Miniaturized heart pumps may be effective for children awaiting transplant
October 23, 2008 -- Two weeks after an American Heart Association study outlined the success of miniaturized heart assist pumps, the Berlin heart – a pediatric ventricular assist device – received unconditional FDA approval for clinical trails.
In the study, led by Dr.Sanjiv Gandhi, Cardiothoracic Surgeon at St. Louis Children’s Hospital and Washington University School of Medicine, nine pediatric patients with severe heart failure were successfully kept alive for an average of 35 days with miniaturized heart assist pumps while awaiting a heart transplant. The study is published in the Cardiovascular Surgery Supplement of Circulation: Journal of the American Heart Association.
“It is not unusual for a child at the top of the transplant candidate list to wait several months before an organ becomes available,” said Dr. Gandhi.
Researchers implanted biventricular assist devices, known as BiVADs, in seven girls and two boys ranging in age from 12 days to 17 years. All had severe heart failure due to cardiomyopathy or complex congenital heart defects and weighed less than 88 pounds. One child died from kidney failure before receiving a heart transplant. After 19 months of follow up, the other eight were alive with new hearts.
Children who need heart transplants and are very ill can be placed on external circulatory support machines, but their long-term use is associated with significant risks. Patients also must be immobilized, which impairs physical rehabilitation efforts.
The ventricular assist devices allow for physical rehabilitation that improves the patient’s overall condition and likelihood of successful transplantation, according to Dr. Gandhi. In this study, complications such as postoperative bleeding and blood clots blocking a blood vessel occurred infrequently, but there was a high incidence of blood clotting in the pumps.
Small heart pump devices have been available in Europe for many years, but they are not approved for use in North America. However, the miniaturized Berlin Heart EXCOR® ventricular assist recently received conditional approval for clinical trail in North America.
The data emphasize the importance of continued development and refinement of mechanical ventricular assist devices in the pediatric population.