Fibrinolysis and aspiration of experimental intracerebral hematoma reducesthe volume of ischemic brain in rats

The hypothesis was tested in rats that brain ischemia by an intracerebral h ematoma can be ameliorated by fibrinolysis and aspiration of the hematoma. Intraparenchymal blood clots were generated by the injection of 50 mu l of autologous blood into the right caudate nucleus in two portions seven minut es apart Thirty or 120 min later 12 mu l recombinant tissue plasminogen act ivator (rtPA) or 0.9% NaCl were injected and after 30 min the resolved hema toma was aspirated. Six hours later cerebral blood flow (CBF) was determine d by C-14-iodoantipyrine autoradiography. Tissue volumes of CBF < 10ml 100g (-1) min(-1) and CBF < 30ml g(-1) min(-1) were determined. Clot and lesion volume were quantified histologically from serial sections stained for succ inate-dehydrogenase (SDH) activity. In rtPA-treated rats the major part of the hematoma could be evacuated 30 min as well as 120 min after production of the clot The volume of ischemic brain (CBF < 10) was significantly reduc ed (p < 0.05) in the rtPA group compared to saline-treated and control grou ps irrespective of the time of treatment In contrast, no difference was fou nd between the control group and the experimental groups when the volumes o f brain tissue surrounding the lesion were compared which had values of CBF < 30ml 100 g(-1) min(-1). In a rat model of intracerebral hemorrhage, trea tment by local fibrinolysis followed by aspiration of the hematoma is effec tive in reducing the volume of ischemic brain tissue and of the remaining c lot volume.