Fishing for blood clots: Tiny metal net dramatically reduces stroke deaths
Tiny wire net expands inside blood vessel 'catching' the clotResearchers say it can effectively reverse a stroke while it is happening
15:56 GMT, 27 August 2012
Doctors could soon be using small nets to retrieve blood clots from the brains of stroke patients, according to researchers.
Around four in five strokes occur when blood clots block a blood vessel to the brain, starving it of oxygen. They are a medical emergency that can cause paralysis and death.
The most common treatment involves taking a drug that dissolves the blood clot, causing the artery to reopen and restoring blood flow.
The Solitaire is threaded through the artery until it reaches the clot (top). It is then deployed and takes hold of the clot (bottom)
However, the drug is only effective if taken within three hours of the onset of stroke. It also frequently fails to dissolve large blood clots which are responsible for the more disabling strokes.
Now, a team have tested a new device that is sent through an artery in the leg up to the brain. When it reaches the clot the tip expands into a tiny stent-like metal cage or net, which grips and traps the clot before it is extracted.
The Solitaire device has yielded promising results in a recent medical trial at the University of California, Los Angeles.
Researchers compared this device to another 'clot retriever' known as the Merci in a double-blind trial of 113 patients.
More than half of the patients treated with Solitaire (58 per cent) were judge to have good mental and motor functioning three months later. This compared to just one third of those treated with Merci. Also only 17 per cent of those treated with Solitaire died following treatment compared to 38 per cent treated with the Merci.
Another study in 178 patients showed patients treated with Solitaire had almost double the chance of living independently after treatment.
Dr Jeffrey Saver, director of the UCLA Stroke Center, said: 'The Solitaire heralds a new era in acute stroke care.
'It allows us to be much more successful in opening arteries and saving the threatened brain.'
He added that the device could effectively reverse a stroke while it is happening.
'When a blood vessel gets blocked, brain nerve cells can survive for minutes or hours. If we can restore blood flow rapidly, we can save brain cells.'
The Solitaire won approval in the U.S from the Food and Drug Administration for use as a clot retriever in March 2012.