Aortoenteric fistulas in the emergency setting: CT findings and diagnostic pitfalls - a pictorial review
Ester Carballo Cuevas, María Paola Moncayo Hinojosa, Elena Luque Beltrán, Jesús Eduardo García López, Sebastián Martín Gill
Emerg Radiol. 2026 Apr;33(2):439-444. doi: 10.1007/s10140-026-02453-7. Epub 2026 Mar 17.
Abstract
Aortoenteric fistulas (AEFs) are rare but life-threatening conditions that may present with nonspecific clinical symptoms in the emergency setting, often leading to delayed diagnosis and high mortality. Computed tomography (CT) angiography plays a pivotal role in their detection and characterization. This pictorial essay reviews and illustrates the spectrum of CT findings of primary and secondary aortoenteric fistulas using representative emergency cases. Emphasis is placed on both direct imaging signs, such as contrast extravasation, visualization of a fistulous tract, and graft migration into the gastrointestinal lumen, and indirect findings, including periaortic gas, loss of the fat plane between the aorta and adjacent bowel, bowel wall thickening, perigraft fluid, and soft-tissue changes. While direct signs are highly specific, they are infrequently observed, whereas indirect signs are more common and often subtle, requiring a high index of suspicion. Common mimics, including perigraft infection and postoperative inflammatory changes, are also discussed, as they may closely resemble aortoenteric fistulas, particularly in the absence of active bleeding. Familiarity with the full spectrum of CT findings, diagnostic pitfalls, and differential diagnoses is essential for early recognition and prompt life-saving management in the emergency department.