Mini-cardiopulmonary bypass system: Results of a prospective randomized study

Background. We studied postoperative mortality and morbidity after coronary artery bypass graft surgery performed using the mini - extracorporeal circulation ( MECC) system. Methods. From June 2001 to June 2002, we randomly enrolled 60 patients who underwent isolated elective coronary artery bypass graft surgery, and were operated on with the MECC system ( 30 patients: group A) or standard cardiopulmonary bypass ( 30 patients: group B). Serial blood samples were collected to evaluate the main preoperative, intraoperative, and postoperative clinical and biological variables; and to measure hemolysis, interleukin-6 cytokine, and plasma C- reactive protein release. Results. A more stable hemoglobin level was detected in group A. The platelet count did not show a significant difference between the two groups. Interleukin- 6 cytokine release showed higher values in group B, although no difference between groups was statistically significant. The time course of circulating plasma C- reactive protein concentration exhibited the same increase in both groups. Plasma free hemoglobin levels showed higher hemolysis peaks in group B, although a statistical significant difference was detected only at 4 hours after surgery. A higher cardiac index and reduced systemic and pulmonary vascular resistance index in the early postoperative period were found in group A at postoperative time 30 minutes. Conclusions. Our experience shows that MECC offers satisfactory clinical benefits in terms of good hemodynamic support, safety, and low morbidity, although the study failed to demonstrate a significant clear superiority of MECC versus conventional cardiopulmonary bypass. The results need to be confirmed by a larger prospective, randomized study comparing MECC and standard cardiopulmonary bypass.