AsianScientist (Oct. 29, 2014) – University of New South Wales (UNSW) Conjoint Associate Professor Kumud Dhital, who is based at the Victor Chang Cardiac Research Institute, has performed two successful heart transplants using organs that had stopped beating prior to donation, been re-animated inside a novel carrier box and then transported some distance to the waiting recipients.
The recipients, both of whom had end-stage heart failure, are recovering extremely well and took part in a media conference about the world-first achievement today at St. Vincent’s Hospital.
Until now, transplant units have relied solely on donor hearts from brain-dead patients whose hearts are still beating. The use of “donated after circulatory death” (DCD) hearts, where the heart is no longer beating, represents a paradigm shift in organ donation and will make far more hearts available for transplant.
The two DCD transplants, undertaken at St. Vincent’s Hospital Heart Lung Transplant Unit, were possible thanks to pioneering research undertaken by the Victor Chang Cardiac Research Institute and St. Vincent’s Hospital. The two organisations have jointly developed a special preservation solution and portable console in which donor hearts can be housed, resuscitated and transported.
The ex vivo Organ Care System (OCS – TransmedicsTM) involves connecting the donor heart to a sterile circuit where it is kept beating and warm. This limits the detrimental effects of cold ischaemia (a period where the heart is without oxygen or nutrients) that occurs with the standard organ preservation mode of packing the heart on ice. Once inside the portable device, the heart is reanimated and preserved, and can be functionally assessed until it is ready to be placed inside the recipient.
The OCS technology—affectionately referred to as the “heart in a box”—also means organs can be transported over longer distances. It has this year allowed the St. Vincent’s Transplant Unit to conduct several standard heart transplants (ie. using non-DCD organs), using organs that had travelled substantial distances and, most importantly, using “marginal hearts”—non-DCD hearts that would previously have been regarded as unsuitable for transplantation.
There are far more people in need of transplants than there are donor organs. DCD transplants have already made an enormous positive impact on liver, kidney and lung transplantation rates, but until now, it was not possible to do the same with hearts. The heart in a box technology is a game changer.
“This breakthrough represents a major inroad to reducing the shortage of donor organs,” says UNSW Professor Peter MacDonald, Medical Director of the St Vincent’s Heart Transplant Unit and Head of the Transplantation Research Laboratory at Victor Chang. This year marks the 30th anniversary of the St Vincent’s Heart Lung Transplant Unit and the 20th anniversary of the Victor Chang Institute.
“In all our years, our biggest hindrance has been the limited availability of donor organs,” he says.
“It is interesting to note that DCD hearts were utilized for the first wave of human heart transplants in the 1960s, with the donor and recipient in adjacent operating theaters. This co-location of donor and recipient is extremely rare in the current era, leading us to rely solely on brain dead donors—until now,” says Prof. Dhital.
Source: University of New South Wales; Photo: Andy G/Flickr/CC.
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