Granulocyte Phagocytic Function Is Impaired During Cardiopulmonary Bypass

Background. The presence of impaired phagocytic function of the reticuloendothelial system after cardiac operations using cardiopulmonary bypass remains controversial. Methods. In this study, the phagocytic function of granulocytes in 14 patients undergoing cardiac operations with cardiopulmonary bypass was examined using a chemiluminescence method. Seven patients with abdominal aortic aneurysms served as controls. Electron microscopy also was employed to evaluate morphologic changes. Results. The 14 cardiac patients showed impaired phagocytic function from immediately after operation until 12 hours after the operation. This phagocytic function recovered within 24 hours. The 7 control patients showed no change in phagocytic function during or after the operation. Scanning electron microscopic examination of the cardiac patientsʹ granulocytes revealed the loss of villi on cell surfaces immediately after operation. However, these villi were restored within 24 hours after the operation. Conclusions. The phagocytic function of granulocytes was impaired in the early postoperative period in patients undergoing cardiopulmonary bypass, and this was probably due to the loss of villi on granulocyte surfaces.