Filters May Not Reduce Risks in Carotid Stenting

By Timothy F. Kirn

SCOTTSDALE, ARIZ. -- Cerebral protection devices used during carotid stenting procedures do not catch small emboli and may not prevent stroke and brain damage, according to preliminary results from a study that used diffusion-weighted magnetic resonance imaging.

"Cerebral protection devices may not reduce the incidence of new ischemic defects on diffusion-weighted MR," Dr. Michel S. Makaroun said at an international congress on endovascular interventions sponsored by the Arizona Heart Foundation. "Further investigation is definitely warranted."

Dr. Makaroun presented the results of the first 36 patients treated in a planned larger trial comparing distal-filter protection with no protection; the trial is using MRI of the patients' brains before and after a carotid stenting procedure to visualize lesions that might not be readily clinically apparent.

There was no difference, said Dr. Makaroun, director of the endovascular surgery program at the University of Pittsburgh Medical Center.

Of 18 patients who were treated with cerebral protection, 13 had at least one white lesion seen on diffusion-weighted imaging after the procedure that had not been there before. By comparison, 8 of 18 patients treated without protection had any white lesion afterward. The difference was not statistically significant, given the small number of patients.

The average number of new lesions was the same for both groups, six, and the average size of the lesions was also the same. Two perioperative strokes occurred, one in a patient treated with protection and one in a patient without protection.

All of the stenting procedures were successfully completed, though the protection device could not be used in one patient assigned to the protection group.

The stenting system used in the trial was the RX Acculink System (Guidant), and the protection was the RX Accunet Embolic Protection System (Guidant).