Innovating stents for aneurysm repair: New implant designs informed by thrombosis modeling.

Abstract

<h4>Background and objective</h4>Effective exclusion of aortic aneurysms via endovascular aneurysm repair (EVAR) remains a major clinical challenge. Conventional stent-graft strategies often struggle to balance thrombus formation within the aneurysm sac with preservation of blood flow in adjacent branch vessels. This study aimed to develop a CFD-based multi-component thrombosis model to quantify how overlapping low-mesh-porosity and the new covered stents modulate hemodynamics and thrombus formation in thoracic aortic aneurysms.<h4>Methods</h4>This study employed computational fluid dynamics (CFD) to develop a multi-component thrombosis model within a simplified thoracic aortic aneurysm. Different stent configurations, including single-layer, double-layer overlapping, and partially covered double-layer low-mesh-porosity stents, were deployed to assess their impact on hemodynamic parameters such as blood flow velocity, wall shear stress (WSS), time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), and relative residence time (RRT). Activated platelet distributions were also analyzed to evaluate thrombus formation potential.<h4>Results</h4>Overlapping stents significantly reduced blood flow velocity and WSS near the aneurysm wall while enhancing platelet activation, thereby creating favorable conditions for stable thrombus formation and effective aneurysm exclusion. Partially covered stents further optimized hemodynamics by restricting high-speed blood flow without impeding blood flow in adjacent branches, resulting in greater reductions in TAWSS and OSI and substantial increases in RRT and platelet activation.<h4>Conclusion</h4>Overlapping low-mesh-porosity stents, particularly partially covered designs, offer a superior hemodynamic environment for thrombus formation and aneurysm stabilization. These findings support the optimization of endovascular repair strategies and inform the design of novel implant technologies. Future studies should focus on in vivo validation and patient-specific modeling to advance personalized aneurysm management.