CANINE DOUBLE-LUNG TRANSPLANTATION WITH CADAVERIC DONORS

If lung could be retrieved from cadavers after circulatory arrest , th e critical shortage of donors for lung transplantation might be allevi ated, To assess gas exchange after transplantation of lungs from cadav eric donors, we performed double-lung transplantation through sequenti al thoracotomies in 12 dogs, Donors were sacrificed by intravenous pen tobarbital injection and then ventilated with 100% oxygen, Lungs were harvested 2 hours (n = 6) or 4 hours (n = 6) after death and flushed w ith 2 L modified Euro-Collins solution, Recipients underwent sequentia l right and left lung transplantation; they were then monitored while under anesthesia for 8 hours, with adjustments of the fraction of insp ired oxygen, Nine of 12 recipients survived the 8-hour study period, F our of six dogs with cadaveric lungs retrieved 2 hours after death sur vived; deaths were from pulmonary embolism at 6 hours and pulmonary ed ema at 2 hours, Five of six dogs with cadaveric lungs retrieved 4 hour s after death survived; one died of hypoxia during implantation of the left lung, while dependent on the right lung graft, Postoperative hem odynamic and gas exchange parameters were similar in both groups, Alve olar-arterial oxygen gradient rose significantly compared with baselin e 1 hour after transplantation in both groups (462 +/- 60 vs 38 +/- 31 mm Hg for 2-hour group, p < 0.0001, and 484 +/- 63 vs 38 +/- 14 mm Hg for 4-hour group, p < 0.0002), By 8 hours after operation, the gradie nts had significantly decreased in both groups (105 +/- 37 mm Hg for 2 -hour group and 146 +/- 53 mm Hg for 4-hour group) and were similar to baseline values, Extravascular lung water also rose significantly 1 h our after transplantation (15.7 +/- 2.8 vs 7.9 +/- 0.5 mVkg for 2-hour group, p < 0.02, and 16.9 +/- 1.2 vs 6.6 +/- 0.4 ml/kg for 4-hour gro up, p < 0.0001) and decreased gradually during the 8-hour study period . Donor lungs retrieved at 2 and 3 hours postmortem afford similar rec ipient outcomes, Improvement in alveolar-arterial oxygen gradient and reduction in extravascular lung water during the study period imply th at the ischemia-reperfusion injury induced by this model is reversible , If this approach could be safely introduced to clinical practice, su bstantially more transplant procedures could be performed.