Ex vivo lung perfusion

A technique for assessing and improving donor lungs prior to transplantation

Ex vivo lung perfusion (EVLP) is a medical procedure used to evaluate and improve the function of donor lungs outside the body before they are transplanted into a recipient. This technique allows for the assessment of lung function and the potential for therapeutic interventions to enhance lung quality.

Overview

EVLP is a process where donor lungs are maintained in a normothermic, or body temperature, environment while being perfused with a specialized solution. This allows for the evaluation of lung function, including gas exchange, and provides an opportunity to treat the lungs to improve their condition before transplantation.

Gas exchange in the alveolus

Procedure

The EVLP procedure involves several key steps:

Lung Harvesting

Donor lungs are carefully harvested from a deceased donor. The lungs are then transported to the transplant center where they undergo EVLP.

Perfusion and Ventilation

The lungs are connected to a perfusion circuit that circulates a solution through the pulmonary vasculature. This solution is typically a modified Steen solution, which is designed to mimic blood and provide necessary nutrients and oxygen to the lung tissue.

The lungs are also ventilated with a mechanical ventilator to simulate breathing. This allows for the assessment of lung compliance and gas exchange capabilities.

Assessment

During EVLP, various parameters are monitored, including:

• Oxygenation capacity
• Carbon dioxide elimination
• Pulmonary vascular resistance
• Lung compliance

These parameters help determine the suitability of the lungs for transplantation.

Therapeutic Interventions

If the lungs show signs of dysfunction, therapeutic interventions can be applied. These may include:

• Administration of antibiotics to treat infection
• Anti-inflammatory agents to reduce inflammation
• Surfactant therapy to improve alveolar function

Atelectasis

Benefits

EVLP offers several advantages in the field of lung transplantation:

• Increased Donor Pool: By improving marginal lungs, EVLP increases the number of lungs available for transplantation.
• Improved Outcomes: Transplanting lungs that have been assessed and optimized through EVLP can lead to better post-transplant outcomes.
• Extended Preservation Time: EVLP allows for extended preservation of donor lungs, providing more time for matching and preparation.

Challenges

Despite its benefits, EVLP also presents challenges:

• Complexity: The procedure requires specialized equipment and expertise.
• Cost: The process can be expensive, which may limit its availability.

Pulmonary edema

Future Directions

Research is ongoing to improve EVLP techniques and expand its applications. Innovations in perfusion solutions, ventilation strategies, and therapeutic interventions continue to enhance the effectiveness of EVLP.

Related pages

• Lung transplantation
• Organ transplantation
• Pulmonary rehabilitation

Bronchoscopy