Thrombolysis in acute stroke

The use of fibrinolytic agents in acute ischemic stroke has received increasing attention due to the completion of several prospective studies examining the efficacy and safety of these drugs in this clinical setting. Experience with plasminogen activators indicates that recanalization of carotid and vertebrobasilar territory occlusion is feasible within 4-6 hours of symptom onset. The optimal plasminogen activator, its dose-rate and delivery system, however, is not known. The phase III trial of the European Cooperative Acute Stroke Study (ECASS) suggests potential modest benefit in outcome, although recombinant tissue plasminogen activator (rt-PA) had an increased risk of hemorrhage attributable to those patients with early CT-scan signs of ischemia. Complete cervical internal carotid artery occlusions by in situ thrombosis appear more resistant to thrombolysis than occlusions of the stem and major branches of the middle cerebral artery. The issue of hemorrhagic transformation is unsettled. It seams to be increased by delayed intervention on the one hand, but it is not different from that observed in placebo patients in phase I/II series.