The risk of post-operative bleeding is the chief concern expressed by plastic surgeons who do not use pharmacologic prophylaxis against venous thromboembolism (VTE). The Plastic Surgery Foundation-funded Venous Thromboembolism Prevention Study (VTEPS) examined whether receipt of post-operative enoxaparin prophylaxis changed rates of 60-day re-operative hematoma.
In 2009, VTEPS Network sites uniformly adopted a “best practice” clinical protocol to provide post-operative enoxaparin prophylaxis to adult plastic surgery patients at risk for peri-operative VTE. VTEPS historic control patients (2006–2008) received no chemoprophylaxis for 60 days after surgery. Retrospective chart review identified demographic and surgery-specific risk factors that potentially contributed to bleeding risk. The primary study outcome was 60-day re-operative hematoma. Stratified analyses examined re-operative hematoma in the overall population and among high-risk patients. Multivariable logistic regression controlled for identified confounders.
Complete data were available for 3,681 patients (2,114 controls and 1,567 enoxaparin patients). Overall, post-operative enoxaparin did not change the rate of re-operative hematoma when compared to controls (3.38% vs. 2.65%, p=0.169). Similar results were seen in subgroup analyses for breast reconstruction (5.25% vs. 4.21%, p=0.737), breast reduction (7.04% vs. 8.29%, p=0.194), or non-breast plastic surgery (2.20% vs. 1.46%, p=0.465). In the regression model, independent predictors of re-operative hematoma included breast surgery, microsurgical procedure, and post-bariatric body contouring. Receipt of post-operative enoxaparin was not an independent predictor (OR 1.16, 95% CI 0.77–1.76).
Post-operative enoxaparin does not produce a clinically relevant or statistically significant increase in observed rates of re-operative hematoma. Independent predictors for re-operative hematoma include breast surgery, post-bariatric body contouring, and microsurgical procedure.
Level of Evidence
III (retrospective cohort study)