Real-time Lung Weight Measurement During Cellular Ex Vivo Lung Perfusion: An Early Predictor of Transplant Suitability

Abstract

Background. Increased extravascular lung water during ex vivo lung perfusion (EVLP) is associated with ischemia reperfusion injury and poor pulmonary function. A non-invasive technique for evaluating extravascular lung water during EVLP is desired to assess the transplant suitability of lungs. We investigated real-time lung weight measurements as a reliable method for assessing pulmonary functions in cellular EVLP using a porcine lung model. Methods. Fifteen pigs were randomly divided into 3 groups: control (no warm ischemia) or donation after circulatory death groups with 60 or 90 min of warm ischemia (n = 5, each). Real-time lung weight gain was measured by load cells positioned at the bottom of the organ chamber. Results. Real-time lung weight gain at 2 h was significantly correlated with lung weight gain as measured on a back table (R = 0.979, P < 0.01). Lung weight gain in non-suitable cases (n = 6) was significantly higher than in suitable cases (n = 9) at 40 min (51.6 ± 46.0 versus −8.8 ± 25.7 g; P < 0.01, cutoff = +12 g, area under the curve = 0.907). Lung weight gain at 40 min was significantly correlated with PaO 2 /FiO 2 , peak inspiratory pressure, shunt ratio, wet/dry ratio, and transplant suitability at 2 h (P < 0.05, each). In non-suitable cases, lung weight gain at 66% and 100% of cardiac output was significantly higher than at 33% (P < 0.05). Conclusions. Real-time lung weight measurement could potentially be an early predictor of pulmonary function in cellular EVLP.

Lung Donor Selection and Management: An Updated Review

“…Abnormal lung weight gain at 40 minutes can serve as an early warning sign, and lung weight data can help guide therapeutic interventions, such as hemoconcentration. The study also highlights the potential of real-time lung weight measurements in identifying procedural problems during EVLP [109].…”

“…They found that the normalized lung weight gain was greater in the evaluation phase than in the reconditioning phase, and it was highest during evaluation when the FiO2 was 1.0. This implies that increased tidal volume (TV) during recruitment can lead to increased fluid leakage [109].…”

Technical Advances Targeting Multiday Preservation of Isolated Ex Vivo Lung Perfusion

“…Recently, more sophisticated tools, such as real-time donor lung weight measurements, single transpulmonary thermodilution, perfusate biochemistry, and imaging modalities, have been utilized to assist these processes. [38][39][40][41][42][43] The decision to transplant after an EVLP assessment of questionable lungs is not straightforward. The protocols recommend the use of a combination of EVLP physiology and the abovementioned assessment tools when deciding the fate of donor lungs.…”