Antibiotic prophylaxis and resistance in surgical site infection after immediate tissue expander reconstruction of the breast

Background: A recent survey of plastic surgeons showed that the majority prescribed prophylactic antibiotics after hospital discharge for breast reconstruction. There is no clinical evidence that this practice reduces surgical site infection (SSI) after immediate tissue expander breast reconstruction. Furthermore, multiple studies have suggested that current antibiotic choices may not be appropriately covering the causative organisms of SSI. Methods: An institutional breast reconstruction database from January 2005 to December 2011 was queried to identify patients undergoing immediate tissue expander reconstruction of the breast. The bacteriology of the infection, prophylactic and empiric antibiotic use, and antibiotic sensitivities were analyzed. Results: In 557 cases of immediate tissue expander breast reconstruction performed in 378 patients, SSIs were diagnosed in 50 (9.0%) cases. Two hundred patients were given oral antibiotics at discharge; 178 did not receive antibiotics. Surgical site infection developed in 12.0% of patients given oral antibiotics and in 13.5% of those not receiving antibiotics (P = 0.67). Wound culture data were obtained in 34 SSIs. Twenty-nine had positive cultures. The most common offending organisms were methicillin-sensitive (11) and methicillin-resistant (6) Staphylococcus aureus. Despite increased use of postoperative prophylaxis over the years, SSI incidence remained unchanged. However, trends toward increased resistance of SSI organisms to the preoperative and postoperative prophylaxis agents were observed. When firstgeneration cephalosporins were used as prophylaxis, SSI organisms showed resistance rates of 20.5% (preoperative cefazolin) and 54.5% (postoperative cephalexin). Conclusions: Administration of extended prophylactic antibiotics does not reduce overall risk of SSI after expander-based breast reconstruction but may influence antibiotic resistance patterns when infections occur. The organisms most commonly responsible for SSI are often resistant to cefazolin.