58. Trends in Acellular Dermal Matrix Utilization in Postmastectomy Tissue Expander Placement: An Eleven-year Single Institution Review of 1,237 Patients

PURPOSE: The acellular dermal matrix (ADM) confers demonstrated benefits in device-based breast reconstruction by providing an additional layer for vascularization. The acceptance of ADM in alloplastic reconstruction has created fluctuations in reconstruction patterns over the last decade. This study investigates patterns and clinical outcomes of tissue expander placement with the advent of ADM. METHODS: Patients who underwent placement of tissue expanders for breast reconstruction were identified in a retrospective chart review within a single academic tertiary referral hospital from January 2013 to August 2023. Demographic, oncologic, and clinical characteristics were collected for each patient. Plane of tissue expander placement was classified as subpectoral, dual plane (partial subpectoral with ADM), prepectoral with ADM, and prepectoral without ADM. The main outcome of interest was ADM usage. Backwards stepwise logistic regression was used to assess preoperative predictors of ADM usage and impact of ADM on likelihood of postoperative infection (p<0.05). RESULTS: The final cohort included tissue expander placement for 2,019 breasts among 1,206 patients of five plastic surgeons. The average age was 50.6±11.8 years, and the average BMI was 27.0±6.1 kg/m2. The most common plane of placement was total submuscular (73.9%), followed by dual plane (14.0%), prepectoral with ADM (10.5%), and prepectoral without ADM (1.6%). ADM was used in 494 (24.5%) cases, and the rate of ADM utilization did not experience significant change over the time period of interest (24.4% in 2013-2014 and in 2021-2023). Postoperative infection occurred in 87 (4.3%) cases. In logistic regression, older age (OR: 1.01, 95% CI: 1.00-1.03, p=0.0036), lower BMI (OR: 0.97, 95% CI: 0.95-0.98, p<0.001), and preoperative radiation (OR: 1.69, 95% CI: 1.02-2.81, p=0.0020) predicted higher odds of ADM utilization, whereas diabetes (OR: 0.61, 95% CI: 0.39-0.96, p=0.031) and neoadjuvant chemotherapy (OR: 0.61, 95% CI: 0.45-0.84, p=0.041) predicted significantly lower odds. In another logistic regression model for overall postoperative infection, older age (OR: 1.02, 95% CI: 1.00-1.04, p=0.014), higher BMI (OR: 1.07, 95% CI: 1.04-1.11, p<0.001), and ADM utilization (OR: 3.66, 95% CI: 2.34-5.73, p<0.001) predicted significantly higher likelihood of postoperative infection. CONCLUSION: Whereas the rate of ADM utilization in this institutional study has remained stable over the last decade, the reconstructive approach has changed to favor prepectoral over dual plane placement. ADM utilization is associated with specific preoperative characteristics and comorbidities and independently predicts higher likelihood of postoperative infection in this cohort. Future work may consider more granular definitions of periprosthetic infection.