Chronic Mesenteric Ischemia

Chronic mesenteric ischemia (CMI) occurs when intestinal blood flow cannot increase enough to meet the metabolic demand of digestion. The usual cause is atherosclerotic narrowing at the origins of the celiac artery, superior mesenteric artery (SMA), or inferior mesenteric artery. After a meal, the intestine needs substantially more blood flow. A fixed atherosclerotic obstruction prevents that increase, producing predictable postprandial abdominal pain—often called intestinal angina. The patient begins to associate eating with pain, so food intake falls. Progressive weight loss may reflect both food fear and impaired intestinal absorption. The mesenteric arteries have extensive collateral connections. Consequently, a stenosis seen on imaging does not automatically explain abdominal symptoms. Symptomatic atherosclerotic CMI usually reflects severe, long-standing disease in at least two major mesenteric vessels. Single-vessel disease can cause CMI, but it is a weaker explanation and requires more careful exclusion of other diagnoses. The clinical pattern matters as much as the scan: postprandial pain, avoidance of food and weight loss together are far more persuasive than an incidental arterial lesion. CMI is also a marker of systemic atherosclerosis, so coronary, cerebrovascular...