MET3 Revision: Colorectal Surgery I Flashcards
How would Meckel’s diverticulitis present? [5]
- most common: painless rectal bleeding
- age < 2 years
- passage of bright red blood per rectum (haematochezia)
- intractable constipation (obstipation)
- It is clinically indistinguishable from appendicitis: Right sided pain
Describe the pathophysiology of Meckel’s diverticulum
Meckel’s diverticulum is a small outpouching extending from the wall of the intestine and located in the lower portion of the small intestine.
Name 4 causes of bleeding that may cause acute abdominal pain [4]
Bleeding:
- AAA
- Ulcer
- Ectopic
- Trauma
Imaging used to investigate acute abdominal pain [3]
Plain radiographs (clinical effectiveness is queried)
- Erect chest XR: pneumonia
- Supine abdomen XR: small bowel obstruction
CT (investigation of choice)
Ultrasound
- Highly sensitive & first line for biliary pathology
- Good for gynaecological
- Bad for appendicitis
You suspect a patient has a biliary pathology, what is the first line of imaging used to diagnose this? [1]
Ultrasound
What is ascending cholangitis? [1]
What is it most commonly caused by? [1]
What is a classic triad of symptoms? [3]
Ascending cholangitis:
- is a bacterial infection of the biliary tree
- common predisposing factor is gallstones
- Charcots triad: RUQ; fever & jaundice
Describe the character of the pain described in a inflammation [1]
Constant dull pain: think appendicitis, diverticulitis
Describe the character of the pain described in peritonitis [1]
Constant sharp pain
Bowel sounds are helpful in suspected obstruction. Describe how this can be helpful [2]
High pitched (tinkling): obstruction
Absent: ileus (non-mechanical obstruction)
Describe a way of classifying bowel obstructions [3]
Name three suggestions for the each of the above [9]
Extramural: block bowel from outside
- Adhesions (congenital or aquired)
- Hernia
- Volvulus (caecal; sigmoid; small bowel)
- Compression from lymph nodes
Intramural: blockage from within the wall
- Tumours (adenocarcinoma, GISTs, lymphoma, leiomyosarcoma)
- Strictures bowel has narrowed due to: diverticular, ischaemic, IBD, post op,
- Intussusecption (wall of bowel moves into itself & blocks itself, most commonly at terminal ileum and caecum)
Intraluminal: within the wall
- Gall stones
- Bezoar
- Foreign body
- Meconium
What is the imaging that is the investigation of choice for bowel obstruction? [1]
State other imaging used [1]
CT: imaging of choice;
XR
What is gastrograffin AXR? [1]
When is its use indicated? [1]
Gastrograffin:
* Water soluble contrast for small bowel adhesive obstruction.
* If gastrograffin has passed into colon then suggests that will resolve (if not then surgery is indicated)
The “big three” causes account for around 90% of cases of bowel obstruction.
What are they? [3]
Where are they found (small or large bowel) [3]
Adhesions: small bowel
Hernias: small bowel
Malignancy: large bowel
Describe the pathophysiology of small bowel obstruction [5]
- Passage of food, fluids and gas, through the intestines becomes blocked
- Obstruction results in a build up of gas and faecal matter proximal to the obstruction
- This causes back-pressure: resulting in vomiting and dilatation of the intestines proximal to the obstruction.
- When there is an obstruction, and fluid cannot reach the colon, it cannot be reabsorbed: as a result, there is fluid loss from the intravascular space into the gastrointestinal tract leading to hypovolaemia & shock
- The higher up the intestine the obstruction, the greater the fluid losses as there is less bowel over which the fluid can be reabsorbed.
How does bowel obstruction lead to bowel ischaemia, infarction, necrosis, and perforation? [3]
- With time, bowel wall oedema forms
- This compresses the intestinal veins and lymphatics, reducing the venous drainage of the bowel
- As this occurs, it compresses intestinal arterioles and capillaries
- This prevents arterial perfusion to the bowel wall.
What’s a pneumonic for remembering the causes of small bowel obstruction?
“HANG IVs”
Hernias 2%
Adhesions (from previous surgery with formation of intra abdominal adhesions, commonly colorectal and gynaecological surgery)
Neoplasms (malignant, benign, primary or secondary) (5%)
Gallstone ileus
Intussusception
Volvulus
Strictures (eg Crohn’s disease (6%), ischaemia)
State 4 causes of intestinal adhesions that could contribute to the formation of bowel obstruction [4]
Abdominal or pelvic surgery (particularly open surgery)
Peritonitis
Abdominal or pelvic infections (e.g., pelvic inflammatory disease)
Endometriosis
Describe the difference in presentation of more proximal and more distal bowel obstructions [2]
In more proximal bowel obstructions:
- patients tend to present earlier
- abdominal pain and vomiting are the predominant symptoms.
In distal small bowel obstructions:
patients usually present after 2-3 days of abdominal pain.
- The predominant symptoms are abdominal distension and constipation.
Describe the relationship between abdominal pain and vomiting in SBO? [1]
- Abdominal pain often precedes vomiting (constant pain may indicate bowel ischaemia)
Describe the nature of vomit of SBO [1]
green bilious vomiting
Explain what VBG readings would you suspect with a patient with bowel obstruction? [2]
Metabolic alkalosis due to vomiting stomach acid
Describe the non-operative treatment for SBO [3]
Drip and Suck:
- Nil by mouth
- IV fluids to hydrate the patient and correct electrolyte imbalances
- NG tube with free drainage to allow stomach contents to freely drain and reduce the risk of vomiting and aspiration
What are the indications for surgery for SBO? [2]
Bowel compromise (e.g. ischaemia, perforation, necrosis), generally occurring in complete bowel obstructions
Surgically correctable causes (e.g. volvulus, incarcerated hernia, gallstone ileus, foreign body ingestion, tumour)
How would you surgically treat SBO? [4]
- Exploratory surgery in patients with an unclear underlying cause
- Adhesiolysis to treat adhesions
- Hernia repair
- Emergency resection of the obstructing tumour
- If surgery is being undertaken, patients should have antibiotic prophylaxis
What are 4 key emergency risks of SBO? [4]
Hypovolaemic shock due to fluid stuck in the bowel rather than the intravascular space (third-spacing)
Bowel ischaemia
Bowel perforation
Sepsis
If surgery is indicated for SBO, patients should be given antibiotic prophylaxis of which antibiotics? [3]
cefoxitin, or ampicillin plus gentamicin
What is A?
Anal abscess
Anal fissure
Haemorrhoid
Anal fistula
What is A?
Anal abscess
Anal fissure
Haemorrhoid
Anal fistula
An anal fissure is a superficial tear in the skin distal to the dentate line
What does this image depict?
Anal abscess
Anal fissure
Haemorrhoid
Anal fistula
What does this image depict?
Anal abscess
Anal fissure
Haemorrhoid
Anal fistula
What does the following best describe?
abnormal tunnel under the skin that connects the anal canal in the colon to the skin of the buttocks
Anal abscess
Anal fissure
Haemorrhoid
Anal fistula
What does the following best describe?
abnormal tunnel under the skin that connects the anal canal in the colon to the skin of the buttocks
Anal abscess
Anal fissure
Haemorrhoid
Anal fistula
Define what is meant by an anal fissure [1]
Anal fissure is a split in the skin of the distal anal canal characterised by pain on defecation and rectal bleeding.
They are longitudinal or elliptical tears of the squamous lining of the distal anal canal
What is a thrombosed haemorrhoid? [1]
How do you determine if an anal presentation is a thrombosed haemorrhoid? [3]
Thrombosed haemorrhoids occur when either an internal or external hemorrhoid fills with blood clots.
Thrombosed haemorrhoids are characterised by anorectal pain and a tender lump on the anal margin. It does not normally present with bleeding but this can occur if the haematoma spontaneously bursts.
Describe typical features of colorectal in colonscopy [2]
Shouldering
Mucosal obstruction
What is the name for the staging criteria of colorectal cancer? [1]
Describe each stage [4]
Duke’s classification
What does this colonoscopy of colorectal cancer depict?
Ulcerating
Stenosing
Polypoidal
Ulcerating
Stenosing
Polypoidal
What does this colonoscopy of colorectal cancer depict?
Ulcerating
Stenosing
Polypoidal
What does this colonoscopy of colorectal cancer depict?
Ulcerating
Stenosing
Polypoidal
What does this colonoscopy of colorectal cancer depict?
Ulcerating
Stenosing
Polypoidal
What does this colonoscopy of colorectal cancer depict?
Ulcerating
Stenosing
Polypoidal
Which of the following involves removing the sigmoid colon and upper rectum but sparing the lower rectum and anus?
Hartmann’s procedure
High anterior resection
Left hemicolectomy
Low anterior resection
Right hemicolectomy
Which of the following involves removing the sigmoid colon and upper rectum but sparing the lower rectum and anus?
Hartmann’s procedure
High anterior resection
Left hemicolectomy
Low anterior resection
Right hemicolectomy
