Machine keeps transplant heart beating
A new procedure allows for more hearts to be transplanted; St Vincent’s Hospital surgeon and researcher, Arjun Iyer, shows off the miracle machine.
Kumud Dhital has a very unusual dream. One day, he hopes to work in a lab surrounded by human organs that are surviving outside the human body.
Even more strange is that his dream is not far away from becoming a reality.
Associate Professor Dhital believes that within two years doctors from the Victor Chang Cardiac Research Institute may be able to drastically increase the number of livers, kidneys and lungs available for transplant using a new technique that brings them back to life after their donor has died.
Associate Professor Kumud Dhital from the Victor Chang Cardiac Research Institute with the purpose-built liver transplant machine. Photo: supplied
He and researchers at the Victor Chang have hand-built special portable rigs that can keep an animal liver alive and fed with blood, oxygen and nutrients outside the body, which may enable them to transplant previously unviable donor livers within the next 18 months to two years. They are also in the process of building a machine that will work on kidneys.
“It’s become very, very exciting,” Associate Professor Dhital said. “The lessons we learn from one organ are helping us move on to another.”
Dr Dhital helped pioneer the use of dead hearts that have been brought back to life after they stopped beating.
Just two years ago, Fairfax Media first reported the team’s experiments with the hearts. Since then, six people have received the life-saving procedure, with all patients doing well and the procedure expanding across Australia and overseas.
Dr Dhital said as a person died, it was a “very vulnerable time” for the organs they might donate.
Like life, every death is different. After life support is withdrawn, a person can die within only a few minutes. In other cases, it may take more than an hour.
As soon as life support is withdrawn, a race against time begins for the transport team. If it is longer than 30 minutes between life-support withdrawal, the person’s circulation stopping, and the team beginning their work, irreparable damage may occur as the organs are deprived of oxygen.
“If we could even take it out to 40 minutes, that would make many more livers available,” he said. “And in fact, why couldn’t we extend the heart viability even longer?”
The most recent data from the Australia and New Zealand Liver Transplant Registry shows that, in 2013, the liver waiting list increased again, to 164. Each year about 10 per cent of the people on the list will die waiting.
Professor Henry Pleass, a multi-organ transplant surgeon at the Westmead and Royal Prince Alfred hospitals, said liver transplants after circulatory death, as opposed to brain death, had come back into use in Australia only about five years ago, because of a shortage of donors.
Doctors prefer to use livers donated after brain death because there is some evidence they lead to healthier recipients.
But Professor Pleass said only a small minority of livers donated after circulatory death were able to be used.
“We want to be able to utilise more livers,” he said. “The past couple of years, there have been about 100 donors in NSW and not all of them by any means are suitable liver donors.”
Of those 100, about 30 donate after circulatory death. Yet only about five livers were actually transplanted after circulatory death last year in NSW.
Dr Dhital believes he is setting up the only lab in the world that will be able to manage multiple organs through the same laboratory. On Wednesday, he will have pig hearts, kidneys and livers all being kept alive at once on the rudimentary machines the team have built so far.
His “dream” is to have one machine with “organ-specific disposable modules” that can be used to support whatever organ is needed, and to be able to fully assess the function of those organs and even treat them before they are put into the body.
However, he said the programs were running “off literally money donated by relatives of patients and charitable trusts” and Australia would not stay ahead of the pack without sustainable funding.
The team will present their work at the 2015 Victor Chang Transplantation Symposium this week, including at a free public talk between 3pm and 5pm on Thursday, at the Garvan Auditorium in Darlinghurst.