Advanced technique for biliary stricture diagnosis using endoscopic ultrasound (EUS)-guided hepaticogastrostomy.

Postoperative benign biliary strictures are major adverse events following biliary surgery. Endoscopic retrograde cholangiography (ERC) is the standard treatment, but it is sometimes challenging in patients with surgically altered anatomy despite the development of balloon enteroscopy [1]. Recently, endoscopic ultrasound (EUS)-guided hepaticogastrostomy (EUS-HGS) has been reported as an effective salvage technique [2, 3]. We report a case in which, after formation of an EUS-HGS fistula, re-intervention and diagnosis of the cause of a stricture were easily performed using intraductal cholangioscopy (IDC; SpyGlass DS system; Boston Scientific Corp., Natick, Massachusetts, USA) through the hepaticogastrostomy route. A 67-year-old man who previously underwent right hepatectomy for hilar cholangiocarcinoma developed repeated episodes of cholangitis because of an anastomotic biliary stricture. Because ERC using a double-balloon enteroscope failed, EUS-HGS was performed and a fully covered metal stent was placed (▶Fig. 1 a). After the fistula hadmatured, brush cytology was attempted to identify the cause of the stricture. Themetal stent was removed, leaving the guidewire, and the brush was inserted (▶Fig. 1b; ▶Video1). A double-pigtail stent was then placed from the anastomotic stricture to the fistula. The brush cytology showed an atypical cell that could not be distinguished as benign or malignant. Brush cytology was then performed repeatedly; however, a diagnosis could still not be made. Therefore, an intraductal cholangioscope was inserted through the hepaticogastrostomy to obtain