Heparin-coated circuits reduce complement activation and inflammatory response to cardiopulmonary bypass

Background. Clinical procedures involving extracorporeal blood circulation are potentially complicated by the interaction of various blood systems wit h foreign surfaces. In cardiopulmonary bypass, exposure of blood to synthet ic surfaces generally leads to activation of cellular and humoral blood sys tems with activation of complement cascade. This reaction can be associated with a variety of postoperation clinical complications such as increased p ulmonary capillary permeability, anaphylactic reactions and various degrees of organ failure which contributes to mortality in routine cardiac operati ons. Application of biocompatible materials in an extracorporeal circuit mo difies the normal pattern of blood activation, and therefore potentially ma y reduce clinical complications in routine cardiac surgery. Methods. To evaluate whether the use of heparin coated extracorporeal circu its could reduce this activation process we performed a study on forty coro nary artery bypass graft patients perfused randomly with heparin-coated cir cuits (Duraflo II, n=20) or with non-coated circuits (De Bakey roller pump, control n=20), Standardized heparinization was maintained for both groups of patients during cardiopulmonary bypass. Results. The use of heparin-coated circuits resulted in reduction of system ic leukocyte activation of cardiopulmonary bypass reflected by reduced leuk ocyte and neutrophil counts 24 hours after operation (p<0.05), Furthermore, blood samples taken from both the right and left atrium after reperfusion revealed that the differences in neutrophil counts between the right and le ft atrium occur less in the heparin-coated circuit in contrast to the contr ol group (p<0.05). The pattern of complement activation, probably initiatin g this inflammatory reaction, was modified by heparin coating in two differ ent aspects. There was a significant reduction of C3 during and after cardi opulmonary bypass in patients perfused with heparin coated circuits as comp ared with the control group, also there was reduction of C4 after protamine administration in the same groups (p<0.05), The reductions in blood and co mplement activation with heparin-coated circuit indicate a substantial impr ovement in biocompatibility, and consequently reducing clinical complicatio ns associated with cardiopulmonary bypass. Conclusions. In conclusions using the Duraflo II heparin-coated circuit in open heart surgery can reduce the complement activation and inflammatory re sponse to cardiopulmonary bypass.