About 40,000 children are born each year with a congenital heart defect, according to the American Heart Association (AHA). From the 1960s until now, the options have improved considerably for pediatric patients. According to the AHA, the risk of dying following congenital heart surgery has decreased from 30% (in the 1960s and 1970s) to 5% now. Pioneers in cardiac surgery, such as Alfred Blalock (see below) have helped lead the way. "Certain forms of congenital heart defects that would have been considered lethal 20 years ago are now being repaired routinely. Despite our progress repairing many congenital heart defects, a small percentage of the children with congenital defects will have heart transplantation as their only chance for survival," says Hopkins Pediatric Cardiologist, Dr. Janet Scheel.
Recognizing the link between research and improvements in patient care, Hopkins recently reviewed the last two decades in pediatric heart surgery with Dr. Leonard L. Bailey, the surgeon famous for his October 26, 1984 transplant where he placed the heart of a baboon in the chest of Baby Fae. Although Baby Fae did not live (she did well for a few days, but soon thereafter succumbed to irreversible rejection), Dr. Bailey has continued to research cross-species transplantation as one of the possibilities that may make more children afflicted with congenital heart disease able to "grow up, fall in love, get married and do all of the things that we do as part of life."
Dr. Bailey’s cross-species work represents a small part of current research. In fact, cross-species transplant research has almost come to halt over the past ten years because some scientists believe that there could be a possibility of introducing health problems from other species to humans. This has not been proven, but remains a potential risk. While research in this area continues at a slow pace, other advances have been made in using mechanical assistive devices and refining surgical techniques to improve cardiac operations.
The past ten years of research on the outcomes of pediatric transplant surgery indicates that there is much to be hopeful for among young transplant patients. Dr. Bailey noted that there have been minimal episodes of rejection among pediatric patients both initially and over the long term. No one yet understands why, Dr. Bailey acknowledged, but neonatal transplant recipients have better survival rates than the all other heart transplant recipients.
In addition to measuring surgical success, Dr. Bailey wanted to make sure his young patients were given the chance to experience full, enriching lives. Dr. Bailey’s research team contacted pediatric patients who had been transplanted over the past twenty years and assessed their physical and intellectual growth. Said Dr. Bailey, "I was pleased to see that so many were performing well."
The team measured the height and weight of children who undergone transplantation, and found that the children were all in the standard range. The team also looked at the children’s scholastic records and found that 80% of them were receiving school grades that were equal to their school-aged peers.
In the future, Dr. Bailey predicted that heart specialists may be able to further improve outcomes for patients by identifying how
patients’ immune systems are able to tolerate transplanted hearts. Scientists in Toronto have begun exploring this area by placing hearts into infants from donors with different blood-types. The infants’ immune systems have tolerated these new hearts, but scientists are still are unsure of how this process works. In speaking on the transplant community’s inexperience in immune tolerance, Dr. Bailey acknowledged, "If we knew how to manipulate this inexperience better, we’d be steps ahead."
