title: Penetrating or stricturing diseases are the major determinants of time to first and repeat resection surgery in Crohn's disease.
abstract: BACKGROUND
  About 80% of patients with Crohn's disease (CD) require bowel resection and up to 65% will undergo a second resection within 10 years. This study reports clinical risk factors for resection surgery (RS) and repeat RS.
  
  
  METHODS
  Retrospective cohort study, using data from patients included in the Swiss Inflammatory Bowel Disease Cohort. Cox regression analyses were performed to estimate rates of initial and repeated RS.
  
  
  RESULTS
  Out of 1,138 CD cohort patients, 417 (36.6%) had already undergone RS at the time of inclusion. Kaplan-Meier curves showed that the probability of being free of RS was 65% after 10 years, 42% after 20 years, and 23% after 40 years. Perianal involvement (PA) did not modify this probability to a significant extent. The main adjusted risk factors for RS were smoking at diagnosis (hazard ratio (HR) = 1.33; p = 0.006), stricturing with vs. without PA (HR = 4.91 vs. 4.11; p < 0.001) or penetrating disease with vs. without PA (HR = 3.53 vs. 4.58; p < 0.001). The risk factor for repeat RS was penetrating disease with vs. without PA (HR = 3.17 vs. 2.24; p < 0.05).
  
  
  CONCLUSIONS
  The risk of RS was confirmed to be very high for CD in our cohort. Smoking status at diagnosis, but mostly penetrating and stricturing diseases increase the risk of RS.
authors.affiliation: Healthcare Evaluation Unit, Institute of Social and Preventive Medicine, Lausanne, Switzerland. Valerie.Pittet@chuv.ch
authors.forename: Valerie
authors.initials: V
authors.lastname: Pittet
authors.forename: Gerhard
authors.initials: G
authors.lastname: Rogler
authors.forename: Pierre
authors.initials: P
authors.lastname: Michetti
authors.forename: Nicolas
authors.initials: N
authors.lastname: Fournier
authors.forename: John-Paul
authors.initials: JP
authors.lastname: Vader
authors.forename: Alain
authors.initials: A
authors.lastname: Schoepfer
authors.forename: Christian
authors.initials: C
authors.lastname: Mottet
authors.forename: Bernard
authors.initials: B
authors.lastname: Burnand
authors.forename: Florian
authors.initials: F
authors.lastname: Froehlich
mesh_terms: D000328:Adult; D003424:Crohn Disease / Q000453:epidemiology / Q000473:pathology / Q000601:surgery*; D013505:Digestive System Surgical Procedures / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D007422:Intestines / Q000473:pathology; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D012086:Reoperation / Q000706:statistics & numerical data; D012189:Retrospective Studies; D012307:Risk Factors; D013557:Switzerland / Q000453:epidemiology