Intramyocardial Injection of Autologous UCB-MNC During Fontan Surgery for SRV Dependent CHD

Researchers want to better understand what happens to the heart when the autologous (from one's own body) stem cells are injected directly into muscle of the right side of the heart during the Fontan (Stage III) surgery. They want to see if there are changes in the electrical activity, the structure, and the function of the heart following this stem cell-based therapy. Researchers will compare the results from people who receive the stem cells to the results from people who do not receive the stem cells.