Exactly what happens to the windpipe after it is transplanted is n't clear , but researchers believe that placing stem cells , which are capable of developing into different types of body cells , can pick up signals from their environment and integrate with existing tissues . Hannah has spent the first two years of her life in the intensive care unit . A year after her windpipe transplant , the patient is mostly breathing on her own . She was the youngest and first to receive this transplant in the United States .
Hannah has spent the first two years of her life in the intensive care unit . A year after her windpipe transplant , the patient is mostly breathing on her own . She was the youngest and first to receive this transplant in the United States .