Cadaver lungs for transplantation - Effect of ventilation with alveolar gas

In an effort to increase the donor pool for lung transplantation (LTX), we have demonstrated the feasibility of LTX from circulation-arrested cadavers in a canine LTX model. We hypothesized that ventilation of the cadaver lung with alveolar gas (20% O-2, 5% CO2, balance N-2) (AG) would be superior to ventilation with 100% oxygen (O-2) after circulatory arrest of the donor. Twelve mongrel dogs were intubated, heparinized and euthanized by pentothal injection and ventilated with AG (n=6) or O-2 (n=6). Four hours later, donor animals underwent sternotomy, and the lungs were flushed with cold modified Euro-Collins solution, harvested, and stored inflated in iced slush. Left lung allotransplantation was performed, and recipients were made dependent on the transplanted lung by occlusion of the contralateral bronchus and pulmonary artery. Recipient animals were ventilated with an FiO(2) of 0.4 and followed for 8 hr. Total ischemic time was 7.9 hr for both groups. Pulmonary edema developed in all recipients of AG lungs; one recipient survived the 8-hr observation period with poor oxygenation. In contrast, three of six recipients of O-2-ventilated lungs survived for 8 hr with excellent gas exchange. Specimens of donor lungs before and after transplant were evaluated histologically utilizing trypan blue exclusion as an indicator of cell viability. At the time of organ retrieval 4 hr after death, 6% of cells were nonviable in the O-2-ventilated cadaver lungs, compared with 11% in AG-ventilated cadaver lungs. Circulation-arrested cadaver lungs ventilated with 100% O-2 prior to organ retrieval have superior pulmonary function after transplant compared with lungs ventilated with AG. Ventilation of cadaver lungs with AG induces pulmonary injury in this model. Retrieval of donor lungs from circulation-arrested cadavers has potential for increasing the pulmonary donor pool.