Fluiddynamics of autologous vein segment valves with and without external stents

Objectives: Treating aortic valve disease by the Ross procedure, shortage in homografts and re-operations due to graft degeneration are limitations of this therapy. Thus, a new approach with autologous valve bearing femoral vein segments should become created. Material and Methods: Autologous valve- bearing segments of the femoral vein from human cadavers were integrated into four tubes of vascular prostheses in a parallel order (group I, n=5) tested and compared with those having no external stents (group II, n=5) and others with a BioCompound mesh preserving the vein bulb. Data were compared with those of a mechanical Bj rk Shiley TAD 23 and St. Jude Medical 23. The valve tester delivered a stroke volume of 50ml and 64 beats per minute. Results: AVS-Valves With External Stent Group I AVS-Valves Without External Stent Group II AVS-Valves With BioCompound Group III Bj rk Shiley TAD 23 St. Jude Medical 23 Mean Pressure Gradient (mmHg) 16.3±3 12±2.2 9.6±0.2 12±0.3 6.4±0.2 Closing Volume (ml) 0.8±0.4 1.5±0.9 2.1±0.1 2.4±0.2 2.3±0.3 Leakage Volume (ml) 3.0±2.4 12.4±9.2 1.4±0.2 1.8±0.1 3.1±0.1 AVS-valves with Biocompound veins have the most favourable hemodynamics, comparable with frequently used mechanical heart valves. Conclusions: A new type of AVS – valves with an external stent mantaning the bulb configuration might become an option to replace a pulmonary homograft during Ross procedure, without shortage and late degeneration of the homograft.