How minimalized extracorporeal circulation compares with the off-pump technique in coronary artery bypass grafting

Recognition of the adverse effects of conventional extracorporeal circulation (CECC) led to the development of alternative technologies and techniques to minimize their impact while maintaining circulation during coronary artery bypass grafting (CABG). Off-pump coronary artery bypass (OPCAB) grafting has become established as one such alternative and more recently minimalized extracorporeal circulation (MECC) circuits have been developed with the aim of providing circulatory support while minimizing the interface between blood and the foreign surfaces of the circuit that initiates the associated adverse effects of CECC. Recently, some authors have suggested that MECC may be an alternative to OPCAB in patients undergoing CABG; the aim of this article is to systematically analyze and compare the impact of CABG with MECC with that of OPCAB, studying the adverse outcomes related to CECC. We performed a systematic search to identify all studies directly comparing OPCAB and MECC. Endpoints were subcategorized into four key areas of interest: length of stay (LOS), hemorrhage, cerebrovascular injury, and 30-day mortality. Random effect modeling techniques were applied to identify differences in outcomes between the two groups. Six studies fulfilled the inclusion criteria, incorporating 2,072 patients of whom 930 underwent OPCAB and 1,142 underwent revascularization supported by MECC. We found no statistically significant difference in hospital or intensive care unit (ICU) LOS, blood loss, mean number of patients transfused, neurocognitive disturbance, or 30-day mortality between the two groups but a trend toward an increased number of cerebrovascular events in the MECC group was observed. The number of studies comparing these alternative techniques for coronary revascularization is small, and there is a lack of high-quality data. Currently, there seems little difference between MECC and OPCAB but larger randomized controlled trials focusing on high-risk patients are required.