Primary aortoduodenal fistula: a rare cause of massive gastrointestinal hemorrhage

Abstract

Aortoduodenal fistula (ADF) is the most common type of aortoenteric fistula (AEF). This is a rare entity, which produces communication between an abdominal aortic aneurysm (AAA) and the gastrointestinal tract (GIT), resulting in massive gastrointestinal bleeding. AEF/ADF is difficult to recognize clinically, with the classical triad of symptoms including a pulsating, palpable mass, abdominal pain, and GIT bleeding. AEF/ADF can be classified into primary when a communication between an AAA and the GIT develops with no history of prior aortic reconstructive surgery, and secondary, where the communication is on the background of previous aortic reconstructive surgery. Herein we present a case report of a 75-year-old Caucasian male patient with a clinical history of AAA, who presented with massive GIT bleeding and expired shortly after. An autopsy revealed communication between an atherosclerotic AAA and the lower third of the duodenum.

Keywords: Aortic Aneurysm; Autopsy; Digestive System Fistula; Pathology.

Figure 1. Thoracoabdominal CT scan: A – red asterisk indicates the abdominal aortic aneurysm, yellow arrows indicate the calcium aggregated in the atherosclerotic plaque, blue arrow points toward the duodenal lumen and the duodenal wall adjacent to the aneurysm; B – red asterisk indicates the lumen of the aneurysm, the green line indicates the level of section A of the figure. CT: computer tomography.

Figure 2. PADF post-fixation on formalin: A – duodenal side of the fistula (probe placed in the orifice); B – aortic side of the fistula (probe placed in the orifice).

Figure 3. PADF post-fixation on formalin: section through the level of the fistula, the “red star” indicates the lumen of the aortic aneurysm, the “yellow star” indicates the duodenal lumen, white arrow indicates the place of the communication.

Figure 4. Histopathology from the area of penetration of the PADF; yellow asterisk indicates the preserved duodenal mucosa, black arrow indicates hemorrhages in the muscular layer of the duodenum, the red arrow indicates the area of penetration with diffuse hemorrhagic zones, blue arrow indicates the remnants of the aortic wall; hematoxylin and eosin stain, original magnification 40x.