Low gradient prosthetic heart valves

Abstract

A low pressure gradient prosthetic heart valve for implant in a human. The valve includes a support frame with undulating inflow cusps and outflow commissure posts to which flexible leaflets attach and coapt in a flow area. The commissure posts angle outward in a neutral state to widen the outflow orifice area. Also, the leaflets are designed to fit within the support frame and expand outward in a valve open state without creating a shelf or belly that would restrict flow.

What is claimed is: 
     
         1 . A low pressure gradient prosthetic heart valve, comprising:
 a support frame having a leaflet attachment edge with an undulating shape defined by alternating arcuate inflow cusp regions on an inflow end and arcuate outflow commissure regions on an outflow end, wherein the arcuate cusp regions have large radii of curvatures relative to the arcuate commissure regions so that the commissure regions commence at adjacent relatively straight sections leading up to a commissure tip, the commissure regions being cantilevered from the cusp regions such that the commissure tips flex in and out during use, the support frame circumscribing a flow volume having a central axis;   a plurality of flexible leaflets attached to the support frame and extending inward toward the axis, each leaflet having an arcuate cusp edge that conforms to a corresponding support frame cusp region and attaches therealong between adjacent commissure regions, and a free edge that coapts with the free edges of the other leaflets to provide one way flow through the valve, wherein the arcuate cusp edge of each leaflet is defined by a complex curve of multiple radii,   wherein when the valve opens the free edges of the leaflets move outward toward the flow volume described by the support frame from fluid flow in an outflow direction and corresponding fluid pressures.   
     
     
         2 . The heart valve of  claim 1 , wherein each leaflet is symmetric about a central midplane, and the complex curve of the cusp edge has a radius that is smallest on the central midplane, gradually increases on both sides away from the central plane, reaches a maximum radius at about 45° angle from the central axis, and then gradually decreases to two opposite ends. 
     
     
         3 . The heart valve of  claim 1 , wherein each commissure post of the support frame, in the relaxed state, is angled radially outward so as to provide an outflow orifice area greater than the maximum flow orifice area. 
     
     
         4 . The heart valve of  claim 3 , further including a suture-permeable sewing ring surrounding the cusp regions that provides a structural anchor to the surrounding anatomy at an inflow end of the support frame, wherein the commissure posts are cantilevered toward an outflow direction from the cusp regions when anchored to the surrounding anatomy such that the commissure tips may flex radially in and out from forces associated with fluid pressures on the flexible leaflets. cm  5 . The heart valve of  claim 1 , wherein the support frame comprises an elongated rod-like member made out of a continuous piece of Nitinol with no breaks or crimp. 
     
     
         6 . The heart valve of  claim 1 , wherein the free edge of each leaflet diverges above a straight line perpendicular to a central midplane that bisects the free edge and arcuate cusp edge, the free edge forming a supplemental strip of leaflet material that widens as it progresses inward toward the midplane. 
     
     
         7 . The heart valve of  claim 1 , wherein the support frame commissure regions each include an upstanding bar and a series of through holes therein, and each two adjacent leaflets are sutured to the through holes in an upstanding bar. 
     
     
         8 . A low pressure gradient prosthetic heart valve, comprising:
 a support frame having a leaflet attachment edge with an undulating shape defined by alternating arcuate inflow cusp regions on an inflow end and arcuate outflow commissure regions on an outflow end, wherein the arcuate cusp regions have large radii of curvatures relative to the arcuate commissure regions so that the commissure regions commence at adjacent relatively straight sections leading up to a commissure tip, the commissure regions being cantilevered from the cusp regions such that the commissure tips flex in and out during use, the support frame circumscribing a flow volume having a central axis;   a plurality of flexible leaflets attached to the support frame and extending inward toward the axis, each leaflet having an arcuate cusp edge that conforms to a corresponding support frame cusp region and attaches therealong between adjacent commissure regions, and a free edge that coapts with the free edges of the other leaflets to provide one way flow through the valve, each leaflet being symmetric about a central midplane that bisects the free edge and arcuate cusp edge, and wherein the free edge diverges above a straight line perpendicular to the central midplane to form a supplemental strip of leaflet material that widens as it progresses toward the midplane and has an apex on the vertical midplane,   wherein when the valve opens the free edges of the leaflets move outward toward the flow volume described by the support frame from fluid flow in an outflow direction and corresponding fluid pressures.   
     
     
         9 . The heart valve of  claim 8 , wherein each leaflet is symmetric about a central midplane, and the arcuate cusp edge of each leaflet is defined by a complex curve of multiple radii that is smallest on the central midplane, gradually increases on both sides away from the central plane, reaches a maximum radius at about  45 ° angle from the central axis, and then gradually decreases to two opposite ends. 
     
     
         10 . The heart valve of  claim 8 , wherein the supplemental strip of leaflet material forms a plateau for a majority of a length of the strip. 
     
     
         11 . The heart valve of  claim 8 , wherein each commissure post of the support frame, in the relaxed state, is angled radially outward so as to provide an outflow orifice area greater than the maximum flow orifice area. 
     
     
         12 . The heart valve of claim ii, further including a suture-permeable sewing ring surrounding the cusp regions that provides a structural anchor to the surrounding anatomy at an inflow end of the support frame, wherein the commissure posts are cantilevered toward an outflow direction from the cusp regions when anchored to the surrounding anatomy such that the commissure tips may flex radially in and out from forces associated with fluid pressures on the flexible leaflets. 
     
     
         13 . The heart valve of  claim 8 , wherein the support frame comprises an elongated rod-like member made out of a continuous piece of Nitinol with no breaks or crimp. 
     
     
         14 . The heart valve of  claim 8 , wherein the support frame commissure regions each include an upstanding bar and a series of through holes therein, and each two adjacent leaflets are sutured to the through holes in an upstanding bar. 
     
     
         15 . A low pressure gradient prosthetic heart valve, comprising:
 a support frame having a leaflet attachment edge with an undulating shape defined by alternating arcuate inflow cusp regions on an inflow end and arcuate outflow commissure regions on an outflow end, wherein the arcuate cusp regions have large radii of curvatures relative to the arcuate commissure regions so that the commissure regions commence at adjacent relatively straight sections leading up to commissure tips, the commissure regions being cantilevered from the cusp regions such that the commissure tips flex in and out during use, the support frame circumscribing a flow volume having a central axis, wherein the commissure regions each include an upstanding bar and a series of through holes therein;   a plurality of flexible leaflets attached to the support frame and extending inward toward the axis, each leaflet having an arcuate cusp edge that conforms to a corresponding support frame cusp region and attaches therealong between adjacent commissure regions, adjacent leaflets also being sutured to the through holes in an upstanding bar, each leaflet also having a free edge that coapts with the free edges of the other leaflets to provide one way flow through the valve,   wherein when the valve opens the free edges of the leaflets move outward toward the flow volume described by the support frame from fluid flow in an outflow direction and corresponding fluid pressures.   
     
     
         16 . The heart valve of  claim 15 , wherein each leaflet is symmetric about a central midplane, and the arcuate cusp edge of each leaflet is defined by a complex curve of multiple radii that is smallest on the central midplane, gradually increases on both sides away from the central plane, reaches a maximum radius at about 45° angle from the central axis, and then gradually decreases to two opposite ends. 
     
     
         17 . The heart valve of  claim 15 , wherein each commissure post of the support frame, in the relaxed state, is angled radially outward so as to provide an outflow orifice area greater than the maximum flow orifice area. 
     
     
         18 . The heart valve of  claim 17 , further including a suture-permeable sewing ring surrounding the cusp regions that provides a structural anchor to the surrounding anatomy at an inflow end of the support frame, wherein the commissure posts are cantilevered toward an outflow direction from the cusp regions when anchored to the surrounding anatomy such that the commissure tips may flex radially in and out from forces associated with fluid pressures on the flexible leaflets. 
     
     
         19 . The heart valve of  claim 15 , wherein the free edge of each leaflet diverges above a straight line perpendicular to a central midplane that bisects the free edge and arcuate cusp edge, the free edge forming a supplemental strip of leaflet material that widens as it progresses inward toward the midplane. 
     
     
         20 . The heart valve of  claim 15 , wherein the support frame comprises an elongated rod-like member made out of a continuous piece of Nitinol with no breaks or crimp.