Inferior mesenteric arteriovenous fistula with colonic ischemia: a case report and review of the literature.

Inferior mesenteric arteriovenous fistula is a rare abnormal high flow communication with only 40 primary and secondary cases reported in literature. Shunting of arterial flow through the inferior mesenteric vein to the portal system can cause a variety of nonspecific clinical signs and symptoms usually associated with the diagnosis of arteriovenous malformation. Symptom intensities are flow-dependent and can range from minimal abdominal symptoms to severe heart failure due to left to right shunt. We report the case of a 72-year-old man without past history of abdominal surgery or trauma who was referred to our department for a 2-month history of intermittent diarrhea and abdominal pain caused by an arteriovenous fistula involving the left colic artery and the inferior mesenteric vein. A progressive and spontaneous improvement of symptoms and a control CT scan that confirmed the reduction of venous vascular engorgement and regression of parietal thickening of the left and sigmoid colon permitted a non-operative management.Inferior mesenteric arteriovenous fistula can be a rare cause of ischemic colitis and, if necessary, an appropriate treatment based on high clinical suspicion can reduce the risk of complications related to a missed diagnosis.