RESUMO
BACKGROUND: Jehovah's Witnesses who require cardiac surgery represent a challenge to the physician because of their refusal to accept blood transfusions. Because coronary artery bypass grafting (CABG) is performed by most surgeons under cardiopulmonary bypass (CPB), which has potentially deleterious effects on hemostasis, we used a new concept called minimal extracorporeal circulation (MECC). MECC includes heparin-coated tubing, a centrifugal pump, and an oxygenator. There is no venous reservoir or vent, and suction is used through the cell saver. We assessed the hypothesis that MECC in combination with low-volume blood cardioplegia preserves more hemoglobin than conventional CPB in standard CABG. METHODS: In 40 patients of the Jehovah's Witnesses faith undergoing CABG with the use of MECC and intermittent warm blood cardioplegia, clinical and biological data as well as values for parameters of hemolysis (plasma hemoglobin) and myocardial damage (troponin T) were determined. The results were compared with those of a control group of 40 patients who underwent operations with standard CPB. RESULTS: Demographics, hemodynamics, the number of anastomoses, and CPB and cross-clamp times were comparable between the groups. MECC patients demonstrated significantly lower peak levels of plasma hemoglobin (21.8 +/- 114 mg/dL versus 35.4 +/- 15 mg/dL) and troponin T (0.12 +/- 0.4 ng/mL versus 0.65 +/- 0.7 ng/mL), a higher minimum hematocrit level during CPB (30% +/- 7% versus 23% +/- 6%), and a higher hemoglobin level 2 days after surgery (13 +/- 3 g/100 mL versus 9.4 +/- 0.98 g/100 mL). Preoperative values were not significantly different. CONCLUSION: The use of MECC instead of conventional CPB reduces hemolysis, hemodilution, blood loss, and myocardial damage.
