药物涂层球囊作为治疗狭窄动脉的微创方法已显示出有希望的结果,但是最近的动物研究表明,不均匀的涂层转移到动脉腔。体外数据表明,局部涂层转移追踪球囊和内皮之间的局部接触压力(CP)。因此,这项工作旨在通过计算机模拟研究不同的介入和器械参数如何影响在理想血管内扩张血管成形术球囊时CP的空间分布,理想血管的大小和顺应性与健康股动脉相似.建立了血管成形术球囊计算模型,考虑到纵向不均匀的壁厚,由于其形成过程,和气球的折叠过程。为了确定导致不均匀CP的条件,灵敏度有限元分析进行了比较气球工作长度的不同值,纵向变化的壁厚,气球-血管界面上的摩擦系数,血管壁刚度和厚度,和球囊血管直径比。研究结果表明,气球和血管之间的接触明显不规则,主要受球囊的展开和纵向厚度变化的影响。反映动物研究中涂层转移分布的公开数据,界面CP分布在球囊治疗部位的中间最大,同时由于展开期间特定的球囊-血管相互作用而表现出线性峰的周向图案。球囊与血管直径的高比率,较高的血管刚度,并且发现厚度显着增加了CP的幅度和空间分布,而球囊-血管界面处的较高摩擦系数进一步加剧了CP的不均匀性。对球囊设计效果的评估表明,较厚的锥形部分导致与球囊末端相互作用的区域CP减少,而总长度仅对CP产生微弱影响。一起来看,这项研究为影响球囊-组织接触不规则性的因素提供了更深入的理解,药物涂层转移均匀性和潜在临床有效性的关键步骤。
Drug-Coated Balloons have shown promising results as a minimally invasive approach to treat stenotic arteries, but recent animal studies have revealed limited, non-uniform coating transfer onto the arterial lumen. In vitro data suggested that local coating transfer tracks the local Contact Pressure (CP) between the balloon and the endothelium. Therefore, this work aimed to investigate in silico how different interventional and device parameters may affect the spatial distribution of CP during the inflation of an angioplasty balloon within idealized vessels that resemble healthy femoral arteries in size and compliance. An angioplasty balloon computational model was developed, considering longitudinal non-uniform wall thickness, due to its forming process, and the folding procedure of the balloon. To identify the conditions leading to non-uniform CP, sensitivity finite element analyses were performed comparing different values for balloon working length, longitudinally varying wall thickness, friction coefficient on the balloon-vessel interface, vessel wall stiffness and thickness, and balloon-to-vessel diameter ratio. Findings indicate a significant irregularity of contact between the balloon and the vessel, mainly affected by the balloon\'s unfolding and longitudinal thickness variation. Mirroring published data on coating transfer distribution in animal studies, the interfacial CP distribution was maximal at the middle of the balloon treatment site, while exhibiting a circumferential pattern of linear peaks as a consequence of the particular balloon-vessel interaction during unfolding. A high ratio of balloon-to-vessel diameter, higher vessel stiffness, and thickness was found to increase significantly the amplitude and spatial distribution of the CP, while a higher friction coefficient at the balloon-to-vessel interface further exacerbated the non-uniformity of CP. Evaluation of balloon design effects revealed that the thicker tapered part caused CP reduction in the areas that interacted with the extremities of the balloon, whereas total length only weakly impacted the CP. Taken together, this study offers a deeper understanding of the factors influencing the irregularity of balloon-tissue contact, a key step toward uniformity in drug-coating transfer and potential clinical effectiveness.