Aortoenteric Fistula (AEF)-Beware the Upper GI Bleed!

Important points about AEF:

• Most of the time this is a complication of AAA repair (secondary fistula)
• Fistula site normally in the duodenum (the graft erodes into the duodenum)
• "Herald bleed" seen in 20-80% of patients (bleeding stops spontaneously then stops prior to massive hemorrhage)
• Diagnostic studies frequently waste too much time. As a rule of thumb, any unstable patient with a history of AAA repair who presents with a massive GI bleed should probably be taken to the OR for emergent laparotomy. Stable patients may need to get a CT scan and/or EGD (although EGD misses many of these)
• Failure to consider the diagnosis (and act) may lead to bad patient outcomes
• Have a low threshold to call a gastroenterologist AND a surgeon when this diagnosis is being entertained. If you are wrong and it isn't an AEF, no big deal. But if you are correct, you may have saved a life!

Pearl: Suspect a aortoenteric fistula in any patient with a prior AAA repair who presents with an upper GI bleed (may also be lower GI bleed)