Recurrent Aortoenteric Fistula

Abstract

Aortoenteric fistula is a rare but often devastating cause of GI bleeding. It is most commonly the secondary type, when a previously placed abdominal aortic graft erodes into the distal duodenum causing a life threatening GI hemorrhage. Fatality is the rule unless it is recognized early and treated promptly. A recurrent aortoenteric fistula is exceedingly rare with only a handful of cases reported in the medical literature. A 64-year-old woman presented with hematemesis and melena. Medical history was remarkable for an abdominal aortic aneurysm s/p uncomplicated elective graft repair in 1993 with subsequent development of an aortoduodenal fistula in 2000 manifested as severe GI bleeding. This was managed at our institution with emergent surgery (infected graft removal, over-sewing of the aorta, and creation of a axillary-femoral artery bypass) with full recovery. On physical exam the patient appeared comfortable. She was orthostatic and had a clean vertical abdominal scar without a pulsatile mass. Abdomen was soft and not-tender. Emergent EGD utilizing a pediatric colonoscope revealed a significant amount of non-adherent blood clots in the descending duodenum without active bleeding. No lesions or active bleeding sites were identified on the examination. A CT scan and technetium 99m pertechnetate tagged RBC scan revealed active bleeding in the distal duodenum adjacent to an aneurysmal abdominal aortic stump. Emergent laparotomy revealed a large aortic stump pseudoaneurysm with a pin size hole communicating with the distal duodenum. The pseudoaneurysm and duodenum were repaired and the fistulous communication was excised. An omentoplasty was performed in order to buffer the separation between the aortic stump and duodenum. The patient had an uneventful post-operative course and was discharged to a rehabilitation facility twelve days later. This most unusual case highlights the importance of recognizing the clinical presentation of an aortoenteric fistula and how it is an infrequent but often lethal cause of severe GI bleeding. Moreover, although such cases are quite rare, it does not preclude its recurrence. One must approach each patient with severe GI tract bleeding with a broad differential diagnosis keeping in mind both their current risk factors as well as their past history.