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 graf ting is associated with a generalized inflammatory response. This negative impact of CPB may be avoided by using new surgical techniques recently intr oduced to perform coronary bypass grafting 'off-pump', i.e. without CPB. Me thods: Since the specific effects of CPB on the immunorelevant cells have s till not been fully investigated, we measured the changes in leukocyte subs ets of the circulating blood in patients who underwent coronary bypass surg ery with a conventional sternotomy approach and CPB (group A, n = 10), in p atients who underwent the same surgical procedure but without CPB (group B, n = 10), and in patients who underwent a minimally invasively performed si ngle bypass to the left anterior descending artery (LAD) (group C, n = 10). Results: Leukocyte subsets showed a similar change during and after corona ry bypass grafting in all three groups. The total number of leukocytes was increased soon after reperfusion in the CPB group. A similar but delayed in crease 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 l ymphocytes during the first 24 postoperative hours mainly caused by a drop of T4-helper cells. Conclusion: The results indicate a reaction of the leuk ocyte subsets to coronary bypass surgery which is more related to the surgi cal trauma in general than to CPB in particular.