计算机辅助分析腔内外肺动脉环缩术血流动力学初探

Computer-aided analysis of hemodynamic study in intraluminal and extraluminal pulmonary artery banding

目的利用计算流体力学方法探索肺动脉环缩术(PAB)中腔外环缩术(E-PAB)和腔内环缩术(I-PAB)间血流动力学差异。方法纳入2020年上海交通大学医学院附属上海儿童医学中心1例需行PAB手术患儿,基于医学影像数据三维建模,利用计算机辅助设计分别行E-PAB和I-PAB虚拟手术,通过计算流体动力学分析比较术后肺动脉血流动力学参数差异。结果与E-PAB相比,I-PAB术后环缩部位附近有更多湍流形成,该处附近压力变化明显,壁面剪切力较高,可达133Pa。I-PAB术后总能量损失(0.18W)远高于E-PAB(0.05W),能量效率32.61%,约为E-PAB的一半。结论E-PAB在控制压力负荷,减轻心脏负担更具优势。不同环缩方式造成肺动脉几何形态差异是导致血流动力学表现不同的主要因素,计算流体动力学结合计算机辅助设计是术前手术规划和术后血流动力学预测的一种新型工具。

Objective To investigate the hemodynamic differences between extraluminal pulmonary artery banding(E-PAB)and intraluminal pulmonary artery banding(I-PAB).Methods In 2020,A patient required PAB in Shanghai Children’s Medical Center affiliated to Shanghai Jiao Tong University School of Medicine was included and the patient-specific three-dimensional pulmonary artery model was reconstructed.Virtual surgeries of E-PAB and I-PAB were performed through computer-aided design(CAD).Computational fluid dynamice(CFD)was utilized to analyze the differences of postoperative hemodynamic parameters.Results Compared with the EPAB model,the flow field nearby the banding site in the I-PAB model presented with more turbulence.The pressure drop of that area was obvious,and wall shear stress was higher in the I-PAB model,up to 133 Pa.The energy loss of I-PAB(0.18 W)was higher than that of E-PAB(0.05 W).The energy efficiency of I-PAB was32.61%,approximately half of the E-PAB’s.Conclusion E-PAB is better in controlling pulmonary artery pressure and reducing the cardiac burden.The different hemodynamic performances were rooted in different morphology of pulmonary artery caused by various surgery design of PAB.CFD combined with CAD is an effective tool for preoperative surgical planning and postoperative hemodynamic prediction.