title: Time trend and risk factors for reoperation in Crohn's disease in Japan.
abstract: OBJECTIVE
  We aimed to evaluate time changes in reoperation rate after initial surgery in Crohn's disease (CD) over the last five decades in Japan and to assess the risk factors for reoperation, given that a decrease in the reoperation rate for CD remains controversial.
  
  
  METHODS
  CD patients (n-476) who underwent initial intestinal surgery were examined. Case records were collected from 13 institutions and scrutinized retrospectively. The primary outcome measure was the reoperation rate needing intestinal surgery. To evaluate the time changes, we compared medical treatment and reoperation rate in patients from two different periods of time; before and after 2002 when infliximab became available in Japan (1963-2002 and 2003-2008 groups). Univariate and multivariate analyses were performed to examine the influence of independent variables on the cumulative reoperation rate.
  
  
  RESULTS
  A total of 201 patients underwent reoperation. Overall 5-year and 10-year cumulative reoperation rates were 31.4% and 61.2%, respectively. In multivariate analysis, an onset of the disease between 1963-2002 (p=0.0199) and postoperative administration of infliximab (p=0.0003) and immunosuppressants (p<0.0001) were significant risk factors for reoperation. The cumulative 5-year reoperation rate decreased significantly in the 2003-2008 group compared to the 1963-2002 group (6.3% vs. 32.9%, p<0.05).
  
  
  CONCLUSIONS
  The reoperation rate for CD has decreased significantly in recent years in Japan. However, to further confirm this time trend, we need to evaluate CD patients with a longer follow-up period.
authors.affiliation: Department of Surgery, Teikyo University School of Medicine, Tokyo, Japan. toshwatanabe@yahoo.co.jp
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Watanabe
authors.forename: Iwao
authors.initials: I
authors.lastname: Sasaki
authors.forename: Akira
authors.initials: A
authors.lastname: Sugita
authors.forename: Kohei
authors.initials: K
authors.lastname: Fukushima
authors.forename: Kitaro
authors.initials: K
authors.lastname: Futami
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Hibi
authors.forename: Mamoru
authors.initials: M
authors.lastname: Watanabe
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D003424:Crohn Disease / Q000601:surgery*; D013505:Digestive System Surgical Procedures / Q000639:trends; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D012086:Reoperation / Q000706:statistics & numerical data*; D012307:Risk Factors; D013997:Time Factors