- First described by Virchow in 1852
- Occurs as result of either superior mesenteric arterial or venous
occlusion
- Affects bowel from 2nd part of duodenum to transverse
colon
- 50% embolic arterial occlusion
- 25% atheromatous arterial occlusion
- 10% venous occlusion
- Whatever the underlining aetiology reduced capillary flow causes
intestinal necrosis
- Overall mortality is approximately 90%
Clinical features
- No single clinical feature provided conclusive evidence of the
diagnosis
- As a result the diagnosis is difficult and often delayed
- Early diagnosis requires a high index of suspicion
- Severe central abdominal pain is a common presentation
- Often is out of proportion to the apparent clinical signs
- Vomiting and rectal bleeding may also occur
- Features of chronic mesenteric ischaemia may also be present
- May also be evidence of an embolic source (e.g., recent MI, cardiac
arrhythmia)
- May also be other features of atherosclerotic disease
- 75% have ischaemic heart disease
- 25% have cerebrovascular disease
- 10% have peripheral vascular disease
Investigations
- No single investigation provides pathognomic evidence
- Serum white cell count is often raised
- Arterial blood gases may show a metabolic acidosis
- Serum amylase is raised in 50% of patients
- Abdominal x-ray may be normal early in the disease process
- Late features include dilated small bowel and 'thumb printing' due
to mucosal oedema
- Mesenteric angiography may confirm the diagnosis
Management
- Papaverine infusion into the SMA may be beneficial
- If fails to rapidly improve symptoms then laparotomy may be
indicated
- Laparotomy allows:
- Confirmation of diagnosis and assessment of extent of ischaemia
- Opportunity to revascularise SMA
- Resect necrotic small intestine
Picture provided by Asam Ishtiaq, Waterford Regional
Hospital, Ireland
- Revascularisation may be achieved by embolectomy, bypass or
endarterectomy
- Resection and primary anastomosis my be possible
- If doubt over bowel viability then a 'second-look' laparotomy may be
considered
- If extensive necrosis in elderly patient then palliative care may be
preferred option
Picture provided by John Cooper, Rotherham District
Hospital, Rotherham, United Kingdom
Bibliography
Mansour M A. Management of
acute mesenteric ischaemia. Arch Surg 1999;
134: 328-330.
McKinsey J F, Gewertz B L.
Acute mesenteric ischaemia.
Surg Clin North Am 1997;
77: 307-318.
Shetty S, Morris-Stiff G, Lewis M H. Intestinal ischaemia.
Hosp Med 2002; 63: 354-360. |