Study Of Boston Scientific's Carotid WALLSTENT Monorail Design Shows Superior Safety Results In Stroke Prevention

Main Category: Stroke
Article Date: 21 Jun 2006 - 0:00 PST

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Boston Scientific Corporation (NYSE: BSX) today welcomed the results of a new study, led by Dr. Marc Bosiers of Belgium, demonstrating that the closed cell design of Boston Scientific's Carotid WALLSTENT Monorail provides superior clinical outcomes compared to open cell carotid stents.1 Closed cell stents provide greater plaque coverage of the carotid artery, thereby potentially reducing the risk of a delayed embolism relative to open cell stents. The study was presented at the 60th Annual Meeting of the Society for Vascular Surgery on June 1st by Dr. Joseph Hart , University of Rochester School of Medicine and Dentistry, Rochester, New York, who helped collect the data during his Marco Polo fellowship in Dendermonde, Belgium.

The study compares the clinical results of open versus closed cell carotid stents in 709 patients. At 30-days post procedure, symptomatic patients that received the closed cell stent showed a 4.1 times reduction of stroke, transient ischemic attacks (TIA, a major predictor of stroke) or death - compared to the open cell stent group. The Carotid WALLSTENT Monorail represented more than 70 percent of the closed cell stents used in this study. Closed cell stents, such as Boston Scientific's Carotid WALLSTENT Monorail, have overlapping or fully connecting struts and cover 5 to 10 times more of the vascular wall as compared to open cell stents that have both connecting and non-connecting struts.2

Dr. Marc Bosiers, AZ Sint Blasius in Dendermonde, Belgium, Principle Investigator of the study, commented to the Society for Vascular Surgery, There were less adverse events within 30 days with the closed cell stent. The closed cell stent design offers a greater potential to scaffold and support fractured plaque and keep material that could embolize to the brain, or cause small clots, from traveling through the vasculature. Closed cell stents cover a greater percent of the vascular wall in the stented region and have less uncovered cell area. Therefore we would recommend them for symptomatic patients.

Dr. Bosiers also commented that Patients are most at risk for stroke during the 30 days after a carotid stenting procedure. The Carotid WALLSTENT Monorail demonstrated fewer complications at 30-days compared to open cell stents, likely due to its closed cell design, which offers greater scaffolding and assists in preventing plaque dislodgement.

The study also reported lower rates of major adverse events within 30 days post-procedure in the patient population treated with eccentric filters (non-central axis design), such as Boston Scientific's FilterWire EZ Embolic Protection System, compared to the population treated with concentric (center axis design) embolic protection devices. Filters are used during the carotid artery stenting procedure to protect the patient's brain from damage caused by plaque debris or small blood clots.

In the study, the overall combined 30-day rate of stroke, TIA, or death for open and closed cell design stents was 3.7 percent. The overall rates of stroke or death at 30-days, one year and three years were 1.4 percent, 6.0 percent and 15.1 percent, and restenosis rates were 0.2 percent, 0.9 percent and 5.6 percent, respectively. There was no difference in rates of restenosis (re-narrowing of a previously opened vessel) between symptomatic and asymptomatic patients.

These results should give physicians great confidence when treating their patients with the Carotid WALLSTENT Monorail and FilterWire EZ Embolic Protection System, said Jeff Goodman, President Boston Scientific International. The excellent results from this trial build on the existing clinical evidence for using these devices to treat patients with carotid artery disease and explain why the Carotid WALLSTENT Monorail and FilterWire EZ maintain the number one market share position outside the United States.

Carotid arteries, located on either side of the neck, are the main conduit for blood flow to the brain. When narrowing occurs, patients are at risk for stroke - the third leading cause of death, and the leading cause of disability worldwide.3 Carotid artery stenting is a minimally-invasive procedure in which a stent is delivered to the site of the blockage and expanded to open the carotid artery and restore blood flow.

Boston Scientific is a worldwide developer, manufacturer and marketer of medical devices whose products are used in a broad range of interventional medical specialties. For more information, please visit: http://www.bostonscientific.com.

REFERENCES:
1 Bosiers, Peeters, Hart et al. Do Device Characteristics Impact Outcome In Carotid Artery Stenting? Presented at the 2006 Vascular Annual Meeting, Philadelphia.
2 Boston Scientific bench tests.
3 Link in WHO (PDF)