Prosthetic trileaflet heart valve

A trileaflet prosthetic heart valve including

• a generally annular valve body having a smoothly flared upstream entrance end which leads to an interior wall of generally circular cross-section, which wall defines a central passageway for blood flow therethrough having a central longitudinal axis extending in an upstream-downstream direction, and having three projections which extend radially into said central passageway at 120.degree. intervals, said projections each having a pair of flat surfaces that are aligned at about 120.degree. to each other, said entrance end having an interior convex surface with a radius of curvature equal to between about 28% and about 80% of said central passageway radius,
• three cooperating leaflets, each having an arcuate upstream edge surface, a pair of downstream edge surfaces, and a pair of parallel lateral edge surfaces,
• said leaflets being mounted in said valve body to alternate between an open position where flow of blood in a downstream direction is permitted and a closed position where flow of blood in an upstream direction is blocked, said leaflets each having opposite inflow and outflow surfaces with said inflow surface facing upstream and said outflow surface facing downstream in the closed position, and
• a pivot arrangement by which said leaflets are guided in moving between said open position and said closed position, which pivot arrangement permits each of said leaflets to assume an orientation substantially parallel to said central longitudinal axis in the open position during downstream blood flow and to close by pivoting therefrom upon reverse flow of blood in an upstream direction in such a manner that said downstream edges of said leaflets swing upstream toward said central longitudinal axis in moving to the closed position,
• said pivot arrangement comprising ridges having upstream and downstream ends and associated upstream posts protruding from respective of said flat surfaces of each of said projections and notches formed in said parallel lateral edge surfaces of said leaflets, which notches are shaped to straddle said ridges and to translate therealong,
• said ridges each being generally curved to define a path which extends radially inward and upstream from the downstream end thereof and said ridges being proportioned so that the downstream ends thereof are enlarged in cross-section relative to said upstream ends,
• said notches being proportioned so as to be oversize with respect to the cross-section of upstream ends of said ridges so that said leaflets are readily displaceable along said ridges so as to swing generally upstream along a path defined by said ridges upon the reversal of normal downstream flow of blood through the valve, and said notches also being proportioned to engage said enlarged downstream ends in a manner so as to stop each said leaflet in said substantially parallel open position orientation with said inflow surfaces in contact with said upstream posts.