支架治疗主动脉弓内侧动脉瘤的仿真研究

Simulation of Stent Treatment for Aneurysms in the Inner Bend of Aortic Arch

血管内支架是治疗主动脉弓动脉瘤的一种新技术。目前还没有人对具有局部突起的动脉瘤支架治疗血流动力学进行过研究。基于这样的事实,本仿真研究对主动脉弓内侧动脉瘤的支架治疗进行血流动力学分析。为便于比较,分别建立了有支架和无支架的主动脉弓动脉瘤模型。利用计算流体力学的方法对两个模型中的生理性血液流动进行了仿真。对流动情形、压力和壁面切应力分布进行了比较和分析,以便评价血管内支架对主动脉弓动脉瘤治疗的效果。结果表明,有支架的模型和无支架的模型,在瘤腔内的流动情形具有显著的不同。有支架模型瘤腔内的流动受到明显的抑制,特别是局部突起处的压力和壁面切应力大大地减小了。这些现象使我们有理由推断,血管内支架可以促进瘤腔内血栓的形成,并能减小动脉瘤破裂的危险。

Endovascular stent is a new technique for the treatment of aortic arch aneurysms. The present simulation study of endovascular stent treatment for aneurysms in the inner bend of aortic arch is initiated by the fact that no one has ever investigated the hemodynamics of stented aortic arch aneurysm harboring a bleb. For the comparative convenience, a stented and a nonstented aortic arch aneurysm models were constructed respectively. Physiological blood flows in both models were simulated using the computational fluid dynamics method. The detailed flow patterns, pressure and wall shear stress distributions around the aneurysm of both models were compared and analyzed so as to evaluate the effectiveness of endovascular stent treatment for aortic arch aneurysms. Results showed that the stented model is attributed to substantially different intra-aneurysmal flow patterns versus the nonstented model. Flow activities within the stented aneurysmal sacs are markedly diminished, specifically the pressure and wall shear stress in the bleb were significantly decreased. These phenomena allow us to conclude that endovascular stent can promote intra-aneurysmal thrombus development and attenuating aneurysm rupture risk.