Endoscopic evaluation of indeterminate biliary strictures: Cholangioscopy, endoscopic ultrasound, or both?

Abstract

Accurate and timely diagnosis of biliary strictures can be challenging. Because the diagnostic sensitivity and accuracy of standard endoscopic retrograde cholangiopancreatography‐based tissue sampling for malignancy are suboptimal, additional endoscopic evaluation by cholangioscopy and/or endoscopic ultrasound (EUS) is often necessary to differentiate between malignant and benign biliary strictures to guide clinical management. While direct visualization by cholangioscopy and/or high‐resolution imaging by EUS are often the first step in the evaluation of an indeterminate biliary stricture (IDBS), tissue diagnosis by cholangioscopy‐guided biopsy and/or EUS‐guided fine‐needle tissue acquisition is the preferred modality to establish a diagnosis of malignancy. Because each modality has its own strengths and limitations, selection of cholangioscopy and EUS is best guided by the biliary stricture location and local expertise. Artificial intelligence‐assisted diagnosis, biopsy forceps with improved design, contrast‐enhanced EUS, and dedicated fine‐needle biopsy devices are recent technological advances that may further improve the diagnostic performance of cholangioscopy and EUS in patients with IDBS.