Sarcopenia is characterized by the loss of skeletal muscle mass and power. Preoperative sarcopenia may be associated with an increased risk of postoperative complications after autologous free-flap breast reconstruction surgery; however, this relationship is controversial.

This study aimed to determine whether preoperative sarcopenia is associated with a high complication rate in patients undergoing autologous free-flap breast reconstruction.

Patients who underwent autologous free-flap breast reconstruction at our hospital between 2019 and 2021 were included in the study. Data on significant complications requiring surgical intervention were retrospectively collected from the medical records. Sarcopenia was defined as having a skeletal muscle index value <41 cm²/m². The skeletal muscle index was calculated by dividing the sum of the psoas and iliopsoas muscle areas at the level of the third lumbar vertebra by the patient’s height in meters squared. The relationship between preoperative sarcopenia and postoperative complications was investigated using an inverse probability of treatment weighting (IPTW) analysis.

Among the 203 participants, 90 (44.33%) had preoperative sarcopenia. The general patient characteristics were similar between the sarcopenia and non-sarcopenia groups after IPTW adjustment. Sarcopenia did not significantly increase the risk of flap failure or emergency surgery related to breast reconstruction before IPTW adjustment. However, after IPTW adjustment, the rates of recipient site infection and hematoma were significantly higher in participants with sarcopenia than in those without sarcopenia (p < 0.001 and p = 0.014, respectively).

Preoperative sarcopenia may influence certain complications of autologous free-flap breast reconstruction surgery.