Direct visualization of the biliary ductal system is quickly gaining importance among gastroenterologists. Since the inception of cholangioscopy in the 1970s, the technology has progressed, allowing for ease of use, better visualization, and a growing number of indications. Conventional endoscopic retrograde cholangiopancreatography (ERCP) is successful for removal of bile duct stones (with success rates over 90%);1 however, its use in the evaluation of potential biliary neoplasia has been somewhat disappointing. The diagnostic yield of ERCP-guided biliary brushings can range from 30% to 40%.2-4 An alternative to ERCP-guided biliary brushings for biliary strictures is endoscopic ultrasound (EUS)-directed fine needle aspiration (FNA), but the reported sensitivity remains poor, ranging from 43% to 77% with negative predictive values of less than 30%.5-7 These results leave much to be desired for diagnostic yield.
DSOCP appears to have improved accuracy over fiberoptic equipment. In a recent multicenter observational study in patients undergoing digital cholangioscopy, the guided biopsies resulted in adequate tissue for histologic evaluation in 98% of patients. In addition, the sensitivity and specificity of digital cholangioscope-guided biopsies for diagnosis of malignancy was 85% and 100%, respectively.11
Other less common diagnostic indications for DSOCP include evaluation of cystic lesions of the biliary tract, verifying clearance of bile duct stones, bile duct ischemia evaluation after liver transplantation, hemobilia evaluation, removal of a bile duct foreign body, and evaluation of bile duct involvement in the presence of an ampullary adenoma.3,14,15,20,26,27