Abstract 11884: Successful Preclinical Study of Microporous Covered Stents for Intracranial Aneurysms

Abstract

Introduction: Treatment of large or giant cerebral aneurysms with broad neck is extremely difficult or carries high risks, even with clinical available surgical method or endovascular one using coils with the assistance of bare stents. We are developing microporous covered stents (Goodman, Japan) for the treatment of intracranial aneurysms. In this study, as a preclinical study, their performances were evaluated in three different in vivo animal models under reliability assurance system (RAS). Methods and Results: The covered stents were prepared using specially designed flexible balloon-expandable stents (CoCr; diameter; 3.5~5.0 mm, length; 16~28 mm) by dip-coating to cover their strut completely with polyurethane membrane (thickness; 20 μm) followed by laser-based microprocessing (pore size; 100 μm, opening ratio; ~30%). All animal experiments were performed under RAS. 1) In canine curved vessel model (5 mm in diameter), all stents mounted on the derivery catheter could smoothly pass the tortuous vessel with little arterial damage (n=10). 2) In canine sidewall aneurysm model, all post-immediate run showed disappearance of the aneurysm (over 7 mm in size, 4 mm in wide), and histological examination at 3 months revealed complete endothelialization at the aneurysmal neck and entirely organized aneurysm (n=20). 3) In rabbit aortic model (3 mm in diameter), just after placing a single stent lumbar arteries (less than 1 mm) were patent with good run-off. Even after placing the second stent in an overlapped fashion lumbar arteries are still patent. After 3 months, both the parent artery and branching lumbar arteries are patent in all cases (n=15). The safety of the covering material was guaranteed at over 2 years (n=10). Conclusions: Excellent embolization performance was confirmed in all cases even at the large and wide-necked aneurysms on the tortuous vessels with high reliability. Based on the obtained perfect preclinical results we are planning the first in human study of the covered stents for intracranial aneurysms in 2015.