Clinical meaning
Chronic mesenteric ischemia (CMI) results from atherosclerotic stenosis of the mesenteric arteries (celiac, SMA, IMA), causing inadequate blood flow to the gut during periods of increased metabolic demand (postprandial state). At least two of the three mesenteric arteries are typically stenosed > 70% before symptoms develop due to extensive collateral circulation. Postprandial pain (intestinal angina) occurs because the diseased vessels cannot increase blood flow to meet the metabolic demands of digestion. Chronic mucosal ischemia leads to villous atrophy, malabsorption, and progressive weight loss. CMI is a precursor to acute mesenteric ischemia, which carries > 50% mortality.
Diagnosis & workup
Diagnostics & workup: - CTA of the abdomen (gold standard for mesenteric arterial visualization) - Mesenteric duplex ultrasound (fasting; measures peak systolic velocities) - MRA of mesenteric vessels (alternative if contrast contraindicated) - Conventional angiography (diagnostic and therapeutic) - Evaluate for malnutrition: albumin, prealbumin, vitamin levels - Stool guaiac for occult GI bleeding - Upper endoscopy may show mucosal ischemia in duodenum