Akute zerebrale Ischämie – Neue Studien und Behandlungsstrategien

Die systemische Thrombolyse ist derzeit die einzige nachgewiesen effektive und zugelassene Akutbehandlung des Schlaganfalls in einem Zeitfenster bis 4,5 Stunden nach Symptombeginn. Zunehmend wird die Kernspintomografie zur Therapieentscheidung beim akuten Schlaganfall, vor allem bei einem Zeitfenster > 4,5 Stunden und somit außerhalb der Zulassungskriterien für die Thrombolyse eingesetzt, wobei der Nachweis eines therapeutischen Effekts in größeren Studien noch aussteht. Die erste randomisierte kontrollierte Studie, die eine intravenöse Thrombolyse mit einer kombinierten intravenösen und intraarteriellen Therapie („Bridging-Konzept“) verglich, wurde kürzlich vorzeitig abgebrochen, weil man keinen statistisch signifikanten Unterschied zwischen beiden Behandlungsarmen erwartete. Beim akuten symptomatischen Verschluss der A. basilaris ermutigen Ergebnisse einer multizentrischen Datenbankanalyse dazu, zunächst stets eine intravenöse Therapie durchzuführen und in Einzelfällen eine interventionelle Anschlussbehandlung zu ermöglichen. Neuere Erkenntnisse deuten darauf hin, dass der Nutzen einer systemischen Thrombolysetherapie nicht nur in der alleinigen Rekanalisation einer verschlossenen größeren Hirnarterie besteht, sondern auch in der Verbesserung des Kollateralflusses und der arteriolären Mikrozirkulation in der Penumbra liegt.

Systemic thrombolysis is currently the only efficacious and approved acute therapy of patients presenting with ischemic stroke within 4.5 hours after onset of symptoms. Clinical experience suggests the possibility of selecting patients likely to benefit from thrombolysis outside of the 4.5 hours time window by using modern MR imaging based selection criteria. However, the therapeutic effect of this approach is yet to be proven by large trials. The first randomized controlled study of a combined intravenous and intra-arterial thrombolysis ('bridging technique') versus intravenous thrombolysis alone was recently stopped prematurely due to lack of therapeutic difference between the two treatment arms. Results of a multicenter database analysis encourage clinicians to treat patients who have acute symptomatic basilar artery occlusion with intravenous thrombolysis as a first-line therapy. Current research suggests a benefit of systemic thrombolysis not only by recanalising an occluded large cerebral artery but also by the enhancement of intracranial collaterals, and improvement of the microcirculation of arterioles.

Key words

Stroke - thrombolysis - recanalisation - reperfusion - bridging technique - microcirculation - collateral blood supply

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