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A computational study of mechanical performance of bioresorbable polymeric stents with design variations

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journal contribution
posted on 30.11.2018, 16:17 by Tianyang Qiu, Liguo ZhaoLiguo Zhao, Mo Song
Purpose: The study compared the mechanical behavior of bioresorbable polymeric stents with various designs during deployment, and investigated their fatigue performance under pulsatile blood pressure loading. Methods: Finite element simulations have been carried out to compare the mechanical performance of four bioresorbable polymeric stents, i.e., Absorb, Elixir, Igaki-Tamai and RevaMedical, during deployment in diseased artery. Tri-folded balloon was modelled to expand the crimped stent onto the three-layered arterial wall with plaque. Cyclic diastolic-systolic pressure loading was applied to both stent and arterial wall to study fatigue behavior. Results: Stents with larger U-bend and longer axial strut demonstrate more flexibility but suffer from severe dogboning and recoiling effects. Stress concentrations in the stent, as well as in the plaque and artery, are higher for stents designed with increased rigidity such as those with smaller U-bends and shorter axial struts. Simulations of fatigue deformation for Elixir stent demonstrate that the U-bends, with high stress concentrations, have a potential risk of fatigue failure under pulsatile systolic-diastolic blood pressure as opposed to the counter metallic stents which are normally free of fatigue failure. Conclusion: The structural behaviour of bioresorbable polymeric stent is strongly affected by its design, in terms of expansion, dogboing, recoiling and stress distribution during the deployment process.

Funding

LG Zhao acknowledge the support from the British Heart Foundation (Grant number: FS/15/21/31424; Title: Towards controlling the mechanical performance of polymeric bioresorbable vascular scaffold during biodegradation) and the Royal Society of UK (Grant number: IE160066; Title: Evaluating the Performance of Additively Manufactured Endovascular Scaffolds).

History

School

  • Aeronautical, Automotive, Chemical and Materials Engineering

Department

  • Materials

Published in

Cardiovascular Engineering and Technology

Volume

10

Issue

1

Pages

46–60

Citation

QIU, T., ZHAO, L. and SONG, M., 2018. A computational study of mechanical performance of bioresorbable polymeric stents with design variations. Cardiovascular Engineering and Technology, 10 (1), pp.46–60.

Publisher

© Biomedical Engineering Society. Published by Springer Verlag

Version

AM (Accepted Manuscript)

Publisher statement

This is a post-peer-review, pre-copyedit version of an article published in Cardiovascular Engineering and Technology. The final authenticated version is available online at: https://doi.org/10.1007/s13239-018-00397-9

Acceptance date

27/11/2018

Publication date

2018-12-10

ISSN

1869-408X

eISSN

1869-4098

Language

en