Commentary: Miniaturized extracorporeal circulation, the “circuit-of-choice?”

Cardiopulmonary bypass (CPB), a prerequisite for major cardiac surgery, inevitably accompanies hemodilution and systemic inflammatory response syndrome that may contribute to impairments in the O 2 -carrying capacity, increased transfusion requirements, and multiorgan dysfunction, leading to increased risks of morbidity and mortality. 1 In addition, cardiotomy suction and blood air contact in a venous reservoir can also cause hemolysis and coagulopathy.Miniaturizedextracorporeal circulation (MECC) has been developed to minimize the drawbacks of CPB by attenuating systemic inflammatory response syndrome via limiting the blood–air interface and reducing the artificial tubing length with the renunciation of cardiotomy suction and a venous reservoir. 2 Most previous clinical studies, including several meta-analyses, have shown the potential benefits of MECC over conventional extracorporeal circulation (CECC) 3,4 ; however, these studies have failed to demonstrate overt benefits in terms of clinically relevant hard end points and also were not supported by subsequent large-scale studies. The use of MECC has therefore been still limited in clinical practice, with only 4 % to 10 % of op-erations using MECC. 5 Even more, the existence of MECC itself may still be unfamiliar to some cardiac surgeons. this issue of the Journal , Cheng and colleagues 6 sought to compare the outcomes between MECC and CECC through 42 randomized controlled trial involved 4340 patients coronary arterial bypass graft or heart valve surgeries. The authors found MECC signif-icantly reduces a composite incidence of postoperative mor-tality, stroke, renal failure, and myocardial infarction as compared CECC. In patients in the MECC group showed less postoperative atrial fibrillation, shorter hospital care stays, blood and lower levels of interleukin-6