An expandable artificial heart valve could save children with congenital heart disease from repeated open heart surgeries as they grow up, researchers report.
Current artificial heart valves are fixed in size, meaning children need to get larger ones as they grow. Children who receive their first artificial valve before age two will require up to five open-heart operations before they become adults.
This new design means children could keep the same artificial heart valve until adulthood, and it could also benefit adults with heart valve defects, according to the Boston Children's Hospital team.
Current artificial heart valves have three leaflets, tiny flaps that provide a one-way inlet or outlet for blood to keep it flowing in the right direction. This new valve has two leaflets and as a patient grows it can be expanded through a minimally invasive balloon catheter procedure.
Lab tests, computer simulations and extensive testing in animals show that the new artificial valve works across a wide range of sizes, and remains functional when expanded, according to a study published online in the journal Science Translational Medicine.
"We hope to bring this new device into clinical testing fairly rapidly," said senior author Dr Pedro del Nido, chair of cardiovascular surgery at Boston Children's.
"If our preclinical results hold up in human testing, this could transform the field," del Nido added in a hospital news release.
Research in animals doesn't always pan out in humans. But a human clinical trial could begin within one or two years, according to the researchers.
Rheumatic heart disease
The investigators said their design encourages good blood flow through the valve, which may reduce the risk of blood clot formation that often occurs with existing artificial valves.
In tests with sheep, there was no evidence of blood clot formation over 10 weeks of observation, even without the use of blood-thinning medications typically given to patients with artificial heart valves.
Each year, more than 330 000 children worldwide are born with a heart valve defect, and millions of others develop rheumatic heart disease requiring valve replacement.
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