Javadi Elahe, Laudenschlager Sebastian, Kheyfets Vitaly, Di Maria Michael, Stone Matthew, Jamali Safa, Powell Andrew J, Moghari Mehdi H
Mechanical and Industrial Engineering Department, Northeastern University, Boston, MA, USA.
School of Medicine, University of Colorado Aurora, and Department of Radiology, Children's Hospital Colorado, Aurora, CO, USA.
J Clin Images Med Case Rep. 2022 Jun;3(6). doi: 10.52768/2766-7820/1916. Epub 2022 Jun 29.
Single ventricle hearts have only one ventricle that can pump blood effectively and the treatment requires three stages of operations to reconfigure the heart and circulatory system. At the second stage, Glenn procedure is performed to connect superior vena cava (SVC) to the pulmonary arteries (PA). For the third and most complex operation, called Fontan, an extracardiac conduit is used to connect inferior vena cava (IVC) to the PL and thereafter no deoxygenated blood goes to the heart. Predicting Hemodynamic Performance of Fontan Operation using computational fluid dynamics (CFD) is hypothesized to improve outcomes and optimize this treatment planning in children with single-ventricle heart disease. An important reason for this surgical planning is to reduce the development of pulmonary arteriovenous malformations (PAVM) and the need to perform Fontan revisions. The purpose of this study was to develop amodel for Fontan surgical planning and use this model to compare blood circulation in two designed graft types of Fontan operation known as T-shape and Y-graft. The functionality of grafts was compared in terms of power loss (PL) and hepatic flow distribution (HFD), a known factor in PAVM development. To perform this study, ten single-ventricle children with Glenn physiology were included and a CFD model was developed to estimate the blood flow circulation to the left and right pulmonary arteries. The estimated blood flow by CFD was compared with that measured by cardiovascular magnetic resonance. Results showed that there was an excellent agreement between the net blood flow in the right and left pulmonary arteries computed by CFD and CMR (ICC= 0.98, P-value ≥0.21). After validating the accuracy of each CFD model, Fontan operations using T-shape and Y-graft conduits were performed for each patient and the developed CFD model was used to predict the post-surgical PL and HFD. We found that the PL in the Y-graft was significantly lower than in the T-shape (P-value ≤0.001) and HFD was significantly better balanced in Y-graft compared to the T-shape (P-value=0.004).
单心室心脏只有一个能够有效泵血的心室，其治疗需要三个阶段的手术来重新构建心脏和循环系统。在第二阶段，进行格林手术，将上腔静脉（SVC）与肺动脉（PA）相连。对于第三个也是最复杂的手术，即方坦手术，使用心外管道将下腔静脉（IVC）与肺动脉相连，此后脱氧血液不再进入心脏。假设使用计算流体动力学（CFD）预测方坦手术的血流动力学性能可改善单心室心脏病患儿的治疗结果并优化治疗方案。这种手术规划的一个重要原因是减少肺动静脉畸形（PAVM）的发生以及进行方坦手术修正的必要性。本研究的目的是开发一种用于方坦手术规划的模型，并使用该模型比较两种设计的方坦手术移植物类型（T形和Y形移植物）中的血液循环。根据功率损失（PL）和肝血流分布（HFD）（PAVM发生的一个已知因素）对方形移植物的功能进行了比较。为进行这项研究，纳入了10名具有格林生理特征的单心室儿童，并开发了一个CFD模型来估计流向左右肺动脉的血流循环。将CFD估计的血流与心血管磁共振测量的血流进行比较。结果表明，CFD和CMR计算的左右肺动脉净血流之间存在极好的一致性（ICC = 0.98，P值≥0.21）。在验证每个CFD模型的准确性之后，为每位患者进行了使用T形和Y形移植物管道的方坦手术，并使用开发的CFD模型预测术后的PL和HFD。我们发现Y形移植物中的PL显著低于T形移植物（P值≤0.001），并且与T形移植物相比，Y形移植物中的HFD平衡明显更好（P值 = 0.004）。
