Is there really a clinical benefit of using minimized extracorporeal circulation for coronary artery bypass grafting?

Background: Minimized extracorporeal circulation is intended to reduce the negative effects associated with cardiopulmonary bypass. This prospective study was performed to evaluate whether minimized extracorporeal circulation has a clinical benefit for coronary artery surgery patients compared to standard extracorporeal circulation. Methods: Sixty patients were randomized into two study groups: 30 patients underwent coronary artery bypass grafting using minimized extracorporeal circulation and 30 patients were operated using standard extracorporeal circulation. Baseline characteristics, intraoperative details, postoperative data, perioperative blood chemistry determinations of hematocrit, platelets, muscle-brain fraction of the creatine kinase, cardiac troponin T and colloid osmotic pressure as measurements of intrathoracic blood volume index and extravascular lung water index were compared. Results: Baseline characteristics and intraoperative details of both groups were similar. Patients who underwent minimized extracorporeal circulation showed more short-term dependency on norepinephrine (p < 0.01). Their maximal postoperative muscle-brain fraction of the creatine kinase was lower (p < 0.05) and their hematocrit on arrival in the intensive care unit was higher (p < 0.01). No other significant differences were found. in both collectives, values for hematocrit (p < 0.001), platelets (p < 0.001), colloid osmotic pressure (p < 0.001) and intrathoracic blood volume index (p<0.05) decreased, while the extravascular lung water index did not change significantly during cardiopulmonary bypass. Conclusions: A clinical advantage of minimized over standard extracorporeal circulation was not found. Furthermore, a higher number of patients in the minimized extracorporeal circulation group required postoperative norepinephrine infusions for hemodynamic stabilization. In summary, the presumed superiority of minimized extracorporeal circulation for coronary artery bypass grafting in standard patients could not be confirmed.