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.