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In vitro and in vivo testing of a novel, hyperelastic thin film nitinol flow diversion stent
Author(s) -
Kealey C. P.,
Chun Y. J.,
Viñuela F. E.,
Mohanchandra K. P.,
Carman G. P.,
Viñuela F.,
Levi D. S.
Publication year - 2012
Publication title -
journal of biomedical materials research part b: applied biomaterials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.665
H-Index - 108
eISSN - 1552-4981
pISSN - 1552-4973
DOI - 10.1002/jbm.b.32504
Subject(s) - neointima , biomedical engineering , stent , in vivo , materials science , biomaterial , blood flow , aneurysm , medicine , surgery , radiology , restenosis , microbiology and biotechnology , biology
A flexible, low profile, flow diversion stent could replace endovascular coiling for the treatment of intracranial aneurysms. Micropatterned‐thin film nitinol (TFN) is a novel biomaterial with high potential for use in next‐generation endovascular devices. Recent advancements in micropatterning have allowed for fabrication of a hyperelastic thin film nitinol (HE‐TFN). In this study, the authors describe in vitro and in vivo testing of novel HE‐TFN based flow diverting stents. Two types of HE‐TFN with expanded pores having long axes of 300 and 500 μm were used to fabricate devices. In vitro examination of the early thrombotic response in whole blood showed a possible mechanism for the device's function, whereby HE‐TFN serves as a scaffold for blood product deposition. In vivo testing in swine demonstrated rapid occlusion of model wide‐neck aneurysms. Average time to occlusion for the 300‐μm device was 10.4 ± 5.5 min. ( N = 5) and 68 ± 30 min for the 500‐μm device ( N = 5). All aneurysms treated with bare metal control stents remained patent after 240 min ( N = 3). SEM of acutely harvested devices supported in vitro results, demonstrating that HE‐TFN serves as a scaffold for blood product deposition, potentially enhancing its flow‐diverting effect. Histopathology of devices after 42 days in vivo demonstrated a healthy neointima and endothelialization of the aneurysm neck region. HE‐TFN flow‐diverting stents warrant further investigation as a novel treatment for intracranial aneurysms. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2012.