Joseph B. Zwischenberger*, Wieke Tao, Donald J. Deyo, Roger A. Vertrees, Scott K. Alpard, Robert L. Brunston, Gerald Shulman
University of Texas Medical Branch
Galveston, Texas, USA
BACKGROUND AND METHODS
To evaluate safety and efficacy of a heparin removal device (HRD) in a swine model of 60-min, 28degrees Celsius cardiopulmonary bypass (CPB), 12 animals (60-100 kg) received HRD and six animals matched for weight received protamine as control. Plasma free hemoglobin (FHb), activated C3 (C3a), heparin concentration, ACT, APTT, anti-thrombin III, fibrinogen, heparinase thromboelastogram, and platelet count were measured. Tissue histology was evaluated 72 hours postoperatively.
RESULTS
All animals survived the three-day experiment without complications. The HRD run time for a targeted 90% heparin removal was 25-28 min. Heparin concentration immediately following CPB was 4.77
± 0.17 U/mL (ACT 776± 83 sec) in the HRD group and 3.94± 0.63 U/mL (694± 132 sec) in the protamine group, respectively (P=NS). Immediately after the HRD run, heparin concentration decreased to 0.45± 0.06 U/mL (ACT 180± 12 sec) in the HRD group and 0.13± 0.02 U/mL (ACT 101± 5 sec) in the protamine group, respectively (P=0.01 between groups). One hour after HRD run or protamine administration, there was no significant difference between groups. Other coagulation variables, FHb, and percent C3a were not significantly different between groups, nor were there significant histologic findings specific to the HRD or protamine.CONCLUSION
We conclude that HRD is safe and achieves predictable reversal of systemic heparinization following CPB.
