Venous thrombosis after abdominal surgery. A comparison between subcutaneous heparin and antithrombotic stockings, or both

In an open controlled study, 248 consecutive patients (age more than 40 yrs) admitted for major abdominal surgery were randomized to one of three prophylactic antithrombotic treatments. Eighty-five patients received subcutaneous heparin, 74 patients had graduated compression stockings to the knee (TED stockings), and 89 patients had both subcutaneous heparin and stockings. Treatment began on the evening before operation and continued to complete mobilization, or for not less than five days postoperatively. On the fourth or fifth postoperative day, the patients underwent a 99mTc-plasmin test of the lower limbs as a test for deep vein thrombosis. There were 29.7% positive tests in the stocking group, 29.4% in the group with heparin prophylaxis, and 25.8% in the combined group. Differences between treatments were not statistically significant.