An Overview of the Evolution of Direct Cholangioscopy Techniques for Diagnosis and Therapy.

Direct examination of the biliary tree with endoscopes has been a challenge since endoscopists began performing endoscopic retrograde cholangiopancreatography (ERCP) in the late 1960s. Previously, surgeons had used rigid instruments intraoperatively, which made examination difficult. The first direct cholangioscopy performed by an endoscopist was likely unintentionally done in a patient with postsurgical anatomy. Indirect imaging, ERCP, and percutaneous transhepatic cholangiography are helpful modalities for examining the biliary tree, but they are limited procedures, particularly with regard to the evaluation and treatment of strictures and bile duct stones. This article reviews the history and evolution of direct cholangioscopy since the advent of flexible endoscopes. Additionally, the article describes a new single-operator cholan-gioscopy technique for direct visualization of the biliary tree for diagnosis and intervention. There remains opportunity for innovation as endoscopists strive for safe and less-invasive methods for the identification and treatment of biliary pathology.