Washington, Nov 28 (IANS) A discovery that grew out of a collaboration between engineers and doctors shows promise in treating peripheral arterial disease (PAD), a common circulatory problem in which narrowed arteries reduce blood flow to the limbs.

The condition is considered a red flag for vascular disease, heart attack and stroke, and its progression can result in the loss of limbs or death.

Now, a team from the University of California-Los Angeles (UCLA) School of Engineering and Applied Science, working with researchers from its David Geffen School of Medicine, is working to develop a PAD treatment device that can prevent thrombosis in smaller blood vessels.

Their research centres on stents that incorporate a material known as Nitinol, a super-elastic nickel and titanium alloy that has the ability to be deformed and to recover its original shape upon heating.

'What we've been doing at UCLA for the last five to 10 years now is working with thin-film Nitinol,' said Greg Carman, professor of mechanical and aerospace engineering and lead study investigator.

'Nitinol, discovered back in the 1960s, is a shape-memory material. They thought it was going to revolutionise the engineering field. It wasn't until 1985 that people began to think this material would probably be great to use in a stent,' Carman said.

'The reason they liked it for a stent is because you could bend the material a very large distance and it would return to its original shape. Other metals, such as surgical steel, do not allow such a large shape recovery and, as such, cannot be used in many stenting devices.'

In the early 2000s, Carman's group started looking into making thin-film Nitinol and accidentally stumbled across a way to fabricate what they believed was very high-quality, uniform-composition Nitinol.

'That's when we started producing thin-film Nitinol. We weren't sure where the applications for this novel, very low-profile material would go until we ran into someone in the medical school,' Carman said.

'I immediately saw the promise that thin-film Nitinol had for intravascular and cardiac applications,' said Daniel Levi, paediatric cardiologist and a principal investigator on the team. 'Greg and I started working together immediately on stents and a heart valve.'

While there are currently several treatments for PAD, including balloon angioplasty, stenting and bypass surgery, devices used in the last two can frequently cause thrombosis, in which clots form inside blood vessels, obstructing blood flow and leading to serious complications.