- A draft NHS
policy on mechanical thrombectomy as treatment recommends that the
facility be made available round the clock in specialty centers across the
thrombectomy is safe and effective for large vessel occlusion strokes than
previously used intravenous thrombolytic drugs.
- For maximum
benefit of mechanical thrombectomy, patients have to be brought into the centers
within six hours of onset of stroke.
thrombectomy is a treatment that can potentially reverse the devastating
effects of a stroke. It can remove blood clots from the blood vessels of the
brain in acute stroke patients. It thus restores blood flow and prevents or
limits the damage that can be caused by a stroke
thrombectomy devices are being used for clot removal in selected patients in
the United States and Europe.
‘Mechanical thrombectomy is effective in reversing large vessel occlusion strokes when used within a few hours from stroke onset.’
this technique is available only in a small number of units and more so only
during working hours in the United Kingdom. Sanjeev Nayak, a consultant
neuroradiologist at the University Hospital of North Midlands (UHUM) NHS Trust
which uses mechanical thrombectomy, said. "This is one of the top 10 medical innovations of the last decade." UHUM has one of the lowest mortality rates in stroke because of
this new technique.
Facts on Stroke
occurs when blood flow to a particular area of the brain is cut off. As a
result, brain cells are deprived of oxygen and start to die.
that are affected by that particular brain region start deteriorating; examples
are loss of memory and muscle control.
location and severity of stroke will determine how a person gets affected.
strokes may result only in temporary weakness of an arm or leg while larger
strokes can cause permanent paralysis on one side of the body or speech
can be hundred percent if treated immediately but disabilities remain in 2/3 of
are 2 types of strokes -
- When a weakened blood vessel leaks and blood spills into or around the
brain. There is inflammation and pressure build-up, and the brain cells and
tissues are damaged. It is the less common but more fatal kind of stroke.
- When a blood vessel that carries blood to the brain gets blocked by a blood
clot. Hence, blood does not reach the
brain. About 87% of strokes are
ischemic in nature.
When the blood clot (embolus)
the heart or somewhere else in the body and travels up to the brain, it is an embolic
. On reaching the brain, if the clot gets lodged in a small blood
vessel, it can block it completely causing the stroke.
When the blood clot (thrombus)
formed inside one of the arteries supplying blood to the brain it is a thrombotic
. Large vessel thrombotic strokes
that occur in the brain's
larger arteries are more common than small vessel thrombolytic strokes
that occur in the brain's smaller arteries.
An acute ischemic stroke is caused by a
large vessel occlusion
; in other words it is caused by thrombotic or
embolic occlusion of an artery or blood vessel supplying blood to the brain.
Statistics on Stroke
to World Health Organization (WHO) in 2014
, stroke causes 6.7 million
deaths every year
worldwide making it the second most common cause of death
in the world.
that includes disability, illness and
premature death due to stroke is projected to double by 2030.
152,000 patients suffer from strokes every year in the United Kingdom.
Mechanical Thrombectomy Devices
thrombectomy is a endovascular technique
to treat diseases that occur inside blood vessels.
This technique stem from interventional
that use minimally invasive image-guided diagnosis
of diseases in the organs.
techniques have become a preferred and alternative method since they use only
needles and narrow tubes called catheters that are inserted into the body
instead of making large incisions like in traditional surgeries.
In mechanical thrombectomy, the patient is put under
general anesthesia or local anesthesia. A long, thin tube called a catheter is
inserted via an artery (large blood vessel) in the groin. The clot is located
with the help of a cerebral angiography that uses contrasts and x-rays to view
the blood flow in the neck and brain regions.
The catheter is then sent up to the location of the
clot. A clot retrieval device like a wire or a coil is delivered through the
catheter up to the location of the clot and is positioned near the side or
across the target clot. The retrieval device re-assumes its native coil form
when extruded from the catheter. The loops of the coil or wire are deployed
through the clot so as to entangle it or physically break it; the coil and clot
/ clot pieces are then pulled back into the catheter.
thrombectomy is a step ahead in endovascular therapy by bringing along added
benefits of removing clots to enable revascularization (restoring blood flow to
a body part or organ that has been oxygen deprived) of cerebral vessels.
Tony Rudd who is the national clinical director for stroke at NHS England said, "NHS stroke care and stroke survival are now at record levels. We
recognize the potential effectiveness mechanical thrombectomy could have for
about 10% of stroke patients and are drawing up a policy for its possible use
across the NHS".
Thrombectomy is most effective -
- When used within six to eight hours of
onset of acute symptoms
- In patients with large vessel
occlusions when the clots are of cardiac or arterial origin
- In narrowed oxygen-depleted (ischemic)
vessels rather than completely blocked (infarcted) vessels
Benefits of Mechanical
- Can cure the most severe blood clots that
cannot always be broken down by previously used thrombolytic drugs.
- Can bring patients "back to life" who
would have otherwise had the worst outcome.
- Can save millions of pounds or dollars by
treating patients who might otherwise
require a rehabilitation program or lead a life of severe disability.
- Can increase the percentage of people who
can function independently 90 days after a stroke by between 19% and 35%.
this new policy NHS England estimates around 9000 patients to potentially
benefit from it yearly as compared to 500 stroke victims who are currently
benefiting from the procedure.
- Raychev R, Saver JL. Mechanical thrombectomy devices for treatment of stroke. Neurology Clinical Practice. 2012;2(3):231-235. doi:10.1212/CPJ.0b013e31826af206.
- National Stroke Association - (http://www.stroke.org/)
- Interventional radiology - (https://en.wikipedia.org/wiki/Interventional_radiology)
- Endovascular Treatment of Acute Ischemic Stroke - (http://www.cpmc.org/advanced/neurosciences/bulletin/2013/cpni-bulletin-2013-ais-stroke.html)