Department of Pediatrics, Children's Hospital of Philadelphia and the Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA.
Division of Cardiothoracic Surgery, Children's Hospital of Philadelphia and the Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA.
Pediatr Res. 2022 May;91(6):1374-1382. doi: 10.1038/s41390-021-01525-3. Epub 2021 May 4.
Cerebral autoregulation mechanisms help maintain adequate cerebral blood flow (CBF) despite changes in cerebral perfusion pressure. Impairment of cerebral autoregulation, during and after cardiopulmonary bypass (CPB), may increase risk of neurologic injury in neonates undergoing surgery. In this study, alterations of cerebral autoregulation were assessed in a neonatal swine model probing four perfusion strategies.
Neonatal swine (n = 25) were randomized to continuous deep hypothermic cardiopulmonary bypass (DH-CPB, n = 7), deep hypothermic circulatory arrest (DHCA, n = 7), selective cerebral perfusion (SCP, n = 7) at deep hypothermia, or normothermic cardiopulmonary bypass (control, n = 4). The correlation coefficient (LDx) between laser Doppler measurements of CBF and mean arterial blood pressure was computed at initiation and conclusion of CPB. Alterations in cerebral autoregulation were assessed by the change between initial and final LDx measurements.
Cerebral autoregulation became more impaired (LDx increased) in piglets that underwent DH-CPB (initial LDx: median 0.15, IQR [0.03, 0.26]; final: 0.45, [0.27, 0.74]; p = 0.02). LDx was not altered in those undergoing DHCA (p > 0.99) or SCP (p = 0.13). These differences were not explained by other risk factors.
In a validated swine model of cardiac surgery, DH-CPB had a significant effect on cerebral autoregulation, whereas DHCA and SCP did not.
Approximately half of the patients who survive neonatal heart surgery with cardiopulmonary bypass (CPB) experience neurodevelopmental delays. This preclinical investigation takes steps to elucidate and isolate potential perioperative risk factors of neurologic injury, such as impairment of cerebral autoregulation, associated with cardiac surgical procedures involving CPB. We demonstrate a method to characterize cerebral autoregulation during CPB pump flow changes in a neonatal swine model of cardiac surgery. Cerebral autoregulation was not altered in piglets that underwent deep hypothermic circulatory arrest (DHCA) or selective cerebral perfusion (SCP), but it was altered in piglets that underwent deep hypothermic CBP.
脑自动调节机制有助于在脑灌注压发生变化时维持足够的脑血流（CBF）。体外循环（CPB）期间和之后脑自动调节功能受损可能会增加接受手术的新生儿神经损伤的风险。在这项研究中，通过探测四种灌注策略，在新生儿猪模型中评估了脑自动调节的改变。
将新生儿猪（n=25）随机分为持续深度低温心肺转流（DH-CPB，n=7）、深低温停循环（DHCA，n=7）、选择性脑灌注（SCP，n=7）于深低温时，或常温心肺转流（对照组，n=4）。在 CPB 开始和结束时，计算激光多普勒测量的 CBF 与平均动脉血压之间的相关系数（LDx）。通过初始和最终 LDx 测量值之间的变化来评估脑自动调节的改变。
DH-CPB 组的猪脑自动调节功能受损（LDx 增加）（初始 LDx：中位数 0.15，IQR[0.03，0.26]；最终：0.45，[0.27，0.74]；p=0.02）。DHCA 组（p>0.99）或 SCP 组（p=0.13）的 LDx 没有改变。这些差异不能用其他危险因素来解释。
在心脏手术的验证性猪模型中，DH-CPB 对脑自动调节有显著影响，而 DHCA 和 SCP 则没有。
大约一半接受心肺转流（CPB）心脏手术后的新生儿会出现神经发育迟缓。这项临床前研究采取了步骤来阐明和分离与 CPB 相关的心脏手术程序相关的潜在围手术期神经损伤风险因素，例如脑自动调节功能受损。我们展示了一种在心脏手术的新生儿猪模型中描述 CPB 泵流量变化期间脑自动调节的方法。在接受深低温循环停止（DHCA）或选择性脑灌注（SCP）的猪中，脑自动调节没有改变，但在接受深低温 CPB 的猪中，脑自动调节发生了改变。
