Mesenteric ischemia is an uncommon condition that is characterized by obstruction of one of the arteries to the intestines.
Blockage happens when a blood clot forms at a site which is already narrowed by atherosclerosis, when plaques gradually build up in the arterial walls, or when an embolus lodges in an artery.
Less often, mesenteric ischemia results from obstruction of a vein leading away from the intestine. Total obstruction of a mesenteric artery due to severe atherosclerosis may be preceded by a period of "abdominal angina"—abdominal pain that begins 20 to 30 minutes after eating and lasts for several hours. Blockage resulting from an embolus happens without warning.
Total blockage of a mesenteric artery causes death of the affected part of the intestine. Treatment involves extracting any permanently ruptured portion of the intestine and, if possible, extraction of the embolus or bypassing the portion of the artery which is obstructed by the clot.
What causes mesenteric ischemia?
Diagnosis of mesenteric ischemia
- Mesenteric thrombosis happens in people with far-advanced atherosclerosis (buildup of plaque and fatty matter on the blood vessel walls)
- Aneurysms (an abnormal enlargement or bulging) or blood clots in the vessels
- An embolus in the mesenteric arteries is most common in patients with atrial fibrillation, artificial heart valves, and valvular heart disease
- Oral contraceptives can increase the risk for occlusion of mesenteric veins
- Patient history and physical examination
- Abdominal x-ray
- For “abdominal angina,” a barium-swallow test or a CT scan may be followed by angiography.
- Magnetic Resonance Angiogram (MRA) scan can be done to produce the detailed three-dimensional images of your blood vessels from cross-sectional images of your body that are compiled.
- If complete blockage of a mesenteric artery is suspected, immediate angiography is done to locate the blockage, followed by emergency surgery if diagnosis is confirmed. When the diagnosis is strongly advised, surgery can be initiated without angiography.
Symptoms of mesenteric ischemia
- Change in eating habits due to post-meal pain or fear of eating
- Weight loss
- Abdominal swelling
- Nausea and vomiting
- Diarrhea or constipation
- Rectal bleeding or bloody stools
- Rapid heartbeat
Treatment of mesenteric ischemia
- When blockage of the mesenteric blood supply is only partial, surgical options include arterial bypass graft and percutaneous transluminal angioplasty.
- Complete occlusion requires immediate surgery. The ruptured part of the intestine is extracted and the left over ends are sewn together.
- A second operation is often needed 24 to 36 hours later to remove dead bowel tissue that was not apparent at the time of the first procedure.
- Heparin, an anticoagulant, may be administered after surgery to reduce the risk of subsequent clots.