The usefulness of gel immersion endoscopy in identifying herald bleeding from an infectious aortoenteric fistula: a case report.

A 62-year-old male with a history of stent graft replacement for an infectious aortic aneurysm, followed by multiple interventions for postoperative complications, was admitted with melena and anemia. Enhanced computed tomography (eCT) demonstrated fluffing and hyperdensities surrounding the graft, despite no evidence of an aortoenteric fistula (AEF). Emergency esophagogastroduodenoscopy (EGD) showed a massive bleeding in the reconstructed tract and the protruding lesion of postoperative granulation tissue with clots at the end of the blind pouch. Thereafter, hemorrhage temporarily reoccurred several times; however, the source could not be identified using eCT or EGD. Finally, on the third attempt, we performed gel immersion endoscopy (GIE) with manual injection of VISCOCLEAR, and it showed purulent blood flowing from one side of the protruding lesion in the pouch. Based on the eCT findings showing exudation of the contrast agent from the graft into the pouch, we made a diagnosis of an AEF. However, radical surgery was not performed because of the patient's poor general condition. During conservative management, he died of uncontrolled bleeding from the AEF on the 5th day of hospitalization. This is the first case in which the GIE might provide tips to identify herald bleeding from a lethal AEF.