CONTROLLED REPERFUSION AND PENTOXIFYLLINE MODULATE REPERFUSION INJURYAFTER SINGLE-LUNG TRANSPLANTATION

Objective: Rodent models have suggested that initial low-pressure repe rfusion of transplanted lungs reduces injury after ischemia, We invest igated this phenomenon and the use of pentoxifylline in a porcine mode l of left single lung transplantation, Methods: Donor lungs were prese rved with Euro-Collins solution for a mean ischemic time of 18.4 hours . Neutrophil trapping in the graft, pulmonary artery pressure, and gas exchange were assessed over a 12-hour period, Partial occlusion of th e contralateral pulmonary artery allowed manipulation of the pulmonary artery pressure in the transplanted lung. Group A (n = 5) was perfuse d at a mean pulmonary artery pressure of 20 mm Hg, group B was reperfu sed at a mean pulmonary artery pressure of 45 mm Hg for 10 minutes bef ore reducing the pressure to the same as group A, and group C was repe rfused at a mean pressure of 20 mm Hg for 10 minutes, then increased t o a mean of 45 mm Hg for the remainder of the experiment. Group D was reperfused as in group A with the addition of intravenous pentoxifylli ne. Results: Leukocyte sequestration was observed in the first 10 minu tes after reperfusion in groups A,B, and C, with maximal sequestration at 2 minutes. Significantly more sequestration was observed in the fi rst 6 minutes in group B than in groups A and C, which were similar. P entoxifylline significantly reduced leukocyte sequestration. Pulmonary venous oxygen tension in the allograft lung was worst in group B, Gro ups A and C were similar, but group D was superior to all other groups (p < 0.001), Conclusions: Low-pressure reperfusion, even when limited to the first 10 minutes, modulates reperfusion injury possibly throug h a leukocyte-dependent mechanism. The addition of pentoxifylline in t he recipient confers significant additional benefit.