Investigation of surface topography and potential thrombogenic implications of SLM 3D-printed SS316L cardiovascular stent using hybrid post-processing

This investigation focuses on a 3D-printed SS316L stent fabricated using Selective Laser Melting (SLM) to improve surface quality through post-processing. Four conditions were investigated: heat-treatment followed by electropolishing (HT-EP), electropolishing only (EP), heat-treatment only (HT), and without heat-treatment or electropolishing, i.e., as-built (W-HT-EP). Surface roughness was evaluated using Ra, Rq, Rz, Rt, skewness (Rsk), and kurtosis (Rku) using three independently fabricated stents per condition (n = 3). The HT-EP condition exhibited the lowest roughness, with Ra = 0.498 ± 0.014 µm, Rq = 0.546 ± 0.077 µm, Rz = 2.053 ± 0.228 µm, and Rt = 2.630 ± 0.186 µm. The corresponding Rsk and Rku values were 0.664 ± 0.061 and 2.346 ± 0.110, respectively. The Ra value of HT-EP represented an 81% reduction compared with W-HT-EP and a 38.5% reduction compared with EP alone. One-way ANOVA showed statistically significant differences (p ≤ .001), with HT-EP Tukey’s HSD analysis (p < .001). SEM revealed a uniform and defect-free morphology. HT-EP provided favorable characteristics and potential to reduce surface-topography-derived Thrombogenicity Risk Index (TRI).