British Girl Thriving Three Years After Donor Heart Was Removed Following "Piggyback" Transplant

July 14, 2009

July 14, 2009 (London, United Kingdom) — A 16-year old British girl, Hannah Clark, is living a full and active life three and a half years after the removal of a donor heart that was transplanted heterotopically, or in "piggyback" fashion, on top of her own failing heart when she was a toddler [1].

Hannah's case is the first of its kind reported in the literature and as such provides many important lessons, say Dr Victor Tsang (Great Ormond Street Hospital, London, UK) and colleagues in their paper, published online July 14, 2009 in the Lancet.

Second author Sir Magdi Yacoub (Imperial College London, UK), who performed the original heterotopic transplant on Hannah, told heartwire : "This demonstrates that a small heart can be used to support the left ventricle in a child who is bigger, so therefore it is maximizing the use of donor organs, which we know are scarce. Hannah also had severe pulmonary hypertension, and by using the donor heart in this way, we avoided a heart/lung transplant. In her case, the pulmonary artery pressure has reverted completely back to normal." Also, using this method of transplant reduced the time she was waiting for a donor heart, which has been shown to affect long-term outcomes, he explained, adding, "She was not going to survive." And there were many lessons learned regarding therapy for the cancer she later developed, he noted.

Dr Peter Weissberg (British Heart Foundation) says this work opens the way for new research into just how damaged hearts manage to recover, "which in turn may lead to new treatments for heart failure." Also, it proves that, in some instances, a weakened heart has the capacity to recover if it can be helped. "This breakthrough provides a great boost to ongoing efforts to perfect ventricular assist devices," he says in a statement [2].

At a London press conference yesterday, Hannah, now aged 16, burst into tears when asked by a journalist how the surgery had changed her life: "Thanks to this operation, I’ve now got a normal life just like all of my friends."

A Long and Winding Road

Hannah was first admitted to the hospital aged 8 months, in 1994, with severe heart failure secondary to dilated cardiomyopathy. She continued to deteriorate and was wait-listed for cardiac transplantation, the only effective form of treatment for severe forms of this disease, Yacoub explained. But transplants are not easy in children of this age, because of the severe scarcity of pediatric donors, difficulties in matching the size of organ, and the serious long-term complications of nonspecific immunosuppression, he noted.

They decided on a heterotopic transplantation, attracted by the idea that the surgery might enable functional recovery of Hannah's own heart by allowing prolonged offloading of her left ventricle. Yacoub performed the heterotopic transplant in July 1995, when Hannah was two, using a donor heart from a child aged five months. The donor heart was responsible for most of the cardiac output in the first three months after transplantation, and it showed progressive improvement in function during the next three years.

Amazingly, the native heart also started to recover. Four and a half years after the transplant, in December 2000, both the donor and native hearts were functioning normally, with ejection fractions of 80% and 70%, respectively.

But then Hannah developed posttransplant lymphoproliferative disorder (PTLD) associated with Epstein Barr virus (EBV), a major malignant complication of organ transplants, with an incidence of 4% to 6% after heart transplant. Despite aggressive chemotherapy and a reduction in the dose of immunosuppressants, the PTLD appeared incurable.

qWe wanted to get rid of the cancer, and the donor heart had become a liability, so it all made sense.

Yacoub said the decision to remove the donor heart "took some time," but they were eventually persuaded by the fact that it had "suffered massive rejection" due to the tapering of her immunosuppressive therapy during cancer treatment. "It had stopped beating and was full of clots. We wanted to get rid of the cancer, and the donor heart had become a liability, so it all made sense." The only technical problem, he said, was that the doctors at Great Ormond Street Hospital "didn't know where to put the anastomoses, so I helped in that sense."

Hannah and her family, he said, "were very supportive. They never argued. They are very determined and intelligent, and they wanted to know why, how, and when things were going to happen; they wanted the best for Hannah."

The operation to remove the donor heart, which took place in February 2006, just over a decade after the original transplant, was "not simple" he said, "because the [donor] heart was completely surrounded by fibrous tissue, and there was no obvious plane of cleavage."

However, there were no complications afterward, and Hannah left the hospital just days after the donor heart was removed. Three and a half years later, she doesn't require any immunosuppression, she remains in complete remission from PTLD, and she has normal cardiac function, "with a high normal LVEF of 80%," says Yacoub.

"Hannah has her own heart, which is not showing any signs of deterioration--in fact it's getting better and better with time," he says.

Is This an Option for Other Children With Dilated Cardiomyopathies?

Yacoub believes heterotopic transplantation is an option for infants such as Hannah with severe dilated cardiomyopathy, many of whom would otherwise die waiting for a transplant. "I think this has a place, although many people don't like it because it's a complex procedure." He thinks a randomized trial should be performed, to try to demonstrate what he views as the benefits.

There are currently few other options, such as LVADs, for children of this age, although this should change within a couple of years. One such device does exist, manufactured by Berlin Heart, but it's not ideal, says Yacoub.

He added that other heterotopic cardiac transplants have been performed--for example, a group in Holland recently showed that a donor heart was still working well in a patient after 22 years.

However, one of the possible complications is that the recipient heart doesn't recover, he explained: "You can get aortic regurgitation, clots, and arrhythmias, particularly if the heart is ischemic.

"I have actually gone in and replaced the recipient's heart with a new donor heart, so the patient has two donated hearts," he noted. Other surgeons choose to move the donated heterotopic heart to the orthotopic position if the recipient's heart fails, he says, "but my view is, if you have a good functioning heart, why move it?"

The authors declare that they have no conflicts of interest.

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