Cholangioscopy-directed lithotripsy for a large bile duct stone: the "donut technique".

Conventionally, choledocholithiasis is managed by endoscopic retrograde cholangiopancreatography (ERCP), and it accounts for at least 50% of the approximately 52000 ERCPs performed in the UK each year [1–5]. Bile duct stone clearance traditionally involves the performance of ERCP with biliary sphincterotomy (or sphincteroplasty), followed by the removal of stones from the biliary tree using an extraction balloon, with or without the use of a basket or mechanical lithotripter. Stones may be difficult to remove at ERCP owing to a range of factors, including size (e. g. stones > 15mm), number, location (e. g. intrahepatic or within the cystic duct), and other anatomical factors (e. g. stones above strictures). Cholangioscopy was first introduced in 1975 as a dual-operator “mother–baby” technique and allowed direct visualization of intraductal stones and fragmentation of stones with laser or electrohydraulic lithotripsy (EHL). The technique fell out of widespread use because of technical and endoscopic limitations. In 2006, a single-operator cholangioscope was introduced (Spyglass; Boston Scientific Inc., Natick Massachusetts, USA), which reinvigorated the use of cholangioscopy in the management of difficult bile duct stones. In 2015, a second-generation Spyglass cholangioscope (Spyglass DS; Boston Scientific Inc.) was developed, with improved visualization and scope movement, and a larger (1.3mm) working channel. Here we report the case of a 46-year-old woman who underwent cholangioscopy for an impacted 3-cm common bile duct stone after three failed conventional ERCPs at her local hospital. We elected to perform an ERCP combined with cholangioscopy. Despite visually directed EHL, the stone could not be cracked, and therefore a tunnel was created through the stone (▶Fig. 1), as shown in ▶Video1. This allowed a wire to be passed through the stone, which was then cracked using a dilating balloon. Subsequent uncomplicated stone clearance followed, with successful bile duct clearance.