Direct peroral cholangioscopy for diagnosis of bile duct lesions using an I-SCAN ultraslim endoscope: a pilot study.

Background and study aims I-SCAN is a computed virtual chromoendoscopy (CVC) system designed to enhance surface and vascular patterns. In this study, we evaluated the usefulness of direct peroral cholangioscopy (POC) using I-SCAN compared with a conventional white-light image (WLI) to diagnose bile duct lesions. Patients and methods Patients with mucosal lesions in the bile duct detected during direct POC were enrolled prospectively. The quality of endoscopic visualization and the visual diagnosis were assessed using I-SCAN and WLI modes, respectively, during direct POC. Results A total of 20 patients (9 malignant and 11 benign lesions) underwent I-SCAN to evaluate lesions in the bile duct using direct POC. The quality of endoscopic visualization using direct POC with I-SCAN was significantly higher than that of WLI for surface structure (P = 0.04), surface microvascular architecture (P = 0.01), and margins (P = 0.02). Overall diagnostic accuracy of the visual diagnosis was not different between I-SCAN and WLI (90.0 % vs. 75.0 %; P = 0.20). Conclusion Direct POC using CVC by I-SCAN seems to be helpful for evaluating mucosal lesions of the bile duct, without the interference from bile. CLINICAL TRIAL REGISTRATION: UMIN000021009. © Georg Thieme Verlag KG Stuttgart · New York.