Risk of Pancreatitis Following Biliary Stenting With/Without Endoscopic Sphincterotomy: A Randomized Controlled Trial.

BACKGROUND & AIMS:The efficacy of endoscopic sphincterotomy (ES) before endoscopic transpapillary biliary drainage in preventing post-endoscopic retrograde cholangiopancreatography pancreatitis (PEP) has not been established. The aim of this study was to evaluate the effect of performing ES before biliary stent/tube placement on the occurrence of PEP. METHODS:Three hundred seventy patients with biliary stricture requiring endoscopic biliary stenting were enrolled and randomly allocated to the ES group (n = 185) or non-ES group (n = 185). All participants were followed up for 30 days after the procedure. The data and occurrence of adverse events were prospectively collected. The primary outcome measure of this study was the incidence of PEP within 2 days of initial transpapillary biliary drainage. Secondary outcome measures were the incidence of other adverse events related to biliary stent/tube placement. RESULTS:PEP occurred in 36 patients (20.6%) in the non-ES group and in 7 patients (3.9%) in the ES group (P < .001). The difference in the incidence of PEP between the 2 groups in the per-protocol population was 16.7% (95% confidence interval, 10.1%-23.3%), which was not within the noninferiority margin of 6%. Except for bleeding, the incidences of other adverse events were not significantly different between the groups. CONCLUSION:ES before endoscopic biliary stenting could have the preventive effect on the occurrence of PEP in patients with biliary stricture. University Hospital Medical Information Network Number, UMIN000025727.University Hospital Medical Information Network Clinical Trial Registry URL: https://www.umin.ac.jp/ctr/index.htm.