Congenitally absent superior mesenteric artery in an asymptomatic adult.

Congenitally absent superior mesenteric artery is an extremely rare anatomic anomaly with only one other case reported in an adult. We have described an elderly patient who presented with complete absence of the superior mesenteric artery found incidentally on computed tomography imaging. The patient had no abdominal pain, nausea, or other gastrointestinal symptoms. An abnormally enlarged inferior mesenteric artery provided collateral circulation to the midgut. No intervention was performed at the time given the patient's adequate circulation and lack of symptoms. The present case highlights consideration of anatomic mesenteric vascular anomalies before procedures involving inferior mesenteric artery ligation or coverage.