Scientists grow human blood vessels in laboratory

The lab-made blood vessels, which can be stored for up to a year and safely transplanted into any patient, could revolutionise heart surgery, said the researchers behind the breakthrough.

They also claimed the blood vessels could soon replace artificial versions - which easily clog and cause infection - in a number of operations, including thousands of heart bypasses a year, the Telegraph reported.

Scientists have already developed a technique to engineer blood vessels from a patient`s own cells, but this process takes over nine months and patients usually cannot wait that long for surgery.

The new technique, developed by a team at the East Carolina University in the US, involved making the vessels in advance by using random donor cells from human tissue to grow collagen on a biodegradable "scaffold" tube or mould made from a polymer.

When the scaffold dissolves away, fully formed blood vessels are left behind. These are then "washed" of the original human cells so that they were completely benign and unlikely to cause any rejection in the body of a recipient, the researchers reported in the journal Science Translational Medicine.

These vessels have already been tested on baboons and were found to work by fully restoring blood flow. There were no evidence of clogging or thickening when the grafts were removed after six months -an indication that they would be suitable for long term transplantation.

Thousands of people worldwide are diagnosed with heart or circulatory disorders and they could potentially benefit from this new technology each year, the researchers said.

"This new type of bioengineered vein allows them to be easily stored in hospitals so they are readily available to surgeons at the time of need," said study co-author Dr Alan Kypson.

Currently, grafting using the patient`s own veins remains the gold standard. But, harvesting a vein from the patient`s leg can lead to complications, and for patients who don`t have suitable veins, the bioengineered veins could serve as an important new way to provide a coronary bypass.