FDA Approves Tiny Device to Prevent Stroke
Wire Mesh Tube May Limit Need for Surgery, Increase Odds of Survival
Sept. 1, 2004 -- Stents, the small metal mesh tubes used to keep blocked arteries open, have already revolutionized care of the heart. Now, they may do the same for the most common type of strokes.
The FDA has approved a stent for use in opening blocked arteries in the neck. The new stent is intended to prevent ischemic strokes by treating blockages in the carotid artery, the main blood vessel leading to the brain.
Ischemic strokes are caused by blocked or narrowed arteries that supply the brain, cutting of blood.
The stent was approved for use in patients who have had symptoms of a stroke or whose carotid artery is at least 80% blocked, and who are not good candidates for the surgical alternative.
"Carotid stents offer doctors a new, less-invasive option for clearing blocked neck arteries," says Lester M. Crawford, DVM, PhD, acting FDA commissioner, in a news release. "This approval is another step forward in the prevention of stroke."
Currently, blockages in the carotid artery are treated with a surgical procedure called carotid endarterectomy, in which surgeons cut into the neck artery to remove the blockage. Patients require general anesthesia for the procedure. An estimated 200,000 Americans a year undergo carotid endarterectomy.
The new system, manufactured by Guidant Corp., is inserted during angioplasty, a less invasive procedure in which the stent is threaded up to the neck artery via a catheter inserted in the groin. Patients usually require only local anesthesia.
The system can be used with a tiny filter that opens like an umbrella. The filter is used to catch and remove the debris that is stirred up during the stenting procedure before it travels to the brain, where it can trigger a stroke.
The FDA approved the system based on a review of studies of safety and effectiveness conducted by Guidant.
The firm studied use of the carotid stent system in 581 patients at 45 medical centers who either had experienced a stroke or were in danger of having one due to severe blockages in the blood vessels in their neck.
The study showed that the new stent system successfully opened blockages in 92% of patients. When complications from use of the stent were compared to complications reported in past studies of patients undergoing surgery, the risk of combined complications of death, stroke, and heart attack at 30 days or stroke in the area of the blockage at one year was about 10% compared with 15% for surgery.
The study also showed that the stent still allowed blood flow to the brain more than two years after the procedure.
The FDA is requiring Guidant to conduct post-approval studies to confirm the stent's performance in more patients and to assess its long-term safety and effectiveness in preventing strokes.