Miniaturization of the organ care system ® into rat lungs for the establishment of ex-vivo therapy

Objectives Organ Care System ® (OCS) is a well-established system used in human lung transplantation, allowing warm perfusion and ventilation of donor lungs. Besides lung retrieval, OCS therefore offers an innovative opportunity for clinical ex-vivo therapy of diseased lungs for different indications, e. g. tumor therapy. While the patient is on extracorporeal membrane oxygenation, the otherwise inoperable lungs can be treated in OCS, followed by autotransplantation. For the development of this ex-vivo therapy, a miniaturized OCS was established. Methods Wistar rats were euthanized (per group n=5), left lungs were connected to OCS, while right lungs were stored on ice. OCS lungs were ventilated and perfused at body temperature under continuous monitoring (e. g. pressure). Four different perfusion solutions were analyzed (Steen solution ® ± blood, OCS solution ® ± blood). Finally lungs were processed histopathologically. Results OCS worked technically faultless, perfusion and ventilation went well. All perfusion solutions showed stable pH, pO2, pCO2, oncotic pressure and systemic pressure. Using perfusion solutions combined with blood, lactate levels increased up to 7,0mmol/l and base excess has to be stabilized by sodium hydrogen carbonate. Pathological work up revealed no significant morphological changes, except for focal atelectasis. There were no delimitable differences between the examined groups. Conclusions The miniaturized OCS is a reliably working system to establish the ex-vivo therapies for different indiations. As ex-vivo therapies may need to be applied for more than 4 hours, extended perfusion times and various perfusion solutions are currently investigated.