脑超深低温下猴脑血流阻断时间窗的研究

目的 探明选择性脑超深低温技术对常温条件下猴脑血流阻断有效治疗时间窗.方法 10只恒河猴分为3组:常温组(n=3);深低温I组(n=4):脑血流阻断15min开始深低温治疗;深低温Ⅱ组(n=3):脑血流阻断20min开始深低温治疗.双侧颈动脉和颈静脉系统分离、脑血流阻断建立严重脑缺血缺氧模型.深低温组动物通过一侧颈内动脉灌注4~C林格氏液同侧颈内静脉回流,阻断其他颈动脉和颈静脉血管,脑温维持在(15.3±1.04)℃、中心体温(35.1±1.10)℃.维持深低温60min后恢复正常脑血流.常温组动物采用相同方法脑灌注37℃林格氏液.观察猴生存率、脑神经功能状况和病理形态.结果 4只脑血流阻断15min开始深低温治疗的猴死亡3只、1只长期存活;3只脑血流阻断20min开始深低温治疗和3只常温组猴全部死亡.死亡动物脑干出现神经元死亡.结论 常温条件下严重或完全脑缺血缺氧有效低温复苏时间为10min、15min内低温复苏成功率高,15min以上开始深低温复苏效果差.

Therapeutic window of selective cerebral ultra-profound hypothermia in treatment of occlusion of cerebral blood flow in monkey

Objective To determine the therapeutic window of selective cerebral profound hypothermia in treatment of occlusion of cerebral blood flow. Methods Ten rhesus monkeys were divided into 3 groups,normothermia group (n=3 ) ; profound hypothermia I (n=4) : initiated cooling at 15 minutes after ischemia; profound hypothermia 1I (n = 3) : initiated cooling at 20 minutes after ischemia. To establish the severe cerebral ischemia,all carotid arteries and jugular veins were occluded. Selective cerebral profound hypothermia was established by peffusion of 4~C cooling Linger's liquid through right internal carotid artery and flow out of jugular vein,brain temperature reached ( 15.3±1.04 )℃ while the body temperature maintained (35. 1±1. 10 )℃ for 60 minutes. The mortality, cerebral functions, and pathological examination were evaluated. Other four monkeys underwent cerebral perfusion of 37℃ Linger's liquid with similar methods. Results 3 monkeys cooling at 15 minutes after ischemia were dead and only 1 monkey survived. 3 monkeys cooling at 20 minutes after ischemia and 3 monkeys in normothermia all were dead. Neuron death was found in medulla in dead monkeys. Conclusion Therapeutic window of selective cerebral ultra-profound hypothermia initiated within 10 minutes is effective,partially effective within 15 minutes and no effective after 15 minutes after severe or complete cerebral isehemia.