Real-time lung weight measurement during clinical ex vivo lung perfusion

Background

Real-time lung weight (LW) measurement is a simple and noninvasive technique for detecting extravascular lung water during ex vivo lung perfusion (EVLP). We investigated the feasibility of real-time LW measurement in clinical EVLP as a predictor of transplant suitability and post-transplant outcomes.

Methods

In our clinical acellular EVLP protocol, real-time LW was measured in 117 EVLP cases from June 2019 to June 2022. The estimated LW gain at each time point was calculated using a scale placed under the organ chamber. The lungs were classified into 4 categories based on LW adjusted for height and compared between suitable and unsuitable cases. The relationship between estimated LW gain and primary graft dysfunction was also investigated.

Results

The estimated LW gain during the EVLP significantly correlated with the LW gain (post-EVLP LW and pre-EVLP LW) measured on the back table (R² = 0.61, p < 0.01). In the adjusted LW categories 2 to 4, the estimated LW gain at 0-1 hour after EVLP was significantly higher in unsuitable cases than in suitable cases. The area under the curve for the estimated LW gain was ≥0.80. Primary graft dysfunction grades 0 to 1 had a significantly lower estimated LW gain at 60 minutes than grades 2 to 3 (−43 vs 1 g, p < 0.01).

Conclusions

Real-time lung measurements can predict transplant suitability and post-transplant outcomes by the early detection of extravascular lung water during the initial 1 hour of EVLP.