Minimal versus conventional cardiopulmonary bypass: assessment of intraoperative myocardial damage in coronary bypass surgery

Abstract

Objective: Minimal extracorporeal circulation (mini-ECC) is a new technology, consisting of a centrifugal pump, an oxygenator, and a modified suction system. The main advantage of mini-ECC is the reduction of tubing length (reduction of the priming volume). Additional beneficial effects are a decrease of coagulation cascade and a reduction of blood transfusion in patients undergoing coronary artery bypass grafting (CABG) surgery. We compared the intraoperative and early postoperative myocardial damage and outcome of patients who underwent CABG surgery with conventional cardiopulmonary bypass (CPB) or mini-ECC. Methods: One hundred and thirty-six consecutive patients who underwent isolated CABG surgery at our institution were prospectively studied. Fifty-four patients (39.7%) were operated with mini-ECC. Patient characteristics were similar in both groups. The most interesting intraoperative details as well as in-hospital outcome were assessed. Results: There was no difference in mortality between the two groups. Cross-clamping time was similar in both groups (p = 0.07). Defibrillation was required in one patient in the mini-ECC group (1.9%) and in 38 patients (46.3%) in the CPB group (p < 0.001). In the mini-ECC group, the requirement of inotropic support and incidence of atrial fibrillation was significantly lower than in the CPB group. Postoperative creatine kinase isoenzyme MB (CK-MB) and cardiac Troponin I (cTnI) were significantly lower in the mini-ECC group (p < 0.05). Duration of ventilation, length of stay in the intensive care unit and total hospitalization time were significantly shorter in patients operated with mini-ECC (p < 0.05). Conclusion: Mini-ECC is a safe procedure and is followed by a diminished release of CK-MB and cTnI than after CPB. Postoperative recovery is accelerated following mini-ECC and there is a significantly lower incidence of postoperative atrial fibrillation.