Correlation between rCBF and histological changes following temporary middle cerebral artery occlusion.

Correlations between changes in regional, cortical, cerebral blood flow (rCBF) and histological changes in the corresponding brain regions were examined following middle cerebral arterial occlusion in 24 cats. In all animals, the duration of arterial occlusion was 2 hours followed by 2 hours of recirculation. The animals were divided into 2 groups according to the severity of the observed histological damage. Severe cortical damage was observed in 8 cats (Group A), and, in the remaining 16 cats, little or no cortical damage was seen (Group B). There was a statistically significant difference between these 2 groups in the average rCBF values during ischemia. During recirculation, there was a prompt and uniform recovery of rCBF in animals in group B but a marked diversity; of rCBF ranging from hyperemia to oligemia in animals in group A. This diversity of rCBF reflects inhomogenous blood flow. This study indicates potential hazards for surgical revascularization in the aute stage of stroke when brain damage has progressed beyond a certain level.