[The role of subarachnoid periarterial acidosis and platelets aggregation in symptomatic cerebral vasospasm: an experimental study].

The possible role of subarachnoid periarterial acidosis and platelets aggregation in symptomatic cerebral vasospasm after subarachnoid hemorrhage was studied in animal experiments. Canine or feline subarachnoid space was irrigated with low pH (6.49 +/- 0.06, N = 10) physiological saline or with high pH (8.0) Hartmann solutions after subarachnoid hemorrhage was induced by cisternal autologous blood injection. Angiographical changes of the basilar artery, neurological conditions, platelet functions in blood taken from the superior sagittal sinus, and histological findings particularly those concerning intraarterial blood were examined comparatively before and after the irrigation and, in relation to different irrigation fluids. No significant differences were observed in the angiographical changes of the basilar artery either before or after irrigation. Neither did different irrigation fluids have an effect on these changes. As for the neurological conditions, however, deterioration after irrigation was more frequent and evident in the group treated with physiological saline than in the group treated with Hartmann solution. Platelet function in the blood taken from the superior sagittal sinus also tended to be more activated in the group treated with physiological saline. In animals treated with physiological saline, histopathological examination of the autopsied brain revealed marked intraluminal platelets aggregation, particularly in the basilar artery and its branches where subarachnoid clots were mostly evident. An affirmative result for the preamble was obtained in this study.