EXPERIMENTAL STUDIES OF RETROGRADE CEREBRAL PERFUSION UNDER CONDITION OF PROFOUND HYPOTHERMIA

本研究旨在评价深低温条件下逆行脑灌注对停搏的有益作用。将成年杂种犬置于体外循环下，并将鼻咽温度冷却至20 ℃。在此温度下，进行低温停循环和逆行脑灌注（RCP）60分钟。经双侧上颌静脉行逆行脑灌注，调节逆行流量使颈外静脉平均灌注压分别维持在10、20、30mmHg。我们还研究了在RCP期间通过IVC插管阻断血流对脑代谢的影响，并研究了脉动流对逆行脑灌注的影响。这些研究结果表明，中枢神经系统的低温，氧的供应，代谢产物的排泄，有氧代谢，RCP时灌注压以20mmHg为宜，术中阻断下腔静脉血流对脑组织保护作用更强，而逆行脑灌注时采用搏动性血流灌注法，可使脑组织缺血性坏死程度减轻，脑组织缺血性坏死程度减轻。与非脉动流相比，流动具有控制脑水肿的可能性。

This investigation was to evaluate the beneficial effect of retrograde cerebral perfusion during ciculatory arrest under condition of profound hypothermia. Adult mongrel dogs were placed on cardiopulmonary bypass and were cooled to a nasopharyngeal temperature of 20ﾟC.At this temperature, hypothermic circulatory arrest and retrograde cerebral perfusion(RCP)were performed for 60 minutes. Retrograde cerebral perfusion was performed via the bilateral maxillary veins, and retrograde flow rate was regulated to maintain a mean perfusion pressure of 10,20,30mmHg in the external jugular vein respectively. We also investigated the effects on cerebral metabolism of clamping blood flow through the IVC cannula during RCP and also investigated the effects of pulsatile flow on retrograde cerebral perfusion. Results from these investigation suggest that hypothermia of the central nervous system, the supply of oxygen, the excretion of metabolites, aerobic metabolism, and the cerebral A Tp level were maintained by RCP.A perfusion pressure of 20mmHg was appropriate for RCP and clamping of the venous blood flow through the IVC cannula during RCP is a more protective procedure for cerebral tissue during RCP.And retrograde cerebral perfusion with pulsatile flow has the possibility to control brain edema as compared with non-pulsatile flow.