Sudden unexpected death as a result of primary aortoduodenal fistula identified with postmortem computed tomography

Aortoenteric fistula (AEF) is an uncommon source of upper gastrointestinal (GI) tract hemorrhage, commonly occurring in persons with previous aortic surgery. Non-surgery related AEFs (primary AEFs) may occur in association with atherosclerotic lesions, infections, malignancies, or, rarely, result from penetrating/eroding foreign bodies. Given its rarity, primary AEF is not commonly considered in the pathologist’s preliminary list of differential diagnoses at the commencement of an autopsy; however, the use of postmortem cross-sectional imaging may allow for the identification of primary AEF as a reasonable differential diagnoses prior to conventional autopsy. The current case outlines the forensic presentation, postmortem computed tomography (PMCT) features, and autopsy findings of a recent case of primary AEF resulting in lethal gastrointestinal hemorrhage. In such cases, PMCT features supporting primary AEF as the underlying cause of death include an atherosclerotic aneurysm abutting a segment of the GI tract with no definite soft tissue plane of separation, luminal GI contents of similar radiographic density to the aortic contents, lack of previous aortic surgery, and lack of a competing explanation for GI hemorrhage or a competing cause of death. Deaths from massive enteric hemorrhage without a medical history to suggest an underlying cause for the hemorrhage would fall under medicolegal jurisdiction and may, by examination of scene and circumstances alone, initially seem suspicious. This case demonstrates how PMCT could be used by a team of expert forensic radiologists and forensic pathologists to rapidly feedback vital information on the cause and manner of death to the criminal justice system.