In an unprecedented feat, British surgeons implanted a donor heart in a dying toddler whose own heart was too weak to sustain life, then removed it 10 years later after the girl's own heart had fully recovered.
The technique is unlikely to become widespread because of the severe shortage of pediatric donor hearts, but it suggests that better mechanical assist devices that take some or all of the load off a diseased heart could allow time for weakened hearts to heal themselves.
The procedure, reported online Monday in the medical journal Lancet, shows that "the heart has reparative capabilities that we suspected it might have, but for which we have really lacked a great deal of proof," said Dr. Douglas P. Zipes of Indiana University, a former president of the American College of Cardiology. "We need to understand better how it does it, capitalize on that and be able to use it in routine therapy."
There have been cases in which a second heart was implanted, then failed "and the patients were able to go on for a while with the native heart," said Dr. Matthias Loebe, director of thoracic transplantation and assist devices at the Baylor College of Medicine, one of the leading U.S. centers for heart surgery in children. "But there has never been anything similar to this reported in the literature. That's impressive."
As the journal article recounts: In July 1995, Hannah Clark was 2 years old and suffering from dilated cardiomyopathy, in which the heart becomes weakened and enlarged and cannot pump blood efficiently. The problem is most often caused in young children by genetics or viruses, and affects 1.2 to 1.4 children per 100,000. The prognosis is normally very poor.
Noted heart surgeon Dr. Magdi Yacoub of Imperial College London and Harefield Hospital grafted a donor heart, obtained from a 5-month-old infant, in parallel to Hannah's own heart -- allowing it to take over the bulk of pumping duty, a procedure known as a heterotopic heart transplant. The procedure required substantial doses of immunosuppressive drugs to prevent the heart from being rejected.
The heart functioned efficiently and Hannah was soon able to lead a normal life, but the drugs began to produce their own problems -- allowing the development of a virus-related cancer called Epstein-Barr-virus-associated post-transplant lymphoproliferative disorder. The cancer was suppressed with courses of powerful drugs, but it kept recurring, and surgeons reduced the dose of anti-rejection drugs to help Hannah's body fight it.
