Treatment of elastase-induced intracranial aneurysms in New Zealand white rabbits by use of a novel neurovascular embolization stent device.
BACKGROUND
This study aims to test a novel balloon expandable stent covered with a polytetrafluoroethylene membrane (neurovascular embolization cover (NEC), NFocus Neuromedical, Palo Alto, California) regarding angiographic and histologic aneurysm occlusion. Radiopacity, stent placement, navigation, flexibility, and intimal proliferation were also evaluated.


METHODS
Eight aneurysms were induced in New Zealand white rabbits. Digital subtraction angiography (DSA) was performed directly after stent placement and after 5 and 10 min. Four and 8 weeks after stent placement, an intra-arterial DSA control was performed. The animals were then sacrificed and the aneurysms histologically evaluated.


RESULTS
The radiopaque markers were clearly visible. Although all the stents were easily navigated into the subclavian artery, the limited flexibility of the stent resulted in straightening of the vessel in four cases. As a result, exact stent placement was achieved and acutely confirmed in only two cases. However, at sacrifice, angiographic and histologic occlusion was noted at follow-up in five aneurysms.


CONCLUSIONS
In tortuous anatomy, the relative stiffness of the stent makes exact stent placement challenging. This may have been exacerbated by the movement of the vessels due to proximity to the heart in this model. Future studies should evaluate whether existing residual flow into an aneurysm lumen might lead to embolization without any additional treatment. Anticoagulation remains a very important part of aneurysm treatment with stents. The trend toward aneurysm occlusion by excluding it from the blood circulation seems a promising method in future endovascular therapy. The NEC device shows good potential.
Kühn
Anna Luisa
AL
Department for Interventional and Diagnostic Neuroradiology, Saarland University, Saarland, Germany.
Roth
Christian
C
Romeike
Bernd
B
Grunwald
Iris Quasar
IQ
D000818:Animals; D063125:Balloon Embolectomy / Q000295:instrumentation*; D001807:Blood Vessel Prosthesis; D004195:Disease Models, Animal; D004621:Embolization, Therapeutic / Q000295:instrumentation*; D019544:Equipment Failure Analysis; D002532:Intracranial Aneurysm / Q000139:chemically induced / Q000000981:diagnostic imaging* / Q000601:surgery*; D010196:Pancreatic Elastase; D011474:Prosthesis Design; D011817:Rabbits; D011859:Radiography; D015607:Stents; D016896:Treatment Outcome
D010196:Pancreatic Elastase