Venous thromboembolism following microsurgical breast reconstruction: an objective analysis in 225 consecutive patients using low-molecular-weight heparin prophylaxis.

BACKGROUND Free flap breast reconstruction involves major risk factors for postsurgical venous thromboembolism. The main study objectives were (1) to estimate objectively the incidence of symptomatic and asymptomatic lower extremity deep vein thrombosis in patients who received postoperative thromboprophylaxis after free flap breast reconstruction, (2) to evaluate the safety of low-molecular-weight heparin postoperatively, and (3) to assess the incidence of symptomatic pulmonary embolism or sudden death. METHODS A cohort study of 225 consecutive patients who underwent abdominally based free flap breast reconstruction at a single cancer center was conducted. The postoperative thromboprophylaxis regimen was based on the American College of Chest Physicians guidelines. A study group of 118 patients systematically underwent bilateral lower extremity duplex ultrasound before hospital discharge to assess objectively the status of the lower extremity deep venous system. A retrospective cohort of 107 women who were not systematically screened for deep vein thrombosis was used for comparison. RESULTS The incidence of postoperative deep vein thrombosis confirmed by duplex ultrasound was 3.4 percent in the study group, all events being clinically silent. Bleeding complications in the entire patient sample were estimated at 5.3 percent. Partial flap loss and total flap loss rates were 2.7 and 1.9 percent, respectively. No venous thromboembolism event was diagnosed in the control group. CONCLUSIONS This report shows that the objective incidence of deep vein thrombosis was 3.4 percent within 5 postoperative days in this patient population. The authors' findings support the use of triple thromboprophylaxis and demonstrate that low-molecular-weight heparin is a safe and effective method for prevention of venous thromboembolism in this population.