The incremental benefit of EUS for the identification of malignancy in indeterminate extrahepatic biliary strictures: A systematic review and meta-analysis

This systematic review aims to assess the literature to determine the impact of EUS for diagnosing malignancy among indeterminate extrahepatic biliary strictures. A systematic review was performed using MEDLINE, EMBASE, Cochrane, and conference proceedings from inception to July 2016. Pooled results were calculated using random-effects model, and heterogeneity was explored using stratified meta-analysis and meta-regression. The main outcome was the incremental benefit of EUS (IB(EUS)) for the diagnosis of malignancy among patients who have undergone ERCP with brushing cytology for extrahepatic biliary strictures. Of 3131 identified citations, ten met the inclusion criteria and were included in the final analyses (study periods from 1998 to 2014). Pooled IB(EUS) estimate with the adjustment for publication bias was 14% (95% confidence interval, 7%–20%). Individual studies demonstrate that the IB(EUS) is greater for distal biliary strictures or when an extrinsic mass is identified on cross-sectional imaging. EUS increases the identification of malignancy for indeterminate biliary strictures following a nondiagnostic ERCP, particularly those that are distal or related to extrinsic compression.