63. Predictors of Explantation in Periprosthetic Breast Infections: An Analysis Of 180 Breasts

PURPOSE: Post-mastectomy breast reconstruction often involves a multistage process beginning with tissue expander placement to create adequate skin flap surface area. Despite the benefits, infections can occur, posing significant challenges including delay or alteration of adjuvant therapy, prolonged reconstructive timeframes, and increased costs. While medical treatments are often employed to salvage infected expanders and/or implants, surgical interventions may become necessary. Herein, we aim to identify risk factors indicative of an impending explantation in periprosthetic infections. METHODS: This retrospective cohort study examines periprosthetic infections occurring at our center between 2017 and 2019. Patients were identified using CPT codes for tissue expander placement and ICD codes for infection and electronic medical records were reviewed, collecting data on patient demographics, cancer characteristics, medical and surgical cancer treatments, reconstructive procedures, relevant history of breast surgeries, treatments administered for the infection, and the final outcomes. We also assessed the impact of the red breast antibiotic protocol, which constitutes an oral regimen (Minocycline/Linezolid, Ciprofloxacin, and Rifampin) and an intravenous regiment (Minocycline/Vancomycin/Daptomycin, Meropenem/Cefepime, and Rifampin) RESULTS: In the study period, we identified 180 cases of periprosthetic infections, among which 29% (n=53) necessitated explantation. There was no significant association between type of antibiotic regimen and explantation (29.9% versus 28.3% explantation rates in red breast protocol and non-red breast protocols, p =0.828, respectively). Prior chemotherapy and radiotherapy were also insignificant in association with explantation in this population (p = 0.41 and 0.77, respectively). On the other hand, explantation was significantly associated with higher BMI (median, Interquartile range = 30.4 (27.7-34.0) versus 28.6 (24.6-31.7), p = 0.01, in explanted versus non-explanted expanders, respectively), breast cancer histology (64% versus 42% versus 20% versus 16% explantations in invasive lobular carcinoma, invasive ductal carcinoma, ductal carcinoma in-situ, and no cancer histologies, p <0.001, respectively), and breast cancer stage (p<0.001). Multivariate binary logistic regression analysis revealed that BMI (Odds Ratio = 1.2, p < 0.001), expander/implant volume (Odds Ratio = 0.997, p = 0.003), and breast cancer stage (Odds Ratio = 12.2, p < 0.001 in Stage III) independently predicted explantation, while prior chemotherapy and radiotherapy were insignificant. CONCLUSION: Our analysis underscores the significance of prompt and aggressive management in patients with periprosthetic infections, particularly those with higher BMI and advanced breast cancer stage. Notable, the latter was the most prominent risk factor for ultimate explantation, where stage III patients had 13-times the odds of explantation compared to those who had a prophylactic mastectomy.