[Prophylaxis of postoperative thromboembolism. Randomized prospective study].

The difference between a non fractioned heparin (Liquemine) and another of low molecular weight (Fraxiparine) was compared through: hemostasis difficulties, during and after surgery; the use of transfusions; clinical signs of inferior limb vein thrombosis or pulmonary emboli; laboratory results of blood (hemogramme, biochemistry, coagulation) and urine. The results observed in 500 patients, (250 of each heparin) statistically treated, show that no difference was found between the two groups of patients, which lead us to conclude that both heparins have the same effect. Low molecular weight has the advantage of being administrated only once a day.