title: Plastic vs. Self-Expandable Metal Stents for Palliation in Malignant Biliary Obstruction: A Series of Meta-Analyses.
abstract: Self-expandable metal stents (SEMS) are thought to have an advantage over plastic stents in achieving biliary drainage.
  
  
  
  We performed a systematic search of MEDLINE, EMBASE, Scopus, CENTRAL, and ISI Web of knowledge databases, from January 1980 to September 2015, for randomized-controlled trials (RCTs) comparing SEMS vs. plastic stents in the palliation of malignant biliary obstruction. Primary outcomes were durations of stent patency, patient survival, and 30-day mortality. Numerous secondary outcomes were assessed, and extensive sensitivity and subgroup analyses were performed.
  
  
  
  In all, 20 RCTs totaling 1,713 patients yielded a weighted mean difference (WMD) in time to stent patency (4 studies) of 4.45 months (95% confidence interval (CI), 0.31, 8.59; GRADE=moderate) favoring SEMS. There were no differences in overall patient survival (5 studies) WMD=0.67 months (95% CI, -0.66, 1.99; GRADE=moderate), or 30-day mortality (8 studies) odds ratio (OR)=0.80 (95% CI, 0.52, 1.24; GRADE=moderate) but there was a higher symptom-free survival at 6 months (4 studies) OR=5.96 (95% CI, 1.71, 20.81; GRADE=moderate). SEMS use resulted in lower rates of late complications (11 studies) OR=0.43 (95% CI, 0.26, 0.71; GRADE=moderate), sepsis or cholangitis (14 studies) OR=0.53 (95% CI, 0.37, 0.77; GRADE=high), blocking from sludge (8 studies) OR=0.11(95% CI, 0.07, 0.17; GRADE=moderate), and mean number of re-interventions (8 studies) WMD=-0.83 interventions (95% CI, -1.64, -0.02; GRADE=moderate). There was a longer patency of SEMS for those without a prior drainage attempt (2 studies) WMD 7.70 months (95% CI, 7.14, 8.25; GRADE=high). Although a survival advantage was found when an uncovered SEMS was used (3 studies) WMD 1.31 months (95% CI, 0.30, 2.32; GRADE=high), but not partially or fully covered SEMS (2 studies) WMD -0.66 months (95% CI, -1.02, -0.30; GRADE=high) vs. plastic stents, and for SEMS in the setting of pre- or post-procedural antibiotic administration (2 studies) WMD 1.49 months (95% CI, 0.27, 2.70; GRADE=high), and performance of a sphincterotomy (2 studies) WMD 1.63 months (95% CI, 0.42, 2.84; GRADE=high).
  
  
  
  Keeping in mind the noted risk of bias in source data, the use of SEMS compared with plastic stents, in the palliation of patients with malignant biliary obstruction results in longer stent patency, lower complications rates, and fewer re-interventions, whereas exhibiting survival benefits in selected subgroups of patients.
authors.affiliation: Division of Gastroenterology, The McGill University Health Center, Montreal General Hospital, McGill University, Montreal, Canada.|Division of Gastroenterology, King Khalid University Hospital, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Majid A
authors.initials: MA
authors.lastname: Almadi
authors.affiliation: Division of Gastroenterology, The McGill University Health Center, Montreal General Hospital, McGill University, Montreal, Canada.|Division of Clinical Epidemiology, The McGill University Health Center, Montreal General Hospital, McGill University, Montreal, Canada.
authors.forename: Alan
authors.initials: A
authors.lastname: Barkun
authors.affiliation: Division of Gastroenterology, The McGill University Health Center, Montreal General Hospital, McGill University, Montreal, Canada.
authors.forename: Myriam
authors.initials: M
authors.lastname: Martel
mesh_terms: D002761:Cholangitis / Q000453:epidemiology; D002779:Cholestasis / Q000209:etiology / Q000601:surgery*; D004322:Drainage; D006801:Humans; D010166:Palliative Care; D010190:Pancreatic Neoplasms / Q000150:complications; D010969:Plastics; D011183:Postoperative Complications / Q000453:epidemiology; D000069322:Self Expandable Metallic Stents; D018805:Sepsis / Q000453:epidemiology; D015607:Stents
chemical_list: D010969:Plastics