Experimental evaluation of a heparin coated ECMO system simplified with a centrifugal pump

A heparin coated cardiopulmonary bypass system was evaluated for canine veno-venous extracorporeal membrane oxygenation (ECMO). The ECMO system consisted of a hollow fiber membrane oxygenator and pediatric centrifugal pump but no reservoir. In Group 1 (N = 6), the ECMO system was coated with a covalent, heparin-binding method, except for the centrifugal pump, and animals underwent ECMO without systemic heparinization. In Group 2 (N = 4), the same system without the heparin coating was used under full heparinization. During 12 hours of ECMO with a bypass flow of 500 ml/min, there were no significant differences in gas exchange or blood trauma between the two groups. There was no apparent macroscopic thrombus formation in either group. In addition, it was suggested that Group 1 had less activation of platelets on the blood-contacting surfaces compared with Group 2. This ECMO system, with simplified circuits using a centrifugal pump, showed efficient gas exchange and antithrombogenicity when coated with heparin using a covalent binding method comparable to the non heparin coated system requiring systemic heparinization.