New Promise for Infant Heart Transplants

Aug. 7, 2002 -- The numbers are heartbreaking: Every 90 minutes, one person in the United States dies while waiting for a lifesaving organ transplant.

Among those on the transplant list are 2,200 children under 18, newborns and infants with heart disorders.

They are often the extremely sick and have the smallest window of opportunity for survival, experts explain. And because of their small size, doctors often face difficulty in finding suitable hearts for them.

"There are just a lot less actual donors available, and the numbers of infants being transplanted as a primary procedure for congenital heart disease, instead of trying other surgical procedures first, has increased," says Dr. Linda J. Addonizio, medical director of the Pediatric Cardiac Transplant Program at Columbia-Presbyterian Medical Center in New York City.

Scientific Advancements

Yet medical experts have been greatly encouraged by significant advances in infant heart transplants in recent years.

For instance, to increase the number of young children who will receive a heart, doctors are now focusing on transplanting infants using donor hearts once deemed incompatible.

"Currently, our center and a handful of others are trying to transplant certain very young patients [under 8 months] across blood groups," says Dr. Edward L. Bove, director of pediatric cardiac surgery at the University of Michigan Medical School in Ann Arbor.

"Previously, it was thought that you could only receive your own blood type," he adds. "While this is still not possible in older children and adults, there has been good short-term success in infants."

The rate at which children are put on the transplant list after being diagnosed with life-threatening conditions is also encouraging.

"We have been fortunate that recently children are starting to be referred for transplant before they are dying in the ICU [intensive care unit], which gives us more time to treat their heart failure and find a donor," says Addonizio.

In addition, new devices that help the heart function are being developed which will buy time until donor hearts become available.

"We now have 'left ventricular assist devices,' that work pretty well as a bridge to transplant for the older kids," says Addonizio. The artificial pumps keep the heart beating until a human heart is located for transplant into the patient.

But while efficient adult devices are readily available, like the HeartMate and the Novacor, there are none yet suited for small children or infants. Several groups are working on these devices, says Bove. "The near future also will bring more effective immunosuppressive techniques with fewer side effects."

Size Matters

While the future of heart transplantation is encouraging, there are still many challenges that remain.

Because the process of matching transplant hearts is based only roughly on body weight and heart size, adult hearts can often be used for children and vice versa. But there are certain criteria that must be met.

"We can place a heart from a donor who is two times larger by body weight into most children with heart failure, which gives us the leeway we need many times to find a donor for the children," says Addonizio.

Another challenge are those who legally become adults before they receive a transplant. Certain factors, such as their condition, may make them slip farther down the transplant list, giving preference to older adults.

"Many children listed for transplant have congenital heart disease. When they are over 18 the criteria used to govern their priority on the list can often not be applied to these patients with congenital heart disease," explains Dr. Juan Alejos, medical director of the Pediatric Heart Transplant and Cardiomyopathy program at Mattel Children's Hospital of University of California-Los Angeles.

And depending on their blood type and body size, these younger patients may face some stiff competition from older individuals.

"It is most difficult to get "adult-sized" donors for the larger adolescents and children who are big because they compete with the enormous number of adults on the list," says Addonizio.

Experts agree that the donor system presently in place works well for children. In fact, it has made significant improvements over past systems. But there's always room for improvement.

Dr. Tom Graham, director of pediatric cardiology at Vanderbilt University Medical Center in Nashville, Tenn., says hospital workers play an integral part in the process.

"There is an increased need for diligence for ICU and emergency room personnel to get donor services involved early when tragedy strikes a potential donor."

More Donors Needed

Donor availability for pediatric heart transplantation remains the major obstacle.

"Increased public awareness would help to improve the number of donors, with relation to donor availability, knowledge of who can be a donor, and how the process works," says Dr. Joanne P. Starr, pediatric cardiac surgeon, University of Chicago Medical Center.

Addonizio agrees, and hopes that media attention will drive home the message that there is a continual shortage of organs, and will also educate people on the importance of organ donation for themselves and their loved ones.

"It is only through the kindness and generosity of spirit that the donor families possess during the most difficult times of their lives that gives us the opportunity to save these children. It is their heroic gesture at the center of it all," she says.

Bove explains that the way families are approached and by whom can make a big difference in donation rates.

"An improvement in the number of donors could be achieved by each hospital making a commitment to teaching health care providers how to approach families about donation or having specific individuals trained to do so," he says.

Alejos empathizes with families faced with the decision of whether or not to donate a relative's organs, and asks; "I know that the loss of a loved one is a difficult time but please think of the positive you can bring to a dreadful situation by being an organ donor.

ABC's new four-part documentary series, ICU: Arkansas Children's Hospital, will air its first installment tonight at 10 p.m., 9 p.m. Central, focusing on the issues surrounding pediatric heart transplantation.