Advances in direct peroral cholangioscopy using an ultrathin endoscope

Some endoscopists have reported the usefulness of direct peroral cholangioscopy for the diagnosis and therapy of bile duct lesions. Advantages of direct peroral cholangioscopy (POC) using an ultra-slim endoscope include use of conventional endoscopy equipment, operation by a single endoscopist, and superior image quality of the biliary tree with easy application of enhanced endoscopy and a large working channel. Although ultra-slim endoscopes are usually used for direct peroral cholangioscopy, direct scope insertion is considerably difficult. Moreover, this technique still has some severe complications and limitations. Continuous development of specialized endoscopes and accessories is expected to facilitate the diagnostic and therapeutic roles of direct POC.