Growth-accommodating pulmonary valve implant for children
Sophie-Charlotte Hofferberth, MBBS
BACKGROUND: Tetralogy of Fallot (ToF) is the most common cyanotic congenital cardiac defect, affecting nearly 10% of all children born with heart disease. The hallmark of ToF is severe narrowing of the right heart structures and pulmonary valve stenosis, necessitating surgical correction in early infancy.
GAP: Although operative survival has improved significantly, contemporary surgical repair of ToF remains a non-curative procedure as current techniques fail to preserve pulmonary valve function. Most children develop early-onset pulmonary valve insufficiency, leading to dilation and adverse remodeling of the right ventricle. As a consequence, thousands of repaired ToF patients are at risk of serious late complications, including ventricular arrhythmias, biventricular dysfunction and sudden cardiac death. The purpose of this study is to address the urgent unmet clinical need for a suitable pulmonary valve replacement device for infants and young children.
HYPOTHESIS: An expandable pulmonary valve replacement device with a dynamic, size-adjustable geometric configuration has the capacity to maintain function over a wide range of diameters, and thus accommodate somatic child growth.
METHODS: 1) Computer modeling of valve frame and leaflet geometry; Benchtop evaluation of valve geometry; Mechanical testing of valve leaflet materials.; 2) Valve prototype design; in vitro testing of valve prototype in mock circulatory flow loop.
IMPACT: Preservation of pulmonary valve function from the time of primary surgical repair in infancy would represent a paradigm-shifting advance in the treatment of children with ToF. Moreover, development of growth-accommodating heart valve technology ultimately stands to benefit all children requiring valve replacement early in life.