Association between body mass index and outcomes after autologous breast reconstruction: a nationwide inpatient database study in Japan

Abstract

BackgroundAlthough autologous reconstruction following breast cancer surgery is common, little is known about the association between preoperative body mass index (BMI) and short-term surgical outcomes. This study investigated the association between BMI and short-term surgical outcomes in autologous breast reconstruction using a nationwide Japanese inpatient database. MethodsWe retrospectively identi ed female patients with breast cancer who underwent breast reconstruction using a pedicled ap or free ap from July 2010 to March 2020. Multivariable regression analyses and restricted cubic spline analyses were conducted to investigate the associations between BMI and shortterm outcomes with adjustment for demographic and clinical backgrounds. ResultsOf the 13,734 eligible patients, 7.1% and 22.2% had a BMI of < 18.5 kg/m 2 and > 25 kg/m 2 , respectively. Compared with BMI of 18.5-21.9 kg/m 2 , overweight (25.0-29.9 kg/m 2 ) and obese (≥ 30.0 kg/m 2 ) were signi cantly associated with higher occurrences of takebacks (odds ratio, 1.74 [95% con dence interval, 1.28-2.38] and 2. 89 [1.88-4.43], respectively) and overall complications (1.37 [1.20-1.57] and 1 .77 [1.42-2.20], respectively). In the restricted cubic spline analyses, BMI showed J-shaped associations with takebacks, overall complications, local complications, and wound dehiscence. BMI also demonstrated linear associations with postoperative surgical site infection, duration of anesthesia, duration of drainage, length of stay, and hospitalization costs. ConclusionIn autologous breast reconstruction following breast cancer surgery, a higher BMI was associated with takebacks, morbidity, a longer hospital stay, and higher total costs, whereas a lower BMI was associated with fewer surgical site infections, a shorter hospital stay, and lower total costs.