Effect of Intracarotid Cold Saline Infusion during Cerebral Ischemia on Brain Edema in the Rabbit

뇌허혈기동안 경동맥으로 냉각 생리식염수 주입이 허혈후 뇌부종에 미치는 영향

Ischemia results when the decrease in tissue perfusion exceeds the tissues ability to increase an oxygen extraction from the blood. Brain edema has been defined as an abnormal accumulation of fluid within brain parenchyma associated with a volumetric enlargement of the brain tissue. In most instances, the labelling of edema as vasogenic or cytotoxic is only relative. For cerebral protection, there were many possible techniques which could increase or maintain cerebral perfusion and reduce cerebral metabolic demand for oxygen. This study was carried out the effect of mild brain hypothermia which was induced by infusion with cold saline into the carotid artery, during brief episodes of transient global ischemia on postischemic brain edema in rabbit. Eight rabbits were anesthetized with halothane and mechanically ventilated with oxygen. For isolated cerebral perfusion, polyethylene catheter was inserted left carotid artery for infusion of cold saline, external carotid artery was ligated, vertebral arteries were cautherized, right carotid artery was snared for ischemia and femoral artery and vein were also canulated for monitoring and drug treatment. At 3 hours After transient global ischemia, specific gravity of cerebral cortex and hippocampus was compared with no-perfusion group , perfusion with cold saline group and normal group. There was no significant differences in physiologic variables among the groups before transient global ischemia. But during transient global ischemia, brain temperature of perfusion group was decreased when compared to no perfusion group. Specific gravity of cerebral cortex and hippocampus of no-perfusion group and perfusion group was statistically significant when compared to normal group (p<0.01). The results of this study suggested that mild brain hypothermia with intracarotid cold saline infusion during brief episodes of transient global ischemia had decreased postischemic brain edema in rabbit.

건전한 뇌의 수분 함량은 뇌혈류장벽의 투과성, 혈관내 정수압, 혈장의 삼투압 Na-K-APTase pump의 기능에 의해서 결정된다. 뇌허혈에 의해 이러한 기전이 파괴되면 세포 사이의 정상적인 수분이동이 영향을 받게 된다. 그러므로 뇌허혈이 생길 수 있는 수술의 경우에 분리 뇌관류를 하면 뇌허혈시 발생하는 독성 대사물을 발생을 억제하고 뇌혈류의 분포를 개선하여 신경세포의 손상을 줄이고 뇌부종을 감소시킬 수 있으리라 생각되어 토끼에서 분리 뇌관류 모델을 만들어 허혈 유도 후 관류군과 비관류군의 대뇌피질과 해면구의 비중을 정상 토끼와 비교하였다. 뇌허혈에 의해 관류군과 비관류군의 뇌비중이 유의하게 감소하여 뇌부종이 발생하였음을 나타내었고, 비관류군이 판류군보다 유의하게 감소하여 뇌부종이 더욱 현저하였던 것으로 보아 냉각 식염수로 뇌관류한 것이 뇌부종의 발생을 억제한 것으로 생각된다.