Covered versus bare self-expanding stents for endovascular treatment of carotid artery stenosis: a stopped randomized trial.
OBJECTIVE
To investigate whether filter-protected carotid artery stenting (CAS) using a covered self-expanding stent reduces the risk of cerebral embolization.


METHODS
Fourteen asymptomatic patients (13 men; median age 77 years, IQR 73-83) were enrolled in a randomized pilot trial comparing the rates of cerebral microembolism during and after filter-protected CAS using either a self-expanding covered (n=8) or a bare (n=6) carotid stent. Transcranial Doppler (TCD) monitoring was done during and for 90 minutes after the procedure. Diffusion-weighted magnetic resonance imaging (DW-MRI) was performed before and 24 hours after CAS. Patients were followed for 6 months for neurological events and occurrence of restenosis.


RESULTS
A significant reduction in ipsilateral microembolic signals by TCD was observed with the covered (median 1, IQR 0-4) versus the bare stent (median 6, IQR 3-8; p=0.043). Comparison of the preprocedural and 24-hour postprocedural DW-MRI images showed no new ipsilateral lesions but 1 new lesion in the contralateral hemisphere in the covered stent group, resulting in an overall 7% (95% CI 0%-20%) rate of new ischemic lesions. No neurological complications occurred up to 6 months. Restenosis (>70%) occurred in 3 (38%) of 8 patients with the covered versus none of the bare stents (p=0.21). The trial was stopped when the third restenosis of a covered stent was detected.


CONCLUSIONS
Self-expanding covered stents potentially reduce the risk of cerebral microembolism during and after carotid stenting. However, the problem of in-stent restenosis has to be resolved before these devices can be considered for further investigation.
Schillinger
Martin
M
Department of Angiology, Vienna Medical University, Viennia, Austria. martin.schillinger@meduniwien.ac.at
Dick
Petra
P
Wiest
Gerald
G
Gentzsch
Stephan
S
Sabeti
Schila
S
Haumer
Markus
M
Willfort
Andrea
A
Nasel
Christian
C
Wöber
Christian
C
Zeitlhofer
Josef
J
Minar
Erich
E
D000368:Aged; D000800:Angioplasty, Balloon / Q000009:adverse effects*; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging; D016893:Carotid Stenosis / Q000000981:diagnostic imaging / Q000628:therapy*; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006083:Graft Occlusion, Vascular / Q000175:diagnosis*; D006801:Humans; D020766:Intracranial Embolism / Q000000981:diagnostic imaging / Q000209:etiology*; D008297:Male; D010865:Pilot Projects; D011183:Postoperative Complications; D015607:Stents / Q000009:adverse effects*; D017585:Ultrasonography, Doppler, Transcranial