The Experimental Study Of Different Flow Rate For Regional Cerebral Perfusion Under Deep Hypothermic Circulatory Arrest Bypass In Piglets

Objective To establish a safe and effective regional cerebral perfusion (RCP) model in piglets under deep hypothermic cardiopulmonary bypass (CPB), and to explore the optimal flow rate for RCP under deep hypothermic CPB in piglets, and provide theoretical basis in cerebral protection for infants attacked by congenital heart disease.Methods Twenty healthy pigelets with average weight at6.4±0.6kg and age at23.7±2.1days, were randomly assigned four groups with5piglets in each group by random digital table. The control group is a simple deep hypothermic circulatory arrest (DHCA) group, and the experimental groups consist of three different flow rate RCP groups including RCP25group with flow rates at25ml/(kg-min), RCP50group with flow rates at50ml/(kg-min), and RCPgo group with flow rates at80ml/(kg-min). Serum samples for S-100β protein, neuron-specific enolase (NSE), cerebral oxygen extraction (CEO2) at six time points(T1:before CPB, T2:before DHCA or RCP, T3:10minutes after RCP, T4: before stopping CPB(T4), T5:1hour after CPB,T6:2hours after CPB), caspase3and pathomorphologic changes in cerebral cortex were detected to estimate the effects of cerebral protection.Results The concentration of S-100(3protein and NSE significantly increased at T4, and accomplished peak point at T5(P<0.05). They are significantly lower in the RCP50group than those in the DHCA group and in the RCP80group(P<0.05). While compared to the RCP25group, there is no significant difference between them (P>0.05). There was no significant difference in cerebral oxygen extraction (CEO2) at T1(P>0.05), while it decreased significantly at T2(P<0.05). The concentration of CEO2in the DHCA group, the RCP25gorup, and the RCP50group increased at T3, while it declined slightly in the RCPso group, but there was no significant difference between the groups(P>0.05). The CEO2in the RCP25group and the RCP50group at T4is similar to that at baseline (P<0.05). Three different flow rates in the RCP groups significantly decreased compared with the DHCA group in the concentration of caspase3in cerebral cortex (F=23.54,P< 0.01). Compared to the RCP25group and the RCP50group, caspase3in the RCPg0group increased significantly (F=23.54,P<0.01), and there is no significant difference between the RCP25group and the RCP50group (P>0.05).The form and structure of the nerve cells in DHCA group and RCPso group is abnormal, and Nissl body disappears. While in RCP50group and RCPso group are basically normal, and part of Nissl body is less or disappears.Conclusion The RCP model in piglets under deep hypothermic CPB established by us is safe and effective; and it can provide a reliable experimental animal model for infants attacked by complex congenital heart disease (CCHD) in cerebral protection aspects during perioperative period; And the optimal flow rate for RCP in cerebral protection under deep hypothermic CPB in piglet’s model is between25ml/(kg-min) and50ml/(kg-min).