Innovative Technique Allows Safe Preservation of Donor Lungs for Up to 20 Hours

A recent study has revealed a groundbreaking method for the preservation of donor lungs outside the body prior to transplantation, demonstrating that the hypothermic oxygenated machine perfusion (HOPE) technique is both safe and effective, even when total out-of-body durations reach nearly 20 hours.

The findings were shared at the Annual Meeting and Scientific Sessions of the International Society for Heart and Lung Transplantation (ISHLT) held in Boston. The study was led by organ perfusionists and transplant coordinators from UMC Utrecht in the Netherlands, who highlighted the significance of this advancement in lung preservation.

The HOPE technique has previously been utilized for preserving donor livers and kidneys and is currently under investigation for its effectiveness in heart preservation. However, its application for lung preservation has not been extensively explored until now.

Ex vivo lung perfusion (EVLP) is a critical technique that enables the maintenance, assessment, and potential reconditioning of donor lungs outside the body before they are transplanted. This process involves connecting the lungs to a pump and ventilator, allowing them to be perfused with a solution that acts as a physiological fluid.

The researchers at UMC Utrecht have developed a HOPE protocol designed to safely extend the times that donor lungs can be perfused, ensuring their viability overnight until transplantation can occur the following day.

Typically, donor lungs are transported on ice and warmed to 37 degrees Celsius for functional assessment using a normothermic EVLP (nEVLP) protocol. Following this assessment, the lungs are returned to an ice environment until the transplantation procedure begins. However, the HOPE protocol streamlines this process by eliminating the secondary cooling phase, allowing for one hour of assessment during nEVLP, followed by preservation at a temperature of 12 degrees Celsius until the transplant.

Data presented from 12 cases utilizing the nEVLP-HOPE protocol were compared with historical data from 118 cases of lungs transplanted directly without the benefit of ex vivo lung perfusion. The control cohort consisted of cases from 2017 to 2022, while the HOPE protocol was applied in cases from 2022 to 2024 for logistical optimization.

Notably, none of the lungs preserved using the nEVLP-HOPE method were rejected for transplantation, and the short-term outcomes were comparable to those observed in the control group. This indicates that the HOPE protocol is a viable option for lung preservation following a period of normothermic EVLP.

As a next step, researchers aim to identify the most advantageous preservation strategies tailored to specific types of donor lungs. Extending the duration that donor lungs can be preserved outside the body opens up possibilities for optimizing these organs through various therapies, potentially enhancing transplantation outcomes in the future.