In a recent study, 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, according to a report 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 Sanjiv K. Gandhi, M.D., lead author of the study, cardiothoracic surgeon, and Surgical Director of the Heart Failure program at Saint Louis Children's Hospital in Missouri.

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 40 kilograms (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, researchers said. 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 EXCORR ventricular assist device recently became available in North America on a compassionate use basis, meaning patients can be approved for the pumps if they have no other treatment options.

The data emphasize the importance of continued development and refinement of mechanical ventricular assist devices in the pediatric population, researchers said.