Paz C, Suárez E, Cabarcos A, Pinto S I S
CINTECX, University of Vigo, Campus Universitario Lagoas-Marcosende, Vigo 36310, España.
Engineering Faculty of University of Porto, Institute of Science and Innovation in Mechanical and Industrial Engineering (LAETA-INEGI), Rua Dr. Roberto Frias, Porto 4200-465, Portugal.
Comput Methods Programs Biomed. 2021 Jul;206:106148. doi: 10.1016/j.cmpb.2021.106148. Epub 2021 May 4.
The attainment of a methodology to simulate the hemodynamic in patient-specific cerebral vessels with aneurysms is still a challenge. The novelty of this work is focused on the effect of coil embolization in a realistic cerebral aneurysm, according to the vessel wall thickness and aneurysm thickness, through transient FSI simulations.
The quality of the mesh for simulations was checked with a specific mesh convergence study; and the numerical methodology was validated using numerical research data of the literature. The model was implemented in ANSYS® software. The total deformation and equivalent stress evolution in the studied cases, before and after coil embolization, were compared. More than 20 different models were employed due to different arterial wall thickness and aneurysm wall thickness combinations.
The obtained results have showed that deformation and stress values are highly influenced with the sac thickness. The thinner sac aneurysm thickness is, the greater deformation and stress are. The results after coil embolization process have highlighted that considering typical values of arterial wall thickness and aneurysm thickness 0.3 mm and 0.15 mm respectively, a deformation reduction around 50% and a stress reduction around 70% can be achieved.
The proposed methodology is a step forward in the personalized medicine, quantifying the aneurysm rupture risk reduction, and helping the medical team in the preoperative planning, or to deciding the optimal treatment.
获得一种能够模拟特定患者伴有动脉瘤的脑血管内血液动力学的方法仍然是一项挑战。这项工作的新颖之处在于，通过瞬态流固耦合（FSI）模拟，根据血管壁厚度和动脉瘤厚度，研究弹簧圈栓塞在实际脑动脉瘤中的效果。
通过特定的网格收敛性研究来检查模拟网格的质量；并使用文献中的数值研究数据对数值方法进行验证。该模型在ANSYS®软件中实现。比较了弹簧圈栓塞前后所研究案例中的总变形和等效应力演变情况。由于动脉壁厚度和动脉瘤壁厚度的组合不同，采用了20多种不同的模型。
所得结果表明，变形和应力值受瘤囊厚度的影响很大。瘤囊厚度越薄，变形和应力就越大。弹簧圈栓塞过程后的结果突出显示，分别考虑动脉壁厚度和动脉瘤厚度的典型值0.3毫米和0.15毫米时，变形可减少约50%，应力可减少约70%。
所提出的方法在个性化医疗方面向前迈进了一步，量化了动脉瘤破裂风险的降低，并有助于医疗团队进行术前规划或决定最佳治疗方案。
