Severe Symptomatic Carotid Artery Stenosis — Endarterectomy or Stenting?

Abstract & Commentary

By Philip E. Stieg, MD, PhD, Professor and Chairman, Department of Neurological Surgery, Weill Medical College of Cornell University; Neurosurgeon-In-Chief, New York Presbyterian Hospital. Dr. Stieg reports no financial relationships relevant to this field of study.

Synopsis: The stroke and death rates at one and 6 months were lower in patients with symptomatic carotid stenosis (> 60%) treated with endarterectomy versus stenting.

Source: Mas JL, et al. Endarterectomy versus stenting in patients with symptomatic severe carotid stenosis. N Engl J Med. 2006;355:1660-1671.

The debate regarding the superiority or non-inferiority of carotid artery stenting performed with distal protection devices as compared to carotid endarterectomy (CEA) continues. This multi-centered, randomized, non-inferiority trial performed at 20 academic and 10 non-academic institutions in France compared the 30-day and 6 month outcomes in patients after carotid endarterectomy or stenting procedures with (> 60%) symptomatic stenosis of their carotid arteries.

The study enrolled patients from November 2000 until September 2005, but was terminated by the Safety Monitoring Committee due to safety and futility issues. A total of 527 patients were randomized into the trial. The primary endpoint was any stroke or death at 30 days; however, data was also collected at 6 months after the procedure was performed. Eligible vascular surgeons had to perform 25 endarterectomies in the previous year and interventional physicians had to perform at least 12 carotid stents or 35 total stents in the supraaortic trunk with at least 5 in the carotid arteries. However, interventional physicians with less endovascular experience could be tutored and mentored through the process. Physician outcome or complication history was not part of the selection criteria for treatment centers. Carotid stenosis was assessed by either duplex Doppler studies and MR angiography or catheter angiography alone. Exclusion criteria included the presence of critical tandem lesions in the carotid territories. Distal protection devices were applied midway through the study. All patients were assessed independently by neurologists, both before and after a procedure was performed.

The 30-day incidence of any stroke or death was 3.9% for CEA and 9.6% for stenting with a relative risk for stenting of 2.5 (95% CI = 2.0 to 7.2). The absolute risk increase was 5.7% for stenting compared to CEA. The 30-day disabling stroke and death rate was 1.5% for CEA and 3.4% for stenting with a relative risk for stenting of 2.2 (95% CI – 0.7 to 7.2). At 6 months, the incidence of any stroke or death was 6.1% in CEA patients and 11.7% of stenting patients. There were more local complications after stenting and more systemic complications after carotid endarterectomy. There were also more cranial nerve injuries after carotid endarterectomy. Of particular note, the cerebral protection device did lower the 30-day incidence of stroke or death from 25% to 7.9%, highlighting its importance. Dual or single anti-platelet therapy after stenting did not significantly impact the results. The mean hospital stay was 3 days after carotid stenting and 4 days after carotid endarterectomy.

Commentary

The debate regarding superiority or non-inferiority of carotid artery stenting with distal protection devices versus carotid endarterectomy is still open. However, this trial clearly supports the advantages of carotid endarterectomy. The trial might have been slightly biased in favor of surgeons given the more stringent entry criteria for that group. However, the authors note that the number of procedures performed by a center and the number of procedures performed by an endovascular physician did not appear to have an influence on their outcomes. This trial, which did not select high-surgical-risk patients, failed to show a difference in myocardial infarction rate between the 2 groups. The impact of distal protection devices is very clear with a 17.1% reduction in stroke and death in the stent group that used distal protection. Moreover, it is unclear to this author what anti-platelet regimen was used in the stent group, and it appeared to vary between institutions. This may have had an influence on the 30-day stroke outcomes. Patient selection and technology will be important issues in future studies.

Careful review of this study and comparison to previous trials regarding carotid stenting versus CEA would lead this author to suggest that the only current indication for carotid stenting is a symptomatic patient with severe stenosis (> 70%) who is a high surgical risk. However, one must also be quite specific about "high surgical risk." At our institution, this would be limited to patients that have severe coronary artery disease who could not tolerate elevations in their systolic blood pressure to 180.