Previous transplants of tissue-engineered tracheas have been performed, but the tracheas used on those occasions were taken from organ donors and then reseeded with the patients’ own stem cells. In 2011, my colleagues and I performed an operation that gave a 36-year old male patient a new trachea made from a synthetic scaffold seeded with his own stem cells. The patient had been suffering from late-stage tracheal cancer. Despite maximum treatment with radiation therapy, the tumor had reached approximately 6 cm in length and was extending to the main bronchus. It was progressing and almost completely blocked the trachea. No suitable donor windpipe was available, so transplantation of a synthetic tissue-engineered trachea was performed as the last possible option for the patient. The patient made a full recovery and was discharged from the hospital following the operation.

Synthetic Tissue-Engineered Trachea

The international team that completed the procedure also involved Prof. Alexander Seifalian, PhD, from University College London, who designed and built the nanocomposite tracheal scaffold, and Harvard Bioscience, which produced a specifically designed, shoebox-sized bioreactor that was used to seed the scaffold with the patient’s own stem cells. The cells were grown on the scaffold inside the bioreactor for about 2 days. The scaffold was rotated while its surface was soaked with stem cells obtained from a bone marrow biopsy from the patient’s hip. The patient’s stem cells settled into the pores within the scaffold and began to grow into each other, slowly transforming from individual cells into genuine tissue. A few days after implantation of the new trachea, the patient’s own blood vessels actually started to grow into it, transforming the new organ into a part of his own body. Because the cells used to regenerate the trachea were the patient’s own, there was no rejection of the transplant. The patient was not taking immunosuppressive drugs.

 Exciting Possibilities for Regenerative Medicine

The successful transplantation of tissue-engineered synthetic organs, referred to as regenerative medicine, could open new and very promising therapeutic possibilities for patients who suffer from tracheal cancer or other conditions that destroy, block, or constrict the airway. The procedure that my colleagues and I performed is still experimental and will need to be sanctioned by the FDA for the more than 100,000 Americans who are actively waiting for organ transplants to benefit from it. Another study of the procedure has been performed and is described in detail in the November 22, 2011 issue of the Lancet. I also performed the procedure a second time in a 30-year-old male with a cancerous tumor on his trachea. The surgery was successful, and he is expected to make a full recovery.

“The successful transplantation of tissue-engineered synthetic organs, referred to as regenerative medicine, could open new and very promising therapeutic possibilities.”

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Transplantations of tissue-engineered windpipes with synthetic scaffolds in combination with the patient’s own stem cells, as a standard procedure, means that patients would not have to wait for a suitable donor organ. This would be a substantial benefit for patients because they could benefit from earlier surgery and have a greater chance of being cured. Tissue-engineered synthetic trachea transplants may also be of great value for children in the future, as the availability of donor tracheas is much lower for these patients. If this scenario unfolds, it might mean the start of a new era in the treatment of thousands of patients whose lives and health will be improved.

Paolo Macchiarini, MD, PhD, has indicated to Physician’s Weekly that he has no financial disclosures to report.