Protected carotid stenting: safety and efficacy of the MedNova NeuroShield filter

Neuroprotection during carotid stenting has the potential to reduce procedural atheroembolic sequelae. We report the United Kingdom experience of NeuroShield (MedNova Ltd, Horsham, West Sussex, United Kingdom).

We performed a prospective cohort analysis of 50 consecutive patients (50 lesions) in a regional vascular tertiary referral center (catchment area one million) that provides an institutional service for the short term. The subjects were all the patients referred for carotid stenting after preassessment by a multidisciplinary team. All the patients underwent pretreatment with antiplatelet agents. Forty-two patients had atherosclerotic stenosis of the carotid bifurcation between 70% and 95% (with North American Symptomatic Carotid Endarterectomy Trial criteria). Six patients had restenosis after endarterectomy. Two had previous local radiotherapy. Forty-two patients were symptomatic (amaurosis fugax/central retinal artery occlusion in 11 cases, and hemispheric transient ischemic attack/cerebrovascular accident in 31 cases). Eight patients were asymptomatic with bilateral high-grade stenoses, with six cases before coronary artery bypass grafting. The intervention performed was protected primary carotid stenting. Outcome measures were procedural atheroembolic events, including all-stroke and death rates up to 30 days, and analysis of retrieved debris in a subset of 11 cases.

The technical success rate was 50/50 (100%) for stenting and 49/50 (98%) for filter placement/retrieval. Technical complications comprised nonsymptomatic spasm at the filter site (flow limiting in two cases and non-flow limiting in five cases). Procedural events were one minor stroke (patient fully recovered within 48 hours) in a complex clinical setting and one ventricular fibrillation arrest in a patient before coronary artery bypass grafting who was resuscitated without neurologic event. At 30 days, the death or major disability from stroke rate was 2/50 (4%). No cases were atheroembolic. The all-stroke/death rate was 3/50 (6%). The two deaths were the result of a fatal hemorrhagic stroke that occurred at 4 days and was thought to be caused by reperfusion and a perforated ventricle caused by a temporary pacing wire. One femoral pseudoaneurysm followed failed closure device deployment and required percutaneous thrombin injection. The mean particle number per patient was 12 (range, 0 to 41). The mean particle diameter was 284.9 microm(range, 31 to 1430 microm). The mean ellipsoid volume load was 0.1602 mm(3) (range, 0.0005 to 0.1968 mm(3)).

Carotid stenting protected with NeuroShield is safe. The filter traps embolic debris liberated during the procedure.