Given the grave consequences of venous thromboembolic (VTE) events, we examined the impact of breast reconstruction on VTE incidence in patients undergoing breast operations and, secondarily, assess the risk factors associated with VTE.

Patients undergoing breast operations were identified in the 2007 to 2011 American College of Surgeons NSQIP database. The patients were divided into the following treatment categories: lumpectomy, mastectomy, mastectomy with reconstruction, and reconstruction. Missing data were imputed and propensity score weighting was used to balance confounders in each group. Venous thromboembolism incidence was compared across the groups and risk factors for VTE were analyzed using stepwise multivariate logistic regression.

Overall, 68,285 patients were identified. The global incidence of VTE was 0.27%. The incidence of VTE was highest in the reconstruction and mastectomy with reconstruction groups (0.41% and 0.52% compared with 0.13% in the lumpectomy and 0.29% in the mastectomy groups; p < 0.0001). Independent risk factors for VTE included operation in the 30 days preceding breast surgery (0.56% vs 0.26% for none; p = 0.002), higher BMI (p < 0.0001), increased operative time (p < 0.0001), increased length of hospital stay (p < 0.0001), and oddly, nonsmoking status (0.29% vs 0.14% for smokers; p = 0.012).

Breast reconstruction, higher BMI, increased operative time, operation within 30 days preceding breast surgery, and nonsmoking status are independent risk factors for VTE. The association of lower VTE rates with smoking is counterintuitive and might represent more aggressive VTE prophylaxis in this patient population. Additional investigation is warranted to understand this relationship.