An analysis of underweight status on 30- day outcomes after breast reconstruction

Aim: To examine the impact of underweight body mass index (BMI) values on breast reconstruction outcomes. Methods: The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was retrospectively reviewed for all patients who underwent breast reconstruction between 2006 and 2011. Patients were first stratified by breast reconstruction modality into prosthetic or autologous cohorts, and second by BMI values into underweight (BMI < 18.5), normal to overweight (reference, BMI 18.5-29.99), moderate obesity (BMI 30-34.99), severe obesity (BMI 35-39.99), and morbid obesity cohorts. Multivariate logistic regression models were used to determine independent predictors of complications. Results: With regard to prosthetic breast reconstruction patients, obese patients demonstrated increased rates of surgical complications, while underweight patients did not have any differences on multivariable analysis. With respect to autologous reconstruction, risk-adjusted multivariate regression models showed a dose dependent response between obesity and risk for surgical complications and reoperation, but not for underweight patients. Conclusion: On multivariable analysis of over 4,600 patients, there were no significant differences in the rates of adverse events between underweight patients (BMI < 18.5) and their reference-weight counterparts, in spite of a significant increase in surgical and medical complication rates in underweight patients on univariate analysis.