The additional value of the combined use of EUS and ERCP for the evaluation of unclear biliary strictures.

Objective: Assessing unclear biliary strictures is challenging. We analyzed the diagnostic performance of radiology, EUS, and ERCP.

Methods: All patients referred for EUS and ERCP to assess an unclear biliary stricture were prospectively included. The data from radiology, EUS, ERCP, and tissue sampling were recorded. The diagnostic modalities were analyzed separately and in combination, with a focus on PSC.

Results: Between 2013 and 2020, 78 patients were included; 31% had PSC. A cholangioscopy was not performed in this study. The final diagnosis indicated that the biliary stricture was benign in 62% of the patients and malignant in 38%. The differences among the modalities were numerical, not significant. The modalities showed an accuracy between 78 and 83% in all the patients and between 75 and 83% in the patients with PSC. The combination of radiology and EUS showed the highest sensitivity of 94% in all the patients and a sensitivity of 100% in PSC. Tissue sampling showed the highest specificity of 93% in all patients and 89% in PSC. In 22 cases with combined EUS, ERCP, and tissue sampling, the accuracy, sensitivity, and specificity were 82%, 70%, and 92%, respectively. Minor differences were observed between the intention-to-diagnose analysis and the per-protocol analysis. Adverse events were recorded in 4% of cases.

Conclusion: The combination of EUS and ERCP with tissue sampling seems to be useful and safe for excluding malignancy in unclear biliary strictures. In cases with a reduced suspicion of malignancy, radiology with an EUS may be sufficient.