[Intravenous thrombolytic therapy and its unresolved problems in Japan]

Since October 2005, following government approval for tPA use in acute ischemic stroke, over 5,000 patients have been given intravenous thrombolytic therapy in Japan. According to the newest but incomplete report on post-marketing investigations, whereas the rate of hemorrhagic complications remains the same, the proportion of good outcomes is slightly lower than that in Europe. This may reflect the higher inclusion rate of cardioembolic stroke and severe stroke patients in Japan. Many important, unresolved problems still exist concerning tPA therapy even in Japan. In particular, improvement of the emergency medical systems which transport acute stroke patients for thrombolysis to the primary stroke center appropriately and rapidly, and the establishment of in-hospital systems for tPA therapy including extensive co-medical staff and neuroradiological equipment, have priority. Moreover, high expectations are held for new stroke MR techniques including "diffusion-perfusion mismatch", combined additional antithrombotic drugs or intra-arterial cathetherization maneuvers, and ultrasound examinations with contrast media, to achieve a more favorable outcome with this therapy.