PREVENTIVE EFFECT OF INTRACISTERNAL HEPARIN FOR PROLIFERATIVE ANGIOPATHY AFTER EXPERIMENTAL SUBARACHNOID HEMORRHAGE IN RATS

Proliferative angiopathy represents the morphological basis of delayed cerebral vasospasm. The initial vasoconstriction and endothelial dama ge of the vasospastic arteries leads to an exaggerated response of the smooth muscle cells within the media leading to subintimal thickening and myonecrosis. Heparin reduces the exposure of the media to platele t derived growth factor, a mitogen from aggregating platelets responsi ble for the migration and proliferation of the myofibroblasts. Since s ystemic heparin in the setting of a subarachnoid haemorrhage would be unacceptable, we have tested the effect of heparin on proliferative an giopathy by injecting autologous non-heparinized blood into two groups of rats (N = 12 each) and then inject the heparin into the spinal flu id of one group after one hour. We were able to show histologically th at intracisternal heparin injection after the subarachnoid haemorrhage has reduced the vascular wall changes to a great degree. Heparinizati on of the cerebrospinal fluid carried out in conjunction with early op eration for aneurysms may be a promising approach to prevent the morbi d complications of SAH in the clinical setting.