3 February 2011 Last updated at 02:41 ET

Artificial blood vessels keep in fridge until heart op

By James Gallagher Health reporter, BBC News

Artificial blood vessels can now be made and stored

US scientists believe they can produce a ready made supply of blood vessels for use in heart bypass surgery.

A study on baboons and dogs in Science Translational Medicine suggests vessels could be stored for up to a year and used by any patient.

Blood-carrying tubes can already be grown from a patient's own cells, but this takes several months.

UK experts said the research was exciting.

In coronary heart disease, the arteries which bring oxygen to the heart muscle narrow and become blocked. It is the UK's biggest killer.

Every year 28,000 coronary artery bypasses are performed, where blood vessels from other parts of the body are taken and used to "bypass" the blockage.

It is not always possible to use the patient's own blood vessels and several research groups are trying to create artificial ones.

Construction job

The researchers, at the biotech firm Humacyte, the Brody School of Medicine at East Carolina University and Duke University Medical Centre in North Carolina, built an artificial tube-shaped scaffold and added human smooth muscle cells.

As the cells grow they build their own scaffolding out of collagen, and the original structure breaks down.

The researchers then used detergent to kill off the cells so the remaining collagen tube could be implanted in anyone without triggering an immune reaction.

The tubes can be stored for a least 12 months and when used in baboons they were still allowing the blood to flow normally after a six month trial.

It is the combination of storage and that the blood vessels could be implanted into any patient that has the researchers excited.

They said: "Patients have no waiting period for graft production because the grafts have already been created and stored as opposed to custom made grafts for each patient that involve a lengthy waiting time."

Professor Laura Niklason, cofounder of Humacyte, told the BBC: "I think it really takes regenerative medicine to the next level."

"Normally you have to take cells and grow a tissue for one patient at a time, now we can do it on a mass scale, it's a game changer."

Professor John Hunt, UK centre for tissue engineering, said: "It's very exciting you just have to address the safety issues."

"It's a big leap from producing cell-based products for healthy animals for a short time to producing them for unhealthy humans for a lifetime. How do you ensure it lasts for 10 to 15 years, which would be a major advance?"

Professor Jeremy Pearson, associate medical director at the British Heart Foundation, said: "Not everyone is well enough to have a vein taken from another part of their body during heart surgery, so using synthetic veins can become an important part of a patient's treatment. However, sometimes even synthetic veins aren't suitable.

"This study shows that bioengineering can be used to create a novel type of vascular graft that has the potential to improve outcomes for patients. We look forward to the results of clinical trials designed to test this."

The method of engineering blood vessel tissue which can be implanted into any patient could have other applications.

Professor Niklason said: "It can be used for skin, ligaments, cartilage or other simple tissues where it is really the structure, not the cells, which provide the function."

The researchers hope to begin human trials on artificial blood vessels next year.