title: Initial performance profile of a new 6F self-expanding metal stent for palliation of malignant hilar biliary obstruction.
abstract: BACKGROUND
  A 6F endoscopic biliary self-expanding metal stent (SEMS) has been newly introduced for intended simultaneous side-by-side bilateral deployment in hilar malignant obstruction.
  
  
  OBJECTIVE
  To report our initial experience with the Zilver 635 biliary SEMS.
  
  
  METHODS
  Retrospective chart review.
  
  
  METHODS
  Tertiary referral medical center.
  
  
  METHODS
  Sixteen consecutive malignant hilar biliary obstruction patients.
  
  
  METHODS
  Endoscopic palliative treatment of malignant biliary obstruction with the Zilver 635 SEMS from December 2008 to January 2010.
  
  
  METHODS
  Technical/functional success rates, early complications (within 30 days of stent placement), early/late stent occlusion, and biliary reintervention rates.
  
  
  RESULTS
  A total of 49 Zilver SEMSs were placed in 16 patients (mean age 61 years, 6 men) for Bismuth type II (n = 4), III (n = 5), and IV (n = 7) lesions. Twelve had cholangiocarcinoma, 2 had metastatic colon cancer, 1 had lung cancer, and 1 had pancreatic cancer. The technical success rate was 100%. Side-by-side simultaneous bilateral stent deployment was required and was achieved successfully in 10 cases. Additional transpapillary stents were placed for potential future biliary access. The 30-day mortality rate was 0%. There were 1 early (6%) and 3 late (19%) stent occlusions. Successful overall biliary drainage was 75%.
  
  
  CONCLUSIONS
  Small sample size, uncontrolled retrospective study.
  
  
  CONCLUSIONS
  Malignant hilar biliary obstruction endoscopic palliation with the Zilver 635 SEMS offers acceptable initial feasibility, safety, and efficacy profiles. The current design facilitates smaller bile duct negotiation and more precise intrahepatic placement. Expanding available lengths would allow transpapillary bridged bilateral SEMS placement for future reobstructed biliary access. Further long-term studies are required for comparative outcomes with other current SEMS technology.
authors.affiliation: Center for Endoscopic Research and Therapeutics, Section of Gastroenterology, Department of Medicine, University of Chicago Medical Center, Chicago, Illinois 60637, USA. jchennat1@uchicago.edu
authors.forename: Jennifer
authors.initials: J
authors.lastname: Chennat
authors.forename: Irving
authors.initials: I
authors.lastname: Waxman
mesh_terms: D000328:Adult; D000368:Aged; D000497:Alloys; D001650:Bile Duct Neoplasms / Q000175:diagnosis / Q000628:therapy*; D018281:Cholangiocarcinoma / Q000175:diagnosis / Q000628:therapy*; D002760:Cholangiopancreatography, Endoscopic Retrograde / Q000295:instrumentation*; D002780:Cholestasis, Intrahepatic / Q000175:diagnosis / Q000628:therapy*; D003110:Colonic Neoplasms / Q000175:diagnosis / Q000628:therapy*; D020698:Duodenoscopes; D004867:Equipment Design; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008113:Liver Neoplasms / Q000556:secondary* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D010166:Palliative Care; D012189:Retrospective Studies; D015607:Stents
chemical_list: D000497:Alloys; C013616:nitinol