Perfusion Machine: Prevent problems after liver transplants

Perfusion machine prevents bile duct problems after liver transplants. This is evident from a large international study led by liver surgeon Robert Porte of the UMCG.

Cold, oxygenated perfusion of a donor liver with the perfusion machine before liver transplantation significantly reduces post-transplant bile duct problems.

These complications cause health damage to the patients and lead to a patient having to undergo a new transplant. The perfusion machine thus ensures more efficient use of the scarce number of available donor livers.

This has emerged from a large international study led by liver surgeon Robert Porte of the UMCG. The first study provides direct evidence for the positive effect of cold, oxygenated machine perfusion of donor’s livers. The outcomes of the new research have been declared in the authoritative New England Journal of Medicine.

156 patients followed after liver transplants

No fewer than 156 patients who underwent a liver transplant were followed for this study. All received an organ from a donor who had died of cardiac arrest. Half of the donor’s livers were flushed with an oxygen-rich fluid via machine perfusion for two hours before the extracorporeal transplant operation. The other half of the donor organs were kept cold on ice.

This study looked at the number of times post-transplant biliary problems occurred in the patients. A liver will inevitably be outside the body for some time during a transplant. The bile ducts in the liver are susceptible to the damage caused to the liver. The small blood vessels that run to the bile ducts become damaged. If that happens, there is a higher risk of bile duct complications after the transplant.

Consequences of bile duct complications

These complications occur in about a quarter of all liver transplant patients. About three to four months after surgery, they develop fever, jaundice and inflammation of the bile ducts due to the scarring of the bile ducts damaged by oxygen deficiency. It often leads to additional treatments and interventions for them. It can also happen that a new liver transplant has to take place as a result of the complaints. Bile duct problems are, therefore, the leading cause of the loss of donor’s livers. Livers donated after cardiac arrest are more likely than livers donated after brain death.

Fewer complications after machine perfusion

The study shows that the number of bile duct problems was much less common in the group of patients who received a liver flushed through a perfusion machine. In this group, there were bile duct problems in 6% of the patients compared to 18% of the other group patients.

Research leader Robert Porte is very enthusiastic about this result: “Treatment of the donor liver with oxygen-rich fluid in the perfusion machine protects livers from the damage and inflammatory response that results when the blood supply to the liver is restored after the liver has been temporarily deprived of oxygen. We assumed that this would also protect against the development of bile duct problems after the transplant. We have indeed demonstrated this in this study. This makes it the first study worldwide to prove the effectiveness of this form of machine perfusion. “

More donor livers accepted

Because the risk of complications in livers donated after cardiac arrest is more significant than in livers donated after brain death, this also prevents some transplant centres from accepting such donor livers.

Certainly in the US, you see much less of this type of liver transplants than in countries like the Netherlands, Belgium and the UK. Thus, this machine perfusion technique will not only prevent complications after transplants, but hopefully, it will also lead to more livers from donors who have died after cardiac arrest being accepted for transplant, stated Porte.

Perfusion chamber in UMCG

The UMCG has had a so-called “Organ Preservation & Resuscitation” unit since 2015. In this space, donor organs, such as livers, lungs and kidneys, are treated with oxygen-rich fluid and nutrients for transplantation into perfusion machines. With the new perfusion techniques, organs can be better preserved and improved and tested just before transplantation. This means that more organs can be made suitable for transplantation. The UMCG had previously successfully transplanted rejected lungs that had been optimized in a perfusion machine.