Impact of selective carotid artery hypothermia on cerebral edema and perfusion pressure after acute focal cerebral ischemia in rabbits

Abstract

Objective To explore the impact of selective carotid artery hypothermia on cerebral edema and perfusion pressure after acute focal cerebral ischemia in rabbits.Methods Thirty-two male New Zealand white rabbits were randomly divided into middle cerebral artery occlusion (MCAO) group (n=8),MCAO+cold saline infusion groups (30 and 60 min perfusion subgroups,Ⅰ1 and I2 groups,n=8),MCAO+38 ℃ saline infusion group (Ⅰ3 group,n=8).Rectal temperature,heart rate,mean arterial pressure,blood gas (pH,PO2,PCO2) and glucose were detected 15 min before MCAO,and 3 and 4 h after surgery.Intracranial pressure and mean arterial pressure were measured to calculate the perfusion pressure before MCAO,and 1,3,6,12,24 and 48 h after surgery.The cerebral edema extent was measured with TTC staining 48 h after MCAO.Results Baseline data between groups balanced (all P＞0.05).Cerebral perfusion pressure at different time points were significantly different (P＜0.05); cerebral perfusion pressure within 3 h after MCAO continued to decrease,then maintained at a relatively stable level.There was significant difference of edema index between the groups (P＜0.05); edema index in I2 group was significantly lower than that in the M and Ⅰ3 groups (P＜0.05).Conclusion Selective carotid artery hypothermia for 60 min significantly reduces cerebral edema and increases cerebral perfusion pressure,which is condueive to the neuronal protection after MCAO. Key words: Acute focal cerebral ischemia; Selective hypothermia; Cerebral edema; Cerebral perfusion pressure