Effect of endoscopic biliary drainage with/without endoscopic sphincterotomy on post-ERCP pancreatitis in patients with biliary stricture (E-BEST): a multicenter randomized controlled trial

Background and Aims
The efficacy of endoscopic sphincterotomy (ES) before endoscopic biliary stenting (EBS) in preventing post-ERCP pancreatitis (PEP) has not been established. The aim of this study was to evaluate the noninferiority of not performing ES before EBS with regard to the occurrence of PEP.
Methods
370 patients with biliary stricture requiring EBS were enrolled and randomly allocated to 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 EBS. Secondary outcome measures were the incidence of other adverse events related to EBS.
Results
PEP occurred in 36 (20.6%) patients in the non-ES group and in 7 (3.9%) patients in the ES group (p < 0.001). The difference in the incidence of PEP between two 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
The noninferiority of non-ES to ES before EBS was not proven for the occurrence of PEP. ES before EBS could be superior to non-ES.