title: Mechanical design of an intracranial stent for treating cerebral aneurysms.
abstract: Endovascular treatment of cerebral aneurysms using stents has advanced markedly in recent years. Mechanically, a cerebrovascular stent must be very flexible longitudinally and have low radial stiffness. However, no study has examined the stress distribution and deformation of cerebrovascular stents using the finite element method (FEM) and experiments. Stents can have open- and closed-cell structures, and open-cell stents are used clinically in the cerebrovasculature because of their high flexibility. However, the open-cell structure confers a risk of in-stent stenosis due to protrusion of stent struts into the normal parent artery. Therefore, a flexible stent with a closed-cell structure is required. To design a clinically useful, highly flexible, closed-cell stent, one must examine the mechanical properties of the closed-cell structure. In this study, we investigated the relationship between mesh patterns and the mechanical properties of closed-cell stents. Several mesh patterns were designed and their characteristics were studied using numerical simulation. The results showed that the bending stiffness of a closed-cell stent depends on the geometric configuration of the stent cell. It decreases when the stent cell is stretched in the circumferential direction. Mechanical flexibility equal to an open-cell structure was obtained in a closed-cell structure by varying the geometric configuration of the stent cell.
authors.affiliation: School of Integrated Design Engineering, Graduate School of Keio University, Keio University, Hiyoshi, Kohoku, Yokohama, Japan. shobayashi@tani.sd.keio.ac.jp
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Shobayashi
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Tanoue
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tateshima
authors.forename: Kazuo
authors.initials: K
authors.lastname: Tanishita
mesh_terms: D019245:Compressive Strength; D020342:Finite Element Analysis; D002532:Intracranial Aneurysm / Q000601:surgery*; D008422:Materials Testing; D055595:Mechanical Phenomena; D008958:Models, Molecular; D008968:Molecular Conformation; D011474:Prosthesis Design / Q000379:methods*; D015203:Reproducibility of Results; D015607:Stents