Purposr

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.

Methods

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_p/Q_s, time-averaged wall shear stress (TAWSS), and oscillatory shear index (OSI) were evaluated.

Results

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_p/Q_s, and greater TAWSS and OSI than models with a mBTTS. For both shunt types, larger shunts resulted in a higher Q_p/Q_s 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.

Conclusion

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.

中文翻译：

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肺动脉剪切应力的手术调节：诺伍德手术的患者特异性 CFD 分析

目的

本研究使用标准血管造影和超声心动图数据创建了诺伍德左心发育不全综合征 (HLHS) 手术的 3D CFD 模型，以研究分流特征对肺动脉 (PA) 血流动力学的影响。利用常规临床数据可以提供可用性和成本效益等优势，而无需让患者接受额外的侵入性操作。

方法

两名诺伍德患者的胸内动脉的患者特定几何形状是通过双平面电影血管造影生成的。然后进行“虚拟手术”以模拟替代 PA 分流器配置的血流动力学，包括分流器类型（改良 Blalock-Thomas-Taussig 分流器 (mBTTS) 与右心室至肺动脉分流器 (RVPAS)）、分流器直径和分流器直径。肺动脉吻合角。评估左右肺血流差、Q _p /Q _{s 、时间平均壁剪切应力（TAWSS）和振荡剪切指数（OSI）。}

结果

在整个患者特定模型中，临床测量数据和 CFD 模型输出之间存在很强的一致性。与具有 mBTTS 的模型相比，具有 RVPAS 的几何结构倾向于更平衡的左右肺血流、更低的 Q _p /Q _s以及更大的 TAWSS 和 OSI。对于两种分流器类型，较大的分流器会导致更高的 Q _p /Q _s和更高的 TAWSS，而对 OSI 的影响最小。低 TAWSS 区域与低流量区域相关，改变 PA 分流吻合角度以面向低 TAWSS 区域会增加 TAWSS。

结论

临床测量数据和 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 Norwood 的 3D CFD 模型。CFD 分析还揭示了 PA TAWSS、流量差和 OSI 作为分流特性函数的一致变化。