Widespread support for mechanical hearts

The development of a mechanical alternative to a heart transplant for a child that could be construed as durable for a lifetime was a “formidable” challenge which would prove to be extremely expensive for hospitals.

However, there was cause for optimism, due to prospective trials which could advance the support of children – and those involved in treating children with heart disease must take on the challenges “respectfully and courageously”.

These were the words of Charles Fraser, Surgeon in Chief at Texas Children’s Hospital during the Christiaan Barnard Hospital Lecture.

In an address entitled A Mechanical Alternative to Transplantation, Fraser said hundreds of thousands of patients needed transplants every year.

With only 2000 heart transplants being conducted in the US a year, there was an extremely low likelihood of a child receiving a donor heart.

For this reason, the world needed a “transformational advance” to build on the transformational event of the first heart transplant conducted in Cape Town by Dr Chris Barnard.

“In terms of actual community benefit we are not meeting the need.”

“We have been making incremental progress which has been really good but to broadly apply a new therapy … to those that need, we need something that is transformative …to more people,” Fraser said.

The challenge was formidable because “in childhood particularly, we have a number of problems. Children grow, they are very active and their response to medicine is different. The potential application is measured, not in terms of months or years, but in decades so we have to have a mechanical device which is either easily interchangeable or one that is durable for a lifetime – and neither of these propositions exist right now.”

“A transformative event in mechanical support for a child would be a device that would be capable of sustaining that person either in its original implanted form for a lifetime or one that can be easily changed out.

“So that seems to me to be a very significant challenge in mechanical support in children.”

Fraser said there was widespread hope that the upcoming trials for the small Jarvik device would result in an incremental advance in support of children.

“But the clinical experience is very limited … and I hope we don’t repeat mistakes.”

There were some clever devices being worked on at institutions including the Indiana University and at the Texas Heart Institute as well as in Australia.

But, asked whether he was optimistic that he would see a mechanical device for children in his lifetime, Fraser said:

“It is intuitively difficult for me to imagine that a mechanical solution is going to be the end point for children. I think it is more plausible that it will be a biologic solution of some sort.

“The line of thinking that Professor Doris Taylor of the Texas Heart Institute and her colleagues are pursuing is exciting. It might be the wrong one to bet on. I don’t know.

-That line of thinking is very exciting … my money is on that. A biologic substitute is more logical to me.”

 

The ‘smoking gun’

 

Although there is no hard evidence of a link between stroke and HIV and AIDS, there is a “smoking gun” to suggest that this could be the case, says Dr Alan Bryer of the division of neurology at Groote Schuur Hospital.

Bryer is part of a team at the hospital whose research into possible links began in 2006 the “pre-ARV era” and is still continuing today.
In South Africa 11 percent of the total population of 54-million people are infected with HIV and it is the leading cause of deaths in the country.
International research into possible links began in the 80s and 90s, with subsequent retrospective research, but the question of a possible has still not bee suitably answered, says Bryer.
“We do not know if it (stroke) is a cause or a coincidence, but there is a smoking gun and there is the possibility that there is a relationship.”

WCPCCS 2013 and the gift of life

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Gift Ihuhua (14), his father Matthews Ihuhua are from Windhoek. With them is the cardiologist Dr Harold Pribut

Four hundred heart specialists from around the world watched history being made in Cape Town as a 14-year-old Namibian boy underwent the implantation of an artificial valve via a vein without any need to cut open his chest.

The innovative procedure was one of many which were watched during the intervention sessions of the congress.

Delegates were able to watch procedures which were taking place at hospitals in South Africa and Europe which were transmitted live into an auditorium.

The operation, which was hailed as a big success, was performed by South African Dr Harold Pribut and Belgian Dr Marc Gewillig.

John Lawrenson, one of the scientific organisers of the conference explained that the boy was born with pulmonary atresia, a condition where his heart was not connected to his pulmonary arteries.

“When he was born, he was extremely blue, as there was no blood going to the lungs to pick up oxygen.

“He had surgery as a younger child, using a homograph. However this had become narrowed over time and started leaking. “Because the scar tissue that forms inside can sometimes defeat even the best surgeons in terms of redo operations, this homograph was replaced by a percutaneous valve.

“So a stent has been compressed, but inside this scaffolding was sewn a valve which came from a cow’s jugular vein,” Lawrenson said.

Explaining further, he said: “Cows have big veins. Inside the vein are valves. The vein has been stitched inside the stent, fitted onto a balloon and delivered into the hart. The balloon was opened up and the valve stent was placed. So the stent is now open, filling the narrowing and inside the stent is this valve that is now working.

“They have got over the narrowing and have a valve that is not leaking at all.”

Lawrenson said the procedure had been done around the world for about ten years. The valve, known as the Melody Valve had become available worldwide.

“The problem is it is very expensive.”

Lawrenson said the Cape Town operation had gone “absolutely fine”.

The interventional cases had been a “remarkable” experience for delegates. This was the first time this had been done from a conference in South Africa in terms of live paediatric cases.

“They are watching holes being closed inside the heart, they have watched narrowings in the aorta being fixed, they are watching the replacement of the aortic valve in an adult and they are going to watch the creation of a hole between chambers to allow better mixing of blood.

“We have watched interventions from Milan, Frankfurt, Cape Town and Johannesburg,” he said.

Thursday will see more local interventions when operations are transmitted from both the Red Cross Hospital and Panorama