Unique method behind transplant of artificial trachea
An article describing the world's first transplant of an artificial trachea seeded with stem cells is published online by The Lancet. A 36-year-old Eritrean patient received the transplant in June at the Karolinska University Hospital. The project was led by Professor Paolo Macchiarini at the Karolinska Institutet, who now continues to improve and extend the regenerative medicine approaches for transplantation to the lungs, heart, and oesophagus.
The patient described in the current article had a tracheal tumour that extended to the lowest 5cm of the trachea along with both bronchi meaning that surgical removal of the tumour alone would not keep the patient alive. The removed section was essential for life and therefore had to be replaced. The tumour had grown to the size of a golf ball and had begun to restrict his breathing, meaning he was quickly running out of time. The operation lasted 12 hours and involved Prof Macchiarini and his team completely removed the affected area of the trachea and replacing it with tailor-made artificial structure.
The scaffold used in this case was prepared at the Karolinska Institutet with help from University College London, UK, who used 3D imaging to scan the patient and then constructed a glass model of the affected section of his trachea to be replaced. The glass was then used to shape the artificial scaffold, before sending it on to Sweden to have the stem cells inserted. There, patient's own stem cells were used to populate the scaffold, turning it into a functioning airway.
Professor Macchiarini believes his technique offers advantages over other methods in transplantation and regenerative medicine. Firstly, by using the patient's own cells to populate the scaffold, there are no concerns over rejection and no immunosuppressive drugs are required. Secondly, since the implant is artificially constructed, it can be tailor-made to the patient's body size and shape. Not only does that mean no human donors are required (often involving long waiting periods), but it means that constructs can be made-to-fit for people (and tracheas) of all sizes, including children.
The team of doctors and researchers have just transplanted a second patient, a 30-year-old man from Maryland, USA, who also had a primary cancer of the airway and had a bioartificial scaffold inserted. This scaffold was made from nanofibres and thus represents a further advance from the transplant that was made in June.
"We will continue to improve the regenerative medicine approaches for transplanting the windpipe and extend it to the lungs, heart, and oesophagus", says Professor Macciarini. "And investigate whether cell therapy could be applied to irreversible diseases of the major airways and lungs."
Tracheobronchial transplantation with a stem-cell-seeded bioartificial nanocomposite: a proof-of-concept study.
Lancet 2011 12;378(9808):1997-2004