Coronary Artery Stenting Affects Wall Shear Stress Topological Skeleton

Abstract

Despite the important advancements in the stent technology for the treatment of diseased coronary arteries, major complications still affect the post-operative long-term outcome. The stent-induced flow disturbances, and especially the altered wall shear stress (WSS) profile at the strut level, play an important role in the pathophysiological mechanisms leading to stent thrombosis (ST) and in-stent restenosis (ISR). In this context, the analysis of the WSS topological skeleton is gaining more and more interest by extending the current understanding of the association between local hemodynamics and vascular diseases. The present study aims to analyze the impact that a deployed coronary stent has on the WSS topological skeleton. Computational fluid dynamics simulations were performed in three stented human coronary artery geometries reconstructed from clinical images. The selected cases presented stents with different designs (i.e., two contemporary drug eluting stents and one bioresorbable scaffold) and included regions with stent malapposition or overlapping. A recently proposed Eulerian-based approach was applied to analyze the WSS topological skeleton features. The results highlighted that the presence of single or multiple stents within a coronary artery markedly impacts the WSS topological skeleton. In particular, repetitive patterns of WSS divergence were observed at the luminal surface, highlighting a WSS contraction action proximal to the struts and a WSS expansion action distal to the struts. This WSS action pattern was independent from the stent design. In conclusions, these findings could contribute to a deeper understanding of the hemodynamic-driven processes underlying ST and ISR.

Three-dimensional printing as a cutting-edge, versatile and personalizable vascular stent manufacturing procedure: Toward tailor-made medical devices

“…The implanted VS induces disturbances in blood flow and alters shear stress of wall vessels at the strut level. These factors highly influence the pathophysiological mechanisms leading to VS complications [ 81 ] . Focusing on the structural and geometrical design of VS, the first manufactured stents could be classified into slotted geometries and coil geometries.…”

Adaptation of Vascular Smooth Muscle Cell to Degradable Metal Stent Implantation

“…Stent presence definitely changes the blood flow and shear stress at the surrounding arterial wall and induces adverse tissue responses. , Additionally, triangular stents have even been demonstrated to cause regionally lower or oscillating shear stress in comparison to rectangular ones and to result in less restenosis . Indeed, stent thrombosis and in-stent restenosis have been shown to be influenced by stent-induced flow disturbances, especially by the wall shear stress profile altered at struts …”

“…54 Indeed, stent thrombosis and in-stent restenosis have been shown to be influenced by stent-induced flow disturbances, especially by the wall shear stress profile altered at struts. 56 Obviously, DMSs are expected to cast large influences on the physical conditions in their implanted vessels, since their degradation greatly transforms their physiochemical features (e.g., stiffness, elasticity, surface topography). Nonetheless, there was only one numerical simulation reported for magnesium alloy stents that predicted a nonuniform distribution of shear stress after their implantation.…”

Advancements and Opportunities in Characterizing Patient-Specific Wall Shear Stress Imposed by Coronary Artery Stenting

“…Helical flow structures can also result from any curvature upstream of the stent and in bifurcation regions [55]. Such details have since been associated with an index called the WSS topological skeleton, which is calculated from the divergence of the normalized WSS vector field and provides an additional characterization of the forces that may be experienced by cells along the stented vessel surface [106].…”