A geometrically adaptable heart valve replacement

A biomimetic prosthetic heart valve is geometrically adaptable to accommodate somatic growth and structural asymmetries within the hearts of sheep. Room to grow Children with congenital heart disease requiring valve replacement often must undergo multiple surgeries because the replacement valve cannot grow as the child’s heart grows. To accommodate large changes in blood volumes without compromising tight leaflet closure, Hofferberth et al. developed a prosthetic valve that mimics the geometry of the human venous valve. The prosthesis, composed of polymeric leaflets attached to a stainless steel stent, was mechanically expanded using transcatheter balloon dilation to adapt to larger fluid volumes. Size-adaptable valves supported forward fluid flow without leaking in flow loops in vitro and maintained function when implanted into growing lambs and mechanically expanded over 10 weeks. Results support further long-term testing of the venous valve–inspired prosthetic valves. Congenital heart valve disease has life-threatening consequences that warrant early valve replacement; however, the development of a growth-accommodating prosthetic valve has remained elusive. Thousands of children continue to face multiple high-risk open-heart operations to replace valves that they have outgrown. Here, we demonstrate a biomimetic prosthetic valve that is geometrically adaptable to accommodate somatic growth and structural asymmetries within the heart. Inspired by the human venous valve, whose geometry is optimized to preserve functionality across a wide range of constantly varying volume loads and diameters, our balloon-expandable synthetic bileaflet valve analog exhibits similar adaptability to dimensional and shape changes. Benchtop and acute in vivo experiments validated design functionality, and in vivo survival studies in growing sheep demonstrated that mechanical valve expansion accommodated growth. As illustrated in this work, dynamic size adaptability with preservation of unidirectional flow in prosthetic valves thus offers a paradigm shift in the treatment of heart valve disease.