Association between body mass index and adverse surgical outcomes of implant-based breast reconstruction: a prospective cohort study of 5,545 breast reconstructions

Abstract

Background: Breast cancer is the highest incident cancer amongst women globally, with the exception of skin cancer. Approximately 15% of women globally are overweight, equating to an economic burden of $11 billion per year. To date, few studies have focused on the effects of obesity specifically in patients undergoing implant-based breast reconstruction for breast cancer. Methods: We reviewed the 2007 to 2012 American College of Surgeons National Surgical Quality Improvement Program (ACS‐NSQIP) databases identifying encounters for implant‐based reconstruction (immediate, delayed, and tissue expander), as a prospective cohort study. Patients were classified and compared based on World Health Organisation (WHO) obesity criteria: body mass index (BMI) ≤25 kg/m2 —‘not overweight’, BMI 25 to ≤30 kg/m2—‘overweight’, BMI 30 to ≤40 kg/m2—‘obese to severely obese’ and BMI >40 kg/m2—‘morbidly obese’. Results: During the study period 5,545 implant‐based breast reconstructions were performed post mastectomy. Morbidly obese patients had a markedly greater likelihood of wound complications [odds ratio (OR) 2.47, 95% confidence interval (CI): 1.20–4.38, P=0.008] compared to their non‐overweight counterparts. Morbidly obese patients also had 2.91 (95% CI: 1.21–5.94) times the likelihood of wound infection (P=0.009) and 8.54 (95% CI: 2.80–21.41) times the likelihood of wound dehiscence (P<0.001) compared with non‐overweight patients. Those that were obese to severely obese also had an increased likelihood of wound infection compared to non‐obese patients (OR 1.64, 95% CI: 1.0–2.7, P=0.048). Conclusions: This study characterized the effect of progressive obesity using a prospective, multicentre dataset. Increasing obesity is associated with increased perioperative morbidity. The negative consequences of obesity on operative outcomes can be used to counsel patients on the importance optimizing preoperative BMI, particularly considering lifestyle factors in the context of oncological management.