STROKE PREVENTION: NEW BRAIN PROTECTION DEVICE WILL ENHANCE THE SAFETY OF CAROTID ARTERY STENTING

For the prevention of stroke in patients with carotid arteriosclerosis, carotid endarterectomy has been the standard procedure. It is the most commonly performed major vascular operation in the United States: 150,000 cases are performed annually, and 300,000 are performed worldwide.

Recently, endovascular stents (small expandable wire baskets) have been introduced as an alternate treatment of carotid arteriosclerosis. However, use of these stents has been limited by strokes that result when particles are released as the stent expands. Now, vascular surgeons at Montefiore Medical Center in the Bronx, New York are conducting Food and Drug Administration (FDA) approved clinical trials (Montefiore is one of five center in the U.S.) utilizing an innovative brain protection device. These studies are led by Takao Ohki, MD, Director of the Endovascular Surgery Program at Montefiore. The PercuSurge GuardWire device permits a balloon to block the carotid artery during stenting so that released particles cannot get to the brain, but are aspirated and removed. The Montefiore surgeons hope that this novel device may play a key role in how patients with carotid stenosis are treated.

"This new technology may be a better way to treat carotid disease and prevent stroke than open surgery," says Frank J. Veith, MD, Chief Vascular Surgery at Montefiore. "Currently this procedure should be restricted to high risk patients, in whom surgery is extremely difficult or not possible. The introduction of the brain protection system could extend the usefulness of this new technology to benefit low risk patients as well."

Carotid endarterectomy (CEA) although the gold standard treatment, has limitations and various complications, such as peri-operative myocardial infarction, stroke, cranial nerve injury and wound problems, which have been reported at rates ranging between 12% and 21%. Carotid angioplasty and stenting (CAS) has recently emerged as an alternative to CEA. Although good results have been reported concern regarding the safety and efficacy of CAS have been raised, and its general role and comparative value remain unclear. Among the various concerns, the potential of CAS to produce embolic particles that may manifest as a neurologic deficit has been a major concern. One potential solution to prevent embolic events traveling to the brain is the use of a brain protection device that can capture and retrieve these embolic particles. The GuardWire Temporary Occlusion Catheter has an external diameter, which is similar to commonly, used 0.014" guidewires. Its shaft is hollow and it has a flexible, shapable guidwire distal tip. An elastomeric occlusion balloon is located at the proximal end of the distal tip. The GuardWire (with its deflated balloon) crosses the lesion with minimal resistance. Once the lesion is crossed, an inflation device is attached to the proximal end of the GuardWire catheter and the occlusion balloon is inflated with dilute contrast agent. Following inflation of the occlusion balloon, an angiogram is taken to ensure complete occlusion (protection) of the distal carotid artery and to make certain that no embolic material can flow upstream. The inflation device is then removed from the proximal end of the wire while the occlusion balloon remains inflated thus providing coaxial exchange capability to the GuardWire for percutaneous transluminal angioplasty (PTA) balloon and stent delivery catheters. With the occlusion balloon inflated, balloon angioplasty and stenting can be performed to treat the stenosis in the internal carotid artery. The particles that are released during the procedure remain in the proximal carotid artery because of the GuardWire occlusion balloon. Following removal of the angioplasty balloon catheter, an aspiration catheter is introduced over the GuardWire to aspirate the particles.

"If this new brain protection system proves to be effective in preventing released particles from reaching the brain," says Takao Ohki MD, "it will certainly make carotid stenting safer for patients and more widely applicable."