Heart valve leaflet with reinforced free margin

#The disclosures herein relate generally to heart valves and more particularly to tri-leaflet polymer valves.

#Heart valves include mechanical valves, tissue valves and polymer valves. A heart valve is implanted into an annular opening in a heart created when a diseased valve is removed. The valve can be secured in the annulus of the opening through the use of sutures or pins that penetrate the host tissue and an outside edge of the valve. Alternatively the valve can then be secured in the annulus by suturing the host tissue to the sewing ring. Heart valves function essentially as a one-way check valve.

#Early heart valve prostheses included ball-and-cage valves and disc-and-cage valves in which a ball or a disc was housed in a cage. One side of the cage provided an orifice through which blood flowed either into or out of the heart, depending on the valve being replaced. When blood flowed in a forward direction, the energy of the blood flow forced the ball or disc to the back of the cage allowing blood to flow through the valve. When blood attempted to flow in a reverse direction, or “regurgitate”, the energy of the blood flow forced the ball or disc into the orifice in the valve and blocked the flow of blood.

#FIG. 1 is an isometric view illustrating an embodiment of a heart valve having leaflets in a natural state.

#FIG. 2 is a top view illustrating an embodiment of the heart valve having leaflets in the natural state.

#FIG. 3 is an isometric view illustrating an embodiment of the heart valve having leaflets in the open position.

#A heart valve is generally designated 10 in FIGS. 1 and 2. Heart valve 10 is formed as a one-piece molded biocompatible polymer body such as silicone or polyurethane and includes a generally annular peripheral body portion 12 which has a base 14. A sewing ring 16 may be formed with the base 14. Three flexible leaflets 18 are formed with body 12 and extend from an attachment curve 20 to terminate at a free margin 22 which is not in contact with another portion of body 12 when the valve is in a natural-state condition, i.e. the valve parts are at rest and are not under the influence of any pressure acting thereon. This is in contrast with the valve after installation when the pumping action of the heart sequentially and repeatedly opens and closes the valve by urging the leaflets in a first or opening direction indicated by the arrow designated FD, and then in a second or closing direction, opposite the first direction, indicated by the arrow designated SD.

#The entire heart valve 10 is molded including a gap 24 which is preferably formed between each free margin 22. This is preferred over cutting to separate the valve leaflets after molding to form the free margins and improves the durability of the valve 10.

#The attachment curve 20 defines a coupling between each leaflet 18 and the peripheral body portion 12, and also defines three shaped posts 26 which comprise an extension of body 12 terminating at a commissure 28 where gap 24 ends. This corresponds to the location where each leaflet 18 comes together with an adjacent leaflet. Posts 26 and each commissure 28 are at a height H above base 14.