New developments in the thrombolytic therapy of venous thrombosis

Summary

 Thrombolysis in deep venous thrombosis is indicated in acute thrombosis of the legs, because in most cases it is due to no or to minimal collateral flow with bad prognosis. Thrombolysis should not be used regularly in isolated thrombosis of the veins of the lower legs and in subclavia vein thrombosis. The aims in therapy of deep venous thrombosis are (1) reduction of fatal pulmonary embolism, (2) avoidance of progression and recurrence, and (3) avoidance of a postthrombotic syndrome. In contrast to heparin alone, thrombolysis has the advantage of high recanalization rates. With clinically used dosage regimens of streptokinase complete and partial recanalization rates are in the range of 60–70% of primary occluded veins. According to pilotal and dose-finding studies, the results with rt-PA are in the same range. In a different approach, the thrombolytic substances are delivered in a loco-regional type via a vein of the foot. There is some evidence from pilotal clinical trials that the comparable response rates are obtainable as with streptokinase in ultrahigh dosage combined with a lower incidence of bleeding complications and pulmonary embolism. Furthermore there is a need for prospective, randomized trials comparing therapy with rt-PA and heparins, especially low molecular heparin.