Cardiac Devices – Jarvik: For Smaller Hearts
CCHD’s next series introduces the various Cardiac Devices involved in the treatment of Congenital Heart Disease and the associated conditions. In the first post, Dr. Adachi tells us about the Jarvik for small hearts, a ventricular assist device used to help pump blood through the body.
At our institution, we are working to create a smaller, implantable ventricular assist device
(VAD), specifically designed for small children. This device is called the Infant Jarvik VAD, named
for Dr. Robert Jarvik, the inventor of the first successful total artificial heart.
Why do we need this device?
In the world of pediatrics, most VADs are pulsatile, which means they pump like the heart.
However, these sometimes fail. This is why most adult VADs are now continuous flow pumps,
meaning they help push blood through the body using an impeller. Currently, there are no
pediatric continuous flow devices available for our smallest patients. We are hoping to change
that with a small, AA-battery- sized device.
It is more challenging to make a smaller pump with a favorable performance. After failing to get
FDA approval two years ago, Jarvik made significant design changes, and I came on board to test
the redesigned device in animals as a preclinical trial. The data we collected was much more
favorable than the previous testing, resulting in approval for a clinical trial by the FDA. The
Pumps for Kids, Infants and Neonates (PumpKIN) trial has just begun with seven major pediatric
heart centers in North America, including Texas Children’s Hospital, ranked #1 nationally in
pediatric cardiology and heart surgery by U.S. News & World Report.
Currently, hospitals across the country have limited options on the types of patients they can
support. For example, at Texas Children’s, we implant about 20 to 30 VADs each year. In many
of these cases, we have to use an adult device in a child, which inevitable causes patient-device
size mismatch. If the Jarvik infant pump becomes available, that may change device support
paradigms, leading to more potential candidates who can benefit from this implant at hospitals
nationwide.
Dr. Adachi has written extensively regarding surgical, morphological, and physiological aspects of congenitally malformed hearts. His clinical and research interests also include pediatric heart failure and mechanical circulatory support including ventricular assist device and total artificial heart. He is also studying cardiac cellular and sub cellular differentiation prior to and following application of mechanical assistance. He also has an interest in pediatric lung transplantation. For better preservation of donor lungs, he seeks to develop a pediatric-specific lung preservation device for deployment in the lung transplant program at Texas Children’s, which is the largest in the world.