3210 Aortoenteric Fistula—Rare, Deadly and Obscure

Abstract

INTRODUCTION: Small-bowel bleeding comprises a majority of obscure gastrointestinal bleeding, and is caused by various diseases. For its diagnosis, history-taking, physical examination, diagnostic testing such as cross-sectional imaging, followed by videocapsule endoscopy and deep enteroscopy are all used according to the severity of hemorrhage and patient condition. CASE DESCRIPTION/METHODS: A 74 year old male with an open AAA repair, CKD stage 3, diverticulosis, and ongoing overt obscure GI bleeding × 1.5 years s/p segmental small bowel resection was admitted for an episode of rectal bleeding with hemodynamic instability. He had innumerable upper endoscopies, colonoscopies, video capsule endoscopies and intraop enteroscopy with no clear etiology and had gotten over 70 units of packed RBCs. Records revealed He underwent repeat endoscopy and colonoscopy, but a video capsule endoscopy showed active bleeding in the sigmoid likely from diverticulosis and venous ectasias seen on CTA. He underwent sigmoid resection but bleeding recurred. He then underwent a provoked angiography which was normal. He continued to have bleeding episodes which was characterized by large volume hematochezia and hemodynamic instability. After extensive discussion he underwent a loop ileostomy to determine exact source of his bleeding (small bowel versus colon). Unfortunately 24 hours after surgery, he became unresponsive and developed large volume hematemesis which led to his demise. An autopsy was performed and showed a secondary aortoenteric fistula. This is perhaps one of the only are reported cases of AEF presenting as an obscure GI bleed. DISCUSSION: 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.