Heart Pumps Bring Hope to Young Patients
Monday, March 14th 2005, 10:09 am
News On 6
PITTSBURGH (AP) _ An experimental, child-size artificial heart pump may be saving the lives of children awaiting heart transplants, doctors say.
Shanah Bridgett's heart failed when she was only 8. Carlos Ochoa was 7 when his heart began to stiffen, limiting its pumping ability. Miles Coulson was just weeks old when doctors discovered he had an enlarged heart.
For years, pumps have been used successfully for adults awaiting transplants. But only recently have U.S. researchers focused attention on devices for the tiniest heart patients. Because so few children need such technology _ maybe 30 or 40 a year in the United States _ there has been no commercial interest in producing such pumps here.
At Children's Hospital of Pittsburgh, surgeons have been working with a European ventricular assist device called the Berlin Heart. They have implanted the device, approved for use in Europe, in Shanah and another child.
``It's the difference between a dead child and a live child,'' said Dr. Steven Webber, medical director of the hospital's heart transplantation program.
Shanah was near death when she got her implant; eight days later, she received a donor heart. Now her mother often has to scold her for doing one-handed cartwheels.
``She's doing phenomenal,'' said Lori Bridgett, of Pittsburgh.
The pediatric Berlin Heart has only been used in the United States 12 times, in each case with emergency government approval. The German company that makes the device, Berlin Heart AG, plans to seek approval from the U.S. Food and Drug Administration, said chief executive Rene Garo.
Some children develop heart disease from a virus or other illness; others _ more than 30,000 a year in the United States _ are born with heart defects, according to the National Institutes of Health. Surgery helps in many cases, but for some the only solution is a transplant, which means waiting with a dangerously weak heart until there's a donor.
In 2003, the most recent year complete statistics are available, 181 heart transplants were performed in the United States on children 10 and younger, according to the United Network for Organ Sharing.
Webber said about 25 percent of children waiting for new hearts die before receiving a transplant, and the Berlin Heart could reduce that number. He and Dr. Victor O. Morell, chief of cardiothoracic surgery at Children's Hospital of Pittsburgh, said even a wait of a few days for the FDA's emergency approval for the pump can cost lives.
The device, also known as EXCOR, sits outside of the body and is connected to the heart and vessels by a pair of tubes. It takes some of the workload off the ventricles by taking blood from the atria and pumping it to the lungs and then the body.
It's basically a child-size version of adult pumps. But there's been little incentive for U.S. companies to invest in manufacturing these or going through the lengthy and expensive FDA approval process, said Dr. Mark W. Turrentine, co-director of Pediatric Cardiac and Pulmonary Transplantation at the Indiana University School of Medicine.
``They really couldn't justify that cost because it's such a low-volume market. They'd never recoup the cost,'' he said. Berlin Heart pumps have been used three times on children at the Riley Hospital for Children in Indianapolis, where Turrentine is a surgeon.
Complications can include blood clotting inside the pump, infection and pump failure. Adult pumps can sometimes be used with teenagers or larger children, but are too large for infants or the very young. And some children, already sick, can be much smaller than other children their same age, necessitating a much smaller pump.
The Berlin Heart for children was first used in Europe in 1990 and has been used overseas more than 100 times, Garo said. It was first used in the United States in 2000; it kept Carlos Ochoa, of Nogales, Ariz., alive for just over a month, until he received a donor heart.
Children implanted with the Berlin Heart tend to become stronger and healthier, putting them in a better condition to survive transplantation.
``I think there's enough success with it and enough of a safety profile established,'' Turrentine said. ``There's nothing to compete with it. It fills a void for children.''
Last year, the FDA approved a different type of pediatric pump, the DeBakey ventricular assist device. It was developed by Dr. Michael DeBakey, the renowned cardiovascular surgeon and pioneer in the development of the artificial heart.
The pump is implantable and sits within the body, unlike the EXCOR. But it can only be used in teenagers and older children, doctors said.
Children awaiting transplants can be placed on a machine known as ECMO, or extracorporeal membrane oxygenation, to help their hearts pump, but they can only be on the device for a few weeks.
Dr. Carl Backer, professor of surgery at Northwestern University Medical School and a surgeon at Chicago's Children's Memorial Hospital, said the ECMO machine is the better choice in some cases. Backer, who has never implanted a Berlin Heart, said for a patient whose lungs aren't functioning well, ECMO is able to replenish oxygen in the blood, something the Berlin can't do.
He said his hospital does about 10 pediatric heart transplants a year, and only 10 percent to 20 percent may be candidates for the Berlin Heart.
But Backer added: ``Most of us surgeons feel like if it was something we had sitting on our shelf, we would use it more often.''
Last year, the National Institutes of Health's National Heart, Lung and Blood Institute awarded millions of dollars to several programs across the country in an effort to speed up the development of pediatric pumps. In Pittsburgh, Webber, Morell and others are working on a completely implantable pump that is about the size of a chestnut.
But any new devices are years away from use.
``In the meantime, we need this Berlin heart,'' Webber said.