Miniaturize CPB Versus Off-Pump Surgery

Abstract

Off-pump coronary artery bypass grafting (OPCABG) surgery has been accepted since the early 1990s when it was recognized that conventional extracorporeal circulation (cECC) is associated with a systemic inflammatory response syndrome (SIRS). SIRS is implicated in myocardial, renal, pulmonary, and neurologic dysfunction. For these reasons, the OPCABG technique is widely applied as the first choice in patients affected by acute or chronic renal dysfunction, obstructive pulmonary disease, cerebrovascular disease, and peripheral obstructive arteriopathy [1]. However, although the effects of cECC are often subclinical, in some situations they can be responsible for worse outcomes in the early postoperative period. OPCABG has produced very encouraging results, and this technique has seen wide popularity during the last decade, with many cardiac centers performing OPCABG in more than 80 % of coronary patients [2]. However, the OPCABG technique presents some drawbacks, such as the significant learning curve for the surgeon, the high rate of incomplete revascularization in dilated and hypokinetic hearts due to the very difficult exposure of obtuse coronary marginal branches, and the lesser quality of the coronary anastomosis with an increased graft restenosis identified [3, 4]. Over the past 10 years, miniaturized extracorporeal circulation (MECC) has been developed with the aim of reducing the side effects of cECC, strengthening the advantages of cECC, and eliminating the drawbacks of OPCABG [5, 6]. Utilizing a shorter circuit without the interposition of a venous reservoir may offer several benefits, such as a reduction in hemodilution, coagulopathy, and SIRS. In other words, MECC should combine the best of cECC with the best of “off-pump” surgery. However, it is not yet clear whether the combination of these advantages is superior in MECC compared to OPCABG in terms of mortality and morbidity because multicenter randomized studies currently are lacking.