If Medicare agrees to cover it, hundreds of thousands of Americans a year might be able to have an artery-opening procedure and a stent instead of surgery to remove built-up plaque, doctors say. A stent is a wire-mesh tube that props the blood vessel open.
Stents have long been used to fix heart arteries but are approved for use in the neck only for people too sick for surgery. The new study, in people with less severe disease, suggests stents may find much wider use.
"The sea of people is gigantic" who could benefit, said Dr. Walter Koroshetz, deputy director of the National Institute of Neurological Disorders and Stroke, the study's main sponsor.
"We now have two safe and effective methods" to treat neck vessels, said Dr. Thomas Brott of the Mayo Clinic in Jacksonville, Fla. He led the study and gave results Friday at an American Stroke Association conference.
However, the treatments have different complications, and not all doctors are convinced stents are as safe. Three previous studies found they were not, including one published online Thursday by the British journal The Lancet.
The reason: Even though stents prevent strokes in the long run, the procedure itself can trigger a stroke if a bit of plaque travels to the brain.
The new study revealed a tradeoff: Strokes were a more frequent complication with stents, while heart attacks were more common after surgery.
Doctors say which option a patient chooses may depend on their general health, what risks they are willing to accept and how badly they want to avoid surgery.
Surveys show that people worry more about stroke than a heart attack, said Dr. Lee Schwamm, a top neurologist at Massachusetts General Hospital.
"They're terrified of surviving a stroke with major disability ... ending their years in a nursing home," he said.
In the study, "stroke was by far the more disabling complication," said Dr. Wesley Moore, a University of California at Los Angeles doctor who oversaw the surgery part of the study.
About 795,000 Americans each year suffer a stroke. Many are caused by a clot that forms in a narrowed neck artery and travels to the brain. Doctors can check for narrowed arteries by using a stethoscope to listen for abnormal sounds in neck arteries, and a painless ultrasound test can show blockages.
The top treatment has been surgery: with the patient under general anesthesia, the artery is cut open, the plaque removed, and the vessel sewn back together. Stents won approval as an alternative for certain patients in 2004; half a dozen companies make the devices now, although Abbott Laboratories stands to benefit most because its stents were in the study.
To place them, doctors put a tube in a blood vessel in the groin and push it to the narrowed artery. A parachute-like filter is placed to trap bits of plaque that dislodge and keep them from traveling to the brain. A balloon is inflated to flatten the clog, the stent is placed to hold the artery open, and the filter is removed. The patient is awake but sedated.
The study involved 2,502 patients in the United States and Canada. Half had recent symptoms such as a ministroke. The rest had no symptoms but significantly narrowed neck arteries. They were given either surgery or a stent made by Abbott Vascular, a division of North Chicago, Ill.-based Abbott Labs, which helped sponsor the trial.
A month later, about 4 percent of the stent group had suffered strokes versus 2 percent of those who had surgery. About 2 percent of the surgery group had heart attacks compared to 1 percent of those given stents.