The Maryland man, Christopher Lyles, had an inoperable tumor and required a new trachea. Tracheal transplants are difficult, both due to lack of donors and the possibility of host rejecting the foreign body part. In this case, Dr. Paolo Macchiarini created an artificial windpipe using a synthetic scaffold that was covered in Lyles's own bone marrow-derived stem cells.
The plastic windpipe was then placed in a bioreactor, which allowed the stem cells to grow and form into appropriate cells. Several days later, it was transplanted in Lyles, whose trachea was destroyed while removing the tumor. Photos of the scaffold and artificial trachea are available here.
While the risk of rejection is very low, there could be unforeseen complications with the windpipe in the future. Because this is one of the first-ever transplants of this kind, it is impossible to know how the scaffold and surrounding cells hold up after years of use. This technology holds potential for creating other simple body parts like skin or bladders, but is not yet applicable to complex organs like the heart, lungs, kidney, or liver.
Learn more about new applications for stem cell treatments at the Stem Cells and Regenerative Medicine Congress USA 2012!