FDA. US: The U.S. Food and Drug Administration today cleared for marketing the
ENROUTE Transcarotid Neuroprotection System (ENROUTE TNS), for use
during a minimally invasive procedure to restore normal blood flow to
narrowed carotid arteries. It is the first device designed to access the
carotid arteries through an incision in the neck, instead of the groin,
and uses a blood flow reversal system to capture pieces of the blockage
dislodged during the procedure.
The carotid arteries are two
large blood vessels on either side of the neck that supply oxygenated
blood to the brain. Cholesterol or fatty substances can narrow one or
both of the carotid arteries, causing carotid artery disease. If a piece
of plaque breaks off, it can travel to arteries in the brain and cut
off blood flow, resulting in a stroke. According to the National Heart
Lung and Blood Institute, more than half of the strokes occurring in the
United States each year are caused by carotid artery disease. A person
with the disease may not experience any signs or symptoms until a stroke
occurs.
A severe narrowing or blockage of the carotid artery may
require a physician to perform a minimally-invasive balloon angioplasty
procedure in which a balloon on a long flexible tube called a catheter
is threaded through a patient’s vasculature from the groin to the site
of the blockage, inflated to open the artery and then a small mesh tube
called a stent is placed at the site to keep the artery open.
The
ENROUTE TNS allows physicians to insert a catheter into the artery in
the neck above the narrowed or blocked section of the artery rather than
having to enter through the groin. During the stenting procedure,
physicians typically use a filter or additional balloon to capture and
remove small pieces of debris that might be dislodged and potentially
travel to the brain.
The ENROUTE TNS captures debris by
temporarily shunting blood flowing through the narrowed section of the
artery away from the brain and into a filtering system outside the body.
Blood is then returned to the body though a vein in the leg. Because
the carotid artery branches into many interconnected smaller arteries,
the brain still receives oxygenated blood during the procedure.
“Until
today’s clearance, the only FDA-cleared systems to capture and remove
debris and prevent them from reaching the brain during carotid
angioplasty and stenting procedures required entry into the body through
the femoral artery using an incision in the groin,” said William
Maisel, M.D., M.P.H., acting director of the Office of Device Evaluation
at the FDA’s Center for Device and Radiological Health. “The ENROUTE
TNS provides a minimally-invasive treatment for certain patients whose
tortuous (twisted) or diseased vasculature does not permit access via
the groin for treating their narrowed carotid arteries.”
The FDA
reviewed the data for the ENROUTE TNS through a 510(k) submission, a
regulatory pathway for low-to-moderate risk medical devices that are
substantially equivalent to a legally marketed predicate device that is
not subject to premarket approval. In this case, the FDA found the
ENROUTE TNS to be substantially equivalent to a flow reversal system
currently on the market that uses similar technology and has the same
intended use but is designed to be introduced into the patient through
the blood vessels in the groin.
Data supporting the FDA’s
clearance included the results from a clinical trial sponsored by the
manufacturer. The trial showed that the rate of stroke, heart attack,
and death among the ENROUTE TNS patients was 3.5 percent, significantly
lower than the study performance goal of 11 percent. At least one
serious adverse event occurred in 14.2 percent of patients, including
excessive bleeding or injury at the device access site, low blood
pressure due to the device or procedure, and blood clot formation within
the placed stent. These events are consistent with the type and rate of
serious adverse events associated with other carotid artery procedures.
The ENROUTE TNS is manufactured by Silk Road Medical of Sunnyvale, California.
The
FDA, an agency within the U.S. Department of Health and Human Services,
protects the public health by assuring the safety, effectiveness, and
security of human and veterinary drugs, vaccines and other biological
products for human use, and medical devices. The agency also is
responsible for the safety and security of our nation’s food supply,
cosmetics, dietary supplements, products that give off electronic
radiation, and for regulating tobacco products.