University at Buffalo - The State University of New York

Published: February 5, 2004

By LOIS BAKER
Contributing Editor

Patients who need a second surgery to open a re-clogged carotid artery—the large artery on either side of the neck that serves the brain—face potential major complications, including possible damage to nerves that control eye and tongue movements and stroke.

A new procedure being tested in clinical trials at UB and elsewhere could change that prospect, however.

In findings presented yesterday at the joint annual meeting of the American Society of Neurological Surgeons and American Society on Intervention Therapy Neuroradiology in San Diego, Ricardo A. Hanel, UB neurovascular fellow, reported that there were no neurological complications with the new technique in a study involving 21 patients.

Moreover, the new procedure is carried out from inside the artery, making it considerably less invasive than the established procedure for this condition, called carotid endarterectomy, which involves opening the artery and cutting out the blockage.

"For restenosis (a returned blockage in the same artery), there is no doubt that this is the way to go," said Hanel, who is affiliated with the UB/Toshiba Stroke Research Center and Kaleida Health's Millard Fillmore Hospital, where UB's Department of Neurosurgery is headquartered.

Hanel said that up to 10 percent of patients who undergo carotid endarterectomy after restenosis have major complications, including stroke and death, and up to 17 percent suffer cranial nerve palsy.

"Complications are very low with this procedure in general," he said. "In this small sample, complications were zero."

The new procedure has the cumbersome clinical name "carotid artery angioplasty with stenting (CAS) with distal embolic protection (DEP)." It adapts techniques used widely to open vessels that feed the heart to the arteries serving the brain. L. Nelson Hopkins, III, chair of the UB Department of Neurosurgery, is an international leader in research and clinical trials of this technique.

In this procedure, neurosurgeons thread a slim catheter through the large artery in the groin to the site of the blockage in the neck. Through this catheter, they deploy a tiny filter and position it past the plaque blockage. This filter allows blood to flow through to the brain, but captures pieces of plaque that can break off from the blockage during the procedure, which could clog smaller arteries in the brain and cause a stroke.

Once the filter is in place, the surgeons inflate a balloon to depress the plaque against the arterial wall and open the artery (balloon angioplasty) and then deploy a stent, a tiny wire mesh structure, to hold the artery open. They may inflate a second balloon to further expand the stent inside the vessel. When the procedure is complete, the surgeons retract the filter and its captured pieces of plaque.

UB neurosurgeons have placed more than 1,000 stents in this manner. Hanel said they began using the new technique initially in patients who were not good candidates for a first carotid endarterectomy, such as persons who have had other neck surgeries, additional health complications or a second blocked carotid artery.

During carotid endarterectomy, the artery is clamped at both ends of the blockage, shutting off blood flow. If the remaining carotid also is blocked, the chances of endarterectomy complications are significantly higher, Hanel said. The risk is much lower under those conditions with the new procedure because blood flow is not interrupted.

Patients with restenosis are good candidates for the new procedure because a second endarterectomy is considerably more complicated than the first. Surgeons must work through scar tissue from the first surgery, and the plaque is more prone to breaking apart, often requiring clamping the carotid longer than during the first surgery, he said.

The FDA is expected to approve the new procedure for both primary and secondary carotid stenosis by 2005, Hanel said.

Additional contributors to the study were David J. Padalino, Bernard R. Bendok, Elad I. Levy, Lee R. Guterman and L. N. Hopkins, all of the UB Department of Neurosurgery, UB Toshiba Stroke Research Center and Kaleida Health.