title: A prospective randomized study of hydrophilic polymer-coated polyurethane versus polyethylene stents in distal malignant biliary obstruction.
abstract: OBJECTIVE
  Hydrophilic polymer-coated polyurethane (HPCP) stents have a low friction coefficient and a hydrophilic layer, which may reduce biofilm formation and increase the period of stent patency. We compared the patency rates with this new stent with the standard Amsterdam-type polyethylene (PE) stent in a prospective randomized trial.
  
  
  METHODS
  One hundred patients with an unresectable distal malignant bile duct stricture without a previous drainage procedure were randomly assigned to receive either a HPCP stent or a PE stent. The diameter (10 Fr), length (9 cm) and stent design (Amsterdam type) were similar in both stents. Nine patients were excluded. Forty-four patients received an HPCP stent and 47 patients a PE stent. The diagnoses included carcinoma of the pancreas (n = 78), papilla (n = 1), bile duct (n = 10), and metastases (n = 2).
  
  
  RESULTS
  Stent insertion was successful in all patients. Stent dysfunction occurred in 27 of the HPCP stents and 20 of the PE stents, with median stent patency periods of 77 days (95 % CI, 53-101 days) for HPCP stents and 105 days (95 % CI, 42-168 days) for PE stents. The patency period was significantly longer for the PE stent (P = 0.04). Early complications occurred in four patients (4%), one in the HPCP group and three in the PE group.
  
  
  CONCLUSIONS
  Hydrophilic polymer-coated polyurethane stents do not prolong the patency period of biliary stents. In fact, the current standard treatment using polyethylene stents in patients with distal malignant biliary obstruction showed a significantly longer patency period.
authors.affiliation: Dept. of Gastroenterology and Hepatology C2-220, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands. a.m.vanberkel@amc.uva.nl
authors.forename: A M
authors.initials: AM
authors.lastname: van Berkel
authors.forename: M J
authors.initials: MJ
authors.lastname: Bruno
authors.forename: J J G H M
authors.initials: JJ
authors.lastname: Bergman
authors.forename: S J
authors.initials: SJ
authors.lastname: van Deventer
authors.forename: G N J
authors.initials: GN
authors.lastname: Tytgat
authors.forename: K
authors.initials: K
authors.lastname: Huibregtse
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001422:Bacterial Adhesion; D002760:Cholangiopancreatography, Endoscopic Retrograde / Q000295:instrumentation* / Q000379:methods; D002779:Cholestasis / Q000628:therapy*; D020099:Coated Materials, Biocompatible; D003135:Common Bile Duct; D004322:Drainage; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011095:Polyethylenes; D011140:Polyurethanes; D015607:Stents; D016019:Survival Analysis
chemical_list: D020099:Coated Materials, Biocompatible; D011095:Polyethylenes; D011140:Polyurethanes