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

We studied postoperative mortality and morbidity after coronary artery bypass graft surgery performed using the mini-extracorporeal circulation (MECC) system.

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.

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.

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.