Biliary Cannulation in Patients with Roux-en-Y Gastrectomy: An Analysis of the Factors Associated with Successful Cannulation

OBJECTIVE: We investigated the results of biliary cannulation using a short-type single-balloon enteroscope in patients with a native papilla who had previously undergone Roux-en-Y gastrectomy and analyzed the factors associated with successful cannulation. METHODS: The study subjects consisted of patients with a native papilla who had previously undergone Roux-en-Y gastrectomy and endoscopic retrograde cholangiopancreatography using a short-type single-balloon enteroscope at our institution between September 2011 and July 2019. We carried out a retrospective investigation of the outcomes, including assessing the success rate of biliary cannulation, and analyzed the factors associated with successful cannulation. RESULTS: In total, 78 patients underwent biliary cannulation of a native papilla. The success rate of biliary cannulation was 80.8% (88.5% when including success on repeated attempts). The success rate of the standard cannulation technique was 60.3%, with the use of advanced cannulation techniques to secure the pancreatic duct providing the same additional effect as a normal anatomy. Adverse events occurred in 9.0% of cases. A multivariate analysis of the Roux-en-Y gastrectomy patients found that cannulation was more likely to be successful in patients in whom the scope could be placed in the retroflex position (odds ratio: 7.88, 95% confidence interval: 2.19-37.77, p＜0.001). CONCLUSION: Selective biliary cannulation using a short-type single-balloon enteroscope in patients with a native papilla who had undergone Roux-en-Y gastrectomy was effective and safe. The retroflex position provided a good papilla field of view and improved the success rate of biliary cannulation.