Medical research: Identifying additional livers that may be suitable for transplantation

An evaluation of donor liver function may allow for the identification of livers suitable for transplantation that would be discarded based on current clinical practise, according to a study in Nature Communications. These findings may lead to larger pools of donor livers becoming available for transplantation.

A shortage of suitable donor livers limits patient access to liver transplantation. However, some donor livers are considered unsuitable for transplantation based on a subjective clinical assessment and are discarded. Identifying donor livers from the pool of discarded organs that could be safely transplanted is a major clinical challenge.

Hynek Mergental, Darius Mirza, Simon Afford and colleagues evaluated whether measuring the clearance of the metabolite lactate as a marker of liver function during normothermic machine perfusion (a method for organ preservation) could help identify suitable donor organs from the pool of discarded donor livers. Using this method, they identified 22 of 31 evaluated livers as suitable for transplantation, and successfully transplanted them into patients (aged 46 to 65) in a clinical trial. None of the patients in the trial experienced early graft failure by 90 days after transplantation, but seven patients developed early graft dysfunction. During further follow up at a later stage, four patients developed a serious complication, called non-anastomotic biliary strictures, which required another liver transplant. The trial did not include a randomized control group, but a comparison group that received livers meeting the current clinical guidelines and matched for some aspects of the trial presented fewer cases of early graft dysfunction and non-anastomotic biliary strictures.

The authors conclude that the functional assessment of liver function during preservation may identify suitable donor livers from the pool of currently discarded organs. However, studies to identify sensitive biomarkers for long-term graft survival will be needed.