title: Metallic stent with high axial force as a risk factor for cholecystitis in distal malignant biliary obstruction.
abstract: OBJECTIVE
  Tumor involvement to the orifice of cystic duct (OCD) is a risk factor for cholecystitis after self-expandable metallic stent (SEMS) placement, but its prevention is still difficult. We conducted this multicenter analysis to clarify a type of SEMS or a method to place SEMS which would decrease the incidence of cholecystitis after SEMS placement.
  
  
  METHODS
  The incidence of cholecystitis was studied in consecutive patients receiving SEMS for distal malignant biliary obstruction in five tertiary care centers. Multiple logistic regression analysis was performed to evaluate risk factors for cholecystitis.
  
  
  RESULTS
  A total of 376 patients who received SEMS placement for distal malignant biliary obstruction were analyzed. Tumor involvement to OCD was diagnosed in 25.3%. Overall incidence of cholecystitis was 6.9%. Cholecystitis was observed in 8.0% of 300 patients with covered SEMS, 16.8% of 95 patients with tumor involvement to OCD, 10.8% of 234 patients with SEMS of high axial force (AF), and 12.0% of 158 patients with SEMS length ≤ 60 mm. In the multivariate analysis, tumor involvement to OCD (odds ratio [OR] 5.40, P < 0.001), SEMSs with high AF (OR 5.33, P = 0.002), and SEMS length ≤ 60 mm (OR 3.19, P = 0.010) are risk factors. Among patients with tumor involvement to OCD, the incidence of cholecystitis in SEMS with high and low AF was 25.0% and 5.0%, respectively.
  
  
  CONCLUSIONS
  This study with an expanded cohort reconfirmed tumor involvement to OCD as a risk factor for cholecystitis after SEMS placement. SEMS with low AF might decrease cholecystitis.
authors.affiliation: Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Yousuke
authors.initials: Y
authors.lastname: Nakai
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Isayama
authors.forename: Kazumichi
authors.initials: K
authors.lastname: Kawakubo
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Kogure
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Hamada
authors.forename: Osamu
authors.initials: O
authors.lastname: Togawa
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Ito
authors.forename: Saburo
authors.initials: S
authors.lastname: Matsubara
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Arizumi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yagioka
authors.forename: Naminatsu
authors.initials: N
authors.lastname: Takahara
authors.forename: Rie
authors.initials: R
authors.lastname: Uchino
authors.forename: Suguru
authors.initials: S
authors.lastname: Mizuno
authors.forename: Koji
authors.initials: K
authors.lastname: Miyabayashi
authors.forename: Keisuke
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Takashi
authors.initials: T
authors.lastname: Sasaki
authors.forename: Natsuyo
authors.initials: N
authors.lastname: Yamamoto
authors.forename: Kenji
authors.initials: K
authors.lastname: Hirano
authors.forename: Minoru
authors.initials: M
authors.lastname: Tada
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Koike
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001650:Bile Duct Neoplasms / Q000150:complications; D002764:Cholecystitis / Q000453:epidemiology / Q000209:etiology* / Q000517:prevention & control; D002779:Cholestasis / Q000209:etiology* / Q000628:therapy*; D003549:Cystic Duct; D005260:Female; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D008297:Male; D055595:Mechanical Phenomena; D008670:Metals; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000150:complications; D012189:Retrospective Studies; D012307:Risk Factors; D015607:Stents / Q000009:adverse effects*
chemical_list: D008670:Metals
keywords: cholecystitis; malignant biliary obstruction; mechanical properties; self-expandable metallic stents