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.

This Phase I study is a multicenter, prospective, open-label, non-randomized study designed to evaluate the safety, of autologous UCB-MNC delivered into the right ventricular myocardium of subjects with severe CHD defined by single right ventricular dependent circulatory systems at the time of a planned Fontan surgical palliation. This will be achieved by comparing the data collected in the treatment arm to the equivalent data collected in the control arm. The purpose of this non-randomized open-label Phase I clinical study is to prospectively evaluate the safety, as measured by the short-term and long-term safety endpoints and change in baseline comparatives, for the autologous UCB-MNC intramyocardial injections into the single, morphologically right ventricle of subjects with severe CHD requiring Fontan surgical palliation. The treatment group will be compared to an untreated control group.

Eligibility Criteria:
Inclusion Criteria:

* Diagnosis of a congenital hear defect with functionally single right ventricle (such as HLHS, HLHS variants, unbalanced AV septal defect with R dominance, DORV with Hypoplastic LV) undergoing Fontan surgical palliation
* At least 2 and less than or equal to 5 years of age at time of Fontan surgical palliation
* For subjects enrolling in the treatment arm, previous participation in clinical trial Umbilical Cord Blood Collection and Processing for Hypoplastic Left Heart Syndrome patients (NCT01856049) with autologous UCB-MNC product collected and available for distribution is required.

Exclusion Criteria:

* History of DMSO reaction (treatment arm only subjects).
* Parent(s) or legal guardian unwilling to have their child participate or unwilling to follow the study procedures.
* Severe chronic diseases at the discretion of the treating physician.
* Extensive extra-cardiac syndromic features.
* History of cancer.
* Any of the following complications of his/her congenital heart disease:

  * any condition requiring urgent, or unplanned intervention procedure within 15 days prior to Fontan surgical palliation, unless complete and full cardiac recovery is documented by site investigator.
  * severe pulmonary hypertension (reported in the medical record as \>70% systemic pressure)
  * Other clinical concerns as documented by a site investigator that would predict (more likely to happen than not to happen) a risk of severe complications or very poor outcome, not directly related tot he stem cell product or its injection procedure, during or after Fontan surgical palliation.
* Individuals with severe heart failure that requires heart transplantation
* Individuals with refractory or worsening arrhythmia
* Individuals with an automated implantable cardioverter defibrillator (AICD) or pacemaker
* Patient with prior surgical complications during the Fontan surgical palliation that resulted in or could be reasonably expected to significantly decrease cardiac function