Diagnosis and management of aortoenteric fistulas

Development of an aortoenteric fistula (AEF) is a devastating and life-threatening condition, which is as difficult to diagnose as it is to treat. Fortunately, it is rare, most commonly seen as a delayed complication of aortic reconstruction. Two types are recognized: primary and secondary. Primary fistulas occur de novo between the aorta and bowel, most commonly duodenum. Secondary fistulas occur between an aortic graft and segment of bowel. Diagnosis of AEF requires a high index of suspicion in patients who present with either signs of infection or gastrointestinal hemorrhage. Early diagnosis is essential for a successful outcome because of the lethal nature of AEF. Symptomatology can be varied but most often includes signs of infection and of gastrointestinal bleeding. Esophagogastroduodenoscopy (EGD) and computed tomography (CT) scans are the most useful tests to diagnose AEF. Treatment almost always requires excision of the infected graft and revascularization. Placement of an extra anatomic bypass, followed by graft excision, has been the usual treatment. Recent experience with in situ revascularization has shown that a variety of materials can be use for in situ reconstruction with good results. Morbidity and mortality rates still are high even in contemporary series. The mortality rate still is approximately 33%, but amputation rates have been reduced to less then 10%. Care of patients with AEF requires timely control of bleeding and infection followed by vascular reconstruction performed in a manor to minimize physiological stress.