Per-oral cholangioscopy.

Direct endoscopic views of bile duct have been described in literature since the 1970s. Since then rapid strides have been made with the advent of technologically advanced systems with better image quality and maneuverability. The single operator semi-disposable per-oral cholangioscope and other novel methods such as the cholangioscopy access balloon are likely to revolutionize this field. Even though cholangioscopy is currently used primarily for characterization of indeterminate strictures and management of large bile duct stones, the diagnostic and therapeutic indications are likely to expand in future. The following is an overview of the currently available per-oral cholangioscopy equipments, indications for use and future directions.