Low-molecular-weight heparins and Daflon for prevention of postoperative thromboembolism.

The efficacy of low-molecular-weight heparins (LMWH) alone versus a combination of Daflon 500 mg with LMWH in preventing postoperative symptomatic thromboembolism was investigated. A total of 1372 patients aged 40 years or older undergoing major abdominal, pelvic, or abdominal wall surgery were randomized into four groups. Group A (n = 591) received enoxoparin 20 mg or fraxiparin 0.3 ml. Group B (n = 595) received the regimens of group A plus Daflon 500 mg. Group C (n = 93) received enoxoparin 40 mg or fraxiparin 0.6 ml. Group D (n = 93) received the regimens of group C plus Daflon 500 mg. Each LMWH was given subcutaneously once a day during the hospitalization and continued in groups C and D for 15 days after discharge (high risk patients). Daflon 500 mg was given as two tablets every 8 hours during the day before surgery, two tablets 6 hours before surgery, and two tablets once a day on postoperative days 4 to 15. Daily clinical examination was performed; and phlebography or perfusion lung scanning (or both) were used in symptomatic patients to confirm deep vein thrombosis (DVT) or pulmonary embolism (PE). The wound was examined on a daily basis for hematomas. The diagnosis of PE was established in two patients of group A and in three patients of group C; symptomatic DVT was established in one patient in group A and three patients of group C. Neither DVT nor PE were established in Daflon 500 mg groups. These data suggest that the combination of Daflon 500 mg and LMWH is more effective than LMWH alone for preventing symptomatic thromboembolism.