Direct Peroral Cholangioscopy by Using an Ultra-slim Upper Endoscope

Currently available peroral cholangioscopy (POC) is a duodenoscopy-assisted procedure that does not involve directly inserting an endoscope into the biliary tree. A prototype multibending (MB) ultra-slim endoscope has been developed as a dedicated cholangioscope to overcome the technical difficulties of direct POC. In this study, the investigators evaluated the efficacy of the new MB ultra-slim endoscope compared with a conventional ultra-slim endoscope for free-hand insertion of an endoscope into the bile duct for direct POC without the assistance of accessories. The primary outcome was the technical success of free-hand insertion of the endoscope during direct POC, which was defined as successful insertion of the endoscope through the ampulla of Vater and advancement of the endoscope up to the bifurcation or to the obstructed segment of the biliary tree without any accessories within 15 min.