Evolution of mechanical heart valves

Durability Assessment of Polymer Trileaflet Heart Valves

“…Research International [20], it was reported that mechanical valves had lost a portion of the market share to the bioprosthetic valves, whose further development has increased their expected durability. In the 2002 report, mechanical valves only accounted for 40% of the market, with the St. Jude bileaflet valves still being the most popular.…”

Static and dynamic mechanical testing of a polymer with potential use as heart valve material

“…pivot between open and closed positions. The cage of these valves was made of titanium, while the disc was made of Pyrolyte (DeWall, Qasim et al 2000). In some instances, with older models, the strut completely separated from the valve ring, and catastrophic disc embolization occurred.…”

“…In some instances, with older models, the strut completely separated from the valve ring, and catastrophic disc embolization occurred. These older models were withdrawn from the domestic market in 1988 (DeWall, Qasim et al 2000).…”

“…Opening angles of the leaflets approach 90 degrees, improving valve hemodynamics. The St Jude bileaflet valve is now the most commonly implanted mechanical heart valve (DeWall, Qasim et al 2000).…”

Modification of a novel polymer with potential use in artificial heart valves : effects on hemocompatibility and mechanical properties

“…One of the disadvantages of this heart valve was that the silicone rubber would swell up by absorbing fluids in vivo and therefore would be stuck in the cage. Ball and cage valves exhibit non-central flow characteristics, where the ball blocks the central flow thereby causing the blood to flow around the ball (DeWall, 2000). This results in an increase in stress on the heart, as the heart has to do additional work to compensate for the energy lost due to the change in the direction of the blood.…”