Effect of immediate reconstruction on postmastectomy surgical site infection.

INTRODUCTION: Surgical site infections (SSI) are a source of significant postoperative morbidity and cost. Although immediate breast reconstruction after mastectomy has become routine, the data regarding the incidence of SSI in immediate breast reconstruction is highly variable and series dependent.
METHODS: Using the National Surgical Quality Improvement Program database, all female patients undergoing mastectomy, with or without immediate reconstruction, from 2005 to 2009 were identified. Only "clean" procedures were included. The primary outcome was incidence of SSI within 30 days of operation. Stepwise logistic regression analysis was used to identify risk factors associated with SSI.
RESULTS: A total of 48,393 mastectomies were performed during the study period, of which 9315 (19.2%) had immediate breast reconstruction. The incidence of SSI was 3.5% (330/9315) (95% CI [confidence interval]: 3.2%-4%) in patients undergoing mastectomy with reconstruction and 2.5% (966/39,078) (95% CI: 2.3%-2.6%) in patients undergoing mastectomy without reconstruction (P < 0.001). Independent risk factors for SSI include increased preoperative body mass index (BMI), heavy alcohol use, ASA (American Society of Anesthesiologists) score greater than 2, flap failure, and operative time of 6 hours or longer.
CONCLUSIONS: Immediate breast reconstruction is associated with a statistically significant increase in risk of SSI in patients undergoing mastectomy (3.5% vs 2.5%). However, this difference was not considered to be clinically significant. In this large series, increased BMI, alcohol use, ASA class greater than 2, flap failure, and prolonged operative time were associated with increased risk of SSI.