The Meadox unicusp pericardial bioprosthetic heart valve: new concept

To obtain a valve with better hemodynamic performance and longer durability than the currently available bioprostheses, a single-cusp pericardial xenograft has been developed. This valve has been tested extensively both in vitro, in a pulse duplicator and in a fatigue-testing system, and in vivo, in a series of dogs and sheep. Hemodynamic studies showed improved hemodynamic performance compared with other biological and mechanical valves. Effective orifice areas were larger and performance indexes higher, especially in the small sizes. Accelerated fatigue testing showed durability significantly superior to that of other biological devices. Animal experiments have established that the single cusp remains pliable even after more than two years of insertion. There is a low incidence of calcification and good preservation of the collagen matrix. This preliminary experience demonstrates that the unicusp pericardial xenograft has superior hemodynamics, increased resistance to fatigue-induced lesions, and a low incidence of calcification. These results might indicate an extended in vivo durability for this device.