A monolithic, fully coupled fluid‐structure interaction (FSI) computational framework was developed to account for dissection flap motion in acute type B aortic dissection (TBAD). Analysis of results included wall deformation, pressure, flow, wall shear stress (WSS), von Mises stress and comparison of hemodynamics between rigid wall and FSI models. Our FSI model mimicked realistic wall deformation that resulted in maximum compression of the distal true lumen (TL) by 21.4%. The substantial movement of intimal flap mostly affected flow conditions in the false lumen (FL). Flap motion facilitated more flow entering the FL at peak systole, with the TL to FL flow split changing from 88:12 in the rigid model to 83:17 in the FSI model. There was more disturbed flow in the FL during systole (5.8% FSI vs 5.2% rigid) and diastole (13.5% FSI vs 9.8% rigid), via a λ₂ ‐criterion. The flap‐induced disturbed flow near the tears in the FSI model caused an increase of local WSS by up to 70.0% during diastole. This resulted in a significant reduction in the size of low time‐averaged WSS (TAWSS) regions in the FL (113.11 cm² FSI vs 177.44 cm² rigid). Moreover, the FSI model predicted lower systolic pressure, higher diastolic pressure, and hence lower pulse pressure. Our results provided new insights into the possible impact of flap motion on flow in aortic dissections, which are particularly important when evaluating hemodynamics of acute TBAD.

中文翻译：

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通过使用流固耦合，内膜瓣运动对急性 B 型主动脉夹层血流的影响。

开发了一个整体的、完全耦合的流固耦合 (FSI) 计算框架来解释急性 B 型主动脉夹层 (TBAD) 中的夹层瓣运动。结果分析包括壁变形、压力、流量、壁剪切应力 (WSS)、von Mises 应力以及刚性壁和 FSI 模型之间的血流动力学比较。我们的 FSI 模型模拟了真实的壁变形，导致远端真腔 (TL) 最大压缩 21.4%。内膜瓣的大量移动主要影响假腔 (FL) 中的流动条件。皮瓣运动促进了更多的血流在收缩期峰值进入 FL，TL 到 FL 的血流分流从刚性模型中的 88:12 变为 FSI 模型中的 83:17。在收缩期（5.8% FSI vs 5.2% 刚性）和舒张期（13.5% FSI vs 9.8% 刚性）期间，FL 中的血流紊乱更多，λ _{2 -}标准。FSI 模型中撕裂处附近皮瓣引起的扰动导致舒张期局部 WSS 增加高达 70.0%。这导致 FL 中低时间平均 WSS (TAWSS) 区域的大小显着减小（113.11 cm ² FSI vs 177.44 cm ²刚性）。此外，FSI 模型预测较低的收缩压、较高的舒张压，从而降低脉压。我们的研究结果为皮瓣运动对主动脉夹层血流的可能影响提供了新的见解，这在评估急性 TBAD 的血流动力学时尤为重要。