ECCOMAS 2024

Designing novel vascular stents through topological optimization

  • Mezzadri, Francesco (University of Modena and Reggio Emilia)
  • Carbonaro, Dario (Politecnico di Torino)
  • Ferro, Nicola (Politecnico di Milano)
  • Gallo, Diego (Politecnico di Torino)
  • Audenino, Alberto (Politecnico di Torino)
  • Chiastra, Claudio (Politecnico di Torino)
  • Morbiducci, Umberto (Politecnico di Torino)
  • Perotto, Simona (Politecnico di Milano)

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The implantation of stents is a common treatment for vascular diseases. Designing the stent is crucial, as it can impact the device performance and the risk of complications like in-stent restenosis. Traditional design methods usually involve slightly incremental adjustments to a limited set of stent geometries. Thus, creating entirely new and potentially more effective designs through standard strategies is challenging and costly. A more flexible and patient-specific approach would be beneficial. In this work, we explore a framework that uses topology optimization (TO) for designing innovative vascular stents. The stent is conceptualized as a cylindrical surface created by replicating a 2D unit cell [1]. The idea implies designing this unit cell to ensure desired (mechanical, fluid dynamics, structural) properties for the entire device. To achieve this, we utilize the microSIMPATY algorithm [2], a novel design procedure that integrates TO at the micro-scale with inverse homogenization, to translate design requirements at the macro-scale into topology specifications at the micro-scale. In particular, we focus on foreshortening and radial force among the biomechanical properties selected for guiding the design of the new stents. These properties influence the stent's shortening after implantation and the force it exerts on the vessel, respectively. Finally, the designs generated by the microSIMPATY algorithm are enhanced by incorporating an anisotropic adapted mesh. This additional feature proved to facilitate the creation of non-standard layouts, distinguishing them from commercially available stents. This study was carried out within the RESET project, funded by the European Union – NextGenerationEU, Italian Ministry of University and Research, Italy, within the PRIN 2022 PNRR program (D.D.1409 del 14/09/2022). REFERENCES [1] D. Carbonaro, F. Mezzadri, N. Ferro, G. De Nisco, A. L. Audenino, D. Gallo, C. Chiastra, U. Morbiducci and S. Perotto. Design of innovative self-expandable femoral stents using inverse homogenization topology optimization. Computer Methods in Applied Mechanics and Engineering, 416, art. 116288, 2023. [2] N. Ferro, S. Micheletti and S. Perotto. Density-based inverse homogenization with anisotropically adapted elements. Lecture Notes in Computational Science and Engineering, 132:211–221, 2020.