Diagnosis and management of spontaneous aortoenteric fistulas.

Spontaneous aortoenteric fistulas are rare but appear to be increasing. They may occur anywhere from the esophagus to the rectum but most often between the duodenum and an infrarenal abdominal aortic aneurysm. Four patients (two with aortoesophageal, one with aortoduodenal, and one with aortocolic fistulas) are presented. The patient usually presents with the clinical triad of aortic aneurysm, pain suggesting aortic disruption, and gastrointestinal hemorrhage. The final exsanguinating hemorrhage is usually preceded by prodomal hemorrhages of varying severity which may be present for weeks to months. Endsocopy is the most helpful diagnostic procedure. Prompt aggressive surgical therapy is the only hope for survival. Successful reconstruction requires placement of the graft in uninfected tissue--often in an extraanatomic position--and interposition of healthy tissues between the graft and the repaired enteric tract.