Asymptomatic Secondary Aortoduodenal Fistula Incidentally Diagnosed During a Health Check-up: A Case Report

Secondary aortoenteric fistulas (AEFs) are an uncommon but fatal complication of abdominal aortic reconstructive surgery. Aortoduodenal fistulas (ADFs) are the most frequent secondary AEFs (80%). The incidence of secondary AEFs is increasing because of the increasing number of individuals undergoing aortic aneurysm repairs with prosthetics. In most cases of secondary AEFs, surgical repair is performed with the patient in a poor condition, owing to late diagnosis. Thus, an early diagnosis is crucial. We report a case of an asymptomatic secondary ADF that was incidentally diagnosed using esophagogastroduodenoscopy (EGD) and computed tomography during a health check-up and was successfully repaired, with the patient in a stable condition even after the development of life-threatening symptoms. Based on our case, we suggest that noticing unexplained leukocytosis in regular hematological examination and performing surveillance EGD in an asymptomatic individual who has undergone abdominal aortic reconstructive surgery may aid in the early diagnosis of secondary AEFs before fatal complications manifest.