Kwakman Sanne M B, Terzano Michele, Rolf Malte, Holzapfel Gerhard A
Institute of Biomechanics, Graz University of Technology, Graz, Austria.
Department of Structural Engineering, Norwegian University of Science and Technology (NTNU), Trondheim, Norway.
Int J Numer Method Biomed Eng. 2025 Jul;41(7):e70058. doi: 10.1002/cnm.70058.
Atherosclerotic arteries exhibit geometric alterations due to plaque deposition, which often leads to luminal narrowing. Balloon angioplasty is a common and suggested treatment to restore blood flow. However, depending on balloon oversizing, rupture at the plaque shoulder or the fibrous cap may occur. The rupture risk is influenced by factors such as the geometry of the fibrous cap, the lipid pool size, and calcifications. Despite advances in clinical imaging, predicting plaque rupture remains challenging because of lesion variability. This study addresses this gap by identifying key geometrical factors that influence stress distribution during balloon angioplasty, thus improving biomechanical insights and risk assessment. In this work, we develop a parameterized cross-sectional model of the atherosclerotic artery to investigate the influence of these components on stress distribution during balloon angioplasty. This model can be adapted to different stages and geometries of atherosclerosis. The parametric model enables the evaluation of the influence of uncertain input parameters, especially geometrical parameters, on the outcome of a finite element analysis. Experimental data from a layer-specific mechanical test on an iliac artery and pressure-diameter curves from balloon inflation tests are used to calibrate the respective constitutive models. Balloon angioplasty is then simulated by inflating a balloon in the narrowed artery without explicitly considering balloon unfolding. We perform simulations for a local sensitivity analysis by varying the six most influential geometrical parameters and leaving the remaining parameters and the material parameters unchanged. The results show that the amount of the lipid pool has the largest influence on the maximum principal stress in the arterial tissue. Furthermore, the thickness of the fibrous cap plays a critical role in determining the specific location where this maximum occurs. These findings offer valuable insights into potential initiation sites of damage in atherosclerotic arteries.
动脉粥样硬化的动脉由于斑块沉积而呈现几何形状改变，这通常会导致管腔狭窄。球囊血管成形术是一种恢复血流的常见且推荐的治疗方法。然而，根据球囊扩张程度，斑块肩部或纤维帽可能会发生破裂。破裂风险受纤维帽几何形状、脂质池大小和钙化等因素影响。尽管临床成像技术有所进步，但由于病变的变异性，预测斑块破裂仍然具有挑战性。本研究通过识别影响球囊血管成形术期间应力分布的关键几何因素来填补这一空白，从而改善生物力学见解和风险评估。在这项工作中，我们开发了动脉粥样硬化动脉的参数化横截面模型，以研究这些组件对球囊血管成形术期间应力分布的影响。该模型可适应动脉粥样硬化的不同阶段和几何形状。参数化模型能够评估不确定输入参数，尤其是几何参数，对有限元分析结果的影响。来自髂动脉层特异性力学测试的实验数据和球囊膨胀测试的压力 - 直径曲线用于校准各自的本构模型。然后通过在狭窄动脉中膨胀球囊来模拟球囊血管成形术，而不明确考虑球囊展开。我们通过改变六个最具影响力的几何参数并保持其余参数和材料参数不变来进行局部敏感性分析模拟。结果表明，脂质池的大小对动脉组织中的最大主应力影响最大。此外，纤维帽的厚度在确定该最大值出现的特定位置方面起着关键作用。这些发现为动脉粥样硬化动脉潜在损伤起始部位提供了有价值的见解。
