title: Microstructured Thin Film Nitinol for a Neurovascular Flow-Diverter.
abstract: A cerebral aneurysm occurs as a result of a weakened blood vessel, which allows blood to flow into a sac or a ballooned section. Recent advancement shows that a new device, 'flow-diverter', can divert blood flow away from the aneurysm sac. People found that a flow-diverter based on thin film nitinol (TFN), works very effectively, however there are no studies proving the mechanical safety in irregular, curved blood vessels. Here, we study the mechanical behaviors and structural safety of a novel microstructured TFN membrane through the computational and experimental studies, which establish the fundamental aspects of stretching and bending mechanics of the structure. The result shows a hyper-elastic behavior of the TFN with a negligible strain change up to 180° in bending and over 500% in radial stretching, which is ideal in the use in neurovascular curved arteries. The simulation determines the optimal joint locations between the TFN and stent frame. In vitro experimental test qualitatively demonstrates the mechanical flexibility of the flow-diverter with multi-modal bending. In vivo micro X-ray and histopathology study demonstrate that the TFN can be conformally deployed in the curved blood vessel of a swine model without any significant complications or abnormalities.
authors.affiliation: Department of Industrial Engineering, University of Pittsburgh, Pittsburgh, PA 15261, USA.
authors.forename: Yanfei
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, VA 23284, USA.
authors.forename: Connor
authors.initials: C
authors.lastname: Howe
authors.affiliation: Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, VA 23284, USA.
authors.forename: Yongkuk
authors.initials: Y
authors.lastname: Lee
authors.affiliation: Division of Mechanical and Automotive Engineering, Kongju National University, Cheonan, Chungnam, 314-701, Republic of Korea.
authors.forename: Seongsik
authors.initials: S
authors.lastname: Cheon
authors.affiliation: Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, VA 23284, USA.|Center for Rehabilitation Science and Engineering, Virginia Commonwealth University, VA 23298, USA.
authors.forename: Woon-Hong
authors.initials: WH
authors.lastname: Yeo
authors.affiliation: Department of Industrial Engineering, University of Pittsburgh, Pittsburgh, PA 15261, USA.|Department of Bioengineering, University of Pittsburgh, PA 15261, USA.
authors.forename: Youngjae
authors.initials: Y
authors.lastname: Chun
mesh_terms: D000497:Alloys; D000818:Animals; D004195:Disease Models, Animal; D057510:Endovascular Procedures / Q000295:instrumentation*; D002532:Intracranial Aneurysm / Q000601:surgery*; D008422:Materials Testing; D015607:Stents; D013552:Swine
chemical_list: D000497:Alloys; C013616:nitinol