Direct peroral cholangioscopy using an ultraslim endoscope and overtube balloon-assisted technique: a case series.

Overtube balloon-assisted direct peroral cholangioscopy (POC) using an ultraslim endoscope may be an effective alternative to the conventional mother-baby endoscope system. A total of 14 patients with biliary diseases underwent direct POC with an ultraslim endoscope. The endoscope was successfully advanced into the bile duct in all 14 patients (100 %). The success rate of the POC was 92.9 % (13/14) on the criterion of reaching the hilum or stricture site. Endoscopic biopsy was performed in six patients. Cystic duct or residual common bile duct stones were removed successfully under direct endoscopic visualization in three patients. A diagnosis of malignant or indeterminate bile duct stricture was changed to benign lesion or stricture or normal biliary mucosa in eight of ten patients. Procedure-related biliary tract infection occurred in one patient. This series demonstrated that direct POC using an ultraslim endoscope is useful for both diagnosis and treatment.