Prevention of postoperative thromboembolism by various treatments. Controlled clinical trial in 632 patients using 125I-fibrinogen uptake test and lung perfusion scans in patients with deep venous thrombosis.

In 632 patients efficacy of dihydroergotamine (DHE) in preventing postoperative deep venous thrombosis (DVT) and pulmonary embolism (PE) was tested vs. low-dose heparin (LDH) by means of the 125I-fibrinogen uptake test (RFUT). The incidence rate of DVT dropped from 36% (untreated group) to 17% after LDH, to 13% after DHE, and to 9% after simultaneous prophylaxis with both drugs. In patients with lower risk operations lasting not longer than 2 hs complete prevention of DVT was achieved by combined use of LDH and DHE. PE incidence in repeated lung perfusion scans of patients with positive RFUT was reduced to 4.3-2.6% (treated groups) in comparison to an incidence of 50% in the control group. This means the decrease of PE was overproportional in all treatment groups in comparison to the decrease of DVT incidence. The combined use of LDH and DHE may be considered as the best prophylactic regimen available for lowering postoperative DVT and PE.