Update of cholangioscopy and biliary strictures.

Cholangioscopy remains another modality in the investigation of biliary strictures. At cholangioscopy, the "tumour vessel" sign is considered a specific sign for malignancy. Through its ability to not only visualise mucosa, but to take targeted biopsies, it has a greater accuracy, sensitivity and specificity for malignant strictures than endoscopic retrograde cholangiopancreatography guided cytopathological acquisition. Cholangioscopy however, is time consuming and costly, requires greater technical expertise, and should be reserved for the investigation of undifferentiated strictures after standard investigations have failed.