不同灌注方法对深低温停循环下脑保护的实验研究

目的探讨不同灌注方法在深低温停循环下（DHCA）的脑保护的作用。方法实验动物选用健康白乳猪幼猪（农科院提供）40只。随机分为4组，每组10只。A组：单纯DHCA组；B组：DHCA＋逆行性脑灌注（RCP）；C组：DHCA＋单侧顺行性脑灌注（U—SACP）；D组：DHCA＋双侧顺行性脑灌注（B—SACP）。对照分析四组组间分别于CPB前（T1）、DHCA后30min（T2）、60min（T3）、90min（T4）和复温再灌注30min（T5）氧摄取率的变化。采用原位末端标记法（TUNEL染色法）观察和测定脑组织神经细胞凋亡的情况。结果与A组相比，B组、C组和D组可显著减少幼猪DHCA后神经细胞凋亡数目（P〈0．05），T2、T3和T4 3个时间窗脑氧摄取率明显低于A组，差异有显著意义（P〈0．05）。A组可见明显神经细胞凋亡改变，B组仅见中等程度神经细胞凋亡改变，C组和D两组见少量神经细胞凋亡改变，A组与B组，C组和D组、B组与C组和D组差异具统计学意义（P〈0．05），但是C组和D组差异没有统计学意义（P〉0．05）。结论SACP与RCP脑保护作用均优于DHCA，U—SACP与B—SACP脑保护作用好于RCP，但是两者差距没有统计学意义。

Experimental Study of Different Perfusion Methods and Neuroprotection during Deep Hypothermic Circulatory Arrest

OBJECTIVE To evaluate the protective effect of different perfusion during deep hypothermic circulatory arrest（DHCA）. METHODS Fourty healthy baby pigs were randomly divided into four groups （10 pigs per group）. Grouup A：simple DHCA, Group B：DHCA ＋ retrograde cerebral perfusion （RCP） , Group C：DHCA ＋ unilateral selective antegrade cerebral perfusion （ U - SACP ） , Group D ： DHCA ＋ bilateral selective antegrade cerebral perfusion （ B - SACP）. Measure oxygen enhancement ratio（OER） from blood which were taken in different window around DHCA. Neural apoptosis was identified by TUNEL in the brain. Comparely analysis the change of OER and the depression of neural apoptosis in the brain among four groups was performed. RESULTS OER levels were significantly difference at post DHCA 30 min（T2） , 60min （T3） , 90 min （T4） between group A and group B,C,D （ P 〈0.05）. The number of neural apoptosic cells in group B, C, D were decreased significantly during DHCA （ P 〈 0.05 ）. The level of apoptosic cells in group B was much higher than that in group C and D（ P 〈0.05） ,while that in group C was the same as the group D （ P 〉 0.05 ）. CONCLUSION DHCA ＋ RCP and DHCA ＋ SACP are more both effective methods than DHCA on cerebral protection while the latter is more suitable. U - SACP and B - SACP are better than DHCA ＋ RCP, but there was no difference between group C and D.