Fontan循环不同开窗形状的血流动力学计算模拟研究

The computational hemodynamic analysis of Fontan circulation with different fenestration shapes

目的探究不同开窗形状对于全腔肺动脉连接术(total cavo-pulmonary connection,TCPC)循环血流动力学的影响。方法利用术后患儿的影像学资料重建TCPC三维模型,在面积相等的情况下分别设计圆形、正方形、椭圆形和菱形四种不同形状的开窗。以临床测量的血流动力学参数为依据设定边界条件,应用计算流体力学(computational fluid dynamics,CFD)技术分别对无开窗以及四种不同形状开窗下的血流进行模拟。结果菱形开窗的平均壁面剪切力最低,为2.1 Pa,圆形开窗时最高,为2.7 Pa;菱形开窗的整体TCPC循环能量损失也最低,为10.94 mW,而圆形开窗最高,为13.69 mW;不同形状开窗下窗口分流量和中心静脉压等参数差异较小。结论在面积相同的情况下,不同的开窗形状下TCPC区域的平均壁面剪切力和能量消耗均有所不同。

Objective To investigate the influence of different fenestration shapes on the hemodynamics in Fontan circulation.Methods Patient-specific 3-dimensional TCPC geometry was reconstructed based on the medical imaging data.Four kinds of fenestration shapes(circle,square,ellipse and diamond)were designed respectively on the three-dimensional model at the same cross-sectional area.Computational fluid dynamics simulations were performed to simulate the blood flow using physiological hemodynamic data as boundary conditions.Results The averaged wall shear stress of the diamond-shaped fenestration in the TCPC region was the lowest,which was 2.1 Pa,while the circular fenestration shows the highest averaged wall shear stress,which was 2.7 Pa.The total energy loss in the TCPC area with diamond-shaped fenestration was also the lowest,which was 10.94 mW.On the contrary,energy loss in the model with circular fenestration was the highest,which was13.69 mW.The shunt volume and the decline of central venous pressure in different models were similar.Conclusion At the same cross-sectional area,the averaged wall shear stress,as well as the total energy loss,is influenced by the shape of the fenestration in the TCPC area.