A Rare Presentation of an Aortoenteric Fistula After Aortic Aneurysm Repair

Abstract

Aortoenteric fistula is a well described complication of endovascular repair of abdominal aortic aneurysms (AAA). Aortoenteric fistula formation is rare but potentially life-threatening and has been reported in 0.6%-2% of cases. Multiple causes of aortoenteric fistulas have been described including endograft infection, kinking of endograft within the aorta, or simple erosion of the foreign material. Although acute gastrointestinal bleeding is the most common presentation, chronic gastrointestinal bleeding and asymptomatic presentation have been described. Given its close proximity to the descending aorta, the third portion of the duodenum is the most common location for aortoenteric fistulas. We report an unusual case of an asymptomatic aortoenteric fistula to the duodenal bulb. An 80 year old female with history of chronic obstructive pulmonary disease, hypertension and peripheral vascular disease initially presented with intermittent abdominal pain and hematemesis. CT scan showed an infrarenal 6.5 cm AAA compressing the adjacent duodenum with evidence of air within the thrombus suggesting presence of an aortoenteric fistula to third portion of the duodenum. Patient underwent emergent placement of aortouniiliac endograft stent for repair of AAA by interventional radiology. She was maintained on total parenteral nutrition post procedure. Two months after AAA repair, an upper endoscopy was performed prior to the initiation of oral feeding and showed a 3 cm ulcer with graft material in the duodenal bulb. Patient was asymptomatic at this time with no evidence of gastrointestinal bleeding. There was no evidence of graft infection or migration. Although an unusual location, we believe the patient had developed a second aortoenteric fistula to the duodenal bulb. In recent years, endovascular aneurysm repair is the procedure of choice for repair of infrarenal aortic aneurysms. There have been multiple rare complications associated with this procedure, aortoenteric fistulas being one of the most described. Most patients present with acute gastrointestinal bleeding with fistulas affecting the third portion of the duodenum necessitating endovascular or surgical repair. There are no reported cases of asymptomatic fistulization to the duodenal bulb. Gastroenterologists should be aware of this unusual presentation.Figure 1