Blood clot grabber could save stroke victims' lives
Strokes kill around 200 people every day in the UK
A device that ‘traps’ blood clots so they can be safely removed from the brain could be a radical new treatment for stroke.
The cage-like gadget ensnares the clot, allowing doctors to retrieve it so blood flow can quickly be restored.
Strokes kill around 200 people every day in the UK, and it is estimated the NHS spends 2.3 billion a year treating and looking after the 100,000 people annually struck down by the life-threatening condition.
Around 85 per cent of victims are
affected by ischaemic strokes, where a clot travels to the brain and
shuts off its blood supply.
The rest suffer haemorrhagic strokes, where a blood vessel bursts in the brain, causing potentially fatal bleeding.
current treatment guidelines, ischaemic stroke victims are treated with
a clot-removing drug called tissue plasminogen activator.
this is only really effective within the first three hours after a
stroke, after which a clot may be too hard and well-developed to break
up with drugs.
the experimental new gadget, called the Solitaire Flow Restoration
Device, could potentially be used long after the three-hour cut-off
point because it can force its way through the clot.
First a tiny tube is inserted into an artery in the leg and, using X-ray images, fed up through the body until it reaches the clot.
A collapsible metal cage attached to the end of the tube is forced through the centre of the blockage and then sprung open at the push of a button.
The cage instantly expands, trapping the clot in its metal frame.
Doctors then slowly pull the loaded cage until the clot is safely drawn into the tube, before being removed from the body.
Although similar clot-busting machines have been developed in recent years, most tend to ‘smash’ the clot into pieces before retrieving them.
This raises the risk that fragments of the clot could travel deeper into the brain and simply cause another blockage that may be even harder to reach.
The Solitaire Flow Restoration Device successfully restored blood flow in 61 per cent of patients in a recent study
The Solitaire avoids this risk by extracting the clot in one go.
New research carried out at the University of California, in Los Angeles, compared this device with a clot-busting machine already approved for use in the U.S. by the Food and Drug Administration.
This device, called the Merci retriever, uses a corkscrew-shaped tip to drill into the blockage before removing it.
The study involved 113 patients, with half having the Solitaire treatment and the other half the Merci.
The results, presented at the recent American Stroke Association annual conference in New Orleans, showed the Solitaire successfully restored blood flow in 61 per cent of patients, compared with just 24 per cent for the corkscrew device.
Three months after treatment, the mortality rate in the Solitaire group was 17.2 per cent, compared with 38.2 per cent in those treated with the Merci device.
The latest device is still in trials and is unlikely to be available in the UK for at least two to three years.
Professor Kennedy Lees, an expert in stroke treatment from Glasgow University, said the Solitaire device looked promising, but stressed there is no proof yet that using it, or similar devices, several hours after a stroke leads to a good recovery.
‘It’s potentially very useful,’ he said, ‘but it needs to be fully tested because it may be that restoring blood flow so late on has no clinical benefit.
‘In addition, these devices do carry some risk of bleeding if they cause injury to the blood vessels.’