Intestinal ischemia and infarction
Intestinal necrosis; Ischemic bowel; Dead bowel; Dead gut
Intestinal ischemia and infarction is the death of part of the intestine due to its blood supply being cut off.
Causes, incidence, and risk factors
There are several possible causes of intestinal ischemia and infarction.
Hernia: If the intestine moves into the wrong place or becomes tangled, this can lead to intestinal ischemia.
Adhesions: The intestine may also become trapped in scar tissue from previous surgery (adhesions), which can lead to ischemia if left untreated.
Embolus: A blood clot from the heart or main blood vessels may travel through the bloodstream and block one of the arteries supplying the intestine. Patients with previous heart attacks or with arrhythmias such as atrial fibrillation are at risk for this problem.
Arterial thrombosis: The arteries that supply blood to the intestine may become so narrowed from atherosclerotic disease (cholesterol buildup) that they become blocked. When this happens in the arteries to the heart, it causes a heart attack. When it happens in the arteries to the intestine, it causes intestinal ischemia.
Venous thrombosis: The veins carrying blood away from the intestines may become blocked by blood clots. This is more common in people with liver disease, cancer, or blood clotting disorders.
Low blood pressure: Very low blood pressure in patients with pre-existing narrowing of the arteries may also cause intestinal ischemia. This typically occurs in patients who are very ill for other reasons and may be compared to losing water pressure in a hose with a partial blockage.
The hallmark of intestinal ischemia is abdominal pain. Vomiting, diarrhea, and in some cases, fever, are also seen.
Signs and tests
Laboratory tests may show an elevated white blood cell (WBC) count (a marker of infection) and increased acid in the bloodstream. A CT scan (special x-ray) of the abdomen may show abnormalities of the intestine.
An angiogram may be obtained. In this study, dye is injected into the arteries that supply the intestine, and x-rays are taken to show the location of the arterial blockage. None of these tests is foolproof, however, and sometimes the only sure way to diagnose ischemic bowel is with exploratory surgery.