title: One- and two-step self-expandable metal stent placement for distal malignant biliary obstruction: a propensity analysis.
abstract: BACKGROUND
  Although self-expandable metal stents (SEMS) are widely used for distal malignant biliary obstruction, one-step SEMS (direct placement without a prior plastic stent) and two-step SEMS (placement at second endoscopic retrograde cholangiopancreatography [ERCP] following plastic stent placement) have not been fully compared.
  
  
  METHODS
  In this multicenter retrospective study, patients were included who underwent first-time endoscopic SEMS placement between September 1994 and December 2010. We compared the one-step and two-step strategies using a propensity analysis.
  
  
  RESULTS
  In total, 370 patients were identified and one-step SEMS was performed in 59 patients. After adjustment using propensity scores, the median times to dysfunction were 116 and 219 days, respectively, for one-step and two-step SEMS (P = 0.058). Stent migration was more frequently observed in one-step SEMS as compared with two-step SEMS (25 vs. 11 %, P = 0.031). In one-step SEMS, the number of days of hospitalization associated with first-time SEMS placement was shorter compared with that in two-step SEMS (21 vs. 30 days, P = 0.001), and the total costs of SEMS-related interventions within 6 months were lower (6510 and 8100 USD, P = 0.004). The pathological diagnosis rates for pancreatic and biliary tract cancer at initial ERCP were 52 and 61 %. After failed diagnosis at initial ERCP, pathological diagnosis rates for pancreatic cancer were 32 versus 76 % (P = 0.005) by repeated ERCP versus endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA).
  
  
  CONCLUSIONS
  One-step SEMS was associated with increased stent migration, despite having potential cost-effectiveness. The additional yield of pathological diagnosis at repeated ERCP was low compared with that yielded by EUS-guided FNA.
authors.affiliation: Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Hamada
authors.forename: Yousuke
authors.initials: Y
authors.lastname: Nakai
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Isayama
authors.forename: Osamu
authors.initials: O
authors.lastname: Togawa
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Kogure
authors.forename: Kazumichi
authors.initials: K
authors.lastname: Kawakubo
authors.forename: Takeshi
authors.initials: T
authors.lastname: Tsujino
authors.forename: Naoki
authors.initials: N
authors.lastname: Sasahira
authors.forename: Kenji
authors.initials: K
authors.lastname: Hirano
authors.forename: Natsuyo
authors.initials: N
authors.lastname: Yamamoto
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Ito
authors.forename: Takashi
authors.initials: T
authors.lastname: Sasaki
authors.forename: Suguru
authors.initials: S
authors.lastname: Mizuno
authors.forename: Nobuo
authors.initials: N
authors.lastname: Toda
authors.forename: Minoru
authors.initials: M
authors.lastname: Tada
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Koike
mesh_terms: D000368:Aged; D001661:Biliary Tract Neoplasms / Q000175:diagnosis / Q000473:pathology / Q000601:surgery*; D044963:Biopsy, Fine-Needle; D002760:Cholangiopancreatography, Endoscopic Retrograde / Q000191:economics / Q000379:methods*; D003362:Cost-Benefit Analysis; D004724:Endoscopy / Q000379:methods; D005260:Female; D005548:Foreign-Body Migration / Q000453:epidemiology; D017048:Health Care Costs; D006801:Humans; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000175:diagnosis / Q000473:pathology / Q000601:surgery*; D057216:Propensity Score; D012189:Retrospective Studies; D015607:Stents / Q000191:economics; D013997:Time Factors; D018084:Ultrasonography, Interventional