gms | German Medical Science

Introduction: To develop an artificial reperfusion circuit for reconditioning of damaged donor lungs based on cell containing solutions to expand the donor-pool.

Material and methods: Basic circuit consisted of rotary blood-pump, heparin-coated deoxygenator, reservoir and tubing. Pig lungs were harvested after Perfadex perfusion (40 ml/kgBW), following 90 min. warm ischemia, cannulated, and connected to the circuit. Three groups were analyzed: Group I(n=6) was primed using pig-whole-blood and HES10%, group II(n=8) pig-whole-blood and HES10% including leukocyte-filter, group III(n=7) Steen-solution and isolated porcine erythrocytes plus leukocyte filter. Perfusion started at 21°C to reach 37°C within 30 min. and continued for 6 hrs. Ventilation started at 32°C(FiO2=0.3). Ventilation, gas-exchange and hemodynamics, were monitored hourly during reperfusion. Wet-dry ratios were calculated pre-/post-reperfusion, histology was performed. Transplantability was evaluated hourly by pulmonary-deflation-index (PDI 1-5: degree of collaps and edema during disconnection from the respirator) and standard clinical donor criteria.

Results: At study-end-point only 17% of lungs in group I, 37.5% in group II, but 100% in group III were evaluated transplantable. Group III showed no change throughout 6 hrs. reflected well by lowest post-reperfusion wet-dry ratios after 48 hrs. (group I 9.4, 95% CI (7.0-11.8); group II 7.0 (5.0-9.1); group III 3.4 (1.3-5.6)). Pulmonary compliance was significantly lower in group I as compared to group II and III (p<0.05). Pulmonary oxygenation capacity was continuously low in group I and decreased in group II, while it was stable in group III. PVR was elevated throughout reperfusion in all groups. Histology revealed diffuse interstitial edema with abundant (group I) or occasional sites (group II) of local inflammation, in group III intact parenchyma.

Conclusion: Prolonged maintenance and reconditioning of ischemically predamaged lungs is feasible for 6 hrs if reperfusion is performed with Steen-solution and washed erythrocytes combined with leucocyte filtration. Further extension of reconditioning time might be possible with medical treatment of still increased pulmonary vascular reactivity.