Doctors rebuild windpipe using boy's own cells

A BRITISH boy has had his windpipe rebuilt using his own stem-cells in a groundbreaking operation by surgeons in the UK.

The ten-year-old had the nine-hour surgery on Monday at Great Ormond Street children's hospital in London.

If successful, doctors believe the technique could lead to a revolution in regenerative medicine, with costs falling enough to be affordable for the NHS.

The procedure involved taking stem cells from the boy's bone marrow and injecting them into the "scaffold" of a donor trachea, or windpipe, which had its own cells removed. The organ was then implanted into the boy.

Over the next month doctors expect the stem cells to begin transforming themselves within the boy's body into tracheal cells.

The boy, whose identity has not been revealed, is said to be doing well and breathing normally.

Because they are derived from his own tissue there is no danger of the newly grown cells triggering an immune response and being rejected.

The procedure was a big step forward from the pioneering surgery conducted in Spain two years ago on 30-year-old mother-of-two Claudia Castillo – the first person to receive a transplant organ created from stem cells.

Ms Castillo was given a section of tracheal airway rebuilt from stem cells, but using a much more complex and costly process.

On that occasion doctors grew the new tissue outside the body by rotating the donor graft in a special "bioreactor" before transplanting it into the body.

In the boy's case, the windpipe was treated with a carefully mixed cocktail of chemicals designed to trigger signals that would allow the tissue to grow in the body.

Professor Martin Birchall, head of translational regenerative medicine at University College London, said: "This procedure is different in a number of ways, and we believe it's a real milestone.

"It is the first time a child has received stem cell organ treatment, and it's the longest airway that has ever been replaced. I think the technique will allow not just highly specialised hospitals to carry out stem cell organ transplants.

"Now we need to conduct more clinical trials to demonstrate that this concept works. We'd like to move to other organs as well, particularly the larynx and oesophagus."

Preparation of the donor organ was carried out in the Great Ormond Street operating theatre by stem cell pioneer Professor Paolo Macchiarini, from Careggi University Hospital in Florence.

Prof Macchiarini led the Italian, British and Spanish team behind Ms Castillo's transplant.

He was contacted by British doctors after they ran out of options for helping the boy, who was born with a rare condition called long segment tracheal stenosis.

At birth the boy had a windpipe measuring just one millimetre across and was unable to breathe.

Attempts were made to patch up his trachea and hold it open with supporting "stents".

But eventually the stents eroded, damaging the aorta, the main artery taking blood out of the heart.

The boy was yesterday said to be recovering well and talking from his hospital bed.

Prof Birchall said that, since Ms Castillo's operation, the cost of the procedure had fallen from "millions of pounds" to "about 10,000".

He added: "We don't think it's going to replace conventional transplants just yet, but already there are certain aspects of conventional transplant surgery it can be applied to."