title: Expandable metal biliary stenting in patients with recurrent premature polyethylene stent occlusion.
abstract: OBJECTIVE
  Expandable metal stents are currently used to treat biliary tract obstruction. Few data exist on the role of metal stents in patients with recurrent premature plastic biliary stent occlusion. We report our preliminary results using an expandable metal biliary stent with enhanced stent flexibility in this group of patients. Our aim was to assess the efficacy of the Diamond biliary stent in the treatment of recurrent premature biliary plastic stent blockage.
  
  
  METHODS
  From September 1997 to June 1998, six patients with inoperable biliary obstruction and at least one prior episode of plastic stent occlusion were treated with an expandable metal biliary prosthesis. There were four women and six men, with a mean age of 73+/-11 yr. Five patients had malignant biliary obstruction, and one inoperable patient had a biliary stricture secondary to chronic pancreatitis. Patients were followed-up prospectively until either stent occlusion or death. The patency duration of the metal stents was compared to that of the most recently placed plastic stents.
  
  
  RESULTS
  All stents were successfully inserted endoscopically with visualized biliary drainage. No significant immediate postprocedural complications were noted. Median time from initial diagnosis of biliary obstruction to metal stent insertion was 35 wk (range 7-142), during which time patients had occluded a median of 4.5 plastic stents (range 2-5). Median patient survival was 117 days (15-312) and median time to blockage of the last plastic stent was 25.5 days (range 10-90 days). Three cases of metal stent occlusion occurred. One patient had early stent occlusion at 9 days because of debris and sludge clogging the metal stent. Two other patients developed stent occlusion at 120 and 157 days. Two stents remained patent until the patients' deaths at 15 and 87 days. Overall median stent patency was 139 days. The three patients who developed stent occlusion were treated with successful insertion of one or more plastic stents through the existing metal stent. Duration of metal stent patency was significantly longer than that of the last plastic stent (58.8 days longer; 95% CI [6.4, 111]; p = 0.03).
  
  
  CONCLUSIONS
  Metal biliary prostheses represent an effective management strategy for recurrent plastic biliary stent obstruction. Patients in this subgroup may have a shorter duration of metal stent patency than the reported duration of stent patency in patients receiving initial metal stent placement. However the duration of patency still seems to be significantly longer than that of the most recently placed plastic stent.
authors.affiliation: Division of Gastroenterology, McGill University and the McGill University Health Centre, Montreal, Quebec, Canada.
authors.forename: K
authors.initials: K
authors.lastname: Menon
authors.forename: J
authors.initials: J
authors.lastname: Romagnuolo
authors.forename: A N
authors.initials: AN
authors.lastname: Barkun
mesh_terms: D000368:Aged; D001652:Bile Ducts; D002760:Cholangiopancreatography, Endoscopic Retrograde; D002779:Cholestasis / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology / Q000628:therapy; D003251:Constriction, Pathologic; D004867:Equipment Design; D004868:Equipment Failure; D005260:Female; D006801:Humans; D008297:Male; D008670:Metals; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000150:complications; D010195:Pancreatitis / Q000150:complications; D020959:Polyethylene; D012008:Recurrence; D015607:Stents; D016019:Survival Analysis; D013997:Time Factors
chemical_list: D008670:Metals; D020959:Polyethylene