Researchers from the Center for Engineering in Medicine at the Massachusetts General Hospital developed a new ‘super-cool’ method for temporary organ storage.
The research team cooled down a human liver to temperatures below the freezing point during experiments that radically increased its longevity.
Members from the Harvard Medical School also collaborated with the team from Massachusetts General Hospital (MGH) for the research.
Sub-zero temperatures for organ preservation
The team cautiously cooled the donor, making sure it didn’t freeze, while it was being transported from the donor to the donee. The temperatures were kept well below zero while avoiding freezing.
This tripled the wait time that a liver can survive before being transplanted into the donee body. In addition, the donor’s liver stays safe and viable during the process.
The findings from the study, published in Nature Biotechnology, could save millions of lives while greatly expanding the availability of healthy livers. Further, this could improve organ utilization and reduce the time pressure on procurers.
Currently, only 5% of liver patients requiring transplant can actually get one. The research addresses the shortfall in the organ-market.
Dr. Reiner J. de Vries, Shannon N. Tessier, and Korkut Uygun from the Massachusetts General Hospital (MGH) and Harvard Medical School were the most prominent members of the research team.
Current transplantation techniques and life expectancy
The current life expectancy of a healthy liver once sourced from the donor is about 9 hours. This short life span is further reduced when the storage is done on ice which damages the tissues irreparably.
The current storage temperatures range between 39.2 to 46.4 degrees F. However, no amount of care can keep it alive for more than 9 hours. After which time the tissues start degenerating and the organ has to be discarded.
Theoretically, colder temperatures could always be used for storage. But the freezing that comes with it could render it useless.
Prior to this research, MGH researchers ‘supercooled’ rat livers to 21.2 °F while keeping injury at bay. This decrease to around -6o C without causing injury to the tissues extended the preservation time from a few hours to more than a day.
As the liver is cooled the volume increases, therefore it becomes all the more difficult to stop ice from forming.
During the research, the team developed a solution which was delivered to the liver through machine perfusion. Perfusion ensures that the preservative solution is evenly distributed throughout the organ before further steps can be performed.
Firstly, the liver is cooled to subzero temperature right after the perfusion. Once under the zero point, the human livers are cleared for transport. Secondly, at the transplantation site, machine perfusion is again utilized to warm the livers and prepare them for transplantation.
This technique has enabled the liver to survive for more than 24 hours outside the body. This time frame is long enough for the liver to be shipped cross-country or even between countries.
This super-cool technique can save millions of lives each year by increasing organ utilization rates.
The geographical gaps in organ availability
There are several problems faced by the organ transplant industry. Many a time there are donors but no recipients in the region. In places, there are patients in need of a transplant but no donors are in the safe transplant geographical region.
This opens up new avenues as it would enable better organ matches and fewer rejection rates. Recipients did not bother looking for potential donors in areas which were far away as it was not medically possible to make sure a liver survives that long.
Further clinical trials of the technique are being supervised by the team who have already deemed their super-cool technique to be super-safe.