This prospective, multicenter, randomized controlled study enrolled patients undergoing carotid artery stenting (CAS) with cerebral embolic protection for carotid artery stenosis. They were randomly assigned to either a combination of proximal balloon occlusion, filter protection, intermediate catheter or filter protection alone. The study included 132 patients, and the primary endpoint was the number of new infarcts on cerebral diffusion-weighted imaging (DWI) within 48 hours (±24 hours) post-procedure.

Carotid artery stenting (CAS) is an established treatment for carotid stenosis, yet the optimal cerebral embolic protection strategy remains uncertain. This prospective, multicenter, randomized, open-label, controlled trial will enroll 132 patients with symptomatic (≥50%) or asymptomatic (≥70%) carotid stenosis, who will be randomly assigned 1:1 to either experimental multimodal protection (Balloon Guide Catheter plus distal filter and intermediate catheter aspiration) or conventional distal filter protection alone. The primary endpoint is the number of new infarcts on post-procedural diffusion-weighted imaging (DWI) assessed within 48 hours (±24 hours), with secondary endpoints including device success and defect rates, incidences of symptomatic and all intracranial hemorrhage within 48 hours post-procedure, ipsilateral target-vessel stroke, TIA, major adverse events (stroke/death/MI), and adverse/serious adverse events at 30 and 90 days, all-cause mortality at 90 days, changes in mRS score at 30 and 90 days, and procedure-related complications (e.g., dissection, hyperperfusion syndrome).

Inclusion Criteria:

1. Aged between 18 and 80 years (inclusive), with no gender restriction.
2. Imaging diagnosis indicates symptomatic carotid artery stenosis (by NASCET method) ≥50% or asymptomatic carotid artery stenosis (by NASCET method) ≥70%.
3. Suitable for carotid artery stenting.
4. Good compliance, voluntarily signed the informed consent form, and able to follow up as required.

Exclusion Criteria:

1. Severe tortuosity or calcification of the diseased vessel, preventing device delivery.
2. Patients with ipsilateral external carotid artery occlusion or severe stenosis of the intracranial segment of the internal carotid artery.
3. Patients with contralateral common carotid artery occlusion or severe stenosis or occlusion of the internal carotid artery.
4. Patients with severe stenosis or occlusion of the vertebrobasilar artery (excluding non-dominant vertebral artery).
5. Spontaneous intracranial hemorrhage, massive cerebral infarction, progressive stroke, or myocardial infarction within the past 3 months.
6. Presence of substantial acute or subacute thrombus adjacent to the lesion.
7. mRS > 3.
8. Patients with a clear risk of cardioembolism, such as atrial fibrillation, or those with definite indications for anticoagulation.
9. Chronic obstructive pulmonary disease requiring long-term continuous oxygen therapy.
10. Patients with prior stent treatment in the ipsilateral head and neck vessels.
11. Patients with end-stage renal failure requiring dialysis.
12. Life expectancy less than 6 months.
13. Patients unsuitable for magnetic resonance imaging (MRI) for any reason.
14. Patients with absolute or relative contraindications to antiplatelet therapy.
15. Inability to cooperate with the study due to dementia or mental disorder.