[Treatment of pulmonary embolism. Current status and future prospects]

Although still severe, the prognosis of pulmonary embolism has recently improved due to considerable progress in the therapeutic field. This paper concerns the various therapeutic tools, both pharmacologic and surgical, which are already available or under evaluation. Despite the introduction of thrombolytic drugs, heparin remains an indispensable drug. The rationale for its use comes from the need of preventing further clot formation, while endogenous fibrinolysis or thrombolytic drugs are dissolving the already existing clots. Thrombolytic drugs, such as streptokinase, urokinase or rt-PA, have changed the therapeutic strategy of pulmonary embolism, due to their ability to accelerate the normal fibrinolytic mechanisms and to facilitate pulmonary reperfusion. This often allows an early disappearance of symptoms and a reduced incidence of invalidating complications involving the respiratory function. rt-PA seems to be most effective and fast in inducing reperfusion (angiographic signs of clot dissolution are obtained in 82% of the patients within 2 hours). The administration of rt-PA by intravenous bolus has recently been proposed, which would induce an even faster thrombolysis and fewer hemorrhagic complications. The role of surgical therapy has declined after the diffusion of thrombolytic drugs, being reserved only for the most serious cases. When anticoagulation is counter-indicated or not effective, the prevention of embolic relapses can be achieved by percutaneous insertion of caval filters of different types. Some new catheters provided with rotating metallic tips, which allow the mechanical fragmentation of the emboli, are presently under evaluation. Although some improvements are needed, this technique is expected to become soon of general use, especially in cases in which thrombolytic therapy is counter-indicated.