Occluding the proximal carotid artery with a balloon may confer better protection against cerebral embolization than a distal filter device during carotid stenting, a randomized trial found.
Compared with distal filter protection, proximal balloon occlusion significantly reduced the incidence of new ischemic lesions, according to Joachim Schofer, MD, from Hamburg University Cardiovascular Center in Hamburg, Germany, and colleagues.
The balloon occlusion strategy also resulted in a significant decrease in the number, as well as the volume, of new cerebral ischemic lesions, according to the study published in the Feb. 7 issue of Journal of the American College of Cardiology.
“These data are sensible, since in contrast to distal embolic protection devices, proximal embolic protection devices provide embolic protection prior to crossing the target lesion with a guidewire, and should be more efficient at capturing and removing debris since they are not dependent on filter pore size or particle dimensions,” wrote Robert D. Safian, MD, from the William Beaumont School of Medicine in Royal Oaks, Mich., in an accompanying editorial.
Although there are no restrictions for carotid endarterectomy reimbursement, the same is not true for carotid artery stenting (CAS), Safian pointed out.
The Centers for Medicare and Medicaid Services (CMS) will not reimburse carotid stenting for any standard-risk patients, Safian told MedPage Today. Reimbursement for stenting in high-risk patients is subject to certain restrictions, including: For symptomatic patients, the procedure must take place in a CMS-approved institution and the operators must use FDA-approved stents and embolic protection devices Both symptomatic and asymptomatic patients must be enrolled in an approved investigational device exemption trial or post-market approval registry.
There are several FDA-approved carotid stents, as well as approved embolic protection devices, including distal mesh filters and distal and proximal balloon occluding devices.
In his commentary, Safian listed the similarities in outcomes between surgery and carotid stenting, which include results from several seminal trials such as SAPPHIRE and CREST.
“Further [carotid artery stenting] trials are not needed to support reimbursement. It is time for CMS to align with professional guidelines and establish equipoise for carotid endarterectomy and CAS,” he concluded.
The trials comparing surgery with stenting used filters to stop emboli from causing periprocedural stroke. In the current study, Schofer and colleagues tested a proximal balloon occlusion device, which occludes the external and common carotid arteries to induce reversed flow before the lesion is crossed and stented.
“Whether this results in a more effective cerebral embolic protection than a filter device has never to our knowledge been studied in a randomized trial,” the investigators wrote.
They conducted the PROFI (Prevention of Cerebral Embolization by Proximal Balloon Occlusion Compared to Filter Protection During Carotid Artery Stenting) study, in which they randomized 62 consecutive patients (mean age 71, three-quarters men) equally to either filter or balloon occlusion.
The single-center trial employed diffusion-weighted MR imaging to identify new ischemic cerebral lesions. The stent operator was very experienced, the authors noted, and he used the same devices in each arm.
The primary endpoint was the incidence of new ischemic lesions between the two embolic strategies up to 24 hours post-procedure. The secondary endpoint was the number and volume of new lesions and major adverse cardiovascular and cerebral events (including death, stroke, myocardial infarction, and vascular complications) at 30 days, bleeding complications, and device crossover.
Baseline demographic, clinical, and lesion characteristics were similar between the two groups. Use of the balloon resulted in significantly more procedure time (30 min versus 22 min). One patient from each arm crossed over to the other.
The filter group had significantly more new lesions (87% versus 45%), which remained significant when broken down into symptomatic and asymptomatic patients, but not when those over the age of 80 were separated out.
The number of new lesions in the filter group was 3.6 compared with 1 in the balloon group (P=0.0001). Those in the filter arm also had significantly higher lesion volumes (0.59 cm3 versus 0.16 cm3).
There was one minor stroke in the filter group and no adverse events in the balloon group. There were no bleeding or vascular complications in any patients.
The MRI findings were mostly clinically unapparent, Schofer and colleagues said, yet “they are the tip of the iceberg of what is happening to the brain during [carotid artery stenting].”
They concluded that a randomized trial with clinical endpoints would be needed to show whether their findings translate to a lower stroke rate.
The study was limited because it involved one center with a small number of patients. Also, the endpoint demonstrated with MRI is a surrogate rather than a clinical event, and some differences in lesion characteristics may have introduced bias in favor of proximal balloon protection.
The authors have reported that they have no relationships relevant to the contents of this paper to disclose.