Effect of heparin anticoagulation on the antithrombogenicity of an extracorporeal membrane oxygenation system under veno-arterial bypass in an animal model.

An extracorporeal membrane oxygenation (ECMO) system consisting of a heparin-coated membrane oxygenator with polymethylpentene hollow fiber membranes and a heparin-coated hydrodynamically levitated centrifugal pump was developed. The effect of heparin anticoagulation on the antithrombogenicity of the ECMO system under veno-arterial bypass was evaluated in an animal model. Veno-arterial bypass with the ECMO system was induced in goats. Ten goats were evaluated which were divided into heparin anticoagulation-free (HPF; n = 5) and heparin anticoagulation (HP; n = 5) groups. Evaluation of the ECMO system focused on thrombus formation and changes in blood test data. Veno-arterial bypass with the ECMO system was maintained for 2 weeks in both groups. The extent of thrombus formation in the oxygenators was suppressed in the HP group. The centrifugal pumps were free of major thrombus formation in both groups. From baseline to postoperative day (POD) 1, both groups showed significant decreases in platelet counts, with a significant reduction in von Willebrand factor (vWF) activity levels in the HPF group. Between PODs 1 and 14, POD differences were observed in platelet counts without group or interaction differences. The levels of vWF activity showed significant group differences, with the HPF group demonstrating lower values than the HP group, but no significant POD or interaction differences. Veno-arterial bypass with the ECMO system was sustained for 2 weeks regardless of heparin anticoagulation. Heparin anticoagulation suppressed the extent of thrombus formation in the oxygenators. The centrifugal pumps were free of major thrombus formation regardless of heparin anticoagulation.