title: Comparison of the efficacy of covered versus uncovered metallic stents in treating inoperable malignant common bile duct obstruction: a randomized trial.
abstract: OBJECTIVE
  To compare patency and overall survival achieved with covered versus uncovered metallic stents among patients with inoperable malignant extrahepatic biliary obstruction.
  
  
  METHODS
  There were 40 patients enrolled in this prospective randomized study between January 2012 and July 2013. Mean age of patients was 62.6 years (range, 43-86 y). The malignancies causing extrahepatic biliary obstruction were pancreatic cancer (n = 18), stomach cancer (n = 13), gallbladder cancer (n = 3), common bile duct cancer (n = 2), and other cancer types (n = 4). Uncovered (n = 20) and covered (n = 20) stents were used. Stent patency, overall survival, and complications were evaluated and statistically compared.
  
  
  RESULTS
  Mean patency of uncovered stents (413.3 d ± 63.0) was significantly longer than mean patency of covered ones (207.5 d ± 46.0; P = .041). Mean overall survival was 359.9 days ± 61.5 for uncovered stents, which was statistically similar to survival of 350.5 days ± 43.8 for covered stents (P = .271). Causes of recurrent obstruction included tumor ingrowth (n = 2), tumor overgrowth (n = 5), debris or food material (n = 5), and stent migration (n = 2). One case of acute cholecystitis occurred in covered stent group.
  
  
  CONCLUSIONS
  Uncovered metallic stents had superior patency duration than covered stents for patients with malignant extrahepatic biliary obstruction. However, the overall complication and survival rates achieved with covered and uncovered stents were similar.
authors.affiliation: Department of Radiology, Research Institute of Radiological Science, Yonsei University College of Medicine, 50 Yonsei-ro, Shinchon-dong, Seodaemun-gu, Seoul 120-752, Republic of Korea.
authors.forename: Shin Jae
authors.initials: SJ
authors.lastname: Lee
authors.affiliation: Department of Radiology, Research Institute of Radiological Science, Yonsei University College of Medicine, 50 Yonsei-ro, Shinchon-dong, Seodaemun-gu, Seoul 120-752, Republic of Korea. Electronic address: mdkim@yuhs.ac.
authors.forename: Man Deuk
authors.initials: MD
authors.lastname: Kim
authors.affiliation: Department of Radiology, Research Institute of Radiological Science, Yonsei University College of Medicine, 50 Yonsei-ro, Shinchon-dong, Seodaemun-gu, Seoul 120-752, Republic of Korea.
authors.forename: Myung Su
authors.initials: MS
authors.lastname: Lee
authors.affiliation: Department of Radiology, Research Institute of Radiological Science, Yonsei University College of Medicine, 50 Yonsei-ro, Shinchon-dong, Seodaemun-gu, Seoul 120-752, Republic of Korea.
authors.forename: Il Jung
authors.initials: IJ
authors.lastname: Kim
authors.affiliation: Department of Radiology, Research Institute of Radiological Science, Yonsei University College of Medicine, 50 Yonsei-ro, Shinchon-dong, Seodaemun-gu, Seoul 120-752, Republic of Korea.
authors.forename: Sung Il
authors.initials: SI
authors.lastname: Park
authors.affiliation: Department of Radiology, Research Institute of Radiological Science, Yonsei University College of Medicine, 50 Yonsei-ro, Shinchon-dong, Seodaemun-gu, Seoul 120-752, Republic of Korea.
authors.forename: Jong Yoon
authors.initials: JY
authors.lastname: Won
authors.affiliation: Department of Radiology, Research Institute of Radiological Science, Yonsei University College of Medicine, 50 Yonsei-ro, Shinchon-dong, Seodaemun-gu, Seoul 120-752, Republic of Korea.
authors.forename: Do Yun
authors.initials: DY
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019917:Blood Vessel Prosthesis Implantation / Q000379:methods; D001651:Cholestasis, Extrahepatic / Q000209:etiology* / Q000601:surgery*; D003135:Common Bile Duct / Q000601:surgery; D003952:Diagnostic Imaging / Q000379:methods; D004067:Digestive System Neoplasms / Q000150:complications*; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010166:Palliative Care / Q000379:methods*; D011446:Prospective Studies; D015607:Stents; D016019:Survival Analysis; D016896:Treatment Outcome; D014654:Vascular Patency
keywords: PTBD; percutaneous transhepatic biliary drainage