title: Biliary stenting in patients with malignant biliary obstruction: comparison of double layer, plastic and metal stents.
abstract: OBJECTIVE
  The double layer stent (DLS) has a unique design and has been used for palliation of malignant biliary obstruction, but literature on this stent is limited. Our aim was to compare plastic (PS), DLS and metal stents (MS) in terms of complication rates, time to occlusion, and patency rate in patients with malignant biliary obstruction (MBO).
  
  
  METHODS
  A retrospective review of stents placed for MBO at our institution in the period between January 2009 and April 2011 was conducted. A total of 114 stents were identified, of which 44 were MS (39 %), 37 DLS (32 %), and 33 PS (29 %). A stent was considered occluded when an unplanned stent removal or intervention occurred due to clinical suspicion of biliary obstruction.
  
  
  RESULTS
  Stents remained patent for 95 days (range 7-359 days) in the DLS group and 59 days (range 7-228 days) in the PS group (P = 0.014) and 128.7 days (range 4-602 days) in the metal stent group. Twenty-seven percent (n = 9) of PS occluded after a mean of 60 days while 16 % (n = 7) of MS occluded after a mean of 87 days and 5 % (n = 2) of DLS occluded after a mean of 85 days (DLS vs. PS P = 0.012, DLS vs. MS P = 0.13, MS vs. PS P = 0.22).
  
  
  CONCLUSIONS
  DLS are superior to PS in patients with MBO and appear to be comparable to MS. MS had a longer patency rate but were comparable to DLS in early and late complications. We speculate that the less expensive DLS may be a cost effective alternative in the palliation of MBO.
authors: Department of Internal Medicine, Penn State Milton S. Hershey Medical Center and School of Medicine, Hershey, PA 17033, USA. selwir@hmc.psu.edu
authors: Saleh
authors: S
authors: Elwir
authors: Kaveh
authors: K
authors: Sharzehi
authors: Joshua
authors: J
authors: Veith
authors: Mathew T
authors: MT
authors: Moyer
authors: Charles
authors: C
authors: Dye
authors: Thomas
authors: T
authors: McGarrity
authors: Abraham
authors: A
authors: Mathew
mesh_terms: D000368:Aged; D001650:Bile Duct Neoplasms / Q000150:complications* / Q000000981:diagnostic imaging; D001653:Bile Ducts, Intrahepatic; D018281:Cholangiocarcinoma / Q000150:complications* / Q000000981:diagnostic imaging; D002760:Cholangiopancreatography, Endoscopic Retrograde; D002779:Cholestasis / Q000000981:diagnostic imaging / Q000209:etiology / Q000628:therapy*; D004379:Duodenal Neoplasms / Q000150:complications* / Q000000981:diagnostic imaging; D004868:Equipment Failure; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D010190:Pancreatic Neoplasms / Q000150:complications* / Q000000981:diagnostic imaging; D012189:Retrospective Studies; D015607:Stents; D016896:Treatment Outcome