Abstract 11348: Recapitulation of Human Bio-Scaffold Mitral Valve Growth in the Baboon Model

IntroductionCritical valve disease in the young is limited by the unavailability of small-sized commercial valves and the inability of prosthetic valves to support somatic growth. To facilitate growth, we successfully implanted a bio-scaffold valve comprising of porcine small intestinal mucosa (PSIS) in pediatric patients under compassionate care. However, for full clinical translation, an animal model that can systematically and objectively evaluate the bio-scaffold valve’s growth potential is needed. In the current study, a non-human primate model (juvenile Hamadryas baboon) was selected for PSIS mitral valve assessment in vivo.HypothesisPSIS bio-scaffold mitral valve growth in the baboon will match the human response owing to similitude in cardiovascular anatomy and physiology between the two species.MethodsFollowing IACUC approval, juvenile baboons were implanted with a bi-cuspid PSIS (2-ply thickness, Cormatrix, Roswell, GA) valve in the mitral position. Echocardiography (ECHO) was performed longitudinally post-surgery up to 4 months. From ECHOs, a novel parameter, the normalized aspect growth ratio (NAGR) was defined and computed (Table 1) based on the valve annulus diameter (D), valve leaflet length (LL) and the body surface area (BSA), where NAGR = 1 indicates ideal valve growth. Next, results were compared retrospectively to ECHO performed in pediatric patients who received a PSIS mitral valve replacement.ResultsThe NAGR during the acute phase (up to 4 months following valve replacement surgery) was found to be roughly 1 in both species (Table 1) and was not significantly different (p > 0.05) between the two groups.ConclusionsPSIS mitral valve growth during the acute phase is close to ideal in humans. This response was recapitulated in the baboon model with excellent valve function observed in both species. The current findings suggest that the juvenile Baboon’s cardiovascular anatomical/physiological environment can be used for systematic and objective evaluation of the pediatric human response to bio-scaffold valve replacement. In particular, the valve’s growth potential can be assessed, which would be essential in determining the efficacy of this regenerative strategy.AcknowledgmentAHA award ID - 16GRNT31090009.