EFFECTS OF LUNG PRESERVATION WITH EURO-COLLINS AND UNIVERSITY-OF-WISCONSIN SOLUTIONS ON ENDOTHELIUM-DEPENDENT RELAXATIONS

Background. This study compares the effect of lung preservation using flush perfusion of Euro-Collins or University of Wisconsin solution on the pulmonary vascular function of endothelium-dependent and endothel ium-independent relaxations. Methods. Rings of canine intrapulmonary a rteries were studied after 6 hours of cold ischemia in Euro-Collins or University of Wisconsin preservation solution. Endothelium-dependent and endothelium-independent relaxations were induced in organ chamber experiments. To also study pulmonary resistance vessels, endothelium-d ependent relaxations were induced in in vitro perfused intact rabbit l ungs. Results. In the organ chamber experiments, a moderate but signif icant (p < 0.05) reduction in endothelium-dependent relaxations were f ound in the perfused and stored vessels. In perfused rabbit lungs, a d ecrease in the endothelial response occurred immediately after perfusi on with Euro-Collins solution. However, a recovery and overshooting re sponse was found after preservation with either solution and 6 hours o f cold ischemia. A significant increase in the sensitivity of smooth m uscle cells to nitric oxide was shown in both preparations. Conclusion s. Both crystalloid perfusion fluids cause a decrease in endothelial f unction during the perfusion procedure. In contrast, endothelial funct ion is well preserved during the ischemic time, University of Wisconsi n solution induced a higher sensitivity of the vascular smooth muscle to the endothelium-derived relaxing factor nitric oxide. A reduction i n pulmonary vascular resistance after University of Wisconsin preserva tion may be of importance in subsequent clinical lung transplantation. (C) 1997 by The Society of Thoracic Surgeons.