title: Partially Covered Metal Stents May Not Prolong Stent Patency Compared to Uncovered Stents in Unresectable Malignant Distal Biliary Obstruction.
abstract: OBJECTIVE
  Controversy still exists regarding the benefits of covered self-expandable metal stents (SEMSs) compared to uncovered SEMSs. We aimed to compare the patency and stent-related adverse events of partially covered SEMSs (PC-SEMSs) and uncovered SEMSs in unresectable malignant distal biliary obstruction.
  
  
  METHODS
  A total of 134 patients who received a PC-SEMS or uncovered SEMS for palliation of unresectable malignant distal biliary obstruction were reviewed retrospectively. The main outcome measures were stent patency, stent-related adverse events, and overall survival.
  
  
  RESULTS
  The median stent patency was 118 days (range, 3 to 802 days) with PC-SEMSs and 105 days (range, 2 to 485 days) with uncovered SEMSs (p=0.718). The overall endoscopic revision rate due to stent dysfunction was 36.6% (26/71) with PC-SEMSs and 36.5% (23/63) with uncovered SEMSs (p=0.589). Tumor ingrowth was more frequent with uncovered SEMSs (4.2% vs 19.1%, p=0.013), but migration was more frequent with PC-SEMSs (11.2% vs 1.5%, p=0.04). The incidence of stent-related adverse events was 2.8% (2/71) with PC-SEMSs and 9.5% (6/63) with uncovered SEMSs (p=0.224). The median overall survival was 166 days with PC-SEMSs and 168 days with uncovered SEMSs (p=0.189).
  
  
  CONCLUSIONS
  Compared to uncovered SEMSs, PC-SEMSs did not prolong stent patency in unresectable malignant distal biliary obstruction. Stent migration was more frequent with PC-SEMSs. However, tumor ingrowth was less frequent with PC-SEMSs compared to uncovered SEMSs.
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Soonchunhyang University College of Medicine, Cheonan, Korea.
authors.forename: Jae Yun
authors.initials: JY
authors.lastname: Kim
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Soonchunhyang University College of Medicine, Cheonan, Korea.
authors.forename: Gyu Bong
authors.initials: GB
authors.lastname: Ko
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Soonchunhyang University College of Medicine, Cheonan, Korea.
authors.forename: Tae Hoon
authors.initials: TH
authors.lastname: Lee
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Soonchunhyang University College of Medicine, Cheonan, Korea.
authors.forename: Sang-Heum
authors.initials: SH
authors.lastname: Park
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Soonchunhyang University College of Medicine, Bucheon, Korea.
authors.forename: Yun Nah
authors.initials: YN
authors.lastname: Lee
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Soonchunhyang University College of Medicine, Cheonan, Korea.
authors.forename: Young Sin
authors.initials: YS
authors.lastname: Cho
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Soonchunhyang University College of Medicine, Cheonan, Korea.
authors.forename: Yunho
authors.initials: Y
authors.lastname: Jung
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Soonchunhyang University College of Medicine, Cheonan, Korea.
authors.forename: Il-Kwun
authors.initials: IK
authors.lastname: Chung
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Soonchunhyang University College of Medicine, Bucheon, Korea.
authors.forename: Hyun Jong
authors.initials: HJ
authors.lastname: Choi
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Soonchunhyang University College of Medicine, Seoul, Korea.
authors.forename: Sang-Woo
authors.initials: SW
authors.lastname: Cha
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Soonchunhyang University College of Medicine, Bucheon, Korea.
authors.forename: Jong Ho
authors.initials: JH
authors.lastname: Moon
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Soonchunhyang University College of Medicine, Seoul, Korea.
authors.forename: Young Deok
authors.initials: YD
authors.lastname: Cho
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Soonchunhyang University College of Medicine, Cheonan, Korea.
authors.forename: Sun-Joo
authors.initials: SJ
authors.lastname: Kim
mesh_terms: D000368:Aged; D001650:Bile Duct Neoplasms / Q000150:complications*; D002779:Cholestasis / Q000209:etiology / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010166:Palliative Care / Q000379:methods*; D011475:Prosthesis Failure; D012189:Retrospective Studies; D000069322:Self Expandable Metallic Stents / Q000009:adverse effects*; D016896:Treatment Outcome
keywords: Biliary obstruction; Covered; Metal stent; Patency; Uncovered