Forschungscampus STIMULATE, University of Magdeburg, Sandtorstraße 23, 39106, Magdeburg, Germany; Department of Fluid Dynamics and Technical Flows, University of Magdeburg, Universitaetsplatz 2, 39106, Magdeburg, Germany.
Forschungscampus STIMULATE, University of Magdeburg, Sandtorstraße 23, 39106, Magdeburg, Germany; Department of Neuroradiology, University Hospital Magdeburg, Leipziger Str. 44, 39120 Magdeburg, Germany.
Comput Biol Med. 2019 Aug;111:103338. doi: 10.1016/j.compbiomed.2019.103338. Epub 2019 Jun 20.
Stent-assisted coiling has become an important treatment option for intracranial aneurysms. However, studies have shown that this procedure can lead to the deformation of the local vasculature. Its effect on intra-aneurysmal hemodynamics still remains unclear.
Pre- and post-interventional image data of three representative middle cerebral artery aneurysms are considered in this study. This includes virtually deployed stents and coils. To evaluate the proportional effect of a) vessel deformation, b) stent deployment, and c) coil placement, 24 unsteady blood flow simulations were carried out focusing on the separated effects related to intra-aneurysmal hemodynamics. Four flow parameters (velocity within the aneurysm sac, aneurysm neck inflow rate, inflow concentration index, and ostium inflow area) and four shear parameters (wall shear stress, normalized wall shear stress, shear concentration index, and high shear area) were quantified.
All of the considered flow and shear parameters, except for the shear concentration index, were clearly reduced due to treatment. Coiling and stenting caused a distinct and smaller neck inflow rate, respectively, while the impact of deformation was inconsistent among the aneurysms. Overall, coiling appears to have the strongest impact on local hemodynamics.
Stent-induced vessel deformation has a clear impact on intra-aneurysmal hemodynamics. This effect is neglected by the majority of previous studies, which consider the pre-interventional state for investigating the relation of stents and hemodynamics. The findings of this pilot study suggest that while stent-assisted coiling can lead to an improved hemodynamic situation, undesired flow conditions may occur in response to treatment.
支架辅助弹簧圈栓塞术已成为颅内动脉瘤的重要治疗选择。然而，研究表明，该手术可能导致局部血管变形。其对瘤内血流动力学的影响仍不清楚。
本研究考虑了三个代表性大脑中动脉动脉瘤的介入前后影像数据，包括虚拟放置的支架和弹簧圈。为了评估 a）血管变形、b）支架放置和 c）线圈放置的比例效应，针对与瘤内血流动力学相关的分离效应，进行了 24 次非稳态血流模拟。量化了四个血流参数（瘤腔内的速度、瘤颈流入率、流入集中指数和口流入面积）和四个剪切参数（壁面剪切应力、归一化壁面剪切应力、剪切集中指数和高剪切面积）。
除了剪切集中指数外，所有考虑的血流和剪切参数在治疗后均明显降低。弹簧圈和支架分别导致明显且较小的瘤颈流入率，而变形的影响在动脉瘤之间不一致。总体而言，弹簧圈似乎对局部血流动力学有最强的影响。
支架诱导的血管变形对瘤内血流动力学有明显影响。这一效应被大多数先前的研究忽略了，这些研究考虑了介入前的状态来研究支架与血流动力学的关系。这项初步研究的结果表明，虽然支架辅助弹簧圈栓塞术可以改善血流动力学状况，但治疗后可能会出现不理想的血流条件。
