Regional Cerebral Blood Flow after Subarachnoid Hemorrhage (SAH) in the RAT

Abstract

Current models of subarachnoid hemorrhage (SAH) in the rat involve either the direct injection of blood into the subarachnoid space^1,2 or arterial rupture after craniotomy.^3,4 Neither model simulates the phenomenon occurring in patients; the first, because it lacks an arterial rupture, and the second because of the need to open the cranium and thereby eliminating the acute and precipitous rise in ICP and a component of the ischemic insult that occurs after a SAH. Recently, a model involving the intravascular rupture of the middle cerebral artery (MCA) by a suture passed via the common carotid artery into the internal carotid artery to puncture the MCA has been described^5,6 which appears ideal because it duplicates the phenomenon in patients with respect to an arterial rupture, no craniotomy thereby allowing the rise in intracranial pressure to occur after rupture as it does in patients. Although changes in rCBF both qualitative and quantitative have been described for up to 2 hr after rupture, the changes occurring days after the hemorrhage to determine whether a delayed ischemic event occurs has not been determined. The objective of this study was to evaluate the changes in regional cerebral blood flow (rCBF) beyond days 1 and 3 postinsult.