[Fibrinolytic therapy of deep vein thrombosis]

The most important complications of deep vein thrombosis are pulmonary embolism and postthrombotic syndrome. While the medicine of lethal pulmonary embolism is reduced to less than 2% by conventional anticoagulation, fibrinolytic therapy aims at a reduction of the greater than 50% incidence of postthrombotic syndrome. The optimal therapeutic regimen concerning risks and effect has not been established yet.

A review of 26 studies involving ultrahigh-dose streptokinase (UHSK), urokinase (UK), and tissue-type plasminogen activator (rt-PA) shows the highest success rate for UHSK (45% complete and 40% parital patency), whereas there are lower rates for UK (25% and 40%) and low-dose locoregionally applied rt-PA (22% and 44%). The studies were not directly comparative, however. Published data concerning complications range from 1.7% mortality for UHSK to 0.9% for UK and 0.0% for rt-PA. Success criteria, however, are varying and not well defined. The influence of fibrinolytic therapy on the incidence of postthrombotic syndrome has not been established prospectively, but a reduction by 40 to 50% can be assumed. Calf vein thromboses are not indication for lytic therapy. In patients with iliacal vein thromboses there is an increased risk of pulmonary embolism using UHSK.

UHSK can be regarded the standard concerning success rate in deep vein thromboses. DATA involving locoregional therapy with rt-PA are inconsistent and worse, but bleeding complications might be less frequent. Large prospective studies evaluating the impact on incidence and severity of the postthrombotic syndromes, which involve a controlled application of compression therapy are needed.