Development of an antithrombogenic and antitraumatic blood pump: the Gyro C1E3

The Gyro C1E3 is a centrifugal blood pump. Its antithrombogenic and antitraumatic blood features were demonstrated by prior studies. Based upon these studies, a mass production model of the C1E3 is becoming commercially available. Therefore, this feasibility study was conducted using the mass production models of the Gyro C1E3 for long-term cardiac assist in ex vivo animal 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, 10 and 7 days; Group 4, 4 days; and Group 5, 2 days). Activated clotting time (ACT) was kept at 200-250 sec. All five calves demonstrated neither abnormal signs nor abnormal blood examination data throughout the experiment. During necropsy, no thromboembolism was found in any downstream organs. Groups 1-4 showed thrombi inside the pump heads while two pumps in Group 5 had no thrombi formations. Bearing deformation or possible wear did not increase after 2 days of pumping. The C1E3 is capable of long-term assist circulation. However, after 2 days of pumping, careful observation is necessary since thrombi may occur inside the pump when ACT is controlled under 250 sec. During the weaning stage or low flow (under 2 L/min), over 250 sec of ACT is recommended to assure the safety of the patient.