Boston Children’s Hospital is touting a new design that could allow children to maintain the same prosthetic heart valve until adulthood, which could also benefit adults with heart valve defects.
Current prosthetic heart valves implanted in children with congenital heart disease are fixed in size, which requires multiple open-heart surgeries during childhood to replace the valve with a larger version. The valve being designed at Boston Children’s Hospital has shown in studies, simulations and animal testing that the design works throughout a range of sizes and retains functionality when expanded by a minimally invasive balloon catheter procedure, according to a news release.
Today, senior author Boston Children’s Hospital chairman of cardiovascular surgery Dr. Pedro del Nido and colleagues had their research published in Science Translational Medicine.
“We hope to bring this new device into clinical testing fairly rapidly,” del Nido said in the news release. “If our preclinical results hold up in human testing, this could transform the field.”
According to the news release, current available prosthetic heart valves consist of three leaflet-like flaps providing a one-way inlet or outlet for blood to flow. The new design by Boston Children’s Hospital has just two leaflets, with a geometry designed to maintain closure and one-way flow even when veins expand in diameter.
Through benchtop testing and large animal models, the valves were adjudged to be able to expand to accommodate growth and structural asymmetries within the heart while maintaining their functional through multiple dimensions, pressures and flow rates.
Researchers said the valve’s ability to expand without the frame and leaflet stretching or enlarging makes it compatible with off-the-shelf materials. Studies showed that the device could expand at different points of time in a growing animal model with a minimally invasive catheter balloon approach, according to the hospital.
Another potential benefit of the new design is the possibility of favorable blood flow through the valve, reducing the risk of blood clot formation that may accompany valve replacement devices. When implanted in a growing sheep, the researchers saw no evidence of blood clot formation over a 10-week period in which no blood-thinning medication was used.
“A shortcoming of many existing devices is the presence of flow disruptions that lead to blood clot formation and early valve deterioration,” said Dr. Sophie Hofferberth, a Boston Children’s researcher and surgical resident at Brigham & Women’s Hospital. “Our design achieves a favorable flow profile that seems to facilitate effective valve washout and minimize flow stagnation, which is likely to be an important determinant of long-term device durability.”
According to the news release, the research team at Boston Children’s Hospital believes the data they’ve accumulated supports the initiation of a clinical study within the next one to two years.