An Experimental Study about Retrograde Cerebral Perfusion

1. 脑逆行灌注时脑组织血流量、耗氧量和二氧化碳析出量：与顺行灌注相比，脑逆行灌注提供的脑组织血流量为脑组织血流量的一半，耗氧量为脑组织血流量的三分之一，二氧化碳析出量为脑组织血流量的20%。然而，逆行脑灌注时，听脑干反应消失。脑逆行灌注几乎不能维持脑功能。与脑逆行灌注和循环骤停的比较：脑逆行灌注维持脑组织氧张力和ATP浓度高于循环骤停。脑逆行灌注减少了全身氧债，减少了部分氧的输送引起的脑缺血损伤。脑逆行灌注的最佳灌注条件：脑逆行灌注时脑脊液压、耗氧量随静脉压成比例升高。然而，脑组织血流量在静脉压大于25mmhg时没有增加。静脉压高于25mmHg，伴颅内压增高，限制脑组织血流量，可引起脑水肿。静脉压25mmHg可能是rcp的最佳压力。彩色微球法全身组织血流：与顺行体外灌注相比，逆行脑灌注可均匀灌注约20%的血流，无侧化。仅通过上腔静脉进行逆行灌注，使血液循环进入内脏器官，并与双颌系统相连。脑逆行灌注时血温的影响：脑逆行灌注时，静脉-动脉分流打开，毛细血管血流量随血温成比例减少。

1. Cerebral tissue blood flow, oxygen consumption and carbon dioxide exdation during retrograde cerebral perfusion : Retrograde cerebral perfusion provided half a cerebral tissue blood flow and showed a third of oxygen consumption and 20% of carbon dioxide exudation compared with antegrade extracorporation. However, the auditory brainstem responses disappeared during retrograde cerebral perfusion. Retrograde cerebral perfusion hardly maintained cerebral function.2. Comparison with retrograde cerebral perfusion and circulatory arrest : Retrograde cerebral perfusion maintained oxygen tension and ATP concentrations in cerebral tissue higher level than circulatory arrest. Retrograde cerebral perfusion reduced oxygen debt of whole body and cerebral ischemic damage due to delivery of some oxygen.3. The optimum perfusion condition of retrograde cerebral perfusion : The cerebrospinal fluid pressure and oxygen consumption increased in proportion with venous pressure during retrograde cerebral perfusion. However, cerebral tissue blood flow did not increase above 25 mmHg of venous pressure. High venous pressure above 25mmHg, was associated with high intracranial pressure which restricts cerebral tissue blood flow and may cause brain edema. Venous pressure opf 25mmHg may be the optimum pressure for RCP.4. Tissue blood fow of whole body with colored microsphere method : The brain was perfused about 20% of blood flow evenly without latelarization by retrograde cerebral perfusion compared with antegrade extracorporeal perfusion.Retrograde perfusion only via the superior vena cava provided blood circulation into the visceral organs with the connection of bicaval system.5. Effect of blood temperature during retrograde cerebral perfusion : During retrograde cerebral perfusion, veno-arterial shunt opened and capillary blood flow decreased in proportion with blood temperature did.