AREVOLUTIONARY stem cell treatment is being tested which could prevent sores, ulcers and amputations in people with clogged arteries.

An estimated one in 20 people over the age of 55 in the UK have Peripheral Artery Disease (PAD) which causes poor circulation, usually to the legs.

PAD is the result of atherosclerosis, the build-up of hard deposits on the walls of arteries similar to the scale that forms in water pipes.

Although about half of patients have no symptoms, others suffer varying levels of pain and numbness in the legs and feet.

In severe cases, the condition can produce sores and ulcers caused by poor blood supply to the skin, and even gangrene. Sometimes, the affected limb has to be amputated.

Treatments include cholesterol-lowering drugs and surgical procedures such as bypass grafting and angioplasty. But for up to 12per cent of patients, surgery is not possible.

The new approach being tested in the United States involves injections of stem cells taken from a patient's bone marrow. Stem cells are immature cells which can develop into different kinds of tissue.

Animal studies and laboratory tests have indicated that the injection of bone marrow stem cells, and slightly more developed cells called progenitor cells, into tissues triggers the development of new blood vessels.

Scientists at the Indiana University School of Medicine are in the process of treating 10 PAD patients with stem cells injected into their legs.

Dr Michael Murphy, who is leading the research at the Indiana Centre for Vascular Biology in Indianapolis, said: "We think this is a very promising treatment that could help patients with severe peripheral artery disease for whom there is now no effective therapy."

The patients are receiving one injection before being evaluated for 12 weeks. The researchers will be looking for signs of blood vessel growth and wound healing. However, the primary purpose of the phase 1 trial is to test the procedure's safety.

Studies have shown people with heart disease or at an increased risk of heart disease have fewer blood vessel stem cells circulating in their blood.

The researchers hope the stem cells will "jump-start" blood vessel repair and replacement by stimulating the production of natural proteins that promote growth.

If the study proves a success, the scientists plan a follow-up study next year. Research is also underway to see if the stem cells can be modified to produce more growth before being given to patients.