Aortoenteric Fistula - Diagnosis and Management Summary

Epidemiology:

• Uncommon but life-threatening

• Most common site of bowel connection is

the duodenum

Clinical Signs/Symptoms:

 • Classic triad: Bleeding, abdominal pain, and palpable abdominal mass - Not reliable, so diagnosis requires high index of suspicion

 • Should be on differential for any patient with known AAA or prior aortic intervention, no matter how long ago

 • Gl bleeding is most common presentation

 • Minor hemorrhage may be herald bleed

 • Massive, life-threatening bleeding or rapid exsanguination

 • Typical "herald bleed": episode of seemingly self-limited gastrointestinal bleeding that precedes a later catastrophic episode of hemorrhage.

Pathophysiology:

 • Primary AEF: arises de novo between aorta and bowel, usually as result of compression of AAA against bowel.

 • Secondary AEF: More common. Develops following any surgical aortic reconstruction; erosion of prosthetic graft into surrounding bowel

Diagnosis:

 • HD unstable patients with massive bleed and known AAA (unrepaired or repaired) should be taken directly to the OR 

 • HD stable patients with acute Gl bleeding may undergo EGD - Sensitivity of EGD for dx AEF is only about 50%

 • Stable patients with a high suspicion for AEF: CTA is first-line study - If negative, EGD should be performed with careful inspection of the distal duodenum.

 • CT findings that correlate strongly with the presence of AEF: Ectopic gas adjacent to or within the aorta, focal bowel wall thickening, discontinuity of the aortic wall, extravasation of contrast material into the bowel lumen.

Management: SURGERY!



- CMC IM Residency @CMC_IM



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