Phosphorylcholine coating of extracorporeal circuits provides natural protection against blood activation by the material surface

Objective: The aim of this study is to evaluate the use of a new coating, m imicking the outer cell membrane, in paediatric cardiac surgery. Methods: Two groups of ten patients with a body weight below 8 kg, undergoi ng elective cardiac operations for different congenital anomalies. were pro spectively enrolled in this study. in one group the whole extracorporeal ci rcuit, including the cannulas, was coated with phosphorylcholine (PC). Ln t he second group the same circuit was used without coating. Platelet activat ion (thromboxane B2 (TXB2), beta -thromboglobulin (beta TG)), activation of the coagulation system (F1 + 2), leukocyte activation (CD11b/CD18) and ter minal complement activation (TCC) were analyzed pre-cardiopulmonary bypass (CPB), at 15, 60 min of CPB, at the end of CPB, 20 min post CPB and at post operative day 1 and 6. Results. No statistical differences were found for F 1 + 2 and CD11b/CD 18. After onset of CPB mean levels of TCC remained stabl e in the PC roup whereas an increase was observed in the control group. Dur ing CPB beta TG values in both groups increased to a maximum at the end of CPB. Within groups the increase in beta TG levels during CPB was statistica lly significant (P < 0.05) from baseline in the control group starting from 60 min of CPB whereas no statistical difference was observed in the PC gro up. After the start of CPB TXB2 mean levels increased to 405 +/- 249 pg/ml in the PC group vs. 535 +/- 224 pg/ml in the control group. After this init ial increase there was a small decline in the PC group with further increas e. This was in contrast to the control group were TXB2 levels further incre ased up to a mean of 718 +/- 333 pg/ml at the end of CPB (P = 0.016). Concl usions: Phosphorylcholine coating had a favourable effect on blood platelet s, which is most obvious after studying the changes during cardiopulmonary bypass. A steady increase of TXB2 and <beta>TG was observed in the control group, whereas plateau formation was observed in the phosphorylcholine grou p. Clinically, this effect may contribute to reduced blood loss and less th romboembolic complications. Complement activation is lower in the coated,gr oup. (C) 2000 Elsevier Science B.V.All rights reserved.