Design and preclinical feasibility of a pediatric heart valve stent that spontaneously adapts to growth via a spring mechanism.

Congenital heart valve defects often require surgical intervention for survival. Now, there are no valve prosthetics on the market that are designed for babies and toddlers who grow rapidly. Recent advancements in expandable valves hold promise for these young patients but currently require invasive balloon catheter procedures for device expansion. Here, we describe the design and preclinical feasibility of a pediatric heart valve stent that spontaneously adapts to growth via a springlike mechanism imparted by the superelastic properties of nitinol. Studies in piglets demonstrated appropriate constraint of the device to small diameters (8 to 9 millimeters) upon implantation, acute valve function, and the ability of the stent to proportionately expand with growth up to 13 millimeters after 6 weeks without subsequent interventions after implantation. We expect that the growth-adaptive stent concept could be broadly leveraged to eliminate surgeries and invasive procedures as young patients grow.