Changes of leukocyte subsets in coronary artery bypass surgery:: Cardiopulmonary bypass versus 'off-pump' techniques

Background: The use of cardiopulmonary bypass (CPB) in coronary bypass grafting is associated with a generalized inflammatory response. This negative impact of CPB may be avoided by using new surgical techniques recently introduced to perform coronary bypass grafting 'off-pump', i.e. without CPB. Methods: Since the specific effects of CPB on the immunorelevant cells have still not been fully investigated, we measured the changes in leukocyte subsets of the circulating blood in patients who underwent coronary bypass surgery with a conventional sternotomy approach and CPB (group A, n = 10), in patients who underwent the same surgical procedure but without CPB (group B, n = 10), and in patients who underwent a minimally invasively performed single bypass to the left anterior descending artery (LAD) (group C, n = 10). Results: Leukocyte subsets showed a similar change during and after coronary bypass grafting in all three groups. The total number of leukocytes was increased soon after reperfusion in the CPB group. A similar but delayed increase was observed in both off-pump groups, Changes in lymphocyte subsets and T-lymphocyte subsets were similar in all three groups, with a drop of lymphocytes during the first 24 postoperative hours mainly caused by a drop of T4-helper cells. Conclusion: The results indicate a reaction of the leukocyte subsets to coronary bypass surgery which is more related to the surgical trauma in general than to CPB in particular.