EVALUATION OF PERORAL VIDEOCHOLANGIOSCOPY USING NARROW-BAND IMAGING FOR DIAGNOSIS OF INTRADUCTAL PAPILLARY NEOPLASM OF THE BILE DUCT

Background: It is very important for intraductal papillary neoplasm of the bile duct (IPNB) to determine the extension of the neoplasms because of substantial differences in the approach to treatment strategy. Peroral videocholangioscopy (PVCS) has been developed as a new diagnostic tool for high resolution imaging of biliary disorders. Recently, narrow-band imaging (NBI) has made it possible to emphasize the imaging of certain features, such as mucosal structures and capillary vessels. The aim of this study is to evaluate the clinical usefulness of PVCS using NBI for the diagnosis of IPNB. Patients and Methods: Four patients (3 men and 1 woman) were eligible for this study as they were scheduled for PVCS for evaluation of IPNB between August 2005 and September 2008 at Tokyo Medical University Hospital. We evaluated endoscopic imaging of white light imaging (WLI) and NBI for IPNB lesions, and ability of removing mucin in the bile duct by PVCS. The quality of the visualization was evaluated. : (i) poor, (ii) fair, and (iii) excellent, compared to WLI and the feasibility of irrigation: (i) poor, (ii) fair, and (iii) excellent, compared to those in patients with non-mucin-producing biliary tract diseases. Results: After sufficient removal of mucin by balloon catheter, conventional cholangioscopy could detect the papillary lesion, and revealed the range of tumor spread in all cases. Interestingly, another papillary lesion far from the main tumor was detected only by PVCS. In the ability to detect the fine mucosal structure, NBI was predisposed to be better than conventional imaging while only one case was "poor" by NBI observation because we could not eliminate the influence of bile. Conclusion: Our results presented here suggest that the depiction ability of the margin of lesions by NBI observation is superior to conventional observation if abundant mucin can be removed sufficiently. Although further cases should be accumulated, choledochoscopy using NBI may be helpful for the observation of fine mucosal structures, resulting in diagnosis of tumor spread in patients with IPNB.