title: Cholecystitis after metallic stent placement in patients with malignant distal biliary obstruction.
abstract: OBJECTIVE
  Cholecystitis after metallic stent (MS) placement is an issue requiring attention. From our experience, cholecystitis seemed to occur mainly in patients with tumor involvement to the cystic duct orifice. The aim of the present study was to identify risk factors for cholecystitis in patients treated with covered or uncovered MS.
  
  
  METHODS
  We analyzed 246 patients who received MS placement (covered MS in 171 and uncovered in 75) between August 1997 and May 2005 for the treatment of unresectable distal malignant biliary obstruction. Causative diseases were as follows: pancreatic cancer in 162, papillary cancer in 10, bile duct cancer in 41, and metastatic nodes in 33 patients. Tumor involvement to orifice of the cystic duct (OCD) was diagnosed based on cholangiography and intraductal ultrasonography.
  
  
  RESULTS
  Cholecystitis after MS placement was found in 13 patients (5.3%). There was no significant difference in the incidence of cholecystitis between covered (5.8%) and uncovered (4.0%) MS. By univariate analysis, tumor involvement of the OCD, MS placed above the papilla, and stricture located at midportion were associated significantly with cholecystitis. By multivariate analysis, only tumor involvement of the OCD was a risk factor, with an odds ratio of 47.206 (95% confidence interval, 5.84-381.60).
  
  
  CONCLUSIONS
  Cholecystitis after MS placement is associated with tumor involvement to the orifice of the cystic duct, regardless of the type of stent.
authors.affiliation: Department of Gastroenterology, Faculty of Medicine, University of Tokyo, Bunkyo-ku, Tokyo, Japan. isayama-2im@h.u-tokyo.ac.jp
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Isayama
authors.forename: Takao
authors.initials: T
authors.lastname: Kawabe
authors.forename: Yousuke
authors.initials: Y
authors.lastname: Nakai
authors.forename: Takeshi
authors.initials: T
authors.lastname: Tsujino
authors.forename: Naoki
authors.initials: N
authors.lastname: Sasahira
authors.forename: Natsuyo
authors.initials: N
authors.lastname: Yamamoto
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Arizumi
authors.forename: Osamu
authors.initials: O
authors.lastname: Togawa
authors.forename: Saburou
authors.initials: S
authors.lastname: Matsubara
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Ito
authors.forename: Takashi
authors.initials: T
authors.lastname: Sasaki
authors.forename: Kenji
authors.initials: K
authors.lastname: Hirano
authors.forename: Nobuo
authors.initials: N
authors.lastname: Toda
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Komatsu
authors.forename: Minoru
authors.initials: M
authors.lastname: Tada
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Yoshida
authors.forename: Masao
authors.initials: M
authors.lastname: Omata
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002764:Cholecystitis / Q000209:etiology*; D001651:Cholestasis, Extrahepatic / Q000209:etiology / Q000473:pathology / Q000601:surgery*; D020099:Coated Materials, Biocompatible; D003549:Cystic Duct; D004067:Digestive System Neoplasms / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008670:Metals; D008875:Middle Aged; D011140:Polyurethanes; D019919:Prosthesis Implantation; D012189:Retrospective Studies; D012828:Silicones; D015607:Stents / Q000009:adverse effects*
chemical_list: D020099:Coated Materials, Biocompatible; D008670:Metals; D011140:Polyurethanes; D012828:Silicones