ERCP with Probe-Based Confocal Laser Endomicroscopy for the Evaluation of Dominant Biliary Stenoses in Primary Sclerosing Cholangitis Patients.

Background and Study Aim: The incidence of cholangiocarcinoma (CCA) in primary sclerosing cholangitis (PSC) ranges between 7 and 14 %. Despite using multiple tissue sampling modalities, detection of CCA remains a challenge. Probe-based confocal laser endomicroscopy (pCLE) has been utilized to visualize subepithelial biliary mucosa in patients with indeterminate strictures. We assessed the technical feasibility and operating characteristics of pCLE in a cohort of PSC patients with dominant biliary strictures (DS). Patients and Methods: This was a chart review of a prospectively maintained database at a single tertiary referral center of 15 PSC patients with 21 dominant stenoses undergoing pCLE. A data collection sheet included demographics, ERCP, cholangioscopy, pCLE (Miami criteria), tissue sampling results, and follow-up to 12 months or liver transplantation. Operating characteristics for pCLE and ERCP tissue sampling were calculated. Results: Sufficient visualization of DS by pCLE was achieved in 20/21 (95 %). pCLE sensitivity, specificity, PPV, and NPV were 100 % (95 % CI 19.3-100 %), 61.1 % (95 % CI 35.8-82.6 %), 22.2 % (95 % CI 3.5-59.9 %), and 100 % (95 % CI 71.3-100 %), respectively, in detecting neoplasia. In comparison, concomitant tissue sampling yielded sensitivity, specificity, PPV, and NPV of 0 % (95 % CI 0-80.7 %), 94.4 % (95 % CI 72.6-99.1 %), 0 % (95 % CI 0-83.5 %), and 89.5 % (95 % CI 66.8-98.4 %), respectively. Conclusions: pCLE achieves a high technical success rate in patients with PSC and DS. This single center, small series, suggests that pCLE may have a high sensitivity and negative predictive value to exclude neoplasia. If verified in larger prospective studies, the technology may be utilized to risk stratify dominant strictures in patients with PSC. [ABSTRACT FROM AUTHOR]