Comparison of inflammatory response during on-pump and off-pump coronary artery bypass surgery

Purpose: On-pump coronary artery bypass graft (CABG) surgery has been traditionally associated with a higher magnitude of inflammatory response than off-pump CABG. However, with the development of polymer-coated biocompatible extracorporeal circuits, we wanted to see if cardiopulmonary bypass still played an important role in triggering this inflammatory response. Methods: In this prospective observational study, 33 patients undergoing CABG surgeries (25 on-pump and 8 off-pump patients) were studied. Serial plasma cytokine (TNF, IL-6, IL-10) and procalcitonin concentrations were measured at different time-points during and after the surgery. Demographic and baseline clinical data, intra-operative management details and post-operative complications were also collected from the patients' charts. Results: Plasma levels of all 4 mediators increased during surgery and returned towards normal post-operatively. There were no differences between groups for any mediator at any time-point. Conclusions: We conclude that with the use of recent polymer-coated biocompatible extracorporeal circuits, the inflammatory response triggered by on-pump CABG becomes very similar in magnitude and pattern to that triggered by off-pump CABG. Thus, the surgical procedure contributes to most of the inflammatory response, with the extra-corporeal circuit having minimal to no effect on this response. (Int J Artif Organs 2010; 33: 131-8)