Intimal proliferation of cerebral arteries after subarachnoid blood injection in pigs.

A model of experimental subarachnoid hemorrhage in young pigs has been created using two subarachnoid blood injections. Cerebral arteries of the pig demonstrate intimal proliferation and medial necrosis 10 days after experimental blood injection; this appears to be a reaction to arterial injury. The similarity between the arterial reaction to subarachnoid blood and the general process of atherosclerosis is noted, and steps have been taken to insure that the vasculopathy described is truly a response to the injected blood. The authors conclude that the intimal proliferation observed between 1 and 2 weeks after experimental subarachnoid blood injection is an indicator of arterial injury and is, therefore, a good end point for further studies.