法洛四联症根治术后对左肺动脉狭窄影响机理的数值分析

目的 利用计算流体力学(CFD)方法分析法洛四联症(TOF)根治术后不同的左肺动脉狭窄率（50%，20%，0%）模型的局部血流动力学改变。方法 通过对患者CT数据处理，完成3组左肺肺动脉狭窄几何的全三维数字化重构；结合主肺动脉血流量等临床数据，对3组模型中肺动脉分叉区的血液流动速度场、压力、壁面剪切应力等进行记录。结果 在3组模型的非定常模拟中，左肺动脉起始端均存在与狭窄率相关的反流和血流分布，右肺动脉血流分布规则。3组模型的静态压力、压力损失、壁面剪切力等也不同。结论 肺动脉分支的合理扩大在TOF根治术中有重要意义；术后左肺动脉狭窄是造成肺动脉反流的早期和重要因素；通过CFD模拟术后患者的三维模型可以对手术的效果提供早期参考。

Numerical analysis on the mechanism causing the left pulmonary artery stenosis after repair by tetralogy of fallot

Objective To investigate the influence from the left pulmonary artery (LPA) with different stenosises (50%,20%,0%) after complete repair of tetralogy of fallot (TOF) on the hemodynamic features using computational fluid dynamics(CFD). Method The 3D models were reconstructed by the computer tomography (CT) images. CFD simulations were performed on these three models to describe the flow characteristics of the main pulmonary artery and the bifurcations such as average speed in LPA and right pulmonary artery(RPA), flow patterns, static pressure and wall shear stress. Results In the unsteady state simulation, different regurgitation and flow velocity distribution can be easily found in the start of LPA due to the stenosis rate of LPA, while the flow velocity distribution is uniform in the RPA. The flow velocity distribution, static pressure, pressure drop and wall shear stress are also different in these three models. Conclusions It is important to expand the branch pulmonary arteries during the TOF operation. LPA stenosis may be an early and important cause of pulmonary artery regurgitation. The use of CFD simulation can provide the early reference information for the effect after TOF operation.