PT  - JOURNAL ARTICLE
AU  - Y. Ding
AU  - D. Dai
AU  - D.F. Kallmes
AU  - D. Schroeder
AU  - C.P. Kealey
AU  - V. Gupta
AU  - A.D. Johnson
AU  - R. Kadirvel
TI  - Preclinical Testing of a Novel Thin Film Nitinol Flow-Diversion Stent in a Rabbit Elastase Aneurysm Model
AID  - 10.3174/ajnr.A4568
DP  - 2015 Oct 22
TA  - American Journal of Neuroradiology
4099  - http://www.ajnr.org/content/early/2015/10/22/ajnr.A4568.short
4100  - http://www.ajnr.org/content/early/2015/10/22/ajnr.A4568.full
AB  - BACKGROUND AND PURPOSE: Thin film nitinol can be processed to produce a thin microporous sheet with a low percentage of metal coverage (<20%) and high pore attenuation (∼70 pores/mm2) for flow diversion. We present in vivo results from the treatment of experimental rabbit aneurysms by using a thin film nitinol–based flow-diversion device.MATERIALS AND METHODS: Nineteen aneurysms in the rabbit elastase aneurysm model were treated with a single thin film nitinol flow diverter. Devices were also placed over 17 lumbar arteries to model perianeurysmal branch arteries of the intracranial circulation. Angiography was performed at 2 weeks (n = 7), 1 month (n = 8), and 3 months (n = 4) immediately before sacrifice. Aneurysm occlusion was graded on a 3-point scale (grade I, complete occlusion; grade II, near-complete occlusion; grade III, incomplete occlusion). Toluidine blue staining was used for histologic evaluation. En face CD31 immunofluorescent staining was performed to quantify neck endothelialization.RESULTS: Markedly reduced intra-aneurysmal flow was observed on angiography immediately after device placement in all aneurysms. Grade I or II occlusion was noted in 4 (57%) aneurysms at 2-week, in 6 (75%) aneurysms at 4-week, and in 3 (75%) aneurysms at 12-week follow-up. All 17 lumbar arteries were patent. CD31 staining showed that 75% ± 16% of the aneurysm neck region was endothelialized. Histopathology demonstrated incorporation of the thin film nitinol flow diverter into the vessel wall and no evidence of excessive neointimal hyperplasia.CONCLUSIONS: In this rabbit model, the thin film nitinol flow diverter achieved high rates of aneurysm occlusion and promoted tissue in-growth and aneurysm neck healing, even early after implantation.AbbreviationTFNthin film nitinol