A study on donor lungs preserved outside the body before transplantation demonstrated that the hypothermic oxygenated machine perfusion (HOPE) technique is a safe and effective lung preservation method, even with total out-of-body times approaching 20 hours.

Jitte Jennekens, MSc, organ perfusionist/transplant coordinator at the UMC Utrecht in the Netherlands, presented the study results at today's Annual Meeting and Scientific Sessions of the International Society of Heart and Lung Transplantation (ISHLT) in Boston.

"This technique is being used to preserve donor livers and kidneys and is being studied in clinical trials for hearts, but it hasn't gotten that much attention for lung preservation yet," said Jennekens.

Ex vivo lung perfusion (EVLP) is a technique that allows for donor lungs to be maintained, assessed, and potentially reconditioned outside of the body before transplantation. The lungs are connected to a pump and a ventilator and perfused with a solution that functions as a physiological fluid.

The UMC Utrecht developed its HOPE protocol to safely extend perfusion times, to maintain the viability of the lungs overnight until the transplantation can be performed during the day.

Donor lungs selected for EVLP are typically transported on ice and then warmed to 37 degrees Celsius using a normothermic EVLP (called nEVLP) protocol for functional assessment. Following nEVLP, the lungs are then returned to ice until the transplant begins.

The HOPE protocol eliminates the second period on ice by assessing the lungs during one hour of nEVLP and then preserving the lungs at 12 degrees C until the procedure.

Jennekens presented data comparing the outcomes of 12 cases conducted using the nEVLP-HOPE protocol with a historical cohort of donor lungs transplanted directly into patients without ex vivo lung perfusion.

The control cohort included 118 cases of lungs transplanted directly without perfusion between 2017 and 2022. The cases were performed between 2022 and 2024 using the HOPE protocol for logistical reasons.

No lungs in the nEVLP-HOPE group were rejected for transplantation, and short-term outcomes were similar between the study and control groups.

"Our findings indicate that HOPE is a safe and effective lung preservation method after a period of normothermic EVLP," Jennekens said.

Jennekens said the next step is to determine the preservation strategy that will be most beneficial to a specific type of donor lung.

"Extending perfusion times for donor lungs outside of the body will allow for a future in which donor lungs can be optimised with different therapies," she said.