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Review
. 2021 Sep 13:9:728914.
doi: 10.3389/fbioe.2021.728914. eCollection 2021.

Topological Optimization of Auxetic Coronary Stents Considering Hemodynamics

Huipeng Xue  1 , Suvash C Saha  1 , Susann Beier  2 , Nigel Jepson  3 , Zhen Luo  1
Affiliations
Review

Topological Optimization of Auxetic Coronary Stents Considering Hemodynamics

Huipeng Xue et al. Front Bioeng Biotechnol. .

Abstract

This paper is to design a new type of auxetic metamaterial-inspired structural architectures to innovate coronary stents under hemodynamics via a topological optimization method. The new architectures will low the occurrence of stent thrombosis (ST) and in-stent restenosis (ISR) associated with the mechanical factors and the adverse hemodynamics. A multiscale level-set approach with the numerical homogenization method and computational fluid dynamics is applied to implement auxetic microarchitectures and stenting structure. A homogenized effective modified fluid permeability (MFP) is proposed to efficiently connect design variables with motions of blood flow around the stent, and a Darcy-Stokes system is used to describe the coupling behavior of the stent structure and fluid. The optimization is formulated to include three objectives from different scales: MFP and auxetic property in the microscale and stenting stiffness in the macroscale. The design is numerically validated in the commercial software MATLAB and ANSYS, respectively. The simulation results show that the new design can not only supply desired auxetic behavior to benefit the deliverability and reduce incidence of the mechanical failure but also improve wall shear stress distribution to low the induced adverse hemodynamic changes. Hence, the proposed stenting architectures can help improve safety in stent implantation, to facilitate design of new generation of stents.

Keywords: auxetic metamaterials; computational fluid dynamics; coronary stents; hemodynamics; topology optimization.

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Conflict of interest statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Figures

FIGURE 1
FIGURE 1
The 3D computational domain.
FIGURE 2
FIGURE 2
The 2D design domain.
FIGURE 3
FIGURE 3
(A) 3D level set surface; 2D level set boundary.
FIGURE 4
FIGURE 4
Multi-domain of the numerical model.
FIGURE 5
FIGURE 5
The results of case 7: (A) Initial design; (B–E) Four intermediate results; (F) Final design.
FIGURE 6
FIGURE 6
The convergent history of case 7: (A) Poisson’s ratios; (B) Modified permeabilities; (C) Objective and volume fraction.
FIGURE 7
FIGURE 7
The geometry of the optimized stent.
FIGURE 8
FIGURE 8
The deformation results of the compression test: (A) Axonometric view of the radial compression test result; (B) Side view of the radial compression test result; (C) Axonometric view of the axial compression test result; (D) Side view of the axial compression test result.
FIGURE 9
FIGURE 9
The CFD model.
FIGURE 10
FIGURE 10
The streamlines of blood around the stent F-7.
FIGURE 11
FIGURE 11
The streamlines of blood around the proximal and distal struts: (A) Proximal streamlines (Axonometric view); (B) Proximal streamlines (Side view); (C) Distal streamlines (Axonometric view); (D) Distal streamlines (Side view).
FIGURE 12
FIGURE 12
The WSS distributions of the stent: (A) Covered by the stent; (B) Without the stent.
See this image and copyright information in PMC

References

    1. Babuška I. (1971). Error-Bounds for Finite Element Method. Numer. Math. 16 (4), 322–333. 10.1007/BF02165003 - DOI
    1. Balossino R., Gervaso F., Migliavacca F., Dubini G. (2008). Effects of Different Stent Designs on Local Hemodynamics in Stented Arteries. J. Biomech. 41 (5), 1053–1061. 10.1016/j.jbiomech.2007.12.005 - DOI - PubMed
    1. Beier S., Ormiston J., Webster M., Cater J., Norris S., Medrano-Gracia P., et al. (2016). Hemodynamics in Idealized Stented Coronary Arteries: Important Stent Design Considerations. Ann. Biomed. Eng. 44 (2), 315–329. 10.1007/s10439-015-1387-3 - DOI - PMC - PubMed
    1. Bekal C., Shetty R., Shenoy S. (2018). Numerical Investigation of Influence of Number of Stent Cells and Type of Link on Expansion and Haemodynamic Behaviour of Balloon-Expandable Coronary Stent. Sādhanā. 43 (6), 1–12. 10.1007/s12046-018-0883-1 - DOI
    1. Berry J. L., Santamarina A., Moore, Jr. J. E., Jr., Roychowdhury S., Routh W. D. (2000). Experimental and Computational Flow Evaluation of Coronary Stents. Ann. Biomed. Eng. 28 (4), 386–398. 10.1114/1.276 - DOI - PubMed

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