Chen Xiangyu, Yuan Haiyun, Liu Jiawei, Zhang Neichuan, Zhou Chengbin, Huang Meiping, Jian Qifei, Zhuang Jian
School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou, 510000, China.
Guangdong Provincial Key Laboratory of South China Structural Heart Disease, Department of Cardiovascular Surgery, Guangdong Provincial People's Hospital, Guangdong Cardiovascular Institute, Guangdong Academy of Medical Sciences, Guangzhou, 510000, China.
Cardiovasc Eng Technol. 2020 Jun;11(3):268-282. doi: 10.1007/s13239-020-00459-x. Epub 2020 Feb 18.
Additional pulmonary blood flow (APBF) can provide better pulsating blood flow and systemic arterial oxygen saturation, while low blood pulsation and low oxygen saturation are defects of the Fontan and Glenn procedure. Studying the hemodynamic effect of APBF is beneficial for clinical decisions. This study aimed to explore the effect on particle washout, as well as the differences among the sensitivities of both different hemodynamic parameters and different procedures to APBF.
The patient-specific clinical datasets of a patient who underwent bilateral bidirectional Glenn (BBDG) with APBF were enrolled in this study, and using these datasets, Glenn- and Fontan-type artery models were reconstructed. A series of parameters, including the total caval flow pulsatility index (TCPI), indexed energy loss (iPL), wall shear stress (WSS), systemic arterial oxygen saturation (Sat), particle washout time (WOT), pressure in the right superior vena cava (P), pulmonary flow distribution (PFD) and hepatic flow distribution (HFD), were computed from computational fluid dynamic (CFD) simulation to evaluate the hemodynamic effect of APBF.
The result showed that APBF led to better iPL and Sat but worse P and heart load accompanied by a great impact on HFD, making hepatic flow easier to perfuse the side without MPA and APBF. The increase in the APBF rate also effectively results in larger flow pulsation, region velocity, and wall shear stress and lower WOT, and this effect may be more effective for patients with persistent left superior vena cava (PLSVC). However, APBF might have little effect on PFD. Furthermore, APBF might affect WOT, iPL and HFD more significantly than P and has a greater improvement effect in patients with poorer iPL and WOT.
Moderate APBF is not only a measure to promote pulmonary artery growth and systemic arterial oxygen saturation but also an effective method against endothelial dysfunction and thrombosis. However, moderate APBF is patient-specific and should be determined based on hemodynamic preference that leads to desired patient outcomes, and care should be taken to prevent P and heart load from being too high as well as an imbalance in HFD.
额外的肺血流量（APBF）可提供更好的搏动血流和体动脉血氧饱和度，而低血流搏动和低血氧饱和度是Fontan和Glenn手术的缺陷。研究APBF的血流动力学效应有助于临床决策。本研究旨在探讨其对颗粒清除的影响，以及不同血流动力学参数和不同手术对APBF敏感性的差异。
本研究纳入了一名接受双侧双向Glenn（BBDG）联合APBF治疗患者的特定临床数据集，并利用这些数据集重建了Glenn型和Fontan型动脉模型。通过计算流体动力学（CFD）模拟计算了一系列参数，包括总腔静脉血流搏动指数（TCPI）、指数能量损失（iPL）、壁面剪应力（WSS）、体动脉血氧饱和度（Sat）、颗粒清除时间（WOT）、右上腔静脉压力（P）、肺血流分布（PFD）和肝血流分布（HFD），以评估APBF的血流动力学效应。
结果表明，APBF可改善iPL和Sat，但会使P和心脏负荷变差，并对HFD产生较大影响，使肝血流更容易灌注到无主肺动脉和APBF的一侧。APBF速率的增加还能有效导致更大的血流搏动、区域速度和壁面剪应力，并降低WOT，这种效应可能对永存左上腔静脉（PLSVC）患者更有效。然而，APBF对PFD可能影响较小。此外，APBF对WOT、iPL和HFD的影响可能比对P的影响更显著，并且对iPL和WOT较差的患者有更大的改善作用。
适度的APBF不仅是促进肺动脉生长和体动脉血氧饱和度的措施，也是对抗内皮功能障碍和血栓形成的有效方法。然而，适度的APBF是因人而异的，应根据导致理想患者预后的血流动力学偏好来确定，同时应注意防止P和心脏负荷过高以及HFD失衡。
