The Heart Hospital, University College London, London, UK.
Wellstar Cardiovascular Surgery, Atlanta, GA, USA.
Cardiol Young. 2021 May;31(5):769-774. doi: 10.1017/S1047951120004606. Epub 2020 Dec 23.
The contribution of neonatal cyanosis, inherent to cyanotic congenital heart disease, to the magnitude of neurologic injury during deep hypothermic circulatory arrest has not been fully delineated. This study investigates the impact of cyanosis and deep hypothermic circulatory arrest on brain injury.
Neonatal piglets were randomised to placement of a pulmonary artery to left atrium shunt to create cyanosis or sham thoracotomy. At day 7, animals were randomised to undergo deep hypothermic circulatory arrest or sham. Arterial oxygen tension and haematocrit were obtained. Neurobehavioural performance was serially assessed. The animals were sacrificed on day 14. Brain tissue was assessed for neuronal necrosis using a 5-point histopathologic score.
Four experimental groups were analysed (sham, n = 10; sham + deep hypothermic circulatory arrest, n = 8; shunt, n = 9; shunt + deep hypothermic circulatory arrest, n = 7). Cyanotic piglets had significantly higher haematocrit and lower partial pressure of oxygen at day 14 than non-cyanotic piglets. There were no statistically significant differences in neurobehavioural scores at day 1. However, shunt + deep hypothermic circulatory arrest piglets had evidence of greater neuronal injury than sham animals (median (range): 2 (0-4) versus 0 (0-0), p = 0.02).
Cyanotic piglets undergoing deep hypothermic circulatory arrest had increased neuronal injury compared to sham animals. Significant injury was not seen for either cyanosis or deep hypothermic circulatory arrest alone relative to shams. These findings suggest an interaction between cyanosis and deep hypothermic circulatory arrest and may partially explain the suboptimal neurologic outcomes seen in children with cyanotic heart disease who undergo deep hypothermic circulatory arrest.
新生儿紫绀是紫绀型先天性心脏病所固有，但其对深低温停循环期间神经损伤的程度尚未完全阐明。本研究旨在探讨紫绀和深低温停循环对脑损伤的影响。
将新生仔猪随机分为行肺动静脉分流术造成紫绀的绀症组或假开胸手术的假手术组。在第 7 天，动物随机接受深低温停循环或假手术。记录动脉血氧分压和血细胞比容。连续评估神经行为表现。第 14 天处死动物。采用 5 分病理评分法评估脑组织神经元坏死情况。
分析了 4 个实验组（假手术组，n=10；假手术+深低温停循环组，n=8；分流组，n=9；分流+深低温停循环组，n=7）。与非紫绀仔猪相比，紫绀仔猪在第 14 天的血细胞比容更高，而部分氧分压更低。在第 1 天，神经行为评分无统计学差异。然而，分流+深低温停循环组的仔猪比假手术组的仔猪有更多的神经元损伤证据（中位数（范围）：2（0-4）比 0（0-0），p=0.02）。
行深低温停循环的紫绀仔猪与假手术组相比，神经元损伤增加。与假手术组相比，单独发生紫绀或深低温停循环均未观察到明显的损伤。这些发现提示紫绀和深低温停循环之间存在相互作用，这可能部分解释了在患有紫绀型先天性心脏病并接受深低温停循环的儿童中观察到的神经功能结果不理想的原因。
