Primary aortoduodenal fistula in a patient with pararenal abdominal aortic aneurysm.

Primary aortoenteric fistula is a rare and extremely serious condition. In most cases, it is caused by an abdominal aortic aneurysm presenting with symptoms of gastrointestinal bleeding. Diagnosis is difficult owing to its rarity and the fact that diagnostic tests are not definitive in many cases. Surgery is performed urgently in most cases and is associated with high mortality. We report a case of a 65-year-old man presenting with symptoms of abdominal pain and massive rectal hemorrhage. Computed tomography revealed a pararenal abdominal aortic aneurysm and suspected aortoenteric fistula. The patient underwent an emergency surgery, confirming the suspected diagnosis. The surgery performed was the traditionally recommended extra-anatomical bypass with aortic ligation and repair of the intestinal defect. We describe the clinical condition and provide an up-to-date overview of diagnosis and treatment by reviewing the literature. We believe the therapeutic decision should be personalized by assessing the anatomy of the aneurysm, the patient's clinical status, the degree of local contamination, and the surgeon's experience with each of the techniques.