Intestinal ischemia results from occlusion of arterial inflow, venous outflow or failure of perfusion resulting in abdominal pain called abdominal angina.
CAUSES OF INTESTINAL ISCHEMIAIntestinal ischemia may result from any one of the following causes;
1. Arterial inflow occlusion
- Atheroma ( Read About: atherosclerosis, risk factors, Causes and Atheroma formation )
- Aortic disease
- Vasculitis e.g Takayasu’s arteritis
- Tumor (causing compression of vessel)
2. Venous outflow occlusion (Mesenteric vein occlusion)
- Hypercoaguable states e.g malignancy,
- protein C, protein S, or antithrombin III deficiency).
- Antiphospholipid antibody
- Intra- abdominal sepsis
- Portal hypertension and cirrhosis
3. Failure of perfusion
- Hypotension, shock
Acute small intestinal ischemia
- An embolus from heart in patient with atrial fibrillation is the commonest cause, usually occluding the superior mesenteric artery.
- Patient presents With sudden abdominal pain and vomiting. Abdomen is usually distended, tender and bowel sounds are absent. Patient is hypotensive and ill looking.
- Angiography may be performed in a stable patient and thrombolytic therapy (altepase) may be given for thrombotic disease,
- For unstable patient treatment is usually laparotomy with thromboembolectomy and resection of gangrenous bowel Antibiotics are given to all patients. Mortality is high.
Chronic small intestinal ischemia
- This is due to atheromatous occlusion or cholesterol emboli of the mesenteric artery, particularly in elderly.
- Patient presents with abdominal pain occurring after food. Acute mesenteric occlusion may develop on chronic occlusion.
- Diagnosis is made with angiography.
Mesenteric Vein occlusion
Diagnosis is made with contrast CT or angiography.
Treatment is long term anticoagulation. Surgery is reserved for bowel infarction.
- Occlusion of branches of superior or inferior mesenteric arteries often in older age group commonly presents with sudden onset of abdominal pain and passage of bright red blood per rectum with or without diarrhea. In majority of cases splenic flexure and left colon are affected. Underlying cardiovascular disease may be evident.
- On examination abdomen is distended and tender
- Abdominal x- ray often shows thumb printing at the site of splenic flexure.
- Medical symptomatic management is usually adequate; surgery may be required for perforation, gangrene or stricture formation.