The Gyro C1E3 is a centrifugal blood pump. Its antithrombogenic and antitra
umatic blood features were demonstrated by prior studies. Based upon these
studies, a mass production model of the C1E3 is becoming commercially avail
able. Therefore, this feasibility study was conducted using the mass produc
tion models of the Gyro C1E3 for long-term cardiac assist in ex ville anima
l experiments. Five healthy calves were used and 15 pump heads were applied
for different time periods (Group 1, 30 days; Group 2, 14 days; Group 3, 1
0 and 7 days; Group 4, 4 days; and Group 5, 2 days). Activated clotting tim
e (ACT) was kept at 200-250 sec. All five calves demonstrated neither abnor
mal signs nor abnormal blood examination data throughout the experiment. Du
ring necropsy, no thromboembolism was found in any downstream organs. Group
s 1-4 showed thrombi inside the pump heads while two pumps in Group 5 had n
o thrombi formations. Bearing deformation or possible wear did not increase
after 2 days of pumping. The C1E3 is capable of long-term assist circulati
on. However, after 2 days of pumping, careful observation is necessary sinc
e thrombi may occur inside the pump when ACT is controlled under 250 sec. D
uring the weaning stage or low flow (under 2 L/min), over 250 sec of ACT is
recommended to assure the safety of the patient.