Transitory Blocking of Pulmonary Artery and Veins as a Novel Strategy in Pulmonary Surgery: An Experimental Study in a Rabbit Model

Abstract

Backgrounds: Transitory blocking of the pulmonary artery and veins is now being applied in the treatment of local advanced non-small cell lung cancer in our department. We performed this study to establish a pulmonary vessel blocking model in rabbits and investigate the features of lung ischemia-reperfusion injury. Methods: 126New Zealand rabbits were randomized into 3 groups: group I, sham group; group II, left pulmonary artery blocking, and group III, left pulmonary artery and veins blocking. The physiological data as well as the blood and tissue samples were harvested at the time of thoracotomy, at 1 h after ischemia and 1, 2, 4, 6 and 24 h after reperfusion, respectively. Lung injury was assessed histologically by determining the levels of malondialdehyde, superoxide dismutase, myeloperoxidase and water content. Results: The hemodynamics were stable in all three groups. The levels of malondialdehyde, myeloperoxidase, and water content of lung tissue were all significantly increased in groups II and III when compared with group I at 1, 2, 4 and 6 h after reperfusion. They almost all returned to baseline at 24 h after reperfusion. However, there was no significant difference observed between groups II and III at either time point. A similar change in the process of lung ischemia-reperfusion injury was observed under light and electron microscopes in group II and in group III. Conclusions: The features of lung ischemia-reperfusion injury were similar when blocking the pulmonary artery and veins compared with blocking the pulmonary artery alone. Moreover, it might be safe to block the pulmonary vessels within 1 h during pulmonary surgery.