Comparison of endoscopic retrograde cholangiopancreatography outcomes between cap-fitted forward and side viewing endoscopes in patients with Billroth II anastomosis

BACKGROUND: There have been no previous studies that directly compared outcomes between cap-fitted forward-viewing and side viewing endoscopes (SE). This study aimed to compare the technical success rate and occurrence of adverse events between the side viewing and cap-fitted forward-viewing endoscope (CE) groups among patients with Billroth II anatomy who underwent ERCP. METHODS: The medical records of patients with a previous history of subtotal gastrectomy using Billroth II reconstruction who underwent ERCP at Yeungnam University Hospital between January 2004 and December 2020 were reviewed retrospectively. The patients were divided into CE and SE group. Propensity score matching analysis was performed to minimize selection bias. RESULTS: Propensity score matching resulted in 55 matched pairs for further analysis. Patients’ characteristics were comparable in the matched cohorts. Final success rate of selective bile duct cannulation was not significantly different between the SE and CE groups (98.2% vs. 94.5%, p = 0.308). The complete CBD stone removal rate in CBD stone and successful biliary drainage rate in malignant biliary obstruction were not significantly different between the two groups. The rate of total ERCP-related adverse events was higher in the CE group than in the SE group, but the difference was not statistically significant (10.9% vs. 7.3%, p = 0.507). Among adverse events, the rate of post-ERCP pancreatitis showed higher tendency in the CE group than in the SE group (10.9% vs. 5.5%, p = 0.297). CONCLUSION: In conclusion, CE seems to be equally effective as SE for ERCP in patients with Billroth II anatomy. However, attention should be paid to development of post ERCP complications, especially pancreatitis, when performed by CE.