A systematic approach to further improve stent-graft performance

Abstract

Thoracic endovascular aortic repair (TEVAR) is limited by the complicated anatomy of an aortic arch. This study proposed a new stent-graft (SG) design with slits that can positively improve the sealing effect between the aorta and SG while maintaining blood flow to supra-aortic branches. Firstly, a new SG was designed by changing the geometrical parameters (strut height, strut radius, strut diameter, etc.) based on previous research. The main mechanical performances of the SG were evaluated. Results showed that the new design improved the sealing effect and decreased the Type-Ι endoleak risk. The new design also had the comparable radial force, compression strength and fatigue life. Secondly, a fluid dynamic analysis was carried out in an ideal normal aortic arch model to evaluate the slit SG design. Satisfactory flow perfusion in branches was obtained, and no undesirable vortexes were found. Therefore, the hemodynamic environment in the aortic arch after the SG implantation was not significantly changed. The present study indicates that the design thought has a potential to deal with the technical difficulties of TEVAR at the aortic arch. This study provides the basis for potential optimization to obtain a more applicable SG design.

Keywords

• Thoracic aortic arch
• Finite element analyses
• Mechanical properties
• Computational fluid dynamics
• Slit