For years, the pump technology available to help babies and small children with heart failure has lagged behind what's available for adults. But a multi-site clinical trial launching next month aims to close the gap.
The PumpKIN Trial, which will take place at Lucile Packard Children's Hospital Stanford and 21 other North American sites, will test a new ventricular assist device for kids that is only about as big as a AA battery, yet has many of the advantages of VADs used in adults.
Adults and older children who need heart transplants can receive VAD pumps implanted in their chests that allow them to go home and return to most aspects of their lives while they wait to be matched to a donor organ. But until now, the pumps used for small children have been so unwieldy that they required patients to remain in the hospital. The kids' pumps also have higher risks of infection and stroke.
The new VAD being tested -- called the Jarvik 2015 and designed by Jarvik Heart, Inc. -- is intended to bring the portability and safety of adult devices to small children. Recently, I spoke about the research with Stanford pediatric cardiologist Christopher Almond, MD, who is one of the upcoming trial's principal investigators. During our Q&A, he explained why developing the new VAD was more complicated than simply shrinking the grown-ups' devices:
The main challenge of miniaturizing any pump technology is to design it in a way that does not crush fragile red blood cells as they pass through the device, which is spinning several thousand times per minute. An earlier version of the Jarvik 2015 pump tended to break red blood cells and had to be redesigned. Interestingly, a relatively minor design change caused a big reduction in the pump’s red cell breakage.
A second challenge is that the flow rate through miniature pumps is much slower than for adult pumps, greatly increasing the chance that clots can form inside the pump. When clots form, they can break off and travel through the bloodstream to the brain, causing a stroke... However, the Jarvik 2015 pump has a relatively low risk of clot formation.
Previously: Gage Bingham is third in his family to receive a heart transplant, 22-year-old marks five-year anniversary with a heart pump and Doctors at Packard Children's extend life of 20-month-old's failing heart
Photo of Jarvik 2015 pump courtesy of Jarvik Heart, Inc.
