Intestinal ischaemia

Question 1

Define intestinal ischaemia and name the three different types:

Answer 1

Obstruction of the meseneteric arteries leading to ischaemia and necrosis.

Acute mesenteric

Chronic mesenteric a.k.a intestinal angina

Chronic colonic ischaemia - ischaemic colitis

Question 2

What is the aetiology of acute mesenteric ischaemia:

Answer 2

affects the superior mesenteric artery.

Involves the small bowel

Arterial thrombosis (35%) and embolism (35%)

non-occlusive causes:low flow rate and low CO

Venous thrombosis (5%) - in young people with hypercoagulable states

Other causes: vasculitis, radio-therapy and strangulation.

Question 3

Aetiology of chronic mesenteric ischaemia:

Answer 3

Low flow state with atheroma.

Common history of vascular disease.

Question 4

Aetiology of ischaemic colitis:

Answer 4

inflammation caused by occlusion of the inferior mesenteric artery.

Ischaemia leads to inflammation, oedema, necrosis and ulceration.

Commonly affects: splenic flexure and watershed areas (to a region that receives a dual blood supply from the most distal branches of two large arteries) of the inferior and superior mesenteric artery.

Caused by:

• thrombus or embolism occlusion
• iatrogenic ligation
• hypovolemia
• small vessel vasculitis - in young people mainly
• vasospasm (cocaine)
• Hypercoagulable states

Question 5

Risk factors of intestinal ischaemia:

Answer 5

AF

Endocarditis

Arterial thrombosis (hypercholesteriemia, hypertension, smoking, DM)

Venous thrombosis (portal hypertension, splenectomy, septic thrombophlebitis, OCP, thrombophilia)

Question 6

Epidemiology:

Answer 6

UNCOMMON

more common in the elderly

Question 7

Symptoms of acute mesenteric ischaemia:

Answer 7

Severe abdo pain

No abdo signs

rapid hypovolemia - shock

Question 8

Signs of chronic mesenteric ischaemia:

Answer 8

severe colicky abdo pain

post-prandial pain

weight loss

upper abdo bruits

PR bleeding

Question 9

Symptoms of ischaemic colitis:

Answer 9

LLQ pain

Bloody diarrhoea

Question 10

What are general symptoms of intestinal ischaemia:

Answer 10

Fever

vomiting

nausea

Bloody diarrhoea

history of heart disease

weight loss

Question 11

signs of intestinal ischaemia:

Answer 11

fever + tachycardia

diffuse abdo tenderness

abdo distension

Bowel sounds may be absent

upper abdo bruits

dis-appropriate degree of CVS collapse

Question 12

Investigations of intestinal ischaemia:

Answer 12

often done with clinical diagnosis or post laparotomy

AXR - early sign is thickening of small bowel folds

Bloods - FBC (decreased HB and increased WCC), ABG (lactic acidosis), U + E’s, LFT’s, clotting, cross macth

mesenteric angiography (only if stable)

CT/MR angiography

Question 13

What is the gold standard for ischaemic colitis:

Answer 13

Colonoscopy with biopsy.

Barium enema will show thumb printing of submucosal swelling.