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View Full Version : The artificial ‘spiral’ vein that may mean new life for millions


abdulhakeem
14-03-07, 06:20 PM
March 13, 2007Shirley English

A revolutionary artificial vein, invented by three NHS doctors, could offer hope to millions of people suffering with clogged arteries.

Results from human trials into the new plastic vein — which is being developed for use in bypass operations — have shown a 100 per cent success rate in the first six months.

The artificial artery is different from those currently in use because it is “rifled” inside, like a gun barrel, and encourages blood to spiral as it moves along.

Until recently it was assumed that blood flowed in a straight line, and artificial veins were manufactured with smooth insides to reflect that. However, in 1991, Peter Stonebridge, of the University of Dundee, discovered that blood corkscrews as it flows, causing less friction or damage to arteries and helping to clear away potential blockages. He published his findings in The Lancet scientific journal. Since then, with the help of two other doctors and £6 million of public and private investment, he has developed an artificial vein to mimic the natural spiralling movement of human blood.

According to Professor Stonebridge, the simple adjustment from a smooth to a “rifled” vein has produced “remarkable” results in human trials led by researchers at Ghent University Hospital, Belgium.

The findings represent a breakthrough in the future treatment offered to the 10.7 million people in Western Europe who suffer from peripheral arterial diseases, including those that lead to amputations, heart attacks and strokes.

Professor Stonebridge set up Tayside Flow Technologies with John D*ck and Graeme Houston, from Ninewells Hospital in Dundee, to develop the product. He said yesterday: “One would have expected some of the bypass grafts [artificial veins] in the trials to have failed, but none have. They are all still going which is remarkable.”

Currently, seven out of ten “smooth” artificial arteries used in below-the-knee bypass operations fail in less than two years and about 40 per cent of patients need a limb amputated. On that basis, approximately 20 per cent of the new “spiral” veins implanted into the legs of 22 trial patients should have stopped working after six months.

But so far all the grafts have stayed open and bloodflow speed has remained constant, researchers say. Professor Stonebridge said: “We have spent millions on proving the technology and developing techniques that are totally new. This is a big step forward.”

Tayside Flow Technologies, Scotland’s first “spin-out” company from the NHS, plans to continue trials for a further six months, but needs a further £6 million to start manufacture. The global market in grafts and stents is worth $300 million (£155 million).

Scottish Enterprise and Sir Tom Farmer, the Kwik-Fit founder, have pledged continued support, and European investors have expressed interest, but a UK backer is sought.

In recent years the Government has become aware of the business potential of NHS staff expertise. Nine government-funded “innovation hubs” now operate in England and Wales to develop and commercialise the ideas and inventions of NHS staff, while Scottish Health Innovations Ltd (SHIL) does the same job in Scotland.

Cameron MacDonald, of SHIL, said: “The NHS is the biggest source of untapped intellectual property anywhere. You have a large body of skilled, highly trained, competent problem-solvers, but there were no real means of taking that forward until now.”

How it works

-The new artificial vein mimics naturally occurring spiral laminar flow (SLF) of blood in healthy human arteries


-The spiralling motion is started by the pumping action of the heart and continues in human veins, which expand and contract and also twist slightly to ‘spin’ blood as it flows around the body


-SLF evolved in humans as the most efficient way of transporting blood, because it reduces turbulence and friction in arteries, causing less damage. It also naturally sweeps


-In diseased veins, caused for example by smoking, obesity and diabetes, the spiralling motion breaks down and veins become sluggish. Blockages then occur that cause areas of turbulence in the vein and result in pain


-The new artificial vein, used in bypass operations to replace diseased sections of vein, is a plastic tube with an internal groove that encourages blood to spiral again


-Because the new vein makes blood spiral, the implant suffers less friction and less damage. As a result the implants are expected to have a lifespan of at least twice as long as smooth artificial veins currently in use
http://www.timesonline.co.uk/tol/news/uk/health/article1505726.ece

abdulhakeem
14-03-07, 06:24 PM
Artificial vein to boost surgery

Wednesday, 14 March 2007

Scientists are developing an artificial vein for use in patients with circulation problems.

The device, which encourages blood to flow in its natural spiralling fashion, has produced highly promising results in clinical trials.

The developers hope it will offer surgeons carrying out bypass operations an alternative to relying on blood vessels taken from the patient's body. It is hoped it could be made available to patients within a year.

In theory the device could help millions of people who suffer from peripheral arterial disease.

The condition develops when fatty material builds up, and begins to narrow the blood vessels.

It can lead to serious mobility problems and, in very severe cases, the need for limb amputation.

Synthetic grafts have been developed for use in operations to bypass clogged blood vessels.

However, many get clogged up with fatty deposits themselves, and often fail within two years.

As a result, surgeons tend to rely on taking blood vessels from elsewhere in the patient's body to do the job.

Blood flow

The new device has been developed by Dr Peter Stonebridge and his colleagues at Ninewells Hospital in Dundee.

Dr Stonebridge used sophisticated imaging equipment to prove that blood does not flow in a straight line, but rotates in a corkscrew fashion through the blood vessels.

He then used this knowledge to develop a vein made out of a polymer called ePTFE which encourages blood to move in this natural corkscrew fashion because it has a grooved interior like a gun barrel.

In theory, this should help reduce wear and tear, clean away blockages, and cut the risk that the vein will get clogged up.

Tests on 22 patients in Holland and Belgium showed the vein not only encouraged a healthy blood flow, but also remained fully open a year after they were fitted.

One 73-year-old female patient who had very limited movement, and night cramps is now able to walk again following surgery.

Quality of life

Dr Stonebridge and his colleagues have formed a company, Tayside Flow Technologies, to develop the vein, and similar stent devices which could be used to open up blocked blood vessels.

Antony Odell, the chief executive officer, said: "If this graft works in the way we think it is going to, then it will help to improve the quality of patients' lives."

Professor Gianni Angelini, an expert in cardiac surgery at Bristol University, said a reliable artificial vein would be a "terrific improvement".

He said at present, most operations relied on taking blood vessels from the patient's body.

"If you could just take something off the shelf, then that would be a lot easier, and cause less trauma to the patient," he said.

However, he said follow up studies were required to prove that the device remained fully functional in the long-term.

http://news.bbc.co.uk/2/hi/health/6449715.stm