Human trials of artificial artery


Professor Hamilton with the artificial artery

An artificial artery is set to be tested in human trials early this year. London's Royal Free Hospital used nanotechnology to develop the small bypass graft from a polymer material.
The material enables the graft to mimic the natural pulsing of human blood vessels, which enables them to deliver nutrients to the body's tissues.
The ultimate aim is to use the graft in coronary artery and lower-limb arterial surgery, which doctors say could reduce amputations and heart attacks.
If the trials - funded by a grant of £500,000 - are successful, the device could potentially help thousands of patients with vascular disease.
The wall of the artery is designed to be able to withstand blood pressure throughout a person's lifetime and is normally very strong.
If it is damaged by disease such as hardening of the arteries, the artery can become blocked or in some patients the wall can weaken, becoming an aneurysm, and it may rupture.
We will be able to reduce heart attacks, reduce amputations and ultimately save lives


Professor George Hamilton
Royal Free Hospital

The current surgical treatment is to bypass or replace the damaged vessel using a plastic graft or preferably a vein taken from the patient's own leg.
But many patients do not have suitable veins.
The plastic grafts were originally made with the same nylon used to make "drip-dry" shirts.
But although they work well for larger grafts, they are less successful for grafts of less than 8mm.
This is because these materials cannot pulse and their surfaces stimulate clotting of the blood in the graft.
Lives lost
Researcher Professor George Hamilton said: "There is a high failure rate using these rigid, small diameter bypass grafts.
"Many patients who have needed smaller bypass grafts, but have not had suitable veins, have had limbs amputated and some patients unable to have coronary bypass surgery have had heart attacks and died."
The new artificial artery has been designed to mimic the natural version as closely as possible.
It is strong, flexible, resistant to blood clotting and pulses rhythmically to match the beat of the heart.
Using nanotechnology, the researchers incorporated specific microscopic molecules into the graft.
Some aid circulation, while others encourage specialised stem cells to coat its lining, boosting its ability to repair damaged blood vessels still further.
Professor Hamilton said: "This will be hugely beneficial to patients in the NHS as we will be able to reduce heart attacks, reduce amputations and ultimately save lives."
In the long-term, the team hope to develop a range of "off the shelf" grafts, stents and other devices.
Judy O'Sullivan, of the British Heart Foundation, said: "We welcome this interesting development which could potentially be of enormous benefits to patients who need a bypass operation to treat their coronary heart disease.
"The availability of suitable artificial arterial grafts would mean that more patients could benefit from the bypass operation whilst avoiding having a wound following removal of a patient's own veins or arteries to be used as grafts, as current practice requires."


http://news.bbc.co.uk/1/hi/health/8435879.stm