Endoscopic unilateral versus bilateral biliary stenting for the palliation of malignant hilar obstruction: a meta-analysis

Objective To evaluate the efficacy and safety of the unilateral and bilateral drainage in hilar malignant biliary obstruction with a meta-analysis of relevant studies. Methods A systematic electronic search with keywords "biliary stent", "hilar tumor" and "malignant biliary obstruction" was independently performed by two reviewers in major electronic databases of Pubmed, EMBASE, Cochrane Library and Web of Science. A meta-analysis was conducted using Revman 5.1 software. Results Six studies were included with a total number of 558 patients, of whom 307 patients underwent unilateral biliary drainage and 251 patients bilateral drainage. There was no significant difference in early complications (OR=1.03, 95%CI: 0.58-1.81, P=0.93), later complications (OR=0.98, 95%CI: 0.46-2.07, P=0.95), operation success rate (OR=1.42, 95%CI: 0.76-2.66, P=0.28), drainage efficacy or median survival time between the two groups. Compared with unilateral biliary drainage, bilateral biliary drainage had a longer time of stent patency (MD=-29.12, 95%CI: -38.55--19.70, P<0.001). Conclusion Both unilateral and bilateral biliary drainage are safe and effective for hilar malignant biliary obstruction, but more high quality clinical researches are needed. Key words: Cholestasis; Stents; Drainage; Program evaluation; Meta-Analysis