基于计算流体力学的主动脉夹层血流模拟研究
Study on Blood Flow Simulation of Aortic Dissection Based on Computational Fluid Dynamics

主动脉夹层(AD)是一种死亡率很高的致命性心血管疾病。目前，计算机断层扫描(CT)成像是诊断和评估主动脉疾病的主要方式，提供血管结构的详细可视化。然而，CT成像在评估主动脉内血流动力学变化方面存在局限性。最近，计算流体动力学(CFD)作为一种先进的无创技术出现，可以实现血管内血流动力学状况的可视化。这项技术为临床医生提供了对主动脉疾病更全面的了解，有助于改进诊断、治疗计划和预后评估。本研究中，先模拟了一例直管的血流，将出口压力与解析解比较，结果吻合良好，验证了数值模拟的准确性。然后，模拟了一例AD的血流，并定量和定性分析收缩期和舒张期AD的压力和壁剪切应力(WSS)。结果表明，AD真腔和假腔的压差可促进主动脉壁内膜破裂，形成夹层，过低的壁面剪切力可增强血流对主动脉壁的撕裂作用，促进夹层的形成，这为今后AD的研究和临床实践提供参考。
Aortic dissection (AD) is a fatal cardiovascular disease with a high mortality rate. Currently, computed tomography (CT) imaging is the primary modality for diagnosing and evaluating aortic diseases, providing detailed visualization of vascular structures. However, CT imaging has limitations in assessing the hemodynamic changes within the aorta. Recently, computational fluid dynamics (CFD) has emerged as an advanced noninvasive technique that enables the visualization of hemodynamic conditions within blood vessels. This technology provides clinicians with a more comprehensive understanding of aortic disease, facilitating improved diagnosis, treatment planning, and prognosis assessment. In this study, the blood flow of a straight tube was simulated first, and the outlet pressure was compared with the analytical solution. The results were in well agreement, which verified the accuracy of the numerical simulation. Then, we simulated the blood flow of an AD and analyzed the pressure and wall shear stress (WSS) during systolic and diastolic. The results suggest that the pressure difference between the true and false cavities may trigger intimal rupture and dissection formation, and low WSS may increase aortic wall tearing and promote dissection, which provides valuable insights for future research and clinical practice of AD.