Doctors Report Historic Transplant in Child
In a Tissue-Engineering First, Doctors Think the Boy's New Windpipe Could Grow
July 25, 2012 -- Ciaran Finn-Lynch is an accidental medical pioneer. With his life in danger, doctors used the 13-year-old's own stem cells to grow him a new windpipe, and they did it inside his body -- a feat that's never been accomplished before.
"It's a really heroic story," says Harald C. Ott, MD, an instructor of medicine at Harvard Medical School in Boston. "They really saved this kid's life."
Ott worked out some of the science that made the procedure possible but was not directly involved in Ciaran's treatment.
Two years after the surgery, doctors say Ciaran (pronounced KEER-an) is living the life of a normal teen. He's grown more than 4 inches and gone back to school. Best of all, he has no need for an expensive and complicated regimen of anti-rejection drugs.
What doctors are learning from his case could help thousands of children born each year with life-threatening birth defects.
An Urgent Medical Need Drives a Discovery
Ciaran was born with a windpipe so small and deformed that it caused his lungs to collapse.
Doctors managed to hold his airway open using metal tubes. But eventually the tubes eroded into his aorta, the large vessel that carries blood out of the heart. He was rushed to the hospital with massive bleeding. Twice.
The second time, the bleeding stopped on its own. That gave his doctors a small window of time to look for other options.
Two years earlier, scientists had devised a new way to create organs using a patient's own stem cells. Though the technique had only been tried in adults, they thought the same method might work for Ciaran.
Working quickly, his doctors located a trachea, or windpipe, removed from a 30-year-old Italian woman whose organs were donated after she died. The trachea was about the same size and shape needed to replace the deformed one that Ciaran was born with.
Scientists in Italy cleaned the organ of all its cells using a method discovered at Harvard Medical School. Working with a detergent found in shampoo, they were able to strip the cells away from the protein scaffold they grew on. It's a bit like remodeling a house by first tearing it down to the studs.
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.