The valve in its unexpanded state (left); its expanded configuration in a larger heart (right). (Credit: Sophie Hofferberth, Boston Children’s Hospital; Lara Tomholt and James Weaver, Wyss Institute for Biologically Inspired Engineering)

A breakthrough design could spare children from repeated operations to replace outgrown valves and could also benefit adults with valve defects. The new design could allow children to keep the same prosthetic valve until adulthood. The research team envisions patients having the valve expanded through a minimally invasive balloon catheter procedure as needed.

The researchers mimicked the geometric profile of the human venous valve to design a bileaflet heart valve of programmed dimensions that is adaptable to growth without loss of one-way flow control. Valve prototypes were able to expand to accommodate growth and structural asymmetries within the heart. They remained fully functional across a range of dimensions, pressures, and flow rates.

Because the valve can expand without requiring the frame and leaflet to stretch or enlarge, it is compatible with a range of off-the-shelf materials. The bileaflet heart valve design encourages good blood flow through the valve. This could potentially reduce the risk for blood clots, a complication often seen with existing prosthetic valves.