Chidyagwai Simbarashe G, Kaplan Michael S, Jensen Christopher W, Chen James S, Chamberlain Reid C, Hill Kevin D, Barker Piers C A, Slesnick Timothy C, Randles Amanda
Department of Biomedical Engineering, Duke University, 534 Research Drive, 27708, Durham, NC, USA.
Department of Anesthesiology and Pain Medicine, University of Washington, Seattle, WA, USA.
Cardiovasc Eng Technol. 2024 Aug;15(4):431-442. doi: 10.1007/s13239-024-00724-3. Epub 2024 Mar 8.
This study created 3D CFD models of the Norwood procedure for hypoplastic left heart syndrome (HLHS) using standard angiography and echocardiogram data to investigate the impact of shunt characteristics on pulmonary artery (PA) hemodynamics. Leveraging routine clinical data offers advantages such as availability and cost-effectiveness without subjecting patients to additional invasive procedures.
Patient-specific geometries of the intrathoracic arteries of two Norwood patients were generated from biplane cineangiograms. "Virtual surgery" was then performed to simulate the hemodynamics of alternative PA shunt configurations, including shunt type (modified Blalock-Thomas-Taussig shunt (mBTTS) vs. right ventricle-to-pulmonary artery shunt (RVPAS)), shunt diameter, and pulmonary artery anastomosis angle. Left-right pulmonary flow differential, Q/Q, time-averaged wall shear stress (TAWSS), and oscillatory shear index (OSI) were evaluated.
There was strong agreement between clinically measured data and CFD model output throughout the patient-specific models. Geometries with a RVPAS tended toward more balanced left-right pulmonary flow, lower Q/Q, and greater TAWSS and OSI than models with a mBTTS. For both shunt types, larger shunts resulted in a higher Q/Q and higher TAWSS, with minimal effect on OSI. Low TAWSS areas correlated with regions of low flow and changing the PA-shunt anastomosis angle to face toward low TAWSS regions increased TAWSS.
Excellent correlation between clinically measured and CFD model data shows that 3D CFD models of HLHS Norwood can be developed using standard angiography and echocardiographic data. The CFD analysis also revealed consistent changes in PA TAWSS, flow differential, and OSI as a function of shunt characteristics.
本研究利用标准血管造影和超声心动图数据创建了用于左心发育不全综合征（HLHS）的诺伍德手术的三维计算流体动力学（CFD）模型，以研究分流特性对肺动脉（PA）血流动力学的影响。利用常规临床数据具有诸如可获得性和成本效益等优势，而无需让患者接受额外的侵入性手术。
从双平面电影血管造影生成两名接受诺伍德手术患者的胸内动脉的个体化几何模型。然后进行“虚拟手术”以模拟替代肺动脉分流配置的血流动力学，包括分流类型（改良布莱洛克-托马斯-陶西格分流术（mBTTS）与右心室至肺动脉分流术（RVPAS））、分流直径和肺动脉吻合角度。评估左右肺血流差异、Q/Q、时间平均壁面切应力（TAWSS）和振荡切变指数（OSI）。
在整个个体化模型中，临床测量数据与CFD模型输出之间有很强的一致性。与采用mBTTS的模型相比，采用RVPAS的几何模型往往趋向于左右肺血流更平衡、Q/Q更低、TAWSS和OSI更高。对于两种分流类型，更大的分流导致更高的Q/Q和更高的TAWSS，对OSI影响最小。低TAWSS区域与低血流区域相关，将PA-分流吻合角度改变为朝向低TAWSS区域可增加TAWSS。
临床测量数据与CFD模型数据之间的良好相关性表明，可以使用标准血管造影和超声心动图数据开发HLHS诺伍德手术的三维CFD模型。CFD分析还揭示了作为分流特性函数的PA的TAWSS、血流差异和OSI的一致变化。
