Ischaemic colitis and diverticulitis Flashcards
Outline the pathology of ischaemic colitis
Compromised perfusion to the marginal branches of the middle colic (SMA) and left colic (IMA) that supply the transverse and descending colon.
Which area of the colon is particularly susceptible to ischaemic colitis?
Splenic flexure
Name 3 predisposing factors for ischaemic colitis
Thrombosis of IMA AAA repair commonly ligates IMA Emboli Decreased CO or arrhythmias Shock Trauma Strangulated hernia or volvulus Drugs: OCP, cocaine, antihypertensives, psychotropic Abdominal surgery Vasculitis Coagulation disorders
Describe the presentation of ischaemic colitis
Sudden onset of abdominal pain, commonly in LIF
-typically occurs after eating
-pain out of proportion to clinical findings
Bright red PR bleeding
NaV
Diarrhoea
How should ischaemic colitis be investigated?
Urgent CT to exclude perforation
AXR would show thumb printing
Flexible sigmoidoscopy
Biopsy ➔ epithelial cell apoptosis and lamina propriety fibrosis
Later: Colonoscopy to exclude strictures and confirm mucosal healing
How is ischaemic colitis managed?
Many cases are resolved by correcting hypoperfusion
Symptomatic treatment
Surgery if fulminant ischaemic colitis + perforation/gangrene
Define diverticulum
Herniation of mucosa through thickened colonic muscle
Where are diverticula most commonly seen?
Sigmoid (85%) and descending colon
What lifestyle factor is diverticulum formation associated with?
Low-fibre diet - seen most in USA, Europe, and Australia
Name and describe the 3 conditions associated with diverticula
Diverticulosis (95%): Presence of asymptomatic diverticula
Diverticular disease: Symptomatic diverticula
Diverticulitis: Diverticular inflammation
What percentage of people aged 50+ have diverticula?
50%
Name 3 risk factors for diverticular disease
Aged 50+
Low fibre diet
Obesity
Complicated diverticular disease is commoner in patients who smoke, use NSAIDs, obese, low-fibre diets.
How does diverticulosis present?
Frequently an incidental finding on colonoscopy or barium enema.
How does diverticular disease present?
Large painless rectal bleed
Nonspecific abdominal complaints, usually left-sided:
-Intermittent lower abdominal/LIF pain
-Erratic bowel habit
Severe disease ➔ severe pain and constipation
Pain exacerbated by eating, diminished with defecation or flatus
NB. Isolated diverticular bleeds in absence of infection tend to spontaneously resolve ➔ active observation
How does diverticulitis present?
Severe lower abdominal pain Fever Malaise Change in bowel habit Rectal bleeding (occasional)
Name 4 complications of diverticulitis
Rectal bleeding (5-10%) Abscess Peritonitis Fistula Obstruction/stricture Perforation
N.B. 25% of acute diverticulitis is ‘complicated’
How should diverticular disease be investigated?
FBC ➔ inflammation in acute episodes
VBG ➔ lactate rule out mesenteric ischaemia
Colonoscopy: contraindicated in acute diverticulitis
Barium enema if uncomplicated
Erect CXR ➔ pneumoperitonium
AXR ➔ bowel obstruction, abscess
CT ➔ complicated diverticular disease
What is the management of diverticulosis?
Healthy high-fibre diet
Fluid intake
Outline the medical management of diverticular disease
Healthy high-fibre diet and fluids
Weight loss and smoking cessation
Laxatives
Analgesia
Outline the medical management of diverticulitis
Broad spectrum oral ABX
Analgesia
Clear liquids only ➔ gradual reintroduction of solid food
Check WCC and CRP for infection
What are the surgical indications for diverticulitis?
Acute complicated diverticulitis
Not improving with medical treatment
Outline the surgical treatment of diverticulitis
Sigmoid resection +/- colostomy
Percutaneous drainage of abscesses
Peritoneal lavage
What medication increases the risk of bleeding in diverticular disease
NSAIDs e.g. Diclofenac for arthritis pain
How should acute diverticulitis be followed-up?
Colonoscopy 2-6wk after resolution: confirms diagnosis, looks at complications such as strictures, and rules out other pathology such as colitis or carcinoma.
Advice to maintain high-fibre diet
Outline the Hinchey classification
Used to describe perforated acute diverticulitis
I. Pericolic or mesenteric abscess
II. Walled-off pelvic abscess
III. Generalised purulent peritonitis (5% mortality)
IV. Generalised faecal peritonitis (35% mortality)
May be used as a guide to the suitability for primary anastomosis following resection
