Structural changes of the intradural arteries following subarachnoid hemorrhage

Abstract

✓ The histology of the intradural arteries was studied in 12 consecutive autopsy cases of patients dying 1 day to 15 months after their initial spontaneous subarachnoid hemorrhage. In all patients surviving 4 weeks or more and in one surviving 4 days, the lumina of the intracranial arteries were narrowed by subendothelial granulation tissue which thickened the intima. In all seven cases with structural changes in the intracranial arteries, vessels near the site of hemorrhage were involved; in four cases vessels remote from the site of hemorrhage were also involved. Changes were usually restricted to large arteries with a prominent muscular layer and confined to the subarachnoid space. The presence and degree of intimal thickening correlated with the distribution and amount of subarachnoid blood or its breakdown products. This process apparently does not represent an obliterative endarteritis involving vessels exclusively supplying infarcted brain, but is probably a reaction to mechanical or anoxic damage to the intima following vasoconstriction. It is suggested that this arterial structural change might be confused with delayed or prolonged “vasopasm.”

Cerebral vasospasm in a double-injection model in rabbit

“…Because of its proximity in philogeny to primates [21], rabbits possess comparable cerebrovascular morphological features that might also be involved in the pathogenesis of ischemic complications of SAH [6,7,17,25].…”

The Time Course of Intracranial Pathophysiological Changes following Experimental Subarachnoid Haemorrhage in the Rat

“…Studies of cerebral vessels obtained at operation and post mortem in such patients have revealed the early occurrence in narrowed arterial segments of myo necrosis affecting a number of the smooth muscle cells of the media. This is followed in some later cases by a phase of intimal thickening and subinti mal proliferation (Crompton, 1964;Conway and McDonald, 1972;Hughes and Schianchi, 1978;Peerless et aI., 1980;Smith et aI. , 1985).…”

Intimal Change following Subarachnoid Hemorrhage Resulting in Prolonged Arterial Luminal Narrowing

“…' 22,24) In such severe cases, it has been reported that organic changes occurring in the arterial wall may be responsible for narrowing of the vascular lumen, rather than spastic contraction of smooth muscles in the arterial wall. 6,12) We examined the vascular luminal surface of the narrowed arteries in human autopsy cases of SAH due to the ruptured aneurysm by scanning electron microscopy and found that luminal surfaces of the spastic arteries were not covered with endothelial cells and moreover, some were covered with crisscrossing fibrin nets. This made us to review the autopsy specimens of the rup tured aneurysm with SAH.…”