Department of Thoracic and Cardiovascular Surgery, Shanghai Children's Medical Center, Shanghai Jiaotong University School of Medicine, Shanghai, China.
Department of Electrical & Computer Engineering, Sun Yat-sen University - Carnegie Mellon University Joint Institute of Engineering, Pittsburgh, Pennsylvania; QuantMD, LLC, Pittsburgh, Pennsylvania.
Ann Thorac Surg. 2013 Oct;96(4):1398-1404. doi: 10.1016/j.athoracsur.2013.05.035. Epub 2013 Jul 30.
Appropriate choice of Fontan pathway requires keen preoperative examination of angiographic anatomy. We hypothesize that surgical choices may be better informed by lessons learned from postoperative hemodynamic evaluation in different Fontan connection strategies.
High-performance computational fluid dynamics is employed to evaluate hemodynamics in five unique Fontan anatomies. Our cohort included one lateral tunnel, extracardiac conduit, intraatrial conduit, intra/extracardiac conduit, and direct cavopulmonary connection (DCPC) Fontan pathway. Theoretical cardiac cycle-averaged power loss (Eloss) and hepatic flow distribution (HFD) were compared after modeling identical physiologic pulsatile caval flow and time-resolved pulmonary artery flow distribution. The Eloss was also evaluated at instants of peak inferior vena cava flow and peak superior vena cava flow to study caval anastomosis shape sensitivity on hemodynamics.
Quantitative examination of Eloss and HFD revealed minimum cycle-averaged Eloss in the extracardiac conduit Fontan; however, at the cost of the poorest HFD (left pulmonary artery/right pulmonary artery = 84.5%/15.5%). In contrast, DCPC Fontan was found to have the best trade-off between mean Eloss (5.87 mW, 2.44%) and HFD (left pulmonary artery/right pulmonary artery = 38.9%/61.1%). Except for intraatrial conduit, the instantaneous superior vena cava and inferior vena cava peak flow Eloss exceeded the cycle average Eloss. The peak inferior vena cava flow Eloss of DCPC Fontan nearly equaled its cycle-averaged Eloss (∼5.69 mW).
Considering cycle-averaged Eloss, HFD, and peak inferior vena cava flow Eloss, DCPC had the best hemodynamic performance. Intraatrial conduit Fontan is an efficient modification of lateral tunnel Fontan that offers possibility for excellent streamlining of inferior vena cava and superior vena cava with the pulmonary arteries.
合适的 Fontan 途径选择需要对血管造影解剖进行仔细的术前检查。我们假设，通过对不同 Fontan 连接策略的术后血流动力学评估中吸取经验教训，手术选择可能会得到更好的指导。
采用高性能计算流体动力学方法评估五种独特的 Fontan 解剖结构的血流动力学。我们的队列包括一个侧隧道、心外管道、心房内管道、心内外管道和直接腔静脉肺动脉连接（DCPC）Fontan 途径。在模拟相同的生理脉动性腔静脉血流和时间分辨肺动脉血流分布后，比较理论上的心脏周期平均功率损耗（Eloss）和肝血流分布（HFD）。Eloss 还在腔静脉下腔静脉流量峰值和腔静脉上腔静脉流量峰值时刻进行评估，以研究腔静脉吻合形状对血流动力学的敏感性。
Eloss 和 HFD 的定量检查显示，心外管道 Fontan 的循环平均 Eloss 最小；然而，其 HFD 最差（左肺/右肺=84.5%/15.5%）。相比之下，DCPC Fontan 在平均 Eloss（5.87mW，2.44%）和 HFD（左肺/右肺=38.9%/61.1%）之间找到了最佳的权衡。除心房内管道外，腔静脉上腔静脉和下腔静脉峰值流量的 Eloss 超过了循环平均 Eloss。DCPC Fontan 的腔静脉下腔静脉峰值流量 Eloss 几乎等于其循环平均 Eloss（约 5.69mW）。
考虑到循环平均 Eloss、HFD 和腔静脉下腔静脉峰值流量 Eloss，DCPC 的血流动力学性能最佳。心房内管道 Fontan 是侧隧道 Fontan 的有效改良，为腔静脉和上腔静脉与肺动脉的优化流线化提供了可能。
