Novel peroral direct digital cholangioscopy-assisted lithotripsy using a monorail technique through the overtube in patients with surgically altered anatomy (with video).

Efficacy of cholangioscopy-assisted lithotripsy for difficult stones such as huge stones, multiple large stones and an impacted stone in patients with non-altered anatomy has been reported. Herein, we describe peroral direct digital cholangioscopy (PDCS)-assisted electrohydraulic lithotripsy (EHL) with a new technique in patients with surgically altered anatomy. Five patients received PDCS-assisted EHL with the monorail technique due to failed conventional stone extraction. Balloon enteroscope was removed, leaving the stiff guidewire in the bile duct and an overtube with inflated balloons. The cholangioscope was then inserted into the bile duct over the wire through the overtube. After direct visualization of the stone, PDCS-assisted EHL was carried out. This technique was named the 'monorail technique'. Complete removal of biliary stones in one session was accomplished in four patients and only one case required two sessions. There was no adverse event in any of the cases. PDCS-assisted EHL using the monorail technique was effective and safe for difficult biliary stones in patients with surgically altered anatomy.