Flexibility of Biodegradable Polymer Stents with Different Strut Geometries

Abstract

Objective: Biodegradable stents (BDSs) represent a new technological development in the field of cardiovascular angioplasty; good flexibility helps stents pass through tortuous vessels during delivery and reduces the amount of damage caused to blood vessels. This study investigates the relationship between flexibility and the geometry of BDS struts. Methods: Four stent struts with different geometry (circular, triangular, hexagonal, and spline curved) and the same links were modeled to evaluate their flexibility via a three-point bending experimental method and a numerical method. Results: The bending state of the four stents was well-balanced. The bending effect of the four stents was different. Under the same conditions, the circular and spline curved stents showed the best bending effects while the hexagonal stent was the worst. However, these differences were not significant. Conclusion: The flexibility of BDSs is related to the geometry of the struts and links; however, the geometry of the struts has less effect on flexibility than the links. The greater the area enclosed by the strut centerline, the better flexibility of the stent.

3D Printing of Polymeric Bioresorbable Stents: A Strategy to Improve Both Cellular Compatibility and Mechanical Properties

“…Before implantation, the vascular stent must have enough flexibility to pass inside the blood vessels during delivery, maintaining the shape and the design. Once placed in the artery, the flexibility of the device must be taken into consideration since the vascular stent must have the capacity to bend to be well fitted to the blood vessel [ 26 ]. Additionally, it should resist compression from the arteries during the systolic and diastolic movements [ 23 ].…”

Laser powder bed fusion of diatom frustule inspired bionic NiTi lattice structures: compressive behavior and shape memory effect

“…In addition, with the increase in strut curvature, the buckling load of the component was significantly reduced. Chen et al [46] compared the deformation behavior of stents composed of curved struts and straight struts via bending experiments, and the results showed that the curved-strut-based component performed high flexibility than that of the straight-strut-based component.…”

Regularity of a Parabolic Differential Equation on Graphs

“…There are some researchers that investigate the properties of partial differential equations defined on graphs, like in reference [7], but for observing such boundary value problems here, we find motivation in modelling mesh-like structures, like biodegradable stents. A biodegradable stent is a mesh that is used to treat the narrow or closed part of the artery to open and restore normal blood flow, which is made of a biodegradable material [8][9][10] (see Figure 1, left). However, since struts in the stent are thin, a simple structure model, called the onedimensional curved rod model, can be used (see reference [11]).…”