title: Simulated biomechanical responses at a curved arterial segment after Wingspan Stent deployment in swine.
abstract: OBJECTIVE
  Endovascular treatment with the Wingspan Stent is frequently associated with in-stent restenosis at the curved portion, leading to late-phase stroke. To explore the cause of stroke complications after treatment with the Wingspan Stent, we simulated the biomechanical responses at a curved arterial segment using the finite element method.
  
  
  METHODS
  A Wingspan stent was deployed at a slightly curved ascending pharyngeal artery (APA) in swine. Several stress distributions modeling solid mechanics were analyzed with structural deformation. Histopathological analysis of the selected APA was assessed at 28 days after stenting.
  
  
  RESULTS
  Arterial straightening was simulated in this study. Both radial stress (RS) and circumferential stress (CS) concentrations increased at both stent ends. Marked lower axial stress (AS) concentration was observed at the outer wall of an arterial curvature. The proximal stent segment, ending in the curved portion, significantly impacted the solid mechanical environment. Eccentric neointimal hyperplasia was observed at the curved segment.
  
  
  CONCLUSIONS
  These results show that the Wingspan stent exaggerated the non-uniform stress distributions in a curved artery. The understanding of stent-arterial wall interactions is of value to identify the current limitations of intracranial stenting, and will help to improve this treatment methodology and future devices.
authors.affiliation: Division of Interventional Neuroradiology, Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA. MFujimoto@mednet.ucla.edu
authors.forename: Motoaki
authors.initials: M
authors.lastname: Fujimoto
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Shobayashi
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tateshima
authors.forename: Harry V
authors.initials: HV
authors.lastname: Vinters
authors.forename: Fernando
authors.initials: F
authors.lastname: Viñuela
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena / Q000502:physiology; D017536:Carotid Artery, Common / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery*; D003198:Computer Simulation; D011859:Radiography; D015607:Stents; D013314:Stress, Mechanical; D013552:Swine