A novel flexible, retrievable endovascular stent system for small-vessel anatomy: preliminary in vivo data.
OBJECTIVE
This study assessed the in vivo delivery, retrievability, short-term patency, and cellular response to a new flexible endovascular stent system in a rabbit model. The stent is designed for delivery through a microcatheter and is fully retrievable with electrolytic detachment from a delivery wire.


METHODS
We successfully deployed nine stents (range of sizes, 2.5-4 mm diameter, 15-35 mm length) in six straight (carotid) and three angled (subclavian) arteries of six Chinchilla Bastard rabbits. Serial imaging was performed by using intravenous digital subtraction angiography (IVDSA), contrast-enhanced MR angiography (CEMRA), time-of-flight MR angiography (TOF), and CT-angiography 3 days and 4 weeks after stent deployment. Subjects were euthenized after 4 weeks (n = 5), and stents were removed for histologic analysis.


RESULTS
Stent deployment was feasible in all cases. After initial deployment, all stents could be fully retrieved within the microcatheter. The detachment zone and the distal stent marker were easily visible under fluoroscopy, and final detachment occurred reliably in all cases. We observed no procedural complications. Noninvasive imaging by using IVDSA, MR angiography, and CT angiography was feasible in this stent system and demonstrated all arteries patent and not narrowed at 3 days and 4 weeks, findings that were confirmed by histologic analysis.


CONCLUSIONS
This electrolytically detachable stent is promising as a treatment for intracranial arteries, because it can be delivered through microcatheters small enough for intracranial navigation. It is fully retrievable, thus providing greater control than currently available stents. Noninvasive imaging by using IVDSA, MR angiography, and CT angiography is feasible in this stent system and may be useful for follow-up. Further long-term data are needed.
Doerfler
Arnd
A
Department of Neuroradiology, Institute of Diagnostic and Interventional Radiology, University of Essen Medical School, Essen, Germany.
Becker
Wolfgang P H
WP
Wanke
Isabel
I
Goericke
Sophia L
SL
Mueller
K M
KM
Blechschmid
Nina
N
Flesser
Achim
A
Monstadt
Hermann
H
Forsting
Michael
M
D000818:Animals; D001808:Blood Vessels / Q000033:anatomy & histology*; D020878:Device Removal; D004867:Equipment Design; D011817:Rabbits; D015607:Stents; D014656:Vascular Surgical Procedures / Q000379:methods