Anti-Emboli System May Be Preferable in Carotid Stenting

BY TIMOTHY F. KIRN

SCOTTSDALE, ARIZ. -- The flow reversal technique may be a better way to prevent emboli from reaching the brain during a carotid stenting procedure, Dr. Juan Carlos Parodi said at an international congress on endovascular interventions, sponsored by the Arizona Heart Foundation.

At his institution, 200 high-risk patients have been treated to date with the Parodi Anti-Emboli System to create flow reversal, and the 30-day stroke and mortality has been 2%, with no ipsilateral ischemic strokes, said Dr. Parodi, professor of surgery and radiology at Washington University, St. Louis.

Those results are good, but they are not definitive, because clinical outcome is only one way to measure whether a technology is truly intercepting emboli created by the procedure, he said.

Emboli can also be visualized by diffusion-weighted magnetic resonance (MR) imaging and transcranial Doppler. And evidence from imaging studies has called into question how adequate distal protection with a filter may be and has suggested the need for a better method, said Dr. Parodi.

The SAPPHIRE (Stenting and Angioplasty with Protection in Patients at High-Risk for Endarterectomy) trial is the only randomized, controlled trial of a distal filter, Dr. Parodi said, noting that it reported a 30% reduction in 30-day stroke, death, and myocardial infarction with the filter.

But diffusion-weighted MR studies suggest that even with a filter, somewhere between 9% and 43% will still develop new clinical or subclinical lesions, and transcranial Doppler studies suggest that every procedure releases emboli showers, not all of which are caught by a filter.

By comparison, new lesions are seen with the magnetic resonance technique in 6%-12% of patients who have undergone endarterectomy.

How important these small lesions are remains an open question. Dr. Parodi's flow reversal device, the Parodi Anti-Emboli system, uses a balloon inflated in the common carotid proximal to the lesion being treated, obstructing the flow and creating a negative pressure gradient. Then a second balloon is inflated in the external carotid artery for internal carotid procedures to prevent back-flow, and suction is applied.

The device, which was recently sold to W. L. Gore \& Associates Inc., is being refined to give it a lower profile, Dr. Parodi said.