Effect of BMI on modality-specific outcomes in immediate breast reconstruction (IBR)--a propensity-matched analysis using the 2005-2011 ACS-NSQIP datasets.

Obesity is a prevalent, multisystem disease emerging as a pervasive risk factor for surgical morbidity. This study aims to perform a modality-specific risk assessment of IBR outcomes using the World Health Organisation (WHO) obesity stratification. This study reviewed the 2005-2011 ACS-NSQIP databases, identifying encounters for either implant or autologous-based reconstruction. Patients were classified and compared based on WHO classification criteria for BMI, and complications were divided into any surgical, major surgical, wound, and medical complications. A total of 18,194 patients underwent IBR. Patients were Caucasian (76.1%) and middle aged (45-64 years) (62.4%), with an average BMI of 27.1 ± 6.3 kg/m(2). A total of 14,585 patients underwent implant-based reconstructions. A multivariate logistic regression analysis of patient characteristics associated with autologous reconstruction revealed several independently associated factors, summarised in Table III. Our analysis revealed that reconstructive modality was not statistically associated with surgical morbidity in class I obese patients (OR = 1.21, p = 0.328), but was independently associated with progressively greater odds of surgical complications in class II (OR = 1.92, CI = 1.04-3.55, p = 0.036) and class III (OR = 2.71, CI = 1.14-6.46, p = 0.024). This study characterises the modality-specific risk of surgical and medical morbidity in patients undergoing IBR across BMI-stratified cohorts. The risk-adjusted models of early morbidity in IBR reveal a significant BMI-specific risk divergence that occurs at class II obesity cohorts and above. These data serve as a useful benchmark for early, modality-specific morbidity across BMI-stratified cohorts and can be used to better tailor preoperative risk counselling in patients considering autologous reconstructions.