She spent months in an intensive care unit, with a tube down her throat to help her breathe. This damaged her windpipe, or trachea, to such an extent that doctors placed a mesh tube inside it to keep it open and allow her to breathe properly.

"I had fever and felt out of breath all the time," recalls De Croock, now a 54-yearold mother of two. “I was so tired I had to lay down half of the day." The mesh tube, or stents, caused permanent infection, so De Croock had to take high doses of antibiotics. Also, she coughed profusely because mucus accumulated in her throat.

In 2006, she desperately searched the internet for solutions and found Professor Pierre Delaere, a specialist of head and neck surgery at the Gasthuisberg Hospital of the Catholic University of Leuven. For more than 20 years, Delaere has been investigating efficient ways to reconstruct the trachea and larynx – the cartilaginous structure at the top of the trachea that contains the vocal cords.

"Originally, I suggested to Linda a straight reconstruction, using her own tissue," the surgeon explains. But doctors feared her trachea was too damaged, and she would not have enough healthy tissue available. "The danger was that if we took out the stents, everything collapsed. We couldn't afford to make her worse." Delaere needed a plan B: a trachea transplant.

The genius idea

Organ transplantations are nothing new. But unlike organs such as the liver or the heart, the trachea does not come with a large blood vessel, so reconstructing the vital blood supply is a tricky affair.

That is where the unusual idea came in: transplanting the donated trachea into the patient's forearm first. There, large blood vessels and a thin, well-vascularised tissue under the skin would help the trachea restore its own blood supply. It would then be ready to be implanted in place of the damaged bit.

Professor Delaere's team had tested this new procedure in rabbits. When he suggested to try it out, De Croock was not put off. "This was my only solution," she explains. "I trusted the professor." So the Flemish woman Aalst became the world's first patient to undergo this pioneering kind of tracheal transplantation.

A peculiar procedure

De Croock carried the donor's trachea in her left forearm for eight months; it was a bit painful, but she had no problem in her day-to-day activities, such as eating or getting dressed. When the trachea had grown a good blood supply and enough of her own mucosal lining, Professor Delaere traded her damaged windpipe for this new, healthy one.

Like with any transplantation from a donor, De Croock had to take immunosuppressant drugs to prevent her body from rejecting the graft. She has now been off the medication for more than a year, so it is safe to say that the operation was a success. Her voice is normal, and she can travel and play light sports. "I feel good," she says. "Every day I am happy when I realise that I can breathe normally."

Delaere, meanwhile, has already repeated the operation. An 18-year-old Flemish man only had to keep the donated trachea in his forearm for six weeks, so the whole process was shorter (and, hence, cheaper) this time around. The surgeon hopes to refine the procedure with more operations and study the long-term outlook. Hopefully, other patients the world over will be able to benefit from the technique, too.

www.kuleuven.be/cltr/en/allo/index.htm

Organ donations in Belgium

Linda De Croock was put on a waiting list for several months until a compatible donor was found because the demand for organs is higher than their supply.

If you are a Belgian national or have lived in Belgium for more than six months, the law allows the removal of your organs after your death unless you have previously stated your refusal or if your immediate family objects to it.

You can find out more and download the organ donation form at

www.belgium.be/en/health/organ_donations

Any other options?

Scientific research has other tricks up its sleeve, but not all are fit for the tracheal case – yet!

Why not make some artificial tissue?

Of course, it would be fantastic to create a man-made trachea so we could have a brand new organ without relying on organ donations. However, the tracheal cartilage has a very specific structure. According to Professor Pierre Delaere, who performed the groundbreaking surgery, it is difficult to reproduce the material and its elasticity, as well as the protective layer with its blood supply. More work to come for tissue engineers.

How about stem cells?
Could we not grow a new trachea from them?

In 2006, a team from Barcelona performed a tracheal transplant on a young woman who had suffered from tuberculosis. They kept only the donor's cartilage and removed the donor's cells on the surface. Then, they grew a mucosal lining in the lab, using stem cells from the receiving patient. Because these were the patient's own cells, she did not take any immunosuppressant therapy. This procedure was spectacular, but the long-term outlook remains to be confirmed. Professor Delaere notes that no blood supply was restored. Also, the area transplanted was further down the windpipe, in the bronchus area.