After Linda Packer, a 64-year-old social worker in Manhattan, fell twice over the Memorial Day weekend and felt vaguely unwell, a series of tests revealed a serious problem: one of the two main arteries carrying blood to her brain was more than 80 percent blocked by plaque.
Hers was a fairly advanced case of a condition, known as carotid artery disease, that becomes increasingly common with age and has been linked to 25 percent of the 700,000 strokes in this country each year. It also leads to millions of cases of mini-stroke, memory loss and other brain impairments that interfere with daily life.
Doctors told Ms. Packer her condition was severe enough to justify cutting open the artery to clear out the plaque. Some 150,000 Americans annually undergo such surgery, whose risks include strokes, heart attacks and infections. Until recently, the only alternative was a combination of blood-thinning drugs and blood-pressure medications, and watchful waiting.
But Ms. Packer sought a relatively new, less-invasive alternative called carotid stenting, which has been used on more than 10,000 patients since regulators approved it last year. The technique widens arteries from the inside by threading a catheter through the circulatory system, pressing the plaque into the wall and inserting a metal mesh stent to prop open the artery.
Despite some complications, Ms. Packer is pleased with the results of her procedure. "When it comes to carving up my neck and leaving a big scar I could avoid," she said, "then my vanity comes into play."
But the procedure's seeming ease and its growing popularity have some experts worrying that too many doctors and patients, spurred on by medical device makers, may embrace it without fully understanding that it is generally as risky as surgery - and potentially riskier in some cases.
It is also expensive. Analysts estimate that sales of carotid stents, which cost around $3,000 each, have not yet topped $100 million. But some envision a $1 billion market for the devices within a decade - not counting doctors' fees.
This country now spends about $2 billion annually on surgical treatment of carotid blockages. Both the surgery and carotid stenting procedures cost $10,000 to $15,000. Prominent skeptics include Dr. Mark J. Alberts, a professor of neurology at Northwestern University Medical School. He cites clinical data showing stroke and death rates of more than 10 percent within one year among those getting stents - not much different from the results in the same study for surgery.
Dr. Alberts and some other doctors say that both procedures are done too often and that the advent of carotid stenting seems to be making the problem of over-treatment worse. "There may be a few niche groups of patients that need a carotid stent, but we're already seeing more carotid stents being put in than is justified," said Dr. Alberts, who practices at Northwestern Memorial Hospital, a major stroke treatment center for the Chicago region.
Everyone agrees that clinical evidence about the relative risks in different types of patients is only beginning to emerge. But some clinical studies have found lower complications for both procedures than those cited by Dr. Alberts, with some results seeming to favor stenting and others leaning toward surgery.
And advocates of the technology say that more recent data show that stenting success rates are climbing, now that the systems use temporarily implanted filters to catch bits of life-threatening plaque knocked loose during the procedure. By contrast, they say, carotid surgery - called endarterectomy - has no significant room for improvement.
"We are beginning to see results that make us believers that carotid stents will replace endarterectomy, and that it's only a matter of time," Dr. L. Nelson Hopkins, a professor of neurosurgery and radiology at the State University at Buffalo School of Medicine, said last month at a symposium in Washington.
The trickiest cases involve elderly patients for whom surgery is risky but stenting might be even riskier. Patients older than 80 are more likely to have calcified blockages that are hard to push aside with a stent, and they are more likely to have twisted arteries in which it is harder to implant the stent. Even stenting proponents worry about overuse of the technology in challenging cases.
