Evaluation of hemodynamic and regional tissue perfusion effects of minimized extracorporeal circulation (MECC).

Minimized extracorporeal circulation (MECC, Maquet, Cardiopulmonary AG, Hirrlingen, Germany) is an established procedure to perform coronary revascularization. Studies showed positive effects of MECC compared to conventional cardiopulmonary bypass (CCPB) procedures in terms of transfusion requirements, less inflammation reactions, and neurological impairments. Recent retrospective studies showed higher mean arterial pressure (MAP) and a lower frequency of vasoactive drug use. We addressed this issue in this study. The hypothesis was to find a higher MAP during coronary bypass grafting surgery in patients treated with MECC systems. We performed a prospective, controlled, randomized trial with 40 patients either assigned to MECC (n = 18) or CCPB (n = 22) undergoing coronary bypass grafting. Primary endpoints were the perioperative course of mean arterial pressure, and the consumption of norepinephrine. Secondary endpoints were the regional cerebral and renal oxygen saturation (rSO2) as an indicator of area perfusion and the course of hematocrit. Clinical and demographic characteristics did not significantly differ between both groups. Thirty-day mortality was 0%. At four of five time points during extracorporeal circulation (ECC) MAP values were significantly higher in the MECC group compared to CCPB patients (after starting the ECC 60 +/- 11 mmHg vs. 49 +/- 10 mmHg, p = .002). MECC patients received significantly less norepinephrine (MECC 22.5 +/- 35 microg vs. CCPB 60.5 +/- 75 microg, p = .045). The rSO2 measured at right and left forehead and the renal area was similar for both groups during ECC and significantly higher at CCPB group 1 and 4 hours after termination of CPB. Minimized extracorporeal circulation provides a higher mean arterial pressure during ECC and we found a lower consumption of vasoactive drugs in the MECC group. There was a decrease in regional tissue saturation at 1 and 4 hours post bypass in the MECC group possibly due to increased systemic inflammation and extravascular fluid shift in the CCPB group.

Minimal extracorporeal circulation and off-pump compared to conventional cardiopulmonary bypass in coronary surgery.

OBJECTIVES: Although minimal extracorporeal circulation (MECC) and off-pump surgery are equal or better alternatives to conventional cardiopulmonary bypass (CCPB) regarding perioperative morbidity, use of blood and blood products and completeness of revascularization, CCPB is still being used in the majority of coronary artery bypass grafting (CABG) operations. METHODS AND RESULTS: We investigated 1472 CABG operations in our center. A total of 1143 CABG operations were performed using CCPB, 220 using MECC and 109 were performed as off-pump coronary artery bypass (OPCAB). All patients were recorded prospectively. Perioperative follow-up was focused on the occurrence of arrhythmia, neurocognitive disorders and the need of blood and blood products. Operative mortality rates were comparable in all three groups. The mean number of distal anastomoses was 3.2+/-0.6 in the MECC group, 3.4+/-0.7 in the CCPB group and 1.9+/-0.8 in the OPCAB group (P=0.01). Arrhythmia occurred in 25% of the MECC group and in 35.6% of the CCPB group (P=0.05). Arrhythmia occurred in 21.7% of the OPCAB group. Seven patients (3%) of the MECC group suffered neurocognitive disorders perioperatively compared to 74 (7%) patients of the CCPB group (P=0.05) and three patients of the OPCAB group (3%). The median number of blood transfusions per patient was 0.8 in the MECC group, 1.8 in the CCPB group and 0.8 in the OPCAB group (P<0.0001). CONCLUSIONS: Perioperative morbidity of MECC and OPCAB is comparable to or even less in comparison to CCPB. MECC allows CABG surgery in cardiac arrest so that completeness of revascularization is being warranted and longer patency rates can be guaranteed. Furthermore, the use of blood and blood products is significantly less in MECC surgery so that MECC should be considered first choice in CABG surgery over CCPB and OPCAB.