Aortic dissection (AD) is one of the most catastrophic cardiovascular diseases. AD occurs when a layer inside the aorta is disrupted and gives rise to the formation of a true lumen and a false lumen. These lumens can be connected through tears in the intimal flap which are known as entries. Despite being known for about two centuries, the effects of many factors on the morbidity and mortality of this disease are still unknown. As the blood interaction with the aorta is crucial in the severity and the progression of the aortic dissection, a biomechanical approach is chosen to investigate the influence of different morphologies on the severity of this disease. Using the finite element method (FEM) and the fluid–structure interaction (FSI) approach, we have evaluated the blood flow characteristics along the diseased aorta, in conjunction with the deformation of the aortic wall. In this study, an idealized geometry of a dissected descending aorta (type B) with two entries has been studied. The values for the diameter of the entry tear were chosen to be 5 mm and 10 mm. Therefore, a total of four conditions were investigated. According to our results, the retrograde flow through the proximal tear is dependent on the size of the distal re-entry and vice versa. Our results revealed that when both entry and re-entry tears are 10 mm in diameter, the flow passes through the true and false lumens with smaller resistance, resulting in a smaller flutter of the intimal flap, and therefore more stable intimal flap. Major oscillation frequencies of 2.5 Hz and 7.4 Hz were observed for the oscillation of the intimal flap, and amplitudes of the waves with higher frequencies were negligible.

主动脉夹层（AD）是最具灾难性的心血管疾病之一。当主动脉内的一层被破坏并导致真腔和假腔的形成时，就会发生 AD。这些管腔可以通过内膜瓣中的撕裂（称为入口）连接。尽管已经知道了大约两个世纪，但许多因素对这种疾病的发病率和死亡率的影响仍然未知。由于血液与主动脉的相互作用对主动脉夹层的严重程度和进展至关重要，因此选择生物力学方法来研究不同形态对这种疾病严重程度的影响。使用有限元方法 (FEM) 和流固耦合 (FSI) 方法，我们评估了沿患病主动脉的血流特性，结合主动脉壁的变形。在这项研究中，研究了具有两个条目的解剖降主动脉（B 型）的理想几何形状。入口撕裂直径的值选择为 5 毫米和 10 毫米。因此，总共研究了四个条件。根据我们的结果，通过近端撕裂的逆流取决于远端再入的大小，反之亦然。我们的研究结果表明，当进入和再进入撕裂直径为10 mm时，流经真假腔阻力较小，导致内膜瓣的颤动较小，因此内膜瓣更稳定。对于内膜瓣的振荡，观察到 2.5 Hz 和 7.4 Hz 的主要振荡频率，