Secondary Aortoenteric Fistula Causing Intermittent Gastrointestinal Bleeding

Abstract

Introduction: Aortoenteric fistula (AEF) is a pathological communication between the aorta and the gastrointestinal tract (1). We report a rare presentation of a secondary AEF diagnosed by esophagogastroduodenoscopy (EGD) in a patient with a history of bilateral aortoiliac bypass for peripheral arterial disease (PAD) who had a one month history of unexplained, intermittent gastrointestinal bleeding.Figure 1Figure 2Case Presentation: An 85 year-old male, nursing home resident, with extensive history including dementia and PAD with remote bilateral aortoiliac bypass graft presented to the medical intensive care unit (MICU) with one month duration of intermittent hematochezia and new onset hematemesis. The month prior, he had several admissions to a local hospital for hematochezia and anemia in which he was evaluated with both EGD and colonoscopy which failed to identify the source of bleeding. This presentation, patient had hematochezia and hematemsis. His presenting hemoglobin (Hgb) was 6.6 g/dL and nasogastric tube returned 550 mL of bright red blood. Upon transfer, his post transfusion Hgb was 12 g/dL and vitals were stable. Computed tomography angiogram (CTA) showed findings concerning for infected aortobifemoral bypass graft. Urgent EGD revealed a normal esophagus, stomach, duodenal bulb and second portion of the duodenum, but an exposed aortic graft was encountered in the third portion of the duodenum without active bleeding (Image 1 and 2). After further discussion with the patient's family detailing the risks and benefits of surgery, the decision was made to provide the patient with comfort measures only and inpatient hospice. He died one day later. Discussion: An AEF is a conduit between the aorta and the gastrointestinal lumen. Primary AEF forms in patients with no preexisting aortal surgeries (2). A secondary AEF occurs in patients with previous history of reconstructive surgery to the aorta (3). In about one third of cases, the abdominal aorta forms a channel with the duodenum (4, 5). The most common presentation of an AEF is gastrointestinal (GI) bleeding which can vary from herald bleeding to hemorrhagic shock (6-7). The diagnosis of AEF can be made using computed tomography (CT) (9). An EGD is useful in patients with a history of surgical repair to the aorta who present with acute overt gastrointestinal bleeding (7 and 10). Early recognition and diagnosis of AEF is essential as a delay is diagnosis and surgical exploration is almost always fatal (11, 12).