Extravascular Lung Water Quantification in Donor Lungs

Abstract

Purpose Extravascular lung water (EVLW) could change in donor lungs in a time-dependent fashion during procurement or Ex-Vivo Lung Perfusion (EVLP) and may vary across different zones. Current techniques for EVLW assessment are either subjective or not feasible in the clinical setting. An accurate and non-invasive diagnostic tool for monitoring EVLW would be desirable for donor lung assessment and management. Therefore, we studied the accuracy and reliability of direCt Lung Ultrasound Evaluation (CLUE) technique for the quantification of EVLW. Methods Eleven clinically rejected donor lungs underwent cellular EVLP for 2 hours. In CLUE, ultrasound images were taken directly from the lung surface. A scoring system was created for each point based on the percentage of B-lines. Images were graded according to the degree of edema. The following equation was used to calculate total lung and lobe scores using the number of images of each grade. CLUE total Score = (No. of Grade 1 images x 1 + No. of Grade 2 images x 2 + No. of Grade 3 images x 3 + No. of Grade 4 images x 4 + No. of Consolidation images x 5) / Total No. of images taken The images were reviewed by four blinded raters. CLUE scores and lung weight were measured before and after EVLP. Wet/dry (W/D) ratio was measured from tissue samples taken after EVLP. Results CLUE point score correlated with W/D ratio measured from tissue samples taken from the same location (n = 99, r = 0.86, p (P/F) ratio measured at a sample taken from the corresponding pulmonary vein (n = 20, r = -0.78, p Conclusion CLUE technique showed a substantial inter-rater reliability. CLUE scores were significantly correlated with lung weight, W/D, and P/F ratio. These findings demonstrate the reliability and accuracy of CLUE in quantifying EVLW, which can be applied to donor lung clinical assessment and management.