VIRTUAL DEPLOYMENT OF SELF-EXPANDING STENTS IN ANEURYSMATIC INTRACRANIAL VESSELS: DO STENT DESIGN AND VESSEL GEOMETRY MATTER?

摘要

This study provides a finite element based framework to virtually study stent implantation in a patient based cerebral aneurysm model. The developed framework allows to rapidly assess the impact of stent placement and provide insight into the biomechanics of the stented aneurysms. The following main conclusions can be drawn from this analysis: (i) due to the intrinsic adaptability of the open cell design, the Neuroform-like stent adjusts better to the wide-neck aneurysm geometries, resulting in higher strut coverage of the neck; (ii) Altering design can lower the bending stiffness of closed cell stents, yet the high flexibility and low vessel straightening of the simulated open cell stent was not matched; (iii) stent malapposition is present for all investigated cases but the open cell stent shows a higher region of stent struts not apposing well to the vessel wall due to the fish scaling effect. The stiff closed cell design forces the vessel to adapt to the stent shape, which results in a higher number of well apposed stent struts. For the investigated designs and aneurysm geometries, the more flexible closed-cell apposes best.