98. Vitamin D Insufficiency Impacts Outcomes in Autologous Microvascular Breast Reconstruction

PURPOSE: Nutritional status can significantly impact postoperative recovery and outcomes. Insufficiencies in nutritional markers such as albumin and vitamin D (25-hydroxyvitamin D or 25-OHD) have been associated with surgical infections in animal models as well as increased mortality, infection, and length of stay in clinical studies of surgical patients. However, no study has evaluated the impact of 25-OHD on surgical outcomes following autologous breast reconstruction (ABR). This study aims to evaluate the association between 25-OHD and surgical outcomes in patients undergoing ABR. METHODS: We performed retrospective review of all patients who underwent ABR with deep inferior epigastric artery perforator (DIEP) flap(s) at a large academic institution. Patients with 25-OHD and/or albumin levels measured within 3 and 6 months of reconstruction were included. Patients were further grouped on 25-OHD level class based on standard National Institute of Health guidelines, with 25-OHD less than 20 ng/mL denoting insufficiency. Variables of interest included patient demographics, comorbidities, perioperative 25-OHD levels, and postoperative surgical and medical complications. Major post-operative complications were defined as complications requiring urgent return to the operating room during index admission. Minor post-operative complications at the donor and recipient sites included surgical site infection, seroma, non-operative hematoma, dehiscence/delayed wound healing, fat necrosis, and mastectomy flap necrosis. All patients had a minimum of 6 months of follow-up. Standard statistical analysis was performed with t-test and Fisher’s exact tests, with significance set to p < 0.05. RESULTS: Between 2015-2023, 591 patients underwent ABR with 984 DIEP flaps. 25-OHD levels within 3 months of reconstruction were available for 147 patients and 25-OHD levels within 6 months of reconstruction were available for 201 patients. Patients who experienced donor site seromas had lower 25-OHD levels within 3 months of reconstruction when compared to patients who did not (22 ± 8 ng/mL vs 36 ± 17 ng/mL, respectively, p=0.01). Patients who experienced donor site dehiscence/delayed wound healing also had lower 25-OHD levels within 3 months of reconstruction when compared to patients who did not (30 ± 11 ng/mL vs 37 ± 18 ng/mL, respectively, p=0.04). Patients who experienced donor surgical site infections had lower 25-OHD levels within 6 months of reconstruction when compared to patients who did not (24 ± 9 ng/mL vs 36 ± 17 ng/mL, respectively, p=0.05). 25-OHD insufficiency was found to be significantly associated with donor site seromas (OR = 5.5, p=0.03). CONCLUSIONS: Lower levels of 25-OHD within the perioperative period of ABR were found to be associated with donor site seromas, surgical site infections, and dehiscence/delayed wound healing. Enhanced understanding of perioperative 25-OHD levels can help inform clinical decisions and present opportunities for improving surgical outcomes in ABR