title: Increased Risk of Surgical Site Infection Among Breast-Conserving Surgery Re-excisions.
abstract: OBJECTIVE
  The aim of this study was to determine the risk of surgical site infection (SSI) after primary breast-conserving surgery (BCS) versus re-excision among women with carcinoma in situ or invasive breast cancer.
  
  
  METHODS
  We established a retrospective cohort of women aged 18-64 years with International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) procedure or Current Procedural Terminology, 4th edition (CPT-4) codes for BCS from 29 June 2004 to 31 December 2010. Prior insurance plan enrollment of at least 180 days was required to establish the index BCS; subsequent re-excisions within 180 days were identified. SSIs occurring 2-90 days after BCS were identified by ICD-9-CM diagnosis codes. The attributable surgery was defined based on SSI onset compared with the BCS date(s). A χ (2) test and generalized estimating equations model were used to compare the incidence of SSI after index and re-excision BCS procedures.
  
  
  RESULTS
  Overall, 23,001 women with 28,827 BCSs were identified; 23.2 % of women had more than one BCS. The incidence of SSI was 1.82 % (418/23,001) for the index BCS and 2.44 % (142/5,826) for re-excision BCS (p = 0.002). The risk of SSI after re-excision remained significantly higher after accounting for multiple procedures within a woman (odds ratio 1.34, 95 % confidence interval 1.07-1.68).
  
  
  CONCLUSIONS
  Surgeons need to be aware of the increased risk of SSI after re-excision BCS compared with the initial procedure. Our results suggest that risk adjustment of SSI rates for re-excision would allow for better comparison of BCS SSI rates between institutions.
authors.affiliation: Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA, molsen@dom.wustl.edu.
authors.forename: Margaret A
authors.initials: MA
authors.lastname: Olsen
authors.forename: Katelin B
authors.initials: KB
authors.lastname: Nickel
authors.forename: Julie A
authors.initials: JA
authors.lastname: Margenthaler
authors.forename: Anna E
authors.initials: AE
authors.lastname: Wallace
authors.forename: Daniel
authors.initials: D
authors.lastname: Mines
authors.forename: J Philip
authors.initials: JP
authors.lastname: Miller
authors.forename: Victoria J
authors.initials: VJ
authors.lastname: Fraser
authors.forename: David K
authors.initials: DK
authors.lastname: Warren
mesh_terms: D000293:Adolescent; D000328:Adult; D001943:Breast Neoplasms / Q000150:complications* / Q000601:surgery; D018270:Carcinoma, Ductal, Breast / Q000150:complications* / Q000601:surgery; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000150:complications* / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D015412:Mastectomy, Segmental / Q000009:adverse effects*; D008875:Middle Aged; D008923:Missouri / Q000453:epidemiology; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D011379:Prognosis; D012086:Reoperation; D012189:Retrospective Studies; D012307:Risk Factors; D013530:Surgical Wound Infection / Q000453:epidemiology / Q000209:etiology*; D055815:Young Adult