Acute Colorectal and Anoproctology Flashcards

Question

Describe the most well established "sphincter-preserving" procedures for fistula in ano, their original and subsequently analysed success rates, as well as their main advantages and disadvantages.

Answer 1

1. Ligation of the Inter-sphincteric Tract * Original series 94% * Meta-analyses 76% * Pros: * Down stages the fistula if it fails * Requires no special equipment * Cons: * Technically difficult for high fistulas with success rates from the OG of 60% 2. Endoanal advancement flap * Success proportional to thickness of flap * 70% for MAF, 81% for PAF, 92% for FAF * Pros: * High pressure zone repaired * Cons: * Is not actually sphincter preserving with PAF and FAF * Potential for mucosal ectropion

Answer 2

* **Anal fistula plug** * Simple but expensive * 54% * **Fibrin glue** * Success rate reportedly 0-87%! * **Video-assissted anal fistula treatment** * Requires fistuloscope and cautery * Reported success rate 82% but little take up * **Fistula laser closure** * Laser wire destroys the fistula tract epithelium and obliterates the remaining fistula tract through shrinkage * Success rates of 65% * **Over the scope clip** * Theorised to more securely close the internal opening * Success rates of 63% * **Stem cell treatment** * In evolution, improved cf placebo at 4 weeks but no difference at one year...

Answer 3

The lack of efficacy in long-term fistula healing when compared to other techniques might be tempered by a lack of detriment to continence, and the conclusion of the position paper by the Association of Coloproctologists of Great Britain and Ireland is that anal fistula plugs **may have a niche role in the patient who has some pre-existing incontinence**

Answer 4

Complications include: * Wound breakdown and bleeding ~13% * Failure ~30%; often converts to inter-sphincteric fistula Risk-factors for failure include: * Crohn’s disease * Horseshoe fistulas * Tracts longer than 3cm * Diabetes * Obesity

Answer 5

1. Omission of tract excision * Variable reported outcomes 2. Coring out the tract via the external opening * Small series seem to suggest improved rates of healing 3. Placing a Seton to drain the external component * Small series seem to suggest improved rates of healing 4. Addition of a trans-anal advancement flap * Results disappointing 5. Addition of an anal plug * Single study showed promise but success rates very high in both arms... 6. Insertion of a bio-prosthetic mesh between divided tract * "Biolift" small series, mixed results.

Answer 6

Catheter angiography = 0.5-1.0ml/min CTA = 0.3ml/min Radionucleotide Scintigraphy = 0.1ml/min

Answer 7

**Treitz’s muscle** maintains the anal cushions in their normal position. It consists of submucosal muscle, which **fixes the haemorrhoids to the internal anal sphincter.** These muscles will be encountered during haemorrhoidectomy and traverse the plane of dissection. **Park's ligament** is a mucosal suspensory ligament that penetrates the internal sphincter and fixes the sinusoids to the **conjoined longitudinal muscle.** This ligament is orientated longitudinally and is thought to be pathologically elongated in haemorrhoidal prolapse.

Answer 8

* Sliding of the anal cushions * Loss of the connective anal cushion tissue * Reduced venous return to the superior and middle rectal veins during defaecation * Dilated haemorrhoidal plexus with stagnant sinusoidal blood

Answer 9

80% success rate where success is defined as permanent relief of symptoms for follow-up period; marked improvement in symptomatology with rare manifestation of bleeding; symptom relief for a limited period of time. Complications: * bleeding (2.8%), secondary bleeding occurs between 5-15 days * thrombosed external haemorrhoids (1.5%) * bacteraemia (0.09%) * Mild bleeding, pain, slippage of bands, and difficulty urination are more common complications and normally minor

Answer 10

* Limited role given reported complication rate of ~30% * Theoretical advantage in anti-coagulated patients * Injection of 5% almond phenol into the submucosal space causes inflammation, apoptosis, and scarring. * Potential complications include * urological (prostatitis, haematuria, urinary retention, epididymitis) * bacteraemia * haemorrhage * mucosal necrosis * injection site ulcer

Answer 11

* Pain (opiate use in 40%) * Reduced pain with regional blockade * Reduced pain with oral metronidazole (unclear mechanism) * Multi-modality post operative regimen recommended * Urinary retention (15%) * Multifactorial * May be due to pudendal block * Assess risk pre-operatively * Bleeding (2%) * Primary or secondary * Infection (\<1%) * Higher rates in immunocompromised patients * Change in continence (\<1% incontinence) * Even without sphincter damage loss of cushions associated with reduced passive continence * Anal stenosis (\<5%) * Mitigated by leaving 1cm anodermal/mucosal bridges.

Answer 12

The rate of long-term faecal incontinence has been reported between 6 and 30%, with a meta-analysis of 22 studies with 4512 patients (prospective + retrospective) identifying that **14% had incontinence of some degree at greater than 2 years.** This is overwhelmingly flatus incontinence only (9/14%), with less than 1% having solid stool incontinence.

Answer 13

Botox inhibts contraction of **somatic striated muscle by inhibiting the release of Acetylcholine from pre-synaptic motor neurons.** But, in the treatment of fissure in ano, the injection is either into the IAS or into the inter-sphincteric space (IAS = smooth muscle), with proven efficacy; injecting Botox into the inter-sphincteric space is known to reduce both squeeze pressure and resting tone. Pharmacological studies on porcine IAS **concluded that Botox directly inhibits release of NA from sympathetic nerves, abolishing the normal sympathetic action of contracting the IAS.**

Answer 14

_Three clinical sub-types_ * **Passive incontinence**: involuntary leakage of faecal material or gas without awareness. * Loss of percetion, altered neurology, +/- sphincter injury * **Urge incontinence**: leakage of faecal material or gas in spite of active attempts to retain them. * Disruption of the sphincter or in compliance/capacity * **Faecal seepage**: undesired leakage of faecal material after normal bowel movement without abnormal continence or evacuation. * Incomplete evacuation and/or altered rectal sensation.

Answer 15

Faecal incontinence is generally defined as either ***the involuntary passage or inability to control the discharge of faecal material through the anus in individual older than the age of four.*** It is a common problem, and likely underreported in the general population due to embarrassment and the associated social stigma. It has an **estimated prevalence of 7.7%** (IQR 2.0 - 20.7%) in an adult population and is typically seen **more commonly with increasing age and in the female patient.**

Answer 16

**Anatomical** * Sphincter injury * Obstetric injury * Iatrogenic * Previous rectal surgery (LARS after ULAR) * Pelvic fractures **Neurological** * Pudendal neuropathy * Diabetes mellitus * MS * Spinal cord lesions * Central nervous ssytem disorders; CVA, dementia etc **Functional** * IBD * Faecal impaction with overflow * Diarrhoea * Radiation proctitis * Rectal prolapse * Fistula in ano * Hypersecretory rectal tumours.

Answer 17

The rectoanal inhibitory reflex (RAIR) (also known as the anal sampling mechanism, anal sampling reflex, rectosphincteric reflex, or anorectal sampling reflex) is a reflex characterized by a **transient involuntary relaxation of the internal anal sphincter in response to distention of the rectum.** This reflex is absent in Hirschsprungs disease, and may be absent in patients following low resection, or those with rectal prolapse.

Answer 18

* Resting and squeeze pressures along the length of the anal canal and sphincter complex (if using station pull-through technique) * Functional sphincter length can be calculated from this * RAIR using a 10ml puff of air via catheter-tip syringe * First sensation of fullness/flatus * Urge to defaecate * Maximum tolerance * Maximum squeeze pressure * Maximum duration of squeeze * Cough pressure.

Answer 19

The validity of PNTML remains unclear, as this test measures the conduction in the fastest remaining fibres and therefore significant nerve damage may be overlooked. A normal test does not exclude pudendal neuropathy. The test is also uncomfortable and in many cases the readings are unrecordable or not able to be reproduced. Most studies have shown a poor correlation between PNTML and clinical symptoms and treatment/surgical outcomes. **The routine use of PNTML in the assessment of patients with FI is therefore questionable.**

Answer 20

* Biofeedback is performed by inserting a pressure-sensitive EMG probe into the anal canal, and the pressure or muscle activity of the anal sphincter contracting around this device is measured with feedback of activity given audibly or visually. * Biofeedback works by **_“operant conditioning” to correct dyssynergia and improve coordination of the abdominal muscles and pelvic floor during defecation_**, and to improve perception of rectal filling in patients with impaired rectal sensation. * Success from biofeedback ranges from 38 – 100%. The exact mechanism for symptom improvement is unclear; **no consistent changes in sphincter pressures, rectal distension, or duration of contractions have been demonstrated.** * A recent systematic review of 13 randomised trials concluded that **twice the number of patients regained continence with biofeedback when compared to pelvic floor exercises**, and that a **_combination biofeedback and electrical stimulation was superior to any monotherapy._**

Answer 21

A DPG is measured in 3 stages: **rest**, **evacuation** and **recovery**. * In the resting phase, the anorectal angle is acute and the anal canal is closed. * Evacuation is characterized by an initiation of pelvic floor descent and widening of the anorectal angle. * Following evacuation, the anal canal closes and the anorectal angle becomes acute again. The pelvic floor and anorectal junction elevate to their resting position. DPG involves administering ~100mls of contrast via a rectal catheter, followed by thickened barium paste to simulate faeces. Rectal dimensions (length, diameter, anorectal angles, capacity, rectal wall morphology, perineal descent and evacuatory efficacy rate) are measured.

Answer 22

* Rationale: * Relatively cheap, low morbidity * Gold-standard for assessment of the sphincter complex * Indications: * Sphincter injury * Fistula in ano assessment * Incontinence * Influence on management: * Diagnosis of sphincter injury for operative planning * Path of fistulas and degree of sphincters traversed * Able to identify the presence of other anorectal pathology such as fistulae, tumours and abscesses * Limitations * User-dependant * Invasive * Anatomical information only

Answer 23

* Rationale * DPG is a dynamic fluoroscopic or MRI-based study of the function of defaecation * Proctography is **invaluable in distinguishing the three main pathophysiological causes for obstructed defecation** * Anismus * Rectocele * Intrarectal intussusception. * Indications * Incontinence * Obstructed defaecation * Prolapse, rectocele, intussusception * Pelvic floor disorders; dyssynergia * Influence on management * Diagnosis and exclusion of the above * Concurrent pathology identified pre-operatively * May lead to change in management e.g biofeedback for dyssynergia. * Limitations * Resource intensive (Barium porridge, spec. radiologist) * MRI-DPG costly and limited access * Invasive

Answer 24

* Rationale: * Physiological testing of the anorectal complex * Provides objective data * Indications: * Incontinence * Constipation * Anismus/pain - assuming pain controlled pre-procedure * IBS * Influence on management: * Lack of RAIR suggestive of Hirschsprung's * Sphincter function pre-fistula repair * Provides baseline function pre-intervention * Limitations: * Expensive and limited access * Invasive * Evidence base for interpretation guiding management is lacking.

Answer 25

A balloon expulsion test is a useful adjunct in the investigation of ODS or an evacuation disorder. A balloon expulsion test is performed by instilling a rectal balloon catheter with 50ml of warmed water. The patient is then asked to expel the balloon; a rise in intrarectal pressure of \<40mmHg indicates inadequate rectal pressure or impaired anal relaxation. Failure to expel the balloon after 5 attempts is suggestive of an outlet obstruction.

Answer 26

EMG records spontaneous and voluntary electrical muscle activity when needles are placed near or in the external anal sphincter (EAS) which allows mapping of myopathic or neuropathic processes. The EMG reading can be obtained from **surface or needle electrodes**, with the data from concentric needle electrodes the most robust. This technique is used to **identify sphincter injury as well as denervation–reinnervation potentials that can indicate neuropathy.**

Answer 27

1. **Basal phase** * Quiescent activity * Motility affected by gastro/duodenocolic reflexes * Non-propagating contractions * "Mixing movements" * Slowly mixes chyme from small bowel into faces * Propagating contractions * "Mass movements" * Antegrade propagation predominantly right sided * Retrograde propagation in the rectum to keep empty * HAPS 5-6 times per day; assoc. with flatus or urgency 2. **Pre-defaecatory phase** * Increase in HAPS which fill the rectum; RAIR detects solid motion and urge to defaecate forms 3. **Expulsive phase** * Voluntary straining increases IAP * Parasympathetic defaecation reflex triggered initiates further peristalsis and relaxes IAS * Somatic relaxation of the pelvic floor and puborectalis sling releases the angle and expulsion occurs 4. **Termination of defaecation** * The sense of complete rectal emptying, with involuntary contraction of EAS (closing reflex) and pelvic floor, closes the anal canal and reverses the pressure gradient towards the rectum. * The anal canal also elongates with distension of the vascular anal cushions to the basal state.

Answer 28

_OD is a symptom, not a diagnosis;_ Obstructed defecation (OD) refers to "***difficulty passing stool when there is a preserved urge to defecate."***

Answer 29

To be diagnosed with OD, patients must first meet the Rome IV criteria for **Functional Constipation**, and then the subset of criteria for **Functional Defecation Disorders.** This means that patients with OD are first identified as having "Functional Constipation" on historical/interview grounds, then they are classified as having a "Functional Defecation Disorder" on formal assessment with testing.

Answer 30

**Must include _2 or more_ of the following:** * Straining during \>25% of defecations * Lumpy or hard stools \>25% of defecations * Sensation of incomplete evacuation \>25% of defecations * Sensation of anorectal obstruction/blockage \>25% of defecations * Manual manoeuvres to facilitate \>25% of defecations * (eg digital evacuation, support of the pelvic floor) * **Fewer than 3 spontaneous bowel movements per week** **Loose stools are rarely present without the use of laxatives** **Insufficient criteria for irritable bowel syndrome** *\*\*Criteria fulfilled for the last 3 months with symptom onset at least 6 months prior to diagnosis.*

Answer 31

The patient must satisfy **diagnostic criteria for functional constipation** * During repeated attempts to defecate, there must be features of impaired evacuation as demonstrated by **2 of the following 3** tests: * Abnormal balloon expulsion test * Abnormal anorectal evacuation pattern with manometry or anal surface EMG * Impaired rectal evacuation by imaging *\*\*Criteria fulfilled for the last 3 months with symptom onset at least 6 months prior to diagnosis.*

Answer 32

The Oxford group divides OD causes into 3 pathophysiological groups: 1. **Functional OD** * eg Anismus/pelvic floor dyssynergia 2. **Mechanical OD** * eg High-grade rectal intussusception or external rectal prolapse 3. **Inefficient force vector** * eg Rectocele

Answer 33

* The **Cleveland Clinic Constipation Score** is widely adopted * Easy to administer with only 8 questions * The **Constipation Severity Index** is comprehensive but long * 78 variables, distinguishes between OD, STC, and IBS-C * The **Obstructed Defectation Score** is specific to ODS * Prospectively validated

Answer 34

* Position * Usually left lateral in Australasia * Sitting or knees-to-elbows higher yield * Inspection * Deformities, scars, descended perineum * Presence of coexisting haemorrhoids, tags, fissures, etc. * Anal gape * Have the patient bear-down and assess descent * DRE * Bulk, length, symmetry, tone of sphincter complex * Masses, mucosal abnormalities, rectocoele. * PR sling, repeated examination for relaxation of this * Proctoscopy * Assessment of mucosa * Prolapse or intussusception better detected on DPG.

Answer 35

1. **Constipation predominant irritable bowel syndrome (IBS)** * Constipation without prolonged colonic transit often associated with abdominal pain and bloating. 2. **Slow-transit constipation (STC)** * Associated with prolonged colonic transit time. 3. **Obstructed defecation**

Answer 36

* Biochemistry * Exclusion of organic causes * Anaemia, IDA are red-flags * Colonoscopy * Arranged if the mucosa requires exoneration (e.g IDA)\ * Examination under anaesthesia * May be valuable when clincal exam is limited * Colonic transit studies * Radio-opaque markers ingested * \<20% persistent at day-5 = normal * Persistent throughout colon = slow transit * Persistent in rectum = possible ODS * DPG * Visualization of anatomical and functional components of the pelvic floor and its associated dysfunction * Anorectal Manometry * Physiological data regarding anorectal sphincter function and rectal capacity and compliance. * Conduction studies * Objective data on regional nerve function.

Answer 37

* Lifestyle and behavioural modification * Physical activity reduces colonic transit time * Improved toileting habits * Fibre supplementation and judicious laxative use * Safe digitation may be a temporising measure * Pelvic floor rehabilitation * Biofeedback * Pelvic floor physiotherapy * Includes rectal irrigation * Operative * Botox has been used for "anismus" but relapse rates high * Aimed at correcting anatomical defects contributing to symptoms * Repair of rectocele * Repair of internal intussusception * Repair of rectal prolapse * Careful selection required given mismatch of anatomical defects, patient's subjective symptoms, and operative approaches available.

Answer 38

Recto-rectal Intussusception * Grade I * Descends no lower than proximal limit of the rectocele * Grade II * Descends into the level of the rectocele, not to the sphincter Recto-anal intussusception * Grade III * Descends onto sphincter / anal canal * Grade IV * Descends into sphincter / anal canal * Grade V * External rectal prolapse ***In general, repair of external rectal prolapse is not controversial. However, repair of IRP has generated controversy both within the surgical literature and tabloid media. Surgery for IRP with isolated OD remains controversial. _Most surgeons would advocate an extensive trial of conservative measures and biofeedback for OD with IRP._***

Answer 39

Rectoceles frequently present as part of the pelvic floor pathology and it is unusual to find them in isolation. However, they also occur asymptomatically with rectocoeles of \<2cm present in up to 80% of asymptomatic female volunteers. If anismus or pelvic dyssynergia is present, this should be addressed first with lifestyle and behavioural modification as well as pelvic floor physiotherapy and biofeedback. Generally, if prolapse is also present (co-exist in ~80%) then the prolapse takes priority, and some approaches (e.g. LVMR) may address both pathologies. In those in whom surgery is in-fact indicated; anterior Delorme's. *Outcomes from surgery may still be improved be improved by further case selection:* ***• Patients who digitate on most defecations AND • Rectoceles that do not empty on proctography***

Answer 40

* 1^st degree * Laceration of the vaginal mucosa or perineal skin only * 2^nd degree * Involvement of the perineal muscles * 3^rd degree * a) \<50% of EAS is torn * b) \>50% of EAS is torn * c) EAS and IAS are torn * 4^th degree * Laceration/tear of the perineum involving the entire anal sphincter complex and the anorectal epithelium.

Answer 41

Obstetric anal sphincter injury complicates ~11% of births * **Maternal** * Primiparity * Asian/Indian ethnicity * Age \<20 years * Shortened perineum (\<20mm) * **Fetal** * _Large birth weight (\>4kg)_ * Shoulder dystocia * Occipito-posterior position * **Delivery** * _Instrumental (forceps, vaccum assisted)_ * Prolonged second stage labour (\>60min) * Gestational age \>41 weeks * Epidural use * Oxycontin use * _Episiotomy_ * Innapropriate maternal position (lithotomy and squatting)

Answer 42

* While a first or second-degree tear can be repaired in the birthing suite, an **_OASI should be repaired in an operating theatre_** under spinal or general anaesthesia, with appropriate lighting, availability of equipment and aseptic operating conditions. * If surgical expertise is not available, then **delay by 8-12 hours is acceptable** based on a Swedish RCT showing that this delay is not associated with worse outcomes at one year.

Answer 43

* The two recognised methods of repair are end-to-end and overlap. * 2^nd, 3^rd_A, and 3^rd_B degree tears should be repaired end-to-end * A recent Cochrane systematic review of six trials reported that primary overlap repair was associated with significantly lower rates of faecal urgency and anal incontinence at 12 months. * However, at 36 months follow up, there was no difference in quality of life, flatus incontinence or faecal incontinence between the two techniques. * There is no consensus on which OASI patients require defunctioning * No routine use * Most surgeons would support the use of a stoma in someone with a **4^th degree injury extending above the levator**, or where **significant risk of fistula exists.**

Answer 44

* Analgesia * Regular ice packs or frozen nappies for cold-compress * Antibiotic * Antibiotics administered at time of repair can help reduce wound infections from OASI, especially as approximately 25% of women suffer a wound breakdown after OASI repair. * Wound sepsis is a significant post-partum problem * Pelvic floor training * Shown in a Norwegian RCT to reduce post partum anal incontinence symptoms in women who underwent primary repair of an OASI * Avoidance of constipation * Bulking fibre laxatives * Counselling * Significant psychosocial issues arise from OASI

Answer 45

* \*\*Consider re-referring to obstetric team for a de-brief * Significant mental anguish around traumatic delivery * Can be helped by de-briefing with specialists * Complete history and exam with particular attention to risk factors such as large birth weight, instrumental delivery, and episiotomy. * Complete exam * Validated incontinence scores e.g. Wexner * Endo-anal USS * Anorectal manometry * Pudendal nerve testing for neuropathy

Answer 46

* Perineal massage during labour * Cochrane review showing that a warm compress between contractions reduces 3^rd and 4^th degree tears * Caecarean delivery * Considered in those with pre-existing OASI or known large birth weights and other risk factors (Asian/Indian ethnicity) * Maternal birth position * Avoid prolonged lithotomy or squatting * Kneeling and on-all-fours thought to be protective.

Answer 47

Systematic reviews have shown: * Mean reduction in FI episodes per week of 7-8 * Reduction in Wexner score of 8-9 * Median trial phase success rate was 81% * **Full continence achieved in 43%** in those who went on to a permanent implant. ***For such an expensive and invasive therapy, there is yet to be a randomized controlled trial comparing SNS and sham and the mechanism of action of SNS has yet to be fully explained.***

Answer 48

* Faecal incontinence where organic causes have been excluded * Low anterior resection syndrome (LARS) patients * Patients with congenital faecal incontinence * Patients with an anal sphincter defect * *\*Small RCT showing benefit in IBS* * *\*\*Low level trials showing benefit in IPAA and Radiation FI* *In fact, in patients with a sphincter defect, the paradigm has shifted to using SNS as the primary intervention instead of an anal sphincter repair.*

Answer 49

* Failure of SNS efficacy * ~40% achieve complete continence * Pain or dysthesia * Complaints to FDA suggest about 30% * Re-operation * ~20% reoperation rate * ~10% removal rate A recent study in New Zealand found that SNS cost \>NZ$30,000 for implantation and \>NZ$46,000 if reintervention was required and in their study, reintervention was required in 41.5%.

Answer 50

* "Traditional alternatives" * Dietary and behavioural change * Pelvic floor physiotherapy and biofeedback * Anal sphincter repair * "Experimental or novel alternatives" * Bulking agents (i.e. injectable polymers into sphincter) * Gatekeeper® * SphinKeeper© * Magnetic sphincters * Secca-system - RFA scarring to induce sphincter contraction

Answer 51

Use of the ‘H’ technique can accurately identify the S3 foramen, therefore increasing the chances for a successful outcome of SNS therapy. This is done by marking the **medial edges of the sacral foramina under fluoroscopic guidance**, and **horizontally marking at the lowermost point of the sacroiliac joint**. The meeting points of the ‘H’ are the landmark for S3.

Answer 52

* SNM entails surgical placement of stimulating electrodes adjacent to the sacral nerve root, typically S3. * Despite its clinical success, the mechanism of action has not been clearly elucidated. * Sacral neuromodulation has been **hypothesised to modulate afferent, central, autonomic, and somatic neural pathways** * It may act through somatic afferents to reduce inhibition of sphincter function via ascending central pathways. * Locally, external sphincter hypertrophy secondary to stimulation have also been implicated * **There is little evidence that SNM affects sphincter activation, anal squeeze pressures, anal reflexes, or internal sphincter slow wave amplitudes**

Answer 53

* The Stapled Trans-Anal Rectal Resection procedure has had cyclical popularity, and may have a **renewed role is established pelvic floor MDT services.** * In **_selected patients_** it may offer acceptable resolution rates ~70% * Patients should have an intact rectum (Endo-USS + Manometry) * Exclusion criteria * Enterocoele * Solitary Rectal Ulcer * Significant gynaecological pathology * Foreign bodies in the pelvis * Incontinence

Answer 54

The contemporary belief is that of local trauma with the passage of hair into the subcutaneous tissues of the natal cleft. Karydakis proposed that hair, with its chisel-like roots, inserts into the natal cleft, leading to a foreign body tissue reaction and subsequent infection. Bascom reported that the vacuum effect of the movement of muscles within the gluteal region allows hair to enter through pre-formed pits within the natal cleft. Although the specific mechanisms whereby pilonidal disease and the development of sinuses form are unclear, and professional opinions are conflicting, a **chronic inflammatory process secondary to the presence of hair within the natal cleft is an established contributing factor.**

Answer 55

* Hirsutism * Obesity (BMI \>24) * Sedentary work (seated for \> 6 hours per day) * Male gender * Poor sacrococcygeal hygeine * Deep natal cleft * Excessive sweating A person who is **hirsute**, with a **sedentary occupation**, who **bathes less than twice a week** is **_291 times more likely to develop PNA_** than a person without thosew risk factors.

Answer 56

1. Acute pilonidal abscess 2. Sub-acute recurrent pilonidal abscess 3. Chronic pilonidal disease 4. Complicated pilonidal disease

Answer 57

* Due to the morbidity of surgery, it should only be considered in the symptomatic patient or those with chronic disease. * Removal of diseased tissue, including hair and granulation tissue, with minimisation of healthy tissue excised. * Off midline wound * Natal cleft flattening

Answer 58

* Acute PNA * Perianal fistula or abscess * Acute hydradenitits-suppurativa * Infected sebaceous cyst * Recurrent pilonidal cysts or pits * Sacrococcygeal sinus (vestigial remnant medullary canal) * Presacral sinus or dimple (traction dermoid) * Inclusion dermoid cyst * Complex pilonidal disease * SCC or BCC * Atypical infections; actinomycoses, TB, syphilis * Chronic hydradenitis suppurativa * Pyoderma gangrenosum * Sacral osteomyelitis

Answer 59

In acute disease; drain the pus off the midline and curette the cavity. For chronic disease: * **Non-operative measures** * Improve sacrococcygeal hygeine - known RF * Depilation - recommended by ASCRS guidelines * **Non-excisional, non-operative interventions** * Phenol injection * 80% phenol solution into tract for several minutes * Associated with cellulitis and dermal injury * Limited evidence, poor outcomes in sepsis * Fibrin glue * Very limited evidence * Antibiotics * Often used in primary care for abscesses * No established role for chronic / complex disease * **Non-excisional, operative interventions** * Pit-picking / Gip's procedure * Comparable outcomes with excisional operations * Ambulatory surgery under local * LOCULA procedure * Similarly promising outcomes * Video-assisted ablation * Small series, resource intensive, no better cf Gip's * **Excisional operations** * Karydakis * Down to sacro-coccygeal fascia * Low recurrence 1% reported by Karydakis * Bascombe * "Smear" flap w/o fat excision * Low recurrence rates 4% reported by Bascombe * Rhomoid / Limberg flap * V-Y advancement flap / Z-plasty flap

Answer 60

Altered autonomic regulation of the large intestine is the most commonly suggested mechanism for ACPO. An **increase in sympathetic modulation** leads to **decrease in colonic motility and dilatation**, especially in the proximal colon. **A decrease in sacral parasympathetic** modulation leads to relative **atonicity of the distal colon** causing functional obstruction at the level of splenic flexure. The role of the autonomic nervous system is supported by the use of neostigmine in the treatment of ACPO.

Answer 61

**Neostigmine is a parasympathomimetic** that works by reversibly inhibiting cholinesterase; it increases the activation of muscarinic receptors by inhibiting the breakdown of acetylcholine. In pseudo-obstruction, this is though to stimulate colonic motor activity and decrease intestinal transit time via enhancement of the parasympathetic activity in the gut. Given IV as a 2mg bolus. Neostigmine has pro-cholinergic effects, so can cause **bradycardia/bradyarrhythmias**. Cardaic monitoring should be considered. A recent **Australian retrospective study showed treatment success with subcutaneous administration of neostigmine (0.5mg upto four times daily) in 93% of patients.** This study showed no incidences of bradycardia with subcutaneous neostigmine.

Answer 62

* Younger age * Electrolyte abnormalities * Being on anti-motility agents * Opiate usage * Post-operative setting

Answer 63

Acute colonic pseudo-obstruction is a **clinical disorder** characterised by **severe colonic distension** in the **absence of mechanical obstruction**.

Answer 64

* Surgical (head to toe) * Neurosurgery * Spinal asurgery * Thoracic surgery * Cardiac surgery * Solid organ transplant * Pelvic surgery / Pelvic trauma * C-section / Vaginal delivery * Long bone / hip surgery * Medical (head to toe) * Neurological d/o; CVA, dementia, severe CI * Cardiac; MI, CHF, Cardiogenic shock * Infectious; Varicella zoster, CMV * Haematological malignancies * Medications; neuroleptics, immuno-suppressive meds

Answer 65

Paralytic ileus refers to **abnormal pattern of gastrointestinal motility** following an abdominal operation, that leads to **obstipation and intolerance in oral intake.** * Post-operative ileus * Resolution within 4 days * 10-30% * Prolonged post-operative ileus * Persistence beyond 4 days * 10% * Recurrent ileus * Recurrs after resolution

Answer 66

The pathophysiology of POI is a complex interplay between the neurogenic, humoral and pharmacological components. * **Initial sympathetic phase** * Mediated by adrenergic activity inhibiting perstalsis * **Subsequent inflammatory phase** * Pro-inflammatory cytokines increase NO and PG within the gut wall inhibiting peristalsis.

Answer 67

1. Direct penetrating injury * Firearms and knives * Colon second only to small bowel in visceral injury rates * Direct local injury to the organ with mechanical loss of barrier and resultant peritonitis * GSW usually require segemental resection * Stab wounds can often be repaired primarily 2. Pneumatic blow-out of the colonic or rectal wall * 0.5% of all blunt trauma injuries * 10% of blunt trauma injuries taken to theatre * Mostly MVAs * Often large segement of colonic wall ruptured neccesitating segmental resection 3. Mesenteric/vascular injury affecting associated colon / rectum * Associated with deceleration injuries * May present later when devitalised colon perforates * Associated with ischaemia/reperfusion injury * Significant inflammatory mediators

Answer 68

* Destructive * Wound \>50% circumference of colon * Complete transection * Significant tissue loss * Devascularised segment * Non-destructive * Wound \<50% circumference of colon * No devascularisation In blunt trauma: * Destructive * Serosal tear \>50% of circumference * Full thickness perforation from blunt injury * Mesenteric devascularisation

Answer 69

* Primary peritonitis * Occurs most commonly in setting of acsites * CAPD and cirrhosis * Monomicrobial e.g. *Enterobacteriaceae, Streptococcus* * Rarely requires surgical intervention * Secondary peritonitis * Occurs most commonly due to disruption of GI tract * Polymicrobial e.g *Bacteroides* and *E. coli* * Underlying cause requires surgical intervention * Tertiary peritonitis * Recurrent or progessive infection after source control of secondary peritonitis * Usually in immunocompromised or critically ill * Often MDR-organisms e.g. ESBL, Fungi, VRE

Answer 70

Sepsis is a ***“life threatening organ dysfunction caused by a dysregulated host response to infection”***. Septic shock is a subset of sepsis and is present when there are profound circulatory, cellular, and metabolic abnormalities resulting in **inadequate tissue oxygenation and perfusion.** Septic shock may be clinically determined by: * Vasopressor requirement to maintain MAP of 65mmHg or greater * Serum lactate \>2mmol/L * Above in absence of hypovolaemia

Answer 71

The SOFA and q(uick)SOFA scores are used to identify septic patients likely to require ICU support. Bedside qSOFA: * SBP \<100mmHg * RR \>22 * GCS \<15 The SOFA score uses seven measures of organ dysfunction * Platelet count, bilirubin, mean arterial pressure, GCS, serum creatinine and urine output per day. * Each measure is assigned a maximum score of 4, with higher scores indicating increased mortality. Organ dysfunction is **potentially life threatening if the Sequential Organ Failure Assessment score (SOFA) increases by two points or greater, or the bedside qSOFA score is two or more**.

Answer 72

Intra-abdominal hypertension (IAH) is a ***“sustained or repeated pathological elevation in intra-abdominal pressure greater than or equal to 12mmHg”.*** IAP is typically **_2-7mmHg in healthy individuals_** and 5-7mmHg in those who are critically unwell. Abdominal compartment syndrome (ACS) is defined as a "***sustained IAP greater than 20mmHg with associated new organ dysfunction".***

Answer 73

**_Primary ACS_** * Primary ACS results from injury or pathology within the abdomen or pelvis eg. Pancreatitis, ascites, haemoperitoneum. This usually requires early intervention which may be in the form of surgery or interventional radiology. **_Secondary ACS_** * Secondary ACS results from pathology outside the abdomen or pelvis eg. Burns, sepsis, overzealous fluid resuscitation **_Recurrent ACS_** * Recurrent ACS occurs when ACS re-develops after treatment of either primary or secondary ACS.

Answer 74

Non-operative measures: 1. Evacuate intraluminal contents * Cathartic laxatives, NG tubes, IDC, rectal tube * Endoscopic decompression 2. Evacuate intra-abdominal space occupying lesions * Drain collections, drain ascites, remove packs 3. Improve abdominal wall compliance * Muscular paralysis or relaxation 4. Optimise fluid administration * Diuresis * Goal directed fluid therapy * Consider haemodialysis 5. Optimise regional and systemic perfusion * Judicious vasopressors Operative measures: 1. Midline laparotomy with temporising VAC laparostomy

Answer 75

The most well known is the **Alvarado** score, which incorporates clinical, symptomatic, and laboratory indices into its calculation of **low/medium/high risk**. The **APPEND** (Anorexia, migratory Pain, Peritonism, Elevated CRP, Neutrophilia, and Dude) score is locally validated; a score of 1 has a **NPV of 95.6%** and as score of **5 has a PPV of 95.5%**.

Answer 76

Recently assessed in a 2019 meta-analysis in Annals of Surgery: * Surgery has a higher total success rate * Treatment failure rate of 30% with antibiotics * This is sustained at one year * Equivalent length of stay * Lower cost with antibiotic treamtent * No increase in perforation rate in those treated with antibiotics

Answer 77

Interval appendicectomy is recommended for patients managed non-operatively for complicated appendicitis, because this cohort has been found (on meta-analysis) to have **higher rates of neoplastic pathology** upon resection. The overall rate of neoplasm is about **10-20%** and is much higher in patients **over 30 years of age**. The most common neoplasm is a mucinous neoplasm. There is no evidence for interval appendicectomy in patients with non-operatively managed *uncomplicated* appendicitis.

Answer 78

1. **Mucinous** * Simple mucocoeles * Appendiceal mucinous neoplasms * Low grade appendiceal mucinous neoplasms * High grade appendiceal mucinous neoplasms * Appendiceal mucinous adenocarcinomas 2. **Non-mucinous** * Epithelial tumours * Non-mucinious adenocarcinomas * Goblet cell adenocarcinomas * Neuroendocrine tumours

Answer 79

* **A simple mucocoele has no cellular dysplasia** and is simply the result of obstructive build up of mucin within the appendiceal lumen. * **LAMNs and HAMNs have some degree of cellular atypia**, the grade of this (based on mitotic activty and nuclear atypica) is what distinguishes from one another. * **The defining feature of adenocarcinomas** of the appendix is their **infiltrative invasion pattern**, typically with a marked desmoplastic stromal reaction. * Although **by definition LAMNs and HAMNs do not invade**, their expansile growth may push and **thin the appendiceal wall** until the appendix ruptures, and the resultant spillage of cellular or acellular mucin may lead to pseudomyxoma peritonei (PMP).

Answer 80

* There is lack of data regarding appropriate intervals for imaging surveillance in these patients. * In patients with completely resected LAMN/HAMN, one strategy is to obtain **MRI (more sensitivity for detecting extracellular mucin**) or CT **_every 6 months for 2 years._** * Following that, HAMN should have annnual follow up with MRI/CT. * Tumour markers CEA, CA 19.9 and CA 125 should also be obtained at baseline and for surveillance. * Follow‐up colonoscopy is also recommended with an **increased incidence of synchronous colorectal lesions** seen * 42% in one study

Answer 81

* **NETs \>2cm** should undergo right hemicolectomy due to risk of lymph node metastases. * NETs between **1‐2cm have an intermediate risk**; right hemicolectomy is indicated if the following are present: * **mesoappendiceal invasion \>3mm** * **mitotic index \>2** * **Ki 67 \>3%** * **LVI** * **involved margins**

Answer 82

* Age * Gender * Previous lower GI bleed * DRE findings * Heart rate * Blood pressure * Haemoglobin Different weighting to each component, with the heaviest on Hb. **Safe discharge if score is 8 or less.**

Answer 83

All patients diagnosed with uncomplicated ACPO and without biochemical and radiological signs of ischemia, perforation or peritonism, can be treated supportively. Medical intervention: * Neostigmine * 0.5 mg submit QID * 2mg IVI (requires cardiac monitoring) Endoscopic intervention: * Colonoscopic decompression in ACPO can be technically challenging and it is recommended that it should be undertaken by an experienced endoscopist. The perforation rate is quoted to be between 1-3%.

Answer 84

Pilonidal Disease = H x F x V² H = Hair, local or distant F = Force, applied by hair (root down) V = Vulnerability, predisposing pores, splits, erosions at the natal cleft. Bascombe's theory of negative pressure "drawing-in" the hair may modify the F component.

Acute Colorectal and Anoproctology Flashcards

(111 cards)