A randomized study of a semisynthetic heparin analogue and heparin in prophylaxis of deep vein thrombosis.

The prophylactic effect of a semisynthetic heparin analogue (SSHA) on deep vein thrombosis was investigated in a prospective double-blind multicentre trial. 440 major general surgical and gynaecological patients were randomized to one of three treatment groups: 50 mg SSHA, 37.5 mg SSHA and 5000 units sodium heparin subcutaneously 12-hourly. Deep venous thrombosis (DVT) was diagnosed with the fibrinogen uptake test and verified with phlebography. Bleeding complications and other side-effects were carefully monitored. There were no significant differences between the three treatment groups of patients in age, sex, type of operation or risk factors. A DVT was diagnosed in 16 patients (12 per cent) in the SSHA 50 mg group, in 21 patients (15 per cent) in the SSHA 37.5 mg group and 21 patients (14 per cent) in the heparin-treated group. No significant differences were found in the number of patients who bled unexpectedly in the postoperative period, required transfusion or developed wound haematomas. Blood loss at operation was similar in all three groups. Three pulmonary emboli were diagnosed by pulmonary scintigraphy, one in each group.