Abstract 125: The Effect of Timing of Perioperative Anticoagulation on the Outcome of Microsurgical Breast Reconstruction

PURPOSE: Venous thromboembolism (VTE) risk is inherently high in autologous breast reconstruction patients, due to procedure length, prolonged immobility, and patient comorbidities. Recent guidelines favor early administration of low-molecular weight heparin (LMWH) for VTE prophylaxis. The purpose of this study was to compare immediate and later LMWH administration in terms of VTE incidence and flap outcomes. METHODS: A retrospective review was performed of all microsurgical breast reconstruction patients between 2011–2017. Patient care followed an established postoperative protocol, with the exception of postoperative LMWH administration, given either immediately (“Immediate”), or the following morning (“Later”), based on surgeon preference. Demographic and outcome data were collected and analyzed via Student’s t-test (p<0.05). RESULTS: 290 free flaps were performed in 186 patients. 93 received LMWH within 8 hours, and 93 received LMWH 8–24 hours postoperatively. There were no significant differences amongst the groups in terms of demographics and outcomes. However, there were twice as many patients with VTE in the “Later” group, and three times as many with hematomas. CONCLUSION: In microsurgical breast reconstruction, there is an ongoing discussion regarding the optimal timing of chemical VTE prophylaxis, due to concerns about bleeding risk. Our results suggest that early postoperative LMWH administration can decrease VTE risk without increasing clinically significant bleeding. This information can help further refine existing evidence-based guidelines and improve surgical outcomes and patient safety.