Experimental evaluation of the V-point heparin-bonding system applied to adense-membrane artificial lung during 24-hour extracorporeal circulation in beagles

Heparin was covalently bonded to a hollow-fiber dense-membrane artificial l ung and circuit using a silane coupling agent and polyethyleneimine as a sp acer. This study investigated whether the novel artificial lung could susta in prolonged extracorporeal lung assist (ECLA) by venoarterial bypass in be agles using minimal anticoagulants. We maintained ECLA for 24 h in 3 groups of minimal systemic heparinization, heparinization with the new anticoagul ant nafamostat mesilate, and without any systemic anticoagulant. The result s were assessed from the functional performance of the artificial lung and by macroscopic and microscopic examination after the experiments. Artificia l lung function, hemodynamics, hemogram, and platelet aggregation activity were well maintained in all groups. There was no plasma leakage from the ar tificial lung. Although several clots were observed in stagnant areas of th e artificial lungs and circuits, there was no clot formation inside the art ificial lung in any group. This highly biocompatible, heparin-bonded dense- membrane artificial lung performed well and safely during prolonged ECLA wi th blood clotting times less than 120 s.