Two stage successive carotid artery occlusion surgeries in wistar rat reduce its mortality and depicts as a better model for vascular dementia

Chronic cerebral hypoperfusion induced vascular dementia (VD) constitutes a major cause for dementia in the geriatric population. Permanent-bilateral common carotid artery occlusion (P-BCCAO) in Wistar rat models are considered as accepted models for preclinical research on VD. It has been documented that the P-BCCAO rats undergo a brief period of acute severe ischemia immediately following P-BCCAO surgery. This offers a significant disadvantage in using this model to study chronic cerebral hypoperfusion induced VD in human beings. Moreover, the survival rate of this rat model is relatively low compared to other animal models being used for similar studies. Ten months-old male Wistar rats (n=12/group) were randomly divided into 4 groups as normal control, Sham-BCCAO, one stage P-BCCAO and two stage P-BCCAO. All rats were subjected to spatial and avoidance learning memory tasks and their brains were subjected to histopathalogical analysis. Both P-BCCAO groups of rats showed significant deficits (p <0.05) in spatial and avoidance learning-memory tasks & neuronal injury in CA1 subregion of hippocampus compared to NC. This two stage P-BCCAO rat model has better survival rate, less acute ischemic stress and better represents the human chronic cerebral hypoperfusion brain injury compared to conventional one stage P-BCCAO rate model.