Endoscopic evaluation of indeterminate biliary strictures: cholangioscopy, EUS or both?

Accurate and timely diagnosis of biliary strictures can be challenging. Because the diagnostic sensitivity and accuracy of standard ERCP-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. AI-assisted diagnosis, biopsy forceps with improved design, contrast enhanced EUS and dedicated FNB devices are recent technological advances that may further improve the diagnostic performance of cholangioscopy and EUS in patients with IDBS.