Constrictive endarteropathy following experimental subarachnoid hemorrhage

Abstract

Rhesus monkeys were subjected to subarachnoid hemorrhage by either the Introduction of blood iato the subarachooid space or by mechanically rapturing the middle cerebral artery. Local cerebral blood flow, rascular compliance studies, and histological studies (light and electron microscope) were made of tbe ressels of all animals. In anlmals hemorrhaged vla vascular rapture, subintimal swelling and thickening was minimally present by 3 days, becoming progressively more serene by one month. Such changes consisted of severe subintimal proliferation, flbrosis of tbe medial smooth muscle layer and interruption of the internal elastic membrane. Cells in tbe subintimal proliferate areas examined by electroomicroscopy were seen to hare ultrastructural characteristics of smooth muscle. In the subarachnoid-injected hemorrhaged animals, there was no evidence of intimal proliferation or other vascular changes, which was also true of all control vessels. There was a decrease in wall elasticity of vessels exposed to mechanical rapture when compared to those exposed only to injected subarachnoid Mood or normal vessels. Local cerebral blood flow was affected very little following the 2 methods of subarachnoid hemorrhage. © 1981 American Heart Association, Inc.