Terapia trombolitica

Thrombolytic therapy for ischemic stroke—A review. Part II—Intra-arterial thrombolysis, vertebrobasilar stroke, phase IV trials, and stroke imaging
Peter D. Schellinger, MD; Jochen B. Fiebach, MD; Alexander Mohr, MD; Peter A. Ringleb, MD; Olav Jansen, MD; Werner Hacke, MD, PhD

Objective: Intra-arterial thrombolytic therapy for carotid and vertebrobasilar stroke may result in a more rapid clotlysis and higher recanalization rates than can be achieved with intravenous thrombolysis and thus may warrant the more invasive and timeconsuming therapeutic approach. We present an overview of all hitherto completed trials of intra-arterial thrombolytic therapy for carotid and vertebrobasilar artery stroke including recommendations for therapy and a meta-analysis. Furthermore, new imagingtechniques such as diffusion- and perfusion-weighted magnetic resonance imaging and their impact on patient selection are discussed. Finally, phase IV trials of thrombolysis in general and cost efficacy analyses are presented. Data Sources: We performed an extensive literature search not only to identify the larger and well-known randomized trials but also to identify smaller pilot studies and caseseries. Trials included in this review, among others, are the PROACT I and PROACT II studies and the Cochrane Library report. Conclusion: Intra-arterial thrombolytic therapy of acute M1 and M2 occlusions with 9 mg/2 hrs pro-urokinase significantly

improves outcome if administered within 6 hrs after stroke onset. Seven patients need to be treated to prevent one patient from death or dependence.Vertebrobasilar occlusion has a grim prognosis and intra-arterial thrombolytic therapy to date is the only life-saving therapy that has demonstrated benefit with regard to mortality and outcome, albeit not in a randomized trial. New magnetic resonance imaging techniques may facilitate and improve the selection of patients for thrombolytic therapy. Presently, thrombolytic therapy is still underutilizedbecause of problems with clinical and time criteria, and lack of public and professional education to regard stroke as a treatable emergency. If applied more widely, thrombolytic therapy may result in profound cost savings in health care and reduction of long-term disability of stroke patients. (Crit Care Med 2001; 29:1819 –1825) KEY WORDS: thrombolysis; ischemic stroke; review; intra-arteriallysis; intravenous lysis; vertebrobasilar stroke; diagnostic imaging; diffusion magnetic resonance imaging; perfusion magnetic resonance imaging; computed tomography

troke is the third most common cause of death in the industrialized nations, after myocardial infarction and cancer, and the single most common reason for permanent disability (1). Up to 85% of all strokes are of ischemic origin andmost are the result of blockage of a cerebral artery by a blood clot (2). Occlusion of a brain vessel leads to a critical reduction in cerebral perfusion and, within minutes, to ischemic infarction (see also Part I of this review). Therefore, the underlying rationale for the introduction and application of thrombolytic agents is the lysis of an obliterating thrombus and subsequent reestablishment ofcerebral blood flow by cerebrovascular recanalizaFrom the Departments of Neurology (PDS, PAR, WH) and Neuroradiology (JBF, AM), University of Heidelberg, Heidelberg, Germany; and the Department of Neuroradiology, University of Kiel, Kiel, Germany (OJ). Copyright © 2001 by Lippincott Williams & Wilkins

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tion (3). The delivery of thrombolytic agents locally, at or within the occludingthrombus, has the advantage of providing a higher concentration of the particular thrombolytic agent where it is needed while minimizing the concentration systemically. Hence, local intra-arterial thrombolysis has the potential for greater efficacy with regard to arterial recanalization rates and greater safety with regard to lower risk of hemorrhage. The technique involves performing a cerebral...