Enhancement of Mechanical Properties and Testing of Nitinol Stents in Cerebral Aneurysm Simulation Models

Hyo Geun Nam, Chang Min Yoo, Seoung Min Baek, Han Ki Kim, Jae Hee Shin, Min Ho Hwang, Ga Eun Jo, Kyong Soo Kim, Jae Hwa Cho, Seung Hoon Lee, Ho Chul Kim, Choon Hak Lim, Hyuk Choi, Kyung Sun

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

Stents are promising medical devices widely used in the prevention of cerebral aneurysm rupture. As the performance of stents depends on their mechanical properties and cell configuration, the aim of this study was to optimize the stent design and test the hemodynamic properties by using computational solid mechanics and computational fluid dynamics. In order to test their performance, computer-based cerebral aneurysm models that mimic the conditions present after implantation into the human brain were tested. The strut configuration selected was the closed-cell type, and nitinol was chosen as the material for stent manufacture because the innate characteristics of this material increase stent flexibility. Three ideal sample stent types with different cell configurations were manufactured. Computational solid mechanics analysis of the sample stents showed over 30% difference in flexibility between stents. Furthermore, using a cerebral aneurysm model simulation, we found that the stents eased the hemodynamic factors of the cerebral aneurysm and lessened the flow velocity influx into the sac. A decrease in flow velocity led to a 50-60% reduction in wall shear stress, which is expected to prevent aneurysm rupture under clinical conditions. Stent design optimization was carried out by simulation and electropolishing. Corrosion resistance and surface roughness were evaluated after electropolishing performed under variable conditions, but 40V and 10s were the most optimal.

Original languageEnglish
Pages (from-to)E213-E226
JournalArtificial Organs
Volume39
Issue number12
DOIs
Publication statusPublished - 2015 Dec 1

Keywords

  • Closed-cell type
  • Computational fluid dynamics
  • Electropolishing
  • Nickel-titanium shape memory alloys
  • Stent

ASJC Scopus subject areas

  • Biomaterials
  • Biomedical Engineering
  • Bioengineering
  • Medicine (miscellaneous)

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  • Cite this

    Nam, H. G., Yoo, C. M., Baek, S. M., Kim, H. K., Shin, J. H., Hwang, M. H., Jo, G. E., Kim, K. S., Cho, J. H., Lee, S. H., Kim, H. C., Lim, C. H., Choi, H., & Sun, K. (2015). Enhancement of Mechanical Properties and Testing of Nitinol Stents in Cerebral Aneurysm Simulation Models. Artificial Organs, 39(12), E213-E226. https://doi.org/10.1111/aor.12564