MECHANICAL CHARACTERISTICS OF LYOPHILIZED HUMAN SAPHENOUS-VEIN VALVES

Purpose: We investigated the mechanical characteristics of lyophilized human saphenous vein valves to determine their suitability for use as allogeneic transplants to treat chronic venous insufficiency. Methods : Fresh cadaveric veins were lyophilized in vacuum bottles within 24 h ours of harvest and were stored at room temperature. The veins were re constituted in saline solution and then were placed in an in vitro flo w circuit for evaluation. At varied how rates, pressures proximal and distal to valves during prograde and retrograde now were measured. Val ve closure times were determined with Doppler examination and spectral analysis. The valves were also stressed to 350 mm Hg on a separate ap paratus. Results: All pressures proximal and distal to the valves rema ined less than 10 mm Hg during prograde flow. A pressure gradient deve loped immediately on the reversal of flow. Pressure as high as 200 mm Hg applied against the dosed valves was not transmitted beyond the val ve. Valve closure times had a mean of 0.31 +/- 0.03 seconds and 0.21 /- 0.01 seconds for the Doppler examination and spectral analysis, res pectively. All valves withstood stress pressures to 350 mm Hg. Conclus ions: The in vitro mechanical characteristics of the valves of lyophil ized veins are similar to known values for normal in vivo valves.