Cardiac experts in Children's Hospital's Heart Center currently are involved in two separate projects to develop external and implantable VADs. It is estimated that as many as 1000 children annually may benefit from these technologies, according to Peter D. Wearden, MD, PhD, a paediatric cardiothoracic surgeon and director of Paediatric Mechanical Cardiopulmonary Support at Children's.
"Unfortunately, because this is a relatively small market, companies that make medical devices historically have not focused their attention on paediatric VADs", Dr. Wearden stated. "Because of this, our options for treating young children in heart failure have been extremely limited. Our hope is that these two projects will lead to the first paediatric devices being approved by the FDA for use in the United States."
Children's and medical device manufacturer Levitronix LLC received a $2,3 million National Heart Lung and Blood Institute Small Business Innovation Research (SBIR) grant to complete development of, and to clinically test, the first external centrifugal pump designed specifically for infants and small children in heart failure.
The team currently is finalizing tests of this device in the laboratory and hopes to begin the clinical trial in the coming year. The device, known as the PediVAS - ventricular assist system, would be an external pump designed to support paediatric patients in heart failure for days to four weeks. Dr. Wearden also is spearheading efforts to develop the first totally implantable paediatric VAD in the United States that could be used for longer periods of time than the external pump.
In the development of an implantable paediatric VAD known as PediaFlow, Children's team is partnering with two pioneers in cardiac support, Harvey S. Borovetz, PhD, deputy director, Artificial Organs and Medical Devices, McGowan Institute for Regenerative Medicine, and chair, Department of Bioengineering, University of Pittsburgh; and James Antaki, professor, Department of Biomedical Engineering, Carnegie Mellon University. Industry partners in the consortium include Launch Point Technologies, Santa Barbara, California and WorldHeart Corporation, Salt Lake City, Utah.
This project, also funded by the NIH - one of only five centres in the nation to receive NIH funding for such a project, has progressed through an intensive engineering design phase to successful testing in the laboratory. The consortium is entering the final year of the five-year NIH contract to develop the PediaFlow.
"Our dream for the PediaFlow - which is about the size of a walnut - is that it could be totally implanted into a child to support his or her heart until a donor could be located or until the heart function recovers", Dr. Wearden stated. "The PediaFlow would be magnetically powered and potentially could support a child for as long as six months."
Under the leadership of Victor Morell, MD, chief of Children's Division of Cardiothoracic Surgery, Children's Heart Center has established itself as one of the most active and innovative centres in the care of children in heart failure in the country over the last two decades. Children's has performed more than 300 heart, heart-lung, lung and heart-liver transplants in children, including more than 200 heart transplants. Children's is one of the world's most experienced centres in the use of VADs to support paediatric transplant patients awaiting donor hearts.
Until such time as a paediatric VAD is developed and approved for use, Children's is one of several hospitals in the United States to have asked for and been granted, on a case-by-case basis, approval from the FDA to implant the Berlin Heart Excor for compassionate use. Five patients at Children's have received Berlin Heart Excor devices and gone on to receive successful heart transplants. This VAD, developed in Germany, is an external pump that can be used in small children.
"We've been successful in using the Berlin Heart pump to keep young patients alive and healthy long enough for a donor heart to become available for transplant, and we are able to use adult pumps in our larger paediatric patients", Dr. Morell stated. "But getting approval to use a Berlin Heart can be a complicated process, especially when a young child's survival is dependent on it. This funding from the NIH for these projects is so crucial to our efforts to develop a paediatric VAD for use here in the United States as additional options for the hundreds of kids who suffer heart failure each year."