Stents, long famous
for their success in propping open clogged arteries
in the heart, are now being used in neck arteries in
an effort to reduce strokes.
Technical advances
have made the stents safer to insert in neck
arteries, and some experts now fear that doctors may
adopt the procedure — and patients may clamor for it
— before there is sufficient research to support it.
With carotid
stenting, doctors insert a mesh device into a
clogged carotid artery in the neck to keep blood
flowing to the brain. The stents can be placed in
the carotid arteries without general anesthesia.
‘‘The procedure is
less invasive and recovery is faster than with
endarterectomy,’’ the traditional surgical approach
to fixing narrowed arteries, said Dr. Marc Mayberg,
executive director of the Seattle Neuroscience
Institute, a research center. But he said carotid
stenting ‘‘may be overapplied in patients who
actually don’t need it, who don’t need any treatment
at all, or who would do well on medications alone.’’
So far, he said,
‘‘there is little scientific data yet to show that
stents are an effective way to prevent strokes,
while there is such data for endarterectomy,’’ which
involves cutting open the arteries and scraping out
fatty debris. Every year, roughly 150,000 Americans
undergo this procedure.
The new procedure
does have a growing number of fans.
Carotid stenting is
clearly ‘‘the coming thing,’’ said Dr. Barry T.
Katzen, medical director of the Baptist Cardiac and
Vascular Institute in Miami. ‘‘We are very excited
about this technology.’’
Although carotid
stenting has been around since the early 1990s, it
is taking off now because engineers have devised a
way to catch debris that can be knocked off artery
walls during insertion of the stent — and could
otherwise travel to the brain and cause strokes.
‘‘We now have
equipment that is much smaller, much more elegant,’’
making the procedure easier and safer, said Dr.
Piotr Sobieszczyk, a cardiologist at Brigham and
Women’s Hospital. ‘‘In the future this may well be
the preferred way of treating carotid artery
blockages.’’
The addition of the
debris filter has been ‘‘crucial to the rapid
development of this procedure,’’ said Sobieszczyk.
Carotid stenting got
another boost last year when Medicare agreed to pay
for the procedure in certain patients.
Despite its promise,
though, stenting will probably not be the first
choice for many people at risk of stroke.
In 2003, the latest
year for which statistics are available, more than
700,000 Americans had strokes and nearly 158,000
were killed by them, according to the American Heart
Association. High blood pressure, smoking, and
clogged carotid arteries are all risk factors for
strokes. Carotid stents are designed to address the
small percentage of strokes that are caused by a
buildup of plaque in the carotid arteries.
While there are not
as much data on stenting as on surgery to prevent
strokes, a major study called SAPPHIRE, published in
2004, did show that carotid stents were just as
effective at reducing strokes in high-risk patients
as endarterectomy and were linked to fewer heart
attacks during the procedure. After three years,
stroke risk in both groups about 5 percent, said
Katzen, one of the study’s authors.
There are risks to
both procedures. The major risks of endarterectomy
include infection and injury to nerves in the neck,
plus bleeding and heart rhythm disturbances; the
major risks of stenting include bleeding from the
artery in the groin through which the stent is
threaded, and heart rhythm disturbances.
On the plus side,
there is preliminary evidence that carotid stenting
may improve cognitive function, said Dr. Rod Raabe,
an interventional radiologist at the Sacred Heart
Medical Center in Spokane, Wash. A study Raabe
presented in March at the annual meeting of the
Society of Interventional Radiology showed a
statistically significant improvement in memory and
other cognitive skills after stenting, even in
patients who had not had strokes.
But the big
outstanding question is this: Should stenting be
used for people at moderate risk of stroke who have
no overt symptoms, like transient ischemic attacks,
also known as mini-strokes. That issue is now being
addressed in a study called CREST funded by the
National Institutes of Health, which is still open
to new patients.
Until that study is
finished, the prudent course, if you’re are at risk
for stroke — because of high blood pressure, being a
smoker, having clogged carotid arteries, or other
risk factors — is to talk with your doctor and try
medications first to reduce your risk. If these
don’t work and you need something more invasive to
keep your carotid arteries open, ask your doctor
about endarterectomy and stents and how much
training your doctor has had in these procedures.
And don’t be afraid to get a second opinion.
Judy Foreman’s column runs every other week. Past
columns are available on
www.myhealthsense.com. Listen to her live
call-in webcast radio show every Wednesday night
from 8:30 to 9:30 EST on
http://www.healthtalk.com.
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