Direct Peroral Cholangioscopy Using an Ultra-Slim Upper Endoscope for the Treatment of Retained Bile Duct Stones

OBJECTIVES: Intracorporeal lithotripsy must be used under direct visual control with an additional endoscope in order to ensure safety and precise targeting during the removal of difficult-to-extract bile duct stones using conventional methods. The currently available "mother-baby" scope system has several disadvantages. We evaluated the feasibility and efficacy of direct peroral cholangioscopy (POC) using an ultra-slim upper endoscope for electrohydraulic lithotripsy (EHL) or laser lithotripsy (LL) for the treatment of difficult-to-extract bile duct stones. METHODS: A total of 18 patients who were unsuccessfully treated for common bile duct (CBD) stones using conventional endoscopy, including mechanical lithotripsy (ML), underwent EHL or LL under intraductal balloon-guided direct POC using an ultra-slim upper endoscope. The balloon catheter was used to maintain access while an ultra-slim upper endoscope was advanced directly into the bile duct. EHL or LL was performed until it became possible to capture the fragmented stones in a basket. Endoscopic removal of stone fragments by duodenoscopy was attempted in the same session. RESULTS: The overall success rate of bile duct clearance by lithotripsy under direct POC by a single endoscopist was 88.9% (16 of 18). Stone fragmentation under direct POC was successfully performed in nine patients using EHL and in seven patients using LL. The average number of treatment sessions required to complete stone removal was 1.6. ML was performed to complete stone removal in 5 of 18 (27.8%) patients. Procedure-related complications were not observed. CONCLUSIONS: Lithotripsy with EHL or LL under direct POC involving the use of an ultra-slim endoscope by a single endoscopist seems to be an effective and safe treatment for select patients with difficult-to-extract CBD stones.