"It was important for us to test the long-term feasibility of these valves because they're going to be implanted and used for years," explained Ku. "But since test methods have not been well established for evaluating a prosthetic vein valve, we developed our own."
Sathe conducted the initial laboratory tests and found that the valve met the mechanical design criteria it could withstand pressures of more than 500 millimeters of mercury and opened with a pressure gradient of 2.6 millimeters of mercury, which matched physiologic vein valve function. Detailed laboratory testing procedures and results were described in the June 2007 issue of the Journal of Medical Devices.
Next, Farrell developed a laboratory method to test whether blood clots would form inside the prosthetic valve. Results showed that the new generation of valves remained open with no clot formation after 120 minutes of blood flow, whereas control valves lined with polyester closed up after approximately six minutes of perfusion and showed blood cells adhering to the valves.
The laboratory tests showed that the prosthetic vein valve exhibited low flow resistance, strong competency, fatigue-resistance, low clot formation probability and material flexibility, which allowed the researchers to move forward to the animal studies.
The next step after conducting the animal studies will be human clinical trials. The device will require an investigational device exemption from the Food and Drug Administration so that the device can be used in a clinical
|Contact: Abby Vogel|
Georgia Institute of Technology Research News