Advancements in Machine Perfusion Extend Travel Range for Donor Hearts

In Australia, where vast distances separate metropolitan areas, the challenge of transporting donor hearts in a timely manner has historically resulted in many organs going unused. For instance, if a potential recipient is found in Sydney while the heart is located in Perth, a significant distance of nearly 2,000 miles must be covered, typically requiring a five-hour flight. When accounting for the time needed for retrieval and preparation, this could lead to a total journey of approximately seven hours.

At the Annual Meeting and Scientific Sessions of the International Society of Heart and Lung Transplantation (ISHLT) held in Boston, a cardiothoracic surgeon from St. Vincent's Hospital in Sydney emphasized the importance of optimizing organ transportation times to enhance the utilization of donor hearts. The introduction of machine perfusion technology has been a game-changer in this regard, allowing for the preservation of donor hearts during transport.

Previously, donor hearts were kept in portable coolers, which gave transplant teams a limited window of six hours to perform surgeries. However, machine perfusion utilizes a device that circulates a blood-like solution through the heart while it is being transported, significantly extending this time frame. St. Vincent's Hospital has been a pioneer in this technology since 2014, initially applying it to hearts donated after circulatory death (DCD). Currently, over half of the heart transplants at the center employ this innovative technique.

St. Vincent's has successfully extended normothermic machine perfusion (NMP) protocols, where donor hearts are preserved at approximately 35 degrees Celsius, for durations of up to eight hours. Some other hospitals in Australia have even managed to utilize this technology for ten hours. This advancement marks a significant shift in the ability to accept donor organs from regions that were previously deemed too far away.

Looking ahead, the possibility of international exchange of donor hearts may become a reality. Currently, Australia retrieves donor organs from New Zealand, but machine perfusion opens avenues for potential transplants from the Pacific Islands and Asia. There exists a considerable number of patients on transplant waiting lists who face challenges in finding suitable matches within their local genetic population. Accessing a broader geographic pool for potential donors may offer viable solutions for these patients.

Research conducted at St. Vincent's indicates that the outcomes for transplants involving machine perfusion are comparable to those performed using traditional methods. Key metrics, such as primary graft function in the transplanted heart, have shown no significant differences, suggesting that this technology effectively mitigates the impact of time during transportation.

The introduction of machine perfusion represents a transformative advancement for heart transplant teams. As surgical practices evolve, the limitations previously imposed by organ transportation are gradually being overcome, paving the way for innovative approaches to organ donation and transplantation.