Endoscopic biliary self-expandable metallic stent in malignant biliary obstruction with or without sphincterotomy: systematic review and meta-analysis.

To assess the rate of adverse events and the technical success rate of biliary stenting with or without EBS.   A literature search up to February 2017 was performed. Studies assessing adverse events (AEs) and technical success rates of stenting with or without EBS were considered.  Seven studies (870 patients; 12 treatment arms) were included. Early AEs, i. e. those occurring within 30 days, were significantly lower in no-EBS vs. EBS-group (11 % vs 20.1 %; OR: 0.36, 95 %CI: 0.13 - 1.00). Rates of post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis were not significantly different in the two groups (no-EBS vs EBS: 6.1 % 5 %; OR: 1.33, 95 %CI: 0.68 - 2.59). The rate of bleeding was significantly lower in patients without EBS (no-EBS vs EBS: 0 % vs 5 %; OR: 0.12, 95 % CI: 0.03 - 0.45). Rates of cholangitis were significantly lower in patients without EBS (no-EBS vs EBS: 3.3 % 7.4 %; OR: 0.38, 95 %CI: 0.17 - 0.83). Both late AEs and mortality rates did not significantly differ between no-EBS and EBS patients (19.9 % vs. 18.9 %; OR: 0.93, 95 %CI: 0.56 - 1.53, and 2.5 % vs. 2.9 %; OR: 1.18, 95 %CI: 0.22 - 6.29, respectively). The technical success rate for stent insertion also did not differ (98 % 97.6 %; OR: 1.05, 95 %CI: 0.42 - 2.63).  EBS seems to be associated, in the first 30 days after the procedure, with an increased risk of cholangitis and bleeding. No difference was observed in the rate of post-ERCP pancreatitis.