title: Do the benefits of metal stents justify the costs? A systematic review and meta-analysis of trials comparing endoscopic stents for malignant biliary obstruction.
abstract: BACKGROUND
  A variety of stent designs has been studied for endoscopic stenting of the bile duct in patients with malignant biliary obstruction. Although metal stents are associated with longer patency, their costs are significantly higher than plastic stents.
  
  
  OBJECTIVE
  To compare clinical outcome and cost-effectiveness of endoscopic metal and plastic stents for malignant biliary obstruction by a systematic review and meta-analysis of all randomized controlled trials in this area.
  
  
  METHODS
  We conducted searches to identify all randomized controlled trials in any language from 1966 to 2006 using electronic databases and hand-searching of conference abstracts. Meta-analysis was performed with RevMan software [Review Manager (RevMan) version 4.2 for Windows. Copenhagen: The Nordic Cochrane Centre, The Cochrane Collaboration, 2003].
  
  
  RESULTS
  Seven randomized controlled trials were identified that met the inclusion criteria, and 724 participants were randomized to either metal or plastic endoscopic stents. No significant difference between the two stent types in terms of technical success, therapeutic success, 30-day mortality or complications was observed. Metal stents were associated with a significantly less relative risk (RR) of stent occlusion at 4 months than plastic stents [RR, 0.44; 95% confidence interval (CI) 0.3, 0.63; P<0.01]. The overall risk of recurrent biliary obstruction was also significantly lower in patients treated with metal stents (RR, 0.52; 95% confidence interval 0.39, 0.69; P<0.01). The median incremental cost-effectiveness ratio of metal stents was $1820 per endoscopic retrograde cholangiopancreatography prevented.
  
  
  CONCLUSIONS
  Endoscopic metal stents for malignant biliary obstruction are associated with significantly higher patency rates than plastic stents as early as 4 months after insertion. Metal stents will be cost-effective if the unit cost of additional endoscopic retrograde cholangiopancreatographies per patient exceeds $1820.
authors.affiliation: Gastrointestinal Unit, Mater Misericordiae University Hospital, Dublin, Ireland.
authors.forename: Alan C
authors.initials: AC
authors.lastname: Moss
authors.forename: Eva
authors.initials: E
authors.lastname: Morris
authors.forename: Jan
authors.initials: J
authors.lastname: Leyden
authors.forename: Padraic
authors.initials: P
authors.lastname: MacMathuna
mesh_terms: D001661:Biliary Tract Neoplasms / Q000150:complications; D002760:Cholangiopancreatography, Endoscopic Retrograde / Q000191:economics*; D002779:Cholestasis / Q000191:economics / Q000209:etiology / Q000601:surgery*; D003362:Cost-Benefit Analysis; D006801:Humans; D008670:Metals; D010190:Pancreatic Neoplasms / Q000150:complications; D010969:Plastics; D016032:Randomized Controlled Trials as Topic; D012008:Recurrence; D015607:Stents / Q000009:adverse effects / Q000191:economics*; D016896:Treatment Outcome
chemical_list: D008670:Metals; D010969:Plastics