Establishment of antegrade selective cerebral perfusion for a brain with old infarction during aortic arch operation

目的：探讨顺行选择性脑灌注(ASCP)期间pH管理对陈旧性脑梗塞犬模型的影响。方法：采用柱状硅胶栓塞法建立犬脑梗塞模型。在脑梗塞模型中，狗有明显的神经功能缺陷，存活4周或更长时间。24只杂种犬在ASCP下行深低温(正常组，α-STAT：A组(n=6)，pH-STAT：B组(n=6)，梗死组：A-STAT：C组(n=6)，pH-STAT：D组(n=6))。术中检测血清丙二醛(MDA)和谷氨酸浓度，测定中枢传导时间(CCT)和体感诱发电位波幅。结果：C组术中降温期28℃时SmvO2显著低于其他两组(P<0.05)，静脉-动脉乳酸差值显著高于其他两组(P<0.05)。从降温28℃到复温28℃，pH-STAT组动脉血PaCO_2明显高于α-STAT组，pH值显著低于α-STAT组(p&lt；0.05)。术中其他参数在两组间没有任何差异。C组血清丙二醛、谷氨酸浓度明显升高，CCT明显延长，C组和D组的波幅比值明显降低。结论：ASCP辅助下的主动脉弓手术期间的pH稳态管理，可为陈旧性脑梗塞患者提供更有效的保护。

Objective : We sought to examine the influence of pH management during antegrade selective cerebral perfusion (ASCP) on brains with or without old infarction in a canine model.Methods : A cerebral infarct canine model was created by means of injection of cylindrical silicon embolus. The dogs had obvious neurological deficits and survived for 4 weeks or more included in the cerebral infarct model. Deep hypothermia with ASCP was performed in 24 mongrel dogs (intact group ; alpha-stat : Group A (n=6), pH-stat : Group B (n=6), infarct group ; alpha-stat : Group C (n=6), pH-stat : Group D (n=6)). The serum concentration of malondialdehyde (MDA) and glutamate were measured, and central conduction time (CCT) and amplitude in somatosensory evoked potentials were assessed during operation. Results : During surgery, in the group C, SmvO_2 was significantly lower (p<0.05) and venous-arterial lactate difference was significant higher (p<0.05) than in the other groups at 28℃ in the cooling phase. The pH-stat group showed significantly higher arterial PaCO_2 and lower pH than those in the alpha-stat group during the period from the cooling 28℃ to the rewarming 28℃ (p<0.05). The other intraoperative parameters did not show any differences among the groups. In the group C, the serum concentration of MDA and glutamate significantly increased and CCT significantly prolonged, and in the group C and group D, the amplitude ratio decreased significantly.Conclusions : pH-stat management, during aortic arch operation with the aid of ASCP, may provide the more effective protection for the brain with old infarction.