Heparin-coated equipment reduces complement activation during cardiopulmonary bypass in the pig

Complement activation was studied during cardiopulmonary bypass (CPB) in the pig. One group of animals was perfused for 2 h using a standard extracorporeal circuit including a hollow fiber membrane oxygenator with full systemic heparinization. Another group was treated in the same way, except that bypass was performed through a heparin-coated CPB circuit (Carmeda Bio-Active Surface, CBAS) and systemic heparinization was reduced by 75%. It was found that complement activation during CPB, measured as changes in the ratio C3d/C3, was significantly less in the CBAS group, most probably reflecting a better biocompatibility.