Independent risk factors for infection in tissue expander breast reconstruction.

Background: Postoperative infection in tissue expander breast reconstruction causes increased morbidity, cost, and suboptimal patient outcomes. To improve outcomes, it is important to preoperatively identify factors that might predispose to infection and minimize them when possible. It is hypothesized that certain patient characteristics are associated with an increased infection rate.

Methods: A retrospective, 6-year, single-institution review of patient records was performed from 413 tissue expanders placed in 300 women for postmastectomy breast reconstruction. Infection was defined as any case where antibiotics were given in response to clinical signs of infection. Fourteen potential risk factors were analyzed. A generalized estimation equations approach was used to perform univariable and multivariable analyses.

Results: Antibiotics were given to treat clinical infection in 68 of 413 expanders (16.5 percent), with a median time to diagnosis of 6.5 weeks (range, 1 to 52 weeks). Univariable analysis showed significant association with breast size larger than C cup (p < 0.001), previous irradiation (p = 0.007), repeated implant (p = 0.008), and delayed reconstruction (p = 0.04). All variables except delayed reconstruction remained significant (p < 0.002 for all) in a multivariable model. Additional significant covariates in this model included one surgical oncologist (p = 0.003) and contralateral surgery (p = 0.046). Given infection, one surgical oncologist was associated with an increased rate of mastectomy flap necrosis (p = 0.01).

Conclusions: Certain patient characteristics are associated with increased infection in tissue expansion breast reconstruction. Understanding how these predispose to infection requires additional study. Patients identified with these characteristics should be educated about these risks and other reconstructive options to optimize the success of their breast reconstruction.