“Body composition as an indicator of the risk of complications after microvascular DIEP breast reconstruction”

BACKGROUND: The deep inferior epigastric perforator (DIEP) flap is a common breast reconstruction technique. As a microvascular procedure, it carries a risk of complications requiring careful patient selection. While high body mass index (BMI) is a recognized risk factor for complications, the role of muscle mass and more detailed body composition remains unclear. This study aimed to investigate the impact of low muscle mass and high BMI on complications in patients undergoing DIEP breast reconstruction. METHODS: We retrospectively studied patients who underwent DIEP breast reconstruction at our tertiary center during the years 20182021. Preoperative CT scans were used to calculate skeletal muscle index (SMI). Patients were classified into four phenotype categories based on SMI (cut-off: 38.5 cm 2/m 2) and BMI (cut-off: 25 kg/m 2). Complication rates were evaluated and compared between phenotypes. RESULTS: Altogether 204 patients were included, of which 29 (14.2%) met the criteria for sarcopenic overweight (SMI < 38.5 cm 2/m 2 & BMI > 25 kg/m 2). Complications occurred in 37 (18.1%) patients. Sarcopenic overweight associated with higher rates of early flap (p = 0.009) and overall (p = 0.034) complications compared to other phenotypes. In multivariable analysis, sarcopenic overweight was the only significant factor associated with overall complications (OR 8.66, 95% CI: 1.68-44.62, p = 0.010). Neither sarcopenia nor overweight alone were independent risk factors for complications. CONCLUSIONS: In this study, sarcopenic overweight was associated with an eightfold increased risk of complications following DIEP breast reconstruction. Body composition, rather than mere BMI, should be considered when evaluating patients for breast reconstruction.