His mother, Dorne Lyles, said Tuesday that her son died at Franklin Square Hospital. He was 30. The cause of death is unclear.
Christopher Lyles, a Department of Defense engineer from Abingdon, turned to the surgery after doctors determined a tumor on his trachea was inoperable and he had late-stage cancer.
Dr. Paolo Macchiarini at the Advanced Center for Translational Regenerative Medicine at Karolinska Institute of Stockholm used stem cells from bone marrow in Lyles' back to make the fake windpipe. He had performed similar surgery on a man in Eritrea.
Macchiarini said Tuesday he was saddened by Lyles' death.
"It is a terrible loss," he said.
But Macchiarini said that experimental treatments come with risks and that he would continue performing, and improving on, the transplants. The Eritrean man is still living a healthy life with a synthetic transplant. Macchiarini has been trying to get approval from the U.S. Food and Drug Administration to perform the surgeries in the United States.
Dorne Lyles said that she still has faith in stem cell research and wants people to support it. She said Christopher would have wanted the same.
"We do not want his death to go in vain," she said.
The family also released this statement: "Christopher was a recipient and strong advocate of stem cell therapy. … We hope his bravery will pave the way for further research and development and acceptance of stem-cell-based therapies in the United States."
Officials at HelpHOPELive, a nonprofit that helps raise money to pay for transplants and treatments for catastrophic injuries, said they are seeing more people turn to experimental therapies overseas, particularly those that use stem cells.
"We ask our clients who are seeking experimental treatments to do their research because there are more risks than there may be with a proven procedure where there is more research and a known track record," said Shannon McMonagle, communications manager at HelpHOPELive.
The organization was helping Lyles raise money to pay for his treatment. His family has contributed more than $200,000 to his care and expected total costs to be in the hundreds of thousands of dollars.
Lyles had sought help from many doctors before his brother-in-law discovered synthetic transplants in an Internet search.
In preliminary surgery, doctors removed stem cells from bone marrow in Lyles' lower back. They placed the stem cells in a bioreactor with a Y-shaped scaffold made from plastic polymers commonly used in soda bottles. The bioreactor spun the scaffolding, like a rotisserie chicken in a roaster, as the stem cells fell and fused onto the scaffolding. Over a couple of days, the individual cells grew into real tissue.
In November, Lyles underwent a 12-hour surgery in Sweden, where his mother, sister and brother-in-law traveled to be with him. He came home in January.
Harvard Bioscience Inc., the Massachusetts company that made the bioreactor, said in a statement that it was saddened by Lyles' death. But it said it did not know the cause.
Macchiarini believes synthetic windpipes can save more lives because it's hard to find a donor match for a trachea. Organ recipients also have to take expensive medications so they don't reject their new organs. Macchiarini believed synthetic organs eliminate this need.
Dorne Lyles said she is grateful she still has her son's young daughter, Erin. The family is still trying to get Erin to understand her father's death.