Aortoenteric fistulas. Recognizing a potentially catastrophic cause of gastrointestinal bleeding.

Aortoenteric fistulas are a relatively rare but serious cause of massive gastrointestinal hemorrhage. Most occur as a consequence of aortic reconstructive surgery and involve the proximal graft anastomosis. The distal duodenum is the site of bleeding in about three fourths of cases. Most patients have an initial episode of bleeding followed hours to weeks later by catastrophic hemorrhage. Patients with gastrointestinal bleeding who have undergone prior aortic reconstructive surgery should be approached with a great sense of urgency and a high index of suspicion. Endoscopic and radiographic studies can be very helpful, but the absence of abnormalities does not exclude the diagnosis. Exploratory laparotomy is indicated in patients with massive bleeding or those in whom results of other diagnostic studies have been normal. Treatment of aortoenteric fistula is early surgical intervention. Complete excision of the graft is preferred over patching or closing the defect. The mortality rate is essentially 100% without prompt surgical treatment.