Doctors at K.U.Leuven perform world’s first vascularized tracheal allotransplantation

A team of doctors at K.U.Leuven have successfully performed a vascularized tracheal transplantation. They were able to repair the complex blood supply to the trachea and to prevent the immune system from rejecting the transplant. This operation, which was presented in the authoritative scientific journal The New England Journal of Medicine this week , has never been completed successfully anywhere in the world before.

Trachea operations are usually carried out to remedy stenosis, or constriction. Constriction of the trachea may be caused by a number of factors: congenital deviations, traffic accidents, long-term insufflations, etc. There are several remedies, such as placing a small tube in the constricted windpipe or placing a cannula allowing the patient to breathe or speak through an opening in the throat. It is possible for patients to survive after such an intervention, but it causes serious discomfort when breathing and speaking. In cases of constrictions that are shorter than 5 centimetres, the constricted section of the trachea is sometimes removed.

In cases of constrictions that are longer than 5 centimetres or constrictions that recur after previous operations, transplantation is often the only viable solution. Such a procedure is, however, not a matter of course. Transplantation can only be considered successful if and when the blood supply to the new organ is restored and if the rejection of the new organ by the immune system is prevented. It is particularly difficult to restore correct blood flow in the trachea, while the correct treatment for preventing rejection is still a topic of debate. Immunosuppressive medications often have severe side effects. In cases of life-threatening conditions that require organ transplants (heart, lungs, liver and kidneys), such side effects are tolerated. However, it is very difficult to justify these side effects where conditions that only improve quality of life, such as trachea transplants, are concerned. There have been a number of attempted trachea transplantations in the past few years, but these were not deemed entirely successful because they failed to restore the blood flow and thus offered no long-term perspectives.

The team from Leuven, led by Professor Pierre Delaere, has managed to solve the two greatest obstacles. They did this by carrying out a ‘double’ transplantation. They first implanted the donor trachea in the forearm of the patient. The transplant’s blood supply was then progressively taken over by the radial blood vessels of the forearm. Once the blood supply was completely restored, the doctors replaced the mucosa of the donor trachea with the patient’s own buccal mucosa.

Immunosuppressive medication was administered for the first few months. However, after the restoration of the blood supply and the partial relining of the mucosa, the transplant trachea was sufficiently recognised as the body’s own tissue. The administration of immunosuppressive medication was stopped completely after eight months and the trachea was transplanted to the neck. The blood vessels that had developed in the forearm were then sutured to the neck vessels. The team has treated two patients successfully thus far, a 55-year-old woman and an 18-year-old man.

This highly significant clinical development is the result of twenty years of intensive research in the field of tracheal transplantations. The first transplantation with complete restoration of the blood supply was made possible through co-operation with a number of departments at the University Hospitals in Leuven: Otorhinolaryngology Head and Neck Surgery, Pneumology, Plastic and Reconstructive Surgery and Thoracic Surgery.