Endoscopic sphincterotomy (ES) is not mandatory before biliary stenting. The impact of ES before biliary stent placement remains uncertain. Previous studies have reported that ES can increase adverse event rates by up to 4.5 times compared with no ES. We aimed to assess the occurrence of post-ERCP adverse events following biliary stent placement with and without ES.

PubMed, Embase, and Cochrane databases were systematically searched for randomized controlled trials. The primary outcome was post-ERCP pancreatitis (PEP). Subgroup analyses were performed with patients undergoing biliary drainage due to obstruction, using metal stents, and using plastic stents. Secondary outcomes were postprocedural bleeding, perforation, stent/catheter occlusion, stent/catheter migration, and cholangitis. Heterogeneity was examined with I² statistics, and a random-effects model was used. Review Manager 5.4 was used for statistical analyses.

Seven RCTs with 1022 patients were included. There was no significant difference between the ES and non-ES groups (odds ratio [OR], .46; 95% CI, .19-1.09; P = .08; I² = 59%) regarding PEP; however, a significant difference in bleeding rates was found between groups, favoring non-ES (OR, 7.01; 95% CI, 2.24-21.99; P = .0008; I² = 0%). The analysis of the occurrence of cholangitis (OR, 1.25; 95% CI, .58-2.69; P = .56; I² = 67%), perforation (OR, 1.95; 95% CI, .07-55.73; P = .70; I² = 58%), stent/catheter migration (OR, 2.15; 95% CI, .61-7.57; P = 0.23; I² = 6%), and stent/catheter occlusion (OR, .91; 95% CI, .37-2.25; P = .84; I² = 0%) did not favor either group.

Performing ES before biliary drainage does not affect the PEP rate but is associated with an increased postprocedural bleeding rate.