Neurohumoral modulation of the pulmonary vasoconstrictor response in the autoperfused working heart-lung preparation during cardiopulmonary preservation

Granulocyte sequestration and early failure in the autoperfused heart-lung preparation

We investigated the role of pulmonary granulocyte sequestration in the development of early failure of the autoperfused working heart-lung preparation. A significant decline in the total circulating leukocyte count in 21 preparations at 60 minutes of perfusion (5.0 to 1.4 x 10(3)/microL; 28% of baseline; p less than 0.001) was observed. Differential cell counts in 14 of these preparations revealed a predominant decrease in granulocyte count (8.7% of baseline) and a moderate decline in lymphocyte count (46% of baseline). In study I, indium 111-labeled autologous granulocytes were injected intravenously into 10 adult New Zealand White rabbits. In group I (n = 5), an autoperfused working heart-lung preparation was harvested and perfused for 60 minutes. In group II (controls, n = 5), the heart-lung block was harvested following 60 minutes of in situ perfusion. Organ blocks were imaged before and after saline flush. There was a significant decline in granulocyte counts at 60 minutes of perfusion in group I versus no change in group II (I, 2.3 +/- 0.4 to 0.3 +/- 0.1; p less than 0.01; II, 1.7 +/- 0.2 to 2.3 +/- 0.5; not significant; x 10(3)/microL +/- standard error of the mean). Postflush lung activity was significantly increased in group I versus group II (I, 3,751 +/- 566; II, 1,867 +/- 532; p less than 0.05; counts +/- standard error of the mean). In study II, 15 autoperfused preparations were divided into two groups. Group I (n = 10) preparations were controls. Group II (n = 5) animals were depleted of leukocytes by pretreating with nitrogen mustard. Group I (controls) produced a bimodal survival distribution (Ia, 8.2 +/- 1.0; Ib, 26.4 +/- 2.0; hours +/- standard error of the mean). Group II survival was significantly longer than that of group Ia and similar to that of group Ib (II, 25.3 +/- 2.2; p less than 0.01 versus group Ia, not significant versus group Ib; hours +/- standard error of the mean). Hemodynamic profiles for group II closely paralleled those of group Ib. In conclusion, pulmonary sequestration of granulocytes occurs early in the autoperfused working heart-lung preparation (within 60 minutes of autoperfusion), and preoperative leukocyte depletion prolongs survival of the autoperfused working heart-lung preparation by eliminating the subset group Ia (short survivors) seen in untreated preparations.