Fibrinolytic therapy of deep vein thromboses

Background: The most important complications of deep vein thrombosis are pu lmonary embolism and postthrombotic syndrome. While the incidence of lethal pulmonary embolism is reduced to less than 2% by conventional anticoagulat ion, fibrinolytic therapy aims at a reduction of the greater than 50% incid ence of postthrombotic syndrome. The optimal therapeutic regimen concerning risks and effect has not been established yet. Results: A review of 26 studies involving ultrahigh-dose streptokinase (OHS K), urokinase (UK), and tissue-type plasminogen activator (rt-PA) shows the highest success rate for UHSK (45% complete and 40% partial patency), wher eas 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, how ever. 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 var ying and not well defined. The influence of fibrinolytic therapy on the inc idence of postthrombotic syndrome has not been established prospectively, b ut a reduction by 40 to 50% can be assumed. Calf vein thromboses are no ind ication for lytic therapy. In patients with iliacal vein thromboses there i s an increased risk of pulmonary embolism using UHSK. Conclusions: UHSK can be regarded the standard concerning success rate in d eep vein thromboses. Data involving locoregional therapy with rt-PA are inc onsistent and worse, but bleeding complications might be less frequent. Lar ge prospective studies evaluating the impact on incidence and severity of t he postthrombotic syndroms, which involve a controlled application of compr ession therapy, are needed.