Is it possible to recondition donor-lungs after damage due to brain-death induction?

Objectives: We previously established a reperfusion circuit that allowed safe maintenance of porcine pulmonary lungs for up to 6hours. Aim of our study was to use this set-up to recondition lungs damaged by brain-death induction.

Methods: Brain death was induced by rapid balloon inflation into the cranial cavity (BD, n=6) or not induced (control, n=6). After cold Perfadex perfusion (40ml/kg) heart-lung-block was explanted, cannulated after 90min warm ischemia and placed in a circuit consisting of rotary blood-pump, leucocyte-filter, heparin-coated deoxigenator, reservoir and tubing. Priming consisted of erythrocyte concentrate and Steen-solution (1:1; Hb5,5mg/dl). Perfusion started at 21°C, temperature increased to 37°C within 30min and continued for 6hours. Ventilation started at 32°C (FiO2=0,3). Ventilation parameters, gas exchange and haemodynamics were monitored pre-harvest and hourly during reperfusion, wet-dry ratios measured pre- and postreperfusion, histology performed on H&E stains.

Results: All lungs were perfused for 6hrs. Control lungs showed no significant change throughout the study. After 3 hours of brain death there was significant reduction of pulmonary compliance (35±4,3 vs. 47±2,9ml/cmH2O), increase of PVR (322±73 vs. 193±97dynes), mild hypercapnia (49±7,2 vs. 41± 7,2mmHg), histologically diffuse interstitial edema with massive pulmonary cellular infiltration. During first hour of in-vitro reconditioning functional parameters deteriorated further significantly vs. control (compliance: 22±4,6 vs. 35±7,1ml/cmH2O; PVR 1356±626 vs. 718±176 dynes; p<0,05), however recovered after further 3–4 hours to control values and remained stable until study-end-point. Multi-lobar histology proved completely normalized parenchyma.

Conclusion: Reconditioning of predamaged lungs after brain-dead is feasible. After 3 hours of reperfusion pre-damaged lungs achieved the values of control lungs.