title: Thermomechanical properties, collapse pressure, and expansion of shape memory polymer neurovascular stent prototypes.
abstract: Shape memory polymer stent prototypes were fabricated from thermoplastic polyurethane. Commercial stents are generally made of stainless steel or other alloys. These alloys are too stiff and prevent most stent designs from being able to navigate small and tortuous vessels to reach intracranial lesions. A solid tubular model and a high flexibility laser etched model are presented. The stents were tested for collapse in a pressure chamber. At 37 degrees C, the full collapse pressure was comparable to that of commercially available stents, and higher than the estimated maximum pressure exerted by intracranial arteries. However, there is a potential for onset of collapse, which needs further study. The stents were crimped and expanded, the laser-etched stent showed full recovery with an expansion ratio of 2.7 and a 1% axial shortening.
authors.affiliation: Department of Biomedical Engineering, University of California Davis, Davis, California 95616, USA.
authors.forename: Géraldine M
authors.initials: GM
authors.lastname: Baer
authors.forename: Thomas S
authors.initials: TS
authors.lastname: Wilson
authors.forename: Ward
authors.initials: W
authors.lastname: Small
authors.forename: Jonathan
authors.initials: J
authors.lastname: Hartman
authors.forename: William J
authors.initials: WJ
authors.lastname: Benett
authors.forename: Dennis L
authors.initials: DL
authors.lastname: Matthews
authors.forename: Duncan J
authors.initials: DJ
authors.lastname: Maitland
mesh_terms: D008962:Models, Theoretical; D018919:Neovascularization, Physiologic; D011108:Polymers; D011312:Pressure; D015607:Stents
chemical_list: D011108:Polymers