Cholangioscopy is the direct endoscopic examination and visualization of the bile ducts. A special, very thin endoscope is used, which is pushed through the working channel of the thicker ERCP device and then into the bile duct. Cholangioscopy is thus an extension of a normal ERCP.
While contrast medium is injected into the bile duct during ERCP and diagnoses such as stones or tumors can then only be made indirectly via contrast medium recesses, the changes can be visualized and depicted directly during cholangioscopy. This then also allows targeted biopsies to be taken or large gallstones to be disintegrated electrohydraulically.