title: Duodenal invasion is a risk factor for the early dysfunction of biliary metal stents in unresectable pancreatic cancer.
abstract: BACKGROUND
  Although the placement of self-expandable metal stents (SEMSs) has been widely accepted as palliation for distal malignant biliary obstruction, the risk factors for their early dysfunction remain unclear.
  
  
  OBJECTIVE
  To identify risk factors for early (<3 months) SEMS dysfunction in unresectable pancreatic cancer.
  
  
  METHODS
  A multicenter retrospective study.
  
  
  METHODS
  Five tertiary referral centers.
  
  
  METHODS
  Patients were included who underwent first-time SEMS placement for distal malignant biliary obstruction caused by pancreatic cancer between April 1994 and August 2010.
  
  
  METHODS
  Rates and causes of early dysfunction were evaluated, and risk factors were analyzed.
  
  
  RESULTS
  In all, 317 eligible patients were identified. Covered SEMSs were placed in 82% of patients. Duodenal invasion was observed endoscopically in 37%. The median time to dysfunction was 170 days. The rates of all and early SEMS dysfunction were 55% and 31%, respectively. The major causes of SEMS dysfunction were food impaction and nonocclusion cholangitis (21% each) in early dysfunction and sludge (29%) in nonearly dysfunction. The rate of early dysfunction was 42% with duodenal invasion and 24% without duodenal invasion (P = .001). Early dysfunction caused by food impaction was more frequent in patients with duodenal invasion (10% and 4%, P = .053). Duodenal invasion was a risk factor (odds ratio 2.35; 95% CI, 1.43-3.90; P = .001) in a multiple logistic regression model.
  
  
  CONCLUSIONS
  A retrospective design.
  
  
  CONCLUSIONS
  Duodenal invasion is a risk factor for early SEMS dysfunction in patients with pancreatic cancer.
authors.affiliation: Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Hamada
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Isayama
authors.forename: Yousuke
authors.initials: Y
authors.lastname: Nakai
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: Toshihiko
authors.initials: T
authors.lastname: Arizumi
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Ito
authors.forename: Saburo
authors.initials: S
authors.lastname: Matsubara
authors.forename: Takashi
authors.initials: T
authors.lastname: Sasaki
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yagioka
authors.forename: Yoko
authors.initials: Y
authors.lastname: Yashima
authors.forename: Dai
authors.initials: D
authors.lastname: Mohri
authors.forename: Kohji
authors.initials: K
authors.lastname: Miyabayashi
authors.forename: Suguru
authors.initials: S
authors.lastname: Mizuno
authors.forename: Rie
authors.initials: R
authors.lastname: Nagano
authors.forename: Naminatsu
authors.initials: N
authors.lastname: Takahara
authors.forename: Nobuo
authors.initials: N
authors.lastname: Toda
authors.forename: Minoru
authors.initials: M
authors.lastname: Tada
authors.forename: Masao
authors.initials: M
authors.lastname: Omata
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Koike
mesh_terms: D000368:Aged; D001655:Bile Reflux / Q000150:complications; D002761:Cholangitis / Q000150:complications; D002779:Cholestasis / Q000628:therapy; D004379:Duodenal Neoplasms / Q000150:complications* / Q000473:pathology; D005260:Female; D005502:Food / Q000009:adverse effects; D006801:Humans; D053208:Kaplan-Meier Estimate; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D010190:Pancreatic Neoplasms / Q000473:pathology*; D011475:Prosthesis Failure / Q000209:etiology*; D012189:Retrospective Studies; D012307:Risk Factors; D015607:Stents / Q000009:adverse effects*; D013997:Time Factors