IEEE Trans Biomed Eng. 2019 Dec;66(12):3411-3419. doi: 10.1109/TBME.2019.2904885. Epub 2019 Mar 13.
Computational hemodynamic studies of aortic dissections usually combine patient-specific geometries with idealized or generic boundary conditions. In this study, we present a comprehensive methodology for the simulation of hemodynamics in type B aortic dissection (TBAD), based on fully patient-specific boundary conditions.
Pre-operative four-dimensional (4-D) flow magnetic resonance imaging (MRI) and Doppler-wire pressure measurements (pre- and post-operative) were acquired from a TBAD patient. These data were used to derive boundary conditions for computational modeling of flow before and after thoracic endovascular repair (TEVAR). Validations of the computational results were performed by comparing predicted flow patterns with pre-TEVAR 4-D flow MRI, as well as pressures with in vivo measurements.
Comparison of instantaneous velocity streamlines showed a good qualitative agreement with 4-D flow MRI. Quantitative comparison of predicted pressures with pressure measurements revealed a maximum difference of 11 mmHg (-9.7%). Furthermore, our model correctly predicted the reduction of true lumen pressure from 74/115 mmHg pre-TEVAR to 64/107 mmHg post-TEVAR (diastolic/systolic pressures at entry tear level), compared to the corresponding measurements of 72/118 mmHg and 64/114 mmHg. This demonstrates that pre-TEVAR 4D flow MRI can be used to tune boundary conditions for post-TEVAR hemodynamic analyses.
主动脉夹层的计算血流动力学研究通常将患者特定的几何形状与理想化或通用的边界条件相结合。本研究提出了一种基于完全患者特定边界条件的 B 型主动脉夹层（TBAD）血流动力学模拟的综合方法。
从一位 TBAD 患者获得术前四维（4-D）血流磁共振成像（MRI）和多普勒导丝压力测量（术前和术后）。这些数据用于在胸主动脉腔内修复术（TEVAR）前后的计算模型中推导血流的边界条件。通过将预测的血流模式与术前 4-D 血流 MRI 以及与体内测量的压力进行比较，对计算结果进行了验证。
瞬时速度流线的比较显示出与 4-D 流动 MRI 的良好定性一致性。与压力测量相比，预测压力的定量比较显示最大差异为 11mmHg（-9.7%）。此外，与相应的 72/118mmHg 和 64/114mmHg 的测量值相比，我们的模型正确预测了真腔压力从 TEVAR 术前的 74/115mmHg 降低至 TEVAR 术后的 64/107mmHg（入口撕裂水平的舒张/收缩压）。这表明术前 4D 流动 MRI 可用于调整 TEVAR 后血流动力学分析的边界条件。
