Partial Heart Transplantation for Severe Pediatric Semilunar Valve Dysfunction

Partial Heart Transplantation for Severe Pediatric Semilunar Valve Dysfunction

The long-term goal of this research initiative is to develop a new valve replacement option for neonates, infants and young children. The central hypothesis is that transplantation of a freshly isolated heart valve will be associated with superior outcomes compared to currently available options, including preserved cadaver valves, bioprosthetic tissue valves, or mechanical valves. This new operation has been named "partial heart transplantation".

The proposed study is a single-center, nonrandomized single arm pilot trial of "partial heart transplantation" in neonates, infants and young children who require semilunar heart valve replacement. This "first in man" trial seeks to determine whether valve replacement using partial heart transplant is feasible and safe. Primary aims are survival one year and five years following the procedure. The hypothesis is that, when compared to historical controls who have undergone homograft valve replacement, those undergoing partial heart transplantation will have equal or superior survival one year and five years following the procedure. Secondary aims are to assess growth and function of the transplanted valve. The hypothesis is that when compared to historical controls who have undergone conventional valve replacement, those undergoing partial heart transplantation will have valve growth that corresponds with somatic growth and superior valve function 1 year following the procedure. Up to five patients will be enrolled in this trial over three years.

Inclusion Criteria:

• Children less than 2 years of age who are referred for a cardiac operation that involves a primary semilunar valve replacement or children less than 2 years of age who are referred for a cardiac operation involves an initial replacement of a previously placed prior homograft, bioprosthetic, or mechanical valve in the aortic or pulmonary position.
• Deemed acceptable for partial heart transplantation based on the standard evaluation process used for orthotopic heart transplantation (see Appendix 1) Insurance approval.
• Written informed consent of both parents/guardians; if there is only one parent/guardian, consent from that individual will be adequate.

Exclusion Criteria:

• Absolute contraindications for orthotopic heart transplantation.
• Severe bilateral long segment pulmonary arterial hypoplasia
• Bilateral pulmonary vein stenosis
• <34 weeks corrected gestational age
• Persistent acidosis with a pH < 7.1
• Diagnosis of immune deficiency.
• Inability for the parent to understand English or Spanish.
• Failure to pass the following psychosocial evaluation:
• The candidate should reside within 4 hours traveling time from Medical University of South Carolina for a minimum of four to six months post-transplantation to assure careful follow-up
• The candidate's family should be capable of long-term supportive care of the child and be able to support the medical needs of the child in follow-up
• Parental (custodial) alcohol and/or substance abuse
• Documented parental (custodial) child abuse or neglect
• Parent (custodian) with cognitive/psychiatric impairment severe enough to limit comprehension of medical regimen
• Infectious Disease Exclusion Criteria
• Evidence of sepsis
• Hepatitis B surface antigenemia
• HIV positivity