Performance changes of venous valves following tissue treatment with novel in vitro system

OBJECTIVES: The purpose of this study is to test venous valve performance and identify differences between native tissue and replacement devices developed with traditional tissue treatment methods using a new in vitro model with synchronized hemodynamic parameters and high-speed valve image acquisition. METHODS: An in vitro model mimicking the venous circulation to test valve performance was developed using hydrostatic pressure driven flow. Fresh and glutaraldehyde-treated vein segments were placed in the setup and opening/closing of the valves was captured by a high-speed camera. Hemodynamic data were obtained using synchronized hardware and virtual instrumentation. RESULTS: Geometric orifice area and opening/closing time of the valves was evaluated at the same hemodynamic conditions. A reduction in geometric orifice area of 27.2 ± 14.8% (p < 0.05) was observed following glutaraldehyde fixation. No significant difference in opening/closing time following chemical fixation was observed. CONCLUSIONS: The developed in vitro model was shown to be an effective method for measuring the performance of venous valves. The observed decrease in geometric orifice area following glutaraldehyde treatment indicates a decrease in flow through the valve, demonstrating the consequences of traditional tissue treatment methods.