The effects of the pulsatile period on the size of recirculation bubble in the vicinity of stent struts

[摘要] Incomplete stent apposition (ISA) is sometimes found in stent deployment at complex lesions, and it is considered to be one of the causes of post-stenting complications, such as late stent thrombosis and restenosis. The presence of ISA leads to large recirculation bubbles behind the stent struts, which can reduce shear stress at the arterial wall that retards neointimal formation process and thus lead to complications. Computational fluid dynamics (CFD) simulations are performed on simplified two-dimensional axisymmetric arterial models with stents struts of square and circular cross-sectional shapes at a malapposition distance of 120 μm from the arterial wall. To investigate the effects of pulsatile flow period on the dynamics of the recirculation bubbles, high fidelity simulations are carried out with pulsatile flows of period 0.4 s and 0.8 s. Under the condition of the same flow rate, both square and circular strut cases show that shorter period provides greater flow deceleration, leading to the formation of a larger recirculation bubble. With the same thickness, circular strut has a significant improvement over the square strut in terms of the size of the recirculation bubble, and therefore less likely to lead to complications.

[发布机构] Department of Mechanical Engineering, Melbourne School of Engineering, University of Melbourne, VIC; 3010, Australia^1;Department of Medicine, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, VIC; 3010, Australia^2

[效力级别] 力学 [学科分类] 力学，机械学

[关键词] Arterial model;Arterial wall;Computational fluid dynamics simulations;Cross-sectional shape;High-fidelity simulations;Neointimal formation;Recirculation bubbles;Stent deployments