Methods: Eight adult sheep hearts were used for testing our technique`s reliability. After perferming of tests on these hearts with competent aortic valve (Group A), iatrogenic aortic valve insufficiency were created on the same hearts (Group B) and the tests were repeated. Then hearts with insufficient valves were repaired by flap-valve method (Group C) and the same tests were repeated.

Different stress conditions were simulated by applying three different hydrostatic pressures with order using centrifugal pump. The pressures were monitored in ventricular side of the aortic valve (P1), aortic lumen (P2) and the left coronary ostium (P3).
Condition 1: A pulsatile 140 mmHg pressure with 80 / min frequency was applied from the ventricular side of the valves.
Condition 2: A continuous 140 mmHg pressure was applied from the ventricular side of the valves.
Condition 3: A continuous hydrostatic pressure was applied as P2 = 180 mmHg, and P1 pressure was discontinued abruptly.

Results: From the pressure changes, it was understood that the aortic valve insufficiency was created in Group B. This insufficiency is improved in the group that treated by flap-valve method. While aortic valves opened 15 mmHg-gradient in Group A, this gradient increased to 30 mmHg in Group C. However, we assume that gradient is acceptable. Flap-valve did not interfere with coronary blood flow.

Conclusions: Flap-valve is found effective in vitro environment.