Background: Infection is a common complication after tissue expander placement. Previously, we have demonstrated that a single dose of peri-operative antibiotic agents is sufficient to achieve an adequately low infection rate for implant exchange procedures. In this follow-up study, we evaluate the efficacy of a similar course of antibiotic prophylaxis regimen for tissue expander placement procedures. Patients and Methods: This is a retrospective study of patients who underwent mastectomy and immediate tissue expander-based reconstruction from July 2011 to April 2021. The primary outcome was breast infection. Student t-test and χ2 tests were used to compare cohorts and complication rates. Multivariable regression analysis was used to identify risk factors for infection. Results: In a 10-year-period, 307 patients (529 breasts) underwent immediate tissue expander reconstruction. Infection occurred in 80 breasts (15.1%). There was no difference in infection rates across pre-pectoral, dual plane, or total submuscular approaches (p = 0.705). Once infection occurred, patients in the dual-plane cohort were more likely to be admitted for intravenous antibiotic treatment (p = 0.007). On multivariable regression analysis, mastectomy skin flap necrosis (p = 0.002), post-operative radiation therapy (p = 0.007), and active smoking (p = 0.007) were significant risk factors for subsequent infection. Conclusions: A short course of peri-operative antibiotic prophylaxis is sufficient for an adequately low infection rate. Mastectomy skin flap necrosis, post-operative radiation therapy, and active smoking placed patients at higher risk for infection. Our results advocate for the conservative use of antibiotic agents while achieving an adequate low infection rate.
