2026-01-23T15:01:00
(BPT) – A newborn’s heart will grow roughly 15 times larger in volume by the time adulthood is reached — a remarkable transformation that presents an extraordinary challenge for pediatric heart surgeons treating congenital defects such as aortic and pulmonary valve disease.
Heart defects affect approximately 1% of babies born in the United States each year, or roughly 40,000 infants. For many families, these diagnoses mark the beginning of long and arduous journeys. Children born with complex valve defects often require repeated surgeries and other treatments as their hearts grow, exposing them to risks and potential complications and their families to overwhelming emotional and financial strain.
Finding a better way to treat these young patients has been a longtime goal for Minoo N. Kavarana, M.D., chief of Pediatric Cardiothoracic Surgery at the Medical University of South Carolina and co-director of the Pediatric and Congenital Heart Center at the MUSC Shawn Jenkins Children’s Hospital.
“I kept thinking about babies born with the most common congenital heart defect — bicuspid aortic valve,” Kavarana said. “When infants need valve surgery in the first week of life, they often face multiple open-heart procedures and catheter-based balloon dilations over their lifetimes.”
While advances in postoperative care have significantly improved outcomes for pediatric heart surgery, risks still remain. And each additional operation compounds that risk.
“Every time we reopen a child’s chest, we expose them to more trauma,” Kavarana said. “That’s when I started asking: ‘Could we implant a valve early in life that could be expanded over time with a balloon and continue functioning into adulthood after a single operation?'”
That idea — a pediatric valve stent capable of growing with a child — had the potential to change pediatric heart care, and it aligned with the culture of innovation that has earned national recognition for MUSC’s program.
The Pediatric Cardiology & Heart Surgery program at the MUSC Shawn Jenkins Children’s Hospital is ranked No. 4 in the nation for 2025–2026 by U.S. News & World Report, marking its fourth consecutive year in the top four and its ninth straight year in the top 12. The program is recognized for outcomes, cutting-edge technology and advanced clinical expertise, placing it among the nation’s elite programs.
A constructive reunion
As Kavarana searched for a solution, he got a call from a bioengineering team at Clemson University with whom he had previously collaborated. The team, led by Clemson bioengineering alumnus Lee Sierad, Ph.D., and his mentor Dan Simionescu, Ph.D., the Harriet and Jerry Dempsey Professor of Bioengineering, was developing a novel valve concept to treat congenital heart defects in infants. They had confidence in their design but needed clinical insight into how hearts grow, how valve disease evolves over time and how surgeons confront these challenges in the operating room. That led them to reconnect with MUSC and Kavarana.
Kavarana helped the team to tie innovation to clinical reality, clarifying which defects mattered most and how growth patterns should inform device design.
“We were asking fundamental questions,” Sierad recalled. “Would this look like a metal stent that expands? Should we design it for a one-month-old, a one-year-old or a 10-year-old?”
Simionescu said that Kavarana’s input led them to shift the design team’s direction. “Historically, we take adult devices and make them smaller,” he said. “That approach doesn’t work for children. Pediatric patients need something that grows with them.”
From concept to prototype
With vital funding from the National Institutes of Health (NIH) and the Emerson Rose Heart Foundation, which was created in honor of the infant daughter of Susan and Jason Smith who passed away due to a congenital heart defect, the MUSC-Clemson collaboration led to the creation of ExpandValve, designed to evolve in tandem with a growing heart. The device is a thin metal scaffold capable of expanding from an infant-sized diameter of 10 to 12 millimeters to an adult-sized diameter of 24 millimeters (just less than an inch) through gradual, controlled balloon dilations.
But allowing the valve to grow was only part of the puzzle. The team also had to account for changing blood pressures, flow dynamics and tissue response across every stage of childhood.
“All of the clinical data we shared helped the engineers to recreate conditions that closely mirror the human heart,” Kavarana said. “They’re able to test these valves in a bioreactor that simulates real physiologic environments.”
What comes next
If all goes well in the simulations, the next step on the road would be proof-of-concept testing in living hearts, which must yield positive results before potential clinical trials could begin.
“This step is essential,” Kavarana said. “If successful, this technology could dramatically reduce the cumulative trauma children experience from repeated heart surgeries and change what lifelong care looks like for families.”
For Kavarana and the Clemson team, the goal is clear: to replace a lifetime of repeated interventions with a future defined by fewer surgeries, fewer risks and far more hope.
Learn more about the Pediatric and Congenital Heart Center at the Medical University of South Carolina at Children.MUSCHealth.org/medical-services/heart.
