Impact of skeletal muscle mass volume on surgical site infection in free flap reconstruction for oral cancer.

Abstract

Sarcopenia is a disease in which skeletal muscle mass (SMM) and function are progressively lost. Here, we investigate surgical site infection (SSI) as a function of SMM in patients who underwent free flap reconstruction for a defect caused by oral cancer resection. A nonrandomized, retrospective group of 122 patients treated with free flap reconstruction after oral cancer resection was enrolled in the study. All subjects also underwent preoperative abdominal-lumbar computed tomography (CT). Cross-sectional areas (cm² ) of skeletal muscles in the L3 region were measured by manual outline on CT images. The obtained areas were normalized for height (cm² /m² ), and the resulting value is referred to as the skeletal muscle index (SMI). Recipient site SSI occurred in 30 patients (24.6%). Underweight status (body mass index [BMI] < 18.5 kg/m² ), anemia and lower SMI were significantly related to recipient site SSI in univariate analysis (p < . 05). In multiple logistic regression analysis, lower SMI was an independent significant risk factor for recipient site SSI (p = .015, adjusted odds ratio = 1.41 per 5 cm² /m² decrease). These findings suggest that a decrease in SMM might have more impact than a decrease in BMI on SSI in free flap reconstruction after resection of oral cancer.