Distal Versus Proximal Protection on Cerebral Microembolization During High-risk Carotid Artery Stenting

A multicenter, prospective, outcome-assessor-blinded, randomized controlled trial study (MOSCASH) is designed to compare the efficiency of distal and proximal embolism protection devices during carotid angioplasty and stenting (CAS) procedure of patients with high-intensity signal in the plaque on the time-of-flight magnetic resonance angiography(TOF-MRA) .

CAS is an alternative to carotid endarterectomy(CEA) for treating carotid stenosis with a similar efficacy in preventing future stroke. High-intensity signal in the plaque on the TOF-MRA is associated to a high risk of cerebral embolism during stenting. The evidence of protection selection in such patients was limited. A multicenter, prospective, outcome-assessor-blinded, randomized controlled trial study (MOSCASH) is designed to compare the efficiency of distal and proximal embolism protection devices during CAS procedure of patients with high-intensity signal in the plaque on the TOF-MRA. Asymptomatic patients with internal carotid artery stenosis ≥ 70% (NASCET) and symptomatic patients with a stenosis ≥ 50% who have a high-intensity signal in the relevant plaques on TOF-MRA will be included. Patients are randomized in two balanced groups (1:1) to receive CAS with either distal (Spider FX) or proximal (Mo.Ma Ultra) protection. The primary endpoint is the incidence of new cerebral ipsilateral ischemic lesions on the Diffusion Weighted Imaging(DWI) in 7-days post operation. Secondary endpoints include the number, size, location of new cerebral ischemic lesions on the DWI, procedural complications, stroke, myocardial infarction, and death in 7 days.

Eligibility Criteria:
Inclusion Criteria:

1. Male and female patients 40 years of age and older.
2. Asymptomatic patients with internal carotid artery stenosis≥70% on angiography.
3. Symptomatic patients with internal carotid artery stenosis≥50% on angiography.
4. High-intensity Signal in the relevant plaques on the TOF-MRA.
5. Anatomic characteristics of the lesions that made it possible to use either type of embolism protective device (proximal or distal).
6. The patient or legally authorized representative has been informed of the nature of the study, agrees to its provisions, and has provided written informed consent, approved by the appropriate Medical Ethics Committee, Institutional Review Board, or Human Research Ethics Committee.

Exclusion Criteria:

1. Extensive ipsilateral or disabling stroke(mRS≥2).
2. Ischemic ipsilateral stroke in 15 days, with significant new ischemic lesions on the DWI image.
3. Ipsilateral intracranial artery stenosis which needs to be treated at the same time.
4. Extremely calcified aortic arc that compromised the origin of the common carotid artery or the brachiocephalic trunk.
5. Chronic or paroxysmal atrial fibrillation treated with oral anticoagulation.
6. Acute coronary syndrome in the 30-day period before the procedure.
7. Patient has a history of bleeding diathesis within 1 month or coagulopathy or patients in whom antiplatelet and/or anticoagulant therapy is contraindicated.
8. Intolerance or allergic reaction to a study medication without a suitable management alternative.
9. Pregnant or lactating female patient.