Abstract
We have evaluated anticoagulant activity of heparin immobilized onto hollow fiber oxygenators using a new heparin bonding method. The in vitro and ex vivo recirculation experiments have be done using bovine blood demonstrated that the heparin bioactivity as measured by the FXa assay maintained the initial bioactivity over the experimental period of up to 24 hrs. Both intra and extracapillary type oxygenators were then evaluated in an ex vivo chronic sheep model for extended periods under minimal systemic heparinization. The results showed excellent blood compatibility with minimal intra-device thrombus formation and minimal changes of coagulation parameters while maintaining the gas transfer capability throughout the experiment. Based on these results, the new heparin bonding method appears to be a reliable and effective method in the application to prolonged extracorporeal circulation system under minimal systemic heparinization.
