Background: The aim of this study was to evaluate the protective effect of pulmonary perfusion with hypothermic protective solution on lung function after cardiopulmonary bypass in corrections of Tetralogy of Fallot.
Methods: Sixty-four consecutive children with Tetralogy of Fallot were randomly divided into a control group (n = 30) and a protective group (n = 34). Hypothermic protective solution was infused to the main pulmonary artery in the protective group. Hemodynamics and lung functions were monitored. Concentrations of malondialdehyde, tumor necrosis factor-alpha, von Willebrand factor, and endothelin in plasma were measured. The interleukin-6 and interleukin-8 levels in bronchoalveolar lavage fluid were also determined. Lung biopsy specimens were obtained after weaning from cardiopulmonary bypass.
Results: Oxygenation values (oxygen index and alveolar-arterial O(2) gradient) were better preserved in the protective group than in the control group. The time of mechanical ventilation and length of intensive care unit stay were shorter in the protective group compared with the control group. The tumor necrosis factor-alpha and malondialdehyde levels in plasma increased in both groups after operations, and the rising extents were lower in the protective group than in the control group. The von Willebrand factor and endothelin levels in plasma increased more significantly in the control group than in the protective group. The concentrations of interleukin-6 and interleukin-8 in bronchoalveolar lavage fluid were lower in the protective group than in the control group. The examination of histopathology demonstrated capillary hyperemia and hemorrhage, intra-alveolar edema, leukocytes accumulation, mitochondria swelling and vacuolation, and gas-blood barrier broadening in the control group, whereas there were no significant changes in the protective group. The intercellular adhesion molecule-1 expression on lung vascular endothelial cells was stronger in the control group.
Conclusions: Lung perfusion with hypothermic protective solution during cardiopulmonary bypass relieved lung injury in corrections of Tetralogy of Fallot. The inhibition of lung vascular endothelial cell injury may be the major mechanism of relieving cardiopulmonary bypass-induced lung injury.