Comparing Blood Loss in Immediate and Delayed Autologous Breast Reconstruction.

Blood loss is a critical component of all surgical procedures. Excess blood loss may require a blood transfusion and increase the risk of complications after autologous breast reconstruction.Retrospective cohort of 264 consecutive autologous breast reconstruction patients between July 2017 and June 2022. Patients were stratified by reconstruction timing and bilateral versus unilateral reconstruction. Postoperative hemoglobin reduction and transfusion incidence were the primary outcomes of interest.Average preoperative hemoglobin (12.6 g/dL) was equivalent among all groups. Comparing bilateral immediate (n = 77) and delayed (n = 50) patients, immediate reconstructions had greater postoperative hemoglobin losses (-3.26 g/dL vs. -1.98 g/dL, p < 0.01) and higher transfusion rates (14% vs. 2.0%, p = 0.02). Comparing unilateral immediate (n = 99) and delayed (n = 38) patients, immediate reconstructions had greater hemoglobin losses (-2.60 g/dL vs. -1.41 g/dL, p < 0.0001) and higher transfusion rates (12.1% vs. 0.0%, p = 0.03). Using regression analysis, controlling for confounding variables and intraoperative resuscitation risk factors for blood transfusion requirement, were postmastectomy radiation therapy requirement (odds ratio [OR]: 10.3, p < 0.01) and vascular disease (OR: 14.5, p = 0.02). Unilateral reconstruction was protective from requiring transfusion (OR: 0.20, p = 0.03). Increasing BMI was protective, and with each increasing unit of BMI, transfusion requirement incidence decreased by 12.3% (p = 0.04). Transfusion was not associated with flap thrombosis or flap loss.Compared to immediate autologous breast reconstruction, a staged approach to both unilateral and bilateral patients can help minimize the risk of transfusion requirement. These factors, as well as additional modifiable and nonmodifiable risk factors, should be considered when determining the timing of autologous breast reconstruction for a patient.