Y形心外管道Fontan手术的数值仿真与血流动力学评估

Numerical simulation and hemodynamic evaluation of Y-graft Fontan procedure

目的应用计算仿真技术,对比分析YCPC心外管道与传统TCPC心外管道的血流动力学参数及能量效率。方法基于1例诊断为SLL型先天性矫正大动脉转位(ccTGA)伴右心发育不良患者术前的CTA图像资料应用Mimics Research完成模型的初始重建,按照心外管道的连接方式分为3组不同的几何形状:A传统TCPC组,B传统YCPC组,C改良YCPC组,进行数字模型的网格划分和数值仿真,计算不同重建模型的涡流分布、平均涡流量以及能量效率等参数。结果不同空间结构的涡流分布范围未见明显差异;改良YCPC方案的涡流量无论在静息条件还是不同的运动情况下,都达最高值;在能量效率方面,传统YCPC方案的能量效率明显低于传统TCPC方案,而增加分支直径后,改良YCPC方案能量效率提升,与传统TCPC方案的能量效率接近,且虽运动负荷的加大仍可保持较高的能力效率。结论数值仿真与血流动力学模拟技术为Fontan系列手术的疗效预测提供了有效的辅助。虽然改良YCPC心外管道带来了更多的涡流量,但是由于其优化的空间构型,仍可以获得接近传统TCPC能量效率,这为临床手术的应用提供了一定的理论依据。

Objective To compare and analyze the hemodynamic parameters and energy efficiency of YCPC(Y-graft total cavopulmonary connection)and traditional TCPC(total cavopulmonary connection).Methods Based on preoperative CTA of a patient with diagnose of congenital corrected transposition of great arteries(ccTGA)with right heart dysplasia,Mimics Research was applied to complete the initial reconstruction of model,and there are three groups of different geometric shapes according to the connection mode of extracardiac conduit:Group A:traditional TCPC,Group B traditional YCPC,Group C improved YCPC.Then,the grid division and numerical simulation of the digital model are carried out to calculate the turbulence distribution,average vorticity,energy efficiency and other parameters of different reconstruction models.Results There was no significant difference in the distribution range of turbulence in different digital model;The average vorticity of the improved YCPC reached the highest value in both resting conditions and different motion conditions;The energy efficiency of the traditional YCPC was significantly lower than that of the traditional TCPC,while that of the improved YCPC was improved and similar with traditional TCPC.The efficiency could still be maintained with the increase of exercise load.Conclusion Numerical and hemodynamics simulation technology provide an effective assistant for the prediction of outcome of Fontan procedures.Although the improved YCPC has brought more vortices,the energy efficiency was similar with traditional TCPC due to its optimized spatial configuration,which provides a theoretical basis for clinical application.