Heparin-coated cardiopulmonary bypass circuits in coronary bypass surgery

Cardiopulmonary bypass (CPB) is a nonphysiologic environment for an organism. The damage of blood components may also lead to organ dysfunction, some-times recognized as postperfusion syndrome. One possible way to diminish the risk of these complications would be to reduce the thorombogenicity and to improve the biocompatibility of the artificial surfaces by using a heparin-coated CPB circuit. In this study, we compared a heparin-coated CPB circuit with a noncoated CPB circuit in terms of biocompatibility in 20 patients undergoing elective coronary bypass surgery. We employed a Duraflo II (n = 10) as a heparin-coated CPB circuit and a Univox IC (n = 10) as control subjects. Ten patients (Group C) were operated on using the heparin-coated CPB circuit. A total of 10 patients were given heparin in a reduced dose (2.0 mg/kg), and additional heparin was given if the activated clotting time (ACT) was below 400 s. The control group also included 10 patients (Group NC), who were operated on with noncoated devices. They received 2.5 mg/kg of heparin, and additional heparin was given if the ACT was below 450 s. All patients had normal coagulation parameters and did not receive blood transfusion. We measured complement activation levels (C3a, C4a), platelet count, thrombin-antithrombin III complex levels, D-dimer levels, and ACT during CPB and respiratory index postoperatively. The concentration of C3a in group NC was significantly higher than that in group C. Platelet reduction in group NC was significantly greater than that in group C. There were no significant differences in the remaining parameters between the 2 groups. We concluded that heparin-coated CPB circuits improved biocompatibility by reducing complement activation and platelet consumption and enabled us to reduce the dose of heparin required for systemic heparinization.