Proof of concept study for radial compression strength & shape memory effect of 3D printed double arrowhead PLA stent

Self-expanding biodegradable stents are expected to replace metallic stents in the treatment of peripheral artery disease, which may cause numerous problems to human health. Since the materials used in polymeric-based stents are more suited to human cells, they are considered the next generation of these medical devices. The fabrication of polymeric stents with optimized parametric 3D printing settings can surely improve their mechanical performance including radial strength which is considered as one of the crucial factors for the efficient functioning of the stent. The radial supporting capability of the stent should be taken into consideration by the vessel to restore the patency of blocked peripheral arteries with varying characteristics and functions. In this work, a double arrowhead 3D-printed PLA stent's distinct mechanical properties are developed and described. The fused deposition modeling mechanism of 3D printing was used to manufacture the double arrowhead stent specimens to analyze the radial strength. For the analysis of Stents with different sets of geometric parameters (outer diameter, height of stent, strut diameters, width of strut) were developed. The results demonstrate that for the same set of other dimensional parameters, the lowest diameter stents showed the highest radial strength in the experiments also it is evident that when strut diameter increases along with the angle between the axial direction and support strut (phi), and the angle between the axial direction and re-entrant strut (theta), results increase in the support strut cross-sectional (coverage) area resulting in the increased radial strength. Another observation is that the radial recovery ratio and length recovery ratios are 91 to 95% and 92 to 98% respectively which is suitable for polymeric stent application.