LAUSR

ENDOSCOPIC ULTRASONOGRAPHY (EUS)‐ GUIDED antegrade (EUS-AG) treatment is an option to treat bile duct stones (BDS) in surgically altered anatomy patients, but can be technically demanding as a result of the limitation of stone extraction devices. Herein, we presented a case of a difficult BDS successfully removed by two-step EUS-AG treatment after enterobiliary fistula maturation. A 73-year-old man with a history of gastrectomy and Roux-en-Y reconstruction for gastric cancer presented with 12-mm BDS on CT scan (Fig. 1). EUS-AG treatment was attempted after gaining biliary access under EUS and fluoroscopic guidance (Fig. 2). Antegrade balloon extraction, following endoscopic papillary balloon dilation, failed as a result of insufficient dilation of the ampulla, and a nasobiliary drainage tube was temporarily placed. After subsequent extracorporeal shock wave lithotripsy, a second endoscopic session was carried out 2 weeks later. Biliary access was easily obtained through the mature enterobiliary fistula using a duodenoscope. Then, endoscopic mechanical lithotripsy (EML) of BDS was successfully carried out (Fig. 3) using an over-the-wire mechanical lithotripter (Crusher Catheter; Zeon Medical, Tokyo, Japan). Residual stones revealed by intraductal ultrasound (IDUS, Fig. 4) were antegradely extracted using an offset balloon catheter (Extraction Plus Balloon catheter; Zeon Medical). This case illustrates the usefulness of a two-step approach for EUS-AG stone treatment after fistula maturation, previously reported in EUS-AG stent placement for biliary obstruction. Lithotripsy is sometimes necessary for difficult (a)