Determinants of surgical site infection after breast surgery

Background: Surgical site infection (SSI) after breast procedures may result in significant morbidity: psychologic trauma, and additional cost. SSI rates in patients at the Cleveland Clinic Foundation having biopsy, partial mastectomy: or modified radical mastectomy were higher during April and May 1995 than during the previous 12 months (8 infections for 74 procedures [10.8%] vs 10 for 378 [2.6%]; p < 0.006). Since 1993 one surgeon has performed most of these procedures, with no change in operative technique, skin preparation, or surgical team. A case-control study was performed to identify risk factors for infection. Methods: A case patient was defined as any patient having a breast procedure from April 1994 through May 1995 with culture of a pathogen from surgical site drainage or aspiration or with erythema or presence of cellulitis treated by incision and drainage and/or antibiotic therapy Randomly selected control patients were matched by time and procedure. There were 18 case patients and 37 control patients. Results: Factors associated with SSI were obesity (78% of cases vs 40% of controls; p = 0.02) and older age (mean 66 years in cases vs 56 years in controls; p = 0.005). After introduction of cefazolin sodium prophylaxis, SSI rate was reduced to 0.9% (3 infections for 332 procedures). Conclusions: Host factors may contribute to SSI in breast procedures. Cefazolin sodium prophylaxis was useful in preventing SSI after breast surgery.