High-speed drill zaps fat from your arteries
Daily Mail
By ROGER DOBSON -
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Last updated at 21:41pm on 21st May 2007
A tiny steel device that vibrates inside arteries at 20,000 times a
second may be an alternative to bypass surgery.
At less than 1mm wide, the device breaks through solid blockages
in arteries, flushing them out and helping to restore blood flow,
which eases pain and other symptoms.
It is aimed at patients with chronic total occlusion, or CTO,
where an artery has been completely blocked for at least 30 days.
CTOs develop over time as plaque build-up thickens on the
arterial walls, ultimately closing off the artery completely,
resulting in chest pain.
They are found in up to a third of patients who have tests for
heart disease. They also occur in the legs and can lead to
amputation.
Successful re-opening of the artery usually results in
improvement of symptoms and significant reduction in the need for
bypass surgery.
Results from a trial of the device, which is expected to be
available for use in the UK later this year, shows it helped to open
up blockages in around seven out of ten patients.
Currently, CTO patients can be treated with drugs, bypass surgery
or angioplasty to break through the blockage.
Drugs like beta blockers relieve angina by decreasing heart rate
and lowering blood pressure, but don't usually eliminate all
symptoms. Bypass surgery carries risks, including bleeding and
infection.
Angioplasty involves pushing a wire through the blockage and
inflating a balloon to keep it open. Success rates can vary from 30
to 90 per cent.
However, there can be problems with the wire perforating the
artery, which can occur in up to one in six cases.
The idea behind the new device - the Crosser - is that instead of
cutting its way through the blockage, it uses vibrations to break
through.
Researchers say it works like a mini pneumatic drill, peeling
back layers of the blockage as it moves along.
The system, which is operated by a foot pedal, consists of a
generator, catheter and stainless steel vibrator. The vibrator and
catheter are manipulated down the artery.
The generator then produces a high-frequency current which is
converted into mechanical vibrations that travel down a wire within
the catheter to the stainless steel tip of the Crosser.
High-frequency vibrations also create bubbles in the surrounding
fluid of blood and saline. These expand and implode, producing
liquid jets that help to destroy the CTO.
Results from two trials show the device can be highly effective.
In one, the success rate for destroying the CTO and restoring blood
flow was 76 per cent, and 63 per cent in the other.
Historically, the success rate for treating patients in the
second group is as low as 30 per cent.
"These are tough blockages," says Mark Page, of the developers
FlowCardia. "But the evidence is overwhelming that opening them is
very beneficial to long-term survival.
"Once patients have a CTO, they have three options. Over half get
drugs for the pain. A lot of these patients move over time into the
two other categories - bypass surgery in the heart or legs, or
catheter treatment.
"Our device is a safe and effective option designed to keep
people whose pain can't be dealt with by medicines any more, away
from bypass surgery.
"It is effective about two-thirds of the time in the heart and
more than 80 per cent in the legs."
In most cases, once the blockage is cleared, a small mesh tube,
or stent, is put in place in the artery to keep it open.
The device, which has been approved for use with CTOs in coronary
and leg arteries, could be available in the UK later this year or
early next.
• For more information, visit www.flowcardia.com
