Comparative Experimental Srudy of Cerebral Protection during Aortic Arch Reconstruction

用体感诱发电位（SEP）评价逆行脑灌注（RCP）、选择性脑灌注（SCP）和低温停循环（HCA）对犬脑水肿的影响。19只杂种犬随机分为3组，分别进行RCP（n=8）、SCP（n=6）和HCA（n=5）90 min。大脑温度保持在20摄氏度，然后逐渐复温至正常温度。RCP或HCA开始后SEP完全消失，除HCA组1例外，其余均未恢复。RCP组8例中5例SEP恢复正常，波幅低于正常值的50%。在SCP组中，所有病例均恢复。与术前相比，RCP期间仅获得2%的脑血流量（CBF）和约3%的脑氧代谢率（CMR 02）。脑组织ATP和水含量分析支持上述结果。与HCA相比，RCP具有一定的脑保护优势，但不能提供足够的CBF来维持脑功能。SCP是需要脑保护90分钟的牙弓重建中最安全的方法。

Retrograde cerebral perfusion (RCP), selective cerebral perfusion (SCP) and hypothermic circulatory arrest (HCA) were compared in terms of their effect on cerebral fumction of dogs as evaluated by somatosensory evoked potentials (SEP). Nineteen mongrel dogs were divided into three groups and subjected to RCP (n=8), SCP (n=6) and HCA (n=5) for 90 minutes. Brain temperatures were held at 20ﾟC and then rewarmed gradually to normal temperature. SEP completely disappeared as soon as RCP or HCA started and never recovered except one case in the HCA group. However SEP reappeared in five cases out of eight in the RCP group, the amplitude was below 50% of normal. In the SCP group, it recovered in all cases. Only 2% of cerebral blood flow (CBF) and about 3% of cerebral metabolic rate for oxygen (CMR02) were obtained during RCP compared to pre-operation value. The analysis of cerebral tissue ATP and water content supported these results. RCP had some advantage for cerebral protection compared with HCA,but could not supply sufficient CBF to maintain brain function. SCP was the safest method in arch reconstruction that requires cerebral protection for 90 minutes.