BACKGROUND: Aortoenteric fistula is a dreadful and uncommon complication after abdominal aortic aneurysm repair. Continuous friction against the intestine and the aortic graft along with local inflammation is thought to be the major cause of aortoenteric fistula formation, although it is unexpected to have fistula formation with a thrombosed aortic graft.

CASE REPORT: Here, we report a case of an aortoenteric fistula between a thrombosed aortoiliac bypass graft and the duodenum in a 75-year-old male patient who presented with a 2-month history of melena. In this case, the aortoduodenal fistula was repaired with excision of the aortic graft, proximal and distal oversewing of the aorta, omental flap coverage, pyloric exclusion and loop gastrojejunostomy creation.

CONCLUSIONS: An aortoenteric fistula can form through a thrombosed graft. Since this is not an expected route of fistula formation, there may be a delay in identification.

Keywords: Fistula, Gastrointestinal Hemorrhage, Intestinal Fistula, melena, Thrombosis, Tomography, X-Ray Computed, Vascular Fistula, Vascular Grafting