Primary aortoduodenal fistula due to septic aortitis

We report the second case of a primary aortoenteric fistula resulting from septic aortitis with a contained aortic leak into the retroperitoneum and finally erosion into the duodenum. An emergency laparotomy revealed a fistula between the third part of the duodenum and a decompressed sac (false aneurysm) arising from a nonaneurysmal, grossly infected pararenal aorta. The purpose of this report is to present this rare case in detail and to review primary aortoenteric fistulas reported in the English language literature. Most fistulas form in association with an abdominal aortic aneurysm and rarely are due to infection. Only 6% of patients presented with the classic triad of abdominal pain, a palpable mass, and gastrointestinal bleeding. Although 29% of patients presented with massive hemorrhage, adequate time usually existed for surgical treatment of these complications. A patient with ill-defined abdominal pain and fever who suddenly develops a palpable abdominal mass should have an emergency ultrasound or CT scan to exclude the possibility of an infected aortic aneurysm or a contained rupture of an infected nonaneurysmal aorta. If the symptoms are associated with bleeding and the patient is hemodynamically stable, emergent endoscopy should also be performed. If a primary aortoenteric fistula or an aortic pseudoaneurysm is confirmed, emergent surgery should be undertaken to avoid rupture into the bowel or retroperitoneum.