深低温停循环下脑保护液的实验研究

【作者】 罗国华；

【导师】 吴清玉；

【作者基本信息】 中国协和医科大学 ， 心血管外科学， 1999， 博士

【摘要】 目的：随着心血管外科技术的不断发展，脑保护问题日显突出。目前常用的脑保护方法深低温停循环（DHCA），深低温停循环选择性脑灌注（DHCA-SCP），深低温停循环逆行脑灌注（DHCA-RCP）各有其自身的局限性。本研究旨在为临床工作提供一种较为理想的脑保护方法。方法：犬升主动脉右心房插管建立体外循环，降温到鼻咽温18℃时停循环。对照组单纯DHCA 120分钟，实验组于停循环后，经双侧颈动脉灌注充氧脑保护液。首次剂量为25ml／kg，以后每隔30分钟灌注一次，灌注量为12.5ml／kg。对照组及实验组均于停循环120分钟后恢复循环并复温。两组动物分别于体外循环（CPB）前，停循环120分钟后及恢复循环45分钟后经预先开窗的颅顶部取大脑皮层组织测定其ATP，MDA，TXB2，6-Keto-PGF_1α的含量，用NADPH-黄递酶染色法测定其NADPH阳性细胞的数量，并作透射电镜的检查。结果：DHCA 120分钟及恢复循环45分钟后，实验组大脑皮层组织ATP的含量均明显高于对照组（P＜0.05及P＜0.01）。DHCA 120分钟后，大脑皮层组织MDA，TXB2及6-Keto-PGF_1α的含量两组均没有明显差异（P＞0.05），恢复循环45分钟后，对照组大脑皮层组织MDA的含量及TXB₂的含量均明显高于实验组（P＜0.001及P＜0.05），对照组大脑皮层组织6-Keto-PGF_1α的含量明显低于实验组（P＜0.01）。DHCA120分钟后，对照组大脑皮层组织NADPH阳性神经细胞的数量明显多于CPB前（P＜0.05），恢复循环45分钟后，其数量进一步增加，与DHCA 120分钟后比较，P＜0.01。实验组无此变化。透射电镜检查显示对照组大脑皮层组织于DHCA 120分钟及再灌注45分钟后出现明显异常，线粒体肿胀，嵴断裂，空泡形成，线粒体膜结构破坏等。实更多还原

【Abstract】 OBJECTIVE: With the development of the technique of cardiovascular surgery, the problem of cerebral protection is becoming more and more important. At present the method of cerebral protection common used such as deep hypothermic circulatory arrest（DHCA）, DHCA selective cerebral perfusion （DHCA-SCP）, DHCA retrograde cerebral perfusion （DHCA-RCP） has its own disadvantage respectively. The purpose of the present study was to provide an optimal method of cerebral protection for the clinical application. METHOD: Ten mongrel dogs were divided into two groups, which were placed on CPB via the ascending aorta and right atrium, cooled to a nasopharyngeal temperature of 18°C and submitted 120 minutes of total circulatory arrest. 5 dogs in the control group did not receive cerebralplegia and 5 dogs in the experimental group received oxygenated cerebralplegic infusion through the bilateral common carotid arteries. The dosage of the cerebralplegic infusion was 25ml/kg bodyweight at the onset of arrest, followed by 12.5ml/kg at 30-minute intervals during the arrest period. All animals were re-established the CPB and rewanned after 120 minutes of circulatory arrest. Cerebral cortex was collected to study adnosine triphosphate（ATP）, malondialdehyde（MDA）, thromboxane B₂（TXB₂）, 6-Keto-PGF_1α, nitric oxide synthase（NOS） and ultrastructure at the time point of pre-CPB, 120 minutes of circulatory arrest and at 45 minutes of reperfusion in all animals. RESULTS: The level of ATP in the experimental group is higher significantly than that in the control group at 120 minutes of circulatory更多还原