[Double-blind study for the prevention of postoperative thrombosis]

In a double-blind study a randomized group of 96 patients with abdominal operations received a placebo, dipyridamol/acetylsalicylic acid or ASA alone. Thrombi were verified by the 125-I-fibrinogen test. In 38% of the placebo group deep venous thrombosis (DVT) was found, while only 10% of the dipyridamol/ASA group (P less than 0,05) and 28% of the ASA treated patients (not significant) showed radioactive thrombi. DVT were localized in 83.8% in the calf region. 48.6% of increasend activities were registered up to the end of the first postoperative day, 78.3% up to the third day. The results emphasize the importance of a general antithrombotic prophylaxis. Dipyridamol/ASA seems to be efficient in this regard for abdominal procedures.