Intraarterial Thrombolysis: Pros

Abstract

Under favorable conditions the body itself is able to dissolve even extensive arterial thrombi spontaneously and completely. It does this with the help of the tissue activator (t-PA) which is produced from endothelial cells and acts physiologically at the site of its formation, which means it acts locally and not systemically. It can achieve this in 10%–15% of embolic occlusions in healthy arteries with a minimal amount of t-PA which never produces any systemic effect. In thrombotic occlusions in arteries with arteriosclerotic changes, however, spontaneous lysis occurs very rarely, probably because the ability to release t-PA is reduced. We have been able to assist this lysis for over 25 years by using streptokinase (SK) or urokinase (UK). Until 8 years ago these activators of fibrinolysis were administered almost exclusively systemically. Depending on the size of the thrombus, a standard dosage of 2.5 million units of these substances has to be administered daily for several days if necessary. Using an ultrahigh dosage of 9 million units over 6 h, the same dose is recommended the next day if necessary. The results have been encouraging where the indications were favorable but the risk of bleeding or provoking systemic embolism could not be reliably estimated even by paying careful attention to the many contraindications, so that this therapy could not be employed generally [7].