Mesenteric ischaemia

Question 1

Acute mesenteric Ischaemia : Definition

Answer 1

Acute mesenteric ischaemia* is the sudden decreasein theblood supply to the bowel, resulting in bowel ischaemia and, if not promptly treated,death.

Question 2

Acute mesenteric Ischaemia : Causes

Answer 2

• Thrombus-in-situ (Acute Mesenteric Arterial Thrombosis, AMAT)
• Embolism (Acute Mesenteric Arterial Embolism, AMAE)
• Non-occlusive cause (Non-Occlusive Mesenteric Ischemia, NOMI)
• Venous occlusion and congestion (Mesenteric Venous Thrombosis, MVT)*

Question 3

Acute mesenteric Ischaemia : Clinical features

Answer 3

a generalised abdominal pain, out of proportion to the clinical findings,
diffuse and constant* pain, with associated *nausea and vomiting

Examination : non-specific tenderness

Question 4

Acute mesenteric Ischaemia : Investigations

Answer 4

Definitive : CT scan with IV contrast

Arterial bowel ischaemia will initially show on CT imaging as oedematous bowel, secondary to the ischaemia and vasodilatation,

Question 5

Acute mesenteric Ischaemia : Management

Answer 5

Acute mesenteric ischaemia is a surgical emergency, requiring urgent resuscitation

1. Broad spectrum antibiotics - due to risk of faecal contamination
2. Surgery :Excision and revascularisation of the bowel

Question 6

Chronic mesenteric ischaemia : Definition

Answer 6

1. Chronic mesenteric ischaemia (CMI) is caused by a reduced blood supplyto thebowel
2. Gradually deteriorates over time as a result ofatherosclerosis in the coeliac trunk, superior mesenteric artery (SMA), and/or inferior mesenteric artery (IMA).

Question 6

Chronic mesenteric ischaemia : Pathophysiology

Answer 6

1. Atherosclerotic plaque - builds up within mesenteric vessels and narrow lumen
2. Impaired blood flow - resulting in an inadequate blood supply to the bowel.
3. Collateral blood supply : atleast two of the coeliac artery; SMA and IMA must be affected for the patient to be symptomatic
4. Increased demand : during eating, exacerbates symptoms

Question 6

Chronic mesenteric ischaemia : Risk factors

Answer 6

The main risk factors for chronic mesenteric ischaemia are smoking, hypertension, diabetes mellitus, and hypercholesterolemia.

Question 6

Chronic mesenteric ischaemia : Clinical features

Answer 6

• Postprandial pain– classically occurring around 10mins-4hrs after eating*
• Weight loss– a combination of decreased calorie intake and malabsorption
• Concurrent vascular co-morbidities, e.g. previous MI, stroke, or PVD

Question 7

Chronic mesenteric ischaemia : Investigations

Answer 7

CT angiography is the diagnostic test of choice

Question 8

Chronic mesenteric ischaemia : Management

Answer 8

1. Conservative management : modify lifestyle risk factors
2. Surgical management
   * Endovascular or Open procedure