Doctors Report Historic Transplant in Child
In a Tissue-Engineering First, Doctors Think the Boy's New Windpipe Could Grow
An Urgent Medical Need Drives a Discovery continued...
That step was important because it cleared away any markers that might have caused Ciaran's immune system to reject the transplant.
Back at Great Ormond Street Hospital, a children's hospital in London, doctors removed stem cells from Ciaran's bone marrow. Stem cells are uniquely flexible cells that can be coaxed to grow into nearly any kind of tissue. The cells were sent to a specialized lab to be purified and returned to the hospital the same day.
After surgeons sewed the stripped-down donor windpipe in Ciaran's chest, they coated it with his purified stem cells. They also injected the tissue scaffold with proteins that encourage cell growth. For good measure, they took tissue samples from Ciaran's own trachea and placed those inside the tube of the windpipe with the stem cells. The tissue samples acted like blueprints, giving the stem cells instructions for what they should become.
The 'Holy Grail' of Tissue Engineering: Organs That Grow
Ciaran's case, which is reported in The Lancet, is the first time doctors have rebuilt an organ inside the body. Normally, donor organs are washed, reseeded with stem cells, and then grown in a lab until they are ready to be used in a patient. The process takes several weeks.
"We did not have the time to engineer and to culture the cells in a bioreactor because this child needed to have something done quickly. We used the child, himself, as a bioreactor," says researcher Paolo De Coppi, MD, PhD, one of the surgeons who treated Ciaran. "For him, there was no other option."
Worldwide, just 12 tissue-engineered tracheas have been transplanted into patients. Ciaran is the first child to get one. Doctors are watching him closely to see if the new trachea will keep up with his growth spurts. Since he's already shot up more than four inches since the operation, doctors think there's a good chance it will.
"We believe the matrix of the transplant will remodel with time. So it should allow, when the child grows, for the transplant to grow with the child," De Coppi says.