Usefulness of endoscopic ultrasonography with a microprobe in the diagnosis of aortoesophageal fistula.

Aortoesophageal fistula (AEF) is very rare and is associated with a high mortality rate. AEF manifests with massive gastrointestinal bleeding and is difficult to diagnose from endoscopic findings and clinical features. We encountered a patient with an AEF that was promptly diagnosed by endoscopic ultrasonography (EUS) using a microprobe. A 58-year-old man was admitted to our hospital because of hematemesis. Endoscopic examination revealed a submucosal tumor (SMT)-like lesion 2 cm in diameter 25 cm from the dental arch. EUS with a 20-MHz microprobe revealed a blood vessel-like structure with hypoechoic flowing contents and a high echoic area suggestive of a thrombus protruding into the esophageal lumen. AEF resulting from a ruptured thoracic aortic aneurysm was suggested from the EUS findings and was definitely diagnosed by computed tomography. Graft replacement of the descending aorta was successfully performed. The patient is now in good health 6 years after the first admission. This is the first report of a case of AEF diagnosed by EUS with a microprobe.