Intimal change following subarachnoid hemorrhage resulting in prolonged arterial luminal narrowing.

Abstract

The luminal surface of the cerebral arteries was examined by scanning electron microscopy. Preliminary findings of the cases which succumbed to the aneurysmal rupture are reported with those obtained by light microscopic examinations of old autopsy specimens of the ruptured aneurysm. On SEM, the endothelial cells were lost on the luminal surface of the cerebral arteries and some were covered with fibrin meshwork confining red blood cells and other corpuscles. These findings were interpreted as endothelial injury with denudation of elastica and resulting mural thrombus formation. Light microscopic examination revealed that cerebral arteries which had had narrowing after SAH showed concentrically thickened intimal layer and the presence of rich vascularization partly in the subintimal layer. These histological pictures were interpreted as organized mural thrombus. Possible role which mural thrombosis plays in the pathogenesis of prolonged narrowing after SAH from the rupture of an aneurysm and its clinical significance, especially in connection with antifibrinolytic treatment, is discussed.