Mesenteric ischemia is an uncommon condition characterized by obstruction of one of the arteries to the intestines. Blockage occurs when a blood clot forms at a site already narrowed by atherosclerosis (mesenteric thrombosis), when plaques gradually build up in the arterial walls, or when an embolus (a blood clot from a distant site) lodges in an artery. Less often, mesenteric ischemia results from blockage 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. Obstruction resulting from an embolus occurs without warning.
Complete blockage of a mesenteric artery causes death of the affected portion of the intestine. Treatment involves removing any permanently damaged portion of the intestine and, if possible, removal of the embolus or bypassing the portion of the artery obstructed by the clot.
What Causes Mesenteric Ischemia?
- Mesenteric thrombosis occurs 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 may increase the risk for occlusion of mesenteric veins.
Symptoms of Mesenteric Ischemia
- Abdominal angina: intermittent dull or cramping pain beginning 20 to 30 minutes after a meal and lasting several hours.
- Severe, cramping abdominal pain, usually beginning around the navel. Pain later becomes steady throughout the abdomen.
- 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
Prevention of Mesenteric Ischemia
As much as possible, observe heart-healthy behaviors, such as maintaining a healthy diet, engaging in regular aerobic exercise and avoiding cigarettes.
Diagnosis of Mesenteric Ischemia
- Patient history and physical examination
- Abdominal x-ray
- For “abdominal angina,” a barium-swallow test (use of barium to help create a clear image of the intestines on an x-ray) or a CT (computed tomography) scan may be followed by angiography (x-ray of the blood vessels after injection of a contrast agent).
- Magnetic Resonance Angiogram (MRA) scan also produces 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 suspected, surgery may be initiated without angiography.
How to Treat Mesenteric Ischemia
- When blockage of the mesenteric blood supply is only partial, surgical options include arterial bypass graft (rerouting blood flow around the damaged portion of the artery) and percutaneous transluminal angioplasty (inflation of a tiny balloon, routed via a catheter, at the narrowed point inside the artery to compress the plaque and widen the passageway).
- Complete occlusion requires immediate surgery. The damaged portion of the intestine is removed and the remaining ends sewn together (bowel resection).
- 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.
When to Call a Doctor
- EMERGENCY Call an ambulance immediately if you experience severe, unremitting abdominal pain or cramping, especially if accompanied by other symptoms of mesenteric ischemia.
Johns Hopkins Symptoms and Remedies: The Complete Home Medical Reference
Simeon Margolis, M.D., Ph.D., Medical Editor
Prepared by the Editors of The Johns Hopkins Medical Letter: Health After 50
Updated by Remedy Health Media