The impact of stenting on hemodynamic environment of tortuous coronary artery: results derived from a numerical...

Stent implantation in vessels with moderate/severe coronary tortuosity is associated with increased rates of target vessel failure due to higher rates of target vessel-related myocardial infarction or ischemia-driven target vessel revascularization. Local wall shear stress (WSS) changes might contribute to this phenomenon. This study investigates the impact of stenting on the hemodynamic environment of tortuous coronary arteries in a numerical simulation model.

A numerical simulation model was established to explore the characteristics of hemodynamic parameters before and after simulated stent implantation in tortuous coronary vessels. The numerical simulation model is composed of four tortuous arcs. By controlling the curvature of these arcs, three groups with different tortuosity were formed. Four different stenosis degrees (40%, 50%, 60%, and 70%) were formed by changing the diameter of the third arc in each group. Finally, 12 models with different degrees of stenosis and tortuosity were analyzed.

The velocity and WSS were reduced in proportion to increased stenosis after stent implantation in tortuous segments mimicking tortuous coronary vessels with low, medium, and high tortuosity.

Our results indicate that further reduced WSS in tortuous coronary vessels post stenting might lead to increased endothelial dysfunction, vascular inflammation, and neointimal hyperplasia, all of which facilitate the formation of in-stent restenosis, especially in tortuous coronary vessels with severe stenosis.