Causes bleeding of underlying lesions Drugs Cause tubular necrosis or interstitial nephritis: aminoglycosides, chemotherapy Interstitial nephritis: penicillin, sulphonamides, and NSAIDs Anticoagulants Benign Exercise Gynaecological Endometriosis: flank pain, dysuria, and haematuria that is cyclical Iatrogenic Catheterisation Radiotherapy; cystitis, severe haemorrhage, bladder necrosis Pseudohaematuria For example following consumption of beetroot References Http://bestpractice.bmj.com/best-practice/monograph/316/overview/aetiology.html

Answer 1190

Glucocorticoids exert their effects by binding intracellular receptors that are then transported to the nucleus where they affect gene transcription. There are some questions in the MRCS now that seem to test common pharmacology and so we have decided to include this. A detailed knowledge of the mechanisms by which these effects occur is not needed. Corticosteroids Synthesised from cholesterol within the adrenal cortex Bind to specific intracellular glucocorticoid receptors located on the nucleus Effects of glucocorticoids Metabolic Decreased uptake and utilisation of glucose, increased gluconeogenesis and hyperglycaemia Increased protein catabolism Permissive effect on lipolytic hormones Regulatory actions Has a negative feedback action on the hypothalamus causing reduced release of endogenous glucocorticoids Within the CVS they cause decreased vasodilation and decreased fluid exudation They decrease osteoblastic activity and increase osteoclastic activity Decrease acute and chronic inflammation (decrease in influx and activity of leukocytes), decreased clonal expansion of B and T lymphocytes.

Answer 1191

There is good evidence to support the use of extended thromboprophylaxis after pelvic cancer surgery. Don't confuse low dose and high dose low molecular weight heparins, re read the options if you got the answer wrong. Thromboprophylaxis in surgical patients Deep vein thrombosis may develop insidiously in many surgical patients. Untreated it may progress to result in pulmonary embolism. The following surgical patients are at increased risk of deep vein thrombosis: Surgery greater than 90 minutes at any site or greater than 60 minutes if the procedure involves the lower limbs or pelvis Acute admissions with inflammatory process involving the abdominal cavity Expected significant reduction in mobility Age over 60 years Known malignancy Thrombophilia Previous thrombosis BMI >30 Taking hormone replacement therapy or the contraceptive pill Varicose veins with phlebitis Mechanical thromboprophylaxis Early ambulation after surgery is cheap and is effective Compression stockings (contra -indicated in peripheral arterial disease) Intermittent pneumatic compression devices Foot impulse devices Therapeutic agents Agent Mode of action Uses Low molecular weight heparin Binds antithrombin causing inhibition of factor Xa Thromboprophylaxis or treatment of thromboembolic events in those with normal renal function. It is given as once daily subcutaneous injection Unfractionated heparin Binds antithrombin III affecting thrombin and factor Xa Effective anticoagulation, administered intravenously it has a rapid onset and its therapeutic effects decline quickly on stopping and infusion. Its activity is measured using the APTT. If need be it can be reversed using protamine sulphate Dabigatran Orally administered direct thrombin inhibitor Used prophylaxis in hip and knee surgery. It does not require therapeutic monitoring. It should not be used in any patient in whom there is a risk of active bleeding or imminent likelihood of surgery. It is reversed using Idarucizumab

Answer 1192

Comedo necrosis is a feature of high nuclear grade ductal carcinoma in situ. It has a high risk of being associated with foci of invasion. Breast cancer - Commoner in the older age group Invasive ductal carcinomas are the most common type. Some may arise as a result of ductal carcinoma in situ (DCIS). There are associated carcinomas of special type e.g. Tubular that may carry better prognosis. The pathological assessment involves assessment of the tumour and lymph nodes, sentinel lymph node biopsy is often used to minimise the morbidity of an axillary dissection. Treatment, typically this is either wide local excision or mastectomy. There are many sub types of both of these that fall outside of the MRCS. Some key rules to bear in mind. Whatever operation is contemplated the final cosmetic outcome does have a bearing. A woman with small breasts and a large tumour will tend to fare better with mastectomy, even if clear pathological and clinical margins can be obtained. Conversely a women with larger breasts may be able to undergo breast conserving surgery even with a relatively large primary lesion (NB tumours >4cm used to attract recommendation for mastectomy). For screen detected and impalpable tumour image guidance will be necessary. Reconstruction is always an option following any resectional procedure. However, its exact type must be tailored to age and co-morbidities of the patient. The main operations in common use include latissimus dorsi myocutaneous flap and sub pectoral implants. Women wishing to avoid a prosthesis may be offered TRAM or DIEP flaps. Surgical options Mastectomy vs Wide local excision Mastectomy Wide Local Excision Multifocal tumour Solitary lesion Central tumour Peripheral tumour Large lesion in small breast Small lesion in large breast DCIS >4cm DCIS <4cm Patient Choice Patient choice Central lesions may be managed using breast conserving surgery where an acceptable cosmetic result may be obtained, this is rarely the case in small breasts Whatever surgical option is chosen the aim should be to have a local recurrence rate of 5% or less at 5 years [1]. Nottingham Prognostic Index The Nottingham Prognostic Index can be used to give an indication of survival. In this system the tumour size is weighted less heavily than other major prognostic parameters. Calculation of NPI Tumour Size x 0.2 + Lymph node score(From table below)+Grade score(From table below). Score Lymph nodes involved Grade 1 0 1 2 1-3 2 3 >3 3 Prognosis Score Percentage 5 year survival 2.0 to 2.4 93% 2.5 to 3.4 85% 3.5 to 5.4 70% >5.4 50% This data was originally published in 1992. It should be emphasised that other factors such as vascular invasion and receptor status also impact on survival and are not included in this data and account for varying prognoses often cited in the literature. References For guidance on how breast cancer is managed in the United Kingdom visit the Association of Breast Surgery website (www.https://associationofbreastsurgery.org.uk/).

Answer 1193

Acute neurological deterioration in premature neonates is usually due to intraventricular haemorrhage. Diagnosis is made by cranial ultrasound. Development of hydrocephalus may necessitate surgery. Intra cranial haemorrhage Extradural haematoma Bleeding into the space between the dura mater and the skull. Often results from acceleration-deceleration trauma or a blow to the side of the head. The majority of extradural haematomas occur in the temporal region where skull fractures cause a rupture of the middle meningeal artery. Features Raised intracranial pressure Some patients may exhibit a lucid interval Subdural haematoma Bleeding into the outermost meningeal layer. Most commonly occur around the frontal and parietal lobes. May be either acute or chronic. Risk factors include old age and alcoholism. Slower onset of symptoms than a extradural haematoma. Intracerebral haematoma Usually hyperdense lesions on CT scanning. Arise in areas of traumatic contusion which fuse to become a haematoma. Areas of clot and fresh blood may co-exist on the same CT scan (Swirl sign). Large haematomas and those associated with mass effect should be evacuated. Subarachnoid haemorrhage Usually occurs spontaneously in the context of a ruptured cerebral aneurysm but may be seen in association with other injuries when a patient has sustained a traumatic brain injury Intraventricular haemorrhage Haemorrhage that occurs into the ventricular system of the brain. It is relatively rare in adult surgical practice and when it does occur, it is typically associated with severe head injuries. In premature neonates it may occur spontaneously. The blood may clot and occlude CSF flow, hydrocephalus may result. In neonatal practice the vast majority of IVH occur in the first 72 hours after birth, the aetiology is not well understood and it is suggested to occur as a result of birth trauma combined with cellular hypoxia, together with the delicate neonatal CNS.

Answer 1194

A femoro-distal bypass graft would carry a high risk of failure and risk of peri-operative myocardial infarct. This lady would be well suited to primary amputation as she is not ambulant. Peripheral vascular disease Indications for surgery to revascularise the lower limb Intermittent claudication Critical ischaemia Ulceration Gangrene Intermittent claudication that is not disabling may provide a relative indication, whilst the other complaints are often absolute indications depending upon the frailty of the patient. Assessment Clinical examination Ankle brachial pressure index measurement Duplex arterial ultrasound Angiography (standard, CT or MRI): usually performed only if intervention being considered. Angioplasty In order for angioplasty to be undertaken successfully the artery has to be accessible. The lesion relatively short and reasonable distal vessel runoff. Longer lesions may be amenable to sub-intimal angioplasty. Surgery Surgery will be undertaken where attempts at angioplasty have either failed or are unsuitable. Bypass essentially involves bypassing the affected arterial segment by utilising a graft to run from above the disease to below the disease. As with angioplasty good runoff improves the outcome. Some key concepts with bypass surgery Superficial femoral artery occlusion to the above knee popliteal In the ideal scenario, vein (either in situ or reversed LSV) would be used as a conduit. However, prosthetic material has reasonable 5 year patency rates and some would advocate using this in preference to vein so that vein can be used for other procedures in the future. In general terms either technique is usually associated with an excellent outcome (if run off satisfactory). Procedure Artery dissected out, IV heparin 3,000 units given and then the vessels are cross clamped Longitudinal arteriotomy Graft cut to size and tunneled to arteriotomy sites Anastomosis to femoral artery usually with 5/0 'double ended' Prolene suture Distal anastomosis usually using 6/0 'double ended' Prolene Distal disease Femoro-distal bypass surgery takes longer to perform, is more technically challenging and has higher failure rates. In elderly diabetic patients with poor runoff a primary amputation may well be a safer and more effective option. There is no point in embarking on this type of surgery in patients who are wheelchair bound. In femorodistal bypasses vein gives superior outcomes to PTFE. Rules Vein mapping 1st to see whether there is suitable vein (the preferred conduit). Sub intimal hyperplasia occurs early when PTFE is used for the distal anastomosis and will lead to early graft occlusion and failure. Essential operative procedure as for above knee fem-pop. If there is insufficient vein for the entire conduit then vein can be attached to the end of the PTFE graft and then used for the distal anastomosis. This type of 'vein boot' is technically referred to as a Miller Cuff and is associated with better patency rates than PTFE alone. Remember the more distal the arterial anastomosis the lower the success rate. References Peach G et al. Diagnosis and management of peripheral arterial disease. BMJ 2012; 345: 36-41.

Answer 1195

The mitral valve is best auscultated over the cardiac apex, where its closure marks the first heart sound. It has only two cusps. These are attached to chordae tendinae which themselves are linked to the wall of the ventricle by the papillary muscles. Heart anatomy The walls of each cardiac chamber comprise: Epicardium Myocardium Endocardium Cardiac muscle is attached to the cardiac fibrous skeleton. Relations The heart and roots of the great vessels within the pericardial sac are related to the posterior aspect of the sternum, medial ends of the 3rd to 5th ribs on the left and their associated costal cartilages. The heart and pericardial sac are situated obliquely two thirds to the left and one third to the right of the median plane. The pulmonary valve lies at the level of the left third costal cartilage. The mitral valve lies at the level of the fourth costal cartilage. Coronary sinus This lies in the posterior part of the coronary groove and receives blood from the cardiac veins. The great cardiac vein lies at its left and the middle and small cardiac veins lie on its right. The smallest cardiac vein (anterior cardiac vein) drains into the right atrium directly. Aortic sinus Right coronary artery arises from the right aortic sinus, the left is derived from the left aortic sinus, which lies posteriorly. Features of the left ventricle as opposed to the right Structure Left Ventricle A-V Valve Mitral (double leaflet) Walls Twice as thick as right Trabeculae carnae Much thicker and more numerous Right coronary artery The RCA supplies: Right atrium Diaphragmatic part of the right ventricle Usually the posterior third of the interventricular septum The sino atrial node (60% cases) The atrio ventricular node (80% cases) Left coronary artery The LCA supplies: Left atrium Most of left ventricle Part of the right ventricle Anterior two thirds of the inter ventricular septum The sino atrial node (remaining 40% cases) Innervation of the heart Autonomic nerve fibres from the superficial and deep cardiac plexus. These lie anterior to the bifurcation of the trachea, posterior to the ascending aorta and superior to the bifurcation of the pulmonary trunk. The parasympathetic supply to the heart is from presynaptic fibres of the vagus nerves. Valves of the heart Mitral valve Aortic valve Pulmonary valve Tricuspid valve 2 cusps 3 cusps 3 cusps 3 cusps First heart sound Second heart sound Second heart sound First heart sound 1 anterior cusp 2 anterior cusps 2 anterior cusps 2 anterior cusps Attached to chordae tendinae No chordae No chordae Attached to chordae tendinae

Answer 1196

The criteria for brainstem death testing are pre-requisites which must be met before testing can occur, these include excluding hypothyroidism, presence of sedatives, hypothermia. The tests themselves comprise: a torch is shone into both eyes to see if they react to the light the eye, is stroked with a tissue or piece of cotton wool to see if it reacts pressure is applied to the forehead and the nose is pinched to see if there's any movement in response ice-cold water is inserted into each ear, which would usually cause the eyes to move a thin plastic tube is placed down the windpipe to see if it provokes gagging or coughing the person is disconnected from the ventilator for a short period of time to see if they make any attempt to breathe on their own, they are pre-oxygenated to avoid hypoxia Brain stem death testing Conditions for brainstem death testing 1. There must be an identifiable pathology causing irremediable brain damage. This may be intra - or extra - cranial. 2. The patient must be deeply unconscious. a. Hypothermia must be excluded as the cause of unconsciousness and the patients core temperature should be over 34oC. b. There should be no evidence that the patients state is due to depressant drugs. This refers to narcotics, hypnotics and tranquillisers as well as neuromuscular blocking drugs. A careful drug history is required, whilst drug levels and antagonists may need to be used. c. Potentially reversible circulatory, metabolic and endocrine disturbances must have been excluded as the cause of the continuing unconsciousness. Some of these disturbances may occur as a result of the condition rather than the cause and these do not preclude the diagnosis of brain stem death. 3. The patient must be apnoeic, needing mechanical ventilation. This condition must not be secondary to the effect of sedative drugs of neuromuscular blockade. This may require testing with a nerve stimulator to show intact neuromuscular transmission. Alternatively, demonstration of tendon reflexes can also demonstrate intact transmission Criteria for brain death Fixed pupils which do not respond to sharp changes in the intensity of incident light No corneal reflex Absent oculo-vestibular reflexes - no eye movements following the slow injection of at least 50ml of ice-cold water into each ear in turn (the caloric test) No response to supraorbital pressure No cough reflex to bronchial stimulation or gagging response to pharyngeal stimulation No observed respiratory effort in response to disconnection of the ventilator for long enough (typically 5 minutes) to ensure elevation of the arterial partial pressure of carbon dioxide to at least 6.0 kPa (6.5 kPa in patients with chronic carbon dioxide retention). Adequate oxygenation is ensured by pre-oxygenation and diffusion oxygenation during the disconnection (so the brain stem respiratory centre is not challenged by the ultimate, anoxic, drive stimulus) The test should be undertaken by two appropriately experienced doctors on two separate occasions.

Answer 1197

Achalasia is a rare condition. However, even once treated there is an increased risk of malignancy. When it does occur it is most likely to be of squamous cell type. Oesophageal cancer - Incidence is increasing In most cases in the Western world this increase is accounted for by a rise in the number of cases of adenocarcinoma. In the UK adenocarcinomas account for 65% of cases. Barretts oesophagus is a major risk factor for most cases of oesophageal adenocarcinoma. In other regions of the world squamous cancer is more common and is linked to smoking, alcohol intake, diets rich in nitrosamines and achalasia. Surveillance of Barretts is important, as it imparts a 30 fold increase in cancer risk and if invasive malignancy is diagnosed early then survival may approach 85% at 5 years. Diagnosis Upper GI endoscopy is the first line test Contrast swallow may be of benefit in classifying benign motility disorders but has no place in the assessment of tumours Staging is initially undertaken with CT scanning of the chest, abdomen and pelvis. If overt metastatic disease is identified using this modality then further complex imaging is unnecessary If CT does not show metastatic disease, then local stage may be more accurately assessed by use of endoscopic ultrasound. Staging laparoscopy is performed to detect occult peritoneal disease. PET CT is performed in those with negative laparoscopy. Thoracoscopy is not routinely performed. Treatment Operable disease is best managed by surgical resection. The most standard procedure is an Ivor- Lewis type oesophagectomy. This procedure involves the mobilisation of the stomach and division of the oesophageal hiatus. The abdomen is closed and a right sided thoracotomy performed. The stomach is brought into the chest and the oesophagus mobilised further. An intrathoracic oesophagogastric anastomosis is constructed. Alternative surgical strategies include a transhiatal resection (for distal lesions), a left thoraco-abdominal resection (difficult access due to thoracic aorta) and a total oesophagectomy (McKeown) with a cervical oesophagogastric anastomosis. The biggest surgical challenge is that of anastomotic leak, with an intrathoracic anastomosis this will result in mediastinitis. With high mortality. The McKeown technique has an intrinsically lower systemic insult in the event of anastomotic leakage. In addition to surgical resection many patients will be treated with adjuvant chemotherapy.

Answer 1198

A pelvic fracture and highly displaced prostate should indicate a diagnosis of membranous urethral rupture. Lower genitourinary tract trauma Most bladder injuries occur due to blunt trauma 85% associated with pelvic fractures Easily overlooked during assessment in trauma Up to 10% of male pelvic fractures are associated with urethral or bladder injuries Types of injury Urethral injury Mainly in males Blood at the meatus (50% cases) There are 2 types: i.Bulbar rupture - most common - straddle type injury e.g. bicycles - triad signs: urinary retention, perineal haematoma, blood at the meatus ii. Membranous rupture - can be extra or intraperitoneal - commonly due to pelvic fracture - Penile or perineal oedema/ hematoma - PR: prostate displaced upwards (beware co-existing retroperitoneal haematomas as they may make examination difficult) - Investigation: ascending urethrogram - Management: suprapubic catheter (surgical placement, not percutaneously) External genitalia injuries (i.e., the penis and the scrotum) Secondary to injuries caused by penetration, blunt trauma, continence- or sexual pleasure-enhancing devices, and mutilation Bladder injury rupture is intra or extraperitoneal presents with haematuria or suprapubic pain history of pelvic fracture and inability to void: always suspect bladder or urethral injury inability to retrieve all fluid used to irrigate the bladder through a Foley catheter indicates bladder injury investigation- IVU or cystogram management: laparotomy if intraperitoneal, conservative if extraperitoneal

Answer 1199

The ulnar nerve arises from the medial cord of the brachial plexus (C8, T1 and contribution from C7). The nerve descends between the axillary artery and vein, posterior to the cutaneous nerve of the forearm and then lies anterior to triceps on the medial side of the brachial artery. In the distal half of the arm it passes through the medial intermuscular septum, and continues between this structure and the medial head of triceps to enter the forearm between the medial epicondyle of the humerus and the olecranon. It may be injured at this site in this scenario. Ulnar nerve Origin C8, T1 Supplies (no muscles in the upper arm) Flexor carpi ulnaris Flexor digitorum profundus Flexor digiti minimi Abductor digiti minimi Opponens digiti minimi Adductor pollicis Interossei muscle Third and fourth lumbricals Palmaris brevis Path Posteromedial aspect of upper arm to flexor compartment of forearm, then along the ulnar. Passes beneath the flexor carpi ulnaris muscle, then superficially over the flexor retinaculum into the palm of the hand. Branches Branch Supplies Muscular branch Flexor carpi ulnaris Medial half of the flexor digitorum profundus Palmar cutaneous branch (Arises near the middle of the forearm) Skin on the medial part of the palm Dorsal cutaneous branch Dorsal surface of the medial part of the hand Superficial branch Cutaneous fibres to the anterior surfaces of the medial one and one-half digits Deep branch Hypothenar muscles All the interosseous muscles Third and fourth lumbricals Adductor pollicis Medial head of the flexor pollicis brevis Effects of injury Damage at the wrist Wasting and paralysis of intrinsic hand muscles (claw hand) Wasting and paralysis of hypothenar muscles Loss of sensation medial 1 and half fingers Damage at the elbow Radial deviation of the wrist Clawing less in 4th and 5th digits

Answer 1200

All of the situations listed are indications for parathyroidectomy. See below for more information. Parathyroid glands and disorders of calcium metabolism Hyperparathyroidism Disease type Hormone profile Clinical features Cause Primary hyperparathyroidism PTH (Elevated) Ca2+ (Elevated) Phosphate (Low) Urine calcium : creatinine clearance ratio > 0.01 May be asymptomatic if mild Recurrent abdominal pain (pancreatitis, renal colic) Changes to emotional or cognitive state Most cases due to solitary adenoma (80%), multifocal disease occurs in 10-15% and parathyroid carcinoma in 1% or less Secondary hyperparathyroidism PTH (Elevated) Ca2+ (Low or normal) Phosphate (Elevated) Vitamin D levels (Low) May have few symptoms Eventually may develop bone disease, osteitis fibrosa cystica and soft tissue calcifications Parathyroid gland hyperplasia occurs as a result of low calcium, almost always in a setting of chronic renal failure Tertiary hyperparathyroidism Ca2+ (Normal or high) PTH (Elevated) Phosphate levels (Decreased or Normal) Vitamin D (Normal or decreased) Alkaline phosphatase (Elevated) Metastatic calcification Bone pain and / or fracture Nephrolithiasis Pancreatitis Occurs as a result of ongoing hyperplasia of the parathyroid glands after correction of underlying renal disorder, hyperplasia of all 4 glands is usually the cause Differential diagnoses It is important to consider the rare but relatively benign condition of benign familial hypocalciuric hypercalcaemia, caused by an autosomal dominant genetic disorder. Diagnosis is usually made by genetic testing and concordant biochemistry (urine calcium : creatinine clearance ratio <0.01-distinguished from primary hyperparathyroidism). Treatment Primary hyperparathyroidism Indications for surgery Elevated serum Calcium > 1mg/dL above normal Hypercalciuria > 400mg/day Creatinine clearance < 30% compared with normal Episode of life threatening hypercalcaemia Nephrolithiasis Age < 50 years Neuromuscular symptoms Reduction in bone mineral density of the femoral neck, lumbar spine, or distal radius of more than 2.5 standard deviations below peak bone mass (T score lower than -2.5) Secondary hyperparathyroidism Usually managed with medical therapy. Indications for surgery in secondary (renal) hyperparathyroidism: Bone pain Persistent pruritus Soft tissue calcifications Tertiary hyperparathyroidism Allow 12 months to elapse following transplant as many cases will resolve The presence of an autonomously functioning parathyroid gland may require surgery. If the culprit gland can be identified then it should be excised. Otherwise total parathyroidectomy and re-implantation of part of the gland may be required. References 1. Insogna K. Primary Hyperparathyroidism. N Engl J Med. 2018 Sep 13;379(11):1050-1059. 2. van der Plas W Y et al. Secondary and Tertiary Hyperparathyroidism: A Narrative Review. Scand J Surg. 2020 Dec;109(4):271-278.

Answer 1201

Acromioclavicular joint (ACJ) dislocation normally occurs secondary to direct injury to the superior aspect of the acromion. Loss of shoulder contour and prominent clavicle are key features. Note; rotator cuff tears rarely occur in the third decade. Shoulder disorders Shoulder fractures and dislocations Fractures Proximal humerus Background Third most common fragility fracture in the elderly. Results from low energy fall in predominantly elderly females, or from high energy trauma in young males. Can be associated with nerve injury (commonly axillary), and fracture-dislocation of the humeral head. Detailed neurological assessment is essential for all upper limb injuries. Anatomy Osteology Consists of articular head, greater tuberosity, lesser tuberosity, metaphysis and diaphysis. Between the articular head and the tuberosities is the anatomical neck (previous physis). Between the tuberosities and the metaphysis is the surgical neck. The supraspinatus, infraspinatus and teres minor muscles attach to the greater tuberosity. The subscapularis muscle attaches to the lesser tuberosity. Vascular Supply Humeral head is supplied by the anterior and posterior humeral circumflex arteries. Anatomical neck fractures are at greatest risk of osteonecrosis. Imaging Imaging aims to both delineate the fracture pattern, and confirm/exlude the presence of an associated dislocation. Radiographs - True anteroposterior (AP), axillary lateral and/or scapula Y view. CT - indicated to better define intra-articular involvement and to aid pre-operative planning. MRI is not useful for fracture imaging. Classification Description of the fracture is often more useful than classification. Particular attention should be paid to humeral alignment, fracture displacement, and greater tuberosity position (rotator cuff will pull the GT supero-posterioly, which can cause impingement problems with malunion). - Neer Classification: Most commonly used. Describes fracture as 2,3,or 4 part depending upon the number main fragments. Also comments on the degree of displacement. Fragments: -greater tuberosity -lesser tuberosity - articular surface - shaft Displacement: >1cm or angulation >45 degrees. Treatment The vast majority of proximal humeral fractures are minimally displaced, and therefore can be managed conservatively. This involves immobilisation in a polysling, and progressive mobilisation. Pendular exercise can commence at 14 days, and active abduction from 4-6 weeks. Irreducible fracture dislocation is an indication for operative management. Other indications include large displacement, younger patient, head splitting (intra-articular fractures). However, the recent PROFHER trial (1) has suggested no benefit to operative intervention on patient outcome (it must be applied cautiously as majority of patients were elderly with extraarticular fractures). Options available for surgical management include: ORIF Most commonly used. Plate and screw fixation. Can reconstruct complex fractures. Intramedullary nail Suitable for extra-articular configuration, predominantly surgical neck +/- GT fractures. Hemiarthroplasty Used for un-reconstructable fractures in the older patient who has good glenoid quality. Total shoulder arthroplasty Unconstructable fractures where high functioning shoulder is required (hemiarthroplasty will cause glenoid erosion) Reverse shoulder arthroplasty Total shoulder arthroplasty that provides better functional outcome than conventional total shoulder replacement. Scapula Background Uncommon fractures usually associated with high energy trauma. Most commonly involve scapula body or spine (50%), glenoid fossa and glenoid neck. Important to exclude associated life threatening injury. Imaging Plain radiographs should include true anteroposterior (AP), axillary lateral and/or scapula Y view. CT scanning is useful for defining intra-articular involvement, displacement and for three dimensional reconstruction. Classification Based on the location of the fracture (coracoid, acromion, glenoid neck, glenoid fossa, scapula body). Beware of ipsilateral glenoid neck and clavicle fracture -floating shoulder - where limb is effectively dissociated from axial skeleton. Treatment The vast majority of scapula fractures are amenable to conservative management, consisting of sling immobilisation for two weeks followed by early rehabilitation. Floating shoulder will usually require fixation, and consideration of surgery should also be given to intra-articular and displaced/angulated glenoid fractures. Dislocations Types Dislocations around the shoulder joint include glenohumeral dislocation, acromioclavicular joint disruption and sternoclavicular dislocation. Only glenohumeral dislocation will be covered here. Glenohumeral dislocation Diagnosis, classification and management are covered here. Background Shoulder dislocation is commonly seen in A&E. It has a high recurrence rate that is as high as 80% in teenagers. Initial management requires emergent reduction to prevent lasting chondral damage. Early assessment and management Usually a traumatic cause (multi-directional instability in frequent dislocations requires discussion with orthopaedics and is not covered here). Careful history, examination and documentation of neurovascular status of the limb, in particular the axillary nerve (regimental badge sensation). This should be re-assessed post manipulation. Early radiographs to confirm direction of dislocation. Initial management consists of emergent closed reduction under under entanox and analgesia, but often requires conscious sedation. Arm should then be immobilised in a polysling, and XR to confirm relocation. Imaging - True anteroposterior (AP), axillary lateral and/or scapula Y view. Reduced humeral head should lie between acromion and coracoid on lateral/scapula view. Types Direction Features Cause Examination Reduction techniques Anterior Most Common >90% Usually traumatic - anterior force on arm when shoulder is abducted, externally rotated Loss of shoulder contour - sulcus sign. Humeral head can be felt anteriorly. Hippocratic. Milch. Stimson. Kocher not advised due to complication of fracture Posterior 50% missed in A&E 50% traumatic, but classically post seizure or electrocution Shoulder locked in internal rotation. XR may show lightbulb appearance. Gentle lateral traction to adducted arm. Inferior Rare Associated with pectorals and rotator cuff tears, and glenoid fracture As for primary injury Management of primary injury Superior Rare Associated with acrominon/clavicle fracture As for primary injury Management of primary injury Associated injuries Bankart lesion - avulsion of the anterior glenoid labrum with an anterior shoulder dislocation (reverse Bankart if poster labrum in posterior dislocation). Hill Sachs defect - chondral impaction on posteriosuperior humeral head from contact with gleonoid rim. Can be large enough to lock shoulder, requiring open reduction. (Reverse Hill Sachs in posterior dislocation). Rotator cuff tear - increases with age. Greater or lesser tuberosity fracture - increases with age. Humeral neck fracture - shoulder fracture dislocation. More common in high energy trauma and elderly. Should be discussed with orthopaedics prior to any attempted reduction. Rotator Cuff Disease Rotator cuff disease is a spectrum of conditions that ranges from subacromial impingement to rotator cuff tears and eventually to rotator cuff arthropathy (arthritis). Anatomy The rotator cuff is a group of four muscles that are important in shoulder movements, and maintenance of glenohumeral stability. Muscle Scapular attachment Humeral attachment Action Innervation Supraspinatus Supraspinatus fossa Superior facet of greater tuberosity Initiation of abduction of humerus Suprascapular nerve Infraspinatus Infraspinatus fossa Posterior facet of greater tuberosity External rotation of humerus Suprascapular nerve Teres Minor Lateral border Inferior facet of greater tuberosity External rotation of humerus Axillary Nerve Subscapularis Subscapular fossa Lesser tuberosity Internal rotation of humerus Upper and lower subscapular nerve The inferior rotator cuff muscles (infraspinatus, teres minor, and subscapularis) balance the superior pull of the deltoid. Injury/tear results in upward migration of the humeral head on the glenoid (can be seen on AP radiograph). Likewise, the anterior muscles (subscapularis) are balanced with the posterior muscles (infraspinatus, teres minor). Subacromial Impingement The most common cause of shoulder pain, which results from impingement of the superior cuff on the undersurface of the acromion, and an inflammatory bursitis. Associated with certain types of acromial morphology (Bigliani classification). Presents as insidious pain which is exacerbated by overhead activities. Rotator Cuff Tear Often presents as an acute event on the background of chronic subacromial impingement in the older patient, but can present as an avulsion injury in younger patients. Majority of tears are to the superior cuff (supraspinatus, infraspinatus, teres minor), though a tear to subscapularis is associated with subcoracoid impingement. Tears present as pain and weakness when using the muscles in question. Rotator Cuff Arthropathy Defined as shoulder arthritis in the setting of rotator cuff dysfunction. Results from superior migration due to the loss of rotator cuff function and integrity. Unopposed deltoid pulls the humeral head superiorly. Associated with massive chronic cuff tears. Imaging Plain radiographs AP of the shoulder may show superior migration of the humerus with a cuff tear, and features of arthritis with arthropathy. Other causes of pain may also be identified (e.g. calcific tendonitis/fracture) Outlet view is useful for defining the acromial morphology USS Allows dynamic imaging of the cuff, and is inexpensive. However, it is very user dependent. MRI Best imaging modality for cuff pathology. Also allows imaging of the rest of the shoulder. When intra-articular pathology is suspected, can be combined with an arthrogram for improved sensitivity and specificity. Treatment Subacromial impingement Physiotherapy, oral anti-inflammatory medication Subacromial steroid injection can settle inflammation Arthroscopic subacromial decompression by shaving away the undersurface of the acromion, more space is created for the rotator cuff. Cuff integrity is assessed also at time of surgery, and can be repaired if necessary. Rotator cuff tear When considering repair of a cuff tear, the age and activity of the patient, the nature of the tear (degenerative vs. acute traumatic), and the size and retraction of the tear should be considered when making a surgical plan. Mild tears or tears in the elderly can be managed conservatively, as outlined above. Moderate tears can be repaired arthroscopically. Massive or retracted tears will often require an open repair (occasionally with a tendon transfer). Subacromial decompression is performed at the same time to reduce impingement, symptoms and recurrence. Calcific tendonitis Calcific tendonitis involves calcific deposits within tendons anywhere in the body, but most commonly in the rotator cuff (specifically the supraspinatus tendon). When present in the shoulder, it is associated with subacromial impingement and pain. Pathology More common in women aged 30-60 years. Association with diabetes and hypothyroidism There are three stages of calcification Formative phase characterized by calcific deposits Resting phase deposit is stable, but presents with impingement problems Resorptive phase phagocytic resorption. Most painful stage. Presentation Similar in presentation to subacromial impingement, with pain especially with over head activities. Atraumatic in nature. Imaging Plain radiographs show calcification of the rotator cuff, usually within 1.5cm of its insertion on the humerus. Supraspinatus outlet views can show level of impingment. Further imaging is rarely needed. Treatment Non-operative NSAIDS, steroid injection (controversial, but practiced) and physiotherapy. Approximately 75% will resolve by 6 months with conservative management. Ultrasound guided or surgical needle barbotage can break down deposits and resolve symptoms. Occasionally surgical excision is required. Adhesive capsulitis (Frozen Shoulder) Pain and loss of movement of shoulder joint, which involves fibroplastic proliferation of capsular tissue, causing soft tissue scarring and contracture. Patients present with a painful and decreased arc of motion. Associated with prolonged immobilization, previous surgery, thyroid disorders (AI) and diabetes Classically three stages which can take up to two years to resolve: Stage one the freezing and painful stage Stage two the frozen and stiff stage Stage three the thawing stage, where shoulder movement slowly improves Imaging Plain radiographs to exclude other causes of a painful shoulder MRI arthrogram may show capsular contracture, and again may be used to exclude cuff pathology. However, often not performed as diagnosis is largely clinical. Treatment Non-operative NSAIDS, steroid injection and physiotherapy. Patience is required as condition can take up to 2 years to improve. Operative MUA or arthroscopic adhesiolysis (release of adhesions) can expedite recovery, followed by intensive physiotherapy. Glenohumeral Arthritis Background May be osteoarthritis (primary or secondary to cuff tear or trauma), rheumatoid arthritis, or as part of a spondyloarthropathy. Majority of those with RA will develop symptoms. More common in the elderly Presents like any other arthritis - pain at night and with movement Imaging AP and axillary radiographs will show features of arthritis. CT/MRI is often useful to classify the shape of the glenoid and extent of bone loss when considering arthroplasty. MRI also essential to asses integrity of rotator cuff if considering shoulder replacement. Treatment Like all orthopaedics, start with simple measures: NSAIDS, management of RA, physiotherapy, steroid injection. Hemiarthroplasty can sometimes be considered if glenoid is in excellent condition or if patient has large comorbidity. Arthroscopic debridement is useful if patient has isolated ACJ arthritis, but is rarely used for glenohumeral arthritis. Total shoulder replacement is shown to produce superior outcome when compared to hemiarthroplasty in terms of pain relief, function and implant survival. Total shoulder replacement can be anatomical (ball on humerus, with cup on glenoid), or reverse geometry (ball on glenoid, with cup on humerus). Anatomical TSR requires an in tact rotator cuff, so often reverse is preferable when the cuff if questionable in integrity. References 1. JAMA. 2015;313(10):1037-1047. doi:10.1001/jama.2015.1629

Answer 1202

Causes of avascular necrosis P ancreatitis L upus A lcohol S teroids T rauma I diopathic, infection C aisson disease, collagen vascular disease R adiation, rheumatoid arthritis A myloid G aucher disease S ickle cell disease Steroid containing therapy for myeloma may induce avascular necrosis, however the disease itself does not cause it. Caisson disease as may occur in deep sea divers is a recognised cause.

Answer 1203

This patient has a trendelenburg gait caused by damage to the superior gluteal nerve causing weakness of the abductor muscles. Classically a patient is asked to stand on one leg and the pelvis dips on the opposite side. The absence of a foot drop excludes the possibility of polio or L5 radiculopathy. Gluteal region Gluteal muscles Gluteus maximus: inserts to gluteal tuberosity of the femur and iliotibial tract Gluteus medius: attach to lateral greater trochanter Gluteus minimis: attach to anterior greater trochanter All extend and abduct the hip Deep lateral hip rotators Piriformis Gemelli Obturator internus Quadratus femoris Nerves Superior gluteal nerve (L4,L5, S1) Gluteus medius Gluteus minimis Tensor fascia lata Inferior gluteal nerve (L5, S1, S2) Gluteus maximus Damage to the superior gluteal nerve will result in the patient developing a Trendelenberg gait. Affected patients are unable to abduct the thigh at the hip joint. During the stance phase, the weakened abductor muscles allow the pelvis to tilt down on the opposite side. To compensate, the trunk lurches to the weakened side to attempt to maintain a level pelvis throughout the gait cycle. The pelvis sags on the opposite side of the lesioned superior gluteal nerve.

Answer 1204

The dorsalis pedis artery is a direct continuation of the anterior tibial artery. Foot- anatomy Arches of the foot The foot is conventionally considered to have two arches. The longitudinal arch is higher on the medial than on the lateral side. The posterior part of the calcaneum forms a posterior pillar to support the arch. The lateral part of this structure passes via the cuboid bone and the lateral two metatarsal bones. The medial part of this structure is more important. The head of the talus marks the summit of this arch, located between the sustentaculum tali and the navicular bone. The anterior pillar of the medial arch is composed of the navicular bone, the three cuneiforms and the medial three metatarsal bones. The transverse arch is situated on the anterior part of the tarsus and the posterior part of the metatarsus. The cuneiforms and metatarsal bases narrow inferiorly, which contributes to the shape of the arch. Intertarsal joints Sub talar joint Formed by the cylindrical facet on the lower surface of the body of the talus and the posterior facet on the upper surface of the calcaneus. The facet on the talus is concave anteroposteriorly, the other is convex. The synovial cavity of this joint does not communicate with any other joint. Talocalcaneonavicular joint The anterior part of the socket is formed by the concave articular surface of the navicular bone, posteriorly by the upper surface of the sustentaculum tali. The talus sits within this socket Calcaneocuboid joint Highest point in the lateral part of the longitudinal arch. The lower aspect of this joint is reinforced by the long plantar and plantar calcaneocuboid ligaments. Transverse tarsal joint The talocalcaneonavicular joint and the calcaneocuboid joint extend across the tarsus in an irregular transverse plane, between the talus and calcaneus behind and the navicular and cuboid bones in front. This plane is termed the transverse tarsal joint. Cuneonavicular joint Formed between the convex anterior surface of the navicular bone and the concave surface of the the posterior ends of the three cuneiforms. Intercuneiform joints Between the three cuneiform bones. Cuneocuboid joint Between the circular facets on the lateral cuneiform bone and the cuboid. This joint contributes to the tarsal part of the transverse arch. A detailed knowledge of the joints is not required for MRCS Part A. However, the contribution they play to the overall structure of the foot should be appreciated Muscles of the foot Muscle Origin Insertion Nerve supply Action Abductor hallucis Medial side of the calcaneus, flexor retinaculum, plantar aponeurosis Medial side of the base of the proximal phalanx Medial plantar nerve Abducts the great toe Flexor digitorum brevis Medial process of the calcaneus, plantar eponeurosis. Via 4 tendons into the middle phalanges of the lateral 4 toes. Medial plantar nerve Flexes all the joints of the lateral 4 toes except for the interphalangeal joint. Abductor digit minimi From the tubercle of the calcaneus and from the plantar aponeurosis Together with flexor digit minimi brevis into the lateral side of the base of the proximal phalanx of the little toe Lateral plantar nerve Abducts the little toe at the metatarsophalangeal joint Flexor hallucis brevis From the medial side of the plantar surface of the cuboid bone, from the adjacent part of the lateral cuneiform bone and from the tendon of tibialis posterior. Into the proximal phalanx of the great toe, the tendon contains a sesamoid bone Medial plantar nerve Flexes the metatarsophalangeal joint of the great toe. Adductor hallucis Arises from two heads. The oblique head arises from the sheath of the peroneus longus tendon, and from the plantar surfaces of the bases of the 2nd, 3rd and 4th metatarsal bones. The transverse head arises from the plantar surface of the lateral 4 metatarsophalangeal joints and from the deep transverse metatarsal ligament. Lateral side of the base of the proximal phalanx of the great toe. Lateral plantar nerve Adducts the great toe towards the second toe. Helps maintain the transverse arch of the foot. Extensor digitorum brevis On the dorsal surface of the foot from the upper surface of the calcaneus and its associated fascia Via four thin tendons which run forward and medially to be inserted into the medial four toes. The lateral three tendons join with hoods of extensor digitorum longus. Deep peroneal Extend the metatarsophalangeal joint of the medial four toes. It is unable to extend the interphalangeal joint without the assistance of the lumbrical muscles. Nerves in the foot Lateral plantar nerve Passes anterolaterally towards the base of the 5th metatarsal between flexor digitorum brevis and flexor accessorius. On the medial aspect of the lateral plantar artery. At the base of the 5th metatarsal it splits into superficial and deep branches. Medial plantar nerve Passes forwards with the medial plantar artery under the cover of the flexor retinaculum to the interval between abductor hallucis and flexor digitorum brevis on the sole of the foot. Plantar arteries Arise under the cover of the flexor retinaculum, midway between the tip of the medial malleolus and the most prominent part of the medial side of the heel. Medial plantar artery. Passes forwards medial to medial plantar nerve in the space between abductor hallucis and flexor digitorum brevis.Ends by uniting with a branch of the 1st plantar metatarsal artery. Lateral plantar artery. Runs obliquely across the sole of the foot. It lies lateral to the lateral plantar nerve. At the base of the 5th metatarsal bone it arches medially across the foot on the metatarsals Dorsalis pedis artery This vessel is a direct continuation of the anterior tibial artery. It commences on the front of the ankle joint and runs to the proximal end of the first metatarsal space. Here is gives off the arcuate artery and continues forwards as the first dorsal metatarsal artery. It is accompanied by two veins throughout its length. It is crossed by the extensor hallucis brevis

Answer 1205

Since this is a long claudication distance it may be that only a minor lesion is present. Whilst resting ABPI may be normal, they are usually abnormal following exercise. Ankle-Brachial pressure index Measurement of ankle- brachial pressure index (ABPI) is a commonly performed vascular investigation. Calculated by dividing lower limb pressure by the highest upper limb pressure. Results of ABPI 1.2 or greater Usually due to vessel calcification 1.0- 1.2 Normal 0.8-1.0 Minor stenotic lesion Initiate risk factor management 0.50-0.8 Moderate stenotic lesion Consider duplex Risk factor management If mixed ulcers present then avoid tight compression bandages 0.3 - 0.5 Likely significant stenosis Duplex scanning to delineate lesions needed Compression bandaging contra indicated Less than 0.3 Indicative of critical ischaemia Urgent detailed imaging required

Answer 1206

Ankylosing spondylitis is associated with HLA B27, there is a strong association with ulcerative colitis in such individuals. The clinical findings are usually of a kyphosis affecting the cervical and thoracic spine. Considerable symptomatic benefit may be obtained using non steroidal anti inflammatory drugs. These should be used carefully in patients with inflammatory bowel disease who may be taking steroids. Diseases affecting the vertebral column Ankylosing spondylitis Chronic inflammatory disorder affecting the axial skeleton Sacro-ilitis is a usually visible in plain films Up to 20% of those who are HLA B27 positive will develop the condition Affected articulations develop bony or fibrous changes Typical spinal features include loss of the lumbar lordosis and progressive kyphosis of the cervico-thoracic spine Scheuermann's disease Epiphysitis of the vertebral joints is the main pathological process Predominantly affects adolescents Symptoms include back pain and stiffness X-ray changes include epiphyseal plate disturbance and anterior wedging Clinical features include progressive kyphosis (at least 3 vertebrae must be involved) Minor cases may be managed with physiotherapy and analgesia, more severe cases may require bracing or surgical stabilisation Scoliosis Consists of curvature of the spine in the coronal plane Divisible into structural and non structural, the latter being commonest in adolescent females who develop minor postural changes only. Postural scoliosis will typically disappear on manoeuvres such as bending forwards Structural scoliosis affects > 1 vertebral body and is divisible into idiopathic, congential and neuromuscular in origin. It is not correctable by alterations in posture Within structural scoliosis, idiopathic is the most common type Severe, or progressive structural disease is often managed surgically with bilateral rod stabilisation of the spine Spina bifida Non fusion of the vertebral arches during embryonic development Three categories; myelomeningocele, spina bifida occulta and meningocele Myelomeningocele is the most severe type with associated neurological defects that may persist in spite of anatomical closure of the defect Up to 10% of the population may have spina bifida occulta, in this condition the skin and tissues (but not not bones) may develop over the distal cord. The site may be identifiable by a birth mark or hair patch The incidence of the condition is reduced by use of folic acid supplements during pregnancy Spondylolysis Congenital or acquired deficiency of the pars interarticularis of the neural arch of a particular vertebral body, usually affects L4/ L5 May be asymptomatic and affects up to 5% of the population Spondylolysis is the commonest cause of spondylolisthesis in children Asymptomatic cases do not require treatment Spondylolisthesis This occurs when one vertebra is displaced relative to its immediate inferior vertebral body May occur as a result of stress fracture or spondylolysis Traumatic cases may show the classic 'Scotty Dog' appearance on plain films Treatment depends upon the extent of deformity and associated neurological symptoms, minor cases may be actively monitored. Individuals with radicular symptoms or signs will usually require spinal decompression and stabilisation

Answer 1207

Tamoxifen is an oestrogen receptor antagonist in breast tissues. However, at other sites, such as the endometrium it may act as an agonist. Hence the reason for increasing risk of endometrial cancer. Tamoxifen Synthetic partial oestrogen agonist, acts primarily by binding to the oestrogen receptor. Half life of 7 days, takes 4 weeks for drug to reach plasma steady state. Should usually be considered in patients with oestrogen receptor positive tumours (alternative agents may be preferred in some groups). Although antagonistic with respects to breast tissue tamoxifen may serve as an agonist at other sites. Therefore risk of endometrial cancer is increased, preservation of bone density and decreased cardiovascular risks. Climateric side effects are common, 3% stop taking the drug because of these. Aromatase inhibitors are an alternative class of drugs, these work by blocking the peripheral aromatization of androgens (post menopausal women produce oestrogens in this way). They may treat cancers for which tamoxifen is no longer effective.

Answer 1208

Medullary thyroid cancers often secrete calcitonin and monitoring the serum levels of this hormone is useful in detecting sub clinical recurrence. Thyroid neoplasms Lesion Common features Follicular adenoma Usually present as a solitary thyroid nodule Malignancy can only be excluded on formal histological assessment Papillary carcinoma Usually contain a mixture of papillary and colloidal filled follicles Histologically tumour has papillary projections and pale empty nuclei Seldom encapsulated Lymph node metastasis predominate Haematogenous metastasis rare Account for 60% of thyroid cancers Follicular carcinoma May appear macroscopically encapsulated, microscopically capsular invasion is seen. Without this finding the lesion is a follicular adenoma. Vascular invasion predominates Multifocal disease rare Account for 20% of all thyroid cancers Anaplastic carcinoma Most common in elderly females Local invasion is a common feature Account for 10% of thyroid cancers Treatment is by resection where possible, palliation may be achieved through isthmusectomy and radiotherapy. Chemotherapy is ineffective. Medullary carcinoma Tumours of the parafollicular cells (C Cells) C cells derived from neural crest and not thyroid tissue Serum calcitonin levels often raised Familial genetic disease accounts for up to 20% cases Both lymphatic and haematogenous metastasis are recognised, nodal disease is associated with a very poor prognosis.

Answer 1209

Menisci have no nerve or blood supply and thus heal poorly. Established tears with associated symptoms are best managed by arthroscopic menisectomy. Knee injury Types of injury Ruptured anterior cruciate ligament Sport injury Mechanism: high twisting force applied to a bent knee Typically presents with: loud crack, pain and RAPID joint swelling (haemoarthrosis) Poor healing Management: intense physiotherapy or surgery Ruptured posterior cruciate ligament Mechanism: hyperextension injuries Tibia lies back on the femur Paradoxical anterior draw test Rupture of medial collateral ligament Mechanism: leg forced into valgus via force outside the leg Knee unstable when put into valgus position Menisceal tear Rotational sporting injuries Delayed knee swelling Joint locking (Patient may develop skills to 'unlock' the knee Recurrent episodes of pain and effusions are common, often following minor trauma Chondromalacia patellae Teenage girls, following an injury to knee e.g. Dislocation patella Typical history of pain on going downstairs or at rest Tenderness, quadriceps wasting Dislocation of the patella Most commonly occurs as a traumatic primary event, either through direct trauma or through severe contraction of quadriceps with knee stretched in valgus and external rotation Genu valgum, tibial torsion and high riding patella are risk factors Skyline x-ray views of patella are required, although displaced patella may be clinically obvious An osteochondral fracture is present in 5% The condition has a 20% recurrence rate Fractured patella 2 types: i. Direct blow to patella causing undisplaced fragments ii. Avulsion fracture Tibial plateau fracture Occur in the elderly (or following significant trauma in young) Mechanism: knee forced into valgus or varus, but the knee fractures before the ligaments rupture Varus injury affects medial plateau and if valgus injury, lateral plateau depressed fracture occurs Classified using the Schatzker system (see below) Schatzker Classification system for tibial plateau fractures Type Anatomical description Features 1 Vertical split of lateral condyle Fracture through dense bone, usually in the young. It may be virtually undisplaced, or the condylar fragment may be pushed inferiorly and tilted 2 Vertical split of the lateral condyle combined with an adjacent load bearing part of the condyle The wedge fragment (which may be of variable size), is displaced laterally; the joint is widened. Untreated, a valgus deformity may develop 3 Depression of the articular surface with intact condylar rim The split does not extend to the edge of the plateau. Depressed fragments may be firmly embedded in subchondral bone, the joint is stable 4 Fragment of the medial tibial condyle Two injuries are seen in this category; (1) a depressed fracture of osteoporotic bone in the elderly. (2) a high energy fracture resulting in a condylar split that runs from the intercondylar eminence to the medial cortex. Associated ligamentous injury may be severe 5 Fracture of both condyles Both condyles fractured but the column of the metaphysis remains in continuity with the tibial shaft 6 Combined condylar and subcondylar fractures High energy fracture with marked comminution

Answer 1210

Infection with Ascaris lumbricoides usually occurs after individuals have visited places like sub Saharan Africa or the far east. Unlike ancylostoma duodenale infection there is usually evidence of both worms and eggs in the stool. The absence of pruritus makes enterobius less likely. The presence of coughing may be due to the migration of the larva through the lungs. Gastro intestinal parasitic infections Common infections Enterobiasis Due to organism Enterobius vermicularis Common cause of pruritus ani Diagnosis usually made by placing scotch tape at the anus, this will trap eggs that can then be viewed microscopically Treatment is with mebendazole Ancylostoma duodenale Hookworms that anchor in proximal small bowel Most infections are asymptomatic although may cause iron deficiency anaemia Larvae may be found in stools left at ambient temperature, otherwise infection is difficult to diagnose Infection occurs as a result of cutaneous penetration, migrates to lungs, coughed up and then swallowed Treatment is with mebendazole Ascariasis Due to infection with roundworm Ascaris lumbricoides Infections begin in gut following ingestion, then penetrate duodenal wall to migrate to lungs, coughed up and swallowed, cycle begins again Diagnosis is made by identification of worm or eggs within faeces Treatment is with mebendazole Strongyloidiasis Due to infection with Strongyloides stercoralis Rare in west Organism is a nematode living in duodenum of host Initial infection is via skin penetration. They then migrate to lungs and are coughed up and swallowed. Then mature in small bowel are excreted and cycle begins again An auto infective cycle is also recognised where larvae will penetrate colonic wall Individuals may be asymptomatic, although they may also have respiratory disease and skin lesions Diagnosis is usually made by stool microscopy In the UK mebendazole is used for treatment Cryptosporidium Protozoal infection Organisms produce cysts which are excreted and thereby cause new infections Symptoms consist of diarrhoea and cramping abdominal pains. Symptoms are worse in immunosuppressed people Cysts may be identified in stools Treatment is with metronidazole Giardiasis Diarrhoeal infection caused by Giardia lamblia (protozoan) Infections occur as a result of ingestion of cysts Symptoms are usually gastrointestinal with abdominal pain, bloating and passage of soft or loose stools Diagnosis is by serology or stool microscopy First line treatment is with metronidazole

Answer 1211

Avoid incisional or punch biopsy of lesions suspected to be melanoma. This may represent a malignant melanoma. Complete excision is required to allow accurate histological assessment. If the diagnosis is confirmed then re-excision of margins may be required. Clearly if the lesion is benign then no further action is required. Treatment of suspicious skin lesions Skin lesions may be referred to surgeons for treatment or discovered incidentally. The table below outlines the various therapeutic options: Method Indication Tru-cut biopsy Most often used for percutaneous sampling of deep seated lesions or used intra operatively for visceral lesions 5mm punch biopsy Used for diagnostic confirmation of lesions that are suspected to be benign or where the definitive management is unlikely to be surgical. Of limited usefulness in pigmented lesions where they do not include sufficient tissue for accurate diagnosis. May be used in non melanoma type skin disease to establish diagnosis prior to more extensive resection. Wide excision Where the complete excision of the lesion (with healthy margins) is the main objective. In cosmetically sensitive sites, or where the defect is large, this may need to be complemented with plastic surgical techniques Incisional biopsy Used mainly for deep seated or extensive lesions where there is diagnostic doubt (usually following core or tru-cut biopsy). Used rarely for skin lesions. Diagnostic excision Primarily used for lesions that are suspicious for melanoma, the lesion is excised with a rim of normal tissue. Excision of margins may be required subsequently.

Answer 1212

This child has VACTERL, which is a combination of Vertebral, Ano-rectal, Cardiac, Tracheo-oesophageal, Renal and Radial limb anomalies. Half of babies with oesophageal atresia will have VACTERL. Problems that occur during feeding are more suggestive of proximal pathology. Paediatric Gastrointestinal disorders Pyloric stenosis M>F 5-10% Family history in parents Projectile non bile stained vomiting at 4-6 weeks of life Diagnosis is made by test feed or USS Treatment: Ramstedt pyloromyotomy (open or laparoscopic) Acute appendicitis Uncommon under 3 years When occurs may present atypically Mesenteric adenitis Central abdominal pain and URTI Conservative management Intussusception Telescoping bowel Proximal to or at the level of, ileocaecal valve 6-9 months age Colicky pain, diarrhoea and vomiting, sausage shaped mass, red jelly stool. Treatment: reduction with air insufflation Malrotation High caecum at the midline Feature in exomphalos, congenital diaphragmatic hernia, intrinsic duodenal atresia May be complicated by development of volvulus, infant with volvulus may have bile stained vomiting Diagnosis is made by upper GI contrast study and USS Treatment is by laparotomy, if volvulus is present (or at high risk of occurring then a ladds procedure is performed Hirschsprung's disease Absence of ganglion cells from myenteric and submucosal plexuses Occurs in 1/5000 births Full thickness rectal biopsy for diagnosis Delayed passage of meconium and abdominal distension Treatment is with rectal washouts initially, thereafter an anorectal pull through procedure Oesophageal atresia Associated with tracheo-oesophageal fistula and polyhydramnios May present with choking and cyanotic spells following aspiration VACTERL associations Meconium ileus Usually delayed passage of meconium and abdominal distension Majority have cystic fibrosis X-Rays may not show a fluid level as the meconium is viscid (depends upon feeding), PR contrast studies may dislodge meconium plugs and be therapeutic Infants who do not respond to PR contrast and NG N-acetyl cysteine will require surgery to remove the plugs Biliary atresia Jaundice > 14 days Increased conjugated bilirubin Urgent Kasai procedure Necrotising enterocolitis Prematurity is the main risk factor Early features include abdominal distension and passage of bloody stools X-Rays may show pneumatosis intestinalis and evidence of free air Increased risk when empirical antibiotics are given to infants beyond 5 days Treatment is with total gut rest and TPN, babies with perforations will require laparotomy

Answer 1213

Risks of abdominal aortic aneurysm rupture (over 5 years): 5-5.9cm = 25% 6-6.9cm= 35% 7cm and over = 75% Aneurysms greater than 5cm in diameter on USS should be formally assessed using CT scanning with arterial phases to delineate anatomy and facilitate surgical planning. Abdominal aorta aneurysm - Abdominal aortic aneurysms are a common problem in vascular surgery. They may occur as either true or false aneurysm. With the former all 3 layers of the arterial wall are involved, in the latter only a single layer of fibrous tissue forms the aneurysm wall. True abdominal aortic aneurysms have an approximate incidence of 0.06 per 1000 people. They are commonest in elderly men and for this reason the UK is now introducing the aneurysm screening program with the aim of performing an abdominal aortic ultrasound measurement in all men aged 65 years. Causes Several different groups of patients suffer from aneurysmal disease. The commonest group is those who suffer from standard arterial disease, i.e. Those who are hypertensive and have been or are smokers. Other patients such as those suffering from connective tissue diseases such as Marfan's may also develop aneurysms. In patients with abdominal aortic aneurysms the extracellular matrix becomes disrupted with a change in the balance of collagen and elastic fibres. Management Most abdominal aortic aneurysms are an incidental finding. Symptoms most often relate to rupture or impending rupture. 20% rupture anteriorly into the peritoneal cavity. Very poor prognosis. 80% rupture posteriorly into the retroperitoneal space The risk of rupture is related to aneurysm size, only 2% of aneurysms measuring less than 4cm in diameter will rupture over a 5 year period. This contrasts with 75% of aneurysms measuring over 7cm in diameter. This is well explained by Laplaces' law which relates size to transmural pressure. For this reason most vascular surgeons will subject patients with an aneurysm size of 5cm or greater to CT scanning of the chest, abdomen and pelvis with the aim of delineating anatomy and planning treatment. Depending upon co-morbidities, surgery is generally offered once the aneurysm is between 5.5cm and 6cm. Indications for surgery Symptomatic aneurysms (80% annual mortality if untreated) Increasing size above 5.5cm if asymptomatic Rupture (100% mortality without surgery) Surgical procedures Abdominal aortic aneurysm repair Procedure: GA Invasive monitoring (A-line, CVP, catheter) Incision: Midline or transverse Bowel and distal duodenum mobilised to access aorta. Aneurysm neck and base dissected out and prepared for cross clamp Systemic heparinisation Cross clamp (proximal first) Longitudinal aortotomy Atherectomy Deal with back bleeding from lumbar vessels and inferior mesenteric artery Insert graft either tube or bifurcated depending upon anatomy Suture using Prolene (3/0 for proximal , distal anastomosis suture varies according to site) Clamps off: End tidal CO2 will rise owing to effects of reperfusion, at this point major risk of myocardial events. Haemostasis Closure of aneurysm sac to minimise risk of aorto-enteric fistula Closure: Loop 1 PDS or Prolene to abdominal wall Skin- surgeons preference Post operatively: ITU (Almost all) Greatest risk of complications following emergency repair Complications: Embolic- gut and foot infarcts Cardiac - owing to premorbid states, re-perfusion injury and effects of cross clamp Wound problems Later risks related to graft- infection and aorto-enteric fistula Special groups Supra renal AAA These patients will require a supra renal clamp and this carries a far higher risk of complications and risk of renal failure. Ruptured AAA Pre-operatively the management depends upon haemodynamic instability. In patients with symptoms of rupture (typical pain, haemodynamic compromise and risk factors) then ideally prompt laparotomy. In those with vague symptoms and haemodynamic stability the ideal test is CT scan to determine whether rupture has occurred or not. Most common rupture site is retroperitoneal 80%. These patients will tend to develop retroperitoneal haematoma. This can be disrupted if Bp is allowed to rise too high so aim for Bp 100mmHg. Operative details are similar to elective repair although surgery should be swift, blind rushing often makes the situation worse. Plunging vascular clamps blindly into a pool of blood at the aneurysm neck carries the risk of injury the vena cava that these patients do not withstand. Occasionally a supracoeliac clamp is needed to effect temporary control, although leaving this applied for more than 20 minutes tends to carry a dismal outcome. EVAR Increasingly patients are now being offered endovascular aortic aneurysm repair. This is undertaken by surgeons and radiologists working jointly. The morphology of the aneurysm is important and not all are suitable. Here is a typical list of those features favoring a suitable aneurysm: Long neck Straight iliac vessels Healthy groin vessels Clearly few AAA patients possess the above and compromise has to be made. The use of fenestrated grafts can allow supra renal AAA to be treated. Procedure: GA Radiology or theatre Bilateral groin incisions Common femoral artery dissected out Heparinisation Arteriotomy and insertion of guide wire Dilation of arteriotomy Insertion of EVAR Device Once in satisfactory position it is released Arteriotomy closed once check angiogram shows good position and no endoleak Complications: Endoleaks depending upon site are either Type I or 2. These may necessitate re-intervention and all EVAR patients require follow up . Details are not needed for MRCS. References A reasonable review is provided by: Sakalihasan N, Limet R, Defawe O. Abdominal aortic aneurysm. Lancet 2005 (365):1577- 1589

Answer 1214

Anterior interosseous lesions occur due to fracture, or rarely due to compression. The Gantzer muscle is an aberrant accessory of the flexor pollicis longus and is a risk factor for anterior interosseous nerve compression. Remember loss of pincer grip and normal sensation indicates an interosseous nerve lesion. Anterior interosseous nerve The anterior interosseous nerve (volar interosseous nerve) is a branch of the median nerve that supplies the deep muscles on the front of the forearm, except the ulnar half of the flexor digitorum profundus. It accompanies the anterior interosseous artery along the anterior of the interosseous membrane of the forearm, in the interval between the flexor pollicis longus and flexor digitorum profundus, supplying the whole of the former and (most commonly) the radial half of the latter, and ending below in the pronator quadratus and wrist joint. Innervation The anterior interosseous nerve classically innervates 2.5 muscles: Flexor pollicis longus Pronator quadratus The radial half of flexor digitorum profundus (the lateral two out of the four tendons). These muscles are in the deep level of the anterior compartment of the forearm.

Answer 1215

Ziehl-Neelsen stain is typically used to identify mycobacteria. They are not stained in the Gram staining process. Van Gieson and Masson trichrome are histological staining methods for identification of connective tissues. The Von Kossa technique is useful for identifying tissue mineralisation. Tuberculosis pathology Is a form of primary chronic inflammation, caused by the inability of macrophages to kill the Mycobacterium tuberculosis. The macrophages often migrate to regional lymph nodes, the lung lesion plus affected lymph nodes is referred to as a Ghon complex. This leads to the formation of a granuloma which is a collection of epithelioid histiocytes. There is the presence of caseous necrosis in the centre. The inflammatory response is mediated by a type 4 hypersensitivity reaction. In healthy individuals the disease may be contained, in the immunocompromised disseminated (miliary TB) may occur. Diagnosis Waxy membrane of mycobacteria prevents binding with normal stains. Ziehl - Neelsen staining is typically used. Culture based methods take far longer.

Answer 1216

Keratoacanthomas may reach a considerable size prior to sloughing off and scarring. Skin Diseases Skin lesions may be referred for surgical assessment, but more commonly will come via a dermatologist for definitive surgical management. Skin malignancies include basal cell carcinoma, squamous cell carcinoma and malignant melanoma. Basal Cell Carcinoma Most common form of skin cancer. Commonly occur on sun exposed sites apart from the ear. Sub types include nodular, morphoeic, superficial and pigmented. Typically slow growing with low metastatic potential. Standard surgical excision, topical chemotherapy and radiotherapy are all successful. As a minimum a diagnostic punch biopsy should be taken if treatment other than standard surgical excision is planned. Squamous Cell Carcinoma Again related to sun exposure. May arise in pre - existing solar keratoses. May metastasize if left. Immunosupression (e.g. following transplant), increases risk. Wide local excision is the treatment of choice and where a diagnostic excision biopsy has demonstrated SCC, repeat surgery to gain adequate margins may be required. Malignant Melanoma The main diagnostic features (major criteria): Change in size Change in shape Change in colour Secondary features (minor criteria) Diameter >6mm Inflammation Oozing or bleeding Altered sensation Treatment Suspicious lesions should undergo excision biopsy. The lesion should be removed completely as incision biopsy can make subsequent histopathological assessment difficult. Once the diagnosis is confirmed the pathology report should be reviewed to determine whether further re-excision of margins is required (see below): Margins of excision-Related to Breslow thickness Lesions 0-1mm thick 1cm Lesions 1-2mm thick 1- 2cm (Depending upon site and pathological features) Lesions 2-4mm thick 2-3 cm (Depending upon site and pathological features) Lesions >4 mm thick 3cm Marsden J et al. Revised UK guidelines for management of Melanoma. Br J Dermatol 2010 163:238-256. Further treatments such as sentinel lymph node mapping, isolated limb perfusion and block dissection of regional lymph node groups should be selectively applied. Kaposi Sarcoma Tumour of vascular and lymphatic endothelium. Purple cutaneous nodules. Associated with immuno supression. Classical form affects elderly males and is slow growing. Immunosupression form is much more aggressive and tends to affect those with HIV related disease. Non malignant skin disease Dermatitis Herpetiformis Chronic itchy clusters of blisters. Linked to underlying gluten enteropathy (coeliac disease). Dermatofibroma Benign lesion. Firm elevated nodules. Usually history of trauma. Lesion consists of histiocytes, blood vessels and fibrotic changes. Pyogenic granuloma Overgrowth of blood vessels. Red nodules. Usually follow trauma. May mimic amelanotic melanoma. Acanthosis nigricans Brown to black, poorly defined, velvety hyperpigmentation of the skin. Usually found in body folds such as the posterior and lateral folds of the neck, the axilla, groin, umbilicus, forehead, and other areas. The most common cause of acanthosis nigricans is insulin resistance, which leads to increased circulating insulin levels. Insulin spillover into the skin results in its abnormal increase in growth (hyperplasia of the skin). In the context of a malignant disease, acanthosis nigricans is a paraneoplastic syndrome and is then commonly referred to as acanthosis nigricans maligna. Involvement of mucous membranes is rare and suggests a coexisting malignant condition.

Answer 1217

The right lung has an oblique and horizontal fissure. The upper oblique fissure separates the inferior from the middle and upper lobes. The short horizontal fissure separates the superior and middle lobes. Lung anatomy The right lung is composed of 3 lobes divided by the oblique and transverse fissures. The left lung has two lobes divided by the oblique fissure.The apex of both lungs is approximately 4cm superior to the sterno-costal joint of the first rib. Immediately below this is a sulcus created by the subclavian artery. Peripheral contact points of the lung Base: diaphragm Costal surface: corresponds to the cavity of the chest Mediastinal surface: Contacts the mediastinal pleura. Has the cardiac impression. Above and behind this concavity is a triangular depression named the hilum, where the structures which form the root of the lung enter and leave the viscus. These structures are invested by pleura, which, below the hilum and behind the pericardial impression, forms the pulmonary ligament Right lung Above the hilum is the azygos vein; Superior to this is the groove for the superior vena cava and right innominate vein; behind this, and nearer the apex, is a furrow for the innominate artery. Behind the hilum and the attachment of the pulmonary ligament is a vertical groove for the oesophagus; In front and to the right of the lower part of the oesophageal groove is a deep concavity for the extrapericardiac portion of the inferior vena cava. The root of the right lung lies behind the superior vena cava and the right atrium, and below the azygos vein. The right main bronchus is shorter, wider and more vertical than the left main bronchus and therefore the route taken by most foreign bodies. Left lung Above the hilum is the furrow produced by the aortic arch, and then superiorly the groove accommodating the left subclavian artery; Behind the hilum and pulmonary ligament is a vertical groove produced by the descending aorta, and in front of this, near the base of the lung, is the lower part of the oesophagus. The root of the left lung passes under the aortic arch and in front of the descending aorta. Inferior borders of both lungs 6th rib in mid clavicular line 8th rib in mid axillary line 10th rib posteriorly The pleura runs two ribs lower than the corresponding lung level. Bronchopulmonary segments Segment number Right lung Left lung 1 Apical Apical 2 Posterior Posterior 3 Anterior Anterior 4 Lateral Superior lingular 5 Medial Inferior lingular 6 Superior (apical) Superior (apical) 7 Medial basal Medial basal 8 Anterior basal Anterior basal 9 Lateral basal Lateral basal 10 Posterior basal Posterior basal

Answer 1218

The inferior thyroid artery originates from the thyrocervical trunk. This is a branch of the subclavian artery. Thyroid gland Right and left lobes connected by isthmus Surrounded by sheath from pretracheal layer of deep fascia Apex: Lamina of thyroid cartilage Base: 4th-5th tracheal ring Pyramidal lobe: from isthmus May be attached to foramen caecum at the base of the tongue Relations Anteromedially Sternothyroid Superior belly of omohyoid Sternohyoid Anterior aspect of sternocleidomastoid Posterolaterally Carotid sheath Medially Larynx Trachea Pharynx Oesophagus Cricothyroid muscle External laryngeal nerve (near superior thyroid artery) Recurrent laryngeal nerve (near inferior thyroid artery) Posterior Parathyroid glands Anastomosis of superior and inferior thyroid arteries Isthmus Anteriorly: Sternothyroids, sternohyoids, anterior jugular veins Posteriorly: 2nd, 3rd, 4th tracheal rings (attached via Ligament of Berry) Blood Supply Arterial Superior thyroid artery (1st branch of external carotid) Inferior thyroid artery (from thyrocervical trunk) Thyroidea ima (in 10% of population -from brachiocephalic artery or aorta) Venous Superior and middle thyroid veins - into the IJV Inferior thyroid vein - into the brachiocephalic veins

Answer 1219

The tubercle bacilli has a waxy outer membrane that renders it more resistant to sterilisation and cleaning methods. Whilst 0.1% sodium hypochlorite will destroy many microbes it is less reliable in destroying tubercle bacilli. Hot air ovens provide less reliable pathogen destruction than autoclaving, but may be indicated in situations where the equipment is sensitive to the autoclaving process. From the list of options above, autoclaving will most reliably destroy tubercle bacilli. Sterilisation Surgical equipment has to be cleaned and sterilised prior to use. The extent to which these processes will be required varies according to the type of equipment and the purpose for which it will be used. In general, the three processes are relevant; cleaning, disinfection and sterilisation. Cleaning refers to removal of physical debris. Disinfection refers to reduction in numbers of viable organisms. Sterilisation is removal of all organisms and spores. Methods Method Details Indication Autoclaving Air removed and high pressure steam used (usually 134 oC for 3 minutes) Most reusable surgical equipment, must be physically cleaned prior to autoclaving, unsuitable for fragile items Glutaraldehyde solution (2%) Colourless oily liquid, directly cytocidal and virucidal even at low temperatures Specifically used for endoscopes and some laparoscopic items, staff can rapidly develop allergy to this substance which has limited its more widespread use Ethylene oxide 3% mixture of gas with carbon dioxide used Used for packaged materials that cannot be heated, the gas is explosive and environmentally toxic, it is used mainly in the industrial setting Gamma irradiation Gamma rays emitted from radioactive substance such as cobalt 60 or caesium 137 Suitable for batch treatment of relatively thermostable items, typically an industrial process

Answer 1220

Hepatocellular adenomas in males have a greater risk of malignant transformation and resection should be considered. Hepatocellular adenoma 90% develop in women in their third to fifth decade Linked to use of oral contraceptive pill Lesions are usually solitary They are usually sharply demarcated from normal liver although they usually lack a fibrous capsule On ultrasound the appearances are of mixed echoity and heterogeneous texture. On CT most lesions are hypodense when imaged prior to administration of IV contrast agents In patients with haemorrhage or symptoms removal of the adenoma may be required Asymptomatic adenomas >5cm are usually excised Adenomas in males are likely to be smaller but have a greater risk of malignant transformation - Risk of rupture is greater in lesions larger than 5cm and those which are exophytic. Mortality rates from spontaneous rupture are 5-10%.

Answer 1221

A large hyperechoic lesion in the presence of normal AFP is likely to be a haemangioma. An HCC of equivalent size will almost always result in rise in AFP. Benign liver lesions Benign liver lesions Haemangioma Most common benign tumours of mesenchymal origin Incidence in autopsy series is 8% Cavernous haemangiomas may be enormous Clinically they are reddish purple hypervascular lesions Lesions are normally separated from normal liver by ring of fibrous tissue On ultrasound they are typically hyperechoic Liver cell adenoma 90% develop in women in their third to fifth decade Linked to use of oral contraceptive pill Lesions are usually solitary They are usually sharply demarcated from normal liver although they usually lack a fibrous capsule On ultrasound the appearances are of mixed echoity and heterogeneous texture. On CT most lesions are hypodense when imaged prior to administration of IV contrast agents In patients with haemorrhage or symptoms removal of the adenoma may be required Mesenchymal hamartomas Congential and benign, usually present in infants. May compress normal liver Liver abscess Biliary sepsis is a major predisposing factor Structures drained by the portal venous system form the second largest source Common symptoms include fever, right upper quadrant pain. Jaundice may be seen in 50% Ultrasound will usually show a fluid filled cavity, hyperechoic walls may be seen in chronic abscesses Amoebic abscess Liver abscess is the most common extra intestinal manifestation of amoebiasis Between 75 and 90% lesions occur in the right lobe Presenting complaints typically include fever and right upper quadrant pain Ultrasonography will usually show a fluid filled structure with poorly defined boundaries Aspiration yield sterile odourless fluid which has an anchovy paste consistency Treatment is with metronidazole Hyatid cysts Seen in cases of Echinococcus infection Typically an intense fibrotic reaction occurs around sites of infection The cyst has no epithelial lining Cysts are commonly unilocular and may grow to 20cm in size. The cyst wall is thick and has an external laminated hilar membrane and an internal enucleated germinal layer Typically presents with malaise and right upper quadrant pain. Secondary bacterial infection occurs in 10%. Liver function tests are usually abnormal and eosinophilia is present in 33% cases Ultrasound may show septa and hyatid sand or daughter cysts. Percutaneous aspiration was previously contra indicated, it is now incorporated into some treatment regimens Treatment is by sterilisation of the cyst with mebendazole and may be followed by surgical resection. Hypertonic swabs are packed around the cysts during surgery Polycystic liver disease Usually occurs in association with polycystic kidney disease Autosomal dominant disorder Symptoms may occur as a result of capsular stretch Cystadenoma Rare lesions with malignant potential Usually solitary multiloculated lesions Liver function tests usually normal Ultrasonography typically shows a large anechoic, fluid filled area with irregular margins. Internal echos may result from septa Surgical resection is indicated in all cases

Answer 1222

T2 lesions in a young fit patient are best managed surgically. Up to 25 % patients may develop perioperative complications. However, palliative treatments and intravesical chemotherapy (which does NOT include cisplatin) are not used curatively in this situation. Bladder cancer Bladder cancer is the second most common urological cancer. It most commonly affects males aged between 50 and 80 years of age. Those who are current, or previous (within 20 years), smokers have a 2-5 fold increased risk of the disease. Exposure to hydrocarbons such as 2-Naphthylamine increases the risk. Although rare in the UK, chronic bladder inflammation arising from Schistosomiasis infection remains a common cause of squamous cell carcinomas, in those countries where the disease is endemic. Benign tumours Benign tumours of the bladder including inverted urothelial papilloma and nephrogenic adenoma are uncommon. Bladder malignancies Transitional cell carcinoma (>90% of cases) Squamous cell carcinoma ( 1-7% -except in regions affected by schistosomiasis) Adenocarcinoma (2%) Transitional cell carcinomas may arise as solitary lesions, or may be multifocal, owing to the effect of 'field change' within the urothelium. Up to 70% of TCC's will have a papillary growth pattern. These tumours are usually superficial in location and accordingly have a better prognosis. The remaining tumours show either mixed papillary and solid growth or pure solid growths. These tumours are typically more prone to local invasion and may be of higher grade, the prognosis is therefore worse. Those with T3 disease or worse have a 30% (or higher) risk of regional or distant lymph node metastasis. TNM Staging Stage Description T0 No evidence of tumour Ta Non invasive papillary carcinoma T1 Tumour invades sub epithelial connective tissue T2a Tumor invades superficial muscularis propria (inner half) T2b Tumor invades deep muscularis propria (outer half) T3 Tumour extends to perivesical fat T4 Tumor invades any of the following: prostatic stroma, seminal vesicles, uterus, vagina T4a Invasion of uterus, prostate or bowel T4b Invasion of pelvic sidewall or abdominal wall N0 No nodal disease N1 Single regional lymph node metastasis in the true pelvis (hypogastric, obturator, external iliac, or presacral lymph node) N2 Multiple regional lymph node metastasis in the true pelvis (hypogastric, obturator, external iliac, or presacral lymph node metastasis) N3 Lymph node metastasis to the common iliac lymph nodes M0 No distant metastasis M1 Distant disease Presentation Most patients (85%) will present with painless, macroscopic haematuria. In those patients with incidental microscopic haematuria, up to 10% of females aged over 50 will be found to have a malignancy (once infection excluded). Staging Most will undergo a cystoscopy and biopsies or TURBT, this provides histological diagnosis and information relating to depth of invasion. Locoregional spread is best determined using pelvic MRI and distant disease CT scanning. Nodes of uncertain significance may be investigated using PET CT. Treatment Those with superficial lesions may be managed using TURBT in isolation. Those with recurrences or higher grade/ risk on histology may be offered intravesical chemotherapy. Those with T2 disease are usually offered either surgery (radical cystectomy and ileal conduit) or radical radiotherapy. Prognosis T1 90% T2 60% T3 35% T4a 10-25% Any T, N1-N2 30%

Answer 1223

Merkel cell tumours are rare cutaneous tumours. Histologically they consist of sheets and nodules of hyperchromatic epithelial cells, with high rates of mitosis and apoptosis. As such they are relatively easy to distinguish from pyogenic granuloma which has no features of malignancy and would not show lymphovascular invasion. Merkel cell tumours of the skin Rare but aggressive tumour. Develops from intra epidermal Merkel cells. Usually presents on elderly, sun damaged skin. The periorbital area is the commonest site. Histologically these tumours appear within the dermis and subcutis. The lesions consist of sheets and nodules of small hyperchromatic epithelial cells with high rates of mitosis and apoptosis. Lymphovascular invasion is commonly seen. Pre-existing infection with Merkel Cell Polyomavirus is seen in 80% cases. Treatment Surgical excision is first line. Margins of 1cm are required. Lesions >10mm in diameter should undergo sentinel lymph node biopsy. Adjuvant radiotherapy is often given to reduce the risk of local recurrence. Prognosis With lymph node metastasis 5 year survival is 50% or less. Small lesions without nodal spread are usually associated with a 5 year survival of 80%.

Answer 1224

Mnemonic for the Inferior vena cava tributaries: I Like To Rise So High: Iliacs Lumbar Testicular Renal Suprarenal Hepatic vein The lack of valves in the IVC is important clinically when it is cannulated during cardiopulmonary bypass, using separate SVC and IVC catheters, such as when the right atrium is to be opened. Note that there is a non functional valve between the right atrium and inferior vena cava. Inferior vena cava Origin L5 Path Left and right common iliac veins merge to form the IVC. Passes right of midline Paired segmental lumbar veins drain into the IVC throughout its length The right gonadal vein empties directly into the cava and the left gonadal vein generally empties into the left renal vein. The next major veins are the renal veins and the hepatic veins Pierces the central tendon of diaphragm at T8 Right atrium Relations Anteriorly Small bowel, first and third part of duodenum, head of pancreas, liver and bile duct, right common iliac artery, right gonadal artery Posteriorly Right renal artery, right psoas, right sympathetic chain, coeliac ganglion Levels Level Vein T8 Hepatic vein, inferior phrenic vein, pierces diaphragm L1 Right suprarenal vein, renal vein L2 Gonadal vein L1-5 Lumbar veins L5 Common iliac vein, formation of IVC

Answer 1225

Rectal cancers with threatened resection margins are managed with radiotherapy and chemotherapy initially. This is not the case with colonic cancers which are usually primarily resected. T4 rectal cancers are managed with long course chemoradiotherapy. A dramatic response is not uncommon. To embark on attempted resection at this stage is to court failure. Colorectal cancer treatment Patients diagnosed as having colorectal cancer should be completely staged using CT of the chest/ abdomen and pelvis. Their entire colon should have been evaluated with colonoscopy or CT colonography. Patients whose tumours lie below the peritoneal reflection should have their mesorectum evaluated with MRI. Once their staging is complete patients should be discussed within a dedicated colorectal MDT meeting and a treatment plan formulated. Treatment of colonic cancer Cancer of the colon is nearly always treated with surgery. Stents, surgical bypass and diversion stomas may all be used as palliative adjuncts. Resectional surgery is the only option for cure in patients with colon cancer. The procedure is tailored to the patient and the tumour location. The lymphatic drainage of the colon follows the arterial supply and therefore most resections are tailored around the resection of particular lymphatic chains (e.g. ileo-colic pedicle for right sided tumours). Some patients may have confounding factors that will govern the choice of procedure, for example a tumour in a patient from a HNPCC family may be better served with a panproctocolectomy rather than segmental resection. Following resection the decision has to be made regarding restoration of continuity. For an anastomosis to heal the key technical factors include; adequate blood supply, mucosal apposition and no tissue tension. Surrounding sepsis, unstable patients and inexperienced surgeons may compromise these key principles and in such circumstances it may be safer to construct an end stoma rather than attempting an anastomosis. When a colonic cancer presents with an obstructing lesion; the options are to either stent it or resect. In modern practice it is unusual to simply defunction a colonic tumour with a proximal loop stoma. This differs from the situation in the rectum (see below). Following resection patients with risk factors for disease recurrence are usually offered chemotherapy, a combination of 5FU and oxaliplatin is common. Rectal cancer The management of rectal cancer is slightly different to that of colonic cancer. This reflects the rectum's anatomical location and the challenges posed as a result. Tumours located in the rectum can be surgically resected with either an anterior resection or an abdomino - perineal resection. The technical aspects governing the choice between these two procedures can be complex to appreciate and the main point to appreciate for the MRCS is that involvement of the sphincter complex or very low tumours require APER. In the rectum a 2cm distal clearance margin is required and this may also impact on the procedure chosen. In addition to excision of the rectal tube an integral part of the procedure is a meticulous dissection of the mesorectal fat and lymph nodes (total mesorectal excision/ TME). In rectal cancer surgery invovlement of the cirumferential resection margin carries a high risk of disease recurrence. Because the rectum is an extraperitoneal structure (until you remove it that is!) it is possible to irradiate it, something which cannot be offered for colonic tumours. This has a major impact in rectal cancer treatment and many patients will be offered neoadjuvent radiotherapy (both long and short course) prior to resectional surgery. Patients with T1, 2 and 3 /N0 disease on imaging do not require irradiation and should proceed straight to surgery. Patients with T4 disease will typically have long course chemo radiotherapy. Patients presenting with large bowel obstruction from rectal cancer should not undergo resectional surgery without staging as primary treatment (very different from colonic cancer). This is because rectal surgery is more technically demanding, the anastomotic leak rate is higher and the danger of a positive resection margin in an unstaged patient is high. Therefore patients with obstructing rectal cancer should have a defunctioning loop colostomy. Summary of procedures The operations for cancer are segmental resections based on blood supply and lymphatic drainage. These commonly performed procedures are core knowledge for the MRCS and should be understood. Site of cancer Type of resection Anastomosis Risk of leak Right colon Right hemicolectomy Ileo-colic Low <5% Transverse Extended right hemicolectomy Ileo-colic Low <5% Splenic flexure Extended right hemicolectomy Ileo-colic Low <5% Splenic flexure Left hemicolectomy Colo-colon 2-5% Left colon Left hemicolectomy Colo-colon 2-5% Sigmoid colon High anterior resection Colo-rectal 5% Upper rectum Anterior resection (TME) Colo-rectal 5% Low rectum Anterior resection (Low TME) Colo-rectal (+/- Defunctioning stoma) 10% Anal verge Abdomino-perineal excision of colon and rectum None n/a In the emergency setting, where the bowel has perforated, the risk of an anastomotic breakdown is much greater, particularly when the anastomosis is colon-colon. In this situation, an end colostomy is often safer and can be reversed later. When resection of the sigmoid colon is performed and an end colostomy is fashioned the operation is referred to as a Hartmans procedure. Whilst left sided resections are more risky, ileo-colic anastomoses are relatively safe even in the emergency setting and do not need to be defunctioned. References A review of the diagnosis and management of colorectal cancer and a summary of the UK National Institute of Clinical Excellence guidelines is provided in: NICE Guideline NG151. Last updated in 2020.

Answer 1226

A- The anterior compartment contains: Tibialis anterior Extensor digitorum longus Peroneus tertius Extensor hallucis longus Anterior tibial artery All the muscles are innervated by the deep peroneal nerve. Lower limb- Muscular compartments Anterior compartment Muscle Nerve Action Tibialis anterior Deep peroneal nerve Dorsiflexes ankle joint, inverts foot Extensor digitorum longus Deep peroneal nerve Extends lateral four toes, dorsiflexes ankle joint Peroneus tertius Deep peroneal nerve Dorsiflexes ankle, everts foot Extensor hallucis longus Deep peroneal nerve Dorsiflexes ankle joint, extends big toe Peroneal compartment Muscle Nerve Action Peroneus longus Superficial peroneal nerve Everts foot, assists in plantar flexion Peroneus brevis Superficial peroneal nerve Plantar flexes the ankle joint Superficial posterior compartment Nerve Action Gastrocnemius Tibial nerve Plantar flexes the foot, may also flex the knee Soleus Tibial nerve Plantar flexor Deep posterior compartment Muscle Nerve Action Flexor digitorum longus Tibial Flexes the lateral four toes Flexor hallucis longus Tibial Flexes the great toe Tibialis posterior Tibial Plantar flexor, inverts the foot

Answer 1227

The pancreatic artery is a branch of the splenic artery. Coeliac axis The coeliac axis has three main branches. Left gastric Hepatic: branches-Right Gastric, Gastroduodenal, Superior Pancreaticoduodenal, Cystic (occasionally). Splenic: branches- Pancreatic, Short Gastric, Left Gastroepiploic It occasionally gives off one of the inferior phrenic arteries. Relations Anteriorly Lesser omentum Right Right coeliac ganglion and caudate process of liver Left Left coeliac ganglion and gastric cardia Inferiorly Upper border of pancreas and renal vein

Answer 1228

Ameloblastomas are rare tumours of the odontogenic epithelium. They are slow growing and expand with a rim of periosteum that surrounds them. It is the palpation and disruption of this layer that gives rise to the crepitus. Diseases of nose and sinuses Benign Tumours Simple papillomas may be an incidental finding or present with obstructive symptoms. Excision under general anaesthesia is sufficient management. Transitional cell papillomas may be more extensive and produce obstructive symptoms. Erosion of local structures is a recognised complication. These lesions may rarely undergo malignant transformation and therefore careful and complete excision is required, some cases may require partial or total maxillectomy. Pleomorphic adenomas of the maxillary sinuses are reported but are extremely rare, their symptoms typically include nasal obstruction and pain if the sinus is obstructed. Treatment is by complete surgical excision, the diagnosis is not infrequently made post operatively. Benign osteomas may develop in the paranasal sinuses, the frontal sinus is the most frequent location of such lesions. Symptoms include; pain, rhinorrhoea and anosmia. Most osteomas may be observed if asymptomatic, sphenoid osteomas should be resected soon after diagnosis as enlargement may compromise visual fields. Many sinus osteomas can now be resected endoscopically, complete surgical resection is required. Nasal polyps are benign lesions of the ethmoid sinus mucosa. Many patients may also have asthma, cystic fibrosis and a sensitivity to aspirin. Symptoms include watery rhinorrhoea, infection and anosmia. The polyps are usually a semi transparent grey mass. They are rare in childhood. Treatment is either with systemic steroids or surgical resection. The latter should be combined with antral washout. Low dose, nasal, steroid drops may reduce the risk of recurrence. Malignant disease Malignancies encountered in the nose and paranasal sinuses include; adenoid cystic carcinoma, squamous cell carcinoma and adenocarcinoma. Adenocarcinoma of the paranasal sinuses and nasopharynx is strongly linked to exposure to hard wood dust (after >10 years exposure). Adenoid cystic carcinoma usually originate in the smaller salivary glands. The majority of cancers (50%) arise from the lateral nasal wall, a smaller number (33%) arise from the maxillary antrum, ethmoid and sphenoid cancers comprise only 7%. Signs of malignancy on clinical examination include loose teeth, cranial nerve palsies and lymphadenopathy. Nasopharyngeal cancers are most common in individuals presenting from China and Asia and are linked to viral infection with Epstein Barr Virus. Radiotherapy and chemotherapy are the most commonly used modalities. Maxillary sinusitis Common symptoms include post nasal discharge, pain, headache and toothache. Imaging may show a fluid level in the antrum. Common organisms include Haemophilus influenzae or Streptococcus pneumoniae. Treatment with antral lavage may facilitate diagnosis and relieve symptoms. Antimicrobial therapy has to be continued for long periods. Antrostomy may be needed. Frontoethmoidal sinusitis Usually presents with frontal headache, nasal obstruction and altered sense of smell. Inflammation may progress to involve periorbital tissues. Ocular symptoms may occur and secondary CNS involvement brought about by infection entering via emissary veins. CT scanning is the imaging modality of choice. Early cases may be managed with antibiotics. More severe cases usually require surgical drainage.

Answer 1229

The axon loses its excitability once the process is established. Wallerian degeneration - Is the process that occurs when a nerve is cut or crushed. - It occurs when the part of the axon separated from the neuron's cell nucleus degenerates. - It usually begins 24 hours following neuronal injury and the distal axon remains excitable up until this time. - The degeneration of the axon is followed by breakdown of the myelin sheath, a process that occurs by infiltration of the site with macrophages. - Eventually regeneration of the nerve may occur although recovery will depend on the extent and manner of injury

Answer 1230

The features described are those of worsening graft function and acute rejection. The fact that there is a 10 day delay goes against hyperacute rejection. Cold ischaemic times are a major factor for delayed graft function. However, even 26 hours is not incompatible with graft survival. Complications following renal transplant Renal transplantation is widely practised. The commonest technical related complications are related to the ureteric anastomosis. The warm ischaemic time is also of considerable importance and graft survival is directly related to this. Long warm ischaemic times increase the risk of acute tubular necrosis which may occur in all types of renal transplanation and provided other insults are minimised, will usually recover. Organ rejection may occur at any phase following the transplantation process. Immunological complications Types of organ rejection Hyperacute. This occurs immediately through presence of pre formed antibody (such as ABO incompatibility). Acute. Occurs during the first 6 months and is usually T cell mediated. Usually tissue infiltrates and vascular lesions. Chronic. Occurs after the first 6 months. Vascular changes predominate. Hyperacute Renal transplants are most susceptible to this process. Risk factors include major HLA mismatch and ABO incompatibility. The rejection occurs almost immediately and the macroscopic features may become manifest following completion of the vascular anastomosis and removal of clamps. The kidney becomes mottled, dusky and the vessels will thrombose. The only treatment is removal of the graft, if left in situ it will result in abscess formation. Acute All organs may undergo acute rejection. Mononuclear cell infiltrates predominate. All types of transplanted organ are susceptible and it may occur in up to 50% cases. Most cases can be managed medically. Chronic Again all transplants with HLA mismatch may suffer this fate. Previous acute rejections and other immunosensitising events all increase the risk. Vascular changes are most prominent with myointimal proliferation leading to organ ischaemia. Organ specific changes are also seen such as loss of acinar cells in pancreas transplants and rapidly progressive coronary artery disease in cardiac transplants. Technical complications Complication Presenting features Treatment Renal artery thrombosis Sudden complete loss of urine output Immediate surgery may salvage the graft, delays beyond 30 minutes are associated with a high rate of graft loss Renal artery stenosis Uncontrolled hypertension, allograft dysfunction and oedema Angioplasty is the treatment of choice Renal vein thrombosis Pain and swelling over the graft site, haematuria and oliguria The graft is usually lost Urine leaks Diminished urine output, rising creatinine, fever and abdominal pain USS shows perigraft collection, necrosis of ureter tip is the commonest cause and the anastomosis may need revision Lymphocele Common complication (occurs in 15%), may present as a mass, if large may compress ureter May be drained with percutaneous technique and sclerotherapy, or intraperitoneal drainage

Answer 1231

Most venous ulcers are managed with compression bandages. Skin grafting is sometimes used. However, ulcer excision is not standard practice and closure would be impossible. Chronic venous insufficiency and varicose veins Wide spectrum of disease ranging from minor cosmetic problem through to ulceration and disability. It is commoner in women than men and is worse during pregnancy. Varicose veins are best considered as being a saccular dilation of veins (WHO). Chronic venous insufficiency is a series of tissue changes which occur in relation to pooling of blood in the extremities with associated venous hypertension occurring as a result of incompetent deep vein valves. The veins of the lower limb consist of an interconnected network of superficial and deep venous systems. Varices occur because of localised weakness in the vein wall resulting in dilatation and reflux of blood due to non union of valve cusps. Histologically, the typical changes include fibrous scar tissue dividing smooth muscle within media in the vessel wall. Tissue damage in chronic venous insufficiency occurs because of perivascular cytokine leakage resulting in localised tissue damage coupled with impaired lymphatic flow. Diagnosis Typical symptoms of varicose veins include: Cosmetic appearance Aching Ankle swelling that worsens as the day progresses Episodic thrombophlebitis Bleeding Itching Symptoms of chronic venous insufficiency include: Dependant leg pain Prominent leg swelling Oedema extending beyond the ankle Venous stasis ulcers The typical venous stasis ulcer is: Located above the medial malleolus Indolent appearance with basal granulation tissue Variable degree of scarring Non ischaemic edges Haemosiderin deposition in the gaiter area (and also lipodermatosclerosis). Differential diagnosis Lower limb arterial disease Marjolins ulcer Claudication Spinal stenosis Swelling due to medical causes e.g. CCF. Exclusion of these differentials is by means of physical examination and ankle brachial pressure index measurement. Examination Assess for dilated short saphenous vein (popliteal fossa) and palpate for saphena varix medial to the femoral artery Brodie-Trendelenburg test: to assess level of incompetence Perthes' walking test: assess if deep venous system competent Investigation Doppler exam: if incompetent a biphasic signal due to retrograde flow is detected Duplex scanning: to ensure patent deep venous system (do if DVT or trauma) All patients should have a Doppler assessment to assess for venous reflux and should be classified as having uncomplicated varicose veins or varicose veins with associated chronic venous insufficiency. In the history establishing a previous thrombotic event (DVT/ lower limb fracture) is important and patients with such a history and all who have evidence of chronic venous insufficiency should have a duplex scan performed. Owing to litigation patients with saphenopopliteal incompetence should have a duplex scan performed and the site marked by scan on the day of surgery. Treatment Indications for surgery: Cosmetic: majority Lipodermatosclerosis causing venous ulceration Recurrent superficial thrombophlebitis Bleeding from ruptured varix Condition Therapy Minor varicose veins - no complications Reassure/ cosmetic therapy Symptomatic uncomplicated varicose veins In those without deep venous insufficiency options include; endothermal ablation, foam sclerotherapy, saphenofemoral / popliteal disconnection, stripping and avulsions, compression stockings Varicose veins with skin changes Therapy as above (if compression minimum is formal class I stockings) Chronic venous insufficiency or ulcers Class 2-3 compression stockings (ensure no arterial disease). Application of formal compression stockings (usually class II/III). In patients who have suffered ulceration, compression stockings should be worn long term. Where ulceration is present and established saphenofemoral reflux exists this should be addressed surgically for durable relief of symptoms, either at the outset or following ulcer healing. Injection sclerotherapy (5% Ethanolamine oleate), foam is increasingly popular, though transient blindness has been reported. Endo venous laser therapy is another minimally invasive option Sapheno-femoral or sapheno-popliteal ligation, in the case of the LSV; stripping and multiple phlebectomies Current best practice guidance In the United Kingdom the National Institute of Clinical Excellence guidance on varicose veins suggests that for patients with symptomatic varicose veins the first line procedure of choice should be endothermal ablation (see reference for more information). Where this is unavailable or unsuitable then foam sclerotherapy should be the second line option. Surgery is currently the third line treatment option. Trendelenburg procedure (sapheno-femoral junction ligation) Head tilt 15 degrees and legs abducted Oblique incision 1cm medial from artery Tributaries ligated (Superficial circumflex iliac vein, Superficial inferior epigastric vein, Superficial and deep external pudendal vein) SF junction double ligated Saphenous vein stripped to level of knee/upper calf. NB increased risk of saphenous neuralgia if stripped more distally References Marsden G et al. Diagnosis of management of varicose veins in the the legs: summary of NICE guidance. BMJ 2013 (347): 30-31.

Answer 1232

C3,4,5 Keeps the diaphragm alive! They both lie anterior to the hilum of the lung. The phrenic nerves have both motor and sensory functions. For this reason sub diaphragmatic pathology may cause referred pain to the shoulder. Phrenic nerve Origin C3,4,5 Supplies Diaphragm, sensation central diaphragm and pericardium Path The phrenic nerve passes with the internal jugular vein across scalenus anterior. It passes superficial to prevertebral fascia of deep cervical fascia. Left: crosses anterior to the 1st part of the subclavian artery. Right: Anterior to scalenus anterior and crosses anterior to the 2nd part of the subclavian artery. On both sides, the phrenic nerve runs posterior to the subclavian vein and posterior to the internal thoracic artery as it enters the thorax. Right phrenic nerve In the superior mediastinum: anterior to right vagus and laterally to superior vena cava Middle mediastinum: right of pericardium It passes over the right atrium to exit the diaphragm at T8 Left phrenic nerve Passes lateral to the left subclavian artery, aortic arch and left ventricle Passes anterior to the root of the lung Pierces the diaphragm alone

Answer 1233

Peaked T waves are the first and most common finding in hyperkalaemia. ECG features in hyperkalaemia Peaking of T waves (occurs first) Loss of P waves Broad QRS complexes Ventricullar fibrillation

Answer 1234

Sjogren's is associated with autoimmune disorders. Mikulicz's is similar but there is no sicca or arthritis. Neck lumps The table below gives characteristic exam question features for conditions causing neck lumps: Reactive lymphadenopathy By far the most common cause of neck swellings. There may be a history of local infection or a generalised viral illness Lymphoma Rubbery, painless lymphadenopathy The phenomenon of pain whilst drinking alcohol is very uncommon There may be associated night sweats and splenomegaly Thyroid swelling May be hypo-, eu- or hyperthyroid symptomatically Moves upwards on swallowing Thyroglossal cyst More common in patients < 20 years old Usually midline, between the isthmus of the thyroid and the hyoid bone Moves upwards with protrusion of the tongue May be painful if infected Pharyngeal pouch More common in older men Represents a posteromedial herniation between thyropharyngeus and cricopharyngeus muscles Usually not seen, but if large then a midline lump in the neck that gurgles on palpation Typical symptoms are dysphagia, regurgitation, aspiration and chronic cough Cystic hygroma A congenital lymphatic lesion (lymphangioma) typically found in the neck, classically on the left side Most are evident at birth, around 90% present before 2 years of age Branchial cyst An oval, mobile cystic mass that develops between the sternocleidomastoid muscle and the pharynx Develop due to failure of obliteration of the second branchial cleft in embryonic development Usually present in early adulthood Cervical rib More common in adult females Around 10% develop thoracic outlet syndrome Carotid aneurysm Pulsatile lateral neck mass which doesn't move on swallowing

Answer 1235

The chorda tympani branches inside the facial canal and will therefore be unaffected by this most unfortunate event! The corneal reflex is mediated by the opthalmic branch of the trigeminal nerve sensing the stimulus on the cornea, lid or conjunctiva; the facial nerve initiates the motor response of the reflex. Facial nerve The facial nerve is the main nerve supplying the structures of the second embryonic branchial arch. It is predominantly an efferent nerve to the muscles of facial expression, digastric muscle and also to many glandular structures. It contains a few afferent fibres which originate in the cells of its genicular ganglion and are concerned with taste. Supply - 'face, ear, taste, tear' Face: muscles of facial expression Ear: nerve to stapedius Taste: supplies anterior two-thirds of tongue Tear: parasympathetic fibres to lacrimal glands, also salivary glands Path Subarachnoid path Origin: motor- pons, sensory- nervus intermedius Pass through the petrous temporal bone into the internal auditory meatus with the vestibulocochlear nerve. Here they combine to become the facial nerve. Facial canal path The canal passes superior to the vestibule of the inner ear At the medial aspect of the middle ear, it becomes wider and contains the geniculate ganglion. - 3 branches: 1. greater petrosal nerve 2. nerve to stapedius 3. chorda tympani Stylomastoid foramen Passes through the stylomastoid foramen (tympanic cavity anterior and mastoid antrum posteriorly) Posterior auricular nerve and branch to posterior belly of digastric and stylohyoid muscle Face Enters parotid gland and divides into 5 branches: Temporal branch Zygomatic branch Buccal branch Marginal mandibular branch Cervical branch

Answer 1236

Renin hydrolyses angiotensinogen to form angiotensin I. Renin Renin is secreted by juxtaglomerular cells and hydrolyses angiotensinogen to produce angiotensin I Factors stimulating renin secretion Hypotension causing reduced renal perfusion Hyponatraemia Sympathetic nerve stimulation Catecholamines Erect posture Factors reducing renin secretion Drugs: beta-blockers, NSAIDs

Answer 1237

If you answered the question incorrectly, check you have read it properly as it asks for the least likely cause. Note the question asks for the least likely cause. There are many reasons why an alcoholic may develop neurology. However, an extra dural bleed would not typically present such a long latent period. Head injury Patients who suffer head injuries should be managed according to ATLS principles and extra cranial injuries should be managed alongside cranial trauma. Inadequate cardiac output will compromise CNS perfusion irrespective of the nature of the cranial injury. Types of traumatic brain injury Extradural haematoma Bleeding into the space between the dura mater and the skull. Often results from acceleration-deceleration trauma or a blow to the side of the head. The majority of extradural haematomas occur in the temporal region where skull fractures cause a rupture of the middle meningeal artery. Features Raised intracranial pressure Some patients may exhibit a lucid interval Subdural haematoma Bleeding into the outermost meningeal layer. Most commonly occur around the frontal and parietal lobes. May be either acute or chronic. Risk factors include old age and alcoholism. Slower onset of symptoms than a extradural haematoma. Subarachnoid haemorrhage Usually occurs spontaneously in the context of a ruptured cerebral aneurysm, but may be seen in association with other injuries when a patient has sustained a traumatic brain injury. Pathophysiology Primary brain injury may be focal (contusion/ haematoma) or diffuse (diffuse axonal injury) Diffuse axonal injury occurs as a result of mechanical shearing following deceleration, causing disruption and tearing of axons Intra-cranial haematomas can be extradural, subdural or intracerebral, while contusions may occur adjacent to (coup) or contralateral (contre-coup) to the side of impact Secondary brain injury occurs when cerebral oedema, ischaemia, infection, tonsillar or tentorial herniation exacerbates the original injury. The normal cerebral auto regulatory processes are disrupted following trauma rendering the brain more susceptible to blood flow changes and hypoxia The Cushings reflex (hypertension and bradycardia) often occurs late and is usually a pre terminal event Management Where there is life threatening rising ICP such as in extra dural haematoma and whilst theatre is prepared or transfer arranged use of IV mannitol/ frusemide may be required. Diffuse cerebral oedema may require decompressive craniotomy Exploratory Burr Holes have little management in modern practice except where scanning may be unavailable and to thus facilitate creation of formal craniotomy flap Depressed skull fractures that are open require formal surgical reduction and debridement, closed injuries may be managed non operatively if there is minimal displacement. ICP monitoring is appropriate in those who have GCS 3-8 and normal CT scan. ICP monitoring is mandatory in those who have GCS 3-8 and abnormal CT scan. Hyponatraemia is most likely to be due to syndrome of inappropriate ADH secretion. Minimum of cerebral perfusion pressure of 70mmHg in adults. Minimum cerebral perfusion pressure of between 40 and 70 mmHg in children. Interpretation of pupillary findings in head injuries Pupil size Light response Interpretation Unilaterally dilated Sluggish or fixed 3rd nerve compression secondary to tentorial herniation Bilaterally dilated Sluggish or fixed Poor CNS perfusion Bilateral 3rd nerve palsy Unilaterally dilated or equal Cross reactive (Marcus - Gunn) Optic nerve injury Bilaterally constricted May be difficult to assess Opiates Pontine lesions Metabolic encephalopathy Unilaterally constricted Preserved Sympathetic pathway disruption

Answer 1238

Signet ring cells are features of poorly differentiated gastric cancer associated with a increased risk of metastatic disease. Gastric cancer Overview There are 700,000 new cases of gastric cancer worldwide each year. It is most common in Japan and less common in western countries. It is more common in men and incidence rises with increasing age. The exact cause of many sporadic cancer is not known, however, familial cases do occur in HNPCC families. In addition, smoking and smoked or preserved foods increase the risk. Japanese migrants retain their increased risk (decreased in subsequent generations). The distribution of the disease in western countries is changing towards a more proximal location (perhaps due to rising obesity). Pathology There is some evidence of support a stepwise progression of the disease through intestinal metaplasia progressing to atrophic gastritis and subsequent dysplasia, through to cancer. The favoured staging system is TNM. The risk of lymph node involvement is related to size and depth of invasion; early cancers confined to submucosa have a 20% incidence of lymph node metastasis. Tumours of the gastro-oesophageal junction are classified as below: Type 1 True oesophageal cancers and may be associated with Barrett's oesophagus. Type 2 Carcinoma of the cardia, arising from cardiac type epithelium or short segments with intestinal metaplasia at the oesophagogastric junction. Type 3 Sub cardial cancers that spread across the junction. Involve similar nodal stations to gastric cancer. Groups for close endoscopic monitoring Intestinal metaplasia of columnar type Atrophic gastritis Low to medium grade dysplasia Patients who have previously undergone resections for benign peptic ulcer disease (except highly selective vagotomy). Referral to endoscopy Patients of any age with dyspepsia and any of the following Patients without dyspepsia Worsening dyspepsia Chronic gastrointestinal bleeding Dysphagia Barretts oesophagus Dysphagia Unexplained abdominal pain or weight loss Intestinal metaplasia Weight loss Vomiting Dysplasia Iron deficiency anaemia Upper abdominal mass Atrophic gastritis Upper abdominal mass Jaundice Patient aged over 55 years with unexplained or persistent dyspepsia Staging CT scanning of the chest abdomen and pelvis is the routine first line staging investigation in most centres. Laparoscopy to identify occult peritoneal disease PET CT (particularly for junctional tumours) Treatment Proximally sited disease greater than 5-10cm from the OG junction may be treated by sub total gastrectomy Total gastrectomy if tumour is <5cm from OG junction For type 2 junctional tumours (extending into oesophagus) oesophagogastrectomy is usual Endoscopic sub mucosal resection may play a role in early gastric cancer confined to the mucosa and perhaps the sub mucosa (this is debated) Lymphadenectomy should be performed. A D2 lymphadenectomy is widely advocated by the Japanese, the survival advantages of extended lymphadenectomy have been debated. However, the overall recommendation is that a D2 nodal dissection be undertaken. Most patients will receive chemotherapy either pre or post operatively. Prognosis UK Data Disease extent Percentage 5 year survival All RO resections 54% Early gastric cancer 91% Stage 1 87% Stage 2 65% Stage 3 18% Operative procedure Total Gastrectomy , lymphadenectomy and Roux en Y anastomosis General anaesthesia Prophylactic intravenous antibiotics Incision: Rooftop. Perform a thorough laparotomy to identify any occult disease. Mobilise the left lobe of the liver off the diaphragm and place a large pack over it. Insert a large self retaining retractor e.g. omnitract or Balfour (take time with this, the set up should be perfect). Pack the small bowel away. Begin by mobilising the omentum off the transverse colon. Proceed to detach the short gastric vessels. Mobilise the pylorus and divide it at least 2cm distally using a linear cutter stapling device. Continue the dissection into the lesser sac taking the lesser omentum and left gastric artery flush at its origin. The lymph nodes should be removed en bloc with the specimen where possible. Place 2 stay sutures either side of the distal oesophagus. Ask the anaesthetist to pull back on the nasogastric tube. Divide the distal oesophagus and remove the stomach. The oesphago jejunal anastomosis should be constructed. Identify the DJ flexure and bring a loop of jejunum up to the oesophagus (to check it will reach). Divide the jejunum at this point. Bring the divided jejunum either retrocolic or antecolic to the oesophagus. Anastamose the oesophagus to the jejunum, using either interrupted 3/0 vicryl or a stapling device. Then create the remainder of the Roux en Y reconstruction distally. Place a jejunostomy feeding tube. Wash out the abdomen and insert drains (usually the anastomosis and duodenal stump). Help the anaesthetist insert the nasogastric tube (carefully!) Close the abdomen and skin. Enteral feeding may commence on the first post-operative day. However, most surgeons will leave patients on free NG drainage for several days and keep them nil by mouth.

Answer 1239

The Nottingham prognostic index may be used to stratify patients into various prognostic groups (see below). An excellent prognosis is seen with a score of <2.4. Scores of over 5 equate to a greatly reduced survival rate. Nottingham prognostic index The Nottingham Prognostic Index can be used to give an indication of survival following breast cancer surgery. In this system, the tumour size is weighted less heavily than other major prognostic parameters. Calculation of NPI Tumour Size x 0.2 + Lymph node score(From table below)+Grade score(From table below). Score Lymph nodes involved Grade 1 0 1 2 1-3 2 3 >3 3 Prognosis Score Percentage 5 year survival 2.0 to 2.4 93% 2.5 to 3.4 85% 3.5 to 5.4 70% >5.4 50% This data was originally published in 1992. It should be emphasised that other factors such as vascular invasion and receptor status also impact on survival and are not included in this data and account for varying prognoses often cited in the literature. Reference Galea, M.H., et al., The Nottingham Prognostic Index in primary breast cancer. Breast Cancer Res Treat, 1992. 22(3): p. 207-19.

Answer 1240

At this position the oesophagus is still likely to be intrathoracic and located in the posterior mediastinum. Mediastinum Region between the pulmonary cavities. It is covered by the mediastinal pleura. It does not contain the lungs. It extends from the thoracic inlet superiorly to the diaphragm inferiorly. Mediastinal regions Superior mediastinum (between manubriosternal angle and T4/5) Middle mediastinum Posterior mediastinum Anterior mediastinum Region Contents Superior mediastinum Superior vena cava Brachiocephalic veins Arch of aorta Thoracic duct Trachea Oesophagus Thymus Vagus nerve Left recurrent laryngeal nerve Phrenic nerve Anterior mediastinum Thymic remnants Lymph nodes Fat Middle mediastinum Pericardium Heart Aortic root Arch of azygos vein Main bronchi Posterior mediastinum Oesophagus Thoracic aorta Azygos vein Thoracic duct Vagus nerve Sympathetic nerve trunks Splanchnic nerves

Answer 1241

Ansa cervicalis is a content of the anterior triangle of the neck. Posterior triangle of the neck Boundaries Apex Sternocleidomastoid and the Trapezius muscles at the Occipital bone Anterior Posterior border of the Sternocleidomastoid Posterior Anterior border of the Trapezius Base Middle third of the clavicle Contents Nerves Accessory nerve Phrenic nerve Three trunks of the brachial plexus Branches of the cervical plexus: Supraclavicular nerve, transverse cervical nerve, great auricular nerve, lesser occipital nerve Vessels External jugular vein Subclavian artery Muscles Inferior belly of omohyoid Scalene Lymph nodes Supraclavicular Occipital

Answer 1242

Infliximab is a popular choice in managing complex peri anal Crohns. It is absolutely vital that all sepsis is drained prior to starting therapy. Biological agents Agents Target Uses Adalimumab Infliximab Etanercept TNF alpha inhibitor Crohns disease Rheumatoid disease Bevacizumab Anti VEGF (anti angiogenic) Colorectal cancer Renal Glioblastoma Trastuzumab HER receptor Breast cancer Imatinib Tyrosine kinase inhibitor Gastrointestinal stromal tumours Chronic myeloid leukaemia Basiliximab IL2 binding site Renal transplants Cetuximab Epidermal growth factor inhibitor EGF positive colorectal cancers Detailed understanding of the actions of biological agents is well beyond the scope of the MRCS syllabus. However, many of these drugs are being frequently encountered in surgical patients.

Answer 1243

The patient has a frailty fracture and by definition therefore will have osteoporosis and should therefore commence treatment, a DEXA scan will not change this decision. The osteoporosis guidelines state if a postmenopausal woman has a fracture she should be put on bisphosphonates (there is no need for a DEXA scan). Osteoporosis Osteoporosis is a condition of bone atrophy. It is a lesion in which the volume of bone tissue per unit volume of anatomical bone is reduced. It may be generalized (most common) or localized (following pressure or disuse). The hallmark is a reduction in the amount of osteoid matrix, which, however, remains normally mineralized. It is therefore distinct from osteomalacia in which there is abundant osteoid which is poorly calcified. In osteoporosis the bony trabeculae are greatly thinned which significantly reduces the tensile strength of the bone and renders it at increased risk of pathological fracture. It is only visible on plain films when the calcium content is approximately halved. More subtle changes can be appreciated by use of DEXA scanning. Treatment Fractures are treated according to their site and mechanism of injury. Those deemed to occur as a result of osteoporosis should also be addressed medically to treat the underlying osteoporosis. Drugs that can be prescribed to prevent fragility fractures include bisphosphonates (alendronate, ibandronate, risedronate and zoledronic acid) and non-bisphosphonates (raloxifene, denosumab, teriparatide, calcitriol and hormone replacement therapy). Calcium and vitamin D supplements are also administered. Individuals at risk of fragility fractures should also be considered for prophylactic medical treatment as outlined above.

Answer 1244

Loss of plasma proteins is the most common cause of oedema developing in this time frame. Burns pathology Extensive burns Haemolysis due to damage of erythrocytes by heat and microangiopathy Loss of capillary membrane integrity causing plasma leakage into interstitial space Extravasation of fluids from the burn site causing hypovolaemic shock (up to 48h after injury)- decreased blood volume and increased haematocrit Protein loss Secondary infection e.g. Staphylococcus aureus ARDS Risk of Curlings ulcer (acute peptic stress ulcers) Danger of full thickness circumferential burns in an extremity as these may develop compartment syndrome Healing Superficial burns: keratinocytes migrate to form a new layer over the burn site Full thickness burns: dermal scarring. Usually need keratinocytes from skin grafts to provide optimal coverage.

Answer 1245

A sudden collapse and loss of consciousness is most likely to be due to a sub arachnoid haemorrhage. The other potential causes in the list usually occur as a sequel to a traumatic event, which has not occurred here. Intra cranial haemorrhage Extradural haematoma Bleeding into the space between the dura mater and the skull. Often results from acceleration-deceleration trauma or a blow to the side of the head. The majority of extradural haematomas occur in the temporal region where skull fractures cause a rupture of the middle meningeal artery. Features Raised intracranial pressure Some patients may exhibit a lucid interval Subdural haematoma Bleeding into the outermost meningeal layer. Most commonly occur around the frontal and parietal lobes. May be either acute or chronic. Risk factors include old age and alcoholism. Slower onset of symptoms than a extradural haematoma. Intracerebral haematoma Usually hyperdense lesions on CT scanning. Arise in areas of traumatic contusion which fuse to become a haematoma. Areas of clot and fresh blood may co-exist on the same CT scan (Swirl sign). Large haematomas and those associated with mass effect should be evacuated. Subarachnoid haemorrhage Usually occurs spontaneously in the context of a ruptured cerebral aneurysm but may be seen in association with other injuries when a patient has sustained a traumatic brain injury Intraventricular haemorrhage Haemorrhage that occurs into the ventricular system of the brain. It is relatively rare in adult surgical practice and when it does occur, it is typically associated with severe head injuries. In premature neonates it may occur spontaneously. The blood may clot and occlude CSF flow, hydrocephalus may result. In neonatal practice the vast majority of IVH occur in the first 72 hours after birth, the aetiology is not well understood and it is suggested to occur as a result of birth trauma combined with cellular hypoxia, together with the delicate neonatal CNS.

Answer 1246

Tumour necrosis factor Tumour necrosis factor (TNF) is a pro-inflammatory cytokine with multiple roles in the immune system TNF is secreted mainly by macrophages and has a number of effects on the immune system, acting mainly in a paracrine fashion: activates macrophages and neutrophils acts as costimulator for T cell activation key mediator of body's response to Gram negative septicaemia similar properties to IL-1 anti-tumour effect (e.g. phospholipase activation) TNF-alpha binds to both the p55 and p75 receptor. These receptors can induce apoptosis. It also cause activation of NFkB Endothelial effects include increase expression of selectins and increased production of platelet activating factor, IL-1 and prostaglandins TNF promotes the proliferation of fibroblasts and their production of protease and collagenase. It is thought fragments of receptors act as binding points in serum Systemic effects include pyrexia, increased acute phase proteins and disordered metabolism leading to cachexia TNF is important in the pathogenesis of rheumatoid arthritis - TNF blockers (e.g. infliximab, etanercept) are now licensed for treatment of severe rheumatoid

Answer 1247

The main pancreatic duct is largely formed from the duct of the ventral pancreas having fused with the dorsal part of the gland. Pancreatic embryology The pancreas develops from a ventral and dorsal entodermal outgrowth from the duodenum. The ventral arises close to, or in common with, the hepatic diverticulum, and the larger, dorsal outgrowth arises slightly cranial to the ventral and extends into the mesoduodenum and dorsal mesogastrium. As a result of the differential growth in the duodenal wall, the point of attachment of the ventral outgrowth with the undivided stem of the hepatic diverticulum and the ventral mesentery are displaced around the right hand side of the duodenum to a dorsal position. As a result, the two pancreatic remnants eventually lie together and then become fused. In this process the ventral rudiment forms the uncinate process and the adjacent region of the head, while the dorsal forms the anterior part of the head, the body and the tail of the pancreas. At the time of fusion, the ducts become joined. This occurs in a manner that results in the dorsal remnant being drained by the duct of the ventral remnant, this composite duct being named the pancreatic duct.

Answer 1248

This is likely to be a case of tertiary hyperparathyroidism (high Calcium, high PTH, low phosphate). Therefore the glands will be hyperplastic. Hypertrophy is not correct as this implies an increase in size without an increase in cellularity. This mistake has cost many candidates marks in the MRCS exams over the years! Parathyroid glands and disorders of calcium metabolism Hyperparathyroidism Disease type Hormone profile Clinical features Cause Primary hyperparathyroidism PTH (Elevated) Ca2+ (Elevated) Phosphate (Low) Urine calcium : creatinine clearance ratio > 0.01 May be asymptomatic if mild Recurrent abdominal pain (pancreatitis, renal colic) Changes to emotional or cognitive state Most cases due to solitary adenoma (80%), multifocal disease occurs in 10-15% and parathyroid carcinoma in 1% or less Secondary hyperparathyroidism PTH (Elevated) Ca2+ (Low or normal) Phosphate (Elevated) Vitamin D levels (Low) May have few symptoms Eventually may develop bone disease, osteitis fibrosa cystica and soft tissue calcifications Parathyroid gland hyperplasia occurs as a result of low calcium, almost always in a setting of chronic renal failure Tertiary hyperparathyroidism Ca2+ (Normal or high) PTH (Elevated) Phosphate levels (Decreased or Normal) Vitamin D (Normal or decreased) Alkaline phosphatase (Elevated) Metastatic calcification Bone pain and / or fracture Nephrolithiasis Pancreatitis Occurs as a result of ongoing hyperplasia of the parathyroid glands after correction of underlying renal disorder, hyperplasia of all 4 glands is usually the cause Differential diagnoses It is important to consider the rare but relatively benign condition of benign familial hypocalciuric hypercalcaemia, caused by an autosomal dominant genetic disorder. Diagnosis is usually made by genetic testing and concordant biochemistry (urine calcium : creatinine clearance ratio <0.01-distinguished from primary hyperparathyroidism). Treatment Primary hyperparathyroidism Indications for surgery Elevated serum Calcium > 1mg/dL above normal Hypercalciuria > 400mg/day Creatinine clearance < 30% compared with normal Episode of life threatening hypercalcaemia Nephrolithiasis Age < 50 years Neuromuscular symptoms Reduction in bone mineral density of the femoral neck, lumbar spine, or distal radius of more than 2.5 standard deviations below peak bone mass (T score lower than -2.5) Secondary hyperparathyroidism Usually managed with medical therapy. Indications for surgery in secondary (renal) hyperparathyroidism: Bone pain Persistent pruritus Soft tissue calcifications Tertiary hyperparathyroidism Allow 12 months to elapse following transplant as many cases will resolve The presence of an autonomously functioning parathyroid gland may require surgery. If the culprit gland can be identified then it should be excised. Otherwise total parathyroidectomy and re-implantation of part of the gland may be required. References 1. Insogna K. Primary Hyperparathyroidism. N Engl J Med. 2018 Sep 13;379(11):1050-1059. 2. van der Plas W Y et al. Secondary and Tertiary Hyperparathyroidism: A Narrative Review. Scand J Surg. 2020 Dec;109(4):271-278.

Answer 1249

Streptococcus pyogenes Quinsy usually occurs as a result of bacterial tonsillitis and the most common cause of bacterial tonsillitis is streptococcal organisms. Acute tonsillitis Characterised by pharyngitis, fever, malaise and lymphadenopathy. Over half of all cases are bacterial with Streptococcus pyogenes the most common organism The tonsils are typically oedematous and yellow or white pustules may be present Infectious mononucleosis may mimic the condition. Treatment with penicillin type antibiotics is indicated for bacterial tonsillitis. Bacterial tonsillitis may result in local abscess formation (quinsy)

Answer 1250

Although fibrillin is the primary protein affected (due to a defect in the fibrillin-1 gene) it should be noted that fibrillin is used as a substrate of elastin. Marfan's syndrome Marfan's syndrome is an autosomal dominant connective tissue disorder. It is caused by a defect in the fibrillin-1 gene on chromosome 15 and affects around 1 in 3,000 people. Features tall stature with arm span to height ratio > 1.05 high-arched palate arachnodactyly pectus excavatum pes planus scoliosis of > 20 degrees heart: dilation of the aortic sinuses (seen in 90%) which may lead to aortic aneurysm, aortic dissection, aortic regurgitation, mitral valve prolapse (75%), lungs: repeated pneumothoraces eyes: upwards lens dislocation (superotemporal ectopia lentis), blue sclera, myopia dural ectasia (ballooning of the dural sac at the lumbosacral level) The life expectancy of patients used to be around 40-50 years. With the advent of regular echocardiography monitoring and beta-blocker/ACE-inhibitor therapy this has improved significantly over recent years. Aortic dissection and other cardiovascular problems remain the leading cause of death however.

Answer 1251

In the Babinski sign, the normal flexor sign becomes extensor and pyramidal tract lesions can cause UMN signs. Babinski sign Joseph Babinski (1857â€“1932), a French neurologist of Polish descent, first described the Babinski sign, the best known neurological eponym and one of the most important signs in clinical neurology, in 1896. It is assessed as follows; the first line to be stroked begins a few centimeters distal to the heel and is situated at the junction of the dorsal and plantar surfaces of the foot. The line extends to a point just behind the toes and then turns medially across the transverse arch of the foot. It is a slow stroke, taking 5 or 6 seconds to complete the motion. The response is pathological if the toe is moved upwards by contraction of extensor hallucis longus muscle. Its is a sign of upper motor neurone pathology.

Answer 1252

Muscles supplied by the radial nerve BEST Brachioradialis Extensors Supinator Triceps The radial nerve supplies the extensor muscles, abductor pollicis longus and extensor pollicis brevis (the latter two being innervated by the posterior interosseous branch of the radial nerve).

Answer 1253

A history of gastrectomy and a macrocytic anaemia should indicate a diagnosis of B12 deficiency. Vitamin B12 deficiency Vitamin B12 is mainly used in the body for red blood cell development and also maintenance of the nervous system. It is absorbed after binding to intrinsic factor (secreted from parietal cells in the stomach) and is actively absorbed in the terminal ileum. A small amount of vitamin B12 is passively absorbed without being bound to intrinsic factor. Causes of vitamin B12 deficiency pernicious anaemia post gastrectomy poor diet disorders of terminal ileum (site of absorption): Crohn's, blind-loop etc Features of vitamin B12 deficiency macrocytic anaemia sore tongue and mouth neurological symptoms: e.g. Ataxia neuropsychiatric symptoms: e.g. Mood disturbances Management if no neurological involvement 1 mg of IM hydroxocobalamin 3 times each week for 2 weeks, then once every 3 months if a patient is also deficient in folic acid then it is important to treat the B12 deficiency first to avoid precipitating subacute combined degeneration of the cord

Answer 1254

Subclavian steal syndrome characteristically presents with posterior circulation symptoms, such as dizziness and vertigo, during exertion of an arm. There is subclavian artery steno-occlusive disease proximal to the origin of the vertebral artery and is associated with flow reversal in the vertebral artery. Management involves percutaneous transluminal angioplasty or a stent. Subclavian artery Path The left subclavian comes directly off the arch of aorta The right subclavian arises from the brachiocephalic artery (trunk) when it bifurcates into the subclavian and the right common carotid artery. From its origin, the subclavian artery travels laterally, passing between anterior and middle scalene muscles, deep to scalenus anterior and anterior to scalenus medius. As the subclavian artery crosses the lateral border of the first rib, it becomes the axillary artery. At this point it is superficial and within the subclavian triangle. Branches Vertebral artery Internal thoracic artery Thyrocervical trunk Costocervical trunk Dorsal scapular artery

Answer 1255

The fact that ward based analgesia has been tried suggests that the patient be considered for palliative radiotherapy. Surgical resection of prostate cancer bony metastatic disease is not generally performed. Management of pain World Health Organisation Analgesic Ladder Initially peripherally acting drugs such as paracetamol or non-steroidal anti-inflammatory drugs (NSAIDs) are given. If pain control is not achieved, the second part of the ladder is to introduce weak opioid drugs such as codeine or dextropropoxyphene together with appropriate agents to control and minimise side effects. The final rung of the ladder is to introduce strong opioid drugs such as morphine. Analgesia from peripherally acting drugs may be additive to that from centrally-acting opioids and thus, the two are given together. The World Federation of Societies of Anaesthesiologists (WFSA) Analgesic Ladder For management of acute pain Initially, the pain can be expected to be severe and may need controlling with strong analgesics in combination with local anaesthetic blocks and peripherally acting drugs. The second rung on the postoperative pain ladder is the restoration of the use of the oral route to deliver analgesia. Strong opioids may no longer be required and adequate analgesia can be obtained by using combinations of peripherally acting agents and weak opioids. The final step is when the pain can be controlled by peripherally acting agents alone. Local anaesthetics Infiltration of a wound with a long-acting local anaesthetic such as Bupivacaine Analgesia for several hours Further pain relief can be obtained with repeat injections or by infusions via a thin catheter Blockade of plexuses or peripheral nerves will provide selective analgesia in those parts of the body supplied by the plexus or nerves Can either be used to provide anaesthesia for the surgery or specifically for postoperative pain relief Especially useful where a sympathetic block is needed to improve postoperative blood supply or where central blockade such as spinal or epidural blockade is contraindicated. Spinal anaesthesia Provides excellent analgesia for surgery in the lower half of the body and pain relief can last many hours after completion of the operation if long-acting drugs containing vasoconstrictors are used. - Side effects of spinal anaesthesia include: hypotension, sensory and motor block, nausea and urinary retention. Epidural anaesthesia An indwelling epidural catheter inserted. This can then be used to provide a continuous infusion of analgesic agents. It can provide excellent analgesia. They are still the preferred option following major open abdominal procedures and help prevent post operative respiratory compromise resulting from pain. - Disadvantages of epidurals is that they usually confine patients to bed, especially if a motor block is present. In addition an indwelling urinary catheter is required. Which may not only impair mobility but also serve as a conduit for infection. They are contraindicated in coagulopathies. Transversus Abdominal Plane block (TAP) In this technique an ultrasound is used to identify the correct muscle plane and local anaesthetic (usually bupivicaine) is injected. The agent diffuses in the plane and blocks many of the spinal nerves. It is an attractive technique as it provides a wide field of blockade but does not require the placement of any indwelling devices. There is no post operative motor impairment. For this reason it is the preferred technique when extensive laparoscopic abdominal procedures are performed. They will then provide analgesia immediately following surgery but as they do not confine the patient to bed, the focus on enhanced recovery can begin sooner. -The main disadvantage is that their duration of action is limited to the half life of the local anaesthetic agent chosen. In addition some anaesthetists do not have the USS skills required to site the injections. Patient Controlled Analgesia (PCA) - Patients administer their own intravenous analgesia and titrate the dose to their own end-point of pain relief using a small microprocessor - controlled pump. Morphine is the most popular drug used. Strong Opioids Severe pain arising from deep or visceral structures requires the use of strong opioids Morphine Short half life and poor bioavailability. Metabolised in the liver and clearance is reduced in patients with liver disease, in the elderly and the debilitated Side effects include nausea, vomiting, constipation and respiratory depression. Tolerance may occur with repeated dosage Pethidine Synthetic opioid which is structurally different from morphine but which has similar actions. Has 10% potency of morphine. Short half life and similar bioavailability and clearance to morphine. Short duration of action and may need to be given hourly. Pethidine has a toxic metabolite (norpethidine) which is cleared by the kidney, but which accumulates in renal failure or following frequent and prolonged doses and may lead to muscle twitching and convulsions. Extreme caution is advised if pethidine is used over a prolonged period or in patients with renal failure. Weak opioids Codeine: markedly less active than morphine, has predictable effects when given orally and is effective against mild to moderate pain. Non opioid analgesics - Mild to moderate pain. Paracetamol Inhibits prostaglandin synthesis. Analgesic and antipyretic properties but little anti-inflammatory effect It is well absorbed orally and is metabolised almost entirely in the liver Side effects in normal dosage and is widely used for the treatment of minor pain. It causes hepatotoxicity in over dosage by overloading the normal metabolic pathways with the formation of a toxic metabolite. NSAIDs Analgesic and anti-inflammatory actions Inhibition of prostaglandin synthesis by the enzyme Cyclooxygenase which catalyses the conversion of arachidonic acid to the various prostaglandins that are the chief mediators of inflammation. All NSAIDs work in the same way and thus there is no point in giving more than one at a time. . NSAIDs are, in general, more useful for superficial pain arising from the skin, buccal mucosa, joint surfaces and bone. Relative contraindications: history of peptic ulceration, gastrointestinal bleeding or bleeding diathesis; operations associated with high blood loss, asthma, moderate to severe renal impairment, dehydration and any history of hypersensitivity to NSAIDs or aspirin. Neuropathic pain National Institute of Clinical Excellence (UK) guidelines: First line: Amitriptyline (Imipramine if cannot tolerate) or pregabalin Second line: Amitriptyline AND pregabalin Third line: refer to pain specialist. Give tramadol in the interim (avoid morphine) If diabetic neuropathic pain: Duloxetine As of 1 April 2019, pregabalin and gabapentin are Class C controlled substances (under the Misuse of Drugs Act 1971) and scheduled under the Misuse of Drugs Regulations 2001 as Schedule 3. Evaluate patients carefully for a history of drug abuse before prescribing and observe patients for development of signs of abuse and dependence (MHRA, Drug Safety Update April 2019). References 1. http://guidance.nice.org.uk/CG173/Guidance/pdf/English 2. Lovich-Sapola J, Smith CE, Brandt CP. Post operative pain control. Surg Clin North Am. 2015 Apr;95(2):301-183. Finnerup N et al. Pharmacotherapy for neuropathic pain in adults: a systematic review and meta-analysis. Lancet Neurol. 2015 Feb;14(2):162-73.

Answer 1256

The sympathetic nervous system stimulates renin release from juxtaglomerular cells via the beta adrenoreceptor cAMP pathway Renin Renin is secreted by juxtaglomerular cells and hydrolyses angiotensinogen to produce angiotensin I Factors stimulating renin secretion Hypotension causing reduced renal perfusion Hyponatraemia Sympathetic nerve stimulation Catecholamines Erect posture Factors reducing renin secretion Drugs: beta-blockers, NSAIDs

Answer 1257

Packing of the liver is the safest option and resection or repair considered later when the physiology is normalised. Often when the packs are removed all the bleeding has ceased and the abdomen can be closed without further action. Definitive attempts at suturing or resection at the primary laparotomy are often complicated by severe bleeding. Trauma management The cornerstone of trauma management is embodied in the principles of ATLS. Following trauma there is a trimodal death distribution: Immediately following injury. Typically as result of brain or high spinal injuries, cardiac or great vessel damage. Salvage rate is low. In early hours following injury. In this group deaths are due to phenomena such as splenic rupture, sub dural haematomas and haemopneumothoraces In the days following injury. Usually due to sepsis or multi organ failure. Aspects of trauma management ABCDE approach. Tension pneumothoraces will deteriorate with vigorous ventilation attempts. External haemorrhage is managed as part of the primary survey. As a rule tourniquets should not be used. Blind application of clamps will tend to damage surrounding structures and packing is the preferred method of haemorrhage control. Urinary catheters and naso gastric tubes may need inserting. Be wary of basal skull fractures and urethral injuries. Patients with head and neck trauma should be assumed to have a cervical spine injury until proven otherwise. Thoracic injuries Simple pneumothorax Mediastinal traversing wounds Tracheobronchial tree injury Haemothorax Blunt cardiac injury Diaphragmatic injury Aortic disruption Pulmonary contusion Management of thoracic trauma Simple pneumothorax insert chest drain. Aspiration is risky in trauma as pneumothorax may be from lung laceration and convert to tension pneumothorax. Mediastinal traversing wounds These result from situations like stabbings. Exit and entry wounds in separate hemithoraces. The presence of a mediastinal haematoma indicates the likelihood of a great vessel injury. All patients should undergo CT angiogram and oesophageal contrast swallow. Indications for thoracotomy are largely related to blood loss and will be addressed below. Tracheobronchial tree injury Unusual injuries. In blunt trauma most injuries occur within 4cm of the carina. Features suggesting this injury include haemoptysis and surgical emphysema. These injuries have a very large air leak and may have tension pneumothorax. Haemothorax Usually caused by laceration of lung vessel or internal mammary artery by rib fracture. Patients should all have a wide bore 36F chest drain. Indications for thoracotomy include loss of more than 1.5L blood initially or ongoing losses of >200ml per hour for >2 hours. Cardiac contusions Usually cardiac arrhythmias, often overlying sternal fracture. Perform echocardiography to exclude pericardial effusions and tamponade. Risk of arrhythmias falls after 24 hours. Diaphragmatic injury Usually left sided. Direct surgical repair is performed. Traumatic aortic disruption Commonest cause of death after RTA or falls. Usually incomplete laceration near ligamentum arteriosum. All survivors will have contained haematoma. Only 1-2% of patients with this injury will have a normal chest x-ray. Pulmonary contusion Common and lethal. Insidious onset. Early intubation and ventilation. Abdominal trauma Deceleration injuries are common. In blunt trauma requiring laparotomy the spleen is most commonly injured (40%) Stab wounds traverse structures most commonly liver (40%) Gunshot wounds have variable effects depending upon bullet type. Small bowel is most commonly injured (50%) Patients with stab wounds and no peritoneal signs up to 25% will not enter the peritoneal cavity Blood at urethral meatus suggests a urethral tear High riding prostate on PR = urethral disruption Mechanical testing for pelvic stability should only be performed once Investigations in abdominal trauma Diagnostic Peritoneal Lavage Abdominal CT scan USS Indication Document bleeding if hypotensive Document organ injury if normotensive Document fluid if hypotensive Advantages Early diagnosis and sensitive; 98% accurate Most specific for localising injury; 92 to 98% accurate Early diagnosis, non invasive and repeatable; 86 to 95% accurate Disadvantages Invasive and may miss retroperitoneal and diaphragmatic injury Location of scanner away from facilities, time taken for reporting, need for contrast Operator dependent and may miss retroperitoneal injury Amylase may be normal following pancreatic trauma Urethrography if suspected urethral injury

Answer 1258

An incision at this level lies below the arcuate line and the posterior wall of the rectus sheath is deficient at this level. Rectus abdominis muscle The rectus sheath is formed by the aponeuroses of the lateral abdominal wall muscles. The rectus sheath has a composition that varies according to anatomical level. 1. Above the costal margin the anterior sheath is composed of external oblique aponeurosis, the costal cartilages are posterior to it. 2. From the costal margin to the arcuate line, the anterior rectus sheath is composed of external oblique aponeurosis and the anterior part of the internal oblique aponeurosis. The posterior part of the internal oblique aponeurosis and transversus abdominis form the posterior rectus sheath. 3. Below the arcuate line the aponeuroses of all the abdominal muscles lie in anterior aspect of the rectus sheath. Posteriorly lies the transversalis fascia and peritoneum. The arcuate line is the point at which the inferior epigastric vessels enter the rectus sheath.

Answer 1259

This is a peripheral neuropathy that may complicate viral illnesses and usually resolves spontaneously. Shoulder disorders Shoulder fractures and dislocations Fractures Proximal humerus Background Third most common fragility fracture in the elderly. Results from low energy fall in predominantly elderly females, or from high energy trauma in young males. Can be associated with nerve injury (commonly axillary), and fracture-dislocation of the humeral head. Detailed neurological assessment is essential for all upper limb injuries. Anatomy Osteology Consists of articular head, greater tuberosity, lesser tuberosity, metaphysis and diaphysis. Between the articular head and the tuberosities is the anatomical neck (previous physis). Between the tuberosities and the metaphysis is the surgical neck. The supraspinatus, infraspinatus and teres minor muscles attach to the greater tuberosity. The subscapularis muscle attaches to the lesser tuberosity. Vascular Supply Humeral head is supplied by the anterior and posterior humeral circumflex arteries. Anatomical neck fractures are at greatest risk of osteonecrosis. Imaging Imaging aims to both delineate the fracture pattern, and confirm/exlude the presence of an associated dislocation. Radiographs - True anteroposterior (AP), axillary lateral and/or scapula Y view. CT - indicated to better define intra-articular involvement and to aid pre-operative planning. MRI is not useful for fracture imaging. Classification Description of the fracture is often more useful than classification. Particular attention should be paid to humeral alignment, fracture displacement, and greater tuberosity position (rotator cuff will pull the GT supero-posterioly, which can cause impingement problems with malunion). - Neer Classification: Most commonly used. Describes fracture as 2,3,or 4 part depending upon the number main fragments. Also comments on the degree of displacement. Fragments: -greater tuberosity -lesser tuberosity - articular surface - shaft Displacement: >1cm or angulation >45 degrees. Treatment The vast majority of proximal humeral fractures are minimally displaced, and therefore can be managed conservatively. This involves immobilisation in a polysling, and progressive mobilisation. Pendular exercise can commence at 14 days, and active abduction from 4-6 weeks. Irreducible fracture dislocation is an indication for operative management. Other indications include large displacement, younger patient, head splitting (intra-articular fractures). However, the recent PROFHER trial (1) has suggested no benefit to operative intervention on patient outcome (it must be applied cautiously as majority of patients were elderly with extraarticular fractures). Options available for surgical management include: ORIF Most commonly used. Plate and screw fixation. Can reconstruct complex fractures. Intramedullary nail Suitable for extra-articular configuration, predominantly surgical neck +/- GT fractures. Hemiarthroplasty Used for un-reconstructable fractures in the older patient who has good glenoid quality. Total shoulder arthroplasty Unconstructable fractures where high functioning shoulder is required (hemiarthroplasty will cause glenoid erosion) Reverse shoulder arthroplasty Total shoulder arthroplasty that provides better functional outcome than conventional total shoulder replacement. Scapula Background Uncommon fractures usually associated with high energy trauma. Most commonly involve scapula body or spine (50%), glenoid fossa and glenoid neck. Important to exclude associated life threatening injury. Imaging Plain radiographs should include true anteroposterior (AP), axillary lateral and/or scapula Y view. CT scanning is useful for defining intra-articular involvement, displacement and for three dimensional reconstruction. Classification Based on the location of the fracture (coracoid, acromion, glenoid neck, glenoid fossa, scapula body). Beware of ipsilateral glenoid neck and clavicle fracture -floating shoulder - where limb is effectively dissociated from axial skeleton. Treatment The vast majority of scapula fractures are amenable to conservative management, consisting of sling immobilisation for two weeks followed by early rehabilitation. Floating shoulder will usually require fixation, and consideration of surgery should also be given to intra-articular and displaced/angulated glenoid fractures. Dislocations Types Dislocations around the shoulder joint include glenohumeral dislocation, acromioclavicular joint disruption and sternoclavicular dislocation. Only glenohumeral dislocation will be covered here. Glenohumeral dislocation Diagnosis, classification and management are covered here. Background Shoulder dislocation is commonly seen in A&E. It has a high recurrence rate that is as high as 80% in teenagers. Initial management requires emergent reduction to prevent lasting chondral damage. Early assessment and management Usually a traumatic cause (multi-directional instability in frequent dislocations requires discussion with orthopaedics and is not covered here). Careful history, examination and documentation of neurovascular status of the limb, in particular the axillary nerve (regimental badge sensation). This should be re-assessed post manipulation. Early radiographs to confirm direction of dislocation. Initial management consists of emergent closed reduction under under entanox and analgesia, but often requires conscious sedation. Arm should then be immobilised in a polysling, and XR to confirm relocation. Imaging - True anteroposterior (AP), axillary lateral and/or scapula Y view. Reduced humeral head should lie between acromion and coracoid on lateral/scapula view. Types Direction Features Cause Examination Reduction techniques Anterior Most Common >90% Usually traumatic - anterior force on arm when shoulder is abducted, externally rotated Loss of shoulder contour - sulcus sign. Humeral head can be felt anteriorly. Hippocratic. Milch. Stimson. Kocher not advised due to complication of fracture Posterior 50% missed in A&E 50% traumatic, but classically post seizure or electrocution Shoulder locked in internal rotation. XR may show lightbulb appearance. Gentle lateral traction to adducted arm. Inferior Rare Associated with pectorals and rotator cuff tears, and glenoid fracture As for primary injury Management of primary injury Superior Rare Associated with acrominon/clavicle fracture As for primary injury Management of primary injury Associated injuries Bankart lesion - avulsion of the anterior glenoid labrum with an anterior shoulder dislocation (reverse Bankart if poster labrum in posterior dislocation). Hill Sachs defect - chondral impaction on posteriosuperior humeral head from contact with gleonoid rim. Can be large enough to lock shoulder, requiring open reduction. (Reverse Hill Sachs in posterior dislocation). Rotator cuff tear - increases with age. Greater or lesser tuberosity fracture - increases with age. Humeral neck fracture - shoulder fracture dislocation. More common in high energy trauma and elderly. Should be discussed with orthopaedics prior to any attempted reduction. Rotator Cuff Disease Rotator cuff disease is a spectrum of conditions that ranges from subacromial impingement to rotator cuff tears and eventually to rotator cuff arthropathy (arthritis). Anatomy The rotator cuff is a group of four muscles that are important in shoulder movements, and maintenance of glenohumeral stability. Muscle Scapular attachment Humeral attachment Action Innervation Supraspinatus Supraspinatus fossa Superior facet of greater tuberosity Initiation of abduction of humerus Suprascapular nerve Infraspinatus Infraspinatus fossa Posterior facet of greater tuberosity External rotation of humerus Suprascapular nerve Teres Minor Lateral border Inferior facet of greater tuberosity External rotation of humerus Axillary Nerve Subscapularis Subscapular fossa Lesser tuberosity Internal rotation of humerus Upper and lower subscapular nerve The inferior rotator cuff muscles (infraspinatus, teres minor, and subscapularis) balance the superior pull of the deltoid. Injury/tear results in upward migration of the humeral head on the glenoid (can be seen on AP radiograph). Likewise, the anterior muscles (subscapularis) are balanced with the posterior muscles (infraspinatus, teres minor). Subacromial Impingement The most common cause of shoulder pain, which results from impingement of the superior cuff on the undersurface of the acromion, and an inflammatory bursitis. Associated with certain types of acromial morphology (Bigliani classification). Presents as insidious pain which is exacerbated by overhead activities. Rotator Cuff Tear Often presents as an acute event on the background of chronic subacromial impingement in the older patient, but can present as an avulsion injury in younger patients. Majority of tears are to the superior cuff (supraspinatus, infraspinatus, teres minor), though a tear to subscapularis is associated with subcoracoid impingement. Tears present as pain and weakness when using the muscles in question. Rotator Cuff Arthropathy Defined as shoulder arthritis in the setting of rotator cuff dysfunction. Results from superior migration due to the loss of rotator cuff function and integrity. Unopposed deltoid pulls the humeral head superiorly. Associated with massive chronic cuff tears. Imaging Plain radiographs AP of the shoulder may show superior migration of the humerus with a cuff tear, and features of arthritis with arthropathy. Other causes of pain may also be identified (e.g. calcific tendonitis/fracture) Outlet view is useful for defining the acromial morphology USS Allows dynamic imaging of the cuff, and is inexpensive. However, it is very user dependent. MRI Best imaging modality for cuff pathology. Also allows imaging of the rest of the shoulder. When intra-articular pathology is suspected, can be combined with an arthrogram for improved sensitivity and specificity. Treatment Subacromial impingement Physiotherapy, oral anti-inflammatory medication Subacromial steroid injection can settle inflammation Arthroscopic subacromial decompression by shaving away the undersurface of the acromion, more space is created for the rotator cuff. Cuff integrity is assessed also at time of surgery, and can be repaired if necessary. Rotator cuff tear When considering repair of a cuff tear, the age and activity of the patient, the nature of the tear (degenerative vs. acute traumatic), and the size and retraction of the tear should be considered when making a surgical plan. Mild tears or tears in the elderly can be managed conservatively, as outlined above. Moderate tears can be repaired arthroscopically. Massive or retracted tears will often require an open repair (occasionally with a tendon transfer). Subacromial decompression is performed at the same time to reduce impingement, symptoms and recurrence. Calcific tendonitis Calcific tendonitis involves calcific deposits within tendons anywhere in the body, but most commonly in the rotator cuff (specifically the supraspinatus tendon). When present in the shoulder, it is associated with subacromial impingement and pain. Pathology More common in women aged 30-60 years. Association with diabetes and hypothyroidism There are three stages of calcification Formative phase characterized by calcific deposits Resting phase deposit is stable, but presents with impingement problems Resorptive phase phagocytic resorption. Most painful stage. Presentation Similar in presentation to subacromial impingement, with pain especially with over head activities. Atraumatic in nature. Imaging Plain radiographs show calcification of the rotator cuff, usually within 1.5cm of its insertion on the humerus. Supraspinatus outlet views can show level of impingment. Further imaging is rarely needed. Treatment Non-operative NSAIDS, steroid injection (controversial, but practiced) and physiotherapy. Approximately 75% will resolve by 6 months with conservative management. Ultrasound guided or surgical needle barbotage can break down deposits and resolve symptoms. Occasionally surgical excision is required. Adhesive capsulitis (Frozen Shoulder) Pain and loss of movement of shoulder joint, which involves fibroplastic proliferation of capsular tissue, causing soft tissue scarring and contracture. Patients present with a painful and decreased arc of motion. Associated with prolonged immobilization, previous surgery, thyroid disorders (AI) and diabetes Classically three stages which can take up to two years to resolve: Stage one the freezing and painful stage Stage two the frozen and stiff stage Stage three the thawing stage, where shoulder movement slowly improves Imaging Plain radiographs to exclude other causes of a painful shoulder MRI arthrogram may show capsular contracture, and again may be used to exclude cuff pathology. However, often not performed as diagnosis is largely clinical. Treatment Non-operative NSAIDS, steroid injection and physiotherapy. Patience is required as condition can take up to 2 years to improve. Operative MUA or arthroscopic adhesiolysis (release of adhesions) can expedite recovery, followed by intensive physiotherapy. Glenohumeral Arthritis Background May be osteoarthritis (primary or secondary to cuff tear or trauma), rheumatoid arthritis, or as part of a spondyloarthropathy. Majority of those with RA will develop symptoms. More common in the elderly Presents like any other arthritis - pain at night and with movement Imaging AP and axillary radiographs will show features of arthritis. CT/MRI is often useful to classify the shape of the glenoid and extent of bone loss when considering arthroplasty. MRI also essential to asses integrity of rotator cuff if considering shoulder replacement. Treatment Like all orthopaedics, start with simple measures: NSAIDS, management of RA, physiotherapy, steroid injection. Hemiarthroplasty can sometimes be considered if glenoid is in excellent condition or if patient has large comorbidity. Arthroscopic debridement is useful if patient has isolated ACJ arthritis, but is rarely used for glenohumeral arthritis. Total shoulder replacement is shown to produce superior outcome when compared to hemiarthroplasty in terms of pain relief, function and implant survival. Total shoulder replacement can be anatomical (ball on humerus, with cup on glenoid), or reverse geometry (ball on glenoid, with cup on humerus). Anatomical TSR requires an in tact rotator cuff, so often reverse is preferable when the cuff if questionable in integrity. References 1. JAMA. 2015;313(10):1037-1047. doi:10.1001/jama.2015.1629

Answer 1260

Transection of a peripheral nerve results in hemorrhage and retraction of the severed nerve ends. Almost immediately, degeneration of the axon distal to the injury begins. Degeneration also occurs in the proximal fragment back to the first node of Ranvier. Phagocytosis of the degenerated axonal fragments leaves neurilemmal sheath with empty cylindrical spaces where the axons were. Several days following the injury, axons from the proximal fragment begin to regrow. If they make contact with the distal neurilemmal sheath, regrowth occurs at about the rate of 1 mm/day. However, if associated trauma, fracture, infection, or separation of neurilemmal sheath ends precludes contact between axons, growth is haphazard and a traumatic neuroma is formed. When neural transection is associated with widespread soft tissue damage and hemorrhage (with increased probability of infection), many surgeons choose to delay reapproximation of the severed nerve end for 3 to 4 weeks. Nerve injury There are 3 types of nerve injury: Neuropraxia Nerve intact but electrical conduction is affected Full recovery Autonomic function preserved Wallerian degeneration does not occur Axonotmesis Axon is damaged and the myelin sheath is preserved. The connective tissue framework is not affected. Wallerian degeneration occurs. Neurotmesis Disruption of the axon, myelin sheath and surrounding connective tissue. Wallerian degeneration occurs. Wallerian Degeneration Axonal degeneration distal to the site of injury. Typically begins 24-36 hours following injury. Axons are excitable prior to degeneration occurring. Myelin sheath degenerates and is phagocytosed by tissue macrophages. Nerve repair Neuronal repair may only occur physiologically where nerves are in direct contact. Where a large defect is present, the process of nerve regeneration is hampered. It may not occur at all or result in the formation of a neuroma. Where nerve regrowth occurs it is typically at a rate of 1mm per day.

Answer 1261

At the lower border of the femoral triangle the femoral artery passes under the sartorius muscle. This can be retracted to improve access. Femoral triangle anatomy Boundaries Superiorly Inguinal ligament Laterally Sartorius Medially Adductor longus Floor Iliopsoas, adductor longus and pectineus Roof Fascia lata and Superficial fascia Superficial inguinal lymph nodes (palpable below the inguinal ligament) Long saphenous vein Contents Femoral vein (medial to lateral) Femoral artery-pulse palpated at the mid inguinal point Femoral nerve Deep and superficial inguinal lymph nodes Lateral cutaneous nerve Great saphenous vein Femoral branch of the genitofemoral nerve

Answer 1262

External carotid artery branches mnemonic: 'Some Angry Lady Figured Out PMS' Superior thyroid (superior laryngeal artery branch) Ascending pharyngeal Lingual Facial (tonsillar and labial artery) Occipital Posterior auricular Maxillary (inferior alveolar artery, middle meningeal artery) Superficial temporal External carotid artery The external carotid commences immediately lateral to the pharyngeal side wall. It ascends and lies anterior to the internal carotid and posterior to the posterior belly of digastric and stylohyoid. More inferiorly it is covered by sternocleidomastoid, passed by hypoglossal nerves, lingual and facial veins. It then pierces the fascia of the parotid gland finally dividing into its terminal branches within the gland itself. Surface marking of the carotid This is an imaginary line drawn from the bifurcation of the common carotid passing behind the angle of the jaw to a point immediately anterior to the tragus of the ear. Branches of the external carotid artery It has six main branches, three in front, two behind and one deep. Three in front Superior thyroid Lingual Facial Two behind Occipital Posterior auricular Deep Ascending pharyngeal It terminates by dividing into the superficial temporal and maxillary arteries in the parotid gland.

Answer 1263

D-Cowden Disease PTEN is a tumour suppressor gene and loss of function mutations result in up regulation of the mTOR pathway. Polyposis syndromes Syndrome Genetic defect Features Screening and management Associated disorders Familial adenomatous polyposis Mutation of APC gene (80%) cases, dominant Typically over 100 colonic adenomas Cancer risk of 100% 20% are new mutations If known to be at risk then predictive genetic testing as teenager Annual flexible sigmoidoscopy from 15 years If no polyps found then 5 yearly colonoscopy started at age 20 Polyps found = resectional surgery (resection and pouch Vs sub total colectomy and IRA) Gastric fundal polyps (50%). Duodenal polyps 90%. If severe duodenal polyposis cancer risk of 30% at 10 years. Abdominal desmoid tumours. MYH associated polyposis Biallelic mutation of mut Y human homologue (MYH) on chromosome 1p, recessive Multiple colonic polyps Later onset right sided cancers more common than in FAP 100% cancer risk by age 60 Once identified resection and ileoanal pouch reconstruction is recommended Attenuated phenotype - regular colonoscopy Duodenal polyposis in 30% Associated with increased risk of breast cancer (self examination) Peutz -Jeghers syndrome STK11 (LKB1) mutation on chromosome 19 in some (but not all) cases, dominant Multiple benign intestinal hamartomas Episodic obstruction and intussceception Increased risk of GI cancers (colorectal cancer 20%, gastric 5%) Increased risk of breast, ovarian, cervical pancreatic and testicular cancers Annual examination Pan intestinal endoscopy every 2-3 years Malignancies at other sites Classical pigmentation pattern Cowden disease Mutation of PTEN gene on chromosome 10q22, dominant Macrocephaly Multiple intestinal hamartomas Multiple trichilemmomas 89% risk of cancer at any site 16% risk of colorectal cancer Targeted individualised screening Breast cancer (81% risk) Thyroid cancer and non toxic goitre Uterine cancer HNPCC (Lynch syndrome) Germline mutations of DNA mismatch repair genes Colo rectal cancer 30-70% Endometrial cancer 30-70% Gastric cancer 5-10% Scanty colonic polyps may be present Colonic tumours likely to be right sided and mucinous Colonoscopy every 1-2 years from age 25 Consideration of prophylactic surgery Extra colonic surveillance recommended Extra colonic cancers

Answer 1264

The anterior scalene muscle is an important anatomical landmark and separates the subclavian vein (anterior) from the subclavian artery (posterior). Scalene muscles The 3 paired muscles are: Scalenus anterior: Elevate 1st rib and laterally flex the neck to same side Scalenus medius: Same action as scalenus anterior Scalenus posterior: Elevate 2nd rib and tilt the cervical spine Innervation Spinal nerves C4-6 Origin Transverse processes C2 to C7 Insertion First and second ribs Important relations The brachial plexus and subclavian artery pass between the anterior and middle scalenes through a space called the scalene hiatus/fissure. The subclavian vein and phrenic nerve pass anteriorly to the anterior scalene as it crosses over the first rib. Thoracic outlet syndrome The scalenes are at risk of adhering to the fascia surrounding the brachial plexus or shortening causing compression of the brachial plexus when it passes between the clavicle and 1st rib causing thoracic outlet syndrome.

Answer 1265

Perthes disease should be suspected in boys over 4 years old presenting with a limp. Early disease can be missed on x-ray. An MRI will often demonstrate areas of hypoperfusion and subtle changes that allow for earlier diagnosis. A bone scan is an alternative option. Paediatric orthopaedics Diagnosis Mode of presentation Treatment Radiology Developmental dysplasia of the hip Usually diagnosed in infancy by screening tests. May be bilateral, when disease is unilateral there may be leg length inequality. As disease progresses child may limp and then early onset arthritis. More common in extended breech babies. Splints and harnesses or traction. In later years osteotomy and hip realignment procedures may be needed. In arthritis a joint replacement may be needed. However, this is best deferred if possible as it will almost certainly require revision Initially no obvious change on plain films and USS gives best resolution until 3 months of age. On plain films Shentons line should form a smooth arc Perthes Disease Hip pain (may be referred to the knee) usually occurring between 5 and 12 years of age. Bilateral disease in 20%. Remove pressure from joint to allow normal development. Physiotherapy. Usually self-limiting if diagnosed and treated promptly. X-rays will show flattened femoral head. Eventually in untreated cases the femoral head will fragment. Slipped upper femoral epiphysis Typically seen in obese male adolescents. Pain is often referred to the knee. Limitation to internal rotation is usually seen. Knee pain is usually present 2 months prior to hip slipping. Bilateral in 20%. Bed rest and non-weight bearing. Aim to avoid avascular necrosis. If severe slippage or risk of it occurring then percutaneous pinning of the hip may be required. X-rays will show the femoral head displaced and falling inferolaterally (like a melting ice cream cone) The Southwick angle gives indication of disease severity

Answer 1266

The foramen spinosum (which transmits the middle meningeal artery and vein) lies in the sphenoid bone. Foramina of the base of the skull Foramen Location Contents Foramen ovale Sphenoid bone Otic ganglion V3 (Mandibular nerve:3rd branch of trigeminal) Accessory meningeal artery Lesser petrosal nerve Emissary veins Foramen spinosum Sphenoid bone Middle meningeal artery Meningeal branch of the Mandibular nerve Foramen rotundum Sphenoid bone Maxillary nerve (V2) Foramen lacerum/ carotid canal Located between the sphenoid, the apex of the petrous temporal and the basilar part of the occipital Base of the medial pterygoid plate. Internal carotid artery* Nerve and artery of the pterygoid canal Jugular foramen Temporal bone Anterior: inferior petrosal sinus Intermediate: glossopharyngeal, vagus, and accessory nerves. Posterior: sigmoid sinus (becoming the internal jugular vein) and some meningeal branches from the occipital and ascending pharyngeal arteries. Foramen magnum Occipital bone Anterior and posterior spinal arteries Vertebral arteries Medulla oblongata Stylomastoid foramen Temporal bone Stylomastoid artery Facial nerve Superior orbital fissure Sphenoid bone Oculomotor nerve (III) Recurrent meningeal artery Trochlear nerve (IV) Lacrimal, frontal and nasociliary branches of opthalmic nerve (V1) Abducent nerve (VI) Superior ophthalmic vein *= In life the foramen lacerum is occluded by a cartilagenous plug. The ICA initially passes into the carotid canal which ascends superomedially to enter the cranial cavity through the foramen lacerum.

Answer 1267

Staphylococcus aureus is the commonest cause of lactational mastitis. Mastitis Mastitis refers to infection within the breast, the commonest variant, lactational mastitis is related to breast feeding and occurs as a result of inoculation of the breast tissue (which may have breaks in epithelial integrity) with staphylococcus aureus that is carried in the infants oropharynx. The result is a tender erythematous breast. Fever is common. Treatment is usually with encouraging breast drainage (e.g. breast pumps) and antibiotics. Imaging with USS will demonstrate any underlying abscess. The preferred treatment for this complication is percutaneous aspiration where this is possible. Where the overlying epithelium is non viable, debridement may be needed, there is a risk that this may be complicated by the development of a subsequent mammary duct fistula.

Answer 1268

This patient has diplophonia which causes a gargling sound. This is associated with dysphagia. This can also be caused by a vagus nerve lesion, but the recurrent laryngeal nerve is more at risk of damage. In bilateral injury, the airway is at risk and therefore this takes precedence. Voice production There are 2 main nerves involved: Superior laryngeal nerve (SLN) Innervates the cricothyroid muscle Since the cricothyroid muscle is involved in adjusting the tension of the vocal fold for high notes during singing, SLN paresis and paralysis result in: a. Abnormalities in pitch b. Inability to sing with smooth change to each higher note (glissando or pitch glide) Recurrent laryngeal nerve (RLN)/Inferior laryngeal nerve Innervates intrinsic larynx muscles a. Opening vocal folds (as in breathing, coughing) b. Closing vocal folds for vocal fold vibration during voice use c. Closing vocal folds during swallowing

Answer 1269

Waterhouse - Friderichsen syndrome is defined as adrenal gland failure due to bleeding into the adrenal glands. It is caused by severe bacterial infection (most commonly the meningococcus Neisseria meningitidis). The bacterial infection leads to massive hemorrhage into one or (usually) both adrenal glands. It is characterised by overwhelming bacterial infection meningococcemia leading to massive blood invasion, organ failure, coma, haemodynamic shock, disseminated intravascular coagulation with widespread purpura, rapidly developing adrenocortical insufficiency and death. Note the scenarios relating to spontaneous bleeding related to a unilateral process and cannot therefore be the correct answer. Phaeochromocytoma and adrenal lesions Phaeochromocytoma Neuroendocrine tumour of the chromaffin cells of the adrenal medulla. Hypertension and hyperglycaemia are often found. 10% of cases are bilateral. 10% occur in children. 11% are malignant (higher when tumour is located outside the adrenal). 10% will not be hypertensive. Familial cases are usually linked to the Multiple endocrine neoplasia syndromes (considered under its own heading). Most tumours are unilateral (often right sided) and smaller than 10cm. Diagnosis Urine and plasma metanephrine levels. CT and MRI scanning are both used to localise the lesion. Treatment Patients require medical therapy first. An irreversible alpha adrenoreceptor blocker should be given, although minority may prefer reversible blockade(1). Labetolol may be co-administered for cardiac chronotropic control. Isolated beta blockade should not be considered as it will lead to unopposed alpha activity. These patients are often volume depleted and will often require moderate volumes of intra venous normal saline perioperatively. Once medically optimised the phaeochromocytoma should be removed. Most adrenalectomies can now be performed using a laparoscopic approach(2). The adrenals are highly vascular structures and removal can be complicated by catastrophic haemorrhage in the hands of the inexperienced. This is particularly true of right sided resections where the IVC is perilously close. Should the IVC be damaged a laparotomy will be necessary and the defect enclosed within a Satinsky style vascular clamp and the defect closed with prolene sutures. Attempting to interfere with the IVC using any instruments other than vascular clamps will result in vessel trauma and make a bad situation much worse. Incidental adrenal lesions Adrenal lesions may be identified on CT scanning performed for other reasons(3). Factors suggesting benign disease on CT include(4): Size less than 3cm Homogeneous texture Lipid rich tissue Thin wall to lesion All patients with incidental lesions should be managed jointly with an endocrinologist and full work up as described above. Patients with functioning lesions or those with adverse radiological features (Particularly size >3cm) should proceed to surgery. References 1. Weingarten TN, Cata JP, O'Hara JF, Prybilla DJ, Pike TL, Thompson GB, et al. Comparison of two preoperative medical management strategies for laparoscopic resection of pheochromocytoma. Urology. 2010 Aug;76(2):508 e6-11. 2. Nguyen PH, Keller JE, Novitsky YW, Heniford BT, Kercher KW. Laparoscopic approach to adrenalectomy: review of perioperative outcomes in a single center. Am Surg. 2011 May;77(5):592-6. 3. Ng VW, Ma RC, So WY, Choi KC, Kong AP, Cockram CS, et al. Evaluation of functional and malignant adrenal incidentalomas. Arch Intern Med. 2010 Dec 13;170(22):2017-20. 4. Muth A, Hammarstedt L, Hellstrom M, Sigurjonsdottir HA, Almqvist E, Wangberg B. Cohort study of patients with adrenal lesions discovered incidentally. Br J Surg. 2011 May 27.

Answer 1270

Accessory spleens - 10% population - 1 cm size - locations: hilum of the spleen, tail of the pancreas, along the splenic vessels, in the gastrosplenic ligament, the splenorenal ligament, the walls of the stomach or intestines, the greater omentum, the mesentery, the gonads Spleen The spleen is located in the left upper quadrant of the abdomen and its size can vary depending upon the amount of blood it contains. The typical adult spleen is 12.5cm long and 7.5cm wide. The usual weight of the adult spleen is 150g. The exact position of the spleen can vary with respiratory activity, posture and the state of surrounding viscera. It usually lies obliquely with its long axis aligned to the 9th, 10th and 11th ribs. It is separated from these ribs by both diaphragm and pleural cavity. The normal spleen is not palpable. The shape of the spleen is influenced by the state of the colon and stomach. Gastric distension will cause the spleen to resemble the shape of an orange segment. Colonic distension will cause it to become more tetrahedral. The spleen is almost entirely covered by peritoneum, which adheres firmly to its capsule. Recesses of the greater sac separate it from the stomach and kidney. It develops from the upper dorsal mesogastrium, remaining connected to the posterior abdominal wall and stomach by two folds of peritoneum; the lienorenal ligament and gastrosplenic ligament. The lienorenal ligament is derived from peritoneum where the wall of the general peritoneum meets the omental bursa between the left kidney and spleen; the splenic vessels lie in its layers. The gastrosplenic ligament also has two layers, formed by the meeting of the walls of the greater sac and omental bursa between spleen and stomach, the short gastric and left gastroepiploic branches of the splenic artery pass in its layers. Laterally, the spleen is in contact with the phrenicocolic ligament. Relations Superiorly Diaphragm Anteriorly Gastric impression Posteriorly Kidney Inferiorly Colon Hilum Tail of pancreas and splenic vessels (splenic artery divides here, branches pass to the white pulp transporting plasma) Contents White pulp Immune function. Contains central trabecular artery. The germinal centres are supplied by arterioles called penicilliary radicles. Red pulp Filters abnormal red blood cells. Function Filtration of abnormal blood cells and foreign bodies such as bacteria. Immunity: IgM. Production of properdin, and tuftsin which help target fungi and bacteria for phagocytosis. Haematopoiesis: up to 5th month gestation or in haematological disorders. Pooling: storage of 40% platelets. Iron reutilisation Storage monocytes Disorders of the spleen Massive splenomegaly Myelofibrosis Chronic myeloid leukaemia Visceral leishmaniasis (kala-azar) Malaria Gaucher's syndrome Other causes (as above plus) Portal hypertension e.g. secondary to cirrhosis Lymphoproliferative disease e.g. CLL, Hodgkin's Haemolytic anaemia Infection: hepatitis, glandular fever Infective endocarditis Sickle-cell*, thalassaemia Rheumatoid arthritis (Felty's syndrome) *the majority of adult patients with sickle-cell will have an atrophied spleen due to repeated infarction

Answer 1271

E- FEV1/FVC is normal or >80% in restrictive lung disease such as pulmonary fibrosis. The ratio is reduced in obstructive airways disease. The functional residual capacity, residual volume and the total lung capacity cannot be measured with spirometry. They can only be measured by helium dilution. The vital capacity is reduced in: 1. Pulmonary fibrosis/infiltration/oedema/effusions 2. Weak respiratory muscles e.g. MG, GBS, myopathies 3. Skeletal abnormalities e.g. chest wall abnormalities Definitions Tidal volume (TV) Is the volume of air inspired and expired during each ventilatory cycle at rest. It is normally 500mls in males and 340mls in females. Inspiratory reserve volume (IRV) Is the maximum volume of air that can be forcibly inhaled following a normal inspiration. 3000mls. Expiratory reserve volume (ERV) Is the maximum volume of air that can be forcibly exhaled following a normal expiration. 1000mls. Residual volume (RV) Is that volume of air remaining in the lungs after a maximal expiration. RV = FRC - ERV. 1500mls. Functional residual capacity (FRC) Is the volume of air remaining in the lungs at the end of a normal expiration. FRC = RV + ERV. 2500mls. Vital capacity (VC) Is the maximal volume of air that can be forcibly exhaled after a maximal inspiration. VC = TV + IRV + ERV. 4500mls in males, 3500mls in females. Total lung capacity (TLC) Is the volume of air in the lungs at the end of a maximal inspiration. TLC = FRC + TV + IRV = VC + RV. 5500-6000mls. Forced vital capacity (FVC) The volume of air that can be maximally forcefully exhaled.

Answer 1272

Lesions before optic chiasm: Monocular vision loss = Optic nerve lesion Bitemporal hemianopia = Optic chiasm lesion Lesions after the optic chiasm: Homonymous hemianopia = Optic tract lesion Upper quadranopia = Temporal lobe lesion Lower quadranopia = Parietal lobe lesion Unfortunately we thought as surgeons we could forget about visual field defects! However the college seem to like them. Remember a homonymous hemianopia is indicative of an optic tract lesion. Parietal lobe lesions tend to cause inferior quadranopias and there is a bitemporal hemianopia with optic chiasm lesion or pituitary tumours. Visual field defects left homonymous hemianopia means visual field defect to the left, i.e. Lesion of right optic tract homonymous quadrantanopias: PITS (Parietal-Inferior, Temporal-Superior) incongruous defects = optic tract lesion; congruous defects = optic radiation lesion or occipital cortex Homonymous hemianopia Incongruous defects: lesion of optic tract Congruous defects: lesion of optic radiation or occipital cortex Macula sparing: lesion of occipital cortex Homonymous quadrantanopias Superior: lesion of temporal lobe Inferior: lesion of parietal lobe Mnemonic = PITS (Parietal-Inferior, Temporal-Superior) Bitemporal hemianopia Lesion of optic chiasm Upper quadrant defect > lower quadrant defect = inferior chiasmal compression, commonly a pituitary tumour Lower quadrant defect > upper quadrant defect = superior chiasmal compression, commonly a craniopharyngioma

Answer 1273

Filariasis is caused by the nematode Wuchereria bancrofti, which is mainly spread by mosquito. The oedema can be gross leading to elephantitis. Treatment is with diethylcarbamazine. Lymphoedema - Due to impaired lymphatic drainage in the presence of normal capillary function. Lymphoedema causes the accumulation of protein rich fluid, subdermal fibrosis and dermal thickening. Characteristically fluid is confined to the epifascial space (skin and subcutaneous tissues); muscle compartments are free of oedema. It involves the foot, unlike other forms of oedema. There may be a 'buffalo hump' on the dorsum of the foot and the skin cannot be pinched due to subcutaneous fibrosis. Causes of lymphoedema Primary Congenital < 1 year: sporadic, Milroy's disease Onset 1-35 years: sporadic, Meige's disease > 35 years: Tarda Secondary Bacterial/fungal/parasitic infection (filariasis) Lymphatic malignancy Radiotherapy to lymph nodes Surgical resection of lymph nodes DVT Thrombophlebitis Indications for surgery Marked disability or deformity from limb swelling Lymphoedema caused by proximal lymphatic obstruction with patent distal lymphatics suitable for a lymphatic drainage procedure Lymphocutaneous fistulae and megalymphatics Procedures Homans operation Reduction procedure with preservation of overlying skin (which must be in good condition). Skin flaps are raised and the underlying tissue excised. Limb circumference typically reduced by a third. Charles operation All skin and subcutaneous tissue around the calf are excised down to the deep fascia. Split skin grafts are placed over the site. May be performed if overlying skin is not in good condition. Larger reduction in size than with Homans procedure. Lymphovenous anastamosis Identifiable lymphatics are anastomosed to sub dermal venules. Usually indicated in 2% of patients with proximal lymphatic obstruction and normal distal lymphatics.

Answer 1274

This woman has a diagnosis of carpal tunnel syndrome. Rheumatological disorders are a common cause. Clinical examination should focus on identifying stigmata of rheumatoid arthritis, such as rheumatoid nodules, vasculitic lesions and metacarpophalangeal joint arthritis. Carpal tunnel syndrome Carpal tunnel syndrome is caused by compression of median nerve in the carpal tunnel History pain/pins and needles in thumb, index, middle finger e.g. at night patient flicks hand to obtain relief Examination weakness of thumb abduction wasting of thenar eminence (NOT hypothenar) Tinel's sign: tapping causes paraesthesia Phalen's sign: flexion of wrist causes symptoms Causes of carpal tunnel syndrome MEDIAN TRAP Mnemonic Myxoedema Edema premenstrually Diabetes Idiopathic Acromegaly Neoplasm Trauma Rheumatoid arthritis Amyloidosis Pregnancy Management Non surgical treatment Surgery May resolve spontaneously Avoid precipitants and reassurance Night-time splints Local steroid injections Complete division of the flexor retinaculum and decompression of the tunnel (successful in approximately 80% of patients)

Answer 1275

These three arteries coalesce at Littles area which is a common site of epistaxis. Nasal cavity There are two nasal cavities separated by the median nasal septum. This structure consists of septal cartilage and two bony parts: the vomer and the perpendicular plate of the ethmoid bone. Each cavity is approximately 5cm high and 7cm long, from the nares anteriorly to the choanae posteriorly. The lateral walls of each cavity are mainly made up of the maxilla. However, the lacrimal, ethmoid and palatine bones also contribute. The ethmoid gives rise to the two upper protrusions from the lateral walls, the superior and middle conchae. The inferior concha is a separate bone. Above the superior concha lies the sphenoethmoidal recess. The spaces inferior to conchae are the superior, middle and inferior meatus. The structures draining into each space are shown below: Sphenoethmoidal recess Sphenoidal sinus Superior meatus Posterior ethmoidal sinus Middle meatus Frontal sinus, maxillary sinus ,anterior and middle ethmoidal sinus Inferior meatus Nasolacrimal duct The main arterial supply to the septum and lateral walls is the sphenopalatine artery, a branch of the maxillary artery. The olfactory nerve conveys special sensation. Common sensation from the nasal mucosa is conveyed by the trigeminal nerve.

Answer 1276

The palmar interossei are supplied by the ulnar nerve. Which lies inferiorly and is therefore less likely to be injured. Brachial plexus The brachial plexus extends from the neck to the axilla. It is formed by the ventral rami of the fifth to the eighth cervical nerves with the ascending part of the first thoracic nerve. Location of the plexus The ventral rami which form the plexus enter the lower part of the posterior triangle of the neck in series with the ventral rami of the cervical plexus. The second part of the subclavian artery lies immediately anterior to the lower two rami. The upper three rami intermingle and pass inferolaterally towards the axilla and subclavian artery. They are enclosed within an extension of the prevertebral fascia. In the neck the plexus lies deep to platysma, the supraclavicular nerves, inferior belly of omohyoid and the transverse cervical artery. It then passes deep to the clavicle and the suprascapular vessels, to enter the axilla, and thence surround the second part of the axillary artery Composition of the plexus Ventral rami, the roots of the plexus, lie between scalenus medius and anterior. As they enter the posterior triangle, the upper two (C5,6) and lower two (C8, T1) roots of the plexus unite to form the upper and lower trunks of the plexus respectively. Meanwhile, C7 continues as the middle trunk. The lower trunk may groove the superior surface of the first rib posterior to the subclavian artery, and the root from the first ventral ramus is always in contact with it. Each trunk divides into ventral and dorsal divisions which are destined to supply the anterior (flexor) and posterior (extensor) parts of the upper limb. The cords of the plexus are formed in the axilla. The dorsal divisions unite to form the posterior cord (C5-8). The ventral divisions of the upper and middle trunks unite to form the lateral cord (C5-7), while the ventral divisions of the lower trunk continues as the medial cord (C8-T1). The cords are named according to their relationship to the axillary artery. Each cord terminates by dividing into two main branches at the beginning of the third part of the artery. Sympathetic communications The fifth and sixth cervical ventral rami receive grey rami communicantes from the middle cervical ganglion, while the two or more grey rami communicantes pass from the inferior cervical ganglion to the seventh and eighth cervical ventral rami. The first thoracic ventral ramus receives its grey ramus from the cervicothoracic ganglion. Its for this reason that inferior plexus injury can be complicated by a Horners syndrome. Summary Origin Anterior rami of C5 to T1 Sections of the plexus Roots, trunks, divisions, cords, branches Mnemonic:Real Teenagers Drink Cold Beer Roots Located in the posterior triangle Pass between scalenus anterior and medius Trunks Located posterior to middle third of clavicle Upper and middle trunks related superiorly to the subclavian artery Lower trunk passes over 1st rib posterior to the subclavian artery Divisions Apex of axilla Cords Related to axillary artery

Answer 1277

Barium meal appearances of linitis plastica: Due to the increased rigidity of the wall, the stomach cannot be adequately distended, with only a narrow lumen identified. The normal mucosal fold pattern is absent, either distorted, thickened or nodular. The Lauren classification describes a diffuse type of adenocarcinoma (Linitis plastica type lesion) and an intestinal type. The diffuse type is often deeply infiltrative and may be difficult to detect on endoscopy. Barium meal appearances can be characteristic. Gastric cancer Overview There are 700,000 new cases of gastric cancer worldwide each year. It is most common in Japan and less common in western countries. It is more common in men and incidence rises with increasing age. The exact cause of many sporadic cancer is not known, however, familial cases do occur in HNPCC families. In addition, smoking and smoked or preserved foods increase the risk. Japanese migrants retain their increased risk (decreased in subsequent generations). The distribution of the disease in western countries is changing towards a more proximal location (perhaps due to rising obesity). Pathology There is some evidence of support a stepwise progression of the disease through intestinal metaplasia progressing to atrophic gastritis and subsequent dysplasia, through to cancer. The favoured staging system is TNM. The risk of lymph node involvement is related to size and depth of invasion; early cancers confined to submucosa have a 20% incidence of lymph node metastasis. Tumours of the gastro-oesophageal junction are classified as below: Type 1 True oesophageal cancers and may be associated with Barrett's oesophagus. Type 2 Carcinoma of the cardia, arising from cardiac type epithelium or short segments with intestinal metaplasia at the oesophagogastric junction. Type 3 Sub cardial cancers that spread across the junction. Involve similar nodal stations to gastric cancer. Groups for close endoscopic monitoring Intestinal metaplasia of columnar type Atrophic gastritis Low to medium grade dysplasia Patients who have previously undergone resections for benign peptic ulcer disease (except highly selective vagotomy). Referral to endoscopy Patients of any age with dyspepsia and any of the following Patients without dyspepsia Worsening dyspepsia Chronic gastrointestinal bleeding Dysphagia Barretts oesophagus Dysphagia Unexplained abdominal pain or weight loss Intestinal metaplasia Weight loss Vomiting Dysplasia Iron deficiency anaemia Upper abdominal mass Atrophic gastritis Upper abdominal mass Jaundice Patient aged over 55 years with unexplained or persistent dyspepsia Staging CT scanning of the chest abdomen and pelvis is the routine first line staging investigation in most centres. Laparoscopy to identify occult peritoneal disease PET CT (particularly for junctional tumours) Treatment Proximally sited disease greater than 5-10cm from the OG junction may be treated by sub total gastrectomy Total gastrectomy if tumour is <5cm from OG junction For type 2 junctional tumours (extending into oesophagus) oesophagogastrectomy is usual Endoscopic sub mucosal resection may play a role in early gastric cancer confined to the mucosa and perhaps the sub mucosa (this is debated) Lymphadenectomy should be performed. A D2 lymphadenectomy is widely advocated by the Japanese, the survival advantages of extended lymphadenectomy have been debated. However, the overall recommendation is that a D2 nodal dissection be undertaken. Most patients will receive chemotherapy either pre or post operatively. Prognosis UK Data Disease extent Percentage 5 year survival All RO resections 54% Early gastric cancer 91% Stage 1 87% Stage 2 65% Stage 3 18% Operative procedure Total Gastrectomy , lymphadenectomy and Roux en Y anastomosis General anaesthesia Prophylactic intravenous antibiotics Incision: Rooftop. Perform a thorough laparotomy to identify any occult disease. Mobilise the left lobe of the liver off the diaphragm and place a large pack over it. Insert a large self retaining retractor e.g. omnitract or Balfour (take time with this, the set up should be perfect). Pack the small bowel away. Begin by mobilising the omentum off the transverse colon. Proceed to detach the short gastric vessels. Mobilise the pylorus and divide it at least 2cm distally using a linear cutter stapling device. Continue the dissection into the lesser sac taking the lesser omentum and left gastric artery flush at its origin. The lymph nodes should be removed en bloc with the specimen where possible. Place 2 stay sutures either side of the distal oesophagus. Ask the anaesthetist to pull back on the nasogastric tube. Divide the distal oesophagus and remove the stomach. The oesphago jejunal anastomosis should be constructed. Identify the DJ flexure and bring a loop of jejunum up to the oesophagus (to check it will reach). Divide the jejunum at this point. Bring the divided jejunum either retrocolic or antecolic to the oesophagus. Anastamose the oesophagus to the jejunum, using either interrupted 3/0 vicryl or a stapling device. Then create the remainder of the Roux en Y reconstruction distally. Place a jejunostomy feeding tube. Wash out the abdomen and insert drains (usually the anastomosis and duodenal stump). Help the anaesthetist insert the nasogastric tube (carefully!) Close the abdomen and skin. Enteral feeding may commence on the first post-operative day. However, most surgeons will leave patients on free NG drainage for several days and keep them nil by mouth.

Answer 1278

The upper ureter drains to the para-aortic nodes, the lower ureter drains to the common iliac nodes. Ureter 25-35 cm long Muscular tube lined by transitional epithelium Surrounded by thick muscular coat. Becomes 3 muscular layers as it crosses the bony pelvis Retroperitoneal structure overlying transverse processes L2-L5 Lies anterior to bifurcation of iliac vessels Blood supply is segmental; renal artery, aortic branches, gonadal branches, common iliac and internal iliac Lies beneath the uterine artery

Answer 1279

A- Multiple duct pathology= total duct excision Single duct pathology= microdochectomy This woman has troublesome duct ectasia and total duct excision is warranted. Nipple discharge Causes of nipple discharge Physiological During breast feeding Galactorrhoea Commonest cause may be response to emotional events, drugs such as histamine receptor antagonists are also implicated Hyperprolactinaemia Commonest type of pituitary tumour Microadenomas <1cm in diameter Macroadenomas >1cm in diameter Pressure on optic chiasm may cause bitemporal hemianopia Mammary duct ectasia Dilatation breast ducts. Most common in menopausal women Discharge typically thick and green in colour Most common in smokers Carcinoma Often blood stained May be underlying mass or axillary lymphadenopathy Intraductal papilloma Commoner in younger patients May cause blood stained discharge There is usually no palpable lump Assessment of patients Examine breast and determine whether there is mass lesion present All mass lesions should undergo Triple assessment. Reporting of investigations Where a mass lesion is suspected or investigations are requested these are prefixed using a system that denotes the investigation type e.g. M for mammography, followed by a numerical code as shown below: 1 No abnormality 2 Abnormality with benign features 3 Indeterminate probably benign 4 Indeterminate probably malignant 5 Malignant Management of non malignant nipple discharge Exclude endocrine disease Nipple cytology unhelpful Smoking cessation advice for duct ectasia For duct ectasia with severe symptoms, total duct excision may be warranted.

Answer 1280

As there is no associated vascular injury the patient may be suitable for debridement of the area and external fixation. If debridement leaves a tissue defect then plastic surgical repair will be needed at a later stage. With open fractures, its best not to place intramedullary metalwork as this may become infected. Fracture management Bony injury resulting in a fracture may arise from trauma (excessive forces applied to bone), stress related (repetitive low velocity injury) or pathological (abnormal bone which fractures during normal use of following minimal trauma) Diagnosis involves not just evaluating the fracture ; such as site and type of injury but also other associated injuries and distal neurovascular deficits. This may entail not just clinical examination but radiographs of proximal and distal joints. When assessing x-rays it is important to assess for changes in length of the bone, the angulation of the distal bone, rotational effects, presence of material such as glass. Fracture types Fracture type Description Oblique fracture Fracture lies obliquely to long axis of bone Comminuted fracture >2 fragments Segmental fracture More than one fracture along a bone Transverse fracture Perpendicular to long axis of bone Spiral fracture Severe oblique fracture with rotation along long axis of bone Open Vs Closed It is also important to distinguish open from closed injuries. The most common classification system for open fractures is the Gustilo and Anderson classification system (given below): Grade Injury 1 Low energy wound <1cm 2 Greater than 1cm wound with moderate soft tissue damage 3 High energy wound > 10cm with extensive soft tissue damage 3 A (sub group of 3) Adequate soft tissue coverage 3 B (sub group of 3) Inadequate soft tissue coverage 3 C (sub group of 3) Associated arterial injury Key points in management of fractures Immobilise the fracture including the proximal and distal joints Carefully monitor and document neurovascular status, particularly following reduction and immobilisation Manage infection including tetanus prophylaxis IV broad spectrum antibiotics for open injuries As a general principle all open fractures should be thoroughly debrided ( and internal fixation devices avoided or used with extreme caution) Open fractures constitute an emergency and should be debrided and lavaged within 6 hours of injury

Answer 1281

Study design: evidence and recommendations Levels of evidence I - evidence from meta-analysis of randomised controlled trials II - evidence from at least one well designed controlled trial which is not randomised III - evidence from correlation and comparative studies or use of historical controls IV - evidence from case series V - Expert opinion or founded on basic principles Knowledge of the sub groups of the levels of evidence are not routinely tested in MRCS Part A. Grading of recommendation Grade A - based on evidence from at least one randomised controlled trial (i.e. Ia or Ib) Grade B - based on evidence from non-randomised controlled trials (i.e. IIa, IIb or III) Grade C - based on evidence from a panel of experts (i.e. IV)

Answer 1282

The extensor muscles are innervated by the radial nerve. Ulnar nerve Origin C8, T1 Supplies (no muscles in the upper arm) Flexor carpi ulnaris Flexor digitorum profundus Flexor digiti minimi Abductor digiti minimi Opponens digiti minimi Adductor pollicis Interossei muscle Third and fourth lumbricals Palmaris brevis Path Posteromedial aspect of upper arm to flexor compartment of forearm, then along the ulnar. Passes beneath the flexor carpi ulnaris muscle, then superficially over the flexor retinaculum into the palm of the hand. Branches Branch Supplies Muscular branch Flexor carpi ulnaris Medial half of the flexor digitorum profundus Palmar cutaneous branch (Arises near the middle of the forearm) Skin on the medial part of the palm Dorsal cutaneous branch Dorsal surface of the medial part of the hand Superficial branch Cutaneous fibres to the anterior surfaces of the medial one and one-half digits Deep branch Hypothenar muscles All the interosseous muscles Third and fourth lumbricals Adductor pollicis Medial head of the flexor pollicis brevis Effects of injury Damage at the wrist Wasting and paralysis of intrinsic hand muscles (claw hand) Wasting and paralysis of hypothenar muscles Loss of sensation medial 1 and half fingers Damage at the elbow Radial deviation of the wrist Clawing less in 4th and 5th digits

Answer 1283

Oesophageal SCC can be managed with radical chemoradiotherapy. Radiotherapy alone is not usually curative. Segmental resection of the upper oesophagus is not practiced. An Ivor Lewis oesophagectomy would only address distal disease. Oesophageal cancer - treatment Treatments for SCC's and adenocarcinomas of the oesophagus differ. This is primarily due to the positive outcomes that are observed when localised SCC's (particularly of the proximal oesophagus) are treated with radical chemoradiotherapy (obviating the need for surgery). Only those patients whose staging investigations are negative for metastatic disease should be considered for surgery. Surgical options Endoscopic mucosal resection Treatment for early localised adenocarcinoma of the distal oesophagus. Survival mirrors that of surgical resection for Tis and T1 disease Transhiatal oeosphagectomy Most commonly used for junctional (type II) (1) tumours where limited thoracic oesophageal resection is required. Less morbidity than two field oesophagectomy Ivor Lewis oesophagectomy Two stage approach for middle and distal tumours. Very commonly performed, intrathoracic anastomosis will result in mediastinitis in event of anastomotic leak. Lower incidence of recurrent laryngeal nerve injury McKeown oesophagectomy Three field approach, may be useful for proximal tumours. Anastomotic leakage is less serious. Higher incidence of recurrent laryngeal nerve injury Neoadjuvent and adjuvent treatment Neoadjuvent radiotherapy alone prior to resection confers little benefit and is not routinely performed (2) Preoperative chemotherapy is associated with a survival advantage (OE02 trial) Peri operative (pre and post operative) chemotherapy confers a survival advantage in junctional tumours Post operative chemotherapy is not generally recommended following oesophageal resections outside clinical trials Palliation strategies Combination chemotherapy improves quality of life and survival in non operable disease (3) Trastuzumab may improve survival in patients with HER 2 positive tumours Oesophageal intubation with self expanding metal stents is the treatment of choice in patients with occluding tumours >2cm from the cricopharyngeus Covered metal stents are useful in cases of malignant fistulas Laser therapy and argon plasma coagulation may be useful as therapies for tumour overgrowth and bleeding Photodynamic therapy and ethanol injections confer little benefit and should not be routinely used References 1. Hulscher JB, van Sandick JW, de Boer AG, et al. Extended transthoracic resection compared with limited transhiatal resection for adenocarcinoma of the esophagus. N Engl J Med 2002;347:1662-9 2. Deng HY, Wang WP, Wang YC, Hu WP, Ni PZ, Lin YD, Chen LQ. Neoadjuvant chemoradiotherapy or chemotherapy? A comprehensive systematic review and meta-analysis of the options for neoadjuvant therapy for treating oesophageal cancer. Eur J Cardiothorac Surg. 2017 Mar 1;51(3):421-431. doi: 10.1093/ejcts/ezw315. 3.Khin MO, Bromham N, Harrison M, Eadon H. Assessment and management of oesophago-gastric cancer: summary of NICE guidance. BMJ. 2018 Jan 29;360:k213. doi: 10.1136/bmj.k213

Answer 1284

Remember L1 ('left one') is the level of the hilum of the left kidney Renal anatomy Each kidney is about 11cm long, 5cm wide and 3cm thick. They are located in a deep gutter alongside the projecting vertebral bodies, on the anterior surface of psoas major. In most cases the left kidney lies approximately 1.5cm higher than the right. The upper pole of both kidneys approximates with the 11th rib (beware pneumothorax during nephrectomy). On the left hand side the hilum is located at the L1 vertebral level and the right kidney at level L1-2. The lower border of the kidneys is usually alongside L3. The table below shows the anatomical relations of the kidneys: Relations Relations Right Kidney Left Kidney Posterior Quadratus lumborum, diaphragm, psoas major, transversus abdominis Quadratus lumborum, diaphragm, psoas major, transversus abdominis Anterior Hepatic flexure of colon Stomach, Pancreatic tail Superior Liver, adrenal gland Spleen, adrenal gland Fascial covering Each kidney and suprarenal gland is enclosed within a common layer of investing fascia, derived from the transversalis fascia. It is divided into anterior and posterior layers (Gerotas fascia). Renal structure Kidneys are surrounded by an outer cortex and an inner medulla which usually contains between 6 and 10 pyramidal structures. The papilla marks the innermost apex of these. They terminate at the renal pelvis, into the ureter. Lying in a hollow within the kidney is the renal sinus. This contains: 1. Branches of the renal artery 2. Tributaries of the renal vein 3. Major and minor calyces's 4. Fat Structures at the renal hilum The renal vein lies most anteriorly, then renal artery (it is an end artery) and the ureter lies most posterior.

Answer 1285

The cephalic vein is superficially located in the upper limb and overlies most the fascial planes. It pierces the coracoid membrane (continuation of the clavipectoral fascia) to terminate in the axillary vein. It lies anterolaterally to biceps. Cephalic vein Path Dorsal venous arch drains laterally into the cephalic vein Crosses the anatomical snuffbox and travels laterally up the arm At the antecubital fossa connected to the basilic vein by the median cubital vein Pierces deep fascia of deltopectoral groove to join axillary vein

Answer 1286

Haematoceles develop over minutes/ hours and occur after the event This is a secondary hydrocele which occurs in patients aged 20-40 years. It develops over days/ weeks and there may not be a tense swelling. The underlying testis is NOT palpated therefore indicating a hydrocele. Causes include trauma, infection and tumour. Scrotal swelling Differential diagnosis Inguinal hernia If inguinoscrotal swelling; cannot 'get above it' on examination Cough impulse may be present May be reducible Testicular tumours Often discrete testicular nodule (may have associated hydrocele) Symptoms of metastatic disease may be present USS scrotum and serum AFP and β HCG required Acute epididymo-orchitis Often history of dysuria and urethral discharge Swelling may be tender and eased by elevating testis Most cases due to Chlamydia Infections with other gram negative organisms may be associated with underlying structural abnormality Epididymal cysts Single or multiple cysts May contain clear or opalescent fluid (spermatoceles) Usually occur over 40 years of age Painless Lie above and behind testis It is usually possible to 'get above the lump' on examination Hydrocele Non painful, soft fluctuant swelling Often possible to 'get above it' on examination Usually contain clear fluid Will often transilluminate May be presenting feature of testicular cancer in young men Testicular torsion Severe, sudden onset testicular pain Risk factors include abnormal testicular lie Typically affects adolescents and young males On examination testis is tender and pain not eased by elevation Urgent surgery is indicated, the contra lateral testis should also be fixed Varicocele Varicosities of the pampiniform plexus Typically occur on left (because testicular vein drains into renal vein) May be presenting feature of renal cell carcinoma Affected testis may be smaller and bilateral varicoceles may affect fertility Management Testicular malignancy is always treated with orchidectomy via an inguinal approach. This allows high ligation of the testicular vessels and avoids exposure of another lymphatic field to the tumour. Torsion is commonest in young teenagers and the history in older children can be difficult to elicit. Intermittent torsion is a recognised problem. The treatment is prompt surgical exploration and testicular fixation. This can be achieved using sutures or by placement of the testis in a Dartos pouch. Varicoceles are usually managed conservatively. If there are concerns about testicular function of infertility then surgery or radiological management can be considered. Epididymal cysts can be excised using a scrotal approach Hydroceles are managed differently in children where the underlying pathology is a patent processus vaginalis and therefore an inguinal approach is used in children so that the processus can be ligated. In adults a scrotal approach is preferred and the hydrocele sac excised or plicated.

Answer 1287

Rule of thirds: 1/3 multiple 1/3 small bowel 1/3 metastasize 1/3 second tumour Liver metastases are necessary for the presence of carcinoid syndrome. Carcinoid syndrome Carcinoid tumours secrete serotonin Originate in neuroendocrine cells mainly in the intestine (midgut-distal ileum/appendix) Can occur in the rectum, bronchi Hormonal symptoms mainly occur when disease spreads outside the bowel Clinical features Onset: insidious over many years Flushing face Palpitations Pulmonary valve stenosis and tricuspid regurgitation causing dyspnoea Asthma Severe diarrhoea (secretory, persists despite fasting) Investigation 5-HIAA in a 24-hour urine collection Somatostatin receptor scintigraphy CT scan Blood testing for chromogranin A Treatment Octreotide Surgical removal

Answer 1288

Atracurium is degraded by a process of ester hydrolysis. This uses non specific plasma esterases. Muscle relaxants Suxamethonium Depolarising neuromuscular blocker Inhibits action of acetylcholine at the neuromuscular junction Degraded by plasma cholinesterase and acetylcholinesterase (affected by lack of acetylcholinesterase) Fastest onset and shortest duration of action of all muscle relaxants Produces generalised muscular contraction prior to paralysis Adverse effects include hyperkalaemia, malignant hyperthermia, delayed recovery Atracurium Non depolarising neuromuscular blocking drug Duration of action usually 30-45 minutes Generalised histamine release on administration may produce facial flushing, tachycardia and hypotension Not excreted by liver or kidney, broken down in tissues by hydrolysis Reversed by neostigmine Vecuronium Non depolarising neuromuscular blocking drug Duration of action approximately 30 - 40 minutes Degraded by liver and kidney and effects prolonged in organ dysfunction Effects may be reversed by neostigmine Pancuronium Non depolarising neuromuscular blocker Onset of action approximately 2-3 minutes Duration of action up to 2 hours Effects may be partially reversed with drugs such as neostigmine

Answer 1289

Nerve supply of lateral hip rotators Piriformis: ventral rami S1, S2 Obturator internus: nerve to obturator internus Superior gemellus: nerve to obturator internus Inferior gemellus: nerve to quadratus femoris Quadrator femoris: nerve to quadrator femoris The piriformis muscle is an important anatomical landmark in the gluteal region. The following structures are closely related: Sciatic nerve Inferior gluteal artery and nerve Superior gluteal artery and nerve The medial femoral circumflex artery runs deep to quadratus femoris.

Answer 1290

Orbital apex syndrome This is an extension of superior orbital fissure syndrome and includes compression of the optic nerve passing through the optic foramen. It is indicated by features of superior orbital fissure syndrome and ipsilateral afferent pupillary defect. This type of injury will result in the orbital apex syndrome (See above). As such opthalmoplegia will be present and nystagmus cannot occur. Craniomaxillofacial injuries Craniomaxillofacial injuries in the UK are due to: Interpersonal violence (52%) Motor vehicle accidents (16%) Sporting injuries (19%) Falls (11%) Le Fort Fractures Grade Feature Le Fort 1 The fracture extends from the nasal septum to the lateral pyriform rims, travels horizontally above the teeth apices, crosses below the zygomaticomaxillary junction, and traverses the pterygomaxillary junction to interrupt the pterygoid plates. Le Fort 2 These fractures have a pyramidal shape and extend from the nasal bridge at or below the nasofrontal suture through the frontal process of the maxilla, inferolaterally through the lacrimal bones and inferior orbital floor and rim through or near the inferior orbital foramen, and inferiorly through the anterior wall of the maxillary sinus; it then travels under the zygoma, across the pterygomaxillary fissure, and through the pterygoid plates. Le Fort 3 These fractures start at the nasofrontal and frontomaxillary sutures and extend posteriorly along the medial wall of the orbit through the nasolacrimal groove and ethmoid bones. The thicker sphenoid bone posteriorly usually prevents continuation of the fracture into the optic canal. Instead, the fracture continues along the floor of the orbit along the inferior orbital fissure and continues superolaterally through the lateral orbital wall, through the zygomaticofrontal junction and the zygomatic arch. Intranasally, a branch of the fracture extends through the base of the perpendicular plate of the ethmoid, through the vomer, and through the interface of the pterygoid plates to the base of the sphenoid. This type of fracture predisposes the patient to CSF rhinorrhea more commonly than the other types. Ocular injuries Superior orbital fissure syndrome Severe force to the lateral wall of the orbit resulting in compression of neurovascular structures. Results in : Complete opthalmoplegia and ptosis (Cranial nerves 3, 4, 6 and nerve to levator palpebrae superioris) Relative afferent pupillary defect Dilatation of the pupil and loss of accommodation and corneal reflexes Altered sensation from forehead to vertex (frontal branch of trigeminal nerve) Orbital blow out fracture Typically occurs when an object of slightly larger diameter than the orbital rim strikes the incompressible eyeball. The bone fragment is displaced downwards into the antral cavity, remaining attached to the orbital periosteum. Periorbital fat may be herniated through the defect, interfering with the inferior rectus and inferior oblique muscles which are contained within the same fascial sheath. This prevents upward movement and outward rotation of the eye and the patient experiences diplopia on upward gaze. The initial bruising and swelling may make assessment difficult and patients should usually be reviewed 5 days later. Residual defects may require orbital floor reconstruction. Nasal Fractures Common injury Ensure new and not old deformity Control epistaxis CSF rhinorrhoea implies that the cribriform plate has been breached and antibiotics will be required. Usually best to allow bruising and swelling to settle and then review patient clinically. Major persistent deformity requires fracture manipulation, best performed within 10 days of injury. Retrobulbar haemorrhage Rare but important ocular emergency. Presents with: Pain (usually sharp and within the globe) Proptosis Pupil reactions are lost Paralysis (eye movements lost) Visual acuity is lost (colour vision is lost first) May be the result of Le Fort type facial fractures. Management: Mannitol 1g/Kg as 20% infusion, Osmotic diuretic, Contra-indicated in congestive heart failure and pulmonary oedema Acetazolamide 500mg IV, (Monitor FBC/U+E) Reduces aqueous pressure by inhibition of carbonic anhydrase (used in glaucoma) Dexamethasone 8mg orally or intravenously In a traumatic setting an urgent cantholysis may be needed prior to definitive surgery. Consider Papaverine 40mg smooth muscle relaxant Dextran 40 500mls IV improves perfusion

Answer 1291

Thyroglobulin, the major constituent of colloid and precursor of thyroid hormones may be elevated in those with metastatic or recurrent thyroid cancer. Results may be erroneous in those with other thyroid disorders. Blood testing in thyroid disease Assay Usage Thyroid peroxidase (microsomal) antibodies Found in autoimmune disease affecting the thyroid (Hashimotos 100%) and Graves (70%) Antibodies to TSH receptor Individuals with Graves disease (95%) Thyroglobulin Not useful for clinically distinguishing between different types of thyroid disease, may be used as part of thyroid cancer follow up Calcitonin Released from the parafollicular cells Usually found in patients with medullary carcinoma of the thyroid

Answer 1292

Neurofibromatosis type I. A hallmark finding is a plexiform neurofibroma, which is a sheet of neurofibromatosis tissue which encases major nerves. In children this attracts extra blood circulation, which can accelerate growth of the affected limb. Other features include: Schwannoma, > 6 Cafe au lait spots, axillary freckling, Lisch nodules, Optic glioma. Meningiomas, Glioma, or Schwannoma. Genetics and surgical disease Some of the more commonly occurring genetic conditions occurring in surgical patients are presented here. Li-Fraumeni Syndrome Autosomal dominant Consists of germline mutations to p53 tumour suppressor gene High incidence of malignancies particularly sarcomas and leukaemias Diagnosed when: *Individual develops sarcoma under 45 years *First degree relative diagnosed with any cancer below age 45 years and another family member develops malignancy under 45 years or sarcoma at any age BRCA 1 and 2 Carried on chromosome 17 (BRCA 1) and Chromosome 13 (BRCA 2) Linked to developing breast cancer (60%) risk. Associated risk of developing ovarian cancer (55% with BRCA 1 and 25% with BRCA 2). Lynch Syndrome Autosomal dominant Develop colonic cancer and endometrial cancer at young age 80% of affected individuals will get colonic and/ or endometrial cancer High risk individuals may be identified using the Amsterdam criteria Amsterdam criteria Three or more family members with a confirmed diagnosis of colorectal cancer, one of whom is a first degree (parent, child, sibling) relative of the other two. Two successive affected generations. One or more colon cancers diagnosed under age 50 years. Familial adenomatous polyposis (FAP) has been excluded. Gardners syndrome Autosomal dominant familial colorectal polyposis Multiple colonic polyps Extra colonic diseases include: skull osteoma, thyroid cancer and epidermoid cysts Desmoid tumours are seen in 15% Mutation of APC gene located on chromosome 5 Due to colonic polyps most patients will undergo colectomy to reduce risk of colorectal cancer Now considered a variant of familial adenomatous polyposis coli

Answer 1293

In children aged 6 months to 4 years, Kigella is the most likely infecting organism. S Aureus affects smaller babies. Discitis in children In children, infectious discitis (D) and infectious spondylodiscitis (SD) are rare diseases that can cause significant clinical problems, including spinal deformities and segmental instabilities. Moreover, when the infection spreads into the spinal channel, D and SD can cause devastating neurologic complications. Early diagnosis and treatment may reduce these risks. Several different bacterial pathogens can cause D and SD, and, in some cases, particularly those due to Staphylococcus aureus, Kingella kingae, Mycobacterium tuberculosis, Brucella spp., the appropriate choice of drug is critical to achieve cure. In most cases the infections spreads to the site haematogenously from a separate site. Less commonly, it arises as a result of direct inoculation. A triphasic age distribution is described; the first peak incidence is in children aged only a few weeks or months old, the second in those between 6 months and the end of the preschool period, and the third in school-aged children. Initial treatment is with broad spectrum intravenous antibiotics that cover s aureus, children aged 4 months to 6 years need cover for Kigella. More tailored therapy can be added later depending on progress and culture results.

Answer 1294

It lies deep to pronator teres and this separates it from the median nerve. Ulnar artery Path Starts: middle of antecubital fossa Passes obliquely downward, reaching the ulnar side of the forearm at a point about midway between the elbow and the wrist. It follows the ulnar border to the wrist, crossing over the flexor retinaculum. It then divides into the superficial and deep volar arches. Relations Deep to- Pronator teres, Flexor carpi ulnaris, Palmaris longus Lies on- Brachialis and Flexor digitorum profundus Superficial to the flexor retinaculum at the wrist The median nerve is in relation with the medial side of the artery for about 2.5 cm. And then crosses the vessel, being separated from it by the ulnar head of the Pronator teres The ulnar nerve lies medially to the lower two-thirds of the artery Branch Anterior interosseous artery

Answer 1295

B-Mentalis Buccal branch supplies Zygomaticus minor Elevates upper lip Buccinator Pulls corner of mouth backward and compresses cheek Levator anguli oris Pulls angles of mouth upward and toward midline Orbicularis Closes and tightens lips together Nasalis Flares nostrils and compresses nostrils The orbicularis oris has innervation by both the buccal and marginal mandibular branches of the facial nerve. Facial nerve The facial nerve is the main nerve supplying the structures of the second embryonic branchial arch. It is predominantly an efferent nerve to the muscles of facial expression, digastric muscle and also to many glandular structures. It contains a few afferent fibres which originate in the cells of its genicular ganglion and are concerned with taste. Supply - 'face, ear, taste, tear' Face: muscles of facial expression Ear: nerve to stapedius Taste: supplies anterior two-thirds of tongue Tear: parasympathetic fibres to lacrimal glands, also salivary glands Path Subarachnoid path Origin: motor- pons, sensory- nervus intermedius Pass through the petrous temporal bone into the internal auditory meatus with the vestibulocochlear nerve. Here they combine to become the facial nerve. Facial canal path The canal passes superior to the vestibule of the inner ear At the medial aspect of the middle ear, it becomes wider and contains the geniculate ganglion. - 3 branches: 1. greater petrosal nerve 2. nerve to stapedius 3. chorda tympani Stylomastoid foramen Passes through the stylomastoid foramen (tympanic cavity anterior and mastoid antrum posteriorly) Posterior auricular nerve and branch to posterior belly of digastric and stylohyoid muscle Face Enters parotid gland and divides into 5 branches: Temporal branch Zygomatic branch Buccal branch Marginal mandibular branch Cervical branch

Answer 1296

A useful revision aid : 'Capital Radio' is the articulation of the radial head superiorly. The head of the radius articulates with the capitulum of the humerus. Radius The radius is one of the two long forearm bones that extends from the lateral side of the elbow to the thumb side of the wrist. It has two expanded ends, of which the distal end is the larger. Key points relating to its topography and relations are outlined below; Upper end Articular cartilage- covers medial > lateral side Articulates with radial notch of the ulna by the annular ligament Muscle attachment- biceps brachii at the tuberosity Shaft Muscle attachment Upper third of the body Supinator Flexor digitorum superficialis Flexor pollicis longus Middle third of the body Pronator teres Lower quarter of the body Pronator quadratus Tendon of supinator longus Lower end Quadrilateral Anterior surface- capsule of wrist joint Medial surface- head of ulna Lateral surface- ends in the styloid process Posterior surface: 3 grooves containing: 1. Tendons of extensor carpi radialis longus and brevis 2. Tendon of extensor pollicis longus 3. Tendon of extensor indicis

Answer 1297

Whilst all the cell types listed can produce complement proteins, the greatest contribution is made from the hepatocytes. Indeed, most soluble proteins are synthesized by the liver. Complement system The complement system plays a crucial role in the innate defense against common pathogens. Activation of complement leads to robust and efficient proteolytic cascades, which terminate in opsonization and lysis of the pathogen as well as in the generation of the classical inflammatory response through the production of potent proinflammatory molecules. Proteolytic cascades include: potent proinflammatory mediators (anaphylatoxins), opsonization (coating) of the pathogenic surface through various complement opsonins (e.g., C3b), and targeted lysis of the pathogenic surface through the assembly of membrane-penetrating pores known as the membrane attack complex (MAC). Complement is activated via one of three major pathways; classical, lectin and alternative. The final output of the system is inflammation, lysis or opsonization.

Answer 1298

Usually open surgery is required for these lesions as customised grafts are not usually available for this type of repair yet. Aortic dissection More common than rupture of the abdominal aorta 33% of patients die within the first 24 hours, and 50% die within 48 hours if no treatment received Associated with hypertension Features of aortic dissection: tear in the intimal layer, followed by formation and propagation of a subintimal hematoma. Cystic medial necrosis (Marfan's) Most common site of dissection: 90% occurring within 10 centimetres of the aortic valve Stanford Classification Type Location Treatment A Ascending aorta/ aortic root Surgery- aortic root replacement B Descending aorta Medical therapy with antihypertensives DeBakey classification Type Site affected I Ascending aorta, aortic arch, descending aorta II Ascending aorta only III Descending aorta distal to left subclavian artery Clinical features Tearing, sudden onset chest pain (painless 10%) Hypertension or Hypotension A blood pressure difference (in each arm) greater than 20 mm Hg Neurologic deficits (20%) Investigations CXR: widened mediastinum, abnormal aortic knob, ring sign, deviation of the trachea/oesophagus CT angiography of the thoracic aorta MRI angiography Conventional angiography (now rarely used diagnostically) Management Beta-blockers: aim HR 60-80 bpm and systolic BP 100-120 mm Hg For type A dissections the standard of care is aortic root replacement

Answer 1299

In young children, laparotomy is performed via transverse supra umbilical incision. Access via midline incisions is very poor and they should not be used. Abdominal incisions Midline incision Commonest approach to the abdomen Structures divided: linea alba, transversalis fascia, extraperitoneal fat, peritoneum (avoid falciform ligament above the umbilicus) Bladder can be accessed via an extraperitoneal approach through the space of Retzius Paramedian incision Parallel to the midline (about 3-4cm) Structures divided/retracted: anterior rectus sheath, rectus (retracted), posterior rectus sheath, transversalis fascia, extraperitoneal fat, peritoneum Incision is closed in layers Battle Similar location to paramedian but rectus displaced medially (and thus denervated) Now seldom used Kocher's Incision under right subcostal margin e.g. Cholecystectomy (open) Lanz Incision in right iliac fossa e.g. Appendicectomy Gridiron Oblique incision centered over McBurneys point- usually appendicectomy (less cosmetically acceptable than Lanz Gable Rooftop incision Pfannenstiel's Transverse supra pubic, primarily used to access pelvic organs McEvedy's Groin incision e.g. Emergency repair strangulated femoral hernia Rutherford Morrison Extraperitoneal approach to left or right lower quadrants. Gives excellent access to iliac vessels and is the approach of choice for first time renal transplantation.

Answer 1300

The dorsal carpal branch vessels supply 80% of the scaphoid via retrograde flow. There is a minor supply from the superficial palmar arch vessels that supplies the distal 20% of the scaphoid. Scaphoid bone The scaphoid has a concave articular surface for the head of the capitate and at the edge of this is a crescentic surface for the corresponding area on the lunate. Proximally, it has a wide convex articular surface with the radius. It has a distally sited tubercle that can be palpated. The remaining articular surface is to the lateral side of the tubercle. It faces laterally and is associated with the trapezium and trapezoid bones. The narrow strip between the radial and trapezial surfaces and the tubercle gives rise to the radial collateral carpal ligament. Blood supply This is from the scaphoid tubercle vessels that comprise 20% and the dorsal ridge vessels that supply 80%.

Answer 1301

A-Supinator Nerve lesions during surgery A variety of different procedures carry the risk of iatrogenic nerve injury. These are important not only from the patients perspective but also from a medicolegal standpoint. The following operations and their associated nerve lesions are listed here: Posterior triangle lymph node biopsy and accessory nerve lesion. Lloyd Davies stirrups and common peroneal nerve. Thyroidectomy and laryngeal nerve. Anterior resection of rectum and hypogastric autonomic nerves. Axillary node clearance; long thoracic nerve, thoracodorsal nerve and intercostobrachial nerve. Inguinal hernia surgery and ilioinguinal nerve. Varicose vein surgery- sural and saphenous nerves. Posterior approach to the hip and sciatic nerve. Carotid endarterectomy and hypoglossal nerve. There are many more, with sound anatomical understanding of the commonly performed procedures the incidence of nerve lesions can be minimised. They commonly occur when surgeons operate in an unfamiliar tissue plane or by blind placement of haemostats (not recommended).

Answer 1302

The recurrence of symptoms following medical therapy attracts a recommendation for definitive treatment. Since radio-iodine can worsen eye signs, this is not a wise choice. Surgery in the form of a total thyroidectomy would be curative. Management of thyroid disease Management of thyroid disease Lesion Management Large multinodular goitre Surgery for pressure symptoms. Total thyroidectomy is treatment of choice Toxic nodule Hemithyroidectomy Follicular lesion (THY 3f) Hemithyroidectomy to establish diagnosis Papillary thyroid cancer Total thyroidectomy and central compartment nodal dissection (extended lymphadenectomy as required) Follicular thyroid cancer Total thyroidectomy (usually completion as already had hemithyroidectomy) Anaplastic thyroid cancer Palliative radiotherapy Medullary thyroid cancer Total thyroidectomy and central compartment nodal dissection (screen for other MEN tumours) Lymphoma of the thyroid Consider core biopsy Persistent refilling cysts Injection sclerotherapy and surgery if this fails Graves disease with significant eye signs Total thyroidectomy Graves disease without significant eye signs Patient choice radioiodine Vs surgery

Answer 1303

An inferior myocardial infarction and AR murmur should raise suspicions of an ascending aorta dissection rather than an inferior myocardial infarction alone. Also the history is more suggestive of a dissection. Other features may include pericardial effusion, carotid dissection and absent subclavian pulse. Chest pain Aortic dissection This occurs when there is a flap or filling defect within the aortic intima. Blood tracks into the medial layer and splits the tissues with the subsequent creation of a false lumen. It most commonly occurs in the ascending aorta or just distal to the left subclavian artery (less common). It is most common in Afro-carribean males aged 50-70 years. Patients usually present with a tearing intrascapular pain, which may be similar to the pain of a myocardial infarct. The dissection may spread either proximally or distally with subsequent disruption to the arterial branches that are encountered. In the Stanford classification system the disease is classified into lesions with a proximal origin (Type A) and those that commence distal to the left subclavian (Type B). Diagnosis may be suggested by a chest x-ray showing a widened mediastinum. Confirmation of the diagnosis is usually made by use of CT angiography Proximal (Type A) lesions are usually treated surgically, type B lesions are usually managed non operatively. Pulmonary embolism Typically sudden onset of chest pain, haemoptysis, hypoxia and small pleural effusions may be present. Most patients will have an underlying deep vein thrombosis Diagnosis may be suggested by various ECG findings including S waves in lead I, Q waves in lead III and inverted T waves in lead III. Confirmation of the diagnosis is usually made through use of CT pulmonary angiography. Treatment is with anticoagulation, in those patients who develop a cardiac arrest or severe compromise from their PE, consideration may be given to thrombolysis. Myocardial infarction Traditionally described as sudden onset of central, crushing chest pain. It may radiate into the neck and down the left arm. Signs of autonomic dysfunction may be present. The presenting features may be atypical in the elderly and those with diabetes. Diagnosis is made through identification of new and usually dynamic ECG changes (and cardiac enzyme changes). Inferior and anterior infarcts may be distinguished by the presence of specific ECG changes (usually II, III and aVF for inferior, leads V1-V5 for anterior). Treatment is with oral antiplatelet agents, primary coronary angioplasty and/ or thrombolysis. Perforated peptic ulcer Patients usually develop sudden onset of epigastric abdominal pain, it may be soon followed by generalised abdominal pain. There may be features of antecendant abdominal discomfort, the pain of gastric ulcer is typically worse immediately after eating. Diagnosis may be made by erect chest x-ray which may show a small amount of free intra-abdominal air (very large amounts of air are more typically associated with colonic perforation). Treatment is usually with a laparotomy, small defects may be excised and overlaid with an omental patch, larger defects are best managed with a partial gastrectomy. Boerhaaves syndrome Spontaneous rupture of the oesophagus that occurs as a result of repeated episodes of vomiting. The rupture is usually distally sited and on the left side. Patients usually give a history of sudden onset of severe chest pain that may complicate severe vomiting. Severe sepsis occurs secondary to mediastinitis. Diagnosis is CT contrast swallow. Treatment is with thoracotomy and lavage, if less than 12 hours after onset then primary repair is usually feasible, surgery delayed beyond 12 hours is best managed by insertion of a T tube to create a controlled fistula between oesophagus and skin. Delays beyond 24 hours are associated with a very high mortality rate.

Answer 1304

Hypoxaemia and acidosis may both affect cerebral blood flow. However, in the traumatic situation increases in intracranial pressure are far more likely to occur especially when GCS is low. This will adversely affect cerebral blood flow. Cerebral blood flow - CNS autoregulates its own blood supply Factors affecting the cerebral pressure include; systemic carbon dioxide levels, CNS metabolism, CNS trauma, CNS pressure The PaCO2 is the most potent mediator Acidosis and hypoxaemia will increase cerebral blood flow but to a lesser degree Intra cranial pressure may increase in patients with head injuries and this can result in impaired blood flow Intra cerebral pressure is governed by Monroe-Kelly Doctrine which considers skull as closed box, changes in pressure are offset by loss of CSF. When this is no longer possible ICP rises

Answer 1305

Increasing pain at rest, together with increased serum calcium and alkaline phosphatase are most likely to represent metastatic tumour to bone. Chondrosarcomas do occur in the pelvis but are not associated with increased serum calcium and typically have a longer history. Bone disease Disease Features Treatment Pagets Focal bone resorption followed by excessive and chaotic bone deposition Affects (in order): spine, skull, pelvis and femur Serum alkaline phosphatase raised (other parameters normal) Abnormal thickened, sclerotic bone on x-rays Risk of cardiac failure with >15% bony involvement Small risk of sarcomatous change Bisphosphonates Osteoporosis Excessive bone resorption resulting in demineralised bone Commoner in old age Increased risk of pathological fracture, otherwise asymptomatic Alkaline phosphatase normal, calcium normal Bisphosphonates, calcium and vitamin D Secondary bone tumours Bone destruction and tumour infiltration Mirel scoring used to predict risk of fracture Appearances depend on primary (e.g.sclerotic - prostate, lytic - breast) Elevated serum calcium and alkaline phosphatase may be seen Radiotherapy, prophylactic fixation and analgesia

Answer 1306

Patients with MEN IIb may display Marfanoid features. It is unclear at the present time whether they have discrete changes in the microfibrils of elastic fibres that are present in Marfans. Multiple Endocrine Neoplasia Multiple endocrine neoplasia (MEN) is inherited as an autosomal dominant disorder. The table below summarises the three main types of MEN: MEN type I MEN type IIa MEN type IIb Mnemonic 'three P's': Parathyroid (95%): Parathyroid adenoma Pituitary (70%): Prolactinoma/ACTH/Growth Hormone secreting adenoma Pancreas (50%): Islet cell tumours/Zollinger Ellison syndrome also: Adrenal (adenoma) and thyroid (adenoma) Phaeochromocytoma Medullary thyroid cancer (70%) Hyperparathyroidism (60%) Same as MEN IIa with addition of: Marfanoid body habitus Mucosal neuromas MENIN gene (chromosome 11) Most common presentation = hypercalcaemia RET oncogene (chromosome 10) RET oncogene (chromosome 10)

Answer 1307

This is the classic description of acalculous cholecystitis and its commonest in patients with type 2 diabetes. If you answered it incorrectly, ensure that you were not caught out by the acute calculous cholecystitis as this is a common exam mistake if options are mis read in a rush. Gallstones Up to 24% of women and 12% of men may have gallstones. Of these up to 30% may develop local infection and cholecystitis. In patients subjected to surgery 12% will have stones contained within the common bile duct. The majority of gallstones are of a mixed composition (50%) with pure cholesterol stones accounting for 20% of cases. The aetiology of CBD stones differs in the world, in the West most CBD stones are the result of migration. In the East a far higher proportion arise in the CBD de novo. The classical symptoms are of colicky right upper quadrant pain that occurs post prandially. The symptoms are usually worst following a fatty meal when cholecystokinin levels are highest and gallbladder contraction is maximal. Investigation In almost all suspected cases the standard diagnostic work up consists of abdominal ultrasound and liver function tests. Of patients who have stones within the bile duct, 60% will have at least one abnormal result on LFT's. Ultrasound is an important test, but is operator dependent and therefore may occasionally need to be repeated if a negative result is at odds with the clinical picture. Where stones are suspected in the bile duct, the options lie between magnetic resonance cholangiography and intraoperative imaging. The choice between these two options is determined by the skills and experience of the surgeon. The advantages of intra operative imaging are less useful in making therapeutic decisions if the operator is unhappy about proceeding the bile duct exploration, and in such circumstances pre operative MRCP is probably a better option. Specific gallstone and gallbladder related disease Disease Features Management Biliary colic Colicky abdominal pain, worse post prandially, worse after fatty foods If imaging shows gallstones and history compatible then laparoscopic cholecystectomy Acute cholecystitis Right upper quadrant pain Fever Murphys sign on examination Occasionally mildly deranged LFT's (especially if Mirizzi syndrome) Imaging (USS) and cholecystectomy (ideally within 48 hours of presentation) (2) Gallbladder abscess Usually prodromal illness and right upper quadrant pain Swinging pyrexia Patient may be systemically unwell Generalised peritonism not present Imaging with USS +/- CT Scanning Ideally surgery, sub total cholecystectomy may be needed if Calots triangle is hostile In unfit patients percutaneous drainage may be considered Cholangitis Patient severely septic and unwell Jaundice Right upper quadrant pain Fluid resuscitation Broad spectrum intravenous antibiotics Correct any coagulopathy Early ERCP Gallstone ileus Patients may have a history of previous cholecystitis and known gallstones Small bowel obstruction (may be intermittent) Laparotomy and removal of gallstone from small bowel, the enterotomy must be made proximal to the site of obstruction and not at the site of obstruction. The fistula between the gallbladder and duodenum should not be interfered with. Acalculous cholecystitis Patients with inter current illness (e.g. diabetes, organ failure) Patient of systemically unwell Gallbladder inflammation in absence of stones High fever If patient fit then cholecystectomy, if unfit then percutaneous cholecystostomy Treatment Patients with asymptomatic gallstones rarely develop symptoms related to them (less than 2% per year) and may therefore be managed expectantly. In almost all cases of symptomatic gallstones the treatment of choice is cholecystectomy performed via the laparoscopic route. In the very frail patient there is sometimes a role for selective use of ultrasound guided cholecystostomy. During the course of the procedure some surgeons will routinely perform either intra operative cholangiography or laparoscopic USS to either confirm anatomy or to exclude CBD stones. The latter may be more easily achieved by use of laparoscopic ultrasound. If stones are found then the options lie between early ERCP in the day or so following surgery or immediate surgical exploration of the bile duct. When performed via the trans cystic route this adds little in the way of morbidity and certainly results in faster recovery. Where transcystic exploration fails the alternative strategy is that of formal choledochotomy. The exploration of a small duct is challenging and ducts of less than 8mm should not be explored. Small stones that measure less than 5mm may be safely left and most will pass spontaneously. Risks of ERCP(1) Bleeding 0.9% (rises to 1.5% if sphincterotomy performed) Duodenal perforation 0.4% Cholangitis 1.1% Pancreatitis 1.5% References 1. Williams E et al. Guidelines on the management of common bile duct stones (CBDS)Gut 2008;57:10041021 2. Gurusamy KS, Samraj K. Early versus delayed laparoscopic cholecystectomy for acute cholecystitis. Cochrane Database Syst Rev. 2006 Oct 18;(4):CD005440. 3. Gurusamy K and Davidson B. Gallstones. BMJ 2014 (348):27-30.

Answer 1308

Patients with electrolyte disturbance and previous surgery may develop colonic pseudo-obstruction (Ogilvies syndrome). The diagnosis is made using a contrast enema and treatment is usually directed at the underlying cause with colonic decompression if indicated. Colonic obstruction Cause Features Treatment Cancer Usually insidious onset History of progressive constipation Systemic features (e.g. anaemia) Abdominal distension Absence of bowel gas distal to site of obstruction Establish diagnosis (e.g. contrast enema/ endoscopy) Laparotomy and resection, stenting, defunctioning colostomy or bypass Diverticular stricture Usually history of previous acute diverticulitis Long history of altered bowel habit Evidence of diverticulosis on imaging or endoscopy Once diagnosis established, usually surgical resection Colonic stenting should not be performed for benign disease Volvulus Twisting of bowel around its mesentery Sigmoid colon affected in 76% cases Patients usually present with abdominal pain, bloating and constipation Examination usually shows asymmetrical distension Plain X-rays usually show massively dilated sigmoid colon, loss of haustra and U shape are typical, the loop may contain fluid levels Initial treatment is to untwist the loop, a flexible sigmoidoscopy may be needed Those with clinical evidence of ischaemia should undergo surgery Patient with recurrent volvulus should undergo resection Acute colonic pseudo-obstruction Symptoms and signs of large bowel obstruction with no lesion Usually associated with metabolic disorders Usually a cut off in the left colon (82% cases) Although abdomen tense and distended, it is usually not painful All patients should undergo contrast enema (may be therapeutic) Colonoscopic decompression Correct metabolic disorders IV neostigmine Surgery

Answer 1309

This man will have a contained haematoma and is awaiting surgery. Rapid, high volume infusions may cause this to dislodge with disastrous consequences. In emergency aortic surgery a policy of permissive hypotension is utilised to reduce the risk. Abdominal aorta aneurysm - Abdominal aortic aneurysms are a common problem in vascular surgery. They may occur as either true or false aneurysm. With the former all 3 layers of the arterial wall are involved, in the latter only a single layer of fibrous tissue forms the aneurysm wall. True abdominal aortic aneurysms have an approximate incidence of 0.06 per 1000 people. They are commonest in elderly men and for this reason the UK is now introducing the aneurysm screening program with the aim of performing an abdominal aortic ultrasound measurement in all men aged 65 years. Causes Several different groups of patients suffer from aneurysmal disease. The commonest group is those who suffer from standard arterial disease, i.e. Those who are hypertensive and have been or are smokers. Other patients such as those suffering from connective tissue diseases such as Marfan's may also develop aneurysms. In patients with abdominal aortic aneurysms the extracellular matrix becomes disrupted with a change in the balance of collagen and elastic fibres. Management Most abdominal aortic aneurysms are an incidental finding. Symptoms most often relate to rupture or impending rupture. 20% rupture anteriorly into the peritoneal cavity. Very poor prognosis. 80% rupture posteriorly into the retroperitoneal space The risk of rupture is related to aneurysm size, only 2% of aneurysms measuring less than 4cm in diameter will rupture over a 5 year period. This contrasts with 75% of aneurysms measuring over 7cm in diameter. This is well explained by Laplaces' law which relates size to transmural pressure. For this reason most vascular surgeons will subject patients with an aneurysm size of 5cm or greater to CT scanning of the chest, abdomen and pelvis with the aim of delineating anatomy and planning treatment. Depending upon co-morbidities, surgery is generally offered once the aneurysm is between 5.5cm and 6cm. Indications for surgery Symptomatic aneurysms (80% annual mortality if untreated) Increasing size above 5.5cm if asymptomatic Rupture (100% mortality without surgery) Surgical procedures Abdominal aortic aneurysm repair Procedure: GA Invasive monitoring (A-line, CVP, catheter) Incision: Midline or transverse Bowel and distal duodenum mobilised to access aorta. Aneurysm neck and base dissected out and prepared for cross clamp Systemic heparinisation Cross clamp (proximal first) Longitudinal aortotomy Atherectomy Deal with back bleeding from lumbar vessels and inferior mesenteric artery Insert graft either tube or bifurcated depending upon anatomy Suture using Prolene (3/0 for proximal , distal anastomosis suture varies according to site) Clamps off: End tidal CO2 will rise owing to effects of reperfusion, at this point major risk of myocardial events. Haemostasis Closure of aneurysm sac to minimise risk of aorto-enteric fistula Closure: Loop 1 PDS or Prolene to abdominal wall Skin- surgeons preference Post operatively: ITU (Almost all) Greatest risk of complications following emergency repair Complications: Embolic- gut and foot infarcts Cardiac - owing to premorbid states, re-perfusion injury and effects of cross clamp Wound problems Later risks related to graft- infection and aorto-enteric fistula Special groups Supra renal AAA These patients will require a supra renal clamp and this carries a far higher risk of complications and risk of renal failure. Ruptured AAA Pre-operatively the management depends upon haemodynamic instability. In patients with symptoms of rupture (typical pain, haemodynamic compromise and risk factors) then ideally prompt laparotomy. In those with vague symptoms and haemodynamic stability the ideal test is CT scan to determine whether rupture has occurred or not. Most common rupture site is retroperitoneal 80%. These patients will tend to develop retroperitoneal haematoma. This can be disrupted if Bp is allowed to rise too high so aim for Bp 100mmHg. Operative details are similar to elective repair although surgery should be swift, blind rushing often makes the situation worse. Plunging vascular clamps blindly into a pool of blood at the aneurysm neck carries the risk of injury the vena cava that these patients do not withstand. Occasionally a supracoeliac clamp is needed to effect temporary control, although leaving this applied for more than 20 minutes tends to carry a dismal outcome. EVAR Increasingly patients are now being offered endovascular aortic aneurysm repair. This is undertaken by surgeons and radiologists working jointly. The morphology of the aneurysm is important and not all are suitable. Here is a typical list of those features favoring a suitable aneurysm: Long neck Straight iliac vessels Healthy groin vessels Clearly few AAA patients possess the above and compromise has to be made. The use of fenestrated grafts can allow supra renal AAA to be treated. Procedure: GA Radiology or theatre Bilateral groin incisions Common femoral artery dissected out Heparinisation Arteriotomy and insertion of guide wire Dilation of arteriotomy Insertion of EVAR Device Once in satisfactory position it is released Arteriotomy closed once check angiogram shows good position and no endoleak Complications: Endoleaks depending upon site are either Type I or 2. These may necessitate re-intervention and all EVAR patients require follow up . Details are not needed for MRCS. References A reasonable review is provided by: Sakalihasan N, Limet R, Defawe O. Abdominal aortic aneurysm. Lancet 2005 (365):1577- 1589

Answer 1310

Always ensure that children with intussusception are resuscitated first. Administration of antibiotics is also important. This should precede any intervention. Intussusception- Paediatric Intussusception typically presents with colicky abdominal pain and vomiting. The telescoping of the bowel produces mucosal ischaemia and bleeding may occur resulting in the passage of red current jelly stools. Recognised causes include lumenal pathologies such as polyps, lymphadenopathy and diseases such as cystic fibrosis. Idiopathic intussceception of the ileocaecal valve and terminal ileum is the most common variant and typically affects young children and toddlers. The diagnosis is usually made by abdominal ultrasound investigation. The decision as to the optimal treatment is dictated by the patients physiological status and abdominal signs. In general, children who are unstable with localising peritoneal signs should undergo laparotomy, as should those in whom attempted radiological reduction has failed. In relatively well children, without localising signs, attempted pneumatic reduction under fluroscopic guidance is the usual treatment. This is not done where there are concerns about impending perforation or if there is a small bowel intussusception.

Answer 1311

A fracture may still be present and should be immobilised until repeat imaging can be performed. If clinical suspicion persists then subsequent imaging should be with MRI scanning or CT if MRI is contra-indicated. Scaphoid fractures - Incidence of scaphoid fractures in UK ranges from 12.4 per 100,000 to 29 per 100,000 Surface of scaphoid is covered by articular cartilage with small area available for blood vessels (fracture risks blood supply) Forms floor of anatomical snuffbox Risk of fracture associated with fall onto outstretched hand (tubercle, waist, or proximal third) A series of 4 scaphoid radiographs should be undertaken (PA, pronated oblique, Ziter view and lateral view). The Ziter view is a PA view with the wrist in ulnar deviation and beam angulated at 20 degrees Sensitivity of scaphoid radiographs in 1st week of injury is 80% Immobilization of scaphoid fractures difficult Repeat imaging should be done at 10 days. MRI should be done in cases of diagnostic uncertainty Classification of scaphoid fractures Scaphoid tubercle Distal pole Waist Proximal pole Management Undisplaced fractures of the waist of the scaphoid and most distal pole fractures can be managed in a cast for 6 weeks with high rates of union. Displaced scaphoid waist fractures (more than 1-2mm) should be viewed as unstable and surgically fixed. All proximal pole fractures should be fixed surgically. Complications Non union of scaphoid Avascular necrosis of the scaphoid Scapholunate disruption and wrist collapse Degenerative changes of the adjacent joint Reference Berber O et al. Fractures of the scaphoid. BMJ 2020 (369): 414-416.

Answer 1312

A mid diastolic murmur at the apex is a classical description of a mitral stenosis murmur. The most common cause is rheumatic heart disease. Complications of mitral stenosis include atrial fibrillation, stroke, myocardial infarction and infective endocarditis. Cardiac murmurs Type of Murmur Conditions Ejection systolic Aortic stenosis Pulmonary stenosis, HOCM ASD, Fallot's Pan-systolic Mitral regurgitation Tricuspid regurgitation VSD Late systolic Mitral valve prolapse Coarctation of aorta Early diastolic Aortic regurgitation Graham-Steel murmur (pulmonary regurgitation) Mid diastolic Mitral stenosis Austin-Flint murmur (severe aortic regurgitation)

Answer 1313

B- Immediate exploration and repair The five P's of arterial injury include pain, parasthesias, pallor, pulselessness and paralysis. In the extremities, the tissues most sensitive to anoxia are the peripheral nerves and striated muscle. The early developments of paresthesias and paralysis are signals that there is significant ischemia present, and immediate exploration and repair are warranted. The presence of palpable pulse does not exclude an arterial injury because this presence may represent a transmitted pulsation through a blood clot. When severe ischemia is present, the repair must be completed within 6 to 8 h to prevent irreversible muscle ischemia and loss of limb function. Delay to obtain a conventional angiogram or to observe for change needlessly prolongs the ischemic time. A CT angiogram may be a reasonable alternative. Fasciotomy may be required but should be done in conjunction with and after re-establishment of arterial flow. Local wound exploration is not recommended because brisk hemorrhage may be encountered without the securing of prior vascular control. Vascular trauma Peripheral and central vessels may be injured by blunt, penetrating or shearing injuries. Fractures of bones close to vessels may also be associated with vascular injury or vessel occlusion. Assessment Check for signs of distal perfusion Doppler signal distally (monophasic/ biphasic or triphasic) Anatomical location (which vessel is likely to be involved) Duplex scanning and angiography are 'gold standard' tests but may not be immediately available in the trauma setting Management Almost always operative. Obtaining proximal and distal control of affected vessels is crucial. Simple lacerations of arteries may be directly closed, or a vein patch applied if there is a risk of subsequent stenosis. Transection of the vessel should be treated by either end to end anastomosis (often not possible) or an interposition vein graft. Use of PTFE in traumatic open injuries will invariably result in infection.

Answer 1314

The lymphatic drainage of the ovary follows the gonadal vessels and drainage is therefore to the para-aortic nodes. Lymphatic drainage of the ovaries, uterus and cervix The ovaries drain to the para-aortic lymphatics via the gonadal vessels. The uterine fundus has a lymphatic drainage that runs with the ovarian vessels and may thus drain to the para-aortic nodes. Some drainage may also pass along the round ligament to the inguinal nodes. The body of the uterus drains through lymphatics contained within the broad ligament to the iliac lymph nodes. The cervix drains into three potential nodal stations; laterally through the broad ligament to the external iliac nodes, along the lymphatics of the uterosacral fold to the presacral nodes and posterolaterally along lymphatics lying alongside the uterine vessels to the internal iliac nodes.

Answer 1315

Parotid gland secretions account for around 25% of saliva. Most comes from the submandibular gland. Parotid gland secretions - Parotid gland secretions account for around 25% of salivary secretions Levels of sodium and chloride are lower than plasma, potassium and bicarbonate levels are higher Parotid secretions are watery and have high enzyme concentrations Parasympathetic stimulation produces a water rich, serous saliva. Sympathetic stimulation leads to the production of a low volume, enzyme-rich saliva. Fluid that is secreted within the acini is isotonic with plasma and undergoes modification within the ducts via process of ion exchange The ducts are affected by aldosterone and so will retain sodium and secrete potassium when aldosterone levels are elevated

Answer 1316

Hypercapnia will tend to produce cerebral vasodilation. This is of considerable importance in patients with cranial trauma as it may increase intracranial pressure. Applied neurophysiology Pressure within the cranium is governed by the Monroe-Kelly doctrine. This considers the skull as a closed box. Increases in mass can be accommodated by loss of CSF. Once a critical point is reached (usually 100- 120ml of CSF lost) there can be no further compensation and ICP rises sharply. The next step is that pressure will begin to equate with MAP and neuronal death will occur. Herniation will also accompany this process. The CNS can autoregulate its own blood supply. Vaso constriction and dilatation of the cerebral blood vessels is the primary method by which this occurs. Extremes of blood pressure can exceed this capacity resulting in risk of stroke. Other metabolic factors such as hypercapnia will also cause vasodilation, which is of importance in ventilating head injured patients. The brain can only metabolise glucose, when glucose levels fall, consciousness will be impaired.

Answer 1317

The left brachiocephalic vein lies posterior to the manubrium, at the level of its upper border. The sternal angle refers to the transition between manubrium and sternum and therefore will not include the left brachiocephalic vein. Sternal angle Anatomical structures at the level of the manubrium and upper sternum Upper part of the manubrium Left brachiocephalic vein Brachiocephalic artery Left common carotid Left subclavian artery Lower part of the manubrium/ manubrio-sternal angle Costal cartilages of the 2nd ribs Transition point between superior and inferior mediastinum Arch of the aorta Tracheal bifurcation Union of the azygos vein and superior vena cava The thoracic duct crosses to the midline

Answer 1318

E-Supraspinous ligament Lumbar puncture Lumbar punctures are performed to obtain cerebrospinal fluid. In adults, the procedure is best performed at the level of L3/L4 or L4/5 interspace. These regions are below the termination of the spinal cord at L1. During the procedure the needle passes through: The supraspinous ligament which connects the tips of spinous processes and the interspinous ligaments between adjacent borders of spinous processes Then the needle passes through the ligamentum flavum, which may cause a give as it is penetrated A second give represents penetration of the needle through the dura mater into the subarachnoid space. Clear CSF should be obtained at this point References Boon et al Lumbar Puncture: Anatomical Review of a Clinical Skill. Clinical Anatomy 17:544553 (2004)

Answer 1319

Takayasus arteritis may be divided into acute systemic phases and the chronic pulseless phase. In the latter part of the disease process the patient may complain of symptoms such as upper limb claudication. In the later stages of the condition the vessels will typically show changes of intimal proliferation, together with band fibrosis of the intima and media. Vasculitis The vasculitides are a group of conditions characterised by inflammation of the blood vessel walls. This may, in turn, compromise vessel integrity. Constitutional symptoms may be present. Whilst certain disease subtypes are reported to affect specific vessels, there is often a degree of overlap clinically. Vessel diameter and vasculitis classification Aorta and branches Takayasu's arteritis Buergers disease Giant cell arteritis Large and medium sized arteries Buergers disease Giant cell arteritis Polyarteritis nodosa Medium sized muscular arteries Polyarteritis nodosa Wegeners granulomatosis Small muscular arteries Granulomatosis with polyangiitis Rheumatoid vasculitis Specific conditions Takyasu's arteritis Inflammatory, obliterative arteritis affecting aorta and branches Females> Males Symptoms may include upper limb claudication Clinical findings include diminished or absent pulses ESR often affected during the acute phase Buergers disease Segmental thrombotic occlusions of the small and medium sized lower limb vessels Commonest in young male smokers Proximal pulses usually present, but pedal pulses are lost An acuter hypercellular occlusive thrombus is often present Tortuous corkscrew shaped collateral vessels may be seen on angiography Giant cell arteritis Systemic granulomatous arteritis that usually affects large and medium sized vessels Females > Males Temporal arteritis is commonest type Granulomatous lesions may be seen on biopsy (although up to 50% are normal) Polyarteritis nodosa Systemic necrotising vasculitis affecting small and medium sized muscular arteries Most common in populations with high prevalence of hepatitis B Renal disease is seen in 70% cases Angiography may show saccular or fusiform aneurysms and arterial stenoses Granulomatosis with polyangiitis Predominantly affects small and medium sized arteries Systemic necrotising granulomatous vasculitis Cutaneous vascular lesions may be seen (ulceration, nodules and purpura) Sinus imaging may show mucosal thickening and air fluid levels Treatment Conditions such as Buergers disease are markedly helped by smoking cessation. Immunosupression is the main treatment for vasculitides.

Answer 1320

It should not contain red blood cells. Cerebrospinal fluid The CSF fills the space between the arachnoid mater and pia mater (covering surface of the brain). The total volume of CSF in the brain is approximately 150ml. Approximately 500 ml is produced by the ependymal cells in the choroid plexus (70%), or blood vessels (30%). It is reabsorbed via the arachnoid granulations which project into the venous sinuses. Circulation 1. Lateral ventricles (via foramen of Munro) 2. 3rd ventricle 3. Cerebral aqueduct (aqueduct of Sylvius) 4. 4th ventricle 5. Subarachnoid space (via foramina of Magendie and Luschka) 6. Reabsorbed into the venous system via arachnoid granulations into superior sagittal sinus Composition Glucose: 50-80mg/dl Protein: 15-40 mg/dl Red blood cells: Nil White blood cells: 0-3 cells/ mm3

Answer 1321

Patients with metallic heart valves will generally stop unfractionated heparin 6 hours pre operatively. Unfractionated heparin is generally cleared from the circulation within 2 hours so this will allow plenty of time and is the method of choice in the elective setting. Protamine sulphate will reverse heparin but is associated with risks of anaphylaxis and is thus not generally used unless immediate reversal of anticoagulation is needed, e.g. coming off bypass. Heparin Causes the formation of complexes between antithrombin and activated thrombin/factors 7,9,10,11 & 12 Advantages of low molecular weight heparin Better bioavailability Lower risk of bleeding Longer half life Little effect on APTT at prophylactic dosages Less risk of HIT Complications Bleeding Osteoporosis Heparin induced thrombocytopenia (HIT): occurs 5-14 days after 1st exposure Anaphylaxis In surgical patients that may need a rapid return to theatre, administration of unfractionated heparin is preferred; as low molecular weight heparins have a longer duration of action and are harder to reverse.

Answer 1322

Renal plasma flow = (amount of PAH in urine per unit time) / (difference in PAH concentration in the renal artery or vein) Normal value = 660ml/min Renal Physiology Overview Each nephron is supplied with blood from an afferent arteriole that opens onto the glomerular capillary bed. Blood then flows to an efferent arteriole, supplying the peritubular capillaries and medullary vasa recta. The kidney receives up to 25% of resting cardiac output. Control of blood flow The kidney is able to autoregulate its blood flow between systolic pressures of 80- 180mmHg so there is little variation in renal blood flow. This is achieved by myogenic control of arteriolar tone, both sympathetic input and hormonal signals (e.g. renin) are responsible. Glomerular structure and function Blood inside the glomerulus has considerable hydrostatic pressure. The basement membrane has pores that will allow free diffusion of smaller solutes, larger negatively charged molecules such as albumin are unable to cross. The glomerular filtration rate (GFR) is equal to the concentration of a solute in the urine, times the volume of urine produced per minute, divided by the plasma concentration (assuming that the solute is freely diffused e.g. inulin). In clinical practice creatinine is used because it is subjected to very little proximal tubular secretion. Although subject to variability, the typical GFR is 125ml per minute. Glomerular filtration rate = Total volume of plasma per unit time leaving the capillaries and entering the bowman's capsule Renal clearance = volume plasma from which a substance is removed per minute by the kidneys Substances used to measure GFR have the following features: 1. Inert 2. Free filtration from the plasma at the glomerulus (not protein bound) 3. Not absorbed or secreted at the tubules 4. Plasma concentration constant during urine collection Examples: inulin, creatinine GFR = urine concentration (mmol/l) x urine volume (ml/min) -------------------------------------------------------------------------- plasma concentration (mmol/l) The clearance of a substance is dependent not only on its diffusivity across the basement membrane but also subsequent tubular secretion and / or reabsorption. So glucose which is freely filtered across the basement membrane is usually reabsorbed from tubules giving a clearance of zero. Tubular function Reabsorption and secretion of substances occurs in the tubules. In the proximal tubule substrates such as glucose, amino acids and phosphate are co-transported with sodium across the semi permeable membrane. Glucose is reabsorbed by both active and passive processes. The former uses sodiumâ€“glucose co-transporters (SGLTs) in the proximal convoluted tubule. The latter achieved through facilitated and passive process through GLUT transporters. Up to two thirds of filtered water is reabsorbed in the proximal tubules. This will lead to increase in urea concentration in the distal tubule allowing for its increased diffusion. Substances to be secreted into the tubules are taken up from the peritubular blood by tubular cells. Solutes such as paraaminohippuric acid are cleared with a single passage through the kidneys and this is why it is used to measure renal plasma flow. Ions such as calcium and phosphate will have a tubular reabsorption that is influenced by plasma PTH levels. Potassium may be both secreted and re-absorbed and is co-exchanged with sodium. Loop of Henle Approximately 60 litres of water containing 9000mmol sodium enters the descending limb of the loop of Henle in 24 hours. Loops from the juxtamedullary nephrons run deep into the medulla. The osmolarity of fluid changes and is greatest at the tip of the papilla. The thick ascending limb is impermeable to water, but highly permeable to sodium and chloride ions. This loss means that at the beginning of the thick ascending limb the fluid is hypo osmotic compared with adjacent interstitial fluid. In the thick ascending limb the reabsorption of sodium and chloride ions occurs by both facilitated and passive diffusion pathways. The loops of Henle are co-located with vasa recta, these will have similar solute compositions to the surrounding extracellular fluid so preventing the diffusion and subsequent removal of this hypertonic fluid. The energy dependent reabsorption of sodium and chloride in the thick ascending limb helps to maintain this osmotic gradient.

Answer 1323

Birds are a recognised reservoir of campylobacter. Bacterial Gastroenteritis Causative organisms Features Campylobacter jejuni Most common cause of acute infective diarrhoea Spiral, gram negative rods Usually infects caecum and terminal ileum. Local lymphadenopathy is common May mimic appendicitis as it has marked right iliac fossa pain Reactive arthritis is seen in 1-2% of cases Shigella spp. Members of the enterobacteriaceae Gram negative bacilli Clinically causes dysentery Shigella soneii is the commonest infective organism (mild illness) Usually self limiting, ciprofloxacin may be required if individual is in a high risk group Salmonella spp Facultatively anaerobic, gram negative, enterobacteriaceae Infective dose varies according to subtype Salmonellosis: usually transmitted by infected meat (especially poultry) and eggs E. coli Enteropathogenic Enteroinvasive: dysentery, large bowel necrosis/ulcers Enterotoxigenic: small intestine, travelers diarrhoea Enterohaemorrhagic: 0157, cause a haemorrhagic colitis, haemolytic uraemic syndrome and thrombotic thrombocytopaenic purpura Yersinia enterocolitica Gram negative, coccobacilli Typically produces a protracted terminal ileitis that may mimic Crohns disease Differential diagnosis acute appendicitis May progress to septicaemia in susceptible individuals Usually sensitive to quinolone or tetracyclines Vibrio cholera Short, gram negative rods Transmitted by contaminated water, seafood Symptoms include sudden onset of effortless vomiting and profuse watery diarrhoea Correction of fluid and electrolyte losses are the mainstay of treatment Most cases will resolve, antibiotics are not generally indicated

Answer 1324

The foramen marking the distal limit of the adductor canal is contained within adductor magnus. The vessel passes through this region to enter the popliteal fossa. Adductor canal Also called Hunter's or subsartorial canal Immediately distal to the apex of the femoral triangle, lying in the middle third of the thigh. Canal terminates at the adductor hiatus. Borders Contents Laterally Vastus medialis muscle Saphenous nerve Posteriorly Adductor longus, adductor magnus Superficial femoral artery Roof Sartorius Superficial femoral vein

Answer 1325

Insulin is degraded by enzymes in the circulation. It typically has a half life of less than 30 minutes. Abnormalities of the clearance of insulin may occur in type 2 diabetes. Insulin Insulin is a peptide hormone, produced by beta cells of the pancreas, and is central to regulating carbohydrate and fat metabolism in the body. Insulin causes cells in the liver, skeletal muscles, and fat tissue to absorb glucose from the blood. In the liver and skeletal muscles, glucose is stored as glycogen, and in fat cells (adipocytes) it is stored as triglycerides. Structure The human insulin protein is composed of 51 amino acids, and has a molecular weight of 5808 Da. It is a dimer of an A-chain and a B-chain, which are linked together by disulfide bonds. Synthesis Pro-insulin is formed by the rough endoplasmic reticulum in pancreatic beta cells. Then pro-insulin is cleaved to form insulin and C-peptide. Insulin is stored in secretory granules and released in response to Ca2+. Function Secreted in response to hyperglycaemia Glucose utilisation and glycogen synthesis Inhibits lipolysis Reduces muscle protein loss

Answer 1326

The patient's mechanism of injury makes a solid organ injury likely. FAST scanning is associated with a false negative rate in pregnancy which makes the negative result less reassuring. CT scanning remains the gold standard. Imaging in the pregnant trauma patient Sonography and FAST scanning are established in pregnancy and have the advantage of avoiding ionising radiation. However, the sensitivity of the FAST scan is reduced in pregnancy especially with advanced gestational age. Sensitivity of FAST scanning is 60-80% across all trimesters and 90% in the first. CT scanning remains the first line investigation in major trauma where significant visceral injury is suspected. The maximum permitted safe dose of radiation in pregnancy is 5mSv. A pelvic CT scan would fall below this level. That said, early exposure to radiation will increase the risk of developmental anomalies and foetal loss. Late exposure increases the risk of childhood cancer twofold. CT scanning remains the most sensitive test for identifying complications such as placental abruption in this group.

Answer 1327

The proximal convoluted tubule may undergo necrosis in situations such as compartment syndrome. It is responsible for reabsorbing up to two thirds of filtered water. Low systolic blood pressures (below the renal autoregulatory range) are a risk factor for acute tubular necrosis. Within the autoregulatory range the absolute value of systolic BP has little effect. The process of facilitated diffusion of glucose refers to its co-transport with sodium. Renal Physiology Overview Each nephron is supplied with blood from an afferent arteriole that opens onto the glomerular capillary bed. Blood then flows to an efferent arteriole, supplying the peritubular capillaries and medullary vasa recta. The kidney receives up to 25% of resting cardiac output. Control of blood flow The kidney is able to autoregulate its blood flow between systolic pressures of 80- 180mmHg so there is little variation in renal blood flow. This is achieved by myogenic control of arteriolar tone, both sympathetic input and hormonal signals (e.g. renin) are responsible. Glomerular structure and function Blood inside the glomerulus has considerable hydrostatic pressure. The basement membrane has pores that will allow free diffusion of smaller solutes, larger negatively charged molecules such as albumin are unable to cross. The glomerular filtration rate (GFR) is equal to the concentration of a solute in the urine, times the volume of urine produced per minute, divided by the plasma concentration (assuming that the solute is freely diffused e.g. inulin). In clinical practice creatinine is used because it is subjected to very little proximal tubular secretion. Although subject to variability, the typical GFR is 125ml per minute. Glomerular filtration rate = Total volume of plasma per unit time leaving the capillaries and entering the bowman's capsule Renal clearance = volume plasma from which a substance is removed per minute by the kidneys Substances used to measure GFR have the following features: 1. Inert 2. Free filtration from the plasma at the glomerulus (not protein bound) 3. Not absorbed or secreted at the tubules 4. Plasma concentration constant during urine collection Examples: inulin, creatinine GFR = urine concentration (mmol/l) x urine volume (ml/min) -------------------------------------------------------------------------- plasma concentration (mmol/l) The clearance of a substance is dependent not only on its diffusivity across the basement membrane but also subsequent tubular secretion and / or reabsorption. So glucose which is freely filtered across the basement membrane is usually reabsorbed from tubules giving a clearance of zero. Tubular function Reabsorption and secretion of substances occurs in the tubules. In the proximal tubule substrates such as glucose, amino acids and phosphate are co-transported with sodium across the semi permeable membrane. Glucose is reabsorbed by both active and passive processes. The former uses sodiumâ€“glucose co-transporters (SGLTs) in the proximal convoluted tubule. The latter achieved through facilitated and passive process through GLUT transporters. Up to two thirds of filtered water is reabsorbed in the proximal tubules. This will lead to increase in urea concentration in the distal tubule allowing for its increased diffusion. Substances to be secreted into the tubules are taken up from the peritubular blood by tubular cells. Solutes such as paraaminohippuric acid are cleared with a single passage through the kidneys and this is why it is used to measure renal plasma flow. Ions such as calcium and phosphate will have a tubular reabsorption that is influenced by plasma PTH levels. Potassium may be both secreted and re-absorbed and is co-exchanged with sodium. Loop of Henle Approximately 60 litres of water containing 9000mmol sodium enters the descending limb of the loop of Henle in 24 hours. Loops from the juxtamedullary nephrons run deep into the medulla. The osmolarity of fluid changes and is greatest at the tip of the papilla. The thick ascending limb is impermeable to water, but highly permeable to sodium and chloride ions. This loss means that at the beginning of the thick ascending limb the fluid is hypo osmotic compared with adjacent interstitial fluid. In the thick ascending limb the reabsorption of sodium and chloride ions occurs by both facilitated and passive diffusion pathways. The loops of Henle are co-located with vasa recta, these will have similar solute compositions to the surrounding extracellular fluid so preventing the diffusion and subsequent removal of this hypertonic fluid. The energy dependent reabsorption of sodium and chloride in the thick ascending limb helps to maintain this osmotic gradient.

Answer 1328

Pectoralis minor is supplied by the medial pectoral nerve Pectoral muscles Pectoralis major Origin From the medial two thirds of the clavicle, manubrium and sternocostal angle Insertion Lateral edge of the bicipital groove of the humerus Nerve supply Medial and lateral pectoral nerves Actions Adductor and medial rotator of the humerus Pectoralis minor Origin Upper margins of third to fifth ribs and intercostal fascia Insertion Medial border and upper surface of the coracoid process Nerve supply Medial pectoral nerve Actions Assists serratus anterior in drawing scapula forwards and depresses the point of the shoulder

Answer 1329

This is a likely torsion so surgery cannot be deferred. Local anaesthetic scrotal exploration is likely to be very poorly tolerated. Delay of surgery and USS are not appropriate. Immediate exploration under GA with appropriate airway protection in place. Testicular disorders-paediatric Testicular disorders Testicular disorders are some of the commonest conditions present in paediatric urological practice. Cryptorchidism The embryological descent of the testicle from within the abdominal cavity may be subject to a number of variations. Distinctions need to be made clinically from a non descended testis and a testis that is retractile. Testis that lie outside the normal path of embryological descent are termed ectopic testis. Undescended testis occurs in 1% of male infants. Where the testis does not lie in an intra scrotal location, its location should be ascertained (by laparoscopy in first instance). Where both testes are absent, the infant may be intersex. MRI scanning may reveal intra-abdominal testes; however a GA is often needed to perform this investigation in this age group. Testes that are undescended should be placed in the scrotum after 1 year of age, as the testosterone surge that may facilitate descent occurs at 6 months of age. Where the testes lie distally e.g. Superficial inguinal pouch an open orchidopexy is the procedure of choice. With abdominal testes a laparoscopy should be performed. The risk of seminoma is increased in individuals with a non descended testes and this risk is not reduced by orchidopexy. Testicular torsion Typically the patient has severe sudden onset of scrotal pain. The difficulty in paediatric practice is the lack of clear history. On examination the testis is tender and enlarged. Management is by surgical exploration. Delay beyond 6 hours is associated with low salvage rates. A torted hyatid produces pain that is far more localised and the testis itself should feel normal. However, diagnostic doubt often exists and in such cases surgical exploration is warranted. Hydrocele Occur secondary to patent processus vaginalis Present as fluid filling in scrotum or as cyst of the spermatic cord Communicating hydroceles are treated by a trans inguinal ligation of the PPV Cystic hydroceles in older children may be treated with scrotal exploration

Answer 1330

D-Mandibular branch of trigeminal nerve Structures passing through the parotid gland Facial nerve and branches External carotid artery (and its branches; the maxillary and superficial temporal) Retromandibular vein Auriculotemporal nerve The mandibular nerve is well separated from the parotid gland. The maxillary vein joins to the superficial temporal vein and they form the retromandibular vein which then runs through the parotid gland. The auriculotemporal nerve runs through the gland. Following a parotidectomy this nerve may be damaged and during neuronal regrowth may then attach to sweat glands in this region. This can then cause gustatory sweating (Freys Syndrome). The facial nerve branch is the marginal mandibular branch and this is related to the gland.

Answer 1331

Hypospadias most commonly occurs as an isolated disorder. Associated urological abnormalities may be seen in up to 40% of infants, of these cryptorchidism is the most frequent (10%). Hypospadias The urethral meatus opens on the ventral surface of the penis. There is also a ventral deficiency of the foreskin. The urethral meatus may open more proximally in the more severe variants. However, 75% of the openings are distally located. The incidence is 1 in 300 male births. Features include: Absent frenular artery Ventrally opened glans Skin tethering to hypoplastic urethra Splayed columns of spongiosum tissue distal to the meatus Deficiency of the foreskin ventrally Management: No routine cultural circumcisions Urethroplasty Penile reconstruction The foreskin is often utilised in the reconstructive process. In boys with very distal disease no treatment may be needed.

Answer 1332

CSF leaves the 4th ventricle via the laterally placed foramen of Luschka and also via the midline foramen of Magendie. Cerebrospinal fluid The CSF fills the space between the arachnoid mater and pia mater (covering surface of the brain). The total volume of CSF in the brain is approximately 150ml. Approximately 500 ml is produced by the ependymal cells in the choroid plexus (70%), or blood vessels (30%). It is reabsorbed via the arachnoid granulations which project into the venous sinuses. Circulation 1. Lateral ventricles (via foramen of Munro) 2. 3rd ventricle 3. Cerebral aqueduct (aqueduct of Sylvius) 4. 4th ventricle 5. Subarachnoid space (via foramina of Magendie and Luschka) 6. Reabsorbed into the venous system via arachnoid granulations into superior sagittal sinus Composition Glucose: 50-80mg/dl Protein: 15-40 mg/dl Red blood cells: Nil White blood cells: 0-3 cells/ mm3

Answer 1333

C-Thyroidea ima artery Other occasional branches include the thymic and bronchial branch. Brachiocephalic artery The brachiocephalic artery is the largest branch of the aortic arch. From its aortic origin it ascends superiorly, it initially lies anterior to the trachea and then on its right hand side. It branches into the common carotid and right subclavian arteries at the level of the sternoclavicular joint. Path Origin- apex of the midline of the aortic arch Passes superiorly and posteriorly to the right Divides into the right subclavian and right common carotid artery Relations Anterior Sternohyoid Sternothyroid Thymic remnants Left brachiocephalic vein Right inferior thyroid veins Posterior Trachea Right pleura Right lateral Right brachiocephalic vein Superior part of SVC Left lateral Thymic remnants Origin of left common carotid Inferior thyroid veins Trachea (higher level) Branches Normally none but may have the thyroidea ima artery

Answer 1334

Hassall's corpuscles are the concentric ring of epithelial cells seen in the medulla of the thymus. Thymus The thymus develops from the third and fourth pharyngeal pouches. It descends to lie in the anterior superior mediastinum. It is encapsulated and is subdivided into lobules, these consist of a cortex and a medulla. The cortex is composed of tightly packed lymphocytes, the medulla consists largely of epithelial cells. The medullary epithelial cells are concentrically arranged and may surround a keratinised centre, known as Hassall's corpuscles. The inferior parathyroid glands also develop from the third pharyngeal pouch and may also be located with the thymus gland. Its arterial supply is from the internal mammary artery or pericardiophrenic arteries. Venous drainage is to the left brachiocephalic vein. Hassall's corpuscles stained with H+E

Answer 1335

Spinothalamic tract- Pain and temperature Vestibulospinal tract- Motor neuronal signals relating to posture Cuneate fasciculus- Fine touch, pressure and proprioception Posterior spinocerebellar tract- Proprioceptive signals to cerebellum Anterior corticospinal tract- Conveys motor signals from precentral gyrus to motor cells within the cord Pain impulses are transmitted via the spinothalamic tract Spinothalamic tract The spinothalamic tract transmits impulses from receptors which measure crude touch, pain and temperature. The spinothalamic tract comprises the lateral and anterior spinothalamic tracts, the former typically transmits pain and temperature and the latter crude touch and pressure. Neurones transmitting these signals will typically ascend by one or two vertebral levels in Lissaurs tract prior to decussating in the spinal cord itself. Neurones then pass rostrally in the cord to connect at the thalamus.

Answer 1336

p53 is a tumour supressor gene and located on chromosome 17. It plays an important role in causing cells that are undergoing neoplastic changes to enter an apoptotic pathway. Oncogenes Oncogenes are cancer promoting genes that are derived from normal genes (proto-oncogenes). Proto-oncogenes play an important physiological role in cellular growth. They are implicated in the development of up to 20% of human cancers. Proto-oncogenes may become oncogenes via the following processes: Mutation (point mutation) Chromosomal translocation Increased protein expression Only one mutated copy of the gene is needed for cancer to occur - a dominant effect Classification of oncogenes Growth factors e.g. Sis Transcription factors e.g. Myc Receptor tyrosine kinase e.g. RET Cytoplasmic tyrosine kinase e.g. Src Regulatory GTPases e.g. Ras Tumour suppressor genes Tumour suppressor genes restrict or repress cellular proliferation in normal cells. Their inactivation through mutation or germ line incorporation is implicated in renal, colonic, breast, bladder and many other cancers. One of the best known tumour suppressor genes is p53. p53 gene offers protection by causing apoptosis of damaged cells. Other well known genes include BRCA 1 and 2.

Answer 1337

Metoclopramide acts directly on the smooth muscle of the LOS to cause it to contract. Theophylline is a phosphodiesterase inhibitor (mimics action of prostaglandin E1) which causes relaxation of the LOS. Peristalsis Circular smooth muscle contracts behind the food bolus and longitudinal smooth muscle propels the food through the oesophagus Primary peristalsis spontaneously moves the food from the oesophagus into the stomach (9 seconds) Secondary peristalsis occurs when food, which doesn't enter the stomach, stimulates stretch receptors to cause peristalsis In the small intestine each peristalsis waves slows to a few seconds and causes mixture of chyme In the colon three main types of peristaltic activity are recognised (see below) Colonic peristalsis Segmentation contractions Localised contractions in which the bolus is subjected to local forces to maximise mucosal absorption Antiperistaltic contractions towards ileum Localised reverse peristaltic waves to slow entry into colon and maximise absorption Mass movements Waves migratory peristaltic waves along the entire colon to empty the organ prior to the next ingestion of food bolus

Answer 1338

The deep external pudendal artery runs under the long saphenous vein close to its origin and may be injured. It is at greatest risk of injury during the flush ligation of the saphenofemoral junction. Provided an injury is identified and vessel ligated, injury is seldom associated with any serious adverse sequelae. Saphenous vein Long saphenous vein This vein may be harvested for bypass surgery, or removed as treatment for varicose veins with saphenofemoral junction incompetence. Originates at the 1st digit where the dorsal vein merges with the dorsal venous arch of the foot Passes anterior to the medial malleolus and runs up the medial side of the leg At the knee, it runs over the posterior border of the medial epicondyle of the femur bone Then passes laterally to lie on the anterior surface of the thigh before entering an opening in the fascia lata called the saphenous opening It joins with the femoral vein in the region of the femoral triangle at the saphenofemoral junction Tributaries Medial marginal Superficial epigastric Superficial iliac circumflex Superficial external pudendal veins Short saphenous vein Originates at the 5th digit where the dorsal vein merges with the dorsal venous arch of the foot, which attaches to the great saphenous vein. It passes around the lateral aspect of the foot (inferior and posterior to the lateral malleolus) and runs along the posterior aspect of the leg (with the sural nerve) Passes between the heads of the gastrocnemius muscle, and drains into the popliteal vein, approximately at or above the level of the knee joint.

Answer 1339

The trigeminal nerve is the major sensory nerve to the face except over the angle of the jaw. The angle of the jaw is innervated by the greater auricular nerve. Trigeminal nerve The trigeminal nerve is the main sensory nerve of the head. In addition to its major sensory role, it also innervates the muscles of mastication. Distribution of the trigeminal nerve Sensory Scalp Face Oral cavity (and teeth) Nose and sinuses Dura mater Motor Muscles of mastication Mylohyoid Anterior belly of digastric Tensor tympani Tensor palati Autonomic connections (ganglia) Ciliary Sphenopalatine Otic Submandibular Path Originates at the pons Sensory root forms the large, crescentic trigeminal ganglion within Meckel's cave, and contains the cell bodies of incoming sensory nerve fibres. Here the 3 branches exit. The motor root cell bodies are in the pons and the motor fibres are distributed via the mandibular nerve. The motor root is not part of the trigeminal ganglion. Branches of the trigeminal nerve Ophthalmic nerve Sensory only Maxillary nerve Sensory only Mandibular nerve Sensory and motor Sensory Ophthalmic Exits skull via the superior orbital fissure Sensation of: scalp and forehead, the upper eyelid, the conjunctiva and cornea of the eye, the nose (including the tip of the nose, except alae nasi), the nasal mucosa, the frontal sinuses, and parts of the meninges (the dura and blood vessels). Maxillary nerve Exit skull via the foramen rotundum Sensation: lower eyelid and cheek, the nares and upper lip, the upper teeth and gums, the nasal mucosa, the palate and roof of the pharynx, the maxillary, ethmoid and sphenoid sinuses, and parts of the meninges. Mandibular nerve Exit skull via the foramen ovale Sensation: lower lip, the lower teeth and gums, the chin and jaw (except the angle of the jaw), parts of the external ear, and parts of the meninges. Motor Distributed via the mandibular nerve. The following muscles of mastication are innervated: Masseter Temporalis Medial pterygoid Lateral pterygoid Other muscles innervated include: Tensor veli palatini Mylohyoid Anterior belly of digastric Tensor tympani

Answer 1340

Viral illnesses can be associated with transient synovitis. The WCC should ideally be > 12 and the ESR > 40 to suggest septic arthritis. Paediatric orthopaedics Diagnosis Mode of presentation Treatment Radiology Developmental dysplasia of the hip Usually diagnosed in infancy by screening tests. May be bilateral, when disease is unilateral there may be leg length inequality. As disease progresses child may limp and then early onset arthritis. More common in extended breech babies. Splints and harnesses or traction. In later years osteotomy and hip realignment procedures may be needed. In arthritis a joint replacement may be needed. However, this is best deferred if possible as it will almost certainly require revision Initially no obvious change on plain films and USS gives best resolution until 3 months of age. On plain films Shentons line should form a smooth arc Perthes Disease Hip pain (may be referred to the knee) usually occurring between 5 and 12 years of age. Bilateral disease in 20%. Remove pressure from joint to allow normal development. Physiotherapy. Usually self-limiting if diagnosed and treated promptly. X-rays will show flattened femoral head. Eventually in untreated cases the femoral head will fragment. Slipped upper femoral epiphysis Typically seen in obese male adolescents. Pain is often referred to the knee. Limitation to internal rotation is usually seen. Knee pain is usually present 2 months prior to hip slipping. Bilateral in 20%. Bed rest and non-weight bearing. Aim to avoid avascular necrosis. If severe slippage or risk of it occurring then percutaneous pinning of the hip may be required. X-rays will show the femoral head displaced and falling inferolaterally (like a melting ice cream cone) The Southwick angle gives indication of disease severity

Answer 1341

This man is malnourished, although he is likely to require surgery it is best for him to be nutritionally optimised first. As he may have reduced surface area for absorption and has a localised perforation TPN is likely to be the best feeding modality. Parenteral feeding-NICE guidelines Parenteral nutrition: NICE guidelines summary Identify patients as malnourished or at risk Patients identified as being malnourished- BMI < 18.5 kg/m2 unintentional weight loss of > 10% over 3-6/12 BMI < 20 kg/m2 and unintentional weight loss of > 5% over 3-6/12 AT RISK of malnutrition- eaten nothing or little > 5 days, who are likely to eat little for a further 5 days poor absorptive capacity high nutrient losses high metabolism Identify unsafe/inadequate oral intake OR a non functional GI tract/perforation/inaccessible Consider parenteral nutrition: for feeding < 14 days consider feeding via a peripheral venous catheter for feeding > 30 days use a tunneled subclavian line continuous administration in severely unwell patients if feed needed > 2 weeks consider changing from continuous to cyclical feeding don't give > 50% of daily regime to unwell patients in first 24-48 hours Surgical patients: if malnourished with unsafe swallow OR a non functional GI tract/perforation/inaccessible then consider peri operative parenteral feeding.

Answer 1342

Neo-intimal hyperplasia in distal arterial anastamoses may be reduced by use of a Miller Cuff when PTFE is the bypass conduit. PTFE may induce neo-intimal hyperplasia with subsequent occlusion of the distal anastomosis. In more proximal arterial bypass surgery the process of neo-intimal hyperplasia is not sufficient to cause anastomotic occlusion. However, distal bypasses are at greater risk and if vein cannot be used as a conduit then the distal end of the PTFE should anastomosed to a vein cuff to minimise the risk of neo-intimal hyperplasia. Anastomoses - A wide variety of anastomoses are constructed in surgical practice. Essentially the term refers to the restoration of luminal continuity. As such they are a feature of both abdominal and vascular surgery. Visceral anastomoses For an anastomosis to heal three criteria need to be fulfilled: Adequate blood supply Mucosal apposition Minimal tension When these are compromised the anastomosis may break down. Even in the best surgical hands some anastomoses are more prone to dehiscence than others. Oesophageal and rectal anastomoses are more prone to leakage and reported leak rates following oesophageal and rectal surgery can be as high as 20%. This figure includes radiological leaks and those with a clinically significant leak will be of a lower order of magnitude. As a rule small bowel anastomoses heal most reliably. The decision as to how best to achieve mucosal apposition is one for each surgeon. Some will prefer the use of stapling devices as they are quicker to use, others will prefer to perform a sutured anastomosis. The attention to surgical technique is more important than the method chosen and a poorly constructed stapled anastomosis in thickened tissue is far more prone to leakage than a hand sewn anastomosis in the same circumstances. If an anastomosis looks unsafe then it may be best not to construct one at all. In colonic surgery this is relatively clear cut and most surgeons would bring out an end colostomy. In situations such as oesophageal surgery this is far more problematic and colonic interposition may be required in this situation. Vascular anastomoses Most arterial surgery involving bypasses or aneurysm repairs will require construction of an arterial anastomosis. Technique is important and for small diameter distal arterial surgery the intimal hyperplasia resulting from a badly constructed anastomosis may render the whole operation futile before the patient leaves hospital. Some key points about vascular anastomoses: Always use non absorbable monofilament suture (e.g. Polypropylene). Round bodied needle. Correct size for anastamosis ( i.e. 6/0 prolene for bottom end of a femoro-distal bypass). Suture should be continuous and from inside to outside of artery to avoid raising an intimal flap.

Answer 1343

This is a relatively clear indication for a punch biopsy. If cellular atypia is present on punch biopsy then any in situ malignancy should be considered. FNAC would be unsuitable. Tissue sampling Tissue sampling is an important surgical process. Biopsy modalities vary according to the site, experience and subsequent planned therapeutic outcome The modalities comprise: -Fine needle aspiration cytology -Core biopsy -Excision biopsy -Tru cut biopsy -Punch biopsy -Cytological smears -Endoscopic or laparoscopic biopsy When the lesion is superficial the decision needs to be taken as to whether complete excision is desirable or whether excision biopsy is acceptable. In malignant melanoma for example the need for safe margins will mean that a more radical surgical approach needs to be adopted after diagnostic confirmation from excision biopsy than would be the case in basal cell carcinoma. Punch biopsies are useful in gaining histological diagnosis of unclear skin lesions where excision biopsy is undesirable such as in establishing whether a skin lesion is vasculitic or not. Fine needle aspiration cytology (FNAC) is an operator dependent procedure that may or may not be image guided and essentially involves passing a needle through a lesion whilst suction is applied to a syringe. The material thus obtained is expressed onto a slide and sent for cytological assessment. This test can be limited by operator inexperience and also by the lack of histological architectural information (e.g. Follicular carcinoma of the thyroid). Where a discharge is present a sample may be sent for cytology although in some sites (e.g. Nipple discharge ) the information gleaned may be meaningless. Tissue samples may be obtained by both core and tru cut biopsy. A core biopsy is obtained by use of a spring loaded gun with a needle passing quickly through the lesion of interest. A tru cut biopsy achieves the same objective but the needle moved by hand. When performing these techniques image guidance may be desirable (e.g. In breast lesions). Consideration needs to be given to any planned surgical resection as it may be necessary to resect the biopsy tract along with the specimen (e.g. In sarcoma surgery). Visceral lesions may be accessed percutaneously under image guidance such as ultrasound guided biopsy of liver metastases. Or under direct vision such as a colonoscopic biopsy.

Answer 1344

Its an anterior pituitary lesion and that is the reason thyroxine secretion is affected. ADH is released by the posterior pituitary. Pituitary Gland The pituitary gland is located within the sella turcica within the sphenoid bone in the middle cranial fossa. It is covered by a dural fold and weighs around 0.5g. It is attached to the hypothalamus by the infundibulum. The anterior pituitary receives hormonal stimuli from the hypothalamus by way of the hypothalamo-pituitary portal system. It develops from a depression in the wall of the pharynx (Rathkes pouch). Anterior pituitary hormones Growth hormone Thyroid stimulating hormone ACTH Prolactin LH and FSH Melanocyte releasing hormone Posterior pituitary hormones Oxytocin Anti diuretic hormone

Answer 1345

Ghon focus is primary infection Ghon complex is primary infection and regional nodal involvement Tuberculosis pathology Is a form of primary chronic inflammation, caused by the inability of macrophages to kill the Mycobacterium tuberculosis. The macrophages often migrate to regional lymph nodes, the lung lesion plus affected lymph nodes is referred to as a Ghon complex. This leads to the formation of a granuloma which is a collection of epithelioid histiocytes. There is the presence of caseous necrosis in the centre. The inflammatory response is mediated by a type 4 hypersensitivity reaction. In healthy individuals the disease may be contained, in the immunocompromised disseminated (miliary TB) may occur. Diagnosis Waxy membrane of mycobacteria prevents binding with normal stains. Ziehl - Neelsen staining is typically used. Culture based methods take far longer.

Answer 1346

This patient has an acute respiratory acidosis, however this is on a background of chronic respiratory acidosis (due to COPD) with a compensatory metabolic alkalosis (the elevated bicarbonate is the main clue to the chronic nature of the respiratory acidosis). This blood gas picture is typical in a COPD patient who has received too much oxygen; these patients lose their hypoxic drive for respiration, therefore retain CO2 and subsequently hypoventilate leading to respiratory arrest. If the bicarbonate was normal, then the answer would be acute respiratory acidosis secondary to pneumonia. Arterial blood gas interpretation In advanced life support training, a 5 step approach to arterial blood gas interpretation is advocated. 1. How is the patient? 2. Is the patient hypoxaemic? The Pa02 on air should be 10.0-13.0 kPa 3. Is the patient acidaemic (pH <7.35) or alkalaemic (pH >7.45) 4. What has happened to the PaCO2? If there is acidaemia, an elevated PaCO2 will account for this 5. What is the bicarbonate level or base excess? A metabolic acidosis will have a low bicarbonate level and a low base excess (< -2 mmol) A metabolic alkalosis will have a high bicarbonate and a high base excess (> +2 mmol)

Answer 1347

Necrotising enterocolitis often has a delayed presentation and affected infants will typically pass bloody stools. Plain films may show air in the intestinal wall (Pneumatosis). Bilious vomiting in neonates Causes of intestinal obstruction with bilious vomiting in neonates Disorder Incidence and causation Age at presentation Diagnosis Treatment Duodenal atresia 1 in 5000 (higher in Downs syndrome) Few hours after birth AXR shows 'double bubble sign, contrast study may confirm Duodenoduodenostomy Malrotation with volvulus Usually cause by incomplete rotation during embryogenesis Usually 3-7 days after birth, volvulus with compromised circulation may result in peritoneal signs and haemodynamic instability Upper GI contrast study may show DJ flexure is more medially placed, USS may show abnormal orientation of SMA and SMV Ladd's procedure Jejunal/ ileal atresia Usually caused by vascular insufficiency in utero, usually 1 in 3000 Usually within 24 hours of birth AXR will show air-fluid levels Laparotomy with primary resection and anastomosis Meconium ileus Occurs in between 15 and20% of those babies with cystic fibrosis, otherwise 1 in 5000 Typically in first 24-48 hours of life with abdominal distension and bilious vomiting Air - fluid levels on AXR, sweat test to confirm cystic fibrosis Surgical decompression, serosal damage may require segmental resection Necrotising enterocolitis Up to 2.4 per 1000 births, risks increased in prematurity and inter-current illness Usually second week of life Dilated bowel loops on AXR, pneumatosis and portal venous air Conservative and supportive for non perforated cases, laparotomy and resection in cases of perforation of ongoing clinical deterioration

Answer 1348

Alagille syndrome autosomal dominant disorder characterised by presence of paucity of bile ducts and cardiac defects. Only the embryonic form of biliary atresia is associated with cardiac and other embryological defects. Biliary atresia usually presents with obstructed jaundice. A Kasai procedure is best performed in the first 8 weeks of life. If a Kasai procedure is successful most patients will not require liver transplantation. 45% of patients post Kasai procedure will require transplantation. However, overall survival following a successful Kasai procedure is 80%. Biliary atresia 1 in 17000 affected Biliary tree lumen is obliterated by an inflammatory cholangiopathy causing progressive liver damage Clinical features Infant well in 1st few weeks of life No family history of liver disease Jaundice in infants > 14 days in term infants (>21 days in pre term infants) Pale stool, yellow urine (colourless in babies) Associated with cardiac malformations, polysplenia, situs inversus Investigation Conjugated bilirubin (prolonged physiological jaundice or breast milk jaundice will cause a rise in unconjugated bilirubin, whereas those with obstructive liver disease will have a rise in conjugated bilirubin) Ultrasound of the liver (excludes extrahepatic causes, in biliary atresia infant may have tiny or invisible gallbladder) Hepato-iminodiacetic acid radionuclide scan (good uptake but no excretion usually seen) Management Early recognition is important to prevent liver transplantation. Nutritional support. Roux-en-Y portojejunostomy (Kasai procedure). If Kasai procedure fails or late recognition, a liver transplant becomes the only option.

Answer 1349

Hemiarthroplasty is offered to older, less mobile individuals compared to fracture reduction and fixation in younger patients. Hip fractures Background Neck of femur (NOF) fracture is a common orthopaedic presentation, with over 65000 fractures in the UK per year. Like many orthopaedic injuries, there is a bimodal age distribution. It is imperative to distinguish between the high energy injury in a young patient, and the low energy osteoporotic fracture in the elderly, as their management aims are very different: Young patient - Usually high energy trauma (e.g road traffic accident, horse riding) and needs treating in accordance with Advanced Trauma Life Support (ATLS) principles. Will often have associated injuries. Aim is to retain the patients own anatomy, and optimise their function. Elderly patient - Predominantly female, fall from standing height (fragility fracture). Often patients have multiple comorbidities that will ultimately dictate their prognosis. Aim of orthopaedic treatment is to immediately regain patient mobility so that morbidity (infection, thromboembolic events, pressure sores etc) and mortality associated with prolonged bed rest is avoided. Left untreated, a neck of femur fracture can be considered a terminal event. Historically, mortality associated with elderly hip fracture is 10% at one month, and 30% at one year. However, this has been improved in the UK with the introduction of multidisciplinary, orthogeriatric lead care and the National Hip Fracture Database and Best Practice Tariff. Pertinent anatomy Osteology - normal neck-shaft angle is 130 +/- 7 degrees, and 10 +/- 7 degrees of neck anteversion. Vascular supply - The predominant blood supply to the femoral head and neck is from the medial and lateral femoral circumflex arteries (branches of profunda femoris). These anastomose and pierce the joint capsule at the base of the neck, mainly posteriorly. There is a small vascular contribution from the artery of the ligament teres. Understanding the blood supply is fundamental to the decision making process in treating NOF fractures. Presentation and initial management Typically, patients present with pain in the hip/groin, a shortened, abducted, externally rotated leg (due to the unopposed pull of the muscles that act across the hip joint) and the inability to straight-leg-raise. With undisplaced fractures, signs are more subtle. High energy injuries should be treated in line with ATLS principles. All patients should be fluid resuscitated, have adequate pain relief (often with a fascio-iliiaca nerve block), and be optimised for surgery. In addition, elderly patients should be assessed by an orthogeriatrician. Imaging Anteroposterior and cross-table lateral plain radiographs are sufficient to diagnose the majority of NOF fractures. If the fracture extends below the level of the lesser trochanter, or there is any possibility of pathological fracture, full length femur views are essential to plan surgery. Where there is a high index of suspicion of fracture, but plain radiographs are inconclusive, gold standard investigation is MRI. However, if unavailable within 24 hours, or if the patient will not tolerate MRI, CT is appropriate. The majority of fractures can be seen with modern CT techniques, and so this is becoming first line in many hospitals. Classification There has been a move away from named classification systems towards descriptive classification systems. Two main types of NOF exist: Intra-capsular, and extra-capsular. Extra-capsular fractures are further divided into pertrochanteric or subtrochanteric (within 5cm distal to the lesser trochanter). All fractures are then described as undisplaced, minimally displaced, or displaced. Femoral neck and head blood supply disruption is common with intracapsular NOF fractures, and rare with extracapsular fractures. This fundamental principle underpins the practise of arthroplasty for intracapsular fractures, and fixation for extracapsular fractures. If you wish to use a named classification system, the most commonly used are below: Elderly intracapsular - Garden Classification Young intrasapsular - Pauvels Classification Intertrochanteric - Evans Subtrochanteric - Russell Taylor Treatment In general, NOF fractures are treated operatively except if the patient is deemed unlikely to survive an anaesthetic. Best Practice Tarif (BPT) dictates that surgery should happen within 36 hours, as delay of greater than 48 hours is associated with increased morbidity and mortality. Below are suggested algorithms for the treatment of NOF. * The priority with the young patient is to retain the femoral head if possible, even with a displaced intracapsular fracture. The risk of avascular necrosis and non-union (and therefore revision surgery) associated with internal fixation needs weighing up against the sequelae of total hip replacement in the young (wear, dislocation, revision). Discussion is necessary with the patient, on a case by case basis. ** Undisplaced fractures in the elderly can be treated with internal fixation, often with cannulated screws. This is appropriate for valgus impacted subcapital fractures which are inherently stable, to prevent secondary displacement. This does still carry the risk of AVN or non-union, and therefore a future revision. For this reason, many surgeons advocate arthroplasty as a single surgery. *** NICE guidance - patients who fulfil these criteria should be offered total hip replacement which conveys better function and prosthetic survivorship, compared with hemiarthroplasty, but at an increased risk of dislocation. * Intertrochanteric fractures vary greatly in their stability. If the trochanter (and therefore lateral wall), and medial calcar is in tact, then the fracture configuration bears stability. This can be treated with a DHS, as collapse of the fracture is predictable. Where either or both structures are involved in the fracture, stability becomes compromised and many surgeons will favour using an intramedullary device. This is an ongoing debate, and difficult to test in an exam setting. Post operative management Patients should be mobilised fully weight bearing where possible. Care is multidisciplinary in its delivery. Elderly patients should have orthogeriatrician assessment of comorbidity, and bone health with secondary prevention measures if appropriate. There should be early involvement of physiotherapy and occupational therapy services. For further guidance see sources listed below. NICE clinical guidance on hip fracture: https://www.nice.org.uk/guidance/cg124 Best Practice Tarif: www.nhfd.co.uk/20/hipfractureR.../Best%20Practice%20Tariff%20User%20Guide.pdf National Hip Fracture Database: www.nhfd.co.uk/

Answer 1350

Wilm's tumour of the kidney is the most common renal tumour in children. Both nephroblastoma and neuroblastoma may occupy the adrenal and apex of the kidney. In the case of neuroblastoma the lesion will have arisen from the adrenal, in the case of nephroblastoma the lesion will have arisen from the kidney. Hypertension is more commonly associated with nephroblastoma. Neuroblastomas are usually calcified, whereas nephroblastomas are not and this may be of diagnostic usefulness pre operatively. Renal lesions Lesion Disease specific features Treatment Renal cell carcinoma Most present with haematuria (50%) Common renal tumour (85% cases) Paraneoplastic features include hypertension and polycythaemia Most commonly has haematogenous mestastasis Usually radical or partial nephrectomy Nephroblastoma Rare childhood tumour It accounts for 80% of all genitourinary malignancies in those under the age of 15 years Up to 90% will have a mass 50% will be hypertensive Diagnostic work up includes ultrasound and CT scanning Surgical resection combined with chemotherapy (usually vincristine, actinomycin D and doxorubicin) Neuroblastoma Most common extracranial tumour of childhood 80% occur in those under 4 years of age Tumour of neural crest origin (up to 50% occur in the adrenal gland) The tumour is usually calcified and may be diagnosed using MIBG scanning Staging is with CT Surgical resection, radiotherapy and chemotherapy Transitional cell carcinoma Accounts for 90% of lower urinary tract tumours, but only 10% of renal tumours Males affected 3x more than females Occupational exposure to industrial dyes and rubber chemicals may increase risk Up to 80% present with painless haematuria Diagnosis and staging is with CT IVU Radical nephroureterectomy Angiomyolipoma 80% of these hamartoma type lesions occur sporadically, the remainder are seen in those with tuberous sclerosis Tumour is composed of blood vessels, smooth muscle and fat Massive bleeding may occur in 10% of cases 50% of patients with lesions >4cm will have symptoms and will require surgical resection

Answer 1351

Adductor longus forms the medial boundary of the femoral triangle (see below). Femoral triangle anatomy Boundaries Superiorly Inguinal ligament Laterally Sartorius Medially Adductor longus Floor Iliopsoas, adductor longus and pectineus Roof Fascia lata and Superficial fascia Superficial inguinal lymph nodes (palpable below the inguinal ligament) Long saphenous vein Contents Femoral vein (medial to lateral) Femoral artery-pulse palpated at the mid inguinal point Femoral nerve Deep and superficial inguinal lymph nodes Lateral cutaneous nerve Great saphenous vein Femoral branch of the genitofemoral nerve

Answer 1352

In this situation the most likely diagnosis is primary hyperparathyroidism. The question mentions that serum urea and electrolytes are normal, which makes tertiary hyperparathyroidism unlikely. Primary hyperparathyroidism In exams, primary hyperparathyroidism is stereotypically seen in elderly females with an unquenchable thirst and an inappropriately normal or raised parathyroid hormone level. It is most commonly due to a solitary adenoma Causes of primary hyperparathyroidism 80%: solitary adenoma 15%: hyperplasia 4%: multiple adenoma 1%: carcinoma Features - 'bones, stones, abdominal groans and psychic moans' Polydipsia, polyuria Peptic ulceration/constipation/pancreatitis Bone pain/fracture Renal stones Depression Hypertension Associations Hypertension Multiple endocrine neoplasia: MEN I and II Investigations Raised calcium, low phosphate PTH may be raised or normal Technetium-MIBI subtraction scan Treatment Parathyroidectomy, if imaging suggests target gland then a focused approach may be used

Answer 1353

Cavernous sinus syndrome is most commonly caused by cavernous sinus tumours. In this case, the nasopharyngeal malignancy has locally invaded the left cavernous sinus. Diagnosis is based on signs of pain, opthalmoplegia, proptosis, trigeminal nerve lesion (opthalmic branch) and Horner's syndrome. Cavernous sinus The cavernous sinuses are paired and are situated on the body of the sphenoid bone. It runs from the superior orbital fissure to the petrous temporal bone. Relations Medial Lateral Pituitary fossa Sphenoid sinus Temporal lobe Contents Lateral wall components (from top to bottom:) Oculomotor nerve Trochlear nerve Ophthalmic nerve Maxillary nerve Contents of the sinus (from medial to lateral:) Internal carotid artery (and sympathetic plexus) Abducens nerve Blood supply Ophthalmic vein, superficial cortical veins, basilar plexus of veins posteriorly. Drains into the internal jugular vein via: the superior and inferior petrosal sinuses

Answer 1354

Antibodies to thyroid peroxidase are found in most patients with Graves disease or Hashimotos thyroiditis. Blood testing in thyroid disease Assay Usage Thyroid peroxidase (microsomal) antibodies Found in autoimmune disease affecting the thyroid (Hashimotos 100%) and Graves (70%) Antibodies to TSH receptor Individuals with Graves disease (95%) Thyroglobulin Not useful for clinically distinguishing between different types of thyroid disease, may be used as part of thyroid cancer follow up Calcitonin Released from the parafollicular cells Usually found in patients with medullary carcinoma of the thyroid

Answer 1355

Remember that with impairment of flow through the portal system. The feeding vessels will be the gastric veins and drainage superiorly to the azygos system (i.e. reverse flow). Oesophagus - 25cm long Starts at C6 vertebra, pierces diaphragm at T10 and ends at T11 Squamous epithelium Constrictions of the oesophagus Structure Distance from incisors Cricoid cartilage 15cm Arch of the Aorta 22.5cm Left principal bronchus 27cm Diaphragmatic hiatus 40cm Relations Anteriorly Trachea to T4 Recurrent laryngeal nerve Left bronchus, Left atrium Diaphragm Posteriorly Thoracic duct to left at T5 Hemiazygos to the left T8 Descending aorta First 2 intercostal branches of aorta Left Thoracic duct Left subclavian artery Right Azygos vein Arterial, venous and lymphatic drainage of the oesophagus Artery Vein Lymphatics Muscularis externa Upper third Inferior thyroid Inferior thyroid Deep cervical Striated muscle Mid third Aortic branches Azygos branches Mediastinal Smooth & striated muscle Lower third Left gastric Left gastric Gastric Smooth muscle Nerve supply Upper half is supplied by recurrent laryngeal nerve Lower half by oesophageal plexus (vagus) Histology Mucosa :Non-keratinized stratified squamous epithelium Submucosa: glandular tissue Muscularis externa (muscularis): composition varies. See table Adventitia

Answer 1356

Thyroid lymphoma (Non Hodgkin's B cell lymphoma) is rare. It should be considered in patients with a background of Hashimoto's thyroiditis and a rapid growth in size of the thyroid gland. Diagnosis can be made with core needle biopsy; however an incisional biopsy may be needed. Radiotherapy is the main treatment option. Thyroiditis Sub acute thyroiditis Subacute thyroiditis (also known as De Quervain's thyroiditis) is thought to occur following viral infection and typically presents with hyperthyroidism Features Hyperthyroidism Painful goitre Raised ESR Globally reduced uptake on iodine-131 scan Management Usually self-limiting - most patients do not require treatment Thyroid pain may respond to aspirin or other NSAIDs In more severe cases steroids are used, particularly if hypothyroidism develops Hashimotos thyroiditis Hashimotos thyroiditis is an immunological disorder in which lymphocytes become sensitised to thyroidal antigens. The three most important antibodies include; thyroglobulin, TPO and TSH-R. During the early phase of Hashimotos the the thyroglobulin antibody is markedly elevated and then declines. Features Goitre and either euthyroid or mild hypothyroidism Progressive hypothyroidism (and associated symptoms) Management During the hyperthyroid phase of illness beta blockers may manage symptoms As hypothyroidism develops patients may require thyroxine

Answer 1357

Diverticulitis may result in a number of complications. However, whilst malignant disease may coincide with diverticulitis it is not, in itself, a risk factor for colonic cancer. Diverticular disease Diverticular disease is a common surgical problem. It consists of herniation of colonic mucosa through the muscular wall of the colon. The usual site is between the taenia coli where vessels pierce the muscle to supply the mucosa. For this reason, the rectum, which lacks taenia, is often spared. Symptoms Altered bowel habit Bleeding Abdominal pain Complications Diverticulitis Haemorrhage Development of fistula Perforation and faecal peritonitis Perforation and development of abscess Development of diverticular phlegmon Diagnosis Patients presenting in clinic will typically undergo either a colonoscopy, CT cologram or barium enema as part of their diagnostic work up. All tests can identify diverticular disease. It can be far more difficult to confidently exclude cancer, particularly in diverticular strictures. Acutely unwell surgical patients should be investigated in a systematic way. Plain abdominal films and an erect chest x-ray will identify perforation. An abdominal CT scan (not a CT cologram) with oral and intravenous contrast will help to identify whether acute inflammation is present but also the presence of local complications such as abscess formation. Severity Classification- Hinchey I Para-colonic abscess II Pelvic abscess III Purulent peritonitis IV Faecal peritonitis Treatment Increase dietary fibre intake. Mild attacks of diverticulitis may be managed conservatively with antibiotics. Peri colonic abscesses should be drained either surgically or radiologically. Recurrent episodes of acute diverticulitis requiring hospitalisation are a relative indication for a segmental resection. Hinchey IV perforations (generalised faecal peritonitis) will require a resection and usually a stoma. This group have a very high risk of post operative complications and usually require HDU admission.

Answer 1358

Tracheostomy is often used to facilitate long term weaning. The percutaneous devices are popular. These involve a seldinger type insertion of the tube. A second operator inserts a bronchoscope to ensure the device is not advanced through the posterior wall of the trachea. Complications include damage to adjacent structures and bleeding (contra indication in coagulopathy). Airway management Oropharyngeal airway Easy to insert and use No paralysis required Ideal for very short procedures Most often used as bridge to more definitive airway Laryngeal mask Widely used Very easy to insert Device sits in pharynx and aligns to cover the airway Poor control against reflux of gastric contents Paralysis not usually required Commonly used for wide range of anaesthetic uses, especially in day surgery Not suitable for high pressure ventilation (small amount of PEEP often possible) Tracheostomy Reduces the work of breathing (and dead space) May be useful in slow weaning Percutaneous tracheostomy widely used in ITU Dries secretions, humidified air usually required Endotracheal tube Provides optimal control of the airway once cuff inflated May be used for long or short term ventilation Errors in insertion may result in oesophageal intubation (therefore end tidal CO2 usually measured) Paralysis often required Higher ventilation pressures can be used

Answer 1359

Severe abdominal pain tends to favour Campylobacter infection. Diarrhoea World Health Organisation definitions Diarrhoea: > 3 loose or watery stool per day Acute diarrhoea < 14 days Chronic diarrhoea > 14 days Acute Diarrhoea Gastroenteritis May be accompanied by abdominal pain or nausea/vomiting Diverticulitis Classically causes left lower quadrant pain, diarrhoea and fever Antibiotic therapy More common with broad spectrum antibiotics Clostridium difficile is also seen with antibiotic use Constipation causing overflow A history of alternating diarrhoea and constipation may be given May lead to faecal incontinence in the elderly Chronic Diarrhoea Irritable bowel syndrome Extremely common. The most consistent features are abdominal pain, bloating and change in bowel habit. Patients may be divided into those with diarrhoea predominant IBS and those with constipation predominant IBS. Features such as lethargy, nausea, backache and bladder symptoms may also be present Ulcerative colitis Bloody diarrhoea may be seen. Crampy abdominal pain and weight loss are also common. Faecal urgency and tenesmus may occur Crohn's disease Crampy abdominal pains and diarrhoea. Bloody diarrhoea less common than in ulcerative colitis. Other features include malabsorption, mouth ulcers perianal disease and intestinal obstruction Colorectal cancer Symptoms depend on the site of the lesion but include diarrhoea, rectal bleeding, anaemia and constitutional symptoms e.g. Weight loss and anorexia Coeliac disease In children may present with failure to thrive, diarrhoea and abdominal distension In adults lethargy, anaemia, diarrhoea and weight loss are seen. Other autoimmune conditions may coexist Other conditions associated with diarrhoea include: Thyrotoxicosis Laxative abuse Appendicitis with pelvic abscess or pelvic appendix Radiation enteritis Diagnosis Stool culture Abdominal and digital rectal examination Consider colonoscopy (radiological studies unhelpful) Thyroid function tests, serum calcium, anti endomysial antibodies, glucose

Answer 1360

At 2 months of age, s aureus is most likely. In children aged 6 months to 4 years, Kigella is the most likely infecting organism. Discitis in children In children, infectious discitis (D) and infectious spondylodiscitis (SD) are rare diseases that can cause significant clinical problems, including spinal deformities and segmental instabilities. Moreover, when the infection spreads into the spinal channel, D and SD can cause devastating neurologic complications. Early diagnosis and treatment may reduce these risks. Several different bacterial pathogens can cause D and SD, and, in some cases, particularly those due to Staphylococcus aureus, Kingella kingae, Mycobacterium tuberculosis, Brucella spp., the appropriate choice of drug is critical to achieve cure. In most cases the infections spreads to the site haematogenously from a separate site. Less commonly, it arises as a result of direct inoculation. A triphasic age distribution is described; the first peak incidence is in children aged only a few weeks or months old, the second in those between 6 months and the end of the preschool period, and the third in school-aged children. Initial treatment is with broad spectrum intravenous antibiotics that cover s aureus, children aged 4 months to 6 years need cover for Kigella. More tailored therapy can be added later depending on progress and culture results.

Answer 1361

Calcitonin has the opposite effect of PTH and is released from the thyroid gland. Calcium homeostasis Calcium ions are linked to a wide range of physiological processes. The largest store of bodily calcium is contained within the skeleton. Calcium levels are primarily controlled by parathyroid hormone, vitamin D and calcitonin. Hormonal regulation of calcium Hormone Actions Parathyroid hormone (PTH) Increase calcium levels and decrease phosphate levels Increases bone resorption Immediate action on osteoblasts to increase ca2+ in extracellular fluid Osteoblasts produce a protein signaling molecule that activate osteoclasts which cause bone resorption Increases renal tubular reabsorption of calcium Increases synthesis of 1,25(OH)2D (active form of vitamin D) in the kidney which increases bowel absorption of Ca2+ Decreases renal phosphate reabsorption 1,25-dihydroxycholecalciferol (the active form of vitamin D) Increases plasma calcium and plasma phosphate Increases renal tubular reabsorption and gut absorption of calcium Increases osteoclastic activity at high levels and osteoblasts at low levels Increases renal phosphate reabsorption Calcitonin Secreted by C cells of thyroid Inhibits intestinal calcium absorption Inhibits osteoclast activity Inhibits renal tubular absorption of calcium Both growth hormone and thyroxine also play a small role in calcium metabolism.

Answer 1362

The phrenic nerve lies anteriorly at this point. The vagus passes anteriorly and then arches backwards immediately superior to the root of the left bronchus, giving off the recurrent laryngeal nerve as it does so. Lung anatomy The right lung is composed of 3 lobes divided by the oblique and transverse fissures. The left lung has two lobes divided by the oblique fissure.The apex of both lungs is approximately 4cm superior to the sterno-costal joint of the first rib. Immediately below this is a sulcus created by the subclavian artery. Peripheral contact points of the lung Base: diaphragm Costal surface: corresponds to the cavity of the chest Mediastinal surface: Contacts the mediastinal pleura. Has the cardiac impression. Above and behind this concavity is a triangular depression named the hilum, where the structures which form the root of the lung enter and leave the viscus. These structures are invested by pleura, which, below the hilum and behind the pericardial impression, forms the pulmonary ligament Right lung Above the hilum is the azygos vein; Superior to this is the groove for the superior vena cava and right innominate vein; behind this, and nearer the apex, is a furrow for the innominate artery. Behind the hilum and the attachment of the pulmonary ligament is a vertical groove for the oesophagus; In front and to the right of the lower part of the oesophageal groove is a deep concavity for the extrapericardiac portion of the inferior vena cava. The root of the right lung lies behind the superior vena cava and the right atrium, and below the azygos vein. The right main bronchus is shorter, wider and more vertical than the left main bronchus and therefore the route taken by most foreign bodies. Left lung Above the hilum is the furrow produced by the aortic arch, and then superiorly the groove accommodating the left subclavian artery; Behind the hilum and pulmonary ligament is a vertical groove produced by the descending aorta, and in front of this, near the base of the lung, is the lower part of the oesophagus. The root of the left lung passes under the aortic arch and in front of the descending aorta. Inferior borders of both lungs 6th rib in mid clavicular line 8th rib in mid axillary line 10th rib posteriorly The pleura runs two ribs lower than the corresponding lung level. Bronchopulmonary segments Segment number Right lung Left lung 1 Apical Apical 2 Posterior Posterior 3 Anterior Anterior 4 Lateral Superior lingular 5 Medial Inferior lingular 6 Superior (apical) Superior (apical) 7 Medial basal Medial basal 8 Anterior basal Anterior basal 9 Lateral basal Lateral basal 10 Posterior basal Posterior basal

Answer 1363

This lady's young age, coupled with ER negativity and extensive nodal disease with suspicion of metastatic disease makes her a candidate for treatment with trastuzumab (herceptin). Biological agents Agents Target Uses Adalimumab Infliximab Etanercept TNF alpha inhibitor Crohns disease Rheumatoid disease Bevacizumab Anti VEGF (anti angiogenic) Colorectal cancer Renal Glioblastoma Trastuzumab HER receptor Breast cancer Imatinib Tyrosine kinase inhibitor Gastrointestinal stromal tumours Chronic myeloid leukaemia Basiliximab IL2 binding site Renal transplants Cetuximab Epidermal growth factor inhibitor EGF positive colorectal cancers Detailed understanding of the actions of biological agents is well beyond the scope of the MRCS syllabus. However, many of these drugs are being frequently encountered in surgical patients.

Answer 1364

The next most appropriate management option when GTN or other topical nitrates has failed is to consider botulinum toxin injection. In males a lateral internal sphincterotomy would be an acceptable alternative. In a female who has yet to conceive this may predispose to delayed increased risk of sphincter dysfunction. Division of the external sphincter will result in faecal incontinence and is not a justified treatment for fissure. Rectal bleeding Rectal bleeding is a common cause for patients to be referred to the surgical clinic. In the clinical history it is useful to try and localise the anatomical source of the blood. Bright red blood is usually of rectal anal canal origin, whilst dark red blood is more suggestive of a proximally sited bleeding source. Blood which has entered the GI tract from a gastro-duodenal source will typically resemble malaena due to the effects of the digestive enzymes on the blood itself. In the table below we give some typical bleeding scenarios together with physical examination findings and causation. Cause Type of bleeding Features in history Examination findings Fissure in ano Bright red rectal bleeding Painful bleeding that occurs post defecation in small volumes. Usually antecedent features of constipation Muco-epithelial defect usually in the midline posteriorly (anterior fissures more likely to be due to underlying disease) Haemorroids Bright red rectal bleeding Post defecation bleeding noted both on toilet paper and drips into pan. May be alteration of bowel habit and history of straining. No blood mixed with stool. No local pain. Normal colon and rectum. Proctoscopy may show internal haemorrhoids. Internal haemorrhoids are usually impalpable. Crohns disease Bright red or mixed blood Bleeding that is accompanied by other symptoms such as altered bowel habit, malaise, history of fissures (especially anterior) and abscesses. Perineal inspection may show fissures or fistulae. Proctoscopy may demonstrate indurated mucosa and possibly strictures. Skip lesions may be noted at colonoscopy. Ulcerative colitis Bright red bleeding often mixed with stool Diarrhoea, weight loss, nocturnal incontinence, passage of mucous PR. Proctitis is the most marked finding. Peri anal disease is usually absent. Colonoscopy will show continuous mucosal lesion. Rectal cancer Bright red blood mixed volumes Alteration of bowel habit. Tenesmus may be present. Symptoms of metastatic disease. Usually obvious mucosal abnormality. Lesion may be fixed or mobile depending upon disease extent. Surrounding mucosa often normal, although polyps may be present. Investigation All patients presenting with rectal bleeding require digital rectal examination and procto-sigmoidoscopy as a minimal baseline. Remember that haemorrhoids are typically impalpable and to attribute bleeding to these in the absence of accurate internal inspection is unsatisfactory. In young patients with no other concerning features in the history a carefully performed sigmoidoscopy that demonstrates clear haemorrhoidal disease may be sufficient. If clear views cannot be obtained then patients require bowel preparation with an enema and a flexible sigmoidscopy performed. In those presenting with features of altered bowel habit or suspicion of inflammatory bowel disease a colonoscopy is the best test. Patients with excessive pain who are suspected of having a fissure may require an examination under general or local anaesthesia. In young patients with external stigmata of fissure and a compatible history it is acceptable to treat medically and defer internal examination until the fissure is healed. If the fissure fails to heal then internal examination becomes necessary along the lines suggested above to exclude internal disease. Special tests In patients with a malignancy of the rectum the staging investigations comprise an MRI of the rectum to identify circumferential resection margin compromise and to identify mesorectal nodal disease. In addition to this CT scanning of the chest abdomen and pelvis is necessary to stage for more distant disease. Some centres will still stage the mesorectum with endo rectal ultrasound but this is becoming far less common. Patients with fissure in ano who are being considered for surgical sphincterotomy and are females who have an obstetric history should probably have ano rectal manometry testing performed together with endo anal ultrasound. As this service is not universally available it is not mandatory but in the absence of such information there are continence issues that may arise following sphincterotomy. Management Disease Management Fissure in ano GTN ointment 0.2% or diltiazem cream applied topically is the usual first line treatment. Botulinum toxin for those who fail to respond. Internal sphincterotomy for those who fail with botox, can be considered earlier in males. Haemorroids Lifestyle advice, for small internal haemorrhoids can consider injection sclerotherapy or rubber band ligation. For external haemorrhoids consider haemorrhoidectomy. Modern options include HALO procedure and stapled haemorrhoidectomy. Inflammatory bowel disease Medical management- although surgery may be needed for fistulating Crohns (setons). Rectal cancer Anterior resection or abdomino-perineal excision of the colon and rectum. Total mesorectal excision is now standard of care. Most resections below the peritoneal reflection will require defunctioning ileostomy. Most patients will require preoperative radiotherapy.

Answer 1365

Fistula in ano in patients with Crohns disease should be managed with insertion of seton. In patients with IBD, management of fistula should be minimalistic and complex procedures best avoided. Laying open fistulas in this situation is likely to result in a chronic and non healing wound. Anal fistula Fistula in ano is the most common form of ano rectal sepsis. Fistulae will have both an internal opening and external opening, these will be connected by tract(s). Complexity arises because of the potential for multiple entry and exit sites, together with multiple tracts. Fistulae are classified into four main groups according to anatomical location and the degree of sphincter involvement. Simple uncomplicated fistulae are low and do not involve more than 30% of the external sphincter. Complex fistulae involve the sphincter, have multiple branches or are non cryptoglandular in origin[1] Assessment Examination of the perineum for signs of trauma, external openings or the stigmata of IBD is important. Digital rectal examination may reveal the cord linking the internal and external openings. At the same time the integrity of the sphincter mechanism can be assessed. Low, uncomplicated fistulas may not require any further assessment, other groups will usually require more detailed investigation. For the fistula, the use of endo-anal USS with instillation of hydrogen peroxide into the fistula tract may be helpful. Ano-rectal MRI scanning is also a useful tool, it is sensitive and specific for the identification of fistula anatomy, branching tracts and identifying occult sphincter involvement[2]. Identification of the internal opening Fistulas with an external opening less than 3cm from the anal verge will typically obey Goodsalls rule Therapies Seton suture A seton is a piece of material that is passed through the fistula between the internal and external openings that allows the drainage of sepsis. This is important as undrained septic foci may drain along the path of least resistance, which may result in the development of accessory tracts and openings. Their main use is in treating complex fistula. Two types of seton are recognised, simple and cutting. Simple setons lie within the fistula tract and encourage both drainage and fibrosis. A cutting seton is inserted and the skin incised. The suture is tightened and re-tightened at regular intervals. This may convert a high fistula to a low fistula. Since the tissue will scar surrounding the fistula it is hoped that this technique will minimise incontinence[3]. Unfortunately, a large retrospective review of the literature related to the use of cutting setons has found that they are associated with a 12% long term incontinence rate [4] Fistulotomy Low fistulas, that are simple should be treated by fistulotomy once the acute sepsis has been controlled. Fistulotomy (where safe) provides the highest healing rates [5]. Because fistulotomy is regarded as having a high cure rate, there are some who prefer to use this technique with more extensive sphincter involvement. In these patients the fistulotomy is performed as for a low fistula. However, the muscle that is encountered is then divided and reconstructed with an overlapping sphincter repair. A price is paid in terms of incontinence with this technique and up to 12.5% of patients who were continent pre-operatively will have issues relating to continence post procedure[6]. The same group also randomised between fistulotomy and sphincter reconstruction and ano-rectal advancement flaps for the treatment of complex cryptoglandular fistulas and reported similar outcomes in terms of recurrence (>90%) and disturbances to continence (20%)[7]. Other authors have found adverse outcomes following fistulotomy in patients who have undergone previous surgery, are of female gender or who have high internal openings [8], in these patients careful assessment of pre-operative sphincter function should be considered mandatory prior to fistulotomy. Anal fistula plugs and fibrin glue The desire to avoid injury to the sphincter complex has led to surgeons using both fibrin glue and plugs to try and improve fistula healing. Meticulous preparation of the tract and prior use of a draining seton is likely to improve chances of success. The use of anal fistula plugs in high transphincteric fistula of cryptoglandular origin is to be discouraged because of the high incidence of non response in patients treated with such devices [9]In most patients septic complications are the reasons for failure [10]. Fibrin glue is a popular option for the treatment of fistula. There is variability of reported healing rates In some cases initial success rates of up to 50% healing at six months are reported (in patients with complex cryptogenic fistula). Of these successes 25% suffer a long term recurrence of fistula [11]. There are, however, no obvious cases of damage to the sphincter complex and the use of the devices does not appear to adversely impact on subsequent surgical options. Ano-rectal advancement flaps This procedure is primarily directed at high fistulae, and is considered attractive as a sphincter saving operation. The procedure is performed either with the patient in the prone jack knife position or in lithotomy (depending upon the site of the fistula). The dissection is commenced in the sub mucosal plane (which may be infiltrated with dilute adrenaline solution to ease dissection). The dissection is continued into healthy proximal tissue. This is brought down and sutured over the defect. Follow up of patients with cryptoglandular fistulas treated with advancement flaps shows a success in up to 80% patients[12-14]. With most recurrences occurring in the first 6 months following surgery[12]. Continence was affected in some patients, with up to 10% describing major continence issues post operatively. Ligation of the intersphincteric tract procedure In this procedure an incision is made in the intersphincteric groove and the fistula tract dissected out in this plane and divided. A greater than 90% cure rate within 4 weeks was initially reported[15]. Others have subsequently performed similar studies on larger numbers of patients with similar success rates. Fistulotomy at the time of abscess drainage? A Cochrane review conducted in 2010 suggests that primary fistulotomy for low, uncomplicated fistula in ano may be safe and associated with better outcomes in relation to long term chronic sepsis[16]. However, there is a danger that such surgery performed by non specialists may result in a higher complication rate and therefore the traditional teaching is that primary treatment of acute sepsis is incision and drainage only. All agree that high/ complex fistulae should never be subject to primary fistulotomy in the acute setting. References 1. Parks, A.G., P.H. Gordon, and J.D. Hardcastle, A classification of fistula-in-ano. Br J Surg, 1976. 63(1): p. 1-12. 2. Lunniss, P.J., et al., Magnetic resonance imaging of fistula-in-ano. Dis Colon Rectum, 1994. 37(7): p. 708-18. 3. Misra, M.C. and B.M. Kapur, A new non-operative approach to fistula in ano. Br J Surg, 1988. 75(11): p. 1093-4. 4. Ritchie, R.D., J.M. Sackier, and J.P. Hodde, Incontinence rates after cutting seton treatment for anal fistula. Colorectal Dis, 2009. 11(6): p. 564-71. 5. Tyler, K.M., C.B. Aarons, and S.M. Sentovich, Successful sphincter-sparing surgery for all anal fistulas. Dis Colon Rectum, 2007. 50(10): p. 1535-9. 6. Perez, F., et al., Prospective clinical and manometric study of fistulotomy with primary sphincter reconstruction in the management of recurrent complex fistula-in-ano. Int J Colorectal Dis, 2006. 21(6): p. 522-6. 7. Perez, F., et al., Randomized clinical and manometric study of advancement flap versus fistulotomy with sphincter reconstruction in the management of complex fistula-in-ano. Am J Surg, 2006. 192(1): p. 34-40. 8. Garcia-Aguilar, J., et al., Anal fistula surgery. Factors associated with recurrence and incontinence. Dis Colon Rectum, 1996. 39(7): p. 723-9. 9. Ortiz, H., et al., Randomized clinical trial of anal fistula plug versus endorectal advancement flap for the treatment of high cryptoglandular fistula in ano. Br J Surg, 2009. 96(6): p. 608-12. 10. El-Gazzaz, G., M. Zutshi, and T. Hull, A retrospective review of chronic anal fistulae treated by anal fistulae plug. Colorectal Dis, 2010. 12(5): p. 442-7. 11. Haim, N., et al., Long-term results of fibrin glue treatment for cryptogenic perianal fistulas: a multicenter study. Dis Colon Rectum, 2011. 54(10): p. 1279-83. 12. Ortiz, H., et al., Length of follow-up after fistulotomy and fistulectomy associated with endorectal advancement flap repair for fistula in ano. Br J Surg, 2008. 95(4): p. 484-7. 13. Kodner, I.J., et al., Endorectal advancement flap repair of rectovaginal and other complicated anorectal fistulas. Surgery, 1993. 114(4): p. 682-9; discussion 689-90. 14. Abbas, M.A., R. Lemus-Rangel, and A. Hamadani, Long-term outcome of endorectal advancement flap for complex anorectal fistulae. Am Surg, 2008. 74(10): p. 921-4. 15. Rojanasakul, A., et al., Total anal sphincter saving technique for fistula-in-ano; the ligation of intersphincteric fistula tract. J Med Assoc Thai, 2007. 90(3): p. 581-6. 16. Malik, A.I., R.L. Nelson, and S. Tou, Incision and drainage of perianal abscess with or without treatment of anal fistula. Cochrane Database Syst Rev, 2010(7): p. CD006827.

Answer 1366

This is a Gritti - Stokes amputation. During a Gritti - Stokes operation the patella is conserved and swung posteriorly to cover the distal femoral surface. Amputations Amputations are indicated when the affected limb is one of the following: Dead non viable Deadly where it is posing a major threat to life Dead useless where it is viable but a prosthesis would be preferable Orthopaedic surgery Amputation is often undertaken as an option of last resort e.g. Limb salvage has failed and the limb is so non functional that mobility needs would be best met with prosthesis. Chronic fracture non union or significant limb shortening following trauma would fit into this category. Occasionally following major trauma a primary amputation is preferable. This would be the case in an open fracture with major distal neurovascular compromise and other more life threatening injuries are present. Vascular surgery The first two categories are the most prevalent. Diabetic foot sepsis is often a major cause of sepsis which can spread rapidly in the presence of established peripheral vascular disease. As a general rule the main issue in vascular surgery is to optimise vascular inflow prior to surgery. The more distal the planned amputation is to be, the more important this rule becomes. In other situations there has been something such as an embolic event that has not been revascularised in time. In this case the limb shows fixed mottling and an amputation will be needed. Types of amputations As the vast majority of commonly performed amputations affect the lower limbs these will be covered here. The main categories of amputations are: Pelvic disarticulation (hindquarter) Above knee amputation Gritti Stokes (through knee amputation) Below knee amputation (using either Skew or Burgess flaps) Syme's amputation (through ankle) Amputations of mid foot and digits Choosing a level of amputation depends on: The disease process being treated Desired functional outcome Co-morbidities of the patient Above knee amputations Quick to perform Heal reliably Patients regain their general health quickly For this benefit, a functional price has to be paid and many patients over the age of 70 will never walk on an above knee prosthesis. Above knee amputations use equal anterior-posterior flaps Below knee amputations Technically more challenging to perform Heal less reliably than their above knee counterparts. However, many more patients are able to walk using a below knee prosthesis. In below knee amputations the two main flaps are Skew flaps or the Burgess long posterior flap. Skew flaps result in a less bulky limb that is easier to attach a prosthesis to. It is worth remembering that whilst it may be technically feasible to offer a below knee amputation there may be circumstances where an above knee option is preferable. For example, in fixed flexion deformities of the lower limb, little functional benefit would be gained from below knee amputation surgery.

Answer 1367

Intramedullary devices are normally recommended for reverse oblique, transverse subtrochanteric fractures. Hip fractures Background Neck of femur (NOF) fracture is a common orthopaedic presentation, with over 65000 fractures in the UK per year. Like many orthopaedic injuries, there is a bimodal age distribution. It is imperative to distinguish between the high energy injury in a young patient, and the low energy osteoporotic fracture in the elderly, as their management aims are very different: Young patient - Usually high energy trauma (e.g road traffic accident, horse riding) and needs treating in accordance with Advanced Trauma Life Support (ATLS) principles. Will often have associated injuries. Aim is to retain the patients own anatomy, and optimise their function. Elderly patient - Predominantly female, fall from standing height (fragility fracture). Often patients have multiple comorbidities that will ultimately dictate their prognosis. Aim of orthopaedic treatment is to immediately regain patient mobility so that morbidity (infection, thromboembolic events, pressure sores etc) and mortality associated with prolonged bed rest is avoided. Left untreated, a neck of femur fracture can be considered a terminal event. Historically, mortality associated with elderly hip fracture is 10% at one month, and 30% at one year. However, this has been improved in the UK with the introduction of multidisciplinary, orthogeriatric lead care and the National Hip Fracture Database and Best Practice Tariff. Pertinent anatomy Osteology - normal neck-shaft angle is 130 +/- 7 degrees, and 10 +/- 7 degrees of neck anteversion. Vascular supply - The predominant blood supply to the femoral head and neck is from the medial and lateral femoral circumflex arteries (branches of profunda femoris). These anastomose and pierce the joint capsule at the base of the neck, mainly posteriorly. There is a small vascular contribution from the artery of the ligament teres. Understanding the blood supply is fundamental to the decision making process in treating NOF fractures. Presentation and initial management Typically, patients present with pain in the hip/groin, a shortened, abducted, externally rotated leg (due to the unopposed pull of the muscles that act across the hip joint) and the inability to straight-leg-raise. With undisplaced fractures, signs are more subtle. High energy injuries should be treated in line with ATLS principles. All patients should be fluid resuscitated, have adequate pain relief (often with a fascio-iliiaca nerve block), and be optimised for surgery. In addition, elderly patients should be assessed by an orthogeriatrician. Imaging Anteroposterior and cross-table lateral plain radiographs are sufficient to diagnose the majority of NOF fractures. If the fracture extends below the level of the lesser trochanter, or there is any possibility of pathological fracture, full length femur views are essential to plan surgery. Where there is a high index of suspicion of fracture, but plain radiographs are inconclusive, gold standard investigation is MRI. However, if unavailable within 24 hours, or if the patient will not tolerate MRI, CT is appropriate. The majority of fractures can be seen with modern CT techniques, and so this is becoming first line in many hospitals. Classification There has been a move away from named classification systems towards descriptive classification systems. Two main types of NOF exist: Intra-capsular, and extra-capsular. Extra-capsular fractures are further divided into pertrochanteric or subtrochanteric (within 5cm distal to the lesser trochanter). All fractures are then described as undisplaced, minimally displaced, or displaced. Femoral neck and head blood supply disruption is common with intracapsular NOF fractures, and rare with extracapsular fractures. This fundamental principle underpins the practise of arthroplasty for intracapsular fractures, and fixation for extracapsular fractures. If you wish to use a named classification system, the most commonly used are below: Elderly intracapsular - Garden Classification Young intrasapsular - Pauvels Classification Intertrochanteric - Evans Subtrochanteric - Russell Taylor Treatment In general, NOF fractures are treated operatively except if the patient is deemed unlikely to survive an anaesthetic. Best Practice Tarif (BPT) dictates that surgery should happen within 36 hours, as delay of greater than 48 hours is associated with increased morbidity and mortality. Below are suggested algorithms for the treatment of NOF. There are some areas of debate/controversy which are detailed below. * The priority with the young patient is to retain the femoral head if possible, even with a displaced intracapsular fracture. The risk of avascular necrosis and non-union (and therefore revision surgery) associated with internal fixation needs weighing up against the sequelae of total hip replacement in the young (wear, dislocation, revision). Discussion is necessary with the patient, on a case by case basis. ** Undisplaced fractures in the elderly can be treated with internal fixation, often with cannulated screws. This is appropriate for valgus impacted subcapital fractures which are inherently stable, to prevent secondary displacement. This does still carry the risk of AVN or non-union, and therefore a future revision. For this reason, many surgeons advocate arthroplasty as a single surgery. *** NICE guidance - patients who fulfil these criteria should be offered total hip replacement which conveys better function and prosthetic survivorship, compared with hemiarthroplasty, but at an increased risk of dislocation. * Intertrochanteric fractures vary greatly in their stability. If the trochanter (and therefore lateral wall), and medial calcar is in tact, then the fracture configuration bears stability. This can be treated with a DHS, as collapse of the fracture is predictable. Where either or both structures are involved in the fracture, stability becomes compromised and many surgeons will favour using an intramedullary device. This is an ongoing debate, and difficult to test in an exam setting. Post operative management Patients should be mobilised fully weight bearing where possible. Care is multidisciplinary in its delivery. Elderly patients should have orthogeriatrician assessment of comorbidity, and bone health with secondary prevention measures if appropriate. There should be early involvement of physiotherapy and occupational therapy services. For further guidance see sources listed below. NICE clinical guidance on hip fracture: https://www.nice.org.uk/guidance/cg124 Best Practice Tarif: www.nhfd.co.uk/20/hipfractureR.../Best%20Practice%20Tariff%20User%20Guide.pdf National Hip Fracture Database: www.nhfd.co.uk/

Answer 1368

Ankle reflex The ankle reflex is elicited by tapping the Achilles tendon with a tendon hammer. It tests the S1 and S2 nerve roots. It is typically delayed in L5 and S1 disk prolapses.

Answer 1369

Erythrocytes lack a mitochondria and therefore they generate energy via glycolytic pathways only. All the other cell types have mitochondria and will therefore use the Krebs cycle unless true anaerobic conditions prevail. Cellular metabolism - Circulating glucose enters the cell, subsequently a glycolytic process results in the generation of ATP and pyruvate In the presence of oxygen, the pyruvate from the glycolytic process then enters the Krebs cycle When oxygen is limited or absent, pyruvate enters an anaerobic pathway. In these reactions, pyruvate can be converted into lactic acid. In addition to generating an additional ATP, this pathway serves to keep the pyruvate concentration low so glycolysis continues, and it oxidizes NADH into the NAD+ needed by glycolysis. In this reaction, lactic acid replaces oxygen as the final electron acceptor. Anaerobic respiration occurs in most cells of the body when oxygen is limited or mitochondria are absent or nonfunctional. For example, because erythrocytes (red blood cells) lack mitochondria, they must produce their ATP from anaerobic respiration. This is an effective pathway of ATP production for short periods of time, ranging from seconds to a few minutes. The lactic acid produced diffuses into the plasma and is carried to the liver, where it is converted back into pyruvate or glucose via the Cori cycle In the presence of oxygen, pyruvate can enter the Krebs cycle where additional energy is extracted as electrons are transferred from the pyruvate to the receptors NAD+, GDP, and FAD, with carbon dioxide being a by product. The NADH and FADH2 pass electrons on to the electron transport chain, which uses the transferred energy to produce ATP. As the terminal step in the electron transport chain, oxygen is the terminal electron acceptor and creates water inside the mitochondria. The oxidative pathways eventually yield a total of 36 ATP molecules and are therefore far better at generating energy than anaerobic pathways.

Answer 1370

Airway injuries can develop marked laryngeal swelling and early intubation is essential to protect the airway. Burns Burns may be thermal, chemical or electrical. In the former category are burns which occur as a result of heat. Chemical burns occur when the skin is exposed to an extremely caustic or alkaline substance. Electrical burns occur following exposure to electrical current. The immediate management includes removal of the burning source which usually includes irrigation of the burned area. A detailed assessment then needs to be made of the extent of the burns and a number of charts are available for recording this information. The degree of injury relates to the temperature and duration of exposure. Most domestic burns are mainly scalds in young children. Following the burn, there is a local response with progressive tissue loss and release of inflammatory cytokines. Systemically, there are cardiovascular effects resulting from fluid loss and sequestration of fluid into the third space. There is a marked catabolic response. Immunosuppression is common with large burns and bacterial translocation from the gut lumen is a recognised event. Sepsis is a common cause of death following major burns. Types of burn Type of burn Skin layers affected Skin appearance Blanching Management Epidermal/Superficial Epidermis Red, moist Yes Superficial partial thickness Epidermis and part of papillary dermis affected Pale, dry Yes Normally heals with no intervention Deep partial thickness Epidermis, whole papillary dermis affected Mottled red colour No Needs surgical intervention (depending on site) Full thickness Whole skin layer and subcutaneous tissue affected Dry, leathery hard wound No Burns centre Depth of burn assessment Bleeding on needle prick Sensation Appearance Blanching to pressure Percentage burn estimation Lund Browder chart: most accurate even in children Wallace rule of nines Palmar surface: surface area palm = 0.8% burn >15% body surface area burns in adults needs urgent burn fluid resuscitation Transfer to burn centre if: Need burn shock resuscitation Face/hands/genitals affected Deep partial thickness or full thickness burns Significant electrical/chemical burns Management The initial aim is to stop the burning process and resuscitate the patient. Intravenous fluids will be required for children with burns greater than 10% of total body surface area. Adults with burns greater than 15% of total body surface area will also require IV fluids. The fluids are calculated using the Parkland formula which is; volume of fluid= total body surface area of the burn % x weight (Kg) x2-4 (preference for lower amount i.e. 2ml to avoid excessive fluid overload). Half of the fluid is administered in the first 8 hours. A urinary catheter should be inserted. Analgesia should be given. Complex burns, burns involving the hand perineum and face and burns >10% in adults and >5% in children should be transferred to a burns unit. Circumferential burns affecting a limb or severe torso burns impeding respiration may require escharotomy to divide the burnt tissue. Conservative management is appropriate for superficial burns and mixed superficial burns that will heal in 2 weeks. More complex burns may require excision and skin grafting. Excision and primary closure is not generally practised as there is a high risk of infection. There is no evidence to support the use of anti microbial prophylaxis or topical antibiotics in burn patients. Escharotomies Indicated in circumferential full thickness burns to the torso or limbs. Careful division of the encasing band of burn tissue will potentially improve ventilation (if the burn involves the torso), or relieve compartment syndrome and oedema (where a limb is involved) References www.euroburn.org/e107files/downloads/guidelinesburncare.pdf Barajas-Nava LA, LÃ³pez-Alcalde J, RoquÃ© i Figuls M, SolÃ I, Bonfill Cosp X. Antibiotic prophylaxis for preventing burn wound infection. Cochrane Database of Systematic Reviews 2013, Issue 6. Art. No.: CD008738. DOI: 10.1002/14651858.CD008738.pub2. Hettiaratchy S & Papini R. Initial management of a major burn: assessment and resuscitation. BMJ 2004;329:101-103

Answer 1371

He is most likely to have Peutz-Jeghers syndrome which is associated with Hamartomas. Peutz-Jeghers syndrome Peutz-Jeghers syndrome is an autosomal dominant condition characterised by numerous benign hamartomatous polyps in the gastrointestinal tract. It is also associated with pigmented freckles on the lips, face, palms and soles. Around 50% of patients will have died from a gastrointestinal tract cancer by the age of 60 years. Genetics Autosomal dominant Responsible gene encodes serine threonine kinase LKB1 or STK11 Features Hamartomatous polyps in GI tract (mainly small bowel) Pigmented lesions on lips, oral mucosa, face, palms and soles Intestinal obstruction e.g. intussusception (which may lead to diagnosis) Gastrointestinal bleeding Management Conservative unless complications develop

Answer 1372

As this man is relatively young and has full thickness prolapse a rectopexy is the most appropriate procedure. It will give the lowest recurrence rates. This could be a sutured rectopexy or ventral mesh rectopexy. If the latter procedure is adopted, it is important to counsel the patient around the risks of sexual dysfunction (close to prostate). Rectal prolapse Rectal prolapse may be divided into internal and external prolapse. Patients with the former condition may have internal intussceception of the rectum and present with constipation, obstructed defecation and occasionally faecal incontinence. Patients with external rectal prolapse have a full thickness external protrusion of the rectum. Risk factors for the condition include multiparity, pelvic floor trauma and connective tissue disorders. Diagnosis External prolapse is usually evident. Internal prolapse may be identified by defecating proctography and examination under anaesthesia. Sinister pathology should be excluded with endoscopy Treatment Perineal approaches include the Delormes operation, this avoids resection and is relatively safe but is associated with high recurrence rates. An Altmeirs operation involves a perineal excision of the sigmoid colon and rectum, it may be a more effective procedure than a Delormes but carries the risk of anastomotic leak. Rectopexy - this is an abdominal procedure. The rectum is mobilised and fixed onto the sacral promontary. A prosthetic mesh may be inserted. The recurrence rates are low and the procedure is well tolerated (particularly if performed laparoscopically). Risks with ventral mesh rectopexy include chronic pain and visceral mesh erosions. Thirsch tape- this is a largely historical procedure and involves encircling the rectum with tape or wire. It may be of use in a palliative setting.

Answer 1373

This patient does not need surgery! Subacute thyroiditis is suggested by the tender goitre, hyperthyroidism and raised ESR. The globally reduced uptake on technetium thyroid scan is also typical. This should resolve without any active intervention. Thyroiditis Sub acute thyroiditis Subacute thyroiditis (also known as De Quervain's thyroiditis) is thought to occur following viral infection and typically presents with hyperthyroidism Features Hyperthyroidism Painful goitre Raised ESR Globally reduced uptake on iodine-131 scan Management Usually self-limiting - most patients do not require treatment Thyroid pain may respond to aspirin or other NSAIDs In more severe cases steroids are used, particularly if hypothyroidism develops Hashimotos thyroiditis Hashimotos thyroiditis is an immunological disorder in which lymphocytes become sensitised to thyroidal antigens. The three most important antibodies include; thyroglobulin, TPO and TSH-R. During the early phase of Hashimotos the the thyroglobulin antibody is markedly elevated and then declines. Features Goitre and either euthyroid or mild hypothyroidism Progressive hypothyroidism (and associated symptoms) Management During the hyperthyroid phase of illness beta blockers may manage symptoms As hypothyroidism develops patients may require thyroxine

Answer 1374

Athletic boys and girls may develop this condition in their teenage years. It is caused by multiple micro fractures at the point of insertion of the tendon into the tibial tuberosity. Most cases settle with physiotherapy and rest. Knee injury Types of injury Ruptured anterior cruciate ligament Sport injury Mechanism: high twisting force applied to a bent knee Typically presents with: loud crack, pain and RAPID joint swelling (haemoarthrosis) Poor healing Management: intense physiotherapy or surgery Ruptured posterior cruciate ligament Mechanism: hyperextension injuries Tibia lies back on the femur Paradoxical anterior draw test Rupture of medial collateral ligament Mechanism: leg forced into valgus via force outside the leg Knee unstable when put into valgus position Menisceal tear Rotational sporting injuries Delayed knee swelling Joint locking (Patient may develop skills to 'unlock' the knee Recurrent episodes of pain and effusions are common, often following minor trauma Chondromalacia patellae Teenage girls, following an injury to knee e.g. Dislocation patella Typical history of pain on going downstairs or at rest Tenderness, quadriceps wasting Dislocation of the patella Most commonly occurs as a traumatic primary event, either through direct trauma or through severe contraction of quadriceps with knee stretched in valgus and external rotation Genu valgum, tibial torsion and high riding patella are risk factors Skyline x-ray views of patella are required, although displaced patella may be clinically obvious An osteochondral fracture is present in 5% The condition has a 20% recurrence rate Fractured patella 2 types: i. Direct blow to patella causing undisplaced fragments ii. Avulsion fracture Tibial plateau fracture Occur in the elderly (or following significant trauma in young) Mechanism: knee forced into valgus or varus, but the knee fractures before the ligaments rupture Varus injury affects medial plateau and if valgus injury, lateral plateau depressed fracture occurs Classified using the Schatzker system (see below) Schatzker Classification system for tibial plateau fractures Type Anatomical description Features 1 Vertical split of lateral condyle Fracture through dense bone, usually in the young. It may be virtually undisplaced, or the condylar fragment may be pushed inferiorly and tilted 2 Vertical split of the lateral condyle combined with an adjacent load bearing part of the condyle The wedge fragment (which may be of variable size), is displaced laterally; the joint is widened. Untreated, a valgus deformity may develop 3 Depression of the articular surface with intact condylar rim The split does not extend to the edge of the plateau. Depressed fragments may be firmly embedded in subchondral bone, the joint is stable 4 Fragment of the medial tibial condyle Two injuries are seen in this category; (1) a depressed fracture of osteoporotic bone in the elderly. (2) a high energy fracture resulting in a condylar split that runs from the intercondylar eminence to the medial cortex. Associated ligamentous injury may be severe 5 Fracture of both condyles Both condyles fractured but the column of the metaphysis remains in continuity with the tibial shaft 6 Combined condylar and subcondylar fractures High energy fracture with marked comminution

Answer 1375

C-Laceration of the middle meningeal artery This will account for the scenario given where there is a brief delay prior to death. The other options are less acute and a supratentorial herniation would not occur in this setting. Head injury Patients who suffer head injuries should be managed according to ATLS principles and extra cranial injuries should be managed alongside cranial trauma. Inadequate cardiac output will compromise CNS perfusion irrespective of the nature of the cranial injury. Types of traumatic brain injury Extradural haematoma Bleeding into the space between the dura mater and the skull. Often results from acceleration-deceleration trauma or a blow to the side of the head. The majority of extradural haematomas occur in the temporal region where skull fractures cause a rupture of the middle meningeal artery. Features Raised intracranial pressure Some patients may exhibit a lucid interval Subdural haematoma Bleeding into the outermost meningeal layer. Most commonly occur around the frontal and parietal lobes. May be either acute or chronic. Risk factors include old age and alcoholism. Slower onset of symptoms than a extradural haematoma. Subarachnoid haemorrhage Usually occurs spontaneously in the context of a ruptured cerebral aneurysm, but may be seen in association with other injuries when a patient has sustained a traumatic brain injury. Pathophysiology Primary brain injury may be focal (contusion/ haematoma) or diffuse (diffuse axonal injury) Diffuse axonal injury occurs as a result of mechanical shearing following deceleration, causing disruption and tearing of axons Intra-cranial haematomas can be extradural, subdural or intracerebral, while contusions may occur adjacent to (coup) or contralateral (contre-coup) to the side of impact Secondary brain injury occurs when cerebral oedema, ischaemia, infection, tonsillar or tentorial herniation exacerbates the original injury. The normal cerebral auto regulatory processes are disrupted following trauma rendering the brain more susceptible to blood flow changes and hypoxia The Cushings reflex (hypertension and bradycardia) often occurs late and is usually a pre terminal event Management Where there is life threatening rising ICP such as in extra dural haematoma and whilst theatre is prepared or transfer arranged use of IV mannitol/ frusemide may be required. Diffuse cerebral oedema may require decompressive craniotomy Exploratory Burr Holes have little management in modern practice except where scanning may be unavailable and to thus facilitate creation of formal craniotomy flap Depressed skull fractures that are open require formal surgical reduction and debridement, closed injuries may be managed non operatively if there is minimal displacement. ICP monitoring is appropriate in those who have GCS 3-8 and normal CT scan. ICP monitoring is mandatory in those who have GCS 3-8 and abnormal CT scan. Hyponatraemia is most likely to be due to syndrome of inappropriate ADH secretion. Minimum of cerebral perfusion pressure of 70mmHg in adults. Minimum cerebral perfusion pressure of between 40 and 70 mmHg in children. Interpretation of pupillary findings in head injuries Pupil size Light response Interpretation Unilaterally dilated Sluggish or fixed 3rd nerve compression secondary to tentorial herniation Bilaterally dilated Sluggish or fixed Poor CNS perfusion Bilateral 3rd nerve palsy Unilaterally dilated or equal Cross reactive (Marcus - Gunn) Optic nerve injury Bilaterally constricted May be difficult to assess Opiates Pontine lesions Metabolic encephalopathy Unilaterally constricted Preserved Sympathetic pathway disruption

Answer 1376

Both Lanz and Gridiron incisions can be used to perform an open appendicectomy. However, a Lanz incision provides for a superior cosmetic scar and is more easily extended than a Gridiron incision. Abdominal incisions Midline incision Commonest approach to the abdomen Structures divided: linea alba, transversalis fascia, extraperitoneal fat, peritoneum (avoid falciform ligament above the umbilicus) Bladder can be accessed via an extraperitoneal approach through the space of Retzius Paramedian incision Parallel to the midline (about 3-4cm) Structures divided/retracted: anterior rectus sheath, rectus (retracted), posterior rectus sheath, transversalis fascia, extraperitoneal fat, peritoneum Incision is closed in layers Battle Similar location to paramedian but rectus displaced medially (and thus denervated) Now seldom used Kocher's Incision under right subcostal margin e.g. Cholecystectomy (open) Lanz Incision in right iliac fossa e.g. Appendicectomy Gridiron Oblique incision centered over McBurneys point- usually appendicectomy (less cosmetically acceptable than Lanz Gable Rooftop incision Pfannenstiel's Transverse supra pubic, primarily used to access pelvic organs McEvedy's Groin incision e.g. Emergency repair strangulated femoral hernia Rutherford Morrison Extraperitoneal approach to left or right lower quadrants. Gives excellent access to iliac vessels and is the approach of choice for first time renal transplantation.

Answer 1377

A-This patient is at high risk of refeeding syndrome. Nutrition - Refeeding syndrome Refeeding syndrome describes the metabolic abnormalities which occur on feeding a person following a period of starvation. The metabolic consequences include: Hypophosphataemia Hypokalaemia Hypomagnesaemia Abnormal fluid balance These abnormalities can lead to organ failure. Re-feeding problems If patient not eaten for > 5 days, aim to re-feed at < 50% energy and protein levels High risk for re-feeding problems If one or more of the following: BMI < 16 kg/m2 Unintentional weight loss >15% over 3-6 months Little nutritional intake > 10 days Hypokalaemia, Hypophosphataemia or hypomagnesaemia prior to feeding (unless high) If two or more of the following: BMI < 18.5 kg/m2 Unintentional weight loss > 10% over 3-6 months Little nutritional intake > 5 days History of: alcohol abuse, drug therapy including insulin, chemotherapy, diuretics and antacids Prescription Start at up to 10 kcal/kg/day increasing to full needs over 4-7 days Start immediately before and during feeding: oral thiamine 200-300mg/day, vitamin B co strong 1 tds and supplements Give K+ (2-4 mmol/kg/day), phosphate (0.3-0.6 mmol/kg/day), magnesium (0.2-0.4 mmol/kg/day)

Answer 1378

Phosphaturia causes cloudy urine. Haematuria Causes of haematuria Trauma Injury to renal tract Renal trauma commonly due to blunt injury (others penetrating injuries) Ureter trauma rare: iatrogenic Bladder trauma: due to RTA or pelvic fractures Infection Remember TB Malignancy Renal cell carcinoma (remember paraneoplastic syndromes): painful or painless Urothelial malignancies: 90% are transitional cell carcinoma, can occur anywhere along the urinary tract. Painless haematuria. Squamous cell carcinoma and adenocarcinoma: rare bladder tumours Prostate cancer Penile cancers: SCC Renal disease Glomerulonephritis Stones Microscopic haematuria common Structural abnormalities Benign prostatic hyperplasia (BPH) causes haematuria due to hypervascularity of the prostate gland Cystic renal lesions e.g. polycystic kidney disease Vascular malformations Renal vein thrombosis due to renal cell carcinoma Coagulopathy Causes bleeding of underlying lesions Drugs Cause tubular necrosis or interstitial nephritis: aminoglycosides, chemotherapy Interstitial nephritis: penicillin, sulphonamides, and NSAIDs Anticoagulants Benign Exercise Gynaecological Endometriosis: flank pain, dysuria, and haematuria that is cyclical Iatrogenic Catheterisation Radiotherapy; cystitis, severe haemorrhage, bladder necrosis Pseudohaematuria For example following consumption of beetroot References Http://bestpractice.bmj.com/best-practice/monograph/316/overview/aetiology.html

Answer 1379

In a child of this age, with the symptoms described a nephroblastoma is the most likely diagnosis. A perinephric abscess is most unlikely. If an abscess were to occur it would be confined to Gerotas fascia in the first instance, and hence anterior extension would be unlikely. Nephroblastoma Nephroblastoma (Wilms tumours) Usually present in first 4 years of life May often present as a mass associated with haematuria (pyrexia may occur in 50%) Often metastasise early (usually to lung) Treated by nephrectomy Younger children have better prognosis (<1 year of age =80% overall 5 year survival)

Answer 1380

Mnemonic for the nerves passing through the supraorbital fissure: Live Frankly To See Absolutely No Insult Lacrimal Frontal Trochlear Superior Division of Oculomotor Abducens Nasociliary Inferior Division of Oculomotor nerve The opthalmic artery arises from the internal carotid immediately after it has pierced the dura and arachnoid. It runs through the optic canal below the optic nerve and within its dural and arachnoid sheaths. It terminates as the supratrochlear and dorsal nasal arteries. Foramina of the base of the skull Foramen Location Contents Foramen ovale Sphenoid bone Otic ganglion V3 (Mandibular nerve:3rd branch of trigeminal) Accessory meningeal artery Lesser petrosal nerve Emissary veins Foramen spinosum Sphenoid bone Middle meningeal artery Meningeal branch of the Mandibular nerve Foramen rotundum Sphenoid bone Maxillary nerve (V2) Foramen lacerum/ carotid canal Located between the sphenoid, the apex of the petrous temporal and the basilar part of the occipital Base of the medial pterygoid plate. Internal carotid artery* Nerve and artery of the pterygoid canal Jugular foramen Temporal bone Anterior: inferior petrosal sinus Intermediate: glossopharyngeal, vagus, and accessory nerves. Posterior: sigmoid sinus (becoming the internal jugular vein) and some meningeal branches from the occipital and ascending pharyngeal arteries. Foramen magnum Occipital bone Anterior and posterior spinal arteries Vertebral arteries Medulla oblongata Stylomastoid foramen Temporal bone Stylomastoid artery Facial nerve Superior orbital fissure Sphenoid bone Oculomotor nerve (III) Recurrent meningeal artery Trochlear nerve (IV) Lacrimal, frontal and nasociliary branches of opthalmic nerve (V1) Abducent nerve (VI) Superior ophthalmic vein *= In life the foramen lacerum is occluded by a cartilagenous plug. The ICA initially passes into the carotid canal which ascends superomedially to enter the cranial cavity through the foramen lacerum.

Answer 1381

Imatinib is licensed for treatment of GIST in the United Kingdom for this situation. The guidance from the National Institute of Clinical evidence is that patients be reviewed at 12 weeks after initiating therapy. Biological agents Agents Target Uses Adalimumab Infliximab Etanercept TNF alpha inhibitor Crohns disease Rheumatoid disease Bevacizumab Anti VEGF (anti angiogenic) Colorectal cancer Renal Glioblastoma Trastuzumab HER receptor Breast cancer Imatinib Tyrosine kinase inhibitor Gastrointestinal stromal tumours Chronic myeloid leukaemia Basiliximab IL2 binding site Renal transplants Cetuximab Epidermal growth factor inhibitor EGF positive colorectal cancers Detailed understanding of the actions of biological agents is well beyond the scope of the MRCS syllabus. However, many of these drugs are being frequently encountered in surgical patients.

Answer 1382

The lingual nerve is closely related to the third molar and up to 10% of patients undergoing surgical extraction of these teeth may subsequently develop a lingual neuropraxia. The result is anaesthesia of the ipsilateral anterior aspect of the tongue. The inferior alveolar nerve innervates the teeth themselves. Lingual nerve - Sensory nerve to the mucosa of the presulcal part of the tongue, floor of mouth and mandibular lingual gingivae Arises from posterior trunk of the mandibular nerve (branch of trigeminal) Course runs past tensor veli palatini and lateral pterygoid (where it is joined by the chorda tympani branch of the facial nerve). Emerging from the cover of the lateral pterygoid it proceeds antero inferiorly lying on the surface of the medial pterygoid and lies close to the medial aspect of the mandibular ramus. At the junction of the vertical and horizontal rami of the mandible it is anterior to the inferior alveolar nerve. It then passes below the mandibular attachment of the superior pharyngeal constrictor. Eventually, it lies on the periosteum of the root of the third molar tooth. It then passes medial to the mandibular origin of mylohyoid and then passes forwards on the inferior surface of this muscle

Answer 1383

Intestinal malrotation with volvulus is treated with a Ladd's procedure Bilious vomiting in neonates Causes of intestinal obstruction with bilious vomiting in neonates Disorder Incidence and causation Age at presentation Diagnosis Treatment Duodenal atresia 1 in 5000 (higher in Downs syndrome) Few hours after birth AXR shows 'double bubble sign, contrast study may confirm Duodenoduodenostomy Malrotation with volvulus Usually cause by incomplete rotation during embryogenesis Usually 3-7 days after birth, volvulus with compromised circulation may result in peritoneal signs and haemodynamic instability Upper GI contrast study may show DJ flexure is more medially placed, USS may show abnormal orientation of SMA and SMV Ladd's procedure Jejunal/ ileal atresia Usually caused by vascular insufficiency in utero, usually 1 in 3000 Usually within 24 hours of birth AXR will show air-fluid levels Laparotomy with primary resection and anastomosis Meconium ileus Occurs in between 15 and20% of those babies with cystic fibrosis, otherwise 1 in 5000 Typically in first 24-48 hours of life with abdominal distension and bilious vomiting Air - fluid levels on AXR, sweat test to confirm cystic fibrosis Surgical decompression, serosal damage may require segmental resection Necrotising enterocolitis Up to 2.4 per 1000 births, risks increased in prematurity and inter-current illness Usually second week of life Dilated bowel loops on AXR, pneumatosis and portal venous air Conservative and supportive for non perforated cases, laparotomy and resection in cases of perforation of ongoing clinical deterioration

Answer 1384

The anterior interosseous nerve is a branch of the median nerve and is responsible for innervation of the lateral aspect of the flexor digitorum profundus. Forearm flexor muscles Muscle Origin Insertion Nerve supply Action Flexor carpi radialis Common flexor origin and surrounding fascia Front of bases of second and third metacarpals Median Flexes and abducts the carpus, part flexes the elbow and part pronates forearm Palmaris longus Common flexor origin Apex of palmar aponeurosis Median Wrist flexor Flexor carpi ulnaris Small humeral head arises from the common flexor origin and adjacent fascia. Ulnar head comes from medial border of olecranon and posterior border of ulna Pisiform and base of the fifth metacarpal Ulnar nerve Flexes and adducts the carpus Flexor digitorum superficialis Long linear origin from common flexor tendon, adjacent fascia and septa and medial border of the coronoid process Via tendons in the fibrous flexor sheath. At the level of the metacarpophalangeal joint each tendon split into two, these bands pass distally to their insertions Median Flexor of metacarpophalangeal joint and proximal interphalangeal joint Flexor digitorum profundus Upper two thirds of the medial and anterior surface of the ulna, medial side of the olecranon, medial half of the interosseous membrane Via tendons that lie deep to those of flexor digitorum superficialis to insert into the distal phalanx Medial part= ulnar, lateral part=anterior interosseous nerve Flexes the distal interphalangeal joints and the wrist

Answer 1385

This can be a challenging question. A particularly careless surgeon could encounter all of these. However, during a routine level 1 axillary exploration which is where the majority of sentinel nodes will be located, the nerves most commonly encountered are the intercostobrachial nerves. Axilla Boundaries of the axilla Medially Chest wall and Serratus anterior Laterally Humeral head Floor Subscapularis Anterior aspect Lateral border of Pectoralis major Fascia Clavipectoral fascia Content: Long thoracic nerve (of Bell) Derived from C5-C7 and passes behind the brachial plexus to enter the axilla. It lies on the medial chest wall and supplies serratus anterior. Its location puts it at risk during axillary surgery and damage will lead to winging of the scapula. Thoracodorsal nerve and thoracodorsal trunk Innervate and vascularise latissimus dorsi. Axillary vein Lies at the apex of the axilla, it is the continuation of the basilic vein. Becomes the subclavian vein at the outer border of the first rib. Intercostobrachial nerves Traverse the axillary lymph nodes and are often divided during axillary surgery. They provide cutaneous sensation to the axillary skin. Lymph nodes The axilla is the main site of lymphatic drainage for the breast.

Answer 1386

In an IVDU with back pain and pyrexia have a high suspicion for osteomylelitis. The most likely organism is staph aureus and the cervical spine is the most common region affected. TB tends to affect the thoracic spine and in other causes of osteomyelitis the lumbar spine is affected. Spinal disorders Dorsal column lesion Loss vibration and proprioception Tabes dorsalis, SACD Spinothalamic tract lesion Loss of pain, sensation and temperature Central cord lesion Flaccid paralysis of the upper limbs Osteomyelitis Normally progressive Staph aureus in IVDU, normally cervical region affected Fungal infections in immunocompromised Thoracic region affected in TB Infarction spinal cord Dorsal column signs (loss of proprioception and fine discrimination) Cord compression UMN signs Malignancy Haematoma Fracture Brown-sequard syndrome Hemisection of the spinal cord Ipsilateral paralysis Ipsilateral loss of proprioception and fine discrimination Contralateral loss of pain and temperature Dermatomes C2 to C4 The C2 dermatome covers the occiput and the top part of the neck. C3 covers the lower part of the neck to the clavicle. C4 covers the area just below the clavicle. C5 to T1 Situated in the arms. C5 covers the lateral arm at and above the elbow. C6 covers the forearm and the radial (thumb) side of the hand. C7 is the middle finger, C8 is the medial aspect of the hand, and T1 covers the medial side of the forearm. T2 to T12 The thoracic covers the axillary and chest region. T3 to T12 covers the chest and back to the hip girdle. The nipples are situated in the middle of T4. T10 is situated at the umbilicus. T12 ends just above the hip girdle. L1 to L5 The cutaneous dermatome representing the hip girdle and groin area is innervated by L1 spinal cord. L2 and 3 cover the front part of the thighs. L4 and L5 cover medial and lateral aspects of the lower leg. S1 to S5 S1 covers the heel and the middle back of the leg. S2 covers the back of the thighs. S3 cover the medial side of the buttocks and S4-5 covers the perineal region. S5 is of course the lowest dermatome and represents the skin immediately at and adjacent to the anus. Myotomes Upper limb Elbow flexors/Biceps C5 Wrist extensors C6 Elbow extensors/Triceps C7 Long finger flexors C8 Small finger abductors T1 Lower limb Hip flexors (psoas) L1 and L2 Knee extensors (quadriceps) L3 Ankle dorsiflexors (tibialis anterior) L4 and L5 Toe extensors (hallucis longus) L 5 Ankle plantar flexors (gastrocnemius) S1 The anal sphincter is innervated by S2,3,4

Answer 1387

This woman has raised ICP and mannitol will help reduce this in the acute phase. Head injury management- NICE Guidelines Summary of guidelines All patients should be assessed within 15 minutes on arrival to A&E Document all 3 components of the GCS If GCS <8 or = to 8, consider stabilising the airway Full spine immobilisation until assessment if: - GCS < 15 - neck pain/tenderness - paraesthesia extremities - focal neurological deficit - suspected c-spine injury If a c-spine injury is suspected a 3 view c-spine x-ray is indicated. CT c-spine is preferred if: - Intubated - GCS <13 - Normal x-ray but continued concerns regarding c-spine injury - Any focal neurology - A CT head scan is being performed - Initial plain films are abnormal Immediate CT head (within 1 hour) if: GCS < 12 on admission GCS < 15 2 hours after admission Suspected open or depressed skull fracture Suspected skull base fracture (panda eyes, Battle's sign, CSF from nose/ear, bleeding ear) Focal neurology Vomiting > 1 episode Post traumatic seizure Contact neurosurgeon if: Persistent GCS < 8 or = 8 Unexplained confusion > 4h Reduced GCS after admission Progressive neurological signs Incomplete recovery post seizure Penetrating injury Cerebrospinal fluid leak Observations 1/2 hourly GCS until 15 In the latest guidance, there is a move to considering CT in those on anticoagulants rather than mandating it. Reference 1. NICE Guidance NG 232 (Published 2023). 2. Hodgkinson S et al. Early management of head injury: summary of NICE guidance. BMJ 2014 (348):34-37.

Answer 1388

The swallowing issues here arise because the function of the middle pharyngeal constrictor is impaired. This muscle takes its origin from the lesser and greater cornu of the hyoid. During swallowing, the pharyngeal constrictor muscles force the food bolus into the oesophagus. Anterior anatomy of the neck Anterior triangle Boundaries Anterior border of the Sternocleidomastoid Lower border of mandible Anterior midline Sub triangles (divided by Digastric above and Omohyoid) Muscular triangle: Neck strap muscles Carotid triangle: Carotid sheath Submandibular Triangle (digastric) Contents of the anterior triangle Digastric triangle Submandibular gland Submandibular nodes Facial vessels Hypoglossal nerve Muscular triangle Strap muscles External jugular vein Carotid triangle Carotid sheath (Common carotid, vagus and internal jugular vein) Ansa cervicalis Nerve supply to digastric muscle Anterior: Mylohyoid nerve Posterior: Facial nerve Veins Veins of the neck are either superficial or deep to the deep fascia of the neck.Superficial tributaries of the external jugular vein drain a much smaller tissue volume than the tributaries of the internal jugular vein. The external jugular veins drains the superficial aspects of the scalp and neck. It commences as the union of the posterior divisions of the retromandibular and posterior auricular veins near the angle of the mandible either below or within the parotid. It then descends superficially from there to the mid aspect of the clavicle. It is covered by the platysma, superficial fascia and skin. The anterior jugular vein commences near the hyoid bone by the confluence of the superficial mandibular veins. It descends between the midline and the anterior border of the sternocleidomastoid. It eventually descends deep to this muscle to join either the external jugular or the subclavian vein. The internal jugular vein commences at the cranial base in the posterior compartment of the jugular foramen and is continuous with the sigmoid sinus. The vein is contained within the carotid sheath and eventually unites with the subclavian vein posterior to the sternal end of the clavicle. Surface marking of the internal jugular vein This is from the ear lobe to the medial end of the clavicle. The inferior bulb lies in a depression between the sternal and clavicular heads of the sternocleidomastoid, the lesser clavicular fossa. External carotid artery The external carotid commences immediately lateral to the pharyngeal side wall. It ascends and lies anterior to the internal carotid and posterior to the posterior belly of digastric and stylohyoid. More inferiorly it is covered by sternocleidomastoid, passed by hypoglossal nerves, lingual and facial veins. It then pierces the fascia of the parotid gland finally dividing into its terminal branches within the gland itself. Surface marking of the carotid This is an imaginary line drawn from the bifurcation of the common carotid passing behind the angle of the jaw to a point immediately anterior to the tragus of the ear. Branches of the external carotid artery It has six branches, three in front, two behind and one deep. Three in front Superior thyroid Lingual Facial Two behind Occipital Posterior auricular Deep Ascending pharyngeal It terminates by dividing into the maxillary and superficial temporal arteries.

Answer 1389

A rooftop incision is typically used to access the pancreas for resectional surgery. Abdominal incisions Midline incision Commonest approach to the abdomen Structures divided: linea alba, transversalis fascia, extraperitoneal fat, peritoneum (avoid falciform ligament above the umbilicus) Bladder can be accessed via an extraperitoneal approach through the space of Retzius Paramedian incision Parallel to the midline (about 3-4cm) Structures divided/retracted: anterior rectus sheath, rectus (retracted), posterior rectus sheath, transversalis fascia, extraperitoneal fat, peritoneum Incision is closed in layers Battle Similar location to paramedian but rectus displaced medially (and thus denervated) Now seldom used Kocher's Incision under right subcostal margin e.g. Cholecystectomy (open) Lanz Incision in right iliac fossa e.g. Appendicectomy Gridiron Oblique incision centered over McBurneys point- usually appendicectomy (less cosmetically acceptable than Lanz Gable Rooftop incision Pfannenstiel's Transverse supra pubic, primarily used to access pelvic organs McEvedy's Groin incision e.g. Emergency repair strangulated femoral hernia Rutherford Morrison Extraperitoneal approach to left or right lower quadrants. Gives excellent access to iliac vessels and is the approach of choice for first time renal transplantation.

Answer 1390

The sciatic nerve passes vertically downwards over the posterior surface of the obturator internus and quadratus femoris to the hamstring compartment of the thigh, here it is crossed posteriorly by the long head of biceps femoris. In the buttock it lies under the cover of gluteus maximus. It separates into its tibial and common peroneal components at the upper aspect of the popliteal fossa. Sciatic nerve The sciatic nerve is formed from the sacral plexus and is the largest nerve in the body. It is the continuation of the main part of the plexus arising from ventral rami of L4 to S3. These rami converge at the inferior border of piriformis to form the nerve itself. It passes through the inferior part of the greater sciatic foramen and emerges beneath piriformis. Medially, lie the inferior gluteal nerve and vessels and the pudendal nerve and vessels. It runs inferolaterally under the cover of gluteus maximus midway between the greater trochanter and ischial tuberosity. It receives its blood supply from the inferior gluteal artery. The nerve provides cutaneous sensation to the skin of the foot and the leg. It also innervates the posterior thigh muscles and the lower leg and foot muscles. The nerve splits into the tibial and common peroneal nerves approximately half way down the posterior thigh. The tibial nerve supplies the flexor muscles and the common peroneal nerve supplies the extensor muscles and the evertor muscles of the foot. Summary points Origin Spinal nerves L4 - S3 Articular Branches Hip joint Muscular branches in upper leg Semitendinosus Semimembranosus Biceps femoris Part of adductor magnus Cutaneous sensation Posterior aspect of thigh (via cutaneous nerves) Gluteal region Entire lower leg (except the medial aspect) Terminates At the upper part of the popliteal fossa by dividing into the tibial and peroneal nerves The nerve to the short head of the biceps femoris comes from the common peroneal part of the sciatic and the other muscular branches arise from the tibial portion. The tibial nerve goes on to innervate all muscles of the foot except the extensor digitorum brevis (which is innervated by the common peroneal nerve).

Answer 1391

The femoral nerve supplies the quadriceps muscle which is responsible for extension at the knee joint. Femoral nerve Root values L2, 3, 4 Innervates Pectineus Sartorius Quadriceps femoris Vastus lateralis/medialis/intermedius Rectus femoris Branches Medial cutaneous nerve of thigh Saphenous nerve Intermediate cutaneous nerve of thigh Path Penetrates psoas major and exits the pelvis by passing under the inguinal ligament to enter the femoral triangle, lateral to the femoral artery and vein. Mnemonic for femoral nerve supply (don't) M I S V Q Scan for PE M edial cutaneous nerve of the thigh I ntermediate cutaneous nerve of the thigh S aphenous nerve V astus Q uadriceps femoris S artorius PE ectineus

Answer 1392

The Denonvilliers fascia separates the rectum from the prostate. Waldeyers fascia separates the rectum from the sacrum Prostate gland The prostate gland is approximately the shape and size of a walnut and is located inferior to the bladder. It is separated from the rectum by Denonvilliers fascia and its blood supply is derived from the internal iliac vessels (via inferior vesical artery). The internal sphincter lies at the apex of the gland and may be damaged during prostatic surgery, affected individuals may complain of retrograde ejaculation. Summary of prostate gland Arterial supply Inferior vesical artery (from internal iliac) Venous drainage Prostatic venous plexus (to paravertebral veins) Lymphatic drainage Internal iliac nodes Innervation Inferior hypogastric plexus Dimensions Transverse diameter (4cm) AP diameter (2cm) Height (3cm) Lobes Posterior lobe: posterior to urethra Median lobe: posterior to urethra, in between ejaculatory ducts Lateral lobes x 2 Isthmus Zones Peripheral zone: subcapsular portion of posterior prostate. Most prostate cancers are here Central zone Transition zone Stroma Relations Anterior Pubic symphysis Prostatic venous plexus Posterior Denonvilliers fascia Rectum Ejaculatory ducts Lateral Venous plexus (lies on prostate) Levator ani (immediately below the puboprostatic ligaments)

Answer 1393

Rule of 2's 2% of population 2 inches (5cm) long 2 feet (60 cm) from the ileocaecal valve 2 x's more common in men 2 tissue types involved They are typically found 2 feet proximal to the ileocaecal valve (or approximately 60cm). Meckel's diverticulum - Congenital abnormality resulting in incomplete obliteration of the vitello-intestinal duct Normally, in the foetus, there is an attachment between the vitello-intestinal duct and the yolk sac.This disappears at 6 weeks gestation. The tip is free in majority of cases. Associated with enterocystomas, umbilical sinuses, and omphaloileal fistulas. Arterial supply: omphalomesenteric artery. 2% of population, 2 inches long, 2 feet from the ileocaecal valve. Typically lined by ileal mucosa but ectopic gastric mucosa can occur, with the risk of peptic ulceration. Pancreatic and jejunal mucosa can also occur. Clinical Normally asymptomatic and an incidental finding. Complications are the result of obstruction, ectopic tissue, or inflammation. Removal if narrow neck or symptomatic. Options are between wedge excision or formal small bowel resection and anastomosis.

Answer 1394

Tumour markers Tumour markers may be divided into: monoclonal antibodies against carbohydrate or glycoprotein tumour antigens tumour antigens enzymes (alkaline phosphatase, neurone specific enolase) hormones (e.g. calcitonin, ADH) It should be noted that tumour markers usually have a low specificity Monoclonal antibodies Tumour marker Association CA 125 Ovarian cancer CA 19-9 Pancreatic cancer CA 15-3 Breast cancer NB: The breast cancer tumour marker is not specific or sensitive enough to be used routinely. Tumour antigens Tumour marker Association Prostate specific antigen (PSA) Prostatic carcinoma Alpha-feto protein (AFP) Hepatocellular carcinoma, teratoma Carcinoembryonic antigen (CEA) Colorectal cancer

Answer 1395

Most colonic polyps described above are adenomas. These may have associated dysplasia. The more high grade the dysplasia the greater the level of clinical concern. Colonic polyps Colonic Polyps May occur in isolation, or greater numbers as part of the polyposis syndromes. In FAP greater than 100 polyps are typically present. The risk of malignancy in association with adenomas is related to size, and is the order of 10% in a 1cm adenoma. Isolated adenomas seldom give risk of symptoms (unless large and distal). Distally sited villous lesions may produce mucous and if very large, electrolyte disturbances may occur. Follow up of colonic polyps Group Action Colorectal cancer Colonoscopy 1 year post resection Large non pedunculated colorectal polyps (LNPCP), R0 resection One off scope at 3 years Large non pedunculated colorectal polyps (LNPCP) R1 or non en bloc resection Site check at 2-6 months and then a further scope at 12 months High risk findings at baseline colonoscopy One off surveillance at 3 years No high risk findings at baseline colonoscopy No colonoscopic surveillance and invite participation in NHSBCSP programme when due High risk findings More than 2 premalignant polyps including 1 or more advanced colorectal polyps OR More than 5 pre malignant polyps Exceptions to guidelines If patient more than 10 years younger than lower screening age and has polyps but no high risk findings, consider colonoscopy at 5 or 10 years. Segmental resection or complete colectomy should be considered when: 1. Incomplete excision of malignant polyp 2. Malignant sessile polyp 3. Malignant pedunculated polyp with submucosal invasion 4. Polyps with poorly differentiated carcinoma 5. Familial polyposis coli -Screening from teenager up to 40 years by 2 yearly sigmoidoscopy/colonoscopy -Panproctocolectomy and Ileostomy or Restorative Panproctocolectomy. Rectal polypoidal lesions may be amenable to trans anal endoscopic microsurgery. References Rutter MD et al. British Society of Gastroenterology/Association of Coloproctology of Great Britain and Ireland/Public Health England post- polypectomy and post- colorectal cancer resection surveillance guidelines. Gut 2019;0:123.

Answer 1396

The gluteus maximus is supplied by the inferior gluteal nerve. Anatomy of the pelvis The pelvic girdle formed by the union of the two innominate bones anteriorly at the pubis and posteriorly with their connection to the sacrum. The innominate bone is comprised of three main parts; ilium, ischium and pubis. In the young, these are connected by cartilagenous tissue. In adults, they unite as one bone. The dimensions of the bony pelvis differ in the two sexes, being shallower and wider in females and narrower and deeper in males. Pelvic ligaments The pelvic bony structures are interconnected by a series of ligaments. These assume clinical significance during pregnancy and childbirth as they develop increased laxity at this time. Potential exits Sites at which important anatomical structures exit the abdomen through the pelvis are commonly examined. These include the obturator, inguinal and femoral canals anteriorly. Inferiorly, the sciatic foramina also transmit structures. These are all covered separately in the resource. Gluteal region Gluteal muscles Gluteus maximus: inserts to gluteal tuberosity of the femur and iliotibial tract Gluteus medius: attach to lateral greater trochanter Gluteus minimis: attach to anterior greater trochanter All extend and abduct the hip Deep lateral hip rotators Piriformis Gemelli Obturator internus Quadratus femoris Nerves Superior gluteal nerve (L5, S1) Gluteus medius Gluteus minimis Tensor fascia lata Inferior gluteal nerve Gluteus maximus Damage to the superior gluteal nerve will result in the patient developing a Trendelenberg gait. Affected patients are unable to abduct the thigh at the hip joint. During the stance phase, the weakened abductor muscles allow the pelvis to tilt down on the opposite side. To compensate, the trunk lurches to the weakened side to attempt to maintain a level pelvis throughout the gait cycle. The pelvis sags on the opposite side of the lesioned superior gluteal nerve. Anatomy of the sciatic foramina is covered separately

Answer 1397

There is strong evidence to support the use of haemostatic transfusion in the setting of major haemorrhage due to trauma. This advocates the use of 1:1:1 ratios. Transfusions in major trauma Uncontrolled haemorrhage accounts for up to 39% of all trauma related death. In the UK approximately 2% of all trauma patients will need massive transfusion.Massive transfusion is defined as the replacement of a patient's total blood volume in less than 24 hours, or as the acute administration of more than half the patient's estimated blood volume per hour. In haemorrhaging patients following trauma there is evidence to support the initial administration of tranexamic acid (CRASH study). During acute bleeding the practice of haemostatic resuscitation has been shown to reduce mortality rates. The principle of haemostatic resuscitation is that blood components are transfused in fixed ratios. For example; packed red cells, FFP and platelets are administered in a ratio of 1:1:1. The typical therapeutic end points include: Hb: 8-10 g/dl Platelets > 100 PT (INR) and APTT < 1.5 Fibrinogen > 1.0 g/l Ca2+ > 1 mmol/l pH: 7.35-7.45 BE: +/- 2 ToC > 36 Â°C Reference Weymouth W et al. Whole Blood in Trauma: A Review for Emergency Clinicians. J Emerg Med. 2019 May;56(5):491-498.

Answer 1398

E-Metastatic gastric carcinoma Mnemonic 3-2-1 for HNPCC. 3 individuals, 2 generations and one must be younger than 50 yrs. Lynch syndrome usually results in colonic cancer which is right sided and mucinous. The next most common site to be affected is the uterus. The stomach is at particular risk and this risk is up to 10 times greater in HNPCC (Lynch) patients than the general population. Duodenal adenomas (and rarely carcinoma) are usually seen in association with FAP. Whilst pancreatic carcinoma is associated with HNPCC it is far less likely to occur than gastric cancer. We are often asked how these patients become jaundiced, this occurs as a result of nodal spread along the hepatoduodenal ligament nodes to occlude the porta hepatis resulting in jaundice. Genetics of colorectal cancer The lifetime risk of colorectal cancer in the UK population is 5%. Up to 5% of newly diagnosed bowel cancers will be in those individuals who have a high genetically acquired risk of bowel cancer. Cancers arising in the low-moderate genetic risk group comprise approximately 30% of newly diagnosed bowel cancer. Genetics of inherited colorectal cancer syndromes Syndrome Features Genes implicated FAP More than 100 adenomatous polyps affecting the colon and rectum. Duodenal and fundic glandular polyps APC (over 90%) Gardner syndrome As FAP but with desmoid tumours and mandibular osteomas APC Turcots syndrome Polyposis and colonic tumours and CNS tumours APC +MLH1 and PMS2 HNPCC Colorectal cancer without extensive polyposis. Endometrial cancer, renal and CNS MSH2, MLH1, PMS2 and GTBP Peutz-Jeghers syndrome Hamartomatous polyps in GI tract and increased risk of GI malignancy LKB1 andSTK11 (in up to 70%) Cowden disease Multiple hamartomas (see below) PTEN (85%) MYH associated polyposis Autosomal recessive, multiple adenomatous polyps in GI tract, those in colon having somatic KRAS mutations MYH FAP Autosomal dominant condition, affects 1 in 12,000. Accounts for 0.5% of all CRCs. Lifetime incidence of colorectal cancer in untreated FAP =100%. Up to 25% cases are caused by de-novo germ line mutations and show no prior family history. The APC tumour suppressor gene is affected in most cases. APC in non inherited colorectal cancer Up to 80% of sporadic colorectal cancers will have somatic mutations that inactivate APC[1]. Both alleles are usually affected. Although the APC protein more than likely has multiple critical cellular functions, the best-established role for APC in the cancer process is as a major binding partner and regulator of the β- catenin protein in the so-called canonical or β- catenin dependent Wnt signaling pathway. HNPCC (Lynch syndrome) HNPCC cancers differ from conventional tumours in a number of respects. In the colon the tumours are more likely to be right sided, histologically they are more likely to be mucinous and have dense lymphocytic infiltrates. To be diagnosed as having HNPCC individuals must show typically HNPCC tumours in at least three individuals, (one of whom must be a first degree relative to the other two). In at least two successive generations. At least one cancer must be diagnosed under the age of 50. FAP must be excluded and tumours should be verified by pathological identification (Amsterdam criteria). The genetic changes in HNPCC stem primarily from microsatellite instability affecting DNA mismatch repair genes. In HNPCC the mismatch repair genes most commonly implicated include; MSH2 and MLH1 and these occur in up to 70% of people with HNPCC. The finding of microsatellite instability is unusual in sporadic colorectal cancers. Approximately 60% of individuals who fulfill the Amsterdam criteria will not be found to have evidence of mismatch repair gene defects on genetic testing. The risk of developing colorectal cancer in those who have not demonstrated mutation of the mis match repair genes is increased if they fulfill the Amsterdam criteria, but not the extent that it is increased in those who fulfill the criteria AND have evidence of mis match repair gene defects. KRAS Mutations The RAS family of small G proteins act as molecular switches downstream of growth factor receptors. KRAS and the other two members of the family; HRAS and NRAS, are the site of mutation in approximately 40% of colorectal cancers. When adenomas are examined the proportion of adenomas less than 1cm showing KRAS mutations was only 10% which contrasts with 50% in those lesions greater than 1cm. p53 mutations The p53 protein functions as a key transcriptional regulator of genes that encode proteins with functions in cell-cycle checkpoints at the G1/S and G2/M boundaries, in promoting apoptosis, and in restricting angiogenesis . As such, selection for p53 defects at the adenoma-carcinoma transition may reflect the fact that stresses on tumor cells activate cell-cycle arrest, apoptotic, and antiangiogenic pathways in cells with wild-type p53 function. Many colonic tumours will demonstrate changes in the p53 gene that may facilitate tumour progression through from adenoma to carcinoma. Cowden syndrome Also known as multiple hamartoma syndrome. Rare autosomal dominant condition with incidence of 1 in 200,000.. It is characterised by multiple mucocutaneous lesions, trichilemmomas, oral papillomas and acral keratosis. Most often diagnosed in third decade of life. Breast carcinoma may occur in up to 50% of patients and conditions such as fibrocystic disease of the breast may occur in 75% of women. Thyroid disease occurs in 75% and may include malignancy. Endoscopic screening will identify disease in up to 85% although the small bowel is rarely involved. There is a 15-20% risk of developing colorectal cancer and regular colonoscopic screening from age 45 is recommended. Terminology Oncogene Oncogenes are genes which have the potential to induce cellular proliferation and avoid apoptosis. Oncogene mutations are general gain of function and are therefore dominant. Increased expression of oncogenes are found in most tumours Tumour suppressor gene These genes generally inhibit cellular proliferation or induce apoptosis. Mutations in tumour suppressor genes are generally loss of function mutations, and are therefore recessive. Mutations in both tumour suppressor gene alleles allow cells to proliferate without restraint References 1. Fearon, E.R. and B. Vogelstein, A genetic model for colorectal tumorigenesis. Cell, 1990. 61(5): p. 759-67.

Answer 1399

Follicular carcinomas may metastasise haematogenously (often to bone) where they may give rise to pathological fractures as in this case. Thyroid disease Patients may present with a number of different manifestations of thyroid disease. They can be broadly sub classified according to whether they are euthyroid or have clinical signs of thyroid dysfunction. In addition it needs to be established whether they have a mass or not. Assessment History Examination including USS If a nodule is identified then it should be sampled ideally via an image guided fine needle aspiration Radionucleotide scanning is of limited use Thyroid Tumours Papillary carcinoma Follicular carcinoma Anaplastic carcinoma Medullary carcinoma Lymphoma's Multinodular goitre One of the most common reasons for presentation Provided the patient is euthyroid and asymptomatic and no discrete nodules are seen, they can be reassured. In those with compressive symptoms surgery is required and the best operation is a total thyroidectomy. Sub total resections were practised in the past and simply result in recurrent disease that requires a difficult revisional resection. Endocrine dysfunction In general these patients are managed by physicians initially. Surgery may be offered alongside radio iodine for patients with Graves disease that fails with medical management or in patients who would prefer not to be irradiated (e.g. pregnant women). Patients with hypothyroidism do not generally get offered a thyroidectomy. Sometimes people inadvertently get offered resections during the early phase of Hashimotos thyroiditis, however, with time the toxic phase passes and patients can simply be managed with thyroxine. Complications following surgery Anatomical such as recurrent laryngeal nerve damage. Bleeding. Owing to the confined space haematoma's may rapidly lead to respiratory compromise owing to laryngeal oedema. Damage to the parathyroid glands resulting in hypocalcaemia. Further sources of information 1. http://www.acb.org.uk/docs/TFTguidelinefinal.pdf- Association of Clinical Biochemistry guidelines for thyroid function tests. 2. British association of endocrine surgeons website- http://www.baets.org.uk

Answer 1400

Temporal artery biopsies are frequently non diagnostic. They should be taken from the symptomatic side and though not mandatory a duplex ultrasound is a helpful investigation, particularly if they mark the artery. It is usually performed under local anaesthetic. Temporal artery biopsy Superficial temporal artery is a terminal branch of the external carotid artery Main indication Temporal arteritis American College of Rheumatology guidelines recommend a temporal artery biopsy if: Age of onset older than 50 years New-onset headache or localized head pain Temporal artery tenderness to palpation or reduced pulsation ESR > 50 mm/h Histopathology Vessel wall granulomatous arteritis with mononuclear cell infiltrates and giant cell formation Procedure Position: supine, head 45 degrees USS doppler to locate the superficial temporal artery or palpate Local anaesthetic Artery within temporoparietal fascia Clamp and ligate the vessel Cut 3-5cm Ligate the remaining ends with absorbable suture Close the skin Contraindication Glucocorticoid therapy > 30 days Risks Injury to facial or auriculotemporal nerve

Answer 1401

Le Fort II fractures have a pyramidal shape. The fracture line involves the orbit and extends to involve the bridge of the nose and the ethmoids. In continues to involve the infraorbital rim and usually through the infraorbital foramen. As a result infraorbital parasthesia, palatal mobility and malocclusion are common findings. Severe fractures may result in enopthalmos. However, the fracture does not, by definition, involve the inferior alveolar nerve. Craniomaxillofacial injuries Craniomaxillofacial injuries in the UK are due to: Interpersonal violence (52%) Motor vehicle accidents (16%) Sporting injuries (19%) Falls (11%) Le Fort Fractures Grade Feature Le Fort 1 The fracture extends from the nasal septum to the lateral pyriform rims, travels horizontally above the teeth apices, crosses below the zygomaticomaxillary junction, and traverses the pterygomaxillary junction to interrupt the pterygoid plates. Le Fort 2 These fractures have a pyramidal shape and extend from the nasal bridge at or below the nasofrontal suture through the frontal process of the maxilla, inferolaterally through the lacrimal bones and inferior orbital floor and rim through or near the inferior orbital foramen, and inferiorly through the anterior wall of the maxillary sinus; it then travels under the zygoma, across the pterygomaxillary fissure, and through the pterygoid plates. Le Fort 3 These fractures start at the nasofrontal and frontomaxillary sutures and extend posteriorly along the medial wall of the orbit through the nasolacrimal groove and ethmoid bones. The thicker sphenoid bone posteriorly usually prevents continuation of the fracture into the optic canal. Instead, the fracture continues along the floor of the orbit along the inferior orbital fissure and continues superolaterally through the lateral orbital wall, through the zygomaticofrontal junction and the zygomatic arch. Intranasally, a branch of the fracture extends through the base of the perpendicular plate of the ethmoid, through the vomer, and through the interface of the pterygoid plates to the base of the sphenoid. This type of fracture predisposes the patient to CSF rhinorrhea more commonly than the other types. Ocular injuries Superior orbital fissure syndrome Severe force to the lateral wall of the orbit resulting in compression of neurovascular structures. Results in : Complete opthalmoplegia and ptosis (Cranial nerves 3, 4, 6 and nerve to levator palpebrae superioris) Relative afferent pupillary defect Dilatation of the pupil and loss of accommodation and corneal reflexes Altered sensation from forehead to vertex (frontal branch of trigeminal nerve) Orbital blow out fracture Typically occurs when an object of slightly larger diameter than the orbital rim strikes the incompressible eyeball. The bone fragment is displaced downwards into the antral cavity, remaining attached to the orbital periosteum. Periorbital fat may be herniated through the defect, interfering with the inferior rectus and inferior oblique muscles which are contained within the same fascial sheath. This prevents upward movement and outward rotation of the eye and the patient experiences diplopia on upward gaze. The initial bruising and swelling may make assessment difficult and patients should usually be reviewed 5 days later. Residual defects may require orbital floor reconstruction. Nasal Fractures Common injury Ensure new and not old deformity Control epistaxis CSF rhinorrhoea implies that the cribriform plate has been breached and antibiotics will be required. Usually best to allow bruising and swelling to settle and then review patient clinically. Major persistent deformity requires fracture manipulation, best performed within 10 days of injury. Retrobulbar haemorrhage Rare but important ocular emergency. Presents with: Pain (usually sharp and within the globe) Proptosis Pupil reactions are lost Paralysis (eye movements lost) Visual acuity is lost (colour vision is lost first) May be the result of Le Fort type facial fractures. Management: Mannitol 1g/Kg as 20% infusion, Osmotic diuretic, Contra-indicated in congestive heart failure and pulmonary oedema Acetazolamide 500mg IV, (Monitor FBC/U+E) Reduces aqueous pressure by inhibition of carbonic anhydrase (used in glaucoma) Dexamethasone 8mg orally or intravenously In a traumatic setting an urgent cantholysis may be needed prior to definitive surgery. Consider Papaverine 40mg smooth muscle relaxant Dextran 40 500mls IV improves perfusion

Answer 1402

Structures within the right atrium: Musculi pectinati Crista terminalis Opening of the coronary sinus Fossa ovalis The trabeculae carnae are located in the right ventricle. Heart anatomy The walls of each cardiac chamber comprise: Epicardium Myocardium Endocardium Cardiac muscle is attached to the cardiac fibrous skeleton. Relations The heart and roots of the great vessels within the pericardial sac are related to the posterior aspect of the sternum, medial ends of the 3rd to 5th ribs on the left and their associated costal cartilages. The heart and pericardial sac are situated obliquely two thirds to the left and one third to the right of the median plane. The pulmonary valve lies at the level of the left third costal cartilage. The mitral valve lies at the level of the fourth costal cartilage. Coronary sinus This lies in the posterior part of the coronary groove and receives blood from the cardiac veins. The great cardiac vein lies at its left and the middle and small cardiac veins lie on its right. The smallest cardiac vein (anterior cardiac vein) drains into the right atrium directly. Aortic sinus Right coronary artery arises from the right aortic sinus, the left is derived from the left aortic sinus, which lies posteriorly. Features of the left ventricle as opposed to the right Structure Left Ventricle A-V Valve Mitral (double leaflet) Walls Twice as thick as right Trabeculae carnae Much thicker and more numerous Right coronary artery The RCA supplies: Right atrium Diaphragmatic part of the right ventricle Usually the posterior third of the interventricular septum The sino atrial node (60% cases) The atrio ventricular node (80% cases) Left coronary artery The LCA supplies: Left atrium Most of left ventricle Part of the right ventricle Anterior two thirds of the inter ventricular septum The sino atrial node (remaining 40% cases) Innervation of the heart Autonomic nerve fibres from the superficial and deep cardiac plexus. These lie anterior to the bifurcation of the trachea, posterior to the ascending aorta and superior to the bifurcation of the pulmonary trunk. The parasympathetic supply to the heart is from presynaptic fibres of the vagus nerves. Valves of the heart Mitral valve Aortic valve Pulmonary valve Tricuspid valve 2 cusps 3 cusps 3 cusps 3 cusps First heart sound Second heart sound Second heart sound First heart sound 1 anterior cusp 2 anterior cusps 2 anterior cusps 2 anterior cusps Attached to chordae tendinae No chordae No chordae Attached to chordae tendinae

Answer 1403

The trunks are related to the subclavian artery superiorly. The cords of the plexus surround the axillary artery, they are named according to their positions relative to this structure. Brachial plexus The brachial plexus extends from the neck to the axilla. It is formed by the ventral rami of the fifth to the eighth cervical nerves with the ascending part of the first thoracic nerve. Location of the plexus The ventral rami which form the plexus enter the lower part of the posterior triangle of the neck in series with the ventral rami of the cervical plexus. The second part of the subclavian artery lies immediately anterior to the lower two rami. The upper three rami intermingle and pass inferolaterally towards the axilla and subclavian artery. They are enclosed within an extension of the prevertebral fascia. In the neck the plexus lies deep to platysma, the supraclavicular nerves, inferior belly of omohyoid and the transverse cervical artery. It then passes deep to the clavicle and the suprascapular vessels, to enter the axilla, and thence surround the second part of the axillary artery Composition of the plexus Ventral rami, the roots of the plexus, lie between scalenus medius and anterior. As they enter the posterior triangle, the upper two (C5,6) and lower two (C8, T1) roots of the plexus unite to form the upper and lower trunks of the plexus respectively. Meanwhile, C7 continues as the middle trunk. The lower trunk may groove the superior surface of the first rib posterior to the subclavian artery, and the root from the first ventral ramus is always in contact with it. Each trunk divides into ventral and dorsal divisions which are destined to supply the anterior (flexor) and posterior (extensor) parts of the upper limb. The cords of the plexus are formed in the axilla. The dorsal divisions unite to form the posterior cord (C5-8). The ventral divisions of the upper and middle trunks unite to form the lateral cord (C5-7), while the ventral divisions of the lower trunk continues as the medial cord (C8-T1). The cords are named according to their relationship to the axillary artery. Each cord terminates by dividing into two main branches at the beginning of the third part of the artery. Sympathetic communications The fifth and sixth cervical ventral rami receive grey rami communicantes from the middle cervical ganglion, while the two or more grey rami communicantes pass from the inferior cervical ganglion to the seventh and eighth cervical ventral rami. The first thoracic ventral ramus receives its grey ramus from the cervicothoracic ganglion. Its for this reason that inferior plexus injury can be complicated by a Horners syndrome. Summary Origin Anterior rami of C5 to T1 Sections of the plexus Roots, trunks, divisions, cords, branches Mnemonic:Real Teenagers Drink Cold Beer Roots Located in the posterior triangle Pass between scalenus anterior and medius Trunks Located posterior to middle third of clavicle Upper and middle trunks related superiorly to the subclavian artery Lower trunk passes over 1st rib posterior to the subclavian artery Divisions Apex of axilla Cords Related to axillary artery

Answer 1404

The biceps femoris is commonly injured in sports that require explosive bending of the knee as seen in sprinting, especially if the athlete has not warmed up first. Avulsion most commonly occurs where the long head attaches to the ischial tuberosity. Injuries to biceps femoris are more common than to the other hamstrings. Biceps femoris The biceps femoris is one of the hamstring group of muscles located in the posterior upper thigh. It has two heads. Long head Origin Ischial tuberosity Insertion Fibular head Action Knee flexion, lateral rotation tibia, extension hip Innervation Tibial division of sciatic nerve (L5, S1, S2) Arterial supply Profunda femoris artery, inferior gluteal artery, and the superior muscular branches of popliteal artery Short head Origin Lateral lip of linea aspera, lateral supracondylar ridge of femur Insertion Fibular head Action Knee flexion, lateral rotation tibia Innervation Common peroneal division of sciatic nerve (L5, S1, S2) Arterial supply Profunda femoris artery, inferior gluteal artery, and the superior muscular branches of popliteal artery

Answer 1405

The quadriceps femoris lies in the anterior compartment. Fascial compartments of the leg Compartments of the thigh Formed by septae passing from the femur to the fascia lata. Compartment Nerve Muscles Blood supply Anterior compartment Femoral Iliacus Tensor fasciae latae Sartorius Quadriceps femoris Femoral artery Medial compartment Obturator Adductor longus/magnus/brevis Gracilis Obturator externus Profunda femoris artery and obturator artery Posterior compartment (2 layers) Sciatic Semimembranosus Semitendinosus Biceps femoris Branches of Profunda femoris artery Compartments of the lower leg Separated by the interosseous membrane (anterior and posterior compartments), anterior fascial septum (separate anterior and lateral compartments) and posterior fascial septum (separate lateral and posterior compartments) Compartment Nerve Muscles Blood supply Anterior compartment Deep peroneal nerve Tibialis anterior Extensor digitorum longus Extensor hallucis longus Peroneus tertius Anterior tibial artery Posterior compartment Tibial Muscles: deep and superficial compartments (separated by deep transverse fascia) Deep: Flexor hallucis longus, Flexor digitalis longus, Tibialis posterior, Popliteus Superficial: Gastrocnemius, Soleus, Plantaris Posterior tibial Lateral compartment Superficial peroneal Peroneus longus/brevis Peroneal artery

Answer 1406

Many umbilical hernias will close in the first year of life. Defer surgery until the child is 3 years or older. Paediatric umbilical disorders Embryology During development the umbilicus has two umbilical arteries and one umbilical vein. The arteries are continuous with the internal iliac arteries and the vein is continuous with the falciform ligament (ductus venosus). After birth the cord dessicates and separates and the umbilical ring closes. Umbilical hernia Up to 20% of neonates may have an umbilical hernia, it is more common in premature infants. The majority of these hernias will close spontaneously (may take between 12 months and three years). Strangulation is rare. Paraumbilical hernia These are due to defects in the linea alba that are in close proximity to the umbilicus. The edges of a paraumbilical hernia are more clearly defined than those of an umbilical hernia. They are less likely to resolve spontaneously than an umbilical hernia. Omphalitis This condition consists of infection of the umbilicus. Infection with Staphylococcus aureus is the commonest cause. The condition is potentially serious as infection may spread rapidly through the umbilical vessels in neonates with a risk of portal pyaemia, and portal vein thrombosis. Treatment is usually with a combination of topical and systemic antibiotics. Umbilical granuloma These consist of cherry red lesions surrounding the umbilicus, they may bleed on contact and be a site of seropurulent discharge. Infection is unusual and they will often respond favorably to chemical cautery with topically applied silver nitrate. Persistent urachus This is characterised by urinary discharge from the umbilicus. It is caused by persistence of the urachus which attaches to the bladder. They are associated with other urogenital abnormalities. Persistent vitello-intestinal duct This will typically present as an umbilical discharge that discharges small bowel content. Complete persistence of the duct is a rare condition. Much more common is the persistence of part of the duct (Meckels diverticulum). Persistent vitello-intestinal ducts are best imaged using a contrast study to delineate the anatomy and are managed by laparotomy and surgical closure.

Answer 1407

When approaching the submandibular gland the facial vein and submandibular lymph nodes are the most superficially encountered structures. Each sub mandibular gland has a superficial and deep part, separated by the mylohyoid muscle. The facial artery passes in a groove on the superficial aspect of the gland. It then emerges onto the surface of the face by passing between the gland and the mandible. The facial vein is encountered first in this surgical approach because the incision is made 4cm below the mandible (to avoid injury to the marginal mandibular nerve). Submandibular gland Relations of the submandibular gland Superficial Platysma, deep fascia and mandible Submandibular lymph nodes Facial vein (facial artery near mandible) Marginal mandibular nerve Cervical branch of the facial nerve Deep Facial artery (inferior to the mandible) Mylohyoid muscle Sub mandibular duct Hyoglossus muscle Lingual nerve Submandibular ganglion Hypoglossal nerve Submandibular duct (Wharton's duct) Opens lateral to the lingual frenulum on the anterior floor of mouth. 5 cm length Lingual nerve wraps around Wharton's duct. As the duct passes forwards it crosses medial to the nerve to lie above it and then crosses back, lateral to it, to reach a position below the nerve. Innervation Sympathetic innervation- Derived from superior cervical ganglion Parasympathetic innervation- Submandibular ganglion via lingual nerve Arterial supply Branch of the facial artery. The facial artery passes through the gland to groove its deep surface. It then emerges onto the face by passing between the gland and the mandible. Venous drainage Anterior facial vein (lies deep to the Marginal Mandibular nerve) Lymphatic drainage Deep cervical and jugular chains of nodes

Answer 1408

B-Bi temporal hemianopia The patient is most likely to have developed acromegaly. Since a pituitary lesion is likely to be present; compression of the optic chiasm may occur. Visual field defects left homonymous hemianopia means visual field defect to the left, i.e. Lesion of right optic tract homonymous quadrantanopias: PITS (Parietal-Inferior, Temporal-Superior) incongruous defects = optic tract lesion; congruous defects = optic radiation lesion or occipital cortex Homonymous hemianopia Incongruous defects: lesion of optic tract Congruous defects: lesion of optic radiation or occipital cortex Macula sparing: lesion of occipital cortex Homonymous quadrantanopias Superior: lesion of temporal lobe Inferior: lesion of parietal lobe Mnemonic = PITS (Parietal-Inferior, Temporal-Superior) Bitemporal hemianopia Lesion of optic chiasm Upper quadrant defect > lower quadrant defect = inferior chiasmal compression, commonly a pituitary tumour Lower quadrant defect > upper quadrant defect = superior chiasmal compression, commonly a craniopharyngioma

Answer 1409

Central lines (and particularly subclavian lines) are risk factors for the development of pneumothorax. In the context of positive pressure ventilation a tension pneumothorax is a strong possibility and would be associated with haemodynamic instability. Intravenous access Venous access A number of routes for establishing venous access are available. Peripheral venous cannula Easy to insert with minimal morbidity. Wide lumen cannulae can provide rapid fluid infusions. When properly managed infections may be promptly identified and the cannula easily re sited. Problems relate to their peripheral sites and they are unsuitable for the administration of vaso active drugs, such as inotropes and irritant drugs such as TPN (except in the very short term setting). Central lines Insertion is more difficult and most operators and NICE advocate the use of ultra sound. Coagulopathies may lead to haemorrhage following iatrogenic arterial injury. Femoral lines are easier to insert and iatrogenic injuries easier to manage in this site however they are prone to high infection rates. Internal jugular route is preferred. They have multiple lumens allowing for administration of multiple infusions. The lumens are relatively narrow and thus they do not allow particularly rapid rates of infusion. Intraosseous access This is typically undertaken at the anteromedial aspect of the proximal tibia and provides access to the marrow cavity and circulatory system. Although traditionally preferred in paediatric practice they may be used in adults and a wide range of fluids can be infused using these devices. Tunneled lines Tunneled lines such as Groshong and Hickman lines are popular devices for patients with long term therapeutic requirements. These devices are usually inserted using ultrasound guidance into the internal jugular vein and then tunneled under the skin. A cuff of woven material is sited near the end and helps to anchor the device into the tissues. These cuffs require formal dissection to allow the device to be removed. Tunneled lines can be linked to injection ports that are located under the skin. These are especially popular in paediatric practice. Peripherally inserted central cannula Referred to as PICC lines, these are popular methods for establishing central venous access. Because they are inserted peripherally they are less prone to major complications relating to device insertion than conventional central lines.

Answer 1410

Nodal status is the single most important prognostic factor in breast cancer. Nodal status is important because it serves as a marker of tumour metastatic potential. This translates to survival advantages of up to 40% at five years. Both grade and size are of secondary importance as they both less concerning in the absence of nodal involvement. Breast cancer - Commoner in the older age group Invasive ductal carcinomas are the most common type. Some may arise as a result of ductal carcinoma in situ (DCIS). There are associated carcinomas of special type e.g. Tubular that may carry better prognosis. The pathological assessment involves assessment of the tumour and lymph nodes, sentinel lymph node biopsy is often used to minimise the morbidity of an axillary dissection. Treatment, typically this is either wide local excision or mastectomy. There are many sub types of both of these that fall outside of the MRCS. Some key rules to bear in mind. Whatever operation is contemplated the final cosmetic outcome does have a bearing. A woman with small breasts and a large tumour will tend to fare better with mastectomy, even if clear pathological and clinical margins can be obtained. Conversely a women with larger breasts may be able to undergo breast conserving surgery even with a relatively large primary lesion (NB tumours >4cm used to attract recommendation for mastectomy). For screen detected and impalpable tumour image guidance will be necessary. Reconstruction is always an option following any resectional procedure. However, its exact type must be tailored to age and co-morbidities of the patient. The main operations in common use include latissimus dorsi myocutaneous flap and sub pectoral implants. Women wishing to avoid a prosthesis may be offered TRAM or DIEP flaps. Surgical options Mastectomy vs Wide local excision Mastectomy Wide Local Excision Multifocal tumour Solitary lesion Central tumour Peripheral tumour Large lesion in small breast Small lesion in large breast DCIS >4cm DCIS <4cm Patient Choice Patient choice Central lesions may be managed using breast conserving surgery where an acceptable cosmetic result may be obtained, this is rarely the case in small breasts Whatever surgical option is chosen the aim should be to have a local recurrence rate of 5% or less at 5 years [1]. Nottingham Prognostic Index The Nottingham Prognostic Index can be used to give an indication of survival. In this system the tumour size is weighted less heavily than other major prognostic parameters. Calculation of NPI Tumour Size x 0.2 + Lymph node score(From table below)+Grade score(From table below). Score Lymph nodes involved Grade 1 0 1 2 1-3 2 3 >3 3 Prognosis Score Percentage 5 year survival 2.0 to 2.4 93% 2.5 to 3.4 85% 3.5 to 5.4 70% >5.4 50% This data was originally published in 1992. It should be emphasised that other factors such as vascular invasion and receptor status also impact on survival and are not included in this data and account for varying prognoses often cited in the literature. References For guidance on how breast cancer is managed in the United Kingdom visit the Association of Breast Surgery website (www.https://associationofbreastsurgery.org.uk/).

Answer 1411

The rhesus group is not important in matching donor and recipient kidneys. Renal transplant:HLA typing and graft failure The human leucocyte antigen (HLA) system is the name given to the major histocompatibility complex (MHC) in humans. It is coded for on chromosome 6. Some basic points on the HLA system Class 1 antigens include A, B and C. Class 2 antigens include DP,DQ and DR When HLA matching for a renal transplant the relative importance of the HLA antigens are as follows DR > B > A Graft survival 1 year = 90%, 10 years = 60% for cadaveric transplants 1 year = 95%, 10 years = 70% for living-donor transplants Post-op problems ATN of graft Vascular thrombosis Urine leakage UTI Hyperacute acute rejection Due to antibodies against donor HLA type 1 antigens Rarely seen due to HLA matching Acute graft failure (< 6 months) Usually due to mismatched HLA Other causes include cytomegalovirus infection Management: give steroids, if resistant use monoclonal antibodies Causes of chronic graft failure (> 6 months) Chronic allograft nephropathy Ureteric obstruction Recurrence of original renal disease (MCGN > IgA > FSGS)

Answer 1412

This woman has been resuscitated and requires transfer for specialist management. Burns Burns may be thermal, chemical or electrical. In the former category are burns which occur as a result of heat. Chemical burns occur when the skin is exposed to an extremely caustic or alkaline substance. Electrical burns occur following exposure to electrical current. The immediate management includes removal of the burning source which usually includes irrigation of the burned area. A detailed assessment then needs to be made of the extent of the burns and a number of charts are available for recording this information. The degree of injury relates to the temperature and duration of exposure. Most domestic burns are mainly scalds in young children. Following the burn, there is a local response with progressive tissue loss and release of inflammatory cytokines. Systemically, there are cardiovascular effects resulting from fluid loss and sequestration of fluid into the third space. There is a marked catabolic response. Immunosuppression is common with large burns and bacterial translocation from the gut lumen is a recognised event. Sepsis is a common cause of death following major burns. Types of burn Type of burn Skin layers affected Skin appearance Blanching Management Epidermal/Superficial Epidermis Red, moist Yes Superficial partial thickness Epidermis and part of papillary dermis affected Pale, dry Yes Normally heals with no intervention Deep partial thickness Epidermis, whole papillary dermis affected Mottled red colour No Needs surgical intervention (depending on site) Full thickness Whole skin layer and subcutaneous tissue affected Dry, leathery hard wound No Burns centre Depth of burn assessment Bleeding on needle prick Sensation Appearance Blanching to pressure Percentage burn estimation Lund Browder chart: most accurate even in children Wallace rule of nines Palmar surface: surface area palm = 0.8% burn >15% body surface area burns in adults needs urgent burn fluid resuscitation Transfer to burn centre if: Need burn shock resuscitation Face/hands/genitals affected Deep partial thickness or full thickness burns Significant electrical/chemical burns Management The initial aim is to stop the burning process and resuscitate the patient. Intravenous fluids will be required for children with burns greater than 10% of total body surface area. Adults with burns greater than 15% of total body surface area will also require IV fluids. The fluids are calculated using the Parkland formula which is; volume of fluid= total body surface area of the burn % x weight (Kg) x2-4 (preference for lower amount i.e. 2ml to avoid excessive fluid overload). Half of the fluid is administered in the first 8 hours. A urinary catheter should be inserted. Analgesia should be given. Complex burns, burns involving the hand perineum and face and burns >10% in adults and >5% in children should be transferred to a burns unit. Circumferential burns affecting a limb or severe torso burns impeding respiration may require escharotomy to divide the burnt tissue. Conservative management is appropriate for superficial burns and mixed superficial burns that will heal in 2 weeks. More complex burns may require excision and skin grafting. Excision and primary closure is not generally practised as there is a high risk of infection. There is no evidence to support the use of anti microbial prophylaxis or topical antibiotics in burn patients. Escharotomies Indicated in circumferential full thickness burns to the torso or limbs. Careful division of the encasing band of burn tissue will potentially improve ventilation (if the burn involves the torso), or relieve compartment syndrome and oedema (where a limb is involved) References www.euroburn.org/e107files/downloads/guidelinesburncare.pdf Barajas-Nava LA, LÃ³pez-Alcalde J, RoquÃ© i Figuls M, SolÃ I, Bonfill Cosp X. Antibiotic prophylaxis for preventing burn wound infection. Cochrane Database of Systematic Reviews 2013, Issue 6. Art. No.: CD008738. DOI: 10.1002/14651858.CD008738.pub2. Hettiaratchy S & Papini R. Initial management of a major burn: assessment and resuscitation. BMJ 2004;329:101-103

Answer 1413

The tibial nerve is closely related to the posterior tibial artery. The tibial nerve crosses the vessel posteriorly approximately 2.5cm distal to its origin. At its origin the nerve lies medial and then lateral after it crosses the vessel as described. Posterior tibial artery Larger terminal branch of the popliteal artery Terminates by dividing into the medial and lateral plantar arteries Accompanied by two veins throughout its length Position of the artery corresponds to a line drawn from the lower angle of the popliteal fossa, at the level of the neck of the fibula, to a point midway between the medial malleolus and the most prominent part of the heel Relations of the posterior tibial artery Proximal to distal Anteriorly Tibialis posterior Flexor digitorum longus Posterior surface of tibia and ankle joint Posterior Tibial nerve 2.5 cm distal to its origin Fascia overlying the deep muscular layer Proximal part covered by gastrocnemius and soleus Distal part covered by skin and fascia

Answer 1414

Ray amputations for diabetic foot infections do not heal well and should never be primarily closed. The use of vacuum assisted closure devices has been shown to improve healing rates. Methods of wound closure Method of closure Indication Primary closure Clean wound, usually surgically created or following minor trauma Standard suturing methods will usually suffice Wound heals by primary intention Delayed primary closure Similar methods of actual closure to primary closure May be used in situations where primary closure is either not achievable or not advisable e.g. infection Vacuum assisted closure Uses negative pressure therapy to facilitate wound closure Sponge is inserted into wound cavity and then negative pressure applied Advantages include removal of exudate and versatility Disadvantages include cost and risk of fistulation if used incorrectly on sites such as bowel Split thickness skin grafts Superficial dermis removed with Watson knife or dermatome (commonly from thigh) Remaining epithelium regenerates from dermal appendages Coverage may be increased by meshing Full thickness skin grafts Whole dermal thickness is removed Sub dermal fat is then removed and graft placed over donor site Better cosmesis and flexibility at recipient site Donor site morbidity Flaps Viable tissue with a blood supply May be pedicled or free Pedicled flaps are more reliable, but limited in range Free flaps have greater range but carry greater risk of breakdown as they require vascular anastomosis

Answer 1415

The kidney autoregulates its blood supply over a range of systolic blood pressures. Drop in arterial pressure is sensed by the juxtaglomerular cells and renin is released leading to the activation of the renin-angiontensin system. Mesangial cells are contractile cells that are located in the tubule and have no direct endocrine function. Renal Physiology Overview Each nephron is supplied with blood from an afferent arteriole that opens onto the glomerular capillary bed. Blood then flows to an efferent arteriole, supplying the peritubular capillaries and medullary vasa recta. The kidney receives up to 25% of resting cardiac output. Control of blood flow The kidney is able to autoregulate its blood flow between systolic pressures of 80- 180mmHg so there is little variation in renal blood flow. This is achieved by myogenic control of arteriolar tone, both sympathetic input and hormonal signals (e.g. renin) are responsible. Glomerular structure and function Blood inside the glomerulus has considerable hydrostatic pressure. The basement membrane has pores that will allow free diffusion of smaller solutes, larger negatively charged molecules such as albumin are unable to cross. The glomerular filtration rate (GFR) is equal to the concentration of a solute in the urine, times the volume of urine produced per minute, divided by the plasma concentration (assuming that the solute is freely diffused e.g. inulin). In clinical practice creatinine is used because it is subjected to very little proximal tubular secretion. Although subject to variability, the typical GFR is 125ml per minute. Glomerular filtration rate = Total volume of plasma per unit time leaving the capillaries and entering the bowman's capsule Renal clearance = volume plasma from which a substance is removed per minute by the kidneys Substances used to measure GFR have the following features: 1. Inert 2. Free filtration from the plasma at the glomerulus (not protein bound) 3. Not absorbed or secreted at the tubules 4. Plasma concentration constant during urine collection Examples: inulin, creatinine GFR = urine concentration (mmol/l) x urine volume (ml/min) -------------------------------------------------------------------------- plasma concentration (mmol/l) The clearance of a substance is dependent not only on its diffusivity across the basement membrane but also subsequent tubular secretion and / or reabsorption. So glucose which is freely filtered across the basement membrane is usually reabsorbed from tubules giving a clearance of zero. Tubular function Reabsorption and secretion of substances occurs in the tubules. In the proximal tubule substrates such as glucose, amino acids and phosphate are co-transported with sodium across the semi permeable membrane. Glucose is reabsorbed by both active and passive processes. The former uses sodiumâ€“glucose co-transporters (SGLTs) in the proximal convoluted tubule. The latter achieved through facilitated and passive process through GLUT transporters. Up to two thirds of filtered water is reabsorbed in the proximal tubules. This will lead to increase in urea concentration in the distal tubule allowing for its increased diffusion. Substances to be secreted into the tubules are taken up from the peritubular blood by tubular cells. Solutes such as paraaminohippuric acid are cleared with a single passage through the kidneys and this is why it is used to measure renal plasma flow. Ions such as calcium and phosphate will have a tubular reabsorption that is influenced by plasma PTH levels. Potassium may be both secreted and re-absorbed and is co-exchanged with sodium. Loop of Henle Approximately 60 litres of water containing 9000mmol sodium enters the descending limb of the loop of Henle in 24 hours. Loops from the juxtamedullary nephrons run deep into the medulla. The osmolarity of fluid changes and is greatest at the tip of the papilla. The thick ascending limb is impermeable to water, but highly permeable to sodium and chloride ions. This loss means that at the beginning of the thick ascending limb the fluid is hypo osmotic compared with adjacent interstitial fluid. In the thick ascending limb the reabsorption of sodium and chloride ions occurs by both facilitated and passive diffusion pathways. The loops of Henle are co-located with vasa recta, these will have similar solute compositions to the surrounding extracellular fluid so preventing the diffusion and subsequent removal of this hypertonic fluid. The energy dependent reabsorption of sodium and chloride in the thick ascending limb helps to maintain this osmotic gradient.

Answer 1416

In Catterall stage I disease there may be no radiological abnormality at all. In Stage II disease there may be sclerosis of the femoral head. Indication for treatment (aide memoire):Half a dozen, half a head Those aged greater than 6 years with >50% involvement of the femoral head should almost always be treated. Perthes disease Perthes disease Idiopathic avascular necrosis of the femoral epiphysis of the femoral head Impaired blood supply to femoral head, causing bone infarction. New vessels develop and ossification occurs. The bone either heals or a subchondral fracture occurs. Clinical features Males 4x's greater than females Age between 2-12 years (the younger the age of onset, the better the prognosis) Limp Hip pain Bilateral in 20% Diagnosis Plain x-ray, Technetium bone scan or magnetic resonance imaging if normal x-ray and symptoms persist. Catterall staging Stage Features Stage 1 Clinical and histological features only Stage 2 Sclerosis with or without cystic changes and preservation of the articular surface Stage 3 Loss of structural integrity of the femoral head Stage 4 Loss of acetabular integrity Management To keep the femoral head within the acetabulum: cast, braces If less than 6 years: observation Older: surgical management with moderate results Operate on severe deformities Prognosis Most cases will resolve with conservative management. Early diagnosis improves outcomes.

Answer 1417

The external oblique will be encountered first in this location. The rectus sheath lies more medially. The external oblique muscle is the most superficial of the abdominal wall muscles. It originates from the 5th to 12th ribs and passes inferomedially to insert into the linea alba, pubic tubercle and anterior half of the iliac crest. It is innervated by the thoracoabdominal nerves (T7-T11) and sub costal nerves. Abdominal wall The 2 main muscles of the abdominal wall are the rectus abdominis (anterior) and the quadratus lumborum (posterior). The remaining abdominal wall consists of 3 muscular layers. Each muscle passes from the lateral aspect of the quadratus lumborum posteriorly to the lateral margin of the rectus sheath anteriorly. Each layer is muscular posterolaterally and aponeurotic anteriorly. Muscles of abdominal wall External oblique Lies most superficially Originates from 5th to 12th ribs Inserts into the anterior half of the outer aspect of the iliac crest, linea alba and pubic tubercle More medially and superiorly to the arcuate line, the aponeurotic layer overlaps the rectus abdominis muscle The lower border forms the inguinal ligament The triangular expansion of the medial end of the inguinal ligament is the lacunar ligament. Internal oblique Arises from the thoracolumbar fascia, the anterior 2/3 of the iliac crest and the lateral 2/3 of the inguinal ligament The muscle sweeps upwards to insert into the cartilages of the lower 3 ribs The lower fibres form an aponeurosis that runs from the tenth costal cartilage to the body of the pubis At its lowermost aspect it joins the fibres of the aponeurosis of transversus abdominis to form the conjoint tendon. Transversus abdominis Innermost muscle Arises from the inner aspect of the costal cartilages of the lower 6 ribs , from the anterior 2/3 of the iliac crest and lateral 1/3 of the inguinal ligament Its fibres run horizontally around the abdominal wall ending in an aponeurosis. The upper part runs posterior to the rectus abdominis. Lower down the fibres run anteriorly only. The rectus abdominis lies medially; running from the pubic crest and symphysis to insert into the xiphoid process and 5th, 6th and 7th costal cartilages. The muscles lies in a aponeurosis as described above. Nerve supply: anterior primary rami of T7-12 Surgical notes During abdominal surgery it is usually necessary to divide either the muscles or their aponeuroses. During a midline laparotomy it is desirable to divide the aponeurosis. This will leave the rectus sheath intact above the arcuate line and the muscles intact below it. Straying off the midline will often lead to damage to the rectus muscles, particularly below the arcuate line where they may often be in close proximity to each other.

Answer 1418

Up to 10% of all patients may have stones in the CBD. Therefore, all patients should have their liver function tests checked prior to embarking on a cholecystectomy. Biliary disease Diagnosis Typical features Pathogenesis Gallstones Typically history of biliary colic or episodes of chlolecystitis. Obstructive type history and test results. Usually small calibre gallstones which can pass through the cystic duct. In Mirizzi syndrome the stone may compress the bile duct directly- one of the rare times that cholecystitis may present with jaundice Cholangitis Usually obstructive and will have Charcot's triad of symptoms (pain, fever, jaundice) Ascending infection of the bile ducts usually by E. coli and by definition occurring in a pool of stagnant bile. Pancreatic cancer Typically painless jaundice with palpable gallbladder (Courvoisier's Law) Direct occlusion of distal bile duct or pancreatic duct by tumour. Sometimes nodal disease at the portal hepatis may be the culprit in which case the bile duct may be of normal calibre. TPN (total parenteral nutrition) associated jaundice Usually follows long term use and is usually painless with non obstructive features Often due to hepatic dysfunction and fatty liver which may occur with long term TPN usage. Bile duct injury Depending upon the type of injury may be of sudden or gradual onset and is usually of obstructive type Often due to a difficult laparoscopicÂ cholecystectomy when anatomy in Calots triangle is not appreciated. In the worst scenario the bile duct is excised and jaundice develops rapidly post operatively. More insidious is that of bile duct stenosis which may be caused by clips or diathermy injury. Cholangiocarcinoma Gradual onset obstructive pattern Direct occlusion by disease and also extrinsic compression by nodal disease at the porta hepatis. Septic surgical patient Usually hepatic features Combination of impaired biliary excretion and drugs such as ciprofloxacin which may cause cholestasis. Metastatic disease Mixed hepatic and post hepatic Combination of liver synthetic failure (late) and extrinsic compression by nodal disease and anatomical compression of intra hepatic structures (earlier) A gallbladder may develop a thickened wall in chronic cholecystitis, microscopically Roikitansky-Aschoff Sinuses may be seen

Answer 1419

Electrical burn infusion protocols are different to those for flame or scald burns as higher volumes of fluid are given with increased targets for urine output to minimize the effects of rhabdomyolysis. Fluid resuscitation burns Indication: >15% total body area burns in adults (>10% children) The main aim of resuscitation is to prevent the burn deepening Most fluid is lost 24 hours after injury First 8-12 hour fluid shifts are from intravascular to interstitial fluid compartments Therefore circulatory volume can be compromised. However fluid resuscitation causes more fluid into the interstitial compartment especially colloid (therefore avoided in first 8-24 hours) Protein loss occurs There are concerns that use of the traditional Parkland formula resulted in the administration of excessive quantities of intravenous fluids in patients with burns. The current consensus guidelines state that fluid resuscitation should begin at 2 ml of lactated Ringers x patients body weight in kg x % TBSA for second- and third-degree burns. The calculated fluid volume is initiated in the following manner: one-half of the total fluid is provided in the first 8 hours after the burn injury (for example, a 100-kg man with 80% TBSA burns requires 2 Ã— 80 Ã— 100 = 16,000 mL in 24 hours). One-half of that volume (8,000 mL) should be provided in the first 8 hours, so the patient should be started at a rate of 1000 mL/hr. The remaining one-half of the total fluid is administered during the subsequent 16 hours. The efficacy of fluid replacement is determined in the main by monitoring urine output. For adults this is in the region of 0.5ml/kg/hr and for children less than 30Kg it is 1ml/kg/hr. Fluid resuscitation according to burn type Type of burn Age or weight Fluid rate Urine output Flames or scalding Adults and children over 14 years 2 ml Hartmanns x kg x % TBSA 0.3-0.5ml/kg/hr OR 30-50ml per hour Flames or scalding Children less than 14 years 3 ml Hartmanns x kg x % TBSA 1ml/kg/hr Flames or scalds Children less than 30Kg and infants 3 ml Hartmanns x kg x % TBSA. Plus a sugar-containing solution at maintenance rate 1ml/kg/hr Electrical injury All ages 4 ml Hartmanns x kg x % TBSA until urine clears 1-1.5 ml/kg/hr until urine clears Fluid resuscitation in electrical burn patients is different because they have far greater soft tissue involvement in muscle compartments and associated muscle death that can result in myoglobinuria. After 24 hours Maintenance crystalloid (usually dextrose-saline) is continued at a rate of 1.5 ml x(burn area)x(body weight) Colloids are rarely used (e.g. albumin) Antioxidants, such as vitamin C, can be used to minimize oxidant-mediated contributions to the inflammatory cascade in burns High tension electrical injuries and inhalation injuries require more fluid Monitor: packed cell volume, plasma sodium, base excess, and lactate Reference ATLS Manual 10th Edition.

Answer 1420

At the 3rd month the foetus's spinal cord occupies the entire length of the vertebral canal. The vertebral column then grows longer exceeding the growth rate of the spinal cord. This results with the cord being at L3 at birth and L1-2 by adulthood. Spinal cord - Located in a canal within the vertebral column that affords it structural support. Rostrally it continues to the medulla oblongata of the brain and caudally it tapers at a level corresponding to the L1-2 interspace (in the adult), a central structure, the filum terminale anchors the cord to the first coccygeal vertebra. The spinal cord is characterised by cervico-lumbar enlargements and these, broadly speaking, are the sites which correspond to the brachial and lumbar plexuses respectively. There are some key points to note when considering the surgical anatomy of the spinal cord: * During foetal growth the spinal cord becomes shorter than the spinal canal, hence the adult site of cord termination at the L1-2 level. * Due to growth of the vertebral column the spine segmental levels may not always correspond to bony landmarks as they do in the cervical spine. * The spinal cord is incompletely divided into two symmetrical halves by a dorsal median sulcus and ventral median fissure. Grey matter surrounds a central canal that is continuous rostrally with the ventricular system of the CNS. * The grey matter is sub divided cytoarchitecturally into Rexeds laminae. * Afferent fibres entering through the dorsal roots usually terminate near their point of entry but may travel for varying distances in Lissauers tract. In this way they may establish synaptic connections over several levels * At the tip of the dorsal horn are afferents associated with nociceptive stimuli. The ventral horn contains neurones that innervate skeletal muscle. The key point to remember when revising CNS anatomy is to keep a clinical perspective in mind. So it is worth classifying the ways in which the spinal cord may become injured. These include: Trauma either direct or as a result of disc protrusion Neoplasia either by direct invasion (rare) or as a result of pathological vertebral fracture Inflammatory diseases such as Rheumatoid disease, or OA (formation of osteophytes compressing nerve roots etc. Vascular either as a result of stroke (rare in cord) or as complication of aortic dissection Infection historically diseases such as TB, epidural abscesses. The anatomy of the cord will, to an extent dictate the clinical presentation. Some points/ conditions to remember: Brown- Sequard syndrome-Hemisection of the cord producing ipsilateral loss of proprioception and upper motor neurone signs, plus contralateral loss of pain and temperature sensation. The explanation of this is that the fibres decussate at different levels. Lesions below L1 will tend to present with lower motor neurone signs

Answer 1421

Mobilising the spleen will result in removal. Splenic injuries like this are amenable to conservation. Splenic trauma - The spleen is one of the more commonly injured intra abdominal organs In most cases the spleen can be conserved. The management is dictated by the associated injuries, haemodynamic status and extent of direct splenic injury. Management of splenic trauma Conservative Small subcapsular haematoma Minimal intra abdominal blood No hilar disruption Laparotomy with conservation Increased amounts of intraabdominal blood Moderate haemodynamic compromise Tears or lacerations affecting <50% Resection Hilar injuries Major haemorrhage Major associated injuries Splenectomy Technique Trauma GA Long midline incision If time permits insert a self retaining retractor (e.g. Balfour/ omnitract) Large amount of free blood is usually present. Pack all 4 quadrants of the abdomen. Allow the anaesthetist to 'catch up' Remove the packs and assess the viability of the spleen. Hilar injuries and extensive parenchymal lacerations will usually require splenectomy. Divide the short gastric vessels and ligate them. Clamp the splenic artery and vein. Two clamps on the patient side are better and allow for double ligation and serve as a safety net if your assistant does not release the clamp smoothly. Be careful not to damage the tail of the pancreas, if you do then this will need to be formally removed and the pancreatic duct closed. Wash out the abdomen and place a tube drain to the splenic bed. Some surgeons implant a portion of spleen into the omentum, whether you decide to do this is a matter of personal choice. Post operatively the patient will require prophylactic penicillin V and pneumococcal vaccine. Elective Elective splenectomy is a very different operation from that performed in the emergency setting. The spleen is often large (sometimes massive). Most cases can be performed laparoscopically. The spleen will often be macerated inside a specimen bag to facilitate extraction. Complications Haemorrhage (may be early and either from short gastrics or splenic hilar vessels Pancreatic fistula (from iatrogenic damage to pancreatic tail) Thrombocytosis: prophylactic aspirin Encapsulated bacteria infection e.g. Strep. pneumoniae, Haemophilus influenzae and Neisseria meningitidis

Answer 1422

Treatment with systemic antibiotics may result in development of candidiasis. Patients may present with odynophagia and episodic dysphagia. Endoscopic appearances are usually diagnostic and treatment is with an oral anti fungal agent. Dysphagia Causes of dysphagia Extrinsic Mediastinal masses Cervical spondylosis Oesophageal wall Achalasia Diffuse oesophageal spasm Hypertensive lower oesophageal sphincter Intrinsic Tumours Strictures Oesophageal web Schatzki rings Neurological CVA Parkinson's disease Multiple Sclerosis Brainstem pathology Myasthenia Gravis Investigation All patients require an upper GI endoscopy unless there are compelling reasons for this not to be performed. Motility disorders may be best appreciated by undertaking fluoroscopic swallowing studies. A full blood count should be performed. Ambulatory oesophageal pH and manometry studies will be required to evaluate conditions such as achalasia and patients with GORD being considered for fundoplication surgery.

Answer 1423

Only the IMA is likely to affect the left side of the colon and originate at L3. Inferior mesenteric artery The IMA is the main arterial supply of the embryonic hindgut and originates approximately 3-4 cm superior to the aortic bifurcation. From its aortic origin it passes immediately inferiorly across the anterior aspect of the aorta to eventually lie on its left hand side. At the level of the left common iliac artery it becomes the superior rectal artery. Branches The left colic artery arises from the IMA near its origin. More distally up to three sigmoid arteries will exit the IMA to supply the sigmoid colon.

Answer 1424

First time renal tranplants are typically implanted in the left or right iliac fossae. The vessels are usually joined to the external iliac artery and vein as these are the most easily accessible. The Rutherford Morison incision provides access to the external iliac vessels. Organ Transplant A number of different organ and tissue transplants are now available. In many cases an allograft is performed, where an organ is transplanted from one individual to another. Allografts will elicit an immune response and this is one of the main reasons for organ rejection. Graft rejection occurs because allografts have allelic differences at genes that code immunohistocompatability complex genes. The main antigens that give rise to rejection are: ABO blood group Human leucocyte antigens (HLA) Minor histocompatability antigens ABO Matching ABO incompatibility will result in early organ rejection (hyperacute) because of pre existing antibodies to other groups. Group O donors can give organs to any type of ABO recipient whereas group AB donor can only donate to AB recipient. HLA System The four most important HLA alleles are: HLA A HLA B HLA C HLA DR An ideal organ match would be one in which all 8 alleles are matched (remember 2 from each parent, four each = 8 alleles). Modern immunosuppressive regimes help to manage the potential rejection due to HLA mismatching. However, the greater the number of mismatches the worse the long term outcome will be. T lymphocytes will recognise antigens bound to HLA molecules and will then become activated. Clonal expansion then occurs with a response directed against that antigen. Types of organ rejection Hyperacute. This occurs immediately through presence of pre formed antibodies (such as ABO incompatibility). Acute. Occurs during the first 6 months and is usually T cell mediated. Usually tissue infiltrates and vascular lesions. Chronic. Occurs after the first 6 months. Vascular changes predominate. Hyperacute Renal transplants at greatest risk and liver transplants at least risk. Although ABO incompatibility and HLA Class I incompatible transplants will all fare worse in long term. Acute All organs may undergo acute rejection. Mononuclear cell infiltrates predominate. All types of transplanted organ are susceptible and it may occur in up to 50% cases. Chronic Again all transplants with HLA mismatch may suffer this fate. Previous acute rejections and other immunosensitising events all increase the risk. Vascular changes are most prominent with myointimal proliferation leading to organ ischaemia. Organ specific changes are also seen such as loss of acinar cells in pancreas transplants and rapidly progressive coronary artery disease in cardiac transplants. Surgical overview-Renal transplantation A brief overview of the steps involved in renal transplantation is given. Patients with end stage renal failure who are dialysis dependent or likely to become so in the immediate future are considered for transplant. Exclusion criteria include; active malignancy, old age (due to limited organ availability). Patients are medically optimised. Donor kidneys, these may be taken from live related donors and close family, members may have less HLA mismatch than members of the general population. Laparoscopic donor nephrectomy further minimises the operative morbidity for the donor. Other organs are typically taken from brain dead or dying patients who have a cardiac arrest and in whom resuscitation is futile. The key event is to minimise the warm ischaemic time in the donor phase. The kidney once removed is usually prepared on the bench in theatre by the transplant surgeon immediately prior to implantation and factors such as accessory renal arteries and vessel length are assessed and managed. For first time recipients the operation is performed under general anaesthesia. A Rutherford-Morison incision is made on the preferred side. This provides excellent extraperitoneal access to the iliac vessels. The external iliac artery and vein are dissected out and following systemic heparinisation are cross clamped. The vein and artery are anastamosed to the iliacs and the clamps removed. The ureter is then implanted into the bladder and a stent is usually placed to maintain patency. The wounds are then closed and the patient recovered from surgery. In the immediate phase a common problem encountered in cadaveric kidneys is acute tubular necrosis and this tends to resolve. Graft survival times from cadaveric donors are typically of the order of 9 years and monozygotic twin transplant (live donor) may survive as long as 25 years.

Answer 1425

Mnemonic for transfusion reactions: Got a bad unit G raft vs. Host disease O verload T hrombocytopaenia A lloimmunization B lood pressure unstable A cute haemolytic reaction D elayed haemolytic reaction U rticaria N eutrophilia I nfection T ransfusion associated lung injury The diagnosis is of an acute haemolytic transfusion reaction, normally due to ABO incompatibility. Haemolysis of the transfused cells occurs causing the combination of shock, haemoglobinaemia and loin pain. This may subsequently lead to disseminated intravascular coagulation. A Coomb's test should confirm haemolysis. Other tests for haemolysis include: unconjugated bilirubin, haptoglobin, serum and urine free haemoglobin. Note that delayed haemolytic reactions are normally associated with antibodies to the Rh system and occur 5-10 days after transfusion. Blood transfusion reactions Acute transfusion reactions present as adverse signs or symptoms during or within 24 hours of a blood transfusion. The most frequent reactions are fever, chills, pruritus, or urticaria, which typically resolve promptly without specific treatment or complications. Other signs occurring in temporal relationship with a blood transfusion, such as severe dyspnoea, pyrexia, or loss of consciousness may be the first indication of a more severe potentially fatal reaction. The causes of adverse reactions are multi-factorial. Immune mediated reactions, some of the most feared, occur as a result of component mismatch, the commonest cause of which is clerical error. More common, non immune mediated, complications may occur as a result of product contamination, this may be bacterial or viral. Transfusion related lung injury is well recognised and there are two proposed mechanisms which underpin this. One involves the sequestration of primed neutrophils within the recipient pulmonary capillary bed. The other proposed mechanism suggests that HLA mismatches between donor neutrophils and recipient lung tissue is to blame. The table below summarises the main types of transfusion reaction. Immune mediated Non immune mediated Pyrexia Hypocalcaemia Alloimmunization CCF Thrombocytopaenia Infections Transfusion associated lung injury Hyperkalaemia Graft vs Host disease Urticaria Acute or delayed haemolysis ABO incompatibility Rhesus incompatibility

Answer 1426

Anal fissures are associated with: Sexually transmitted diseases (syphilis, HIV) Inflammatory bowel disease (Crohn's up to 50%) Leukaemia (25% of patients) Tuberculosis Previous anal surgery Ano rectal disease Haemorrhoids Location: 3, 7, 11 o'clock position Internal or external Treatment: Conservative, Rubber band ligation, Haemorrhoidectomy Fissure in ano Location: midline 6 (posterior midline 90%) and 12 o'clock position. Distal to the dentate line Chronic fissure > 6/52: triad: Ulcer, sentinel pile, enlarged anal papillae Proctitis Causes: Crohn's, ulcerative colitis, Clostridium difficile Ano rectal abscess E.coli, staph aureus Positions: Perianal, Ischiorectal, Pelvirectal, Intersphincteric Anal fistula Usually due to previous ano-rectal abscess Intersphincteric, transsphincteric, suprasphincteric, and extrasphincteric. Goodsalls rule determines location Rectal prolapse Associated with childbirth and rectal intussceception. May be internal or external Pruritus ani Systemic and local causes Anal neoplasm Squamous cell carcinoma commonest unlike adenocarcinoma in rectum Solitary rectal ulcer Associated with chronic straining and constipation. Histology shows mucosal thickening, lamina propria replaced with collagen and smooth muscle (fibromuscular obliteration) Rectal prolapse Common especially in multiparous women. May be internal or external. Internal rectal prolapse can present insidiously. External prolapse can ulcerate and in long term impair continence. Diagnostic work up includes colonoscopy, defecating proctogram, ano rectal manometry studies and if doubt exists an examination under anaesthesia. Treatments for prolapse In the acute setting reduce it (covering it with sugar may reduce swelling. Delormes procedure which excises mucosa and plicates the rectum (high recurrence rates) may be used for external prolapse. Altmeirs procedure which resects the colon via the perineal route has lower recurrence rates but carries the risk of anastamotic leak. Rectopexy is an abdominal procedure in which the rectum is elevated and usually supported at the level of the sacral promontory. Post operative constipation may be reduced by limiting the dissection to the anterior plane (laparoscopic ventral mesh rectopexy). Pruritus ani Extremely common. Check not secondary to altered bowel habits (e.g. Diarrhoea) Associated with underlying diseases such as haemorrhoids. Examine to look for causes such as worms. Proctosigmoidoscopy to identify associated haemorrhoids and exclude cancer. Treatment is largely supportive and patients should avoid using perfumed products around the area. Fissure in ano Typically painful PR bleeding (bright red). Nearly always in the posterior midline. Usually solitary. Treatment Stool softeners. Topical diltiazem (or GTN). If topical treatments fail then botulinum toxin should be injected. If botulinum toxin fails then males should probably undergo lateral internal sphincterotomy. Females who do not respond to botulinum toxin should undergo ano rectal manometry studies and endo anal USS prior to being offered surgery such as sphincterotomy.

Answer 1427

Pseudocysts are unlikely to be present less than 4 weeks after an attack of acute pancreatitis. However, they are more common at this stage and are associated with a raised amylase. Pancreatitis: sequelae Peripancreatic fluid collections Occur in 25% cases Located in or near the pancreas and lack a wall of granulation or fibrous tissue May resolve or develop into pseudocysts or abscesses Since most resolve aspiration and drainage is best avoided as it may precipitate infection Pseudocysts In acute pancreatitis result from organisation of peripancreatic fluid collection. They may or may not communicate with the ductal system. The collection is walled by fibrous or granulation tissue and typically occurs 4 weeks or more after an attack of acute pancreatitis Most are retrogastric 75% are associated with persistent mild elevation of amylase Investigation is with CT, ERCP and MRI or Endoscopic USS Symptomatic cases may be observed for 12 weeks as up to 50% resolve Treatment is either with endoscopic or surgical cystogastrostomy or aspiration Pancreatic necrosis Pancreatic necrosis may involve both the pancreatic parenchyma and surrounding fat Complications are directly linked to extent of parenchymal necrosis and extent of necrosis overall Early necrosectomy is associated with a high mortality rate (and should be avoided unless compelling indications for surgery exist) Sterile necrosis should be managed conservatively (at least initially) Some centres will perform fine needle aspiration sampling of necrotic tissue if infection is suspected. False negatives may occur. The extent of sepsis and organ dysfunction may be a better guide to surgery Pancreatic abscess Intra abdominal collection of pus associated with pancreas but in the absence of necrosis Typically occur as a result of infected pseudocyst They are usually managed by placement of percutaneous drains Haemorrhage Infected necrosis may involve vascular structures with resultant haemorrhage that may occur de novo or as a result of surgical necrosectomy. When retroperitoneal haemorrhage occurs Grey Turners sign may be identified

Answer 1428

The finding of a scaphoid abdomen and respiratory distress suggests extensive intra thoracic herniation of the abdominal contents. This is seen most frequently with Bochdalek hernias. Morgagni hernias seldom present in such a dramatic fashion. The other options do not typically present with the symptoms and signs described. Embryology of the diaphragm and diaphragmatic hernia Embryology The diaphragm is formed between the 5th and 7th weeks of gestation through the progressive fusion of the septum transversum, pleuroperitoneal folds and via lateral muscular ingrowth. The muscular origins of the diaphragm are somites located in cervical segments 3 to 5, which accounts for the long path taken by the phrenic nerve. The components contribute to the following diaphragmatic segments: Septum transversum - Central tendon Pleuroperitoneal membranes - Parietal membranes surrounding viscera Cervical somites C3 to C5 - Muscular component of the diaphragm Diaphragmatic hernia Type of hernia Features Morgagni Anteriorly located Minimal compromise on lung development Minimal signs on antenatal ultrasound Usually present later Usually good prognosis Bochdalek hernia Posteriorly located Larger defect Often diagnosed antenatally Associated with pulmonary hypoplasia Poor prognosis The posterior hernias of Bochdalek are the most common type and if not diagnosed antenatally will typically present soon after birth with respiratory distress. The classical finding is that of a scaphoid abdomen on clinical examination because of herniation of the abdominal contents into the chest. Bochdalek hernias are associated with a number of chromosomal abnormalities such as Trisomy 21 and 18. Infants have considerable respiratory distress due to hypoplasia of the developing lung. Historically this was considered to be due to direct compression of the lung by herniated viscera. This view over simplifies the situation and the pulmonary hypoplasia occurs concomitantly with the hernial development, rather than as a direct result of it. The pulmonary hypoplasia is associated with pulmonary hypertension and abnormalities of pulmonary vasculature. The pulmonary hypertension renders infants at risk of right to left shunting (resulting in progressive and worsening hypoxia). Diagnostic work up of these infants includes chest x-rays/ abdominal ultrasound scans and cardiac echo. Surgery forms the mainstay of treatment and both thoracic and abdominal approaches may be utilised. Following reduction of the hernial contents a careful search needs to be made for a hernial sac as failure to recognise and correct this will result in a high recurrence rate. Smaller defects may be primarily closed, larger defects may require a patch to close the defect. Malrotation of the viscera is a recognised association and may require surgical correction at the same procedure (favoring an abdominal approach). The mortality rate is 50-75% and is related to the degree of lung compromise and age at presentation (considerably better in infants >24 hours old).

Answer 1429

Potassium depletion occurs either through the gastrointestinal tract or the kidney. Chronic vomiting in itself is less prone to induce potassium loss than diarrhoea as gastric secretions contain less potassium than those in the lower GI tract. If vomiting produces a metabolic alkalosis then renal potassium wasting may occur as potassium is excreted in preference to hydrogen ions. The converse may occur in potassium depletion resulting in acid urine. Hypokalemia is very commonly associated with metabolic alkalosis. This is due to 2 factors: 1) the common causes of metabolic alkalosis (vomiting, diuretics) directly induce H+ and K loss (via aldosterone) and thus also cause hypokalemia and 2) hypokalemia is a very important cause of metabolic alkalosis by three mechanisms. The initial effect is by causing a transcellular shift in which K leaves and H+ enters the cells, thereby raising the extracellular pH. The second effect is by causing a transcellular shift in the cells of the proximal tubules resulting in an intracellular acidosis, which promotes ammonium production and excretion. Thirdly, in the presence of hypokalemia, hydrogen secretion in the proximal and distal tubules increases. This leads to further reabsorption of HCO3-. The net effect is an increase in the net acid excretion. Hypokalaemia Potassium and hydrogen can be thought of as competitors. Hyperkalaemia tends to be associated with acidosis because as potassium levels rise fewer hydrogen ions can enter the cells Hypokalaemia with alkalosis Vomiting Diuretics Cushing's syndrome Conn's syndrome (primary hyperaldosteronism) Hypokalaemia with acidosis Diarrhoea Renal tubular acidosis Acetazolamide Partially treated diabetic ketoacidosis

Answer 1430

The basilic vein drains into the axillary vein and although PICC lines may end up in a variety of fascinating locations the axillary vein is usually the commonest site following from the basilic. The posterior circumflex humeral vein is encountered prior to the axillary vein. However, a PICC line is unlikely to enter this structure because of its angle of entry into the basilic vein. Basilic vein The basilic and cephalic veins both provide the main pathways of venous drainage for the arm and hand. It is continuous with the palmar venous arch distally and the axillary vein proximally. Path Originates on the medial side of the dorsal venous network of the hand, and passes up the forearm and arm. Most of its course is superficial. Near the region anterior to the cubital fossa the vein joins the cephalic vein. Midway up the humerus the basilic vein passes deep under the muscles. At the lower border of the teres major muscle, the anterior and posterior circumflex humeral veins feed into it. It is often joined by the medial brachial vein before draining into the axillary vein.

Answer 1431

This area is most dangerous as infections can spread easily. The emissary veins that drain this area may allow sepsis to spread to the cranial cavity. Head injury Patients who suffer head injuries should be managed according to ATLS principles and extra cranial injuries should be managed alongside cranial trauma. Inadequate cardiac output will compromise CNS perfusion irrespective of the nature of the cranial injury. Types of traumatic brain injury Extradural haematoma Bleeding into the space between the dura mater and the skull. Often results from acceleration-deceleration trauma or a blow to the side of the head. The majority of extradural haematomas occur in the temporal region where skull fractures cause a rupture of the middle meningeal artery. Features Raised intracranial pressure Some patients may exhibit a lucid interval Subdural haematoma Bleeding into the outermost meningeal layer. Most commonly occur around the frontal and parietal lobes. May be either acute or chronic. Risk factors include old age and alcoholism. Slower onset of symptoms than a extradural haematoma. Subarachnoid haemorrhage Usually occurs spontaneously in the context of a ruptured cerebral aneurysm, but may be seen in association with other injuries when a patient has sustained a traumatic brain injury. Pathophysiology Primary brain injury may be focal (contusion/ haematoma) or diffuse (diffuse axonal injury) Diffuse axonal injury occurs as a result of mechanical shearing following deceleration, causing disruption and tearing of axons Intra-cranial haematomas can be extradural, subdural or intracerebral, while contusions may occur adjacent to (coup) or contralateral (contre-coup) to the side of impact Secondary brain injury occurs when cerebral oedema, ischaemia, infection, tonsillar or tentorial herniation exacerbates the original injury. The normal cerebral auto regulatory processes are disrupted following trauma rendering the brain more susceptible to blood flow changes and hypoxia The Cushings reflex (hypertension and bradycardia) often occurs late and is usually a pre terminal event Management Where there is life threatening rising ICP such as in extra dural haematoma and whilst theatre is prepared or transfer arranged use of IV mannitol/ frusemide may be required. Diffuse cerebral oedema may require decompressive craniotomy Exploratory Burr Holes have little management in modern practice except where scanning may be unavailable and to thus facilitate creation of formal craniotomy flap Depressed skull fractures that are open require formal surgical reduction and debridement, closed injuries may be managed non operatively if there is minimal displacement. ICP monitoring is appropriate in those who have GCS 3-8 and normal CT scan. ICP monitoring is mandatory in those who have GCS 3-8 and abnormal CT scan. Hyponatraemia is most likely to be due to syndrome of inappropriate ADH secretion. Minimum of cerebral perfusion pressure of 70mmHg in adults. Minimum cerebral perfusion pressure of between 40 and 70 mmHg in children. Interpretation of pupillary findings in head injuries Pupil size Light response Interpretation Unilaterally dilated Sluggish or fixed 3rd nerve compression secondary to tentorial herniation Bilaterally dilated Sluggish or fixed Poor CNS perfusion Bilateral 3rd nerve palsy Unilaterally dilated or equal Cross reactive (Marcus - Gunn) Optic nerve injury Bilaterally constricted May be difficult to assess Opiates Pontine lesions Metabolic encephalopathy Unilaterally constricted Preserved Sympathetic pathway disruption

Answer 1432

This is a knowledge application question. Fresh blood in the small bowel of a child/ adolescent with normal mucosa is likely to reflect a bleeding Meckels diverticulum. These are not usually seen at endoscopy as they are too proximally sited but the normal mucosa seen tends to exclude Crohns disease. For a Meckels to bleed, it must be lined by ectopic gastric mucosa which is an example of heterotopia. Heterotopia Heterotopia is the presence of a specified normal tissue type at a non-physiological site, but usually co-existing with original tissue in its correct anatomical location. It implies ectopic tissue, in addition to retention of the original tissue type. In neuropathology, for example, gray matter heterotopia is the presence of gray matter within the cerebral white matter or ventricles. Heterotopia within the brain is often divided into three groups: subependymal heterotopia, focal cortical heterotopia and band heterotopia. Another example is a Meckel's diverticulum, which may contain heterotopic gastric or pancreatic tissue. It is the fact that the tissue is itself that distinguishes heterotopia from a malignant process.

Answer 1433

The ilioinguinal nerve may have been entrapped in the mesh causing a neuroma. Ilioinguinal nerve Arises from the first lumbar ventral ramus with the iliohypogastric nerve. It passes inferolaterally through the substance of psoas major and over the anterior surface of quadratus lumborum. It pierces the internal oblique muscle and passes deep to the aponeurosis of the external oblique muscle. It enters the inguinal canal and then passes through the superficial inguinal ring to reach the skin. Branches To supply those muscles of the abdominal wall through which it passes. Skin and fascia over the pubic symphysis, superomedial part of the femoral triangle, surface of the scrotum, root and dorsum of penis or labium majus in females.

Answer 1434

The lesser omentum will need to be divided. During a radical gastrectomy this forms one of the nodal stations that will need to be taken. Coeliac axis The coeliac axis has three main branches. Left gastric Hepatic: branches-Right Gastric, Gastroduodenal, Superior Pancreaticoduodenal, Cystic (occasionally). Splenic: branches- Pancreatic, Short Gastric, Left Gastroepiploic It occasionally gives off one of the inferior phrenic arteries. Relations Anteriorly Lesser omentum Right Right coeliac ganglion and caudate process of liver Left Left coeliac ganglion and gastric cardia Inferiorly Upper border of pancreas and renal vein

Answer 1435

The proximal ureter is supplied by branches from the renal artery. For the other feeding vessels - see below. Ureter 25-35 cm long Muscular tube lined by transitional epithelium Surrounded by thick muscular coat. Becomes 3 muscular layers as it crosses the bony pelvis Retroperitoneal structure overlying transverse processes L2-L5 Lies anterior to bifurcation of iliac vessels Blood supply is segmental; renal artery, aortic branches, gonadal branches, common iliac and internal iliac Lies beneath the uterine artery

Answer 1436

The suspensory muscle of the duodenum which is referred to as the ligament of Treitz is most important. The ligament of Treves is located between the ileum and caecum. Duodenum This is the first and widest part of the small bowel. It has a diameter of around 4-5cm. Its commencement is immediately distal to the pylorus and it runs for around 25cm where it becomes the jejunum at the region of the duodenojejunal flexure. It comprises four parts, superior, descending, horizontal and ascending. Of these, the horizontal is the longest segment. The first 2-3cm of the superior duodenum are intraperitoneal. The remainder is largely retroperitoneal with the exception of the final 1-2cm. Medial relations of the duodenum include the superior pancreatico-duodenal artery and the pancreatic head. The descending duodenum is closely related to the commencement of the transverse colon which has little in the way of mesentery at this area. Posterior to the descending duodenum lies the right kidney. The horizontal part passes transversely to the left with an upward deflection as it does so. From right to left it crosses in front of the right ureter, right psoas major, right gonadal vessels and IVC. It terminates anterior to the aorta. Anteriorly, it's relations include the superior mesenteric vessels and the root of the small bowel. The ascending part runs to the left of the aorta and upwards to the level of L2. It terminates by binding abruptly forwards as the duodenojejunal flexure. Posteriorly, are the left sympathetic trunk, left psoas major and left gonadal vessels. Anteriorly, it gives attachment to the root of the mesentery, while the left kidney lies laterally and the uncinate process of the pancreas lies medially. The region of the duodenojenunal flexure is fixed in position by the suspensory muscle of the duodenum. This fibromuscular band blends with the musculature of the flexure and passes upwards deep to the pancreas to gain attachment to the right crus of the diaphragm. It is referred to eponymously as the ligament of Treitz.

Answer 1437

A Klatskin tumor (or hilar cholangiocarcinoma) is a cholangiocarcinoma (cancer of the biliary tree) occurring at the confluence of the right and left hepatic bile ducts. Liver tumours Primary liver tumours The most common primary tumours are cholangiocarcinoma and hepatocellular carcinoma. Overall metastatic disease accounts for 95% of all liver malignancies making the primary liver tumours comparatively rare. Primary liver tumours include: Cholangiocarcinoma Hepatocellular carcinoma Hepatoblastoma Sarcomas (Rare) Lymphomas Carcinoids (most often secondary although primary may occur) Hepatocellular carcinoma These account for the bulk of primary liver tumours (75% cases). Its worldwide incidence reflects its propensity to occur on a background of chronic inflammatory activity. Most cases arise in cirrhotic livers or those with chronic hepatitis B infection, especially where viral replication is actively occurring. In the UK it accounts for less than 5% of all cancers, although in parts of Asia its incidence is 100 per 100,000. The majority of patients (80%) present with existing liver cirrhosis, with a mass discovered on screening ultrasound. Diagnosis CT/ MRI (usually both) are the imaging modalities of choice a-fetoprotein is elevated in almost all cases Biopsy should be avoided as it seeds tumours cells through a resection plane. In cases of diagnostic doubt serial CT and αFP measurements are the preferred strategy. Treatment Patients should be staged with liver MRI and chest, abdomen and pelvic CT scan. The testis should be examined in males (testicular tumours may cause raised AFP). PET CT may be used to identify occult nodal disease. Surgical resection is the mainstay of treatment in operable cases. In patients with a small primary tumour in a cirrhotic liver whose primary disease process is controlled, consideration may be given to primary whole liver resection and transplantation. Liver resections are an option but since most cases occur in an already diseased liver the operative risks and post-operative hepatic dysfunction are far greater than is seen following metastectomy. These tumours are not particularly chemo or radiosensitive however, both may be used in a palliative setting. Tumour ablation is a more popular strategy. Survival Poor, overall survival is 15% at 5 years. Cholangiocarcinoma This is the second most common type of primary liver malignancy. As its name suggests these tumours arise in the bile ducts. Up to 80% of tumours arise in the extra hepatic biliary tree. Most patients present with jaundice and by this stage the majority will have disease that is not resectable. Primary sclerosing cholangitis is the main risk factor. In deprived countries typhoid and liver flukes are also major risk factors. Diagnosis Patients will typically have an obstructive picture on liver function tests. CA 19-9, CEA and CA 125 are often elevated CT/ MRI and MRCP are the imaging methods of choice. Treatment Surgical resection offers the best chance of cure. Local invasion of peri hilar tumours is a particular problem and this coupled with lobar atrophy will often contra indicate surgical resection. Palliation of jaundice is important, although metallic stents should be avoided in those considered for resection. Survival Is poor, approximately 5-10% 5 year survival.

Answer 1438

Dysplasia and cancer are not the same disease. All colonic adenomas are dysplastic. Adenomas greater than 2cm may harbor foci of malignancy within them. However, many have dysplastic cells only. These do not require segmental resection. When a cancer has been identified during endoscopy, it is safest to avoid undertaking polyp interventions as there is a risk of seeding. In summary, do NOT remove polyps until after the cancer has been resected. Colonic polyps Colonic Polyps May occur in isolation, or greater numbers as part of the polyposis syndromes. In FAP greater than 100 polyps are typically present. The risk of malignancy in association with adenomas is related to size, and is the order of 10% in a 1cm adenoma. Isolated adenomas seldom give risk of symptoms (unless large and distal). Distally sited villous lesions may produce mucous and if very large, electrolyte disturbances may occur. Follow up of colonic polyps Group Action Colorectal cancer Colonoscopy 1 year post resection Large non pedunculated colorectal polyps (LNPCP), R0 resection One off scope at 3 years Large non pedunculated colorectal polyps (LNPCP) R1 or non en bloc resection Site check at 2-6 months and then a further scope at 12 months High risk findings at baseline colonoscopy One off surveillance at 3 years No high risk findings at baseline colonoscopy No colonoscopic surveillance and invite participation in NHSBCSP programme when due High risk findings More than 2 premalignant polyps including 1 or more advanced colorectal polyps OR More than 5 pre malignant polyps Exceptions to guidelines If patient more than 10 years younger than lower screening age and has polyps but no high risk findings, consider colonoscopy at 5 or 10 years. Segmental resection or complete colectomy should be considered when: 1. Incomplete excision of malignant polyp 2. Malignant sessile polyp 3. Malignant pedunculated polyp with submucosal invasion 4. Polyps with poorly differentiated carcinoma 5. Familial polyposis coli -Screening from teenager up to 40 years by 2 yearly sigmoidoscopy/colonoscopy -Panproctocolectomy and Ileostomy or Restorative Panproctocolectomy. Rectal polypoidal lesions may be amenable to trans anal endoscopic microsurgery. References Rutter MD et al. British Society of Gastroenterology/Association of Coloproctology of Great Britain and Ireland/Public Health England post- polypectomy and post- colorectal cancer resection surveillance guidelines. Gut 2019;0:123.

Answer 1439

A Berrys sign= Absence of carotid pulse due to malignant thyromegaly. Papillary thyroid cancers will tend to spread via lymphatics and present with disease that is nearly always confined to the neck. Follicular carcinomas may metastasise haematogenously and the skull may be the presenting site of disease in between 2 and 8% of patients. Thyroid malignancy Papillary carcinoma Commonest sub-type Accurately diagnosed on fine needle aspiration cytology Histologically, they may demonstrate psammoma bodies (areas of calcification) and so called 'orphan Annie' nuclei They typically metastasise via the lymphatics and thus laterally located apparently ectopic thyroid tissue is usually a metastasis from a well differentiated papillary carcinoma Follicular carcinoma Are less common than papillary lesions Like papillary tumours, they may present as a discrete nodule. Although they appear to be well encapsulated macroscopically there is invasion on microscopic evaluation Lymph node metastases are uncommon and these tumours tend to spread haematogenously. This translates into a higher mortality rate Follicular lesions cannot be accurately diagnosed on fine needle aspiration cytology and thus all follicular FNA's (THY 3f) will require at least a hemi thyroidectomy Anaplastic carcinoma Less common and tend to occur in elderly females Disease is usually advanced at presentation and often only palliative decompression and radiotherapy can be offered. Medullary carcinoma These are tumours of the parafollicular cells ( C Cells) and are of neural crest origin. The serum calcitonin may be elevated which is of use when monitoring for recurrence. They may be familial and occur as part of the MEN -2A disease spectrum. Spread may be either lymphatic or haematogenous and as these tumours are not derived primarily from thyroid cells they are not responsive to radioiodine. Lymphoma These respond well to combined chemoradiotherapy Radical surgery is unnecessary once the disease has been diagnosed on biopsy material. Such biopsy material is not generated by an FNA and thus a core biopsy has to be obtained (with care!).

Answer 1440

Gliomas originate from glial (otherwise known as neuroglial) cells. These serve a structural function in the CNS. The tumours produced may resemble a number of CNS cell types. Tumours are therefore named according to the cells they resemble rather than the origin. Where this is not possible they are termed gliomas. Glioma Glioma is a tumour that is typically found in the CNS. These tumours arise from glial cells. They are sub categorised according to the cell type they most closely resemble. Glioma sub types Ependymomas- Ependymal cells Astocytomas- Astrocytes (including glioblastoma) Oligodendrogliomas- Oligodendrocytes Mixed- e.g. oligoastrocytomas Gliomas are categorised as being either high or low grade lesions (the former has the worse prognosis). They may be either supra or infra tentorial. Their symptoms will typically reflect their site of origin. Glioblastoma multiforme has the worst prognosis and few patients will survive beyond 12 months.

Answer 1441

Ulnar nerve Origin C8, T1 Supplies (no muscles in the upper arm) Flexor carpi ulnaris Flexor digitorum profundus Flexor digiti minimi Abductor digiti minimi Opponens digiti minimi Adductor pollicis Interossei muscle Third and fourth lumbricals Palmaris brevis Path Posteromedial aspect of upper arm to flexor compartment of forearm, then along the ulnar. Passes beneath the flexor carpi ulnaris muscle, then superficially over the flexor retinaculum into the palm of the hand. Branches Branch Supplies Muscular branch Flexor carpi ulnaris Medial half of the flexor digitorum profundus Palmar cutaneous branch (Arises near the middle of the forearm) Skin on the medial part of the palm Dorsal cutaneous branch Dorsal surface of the medial part of the hand Superficial branch Cutaneous fibres to the anterior surfaces of the medial one and one-half digits Deep branch Hypothenar muscles All the interosseous muscles Third and fourth lumbricals Adductor pollicis Medial head of the flexor pollicis brevis Effects of injury Damage at the wrist Wasting and paralysis of intrinsic hand muscles (claw hand) Wasting and paralysis of hypothenar muscles Loss of sensation medial 1 and half fingers Damage at the elbow Radial deviation of the wrist Clawing less in 4th and 5th digits

Answer 1442

Developmental dysplasia of the hip. Usually diagnosed by Barlow and Ortolani tests in early childhood. Most Breech deliveries are also routinely subjected to USS of the hip joint. At this young age an arthrodesis may be preferable to hip replacement. Paediatric orthopaedics Diagnosis Mode of presentation Treatment Radiology Developmental dysplasia of the hip Usually diagnosed in infancy by screening tests. May be bilateral, when disease is unilateral there may be leg length inequality. As disease progresses child may limp and then early onset arthritis. More common in extended breech babies. Splints and harnesses or traction. In later years osteotomy and hip realignment procedures may be needed. In arthritis a joint replacement may be needed. However, this is best deferred if possible as it will almost certainly require revision Initially no obvious change on plain films and USS gives best resolution until 3 months of age. On plain films Shentons line should form a smooth arc Perthes Disease Hip pain (may be referred to the knee) usually occurring between 5 and 12 years of age. Bilateral disease in 20%. Remove pressure from joint to allow normal development. Physiotherapy. Usually self-limiting if diagnosed and treated promptly. X-rays will show flattened femoral head. Eventually in untreated cases the femoral head will fragment. Slipped upper femoral epiphysis Typically seen in obese male adolescents. Pain is often referred to the knee. Limitation to internal rotation is usually seen. Knee pain is usually present 2 months prior to hip slipping. Bilateral in 20%. Bed rest and non-weight bearing. Aim to avoid avascular necrosis. If severe slippage or risk of it occurring then percutaneous pinning of the hip may be required. X-rays will show the femoral head displaced and falling inferolaterally (like a melting ice cream cone) The Southwick angle gives indication of disease severity

Answer 1443

The long history of left iliac fossa pain and development of bowel obstruction suggests a diverticular stricture. These may contain a malignancy and most will require resection. Whilst colonic Crohns strictures can occur, they would be quite rare in this age group, with this history as an isolated finding. Colonic obstruction Cause Features Treatment Cancer Usually insidious onset History of progressive constipation Systemic features (e.g. anaemia) Abdominal distension Absence of bowel gas distal to site of obstruction Establish diagnosis (e.g. contrast enema/ endoscopy) Laparotomy and resection, stenting, defunctioning colostomy or bypass Diverticular stricture Usually history of previous acute diverticulitis Long history of altered bowel habit Evidence of diverticulosis on imaging or endoscopy Once diagnosis established, usually surgical resection Colonic stenting should not be performed for benign disease Volvulus Twisting of bowel around its mesentery Sigmoid colon affected in 76% cases Patients usually present with abdominal pain, bloating and constipation Examination usually shows asymmetrical distension Plain X-rays usually show massively dilated sigmoid colon, loss of haustra and U shape are typical, the loop may contain fluid levels Initial treatment is to untwist the loop, a flexible sigmoidoscopy may be needed Those with clinical evidence of ischaemia should undergo surgery Patient with recurrent volvulus should undergo resection Acute colonic pseudo-obstruction Symptoms and signs of large bowel obstruction with no lesion Usually associated with metabolic disorders Usually a cut off in the left colon (82% cases) Although abdomen tense and distended, it is usually not painful All patients should undergo contrast enema (may be therapeutic) Colonoscopic decompression Correct metabolic disorders IV neostigmine Surgery

Answer 1444

Chest pain, hypoxia and clear chest on auscultation in pregnancy should lead to a high suspicion of pulmonary embolism. Chest pain in pregnancy Aortic dissection Predisposing factors in pregnancy are hypertension, congenital heart disease and Marfan's syndrome Mainly Stanford type A dissections Sudden tearing chest pain, transient syncope Patient may be cold and clammy, hypertensive and have an aortic regurgitation murmur Involvement of the right coronary artery may cause inferior myocardial infarction Surgical management Gestational timeframe Management < 28/40 Aortic repair with the fetus kept in utero 28-32/40 Dependent on fetal condition > 32/40 Primary Cesarean section followed by aortic repair at the same operation Mitral stenosis Most cases associated with rheumatic heart disease Becoming less common in British women; suspect in women who have moved recently to the country Commonest cardiac condition in pregnancy Commonly associated with mortality Valve surgery; balloon valvuloplasty preferable Pulmonary embolism Leading cause of mortality in pregnancy Half dose scintigraphy; CT chest if underlying lung disease, should aid diagnosis Treatment with low molecular weight heparin throughout pregnancy and 4-6 weeks after childbirth Warfarin is contra indicated in pregnancy (though may be continued in women with mechanical heart valves due to the significant risk of thromboembolism) References 1. Bates S.M. and Ginsberg J.S. How we manage venous thromboembolism during pregnancy. Blood 2002 (100): 3470-3478. 2. Scarsbrook A.Fand Gleeson V. Investigating suspected pulmonary embolism in pregnancy. BMJ 2007 (326) : 1135 doi: 10.1136/bmj.7399.1135. 3. Morley C. A. and Lim B. A. Lesson of the Week: The risks of delay in diagnosis of breathlessness in pregnancy. BMJ 1995 (311) : 1083.

Answer 1445

Prilocaine is a recognised cause of methaemoglobinaemia, this is characterised by the development of cyanosis and dyspnoea. This disorder occurs because of the change haemoglobin to a ferric subtype rather than ferrous (Fe2+). This type of change shifts the oxygen dissociation curve to the left and tissue hypoxia occurs. Methylene blue will revert the haemoglobin to the ferrous type and reverse this effect. Local anaesthetic toxicity Toxicity results from either accidental intravascular injection (rapid onset of symptoms-usually correct dose), or from excessive dosage (slower onset). Local anaesthetic agents not only exert a membrane stabilising effect on peripheral nerves but will also act on excitable membranes within the CNS and Heart. The sensory neurones in the CNS are suppressed before the motor ones. As a result the early symptoms will typically be those of circumoral paraesthesia and tinnitus, followed by falling GCS and eventually coma. Management of toxicity Stop injecting the anaesthetic agent High flow 100% oxygen via face mask Cardiovascular monitoring Administer lipid emulsion (Intralipid 20%) at 1.5ml/Kg over 1 minute as a bolus Consider lipid emulsion infusion, at 0.25ml/ Kg/ minute If toxicity due to prilocaine then administer methylene blue Safe doses 10ml of lignocaine 1% contains 100mg of drug, this would constitute 70% of the maximum safe dose in a 50 kg patient. Up to 7mg / kg can be administered if adrenaline is added to the solution. Doses of local anaesthetics Agent Dose plain Dose with adrenaline Lignocaine 3mg/Kg 7mg/Kg Bupivicane 2mg/Kg 2mg/Kg Prilocaine 6mg/Kg 9mg/Kg These are a guide only as actual doses depend on site of administration, tissue vascularity and co-morbidities.

Answer 1446

Chronic rejection of renal transplants is mediated via T lymphocytes and is therefore a type IV hypersensitivity reaction. This process can be mitigated by immunosupression. Organ Transplant A number of different organ and tissue transplants are now available. In many cases an allograft is performed, where an organ is transplanted from one individual to another. Allografts will elicit an immune response and this is one of the main reasons for organ rejection. Graft rejection occurs because allografts have allelic differences at genes that code immunohistocompatability complex genes. The main antigens that give rise to rejection are: ABO blood group Human leucocyte antigens (HLA) Minor histocompatability antigens ABO Matching ABO incompatibility will result in early organ rejection (hyperacute) because of pre existing antibodies to other groups. Group O donors can give organs to any type of ABO recipient whereas group AB donor can only donate to AB recipient. HLA System The four most important HLA alleles are: HLA A HLA B HLA C HLA DR An ideal organ match would be one in which all 8 alleles are matched (remember 2 from each parent, four each = 8 alleles). Modern immunosuppressive regimes help to manage the potential rejection due to HLA mismatching. However, the greater the number of mismatches the worse the long term outcome will be. T lymphocytes will recognise antigens bound to HLA molecules and will then become activated. Clonal expansion then occurs with a response directed against that antigen. Types of organ rejection Hyperacute. This occurs immediately through presence of pre formed antibodies (such as ABO incompatibility). Acute. Occurs during the first 6 months and is usually T cell mediated. Usually tissue infiltrates and vascular lesions. Chronic. Occurs after the first 6 months. Vascular changes predominate. Hyperacute Renal transplants at greatest risk and liver transplants at least risk. Although ABO incompatibility and HLA Class I incompatible transplants will all fare worse in long term. Acute All organs may undergo acute rejection. Mononuclear cell infiltrates predominate. All types of transplanted organ are susceptible and it may occur in up to 50% cases. Chronic Again all transplants with HLA mismatch may suffer this fate. Previous acute rejections and other immunosensitising events all increase the risk. Vascular changes are most prominent with myointimal proliferation leading to organ ischaemia. Organ specific changes are also seen such as loss of acinar cells in pancreas transplants and rapidly progressive coronary artery disease in cardiac transplants. Surgical overview-Renal transplantation A brief overview of the steps involved in renal transplantation is given. Patients with end stage renal failure who are dialysis dependent or likely to become so in the immediate future are considered for transplant. Exclusion criteria include; active malignancy, old age (due to limited organ availability). Patients are medically optimised. Donor kidneys, these may be taken from live related donors and close family, members may have less HLA mismatch than members of the general population. Laparoscopic donor nephrectomy further minimises the operative morbidity for the donor. Other organs are typically taken from brain dead or dying patients who have a cardiac arrest and in whom resuscitation is futile. The key event is to minimise the warm ischaemic time in the donor phase. The kidney once removed is usually prepared on the bench in theatre by the transplant surgeon immediately prior to implantation and factors such as accessory renal arteries and vessel length are assessed and managed. For first time recipients the operation is performed under general anaesthesia. A Rutherford-Morison incision is made on the preferred side. This provides excellent extraperitoneal access to the iliac vessels. The external iliac artery and vein are dissected out and following systemic heparinisation are cross clamped. The vein and artery are anastamosed to the iliacs and the clamps removed. The ureter is then implanted into the bladder and a stent is usually placed to maintain patency. The wounds are then closed and the patient recovered from surgery. In the immediate phase a common problem encountered in cadaveric kidneys is acute tubular necrosis and this tends to resolve. Graft survival times from cadaveric donors are typically of the order of 9 years and monozygotic twin transplant (live donor) may survive as long as 25 years.

Answer 1447

The median nerve lies close to the brachial artery in the antecubital fossa. This is the usual site of surgical access to the brachial artery for an embolectomy procedure. The median nerve may be damaged during clumsy application of vascular clamps to the artery. Brachial artery The brachial artery begins at the lower border of teres major as a continuation of the axillary artery. It terminates in the cubital fossa at the level of the neck of the radius by dividing into the radial and ulnar arteries. Relations Posterior relations include the long head of triceps with the radial nerve and profunda vessels intervening. Anteriorly it is overlapped by the medial border of biceps. It is crossed by the median nerve in the middle of the arm. In the cubital fossa it is separated from the median cubital vein by the bicipital aponeurosis. The basilic vein is in contact at the most proximal aspect of the cubital fossa and lies medially.

Answer 1448

The prostate lymphatic drainage is primarily to the internal iliac nodes and also the sacral nodes. Although internal iliac is the first site. Prostate gland The prostate gland is approximately the shape and size of a walnut and is located inferior to the bladder. It is separated from the rectum by Denonvilliers fascia and its blood supply is derived from the internal iliac vessels (via inferior vesical artery). The internal sphincter lies at the apex of the gland and may be damaged during prostatic surgery, affected individuals may complain of retrograde ejaculation. Summary of prostate gland Arterial supply Inferior vesical artery (from internal iliac) Venous drainage Prostatic venous plexus (to paravertebral veins) Lymphatic drainage Internal iliac nodes Innervation Inferior hypogastric plexus Dimensions Transverse diameter (4cm) AP diameter (2cm) Height (3cm) Lobes Posterior lobe: posterior to urethra Median lobe: posterior to urethra, in between ejaculatory ducts Lateral lobes x 2 Isthmus Zones Peripheral zone: subcapsular portion of posterior prostate. Most prostate cancers are here Central zone Transition zone Stroma Relations Anterior Pubic symphysis Prostatic venous plexus Posterior Denonvilliers fascia Rectum Ejaculatory ducts Lateral Venous plexus (lies on prostate) Levator ani (immediately below the puboprostatic ligaments)

Answer 1449

Both skin dimpling and nipple retraction are features of breast malignancy. However, they usually occur as a result of tumour infiltration of the breast ligaments and ducts respectively. The clavipectoral fascia encases the axillary contents. The lymphatic drainage of the breast is to the axilla and also to the internal mammary chain. The breast is well vascularised and the internal mammary artery is a branch of the subclavian artery. Breast The breast itself lies on a layer of pectoral fascia and the following muscles: 1. Pectoralis major 2. Serratus anterior 3. External oblique Breast anatomy Nerve supply Branches of intercostal nerves from T4-T6. Arterial supply Internal mammary (thoracic) artery External mammary artery (laterally) Anterior intercostal arteries Thoraco-acromial artery Venous drainage Superficial venous plexus to subclavian, axillary and intercostal veins. Lymphatic drainage 70% Axillary nodes Internal mammary chain Other lymphatic sites such as deep cervical and supraclavicular fossa (later in disease)

Answer 1450

A testis at the base of the penis is ectopic, not listed is the superficial inguinal pouch (one of the commonest ectopic sites). A testis located at deep or superficial rings or intra canalicular is not ectopically located. Testicular embryology Until the end of foetal life the testicles are located within the abdominal cavity. They are initially located on the posterior abdominal wall on a level with the upper lumbar vertebrae (L2). Attached to the inferior aspect of the testis is the gubernaculum testis which extends caudally to the inguinal region, through the canal and down to the superficial skin. Both the testis and the gubernaculum are extra-peritoneal. As the foetus grows the gubernaculum becomes progressively shorter. It carries the peritoneum of the anterior abdominal wall (the processus vaginalis). As the processus vaginalis descends the testis is guided by the gubernaculum down the posterior abdominal wall and the back of the processus vaginalis into the scrotum. By the third month of foetal life the testes are located in the iliac fossae, by the seventh they lie at the level of the deep inguinal ring. The processus vaginalis usually closes after birth, but may persist and be the site of indirect hernias. Part closure may result in development of cysts on the cord.

Answer 1451

This wound should be amenable to primary closure. There is minimal associated tissue loss and the surgery is minor and uncontaminated. Tissue reconstruction Skin Grafts and Flaps Skin flaps or grafts may be required where primary wound closure cannot be achieved or would entail either significant cosmetic defect or considerable functional disturbance as a result of wound contraction. Reconstructive ladder Method Types Direct closure The simplest option where possible Grafting techniques Split thickness Full thickness Skin Substitute Composite Flap technique Local: Transposition Pivot Alphabetoplasty (e.g. Z-Y) Regional: Myocutaneous Fasciocutaneous Neurocutaneous Distant: Free tissue transfer Prelamination techniques Allows creation of specialised flaps e.g. buccal mucosa Tissue expansion Involves placement of tissue expanders to increase amount of tissue at donor sites Skin Grafts Vs. Flaps Skin Grafts Flaps No size limit (Split)/ Relative size limit (full thickness) Size limited by territory of blood supply Rely on wound bed for blood supply Tissue has its own blood supply Take better on clean well vascularised wound beds Will survive independent of the wound bed Split skin graft donor site typically heals in 12 days Direct closure of donor site or secondary skin graft Donor site may be reused Donor site cannot be reused Split thickness skin grafts Available in range of thicknesses. Thigh is the commonest donor site Size may be increased by meshing the graft. However this comes with compromise on cosmesis. Donor sites, especially if thin grafts are taken can be reused following re-epithelialisation Full thickness grafts Most commonly used for facial reconstruction Include dermal appendages Provide superior cosmetic result Composite grafts These are grafts containing more than one tissue type, such as skin and fat. They are usually used to cover small defects in cosmetically important areas. Flaps Flaps have their own blood supply and may be pedicled or free. May have multiple components e.g. skin, skin + fat, skin + fat + muscle. They will have the ability to take regardless of the underlying tissue bed. The type of intrinsic blood supply is important. For example in breast surgery pedicled latissimus dorsi flaps will be less prone to failure than microsvascular anastomosed free Diep flaps.

Answer 1452

These results show a restrictive picture, which may result from a number of conditions including kyphoscoliosis. The other answers cause an obstructive picture. We note that most people have chosen COPD as the answer. In COPD the FEV1/FVC would show an obstructive picture with the FEV1/FVC value being low (approximately less than 70%). In restrictive conditions the FEV1/FVC is normal or increased (greater than 70%). With the FEV1/FVC being over 70% the most likely answer is kyphoscoliosis. Pulmonary function tests Pulmonary function tests can be used to determine whether a respiratory disease is obstructive or restrictive. The table below summarises the main findings and gives some example conditions: Obstructive lung disease Restrictive lung disease FEV1 - significantly reduced FVC - reduced or normal FEV1% (FEV1/FVC) - reduced (less than approx. 70%) FEV1 - reduced FVC - significantly reduced FEV1% (FEV1/FVC) - normal or increased (over approx. 70%) Asthma COPD Bronchiectasis Bronchiolitis obliterans Pulmonary fibrosis Asbestosis Sarcoidosis Acute respiratory distress syndrome Infant respiratory distress syndrome Kyphoscoliosis Neuromuscular disorders If you would like to read more about pulmonary function tests, here is a link that may be useful: Interpreting pulmonary function tests: Recognize the pattern, and the diagnosis will follow http://www.ccjm.org/content/70/10/866.full.pdf

Answer 1453

Vitamin B12. The others are unaffected Post gastrectomy syndrome Rapid emptying of food from stomach into the duodenum: diarrhoea, abdominal pain, hypoglycaemia Complications: Vitamin B12 and iron malabsorption, osteoporosis Treatment: High protein, low carbohydrate diet. Replace B12/Fe/Ca Gastric emptying The stomach serves both a mechanical and immunological function. Solid and liquid are retained in the stomach during which time repeated peristaltic activity against a closed pyloric sphincter will cause fragmentation of food bolus material. Contact with gastric acid will help to neutralise any pathogens present. The amount of time material spends in the stomach is related to its composition and volume. For example a glass of water will empty more quickly than a large meal. The presence of amino acids and fat will all serve to delay gastric emptying. Controlling factors Neuronal stimulation of the stomach is mediated via the vagus and the parasympathetic nervous system will tend to favor an increase in gastric motility. It is for this reason that individuals who have undergone truncal vagotomy will tend to routinely require either a pyloroplasty or gastro-enterostomy as they would otherwise have delayed gastric emptying. The following hormonal factors are all involved: Delay emptying Increase emptying Gastric inhibitory peptide Gastrin Cholecystokinin Enteroglucagon Diseases affecting gastric emptying All diseases that affect gastric emptying may result in bacterial overgrowth, retained food and eventually the formation of bezoars that may occlude the pylorus and make gastric emptying even worse. Fermentation of food may cause dyspepsia, reflux and foul smelling belches of gas. Iatrogenic Gastric surgery can have profound effects on gastric emptying. As stated above any procedure that disrupts the vagus can cause delayed emptying. Whilst this is particularly true of vagotomy, this operation is now rarely performed. Surgeons are divided on the importance of vagal disruption that occurs during an oesophagectomy, some will routinely perform a pyloroplasty and others will not. When a distal gastrectomy is performed, the type of anastomosis performed will impact on emptying. When a gastro-enterostomy is constructed, a posterior, retrocolic gastroenterostomy will empty better than an anterior one. Diabetic gastroparesis This is predominantly due to neuropathy affecting the vagus nerve. The stomach empties poorly and patients may have episodes of repeated and protracted vomiting. Diagnosis is made by upper GI endoscopy and contrast studies, in some cases a radio nucleotide scan is needed to demonstrate the abnormality more clearly. In treating these conditions, drugs such as metoclopramide will be less effective as they exert their effect via the vagus nerve. One of the few prokinetic drugs that do not work in this way is the antibiotic erythromycin. Malignancies Obviously a distal gastric cancer may obstruct the pylorus and delay emptying. In addition, malignancies of the pancreas may cause extrinsic compression of the duodenum and delay emptying. Treatment in these cases is by gastric decompression using a wide bore nasogastric tube and insertion of a stent or, if that is not possible, by a surgical gastroenterostomy. As a general rule gastroenterostomies constructed for bypass of malignancy are usually placed on the anterior wall of the stomach (in spite of the fact that they empty less well). A Roux en Y bypass may also be undertaken, but the increased number of anastomoses for this, in malignant disease that is being palliated, is probably not justified. Congenital Hypertrophic Pyloric Stenosis This is typically a disease of infancy. Most babies will present around 6 weeks of age with projectile non bile stained vomiting. It has an incidence of 2.4 per 1000 live births and is more common in males. Diagnosis is usually made by careful history and examination and a mass may be palpable in the epigastrium (often cited seldom felt!). The most important diagnostic test is an ultrasound that usually demonstrates the hypertrophied pylorus. Blood tests may reveal a hypochloraemic metabolic alkalosis if the vomiting is long standing. Once the diagnosis is made the infant is resuscitated and a pyloromyotomy is performed (either open or laparoscopically). Once treated there are no long term sequelae.

Answer 1454

c. partially compensated respiratory acidosis Uncompensated: Coz or HCos normal Partially Compensated: Nothing is normal Compensated : PH is normal (7.4 baseline/neutral) Based on the blood gas results provided, the interpretation suggests a combination of respiratory and metabolic acidosis. Let’s break down the findings: 1. pH: The pH is below the normal range, indicating acidosis. 2. pO2: Lower than normal, indicating inadequate oxygenation, which is consistent with emphysema. 3. pCO2: Elevated, indicating respiratory acidosis, likely due to hypoventilation caused by emphysema. 4. Bicarbonate: Elevated, indicating metabolic compensation for the respiratory acidosis, which is consistent with the kidneys attempting to retain bicarbonate to buffer the acidic environment. Also high bicarbonate levels reveals that is a chronic condition. 5. Base Excess: Positive, further indicating metabolic compensation for the acidosis. Metabolic compensation wouldn’t be enough to compensate respiratory acidosis, because pH is still asidotic. • Blood Gas Interpretation: https://www.ncbi.nlm.nih.gov/books/NBK482250/

Answer 1455

The most likely causative organism in this scenario is “a. Actinomyces.” Actinomyces is a genus of bacteria commonly associated with the formation of dental plaques and can cause chronic granulomatous infections, including sinus tract formation, known as actinomycosis. The presence of yellow granules in the discharging pus, known as sulfur granules, is characteristic of actinomycosis. Source: • Actinomycosis: https://www.ncbi.nlm.nih.gov/books/NBK482243/

Answer 1456

When the inferior mesenteric artery (IMA) is completely occluded, collateral circulation becomes essential to supply blood to the affected territory, which includes the descending colon, sigmoid colon, and rectum. One of the major collateral pathways is through the middle colic artery. The middle colic artery arises from the superior mesenteric artery (SMA) and supplies blood to the transverse colon. When the IMA is occluded, blood from the SMA can flow retrograde into the middle colic artery, providing additional blood supply to the descending colon via collateral circulation. So, the most likely additional source of blood supply to the territory of the occluded IMA is indeed the “c. Middle colic artery.” Source: • Collateral Circulation: https://www.ncbi.nlm.nih.gov/books/NBK537222/

Answer 1457

Given the scenario described, the most likely cause of the patient’s respiratory insufficiency 24 hours after admission is b. Adult respiratory distress syndrome (ARDS). ARDS is a severe lung condition characterized by widespread inflammation in the lungs. It can develop as a complication of various traumatic injuries, including hemorrhagic shock and significant blood loss. In this case, the patient’s presentation of severe dyspnea requiring intubation and ventilation, following a traumatic injury and resuscitation with blood products and colloid, is consistent with ARDS. Other options can be ruled out based on the clinical presentation: a. ABO blood incompatibility: This typically manifests soon after blood transfusion with symptoms such as fever, chills, chest pain, and hemolysis, rather than delayed respiratory insufficiency. c. Congestive cardiac failure: While possible, given the patient’s young age and the acute onset of symptoms following trauma, ARDS is a more likely cause of respiratory insufficiency. d. Tension pneumothorax: This would typically present with acute onset dyspnea and hypoxia, but it is less likely 24 hours after admission and resuscitation. e. Viral pneumonitis: While viral infections can cause respiratory insufficiency, the patient’s history of trauma and resuscitation makes ARDS a more likely diagnosis. ARDS is a life-threatening condition that requires prompt recognition and management, including mechanical ventilation and supportive care. Close monitoring of the patient’s oxygenation status and respiratory function is essential in managing ARDS. Source: • Medscape. Acute Respiratory Distress Syndrome (ARDS). https://emedicine.medscape.com/article/165139-overview

Answer 1458

Based on the patient’s history, surgical procedure, and symptoms, the most likely diagnosis is e. Hyponatremia. Hyponatremia, or low sodium levels in the blood, can occur due to various reasons, including prolonged surgery with excessive intravenous fluids, especially if those fluids are hypotonic. Thiazide diuretics, which the patient is taking for hypertension, can also contribute to hyponatremia by causing increased sodium loss through urine. The reason of hyponatremia in that scenario is TURP Syndrome. TURP SYNDROME • Rapid absorption of a large-volume irrigation solution. • Can occur 15 min after resection or upto 24 hrs postop. • Incidence: 1 - 8% • Characterized by intravascular volume shifts and plasma-solute (osmolarity) effects: • Circulatory overload • Water intoxication • Hyponatremia • Hypoosmolality Hyperglycinemia • Hyperammonemia • Hemolysis The symptoms described—nausea, headache, agitation, and confusion—are consistent with the neurological manifestations of hyponatremia. In severe cases, hyponatremia can lead to cerebral edema and potentially life-threatening complications such as seizures and coma. The other options are less likely: a. Hypercalcemia: Unlikely given the patient’s presentation and medical history. b. Hyperuricemia: Typically does not present with symptoms such as nausea, headache, agitation, and confusion. c. Hypoglycemia: Possible but less likely, especially considering the patient’s history of hypertension and thiazide diuretic use. Hypoglycemia would typically be addressed perioperatively to prevent such complications. d. Hypokalemia: Less likely given that thiazide diuretics can lead to potassium loss, but the symptoms described are more indicative of hyponatremia. Management of hyponatremia involves careful assessment of fluid status and electrolyte levels, followed by appropriate correction based on the severity of symptoms and underlying cause. Source: • Medscape. Hyponatremia. https://emedicine.medscape.com/article/242166-overview

Answer 1459

Based on the patient’s history, surgical procedure, and symptoms, the most likely diagnosis is e. Hyponatremia. Hyponatremia, or low sodium levels in the blood, can occur due to various reasons, including prolonged surgery with excessive intravenous fluids, especially if those fluids are hypotonic. Thiazide diuretics, which the patient is taking for hypertension, can also contribute to hyponatremia by causing increased sodium loss through urine. The reason of hyponatremia in that scenario is TURP Syndrome. TURP SYNDROME • Rapid absorption of a large-volume irrigation solution. • Can occur 15 min after resection or upto 24 hrs postop. • Incidence: 1 - 8% • Characterized by intravascular volume shifts and plasma-solute (osmolarity) effects: • Circulatory overload • Water intoxication • Hyponatremia • Hypoosmolality Hyperglycinemia • Hyperammonemia • Hemolysis The symptoms described—nausea, headache, agitation, and confusion—are consistent with the neurological manifestations of hyponatremia. In severe cases, hyponatremia can lead to cerebral edema and potentially life-threatening complications such as seizures and coma. The other options are less likely: a. Hypercalcemia: Unlikely given the patient’s presentation and medical history. b. Hyperuricemia: Typically does not present with symptoms such as nausea, headache, agitation, and confusion. c. Hypoglycemia: Possible but less likely, especially considering the patient’s history of hypertension and thiazide diuretic use. Hypoglycemia would typically be addressed perioperatively to prevent such complications. d. Hypokalemia: Less likely given that thiazide diuretics can lead to potassium loss, but the symptoms described are more indicative of hyponatremia. Management of hyponatremia involves careful assessment of fluid status and electrolyte levels, followed by appropriate correction based on the severity of symptoms and underlying cause. Source: • Medscape. Hyponatremia. https://emedicine.medscape.com/article/242166-overview

Answer 1460

The most likely pair of cranial nerves to be compressed by a tumor of the cerebellopontine angle is c. Facial and vestibulocochlear. Tumors in the cerebellopontine angle can compress the nerves located in this region. The facial nerve (CN VII) and vestibulocochlear nerve (CN VIII) are commonly affected due to their proximity to this area. Compression of the facial nerve can lead to facial weakness or paralysis, while compression of the vestibulocochlear nerve can cause symptoms such as hearing loss, tinnitus, and vertigo. Options a, b, d, and e involve cranial nerves that are less likely to be affected by a tumor in the cerebellopontine angle. Source: • UpToDate. Overview of Tumors of the Cerebellopontine Angle. https://www.uptodate.com/contents/overview-of-tumors-of-the-cerebellopontine-angle

Answer 1461

Given the presentation of erectile dysfunction following rectal tumor resection, the most likely nerve to have been damaged in surgery is c. Pelvic splanchnic nerves. (Aka Hypogastric) The pelvic splanchnic nerves, also known as the pelvic autonomic nerves or parasympathetic pelvic nerves, are crucial for sexual function. Damage to these nerves during rectal surgery can lead to erectile dysfunction due to disruption of the parasympathetic innervation to the genitalia.

Answer 1462

The most likely diagnosis for the 45-year-old woman with pain, swelling, stiffness, weakness in grip, and inability to fully extend her fingers, along with ulnar deviation in the index, middle, and ring fingers in both hands is **e. rheumatoid arthritis**. This condition typically presents with symmetrical joint involvement, deformities like ulnar deviation, and systemic symptoms affecting multiple joints[5]. Dupuytren's contracture primarily affects the palm and fingers with a different presentation involving bending of the fingers towards the palm without joint inflammation or systemic symptoms[4]. Gouty arthritis is characterized by sudden attacks of severe pain, redness, and swelling in a single joint due to uric acid crystal deposits[5]. Osteoarthritis is more common in older individuals and affects specific joints without systemic symptoms like those described[5]. Radial nerve palsy would lead to specific weakness and sensory changes in the distribution of the radial nerve, not the described symptoms[5]. Sources [1] Dupuytren's contracture - NHS https://www.nhs.uk/conditions/dupuytrens-contracture/ [2] Dupuytren contracture - Symptoms and causes - Mayo Clinic https://www.mayoclinic.org/diseases-conditions/dupuytrens-contracture/symptoms-causes/syc-20371943 [3] Dupuytren's Disease - Dupuytren's Contracture - OrthoInfo - AAOS https://orthoinfo.aaos.org/en/diseases--conditions/dupuytrens-disease/ [4] Dupuytren's Contracture: What is it? Symptoms, Causes & Treatment https://www.assh.org/handcare/condition/dupuytrens-contracture [5] Dupuytren's disease | The British Society for Surgery of the Hand https://www.bssh.ac.uk/patients/conditions/25/dupuytrens_disease

Answer 1463

The most likely cause of acute hemorrhage in a 22-year-old man with a large pneumothorax after chest drain insertion into the fifth left intercostal space is the **intercostal artery**[1][2]. Sources [1] Management of a life-threatening intercostal artery bleeding, difficult ... https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7602520/ [2] Iatrogenic injury to the intercostal artery: aetiology, diagnosis and ... https://thorax.bmj.com/content/70/8/802 [3] Control of bleeding from intercostal artery laceration - ScienceDirect https://www.sciencedirect.com/science/article/pii/S2213007122002052 [4] Massive hemorrhage from the posterior intercostal artery following ... https://cardiothoracicsurgery.biomedcentral.com/articles/10.1186/s13019-021-01718-1 [5] Lethal intercostal artery injury after a fall - Shen https://qims.amegroups.org/article/view/85565/html

Answer 1464

Based on the provided sources, the process most likely responsible for the deterioration in renal function after a cadaveric renal transplant in a 38-year-old man with polycystic kidney disease is **e. T-cell mediated rejection**. T-cell mediated rejection is a significant factor in graft failure and can lead to a decline in kidney function over time[5][5]. This type of rejection involves T cells recognizing the transplanted kidney as foreign and initiating an immune response against it, contributing to tissue damage and loss of function[5][5]. Understanding T-cell mediated rejection is crucial in managing post-transplant complications and ensuring the long-term success of renal transplants[5][5]. Sources [1] Safety of CAR T-cell therapy in kidney transplant recipients - PMC - NCBI https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8109014/ [2] Immunosuppression Considerations for Older Kidney Transplant ... https://link.springer.com/article/10.1007/s40472-021-00321-6 [3] Combined Bone Marrow and Kidney Transplantation for the Induction of ... https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4867066/ [4] Transplanting the Elderly: Mandatory Age- and Minimal Histocompatibility ... https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2020.00359/full [5] The development of adult T cell leukemia/lymphoma in renal ... https://rrtjournal.biomedcentral.com/articles/10.1186/s41100-023-00480-5

Answer 1465

In the dissection down to the right axillary artery, the first structure encountered would be the **Thoracoacromial artery**[1][2][3][4]. This artery arises from the second part of the axillary artery and contributes to the blood supply of the shoulder and pectoral region. It passes inferiorly along the medial border of the pectoralis minor muscle before dividing into four terminal branches: Pectoral, Acromial, Clavicular, and Deltoid. Therefore, as you dissect down to the right axillary artery from a point just lateral to the sternal end of the clavicle to the deltopectoral groove, you would encounter the thoracoacromial artery first. Sources [1] The Thoracoacromial Artery - Course - Supply - TeachMeAnatomy https://teachmeanatomy.info/encyclopaedia/t/thoracoacromial-artery/ [2] Thoracoacromial artery - Wikipedia https://en.wikipedia.org/wiki/Thoracoacromial_artery [3] Thoracoacromial artery | Radiology Reference Article | Radiopaedia.org https://radiopaedia.org/articles/thoracoacromial-artery?lang=gb [4] Thoracoacromial artery: Anatomy, branches, supply - Kenhub https://www.kenhub.com/en/library/anatomy/thoracoacromial-artery [5] The Lateral Thoracic Vessels: A Useful Recipient in Immediate ... https://www.thieme-connect.com/products/ejournals/pdf/10.1055/s-0035-1570535.pdf

Answer 1466

The obstruction in the 4-year-old boy with hydrocephalus is most likely to be at the Cerebral aqueduct (of Sylvius) [4]. This site is a common location for obstructions that lead to hydrocephalus, causing dilatation of the lateral and third ventricles while the fourth ventricle remains normal in size. Sources [1] Hydrocephalus - Symptoms and causes - Mayo Clinic https://www.mayoclinic.org/diseases-conditions/hydrocephalus/symptoms-causes/syc-20373604 [2] Hydrocephalus | National Institute of Neurological Disorders and Stroke https://www.ninds.nih.gov/health-information/disorders/hydrocephalus [3] Hydrocephalus | Johns Hopkins Medicine https://www.hopkinsmedicine.org/health/conditions-and-diseases/hydrocephalus [4] Obstructive Hydrocephalus - Birmingham, AL https://neurosurgicalassociatespc.com/obstructive-hydrocephalus/ [5] Hydrocephalus and CSF Disorders - Diseases of the Brain, Head ... - NCBI https://www.ncbi.nlm.nih.gov/books/NBK554339/

Answer 1467

The immunoglobulin most likely to cause the allergic reaction described in the scenario of a 12-year-old boy with symptoms after cutting grass is IgE. IgE is associated with allergic reactions and plays a crucial role in allergic responses, triggering the release of histamine and other chemicals that lead to allergy symptoms like rhinorrhea, itchy eyes, sneezing, and nasal congestion. ACID (Acute-Cytotoxic-Immune Mediated-Delayed—->EGGT (IgE-IgG-IgG-T cell) Sources [1] Biochemistry, Immunoglobulin A - StatPearls - NCBI Bookshelf https://www.ncbi.nlm.nih.gov/books/NBK551516/ [2] Immunoglobulin A Deficiency | Johns Hopkins Medicine https://www.hopkinsmedicine.org/health/conditions-and-diseases/immunoglobulin-a-deficiency [3] Immunoglobulin A - Wikipedia https://en.wikipedia.org/wiki/Immunoglobulin_A [4] Adverse Reactions to Intravenous Immunoglobulins - Our Experience https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6311486/ [5] Immunoglobulin A (IgA) | British Society for Immunology https://www.immunology.org/public-information/bitesized-immunology/receptors-molecules/immunoglobulin-iga

Answer 1468

In this scenario, given the patient’s condition and the need for a femoral arterial blood gas sample, the most appropriate landmark to use would be: “A point midway between the anterior superior iliac spine and the pubic symphysis.” This location is commonly referred to as the femoral triangle and is a standard site for arterial puncture procedures due to its accessibility and proximity to the femoral artery. Properly identifying this landmark ensures accurate placement of the needle for the arterial blood gas sampling procedure. Always ensure to adhere to proper aseptic technique and consult institutional guidelines or healthcare professionals for specific protocols related to arterial puncture procedures. For further reference: • https://www.ncbi.nlm.nih.gov/books/NBK430789/ • https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5542529/

Answer 1469

The likely nerve that has been damaged in the 70-year-old man experiencing persistent numbness following inguinal hernia repair is the **Ilioinguinal nerve**[3]. This nerve is commonly encountered during hernia repair surgeries and can be affected, leading to symptoms like numbness in specific areas such as the top of the scrotum, root of the penis, and below the medial part of the inguinal ligament. The ilioinguinal nerve is one of the nerves identified during open inguinal hernia repair, with an identification rate of 82% in surgeries[3]. Damage to this nerve can result in sensory disturbances and persistent numbness in the described regions. Sources [1] Inguinal hernia repair - NHS https://www.nhs.uk/conditions/inguinal-hernia-repair/ [2] Management of chronic pain after hernia repair - PMC - NCBI https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5896652/ [3] Nerve identification during open inguinal hernia repair: a system… https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10598160/ [4] Post Operative Pain: Inguinal Hernia Surgery with Mesh https://www.anthonyechomd.com/blog/post-operative-pain-inguinal-hernia-surgery-with-mesh [5] Relief for Post-Surgery Hernia Pain - Verywell Health https://www.verywellhealth.com/chronic-post-hernia-repair-pain-2564628

Answer 1470

In this scenario, the most likely positive test would be for d. Antiphospholipid antibodies. Antiphospholipid syndrome (APS) is an autoimmune disorder characterized by the presence of antiphospholipid antibodies in the blood, which can lead to a tendency to develop blood clots. Pregnant women with APS are at an increased risk of complications such as deep vein thrombosis (DVT) or pulmonary embolism (PE), which could result in swollen legs. Additionally, APS is known to have a familial predisposition, which aligns with the history of similar problems during pregnancy in the patient’s mother and maternal aunt. The other options listed are associated with different autoimmune conditions and are less likely to be relevant in this context: a. Antiendomysial antibodies: Associated with celiac disease, a condition involving gluten intolerance. b. Antimitochondrial antibodies: Typically found in primary biliary cholangitis, a chronic liver disease. c. Antinuclear antibodies: Often present in systemic autoimmune diseases like systemic lupus erythematosus (SLE). e. Antithyroglobulin antibodies: Associated with autoimmune thyroid disorders such as Hashimoto’s thyroiditis. Therefore, the most appropriate choice is d. Antiphospholipid antibodies. Antiphospholipid antibody syndrome (APS) • Recurrent arterial or venous thromboses and/or pregnancy morbidity with the persistent presence of anticardiolipin antibodies or lupus anticoagulant Major types of antiphospholipid antibody • False positive serologic test for syphilis • Lupus anticoagulant : positive in 30% of lupus • Anticardiolipin antibody : positive in 40-47% of lupus • Anti-ß2 - glycoprotein I antibody

Answer 1471

The primary metabolic effect of epinephrine is c. Glycolysis. Epinephrine stimulates the breakdown of glycogen into glucose, which is then utilized for energy production via glycolysis. This process provides a quick source of energy to support the increased metabolic demands associated with the “fight or flight” response. Glycolysis is essential for rapidly generating ATP (adenosine triphosphate), the primary energy currency of cells, to fuel various physiological processes needed during times of stress or physical exertion. While epinephrine can also lead to effects such as tachycardia (increased heart rate) and vasoconstriction (narrowing of blood vessels), these are primarily related to its role in increasing cardiac output and redirecting blood flow to vital organs during stressful situations. However, the primary metabolic effect, particularly in terms of energy production, is the promotion of glycolysis.

Answer 1472

The physiological parameters consistent with sepsis are: C-Heart Rate increased / Systemic vascular resistance decreased / Cardiac output increased In sepsis, there is typically an increase in heart rate (tachycardia) as the body’s response to the infection. Systemic vascular resistance tends to decrease due to the systemic inflammatory response, leading to vasodilation. Consequently, cardiac output often increases initially to compensate for the decreased vascular resistance and to maintain tissue perfusion. This pattern of increased heart rate, decreased systemic vascular resistance, and increased cardiac output is characteristic of the hyperdynamic state seen in sepsis. So, option C is the correct choice.

Answer 1473

The pre-malignant change described in the scenario is: b. Dysplasia Dysplasia refers to the abnormal growth or development of cells within a tissue or organ. In the context of inflammatory bowel disease (IBD), such as pancolitis, patients are at increased risk of developing dysplasia, which can progress to colorectal cancer if left untreated. Therefore, surveillance colonoscopies are recommended for early detection of dysplastic changes in patients with long-standing IBD.

Answer 1474

During a cystectomy for bladder carcinoma, the ureters pierce the bladder wall at the **posterior surface**[2]. Sources [1] Cystectomy (bladder removal) - surgery for bladder cancer https://www.macmillan.org.uk/cancer-information-and-support/treatments-and-drugs/cystectomy-removing-the-bladder [2] Bladder removal surgery (cystectomy) - Mayo Clinic https://www.mayoclinic.org/tests-procedures/cystectomy/about/pac-20385108 [3] Bladder reconstruction (neobladder) - Macmillan Canc… https://www.macmillan.org.uk/cancer-information-and-support/impacts-of-cancer/bladder-reconstruction [4] Surgery to remove the bladder (cystectomy) - Cancer Research UK https://www.cancerresearchuk.org/about-cancer/bladder-cancer/treatment/invasive/surgery/removing-bladder [5] Cystectomy (Bladder Removal): Procedure, Risks & Recovery https://my.clevelandclinic.org/health/treatments/21049-cystectomy

Answer 1475

When performing a tracheostomy via the second, third, and fourth tracheal rings, the structure most likely to require transaction is the thyroid isthmus, which is typically located between the second and third tracheal rings. So, the correct answer is: e. Thyroid isthmus This is because the thyroid isthmus is usually positioned just below the cricoid cartilage and may need to be divided or retracted during the tracheostomy procedure to access the trachea properly.

Answer 1476

Of the agents mentioned, etomidate has the most favorable cardiac safety profile. Anaesthetic agents The table below summarises some of the more commonly used IV induction agents Agent Specific features Propofol Rapid onset of anaesthesia Pain on IV injection Rapidly metabolised with little accumulation of metabolites Proven anti emetic properties Moderate myocardial depression Widely used especially for maintaining sedation on ITU, total IV anaesthesia and for daycase surgery Sodium thiopentone Extremely rapid onset of action making it the agent of choice for rapid sequence of induction Marked myocardial depression may occur Metabolites build up quickly Unsuitable for maintenance infusion Little analgesic effects Ketamine May be used for induction of anaesthesia Has moderate to strong analgesic properties Produces little myocardial depression making it a suitable agent for anaesthesia in those who are haemodynamically unstable May induce state of dissociative anaesthesia resulting in nightmares Etomidate Has favorable cardiac safety profile with very little haemodynamic instability No analgesic properties Unsuitable for maintaining sedation as prolonged (and even brief) use may result in adrenal suppression Post operative vomiting is common

Answer 1477

Upper midline abdominal incisions will involve the division of the linea alba. Division of muscles will not usually improve access in this approach and they would not be routinely encountered during this incision. Abdominal incisions Midline incision Commonest approach to the abdomen Structures divided: linea alba, transversalis fascia, extraperitoneal fat, peritoneum (avoid falciform ligament above the umbilicus) Bladder can be accessed via an extraperitoneal approach through the space of Retzius Paramedian incision Parallel to the midline (about 3-4cm) Structures divided/retracted: anterior rectus sheath, rectus (retracted), posterior rectus sheath, transversalis fascia, extraperitoneal fat, peritoneum Incision is closed in layers Battle Similar location to paramedian but rectus displaced medially (and thus denervated) Now seldom used Kocher's Incision under right subcostal margin e.g. Cholecystectomy (open) Lanz Incision in right iliac fossa e.g. Appendicectomy Gridiron Oblique incision centered over McBurneys point- usually appendicectomy (less cosmetically acceptable than Lanz Gable Rooftop incision Pfannenstiel's Transverse supra pubic, primarily used to access pelvic organs McEvedy's Groin incision e.g. Emergency repair strangulated femoral hernia Rutherford Morrison Extraperitoneal approach to left or right lower quadrants. Gives excellent access to iliac vessels and is the approach of choice for first time renal transplantation.

Answer 1478

The vagus lies in the carotid sheath. The hypoglossal nerve crosses the sheath, but does not lie within it. Common carotid artery The right common carotid artery arises at the bifurcation of the brachiocephalic trunk, the left common carotid arises from the arch of the aorta. Both terminate at the level of the upper border of the thyroid cartilage (the lower border of the third cervical vertebra) by dividing into the internal and external carotid arteries. Left common carotid artery This vessel arises immediately to the left and slightly behind the origin of the brachiocephalic trunk. Its thoracic portion is 2.5- 3.5 cm in length and runs superolaterally to the sternoclavicular joint. In the thorax The vessel is in contact, from below upwards, with the trachea, left recurrent laryngeal nerve, left margin of the oesophagus. Anteriorly the left brachiocephalic vein runs across the artery, and the cardiac branches from the left vagus descend in front of it. These structures together with the thymus and the anterior margins of the left lung and pleura separate the artery from the manubrium. In the neck The artery runs superiorly deep to sternocleidomastoid and then enters the anterior triangle. At this point it lies within the carotid sheath with the vagus nerve and the internal jugular vein. Posteriorly the sympathetic trunk lies between the vessel and the prevertebral fascia. At the level of C7 the vertebral artery and thoracic duct lie behind it. The anterior tubercle of C6 transverse process is prominent and the artery can be compressed against this structure (it corresponds to the level of the cricoid). Anteriorly at C6 the omohyoid muscle passes superficial to the artery. Within the carotid sheath the jugular vein lies lateral to the artery. Right common carotid artery The right common carotid arises from the brachiocephalic artery. The right common carotid artery corresponds with the cervical portion of the left common carotid, except that there is no thoracic duct on the right. The oesophagus is less closely related to the right carotid than the left. Summary points about the carotid anatomy Path Passes behind the sternoclavicular joint (12% patients above this level) to the upper border of the thyroid cartilage, to divide into the external (ECA) and internal carotid arteries (ICA). Relations Level of 6th cervical vertebra crossed by omohyoid Then passes deep to the thyrohyoid, sternohyoid, sternomastoid muscles. Passes anterior to the carotid tubercle (transverse process 6th cervical vertebra)-NB compression here stops haemorrhage. The inferior thyroid artery passes posterior to the common carotid artery. Then : Left common carotid artery crosses the thoracic duct, Right common carotid artery crossed by recurrent laryngeal nerve

Answer 1479

Marfans syndrome may present with a variety of connective tissue disorders such as bilateral inguinal hernia. They are at high risk of aortic dissection, as in this case. Aortic dissection More common than rupture of the abdominal aorta 33% of patients die within the first 24 hours, and 50% die within 48 hours if no treatment received Associated with hypertension Features of aortic dissection: tear in the intimal layer, followed by formation and propagation of a subintimal hematoma. Cystic medial necrosis (Marfan's) Most common site of dissection: 90% occurring within 10 centimetres of the aortic valve Stanford Classification Type Location Treatment A Ascending aorta/ aortic root Surgery- aortic root replacement B Descending aorta Medical therapy with antihypertensives DeBakey classification Type Site affected I Ascending aorta, aortic arch, descending aorta II Ascending aorta only III Descending aorta distal to left subclavian artery Clinical features Tearing, sudden onset chest pain (painless 10%) Hypertension or Hypotension A blood pressure difference (in each arm) greater than 20 mm Hg Neurologic deficits (20%) Investigations CXR: widened mediastinum, abnormal aortic knob, ring sign, deviation of the trachea/oesophagus CT angiography of the thoracic aorta MRI angiography Conventional angiography (now rarely used diagnostically) Management Beta-blockers: aim HR 60-80 bpm and systolic BP 100-120 mm Hg For type A dissections the standard of care is aortic root replacement

Answer 1480

Galeazzi fractures occur after a fall on the hand with a rotational force superimposed on it. On examination, there is bruising, swelling and tenderness over the lower end of the forearm. X- Rays reveal a displaced fracture of the radius and a prominent ulnar head due to dislocation of the inferior radio-ulnar joint. Upper limb fractures Colles' fracture Fall onto extended outstretched hands Described as a dinner fork type deformity Classical Colles' fractures have the following 3 features: Features of the injury 1. Transverse fracture of the radius 2. 1 inch proximal to the radio-carpal joint 3. Dorsal displacement and angulation Smith's fracture (reverse Colles' fracture) Volar angulation of distal radius fragment (Garden spade deformity) Caused by falling backwards onto the palm of an outstretched hand or falling with wrists flexed Bennett's fracture Intra-articular fracture of the first carpometacarpal joint Impact on flexed metacarpal, caused by fist fights X-ray: triangular fragment at ulnar base of metacarpal Monteggia's fracture Dislocation of the proximal radioulnar joint in association with an ulna fracture Fall on outstretched hand with forced pronation Needs prompt diagnosis to avoid disability Galeazzi fracture Radial shaft fracture with associated dislocation of the distal radioulnar joint Occur after a fall on the hand with a rotational force superimposed on it. On examination, there is bruising, swelling and tenderness over the lower end of the forearm. X Rays reveal the displaced fracture of the radius and a prominent ulnar head due to dislocation of the inferior radio-ulnar joint. Barton's fracture Distal radius fracture (Colles'/Smith's) with associated radiocarpal dislocation Fall onto extended and pronated wrist Scaphoid fractures Scaphoid fractures are the commonest carpal fractures. Surface of scaphoid is covered by articular cartilage with small area available for blood vessels (fracture risks blood supply) Forms floor of anatomical snuffbox Risk of fracture associated with fall onto outstretched hand (tubercle, waist, or proximal 1/3) The main physical signs are swelling and tenderness in the anatomical snuff box, and pain on wrist movements and on longitudinal compression of the thumb. Ulnar deviation AP needed for visualization of scaphoid Immobilization of scaphoid fractures difficult Radial head fracture Fracture of the radial head is common in young adults. It is usually caused by a fall on the outstretched hand. On examination, there is marked local tenderness over the head of the radius, impaired movements at the elbow, and a sharp pain at the lateral side of the elbow at the extremes of rotation (pronation and supination).

Answer 1481

Each digit has 3 phalanges, the thumb has two the total is therefore 14. Anatomy of the forearm and hand Forearm muscles Muscle Origin Insertion Nerve supply Action Flexor carpi radialis Common flexor origin and surrounding fascia Front of bases of second and third metacarpals Median Flexes and abducts the carpus, part flexes the elbow and part pronates forearm Palmaris longus Common flexor origin Apex of palmar aponeurosis Median Wrist flexor Flexor carpi ulnaris Small humeral head arises from the common flexor origin and adjacent fascia. Ulnar head comes from medial border of olecranon and posterior border of ulna Pisiform and base of the fifth metacarpal Ulnar nerve Flexes and adducts the carpus Flexor digitorum superficialis Long linear origin from common flexor tendon, adjacent fascia and septa and medial border of the coronoid process Via tendons in the fibrous flexor sheath. At the level of the metacarpophalangeal joint each tendon split into two, these bands pass distally to their insertions Median Flexor of metacarpophalangeal joint and proximal interphalangeal joint Flexor digitorum profundus Upper two thirds of the medial and anterior surface of the ulna, medial side of the olecranon, medial half of the interosseous membrane Via tendons that lie deep to those of flexor digitorum superficialis to insert into the distal phalanx Medial part= ulnar, lateral part=anterior interosseous nerve Flexes the distal interphalangeal joints and the wrist Anatomy of the hand Bones 8 Carpal bones 5 Metacarpals 14 phalanges Intrinsic Muscles 8 Interossei - Supplied by ulnar nerve 4 palmar-adduct fingers 4 dorsal- abduct fingers Intrinsic muscles Lumbricals Flex MCPJ and extend the IPJ. Origin deep flexor tendon and insertion dorsal extensor hood mechanism. Innervation: 1st and 2nd- median nerve, 3rd and 4th- deep branch of the ulnar nerve. Thenar eminence Abductor pollicis brevis Opponens pollicis Flexor pollicis brevis Hypothenar eminence Opponens digiti minimi Flexor digiti minimi brevis Abductor digiti minimi Fascia and compartments of the palm The fascia of the palm is continuous with the antebrachial fascia and the fascia of the dorsum of the hand. The palmar fascia is thin over the thenar and hypothenar eminences. In contrast the palmar fascia is relatively thick. The palmar aponeurosis covers the soft tissues and overlies the flexor tendons. The apex of the palmar aponeurosis is continuous with the flexor retinaculum and the palmaris longus tendon. Distally, it forms four longitudinal digital bands that attach to the bases of the proximal phalanges, blending with the fibrous digital sheaths. A medial fibrous septum extends deeply from the medial border of the palmar aponeurosis to the 5th metacarpal. Lying medial to this are the hypothenar muscles. In a similar fashion, a lateral fibrous septum extends deeply from the lateral border of the palmar aponeurosis to the 3rd metacarpal. The thenar compartment lies lateral to this area. Lying between the thenar and hypothenar compartments is the central compartment. It contains the flexor tendons and their sheaths, the lumbricals, the superficial palmar arterial arch and the digital vessels and nerves. The deepest muscular plane is the adductor compartment, which contains adductor pollicis. Short muscles of the hand These comprise the lumbricals and interossei. The four slender lumbrical muscles flex the fingers at the metacarpophalangeal joints and extend the interphalangeal joint. The four dorsal interossei are located between the metacarpals and the four palmar interossei lie on the palmar surface of the metacarpals in the interosseous compartment of the hand. Long flexor tendons and sheaths in the hand The tendons of FDS and FDP enter the common flexor sheath deep to the flexor retinaculum. The tendons enter the central compartment of the hand and fan out to their respective digital synovial sheaths. Near the base of the proximal phalanx, the tendon of FDS splits to permit the passage of FDP. The FDP tendons are attached to the margins of the anterior aspect of the base of the distal phalanx. The fibrous digital sheaths contain the flexor tendons and their synovial sheaths. These extend from the heads of the metacarpals to the base of the distal phalanges.

Answer 1482

The thoracoacromial artery arises from the second part of the axillary artery. It is a short, wide trunk, which pierces the clavipectoral fascia, and ends, deep to pectoralis major by dividing into four branches. Thoracoacromial artery The thoracoacromial artery (acromiothoracic artery; thoracic axis) is a short trunk, which arises from the forepart of the axillary artery, its origin being generally overlapped by the upper edge of the Pectoralis minor. Projecting forward to the upper border of the Pectoralis minor, it pierces the coracoclavicular fascia and divides into four branches: pectoral, acromial, clavicular, and deltoid. Branch Description Pectoral branch Descends between the two Pectoral muscles, and is distributed to them and to the breast, anastomosing with the intercostal branches of the internal thoracic artery and with the lateral thoracic. Acromial branch Runs laterally over the coracoid process and under the Deltoid, to which it gives branches; it then pierces that muscle and ends on the acromion in an arterial network formed by branches from the suprascapular, thoracoacromial, and posterior humeral circumflex arteries. Clavicular branch Runs upwards and medially to the sternoclavicular joint, supplying this articulation, and the Subclavius. Deltoid branch Arising with the acromial, it crosses over the Pectoralis minor and passes in the same groove as the cephalic vein, between the Pectoralis major and Deltoid, and gives branches to both muscles.

Answer 1483

B-Amoebic abscess Benign liver lesions Haemangioma Most common benign tumours of mesenchymal origin Incidence in autopsy series is 8% Cavernous haemangiomas may be enormous Clinically they are reddish purple hypervascular lesions Lesions are normally separated from normal liver by ring of fibrous tissue On ultrasound they are typically hyperechoic Liver cell adenoma 90% develop in women in their third to fifth decade Linked to use of oral contraceptive pill Lesions are usually solitary They are usually sharply demarcated from normal liver although they usually lack a fibrous capsule On ultrasound the appearances are of mixed echoity and heterogeneous texture. On CT most lesions are hypodense when imaged prior to administration of IV contrast agents In patients with haemorrhage or symptoms removal of the adenoma may be required Mesenchymal hamartomas Congential and benign, usually present in infants. May compress normal liver Liver abscess Biliary sepsis is a major predisposing factor Structures drained by the portal venous system form the second largest source Common symptoms include fever, right upper quadrant pain. Jaundice may be seen in 50% Ultrasound will usually show a fluid filled cavity, hyperechoic walls may be seen in chronic abscesses Amoebic abscess Liver abscess is the most common extra intestinal manifestation of amoebiasis Between 75 and 90% lesions occur in the right lobe Presenting complaints typically include fever and right upper quadrant pain Ultrasonography will usually show a fluid filled structure with poorly defined boundaries Aspiration yield sterile odourless fluid which has an anchovy paste consistency Treatment is with metronidazole Hyatid cysts Seen in cases of Echinococcus infection Typically an intense fibrotic reaction occurs around sites of infection The cyst has no epithelial lining Cysts are commonly unilocular and may grow to 20cm in size. The cyst wall is thick and has an external laminated hilar membrane and an internal enucleated germinal layer Typically presents with malaise and right upper quadrant pain. Secondary bacterial infection occurs in 10%. Liver function tests are usually abnormal and eosinophilia is present in 33% cases Ultrasound may show septa and hyatid sand or daughter cysts. Percutaneous aspiration was previously contra indicated, it is now incorporated into some treatment regimens Treatment is by sterilisation of the cyst with mebendazole and may be followed by surgical resection. Hypertonic swabs are packed around the cysts during surgery Polycystic liver disease Usually occurs in association with polycystic kidney disease Autosomal dominant disorder Symptoms may occur as a result of capsular stretch Cystadenoma Rare lesions with malignant potential Usually solitary multiloculated lesions Liver function tests usually normal Ultrasonography typically shows a large anechoic, fluid filled area with irregular margins. Internal echos may result from septa Surgical resection is indicated in all cases

Answer 1484

The optic canal transmits the optic nerve. The ophthalmic nerve traverses the superior orbital fissure. Foramina of the base of the skull Foramen Location Contents Foramen ovale Sphenoid bone Otic ganglion V3 (Mandibular nerve:3rd branch of trigeminal) Accessory meningeal artery Lesser petrosal nerve Emissary veins Foramen spinosum Sphenoid bone Middle meningeal artery Meningeal branch of the Mandibular nerve Foramen rotundum Sphenoid bone Maxillary nerve (V2) Foramen lacerum/ carotid canal Located between the sphenoid, the apex of the petrous temporal and the basilar part of the occipital Base of the medial pterygoid plate. Internal carotid artery* Nerve and artery of the pterygoid canal Jugular foramen Temporal bone Anterior: inferior petrosal sinus Intermediate: glossopharyngeal, vagus, and accessory nerves. Posterior: sigmoid sinus (becoming the internal jugular vein) and some meningeal branches from the occipital and ascending pharyngeal arteries. Foramen magnum Occipital bone Anterior and posterior spinal arteries Vertebral arteries Medulla oblongata Stylomastoid foramen Temporal bone Stylomastoid artery Facial nerve Superior orbital fissure Sphenoid bone Oculomotor nerve (III) Recurrent meningeal artery Trochlear nerve (IV) Lacrimal, frontal and nasociliary branches of opthalmic nerve (V1) Abducent nerve (VI) Superior ophthalmic vein *= In life the foramen lacerum is occluded by a cartilagenous plug. The ICA initially passes into the carotid canal which ascends superomedially to enter the cranial cavity through the foramen lacerum.

Answer 1485

Colorectal cancer is a major cause of iron deficiency anaemia and the colon is therefore investigated first before other differentials are considered. Lower Gastrointestinal bleeding Colonic bleeding This typically presents as bright red or dark red blood per rectum. Colonic bleeding rarely presents as malaena type stool, this is because blood in the colon has a powerful laxative effect and is rarely retained long enough for transformation to occur and because the digestive enzymes present in the small bowel are not present in the colon. Up to 15% of patients presenting with haemochezia will have an upper gastrointestinal source of haemorrhage. As a general rule right sided bleeds tend to present with darker coloured blood than left sided bleeds. Haemorrhoidal bleeding typically presents as bright red rectal bleeding that occurs post defecation either onto toilet paper or into the toilet pan. It is very unusual for haemorrhoids alone to cause any degree of haemodynamic compromise. Causes Cause Presenting features Colitis Bleeding may be brisk in advanced cases, diarrhoea is commonly present. Abdominal x-ray may show featureless colon. Diverticular disease Acute diverticulitis often is not complicated by major bleeding and diverticular bleeds often occur sporadically. 75% all will cease spontaneously within 24-48 hours. Bleeding is often dark and of large volume. Cancer Colonic cancers often bleed and for many patients this may be the first sign of the disease. Major bleeding from early lesions is uncommon Haemorrhoidal bleeding Typically bright red bleeding occurring post defecation. Although patients may give graphic descriptions bleeding of sufficient volume to cause haemodynamic compromise is rare. Angiodysplasia Apart from bleeding, which may be massive, these arteriovenous lesions cause little in the way of symptoms. The right side of the colon is more commonly affected. Management Prompt correction of any haemodynamic compromise is required. Unlike upper gastrointestinal bleeding the first line management is usually supportive. This is because in the acute setting endoscopy is rarely helpful. When haemorrhoidal bleeding is suspected a proctosigmoidoscopy is reasonable as attempts at full colonoscopy are usually time consuming and often futile. In the unstable patient the usual procedure would be an angiogram (either CT or percutaneous), when these are performed during a period of haemodynamic instability they may show a bleeding point and may be the only way of identifying a patch of angiodysplasia. In others who are more stable the standard procedure would be a colonoscopy in the elective setting. In patients undergoing angiography attempts can be made to address the lesion in question such as coiling. Otherwise surgery will be necessary. In patients with ulcerative colitis who have significant haemorrhage the standard approach would be a sub total colectomy, particularly if medical management has already been tried and is not effective. Indications for surgery Patients > 60 years Continued bleeding despite endoscopic intervention Recurrent bleeding Known cardiovascular disease with poor response to hypotension Surgery Selective mesenteric embolisation if life threatening bleeding. This is most helpful if conducted during a period of relative haemodynamic instability. If all haemodynamic parameters are normal then the bleeding is most likely to have stopped and any angiography normal in appearance. In many units a CT angiogram will replace selective angiography but the same caveats will apply. If the source of colonic bleeding is unclear; perform a laparotomy, on table colonic lavage and following this attempt a resection. A blind sub total colectomy is most unwise, for example bleeding from an small bowel arterio-venous malformation will not be treated by this manoeuvre. Summary of Acute Lower GI bleeding recommendations Consider admission if: * Over 60 years * Haemodynamically unstable/profuse PR bleeding * On aspirin or NSAID * Significant co morbidity Management All patients should have a history and examination, PR and proctoscopy Colonoscopic haemostasis aimed for in post polypectomy or diverticular bleeding References http://www.sign.ac.uk/guidelines/fulltext/105/index.html

Answer 1486

Overactive bladder syndrome is very common and first line management includes the use of anticholinergics and bladder drill whereby voiding is deferred. Refractory cases can be treated with SNS or botulinum toxin injections. A Burch Colposuspension is used to treat stress urinary incontinence. Urinary incontinence Involuntary passage of urine. Most cases are female (80%). It has a prevalence of 11% in those aged greater than 65 years. The commonest variants include: Stress urinary incontinence (50%) Urge incontinence (15%) Mixed (35%) Males Males may also suffer from incontinence although it is a much rarer condition in men. A number of anatomical factors contribute to this. Males have 2 powerful sphincters; one at the bladder neck and the other in the urethra. Damage to the bladder neck mechanism is a factor in causing retrograde ejaculation following prostatectomy. The short segment of urethra passing through the urogenital diaphragm consists of striated muscle fibres (the external urethral sphincter) and smooth muscle capable of more sustained contraction. It is the latter mechanism that maintains continence following prostatectomy. Females The sphincter complex at the level of bladder neck is poorly developed in females. As a result the external sphincter complex is functionally more important, its composition being similar to that of males. Innervation is via the pudendal nerve and the neuropathy that may accompany obstetric events may compromise this and lead to stress urinary incontinence. Innervation Somatic innervation to the bladder is via the pudendal, hypogastric and pelvic nerves. Autonomic nerves travel in these nerve fibres too. Bladder filling leads to detrusor relaxation (sympathetic) coupled with sphincter contraction. The parasympathetic system causes detrusor contraction and sphincter relaxation. Overall control of micturition is centrally mediated via centres in the Pons. Stress urinary incontinence 50% of cases, especially in females. Damage (often obstetric) to the supporting structures surrounding the bladder may lead to urethral hypermobility. Other cases due to sphincter dysfunction, usually from neurological disorders (e.g. Pudendal neuropathy, multiple sclerosis). Urethral mobility: Pressure not transmitted appropriately to the urethra resulting in involuntary passage of urine during episodes of raised intra-abdominal pressure. Sphincter dysfunction: Sphincter fails to adapt to compress urethra resulting in involuntary passage of urine. When the sphincter completely fails there is often to continuous passage of urine. Urge incontinence In these patients there is sense of urgency followed by incontinence. The detrusor muscle in these patients is unstable and urodynamic investigation will demonstrate overactivity of the detrusor muscle at inappropriate times (e.g. Bladder filling). Urgency may be seen in patients with overt neurological disorders and those without. The pathophysiology is not well understood but poor central and peripheral co-ordination of the events surrounding bladder filling are the main processes. Assessment Careful history and examination including vaginal examination for cystocele. Bladder diary for at least 3 days Consider flow cystometry if unclear symptomatology or surgery considered and diagnosis is unclear. Exclusion of other organic disease (e.g. Stones, UTI, Cancer) Management Conservative measures should be tried first; Stress urinary incontinence or mixed symptoms should undergo 3 months of pelvic floor exercise. Over active bladder should have 6 weeks of bladder retraining. Drug therapy for women with overactive bladder should be offered oxybutynin (or solifenacin if elderly) if conservative measures fail. In women with detrusor instability who fail non operative therapy a trial of sacral neuromodulation may be considered, with conversion to permanent implant if good response. Augmentation cystoplasty is an alternative but will involve long term intermittent self catheterisation. In women with stress urinary incontinence a urethral sling type procedure may be undertaken. Where cystocele is present in association with incontinence it should be repaired particularly if it lies at the introitus. NICE guidelines Initial assessment urinary incontinence should be classified as stress/urge/mixed. At least 3/7 bladder diary if unable to classify easily. Start conservative treatment before urodynamic studies if a diagnosis is obvious from the history Urodynamic studies if plans for surgery. Stress incontinence: Pelvic floor exercises 3/12, if fails consider surgery. Urge incontinence: Bladder training >6/52, if fails for oxybutynin (antimuscarinic drugs) then sacral nerve stimulation. Pelvic floor exercises offered to all women in their 1st pregnancy.

Answer 1487

Do not confuse the blood supply of the bile duct with that of the cystic duct. The bile duct has an axial blood supply which is derived from the hepatic artery and from retroduodenal branches of the gastroduodenal artery. Unlike the liver there is no contribution by the portal vein to the blood supply of the bile duct. Damage to the hepatic artery during a difficult cholecystectomy is a recognised cause of bile duct strictures. In this scenario the distal vessels have been removed as the patient is undergoing a resection. Gallbladder - Fibromuscular sac with capacity of 50ml Columnar epithelium Relations of the gallbladder Anterior Liver Posterior Covered by peritoneum Transverse colon 1st part of the duodenum Laterally Right lobe of liver Medially Quadrate lobe of liver Arterial supply Cystic artery (branch of Right hepatic artery) Venous drainage Directly to the liver Nerve supply Sympathetic- mid thoracic spinal cord, Parasympathetic- anterior vagal trunk Common bile duct Origin Confluence of cystic and common hepatic ducts Relations at origin Medially - Hepatic artery Posteriorly- Portal vein Relations distally Duodenum - anteriorly Pancreas - medially and laterally Right renal vein - posteriorly Arterial supply Branches of hepatic artery and retroduodenal branches of gastroduodenal artery Hepatobiliary triangle Medially Common hepatic duct Inferiorly Cystic duct Superiorly Inferior edge of liver Contents Cystic artery

Answer 1488

The hyperventilation results in decreased carbon dioxide levels, causing a respiratory alkalosis (non compensated). Metabolic acidosis This is the most common surgical acid - base disorder. Reduction in plasma bicarbonate levels. Two mechanisms: 1. Gain of strong acid (e.g. diabetic ketoacidosis) 2. Loss of base (e.g. from bowel in diarrhoea) - Classified according to the anion gap, this can be calculated by: (Na+ + K+) - (Cl- + HCO3-). - If a question supplies the chloride level then this is often a clue that the anion gap should be calculated. The normal range = 10-18 mmol/L Normal anion gap ( = hyperchloraemic metabolic acidosis) Gastrointestinal bicarbonate loss: diarrhoea, ureterosigmoidostomy, fistula Renal tubular acidosis Drugs: e.g. acetazolamide Ammonium chloride injection Addison's disease Raised anion gap Lactate: shock, hypoxia Ketones: diabetic ketoacidosis, alcohol Urate: renal failure Acid poisoning: salicylates, methanol Metabolic acidosis secondary to high lactate levels may be subdivided into two types: Lactic acidosis type A: (Perfusion disorders e.g.shock, hypoxia, burns) Lactic acidosis type B: (Metabolic e.g. metformin toxicity) Metabolic alkalosis Usually caused by a rise in plasma bicarbonate levels. Rise of bicarbonate above 24 mmol/L will typically result in renal excretion of excess bicarbonate. Caused by a loss of hydrogen ions or a gain of bicarbonate. It is due mainly to problems of the kidney or gastrointestinal tract Causes Vomiting / aspiration (e.g. Peptic ulcer leading to pyloric stenosis, nasogastric suction) Diuretics Liquorice, carbenoxolone Hypokalaemia Primary hyperaldosteronism Cushing's syndrome Bartter's syndrome Congenital adrenal hyperplasia Mechanism of metabolic alkalosis Activation of renin-angiotensin II-aldosterone (RAA) system is a key factor Aldosterone causes reabsorption of Na+ in exchange for H+ in the distal convoluted tubule ECF depletion (vomiting, diuretics) → Na+ and Cl- loss → activation of RAA system → raised aldosterone levels In hypokalaemia, K+ shift from cells → ECF, alkalosis is caused by shift of H+ into cells to maintain neutrality Respiratory acidosis Rise in carbon dioxide levels usually as a result of alveolar hypoventilation Renal compensation may occur leading to Compensated respiratory acidosis Causes COPD Decompensation in other respiratory conditions e.g. Life-threatening asthma / pulmonary oedema Sedative drugs: benzodiazepines, opiate overdose Respiratory alkalosis Hyperventilation resulting in excess loss of carbon dioxide This will result in increasing pH Causes Psychogenic: anxiety leading to hyperventilation Hypoxia causing a subsequent hyperventilation: pulmonary embolism, high altitude Early salicylate poisoning* CNS stimulation: stroke, subarachnoid haemorrhage, encephalitis Pregnancy *Salicylate overdose leads to a mixed respiratory alkalosis and metabolic acidosis. Early stimulation of the respiratory centre leads to a respiratory alkalosis whilst later the direct acid effects of salicylates (combined with acute renal failure) may lead to an acidosis

Answer 1489

The full thickness burn has oedema which is affecting the peripheral circulation. Therefore the burn needs to be divided (not the fascia) to allow normal circulation to return. Burns Burns may be thermal, chemical or electrical. In the former category are burns which occur as a result of heat. Chemical burns occur when the skin is exposed to an extremely caustic or alkaline substance. Electrical burns occur following exposure to electrical current. The immediate management includes removal of the burning source which usually includes irrigation of the burned area. A detailed assessment then needs to be made of the extent of the burns and a number of charts are available for recording this information. The degree of injury relates to the temperature and duration of exposure. Most domestic burns are mainly scalds in young children. Following the burn, there is a local response with progressive tissue loss and release of inflammatory cytokines. Systemically, there are cardiovascular effects resulting from fluid loss and sequestration of fluid into the third space. There is a marked catabolic response. Immunosuppression is common with large burns and bacterial translocation from the gut lumen is a recognised event. Sepsis is a common cause of death following major burns. Types of burn Type of burn Skin layers affected Skin appearance Blanching Management Epidermal/Superficial Epidermis Red, moist Yes Superficial partial thickness Epidermis and part of papillary dermis affected Pale, dry Yes Normally heals with no intervention Deep partial thickness Epidermis, whole papillary dermis affected Mottled red colour No Needs surgical intervention (depending on site) Full thickness Whole skin layer and subcutaneous tissue affected Dry, leathery hard wound No Burns centre Depth of burn assessment Bleeding on needle prick Sensation Appearance Blanching to pressure Percentage burn estimation Lund Browder chart: most accurate even in children Wallace rule of nines Palmar surface: surface area palm = 0.8% burn >15% body surface area burns in adults needs urgent burn fluid resuscitation Transfer to burn centre if: Need burn shock resuscitation Face/hands/genitals affected Deep partial thickness or full thickness burns Significant electrical/chemical burns Management The initial aim is to stop the burning process and resuscitate the patient. Intravenous fluids will be required for children with burns greater than 10% of total body surface area. Adults with burns greater than 15% of total body surface area will also require IV fluids. The fluids are calculated using the Parkland formula which is; volume of fluid= total body surface area of the burn % x weight (Kg) x2-4 (preference for lower amount i.e. 2ml to avoid excessive fluid overload). Half of the fluid is administered in the first 8 hours. A urinary catheter should be inserted. Analgesia should be given. Complex burns, burns involving the hand perineum and face and burns >10% in adults and >5% in children should be transferred to a burns unit. Circumferential burns affecting a limb or severe torso burns impeding respiration may require escharotomy to divide the burnt tissue. Conservative management is appropriate for superficial burns and mixed superficial burns that will heal in 2 weeks. More complex burns may require excision and skin grafting. Excision and primary closure is not generally practised as there is a high risk of infection. There is no evidence to support the use of anti microbial prophylaxis or topical antibiotics in burn patients. Escharotomies Indicated in circumferential full thickness burns to the torso or limbs. Careful division of the encasing band of burn tissue will potentially improve ventilation (if the burn involves the torso), or relieve compartment syndrome and oedema (where a limb is involved) References www.euroburn.org/e107files/downloads/guidelinesburncare.pdf Barajas-Nava LA, LÃ³pez-Alcalde J, RoquÃ© i Figuls M, SolÃ I, Bonfill Cosp X. Antibiotic prophylaxis for preventing burn wound infection. Cochrane Database of Systematic Reviews 2013, Issue 6. Art. No.: CD008738. DOI: 10.1002/14651858.CD008738.pub2. Hettiaratchy S & Papini R. Initial management of a major burn: assessment and resuscitation. BMJ 2004;329:101-103

Answer 1490

Blood film in hyposplenism: Howell-Jolly bodies Pappenheimer bodies Poikilocytes (Target cells) Erythrocyte containing siderotic granules Heinz bodies Splenectomy Indications Trauma: 1/4 are iatrogenic Spontaneous rupture: EBV Hypersplenism: hereditary spherocytosis or elliptocytosis etc Malignancy: lymphoma or leukaemia Splenic cysts, hydatid cysts, splenic abscesses Splenectomy Technique Trauma GA Long midline incision If time permits insert a self retaining retractor (e.g. Balfour/ omnitract) Large amount of free blood is usually present. Pack all 4 quadrants of the abdomen. Allow the anaesthetist to 'catch up' Remove the packs and assess the viability of the spleen. Hilar injuries and extensive parenchymal lacerations will usually require splenectomy. Divide the short gastric vessels and ligate them. Clamp the splenic artery and vein. Two clamps on the patient side are better and allow for double ligation and serve as a safety net if your assistant does not release the clamp smoothly. Be careful not to damage the tail of the pancreas, if you do then this will need to be formally removed and the pancreatic duct closed. Wash out the abdomen and place a tube drain to the splenic bed. Some surgeons implant a portion of spleen into the omentum, whether you decide to do this is a matter of personal choice. Post operatively the patient will require prophylactic penicillin V and pneumococcal vaccine. Elective Elective splenectomy is a very different operation from that performed in the emergency setting. The spleen is often large (sometimes massive). Most cases can be performed laparoscopically. The spleen will often be macerated inside a specimen bag to facilitate extraction. Complications Haemorrhage (may be early and either from short gastrics or splenic hilar vessels Pancreatic fistula (from iatrogenic damage to pancreatic tail) Thrombocytosis: prophylactic aspirin Encapsulated bacteria infection e.g. Strep. pneumoniae, Haemophilus influenzae and Neisseria meningitidis Post splenectomy changes Platelets will rise first (therefore in ITP should be given after splenic artery clamped) Blood film will change over following weeks, Howell Jolly bodies will appear Other blood film changes include target cells and Pappenheimer bodies Increased risk of post splenectomy sepsis, therefore prophylactic antibiotics and pneumococcal vaccine should be given. Post splenectomy sepsis Typically occurs with encapsulated organisms Opsonisation occurs but then not recognised

Answer 1491

An obese, post menopausal woman, with a history of trauma points towards fat necrosis. Trauma causes inflammation of fat cells, leading to formation of a lump. Mammography, USS and biopsy are usually needed to differentiate it from breast malignancy. Benign breast lesions Lesion Features Treatment Fibroadenoma Develop from a whole lobule Mobile, firm breast lumps 12% of all breast masses Over a 2 year period up to 30% will get smaller No increase in risk of malignancy If >3cm surgical excision is usual, Phyllodes tumours should be widely excised (mastectomy if the lesion is large) Breast cyst 7% of all Western females will present with a breast cyst Usually presents as a smooth discrete lump (may be fluctuant) Small increased risk of breast cancer (especially if younger) Cysts should be aspirated, those which are blood stained or persistently refill should be biopsied or excised Sclerosing adenosis, (radial scars and complex sclerosing lesions) Usually presents as a breast lump or breast pain Causes mammographic changes which may mimic carcinoma Cause distortion of the distal lobular unit, without hyperplasia (complex lesions will show hyperplasia) Considered a disorder of involution, no increase in malignancy risk Lesions should be biopsied, excision is not mandatory Epithelial hyperplasia Variable clinical presentation ranging from generalised lumpiness through to discrete lump Disorder consists of increased cellularity of terminal lobular unit, atypical features may be present Atypical features and family history of breast cancer confers greatly increased risk of malignancy If no atypical features then conservative, those with atypical features require either close monitoring or surgical resection Fat necrosis Up to 40% cases usually have a traumatic aetiology Physical features usually mimic carcinoma Mass may increase in size initially Imaging and core biopsy Duct papilloma Usually present with nipple discharge Large papillomas may present with a mass The discharge usually originates from a single duct No increase risk of malignancy

Answer 1492

Pre auricular sinuses that are deeper may accumulate secretions and produce foul smelling discharge. Disorders affecting the ear Otitis externa Variant Cause Features Treatment Acute otitis externa Boil in external auditory meatus Acute pain on moving the pinna Conductive hearing loss if lesion is large When rupture occurs pus will flow from ear Ear packs may be used Topical antibiotics Operative debridement may be needed in severe cases Chronic otitis externa Chronic combined infection in the external auditory meatus usually combined staphylococcal and fungal infection Chronic discharge from affected ear, hearing loss and severe pain rare Cleansing of the external ear and treatment with antifungal and antibacterial ear drops Otitis media Variant Cause Features Treatment Acute suppurative otitis media Viral induced middle ear effusions secondary to eustacian tube dysfunction Most common in children and rare in adults May present with symptoms elsewhere (e.g. vomiting) in children Severe pain and sometimes fever May present with discharge if tympanic rupture occurs Antibiotics (usually amoxycillin) Chronic suppurative otitis media May occur with or without cholesteatoma Those without cholesteatoma have a perforation of the pars tensa Those with cholesteatoma have a perforation of the pars flaccida Those without cholesteatoma may complain of intermittent discharge (non offensive) Those with cholesteatoma have impaired hearing and foul smelling discharge Simple pars tensa perforations may be managed non operatively or a myringoplasty considered if symptoms troublesome. Pars flaccida perforations will usually require a modified radical mastoidectomy Otosclerosis Progressive conductive deafness Secondary to fixation of the stapes in the oval window Treatment is with stapedectomy and insertion of a prosthesis Acoustic neuroma Symptoms of gradually progressive unilateral perceptive deafness and tinnitus Involvement of the vestibular nerve may cause vertigo Extension to involve the facial nerve may cause weakness and then paralysis. Pre auricular sinus Common congenital condition in which an epithelial defect forms around the external ear Small sinuses require no treatment Deeper sinuses may become blocked and develop episodes of infection, they may be closely related to the facial nerve and are challenging to excise

Answer 1493

The rectus sheath also contains: superior epigastric vein inferior epigastric artery Abdominal wall The 2 main muscles of the abdominal wall are the rectus abdominis (anterior) and the quadratus lumborum (posterior). The remaining abdominal wall consists of 3 muscular layers. Each muscle passes from the lateral aspect of the quadratus lumborum posteriorly to the lateral margin of the rectus sheath anteriorly. Each layer is muscular posterolaterally and aponeurotic anteriorly. Muscles of abdominal wall External oblique Lies most superficially Originates from 5th to 12th ribs Inserts into the anterior half of the outer aspect of the iliac crest, linea alba and pubic tubercle More medially and superiorly to the arcuate line, the aponeurotic layer overlaps the rectus abdominis muscle The lower border forms the inguinal ligament The triangular expansion of the medial end of the inguinal ligament is the lacunar ligament. Internal oblique Arises from the thoracolumbar fascia, the anterior 2/3 of the iliac crest and the lateral 2/3 of the inguinal ligament The muscle sweeps upwards to insert into the cartilages of the lower 3 ribs The lower fibres form an aponeurosis that runs from the tenth costal cartilage to the body of the pubis At its lowermost aspect it joins the fibres of the aponeurosis of transversus abdominis to form the conjoint tendon. Transversus abdominis Innermost muscle Arises from the inner aspect of the costal cartilages of the lower 6 ribs , from the anterior 2/3 of the iliac crest and lateral 1/3 of the inguinal ligament Its fibres run horizontally around the abdominal wall ending in an aponeurosis. The upper part runs posterior to the rectus abdominis. Lower down the fibres run anteriorly only. The rectus abdominis lies medially; running from the pubic crest and symphysis to insert into the xiphoid process and 5th, 6th and 7th costal cartilages. The muscles lies in a aponeurosis as described above. Nerve supply: anterior primary rami of T7-12 Surgical notes During abdominal surgery it is usually necessary to divide either the muscles or their aponeuroses. During a midline laparotomy it is desirable to divide the aponeurosis. This will leave the rectus sheath intact above the arcuate line and the muscles intact below it. Straying off the midline will often lead to damage to the rectus muscles, particularly below the arcuate line where they may often be in close proximity to each other.

Answer 1494

D-I-S-S-E-M-I-N-A-T-E-D D-Dx: D dimer I-Immune complexes S-Snakebite, shock, heatstroke S-SLE E-Eclampsia, HELLP syndrome M-Massive tissue damage I-Infections: viral and bacterial N-Neoplasms A-Acute promyelocytic leukemia T-Tumor products: Tissue Factor (TF) and TF-like factors released by carcinomas of pancreas, prostate, lung, colon, stomach E-Endotoxins (bacterial) D-Dead fetus (retained) DIC Will tend to consume factors five and eight intially (and platelets). Disseminated intravascular coagulation Simultaneous coagulation and haemorrhage caused by initially formation of thrombi which consume clotting factors (factors 5,8) and platelets, ultimately leading to bleeding Causes include: Infection Malignancy Trauma e.g. major surgery, burns, shock, dissecting aortic aneurysm Liver disease Obstetric complications Key points Clinically bleeding is usually a dominant feature, bruising, ischaemia and organ failure Blood tests: prolonged clotting times, thrombocytopenia, decreased fibrinogen, increased fibrinogen degradation products Treat the underlying cause and supportive management

Answer 1495

Upper motor neurone lesions of the facial nerve- Paralysis of the lower half of face. Lower motor neurone lesion- Paralysis of the entire ipsilateral face. Upper Vs Lower motor neurone lesions - Facial nerve The nucleus of the facial nerve is located in the caudal aspect of the ventrolateral pontine tegmentum. Its axons exit the ventral pons medial to the spinal trigeminal nucleus. Any lesion occurring within or affecting the corticobulbar tract is known as an upper motor neuron lesion. Any lesion affecting the individual branches (temporal, zygomatic, buccal, mandibular and cervical) is known as a lower motor neuron lesion. Branches of the facial nerve leaving the facial motor nucleus (FMN) for the muscles do so via both left and right posterior (dorsal) and anterior (ventral) routes. In other words, this means lower motor neurons of the facial nerve can leave either from the left anterior, left posterior, right anterior or right posterior facial motor nucleus. The temporal branch travels out from the left and right posterior components. The inferior four branches do so via the left and right anterior components. The left and right branches supply their respective sides of the face (ipsilateral innervation). Accordingly, the posterior components receive motor input from both hemispheres of the cerebral cortex (bilaterally), whereas the anterior components receive strictly contra-lateral input. This means that the temporal branch of the facial nerve receives motor input from both hemispheres of the cerebral cortex whereas the zygomatic, buccal, mandibular and cervical branches receive information from only contralateral hemispheres. Now, because the anterior FMN receives only contralateral cortical input whereas the posterior receives that which is bilateral, a corticobulbar lesion (UMN lesion) occurring in the left hemisphere would eliminate motor input to the right anterior FMN component, thus removing signaling to the inferior four facial nerve branches, thereby paralyzing the right mid- and lower-face. The posterior component, however, although now only receiving input from the right hemisphere, is still able to allow the temporal branch to sufficiently innervate the entire forehead. This means that the forehead will not be paralyzed. The same mechanism applies for an upper motor neuron lesion in the right hemisphere. The left anterior FMN component no longer receives cortical motor input due to its strict contralateral innervation, whereas the posterior component is still sufficiently supplied by the left hemisphere. The result is paralysis of the left mid- and lower-face with an unaffected forehead. On the other hand, a lower motor neuron lesion is a bit different. A lesion on either the left or right side would affect both the anterior and posterior routes on that side because of their close physical proximity to one another. So, a lesion on the left side would inhibit muscle innervation from both the left posterior and anterior routes, thus paralyzing the whole left side of the face (Bells Palsy). With this type of lesion, the bilateral and contalateral inputs of the posterior and anterior routes, respectively, become irrelevant because the lesion is below the level of the medulla and the facial motor nucleus. Whereas at a level above the medulla a lesion occurring in one hemisphere would mean that the other hemisphere could still sufficiently innervate the posterior facial motor nucleus, a lesion affecting a lower motor neuron would eliminate innervation altogether because the nerves no longer have a means to receive compensatory contralateral input at a downstream decussation.

Answer 1496

Ferritin can be markedly increased during acute illness. The other parameters tend to decrease during an acute phase response. Acute phase proteins Acute phase proteins CRP procalcitonin ferritin fibrinogen alpha-1 antitrypsin caeruloplasmin serum amyloid A haptoglobin complement During the acute phase response the liver decreases the production of other proteins (sometimes referred to as negative acute phase proteins). Examples include: albumin transthyretin (formerly known as prealbumin) transferrin retinol binding protein cortisol binding protein Levels of CRP are commonly measured in acutely unwell patients. CRP is a protein synthesised in the liver and binds to phosphocholine in bacterial cells and on those cells undergoing apoptosis. In binding to these cells it is then able to activate the complement system. CRP levels are known to rise in patients following surgery. However, levels of greater than 150 at 48 hours post operatively are suggestive of evolving complications.

Answer 1497

Hepatocellular carcinoma is commonly diagnosed with imaging and an elevated alpha fetoprotein. Biopsy may seed the tumour and should be avoided. Up to 80% of hepatocellular carcinoma arise in cirrhotic livers. Liver tumours Primary liver tumours The most common primary tumours are cholangiocarcinoma and hepatocellular carcinoma. Overall metastatic disease accounts for 95% of all liver malignancies making the primary liver tumours comparatively rare. Primary liver tumours include: Cholangiocarcinoma Hepatocellular carcinoma Hepatoblastoma Sarcomas (Rare) Lymphomas Carcinoids (most often secondary although primary may occur) Hepatocellular carcinoma These account for the bulk of primary liver tumours (75% cases). Its worldwide incidence reflects its propensity to occur on a background of chronic inflammatory activity. Most cases arise in cirrhotic livers or those with chronic hepatitis B infection, especially where viral replication is actively occurring. In the UK it accounts for less than 5% of all cancers, although in parts of Asia its incidence is 100 per 100,000. The majority of patients (80%) present with existing liver cirrhosis, with a mass discovered on screening ultrasound. Diagnosis CT/ MRI (usually both) are the imaging modalities of choice a-fetoprotein is elevated in almost all cases Biopsy should be avoided as it seeds tumours cells through a resection plane. In cases of diagnostic doubt serial CT and αFP measurements are the preferred strategy. Treatment Patients should be staged with liver MRI and chest, abdomen and pelvic CT scan. The testis should be examined in males (testicular tumours may cause raised AFP). PET CT may be used to identify occult nodal disease. Surgical resection is the mainstay of treatment in operable cases. In patients with a small primary tumour in a cirrhotic liver whose primary disease process is controlled, consideration may be given to primary whole liver resection and transplantation. Liver resections are an option but since most cases occur in an already diseased liver the operative risks and post-operative hepatic dysfunction are far greater than is seen following metastectomy. These tumours are not particularly chemo or radiosensitive however, both may be used in a palliative setting. Tumour ablation is a more popular strategy. Survival Poor, overall survival is 15% at 5 years. Cholangiocarcinoma This is the second most common type of primary liver malignancy. As its name suggests these tumours arise in the bile ducts. Up to 80% of tumours arise in the extra hepatic biliary tree. Most patients present with jaundice and by this stage the majority will have disease that is not resectable. Primary sclerosing cholangitis is the main risk factor. In deprived countries typhoid and liver flukes are also major risk factors. Diagnosis Patients will typically have an obstructive picture on liver function tests. CA 19-9, CEA and CA 125 are often elevated CT/ MRI and MRCP are the imaging methods of choice. Treatment Surgical resection offers the best chance of cure. Local invasion of peri hilar tumours is a particular problem and this coupled with lobar atrophy will often contra indicate surgical resection. Palliation of jaundice is important, although metallic stents should be avoided in those considered for resection. Survival Is poor, approximately 5-10% 5 year survival.

Answer 1498

Gastroschisis: Isolated abnormality, bowel lies outside abdominal wall through defect located to right of umbilicus. Exomphalos: Liver and gut remain covered with membranous sac connected to umbilical cord. It is associated with other developmental defects. They are contained within the peritoneal sac and therefore do not have the fluid losses seen in gastroschisis. True malrotation is unusual and minor variants may not result in a requirement for surgery. Paediatric Gastrointestinal disorders Pyloric stenosis M>F 5-10% Family history in parents Projectile non bile stained vomiting at 4-6 weeks of life Diagnosis is made by test feed or USS Treatment: Ramstedt pyloromyotomy (open or laparoscopic) Acute appendicitis Uncommon under 3 years When occurs may present atypically Mesenteric adenitis Central abdominal pain and URTI Conservative management Intussusception Telescoping bowel Proximal to or at the level of, ileocaecal valve 6-9 months age Colicky pain, diarrhoea and vomiting, sausage shaped mass, red jelly stool. Treatment: reduction with air insufflation Malrotation High caecum at the midline Feature in exomphalos, congenital diaphragmatic hernia, intrinsic duodenal atresia May be complicated by development of volvulus, infant with volvulus may have bile stained vomiting Diagnosis is made by upper GI contrast study and USS Treatment is by laparotomy, if volvulus is present (or at high risk of occurring then a ladds procedure is performed Hirschsprung's disease Absence of ganglion cells from myenteric and submucosal plexuses Occurs in 1/5000 births Full thickness rectal biopsy for diagnosis Delayed passage of meconium and abdominal distension Treatment is with rectal washouts initially, thereafter an anorectal pull through procedure Oesophageal atresia Associated with tracheo-oesophageal fistula and polyhydramnios May present with choking and cyanotic spells following aspiration VACTERL associations Meconium ileus Usually delayed passage of meconium and abdominal distension Majority have cystic fibrosis X-Rays may not show a fluid level as the meconium is viscid (depends upon feeding), PR contrast studies may dislodge meconium plugs and be therapeutic Infants who do not respond to PR contrast and NG N-acetyl cysteine will require surgery to remove the plugs Biliary atresia Jaundice > 14 days Increased conjugated bilirubin Urgent Kasai procedure Necrotising enterocolitis Prematurity is the main risk factor Early features include abdominal distension and passage of bloody stools X-Rays may show pneumatosis intestinalis and evidence of free air Increased risk when empirical antibiotics are given to infants beyond 5 days Treatment is with total gut rest and TPN, babies with perforations will require laparotomy

Answer 1499

He has necrotising enterocolitis and whilst this is often initially managed medically, a laparotomy is required if the situation deteriorates. Paediatric Gastrointestinal disorders Pyloric stenosis M>F 5-10% Family history in parents Projectile non bile stained vomiting at 4-6 weeks of life Diagnosis is made by test feed or USS Treatment: Ramstedt pyloromyotomy (open or laparoscopic) Acute appendicitis Uncommon under 3 years When occurs may present atypically Mesenteric adenitis Central abdominal pain and URTI Conservative management Intussusception Telescoping bowel Proximal to or at the level of, ileocaecal valve 6-9 months age Colicky pain, diarrhoea and vomiting, sausage shaped mass, red jelly stool. Treatment: reduction with air insufflation Malrotation High caecum at the midline Feature in exomphalos, congenital diaphragmatic hernia, intrinsic duodenal atresia May be complicated by development of volvulus, infant with volvulus may have bile stained vomiting Diagnosis is made by upper GI contrast study and USS Treatment is by laparotomy, if volvulus is present (or at high risk of occurring then a ladds procedure is performed Hirschsprung's disease Absence of ganglion cells from myenteric and submucosal plexuses Occurs in 1/5000 births Full thickness rectal biopsy for diagnosis Delayed passage of meconium and abdominal distension Treatment is with rectal washouts initially, thereafter an anorectal pull through procedure Oesophageal atresia Associated with tracheo-oesophageal fistula and polyhydramnios May present with choking and cyanotic spells following aspiration VACTERL associations Meconium ileus Usually delayed passage of meconium and abdominal distension Majority have cystic fibrosis X-Rays may not show a fluid level as the meconium is viscid (depends upon feeding), PR contrast studies may dislodge meconium plugs and be therapeutic Infants who do not respond to PR contrast and NG N-acetyl cysteine will require surgery to remove the plugs Biliary atresia Jaundice > 14 days Increased conjugated bilirubin Urgent Kasai procedure Necrotising enterocolitis Prematurity is the main risk factor Early features include abdominal distension and passage of bloody stools X-Rays may show pneumatosis intestinalis and evidence of free air Increased risk when empirical antibiotics are given to infants beyond 5 days Treatment is with total gut rest and TPN, babies with perforations will require laparotomy

Answer 1500

This is the most common organism affecting previously abnormal heart valves. Surgical Microbiology An extensive topic so an overview is given here. Organisms causing common surgical infections are reasonable topics in the examination. However, microbiology is less rigorously tested than anatomy, for example. Common organisms Staphylococcus aureus Facultative anaerobe Gram positive coccus Haemolysis on blood agar plates Catalase positive 20% population are long term carriers Exo and entero toxin may result in toxic shock syndrome and gastroenteritis respectively Ideally treated with penicillin although many strains now resistant through beta Lactamase production. In the UK less than 5% of isolates are sensitive to penicillin. Resistance to methicillin (and other antibiotics) is mediated by the mec operon , essentially penicillin binding protein is altered and resistance to this class of antibiotics ensues Common cause of cutaneous infections and abscesses Streptococcus pyogenes Gram positive, forms chain like colonies, Lancefield Group A Streptococcus Produces beta haemolysis on blood agar plates Rarely part of normal skin microflora Catalase negative Releases a number of proteins/ virulence factors into host including hyaluronidase, streptokinase which allow rapid tissue destruction Releases superantigens such as pyogenic exotoxin A which results in scarlet fever Remains sensitive to penicillin, macrolides may be used as an alternative. Escherichia coli Gram negative rod Facultative anaerobe, non sporing Wide range of subtypes and some are normal gut commensals Some subtypes such as 0157 may produce lethal toxins resulting in haemolytic-uraemic syndrome Enterotoxigenic E-Coli produces an enterotoxin (ST enterotoxin) that results in large volume fluid secretion into the gut lumen (Via cGMP activation) Enteropathogenic E-Coli binds to intestinal cells and cause structural damage, this coupled with a moderate (or in case of enteroinvasive E-Coli significant) invasive component produces enteritis and large volume diarrhoea together with fever. They are resistant to many antibiotics used to treat gram positive infections and acquire resistance rapidly and are recognised as producing beta lactamases Campylobacter jejuni Curved, gram negative, non sporulating bacteria One of the commonest causes of diarrhoea worldwide Produces enteritis which is often diffuse and blood may be passed Remains a differential for right iliac fossa pain with diarrhoea Self limiting infection so antibiotics are not usually advised. However, the quinolones are often rapidly effective. Helicobacter pylori Gram negative, helix shaped rod, microaerophillic Produces hydrogenase that can derive energy from hydrogen released by intestinal bacteria Flagellated and mobile Those carrying the cag A gene may cause ulcers It secretes urease that breaks down gastric urea> Carbon dioxide and ammonia> ammonium>bicarbonate (simplified!) The bicarbonate can neutralise the gastric acid. Usually colonises the gastric antrum and irritates resulting in increased gastrin release and higher levels of gastric acid. These patients will develop duodenal ulcers. In those with more diffuse H-Pylori infection gastric acid levels are lower and ulcers develop by local tissue damage from H-Pylori- these patients get gastric ulcers. Diagnosis may be made by serology (approx. 75% sensitive). Biopsy urease test during endoscopy probably the most sensitive. In patients who are colonised 10-20% risk of peptic ulcer, 1-2% risk gastric cancer, <1% risk MALT lymphoma.

Answer 1501

An arterial duplex should be performed first, before progression to an angiography. Vascular investigations Venous disease Venous Doppler The simplest investigation for assessment of venous junctional incompetence is a Doppler assessment. This involves the patient standing and manual compression of the limb distal to the junction of interest. Flow should normally occur in one direction only. Where junctional incompetence is present reverse flow will occur and is relatively easy to identify. Venograms and duplex scans Structural venous information is historically obtained using a venogram. This is an invasive test and rarely required in modern clinical practice. The most helpful test is a venous duplex scan which will provide information relating to flow and vessel characteristics. Duplex is also useful in providing vein maps for bypass surgery. Arterial disease Ankle-brachial pressure The ankle brachial pressure index measurement is an important investigation as it will allow classification of the severity of the flow compromise present. False readings may occur in those with calcified vessels such as diabetics and results in such settings should be interpreted with caution. When auscultating the vessel note should be made of the character of the signal. Monophasic signals are associated with a proximal stenosis and reduction in flow. Triphasic signals provide reassurance of a healthy vessel. Arterial Duplex As with the vein the duplex scan can provide a substantial amount of information about arterial patency and flow patterns. In skilled hands they can provide insight as to the state of proximal vessels that are anatomically inaccessible to duplex (e.g. Iliacs). Through assessment of distal flow patterns. It is an operator dependent test. Conventional angiogram Vessel puncture and catheter angiography is the gold standard method of assessing arteries. High quality information can usually be obtained. Limitations of the technique include the risk of contrast toxicity and risks of vessel damage. Severely calcified vessels may be difficult to puncture and in this situation a remote access site (e.g. brachial) may be used. This technique is particularly useful in providing a distal arterial roadmap prior to femoro-distal bypass. CT angiography These tests provide a considerable amount of structural and flow information. They require contrast and thus carry the risks associated with this. They are particularly useful in the setting of GI bleeding as they are rapidly available and can be performed by a non vascular radiologist. However, they lack the facility for endovascular intervention. In general they do not provide high enough resolution for distal arterial surgery. Magnetic resonance angiography This has the advantage of being non-invasive and not using nephrotoxic contrast. Movement artifact remains a problem in some sites and distal arterial resolution is imperfect.

Answer 1502

This is an unstable fracture pattern with a Weber B fracture of the distal fibula and a fracture of the medial malleolus. Talar shift indicates loss of ankle mortice congruity. This injury should therefore be treated with surgical fixation. Ankle injuries An ankle fracture relates to a fracture around the tibio-talar joint. It generally refers to a fracture involving the lateral, and/or medial and/or posterior malleolus. Pilon and Tillaux fractures are also considered to be ankle fractures, but are not covered here. Ankle fractures are common. They effect men and women in equal numbers, but men have a higher rate as young adults (sports and contact injuries), and women a higher rate post-menopausal (fragility type fracture). Osseous anatomy The ankle (or mortise) joint consists of the distal tibia (tibial plafond and posterior malleolus), the distal fibula (lateral malleolus), and the talus. The main movement at the ankle joint is plantar and dorsiflexion. Ligamentous anatomy Medial side: Deltoid ligament. This is divided into superficial and deep portions. It is the primary restraint to valgus tilting of the talus. Lateral side: Lateral ligament complex consisting from anterior to posterior of the anterior talofibular ligament (ATFL), calcaneofibular ligament (CFL), and the posterior talofibular ligament (PTFL). Together they resist valgus stress to the ankle, and are a restraint to anterior translation of the talus within the mortise joint. Syndesmosis: The syndesmosis is a ligament complex between the distal tibia and fibula, holding the two bones together. It is fundamental to the integrity of the ankle joint, and its disruption leads to instability. It consists of (from anterior to posterior) the anterior-inferior tibiofibular ligament (AITFL), the transverse tibiofibular ligament (TTFL), the interosseous membrane, and the posterior-inferior tibiofibular ligament (PITFL). Presentation and initial management Patients will present following a traumatic event with a painful, swollen ankle, and reluctance/inability to weight bear. The Ottawa rules can be applied to differentiate between an ankle fracture and sprain, but can be unreliable. In high energy injuries, management should follow ATLS principles to identify more significant injuries first. Neurovascular status of the foot should be documented, and open injuries should be excluded. If an open injury is identified, it should be managed in line with BOAST 4 principles1. If an obvious deformity exists, it should be reduced as soon as possible with appropriate analgesia or conscious sedation. Radiographs of clearly deformed or dislocated joints are not necessary, and removing the pressure on the surrounding soft tissues from the underlying bony deformity is the priority. If the fracture pattern is not clinically obvious then plain radiographs are appropriate and will guide the subsequent manipulation during plaster-of-paris below knee backslab application. Imaging AP, lateral and mortise views (20 degrees internal rotation) are essential to evaluate fracture displacement and syndesmotic injury. Decreased tibiofibular overlap, medial joint clear space and lateral talar shift all indicate a syndesmotic injury. (In subtle cases of shift, imaging the uninjured ankle can be helpful as a proportion of the population have little or no tibiotalar overlap-reference 2.) Where there is suspicion of syndesmosis involvement in the absence of radiographic evidence, stress radiographs can be diagnostic. Complex fracture patterns (and increasingly posterior malleolar fractures) are best defined using CT. Classification The most commonly used classifications are Lauge-Hansen and Danis-Weber. Lauge-Hansen Comprises two parts: first part is the foot position, and the second part is the force applied. Useful for understanding the forces involved and therefore predict the ligamentous or bony injury. Results in four injury patterns: Supination - Adduction (SA) - 10-20% Supination - External rotation (SER) - 40-75% Pronation - Abduction (PA) - 5-20% Pronation - External rotation (PER) - 5-20% Not often used in clinical practice but good for understanding the principles of ankle fracture. Danis-Weber Commonly used. Based on the level of the fibula fracture in relation to the syndesmosis. The more proximal, the greater the risk of syndesmotic injury and therefore fracture instability. A - fracture below the level of the syndesmosis B - fracture at the level of the syndesmosis / level of the tibial plafond C - fracture above the level of the syndesmosis. This includes Maisonneuve fractures (proximal fibula fracture), which can be associated with ankle instability. Beware the high fibula fracture - it may be an ankle fracture! The Weber classification is based purely on the the lateral side. All injuries can include a medial or posterior bony or ligamentous injury which also dictates fracture stability (bimalleolar and trimalleolar fractures are more unstable). Treatment When deciding upon treatment for an ankle fracture, one must consider both the fracture and the patient. Diabetic patients and smokers are at greater risk of post-operative complication, especially wound problems and infection. Likewise, the long term outcome of post-traumatic arthritis from a malunited ankle fracture is extremely important for a young patient, but not as relevant in the elderly. Therefore, normal surgical decision processes apply as with all fractures. Defining stability of an ankle fracture underpins the treatment decision. Weber A - Unimalleolar Weber A Weber fractures by definition are stable and therefore can be mobilised fully weight bearing in an ankle boot. Weber C - Fractures tend to include syndesmotic disruption and are usually bimalleolar (either bony or ligamentous). They are therefore unstable and usually require operative fixation. In addition to the fracture fixation, the syndesmosis usually requires reconstruction/augmentation with screws to restore the joint integrity and function. Weber B - B fractures vary greatly. They can be part of a trimalleolar injury and therefore extremely unstable, requiring fixation. Alternatively, a uni-malleolar Weber B fracture can be a stable injury, and therefore mobilised immediately in an ankle boot. Defining the stability can be challenging, and often involves stress radiographs, or a trial of mobilisation and repeat radiographs. However, treating undisplaced ankle fractures in a below knee plaster, non-weight bearing for six weeks is still widely practised, and a safe approach. When operative fixation is appropriate, it is usually via open reduction and internal fixation using plates and screws. It must be carried out when soft tissue swelling has settled in order to minimise the risk of wound problems. This can often take a week to settle. The use of fibula nails is expanding, but is not yet mainstream. Ankle fractures can also be treated with external fixation, or with a hind foot nail in patients who need fixation but where soft tissue or bone quality is poor. Post operative management Ankle fractures generally take 6 weeks to unite enough to prevent secondary displacement. This is therefore an appropriate time period to keep a cast on in a conservatively managed patient. Weight bearing post-operatively depends on the quality of the fixation and bone quality, and preference varies between surgeons, ranging from aggressive early mobilisation to a period of non-weight bearing. Return to activities takes approximately three months, and often requires assistance of a physiotherapist to improve range-of-movement and muscle strengthening. References 1. http://www.boa.ac.uk/publications/boa-standards-trauma-boasts/ 2. Shah AS, Kadakia AR, Tan GJ, Karadsheh MS, Wolter TD, Sabb B. Radiographic evaluation of the normal distal tibiofibular syndesmosis. Foot Ankle Int. 2012;33(10):870-6

Answer 1503

In most cases the treatment of choice for acute cholecystitis is an acute cholecystectomy performed early in the illness. Delayed surgery particularly around 5- 7 days after presentation is much more technically challenging and is often best deferred. In most cases the procedure can be performed laparoscopically, even when acute inflammation is present. Gallstones Up to 24% of women and 12% of men may have gallstones. Of these up to 30% may develop local infection and cholecystitis. In patients subjected to surgery 12% will have stones contained within the common bile duct. The majority of gallstones are of a mixed composition (50%) with pure cholesterol stones accounting for 20% of cases. The aetiology of CBD stones differs in the world, in the West most CBD stones are the result of migration. In the East a far higher proportion arise in the CBD de novo. The classical symptoms are of colicky right upper quadrant pain that occurs post prandially. The symptoms are usually worst following a fatty meal when cholecystokinin levels are highest and gallbladder contraction is maximal. Investigation In almost all suspected cases the standard diagnostic work up consists of abdominal ultrasound and liver function tests. Of patients who have stones within the bile duct, 60% will have at least one abnormal result on LFT's. Ultrasound is an important test, but is operator dependent and therefore may occasionally need to be repeated if a negative result is at odds with the clinical picture. Where stones are suspected in the bile duct, the options lie between magnetic resonance cholangiography and intraoperative imaging. The choice between these two options is determined by the skills and experience of the surgeon. The advantages of intra operative imaging are less useful in making therapeutic decisions if the operator is unhappy about proceeding the bile duct exploration, and in such circumstances pre operative MRCP is probably a better option. Specific gallstone and gallbladder related disease Disease Features Management Biliary colic Colicky abdominal pain, worse post prandially, worse after fatty foods If imaging shows gallstones and history compatible then laparoscopic cholecystectomy Acute cholecystitis Right upper quadrant pain Fever Murphys sign on examination Occasionally mildly deranged LFT's (especially if Mirizzi syndrome) Imaging (USS) and cholecystectomy (ideally within 48 hours of presentation) (2) Gallbladder abscess Usually prodromal illness and right upper quadrant pain Swinging pyrexia Patient may be systemically unwell Generalised peritonism not present Imaging with USS +/- CT Scanning Ideally surgery, sub total cholecystectomy may be needed if Calots triangle is hostile In unfit patients percutaneous drainage may be considered Cholangitis Patient severely septic and unwell Jaundice Right upper quadrant pain Fluid resuscitation Broad spectrum intravenous antibiotics Correct any coagulopathy Early ERCP Gallstone ileus Patients may have a history of previous cholecystitis and known gallstones Small bowel obstruction (may be intermittent) Laparotomy and removal of gallstone from small bowel, the enterotomy must be made proximal to the site of obstruction and not at the site of obstruction. The fistula between the gallbladder and duodenum should not be interfered with. Acalculous cholecystitis Patients with inter current illness (e.g. diabetes, organ failure) Patient of systemically unwell Gallbladder inflammation in absence of stones High fever If patient fit then cholecystectomy, if unfit then percutaneous cholecystostomy Treatment Patients with asymptomatic gallstones rarely develop symptoms related to them (less than 2% per year) and may therefore be managed expectantly. In almost all cases of symptomatic gallstones the treatment of choice is cholecystectomy performed via the laparoscopic route. In the very frail patient there is sometimes a role for selective use of ultrasound guided cholecystostomy. During the course of the procedure some surgeons will routinely perform either intra operative cholangiography or laparoscopic USS to either confirm anatomy or to exclude CBD stones. The latter may be more easily achieved by use of laparoscopic ultrasound. If stones are found then the options lie between early ERCP in the day or so following surgery or immediate surgical exploration of the bile duct. When performed via the trans cystic route this adds little in the way of morbidity and certainly results in faster recovery. Where transcystic exploration fails the alternative strategy is that of formal choledochotomy. The exploration of a small duct is challenging and ducts of less than 8mm should not be explored. Small stones that measure less than 5mm may be safely left and most will pass spontaneously. Risks of ERCP(1) Bleeding 0.9% (rises to 1.5% if sphincterotomy performed) Duodenal perforation 0.4% Cholangitis 1.1% Pancreatitis 1.5% References 1. Williams E et al. Guidelines on the management of common bile duct stones (CBDS)Gut 2008;57:10041021 2. Gurusamy KS, Samraj K. Early versus delayed laparoscopic cholecystectomy for acute cholecystitis. Cochrane Database Syst Rev. 2006 Oct 18;(4):CD005440. 3. Gurusamy K and Davidson B. Gallstones. BMJ 2014 (348):27-30.

Answer 1504

The accessory nerve may be injured in operations in the posterior triangle. Injury will affect trapezius. Cranial nerves Cranial nerve lesions Olfactory nerve May be injured in basal skull fractures or involved in frontal lobe tumour extension. Loss of olfactory nerve function in relation to major CNS pathology is seldom an isolated event and thus it is poor localiser of CNS pathology. Optic nerve Problems with visual acuity may result from intra ocular disorders. Problems with the blood supply such as amaurosis fugax may produce temporary visual distortion. More important surgically is the pupillary response to light. The pupillary size may be altered in a number of disorders. Nerves involved in the resizing of the pupil connect to the pretectal nucleus of the high midbrain, bypassing the lateral geniculate nucleus and the primary visual cortex. From the pretectal nucleus neurones pass to the Edinger - Westphal nucleus, motor axons from here pass along with the oculomotor nerve. They synapse with ciliary ganglion neurones; the parasympathetic axons from this then innervate the iris and produce miosis. The miotic pupil is seen in disorders such as Horner's syndrome or opiate overdose. Mydriasis is the dilatation of the pupil in response to disease, trauma, drugs (or the dark!). It is pathological when light fails to induce miosis. The radial muscle is innervated by the sympathetic nervous system. Because the parasympathetic fibres travel with the oculomotor nerve they will be damaged by lesions affecting this nerve (e.g. cranial trauma). The response to light shone in one eye is usually a constriction of both pupils. This indicates intact direct and consensual light reflexes. When the optic nerve has an afferent defect the light shining on the affected eye will produce a diminished pupillary response in both eyes. Whereas light shone on the unaffected eye will produce a normal pupillary response in both eyes. This is referred to as the Marcus Gunn pupil and is seen in conditions such as optic neuritis. In a total CN II lesion shining the light in the affected eye will produce no response. Oculomotor nerve The pupillary effects are described above. In addition it supplies all ocular muscles apart from lateral rectus and superior oblique. Thus the affected eye will be deviated inferolaterally. Levator palpebrae superioris may also be impaired resulting in impaired ability to open the eye. Trochlear nerve The eye will not be able to look down. Trigeminal nerve Largest cranial nerve. Exits the brainstem at the pons. Branches are ophthalmic, maxillary and mandibular. Only the mandibular branch has both sensory and motor fibres. Branches converge to form the trigeminal ganglion (located in Meckels cave). It supplies the muscles of mastication and also tensor veli palatine, mylohyoid, anterior belly of digastric and tensor tympani. The detailed descriptions of the various sensory functions are described in other areas of the website. The corneal reflex is important and is elicited by applying a small tip of cotton wool to the cornea, a reflex blink should occur if it is intact. It is mediated by: the naso ciliary branch of the ophthalmic branch of the trigeminal (sensory component) and the facial nerve producing the motor response. Lesions of the afferent arc will produce bilateral absent blink and lesions of the efferent arc will result in a unilateral absent blink. Abducens nerve The affected eye will have a deficit of abduction. This cranial nerve exits the brainstem between the pons and medulla. It thus has a relatively long intra cranial course which renders it susceptible to damage in raised intra cranial pressure. Facial nerve Emerges from brainstem between pons and medulla. It controls muscles of facial expression and taste from the anterior 2/3 of the tongue. The nerve passes into the petrous temporal bone and into the internal auditory meatus. It then passes through the facial canal and exits at the stylomastoid foramen. It passes through the parotid gland and divides at this point. It does not innervate the parotid gland. Its divisions are considered in other parts of the website. Its motor fibres innervate orbicularis oculi to produce the efferent arm of the corneal reflex. In surgical practice it may be injured during parotid gland surgery or invaded by malignancies of the gland and a lower motor neurone on the ipsilateral side will result. Vestibulo-cochlear nerve Exits from the pons and then passes through the internal auditory meatus. It is implicated in sensorineural hearing loss. Individuals with sensorineural hearing loss will localise the sound in webers test to the normal ear. Rinnes test will be reduced on the affected side but should still work. These two tests will distinguish sensorineural hearing loss from conductive deafness. In the latter condition webers test will localise to the affected ear and Rinnes test will be impaired on the affected side. Surgical lesions affecting this nerve include CNS tumours and basal skull fractures. It may also be damaged by the administration of ototoxic drugs (of which gentamicin is the most commonly used in surgical practice). Glossopharyngeal nerve Exits the pons just above the vagus. Receives sensory fibres from posterior 1/3 tongue, tonsils, pharynx and middle ear (otalgia may occur following tonsillectomy). It receives visceral afferents from the carotid bodies. It supplies parasympathetic fibres to the parotid gland via the otic ganglion and motor function to stylopharyngeaus muscle. The sensory function of the nerve is tested using the gag reflex. Vagus nerve Leaves the medulla between the olivary nucleus and the inferior cerebellar peduncle. Passes through the jugular foramen and into the carotid sheath. Details of the functions of the vagus nerve are covered in the website under relevant organ sub headings. Accessory nerve Exists from the caudal aspect of the brainstem (multiple branches) supplies trapezius and sternocleidomastoid muscles. The distal portion of this nerve is most prone to injury during surgical procedures. Hypoglossal nerve Emerges from the medulla at the preolivary sulcus, passes through the hypoglossal canal. It lies on the carotid sheath and passes deep to the posterior belly of digastric to supply muscles of the tongue (except palatoglossus). Its location near the carotid sheath makes it vulnerable during carotid endarterectomy surgery and damage will produce ipsilateral defect in muscle function.

Answer 1505

The psoas major inserts into the lesser trochanter and contracts when raising the trunk from the supine position. When osteolytic lesions are present in the femur the lesser trochanter may be avulsed. Psoas Muscle Origin The deep part originates from the transverse processes of the five lumbar vertebrae, the superficial part originates from T12 and the first 4 lumbar vertebrae. Insertion Lesser trochanter of the femur. Innervation Anterior rami of L1 to L3. Action Flexion and external rotation of the hip. Bilateral contraction can raise the trunk from the supine position.

Answer 1506

Beta-naphthalamine is used in the rubber industry. The following factors are associated with the development of bladder cancer: smoking occupational: aniline dyes used in printing and textile industry, rubber manufacture schistosomiasis drugs: cyclophosphamide Occupational cancers Occupational cancers accounted for 5.3% cancer deaths in 2005. In men the main cancers include: Mesothelioma Bladder cancer Non melanoma skin cancer Lung cancer Sino nasal cancer Occupations with high levels of occupational tumours include: Construction industry Working with coal tar and pitch Mining Metalworkers Working with asbestos (accounts for 98% of all mesotheliomas) Working in rubber industry Shift work has been linked to breast cancer in women (Health and safety executive report RR595). The latency between exposure and disease is typically 15 years for solid tumours and 20 for leukaemia. Many occupational cancers are otherwise rare. For example sino nasal cancer is an uncommon tumour, 50% will be SCC. They are linked to conditions such as wood dust exposure and unlike lung cancer is not strongly linked to cigarette smoking. Another typical occupational tumour is angiosarcoma of the liver which is linked to working with vinyl chloride. Again in the non occupational context this is an extremely rare sporadic tumour.

Answer 1507

This man needs urgent decompression and extradural haematoma is the most likely event, from a lacerated middle meningeal artery. Most neurosurgeons would perform a craniotomy. However, rural units and those units without neurosurgical kit facing this emergency may resort to Burr Holes. Head injury management- NICE Guidelines Summary of guidelines All patients should be assessed within 15 minutes on arrival to A&E Document all 3 components of the GCS If GCS <8 or = to 8, consider stabilising the airway Full spine immobilisation until assessment if: - GCS < 15 - neck pain/tenderness - paraesthesia extremities - focal neurological deficit - suspected c-spine injury If a c-spine injury is suspected a 3 view c-spine x-ray is indicated. CT c-spine is preferred if: - Intubated - GCS <13 - Normal x-ray but continued concerns regarding c-spine injury - Any focal neurology - A CT head scan is being performed - Initial plain films are abnormal Immediate CT head (within 1 hour) if: GCS < 12 on admission GCS < 15 2 hours after admission Suspected open or depressed skull fracture Suspected skull base fracture (panda eyes, Battle's sign, CSF from nose/ear, bleeding ear) Focal neurology Vomiting > 1 episode Post traumatic seizure Contact neurosurgeon if: Persistent GCS < 8 or = 8 Unexplained confusion > 4h Reduced GCS after admission Progressive neurological signs Incomplete recovery post seizure Penetrating injury Cerebrospinal fluid leak Observations 1/2 hourly GCS until 15 In the latest guidance, there is a move to considering CT in those on anticoagulants rather than mandating it. Reference 1. NICE Guidance NG 232 (Published 2023). 2. Hodgkinson S et al. Early management of head injury: summary of NICE guidance. BMJ 2014 (348):34-37.

Answer 1508

A non suction drain is the preferred option here. Surgical drains Drains are inserted in many surgical procedures and are of many types. As a broad rule they can be divided into those using suction and those which do not. The diameter of the drain will depend upon the substance being drained, for example smaller lumen drain for pneumothoraces vs haemothorax. Drains can be associated with complications and these begin with insertion when there may be iatrogenic damage. When in situ they serve as a route for infections. In some specific situations they may cause other complications, for example suction drains left in contact with bowel for long periods may carry a risk of inducing fistulation. Drains should be inserted for a defined purpose and removed once the need has passed. A brief overview of types of drain and sites is given below CNS Low suction drain or free drainage systems may be used for situations such as drainage of sub dural haematomas. CVS Following cardiothoracic procedures of thoracic trauma underwater seal drains are often placed. These should be carefully secured. When an air leak is present they may be placed on suction whilst the air leak settles Orthopaedics and trauma In this setting drains are usually used to prevent haematoma formation (with associated risk of infection). Some orthopaedic drains may also be specially adapted to allow the drained blood to be auto transfused. Gastro-intestinal surgery Surgeons often place abdominal drains either to prevent or drain abscesses, or to turn an anticipated complication into one that can be easily controlled such as a bile leak following cholecystectomy. The type of drain used will depend upon the indication. Drain types Type of drain Features Redivac Suction type of drain Closed drainage system High pressure vacuum system Low pressure drainage systems Consist of small systems such as the lantern style drain that may be used for short term drainage of small wounds and cavities Larger systems are sometimes used following abdominal surgery, they have a lower pressure than the redivac system, which decreases the risks of fistulation May be emptied and re-pressurised Latex tube drains May be shaped (e.g. T Tube) or straight Usually used in non pressurised systems and act as sump drains Most often used when it is desirable to generate fibrosis along the drain track (e.g. following exploration of the CBD) Chest drains May be large or small diameter (depending on the indication) Connected to underwater seal system to ensure one way flow of air Corrugated drain Thin, wide sheet of plastic, usually soft Contains corrugations, along which fluids can track

Answer 1509

Neurological signs combined with abdominal pain is acute intermittent porphyria or lead poisoning until proven otherwise. Acute intermittent porphyria Acute intermittent porphyria (AIP) is a rare autosomal dominant condition caused by a defect in porphobilinogen deaminase, an enzyme involved in the biosynthesis of haem. The results in the toxic accumulation of delta aminolaevulinic acid and porphobilinogen. It characteristically presents with abdominal and neuropsychiatric symptoms in 20-40 year olds. AIP is more common in females (5:1) Features abdominal: abdominal pain, vomiting neurological: motor neuropathy psychiatric: e.g. depression hypertension and tachycardia common Diagnosis classically urine turns deep red on standing raised urinary porphobilinogen (elevated between attacks and to a greater extent during acute attacks) assay of red cells for porphobilinogen deaminase raised serum levels of delta aminolaevulinic acid and porphobilinogen

Answer 1510

Surgical excision of tender breast tissue is inappropriate Methotrexate is used for the treatment of breast cancer. Whilst the use of tamoxifen is of benefit other agents such as flaxseed oil or evening primrose oil should be tried first. Danazol is effective, but many women dislike the side effects. Benign cyclical mastalgia Benign cyclical mastalgia is a common cause of breast pain in younger females. It varies in intensity according to the phase of the menstrual cycle. It is not associated with point tenderness of the chest wall (more likely to be Tietze's syndrome). The underlying cause is difficult to pinpoint, examination should focus on identifying focal lesions (such as cysts) that may be treated to provide symptomatic benefit. Women should be advised to wear a supportive bra. Conservative treatments include flax seed oil and evening primrose oil. There is slightly more evidence in favor of flax seed oil, though neither has performed much better than placebo in RCT's. Hormonal agents such as bromocriptine and danazol may be more effective. However, many women discontinue these therapies due to adverse effects.

Answer 1511

The penis takes autonomic nerves from the nervi erigentes that lie near the seminal vesicles. These may be compromised by direct surgical trauma (such as use of diathermy in this area) and also by radiotherapy that is used in these patients pre operatively. The result is that up to 50% of patients may develop impotence following rectal cancer surgery. Penile erection Physiology of erection Autonomic Sympathetic nerves originate from T11-L2 and parasympathetic nerves from S2-4 join to form pelvic plexus. Parasympathetic discharge causes erection, sympathetic discharge causes ejaculation and detumescence. Somatic nerves Supplied by dorsal penile and pudendal nerves. Efferent signals are relayed from Onufs nucleus (S2-4) to innervate ischiocavernosus and bulbocavernosus muscles. Autonomic discharge to the penis will trigger the veno-occlusive mechanism which triggers the flow of arterial blood into the penile sinusoidal spaces. As the inflow increases the increased volume in this space will secondarily lead to compression of the subtunical venous plexus with reduced venous return. During the detumesence phase the arteriolar constriction will reduce arterial inflow and thereby allow venous return to normalise. Priapism Prolonged unwanted erection, in the absence of sexual desire, lasting more than 4 hours. Classification of priapism Low flow priapism Due to veno-occlusion (high intracavernosal pressures). Most common type Often painful Often low cavernosal flow If present for >4 hours requires emergency treatment High flow priapism Due to unregulated arterial blood flow. Usually presents as semi rigid painless erection Recurrent priapism Typically seen in sickle cell disease, most commonly of high flow type. Causes Intracavernosal drug therapies (e.g. for erectile dysfunction> Blood disorders such as leukaemia and sickle cell disease Neurogenic disorders such as spinal cord transection Trauma to penis resulting in arterio-venous malformations Tests Exclude sickle cell/ leukaemia Consider blood sampling from cavernosa to determine whether high or low flow (low flow is often hypoxic) Management Ice packs/ cold showers If due to low flow then blood may be aspirated from copora or try intracavernosal alpha adrenergic agonists. Delayed therapy of low flow priapism may result in erectile dysfunction.

Answer 1512

Noradrenaline is the precursor of adrenaline. It is a powerful α 1 stimulant (although it will increase myocardial contractility). Infusions will produce vasoconstriction and an increase in total peripheral resistance. It is the inotrope of choice in septic shock. Inotropes and cardiovascular receptors Inotropes are a class of drugs which work primarily by increasing cardiac output. They should be distinguished from vasoconstrictor drugs which are used specifically when the primary problem is peripheral vasodilatation. Catecholamine type agents are commonly used and work by increasing cAMP levels by adenylate cyclase stimulation. This in turn increases intracellular calcium ion mobilisation and thus the force of contraction. Adrenaline works as a beta adrenergic receptor agonist at lower doses and an alpha receptor agonist at higher doses. Dopamine causes dopamine receptor mediated renal and mesenteric vascular dilatation and beta 1 receptor agonism at higher doses. This results in increased cardiac output. Since both heart rate and blood pressure are raised, there is less overall myocardial ischaemia. Dobutamine is a predominantly beta 1 receptor agonist with weak beta 2 and alpha receptor agonist properties. Noradrenaline is a catecholamine type agent and predominantly acts as an alpha receptor agonist and serves as a peripheral vasoconstrictor. Phosphodiesterase inhibitors such as milrinone act specifically on the cardiac phosphodiesterase and increase cardiac output. Inotrope Cardiovascular receptor action Adrenaline α-1, α-2, β-1, β-2 Noradrenaline α-1,( α-2), (β-1), (β-2) Dobutamine β-1, (β 2) Dopamine (α-1), (α-2), (β-1), D-1,D-2 Minor receptor effects in brackets Effects of receptor binding α-1, α-2 vasoconstriction β-1 increased cardiac contractility and HR β-2 vasodilatation D-1 renal and spleen vasodilatation D-2 inhibits release of noradrenaline

Answer 1513

CUSA systems minimize thermal injury and current flow to the surrounding areas. Diathermy - Diathermy devices are used by surgeons in all branches of surgery. Use electric currents to produce local heat and thereby facilitate haemostasis or surgical dissection. Consist of a generator unit that is located outside the patient and can be set to the level of power required by the surgeon. There are two major types of diathermy machine; Monopolar The current flows through the diathermy unit into a handheld device that is controlled by the surgeon. Electricity can flow from the tip of the device into the patient. The earth electrode is located some distance away. The relatively narrow tip of the diathermy device produces local heat and this can be used to vaporise and fulgurate tissues. The current can be adjusted in terms of frequency so that different actions can be effected. In cutting mode sufficient power is applied to the tissues to vaporise their water content. In coagulation mode the power level is reduced so that a coagulum is formed instead. Some diathermy machines can utilise a setting known as blend that alternates cutting and coagulation functions, these tend to be used during procedures such as colonoscopic polypectomy. Bipolar The electric current flows from one electrode to another however, both electrodes are usually contained within the same device e.g. a pair of forceps. The result is that heating is localised to the area between the two electrodes and surrounding tissue damage is minimised. Ultrasound based devices These include CUSA and Harmonic scalpel. They generate high frequency oscillations that seal and coagulate tissues. They have different energy settings that allow them to dissect and simultaneously seal vessels if required. The CUSA device leaves vessels intact that may then be divided. Ligasure device Delivers tailored energy levels to allow simultaneous haemostasis and dissection. The device senses the impedance of the tissues and tailors energy levels accordingly. Hazards of diathermy Inadvertent patient burn. This may result of careless handling of the device or in the case of monopolar devices forgetting to apply a return electrode plate, In this situation patients may develop a contact burn when electricity flows to earth Explosion or fire. This may occur when volatile anaesthetic gases or skin preparation fluid have been used

Answer 1514

The diagnosis is thyrotoxicosis. An elevated T4 and a low TSH should indicate this diagnosis. Remember atrial fibrillation and its complications i.e acute ischaemic limbs can be precipitated by hyperthyroid disorders. Thyroid function tests The interpretation of thyroid function tests is usually straightforward: Disorder TSH Free T4 Thyrotoxicosis (e.g. Graves' disease) Low High In T3 thyrotoxicosis the free T4 will be normal Primary hypothyroidism (primary atrophic hypothyroidism) High Low Secondary hypothyroidism Low Low Replacement steroid therapy is required prior to thyroxine Sick euthyroid syndrome* Low** Low Common in hospital inpatients Poor compliance with thyroxine High Normal / high Steroid therapy Low Normal *now referred to as non-thyroidal illness **TSH may be normal in some cases

Answer 1515

In patients with long standing PUJ obstruction and renal scarring the main diagnostic question is whether the individual has sufficient renal function to consider a pyeloplasty or whether a primary nephrectomy is preferable. Since the CT has demonstrated scarring there is no use in obtaining a DMSA scan. Of the investigations listed both a DMSA and MAG 3 renogram will allow assessment of renal function. However, MAG 3 is superior in the assessment of renal function in damaged kidneys (as it is subjected to tubular secretion). Functional renal imaging DMSA scan Dimercaptosuccinic acid (DMSA) scintigraphy DMSA localises to the renal cortex with little accumulation in the renal papilla and medulla. It is useful for the identification of cortical defects and ectopic or aberrant kidneys. It does not provide useful information on the ureter of collecting system. Diethylene-triamine-penta-acetic acid (DTPA) This is primarily a glomerular filtration agent. It is most useful for the assessment of renal function. Because it is filtered at the level of the glomerulus it provides useful information about the GFR. Image quality may be degraded in patients with chronic renal impairment and derangement of GFR. MAG 3 renogram Mercaptoacetyle triglycine is an is extensively protein bound and is primarily secreted by tubular cells rather than filtered at the glomerulus. This makes it the agent of choice for imaging the kidneys of patients with existing renal impairment (where GFR is impaired). Micturating cystourethrogram (MCUG scan) This scan provides information relating to bladder reflux and is obtained by filling the bladder with contrast media (via a catheter) and asking the child to void. Images are taken during this phase and the degree of reflux can be calculated Intra venous urography This examination is conducted by the administration of intravenous iodinated contrast media. The agent is filtered by the kidneys and excreted and may provide evidence of renal stones or other structural lesions. A rough approximation of renal function may be obtained using the technique. But it is not primarily a technique to be used for this purpose. With the advent of widespread non contrast CT scan protocols for the detection of urinary tract calculi it is now rarely used. PET/CT This may be used to evaluate structurally indeterminate lesions in the staging of malignancy. References Davis A et al. Investigating urinary tract infections in children. BMJ 2013 (346):35-37.

Answer 1516

The central perineal tendon provides the main structural support to the uterus. Damage to this structure is commonly associated with the development of pelvic organ prolapse, even when other structures are intact. Uterus The non pregnant uterus resides entirely within the pelvis. The peritoneum invests the uterus and the structure is contained within the peritoneal cavity. The blood supply to the uterine body is via the uterine artery (branch of the internal iliac). The uterine artery passes from the inferior aspect of the uterus (lateral to the cervix) and runs alongside the uterus. It frequently anastomoses with the ovarian artery superiorly. Inferolaterally, the ureter is a close relation and ureteric injuries are a recognised complication when pathology brings these structures into close proximity. The supports of the uterus include the central perineal tendon (the most important). The lateral cervical, round and uterosacral ligaments are condensations of the endopelvic fascia and provide additional structural support.

Answer 1517

Diagnosing dehydration can be complicated, laboratory features include: Hypernatraemia Rising haematocrit Metabolic acidosis Rising lactate Increased serum urea to creatinine ratio Urinary sodium <20 mmol/litre Urine osmolality approaching 1200mosmol/kg Pre operative fluid management Fluid management has been described in the British Consensus guidelines on IV fluid therapy for Adult Surgical patients (GIFTASUP) and by NICE (CG174 December 2013 updated May 2017) The Recommendations include: Use Ringer's lactate or Hartmann's when a crystalloid is needed for resuscitation or replacement of fluids. Avoid 0.9% N. Saline (due to risk of hyperchloraemic acidosis) unless patient vomiting or has gastric drainage. Use 4%/0.18% dextrose saline or 5% dextrose in maintenance fluids. It should not be used in resuscitation or as replacement fluids. Adult maintenance fluid requirements are: Na 50-100 mmol/day and K 40-80 mmol/day in 1.5-2.5L fluid per day. Patients for elective surgery should NOT be nil by mouth for >2 hours (unless has disorder of gastric emptying). Patients for elective surgery should be given carbohydrate rich drinks 2-3h before. Ideally this should form part of a normal pre op plan to facilitate recovery. Avoid mechanical bowel preparation. If bowel prep is used, simultaneous administration of Hartmann's or Ringer's lactate should be considered. Excessive fluid losses from vomiting should be treated with a crystalloid with potassium replacement. 0.9% N. Saline should be given if there is hypochloraemia. Otherwise Hartmann's or Ringer lactate should be given for diarrhoea/ileostomy/ileus/obstruction. Hartmann's should also be given in sodium losses secondary to diuretics. High risk patients should receive fluids and inotropes. An attempt should be made to detect pre or operative hypovolaemia using flow based measurements. If this is not available, then clinical evaluation is needed i.e. JVP, pulse volume etc. In Blood loss or infection causing hypovolaemia should be treated with a balanced crystalloid or colloid (or until blood available in blood loss). A critically ill patient is unable to excrete Na or H20 leading to a 5% risk of interstitial oedema. Therefore 5% dextrose as well as colloid should be given. If patients need IV fluid resuscitation, use crystalloids that contain sodium in the range 130-154 mmol/l, with a bolus of 500 ml over less than 15 minutes (NICE Guidance CG 174).

Answer 1518

B-An intravenous sliding scale should be used in all cases A sliding scale (or the real name: variable-rate intravenous insulin infusion, sometimes abbreviated to 'VRIII') is an intravenous drip with insulin and glucose, two separate lines which enter the hand or wrist via one intravenous needle This is not the case and some type 2 diabetics may be managed using a watch and wait policy with regular blood glucose monitoring. The cellular shifts of potassium with sliding scales may cause problems with electrolyte management which should be anticipated. Preparation for surgery Elective and emergency patients require different preparation. Elective cases Consider pre admission clinic to address medical issues. Blood tests including FBC, U+E, LFT's, Clotting, Group and Save Urine analysis Pregnancy test Sickle cell test ECG/ Chest x-ray Exact tests to be performed will depend upon the proposed procedure and patient fitness. Risk factors for development of deep vein thrombosis should be assessed and a plan for thromboprophylaxis formulated. Diabetes Diabetic patients have greater risk of complications. Poorly controlled diabetes carries high risk of wound infections. Patients with diet or tablet controlled diabetes may be managed using a policy of omitting medication and checking blood glucose levels regularly. Diabetics who are poorly controlled or who take insulin may require a intravenous sliding scale. Potassium supplementation should also be given. Diabetic cases should be operated on first. Emergency cases Stabilise and resuscitate where needed. Consider whether antibiotics are needed and when and how they should be administered. Inform blood bank if major procedures planned particularly where coagulopathies are present at the outset or anticipated (e.g. Ruptured AAA repair) Don't forget to consent and inform relatives. Special preparation Some procedures require special preparation: Thyroid surgery; vocal cord check. Parathyroid surgery; consider methylene blue to identify gland. Sentinel node biopsy; radioactive marker/ patent blue dye. Surgery involving the thoracic duct; consider administration of cream. Pheochromocytoma surgery; will need alpha and beta blockade. Surgery for carcinoid tumours; will need covering with octreotide. Colorectal cases; bowel preparation (especially left sided surgery) Thyrotoxicosis; lugols iodine/ medical therapy. References Management of adults with diabetes undergoing surgery and elective procedures. NHS Diabetes. April 2011.

Answer 1519

Whilst not an indication for immediate CT there should be a low threshold for admission and observation. Head injury paediatrics Criteria for immediate request for CT scan of the head (children) * Loss of consciousness lasting more than 5 minutes (witnessed) * Amnesia (antegrade or retrograde) lasting more than 5 minutes * Abnormal drowsiness * Three or more discrete episodes of vomiting * Clinical suspicion of non-accidental injury * Post-traumatic seizure but no history of epilepsy * GCS less than 14, or for a baby under 1 year GCS (paediatric) less than 15, on assessment in the emergency department * Suspicion of open or depressed skull injury or tense fontanelle * Any sign of basal skull fracture (haemotympanum, panda' eyes, cerebrospinal fluid leakage from the ear or nose, Battle's sign) * Focal neurological deficit * If under 1 year, presence of bruise, swelling or laceration of more than 5 cm on the head * Dangerous mechanism of injury (high-speed road traffic accident either as pedestrian, cyclist or vehicle occupant, fall from a height of greater than 3 m, high-speed injury from a projectile or an object)

Answer 1520

Electrical high voltage burns are associated with rhabdomyolysis. Acute tubular necrosis may occur. Aggressive IV fluids should be given. Burns Burns may be thermal, chemical or electrical. In the former category are burns which occur as a result of heat. Chemical burns occur when the skin is exposed to an extremely caustic or alkaline substance. Electrical burns occur following exposure to electrical current. The immediate management includes removal of the burning source which usually includes irrigation of the burned area. A detailed assessment then needs to be made of the extent of the burns and a number of charts are available for recording this information. The degree of injury relates to the temperature and duration of exposure. Most domestic burns are mainly scalds in young children. Following the burn, there is a local response with progressive tissue loss and release of inflammatory cytokines. Systemically, there are cardiovascular effects resulting from fluid loss and sequestration of fluid into the third space. There is a marked catabolic response. Immunosuppression is common with large burns and bacterial translocation from the gut lumen is a recognised event. Sepsis is a common cause of death following major burns. Types of burn Type of burn Skin layers affected Skin appearance Blanching Management Epidermal/Superficial Epidermis Red, moist Yes Superficial partial thickness Epidermis and part of papillary dermis affected Pale, dry Yes Normally heals with no intervention Deep partial thickness Epidermis, whole papillary dermis affected Mottled red colour No Needs surgical intervention (depending on site) Full thickness Whole skin layer and subcutaneous tissue affected Dry, leathery hard wound No Burns centre Depth of burn assessment Bleeding on needle prick Sensation Appearance Blanching to pressure Percentage burn estimation Lund Browder chart: most accurate even in children Wallace rule of nines Palmar surface: surface area palm = 0.8% burn >15% body surface area burns in adults needs urgent burn fluid resuscitation Transfer to burn centre if: Need burn shock resuscitation Face/hands/genitals affected Deep partial thickness or full thickness burns Significant electrical/chemical burns Management The initial aim is to stop the burning process and resuscitate the patient. Intravenous fluids will be required for children with burns greater than 10% of total body surface area. Adults with burns greater than 15% of total body surface area will also require IV fluids. The fluids are calculated using the Parkland formula which is; volume of fluid= total body surface area of the burn % x weight (Kg) x2-4 (preference for lower amount i.e. 2ml to avoid excessive fluid overload). Half of the fluid is administered in the first 8 hours. A urinary catheter should be inserted. Analgesia should be given. Complex burns, burns involving the hand perineum and face and burns >10% in adults and >5% in children should be transferred to a burns unit. Circumferential burns affecting a limb or severe torso burns impeding respiration may require escharotomy to divide the burnt tissue. Conservative management is appropriate for superficial burns and mixed superficial burns that will heal in 2 weeks. More complex burns may require excision and skin grafting. Excision and primary closure is not generally practised as there is a high risk of infection. There is no evidence to support the use of anti microbial prophylaxis or topical antibiotics in burn patients. Escharotomies Indicated in circumferential full thickness burns to the torso or limbs. Careful division of the encasing band of burn tissue will potentially improve ventilation (if the burn involves the torso), or relieve compartment syndrome and oedema (where a limb is involved) References www.euroburn.org/e107files/downloads/guidelinesburncare.pdf Barajas-Nava LA, LÃ³pez-Alcalde J, RoquÃ© i Figuls M, SolÃ I, Bonfill Cosp X. Antibiotic prophylaxis for preventing burn wound infection. Cochrane Database of Systematic Reviews 2013, Issue 6. Art. No.: CD008738. DOI: 10.1002/14651858.CD008738.pub2. Hettiaratchy S & Papini R. Initial management of a major burn: assessment and resuscitation. BMJ 2004;329:101-103

Answer 1521

Suxamethonium may induce generalised muscular contractions following administration. This may raise serum potassium levels. Muscle relaxants Suxamethonium Depolarising neuromuscular blocker Inhibits action of acetylcholine at the neuromuscular junction Degraded by plasma cholinesterase and acetylcholinesterase (affected by lack of acetylcholinesterase) Fastest onset and shortest duration of action of all muscle relaxants Produces generalised muscular contraction prior to paralysis Adverse effects include hyperkalaemia, malignant hyperthermia, delayed recovery Atracurium Non depolarising neuromuscular blocking drug Duration of action usually 30-45 minutes Generalised histamine release on administration may produce facial flushing, tachycardia and hypotension Not excreted by liver or kidney, broken down in tissues by hydrolysis Reversed by neostigmine Vecuronium Non depolarising neuromuscular blocking drug Duration of action approximately 30 - 40 minutes Degraded by liver and kidney and effects prolonged in organ dysfunction Effects may be reversed by neostigmine Pancuronium Non depolarising neuromuscular blocker Onset of action approximately 2-3 minutes Duration of action up to 2 hours Effects may be partially reversed with drugs such as neostigmine

Answer 1522

Bicarbonate is a crystalloid. Pre operative fluid management Fluid management has been described in the British Consensus guidelines on IV fluid therapy for Adult Surgical patients (GIFTASUP) and by NICE (CG174 December 2013 updated May 2017) The Recommendations include: Use Ringer's lactate or Hartmann's when a crystalloid is needed for resuscitation or replacement of fluids. Avoid 0.9% N. Saline (due to risk of hyperchloraemic acidosis) unless patient vomiting or has gastric drainage. Use 4%/0.18% dextrose saline or 5% dextrose in maintenance fluids. It should not be used in resuscitation or as replacement fluids. Adult maintenance fluid requirements are: Na 50-100 mmol/day and K 40-80 mmol/day in 1.5-2.5L fluid per day. Patients for elective surgery should NOT be nil by mouth for >2 hours (unless has disorder of gastric emptying). Patients for elective surgery should be given carbohydrate rich drinks 2-3h before. Ideally this should form part of a normal pre op plan to facilitate recovery. Avoid mechanical bowel preparation. If bowel prep is used, simultaneous administration of Hartmann's or Ringer's lactate should be considered. Excessive fluid losses from vomiting should be treated with a crystalloid with potassium replacement. 0.9% N. Saline should be given if there is hypochloraemia. Otherwise Hartmann's or Ringer lactate should be given for diarrhoea/ileostomy/ileus/obstruction. Hartmann's should also be given in sodium losses secondary to diuretics. High risk patients should receive fluids and inotropes. An attempt should be made to detect pre or operative hypovolaemia using flow based measurements. If this is not available, then clinical evaluation is needed i.e. JVP, pulse volume etc. In Blood loss or infection causing hypovolaemia should be treated with a balanced crystalloid or colloid (or until blood available in blood loss). A critically ill patient is unable to excrete Na or H20 leading to a 5% risk of interstitial oedema. Therefore 5% dextrose as well as colloid should be given. If patients need IV fluid resuscitation, use crystalloids that contain sodium in the range 130-154 mmol/l, with a bolus of 500 ml over less than 15 minutes (NICE Guidance CG 174).

Answer 1523

Plantar ulcers in association with peripheral neuropathy are often neuropathic. They classically occur at pressure points. Lower leg ulcers Venous leg ulcers Most due to venous hypertension, secondary to chronic venous insufficiency (other causes include calf pump dysfunction or neuromuscular disorders) Ulcers form due to capillary fibrin cuff or leucocyte sequestration Features of venous insufficiency include oedema, brown pigmentation, lipodermatosclerosis, eczema Location above the ankle, painless Deep venous insufficiency is related to previous DVT and superficial venous insufficiency is associated with varicose veins Doppler ultrasound looks for presence of reflux and duplex ultrasound looks at the anatomy/ flow of the vein Management: 4 layer compression banding after exclusion of arterial disease or surgery If fail to heal after 12 weeks or >10cm2 skin grafting may be needed Marjolin's ulcer Squamous cell carcinoma Occurring at sites of chronic inflammation e.g; burns, osteomyelitis after 10-20 years Mainly occur on the lower limb Arterial ulcers Occur on the toes and heel Painful There may be areas of gangrene Cold with no palpable pulses Low ABPI measurements Neuropathic ulcers Commonly over plantar surface of metatarsal head and plantar surface of hallux The plantar neuropathic ulcer is the condition that most commonly leads to amputation in diabetic patients Due to pressure Management includes cushioned shoes to reduce callus formation Pyoderma gangrenosum Associated with inflammatory bowel disease/RA Can occur at stoma sites Erythematous nodules or pustules which ulcerate

Answer 1524

The hernia can be repaired by either open or laparoscopic techniques. However, herniotomy is not performed as an isolated procedure in adults. The Bassini darn repair has a high recurrence rate. An open Lichtenstein repair using mesh is appropriate. There is a 0.77% recurrence rate with this technique. A Shouldice repair is an acceptable alternative if the surgeon is experienced Inguinal hernia surgery Inguinal hernias occur when the abdominal viscera protrude through the anterior abdominal wall into the inguinal canal. They may be classified as being either direct or indirect. The distinction between these two rests on their relation to Hesselbach's triangle. Boundaries of Hesselbach's Triangle Medial: Rectus abdominis Lateral: Inferior epigastric vessels Inferior: Inguinal ligament Hernias occurring within the triangle tend to be direct and those outside - indirect. Diagnosis Most cases are diagnosed clinically, a reducible swelling may be located at the level of the inguinal canal. Large hernia's may extend down into the male scrotum, these will not trans-illuminate and it is not possible to 'get above' the swelling. Cases that are unclear on examination, but suspected from the history, may be further investigated using ultrasound or by performing a herniogram. Treatment Hernias associated with few symptoms may be managed conservatively. Symptomatic hernias or those which are at risk of developing complications are usually treated surgically. First time hernias may be treated by performing an open inguinal hernia repair; the inguinal canal is opened, the hernia reduced and the defect repaired. A prosthetic mesh may be placed posterior to the cord structures to re-enforce the repair and reduce the risk of recurrence. Recurrent hernias and those which are bilateral are generally managed with a laparoscopic approach. This may be via an intra or extra peritoneal route. As in open surgery a mesh is deployed. However, it will typically lie posterior to the deep ring. Inguinal hernia in children Inguinal hernias in children are almost always of an indirect type and therefore are usually dealt with by herniotomy, rather than herniorraphy. Neonatal hernias especially in those children born prematurely are at highest risk of strangulation and should be repaired urgently. Other hernias may be repaired on an elective basis. References The UK Based National Institute of Clinical Excellence has published guidelines relating to the choice between open and laparoscopic inguinal hernia repair. Which users may find interesting: http://guidance.nice.org.uk/TA83/Guidance/pdf/English

Answer 1525

Structured exercise programmes combined with medical therapy will improve many patients. Should his symptoms worsen or fail to improve then a more comprehensive work up should be considered. Peripheral vascular disease Indications for surgery to revascularise the lower limb Intermittent claudication Critical ischaemia Ulceration Gangrene Intermittent claudication that is not disabling may provide a relative indication, whilst the other complaints are often absolute indications depending upon the frailty of the patient. Assessment Clinical examination Ankle brachial pressure index measurement Duplex arterial ultrasound Angiography (standard, CT or MRI): usually performed only if intervention being considered. Angioplasty In order for angioplasty to be undertaken successfully the artery has to be accessible. The lesion relatively short and reasonable distal vessel runoff. Longer lesions may be amenable to sub-intimal angioplasty. Surgery Surgery will be undertaken where attempts at angioplasty have either failed or are unsuitable. Bypass essentially involves bypassing the affected arterial segment by utilising a graft to run from above the disease to below the disease. As with angioplasty good runoff improves the outcome. Some key concepts with bypass surgery Superficial femoral artery occlusion to the above knee popliteal In the ideal scenario, vein (either in situ or reversed LSV) would be used as a conduit. However, prosthetic material has reasonable 5 year patency rates and some would advocate using this in preference to vein so that vein can be used for other procedures in the future. In general terms either technique is usually associated with an excellent outcome (if run off satisfactory). Procedure Artery dissected out, IV heparin 3,000 units given and then the vessels are cross clamped Longitudinal arteriotomy Graft cut to size and tunneled to arteriotomy sites Anastomosis to femoral artery usually with 5/0 'double ended' Prolene suture Distal anastomosis usually using 6/0 'double ended' Prolene Distal disease Femoro-distal bypass surgery takes longer to perform, is more technically challenging and has higher failure rates. In elderly diabetic patients with poor runoff a primary amputation may well be a safer and more effective option. There is no point in embarking on this type of surgery in patients who are wheelchair bound. In femorodistal bypasses vein gives superior outcomes to PTFE. Rules Vein mapping 1st to see whether there is suitable vein (the preferred conduit). Sub intimal hyperplasia occurs early when PTFE is used for the distal anastomosis and will lead to early graft occlusion and failure. Essential operative procedure as for above knee fem-pop. If there is insufficient vein for the entire conduit then vein can be attached to the end of the PTFE graft and then used for the distal anastomosis. This type of 'vein boot' is technically referred to as a Miller Cuff and is associated with better patency rates than PTFE alone. Remember the more distal the arterial anastomosis the lower the success rate. References Peach G et al. Diagnosis and management of peripheral arterial disease. BMJ 2012; 345: 36-41.

Answer 1526

Although MAG 3 renograms may provide some information relating to the structural integrity of the kidney, many still consider a DMSA scan to be the gold standard for the detection of renal scarring (which is the main concern in PUJ obstruction and infections). Functional renal imaging DMSA scan Dimercaptosuccinic acid (DMSA) scintigraphy DMSA localises to the renal cortex with little accumulation in the renal papilla and medulla. It is useful for the identification of cortical defects and ectopic or aberrant kidneys. It does not provide useful information on the ureter of collecting system. Diethylene-triamine-penta-acetic acid (DTPA) This is primarily a glomerular filtration agent. It is most useful for the assessment of renal function. Because it is filtered at the level of the glomerulus it provides useful information about the GFR. Image quality may be degraded in patients with chronic renal impairment and derangement of GFR. MAG 3 renogram Mercaptoacetyle triglycine is an is extensively protein bound and is primarily secreted by tubular cells rather than filtered at the glomerulus. This makes it the agent of choice for imaging the kidneys of patients with existing renal impairment (where GFR is impaired). Micturating cystourethrogram (MCUG scan) This scan provides information relating to bladder reflux and is obtained by filling the bladder with contrast media (via a catheter) and asking the child to void. Images are taken during this phase and the degree of reflux can be calculated Intra venous urography This examination is conducted by the administration of intravenous iodinated contrast media. The agent is filtered by the kidneys and excreted and may provide evidence of renal stones or other structural lesions. A rough approximation of renal function may be obtained using the technique. But it is not primarily a technique to be used for this purpose. With the advent of widespread non contrast CT scan protocols for the detection of urinary tract calculi it is now rarely used. PET/CT This may be used to evaluate structurally indeterminate lesions in the staging of malignancy. References Davis A et al. Investigating urinary tract infections in children. BMJ 2013 (346):35-37.

Answer 1527

Coeliac plexus The coeliac plexus is the largest of the autonomic plexuses. It is located on a level of the last thoracic and first lumbar vertebrae. It surrounds the coeliac axis and the SMA. It lies posterior to the stomach and the lesser sac. It lies anterior to the crura of the diaphragm and the aorta. The plexus and ganglia are joined by the greater and lesser splanchnic nerves on both sides and branches from both the vagus and phrenic nerves.

Answer 1528

**Osteopetrosis** is a rare genetic disorder characterized by **increased bone density** due to defective bone resorption. This condition results from a defect in **osteoclast function**, the cells responsible for breaking down bone tissue during the normal process of bone remodeling. ### Explanation of the options: 1. **Osteoclast function**: This is the **correct answer**. Osteopetrosis is caused by impaired osteoclast activity, leading to defective bone resorption and excessive accumulation of dense, brittle bone. 2. **PTH receptors**: Defects in parathyroid hormone (PTH) receptors affect calcium and phosphate metabolism but do not cause osteopetrosis. PTH primarily regulates calcium levels by acting on bones, kidneys, and the intestines. 3. **Osteoblast function**: Osteoblasts are responsible for bone formation. A defect in osteoblast function would lead to decreased bone formation, not the increased bone density seen in osteopetrosis. 4. **Calcium resorption in proximal tubule**: This refers to kidney function and calcium homeostasis. Defects here would affect serum calcium levels but not bone density directly. 5. **Calcium absorption**: Impaired calcium absorption in the intestines (e.g., due to vitamin D deficiency) leads to conditions like rickets or osteomalacia, not osteopetrosis. ### Correct Answer: **Osteoclast function** Osteopetrosis is best explained by a defect in **osteoclast function**, leading to impaired bone resorption and abnormally increased bone density. This results in brittle bones that are prone to fractures despite their increased density.

Answer 1529

Ectopic testes are those that come to lie outside the normal range of embryological descent (i.e. in the superficial inguinal pouch). Other sites of ectopic testes include; base of penis, femoral triangle and perineum. Testicular disorders-paediatric Testicular disorders Testicular disorders are some of the commonest conditions present in paediatric urological practice. Cryptorchidism The embryological descent of the testicle from within the abdominal cavity may be subject to a number of variations. Distinctions need to be made clinically from a non descended testis and a testis that is retractile. Testis that lie outside the normal path of embryological descent are termed ectopic testis. Undescended testis occurs in 1% of male infants. Where the testis does not lie in an intra scrotal location, its location should be ascertained (by laparoscopy in first instance). Where both testes are absent, the infant may be intersex. MRI scanning may reveal intra-abdominal testes; however a GA is often needed to perform this investigation in this age group. Testes that are undescended should be placed in the scrotum after 1 year of age, as the testosterone surge that may facilitate descent occurs at 6 months of age. Where the testes lie distally e.g. Superficial inguinal pouch an open orchidopexy is the procedure of choice. With abdominal testes a laparoscopy should be performed. The risk of seminoma is increased in individuals with a non descended testes and this risk is not reduced by orchidopexy. Testicular torsion Typically the patient has severe sudden onset of scrotal pain. The difficulty in paediatric practice is the lack of clear history. On examination the testis is tender and enlarged. Management is by surgical exploration. Delay beyond 6 hours is associated with low salvage rates. A torted hyatid produces pain that is far more localised and the testis itself should feel normal. However, diagnostic doubt often exists and in such cases surgical exploration is warranted. Hydrocele Occur secondary to patent processus vaginalis Present as fluid filling in scrotum or as cyst of the spermatic cord Communicating hydroceles are treated by a trans inguinal ligation of the PPV Cystic hydroceles in older children may be treated with scrotal exploration

Answer 1530

Peroneus brevis lies in the lateral compartment. Fascial compartments of the leg Compartments of the thigh Formed by septae passing from the femur to the fascia lata. Compartment Nerve Muscles Blood supply Anterior compartment Femoral Iliacus Tensor fasciae latae Sartorius Quadriceps femoris Femoral artery Medial compartment Obturator Adductor longus/magnus/brevis Gracilis Obturator externus Profunda femoris artery and obturator artery Posterior compartment (2 layers) Sciatic Semimembranosus Semitendinosus Biceps femoris Branches of Profunda femoris artery Compartments of the lower leg Separated by the interosseous membrane (anterior and posterior compartments), anterior fascial septum (separate anterior and lateral compartments) and posterior fascial septum (separate lateral and posterior compartments) Compartment Nerve Muscles Blood supply Anterior compartment Deep peroneal nerve Tibialis anterior Extensor digitorum longus Extensor hallucis longus Peroneus tertius Anterior tibial artery Posterior compartment Tibial Muscles: deep and superficial compartments (separated by deep transverse fascia) Deep: Flexor hallucis longus, Flexor digitalis longus, Tibialis posterior, Popliteus Superficial: Gastrocnemius, Soleus, Plantaris Posterior tibial Lateral compartment Superficial peroneal Peroneus longus/brevis Peroneal artery

Answer 1531

Tumour markers Tumour markers may be divided into: monoclonal antibodies against carbohydrate or glycoprotein tumour antigens tumour antigens enzymes (alkaline phosphatase, neurone specific enolase) hormones (e.g. calcitonin, ADH) It should be noted that tumour markers usually have a low specificity Monoclonal antibodies Tumour marker Association CA 125 Ovarian cancer CA 19-9 Pancreatic cancer CA 15-3 Breast cancer NB: The breast cancer tumour marker is not specific or sensitive enough to be used routinely. Tumour antigens Tumour marker Association Prostate specific antigen (PSA) Prostatic carcinoma Alpha-feto protein (AFP) Hepatocellular carcinoma, teratoma Carcinoembryonic antigen (CEA) Colorectal cancer

Answer 1532

The sun should not rise and set on unrelieved large bowel obstruction! This patient has a competent ileocaecal valve. As a result lack of surgery would result in caecal perforation leading to faecal peritonitis with and associated high mortality rate. Large bowel obstruction Colonic obstruction remains a common surgical problem. It is most commonly due to malignancy (60%) and diverticular disease (20%). Volvulus affecting the colon accounts for 5% of cases. Acute colonic pseudo-obstruction remains a potential differential diagnosis in all cases. Intussusception affecting the colon (most often due to tumours in the adult population) remains a rare but recognised cause. The typical patient will present with gradual onset of progressive abdominal distension, colicky abdominal pain and either obstipation or absolute constipation. On examination abdominal distension is present, the presence of caecal tenderness (assuming no overt evidence of peritonitis) is a useful sign to elicit. A digital rectal examination and rigid sigmoidoscopy should be performed. A plain abdominal x-ray is the usual first line test and; the caecal diameter and ileocaecal valve competency should be assessed on this film. Imaging modalities Debate long surrounds the use of CT versus gastrograffin enemas. The latter investigation has always been the traditional method of determining whether a structural lesion is indeed present. However, in the UK the use of this technique has declined and in most units a CT scan will be offered as the first line investigation by the majority of radiologists (and is advocated by the ACPGBI). In most cases this will provide sufficient detail to allow operative planning, and since malignancy accounts for most presentations may also stage the disease. In the event that the radiologist cannot provide a clear statement of lesion site, the surgeon should have no hesitation in requesting a contrast enema. Surgical options The decision as to when to operate or not is determined firstly by the patients physiological status. Unstable patients require resuscitation prior to surgery and admission to a critical care unit for invasive monitoring and potential inotropic support may be needed. In patients who are otherwise stable the decision then rests on the radiological and clinical findings. As a general rule the old adage that the sun should not rise and set on unrelieved large bowel obstruction still holds true. A caecal diameter of 12cm or more in the presence of complete obstruction with a competent ileocaecal valve and caecal tenderness is a sign of impending perforation and a relative indication for prompt surgery. Right sided and transverse lesions Right sided lesions producing large bowel obstruction should generally be treated by right hemicolectomy or its extended variant if the lesion lies in the distal transverse colon or splenic flexure. In these cases an ileocolic anastomosis may be easily constructed and even in the emergency setting has a low risk of anastomotic leak. Left sided lesions The options here lie between sub total colectomy and anastomosis, left hemicolectomy with on table lavage and primary anastomosis, left hemicolectomy and end colostomy formation and finally colonic stent insertion. The usefulness of colonic stents was the subject of a Cochrane review in 2011. The authors concluded that on the basis of the data that they reviewed, there was no benefit from the use of colonic stents over conventional surgical resection with a tendency to better outcomes seen in the surgical group (1). A more recently conducted meta analysis met with the same conclusion (2). However, the recently concluded CREST trial has suggested that self expanding metallic stents can improve outcomes and avoids a stoma. Rectosigmoid lesions Lesions below the peritoneal reflection that are causing obstruction should generally be treated with a loop colostomy. Primary resection of unstaged rectal cancer would most likely carry a high CRM positivity rate and cannot be condoned. Where the lesion occupies the distal sigmoid colon the usual practice would be to perform a high anterior resection. The decision surrounding restoration of intestinal continuity would lie with the operating surgeon. References 1. Sagar J. Colorectal stents for the management of malignant colonic obstructions. Cochrane Database of Systematic Reviews 2011, Issue 11. Art. No.: CD007378. DOI: 10.1002/14651858.CD007378.pub2. 2. Cirrochi et al Safety and efficacy of endoscopic colonic stenting as a bridge to surgery in the management of intestinal obstruction due to left colon and rectal cancer: A systematic review and meta-analysis. Surg Oncol. 2013 Mar;22(1):14-21. 3. Johnson W and Hawkins A. Large bowel obstruction. Clin Colon Rectal Surg. 2021 Jul;34(4):233-241. doi: 10.1055/s-0041-1729927.

Answer 1533

These small arterial lesions are a rare cause of bleeding and are characterised by a single large tortuous arteriole in the sub mucosa. Extra gastric lesions may occur. Upper gastrointestinal bleeding Patients may present with the following: Haematemesis and/ or malaena Epigastric discomfort Sudden collapse The extent to which these will occur will depend upon the source. Mortality is higher in patients presenting with haematemesis than malaena alone. Oesophageal bleeding Cause Presenting features Oesophagitis Small volume of fresh blood, often streaking vomit. Malaena rare. Often ceases spontaneously. Usually history of antecedent GORD type symptoms. Cancer Usually small volume of blood, except as pre terminal event with erosion of major vessels. Often associated symptoms of dysphagia and constitutional symptoms such as weight loss. May be recurrent until malignancy managed. Mallory Weiss Tear Typically brisk small to moderate volume of bright red blood following bout of repeated vomiting. Malaena rare. Usually ceases spontaneously. Varices Usually large volume of fresh blood. Swallowed blood may cause malaena. Often associated with haemodynamic compromise. May stop spontaneously but re-bleeds are common until appropriately managed. Gastric Bleeding Cause Presenting features Gastric cancer May be frank haematemesis or altered blood mixed with vomit. Usually prodromal features of dyspepsia and may have constitutional symptoms. Amount of bleeding variable but erosion of major vessel may produce considerable haemorrhage. Dieulafoy Lesion Often no prodromal features prior to haematemesis and malaena, but this arteriovenous malformation may produce quite considerable haemorrhage and may be difficult to detect endoscopically. Diffuse erosive gastritis Usually haematemesis and epigastric discomfort. Usually there is an underlying cause such as recent NSAID usage. Large volume haemorrhage may occur with considerable haemodynamic compromise. Gastric ulcer Small low volume bleeds more common so would tend to present as iron deficiency anaemia. Erosion into a significant vessel may produce considerable haemorrhage and haematemesis. Duodenum Most common cause of major haemorrhage is a posteriorly sited duodenal ulcer. However, ulcers at any site in the duodenum may present with haematemesis, malaena and epigastric discomfort. The pain of duodenal ulcer is slightly different to that of gastric ulcers and often occurs several hours after eating. Peri ampullary tumours may bleed but these are rare. In patients with previous abdominal aortic aneurysm surgery aorto-enteric fistulation remains a rare but important cause of major haemorrhage associated with high mortality. Management Admission to hospital careful monitoring, cross match blood, check FBC, LFTs, U+E and Clotting (as a minimum) Patients with on-going bleeding and haemodynamic instability are likely to require O negative blood pending cross matched blood Early control of airway is vital (e.g. Drowsy patient with liver failure) Patients with suspected varices should receive terlipressin prior to endoscopy Ideally all patients admitted with upper gastrointestinal haemorrhage should undergo Upper GI endoscopy within 24 hours of admission. In those who are unstable this should occur immediately after resuscitation or in tandem with it. The endoscopy department is a potentially dangerous place for unstable patients and it may be safer to perform the endoscopy in theatre with an anaesthetist present. Varices should be banded or subjected to sclerotherapy. If this is not possible owing to active bleeding then a Sengstaken- Blakemore tube (or Minnesota tube) should be inserted. This should be done with care; gastric balloon should be inflated first and oesophageal balloon second. Remember the balloon will need deflating after 12 hours (ideally sooner) to prevent necrosis. Portal pressure should be lowered by combination of medical therapy +/- TIPSS. Patients with erosive oesophagitis / gastritis should receive a proton pump inhibitor. Mallory Weiss tears will typically resolve spontaneously Identifiable bleeding points should receive combination therapy of injection of adrenaline and either a thermal or mechanical treatment. All who have received intervention should receive a continuous infusion of a proton pump inhibitor (IV omeprazole for 72 hours) to reduce the re-bleeding rate. Patients with diffuse erosive gastritis who cannot be managed endoscopically and continue to bleed may require gastrectomy Bleeding ulcers that cannot be controlled endoscopically may require laparotomy and ulcer underruning Indications for surgery Patients > 60 years Continued bleeding despite endoscopic intervention Recurrent bleeding Known cardiovascular disease with poor response to hypotension Surgery Duodenal ulcer Laparotomy, duodenotomy and under running of the ulcer. If bleeding is brisk then the ulcer is almost always posteriorly sited and will have invaded the gastroduodenal artery. Large bites using 0 Vicryl are taken above and below the ulcer base to occlude the vessel. The duodenotomy should be longitudinal but closed transversely to avoid stenosis. For gastric ulcer Under-running of the bleeding site Partial gastrectomy-antral ulcer Partial gastrectomy or under running the ulcer- lesser curve ulcer (involving left gastric artery) Total gastrectomy if bleeding persists Summary of Acute Upper GI bleeding recommendations: The need for admission and timing of endoscopic intervention may be predicted by using the Blatchford score. This considers a patients Hb, serum urea, pulse rate and blood pressure. Those patients with a score of 0 are low risk, all others are considered high risk and require admission and endoscopy. The requirement for pre endoscopic proton pump inhibition is contentious. In the UK the National Institute of Clinical Excellence guidelines suggest the pre endoscopic PPI therapy is unnecessary. Whilst it is accepted that such treatment has no impact on mortality or morbidity a Cochrane review of this practice in 2007 did suggest that it reduced the stigmata of recent haemorrhage at endoscopy. As a result many will still administer PPI to patients prior to endoscopic intervention. Following endoscopy it is important to calculate the Rockall score for patients to determine their risk of rebleeding and mortality. A score of 3 or less is associated with a rebleeding rate of 4% and a very low risk of mortality and identifies a group of patients suitable for early discharge. References 1. http://www.sign.ac.uk/guidelines/fulltext/105/index.html 2. Joint Advisory Group on Endoscopy (JAG) Guidelines - http://www.thejag.org.uk 3. NICE Guideline: Management of acute upper GI bleeding. July 2012.

Answer 1534

8 cm is still within normal limits. However, caecal diameters of 9 and 10 are pathological and should prompt further investigation. Right colon Ileocaecal valve Entry point of the terminal ileum to the caecum An important colonoscopic landmark The ileocaecal valve is not always competent and this may allow partial decompression of an obstructed colon Appendix At the base of the caecum the taenia coalesce to mark the base of the appendix This is a reliable way of locating the appendix surgically and is a constant landmark The appendix has a small mesentery (the mesoappendix) and in this runs the appendiceal artery, a branch of the ileocolic artery. The posterior aspect of the right colon is extra peritoneal and the anterior aspect intraperitoneal. Relations Posterior Iliacus, Iliolumbar ligament, Quadratus lumborum, Transverse abdominis, Diaphragm at the tip of the last rib; Lateral cutaneous, ilioinguinal, and iliohypogastric nerves; the iliac branches of the iliolumbar vessels, the fourth lumbar artery, gonadal vessels, ureter and the right kidney. Superior Right kidney which is embedded in the perinephric fat Medial Mesentery which contains the ileocolic artery that supplies the right colon and terminal ileum. A further branch , the right colic artery, also contributes to supply the hepatic flexure and proximal transverse colon. Medially these pass through the mesentery to join the SMA. This occurs near to the head of the pancreas and care has to be taken when ligating the ileocolic artery near to its origin in cancer cases for fear of impinging on the SMA. - Anterior Coils of small intestine, the right edge of the greater omentum, and the anterior abdominal wall. Nerve supply Parasympathetic fibres of the vagus nerve (CN X) Arterial supply Ileocolic artery and right colic artery, both branches of the SMA. While the ileocolic artery is almost always present, the right colic can be absent in 5-15% of individuals.

Answer 1535

Infection with diphtheria classically causes a systemic illness that lasts several days. The tonsils or pharynx can be covered in a thick grey membrane which bleeds on attempted removal. There is often quite marked cervical adenopathy and some individuals can have a bulls neck appearance. Death can occur through airway compromise, which is why the often described attempted removal of the pseudomembrane so beloved of examiners, is, in practice rather a foolish thing to attempt in a young child! Acute tonsillitis Characterised by pharyngitis, fever, malaise and lymphadenopathy. Over half of all cases are bacterial with Streptococcus pyogenes the most common organism The tonsils are typically oedematous and yellow or white pustules may be present Infectious mononucleosis may mimic the condition. Treatment with penicillin type antibiotics is indicated for bacterial tonsillitis. Bacterial tonsillitis may result in local abscess formation (quinsy)

Answer 1536

The serratus anterior lies medial, the pectoral muscles being related more anteriorly. Long thoracic nerve Derived from ventral rami of C5, C6, and C7 (close to their emergence from intervertebral foramina) It runs downward and passes either anterior or posterior to the middle scalene muscle It reaches upper tip of serratus anterior muscle and descends on outer surface of this muscle, giving branches into it Winging of Scapula occurs in long thoracic nerve injury (most common) or from spinal accessory nerve injury (which denervates the trapezius) or a dorsal scapular nerve injury

Answer 1537

The Breslow thickness has considerable prognostic importance. Lymphocytic infiltrates may be associated with an improved prognosis, but do not carry nearly the same weight as increased thickness. Malignant melanoma The main diagnostic features (major criteria): Change in size Change in shape Change in colour Secondary features (minor criteria) Diameter >6mm Inflammation Oozing or bleeding Altered sensation Treatment Suspicious lesions should undergo excision biopsy. The lesion should be removed in completely as incision biopsy can make subsequent histopathological assessment difficult. Once the diagnosis is confirmed the pathology report should be reviewed to determine whether further re-excision of margins is required (see below): Margins of excision-Related to Breslow thickness Lesions 0-1mm thick 1cm Lesions 1-2mm thick 1- 2cm (Depending upon site and pathological features) Lesions 2-4mm thick 2-3 cm (Depending upon site and pathological features) Lesions >4 mm thick 3cm Marsden J et al Revised UK guidelines for management of Melanoma. Br J Dermatol 2010 163:238-256. Further treatments such as sentinel lymph node mapping, isolated limb perfusion and block dissection of regional lymph node groups should be selectively applied. Guidelines The UK NICE guidance is covered by Melanoma: assessment and management NICE guideline [NG14]. However, the complex oncological regimens are not extensively covered in this guidance though more formal guidance is provided by relevant oncological organisations.

Answer 1538

They are facultative anaerobes and may be difficult to culture. Direct visualisation of organisms and sulphur granules from lesions themselves is the easiest way to make a diagnosis. It remains a differential of conditions such as hydradenitis supprativa, particularly if it is occurring in odd locations and with deeper abscesses than usual. Surgical Microbiology An extensive topic so an overview is given here. Organisms causing common surgical infections are reasonable topics in the examination. However, microbiology is less rigorously tested than anatomy, for example. Common organisms Staphylococcus aureus Facultative anaerobe Gram positive coccus Haemolysis on blood agar plates Catalase positive 20% population are long term carriers Exo and entero toxin may result in toxic shock syndrome and gastroenteritis respectively Ideally treated with penicillin although many strains now resistant through beta Lactamase production. In the UK less than 5% of isolates are sensitive to penicillin. Resistance to methicillin (and other antibiotics) is mediated by the mec operon , essentially penicillin binding protein is altered and resistance to this class of antibiotics ensues Common cause of cutaneous infections and abscesses Streptococcus pyogenes Gram positive, forms chain like colonies, Lancefield Group A Streptococcus Produces beta haemolysis on blood agar plates Rarely part of normal skin microflora Catalase negative Releases a number of proteins/ virulence factors into host including hyaluronidase, streptokinase which allow rapid tissue destruction Releases superantigens such as pyogenic exotoxin A which results in scarlet fever Remains sensitive to penicillin, macrolides may be used as an alternative. Escherichia coli Gram negative rod Facultative anaerobe, non sporing Wide range of subtypes and some are normal gut commensals Some subtypes such as 0157 may produce lethal toxins resulting in haemolytic-uraemic syndrome Enterotoxigenic E-Coli produces an enterotoxin (ST enterotoxin) that results in large volume fluid secretion into the gut lumen (Via cGMP activation) Enteropathogenic E-Coli binds to intestinal cells and cause structural damage, this coupled with a moderate (or in case of enteroinvasive E-Coli significant) invasive component produces enteritis and large volume diarrhoea together with fever. They are resistant to many antibiotics used to treat gram positive infections and acquire resistance rapidly and are recognised as producing beta lactamases Campylobacter jejuni Curved, gram negative, non sporulating bacteria One of the commonest causes of diarrhoea worldwide Produces enteritis which is often diffuse and blood may be passed Remains a differential for right iliac fossa pain with diarrhoea Self limiting infection so antibiotics are not usually advised. However, the quinolones are often rapidly effective. Helicobacter pylori Gram negative, helix shaped rod, microaerophillic Produces hydrogenase that can derive energy from hydrogen released by intestinal bacteria Flagellated and mobile Those carrying the cag A gene may cause ulcers It secretes urease that breaks down gastric urea> Carbon dioxide and ammonia> ammonium>bicarbonate (simplified!) The bicarbonate can neutralise the gastric acid. Usually colonises the gastric antrum and irritates resulting in increased gastrin release and higher levels of gastric acid. These patients will develop duodenal ulcers. In those with more diffuse H-Pylori infection gastric acid levels are lower and ulcers develop by local tissue damage from H-Pylori- these patients get gastric ulcers. Diagnosis may be made by serology (approx. 75% sensitive). Biopsy urease test during endoscopy probably the most sensitive. In patients who are colonised 10-20% risk of peptic ulcer, 1-2% risk gastric cancer, <1% risk MALT lymphoma.

Answer 1539

Rectus abdominis Arises from the pubis. Inserts into 5th, 6th, 7th costal cartilages. The muscle lies in the rectal sheath, which also contains the superior and inferior epigastric artery and vein. Action: flexion of thoracic and lumbar spine. Nerve supply: anterior primary rami of T7-12. The aponeurosis is deficient below the arcuate line. Abdominal wall The 2 main muscles of the abdominal wall are the rectus abdominis (anterior) and the quadratus lumborum (posterior). The remaining abdominal wall consists of 3 muscular layers. Each muscle passes from the lateral aspect of the quadratus lumborum posteriorly to the lateral margin of the rectus sheath anteriorly. Each layer is muscular posterolaterally and aponeurotic anteriorly. Muscles of abdominal wall External oblique Lies most superficially Originates from 5th to 12th ribs Inserts into the anterior half of the outer aspect of the iliac crest, linea alba and pubic tubercle More medially and superiorly to the arcuate line, the aponeurotic layer overlaps the rectus abdominis muscle The lower border forms the inguinal ligament The triangular expansion of the medial end of the inguinal ligament is the lacunar ligament. Internal oblique Arises from the thoracolumbar fascia, the anterior 2/3 of the iliac crest and the lateral 2/3 of the inguinal ligament The muscle sweeps upwards to insert into the cartilages of the lower 3 ribs The lower fibres form an aponeurosis that runs from the tenth costal cartilage to the body of the pubis At its lowermost aspect it joins the fibres of the aponeurosis of transversus abdominis to form the conjoint tendon. Transversus abdominis Innermost muscle Arises from the inner aspect of the costal cartilages of the lower 6 ribs , from the anterior 2/3 of the iliac crest and lateral 1/3 of the inguinal ligament Its fibres run horizontally around the abdominal wall ending in an aponeurosis. The upper part runs posterior to the rectus abdominis. Lower down the fibres run anteriorly only. The rectus abdominis lies medially; running from the pubic crest and symphysis to insert into the xiphoid process and 5th, 6th and 7th costal cartilages. The muscles lies in a aponeurosis as described above. Nerve supply: anterior primary rami of T7-12 Surgical notes During abdominal surgery it is usually necessary to divide either the muscles or their aponeuroses. During a midline laparotomy it is desirable to divide the aponeurosis. This will leave the rectus sheath intact above the arcuate line and the muscles intact below it. Straying off the midline will often lead to damage to the rectus muscles, particularly below the arcuate line where they may often be in close proximity to each other.

Answer 1540

The patient is likely to have a teratoma which has metastasized to the supraclavicular nodes. There is suspicion of spread to the para-aortic nodes due to the abdominal pain. He will need orchidectomy and combination chemotherapy. There is no role for orchidectomy via scrotal approach in malignancy. Scrotal swelling Differential diagnosis Inguinal hernia If inguinoscrotal swelling; cannot 'get above it' on examination Cough impulse may be present May be reducible Testicular tumours Often discrete testicular nodule (may have associated hydrocele) Symptoms of metastatic disease may be present USS scrotum and serum AFP and β HCG required Acute epididymo-orchitis Often history of dysuria and urethral discharge Swelling may be tender and eased by elevating testis Most cases due to Chlamydia Infections with other gram negative organisms may be associated with underlying structural abnormality Epididymal cysts Single or multiple cysts May contain clear or opalescent fluid (spermatoceles) Usually occur over 40 years of age Painless Lie above and behind testis It is usually possible to 'get above the lump' on examination Hydrocele Non painful, soft fluctuant swelling Often possible to 'get above it' on examination Usually contain clear fluid Will often transilluminate May be presenting feature of testicular cancer in young men Testicular torsion Severe, sudden onset testicular pain Risk factors include abnormal testicular lie Typically affects adolescents and young males On examination testis is tender and pain not eased by elevation Urgent surgery is indicated, the contra lateral testis should also be fixed Varicocele Varicosities of the pampiniform plexus Typically occur on left (because testicular vein drains into renal vein) May be presenting feature of renal cell carcinoma Affected testis may be smaller and bilateral varicoceles may affect fertility Management Testicular malignancy is always treated with orchidectomy via an inguinal approach. This allows high ligation of the testicular vessels and avoids exposure of another lymphatic field to the tumour. Torsion is commonest in young teenagers and the history in older children can be difficult to elicit. Intermittent torsion is a recognised problem. The treatment is prompt surgical exploration and testicular fixation. This can be achieved using sutures or by placement of the testis in a Dartos pouch. Varicoceles are usually managed conservatively. If there are concerns about testicular function of infertility then surgery or radiological management can be considered. Epididymal cysts can be excised using a scrotal approach Hydroceles are managed differently in children where the underlying pathology is a patent processus vaginalis and therefore an inguinal approach is used in children so that the processus can be ligated. In adults a scrotal approach is preferred and the hydrocele sac excised or plicated.

Answer 1541

Entamoeba histiolytica is the only agent on the list that would produce an amoebic abscess. Benign liver lesions Benign liver lesions Haemangioma Most common benign tumours of mesenchymal origin Incidence in autopsy series is 8% Cavernous haemangiomas may be enormous Clinically they are reddish purple hypervascular lesions Lesions are normally separated from normal liver by ring of fibrous tissue On ultrasound they are typically hyperechoic Liver cell adenoma 90% develop in women in their third to fifth decade Linked to use of oral contraceptive pill Lesions are usually solitary They are usually sharply demarcated from normal liver although they usually lack a fibrous capsule On ultrasound the appearances are of mixed echoity and heterogeneous texture. On CT most lesions are hypodense when imaged prior to administration of IV contrast agents In patients with haemorrhage or symptoms removal of the adenoma may be required Mesenchymal hamartomas Congential and benign, usually present in infants. May compress normal liver Liver abscess Biliary sepsis is a major predisposing factor Structures drained by the portal venous system form the second largest source Common symptoms include fever, right upper quadrant pain. Jaundice may be seen in 50% Ultrasound will usually show a fluid filled cavity, hyperechoic walls may be seen in chronic abscesses Amoebic abscess Liver abscess is the most common extra intestinal manifestation of amoebiasis Between 75 and 90% lesions occur in the right lobe Presenting complaints typically include fever and right upper quadrant pain Ultrasonography will usually show a fluid filled structure with poorly defined boundaries Aspiration yield sterile odourless fluid which has an anchovy paste consistency Treatment is with metronidazole Hyatid cysts Seen in cases of Echinococcus infection Typically an intense fibrotic reaction occurs around sites of infection The cyst has no epithelial lining Cysts are commonly unilocular and may grow to 20cm in size. The cyst wall is thick and has an external laminated hilar membrane and an internal enucleated germinal layer Typically presents with malaise and right upper quadrant pain. Secondary bacterial infection occurs in 10%. Liver function tests are usually abnormal and eosinophilia is present in 33% cases Ultrasound may show septa and hyatid sand or daughter cysts. Percutaneous aspiration was previously contra indicated, it is now incorporated into some treatment regimens Treatment is by sterilisation of the cyst with mebendazole and may be followed by surgical resection. Hypertonic swabs are packed around the cysts during surgery Polycystic liver disease Usually occurs in association with polycystic kidney disease Autosomal dominant disorder Symptoms may occur as a result of capsular stretch Cystadenoma Rare lesions with malignant potential Usually solitary multiloculated lesions Liver function tests usually normal Ultrasonography typically shows a large anechoic, fluid filled area with irregular margins. Internal echos may result from septa Surgical resection is indicated in all cases

Answer 1542

Osteomalacia low: calcium, phosphate raised: alkaline phosphatase The low calcium and phosphate combined with the raised alkaline phosphatase point towards osteomalacia.

Answer 1543

The marginal mandibular nerve lies deep to platysma. It supplies the depressor anguli oris and the depressor labii inferioris. If injured it may lead to facial asymmetry and dribbling. Submandibular gland Relations of the submandibular gland Superficial Platysma, deep fascia and mandible Submandibular lymph nodes Facial vein (facial artery near mandible) Marginal mandibular nerve Cervical branch of the facial nerve Deep Facial artery (inferior to the mandible) Mylohyoid muscle Sub mandibular duct Hyoglossus muscle Lingual nerve Submandibular ganglion Hypoglossal nerve Submandibular duct (Wharton's duct) Opens lateral to the lingual frenulum on the anterior floor of mouth. 5 cm length Lingual nerve wraps around Wharton's duct. As the duct passes forwards it crosses medial to the nerve to lie above it and then crosses back, lateral to it, to reach a position below the nerve. Innervation Sympathetic innervation- Derived from superior cervical ganglion Parasympathetic innervation- Submandibular ganglion via lingual nerve Arterial supply Branch of the facial artery. The facial artery passes through the gland to groove its deep surface. It then emerges onto the face by passing between the gland and the mandible. Venous drainage Anterior facial vein (lies deep to the Marginal Mandibular nerve) Lymphatic drainage Deep cervical and jugular chains of nodes

Answer 1544

Small cell carcinoma is often associated with disseminated disease at presentation in the majority of cases. Most cases occur in the main airways and paraneoplastic features are common. Lung cancer Lung cancers may be classified according to histological subtypes. The main distinction is between small cell and non small cell lung cancer. Non small cell lung cancer is the most common variant and accounts for 80% of all lung cancers. Non small cell lung cancer These share common features of prognosis and management. They comprise the following tumours: Squamous cell carcinoma (25% cases) Adenocarcinoma (40% cases) Large cell carcinoma (10% cases) Paraneoplastic features and early disease dissemination are less likely than with small cell lung carcinoma. Adenocarcinoma is the most common lung cancer type encountered in never smokers. Small cell lung carcinoma Small cell lung carcinomas are comprised of cells with a neuro endocrine differentiation. The neuroendocrine hormones may be released from these cells with a wide range of paraneoplastic associations. These tumours are strongly associated with smoking and will typically arise in the larger airways. They disseminate early in the course of the disease and although they are usually chemosensitive this seldom results in long lasting remissions.

Answer 1545

This will address the acute sepsis and resolve the situation. Attempts at completing the surgery at this stage, even in expert hands carries a very high risk of bile duct injury. Do not confuse cholecystostomy with cholecystectomy. Biliary disease Diagnosis Typical features Pathogenesis Gallstones Typically history of biliary colic or episodes of chlolecystitis. Obstructive type history and test results. Usually small calibre gallstones which can pass through the cystic duct. In Mirizzi syndrome the stone may compress the bile duct directly- one of the rare times that cholecystitis may present with jaundice Cholangitis Usually obstructive and will have Charcot's triad of symptoms (pain, fever, jaundice) Ascending infection of the bile ducts usually by E. coli and by definition occurring in a pool of stagnant bile. Pancreatic cancer Typically painless jaundice with palpable gallbladder (Courvoisier's Law) Direct occlusion of distal bile duct or pancreatic duct by tumour. Sometimes nodal disease at the portal hepatis may be the culprit in which case the bile duct may be of normal calibre. TPN (total parenteral nutrition) associated jaundice Usually follows long term use and is usually painless with non obstructive features Often due to hepatic dysfunction and fatty liver which may occur with long term TPN usage. Bile duct injury Depending upon the type of injury may be of sudden or gradual onset and is usually of obstructive type Often due to a difficult laparoscopicÂ cholecystectomy when anatomy in Calots triangle is not appreciated. In the worst scenario the bile duct is excised and jaundice develops rapidly post operatively. More insidious is that of bile duct stenosis which may be caused by clips or diathermy injury. Cholangiocarcinoma Gradual onset obstructive pattern Direct occlusion by disease and also extrinsic compression by nodal disease at the porta hepatis. Septic surgical patient Usually hepatic features Combination of impaired biliary excretion and drugs such as ciprofloxacin which may cause cholestasis. Metastatic disease Mixed hepatic and post hepatic Combination of liver synthetic failure (late) and extrinsic compression by nodal disease and anatomical compression of intra hepatic structures (earlier)

Answer 1546

This man is likely to have underlying chronic mesenteric vascular disease. Only 15% of emboli will occlude SMA orifice leading to entire small bowel infarct. The background history of weight loss also favors an acute on chronic event. Mesenteric vessel disease Mesenteric ischaemia accounts for 1 in 1000 acute surgical admissions. It is primarily caused by arterial embolism resulting in infarction of the colon. It is more likely to occur in areas such as the splenic flexure that are located at the borders of the territory supplied by the superior and inferior mesenteric arteries. Types Acute mesenteric embolus (commonest 50%) Sudden onset abdominal pain followed by profuse diarrhoea. May be associated with vomiting. Rapid clinical deterioration. Serological tests: WCC, lactate, amylase may all be abnormal particularly in established disease. These can be normal in the early phases. Acute on chronic mesenteric ischaemia Usually longer prodromal history. Post prandial abdominal discomfort and weight loss are dominant features. Patients will usually present with an acute on chronic event, but otherwise will tend not to present until mesenteric flow is reduced by greater than 80%. When acute thrombosis occurs presentation may be as above. In the chronic setting the symptoms will often be those of ischaemic colitis (mucosa is the most sensitive area to this insult). Mesenteric vein thrombosis Usually a history over weeks. Overt abdominal signs and symptoms will not occur until venous thrombosis has reached a stage to compromise arterial inflow. Thrombophilia accounts for 60% of cases. Low flow mesenteric infarction This occurs in patients with multiple co morbidities in whom mesenteric perfusion is significantly compromised by overuse of inotropes or background cardiovascular compromise. The end result is that the bowel is not adequately perfused and infarcts occur from the mucosa outwards. Diagnosis Serological tests: WCC, lactate, CRP, amylase (can be normal in early disease). Cornerstone for diagnosis of arterial AND venous mesenteric disease is CT angiography scanning in the arterial phase with thin slices (<5mm). Venous phase contrast is not helpful. SMA duplex USS is useful in the evaluation of proximal SMA disease in patients with chronic mesenteric ischaemia. MRI is of limited use due to gut peristalsis and movement artefact. Management Overt signs of peritonism: Laparotomy Mesenteric vein thrombosis: If no peritonism: Medical management with IV heparin At operation limited resection of frankly necrotic bowel with view to relook laparotomy at 24-48h. In the interim urgent bowel revascularisation via endovascular (preferred) or surgery. Prognosis Overall poor. Best outlook is from an acute ischaemia from an embolic event where surgery occurs within 12h. Survival may be 50%. This falls to 30% with treatment delay. The other conditions carry worse survival figures.

Answer 1547

Anaesthetic agents, such as suxamethonium, can cause malignant hyperthermia in patients with a genetic defect. Acute dystonic reaction normally is associated with antipsychotics (haloperidol) and metoclopramide. These lead to marked extrapyramidal effects. Serotonin syndrome is associated with the antidepressants selective serotonin reuptake inhibitors (SSRIs) and selective serotonin/norepinephrine reuptake inhibitors (SSNRIs). This causes a syndrome of agitation, tachycardia, hallucinations and hyper-reflexia. Malignant hyperthermia Overview Condition seen following administration of anaesthetic agents ( rate of 1 in 15,000) Characterised by hyperpyrexia and muscle rigidity Cause by excessive release of Ca2+ from the sarcoplasmic reticulum of skeletal muscle Associated with defects in a gene on chromosome 19 encoding the ryanodine receptor, which controls Ca2+ release from the sarcoplasmic reticulum Neuroleptic malignant syndrome may have a similar aetiology Causative agents Halothane Suxamethonium Other drugs: antipsychotics (neuroleptic malignant syndrome) Investigations CK raised Contracture tests with halothane and caffeine Management Dantrolene - prevents Ca2+ release from the sarcoplasmic reticulum

Answer 1548

Although many cell types may give rise to giant cells, macrophages remain the most common. Although many cell types may give rise to giant cells, macrophages remain the most common. Giant cells A giant cell is a mass formed by the union of several distinct types of cells They are most commonly comprised of macrophages They are different to granulomas although causative agents may overlap

Answer 1549

Renin does not cause vasoconstriction. Angiotensin I is biologically inactive. Aldosterone will increase blood pressure but does not have direct vasospastic effects. Shock - Shock occurs when there is insufficient tissue perfusion. The pathophysiology of shock is an important surgical topic and may be divided into the following aetiological groups: Septic Haemorrhagic Neurogenic Cardiogenic Anaphylactic Septic shock Septic shock is a major problem and those patients with severe sepsis have a mortality rate in excess of 40%. In those who are admitted to intensive care mortality ranges from 6% with no organ failure to 65% in those with 4 organ failure. Sepsis is defined as an infection that triggers a particular Systemic Inflammatory Response Syndrome (SIRS). In 2016, the European Society of Intensive Care Medicine and the Society of Critical Care Medicine (SCCM) created a task force that proposed Sepsis-3, a new definition for sepsis. The new definition excluded the establishment of SIRS criteria to define sepsis and made it more nonspecific as any life-threatening organ dysfunction caused by the dysregulated host response to infection. The task force claimed that sequential organ failure assessment (SOFA) has a better predictive validity for sepsis than SIRS criteria. It has better prognostic accuracy and the ability to predict in-hospital mortality. To reduce the complexity of calculating the SOFA, they introduced q SOFA Q SOFA 3 component assessment system with: Systolic blood pressure below 100 mm Hg Highest respiratory rate exceeding 21 Lowest Glasgow coma score is under 15 Although the validity of q SOFA is limited in an ICU setting, it has consistently outperformed SIRS criteria in predicting organ dysfunction in a non-ICU and ER setting. The use of vasopressors, mechanical ventilation, and aggressive therapeutic interventions in ICU limit the efficacy of q SOFA. During the septic process there is marked activation of the immune system with extensive cytokine release. This may be coupled with or triggered by systemic circulation of bacterial toxins. These all cause endothelial cell damage and neutrophil adhesion. The overall hallmarks are thus those of excessive inflammation, coagulation and fibrinolytic suppression. The main management issues with severe infections resulting in organ dysfunction are as follows: Prompt administration of antibiotics to cover all likely pathogens coupled with a rigorous search for the source of infection. Haemodynamic stabilisation. Many patients are hypovolaemic and require aggressive fluid administration. Aim for CVP 8-12 cm H2O, MAP >65mmHg. Modulation of the septic response. This includes manoeuvres to counteract the changes and includes measures such as tight glycaemic control. The routine use of steroids is not advised. In surgical patients, the main groups with septic shock include those with anastomotic leaks, abscesses and extensive superficial infections such as necrotising fasciitis. When performing surgery the aim should be to undertake the minimum necessary to restore physiology. These patients do not fare well with prolonged surgery. Definitive surgery can be more safely undertaken when physiology is restored and clotting in particular has been normalised. Haemorrhagic shock The average adult blood volume comprises 7% of body weight. Thus in the 70 Kg adult this will equate to 5 litres. This changes in children (8-9% body weight) and is slightly lower in the elderly. The table below outlines the 4 major classes of haemorrhagic shock and their associated physiological sequelae: Parameter Class I Class II Class III Class IV Blood loss ml <750ml 750-1500ml 1500-2000ml >2000ml Blood loss % <15% 15-30% 30-40% >40% Pulse rate <100 >100 >120 >140 Blood pressure Normal Normal Decreased Decreased Respiratory rate 14-20 20-30 30-40 >35 Urine output >30ml 20-30ml 5-15ml <5ml Symptoms Normal Anxious Confused Lethargic Decreasing blood pressure during haemorrhagic shock causes organ hypoperfusion and relative myocardial ischaemia. The cardiac index gives a numerical value for tissue oxygen delivery and is given by the equation: Cardiac index= Cardiac output/ body surface area. Where Hb is haemoglobin concentration in blood and SaO2 the saturation and PaO2 the partial pressure of oxygen. Detailed knowledge of this equation is required for the MRCS Viva but not for part A, although you should understand the principle. In patients suffering from trauma the most likely cause of shock is haemorrhage. However, the following may also be the cause or occur concomitantly: Tension pneumothorax Spinal cord injury Myocardial contusion Cardiac tamponade When assessing trauma patients it is worth remembering that in order to generate a palpable femoral pulse an arterial pressure of >65mmHg is required. Once bleeding is controlled and circulating volume normalised the levels of transfusion should be to maintain a Hb of 7-8 in those with no risk factors for tissue hypoxia and Hb 10 for those who have such risk factors. Neurogenic shock This occurs most often following a spinal cord transection, usually at a high level. There is resultant interruption of the autonomic nervous system. The result is either decreased sympathetic tone or increased parasympathetic tone, the effect of which is a decrease in peripheral vascular resistance mediated by marked vasodilation. This results in decreased preload and thus decreased cardiac output (Starlings law). There is decreased peripheral tissue perfusion and shock is thus produced. In contrast with many other types of shock peripheral vasoconstrictors are used to return vascular tone to normal. Cardiogenic shock In medical patients the main cause is ischaemic heart disease. In the traumatic setting direct myocardial trauma or contusion is more likely. Evidence of ECG changes and overlying sternal fractures or contusions should raise the suspicion of injury. Treatment is largely supportive and transthoracic echocardiography should be used to determine evidence of pericardial fluid or direct myocardial injury. The measurement of troponin levels in trauma patients may be undertaken but they are less useful in delineating the extent of myocardial trauma than following MI. When cardiac injury is of a blunt nature and is associated with cardiogenic shock the right side of the heart is the most likely site of injury with chamber and or valve rupture. These patients require surgery to repair these defects and will require cardiopulmonary bypass to achieve this. Some may require intra aortic balloon pump as a bridge to surgery. Anaphylactic shock Anaphylaxis may be defined as a severe, life-threatening, generalised or systemic hypersensitivity reaction. Anaphylaxis is one of the few times when you would not have time to look up the dose of a medication. The Resuscitation Council guidelines on anaphylaxis have recently been updated. Adrenaline is by far the most important drug in anaphylaxis and should be given as soon as possible. The recommended doses for adrenaline, hydrocortisone and chlorpheniramine (if one wishes to use them) are as follows: Adrenaline Hydrocortisone Chlorpheniramine < 6 months 150 mcg (0.15ml 1 in 1,000) 25 mg 250 mcg/kg 6 months - 6 years 150 mcg (0.15ml 1 in 1,000) 50 mg 2.5 mg 6-12 years 300 mcg (0.3ml 1 in 1,000) 100 mg 5 mg Adult and child 12 years 500 mcg (0.5ml 1 in 1,000) 200 mg 10 mg Adrenaline can be repeated every 5 minutes if necessary. The best site for IM injection is the anterolateral aspect of the middle third of the thigh. Common identified causes of anaphylaxis food (e.g. Nuts) - the most common cause in children drugs venom (e.g. Wasp sting)

Answer 1550

Renin does not cause vasoconstriction. Angiotensin I is biologically inactive. Aldosterone will increase blood pressure but does not have direct vasospastic effects. Shock - Shock occurs when there is insufficient tissue perfusion. The pathophysiology of shock is an important surgical topic and may be divided into the following aetiological groups: Septic Haemorrhagic Neurogenic Cardiogenic Anaphylactic Septic shock Septic shock is a major problem and those patients with severe sepsis have a mortality rate in excess of 40%. In those who are admitted to intensive care mortality ranges from 6% with no organ failure to 65% in those with 4 organ failure. Sepsis is defined as an infection that triggers a particular Systemic Inflammatory Response Syndrome (SIRS). In 2016, the European Society of Intensive Care Medicine and the Society of Critical Care Medicine (SCCM) created a task force that proposed Sepsis-3, a new definition for sepsis. The new definition excluded the establishment of SIRS criteria to define sepsis and made it more nonspecific as any life-threatening organ dysfunction caused by the dysregulated host response to infection. The task force claimed that sequential organ failure assessment (SOFA) has a better predictive validity for sepsis than SIRS criteria. It has better prognostic accuracy and the ability to predict in-hospital mortality. To reduce the complexity of calculating the SOFA, they introduced q SOFA Q SOFA 3 component assessment system with: Systolic blood pressure below 100 mm Hg Highest respiratory rate exceeding 21 Lowest Glasgow coma score is under 15 Although the validity of q SOFA is limited in an ICU setting, it has consistently outperformed SIRS criteria in predicting organ dysfunction in a non-ICU and ER setting. The use of vasopressors, mechanical ventilation, and aggressive therapeutic interventions in ICU limit the efficacy of q SOFA. During the septic process there is marked activation of the immune system with extensive cytokine release. This may be coupled with or triggered by systemic circulation of bacterial toxins. These all cause endothelial cell damage and neutrophil adhesion. The overall hallmarks are thus those of excessive inflammation, coagulation and fibrinolytic suppression. The main management issues with severe infections resulting in organ dysfunction are as follows: Prompt administration of antibiotics to cover all likely pathogens coupled with a rigorous search for the source of infection. Haemodynamic stabilisation. Many patients are hypovolaemic and require aggressive fluid administration. Aim for CVP 8-12 cm H2O, MAP >65mmHg. Modulation of the septic response. This includes manoeuvres to counteract the changes and includes measures such as tight glycaemic control. The routine use of steroids is not advised. In surgical patients, the main groups with septic shock include those with anastomotic leaks, abscesses and extensive superficial infections such as necrotising fasciitis. When performing surgery the aim should be to undertake the minimum necessary to restore physiology. These patients do not fare well with prolonged surgery. Definitive surgery can be more safely undertaken when physiology is restored and clotting in particular has been normalised. Haemorrhagic shock The average adult blood volume comprises 7% of body weight. Thus in the 70 Kg adult this will equate to 5 litres. This changes in children (8-9% body weight) and is slightly lower in the elderly. The table below outlines the 4 major classes of haemorrhagic shock and their associated physiological sequelae: Parameter Class I Class II Class III Class IV Blood loss ml <750ml 750-1500ml 1500-2000ml >2000ml Blood loss % <15% 15-30% 30-40% >40% Pulse rate <100 >100 >120 >140 Blood pressure Normal Normal Decreased Decreased Respiratory rate 14-20 20-30 30-40 >35 Urine output >30ml 20-30ml 5-15ml <5ml Symptoms Normal Anxious Confused Lethargic Decreasing blood pressure during haemorrhagic shock causes organ hypoperfusion and relative myocardial ischaemia. The cardiac index gives a numerical value for tissue oxygen delivery and is given by the equation: Cardiac index= Cardiac output/ body surface area. Where Hb is haemoglobin concentration in blood and SaO2 the saturation and PaO2 the partial pressure of oxygen. Detailed knowledge of this equation is required for the MRCS Viva but not for part A, although you should understand the principle. In patients suffering from trauma the most likely cause of shock is haemorrhage. However, the following may also be the cause or occur concomitantly: Tension pneumothorax Spinal cord injury Myocardial contusion Cardiac tamponade When assessing trauma patients it is worth remembering that in order to generate a palpable femoral pulse an arterial pressure of >65mmHg is required. Once bleeding is controlled and circulating volume normalised the levels of transfusion should be to maintain a Hb of 7-8 in those with no risk factors for tissue hypoxia and Hb 10 for those who have such risk factors. Neurogenic shock This occurs most often following a spinal cord transection, usually at a high level. There is resultant interruption of the autonomic nervous system. The result is either decreased sympathetic tone or increased parasympathetic tone, the effect of which is a decrease in peripheral vascular resistance mediated by marked vasodilation. This results in decreased preload and thus decreased cardiac output (Starlings law). There is decreased peripheral tissue perfusion and shock is thus produced. In contrast with many other types of shock peripheral vasoconstrictors are used to return vascular tone to normal. Cardiogenic shock In medical patients the main cause is ischaemic heart disease. In the traumatic setting direct myocardial trauma or contusion is more likely. Evidence of ECG changes and overlying sternal fractures or contusions should raise the suspicion of injury. Treatment is largely supportive and transthoracic echocardiography should be used to determine evidence of pericardial fluid or direct myocardial injury. The measurement of troponin levels in trauma patients may be undertaken but they are less useful in delineating the extent of myocardial trauma than following MI. When cardiac injury is of a blunt nature and is associated with cardiogenic shock the right side of the heart is the most likely site of injury with chamber and or valve rupture. These patients require surgery to repair these defects and will require cardiopulmonary bypass to achieve this. Some may require intra aortic balloon pump as a bridge to surgery. Anaphylactic shock Anaphylaxis may be defined as a severe, life-threatening, generalised or systemic hypersensitivity reaction. Anaphylaxis is one of the few times when you would not have time to look up the dose of a medication. The Resuscitation Council guidelines on anaphylaxis have recently been updated. Adrenaline is by far the most important drug in anaphylaxis and should be given as soon as possible. The recommended doses for adrenaline, hydrocortisone and chlorpheniramine (if one wishes to use them) are as follows: Adrenaline Hydrocortisone Chlorpheniramine < 6 months 150 mcg (0.15ml 1 in 1,000) 25 mg 250 mcg/kg 6 months - 6 years 150 mcg (0.15ml 1 in 1,000) 50 mg 2.5 mg 6-12 years 300 mcg (0.3ml 1 in 1,000) 100 mg 5 mg Adult and child 12 years 500 mcg (0.5ml 1 in 1,000) 200 mg 10 mg Adrenaline can be repeated every 5 minutes if necessary. The best site for IM injection is the anterolateral aspect of the middle third of the thigh. Common identified causes of anaphylaxis food (e.g. Nuts) - the most common cause in children drugs venom (e.g. Wasp sting)

Answer 1551

The glossopharyngeal nerve supplies the taste and general sensation to the posterior third of the tongue. Tongue The tongue is a muscular organ concerned with both feeding and speech. It is shaped like an inverted boot with a root through which extrinsic muscles pass to attach it to the soft palate, the styloid process, the hyoid bone and the mandible. It has a body that comprises muscle intermingled with lingual salivary glands, connective tissue, nerves, vessels and lymphatic follicles. The dorsum of the tongue is divided by an ill defined V shaped groove, the sulcus terminalis, into an anterior two thirds and a posterior third. The arterial blood supply to the tongue is from the paired sets of lingual arteries that arise from the external carotid. The venous drainage is via dorsal lingual veins which then join the lingual veins and eventually into the sublingual vein. The nerve supply is as follows: The lingual branch of the mandibular division of the trigeminal nerve supplies common sensation to the anterior two thirds The chorda tympani branch of the facial nerve supplies taste to the anterior two thirds The lingual branch of the glossopharyngeal nerve supplies common sensation and taste to the posterior third of the tongue All intrinsic muscles of the tongue are supplied by the hypoglossal nerve

Answer 1552

D-pH 7.32, PCO2 3.8, PaO2 22.2 (FiO2 40%), Bicarbonate 19.1, Base excess -7.9 Arterial blood gas interpretation In advanced life support training, a 5 step approach to arterial blood gas interpretation is advocated. 1. How is the patient? 2. Is the patient hypoxaemic? The Pa02 on air should be 10.0-13.0 kPa 3. Is the patient acidaemic (pH <7.35) or alkalaemic (pH >7.45) 4. What has happened to the PaCO2? If there is acidaemia, an elevated PaCO2 will account for this 5. What is the bicarbonate level or base excess? A metabolic acidosis will have a low bicarbonate level and a low base excess (< -2 mmol) A metabolic alkalosis will have a high bicarbonate and a high base excess (> +2 mmol)

Answer 1553

She has most likely developed hypocalcaemic tetany and will require immediate calcium supplementation. Complications following thyroid surgery The major immediate risk following thyroidectomy is haemorrhage. A tension haematoma deep to the cervical fascia is usually the result of reactionary haemorrhage from an arterial source. This results in the development of laryngeal oedema and airway compromise. The treatment is by urgent wound decompression of all layers prior to return to theatre for haemostasis. Sub cutnaeous haematomas and seromas may accumulate under skin flaps and can often be managed conservatively or by simple aspiration. In patients with longstanding large goitres there is the risk of tracheomalacia. This is characterised by the development of flacidity of the tracheal cartilage. This can result in airway compromise. In the normal situation the tracheal diameter increases slightly during inspiration and narrows during expiration. In tracheomalacia these processes are exaggerated and the trachea may collapse in expiration resulting in stridor. In the immediate situation an endotracheal tube will need to be inserted. Recurrent laryngeal nerve injury is recognised following thyroid surgery and may be unilateral or bilateral depending upon the procedure performed. The risk is 1.8% at one month which declines to 0.5% at three months following first time explorations. It is rare for nerve injury alone to result in airway compromise. However, it may occur when nerve injury is associated with minor degrees of laryngeal oedema (such as following intubation). Hypoparathyroidism is a recognised complication following thyroid surgery and damage to the blood supply to the parathyroid glands is probably the commonest cause. The incidence of permanent hypoparathyroidism is in the region of 1 to 3%. It can present dramatically in the first 2-5 post operative days. In the emergency setting treatment is with intravenous calcium gluconate. Oral calcium carbonate is used in the longer term.

Answer 1554

Papillary thyroid cancers are the most common type of thyroid cancer and are the more common in females (M:F=1:3). Papillary tumours are more likely to develop lymphatic spread than follicular tumours. Thyroid disease Patients may present with a number of different manifestations of thyroid disease. They can be broadly sub classified according to whether they are euthyroid or have clinical signs of thyroid dysfunction. In addition it needs to be established whether they have a mass or not. Assessment History Examination including USS If a nodule is identified then it should be sampled ideally via an image guided fine needle aspiration Radionucleotide scanning is of limited use Thyroid Tumours Papillary carcinoma Follicular carcinoma Anaplastic carcinoma Medullary carcinoma Lymphoma's Multinodular goitre One of the most common reasons for presentation Provided the patient is euthyroid and asymptomatic and no discrete nodules are seen, they can be reassured. In those with compressive symptoms surgery is required and the best operation is a total thyroidectomy. Sub total resections were practised in the past and simply result in recurrent disease that requires a difficult revisional resection. Endocrine dysfunction In general these patients are managed by physicians initially. Surgery may be offered alongside radio iodine for patients with Graves disease that fails with medical management or in patients who would prefer not to be irradiated (e.g. pregnant women). Patients with hypothyroidism do not generally get offered a thyroidectomy. Sometimes people inadvertently get offered resections during the early phase of Hashimotos thyroiditis, however, with time the toxic phase passes and patients can simply be managed with thyroxine. Complications following surgery Anatomical such as recurrent laryngeal nerve damage. Bleeding. Owing to the confined space haematoma's may rapidly lead to respiratory compromise owing to laryngeal oedema. Damage to the parathyroid glands resulting in hypocalcaemia. Further sources of information 1. http://www.acb.org.uk/docs/TFTguidelinefinal.pdf- Association of Clinical Biochemistry guidelines for thyroid function tests. 2. British association of endocrine surgeons website- http://www.baets.org.uk

Answer 1555

Antibiotics: mechanism of action The lists below summarise the site of action of the commonly used antibiotics Inhibit cell wall formation penicillins cephalosporins Inhibit protein synthesis aminoglycosides (cause misreading of mRNA) chloramphenicol macrolides (e.g. erythromycin) tetracyclines fusidic acid Inhibit DNA synthesis quinolones (e.g. ciprofloxacin) metronidazole sulphonamides trimethoprim Inhibit RNA synthesis rifampicin

Answer 1556

Even after correction for the low albumin level this patient has significant hypocalcaemia which should be corrected. Both calcium chloride and gluconate can be used. Currently, gluconate is the favored agent. Hypocalcaemia: causes and management The clinical history combined with parathyroid hormone levels will reveal the cause of hypocalcaemia in the majority of cases Causes Vitamin D deficiency (osteomalacia) Acute pancreatitis Chronic renal failure Hypoparathyroidism (e.g. post thyroid/parathyroid surgery) Pseudohypoparathyroidism (target cells insensitive to PTH) Rhabdomyolysis (initial stages) Magnesium deficiency (due to end organ PTH resistance) Management Acute management of severe hypocalcaemia is with intravenous replacement. The preferred method is with intravenous calcium gluconate, 10ml of 10% solution over 10 minutes ECG monitoring is recommended Further management depends on the underlying cause Calcium and bicarbonate should not be administered via the same route

Answer 1557

A midline cystic mass of an infant in this age group is most likely to be a bronchogenic cyst. Hiatus hernia is unusual in the neonatal period. Oesophageal duplication cysts are very rare and respiratory symptoms are less common than with bronchogenic cysts. Midline congenital hernias are rare and would usually not include an air/ fluid level in the rare event that they occur at this site. Bronchogenic cysts Overview Bronchogenic cysts most commonly arise as a result of anomalous development of the ventral foregut. They are most commonly single, although multiple cysts are described. They often lie near the midline and most frequently occur in the region of the carina. They may be attached to the tracheobronchial tree, although they are seldom in direct connection with it. Cases may be asymptomatic or present with respiratory symptoms early in the neonatal period. They are the second most common type of foregut cysts (after enterogenous cysts) in the middle mediastinum. Up to 50% of cases are diagnosed prior to 15 years of age. Investigation Many cases are diagnosed on antenatal ultrasound. Others may be detected on conventional chest radiography as a midline spherical mass or cystic structure. Once the diagnosis is suspected a CT scan should be performed. Treatment Thorascopic resection is the ideal treatment. Very young babies can be operated on once they reach six weeks of age.

Answer 1558

This is one variant of a below knee amputation. The Burgess flap is the other commonly practised approach. Amputations Amputations are indicated when the affected limb is one of the following: Dead non viable Deadly where it is posing a major threat to life Dead useless where it is viable but a prosthesis would be preferable Orthopaedic surgery Amputation is often undertaken as an option of last resort e.g. Limb salvage has failed and the limb is so non functional that mobility needs would be best met with prosthesis. Chronic fracture non union or significant limb shortening following trauma would fit into this category. Occasionally following major trauma a primary amputation is preferable. This would be the case in an open fracture with major distal neurovascular compromise and other more life threatening injuries are present. Vascular surgery The first two categories are the most prevalent. Diabetic foot sepsis is often a major cause of sepsis which can spread rapidly in the presence of established peripheral vascular disease. As a general rule the main issue in vascular surgery is to optimise vascular inflow prior to surgery. The more distal the planned amputation is to be, the more important this rule becomes. In other situations there has been something such as an embolic event that has not been revascularised in time. In this case the limb shows fixed mottling and an amputation will be needed. Types of amputations As the vast majority of commonly performed amputations affect the lower limbs these will be covered here. The main categories of amputations are: Pelvic disarticulation (hindquarter) Above knee amputation Gritti Stokes (through knee amputation) Below knee amputation (using either Skew or Burgess flaps) Syme's amputation (through ankle) Amputations of mid foot and digits Choosing a level of amputation depends on: The disease process being treated Desired functional outcome Co-morbidities of the patient Above knee amputations Quick to perform Heal reliably Patients regain their general health quickly For this benefit, a functional price has to be paid and many patients over the age of 70 will never walk on an above knee prosthesis. Above knee amputations use equal anterior-posterior flaps Below knee amputations Technically more challenging to perform Heal less reliably than their above knee counterparts. However, many more patients are able to walk using a below knee prosthesis. In below knee amputations the two main flaps are Skew flaps or the Burgess long posterior flap. Skew flaps result in a less bulky limb that is easier to attach a prosthesis to. It is worth remembering that whilst it may be technically feasible to offer a below knee amputation there may be circumstances where an above knee option is preferable. For example, in fixed flexion deformities of the lower limb, little functional benefit would be gained from below knee amputation surgery.

Answer 1559

Median arcuate ligament syndrome is largely a diagnosis of exclusion. The classic signs of epigastric pain with an audible bruit are only found in a minority. Where the condition is suspected, the diagnosis is usually apparent on duplex scanning (in thin patients) or with CT angiography. Mesenteric vessel disease Mesenteric ischaemia accounts for 1 in 1000 acute surgical admissions. It is primarily caused by arterial embolism resulting in infarction of the colon. It is more likely to occur in areas such as the splenic flexure that are located at the borders of the territory supplied by the superior and inferior mesenteric arteries. Types Acute mesenteric embolus (commonest 50%) Sudden onset abdominal pain followed by profuse diarrhoea. May be associated with vomiting. Rapid clinical deterioration. Serological tests: WCC, lactate, amylase may all be abnormal particularly in established disease. These can be normal in the early phases. Acute on chronic mesenteric ischaemia Usually longer prodromal history. Post prandial abdominal discomfort and weight loss are dominant features. Patients will usually present with an acute on chronic event, but otherwise will tend not to present until mesenteric flow is reduced by greater than 80%. When acute thrombosis occurs presentation may be as above. In the chronic setting the symptoms will often be those of ischaemic colitis (mucosa is the most sensitive area to this insult). Mesenteric vein thrombosis Usually a history over weeks. Overt abdominal signs and symptoms will not occur until venous thrombosis has reached a stage to compromise arterial inflow. Thrombophilia accounts for 60% of cases. Low flow mesenteric infarction This occurs in patients with multiple co morbidities in whom mesenteric perfusion is significantly compromised by overuse of inotropes or background cardiovascular compromise. The end result is that the bowel is not adequately perfused and infarcts occur from the mucosa outwards. Diagnosis Serological tests: WCC, lactate, CRP, amylase (can be normal in early disease). Cornerstone for diagnosis of arterial AND venous mesenteric disease is CT angiography scanning in the arterial phase with thin slices (<5mm). Venous phase contrast is not helpful. SMA duplex USS is useful in the evaluation of proximal SMA disease in patients with chronic mesenteric ischaemia. MRI is of limited use due to gut peristalsis and movement artefact. Management Overt signs of peritonism: Laparotomy Mesenteric vein thrombosis: If no peritonism: Medical management with IV heparin At operation limited resection of frankly necrotic bowel with view to relook laparotomy at 24-48h. In the interim urgent bowel revascularisation via endovascular (preferred) or surgery. Prognosis Overall poor. Best outlook is from an acute ischaemia from an embolic event where surgery occurs within 12h. Survival may be 50%. This falls to 30% with treatment delay. The other conditions carry worse survival figures.

Answer 1560

This patient has had a transient ischaemic attack. He urgently needs carotid duplex scanning to assess if he needs a carotid endarterectomy. Vascular investigations Venous disease Venous Doppler The simplest investigation for assessment of venous junctional incompetence is a Doppler assessment. This involves the patient standing and manual compression of the limb distal to the junction of interest. Flow should normally occur in one direction only. Where junctional incompetence is present reverse flow will occur and is relatively easy to identify. Venograms and duplex scans Structural venous information is historically obtained using a venogram. This is an invasive test and rarely required in modern clinical practice. The most helpful test is a venous duplex scan which will provide information relating to flow and vessel characteristics. Duplex is also useful in providing vein maps for bypass surgery. Arterial disease Ankle-brachial pressure The ankle brachial pressure index measurement is an important investigation as it will allow classification of the severity of the flow compromise present. False readings may occur in those with calcified vessels such as diabetics and results in such settings should be interpreted with caution. When auscultating the vessel note should be made of the character of the signal. Monophasic signals are associated with a proximal stenosis and reduction in flow. Triphasic signals provide reassurance of a healthy vessel. Arterial Duplex As with the vein the duplex scan can provide a substantial amount of information about arterial patency and flow patterns. In skilled hands they can provide insight as to the state of proximal vessels that are anatomically inaccessible to duplex (e.g. Iliacs). Through assessment of distal flow patterns. It is an operator dependent test. Conventional angiogram Vessel puncture and catheter angiography is the gold standard method of assessing arteries. High quality information can usually be obtained. Limitations of the technique include the risk of contrast toxicity and risks of vessel damage. Severely calcified vessels may be difficult to puncture and in this situation a remote access site (e.g. brachial) may be used. This technique is particularly useful in providing a distal arterial roadmap prior to femoro-distal bypass. CT angiography These tests provide a considerable amount of structural and flow information. They require contrast and thus carry the risks associated with this. They are particularly useful in the setting of GI bleeding as they are rapidly available and can be performed by a non vascular radiologist. However, they lack the facility for endovascular intervention. In general they do not provide high enough resolution for distal arterial surgery. Magnetic resonance angiography This has the advantage of being non-invasive and not using nephrotoxic contrast. Movement artifact remains a problem in some sites and distal arterial resolution is imperfect.

Answer 1561

Right sided live donor transplants are extremely rare. This is because the vena cava precludes mobilisation of the right renal artery. The short right renal artery that is produced therefore presents a major challenge. The sudden cessation of urine output in this context is highly suggestive of an acute thrombosis. Delay in thrombectomy beyond 1 hour almost inevitably results in graft loss. Complications following renal transplant Renal transplantation is widely practised. The commonest technical related complications are related to the ureteric anastomosis. The warm ischaemic time is also of considerable importance and graft survival is directly related to this. Long warm ischaemic times increase the risk of acute tubular necrosis which may occur in all types of renal transplanation and provided other insults are minimised, will usually recover. Organ rejection may occur at any phase following the transplantation process. Immunological complications Types of organ rejection Hyperacute. This occurs immediately through presence of pre formed antibody (such as ABO incompatibility). Acute. Occurs during the first 6 months and is usually T cell mediated. Usually tissue infiltrates and vascular lesions. Chronic. Occurs after the first 6 months. Vascular changes predominate. Hyperacute Renal transplants are most susceptible to this process. Risk factors include major HLA mismatch and ABO incompatibility. The rejection occurs almost immediately and the macroscopic features may become manifest following completion of the vascular anastomosis and removal of clamps. The kidney becomes mottled, dusky and the vessels will thrombose. The only treatment is removal of the graft, if left in situ it will result in abscess formation. Acute All organs may undergo acute rejection. Mononuclear cell infiltrates predominate. All types of transplanted organ are susceptible and it may occur in up to 50% cases. Most cases can be managed medically. Chronic Again all transplants with HLA mismatch may suffer this fate. Previous acute rejections and other immunosensitising events all increase the risk. Vascular changes are most prominent with myointimal proliferation leading to organ ischaemia. Organ specific changes are also seen such as loss of acinar cells in pancreas transplants and rapidly progressive coronary artery disease in cardiac transplants. Technical complications Complication Presenting features Treatment Renal artery thrombosis Sudden complete loss of urine output Immediate surgery may salvage the graft, delays beyond 30 minutes are associated with a high rate of graft loss Renal artery stenosis Uncontrolled hypertension, allograft dysfunction and oedema Angioplasty is the treatment of choice Renal vein thrombosis Pain and swelling over the graft site, haematuria and oliguria The graft is usually lost Urine leaks Diminished urine output, rising creatinine, fever and abdominal pain USS shows perigraft collection, necrosis of ureter tip is the commonest cause and the anastomosis may need revision Lymphocele Common complication (occurs in 15%), may present as a mass, if large may compress ureter May be drained with percutaneous technique and sclerotherapy, or intraperitoneal drainage

Answer 1562

The greater curvature of the stomach is closely related to the gastroepiploic artery. The short gastric vessels are closely related to the fundus. Upper gastrointestinal bleeding Patients may present with the following: Haematemesis and/ or malaena Epigastric discomfort Sudden collapse The extent to which these will occur will depend upon the source. Mortality is higher in patients presenting with haematemesis than malaena alone. Oesophageal bleeding Cause Presenting features Oesophagitis Small volume of fresh blood, often streaking vomit. Malaena rare. Often ceases spontaneously. Usually history of antecedent GORD type symptoms. Cancer Usually small volume of blood, except as pre terminal event with erosion of major vessels. Often associated symptoms of dysphagia and constitutional symptoms such as weight loss. May be recurrent until malignancy managed. Mallory Weiss Tear Typically brisk small to moderate volume of bright red blood following bout of repeated vomiting. Malaena rare. Usually ceases spontaneously. Varices Usually large volume of fresh blood. Swallowed blood may cause malaena. Often associated with haemodynamic compromise. May stop spontaneously but re-bleeds are common until appropriately managed. Gastric Bleeding Cause Presenting features Gastric cancer May be frank haematemesis or altered blood mixed with vomit. Usually prodromal features of dyspepsia and may have constitutional symptoms. Amount of bleeding variable but erosion of major vessel may produce considerable haemorrhage. Dieulafoy Lesion Often no prodromal features prior to haematemesis and malaena, but this arteriovenous malformation may produce quite considerable haemorrhage and may be difficult to detect endoscopically. Diffuse erosive gastritis Usually haematemesis and epigastric discomfort. Usually there is an underlying cause such as recent NSAID usage. Large volume haemorrhage may occur with considerable haemodynamic compromise. Gastric ulcer Small low volume bleeds more common so would tend to present as iron deficiency anaemia. Erosion into a significant vessel may produce considerable haemorrhage and haematemesis. Duodenum Most common cause of major haemorrhage is a posteriorly sited duodenal ulcer. However, ulcers at any site in the duodenum may present with haematemesis, malaena and epigastric discomfort. The pain of duodenal ulcer is slightly different to that of gastric ulcers and often occurs several hours after eating. Peri ampullary tumours may bleed but these are rare. In patients with previous abdominal aortic aneurysm surgery aorto-enteric fistulation remains a rare but important cause of major haemorrhage associated with high mortality. Management Admission to hospital careful monitoring, cross match blood, check FBC, LFTs, U+E and Clotting (as a minimum) Patients with on-going bleeding and haemodynamic instability are likely to require O negative blood pending cross matched blood Early control of airway is vital (e.g. Drowsy patient with liver failure) Patients with suspected varices should receive terlipressin prior to endoscopy Ideally all patients admitted with upper gastrointestinal haemorrhage should undergo Upper GI endoscopy within 24 hours of admission. In those who are unstable this should occur immediately after resuscitation or in tandem with it. The endoscopy department is a potentially dangerous place for unstable patients and it may be safer to perform the endoscopy in theatre with an anaesthetist present. Varices should be banded or subjected to sclerotherapy. If this is not possible owing to active bleeding then a Sengstaken- Blakemore tube (or Minnesota tube) should be inserted. This should be done with care; gastric balloon should be inflated first and oesophageal balloon second. Remember the balloon will need deflating after 12 hours (ideally sooner) to prevent necrosis. Portal pressure should be lowered by combination of medical therapy +/- TIPSS. Patients with erosive oesophagitis / gastritis should receive a proton pump inhibitor. Mallory Weiss tears will typically resolve spontaneously Identifiable bleeding points should receive combination therapy of injection of adrenaline and either a thermal or mechanical treatment. All who have received intervention should receive a continuous infusion of a proton pump inhibitor (IV omeprazole for 72 hours) to reduce the re-bleeding rate. Patients with diffuse erosive gastritis who cannot be managed endoscopically and continue to bleed may require gastrectomy Bleeding ulcers that cannot be controlled endoscopically may require laparotomy and ulcer underruning Indications for surgery Patients > 60 years Continued bleeding despite endoscopic intervention Recurrent bleeding Known cardiovascular disease with poor response to hypotension Surgery Duodenal ulcer Laparotomy, duodenotomy and under running of the ulcer. If bleeding is brisk then the ulcer is almost always posteriorly sited and will have invaded the gastroduodenal artery. Large bites using 0 Vicryl are taken above and below the ulcer base to occlude the vessel. The duodenotomy should be longitudinal but closed transversely to avoid stenosis. For gastric ulcer Under-running of the bleeding site Partial gastrectomy-antral ulcer Partial gastrectomy or under running the ulcer- lesser curve ulcer (involving left gastric artery) Total gastrectomy if bleeding persists Summary of Acute Upper GI bleeding recommendations: The need for admission and timing of endoscopic intervention may be predicted by using the Blatchford score. This considers a patients Hb, serum urea, pulse rate and blood pressure. Those patients with a score of 0 are low risk, all others are considered high risk and require admission and endoscopy. The requirement for pre endoscopic proton pump inhibition is contentious. In the UK the National Institute of Clinical Excellence guidelines suggest the pre endoscopic PPI therapy is unnecessary. Whilst it is accepted that such treatment has no impact on mortality or morbidity a Cochrane review of this practice in 2007 did suggest that it reduced the stigmata of recent haemorrhage at endoscopy. As a result many will still administer PPI to patients prior to endoscopic intervention. Following endoscopy it is important to calculate the Rockall score for patients to determine their risk of rebleeding and mortality. A score of 3 or less is associated with a rebleeding rate of 4% and a very low risk of mortality and identifies a group of patients suitable for early discharge. References 1. http://www.sign.ac.uk/guidelines/fulltext/105/index.html 2. Joint Advisory Group on Endoscopy (JAG) Guidelines - http://www.thejag.org.uk 3. NICE Guideline: Management of acute upper GI bleeding. July 2012.

Answer 1563

Scaphoid fractures in children are rare, will usually involve the distal pole and are easily missed. The initial clinical examination (and sometimes x-rays) may be normal and repeated clinical examination and imaging is advised for this reason. Whilst the other injuries may be sustained from a fall onto an outstretched hand they are less likely to be overlooked on clinical examination. In the case of a Bennetts fracture, the injury mechanism is less compatible with this type of injury. Scaphoid fractures - Incidence of scaphoid fractures in UK ranges from 12.4 per 100,000 to 29 per 100,000 Surface of scaphoid is covered by articular cartilage with small area available for blood vessels (fracture risks blood supply) Forms floor of anatomical snuffbox Risk of fracture associated with fall onto outstretched hand (tubercle, waist, or proximal third) A series of 4 scaphoid radiographs should be undertaken (PA, pronated oblique, Ziter view and lateral view). The Ziter view is a PA view with the wrist in ulnar deviation and beam angulated at 20 degrees Sensitivity of scaphoid radiographs in 1st week of injury is 80% Immobilization of scaphoid fractures difficult Repeat imaging should be done at 10 days. MRI should be done in cases of diagnostic uncertainty Classification of scaphoid fractures Scaphoid tubercle Distal pole Waist Proximal pole Management Undisplaced fractures of the waist of the scaphoid and most distal pole fractures can be managed in a cast for 6 weeks with high rates of union. Displaced scaphoid waist fractures (more than 1-2mm) should be viewed as unstable and surgically fixed. All proximal pole fractures should be fixed surgically. Complications Non union of scaphoid Avascular necrosis of the scaphoid Scapholunate disruption and wrist collapse Degenerative changes of the adjacent joint Reference Berber O et al. Fractures of the scaphoid. BMJ 2020 (369): 414-416.

Answer 1564

The tunica vaginalis is derived from peritoneum, it secretes the fluid that fills the hydrocele cavity. Scrotal and testicular anatomy Spermatic cord Formed by the vas deferens and is covered by the following structures: Layer Origin Internal spermatic fascia Transversalis fascia Cremasteric fascia From the fascial coverings of internal oblique External spermatic fascia External oblique aponeurosis Contents of the cord Vas deferens Transmits sperm and accessory gland secretions Testicular artery Branch of abdominal aorta supplies testis and epididymis Artery of vas deferens Arises from inferior vesical artery Cremasteric artery Arises from inferior epigastric artery Pampiniform plexus Venous plexus, drains into right or left testicular vein Sympathetic nerve fibres Lie on arteries, the parasympathetic fibres lie on the vas Genital branch of the genitofemoral nerve Supplies cremaster Lymphatic vessels Drain to lumbar and para-aortic nodes Scrotum Composed of skin and closely attached dartos fascia. Arterial supply from the anterior and posterior scrotal arteries Lymphatic drainage to the inguinal lymph nodes Parietal layer of the tunica vaginalis is the innermost layer Testes The testes are surrounded by the tunica vaginalis (closed peritoneal sac). The parietal layer of the tunica vaginalis adjacent to the internal spermatic fascia. The testicular arteries arise from the aorta immediately inferiorly to the renal arteries. The pampiniform plexus drains into the testicular veins, the left drains into the left renal vein and the right into the inferior vena cava. Lymphatic drainage is to the para-aortic nodes.

Answer 1565

The IVC passes through the diaphragm at T8. Inferior vena cava Origin L5 Path Left and right common iliac veins merge to form the IVC. Passes right of midline Paired segmental lumbar veins drain into the IVC throughout its length The right gonadal vein empties directly into the cava and the left gonadal vein generally empties into the left renal vein. The next major veins are the renal veins and the hepatic veins Pierces the central tendon of diaphragm at T8 Right atrium Relations Anteriorly Small bowel, first and third part of duodenum, head of pancreas, liver and bile duct, right common iliac artery, right gonadal artery Posteriorly Right renal artery, right psoas, right sympathetic chain, coeliac ganglion Levels Level Vein T8 Hepatic vein, inferior phrenic vein, pierces diaphragm L1 Right suprarenal vein, renal vein L2 Gonadal vein L1-5 Lumbar veins L5 Common iliac vein, formation of IVC

Answer 1566

Peroneus tertius is innervated by the deep peroneal nerve. Tibial nerve Begins at the upper border of the popliteal fossa and is a branch of the sciatic nerve. Root values: L4, L5, S1, S2, S3 Muscles innervated Popliteus Gastrocnemius Soleus Plantaris Tibialis posterior Flexor hallucis longus Flexor digitorum brevis and longus Terminates by dividing into the medial and lateral plantar nerves.

Answer 1567

In this setting a contained haematoma is the most likely cause. This will impair venous return resulting in laryngeal oedema and respiratory compromise. Thyroid disease Patients may present with a number of different manifestations of thyroid disease. They can be broadly sub classified according to whether they are euthyroid or have clinical signs of thyroid dysfunction. In addition it needs to be established whether they have a mass or not. Assessment History Examination including USS If a nodule is identified then it should be sampled ideally via an image guided fine needle aspiration Radionucleotide scanning is of limited use Thyroid Tumours Papillary carcinoma Follicular carcinoma Anaplastic carcinoma Medullary carcinoma Lymphoma's Multinodular goitre One of the most common reasons for presentation Provided the patient is euthyroid and asymptomatic and no discrete nodules are seen, they can be reassured. In those with compressive symptoms surgery is required and the best operation is a total thyroidectomy. Sub total resections were practised in the past and simply result in recurrent disease that requires a difficult revisional resection. Endocrine dysfunction In general these patients are managed by physicians initially. Surgery may be offered alongside radio iodine for patients with Graves disease that fails with medical management or in patients who would prefer not to be irradiated (e.g. pregnant women). Patients with hypothyroidism do not generally get offered a thyroidectomy. Sometimes people inadvertently get offered resections during the early phase of Hashimotos thyroiditis, however, with time the toxic phase passes and patients can simply be managed with thyroxine. Complications following surgery Anatomical such as recurrent laryngeal nerve damage. Bleeding. Owing to the confined space haematoma's may rapidly lead to respiratory compromise owing to laryngeal oedema. Damage to the parathyroid glands resulting in hypocalcaemia. Further sources of information 1. http://www.acb.org.uk/docs/TFTguidelinefinal.pdf- Association of Clinical Biochemistry guidelines for thyroid function tests. 2. British association of endocrine surgeons website- http://www.baets.org.uk

Answer 1568

Pancreatic cancer can cause severe pain as a result of retroperitoneal nerve infiltration. It can be managed with chemical neurectomy/ nerve blocks. Management of pain World Health Organisation Analgesic Ladder Initially peripherally acting drugs such as paracetamol or non-steroidal anti-inflammatory drugs (NSAIDs) are given. If pain control is not achieved, the second part of the ladder is to introduce weak opioid drugs such as codeine or dextropropoxyphene together with appropriate agents to control and minimise side effects. The final rung of the ladder is to introduce strong opioid drugs such as morphine. Analgesia from peripherally acting drugs may be additive to that from centrally-acting opioids and thus, the two are given together. The World Federation of Societies of Anaesthesiologists (WFSA) Analgesic Ladder For management of acute pain Initially, the pain can be expected to be severe and may need controlling with strong analgesics in combination with local anaesthetic blocks and peripherally acting drugs. The second rung on the postoperative pain ladder is the restoration of the use of the oral route to deliver analgesia. Strong opioids may no longer be required and adequate analgesia can be obtained by using combinations of peripherally acting agents and weak opioids. The final step is when the pain can be controlled by peripherally acting agents alone. Local anaesthetics Infiltration of a wound with a long-acting local anaesthetic such as Bupivacaine Analgesia for several hours Further pain relief can be obtained with repeat injections or by infusions via a thin catheter Blockade of plexuses or peripheral nerves will provide selective analgesia in those parts of the body supplied by the plexus or nerves Can either be used to provide anaesthesia for the surgery or specifically for postoperative pain relief Especially useful where a sympathetic block is needed to improve postoperative blood supply or where central blockade such as spinal or epidural blockade is contraindicated. Spinal anaesthesia Provides excellent analgesia for surgery in the lower half of the body and pain relief can last many hours after completion of the operation if long-acting drugs containing vasoconstrictors are used. - Side effects of spinal anaesthesia include: hypotension, sensory and motor block, nausea and urinary retention. Epidural anaesthesia An indwelling epidural catheter inserted. This can then be used to provide a continuous infusion of analgesic agents. It can provide excellent analgesia. They are still the preferred option following major open abdominal procedures and help prevent post operative respiratory compromise resulting from pain. - Disadvantages of epidurals is that they usually confine patients to bed, especially if a motor block is present. In addition an indwelling urinary catheter is required. Which may not only impair mobility but also serve as a conduit for infection. They are contraindicated in coagulopathies. Transversus Abdominal Plane block (TAP) In this technique an ultrasound is used to identify the correct muscle plane and local anaesthetic (usually bupivicaine) is injected. The agent diffuses in the plane and blocks many of the spinal nerves. It is an attractive technique as it provides a wide field of blockade but does not require the placement of any indwelling devices. There is no post operative motor impairment. For this reason it is the preferred technique when extensive laparoscopic abdominal procedures are performed. They will then provide analgesia immediately following surgery but as they do not confine the patient to bed, the focus on enhanced recovery can begin sooner. -The main disadvantage is that their duration of action is limited to the half life of the local anaesthetic agent chosen. In addition some anaesthetists do not have the USS skills required to site the injections. Patient Controlled Analgesia (PCA) - Patients administer their own intravenous analgesia and titrate the dose to their own end-point of pain relief using a small microprocessor - controlled pump. Morphine is the most popular drug used. Strong Opioids Severe pain arising from deep or visceral structures requires the use of strong opioids Morphine Short half life and poor bioavailability. Metabolised in the liver and clearance is reduced in patients with liver disease, in the elderly and the debilitated Side effects include nausea, vomiting, constipation and respiratory depression. Tolerance may occur with repeated dosage Pethidine Synthetic opioid which is structurally different from morphine but which has similar actions. Has 10% potency of morphine. Short half life and similar bioavailability and clearance to morphine. Short duration of action and may need to be given hourly. Pethidine has a toxic metabolite (norpethidine) which is cleared by the kidney, but which accumulates in renal failure or following frequent and prolonged doses and may lead to muscle twitching and convulsions. Extreme caution is advised if pethidine is used over a prolonged period or in patients with renal failure. Weak opioids Codeine: markedly less active than morphine, has predictable effects when given orally and is effective against mild to moderate pain. Non opioid analgesics - Mild to moderate pain. Paracetamol Inhibits prostaglandin synthesis. Analgesic and antipyretic properties but little anti-inflammatory effect It is well absorbed orally and is metabolised almost entirely in the liver Side effects in normal dosage and is widely used for the treatment of minor pain. It causes hepatotoxicity in over dosage by overloading the normal metabolic pathways with the formation of a toxic metabolite. NSAIDs Analgesic and anti-inflammatory actions Inhibition of prostaglandin synthesis by the enzyme Cyclooxygenase which catalyses the conversion of arachidonic acid to the various prostaglandins that are the chief mediators of inflammation. All NSAIDs work in the same way and thus there is no point in giving more than one at a time. . NSAIDs are, in general, more useful for superficial pain arising from the skin, buccal mucosa, joint surfaces and bone. Relative contraindications: history of peptic ulceration, gastrointestinal bleeding or bleeding diathesis; operations associated with high blood loss, asthma, moderate to severe renal impairment, dehydration and any history of hypersensitivity to NSAIDs or aspirin. Neuropathic pain National Institute of Clinical Excellence (UK) guidelines: First line: Amitriptyline (Imipramine if cannot tolerate) or pregabalin Second line: Amitriptyline AND pregabalin Third line: refer to pain specialist. Give tramadol in the interim (avoid morphine) If diabetic neuropathic pain: Duloxetine As of 1 April 2019, pregabalin and gabapentin are Class C controlled substances (under the Misuse of Drugs Act 1971) and scheduled under the Misuse of Drugs Regulations 2001 as Schedule 3. Evaluate patients carefully for a history of drug abuse before prescribing and observe patients for development of signs of abuse and dependence (MHRA, Drug Safety Update April 2019). References 1. http://guidance.nice.org.uk/CG173/Guidance/pdf/English 2. Lovich-Sapola J, Smith CE, Brandt CP. Post operative pain control. Surg Clin North Am. 2015 Apr;95(2):301-183. Finnerup N et al. Pharmacotherapy for neuropathic pain in adults: a systematic review and meta-analysis. Lancet Neurol. 2015 Feb;14(2):162-73.

Answer 1569

This is likely to be a venous leg ulcer. These are typically managed using compression bandages. Contra indications to this technique include peripheral vascular disease (not present here). Methods of wound closure Method of closure Indication Primary closure Clean wound, usually surgically created or following minor trauma Standard suturing methods will usually suffice Wound heals by primary intention Delayed primary closure Similar methods of actual closure to primary closure May be used in situations where primary closure is either not achievable or not advisable e.g. infection Vacuum assisted closure Uses negative pressure therapy to facilitate wound closure Sponge is inserted into wound cavity and then negative pressure applied Advantages include removal of exudate and versatility Disadvantages include cost and risk of fistulation if used incorrectly on sites such as bowel Split thickness skin grafts Superficial dermis removed with Watson knife or dermatome (commonly from thigh) Remaining epithelium regenerates from dermal appendages Coverage may be increased by meshing Full thickness skin grafts Whole dermal thickness is removed Sub dermal fat is then removed and graft placed over donor site Better cosmesis and flexibility at recipient site Donor site morbidity Flaps Viable tissue with a blood supply May be pedicled or free Pedicled flaps are more reliable, but limited in range Free flaps have greater range but carry greater risk of breakdown as they require vascular anastomosis

Answer 1570

Cryoprecipitate - Blood product made from plasma Usually transfused as 6 unit pool Indications include massive haemorrhage and uncontrolled bleeding due to haemophilia Composition Agent Quantity Factor VIII 100IU Fibrinogen 250mg von Willebrand factor Variable Factor XIII Variable

Answer 1571

Nimodipine is a calcium channel blocker. It reduces cerebral vasospasm and improves outcomes. It is administered to most cases of sub arachnoid haemorrhage. Sub arachnoid haemorrhage Spontaneous intracranial haemorrhage Most commonly sub arachnoid haemorrhage. It is due to intra cranial aneurysm in 85% cases. Approximately 10% of cases will have normal angiography and the cause will remain unclear. Patients with inherited connective tissue disorders are at higher risk although most cases are sporadic. >95% cases will have headache (often thunderclap) >15% will have coma Investigation CT scan for all (although as CSF blood clears the sensitivity declines) Lumbar puncture if CT normal (very unlikely if normal) CT angiogram to look for aneurysms. Management Supportive treatment, optimising BP (not too high if untreated aneurysm) and ventilation if needed. Nimodipine reduces cerebral vasospasm and reduces poor outcomes. Untreated patients most likely to rebleed in first 2 weeks. Patients developing hydrocephalus will need a V-P shunt (external ventricular drain acutely). Electrolytes require careful monitoring and hyponatraemia is common. Treatment of aneurysm >80% aneuryms arise from the anterior circulation Craniotomy and clipping of aneurysm is the traditional treatment, alternatively suitable lesions may be coiled using an endovascular approach. Where both options are suitable data suggests that outcomes are better with coiling than surgery.

Answer 1572

The normal angle in males between the femoral head and shaft is 130o. Changes to this angle may occur as a result of disease or pathology and should be investigated. Females have an angle that is around 110-120o Hip joint Head of femur articulates with acetabulum of the pelvis Both covered by articular hyaline cartilage The acetabulum forms at the union of the ilium, pubis, and ischium The triradiate cartilage (Y-shaped growth plate) separates the pelvic bones The acetabulum holds the femoral head by the acetabular labrum Normal angle between femoral head and femoral shaft is 130o Ligaments Transverse ligament: joints anterior and posterior ends of the articular cartilage Head of femur ligament (ligamentum teres): acetabular notch to the fovea. Contains arterial supply to head of femur in children. Extracapsular ligaments Iliofemoral ligament: inverted Y shape. Anterior iliac spine to the trochanteric line Pubofemoral ligament: acetabulum to lesser trochanter Ischiofemoral ligament: posterior support. Ischium to greater trochanter. Blood supply Medial circumflex femoral and lateral circumflex femoral arteries (Branches of profunda femoris). Also from the inferior gluteal artery. These form an anastomosis and travel to up the femoral neck to supply the head.

Answer 1573

The transverse cervical nerve lies within the posterior triangle (the transverse cervical nerve divides into superior and inferior branches of the anterior margin of SCM). The anterior jugular vein is formed in the submental region and descends in the superficial fascia near the median plane. It passes inferior to enter the suprasternal space, it is linked to the contralateral anterior jugular vein by the jugular venous arch. Anterior triangle of the neck Boundaries Anterior border of the Sternocleidomastoid Lower border of mandible Anterior midline Sub triangles (divided by Digastric above and Omohyoid) Muscular triangle: Neck strap muscles Carotid triangle: Carotid sheath Submandibular Triangle (digastric) Contents of the anterior triangle Digastric triangle Submandibular gland Submandibular nodes Facial vessels Hypoglossal nerve Muscular triangle Strap muscles Jugular vein Carotid triangle Carotid sheath (Common carotid, vagus and internal jugular vein) Ansa cervicalis Nerve supply to digastric muscle Anterior: Mylohyoid nerve Posterior: Facial nerve

Answer 1574

This man has a high output and anatomically high fistula. Drying up the fistula with octreotide will not suffice, his nutrition is compromised and TPN will help. Fistulas A fistula is defined as an abnormal connection between two epithelial surfaces. There are many types ranging from Branchial fistulae in the neck to entero-cutaneous fistulae abdominally. In general surgical practice the abdominal cavity generates the majority and most of these arise from diverticular disease and Crohn's. As a general rule all fistulae will resolve spontaneously as long as there is no distal obstruction. This is particularly true of intestinal fistulae. The four types of fistulae are: Enterocutaneous These link the intestine to the skin. They may be high (>500ml) or low output (<250ml) depending upon source. Duodenal /jejunal fistulae will tend to produce high volume, electrolyte rich secretions which can lead to severe excoriation of the skin. Colo-cutaneous fistulae will tend to leak faeculent material. Both fistulae may result from the spontaneous rupture of an abscess cavity onto the skin (such as following perianal abscess drainage) or may occur as a result of iatrogenic input. In some cases it may even be surgically desirable e.g. mucous fistula following sub total colectomy for colitis. Suspect if there is excess fluid in the drain. Enteroenteric or Enterocolic This is a fistula that involves the large or small intestine. They may originate in a similar manner to enterocutaneous fistulae. A particular problem with this fistula type is that bacterial overgrowth may precipitate malabsorption syndromes. This may be particularly serious in inflammatory bowel disease. Enterovaginal Aetiology as above. Enterovesical This type of fistula goes to the bladder. These fistulas may result in frequent urinary tract infections, or the passage of gas from the urethra during urination. Management Some rules relating to fistula management: They will heal provided there is no underlying inflammatory bowel disease and no distal obstruction, so conservative measures may be the best option Where there is skin involvement, protect the overlying skin, often using a well fitted stoma bag- skin damage is difficult to treat A high output fistula may be rendered more easily managed by the use of octreotide, this will tend to reduce the volume of pancreatic secretions. Nutritional complications are common especially with high fistula (e.g. high jejunal or duodenal) these may necessitate the use of TPN to provide nutritional support together with the concomitant use of octreotide to reduce volume and protect skin. When managing perianal fistulae surgeons should avoid probing the fistula where acute inflammation is present, this almost always worsens outcomes. When perianal fistulae occur secondary to Crohn's disease the best management option is often to drain acute sepsis and maintain that drainage through the judicious use of setons whilst medical management is implemented. Always attempt to delineate the fistula anatomy, for abscesses and fistulae that have an intra abdominal source the use of barium and CT studies should show a track. For perianal fistulae surgeons should recall Goodsall's rule in relation to internal and external openings.

Answer 1575

Cholecystokinin will often increase the volume of pancreatic secretions. Pancreas exocrine physiology Composition of pancreatic secretions Pancreatic secretions are usually 1000-1500ml per 24 hours and have a pH of 8. Secretion Source Substances secreted Enzymic Acinar cells Trypsinogen Procarboxylase Amylase Elastase Aqueous Ductal and Centroacinar cells Sodium Bicarbonate Water Potassium Chloride NB: Sodium and potassium reflect their plasma levels; chloride and bicarbonate vary with flow rate Regulation The cephalic and gastric phases (neuronal and physical) are less important in regulating the pancreatic secretions. The effect of digested material in the small bowel stimulates CCK release and ACh which stimulate acinar and ductal cells. Of these CCK is the most potent stimulus. In the case of the ductal cells these are potently stimulated by secretin which is released by the S cells of the duodenum. This results in an increase in bicarbonate. Enzyme activation Trypsinogen is converted via enterokinase to active trypsin in the duodenum. Trypsin then activates the other inactive enzymes

Answer 1576

Acute embolic events account for up to 50% of cases of mesenteric infarcts. These may occur as a result of long standing atrial fibrillation, ventricular anuerysms and post myocardial infarction. Mesenteric vessel disease Mesenteric ischaemia accounts for 1 in 1000 acute surgical admissions. It is primarily caused by arterial embolism resulting in infarction of the colon. It is more likely to occur in areas such as the splenic flexure that are located at the borders of the territory supplied by the superior and inferior mesenteric arteries. Types Acute mesenteric embolus (commonest 50%) Sudden onset abdominal pain followed by profuse diarrhoea. May be associated with vomiting. Rapid clinical deterioration. Serological tests: WCC, lactate, amylase may all be abnormal particularly in established disease. These can be normal in the early phases. Acute on chronic mesenteric ischaemia Usually longer prodromal history. Post prandial abdominal discomfort and weight loss are dominant features. Patients will usually present with an acute on chronic event, but otherwise will tend not to present until mesenteric flow is reduced by greater than 80%. When acute thrombosis occurs presentation may be as above. In the chronic setting the symptoms will often be those of ischaemic colitis (mucosa is the most sensitive area to this insult). Mesenteric vein thrombosis Usually a history over weeks. Overt abdominal signs and symptoms will not occur until venous thrombosis has reached a stage to compromise arterial inflow. Thrombophilia accounts for 60% of cases. Low flow mesenteric infarction This occurs in patients with multiple co morbidities in whom mesenteric perfusion is significantly compromised by overuse of inotropes or background cardiovascular compromise. The end result is that the bowel is not adequately perfused and infarcts occur from the mucosa outwards. Diagnosis Serological tests: WCC, lactate, CRP, amylase (can be normal in early disease). Cornerstone for diagnosis of arterial AND venous mesenteric disease is CT angiography scanning in the arterial phase with thin slices (<5mm). Venous phase contrast is not helpful. SMA duplex USS is useful in the evaluation of proximal SMA disease in patients with chronic mesenteric ischaemia. MRI is of limited use due to gut peristalsis and movement artefact. Management Overt signs of peritonism: Laparotomy Mesenteric vein thrombosis: If no peritonism: Medical management with IV heparin At operation limited resection of frankly necrotic bowel with view to relook laparotomy at 24-48h. In the interim urgent bowel revascularisation via endovascular (preferred) or surgery. Prognosis Overall poor. Best outlook is from an acute ischaemia from an embolic event where surgery occurs within 12h. Survival may be 50%. This falls to 30% with treatment delay. The other conditions carry worse survival figures.

Answer 1577

The defect is located ventrally and most often distally. Proximally located urethral openings are well recognised. Circumcision may compromise reconstruction. Hypospadias The urethral meatus opens on the ventral surface of the penis. There is also a ventral deficiency of the foreskin. The urethral meatus may open more proximally in the more severe variants. However, 75% of the openings are distally located. The incidence is 1 in 300 male births. Features include: Absent frenular artery Ventrally opened glans Skin tethering to hypoplastic urethra Splayed columns of spongiosum tissue distal to the meatus Deficiency of the foreskin ventrally Management: No routine cultural circumcisions Urethroplasty Penile reconstruction The foreskin is often utilised in the reconstructive process. In boys with very distal disease no treatment may be needed.

Answer 1578

The first web space is innervated by the deep peroneal nerve. Deep peroneal nerve Origin From the common peroneal nerve, at the lateral aspect of the fibula, deep to peroneus longus Nerve root values L4, L5, S1, S2 Course and relation Pierces the anterior intermuscular septum to enter the anterior compartment of the lower leg Passes anteriorly down to the ankle joint, midway between the two malleoli Terminates In the dorsum of the foot Muscles innervated Tibialis anterior Extensor hallucis longus Extensor digitorum longus Peroneus tertius Extensor digitorum brevis Cutaneous innervation Web space of the first and second toes Actions Dorsiflexion of ankle joint Extension of all toes (extensor hallucis longus and extensor digitorum longus) Eversion of the foot After its bifurcation past the ankle joint, the lateral branch of the deep peroneal nerve innervates the extensor digitorum brevis and the extensor hallucis brevis The medial branch supplies the web space between the first and second digits.

Answer 1579

Infection with human papilloma virus 16 is a risk factor for the development of intra epithelial dysplasia of the anal skin with subsequent increased risk of invasive malignancy. Oncoviruses Viruses which cause cancer These may be detected on blood test and prevented by vaccine These are the main types of oncoviruses and their diseases: Oncovirus Cancer Epstein-Barr virus Burkitt's lymphoma Hodgkin's lymphoma Post transplant lymphoma Nasopharyngeal carcinoma Human papillomavirus 16/18 Cervical cancer Anal cancer Penile cancer Vulval cancer Oropharyneal cancer Human herpes virus 8 Kaposi's sarcoma Hepatitis B virus Hepatocellular carcinoma Hepatitis C virus Hepatocellular carcinoma Human T-lymphotropic virus 1 Tropical spastic paraparesis Adult T cell leukaemia

Answer 1580

This is most likely pyelonephritis and partially treated cystitis is a common cause. Haematuria Causes of haematuria Trauma Injury to renal tract Renal trauma commonly due to blunt injury (others penetrating injuries) Ureter trauma rare: iatrogenic Bladder trauma: due to RTA or pelvic fractures Infection Remember TB Malignancy Renal cell carcinoma (remember paraneoplastic syndromes): painful or painless Urothelial malignancies: 90% are transitional cell carcinoma, can occur anywhere along the urinary tract. Painless haematuria. Squamous cell carcinoma and adenocarcinoma: rare bladder tumours Prostate cancer Penile cancers: SCC Renal disease Glomerulonephritis Stones Microscopic haematuria common Structural abnormalities Benign prostatic hyperplasia (BPH) causes haematuria due to hypervascularity of the prostate gland Cystic renal lesions e.g. polycystic kidney disease Vascular malformations Renal vein thrombosis due to renal cell carcinoma Coagulopathy Causes bleeding of underlying lesions Drugs Cause tubular necrosis or interstitial nephritis: aminoglycosides, chemotherapy Interstitial nephritis: penicillin, sulphonamides, and NSAIDs Anticoagulants Benign Exercise Gynaecological Endometriosis: flank pain, dysuria, and haematuria that is cyclical Iatrogenic Catheterisation Radiotherapy; cystitis, severe haemorrhage, bladder necrosis Pseudohaematuria For example following consumption of beetroot References Http://bestpractice.bmj.com/best-practice/monograph/316/overview/aetiology.html

Answer 1581

Mesenteric venous thrombosis is the likely underlying cause and an angiogram is the sensible step as it will also facilitate the identification of areas of infarcted bowel , similar to that which may occur in the leg when massive DVT is present. Acute abdominal pain-diagnoses Conditions presenting with acute abdominal pain Condition Features Investigations Management Appendicitis History of migratory pain. Fever. Anorexia. Evidence of right iliac fossa tenderness. Mild pyrexia. Differential white cell count Pregnancy test C-Reactive protein Amylase Urine dipstick testing Appendicectomy Mesenteric adenitis Usually recent upper respiratory tract infection. High fever. Generalised abdominal discomfort- true localised pain and signs are rare. Full blood count- may show slightly raised white cell count Urine dipstick often normal Abdominal ultrasound scan - usually no free fluid Conservative management- appendicectomy if diagnostic doubt Mittelschmerz Only seen in females Mid cycle pain Usually occurs two weeks after last menstrual period Pain usually has a supra-pubic location Usually subsides over a 24-48 hour period. Full blood count- normal Urine dipstick- normal Abdominal and pelvic ultrasound- may show a trace of pelvic free fluid Manage conservatively if doubt or symptoms fail to settle then laparoscopy Fitz-Hugh Curtis syndrome Disseminated infection with Chlamydia. Usually seen in females. Consists of evidence of pelvic inflammatory disease together with peri-hepatic inflammation and subsequent adhesion formation. Abdominal ultrasound scan- may show free fluid High vaginal swabs - may show evidence of sexually transmitted infections Usually medically managed- doxycycline or azithromycin Abdominal aortic aneurysm (ruptured) Sudden onset of abdominal pain radiating to the back in older adults (look for risk factors). Collapse. May be moribund on arrival in casualty, more stable if contained haematoma. Careful clinical assessment may reveal pulsatile mass. Patients who are haemodynamically stable should have a CT scan Unstable patients should undergo immediate surgery (unless it is not in their best interests). Those with evidence of contained leak on CT should undergo immediate surgery Increasing unruptured aneurysmal size is an indication for urgent surgical intervention (that can wait until the next working day) Perforated peptic ulcer Sudden onset of pain (usually epigastric). Often preceding history of upper abdominal pain. Soon develop generalised abdominal pain. On examination may have clinical evidence of peritonitis. Erect CXR may show free air. A CT scan may be indicated where there is diagnostic doubt Laparotomy (laparoscopic surgery for perforated peptic ulcers is both safe and feasible in experienced hands) Intestinal obstruction Colicky abdominal pain and vomiting (the nature of which depends on the level of the obstruction). Abdominal distension and constipation (again depending upon site of obstruction). Features of peritonism may occur where local necrosis of bowel loops is occurring. A plain abdominal film may help with making the diagnosis. A CT scan may be useful where diagnostic uncertainty exists In those with a virgin abdomen a lower and earlier threshold for laparotomy should exist than in those who may have adhesional obstruction Mesenteric infarction Embolic events present with sudden pain and forceful evacuation. Acute on chronic events usually have a longer history and previous weight loss. On examination the pain is typically greater than the physical signs would suggest. Arterial pH and lactate Arterial phase CT scanning is the most sensitive test Immediate laparotomy and resection of affected segments, in acute embolic events SMA embolectomy may be needed.

Answer 1582

B- Hyperthyroidism Elevated T4 and suppressed TSH makes this the most likely diagnosis. The PTH level is normal. Hyperthyroidism Causes of hyperthyroidism include: Diffuse toxic goitre (Graves Disease) Toxic nodular goitre Toxic nodule Rare causes Graves disease Graves disease is characterised by a diffuse vascular goitre that appears at the same time as the clinical manifestations of hyperthyroidism. It is commonest in younger females and may be associated with eye signs. Thyrotoxic symptoms will predominate. Up to 50% of patients will have a familial history of autoimmune disorders. The glandular hypertrophy and hyperplasia occur as a result of the thyroid stimulating effects of the TSH receptor antibodies. Toxic nodular goitre In this disorder the goitre is present for a long period of time prior to the development of clinical symptoms. In most goitres the nodules are inactive and in some cases it is the internodular tissue that is responsible for the hyperthyroidism. Toxic nodule Overactive, autonomously functioning nodule. It may occur as part of generalised nodularity or be a true toxic adenoma. The TSH levels are usually low as the autonomously functioning thyroid tissue will exert a negative feedback effect. Signs and symptoms Symptoms Signs Lethargy Tachycardia Emotionally labile Agitation Heat intolerance Hot, moist palms Weight loss Exopthalmos Excessive appetite Thyroid goitre and bruit Palpitations Lid lag/retraction Diagnosis The most sensitive test for diagnosing hyperthyroidism is plasma T3 (which is raised). Note in hypothyroidism the plasma T4 and TSH are the most sensitive tests. A TSH level of <0.5U/L suggests hyperthyroidism. TSH receptor antibodies may be tested for in the diagnosis of Graves. Treatment First line treatment for Graves disease is usually medical and the block and replace regime is the favored option. Carbimazole is administered at higher doses and thyroxine is administered orally. Patients are maintained on this regime for between 6 and 12 months. Attempts are then made to wean off medication. Where relapse then occurs the options are between ongoing medical therapy, radioiodine or surgery.

Answer 1583

IV Pamidronate is the drug of choice as it most effective and has long lasting effects. Calcitonin would need to be given with another agent, to ensure that the hypercalcaemia is treated once its short term effects wear off. IV zoledronate is preferred in scenarios associated with malignancy. Management of hypercalcaemia Free Ca is affected by pH (increased in acidosis) and plasma albumin concentration ECG changes include: Shortening of QTc interval Urgent management is indicated if: Calcium > 3.5 mmol/l Reduced consciousness Severe abdominal pain Pre renal failure Management: Airway Breathing Circulation Intravenous fluid resuscitation with 3-6L of 0.9% Normal saline in 24 hours Concurrent administration of calcitonin will also help lower calcium levels Medical therapy (usually if Corrected calcium >3.0mmol/l) Bisphosphonates Analogues of pryrophosphate Prevent osteoclast attachment to bone matrix and interfere with osteoclast activity Inhibit bone resorption. Agents Drug Side effects Notes IV Pamidronate pyrexia, leucopaenia Most potent agent IV Zoledronate response lasts 30 days Used for malignancy associated hypercalcaemia Calcitonin Quickest onset of action however short duration (tachyphylaxis) therefore only given with a second agent. Prednisolone May be given in hypercalcaemia related to sarcoidosis, myeloma or vitamin D intoxication.

Answer 1584

Posterior urethral valves are one of the commonest causes of poor urinary stream and hesitancy in children. Prostatic disorders are rare. Hypospadias is associated with urine that is difficult to control, but should not produce hesitancy. Urethral valves Posterior urethral valves are the commonest cause of infravesical outflow obstruction in males. They may be diagnosed on ante natal ultrasonography. Because the bladder has to develop high emptying pressures in utero, the child may develop renal parenchymal damage. This translates to renal impairment noted in 70% of boys at presentation. Treatment is with bladder catheterisation. Endoscopic valvotomy is the definitive treatment of choice with cystoscopic and renal follow up.

Answer 1585

TSH receptor antibodies will cause stimulation of the thyroid to synthesise T4. However, this will have a negative feedback effect on the pituitary causing decrease in TSH levels. Where hyperthyroidism occurs secondary to pregnancy the TSH is typically elevated. Thyroid disease Patients may present with a number of different manifestations of thyroid disease. They can be broadly sub classified according to whether they are euthyroid or have clinical signs of thyroid dysfunction. In addition it needs to be established whether they have a mass or not. Assessment History Examination including USS If a nodule is identified then it should be sampled ideally via an image guided fine needle aspiration Radionucleotide scanning is of limited use Thyroid Tumours Papillary carcinoma Follicular carcinoma Anaplastic carcinoma Medullary carcinoma Lymphoma's Multinodular goitre One of the most common reasons for presentation Provided the patient is euthyroid and asymptomatic and no discrete nodules are seen, they can be reassured. In those with compressive symptoms surgery is required and the best operation is a total thyroidectomy. Sub total resections were practised in the past and simply result in recurrent disease that requires a difficult revisional resection. Endocrine dysfunction In general these patients are managed by physicians initially. Surgery may be offered alongside radio iodine for patients with Graves disease that fails with medical management or in patients who would prefer not to be irradiated (e.g. pregnant women). Patients with hypothyroidism do not generally get offered a thyroidectomy. Sometimes people inadvertently get offered resections during the early phase of Hashimotos thyroiditis, however, with time the toxic phase passes and patients can simply be managed with thyroxine. Complications following surgery Anatomical such as recurrent laryngeal nerve damage. Bleeding. Owing to the confined space haematoma's may rapidly lead to respiratory compromise owing to laryngeal oedema. Damage to the parathyroid glands resulting in hypocalcaemia. Further sources of information 1. http://www.acb.org.uk/docs/TFTguidelinefinal.pdf- Association of Clinical Biochemistry guidelines for thyroid function tests. 2. British association of endocrine surgeons website- http://www.baets.org.uk

Answer 1586

The borders of the ulcer are often well defined even though they may be irregular. Heaped or raised borders should raise suspicion of a marjolins ulcer. Lower leg ulcers Venous leg ulcers Most due to venous hypertension, secondary to chronic venous insufficiency (other causes include calf pump dysfunction or neuromuscular disorders) Ulcers form due to capillary fibrin cuff or leucocyte sequestration Features of venous insufficiency include oedema, brown pigmentation, lipodermatosclerosis, eczema Location above the ankle, painless Deep venous insufficiency is related to previous DVT and superficial venous insufficiency is associated with varicose veins Doppler ultrasound looks for presence of reflux and duplex ultrasound looks at the anatomy/ flow of the vein Management: 4 layer compression banding after exclusion of arterial disease or surgery If fail to heal after 12 weeks or >10cm2 skin grafting may be needed Marjolin's ulcer Squamous cell carcinoma Occurring at sites of chronic inflammation e.g; burns, osteomyelitis after 10-20 years Mainly occur on the lower limb Arterial ulcers Occur on the toes and heel Painful There may be areas of gangrene Cold with no palpable pulses Low ABPI measurements Neuropathic ulcers Commonly over plantar surface of metatarsal head and plantar surface of hallux The plantar neuropathic ulcer is the condition that most commonly leads to amputation in diabetic patients Due to pressure Management includes cushioned shoes to reduce callus formation Pyoderma gangrenosum Associated with inflammatory bowel disease/RA Can occur at stoma sites Erythematous nodules or pustules which ulcerate

Answer 1587

Benzodiazepine overdose with marked suppression of respiratory activity should be managed with IV flumazenil. Midazolam Midazolam is a short acting benzodiazepine. It is usually administered intravenously, when administered orally, dosing is less reliable. It is eliminated via the cytochrome P450 pathway in the liver. It is often used for procedural related sedation purposes. It is generally administered in doses of 2-5mg for this purpose. It is often given in combination with a short acting opiate such as fentanyl for analgesic purposes. One of the main reasons that midazolam is preferred for procedural related sedation is due to a degree of amnesia that can accompany it. If administered in excess, most patients can be managed with simple airway support measures an monitoring. However, if there is significant respiratory compromise, it can be reversed with the agent flumazenil which is a selective GABA receptor antagonist.

Answer 1588

The changes seen are the result of raised ICP, its rare for head injuries to cause sufficient blood loss to affect the circulating volume. Cushing reflex When intra cranial pressure exceeds mean arterial pressure, compression of cerebral arterioles occurs. This results in cerebral ischaemia. Increases in ICP results in stepwise activation of the sympathetic nervous system initially. This raises peripheral vascular resistance and results in hypertension. Cardiac output is also increased. These haemodynamic changes are detected by aortic arch baroreceptors and this results in activation of the parasympathetic nervous system. These parasympathetic effects comprise the second stage of the Cushing reflex. The Cushing reflex is a serious development that indicates imminent coning or other terminal events if not resolved quickly.

Answer 1589

This lady is likely to be breast feeding and is at risk of mastitis. This may lead to an abscess if not treated. Staphylococcus aureus is usually the causative organism. Non malignant breast disease Duct ectasia Mammary duct ectasia may be seen in up to 25% of normal female breasts Patients usually present with nipple discharge, which may be from single or multiple ducts (usually present age >50 years) The discharge is often thick and green Duct ectasia is a normal variant of breast involution and is not the same condition as periductal mastitis Mass develops behind nipple Periductal mastitis Present at younger age than duct ectasia May present with features of inflammation, abscess or mammary duct fistula Strongly associated with smoking Usually treated with antibiotics, abscess will require drainage Mass develops around nipple Intraductal papilloma Growth of papilloma in a single duct Usually presents with clear or blood stained discharge originating from a single duct No increase in risk of malignancy Breast abscess Lactational mastitis is common Infection is usually with Staphylococcus aureus On examination there is usually a tender fluctuant mass Treatment is with antibiotics and ultrasound guided aspiration Overlying skin necrosis is an indication for surgical debridement, which may be complicated by the development of a subsequent mammary duct fistula. Tuberculosis Rare in western countries, usually secondary TB Affects women later in child bearing period Chronic breast or axillary sinus is present in up to 50% cases Diagnosis is by biopsy culture and histology

Answer 1590

Paracetamol is an effective analgesic in children and pain following herniotomy is relatively minor. Note that codeine is contra indicated in neonates. The child is too young to receive ibuprofen. Management of pain World Health Organisation Analgesic Ladder Initially peripherally acting drugs such as paracetamol or non-steroidal anti-inflammatory drugs (NSAIDs) are given. If pain control is not achieved, the second part of the ladder is to introduce weak opioid drugs such as codeine or dextropropoxyphene together with appropriate agents to control and minimise side effects. The final rung of the ladder is to introduce strong opioid drugs such as morphine. Analgesia from peripherally acting drugs may be additive to that from centrally-acting opioids and thus, the two are given together. The World Federation of Societies of Anaesthesiologists (WFSA) Analgesic Ladder For management of acute pain Initially, the pain can be expected to be severe and may need controlling with strong analgesics in combination with local anaesthetic blocks and peripherally acting drugs. The second rung on the postoperative pain ladder is the restoration of the use of the oral route to deliver analgesia. Strong opioids may no longer be required and adequate analgesia can be obtained by using combinations of peripherally acting agents and weak opioids. The final step is when the pain can be controlled by peripherally acting agents alone. Local anaesthetics Infiltration of a wound with a long-acting local anaesthetic such as Bupivacaine Analgesia for several hours Further pain relief can be obtained with repeat injections or by infusions via a thin catheter Blockade of plexuses or peripheral nerves will provide selective analgesia in those parts of the body supplied by the plexus or nerves Can either be used to provide anaesthesia for the surgery or specifically for postoperative pain relief Especially useful where a sympathetic block is needed to improve postoperative blood supply or where central blockade such as spinal or epidural blockade is contraindicated. Spinal anaesthesia Provides excellent analgesia for surgery in the lower half of the body and pain relief can last many hours after completion of the operation if long-acting drugs containing vasoconstrictors are used. - Side effects of spinal anaesthesia include: hypotension, sensory and motor block, nausea and urinary retention. Epidural anaesthesia An indwelling epidural catheter inserted. This can then be used to provide a continuous infusion of analgesic agents. It can provide excellent analgesia. They are still the preferred option following major open abdominal procedures and help prevent post operative respiratory compromise resulting from pain. - Disadvantages of epidurals is that they usually confine patients to bed, especially if a motor block is present. In addition an indwelling urinary catheter is required. Which may not only impair mobility but also serve as a conduit for infection. They are contraindicated in coagulopathies. Transversus Abdominal Plane block (TAP) In this technique an ultrasound is used to identify the correct muscle plane and local anaesthetic (usually bupivicaine) is injected. The agent diffuses in the plane and blocks many of the spinal nerves. It is an attractive technique as it provides a wide field of blockade but does not require the placement of any indwelling devices. There is no post operative motor impairment. For this reason it is the preferred technique when extensive laparoscopic abdominal procedures are performed. They will then provide analgesia immediately following surgery but as they do not confine the patient to bed, the focus on enhanced recovery can begin sooner. -The main disadvantage is that their duration of action is limited to the half life of the local anaesthetic agent chosen. In addition some anaesthetists do not have the USS skills required to site the injections. Patient Controlled Analgesia (PCA) - Patients administer their own intravenous analgesia and titrate the dose to their own end-point of pain relief using a small microprocessor - controlled pump. Morphine is the most popular drug used. Strong Opioids Severe pain arising from deep or visceral structures requires the use of strong opioids Morphine Short half life and poor bioavailability. Metabolised in the liver and clearance is reduced in patients with liver disease, in the elderly and the debilitated Side effects include nausea, vomiting, constipation and respiratory depression. Tolerance may occur with repeated dosage Pethidine Synthetic opioid which is structurally different from morphine but which has similar actions. Has 10% potency of morphine. Short half life and similar bioavailability and clearance to morphine. Short duration of action and may need to be given hourly. Pethidine has a toxic metabolite (norpethidine) which is cleared by the kidney, but which accumulates in renal failure or following frequent and prolonged doses and may lead to muscle twitching and convulsions. Extreme caution is advised if pethidine is used over a prolonged period or in patients with renal failure. Weak opioids Codeine: markedly less active than morphine, has predictable effects when given orally and is effective against mild to moderate pain. Non opioid analgesics - Mild to moderate pain. Paracetamol Inhibits prostaglandin synthesis. Analgesic and antipyretic properties but little anti-inflammatory effect It is well absorbed orally and is metabolised almost entirely in the liver Side effects in normal dosage and is widely used for the treatment of minor pain. It causes hepatotoxicity in over dosage by overloading the normal metabolic pathways with the formation of a toxic metabolite. NSAIDs Analgesic and anti-inflammatory actions Inhibition of prostaglandin synthesis by the enzyme Cyclooxygenase which catalyses the conversion of arachidonic acid to the various prostaglandins that are the chief mediators of inflammation. All NSAIDs work in the same way and thus there is no point in giving more than one at a time. . NSAIDs are, in general, more useful for superficial pain arising from the skin, buccal mucosa, joint surfaces and bone. Relative contraindications: history of peptic ulceration, gastrointestinal bleeding or bleeding diathesis; operations associated with high blood loss, asthma, moderate to severe renal impairment, dehydration and any history of hypersensitivity to NSAIDs or aspirin. Neuropathic pain National Institute of Clinical Excellence (UK) guidelines: First line: Amitriptyline (Imipramine if cannot tolerate) or pregabalin Second line: Amitriptyline AND pregabalin Third line: refer to pain specialist. Give tramadol in the interim (avoid morphine) If diabetic neuropathic pain: Duloxetine As of 1 April 2019, pregabalin and gabapentin are Class C controlled substances (under the Misuse of Drugs Act 1971) and scheduled under the Misuse of Drugs Regulations 2001 as Schedule 3. Evaluate patients carefully for a history of drug abuse before prescribing and observe patients for development of signs of abuse and dependence (MHRA, Drug Safety Update April 2019). References 1. http://guidance.nice.org.uk/CG173/Guidance/pdf/English 2. Lovich-Sapola J, Smith CE, Brandt CP. Post operative pain control. Surg Clin North Am. 2015 Apr;95(2):301-183. Finnerup N et al. Pharmacotherapy for neuropathic pain in adults: a systematic review and meta-analysis. Lancet Neurol. 2015 Feb;14(2):162-73.

Answer 1591

The diffuse lung injury, which is associated with loss of surfactant and increased elastase release from neutrophils, results in fluid accumulation. This leads to reduced diffusion, which is the main reason for hypoxaemia. Adult respiratory distress syndrome Defined as an acute condition characterized by bilateral pulmonary infiltrates and severe hypoxemia (PaO2/FiO2 ratio < 200) in the absence of evidence for cardiogenic pulmonary oedema (clinically or pulmonary capillary wedge pressure of less than 18 mm Hg). It is subdivided into two stages. Early stages consist of an exudative phase of injury with associated oedema. The later stage is one of repair and consists of fibroproliferative changes. Subsequent scarring may result in poor lung function. Causes Sepsis Direct lung injury Trauma Acute pancreatitis Long bone fracture or multiple fractures (through fat embolism) Head injury (causes sympathetic nervous stimulation which leads to acute pulmonary hypertension) Clinical features Acute dyspnoea and hypoxaemia hours/days after event Multi organ failure Rising ventilatory pressures Management Treat the underlying cause Antibiotics (if signs of sepsis) Negative fluid balance i.e. Diuretics Recruitment manoeuvres such as prone ventilation, use of positive end expiratory pressure Mechanical ventilation strategy using low tidal volumes, as conventional tidal volumes may cause lung injury (only treatment found to improve survival rates)

Answer 1592

The T wave represents ventricular repolarization. The common sense approach to remembering this, is to acknowledge that ventricular repolarization is the last phase of cardiac contraction and should therefore correspond the the last part of the QRS complex. P wave Represents the wave of depolarization that spreads from the SA node throughout the atria Lasts 0.08 to 0.1 seconds (80-100 ms) The isoelectric period after the P wave represents the time in which the impulse is traveling within the AV node P-R interval Time from the onset of the P wave to the beginning of the QRS complex Ranges from 0.12 to 0.20 seconds in duration Represents the time between the onset of atrial depolarization and the onset of ventricular depolarization QRS complex Represents ventricular depolarization Duration of the QRS complex is normally 0.06 to 0.1 seconds ST segment Isoelectric period following the QRS Represents period which the entire ventricle is depolarized and roughly corresponds to the plateau phase of the ventricular action potential T wave Represents ventricular repolarization and is longer in duration than depolarization A small positive U wave may follow the T wave which represents the last remnants of ventricular repolarization. Q-T interval Represents the time for both ventricular depolarization and repolarization to occur, and therefore roughly estimates the duration of an average ventricular action potential. Interval ranges from 0.2 to 0.4 seconds depending upon heart rate. At high heart rates, ventricular action potentials shorten in duration, which decreases the Q-T interval. Therefore the Q-T interval is expressed as a 'corrected Q-T (QTc)' by taking the Q-T interval and dividing it by the square root of the R-R interval (interval between ventricular depolarizations). This allows an assessment of the Q-T interval that is independent of heart rate. Normal corrected Q-Tc interval is less than 0.44 seconds.

Answer 1593

The commonest event here is an anastomotic leak. It is possible that the patient (who has Crohns) originally had a colovesical fistula that was then addressed with a resection. In the event that these leak, the fistula reforms. Fistulas A fistula is defined as an abnormal connection between two epithelial surfaces. There are many types ranging from Branchial fistulae in the neck to entero-cutaneous fistulae abdominally. In general surgical practice the abdominal cavity generates the majority and most of these arise from diverticular disease and Crohn's. As a general rule all fistulae will resolve spontaneously as long as there is no distal obstruction. This is particularly true of intestinal fistulae. The four types of fistulae are: Enterocutaneous These link the intestine to the skin. They may be high (>500ml) or low output (<250ml) depending upon source. Duodenal /jejunal fistulae will tend to produce high volume, electrolyte rich secretions which can lead to severe excoriation of the skin. Colo-cutaneous fistulae will tend to leak faeculent material. Both fistulae may result from the spontaneous rupture of an abscess cavity onto the skin (such as following perianal abscess drainage) or may occur as a result of iatrogenic input. In some cases it may even be surgically desirable e.g. mucous fistula following sub total colectomy for colitis. Suspect if there is excess fluid in the drain. Enteroenteric or Enterocolic This is a fistula that involves the large or small intestine. They may originate in a similar manner to enterocutaneous fistulae. A particular problem with this fistula type is that bacterial overgrowth may precipitate malabsorption syndromes. This may be particularly serious in inflammatory bowel disease. Enterovaginal Aetiology as above. Enterovesical This type of fistula goes to the bladder. These fistulas may result in frequent urinary tract infections, or the passage of gas from the urethra during urination. Management Some rules relating to fistula management: They will heal provided there is no underlying inflammatory bowel disease and no distal obstruction, so conservative measures may be the best option Where there is skin involvement, protect the overlying skin, often using a well fitted stoma bag- skin damage is difficult to treat A high output fistula may be rendered more easily managed by the use of octreotide, this will tend to reduce the volume of pancreatic secretions. Nutritional complications are common especially with high fistula (e.g. high jejunal or duodenal) these may necessitate the use of TPN to provide nutritional support together with the concomitant use of octreotide to reduce volume and protect skin. When managing perianal fistulae surgeons should avoid probing the fistula where acute inflammation is present, this almost always worsens outcomes. When perianal fistulae occur secondary to Crohn's disease the best management option is often to drain acute sepsis and maintain that drainage through the judicious use of setons whilst medical management is implemented. Always attempt to delineate the fistula anatomy, for abscesses and fistulae that have an intra abdominal source the use of barium and CT studies should show a track. For perianal fistulae surgeons should recall Goodsall's rule in relation to internal and external openings.

Answer 1594

The baby is likely to be a victim of shaken baby syndrome. This may result in diffuse axonal injury causing extensive lesions in the white matter. Head injury Patients who suffer head injuries should be managed according to ATLS principles and extra cranial injuries should be managed alongside cranial trauma. Inadequate cardiac output will compromise CNS perfusion irrespective of the nature of the cranial injury. Types of traumatic brain injury Extradural haematoma Bleeding into the space between the dura mater and the skull. Often results from acceleration-deceleration trauma or a blow to the side of the head. The majority of extradural haematomas occur in the temporal region where skull fractures cause a rupture of the middle meningeal artery. Features Raised intracranial pressure Some patients may exhibit a lucid interval Subdural haematoma Bleeding into the outermost meningeal layer. Most commonly occur around the frontal and parietal lobes. May be either acute or chronic. Risk factors include old age and alcoholism. Slower onset of symptoms than a extradural haematoma. Subarachnoid haemorrhage Usually occurs spontaneously in the context of a ruptured cerebral aneurysm, but may be seen in association with other injuries when a patient has sustained a traumatic brain injury. Pathophysiology Primary brain injury may be focal (contusion/ haematoma) or diffuse (diffuse axonal injury) Diffuse axonal injury occurs as a result of mechanical shearing following deceleration, causing disruption and tearing of axons Intra-cranial haematomas can be extradural, subdural or intracerebral, while contusions may occur adjacent to (coup) or contralateral (contre-coup) to the side of impact Secondary brain injury occurs when cerebral oedema, ischaemia, infection, tonsillar or tentorial herniation exacerbates the original injury. The normal cerebral auto regulatory processes are disrupted following trauma rendering the brain more susceptible to blood flow changes and hypoxia The Cushings reflex (hypertension and bradycardia) often occurs late and is usually a pre terminal event Management Where there is life threatening rising ICP such as in extra dural haematoma and whilst theatre is prepared or transfer arranged use of IV mannitol/ frusemide may be required. Diffuse cerebral oedema may require decompressive craniotomy Exploratory Burr Holes have little management in modern practice except where scanning may be unavailable and to thus facilitate creation of formal craniotomy flap Depressed skull fractures that are open require formal surgical reduction and debridement, closed injuries may be managed non operatively if there is minimal displacement. ICP monitoring is appropriate in those who have GCS 3-8 and normal CT scan. ICP monitoring is mandatory in those who have GCS 3-8 and abnormal CT scan. Hyponatraemia is most likely to be due to syndrome of inappropriate ADH secretion. Minimum of cerebral perfusion pressure of 70mmHg in adults. Minimum cerebral perfusion pressure of between 40 and 70 mmHg in children. Interpretation of pupillary findings in head injuries Pupil size Light response Interpretation Unilaterally dilated Sluggish or fixed 3rd nerve compression secondary to tentorial herniation Bilaterally dilated Sluggish or fixed Poor CNS perfusion Bilateral 3rd nerve palsy Unilaterally dilated or equal Cross reactive (Marcus - Gunn) Optic nerve injury Bilaterally constricted May be difficult to assess Opiates Pontine lesions Metabolic encephalopathy Unilaterally constricted Preserved Sympathetic pathway disruption

Answer 1595

Multifocal breast cancer is best treated with mastectomy A combination of established axillary disease and multifocal invasive lesions attracts an indication for mastectomy and axillary clearance. A radical mastectomy is less frequently indicated in modern surgical practice, disease that is locally advanced is often best downstaged using medical therapy, rather than embarking on the operations for breast cancer that were first popularised over 100 years ago. Breast cancer management - Surgery is performed in most patients suffering from breast cancer. Chemotherapy may be used to downstage tumours and allow breast conserving surgery. Hormonal therapy may also be used for the same purposes. Radiotherapy is given to most patients who have undergone breast conserving surgery (some older patients receiving hormone treatment and who have small low grade tumours may safely avoid DXT. Therapeutic mammoplasty is an option for some patients but requires symmetrizing surgery in most cases. Patients who have undergone mastectomy may be offered a reconstructive procedure either in conjunction with their primary resection or as a staged procedure at a later date. Surgical options Mastectomy vs Wide local excision Mastectomy Wide Local Excision Multifocal tumour Solitary lesion Central tumour Peripheral tumour Large lesion in small breast Small lesion in large breast DCIS >4cm DCIS <4cm Patient Choice Patient choice Central lesions may be managed using breast conserving surgery, where an acceptable cosmetic result may be obtained, this is rarely the case in small breasts Axillary disease As a minimum, all patients with invasive breast cancer should have their axilla staged. In those who do not have overt evidence of axillary nodal involvement this can be undertaken using sentinel lymph node biopsy. Patients with a positive sentinel lymph node biopsy or who have imaging and cytological or histological evidence of axillary nodal metastasis should undergo axillary node clearance or axillary irradiation. Axillary node clearance is associated with the development of lymphoedema, increased risk of cellulitis and frozen shoulder.

Answer 1596

Core biopsy Vs fine needle aspiration cytology Core biopsy is preferred over FNAC by most surgeons. The reason for this is that FNAC often yielded inadequate tissue for assessment. When FNAC demonstrated benign changes, it had to be repeated at least once to confirm this. If it yielded cells that were indeterminate, then a core biopsy was needed. A core biopsy removes many of these stages and is thus more reliable. All discrete breast lumps, including those that seem benign, should have a confirmed histological diagnosis. In this case, a core biopsy has not yet been performed. This may yield a diagnosis that is concordant with imaging findings. In which case, this concludes the investigative process (if benign). If it remains unclear, excision biopsy will be needed.

Answer 1597

99% of males with cystic fibrosis will have absent vas. Absence of the vas deferens Absence of the vas may be unilateral or bilateral Cystic fibrosis CFTR gene mutations are the cause in 40% of cases Some non CF cases are due to unilateral renal agenesis Sperm harvesting may allow for assisted conception

Answer 1598

The loop diuretics can lead to marked increases in the amount of sodium excreted. They act in the medullary and cortical aspects of the thick ascending limb of the loop of Henle. This results in a decreased medullary concentration gradient and increases free water excretion (as well as loss of sodium). Because loop diuretics result in the loss of both sodium and water they are less frequently associated with hyponatraemia than thiazide diuretics (these latter agents act in the cortex and do not affect urine concentrating ability). Diuretic agents The diuretic drugs are divided into three major classes, which are distinguished according to the site at which they impair sodium reabsorption: loop diuretics in the thick ascending loop of Henle, thiazide type diuretics in the distal tubule and connecting segment; and potassium sparing diuretics in the aldosterone - sensitive principal cells in the cortical collecting tubule. In the kidney, sodium is reabsorbed through Na+/ K+ ATPase pumps located on the basolateral membrane. These pumps return reabsorbed sodium to the circulation and maintain low intracellular sodium levels. This latter effect ensures a constant concentration gradient. Physiological effects of commonly used diuretics Site of action Diuretic Carrier or channel inhibited Percentage of filtered sodium excreted Ascending limb of loop of Henle Frusemide Na+/K+ 2Cl - carrier Up to 25% Distal tubule and connecting segment Thiazides Na+Cl- carrier Between 3 and 5% Cortical collecting tubule Spironolactone Na+/K+ ATP ase pump Between 1 and 2%

Answer 1599

The azygos vein is routinely divided during an oesophagectomy to allow mobilisation. It arches anteriorly to insert into the SVC on the right hand side. Treatment of oesophageal cancer - In general resections are not offered to those patients with distant metastasis, and usually not to those with N2 disease. Local nodal involvement is not in itself a contra indication to resection. Surgical resection is the mainstay of treatment. Neoadjuvent chemotherapy is given in most cases prior to surgery. In situ disease may be managed by endoscopic mucosal resection, although this is still debated. In patients with lower third lesions an Ivor - Lewis type procedure is most commonly performed. Very distal tumours may be suitable to a transhiatal procedure. Which is an attractive option as the penetration of two visceral cavities required for an Ivor- Lewis type procedure increases the morbidity considerably. More proximal lesions will require a total oesphagectomy (Mckeown type) with anastomosis to the cervical oesophagus. Patients with unresectable disease may derive benefit from local ablative procedures, palliative chemotherapy or stent insertion. Operative details of Ivor- Lewis procedure Combined laparotomy and right thoracotomy Indication Lower and middle third oesophageal tumours Preparation Staging with a combination of CT chest abdomen and pelvis- if no metastatic disease detected then patients will undergo a staging laparoscopy to detect peritoneal disease. If both these modalities are negative then patients will finally undergo a PET CT scan to detect occult metastatic disease. Only in those whom no evidence of advanced disease is detected will proceed to resection. Patients receive a GA, double lumen endotracheal tube to allow for lung deflation, CVP and arterial monitoring. Procedure A rooftop incision is made to access the stomach and duodenum. Laparotomy To mobilize the stomach The greater omentum is incised away from its attachment to the right gastroepiploic vessels along the greater curvature of the stomach. Then the short gastric vessels are ligated and detached from the greater curvature from the spleen. The lesser omentum is incised, preserving the right gastric artery. The retroperitoneal attachments of the duodenum in its second and third portions are incised, allowing the pylorus to reach the oesophageal hiatus. Some surgeons perform a pyloroplasty at this point to facilitate gastric emptying. The left gastric vessels are then ligated, avoiding any injury to the common hepatic or splenic arteries. Care must be taken to avoid inadvertently devascularising the liver owing to variations in anatomy. Right Thoracotomy Oesophageal resection and oesophagogastric anastomosis Through 5th intercostal space Dissection performed 10cm above the tumour This may involve transection of the azygos vein. The oesophagus is then removed with the stomach creating a gastric tube. An anastomosis is created. The chest is closed with underwater seal drainage and tube drains to the abdominal cavity. Post operatively Patients will typically recover in ITU initially. A nasogastric tube will have been inserted intraoperatively and must remain in place during the early phases of recovery. Post operatively these patients are at relatively high risk of developing complications: * Atelectasis- due to the effects of thoracotomy and lung collapse * Anastomotic leakage. The risk is relatively high owing to the presence of a relatively devascularised stomach. Often the only blood supply is from the gastroepiploic artery as all others will have been divided. If a leak does occur then many will attempt to manage conservatively with prolonged nasogastric tube drainage and TPN. The reality is that up to 50% of patients developing an anastomotic leak will not survive to discharge. * Delayed gastric emptying (may be avoided by performing a pyloroplasty).

Answer 1600

Unlike most anaesthetic agents ketamine does not cause myocardial or marked respiratory depression. It is not associated with the adrenal suppression that may occur with etomidate. It is however, associated with a state of dissociative anaesthesia which patients may find distressing. Anaesthetic agents The table below summarises some of the more commonly used IV induction agents Agent Specific features Propofol Rapid onset of anaesthesia Pain on IV injection Rapidly metabolised with little accumulation of metabolites Proven anti emetic properties Moderate myocardial depression Widely used especially for maintaining sedation on ITU, total IV anaesthesia and for daycase surgery Sodium thiopentone Extremely rapid onset of action making it the agent of choice for rapid sequence of induction Marked myocardial depression may occur Metabolites build up quickly Unsuitable for maintenance infusion Little analgesic effects Ketamine May be used for induction of anaesthesia Has moderate to strong analgesic properties Produces little myocardial depression making it a suitable agent for anaesthesia in those who are haemodynamically unstable May induce state of dissociative anaesthesia resulting in nightmares Etomidate Has favorable cardiac safety profile with very little haemodynamic instability No analgesic properties Unsuitable for maintaining sedation as prolonged (and even brief) use may result in adrenal suppression Post operative vomiting is common

Answer 1601

This is most likely to be Peutz-Jeghers syndrome. Addisons and McCune Albright syndrome may produce similar skin changes but the intussusception resulting from polyps combined with the autosomal inheritance pattern makes this the most likely diagnosis. Peutz-Jeghers syndrome Peutz-Jeghers syndrome is an autosomal dominant condition characterised by numerous benign hamartomatous polyps in the gastrointestinal tract. It is also associated with pigmented freckles on the lips, face, palms and soles. Around 50% of patients will have died from a gastrointestinal tract cancer by the age of 60 years. Genetics Autosomal dominant Responsible gene encodes serine threonine kinase LKB1 or STK11 Features Hamartomatous polyps in GI tract (mainly small bowel) Pigmented lesions on lips, oral mucosa, face, palms and soles Intestinal obstruction e.g. intussusception (which may lead to diagnosis) Gastrointestinal bleeding Management Conservative unless complications develop

Answer 1602

Non steroidal anti inflammatory drugs may be nephrotoxic and therefore are usually avoided in patients who have undergone renal transplants. Paracetamol and morphine are metabolised predominantly in the liver. There is some renal contribution to morphine metabolism and excretion and the drug should be administered in reduced doses or avoided if the transplanted kidney stops functioning. Organ Transplant A number of different organ and tissue transplants are now available. In many cases an allograft is performed, where an organ is transplanted from one individual to another. Allografts will elicit an immune response and this is one of the main reasons for organ rejection. Graft rejection occurs because allografts have allelic differences at genes that code immunohistocompatability complex genes. The main antigens that give rise to rejection are: ABO blood group Human leucocyte antigens (HLA) Minor histocompatability antigens ABO Matching ABO incompatibility will result in early organ rejection (hyperacute) because of pre existing antibodies to other groups. Group O donors can give organs to any type of ABO recipient whereas group AB donor can only donate to AB recipient. HLA System The four most important HLA alleles are: HLA A HLA B HLA C HLA DR An ideal organ match would be one in which all 8 alleles are matched (remember 2 from each parent, four each = 8 alleles). Modern immunosuppressive regimes help to manage the potential rejection due to HLA mismatching. However, the greater the number of mismatches the worse the long term outcome will be. T lymphocytes will recognise antigens bound to HLA molecules and will then become activated. Clonal expansion then occurs with a response directed against that antigen. Types of organ rejection Hyperacute. This occurs immediately through presence of pre formed antibodies (such as ABO incompatibility). Acute. Occurs during the first 6 months and is usually T cell mediated. Usually tissue infiltrates and vascular lesions. Chronic. Occurs after the first 6 months. Vascular changes predominate. Hyperacute Renal transplants at greatest risk and liver transplants at least risk. Although ABO incompatibility and HLA Class I incompatible transplants will all fare worse in long term. Acute All organs may undergo acute rejection. Mononuclear cell infiltrates predominate. All types of transplanted organ are susceptible and it may occur in up to 50% cases. Chronic Again all transplants with HLA mismatch may suffer this fate. Previous acute rejections and other immunosensitising events all increase the risk. Vascular changes are most prominent with myointimal proliferation leading to organ ischaemia. Organ specific changes are also seen such as loss of acinar cells in pancreas transplants and rapidly progressive coronary artery disease in cardiac transplants. Surgical overview-Renal transplantation A brief overview of the steps involved in renal transplantation is given. Patients with end stage renal failure who are dialysis dependent or likely to become so in the immediate future are considered for transplant. Exclusion criteria include; active malignancy, old age (due to limited organ availability). Patients are medically optimised. Donor kidneys, these may be taken from live related donors and close family, members may have less HLA mismatch than members of the general population. Laparoscopic donor nephrectomy further minimises the operative morbidity for the donor. Other organs are typically taken from brain dead or dying patients who have a cardiac arrest and in whom resuscitation is futile. The key event is to minimise the warm ischaemic time in the donor phase. The kidney once removed is usually prepared on the bench in theatre by the transplant surgeon immediately prior to implantation and factors such as accessory renal arteries and vessel length are assessed and managed. For first time recipients the operation is performed under general anaesthesia. A Rutherford-Morison incision is made on the preferred side. This provides excellent extraperitoneal access to the iliac vessels. The external iliac artery and vein are dissected out and following systemic heparinisation are cross clamped. The vein and artery are anastamosed to the iliacs and the clamps removed. The ureter is then implanted into the bladder and a stent is usually placed to maintain patency. The wounds are then closed and the patient recovered from surgery. In the immediate phase a common problem encountered in cadaveric kidneys is acute tubular necrosis and this tends to resolve. Graft survival times from cadaveric donors are typically of the order of 9 years and monozygotic twin transplant (live donor) may survive as long as 25 years.

Answer 1603

The blood supply to the femoral head may be intact and the fracture should heal with compression type devices such as gamma nails or dynamic hip screws. The latter device being the most commonly performed therapeutic intervention. Hip fractures Background Neck of femur (NOF) fracture is a common orthopaedic presentation, with over 65000 fractures in the UK per year. Like many orthopaedic injuries, there is a bimodal age distribution. It is imperative to distinguish between the high energy injury in a young patient, and the low energy osteoporotic fracture in the elderly, as their management aims are very different: Young patient - Usually high energy trauma (e.g road traffic accident, horse riding) and needs treating in accordance with Advanced Trauma Life Support (ATLS) principles. Will often have associated injuries. Aim is to retain the patients own anatomy, and optimise their function. Elderly patient - Predominantly female, fall from standing height (fragility fracture). Often patients have multiple comorbidities that will ultimately dictate their prognosis. Aim of orthopaedic treatment is to immediately regain patient mobility so that morbidity (infection, thromboembolic events, pressure sores etc) and mortality associated with prolonged bed rest is avoided. Left untreated, a neck of femur fracture can be considered a terminal event. Historically, mortality associated with elderly hip fracture is 10% at one month, and 30% at one year. However, this has been improved in the UK with the introduction of multidisciplinary, orthogeriatric lead care and the National Hip Fracture Database and Best Practice Tariff. Pertinent anatomy Osteology - normal neck-shaft angle is 130 +/- 7 degrees, and 10 +/- 7 degrees of neck anteversion. Vascular supply - The predominant blood supply to the femoral head and neck is from the medial and lateral femoral circumflex arteries (branches of profunda femoris). These anastomose and pierce the joint capsule at the base of the neck, mainly posteriorly. There is a small vascular contribution from the artery of the ligament teres. Understanding the blood supply is fundamental to the decision making process in treating NOF fractures. Presentation and initial management Typically, patients present with pain in the hip/groin, a shortened, abducted, externally rotated leg (due to the unopposed pull of the muscles that act across the hip joint) and the inability to straight-leg-raise. With undisplaced fractures, signs are more subtle. High energy injuries should be treated in line with ATLS principles. All patients should be fluid resuscitated, have adequate pain relief (often with a fascio-iliiaca nerve block), and be optimised for surgery. In addition, elderly patients should be assessed by an orthogeriatrician. Imaging Anteroposterior and cross-table lateral plain radiographs are sufficient to diagnose the majority of NOF fractures. If the fracture extends below the level of the lesser trochanter, or there is any possibility of pathological fracture, full length femur views are essential to plan surgery. Where there is a high index of suspicion of fracture, but plain radiographs are inconclusive, gold standard investigation is MRI. However, if unavailable within 24 hours, or if the patient will not tolerate MRI, CT is appropriate. The majority of fractures can be seen with modern CT techniques, and so this is becoming first line in many hospitals. Classification There has been a move away from named classification systems towards descriptive classification systems. Two main types of NOF exist: Intra-capsular, and extra-capsular. Extra-capsular fractures are further divided into pertrochanteric or subtrochanteric (within 5cm distal to the lesser trochanter). All fractures are then described as undisplaced, minimally displaced, or displaced. Femoral neck and head blood supply disruption is common with intracapsular NOF fractures, and rare with extracapsular fractures. This fundamental principle underpins the practise of arthroplasty for intracapsular fractures, and fixation for extracapsular fractures. If you wish to use a named classification system, the most commonly used are below: Elderly intracapsular - Garden Classification Young intrasapsular - Pauvels Classification Intertrochanteric - Evans Subtrochanteric - Russell Taylor Treatment In general, NOF fractures are treated operatively except if the patient is deemed unlikely to survive an anaesthetic. Best Practice Tarif (BPT) dictates that surgery should happen within 36 hours, as delay of greater than 48 hours is associated with increased morbidity and mortality. Below are suggested algorithms for the treatment of NOF. There are some areas of debate/controversy which are detailed below. * The priority with the young patient is to retain the femoral head if possible, even with a displaced intracapsular fracture. The risk of avascular necrosis and non-union (and therefore revision surgery) associated with internal fixation needs weighing up against the sequelae of total hip replacement in the young (wear, dislocation, revision). Discussion is necessary with the patient, on a case by case basis. ** Undisplaced fractures in the elderly can be treated with internal fixation, often with cannulated screws. This is appropriate for valgus impacted subcapital fractures which are inherently stable, to prevent secondary displacement. This does still carry the risk of AVN or non-union, and therefore a future revision. For this reason, many surgeons advocate arthroplasty as a single surgery. *** NICE guidance - patients who fulfil these criteria should be offered total hip replacement which conveys better function and prosthetic survivorship, compared with hemiarthroplasty, but at an increased risk of dislocation. * Intertrochanteric fractures vary greatly in their stability. If the trochanter (and therefore lateral wall), and medial calcar is in tact, then the fracture configuration bears stability. This can be treated with a DHS, as collapse of the fracture is predictable. Where either or both structures are involved in the fracture, stability becomes compromised and many surgeons will favour using an intramedullary device. This is an ongoing debate, and difficult to test in an exam setting. Post operative management Patients should be mobilised fully weight bearing where possible. Care is multidisciplinary in its delivery. Elderly patients should have orthogeriatrician assessment of comorbidity, and bone health with secondary prevention measures if appropriate. There should be early involvement of physiotherapy and occupational therapy services. For further guidance see sources listed below. NICE clinical guidance on hip fracture: https://www.nice.org.uk/guidance/cg124 Best Practice Tarif: www.nhfd.co.uk/20/hipfractureR.../Best%20Practice%20Tariff%20User%20Guide.pdf National Hip Fracture Database: www.nhfd.co.uk/

Answer 1604

A six month history of dysphagia is a relatively long history and makes malignancy less likely. The lesion should be biopsied for histological confirmation. Long standing oesophagitis may be complicated by the development of strictures, Barretts oesophagus or both. Oesophageal disease Disorder Features Mallory-Weiss Tear Usually history of antecedent vomiting. This is then followed by the vomiting of a small amount of blood. There is usually little in the way of systemic disturbance or prior symptoms. Hiatus hernia of gastric cardia Often longstanding history of dyspepsia, patients are often overweight. Uncomplicated hiatus hernias should not be associated with dysphagia or haematemesis. Oesophageal rupture Complete disruption of the oesophageal wall in absence of pre-existing pathology. Left postero-lateral oesophageal is commonest site (2-3cm from OG junction). Suspect in patients with severe chest pain without cardiac diagnosis and signs suggestive of pneumonia without convincing history, where there is history of vomiting. Erect CXR shows infiltrate or effusion in 90% of cases(1). Squamous cell carcinoma of the oesophagus History of progressive dysphagia. Often signs of weight loss. Usually little or no history of previous GORD type symptoms. Adenocarcinoma of the oesophagus Progressive dysphagia, may have previous symptoms of GORD or Barretts oesophagus. Peptic stricture Longer history of dysphagia, often not progressive. Usually symptoms of GORD. Often lack systemic features seen with malignancy Dysmotility disorder May have dysphagia that is episodic and non progressive. Retrosternal pain may accompany the episodes. Diagnosis Most of the differential diagnoses listed above can be accurately categorised by upper GI endoscopy (usually most patients). Where this fails to demonstrate a mechanical stricture the use of pH and manometry studies together with radiological contrast swallows will facilitate the diagnosis. References Blencowe N et al. Spontaneous oesophageal rupture. BMJ 2013 (346):38-39.

Answer 1605

The glossopharyngeal nerve supplies this area and the ear and otalgia may be the result of referred pain. Cranial nerves Cranial nerve lesions Olfactory nerve May be injured in basal skull fractures or involved in frontal lobe tumour extension. Loss of olfactory nerve function in relation to major CNS pathology is seldom an isolated event and thus it is poor localiser of CNS pathology. Optic nerve Problems with visual acuity may result from intra ocular disorders. Problems with the blood supply such as amaurosis fugax may produce temporary visual distortion. More important surgically is the pupillary response to light. The pupillary size may be altered in a number of disorders. Nerves involved in the resizing of the pupil connect to the pretectal nucleus of the high midbrain, bypassing the lateral geniculate nucleus and the primary visual cortex. From the pretectal nucleus neurones pass to the Edinger - Westphal nucleus, motor axons from here pass along with the oculomotor nerve. They synapse with ciliary ganglion neurones; the parasympathetic axons from this then innervate the iris and produce miosis. The miotic pupil is seen in disorders such as Horner's syndrome or opiate overdose. Mydriasis is the dilatation of the pupil in response to disease, trauma, drugs (or the dark!). It is pathological when light fails to induce miosis. The radial muscle is innervated by the sympathetic nervous system. Because the parasympathetic fibres travel with the oculomotor nerve they will be damaged by lesions affecting this nerve (e.g. cranial trauma). The response to light shone in one eye is usually a constriction of both pupils. This indicates intact direct and consensual light reflexes. When the optic nerve has an afferent defect the light shining on the affected eye will produce a diminished pupillary response in both eyes. Whereas light shone on the unaffected eye will produce a normal pupillary response in both eyes. This is referred to as the Marcus Gunn pupil and is seen in conditions such as optic neuritis. In a total CN II lesion shining the light in the affected eye will produce no response. Oculomotor nerve The pupillary effects are described above. In addition it supplies all ocular muscles apart from lateral rectus and superior oblique. Thus the affected eye will be deviated inferolaterally. Levator palpebrae superioris may also be impaired resulting in impaired ability to open the eye. Trochlear nerve The eye will not be able to look down. Trigeminal nerve Largest cranial nerve. Exits the brainstem at the pons. Branches are ophthalmic, maxillary and mandibular. Only the mandibular branch has both sensory and motor fibres. Branches converge to form the trigeminal ganglion (located in Meckels cave). It supplies the muscles of mastication and also tensor veli palatine, mylohyoid, anterior belly of digastric and tensor tympani. The detailed descriptions of the various sensory functions are described in other areas of the website. The corneal reflex is important and is elicited by applying a small tip of cotton wool to the cornea, a reflex blink should occur if it is intact. It is mediated by: the naso ciliary branch of the ophthalmic branch of the trigeminal (sensory component) and the facial nerve producing the motor response. Lesions of the afferent arc will produce bilateral absent blink and lesions of the efferent arc will result in a unilateral absent blink. Abducens nerve The affected eye will have a deficit of abduction. This cranial nerve exits the brainstem between the pons and medulla. It thus has a relatively long intra cranial course which renders it susceptible to damage in raised intra cranial pressure. Facial nerve Emerges from brainstem between pons and medulla. It controls muscles of facial expression and taste from the anterior 2/3 of the tongue. The nerve passes into the petrous temporal bone and into the internal auditory meatus. It then passes through the facial canal and exits at the stylomastoid foramen. It passes through the parotid gland and divides at this point. It does not innervate the parotid gland. Its divisions are considered in other parts of the website. Its motor fibres innervate orbicularis oculi to produce the efferent arm of the corneal reflex. In surgical practice it may be injured during parotid gland surgery or invaded by malignancies of the gland and a lower motor neurone on the ipsilateral side will result. Vestibulo-cochlear nerve Exits from the pons and then passes through the internal auditory meatus. It is implicated in sensorineural hearing loss. Individuals with sensorineural hearing loss will localise the sound in webers test to the normal ear. Rinnes test will be reduced on the affected side but should still work. These two tests will distinguish sensorineural hearing loss from conductive deafness. In the latter condition webers test will localise to the affected ear and Rinnes test will be impaired on the affected side. Surgical lesions affecting this nerve include CNS tumours and basal skull fractures. It may also be damaged by the administration of ototoxic drugs (of which gentamicin is the most commonly used in surgical practice). Glossopharyngeal nerve Exits the pons just above the vagus. Receives sensory fibres from posterior 1/3 tongue, tonsils, pharynx and middle ear (otalgia may occur following tonsillectomy). It receives visceral afferents from the carotid bodies. It supplies parasympathetic fibres to the parotid gland via the otic ganglion and motor function to stylopharyngeaus muscle. The sensory function of the nerve is tested using the gag reflex. Vagus nerve Leaves the medulla between the olivary nucleus and the inferior cerebellar peduncle. Passes through the jugular foramen and into the carotid sheath. Details of the functions of the vagus nerve are covered in the website under relevant organ sub headings. Accessory nerve Exists from the caudal aspect of the brainstem (multiple branches) supplies trapezius and sternocleidomastoid muscles. The distal portion of this nerve is most prone to injury during surgical procedures. Hypoglossal nerve Emerges from the medulla at the preolivary sulcus, passes through the hypoglossal canal. It lies on the carotid sheath and passes deep to the posterior belly of digastric to supply muscles of the tongue (except palatoglossus). Its location near the carotid sheath makes it vulnerable during carotid endarterectomy surgery and damage will produce ipsilateral defect in muscle function.

Answer 1606

Meckels diverticulum is the number one cause of painless massive GI bleeding requiring a transfusion in children between the ages of 1 and 2 years. Other causes of GI bleeding include: Site Newborn 1 month to 1 year 1 to 2 years Older than 2 years Upper GI tract Haemorrhagic disease, swallowed maternal blood Oesophagitis/ gastritis Peptic ulcer disease Varices Lower GI tract Anal fissure/ NEC Anal fissure/ Intussusception Polyps / Meckels diverticulum IBD/ Polyps/ Intussusception Meckel's diverticulum - Congenital abnormality resulting in incomplete obliteration of the vitello-intestinal duct Normally, in the foetus, there is an attachment between the vitello-intestinal duct and the yolk sac.This disappears at 6 weeks gestation. The tip is free in majority of cases. Associated with enterocystomas, umbilical sinuses, and omphaloileal fistulas. Arterial supply: omphalomesenteric artery. 2% of population, 2 inches long, 2 feet from the ileocaecal valve. Typically lined by ileal mucosa but ectopic gastric mucosa can occur, with the risk of peptic ulceration. Pancreatic and jejunal mucosa can also occur. Clinical Normally asymptomatic and an incidental finding. Complications are the result of obstruction, ectopic tissue, or inflammation. Removal if narrow neck or symptomatic. Options are between wedge excision or formal small bowel resection and anastomosis.

Answer 1607

The thebesian veins are numerous small veins running over the surface of the heart they drain into the heart itself. Usually this is to the atrium directly. Heart anatomy The walls of each cardiac chamber comprise: Epicardium Myocardium Endocardium Cardiac muscle is attached to the cardiac fibrous skeleton. Relations The heart and roots of the great vessels within the pericardial sac are related to the posterior aspect of the sternum, medial ends of the 3rd to 5th ribs on the left and their associated costal cartilages. The heart and pericardial sac are situated obliquely two thirds to the left and one third to the right of the median plane. The pulmonary valve lies at the level of the left third costal cartilage. The mitral valve lies at the level of the fourth costal cartilage. Coronary sinus This lies in the posterior part of the coronary groove and receives blood from the cardiac veins. The great cardiac vein lies at its left and the middle and small cardiac veins lie on its right. The smallest cardiac vein (anterior cardiac vein) drains into the right atrium directly. Aortic sinus Right coronary artery arises from the right aortic sinus, the left is derived from the left aortic sinus, which lies posteriorly. Features of the left ventricle as opposed to the right Structure Left Ventricle A-V Valve Mitral (double leaflet) Walls Twice as thick as right Trabeculae carnae Much thicker and more numerous Right coronary artery The RCA supplies: Right atrium Diaphragmatic part of the right ventricle Usually the posterior third of the interventricular septum The sino atrial node (60% cases) The atrio ventricular node (80% cases) Left coronary artery The LCA supplies: Left atrium Most of left ventricle Part of the right ventricle Anterior two thirds of the inter ventricular septum The sino atrial node (remaining 40% cases) Innervation of the heart Autonomic nerve fibres from the superficial and deep cardiac plexus. These lie anterior to the bifurcation of the trachea, posterior to the ascending aorta and superior to the bifurcation of the pulmonary trunk. The parasympathetic supply to the heart is from presynaptic fibres of the vagus nerves. Valves of the heart Mitral valve Aortic valve Pulmonary valve Tricuspid valve 2 cusps 3 cusps 3 cusps 3 cusps First heart sound Second heart sound Second heart sound First heart sound 1 anterior cusp 2 anterior cusps 2 anterior cusps 2 anterior cusps Attached to chordae tendinae No chordae No chordae Attached to chordae tendinae

Answer 1608

The left colon is embryologically part of the hind gut. Which accounts for its separate blood supply via the IMA. Colon anatomy The colon commences with the caecum. This represents the most dilated segment of the human colon and its base (which is intraperitoneal) is marked by the convergence of teniae coli. At this point is located the vermiform appendix. The colon continues as the ascending colon, the posterior aspect of which is retroperitoneal. The line of demarcation between the intra and retro peritoneal right colon is visible as a white line, in the living, and forms the line of incision for colonic resections. The ascending colon becomes the transverse colon after passing the hepatic flexure. At this location the colon becomes wholly intra peritoneal once again. The superior aspect of the transverse colon is the point of attachment of the transverse colon to the greater omentum. This is an important anatomical site since division of these attachments permits entry into the lesser sac. Separation of the greater omentum from the transverse colon is a routine operative step in both gastric and colonic resections. At the left side of the abdomen the transverse colon passes to the left upper quadrant and makes an oblique inferior turn at the splenic flexure. Following this, the posterior aspect becomes retroperitoneal once again. At the level of approximately L4 the descending colon becomes wholly intraperitoneal and becomes the sigmoid colon. Whilst the sigmoid is wholly intraperitoneal there are usually attachments laterally between the sigmoid and the lateral pelvic sidewall. These small congenital adhesions are not formal anatomical attachments but frequently require division during surgical resections. At its distal end the sigmoid passes to the midline and at the region around the sacral promontary it becomes the upper rectum. This transition is visible macroscopically as the point where the teniae fuse. More distally the rectum passes through the peritoneum at the region of the peritoneal reflection and becomes extraperitoneal. Arterial supply Superior mesenteric artery and inferior mesenteric artery: linked by the marginal artery. Ascending colon: ileocolic and right colic arteries Transverse colon: middle colic artery Descending and sigmoid colon: inferior mesenteric artery Venous drainage From regional veins (that accompany arteries) to superior and inferior mesenteric vein Lymphatic drainage Initially along nodal chains that accompany supplying arteries, then para-aortic nodes. Embryology Midgut- Second part of duodenum to 2/3 transverse colon Hindgut- Distal 1/3 transverse colon to anus Peritoneal location The right and left colon are part intraperitoneal and part extraperitoneal. The sigmoid and transverse colon are generally wholly intraperitoneal. This has implications for the sequelae of perforations, which will tend to result in generalised peritonitis in the wholly intra peritoneal segments. Colonic relations Region of colon Relation Caecum/ right colon Right ureter, gonadal vessels Hepatic flexure Gallbladder (medially) Splenic flexure Spleen and tail of pancreas Distal sigmoid/ upper rectum Left ureter Rectum Ureters, autonomic nerves, seminal vesicles, prostate, urethra (distally)

Answer 1609

Anticoagulation will worsen compartment syndrome. Compartment syndrome - This is a particular complication that may occur following fractures (or following ischaemia re-perfusion injury in vascular patients). It is characterised by raised pressure within a closed anatomical space. The raised pressure within the compartment will eventually compromise tissue perfusion resulting in necrosis. The two main fractures carrying this complication include supracondylar fractures and tibial shaft injuries. Symptoms and signs Pain, especially on movement (even passive) Parasthesiae Pallor may be present Arterial pulsation may still be felt as the necrosis occurs as a result of microvascular compromise Paralysis of the muscle group may occur Diagnosis Is made by measurement of intracompartmental pressure measurements. Pressures in excess of 20mmHg are abnormal and >40mmHg is diagnostic. Treatment This is essentially prompt and extensive fasciotomies In the lower limb the deep muscles may be inadequately decompressed by the inexperienced operator when smaller incisions are performed Myoglobinuria may occur following fasciotomy and result in renal failure and for this reason these patients require aggressive IV fluids Where muscle groups are frankly necrotic at fasciotomy they should be debrided and amputation may have to be considered Death of muscle groups may occur within 4-6 hours

Answer 1610

Surgery is indicated in less than 10% of cases. However, severe deformity is one of the indications for surgery. Lymphovenous anastomosis is indicated where the proximal lymphatics are not patent. When the overlying skin is healthy (and limb deformity a problem), a Homans procedure is a reasonable first line operative option. Lymphoedema - Due to impaired lymphatic drainage in the presence of normal capillary function. Lymphoedema causes the accumulation of protein rich fluid, subdermal fibrosis and dermal thickening. Characteristically fluid is confined to the epifascial space (skin and subcutaneous tissues); muscle compartments are free of oedema. It involves the foot, unlike other forms of oedema. There may be a 'buffalo hump' on the dorsum of the foot and the skin cannot be pinched due to subcutaneous fibrosis. Causes of lymphoedema Primary Congenital < 1 year: sporadic, Milroy's disease Onset 1-35 years: sporadic, Meige's disease > 35 years: Tarda Secondary Bacterial/fungal/parasitic infection (filariasis) Lymphatic malignancy Radiotherapy to lymph nodes Surgical resection of lymph nodes DVT Thrombophlebitis Indications for surgery Marked disability or deformity from limb swelling Lymphoedema caused by proximal lymphatic obstruction with patent distal lymphatics suitable for a lymphatic drainage procedure Lymphocutaneous fistulae and megalymphatics Procedures Homans operation Reduction procedure with preservation of overlying skin (which must be in good condition). Skin flaps are raised and the underlying tissue excised. Limb circumference typically reduced by a third. Charles operation All skin and subcutaneous tissue around the calf are excised down to the deep fascia. Split skin grafts are placed over the site. May be performed if overlying skin is not in good condition. Larger reduction in size than with Homans procedure. Lymphovenous anastamosis Identifiable lymphatics are anastomosed to sub dermal venules. Usually indicated in 2% of patients with proximal lymphatic obstruction and normal distal lymphatics.

Answer 1611

Pilar cysts may contain foul smelling cheesy material and are surrounded by the outer part of a hair follicle. Because of their histological appearances they are more correctly termed pilar cysts than sebaceous cysts. Benign skin diseases Seborrhoeic keratosis Most commonly arise in patients over the age of 50 years, often idiopathic Equal sex incidence and prevalence Usually multiple lesions over face and trunk Flat, raised, filiform and pedunculated subtypes are recognised Variable colours and surface may have greasy scale overlying it Treatment options consist of leaving alone or simple shave excision Melanocytic naevi Congenital melanocytic naevi Typically appear at, or soon after, birth Usually greater than 1cm diameter Increased risk of malignant transformation (increased risk greatest for large lesions) Junctional melanocytic naevi Circular macules May have heterogeneous colour even within same lesion Most naevi of the palms, soles and mucous membranes are of this type Compound naevi Domed pigmented nodules up to 1cm in diameter Arise from junctional naevi, usually have uniform colour and are smooth Spitz naevus Usually develop over a few months in children May be pink or red in colour, most common on face and legs May grow up to 1cm and growth can be rapid, this usually results in excision Atypical naevus syndrome Atypical melanocytic naevi that may be autosomally dominantly inherited Some individuals are at increased risk of melanoma (usually have mutations of CDKN2A gene) Many people with atypical naevus syndrome AND a parent sibling with melanoma will develop melanoma Epidermoid cysts Common and affect face and trunk They have a central punctum, they may contain small quantities of sebum The cyst lining is either normal epidermis (epidermoid cyst) or outer root sheath of hair follicle (pilar cyst) Dermatofibroma Solitary dermal nodules Usually affect extremities of young adults Lesions feel larger than they appear visually Histologically they consist of proliferating fibroblasts merging with sparsely cellular dermal tissues Painful skin lesions Eccrine spiradenoma Neuroma Glomus tumour Leiomyoma Angiolipoma Neurofibroma (rarely painful) and dermatofibroma (rarely painful)

Answer 1612

Mild pyrexia during blood transfusion is the most common event and commonly occurs during transfusion. Blood transfusion reactions Acute transfusion reactions present as adverse signs or symptoms during or within 24 hours of a blood transfusion. The most frequent reactions are fever, chills, pruritus, or urticaria, which typically resolve promptly without specific treatment or complications. Other signs occurring in temporal relationship with a blood transfusion, such as severe dyspnoea, pyrexia, or loss of consciousness may be the first indication of a more severe potentially fatal reaction. The causes of adverse reactions are multi-factorial. Immune mediated reactions, some of the most feared, occur as a result of component mismatch, the commonest cause of which is clerical error. More common, non immune mediated, complications may occur as a result of product contamination, this may be bacterial or viral. Transfusion related lung injury is well recognised and there are two proposed mechanisms which underpin this. One involves the sequestration of primed neutrophils within the recipient pulmonary capillary bed. The other proposed mechanism suggests that HLA mismatches between donor neutrophils and recipient lung tissue is to blame. The table below summarises the main types of transfusion reaction. Immune mediated Non immune mediated Pyrexia Hypocalcaemia Alloimmunization CCF Thrombocytopaenia Infections Transfusion associated lung injury Hyperkalaemia Graft vs Host disease Urticaria Acute or delayed haemolysis ABO incompatibility Rhesus incompatibility

Answer 1613

Dercums disease is characterized by multiple lipomas. It is also referred to as adiposis dolorosa. Dercums disease Condition in which there is generalized obesity and multiple fatty tumours within adipose tissue Lesions are usually multiple and found around extremity joints Commonest in females Typically presents in middle age Treatments include analgesia and occasionally resection of the lesions, recurrence, however, is common

Answer 1614

The timing of the pain and the fact that it is mid cycle makes Mittelschmerz the most likely cause. When follicular cysts rupture, there is sometimes associated bleeding of small volume. The cyst contents and blood if present can be very irritant and pain can sometimes mimic appendicitis or pelvic inflammatory disease. However, normal inflammatory markers makes the former less likely and unless the 14 year old was sexually active, PID is also relatively rare in this group. Crohns disease and pelvic abscesses would typically present with a more protracted history and raised inflammatory markers and fever. Right iliac fossa pain Differential diagnosis Appendicitis Pain radiating to right iliac fossa Anorexia (very common) Short history Diarrhoea and profuse vomiting rare Crohn's disease Often long history Signs of malnutrition Change in bowel habit, especially diarrhoea Mesenteric adenitis Mainly affects children Causes include Adenoviruses, Epstein Barr Virus, beta-haemolytic Streptococcus, Staphylococcus spp., Escherichia coli, Streptococcus viridans and Yersinia spp. Patients have a higher temperature than those with appendicitis If laparotomy is performed, enlarged mesenteric lymph nodes will be present Diverticulitis Both left and right sided disease may present with right iliac fossa pain Clinical history may be similar, although some change in bowel habit is usual When suspected, a CT scan may help in refining the diagnosis Meckel's diverticulitis A Meckel's diverticulum is a congenital abnormality that is present in about 2% of the population Typically 2 feet proximal to the ileocaecal valve May be lined by ectopic gastric mucosal tissue and produce bleeding Perforated peptic ulcer This usually produces upper quadrant pain but pain may be lower Perforations typically have a sharp sudden onset of pain in the history Incarcerated right inguinal or femoral hernia Usually only right iliac fossa pain if right sided or bowel obstruction. Bowel perforation secondary to caecal or colon carcinoma Seldom localised to right iliac fossa, although complete large bowel obstruction with caecal distension may cause pain prior to perforation. Gynaecological causes Pelvic inflammatory disease/salpingitis/pelvic abscess/Ectopic pregnancy/Ovarian torsion/Threatened or complete abortion/Mittelschmerz Urological causes Ureteric colic/UTI/Testicular torsion Other causes TB/Typhoid/Herpes Zoster/AAA/Situs inversus

Answer 1615

Neutrophil polymorphs are the cell type most commonly encountered in acute inflammation. Acute inflammation Inflammation is the reaction of the tissue elements to injury. Vascular changes occur, resulting in the generation of a protein rich exudate. So long as the injury does not totally destroy the existing tissue architecture, the episode may resolve with restoration of original tissue architecture. Vascular changes Vasodilation occurs and persists throughout the inflammatory phase. Inflammatory cells exit the circulation at the site of injury. The equilibrium that balances Starlings forces within capillary beds is disrupted and a protein rich exudate will form as the vessel walls also become more permeable to proteins. The high fibrinogen content of the fluid may form a fibrin clot. This has several important immunomodulatory functions. Sequelae Resolution Typically occurs with minimal initial injury Stimulus removed and normal tissue architecture results Organisation Delayed removal of exudate Tissues undergo organisation and usually fibrosis Suppuration Typically formation of an abscess or an empyema Sequestration of large quantities of dead neutrophils Progression to chronic inflammation Coupled inflammatory and reparative activities Usually occurs when initial infection or suppuration has been inadequately managed Causes Infections e.g. Viruses, exotoxins or endotoxins released by bacteria Chemical agents Physical agents e.g. Trauma Hypersensitivity reactions Tissue necrosis Presence of neutrophil polymorphs is a histological diagnostic feature of acute inflammation

Answer 1616

A short history of pain together with clinical examination and radiological signs affecting the second metatarsal favour a stress fracture. The fact that callus is present suggests that immobilisation is unlikely to be beneficial. Freibergs disease is an anterior metatarsalgia affecting the head of the second metarsal, it typically occurs in the pubertal growth spurt. The initial injury was thought to be due to stress microfractures at the growth plate. The key feature in the history which distinguishes the injury as being stress fracture is the radiology. In Freibergs disease the x-ray changes include; joint space widening, formation of bony spurs, sclerosis and flattening of the metatarsal head. Stress fractures Repetitive activity and loading of normal bone may result in small hairline fractures. Whilst these may be painful they are seldom displaced. Surrounding soft tissue injury is unusual. They may present late following the injury, in which case callus formation may be identified on radiographs. Such cases may not require formal immobilisation, injuries associated with severe pain and presenting at an earlier stage may benefit from immobilisation tailored to the site of injury.

Answer 1617

It begins at C5 and has 5 roots. It ends with a total of 15 nerves of these 5 are the main nerves to the upper limb (axillary, radial, ulnar, musculocutaneous and median) Brachial plexus The brachial plexus extends from the neck to the axilla. It is formed by the ventral rami of the fifth to the eighth cervical nerves with the ascending part of the first thoracic nerve. Location of the plexus The ventral rami which form the plexus enter the lower part of the posterior triangle of the neck in series with the ventral rami of the cervical plexus. The second part of the subclavian artery lies immediately anterior to the lower two rami. The upper three rami intermingle and pass inferolaterally towards the axilla and subclavian artery. They are enclosed within an extension of the prevertebral fascia. In the neck the plexus lies deep to platysma, the supraclavicular nerves, inferior belly of omohyoid and the transverse cervical artery. It then passes deep to the clavicle and the suprascapular vessels, to enter the axilla, and thence surround the second part of the axillary artery Composition of the plexus Ventral rami, the roots of the plexus, lie between scalenus medius and anterior. As they enter the posterior triangle, the upper two (C5,6) and lower two (C8, T1) roots of the plexus unite to form the upper and lower trunks of the plexus respectively. Meanwhile, C7 continues as the middle trunk. The lower trunk may groove the superior surface of the first rib posterior to the subclavian artery, and the root from the first ventral ramus is always in contact with it. Each trunk divides into ventral and dorsal divisions which are destined to supply the anterior (flexor) and posterior (extensor) parts of the upper limb. The cords of the plexus are formed in the axilla. The dorsal divisions unite to form the posterior cord (C5-8). The ventral divisions of the upper and middle trunks unite to form the lateral cord (C5-7), while the ventral divisions of the lower trunk continues as the medial cord (C8-T1). The cords are named according to their relationship to the axillary artery. Each cord terminates by dividing into two main branches at the beginning of the third part of the artery. Sympathetic communications The fifth and sixth cervical ventral rami receive grey rami communicantes from the middle cervical ganglion, while the two or more grey rami communicantes pass from the inferior cervical ganglion to the seventh and eighth cervical ventral rami. The first thoracic ventral ramus receives its grey ramus from the cervicothoracic ganglion. Its for this reason that inferior plexus injury can be complicated by a Horners syndrome. Summary Origin Anterior rami of C5 to T1 Sections of the plexus Roots, trunks, divisions, cords, branches Mnemonic:Real Teenagers Drink Cold Beer Roots Located in the posterior triangle Pass between scalenus anterior and medius Trunks Located posterior to middle third of clavicle Upper and middle trunks related superiorly to the subclavian artery Lower trunk passes over 1st rib posterior to the subclavian artery Divisions Apex of axilla Cords Related to axillary artery

Answer 1618

The ureter is not related to the round ligament of the uterus, it is related to the broad ligament and is within 1.5cm of the supravaginal part of the cervix. Ureter 25-35 cm long Muscular tube lined by transitional epithelium Surrounded by thick muscular coat. Becomes 3 muscular layers as it crosses the bony pelvis Retroperitoneal structure overlying transverse processes L2-L5 Lies anterior to bifurcation of iliac vessels Blood supply is segmental; renal artery, aortic branches, gonadal branches, common iliac and internal iliac Lies beneath the uterine artery

Answer 1619

Temporal lesions cause a contralateral superior quadranopia. Think temporal area is at the top of the head i.e. superior quadranopia. Another useful mnemonic is: PITS: Parietal Inferior, Temporal superior quadratinopia Visual field defects left homonymous hemianopia means visual field defect to the left, i.e. Lesion of right optic tract homonymous quadrantanopias: PITS (Parietal-Inferior, Temporal-Superior) incongruous defects = optic tract lesion; congruous defects = optic radiation lesion or occipital cortex Homonymous hemianopia Incongruous defects: lesion of optic tract Congruous defects: lesion of optic radiation or occipital cortex Macula sparing: lesion of occipital cortex Homonymous quadrantanopias Superior: lesion of temporal lobe Inferior: lesion of parietal lobe Mnemonic = PITS (Parietal-Inferior, Temporal-Superior) Bitemporal hemianopia Lesion of optic chiasm Upper quadrant defect > lower quadrant defect = inferior chiasmal compression, commonly a pituitary tumour Lower quadrant defect > upper quadrant defect = superior chiasmal compression, commonly a craniopharyngioma

Answer 1620

The glossopharyngeal nerve supplies general sensation to the posterior third of the tongue and contributes to the gag reflex. Cranial nerves Cranial nerve lesions Olfactory nerve May be injured in basal skull fractures or involved in frontal lobe tumour extension. Loss of olfactory nerve function in relation to major CNS pathology is seldom an isolated event and thus it is poor localiser of CNS pathology. Optic nerve Problems with visual acuity may result from intra ocular disorders. Problems with the blood supply such as amaurosis fugax may produce temporary visual distortion. More important surgically is the pupillary response to light. The pupillary size may be altered in a number of disorders. Nerves involved in the resizing of the pupil connect to the pretectal nucleus of the high midbrain, bypassing the lateral geniculate nucleus and the primary visual cortex. From the pretectal nucleus neurones pass to the Edinger - Westphal nucleus, motor axons from here pass along with the oculomotor nerve. They synapse with ciliary ganglion neurones; the parasympathetic axons from this then innervate the iris and produce miosis. The miotic pupil is seen in disorders such as Horner's syndrome or opiate overdose. Mydriasis is the dilatation of the pupil in response to disease, trauma, drugs (or the dark!). It is pathological when light fails to induce miosis. The radial muscle is innervated by the sympathetic nervous system. Because the parasympathetic fibres travel with the oculomotor nerve they will be damaged by lesions affecting this nerve (e.g. cranial trauma). The response to light shone in one eye is usually a constriction of both pupils. This indicates intact direct and consensual light reflexes. When the optic nerve has an afferent defect the light shining on the affected eye will produce a diminished pupillary response in both eyes. Whereas light shone on the unaffected eye will produce a normal pupillary response in both eyes. This is referred to as the Marcus Gunn pupil and is seen in conditions such as optic neuritis. In a total CN II lesion shining the light in the affected eye will produce no response. Oculomotor nerve The pupillary effects are described above. In addition it supplies all ocular muscles apart from lateral rectus and superior oblique. Thus the affected eye will be deviated inferolaterally. Levator palpebrae superioris may also be impaired resulting in impaired ability to open the eye. Trochlear nerve The eye will not be able to look down. Trigeminal nerve Largest cranial nerve. Exits the brainstem at the pons. Branches are ophthalmic, maxillary and mandibular. Only the mandibular branch has both sensory and motor fibres. Branches converge to form the trigeminal ganglion (located in Meckels cave). It supplies the muscles of mastication and also tensor veli palatine, mylohyoid, anterior belly of digastric and tensor tympani. The detailed descriptions of the various sensory functions are described in other areas of the website. The corneal reflex is important and is elicited by applying a small tip of cotton wool to the cornea, a reflex blink should occur if it is intact. It is mediated by: the naso ciliary branch of the ophthalmic branch of the trigeminal (sensory component) and the facial nerve producing the motor response. Lesions of the afferent arc will produce bilateral absent blink and lesions of the efferent arc will result in a unilateral absent blink. Abducens nerve The affected eye will have a deficit of abduction. This cranial nerve exits the brainstem between the pons and medulla. It thus has a relatively long intra cranial course which renders it susceptible to damage in raised intra cranial pressure. Facial nerve Emerges from brainstem between pons and medulla. It controls muscles of facial expression and taste from the anterior 2/3 of the tongue. The nerve passes into the petrous temporal bone and into the internal auditory meatus. It then passes through the facial canal and exits at the stylomastoid foramen. It passes through the parotid gland and divides at this point. It does not innervate the parotid gland. Its divisions are considered in other parts of the website. Its motor fibres innervate orbicularis oculi to produce the efferent arm of the corneal reflex. In surgical practice it may be injured during parotid gland surgery or invaded by malignancies of the gland and a lower motor neurone on the ipsilateral side will result. Vestibulo-cochlear nerve Exits from the pons and then passes through the internal auditory meatus. It is implicated in sensorineural hearing loss. Individuals with sensorineural hearing loss will localise the sound in webers test to the normal ear. Rinnes test will be reduced on the affected side but should still work. These two tests will distinguish sensorineural hearing loss from conductive deafness. In the latter condition webers test will localise to the affected ear and Rinnes test will be impaired on the affected side. Surgical lesions affecting this nerve include CNS tumours and basal skull fractures. It may also be damaged by the administration of ototoxic drugs (of which gentamicin is the most commonly used in surgical practice). Glossopharyngeal nerve Exits the pons just above the vagus. Receives sensory fibres from posterior 1/3 tongue, tonsils, pharynx and middle ear (otalgia may occur following tonsillectomy). It receives visceral afferents from the carotid bodies. It supplies parasympathetic fibres to the parotid gland via the otic ganglion and motor function to stylopharyngeaus muscle. The sensory function of the nerve is tested using the gag reflex. Vagus nerve Leaves the medulla between the olivary nucleus and the inferior cerebellar peduncle. Passes through the jugular foramen and into the carotid sheath. Details of the functions of the vagus nerve are covered in the website under relevant organ sub headings. Accessory nerve Exists from the caudal aspect of the brainstem (multiple branches) supplies trapezius and sternocleidomastoid muscles. The distal portion of this nerve is most prone to injury during surgical procedures. Hypoglossal nerve Emerges from the medulla at the preolivary sulcus, passes through the hypoglossal canal. It lies on the carotid sheath and passes deep to the posterior belly of digastric to supply muscles of the tongue (except palatoglossus). Its location near the carotid sheath makes it vulnerable during carotid endarterectomy surgery and damage will produce ipsilateral defect in muscle function.

Answer 1621

In lower motor neuron lesions everything is reduced The main purpose of this question is to differentiate the features of an UMN lesion and a LMN lesion. The features of a LMN lesion include: Flaccid paralysis of muscles supplied Atrophy of muscles supplied. Loss of reflexes of muscles supplied. Muscles fasciculation For lesions below L1 LMN signs will occur. Hence in an L3 lesion, there will be loss of the patella reflex but there will be no extensor plantar reflex. Spinal cord - Located in a canal within the vertebral column that affords it structural support. Rostrally it continues to the medulla oblongata of the brain and caudally it tapers at a level corresponding to the L1-2 interspace (in the adult), a central structure, the filum terminale anchors the cord to the first coccygeal vertebra. The spinal cord is characterised by cervico-lumbar enlargements and these, broadly speaking, are the sites which correspond to the brachial and lumbar plexuses respectively. There are some key points to note when considering the surgical anatomy of the spinal cord: * During foetal growth the spinal cord becomes shorter than the spinal canal, hence the adult site of cord termination at the L1-2 level. * Due to growth of the vertebral column the spine segmental levels may not always correspond to bony landmarks as they do in the cervical spine. * The spinal cord is incompletely divided into two symmetrical halves by a dorsal median sulcus and ventral median fissure. Grey matter surrounds a central canal that is continuous rostrally with the ventricular system of the CNS. * The grey matter is sub divided cytoarchitecturally into Rexeds laminae. * Afferent fibres entering through the dorsal roots usually terminate near their point of entry but may travel for varying distances in Lissauers tract. In this way they may establish synaptic connections over several levels * At the tip of the dorsal horn are afferents associated with nociceptive stimuli. The ventral horn contains neurones that innervate skeletal muscle. The key point to remember when revising CNS anatomy is to keep a clinical perspective in mind. So it is worth classifying the ways in which the spinal cord may become injured. These include: Trauma either direct or as a result of disc protrusion Neoplasia either by direct invasion (rare) or as a result of pathological vertebral fracture Inflammatory diseases such as Rheumatoid disease, or OA (formation of osteophytes compressing nerve roots etc. Vascular either as a result of stroke (rare in cord) or as complication of aortic dissection Infection historically diseases such as TB, epidural abscesses. The anatomy of the cord will, to an extent dictate the clinical presentation. Some points/ conditions to remember: Brown- Sequard syndrome-Hemisection of the cord producing ipsilateral loss of proprioception and upper motor neurone signs, plus contralateral loss of pain and temperature sensation. The explanation of this is that the fibres decussate at different levels. Lesions below L1 will tend to present with lower motor neurone signs

Answer 1622

Non therapeutic irradiation of the neck is most closely linked to papillary gland cancer. Thyroid gland disorders-cancer Thyroid cancer is a relatively rare condition and overall will comprise approximately 1-2% of all solid tumours in a 1 year period. They are classified as being papillary, follicular, anaplastic, lymphoma and sarcomatous. Presenting features Typically presents as a discrete nodule or mass Lymph node or haematogenous metastasis may be present Locally advanced disease may invade/ compress adjacent structures with symptoms of dysphagia, dyspnoea or speech changes arising from nerve involvement Key points in the history Pattern of symptom onset Any association with pain (cancers are usually painless) Patients age (cancers most common in those aged >60 years) History of radiation exposure is significant as this increases the risk Family history of endocrine disease (MEN I/II) Examination Adequate exposure of the neck Assess peripheral stigmata of thyroid status (most cancers occur in euthyroid patients) Any overt stigmata of MEN Is the mass visible? Palpate the patient's neck stood behind them Palpate the mass whilst asking the patient to swallow to determine its relationship to the thyroid Examine carefully for palpable neck nodes Attempts to elicit Pembertons sign by having the patient elevate their arms may be useful in establishing the presence of a sub sternal goitre Diagnosis In all cases a USS must be performed Where a lesion is identified an FNAC is the usual first line management FNAC cannot accurately diagnose follicular lesions or lymphoma Staging is with chest x-ray and sometimes bone scans. Where an adverse prognosis is suspected CT scanning is usually performed. Lesions Lesion Common features Follicular adenoma Usually present as a solitary thyroid nodule Malignancy can only be excluded on formal histological assessment Papillary carcinoma Usually contain a mixture of papillary and colloidal filled follicles Histologically tumour has papillary projections and pale empty nuclei Seldom encapsulated Lymph node metastasis predominate Haematogenous metastasis rare Account for 60% of thyroid cancers Follicular carcinoma May appear macroscopically encapsulated, microscopically capsular invasion is seen. Without this finding the lesion is a follicular adenoma. Vascular invasion predominates Multifocal disease rare Account for 20% of all thyroid cancers Anaplastic carcinoma Most common in elderly females Local invasion is a common feature Account for 10% of thyroid cancers Treatment is by resection where possible, palliation may be achieved through isthmusectomy and radiotherapy. Chemotherapy is ineffective. Medullary carcinoma Tumours of the parafollicular cells (C Cells) C cells derived from neural crest and not thyroid tissue Serum calcitonin levels often raised Familial genetic disease accounts for up to 20% cases Both lymphatic and haematogenous metastasis are recognised, nodal disease is associated with a very poor prognosis. Management Lesion Usual management Lymphoma Chemotherapy Anaplastic cancer Local debulking surgery, palliative radiotherapy Papillary thyroid cancer Hemithyroidectomy (T1 disease) or total thyroidectomy and central compartmental nodal dissection (T2 or greater) Follicular thyroid cancer Total thyroidectomy Follicular adenoma Hemithyroidectomy (the diagnosis is based on resected tissue analysis) Medullary thyroid cancer Total thyroidectomy

Answer 1623

Isolated fracture of the radius alone can occur but is rare. Always check for associated injury. Eponymous fractures Colles' fracture (dinner fork deformity) Fall onto extended outstretched hand Classical Colles' fractures have the following 3 features: 1. Transverse fracture of the radius 2. 1 inch proximal to the radio-carpal joint 3. Dorsal displacement and angulation Smith's fracture (reverse Colles' fracture) Volar angulation of distal radius fragment (Garden spade deformity) Caused by falling backwards onto the palm of an outstretched hand or falling with wrists flexed Bennett's fracture Intra-articular fracture of the first carpometacarpal joint Impact on flexed metacarpal, caused by fist fights X-ray: triangular fragment at ulnar base of metacarpal Monteggia's fracture Dislocation of the proximal radioulnar joint in association with an ulna fracture Fall on outstretched hand with forced pronation Needs prompt diagnosis to avoid disability Galeazzi fracture Radial shaft fracture with associated dislocation of the distal radioulnar joint Direct blow Pott's fracture Bimalleolar ankle fracture Forced foot eversion Barton's fracture Distal radius fracture (Colles'/Smith's) with associated radiocarpal dislocation Fall onto extended and pronated wrist Involvement of the joint is a defining feature Holstein Lewis Fracture A HolsteinLewis fracture is a fracture of the distal third of the humerus resulting in entrapment of the radial nerve. The radial nerve is one of the major nerves of the upper limb. It innervates all of the muscles in the extensor compartments of the arm. Conservative treatment includes reduction and use of a functional brace Vascular injury may require open surgery

Answer 1624

Trauma is a common precipitant of pyogenic granuloma and contact bleeding and ulceration are common. Skin disorders in surgery- malignancy and related lesions Non melanoma skin cancer (BCC and SCC) are some of the commonest types of human malignancy. Up to 80% of these are BCC's with approximately 20% comprising SCC's. The incidence of NMSC's increases with age and whilst there is a female preponderance in those under 40 years of age, in latter life the sex incidence is roughly equal. The vast majority of NMSC's are related to UV light exposure. For SCC's the major pattern is in chronic long term exposure. For BCC's, the pattern of sporadic exposure with episodes of burning is more important. Organ transplant recipients have a markedly increased incidence of SCC, risk factors include length of immunosuppression, ethnic origin and associated sunlight exposure. Human papilloma virus DNA is found in the majority of transplant recipient SCC's. In addition to this increased risk, transplant recipients are also more likely to develop locoregional recurrences following treatment. Actinic keratosis and SCC Actinic keratosis is viewed as a premalignant lesion because there are atypical keratinocytes present in the epidermis. In a person with 7 actinic keratosis the risks of subsequent SCC is of the order of 10% at 10 years. The primary lesion is a rough erythematous papule with a white to yellow scale. Lesions are typically clustered at sites of chronic sun exposure. Squamous cell carcinoma in situ Also known as Bowens disease the commonest presentation of in situ SCC is with an erythematous scaling patch or elevated plaque arising on sun exposed skin in an elderly patient. Lesions may arise de novo or from pre-existing actinic keratosis. Pathologically there is full thickness atypia of dermal keratinocytes over a broad zone. Nuclear pleomorphism, apoptosis and abnormal mitoses are all seen. Invasive SCC The commonest clinical presentation of SCC is with an erythematous keratotic papule or nodule on a background of sun exposure. Ulceration may occur and both exophytic and endophytic areas may be seen. Regional lymphadenopathy may be present. Pathologically there is downward proliferation of malignant cells and invasion of the basement membrane. Poorly differentiated lesions may show perineural invasion and require immunohistochemistry with S100 to distinguish them from melanomas (which stain strongly positive with this marker). Basal cell carcinoma Nodular BCC Commonest variant (60%) Raised translucent papule Usually affect the face Large nodular BCC's are locally destructive Superficial BCC Usually appears as superficial erythematous macule affecting the trunk Younger age at presentation (mean 57) May show areas of spontaneous regression Horizontal growth pattern predominates High recurrence rate (due to sub clinical lateral spread) Morpheaform BCC Macroscopically resembles flat, slightly atrophic lesion or plaque without well defined borders Tumour has sub clinical lateral spread which increases recurrence rates Cystic BCC Often have clear or blue - grey appearance Cystic degeneration may not be clinically obvious and tumour may resemble nodular BCC Basosquamous carcinoma Atypical BCC Basaloid histological BCC features with eosinophillic squamoid features of SCC Biologically more aggressive and are more locally destructive Rare lesion accounts for 1% of all non melanoma skin cancers Metastatic disease may occur in 9-10% of cases and resemble an SCC Keratoacanthoma Dome shaped erythematous lesions that develop over a period of days and grow rapidly. They often contain a central pit of keratin. They then begin to necrose and slough off. They are generally benign lesions although some do view them as precursors of malignancy. They may be treated by curettage and cautery. If there is diagnostic doubt (they can mimic malignancy) then formal excision biopsy is warranted. Pyogenic granuloma These present as friable overgrowths of granulation at sites of minor trauma. They may be ulcerated and bleeding on contact is common. They may be treated with curretage and cautery, formal excision may be used if there is diagnostic doubt.

Answer 1625

Transitional cell carcinoma of the bladder may be treated with intravesical BCG therapy. Haematuria Causes of haematuria Trauma Injury to renal tract Renal trauma commonly due to blunt injury (others penetrating injuries) Ureter trauma rare: iatrogenic Bladder trauma: due to RTA or pelvic fractures Infection Remember TB Malignancy Renal cell carcinoma (remember paraneoplastic syndromes): painful or painless Urothelial malignancies: 90% are transitional cell carcinoma, can occur anywhere along the urinary tract. Painless haematuria. Squamous cell carcinoma and adenocarcinoma: rare bladder tumours Prostate cancer Penile cancers: SCC Renal disease Glomerulonephritis Stones Microscopic haematuria common Structural abnormalities Benign prostatic hyperplasia (BPH) causes haematuria due to hypervascularity of the prostate gland Cystic renal lesions e.g. polycystic kidney disease Vascular malformations Renal vein thrombosis due to renal cell carcinoma Coagulopathy Causes bleeding of underlying lesions Drugs Cause tubular necrosis or interstitial nephritis: aminoglycosides, chemotherapy Interstitial nephritis: penicillin, sulphonamides, and NSAIDs Anticoagulants Benign Exercise Gynaecological Endometriosis: flank pain, dysuria, and haematuria that is cyclical Iatrogenic Catheterisation Radiotherapy; cystitis, severe haemorrhage, bladder necrosis Pseudohaematuria For example following consumption of beetroot References Http://bestpractice.bmj.com/best-practice/monograph/316/overview/aetiology.html

Answer 1626

The others are all supplied by the recurrent laryngeal nerve. Larynx The larynx lies in the anterior part of the neck at the levels of C3 to C6 vertebral bodies. The laryngeal skeleton consists of a number of cartilagenous segments. Three of these are paired; arytenoid, corniculate and cuneiform. Three are single; thyroid, cricoid and epiglottic. The cricoid cartilage forms a complete ring (the only one to do so). The laryngeal cavity extends from the laryngeal inlet to the level of the inferior border of the cricoid cartilage. Divisions of the laryngeal cavity Laryngeal vestibule Superior to the vestibular folds Laryngeal ventricle Lies between vestibular folds and superior to the vocal cords Infraglottic cavity Extends from vocal cords to inferior border of the cricoid cartilage The vocal folds (true vocal cords) control sound production. The apex of each fold projects medially into the laryngeal cavity. Each vocal fold includes: Vocal ligament Vocalis muscle (most medial part of thyroarytenoid muscle) The glottis is composed of the vocal folds, processes and rima glottidis. The rima glottidis is the narrowest potential site within the larynx, as the vocal cords may be completely opposed, forming a complete barrier. Muscles of the larynx Muscle Origin Insertion Innervation Action Posterior cricoarytenoid Posterior aspect of lamina of cricoid Muscular process of arytenoid Recurrent Laryngeal Abducts vocal fold Lateral cricoarytenoid Arch of cricoid Muscular process of arytenoid Recurrent laryngeal Adducts vocal fold Thyroarytenoid Posterior aspect of thyroid cartilage Muscular process of arytenoid Recurrent laryngeal Relaxes vocal fold Transverse and oblique arytenoids Arytenoid cartilage Contralateral arytenoid Recurrent laryngeal Closure of intercartilagenous part of the rima glottidis Vocalis Depression between lamina of thyroid cartilage Vocal ligament and vocal process of arytenoid cartilage Recurrent laryngeal Relaxes posterior vocal ligament, tenses anterior part Cricothyroid Anterolateral part of cricoid Inferior margin and horn of thyroid cartilage External laryngeal Tenses vocal fold Blood supply Arterial supply is via the laryngeal arteries, branches of the superior and inferior thyroid arteries. The superior laryngeal artery is closely related to the internal laryngeal nerve. The inferior laryngeal artery is related to the inferior laryngeal nerve. Venous drainage is via superior and inferior laryngeal veins, the former draining into the superior thyroid vein and the latter draining into the middle thyroid vein, or thyroid venous plexus. Lymphatic drainage The vocal cords have no lymphatic drainage and this site acts as a lymphatic watershed. Supraglottic part Upper deep cervical nodes Subglottic part Prelaryngeal and pretracheal nodes and inferior deep cervical nodes The aryepiglottic fold and vestibular folds have a dense plexus of lymphatics associated with them and malignancies at these sites have a greater propensity for nodal metastasis.

Answer 1627

Osteoclastoma has a characteristic appearance on x-ray with multiple lytic and lucent areas (Soap bubble) appearances. Pathological fractures may occur. The disease is usually indolent. Bone tumours Benign bone tumours These are relatively common and typically occur in the young. Most will cease growth once skeletal maturity is attained. A key aspect to managing benign bone tumours lies in the exclusion of a malignant bone tumour. Plain films, CT, MRI and sometimes a bone biopsy may be required. Benign tumours Tumour Features Osteoid osteoma M>F Commonest between 10 and 25 years Severe pain that responds to NSAIDS Femur and tibia usually affected Lesion affects cortex and radiologically consists of a lucent centre surrounded by reactive sclerosis Usually smaller than 1cm Chondroma Common benign tumour Endochondroma are central lesions that may cause cortical thinning Ecchondroma project beyond the cortex May cause pathological fracture Rarely found in large bones Osteochondroma One of the commonest benign bone tumours Usually occurs on the surface of a metaphysis (usually femur, proximal humerus or tibia) Pedunculated lesion arising from metaphysis Long standing lesions Do not grow once skeletal maturity reached Bone cyst Commonest in adolescent boys Occur in proximal femur and humerus May result in pathological fracture Does not affect growth plate On imaging appears as ovoid radiolucent area with surrounding cortical thinning Giant cell tumour of bone These lesions sit between benign and malignant. Most are benign. They are relatively rare. They consist of multinucleated giant cells (osteoclast like). Malignancy in these lesions is rare and is of the order of 2%. They account for 20% of benign bone tumours. The lesions may present as an enlarging mass, with pain or pathological fracture. On imaging, these lesions have an epiphyseal location and have a characteristic 'soap bubble' appearance. They do not normally demonstrate sclerosis and have a sharply defined border. Histologically, they demonstrate multinucleated giant cells. Treatment is challenging since these lesions are locally aggressive and have a high rate of local recurrence following excision. Malignant bone tumours The commonest malignant bone tumour is bone metastasis from another solid organ malignancy. Metastatic lesions to bone are significantly more common than primary bone tumours which are extremely rare. Osteosarcoma This is the most common form of primary bone tumour. It typically affects males in their second decade. They typically present as a painful expanding mass affecting a long bone such as the femur, in close proximity to a joint. Imaging demonstrates a lesion with mixed sclerotic and lucent zones in the metaphysis bone formation within the tumour is often visible. All patients will be fully staged at presentation with CT, MRI and often PET scanning. There is a high rate of metastasis to the lungs and most patients will receive chemotherapy. Surgical excision is the main treatment. Ewings sarcoma Ewings sarcomas typically affect long bones and typically occurs during the first two decades of life. They are complex tumours and have overlap with primitive neuroectodermal tumours. They have a predilection for the lower extremity. They typically present as a painful swelling affecting a long bone. Inflammatory markers such as the ESR are sometimes raised and this is associated with a poorer prognosis. On plain films, the tumour shows evidence of bone destruction with a periosteal reaction (onion skin) appearance. As the condition progresses the periosteal findings can change as the tumour invades the periosteum. Treatment is with excisional surgery and chemotherapy. Secondary malignant tumours of bone Metastatic bone tumours may be described as blastic, lytic or mixed. Osteoblastic metastatic disease has the lowest risk of spontaneous fracture when compared to osteolytic lesions of a similar size. Lesions affecting the peritrochanteric region are most prone to spontaneous fracture (because of loading forces at that site). The factors are incorporated into the Mirel Scoring system to stratify the risk of spontaneous fracture for bone metastasis of varying types. Mirel Scoring system Score points Site Radiographic appearance Width of bone involved Pain 1 Upper extremity Blastic Less than 1/3 Mild 2 Lower extremity Mixed 1/3 to 2/3 Moderate 3 Peritrochanteric Lytic More than 2/3 Aggravated by function Depending upon the score the treatment should be as follows: Score Risk of fracture Treatment 9 or greater Impending (33%) Prophylactic fixation 8 Borderline Consider fixation 7 or less Not impending (4%) Non operative management

Answer 1628

This is typical for a benign non functional adenoma. Benign adenomas often have a lipid rich core that is readily identifiable on CT scanning. In addition the nodules are often well circumscribed. Phaeochromocytoma and adrenal lesions Phaeochromocytoma Neuroendocrine tumour of the chromaffin cells of the adrenal medulla. Hypertension and hyperglycaemia are often found. 10% of cases are bilateral. 10% occur in children. 11% are malignant (higher when tumour is located outside the adrenal). 10% will not be hypertensive. Familial cases are usually linked to the Multiple endocrine neoplasia syndromes (considered under its own heading). Most tumours are unilateral (often right sided) and smaller than 10cm. Diagnosis Urine and plasma metanephrine levels. CT and MRI scanning are both used to localise the lesion. Treatment Patients require medical therapy first. An irreversible alpha adrenoreceptor blocker should be given, although minority may prefer reversible blockade(1). Labetolol may be co-administered for cardiac chronotropic control. Isolated beta blockade should not be considered as it will lead to unopposed alpha activity. These patients are often volume depleted and will often require moderate volumes of intra venous normal saline perioperatively. Once medically optimised the phaeochromocytoma should be removed. Most adrenalectomies can now be performed using a laparoscopic approach(2). The adrenals are highly vascular structures and removal can be complicated by catastrophic haemorrhage in the hands of the inexperienced. This is particularly true of right sided resections where the IVC is perilously close. Should the IVC be damaged a laparotomy will be necessary and the defect enclosed within a Satinsky style vascular clamp and the defect closed with prolene sutures. Attempting to interfere with the IVC using any instruments other than vascular clamps will result in vessel trauma and make a bad situation much worse. Incidental adrenal lesions Adrenal lesions may be identified on CT scanning performed for other reasons(3). Factors suggesting benign disease on CT include(4): Size less than 3cm Homogeneous texture Lipid rich tissue Thin wall to lesion All patients with incidental lesions should be managed jointly with an endocrinologist and full work up as described above. Patients with functioning lesions or those with adverse radiological features (Particularly size >3cm) should proceed to surgery. References 1. Weingarten TN, Cata JP, O'Hara JF, Prybilla DJ, Pike TL, Thompson GB, et al. Comparison of two preoperative medical management strategies for laparoscopic resection of pheochromocytoma. Urology. 2010 Aug;76(2):508 e6-11. 2. Nguyen PH, Keller JE, Novitsky YW, Heniford BT, Kercher KW. Laparoscopic approach to adrenalectomy: review of perioperative outcomes in a single center. Am Surg. 2011 May;77(5):592-6. 3. Ng VW, Ma RC, So WY, Choi KC, Kong AP, Cockram CS, et al. Evaluation of functional and malignant adrenal incidentalomas. Arch Intern Med. 2010 Dec 13;170(22):2017-20. 4. Muth A, Hammarstedt L, Hellstrom M, Sigurjonsdottir HA, Almqvist E, Wangberg B. Cohort study of patients with adrenal lesions discovered incidentally. Br J Surg. 2011 May 27.

Answer 1629

In this scenario it must be assumed that the bile duct has been damaged. In most cases an ERCP is the most appropriate investigation. This can also allow the passage of a stent if this is deemed to be safe and sensible. Other imaging modalities will add little to overall management and simply add delay. Complications following cholecystectomy Complications following cholecystectomy Open conversion One of the largest series, published by Shea in 1996 with a total of more than 70,000 cholecystectomies analysed by pooled studies tends to list most complications as having an incidence of <1%. This includes open conversion which they identified as occurring in less than 1%. One of the interesting points raised by this data is that it covers an early period in laparoscopy and there is highly likely to be an element of selection bias in the cases put forward for laparoscopy. Indeed, some surgeons have noted their own institutions conversion rates increase (in this case 7%) as they take on increasingly complex cases. Bile leaks Where these occur they are usually the result of leakage from biliary radicles or cystic stump leaks. Many patients with a cystic stump leak can be managed with ERCP , sphincterotomy and stent. They are not common complications and have an incidence of around 1%. Bile duct injury Cholecystectomy remains the commonest cause of bile duct injury. Reported incidences range from 0.3-0.7%. The main reason is that biliary anatomy is not appreciated. Where they occur, the definitive management is reconstruction. If the operating surgeon does not regularly practise this type of surgery then the area should be drained and the patient transferred to an HPB unit.

Answer 1630

The combination of long history, offensive discharge and hearing loss is strongly suggestive of cholesteatoma. Disorders affecting the ear Otitis externa Variant Cause Features Treatment Acute otitis externa Boil in external auditory meatus Acute pain on moving the pinna Conductive hearing loss if lesion is large When rupture occurs pus will flow from ear Ear packs may be used Topical antibiotics Operative debridement may be needed in severe cases Chronic otitis externa Chronic combined infection in the external auditory meatus usually combined staphylococcal and fungal infection Chronic discharge from affected ear, hearing loss and severe pain rare Cleansing of the external ear and treatment with antifungal and antibacterial ear drops Otitis media Variant Cause Features Treatment Acute suppurative otitis media Viral induced middle ear effusions secondary to eustacian tube dysfunction Most common in children and rare in adults May present with symptoms elsewhere (e.g. vomiting) in children Severe pain and sometimes fever May present with discharge if tympanic rupture occurs Antibiotics (usually amoxycillin) Chronic suppurative otitis media May occur with or without cholesteatoma Those without cholesteatoma have a perforation of the pars tensa Those with cholesteatoma have a perforation of the pars flaccida Those without cholesteatoma may complain of intermittent discharge (non offensive) Those with cholesteatoma have impaired hearing and foul smelling discharge Simple pars tensa perforations may be managed non operatively or a myringoplasty considered if symptoms troublesome. Pars flaccida perforations will usually require a modified radical mastoidectomy Otosclerosis Progressive conductive deafness Secondary to fixation of the stapes in the oval window Treatment is with stapedectomy and insertion of a prosthesis Acoustic neuroma Symptoms of gradually progressive unilateral perceptive deafness and tinnitus Involvement of the vestibular nerve may cause vertigo Extension to involve the facial nerve may cause weakness and then paralysis. Pre auricular sinus Common congenital condition in which an epithelial defect forms around the external ear Small sinuses require no treatment Deeper sinuses may become blocked and develop episodes of infection, they may be closely related to the facial nerve and are challenging to excise

Answer 1631

Dermatofibromas may be pigmented and are often larger than they appear. They frequently occur at sites of previous trauma. Benign skin diseases Seborrhoeic keratosis Most commonly arise in patients over the age of 50 years, often idiopathic Equal sex incidence and prevalence Usually multiple lesions over face and trunk Flat, raised, filiform and pedunculated subtypes are recognised Variable colours and surface may have greasy scale overlying it Treatment options consist of leaving alone or simple shave excision Melanocytic naevi Congenital melanocytic naevi Typically appear at, or soon after, birth Usually greater than 1cm diameter Increased risk of malignant transformation (increased risk greatest for large lesions) Junctional melanocytic naevi Circular macules May have heterogeneous colour even within same lesion Most naevi of the palms, soles and mucous membranes are of this type Compound naevi Domed pigmented nodules up to 1cm in diameter Arise from junctional naevi, usually have uniform colour and are smooth Spitz naevus Usually develop over a few months in children May be pink or red in colour, most common on face and legs May grow up to 1cm and growth can be rapid, this usually results in excision Atypical naevus syndrome Atypical melanocytic naevi that may be autosomally dominantly inherited Some individuals are at increased risk of melanoma (usually have mutations of CDKN2A gene) Many people with atypical naevus syndrome AND a parent sibling with melanoma will develop melanoma Epidermoid cysts Common and affect face and trunk They have a central punctum, they may contain small quantities of sebum The cyst lining is either normal epidermis (epidermoid cyst) or outer root sheath of hair follicle (pilar cyst) Dermatofibroma Solitary dermal nodules Usually affect extremities of young adults Lesions feel larger than they appear visually Histologically they consist of proliferating fibroblasts merging with sparsely cellular dermal tissues Painful skin lesions Eccrine spiradenoma Neuroma Glomus tumour Leiomyoma Angiolipoma Neurofibroma (rarely painful) and dermatofibroma (rarely painful)

Answer 1632

This woman has a good prognosis. In younger women, DXT following breast conserving surgery is still the standard of care. In some older patients, it may be omitted. Breast cancer management - Surgery is performed in most patients suffering from breast cancer. Chemotherapy may be used to downstage tumours and allow breast conserving surgery. Hormonal therapy may also be used for the same purposes. Radiotherapy is given to most patients who have undergone breast conserving surgery (some older patients receiving hormone treatment and who have small low grade tumours may safely avoid DXT. Therapeutic mammoplasty is an option for some patients but requires symmetrizing surgery in most cases. Patients who have undergone mastectomy may be offered a reconstructive procedure either in conjunction with their primary resection or as a staged procedure at a later date. Surgical options Mastectomy vs Wide local excision Mastectomy Wide Local Excision Multifocal tumour Solitary lesion Central tumour Peripheral tumour Large lesion in small breast Small lesion in large breast DCIS >4cm DCIS <4cm Patient Choice Patient choice Central lesions may be managed using breast conserving surgery, where an acceptable cosmetic result may be obtained, this is rarely the case in small breasts Axillary disease As a minimum, all patients with invasive breast cancer should have their axilla staged. In those who do not have overt evidence of axillary nodal involvement this can be undertaken using sentinel lymph node biopsy. Patients with a positive sentinel lymph node biopsy or who have imaging and cytological or histological evidence of axillary nodal metastasis should undergo axillary node clearance or axillary irradiation. Axillary node clearance is associated with the development of lymphoedema, increased risk of cellulitis and frozen shoulder.

Answer 1633

Aggressive fibromatosis Aggressive fibromatosis is a disorder consisting of desmoid tumours, which behave in a locally aggressive manner. Desmoid tumours may be identified in both abdominal and extra-abdominal locations. Metastatic disease is rare. The main risk factor (for abdominal desmoids) is having APC variant of familial adenomatous polyposis coli. Most cases are sporadic. Treatment is by surgical excision.

Answer 1634

The appendicular artery is a branch of the ileocolic artery. Appendix Location: Base of caecum. Up to 10cm long. Mainly lymphoid tissue (Hence mesenteric adenitis may mimic appendicitis). Caecal taenia coli converge at base of appendix and form a longitudinal muscle cover over the appendix. This convergence should facilitate its identification at surgery if it is retrocaecal and difficult to find (which it can be when people start doing appendicectomies!) Arterial supply: Appendicular artery (branch of the ileocolic). It is intra peritoneal. McBurney's point 1/3 of the way along a line drawn from the Anterior Superior Iliac Spine to the Umbilicus 6 Positions: Retrocaecal 74% Pelvic 21% Postileal Subcaecal Paracaecal Preileal

Answer 1635

This is the best local anaesthetic for this. Bupivacaine may cause cardiotoxicity and should be avoided. Local anaesthetic agents Lidocaine An amide Local anaesthetic and a less commonly used antiarrhythmic (affects Na channels in the axon) Hepatic metabolism, protein bound, renally excreted Toxicity: due to IV or excess administration. Increased risk if liver dysfunction or low protein states. Note acidosis causes lidocaine to detach from protein binding. Drug interactions: Beta blockers, ciprofloxacin, phenytoin Features of toxicity: Initial CNS over activity then depression as lidocaine initially blocks inhibitory pathways then blocks both inhibitory and activating pathways. Cardiac arrhythmias. Increased doses may be used when combined with adrenaline to limit systemic absorption. Cocaine Pure cocaine is a salt, usually cocaine hydrochloride. It is supplied for local anaesthetic purposes as a paste. It is supplied for clinical use in concentrations of 4 and 10%. It may be applied topically to the nasal mucosa. It has a rapid onset of action and has the additional advantage of causing marked vasoconstriction. It is lipophillic and will readily cross the blood brain barrier. Its systemic effects also include cardiac arrhythmias and tachycardia. Apart from its limited use in ENT surgery it is otherwise used rarely in mainstream surgical practice. Bupivacaine Bupivacaine binds to the intracellular portion of sodium channels and blocks sodium influx into nerve cells, which prevents depolarization. It has a much longer duration of action than lignocaine and this is of use in that it may be used for topical wound infiltration at the conclusion of surgical procedures with long duration analgesic effect. It is cardiotoxic and is therefore contra indicated in regional blockage in case the tourniquet fails. Levobupivacaine (Chirocaine) is less cardiotoxic and causes less vasodilation. Prilocaine Similar mechanism of action to other local anaesthetic agents. However, it is far less cardiotoxic and is therefore the agent of choice for intravenous regional anaesthesia e.g. Biers Block. All local anaesthetic agents dissociate in tissues and this contributes to their therapeutic effect. The dissociation constant shifts in tissues that are acidic e.g. where an abscess is present, and this reduces the efficacy. Doses of local anaesthetics Agent Dose plain Dose with adrenaline Lignocaine 3mg/Kg 7mg/Kg Bupivacaine 2mg/Kg 2mg/Kg Prilocaine 6mg/Kg 9mg/Kg These are a guide only as actual doses depend on site of administration, tissue vascularity and co-morbidities. Maximum total local anaesthetic doses Lignocaine 1% plain - 3mg/ Kg - 200mg (20ml) Lignocaine 1% with 1 in 200,000 adrenaline - 7mg/Kg - 500mg (50ml) Bupivacaine 0.5% - 2mg/kg- 150mg (30ml) Maximum doses are based on ideal body weight Effects of adrenaline Adrenaline may be added to local anaesthetic drugs. It prolongs the duration of action at the site of injection and permits usage of higher doses (see above). It is contra indicated in patients taking MAOI's or tricyclic antidepressants. The toxicity of bupivacaine is related to protein binding and addition of adrenaline to this drug does not permit increases in the total dose of bupivacaine, in contrast to the situation with lignocaine. References An excellent review is provided by: French J and Sharp L. Local Anaesthetics. Ann R Coll Surg Engl 2012; 94: 76-80.

Answer 1636

A diagnosis of stress incontinence is obvious from the history, therefore there is no need for a bladder diary or urodynamic studies. Pelvic floor exercises would be the first line management. Urinary incontinence Involuntary passage of urine. Most cases are female (80%). It has a prevalence of 11% in those aged greater than 65 years. The commonest variants include: Stress urinary incontinence (50%) Urge incontinence (15%) Mixed (35%) Males Males may also suffer from incontinence although it is a much rarer condition in men. A number of anatomical factors contribute to this. Males have 2 powerful sphincters; one at the bladder neck and the other in the urethra. Damage to the bladder neck mechanism is a factor in causing retrograde ejaculation following prostatectomy. The short segment of urethra passing through the urogenital diaphragm consists of striated muscle fibres (the external urethral sphincter) and smooth muscle capable of more sustained contraction. It is the latter mechanism that maintains continence following prostatectomy. Females The sphincter complex at the level of bladder neck is poorly developed in females. As a result the external sphincter complex is functionally more important, its composition being similar to that of males. Innervation is via the pudendal nerve and the neuropathy that may accompany obstetric events may compromise this and lead to stress urinary incontinence. Innervation Somatic innervation to the bladder is via the pudendal, hypogastric and pelvic nerves. Autonomic nerves travel in these nerve fibres too. Bladder filling leads to detrusor relaxation (sympathetic) coupled with sphincter contraction. The parasympathetic system causes detrusor contraction and sphincter relaxation. Overall control of micturition is centrally mediated via centres in the Pons. Stress urinary incontinence 50% of cases, especially in females. Damage (often obstetric) to the supporting structures surrounding the bladder may lead to urethral hypermobility. Other cases due to sphincter dysfunction, usually from neurological disorders (e.g. Pudendal neuropathy, multiple sclerosis). Urethral mobility: Pressure not transmitted appropriately to the urethra resulting in involuntary passage of urine during episodes of raised intra-abdominal pressure. Sphincter dysfunction: Sphincter fails to adapt to compress urethra resulting in involuntary passage of urine. When the sphincter completely fails there is often to continuous passage of urine. Urge incontinence In these patients there is sense of urgency followed by incontinence. The detrusor muscle in these patients is unstable and urodynamic investigation will demonstrate overactivity of the detrusor muscle at inappropriate times (e.g. Bladder filling). Urgency may be seen in patients with overt neurological disorders and those without. The pathophysiology is not well understood but poor central and peripheral co-ordination of the events surrounding bladder filling are the main processes. Assessment Careful history and examination including vaginal examination for cystocele. Bladder diary for at least 3 days Consider flow cystometry if unclear symptomatology or surgery considered and diagnosis is unclear. Exclusion of other organic disease (e.g. Stones, UTI, Cancer) Management Conservative measures should be tried first; Stress urinary incontinence or mixed symptoms should undergo 3 months of pelvic floor exercise. Over active bladder should have 6 weeks of bladder retraining. Drug therapy for women with overactive bladder should be offered oxybutynin (or solifenacin if elderly) if conservative measures fail. In women with detrusor instability who fail non operative therapy a trial of sacral neuromodulation may be considered, with conversion to permanent implant if good response. Augmentation cystoplasty is an alternative but will involve long term intermittent self catheterisation. In women with stress urinary incontinence a urethral sling type procedure may be undertaken. Where cystocele is present in association with incontinence it should be repaired particularly if it lies at the introitus. NICE guidelines Initial assessment urinary incontinence should be classified as stress/urge/mixed. At least 3/7 bladder diary if unable to classify easily. Start conservative treatment before urodynamic studies if a diagnosis is obvious from the history Urodynamic studies if plans for surgery. Stress incontinence: Pelvic floor exercises 3/12, if fails consider surgery. Urge incontinence: Bladder training >6/52, if fails for oxybutynin (antimuscarinic drugs) then sacral nerve stimulation. Pelvic floor exercises offered to all women in their 1st pregnancy.

Answer 1637

Delayed passage of meconium is suggestive of Hirschsprung's disease and the investigation of choice is full thickness suction rectal biopsy. The condition is managed with washouts initially. At between 9 and 12 months of age, definitive surgery (usually resection and primary anastomosis) is performed. Paediatric Gastrointestinal disorders Pyloric stenosis M>F 5-10% Family history in parents Projectile non bile stained vomiting at 4-6 weeks of life Diagnosis is made by test feed or USS Treatment: Ramstedt pyloromyotomy (open or laparoscopic) Acute appendicitis Uncommon under 3 years When occurs may present atypically Mesenteric adenitis Central abdominal pain and URTI Conservative management Intussusception Telescoping bowel Proximal to or at the level of, ileocaecal valve 6-9 months age Colicky pain, diarrhoea and vomiting, sausage shaped mass, red jelly stool. Treatment: reduction with air insufflation Malrotation High caecum at the midline Feature in exomphalos, congenital diaphragmatic hernia, intrinsic duodenal atresia May be complicated by development of volvulus, infant with volvulus may have bile stained vomiting Diagnosis is made by upper GI contrast study and USS Treatment is by laparotomy, if volvulus is present (or at high risk of occurring then a ladds procedure is performed Hirschsprung's disease Absence of ganglion cells from myenteric and submucosal plexuses Occurs in 1/5000 births Full thickness rectal biopsy for diagnosis Delayed passage of meconium and abdominal distension Treatment is with rectal washouts initially, thereafter an anorectal pull through procedure Oesophageal atresia Associated with tracheo-oesophageal fistula and polyhydramnios May present with choking and cyanotic spells following aspiration VACTERL associations Meconium ileus Usually delayed passage of meconium and abdominal distension Majority have cystic fibrosis X-Rays may not show a fluid level as the meconium is viscid (depends upon feeding), PR contrast studies may dislodge meconium plugs and be therapeutic Infants who do not respond to PR contrast and NG N-acetyl cysteine will require surgery to remove the plugs Biliary atresia Jaundice > 14 days Increased conjugated bilirubin Urgent Kasai procedure Necrotising enterocolitis Prematurity is the main risk factor Early features include abdominal distension and passage of bloody stools X-Rays may show pneumatosis intestinalis and evidence of free air Increased risk when empirical antibiotics are given to infants beyond 5 days Treatment is with total gut rest and TPN, babies with perforations will require laparotomy

Answer 1638

Infection with enterobius is extremely common. Pruritus is the main symptom, as there is a lack of tissue invasion it is rare for individuals to have any signs of systemic sepsis. Gastro intestinal parasitic infections Common infections Enterobiasis Due to organism Enterobius vermicularis Common cause of pruritus ani Diagnosis usually made by placing scotch tape at the anus, this will trap eggs that can then be viewed microscopically Treatment is with mebendazole Ancylostoma duodenale Hookworms that anchor in proximal small bowel Most infections are asymptomatic although may cause iron deficiency anaemia Larvae may be found in stools left at ambient temperature, otherwise infection is difficult to diagnose Infection occurs as a result of cutaneous penetration, migrates to lungs, coughed up and then swallowed Treatment is with mebendazole Ascariasis Due to infection with roundworm Ascaris lumbricoides Infections begin in gut following ingestion, then penetrate duodenal wall to migrate to lungs, coughed up and swallowed, cycle begins again Diagnosis is made by identification of worm or eggs within faeces Treatment is with mebendazole Strongyloidiasis Due to infection with Strongyloides stercoralis Rare in west Organism is a nematode living in duodenum of host Initial infection is via skin penetration. They then migrate to lungs and are coughed up and swallowed. Then mature in small bowel are excreted and cycle begins again An auto infective cycle is also recognised where larvae will penetrate colonic wall Individuals may be asymptomatic, although they may also have respiratory disease and skin lesions Diagnosis is usually made by stool microscopy In the UK mebendazole is used for treatment Cryptosporidium Protozoal infection Organisms produce cysts which are excreted and thereby cause new infections Symptoms consist of diarrhoea and cramping abdominal pains. Symptoms are worse in immunosuppressed people Cysts may be identified in stools Treatment is with metronidazole Giardiasis Diarrhoeal infection caused by Giardia lamblia (protozoan) Infections occur as a result of ingestion of cysts Symptoms are usually gastrointestinal with abdominal pain, bloating and passage of soft or loose stools Diagnosis is by serology or stool microscopy First line treatment is with metronidazole

Answer 1639

TPN is known to result in derangement of liver function tests. Although, cholestasis may result from TPN, it would be very unusual for gallstones to form and result in the picture above. Blood transfusion reactions typically present earlier and with changes in the haemoglobin and although they may cause hepatitis this is rare nowadays. Total parenteral nutrition Commonly used in nutritionally compromised surgical patients. Bags contain combinations of glucose, lipids and essential electrolytes, the exact composition is determined by the patients nutritional requirements. Although it may be infused peripherally, this may result in thrombophlebitis. Longer term infusions should be administered into a central vein (preferably via a PICC line). Complications are related to sepsis, re-feeding syndromes and hepatic dysfunction.

Answer 1640

Opiates typically affect the medullary respiratory centre to depress respiratory activity. Control of ventilation - Control of ventilation is coordinated by the respiratory centres, chemoreceptors, lung receptors and muscles. Automatic, involuntary control of respiration occurs from the medulla. The respiratory centres control the respiratory rate and the depth of respiration. Respiratory centres Medullary respiratory centre Inspiratory and expiratory neurones. Has ventral group which controls forced voluntary expiration and the dorsal group controls inspiration. Depressed by opiates. Apneustic centre Lower pons Stimulates inspiration - activates and prolongs inhalation Overridden by pneumotaxic control to end inspiration Pneumotaxic centre Upper pons, inhibits inspiration at a certain point. Fine tunes the respiratory rate. Ventillatory variables Levels of pCO2 most important in ventilation control Levels of O2 are less important. Peripheral chemoreceptors: located in the bifurcation of carotid arteries and arch of the aorta. They respond to changes in reduced pO2, increased H+ and increased pCO2 in ARTERIAL BLOOD. Central chemoreceptors: located in the medulla. Respond to increased H+ in BRAIN INTERSTITIAL FLUID to increase ventilation. NB the central receptors are NOT influenced by O2 levels. Lung receptors include: Stretch receptors: respond to lung stretching causing a reduced respiratory rate Irritant receptors: respond to smoke etc causing bronchospasm J (juxtacapillary) receptors

Answer 1641

Features of an addisonian crisis: Hyponatraemia Hyperkalaemia Hypoglycaemia This man is on steroids for polymyalgia rheumatica. Surgery can precipitate acute adrenal deficiency. The diagnosis is further confirmed by the blood results of hyponatraemia, hyperkalaemia and hypoglycaemia. This patient urgently needs hydrocortisone. Addisonian crisis Causes Sepsis or surgery causing an acute exacerbation of chronic insufficiency (Addison's, Hypopituitarism) Adrenal haemorrhage eg Waterhouse-Friderichsen syndrome (fulminant meningococcemia) Steroid withdrawal Management Hydrocortisone 100 mg im or iv 1 litre normal saline infused over 30-60 mins or with dextrose if hypoglycaemic Continue hydrocortisone 6 hourly until the patient is stable. No fludrocortisone is required because high cortisol exerts weak mineralocorticoid action Oral replacement may begin after 24 hours and be reduced to maintenance over 3-4 days

Answer 1642

Urea is not one of the variables considered. Severe infections Sepsis is a multifaceted syndrome which arises as a result of an infective process. Historically, the main focus was on the pro-inflammatory nature of the process, accordingly, 2 of the 4 SIRS criteria were related solely to inflammatory excesses. More modern systems take into account the fact that some of the effects of sepsis are suppressive from an immunological perspective and effects on organ function can be widespread. Sepsis is now defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. This new definition emphasizes the primacy of the non homeostatic host response to infection, the potential lethality that is considerably in excess of a straightforward infection, and the need for urgent recognition. To help identify and categorise patients the Sequential (Sepsis-Related) Organ Failure Assessment Score (SOFA) is increasingly used. The score grades abnormality by organ system and accounts for clinical interventions. However, laboratory variables, namely, PaO2, platelet count, creatinine level, and bilirubin level, are needed for full computation. SOFA Score System Score 0 Score 1 Score 2 Score 3 Score 4 PaO2 /FI O2 >400 <400 <300 <200 <100 Platelets x103 microlitres >150 <150 <100 <50 <20 Bilirubin micro Mol/L 20 20-32 33-101 102-204 >204 Cardiovascular MAP >70mmHg MAP 70mmHg Dopamine <5 or dobutamine (any dose) Dopamine 5.1-15 or epinephrine 0.1 or norepinephrine 0.1 Dopamine >15 or epinephrine >0.1 or norepinephrine >0.1 GCS 15 13-14 10-12 6-9 <6 Creatinine micro mol/L <110 110-170 171-299 300-440 >440 Urine output ml/day >500 >500 >500 <500 <200 A SOFA score of 2 or more reflects an overall mortality risk of approximately 10% in a general hospital population with suspected infection. Even patients presenting with modest dysfunction can deteriorate further, emphasizing the seriousness of this condition and the need for prompt and appropriate intervention, if not already being instituted. The qSOFA score (also known as quickSOFA) is a bedside prompt that may identify patients with suspected infection who are at greater risk for a poor outcome outside the intensive care unit (ICU). It uses three criteria, assigning one point for low blood pressure (SBP<100 mmHg), high respiratory rate (>22 breaths per min), or altered mentation (Glasgow coma scale<15). qSOFA score Respiratory rate 22/min Altered mentation Systolic blood pressure 100 mm Hg Patients with septic shock can be identified with a clinical construct of sepsis with persisting hypotension requiring vasopressors to maintain MAP 65 mm Hg and having a serum lactate level >2 mmol/L (18mg/dL) despite adequate volume resuscitation. With these criteria, hospital mortality is in excess of 40%. Resuscitation goals CVP 8-12mmHg MAP >65mmHg Urine output >0.5ml/kg per hour Superior vena cava oxygen saturation >70% Normal lactate References Singer M, Deutschman C, Seymour C et al. The third international consensus definitions for sepsis and septic shock (Sepsis 3). JAMA 2016; 315(8):801-810.

Answer 1643

Intussusception should be considered in toddlers and infants presenting with screaming attacks. The child often has a history of being unwell for one to three days prior to presentation. The child may pass bloody mucus stool, which is a late sign. Examination of the abdomen is often normal as the sausage mass in the right upper quadrant is difficult to feel. Acute abdominal pain-diagnoses Conditions presenting with acute abdominal pain Condition Features Investigations Management Appendicitis History of migratory pain. Fever. Anorexia. Evidence of right iliac fossa tenderness. Mild pyrexia. Differential white cell count Pregnancy test C-Reactive protein Amylase Urine dipstick testing Appendicectomy Mesenteric adenitis Usually recent upper respiratory tract infection. High fever. Generalised abdominal discomfort- true localised pain and signs are rare. Full blood count- may show slightly raised white cell count Urine dipstick often normal Abdominal ultrasound scan - usually no free fluid Conservative management- appendicectomy if diagnostic doubt Mittelschmerz Only seen in females Mid cycle pain Usually occurs two weeks after last menstrual period Pain usually has a supra-pubic location Usually subsides over a 24-48 hour period. Full blood count- normal Urine dipstick- normal Abdominal and pelvic ultrasound- may show a trace of pelvic free fluid Manage conservatively if doubt or symptoms fail to settle then laparoscopy Fitz-Hugh Curtis syndrome Disseminated infection with Chlamydia. Usually seen in females. Consists of evidence of pelvic inflammatory disease together with peri-hepatic inflammation and subsequent adhesion formation. Abdominal ultrasound scan- may show free fluid High vaginal swabs - may show evidence of sexually transmitted infections Usually medically managed- doxycycline or azithromycin Abdominal aortic aneurysm (ruptured) Sudden onset of abdominal pain radiating to the back in older adults (look for risk factors). Collapse. May be moribund on arrival in casualty, more stable if contained haematoma. Careful clinical assessment may reveal pulsatile mass. Patients who are haemodynamically stable should have a CT scan Unstable patients should undergo immediate surgery (unless it is not in their best interests). Those with evidence of contained leak on CT should undergo immediate surgery Increasing unruptured aneurysmal size is an indication for urgent surgical intervention (that can wait until the next working day) Perforated peptic ulcer Sudden onset of pain (usually epigastric). Often preceding history of upper abdominal pain. Soon develop generalised abdominal pain. On examination may have clinical evidence of peritonitis. Erect CXR may show free air. A CT scan may be indicated where there is diagnostic doubt Laparotomy (laparoscopic surgery for perforated peptic ulcers is both safe and feasible in experienced hands) Intestinal obstruction Colicky abdominal pain and vomiting (the nature of which depends on the level of the obstruction). Abdominal distension and constipation (again depending upon site of obstruction). Features of peritonism may occur where local necrosis of bowel loops is occurring. A plain abdominal film may help with making the diagnosis. A CT scan may be useful where diagnostic uncertainty exists In those with a virgin abdomen a lower and earlier threshold for laparotomy should exist than in those who may have adhesional obstruction Mesenteric infarction Embolic events present with sudden pain and forceful evacuation. Acute on chronic events usually have a longer history and previous weight loss. On examination the pain is typically greater than the physical signs would suggest. Arterial pH and lactate Arterial phase CT scanning is the most sensitive test

Answer 1644

Ventricular tachycardia Ventricular tachycardia (VT)is broad-complex tachycardia originating from a ventricular ectopic focus. It has the potential to precipitate ventricular fibrillation and hence requires urgent treatment. There are two main types of VT: monomorphic VT: most commonly caused by myocardial infarction polymorphic VT: A subtype of polymorphic VT is torsades de pointes which is precipitated by prolongation of the QT interval. The causes of a long QT interval are listed below Causes of a prolonged QT interval Congenital Jervell-Lange-Nielsen syndrome (includes deafness and is due to an abnormal potassium channel) Romano-Ward syndrome (no deafness) Drugs amiodarone, sotalol, class 1a antiarrhythmic drugs tricyclic antidepressants, fluoxetine chloroquine terfenadine erythromycin Other electrolyte: hypocalcaemia, hypokalaemia, hypomagnesaemia acute myocardial infarction myocarditis hypothermia subarachnoid haemorrhage

Answer 1645

During splenectomy the tail of the pancreas may be damaged. The pancreatic duct will then drain into the splenic bed, amylase is the most likely biochemical finding. Glucagon is not secreted into the pancreatic duct. Splenic anatomy The spleen is the largest lymphoid organ in the body. It is an intraperitoneal organ, the peritoneal attachments condense at the hilum where the vessels enter the spleen. Its blood supply is from the splenic artery (derived from the coeliac axis) and the splenic vein (which is joined by the IMV and unites with the SMV). Embryology: derived from mesenchymal tissue Shape: clenched fist Position: below 9th-12th ribs Weight: 75-150g Relations Superiorly- diaphragm Anteriorly- gastric impression Posteriorly- kidney Inferiorly- colon Hilum: tail of pancreas and splenic vessels Forms apex of lesser sac (containing short gastric vessels)

Answer 1646

The pudendal nerve is located in the deep perineal space and then branches to innervate more superficial structures. Urogenital triangle The urogenital triangle is formed by the: Ischiopubic inferior rami Ischial tuberosities A fascial sheet is attached to the sides, forming the inferior fascia of the urogenital diaphragm. It transmits the urethra in males and both the urethra and vagina in females. The membranous urethra lies deep to this structure and is surrounded by the external urethral sphincter. Superficial to the urogenital diaphragm lies the superficial perineal pouch. In males this contains: Bulb of penis Crura of the penis Superficial transverse perineal muscle Posterior scrotal arteries Posterior scrotal nerves In females the internal pudendal artery branches to become the posterior labial arteries in the superficial perineal pouch.

Answer 1647

Whilst she may have an underlying parathyroid lesion, resuscitation should occur first. Initially, this should be with crystalloid. Parathyroid glands and disorders of calcium metabolism Hyperparathyroidism Disease type Hormone profile Clinical features Cause Primary hyperparathyroidism PTH (Elevated) Ca2+ (Elevated) Phosphate (Low) Urine calcium : creatinine clearance ratio > 0.01 May be asymptomatic if mild Recurrent abdominal pain (pancreatitis, renal colic) Changes to emotional or cognitive state Most cases due to solitary adenoma (80%), multifocal disease occurs in 10-15% and parathyroid carcinoma in 1% or less Secondary hyperparathyroidism PTH (Elevated) Ca2+ (Low or normal) Phosphate (Elevated) Vitamin D levels (Low) May have few symptoms Eventually may develop bone disease, osteitis fibrosa cystica and soft tissue calcifications Parathyroid gland hyperplasia occurs as a result of low calcium, almost always in a setting of chronic renal failure Tertiary hyperparathyroidism Ca2+ (Normal or high) PTH (Elevated) Phosphate levels (Decreased or Normal) Vitamin D (Normal or decreased) Alkaline phosphatase (Elevated) Metastatic calcification Bone pain and / or fracture Nephrolithiasis Pancreatitis Occurs as a result of ongoing hyperplasia of the parathyroid glands after correction of underlying renal disorder, hyperplasia of all 4 glands is usually the cause Differential diagnoses It is important to consider the rare but relatively benign condition of benign familial hypocalciuric hypercalcaemia, caused by an autosomal dominant genetic disorder. Diagnosis is usually made by genetic testing and concordant biochemistry (urine calcium : creatinine clearance ratio <0.01-distinguished from primary hyperparathyroidism). Treatment Primary hyperparathyroidism Indications for surgery Elevated serum Calcium > 1mg/dL above normal Hypercalciuria > 400mg/day Creatinine clearance < 30% compared with normal Episode of life threatening hypercalcaemia Nephrolithiasis Age < 50 years Neuromuscular symptoms Reduction in bone mineral density of the femoral neck, lumbar spine, or distal radius of more than 2.5 standard deviations below peak bone mass (T score lower than -2.5) Secondary hyperparathyroidism Usually managed with medical therapy. Indications for surgery in secondary (renal) hyperparathyroidism: Bone pain Persistent pruritus Soft tissue calcifications Tertiary hyperparathyroidism Allow 12 months to elapse following transplant as many cases will resolve The presence of an autonomously functioning parathyroid gland may require surgery. If the culprit gland can be identified then it should be excised. Otherwise total parathyroidectomy and re-implantation of part of the gland may be required. References 1. Insogna K. Primary Hyperparathyroidism. N Engl J Med. 2018 Sep 13;379(11):1050-1059. 2. van der Plas W Y et al. Secondary and Tertiary Hyperparathyroidism: A Narrative Review. Scand J Surg. 2020 Dec;109(4):271-278.

Answer 1648

Cystic stump leaks following cholecystectomy can be managed with ERCP and stent Complications following cholecystectomy Complications following cholecystectomy Open conversion One of the largest series, published by Shea in 1996 with a total of more than 70,000 cholecystectomies analysed by pooled studies tends to list most complications as having an incidence of <1%. This includes open conversion which they identified as occurring in less than 1%. One of the interesting points raised by this data is that it covers an early period in laparoscopy and there is highly likely to be an element of selection bias in the cases put forward for laparoscopy. Indeed, some surgeons have noted their own institutions conversion rates increase (in this case 7%) as they take on increasingly complex cases. Bile leaks Where these occur they are usually the result of leakage from biliary radicles or cystic stump leaks. Many patients with a cystic stump leak can be managed with ERCP , sphincterotomy and stent. They are not common complications and have an incidence of around 1%. Bile duct injury Cholecystectomy remains the commonest cause of bile duct injury. Reported incidences range from 0.3-0.7%. The main reason is that biliary anatomy is not appreciated. Where they occur, the definitive management is reconstruction. If the operating surgeon does not regularly practise this type of surgery then the area should be drained and the patient transferred to an HPB unit.

Answer 1649

The question is about high output diarrhoea following terminal ileal resection and the most likely cause is malabsorption of bile salts. The administration of cholestyramine (bile salt binding agent) will counter this and thats why its the correct answer. Malabsorption of bile salts is a common cause of diarrhoea following ileal resection. A normal small bowel study and CRP effectively excludes active Crohns disease and therefore immunomodulator drugs are not appropriate. Ileum Anatomical overview The terminal ileum comprises 20% of the ileum and has a diameter that is smaller than that of the jejunum (typically 2cm at the ileocaecal valve). The ileum is attached to the abdominal wall by a mesentery that contains more fat than that of the jejunum. The blood supply of the ileum is derived from branches of the superior mesenteric artery, the vascular arcades of the ileum are more densely packed than those of the jejunum. The wall of the ileum contains Peyers patches which are aggregations of lymphoid tissue. Function The main function of the terminal ileum is absorption of vitamin B12 and bile salts. The neuroendocrine cells in the wall of the ileum may secrete hormones. In surgical patients, resection of the terminal ileum is a common procedure for conditions such as terminal ileal Crohns disease. Where a significant proportion of the ileum is removed, patients are at increased risk of bile salt malabsorption with the development of bile salt diarrhoea and increased risk of gallstones. The lack of vitamin B12 may pre-dispose to macrocytic anaemia.

Answer 1650

Tacrolimus is metabolised by the P450 enzyme system. This is inhibited by a number of naturally occurring substances, these include grapefruit, watercress and St.Johns Wort. These should all be avoided in immunosupressed patients taking tacrolimus. Organ transplantation: immunosuppressants A number of drugs are available which help to mitigate the processes resulting in acute rejection. Cyclosporin and tacrolimus are commonly used drugs. Example regime Initial: ciclosporin/tacrolimus with a monoclonal antibody Maintenance: ciclosporin/tacrolimus with MMF or sirolimus Add steroids if more than one steroid responsive acute rejection episode Ciclosporin Inhibits calcineurin, a phosphatase involved in T cell activation Nephrotoxic Monitor levels Azathioprine Metabolised to form 6 mercaptopurine which inhibits DNA synthesis and cell division Side effects include myelosupression, alopecia and nausea Tacrolimus Lower incidence of acute rejection compared to ciclosporin Also less hypertension and hyperlipidaemia However, high incidence of impaired glucose tolerance and diabetes Mycophenolate mofetil (MMF) Blocks purine synthesis by inhibition of IMPDH Therefore inhibits proliferation of B and T cells Side-effects: GI and marrow suppression Sirolimus (rapamycin) Blocks T cell proliferation by blocking the IL-2 receptor Can cause hyperlipidaemia Monoclonal antibodies Selective inhibitors of IL-2 receptor Daclizumab Basilximab

Answer 1651

The glossopharyngeal nerve is the main sensory nerve for the tonsillar fossa. A lesser contribution is made by the lesser palatine nerve. Because of this otalgia may occur following tonsillectomy. Tonsil Anatomy Each palatine tonsil has two surfaces, a medial surface which projects into the pharynx and a lateral surface that is embedded in the wall of the pharynx. They are usually 25mm tall by 15mm wide, although this varies according to age and may be almost completely atrophied in the elderly. Their arterial supply is from the tonsillar artery, a branch of the facial artery. Its veins pierce the constrictor muscle to join the external palatine or facial veins. The external palatine vein is immediately lateral to the tonsil, which may result in haemorrhage during tonsillectomy. Lymphatic drainage is the jugulodigastric node and the deep cervical nodes. Tonsillitis Usually bacterial (50%)- group A Streptococcus. Remainder viral. May be complicated by development of abscess (quinsy). This may distort the uvula. - Indications for tonsillectomy include recurrent acute tonsillitis, suspected malignancy, enlargement causing sleep apnoea. - Dissection tonsillectomy is the preferred technique with haemorrhage being the commonest complication. Delayed otalgia may occur owing to irritation of the glossopharyngeal nerve.

Answer 1652

Polyposis syndromes Syndrome Genetic defect Features Screening and management Associated disorders Familial adenomatous polyposis Mutation of APC gene (80%) cases, dominant Typically over 100 colonic adenomas Cancer risk of 100% 20% are new mutations If known to be at risk then predictive genetic testing as teenager Annual flexible sigmoidoscopy from 15 years If no polyps found then 5 yearly colonoscopy started at age 20 Polyps found = resectional surgery (resection and pouch Vs sub total colectomy and IRA) Gastric fundal polyps (50%). Duodenal polyps 90%. If severe duodenal polyposis cancer risk of 30% at 10 years. Abdominal desmoid tumours. MYH associated polyposis Biallelic mutation of mut Y human homologue (MYH) on chromosome 1p, recessive Multiple colonic polyps Later onset right sided cancers more common than in FAP 100% cancer risk by age 60 Once identified resection and ileoanal pouch reconstruction is recommended Attenuated phenotype - regular colonoscopy Duodenal polyposis in 30% Associated with increased risk of breast cancer (self examination) Peutz -Jeghers syndrome STK11 (LKB1) mutation on chromosome 19 in some (but not all) cases, dominant Multiple benign intestinal hamartomas Episodic obstruction and intussceception Increased risk of GI cancers (colorectal cancer 20%, gastric 5%) Increased risk of breast, ovarian, cervical pancreatic and testicular cancers Annual examination Pan intestinal endoscopy every 2-3 years Malignancies at other sites Classical pigmentation pattern Cowden disease Mutation of PTEN gene on chromosome 10q22, dominant Macrocephaly Multiple intestinal hamartomas Multiple trichilemmomas 89% risk of cancer at any site 16% risk of colorectal cancer Targeted individualised screening Breast cancer (81% risk) Thyroid cancer and non toxic goitre Uterine cancer HNPCC (Lynch syndrome) Germline mutations of DNA mismatch repair genes Colo rectal cancer 30-70% Endometrial cancer 30-70% Gastric cancer 5-10% Scanty colonic polyps may be present Colonic tumours likely to be right sided and mucinous Colonoscopy every 1-2 years from age 25 Consideration of prophylactic surgery Extra colonic surveillance recommended

Answer 1653

The combination of low platelet counts and raised FDP in this setting make DIC the most likely diagnosis. Disseminated intravascular coagulation - Diagnosis Under homeostatic conditions, coagulation and fibrinolysis are coupled. The activation of the coagulation cascade yields thrombin that converts fibrinogen to fibrin; the stable fibrin clot being the final product of hemostasis. The fibrinolytic system breaks down fibrinogen and fibrin. Activation of the fibrinolytic system generates plasmin (in the presence of thrombin), which is responsible for the lysis of fibrin clots. The breakdown of fibrinogen and fibrin results in polypeptides (fibrin degradation products). In a state of homeostasis, the presence of plasmin is critical, as it is the central proteolytic enzyme of coagulation and is also necessary for fibrinolysis. In DIC, the processes of coagulation and fibrinolysis are dysregulated, and the result is widespread clotting with resultant bleeding. Regardless of the triggering event of DIC, once initiated, the pathophysiology of DIC is similar in all conditions. One critical mediator of DIC is the release of a transmembrane glycoprotein (tissue factor =TF). TF is present on the surface of many cell types (including endothelial cells, macrophages, and monocytes) and is not normally in contact with the general circulation, but is exposed to the circulation after vascular damage. For example, TF is released in response to exposure to cytokines (particularly interleukin 1), tumor necrosis factor, and endotoxin. This plays a major role in the development of DIC in septic conditions. TF is also abundant in tissues of the lungs, brain, and placenta. This helps to explain why DIC readily develops in patients with extensive trauma. Upon activation, TF binds with coagulation factors that then triggers the extrinsic pathway (via Factor VII) which subsequently triggers the intrinsic pathway (XII to XI to IX) of coagulation. Diagnosis Fibrin degradation products are often raised. Disorder Prothrombin time APTT Bleeding time Platelet count Warfarin administration Prolonged Normal Normal Normal Aspirin administration Normal Normal Prolonged Normal Heparin Often normal (may be prolonged) Prolonged Normal Normal DIC Prolonged Prolonged Prolonged Low

Answer 1654

The proposed drop in blood pressure falls within the range within which the kidney autoregulates its blood supply. GFR will therefore remain unchanged. Renal Physiology Overview Each nephron is supplied with blood from an afferent arteriole that opens onto the glomerular capillary bed. Blood then flows to an efferent arteriole, supplying the peritubular capillaries and medullary vasa recta. The kidney receives up to 25% of resting cardiac output. Control of blood flow The kidney is able to autoregulate its blood flow between systolic pressures of 80- 180mmHg so there is little variation in renal blood flow. This is achieved by myogenic control of arteriolar tone, both sympathetic input and hormonal signals (e.g. renin) are responsible. Glomerular structure and function Blood inside the glomerulus has considerable hydrostatic pressure. The basement membrane has pores that will allow free diffusion of smaller solutes, larger negatively charged molecules such as albumin are unable to cross. The glomerular filtration rate (GFR) is equal to the concentration of a solute in the urine, times the volume of urine produced per minute, divided by the plasma concentration (assuming that the solute is freely diffused e.g. inulin). In clinical practice creatinine is used because it is subjected to very little proximal tubular secretion. Although subject to variability, the typical GFR is 125ml per minute. Glomerular filtration rate = Total volume of plasma per unit time leaving the capillaries and entering the bowman's capsule Renal clearance = volume plasma from which a substance is removed per minute by the kidneys Substances used to measure GFR have the following features: 1. Inert 2. Free filtration from the plasma at the glomerulus (not protein bound) 3. Not absorbed or secreted at the tubules 4. Plasma concentration constant during urine collection Examples: inulin, creatinine GFR = urine concentration (mmol/l) x urine volume (ml/min) -------------------------------------------------------------------------- plasma concentration (mmol/l) The clearance of a substance is dependent not only on its diffusivity across the basement membrane but also subsequent tubular secretion and / or reabsorption. So glucose which is freely filtered across the basement membrane is usually reabsorbed from tubules giving a clearance of zero. Tubular function Reabsorption and secretion of substances occurs in the tubules. In the proximal tubule substrates such as glucose, amino acids and phosphate are co-transported with sodium across the semi permeable membrane. Glucose is reabsorbed by both active and passive processes. The former uses sodiumâ€“glucose co-transporters (SGLTs) in the proximal convoluted tubule. The latter achieved through facilitated and passive process through GLUT transporters. Up to two thirds of filtered water is reabsorbed in the proximal tubules. This will lead to increase in urea concentration in the distal tubule allowing for its increased diffusion. Substances to be secreted into the tubules are taken up from the peritubular blood by tubular cells. Solutes such as paraaminohippuric acid are cleared with a single passage through the kidneys and this is why it is used to measure renal plasma flow. Ions such as calcium and phosphate will have a tubular reabsorption that is influenced by plasma PTH levels. Potassium may be both secreted and re-absorbed and is co-exchanged with sodium. Loop of Henle Approximately 60 litres of water containing 9000mmol sodium enters the descending limb of the loop of Henle in 24 hours. Loops from the juxtamedullary nephrons run deep into the medulla. The osmolarity of fluid changes and is greatest at the tip of the papilla. The thick ascending limb is impermeable to water, but highly permeable to sodium and chloride ions. This loss means that at the beginning of the thick ascending limb the fluid is hypo osmotic compared with adjacent interstitial fluid. In the thick ascending limb the reabsorption of sodium and chloride ions occurs by both facilitated and passive diffusion pathways. The loops of Henle are co-located with vasa recta, these will have similar solute compositions to the surrounding extracellular fluid so preventing the diffusion and subsequent removal of this hypertonic fluid. The energy dependent reabsorption of sodium and chloride in the thick ascending limb helps to maintain this osmotic gradient.

Answer 1655

The spleen is commonly torn by traction injuries in colonic surgery. The other structures are associated with bleeding during colonic surgery but would not manifest themselves as blood in the paracolic gutter prior to incision of the paracolonic peritoneal edge. Left colon Position As the left colon passes inferiorly its posterior aspect becomes extraperitoneal, and the ureter and gonadal vessels are close posterior relations that may become involved in disease processes At a level of L3-4 (variable) the left colon becomes the sigmoid colon and wholly intraperitoneal once again The sigmoid colon is a highly mobile structure and may even lie on the right side of the abdomen It passes towards the midline, the taenia blend and this marks the transition between sigmoid colon and upper rectum Blood supply Inferior mesenteric artery However, the marginal artery (from the right colon) contributes, this contribution becomes clinically significant when the IMA is divided surgically (e.g. During AAA repair)

Answer 1656

Since TPN solutions are irritant to veins they are best administered via a central line. The femoral route has a higher incidence of line associated sepsis and is thus best avoided in this setting. Parenteral feeding-NICE guidelines Parenteral nutrition: NICE guidelines summary Identify patients as malnourished or at risk Patients identified as being malnourished- BMI < 18.5 kg/m2 unintentional weight loss of > 10% over 3-6/12 BMI < 20 kg/m2 and unintentional weight loss of > 5% over 3-6/12 AT RISK of malnutrition- eaten nothing or little > 5 days, who are likely to eat little for a further 5 days poor absorptive capacity high nutrient losses high metabolism Identify unsafe/inadequate oral intake OR a non functional GI tract/perforation/inaccessible Consider parenteral nutrition: for feeding < 14 days consider feeding via a peripheral venous catheter for feeding > 30 days use a tunneled subclavian line continuous administration in severely unwell patients if feed needed > 2 weeks consider changing from continuous to cyclical feeding don't give > 50% of daily regime to unwell patients in first 24-48 hours Surgical patients: if malnourished with unsafe swallow OR a non functional GI tract/perforation/inaccessible then consider peri operative parenteral feeding.

Answer 1657

Adenoid cystic carcinoma commonly infiltrates the facial nerve and may cause neuropathy and facial pain. Parotid gland clinical Benign neoplasms Up to 80% of all salivary gland tumours occur in the parotid gland and up to 80% of these are benign. There is no consistent correlation between the rate of growth and the malignant potential of the lesion. However, benign tumours should not invade structures such as the facial nerve. With the exception of Warthins tumours, they are commoner in women than men. The median age of developing a lesion is in the 5th decade of life. Benign tumour types Tumour type Features Benign pleomorphic adenoma or benign mixed tumor Most common parotid neoplasm (80%) Proliferation of epithelial and myoepithelial cells of the ducts and an increase in stromal components Slow growing, lobular, and not well encapsulated Recurrence rate of 1-5% with appropriate excision (parotidectomy) Recurrence possibly secondary to capsular disruption during surgery Malignant degeneration occurring in 2-10% of adenomas observed for long periods, with carcinoma ex-pleomorphic adenoma occurring most frequently as adenocarcinoma Warthin tumor (papillary cystadenoma lymphoma or adenolymphoma) Second most common benign parotid tumor (5%) Most common bilateral benign neoplasm of the parotid Marked male as compared to female predominance Occurs later in life (sixth and seventh decades) Presents as a lymphocytic infiltrate and cystic epithelial proliferation May represent heterotopic salivary gland epithelial tissue trapped within intraparotid lymph nodes Incidence of bilaterality and multicentricity of 10% Malignant transformation rare (almost unheard of) Monomorphic adenoma Account for less than 5% of tumours Slow growing Consist of only one morphological cell type (hence term mono) Include; basal cell adenoma, canalicular adenoma, oncocytoma, myoepitheliomas Haemangioma Should be considered in the differential of a parotid mass in a child Accounts for 90% of parotid tumours in children less than 1 year of age Hypervascular on imaging Spontaneous regression may occur and malignant transformation is almost unheard of Malignant salivary gland tumours Types of malignancy Mucoepidermoid carcinoma 30% of all parotid malignancies Usually low potential for local invasiveness and metastasis (depends mainly on grade) Adenoid cystic carcinoma Unpredictable growth pattern Tendency for perineural spread Nerve growth may display skip lesions resulting in incomplete excision Distant metastasis more common (visceral rather than nodal spread) 5 year survival 35% Mixed tumours Often a malignancy occurring in a previously benign parotid lesion Acinic cell carcinoma Intermediate grade malignancy May show perineural invasion Low potential for distant metastasis 5 year survival 80% Adenocarcinoma Develops from secretory portion of gland Risk of regional nodal and distant metastasis 5 year survival depends upon stage at presentation, may be up to 75% with small lesions with no nodal involvement Lymphoma Large rubbery lesion, may occur in association with Warthins tumours Diagnosis should be based on regional nodal biopsy rather than parotid resection Treatment is with chemotherapy (and radiotherapy) Diagnostic evaluation Plain x-rays may be used to exclude calculi Sialography may be used to delineate ductal anatomy FNAC is used in most cases Superficial parotidectomy may be either diagnostic or therapeutic depending upon the nature of the lesion Where malignancy is suspected the primary approach should be definitive resection rather than excisional biopsy CT/ MRI may be used in cases of malignancy for staging primary disease Treatment For nearly all lesions this consists of surgical resection, for benign disease this will usually consist of a superficial parotidectomy. For malignant disease a radical or extended radical parotidectomy is performed. The facial nerve is included in the resection if involved. The need for neck dissection is determined by the potential for nodal involvement. Other parotid disorders HIV infection Lymphoepithelial cysts associated with HIV occur almost exclusively in the parotid Typically presents as bilateral, multicystic, symmetrical swelling Risk of malignant transformation is low and management usually conservative Sjogren syndrome Autoimmune disorder characterised by parotid enlargement, xerostomia and keratoconjunctivitis sicca 90% of cases occur in females Second most common connective tissue disorder Bilateral, non tender enlargement of the gland is usual Histologically, the usual findings are of a lymphocytic infiltrate in acinar units and epimyoepithelial islands surrounded by lymphoid stroma Treatment is supportive There is an increased risk of subsequent lymphoma Sarcoid Parotid involvement occurs in 6% of patients with sarcoid Bilateral in most cases Gland is not tender Xerostomia may occur Management of isolated parotid disease is usually conservative

Answer 1658

With long standing very large goitre, there is a risk of tracheomalacia. In the UK this is very rarely seen. However, patients from other countries can have enourmous goitres and this then becomes a concern. The fact that the wound is satisfactory makes a bleed less likely and whilst total thyroidectomy can be a risk factor for hypocalcaemia, this is a little early. Complications following thyroid surgery The major immediate risk following thyroidectomy is haemorrhage. A tension haematoma deep to the cervical fascia is usually the result of reactionary haemorrhage from an arterial source. This results in the development of laryngeal oedema and airway compromise. The treatment is by urgent wound decompression of all layers prior to return to theatre for haemostasis. Sub cutnaeous haematomas and seromas may accumulate under skin flaps and can often be managed conservatively or by simple aspiration. In patients with longstanding large goitres there is the risk of tracheomalacia. This is characterised by the development of flacidity of the tracheal cartilage. This can result in airway compromise. In the normal situation the tracheal diameter increases slightly during inspiration and narrows during expiration. In tracheomalacia these processes are exaggerated and the trachea may collapse in expiration resulting in stridor. In the immediate situation an endotracheal tube will need to be inserted. Recurrent laryngeal nerve injury is recognised following thyroid surgery and may be unilateral or bilateral depending upon the procedure performed. The risk is 1.8% at one month which declines to 0.5% at three months following first time explorations. It is rare for nerve injury alone to result in airway compromise. However, it may occur when nerve injury is associated with minor degrees of laryngeal oedema (such as following intubation). Hypoparathyroidism is a recognised complication following thyroid surgery and damage to the blood supply to the parathyroid glands is probably the commonest cause. The incidence of permanent hypoparathyroidism is in the region of 1 to 3%. It can present dramatically in the first 2-5 post operative days. In the emergency setting treatment is with intravenous calcium gluconate. Oral calcium carbonate is used in the longer term.

Answer 1659

Since this comparison with practice against an agreed standard, the correct course of action is to undertake an audit. Audit and Research Clinical audit Quality improvement process that seeks to improve patient care and outcomes through systematic review of care against explicit criteria and the implementation of change. Aspects of the structure, processes, and outcomes of care are selected and systematically evaluated against explicit criteria. Where indicated, changes are implemented at an individual, team, or service level and further monitoring is used to confirm improvement in healthcare delivery. (NICE). Research Aims to derive new knowledge which is potentially generalisable or transferable.

Answer 1660

Flumazenil antagonises the effects of benzodiazepines by competition at GABA binding sites. Since many benzodiazepines have longer half lives than flumazenil patients still require close monitoring after receiving the drug. Whilst doxapram would increase the respiratory rate, it is not an agent for reversal of midazolam. Anaesthetic agents The table below summarises some of the more commonly used IV induction agents Agent Specific features Propofol Rapid onset of anaesthesia Pain on IV injection Rapidly metabolised with little accumulation of metabolites Proven anti emetic properties Moderate myocardial depression Widely used especially for maintaining sedation on ITU, total IV anaesthesia and for daycase surgery Sodium thiopentone Extremely rapid onset of action making it the agent of choice for rapid sequence of induction Marked myocardial depression may occur Metabolites build up quickly Unsuitable for maintenance infusion Little analgesic effects Ketamine May be used for induction of anaesthesia Has moderate to strong analgesic properties Produces little myocardial depression making it a suitable agent for anaesthesia in those who are haemodynamically unstable May induce state of dissociative anaesthesia resulting in nightmares Etomidate Has favorable cardiac safety profile with very little haemodynamic instability No analgesic properties Unsuitable for maintaining sedation as prolonged (and even brief) use may result in adrenal suppression Post operative vomiting is common

Answer 1661

The symptoms are typical for prostatic disease. Benign prostatic disease BPH is increasingly common with advancing age and is present in 50% over the age of 60 and nearly 90% of men by the age of 90. It occurs as a result of hyperplasia of the periurethral glands in the transitional zone of the prostate. Androgens play a role in the development and progression of BPH. Testosterone diffuses into prostatic and stromal cells. Within epithelial cells it binds to the androgen receptor. In prostatic stromal cells, a small proportion binds directly to the androgen receptor, the majority binds to the 5 alpha reductase type II receptor on the nuclear membrane. This is converted to dihyroxytestosterone and then binds to the androgen receptor. Dihydroxytestosterone has even greater affinity for the androgen receptor than testosterone does. The end result is stimulation of these cells and proliferation. This proliferative activity results in varying degrees of obstruction and results in lower urinary tract obstructive symptoms. The clinical diagnosis of BPH thus comprise a degree of lower urinary tract symptoms, palpable prostatic enlargement and evidence of impaired voiding on urodynamic assessment. Presentation Some patients have minimal symptoms, yet, on examination, have a palpable bladder and obstructive post renal failure. LUTS can be divided into two main groups; obstructive symptoms with voiding that include hesitancy, poor stream, straining, prolonged micturition and dribbling; others develop irritation symptoms which include pain during bladder filling, frequency, urgency and nocturia. Some present with retention and haematuria. Diagnosis Abdominal and rectal examination Symptoms scoring Urodynamic studies ( a post void volume of >100ml is significant) Management Conservative Alpha adrenergic antagonists. These block the action of noradrenaline on prostatic smooth muscle causing relaxation and improved bladder emptying. 5 alpha reductase inhibitors. Finasteride blocks the enzyme 5 alpha reductase which inhibits the conversion of testosterone to DHT. This in turn reduces intracellular activity and decreases prostatic volume Surgery- TURP is the gold standard. Occasionally, an open retropubic prostatectomy may be considered for a large gland.

Answer 1662

A combination of sepsis and jaundice generally favors a diagnosis of cholangitis. Conditions such as empyema may cause sepsis but not marked jaundice, the same is also true of the other differentials listed. Gallstones Up to 24% of women and 12% of men may have gallstones. Of these up to 30% may develop local infection and cholecystitis. In patients subjected to surgery 12% will have stones contained within the common bile duct. The majority of gallstones are of a mixed composition (50%) with pure cholesterol stones accounting for 20% of cases. The aetiology of CBD stones differs in the world, in the West most CBD stones are the result of migration. In the East a far higher proportion arise in the CBD de novo. The classical symptoms are of colicky right upper quadrant pain that occurs post prandially. The symptoms are usually worst following a fatty meal when cholecystokinin levels are highest and gallbladder contraction is maximal. Investigation In almost all suspected cases the standard diagnostic work up consists of abdominal ultrasound and liver function tests. Of patients who have stones within the bile duct, 60% will have at least one abnormal result on LFT's. Ultrasound is an important test, but is operator dependent and therefore may occasionally need to be repeated if a negative result is at odds with the clinical picture. Where stones are suspected in the bile duct, the options lie between magnetic resonance cholangiography and intraoperative imaging. The choice between these two options is determined by the skills and experience of the surgeon. The advantages of intra operative imaging are less useful in making therapeutic decisions if the operator is unhappy about proceeding the bile duct exploration, and in such circumstances pre operative MRCP is probably a better option. Specific gallstone and gallbladder related disease Disease Features Management Biliary colic Colicky abdominal pain, worse post prandially, worse after fatty foods If imaging shows gallstones and history compatible then laparoscopic cholecystectomy Acute cholecystitis Right upper quadrant pain Fever Murphys sign on examination Occasionally mildly deranged LFT's (especially if Mirizzi syndrome) Imaging (USS) and cholecystectomy (ideally within 48 hours of presentation) (2) Gallbladder abscess Usually prodromal illness and right upper quadrant pain Swinging pyrexia Patient may be systemically unwell Generalised peritonism not present Imaging with USS +/- CT Scanning Ideally surgery, sub total cholecystectomy may be needed if Calots triangle is hostile In unfit patients percutaneous drainage may be considered Cholangitis Patient severely septic and unwell Jaundice Right upper quadrant pain Fluid resuscitation Broad spectrum intravenous antibiotics Correct any coagulopathy Early ERCP Gallstone ileus Patients may have a history of previous cholecystitis and known gallstones Small bowel obstruction (may be intermittent) Laparotomy and removal of gallstone from small bowel, the enterotomy must be made proximal to the site of obstruction and not at the site of obstruction. The fistula between the gallbladder and duodenum should not be interfered with. Acalculous cholecystitis Patients with inter current illness (e.g. diabetes, organ failure) Patient of systemically unwell Gallbladder inflammation in absence of stones High fever If patient fit then cholecystectomy, if unfit then percutaneous cholecystostomy Treatment Patients with asymptomatic gallstones rarely develop symptoms related to them (less than 2% per year) and may therefore be managed expectantly. In almost all cases of symptomatic gallstones the treatment of choice is cholecystectomy performed via the laparoscopic route. In the very frail patient there is sometimes a role for selective use of ultrasound guided cholecystostomy. During the course of the procedure some surgeons will routinely perform either intra operative cholangiography or laparoscopic USS to either confirm anatomy or to exclude CBD stones. The latter may be more easily achieved by use of laparoscopic ultrasound. If stones are found then the options lie between early ERCP in the day or so following surgery or immediate surgical exploration of the bile duct. When performed via the trans cystic route this adds little in the way of morbidity and certainly results in faster recovery. Where transcystic exploration fails the alternative strategy is that of formal choledochotomy. The exploration of a small duct is challenging and ducts of less than 8mm should not be explored. Small stones that measure less than 5mm may be safely left and most will pass spontaneously. Risks of ERCP(1) Bleeding 0.9% (rises to 1.5% if sphincterotomy performed) Duodenal perforation 0.4% Cholangitis 1.1% Pancreatitis 1.5% References 1. Williams E et al. Guidelines on the management of common bile duct stones (CBDS)Gut 2008;57:10041021 2. Gurusamy KS, Samraj K. Early versus delayed laparoscopic cholecystectomy for acute cholecystitis. Cochrane Database Syst Rev. 2006 Oct 18;(4):CD005440. 3. Gurusamy K and Davidson B. Gallstones. BMJ 2014 (348):27-30.

Answer 1663

In this scenario the patient will have a compartment syndrome, delayed diagnosis and muscle death. The effect of muscle death will result in the release of potassium. It is also highly likely that there will be a degree of renal impairment, the result of which is that the serum potassium is likely to be high. In this scenario the patient will have a compartment syndrome, delayed diagnosis and muscle death. The effect of muscle death will result in the release of potassium. It is also highly likely that there will be a degree of renal impairment, the result of which is that the serum potassium is likely to be high.

Answer 1664

Pelvic fractures may cause laceration of the urethra. Urinary retention, blood at the urethral meatus and a high riding prostate on digital rectal examination are the typical features. Lower genitourinary tract trauma Most bladder injuries occur due to blunt trauma 85% associated with pelvic fractures Easily overlooked during assessment in trauma Up to 10% of male pelvic fractures are associated with urethral or bladder injuries Types of injury Urethral injury Mainly in males Blood at the meatus (50% cases) There are 2 types: i.Bulbar rupture - most common - straddle type injury e.g. bicycles - triad signs: urinary retention, perineal haematoma, blood at the meatus ii. Membranous rupture - can be extra or intraperitoneal - commonly due to pelvic fracture - Penile or perineal oedema/ hematoma - PR: prostate displaced upwards (beware co-existing retroperitoneal haematomas as they may make examination difficult) - Investigation: ascending urethrogram - Management: suprapubic catheter (surgical placement, not percutaneously) External genitalia injuries (i.e., the penis and the scrotum) Secondary to injuries caused by penetration, blunt trauma, continence- or sexual pleasure-enhancing devices, and mutilation Bladder injury rupture is intra or extraperitoneal presents with haematuria or suprapubic pain history of pelvic fracture and inability to void: always suspect bladder or urethral injury inability to retrieve all fluid used to irrigate the bladder through a Foley catheter indicates bladder injury investigation- IVU or cystogram management: laparotomy if intraperitoneal, conservative if extraperitoneal

Answer 1665

This man needs a bypass operation. Using PTFE alone will not give a good result as sub intimal hyperplasia will give poor outcome early. Using a vein cuff (Miller cuff) at the end of a PTFE graft will improve the situation. Varicose veins means that vein cannot be reliably used as a conduit. However, the construction of a Miller vein cuff can be done with vein from another anatomical site. Peripheral vascular disease Indications for surgery to revascularise the lower limb Intermittent claudication Critical ischaemia Ulceration Gangrene Intermittent claudication that is not disabling may provide a relative indication, whilst the other complaints are often absolute indications depending upon the frailty of the patient. Assessment Clinical examination Ankle brachial pressure index measurement Duplex arterial ultrasound Angiography (standard, CT or MRI): usually performed only if intervention being considered. Angioplasty In order for angioplasty to be undertaken successfully the artery has to be accessible. The lesion relatively short and reasonable distal vessel runoff. Longer lesions may be amenable to sub-intimal angioplasty. Surgery Surgery will be undertaken where attempts at angioplasty have either failed or are unsuitable. Bypass essentially involves bypassing the affected arterial segment by utilising a graft to run from above the disease to below the disease. As with angioplasty good runoff improves the outcome. Some key concepts with bypass surgery Superficial femoral artery occlusion to the above knee popliteal In the ideal scenario, vein (either in situ or reversed LSV) would be used as a conduit. However, prosthetic material has reasonable 5 year patency rates and some would advocate using this in preference to vein so that vein can be used for other procedures in the future. In general terms either technique is usually associated with an excellent outcome (if run off satisfactory). Procedure Artery dissected out, IV heparin 3,000 units given and then the vessels are cross clamped Longitudinal arteriotomy Graft cut to size and tunneled to arteriotomy sites Anastomosis to femoral artery usually with 5/0 'double ended' Prolene suture Distal anastomosis usually using 6/0 'double ended' Prolene Distal disease Femoro-distal bypass surgery takes longer to perform, is more technically challenging and has higher failure rates. In elderly diabetic patients with poor runoff a primary amputation may well be a safer and more effective option. There is no point in embarking on this type of surgery in patients who are wheelchair bound. In femorodistal bypasses vein gives superior outcomes to PTFE. Rules Vein mapping 1st to see whether there is suitable vein (the preferred conduit). Sub intimal hyperplasia occurs early when PTFE is used for the distal anastomosis and will lead to early graft occlusion and failure. Essential operative procedure as for above knee fem-pop. If there is insufficient vein for the entire conduit then vein can be attached to the end of the PTFE graft and then used for the distal anastomosis. This type of 'vein boot' is technically referred to as a Miller Cuff and is associated with better patency rates than PTFE alone. Remember the more distal the arterial anastomosis the lower the success rate. References Peach G et al. Diagnosis and management of peripheral arterial disease. BMJ 2012; 345: 36-41.

Answer 1666

Triad of Wernicke encephalopathy: Acute confusion Ataxia Ophthalmoplegia This patient has received a carbohydrate rich diet without any thiamine or vitamin B co strong replacement. This has led to Wernickes encephalopathy, which classically presents with confusion, ataxia and ophthalmoplegia. Characteristically it is associated with chronic alcoholism, however it is also known to occur post bariatric surgery. Nutrition - Refeeding syndrome Refeeding syndrome describes the metabolic abnormalities which occur on feeding a person following a period of starvation. The metabolic consequences include: Hypophosphataemia Hypokalaemia Hypomagnesaemia Abnormal fluid balance These abnormalities can lead to organ failure. Re-feeding problems If patient not eaten for > 5 days, aim to re-feed at < 50% energy and protein levels High risk for re-feeding problems If one or more of the following: BMI < 16 kg/m2 Unintentional weight loss >15% over 3-6 months Little nutritional intake > 10 days Hypokalaemia, Hypophosphataemia or hypomagnesaemia prior to feeding (unless high) If two or more of the following: BMI < 18.5 kg/m2 Unintentional weight loss > 10% over 3-6 months Little nutritional intake > 5 days History of: alcohol abuse, drug therapy including insulin, chemotherapy, diuretics and antacids Prescription Start at up to 10 kcal/kg/day increasing to full needs over 4-7 days Start immediately before and during feeding: oral thiamine 200-300mg/day, vitamin B co strong 1 tds and supplements Give K+ (2-4 mmol/kg/day), phosphate (0.3-0.6 mmol/kg/day), magnesium (0.2-0.4 mmol/kg/day)

Answer 1667

Respiratory physiology: lung compliance Lung compliance is defined as change in lung volume per unit change in airway pressure Causes of increased compliance age emphysema - this is due to loss of alveolar walls and associated elastic tissue Causes of decreased compliance pulmonary oedema pulmonary fibrosis pneumonectomy kyphosis

Answer 1668

Inhibition of insulin release: Alpha adrenergic drugs Beta blockers Sympathetic nerves Insulin Insulin is a peptide hormone, produced by beta cells of the pancreas, and is central to regulating carbohydrate and fat metabolism in the body. Insulin causes cells in the liver, skeletal muscles, and fat tissue to absorb glucose from the blood. In the liver and skeletal muscles, glucose is stored as glycogen, and in fat cells (adipocytes) it is stored as triglycerides. Structure The human insulin protein is composed of 51 amino acids, and has a molecular weight of 5808 Da. It is a dimer of an A-chain and a B-chain, which are linked together by disulfide bonds. Synthesis Pro-insulin is formed by the rough endoplasmic reticulum in pancreatic beta cells. Then pro-insulin is cleaved to form insulin and C-peptide. Insulin is stored in secretory granules and released in response to Ca2+. Function Secreted in response to hyperglycaemia Glucose utilisation and glycogen synthesis Inhibits lipolysis Reduces muscle protein loss

Answer 1669

The LFTs clearly show a cholestatic picture. Given the background of HIV the most likely cause is sclerosing cholangitis. HIV: biliary and pancreatic disease The most common cause of biliary disease in patients with HIV is sclerosing cholangitis due to infections such as CMV, Cryptosporidium and Microsporidia Pancreatitis in the context of HIV infection may be secondary to anti-retroviral treatment (especially didanosine) or by opportunistic infections e.g. CMV

Answer 1670

C-With all the other options the patient should have conservative management for a minimum of 6 months first. The patient with COPD should be considered for a less invasive intervention first e.g. intra gastric balloon. Bariatric surgery Obesity is a major health problem in the Western world. Surgical solutions to the problem have evolved dramatically over the past few years. Randomised controlled trials have shown that dramatic weight loss can be achieved following surgical interventions compared with standard medical therapy. The weight loss process is also more durable following surgery than with non surgical interventions. Case selection BMI >/= 40 kg/m2 or between 35-40 kg/m2 and other significant disease (for example, type 2 diabetes, hypertension) that could be improved with weight loss. Pre-requisites to surgery (NICE UK Guidelines) All non-surgical measures have failed to achieve or maintain adequate clinically beneficial weight loss for at least 6 months. Will receive intensive specialist management They are generally fit for anaesthesia and surgery They commit to the need for long-term follow-up First-line option for adults with a BMI > 40 kg/m2 in whom surgical intervention is considered appropriate; consider orlistat if there is a long waiting list. Surgical options Adjustable gastric band Laparoscopic placement of adjustable band around proximal stomach. Contains an adjustable filling port Effective method for lifestyle control Reversible Takes longer to achieve target weight Complications such as band erosion (rare), slippage or loss of efficacy may require re-intervention Gastric bypass Combines changes to reservoir size with malabsorptive procedure for more enduring weight loss. Technically more challenging Risks related to anastomoses (2% leak rate) Irreversible Up to 50% may become B12 deficient Sleeve gastrectomy Resection of stomach using stapling devices Less popular now as initial promising results not sustained References 1. National Institute for Health and Clinical Excellence. Obesity: the prevention, identification, assessment and management of overweight and obesity in adults and children. www.nice.org.uk/CG189 2. Leff DR, Heath D. Surgery for obesity in adulthood. BMJ 2009;339:b3402

Answer 1671

This is likely to be a venous ulcer and should usually be managed with compression bandaging if there is no arterial compromise. Long standing lesions may be complicated by the development of malignancy and for this reason a punch biopsy of long standing or non healing lesions is advisable. Treatment of suspicious skin lesions Skin lesions may be referred to surgeons for treatment or discovered incidentally. The table below outlines the various therapeutic options: Method Indication Tru-cut biopsy Most often used for percutaneous sampling of deep seated lesions or used intra operatively for visceral lesions 5mm punch biopsy Used for diagnostic confirmation of lesions that are suspected to be benign or where the definitive management is unlikely to be surgical. Of limited usefulness in pigmented lesions where they do not include sufficient tissue for accurate diagnosis. May be used in non melanoma type skin disease to establish diagnosis prior to more extensive resection. Wide excision Where the complete excision of the lesion (with healthy margins) is the main objective. In cosmetically sensitive sites, or where the defect is large, this may need to be complemented with plastic surgical techniques Incisional biopsy Used mainly for deep seated or extensive lesions where there is diagnostic doubt (usually following core or tru-cut biopsy). Used rarely for skin lesions. Diagnostic excision Primarily used for lesions that are suspicious for melanoma, the lesion is excised with a rim of normal tissue. Excision of margins may be required subsequently.

Answer 1672

Calculate routine maintenance IV fluid rates for children and young people using the HollidaySegar formula (100 ml/kg/day for the first 10 kg of weight, 50 ml/kg/day for the next 10 kg and 20 ml/kg/day for the weight over 20 kg). Be aware that over a 24hour period, males rarely need more than 2500 ml and females rarely need more than 2000 ml of fluids. From birth to day 1: 50-60 ml/kg/day. Day 2: 70-80 ml/kg/day. Day 3: 80-100 ml/kg/day. Day 4: 100-120 ml/kg/day. Days 5-8: 120-150 ml/kg/day. Paediatric fluid management Since 2000 there have been at least 4 reported deaths from fluid induced hyponatraemia in children. This led to the National Patient Safety Agency introducing revised guidelines in 2007. These have been reviewed and extensively updated by NICE in 2015 and further modified in 2020. Indications for IV fluids include: Resuscitation and circulatory support Replacing on-going fluid losses Maintenance fluids for children for whom oral fluids are not appropriate Correction of electrolyte disturbances Fluids to be avoided Outside the neonatal period saline / glucose solutions should not be given. The greatest risk is with saline 0.18 / glucose 4% solutions. The report states that 0.45% saline / 5% glucose may be used. But preference should be given to isotonic solutions and few indications exist for this solution either. The key point emphasised in the NICE guidelines in the avoidance of glucose containing solutions and instead of routinely giving glucose IV to children and neonates, the blood glucose levels should be monitored. In neonates in the first few days of life, sodium levels in the range of 131-154 mmol/l may be too high and a neonatologist consulted on a case by case basis. Fluids to be used If children and young people need IV fluids for routine maintenance, initially use isotonic crystalloids that contain sodium in the range 131 to 154 mmol/litre Potassium should be added to maintenance fluids according patients plasma potassium levels (which should be monitored). Blood glucose levels should be monitored in individuals at risk of hypoglycaemia Intraoperative fluid management If children and young people need IV fluids for routine maintenance, initially use isotonic crystalloids that contain sodium in the range 131 to 154 mmol/litre Blood glucose levels should be monitored Maintenance fluids Weight Water requirement/kg/day Na mmol/kg/day K mmol/kg/day First 10Kg body weight 100ml 2-4 1.5-2.5 Second 10Kg body weight 50ml 1-2 0.5-1.5 Subsequent Kg 20ml 0.5-1.0 0.2-0.7 Blood glucose will need to be monitored Reference NPSA -reducing risk of hyponatraemia when administering intravenous fluids to children. Issue date March 2007. Further references included in this document. NICE Guidance NG29. Intravenous fluid therapy in children and young people in hospital. Published 2015, reviewed an updated 2020.

Answer 1673

This patient is likely to have a paralytic ileus and the administration of anti emetic drugs in this situation achieves very little. It's important to decompress the stomach and this can be achieved with a wide bore nasogastric tube. Vomiting Reflex oral expulsion of gastric (and sometimes intestinal) contents - reverse peristalsis and abdominal contraction The vomiting centre is in part of the medulla oblongata and is triggered by receptors in several locations: Labyrinthine receptors of ear (motion sickness) Over distention receptors of duodenum and stomach Trigger zone of CNS - many drugs (e.g., opiates) act here Touch receptors in throat

Answer 1674

Adductor longus is supplied by the obturator nerve. Femoral nerve Root values L2, 3, 4 Innervates Pectineus Sartorius Quadriceps femoris Vastus lateralis/medialis/intermedius Rectus femoris Branches Medial cutaneous nerve of thigh Saphenous nerve Intermediate cutaneous nerve of thigh Path Penetrates psoas major and exits the pelvis by passing under the inguinal ligament to enter the femoral triangle, lateral to the femoral artery and vein. Mnemonic for femoral nerve supply (don't) M I S V Q Scan for PE M edial cutaneous nerve of the thigh I ntermediate cutaneous nerve of the thigh S aphenous nerve V astus Q uadriceps femoris S artorius PE ectineus

Answer 1675

A locally perforated colonic tumour will typically cause an intense inflammatory response and if peritonitis is not present clinically then at the very least a localised abscess. This inflammatory process is the most likely (from the list) to falsely raise the serum ferritin level. Angiodysplasia and dieulafoy lesions are mucosal arteriovenous malformations and unlikely to result in considerable inflammatory activity. Ferritin Ferritin is an intracellular protein that binds iron and stores it to be released in a controlled fashion at sites where iron is required. Because iron and ferritin are bound the total body ferritin levels may be decreased in cases of iron deficiency anaemia. Measurement of serum ferritin levels can be useful in determining whether an apparently low haemoglobin and microcytosis is truly caused by an iron deficiency state. Ferritin is an acute phase protein and may be synthesised in increased quantities in situations where inflammatory activity is ongoing. Falsely elevated results may therefore be encountered clinically and need to be taken in context of the clinical picture and full blood count results.

Answer 1676

Granulomas (which occur in tuberculosis) are a feature of Type 4 hypersensitivity reactions. Hypersensitivity reactions The Gell and Coombs classification divides hypersensitivity reactions into 4 types Type I Type II Type III Type IV Description Anaphylactic Cytotoxic Immune complex Delayed type Mediator IgE IgG, IgM IgG, Ig A, IgM T-cells Antigen Exogenous Cell surface Soluble Tissues Response time Minutes Hours Hours 2-3 days Examples Asthma Hay fever Autoimmune haemolytic anaemia Pemphigus Goodpasture's Serum sickness SLE Aspergillosis Graft versus host disease Contact dermatitis

Answer 1677

Kiesselbachs plexus has an arterial supply derived from both the internal and external carotid arteries and is the commonest area for bleeding in idiopathic epistaxis. Epistaxis Usually trivial and insignificant but severe haemorrhage may compromise airway and pose a risk to life. Anatomy: Arterial supply From internal and external carotid An arterial plexus exists at Little's area and is the source of bleeding in 90% cases Major arterial supply is from the sphenopalatine and greater palatine arteries (branches of the maxillary artery) The facial artery supplies the more anterior aspect of the nose Ethmoidal arteries are branches of the ophthalmic artery. They supply the posterosuperior nasal cavity Venous drainage follows the arterial pattern Classification Primary idiopathic epistaxis accounts for 75% of all cases Secondary cases arise as a result of events such as anticoagulants, trauma and coagulopathy Classification into anterior and posterior epistaxis may help to locate the source and becomes more important when invasive treatment is required Management Resuscitate if required Subject should sit upright and pinch nose firmly Nasal cavity should be examined using a headlight Simple anterior epistaxis may be managed using silver nitrate cautery. If difficult to manage then custom manufactured packs may be inserted Posterior packing or tamponade may be achieved by passing a balloon tamponade device and inflating it. This is indicated where anterior packing alone has failed to achieve haemostasis. Post nasal pack patients should receive antibiotics Failure of these methods will require more invasive therapy. Where a vascular radiology suite is available, consideration may be given to angiographic techniques. Direct ligation of the nasal arterial supply may also be undertaken. Of the arterial ligation techniques available, the endo nasal sphenopalatine arterial ligation procedure is most popular.

Answer 1678

Pseudomyxoma is classically associated with mucin production and the appendix is the commonest source. Pseudomyxoma Peritonei Rare mucinous tumour Most commonly arising from the appendix (other abdominal viscera are also recognised as primary sites) Incidence of 1-2/1,000,000 per year The disease is characterised by the accumulation of large amounts of mucinous material in the abdominal cavity Treatment Is usually surgical and consists of cytoreductive surgery (and often peritonectomy c.f Sugarbaker procedure) combined with intra peritoneal chemotherapy with mitomycin C. Survival is related to the quality of primary treatment and in Sugarbakers own centre 5 year survival rates of 75% have been quoted. Patients with disseminated intraperitoneal malignancy from another source fare far worse. In selected patients a second look laparotomy is advocated and some practice this routinely.

Answer 1679

TCC of the renal pelvis may seed down the ureter. Renal tumours Renal cell carcinoma Renal cell carcinoma is an adenocarcinoma of the renal cortex and is believed to arise from the proximal convoluted tubule. They are usually solid lesions, up to 20% may be multifocal, 20% may be calcified and 20% may have either a cystic component or be wholly cystic. They are often circumscribed by a pseudocapsule of compressed normal renal tissue. Spread may occur either by direct extension into the adrenal gland, renal vein or surrounding fascia. More distant disease usually occurs via the haematogenous route to lung, bone or brain. Renal cell carcinoma comprise up to 85% of all renal malignancies. Males are more commonly affected than females and sporadic tumours typically affect patients in their sixth decade. Patients may present with a variety of symptoms including; haematuria (50%), loin pain (40%), mass (30%) and up to 25% may have symptoms of metastasis.Less than 10% have the classic triad of haematuria, pain and mass. Investigation Many cases will present as haematuria and be discovered during diagnostic work up. Benign renal tumours are rare, so renal masses should be investigated with multislice CT scanning. Most tumours are also characterised with an arterial phase CT, particularly if they may be suitable for partial nephrectomy. CT scanning of the chest and abdomen to detect distant disease should also be undertaken. Routine bone scanning is not indicated in the absence of symptoms. Biopsy should not be performed when a nephrectomy is planned but is mandatory before any ablative therapies are undertaken. Assessment of the functioning of the contra lateral kidney. Management T1 lesions may be managed by partial nephrectomy and this gives equivalent oncological results to total radical nephrectomy. Partial nephrectomy may also be performed when there is inadequate reserve in the remaining kidney. Ablative techniques may also be considered for small T1 lesions in unfit patients. In general, outcomes are less favorable than with surgical resection. For T2 lesions and above a radical nephrectomy is standard practice and this may be performed via a laparoscopic or open approach. Preoperative embolisation is not indicated nor is resection of uninvolved adrenal glands. During surgery early venous control is mandatory to avoid shedding of tumour cells into the circulation. Patients with completely resected disease do not benefit from adjuvant therapy with either chemotherapy or biological agents. These should not be administered outside the setting of clinical trials. Patients with transitional cell cancer will require a nephroureterectomy with disconnection of the ureter at the bladder. References Capitanio U, Montorsi F. Renal cancer. Lancet. 2016 Feb 27;387(10021):894-906. Capitanio U et al. Epidemiology of Renal Cell Carcinoma. Eur Urol. 2019 Jan;75(1):74-84.

Answer 1680

Wilms tumours (nephroblastoma) usually present in the first 4 years of life and may cause lung metastases. Haematuria Causes of haematuria Trauma Injury to renal tract Renal trauma commonly due to blunt injury (others penetrating injuries) Ureter trauma rare: iatrogenic Bladder trauma: due to RTA or pelvic fractures Infection Remember TB Malignancy Renal cell carcinoma (remember paraneoplastic syndromes): painful or painless Urothelial malignancies: 90% are transitional cell carcinoma, can occur anywhere along the urinary tract. Painless haematuria. Squamous cell carcinoma and adenocarcinoma: rare bladder tumours Prostate cancer Penile cancers: SCC Renal disease Glomerulonephritis Stones Microscopic haematuria common Structural abnormalities Benign prostatic hyperplasia (BPH) causes haematuria due to hypervascularity of the prostate gland Cystic renal lesions e.g. polycystic kidney disease Vascular malformations Renal vein thrombosis due to renal cell carcinoma Coagulopathy Causes bleeding of underlying lesions Drugs Cause tubular necrosis or interstitial nephritis: aminoglycosides, chemotherapy Interstitial nephritis: penicillin, sulphonamides, and NSAIDs Anticoagulants Benign Exercise Gynaecological Endometriosis: flank pain, dysuria, and haematuria that is cyclical Iatrogenic Catheterisation Radiotherapy; cystitis, severe haemorrhage, bladder necrosis Pseudohaematuria For example following consumption of beetroot References Http://bestpractice.bmj.com/best-practice/monograph/316/overview/aetiology.html

Answer 1681

Seborrhoeic keratosis may have a number of appearances. However, the scaly, thick, greasy surface with scattered keratin plugs makes this the most likely diagnosis. Benign skin diseases Seborrhoeic keratosis Most commonly arise in patients over the age of 50 years, often idiopathic Equal sex incidence and prevalence Usually multiple lesions over face and trunk Flat, raised, filiform and pedunculated subtypes are recognised Variable colours and surface may have greasy scale overlying it Treatment options consist of leaving alone or simple shave excision Melanocytic naevi Congenital melanocytic naevi Typically appear at, or soon after, birth Usually greater than 1cm diameter Increased risk of malignant transformation (increased risk greatest for large lesions) Junctional melanocytic naevi Circular macules May have heterogeneous colour even within same lesion Most naevi of the palms, soles and mucous membranes are of this type Compound naevi Domed pigmented nodules up to 1cm in diameter Arise from junctional naevi, usually have uniform colour and are smooth Spitz naevus Usually develop over a few months in children May be pink or red in colour, most common on face and legs May grow up to 1cm and growth can be rapid, this usually results in excision Atypical naevus syndrome Atypical melanocytic naevi that may be autosomally dominantly inherited Some individuals are at increased risk of melanoma (usually have mutations of CDKN2A gene) Many people with atypical naevus syndrome AND a parent sibling with melanoma will develop melanoma Epidermoid cysts Common and affect face and trunk They have a central punctum, they may contain small quantities of sebum The cyst lining is either normal epidermis (epidermoid cyst) or outer root sheath of hair follicle (pilar cyst) Dermatofibroma Solitary dermal nodules Usually affect extremities of young adults Lesions feel larger than they appear visually Histologically they consist of proliferating fibroblasts merging with sparsely cellular dermal tissues Painful skin lesions Eccrine spiradenoma Neuroma Glomus tumour Leiomyoma Angiolipoma Neurofibroma (rarely painful) and dermatofibroma (rarely painful)

Answer 1682

A left sided varicocele is a recognised presenting sign of a renal tumour occluding the renal vein (into which the left testicular vein drains). An abdominal ultrasound should be undertaken to exclude this. Surgery for uncomplicated varicocele is usually unnecessary. Renal tumours Renal cell carcinoma Renal cell carcinoma is an adenocarcinoma of the renal cortex and is believed to arise from the proximal convoluted tubule. They are usually solid lesions, up to 20% may be multifocal, 20% may be calcified and 20% may have either a cystic component or be wholly cystic. They are often circumscribed by a pseudocapsule of compressed normal renal tissue. Spread may occur either by direct extension into the adrenal gland, renal vein or surrounding fascia. More distant disease usually occurs via the haematogenous route to lung, bone or brain. Renal cell carcinoma comprise up to 85% of all renal malignancies. Males are more commonly affected than females and sporadic tumours typically affect patients in their sixth decade. Patients may present with a variety of symptoms including; haematuria (50%), loin pain (40%), mass (30%) and up to 25% may have symptoms of metastasis.Less than 10% have the classic triad of haematuria, pain and mass. Investigation Many cases will present as haematuria and be discovered during diagnostic work up. Benign renal tumours are rare, so renal masses should be investigated with multislice CT scanning. Most tumours are also characterised with an arterial phase CT, particularly if they may be suitable for partial nephrectomy. CT scanning of the chest and abdomen to detect distant disease should also be undertaken. Routine bone scanning is not indicated in the absence of symptoms. Biopsy should not be performed when a nephrectomy is planned but is mandatory before any ablative therapies are undertaken. Assessment of the functioning of the contra lateral kidney. Management T1 lesions may be managed by partial nephrectomy and this gives equivalent oncological results to total radical nephrectomy. Partial nephrectomy may also be performed when there is inadequate reserve in the remaining kidney. Ablative techniques may also be considered for small T1 lesions in unfit patients. In general, outcomes are less favorable than with surgical resection. For T2 lesions and above a radical nephrectomy is standard practice and this may be performed via a laparoscopic or open approach. Preoperative embolisation is not indicated nor is resection of uninvolved adrenal glands. During surgery early venous control is mandatory to avoid shedding of tumour cells into the circulation. Patients with completely resected disease do not benefit from adjuvant therapy with either chemotherapy or biological agents. These should not be administered outside the setting of clinical trials. Patients with transitional cell cancer will require a nephroureterectomy with disconnection of the ureter at the bladder. References Capitanio U, Montorsi F. Renal cancer. Lancet. 2016 Feb 27;387(10021):894-906. Capitanio U et al. Epidemiology of Renal Cell Carcinoma. Eur Urol. 2019 Jan;75(1):74-84.

Answer 1683

Beta blockers should not be stopped acutely prior to surgery as there may be a rebound effect associated with increased complications. Brain natriuretic peptide is a neurohormone synthesized in the cardiac ventricles. Levels have been used to assess prognosis in heart failure and acute coronary syndromes. Preoperative elevated brain natriuretic peptide levels identify patients undergoing non cardiac surgery at high risk of cardiac mortality and all cause mortality. All patients with peripheral vascular disease should take statins prior to vascular surgery as studies have shown a 50% risk reduction and a reduction in perioperative cardiac events. Reference 1. Dernellis J, Panaretou M. Assessment of cardiac risk before non-cardiac surgery: brain natriuretic peptide in 1590 patients. Heart 2006;92:1645-1650 2. Poldermans, D et al Fluvastatin and Perioperative Events in Patients Undergoing Vascular Surgery. NEJM 2009; 361:980-989 Proactive care of older people undergoing surgery (POPS) Comprehensive geriatric assessment MDT assessment preoperatively Main predictors of complications are co-morbidities cardiac disease and reduced functional capacity - preoperative assessment is the key to preventing adverse postoperative outcomes Patients screened for risk factors (albumin <30, co morbidities) Management plan made and disseminated to all involved Patients education: pain relief, post op exercises, nutrition Outcomes: Fewer postoperative medical complications Reduced length of stay by 4.5 days References Proactive care of older people undergoing surgery (POPS) Danielle Harari et al. Age and Ageing 2007 36(2):190-196

Answer 1684

Femoral access catheters are typically inserted in the region of the femoral triangle. Therefore the physician may encounter the femoral, vein, nerve, branches of the femoral artery and tributaries of the femoral vein. The deep circumflex iliac artery arises above the inguinal ligament and is therefore less likely to be encountered than the superficial circumflex iliac artery which arises below the inguinal ligament. Femoral triangle anatomy Boundaries Superiorly Inguinal ligament Laterally Sartorius Medially Adductor longus Floor Iliopsoas, adductor longus and pectineus Roof Fascia lata and Superficial fascia Superficial inguinal lymph nodes (palpable below the inguinal ligament) Long saphenous vein Contents Femoral vein (medial to lateral) Femoral artery-pulse palpated at the mid inguinal point Femoral nerve Deep and superficial inguinal lymph nodes Lateral cutaneous nerve Great saphenous vein Femoral branch of the genitofemoral nerve

Answer 1685

The external oblique aponeurosis forms the anterior wall of the inguinal canal and also the lateral edge of the superficial inguinal ring. The rectus abdominis lies posteromedially and the transversalis posterior to this. Inguinal canal Location Above the inguinal ligament The inguinal canal is 4cm long The superficial ring is located anterior to the pubic tubercle The deep ring is located approximately 1.5-2cm above the half way point between the anterior superior iliac spine and the pubic tubercle Boundaries of the inguinal canal Floor External oblique aponeurosis Inguinal ligament Lacunar ligament Roof Internal oblique Transversus abdominis Anterior wall External oblique aponeurosis Posterior wall Transversalis fascia Conjoint tendon Laterally Internal ring Transversalis fascia Fibres of internal oblique Medially External ring Conjoint tendon Contents Males Spermatic cord and ilioinguinal nerve As it passes through the canal the spermatic cord has 3 coverings: External spermatic fascia from external oblique aponeurosis Cremasteric fascia Internal spermatic fascia Females Round ligament of uterus and ilioinguinal nerve Related anatomy of the inguinal region The boundaries of Hesselbachs triangle are commonly tested and illustrated below:

Answer 1686

The cast is most likely to affect the common peroneal nerve as it wraps around the fibular head. A foot drop is the typical end result of such an injury. Common peroneal nerve Derived from the dorsal divisions of the sacral plexus (L4, L5, S1 and S2). This nerve supplies the skin and fascia of the anterolateral surface of the leg and the dorsum of the foot. It also innervates the muscles of the anterior and peroneal compartments of the leg, extensor digitorum brevis as well as the knee, ankle and foot joints. It is laterally placed within the sciatic nerve. From the bifurcation of the sciatic nerve it passes inferolaterally in the lateral and proximal part of the popliteal fossa, under the cover of biceps femoris and its tendon. To reach the posterior aspect of the fibular head. It ends by dividing into the deep and superficial peroneal nerves at the point where it winds around the lateral surface of the neck of the fibula in the body of peroneus longus, approximately 2cm distal to the apex of the head of the fibula. It is palpable posterior to the head of the fibula. Branches In the thigh Nerve to the short head of biceps Articular branch (knee) In the popliteal fossa Lateral cutaneous nerve of the calf Neck of fibula Superficial and deep peroneal nerves

Answer 1687

The cutting monopolar mode is needed, that's why this can be complicated by bleeding. Diathermy - Diathermy devices are used by surgeons in all branches of surgery. Use electric currents to produce local heat and thereby facilitate haemostasis or surgical dissection. Consist of a generator unit that is located outside the patient and can be set to the level of power required by the surgeon. There are two major types of diathermy machine; Monopolar The current flows through the diathermy unit into a handheld device that is controlled by the surgeon. Electricity can flow from the tip of the device into the patient. The earth electrode is located some distance away. The relatively narrow tip of the diathermy device produces local heat and this can be used to vaporise and fulgurate tissues. The current can be adjusted in terms of frequency so that different actions can be effected. In cutting mode sufficient power is applied to the tissues to vaporise their water content. In coagulation mode the power level is reduced so that a coagulum is formed instead. Some diathermy machines can utilise a setting known as blend that alternates cutting and coagulation functions, these tend to be used during procedures such as colonoscopic polypectomy. Bipolar The electric current flows from one electrode to another however, both electrodes are usually contained within the same device e.g. a pair of forceps. The result is that heating is localised to the area between the two electrodes and surrounding tissue damage is minimised. Ultrasound based devices These include CUSA and Harmonic scalpel. They generate high frequency oscillations that seal and coagulate tissues. They have different energy settings that allow them to dissect and simultaneously seal vessels if required. The CUSA device leaves vessels intact that may then be divided. Ligasure device Delivers tailored energy levels to allow simultaneous haemostasis and dissection. The device senses the impedance of the tissues and tailors energy levels accordingly. Hazards of diathermy Inadvertent patient burn. This may result of careless handling of the device or in the case of monopolar devices forgetting to apply a return electrode plate, In this situation patients may develop a contact burn when electricity flows to earth Explosion or fire. This may occur when volatile anaesthetic gases or skin preparation fluid have been used

Answer 1688

Rectal involvement with diverticular disease almost never occurs. Because the rectum has a longitudinal muscle coat (blending of the tenia marks the recto-sigmoid junction), diverticular disease almost never occurs here. Right sided colonic diverticular disease is well recognised (though less common than left sided). Diverticular disease Diverticular disease is a common surgical problem. It consists of herniation of colonic mucosa through the muscular wall of the colon. The usual site is between the taenia coli where vessels pierce the muscle to supply the mucosa. For this reason, the rectum, which lacks taenia, is often spared. Symptoms Altered bowel habit Bleeding Abdominal pain Complications Diverticulitis Haemorrhage Development of fistula Perforation and faecal peritonitis Perforation and development of abscess Development of diverticular phlegmon Diagnosis Patients presenting in clinic will typically undergo either a colonoscopy, CT cologram or barium enema as part of their diagnostic work up. All tests can identify diverticular disease. It can be far more difficult to confidently exclude cancer, particularly in diverticular strictures. Acutely unwell surgical patients should be investigated in a systematic way. Plain abdominal films and an erect chest x-ray will identify perforation. An abdominal CT scan (not a CT cologram) with oral and intravenous contrast will help to identify whether acute inflammation is present but also the presence of local complications such as abscess formation. Severity Classification- Hinchey I Para-colonic abscess II Pelvic abscess III Purulent peritonitis IV Faecal peritonitis Treatment Increase dietary fibre intake. Mild attacks of diverticulitis may be managed conservatively with antibiotics. Peri colonic abscesses should be drained either surgically or radiologically. Recurrent episodes of acute diverticulitis requiring hospitalisation are a relative indication for a segmental resection. Hinchey IV perforations (generalised faecal peritonitis) will require a resection and usually a stoma. This group have a very high risk of post operative complications and usually require HDU admission.

Answer 1689

A stent is the best option for biliary decompression in resectable disease. Surgical bypasses have no place in the management of operable malignancy as a bridge to definitive surgery. Pancreatic stents Both benign and malignant biliary obstruction may be treated by placement of stents. These may be either plastic tubes or self expanding metallic stents. They can be placed either percutaneously, at ERCP, or, less commonly now, open surgery. Complications include blockage, displacement and those related to the method of insertion. Metallic Vs Plastic stents Metallic stents Plastic stents Expensive Cheap Embed in surrounding tissues Do not usually embed Displacement rare Displacement common Blockage rare Blockage common

Answer 1690

Ketamine has a moderate to strong analgesic effect. It may be used for emergency procedures outside the hospital environment to induce anaesthesia for procedures such as emergency amputation. Anaesthetic agents The table below summarises some of the more commonly used IV induction agents Agent Specific features Propofol Rapid onset of anaesthesia Pain on IV injection Rapidly metabolised with little accumulation of metabolites Proven anti emetic properties Moderate myocardial depression Widely used especially for maintaining sedation on ITU, total IV anaesthesia and for daycase surgery Sodium thiopentone Extremely rapid onset of action making it the agent of choice for rapid sequence of induction Marked myocardial depression may occur Metabolites build up quickly Unsuitable for maintenance infusion Little analgesic effects Ketamine May be used for induction of anaesthesia Has moderate to strong analgesic properties Produces little myocardial depression making it a suitable agent for anaesthesia in those who are haemodynamically unstable May induce state of dissociative anaesthesia resulting in nightmares Etomidate Has favorable cardiac safety profile with very little haemodynamic instability No analgesic properties Unsuitable for maintaining sedation as prolonged (and even brief) use may result in adrenal suppression Post operative vomiting is common

Answer 1691

Undescended testes are not uncommon in young children. They may be present in 4% of term infants, but only in 1.3% children at 3 months of age. In this scenario the testis is retractile and can be managed expectantly. Cryptorchidism A congenital undescended testis is one that has failed to reach the bottom of the scrotum by 3 months of age. At birth up to 5% of boys will have an undescended testis, post natal descent occurs in most and by 3 months the incidence of cryptorchidism falls to 1-2%. In the vast majority of cases the cause of the maldescent is unknown. A proportion may be associated with other congenital defects including: Patent processus vaginalis Abnormal epididymis Cerebral palsy Developmental delay Wilms tumour Abdominal wall defects (e.g. gastroschisis, prune belly syndrome) Differential diagnosis These include retractile testes and, in the case of absent bilateral testes the possibility of intersex conditions. A retractile testis can be brought into the scrotum by the clinician and when released remains in the scrotum. If the examining clinician notes the testis to return rapidly into the inguinal canal when released then surgery is probably indicated. Reasons for correction of cryptorchidism Reduce risk of infertility Allows the testes to be examined for testicular cancer Avoid testicular torsion Cosmetic appearance Males with undescended testis are 40 times as likely to develop testicular cancer (seminoma) as males without undescended testis The location of the undescended testis affects the relative risk of testicular cancer (50% intra-abdominal testes) Treatment Orchidopexy at 6- 18 months of age. The operation usually consists of inguinal exploration, mobilisation of the testis and implantation into a dartos pouch. Intra-abdominal testis should be evaluated laparoscopically and mobilised. Whether this is a single stage or two stage procedure depends upon the exact location. After the age of 2 years in untreated individuals the Sertoli cells will degrade and those presenting late in teenage years may be better served by orchidectomy than to try and salvage a non functioning testis with an increased risk of malignancy.

Answer 1692

The argon plasma coagulation system is very good for managing splenic bleeding. Alternatives include topical haemostatic agents. Its not necessary to ligate the hilar vessels, if this is required, a splenectomy is the usual outcome. Management of bleeding Bleeding is a process that is encountered in all branches of surgery. The decision as to how best to manage bleeding depends upon the site, vessel and circumstances. Management of superficial dermal bleeding This will usually cease spontaneously. If it is troublesome then direct use of monopolar or bipolar cautery devices will usually control the situation. Scalp wounds are a notable exception and the bleeding from these may be brisk. In this situation the use of mattress sutures as a wound closure method will usually address the problem. Superficial arterial bleeding If the vessel can be safely identified then the easiest method is to apply a haemostatic clip and ligate the vessel. Major arterial bleeding If the vessel can be clearly identified and is accessible then it may be possible to apply a clip and ligate the vessel. If the vessel is located in a pool of blood then blind application of haemostatic clips is highly dangerous and may result in collateral injury. In this situation evacuating the clot and packing the area is often safer. The pack can then be carefully removed when the required instruments are available. Some vessels may retract and bleeding may then be controlled by dissection of surrounding structures or under-running the bleeding point. Major venous bleeding The safest initial course of action is to apply digital pressure to the bleeding point. To control the bleeding the surgeon will need a working suction device. Divided veins may require ligation. Incomplete lacerations of major veins (e.g. IVC) are best repaired. In order to do this it is safest to apply a Satinsky type vascular clamp and repair the defect with 5/0 prolene. Bleeding from raw surfaces This may be mixed bleeding and can be troublesome. Spray diathermy and argon plasma coagulation are both useful agents. Certain topical haemostatic agents such as surgicell are useful in encouraging clot formation and may be used in conjunction with, or instead of, the above agents.

Answer 1693

The systemic features in the history are strongly suggestive of inflammatory bowel disease rather than the other causes. Colorectal cancer is almost unheard of at this age. Paediatric proctology Children may present with altered bowel habit and/ or rectal bleeding. Classical haemorroidal disease is relatively rare in children. Painful bright red rectal bleeding is much more common since constipation is a relatively common childhood disorder. The hard stool causes a tear of the ano-rectal mucosa with subsequent fissure. The pain from the fissure must be addressed promptly or the child will delay defecation and this fissure will worsen. Inflammatory bowel disease may present in a similar pattern in paediatric practice with altered bowel habit (usually diarrhoea) and bleeding. Systemic features may be present and investigation with an endoscopy may be required. Children with intussceception usually present at a relatively young age and the history is usually one of colicky abdominal pain, together with a mass on clinical examination.The often cited red current jelly type stool is a rare but classical feature. Juvenile polyps may occur as part of the familial polyposis coli syndromes. The lesions, which are hamartomas, are often cherry red if they protrude externally.

Answer 1694

Rapid intravascular haemolysis leading to shock, DIC and death can occur with this reaction. Blood transfusion reactions Acute transfusion reactions present as adverse signs or symptoms during or within 24 hours of a blood transfusion. The most frequent reactions are fever, chills, pruritus, or urticaria, which typically resolve promptly without specific treatment or complications. Other signs occurring in temporal relationship with a blood transfusion, such as severe dyspnoea, pyrexia, or loss of consciousness may be the first indication of a more severe potentially fatal reaction. The causes of adverse reactions are multi-factorial. Immune mediated reactions, some of the most feared, occur as a result of component mismatch, the commonest cause of which is clerical error. More common, non immune mediated, complications may occur as a result of product contamination, this may be bacterial or viral. Transfusion related lung injury is well recognised and there are two proposed mechanisms which underpin this. One involves the sequestration of primed neutrophils within the recipient pulmonary capillary bed. The other proposed mechanism suggests that HLA mismatches between donor neutrophils and recipient lung tissue is to blame. The table below summarises the main types of transfusion reaction. Immune mediated Non immune mediated Pyrexia Hypocalcaemia Alloimmunization CCF Thrombocytopaenia Infections Transfusion associated lung injury Hyperkalaemia Graft vs Host disease Urticaria Acute or delayed haemolysis ABO incompatibility Rhesus incompatibility

Answer 1695

Inflammatory, obliterative arteritis affecting aorta and branches Females> Males Symptoms may include upper limb claudication Clinical findings include diminished or absent pulses ESR often affected during the acute phase akayasu's arteritis Takayasu's arteritis is a large vessel vasculitis. It typically causes occlusion of the aorta and questions commonly refer to an absent limb pulse. It is more common in females and Asian people Associations renal artery stenosis Management steroids

Answer 1696

Probing fistulae during acute sepsis is associated with a high complication rate and should not be undertaken routinely. Fistulas A fistula is defined as an abnormal connection between two epithelial surfaces. There are many types ranging from Branchial fistulae in the neck to entero-cutaneous fistulae abdominally. In general surgical practice the abdominal cavity generates the majority and most of these arise from diverticular disease and Crohn's. As a general rule all fistulae will resolve spontaneously as long as there is no distal obstruction. This is particularly true of intestinal fistulae. The four types of fistulae are: Enterocutaneous These link the intestine to the skin. They may be high (>500ml) or low output (<250ml) depending upon source. Duodenal /jejunal fistulae will tend to produce high volume, electrolyte rich secretions which can lead to severe excoriation of the skin. Colo-cutaneous fistulae will tend to leak faeculent material. Both fistulae may result from the spontaneous rupture of an abscess cavity onto the skin (such as following perianal abscess drainage) or may occur as a result of iatrogenic input. In some cases it may even be surgically desirable e.g. mucous fistula following sub total colectomy for colitis. Suspect if there is excess fluid in the drain. Enteroenteric or Enterocolic This is a fistula that involves the large or small intestine. They may originate in a similar manner to enterocutaneous fistulae. A particular problem with this fistula type is that bacterial overgrowth may precipitate malabsorption syndromes. This may be particularly serious in inflammatory bowel disease. Enterovaginal Aetiology as above. Enterovesical This type of fistula goes to the bladder. These fistulas may result in frequent urinary tract infections, or the passage of gas from the urethra during urination. Management Some rules relating to fistula management: They will heal provided there is no underlying inflammatory bowel disease and no distal obstruction, so conservative measures may be the best option Where there is skin involvement, protect the overlying skin, often using a well fitted stoma bag- skin damage is difficult to treat A high output fistula may be rendered more easily managed by the use of octreotide, this will tend to reduce the volume of pancreatic secretions. Nutritional complications are common especially with high fistula (e.g. high jejunal or duodenal) these may necessitate the use of TPN to provide nutritional support together with the concomitant use of octreotide to reduce volume and protect skin. When managing perianal fistulae surgeons should avoid probing the fistula where acute inflammation is present, this almost always worsens outcomes. When perianal fistulae occur secondary to Crohn's disease the best management option is often to drain acute sepsis and maintain that drainage through the judicious use of setons whilst medical management is implemented. Always attempt to delineate the fistula anatomy, for abscesses and fistulae that have an intra abdominal source the use of barium and CT studies should show a track. For perianal fistulae surgeons should recall Goodsall's rule in relation to internal and external openings.

Answer 1697

Local anaesthetics: avoid use of adrenaline in extremities This is excision of the toe nail and a fast acting local anaesthetic is indicated. Whilst use of adrenaline in digits is now sometimes done, there is little additional benefit in this case. Local anaesthetic agents Lidocaine An amide Local anaesthetic and a less commonly used antiarrhythmic (affects Na channels in the axon) Hepatic metabolism, protein bound, renally excreted Toxicity: due to IV or excess administration. Increased risk if liver dysfunction or low protein states. Note acidosis causes lidocaine to detach from protein binding. Drug interactions: Beta blockers, ciprofloxacin, phenytoin Features of toxicity: Initial CNS over activity then depression as lidocaine initially blocks inhibitory pathways then blocks both inhibitory and activating pathways. Cardiac arrhythmias. Increased doses may be used when combined with adrenaline to limit systemic absorption. Cocaine Pure cocaine is a salt, usually cocaine hydrochloride. It is supplied for local anaesthetic purposes as a paste. It is supplied for clinical use in concentrations of 4 and 10%. It may be applied topically to the nasal mucosa. It has a rapid onset of action and has the additional advantage of causing marked vasoconstriction. It is lipophillic and will readily cross the blood brain barrier. Its systemic effects also include cardiac arrhythmias and tachycardia. Apart from its limited use in ENT surgery it is otherwise used rarely in mainstream surgical practice. Bupivacaine Bupivacaine binds to the intracellular portion of sodium channels and blocks sodium influx into nerve cells, which prevents depolarization. It has a much longer duration of action than lignocaine and this is of use in that it may be used for topical wound infiltration at the conclusion of surgical procedures with long duration analgesic effect. It is cardiotoxic and is therefore contra indicated in regional blockage in case the tourniquet fails. Levobupivacaine (Chirocaine) is less cardiotoxic and causes less vasodilation. Prilocaine Similar mechanism of action to other local anaesthetic agents. However, it is far less cardiotoxic and is therefore the agent of choice for intravenous regional anaesthesia e.g. Biers Block. All local anaesthetic agents dissociate in tissues and this contributes to their therapeutic effect. The dissociation constant shifts in tissues that are acidic e.g. where an abscess is present, and this reduces the efficacy. Doses of local anaesthetics Agent Dose plain Dose with adrenaline Lignocaine 3mg/Kg 7mg/Kg Bupivacaine 2mg/Kg 2mg/Kg Prilocaine 6mg/Kg 9mg/Kg These are a guide only as actual doses depend on site of administration, tissue vascularity and co-morbidities. Maximum total local anaesthetic doses Lignocaine 1% plain - 3mg/ Kg - 200mg (20ml) Lignocaine 1% with 1 in 200,000 adrenaline - 7mg/Kg - 500mg (50ml) Bupivacaine 0.5% - 2mg/kg- 150mg (30ml) Maximum doses are based on ideal body weight Effects of adrenaline Adrenaline may be added to local anaesthetic drugs. It prolongs the duration of action at the site of injection and permits usage of higher doses (see above). It is contra indicated in patients taking MAOI's or tricyclic antidepressants. The toxicity of bupivacaine is related to protein binding and addition of adrenaline to this drug does not permit increases in the total dose of bupivacaine, in contrast to the situation with lignocaine. References An excellent review is provided by: French J and Sharp L. Local Anaesthetics. Ann R Coll Surg Engl 2012; 94: 76-80.

Answer 1698

Punch biopsies are a useful option for obtaining a full thickness tissues sample with minimal tissue disruption. In this situation, the other differential would be AIN or VIN and punch biopsies would be useful in distinguishing these. Skin Diseases Skin lesions may be referred for surgical assessment, but more commonly will come via a dermatologist for definitive surgical management. Skin malignancies include basal cell carcinoma, squamous cell carcinoma and malignant melanoma. Basal Cell Carcinoma Most common form of skin cancer. Commonly occur on sun exposed sites apart from the ear. Sub types include nodular, morphoeic, superficial and pigmented. Typically slow growing with low metastatic potential. Standard surgical excision, topical chemotherapy and radiotherapy are all successful. As a minimum a diagnostic punch biopsy should be taken if treatment other than standard surgical excision is planned. Squamous Cell Carcinoma Again related to sun exposure. May arise in pre - existing solar keratoses. May metastasize if left. Immunosupression (e.g. following transplant), increases risk. Wide local excision is the treatment of choice and where a diagnostic excision biopsy has demonstrated SCC, repeat surgery to gain adequate margins may be required. Malignant Melanoma The main diagnostic features (major criteria): Change in size Change in shape Change in colour Secondary features (minor criteria) Diameter >6mm Inflammation Oozing or bleeding Altered sensation Treatment Suspicious lesions should undergo excision biopsy. The lesion should be removed completely as incision biopsy can make subsequent histopathological assessment difficult. Once the diagnosis is confirmed the pathology report should be reviewed to determine whether further re-excision of margins is required (see below): Margins of excision-Related to Breslow thickness Lesions 0-1mm thick 1cm Lesions 1-2mm thick 1- 2cm (Depending upon site and pathological features) Lesions 2-4mm thick 2-3 cm (Depending upon site and pathological features) Lesions >4 mm thick 3cm Marsden J et al. Revised UK guidelines for management of Melanoma. Br J Dermatol 2010 163:238-256. Further treatments such as sentinel lymph node mapping, isolated limb perfusion and block dissection of regional lymph node groups should be selectively applied. Kaposi Sarcoma Tumour of vascular and lymphatic endothelium. Purple cutaneous nodules. Associated with immuno supression. Classical form affects elderly males and is slow growing. Immunosupression form is much more aggressive and tends to affect those with HIV related disease. Non malignant skin disease Dermatitis Herpetiformis Chronic itchy clusters of blisters. Linked to underlying gluten enteropathy (coeliac disease). Dermatofibroma Benign lesion. Firm elevated nodules. Usually history of trauma. Lesion consists of histiocytes, blood vessels and fibrotic changes. Pyogenic granuloma Overgrowth of blood vessels. Red nodules. Usually follow trauma. May mimic amelanotic melanoma. Acanthosis nigricans Brown to black, poorly defined, velvety hyperpigmentation of the skin. Usually found in body folds such as the posterior and lateral folds of the neck, the axilla, groin, umbilicus, forehead, and other areas. The most common cause of acanthosis nigricans is insulin resistance, which leads to increased circulating insulin levels. Insulin spillover into the skin results in its abnormal increase in growth (hyperplasia of the skin). In the context of a malignant disease, acanthosis nigricans is a paraneoplastic syndrome and is then commonly referred to as acanthosis nigricans maligna. Involvement of mucous membranes is rare and suggests a coexisting malignant condition.

Answer 1699

Short segment disease and good run off with tissue loss is a compelling indication for angioplasty. He should receive aspirin and a statin if not already taking them. Peripheral vascular disease Indications for surgery to revascularise the lower limb Intermittent claudication Critical ischaemia Ulceration Gangrene Intermittent claudication that is not disabling may provide a relative indication, whilst the other complaints are often absolute indications depending upon the frailty of the patient. Assessment Clinical examination Ankle brachial pressure index measurement Duplex arterial ultrasound Angiography (standard, CT or MRI): usually performed only if intervention being considered. Angioplasty In order for angioplasty to be undertaken successfully the artery has to be accessible. The lesion relatively short and reasonable distal vessel runoff. Longer lesions may be amenable to sub-intimal angioplasty. Surgery Surgery will be undertaken where attempts at angioplasty have either failed or are unsuitable. Bypass essentially involves bypassing the affected arterial segment by utilising a graft to run from above the disease to below the disease. As with angioplasty good runoff improves the outcome. Some key concepts with bypass surgery Superficial femoral artery occlusion to the above knee popliteal In the ideal scenario, vein (either in situ or reversed LSV) would be used as a conduit. However, prosthetic material has reasonable 5 year patency rates and some would advocate using this in preference to vein so that vein can be used for other procedures in the future. In general terms either technique is usually associated with an excellent outcome (if run off satisfactory). Procedure Artery dissected out, IV heparin 3,000 units given and then the vessels are cross clamped Longitudinal arteriotomy Graft cut to size and tunneled to arteriotomy sites Anastomosis to femoral artery usually with 5/0 'double ended' Prolene suture Distal anastomosis usually using 6/0 'double ended' Prolene Distal disease Femoro-distal bypass surgery takes longer to perform, is more technically challenging and has higher failure rates. In elderly diabetic patients with poor runoff a primary amputation may well be a safer and more effective option. There is no point in embarking on this type of surgery in patients who are wheelchair bound. In femorodistal bypasses vein gives superior outcomes to PTFE. Rules Vein mapping 1st to see whether there is suitable vein (the preferred conduit). Sub intimal hyperplasia occurs early when PTFE is used for the distal anastomosis and will lead to early graft occlusion and failure. Essential operative procedure as for above knee fem-pop. If there is insufficient vein for the entire conduit then vein can be attached to the end of the PTFE graft and then used for the distal anastomosis. This type of 'vein boot' is technically referred to as a Miller Cuff and is associated with better patency rates than PTFE alone. Remember the more distal the arterial anastomosis the lower the success rate. References Peach G et al. Diagnosis and management of peripheral arterial disease. BMJ 2012; 345: 36-41.

Answer 1700

In compartment syndrome the loss of pulses is a very late sign indeed and only seen when compartment pressure exceeds arterial pressure Circumferential burns may constrict the limb and cause a compartment syndrome to develop. Eshcarotomy is required, and compartmental decompression. Burns Burns may be thermal, chemical or electrical. In the former category are burns which occur as a result of heat. Chemical burns occur when the skin is exposed to an extremely caustic or alkaline substance. Electrical burns occur following exposure to electrical current. The immediate management includes removal of the burning source which usually includes irrigation of the burned area. A detailed assessment then needs to be made of the extent of the burns and a number of charts are available for recording this information. The degree of injury relates to the temperature and duration of exposure. Most domestic burns are mainly scalds in young children. Following the burn, there is a local response with progressive tissue loss and release of inflammatory cytokines. Systemically, there are cardiovascular effects resulting from fluid loss and sequestration of fluid into the third space. There is a marked catabolic response. Immunosuppression is common with large burns and bacterial translocation from the gut lumen is a recognised event. Sepsis is a common cause of death following major burns. Types of burn Type of burn Skin layers affected Skin appearance Blanching Management Epidermal/Superficial Epidermis Red, moist Yes Superficial partial thickness Epidermis and part of papillary dermis affected Pale, dry Yes Normally heals with no intervention Deep partial thickness Epidermis, whole papillary dermis affected Mottled red colour No Needs surgical intervention (depending on site) Full thickness Whole skin layer and subcutaneous tissue affected Dry, leathery hard wound No Burns centre Depth of burn assessment Bleeding on needle prick Sensation Appearance Blanching to pressure Percentage burn estimation Lund Browder chart: most accurate even in children Wallace rule of nines Palmar surface: surface area palm = 0.8% burn >15% body surface area burns in adults needs urgent burn fluid resuscitation Transfer to burn centre if: Need burn shock resuscitation Face/hands/genitals affected Deep partial thickness or full thickness burns Significant electrical/chemical burns Management The initial aim is to stop the burning process and resuscitate the patient. Intravenous fluids will be required for children with burns greater than 10% of total body surface area. Adults with burns greater than 15% of total body surface area will also require IV fluids. The fluids are calculated using the Parkland formula which is; volume of fluid= total body surface area of the burn % x weight (Kg) x2-4 (preference for lower amount i.e. 2ml to avoid excessive fluid overload). Half of the fluid is administered in the first 8 hours. A urinary catheter should be inserted. Analgesia should be given. Complex burns, burns involving the hand perineum and face and burns >10% in adults and >5% in children should be transferred to a burns unit. Circumferential burns affecting a limb or severe torso burns impeding respiration may require escharotomy to divide the burnt tissue. Conservative management is appropriate for superficial burns and mixed superficial burns that will heal in 2 weeks. More complex burns may require excision and skin grafting. Excision and primary closure is not generally practised as there is a high risk of infection. There is no evidence to support the use of anti microbial prophylaxis or topical antibiotics in burn patients. Escharotomies Indicated in circumferential full thickness burns to the torso or limbs. Careful division of the encasing band of burn tissue will potentially improve ventilation (if the burn involves the torso), or relieve compartment syndrome and oedema (where a limb is involved) References www.euroburn.org/e107files/downloads/guidelinesburncare.pdf Barajas-Nava LA, LÃ³pez-Alcalde J, RoquÃ© i Figuls M, SolÃ I, Bonfill Cosp X. Antibiotic prophylaxis for preventing burn wound infection. Cochrane Database of Systematic Reviews 2013, Issue 6. Art. No.: CD008738. DOI: 10.1002/14651858.CD008738.pub2. Hettiaratchy S & Papini R. Initial management of a major burn: assessment and resuscitation. BMJ 2004;329:101-103

Answer 1701

Mnemonic branches off the posterior cord S ubscapular (upper and lower) T horacodorsal A xillary R adial The musculocutaneous nerve is a branch off the lateral cord. Brachial plexus The brachial plexus extends from the neck to the axilla. It is formed by the ventral rami of the fifth to the eighth cervical nerves with the ascending part of the first thoracic nerve. Location of the plexus The ventral rami which form the plexus enter the lower part of the posterior triangle of the neck in series with the ventral rami of the cervical plexus. The second part of the subclavian artery lies immediately anterior to the lower two rami. The upper three rami intermingle and pass inferolaterally towards the axilla and subclavian artery. They are enclosed within an extension of the prevertebral fascia. In the neck the plexus lies deep to platysma, the supraclavicular nerves, inferior belly of omohyoid and the transverse cervical artery. It then passes deep to the clavicle and the suprascapular vessels, to enter the axilla, and thence surround the second part of the axillary artery Composition of the plexus Ventral rami, the roots of the plexus, lie between scalenus medius and anterior. As they enter the posterior triangle, the upper two (C5,6) and lower two (C8, T1) roots of the plexus unite to form the upper and lower trunks of the plexus respectively. Meanwhile, C7 continues as the middle trunk. The lower trunk may groove the superior surface of the first rib posterior to the subclavian artery, and the root from the first ventral ramus is always in contact with it. Each trunk divides into ventral and dorsal divisions which are destined to supply the anterior (flexor) and posterior (extensor) parts of the upper limb. The cords of the plexus are formed in the axilla. The dorsal divisions unite to form the posterior cord (C5-8). The ventral divisions of the upper and middle trunks unite to form the lateral cord (C5-7), while the ventral divisions of the lower trunk continues as the medial cord (C8-T1). The cords are named according to their relationship to the axillary artery. Each cord terminates by dividing into two main branches at the beginning of the third part of the artery. Sympathetic communications The fifth and sixth cervical ventral rami receive grey rami communicantes from the middle cervical ganglion, while the two or more grey rami communicantes pass from the inferior cervical ganglion to the seventh and eighth cervical ventral rami. The first thoracic ventral ramus receives its grey ramus from the cervicothoracic ganglion. Its for this reason that inferior plexus injury can be complicated by a Horners syndrome. Summary Origin Anterior rami of C5 to T1 Sections of the plexus Roots, trunks, divisions, cords, branches Mnemonic:Real Teenagers Drink Cold Beer Roots Located in the posterior triangle Pass between scalenus anterior and medius Trunks Located posterior to middle third of clavicle Upper and middle trunks related superiorly to the subclavian artery Lower trunk passes over 1st rib posterior to the subclavian artery Divisions Apex of axilla Cords Related to axillary artery

Answer 1702

Ki 67 is a nuclear proliferation marker (used in immunohistochemistry). Although, Ki67 positivity is a marker of malignancy, it is not itself, an oncogene. Oncogenes Oncogenes are cancer promoting genes that are derived from normal genes (proto-oncogenes). Proto-oncogenes play an important physiological role in cellular growth. They are implicated in the development of up to 20% of human cancers. Proto-oncogenes may become oncogenes via the following processes: Mutation (point mutation) Chromosomal translocation Increased protein expression Only one mutated copy of the gene is needed for cancer to occur - a dominant effect Classification of oncogenes Growth factors e.g. Sis Transcription factors e.g. Myc Receptor tyrosine kinase e.g. RET Cytoplasmic tyrosine kinase e.g. Src Regulatory GTPases e.g. Ras Tumour suppressor genes Tumour suppressor genes restrict or repress cellular proliferation in normal cells. Their inactivation through mutation or germ line incorporation is implicated in renal, colonic, breast, bladder and many other cancers. One of the best known tumour suppressor genes is p53. p53 gene offers protection by causing apoptosis of damaged cells. Other well known genes include BRCA 1 and 2.

Answer 1703

A combination of nipple discharge, gynaecomastia and poor vision may well be associated with a prolactinoma. The poor vision results from compression of the optic chiasm resulting in bi temporal hemianopia. Gynaecomastia Gynaecomastia describes an abnormal amount of breast tissue in males and is usually caused by an increased oestrogen:androgen ratio. It is important to differentiate the causes of galactorrhoea (due to the actions of prolactin on breast tissue) from those of gynaecomastia Causes of gynaecomastia physiological: normal in puberty syndromes with androgen deficiency: Kallman's, Klinefelter's testicular failure: e.g. Mumps liver disease testicular cancer e.g. Seminoma secreting HCG ectopic tumour secretion hyperthyroidism haemodialysis drugs: see below Drug causes of gynaecomastia spironolactone (most common drug cause) cimetidine digoxin cannabis finasteride oestrogens, anabolic steroids Very rare drug causes of gynaecomastia tricyclics isoniazid calcium channel blockers heroin busulfan methyldopa Treatment options identify and manage any overt underlying cause liposuction provides the best cosmetic outcome

Answer 1704

Tibialis anterior tendon passes anterior to the medial malleolus. Lateral malleolus Structures posterior to the lateral malleolus and superficial to superior peroneal retinaculum Sural nerve Short saphenous vein Structures posterior to the lateral malleolus and deep to superior peroneal retinaculum Peroneus longus tendon Peroneus brevis tendon The calcaneofibular ligament is attached at the lateral malleolus

Answer 1705

Calcification is likely to be Psammoma body seen in papillary lesions. Thyroid malignancy Papillary carcinoma Commonest sub-type Accurately diagnosed on fine needle aspiration cytology Histologically, they may demonstrate psammoma bodies (areas of calcification) and so called 'orphan Annie' nuclei They typically metastasise via the lymphatics and thus laterally located apparently ectopic thyroid tissue is usually a metastasis from a well differentiated papillary carcinoma Follicular carcinoma Are less common than papillary lesions Like papillary tumours, they may present as a discrete nodule. Although they appear to be well encapsulated macroscopically there is invasion on microscopic evaluation Lymph node metastases are uncommon and these tumours tend to spread haematogenously. This translates into a higher mortality rate Follicular lesions cannot be accurately diagnosed on fine needle aspiration cytology and thus all follicular FNA's (THY 3f) will require at least a hemi thyroidectomy Anaplastic carcinoma Less common and tend to occur in elderly females Disease is usually advanced at presentation and often only palliative decompression and radiotherapy can be offered. Medullary carcinoma These are tumours of the parafollicular cells ( C Cells) and are of neural crest origin. The serum calcitonin may be elevated which is of use when monitoring for recurrence. They may be familial and occur as part of the MEN -2A disease spectrum. Spread may be either lymphatic or haematogenous and as these tumours are not derived primarily from thyroid cells they are not responsive to radioiodine. Lymphoma These respond well to combined chemoradiotherapy Radical surgery is unnecessary once the disease has been diagnosed on biopsy material. Such biopsy material is not generated by an FNA and thus a core biopsy has to be obtained (with care!).

Answer 1706

The median sacral artery leaves the aorta a little above its bifurcation. It descends in the midline anterior to L4 and L5. Abdominal aortic branches Branches Level Paired Type Inferior phrenic T12 (Upper border) Yes Parietal Coeliac T12 No Visceral Superior mesenteric L1 No Visceral Middle suprarenal L1 Yes Visceral Renal L1-L2 Yes Visceral Gonadal L2 Yes Visceral Lumbar L1-L4 Yes Parietal Inferior mesenteric L3 No Visceral Median sacral L4 No Parietal Common iliac L4 Yes Terminal

Answer 1707

Hernia containing Meckels diverticulum is termed a Littres hernia. Hernia Hernias occur when a viscus or part of it protrudes from within its normal anatomical cavity. Specific hernias are covered under their designated titles the remainder are addressed here. Spigelian hernia Interparietal hernia occurring at the level of the arcuate line Rare May lie beneath internal oblique muscle. Usually between internal and external oblique Equal sex distribution Position is lateral to rectus abdominis Both open and laparoscopic repair are possible, the former in cases of strangulation Lumbar hernia The lumbar triangle (through which these may occur) is bounded by: Crest of ilium (inferiorly) External oblique (laterally) Latissimus dorsi (medially) Primary lumbar herniae are rare, most are incisional hernias following renal surgery - Direct anatomical repair with or without mesh re-enforcement is the procedure of choice Obturator hernia Herniation through the obturator canal Commoner in females Usually lies behind pectineus muscle Elective diagnosis is unusual most will present acutely with obstruction When presenting acutely most cases with require laparotomy or laparoscopy (and small bowel resection if indicated) Richters hernia Condition in which part of the wall of the small bowel (usually the anti mesenteric border) is strangulated within a hernia (of any type) They do not present with typical features of intestinal obstruction as lumenal patency is preserved Where vomiting is prominent it usually occurs as a result of paralytic ileus from peritonitis (as these hernias may perforate) Incisional hernia Occur through sites of surgical access into the abdominal cavity Most common following surgical wound infection To minimise following midline laparotomy Jenkins Rule should be followed and this necessitates a suture length 4x length of incision with bites taken at 1cm intervals, 1 cm from the wound edge Repair may be performed either at open surgery or laparoscopically and a wide variety of techniques are described Bochdalek hernia Typically congenital diaphragmatic hernia 85% cases are located in the left hemi diaphragm Associated with lung hypoplasia on the affected side More common in males Associated with other birth defects May contain stomach May be treated by direct anatomical apposition or placement of mesh. In infants that have severe respiratory compromise mechanical ventilation may be needed and mortality rate is high Morgagni Hernia Rare type of diaphragmatic hernia (approx 2% cases) Herniation through foramen of Morgagni Usually located on the right and tend to be less symptomatic More advanced cases may contain transverse colon As defects are small pulmonary hypoplasia is less common Direct anatomical repair is performed Umbilical hernia Hernia through weak umbilicus Usually presents in childhood Often symptomatic Equal sex incidence 95% will resolve by the age of 2 years Surgery performed after the third birthday Paraumbilical hernia Usually a condition of adulthood Defect is in the linea alba More common in females Multiparity and obesity are risk factors Traditionally repaired using Mayos technique - overlapping repair, mesh may be used though not if small bowel resection is required owing to acute strangulation Littres hernia Hernia containing Meckels diverticulum Resection of the diverticulum is usually required and this will preclude a mesh repair

Answer 1708

It is worth attempting to try and resolve this situation with antibiotics at first presentation. A primary amputation will not heal well and may result in progressive surgery. Osteomyelitis Infection of the bone Causes S aureus and occasionally Enterobacter or Streptococcus species In sickle cell: Salmonella species Clinical features Erythema Pain Fever Investigation X-ray: lytic centre with a ring of sclerosis Bone biopsy and culture Treatment Prolonged antibiotics Sequestra may need surgical removal

Answer 1709

Necrosis and ulcers of the large bowel are a feature of enteroinvasive E.coli. It presents with a dysentery type illness similar to shigellosis. Bacterial Gastroenteritis Causative organisms Features Campylobacter jejuni Most common cause of acute infective diarrhoea Spiral, gram negative rods Usually infects caecum and terminal ileum. Local lymphadenopathy is common May mimic appendicitis as it has marked right iliac fossa pain Reactive arthritis is seen in 1-2% of cases Shigella spp. Members of the enterobacteriaceae Gram negative bacilli Clinically causes dysentery Shigella soneii is the commonest infective organism (mild illness) Usually self limiting, ciprofloxacin may be required if individual is in a high risk group Salmonella spp Facultatively anaerobic, gram negative, enterobacteriaceae Infective dose varies according to subtype Salmonellosis: usually transmitted by infected meat (especially poultry) and eggs E. coli Enteropathogenic Enteroinvasive: dysentery, large bowel necrosis/ulcers Enterotoxigenic: small intestine, travelers diarrhoea Enterohaemorrhagic: 0157, cause a haemorrhagic colitis, haemolytic uraemic syndrome and thrombotic thrombocytopaenic purpura Yersinia enterocolitica Gram negative, coccobacilli Typically produces a protracted terminal ileitis that may mimic Crohns disease Differential diagnosis acute appendicitis May progress to septicaemia in susceptible individuals Usually sensitive to quinolone or tetracyclines Vibrio cholera Short, gram negative rods Transmitted by contaminated water, seafood Symptoms include sudden onset of effortless vomiting and profuse watery diarrhoea Correction of fluid and electrolyte losses are the mainstay of treatment Most cases will resolve, antibiotics are not generally indicated

Answer 1710

These are typical components of an abscess cavity. Polymorphonuclear leucocytes may be found in a granuloma if there is a focus of suppuration. Chronic inflammation Overview Chronic inflammation may occur secondary to acute inflammation.In most cases chronic inflammation occurs as a primary process. These may be broadly viewed as being one of three main processes: Persisting infection with certain organisms such as Mycobacterium tuberculosis which results in delayed type hypersensitivity reactions and inflammation. Prolonged exposure to non-biodegradable substances such as silica or suture materials which may induce an inflammatory response. Autoimmune conditions involving antibodies formed against host antigens. Acute vs. Chronic inflammation Acute inflammation Chronic inflammation Changes to existing vascular structure and increased permeability of endothelial cells Angiogenesis predominates Infiltration of neutrophils Macrophages, plasma cells and lymphocytes predominate Process may resolve with: Suppuration Complete resolution Abscess formation Progression to chronic inflammation Healing by fibrosis Healing by fibrosis is the main result Granulomatous inflammation A granuloma consists of a microscopic aggregation of macrophages (with epithelial type arrangement =epithelioid). Large giant cells may be found at the periphery of granulomas. Mediators Growth factors released by activated macrophages include agents such as interferon and fibroblast growth factor (plus many more). Some of these such as interferons may have systemic features resulting in systemic symptoms and signs, which may be present in individuals with long standing chronic inflammation.

Answer 1711

Microscopic colitis is a common condition characterised by normal endoscopic appearances, microscopic features of colonic inflammation and thickening of the sub epithelial collagen layer. Features such as granulomas are absent. It is the normal endoscopic appearance that makes the other options less likely. IBS is a diagnosis of exclusion and the features of inflammation activity would favor a different diagnosis. Severe cases can be treated with steroids. Other agents such as cholestyramine may be beneficial. It is important to exclude infection with a stool culture if this has not been done, not least because the precipitant of many cases of microscopic colitis is an episode of infective diarrhoea. Diarrhoea World Health Organisation definitions Diarrhoea: > 3 loose or watery stool per day Acute diarrhoea < 14 days Chronic diarrhoea > 14 days Acute Diarrhoea Gastroenteritis May be accompanied by abdominal pain or nausea/vomiting Diverticulitis Classically causes left lower quadrant pain, diarrhoea and fever Antibiotic therapy More common with broad spectrum antibiotics Clostridium difficile is also seen with antibiotic use Constipation causing overflow A history of alternating diarrhoea and constipation may be given May lead to faecal incontinence in the elderly Chronic Diarrhoea Irritable bowel syndrome Extremely common. The most consistent features are abdominal pain, bloating and change in bowel habit. Patients may be divided into those with diarrhoea predominant IBS and those with constipation predominant IBS. Features such as lethargy, nausea, backache and bladder symptoms may also be present Ulcerative colitis Bloody diarrhoea may be seen. Crampy abdominal pain and weight loss are also common. Faecal urgency and tenesmus may occur Crohn's disease Crampy abdominal pains and diarrhoea. Bloody diarrhoea less common than in ulcerative colitis. Other features include malabsorption, mouth ulcers perianal disease and intestinal obstruction Colorectal cancer Symptoms depend on the site of the lesion but include diarrhoea, rectal bleeding, anaemia and constitutional symptoms e.g. Weight loss and anorexia Coeliac disease In children may present with failure to thrive, diarrhoea and abdominal distension In adults lethargy, anaemia, diarrhoea and weight loss are seen. Other autoimmune conditions may coexist Other conditions associated with diarrhoea include: Thyrotoxicosis Laxative abuse Appendicitis with pelvic abscess or pelvic appendix Radiation enteritis Diagnosis Stool culture Abdominal and digital rectal examination Consider colonoscopy (radiological studies unhelpful) Thyroid function tests, serum calcium, anti endomysial antibodies, glucose

Answer 1712

Clostridium perfringens is the most likely pathogen to be associated with gangrene. Surgical Microbiology An extensive topic so an overview is given here. Organisms causing common surgical infections are reasonable topics in the examination. However, microbiology is less rigorously tested than anatomy, for example. Common organisms Staphylococcus aureus Facultative anaerobe Gram positive coccus Haemolysis on blood agar plates Catalase positive 20% population are long term carriers Exo and entero toxin may result in toxic shock syndrome and gastroenteritis respectively Ideally treated with penicillin although many strains now resistant through beta Lactamase production. In the UK less than 5% of isolates are sensitive to penicillin. Resistance to methicillin (and other antibiotics) is mediated by the mec operon , essentially penicillin binding protein is altered and resistance to this class of antibiotics ensues Common cause of cutaneous infections and abscesses Streptococcus pyogenes Gram positive, forms chain like colonies, Lancefield Group A Streptococcus Produces beta haemolysis on blood agar plates Rarely part of normal skin microflora Catalase negative Releases a number of proteins/ virulence factors into host including hyaluronidase, streptokinase which allow rapid tissue destruction Releases superantigens such as pyogenic exotoxin A which results in scarlet fever Remains sensitive to penicillin, macrolides may be used as an alternative. Escherichia coli Gram negative rod Facultative anaerobe, non sporing Wide range of subtypes and some are normal gut commensals Some subtypes such as 0157 may produce lethal toxins resulting in haemolytic-uraemic syndrome Enterotoxigenic E-Coli produces an enterotoxin (ST enterotoxin) that results in large volume fluid secretion into the gut lumen (Via cGMP activation) Enteropathogenic E-Coli binds to intestinal cells and cause structural damage, this coupled with a moderate (or in case of enteroinvasive E-Coli significant) invasive component produces enteritis and large volume diarrhoea together with fever. They are resistant to many antibiotics used to treat gram positive infections and acquire resistance rapidly and are recognised as producing beta lactamases Campylobacter jejuni Curved, gram negative, non sporulating bacteria One of the commonest causes of diarrhoea worldwide Produces enteritis which is often diffuse and blood may be passed Remains a differential for right iliac fossa pain with diarrhoea Self limiting infection so antibiotics are not usually advised. However, the quinolones are often rapidly effective. Helicobacter pylori Gram negative, helix shaped rod, microaerophillic Produces hydrogenase that can derive energy from hydrogen released by intestinal bacteria Flagellated and mobile Those carrying the cag A gene may cause ulcers It secretes urease that breaks down gastric urea> Carbon dioxide and ammonia> ammonium>bicarbonate (simplified!) The bicarbonate can neutralise the gastric acid. Usually colonises the gastric antrum and irritates resulting in increased gastrin release and higher levels of gastric acid. These patients will develop duodenal ulcers. In those with more diffuse H-Pylori infection gastric acid levels are lower and ulcers develop by local tissue damage from H-Pylori- these patients get gastric ulcers. Diagnosis may be made by serology (approx. 75% sensitive). Biopsy urease test during endoscopy probably the most sensitive. In patients who are colonised 10-20% risk of peptic ulcer, 1-2% risk gastric cancer, <1% risk MALT lymphoma.

Answer 1713

Small peripheral breast cancers are well suited to breast conserving surgical techniques. A small peripheral lesion such as this would usually be suitable for breast conserving surgery. Since imaging and clinical examination is not suspicious for axillary disease, a sentinel lymph node biopsy should be performed. Axillary node sampling is a procedure that become obsolete with the introduction of sentinel node biopsy. Breast cancer management - Surgery is performed in most patients suffering from breast cancer. Chemotherapy may be used to downstage tumours and allow breast conserving surgery. Hormonal therapy may also be used for the same purposes. Radiotherapy is given to most patients who have undergone breast conserving surgery (some older patients receiving hormone treatment and who have small low grade tumours may safely avoid DXT. Therapeutic mammoplasty is an option for some patients but requires symmetrizing surgery in most cases. Patients who have undergone mastectomy may be offered a reconstructive procedure either in conjunction with their primary resection or as a staged procedure at a later date. Surgical options Mastectomy vs Wide local excision Mastectomy Wide Local Excision Multifocal tumour Solitary lesion Central tumour Peripheral tumour Large lesion in small breast Small lesion in large breast DCIS >4cm DCIS <4cm Patient Choice Patient choice Central lesions may be managed using breast conserving surgery, where an acceptable cosmetic result may be obtained, this is rarely the case in small breasts Axillary disease As a minimum, all patients with invasive breast cancer should have their axilla staged. In those who do not have overt evidence of axillary nodal involvement this can be undertaken using sentinel lymph node biopsy. Patients with a positive sentinel lymph node biopsy or who have imaging and cytological or histological evidence of axillary nodal metastasis should undergo axillary node clearance or axillary irradiation. Axillary node clearance is associated with the development of lymphoedema, increased risk of cellulitis and frozen shoulder.

Answer 1714

This type of audit is widely undertaken in most trusts in the UK. Audit categories Audits may be used in a variety of clinical settings. These range from standards based audits, which will be familiar to most clinicians, through to systems based audits which focus more on the processes within an organisation. Types of audit Financial audit A historically oriented, independent evaluation performed for the purpose of attesting to the fairness, accuracy, and reliability of financial data Operational audit A future-oriented, systematic, and independent evaluation of organizational activities. Financial data may be used, but the primary sources of evidence are the operational policies and achievements related to organizational objectives. Internal controls and efficiencies may be evaluated during this type of review. Departmental review A current period analysis of administrative functions, to evaluate the adequacy of controls, safeguarding of assets, efficient use of resources, compliance with related laws, regulations and institutional policy and integrity of financial information. Standards based audit Comparison of care or passage of care against set and widely agreed standards or outcomes. Systems based audit Evaluation of processes occurring within an institution. Systems based audits are an integral part of the process of clinical governance.

Answer 1715

Propofol has anti emetic properties which is of considerable advantage in day case anaesthesia. Anaesthetic agents The table below summarises some of the more commonly used IV induction agents Agent Specific features Propofol Rapid onset of anaesthesia Pain on IV injection Rapidly metabolised with little accumulation of metabolites Proven anti emetic properties Moderate myocardial depression Widely used especially for maintaining sedation on ITU, total IV anaesthesia and for daycase surgery Sodium thiopentone Extremely rapid onset of action making it the agent of choice for rapid sequence of induction Marked myocardial depression may occur Metabolites build up quickly Unsuitable for maintenance infusion Little analgesic effects Ketamine May be used for induction of anaesthesia Has moderate to strong analgesic properties Produces little myocardial depression making it a suitable agent for anaesthesia in those who are haemodynamically unstable May induce state of dissociative anaesthesia resulting in nightmares Etomidate Has favorable cardiac safety profile with very little haemodynamic instability No analgesic properties Unsuitable for maintaining sedation as prolonged (and even brief) use may result in adrenal suppression Post operative vomiting is common

Answer 1716

Stored blood has less 2,3 DPG and therefore has a higher affinity for oxygen, this reduces its ability to release it at metabolising tissues. Oxygen Transport Oxygen transport Almost all oxygen is transported within erythrocytes. It has limited solubility and only 1% is carried as solution. Therefore the amount of oxygen transported will depend upon haemoglobin concentration and its degree of saturation. Haemoglobin Globular protein composed of 4 subunits. Haem consists of a protoporphyrin ring surrounding an iron atom in its ferrous state. The iron can form two additional bonds; one with oxygen and the other with a polypeptide chain. There are two alpha and two beta subunits to this polypeptide chain in an adult and together these form globin. Globin cannot bind oxygen but is able to bind to carbon dioxide and hydrogen ions, the beta chains are able to bind to 2,3 diphosphoglycerate. The oxygenation of haemoglobin is a reversible reaction. The molecular shape of haemoglobin is such that binding of one oxygen molecule facilitates the binding of subsequent molecules. Oxygen dissociation curve The oxygen dissociation curve describes the relationship between the percentage of saturated haemoglobin and partial pressure of oxygen in the blood. It is not affected by haemoglobin concentration. Chronic anaemia causes 2, 3 DPG levels to increase, hence shifting the curve to the right Haldane effect Shifts to left = for given oxygen tension there is increased saturation of Hb with oxygen i.e. Decreased oxygen delivery to tissues Bohr effect Shifts to right = for given oxygen tension there is reduced saturation of Hb with oxygen i.e. Enhanced oxygen delivery to tissues Shifts to Left = Lower oxygen delivery HbF, methaemoglobin, carboxyhaemoglobin low [H+] (alkali) low pCO2 low 2,3-DPG low temperature Shifts to Right = Raised oxygen delivery raised [H+] (acidic) raised pCO2 raised 2,3-DPG* raised temperature *2,3-diphosphoglycerate

Answer 1717

Pregabalin is generally the first line agent for neuropathic pain. Management of pain World Health Organisation Analgesic Ladder Initially peripherally acting drugs such as paracetamol or non-steroidal anti-inflammatory drugs (NSAIDs) are given. If pain control is not achieved, the second part of the ladder is to introduce weak opioid drugs such as codeine or dextropropoxyphene together with appropriate agents to control and minimise side effects. The final rung of the ladder is to introduce strong opioid drugs such as morphine. Analgesia from peripherally acting drugs may be additive to that from centrally-acting opioids and thus, the two are given together. The World Federation of Societies of Anaesthesiologists (WFSA) Analgesic Ladder For management of acute pain Initially, the pain can be expected to be severe and may need controlling with strong analgesics in combination with local anaesthetic blocks and peripherally acting drugs. The second rung on the postoperative pain ladder is the restoration of the use of the oral route to deliver analgesia. Strong opioids may no longer be required and adequate analgesia can be obtained by using combinations of peripherally acting agents and weak opioids. The final step is when the pain can be controlled by peripherally acting agents alone. Local anaesthetics Infiltration of a wound with a long-acting local anaesthetic such as Bupivacaine Analgesia for several hours Further pain relief can be obtained with repeat injections or by infusions via a thin catheter Blockade of plexuses or peripheral nerves will provide selective analgesia in those parts of the body supplied by the plexus or nerves Can either be used to provide anaesthesia for the surgery or specifically for postoperative pain relief Especially useful where a sympathetic block is needed to improve postoperative blood supply or where central blockade such as spinal or epidural blockade is contraindicated. Spinal anaesthesia Provides excellent analgesia for surgery in the lower half of the body and pain relief can last many hours after completion of the operation if long-acting drugs containing vasoconstrictors are used. - Side effects of spinal anaesthesia include: hypotension, sensory and motor block, nausea and urinary retention. Epidural anaesthesia An indwelling epidural catheter inserted. This can then be used to provide a continuous infusion of analgesic agents. It can provide excellent analgesia. They are still the preferred option following major open abdominal procedures and help prevent post operative respiratory compromise resulting from pain. - Disadvantages of epidurals is that they usually confine patients to bed, especially if a motor block is present. In addition an indwelling urinary catheter is required. Which may not only impair mobility but also serve as a conduit for infection. They are contraindicated in coagulopathies. Transversus Abdominal Plane block (TAP) In this technique an ultrasound is used to identify the correct muscle plane and local anaesthetic (usually bupivicaine) is injected. The agent diffuses in the plane and blocks many of the spinal nerves. It is an attractive technique as it provides a wide field of blockade but does not require the placement of any indwelling devices. There is no post operative motor impairment. For this reason it is the preferred technique when extensive laparoscopic abdominal procedures are performed. They will then provide analgesia immediately following surgery but as they do not confine the patient to bed, the focus on enhanced recovery can begin sooner. -The main disadvantage is that their duration of action is limited to the half life of the local anaesthetic agent chosen. In addition some anaesthetists do not have the USS skills required to site the injections. Patient Controlled Analgesia (PCA) - Patients administer their own intravenous analgesia and titrate the dose to their own end-point of pain relief using a small microprocessor - controlled pump. Morphine is the most popular drug used. Strong Opioids Severe pain arising from deep or visceral structures requires the use of strong opioids Morphine Short half life and poor bioavailability. Metabolised in the liver and clearance is reduced in patients with liver disease, in the elderly and the debilitated Side effects include nausea, vomiting, constipation and respiratory depression. Tolerance may occur with repeated dosage Pethidine Synthetic opioid which is structurally different from morphine but which has similar actions. Has 10% potency of morphine. Short half life and similar bioavailability and clearance to morphine. Short duration of action and may need to be given hourly. Pethidine has a toxic metabolite (norpethidine) which is cleared by the kidney, but which accumulates in renal failure or following frequent and prolonged doses and may lead to muscle twitching and convulsions. Extreme caution is advised if pethidine is used over a prolonged period or in patients with renal failure. Weak opioids Codeine: markedly less active than morphine, has predictable effects when given orally and is effective against mild to moderate pain. Non opioid analgesics - Mild to moderate pain. Paracetamol Inhibits prostaglandin synthesis. Analgesic and antipyretic properties but little anti-inflammatory effect It is well absorbed orally and is metabolised almost entirely in the liver Side effects in normal dosage and is widely used for the treatment of minor pain. It causes hepatotoxicity in over dosage by overloading the normal metabolic pathways with the formation of a toxic metabolite. NSAIDs Analgesic and anti-inflammatory actions Inhibition of prostaglandin synthesis by the enzyme Cyclooxygenase which catalyses the conversion of arachidonic acid to the various prostaglandins that are the chief mediators of inflammation. All NSAIDs work in the same way and thus there is no point in giving more than one at a time. . NSAIDs are, in general, more useful for superficial pain arising from the skin, buccal mucosa, joint surfaces and bone. Relative contraindications: history of peptic ulceration, gastrointestinal bleeding or bleeding diathesis; operations associated with high blood loss, asthma, moderate to severe renal impairment, dehydration and any history of hypersensitivity to NSAIDs or aspirin. Neuropathic pain National Institute of Clinical Excellence (UK) guidelines: First line: Amitriptyline (Imipramine if cannot tolerate) or pregabalin Second line: Amitriptyline AND pregabalin Third line: refer to pain specialist. Give tramadol in the interim (avoid morphine) If diabetic neuropathic pain: Duloxetine As of 1 April 2019, pregabalin and gabapentin are Class C controlled substances (under the Misuse of Drugs Act 1971) and scheduled under the Misuse of Drugs Regulations 2001 as Schedule 3. Evaluate patients carefully for a history of drug abuse before prescribing and observe patients for development of signs of abuse and dependence (MHRA, Drug Safety Update April 2019). References 1. http://guidance.nice.org.uk/CG173/Guidance/pdf/English 2. Lovich-Sapola J, Smith CE, Brandt CP. Post operative pain control. Surg Clin North Am. 2015 Apr;95(2):301-183. Finnerup N et al. Pharmacotherapy for neuropathic pain in adults: a systematic review and meta-analysis. Lancet Neurol. 2015 Feb;14(2):162-73.

Answer 1718

The subclavian vein lies behind subclavius and the medial part of the clavicle. It rests on the first rib, below and in front of the third part of the subclavian artery, and then on scalenus anterior which separates it from the second part of the artery (posteriorly). Clavicle The clavicle extends from the sternum to the acromion and helps prevent the shoulder falling forwards and downwards. The inferior surface is irregular and strongly marked by ligaments at each end. Laterally, lies the trapezoid line and this runs anterolaterally. Posteriorly, lies the conoid tubercle. These give attachment to the conoid and trapezoid parts of the coracoclavicular ligament. The medial part of the inferior surface has an irregular surface which marks the surface attachment of the costoclavicular ligament. The intermediate portion is marked by a groove for the subclavius muscle. Medially, the superior part of the bone has a raised surface which gives attachment to the clavicular head of sternocleidomastoid. Sternohyoid gains attachment to the posterior surface. Laterally there is an oval articular facet for the acromion and a disk lies between the clavicle and acromion. The capsule of the joint is attached to the ridge on the margin of the facet.

Answer 1719

Increased FRC: Erect position Emphysema Asthma Decreased FRC: Pulmonary fibrosis Laparoscopic surgery Obesity Abdominal swelling Muscle relaxants When the patient is upright the diaphragm and abdominal organs put less pressure on the lung bases, allowing for an increase in the functional residual capacity (FRC). Other causes of increased FRC include: Emphysema Asthma In addition to those listed above, causes of reduced FRC include: Abdominal swelling Pulmonary oedema Reduced muscle tone of the diaphragm Age Definitions Tidal volume (TV) Is the volume of air inspired and expired during each ventilatory cycle at rest. It is normally 500mls in males and 340mls in females. Inspiratory reserve volume (IRV) Is the maximum volume of air that can be forcibly inhaled following a normal inspiration. 3000mls. Expiratory reserve volume (ERV) Is the maximum volume of air that can be forcibly exhaled following a normal expiration. 1000mls. Residual volume (RV) Is that volume of air remaining in the lungs after a maximal expiration. RV = FRC - ERV. 1500mls. Functional residual capacity (FRC) Is the volume of air remaining in the lungs at the end of a normal expiration. FRC = RV + ERV. 2500mls. Vital capacity (VC) Is the maximal volume of air that can be forcibly exhaled after a maximal inspiration. VC = TV + IRV + ERV. 4500mls in males, 3500mls in females. Total lung capacity (TLC) Is the volume of air in the lungs at the end of a maximal inspiration. TLC = FRC + TV + IRV = VC + RV. 5500-6000mls. Forced vital capacity (FVC) The volume of air that can be maximally forcefully exhaled.

Answer 1720

Ulcerative colitis and colorectal cancer Overview risk of colorectal cancer is 10-20 times that of general population the increased risk is mainly related to chronic inflammation worse prognosis than patients without ulcerative colitis (partly due to delayed diagnosis) lesions may be multifocal Factors increasing risk of cancer disease duration > 10 years patients with pancolitis onset before 15 years old unremitting disease poor compliance to treatment

Answer 1721

Tumours of the uterine body will tend to spread to the iliac nodes initially. Tumour expansion crossing different nodal margins this is of considerable clinical significance, if nodal clearance is performed during a Wertheims type hysterectomy. Lymphatic drainage of the ovaries, uterus and cervix The ovaries drain to the para-aortic lymphatics via the gonadal vessels. The uterine fundus has a lymphatic drainage that runs with the ovarian vessels and may thus drain to the para-aortic nodes. Some drainage may also pass along the round ligament to the inguinal nodes. The body of the uterus drains through lymphatics contained within the broad ligament to the iliac lymph nodes. The cervix drains into three potential nodal stations; laterally through the broad ligament to the external iliac nodes, along the lymphatics of the uterosacral fold to the presacral nodes and posterolaterally along lymphatics lying alongside the uterine vessels to the internal iliac nodes.

Answer 1722

Fluid levels in the distal colon are nearly always pathological. In general contents of the left colon transit quickly and are seldom held in situ for long periods, the content is also more solid. Abdominal radiology Plain abdominal x-rays are often used as a first line investigation in patients with acute abdominal pain. A plain abdominal film may demonstrate free air, evidence of bowel obstruction and possibly other causes of pain (e.g. renal or gallbladder stones). Investigation of potential visceral perforation is usually best performed by obtaining an erect chest x-ray, as this is a more sensitive investigation for suspected visceral perforation than recumbent films. Features which are usually abnormal Large amounts of free air (colonic perforation), smaller volumes seen with more proximal perforations. A positive Riglers sign (gas on both sides of the bowel wall). Caecal diameter of >8cm Fluid levels in the colon Ground glass appearance to film (usually due to large amounts of free fluid). Sentinel loop in patients with inflammation of other organs (e.g. pancreatitis). Features which should be expected/ or occur without pathology In Chiladitis sign, a loop of bowel may be interposed between the liver and diaphragm, giving the mistaken impression that free air is present. Following ERCP (and sphincterotomy) air may be identified in the biliary tree. Free intra abdominal air following laparoscopy / laparotomy, although usually dissipates after 48-72 hours.

Answer 1723

Mnemonic to remember causes of right shift of the oxygen dissociation curve: CADET face RIGHT C O2 A cidosis 2,3-DPG E xercise T emperature The curve is shifted to the right when there is an increased oxygen requirement by the tissue. This includes: Increased temperature Acidosis Increased DPG: DPG is found in erythrocytes and is increased during glycolysis. It binds to the Hb molecule, thereby releasing oxygen to tissues. DPG is increased in conditions associated with poor oxygen delivery to tissues, such as anaemia and high altitude. Oxygen Transport Oxygen transport Almost all oxygen is transported within erythrocytes. It has limited solubility and only 1% is carried as solution. Therefore the amount of oxygen transported will depend upon haemoglobin concentration and its degree of saturation. Haemoglobin Globular protein composed of 4 subunits. Haem consists of a protoporphyrin ring surrounding an iron atom in its ferrous state. The iron can form two additional bonds; one with oxygen and the other with a polypeptide chain. There are two alpha and two beta subunits to this polypeptide chain in an adult and together these form globin. Globin cannot bind oxygen but is able to bind to carbon dioxide and hydrogen ions, the beta chains are able to bind to 2,3 diphosphoglycerate. The oxygenation of haemoglobin is a reversible reaction. The molecular shape of haemoglobin is such that binding of one oxygen molecule facilitates the binding of subsequent molecules. Oxygen dissociation curve The oxygen dissociation curve describes the relationship between the percentage of saturated haemoglobin and partial pressure of oxygen in the blood. It is not affected by haemoglobin concentration. Chronic anaemia causes 2, 3 DPG levels to increase, hence shifting the curve to the right Haldane effect Shifts to left = for given oxygen tension there is increased saturation of Hb with oxygen i.e. Decreased oxygen delivery to tissues Bohr effect Shifts to right = for given oxygen tension there is reduced saturation of Hb with oxygen i.e. Enhanced oxygen delivery to tissues Shifts to Left = Lower oxygen delivery HbF, methaemoglobin, carboxyhaemoglobin low [H+] (alkali) low pCO2 low 2,3-DPG low temperature Shifts to Right = Raised oxygen delivery raised [H+] (acidic) raised pCO2 raised 2,3-DPG* raised temperature

Answer 1724

Carcinoma of the prostate typically occurs in the posterior lobe. The median lobe is usually enlarged in BPH. The anterior lobe has little in the way of glandular tissue and is seldom enlarged. Benign Prostatic Hyperplasia Benign prostatic hyperplasia occurs via an increase in the epithelial and stromal cell numbers in the peri-urethral zone of the prostate. BPH is very common and 90% of men aged over 80 will have at least microscopic evidence of benign prostatic hyperplasia. The causes of BPH are still not well understood, but the importance of androgens remains appreciated even if the exact role by which they induce BPH is elusive. Presentation The vast majority of men will present with lower urinary tract symptoms. These will typically be: Poor flow Nocturia Hesitancy Incomplete and double voiding Terminal dribbling Urgency Incontinence Investigation Digital rectal examination to assess prostatic size and morphology. Urine dipstick for infections and haematuria. Uroflowmetry (a flow rate of >15ml/second helps to exclude BOO) Bladder pressure studies may help identify detrusor failure and whilst may not form part of first line investigations should be included in those with atypical symptoms and prior to redo surgery. Bladder scanning to demonstrate residual volumes. USS if high pressure chronic retention. Management Lifestyle changes such as stopping smoking and altering fluid intake may help those with mild symptoms. Medical therapy includes alpha blockers and 5 α reductase inhibitors. The former work quickly on receptor zones located at the bladder neck. Cardiovascular side effects are well documented. The latter work on testosterone metabolising enzymes. Although they have a slower onset of action, the 5 α reductase inhibitors may prevent acute urinary retention. Surgical therapy includes transurethral resection of the prostate and is the treatment of choice in those with severe symptoms and those who fail to respond to medical therapy. More tailored bladder neck incision procedures may be considered in those with small prostates. Retrograde ejaculation may occur following surgery. The change in the type of irrigation solutions used has helped to minimise the TURP syndrome of electrolyte disturbances.

Answer 1725

Peri anal abscess are typically managed by secondary intention healing. Any attempt at early closure is at best futile and at worst dangerous. Insertion of a seton may be considered by an experienced colorectal surgeon, and only if the tract is clearly identifiable with minimal probing. There is seldom a need for flaps, ongoing discharge usually indicates a fistula (managed separately). Wound healing Surgical wounds are either incisional or excisional and either clean, clean contaminated or dirty. Although the stages of wound healing are broadly similar their contributions will vary according to the wound type. The main stages of wound healing include: Haemostasis Minutes to hours following injury Vasospasm in adjacent vessels, platelet plug formation and generation of fibrin rich clot. Inflammation Typically days 1-5 Neutrophils migrate into wound (function impaired in diabetes). Growth factors released, including basic fibroblast growth factor and vascular endothelial growth factor. Fibroblasts replicate within the adjacent matrix and migrate into wound. Macrophages and fibroblasts couple matrix regeneration and clot substitution. Regeneration Typically days 7 to 56 Platelet derived growth factor and transformation growth factors stimulate fibroblasts and epithelial cells. Fibroblasts produce a collagen network. Angiogenesis occurs and wound resembles granulation tissue. Remodeling From 6 weeks to 1 year Longest phase of the healing process and may last up to one year (or longer). During this phase fibroblasts become differentiated (myofibroblasts) and these facilitate wound contraction. Collagen fibres are remodeled. Microvessels regress leaving a pale scar. The above description represents an idealised scenario. A number of diseases may distort this process. Neovascularisation is an important early process. Endothelial cells may proliferate in the wound bed and recanalise to form a vessel. Vascular disease, shock and sepsis can all compromise microvascular flow and impair healing. Conditions such as jaundice will impair fibroblast synthetic function and immunity with a detrimental effect in most parts of the healing process. Problems with scars: Hypertrophic scars Excessive amounts of collagen within a scar. Nodules may be present histologically containing randomly arranged fibrils within and parallel fibres on the surface. The tissue itself is confined to the extent of the wound itself and is usually the result of a full thickness dermal injury. They may go on to develop contractures. Image of hypertrophic scarring. Note that it remains confined to the boundaries of the original wound: Keloid scars Excessive amounts of collagen within a scar. Typically a keloid scar will pass beyond the boundaries of the original injury. They do not contain nodules and may occur following even trivial injury. They do not regress over time and may recur following removal. Image of a keloid scar. Note the extension beyond the boundaries of the original incision: Drugs which impair wound healing: Non steroidal anti inflammatory drugs Steroids Immunosupressive agents Anti neoplastic drugs Closure Delayed primary closure is the anatomically precise closure that is delayed for a few days but before granulation tissue becomes macroscopically evident. Secondary closure refers to either spontaneous closure or to surgical closure after granulation tissue has formed.

Answer 1726

In the UK, platelets either come from pooling of the platelet component from four units of whole donated blood, called random donor platelets, or by plasmapharesis from a single donor. The platelets are suspended in 200-300 ml of plasma and may be stored for up to 4 days in the transfusion laboratory where they are continually agitated at 22oC to preserve function. One adult platelet pool raises the normal platelet count by 30,000 to 60,000 platelets litre. ABO identical or compatible platelets are preferred but not necessary in adults; but rhesus compatibility is required in recipients who are children and women of childbearing age to prevent haemolytic disease of the newborn. Blood products - cross matching Whole blood fractions Fraction Key points Packed red cells Used for transfusion in chronic anaemia and cases where infusion of large volumes of fluid may result in cardiovascular compromise. Product obtained by centrifugation of whole blood. Platelet rich plasma Usually administered to patients who are thrombocytopaenic and are bleeding or require surgery. It is obtained by low speed centrifugation. Platelet concentrate Prepared by high speed centrifugation and administered to patients with thrombocytopaenia. Fresh frozen plasma Prepared from single units of blood. Contains clotting factors, albumin and immunoglobulin. Unit is usually 200 to 250ml. Usually used in correcting clotting deficiencies in patients with hepatic synthetic failure who are due to undergo surgery. Usual dose is 12-15ml/Kg-1. It should not be used as first line therapy for hypovolaemia. Cryoprecipitate Formed from supernatant of FFP. Rich source of Factor VIII and fibrinogen. Allows large concentration of factor VIII to be administered in small volume. SAG-Mannitol Blood Removal of all plasma from a blood unit and substitution with: Sodium chloride Adenine Anhydrous glucose Mannitol Up to 4 units of SAG M Blood may be administered. Thereafter whole blood is preferred. After 8 units, clotting factors and platelets should be considered. Cross matching Must be cross matched Can be ABO incompatible in adults Packed red cells Platelets Whole blood FFP

Answer 1727

Ototoxicity is a recognised adverse reaction with the aminoglycoside antibiotics. Antibiotics: mechanism of action The lists below summarise the site of action of the commonly used antibiotics Inhibit cell wall formation penicillins cephalosporins Inhibit protein synthesis aminoglycosides (cause misreading of mRNA) chloramphenicol macrolides (e.g. erythromycin) tetracyclines fusidic acid Inhibit DNA synthesis quinolones (e.g. ciprofloxacin) metronidazole sulphonamides trimethoprim Inhibit RNA synthesis rifampicin

Answer 1728

Gallstone ileus occurs as a result of the fistula developing between the gallbladder and the duodenum. These tend to become impacted somewhat proximal to the ileocaecal valve and cause small bowel obstruction. The correct management is to remove the gallstone from an enterotomy proximal to the site of stone impaction. The bowel at the site of impaction itself may not heal well and an enterotomy performed at this site may well result in the need for a resection. The standard surgical teaching is that under almost all circumstances the gallbladder should be left in situ, as the anatomy in this area is often hostile and unpredictable. Disconnecting it from the duodenum leaves a large defect that is difficult to close. Gallstones Up to 24% of women and 12% of men may have gallstones. Of these up to 30% may develop local infection and cholecystitis. In patients subjected to surgery 12% will have stones contained within the common bile duct. The majority of gallstones are of a mixed composition (50%) with pure cholesterol stones accounting for 20% of cases. The aetiology of CBD stones differs in the world, in the West most CBD stones are the result of migration. In the East a far higher proportion arise in the CBD de novo. The classical symptoms are of colicky right upper quadrant pain that occurs post prandially. The symptoms are usually worst following a fatty meal when cholecystokinin levels are highest and gallbladder contraction is maximal. Investigation In almost all suspected cases the standard diagnostic work up consists of abdominal ultrasound and liver function tests. Of patients who have stones within the bile duct, 60% will have at least one abnormal result on LFT's. Ultrasound is an important test, but is operator dependent and therefore may occasionally need to be repeated if a negative result is at odds with the clinical picture. Where stones are suspected in the bile duct, the options lie between magnetic resonance cholangiography and intraoperative imaging. The choice between these two options is determined by the skills and experience of the surgeon. The advantages of intra operative imaging are less useful in making therapeutic decisions if the operator is unhappy about proceeding the bile duct exploration, and in such circumstances pre operative MRCP is probably a better option. Specific gallstone and gallbladder related disease Disease Features Management Biliary colic Colicky abdominal pain, worse post prandially, worse after fatty foods If imaging shows gallstones and history compatible then laparoscopic cholecystectomy Acute cholecystitis Right upper quadrant pain Fever Murphys sign on examination Occasionally mildly deranged LFT's (especially if Mirizzi syndrome) Imaging (USS) and cholecystectomy (ideally within 48 hours of presentation) (2) Gallbladder abscess Usually prodromal illness and right upper quadrant pain Swinging pyrexia Patient may be systemically unwell Generalised peritonism not present Imaging with USS +/- CT Scanning Ideally surgery, sub total cholecystectomy may be needed if Calots triangle is hostile In unfit patients percutaneous drainage may be considered Cholangitis Patient severely septic and unwell Jaundice Right upper quadrant pain Fluid resuscitation Broad spectrum intravenous antibiotics Correct any coagulopathy Early ERCP Gallstone ileus Patients may have a history of previous cholecystitis and known gallstones Small bowel obstruction (may be intermittent) Laparotomy and removal of gallstone from small bowel, the enterotomy must be made proximal to the site of obstruction and not at the site of obstruction. The fistula between the gallbladder and duodenum should not be interfered with. Acalculous cholecystitis Patients with inter current illness (e.g. diabetes, organ failure) Patient of systemically unwell Gallbladder inflammation in absence of stones High fever If patient fit then cholecystectomy, if unfit then percutaneous cholecystostomy Treatment Patients with asymptomatic gallstones rarely develop symptoms related to them (less than 2% per year) and may therefore be managed expectantly. In almost all cases of symptomatic gallstones the treatment of choice is cholecystectomy performed via the laparoscopic route. In the very frail patient there is sometimes a role for selective use of ultrasound guided cholecystostomy. During the course of the procedure some surgeons will routinely perform either intra operative cholangiography or laparoscopic USS to either confirm anatomy or to exclude CBD stones. The latter may be more easily achieved by use of laparoscopic ultrasound. If stones are found then the options lie between early ERCP in the day or so following surgery or immediate surgical exploration of the bile duct. When performed via the trans cystic route this adds little in the way of morbidity and certainly results in faster recovery. Where transcystic exploration fails the alternative strategy is that of formal choledochotomy. The exploration of a small duct is challenging and ducts of less than 8mm should not be explored. Small stones that measure less than 5mm may be safely left and most will pass spontaneously. Risks of ERCP(1) Bleeding 0.9% (rises to 1.5% if sphincterotomy performed) Duodenal perforation 0.4% Cholangitis 1.1% Pancreatitis 1.5% References 1. Williams E et al. Guidelines on the management of common bile duct stones (CBDS)Gut 2008;57:10041021 2. Gurusamy KS, Samraj K. Early versus delayed laparoscopic cholecystectomy for acute cholecystitis. Cochrane Database Syst Rev. 2006 Oct 18;(4):CD005440. 3. Gurusamy K and Davidson B. Gallstones. BMJ 2014 (348):27-30.

Answer 1729

Bile duct injuries have worse outcomes if the repair is performed by the surgeon who created the injury and also if the surgeon is not an HPB surgeon. Biliary disease Diagnosis Typical features Pathogenesis Gallstones Typically history of biliary colic or episodes of chlolecystitis. Obstructive type history and test results. Usually small calibre gallstones which can pass through the cystic duct. In Mirizzi syndrome the stone may compress the bile duct directly- one of the rare times that cholecystitis may present with jaundice Cholangitis Usually obstructive and will have Charcot's triad of symptoms (pain, fever, jaundice) Ascending infection of the bile ducts usually by E. coli and by definition occurring in a pool of stagnant bile. Pancreatic cancer Typically painless jaundice with palpable gallbladder (Courvoisier's Law) Direct occlusion of distal bile duct or pancreatic duct by tumour. Sometimes nodal disease at the portal hepatis may be the culprit in which case the bile duct may be of normal calibre. TPN (total parenteral nutrition) associated jaundice Usually follows long term use and is usually painless with non obstructive features Often due to hepatic dysfunction and fatty liver which may occur with long term TPN usage. Bile duct injury Depending upon the type of injury may be of sudden or gradual onset and is usually of obstructive type Often due to a difficult laparoscopicÂ cholecystectomy when anatomy in Calots triangle is not appreciated. In the worst scenario the bile duct is excised and jaundice develops rapidly post operatively. More insidious is that of bile duct stenosis which may be caused by clips or diathermy injury. Cholangiocarcinoma Gradual onset obstructive pattern Direct occlusion by disease and also extrinsic compression by nodal disease at the porta hepatis. Septic surgical patient Usually hepatic features Combination of impaired biliary excretion and drugs such as ciprofloxacin which may cause cholestasis. Metastatic disease Mixed hepatic and post hepatic Combination of liver synthetic failure (late) and extrinsic compression by nodal disease and anatomical compression of intra hepatic structures (earlier)

Answer 1730

The level specified would lie within the femoral triangle and therefore represents the femoral artery. Iliac arteries The common iliac arteries are terminal branches of the abdominal aorta. They begin opposite the middle body of the fourth lumbar vertebra. The superior hypogastric plexus lies anterior to the proximal end and more distally, it is crossed by the ureter. The last two lumbar vertebral bodies, and intervening disc, the sympathetic trunk and the medial part of psoas major lie behind each artery. They are separated from the right artery by the beginning of the inferior vena cava. The only branches of the common iliac arteries are the internal and external iliac arteries. Internal iliac artery Anteromedially, each internal iliac artery is covered by peritoneum, beneath which the ureter descends on the anterior surface of each artery. On the left, the vessel is overlapped by the sigmoid colon and, on the right, the terminal ileum overlies it. Posteriorly, the internal iliac vein and commencement of the common iliac vein are closely related to the artery. The posterior division of the internal iliac artery has parietal branches and the anterior division has both parietal and visceral branches. Branches of the posterior division of the internal iliac Lateral sacral, superior gluteal, iliolumbar artery. Branches of the anterior division of the internal iliac artery Obturator artery, internal pudendal artery, inferior gluteal, inferior vesical artery, artery the ductus deferens, middle rectal, vaginal artery, uterine artery. External iliac artery The external iliac artery extends from a point opposite the sacroiliac joint at the level of the lumbosacral disc to the midinguinal point behind the inguinal ligament, midway between the anterior superior iliac spine and the pubic symphysis.

Answer 1731

Adenocarcinoma of the pancreas is the most likely diagnosis and migratory thrombophlebitis is associated with the condition. Squamous cells carcinoma is extremely uncommon in the pancreas. Gastrinoma are extremely rare and thus not the most likely diagnosis. Pancreatic cancer - Adenocarcinoma Risk factors: Smoking, diabetes, adenoma, familial adenomatous polyposis Mainly occur in the head of the pancreas (70%) Spread locally and metastasizes to the liver Carcinoma of the pancreas should be differentiated from other periampullary tumours with better prognosis Clinical features Weight loss Painless jaundice Epigastric discomfort (pain usually due to invasion of the coeliac plexus is a late feature) Pancreatitis Trousseau's sign: migratory superficial thrombophlebitis Investigations USS: May miss small lesions CT Scanning (pancreatic protocol). If unresectable on CT then no further staging needed PET/CT for those with operable disease on CT alone ERCP/ MRI for bile duct assessment Staging laparoscopy to exclude peritoneal disease Management Head of pancreas: Whipple's resection (SE dumping and ulcers). Newer techniques include pylorus preservation and SMA/ SMV resection Carcinoma body and tail: poor prognosis, distal pancreatectomy, if operable Usually adjuvent chemotherapy for resectable disease ERCP and stent for jaundice and palliation Surgical bypass may be needed for duodenal obstruction

Answer 1732

The most likely vessel from those in the list to cause an acute extra dural haemorrhage is the middle meningeal artery. The anterior and middle cerebral arteries may cause acute sub dural haemorrhage. Acute sub dural haemorrhages usually take slightly longer to evolve than acute extra dural haemorrhages. Middle meningeal artery Middle meningeal artery is typically the third branch of the first part of the maxillary artery, one of the two terminal branches of the external carotid artery. After branching off the maxillary artery in the infratemporal fossa, it runs through the foramen spinosum to supply the dura mater (the outermost meninges) . The middle meningeal artery is the largest of the three (paired) arteries which supply the meninges, the others being the anterior meningeal artery and the posterior meningeal artery. The middle meningeal artery runs beneath the pterion. It is vulnerable to injury at this point, where the skull is thin. Rupture of the artery may give rise to an extra dural hematoma. In the dry cranium, the middle meningeal, which runs within the dura mater surrounding the brain, makes a deep indention in the calvarium. The middle meningeal artery is intimately associated with the auriculotemporal nerve which wraps around the artery making the two easily identifiable in the dissection of human cadavers and also easily damaged in surgery.

Answer 1733

Senna contains glycosides. It passes unchanged into the colon where bacteria hydrolyse the glycosidic bond, releasing the anthracene derivatives. These stimulate the myenteric plexus. Laxatives Bulk forming laxatives Bran Psyllium Methylcellulose Osmotic laxatives Magnesium sulphate Magnesium citrate Sodium phosphate Sodium sulphate Potassium sodium tatrate Polyethylene glycol Docusate Stimulant laxatives Bisacodyl Sodium picosulphate Senna Ricinoleic acid

Answer 1734

The ilioinguinal nerve passes through the inguinal canal and is the nerve most commonly identified during hernia surgery. The genitofemoral nerve splits into two branches, the genital branch passes through the inguinal canal within the cord structures. The femoral branch of the genitofemoral nerve enters the thigh posterior to the inguinal ligament, lateral to the femoral artery. The iliohypogastric nerve pierces the external oblique aponeurosis above the superficial inguinal ring. Ilioinguinal nerve Arises from the first lumbar ventral ramus with the iliohypogastric nerve. It passes inferolaterally through the substance of psoas major and over the anterior surface of quadratus lumborum. It pierces the internal oblique muscle and passes deep to the aponeurosis of the external oblique muscle. It enters the inguinal canal and then passes through the superficial inguinal ring to reach the skin. Branches To supply those muscles of the abdominal wall through which it passes. Skin and fascia over the pubic symphysis, superomedial part of the femoral triangle, surface of the scrotum, root and dorsum of penis or labium majus in females.

Answer 1735

Secretin causes secretion of water and electrolytes Cholecystokinin causes enzyme secretion While secretin will typically increase electrolyte and water volume of secretions, the enzyme content is increased by cholecystokinin. Somatostatin will decrease the volume of secretions. Aldosterone will tend to conserve electrolytes. Pancreas exocrine physiology Composition of pancreatic secretions Pancreatic secretions are usually 1000-1500ml per 24 hours and have a pH of 8. Secretion Source Substances secreted Enzymic Acinar cells Trypsinogen Procarboxylase Amylase Elastase Aqueous Ductal and Centroacinar cells Sodium Bicarbonate Water Potassium Chloride NB: Sodium and potassium reflect their plasma levels; chloride and bicarbonate vary with flow rate Regulation The cephalic and gastric phases (neuronal and physical) are less important in regulating the pancreatic secretions. The effect of digested material in the small bowel stimulates CCK release and ACh which stimulate acinar and ductal cells. Of these CCK is the most potent stimulus. In the case of the ductal cells these are potently stimulated by secretin which is released by the S cells of the duodenum. This results in an increase in bicarbonate. Enzyme activation Trypsinogen is converted via enterokinase to active trypsin in the duodenum. Trypsin then activates the other inactive enzymes

Answer 1736

The patient has an Erb's palsy involving brachial trunks C5-6. Brachial plexus The brachial plexus extends from the neck to the axilla. It is formed by the ventral rami of the fifth to the eighth cervical nerves with the ascending part of the first thoracic nerve. Location of the plexus The ventral rami which form the plexus enter the lower part of the posterior triangle of the neck in series with the ventral rami of the cervical plexus. The second part of the subclavian artery lies immediately anterior to the lower two rami. The upper three rami intermingle and pass inferolaterally towards the axilla and subclavian artery. They are enclosed within an extension of the prevertebral fascia. In the neck the plexus lies deep to platysma, the supraclavicular nerves, inferior belly of omohyoid and the transverse cervical artery. It then passes deep to the clavicle and the suprascapular vessels, to enter the axilla, and thence surround the second part of the axillary artery Composition of the plexus Ventral rami, the roots of the plexus, lie between scalenus medius and anterior. As they enter the posterior triangle, the upper two (C5,6) and lower two (C8, T1) roots of the plexus unite to form the upper and lower trunks of the plexus respectively. Meanwhile, C7 continues as the middle trunk. The lower trunk may groove the superior surface of the first rib posterior to the subclavian artery, and the root from the first ventral ramus is always in contact with it. Each trunk divides into ventral and dorsal divisions which are destined to supply the anterior (flexor) and posterior (extensor) parts of the upper limb. The cords of the plexus are formed in the axilla. The dorsal divisions unite to form the posterior cord (C5-8). The ventral divisions of the upper and middle trunks unite to form the lateral cord (C5-7), while the ventral divisions of the lower trunk continues as the medial cord (C8-T1). The cords are named according to their relationship to the axillary artery. Each cord terminates by dividing into two main branches at the beginning of the third part of the artery. Sympathetic communications The fifth and sixth cervical ventral rami receive grey rami communicantes from the middle cervical ganglion, while the two or more grey rami communicantes pass from the inferior cervical ganglion to the seventh and eighth cervical ventral rami. The first thoracic ventral ramus receives its grey ramus from the cervicothoracic ganglion. Its for this reason that inferior plexus injury can be complicated by a Horners syndrome. Summary Origin Anterior rami of C5 to T1 Sections of the plexus Roots, trunks, divisions, cords, branches Mnemonic:Real Teenagers Drink Cold Beer Roots Located in the posterior triangle Pass between scalenus anterior and medius Trunks Located posterior to middle third of clavicle Upper and middle trunks related superiorly to the subclavian artery Lower trunk passes over 1st rib posterior to the subclavian artery Divisions Apex of axilla Cords Related to axillary artery

Answer 1737

Do not confuse the early phase of Charcot foot with cellulitis Trauma (even if only minor) is a prerequisite. Patients cannot usually recall the traumatic event. The associated neuropathy means that patients continue to walk on the affected foot with subsequent deformity developing over time. Peripheral vascular disease Indications for surgery to revascularise the lower limb Intermittent claudication Critical ischaemia Ulceration Gangrene Intermittent claudication that is not disabling may provide a relative indication, whilst the other complaints are often absolute indications depending upon the frailty of the patient. Assessment Clinical examination Ankle brachial pressure index measurement Duplex arterial ultrasound Angiography (standard, CT or MRI): usually performed only if intervention being considered. Angioplasty In order for angioplasty to be undertaken successfully the artery has to be accessible. The lesion relatively short and reasonable distal vessel runoff. Longer lesions may be amenable to sub-intimal angioplasty. Surgery Surgery will be undertaken where attempts at angioplasty have either failed or are unsuitable. Bypass essentially involves bypassing the affected arterial segment by utilising a graft to run from above the disease to below the disease. As with angioplasty good runoff improves the outcome. Some key concepts with bypass surgery Superficial femoral artery occlusion to the above knee popliteal In the ideal scenario, vein (either in situ or reversed LSV) would be used as a conduit. However, prosthetic material has reasonable 5 year patency rates and some would advocate using this in preference to vein so that vein can be used for other procedures in the future. In general terms either technique is usually associated with an excellent outcome (if run off satisfactory). Procedure Artery dissected out, IV heparin 3,000 units given and then the vessels are cross clamped Longitudinal arteriotomy Graft cut to size and tunneled to arteriotomy sites Anastomosis to femoral artery usually with 5/0 'double ended' Prolene suture Distal anastomosis usually using 6/0 'double ended' Prolene Distal disease Femoro-distal bypass surgery takes longer to perform, is more technically challenging and has higher failure rates. In elderly diabetic patients with poor runoff a primary amputation may well be a safer and more effective option. There is no point in embarking on this type of surgery in patients who are wheelchair bound. In femorodistal bypasses vein gives superior outcomes to PTFE. Rules Vein mapping 1st to see whether there is suitable vein (the preferred conduit). Sub intimal hyperplasia occurs early when PTFE is used for the distal anastomosis and will lead to early graft occlusion and failure. Essential operative procedure as for above knee fem-pop. If there is insufficient vein for the entire conduit then vein can be attached to the end of the PTFE graft and then used for the distal anastomosis. This type of 'vein boot' is technically referred to as a Miller Cuff and is associated with better patency rates than PTFE alone. Remember the more distal the arterial anastomosis the lower the success rate. References Peach G et al. Diagnosis and management of peripheral arterial disease. BMJ 2012; 345: 36-41.

Answer 1738

Hypokalaemia - U waves on ECG J waves are seen in hypothermia whilst delta waves are associated with Wolff Parkinson White syndrome. ECG features in hypokalemia U waves Small or absent T waves (occasionally inversion) Prolonged PR interval ST depression Long QT interval One registered user suggests the following rhyme! In Hypokalaemia, U have no Pot and no T, but a long PR and a long QT!

Answer 1739

Cancer of the pancreatic head will cause obstructive jaundice and intrahepatic duct dilatation. When an ERCP has failed the most appropriate option is to attempt a PTC. This procedure is always preceded by an ultrasound (which presumably this patient has already had or they would not be undergoing an ERCP). Prior to performing the PTC it is important to stage the disease and establish resectability or not. This is because the PTC drains frequently dislodge and fall out. It is usually desirable to pass a stent at the time of doing the PTC to mitigate the effects of this problem. Surgical jaundice Jaundice can present in a manner of different surgical situations. As with all types of jaundice a careful history and examination will often give clues as to the most likely underlying cause. Liver function tests whilst conveying little in the way of information about liver synthetic function, will often facilitate classification as to whether the jaundice is pre hepatic, hepatic or post hepatic. The typical LFT patterns are given below: Location Bilirubin ALT/ AST Alkaline phosphatase Pre hepatic Normal or high Normal Normal Hepatic High Elevated (often very high) Elevated but seldom to very high levels Post hepatic High-very high Moderate elevation High- very high In post hepatic jaundice the stools are often of pale colour and this feature should be specifically addressed in the history. Modes of presentation These are addressed in the table below: Diagnosis Typical features Pathogenesis Gallstones Typically history of biliary colic or episodes of chlolecystitis. Obstructive type history and test results. Usually small calibre gallstones which can pass through the cystic duct. In Mirizzi syndrome the stone may compress the bile duct directly- one of the rare times that cholecystitis may present with jaundice Cholangitis Usually obstructive and will have Charcots triad of symptoms (pain, fever, jaundice) Ascending infection of the bile ducts usually by E. coli and by definition occurring in a pool of stagnant bile. Pancreatic cancer Typically painless jaundice with palpable gallbladder (Courvoisier's Law) Direct occlusion of distal bile duct or pancreatic duct by tumour. Sometimes nodal disease at the portal hepatis may be the culprit in which case the bile duct may be of normal calibre. TPN associated jaundice Usually follows long term use and is usually painless with non obstructive features Often due to hepatic dysfunction and fatty liver which may occur with long term TPN usage. Bile duct injury Depending upon the type of injury may be of sudden or gradual onset and is usually of obstructive type Often due to a difficult cholecystectomy when anatomy in Calots triangle is not appreciated. In the worst scenario the bile duct is excised and jaundice offers rapidly post operatively. More insidious is that of bile duct stenosis which may be caused by clips or diathermy injury. Cholangiocarcinoma Gradual onset obstructive pattern Direct occlusion by disease and also extrinsic compression by nodal disease at the porta hepatis. Septic surgical patient Usually hepatic features Combination of impaired biliary excretion and drugs such as ciprofloxacin which may cause cholestasis. Metastatic disease Mixed hepatic and post hepatic Combination of liver synthetic failure (late) and extrinsic compression by nodal disease and anatomical compression of intra hepatic structures (earlier) Diagnosis An ultrasound of the liver and biliary tree is the most commonly used first line test. This will establish bile duct calibre, often ascertain the presence of gallstones, may visualise pancreatic masses and other lesions. The most important clinical question is essentially the extent of biliary dilatation and its distribution. Where pancreatic neoplasia is suspected, the next test should be a pancreatic protocol CT scan. With liver tumours and cholangiocarcinoma an MRI/ MRCP is often the preferred option. PET scans may be used to stage a number of malignancies but do not routinely form part of first line testing. Where MRCP fails to give adequate information an ERCP may be necessary. In many cases this may form part of patient management. It is however, invasive and certainly not without risk and highly operator dependent. Management Clearly this will depend to an extent upon the underlying cause but relief of jaundice is important, even if surgery forms part of the planned treatment. Patients with unrelieved jaundice have a much higher incidence of septic complications, bleeding and death. Screen for and address any clotting irregularities In patients with malignancy a stent will need to be inserted. These come in two main types; metal and plastic. Plastic stents are cheap and easy to replace and should be used if any surgical intervention (e.g. Whipples) is planned. However, they are prone to displacement and blockage. Metal stents are much more expensive and may compromise a surgical resection. However, they are far less prone to displacement and to a lesser extent blockage than their plastic counterparts. If malignancy is in bile duct/ pancreatic head and stenting has been attempted and has failed, then an alternative strategy is to drain the biliary system percutaneously via a transhepatic route. It may also be possible to insert a stent in this way. One of the main problems with temporary PTC's is their propensity to displacement, which may result in a bile leak. In patients who have a bile duct injury surgery will be required to repair the defect. If the bile duct has been inadvertently excised then a hepatico-jejunostomy will need to be created (difficult!) If gallstones are the culprit, then these may be removed by ERCP and a cholecystectomy performed. Where there is doubt about the efficacy of the ERCP an operative cholangiogram should be performed and bile duct exploration undertaken where stones remain. When the bile duct has been formally opened the options are between closure over a T tube, a choledochoduodenostomy or choledochojejunostomy. Patients with cholangitis should receive high dose broad spectrum antibiotics via the intravenous route. Biliary decompression should follow soon afterwards, instrumenting the bile duct of these patients will often provoke a septic episode (but should be done anyway).

Answer 1740

Methylene blue stains the parathyroid glands and can be useful in facilitating their identification. Preparation for surgery Elective and emergency patients require different preparation. Elective cases Consider pre admission clinic to address medical issues. Blood tests including FBC, U+E, LFT's, Clotting, Group and Save Urine analysis Pregnancy test Sickle cell test ECG/ Chest x-ray Exact tests to be performed will depend upon the proposed procedure and patient fitness. Risk factors for development of deep vein thrombosis should be assessed and a plan for thromboprophylaxis formulated. Diabetes Diabetic patients have greater risk of complications. Poorly controlled diabetes carries high risk of wound infections. Patients with diet or tablet controlled diabetes may be managed using a policy of omitting medication and checking blood glucose levels regularly. Diabetics who are poorly controlled or who take insulin may require a intravenous sliding scale. Potassium supplementation should also be given. Diabetic cases should be operated on first. Emergency cases Stabilise and resuscitate where needed. Consider whether antibiotics are needed and when and how they should be administered. Inform blood bank if major procedures planned particularly where coagulopathies are present at the outset or anticipated (e.g. Ruptured AAA repair) Don't forget to consent and inform relatives. Special preparation Some procedures require special preparation: Thyroid surgery; vocal cord check. Parathyroid surgery; consider methylene blue to identify gland. Sentinel node biopsy; radioactive marker/ patent blue dye. Surgery involving the thoracic duct; consider administration of cream. Pheochromocytoma surgery; will need alpha and beta blockade. Surgery for carcinoid tumours; will need covering with octreotide. Colorectal cases; bowel preparation (especially left sided surgery) Thyrotoxicosis; lugols iodine/ medical therapy. References Management of adults with diabetes undergoing surgery and elective procedures. NHS Diabetes. April 2011.

Answer 1741

Drugs in the tetrahydroisoquinoline such as atracurium cause histamine release. Vecuronium and suxamethonium do not do this. Muscle relaxants Suxamethonium Depolarising neuromuscular blocker Inhibits action of acetylcholine at the neuromuscular junction Degraded by plasma cholinesterase and acetylcholinesterase (affected by lack of acetylcholinesterase) Fastest onset and shortest duration of action of all muscle relaxants Produces generalised muscular contraction prior to paralysis Adverse effects include hyperkalaemia, malignant hyperthermia, delayed recovery Atracurium Non depolarising neuromuscular blocking drug Duration of action usually 30-45 minutes Generalised histamine release on administration may produce facial flushing, tachycardia and hypotension Not excreted by liver or kidney, broken down in tissues by hydrolysis Reversed by neostigmine Vecuronium Non depolarising neuromuscular blocking drug Duration of action approximately 30 - 40 minutes Degraded by liver and kidney and effects prolonged in organ dysfunction Effects may be reversed by neostigmine Pancuronium Non depolarising neuromuscular blocker Onset of action approximately 2-3 minutes Duration of action up to 2 hours Effects may be partially reversed with drugs such as neostigmine

Answer 1742

The patient will require skin preparation. However, use of glutaraldehyde or sodium hypochlorite would be an inappropriate choice. As the Mayo repair does not involve implantation of prosthetic mesh the use of antibiotics is not appropriate. Surgical site infection - Surgical site infections may occur following a breach in tissue surfaces and allow normal commensals and other pathogens to initiate infection. They are a major cause of morbidity and mortality. Surgical site infections (SSI) comprise up to 20% of all healthcare associated infections and at least 5% of patients undergoing surgery will develop an SSI as a result. In many cases the organisms are derived from the patient's own body. Measures that may increase the risk of SSI include: Shaving the wound using a razor (disposable clipper preferred) Using a non iodine impregnated incise drape if one is deemed to be necessary Tissue hypoxia Delayed administration of prophylactic antibiotics in tourniquet surgery Preoperatively Don't remove body hair routinely If hair needs removal, use electrical clippers with single use head (razors increase infection risk) Antibiotic prophylaxis if: - placement of prosthesis or valve - clean-contaminated surgery - contaminated surgery Use local formulary Aim to give single dose IV antibiotic on anaesthesia If a tourniquet is to be used, give prophylactic antibiotics earlier Intraoperatively Prepare the skin with alcoholic chlorhexidine (Lowest incidence of SSI) Cover surgical site with dressing A recent meta analysis has confirmed that administration of supplementary oxygen does not reduce the risk of wound infection. In contrast to previous individual RCT's(1) Wound edge protectors do not appear to confer benefit (2) Post operatively Tissue viability advice for management of surgical wounds healing by secondary intention Use of diathermy for skin incisions In the NICE guidelines the use of diathermy for skin incisions is not advocated(3). Several randomised controlled trials have been undertaken and demonstrated no increase in risk of SSI when diathermy is used(4). References 1. Brar M et al.. Perioperative supplemental oxygen in colorectal patients: a meta analysis. J Surg Res 2011 (166): 227 -235. 2. Pinkney T et al. Impact of wound edge protection devices on surgical site infection after laparotomy: impact of a multicentre randomised controlled trial (ROSSINI Trial). BMJ 2013 (347):10. 3. http://www.nice.org.uk/CG74 4. Ahmad N and Ahmed A. Meta-analysis of the effectiveness of surgical scalpel or diathermy in making abdominal skin incisions. Ann Surg 2011, 253(1):8-13.

Answer 1743

Buergers disease is most common in young male smokers. This demographic is changing in those areas where young female smokers are more common. In the acute lesion the internal elastic lamina of the vessels is usually intact. As the disease progresses the changes progress to hypercellular occlusive thrombus. Tortuous corkscrew collaterals may reconstitute patent segments of the distal tibial or pedal vessels. Vasculitis The vasculitides are a group of conditions characterised by inflammation of the blood vessel walls. This may, in turn, compromise vessel integrity. Constitutional symptoms may be present. Whilst certain disease subtypes are reported to affect specific vessels, there is often a degree of overlap clinically. Vessel diameter and vasculitis classification Aorta and branches Takayasu's arteritis Buergers disease Giant cell arteritis Large and medium sized arteries Buergers disease Giant cell arteritis Polyarteritis nodosa Medium sized muscular arteries Polyarteritis nodosa Wegeners granulomatosis Small muscular arteries Granulomatosis with polyangiitis Rheumatoid vasculitis Specific conditions Takyasu's arteritis Inflammatory, obliterative arteritis affecting aorta and branches Females> Males Symptoms may include upper limb claudication Clinical findings include diminished or absent pulses ESR often affected during the acute phase Buergers disease Segmental thrombotic occlusions of the small and medium sized lower limb vessels Commonest in young male smokers Proximal pulses usually present, but pedal pulses are lost An acuter hypercellular occlusive thrombus is often present Tortuous corkscrew shaped collateral vessels may be seen on angiography Giant cell arteritis Systemic granulomatous arteritis that usually affects large and medium sized vessels Females > Males Temporal arteritis is commonest type Granulomatous lesions may be seen on biopsy (although up to 50% are normal) Polyarteritis nodosa Systemic necrotising vasculitis affecting small and medium sized muscular arteries Most common in populations with high prevalence of hepatitis B Renal disease is seen in 70% cases Angiography may show saccular or fusiform aneurysms and arterial stenoses Granulomatosis with polyangiitis Predominantly affects small and medium sized arteries Systemic necrotising granulomatous vasculitis Cutaneous vascular lesions may be seen (ulceration, nodules and purpura) Sinus imaging may show mucosal thickening and air fluid levels Treatment Conditions such as Buergers disease are markedly helped by smoking cessation. Immunosupression is the main treatment for vasculitides.

Answer 1744

Lesions distal to the dentate line drain to the inguinal nodes. Occasionally this will result in the need for a block dissection of the groin. Rectum The rectum is approximately 12 cm long. It is a capacitance organ. It has both intra and extraperitoneal components. The transition between the sigmoid colon is marked by the disappearance of the tenia coli.The extra peritoneal rectum is surrounded by mesorectal fat that also contains lymph nodes. This mesorectal fatty layer is removed surgically during rectal cancer surgery (Total Mesorectal Excision). The fascial layers that surround the rectum are important clinical landmarks, anteriorly lies the fascia of Denonvilliers. Posteriorly lies Waldeyers fascia. Extra peritoneal rectum Posterior upper third Posterior and lateral middle third Whole lower third Relations Anteriorly (Males) Rectovesical pouch Bladder Prostate Seminal vesicles Anteriorly (Females) Recto-uterine pouch (Douglas) Cervix Vaginal wall Posteriorly Sacrum Coccyx Middle sacral artery Laterally Levator ani Coccygeus Arterial supply Superior rectal artery Middle rectal artery (from the internal iliac) Inferior rectal artery (from the pudendal vessels) Venous drainage Superior rectal vein Inferior rectal vein Note the venous drainage is a site of portosystemic anastomosis. Lymphatic drainage Mesorectal lymph nodes (superior to dentate line) Inguinal nodes (inferior to dentate line)

Answer 1745

The transversalis fascia forms the superolateral edge of the deep inguinal ring. The epigastric vessels form its inferomedial wall. Inguinal canal Location Above the inguinal ligament The inguinal canal is 4cm long The superficial ring is located anterior to the pubic tubercle The deep ring is located approximately 1.5-2cm above the half way point between the anterior superior iliac spine and the pubic tubercle Boundaries of the inguinal canal Floor External oblique aponeurosis Inguinal ligament Lacunar ligament Roof Internal oblique Transversus abdominis Anterior wall External oblique aponeurosis Posterior wall Transversalis fascia Conjoint tendon Laterally Internal ring Transversalis fascia Fibres of internal oblique Medially External ring Conjoint tendon Contents Males Spermatic cord and ilioinguinal nerve As it passes through the canal the spermatic cord has 3 coverings: External spermatic fascia from external oblique aponeurosis Cremasteric fascia Internal spermatic fascia Females Round ligament of uterus and ilioinguinal nerve

Answer 1746

Waldeyers fascia- Posterior ano-rectum Sibsons fascia- Lung apex Bucks fascia- Base of penis Gerotas fascia- Surrounding kidney Denonvilliers fascia- Between rectum and prostate Renal anatomy Each kidney is about 11cm long, 5cm wide and 3cm thick. They are located in a deep gutter alongside the projecting vertebral bodies, on the anterior surface of psoas major. In most cases the left kidney lies approximately 1.5cm higher than the right. The upper pole of both kidneys approximates with the 11th rib (beware pneumothorax during nephrectomy). On the left hand side the hilum is located at the L1 vertebral level and the right kidney at level L1-2. The lower border of the kidneys is usually alongside L3. The table below shows the anatomical relations of the kidneys: Relations Relations Right Kidney Left Kidney Posterior Quadratus lumborum, diaphragm, psoas major, transversus abdominis Quadratus lumborum, diaphragm, psoas major, transversus abdominis Anterior Hepatic flexure of colon Stomach, Pancreatic tail Superior Liver, adrenal gland Spleen, adrenal gland Fascial covering Each kidney and suprarenal gland is enclosed within a common layer of investing fascia, derived from the transversalis fascia. It is divided into anterior and posterior layers (Gerotas fascia). Renal structure Kidneys are surrounded by an outer cortex and an inner medulla which usually contains between 6 and 10 pyramidal structures. The papilla marks the innermost apex of these. They terminate at the renal pelvis, into the ureter. Lying in a hollow within the kidney is the renal sinus. This contains: 1. Branches of the renal artery 2. Tributaries of the renal vein 3. Major and minor calyces's 4. Fat Structures at the renal hilum The renal vein lies most anteriorly, then renal artery (it is an end artery) and the ureter lies most posterior.

Answer 1747

Curlings ulcers typically occur secondary to thermal injuries and are caused by loss of GI protective mechanisms. They are at greater risk of perforation than stress ulcers and may also haemorrhage. Burns Burns may be thermal, chemical or electrical. In the former category are burns which occur as a result of heat. Chemical burns occur when the skin is exposed to an extremely caustic or alkaline substance. Electrical burns occur following exposure to electrical current. The immediate management includes removal of the burning source which usually includes irrigation of the burned area. A detailed assessment then needs to be made of the extent of the burns and a number of charts are available for recording this information. The degree of injury relates to the temperature and duration of exposure. Most domestic burns are mainly scalds in young children. Following the burn, there is a local response with progressive tissue loss and release of inflammatory cytokines. Systemically, there are cardiovascular effects resulting from fluid loss and sequestration of fluid into the third space. There is a marked catabolic response. Immunosuppression is common with large burns and bacterial translocation from the gut lumen is a recognised event. Sepsis is a common cause of death following major burns. Types of burn Type of burn Skin layers affected Skin appearance Blanching Management Epidermal/Superficial Epidermis Red, moist Yes Superficial partial thickness Epidermis and part of papillary dermis affected Pale, dry Yes Normally heals with no intervention Deep partial thickness Epidermis, whole papillary dermis affected Mottled red colour No Needs surgical intervention (depending on site) Full thickness Whole skin layer and subcutaneous tissue affected Dry, leathery hard wound No Burns centre Depth of burn assessment Bleeding on needle prick Sensation Appearance Blanching to pressure Percentage burn estimation Lund Browder chart: most accurate even in children Wallace rule of nines Palmar surface: surface area palm = 0.8% burn >15% body surface area burns in adults needs urgent burn fluid resuscitation Transfer to burn centre if: Need burn shock resuscitation Face/hands/genitals affected Deep partial thickness or full thickness burns Significant electrical/chemical burns Management The initial aim is to stop the burning process and resuscitate the patient. Intravenous fluids will be required for children with burns greater than 10% of total body surface area. Adults with burns greater than 15% of total body surface area will also require IV fluids. The fluids are calculated using the Parkland formula which is; volume of fluid= total body surface area of the burn % x weight (Kg) x2-4 (preference for lower amount i.e. 2ml to avoid excessive fluid overload). Half of the fluid is administered in the first 8 hours. A urinary catheter should be inserted. Analgesia should be given. Complex burns, burns involving the hand perineum and face and burns >10% in adults and >5% in children should be transferred to a burns unit. Circumferential burns affecting a limb or severe torso burns impeding respiration may require escharotomy to divide the burnt tissue. Conservative management is appropriate for superficial burns and mixed superficial burns that will heal in 2 weeks. More complex burns may require excision and skin grafting. Excision and primary closure is not generally practised as there is a high risk of infection. There is no evidence to support the use of anti microbial prophylaxis or topical antibiotics in burn patients. Escharotomies Indicated in circumferential full thickness burns to the torso or limbs. Careful division of the encasing band of burn tissue will potentially improve ventilation (if the burn involves the torso), or relieve compartment syndrome and oedema (where a limb is involved) References www.euroburn.org/e107files/downloads/guidelinesburncare.pdf Barajas-Nava LA, LÃ³pez-Alcalde J, RoquÃ© i Figuls M, SolÃ I, Bonfill Cosp X. Antibiotic prophylaxis for preventing burn wound infection. Cochrane Database of Systematic Reviews 2013, Issue 6. Art. No.: CD008738. DOI: 10.1002/14651858.CD008738.pub2. Hettiaratchy S & Papini R. Initial management of a major burn: assessment and resuscitation. BMJ 2004;329:101-103

Answer 1748

Where a research participant experiences an adverse outcome, the correct course of action is to refer to the ethics committee that approved the study. Minor adverse effects are usually reviewed by the data monitoring committee and reported annually. However, a serious event is reported immediately. It would not be appropriate to refer to the GMC though, it may be that the surgeon deviated from the protocol for good reason. Audit and Research Clinical audit Quality improvement process that seeks to improve patient care and outcomes through systematic review of care against explicit criteria and the implementation of change. Aspects of the structure, processes, and outcomes of care are selected and systematically evaluated against explicit criteria. Where indicated, changes are implemented at an individual, team, or service level and further monitoring is used to confirm improvement in healthcare delivery. (NICE). Research Aims to derive new knowledge which is potentially generalisable or transferable.

Answer 1749

Chemotherapy for colonic cancer is offered when patients have nodal disease. Colorectal cancer treatment Patients diagnosed as having colorectal cancer should be completely staged using CT of the chest/ abdomen and pelvis. Their entire colon should have been evaluated with colonoscopy or CT colonography. Patients whose tumours lie below the peritoneal reflection should have their mesorectum evaluated with MRI. Once their staging is complete patients should be discussed within a dedicated colorectal MDT meeting and a treatment plan formulated. Treatment of colonic cancer Cancer of the colon is nearly always treated with surgery. Stents, surgical bypass and diversion stomas may all be used as palliative adjuncts. Resectional surgery is the only option for cure in patients with colon cancer. The procedure is tailored to the patient and the tumour location. The lymphatic drainage of the colon follows the arterial supply and therefore most resections are tailored around the resection of particular lymphatic chains (e.g. ileo-colic pedicle for right sided tumours). Some patients may have confounding factors that will govern the choice of procedure, for example a tumour in a patient from a HNPCC family may be better served with a panproctocolectomy rather than segmental resection. Following resection the decision has to be made regarding restoration of continuity. For an anastomosis to heal the key technical factors include; adequate blood supply, mucosal apposition and no tissue tension. Surrounding sepsis, unstable patients and inexperienced surgeons may compromise these key principles and in such circumstances it may be safer to construct an end stoma rather than attempting an anastomosis. When a colonic cancer presents with an obstructing lesion; the options are to either stent it or resect. In modern practice it is unusual to simply defunction a colonic tumour with a proximal loop stoma. This differs from the situation in the rectum (see below). Following resection patients with risk factors for disease recurrence are usually offered chemotherapy, a combination of 5FU and oxaliplatin is common. Rectal cancer The management of rectal cancer is slightly different to that of colonic cancer. This reflects the rectum's anatomical location and the challenges posed as a result. Tumours located in the rectum can be surgically resected with either an anterior resection or an abdomino - perineal resection. The technical aspects governing the choice between these two procedures can be complex to appreciate and the main point to appreciate for the MRCS is that involvement of the sphincter complex or very low tumours require APER. In the rectum a 2cm distal clearance margin is required and this may also impact on the procedure chosen. In addition to excision of the rectal tube an integral part of the procedure is a meticulous dissection of the mesorectal fat and lymph nodes (total mesorectal excision/ TME). In rectal cancer surgery invovlement of the cirumferential resection margin carries a high risk of disease recurrence. Because the rectum is an extraperitoneal structure (until you remove it that is!) it is possible to irradiate it, something which cannot be offered for colonic tumours. This has a major impact in rectal cancer treatment and many patients will be offered neoadjuvent radiotherapy (both long and short course) prior to resectional surgery. Patients with T1, 2 and 3 /N0 disease on imaging do not require irradiation and should proceed straight to surgery. Patients with T4 disease will typically have long course chemo radiotherapy. Patients presenting with large bowel obstruction from rectal cancer should not undergo resectional surgery without staging as primary treatment (very different from colonic cancer). This is because rectal surgery is more technically demanding, the anastomotic leak rate is higher and the danger of a positive resection margin in an unstaged patient is high. Therefore patients with obstructing rectal cancer should have a defunctioning loop colostomy. Summary of procedures The operations for cancer are segmental resections based on blood supply and lymphatic drainage. These commonly performed procedures are core knowledge for the MRCS and should be understood. Site of cancer Type of resection Anastomosis Risk of leak Right colon Right hemicolectomy Ileo-colic Low <5% Transverse Extended right hemicolectomy Ileo-colic Low <5% Splenic flexure Extended right hemicolectomy Ileo-colic Low <5% Splenic flexure Left hemicolectomy Colo-colon 2-5% Left colon Left hemicolectomy Colo-colon 2-5% Sigmoid colon High anterior resection Colo-rectal 5% Upper rectum Anterior resection (TME) Colo-rectal 5% Low rectum Anterior resection (Low TME) Colo-rectal (+/- Defunctioning stoma) 10% Anal verge Abdomino-perineal excision of colon and rectum None n/a In the emergency setting, where the bowel has perforated, the risk of an anastomotic breakdown is much greater, particularly when the anastomosis is colon-colon. In this situation, an end colostomy is often safer and can be reversed later. When resection of the sigmoid colon is performed and an end colostomy is fashioned the operation is referred to as a Hartmans procedure. Whilst left sided resections are more risky, ileo-colic anastomoses are relatively safe even in the emergency setting and do not need to be defunctioned. References A review of the diagnosis and management of colorectal cancer and a summary of the UK National Institute of Clinical Excellence guidelines is provided in: NICE Guideline NG151. Last updated in 2020.

Answer 1750

Ascending infection of the genitourinary tract is most commonly caused by E-Coli. Other organisms may be accountable, however, these are less common Surgical Microbiology An extensive topic so an overview is given here. Organisms causing common surgical infections are reasonable topics in the examination. However, microbiology is less rigorously tested than anatomy, for example. Common organisms Staphylococcus aureus Facultative anaerobe Gram positive coccus Haemolysis on blood agar plates Catalase positive 20% population are long term carriers Exo and entero toxin may result in toxic shock syndrome and gastroenteritis respectively Ideally treated with penicillin although many strains now resistant through beta Lactamase production. In the UK less than 5% of isolates are sensitive to penicillin. Resistance to methicillin (and other antibiotics) is mediated by the mec operon , essentially penicillin binding protein is altered and resistance to this class of antibiotics ensues Common cause of cutaneous infections and abscesses Streptococcus pyogenes Gram positive, forms chain like colonies, Lancefield Group A Streptococcus Produces beta haemolysis on blood agar plates Rarely part of normal skin microflora Catalase negative Releases a number of proteins/ virulence factors into host including hyaluronidase, streptokinase which allow rapid tissue destruction Releases superantigens such as pyogenic exotoxin A which results in scarlet fever Remains sensitive to penicillin, macrolides may be used as an alternative. Escherichia coli Gram negative rod Facultative anaerobe, non sporing Wide range of subtypes and some are normal gut commensals Some subtypes such as 0157 may produce lethal toxins resulting in haemolytic-uraemic syndrome Enterotoxigenic E-Coli produces an enterotoxin (ST enterotoxin) that results in large volume fluid secretion into the gut lumen (Via cGMP activation) Enteropathogenic E-Coli binds to intestinal cells and cause structural damage, this coupled with a moderate (or in case of enteroinvasive E-Coli significant) invasive component produces enteritis and large volume diarrhoea together with fever. They are resistant to many antibiotics used to treat gram positive infections and acquire resistance rapidly and are recognised as producing beta lactamases Campylobacter jejuni Curved, gram negative, non sporulating bacteria One of the commonest causes of diarrhoea worldwide Produces enteritis which is often diffuse and blood may be passed Remains a differential for right iliac fossa pain with diarrhoea Self limiting infection so antibiotics are not usually advised. However, the quinolones are often rapidly effective. Helicobacter pylori Gram negative, helix shaped rod, microaerophillic Produces hydrogenase that can derive energy from hydrogen released by intestinal bacteria Flagellated and mobile Those carrying the cag A gene may cause ulcers It secretes urease that breaks down gastric urea> Carbon dioxide and ammonia> ammonium>bicarbonate (simplified!) The bicarbonate can neutralise the gastric acid. Usually colonises the gastric antrum and irritates resulting in increased gastrin release and higher levels of gastric acid. These patients will develop duodenal ulcers. In those with more diffuse H-Pylori infection gastric acid levels are lower and ulcers develop by local tissue damage from H-Pylori- these patients get gastric ulcers. Diagnosis may be made by serology (approx. 75% sensitive). Biopsy urease test during endoscopy probably the most sensitive. In patients who are colonised 10-20% risk of peptic ulcer, 1-2% risk gastric cancer, <1% risk MALT lymphoma.

Answer 1751

Inflammatory breast cancers have an aggressive nature. Dissemination occurs early and is more resistant to adjuvant treatments than other types of breast cancer. Often occurs in pregnancy or lactation. Breast cancer - Commoner in the older age group Invasive ductal carcinomas are the most common type. Some may arise as a result of ductal carcinoma in situ (DCIS). There are associated carcinomas of special type e.g. Tubular that may carry better prognosis. The pathological assessment involves assessment of the tumour and lymph nodes, sentinel lymph node biopsy is often used to minimise the morbidity of an axillary dissection. Treatment, typically this is either wide local excision or mastectomy. There are many sub types of both of these that fall outside of the MRCS. Some key rules to bear in mind. Whatever operation is contemplated the final cosmetic outcome does have a bearing. A woman with small breasts and a large tumour will tend to fare better with mastectomy, even if clear pathological and clinical margins can be obtained. Conversely a women with larger breasts may be able to undergo breast conserving surgery even with a relatively large primary lesion (NB tumours >4cm used to attract recommendation for mastectomy). For screen detected and impalpable tumour image guidance will be necessary. Reconstruction is always an option following any resectional procedure. However, its exact type must be tailored to age and co-morbidities of the patient. The main operations in common use include latissimus dorsi myocutaneous flap and sub pectoral implants. Women wishing to avoid a prosthesis may be offered TRAM or DIEP flaps. Surgical options Mastectomy vs Wide local excision Mastectomy Wide Local Excision Multifocal tumour Solitary lesion Central tumour Peripheral tumour Large lesion in small breast Small lesion in large breast DCIS >4cm DCIS <4cm Patient Choice Patient choice Central lesions may be managed using breast conserving surgery where an acceptable cosmetic result may be obtained, this is rarely the case in small breasts A compelling indication for mastectomy, a larger tumour that would be unsuitable for breast conserving surgery Whatever surgical option is chosen the aim should be to have a local recurrence rate of 5% or less at 5 years [1]. Nottingham Prognostic Index The Nottingham Prognostic Index can be used to give an indication of survival. In this system the tumour size is weighted less heavily than other major prognostic parameters. Calculation of NPI Tumour Size x 0.2 + Lymph node score(From table below)+Grade score(From table below). Score Lymph nodes involved Grade 1 0 1 2 1-3 2 3 >3 3 Prognosis Score Percentage 5 year survival 2.0 to 2.4 93% 2.5 to 3.4 85% 3.5 to 5.4 70% >5.4 50% This data was originally published in 1992. It should be emphasised that other factors such as vascular invasion and receptor status also impact on survival and are not included in this data and account for varying prognoses often cited in the literature. References For guidance on how breast cancer is managed in the United Kingdom visit the Association of Breast Surgery website (www.https://associationofbreastsurgery.org.uk/).

Answer 1752

Phosphate is the most important urinary buffer. Its concentration is raised relative to that of plasma. While phosphate is a minor extracellular buffer, under ordinary circumstances it is the single most important urinary buffer. Since, pH of urine is commonly close to the pK of the phosphate buffer pair, it functions as an ideal urinary buffer. Proteins cannot act as urinary buffers as they are not filtered. Renal Physiology Overview Each nephron is supplied with blood from an afferent arteriole that opens onto the glomerular capillary bed. Blood then flows to an efferent arteriole, supplying the peritubular capillaries and medullary vasa recta. The kidney receives up to 25% of resting cardiac output. Control of blood flow The kidney is able to autoregulate its blood flow between systolic pressures of 80- 180mmHg so there is little variation in renal blood flow. This is achieved by myogenic control of arteriolar tone, both sympathetic input and hormonal signals (e.g. renin) are responsible. Glomerular structure and function Blood inside the glomerulus has considerable hydrostatic pressure. The basement membrane has pores that will allow free diffusion of smaller solutes, larger negatively charged molecules such as albumin are unable to cross. The glomerular filtration rate (GFR) is equal to the concentration of a solute in the urine, times the volume of urine produced per minute, divided by the plasma concentration (assuming that the solute is freely diffused e.g. inulin). In clinical practice creatinine is used because it is subjected to very little proximal tubular secretion. Although subject to variability, the typical GFR is 125ml per minute. Glomerular filtration rate = Total volume of plasma per unit time leaving the capillaries and entering the bowman's capsule Renal clearance = volume plasma from which a substance is removed per minute by the kidneys Substances used to measure GFR have the following features: 1. Inert 2. Free filtration from the plasma at the glomerulus (not protein bound) 3. Not absorbed or secreted at the tubules 4. Plasma concentration constant during urine collection Examples: inulin, creatinine GFR = urine concentration (mmol/l) x urine volume (ml/min) -------------------------------------------------------------------------- plasma concentration (mmol/l) The clearance of a substance is dependent not only on its diffusivity across the basement membrane but also subsequent tubular secretion and / or reabsorption. So glucose which is freely filtered across the basement membrane is usually reabsorbed from tubules giving a clearance of zero. Tubular function Reabsorption and secretion of substances occurs in the tubules. In the proximal tubule substrates such as glucose, amino acids and phosphate are co-transported with sodium across the semi permeable membrane. Glucose is reabsorbed by both active and passive processes. The former uses sodiumâ€“glucose co-transporters (SGLTs) in the proximal convoluted tubule. The latter achieved through facilitated and passive process through GLUT transporters. Up to two thirds of filtered water is reabsorbed in the proximal tubules. This will lead to increase in urea concentration in the distal tubule allowing for its increased diffusion. Substances to be secreted into the tubules are taken up from the peritubular blood by tubular cells. Solutes such as paraaminohippuric acid are cleared with a single passage through the kidneys and this is why it is used to measure renal plasma flow. Ions such as calcium and phosphate will have a tubular reabsorption that is influenced by plasma PTH levels. Potassium may be both secreted and re-absorbed and is co-exchanged with sodium. Loop of Henle Approximately 60 litres of water containing 9000mmol sodium enters the descending limb of the loop of Henle in 24 hours. Loops from the juxtamedullary nephrons run deep into the medulla. The osmolarity of fluid changes and is greatest at the tip of the papilla. The thick ascending limb is impermeable to water, but highly permeable to sodium and chloride ions. This loss means that at the beginning of the thick ascending limb the fluid is hypo osmotic compared with adjacent interstitial fluid. In the thick ascending limb the reabsorption of sodium and chloride ions occurs by both facilitated and passive diffusion pathways. The loops of Henle are co-located with vasa recta, these will have similar solute compositions to the surrounding extracellular fluid so preventing the diffusion and subsequent removal of this hypertonic fluid. The energy dependent reabsorption of sodium and chloride in the thick ascending limb helps to maintain this osmotic gradient.

Answer 1753

The commonest site of metastatic breast cancer is to a bony site (often the axial skeleton) and so hypercalcaemia is often present in those with metastatic disease who are acutely unwell. Hypercalcaemia Main causes Malignancy (most common cause in hospital in-patients) Primary hyperparathyroidism (commonest cause in non hospitalised patients) Less common Sarcoidosis (extrarenal synthesis of calcitriol ) Thiazides, lithium Immobilisation Pagets disease Vitamin A/D toxicity Thyrotoxicosis MEN Milk alkali syndrome Clinical features Stones, bones, abdominal groans, and psychic moans High serum calcium levels result in decreased neuronal excitability. Therefore sluggish reflexes, muscle weakness and constipation may occur.

Answer 1754

In this setting Staphylococcus aureus Infection is the most likely cause. In the UK between 2010 and 2011 the commonest cause of wound infection was enterobacter infections (usually following cardiac or colonic surgery). 23% of infections were due to Staph aureus, which fits the scenario above. Infection with the other organisms including strep pyogenes was much rarer. Surgical site infection - Surgical site infections may occur following a breach in tissue surfaces and allow normal commensals and other pathogens to initiate infection. They are a major cause of morbidity and mortality. Surgical site infections (SSI) comprise up to 20% of all healthcare associated infections and at least 5% of patients undergoing surgery will develop an SSI as a result. In many cases the organisms are derived from the patient's own body. Measures that may increase the risk of SSI include: Shaving the wound using a razor (disposable clipper preferred) Using a non iodine impregnated incise drape if one is deemed to be necessary Tissue hypoxia Delayed administration of prophylactic antibiotics in tourniquet surgery Preoperatively Don't remove body hair routinely If hair needs removal, use electrical clippers with single use head (razors increase infection risk) Antibiotic prophylaxis if: - placement of prosthesis or valve - clean-contaminated surgery - contaminated surgery Use local formulary Aim to give single dose IV antibiotic on anaesthesia If a tourniquet is to be used, give prophylactic antibiotics earlier Intraoperatively Prepare the skin with alcoholic chlorhexidine (Lowest incidence of SSI) Cover surgical site with dressing A recent meta analysis has confirmed that administration of supplementary oxygen does not reduce the risk of wound infection. In contrast to previous individual RCT's(1) Wound edge protectors do not appear to confer benefit (2) Post operatively Tissue viability advice for management of surgical wounds healing by secondary intention Use of diathermy for skin incisions In the NICE guidelines the use of diathermy for skin incisions is not advocated(3). Several randomised controlled trials have been undertaken and demonstrated no increase in risk of SSI when diathermy is used(4). References 1. Brar M et al.. Perioperative supplemental oxygen in colorectal patients: a meta analysis. J Surg Res 2011 (166): 227 -235. 2. Pinkney T et al. Impact of wound edge protection devices on surgical site infection after laparotomy: impact of a multicentre randomised controlled trial (ROSSINI Trial). BMJ 2013 (347):10. 3. http://www.nice.org.uk/CG74 4. Ahmad N and Ahmed A. Meta-analysis of the effectiveness of surgical scalpel or diathermy in making abdominal skin incisions. Ann Surg 2011, 253(1):8-13.

Answer 1755

Mid cycle pain is very common and is due to the small amount of fluid released during ovulation. Inflammatory markers are usually normal and the pain typically subsides over the next 24-48 hours Gynaecological causes of abdominal pain A number of women will present with abdominal pain and subsequently be diagnosed with a gynaecological disorder. In addition to routine diagnostic work up of abdominal pain, all female patients should also undergo a bimanual vaginal examination, urine pregnancy test and consideration given to abdominal and pelvic ultrasound scanning. When diagnostic doubt persists a laparoscopy provides a reliable method of assessing suspected tubulo-ovarian pathology. Differential diagnoses of abdominal pain in females Diagnosis Features Investigation Treatment Mittelschmerz Usually mid cycle pain. Often sharp onset. Little systemic disturbance. May have recurrent episodes. Usually settles over 24-48 hours. Full blood count- usually normal Ultrasound- may show small quantity of free fluid Conservative Endometriosis 25% asymptomatic, in a further 25% associated with other pelvic organ pathology. Remaining 50% may have menstrual irregularity, infertility, pain and deep dyspareunia. Complex disease may result in pelvic adhesional formation with episodes of intermittent small bowel obstruction. Intra-abdominal bleeding may produce localised peritoneal inflammation. Recurrent episodes are common. Ultrasound- may show free fluid Laparoscopy will usually show lesions Usually managed medically, complex disease will often require surgery and some patients will even require formal colonic and rectal resections if these areas are involved Ovarian torsion Usually sudden onset of deep seated colicky abdominal pain. Associated with vomiting and distress. Vaginal examination may reveal adnexial tenderness. Ultrasound may show free fluid Laparoscopy is usually both diagnostic and therapeutic Laparoscopy Ectopic gestation Symptoms of pregnancy without evidence of intra uterine gestation. Present as an emergency with evidence of rupture or impending rupture. Open tubular ruptures may have sudden onset of abdominal pain and circulatory collapse, in other the symptoms may be more prolonged and less marked. Small amount of vaginal discharge is common. There is usually adnexial tenderness. Ultrasound showing no intra uterine pregnancy and beta HCG that is elevated May show intra abdominal free fluid Laparoscopy or laparotomy is haemodynamically unstable. A salphingectomy is usually performed. Pelvic inflammatory disease Bilateral lower abdominal pain associated with vaginal discharge. Dysuria may also be present. Peri-hepatic inflammation secondary to Chlamydia (Fitz Hugh Curtis Syndrome) may produce right upper quadrant discomfort. Fever >38o Full blood count- Leucocytosis Pregnancy test negative (Although infection and pregnancy may co-exist) Amylase - usually normal or slightly raised High vaginal and urethral swabs

Answer 1756

Silver nitrate will cauterise the exuberant granulation tissue and promote healing. Methods of wound closure Method of closure Indication Primary closure Clean wound, usually surgically created or following minor trauma Standard suturing methods will usually suffice Wound heals by primary intention Delayed primary closure Similar methods of actual closure to primary closure May be used in situations where primary closure is either not achievable or not advisable e.g. infection Vacuum assisted closure Uses negative pressure therapy to facilitate wound closure Sponge is inserted into wound cavity and then negative pressure applied Advantages include removal of exudate and versatility Disadvantages include cost and risk of fistulation if used incorrectly on sites such as bowel Split thickness skin grafts Superficial dermis removed with Watson knife or dermatome (commonly from thigh) Remaining epithelium regenerates from dermal appendages Coverage may be increased by meshing Full thickness skin grafts Whole dermal thickness is removed Sub dermal fat is then removed and graft placed over donor site Better cosmesis and flexibility at recipient site Donor site morbidity Flaps Viable tissue with a blood supply May be pedicled or free Pedicled flaps are more reliable, but limited in range Free flaps have greater range but carry greater risk of breakdown as they require vascular anastomosis

Answer 1757

Compression of the thoracic outlet by the fibrous band of the rib can result in both neurological and circulatory compromise. When manual tasks are performed in which the hand works overhead the signs and symptoms will be maximal and this is the basis of Adsons test. Vascular disorders of the upper limb Upper limb arterial disease is less common than lesions causing symptoms in the lower limb. The upper limb circulation may be affected by embolic events, stenotic lesions (both internal and extrinsic), inflammatory disorders and venous diseases. The anatomy of the collateral circulation of the arterial inflow may impact on the history and nature of disease presentation. In the region of the subclavian and axillary arteries the collateral vessels passing around the shoulder joint may provide pathways for flow if the main vessels are stenotic or occluded. During periods of increased metabolic demand the collateral flow is not sufficient and the vertebral arteries may have diminished flow. This may result in diminished flow to the brain with neurological sequelae such as syncope. Vascular disease of the upper limb Condition Features Axillary/ brachial embolus 50% of upper limb emboli will lodge in the brachial artery 30% of upper limb emboli will lodge in the axillary artery Sudden onset of symptoms; pain, pallor, paresis, pulselessness, paraesthesia Sources are left atrium with cardiac arrhythmia (mainly AF), mural thrombus Cardiac arrhythmias may result in impaired consciousness in addition to the embolus Arterial occlusions Those resulting from atheroma are the most common, trauma may result in vascular changes and long term occlusion but this is rare Features may include claudication, ulceration and gangrene. Proximally sited lesions may result in subclavian steal syndrome The progressive nature of the disease allows development of collaterals, acute ischaemia may occur as a result of acute thrombosis Raynaud's disease Idiopathic condition affecting young females Usually affects hands > feet Digits become: white →blue →red Treatment is with calcium antagonists Upper limb venous thrombosis Gradual onset of upper limb swelling and discomfort. Sensation and motor function are normal Condition may complicate pre-existing malignancy (especially breast cancer) or arise as a result of repetitive use of the limb in a task such as painting a ceiling The condition is diagnosed with duplex ultrasound and treatment is with anticoagulation Cervical rib 0.2-0.4% incidence Consist of an anomalous fibrous band that often originates from C7 and may arc towards, but rarely reaches the sternum Congenital cases may present around the third decade, some cases are reported to occur following trauma Bilateral in up to 70% Compression of the subclavian artery may produce absent radial pulse on clinical examination and in particular may result in a positive Adsons test (lateral flexion of the neck away from symptomatic side and traction of the symptomatic arm- leads to obliteration of radial pulse) Treatment is most commonly undertaken when there is evidence of neurovascular compromise. A transaxillary approach is the traditional operative method for excision

Answer 1758

The annual probability of strangulation is up to 3% and is more common in indirect hernias. Elective repair poses few risks. However, emergency repair is associated with increased mortality, particularly in the elderly. Inguinal hernia surgery Inguinal hernias occur when the abdominal viscera protrude through the anterior abdominal wall into the inguinal canal. They may be classified as being either direct or indirect. The distinction between these two rests on their relation to Hesselbach's triangle. Boundaries of Hesselbach's Triangle Medial: Rectus abdominis Lateral: Inferior epigastric vessels Inferior: Inguinal ligament Hernias occurring within the triangle tend to be direct and those outside - indirect. Diagnosis Most cases are diagnosed clinically, a reducible swelling may be located at the level of the inguinal canal. Large hernia's may extend down into the male scrotum, these will not trans-illuminate and it is not possible to 'get above' the swelling. Cases that are unclear on examination, but suspected from the history, may be further investigated using ultrasound or by performing a herniogram. Treatment Hernias associated with few symptoms may be managed conservatively. Symptomatic hernias or those which are at risk of developing complications are usually treated surgically. First time hernias may be treated by performing an open inguinal hernia repair; the inguinal canal is opened, the hernia reduced and the defect repaired. A prosthetic mesh may be placed posterior to the cord structures to re-enforce the repair and reduce the risk of recurrence. Recurrent hernias and those which are bilateral are generally managed with a laparoscopic approach. This may be via an intra or extra peritoneal route. As in open surgery a mesh is deployed. However, it will typically lie posterior to the deep ring. Inguinal hernia in children Inguinal hernias in children are almost always of an indirect type and therefore are usually dealt with by herniotomy, rather than herniorraphy. Neonatal hernias especially in those children born prematurely are at highest risk of strangulation and should be repaired urgently. Other hernias may be repaired on an elective basis. References The UK Based National Institute of Clinical Excellence has published guidelines relating to the choice between open and laparoscopic inguinal hernia repair. Which users may find interesting: http://guidance.nice.org.uk/TA83/Guidance/pdf/English

Answer 1759

50% of plasma calcium is ionised. Hyperventilation will induce a state of alkalosis which will lower ionised plasma calcium levels. Calcium homeostasis Calcium ions are linked to a wide range of physiological processes. The largest store of bodily calcium is contained within the skeleton. Calcium levels are primarily controlled by parathyroid hormone, vitamin D and calcitonin. Hormonal regulation of calcium Hormone Actions Parathyroid hormone (PTH) Increase calcium levels and decrease phosphate levels Increases bone resorption Immediate action on osteoblasts to increase ca2+ in extracellular fluid Osteoblasts produce a protein signaling molecule that activate osteoclasts which cause bone resorption Increases renal tubular reabsorption of calcium Increases synthesis of 1,25(OH)2D (active form of vitamin D) in the kidney which increases bowel absorption of Ca2+ Decreases renal phosphate reabsorption 1,25-dihydroxycholecalciferol (the active form of vitamin D) Increases plasma calcium and plasma phosphate Increases renal tubular reabsorption and gut absorption of calcium Increases osteoclastic activity at high levels and osteoblasts at low levels Increases renal phosphate reabsorption Calcitonin Secreted by C cells of thyroid Inhibits intestinal calcium absorption Inhibits osteoclast activity Inhibits renal tubular absorption of calcium Both growth hormone and thyroxine also play a small role in calcium metabolism.

Answer 1760

APC mutations are found in familial adenomatous polyposis coli. These have multiple colonic adenomas. Polyposis syndromes Syndrome Genetic defect Features Screening and management Associated disorders Familial adenomatous polyposis Mutation of APC gene (80%) cases, dominant Typically over 100 colonic adenomas Cancer risk of 100% 20% are new mutations If known to be at risk then predictive genetic testing as teenager Annual flexible sigmoidoscopy from 15 years If no polyps found then 5 yearly colonoscopy started at age 20 Polyps found = resectional surgery (resection and pouch Vs sub total colectomy and IRA) Gastric fundal polyps (50%). Duodenal polyps 90%. If severe duodenal polyposis cancer risk of 30% at 10 years. Abdominal desmoid tumours. MYH associated polyposis Biallelic mutation of mut Y human homologue (MYH) on chromosome 1p, recessive Multiple colonic polyps Later onset right sided cancers more common than in FAP 100% cancer risk by age 60 Once identified resection and ileoanal pouch reconstruction is recommended Attenuated phenotype - regular colonoscopy Duodenal polyposis in 30% Associated with increased risk of breast cancer (self examination) Peutz -Jeghers syndrome STK11 (LKB1) mutation on chromosome 19 in some (but not all) cases, dominant Multiple benign intestinal hamartomas Episodic obstruction and intussceception Increased risk of GI cancers (colorectal cancer 20%, gastric 5%) Increased risk of breast, ovarian, cervical pancreatic and testicular cancers Annual examination Pan intestinal endoscopy every 2-3 years Malignancies at other sites Classical pigmentation pattern Cowden disease Mutation of PTEN gene on chromosome 10q22, dominant Macrocephaly Multiple intestinal hamartomas Multiple trichilemmomas 89% risk of cancer at any site 16% risk of colorectal cancer Targeted individualised screening Breast cancer (81% risk) Thyroid cancer and non toxic goitre Uterine cancer HNPCC (Lynch syndrome) Germline mutations of DNA mismatch repair genes Colo rectal cancer 30-70% Endometrial cancer 30-70% Gastric cancer 5-10% Scanty colonic polyps may be present Colonic tumours likely to be right sided and mucinous Colonoscopy every 1-2 years from age 25 Consideration of prophylactic surgery Extra colonic surveillance recommended Extra colonic cancers

Answer 1761

The long head arises from the infraglenoid tubercle. The fleshy lateral and medial heads are attached to the posterior aspect of the humerus between the insertion of the teres minor and the olecranon fossa. Triceps Origin Long head- infraglenoid tubercle of the scapula. Lateral head- dorsal surface of the humerus, lateral and proximal to the groove of the radial nerve Medial head- posterior surface of the humerus on the inferomedial side of the radial groove and both of the intermuscular septae Insertion Olecranon process of the ulna. Here the olecranon bursa is between the triceps tendon and olecranon. Some fibres insert to the deep fascia of the forearm, posterior capsule of the elbow (preventing the capsule from being trapped between olecranon and olecranon fossa during extension) Innervation Radial nerve Blood supply Profunda brachii artery Action Elbow extension. The long head can adduct the humerus and extend it from a flexed position Relations The radial nerve and profunda brachii vessels lie between the lateral and medial heads

Answer 1762

The normal intracranial pressure is between 7 and 15 mm Hg. The brain can accommodate increases up to 24 mm Hg, thereafter clinical features will become evident. Applied neurophysiology Pressure within the cranium is governed by the Monroe-Kelly doctrine. This considers the skull as a closed box. Increases in mass can be accommodated by loss of CSF. Once a critical point is reached (usually 100- 120ml of CSF lost) there can be no further compensation and ICP rises sharply. The next step is that pressure will begin to equate with MAP and neuronal death will occur. Herniation will also accompany this process. The CNS can autoregulate its own blood supply. Vaso constriction and dilatation of the cerebral blood vessels is the primary method by which this occurs. Extremes of blood pressure can exceed this capacity resulting in risk of stroke. Other metabolic factors such as hypercapnia will also cause vasodilation, which is of importance in ventilating head injured patients. The brain can only metabolise glucose, when glucose levels fall, consciousness will be impaired.

Answer 1763

Early plain x-ray changes in Perthes Disease: Widening of the joint space. Sub chondral linear lucency. This is a typical presentation for Perthes disease. X-ray may show flattening of the femoral head or fragmentation in more advanced cases. Paediatric orthopaedics Diagnosis Mode of presentation Treatment Radiology Developmental dysplasia of the hip Usually diagnosed in infancy by screening tests. May be bilateral, when disease is unilateral there may be leg length inequality. As disease progresses child may limp and then early onset arthritis. More common in extended breech babies. Splints and harnesses or traction. In later years osteotomy and hip realignment procedures may be needed. In arthritis a joint replacement may be needed. However, this is best deferred if possible as it will almost certainly require revision Initially no obvious change on plain films and USS gives best resolution until 3 months of age. On plain films Shentons line should form a smooth arc Perthes Disease Hip pain (may be referred to the knee) usually occurring between 5 and 12 years of age. Bilateral disease in 20%. Remove pressure from joint to allow normal development. Physiotherapy. Usually self-limiting if diagnosed and treated promptly. X-rays will show flattened femoral head. Eventually in untreated cases the femoral head will fragment. Slipped upper femoral epiphysis Typically seen in obese male adolescents. Pain is often referred to the knee. Limitation to internal rotation is usually seen. Knee pain is usually present 2 months prior to hip slipping. Bilateral in 20%. Bed rest and non-weight bearing. Aim to avoid avascular necrosis. If severe slippage or risk of it occurring then percutaneous pinning of the hip may be required. X-rays will show the femoral head displaced and falling inferolaterally (like a melting ice cream cone) The Southwick angle gives indication of disease severity

Answer 1764

The radial nerve lies anterolateral to the humerus in the supracondylar area. Radial nerve Continuation of posterior cord of the brachial plexus (root values C5 to T1) Path In the axilla: lies posterior to the axillary artery on subscapularis, latissimus dorsi and teres major. Enters the arm between the brachial artery and the long head of triceps (medial to humerus). Spirals around the posterior surface of the humerus in the groove for the radial nerve. At the distal third of the lateral border of the humerus it then pierces the intermuscular septum and descends in front of the lateral epicondyle. At the lateral epicondyle it lies deeply between brachialis and brachioradialis where it then divides into a superficial and deep terminal branch. Deep branch crosses the supinator to become the posterior interosseous nerve. Regions innervated Motor (main nerve) Triceps Anconeus Brachioradialis Extensor carpi radialis Motor (posterior interosseous branch) Supinator Extensor carpi ulnaris Extensor digitorum Extensor indicis Extensor digiti minimi Extensor pollicis longus and brevis Abductor pollicis longus Sensory The area of skin supplying the proximal phalanges on the dorsal aspect of the hand is supplied by the radial nerve (this does not apply to the little finger and part of the ring finger) Muscular innervation and effect of denervation Anatomical location Muscle affected Effect of paralysis Shoulder Long head of triceps Minor effects on shoulder stability in abduction Arm Triceps Loss of elbow extension Forearm Supinator Brachioradialis Extensor carpi radialis longus and brevis Weakening of supination of prone hand and elbow flexion in mid prone position

Answer 1765

Lymphatic drainage of the tongue - The lymphatic drainage of the anterior two thirds of the tongue shows only minimal communication of lymphatics across the midline, so metastasis to the ipsilateral nodes is usual. The lymphatic drainage of the posterior third of the tongue have communicating networks, as a result early bilateral nodal metastases are more common in this area. Lymphatics from the tip of the tongue usually pass to the sub mental nodes and from there to the deep cervical nodes. Lymphatics from the mid portion of the tongue usually drain to the submandibular nodes and then to the deep cervical nodes. Mid tongue tumours that are laterally located will usually drain to the ipsilateral deep cervical nodes, those from more central regions may have bilateral deep cervical nodal involvement.

Answer 1766

This is the site for a spigelian hernia. Hernia Hernias occur when a viscus or part of it protrudes from within its normal anatomical cavity. Specific hernias are covered under their designated titles the remainder are addressed here. Spigelian hernia Interparietal hernia occurring at the level of the arcuate line Rare May lie beneath internal oblique muscle. Usually between internal and external oblique Equal sex distribution Position is lateral to rectus abdominis Both open and laparoscopic repair are possible, the former in cases of strangulation Lumbar hernia The lumbar triangle (through which these may occur) is bounded by: Crest of ilium (inferiorly) External oblique (laterally) Latissimus dorsi (medially) Primary lumbar herniae are rare, most are incisional hernias following renal surgery - Direct anatomical repair with or without mesh re-enforcement is the procedure of choice Obturator hernia Herniation through the obturator canal Commoner in females Usually lies behind pectineus muscle Elective diagnosis is unusual most will present acutely with obstruction When presenting acutely most cases with require laparotomy or laparoscopy (and small bowel resection if indicated) Richters hernia Condition in which part of the wall of the small bowel (usually the anti mesenteric border) is strangulated within a hernia (of any type) They do not present with typical features of intestinal obstruction as lumenal patency is preserved Where vomiting is prominent it usually occurs as a result of paralytic ileus from peritonitis (as these hernias may perforate) Incisional hernia Occur through sites of surgical access into the abdominal cavity Most common following surgical wound infection To minimise following midline laparotomy Jenkins Rule should be followed and this necessitates a suture length 4x length of incision with bites taken at 1cm intervals, 1 cm from the wound edge Repair may be performed either at open surgery or laparoscopically and a wide variety of techniques are described Bochdalek hernia Typically congenital diaphragmatic hernia 85% cases are located in the left hemi diaphragm Associated with lung hypoplasia on the affected side More common in males Associated with other birth defects May contain stomach May be treated by direct anatomical apposition or placement of mesh. In infants that have severe respiratory compromise mechanical ventilation may be needed and mortality rate is high Morgagni Hernia Rare type of diaphragmatic hernia (approx 2% cases) Herniation through foramen of Morgagni Usually located on the right and tend to be less symptomatic More advanced cases may contain transverse colon As defects are small pulmonary hypoplasia is less common Direct anatomical repair is performed Umbilical hernia Hernia through weak umbilicus Usually presents in childhood Often symptomatic Equal sex incidence 95% will resolve by the age of 2 years Surgery performed after the third birthday Paraumbilical hernia Usually a condition of adulthood Defect is in the linea alba More common in females Multiparity and obesity are risk factors Traditionally repaired using Mayos technique - overlapping repair, mesh may be used though not if small bowel resection is required owing to acute strangulation Littres hernia Hernia containing Meckels diverticulum Resection of the diverticulum is usually required and this will preclude a mesh repair

Answer 1767

In a young patient consideration should be given to aorto-bifemoral bypass grafts as these have the best long term functional outcome compared with an axillo-bifemoral bypass graft. Peripheral vascular disease Indications for surgery to revascularise the lower limb Intermittent claudication Critical ischaemia Ulceration Gangrene Intermittent claudication that is not disabling may provide a relative indication, whilst the other complaints are often absolute indications depending upon the frailty of the patient. Assessment Clinical examination Ankle brachial pressure index measurement Duplex arterial ultrasound Angiography (standard, CT or MRI): usually performed only if intervention being considered. Angioplasty In order for angioplasty to be undertaken successfully the artery has to be accessible. The lesion relatively short and reasonable distal vessel runoff. Longer lesions may be amenable to sub-intimal angioplasty. Surgery Surgery will be undertaken where attempts at angioplasty have either failed or are unsuitable. Bypass essentially involves bypassing the affected arterial segment by utilising a graft to run from above the disease to below the disease. As with angioplasty good runoff improves the outcome. Some key concepts with bypass surgery Superficial femoral artery occlusion to the above knee popliteal In the ideal scenario, vein (either in situ or reversed LSV) would be used as a conduit. However, prosthetic material has reasonable 5 year patency rates and some would advocate using this in preference to vein so that vein can be used for other procedures in the future. In general terms either technique is usually associated with an excellent outcome (if run off satisfactory). Procedure Artery dissected out, IV heparin 3,000 units given and then the vessels are cross clamped Longitudinal arteriotomy Graft cut to size and tunneled to arteriotomy sites Anastomosis to femoral artery usually with 5/0 'double ended' Prolene suture Distal anastomosis usually using 6/0 'double ended' Prolene Distal disease Femoro-distal bypass surgery takes longer to perform, is more technically challenging and has higher failure rates. In elderly diabetic patients with poor runoff a primary amputation may well be a safer and more effective option. There is no point in embarking on this type of surgery in patients who are wheelchair bound. In femorodistal bypasses vein gives superior outcomes to PTFE. Rules Vein mapping 1st to see whether there is suitable vein (the preferred conduit). Sub intimal hyperplasia occurs early when PTFE is used for the distal anastomosis and will lead to early graft occlusion and failure. Essential operative procedure as for above knee fem-pop. If there is insufficient vein for the entire conduit then vein can be attached to the end of the PTFE graft and then used for the distal anastomosis. This type of 'vein boot' is technically referred to as a Miller Cuff and is associated with better patency rates than PTFE alone. Remember the more distal the arterial anastomosis the lower the success rate. References Peach G et al. Diagnosis and management of peripheral arterial disease. BMJ 2012; 345: 36-41.

Answer 1768

Displaced apex beat and decreased air entry are suggestive of diaphragmatic hernia. The abdomen may well be scaphoid in some cases. The underlying lung may be hypoplastic and this correlates directly with prognosis. Paediatric Gastrointestinal disorders Pyloric stenosis M>F 5-10% Family history in parents Projectile non bile stained vomiting at 4-6 weeks of life Diagnosis is made by test feed or USS Treatment: Ramstedt pyloromyotomy (open or laparoscopic) Acute appendicitis Uncommon under 3 years When occurs may present atypically Mesenteric adenitis Central abdominal pain and URTI Conservative management Intussusception Telescoping bowel Proximal to or at the level of, ileocaecal valve 6-9 months age Colicky pain, diarrhoea and vomiting, sausage shaped mass, red jelly stool. Treatment: reduction with air insufflation Malrotation High caecum at the midline Feature in exomphalos, congenital diaphragmatic hernia, intrinsic duodenal atresia May be complicated by development of volvulus, infant with volvulus may have bile stained vomiting Diagnosis is made by upper GI contrast study and USS Treatment is by laparotomy, if volvulus is present (or at high risk of occurring then a ladds procedure is performed Hirschsprung's disease Absence of ganglion cells from myenteric and submucosal plexuses Occurs in 1/5000 births Full thickness rectal biopsy for diagnosis Delayed passage of meconium and abdominal distension Treatment is with rectal washouts initially, thereafter an anorectal pull through procedure Oesophageal atresia Associated with tracheo-oesophageal fistula and polyhydramnios May present with choking and cyanotic spells following aspiration VACTERL associations Meconium ileus Usually delayed passage of meconium and abdominal distension Majority have cystic fibrosis X-Rays may not show a fluid level as the meconium is viscid (depends upon feeding), PR contrast studies may dislodge meconium plugs and be therapeutic Infants who do not respond to PR contrast and NG N-acetyl cysteine will require surgery to remove the plugs Biliary atresia Jaundice > 14 days Increased conjugated bilirubin Urgent Kasai procedure Necrotising enterocolitis Prematurity is the main risk factor Early features include abdominal distension and passage of bloody stools X-Rays may show pneumatosis intestinalis and evidence of free air Increased risk when empirical antibiotics are given to infants beyond 5 days Treatment is with total gut rest and TPN, babies with perforations will require laparotomy

Answer 1769

The diaphragm is the major muscle involved in this process and it is for this reason that diminished activity following major abdominal surgery (note surgery type not specified here) can result in atelectasis. Alveolar ventilation - Minute ventilation is the total volume of gas ventilated per minute. MV (ml/min)= tidal volume x Respiratory rate (resps/min). Dead space ventilation describes the volume of gas not involved in exchange in the blood. There are 2 types: 1. Anatomical dead space: 150mls Volume of gas in the respiratory tree not involved in gaseous exchange: mouth, pharynx, trachea, bronchi up to terminal bronchioles Measured by Fowlers method Increased by: Standing, increased size of person, increased lung volume and drugs causing bronchodilatation e.g. Adrenaline 2. Physiological dead space: normal 150 mls, increases in ventilation/perfusion mismatch e.g. PE, COPD, hypotension Volume of gas in the alveoli and anatomical dead space not involved in gaseous exchange. Alveolar ventilation is the volume of fresh air entering the alveoli per minute. Alveolar ventilation = minute ventilation - Dead space volume

Answer 1770

Adductor canal compression syndrome most commonly presents in young males and is an important differential diagnosis in men presenting with symptoms of acute limb ischaemia on exertion. It is caused by compression of the femoral artery by the musculotendinous band from adductor magnus muscle. The treatment consists of the division of the abnormal band and restoration of the arterial circulation. Popliteal fossa entrapment is the main differential diagnosis, however the pulse disappears when the knee is fully extended. Adductor canal Also called Hunter's or subsartorial canal Immediately distal to the apex of the femoral triangle, lying in the middle third of the thigh. Canal terminates at the adductor hiatus. Borders Contents Laterally Vastus medialis muscle Saphenous nerve Posteriorly Adductor longus, adductor magnus Superficial femoral artery Roof Sartorius Superficial femoral vein

Answer 1771

Via the coronary sinus Persistent left superior vena cava is the most common anomaly of the thoracic venous system. It is prevalent in 0.3% of the population and is a benign entity of failed involution during embryogenesis. Superior vena cava Drainage Head and neck Upper limbs Thorax Part of abdominal walls Formation Subclavian and internal jugular veins unite to form the right and left brachiocephalic veins These unite to form the SVC Azygos vein joins the SVC before it enters the right atrium Relations Anterior Anterior margins of the right lung and pleura Posteromedial Trachea and right vagus nerve Posterolateral Posterior aspects of right lung and pleura Pulmonary hilum is posterior Right lateral Right phrenic nerve and pleura Left lateral Brachiocephalic artery and ascending aorta Developmental variations Anomalies of the connection of the SVC are recognised. In some individuals a persistent left sided SVC drains into the right atrium via an enlarged orifice of the coronary sinus. More rarely the left sided vena cava may connect directly with the superior aspect of the left atrium, usually associated with an un-roofing of the coronary sinus. The commonest lesion of the IVC is for its abdominal course to be interrupted, with drainage achieved via the azygos venous system. This may occur in patients with left sided atrial isomerism.

Answer 1772

In the UK, the GMC and common law advises that emergency life saving treatment can be given to a child irrespective of the parents views. There is clearly insufficient time here to apply to a court. Consent There are 3 types of consent: 1. Informed 2. Expressed 3. Implied Consent forms used in UK NHS Consent Form 1 For competent adults who are able to consent for themselves where consciousness may be impaired (e.g. GA) Consent Form 2 For an adult consenting on behalf of a child where consciousness is impaired Consent Form 3 For an adult or child where consciousness is not impaired Consent Form 4 For adults who lack capacity to provide informed consent Capacity Key points include: 1. Understand and retain information 2. Patient believes the information to be true 3. Patient is able to weigh the information to make a decision All patients must be assumed to have capacity Consent in minors Young children and older children who are not Gillick competent cannot consent for themselves. In British law the patients biological mother can always provide consent. The child's father can consent if the parents are married (and the father is the biological father), or if the father is named on the birth certificate (irrespective of marital status). If parents are not married and the father is not named on the birth certificate then the father cannot consent.

Answer 1773

Fibrosis is usually a sign of chronic ulcer. It should be biopsied carefully, a proton pump inhibitor started and re endoscopy should occur at 6 weeks. Upper gastrointestinal bleeding Patients may present with the following: Haematemesis and/ or malaena Epigastric discomfort Sudden collapse The extent to which these will occur will depend upon the source. Mortality is higher in patients presenting with haematemesis than malaena alone. Oesophageal bleeding Cause Presenting features Oesophagitis Small volume of fresh blood, often streaking vomit. Malaena rare. Often ceases spontaneously. Usually history of antecedent GORD type symptoms. Cancer Usually small volume of blood, except as pre terminal event with erosion of major vessels. Often associated symptoms of dysphagia and constitutional symptoms such as weight loss. May be recurrent until malignancy managed. Mallory Weiss Tear Typically brisk small to moderate volume of bright red blood following bout of repeated vomiting. Malaena rare. Usually ceases spontaneously. Varices Usually large volume of fresh blood. Swallowed blood may cause malaena. Often associated with haemodynamic compromise. May stop spontaneously but re-bleeds are common until appropriately managed. Gastric Bleeding Cause Presenting features Gastric cancer May be frank haematemesis or altered blood mixed with vomit. Usually prodromal features of dyspepsia and may have constitutional symptoms. Amount of bleeding variable but erosion of major vessel may produce considerable haemorrhage. Dieulafoy Lesion Often no prodromal features prior to haematemesis and malaena, but this arteriovenous malformation may produce quite considerable haemorrhage and may be difficult to detect endoscopically. Diffuse erosive gastritis Usually haematemesis and epigastric discomfort. Usually there is an underlying cause such as recent NSAID usage. Large volume haemorrhage may occur with considerable haemodynamic compromise. Gastric ulcer Small low volume bleeds more common so would tend to present as iron deficiency anaemia. Erosion into a significant vessel may produce considerable haemorrhage and haematemesis. Duodenum Most common cause of major haemorrhage is a posteriorly sited duodenal ulcer. However, ulcers at any site in the duodenum may present with haematemesis, malaena and epigastric discomfort. The pain of duodenal ulcer is slightly different to that of gastric ulcers and often occurs several hours after eating. Peri ampullary tumours may bleed but these are rare. In patients with previous abdominal aortic aneurysm surgery aorto-enteric fistulation remains a rare but important cause of major haemorrhage associated with high mortality. Management Admission to hospital careful monitoring, cross match blood, check FBC, LFTs, U+E and Clotting (as a minimum) Patients with on-going bleeding and haemodynamic instability are likely to require O negative blood pending cross matched blood Early control of airway is vital (e.g. Drowsy patient with liver failure) Patients with suspected varices should receive terlipressin prior to endoscopy Ideally all patients admitted with upper gastrointestinal haemorrhage should undergo Upper GI endoscopy within 24 hours of admission. In those who are unstable this should occur immediately after resuscitation or in tandem with it. The endoscopy department is a potentially dangerous place for unstable patients and it may be safer to perform the endoscopy in theatre with an anaesthetist present. Varices should be banded or subjected to sclerotherapy. If this is not possible owing to active bleeding then a Sengstaken- Blakemore tube (or Minnesota tube) should be inserted. This should be done with care; gastric balloon should be inflated first and oesophageal balloon second. Remember the balloon will need deflating after 12 hours (ideally sooner) to prevent necrosis. Portal pressure should be lowered by combination of medical therapy +/- TIPSS. Patients with erosive oesophagitis / gastritis should receive a proton pump inhibitor. Mallory Weiss tears will typically resolve spontaneously Identifiable bleeding points should receive combination therapy of injection of adrenaline and either a thermal or mechanical treatment. All who have received intervention should receive a continuous infusion of a proton pump inhibitor (IV omeprazole for 72 hours) to reduce the re-bleeding rate. Patients with diffuse erosive gastritis who cannot be managed endoscopically and continue to bleed may require gastrectomy Bleeding ulcers that cannot be controlled endoscopically may require laparotomy and ulcer underruning Indications for surgery Patients > 60 years Continued bleeding despite endoscopic intervention Recurrent bleeding Known cardiovascular disease with poor response to hypotension Surgery Duodenal ulcer Laparotomy, duodenotomy and under running of the ulcer. If bleeding is brisk then the ulcer is almost always posteriorly sited and will have invaded the gastroduodenal artery. Large bites using 0 Vicryl are taken above and below the ulcer base to occlude the vessel. The duodenotomy should be longitudinal but closed transversely to avoid stenosis. For gastric ulcer Under-running of the bleeding site Partial gastrectomy-antral ulcer Partial gastrectomy or under running the ulcer- lesser curve ulcer (involving left gastric artery) Total gastrectomy if bleeding persists Summary of Acute Upper GI bleeding recommendations: The need for admission and timing of endoscopic intervention may be predicted by using the Blatchford score. This considers a patients Hb, serum urea, pulse rate and blood pressure. Those patients with a score of 0 are low risk, all others are considered high risk and require admission and endoscopy. The requirement for pre endoscopic proton pump inhibition is contentious. In the UK the National Institute of Clinical Excellence guidelines suggest the pre endoscopic PPI therapy is unnecessary. Whilst it is accepted that such treatment has no impact on mortality or morbidity a Cochrane review of this practice in 2007 did suggest that it reduced the stigmata of recent haemorrhage at endoscopy. As a result many will still administer PPI to patients prior to endoscopic intervention. Following endoscopy it is important to calculate the Rockall score for patients to determine their risk of rebleeding and mortality. A score of 3 or less is associated with a rebleeding rate of 4% and a very low risk of mortality and identifies a group of patients suitable for early discharge. References 1. http://www.sign.ac.uk/guidelines/fulltext/105/index.html 2. Joint Advisory Group on Endoscopy (JAG) Guidelines - http://www.thejag.org.uk 3. NICE Guideline: Management of acute upper GI bleeding. July 2012.

Answer 1774

The hyperventilation results in decreased carbon dioxide levels, causing a respiratory alkalosis (non compensated).

Answer 1775

Collagen has a generic structure of Glycine- X- Y, where X and Y are variable sub units. The relatively small size of the glycine molecule enables collagen to form a tight helical structure. Collagen Collagen is one of the most important structural proteins within the extracellular matrix, collagen together with components such as elastin and glycosaminoglycans determine the properties of all tissues. Composed of 3 polypeptide strands that are woven into a helix, usually a combination of glycine with either proline or hydroxyproline plus another amino acid Numerous hydrogen bonds exist within molecule to provide additional strength Many sub types but commonest sub type is I (90% of bodily collagen), tissues with increased levels of flexibility have increased levels of type III collagen Vitamin c is important in establishing cross links Synthesised by fibroblasts Collagen Diseases Disorders of collagen range from relatively common, acquired defects (typically aging), through to rarer congenital disorders. The latter are exemplified by conditions such as osteogenesis imperfecta and Ehlers Danlos syndromes. Osteogenesis imperfecta: -8 Subtypes -Defect of type I collagen -In type I the collagen is normal quality but insufficient quantity -Type II- poor quantity and quality -Type III- Collagen poorly formed, normal quantity -Type IV- Sufficient quantity but poor quality Patients have bones which fracture easily, loose joint and multiple other defects depending upon which sub type they suffer from. Ehlers Danlos: -Multiple sub types -Abnormality of types 1 and 3 collagen -Patients have features of hypermobility. -Individuals are prone to joint dislocations and pelvic organ prolapse. In addition to many other diseases related to connective tissue defects.

Answer 1776

The process of starvation may lower DPG levels, in practice this is unlikely to occur early as it is generated during glycolysis. Altered metabolism in starvation may be more acidotic and this would also tend to impair oxygen carriage. Nutrition - Refeeding syndrome Refeeding syndrome describes the metabolic abnormalities which occur on feeding a person following a period of starvation. The metabolic consequences include: Hypophosphataemia Hypokalaemia Hypomagnesaemia Abnormal fluid balance These abnormalities can lead to organ failure. Re-feeding problems If patient not eaten for > 5 days, aim to re-feed at < 50% energy and protein levels High risk for re-feeding problems If one or more of the following: BMI < 16 kg/m2 Unintentional weight loss >15% over 3-6 months Little nutritional intake > 10 days Hypokalaemia, Hypophosphataemia or hypomagnesaemia prior to feeding (unless high) If two or more of the following: BMI < 18.5 kg/m2 Unintentional weight loss > 10% over 3-6 months Little nutritional intake > 5 days History of: alcohol abuse, drug therapy including insulin, chemotherapy, diuretics and antacids Prescription Start at up to 10 kcal/kg/day increasing to full needs over 4-7 days Start immediately before and during feeding: oral thiamine 200-300mg/day, vitamin B co strong 1 tds and supplements Give K+ (2-4 mmol/kg/day), phosphate (0.3-0.6 mmol/kg/day), magnesium (0.2-0.4 mmol/kg/day)

Answer 1777

The contents of the popliteal fossa are (from medial to lateral): Popliteal artery Popliteal vein Tibial nerve Common peroneal nerve The sural nerve is a branch of the tibial nerve and usually arises at the inferior aspect of the popliteal fossa. However, its anatomy is variable. Popliteal fossa Boundaries of the popliteal fossa Laterally Biceps femoris above, lateral head of gastrocnemius and plantaris below Medially Semimembranosus and semitendinosus above, medial head of gastrocnemius below Floor Popliteal surface of the femur, posterior ligament of knee joint and popliteus muscle Roof Superficial and deep fascia Contents Popliteal artery and vein Small saphenous vein Common peroneal nerve Tibial nerve Posterior cutaneous nerve of the thigh Genicular branch of the obturator nerve Lymph nodes

Answer 1778

Pleomorphic adenoma of the parotid= surgical excision Pleomorphic adenomas a usually benign tumours. However, they will enlarge over time and a proportion can undergo malignant transformation. Therefore, all pleomorphic adenomas are excised and a superficial parotidectomy is generally the procedure of choice. The facial nerve is preserved. More recently, there has been a move towards partial superficial parotidectomy. However, complete resection of the lesion is still mandatory. Parotid gland clinical Benign neoplasms Up to 80% of all salivary gland tumours occur in the parotid gland and up to 80% of these are benign. There is no consistent correlation between the rate of growth and the malignant potential of the lesion. However, benign tumours should not invade structures such as the facial nerve. With the exception of Warthins tumours, they are commoner in women than men. The median age of developing a lesion is in the 5th decade of life. Benign tumour types Tumour type Features Benign pleomorphic adenoma or benign mixed tumor Most common parotid neoplasm (80%) Proliferation of epithelial and myoepithelial cells of the ducts and an increase in stromal components Slow growing, lobular, and not well encapsulated Recurrence rate of 1-5% with appropriate excision (parotidectomy) Recurrence possibly secondary to capsular disruption during surgery Malignant degeneration occurring in 2-10% of adenomas observed for long periods, with carcinoma ex-pleomorphic adenoma occurring most frequently as adenocarcinoma Warthin tumor (papillary cystadenoma lymphoma or adenolymphoma) Second most common benign parotid tumor (5%) Most common bilateral benign neoplasm of the parotid Marked male as compared to female predominance Occurs later in life (sixth and seventh decades) Presents as a lymphocytic infiltrate and cystic epithelial proliferation May represent heterotopic salivary gland epithelial tissue trapped within intraparotid lymph nodes Incidence of bilaterality and multicentricity of 10% Malignant transformation rare (almost unheard of) Monomorphic adenoma Account for less than 5% of tumours Slow growing Consist of only one morphological cell type (hence term mono) Include; basal cell adenoma, canalicular adenoma, oncocytoma, myoepitheliomas Haemangioma Should be considered in the differential of a parotid mass in a child Accounts for 90% of parotid tumours in children less than 1 year of age Hypervascular on imaging Spontaneous regression may occur and malignant transformation is almost unheard of Malignant salivary gland tumours Types of malignancy Mucoepidermoid carcinoma 30% of all parotid malignancies Usually low potential for local invasiveness and metastasis (depends mainly on grade) Adenoid cystic carcinoma Unpredictable growth pattern Tendency for perineural spread Nerve growth may display skip lesions resulting in incomplete excision Distant metastasis more common (visceral rather than nodal spread) 5 year survival 35% Mixed tumours Often a malignancy occurring in a previously benign parotid lesion Acinic cell carcinoma Intermediate grade malignancy May show perineural invasion Low potential for distant metastasis 5 year survival 80% Adenocarcinoma Develops from secretory portion of gland Risk of regional nodal and distant metastasis 5 year survival depends upon stage at presentation, may be up to 75% with small lesions with no nodal involvement Lymphoma Large rubbery lesion, may occur in association with Warthins tumours Diagnosis should be based on regional nodal biopsy rather than parotid resection Treatment is with chemotherapy (and radiotherapy) Diagnostic evaluation Plain x-rays may be used to exclude calculi Sialography may be used to delineate ductal anatomy FNAC is used in most cases Superficial parotidectomy may be either diagnostic or therapeutic depending upon the nature of the lesion Where malignancy is suspected the primary approach should be definitive resection rather than excisional biopsy CT/ MRI may be used in cases of malignancy for staging primary disease Treatment For nearly all lesions this consists of surgical resection, for benign disease this will usually consist of a superficial parotidectomy. For malignant disease a radical or extended radical parotidectomy is performed. The facial nerve is included in the resection if involved. The need for neck dissection is determined by the potential for nodal involvement. Other parotid disorders HIV infection Lymphoepithelial cysts associated with HIV occur almost exclusively in the parotid Typically presents as bilateral, multicystic, symmetrical swelling Risk of malignant transformation is low and management usually conservative Sjogren syndrome Autoimmune disorder characterised by parotid enlargement, xerostomia and keratoconjunctivitis sicca 90% of cases occur in females Second most common connective tissue disorder Bilateral, non tender enlargement of the gland is usual Histologically, the usual findings are of a lymphocytic infiltrate in acinar units and epimyoepithelial islands surrounded by lymphoid stroma Treatment is supportive There is an increased risk of subsequent lymphoma Sarcoid Parotid involvement occurs in 6% of patients with sarcoid Bilateral in most cases Gland is not tender Xerostomia may occur Management of isolated parotid disease is usually conservative

Answer 1779

The spinous process is formed by 2 laminae posteriorly. Vertebral column There are 7 cervical, 12 thoracic, 5 lumbar, and 5 sacral vertebrae. The spinal cord segmental levels do not necessarily correspond to the vertebral segments. For example, while the C1 cord is located at the C1 vertebra, the C8 cord is situated at the C7 vertebra. While the T1 cord is situated at the T1 vertebra, the T12 cord is situated at the T8 vertebra. The lumbar cord is situated between T9 and T11 vertebrae. The sacral cord is situated between the T12 to L2 vertebrae. Cervical vertebrae The interface between the first and second vertebra is called the atlanto-axis junction. The C3 cord contains the phrenic nucleus. Muscle Nerve root value Deltoid C5,6 Biceps C5,6 Wrist extensors C6-8 Triceps C6-8 Wrist flexors C6-T1 Hand muscles C8-T1 Thoracic vertebrae The thoracic vertebral segments are defined by those that have a rib. The spinal roots form the intercostal nerves that run on the bottom side of the ribs and these nerves control the intercostal muscles and associated dermatomes. Lumbosacral vertebrae Form the remainder of the segments below the vertebrae of the thorax. The lumbosacral spinal cord, however, starts at about T9 and continues only to L2. It contains most of the segments that innervate the hip and legs, as well as the buttocks and anal regions. Cauda Equina The spinal cord ends at L1-L2 vertebral level. The tip of the spinal cord is called the conus. Below the conus, there is a spray of spinal roots that is called the cauda equina. Injuries below L2 represent injuries to spinal roots rather than the spinal cord proper.

Answer 1780

The right lobe of the liver is the most likely site of injury. Therefore the answer is B as the quadrate lobe is functionally part of the left lobe of the liver. The liver is largely covered in peritoneum. Posteriorly there is an area devoid of peritoneum (the bare area of the liver). The right lobe of the liver has the largest bare area (and is larger than the left lobe). Liver Structure of the liver Right lobe Supplied by right hepatic artery Contains Couinaud segments V to VIII (-/+Sg I) Left lobe Supplied by the left hepatic artery Contains Couinaud segments II to IV (+/- Sg1) Quadrate lobe Part of the right lobe anatomically, functionally is part of the left Couinaud segment IV Porta hepatis lies behind On the right lies the gallbladder fossa On the left lies the fossa for the umbilical vein Caudate lobe Supplied by both right and left hepatic arteries Couinaud segment I Lies superior to the porta hepatis Anterior and medial to the inferior vena cava Bile from the caudate lobe drains into both right and left hepatic ducts Detailed knowledge of Couinaud segments is not required for MRCS Between the liver lobules are portal canals which contain the portal triad: Hepatic Artery, Portal Vein, tributary of Bile Duct. Relations of the liver Anterior Postero inferiorly Diaphragm Oesophagus Xiphoid process Stomach Duodenum Hepatic flexure of colon Right kidney Gallbladder Inferior vena cava Porta hepatis Location Postero inferior surface, it joins nearly at right angles with the left sagittal fossa, and separates the caudate lobe behind from the quadrate lobe in front Transmits Common hepatic duct Hepatic artery Portal vein Sympathetic and parasympathetic nerve fibres Lymphatic drainage of the liver (and nodes) Ligaments Falciform ligament 2 layer fold peritoneum from the umbilicus to anterior liver surface Contains ligamentum teres (remnant umbilical vein) On superior liver surface it splits into the coronary and left triangular ligaments Ligamentum teres Joins the left branch of the portal vein in the porta hepatis Ligamentum venosum Remnant of ductus venosus Arterial supply Hepatic artery Venous Hepatic veins Portal vein Nervous supply Sympathetic and parasympathetic trunks of coeliac plexus

Answer 1781

The obturator nerve is most closely related to the bladder Obturator nerve The obturator nerve arises from L2, L3 and L4 by branches from the ventral divisions of each of these nerve roots. L3 forms the main contribution and the second lumbar branch is occasionally absent. These branches unite in the substance of psoas major, descending vertically in its posterior part to emerge from its medial border at the lateral margin of the sacrum. It then crosses the sacroiliac joint to enter the lesser pelvis, it descends on obturator internus to enter the obturator groove. In the lesser pelvis the nerve lies lateral to the internal iliac vessels and ureter, and is joined by the obturator vessels lateral to the ovary or ductus deferens. Supplies Medial compartment of thigh Muscles supplied: external obturator, adductor longus, adductor brevis, adductor magnus (not the lower part-sciatic nerve), gracilis The cutaneous branch is often absent. When present, it passes between gracilis and adductor longus near the middle part of the thigh, and supplies the skin and fascia of the distal two thirds of the medial aspect. Obturator canal Connects the pelvis and thigh: contains the obturator artery, vein, nerve which divides into anterior and posterior branches.

Answer 1782

This question is asking what structure forms the anterior wall of the inguinal canal. The anterior wall is formed by the external oblique aponeurosis. Once this is divided the canal is entered, the cord can be mobilised and a hernia repair performed. The transversalis fascia and conjoint tendons form the posterior wall and would not routinely be divided to gain access to the inguinal canal itself. External oblique muscle External oblique forms the outermost muscle of the three muscles comprising the anterolateral aspect of the abdominal wall. Its aponeurosis comprises the anterior wall of the inguinal canal. Origin Outer surfaces of the lowest eight ribs Insertion Anterior two thirds of the outer lip of the iliac crest. The remainder becomes the aponeurosis that fuses with the linea alba in the midline. Nerve supply Ventral rami of the lower six thoracic nerves Actions Contains the abdominal viscera, may contract to raise intra abdominal pressure. Moves trunk to one side.

Answer 1783

Cystic medial necrosis ( or cystic medial degeneration) occurs when basophils and mucoid material lie in between the intimal elastic fibres of the aorta. It is typically found in the aortic degeneration of Marfans syndrome, but may also be seen in aortic degeneration in older adults. Aortic dissection More common than rupture of the abdominal aorta 33% of patients die within the first 24 hours, and 50% die within 48 hours if no treatment received Associated with hypertension Features of aortic dissection: tear in the intimal layer, followed by formation and propagation of a subintimal hematoma. Cystic medial necrosis (Marfan's) Most common site of dissection: 90% occurring within 10 centimetres of the aortic valve Stanford Classification Type Location Treatment A Ascending aorta/ aortic root Surgery- aortic root replacement B Descending aorta Medical therapy with antihypertensives DeBakey classification Type Site affected I Ascending aorta, aortic arch, descending aorta II Ascending aorta only III Descending aorta distal to left subclavian artery Clinical features Tearing, sudden onset chest pain (painless 10%) Hypertension or Hypotension A blood pressure difference (in each arm) greater than 20 mm Hg Neurologic deficits (20%) Investigations CXR: widened mediastinum, abnormal aortic knob, ring sign, deviation of the trachea/oesophagus CT angiography of the thoracic aorta MRI angiography Conventional angiography (now rarely used diagnostically) Management Beta-blockers: aim HR 60-80 bpm and systolic BP 100-120 mm Hg For type A dissections the standard of care is aortic root replacement

Answer 1784

Fibrinoid necrosis is seen in the arterioles of patients with malignant hypertension. Cell death Cells can die via two mechanisms; necrosis and apoptosis. These are outlined below: Necrosis Necrosis is characterised by bioenergetics failure. Loss of tissue perfusion results in hypoxia and an inability to generate ATP. The integrity of the cellular membrane is lost and the loss of ATP results in loss of energy dependent cellular transport mechanisms. There is an influx of water, ionic instability and cellular lysis. The release of intracellular contents may stimulate an inflammatory response. Several types of necrosis are recognised; coagulative, colliquative, caseous, gangrene, fibrinoid and fat necrosis. The type of tissue and the underlying cause determine the predominant necrosis pattern. Coagulative necrosis The commonest type, occurs in most organs Tissue is initially firm, later becomes soft as tissue is digested by macrophages In the early phases the histological appearances may demonstrate little change In later stages cellular outlines are seen with loss of intracellular detail Colliquative necrosis Occurs in tissues with no supporting stroma Dominant necrosis pattern in the CNS Necrotic site may eventually become encysted Caseous necrosis No definable structure seen in the necrotic tissue Amorphous eosinophilic tissue may be seen histologically Classically seen in tuberculosis Gangrene Necrosis with putrefaction of tissue May complicate ischaemia Haemoglobin degenerates and results in the deposition of iron sulphide (which is why the tissue is black) Both wet and dry gangrene may occur, in wet gangrene there is often a liquefactive component and super-added infection (which usually smells!) Fibrinoid necrosis Classically seen in arterioles in patients with hypertension (malignant type) Necrosis of the smooth muscle wall occurs and plasma may extravasate into the media with fibrin deposition Fat necrosis Direct trauma to fat can result in rupture of adipocytes Lipids incite a local inflammatory reaction Inflammatory cells phagocytose the lipid with eventual fibrosis Apoptosis Also known as programmed cell death Energy dependent pathways are activated via a number of intracellular signalling mechanisms It is the result of the activation of caspases triggered by the bcl-2 family or the binding of the FAS ligand to its receptor DNA fragments, mitochondrial function ceases, nuclear and cellular shrinkage occurs Phagocytosis of the cell does not occur, instead the cell degenerates into apoptotic bodies

Answer 1785

Creatinine declines with age due to decline in renal function and muscle mass. Glucose, protein (amino acids) and PAH are reabsorbed by the kidney. Renal Physiology Overview Each nephron is supplied with blood from an afferent arteriole that opens onto the glomerular capillary bed. Blood then flows to an efferent arteriole, supplying the peritubular capillaries and medullary vasa recta. The kidney receives up to 25% of resting cardiac output. Control of blood flow The kidney is able to autoregulate its blood flow between systolic pressures of 80- 180mmHg so there is little variation in renal blood flow. This is achieved by myogenic control of arteriolar tone, both sympathetic input and hormonal signals (e.g. renin) are responsible. Glomerular structure and function Blood inside the glomerulus has considerable hydrostatic pressure. The basement membrane has pores that will allow free diffusion of smaller solutes, larger negatively charged molecules such as albumin are unable to cross. The glomerular filtration rate (GFR) is equal to the concentration of a solute in the urine, times the volume of urine produced per minute, divided by the plasma concentration (assuming that the solute is freely diffused e.g. inulin). In clinical practice creatinine is used because it is subjected to very little proximal tubular secretion. Although subject to variability, the typical GFR is 125ml per minute. Glomerular filtration rate = Total volume of plasma per unit time leaving the capillaries and entering the bowman's capsule Renal clearance = volume plasma from which a substance is removed per minute by the kidneys Substances used to measure GFR have the following features: 1. Inert 2. Free filtration from the plasma at the glomerulus (not protein bound) 3. Not absorbed or secreted at the tubules 4. Plasma concentration constant during urine collection Examples: inulin, creatinine GFR = urine concentration (mmol/l) x urine volume (ml/min) -------------------------------------------------------------------------- plasma concentration (mmol/l) The clearance of a substance is dependent not only on its diffusivity across the basement membrane but also subsequent tubular secretion and / or reabsorption. So glucose which is freely filtered across the basement membrane is usually reabsorbed from tubules giving a clearance of zero. Tubular function Reabsorption and secretion of substances occurs in the tubules. In the proximal tubule substrates such as glucose, amino acids and phosphate are co-transported with sodium across the semi permeable membrane. Glucose is reabsorbed by both active and passive processes. The former uses sodiumâ€“glucose co-transporters (SGLTs) in the proximal convoluted tubule. The latter achieved through facilitated and passive process through GLUT transporters. Up to two thirds of filtered water is reabsorbed in the proximal tubules. This will lead to increase in urea concentration in the distal tubule allowing for its increased diffusion. Substances to be secreted into the tubules are taken up from the peritubular blood by tubular cells. Solutes such as paraaminohippuric acid are cleared with a single passage through the kidneys and this is why it is used to measure renal plasma flow. Ions such as calcium and phosphate will have a tubular reabsorption that is influenced by plasma PTH levels. Potassium may be both secreted and re-absorbed and is co-exchanged with sodium. Loop of Henle Approximately 60 litres of water containing 9000mmol sodium enters the descending limb of the loop of Henle in 24 hours. Loops from the juxtamedullary nephrons run deep into the medulla. The osmolarity of fluid changes and is greatest at the tip of the papilla. The thick ascending limb is impermeable to water, but highly permeable to sodium and chloride ions. This loss means that at the beginning of the thick ascending limb the fluid is hypo osmotic compared with adjacent interstitial fluid. In the thick ascending limb the reabsorption of sodium and chloride ions occurs by both facilitated and passive diffusion pathways. The loops of Henle are co-located with vasa recta, these will have similar solute compositions to the surrounding extracellular fluid so preventing the diffusion and subsequent removal of this hypertonic fluid. The energy dependent reabsorption of sodium and chloride in the thick ascending limb helps to maintain this osmotic gradient.

Answer 1786

Flow volume loop is the best investigation to assess for possible compression of the upper airways. It is a graphical representation of the rate and volume of air flow during inhalation and exhalation, which can reveal any obstruction or narrowing of the airways. In the case of upper airway compression, the flow volume loop will show a flattened expiratory curve and decreased peak expiratory flow rate. Arterial blood gases, forced vital capacity, and transfer factor are not useful in assessing upper airway compression. Flow volume loop A normal flow volume loop is often described as a 'triangle on top of a semi circle' Flow volume loops are the most suitable way of assessing compression of the upper airway

Answer 1787

Salmonella The Salmonella group contains many members, most of which cause diarrhoeal diseases. They are facultative anaerobes, Gram negative rods which are not normally present as commensals in the gut. Typhoid and paratyphoid are caused by Salmonella typhi and Salmonella paratyphi (types A, B & C) respectively. They are often termed enteric fevers, producing systemic symptoms such as headache, fever, arthralgia Features initially systemic upset as above relative bradycardia abdominal pain, distension constipation: although Salmonella is a recognised cause of diarrhoea, constipation is more common in typhoid rose spots: present on the trunk in 40% of patients, and are more common in paratyphoid Possible complications include osteomyelitis (especially in sickle cell disease where Salmonella is one of the most common pathogens) GI bleed/perforation meningitis cholecystitis chronic carriage (1%, more likely if adult females)

Answer 1788

The interossei are supplied by the ulnar nerve. Ulnar nerve Origin C8, T1 Supplies (no muscles in the upper arm) Flexor carpi ulnaris Flexor digitorum profundus Flexor digiti minimi Abductor digiti minimi Opponens digiti minimi Adductor pollicis Interossei muscle Third and fourth lumbricals Palmaris brevis Path Posteromedial aspect of upper arm to flexor compartment of forearm, then along the ulnar. Passes beneath the flexor carpi ulnaris muscle, then superficially over the flexor retinaculum into the palm of the hand. Branches Branch Supplies Muscular branch Flexor carpi ulnaris Medial half of the flexor digitorum profundus Palmar cutaneous branch (Arises near the middle of the forearm) Skin on the medial part of the palm Dorsal cutaneous branch Dorsal surface of the medial part of the hand Superficial branch Cutaneous fibres to the anterior surfaces of the medial one and one-half digits Deep branch Hypothenar muscles All the interosseous muscles Third and fourth lumbricals Adductor pollicis Medial head of the flexor pollicis brevis Effects of injury Damage at the wrist Wasting and paralysis of intrinsic hand muscles (claw hand) Wasting and paralysis of hypothenar muscles Loss of sensation medial 1 and half fingers Damage at the elbow Radial deviation of the wrist Clawing less in 4th and 5th digits

Answer 1789

The posterior aspect is intrasynovial and the knee itself comprises the largest synovial joint in the body. It may swell considerably following trauma such as ACL injury. Which may be extremely painful owing to rich innervation from femoral, sciatic and ( a smaller) contribution from the obturator nerve. During full extension all ligaments are taut and the knee is locked. Knee joint The knee joint is a synovial joint, the largest and most complicated. It consists of two condylar joints between the femur and tibia and a sellar joint between the patella and the femur. The tibiofemoral articular surfaces are incongruent, however, this is improved by the presence of the menisci. The degree of congruence is related to the anatomical position of the knee joint and is greatest in full extension. Knee joint compartments Tibiofemoral Comprised of the patella/femur joint, lateral and medial compartments (between femur condyles and tibia) Synovial membrane and cruciate ligaments partially separate the medial and lateral compartments Patellofemoral Ligamentum patellae Actions: provides joint stability in full extension Fibrous capsule The capsule of the knee joint is a complex, composite structure with contributions from adjacent tendons. Anterior fibres The capsule does not pass proximal to the patella. It blends with the tendinous expansions of vastus medialis and lateralis Posterior fibres These fibres are vertical and run from the posterior surface of the femoral condyles to the posterior aspect of the tibial condyle Medial fibres Attach to the femoral and tibial condyles beyond their articular margins, blending with the tibial collateral ligament Lateral fibres Attach to the femur superior to popliteus, pass over its tendon to head of fibula and tibial condyle Bursae Anterior Subcutaneous prepatellar bursa; between patella and skin Deep infrapatellar bursa; between tibia and patellar ligament Subcutaneous infrapatellar bursa; between distal tibial tuberosity and skin Laterally Bursa between lateral head of gastrocnemius and joint capsule Bursa between fibular collateral ligament and tendon of biceps femoris Bursa between fibular collateral ligament and tendon of popliteus Medially Bursa between medial head of gastrocnemius and the fibrous capsule Bursa between tibial collateral ligament and tendons of sartorius, gracilis and semitendinosus Bursa between the tendon of semimembranosus and medial tibial condyle and medial head of gastrocnemius Posterior Highly variable and inconsistent Ligaments Medial collateral ligament Medial epicondyle femur to medial tibial condyle: valgus stability Lateral collateral ligament Lateral epicondyle femur to fibula head: varus stability Anterior cruciate ligament Anterior tibia to lateral intercondylar notch femur: prevents tibia sliding anteriorly Posterior cruciate ligament Posterior tibia to medial intercondylar notch femur: prevents tibia sliding posteriorly Patellar ligament Central band of the tendon of quadriceps femoris, extends from patella to tibial tuberosity Menisci Medial and lateral menisci compensate for the incongruence of the femoral and tibial condyles. Composed of fibrous tissue. Medial meniscus is attached to the tibial collateral ligament. Lateral meniscus is attached to the loose fibres at the lateral edge of the joint and is separate from the fibular collateral ligament. The lateral meniscus is crossed by the popliteus tendon. Nerve supply The knee joint is supplied by the femoral, tibial and common peroneal divisions of the sciatic and by a branch from the obturator nerve. Hip pathology pain may be referred to the knee. Blood supply Genicular branches of the femoral artery, popliteal and anterior tibial arteries all supply the knee joint.

Answer 1790

The sigmoid sinus is joined by the inferior petrosal sinus to drain into the internal jugular vein. Cranial venous sinuses The cranial venous sinuses are located within the dura mater. They have no valves which is important in the potential for spreading sepsis. They eventually drain into the internal jugular vein. They are: Superior sagittal sinus Inferior sagittal sinus Straight sinus Transverse sinus Sigmoid sinus Confluence of sinuses Occipital sinus Cavernous sinus

Answer 1791

Full thickness burns involve complete injury to the dermis and sub dermal appendages. They have a leathery, often white appearance. They are initially insensate although pain often occurs during healing following skin grafting. They do not blanch under pressure. Burns Burns may be thermal, chemical or electrical. In the former category are burns which occur as a result of heat. Chemical burns occur when the skin is exposed to an extremely caustic or alkaline substance. Electrical burns occur following exposure to electrical current. The immediate management includes removal of the burning source which usually includes irrigation of the burned area. A detailed assessment then needs to be made of the extent of the burns and a number of charts are available for recording this information. The degree of injury relates to the temperature and duration of exposure. Most domestic burns are mainly scalds in young children. Following the burn, there is a local response with progressive tissue loss and release of inflammatory cytokines. Systemically, there are cardiovascular effects resulting from fluid loss and sequestration of fluid into the third space. There is a marked catabolic response. Immunosuppression is common with large burns and bacterial translocation from the gut lumen is a recognised event. Sepsis is a common cause of death following major burns. Types of burn Type of burn Skin layers affected Skin appearance Blanching Management Epidermal/Superficial Epidermis Red, moist Yes Superficial partial thickness Epidermis and part of papillary dermis affected Pale, dry Yes Normally heals with no intervention Deep partial thickness Epidermis, whole papillary dermis affected Mottled red colour No Needs surgical intervention (depending on site) Full thickness Whole skin layer and subcutaneous tissue affected Dry, leathery hard wound No Burns centre Depth of burn assessment Bleeding on needle prick Sensation Appearance Blanching to pressure Percentage burn estimation Lund Browder chart: most accurate even in children Wallace rule of nines Palmar surface: surface area palm = 0.8% burn >15% body surface area burns in adults needs urgent burn fluid resuscitation Transfer to burn centre if: Need burn shock resuscitation Face/hands/genitals affected Deep partial thickness or full thickness burns Significant electrical/chemical burns Management The initial aim is to stop the burning process and resuscitate the patient. Intravenous fluids will be required for children with burns greater than 10% of total body surface area. Adults with burns greater than 15% of total body surface area will also require IV fluids. The fluids are calculated using the Parkland formula which is; volume of fluid= total body surface area of the burn % x weight (Kg) x2-4 (preference for lower amount i.e. 2ml to avoid excessive fluid overload). Half of the fluid is administered in the first 8 hours. A urinary catheter should be inserted. Analgesia should be given. Complex burns, burns involving the hand perineum and face and burns >10% in adults and >5% in children should be transferred to a burns unit. Circumferential burns affecting a limb or severe torso burns impeding respiration may require escharotomy to divide the burnt tissue. Conservative management is appropriate for superficial burns and mixed superficial burns that will heal in 2 weeks. More complex burns may require excision and skin grafting. Excision and primary closure is not generally practised as there is a high risk of infection. There is no evidence to support the use of anti microbial prophylaxis or topical antibiotics in burn patients. Escharotomies Indicated in circumferential full thickness burns to the torso or limbs. Careful division of the encasing band of burn tissue will potentially improve ventilation (if the burn involves the torso), or relieve compartment syndrome and oedema (where a limb is involved) References www.euroburn.org/e107files/downloads/guidelinesburncare.pdf Barajas-Nava LA, LÃ³pez-Alcalde J, RoquÃ© i Figuls M, SolÃ I, Bonfill Cosp X. Antibiotic prophylaxis for preventing burn wound infection. Cochrane Database of Systematic Reviews 2013, Issue 6. Art. No.: CD008738. DOI: 10.1002/14651858.CD008738.pub2. Hettiaratchy S & Papini R. Initial management of a major burn: assessment and resuscitation. BMJ 2004;329:101-103

Answer 1792

Psoas major inserts onto the lesser trochanter. Femur - Extends from a rounded head, which articulates with the acetabulum down to the knee joint where the two large condyles at it's inferior aspect articulate with the tibia. The superior aspect comprises a head and neck which pass inferolaterally to the body and the two trochanters. These lie at the junction between the neck and the body. The neck meets the body of the femur at an angle of 125o. Developmentally, the neck is part of the body but is demarcated from it by a wide rough intertrochanteric crest, this continues inferomedially as a spiral line that runs below the lesser trochanter. Medially, the intertrochanteric line gives attachment to the inferior end of the iliofemoral ligament. The neck is covered by synovial membrane up to the intertrochanteric line. The posterior aspect of the neck is demarcated from the shaft by the intertrochanteric crest and only it's medial aspect is covered by synovium and the joint capsule. The greater trochanter has discernible surfaces that form the site of attachment of the gluteal muscles.Laterally, the greater trochanter overhangs the body and this forms part of the origin of vastus lateralis Viewed anteriorly, the body of the femur appears rounded. Viewed laterally, it has an anterior concavity which gives fullness to the anterior thigh. Posteriorly, there is a ridge of bone, the linea aspera. The surface of the anterior aspect of the body forms the origin of the vastus intermedius. More medially, it forms the origin of vastus medialis. The upper and middle aspects of the linea aspera form part of the origin of the attachments of the thigh adductors. Inferiorly, it spans out to form the bony floor of the popliteal fossa. At the inferior aspect of the popliteal surface the surface curves posteriorly to form the femoral condyles. The structures that are attached to the inferior aspect of the linea aspera split with it as it approaches the popliteal fossa. Thus the vastus medialis and adductor magnus continue with the medial split and the biceps femoris and vastus intermedius along the lateral split. Blood supply The femur has a rich blood supply and numerous vascular foramina exist throughout it's length. The blood supply to the femoral head is clinically important and is provided by the medial circumflex femoral and lateral circumflex femoral arteries (Branches of profunda femoris). Also from the inferior gluteal artery. These form an anastomosis and travel to up the femoral neck to supply the head.

Answer 1793

The Axillary nerve winds around the bone at the neck of the humerus. The axillary nerve is also at risk during shoulder dislocation. Axillary nerve Terminal branch of the posterior cord of the brachial plexus Root values C5 and C6 Descends posterior to the axillary artery at the lower border of subscapularis and then passes through quadrangular space with the posterior circumflex humeral vessels Divides into anterior and posterior branches Innervates deltoid muscle and small patch of skin over deltoid

Answer 1794

The use of previous radiotherapy means that the wound will not heal well. A myocutaneous flap will mean that non irradiated tissue is interposed into the wound bed. Rotational skin flaps will comprise irradiated tissue and won't heal. Methods of wound closure Method of closure Indication Primary closure Clean wound, usually surgically created or following minor trauma Standard suturing methods will usually suffice Wound heals by primary intention Delayed primary closure Similar methods of actual closure to primary closure May be used in situations where primary closure is either not achievable or not advisable e.g. infection Vacuum assisted closure Uses negative pressure therapy to facilitate wound closure Sponge is inserted into wound cavity and then negative pressure applied Advantages include removal of exudate and versatility Disadvantages include cost and risk of fistulation if used incorrectly on sites such as bowel Split thickness skin grafts Superficial dermis removed with Watson knife or dermatome (commonly from thigh) Remaining epithelium regenerates from dermal appendages Coverage may be increased by meshing Full thickness skin grafts Whole dermal thickness is removed Sub dermal fat is then removed and graft placed over donor site Better cosmesis and flexibility at recipient site Donor site morbidity Flaps Viable tissue with a blood supply May be pedicled or free Pedicled flaps are more reliable, but limited in range Free flaps have greater range but carry greater risk of breakdown as they require vascular anastomosis

Answer 1795

D- CN VII â€“ Buccal branch Pneumoparotid is a very rare condition of parotid gland, often complicating with a subcutaneous emphysema, causing swelling of the parotid lodge. This pathology usually occurred due no physiological stagnation of air in parotid parenchyma. Pneumoparotid is usually associated with a retrograde insufflation of air and saliva via Stensens duct into the secondary ducts and glandular acini. Hypotonia of the buccinator muscle, hypertrophy of the masseter muscle or temporary obstruction of the Stensens duct by mucous are described as possible risk factors. The opening of the Stensens duct lies near to the second upper molar tooth bilaterally. The normal anatomy of duct preventing the reflux of air and saliva into the parotid gland are three fold: The diameter of the duct orifice is smaller than that of the duct itself; The duct opening is covered by redundant mucosal layer, covering the duct orifice when there is increased intraoral pressure. The Stensens duct is compressed in its lateral course along the masseter muscle and its passage through the buccinator muscle with an increase in oral pressure. The buccinator is the muscle of interest here. Motor innervation is from the buccal branch of the facial nerve (cranial nerve VII). Sensory innervation is supplied by the buccal branch (one of the muscular branches) of the mandibular part of the trigeminal (cranial nerve V). Facial nerve The facial nerve is the main nerve supplying the structures of the second embryonic branchial arch. It is predominantly an efferent nerve to the muscles of facial expression, digastric muscle and also to many glandular structures. It contains a few afferent fibres which originate in the cells of its genicular ganglion and are concerned with taste. Supply - 'face, ear, taste, tear' Face: muscles of facial expression Ear: nerve to stapedius Taste: supplies anterior two-thirds of tongue Tear: parasympathetic fibres to lacrimal glands, also salivary glands Path Subarachnoid path Origin: motor- pons, sensory- nervus intermedius Pass through the petrous temporal bone into the internal auditory meatus with the vestibulocochlear nerve. Here they combine to become the facial nerve. Facial canal path The canal passes superior to the vestibule of the inner ear At the medial aspect of the middle ear, it becomes wider and contains the geniculate ganglion. - 3 branches: 1. greater petrosal nerve 2. nerve to stapedius 3. chorda tympani Stylomastoid foramen Passes through the stylomastoid foramen (tympanic cavity anterior and mastoid antrum posteriorly) Posterior auricular nerve and branch to posterior belly of digastric and stylohyoid muscle Face Enters parotid gland and divides into 5 branches: Temporal branch Zygomatic branch Buccal branch Marginal mandibular branch Cervical branch

Answer 1796

Increased mitoses are commonly seen in association with malignant transformation of cells. Apoptosis is not a common feature of metastatic cancer. Barr Bodies are formed during X chromosome inactivation in female somatic cells. Histopathology of malignancy Abnormal tissue architecture Coarse chromatin Invasion of basement membrane* Abnormal mitoses Angiogenesis De-differentiation Areas of necrosis Nuclear pleomorphism *= Those features that distinguish invasive malignancy from in situ disease

Answer 1797

This question is addressing the blood supply to the rectum. Which is supplied by the superior rectal artery. High ligation of the IMA may compromise this structure. However, the question states that during the Hartmans procedure the vessels were ligated close to the bowel. Implying that the superior rectal was preserved. Rectum The rectum is approximately 12 cm long. It is a capacitance organ. It has both intra and extraperitoneal components. The transition between the sigmoid colon is marked by the disappearance of the tenia coli.The extra peritoneal rectum is surrounded by mesorectal fat that also contains lymph nodes. This mesorectal fatty layer is removed surgically during rectal cancer surgery (Total Mesorectal Excision). The fascial layers that surround the rectum are important clinical landmarks, anteriorly lies the fascia of Denonvilliers. Posteriorly lies Waldeyers fascia. Extra peritoneal rectum Posterior upper third Posterior and lateral middle third Whole lower third Relations Anteriorly (Males) Rectovesical pouch Bladder Prostate Seminal vesicles Anteriorly (Females) Recto-uterine pouch (Douglas) Cervix Vaginal wall Posteriorly Sacrum Coccyx Middle sacral artery Laterally Levator ani Coccygeus Arterial supply Superior rectal artery Middle rectal artery (from the internal iliac) Inferior rectal artery (from the pudendal vessels) Venous drainage Superior rectal vein Inferior rectal vein Note the venous drainage is a site of portosystemic anastomosis. Lymphatic drainage Mesorectal lymph nodes (superior to dentate line) Inguinal nodes (inferior to dentate line)

Answer 1798

The inferior mesenteric artery may have been ligated and being an arteriopath collateral flow through the marginal may be imperfect. Lower Gastrointestinal bleeding Colonic bleeding This typically presents as bright red or dark red blood per rectum. Colonic bleeding rarely presents as malaena type stool, this is because blood in the colon has a powerful laxative effect and is rarely retained long enough for transformation to occur and because the digestive enzymes present in the small bowel are not present in the colon. Up to 15% of patients presenting with haemochezia will have an upper gastrointestinal source of haemorrhage. As a general rule right sided bleeds tend to present with darker coloured blood than left sided bleeds. Haemorrhoidal bleeding typically presents as bright red rectal bleeding that occurs post defecation either onto toilet paper or into the toilet pan. It is very unusual for haemorrhoids alone to cause any degree of haemodynamic compromise. Causes Cause Presenting features Colitis Bleeding may be brisk in advanced cases, diarrhoea is commonly present. Abdominal x-ray may show featureless colon. Diverticular disease Acute diverticulitis often is not complicated by major bleeding and diverticular bleeds often occur sporadically. 75% all will cease spontaneously within 24-48 hours. Bleeding is often dark and of large volume. Cancer Colonic cancers often bleed and for many patients this may be the first sign of the disease. Major bleeding from early lesions is uncommon Haemorrhoidal bleeding Typically bright red bleeding occurring post defecation. Although patients may give graphic descriptions bleeding of sufficient volume to cause haemodynamic compromise is rare. Angiodysplasia Apart from bleeding, which may be massive, these arteriovenous lesions cause little in the way of symptoms. The right side of the colon is more commonly affected. Management Prompt correction of any haemodynamic compromise is required. Unlike upper gastrointestinal bleeding the first line management is usually supportive. This is because in the acute setting endoscopy is rarely helpful. When haemorrhoidal bleeding is suspected a proctosigmoidoscopy is reasonable as attempts at full colonoscopy are usually time consuming and often futile. In the unstable patient the usual procedure would be an angiogram (either CT or percutaneous), when these are performed during a period of haemodynamic instability they may show a bleeding point and may be the only way of identifying a patch of angiodysplasia. In others who are more stable the standard procedure would be a colonoscopy in the elective setting. In patients undergoing angiography attempts can be made to address the lesion in question such as coiling. Otherwise surgery will be necessary. In patients with ulcerative colitis who have significant haemorrhage the standard approach would be a sub total colectomy, particularly if medical management has already been tried and is not effective. Indications for surgery Patients > 60 years Continued bleeding despite endoscopic intervention Recurrent bleeding Known cardiovascular disease with poor response to hypotension Surgery Selective mesenteric embolisation if life threatening bleeding. This is most helpful if conducted during a period of relative haemodynamic instability. If all haemodynamic parameters are normal then the bleeding is most likely to have stopped and any angiography normal in appearance. In many units a CT angiogram will replace selective angiography but the same caveats will apply. If the source of colonic bleeding is unclear; perform a laparotomy, on table colonic lavage and following this attempt a resection. A blind sub total colectomy is most unwise, for example bleeding from an small bowel arterio-venous malformation will not be treated by this manoeuvre. Summary of Acute Lower GI bleeding recommendations Consider admission if: * Over 60 years * Haemodynamically unstable/profuse PR bleeding * On aspirin or NSAID * Significant co morbidity Management All patients should have a history and examination, PR and proctoscopy Colonoscopic haemostasis aimed for in post polypectomy or diverticular bleeding References http://www.sign.ac.uk/guidelines/fulltext/105/index.html

Answer 1799

This lady has acute cholecystitis and needs an acute cholecystectomy. This operation should usually be performed within 72 hours of admission. Delay beyond this timeframe will usually result in increased operative complications and most surgeons would administer antibiotics and perform an interval cholecystectomy if the early window for an acute procedure is missed. A bile duct measuring 4mm is usually normal. Biliary disease Diagnosis Typical features Pathogenesis Gallstones Typically history of biliary colic or episodes of chlolecystitis. Obstructive type history and test results. Usually small calibre gallstones which can pass through the cystic duct. In Mirizzi syndrome the stone may compress the bile duct directly- one of the rare times that cholecystitis may present with jaundice Cholangitis Usually obstructive and will have Charcot's triad of symptoms (pain, fever, jaundice) Ascending infection of the bile ducts usually by E. coli and by definition occurring in a pool of stagnant bile. Pancreatic cancer Typically painless jaundice with palpable gallbladder (Courvoisier's Law) Direct occlusion of distal bile duct or pancreatic duct by tumour. Sometimes nodal disease at the portal hepatis may be the culprit in which case the bile duct may be of normal calibre. TPN (total parenteral nutrition) associated jaundice Usually follows long term use and is usually painless with non obstructive features Often due to hepatic dysfunction and fatty liver which may occur with long term TPN usage. Bile duct injury Depending upon the type of injury may be of sudden or gradual onset and is usually of obstructive type Often due to a difficult laparoscopicÂ cholecystectomy when anatomy in Calots triangle is not appreciated. In the worst scenario the bile duct is excised and jaundice develops rapidly post operatively. More insidious is that of bile duct stenosis which may be caused by clips or diathermy injury. Cholangiocarcinoma Gradual onset obstructive pattern Direct occlusion by disease and also extrinsic compression by nodal disease at the porta hepatis. Septic surgical patient Usually hepatic features Combination of impaired biliary excretion and drugs such as ciprofloxacin which may cause cholestasis. Metastatic disease Mixed hepatic and post hepatic Combination of liver synthetic failure (late) and extrinsic compression by nodal disease and anatomical compression of intra hepatic structures (earlier) A gallbladder may develop a thickened wall in chronic cholecystitis, microscopically Roikitansky-Aschoff Sinuses may be seen

Answer 1800

Lymphocytic infiltrates and fibrosis are typically seen in Hashimotos thyroiditis. In lymphoma only dense lymphatic type tissue is usually present. Thyroid neoplasms Lesion Common features Follicular adenoma Usually present as a solitary thyroid nodule Malignancy can only be excluded on formal histological assessment Papillary carcinoma Usually contain a mixture of papillary and colloidal filled follicles Histologically tumour has papillary projections and pale empty nuclei Seldom encapsulated Lymph node metastasis predominate Haematogenous metastasis rare Account for 60% of thyroid cancers Follicular carcinoma May appear macroscopically encapsulated, microscopically capsular invasion is seen. Without this finding the lesion is a follicular adenoma. Vascular invasion predominates Multifocal disease rare Account for 20% of all thyroid cancers Anaplastic carcinoma Most common in elderly females Local invasion is a common feature Account for 10% of thyroid cancers Treatment is by resection where possible, palliation may be achieved through isthmusectomy and radiotherapy. Chemotherapy is ineffective. Medullary carcinoma Tumours of the parafollicular cells (C Cells) C cells derived from neural crest and not thyroid tissue Serum calcitonin levels often raised Familial genetic disease accounts for up to 20% cases Both lymphatic and haematogenous metastasis are recognised, nodal disease is associated with a very poor prognosis.

Answer 1801

Antegrade ureteric stents pass from the kidney to the bladder Retrograde stents pass from the bladder to the kidney A TCC occluding the ureteric orifice will obscure its identification during surgery, so that passage of a retrograde stent is difficult. Therefore passage of a stent from the renal pelvis is preferable. Hydronephrosis Causes of hydronephrosis Unilateral: PACT Pelvic-ureteric obstruction (congenital or acquired) Aberrant renal vessels Calculi Tumours of renal pelvis Bilateral: SUPER Stenosis of the urethra Urethral valve Prostatic enlargement Extensive bladder tumour Retro-peritoneal fibrosis Investigation USS- identifies presence of hydronephrosis and can assess the kidneys IVU- assess the position of the obstruction Antegrade or retrograde pyelography- allows treatment If renal colic suspected: non contrast CT scan (majority of stones are detected this way) Management Remove the obstruction and drainage of urine Acute upper urinary tract obstruction: Nephrostomy tube Chronic upper urinary tract obstruction: Ureteric stent or a pyeloplasty

Answer 1802

Cardiogenic Shock: e.g. MI, valve abnormality increased SVR (vasoconstriction in response to low BP) increased HR (sympathetic response) decreased cardiac output decreased blood pressure Hypovolaemic shock: blood volume depletion e.g. haemorrhage, vomiting, diarrhoea, dehydration, third-space losses during major operations increased SVR increased HR decreased cardiac output decreased blood pressure Septic shock: occurs when the peripheral vascular dilatation causes a fall in SVR similar response may occur in anaphylactic shock, neurogenic shock reduced SVR increased HR normal/increased cardiac output decreased blood pressure SVR will typically increase in haemorrhagic shock.

Answer 1803

Papillary carcinoma is the most common subtype and may cause lymph node metastasis (mass separate from the gland itself) that is rare with follicular tumours. Anaplastic carcinoma would cause more local symptoms and would be rare in this age group. Thyroid malignancy Papillary carcinoma Commonest sub-type Accurately diagnosed on fine needle aspiration cytology Histologically, they may demonstrate psammoma bodies (areas of calcification) and so called 'orphan Annie' nuclei They typically metastasise via the lymphatics and thus laterally located apparently ectopic thyroid tissue is usually a metastasis from a well differentiated papillary carcinoma Follicular carcinoma Are less common than papillary lesions Like papillary tumours, they may present as a discrete nodule. Although they appear to be well encapsulated macroscopically there is invasion on microscopic evaluation Lymph node metastases are uncommon and these tumours tend to spread haematogenously. This translates into a higher mortality rate Follicular lesions cannot be accurately diagnosed on fine needle aspiration cytology and thus all follicular FNA's (THY 3f) will require at least a hemi thyroidectomy Anaplastic carcinoma Less common and tend to occur in elderly females Disease is usually advanced at presentation and often only palliative decompression and radiotherapy can be offered. Medullary carcinoma These are tumours of the parafollicular cells ( C Cells) and are of neural crest origin. The serum calcitonin may be elevated which is of use when monitoring for recurrence. They may be familial and occur as part of the MEN -2A disease spectrum. Spread may be either lymphatic or haematogenous and as these tumours are not derived primarily from thyroid cells they are not responsive to radioiodine. Lymphoma These respond well to combined chemoradiotherapy Radical surgery is unnecessary once the disease has been diagnosed on biopsy material. Such biopsy material is not generated by an FNA and thus a core biopsy has to be obtained (with care!).

Answer 1804

The trunks are related to the subclavian artery superiorly. The cords of the plexus surround the axillary artery, they are named according to their positions relative to this structure. Brachial plexus The brachial plexus extends from the neck to the axilla. It is formed by the ventral rami of the fifth to the eighth cervical nerves with the ascending part of the first thoracic nerve. Location of the plexus The ventral rami which form the plexus enter the lower part of the posterior triangle of the neck in series with the ventral rami of the cervical plexus. The second part of the subclavian artery lies immediately anterior to the lower two rami. The upper three rami intermingle and pass inferolaterally towards the axilla and subclavian artery. They are enclosed within an extension of the prevertebral fascia. In the neck the plexus lies deep to platysma, the supraclavicular nerves, inferior belly of omohyoid and the transverse cervical artery. It then passes deep to the clavicle and the suprascapular vessels, to enter the axilla, and thence surround the second part of the axillary artery Composition of the plexus Ventral rami, the roots of the plexus, lie between scalenus medius and anterior. As they enter the posterior triangle, the upper two (C5,6) and lower two (C8, T1) roots of the plexus unite to form the upper and lower trunks of the plexus respectively. Meanwhile, C7 continues as the middle trunk. The lower trunk may groove the superior surface of the first rib posterior to the subclavian artery, and the root from the first ventral ramus is always in contact with it. Each trunk divides into ventral and dorsal divisions which are destined to supply the anterior (flexor) and posterior (extensor) parts of the upper limb. The cords of the plexus are formed in the axilla. The dorsal divisions unite to form the posterior cord (C5-8). The ventral divisions of the upper and middle trunks unite to form the lateral cord (C5-7), while the ventral divisions of the lower trunk continues as the medial cord (C8-T1). The cords are named according to their relationship to the axillary artery. Each cord terminates by dividing into two main branches at the beginning of the third part of the artery. Sympathetic communications The fifth and sixth cervical ventral rami receive grey rami communicantes from the middle cervical ganglion, while the two or more grey rami communicantes pass from the inferior cervical ganglion to the seventh and eighth cervical ventral rami. The first thoracic ventral ramus receives its grey ramus from the cervicothoracic ganglion. Its for this reason that inferior plexus injury can be complicated by a Horners syndrome. Summary Origin Anterior rami of C5 to T1 Sections of the plexus Roots, trunks, divisions, cords, branches Mnemonic:Real Teenagers Drink Cold Beer Roots Located in the posterior triangle Pass between scalenus anterior and medius Trunks Located posterior to middle third of clavicle Upper and middle trunks related superiorly to the subclavian artery Lower trunk passes over 1st rib posterior to the subclavian artery Divisions Apex of axilla Cords Related to axillary artery

Answer 1805

This patient has phantom limb pain which is a neuropathic pain. First line management is with amitriptylline or pregabalin. However this patient has orthostatic hypotension, which is a side effect of amitriptylline, therefore pregabalin is the treatment of choice. Management of pain World Health Organisation Analgesic Ladder Initially peripherally acting drugs such as paracetamol or non-steroidal anti-inflammatory drugs (NSAIDs) are given. If pain control is not achieved, the second part of the ladder is to introduce weak opioid drugs such as codeine or dextropropoxyphene together with appropriate agents to control and minimise side effects. The final rung of the ladder is to introduce strong opioid drugs such as morphine. Analgesia from peripherally acting drugs may be additive to that from centrally-acting opioids and thus, the two are given together. The World Federation of Societies of Anaesthesiologists (WFSA) Analgesic Ladder For management of acute pain Initially, the pain can be expected to be severe and may need controlling with strong analgesics in combination with local anaesthetic blocks and peripherally acting drugs. The second rung on the postoperative pain ladder is the restoration of the use of the oral route to deliver analgesia. Strong opioids may no longer be required and adequate analgesia can be obtained by using combinations of peripherally acting agents and weak opioids. The final step is when the pain can be controlled by peripherally acting agents alone. Local anaesthetics Infiltration of a wound with a long-acting local anaesthetic such as Bupivacaine Analgesia for several hours Further pain relief can be obtained with repeat injections or by infusions via a thin catheter Blockade of plexuses or peripheral nerves will provide selective analgesia in those parts of the body supplied by the plexus or nerves Can either be used to provide anaesthesia for the surgery or specifically for postoperative pain relief Especially useful where a sympathetic block is needed to improve postoperative blood supply or where central blockade such as spinal or epidural blockade is contraindicated. Spinal anaesthesia Provides excellent analgesia for surgery in the lower half of the body and pain relief can last many hours after completion of the operation if long-acting drugs containing vasoconstrictors are used. - Side effects of spinal anaesthesia include: hypotension, sensory and motor block, nausea and urinary retention. Epidural anaesthesia An indwelling epidural catheter inserted. This can then be used to provide a continuous infusion of analgesic agents. It can provide excellent analgesia. They are still the preferred option following major open abdominal procedures and help prevent post operative respiratory compromise resulting from pain. - Disadvantages of epidurals is that they usually confine patients to bed, especially if a motor block is present. In addition an indwelling urinary catheter is required. Which may not only impair mobility but also serve as a conduit for infection. They are contraindicated in coagulopathies. Transversus Abdominal Plane block (TAP) In this technique an ultrasound is used to identify the correct muscle plane and local anaesthetic (usually bupivicaine) is injected. The agent diffuses in the plane and blocks many of the spinal nerves. It is an attractive technique as it provides a wide field of blockade but does not require the placement of any indwelling devices. There is no post operative motor impairment. For this reason it is the preferred technique when extensive laparoscopic abdominal procedures are performed. They will then provide analgesia immediately following surgery but as they do not confine the patient to bed, the focus on enhanced recovery can begin sooner. -The main disadvantage is that their duration of action is limited to the half life of the local anaesthetic agent chosen. In addition some anaesthetists do not have the USS skills required to site the injections. Patient Controlled Analgesia (PCA) - Patients administer their own intravenous analgesia and titrate the dose to their own end-point of pain relief using a small microprocessor - controlled pump. Morphine is the most popular drug used. Strong Opioids Severe pain arising from deep or visceral structures requires the use of strong opioids Morphine Short half life and poor bioavailability. Metabolised in the liver and clearance is reduced in patients with liver disease, in the elderly and the debilitated Side effects include nausea, vomiting, constipation and respiratory depression. Tolerance may occur with repeated dosage Pethidine Synthetic opioid which is structurally different from morphine but which has similar actions. Has 10% potency of morphine. Short half life and similar bioavailability and clearance to morphine. Short duration of action and may need to be given hourly. Pethidine has a toxic metabolite (norpethidine) which is cleared by the kidney, but which accumulates in renal failure or following frequent and prolonged doses and may lead to muscle twitching and convulsions. Extreme caution is advised if pethidine is used over a prolonged period or in patients with renal failure. Weak opioids Codeine: markedly less active than morphine, has predictable effects when given orally and is effective against mild to moderate pain. Non opioid analgesics - Mild to moderate pain. Paracetamol Inhibits prostaglandin synthesis. Analgesic and antipyretic properties but little anti-inflammatory effect It is well absorbed orally and is metabolised almost entirely in the liver Side effects in normal dosage and is widely used for the treatment of minor pain. It causes hepatotoxicity in over dosage by overloading the normal metabolic pathways with the formation of a toxic metabolite. NSAIDs Analgesic and anti-inflammatory actions Inhibition of prostaglandin synthesis by the enzyme Cyclooxygenase which catalyses the conversion of arachidonic acid to the various prostaglandins that are the chief mediators of inflammation. All NSAIDs work in the same way and thus there is no point in giving more than one at a time. . NSAIDs are, in general, more useful for superficial pain arising from the skin, buccal mucosa, joint surfaces and bone. Relative contraindications: history of peptic ulceration, gastrointestinal bleeding or bleeding diathesis; operations associated with high blood loss, asthma, moderate to severe renal impairment, dehydration and any history of hypersensitivity to NSAIDs or aspirin. Neuropathic pain National Institute of Clinical Excellence (UK) guidelines: First line: Amitriptyline (Imipramine if cannot tolerate) or pregabalin Second line: Amitriptyline AND pregabalin Third line: refer to pain specialist. Give tramadol in the interim (avoid morphine) If diabetic neuropathic pain: Duloxetine As of 1 April 2019, pregabalin and gabapentin are Class C controlled substances (under the Misuse of Drugs Act 1971) and scheduled under the Misuse of Drugs Regulations 2001 as Schedule 3. Evaluate patients carefully for a history of drug abuse before prescribing and observe patients for development of signs of abuse and dependence (MHRA, Drug Safety Update April 2019). References 1. http://guidance.nice.org.uk/CG173/Guidance/pdf/English 2. Lovich-Sapola J, Smith CE, Brandt CP. Post operative pain control. Surg Clin North Am. 2015 Apr;95(2):301-183. Finnerup N et al. Pharmacotherapy for neuropathic pain in adults: a systematic review and meta-analysis. Lancet Neurol. 2015 Feb;14(2):162-73.

Answer 1806

The ileocolic artery is a branch of the SMA and supplies the right colon and terminal ileum. The transverse colon is supplied by the middle colic artery. As veins accompany arteries in the mesentery and are lined by lymphatics, high ligation is the norm in cancer resections. The ileo-colic artery branches off the SMA near the duodenum. Colon anatomy The colon commences with the caecum. This represents the most dilated segment of the human colon and its base (which is intraperitoneal) is marked by the convergence of teniae coli. At this point is located the vermiform appendix. The colon continues as the ascending colon, the posterior aspect of which is retroperitoneal. The line of demarcation between the intra and retro peritoneal right colon is visible as a white line, in the living, and forms the line of incision for colonic resections. The ascending colon becomes the transverse colon after passing the hepatic flexure. At this location the colon becomes wholly intra peritoneal once again. The superior aspect of the transverse colon is the point of attachment of the transverse colon to the greater omentum. This is an important anatomical site since division of these attachments permits entry into the lesser sac. Separation of the greater omentum from the transverse colon is a routine operative step in both gastric and colonic resections. At the left side of the abdomen the transverse colon passes to the left upper quadrant and makes an oblique inferior turn at the splenic flexure. Following this, the posterior aspect becomes retroperitoneal once again. At the level of approximately L4 the descending colon becomes wholly intraperitoneal and becomes the sigmoid colon. Whilst the sigmoid is wholly intraperitoneal there are usually attachments laterally between the sigmoid and the lateral pelvic sidewall. These small congenital adhesions are not formal anatomical attachments but frequently require division during surgical resections. At its distal end the sigmoid passes to the midline and at the region around the sacral promontary it becomes the upper rectum. This transition is visible macroscopically as the point where the teniae fuse. More distally the rectum passes through the peritoneum at the region of the peritoneal reflection and becomes extraperitoneal. Arterial supply Superior mesenteric artery and inferior mesenteric artery: linked by the marginal artery. Ascending colon: ileocolic and right colic arteries Transverse colon: middle colic artery Descending and sigmoid colon: inferior mesenteric artery Venous drainage From regional veins (that accompany arteries) to superior and inferior mesenteric vein Lymphatic drainage Initially along nodal chains that accompany supplying arteries, then para-aortic nodes. Embryology Midgut- Second part of duodenum to 2/3 transverse colon Hindgut- Distal 1/3 transverse colon to anus Peritoneal location The right and left colon are part intraperitoneal and part extraperitoneal. The sigmoid and transverse colon are generally wholly intraperitoneal. This has implications for the sequelae of perforations, which will tend to result in generalised peritonitis in the wholly intra peritoneal segments. Colonic relations Region of colon Relation Caecum/ right colon Right ureter, gonadal vessels Hepatic flexure Gallbladder (medially) Splenic flexure Spleen and tail of pancreas Distal sigmoid/ upper rectum Left ureter Rectum Ureters, autonomic nerves, seminal vesicles, prostate, urethra (distally)

Answer 1807

Severe systemic disease of this nature is a constant threat to life. Especially as he also has evidence of cardiac failure. American Society of anesthesiologists physical status scoring system (ASA) ASA grade Description 1 No organic physiological, biochemical or psychiatric disturbance. The surgical pathology is localised and has not invoked systemic disturbance 2 Mild or moderate systemic disruption caused either by the surgical disease process or though underlying pre-existing disease 3 Severe systemic disruption caused either by the surgical pathology or pre-existing disease 4 Patient has severe systemic disease that is a constant threat to life 5 A patient who is moribund and will not survive without surgery

Answer 1808

The biceps femoris is commonly injured in sports that require explosive bending of the knee as seen in sprinting, especially if the athlete has not warmed up first. Avulsion most commonly occurs where the long head attaches to the ischial tuberosity. Injuries to biceps femoris are more common than to the other hamstrings. Biceps femoris The biceps femoris is one of the hamstring group of muscles located in the posterior upper thigh. It has two heads. Long head Origin Ischial tuberosity Insertion Fibular head Action Knee flexion, lateral rotation tibia, extension hip Innervation Tibial division of sciatic nerve (L5, S1, S2) Arterial supply Profunda femoris artery, inferior gluteal artery, and the superior muscular branches of popliteal artery Short head Origin Lateral lip of linea aspera, lateral supracondylar ridge of femur Insertion Fibular head Action Knee flexion, lateral rotation tibia Innervation Common peroneal division of sciatic nerve (L5, S1, S2) Arterial supply Profunda femoris artery, inferior gluteal artery, and the superior muscular branches of popliteal artery

Answer 1809

The quadriceps femoris lies in the anterior compartment. Fascial compartments of the leg Compartments of the thigh Formed by septae passing from the femur to the fascia lata. Compartment Nerve Muscles Blood supply Anterior compartment Femoral Iliacus Tensor fasciae latae Sartorius Quadriceps femoris Femoral artery Medial compartment Obturator Adductor longus/magnus/brevis Gracilis Obturator externus Profunda femoris artery and obturator artery Posterior compartment (2 layers) Sciatic Semimembranosus Semitendinosus Biceps femoris Branches of Profunda femoris artery Compartments of the lower leg Separated by the interosseous membrane (anterior and posterior compartments), anterior fascial septum (separate anterior and lateral compartments) and posterior fascial septum (separate lateral and posterior compartments) Compartment Nerve Muscles Blood supply Anterior compartment Deep peroneal nerve Tibialis anterior Extensor digitorum longus Extensor hallucis longus Peroneus tertius Anterior tibial artery Posterior compartment Tibial Muscles: deep and superficial compartments (separated by deep transverse fascia) Deep: Flexor hallucis longus, Flexor digitalis longus, Tibialis posterior, Popliteus Superficial: Gastrocnemius, Soleus, Plantaris Posterior tibial Lateral compartment Superficial peroneal Peroneus longus/brevis Peroneal artery

Answer 1810

Profuse vomiting and diarrhoea are rare in early appendicitis Whilst patients may vomit once or twice, profuse vomiting is unusual, and would fit more with gastroenteritis or an ileus. A trace of protein is not an uncommon occurrence in acute appendicitis. A free lying pelvic appendix may result in localised bladder irritation, with inflammation occurring as a secondary phenomena. This latter feature may result in patients being incorrectly diagnosed as having a urinary tract infection. A urine dipstick test is useful in differentiating between the two conditions. Appendicitis History Peri umbilical abdominal pain (visceral stretching of appendix lumen and appendix is mid gut structure) radiating to the right iliac fossa due to localised parietal peritoneal inflammation. Vomit once or twice but marked and persistent vomiting is unusual. Diarrhoea is rare. However, pelvic appendicitis may cause localised rectal irritation and some loose stools. A pelvic abscess may also cause diarrhoea. Mild pyrexia is common - temperature is usually 37.5 -38oC. Higher temperatures are more typical of conditions like mesenteric adenitis. Anorexia is very common. It is very unusual for patients with appendicitis to be hungry. Examination Generalised peritonitis if perforation has occurred or localised peritonism. Retrocaecal appendicitis may have relatively few signs. Digital rectal examination may reveal boggy sensation if pelvic abscess is present, or even tenderness with a pelvic appendix. Diagnosis Typically raised inflammatory markers coupled with compatible history and examination findings should be enough to justify appendicectomy. Urine analysis may show mild leucocytosis but no nitrites. Ultrasound is useful in females where pelvic organ pathology is suspected. Although it is not always possible to visualise the appendix on ultrasound, the presence of free fluid (always pathological in males) should raise suspicion. Treatment Appendicectomy which can be performed via either an open or laparoscopic approach. Administration of metronidazole reduces wound infection rates. Patients with perforated appendicitis require copious abdominal lavage. Patients without peritonitis who have an appendix mass should receive broad spectrum antibiotics and consideration given to performing an interval appendicectomy. Be wary in the older patients who may have either an underlying caecal malignancy or perforated sigmoid diverticular disease.

Answer 1811

Le Fort II fractures have a pyramidal shape. The fracture line involves the orbit and extends to involve the bridge of the nose and the ethmoids. In continues to involve the infraorbital rim and usually through the infraorbital foramen. As a result infraorbital parasthesia, palatal mobility and malocclusion are common findings. Severe fractures may result in enopthalmos. However, the fracture does not, by definition, involve the inferior alveolar nerve. Craniomaxillofacial injuries Craniomaxillofacial injuries in the UK are due to: Interpersonal violence (52%) Motor vehicle accidents (16%) Sporting injuries (19%) Falls (11%) Le Fort Fractures Grade Feature Le Fort 1 The fracture extends from the nasal septum to the lateral pyriform rims, travels horizontally above the teeth apices, crosses below the zygomaticomaxillary junction, and traverses the pterygomaxillary junction to interrupt the pterygoid plates. Le Fort 2 These fractures have a pyramidal shape and extend from the nasal bridge at or below the nasofrontal suture through the frontal process of the maxilla, inferolaterally through the lacrimal bones and inferior orbital floor and rim through or near the inferior orbital foramen, and inferiorly through the anterior wall of the maxillary sinus; it then travels under the zygoma, across the pterygomaxillary fissure, and through the pterygoid plates. Le Fort 3 These fractures start at the nasofrontal and frontomaxillary sutures and extend posteriorly along the medial wall of the orbit through the nasolacrimal groove and ethmoid bones. The thicker sphenoid bone posteriorly usually prevents continuation of the fracture into the optic canal. Instead, the fracture continues along the floor of the orbit along the inferior orbital fissure and continues superolaterally through the lateral orbital wall, through the zygomaticofrontal junction and the zygomatic arch. Intranasally, a branch of the fracture extends through the base of the perpendicular plate of the ethmoid, through the vomer, and through the interface of the pterygoid plates to the base of the sphenoid. This type of fracture predisposes the patient to CSF rhinorrhea more commonly than the other types. Ocular injuries Superior orbital fissure syndrome Severe force to the lateral wall of the orbit resulting in compression of neurovascular structures. Results in : Complete opthalmoplegia and ptosis (Cranial nerves 3, 4, 6 and nerve to levator palpebrae superioris) Relative afferent pupillary defect Dilatation of the pupil and loss of accommodation and corneal reflexes Altered sensation from forehead to vertex (frontal branch of trigeminal nerve) Orbital blow out fracture Typically occurs when an object of slightly larger diameter than the orbital rim strikes the incompressible eyeball. The bone fragment is displaced downwards into the antral cavity, remaining attached to the orbital periosteum. Periorbital fat may be herniated through the defect, interfering with the inferior rectus and inferior oblique muscles which are contained within the same fascial sheath. This prevents upward movement and outward rotation of the eye and the patient experiences diplopia on upward gaze. The initial bruising and swelling may make assessment difficult and patients should usually be reviewed 5 days later. Residual defects may require orbital floor reconstruction. Nasal Fractures Common injury Ensure new and not old deformity Control epistaxis CSF rhinorrhoea implies that the cribriform plate has been breached and antibiotics will be required. Usually best to allow bruising and swelling to settle and then review patient clinically. Major persistent deformity requires fracture manipulation, best performed within 10 days of injury. Retrobulbar haemorrhage Rare but important ocular emergency. Presents with: Pain (usually sharp and within the globe) Proptosis Pupil reactions are lost Paralysis (eye movements lost) Visual acuity is lost (colour vision is lost first) May be the result of Le Fort type facial fractures. Management: Mannitol 1g/Kg as 20% infusion, Osmotic diuretic, Contra-indicated in congestive heart failure and pulmonary oedema Acetazolamide 500mg IV, (Monitor FBC/U+E) Reduces aqueous pressure by inhibition of carbonic anhydrase (used in glaucoma) Dexamethasone 8mg orally or intravenously In a traumatic setting an urgent cantholysis may be needed prior to definitive surgery. Consider Papaverine 40mg smooth muscle relaxant Dextran 40 500mls IV improves perfusion

Answer 1812

Neutrophil polymorphs=Acute inflammation. Granuloma = Chronic inflammation. Acute inflammation: 3 phases 1. Changes in blood vessel and flow: flush, flare, wheal 2. Fluid exudates (rich in protein i.e. Ig, coagulation factors) produced via increased vascular permeability 3. Cellular exudates mainly containing neutrophil polymorphs pass into extravascular space. Neutrophils are then transported to tissues via: a. Margination of neutrophils to the peripheral plasmatic of the vessel rather than the central axial stream b. Pavementing: Adhesion of neutrophils to endothelial cells in venules at site of acute inflammation c. Emigration: neutrophils pass between endothelial cells into the tissue Acute inflammation Inflammation is the reaction of the tissue elements to injury. Vascular changes occur, resulting in the generation of a protein rich exudate. So long as the injury does not totally destroy the existing tissue architecture, the episode may resolve with restoration of original tissue architecture. Vascular changes Vasodilation occurs and persists throughout the inflammatory phase. Inflammatory cells exit the circulation at the site of injury. The equilibrium that balances Starlings forces within capillary beds is disrupted and a protein rich exudate will form as the vessel walls also become more permeable to proteins. The high fibrinogen content of the fluid may form a fibrin clot. This has several important immunomodulatory functions. Sequelae Resolution Typically occurs with minimal initial injury Stimulus removed and normal tissue architecture results Organisation Delayed removal of exudate Tissues undergo organisation and usually fibrosis Suppuration Typically formation of an abscess or an empyema Sequestration of large quantities of dead neutrophils Progression to chronic inflammation Coupled inflammatory and reparative activities Usually occurs when initial infection or suppuration has been inadequately managed Causes Infections e.g. Viruses, exotoxins or endotoxins released by bacteria Chemical agents Physical agents e.g. Trauma Hypersensitivity reactions Tissue necrosis Presence of neutrophil polymorphs is a histological diagnostic feature of acute inflammation

Answer 1813

The early difficulty in intubation is most likely to be the result of pharyngeal pouch. Schatzki rings can cause problems but can usually be visualized. Whilst a squamous cell carcinoma can be perforated, it would be unusual for this to occur spontaneously as perforation of cancer typically occurs after attempted therapeutic intervention. Oesophageal disease Disorder Features Mallory-Weiss Tear Usually history of antecedent vomiting. This is then followed by the vomiting of a small amount of blood. There is usually little in the way of systemic disturbance or prior symptoms. Hiatus hernia of gastric cardia Often longstanding history of dyspepsia, patients are often overweight. Uncomplicated hiatus hernias should not be associated with dysphagia or haematemesis. Oesophageal rupture Complete disruption of the oesophageal wall in absence of pre-existing pathology. Left postero-lateral oesophageal is commonest site (2-3cm from OG junction). Suspect in patients with severe chest pain without cardiac diagnosis and signs suggestive of pneumonia without convincing history, where there is history of vomiting. Erect CXR shows infiltrate or effusion in 90% of cases(1). Squamous cell carcinoma of the oesophagus History of progressive dysphagia. Often signs of weight loss. Usually little or no history of previous GORD type symptoms. Adenocarcinoma of the oesophagus Progressive dysphagia, may have previous symptoms of GORD or Barretts oesophagus. Peptic stricture Longer history of dysphagia, often not progressive. Usually symptoms of GORD. Often lack systemic features seen with malignancy Dysmotility disorder May have dysphagia that is episodic and non progressive. Retrosternal pain may accompany the episodes. Diagnosis Most of the differential diagnoses listed above can be accurately categorised by upper GI endoscopy (usually most patients). Where this fails to demonstrate a mechanical stricture the use of pH and manometry studies together with radiological contrast swallows will facilitate the diagnosis. References Blencowe N et al. Spontaneous oesophageal rupture. BMJ 2013 (346):38-39.

Answer 1814

The ureter develops from an outpouching that arises from the mesonephric duct. The mesonephric duct is associated with the metanephric duct that develops within the metenephrogenic blastema. This forms the site of the ureteric bud which branches off the mesonephric duct. Ureter 25-35 cm long Muscular tube lined by transitional epithelium Surrounded by thick muscular coat. Becomes 3 muscular layers as it crosses the bony pelvis Retroperitoneal structure overlying transverse processes L2-L5 Lies anterior to bifurcation of iliac vessels Blood supply is segmental; renal artery, aortic branches, gonadal branches, common iliac and internal iliac Lies beneath the uterine artery

Answer 1815

The 11th and 12th ribs lie posterior to the kidneys and may be encountered during a posterior approach. A pneumothorax is a recognised complication of this type of surgery. Renal anatomy Each kidney is about 11cm long, 5cm wide and 3cm thick. They are located in a deep gutter alongside the projecting vertebral bodies, on the anterior surface of psoas major. In most cases the left kidney lies approximately 1.5cm higher than the right. The upper pole of both kidneys approximates with the 11th rib (beware pneumothorax during nephrectomy). On the left hand side the hilum is located at the L1 vertebral level and the right kidney at level L1-2. The lower border of the kidneys is usually alongside L3. The table below shows the anatomical relations of the kidneys: Relations Relations Right Kidney Left Kidney Posterior Quadratus lumborum, diaphragm, psoas major, transversus abdominis Quadratus lumborum, diaphragm, psoas major, transversus abdominis Anterior Hepatic flexure of colon Stomach, Pancreatic tail Superior Liver, adrenal gland Spleen, adrenal gland Fascial covering Each kidney and suprarenal gland is enclosed within a common layer of investing fascia, derived from the transversalis fascia. It is divided into anterior and posterior layers (Gerotas fascia). Renal structure Kidneys are surrounded by an outer cortex and an inner medulla which usually contains between 6 and 10 pyramidal structures. The papilla marks the innermost apex of these. They terminate at the renal pelvis, into the ureter. Lying in a hollow within the kidney is the renal sinus. This contains: 1. Branches of the renal artery 2. Tributaries of the renal vein 3. Major and minor calyces's 4. Fat Structures at the renal hilum The renal vein lies most anteriorly, then renal artery (it is an end artery) and the ureter lies most posterior.

Answer 1816

The Denonvilliers fascia separates the rectum from the prostate. Waldeyers fascia separates the rectum from the sacrum Prostate gland The prostate gland is approximately the shape and size of a walnut and is located inferior to the bladder. It is separated from the rectum by Denonvilliers fascia and its blood supply is derived from the internal iliac vessels (via inferior vesical artery). The internal sphincter lies at the apex of the gland and may be damaged during prostatic surgery, affected individuals may complain of retrograde ejaculation. Summary of prostate gland Arterial supply Inferior vesical artery (from internal iliac) Venous drainage Prostatic venous plexus (to paravertebral veins) Lymphatic drainage Internal iliac nodes Innervation Inferior hypogastric plexus Dimensions Transverse diameter (4cm) AP diameter (2cm) Height (3cm) Lobes Posterior lobe: posterior to urethra Median lobe: posterior to urethra, in between ejaculatory ducts Lateral lobes x 2 Isthmus Zones Peripheral zone: subcapsular portion of posterior prostate. Most prostate cancers are here Central zone Transition zone Stroma Relations Anterior Pubic symphysis Prostatic venous plexus Posterior Denonvilliers fascia Rectum Ejaculatory ducts Lateral Venous plexus (lies on prostate) Levator ani (immediately below the puboprostatic ligaments)

Answer 1817

The genitofemoral nerve divides into two branches as it approaches the inguinal ligament. The genital branch passes anterior to the external iliac artery through the deep inguinal ring into the inguinal canal. It communicates with the ilioinguinal nerve in the inguinal canal (though this is seldom of clinical significance). Genitofemoral nerve Supplies Small area of the upper medial thigh. Path Arises from the first and second lumbar nerves. Passes obliquely through psoas major, and emerges from its medial border opposite the fibrocartilage between the third and fourth lumbar vertebrae. It then descends on the surface of psoas major, under cover of the peritoneum Divides into genital and femoral branches. The genital branch passes through the inguinal canal, within the spermatic cord, to supply the skin and fascia of the scrotum. The femoral branch enters the thigh posterior to the inguinal ligament, lateral to the femoral artery. It supplies an area of skin and fascia over the femoral triangle. It may be injured during abdominal or pelvic surgery, or during inguinal hernia repairs.

Answer 1818

The femoral nerve supplies the quadriceps muscle which is responsible for extension at the knee joint. Femoral nerve Root values L2, 3, 4 Innervates Pectineus Sartorius Quadriceps femoris Vastus lateralis/medialis/intermedius Rectus femoris Branches Medial cutaneous nerve of thigh Saphenous nerve Intermediate cutaneous nerve of thigh Path Penetrates psoas major and exits the pelvis by passing under the inguinal ligament to enter the femoral triangle, lateral to the femoral artery and vein. Mnemonic for femoral nerve supply (don't) M I S V Q Scan for PE M edial cutaneous nerve of the thigh I ntermediate cutaneous nerve of the thigh S aphenous nerve V astus Q uadriceps femoris S artorius PE ectineus

Answer 1819

The sural nerve exits at the lower infero-lateral aspect of the fossa and is more at risk in short saphenous vein surgery. The tibial nerve lies more medially and is even less likely to be injured in this location. Popliteal fossa Boundaries of the popliteal fossa Laterally Biceps femoris above, lateral head of gastrocnemius and plantaris below Medially Semimembranosus and semitendinosus above, medial head of gastrocnemius below Floor Popliteal surface of the femur, posterior ligament of knee joint and popliteus muscle Roof Superficial and deep fascia Contents Popliteal artery and vein Small saphenous vein Common peroneal nerve Tibial nerve Posterior cutaneous nerve of the thigh Genicular branch of the obturator nerve Lymph nodes

Answer 1820

Between 500 mL and 1.5 L of bile enters the small bowel daily. Most bile salts are recycled by the enterohepatic circulation. When the gallbladder contracts the lumenal pressure is approximately 25cm water, which is why biliary colic may be so painful. Bile Bile is produced at a rate of between 500ml and 1500mL per day. Bile is composed of bile salts, bicarbonate, cholesterol, steroids and water. There are three main factors regulating bile flow; hepatic secretion, gall bladder contraction and sphincter of oddi resistance. Bile salts are absorbed in the terminal ileum (and recycled to the liver). Over 90% of all bile salts are recycled in this way, such that the total pool of bile salts is recycled up to six times a day. Primary bile salts Cholate and chenodeoxycholate. Secondary bile salts Formed by bacterial action on primary bile salts. These are deoxycholate and lithocholate. Of these deoxycholate is reabsorbed, whilst lithocholate is insoluble and excreted. Pathophysiology of gallstones Bile salts have a detergent action. They aggregate to form micelles and these have a lipid centre in which fats may be transported. Excessive quantities of cholesterol cannot be transported in this way and will tend to precipitate, resulting in the formation of cholesterol rich gallstones.

Answer 1821

Iatrogenic perforations of the oesophagus may be managed non operatively. This usually involves a nil by mouth regime, tube thoracostomy may be needed. Total parenteral nutrition is the safest option. Insertion of NG feeding tubes and PEG tubes may complicate the process or allow feed to enter the perforation site. Nutrition options in surgical patients Oral intake Easiest option May be supplemented by calorie rich dietary supplements May contra indicated following certain procedures Naso gastric feeding Usually administered via fine bore naso gastric feeding tube Complications relate to aspiration of feed or misplaced tube May be safe to use in patients with impaired swallow Often contra indicated following head injury due to risks associated with tube insertion Naso jejunal feeding Avoids problems of feed pooling in stomach (and risk of aspiration) Insertion of feeding tube more technically complicated (easiest if done intra operatively) Safe to use following oesophagogastric surgery Feeding jejunostomy Surgically sited feeding tube May be used for long term feeding Low risk of aspiration and thus safe for long term feeding following upper GI surgery Main risks are those of tube displacement and peritubal leakage immediately following insertion, which carries a risk of peritonitis Percutaneous endoscopic gastrostomy Combined endoscopic and percutaneous tube insertion May not be technically possible in those patients who cannot undergo successful endoscopy Risks include aspiration and leakage at the insertion site Total parenteral nutrition The definitive option in those patients in whom enteral feeding is contra indicated Individualised prescribing and monitoring needed Should be administered via a central vein as it is strongly phlebitic Long term use is associated with fatty liver and deranged LFT's

Answer 1822

Intestinal malrotation with volvulus is treated with a Ladd's procedure Kasai procedure A surgery that removes damaged and blocked bile ducts and replaces the structures with a segment of the small intestine. Often used as a bridge towards liver transplant. It is the treatment of choice for neonates with biliary atresia. A Pyloromyotomy or Ramstedt's procedure is where the muscle of the pylorus (at the end of the stomach) is divided to allow normal stomach emptying. Bilious vomiting in neonates Causes of intestinal obstruction with bilious vomiting in neonates Disorder Incidence and causation Age at presentation Diagnosis Treatment Duodenal atresia 1 in 5000 (higher in Downs syndrome) Few hours after birth AXR shows 'double bubble sign, contrast study may confirm Duodenoduodenostomy Malrotation with volvulus Usually cause by incomplete rotation during embryogenesis Usually 3-7 days after birth, volvulus with compromised circulation may result in peritoneal signs and haemodynamic instability Upper GI contrast study may show DJ flexure is more medially placed, USS may show abnormal orientation of SMA and SMV Ladd's procedure Jejunal/ ileal atresia Usually caused by vascular insufficiency in utero, usually 1 in 3000 Usually within 24 hours of birth AXR will show air-fluid levels Laparotomy with primary resection and anastomosis Meconium ileus Occurs in between 15 and20% of those babies with cystic fibrosis, otherwise 1 in 5000 Typically in first 24-48 hours of life with abdominal distension and bilious vomiting Air - fluid levels on AXR, sweat test to confirm cystic fibrosis Surgical decompression, serosal damage may require segmental resection Necrotising enterocolitis Up to 2.4 per 1000 births, risks increased in prematurity and inter-current illness Usually second week of life Dilated bowel loops on AXR, pneumatosis and portal venous air Conservative and supportive for non perforated cases, laparotomy and resection in cases of perforation of ongoing clinical deterioration

Answer 1823

Renal adenocarcinoma is the most common variant and is associated with polycythaemia. Haematuria Causes of haematuria Trauma Injury to renal tract Renal trauma commonly due to blunt injury (others penetrating injuries) Ureter trauma rare: iatrogenic Bladder trauma: due to RTA or pelvic fractures Infection Remember TB Malignancy Renal cell carcinoma (remember paraneoplastic syndromes): painful or painless Urothelial malignancies: 90% are transitional cell carcinoma, can occur anywhere along the urinary tract. Painless haematuria. Squamous cell carcinoma and adenocarcinoma: rare bladder tumours Prostate cancer Penile cancers: SCC Renal disease Glomerulonephritis Stones Microscopic haematuria common Structural abnormalities Benign prostatic hyperplasia (BPH) causes haematuria due to hypervascularity of the prostate gland Cystic renal lesions e.g. polycystic kidney disease Vascular malformations Renal vein thrombosis due to renal cell carcinoma Coagulopathy Causes bleeding of underlying lesions Drugs Cause tubular necrosis or interstitial nephritis: aminoglycosides, chemotherapy Interstitial nephritis: penicillin, sulphonamides, and NSAIDs Anticoagulants Benign Exercise Gynaecological Endometriosis: flank pain, dysuria, and haematuria that is cyclical Iatrogenic Catheterisation Radiotherapy; cystitis, severe haemorrhage, bladder necrosis Pseudohaematuria For example following consumption of beetroot References Http://bestpractice.bmj.com/best-practice/monograph/316/overview/aetiology.html

Answer 1824

This can be a challenging question. A particularly careless surgeon could encounter all of these. However, during a routine level 1 axillary exploration which is where the majority of sentinel nodes will be located, the nerves most commonly encountered are the intercostobrachial nerves. Axilla Boundaries of the axilla Medially Chest wall and Serratus anterior Laterally Humeral head Floor Subscapularis Anterior aspect Lateral border of Pectoralis major Fascia Clavipectoral fascia Content: Long thoracic nerve (of Bell) Derived from C5-C7 and passes behind the brachial plexus to enter the axilla. It lies on the medial chest wall and supplies serratus anterior. Its location puts it at risk during axillary surgery and damage will lead to winging of the scapula. Thoracodorsal nerve and thoracodorsal trunk Innervate and vascularise latissimus dorsi. Axillary vein Lies at the apex of the axilla, it is the continuation of the basilic vein. Becomes the subclavian vein at the outer border of the first rib. Intercostobrachial nerves Traverse the axillary lymph nodes and are often divided during axillary surgery. They provide cutaneous sensation to the axillary skin. Lymph nodes The axilla is the main site of lymphatic drainage for the breast.

Answer 1825

Sudden onset of abdominal pain and forceful bowel evacuation are features of acute mesenteric infarct. The SMA is more likely to be involved than the IMA and that makes this the most likely diagnosis. Severe vomiting is not commonly seen with clostridium difficile infection. Mesenteric vessel disease Mesenteric ischaemia accounts for 1 in 1000 acute surgical admissions. It is primarily caused by arterial embolism resulting in infarction of the colon. It is more likely to occur in areas such as the splenic flexure that are located at the borders of the territory supplied by the superior and inferior mesenteric arteries. Types Acute mesenteric embolus (commonest 50%) Sudden onset abdominal pain followed by profuse diarrhoea. May be associated with vomiting. Rapid clinical deterioration. Serological tests: WCC, lactate, amylase may all be abnormal particularly in established disease. These can be normal in the early phases. Acute on chronic mesenteric ischaemia Usually longer prodromal history. Post prandial abdominal discomfort and weight loss are dominant features. Patients will usually present with an acute on chronic event, but otherwise will tend not to present until mesenteric flow is reduced by greater than 80%. When acute thrombosis occurs presentation may be as above. In the chronic setting the symptoms will often be those of ischaemic colitis (mucosa is the most sensitive area to this insult). Mesenteric vein thrombosis Usually a history over weeks. Overt abdominal signs and symptoms will not occur until venous thrombosis has reached a stage to compromise arterial inflow. Thrombophilia accounts for 60% of cases. Low flow mesenteric infarction This occurs in patients with multiple co morbidities in whom mesenteric perfusion is significantly compromised by overuse of inotropes or background cardiovascular compromise. The end result is that the bowel is not adequately perfused and infarcts occur from the mucosa outwards. Diagnosis Serological tests: WCC, lactate, CRP, amylase (can be normal in early disease). Cornerstone for diagnosis of arterial AND venous mesenteric disease is CT angiography scanning in the arterial phase with thin slices (<5mm). Venous phase contrast is not helpful. SMA duplex USS is useful in the evaluation of proximal SMA disease in patients with chronic mesenteric ischaemia. MRI is of limited use due to gut peristalsis and movement artefact. Management Overt signs of peritonism: Laparotomy Mesenteric vein thrombosis: If no peritonism: Medical management with IV heparin At operation limited resection of frankly necrotic bowel with view to relook laparotomy at 24-48h. In the interim urgent bowel revascularisation via endovascular (preferred) or surgery. Prognosis Overall poor. Best outlook is from an acute ischaemia from an embolic event where surgery occurs within 12h. Survival may be 50%. This falls to 30% with treatment delay. The other conditions carry worse survival figures.

Answer 1826

Mnemonic for the nerves passing through the supraorbital fissure: Live Frankly To See Absolutely No Insult Lacrimal Frontal Trochlear Superior Division of Oculomotor Abducens Nasociliary Inferior Division of Oculomotor nerve The opthalmic artery arises from the internal carotid immediately after it has pierced the dura and arachnoid. It runs through the optic canal below the optic nerve and within its dural and arachnoid sheaths. It terminates as the supratrochlear and dorsal nasal arteries.

Answer 1827

In a child of this age, with the symptoms described a nephroblastoma is the most likely diagnosis. A perinephric abscess is most unlikely. If an abscess were to occur it would be confined to Gerotas fascia in the first instance, and hence anterior extension would be unlikely. Nephroblastoma Nephroblastoma (Wilms tumours) Usually present in first 4 years of life May often present as a mass associated with haematuria (pyrexia may occur in 50%) Often metastasise early (usually to lung) Treated by nephrectomy Younger children have better prognosis (<1 year of age =80% overall 5 year survival)

Answer 1828

This man has developed an acute dystonic reaction. Administration of further anti dopaminergic drugs will worsen the situation. Procyclidine will help to reverse the event. This is most likely to have occurred because the patient is on long term anti psychotics and has then received metoclopramide. Acute dystonic reaction The anti dopaminergic drugs (such as antipsychotics) may result in extrapyramidal side effects. These may range from mild parkinsonian symptoms such as resting tremor and bradykinesia. Through to acute dystonic reactions which are characterised by abnormal and involuntary facial and bodily movements, such as spasmodic torticollis, oculogyric crisis and oromandibular dystonia. Chronic cases are generally only encountered in psychiatric units. In surgical practice the administration of the anti dopaminergic drug metoclopramide may be sufficient to precipitate an attack. Treatment may be required if symptoms are sufficiently troublesome; benzhexol and procyclidine are two drugs which may be used.

Answer 1829

As this man is relatively young and has full thickness prolapse a rectopexy is the most appropriate procedure. It will give the lowest recurrence rates. This could be a sutured rectopexy or ventral mesh rectopexy. If the latter procedure is adopted, it is important to counsel the patient around the risks of sexual dysfunction (close to prostate). Rectal prolapse Rectal prolapse may be divided into internal and external prolapse. Patients with the former condition may have internal intussceception of the rectum and present with constipation, obstructed defecation and occasionally faecal incontinence. Patients with external rectal prolapse have a full thickness external protrusion of the rectum. Risk factors for the condition include multiparity, pelvic floor trauma and connective tissue disorders. Diagnosis External prolapse is usually evident. Internal prolapse may be identified by defecating proctography and examination under anaesthesia. Sinister pathology should be excluded with endoscopy Treatment Perineal approaches include the Delormes operation, this avoids resection and is relatively safe but is associated with high recurrence rates. An Altmeirs operation involves a perineal excision of the sigmoid colon and rectum, it may be a more effective procedure than a Delormes but carries the risk of anastomotic leak. Rectopexy - this is an abdominal procedure. The rectum is mobilised and fixed onto the sacral promontary. A prosthetic mesh may be inserted. The recurrence rates are low and the procedure is well tolerated (particularly if performed laparoscopically). Risks with ventral mesh rectopexy include chronic pain and visceral mesh erosions. Thirsch tape- this is a largely historical procedure and involves encircling the rectum with tape or wire. It may be of use in a palliative setting.

Answer 1830

A Rutherford Morrison incision is the traditional approach for a renal transplant and provides extra peritoneal access to the iliac vessels. Abdominal incisions Midline incision Commonest approach to the abdomen Structures divided: linea alba, transversalis fascia, extraperitoneal fat, peritoneum (avoid falciform ligament above the umbilicus) Bladder can be accessed via an extraperitoneal approach through the space of Retzius Paramedian incision Parallel to the midline (about 3-4cm) Structures divided/retracted: anterior rectus sheath, rectus (retracted), posterior rectus sheath, transversalis fascia, extraperitoneal fat, peritoneum Incision is closed in layers Battle Similar location to paramedian but rectus displaced medially (and thus denervated) Now seldom used Kocher's Incision under right subcostal margin e.g. Cholecystectomy (open) Lanz Incision in right iliac fossa e.g. Appendicectomy Gridiron Oblique incision centered over McBurneys point- usually appendicectomy (less cosmetically acceptable than Lanz Gable Rooftop incision Pfannenstiel's Transverse supra pubic, primarily used to access pelvic organs McEvedy's Groin incision e.g. Emergency repair strangulated femoral hernia Rutherford Morrison Extraperitoneal approach to left or right lower quadrants. Gives excellent access to iliac vessels and is the approach of choice for first time renal transplantation.

Answer 1831

The combination of age, female gender and steroids coupled with hip pain on minor trauma are strongly suggestive of osteoporosis complicated by pathological fracture. Bone disease Disease Features Treatment Pagets Focal bone resorption followed by excessive and chaotic bone deposition Affects (in order): spine, skull, pelvis and femur Serum alkaline phosphatase raised (other parameters normal) Abnormal thickened, sclerotic bone on x-rays Risk of cardiac failure with >15% bony involvement Small risk of sarcomatous change Bisphosphonates Osteoporosis Excessive bone resorption resulting in demineralised bone Commoner in old age Increased risk of pathological fracture, otherwise asymptomatic Alkaline phosphatase normal, calcium normal Bisphosphonates, calcium and vitamin D Secondary bone tumours Bone destruction and tumour infiltration Mirel scoring used to predict risk of fracture Appearances depend on primary (e.g.sclerotic - prostate, lytic - breast) Elevated serum calcium and alkaline phosphatase may be seen Radiotherapy, prophylactic fixation and analgesia

Answer 1832

Athletic boys and girls may develop this condition in their teenage years. It is caused by multiple micro fractures at the point of insertion of the tendon into the tibial tuberosity. Most cases settle with physiotherapy and rest. Knee injury Types of injury Ruptured anterior cruciate ligament Sport injury Mechanism: high twisting force applied to a bent knee Typically presents with: loud crack, pain and RAPID joint swelling (haemoarthrosis) Poor healing Management: intense physiotherapy or surgery Ruptured posterior cruciate ligament Mechanism: hyperextension injuries Tibia lies back on the femur Paradoxical anterior draw test Rupture of medial collateral ligament Mechanism: leg forced into valgus via force outside the leg Knee unstable when put into valgus position Menisceal tear Rotational sporting injuries Delayed knee swelling Joint locking (Patient may develop skills to 'unlock' the knee Recurrent episodes of pain and effusions are common, often following minor trauma Chondromalacia patellae Teenage girls, following an injury to knee e.g. Dislocation patella Typical history of pain on going downstairs or at rest Tenderness, quadriceps wasting Dislocation of the patella Most commonly occurs as a traumatic primary event, either through direct trauma or through severe contraction of quadriceps with knee stretched in valgus and external rotation Genu valgum, tibial torsion and high riding patella are risk factors Skyline x-ray views of patella are required, although displaced patella may be clinically obvious An osteochondral fracture is present in 5% The condition has a 20% recurrence rate Fractured patella 2 types: i. Direct blow to patella causing undisplaced fragments ii. Avulsion fracture Tibial plateau fracture Occur in the elderly (or following significant trauma in young) Mechanism: knee forced into valgus or varus, but the knee fractures before the ligaments rupture Varus injury affects medial plateau and if valgus injury, lateral plateau depressed fracture occurs Classified using the Schatzker system (see below) Schatzker Classification system for tibial plateau fractures Type Anatomical description Features 1 Vertical split of lateral condyle Fracture through dense bone, usually in the young. It may be virtually undisplaced, or the condylar fragment may be pushed inferiorly and tilted 2 Vertical split of the lateral condyle combined with an adjacent load bearing part of the condyle The wedge fragment (which may be of variable size), is displaced laterally; the joint is widened. Untreated, a valgus deformity may develop 3 Depression of the articular surface with intact condylar rim The split does not extend to the edge of the plateau. Depressed fragments may be firmly embedded in subchondral bone, the joint is stable 4 Fragment of the medial tibial condyle Two injuries are seen in this category; (1) a depressed fracture of osteoporotic bone in the elderly. (2) a high energy fracture resulting in a condylar split that runs from the intercondylar eminence to the medial cortex. Associated ligamentous injury may be severe 5 Fracture of both condyles Both condyles fractured but the column of the metaphysis remains in continuity with the tibial shaft 6 Combined condylar and subcondylar fractures High energy fracture with marked comminution

Answer 1833

A pseudocyst is a late complication of pancreatitis and is managed in the elective setting. Drainage of this man's pseudocyst is required. This could be accomplished radiologically or endoscopically or surgically. As the other options are not on the list this is the best option from those available. Management of Pancreatitis Management of Acute Pancreatitis in the UK Diagnosis Traditionally hyperamylasaemia has been utilised with amylase being elevated three times the normal range. However, amylase may give both false positive and negative results. Serum lipase is both more sensitive and specific than serum amylase. It also has a longer half life. Serum amylase levels do not correlate with disease severity. Differential causes of hyperamylasaemia Acute pancreatitis Pancreatic pseudocyst Mesenteric infarct Perforated viscus Acute cholecystitis Diabetic ketoacidosis Assessment of severity Glasgow, Ranson scoring systems and APACHE II Biochemical scoring e.g. using CRP Features that may predict a severe attack within 48 hours of admission to hospital Initial assessment Clinical impression of severity Body mass index >30 Pleural effusion APACHE score >8 24 hours after admission Clinical impression of severity APACHE II >8 Glasgow score of 3 or more Persisting multiple organ failure CRP>150 48 hours after admission Glasgow Score of >3 CRP >150 Persisting or progressive organ failure Table adapted from UK guidelines for management of acute pancreatitis. GUT 2005, 54 suppl III Management Nutrition There is reasonable evidence to suggest that the use of enteral nutrition does not worsen the outcome in pancreatitis Most trials to date were underpowered to demonstrate a conclusive benefit. The rationale behind feeding is that it helps to prevent bacterial translocation from the gut, thereby contributing to the development of infected pancreatic necrosis. Use of antibiotic therapy Many UK surgeons administer antibiotics to patients with acute pancreatitis. However, there is very little evidence to support this practice. A recent Cochrane review highlights the potential benefits of administering Imipenem to patients with established pancreatic necrosis in the hope of averting the progression to infection. There are concerns that the administration of antibiotics in mild attacks of pancreatitis will not affect outcome and may contribute to antibiotic resistance and increase the risks of antibiotic associated diarrhoea. Surgery Patients with acute pancreatitis due to gallstones should undergo early cholecystectomy. Patients with obstructed biliary system due to stones should undergo early ERCP. Patients with extensive necrosis where infection is suspected should usually undergo FNA for culture. Patients with infected necrosis should undergo either radiological drainage or surgical necrosectomy. The choice of procedure depends upon local expertise. References www.bsg.org.uk/pdfworddocs/pancreatic.pdf Antibiotic therapy for prophylaxis against infection of pancreatic necrosis in acute pancreatitis. Villatoro et al. Cochrane Library DOI: 10.1002/14651858.CD002941.pub3. 2010 version.

Answer 1834

Current guidance is that bleeding peptic ulcers should be treated with dual therapeutic modalities. Adrenaline injection should be augmented with an additional therapy such as endoscopic clipping where this is available. Bleeding duodenal ulcers will usually undergo adrenaline injection. This may be augmented by the placement of endoscopic clips or heat therapy with endoscopic heater probes. Following these interventions patients should receive a proton pump inhibitor infusion. Those who re-bleed, may require surgery. For ulcers in this location, laparotomy, duodenotomy and under-running of the ulcer is usually performed. Upper gastrointestinal bleeding Patients may present with the following: Haematemesis and/ or malaena Epigastric discomfort Sudden collapse The extent to which these will occur will depend upon the source. Mortality is higher in patients presenting with haematemesis than malaena alone. Oesophageal bleeding Cause Presenting features Oesophagitis Small volume of fresh blood, often streaking vomit. Malaena rare. Often ceases spontaneously. Usually history of antecedent GORD type symptoms. Cancer Usually small volume of blood, except as pre terminal event with erosion of major vessels. Often associated symptoms of dysphagia and constitutional symptoms such as weight loss. May be recurrent until malignancy managed. Mallory Weiss Tear Typically brisk small to moderate volume of bright red blood following bout of repeated vomiting. Malaena rare. Usually ceases spontaneously. Varices Usually large volume of fresh blood. Swallowed blood may cause malaena. Often associated with haemodynamic compromise. May stop spontaneously but re-bleeds are common until appropriately managed. Gastric Bleeding Cause Presenting features Gastric cancer May be frank haematemesis or altered blood mixed with vomit. Usually prodromal features of dyspepsia and may have constitutional symptoms. Amount of bleeding variable but erosion of major vessel may produce considerable haemorrhage. Dieulafoy Lesion Often no prodromal features prior to haematemesis and malaena, but this arteriovenous malformation may produce quite considerable haemorrhage and may be difficult to detect endoscopically. Diffuse erosive gastritis Usually haematemesis and epigastric discomfort. Usually there is an underlying cause such as recent NSAID usage. Large volume haemorrhage may occur with considerable haemodynamic compromise. Gastric ulcer Small low volume bleeds more common so would tend to present as iron deficiency anaemia. Erosion into a significant vessel may produce considerable haemorrhage and haematemesis. Duodenum Most common cause of major haemorrhage is a posteriorly sited duodenal ulcer. However, ulcers at any site in the duodenum may present with haematemesis, malaena and epigastric discomfort. The pain of duodenal ulcer is slightly different to that of gastric ulcers and often occurs several hours after eating. Peri ampullary tumours may bleed but these are rare. In patients with previous abdominal aortic aneurysm surgery aorto-enteric fistulation remains a rare but important cause of major haemorrhage associated with high mortality. Management Admission to hospital careful monitoring, cross match blood, check FBC, LFTs, U+E and Clotting (as a minimum) Patients with on-going bleeding and haemodynamic instability are likely to require O negative blood pending cross matched blood Early control of airway is vital (e.g. Drowsy patient with liver failure) Patients with suspected varices should receive terlipressin prior to endoscopy Ideally all patients admitted with upper gastrointestinal haemorrhage should undergo Upper GI endoscopy within 24 hours of admission. In those who are unstable this should occur immediately after resuscitation or in tandem with it. The endoscopy department is a potentially dangerous place for unstable patients and it may be safer to perform the endoscopy in theatre with an anaesthetist present. Varices should be banded or subjected to sclerotherapy. If this is not possible owing to active bleeding then a Sengstaken- Blakemore tube (or Minnesota tube) should be inserted. This should be done with care; gastric balloon should be inflated first and oesophageal balloon second. Remember the balloon will need deflating after 12 hours (ideally sooner) to prevent necrosis. Portal pressure should be lowered by combination of medical therapy +/- TIPSS. Patients with erosive oesophagitis / gastritis should receive a proton pump inhibitor. Mallory Weiss tears will typically resolve spontaneously Identifiable bleeding points should receive combination therapy of injection of adrenaline and either a thermal or mechanical treatment. All who have received intervention should receive a continuous infusion of a proton pump inhibitor (IV omeprazole for 72 hours) to reduce the re-bleeding rate. Patients with diffuse erosive gastritis who cannot be managed endoscopically and continue to bleed may require gastrectomy Bleeding ulcers that cannot be controlled endoscopically may require laparotomy and ulcer underruning Indications for surgery Patients > 60 years Continued bleeding despite endoscopic intervention Recurrent bleeding Known cardiovascular disease with poor response to hypotension Surgery Duodenal ulcer Laparotomy, duodenotomy and under running of the ulcer. If bleeding is brisk then the ulcer is almost always posteriorly sited and will have invaded the gastroduodenal artery. Large bites using 0 Vicryl are taken above and below the ulcer base to occlude the vessel. The duodenotomy should be longitudinal but closed transversely to avoid stenosis. For gastric ulcer Under-running of the bleeding site Partial gastrectomy-antral ulcer Partial gastrectomy or under running the ulcer- lesser curve ulcer (involving left gastric artery) Total gastrectomy if bleeding persists Summary of Acute Upper GI bleeding recommendations: The need for admission and timing of endoscopic intervention may be predicted by using the Blatchford score. This considers a patients Hb, serum urea, pulse rate and blood pressure. Those patients with a score of 0 are low risk, all others are considered high risk and require admission and endoscopy. The requirement for pre endoscopic proton pump inhibition is contentious. In the UK the National Institute of Clinical Excellence guidelines suggest the pre endoscopic PPI therapy is unnecessary. Whilst it is accepted that such treatment has no impact on mortality or morbidity a Cochrane review of this practice in 2007 did suggest that it reduced the stigmata of recent haemorrhage at endoscopy. As a result many will still administer PPI to patients prior to endoscopic intervention. Following endoscopy it is important to calculate the Rockall score for patients to determine their risk of rebleeding and mortality. A score of 3 or less is associated with a rebleeding rate of 4% and a very low risk of mortality and identifies a group of patients suitable for early discharge. References 1. http://www.sign.ac.uk/guidelines/fulltext/105/index.html 2. Joint Advisory Group on Endoscopy (JAG) Guidelines - http://www.thejag.org.uk 3. NICE Guideline: Management of acute upper GI bleeding. July 2012.

Answer 1835

The SMA leaves the aorta at L1. It passes under the neck of the pancreas prior to giving its first branch the inferior pancreatico-duodenal artery. Superior mesenteric artery Branches off aorta at L1 Supplies small bowel from duodenum (distal to ampulla of vater) through to mid transverse colon Takes more oblique angle from aorta and thus more likely to recieve emboli than coeliac axis Relations of superior mesenteric artery Superiorly Neck of pancreas Postero-inferiorly Third part of duodenum Uncinate process Posteriorly Left renal vein Right Superior mesenteric vein Branches of the superior mesenteric artery Inferior pancreatico-duodenal artery Jejunal and ileal arcades Ileo-colic artery Right colic artery Middle colic artery

Answer 1836

A combination of severe otalgia and facial nerve palsy in a diabetic should raise suspicion of malignant otitis externa. This is a condition caused by pseudomonas. It commences as otitis externa and then progresses to involve the temporal bone. Spread of the disease outside the external auditory canal occurs through the fissures of Santorini and the osseocartilaginous junction. Disorders affecting the ear Otitis externa Variant Cause Features Treatment Acute otitis externa Boil in external auditory meatus Acute pain on moving the pinna Conductive hearing loss if lesion is large When rupture occurs pus will flow from ear Ear packs may be used Topical antibiotics Operative debridement may be needed in severe cases Chronic otitis externa Chronic combined infection in the external auditory meatus usually combined staphylococcal and fungal infection Chronic discharge from affected ear, hearing loss and severe pain rare Cleansing of the external ear and treatment with antifungal and antibacterial ear drops Otitis media Variant Cause Features Treatment Acute suppurative otitis media Viral induced middle ear effusions secondary to eustacian tube dysfunction Most common in children and rare in adults May present with symptoms elsewhere (e.g. vomiting) in children Severe pain and sometimes fever May present with discharge if tympanic rupture occurs Antibiotics (usually amoxycillin) Chronic suppurative otitis media May occur with or without cholesteatoma Those without cholesteatoma have a perforation of the pars tensa Those with cholesteatoma have a perforation of the pars flaccida Those without cholesteatoma may complain of intermittent discharge (non offensive) Those with cholesteatoma have impaired hearing and foul smelling discharge Simple pars tensa perforations may be managed non operatively or a myringoplasty considered if symptoms troublesome. Pars flaccida perforations will usually require a modified radical mastoidectomy Otosclerosis Progressive conductive deafness Secondary to fixation of the stapes in the oval window Treatment is with stapedectomy and insertion of a prosthesis Acoustic neuroma Symptoms of gradually progressive unilateral perceptive deafness and tinnitus Involvement of the vestibular nerve may cause vertigo Extension to involve the facial nerve may cause weakness and then paralysis. Pre auricular sinus Common congenital condition in which an epithelial defect forms around the external ear Small sinuses require no treatment Deeper sinuses may become blocked and develop episodes of infection, they may be closely related to the facial nerve and are challenging to excise

Answer 1837

The majority of patients with colonic bleeding will be found to have bleeding secondary to diverticular disease. Of note, inflammation (i.e. diverticulitis) is not seen in such cases. Around 70% will stop bleeding spontaneously. Anti platelet and anti coagulants are sometimes complicating factors and may make bleeding less likely to cease spontaneously. Ischaemic colitis often has more dominant colitis symptoms. Rectal bleeding Rectal bleeding is a common cause for patients to be referred to the surgical clinic. In the clinical history it is useful to try and localise the anatomical source of the blood. Bright red blood is usually of rectal anal canal origin, whilst dark red blood is more suggestive of a proximally sited bleeding source. Blood which has entered the GI tract from a gastro-duodenal source will typically resemble malaena due to the effects of the digestive enzymes on the blood itself. In the table below we give some typical bleeding scenarios together with physical examination findings and causation. Cause Type of bleeding Features in history Examination findings Fissure in ano Bright red rectal bleeding Painful bleeding that occurs post defecation in small volumes. Usually antecedent features of constipation Muco-epithelial defect usually in the midline posteriorly (anterior fissures more likely to be due to underlying disease) Haemorroids Bright red rectal bleeding Post defecation bleeding noted both on toilet paper and drips into pan. May be alteration of bowel habit and history of straining. No blood mixed with stool. No local pain. Normal colon and rectum. Proctoscopy may show internal haemorrhoids. Internal haemorrhoids are usually impalpable. Crohns disease Bright red or mixed blood Bleeding that is accompanied by other symptoms such as altered bowel habit, malaise, history of fissures (especially anterior) and abscesses. Perineal inspection may show fissures or fistulae. Proctoscopy may demonstrate indurated mucosa and possibly strictures. Skip lesions may be noted at colonoscopy. Ulcerative colitis Bright red bleeding often mixed with stool Diarrhoea, weight loss, nocturnal incontinence, passage of mucous PR. Proctitis is the most marked finding. Peri anal disease is usually absent. Colonoscopy will show continuous mucosal lesion. Rectal cancer Bright red blood mixed volumes Alteration of bowel habit. Tenesmus may be present. Symptoms of metastatic disease. Usually obvious mucosal abnormality. Lesion may be fixed or mobile depending upon disease extent. Surrounding mucosa often normal, although polyps may be present. Investigation All patients presenting with rectal bleeding require digital rectal examination and procto-sigmoidoscopy as a minimal baseline. Remember that haemorrhoids are typically impalpable and to attribute bleeding to these in the absence of accurate internal inspection is unsatisfactory. In young patients with no other concerning features in the history a carefully performed sigmoidoscopy that demonstrates clear haemorrhoidal disease may be sufficient. If clear views cannot be obtained then patients require bowel preparation with an enema and a flexible sigmoidscopy performed. In those presenting with features of altered bowel habit or suspicion of inflammatory bowel disease a colonoscopy is the best test. Patients with excessive pain who are suspected of having a fissure may require an examination under general or local anaesthesia. In young patients with external stigmata of fissure and a compatible history it is acceptable to treat medically and defer internal examination until the fissure is healed. If the fissure fails to heal then internal examination becomes necessary along the lines suggested above to exclude internal disease. Special tests In patients with a malignancy of the rectum the staging investigations comprise an MRI of the rectum to identify circumferential resection margin compromise and to identify mesorectal nodal disease. In addition to this CT scanning of the chest abdomen and pelvis is necessary to stage for more distant disease. Some centres will still stage the mesorectum with endo rectal ultrasound but this is becoming far less common. Patients with fissure in ano who are being considered for surgical sphincterotomy and are females who have an obstetric history should probably have ano rectal manometry testing performed together with endo anal ultrasound. As this service is not universally available it is not mandatory but in the absence of such information there are continence issues that may arise following sphincterotomy. Management Disease Management Fissure in ano GTN ointment 0.2% or diltiazem cream applied topically is the usual first line treatment. Botulinum toxin for those who fail to respond. Internal sphincterotomy for those who fail with botox, can be considered earlier in males. Haemorroids Lifestyle advice, for small internal haemorrhoids can consider injection sclerotherapy or rubber band ligation. For external haemorrhoids consider haemorrhoidectomy. Modern options include HALO procedure and stapled haemorrhoidectomy. Inflammatory bowel disease Medical management- although surgery may be needed for fistulating Crohns (setons). Rectal cancer Anterior resection or abdomino-perineal excision of the colon and rectum. Total mesorectal excision is now standard of care. Most resections below the peritoneal reflection will require defunctioning ileostomy. Most patients will require preoperative radiotherapy.

Answer 1838

Neonatal deterioration in premature babies is not infrequently due to intra ventricular haemorrhage. In extreme prematurity the prognosis can be very poor. Intra cranial haemorrhage Extradural haematoma Bleeding into the space between the dura mater and the skull. Often results from acceleration-deceleration trauma or a blow to the side of the head. The majority of extradural haematomas occur in the temporal region where skull fractures cause a rupture of the middle meningeal artery. Features Raised intracranial pressure Some patients may exhibit a lucid interval Subdural haematoma Bleeding into the outermost meningeal layer. Most commonly occur around the frontal and parietal lobes. May be either acute or chronic. Risk factors include old age and alcoholism. Slower onset of symptoms than a extradural haematoma. Intracerebral haematoma Usually hyperdense lesions on CT scanning. Arise in areas of traumatic contusion which fuse to become a haematoma. Areas of clot and fresh blood may co-exist on the same CT scan (Swirl sign). Large haematomas and those associated with mass effect should be evacuated. Subarachnoid haemorrhage Usually occurs spontaneously in the context of a ruptured cerebral aneurysm but may be seen in association with other injuries when a patient has sustained a traumatic brain injury Intraventricular haemorrhage Haemorrhage that occurs into the ventricular system of the brain. It is relatively rare in adult surgical practice and when it does occur, it is typically associated with severe head injuries. In premature neonates it may occur spontaneously. The blood may clot and occlude CSF flow, hydrocephalus may result. In neonatal practice the vast majority of IVH occur in the first 72 hours after birth, the aetiology is not well understood and it is suggested to occur as a result of birth trauma combined with cellular hypoxia, together with the delicate neonatal CNS.

Answer 1839

This is a Gritti - Stokes amputation. During a Gritti - Stokes operation the patella is conserved and swung posteriorly to cover the distal femoral surface. Amputations Amputations are indicated when the affected limb is one of the following: Dead non viable Deadly where it is posing a major threat to life Dead useless where it is viable but a prosthesis would be preferable Orthopaedic surgery Amputation is often undertaken as an option of last resort e.g. Limb salvage has failed and the limb is so non functional that mobility needs would be best met with prosthesis. Chronic fracture non union or significant limb shortening following trauma would fit into this category. Occasionally following major trauma a primary amputation is preferable. This would be the case in an open fracture with major distal neurovascular compromise and other more life threatening injuries are present. Vascular surgery The first two categories are the most prevalent. Diabetic foot sepsis is often a major cause of sepsis which can spread rapidly in the presence of established peripheral vascular disease. As a general rule the main issue in vascular surgery is to optimise vascular inflow prior to surgery. The more distal the planned amputation is to be, the more important this rule becomes. In other situations there has been something such as an embolic event that has not been revascularised in time. In this case the limb shows fixed mottling and an amputation will be needed. Types of amputations As the vast majority of commonly performed amputations affect the lower limbs these will be covered here. The main categories of amputations are: Pelvic disarticulation (hindquarter) Above knee amputation Gritti Stokes (through knee amputation) Below knee amputation (using either Skew or Burgess flaps) Syme's amputation (through ankle) Amputations of mid foot and digits Choosing a level of amputation depends on: The disease process being treated Desired functional outcome Co-morbidities of the patient Above knee amputations Quick to perform Heal reliably Patients regain their general health quickly For this benefit, a functional price has to be paid and many patients over the age of 70 will never walk on an above knee prosthesis. Above knee amputations use equal anterior-posterior flaps Below knee amputations Technically more challenging to perform Heal less reliably than their above knee counterparts. However, many more patients are able to walk using a below knee prosthesis. In below knee amputations the two main flaps are Skew flaps or the Burgess long posterior flap. Skew flaps result in a less bulky limb that is easier to attach a prosthesis to. It is worth remembering that whilst it may be technically feasible to offer a below knee amputation there may be circumstances where an above knee option is preferable. For example, in fixed flexion deformities of the lower limb, little functional benefit would be gained from below knee amputation surgery.

Answer 1840

The inferior nasal concha is the most inferior and anterior and would be seen first. The choana is located more posteriorly. The torus tubaris is the tubal elevation and is an elevation of the cartilage and mucous membrane that covers the Eustachian tube. Nasal cavity There are two nasal cavities separated by the median nasal septum. This structure consists of septal cartilage and two bony parts: the vomer and the perpendicular plate of the ethmoid bone. Each cavity is approximately 5cm high and 7cm long, from the nares anteriorly to the choanae posteriorly. The lateral walls of each cavity are mainly made up of the maxilla. However, the lacrimal, ethmoid and palatine bones also contribute. The ethmoid gives rise to the two upper protrusions from the lateral walls, the superior and middle conchae. The inferior concha is a separate bone. Above the superior concha lies the sphenoethmoidal recess. The spaces inferior to conchae are the superior, middle and inferior meatus. The structures draining into each space are shown below: Sphenoethmoidal recess Sphenoidal sinus Superior meatus Posterior ethmoidal sinus Middle meatus Frontal sinus, maxillary sinus ,anterior and middle ethmoidal sinus Inferior meatus Nasolacrimal duct The main arterial supply to the septum and lateral walls is the sphenopalatine artery, a branch of the maxillary artery. The olfactory nerve conveys special sensation. Common sensation from the nasal mucosa is conveyed by the trigeminal nerve.

Answer 1841

Duct ectasia is common during the period of breast involution that occurs during the menopausal period. As the ducts shorten they may contain inspissated material. The discharge will often discharge from several ducts. Non malignant breast disease Duct ectasia Mammary duct ectasia may be seen in up to 25% of normal female breasts Patients usually present with nipple discharge, which may be from single or multiple ducts (usually present age >50 years) The discharge is often thick and green Duct ectasia is a normal variant of breast involution and is not the same condition as periductal mastitis Mass develops behind nipple Periductal mastitis Present at younger age than duct ectasia May present with features of inflammation, abscess or mammary duct fistula Strongly associated with smoking Usually treated with antibiotics, abscess will require drainage Mass develops around nipple Intraductal papilloma Growth of papilloma in a single duct Usually presents with clear or blood stained discharge originating from a single duct No increase in risk of malignancy Breast abscess Lactational mastitis is common Infection is usually with Staphylococcus aureus On examination there is usually a tender fluctuant mass Treatment is with antibiotics and ultrasound guided aspiration Overlying skin necrosis is an indication for surgical debridement, which may be complicated by the development of a subsequent mammary duct fistula. Tuberculosis Rare in western countries, usually secondary TB Affects women later in child bearing period Chronic breast or axillary sinus is present in up to 50% cases Diagnosis is by biopsy culture and histology

Answer 1842

In children, a hydrocele is most commonly due to a persistent processus vaginalis. The swelling is intermittent and in most cases that are diagnosed in infancy the hydrocele resolves. Cases that persist beyond two years of age are best managed surgically and the surgical approach is usually made via the inguinal canal where the patent processus is identified and ligated. Scrotal swelling Differential diagnosis Inguinal hernia If inguinoscrotal swelling; cannot 'get above it' on examination Cough impulse may be present May be reducible Testicular tumours Often discrete testicular nodule (may have associated hydrocele) Symptoms of metastatic disease may be present USS scrotum and serum AFP and β HCG required Acute epididymo-orchitis Often history of dysuria and urethral discharge Swelling may be tender and eased by elevating testis Most cases due to Chlamydia Infections with other gram negative organisms may be associated with underlying structural abnormality Epididymal cysts Single or multiple cysts May contain clear or opalescent fluid (spermatoceles) Usually occur over 40 years of age Painless Lie above and behind testis It is usually possible to 'get above the lump' on examination Hydrocele Non painful, soft fluctuant swelling Often possible to 'get above it' on examination Usually contain clear fluid Will often transilluminate May be presenting feature of testicular cancer in young men Testicular torsion Severe, sudden onset testicular pain Risk factors include abnormal testicular lie Typically affects adolescents and young males On examination testis is tender and pain not eased by elevation Urgent surgery is indicated, the contra lateral testis should also be fixed Varicocele Varicosities of the pampiniform plexus Typically occur on left (because testicular vein drains into renal vein) May be presenting feature of renal cell carcinoma Affected testis may be smaller and bilateral varicoceles may affect fertility Management Testicular malignancy is always treated with orchidectomy via an inguinal approach. This allows high ligation of the testicular vessels and avoids exposure of another lymphatic field to the tumour. Torsion is commonest in young teenagers and the history in older children can be difficult to elicit. Intermittent torsion is a recognised problem. The treatment is prompt surgical exploration and testicular fixation. This can be achieved using sutures or by placement of the testis in a Dartos pouch. Varicoceles are usually managed conservatively. If there are concerns about testicular function of infertility then surgery or radiological management can be considered. Epididymal cysts can be excised using a scrotal approach Hydroceles are managed differently in children where the underlying pathology is a patent processus vaginalis and therefore an inguinal approach is used in children so that the processus can be ligated. In adults a scrotal approach is preferred and the hydrocele sac excised or plicated.

Answer 1843

EBV infection is the classic cause of sudden spontaneous splenic rupture. Of the many conditions linked to COVID 19, splenic rupture is not one of them. Disorders affecting the spleen One of the commonest conditions to affect the spleen is traumatic rupture and this is addressed elsewhere. Splenomegaly Enlargement of the spleen can commonly accompany a variety of haematological disorders. Of these, chronic conditions such as haemolytic anaemia and chronic leukaemia are often associated with splenomegaly. More acute haematological conditions tend not to cause massive splenic enlargement. Infections with parasites (such as malaria) and viruses such as Epstein Barr virus can cause splenomegaly and this one condition that is associated with sudden spontaneous splenic rupture. Portal hypertension can result in splenomegaly and the finding of an enlarged spleen on abdominal examination should prompt a search for the other stigmata of chronic liver disease. Splenic atrophy This typically occurs as a result of conditions that impair the blood flow to the spleen. Division of some of the major vessels can cause shrinkage of the spleen and this is commonly seen when splenic artery aneurysms are coiled for example.

Answer 1844

The portal vein transports 70% of the blood supply to the liver, while the hepatic artery provides 30%. The portal vein contains the products of digestion. The arterial and venous blood is dispersed by sinusoids to the central veins of the liver lobules; these drain into the hepatic veins and then into the IVC. The caudate lobe drains directly into the IVC rather than into other hepatic veins. Liver Structure of the liver Right lobe Supplied by right hepatic artery Contains Couinaud segments V to VIII (-/+Sg I) Left lobe Supplied by the left hepatic artery Contains Couinaud segments II to IV (+/- Sg1) Quadrate lobe Part of the right lobe anatomically, functionally is part of the left Couinaud segment IV Porta hepatis lies behind On the right lies the gallbladder fossa On the left lies the fossa for the umbilical vein Caudate lobe Supplied by both right and left hepatic arteries Couinaud segment I Lies superior to the porta hepatis Anterior and medial to the inferior vena cava Bile from the caudate lobe drains into both right and left hepatic ducts Detailed knowledge of Couinaud segments is not required for MRCS Between the liver lobules are portal canals which contain the portal triad: Hepatic Artery, Portal Vein, tributary of Bile Duct. Relations of the liver Anterior Postero inferiorly Diaphragm Oesophagus Xiphoid process Stomach Duodenum Hepatic flexure of colon Right kidney Gallbladder Inferior vena cava Porta hepatis Location Postero inferior surface, it joins nearly at right angles with the left sagittal fossa, and separates the caudate lobe behind from the quadrate lobe in front Transmits Common hepatic duct Hepatic artery Portal vein Sympathetic and parasympathetic nerve fibres Lymphatic drainage of the liver (and nodes) Ligaments Falciform ligament 2 layer fold peritoneum from the umbilicus to anterior liver surface Contains ligamentum teres (remnant umbilical vein) On superior liver surface it splits into the coronary and left triangular ligaments Ligamentum teres Joins the left branch of the portal vein in the porta hepatis Ligamentum venosum Remnant of ductus venosus Arterial supply Hepatic artery Venous Hepatic veins Portal vein Nervous supply Sympathetic and parasympathetic trunks of coeliac plexus

Answer 1845

Calcitonin has the opposite effect of PTH and is released from the thyroid gland. Calcium homeostasis Calcium ions are linked to a wide range of physiological processes. The largest store of bodily calcium is contained within the skeleton. Calcium levels are primarily controlled by parathyroid hormone, vitamin D and calcitonin. Hormonal regulation of calcium Hormone Actions Parathyroid hormone (PTH) Increase calcium levels and decrease phosphate levels Increases bone resorption Immediate action on osteoblasts to increase ca2+ in extracellular fluid Osteoblasts produce a protein signaling molecule that activate osteoclasts which cause bone resorption Increases renal tubular reabsorption of calcium Increases synthesis of 1,25(OH)2D (active form of vitamin D) in the kidney which increases bowel absorption of Ca2+ Decreases renal phosphate reabsorption 1,25-dihydroxycholecalciferol (the active form of vitamin D) Increases plasma calcium and plasma phosphate Increases renal tubular reabsorption and gut absorption of calcium Increases osteoclastic activity at high levels and osteoblasts at low levels Increases renal phosphate reabsorption Calcitonin Secreted by C cells of thyroid Inhibits intestinal calcium absorption Inhibits osteoclast activity Inhibits renal tubular absorption of calcium Both growth hormone and thyroxine also play a small role in calcium metabolism.

Answer 1846

Stag-horn calculi are composed of struvite and form in alkaline urine (ammonia producing bacteria therefore predispose) Renal stones on x-ray cystine stones: semi-opaque urate + xanthine stones: radio-lucent Renal stones: imaging The table below summarises the appearance of different types of renal stone on x-ray Type Frequency Radiograph appearance Calcium oxalate 40% Opaque Mixed calcium oxalate/phosphate stones 25% Opaque Triple phosphate stones* 10% Opaque Calcium phosphate 10% Opaque Urate stones 5-10% Radio-lucent Cystine stones 1% Semi-opaque, 'ground-glass' appearance Xanthine stones <1% Radio-lucent *stag-horn calculi involve the renal pelvis and extend into at least 2 calyces. They develop in alkaline urine and are composed of struvite (ammonium magnesium phosphate, triple phosphate). Ureaplasma urealyticum and Proteus infections predispose to their formation

Answer 1847

The vast majority of small adrenal lesions are incidental, benign and non functioning adenomas. Apart from minimal workup, no further investigation is needed. Of note, if there are concerns about malignancy, the only surgical option is adrenalectomy. Adrenal lesions- Incidental Incidentaloma of the adrenal glands have become increasingly common as CT scanning of the abdomen is widely undertaken. Prevalences range from 1.5-9% in autopsy studies. Overall, 75% will be non functioning adenomas. Investigation to exclude a functioning lesion is as below: Investigation Morning and midnight plasma cortisol measurements Dexamethasone suppression test 24 hour urinary cortisol excretion 24 hour urinary excretion of catecholamines Serum potassium, aldosterone and renin levels Management The risk of malignancy is related to the size of the lesion and 25% of all masses greater than 4cm will be malignant. Such lesions should usually be excised. Where a lesion is a suspected metastatic deposit a biopsy may be considered.

Answer 1848

Adductor longus forms the medial boundary of the femoral triangle (see below). Femoral triangle anatomy Boundaries Superiorly Inguinal ligament Laterally Sartorius Medially Adductor longus Floor Iliopsoas, adductor longus and pectineus Roof Fascia lata and Superficial fascia Superficial inguinal lymph nodes (palpable below the inguinal ligament) Long saphenous vein This is displayed as an annotated cadaveric image below, the terms FV, FA, FN refer to the femoral artery, vein and nerve respectively and the SFJ is the saphenofemoral junction. Contents Femoral vein (medial to lateral) Femoral artery-pulse palpated at the mid inguinal point Femoral nerve Deep and superficial inguinal lymph nodes Lateral cutaneous nerve Great saphenous vein Femoral branch of the genitofemoral nerve

Answer 1849

Unilateral swelling and fever is usually indicative of quinsy. Surgical drainage usually produces prompt resolution of symptoms. Acute tonsillitis Characterised by pharyngitis, fever, malaise and lymphadenopathy. Over half of all cases are bacterial with Streptococcus pyogenes the most common organism The tonsils are typically oedematous and yellow or white pustules may be present Infectious mononucleosis may mimic the condition. Treatment with penicillin type antibiotics is indicated for bacterial tonsillitis. Bacterial tonsillitis may result in local abscess formation (quinsy)

Answer 1850

Necrotising enterocolitis often has a delayed presentation and affected infants will typically pass bloody stools. Plain films may show air in the intestinal wall (Pneumatosis). Bilious vomiting in neonates Causes of intestinal obstruction with bilious vomiting in neonates Disorder Incidence and causation Age at presentation Diagnosis Treatment Duodenal atresia 1 in 5000 (higher in Downs syndrome) Few hours after birth AXR shows 'double bubble sign, contrast study may confirm Duodenoduodenostomy Malrotation with volvulus Usually cause by incomplete rotation during embryogenesis Usually 3-7 days after birth, volvulus with compromised circulation may result in peritoneal signs and haemodynamic instability Upper GI contrast study may show DJ flexure is more medially placed, USS may show abnormal orientation of SMA and SMV Ladd's procedure Jejunal/ ileal atresia Usually caused by vascular insufficiency in utero, usually 1 in 3000 Usually within 24 hours of birth AXR will show air-fluid levels Laparotomy with primary resection and anastomosis Meconium ileus Occurs in between 15 and20% of those babies with cystic fibrosis, otherwise 1 in 5000 Typically in first 24-48 hours of life with abdominal distension and bilious vomiting Air - fluid levels on AXR, sweat test to confirm cystic fibrosis Surgical decompression, serosal damage may require segmental resection Necrotising enterocolitis Up to 2.4 per 1000 births, risks increased in prematurity and inter-current illness Usually second week of life Dilated bowel loops on AXR, pneumatosis and portal venous air Conservative and supportive for non perforated cases, laparotomy and resection in cases of perforation of ongoing clinical deterioration

Answer 1851

Ghon focus is primary infection Ghon complex is primary infection and regional nodal involvement Tuberculosis pathology Is a form of primary chronic inflammation, caused by the inability of macrophages to kill the Mycobacterium tuberculosis. The macrophages often migrate to regional lymph nodes, the lung lesion plus affected lymph nodes is referred to as a Ghon complex. This leads to the formation of a granuloma which is a collection of epithelioid histiocytes. There is the presence of caseous necrosis in the centre. The inflammatory response is mediated by a type 4 hypersensitivity reaction. In healthy individuals the disease may be contained, in the immunocompromised disseminated (miliary TB) may occur. Diagnosis Waxy membrane of mycobacteria prevents binding with normal stains. Ziehl - Neelsen staining is typically used. Culture based methods take far longer. Image showing acid- alcohol fast mycobacteria stained using the Ziehl- Neelsen method

Answer 1852

Lymphatic drainage of the vagina The lymph vessels from the superior aspect of the vagina join the internal and external iliac nodes, those from the inferior aspect of the vagina drain to the superficial inguinal nodes.

Answer 1853

Its an anterior pituitary lesion and that is the reason thyroxine secretion is affected. ADH is released by the posterior pituitary. Pituitary Gland The pituitary gland is located within the sella turcica within the sphenoid bone in the middle cranial fossa. It is covered by a dural fold and weighs around 0.5g. It is attached to the hypothalamus by the infundibulum. The anterior pituitary receives hormonal stimuli from the hypothalamus by way of the hypothalamo-pituitary portal system. It develops from a depression in the wall of the pharynx (Rathkes pouch). Anterior pituitary hormones Growth hormone Thyroid stimulating hormone ACTH Prolactin LH and FSH Melanocyte releasing hormone Posterior pituitary hormones Oxytocin Anti diuretic hormone

Answer 1854

Alagille syndrome autosomal dominant disorder characterised by presence of paucity of bile ducts and cardiac defects. Only the embryonic form of biliary atresia is associated with cardiac and other embryological defects. Biliary atresia usually presents with obstructed jaundice. A Kasai procedure is best performed in the first 8 weeks of life. If a Kasai procedure is successful most patients will not require liver transplantation. 45% of patients post Kasai procedure will require transplantation. However, overall survival following a successful Kasai procedure is 80%. Biliary atresia 1 in 17000 affected Biliary tree lumen is obliterated by an inflammatory cholangiopathy causing progressive liver damage Clinical features Infant well in 1st few weeks of life No family history of liver disease Jaundice in infants > 14 days in term infants (>21 days in pre term infants) Pale stool, yellow urine (colourless in babies) Associated with cardiac malformations, polysplenia, situs inversus Investigation Conjugated bilirubin (prolonged physiological jaundice or breast milk jaundice will cause a rise in unconjugated bilirubin, whereas those with obstructive liver disease will have a rise in conjugated bilirubin) Ultrasound of the liver (excludes extrahepatic causes, in biliary atresia infant may have tiny or invisible gallbladder) Hepato-iminodiacetic acid radionuclide scan (good uptake but no excretion usually seen) Management Early recognition is important to prevent liver transplantation. Nutritional support. Roux-en-Y portojejunostomy (Kasai procedure). If Kasai procedure fails or late recognition, a liver transplant becomes the only option.

Answer 1855

Ketamine does not affect healing. All the other situations in the list carry a strong association with poor healing and risk of dehisence. Abdominal wound dehiscence - This is a significant problem facing all surgeons who undertake abdominal surgery on a regular basis. Traditionally, it is said to occur when all layers of an abdominal mass closure fail and the viscera protrude externally (associated with 30% mortality). It can be subdivided into superficial, in which the skin wound alone fails and complete, implying failure of all layers. Factors which increase the risk are: * Malnutrition * Vitamin deficiencies * Jaundice * Steroid use * Major wound contamination (e.g. faecal peritonitis) * Poor surgical technique (Mass closure technique is the preferred method-Jenkins Rule) When sudden full dehiscence occurs the management is as follows: * Analgesia * Intravenous fluids * Intravenous broad spectrum antibiotics * Coverage of the wound with saline impregnated gauze (on the ward) * Arrangements made for a return to theatre Surgical strategy Correct the underlying cause (e.g. TPN or NG feed if malnourished) Determine the most appropriate strategy for managing the wound Options Resuturing of the wound This may be an option if the wound edges are healthy and there is enough tissue for sufficient coverage. Deep tension sutures are traditionally used for this purpose. Application of a wound manager This is a clear dressing with removable front. Particularly suitable when some granulation tissue is present over the viscera or where there is a high output bowel fistula present in the dehisced wound. Application of a 'Bogota bag' This is a clear plastic bag that is cut and sutured to the wound edges and is only a temporary measure to be adopted when the wound cannot be closed and will necessitate a return to theatre for definitive management. Application of a VAC dressing system These can be safely used BUT ONLY if the correct layer is interposed between the suction device and the bowel. Failure to adhere to this absolute rule will almost invariably result in the development of multiple bowel fistulae and create an extremely difficult management problem.

Answer 1856

Achlorhydria would make the formation of duodenal ulcers unlikely. Note the question states 'least likely'. Due to the loss of gastric acid a duodenal ulcer is unlikely. Note that gastric polyps may form (see below). Gastritis Type of gastritis Features Type A Autoimmune Circulating antibodies to parietal cells, causes reduction in cell mass and hypochlorhydria Loss of parietal cells = loss of intrinsic factor = B12 malabsorption Absence of antral involvement Hypochlorhydria causes elevated gastrin levels- stimulating enterochromaffin cells and adenomas may form Type B Antral gastritis Associated with infection with helicobacter pylori infection Intestinal metaplasia may occur in stomach and require surveillance endoscopy Peptic ulceration may occur Reflux gastritis Bile refluxes into stomach, either post surgical or due to failure of pyloric function Histologically, evidence of chronic inflammation, and foveolar hyperplasia May respond to therapy with prokinetics Erosive gastritis Agents disrupt the gastric mucosal barrier Most commonly due to NSAIDs and alcohol With NSAIDs the effects occur secondary to COX 1 inhibition Stress ulceration This occurs as a result of mucosal ischaemia during hypotension or hypovolaemia The stomach is the most sensitive organ in the GI tract to ischaemia following hypovolaemia Diffuse ulceration may occur Prophylaxis with acid lowering therapy and sucralfate may minimise complications Menetriers disease Gross hypertrophy of the gastric mucosal folds, excessive mucous production and hypochlorhydria Pre malignant condition References Whiting J et al. The long term results of endoscopic surveillance of premalignant gastric lesions. Gut 2002; 50 :378381. Dixon M et al. Reflux gastritis: distinct histopathological entity?J Clin Pathol 1986; 39 : 524-530.

Answer 1857

The immediate treatment of hypercalcaemia involves intravenous fluid resuscitation. This may be complemented with the use of bisphosphonates and sometimes diuretics. However, fluids are administered first and because this question asks what the most appropriate initial treatment is, intravenous fluids are the most appropriate answer. Normal saline is usually preferred for this over dextrose containing solutions. Management of hypercalcaemia Free Ca is affected by pH (increased in acidosis) and plasma albumin concentration ECG changes include: Shortening of QTc interval Urgent management is indicated if: Calcium > 3.5 mmol/l Reduced consciousness Severe abdominal pain Pre renal failure Management: Airway Breathing Circulation Intravenous fluid resuscitation with 3-6L of 0.9% Normal saline in 24 hours Concurrent administration of calcitonin will also help lower calcium levels Medical therapy (usually if Corrected calcium >3.0mmol/l) Bisphosphonates Analogues of pryrophosphate Prevent osteoclast attachment to bone matrix and interfere with osteoclast activity Inhibit bone resorption. Agents Drug Side effects Notes IV Pamidronate pyrexia, leucopaenia Most potent agent IV Zoledronate response lasts 30 days Used for malignancy associated hypercalcaemia Calcitonin Quickest onset of action however short duration (tachyphylaxis) therefore only given with a second agent. Prednisolone May be given in hypercalcaemia related to sarcoidosis, myeloma or vitamin D intoxication.

Answer 1858

The passage of very loose and watery stools distinguishes cholera. Most gastroenteric infections do not produce such watery motions. Bacterial Gastroenteritis Causative organisms Features Campylobacter jejuni Most common cause of acute infective diarrhoea Spiral, gram negative rods Usually infects caecum and terminal ileum. Local lymphadenopathy is common May mimic appendicitis as it has marked right iliac fossa pain Reactive arthritis is seen in 1-2% of cases Shigella spp. Members of the enterobacteriaceae Gram negative bacilli Clinically causes dysentery Shigella soneii is the commonest infective organism (mild illness) Usually self limiting, ciprofloxacin may be required if individual is in a high risk group Salmonella spp Facultatively anaerobic, gram negative, enterobacteriaceae Infective dose varies according to subtype Salmonellosis: usually transmitted by infected meat (especially poultry) and eggs E. coli Enteropathogenic Enteroinvasive: dysentery, large bowel necrosis/ulcers Enterotoxigenic: small intestine, travelers diarrhoea Enterohaemorrhagic: 0157, cause a haemorrhagic colitis, haemolytic uraemic syndrome and thrombotic thrombocytopaenic purpura Yersinia enterocolitica Gram negative, coccobacilli Typically produces a protracted terminal ileitis that may mimic Crohns disease Differential diagnosis acute appendicitis May progress to septicaemia in susceptible individuals Usually sensitive to quinolone or tetracyclines Vibrio cholera Short, gram negative rods Transmitted by contaminated water, seafood Symptoms include sudden onset of effortless vomiting and profuse watery diarrhoea Correction of fluid and electrolyte losses are the mainstay of treatment Most cases will resolve, antibiotics are not generally indicated

Answer 1859

Viral illnesses can be associated with transient synovitis. The WCC should ideally be > 12 and the ESR > 40 to suggest septic arthritis. Paediatric orthopaedics Diagnosis Mode of presentation Treatment Radiology Developmental dysplasia of the hip Usually diagnosed in infancy by screening tests. May be bilateral, when disease is unilateral there may be leg length inequality. As disease progresses child may limp and then early onset arthritis. More common in extended breech babies. Splints and harnesses or traction. In later years osteotomy and hip realignment procedures may be needed. In arthritis a joint replacement may be needed. However, this is best deferred if possible as it will almost certainly require revision Initially no obvious change on plain films and USS gives best resolution until 3 months of age. On plain films Shentons line should form a smooth arc Perthes Disease Hip pain (may be referred to the knee) usually occurring between 5 and 12 years of age. Bilateral disease in 20%. Remove pressure from joint to allow normal development. Physiotherapy. Usually self-limiting if diagnosed and treated promptly. X-rays will show flattened femoral head. Eventually in untreated cases the femoral head will fragment. Slipped upper femoral epiphysis Typically seen in obese male adolescents. Pain is often referred to the knee. Limitation to internal rotation is usually seen. Knee pain is usually present 2 months prior to hip slipping. Bilateral in 20%. Bed rest and non-weight bearing. Aim to avoid avascular necrosis. If severe slippage or risk of it occurring then percutaneous pinning of the hip may be required. X-rays will show the femoral head displaced and falling inferolaterally (like a melting ice cream cone) The Southwick angle gives indication of disease severity

Answer 1860

Pyoderma gangrenosum may occur in Crohns disease. Cutaneous involvement of granulomas a.k.a metastatic crohns is recognized but very rare and much less likely and therefore not the correct answer. Skin Diseases Skin lesions may be referred for surgical assessment, but more commonly will come via a dermatologist for definitive surgical management. Skin malignancies include basal cell carcinoma, squamous cell carcinoma and malignant melanoma. Basal Cell Carcinoma Most common form of skin cancer. Commonly occur on sun exposed sites apart from the ear. Sub types include nodular, morphoeic, superficial and pigmented. Typically slow growing with low metastatic potential. Standard surgical excision, topical chemotherapy and radiotherapy are all successful. As a minimum a diagnostic punch biopsy should be taken if treatment other than standard surgical excision is planned. Squamous Cell Carcinoma Again related to sun exposure. May arise in pre - existing solar keratoses. May metastasize if left. Immunosupression (e.g. following transplant), increases risk. Wide local excision is the treatment of choice and where a diagnostic excision biopsy has demonstrated SCC, repeat surgery to gain adequate margins may be required. Malignant Melanoma The main diagnostic features (major criteria): Change in size Change in shape Change in colour Secondary features (minor criteria) Diameter >6mm Inflammation Oozing or bleeding Altered sensation Treatment Suspicious lesions should undergo excision biopsy. The lesion should be removed completely as incision biopsy can make subsequent histopathological assessment difficult. Once the diagnosis is confirmed the pathology report should be reviewed to determine whether further re-excision of margins is required (see below): Margins of excision-Related to Breslow thickness Lesions 0-1mm thick 1cm Lesions 1-2mm thick 1- 2cm (Depending upon site and pathological features) Lesions 2-4mm thick 2-3 cm (Depending upon site and pathological features) Lesions >4 mm thick 3cm Marsden J et al. Revised UK guidelines for management of Melanoma. Br J Dermatol 2010 163:238-256. Further treatments such as sentinel lymph node mapping, isolated limb perfusion and block dissection of regional lymph node groups should be selectively applied. Kaposi Sarcoma Tumour of vascular and lymphatic endothelium. Purple cutaneous nodules. Associated with immuno supression. Classical form affects elderly males and is slow growing. Immunosupression form is much more aggressive and tends to affect those with HIV related disease. Non malignant skin disease Dermatitis Herpetiformis Chronic itchy clusters of blisters. Linked to underlying gluten enteropathy (coeliac disease). Dermatofibroma Benign lesion. Firm elevated nodules. Usually history of trauma. Lesion consists of histiocytes, blood vessels and fibrotic changes. Pyogenic granuloma Overgrowth of blood vessels. Red nodules. Usually follow trauma. May mimic amelanotic melanoma. Acanthosis nigricans Brown to black, poorly defined, velvety hyperpigmentation of the skin. Usually found in body folds such as the posterior and lateral folds of the neck, the axilla, groin, umbilicus, forehead, and other areas. The most common cause of acanthosis nigricans is insulin resistance, which leads to increased circulating insulin levels. Insulin spillover into the skin results in its abnormal increase in growth (hyperplasia of the skin). In the context of a malignant disease, acanthosis nigricans is a paraneoplastic syndrome and is then commonly referred to as acanthosis nigricans maligna. Involvement of mucous membranes is rare and suggests a coexisting malignant condition.

Answer 1861

The trigeminal nerve is the major sensory nerve to the face except over the angle of the jaw. The angle of the jaw is innervated by the greater auricular nerve. Trigeminal nerve The trigeminal nerve is the main sensory nerve of the head. In addition to its major sensory role, it also innervates the muscles of mastication. Distribution of the trigeminal nerve Sensory Scalp Face Oral cavity (and teeth) Nose and sinuses Dura mater Motor Muscles of mastication Mylohyoid Anterior belly of digastric Tensor tympani Tensor palati Autonomic connections (ganglia) Ciliary Sphenopalatine Otic Submandibular Path Originates at the pons Sensory root forms the large, crescentic trigeminal ganglion within Meckel's cave, and contains the cell bodies of incoming sensory nerve fibres. Here the 3 branches exit. The motor root cell bodies are in the pons and the motor fibres are distributed via the mandibular nerve. The motor root is not part of the trigeminal ganglion. Branches of the trigeminal nerve Ophthalmic nerve Sensory only Maxillary nerve Sensory only Mandibular nerve Sensory and motor Sensory Ophthalmic Exits skull via the superior orbital fissure Sensation of: scalp and forehead, the upper eyelid, the conjunctiva and cornea of the eye, the nose (including the tip of the nose, except alae nasi), the nasal mucosa, the frontal sinuses, and parts of the meninges (the dura and blood vessels). Maxillary nerve Exit skull via the foramen rotundum Sensation: lower eyelid and cheek, the nares and upper lip, the upper teeth and gums, the nasal mucosa, the palate and roof of the pharynx, the maxillary, ethmoid and sphenoid sinuses, and parts of the meninges. Mandibular nerve Exit skull via the foramen ovale Sensation: lower lip, the lower teeth and gums, the chin and jaw (except the angle of the jaw), parts of the external ear, and parts of the meninges. Motor Distributed via the mandibular nerve. The following muscles of mastication are innervated: Masseter Temporalis Medial pterygoid Lateral pterygoid Other muscles innervated include: Tensor veli palatini Mylohyoid Anterior belly of digastric Tensor tympani

Answer 1862

The deep external pudendal artery runs under the long saphenous vein close to its origin and may be injured. It is at greatest risk of injury during the flush ligation of the saphenofemoral junction. Provided an injury is identified and vessel ligated, injury is seldom associated with any serious adverse sequelae. Saphenous vein Long saphenous vein This vein may be harvested for bypass surgery, or removed as treatment for varicose veins with saphenofemoral junction incompetence. Originates at the 1st digit where the dorsal vein merges with the dorsal venous arch of the foot Passes anterior to the medial malleolus and runs up the medial side of the leg At the knee, it runs over the posterior border of the medial epicondyle of the femur bone Then passes laterally to lie on the anterior surface of the thigh before entering an opening in the fascia lata called the saphenous opening It joins with the femoral vein in the region of the femoral triangle at the saphenofemoral junction Tributaries Medial marginal Superficial epigastric Superficial iliac circumflex Superficial external pudendal veins Short saphenous vein Originates at the 5th digit where the dorsal vein merges with the dorsal venous arch of the foot, which attaches to the great saphenous vein. It passes around the lateral aspect of the foot (inferior and posterior to the lateral malleolus) and runs along the posterior aspect of the leg (with the sural nerve) Passes between the heads of the gastrocnemius muscle, and drains into the popliteal vein, approximately at or above the level of the knee joint.

Answer 1863

Hypospadias most commonly occurs as an isolated disorder. Associated urological abnormalities may be seen in up to 40% of infants, of these cryptorchidism is the most frequent (10%). Hypospadias The urethral meatus opens on the ventral surface of the penis. There is also a ventral deficiency of the foreskin. The urethral meatus may open more proximally in the more severe variants. However, 75% of the openings are distally located. The incidence is 1 in 300 male births. Features include: Absent frenular artery Ventrally opened glans Skin tethering to hypoplastic urethra Splayed columns of spongiosum tissue distal to the meatus Deficiency of the foreskin ventrally Management: No routine cultural circumcisions Urethroplasty Penile reconstruction The foreskin is often utilised in the reconstructive process. In boys with very distal disease no treatment may be needed.

Answer 1864

Hassall's corpuscles are the concentric ring of epithelial cells seen in the medulla of the thymus. Thymus The thymus develops from the third and fourth pharyngeal pouches. It descends to lie in the anterior superior mediastinum. It is encapsulated and is subdivided into lobules, these consist of a cortex and a medulla. The cortex is composed of tightly packed lymphocytes, the medulla consists largely of epithelial cells. The medullary epithelial cells are concentrically arranged and may surround a keratinised centre, known as Hassall's corpuscles. The inferior parathyroid glands also develop from the third pharyngeal pouch and may also be located with the thymus gland. Its arterial supply is from the internal mammary artery or pericardiophrenic arteries. Venous drainage is to the left brachiocephalic vein.

Answer 1865

This sensory deficit pattern is most consistent with ulnar nerve injury. Ulnar nerve Origin C8, T1 Supplies (no muscles in the upper arm) Flexor carpi ulnaris Flexor digitorum profundus Flexor digiti minimi Abductor digiti minimi Opponens digiti minimi Adductor pollicis Interossei muscle Third and fourth lumbricals Palmaris brevis Path Posteromedial aspect of upper arm to flexor compartment of forearm, then along the ulnar. Passes beneath the flexor carpi ulnaris muscle, then superficially over the flexor retinaculum into the palm of the hand. Branches Branch Supplies Muscular branch Flexor carpi ulnaris Medial half of the flexor digitorum profundus Palmar cutaneous branch (Arises near the middle of the forearm) Skin on the medial part of the palm Dorsal cutaneous branch Dorsal surface of the medial part of the hand Superficial branch Cutaneous fibres to the anterior surfaces of the medial one and one-half digits Deep branch Hypothenar muscles All the interosseous muscles Third and fourth lumbricals Adductor pollicis Medial head of the flexor pollicis brevis Effects of injury Damage at the wrist Wasting and paralysis of intrinsic hand muscles (claw hand) Wasting and paralysis of hypothenar muscles Loss of sensation medial 1 and half fingers Damage at the elbow Radial deviation of the wrist Clawing less in 4th and 5th digits

Answer 1866

This lady has thyrotoxicosis (low TSH) and a hot solitary nodule indicating a toxic adenoma. Thyroid cancer rarely causes thyrotoxicosis or hot nodules. Hyperthyroidism Causes of hyperthyroidism include: Diffuse toxic goitre (Graves Disease) Toxic nodular goitre Toxic nodule Rare causes Graves disease Graves disease is characterised by a diffuse vascular goitre that appears at the same time as the clinical manifestations of hyperthyroidism. It is commonest in younger females and may be associated with eye signs. Thyrotoxic symptoms will predominate. Up to 50% of patients will have a familial history of autoimmune disorders. The glandular hypertrophy and hyperplasia occur as a result of the thyroid stimulating effects of the TSH receptor antibodies. Toxic nodular goitre In this disorder the goitre is present for a long period of time prior to the development of clinical symptoms. In most goitres the nodules are inactive and in some cases it is the internodular tissue that is responsible for the hyperthyroidism. Toxic nodule Overactive, autonomously functioning nodule. It may occur as part of generalised nodularity or be a true toxic adenoma. The TSH levels are usually low as the autonomously functioning thyroid tissue will exert a negative feedback effect. Signs and symptoms Symptoms Signs Lethargy Tachycardia Emotionally labile Agitation Heat intolerance Hot, moist palms Weight loss Exopthalmos Excessive appetite Thyroid goitre and bruit Palpitations Lid lag/retraction Diagnosis The most sensitive test for diagnosing hyperthyroidism is plasma T3 (which is raised). Note in hypothyroidism the plasma T4 and TSH are the most sensitive tests. A TSH level of <0.5U/L suggests hyperthyroidism. TSH receptor antibodies may be tested for in the diagnosis of Graves. Treatment First line treatment for Graves disease is usually medical and the block and replace regime is the favored option. Carbimazole is administered at higher doses and thyroxine is administered orally. Patients are maintained on this regime for between 6 and 12 months. Attempts are then made to wean off medication. Where relapse then occurs the options are between ongoing medical therapy, radioiodine or surgery.

Answer 1867

Mid inguinal point= surface marking for femoral artery Mid point of the inguinal ligament = surface marking for deep inguinal ring. Iliac arteries The common iliac arteries are terminal branches of the abdominal aorta. They begin opposite the middle body of the fourth lumbar vertebra. The superior hypogastric plexus lies anterior to the proximal end and more distally, it is crossed by the ureter. The last two lumbar vertebral bodies, and intervening disc, the sympathetic trunk and the medial part of psoas major lie behind each artery. They are separated from the right artery by the beginning of the inferior vena cava. The only branches of the common iliac arteries are the internal and external iliac arteries. Internal iliac artery Anteromedially, each internal iliac artery is covered by peritoneum, beneath which the ureter descends on the anterior surface of each artery. On the left, the vessel is overlapped by the sigmoid colon and, on the right, the terminal ileum overlies it. Posteriorly, the internal iliac vein and commencement of the common iliac vein are closely related to the artery. The posterior division of the internal iliac artery has parietal branches and the anterior division has both parietal and visceral branches. Branches of the posterior division of the internal iliac Lateral sacral, superior gluteal, iliolumbar artery. Branches of the anterior division of the internal iliac artery Obturator artery, internal pudendal artery, inferior gluteal, inferior vesical artery, artery the ductus deferens, middle rectal, vaginal artery, uterine artery. External iliac artery The external iliac artery extends from a point opposite the sacroiliac joint at the level of the lumbosacral disc to the midinguinal point behind the inguinal ligament, midway between the anterior superior iliac spine and the pubic symphysis.

Answer 1868

Renal plasma flow = (amount of PAH in urine per unit time) / (difference in PAH concentration in the renal artery or vein) Normal value = 660ml/min Renal Physiology Overview Each nephron is supplied with blood from an afferent arteriole that opens onto the glomerular capillary bed. Blood then flows to an efferent arteriole, supplying the peritubular capillaries and medullary vasa recta. The kidney receives up to 25% of resting cardiac output. Control of blood flow The kidney is able to autoregulate its blood flow between systolic pressures of 80- 180mmHg so there is little variation in renal blood flow. This is achieved by myogenic control of arteriolar tone, both sympathetic input and hormonal signals (e.g. renin) are responsible. Glomerular structure and function Blood inside the glomerulus has considerable hydrostatic pressure. The basement membrane has pores that will allow free diffusion of smaller solutes, larger negatively charged molecules such as albumin are unable to cross. The glomerular filtration rate (GFR) is equal to the concentration of a solute in the urine, times the volume of urine produced per minute, divided by the plasma concentration (assuming that the solute is freely diffused e.g. inulin). In clinical practice creatinine is used because it is subjected to very little proximal tubular secretion. Although subject to variability, the typical GFR is 125ml per minute. Glomerular filtration rate = Total volume of plasma per unit time leaving the capillaries and entering the bowman's capsule Renal clearance = volume plasma from which a substance is removed per minute by the kidneys Substances used to measure GFR have the following features: 1. Inert 2. Free filtration from the plasma at the glomerulus (not protein bound) 3. Not absorbed or secreted at the tubules 4. Plasma concentration constant during urine collection Examples: inulin, creatinine GFR = urine concentration (mmol/l) x urine volume (ml/min) -------------------------------------------------------------------------- plasma concentration (mmol/l) The clearance of a substance is dependent not only on its diffusivity across the basement membrane but also subsequent tubular secretion and / or reabsorption. So glucose which is freely filtered across the basement membrane is usually reabsorbed from tubules giving a clearance of zero. Tubular function Reabsorption and secretion of substances occurs in the tubules. In the proximal tubule substrates such as glucose, amino acids and phosphate are co-transported with sodium across the semi permeable membrane. Glucose is reabsorbed by both active and passive processes. The former uses sodiumâ€“glucose co-transporters (SGLTs) in the proximal convoluted tubule. The latter achieved through facilitated and passive process through GLUT transporters. Up to two thirds of filtered water is reabsorbed in the proximal tubules. This will lead to increase in urea concentration in the distal tubule allowing for its increased diffusion. Substances to be secreted into the tubules are taken up from the peritubular blood by tubular cells. Solutes such as paraaminohippuric acid are cleared with a single passage through the kidneys and this is why it is used to measure renal plasma flow. Ions such as calcium and phosphate will have a tubular reabsorption that is influenced by plasma PTH levels. Potassium may be both secreted and re-absorbed and is co-exchanged with sodium. Loop of Henle Approximately 60 litres of water containing 9000mmol sodium enters the descending limb of the loop of Henle in 24 hours. Loops from the juxtamedullary nephrons run deep into the medulla. The osmolarity of fluid changes and is greatest at the tip of the papilla. The thick ascending limb is impermeable to water, but highly permeable to sodium and chloride ions. This loss means that at the beginning of the thick ascending limb the fluid is hypo osmotic compared with adjacent interstitial fluid. In the thick ascending limb the reabsorption of sodium and chloride ions occurs by both facilitated and passive diffusion pathways. The loops of Henle are co-located with vasa recta, these will have similar solute compositions to the surrounding extracellular fluid so preventing the diffusion and subsequent removal of this hypertonic fluid. The energy dependent reabsorption of sodium and chloride in the thick ascending limb helps to maintain this osmotic gradient.

Answer 1869

D-Its secretory function is most effective at low systolic blood pressures (typically less than 100mmHg) The proximal convoluted tubule may undergo necrosis in situations such as compartment syndrome. It is responsible for reabsorbing up to two thirds of filtered water. Low systolic blood pressures (below the renal autoregulatory range) are a risk factor for acute tubular necrosis. Within the autoregulatory range the absolute value of systolic BP has little effect. The process of facilitated diffusion of glucose refers to its co-transport with sodium. Renal Physiology Overview Each nephron is supplied with blood from an afferent arteriole that opens onto the glomerular capillary bed. Blood then flows to an efferent arteriole, supplying the peritubular capillaries and medullary vasa recta. The kidney receives up to 25% of resting cardiac output. Control of blood flow The kidney is able to autoregulate its blood flow between systolic pressures of 80- 180mmHg so there is little variation in renal blood flow. This is achieved by myogenic control of arteriolar tone, both sympathetic input and hormonal signals (e.g. renin) are responsible. Glomerular structure and function Blood inside the glomerulus has considerable hydrostatic pressure. The basement membrane has pores that will allow free diffusion of smaller solutes, larger negatively charged molecules such as albumin are unable to cross. The glomerular filtration rate (GFR) is equal to the concentration of a solute in the urine, times the volume of urine produced per minute, divided by the plasma concentration (assuming that the solute is freely diffused e.g. inulin). In clinical practice creatinine is used because it is subjected to very little proximal tubular secretion. Although subject to variability, the typical GFR is 125ml per minute. Glomerular filtration rate = Total volume of plasma per unit time leaving the capillaries and entering the bowman's capsule Renal clearance = volume plasma from which a substance is removed per minute by the kidneys Substances used to measure GFR have the following features: 1. Inert 2. Free filtration from the plasma at the glomerulus (not protein bound) 3. Not absorbed or secreted at the tubules 4. Plasma concentration constant during urine collection Examples: inulin, creatinine GFR = urine concentration (mmol/l) x urine volume (ml/min) -------------------------------------------------------------------------- plasma concentration (mmol/l) The clearance of a substance is dependent not only on its diffusivity across the basement membrane but also subsequent tubular secretion and / or reabsorption. So glucose which is freely filtered across the basement membrane is usually reabsorbed from tubules giving a clearance of zero. Tubular function Reabsorption and secretion of substances occurs in the tubules. In the proximal tubule substrates such as glucose, amino acids and phosphate are co-transported with sodium across the semi permeable membrane. Glucose is reabsorbed by both active and passive processes. The former uses sodiumâ€“glucose co-transporters (SGLTs) in the proximal convoluted tubule. The latter achieved through facilitated and passive process through GLUT transporters. Up to two thirds of filtered water is reabsorbed in the proximal tubules. This will lead to increase in urea concentration in the distal tubule allowing for its increased diffusion. Substances to be secreted into the tubules are taken up from the peritubular blood by tubular cells. Solutes such as paraaminohippuric acid are cleared with a single passage through the kidneys and this is why it is used to measure renal plasma flow. Ions such as calcium and phosphate will have a tubular reabsorption that is influenced by plasma PTH levels. Potassium may be both secreted and re-absorbed and is co-exchanged with sodium. Loop of Henle Approximately 60 litres of water containing 9000mmol sodium enters the descending limb of the loop of Henle in 24 hours. Loops from the juxtamedullary nephrons run deep into the medulla. The osmolarity of fluid changes and is greatest at the tip of the papilla. The thick ascending limb is impermeable to water, but highly permeable to sodium and chloride ions. This loss means that at the beginning of the thick ascending limb the fluid is hypo osmotic compared with adjacent interstitial fluid. In the thick ascending limb the reabsorption of sodium and chloride ions occurs by both facilitated and passive diffusion pathways. The loops of Henle are co-located with vasa recta, these will have similar solute compositions to the surrounding extracellular fluid so preventing the diffusion and subsequent removal of this hypertonic fluid. The energy dependent reabsorption of sodium and chloride in the thick ascending limb helps to maintain this osmotic gradient.

Answer 1870

Mnemonic used to remember some encapsulated pathogens is: 'Even Some Super Killers Have Pretty Nice Big Capsules' Escherichia coli, Streptococcus pneumoniae, Salmonella, Klebsiella pneumoniae, Haemophilus influenzae, Pseudomonas aeruginosa, Neisseria meningitidis, Bacteroides fragilis, and the yeast Cryptococcus neoformans Staphylococcus aureus infection following splenectomy is no more common than in non splenectomised individuals. The other organisms are encapsulated, which is why they are more likely to cause overwhelming post splenectomy sepsis. Post splenectomy sepsis Hyposplenism may complicate certain medical conditions where splenic atrophy occurs or may be the result of medical intervention such as splenic artery embolization and splenectomy for trauma. Diagnosis of hyposplenism is difficult and whilst there may be peripheral markers of the splenectomised state (e.g. Howell Jolly bodies) these are neither 100% sensitive or specific. The most sensitive test is a radionucleotide labeled red cell scan. Hyposplenism, by whatever mechanism it occurs dramatically increases the risk of post splenectomy sepsis, particularly with encapsulated organisms. Since these organisms may be opsonised, but this then goes undetected at an immunological level due to loss of the spleen. For this reason individuals are recommended to be vaccinated and have antibiotic prophylaxis. Key recommendations All those with hyposplenism or may become so (such as prior to an elective splenectomy) should receive pneumococcal, haemophilus type b and meningococcal type C vaccines. These should be administered 2 weeks prior to splenectomy or two weeks following splenectomy. The vaccine schedule for meningococcal disease essentially consists of a dose of Men C and Hib at 2 weeks and then a dose of the MenACWY vaccine one month later. Those aged under 2 may require a booster at 2 years. A dose of pneumococcal polyvalent polysaccharide vaccine (PPV) is given at two weeks. A conjugated vaccine (PCV) is offered to young children. The PCV is more immunogenic but covers fewer serotypes. Boosting PPV is either guided by serological measurements (where available) or by routine boosting doses at 5 yearly intervals. Annual influenza vaccination is recommended in all cases Antibiotic prophylaxis is offered to all. The risk of post splenectomy sepsis is greatest immediately following splenectomy and in those aged less than 16 years or greater than 50 years. Individuals with a poor response to pneumococcal vaccination are another high risk group. High risk individuals should be counselled to take penicillin or macrolide prophylaxis. Those at low risk may choose to discontinue therapy. All patients should be advised about taking antibiotics early in the case of intercurrent infections. Asplenic individuals traveling to malaria endemic areas are at high risk and should have both pharmacological and mechanical protection. Dosing Penicillin V 500mg BD or amoxicillin 250mg BD References Davies J et al. Review of guidelines for the prevention and treatment of infection in patients with an absent or dysfunctional spleen: Prepared on behalf of the British Committee for Standards in Haematology by a Working Party of the Haemato-Oncology Task Force. British Journal of Haematology 2011 (155): 308317.

Answer 1871

Nasal discharge of clear fluid and recent head injury makes a basal skull fracture the most likely underlying diagnosis. Facial nerve palsy Sarcoid Facial nerve palsy is the most frequent neurological manifestation of sarcoid Affects right and left side with equal frequency, may be bilateral Typically resolves in up to 80% of cases Cholesteatoma Destructive and expanding growth of keratinised squamous epithelium Patients often complain of chronic ear discharge Infection with Pseudomonas may occur resulting in foul smell to discharge Aquired lesions usually arise from the Pars flaccida region of the tympanic membrane Surgical removal and mastoidectomy may be needed Recurrence rates of 20% may be seen following surgery Basal skull fracture History of head injury Presence of features such as Battles sign on examination Clinical presence of CSF leak strongly supports diagnosis Assessment is by CT and MRI scan Prophylactic antibiotics should be given in cases of CSF leak

Answer 1872

Painful ulcers associated with a low ABPI are usually arterial in nature. The question does not indicate that features of chronic venous insufficiency are present. Patients may have mild pitting oedema as many vascular patients will also have ischaemic heart disease and elevated right heart pressures. The absence of more compelling signs of venous insufficiency makes a mixed ulcer less likely. Lower leg ulcers Venous leg ulcers Most due to venous hypertension, secondary to chronic venous insufficiency (other causes include calf pump dysfunction or neuromuscular disorders) Ulcers form due to capillary fibrin cuff or leucocyte sequestration Features of venous insufficiency include oedema, brown pigmentation, lipodermatosclerosis, eczema Location above the ankle, painless Deep venous insufficiency is related to previous DVT and superficial venous insufficiency is associated with varicose veins Doppler ultrasound looks for presence of reflux and duplex ultrasound looks at the anatomy/ flow of the vein Management: 4 layer compression banding after exclusion of arterial disease or surgery If fail to heal after 12 weeks or >10cm2 skin grafting may be needed Marjolin's ulcer Squamous cell carcinoma Occurring at sites of chronic inflammation e.g; burns, osteomyelitis after 10-20 years Mainly occur on the lower limb Arterial ulcers Occur on the toes and heel Painful There may be areas of gangrene Cold with no palpable pulses Low ABPI measurements Neuropathic ulcers Commonly over plantar surface of metatarsal head and plantar surface of hallux The plantar neuropathic ulcer is the condition that most commonly leads to amputation in diabetic patients Due to pressure Management includes cushioned shoes to reduce callus formation Pyoderma gangrenosum Associated with inflammatory bowel disease/RA Can occur at stoma sites Erythematous nodules or pustules which ulcerate

Answer 1873

The pancreas develops from a ventral and dorsal endodermal outgrowth of the duodenum. The ventral arises close to, or in common with the hepatic diverticulum, and the larger, dorsal outgrowth arises slightly cranial to the ventral extending into the mesoduodenum and mesogastrium. When the buds eventually fuse the duct of the ventral rudiment becomes the main pancreatic duct. Pancreas The pancreas is a retroperitoneal organ and lies posterior to the stomach. It may be accessed surgically by dividing the peritoneal reflection that connects the greater omentum to the transverse colon. The pancreatic head sits in the curvature of the duodenum. Its tail lies close to the hilum of the spleen, a site of potential injury during splenectomy. Relations Posterior to the pancreas Pancreatic head Inferior vena cava Common bile duct Right and left renal veins Superior mesenteric vein and artery Pancreatic neck Superior mesenteric vein, portal vein Pancreatic body- Left renal vein Crus of diaphragm Psoas muscle Adrenal gland Kidney Aorta Pancreatic tail Left kidney Anterior to the pancreas Pancreatic head 1st part of the duodenum Pylorus SMA and SMV(uncinate process) Pancreatic body Stomach Duodenojejunal flexure Pancreatic tail Splenic hilum Superior to the pancreas Coeliac trunk and its branches common hepatic artery and splenic artery Grooves of the head of the pancreas 2nd and 3rd part of the duodenum Arterial supply Head: pancreaticoduodenal artery Rest: splenic artery Venous drainage Head: superior mesenteric vein Body and tail: splenic vein Ampulla of Vater Merge of pancreatic duct and common bile duct Is an important landmark, halfway along the second part of the duodenum, that marks the anatomical transition from foregut to midgut (also the site of transition between regions supplied by coeliac trunk and SMA).

Answer 1874

The right renal vein is very short and lies more inferiorly. Adrenal gland anatomy Anatomy Location Superomedially to the upper pole of each kidney Relationships of the right adrenal Diaphragm-Posteriorly, Kidney-Inferiorly, Vena Cava-Medially, Hepato-renal pouch and bare area of the liver-Anteriorly Relationships of the left adrenal Crus of the diaphragm-Postero- medially, Pancreas and splenic vessels-Inferiorly, Lesser sac and stomach-Anteriorly Arterial supply Superior adrenal arteries- from inferior phrenic artery, Middle adrenal arteries - from aorta, Inferior adrenal arteries -from renal arteries Venous drainage of the right adrenal Via one central vein directly into the IVC Venous drainage of the left adrenal Via one central vein into the left renal vein

Answer 1875

D-Flexor digitorum profundus Flexor digitorum superficialis and flexor digitorum profundus are responsible for causing flexion. The superficialis tendons insert on the bases of the middle phalanges; the profundus tendons insert on the bases of the distal phalanges. Both tendons flex the wrist, MCP and PIP joints; however, only the profundus tendons flex the DIP joints. Hand Anatomy of the hand Bones 8 Carpal bones 5 Metacarpals 14 phalanges Intrinsic Muscles 8 Interossei - Supplied by ulnar nerve 4 palmar-adduct fingers 4 dorsal- abduct fingers Intrinsic muscles Lumbricals Flex MCPJ and extend the IPJ. Origin deep flexor tendon and insertion dorsal extensor hood mechanism. Innervation: 1st and 2nd- median nerve, 3rd and 4th- deep branch of the ulnar nerve. Thenar eminence Abductor pollicis brevis Opponens pollicis Flexor pollicis brevis Hypothenar eminence Opponens digiti minimi Flexor digiti minimi brevis Abductor digiti minimi Fascia and compartments of the palm The fascia of the palm is continuous with the antebrachial fascia and the fascia of the dorsum of the hand. The palmar fascia is thin over the thenar and hypothenar eminences. In contrast, the central palmar fascia is relatively thick. The palmar aponeurosis covers the soft tissues and overlies the flexor tendons. The apex of the palmar aponeurosis is continuous with the flexor retinaculum and the palmaris longus tendon. Distally, it forms four longitudinal digital bands that attach to the bases of the proximal phalanges, blending with the fibrous digital sheaths. A medial fibrous septum extends deeply from the medial border of the palmar aponeurosis to the 5th metacarpal. Lying medial to this are the hypothenar muscles. In a similar fashion, a lateral fibrous septum extends deeply from the lateral border of the palmar aponeurosis to the 3rd metacarpal. The thenar compartment lies lateral to this area. Lying between the thenar and hypothenar compartments is the central compartment. It contains the flexor tendons and their sheaths, the lumbricals, the superficial palmar arterial arch and the digital vessels and nerves. The deepest muscular plane is the adductor compartment, which contains adductor pollicis. Short muscles of the hand These comprise the lumbricals and interossei. The four slender lumbrical muscles flex the fingers at the metacarpophalangeal joints and extend the interphalangeal joint. The four dorsal interossei are located between the metacarpals and the four palmar interossei lie on the palmar surface of the metacarpals in the interosseous compartment of the hand. Long flexor tendons and sheaths in the hand The tendons of FDS and FDP enter the common flexor sheath deep to the flexor retinaculum. The tendons enter the central compartment of the hand and fan out to their respective digital synovial sheaths. Near the base of the proximal phalanx, the tendon of FDS splits to permit the passage of FDP. The FDP tendons are attached to the margins of the anterior aspect of the base of the distal phalanx. The fibrous digital sheaths contain the flexor tendons and their synovial sheaths. These extend from the heads of the metacarpals to the base of the distal phalanges. Palmar Interossei Note that there are 4 palmar interossei. The first is a small slip of muscle which arises from the ulnar side of the base of the first metacarpal and passes between the head of the first dorsal interosseous and the oblique head of adductor pollicis to insert into the ulnar base of the of the proximal phalanx of the thumb. The second arises from the ulnar side of the body of the second metacarpal and is inserted into the ulnar side of the extensor hood of the index. The third and fourth palmar interossei arise from the radial sides of the bodies of the 4th and 5th metacarpals respectively and insert into the radial sides of the extensor hoods of the ring and little fingers.

Answer 1876

Supraspinatus is an abductor of the shoulder. Shoulder joint Shallow synovial ball and socket type of joint. It is an inherently unstable joint, but is capable to a wide range of movement. Stability is provided by muscles of the rotator cuff that pass from the scapula to insert in the greater tuberosity (all except sub scapularis-lesser tuberosity). Glenoid labrum Fibrocartilaginous rim attached to the free edge of the glenoid cavity Tendon of the long head of biceps arises from within the joint from the supraglenoid tubercle, and is fused at this point to the labrum. The long head of triceps attaches to the infraglenoid tubercle Fibrous capsule Attaches to the scapula external to the glenoid labrum and to the labrum itself (postero-superiorly) Attaches to the humerus at the level of the anatomical neck superiorly and the surgical neck inferiorly Anteriorly the capsule is in contact with the tendon of subscapularis, superiorly with the supraspinatus tendon, and posteriorly with the tendons of infraspinatus and teres minor. All these blend with the capsule towards their insertion. Two defects in the fibrous capsule; superiorly for the tendon of biceps. Anteriorly there is a defect beneath the subscapularis tendon. The inferior extension of the capsule is closely related to the axillary nerve at the surgical neck and this nerve is at risk in anteroinferior dislocations. It also means that proximally sited osteomyelitis may progress to septic arthritis. Movements and muscles Flexion Anterior part of deltoid Pectoralis major Biceps Coracobrachialis Extension Posterior deltoid Teres major Latissimus dorsi Adduction Pectoralis major Latissimus dorsi Teres major Coracobrachialis Abduction Mid deltoid Supraspinatus Medial rotation Subscapularis Anterior deltoid Teres major Latissimus dorsi Lateral rotation Posterior deltoid Infraspinatus Teres minor Important anatomical relations Anteriorly Brachial plexus Axillary artery and vein Posterior Suprascapular nerve Suprascapular vessels Inferior Axillary nerve Circumflex humeral vessels

Answer 1877

Dysplasia = pre cancerous Dysplasia tends to develop as a result of prolonged stimulation by precipitants. Removal of these precipitants may possibly reverse these changes. Replacement of differentiated cells with another cell type describes metaplasia rather than dysplasia. The absence of invasion distinguishes this from malignancy. Dysplasia Premalignant condition Disordered growth and differentiation of cells Alteration in size, shape, and organization of cells Features increased abnormal cell growth (increased number of mitoses/abnormal mitoses and cellular differentiation) Underlying connective tissue is not invaded Causes include smoking, Helicobacter pylori, Human papilloma virus Main differences to metaplasia is that dysplasia is considered to be part of carcinogenesis (pre cancerous) and is associated with a delay in maturation of cells rather than differentiated cells replacing one another The absence of invasion differentiates dysplasia from invasive malignancy Severe dysplasia with foci of invasion are well recognised

Answer 1878

This is amenable to potentially curative resection. The proximal stomach can be conserved. Reconstruction with an anterior gastrojejunostomy will not provide optimal function. A Sleeve gastrectomy is not performed for malignant disease. Gastric cancer Overview There are 700,000 new cases of gastric cancer worldwide each year. It is most common in Japan and less common in western countries. It is more common in men and incidence rises with increasing age. The exact cause of many sporadic cancer is not known, however, familial cases do occur in HNPCC families. In addition, smoking and smoked or preserved foods increase the risk. Japanese migrants retain their increased risk (decreased in subsequent generations). The distribution of the disease in western countries is changing towards a more proximal location (perhaps due to rising obesity). Pathology There is some evidence of support a stepwise progression of the disease through intestinal metaplasia progressing to atrophic gastritis and subsequent dysplasia, through to cancer. The favoured staging system is TNM. The risk of lymph node involvement is related to size and depth of invasion; early cancers confined to submucosa have a 20% incidence of lymph node metastasis. Tumours of the gastro-oesophageal junction are classified as below: Type 1 True oesophageal cancers and may be associated with Barrett's oesophagus. Type 2 Carcinoma of the cardia, arising from cardiac type epithelium or short segments with intestinal metaplasia at the oesophagogastric junction. Type 3 Sub cardial cancers that spread across the junction. Involve similar nodal stations to gastric cancer. Groups for close endoscopic monitoring Intestinal metaplasia of columnar type Atrophic gastritis Low to medium grade dysplasia Patients who have previously undergone resections for benign peptic ulcer disease (except highly selective vagotomy). Referral to endoscopy Patients of any age with dyspepsia and any of the following Patients without dyspepsia Worsening dyspepsia Chronic gastrointestinal bleeding Dysphagia Barretts oesophagus Dysphagia Unexplained abdominal pain or weight loss Intestinal metaplasia Weight loss Vomiting Dysplasia Iron deficiency anaemia Upper abdominal mass Atrophic gastritis Upper abdominal mass Jaundice Patient aged over 55 years with unexplained or persistent dyspepsia Staging CT scanning of the chest abdomen and pelvis is the routine first line staging investigation in most centres. Laparoscopy to identify occult peritoneal disease PET CT (particularly for junctional tumours) Treatment Proximally sited disease greater than 5-10cm from the OG junction may be treated by sub total gastrectomy Total gastrectomy if tumour is <5cm from OG junction For type 2 junctional tumours (extending into oesophagus) oesophagogastrectomy is usual Endoscopic sub mucosal resection may play a role in early gastric cancer confined to the mucosa and perhaps the sub mucosa (this is debated) Lymphadenectomy should be performed. A D2 lymphadenectomy is widely advocated by the Japanese, the survival advantages of extended lymphadenectomy have been debated. However, the overall recommendation is that a D2 nodal dissection be undertaken. Most patients will receive chemotherapy either pre or post operatively. Prognosis UK Data Disease extent Percentage 5 year survival All RO resections 54% Early gastric cancer 91% Stage 1 87% Stage 2 65% Stage 3 18% Operative procedure Total Gastrectomy , lymphadenectomy and Roux en Y anastomosis General anaesthesia Prophylactic intravenous antibiotics Incision: Rooftop. Perform a thorough laparotomy to identify any occult disease. Mobilise the left lobe of the liver off the diaphragm and place a large pack over it. Insert a large self retaining retractor e.g. omnitract or Balfour (take time with this, the set up should be perfect). Pack the small bowel away. Begin by mobilising the omentum off the transverse colon. Proceed to detach the short gastric vessels. Mobilise the pylorus and divide it at least 2cm distally using a linear cutter stapling device. Continue the dissection into the lesser sac taking the lesser omentum and left gastric artery flush at its origin. The lymph nodes should be removed en bloc with the specimen where possible. Place 2 stay sutures either side of the distal oesophagus. Ask the anaesthetist to pull back on the nasogastric tube. Divide the distal oesophagus and remove the stomach. The oesphago jejunal anastomosis should be constructed. Identify the DJ flexure and bring a loop of jejunum up to the oesophagus (to check it will reach). Divide the jejunum at this point. Bring the divided jejunum either retrocolic or antecolic to the oesophagus. Anastamose the oesophagus to the jejunum, using either interrupted 3/0 vicryl or a stapling device. Then create the remainder of the Roux en Y reconstruction distally. Place a jejunostomy feeding tube. Wash out the abdomen and insert drains (usually the anastomosis and duodenal stump). Help the anaesthetist insert the nasogastric tube (carefully!) Close the abdomen and skin. Enteral feeding may commence on the first post-operative day. However, most surgeons will leave patients on free NG drainage for several days and keep them nil by mouth.

Answer 1879

The left brachiocephalic vein lies posterior to the manubrium, at the level of its upper border. The sternal angle refers to the transition between manubrium and sternum and therefore will not include the left brachiocephalic vein. Sternal angle Anatomical structures at the level of the manubrium and upper sternum Upper part of the manubrium Left brachiocephalic vein Brachiocephalic artery Left common carotid Left subclavian artery Lower part of the manubrium/ manubrio-sternal angle Costal cartilages of the 2nd ribs Transition point between superior and inferior mediastinum Arch of the aorta Tracheal bifurcation Union of the azygos vein and superior vena cava The thoracic duct crosses to the midline

Answer 1880

Proximal aortic dissections are generally managed with surgical aortic root replacement. The proximal origin of the dissection together with chest pain (which may occur in all types of aortic dissection) raises concerns about the possibility of coronary ostial involvement (which precludes stenting). There is no role for attempted suture repair in this situation. Aortic dissection More common than rupture of the abdominal aorta 33% of patients die within the first 24 hours, and 50% die within 48 hours if no treatment received Associated with hypertension Features of aortic dissection: tear in the intimal layer, followed by formation and propagation of a subintimal hematoma. Cystic medial necrosis (Marfan's) Most common site of dissection: 90% occurring within 10 centimetres of the aortic valve Stanford Classification Type Location Treatment A Ascending aorta/ aortic root Surgery- aortic root replacement B Descending aorta Medical therapy with antihypertensives DeBakey classification Type Site affected I Ascending aorta, aortic arch, descending aorta II Ascending aorta only III Descending aorta distal to left subclavian artery Clinical features Tearing, sudden onset chest pain (painless 10%) Hypertension or Hypotension A blood pressure difference (in each arm) greater than 20 mm Hg Neurologic deficits (20%) Investigations CXR: widened mediastinum, abnormal aortic knob, ring sign, deviation of the trachea/oesophagus CT angiography of the thoracic aorta MRI angiography Conventional angiography (now rarely used diagnostically) Management Beta-blockers: aim HR 60-80 bpm and systolic BP 100-120 mm Hg For type A dissections the standard of care is aortic root replacement

Answer 1881

Granulomas are organised collections of macrophages Macrophages give origin to granulomas. Chronic inflammation Overview Chronic inflammation may occur secondary to acute inflammation.In most cases chronic inflammation occurs as a primary process. These may be broadly viewed as being one of three main processes: Persisting infection with certain organisms such as Mycobacterium tuberculosis which results in delayed type hypersensitivity reactions and inflammation. Prolonged exposure to non-biodegradable substances such as silica or suture materials which may induce an inflammatory response. Autoimmune conditions involving antibodies formed against host antigens. Acute vs. Chronic inflammation Acute inflammation Chronic inflammation Changes to existing vascular structure and increased permeability of endothelial cells Angiogenesis predominates Infiltration of neutrophils Macrophages, plasma cells and lymphocytes predominate Process may resolve with: Suppuration Complete resolution Abscess formation Progression to chronic inflammation Healing by fibrosis Healing by fibrosis is the main result Granulomatous inflammation A granuloma consists of a microscopic aggregation of macrophages (with epithelial type arrangement =epithelioid). Large giant cells may be found at the periphery of granulomas. Mediators Growth factors released by activated macrophages include agents such as interferon and fibroblast growth factor (plus many more). Some of these such as interferons may have systemic features resulting in systemic symptoms and signs, which may be present in individuals with long standing chronic inflammation. The finding of granulomas is pathognomonic of chronic inflammation, as illustrated in this biopsy from a patient with colonic Crohns disease

Answer 1882

Given this mans ethnic origin and presenting features a nasopharyngeal carcinoma is the most likely underlying diagnosis. Nasopharyngeal carcinoma Squamous cell carcinoma of the nasopharynx Rare in most parts of the world, apart from individuals from Southern China Associated with Epstein Barr virus infection Presenting features Systemic Local Cervical lymphadenopathy Otalgia Unilateral serous otitis media Nasal obstruction, discharge and/ or epistaxis Cranial nerve palsies e.g. III-VI Imaging Combined CT and MRI. Treatment Radiotherapy is first line therapy.

Answer 1883

The triceps muscle extends the elbow joint. The other muscles listed all produce flexion of the elbow joint. Triceps Origin Long head- infraglenoid tubercle of the scapula. Lateral head- dorsal surface of the humerus, lateral and proximal to the groove of the radial nerve Medial head- posterior surface of the humerus on the inferomedial side of the radial groove and both of the intermuscular septae Insertion Olecranon process of the ulna. Here the olecranon bursa is between the triceps tendon and olecranon. Some fibres insert to the deep fascia of the forearm, posterior capsule of the elbow (preventing the capsule from being trapped between olecranon and olecranon fossa during extension) Innervation Radial nerve Blood supply Profunda brachii artery Action Elbow extension. The long head can adduct the humerus and extend it from a flexed position Relations The radial nerve and profunda brachii vessels lie between the lateral and medial heads

Answer 1884

Consider thromboembolism in breast cancer patients on tamoxifen! Venous thromboembolism: risk factors Common predisposing factors include malignancy, pregnancy and the period following an operation. The comprehensive list below is partly based on the 2010 SIGN venous thromboembolism (VTE) guidelines: General increased risk with advancing age obesity family history of VTE pregnancy (especially puerperium) immobility hospitalisation anaesthesia central venous catheter: femoral >> subclavian Underlying conditions malignancy thrombophilia: e.g. Activated protein C resistance, protein C and S deficiency heart failure antiphospholipid syndrome Behcet's polycythaemia nephrotic syndrome sickle cell disease paroxysmal nocturnal haemoglobinuria hyperviscosity syndrome homocystinuria Medication combined oral contraceptive pill: 3rd generation more than 2nd generation hormone replacement therapy raloxifene and tamoxifen antipsychotics (especially olanzapine) have recently been shown to be a risk factor SIGN also state that the following are risk factors for recurrent VTE: previous unprovoked VTE male sex obesity thrombophilias

Answer 1885

The fact that he is frail (care home resident) and has already suffered a cardiac arrest means that attempts at surgery will invariably fail. At 89 years of age the functional outcomes were it to be 'successful' would be very poor. Palliation is therefore the best option, imaging will not change this management decision. Abdominal aorta aneurysm - Abdominal aortic aneurysms are a common problem in vascular surgery. They may occur as either true or false aneurysm. With the former all 3 layers of the arterial wall are involved, in the latter only a single layer of fibrous tissue forms the aneurysm wall. True abdominal aortic aneurysms have an approximate incidence of 0.06 per 1000 people. They are commonest in elderly men and for this reason the UK is now introducing the aneurysm screening program with the aim of performing an abdominal aortic ultrasound measurement in all men aged 65 years. Causes Several different groups of patients suffer from aneurysmal disease. The commonest group is those who suffer from standard arterial disease, i.e. Those who are hypertensive and have been or are smokers. Other patients such as those suffering from connective tissue diseases such as Marfan's may also develop aneurysms. In patients with abdominal aortic aneurysms the extracellular matrix becomes disrupted with a change in the balance of collagen and elastic fibres. Management Most abdominal aortic aneurysms are an incidental finding. Symptoms most often relate to rupture or impending rupture. 20% rupture anteriorly into the peritoneal cavity. Very poor prognosis. 80% rupture posteriorly into the retroperitoneal space The risk of rupture is related to aneurysm size, only 2% of aneurysms measuring less than 4cm in diameter will rupture over a 5 year period. This contrasts with 75% of aneurysms measuring over 7cm in diameter. This is well explained by Laplaces' law which relates size to transmural pressure. For this reason most vascular surgeons will subject patients with an aneurysm size of 5cm or greater to CT scanning of the chest, abdomen and pelvis with the aim of delineating anatomy and planning treatment. Depending upon co-morbidities, surgery is generally offered once the aneurysm is between 5.5cm and 6cm. Indications for surgery Symptomatic aneurysms (80% annual mortality if untreated) Increasing size above 5.5cm if asymptomatic Rupture (100% mortality without surgery) Surgical procedures Abdominal aortic aneurysm repair Procedure: GA Invasive monitoring (A-line, CVP, catheter) Incision: Midline or transverse Bowel and distal duodenum mobilised to access aorta. Aneurysm neck and base dissected out and prepared for cross clamp Systemic heparinisation Cross clamp (proximal first) Longitudinal aortotomy Atherectomy Deal with back bleeding from lumbar vessels and inferior mesenteric artery Insert graft either tube or bifurcated depending upon anatomy Suture using Prolene (3/0 for proximal , distal anastomosis suture varies according to site) Clamps off: End tidal CO2 will rise owing to effects of reperfusion, at this point major risk of myocardial events. Haemostasis Closure of aneurysm sac to minimise risk of aorto-enteric fistula Closure: Loop 1 PDS or Prolene to abdominal wall Skin- surgeons preference Post operatively: ITU (Almost all) Greatest risk of complications following emergency repair Complications: Embolic- gut and foot infarcts Cardiac - owing to premorbid states, re-perfusion injury and effects of cross clamp Wound problems Later risks related to graft- infection and aorto-enteric fistula Special groups Supra renal AAA These patients will require a supra renal clamp and this carries a far higher risk of complications and risk of renal failure. Ruptured AAA Pre-operatively the management depends upon haemodynamic instability. In patients with symptoms of rupture (typical pain, haemodynamic compromise and risk factors) then ideally prompt laparotomy. In those with vague symptoms and haemodynamic stability the ideal test is CT scan to determine whether rupture has occurred or not. Most common rupture site is retroperitoneal 80%. These patients will tend to develop retroperitoneal haematoma. This can be disrupted if Bp is allowed to rise too high so aim for Bp 100mmHg. Operative details are similar to elective repair although surgery should be swift, blind rushing often makes the situation worse. Plunging vascular clamps blindly into a pool of blood at the aneurysm neck carries the risk of injury the vena cava that these patients do not withstand. Occasionally a supracoeliac clamp is needed to effect temporary control, although leaving this applied for more than 20 minutes tends to carry a dismal outcome. EVAR Increasingly patients are now being offered endovascular aortic aneurysm repair. This is undertaken by surgeons and radiologists working jointly. The morphology of the aneurysm is important and not all are suitable. Here is a typical list of those features favoring a suitable aneurysm: Long neck Straight iliac vessels Healthy groin vessels Clearly few AAA patients possess the above and compromise has to be made. The use of fenestrated grafts can allow supra renal AAA to be treated. Procedure: GA Radiology or theatre Bilateral groin incisions Common femoral artery dissected out Heparinisation Arteriotomy and insertion of guide wire Dilation of arteriotomy Insertion of EVAR Device Once in satisfactory position it is released Arteriotomy closed once check angiogram shows good position and no endoleak Complications: Endoleaks depending upon site are either Type I or 2. These may necessitate re-intervention and all EVAR patients require follow up . Details are not needed for MRCS. References A reasonable review is provided by: Sakalihasan N, Limet R, Defawe O. Abdominal aortic aneurysm. Lancet 2005 (365):1577- 1589

Answer 1886

Hypersensitivity reactions: ACID type 1 --Anaphylactic type 2 --Cytotoxic type 3 --Immune complex type 4 --Delayed hypersensitivity Contact dermatitis of a chronic nature is an example of a type 4 hypersensitivity reaction. Type 4 hypersensitivity reactions are cell mediated rather than antibody mediated. Hypersensitivity reactions The Gell and Coombs classification divides hypersensitivity reactions into 4 types Type I Type II Type III Type IV Description Anaphylactic Cytotoxic Immune complex Delayed type Mediator IgE IgG, IgM IgG, Ig A, IgM T-cells Antigen Exogenous Cell surface Soluble Tissues Response time Minutes Hours Hours 2-3 days Examples Asthma Hay fever Autoimmune haemolytic anaemia Pemphigus Goodpasture's Serum sickness SLE Aspergillosis Graft versus host disease Contact dermatitis

Answer 1887

The pudendal nerve may innervate the posterior skin of the scrotum. The anterior innervation of the scrotum is primarily provided by the ilioinguinal nerve. The genital branch of the genitofemoral nerve provides a smaller contribution. Scrotal sensation The scrotum is innervated by the ilioinguinal nerve and the pudendal nerve. The ilioinguinal nerve arises from L1 and pierces the internal oblique muscle. It eventually passes through the superficial inguinal ring to innervate the anterior skin of the scrotum. The pudendal nerve is the principal nerve of the perineum. It arises in the pelvis from 3 nerve roots. It passes through both greater and lesser sciatic foramina to enter the perineal region. The perineal branches pass anteromedially and divide into posterior scrotal branches. The posterior scrotal branches pass superficially to supply the skin and fascia of the perineum. It cross communicates with the inferior rectal nerve.

Answer 1888

There are many causes of the irritable hip in the 10-14 year age group. Many of these may cause both hip pain or knee pain. Transient synovitis of the hip the commonest disorder but does not typically last for 3 months. An osteosarcoma would not usually present with apparent limb shortening unless pathological fracture had occurred. A slipped upper femoral epiphysis can cause a similar presentation although it typically presents later and with different patient characteristics. Perthes disease Perthes disease Idiopathic avascular necrosis of the femoral epiphysis of the femoral head Impaired blood supply to femoral head, causing bone infarction. New vessels develop and ossification occurs. The bone either heals or a subchondral fracture occurs. Clinical features Males 4x's greater than females Age between 2-12 years (the younger the age of onset, the better the prognosis) Limp Hip pain Bilateral in 20% Diagnosis Plain x-ray, Technetium bone scan or magnetic resonance imaging if normal x-ray and symptoms persist. Catterall staging Stage Features Stage 1 Clinical and histological features only Stage 2 Sclerosis with or without cystic changes and preservation of the articular surface Stage 3 Loss of structural integrity of the femoral head Stage 4 Loss of acetabular integrity Management To keep the femoral head within the acetabulum: cast, braces If less than 6 years: observation Older: surgical management with moderate results Operate on severe deformities Prognosis Most cases will resolve with conservative management. Early diagnosis improves outcomes.

Answer 1889

Urodynamic studies are indicated when there is diagnostic uncertainty or plans for surgery. Urinary incontinence Involuntary passage of urine. Most cases are female (80%). It has a prevalence of 11% in those aged greater than 65 years. The commonest variants include: Stress urinary incontinence (50%) Urge incontinence (15%) Mixed (35%) Males Males may also suffer from incontinence although it is a much rarer condition in men. A number of anatomical factors contribute to this. Males have 2 powerful sphincters; one at the bladder neck and the other in the urethra. Damage to the bladder neck mechanism is a factor in causing retrograde ejaculation following prostatectomy. The short segment of urethra passing through the urogenital diaphragm consists of striated muscle fibres (the external urethral sphincter) and smooth muscle capable of more sustained contraction. It is the latter mechanism that maintains continence following prostatectomy. Females The sphincter complex at the level of bladder neck is poorly developed in females. As a result the external sphincter complex is functionally more important, its composition being similar to that of males. Innervation is via the pudendal nerve and the neuropathy that may accompany obstetric events may compromise this and lead to stress urinary incontinence. Innervation Somatic innervation to the bladder is via the pudendal, hypogastric and pelvic nerves. Autonomic nerves travel in these nerve fibres too. Bladder filling leads to detrusor relaxation (sympathetic) coupled with sphincter contraction. The parasympathetic system causes detrusor contraction and sphincter relaxation. Overall control of micturition is centrally mediated via centres in the Pons. Stress urinary incontinence 50% of cases, especially in females. Damage (often obstetric) to the supporting structures surrounding the bladder may lead to urethral hypermobility. Other cases due to sphincter dysfunction, usually from neurological disorders (e.g. Pudendal neuropathy, multiple sclerosis). Urethral mobility: Pressure not transmitted appropriately to the urethra resulting in involuntary passage of urine during episodes of raised intra-abdominal pressure. Sphincter dysfunction: Sphincter fails to adapt to compress urethra resulting in involuntary passage of urine. When the sphincter completely fails there is often to continuous passage of urine. Urge incontinence In these patients there is sense of urgency followed by incontinence. The detrusor muscle in these patients is unstable and urodynamic investigation will demonstrate overactivity of the detrusor muscle at inappropriate times (e.g. Bladder filling). Urgency may be seen in patients with overt neurological disorders and those without. The pathophysiology is not well understood but poor central and peripheral co-ordination of the events surrounding bladder filling are the main processes. Assessment Careful history and examination including vaginal examination for cystocele. Bladder diary for at least 3 days Consider flow cystometry if unclear symptomatology or surgery considered and diagnosis is unclear. Exclusion of other organic disease (e.g. Stones, UTI, Cancer) Management Conservative measures should be tried first; Stress urinary incontinence or mixed symptoms should undergo 3 months of pelvic floor exercise. Over active bladder should have 6 weeks of bladder retraining. Drug therapy for women with overactive bladder should be offered oxybutynin (or solifenacin if elderly) if conservative measures fail. In women with detrusor instability who fail non operative therapy a trial of sacral neuromodulation may be considered, with conversion to permanent implant if good response. Augmentation cystoplasty is an alternative but will involve long term intermittent self catheterisation. In women with stress urinary incontinence a urethral sling type procedure may be undertaken. Where cystocele is present in association with incontinence it should be repaired particularly if it lies at the introitus. NICE guidelines Initial assessment urinary incontinence should be classified as stress/urge/mixed. At least 3/7 bladder diary if unable to classify easily. Start conservative treatment before urodynamic studies if a diagnosis is obvious from the history Urodynamic studies if plans for surgery. Stress incontinence: Pelvic floor exercises 3/12, if fails consider surgery. Urge incontinence: Bladder training >6/52, if fails for oxybutynin (antimuscarinic drugs) then sacral nerve stimulation. Pelvic floor exercises offered to all women in their 1st pregnancy.

Answer 1890

Blood group O is not a risk factor for oesophageal cancer. Achalasia is associated with the risk of developing squamous cell carcinoma of the oesophagus. Oesophageal cancer - Incidence is increasing In most cases in the Western world this increase is accounted for by a rise in the number of cases of adenocarcinoma. In the UK adenocarcinomas account for 65% of cases. Barretts oesophagus is a major risk factor for most cases of oesophageal adenocarcinoma. In other regions of the world squamous cancer is more common and is linked to smoking, alcohol intake, diets rich in nitrosamines and achalasia. Surveillance of Barretts is important, as it imparts a 30 fold increase in cancer risk and if invasive malignancy is diagnosed early then survival may approach 85% at 5 years. Diagnosis Upper GI endoscopy is the first line test Contrast swallow may be of benefit in classifying benign motility disorders but has no place in the assessment of tumours Staging is initially undertaken with CT scanning of the chest, abdomen and pelvis. If overt metastatic disease is identified using this modality then further complex imaging is unnecessary If CT does not show metastatic disease, then local stage may be more accurately assessed by use of endoscopic ultrasound. Staging laparoscopy is performed to detect occult peritoneal disease. PET CT is performed in those with negative laparoscopy. Thoracoscopy is not routinely performed. Treatment Operable disease is best managed by surgical resection. The most standard procedure is an Ivor- Lewis type oesophagectomy. This procedure involves the mobilisation of the stomach and division of the oesophageal hiatus. The abdomen is closed and a right sided thoracotomy performed. The stomach is brought into the chest and the oesophagus mobilised further. An intrathoracic oesophagogastric anastomosis is constructed. Alternative surgical strategies include a transhiatal resection (for distal lesions), a left thoraco-abdominal resection (difficult access due to thoracic aorta) and a total oesophagectomy (McKeown) with a cervical oesophagogastric anastomosis. The biggest surgical challenge is that of anastomotic leak, with an intrathoracic anastomosis this will result in mediastinitis. With high mortality. The McKeown technique has an intrinsically lower systemic insult in the event of anastomotic leakage. In addition to surgical resection many patients will be treated with adjuvant chemotherapy.

Answer 1891

Multifocal disease is a recognised feature of papillary lesions. Papillary adenomas are not really recognised and most well differentiated lesions are papillary carcinomas. Thyroid neoplasms Lesion Common features Follicular adenoma Usually present as a solitary thyroid nodule Malignancy can only be excluded on formal histological assessment Papillary carcinoma Usually contain a mixture of papillary and colloidal filled follicles Histologically tumour has papillary projections and pale empty nuclei Seldom encapsulated Lymph node metastasis predominate Haematogenous metastasis rare Account for 60% of thyroid cancers Follicular carcinoma May appear macroscopically encapsulated, microscopically capsular invasion is seen. Without this finding the lesion is a follicular adenoma. Vascular invasion predominates Multifocal disease rare Account for 20% of all thyroid cancers Anaplastic carcinoma Most common in elderly females Local invasion is a common feature Account for 10% of thyroid cancers Treatment is by resection where possible, palliation may be achieved through isthmusectomy and radiotherapy. Chemotherapy is ineffective. Medullary carcinoma Tumours of the parafollicular cells (C Cells) C cells derived from neural crest and not thyroid tissue Serum calcitonin levels often raised Familial genetic disease accounts for up to 20% cases Both lymphatic and haematogenous metastasis are recognised, nodal disease is associated with a very poor prognosis.

Answer 1892

The thoracoacromial artery pierces the pectoralis major and gives off branches within this space. The level 3 axillary nodes lie between pectoralis major and minor.Although the thoracodorsal trunk may be injured during an axillary dissection it does not lie within the level 3 nodes. Thoracoacromial artery The thoracoacromial artery (acromiothoracic artery; thoracic axis) is a short trunk, which arises from the forepart of the axillary artery, its origin being generally overlapped by the upper edge of the Pectoralis minor. Projecting forward to the upper border of the Pectoralis minor, it pierces the coracoclavicular fascia and divides into four branches: pectoral, acromial, clavicular, and deltoid. Branch Description Pectoral branch Descends between the two Pectoral muscles, and is distributed to them and to the breast, anastomosing with the intercostal branches of the internal thoracic artery and with the lateral thoracic. Acromial branch Runs laterally over the coracoid process and under the Deltoid, to which it gives branches; it then pierces that muscle and ends on the acromion in an arterial network formed by branches from the suprascapular, thoracoacromial, and posterior humeral circumflex arteries. Clavicular branch Runs upwards and medially to the sternoclavicular joint, supplying this articulation, and the Subclavius. Deltoid branch Arising with the acromial, it crosses over the Pectoralis minor and passes in the same groove as the cephalic vein, between the Pectoralis major and Deltoid, and gives branches to both muscles.

Answer 1893

Neuroblastomas are a relatively common childhood tumour and have a strong tendency to developing widespread lytic metastasis. It is unusual for CNS tumours to spread to involve the skeleton. Secondary malignant tumours of bone Metastatic lesions affecting bone are more common than primary bone tumours. The typical tumours that spread to bone include: Breast Bronchus Renal Thyroid Prostate 75% cases will affect those over the age of 50 The commonest bone sites affected are: Vertebrae (usually thoracic) Proximal femur Ribs Sternum Pelvis Skull Pathological fracture Osteolytic lesions are the greatest risk for pathological fracture The risk and load required to produce fracture varies according to bone site. Bones with lesions that occupy 50% or less will be prone to fracture under loading (Harrington). When 75% of the bone is affected the process of torsion about a bony fulcrum may produce a fracture. The Mirel scoring[1] system may be used to help determine the risk of fracture and is more systematic than the Harrington system described above. Mirel Scoring system Score points Site Radiographic appearance Width of bone involved Pain 1 Upper extremity Blastic Less than 1/3 Mild 2 Lower extremity Mixed 1/3 to 2/3 Moderate 3 Peritrochanteric Lytic More than 2/3 Aggravated by function Depending upon the score the treatment should be as follows: Score Risk of fracture Treatment 9 or greater Impending (33%) Prophylactic fixation 8 Borderline Consider fixation 7 or less Not impending (4%) Non operative management Where the lesion is an isolated metastatic deposit consideration should be given to excision and reconstruction as the outcome is better [2]. Non operative treatments Hypercalcaemia- Treat with re hydration and bisphosphonates. Pain- Opiate analgesics and radiotherapy. Some tumours such as breast and prostate will benefit from chemotherapy and or hormonal agents. References 1. Mirels, H. Metastatic disease in long bones. A proposed scoring system for diagnosing impending pathologic fractures. Clin Orthop Relat Res, 1989(249): p. 256-64. 2. Mavrogenis, A.F. et al. Survival analysis of patients with femoral metastases. J Surg Oncol, 2011.

Answer 1894

It is bilateral in 50% of cases. Talipes Equinovarus Congenital talipes equinovarus. Features: Equinus of the hindfoot Adduction and varus of the midfoot High arch Most cases in developing countries. Incidence in UK is 1 per 1000 live births. It is more common in males and is bilateral in 50% cases. There is a strong familial link(1). It may also be associated with other developmental disorders such as Down's syndrome. Key anatomical deformities (2): Adducted and inverted calcaneus Wedge shaped distal calcaneal articular surface Severe Tibio-talar plantar flexion Medial Talar neck inclination Displacement of the navicular bone (medially) Wedge shaped head of talus Displacement of the cuboid (medially) Management Conservative first, the Ponseti method is best described and gives comparable results to surgery. It consists of serial casting to mold the foot into correct shape. Following casting around 90% will require a Achilles tenotomy. This is then followed by a phase of walking braces to maintain the correction. Surgical correction is reserved for those cases that fail to respond to conservative measures. The procedures involve multiple tenotomies and lengthening procedures. In patients who fail to respond surgically an Ilizarov frame reconstruction may be attempted and gives good results. References 1. Wynne-Davies R, Littlejohn A, Gormley J. Aetiology and interrelationship of some common skeletal deformities. (Talipes equinovarus and calcaneovalgus, metatarsus varus, congenital dislocation of the hip, and infantile idiopathic scoliosis). J Med Genet. 1982 Oct;19(5):321-8. 2. Horn BD, Davidson RS. Current treatment of clubfoot in infancy and childhood. Foot Ankle Clin. 2010 Jun;15(2):235-43. 3. Clarke NM, Uglow MG, Valentine KM. Comparison of Ponseti Versus Surgical Treatment in Congenital Talipes Equinovarus. J Foot Ankle Surg. 2011 Jun 14.

Answer 1895

The key feature here is the sudden nature of the collapse, this suggests a significant intra abdominal catastrophe. The history of back pain is also suggestive of recent aneurysm expansion. Abdominal aorta aneurysm - Abdominal aortic aneurysms are a common problem in vascular surgery. They may occur as either true or false aneurysm. With the former all 3 layers of the arterial wall are involved, in the latter only a single layer of fibrous tissue forms the aneurysm wall. True abdominal aortic aneurysms have an approximate incidence of 0.06 per 1000 people. They are commonest in elderly men and for this reason the UK is now introducing the aneurysm screening program with the aim of performing an abdominal aortic ultrasound measurement in all men aged 65 years. Causes Several different groups of patients suffer from aneurysmal disease. The commonest group is those who suffer from standard arterial disease, i.e. Those who are hypertensive and have been or are smokers. Other patients such as those suffering from connective tissue diseases such as Marfan's may also develop aneurysms. In patients with abdominal aortic aneurysms the extracellular matrix becomes disrupted with a change in the balance of collagen and elastic fibres. Management Most abdominal aortic aneurysms are an incidental finding. Symptoms most often relate to rupture or impending rupture. 20% rupture anteriorly into the peritoneal cavity. Very poor prognosis. 80% rupture posteriorly into the retroperitoneal space The risk of rupture is related to aneurysm size, only 2% of aneurysms measuring less than 4cm in diameter will rupture over a 5 year period. This contrasts with 75% of aneurysms measuring over 7cm in diameter. This is well explained by Laplaces' law which relates size to transmural pressure. For this reason most vascular surgeons will subject patients with an aneurysm size of 5cm or greater to CT scanning of the chest, abdomen and pelvis with the aim of delineating anatomy and planning treatment. Depending upon co-morbidities, surgery is generally offered once the aneurysm is between 5.5cm and 6cm. Indications for surgery Symptomatic aneurysms (80% annual mortality if untreated) Increasing size above 5.5cm if asymptomatic Rupture (100% mortality without surgery) Surgical procedures Abdominal aortic aneurysm repair Procedure: GA Invasive monitoring (A-line, CVP, catheter) Incision: Midline or transverse Bowel and distal duodenum mobilised to access aorta. Aneurysm neck and base dissected out and prepared for cross clamp Systemic heparinisation Cross clamp (proximal first) Longitudinal aortotomy Atherectomy Deal with back bleeding from lumbar vessels and inferior mesenteric artery Insert graft either tube or bifurcated depending upon anatomy Suture using Prolene (3/0 for proximal , distal anastomosis suture varies according to site) Clamps off: End tidal CO2 will rise owing to effects of reperfusion, at this point major risk of myocardial events. Haemostasis Closure of aneurysm sac to minimise risk of aorto-enteric fistula Closure: Loop 1 PDS or Prolene to abdominal wall Skin- surgeons preference Post operatively: ITU (Almost all) Greatest risk of complications following emergency repair Complications: Embolic- gut and foot infarcts Cardiac - owing to premorbid states, re-perfusion injury and effects of cross clamp Wound problems Later risks related to graft- infection and aorto-enteric fistula Special groups Supra renal AAA These patients will require a supra renal clamp and this carries a far higher risk of complications and risk of renal failure. Ruptured AAA Pre-operatively the management depends upon haemodynamic instability. In patients with symptoms of rupture (typical pain, haemodynamic compromise and risk factors) then ideally prompt laparotomy. In those with vague symptoms and haemodynamic stability the ideal test is CT scan to determine whether rupture has occurred or not. Most common rupture site is retroperitoneal 80%. These patients will tend to develop retroperitoneal haematoma. This can be disrupted if Bp is allowed to rise too high so aim for Bp 100mmHg. Operative details are similar to elective repair although surgery should be swift, blind rushing often makes the situation worse. Plunging vascular clamps blindly into a pool of blood at the aneurysm neck carries the risk of injury the vena cava that these patients do not withstand. Occasionally a supracoeliac clamp is needed to effect temporary control, although leaving this applied for more than 20 minutes tends to carry a dismal outcome. EVAR Increasingly patients are now being offered endovascular aortic aneurysm repair. This is undertaken by surgeons and radiologists working jointly. The morphology of the aneurysm is important and not all are suitable. Here is a typical list of those features favoring a suitable aneurysm: Long neck Straight iliac vessels Healthy groin vessels Clearly few AAA patients possess the above and compromise has to be made. The use of fenestrated grafts can allow supra renal AAA to be treated. Procedure: GA Radiology or theatre Bilateral groin incisions Common femoral artery dissected out Heparinisation Arteriotomy and insertion of guide wire Dilation of arteriotomy Insertion of EVAR Device Once in satisfactory position it is released Arteriotomy closed once check angiogram shows good position and no endoleak Complications: Endoleaks depending upon site are either Type I or 2. These may necessitate re-intervention and all EVAR patients require follow up . Details are not needed for MRCS. References A reasonable review is provided by: Sakalihasan N, Limet R, Defawe O. Abdominal aortic aneurysm. Lancet 2005 (365):1577- 1589

Answer 1896

This is a classical description. Collection of dilated lymphatic sacs which are fluctuant and brilliantly transilluminable. Recurrence following surgical excision is not uncommon. Neck lumps The table below gives characteristic exam question features for conditions causing neck lumps: Reactive lymphadenopathy By far the most common cause of neck swellings. There may be a history of local infection or a generalised viral illness Lymphoma Rubbery, painless lymphadenopathy The phenomenon of pain whilst drinking alcohol is very uncommon There may be associated night sweats and splenomegaly Thyroid swelling May be hypo-, eu- or hyperthyroid symptomatically Moves upwards on swallowing Thyroglossal cyst More common in patients < 20 years old Usually midline, between the isthmus of the thyroid and the hyoid bone Moves upwards with protrusion of the tongue May be painful if infected Pharyngeal pouch More common in older men Represents a posteromedial herniation between thyropharyngeus and cricopharyngeus muscles Usually not seen, but if large then a midline lump in the neck that gurgles on palpation Typical symptoms are dysphagia, regurgitation, aspiration and chronic cough Cystic hygroma A congenital lymphatic lesion (lymphangioma) typically found in the neck, classically on the left side Most are evident at birth, around 90% present before 2 years of age Branchial cyst An oval, mobile cystic mass that develops between the sternocleidomastoid muscle and the pharynx Develop due to failure of obliteration of the second branchial cleft in embryonic development Usually present in early adulthood Cervical rib More common in adult females Around 10% develop thoracic outlet syndrome Carotid aneurysm Pulsatile lateral neck mass which doesn't move on swallowing

Answer 1897

Atracurium is degraded by a process of ester hydrolysis. This uses non specific plasma esterases. Muscle relaxants Suxamethonium Depolarising neuromuscular blocker Inhibits action of acetylcholine at the neuromuscular junction Degraded by plasma cholinesterase and acetylcholinesterase (affected by lack of acetylcholinesterase) Fastest onset and shortest duration of action of all muscle relaxants Produces generalised muscular contraction prior to paralysis Adverse effects include hyperkalaemia, malignant hyperthermia, delayed recovery Atracurium Non depolarising neuromuscular blocking drug Duration of action usually 30-45 minutes Generalised histamine release on administration may produce facial flushing, tachycardia and hypotension Not excreted by liver or kidney, broken down in tissues by hydrolysis Reversed by neostigmine Vecuronium Non depolarising neuromuscular blocking drug Duration of action approximately 30 - 40 minutes Degraded by liver and kidney and effects prolonged in organ dysfunction Effects may be reversed by neostigmine Pancuronium Non depolarising neuromuscular blocker Onset of action approximately 2-3 minutes Duration of action up to 2 hours Effects may be partially reversed with drugs such as neostigmine

Answer 1898

E=3, V=4, M=6. Glasgow coma scale Modality Options Eye opening Spontaneous To speech To pain None Verbal response Orientated Confused Words Sounds None Motor response Obeys commands Localises to pain Withdraws from pain Abnormal flexion to pain (decorticate posture) Extending to pain None Responses are taken from each category (marks in descending order) to produce an overall score. Severe brain injuries are generally associated with GCS <8.

Answer 1899

Relative Glucocorticoid activity: Hydrocortisone = 1 Prednisolone = 4 Dexamethasone = 25 Cortisol is produced by the zona fasciculata of the adrenal gland. Cortisol Glucocorticoid Released by zona fasiculata of the adrenal gland 90% protein bound; 10% active Circadian rhythm: High in the mornings Negative feedback via ACTH Actions Glycogenolysis Gluconeogenesis Protein catabolism Lipolysis Stress response Anti-inflammatory Decrease protein in bones Increase gastric acid Increases neutrophils/platelets/red blood cells Inhibits fibroblastic activity

Answer 1900

Acute haemorrhage and associated shock exceed the renovascular compensatory mechanisms. This results in renovascular vasoconstriction of glomerulotubular hypoperfusion. This can result is acute tubular necrosis. An acute inflammatory nephritis is less likely in this setting. Acute Renal Failure - Final pathway is tubular cell death. Renal medulla is a relatively hypoxic environment making it susceptible to renal tubular hypoxia. Renovascular autoregulation maintains renal blood flow across a range of arterial pressures. Estimates of GFR are best indices of level of renal function. Useful clinical estimates can be obtained by considering serum creatinine, age, race, gender and body size. eGFR calculations such as the Cockcroft and Gault equation are less reliable in populations with high GFR's. Nephrotoxic stimuli such as aminoglycosides and radiological contrast media induce apoptosis. Myoglobinuria and haemolysis result in necrosis. Overlap exists and proinflammatory cytokines play an important role in potentiating ongoing damage. Post-operative renal failure is more likely to occur in patients who are elderly, have peripheral vascular disease, high BMI, have COPD, receive vasopressors, are on nephrotoxic medication or undergo emergency surgery. Avoiding hypotension will reduce risk of renal tubular damage. There is no evidence that administration of ACE inhibitors or dopamine reduces the incidence of post-operative renal failure.

Answer 1901

Bile salt reabsorption occurs at the ileum. Therefore cholesterol gallstones form as a result of ileal resection. Biliary disease Diagnosis Typical features Pathogenesis Gallstones Typically history of biliary colic or episodes of chlolecystitis. Obstructive type history and test results. Usually small calibre gallstones which can pass through the cystic duct. In Mirizzi syndrome the stone may compress the bile duct directly- one of the rare times that cholecystitis may present with jaundice Cholangitis Usually obstructive and will have Charcot's triad of symptoms (pain, fever, jaundice) Ascending infection of the bile ducts usually by E. coli and by definition occurring in a pool of stagnant bile. Pancreatic cancer Typically painless jaundice with palpable gallbladder (Courvoisier's Law) Direct occlusion of distal bile duct or pancreatic duct by tumour. Sometimes nodal disease at the portal hepatis may be the culprit in which case the bile duct may be of normal calibre. TPN (total parenteral nutrition) associated jaundice Usually follows long term use and is usually painless with non obstructive features Often due to hepatic dysfunction and fatty liver which may occur with long term TPN usage. Bile duct injury Depending upon the type of injury may be of sudden or gradual onset and is usually of obstructive type Often due to a difficult laparoscopicÂ cholecystectomy when anatomy in Calots triangle is not appreciated. In the worst scenario the bile duct is excised and jaundice develops rapidly post operatively. More insidious is that of bile duct stenosis which may be caused by clips or diathermy injury. Cholangiocarcinoma Gradual onset obstructive pattern Direct occlusion by disease and also extrinsic compression by nodal disease at the porta hepatis. Septic surgical patient Usually hepatic features Combination of impaired biliary excretion and drugs such as ciprofloxacin which may cause cholestasis. Metastatic disease Mixed hepatic and post hepatic Combination of liver synthetic failure (late) and extrinsic compression by nodal disease and anatomical compression of intra hepatic structures (earlier)

Answer 1902

Hilar injuries usually mandate splenectomy. The main risk with conservative management here is that he will rebleed and with hilar injuries this can be dramatic. Splenic trauma - The spleen is one of the more commonly injured intra abdominal organs In most cases the spleen can be conserved. The management is dictated by the associated injuries, haemodynamic status and extent of direct splenic injury. Management of splenic trauma Conservative Small subcapsular haematoma Minimal intra abdominal blood No hilar disruption Laparotomy with conservation Increased amounts of intraabdominal blood Moderate haemodynamic compromise Tears or lacerations affecting <50% Resection Hilar injuries Major haemorrhage Major associated injuries Splenectomy Technique Trauma GA Long midline incision If time permits insert a self retaining retractor (e.g. Balfour/ omnitract) Large amount of free blood is usually present. Pack all 4 quadrants of the abdomen. Allow the anaesthetist to 'catch up' Remove the packs and assess the viability of the spleen. Hilar injuries and extensive parenchymal lacerations will usually require splenectomy. Divide the short gastric vessels and ligate them. Clamp the splenic artery and vein. Two clamps on the patient side are better and allow for double ligation and serve as a safety net if your assistant does not release the clamp smoothly. Be careful not to damage the tail of the pancreas, if you do then this will need to be formally removed and the pancreatic duct closed. Wash out the abdomen and place a tube drain to the splenic bed. Some surgeons implant a portion of spleen into the omentum, whether you decide to do this is a matter of personal choice. Post operatively the patient will require prophylactic penicillin V and pneumococcal vaccine. Elective Elective splenectomy is a very different operation from that performed in the emergency setting. The spleen is often large (sometimes massive). Most cases can be performed laparoscopically. The spleen will often be macerated inside a specimen bag to facilitate extraction. Complications Haemorrhage (may be early and either from short gastrics or splenic hilar vessels Pancreatic fistula (from iatrogenic damage to pancreatic tail) Thrombocytosis: prophylactic aspirin Encapsulated bacteria infection e.g. Strep. pneumoniae, Haemophilus influenzae and Neisseria meningitidis

Answer 1903

Partial thickness burns are divided into superficial and deep burns, however, this is often not possible on initial assessment and it may be a week or more before the distinction is clear cut. Dermal appendages are, by definition, intact. Superficial partial thickness burns will typically heal by re-epithelialisation, deeper burns will heal with scarring. Burns Burns may be thermal, chemical or electrical. In the former category are burns which occur as a result of heat. Chemical burns occur when the skin is exposed to an extremely caustic or alkaline substance. Electrical burns occur following exposure to electrical current. The immediate management includes removal of the burning source which usually includes irrigation of the burned area. A detailed assessment then needs to be made of the extent of the burns and a number of charts are available for recording this information. The degree of injury relates to the temperature and duration of exposure. Most domestic burns are mainly scalds in young children. Following the burn, there is a local response with progressive tissue loss and release of inflammatory cytokines. Systemically, there are cardiovascular effects resulting from fluid loss and sequestration of fluid into the third space. There is a marked catabolic response. Immunosuppression is common with large burns and bacterial translocation from the gut lumen is a recognised event. Sepsis is a common cause of death following major burns. Types of burn Type of burn Skin layers affected Skin appearance Blanching Management Epidermal/Superficial Epidermis Red, moist Yes Superficial partial thickness Epidermis and part of papillary dermis affected Pale, dry Yes Normally heals with no intervention Deep partial thickness Epidermis, whole papillary dermis affected Mottled red colour No Needs surgical intervention (depending on site) Full thickness Whole skin layer and subcutaneous tissue affected Dry, leathery hard wound No Burns centre Depth of burn assessment Bleeding on needle prick Sensation Appearance Blanching to pressure Percentage burn estimation Lund Browder chart: most accurate even in children Wallace rule of nines Palmar surface: surface area palm = 0.8% burn >15% body surface area burns in adults needs urgent burn fluid resuscitation Transfer to burn centre if: Need burn shock resuscitation Face/hands/genitals affected Deep partial thickness or full thickness burns Significant electrical/chemical burns Management The initial aim is to stop the burning process and resuscitate the patient. Intravenous fluids will be required for children with burns greater than 10% of total body surface area. Adults with burns greater than 15% of total body surface area will also require IV fluids. The fluids are calculated using the Parkland formula which is; volume of fluid= total body surface area of the burn % x weight (Kg) x2-4 (preference for lower amount i.e. 2ml to avoid excessive fluid overload). Half of the fluid is administered in the first 8 hours. A urinary catheter should be inserted. Analgesia should be given. Complex burns, burns involving the hand perineum and face and burns >10% in adults and >5% in children should be transferred to a burns unit. Circumferential burns affecting a limb or severe torso burns impeding respiration may require escharotomy to divide the burnt tissue. Conservative management is appropriate for superficial burns and mixed superficial burns that will heal in 2 weeks. More complex burns may require excision and skin grafting. Excision and primary closure is not generally practised as there is a high risk of infection. There is no evidence to support the use of anti microbial prophylaxis or topical antibiotics in burn patients. Escharotomies Indicated in circumferential full thickness burns to the torso or limbs. Careful division of the encasing band of burn tissue will potentially improve ventilation (if the burn involves the torso), or relieve compartment syndrome and oedema (where a limb is involved) References www.euroburn.org/e107files/downloads/guidelinesburncare.pdf Barajas-Nava LA, LÃ³pez-Alcalde J, RoquÃ© i Figuls M, SolÃ I, Bonfill Cosp X. Antibiotic prophylaxis for preventing burn wound infection. Cochrane Database of Systematic Reviews 2013, Issue 6. Art. No.: CD008738. DOI: 10.1002/14651858.CD008738.pub2. Hettiaratchy S & Papini R. Initial management of a major burn: assessment and resuscitation. BMJ 2004;329:101-103

Answer 1904

The presence of papillary structures together with the cytoplasmic features described is strongly suggestive of papillary carcinoma. They are seldom encapsulated. Thyroid neoplasms Lesion Common features Follicular adenoma Usually present as a solitary thyroid nodule Malignancy can only be excluded on formal histological assessment Papillary carcinoma Usually contain a mixture of papillary and colloidal filled follicles Histologically tumour has papillary projections and pale empty nuclei Seldom encapsulated Lymph node metastasis predominate Haematogenous metastasis rare Account for 60% of thyroid cancers Follicular carcinoma May appear macroscopically encapsulated, microscopically capsular invasion is seen. Without this finding the lesion is a follicular adenoma. Vascular invasion predominates Multifocal disease rare Account for 20% of all thyroid cancers Anaplastic carcinoma Most common in elderly females Local invasion is a common feature Account for 10% of thyroid cancers Treatment is by resection where possible, palliation may be achieved through isthmusectomy and radiotherapy. Chemotherapy is ineffective. Medullary carcinoma Tumours of the parafollicular cells (C Cells) C cells derived from neural crest and not thyroid tissue Serum calcitonin levels often raised Familial genetic disease accounts for up to 20% cases Both lymphatic and haematogenous metastasis are recognised, nodal disease is associated with a very poor prognosis.

Answer 1905

Cardiac output is lowered in hypovolaemia due to decreased preload. Pulmonary artery occlusion pressure monitoring The pulmonary artery occlusion pressure is an indirect measure of left atrial pressure, and thus filling pressure of the left heart. The low resistance within the pulmonary venous system allows this useful measurement to be made. The most accurate trace is made by inflating the balloon at the catheter tip and 'floating' it so that it occludes the vessel. If it is not possible to occlude the vessel in this way then the measurement gained will be the pulmonary artery end diastolic pressure. Interpretation of PAOP PAOP mmHg Scenario Normal 8-12 Low <5 Hypovolaemia Low with pulmonary oedema <5 ARDS High >18 Overload When combined with measurements of systemic vascular resistance and cardiac output it is possible to accurately classify patients. Systemic vascular resistance Derived from aortic pressure, right atrial pressure and cardiac output. SVR=80(mean aortic pressure-mean right atrial pressure)/cardiac output

Answer 1906

Amyloid is best assessed with a congo red stain. The tissues are positively birefringent under polarized light and typically stain green. Amyloid Amyloid is an extracellular protein deposit which is insoluble. These deposits disrupt normal tissue structure and if excessive may affect function. All types of amyloid consist of a major fibrillar protein that defines the type of amyloid (approximately 90%) plus various minor components. Amyloid is classified with the prefix A (for amyloid) and the suffix depending upon the fibrillary protein present. The main clinical types are AA and AL amyloidosis. Systemic AA amyloidosis is a long-term complication of several chronic inflammatory disorders - e.g. rheumatoid arthritis, ankylosing spondylitis, Crohn's disease, malignancies and conditions predisposing to recurrent infections. AL amyloidosis results from extra-cellular deposition of fibril-forming monoclonal immunoglobulin light chains (most commonly of lambda isotype). Most patients have evidence of isolated monoclonal gammopathy or asymptomatic myeloma, and the occurrence of AL amyloidosis in patients with symptomatic multiple myeloma or other B-cell lymphoproliferative disorders is unusual. AL type amyloidosis is the most common variant. The kidney and heart are two of the most commonly affected sites. Diagnosis is based on surgical biopsy and characteristic histological features which consist birefringence under polarised light. Immunohistochemistry is used to delineate the subtype. Treatment is usually targeted at the underlying cause.

Answer 1907

The positive predictive value (PPV) is the probability that an individual with a positive screening result has the disease. The sensitivity is the probability that an individual with the disease is screened positive and the specificity is the probability that an individual without the disease is screened negative. Its value depends upon the prevalence of the condition being tested for and the sensitivity of the test used. It may be calculated by dividing the number of true positives by the number of true positives and the number of false positives. Positive predictive values Screening tests Sensitivity: proportion of true positives identified by a test Specificity: proportion of true negatives correctly identified by a test Positive predictive value: proportion of those who have a positive test who actually have the disease Negative predictive value: proportion of those who test negative who do not have the disease Predictive values are dependent on the prevalence Likelihood ratio for a positive test result = sensitivity/(1-specificity) Likelihood ratio for a negative test result = (1-sensitivity)/specificity Likelihood ratios are not prevalence dependent

Answer 1908

Staphylococcus aureus is the commonest cause. The infants mouth is usually the source as it damages the nipple areolar complex allowing entry of bacteria. Breast abscess In lactational women Staphylococcus aureus is the most common cause Typical presentation is with a tender, fluctuant mass in a lactating women Diagnosis and treatment is performed using USS and associated drainage of the abscess cavity. Antibiotics should also be administered Where there is necrotic skin overlying the abscess, the patient should undergo surgery

Answer 1909

The commonest emergency in this age group is inguinal hernia followed by intussusception. Appendicitis is commoner in those older than 1 year of age. Paediatric Gastrointestinal disorders Pyloric stenosis M>F 5-10% Family history in parents Projectile non bile stained vomiting at 4-6 weeks of life Diagnosis is made by test feed or USS Treatment: Ramstedt pyloromyotomy (open or laparoscopic) Acute appendicitis Uncommon under 3 years When occurs may present atypically Mesenteric adenitis Central abdominal pain and URTI Conservative management Intussusception Telescoping bowel Proximal to or at the level of, ileocaecal valve 6-9 months age Colicky pain, diarrhoea and vomiting, sausage shaped mass, red jelly stool. Treatment: reduction with air insufflation Malrotation High caecum at the midline Feature in exomphalos, congenital diaphragmatic hernia, intrinsic duodenal atresia May be complicated by development of volvulus, infant with volvulus may have bile stained vomiting Diagnosis is made by upper GI contrast study and USS Treatment is by laparotomy, if volvulus is present (or at high risk of occurring then a ladds procedure is performed Hirschsprung's disease Absence of ganglion cells from myenteric and submucosal plexuses Occurs in 1/5000 births Full thickness rectal biopsy for diagnosis Delayed passage of meconium and abdominal distension Treatment is with rectal washouts initially, thereafter an anorectal pull through procedure Oesophageal atresia Associated with tracheo-oesophageal fistula and polyhydramnios May present with choking and cyanotic spells following aspiration VACTERL associations Meconium ileus Usually delayed passage of meconium and abdominal distension Majority have cystic fibrosis X-Rays may not show a fluid level as the meconium is viscid (depends upon feeding), PR contrast studies may dislodge meconium plugs and be therapeutic Infants who do not respond to PR contrast and NG N-acetyl cysteine will require surgery to remove the plugs Biliary atresia Jaundice > 14 days Increased conjugated bilirubin Urgent Kasai procedure Necrotising enterocolitis Prematurity is the main risk factor Early features include abdominal distension and passage of bloody stools X-Rays may show pneumatosis intestinalis and evidence of free air Increased risk when empirical antibiotics are given to infants beyond 5 days Treatment is with total gut rest and TPN, babies with perforations will require laparotomy

Answer 1910

Hypertrophic scars remain confined to the wound edges. Keloids (by definition) will tend to extend beyond the margins of the wound and in wounds of any depth. Wound healing Surgical wounds are either incisional or excisional and either clean, clean contaminated or dirty. Although the stages of wound healing are broadly similar their contributions will vary according to the wound type. The main stages of wound healing include: Haemostasis Minutes to hours following injury Vasospasm in adjacent vessels, platelet plug formation and generation of fibrin rich clot. Inflammation Typically days 1-5 Neutrophils migrate into wound (function impaired in diabetes). Growth factors released, including basic fibroblast growth factor and vascular endothelial growth factor. Fibroblasts replicate within the adjacent matrix and migrate into wound. Macrophages and fibroblasts couple matrix regeneration and clot substitution. Regeneration Typically days 7 to 56 Platelet derived growth factor and transformation growth factors stimulate fibroblasts and epithelial cells. Fibroblasts produce a collagen network. Angiogenesis occurs and wound resembles granulation tissue. Remodeling From 6 weeks to 1 year Longest phase of the healing process and may last up to one year (or longer). During this phase fibroblasts become differentiated (myofibroblasts) and these facilitate wound contraction. Collagen fibres are remodeled. Microvessels regress leaving a pale scar. The above description represents an idealised scenario. A number of diseases may distort this process. Neovascularisation is an important early process. Endothelial cells may proliferate in the wound bed and recanalise to form a vessel. Vascular disease, shock and sepsis can all compromise microvascular flow and impair healing. Conditions such as jaundice will impair fibroblast synthetic function and immunity with a detrimental effect in most parts of the healing process. Problems with scars: Hypertrophic scars Excessive amounts of collagen within a scar. Nodules may be present histologically containing randomly arranged fibrils within and parallel fibres on the surface. The tissue itself is confined to the extent of the wound itself and is usually the result of a full thickness dermal injury. They may go on to develop contractures. Image of hypertrophic scarring. Note that it remains confined to the boundaries of the original wound:

Answer 1911

Femoral hernia = High risk of strangulation (repair urgently) Femoral herniae account for <10% of all groin hernias. In the scenario the combination of symptoms of intestinal compromise with a mass in the region of the femoral canal points to femoral hernia as the most likely cause. Femoral canal The femoral canal lies at the medial aspect of the femoral sheath. The femoral sheath is a fascial tunnel containing both the femoral artery laterally and femoral vein medially. The canal lies medial to the vein. Borders of the femoral canal Laterally Femoral vein Medially Lacunar ligament Anteriorly Inguinal ligament Posteriorly Pectineal ligament Contents Lymphatic vessels Cloquet's lymph node Physiological significance Allows the femoral vein to expand to allow for increased venous return from the lower limbs. Pathological significance As a potential space, it is the site of femoral hernias. The relatively tight neck places these at high risk of strangulation.

Answer 1912

Right sided colonic cancers should proceed straight to surgery. Radiotherapy to this area is poorly tolerated and almost never offered as first line treatment. The decision as to whether or not chemotherapy is given is dependent upon the final histology. Colorectal cancer treatment Patients diagnosed as having colorectal cancer should be completely staged using CT of the chest/ abdomen and pelvis. Their entire colon should have been evaluated with colonoscopy or CT colonography. Patients whose tumours lie below the peritoneal reflection should have their mesorectum evaluated with MRI. Once their staging is complete patients should be discussed within a dedicated colorectal MDT meeting and a treatment plan formulated. Treatment of colonic cancer Cancer of the colon is nearly always treated with surgery. Stents, surgical bypass and diversion stomas may all be used as palliative adjuncts. Resectional surgery is the only option for cure in patients with colon cancer. The procedure is tailored to the patient and the tumour location. The lymphatic drainage of the colon follows the arterial supply and therefore most resections are tailored around the resection of particular lymphatic chains (e.g. ileo-colic pedicle for right sided tumours). Some patients may have confounding factors that will govern the choice of procedure, for example a tumour in a patient from a HNPCC family may be better served with a panproctocolectomy rather than segmental resection. Following resection the decision has to be made regarding restoration of continuity. For an anastomosis to heal the key technical factors include; adequate blood supply, mucosal apposition and no tissue tension. Surrounding sepsis, unstable patients and inexperienced surgeons may compromise these key principles and in such circumstances it may be safer to construct an end stoma rather than attempting an anastomosis. When a colonic cancer presents with an obstructing lesion; the options are to either stent it or resect. In modern practice it is unusual to simply defunction a colonic tumour with a proximal loop stoma. This differs from the situation in the rectum (see below). Following resection patients with risk factors for disease recurrence are usually offered chemotherapy, a combination of 5FU and oxaliplatin is common. Rectal cancer The management of rectal cancer is slightly different to that of colonic cancer. This reflects the rectum's anatomical location and the challenges posed as a result. Tumours located in the rectum can be surgically resected with either an anterior resection or an abdomino - perineal resection. The technical aspects governing the choice between these two procedures can be complex to appreciate and the main point to appreciate for the MRCS is that involvement of the sphincter complex or very low tumours require APER. In the rectum a 2cm distal clearance margin is required and this may also impact on the procedure chosen. In addition to excision of the rectal tube an integral part of the procedure is a meticulous dissection of the mesorectal fat and lymph nodes (total mesorectal excision/ TME). In rectal cancer surgery invovlement of the cirumferential resection margin carries a high risk of disease recurrence. Because the rectum is an extraperitoneal structure (until you remove it that is!) it is possible to irradiate it, something which cannot be offered for colonic tumours. This has a major impact in rectal cancer treatment and many patients will be offered neoadjuvent radiotherapy (both long and short course) prior to resectional surgery. Patients with T1, 2 and 3 /N0 disease on imaging do not require irradiation and should proceed straight to surgery. Patients with T4 disease will typically have long course chemo radiotherapy. Patients presenting with large bowel obstruction from rectal cancer should not undergo resectional surgery without staging as primary treatment (very different from colonic cancer). This is because rectal surgery is more technically demanding, the anastomotic leak rate is higher and the danger of a positive resection margin in an unstaged patient is high. Therefore patients with obstructing rectal cancer should have a defunctioning loop colostomy. Summary of procedures The operations for cancer are segmental resections based on blood supply and lymphatic drainage. These commonly performed procedures are core knowledge for the MRCS and should be understood. Site of cancer Type of resection Anastomosis Risk of leak Right colon Right hemicolectomy Ileo-colic Low <5% Transverse Extended right hemicolectomy Ileo-colic Low <5% Splenic flexure Extended right hemicolectomy Ileo-colic Low <5% Splenic flexure Left hemicolectomy Colo-colon 2-5% Left colon Left hemicolectomy Colo-colon 2-5% Sigmoid colon High anterior resection Colo-rectal 5% Upper rectum Anterior resection (TME) Colo-rectal 5% Low rectum Anterior resection (Low TME) Colo-rectal (+/- Defunctioning stoma) 10% Anal verge Abdomino-perineal excision of colon and rectum None n/a In the emergency setting, where the bowel has perforated, the risk of an anastomotic breakdown is much greater, particularly when the anastomosis is colon-colon. In this situation, an end colostomy is often safer and can be reversed later. When resection of the sigmoid colon is performed and an end colostomy is fashioned the operation is referred to as a Hartmans procedure. Whilst left sided resections are more risky, ileo-colic anastomoses are relatively safe even in the emergency setting and do not need to be defunctioned. References A review of the diagnosis and management of colorectal cancer and a summary of the UK National Institute of Clinical Excellence guidelines is provided in: NICE Guideline NG151. Last updated in 2020.

Answer 1913

As wounds mature the fibroblast population differentiates into myofibroblasts (usually 6 weeks and beyond), these have a contractile phenotype and therefore help in contracting the wound. Immature fibroblasts, though able to adhere to the ECM, do not have this ability. Wound healing Surgical wounds are either incisional or excisional and either clean, clean contaminated or dirty. Although the stages of wound healing are broadly similar their contributions will vary according to the wound type. The main stages of wound healing include: Haemostasis Minutes to hours following injury Vasospasm in adjacent vessels, platelet plug formation and generation of fibrin rich clot. Inflammation Typically days 1-5 Neutrophils migrate into wound (function impaired in diabetes). Growth factors released, including basic fibroblast growth factor and vascular endothelial growth factor. Fibroblasts replicate within the adjacent matrix and migrate into wound. Macrophages and fibroblasts couple matrix regeneration and clot substitution. Regeneration Typically days 7 to 56 Platelet derived growth factor and transformation growth factors stimulate fibroblasts and epithelial cells. Fibroblasts produce a collagen network. Angiogenesis occurs and wound resembles granulation tissue. Remodeling From 6 weeks to 1 year Longest phase of the healing process and may last up to one year (or longer). During this phase fibroblasts become differentiated (myofibroblasts) and these facilitate wound contraction. Collagen fibres are remodeled. Microvessels regress leaving a pale scar. The above description represents an idealised scenario. A number of diseases may distort this process. Neovascularisation is an important early process. Endothelial cells may proliferate in the wound bed and recanalise to form a vessel. Vascular disease, shock and sepsis can all compromise microvascular flow and impair healing. Conditions such as jaundice will impair fibroblast synthetic function and immunity with a detrimental effect in most parts of the healing process. Problems with scars: Hypertrophic scars Excessive amounts of collagen within a scar. Nodules may be present histologically containing randomly arranged fibrils within and parallel fibres on the surface. The tissue itself is confined to the extent of the wound itself and is usually the result of a full thickness dermal injury. They may go on to develop contractures. Image of hypertrophic scarring. Note that it remains confined to the boundaries of the original wound:

Answer 1914

The inguinal ligament is formed by the external oblique aponeurosis. It runs from the pubic tubercle to the anterior superior iliac spine. Abdominal wall The 2 main muscles of the abdominal wall are the rectus abdominis (anterior) and the quadratus lumborum (posterior). The remaining abdominal wall consists of 3 muscular layers. Each muscle passes from the lateral aspect of the quadratus lumborum posteriorly to the lateral margin of the rectus sheath anteriorly. Each layer is muscular posterolaterally and aponeurotic anteriorly. Muscles of abdominal wall External oblique Lies most superficially Originates from 5th to 12th ribs Inserts into the anterior half of the outer aspect of the iliac crest, linea alba and pubic tubercle More medially and superiorly to the arcuate line, the aponeurotic layer overlaps the rectus abdominis muscle The lower border forms the inguinal ligament The triangular expansion of the medial end of the inguinal ligament is the lacunar ligament. Internal oblique Arises from the thoracolumbar fascia, the anterior 2/3 of the iliac crest and the lateral 2/3 of the inguinal ligament The muscle sweeps upwards to insert into the cartilages of the lower 3 ribs The lower fibres form an aponeurosis that runs from the tenth costal cartilage to the body of the pubis At its lowermost aspect it joins the fibres of the aponeurosis of transversus abdominis to form the conjoint tendon. Transversus abdominis Innermost muscle Arises from the inner aspect of the costal cartilages of the lower 6 ribs , from the anterior 2/3 of the iliac crest and lateral 1/3 of the inguinal ligament Its fibres run horizontally around the abdominal wall ending in an aponeurosis. The upper part runs posterior to the rectus abdominis. Lower down the fibres run anteriorly only. The rectus abdominis lies medially; running from the pubic crest and symphysis to insert into the xiphoid process and 5th, 6th and 7th costal cartilages. The muscles lies in a aponeurosis as described above. Nerve supply: anterior primary rami of T7-12 Surgical notes During abdominal surgery it is usually necessary to divide either the muscles or their aponeuroses. During a midline laparotomy it is desirable to divide the aponeurosis. This will leave the rectus sheath intact above the arcuate line and the muscles intact below it. Straying off the midline will often lead to damage to the rectus muscles, particularly below the arcuate line where they may often be in close proximity to each other.

Answer 1915

TB reactivation most commonly occurs at the lung apex. This site is better oxygenated than elsewhere allowing the mycobacteria to multiply more rapidly and then spread both locally and distantly. Tuberculosis pathology Is a form of primary chronic inflammation, caused by the inability of macrophages to kill the Mycobacterium tuberculosis. The macrophages often migrate to regional lymph nodes, the lung lesion plus affected lymph nodes is referred to as a Ghon complex. This leads to the formation of a granuloma which is a collection of epithelioid histiocytes. There is the presence of caseous necrosis in the centre. The inflammatory response is mediated by a type 4 hypersensitivity reaction. In healthy individuals the disease may be contained, in the immunocompromised disseminated (miliary TB) may occur. Diagnosis Waxy membrane of mycobacteria prevents binding with normal stains. Ziehl - Neelsen staining is typically used. Culture based methods take far longer. Image showing acid- alcohol fast mycobacteria stained using the Ziehl- Neelsen method

Answer 1916

Most cases of malignant oesophageal obstruction can be managed by the placement of self expanding metal stents. The Celestin tube requires a laparotomy and is therefore obsolete. A resectional procedure would be inappropriate in the presence of liver metastasis. The main contra indication to metallic stent placement are very proximal tumours as it can be difficult to get proximal control in this situation and chemotherapy may be more appropriate. Treatment of oesophageal cancer - In general resections are not offered to those patients with distant metastasis, and usually not to those with N2 disease. Local nodal involvement is not in itself a contra indication to resection. Surgical resection is the mainstay of treatment. Neoadjuvent chemotherapy is given in most cases prior to surgery. In situ disease may be managed by endoscopic mucosal resection, although this is still debated. In patients with lower third lesions an Ivor - Lewis type procedure is most commonly performed. Very distal tumours may be suitable to a transhiatal procedure. Which is an attractive option as the penetration of two visceral cavities required for an Ivor- Lewis type procedure increases the morbidity considerably. More proximal lesions will require a total oesphagectomy (Mckeown type) with anastomosis to the cervical oesophagus. Patients with unresectable disease may derive benefit from local ablative procedures, palliative chemotherapy or stent insertion. Operative details of Ivor- Lewis procedure Combined laparotomy and right thoracotomy Indication Lower and middle third oesophageal tumours Preparation Staging with a combination of CT chest abdomen and pelvis- if no metastatic disease detected then patients will undergo a staging laparoscopy to detect peritoneal disease. If both these modalities are negative then patients will finally undergo a PET CT scan to detect occult metastatic disease. Only in those whom no evidence of advanced disease is detected will proceed to resection. Patients receive a GA, double lumen endotracheal tube to allow for lung deflation, CVP and arterial monitoring. Procedure A rooftop incision is made to access the stomach and duodenum. Laparotomy To mobilize the stomach The greater omentum is incised away from its attachment to the right gastroepiploic vessels along the greater curvature of the stomach. Then the short gastric vessels are ligated and detached from the greater curvature from the spleen. The lesser omentum is incised, preserving the right gastric artery. The retroperitoneal attachments of the duodenum in its second and third portions are incised, allowing the pylorus to reach the oesophageal hiatus. Some surgeons perform a pyloroplasty at this point to facilitate gastric emptying. The left gastric vessels are then ligated, avoiding any injury to the common hepatic or splenic arteries. Care must be taken to avoid inadvertently devascularising the liver owing to variations in anatomy. Right Thoracotomy Oesophageal resection and oesophagogastric anastomosis Through 5th intercostal space Dissection performed 10cm above the tumour This may involve transection of the azygos vein. The oesophagus is then removed with the stomach creating a gastric tube. An anastomosis is created. The chest is closed with underwater seal drainage and tube drains to the abdominal cavity. Post operatively Patients will typically recover in ITU initially. A nasogastric tube will have been inserted intraoperatively and must remain in place during the early phases of recovery. Post operatively these patients are at relatively high risk of developing complications: * Atelectasis- due to the effects of thoracotomy and lung collapse * Anastomotic leakage. The risk is relatively high owing to the presence of a relatively devascularised stomach. Often the only blood supply is from the gastroepiploic artery as all others will have been divided. If a leak does occur then many will attempt to manage conservatively with prolonged nasogastric tube drainage and TPN. The reality is that up to 50% of patients developing an anastomotic leak will not survive to discharge. * Delayed gastric emptying (may be avoided by performing a pyloroplasty).

Answer 1917

Warfarin affects synthesis of factors II, VII, IX, X and protein C. Warfarin Warfarin is an oral anticoagulant which inhibits the reduction of vitamin K to its active hydroquinone form, which in turn acts as a cofactor in the formation of clotting factor II, VII, IX and X (mnemonic = 1972) and protein C Factors that may potentiate warfarin Liver disease P450 enzyme inhibitors, e.g.: amiodarone, ciprofloxacin Cranberry juice Drugs which displace warfarin from plasma albumin, e.g. NSAIDs Inhibit platelet function: NSAIDs Side-effects Haemorrhage Teratogenic Skin necrosis: when warfarin is first started biosynthesis of protein C is reduced. This results in a temporary procoagulant state after initially starting warfarin, normally avoided by concurrent heparin administration. Thrombosis may occur in venules leading to skin necrosis.

Answer 1918

It is likely that this patient has an MEN I type gastrinoma (female, young age). As such, the serum gastrin levels are likely to be elevated. Zollinger - Ellison syndrome - Gastrin-secreting tumor (gastrinoma) of pancreas or duodenum. Acid hypersecretion causes recurrent ulcers in duodenum and jejunum. Presents with abdominal pain (peptic ulcer disease, distal ulcers), diarrhoea (malabsorption) 75% are sporadic and the 25% associated with MEN I Mean age of presentation is 50 years (earlier in MEN I) 60% are malignant They are typically found in the gastrinoma triangle. This is formed by the junction of cystic duct and CBD, junction of D2 and D3, junction of neck and body of pancreas. Imaging is with triple phase CT and endoscopic USS Serum sampling of serum gastrin levels will show these to be elevated. A secretin stimulation test is sometimes performed as gastrin levels will remain elevated following administration of secretin which usually suppresses gastrin. Treatment is with resection.

Answer 1919

Insulin should not be stopped in patients with type 1 diabetes and omission of more than one meal will usually require a variable rate insulin infusion Type 1 diabetics who take insulin should have this continued through the perioperative period. Fluid guidelines in diabetics differ and are not well covered in NPSA fluid guidelines. Preparation for surgery Elective and emergency patients require different preparation. Elective cases Consider pre admission clinic to address medical issues. Blood tests including FBC, U+E, LFT's, Clotting, Group and Save Urine analysis Pregnancy test Sickle cell test ECG/ Chest x-ray Exact tests to be performed will depend upon the proposed procedure and patient fitness. Risk factors for development of deep vein thrombosis should be assessed and a plan for thromboprophylaxis formulated. Diabetes Diabetic patients have greater risk of complications. Poorly controlled diabetes carries high risk of wound infections. Patients with diet or tablet controlled diabetes may be managed using a policy of omitting medication and checking blood glucose levels regularly. Diabetics who are poorly controlled or who take insulin may require a intravenous sliding scale. Potassium supplementation should also be given. Diabetic cases should be operated on first. Emergency cases Stabilise and resuscitate where needed. Consider whether antibiotics are needed and when and how they should be administered. Inform blood bank if major procedures planned particularly where coagulopathies are present at the outset or anticipated (e.g. Ruptured AAA repair) Don't forget to consent and inform relatives. Special preparation Some procedures require special preparation: Thyroid surgery; vocal cord check. Parathyroid surgery; consider methylene blue to identify gland. Sentinel node biopsy; radioactive marker/ patent blue dye. Surgery involving the thoracic duct; consider administration of cream. Pheochromocytoma surgery; will need alpha and beta blockade. Surgery for carcinoid tumours; will need covering with octreotide. Colorectal cases; bowel preparation (especially left sided surgery) Thyrotoxicosis; lugols iodine/ medical therapy. References Management of adults with diabetes undergoing surgery and elective procedures. NHS Diabetes. April 2011.

Answer 1920

Brain death Criteria for brain stem death testing Deep coma of known aetiology. Reversible causes excluded No sedation Normal electrolytes Testing for brain death Fixed pupils which do not respond to sharp changes in the intensity of incident light No corneal reflex Absent oculo-vestibular reflexes - no eye movements following the slow injection of at least 50ml of ice-cold water into each ear in turn (the caloric test) No response to supraorbital pressure No cough reflex to bronchial stimulation or gagging response to pharyngeal stimulation No observed respiratory effort in response to disconnection of the ventilator for long enough (typically 5 minutes) to ensure elevation of the arterial partial pressure of carbon dioxide to at least 6.0 kPa (6.5 kPa in patients with chronic carbon dioxide retention). Adequate oxygenation is ensured by pre-oxygenation and diffusion oxygenation during the disconnection (so the brain stem respiratory centre is not challenged by the ultimate, anoxic, drive stimulus) The test should be undertaken by two appropriately experienced doctors on two separate occasions. Both should be experienced in performing brain stem death testing and have at least 5 years post graduate experience. One of them must be a consultant. Neither can be a member of the transplant team (if organ donation contemplated).

Answer 1921

This is likely to be polycystic kidney disease as she has renal failure and family history of sub arachnoid haemorrhage. Haematuria Causes of haematuria Trauma Injury to renal tract Renal trauma commonly due to blunt injury (others penetrating injuries) Ureter trauma rare: iatrogenic Bladder trauma: due to RTA or pelvic fractures Infection Remember TB Malignancy Renal cell carcinoma (remember paraneoplastic syndromes): painful or painless Urothelial malignancies: 90% are transitional cell carcinoma, can occur anywhere along the urinary tract. Painless haematuria. Squamous cell carcinoma and adenocarcinoma: rare bladder tumours Prostate cancer Penile cancers: SCC Renal disease Glomerulonephritis Stones Microscopic haematuria common Structural abnormalities Benign prostatic hyperplasia (BPH) causes haematuria due to hypervascularity of the prostate gland Cystic renal lesions e.g. polycystic kidney disease Vascular malformations Renal vein thrombosis due to renal cell carcinoma Coagulopathy Causes bleeding of underlying lesions Drugs Cause tubular necrosis or interstitial nephritis: aminoglycosides, chemotherapy Interstitial nephritis: penicillin, sulphonamides, and NSAIDs Anticoagulants Benign Exercise Gynaecological Endometriosis: flank pain, dysuria, and haematuria that is cyclical Iatrogenic Catheterisation Radiotherapy; cystitis, severe haemorrhage, bladder necrosis Pseudohaematuria For example following consumption of beetroot References Http://bestpractice.bmj.com/best-practice/monograph/316/overview/aetiology.html

Answer 1922

This constellation of injuries is referred to as a Monteggia's fracture. Eponymous fractures Colles' fracture (dinner fork deformity) Fall onto extended outstretched hand Classical Colles' fractures have the following 3 features: 1. Transverse fracture of the radius 2. 1 inch proximal to the radio-carpal joint 3. Dorsal displacement and angulation Smith's fracture (reverse Colles' fracture) Volar angulation of distal radius fragment (Garden spade deformity) Caused by falling backwards onto the palm of an outstretched hand or falling with wrists flexed Bennett's fracture Intra-articular fracture of the first carpometacarpal joint Impact on flexed metacarpal, caused by fist fights X-ray: triangular fragment at ulnar base of metacarpal Monteggia's fracture Dislocation of the proximal radioulnar joint in association with an ulna fracture Fall on outstretched hand with forced pronation Needs prompt diagnosis to avoid disability Galeazzi fracture Radial shaft fracture with associated dislocation of the distal radioulnar joint Direct blow Pott's fracture Bimalleolar ankle fracture Forced foot eversion Barton's fracture Distal radius fracture (Colles'/Smith's) with associated radiocarpal dislocation Fall onto extended and pronated wrist Involvement of the joint is a defining feature Holstein Lewis Fracture A HolsteinLewis fracture is a fracture of the distal third of the humerus resulting in entrapment of the radial nerve. The radial nerve is one of the major nerves of the upper limb. It innervates all of the muscles in the extensor compartments of the arm. Conservative treatment includes reduction and use of a functional brace Vascular injury may require open surgery

Answer 1923

The SMA leaves the aorta approximately 1cm below the coeliac axis. This is usually a level of L1. It is crossed anteriorly by the splenic vein and the body of the pancreas. It runs downwards and forwards anterior to the uncinate process. Abdominal aortic branches Branches Level Paired Type Inferior phrenic T12 (Upper border) Yes Parietal Coeliac T12 No Visceral Superior mesenteric L1 No Visceral Middle suprarenal L1 Yes Visceral Renal L1-L2 Yes Visceral Gonadal L2 Yes Visceral Lumbar L1-L4 Yes Parietal Inferior mesenteric L3 No Visceral Median sacral L4 No Parietal Common iliac L4 Yes Terminal

Answer 1924

Tumour necrosis factor Tumour necrosis factor (TNF) is a pro-inflammatory cytokine with multiple roles in the immune system TNF is secreted mainly by macrophages and has a number of effects on the immune system, acting mainly in a paracrine fashion: activates macrophages and neutrophils acts as costimulator for T cell activation key mediator of body's response to Gram negative septicaemia similar properties to IL-1 anti-tumour effect (e.g. phospholipase activation) TNF-alpha binds to both the p55 and p75 receptor. These receptors can induce apoptosis. It also cause activation of NFkB Endothelial effects include increase expression of selectins and increased production of platelet activating factor, IL-1 and prostaglandins TNF promotes the proliferation of fibroblasts and their production of protease and collagenase. It is thought fragments of receptors act as binding points in serum Systemic effects include pyrexia, increased acute phase proteins and disordered metabolism leading to cachexia TNF is important in the pathogenesis of rheumatoid arthritis - TNF blockers (e.g. infliximab, etanercept) are now licensed for treatment of severe rheumatoid

Answer 1925

The significant burns will result in generalised loss of high molecular weight proteins thereby reducing the capillary oncotic pressure. As a result, the fluid is likely to remain in the interstitium and thereby cause oedema. Starlings forces About one sixth of the body consists of spaces between cells. The fluid within these spaces is termed interstitial fluid. This fluid is formed by filtration and diffusion from capillaries. It contains almost the same constituents as plasma with the exception of proteins as these are not filtered due to their high relative molecular mass. The pressure in the capillaries tends to force fluid and its dissolved substances through capillary pores and into this space. In contrast the osmotic pressure exerted by plasma proteins (colloid osmotic pressure) tends to favor movement from the interstitial spaces back into the vascular compartments (capillaries) themselves. The lymphatic system returns back to the circulation the small amounts of protein that do leak into the interstitium. There are four primary forces that determine fluid movement through a capillary membrane (Starlings forces): Capillary pressure - forces fluid out of the capillary Interstitial fluid pressure- which tends to force fluid inwards through the capillary membrane (when it is positive) Plasma colloid osmotic pressure- favors influx into the capillary Interstitial fluid osmotic pressure- favors efflux from the capillary into the interstitium

Answer 1926

The pudendal nerve innervates the posterior vulval area and is routinely blocked in procedures such as episiotomy. Pudendal nerve The pudendal nerve arises from nerve roots S2, S3 and S4 and exits the pelvis through the greater sciatic foramen. It re-enters the perineum through the lesser sciatic foramen. It travels inferior to give innervation to the anal sphincters and external urethral sphincter. It also provides cutaneous innervation to the region of perineum surrounding the anus and posterior vulva. Traction and compression of the pudendal nerve by the foetus in late pregnancy may result in late onset pudendal neuropathy which may be part of the process involved in the development of faecal incontinence.

Answer 1927

Inguinal hernia in infants = Urgent surgery The high incidence of strangulation necessitates an urgent herniotomy be performed. In infants with a reducible hernia this can be performed on a daycase list during the same week. Deferring surgery on the basis of age is not justified. Paediatric inguinal hernia Inguinal hernias are a common disorder in children. They are commoner in males as the testis migrates from its location on the posterior abdominal wall, down through the inguinal canal. A patent processus vaginalis may persist and be the site of subsequent hernia development. Children presenting in the first few months of life are at the highest risk of strangulation and the hernia should be repaired urgently. Children over 1 year of age are at lower risk and surgery may be performed electively. For paediatric hernias a herniotomy without implantation of mesh is sufficient. Most cases are performed as day cases, neonates and premature infants are kept in hospital overnight as there is a recognised increased risk of post operative apnoea.

Answer 1928

Rifampicin, phenytoin, levodopa, methyldopa, and quinine all cause pseudohaematuria. Haematuria Causes of haematuria Trauma Injury to renal tract Renal trauma commonly due to blunt injury (others penetrating injuries) Ureter trauma rare: iatrogenic Bladder trauma: due to RTA or pelvic fractures Infection Remember TB Malignancy Renal cell carcinoma (remember paraneoplastic syndromes): painful or painless Urothelial malignancies: 90% are transitional cell carcinoma, can occur anywhere along the urinary tract. Painless haematuria. Squamous cell carcinoma and adenocarcinoma: rare bladder tumours Prostate cancer Penile cancers: SCC Renal disease Glomerulonephritis Stones Microscopic haematuria common Structural abnormalities Benign prostatic hyperplasia (BPH) causes haematuria due to hypervascularity of the prostate gland Cystic renal lesions e.g. polycystic kidney disease Vascular malformations Renal vein thrombosis due to renal cell carcinoma Coagulopathy Causes bleeding of underlying lesions Drugs Cause tubular necrosis or interstitial nephritis: aminoglycosides, chemotherapy Interstitial nephritis: penicillin, sulphonamides, and NSAIDs Anticoagulants Benign Exercise Gynaecological Endometriosis: flank pain, dysuria, and haematuria that is cyclical Iatrogenic Catheterisation Radiotherapy; cystitis, severe haemorrhage, bladder necrosis Pseudohaematuria For example following consumption of beetroot References Http://bestpractice.bmj.com/best-practice/monograph/316/overview/aetiology.html

Answer 1929

As sudden infant death syndrome is relatively rare a case-control design is more appropriate than a cohort study. Study design The following table highlights the main features of the main types of study: Randomised controlled trial Participants randomly allocated to intervention or control group (e.g. standard treatment or placebo) Practical or ethical problems may limit use Cohort study Observational and prospective. Two (or more) are selected according to their exposure to a particular agent (e.g. medicine, toxin) and followed up to see how many develop a disease or other outcome. The usual outcome measure is the relative risk. Examples include Framingham Heart Study Case-control study Observational and retrospective. Patients with a particular condition (cases) are identified and matched with controls. Data is then collected on past exposure to a possible causal agent for the condition. The usual outcome measure is the odds ratio. Inexpensive, produce quick results Useful for studying rare conditions Prone to confounding Cross-sectional survey Provide a 'snapshot', sometimes called prevalence studies Provide weak evidence of cause and effect

Answer 1930

This is critical limb ischaemia. Values of 0.3 are typical in this setting and urgent further imaging is needed. Debridement of necrosis prior to improving arterial inflow carries a high risk of limb loss. Ankle-Brachial pressure index Measurement of ankle- brachial pressure index (ABPI) is a commonly performed vascular investigation. Calculated by dividing lower limb pressure by the highest upper limb pressure. Results of ABPI 1.2 or greater Usually due to vessel calcification 1.0- 1.2 Normal 0.8-1.0 Minor stenotic lesion Initiate risk factor management 0.50-0.8 Moderate stenotic lesion Consider duplex Risk factor management If mixed ulcers present then avoid tight compression bandages 0.3 - 0.5 Likely significant stenosis Duplex scanning to delineate lesions needed Compression bandaging contra indicated Less than 0.3 Indicative of critical ischaemia Urgent detailed imaging required

Answer 1931

The external jugular vein runs obliquely in the superficial fascia of the posterior triangle. It drains into the subclavian vein. During surgical exploration of this area the external jugular vein may be injured and troublesome bleeding may result. The internal jugular vein and carotid arteries are located in the anterior triangle. The third, and not the second, part of the subclavian artery is also a content of the posterior triangle Posterior triangle of the neck Boundaries Apex Sternocleidomastoid and the Trapezius muscles at the Occipital bone Anterior Posterior border of the Sternocleidomastoid Posterior Anterior border of the Trapezius Base Middle third of the clavicle Contents Nerves Accessory nerve Phrenic nerve Three trunks of the brachial plexus Branches of the cervical plexus: Supraclavicular nerve, transverse cervical nerve, great auricular nerve, lesser occipital nerve Vessels External jugular vein Subclavian artery Muscles Inferior belly of omohyoid Scalene Lymph nodes Supraclavicular Occipital

Answer 1932

Diverticular disease is one of the commonest causes of colovesical fistula Recurrent attacks of diverticulitis may cause the development of local abscesses which may erode into the bladder resulting in urinary sepsis and pneumaturia. This would be an unusual presentation from Crohns disease and rectal cancer would be more distally sited and generally evidence of extra colonic disease would be present if the case were malignant and this advanced. Diverticular disease Diverticular disease is a common surgical problem. It consists of herniation of colonic mucosa through the muscular wall of the colon. The usual site is between the taenia coli where vessels pierce the muscle to supply the mucosa. For this reason, the rectum, which lacks taenia, is often spared. Symptoms Altered bowel habit Bleeding Abdominal pain Complications Diverticulitis Haemorrhage Development of fistula Perforation and faecal peritonitis Perforation and development of abscess Development of diverticular phlegmon Diagnosis Patients presenting in clinic will typically undergo either a colonoscopy, CT cologram or barium enema as part of their diagnostic work up. All tests can identify diverticular disease. It can be far more difficult to confidently exclude cancer, particularly in diverticular strictures. Acutely unwell surgical patients should be investigated in a systematic way. Plain abdominal films and an erect chest x-ray will identify perforation. An abdominal CT scan (not a CT cologram) with oral and intravenous contrast will help to identify whether acute inflammation is present but also the presence of local complications such as abscess formation. Severity Classification- Hinchey I Para-colonic abscess II Pelvic abscess III Purulent peritonitis IV Faecal peritonitis Treatment Increase dietary fibre intake. Mild attacks of diverticulitis may be managed conservatively with antibiotics. Peri colonic abscesses should be drained either surgically or radiologically. Recurrent episodes of acute diverticulitis requiring hospitalisation are a relative indication for a segmental resection. Hinchey IV perforations (generalised faecal peritonitis) will require a resection and usually a stoma. This group have a very high risk of post operative complications and usually require HDU admission.

Answer 1933

Exomphalos and diaphragmatic herniae are commonly associated with malrotation. Intestinal malrotation in neonates Normal embryology During the fourth week of embryogenesis the intestine moves into the abdomen via the base of the umbilicus. Through a combination of foetal growth and bowel maturation the bowel resides in the abdominal cavity and undergoes a 270o counterclockwise twist. At the conclusion of this process the ligament of Treitz lies to the left of the spine and the caecum in the right lower quadrant. Malrotation occurs when the rotational process described is incomplete. Typically the duodenal loop lies to the left of the caecum and therefore lacks 90 o of its 270o rotation. It becomes fixed in this position with peritoneal attachments (Ladds bands). Symptoms Bilious vomiting is the cardinal symptom and sign. In most cases there are no antecedent symptoms. If untreated then gut perfusion may be impaired with resultant development of further symptoms. Diagnosis The main problem is that the infant develops mid gut volvulus. In this situation the bowel undergoes a 720o twist, the bowel viability depends upon a narrow mesentery containing the superior mesenteric artery. To ascertain whether this has occurred the two main tests include an abdominal ultrasound scan to determine the relationship between the superior mesenteric artery and vein (normally SMA lies to the left of the SMV). This test is complemented with an upper GI contrast series and this aims to establish that the DJ flexure is correctly sited to the left of the vertebral bodies. Treatment Laparotomy and division of adhesional bands (Ladds procedure). The division of the congenital adhesions allows widening of the small bowel mesentery. The bowel is untwisted and assessed for viability. The bowel is returned to the abdominal cavity in the non rotated fashion with the small bowel on the right hand side and the large bowel on the left, the caecum is positioned in the left upper quadrant. Because the caecum is located in this new location many surgeons will also perform an appendicectomy due to the diagnostic difficulty posed in diagnosing appendicitis in this group of patients.

Answer 1934

The issue here is an interplay between sepsis and thyroid disease. A degree of rate control is required to facilitate anaesthesia and this is best achieved with beta blockade in this particular setting. Hyperthyroidism Causes of hyperthyroidism include: Diffuse toxic goitre (Graves Disease) Toxic nodular goitre Toxic nodule Rare causes Graves disease Graves disease is characterised by a diffuse vascular goitre that appears at the same time as the clinical manifestations of hyperthyroidism. It is commonest in younger females and may be associated with eye signs. Thyrotoxic symptoms will predominate. Up to 50% of patients will have a familial history of autoimmune disorders. The glandular hypertrophy and hyperplasia occur as a result of the thyroid stimulating effects of the TSH receptor antibodies. Toxic nodular goitre In this disorder the goitre is present for a long period of time prior to the development of clinical symptoms. In most goitres the nodules are inactive and in some cases it is the internodular tissue that is responsible for the hyperthyroidism. Toxic nodule Overactive, autonomously functioning nodule. It may occur as part of generalised nodularity or be a true toxic adenoma. The TSH levels are usually low as the autonomously functioning thyroid tissue will exert a negative feedback effect. Signs and symptoms Symptoms Signs Lethargy Tachycardia Emotionally labile Agitation Heat intolerance Hot, moist palms Weight loss Exopthalmos Excessive appetite Thyroid goitre and bruit Palpitations Lid lag/retraction Diagnosis The most sensitive test for diagnosing hyperthyroidism is plasma T3 (which is raised). Note in hypothyroidism the plasma T4 and TSH are the most sensitive tests. A TSH level of <0.5U/L suggests hyperthyroidism. TSH receptor antibodies may be tested for in the diagnosis of Graves. Treatment First line treatment for Graves disease is usually medical and the block and replace regime is the favored option. Carbimazole is administered at higher doses and thyroxine is administered orally. Patients are maintained on this regime for between 6 and 12 months. Attempts are then made to wean off medication. Where relapse then occurs the options are between ongoing medical therapy, radioiodine or surgery.

Answer 1935

An 'anti insulin' effect occurs leading to hyperglycaemia. Stress response: Endocrine and metabolic changes - Surgery precipitates hormonal and metabolic changes causing the stress response. Stress response is associated with: substrate mobilization, muscle protein loss, sodium and water retention, suppression of anabolic hormone secretion, activation of the sympathetic nervous system, immunological and haematological changes. The hypothalamic-pituitary axis and the sympathetic nervous systems are activated and there is a failure of the normal feedback mechanisms of control of hormone secretion. A summary of the hormonal changes associated with the stress response: Increased Decreased No Change Growth hormone Insulin Thyroid stimulating hormone Cortisol Testosterone Luteinizing hormone Renin Oestrogen Follicle stimulating hormone Adrenocorticotrophic hormone (ACTH) Aldosterone Prolactin Antidiuretic hormone Glucagon Sympathetic nervous system Stimulates catecholamine release Causes tachycardia and hypertension Pituitary gland ACTH and growth hormone (GH) is stimulated by hypothalamic releasing factors, corticotrophin releasing factor (CRF) and somatotrophin (or growth hormone releasing factor) Perioperative increased prolactin secretion occurs by release of inhibitory control Secretion of thyroid stimulating hormone (TSH), luteinizing hormone (LH) and follicle stimulating hormone (FSH) does not change significantly ACTH stimulates cortisol production within a few minutes of the start of surgery. More ACTH is produced than needed to produce a maximum adrenocortical response. Cortisol Significant increases within 4-6 hours of surgery (>1000 nmol litre-1). The usual negative feedback mechanism fails and concentrations of ACTH and cortisol remain persistently increased. The magnitude and duration of the increase correlate with the severity of stress and the response is not abolished by the administration of corticosteroids. The metabolic effects of cortisol are enhanced: Skeletal muscle protein breakdown to provide gluconeogenic precursors and amino acids for protein synthesis in the liver Stimulation of lipolysis 'Anti-insulin effect' Mineralocorticoid effects Anti-inflammatory effects Growth hormone Increased secretion after surgery has a minor role Most important for preventing muscle protein breakdown and promote tissue repair by insulin growth factors Alpha Endorphin Increased Antidiuretic hormone An important vasopressor and enhances haemostasis Renin is released causing the conversion of angiotensinogen to angiotensin I Angiotensin II formed by ACE on angiotensin 1, which causes the secretion of aldosterone from the adrenal cortex. This increases sodium reabsorption at the distal convoluted tubule Insulin Release inhibited by stress Occurs via the inhibition of the beta cells in the pancreas by the α2-adrenergic inhibitory effects of catecholamines Insulin resistance by target cells occurs later The perioperative period is characterized by a state of functional insulin deficiency Thyroxine (T4) and tri-iodothyronine (T3) Circulating concentrations are inversely correlated with sympathetic activity and after surgery there is a reduction in thyroid hormone production, which normalises over a few days. Metabolic effect of endocrine response Carbohydrate metabolism Hyperglycaemia is a main feature of the metabolic response to surgery Due to increase in glucose production and a reduction in glucose utilization Catecholamines and cortisol promote glycogenolysis and gluconeogenesis Initial failure of insulin secretion followed by insulin resistance affects the normal responses The proportion of the hyperglycaemic response reflects the severity of surgery Hyperglycaemia impairs wound healing and increase infection rates Protein metabolism Initially there is inhibition of protein anabolism, followed later, if the stress response is severe, by enhanced catabolism The amount of protein degradation is influenced by the type of surgery and also by the nutritional status of the patient Mainly skeletal muscle protein is affected The amino acids released form acute phase proteins (fibrinogen, C reactive protein, complement proteins, a2-macroglobulin, amyloid A and ceruloplasmin) and are used for gluconeogenesis Nutritional support has little effect on preventing catabolism Lipid metabolism Increased catecholamine, cortisol and glucagon secretion, and insulin deficiency, promotes lipolysis and ketone body production. Salt and water metabolism ADH causes water retention, concentrated urine, and potassium loss and may continue for 3 to 5 days after surgery Renin causes sodium and water retention Cytokines Glycoproteins Interleukins (IL) 1 to 17, interferons, and tumour necrosis factor Synthesized by activated macrophages, fibroblasts, endothelial and glial cells in response to tissue injury from surgery or trauma IL-6 main cytokine associated with surgery. Peak 12 to 24 h after surgery and increase by the degree of tissue damage Other effects of cytokines include fever, granulocytosis, haemostasis, tissue damage limitation and promotion of healing. Modifying the response Opioids suppress hypothalamic and pituitary hormone secretion At high doses the hormonal response to pelvic and abdominal surgery is abolished. However, such doses prolong recovery and increase the need for postoperative ventilatory support Spinal anaesthesia can reduce the glucose, ACTH, cortisol, GH and epinephrine changes, although cytokine responses are unaltered Cytokine release is reduced in less invasive surgery Nutrition prevents the adverse effects of the stress response. Enteral feeding improves recovery Growth hormone and anabolic steroids may improve outcome Normothermia decreases the metabolic response References Vasiliki Manou-Stathopoulou et al. Redefining the perioperative stress response: a narrative review. Br J Anaesth. 2019 Nov;123(5):570-583. Deborah Burton, Grainne Nicholson, and George Hall Endocrine and metabolic response to surgery . Contin Educ Anaesth Crit Care Pain (2004) 4(5): 144-147 doi:10.1093/bjaceaccp/mkh040

Answer 1936

Torsades de pointes: Treatment IV magnesium sulphate This woman is likely to have hypokalaemia and hypomagnasaemia as a result of vomiting. In addition to this, the erythromycin will predispose her to torsades de pointes. The patient needs Magnesium 2g over 10 minutes. Knowledge of the management of this peri arrest diagnosis is hence important in surgical practice. Torsades de pointes Torsades de pointes ('twisting of the points') is a rare arrhythmia associated with a long QT interval. It may deteriorate into ventricular fibrillation and hence lead to sudden death Causes of long QT interval congenital: Jervell-Lange-Nielsen syndrome, Romano-Ward syndrome antiarrhythmics: amiodarone, sotalol, class 1a antiarrhythmic drugs tricyclic antidepressants antipsychotics chloroquine terfenadine erythromycin electrolyte: hypocalcaemia, hypokalaemia, hypomagnesaemia myocarditis hypothermia subarachnoid haemorrhage Management IV magnesium sulphate

Answer 1937

Types of joint There are three main types of joint, fibrous, cartilaginous and synovial Type of joint Features Example Fibrous Comprise sutures, gomphoses and syndesmoses Tough connective tissues unite the joints Sutures- skull Gomphoses-Peg to socket e.g. teeth Syndesmosis-tibiofibular joint Cartilaginous Joints united by layer of hyaline cartilage Epiphyseal growth plates Symphysis pubis Synovial joints Bone ends permitted free movement Bone ends covered by cartilage and surrounded by fluid

Answer 1938

The proximal part of the sixth right pharyngeal arch gives origin to the right pulmonary artery. The distal part gives origin to the left pulmonary artery and the ductus arteriosus. Pharyngeal arches These develop during the fourth week of embryonic growth from a series of mesodermal outpouchings of the developing pharynx. They develop and fuse in the ventral midline. Pharyngeal pouches form on the endodermal side between the arches. There are 6 pharyngeal arches, the fifth does not contribute any useful structures and often fuses with the sixth arch. Pharyngeal arches Pharyngeal arch Muscular contributions Skeletal contributions Endocrine Artery Nerve First Muscles of mastication Anterior belly of digastric Mylohyoid Tensor tympanic Tensor veli palatini Maxilla Meckels cartilage Incus Malleus n/a Maxillary External carotid Mandibular Second Buccinator Platysma Muscles of facial expression Stylohyoid Posterior belly of digastric Stapedius Stapes Styloid process Lesser horn and upper body of hyoid n/a Inferior branch of superior thyroid artery Stapedial artery Facial Third Stylopharyngeus Greater horn and lower part of hyoid Thymus Inferior parathyroids Common and internal carotid Glossopharyngeal Fourth Cricothyroid All intrinsic muscles of the soft palate Thyroid and epiglottic cartilages Superior parathyroids Right- subclavian artery, Left-aortic arch Vagus Sixth All intrinsic muscles of the larynx (except cricothyroid) Cricoid, arytenoid and corniculate cartilages n/a Right -Pulmonary artery, Left- Pulmonary artery and ductus arteriosus Vagus and recurrent laryngeal nerve

Answer 1939

Venous ulcers are usually associated with features of venous insufficiency. These include haemosiderin deposition and varicose veins. Neuropathic ulcers will tend to present at sites of pressure, which is not typically at the medial malleolus. Lower leg ulcers Venous leg ulcers Most due to venous hypertension, secondary to chronic venous insufficiency (other causes include calf pump dysfunction or neuromuscular disorders) Ulcers form due to capillary fibrin cuff or leucocyte sequestration Features of venous insufficiency include oedema, brown pigmentation, lipodermatosclerosis, eczema Location above the ankle, painless Deep venous insufficiency is related to previous DVT and superficial venous insufficiency is associated with varicose veins Doppler ultrasound looks for presence of reflux and duplex ultrasound looks at the anatomy/ flow of the vein Management: 4 layer compression banding after exclusion of arterial disease or surgery If fail to heal after 12 weeks or >10cm2 skin grafting may be needed

Answer 1940

Gardner's syndrome is an AD disorder, characterised by: Colonic polyps, supernumerary teeth, jaw osteomas, congenital hypertrophy of retinal pigment. osteomas of the skull, thyroid cancer, epidermoid cysts, fibromas and sebaceous cysts. Genetics and surgical disease Some of the more commonly occurring genetic conditions occurring in surgical patients are presented here. Li-Fraumeni Syndrome Autosomal dominant Consists of germline mutations to p53 tumour suppressor gene High incidence of malignancies particularly sarcomas and leukaemias Diagnosed when: *Individual develops sarcoma under 45 years *First degree relative diagnosed with any cancer below age 45 years and another family member develops malignancy under 45 years or sarcoma at any age BRCA 1 and 2 Carried on chromosome 17 (BRCA 1) and Chromosome 13 (BRCA 2) Linked to developing breast cancer (60%) risk. Associated risk of developing ovarian cancer (55% with BRCA 1 and 25% with BRCA 2). Lynch Syndrome Autosomal dominant Develop colonic cancer and endometrial cancer at young age 80% of affected individuals will get colonic and/ or endometrial cancer High risk individuals may be identified using the Amsterdam criteria Amsterdam criteria Three or more family members with a confirmed diagnosis of colorectal cancer, one of whom is a first degree (parent, child, sibling) relative of the other two. Two successive affected generations. One or more colon cancers diagnosed under age 50 years. Familial adenomatous polyposis (FAP) has been excluded. Gardners syndrome Autosomal dominant familial colorectal polyposis Multiple colonic polyps Extra colonic diseases include: skull osteoma, thyroid cancer and epidermoid cysts Desmoid tumours are seen in 15% Mutation of APC gene located on chromosome 5 Due to colonic polyps most patients will undergo colectomy to reduce risk of colorectal cancer Now considered a variant of familial adenomatous polyposis coli

Answer 1941

The intermediate portion of the deltoid muscle is the chief abductor of the humerus. However, it can only do this after the movement has been initiated by supraspinatus. Damage to the tendon of supraspinatus is a common form of rotator cuff disease. Shoulder joint Shallow synovial ball and socket type of joint. It is an inherently unstable joint, but is capable to a wide range of movement. Stability is provided by muscles of the rotator cuff that pass from the scapula to insert in the greater tuberosity (all except sub scapularis-lesser tuberosity). Glenoid labrum Fibrocartilaginous rim attached to the free edge of the glenoid cavity Tendon of the long head of biceps arises from within the joint from the supraglenoid tubercle, and is fused at this point to the labrum. The long head of triceps attaches to the infraglenoid tubercle Fibrous capsule Attaches to the scapula external to the glenoid labrum and to the labrum itself (postero-superiorly) Attaches to the humerus at the level of the anatomical neck superiorly and the surgical neck inferiorly Anteriorly the capsule is in contact with the tendon of subscapularis, superiorly with the supraspinatus tendon, and posteriorly with the tendons of infraspinatus and teres minor. All these blend with the capsule towards their insertion. Two defects in the fibrous capsule; superiorly for the tendon of biceps. Anteriorly there is a defect beneath the subscapularis tendon. The inferior extension of the capsule is closely related to the axillary nerve at the surgical neck and this nerve is at risk in anteroinferior dislocations. It also means that proximally sited osteomyelitis may progress to septic arthritis. Movements and muscles Flexion Anterior part of deltoid Pectoralis major Biceps Coracobrachialis Extension Posterior deltoid Teres major Latissimus dorsi Adduction Pectoralis major Latissimus dorsi Teres major Coracobrachialis Abduction Mid deltoid Supraspinatus Medial rotation Subscapularis Anterior deltoid Teres major Latissimus dorsi Lateral rotation Posterior deltoid Infraspinatus Teres minor Important anatomical relations Anteriorly Brachial plexus Axillary artery and vein Posterior Suprascapular nerve Suprascapular vessels Inferior Axillary nerve Circumflex humeral vessels

Answer 1942

In a young patient with local disease only a radical prostatectomy is the best chance of cure. Radiotherapy may be given instead but has long term sequelae (and inferior survival outcomes). A transvesical prostatectomy is a largely historical operation performed for BPH before TURP was established. Prostate Cancer Prostate Cancer This is a common condition and up to 30,000 men are diagnosed with the condition each year. Up to 9,000 will die in in the UK from the condition per year. Diagnosis Early prostate cancers have few symptoms. Metastatic disease may present as bone pain. Locally advanced disease may present as pelvic pain or with urinary symptoms. Prostate specific antigen measurement Digital rectal examination Trans rectal USS (+/- biopsy) MRI/ CT and bone scan for staging. PSA Test The normal upper limit for PSA is 4ng/ml. However, in this group will lie patients with benign disease and some with localised prostate cancer. False positives may be due to prostatitis, UTI, BPH, vigorous DRE. The percentage of free: total PSA may help to distinguish benign disease from cancer. Values of <20% are suggestive of cancer and biopsy is advised. Pathology 95% adenocarcinoma In situ malignancy is sometimes found in areas adjacent to cancer. Multiple biopsies needed to call true in situ disease. Often multifocal- 70% lie in the peripheral zone. Graded using the Gleason grading system, two grades awarded 1 for most dominant grade (on scale of 1-5) and 2 for second most dominant grade (scale 1-5). The two added together give the Gleason score. Where 2 is best prognosis and 10 the worst. Lymphatic spread occurs first to the obturator nodes and local extra prostatic spread to the seminal vesicles is associated with distant disease. Treatment Watch and wait- Elderly, multiple co-morbidities, low Gleason score Radiotherapy (External)- Both potentially curative and palliative therapy possible. However, radiation proctitis and rectal malignancy are late problems. Brachytherapy is a modification allowing internal radiotherapy. Surgery- Radical prostatectomy. Surgical removal of the prostate is the standard treatment for localised disease. The robot is being used increasingly for this procedure. As well as the prostate the obturator nodes are also removed to complement the staging process. Erectile dysfunction is a common side effect. Survival may be better than with radiotherapy (see references). Functional outcomes are better when a robotic approach is used. Hormonal therapy- Testosterone stimulates prostate tissue and prostatic cancers usually show some degree of testosterone dependence. 95% of testosterone is derived from the testis and bilateral orchidectomy may be used for this reason. Pharmacological alternatives include LHRH analogues and anti androgens (which may be given in combination). In the UK the National Institute for Clinical Excellence (NICE) suggests that active surveillance is the preferred option for low risk men. It is particularly suitable for men with clinical stage T1c, Gleason score 3+3 and PSA density < 0.15 ng/ml/ml who have cancer in less than 50% of their biopsy cores, with < 10 mm of any core involved. Candidates for active surveillance should: have had at least 10 biopsy cores taken have at least one re-biopsy. If men on active surveillance show evidence of disease progression, offer radical treatment. Treatment decisions should be made with the man, taking into account co-morbidities and life expectancy. References 1. Prostate cancer pathway. NICE. NG131 last updated December 2021. 2. Sooriakumaran P et al. Comparative effectiveness of radical prostatectomy and radiotherapy in prostate cancer: observational study of mortality outcomes. BMJ 2014 (348):13. This study shows that in men with localised disease survival was greater in those offered surgery.

Answer 1943

Cystic hygromas are soft and transilluminate. Most are located in the posterior triangle. Neck Masses in Children Thyroglossal cyst Located in the anterior triangle, usually in the midline and below the hyoid (65% cases) Derived from remnants of the thyroglossal duct Thin walled and anechoic on USS (echogenicity suggests infection of cyst) Branchial cyst Six branchial arches separated by branchial clefts Incomplete obliteration of the branchial apparatus may result in cysts, sinuses or fistulae 75% of branchial cysts originate from the second branchial cleft Usually located anterior to the sternocleidomastoid near the angle of the mandible Unless infected the fluid of the cyst has a similar consistency to water and is anechoic on USS Dermoids Derived from pleuripotent stem cells and are located in the midline Most commonly in a suprahyoid location They have heterogeneous appearances on imaging and contain variable amounts of calcium and fat Thyroid gland True thyroid lesions are rare in children and usually represent thyroglossal cysts or tumours like lymphoma Lymphatic malformations Usually located posterior to the sternocleidomastoid Cystic hygroma result from occlusion of lymphatic channels The painless, fluid filled, lesions usually present prior to the age of 2 They are often closely linked to surrounding structures and surgical removal is difficult They are typically hypoechoic on USS Infantile haemangioma May present in either triangle of the neck Grow rapidly initially and then will often spontaneously regress Plain x-rays will show a mass lesion, usually containing calcified phleboliths As involution occurs the fat content of the lesions increases Lymphadenopathy Located in either triangle of the neck May be reactive or neoplastic Generalised lymphadenopathy usually secondary to infection in children (very common)

Answer 1944

Slipped upper femoral epiphysis is the commonest adolescent hip disorder. It occurs most commonly in obese males. It may often present as knee pain which is usually referred from the ipsilateral hip. The knee itself is normal. The hip often limits internal rotation. The diagnosis is easily missed. X-rays will show displacement of the femoral epiphysis and the degree of its displacement may be calculated using the Southwick angle. Treatment is directed at preventing further slippage which may result in avascular necrosis of the femoral head. Paediatric orthopaedics Diagnosis Mode of presentation Treatment Radiology Developmental dysplasia of the hip Usually diagnosed in infancy by screening tests. May be bilateral, when disease is unilateral there may be leg length inequality. As disease progresses child may limp and then early onset arthritis. More common in extended breech babies. Splints and harnesses or traction. In later years osteotomy and hip realignment procedures may be needed. In arthritis a joint replacement may be needed. However, this is best deferred if possible as it will almost certainly require revision Initially no obvious change on plain films and USS gives best resolution until 3 months of age. On plain films Shentons line should form a smooth arc Perthes Disease Hip pain (may be referred to the knee) usually occurring between 5 and 12 years of age. Bilateral disease in 20%. Remove pressure from joint to allow normal development. Physiotherapy. Usually self-limiting if diagnosed and treated promptly. X-rays will show flattened femoral head. Eventually in untreated cases the femoral head will fragment. Slipped upper femoral epiphysis Typically seen in obese male adolescents. Pain is often referred to the knee. Limitation to internal rotation is usually seen. Knee pain is usually present 2 months prior to hip slipping. Bilateral in 20%. Bed rest and non-weight bearing. Aim to avoid avascular necrosis. If severe slippage or risk of it occurring then percutaneous pinning of the hip may be required. X-rays will show the femoral head displaced and falling inferolaterally (like a melting ice cream cone) The Southwick angle gives indication of disease severity

Answer 1945

Scalp wounds often bleed and the addition of adrenaline is therefore desirable. Lignocaine is fast acting and the preferred agent. Local anaesthetic agents Lidocaine An amide Local anaesthetic and a less commonly used antiarrhythmic (affects Na channels in the axon) Hepatic metabolism, protein bound, renally excreted Toxicity: due to IV or excess administration. Increased risk if liver dysfunction or low protein states. Note acidosis causes lidocaine to detach from protein binding. Drug interactions: Beta blockers, ciprofloxacin, phenytoin Features of toxicity: Initial CNS over activity then depression as lidocaine initially blocks inhibitory pathways then blocks both inhibitory and activating pathways. Cardiac arrhythmias. Increased doses may be used when combined with adrenaline to limit systemic absorption. Cocaine Pure cocaine is a salt, usually cocaine hydrochloride. It is supplied for local anaesthetic purposes as a paste. It is supplied for clinical use in concentrations of 4 and 10%. It may be applied topically to the nasal mucosa. It has a rapid onset of action and has the additional advantage of causing marked vasoconstriction. It is lipophillic and will readily cross the blood brain barrier. Its systemic effects also include cardiac arrhythmias and tachycardia. Apart from its limited use in ENT surgery it is otherwise used rarely in mainstream surgical practice. Bupivacaine Bupivacaine binds to the intracellular portion of sodium channels and blocks sodium influx into nerve cells, which prevents depolarization. It has a much longer duration of action than lignocaine and this is of use in that it may be used for topical wound infiltration at the conclusion of surgical procedures with long duration analgesic effect. It is cardiotoxic and is therefore contra indicated in regional blockage in case the tourniquet fails. Levobupivacaine (Chirocaine) is less cardiotoxic and causes less vasodilation. Prilocaine Similar mechanism of action to other local anaesthetic agents. However, it is far less cardiotoxic and is therefore the agent of choice for intravenous regional anaesthesia e.g. Biers Block. All local anaesthetic agents dissociate in tissues and this contributes to their therapeutic effect. The dissociation constant shifts in tissues that are acidic e.g. where an abscess is present, and this reduces the efficacy. Doses of local anaesthetics Agent Dose plain Dose with adrenaline Lignocaine 3mg/Kg 7mg/Kg Bupivacaine 2mg/Kg 2mg/Kg Prilocaine 6mg/Kg 9mg/Kg These are a guide only as actual doses depend on site of administration, tissue vascularity and co-morbidities. Maximum total local anaesthetic doses Lignocaine 1% plain - 3mg/ Kg - 200mg (20ml) Lignocaine 1% with 1 in 200,000 adrenaline - 7mg/Kg - 500mg (50ml) Bupivacaine 0.5% - 2mg/kg- 150mg (30ml) Maximum doses are based on ideal body weight Effects of adrenaline Adrenaline may be added to local anaesthetic drugs. It prolongs the duration of action at the site of injection and permits usage of higher doses (see above). It is contra indicated in patients taking MAOI's or tricyclic antidepressants. The toxicity of bupivacaine is related to protein binding and addition of adrenaline to this drug does not permit increases in the total dose of bupivacaine, in contrast to the situation with lignocaine. References An excellent review is provided by: French J and Sharp L. Local Anaesthetics. Ann R Coll Surg Engl 2012; 94: 76-80.

Answer 1946

Hypertension in a young patient without any obvious cause should be investigated. Urinary VMA and plasma metanephrines are typically elevated. Phaeochromocytoma and adrenal lesions Phaeochromocytoma Neuroendocrine tumour of the chromaffin cells of the adrenal medulla. Hypertension and hyperglycaemia are often found. 10% of cases are bilateral. 10% occur in children. 11% are malignant (higher when tumour is located outside the adrenal). 10% will not be hypertensive. Familial cases are usually linked to the Multiple endocrine neoplasia syndromes (considered under its own heading). Most tumours are unilateral (often right sided) and smaller than 10cm. Diagnosis Urine and plasma metanephrine levels. CT and MRI scanning are both used to localise the lesion. Treatment Patients require medical therapy first. An irreversible alpha adrenoreceptor blocker should be given, although minority may prefer reversible blockade(1). Labetolol may be co-administered for cardiac chronotropic control. Isolated beta blockade should not be considered as it will lead to unopposed alpha activity. These patients are often volume depleted and will often require moderate volumes of intra venous normal saline perioperatively. Once medically optimised the phaeochromocytoma should be removed. Most adrenalectomies can now be performed using a laparoscopic approach(2). The adrenals are highly vascular structures and removal can be complicated by catastrophic haemorrhage in the hands of the inexperienced. This is particularly true of right sided resections where the IVC is perilously close. Should the IVC be damaged a laparotomy will be necessary and the defect enclosed within a Satinsky style vascular clamp and the defect closed with prolene sutures. Attempting to interfere with the IVC using any instruments other than vascular clamps will result in vessel trauma and make a bad situation much worse. Incidental adrenal lesions Adrenal lesions may be identified on CT scanning performed for other reasons(3). Factors suggesting benign disease on CT include(4): Size less than 3cm Homogeneous texture Lipid rich tissue Thin wall to lesion All patients with incidental lesions should be managed jointly with an endocrinologist and full work up as described above. Patients with functioning lesions or those with adverse radiological features (Particularly size >3cm) should proceed to surgery. References 1. Weingarten TN, Cata JP, O'Hara JF, Prybilla DJ, Pike TL, Thompson GB, et al. Comparison of two preoperative medical management strategies for laparoscopic resection of pheochromocytoma. Urology. 2010 Aug;76(2):508 e6-11. 2. Nguyen PH, Keller JE, Novitsky YW, Heniford BT, Kercher KW. Laparoscopic approach to adrenalectomy: review of perioperative outcomes in a single center. Am Surg. 2011 May;77(5):592-6. 3. Ng VW, Ma RC, So WY, Choi KC, Kong AP, Cockram CS, et al. Evaluation of functional and malignant adrenal incidentalomas. Arch Intern Med. 2010 Dec 13;170(22):2017-20. 4. Muth A, Hammarstedt L, Hellstrom M, Sigurjonsdottir HA, Almqvist E, Wangberg B. Cohort study of patients with adrenal lesions discovered incidentally. Br J Surg. 2011 May 27.

Answer 1947

The hypoglossal nerve supplies motor innervation to all extrinsic and intrinsic muscles of the tongue. The only possible exception to this is palatoglossus, which is innervated by the vagus. Cranial nerves Cranial nerve lesions Olfactory nerve May be injured in basal skull fractures or involved in frontal lobe tumour extension. Loss of olfactory nerve function in relation to major CNS pathology is seldom an isolated event and thus it is poor localiser of CNS pathology. Optic nerve Problems with visual acuity may result from intra ocular disorders. Problems with the blood supply such as amaurosis fugax may produce temporary visual distortion. More important surgically is the pupillary response to light. The pupillary size may be altered in a number of disorders. Nerves involved in the resizing of the pupil connect to the pretectal nucleus of the high midbrain, bypassing the lateral geniculate nucleus and the primary visual cortex. From the pretectal nucleus neurones pass to the Edinger - Westphal nucleus, motor axons from here pass along with the oculomotor nerve. They synapse with ciliary ganglion neurones; the parasympathetic axons from this then innervate the iris and produce miosis. The miotic pupil is seen in disorders such as Horner's syndrome or opiate overdose. Mydriasis is the dilatation of the pupil in response to disease, trauma, drugs (or the dark!). It is pathological when light fails to induce miosis. The radial muscle is innervated by the sympathetic nervous system. Because the parasympathetic fibres travel with the oculomotor nerve they will be damaged by lesions affecting this nerve (e.g. cranial trauma). The response to light shone in one eye is usually a constriction of both pupils. This indicates intact direct and consensual light reflexes. When the optic nerve has an afferent defect the light shining on the affected eye will produce a diminished pupillary response in both eyes. Whereas light shone on the unaffected eye will produce a normal pupillary response in both eyes. This is referred to as the Marcus Gunn pupil and is seen in conditions such as optic neuritis. In a total CN II lesion shining the light in the affected eye will produce no response. Oculomotor nerve The pupillary effects are described above. In addition it supplies all ocular muscles apart from lateral rectus and superior oblique. Thus the affected eye will be deviated inferolaterally. Levator palpebrae superioris may also be impaired resulting in impaired ability to open the eye. Trochlear nerve The eye will not be able to look down. Trigeminal nerve Largest cranial nerve. Exits the brainstem at the pons. Branches are ophthalmic, maxillary and mandibular. Only the mandibular branch has both sensory and motor fibres. Branches converge to form the trigeminal ganglion (located in Meckels cave). It supplies the muscles of mastication and also tensor veli palatine, mylohyoid, anterior belly of digastric and tensor tympani. The detailed descriptions of the various sensory functions are described in other areas of the website. The corneal reflex is important and is elicited by applying a small tip of cotton wool to the cornea, a reflex blink should occur if it is intact. It is mediated by: the naso ciliary branch of the ophthalmic branch of the trigeminal (sensory component) and the facial nerve producing the motor response. Lesions of the afferent arc will produce bilateral absent blink and lesions of the efferent arc will result in a unilateral absent blink. Abducens nerve The affected eye will have a deficit of abduction. This cranial nerve exits the brainstem between the pons and medulla. It thus has a relatively long intra cranial course which renders it susceptible to damage in raised intra cranial pressure. Facial nerve Emerges from brainstem between pons and medulla. It controls muscles of facial expression and taste from the anterior 2/3 of the tongue. The nerve passes into the petrous temporal bone and into the internal auditory meatus. It then passes through the facial canal and exits at the stylomastoid foramen. It passes through the parotid gland and divides at this point. It does not innervate the parotid gland. Its divisions are considered in other parts of the website. Its motor fibres innervate orbicularis oculi to produce the efferent arm of the corneal reflex. In surgical practice it may be injured during parotid gland surgery or invaded by malignancies of the gland and a lower motor neurone on the ipsilateral side will result. Vestibulo-cochlear nerve Exits from the pons and then passes through the internal auditory meatus. It is implicated in sensorineural hearing loss. Individuals with sensorineural hearing loss will localise the sound in webers test to the normal ear. Rinnes test will be reduced on the affected side but should still work. These two tests will distinguish sensorineural hearing loss from conductive deafness. In the latter condition webers test will localise to the affected ear and Rinnes test will be impaired on the affected side. Surgical lesions affecting this nerve include CNS tumours and basal skull fractures. It may also be damaged by the administration of ototoxic drugs (of which gentamicin is the most commonly used in surgical practice). Glossopharyngeal nerve Exits the pons just above the vagus. Receives sensory fibres from posterior 1/3 tongue, tonsils, pharynx and middle ear (otalgia may occur following tonsillectomy). It receives visceral afferents from the carotid bodies. It supplies parasympathetic fibres to the parotid gland via the otic ganglion and motor function to stylopharyngeaus muscle. The sensory function of the nerve is tested using the gag reflex. Vagus nerve Leaves the medulla between the olivary nucleus and the inferior cerebellar peduncle. Passes through the jugular foramen and into the carotid sheath. Details of the functions of the vagus nerve are covered in the website under relevant organ sub headings. Accessory nerve Exists from the caudal aspect of the brainstem (multiple branches) supplies trapezius and sternocleidomastoid muscles. The distal portion of this nerve is most prone to injury during surgical procedures. Hypoglossal nerve Emerges from the medulla at the preolivary sulcus, passes through the hypoglossal canal. It lies on the carotid sheath and passes deep to the posterior belly of digastric to supply muscles of the tongue (except palatoglossus). Its location near the carotid sheath makes it vulnerable during carotid endarterectomy surgery and damage will produce ipsilateral defect in muscle function.

Answer 1948

The median nerve supplies cutaneous sensation to this region. Median nerve The median nerve is formed by the union of a lateral and medial root respectively from the lateral (C5,6,7) and medial (C8 and T1) cords of the brachial plexus; the medial root passes anterior to the third part of the axillary artery. The nerve descends lateral to the brachial artery, crosses to its medial side (usually passing anterior to the artery). It passes deep to the bicipital aponeurosis and the median cubital vein at the elbow. It passes between the two heads of the pronator teres muscle, and runs on the deep surface of flexor digitorum superficialis (within its fascial sheath). Near the wrist it becomes superficial between the tendons of flexor digitorum superficialis and flexor carpi radialis, deep to palmaris longus tendon. It passes deep to the flexor retinaculum to enter the palm, but lies anterior to the long flexor tendons within the carpal tunnel. Branches Region Branch Upper arm No branches, although the nerve commonly communicates with the musculocutaneous nerve Forearm Pronator teres Pronator quadratus Flexor carpi radialis Palmaris longus Flexor digitorum superficialis Flexor pollicis longus Flexor digitorum profundus (only the radial half) Distal forearm Palmar cutaneous branch Hand (Motor) Motor supply (LOAF) Lateral 2 lumbricals Opponens pollicis Abductor pollicis brevis Flexor pollicis brevis Hand (Sensory) Over thumb and lateral 2 Â½ fingers On the palmar aspect this projects proximally, on the dorsal aspect only the distal regions are innervated with the radial nerve providing the more proximal cutaneous innervation. Patterns of damage Damage at wrist e.g. carpal tunnel syndrome paralysis and wasting of thenar eminence muscles and opponens pollicis (ape hand deformity) sensory loss to palmar aspect of lateral (radial) 2 Â½ fingers Damage at elbow, as above plus: unable to pronate forearm weak wrist flexion ulnar deviation of wrist Anterior interosseous nerve (branch of median nerve) leaves just below the elbow results in loss of pronation of forearm and weakness of long flexors of thumb and index finger

Answer 1949

The accessory nerve lies in the posterior triangle and may be injured in this region. Apart from problems with shrugging the shoulder, he may also have difficulty lifting his arm above his head. Posterior triangle of the neck Boundaries Apex Sternocleidomastoid and the Trapezius muscles at the Occipital bone Anterior Posterior border of the Sternocleidomastoid Posterior Anterior border of the Trapezius Base Middle third of the clavicle Contents Nerves Accessory nerve Phrenic nerve Three trunks of the brachial plexus Branches of the cervical plexus: Supraclavicular nerve, transverse cervical nerve, great auricular nerve, lesser occipital nerve Vessels External jugular vein Subclavian artery Muscles Inferior belly of omohyoid Scalene Lymph nodes Supraclavicular Occipital

Answer 1950

Inguinal canal walls: 'MALT: 2M, 2A, 2L, 2T': Starting from superior, moving around in order to posterior: Superior wall (roof): 2 Muscles:Internal oblique, transversus abdominis Anterior wall: 2 Aponeuroses: Aponeurosis of external oblique, Aponeurosis of internal oblique Lower wall (floor): 2 Ligaments: Inguinal Ligament, Lacunar Ligament Posterior wall: 2Ts: Transversalis fascia, Conjoint Tendon This is actually quite a straightforward question. It is simply asking for the structure that forms the posterior wall of the inguinal canal. This is composed of the transversalis fascia, the conjoint tendon and more laterally the deep inguinal ring.

Answer 1951

Ankle swelling is often absent. If present it may be due to mixed arteriovenous disease. With mixed disease the arterial component is treated first. Peripheral vascular disease Indications for surgery to revascularise the lower limb Intermittent claudication Critical ischaemia Ulceration Gangrene Intermittent claudication that is not disabling may provide a relative indication, whilst the other complaints are often absolute indications depending upon the frailty of the patient. Assessment Clinical examination Ankle brachial pressure index measurement Duplex arterial ultrasound Angiography (standard, CT or MRI): usually performed only if intervention being considered. Angioplasty In order for angioplasty to be undertaken successfully the artery has to be accessible. The lesion relatively short and reasonable distal vessel runoff. Longer lesions may be amenable to sub-intimal angioplasty. Surgery Surgery will be undertaken where attempts at angioplasty have either failed or are unsuitable. Bypass essentially involves bypassing the affected arterial segment by utilising a graft to run from above the disease to below the disease. As with angioplasty good runoff improves the outcome. Some key concepts with bypass surgery Superficial femoral artery occlusion to the above knee popliteal In the ideal scenario, vein (either in situ or reversed LSV) would be used as a conduit. However, prosthetic material has reasonable 5 year patency rates and some would advocate using this in preference to vein so that vein can be used for other procedures in the future. In general terms either technique is usually associated with an excellent outcome (if run off satisfactory). Procedure Artery dissected out, IV heparin 3,000 units given and then the vessels are cross clamped Longitudinal arteriotomy Graft cut to size and tunneled to arteriotomy sites Anastomosis to femoral artery usually with 5/0 'double ended' Prolene suture Distal anastomosis usually using 6/0 'double ended' Prolene Distal disease Femoro-distal bypass surgery takes longer to perform, is more technically challenging and has higher failure rates. In elderly diabetic patients with poor runoff a primary amputation may well be a safer and more effective option. There is no point in embarking on this type of surgery in patients who are wheelchair bound. In femorodistal bypasses vein gives superior outcomes to PTFE. Rules Vein mapping 1st to see whether there is suitable vein (the preferred conduit). Sub intimal hyperplasia occurs early when PTFE is used for the distal anastomosis and will lead to early graft occlusion and failure. Essential operative procedure as for above knee fem-pop. If there is insufficient vein for the entire conduit then vein can be attached to the end of the PTFE graft and then used for the distal anastomosis. This type of 'vein boot' is technically referred to as a Miller Cuff and is associated with better patency rates than PTFE alone. Remember the more distal the arterial anastomosis the lower the success rate. References Peach G et al. Diagnosis and management of peripheral arterial disease. BMJ 2012; 345: 36-41.

Answer 1952

H-Pylori has a number of pathological effects. In this question the main issue is by what mechanism the organism is able to induce both gastric and duodenal ulceration. Without modestly elevated acid levels, the duodenum would not undergo gastric metaplasia. H-Pylori cannot colonise duodenal mucosa and therefore the development of ulcers at this site can only occur in those who have undergone metaplastic transformation (mediated by increased acidity). Helicobacter Pylori Infection with Helicobacter Pylori is implicated in many cases of duodenal ulceration and up to 60% of patients with gastric ulceration. It is a gram negative, helical shaped rod with microaerophillic requirements. It has the ability to produce a urease enzyme that will hydrolyse urea resulting in the production of ammonia. The effect of ammonia on antral G cells is to cause release of gastrin via a negative feedback loop. Once infection is established the organism releases enzymes that disrupt the gastric mucous layer. Certain subtypes release cytotoxins cag A and vac A gene products. The organism incites a classical chronic inflammatory process of the gastric epithelium. This accounts for the development of gastric ulcers. The mildly increased acidity may induce a process of duodenal gastric metaplasia. Whilst duodenal mucosa cannot be colonised by H-Pylori, mucosa that has undergone metaplastic change to the gastric epithelial type may be colonised by H- Pylori with subsequent inflammation and development of duodenitis and ulcers. In patients who are colonized, there is a 10-20% risk of peptic ulcer, 1-2% risk gastric cancer and <1% risk MALT lymphoma.

Answer 1953

Menisci have no nerve or blood supply and thus heal poorly. Established tears with associated symptoms are best managed by arthroscopic menisectomy. Knee injury Types of injury Ruptured anterior cruciate ligament Sport injury Mechanism: high twisting force applied to a bent knee Typically presents with: loud crack, pain and RAPID joint swelling (haemoarthrosis) Poor healing Management: intense physiotherapy or surgery Ruptured posterior cruciate ligament Mechanism: hyperextension injuries Tibia lies back on the femur Paradoxical anterior draw test Rupture of medial collateral ligament Mechanism: leg forced into valgus via force outside the leg Knee unstable when put into valgus position Menisceal tear Rotational sporting injuries Delayed knee swelling Joint locking (Patient may develop skills to 'unlock' the knee Recurrent episodes of pain and effusions are common, often following minor trauma Chondromalacia patellae Teenage girls, following an injury to knee e.g. Dislocation patella Typical history of pain on going downstairs or at rest Tenderness, quadriceps wasting Dislocation of the patella Most commonly occurs as a traumatic primary event, either through direct trauma or through severe contraction of quadriceps with knee stretched in valgus and external rotation Genu valgum, tibial torsion and high riding patella are risk factors Skyline x-ray views of patella are required, although displaced patella may be clinically obvious An osteochondral fracture is present in 5% The condition has a 20% recurrence rate Fractured patella 2 types: i. Direct blow to patella causing undisplaced fragments ii. Avulsion fracture Tibial plateau fracture Occur in the elderly (or following significant trauma in young) Mechanism: knee forced into valgus or varus, but the knee fractures before the ligaments rupture Varus injury affects medial plateau and if valgus injury, lateral plateau depressed fracture occurs Classified using the Schatzker system (see below) Schatzker Classification system for tibial plateau fractures Type Anatomical description Features 1 Vertical split of lateral condyle Fracture through dense bone, usually in the young. It may be virtually undisplaced, or the condylar fragment may be pushed inferiorly and tilted 2 Vertical split of the lateral condyle combined with an adjacent load bearing part of the condyle The wedge fragment (which may be of variable size), is displaced laterally; the joint is widened. Untreated, a valgus deformity may develop 3 Depression of the articular surface with intact condylar rim The split does not extend to the edge of the plateau. Depressed fragments may be firmly embedded in subchondral bone, the joint is stable 4 Fragment of the medial tibial condyle Two injuries are seen in this category; (1) a depressed fracture of osteoporotic bone in the elderly. (2) a high energy fracture resulting in a condylar split that runs from the intercondylar eminence to the medial cortex. Associated ligamentous injury may be severe 5 Fracture of both condyles Both condyles fractured but the column of the metaphysis remains in continuity with the tibial shaft 6 Combined condylar and subcondylar fractures High energy fracture with marked comminution

Answer 1954

Clostridium difficile can spread rapidly on surgical wards. The use of broad spectrum prophylactic antibiotics during arthroplasty surgery can increase the risk. Surgical Microbiology An extensive topic so an overview is given here. Organisms causing common surgical infections are reasonable topics in the examination. However, microbiology is less rigorously tested than anatomy, for example. Common organisms Staphylococcus aureus Facultative anaerobe Gram positive coccus Haemolysis on blood agar plates Catalase positive 20% population are long term carriers Exo and entero toxin may result in toxic shock syndrome and gastroenteritis respectively Ideally treated with penicillin although many strains now resistant through beta Lactamase production. In the UK less than 5% of isolates are sensitive to penicillin. Resistance to methicillin (and other antibiotics) is mediated by the mec operon , essentially penicillin binding protein is altered and resistance to this class of antibiotics ensues Common cause of cutaneous infections and abscesses Streptococcus pyogenes Gram positive, forms chain like colonies, Lancefield Group A Streptococcus Produces beta haemolysis on blood agar plates Rarely part of normal skin microflora Catalase negative Releases a number of proteins/ virulence factors into host including hyaluronidase, streptokinase which allow rapid tissue destruction Releases superantigens such as pyogenic exotoxin A which results in scarlet fever Remains sensitive to penicillin, macrolides may be used as an alternative. Escherichia coli Gram negative rod Facultative anaerobe, non sporing Wide range of subtypes and some are normal gut commensals Some subtypes such as 0157 may produce lethal toxins resulting in haemolytic-uraemic syndrome Enterotoxigenic E-Coli produces an enterotoxin (ST enterotoxin) that results in large volume fluid secretion into the gut lumen (Via cGMP activation) Enteropathogenic E-Coli binds to intestinal cells and cause structural damage, this coupled with a moderate (or in case of enteroinvasive E-Coli significant) invasive component produces enteritis and large volume diarrhoea together with fever. They are resistant to many antibiotics used to treat gram positive infections and acquire resistance rapidly and are recognised as producing beta lactamases Campylobacter jejuni Curved, gram negative, non sporulating bacteria One of the commonest causes of diarrhoea worldwide Produces enteritis which is often diffuse and blood may be passed Remains a differential for right iliac fossa pain with diarrhoea Self limiting infection so antibiotics are not usually advised. However, the quinolones are often rapidly effective. Helicobacter pylori Gram negative, helix shaped rod, microaerophillic Produces hydrogenase that can derive energy from hydrogen released by intestinal bacteria Flagellated and mobile Those carrying the cag A gene may cause ulcers It secretes urease that breaks down gastric urea> Carbon dioxide and ammonia> ammonium>bicarbonate (simplified!) The bicarbonate can neutralise the gastric acid. Usually colonises the gastric antrum and irritates resulting in increased gastrin release and higher levels of gastric acid. These patients will develop duodenal ulcers. In those with more diffuse H-Pylori infection gastric acid levels are lower and ulcers develop by local tissue damage from H-Pylori- these patients get gastric ulcers. Diagnosis may be made by serology (approx. 75% sensitive). Biopsy urease test during endoscopy probably the most sensitive. In patients who are colonised 10-20% risk of peptic ulcer, 1-2% risk gastric cancer, <1% risk MALT lymphoma.

Answer 1955

Portacaths are a good choice for children as they only need to be accessed when they are used. Broviacs would pose the same core problems as a Hickman. Intravenous access Venous access A number of routes for establishing venous access are available. Peripheral venous cannula Easy to insert with minimal morbidity. Wide lumen cannulae can provide rapid fluid infusions. When properly managed infections may be promptly identified and the cannula easily re sited. Problems relate to their peripheral sites and they are unsuitable for the administration of vaso active drugs, such as inotropes and irritant drugs such as TPN (except in the very short term setting). Central lines Insertion is more difficult and most operators and NICE advocate the use of ultra sound. Coagulopathies may lead to haemorrhage following iatrogenic arterial injury. Femoral lines are easier to insert and iatrogenic injuries easier to manage in this site however they are prone to high infection rates. Internal jugular route is preferred. They have multiple lumens allowing for administration of multiple infusions. The lumens are relatively narrow and thus they do not allow particularly rapid rates of infusion. Intraosseous access This is typically undertaken at the anteromedial aspect of the proximal tibia and provides access to the marrow cavity and circulatory system. Although traditionally preferred in paediatric practice they may be used in adults and a wide range of fluids can be infused using these devices. Tunneled lines Tunneled lines such as Groshong and Hickman lines are popular devices for patients with long term therapeutic requirements. These devices are usually inserted using ultrasound guidance into the internal jugular vein and then tunneled under the skin. A cuff of woven material is sited near the end and helps to anchor the device into the tissues. These cuffs require formal dissection to allow the device to be removed. Tunneled lines can be linked to injection ports that are located under the skin. These are especially popular in paediatric practice. Peripherally inserted central cannula Referred to as PICC lines, these are popular methods for establishing central venous access. Because they are inserted peripherally they are less prone to major complications relating to device insertion than conventional central lines.

Answer 1956

When part of the bowel wall is trapped in a hernia such as this it is termed a Richters hernia and may complicate any hernia although femoral and obturator hernias are most typically implicated. Hernia Hernias occur when a viscus or part of it protrudes from within its normal anatomical cavity. Specific hernias are covered under their designated titles the remainder are addressed here. Spigelian hernia Interparietal hernia occurring at the level of the arcuate line Rare May lie beneath internal oblique muscle. Usually between internal and external oblique Equal sex distribution Position is lateral to rectus abdominis Both open and laparoscopic repair are possible, the former in cases of strangulation Lumbar hernia The lumbar triangle (through which these may occur) is bounded by: Crest of ilium (inferiorly) External oblique (laterally) Latissimus dorsi (medially) Primary lumbar herniae are rare, most are incisional hernias following renal surgery - Direct anatomical repair with or without mesh re-enforcement is the procedure of choice Obturator hernia Herniation through the obturator canal Commoner in females Usually lies behind pectineus muscle Elective diagnosis is unusual most will present acutely with obstruction When presenting acutely most cases with require laparotomy or laparoscopy (and small bowel resection if indicated) Richters hernia Condition in which part of the wall of the small bowel (usually the anti mesenteric border) is strangulated within a hernia (of any type) They do not present with typical features of intestinal obstruction as lumenal patency is preserved Where vomiting is prominent it usually occurs as a result of paralytic ileus from peritonitis (as these hernias may perforate) Incisional hernia Occur through sites of surgical access into the abdominal cavity Most common following surgical wound infection To minimise following midline laparotomy Jenkins Rule should be followed and this necessitates a suture length 4x length of incision with bites taken at 1cm intervals, 1 cm from the wound edge Repair may be performed either at open surgery or laparoscopically and a wide variety of techniques are described Bochdalek hernia Typically congenital diaphragmatic hernia 85% cases are located in the left hemi diaphragm Associated with lung hypoplasia on the affected side More common in males Associated with other birth defects May contain stomach May be treated by direct anatomical apposition or placement of mesh. In infants that have severe respiratory compromise mechanical ventilation may be needed and mortality rate is high Morgagni Hernia Rare type of diaphragmatic hernia (approx 2% cases) Herniation through foramen of Morgagni Usually located on the right and tend to be less symptomatic More advanced cases may contain transverse colon As defects are small pulmonary hypoplasia is less common Direct anatomical repair is performed Umbilical hernia Hernia through weak umbilicus Usually presents in childhood Often symptomatic Equal sex incidence 95% will resolve by the age of 2 years Surgery performed after the third birthday Paraumbilical hernia Usually a condition of adulthood Defect is in the linea alba More common in females Multiparity and obesity are risk factors Traditionally repaired using Mayos technique - overlapping repair, mesh may be used though not if small bowel resection is required owing to acute strangulation Littres hernia Hernia containing Meckels diverticulum Resection of the diverticulum is usually required and this will preclude a mesh repair

Answer 1957

Ilioinguinal nerve entrapment may be a cause of neuropathic pain following inguinal hernia surgery. The ilioinguinal nerve passes through the superfical inguinal ring and is routinely encountered when exploring the inguinal canal during hernia surgery. The iliohypogastric nerve pierces the aponeurosis of the external oblique muscle superior to the superficial inguinal ring. Ilioinguinal nerve Arises from the first lumbar ventral ramus with the iliohypogastric nerve. It passes inferolaterally through the substance of psoas major and over the anterior surface of quadratus lumborum. It pierces the internal oblique muscle and passes deep to the aponeurosis of the external oblique muscle. It enters the inguinal canal and then passes through the superficial inguinal ring to reach the skin. Branches To supply those muscles of the abdominal wall through which it passes. Skin and fascia over the pubic symphysis, superomedial part of the femoral triangle, surface of the scrotum, root and dorsum of penis or labium majus in females.

Answer 1958

Aspirin 300mg should be given as soon as possible. If the patient has a moderate to high risk of myocardial infarction, then Clopidogrel should be given with a low molecular weight heparin. Thromboloysis or urgent percutaneous intervention should be given if there are significant ECG changes. Management of acute coronary syndrome NICE produced guidelines in 2020 on the management of unstable angina and non-ST elevation myocardial infarction (NSTEMI). They advocate managing patients based on the early risk assessment using a recognised scoring system such as GRACE (Global Registry of Acute Cardiac Events) to calculate a predicted 6 month mortality. All patients should receive - aspirin 300mg - nitrates or morphine to relieve chest pain if required Supplementary oxygen should be routinely given unless there are compelling reasons not to do so. Antithrombin treatment. Low molecular weight heparin should be offered to patients who are not at a high risk of bleeding and who are not having angiography within the next 24 hours. If angiography is likely within 24 hours or a patients creatinine is > 265 umol/l unfractionated heparin should be given. Clopidogrel 300mg should be given to patients with a predicted 6 month mortality of more than 1.5% or patients who may undergo percutaneous coronary intervention within 24 hours of admission to hospital. Clopidogrel should be continued for 12 months. Dual antiplatelet therapy should be given for patients who have undergone PCI and this should be continued for 12 months. Intravenous glycoprotein IIb/IIIa receptor antagonists (eptifibatide or tirofiban) should be given to patients who have an intermediate or higher risk of adverse cardiovascular events (predicted 6-month mortality above 3.0%), and who are scheduled to undergo angiography within 96 hours of hospital admission. These agents should be not be administered to those patients who are being considered for PCI as their primary intervention. Coronary angiography should be considered within 96 hours of first admission to hospital to patients who have a predicted 6-month mortality above 3.0%. It should also be performed as soon as possible in patients who are clinically unstable. Coronary angiography is the preferred modality for those patients within 12 hours of acute STEMI.

Answer 1959

In this setting Staphylococcus aureus Infection is the most likely cause. In the UK between 2010 and 2011 the commonest cause of wound infection was enterobacter infections (usually following cardiac or colonic surgery). 23% of infections were due to Staph aureus, which fits the scenario above. Infection with the other organisms including strep pyogenes was much rarer. Surgical site infection - Surgical site infections may occur following a breach in tissue surfaces and allow normal commensals and other pathogens to initiate infection. They are a major cause of morbidity and mortality. Surgical site infections (SSI) comprise up to 20% of all healthcare associated infections and at least 5% of patients undergoing surgery will develop an SSI as a result. In many cases the organisms are derived from the patient's own body. Measures that may increase the risk of SSI include: Shaving the wound using a razor (disposable clipper preferred) Using a non iodine impregnated incise drape if one is deemed to be necessary Tissue hypoxia Delayed administration of prophylactic antibiotics in tourniquet surgery Preoperatively Don't remove body hair routinely If hair needs removal, use electrical clippers with single use head (razors increase infection risk) Antibiotic prophylaxis if: - placement of prosthesis or valve - clean-contaminated surgery - contaminated surgery Use local formulary Aim to give single dose IV antibiotic on anaesthesia If a tourniquet is to be used, give prophylactic antibiotics earlier Intraoperatively Prepare the skin with alcoholic chlorhexidine (Lowest incidence of SSI) Cover surgical site with dressing A recent meta analysis has confirmed that administration of supplementary oxygen does not reduce the risk of wound infection. In contrast to previous individual RCT's(1) Wound edge protectors do not appear to confer benefit (2) Post operatively Tissue viability advice for management of surgical wounds healing by secondary intention Use of diathermy for skin incisions In the NICE guidelines the use of diathermy for skin incisions is not advocated(3). Several randomised controlled trials have been undertaken and demonstrated no increase in risk of SSI when diathermy is used(4). References 1. Brar M et al.. Perioperative supplemental oxygen in colorectal patients: a meta analysis. J Surg Res 2011 (166): 227 -235. 2. Pinkney T et al. Impact of wound edge protection devices on surgical site infection after laparotomy: impact of a multicentre randomised controlled trial (ROSSINI Trial). BMJ 2013 (347):10. 3. http://www.nice.org.uk/CG74 4. Ahmad N and Ahmed A. Meta-analysis of the effectiveness of surgical scalpel or diathermy in making abdominal skin incisions. Ann Surg 2011, 253(1):8-13.

Answer 1960

Although they are small, the submandibular glands provide the bulk of salivary secretions and contribute 70%, the sublingual glands provide 5% and the remainder from the parotid. During food consumption the contribution of the parotid secretions is greater. Submandibular gland Relations of the submandibular gland Superficial Platysma, deep fascia and mandible Submandibular lymph nodes Facial vein (facial artery near mandible) Marginal mandibular nerve Cervical branch of the facial nerve Deep Facial artery (inferior to the mandible) Mylohyoid muscle Sub mandibular duct Hyoglossus muscle Lingual nerve Submandibular ganglion Hypoglossal nerve Submandibular duct (Wharton's duct) Opens lateral to the lingual frenulum on the anterior floor of mouth. 5 cm length Lingual nerve wraps around Wharton's duct. As the duct passes forwards it crosses medial to the nerve to lie above it and then crosses back, lateral to it, to reach a position below the nerve. Innervation Sympathetic innervation- Derived from superior cervical ganglion Parasympathetic innervation- Submandibular ganglion via lingual nerve Arterial supply Branch of the facial artery. The facial artery passes through the gland to groove its deep surface. It then emerges onto the face by passing between the gland and the mandible. Venous drainage Anterior facial vein (lies deep to the Marginal Mandibular nerve) Lymphatic drainage Deep cervical and jugular chains of nodes

Answer 1961

A post menopausal woman is more likely to have a ductal carcinoma and they tend to occur at a single focus within the breast. Breast cancer - Commoner in the older age group Invasive ductal carcinomas are the most common type. Some may arise as a result of ductal carcinoma in situ (DCIS). There are associated carcinomas of special type e.g. Tubular that may carry better prognosis. The pathological assessment involves assessment of the tumour and lymph nodes, sentinel lymph node biopsy is often used to minimise the morbidity of an axillary dissection. Treatment, typically this is either wide local excision or mastectomy. There are many sub types of both of these that fall outside of the MRCS. Some key rules to bear in mind. Whatever operation is contemplated the final cosmetic outcome does have a bearing. A woman with small breasts and a large tumour will tend to fare better with mastectomy, even if clear pathological and clinical margins can be obtained. Conversely a women with larger breasts may be able to undergo breast conserving surgery even with a relatively large primary lesion (NB tumours >4cm used to attract recommendation for mastectomy). For screen detected and impalpable tumour image guidance will be necessary. Reconstruction is always an option following any resectional procedure. However, its exact type must be tailored to age and co-morbidities of the patient. The main operations in common use include latissimus dorsi myocutaneous flap and sub pectoral implants. Women wishing to avoid a prosthesis may be offered TRAM or DIEP flaps. Surgical options Mastectomy vs Wide local excision Mastectomy Wide Local Excision Multifocal tumour Solitary lesion Central tumour Peripheral tumour Large lesion in small breast Small lesion in large breast DCIS >4cm DCIS <4cm Patient Choice Patient choice Central lesions may be managed using breast conserving surgery where an acceptable cosmetic result may be obtained, this is rarely the case in small breasts A compelling indication for mastectomy, a larger tumour that would be unsuitable for breast conserving surgery

Answer 1962

Normal saline has the highest chloride content and excessive administration of normal saline is a recognised risk factor for the development of hyperchloraemic metabolic acidosis.

Answer 1963

Thyroglossal cyst is always located in the midline as it is this route that the thyroid takes during its embryological descent. Its connection with the foramen caecum means it will move on tongue protrusion. Neck lumps The table below gives characteristic exam question features for conditions causing neck lumps: Reactive lymphadenopathy By far the most common cause of neck swellings. There may be a history of local infection or a generalised viral illness Lymphoma Rubbery, painless lymphadenopathy The phenomenon of pain whilst drinking alcohol is very uncommon There may be associated night sweats and splenomegaly Thyroid swelling May be hypo-, eu- or hyperthyroid symptomatically Moves upwards on swallowing Thyroglossal cyst More common in patients < 20 years old Usually midline, between the isthmus of the thyroid and the hyoid bone Moves upwards with protrusion of the tongue May be painful if infected Pharyngeal pouch More common in older men Represents a posteromedial herniation between thyropharyngeus and cricopharyngeus muscles Usually not seen, but if large then a midline lump in the neck that gurgles on palpation Typical symptoms are dysphagia, regurgitation, aspiration and chronic cough Cystic hygroma A congenital lymphatic lesion (lymphangioma) typically found in the neck, classically on the left side Most are evident at birth, around 90% present before 2 years of age Branchial cyst An oval, mobile cystic mass that develops between the sternocleidomastoid muscle and the pharynx Develop due to failure of obliteration of the second branchial cleft in embryonic development Usually present in early adulthood Cervical rib More common in adult females Around 10% develop thoracic outlet syndrome Carotid aneurysm Pulsatile lateral neck mass which doesn't move on swallowing

Answer 1964

Pyogenic granulomas often appear at sites of trauma. Skin Diseases Skin lesions may be referred for surgical assessment, but more commonly will come via a dermatologist for definitive surgical management. Skin malignancies include basal cell carcinoma, squamous cell carcinoma and malignant melanoma. Basal Cell Carcinoma Most common form of skin cancer. Commonly occur on sun exposed sites apart from the ear. Sub types include nodular, morphoeic, superficial and pigmented. Typically slow growing with low metastatic potential. Standard surgical excision, topical chemotherapy and radiotherapy are all successful. As a minimum a diagnostic punch biopsy should be taken if treatment other than standard surgical excision is planned. Squamous Cell Carcinoma Again related to sun exposure. May arise in pre - existing solar keratoses. May metastasize if left. Immunosupression (e.g. following transplant), increases risk. Wide local excision is the treatment of choice and where a diagnostic excision biopsy has demonstrated SCC, repeat surgery to gain adequate margins may be required. Malignant Melanoma The main diagnostic features (major criteria): Change in size Change in shape Change in colour Secondary features (minor criteria) Diameter >6mm Inflammation Oozing or bleeding Altered sensation Treatment Suspicious lesions should undergo excision biopsy. The lesion should be removed completely as incision biopsy can make subsequent histopathological assessment difficult. Once the diagnosis is confirmed the pathology report should be reviewed to determine whether further re-excision of margins is required (see below): Margins of excision-Related to Breslow thickness Lesions 0-1mm thick 1cm Lesions 1-2mm thick 1- 2cm (Depending upon site and pathological features) Lesions 2-4mm thick 2-3 cm (Depending upon site and pathological features) Lesions >4 mm thick 3cm Marsden J et al. Revised UK guidelines for management of Melanoma. Br J Dermatol 2010 163:238-256. Further treatments such as sentinel lymph node mapping, isolated limb perfusion and block dissection of regional lymph node groups should be selectively applied. Kaposi Sarcoma Tumour of vascular and lymphatic endothelium. Purple cutaneous nodules. Associated with immuno supression. Classical form affects elderly males and is slow growing. Immunosupression form is much more aggressive and tends to affect those with HIV related disease. Non malignant skin disease Dermatitis Herpetiformis Chronic itchy clusters of blisters. Linked to underlying gluten enteropathy (coeliac disease). Dermatofibroma Benign lesion. Firm elevated nodules. Usually history of trauma. Lesion consists of histiocytes, blood vessels and fibrotic changes. Pyogenic granuloma Overgrowth of blood vessels. Red nodules. Usually follow trauma. May mimic amelanotic melanoma. Acanthosis nigricans Brown to black, poorly defined, velvety hyperpigmentation of the skin. Usually found in body folds such as the posterior and lateral folds of the neck, the axilla, groin, umbilicus, forehead, and other areas. The most common cause of acanthosis nigricans is insulin resistance, which leads to increased circulating insulin levels. Insulin spillover into the skin results in its abnormal increase in growth (hyperplasia of the skin). In the context of a malignant disease, acanthosis nigricans is a paraneoplastic syndrome and is then commonly referred to as acanthosis nigricans maligna. Involvement of mucous membranes is rare and suggests a coexisting malignant condition.

Answer 1965

5 alpha reductase inhibitors have a more favorable side effect profile than α blockers. Alpha blockers have a faster onset of action (but lower reduction of complications from BPH) than 5 α reductase inhibitors. Benign Prostatic Hyperplasia Benign prostatic hyperplasia occurs via an increase in the epithelial and stromal cell numbers in the peri-urethral zone of the prostate. BPH is very common and 90% of men aged over 80 will have at least microscopic evidence of benign prostatic hyperplasia. The causes of BPH are still not well understood, but the importance of androgens remains appreciated even if the exact role by which they induce BPH is elusive. Presentation The vast majority of men will present with lower urinary tract symptoms. These will typically be: Poor flow Nocturia Hesitancy Incomplete and double voiding Terminal dribbling Urgency Incontinence Investigation Digital rectal examination to assess prostatic size and morphology. Urine dipstick for infections and haematuria. Uroflowmetry (a flow rate of >15ml/second helps to exclude BOO) Bladder pressure studies may help identify detrusor failure and whilst may not form part of first line investigations should be included in those with atypical symptoms and prior to redo surgery. Bladder scanning to demonstrate residual volumes. USS if high pressure chronic retention. Management Lifestyle changes such as stopping smoking and altering fluid intake may help those with mild symptoms. Medical therapy includes alpha blockers and 5 α reductase inhibitors. The former work quickly on receptor zones located at the bladder neck. Cardiovascular side effects are well documented. The latter work on testosterone metabolising enzymes. Although they have a slower onset of action, the 5 α reductase inhibitors may prevent acute urinary retention. Surgical therapy includes transurethral resection of the prostate and is the treatment of choice in those with severe symptoms and those who fail to respond to medical therapy. More tailored bladder neck incision procedures may be considered in those with small prostates. Retrograde ejaculation may occur following surgery. The change in the type of irrigation solutions used has helped to minimise the TURP syndrome of electrolyte disturbances.

Answer 1966

Blood stained nipple discharge should always be investigated. Nipple fluid cytology is generally unhelpful. Discharge of this type of material is most likely to be due to duct ectasia. Green or brown discharge is most common. Blood stained discharge should raise concern of intraductal papilloma or cancer. Nipple discharge Causes of nipple discharge Physiological During breast feeding Galactorrhoea Commonest cause may be response to emotional events, drugs such as histamine receptor antagonists are also implicated Hyperprolactinaemia Commonest type of pituitary tumour Microadenomas <1cm in diameter Macroadenomas >1cm in diameter Pressure on optic chiasm may cause bitemporal hemianopia Mammary duct ectasia Dilatation breast ducts. Most common in menopausal women Discharge typically thick and green in colour Most common in smokers Carcinoma Often blood stained May be underlying mass or axillary lymphadenopathy Intraductal papilloma Commoner in younger patients May cause blood stained discharge There is usually no palpable lump Assessment of patients Examine breast and determine whether there is mass lesion present All mass lesions should undergo Triple assessment. Reporting of investigations Where a mass lesion is suspected or investigations are requested these are prefixed using a system that denotes the investigation type e.g. M for mammography, followed by a numerical code as shown below: 1 No abnormality 2 Abnormality with benign features 3 Indeterminate probably benign 4 Indeterminate probably malignant 5 Malignant Management of non malignant nipple discharge Exclude endocrine disease Nipple cytology unhelpful Smoking cessation advice for duct ectasia For duct ectasia with severe symptoms, total duct excision may be warranted.

Answer 1967

Periductal mastitis is common in smokers and may present with recurrent infections. Treatment is with co-amoxiclav. Mondors disease of the breast is a localised thrombophlebitis of a breast vein. Duct ectasia Duct ectasia is a dilatation and shortening of the terminal breast ducts within 3cm of the nipple. It is common and the incidence increases with age. It typically presents with nipple retraction and occasionally creamy nipple discharge. It may be confused with periductal mastitis, which presents in younger women, the vast majority of which are smokers. Periductal mastitis typically presents with periareolar or sub areolar infections and may be recurrent. Patients with troublesome nipple discharge may be treated by microdochectomy (if young) or total duct excision (if older).

Answer 1968

Stipple cells are found in lead poisoning/haemoglobinopathies. Blood film in hyposplenism: Howell-Jolly bodies Pappenheimer bodies Poikilocytes (Target cells) Erythrocyte containing siderotic granules Heinz bodies Post splenectomy blood film changes The loss of splenic tissue results in the inability to readily remove immature or abnormal red blood cells from the circulation. The red cell count does not alter significantly. However, cytoplasmic inclusions may be seen e.g. Howell-Jolly bodies. In the first few days after splenectomy target cells, siderocytes and reticulocytes will appear in the circulation. Immediately following splenectomy a granulocytosis (mainly composed of neutrophils) is seen, this is replaced by a lymphocytosis and monocytosis over the following weeks. The platelet count is usually increased and this may be persistent, oral antiplatelet agents may be needed in some patients.

Answer 1969

A meta- analysis of more than one well designed trials will typically represent level I evidence. It does, of course, depend on how well the trials were conducted and reported. Levels of evidence The level of evidence refers to the study design used by investigators to minimise bias. Level of evidence Source I Evidence obtained from systematic review of all relevant randomised controlled trials II Evidence derived from at least one properly designed randomised controlled trial III Evidence derived from well designed pseudo-randomised controlled trials (e.g. alternate allocation) or historical controls IV Evidence derived from case series or case reports V Panel or expert opinion Many of the categories contain sub groups, detailed knowledge of these are not required for MRCS Part A. References Interested users will find further information at www.cebm.net

Answer 1970

Facial nerve palsy is the commonest neurological manifestation of sarcoid. It usually resolves. The absence of a discrete lesion on palpation is against the other causes. Parotid gland clinical Benign neoplasms Up to 80% of all salivary gland tumours occur in the parotid gland and up to 80% of these are benign. There is no consistent correlation between the rate of growth and the malignant potential of the lesion. However, benign tumours should not invade structures such as the facial nerve. With the exception of Warthins tumours, they are commoner in women than men. The median age of developing a lesion is in the 5th decade of life. Benign tumour types Tumour type Features Benign pleomorphic adenoma or benign mixed tumor Most common parotid neoplasm (80%) Proliferation of epithelial and myoepithelial cells of the ducts and an increase in stromal components Slow growing, lobular, and not well encapsulated Recurrence rate of 1-5% with appropriate excision (parotidectomy) Recurrence possibly secondary to capsular disruption during surgery Malignant degeneration occurring in 2-10% of adenomas observed for long periods, with carcinoma ex-pleomorphic adenoma occurring most frequently as adenocarcinoma Warthin tumor (papillary cystadenoma lymphoma or adenolymphoma) Second most common benign parotid tumor (5%) Most common bilateral benign neoplasm of the parotid Marked male as compared to female predominance Occurs later in life (sixth and seventh decades) Presents as a lymphocytic infiltrate and cystic epithelial proliferation May represent heterotopic salivary gland epithelial tissue trapped within intraparotid lymph nodes Incidence of bilaterality and multicentricity of 10% Malignant transformation rare (almost unheard of) Monomorphic adenoma Account for less than 5% of tumours Slow growing Consist of only one morphological cell type (hence term mono) Include; basal cell adenoma, canalicular adenoma, oncocytoma, myoepitheliomas Haemangioma Should be considered in the differential of a parotid mass in a child Accounts for 90% of parotid tumours in children less than 1 year of age Hypervascular on imaging Spontaneous regression may occur and malignant transformation is almost unheard of Malignant salivary gland tumours Types of malignancy Mucoepidermoid carcinoma 30% of all parotid malignancies Usually low potential for local invasiveness and metastasis (depends mainly on grade) Adenoid cystic carcinoma Unpredictable growth pattern Tendency for perineural spread Nerve growth may display skip lesions resulting in incomplete excision Distant metastasis more common (visceral rather than nodal spread) 5 year survival 35% Mixed tumours Often a malignancy occurring in a previously benign parotid lesion Acinic cell carcinoma Intermediate grade malignancy May show perineural invasion Low potential for distant metastasis 5 year survival 80% Adenocarcinoma Develops from secretory portion of gland Risk of regional nodal and distant metastasis 5 year survival depends upon stage at presentation, may be up to 75% with small lesions with no nodal involvement Lymphoma Large rubbery lesion, may occur in association with Warthins tumours Diagnosis should be based on regional nodal biopsy rather than parotid resection Treatment is with chemotherapy (and radiotherapy) Diagnostic evaluation Plain x-rays may be used to exclude calculi Sialography may be used to delineate ductal anatomy FNAC is used in most cases Superficial parotidectomy may be either diagnostic or therapeutic depending upon the nature of the lesion Where malignancy is suspected the primary approach should be definitive resection rather than excisional biopsy CT/ MRI may be used in cases of malignancy for staging primary disease Treatment For nearly all lesions this consists of surgical resection, for benign disease this will usually consist of a superficial parotidectomy. For malignant disease a radical or extended radical parotidectomy is performed. The facial nerve is included in the resection if involved. The need for neck dissection is determined by the potential for nodal involvement. Other parotid disorders HIV infection Lymphoepithelial cysts associated with HIV occur almost exclusively in the parotid Typically presents as bilateral, multicystic, symmetrical swelling Risk of malignant transformation is low and management usually conservative Sjogren syndrome Autoimmune disorder characterised by parotid enlargement, xerostomia and keratoconjunctivitis sicca 90% of cases occur in females Second most common connective tissue disorder Bilateral, non tender enlargement of the gland is usual Histologically, the usual findings are of a lymphocytic infiltrate in acinar units and epimyoepithelial islands surrounded by lymphoid stroma Treatment is supportive There is an increased risk of subsequent lymphoma Sarcoid Parotid involvement occurs in 6% of patients with sarcoid Bilateral in most cases Gland is not tender Xerostomia may occur Management of isolated parotid disease is usually conservative

Answer 1971

This is a Maisonneuve fracture of the proximal fibula. It indicates an unstable ankle injury with likely injury to the interosseous membrane. In the setting of radiographic evidence of syndesmotic widening, this requires surgical fixation to reduce and stabilise the syndesmosis. Ankle injuries An ankle fracture relates to a fracture around the tibio-talar joint. It generally refers to a fracture involving the lateral, and/or medial and/or posterior malleolus. Pilon and Tillaux fractures are also considered to be ankle fractures, but are not covered here. Ankle fractures are common. They effect men and women in equal numbers, but men have a higher rate as young adults (sports and contact injuries), and women a higher rate post-menopausal (fragility type fracture). Osseous anatomy The ankle (or mortise) joint consists of the distal tibia (tibial plafond and posterior malleolus), the distal fibula (lateral malleolus), and the talus. The main movement at the ankle joint is plantar and dorsiflexion. Ligamentous anatomy Medial side: Deltoid ligament. This is divided into superficial and deep portions. It is the primary restraint to valgus tilting of the talus. Lateral side: Lateral ligament complex consisting from anterior to posterior of the anterior talofibular ligament (ATFL), calcaneofibular ligament (CFL), and the posterior talofibular ligament (PTFL). Together they resist valgus stress to the ankle, and are a restraint to anterior translation of the talus within the mortise joint. Syndesmosis: The syndesmosis is a ligament complex between the distal tibia and fibula, holding the two bones together. It is fundamental to the integrity of the ankle joint, and its disruption leads to instability. It consists of (from anterior to posterior) the anterior-inferior tibiofibular ligament (AITFL), the transverse tibiofibular ligament (TTFL), the interosseous membrane, and the posterior-inferior tibiofibular ligament (PITFL). Presentation and initial management Patients will present following a traumatic event with a painful, swollen ankle, and reluctance/inability to weight bear. The Ottawa rules can be applied to differentiate between an ankle fracture and sprain, but can be unreliable. In high energy injuries, management should follow ATLS principles to identify more significant injuries first. Neurovascular status of the foot should be documented, and open injuries should be excluded. If an open injury is identified, it should be managed in line with BOAST 4 principles1. If an obvious deformity exists, it should be reduced as soon as possible with appropriate analgesia or conscious sedation. Radiographs of clearly deformed or dislocated joints are not necessary, and removing the pressure on the surrounding soft tissues from the underlying bony deformity is the priority. If the fracture pattern is not clinically obvious then plain radiographs are appropriate and will guide the subsequent manipulation during plaster-of-paris below knee backslab application. Imaging AP, lateral and mortise views (20 degrees internal rotation) are essential to evaluate fracture displacement and syndesmotic injury. Decreased tibiofibular overlap, medial joint clear space and lateral talar shift all indicate a syndesmotic injury. (In subtle cases of shift, imaging the uninjured ankle can be helpful as a proportion of the population have little or no tibiotalar overlap-reference 2.) Where there is suspicion of syndesmosis involvement in the absence of radiographic evidence, stress radiographs can be diagnostic. Complex fracture patterns (and increasingly posterior malleolar fractures) are best defined using CT. Classification The most commonly used classifications are Lauge-Hansen and Danis-Weber. Lauge-Hansen Comprises two parts: first part is the foot position, and the second part is the force applied. Useful for understanding the forces involved and therefore predict the ligamentous or bony injury. Results in four injury patterns: Supination - Adduction (SA) - 10-20% Supination - External rotation (SER) - 40-75% Pronation - Abduction (PA) - 5-20% Pronation - External rotation (PER) - 5-20% Not often used in clinical practice but good for understanding the principles of ankle fracture. Danis-Weber Commonly used. Based on the level of the fibula fracture in relation to the syndesmosis. The more proximal, the greater the risk of syndesmotic injury and therefore fracture instability. A - fracture below the level of the syndesmosis B - fracture at the level of the syndesmosis / level of the tibial plafond C - fracture above the level of the syndesmosis. This includes Maisonneuve fractures (proximal fibula fracture), which can be associated with ankle instability. Beware the high fibula fracture - it may be an ankle fracture! The Weber classification is based purely on the the lateral side. All injuries can include a medial or posterior bony or ligamentous injury which also dictates fracture stability (bimalleolar and trimalleolar fractures are more unstable). Treatment When deciding upon treatment for an ankle fracture, one must consider both the fracture and the patient. Diabetic patients and smokers are at greater risk of post-operative complication, especially wound problems and infection. Likewise, the long term outcome of post-traumatic arthritis from a malunited ankle fracture is extremely important for a young patient, but not as relevant in the elderly. Therefore, normal surgical decision processes apply as with all fractures. Defining stability of an ankle fracture underpins the treatment decision. Weber A - Unimalleolar Weber A Weber fractures by definition are stable and therefore can be mobilised fully weight bearing in an ankle boot. Weber C - Fractures tend to include syndesmotic disruption and are usually bimalleolar (either bony or ligamentous). They are therefore unstable and usually require operative fixation. In addition to the fracture fixation, the syndesmosis usually requires reconstruction/augmentation with screws to restore the joint integrity and function. Weber B - B fractures vary greatly. They can be part of a trimalleolar injury and therefore extremely unstable, requiring fixation. Alternatively, a uni-malleolar Weber B fracture can be a stable injury, and therefore mobilised immediately in an ankle boot. Defining the stability can be challenging, and often involves stress radiographs, or a trial of mobilisation and repeat radiographs. However, treating undisplaced ankle fractures in a below knee plaster, non-weight bearing for six weeks is still widely practised, and a safe approach. When operative fixation is appropriate, it is usually via open reduction and internal fixation using plates and screws. It must be carried out when soft tissue swelling has settled in order to minimise the risk of wound problems. This can often take a week to settle. The use of fibula nails is expanding, but is not yet mainstream. Ankle fractures can also be treated with external fixation, or with a hind foot nail in patients who need fixation but where soft tissue or bone quality is poor. Post operative management Ankle fractures generally take 6 weeks to unite enough to prevent secondary displacement. This is therefore an appropriate time period to keep a cast on in a conservatively managed patient. Weight bearing post-operatively depends on the quality of the fixation and bone quality, and preference varies between surgeons, ranging from aggressive early mobilisation to a period of non-weight bearing. Return to activities takes approximately three months, and often requires assistance of a physiotherapist to improve range-of-movement and muscle strengthening. References 1. http://www.boa.ac.uk/publications/boa-standards-trauma-boasts/ 2. Shah AS, Kadakia AR, Tan GJ, Karadsheh MS, Wolter TD, Sabb B. Radiographic evaluation of the normal distal tibiofibular syndesmosis. Foot Ankle Int. 2012;33(10):870-6

Answer 1972

The scaphoid bone forms the floor of the anatomical snuffbox. The cutaneous branch of the radial nerve is much more superficially and proximally located. Anatomical snuffbox Posterior border Tendon of extensor pollicis longus Anterior border Tendons of extensor pollicis brevis and abductor pollicis longus Proximal border Styloid process of the radius Distal border Apex of snuffbox triangle Floor Trapezium and scaphoid Content Radial artery

Answer 1973

C-1850 mls The haemodynamic changes described would equate to class III shock. In the context of fundoplication surgery, splenic injury would be the cause. Bleeding The initial response to bleeding, even if of relatively small volume is generalised splanchnic vasoconstriction mediated by activation of the sympathetic nervous system. This process of vasoconstriction is usually sufficient to maintain renal perfusion and cardiac output if the volume of blood lost is small. Over the following hours the circulating fluid volume is restored and normal haemodynamics resume. Loss of greater volumes of blood will typically result in activation in the renin angiotensin system Where the source of bleeding ceases these physiological measures will restore circulating volume. Ongoing bleeding will result in haemorrhagic shock. Blood loss is typically quantified by the degree of shock produced as outlined below: Parameter Class I Class II Class III Class IV Blood loss ml <750ml 750-1500ml 1500-2000ml >2000ml Blood loss % <15% 15-30% 30-40% >40% Pulse rate <100 >100 >120 >140 Blood pressure Normal Normal Decreased Decreased Respiratory rate 14-20 20-30 30-40 >35 Urine output >30ml 20-30ml 5-15ml <5ml Symptoms Normal Anxious Confused Lethargic

Answer 1974

Achondroplasia usually occurs as a sporadic mutation. It is then transmitted in an autosomal dominant fashion. Achondroplasia Achondroplasia is a common cause of dwarfism and is caused by defects in the fibroblast growth factor receptor. In most cases (approximately 70%) it occurs as a sporadic mutation. The main risk factor is advancing parental age at the time of conception. Once present it is typically inherited in an autosomal dominant fashion. Radiological features Large skull with narrow foramen magnum Short, flattened vertebral bodies Narrow spinal canal Horizontal acetabular roof Broad, short metacarpals Treatment There is no specific therapy. However, some individuals benefit from limb lengthening procedures. These usually involve application of Ilizarov frames and targeted bone fractures. A clearly defined need and end point is the cornerstone of achieving success with such procedures.

Answer 1975

The superior sagittal sinus is unpaired The superior sagittal sinus is unpaired. It begins at the crista galli, where it may communicate with the veins of the frontal sinus and sometimes with those of the nasal cavity. It arches backwards in the falx cerebri to terminate at the internal occipital protuberance (usually into the right transverse sinus). The parietal emissary veins link the superior sagittal sinus with the veins on the exterior of the cranium. Cranial venous sinuses The cranial venous sinuses are located within the dura mater. They have no valves which is important in the potential for spreading sepsis. They eventually drain into the internal jugular vein. They are: Superior sagittal sinus Inferior sagittal sinus Straight sinus Transverse sinus Sigmoid sinus Confluence of sinuses Occipital sinus Cavernous sinus

Answer 1976

A local rotational flap or full thickness graft would both be acceptable options here. Tissue reconstruction Skin Grafts and Flaps Skin flaps or grafts may be required where primary wound closure cannot be achieved or would entail either significant cosmetic defect or considerable functional disturbance as a result of wound contraction. Reconstructive ladder Method Types Direct closure The simplest option where possible Grafting techniques Split thickness Full thickness Skin Substitute Composite Flap technique Local: Transposition Pivot Alphabetoplasty (e.g. Z-Y) Regional: Myocutaneous Fasciocutaneous Neurocutaneous Distant: Free tissue transfer Prelamination techniques Allows creation of specialised flaps e.g. buccal mucosa Tissue expansion Involves placement of tissue expanders to increase amount of tissue at donor sites Skin Grafts Vs. Flaps Skin Grafts Flaps No size limit (Split)/ Relative size limit (full thickness) Size limited by territory of blood supply Rely on wound bed for blood supply Tissue has its own blood supply Take better on clean well vascularised wound beds Will survive independent of the wound bed Split skin graft donor site typically heals in 12 days Direct closure of donor site or secondary skin graft Donor site may be reused Donor site cannot be reused Split thickness skin grafts Available in range of thicknesses. Thigh is the commonest donor site Size may be increased by meshing the graft. However this comes with compromise on cosmesis. Donor sites, especially if thin grafts are taken can be reused following re-epithelialisation Full thickness grafts Most commonly used for facial reconstruction Include dermal appendages Provide superior cosmetic result Composite grafts These are grafts containing more than one tissue type, such as skin and fat. They are usually used to cover small defects in cosmetically important areas. Flaps Flaps have their own blood supply and may be pedicled or free. May have multiple components e.g. skin, skin + fat, skin + fat + muscle. They will have the ability to take regardless of the underlying tissue bed. The type of intrinsic blood supply is important. For example in breast surgery pedicled latissimus dorsi flaps will be less prone to failure than microsvascular anastomosed free Diep flaps.

Answer 1977

Pagets is typically associated with thickened, sclerotic, long bones. Lung carcinoma typically causes lytic bony lesions and hypercalcaemia. Pagets disease Paget's disease is a disease of increased but uncontrolled bone turnover and is characterised by architecturally abnormal bones. It is thought to be primarily a disorder of osteoclasts, with excessive osteoclastic resorption followed by increased osteoblastic activity causing areas of sclerosis and deformity. Paget's disease is common (UK prevalence 5%) but symptomatic in only 1 in 20 patients Predisposing factors increasing age male sex northern latitude family history Clinical features bone pain (e.g. pelvis, lumbar spine, femur) classical, untreated features: bowing of tibia, bossing of skull raised alkaline phosphatase (ALP) - calcium* and phosphate are typically normal skull x-ray: thickened vault, osteoporosis circumscripta Indications for treatment include bone pain, skull or long bone deformity, fracture, periarticular Paget's bisphosphonate (either oral risedronate or IV zoledronate) calcitonin is less commonly used now Complications deafness (cranial nerve entrapment) bone sarcoma (1% if affected for > 10 years) fractures skull thickening high-output cardiac failure *usually normal in this condition but hypercalcaemia may occur with prolonged immobilisation

Answer 1978

Infection with Trypanosoma Cruzi may result in destruction of the ganglion cells of the myenteric plexus, resulting in a clinical picture similar to achalasia. Trypanosoma Cruzi Protozoan Causes Chagas disease Carried by bugs which infect the skin whilst feeding Penetrate through open wounds and mucous membranes Intracellular proliferation Major infective sites include CNS, intestinal myenteric plexus, spleen, lymph nodes and cardiac muscle Chronic disease is irreversible, nifurtimox is used to treat acute infection

Answer 1979

Drug treatment is with albendazole or mebendazole. Praziquantzel may be used in the pre operative stages. Hydatid cysts Hydatid cysts are endemic in Mediterranean and Middle Eastern countries. They are caused by the tapeworm parasite Echinococcus granulosus. An outer fibrous capsule is formed containing multiple small daughter cysts. These cysts are allergens which precipitate a type 1 hypersensitivity reaction. Clinical features are as follows: Up to 90% cysts occur in the liver and lungs Can be asymptomatic, or symptomatic if cysts > 5cm in diameter Morbidity caused by cyst bursting, infection and organ dysfunction (biliary, bronchial, renal and cerebrospinal fluid outflow obstruction) In biliary rupture there may be the classical triad of; biliary colic, jaundice, and urticaria CT is the best investigation to differentiate hydatid cysts from amoebic and pyogenic cysts. Surgery is the mainstay of treatment (the cyst walls must not be ruptured during removal and the contents sterilised first).

Answer 1980

• Interstitial cystitis(chronic pelvic pain syndrome):This is a persistent, painful form of chronic cystitis occurring mostly in women. The etiology of which is unknown. o Some pt with this condition show chronic mucosal ulcers (Hunner ulcers). o Late in this disease, there is transmural fibrosis leading to a contracted bladder o Interstitial cystitis is characterized by suprapubic pain, hematuria, dysuria, frequency without evidence of bacterial infection. Why Other Options Are Incorrect: • A) Gram-negative urinary tract infection: UTIs can cause dysuria and hematuria, but they are typically associated with a single episode rather than recurrent painful hematuria. • C) Renal cell carcinoma: Hematuria in renal cell carcinoma is usually painless and may not present with recurrent attacks of painful hematuria. • D) Transitional cell carcinoma of the bladder: Bladder cancer often causes painless hematuria, although pain may occur in advanced stages. • E) Urinary tuberculosis: This can present with hematuria, but pain is not as common, and it is more likely in patients with specific risk factors or systemic signs of tuberculosis.

Answer 1981

A-Hypoglycemia Early adrenergic symptoms: Pallor, Diaphoresis, Shakiness, Hunger, Anxiety, Irritability, Headache, Dizziness Neuroglycopenic signs: Confusion, Slurred speech, Irrational or uncontrolled behavior, Disorientation, Loss of consciousness, Seizures, Pupillary sluggishness, Decreased response to noxious stimuli

Answer 1982

Carcinoma of Thyroid Type: Papillary Spread: Lymphatic, to local nodes (%): 60-70 Age: young adults 20-40 (<45y), Prognosis: Excellent Follicular: Blood stream, especially to bone, % 20-25, Young-middle 40-50 (>45), Good with radio-iodine therapy. Anaplastic: Aggressive local extension, % 10-15, Elderly, Very poor Medullary (C-cells): Local, lymphatic, blood stream, % 5-10, Usually elderly, but familial cases occur, Variable. More aggressive in familial cases

Answer 1983

Layers traversed by the spinal needle (posterior to anterior) • Skin • Subcutaneous tissue • Supraspinous ligament • Interspinous ligament • Ligamentum flavum • Duramater • Sub dural space • Arachnoidmater • Subarachnoid space

Answer 1984

In a case of meningitis caused by Neisseria meningitidis, the predominant cell type in the cerebrospinal fluid (CSF) is typically: e. Neutrophils Neutrophils are the primary white blood cells that respond to bacterial infections. In bacterial meningitis, the rapid accumulation of neutrophils in the CSF is a characteristic feature. Source: • Tunkel, A. R., & Scheld, W. M. (1995). Acute bacterial meningitis. The Lancet, 346(8981), 1675-1680. Link

Answer 1985

Boundaries of femoral ring • Anterior: Inguinal ligament • Posterior: Ligament of Cooper ( pectineal ligament). • Medial: Lacunar ligament (Gimbernat's ligament) • Lateral: Thin septum which separates the femoral canal from femoral vein (silver fascia).

Answer 1986

Lateral to the median nerve

Answer 1987

MULTIPL MYELOMA MNEMONIC: OLD CRAB OLD - Old Age C - Calcium Elevated (Hypercalcemia) R - Renal Failure A - Anemia B - Bone Lytic Lesions

Answer 1988

Urine bilirubin is normally absent. • When it is present, only conjugated bilirubin is passed into the urine. • This may be evidenced by dark-colored urine seen in patients with obstructive jaundice or jaundice due to hepatocellular injury.. • The lack of bilirubin in the intestinal tract is responsible for the pale stools typically associated with biliary obstruction. • The cause of pruritus associated with biliary obstruction is due to accumulation of bile salts in the skin.

Answer 1989

The clinical picture described—drowsiness, hypotension, bradycardia, low voltage complexes, and a prolonged QT interval on the ECG—suggests that the underlying issue is likely related to hypothyroidism. Therefore, the best explanation for her symptoms is under-activity of the thyroid gland. Hypothyroidism can present with several of the symptoms described: • Drowsiness and lethargy • Hypotension • Bradycardia • Low voltage ECG complexes • Prolonged QT interval These are all common manifestations of severe hypothyroidism, which can be confirmed with a thyroid function test measuring levels of TSH (thyroid-stimulating hormone) and thyroid hormones (T3 and T4). In contrast: • Adrenal insufficiency typically presents with symptoms such as fatigue, muscle weakness, weight loss, hypotension, and sometimes hyperpigmentation, but the ECG findings are less specific. • Pancreatic issues are more related to insulin and glucose metabolism, presenting with symptoms of diabetes or hypoglycemia. • Parathyroid gland issues would primarily affect calcium levels, leading to symptoms like muscle cramps or tetany, and would not typically cause the described ECG changes. • Pituitary gland under-activity (hypopituitarism) can have a variety of symptoms depending on which hormones are deficient, but the symptoms described are more directly linked to thyroid hormone deficiency. Thus, the thyroid gland’s under-activity is the most likely explanation for her clinical presentation.

Answer 1990

GASTRINOMA • -Syndrome: Zollinger-Ellison • -Hormone: gastrin , -Clinical features: abdo pain, peptic ulceration, diarrhoea, gastric hypersecretion •-site: duodenum - 70%; pancreas - 25% • - >50% malignant • -Diagnosis: increased serum gastrin > 1000pg/ml basal acid output > 15mEq/hr • -localization: CT/MRI/US -less useful • -Somatostatin receptor scin. - sensitive test

Answer 1991

Inulin is used to measure the glomerular filtration rate (GFR) because it has very specific properties that make it ideal for this purpose. The correct description of why inulin can be used to measure GFR is: a. It is filtered and not reabsorbed. Inulin is a polysaccharide that, when introduced into the body, is freely filtered by the glomeruli in the kidneys. Importantly, once it is filtered, it is neither reabsorbed nor secreted by the renal tubules. This means that the amount of inulin in the urine accurately reflects the amount that was filtered by the glomeruli, allowing for an accurate measurement of GFR.

Answer 1992

The presentation of a 60-year-old man with a headache, confusion, right-sided hemiparesis, and a CT scan showing a 4 cm x 4 cm lesion with central necrosis in the left frontal lobe extending across the midline along the corpus callosum, with extensive edema, is most suggestive of a glioblastoma. Glioblastoma (also known as glioblastoma multiforme or GBM) is the most aggressive and common primary brain tumor in adults. It is characterized by rapid growth and a tendency to infiltrate surrounding brain tissue, often crossing the midline via structures such as the corpus callosum. The central necrosis and significant edema are typical radiological features of glioblastoma.

Answer 1993

The structure responsible for the first hemostatic response to a fall in systemic arterial blood pressure is the baroreceptor. Explanation: Baroreceptors are specialized sensors located primarily in the carotid sinuses and the aortic arch. They detect changes in blood pressure and respond by sending signals to the central nervous system to initiate corrective measures. When a fall in blood pressure is detected, baroreceptors stimulate the autonomic nervous system to increase heart rate, contractility, and vasoconstriction, thereby raising blood pressure. Options Breakdown: a. Adenohypophysis - The adenohypophysis, or anterior pituitary gland, is involved in hormone secretion but not directly in the immediate response to blood pressure changes. b. Baroreceptor - Correct answer. Baroreceptors respond quickly to changes in blood pressure to maintain homeostasis. c. Chemoreceptor - Chemoreceptors respond to changes in blood chemistry (e.g., oxygen, carbon dioxide, pH levels), but they are slower and secondary to the baroreceptors in responding to blood pressure changes. d. Kidney - The kidney plays a role in long-term blood pressure regulation through the renin-angiotensin-aldosterone system, but it is not the first response mechanism. e. Neurohypophysis - The neurohypophysis, or posterior pituitary gland, releases hormones like vasopressin (antidiuretic hormone), which can affect blood pressure but is not the immediate response. Thus, the correct answer is: b. Baroreceptor. & Chemoreceptors Baroreceptors: • Hypotension- Jarterial pressure — stretch → afferent baroreceptor firing Tefferent sympathetic firing and I efferent parasympathetic stimulation → vasoconstriction, T HR,1 contractility→ 1 BP important in response to severe hemorrhage • Carotid massage - pressure on carotid artery 1 stretch → 1 afferent baroreceptor firing → HR Can by tried for Tachycardia (SVT) • Contributes to Cushing reaction (triad of hypertension, bradycardia, and respiratory depression) intracranial pressure constricts arterioles → cerebral ischemia and reflex sympathetic increase in perfusion pressure (hypertension) → 1 stretch → reflex baroreceptor induced-bradycardia Chemoreceptors: • Peripheral-carotid and aortic bodies are stimulated by + POz (< 60 mm Hg), TPCOz, and I pH of blood • Central-are stimulated by changes in pH and PCO2 of brain interstitial fluid, which in turn are influenced by arterial COz Do not directly respond to POz

Answer 1994

Vitamin K is crucial for the synthesis of certain proteins required for blood clotting. Among the given statements, the true statement about the effects and availability of vitamin K is: • Vitamin K absorption is affected by resection of the terminal ileum. Here is an explanation for each option: 1. Affects platelet function: This is incorrect. Vitamin K is involved in the synthesis of clotting factors, not directly in platelet function. Platelets are cell fragments that play a role in blood clotting, but their function is not directly influenced by vitamin K. 2. Causes bleeding if taken in excess: This is incorrect. Vitamin K toxicity is rare and usually occurs with synthetic forms of vitamin K. Excessive vitamin K typically does not cause bleeding; rather, a deficiency in vitamin K leads to bleeding issues. 3. Is provided only by fresh food: This is incorrect. While fresh foods like leafy green vegetables are rich in vitamin K, it is also produced by gut bacteria and can be found in fermented foods and some animal products. 4. Is depleted by broad spectrum oral antibiotics: This is partially correct. Broad-spectrum antibiotics can reduce gut bacteria that produce vitamin K, potentially leading to a deficiency. However, this depletion is not as direct or immediate as the absorption being affected by the resection of the terminal ileum. 5. Vitamin K absorption is affected by resection of the terminal ileum: This is correct. The terminal ileum is the site where bile acids are reabsorbed, and these bile acids are essential for the absorption of fat-soluble vitamins, including vitamin K. If the terminal ileum is resected, the absorption of vitamin K can be significantly impaired. Therefore, the correct statement is: Vitamin K absorption is affected by resection of the terminal ileum.

Answer 1995

In septic shock, norepinephrine (noradrenaline) is used to increase the systemic vascular resistance through the stimulation of alpha-1 (α1) receptors. The correct answer is option A: alfa1 Norepinephrine is a potent alpha-1 adrenergic receptor agonist, and the stimulation of these receptors on the vascular smooth muscle cells leads to vasoconstriction, which increases the systemic vascular resistance (SVR) and helps maintain blood pressure in septic shock. Alpha-1 receptors are found on the vascular smooth muscle cells, and their activation by norepinephrine causes the smooth muscle to contract, resulting in vasoconstriction and an increase in SVR. The other options are incorrect: - Alpha-2 (α2) receptors are primarily involved in inhibiting the release of norepinephrine from presynaptic nerve terminals and have a lesser effect on vascular smooth muscle contraction. - Beta-1 (β1) receptors are found primarily in the heart and mediate positive inotropic and chronotropic effects. - There is no known "Delta 1" receptor subtype involved in this mechanism. Therefore, in septic shock, norepinephrine is used to increase the systemic vascular resistance through the stimulation of alpha-1 (α1) receptors on the vascular smooth muscle cells, leading to vasoconstriction.

Answer 1996

Based on the clinical presentation of progressive facial weakness (lower motor neuron type) and failure of abduction of one eye, along with the finding of a small intrinsic mass lesion within the central nervous system on MRI, the most likely location of the lesion is the pons. The correct answer is e. The pons. Here's the explanation for each option: a. The cerebellar vermis is unlikely to cause these specific cranial nerve deficits. b. The cerebellar tonsil is also an unlikely location for this presentation. c. The medulla is responsible for lower cranial nerve function, but the facial nerve nucleus is located in the pons, making it less likely to be the site of the lesion. d. The midbrain is a possible location, as it contains the nuclei for the oculomotor nerve (CN III) which controls eye movements, including abduction. However, the facial nerve nucleus is located in the pons. e. The pons is the most likely location for the lesion because it contains the nuclei for both the facial nerve (CN VII) and the abducens nerve (CN VI), which control facial movements and lateral eye movement (abduction), respectively. The combination of lower motor neuron facial weakness and failure of abduction of one eye strongly suggests a lesion affecting the facial nerve nucleus and the abducens nerve nucleus, both of which are located in the pons. Therefore, based on the clinical presentation and MRI findings, the most likely location of the small, intrinsic mass lesion within the central nervous system is the pons.

Answer 1997

The most likely pathology for a parotid tumor with extensive perineural invasion is: c. Adenoid cystic carcinoma Here's why: Perineural invasion: Adenoid cystic carcinoma is known to be highly aggressive and has a propensity for perineural invasion, which means the tumor cells spread along nerves. [4] Parotid gland: Adenoid cystic carcinoma is one of the most common malignant tumors of the salivary glands, including the parotid gland. [4] Other options: Acinic cell carcinoma and adenocarcinoma are less common and may show perineural invasion, but not to the same extent as adenoid cystic carcinoma. [2] Lymphoma and pleomorphic salivary adenoma are less likely to exhibit extensive perineural invasion. While a biopsy is necessary for definitive diagnosis, considering the patient's age, location of the tumor (parotid gland), and the presence of extensive perineural invasion, adenoid cystic carcinoma is the most probable pathology.

Answer 1998

A Erythema nodosum

Answer 1999

The most likely causative organism is: Staphylococcus aureus Here's why: Staphylococcus aureus is a common cause of skin and wound infections, especially post-surgical wounds. It lives on the skin and in the nose of many healthy people and can easily enter a wound site during surgery. Symptoms of a Staphylococcus aureus infection often include redness, inflammation, and pus. The other options are less likely: Hemophilus influenzae typically causes respiratory infections. Proteus mirabilis is less common than Staphylococcus aureus in surgical site infections. Pseudomonas aeruginosa is more commonly associated with hospital-acquired infections and immunocompromised patients. Streptococcus pyogenes can cause skin infections, but Staphylococcus aureus is more frequent in this context. It's important to note that definitively diagnosing the infection would require obtaining a wound culture from a healthcare professional.

Answer 2000

The most likely diagnosis is a lesion of the trochlear nerve. The trochlear nerve (cranial nerve IV) innervates the superior oblique muscle, which is responsible for enabling the eye to look downwards and inwards. A lesion of the trochlear nerve would result in the inability to perform these movements, leading to diplopia (double vision) when attempting to look down and in. This matches the symptoms described in the patient. The other nerves and structures mentioned do not fit as well with the specific movement deficits and symptomatology described: • The abducens nerve (cranial nerve VI) innervates the lateral rectus muscle, which abducts the eye. • The ciliary ganglion is involved in pupil constriction and lens accommodation. • The nasociliary nerve is a branch of the ophthalmic nerve (V1), and is primarily involved in sensation. • The oculomotor nerve (cranial nerve III) controls most of the other extraocular muscles, except for the superior oblique and lateral rectus. Therefore, based on the inability to look downwards and inwards specifically with the right eye, the trochlear nerve lesion is the most likely diagnosis.

Answer 2001

In a heart transplant recipient, the most likely factor to increase cardiac output during moderate exercise is increased atrial filling. Here’s why the other factors are less likely to increase cardiac output in this context: • Decreased negative intrathoracic pressure: This would typically decrease venous return to the heart, which would not favor an increase in cardiac output. • Decreased venous tone: This would lead to less venous return and thus less filling of the heart, not more. • Decreased ventricular compliance: This would make the heart less able to fill properly, thereby decreasing cardiac output. • Increased intrapericardial pressure: This would compress the heart and limit its ability to fill, reducing cardiac output. Increased atrial filling leads to an increased preload, which, according to the Frank-Starling mechanism, can enhance cardiac output by increasing stroke volume. This is particularly important in heart transplant patients, where the heart relies more on intrinsic mechanisms to regulate cardiac output due to denervation.

Answer 2002

The correct pathological staging of his tumor is: Dukes’ C Here’s the reasoning: • Dukes’ A: The cancer is limited to the mucosa (innermost layer) of the bowel wall. • Dukes’ B: The cancer has grown through the muscle layer of the bowel wall and possibly into nearby tissues but has not spread to the lymph nodes. • Dukes’ C: The cancer has spread to one or more nearby lymph nodes, regardless of how far it has grown into the layers of the bowel wall. • Dukes’ D: The cancer has spread to distant parts of the body (metastasized). Given that the pathology report indicates that the tumor has invaded from the rectum into the mesorectum and involved two lymph nodes (out of 24 examined), it fits the criteria for Dukes’ C. The tumor has spread to nearby lymph nodes, which is the defining characteristic of Dukes’ C. The T2 N1 staging refers to the TNM (Tumor, Node, Metastasis) system: • T2: The tumor has grown into the muscularis propria but not through it. • N1: 1-3 regional lymph nodes are involved. However, based on the options given and the provided details, Dukes’ C is the correct staging.

Answer 2003

The first substance secreted in the process leading to increased renal reabsorption of sodium in response to the above injury is: Renin Here’s the reasoning: In response to a significant drop in blood pressure (as seen in this patient with a pulse rate of 110 beats/minute and blood pressure of 85/40 mmHg), the kidneys activate the renin-angiotensin-aldosterone system (RAAS) to increase blood pressure and maintain fluid balance. 1. Renin: Secreted by the juxtaglomerular cells of the kidneys in response to low blood pressure, low sodium content in the distal tubule, or sympathetic nervous system activation. 2. Renin then converts angiotensinogen (produced by the liver) into angiotensin I. 3. Angiotensin I is converted into angiotensin II by the enzyme angiotensin-converting enzyme (ACE), primarily in the lungs. 4. Angiotensin II has several effects, including vasoconstriction and stimulating the secretion of aldosterone from the adrenal cortex, which increases sodium reabsorption in the kidneys. Therefore, the process begins with the secretion of renin, which is the first step in the chain leading to increased sodium reabsorption in response to the injury and resultant hypotension.

Answer 2004

Deficiency of Vitamin C (ascorbic acid) results in collagen that is unstable. Vitamin C is crucial for the hydroxylation of proline and lysine residues in collagen. These hydroxylation reactions are necessary for the proper cross-linking and stability of collagen fibers. Without sufficient Vitamin C, the collagen produced is defective and weak, leading to issues in wound healing and overall tissue integrity. This condition is known as scurvy.

Answer 2005

Deficiency of Vitamin C (ascorbic acid) results in collagen that is unstable. Vitamin C is crucial for the hydroxylation of proline and lysine residues in collagen. These hydroxylation reactions are necessary for the proper cross-linking and stability of collagen fibers. Without sufficient Vitamin C, the collagen produced is defective and weak, leading to issues in wound healing and overall tissue integrity. This condition is known as scurvy.

Answer 2006

The first lymph node to which the tumor is most likely to metastasize is the: Sentinel node The sentinel node is the first lymph node to which cancer cells are most likely to spread from a primary tumor. It is identified because it is the initial node in the lymphatic drainage path from the tumor site. In breast cancer, identifying and examining the sentinel node helps determine the extent of cancer spread and guides treatment decisions.

Answer 2007

The true statement with relation to cardiac muscle is: b. Contraction is triggered by an influx of Ca through the sarcolemma Here’s why the other statements are not true: • a. Contraction does not involve release of Ca by the sarcoplasmic reticulum: This is false. Cardiac muscle contraction does involve the release of calcium from the sarcoplasmic reticulum. The initial influx of calcium through the sarcolemma triggers further release of calcium from the sarcoplasmic reticulum in a process known as calcium-induced calcium release (CICR). • c. Excitation is passed from one cardiac cell to another through desmosomes: This is false. Excitation is passed from one cardiac cell to another through gap junctions, not desmosomes. Gap junctions allow for the direct electrical communication between cardiac muscle cells. • d. Hypertrophy is brought about by division of existing cardiac cells: This is false. Cardiac hypertrophy (an increase in the size of cardiac cells) is not due to cell division but rather due to the enlargement of existing cardiac cells. • e. There is capacity for regeneration: This is largely false. Cardiac muscle cells have very limited capacity for regeneration. Most cardiac repair is due to fibrosis and scarring rather than regeneration of cardiac muscle cells.

Answer 2008

The tumor pressing directly on the conus medullaris is most likely to be located at: L1/L2 The conus medullaris, the tapered end of the spinal cord, typically ends at the level of the L1 or L2 vertebrae in adults. Compression at this level would explain the urinary retention and decreased anal and rectal tone observed in the patient, which are symptoms of conus medullaris syndrome.

Answer 2009

The most likely diagnosis for a 26-year-old man with a two-month history of unilateral testicular swelling, a heterogeneous mass within the testis with surrounding fluid on ultrasound, and elevated alpha fetoprotein (AFP) level is: Teratoma Explanation: • Testicular teratomas are germ cell tumors that can present with a heterogeneous mass and elevated levels of alpha fetoprotein (AFP). • Lymphoma typically does not elevate AFP and often presents in older men. • Orchitis, an inflammation of the testis, usually presents with pain and is not associated with elevated AFP. • Seminomas are also a type of germ cell tumor but typically do not cause an elevation in AFP; they usually elevate beta-hCG. • Tuberculosis of the testis is rare and would not typically cause elevated AFP. Thus, the combination of a testicular mass and elevated AFP levels strongly suggests a diagnosis of teratoma.

Answer 2010

The nerve likely to have been damaged in labor resulting in faecal incontinence and a relatively lax anal sphincter is the pudendal nerve. The pudendal nerve is crucial for maintaining the tone of the external anal sphincter. Damage to this nerve during prolonged and difficult labor can result in weakness or laxity of the sphincter, leading to incontinence issues.

Answer 2011

The most likely cause of the patient’s abnormal renal function is rhabdomyolysis. Here’s why: • Rhabdomyolysis occurs when muscle tissue breaks down and releases myoglobin into the bloodstream, which can cause kidney damage. • The presence of dark brown urine and a positive dipstick for myoglobin suggests muscle breakdown. • The patient’s recent femoral artery embolus and subsequent surgery likely caused ischemia to the leg muscles, leading to muscle necrosis and release of myoglobin. • Elevated urea and creatinine levels indicate acute kidney injury, which can be secondary to rhabdomyolysis. • Although the patient is a diabetic and takes ibuprofen, which can contribute to renal issues, the acute presentation and clinical context point more strongly towards rhabdomyolysis as the primary cause.

Answer 2012

The biopsy is most likely to show candida esophagitis. Here’s why: • The presence of multiple white plaques on the mucosal surface of the esophagus is characteristic of candida esophagitis. • Candida esophagitis is a common infection in immunocompromised individuals, including elderly patients and those on antibiotics, which can disrupt normal flora and allow candida overgrowth. • The patient’s history of partial gastrectomy may also contribute to altered esophageal environment, further predisposing her to candida infection. Other conditions, such as acid reflux esophagitis, Barrett’s esophagitis, eosinophilic esophagitis, and herpes esophagitis, have different characteristic endoscopic and histological features. Candida esophagitis is specifically associated with white plaques.

Answer 2013

Based on the additional information provided, the correct answer for the immediate intervention in this scenario should be: e) Tracheal intubation Explanation: Given that the patient has a respiratory rate of only 6 breaths per minute, which is extremely low and indicative of life-threatening respiratory failure, tracheal intubation and mechanical ventilation are likely necessary as the immediate intervention. While administering intravenous naloxone (option c) was initially the appropriate response to reverse the respiratory depression caused by the morphine overdose, a respiratory rate as low as 6 breaths per minute suggests that more aggressive airway management and ventilatory support are required. Intubation will secure the patient's airway and allow for mechanical ventilation to take over the work of breathing and ensure adequate oxygenation and ventilation until the naloxone takes effect and the patient's respiratory drive improves. The other options, such as high-flow oxygen (option a), intravenous fluid replacement (option b), and ECG monitoring (option d), are supportive measures but do not directly address the critical need for airway protection and ventilatory support in this case. Therefore, based on the information provided, the correct immediate intervention for a patient with a respiratory rate of 6 breaths per minute due to a morphine overdose is tracheal intubation (option e).

Answer 2014

The drug that does not reduce the rate of myocardial infarction and stroke in patients with peripheral vascular disease is oxypentifylline (also known as pentoxifylline). Here’s why: • ACE inhibitors, antihypertensive medications, aspirin, and cholesterol-lowering drugs (such as statins) have all been shown to reduce the risk of myocardial infarction (MI) and stroke by managing blood pressure, reducing clot formation, and lowering cholesterol levels. • Pentoxifylline is used to improve blood flow in peripheral vascular disease by decreasing blood viscosity and improving red blood cell flexibility, but it does not have the same evidence supporting a reduction in the rates of MI and stroke as the other medications listed. Therefore, e. oxypentifylline is the correct answer.

Answer 2015

The ligament that holds the radial head in place at the proximal radio-ulnar joint is the annular ligament. Here’s why: • The annular ligament encircles the head of the radius and keeps it in place against the ulna, allowing the radius to rotate during pronation and supination of the forearm. • The injury described is consistent with a “nursemaid’s elbow” (radial head subluxation), which occurs when the radial head slips out of the annular ligament, typically due to a sudden pull on the extended arm. Therefore, the correct answer is a. Annular ligament.

Answer 2016

The most likely responsible structure is the nucleus pulposus. Here’s why: • The symptoms described, including low back pain, pain and weakness in the left leg, numbness over the posterior aspect of the left calf extending to the lateral aspect of the foot, and absent left ankle reflex, are indicative of S1 radiculopathy. • Compression of the S1 nerve root is often due to a herniated intervertebral disc. • The nucleus pulposus, the inner gel-like core of the intervertebral disc, can herniate through the annulus fibrosus and compress adjacent nerve roots, leading to the symptoms described. Therefore, the correct answer is nucleus pulposus.

Answer 2017

The most likely composition of the man’s ureteric stone is calcium oxalate. Here’s why: • Calcium oxalate stones are the most common type of kidney and ureteric stones and are typically radiodense, meaning they appear white on X-rays and other imaging studies. • The description of a radiodense opacity on intravenous urography fits well with calcium oxalate stones. Other types of stones: • Ammonium magnesium phosphate (struvite) stones: These are less common and usually associated with urinary tract infections. They can also appear radiodense but are less common than calcium oxalate stones. • Cholesterol stones: These are rare in the urinary tract and are more commonly associated with gallstones, and they are not radiodense. • Cysteine stones: These are less common and usually occur in people with a genetic disorder called cystinuria. They can appear radiodense but are much rarer. • Urate stones: These are usually radiolucent (not visible on plain X-ray) and typically require other imaging techniques for detection. Therefore, the correct answer is b. Calcium oxalate.

Answer 2018

The most likely injury is a biceps femoris tear. Here’s why: • The biceps femoris is part of the hamstring muscle group, which is located in the posterior thigh. • The biceps femoris has two parts: the long head and the short head. The long head originates from the ischial tuberosity, while the short head originates from the lateral lip of the linea aspera on the femur, and they both insert on the head of the fibula. • Hamstring injuries, especially to the biceps femoris, are common in sports involving sprinting. • The pain described in the lower lateral posterior thigh and the inability to fully extend the knee due to pain are consistent with a biceps femoris tear, particularly because this muscle is located laterally within the hamstring group. Therefore, the correct answer is biceps femoris tear.

Answer 2019

The most likely cause of his cardiac arrest 15 minutes later is cardiac tamponade. Here’s why: • The patient has symptoms of a penetrating chest injury with signs of shock (tachycardia and hypotension), and jugular venous distension (congested neck veins). • The normal breath sounds rule out tension pneumothorax, which would typically present with decreased breath sounds on the affected side. • Cardiac tamponade is a common and critical complication of penetrating chest trauma, where blood or fluid accumulates in the pericardial sac, compressing the heart and impairing its ability to pump effectively. • This condition can rapidly progress to cardiac arrest if not treated promptly. Therefore, the correct answer is a. Cardiac tamponade.

Answer 2020

The appropriate pathological designation for this lesion is teratoma. Here’s why: • A teratoma is a type of germ cell tumor that can contain several different types of tissue, such as hair, muscle, fat, thyroid, and neural tissue, as described in the histological findings. • The presence of a cyst lined by keratinizing stratified squamous epithelium, along with areas of various tissues, is characteristic of a mature cystic teratoma (also known as a dermoid cyst). Therefore, the correct answer is e. Teratoma.

Answer 2021

The most likely anatomical structure responsible for this bleeding is the vertebral venous plexus. Here’s why: • The vertebral venous plexus, also known as Batson’s plexus, is a network of veins located in the epidural space of the spinal column. • It is common for this plexus to be inadvertently punctured during a lumbar puncture, leading to a “traumatic tap” where blood is initially present in the CSF sample. • The fact that the bleeding clears by the final collection bottle suggests that the source of the blood is from a superficial structure rather than from within the subarachnoid space. Therefore, the correct answer is e. Vertebral venous plexus.

Answer 2022

The most likely diagnosis is medullary thyroid carcinoma. Here’s why: • Medullary thyroid carcinoma (MTC) is associated with elevated serum calcitonin levels, as it arises from the parafollicular C-cells of the thyroid which produce calcitonin. • The presence of amyloid stroma on fine needle aspiration cytology is characteristic of medullary thyroid carcinoma. • The familial occurrence of similar thyroid swellings suggests a hereditary form of MTC, such as multiple endocrine neoplasia type 2 (MEN 2). Therefore, the correct answer is c. Medullary thyroid carcinoma.

Answer 2023

Given the patient’s rapid collapse and severe hypotension shortly after urinary catheterization, it is important to consider the timing and nature of the reaction. While a vasovagal response is common immediately during or after a procedure, a severe reaction occurring 30 minutes later is more suggestive of a systemic response such as anaphylaxis due to a latex allergy. Latex allergy can cause anaphylactic shock, which presents with: • Rapid onset of symptoms, including hypotension (74/34 mmHg) and tachycardia (heart rate of 128 beats/minute). • Symptoms that can develop minutes to an hour after exposure to latex. Given the timing (30 minutes after catheterization) and severity of the symptoms, latex allergy causing anaphylactic shock is a strong consideration. Therefore, the correct answer is c. Latex allergy.

Answer 2024

The most important prognostic indicator for a basal cell carcinoma (BCC) is the completeness of excision. Here’s why: • Completeness of excision is crucial because BCCs have a high likelihood of local recurrence if not entirely removed. Ensuring that the surgical margins are clear (i.e., no residual tumor cells are left at the edges of the resected tissue) is the best way to prevent recurrence and achieve a cure. • Other factors, such as the clinical pathological type, intensity of lymphocytic infiltrate, lymphovascular space invasion, and mitotic index, can provide additional information about the behavior and aggressiveness of the tumor. However, the primary determinant of the prognosis is whether the tumor has been completely excised. Therefore, the correct answer is b. Completeness of excision.

Answer 2025

The results are consistent with disseminated intravascular coagulation (DIC). Here’s why: • Low platelet count (40 x 10^9/L) and elevated INR (2.2) suggest a coagulopathy. • Elevated fibrin degradation products (25 mg/ml) and low fibrinogen level (1.5 g/L) are indicative of ongoing fibrinolysis, which is seen in DIC. • Prolonged APTT (36 seconds) further supports a coagulation disorder. • DIC is a condition characterized by widespread activation of the clotting cascade, leading to the formation of blood clots throughout the small blood vessels. This can result in multiple organ damage and is often associated with severe bleeding due to consumption of clotting factors and platelets. Therefore, the correct answer is a. Disseminated intravascular coagulation.

Answer 2026

Warfarin inhibits prothrombin. Here’s why: • Warfarin works by inhibiting the synthesis of vitamin K-dependent clotting factors, which include factors II (prothrombin), VII, IX, and X, as well as the anticoagulant proteins C and S. • This inhibition prevents the activation of these clotting factors, thereby reducing the blood’s ability to form clots. Therefore, the correct answer is d. Prothrombin.

Answer 2027

Dupuytren’s contracture is a condition affecting the palmar fascia of the hand, leading to the progressive thickening and shortening of fibrous tissue. This results in flexion deformities of the fingers, most commonly affecting the ring and little fingers. Here are some key points about Dupuytren’s contracture: Clinical Features: 1. Nodules and Cords: Palpable nodules in the palm, progressing to fibrous cords that cause the fingers to bend towards the palm. 2. Flexion Deformity: Inability to fully extend the fingers. 3. Painless: Typically painless, but can cause functional impairment. 4. Bilateral: Often affects both hands, though not symmetrically. Risk Factors: 1. Genetic Predisposition: Strong familial links, more common in individuals of Northern European descent. 2. Age and Gender: More common in older adults, particularly males. 3. Associated Conditions: Higher prevalence in patients with diabetes, epilepsy (due to medication), and alcohol dependence. Diagnosis: 1. Clinical Examination: Identification of characteristic nodules and cords, flexion deformity. 2. Tabletop Test: Inability to lay the hand flat on a table indicates contracture. Management: 1. Non-Surgical: Includes observation for mild cases, physical therapy, and steroid injections. 2. Surgical: Indicated for significant functional impairment. • Fasciectomy: Removal of the affected fascia. • Needle Aponeurotomy: Minimally invasive, using needles to break cords. • Dermofasciectomy: Removal of the skin overlying the contracture, usually with skin grafting. Prognosis: • Varies; some cases progress slowly, while others rapidly lead to significant disability. • Recurrence after surgery is common, necessitating ongoing monitoring and possible repeat procedures.

Answer 2028

Dupuytren’s contracture is a condition affecting the palmar fascia of the hand, leading to the progressive thickening and shortening of fibrous tissue. This results in flexion deformities of the fingers, most commonly affecting the ring and little fingers. Here are some key points about Dupuytren’s contracture: Clinical Features: 1. Nodules and Cords: Palpable nodules in the palm, progressing to fibrous cords that cause the fingers to bend towards the palm. 2. Flexion Deformity: Inability to fully extend the fingers. 3. Painless: Typically painless, but can cause functional impairment. 4. Bilateral: Often affects both hands, though not symmetrically. Risk Factors: 1. Genetic Predisposition: Strong familial links, more common in individuals of Northern European descent. 2. Age and Gender: More common in older adults, particularly males. 3. Associated Conditions: Higher prevalence in patients with diabetes, epilepsy (due to medication), and alcohol dependence. Diagnosis: 1. Clinical Examination: Identification of characteristic nodules and cords, flexion deformity. 2. Tabletop Test: Inability to lay the hand flat on a table indicates contracture. Management: 1. Non-Surgical: Includes observation for mild cases, physical therapy, and steroid injections. 2. Surgical: Indicated for significant functional impairment. • Fasciectomy: Removal of the affected fascia. • Needle Aponeurotomy: Minimally invasive, using needles to break cords. • Dermofasciectomy: Removal of the skin overlying the contracture, usually with skin grafting. Prognosis: • Varies; some cases progress slowly, while others rapidly lead to significant disability. • Recurrence after surgery is common, necessitating ongoing monitoring and possible repeat procedures.

Answer 2029

Rectus abdominis This structure will be the rectus sheath and when entered the rectus abdominis muscle will be encountered.

Answer 2030

Rectus abdominis This structure will be the rectus sheath and when entered the rectus abdominis muscle will be encountered. The rectus abdominis muscle is a key muscle located in the anterior abdominal wall, and it is enclosed within the rectus sheath. When performing surgical procedures involving the abdominal wall, an understanding of the rectus sheath and the anatomy of the rectus abdominis muscle is essential. Anatomy of the Rectus Abdominis Muscle and Sheath: 1. Rectus Abdominis Muscle: • This is a long, flat muscle extending vertically along the length of the anterior abdominal wall. • It is segmented by three or more tendinous intersections, giving it the characteristic “six-pack” appearance. 2. Rectus Sheath: • The rectus sheath is a fibrous compartment formed by the aponeuroses of the abdominal muscles. • It encloses the rectus abdominis muscle. • The sheath consists of an anterior and a posterior layer above the arcuate line and only an anterior layer below the arcuate line. Surgical Incisions Involving the Rectus Abdominis: Midline Incision: • The incision is made along the linea alba, which is the fibrous structure that runs down the midline of the abdomen, separating the left and right rectus abdominis muscles. • This approach avoids cutting through muscle fibers directly, thereby reducing muscle damage. Paramedian Incision: • The incision is made parallel and lateral to the midline, often used to access structures on one side of the abdomen. • After incising the skin and subcutaneous tissue, the rectus sheath is opened, and the rectus abdominis muscle is retracted laterally to gain access to the underlying structures. Transverse Incision (Pfannenstiel’s Incision): • Commonly used in gynecological and obstetric surgeries, such as Cesarean sections. • The incision is made transversely just above the pubic symphysis, through the rectus sheath and separating the rectus abdominis muscles without cutting through them. Understanding the anatomy and proper techniques for incising and handling the rectus abdominis muscle and sheath is crucial in abdominal surgeries to minimize complications and ensure optimal recovery.

Answer 2031

Boas’ sign is classically associated with acute cholecystitis. Explanation: • Boas’ sign refers to hyperesthesia (increased sensitivity) or tenderness below the right scapula. This is thought to be due to referred pain from irritation of the diaphragm, which shares nerve innervation with the area below the right scapula. • Acute cholecystitis involves inflammation of the gallbladder, often due to gallstones, and can present with right upper quadrant pain, fever, and sometimes referred pain to the right shoulder or back, where Boas’ sign may be elicited. None of the other conditions listed are classically associated with Boas’ sign.

Answer 2032

Boas’ sign is classically associated with acute cholecystitis. Explanation: • Boas’ sign refers to hyperesthesia (increased sensitivity) or tenderness below the right scapula. This is thought to be due to referred pain from irritation of the diaphragm, which shares nerve innervation with the area below the right scapula. • Acute cholecystitis involves inflammation of the gallbladder, often due to gallstones, and can present with right upper quadrant pain, fever, and sometimes referred pain to the right shoulder or back, where Boas’ sign may be elicited. None of the other conditions listed are classically associated with Boas’ sign.

Answer 2033

Boas’ sign is classically associated with acute cholecystitis. Explanation: • Boas’ sign refers to hyperesthesia (increased sensitivity) or tenderness below the right scapula. This is thought to be due to referred pain from irritation of the diaphragm, which shares nerve innervation with the area below the right scapula. • Acute cholecystitis involves inflammation of the gallbladder, often due to gallstones, and can present with right upper quadrant pain, fever, and sometimes referred pain to the right shoulder or back, where Boas’ sign may be elicited. None of the other conditions listed are classically associated with Boas’ sign.

Answer 2034

Boas’ sign is classically associated with acute cholecystitis. Explanation: • Boas’ sign refers to hyperesthesia (increased sensitivity) or tenderness below the right scapula. This is thought to be due to referred pain from irritation of the diaphragm, which shares nerve innervation with the area below the right scapula. • Acute cholecystitis involves inflammation of the gallbladder, often due to gallstones, and can present with right upper quadrant pain, fever, and sometimes referred pain to the right shoulder or back, where Boas’ sign may be elicited. None of the other conditions listed are classically associated with Boas’ sign.

Answer 2035

In the case of a pulmonary embolism, the typical arterial blood gas (ABG) results often show: 1. Hypoxia - a reduced partial pressure of oxygen (PaO2). 2. Hypocapnia - a reduced partial pressure of carbon dioxide (PaCO2), due to hyperventilation. 3. Respiratory Alkalosis - an elevated pH. This pattern is primarily due to the hyperventilation that occurs in response to the blockage in the pulmonary arteries, which limits the ability to oxygenate the blood efficiently. Consequently, the patient tends to breathe faster, expelling more CO2, leading to respiratory alkalosis . PH 7.50, рОг 7.2, рСОг 2.5, НСО3 24

Answer 2036

Where axillary nodal involvement is suspected from the outset it is important to establish whether this is the case prior to surgery. This is because, if axillary metastatic disease is present then the correct management would be an axillary node clearance and this is irrespective of the surgical plans for the breast primary. In the case of breast cancer, image guided FNAC is acceptable as it is accurate and if carcinoma cells are identified at FNA then axillary node clearance can be performed. If FNAC is negative then a sentinel node biopsy should accompany excision of the primary tumour. Where the axilla is clinically clear on palpation and imaging then a sentinel lymph node biopsy should accompany excision of the primary tumour.

Answer 2037

Where axillary nodal involvement is suspected from the outset it is important to establish whether this is the case prior to surgery. This is because, if axillary metastatic disease is present then the correct management would be an axillary node clearance and this is irrespective of the surgical plans for the breast primary. In the case of breast cancer, image guided FNAC is acceptable as it is accurate and if carcinoma cells are identified at FNA then axillary node clearance can be performed. If FNAC is negative then a sentinel node biopsy should accompany excision of the primary tumour. Where the axilla is clinically clear on palpation and imaging then a sentinel lymph node biopsy should accompany excision of the primary tumour.

Answer 2038

The correct answer is D) Hypertensive encephalopathy. Here's the explanation: The patient's symptoms, including severe headache, fever, confusion, and disorientation, are consistent with encephalitis. However, the presence of constricted and reactive pupils suggests that the patient's condition is more likely related to increased intracranial pressure rather than an infectious process. Hypertensive encephalopathy is a condition that occurs when there is a sudden and severe increase in blood pressure, leading to damage to the blood vessels and brain tissue. This can cause a range of symptoms, including headache, confusion, and altered mental status. The patient's blood pressure of 180/100 mmHg is significantly elevated, which increases the likelihood of hypertensive encephalopathy. Meningitis (option A) is an infection of the meninges, the protective membranes surrounding the brain and spinal cord. While it can cause headache, fever, and confusion, it is less likely to cause constricted pupils. Subarachnoid haemorrhage (option C) is a life-threatening condition that occurs when there is bleeding into the space surrounding the brain. While it can cause severe headache and altered mental status, it is less likely to cause constricted pupils. In summary, the patient's symptoms, particularly the constricted and reactive pupils, suggest that the most likely diagnosis is hypertensive encephalopathy, rather than encephalitis or other conditions.

Answer 2039

The patient's symptoms of dysphagia and regurgitation of food, particularly with a history of a mass in the left side of his neck, suggest a diagnosis of Zenker's diverticulum. Zenker's diverticulum is a type of esophageal diverticulum that occurs at the junction of the esophagus and pharynx, typically in the posterior wall of the pharynx. It is often caused by a combination of factors, including age, smoking, and gastroesophageal reflux disease. Carcinoma of the larynx (option A) is a type of cancer that occurs in the larynx, and while it can cause hoarseness, it is less likely to cause regurgitation of food. Carcinoma of the esophagus (option B) is a type of cancer that occurs in the esophagus, and while it can cause dysphagia, it is less likely to cause a mass in the neck. Thyroid cancer (option D) is a type of cancer that occurs in the thyroid gland, and while it can cause a mass in the neck, it is less likely to cause dysphagia and regurgitation of food. In summary, the patient's symptoms and physical examination findings suggest that the most likely diagnosis is Zenker's diverticulum, rather than carcinoma of the larynx, esophagus, or thyroid gland.

Answer 2040

The patient's symptoms of dysphagia and regurgitation of food, particularly with a history of a mass in the left side of his neck, suggest a diagnosis of Zenker's diverticulum. Zenker's diverticulum is a type of esophageal diverticulum that occurs at the junction of the esophagus and pharynx, typically in the posterior wall of the pharynx. It is often caused by a combination of factors, including age, smoking, and gastroesophageal reflux disease. Carcinoma of the larynx (option A) is a type of cancer that occurs in the larynx, and while it can cause hoarseness, it is less likely to cause regurgitation of food. Carcinoma of the esophagus (option B) is a type of cancer that occurs in the esophagus, and while it can cause dysphagia, it is less likely to cause a mass in the neck. Thyroid cancer (option D) is a type of cancer that occurs in the thyroid gland, and while it can cause a mass in the neck, it is less likely to cause dysphagia and regurgitation of food. In summary, the patient's symptoms and physical examination findings suggest that the most likely diagnosis is Zenker's diverticulum, rather than carcinoma of the larynx, esophagus, or thyroid gland.

Answer 2041

The patient's symptoms, including severe headache, fever, and stiff neck, are consistent with meningitis. Meningitis is an infection of the meninges, the protective membranes surrounding the brain and spinal cord. The patient's history of migraine and use of sumatriptan do not rule out meningitis. Encephalitis (option B) is an infection of the brain, and while it can cause headache, fever, and altered mental status, it is less likely to cause a stiff neck. Subarachnoid haemorrhage (option C) is a life-threatening condition that occurs when there is bleeding into the space surrounding the brain. While it can cause severe headache and stiff neck, it is less likely to cause a fever. Migraine (option D) is a type of headache disorder, and while it can cause headache, it is less likely to cause fever, stiff neck, and other symptoms consistent with meningitis. In summary, the patient's symptoms, particularly the stiff neck, suggest that the most likely diagnosis is meningitis, rather than encephalitis, subarachnoid haemorrhage, or migraine.

Answer 2042

The patient's symptoms, including worsening confusion, agitation, and hallucinations, are consistent with neuroleptic malignant syndrome (NMS). NMS is a rare but life-threatening condition that occurs when antipsychotic medications, such as risperidone, cause a hyperthermic reaction. This can lead to a range of symptoms, including confusion, agitation, hallucinations, and autonomic instability. Anticholinergic toxicity (option C) is a condition that occurs when anticholinergic medications, such as antihistamines or antidepressants, cause a range of symptoms, including confusion, agitation, and hallucinations. While it can cause similar symptoms to NMS, it is less likely to cause a hyperthermic reaction. Serotonin syndrome (option B) is a condition that occurs when there is an excessive amount of serotonin in the body, often caused by the use of certain medications, such as antidepressants. While it can cause symptoms such as confusion, agitation, and hallucinations, it is less likely to cause a hyperthermic reaction. Delirium (option D) is a condition that occurs when there is a sudden change in mental status, often caused by a medical condition or medication. While it can cause symptoms such as confusion, agitation, and hallucinations, it is less likely to cause a hyperthermic reaction. In summary, the patient's symptoms, particularly the worsening confusion, agitation, and hallucinations, suggest that the most likely diagnosis is neuroleptic malignant syndrome, rather than anticholinergic toxicity, serotonin syndrome, or delirium.

Answer 2043

The patient's symptoms, including worsening weakness and numbness in her left arm and leg, are consistent with a relapse of multiple sclerosis. However, the patient's history of multiple sclerosis and the use of interferon beta-1a, a disease-modifying therapy, suggest that the symptoms may be related to an acute event rather than a relapse. Acute disseminated encephalomyelitis (ADEM) is a rare condition that occurs when there is an abnormal immune response to a viral or bacterial infection, leading to inflammation and damage to the central nervous system. ADEM can cause a range of symptoms, including weakness, numbness, and vision changes, which are consistent with the patient's symptoms. Transverse myelitis (option B) is a condition that occurs when there is inflammation of the spinal cord, often caused by a viral or bacterial infection. While it can cause weakness and numbness in the arms and legs, it is less likely to cause a relapse of multiple sclerosis. Guillain-Barré syndrome (option D) is a condition that occurs when there is an abnormal immune response to a viral or bacterial infection, leading to inflammation and damage to the peripheral nervous system. While it can cause weakness and numbness in the arms and legs, it is less likely to cause a relapse of multiple sclerosis. In summary, the patient's symptoms, particularly the worsening weakness and numbness in her left arm and leg, suggest that the most likely diagnosis is acute disseminated encephalomyelitis, rather than multiple sclerosis relapse, transverse myelitis, or Guillain-Barré syndrome.

Answer 2044

Median nerve This is a common injury in children. In this case the angulation and displacement have resulted in median nerve injury.

Answer 2045

Median nerve This is a common injury in children. In this case the angulation and displacement have resulted in median nerve injury.

Answer 2046

Pisiform This small bone has a single articular facet. It projects from the triquetral bone at the ulnar aspect of the wrist where most regard it as a sesamoid bone lying within the tendon of flexor carpi ulnaris.

Answer 2047

Pisiform This small bone has a single articular facet. It projects from the triquetral bone at the ulnar aspect of the wrist where most regard it as a sesamoid bone lying within the tendon of flexor carpi ulnaris.

Answer 2048

Scaphoid fracture FOOSH is a common mechanism of injury for a scaphoid fracture. This should be suspected clinically if there is tenderness in the base of the anatomical snuffbox. A tendon rupture would not result in bony tenderness.

Answer 2049

Scaphoid fracture FOOSH is a common mechanism of injury for a scaphoid fracture. This should be suspected clinically if there is tenderness in the base of the anatomical snuffbox. A tendon rupture would not result in bony tenderness.

Answer 2050

Biceps brachii Biceps inserts into the radial tuberosity. Distal injuries of this muscle are rare but are reported and are clinically more important than more proximal ruptures.

Answer 2051

Biceps brachii Biceps inserts into the radial tuberosity. Distal injuries of this muscle are rare but are reported and are clinically more important than more proximal ruptures.

Answer 2052

Pronator teres (deep head) The ulnar artery lies deep to pronator teres and this separates it from the median nerve.

Answer 2053

Pronator teres (deep head) The ulnar artery lies deep to pronator teres and this separates it from the median nerve.

Answer 2054

Correct Answer: B) At end inspiration Explanation: During inspiration, the diaphragm contracts and the thoracic cavity expands, which lowers the intrathoracic and pleural pressures tofacilitate air entry into the lungs. At the end of inspiration, pleural pressure reaches its most negative value relative to atmospheric pressure, aiding in lung inflation. Why Other Options Are Incorrect: • A) At end expiration: Although pleural pressure remains negative, it is less negative compared to end inspiration, as the diaphragm relaxes, and lung volume is reduced. • C) During a Valsalva maneuver: During this maneuver, pleural pressure becomes positive due to increased intrathoracic pressure from the forced expiration against a closed glottis. • D) During forced expiration: Pleural pressure may briefly become positive during forced expiration, as it raises intrathoracic pressure to expel air from the lungs actively. • E) When lying supine: While lying supine affects lung mechanics and reduces functional residual capacity, it does not significantly alter pleural pressure to make it as negative as during end inspiration.

Answer 2055

Correct Answer: B) At end inspiration Explanation: During inspiration, the diaphragm contracts and the thoracic cavity expands, which lowers the intrathoracic and pleural pressures tofacilitate air entry into the lungs. At the end of inspiration, pleural pressure reaches its most negative value relative to atmospheric pressure, aiding in lung inflation. Why Other Options Are Incorrect: • A) At end expiration: Although pleural pressure remains negative, it is less negative compared to end inspiration, as the diaphragm relaxes, and lung volume is reduced. • C) During a Valsalva maneuver: During this maneuver, pleural pressure becomes positive due to increased intrathoracic pressure from the forced expiration against a closed glottis. • D) During forced expiration: Pleural pressure may briefly become positive during forced expiration, as it raises intrathoracic pressure to expel air from the lungs actively. • E) When lying supine: While lying supine affects lung mechanics and reduces functional residual capacity, it does not significantly alter pleural pressure to make it as negative as during end inspiration.

Answer 2056

This patient has hypovolemia and shock due to significant blood loss (20 units of blood transfused, low urine output, hypotension, and low skin turgor). These conditions activate the renin-angiotensin system (RAS), which is responsible for maintaining blood pressure and perfusion, particularly in hypovolemic states. Here’s how it works: 1. Reduced perfusion pressure in the afferent arteriole of the kidney is sensed by the juxtaglomerular cells. 2. This triggers the release of renin by the juxtaglomerular apparatus. 3. Renin converts angiotensinogen (produced by the liver) into angiotensin I. 4. Angiotensin I is converted to angiotensin II by angiotensin-converting enzyme (ACE), primarily in the lungs. 5. Angiotensin II has multiple effects: • Vasoconstriction to increase systemic vascular resistance and blood pressure. • Stimulation of aldosterone release from the adrenal cortex, which promotes sodium and water retention in the kidneys, increasing blood volume. • Stimulation of thirst, further contributing to blood volume restoration. Correct answer: Increased renin release with increased angiotensin II and aldosterone activity. This response helps counteract the effects of hypovolemia and hypotension, attempting to restore perfusion and maintain homeostasis.

Answer 2057

This patient has hypovolemia and shock due to significant blood loss (20 units of blood transfused, low urine output, hypotension, and low skin turgor). These conditions activate the renin-angiotensin system (RAS), which is responsible for maintaining blood pressure and perfusion, particularly in hypovolemic states. Here’s how it works: 1. Reduced perfusion pressure in the afferent arteriole of the kidney is sensed by the juxtaglomerular cells. 2. This triggers the release of renin by the juxtaglomerular apparatus. 3. Renin converts angiotensinogen (produced by the liver) into angiotensin I. 4. Angiotensin I is converted to angiotensin II by angiotensin-converting enzyme (ACE), primarily in the lungs. 5. Angiotensin II has multiple effects: • Vasoconstriction to increase systemic vascular resistance and blood pressure. • Stimulation of aldosterone release from the adrenal cortex, which promotes sodium and water retention in the kidneys, increasing blood volume. • Stimulation of thirst, further contributing to blood volume restoration. Correct answer: Increased renin release with increased angiotensin II and aldosterone activity. This response helps counteract the effects of hypovolemia and hypotension, attempting to restore perfusion and maintain homeostasis.

Answer 2058

The brachial plexus is formed by the ventral rami of specific spinal nerve roots. The standard nerve roots contributing to the brachial plexus are **C5 to T1**. Here's the breakdown: - **C5-T1** (Option C) is the correct answer. - The brachial plexus typically arises from the **lower cervical (C5-C8)** and **first thoracic (T1)** spinal nerves. - Variations like contributions from C4 (prefixed plexus) or T2 (postfixed plexus) exist but are not considered standard. - Other options (A, B, D) include incorrect or non-standard nerve roots (e.g., C3, T2, or missing C5). **Answer:** **C. C5-T1**

Answer 2059

The brachial plexus is formed by the ventral rami of specific spinal nerve roots. The standard nerve roots contributing to the brachial plexus are **C5 to T1**. Here's the breakdown: - **C5-T1** (Option C) is the correct answer. - The brachial plexus typically arises from the **lower cervical (C5-C8)** and **first thoracic (T1)** spinal nerves. - Variations like contributions from C4 (prefixed plexus) or T2 (postfixed plexus) exist but are not considered standard. - Other options (A, B, D) include incorrect or non-standard nerve roots (e.g., C3, T2, or missing C5). **Answer:** **C. C5-T1**

Answer 2060

**Answer:** **d. It provides attachment for both heads of biceps** ### Explanation: 1. **Option a**: Incorrect. The scapula overlies the **2nd to 7th ribs**, not the 9th. 2. **Option b**: Incorrect. The scapular spine continues laterally as the **acromion** (not the coracoid process). The coracoid process projects anteriorly. 3. **Option c**: Incorrect. The **suprascapular notch** is located on the **superior border** of the scapula, not the spine. 4. **Option d**: **Correct**. The scapula provides attachment for both heads of the biceps brachii: - **Long head**: Originates from the supraglenoid tubercle. - **Short head**: Originates from the coracoid process. 5. **Option e**: While true (most scapular fractures involve the body), this is a **clinical fact** rather than a defining anatomical feature. The question asks for the "best describes" statement, prioritizing structural/functional anatomy over pathology. **Conclusion**: Option **d** is the most accurate anatomical description of the scapula.

Answer 2061

**Answer:** **d. It provides attachment for both heads of biceps** ### Explanation: 1. **Option a**: Incorrect. The scapula overlies the **2nd to 7th ribs**, not the 9th. 2. **Option b**: Incorrect. The scapular spine continues laterally as the **acromion** (not the coracoid process). The coracoid process projects anteriorly. 3. **Option c**: Incorrect. The **suprascapular notch** is located on the **superior border** of the scapula, not the spine. 4. **Option d**: **Correct**. The scapula provides attachment for both heads of the biceps brachii: - **Long head**: Originates from the supraglenoid tubercle. - **Short head**: Originates from the coracoid process. 5. **Option e**: While true (most scapular fractures involve the body), this is a **clinical fact** rather than a defining anatomical feature. The question asks for the "best describes" statement, prioritizing structural/functional anatomy over pathology. **Conclusion**: Option **d** is the most accurate anatomical description of the scapula.

Answer 2062

ANSWER: E - The subcostal neurovascular bundle is relatively protected from risk of injury The subcostal neurovascular bundle is relatively protected from risk of injury because it lies in the costal groove. The renal fascia of Gerota surrounds the perinephric fat, which lies outside the renal capsule. The renal artery is posterior to the renal vein. The adrenal glands are anatomically well protected. They lie anterosuperior to the upper part of each kidney, within their own compartment of the renal fascia. Care must be taken during a nephrectomy to avoid damage to the adrenals, but these are not easily damaged by a careful surgeon using a posterior approach. The lower border of the parietal pleura crosses the twelfth rib at the lateral border of the erector spinae, and passes in horizontally to the lower border of the twelfth thoracic vertebrae. There is, therefore, a triangle of pleura in the costovertebral angle below the medial part of the twelfth rib, behind the upper pole of the kidney

Answer 2063

ANSWER: E - The subcostal neurovascular bundle is relatively protected from risk of injury The subcostal neurovascular bundle is relatively protected from risk of injury because it lies in the costal groove. The renal fascia of Gerota surrounds the perinephric fat, which lies outside the renal capsule. The renal artery is posterior to the renal vein. The adrenal glands are anatomically well protected. They lie anterosuperior to the upper part of each kidney, within their own compartment of the renal fascia. Care must be taken during a nephrectomy to avoid damage to the adrenals, but these are not easily damaged by a careful surgeon using a posterior approach. The lower border of the parietal pleura crosses the twelfth rib at the lateral border of the erector spinae, and passes in horizontally to the lower border of the twelfth thoracic vertebrae. There is, therefore, a triangle of pleura in the costovertebral angle below the medial part of the twelfth rib, behind the upper pole of the kidney

Answer 2064

ANSWER: A Cremasteric artery Nine structures lie within the spermatic cord: three arteries (testicular, cremasteric, artery to the vas deferens); three nerves (genital branch of the genitofemoral nerve, sympathetic fibres, ilioinguinal nerve - this is outside the cord but travels with it and three other structures (pampiniform plexus, vas deferences, lymphatics). There are three covering fascial layers - external and internal spermatic and cremasteric fascia. The external spermatic fascia is a thin membrane covering the spermatic cord and is derived from the aponeurosis of the external oblique. It surrounds but is not contained within the cord. The ilioinguinal nerve travels within the inguinal canal but not within the spermatic cord. The genital branch of the genitofemoral nerve travels within the spermatic cord rather than the femoral branch. Lipomas of the cord are sometimes found during inguinal hernia repairs but they are not contained within the cord.

Answer 2065

ANSWER: В Intercrural fibres The visible landmark for the superficial inguinal ring are the intercrural fibres that run at right angles across the external oblique aponeurosis. The inguinal canal with its borders is shown in the image below, with the deep inguinal ring seen laterally and the superficial ring seen medially at either end. The superficial inguinal ring is a triangular hiatus in the external oblique aponeurosis. These form the posterior wall of the inguinal canal - the transversalis fascia laterally and the conjoint tendon medially. The ilioinguinal nerve travels through the inguinal canal with the spermatic cord but not inside it. The inferior epigastric vessels are medial to the deep inguinal ring

Answer 2066

ANSWER: В Intercrural fibres The visible landmark for the superficial inguinal ring are the intercrural fibres that run at right angles across the external oblique aponeurosis. The inguinal canal with its borders is shown in the image below, with the deep inguinal ring seen laterally and the superficial ring seen medially at either end. The superficial inguinal ring is a triangular hiatus in the external oblique aponeurosis. These form the posterior wall of the inguinal canal - the transversalis fascia laterally and the conjoint tendon medially. The ilioinguinal nerve travels through the inguinal canal with the spermatic cord but not inside it. The inferior epigastric vessels are medial to the deep inguinal ring

Answer 2067

ANSWER: A Camper's fascia The superficial fascia of the anterior abdominal wall is divided into a superficial adipose layer known as Camper's fascia and a deeper membranous layer known as Scarpa's fascia. Camper's fascia is fatty to varying degrees and is the more superficial, and therefore is the correct answer here. The layers of the anterior abdominal wall are: skin, subcutaneous tissue, superficial fascia (Camper's fascia and Scarpa's fascia), external oblique muscle, internal oblique muscle, transversus abdominis muscle, transversalis fascia, preperitoneal fatty tissue,and peritoneum. These are clinically important to know for all abdominal surgery. Scarpa's fascia is the deeper layer to Camper's fascia and is thin and membranous. It contains very little, or no, fat and so is not the correct answer here. Scarpa's fascia continues below the inguinal ligament and fuses with the fascia lata of the thigh. It also forms the fundiform ligament of the penis and is known as Colle's fascia once it advances posteriorly along the perineum. Colle's fascia is the continuation of Scarpa's fascia in the perineum. It is the deeper membranous layer of the superficial perineal fascia. It attaches to the ischiopubic rami and the perineal membrane, which divides the prostate from the base of the penis. The Dartos fascia is the continuation of Scarpa's fascia into the scrotum. It contains smooth muscle fibres. The fascia lata is the deep fascia of the thigh and surrounds the muscles of the thigh. Scarpa's fascia fuses with the fascia lata just under the inguinal ligament.

Answer 2068

ANSWER: C llioinguinal nerve The ilioinguinal nerve is a branch of the first lumbar nerve and accompanies the spermatic cord through the inguinal canal, exiting through the superficial inguinal ring. It is commonly seen overlying the cord, rather than within it. The testicular artery is found in the spermatic cord and is one of three arteries that travels within it. A paired artery, it branches directly on each side from the abdominal aorta, below the origin of the renal arteries and passes downwards on the anterior surface of the psoas major to supply the testes. The cremasteric artery is found in the spermatic cord and is one of the three arteries travelling within it. It is a branch of the inferior epigastric artery and supplies the cremaster muscle and scrotal skin. The pampiniform plexus is a network of veins found within the spermatic cord. It provides venous return from the testes and plays a part in testicular temperature regulation. A varicocele is an abnormal enlargement of this structure. The vas deferens is a muscular structure that does run within the spermatic cord and transports sperm from the epididymis to the ejaculatory duct. If inadvertently damaged during a hernia repair, it may contribute to infertility and the patient must be counselled regarding this during the consent process

Answer 2069

ANSWER: C llioinguinal nerve The ilioinguinal nerve is a branch of the first lumbar nerve and accompanies the spermatic cord through the inguinal canal, exiting through the superficial inguinal ring. It is commonly seen overlying the cord, rather than within it. The testicular artery is found in the spermatic cord and is one of three arteries that travels within it. A paired artery, it branches directly on each side from the abdominal aorta, below the origin of the renal arteries and passes downwards on the anterior surface of the psoas major to supply the testes. The cremasteric artery is found in the spermatic cord and is one of the three arteries travelling within it. It is a branch of the inferior epigastric artery and supplies the cremaster muscle and scrotal skin. The pampiniform plexus is a network of veins found within the spermatic cord. It provides venous return from the testes and plays a part in testicular temperature regulation. A varicocele is an abnormal enlargement of this structure. The vas deferens is a muscular structure that does run within the spermatic cord and transports sperm from the epididymis to the ejaculatory duct. If inadvertently damaged during a hernia repair, it may contribute to infertility and the patient must be counselled regarding this during the consent process

Answer 2070

ANSWER: E Sigmoid colon The sigmoid colon is suspended in the mesentery and is found within the peritoneal cavity. The organs of the abdominal cavity can be classified as intraperitoneal or retroperitoneal according to their relationship with the peritoneal membrane. Intraperitoneal organs are those that are within the peritoneal space and lined with peritoneum, and retroperitoneal are those that lie behind the space and are not lined with peritoneum. These organs are mainly close to the posterior wall of the abdomen. The descending part of the duodenum is the second part of the duodenum and is retroperitoneal. Only the proximal first segment of the duodenum is intraperitoneal. he ascending part of the duodenum is the fourth part and is the longest section. It is crossed by the superior mesenteric artery and vein and is a retroperitoneal structure. The inferior vena cava lies posteriorly to the main abdominal cavity and is therefore a retroperitoneal structure. Suprarenal glands, these endocrine glands produce varying hormones and are retroperitoneal glands, sitting on top of the kidneys and surrounded by Gerota's fascia.

Answer 2071

ANSWER: B Major duodenal papilla The foregut begins at the mouth and ends just inferior to the major duodenal papilla, where it gives way to the midgut. he SMA originates from the anterior abdominal aorta anterior to L1. It supplies the midgut, which begins inferior to the major duodenal papilla. The head of the pancreas is closely related to the duodenum as it lies within its concavity. The major duodenal papilla, below which point the foregut ends and midgut begins, is the point at which the common bile duct and pancreatic duct empty into the duodenum. Therefore, the head of the pancreas is closely related to the junction between foregut and midgut but the major duodenal papilla is a more accurate answer. The distal third of the transverse colon is the point at which the hindgut begins and is not related to the foregut and midgut. The coeliac trunk arises from the abdominal aorta immediately below the hiatus of the diaphragm at T12. It originates just above the superior mesenteric artery and supplies the foregut but is not related to the junction of the foregut and midgut.

Answer 2072

ANSWER: B Major duodenal papilla The foregut begins at the mouth and ends just inferior to the major duodenal papilla, where it gives way to the midgut. he SMA originates from the anterior abdominal aorta anterior to L1. It supplies the midgut, which begins inferior to the major duodenal papilla. The head of the pancreas is closely related to the duodenum as it lies within its concavity. The major duodenal papilla, below which point the foregut ends and midgut begins, is the point at which the common bile duct and pancreatic duct empty into the duodenum. Therefore, the head of the pancreas is closely related to the junction between foregut and midgut but the major duodenal papilla is a more accurate answer. The distal third of the transverse colon is the point at which the hindgut begins and is not related to the foregut and midgut. The coeliac trunk arises from the abdominal aorta immediately below the hiatus of the diaphragm at T12. It originates just above the superior mesenteric artery and supplies the foregut but is not related to the junction of the foregut and midgut.

Answer 2073

ANSWER: C The portal vein receives tributaries including the right and left gastric veins and para-umbilical veins This is correct, and the portal vein also receives cystic veins from the gall-bladder. The portal vein is formed by the union of the splenic vein and superior mesenteric veins posterior to the neck of the pancreas. It runs along with the hepatic artery proper and common bile duct to form the three components of the portal triad. The hepatoduodenal ligament is a double form the three components of the portal triad. The hepatoduodenal ligament is a double layer of peritoneum - the free edge of the lesser omentum - that encompasses the triad. This is clinically relevant in liver surgery where the hepatoduodenal ligament may be clamped with a large atraumatic haemostat to halt blood flow and control bleeding from the liver. This is known as the Pringle manoeuvre. Although the portal vein forms posterior to the neck of the pancreas, it is formed by the union of the splenic vein and the superior mesenteric vein. The portal vein is formed at the L1 level. The portal vein passes posterior to the superior part of the duodenum but does enter the right edge of the lesser omentum. The portal vein passes posteriorly to both these structures.

Answer 2074

ANSWER: C The ureterovesical junction This is the point at which the ureters enter the wall of the bladder, and is a site of ureterall constriction at which renal stones may lodge. It is the most common site of impaction as it has the smallest diameter of the options listed. Generally for a stone to impact it must have a diameter of 2 mm or greater. Ureteropelvic junction is the point at which the renal pelvis becomes continues with the ureter and is the first point of constriction at which renal stones can become lodged. Ureteral crossing of the iliac vessels, at the point at which the ureters cross the common iliac vessels the ureters are slightly constricted. Stones lodged here are more unusual than stones lodged at the ureteropelvic or ureterovesical junction. The ureters do not cross the renal veins. The prostatic urethra is the widest part of the urethra, so an unlikely site for obstruction.

Answer 2075

ANSWER: C The ureterovesical junction This is the point at which the ureters enter the wall of the bladder, and is a site of ureterall constriction at which renal stones may lodge. It is the most common site of impaction as it has the smallest diameter of the options listed. Generally for a stone to impact it must have a diameter of 2 mm or greater. Ureteropelvic junction is the point at which the renal pelvis becomes continues with the ureter and is the first point of constriction at which renal stones can become lodged. Ureteral crossing of the iliac vessels, at the point at which the ureters cross the common iliac vessels the ureters are slightly constricted. Stones lodged here are more unusual than stones lodged at the ureteropelvic or ureterovesical junction. The ureters do not cross the renal veins. The prostatic urethra is the widest part of the urethra, so an unlikely site for obstruction.

Answer 2076

ANSWER: A-Obturator internus *The tendon of the obturator internus leaves the pelvic cavity by passing through the lesser sciatic foramen, wrapping around the lesser sciatic notch, changing direction by about 90 degrees. It is joined there by the superior and inferior gemelli and inserts with them on the upper portion of the greater trochanter. •The obturator externus arises on the external surface of the pubic bone and obturator membrane and inserts on the greater trochanter. *The quadratus femoris arises from the ischial tuberosity and inserts on the intertrochanteric line of the femur. •The gluteus medius and minimus insert together on the lateral aspect of the greater trochanter.

Answer 2077

ANSWER: B-COXA VALGA •Generally, the angle of inclination between the neck and shaft of the femur in older age decreases to around 120 degrees. •However, in pathologic conditions it can either increase or decrease from the predicted value. •When the angle of inclination increases, it is referred to as coxa valga. •Coxa vara on the other hand is a condition characterized by a decreased angle of inclination. •Genu varum and genu valgum are deformities characterized by a decreased Q-angle and increased Q-angle, respectively. •The Q-angle refers to the angle between the femur and tibia. •Hallux valgus is a condition that presents with a lateral deviation of the large toe.

Answer 2078

ANSWER: D-PLANTAR FASCIITIS •Plantar fasciitis is a common clinical condition that results from tearing or inflammation of the tough band of tissue stretching from the calcaneus to the ball of the foot (the plantar aponeurosis). •It usually happens to people who are on their feet frequently or engaged in athletics, especially running and jumping. •Plantar fasciitis is usually most painful in the morning, just after getting up from bed and beginning to walk. •Rest, orthotics, night splints, and antiinflammatory medications are employed in treatment. •A Pott’s fracture is a bimalleolar fracture, specifically a fracture of the distal end of the fibula (lateral malleolus) and medial malleolus, with outward displacement of the foot. •Dupuytren’s fracture involves fracture of the distal fibula with dislocation of the foot. Each of these fractures occurs due to sudden and forceful eversion of the foot.

Answer 2079

ANSWER: A-The tibia can be slightly displaced anteriorly When the anterior cruciate ligament is torn, the tibia can be slightly displaced anteriorly from the area of the knee joint by pulling firmly with both hands upon the leg, with the patient in a seated position. This is a positive anterior drawer sign.

Answer 2080

ANSWER: E. Deltoid •One important function of the deltoid ligament is the prevention of excessive extension of the ankle. •The ligament is so strong that excessive eversion can cause the medial malleolus to be pulled off (an avulsion fracture) rather than tearing the deltoid ligament.

Answer 2081

ANSWER: B. Acetabular branch of obturator •In infants and children up to about 8 years of age, the head of the femur gets its arterial supply by a direct branch of the obturator artery (variably, the medial circumflex femoral). •The arterial supply reaches the head of the femur at the fovea capitis by traveling along the ligament of the head of the femur. •Probably due to repeated torsion on the ligament, and therefore on the artery, this artery occludes early in life. •In turn, this source of supply is replaced by branches of the gluteal and femoral circumflex vessels.

Answer 2082

ANSWER: E.S1 •The ankle jerk reflex involves S1 and S2 levels. •L2 to L4 are involved in the patellar reflex. L5 is not a component of a deep tendon reflex.

Answer 2083

ANSWER: B. Tensor fasciae latae •The tensor fasciae latae assists in flexion of the thigh, as well as medial rotation and abduction. •Damage to this muscle would adversely affect these motions. •The rectus femoris extends the hip. •The vastus intermedius extends the knee. •The semimembranosus extends the hip and flexes and medially rotates the knee. •The sartorius assists in flexion and lateral rotation of the hip, as well as in medial rotation of the knee.

Answer 2084

ANSWER: B. Femoral triangle •The femoral triangle is the best place to palpate the femoral pulse. •It is bounded by the sartorius muscle laterally, adductor longus medially, and the inguinal ligament superiorly. •It contains the femoral vein, artery, and nerve (from medial to lateral, respectively). •The adductor canal lies deep between the anterior and medial compartments of the thigh and therefore cannot be palpated. •The popliteal fossa is the fossa at the back of the knee and contains the popliteal artery and vein, tibial nerve, and common fibular (peroneal) nerve. •The femoral pulse cannot be palpated here. •The inguinal canal is in the pelvis and is in communication with the anterior abdominal wall. •It contains the spermatic cord in males and round ligament of the uterus in females.

Answer 2085

ANSWER: A. Descending branch of the lateral circumflex femoral •If the femoral artery is occluded, the descending branch of the lateral circumflex femoral will provide collateral circulation to the thigh. •The descending genicular artery is a branch of the femoral and therefore would also be occluded. •The medial circumflex femoral artery is a proximal branch of the deep femoral artery and supplies part of the head of the femur. •The first perforating branch of the deep femoral artery supplies a small portion of the muscles of the posterior thigh. •Finally, the obturator artery supplies a very small artery and vascularizes only the most proximal part of the head of the femur and usually only during the early years of life.

Answer 2086

ANSWER: A. Femoral vein •In a femoral hernia, abdominal contents are forced through the femoral ring, which is just lateral to the lacunar ligament (of Gimbernat) and just medial to the femoral vein. •The femoral vein would be found immediately lateral to the femoral hernia. •This is correct in most cases because in the majority of people, the femoral vein is found more medial to both the femoral artery and nerve in the femoral triangle. •The adductor longus muscle as well as the pectineus muscle would be found deep and medial to the hernia.

Answer 2087

The correct answer is A. The femoral vein lies medial to the femoral artery. Key Reasoning: Anatomical Arrangement (NAVEL Mnemonic): The femoral triangle structures are ordered laterally to medially as Nerve, Artery, Vein, Empty space, and Lymphatics. This places the femoral vein medial to the femoral artery, making A the most accurate description. Analysis of Options: B (Femoral canal): Incorrect. The femoral canal is the medial compartment of the femoral sheath and contains lymphatics, not the vein. C (Lateral to femoral nerve): Incorrect. The femoral nerve is the most lateral structure; the vein lies medial to the artery and nerve. D (Lateral component of femoral sheath): Incorrect. The femoral vein resides in the intermediate compartment of the femoral sheath, while the lateral compartment contains the femoral artery. Clinical Relevance: Palpating the femoral artery pulse is the standard landmark for locating the femoral vein (medial to the artery), especially in procedures like cannulation. This is critical in patients with limited vascular access, as described in the scenario.

Answer 2088

The correct answer is A. The femoral vein lies medial to the femoral artery. Key Reasoning: Anatomical Arrangement (NAVEL Mnemonic): The femoral triangle structures are ordered laterally to medially as Nerve, Artery, Vein, Empty space, and Lymphatics. This places the femoral vein medial to the femoral artery, making A the most accurate description. Analysis of Options: B (Femoral canal): Incorrect. The femoral canal is the medial compartment of the femoral sheath and contains lymphatics, not the vein. C (Lateral to femoral nerve): Incorrect. The femoral nerve is the most lateral structure; the vein lies medial to the artery and nerve. D (Lateral component of femoral sheath): Incorrect. The femoral vein resides in the intermediate compartment of the femoral sheath, while the lateral compartment contains the femoral artery. Clinical Relevance: Palpating the femoral artery pulse is the standard landmark for locating the femoral vein (medial to the artery), especially in procedures like cannulation. This is critical in patients with limited vascular access, as described in the scenario.

Answer 2089

ANSWER: B. Vertical group of superficial inguinal •The superficial inguinal nodes are located near the saphenofemoral junction and drain the superior thigh region. •The vertical group receives lymph from the superficial thigh, and the horizontal group receives lymph from the gluteal regions and the anterolateral abdominal wall. •The deep inguinal lie deep to the fascia lata and receive lymph from deep lymph vessels (popliteal nodes). •The external and internal iliac nodes first receive lymph from pelvic and perineal structures

Answer 2090

ANSWER: D. Fibularis (peroneus) brevis •The fibularis (peroneal) brevis muscle originates from the lateral lower two thirds of the shaft of the fibula and inserts on the tubercle at the base of the fifth metatarsal. •Any injury to this area will affect this muscle. •Patients will present with a weakness in the eversion of the foot. •Fibularis (peroneus) longus, extensor hallucis longus and tibialis anterior all insert on the medial side of the foot and will not be affected in this patient. •The gastrocnemius inserts via the Achilles tendon to the posterior surface of the calcaneus.

Answer 2091

ANSWER: A. Obturator •The obturator nerve is a branch of the lumbar plexus that originates from L2 to L4. •It descends medial to the psoas on the posterior abdominal wall into the pelvis where it runs along the lateral wall of the lesser pelvis, above and anterior to the obturator vessels. •It enters into the medial thigh via the obturator canal (an opening above the obturator membrane) to supply the obturator externus muscle and the adductors of the thigh. •The femoral nerve innervates the anterior compartment of the thigh. •The inferior gluteal innervates the gluteus maximus muscle, while the superior gluteal innervates the gluteus minimus and medius. •The tibial nerve innervates the posterior compartment of the lower limb.

Answer 2092

ANSWER: A. Common fibular (peroneal) •The common fibular (peroneal) nerve is a branch of the sciatic nerve. •It descends on the lateral side of the popliteal fossa before winding around the head of the fibula. It then divides into superficial and deep nerves that supply the lateral and anterior compartments of the leg respectively. •Due to its superficial course, it is easily injured in patients with long leg casts (which run from just below the knee). •The nerve supplies the dorsiflexors of the leg, the skin of the first web space (via the deep fibular), the evertors of the foot, and the skin of the lateral side of the leg and dorsum of the foot (via the superficial fibular).

Answer 2093

ANSWER: C. Popliteal fossa •The lymphatic drainage of the foot follows its venous drainage. •The small saphenous vein drains the lateral side of the foot and the posterolateral leg. •It drains into the popliteal vein in the popliteal fossa. •Therefore a lesion on the lateral side of the foot will drain to the popliteal nodes in the popliteal fossa.

Answer 2094

ANSWER: E. Posterior cruciate ligament •The posterior cruciate ligament runs from the posterior aspect of the intercondylar area of the tibia to the medial wall of the intercondylar fossa. •It prevents posterior displacement of the tibia relative to the femur. •This is usually tested with the posterior drawer test, in which the physician pushes the tibia backward while the knee is flexed in an attempt to displace it posteriorly. •This is called the positive posterior drawer sign. •The anterior cruciate ligament prevents anterior displacement of the tibia on the femur. •The medial and lateral collateral ligaments stabilize the medial and lateral sides of the knee joint, respectively. •The medial meniscus is an intracapsular fibrocartilage that improves the articulation of the femur and tibia.

Answer 2095

ANSWER: B. Cutaneous branch of deep fibular (peroneal) •The deep fibular (peroneal) nerve is a branch of the common fibular (peroneal) nerve. •It is mainly a motor nerve that innervates the anterior compartment of the leg. Its only cutaneous innervation is to the skin of the first web space. •The saphenous nerve innervates the medial side of the leg and foot. •The cutaneous branch of superficial fibular (peroneal) nerve innervates the anterior part of the lower leg and the dorsum of the foot. •The sural nerve innervates the lateral side of the leg and foot.

Answer 2096

ANSWER: B. Sciatic The gluteal region can be divided into quad-rants by two lines positioned using palpable bony landmarks. One line runs inferiorly from the highest point of the iliac crest. The second line runs horizon-tally midway between the iliac crests and the ischial tuberosity. This divides the gluteal region into four quadrants. The sciatic nerve runs through the lower medial quadrant and must be avoided during intragluteal injections.

Answer 2097

ANSWER: A. Medial collateral ligament •A lateral blow to the knee often produces a trio of injuries referred to as the “unhappy triad.” •This involves damage to the anterior cruciate ligament, medial meniscus, and medial collateral ligament. •The medial meniscus and medial collateral ligament are often damaged together, as they are tightly attached to each other. •The lateral collateral ligament and lateral meniscus would not be damaged because a blow to the lateral knee would not put strain on these structures. •Damage to the posterior cruciate ligament would produce a positive “posterior drawer sign” and is typically damaged during a blow to the medial side of the knee. •The posterior cruciate ligament is stronger than the anterior and is only typically damaged when a person falls on the tibial tuberosity of a flexed knee. •Tendon of semitendinosus is on the medial side of the knee but is not attached closely to the other structures or taut in this injury type.

Answer 2098

ANSWER: A. Medial collateral ligament •A lateral blow to the knee often produces a trio of injuries referred to as the “unhappy triad.” •This involves damage to the anterior cruciate ligament, medial meniscus, and medial collateral ligament. •The medial meniscus and medial collateral ligament are often damaged together, as they are tightly attached to each other. •The lateral collateral ligament and lateral meniscus would not be damaged because a blow to the lateral knee would not put strain on these structures. •Damage to the posterior cruciate ligament would produce a positive “posterior drawer sign” and is typically damaged during a blow to the medial side of the knee. •The posterior cruciate ligament is stronger than the anterior and is only typically damaged when a person falls on the tibial tuberosity of a flexed knee. •Tendon of semitendinosus is on the medial side of the knee but is not attached closely to the other structures or taut in this injury type.

Answer 2099

ANSWER: D. Tibial •The saphenous nerve runs with the great saphenous nerve which was being removed from patient. •Sensory innervation to the areas of loss described is by the L4 root, which is carried by the saphenous nerve. •The obturator nerve innervates the skin on the superior medial thigh. Lateral femoral cutaneous innervates the lateral aspect of the thigh. •The tibial nerve supplies cutaneous innervation to the lateral aspect of the leg and if damaged would also produce muscular dysfunction. • The femoral nerve is a motor and sensory nerve and is the origin of the saphenous nerve.

Answer 2100

ANSWER: B. Calcaneofibular •Ligaments act to prevent excessive movement of joints. •When a joint is forced into a position, that ligament is stretched and will be tender or rupture if the force is severe enough. •Inversion is when the sole of the foot is turned medially and therefore will stretch ligaments that oppose this action. •The calcaneofibular ligament is on the lateral side and stretches between the fibula and the calcaneous. •It is the only ligament that would be damaged during such an action. •The calcaneonavicular and long and short plantar ligaments are located on the plantar surface of the foot and will not be damaged during inversion injuries. •The deltoid ligament is located medially and will not be affected.

Answer 2101

ANSWER: A. Quadriceps femoris •The patellar reflex causes extension of the knee and is produced by the quadriceps muscle group which consist of; biceps femoris and vastus lateralis, medialis and intermedius. •Quadratus femoris is a lateral rotator of the thigh. •The sartorius is a flexor of the hip and knee, and the pectineus is an adductor and flexor of the hip.

Answer 2102

ANSWER: B. Lateral femoral circumflex •The lateral femoral circumflex artery is a branch of the femoral artery close to the hip joint. •It gives a branch that runs down the lateral aspect of the thigh and joins the genicular anastomosis via the superior lateral genicular artery. •The medial circumflex femoral artery does not provide any branches that descend toward the knee. •The anterior and posterior tibial arteries are the terminal branches of the popliteal artery and would not receive any blood if the popliteal is damaged. •The fibular (peroneal) artery is a branch of the posterior tibial artery

Answer 2103

ANSWER: B. Obturator •The obturator nerve is responsible for innervation of the thigh adductors which form the medial compartment of the thigh. •The femoral nerve innervates the anterior compartment and is responsible for extension of the knee. •Common fibular (peroneal) nerve supplies the anterior and lateral compartments of the leg while the tibial nerve supplies the posterior compartments of the leg and thigh. •The common fibular (peroneal) and tibial nerves are branches of the sciatic nerve.

Answer 2104

ANSWER: A-Femoral nerve •The skin of the anterior medial thigh and medial leg and foot is supplied by the femoral nerve. •The saphenous nerve is a branch of the femoral and only supplies the medial leg and foot. •The obturator supplies the medial and medial posterior aspect of the thigh. •The tibial nerve supplies the skin of the posterolateral leg, lateral ankle and foot and sole of the foot. •The fibular (peroneal) nerve supplies the skin over the lateral aspect of the leg and dorsal aspect of the foot

Answer 2105

ANSWER: E-Tarsal tunnel syndrome •Tarsal tunnel syndrome is a compression neuropathy resulting from the compression of the tibial nerve in the tarsal tunnel. •The tarsal tunnel is located between the medial malleolus, the inferomedial surface of the calcaneus, and the flexor retinaculum. •The contents are the tibial nerve and its plantar branches, the tendons of the tibialis posterior, flexor digitorum longus, and the flexor hallucis longus muscles together with the posterior tibial vessels. •Any inflammation or swelling in the area will compress on these structures, most significantly the tibial nerve. •The posterior tibial vein will be most easily compressed but the nerve is most clinically significant. •Clinically, this syndrome is diagnosed with the patient’s history and physical examination findings including a positive Tinel’s sign (lightly tapping over the flexor retinaculum elicits numbness and tingling in the skin over the calcaneus and the sole of the foot).

Answer 2106

The most likely cause of this patient’s symptoms is inflammatory bowel disease (IBD). Explanation: • Diarrhoea and rectal bleeding are hallmark features of IBD. • Faecal incontinence at night suggests significant colonic inflammation, which is more characteristic of ulcerative colitis rather than Crohn’s disease. • The chronicity of symptoms (two weeks) also points towards an inflammatory etiology rather than acute infections like viral gastroenteritis. • Intersphincteric abscess would typically present with perianal pain, swelling, and fever, which are not described in this case. • Irritable bowel syndrome (IBS) does not typically cause rectal bleeding, making the options involving IBS less likely . Would you like more details on differentiating Crohn’s disease from ulcerative colitis?

MEGA EMRCS Flashcards

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