Purpose

Stenting is the most common intervention for arteriosclerosis treatment; however, the success of the treatment depends on the incidence of in-stent restenosis (ISR). Stent deployment characteristics are major influencers of ISR and can be measured in terms of dogboning, asymmetry, and foreshortening. This study aimed to analyse the implications of balloon and stent-catheter assembly parameters on the stent deployment characteristics.

Methods

Experimental approach to analyse the impact of the balloon and stent-catheter assembly parameters on stent deployment characteristics is a time-consuming and complex task, whereas numerical methods prove to be quick, efficient, and reliable. In this study, eleven finite element models were employed to analyse non-uniform balloon stent expansion pattern, comprised of variation in, stent axial position on balloon, balloon length, balloon folding pattern, and balloon wall thickness.

Results

Obtained results suggest that the axially noncentral position of the stent on balloon and variable balloon thickness lead to non-uniform stent deployment pattern. Also, it was proved that variation in balloon length and balloon folding pattern influence deployment process.

Conclusion

Improved positional accuracies, uniform balloon wall thickness, and selection of the appropriate length of a balloon for selected stent configuration will help to minimize dogboning, asymmetry, and foreshortening during non-uniform stent expansion, thereby reducing the risk of restenosis. The stated numerical approach will be helpful to optimize stent catheter assembly parameters thus minimizing in-vitro tests and product development time.

中文翻译：

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Dogboning和Foreshortening驱动的球囊扩张支架展开不均匀性数值分析

目的

支架置入术是动脉硬化治疗最常见的干预措施；然而，治疗的成功取决于支架内再狭窄（ISR）的发生率。支架部署特征是 ISR 的主要影响因素，可以通过严格控制、不对称和透视缩短来衡量。本研究旨在分析球囊和支架-导管组装参数对支架展开特性的影响。

方法

分析球囊和支架导管组件参数对支架展开特性影响的实验方法是一项耗时且复杂的任务，而数值方法被证明是快速、高效和可靠的。在这项研究中，使用 11 个有限元模型来分析不均匀的球囊支架扩张模式，包括支架在球囊上的轴向位置、球囊长度、球囊折叠模式和球囊壁厚度的变化。

结果

获得的结果表明，支架在球囊上的轴向非中心位置和可变的球囊厚度导致支架部署模式不均匀。此外，还证明了气球长度和气球折叠模式的变化会影响展开过程。

结论

改进的定位精度、均匀的球囊壁厚以及为选定的支架配置选择合适的球囊长度将有助于最大限度地减少非均匀支架扩张过程中的狗骨、不对称和缩短，从而降低再狭窄的风险。所述数值方法将有助于优化支架导管组装参数，从而最大限度地减少体外测试和产品开发时间。