Department of Experimental Biomedicine and Clinical Neurosciences, School of Medicine, Postgraduate Residency Program in Neurological Surgery, Neurosurgical Clinic, AOUP "Paolo Giaccone", 90100 Palermo, Italy.
Dipartimento di Ingegneria Civile, dell'Energia, dell'Ambiente, e dei Material, Università degli Studi "Mediterranea" di Reggio Calabria, Via Graziella-Vito, 89122 Reggio Calabria, RC, Italy.
Clin Biomech (Bristol). 2021 Jan;81:105184. doi: 10.1016/j.clinbiomech.2020.105184. Epub 2020 Dec 5.
The pathophysiology of cerebral aneurysm is complex and poorly understood, and it can have the most catastrophic clinical presentation. Flow dynamics is a key player in the initiation and progression of aneurysm. Better understanding the interaction between hemodynamic loading and biomechanical wall responses can help to add the missing piece on aneurysmal pathophysiology. In this laboratory study we aimed to analyze the effect of the application of a mechanical force to cerebral arterial walls.
Displacement control tests were performed on five porcine cerebral arteries. The test machine was the T150 Nanotensile. The stiffness variation with the increment of the strain level is modeled as the outcome of an isotropic hyperelastic material model.
Through the application of an axial force we obtained Stress/Strain curves that showed a marked isotropic hyperelastic behavior, characterized by an increasing of stiffness with the level of strain. This behavior of the cerebral arterial wall is different from the well-established behavior of other arterial vessel (as the aortic vessel) characterized by a marked anisotropic behavior. Additionally, the data scattering observed for higher values of the applied stress are related to different individual packing of collagen fibers that represent the load-bearing mechanics at higher level of the strain.
The data obtained by test in this paper represent a first step in our ongoing research about the mechanics of multi-axial loads on cerebral arterial walls, and in producing more comprehensive patient-specific calculations for potential applications on cerebral aneurysm management.
脑动脉瘤的病理生理学复杂且尚未被充分理解，其临床表现可能最为灾难性。血流动力学是动脉瘤发生和进展的关键因素。更好地理解血流动力学负荷与生物力学壁响应之间的相互作用，可以帮助我们了解动脉瘤病理生理学中缺失的部分。在这项实验室研究中，我们旨在分析向脑动脉壁施加机械力的效果。
对五根猪脑动脉进行了位移控制测试。试验机为 T150 纳米拉伸机。应变水平增量与刚度变化的关系模型为各向同性超弹性材料模型的结果。
通过施加轴向力，我们获得了应力/应变曲线，显示出明显的各向同性超弹性行为，其特征是随着应变水平的增加而增加刚度。这种脑动脉壁的行为与其他动脉（如主动脉）的既定行为不同，后者具有明显的各向异性行为。此外，在施加的应力较高时观察到的数据分散与不同的单个胶原纤维包装有关，这些纤维包装代表了在较高应变水平下的承载力学。
本文试验中获得的数据代表了我们正在进行的关于多轴向负荷对脑动脉壁力学的研究的第一步，并且为潜在应用于脑动脉瘤管理的更全面的患者特定计算提供了基础。
