[Primary Aorto-enteric Fistula Related to an Aortic Pseudo Aneurysm]

Primary aorto-enteric fistula is a very rare entity, with a high mortality. Direct aortic reconstruction is the preferred treatment, with extra-anatomic revascularization regarded as an alternative. Despite somehow promising results, the role of endovascular exclusion is still under scrutiny.

Male patient, 80 years old, with a history of Micobacterium bovis infection one year ago, and two episodes of gastrointestinal bleeding in the last month. He presented with abdominal pain and hematochezia, was hypotensive and digested blood was found in the nasogastric tube. Anemia (Hb 7,3g/dL) was the only bloodwork remark. Upper and lower endoscopies reported no bleeding nor suspect lesions. Angio-CT showed a pseudo aneurysm of the infra-renal aorta, adherent to the third portion of the duodenum, with findings suggestive of an aorto-enteric fistula; it also showed a thrombosed false aneurysm related to the aorta and left iliac artery. None of these CT findings were reported in a CT done one year before. A right axillo-femoral bypass and crossover femoro-femoral bypass were done, before laparotomy, duodenal repair with jejunal patch and aortic and iliac arteries suture interruption. Good clinical outcome, with discharge from hospital on the 11th post-operative day. One year afterwards no vascular or gastrointestinal events were noticed. No positive microbiological cultures were obtained.

The history of previous Micobacterium infection and the absence of the CT findings one year before this event support the aortic infection as the most likely cause for the fistula, emphasizing the rarity of this case.