Prosthetic Heart Valve Having Fabric Suturing Element

Abstract

A prosthetic heart valve is disclosed having a support ring which carries means for retaining a movable closure element in positions adjacent one side of the ring. The support ring has a fabric wrapping which defines, as a suturing element, an annular protrusion of fabric of double thickness extending from the side of the ring which is opposite the side adjacent the closure element.

Description

BACKGROUND OF THE INVENTION

While a large variety of prosthetic heart valves have been experimentally used, and a number of types are commercially available, there still remain problems which have yet to be solved to the complete satisfaction of the surgeon. First, while it is desirable for heart valves to be generally circular in shape to permit the closure element to rotate during use in order to minimize uneven wear, the site within the heart to which the valve is affixed is frequently oval in shape. Hence, the tissue at the site to which the valve is affixed must be forced to assume the circular shape of the valve by suturing. This creates stress upon the tissue, which is, of course, undesirable.

Additionally, partly because of the stress on the tissue, and in order to minimize the possibility of leakage about the valve, the sutures are typically emplaced by an interrupted technique for maximum reliability. Such a technique is time consuming and inconvenient.

The valve of this invention carries on one side thereof a suturing cuff which is of adjustable shape to fit the natural contour of the suturing site within the heart. Furthermore, because of the unique manner in which the prosthetic valve of this invention can be emplaced in the heart, with the valve rim being spaced from the suture site, the suturing cuff provides an added sealing function which greatly reduces the possibility of blood leakage about the prosthesis. This permits the use of more desirable continuous suturing techniques.

While it has been taught (e.g., Annals of Thoracic Surgery, Vol. 8, No. 8, (1969), p. 133-145) to use a single layer skirt to overlie the suture line which affixes the valve in place, the advantages described above are not achieved by this latter technique as effectively as in the present invention.

DESCRIPTION OF THE INVENTION

In accordance with this invention, a prosthetic heart valve is provided having a support ring which carries means for retaining a movable closure element adjacent one side of the ring. The ring has a fabric wrapping which defines, as a suturing element, an annular protrusion of fabric of double thickness extending from the side of the ring opposite the side mentioned above adjacent the closure element. The fabric wrapping is typically a folded and sewn tubular sleeve in which the annular fabric protrusion is maintained in double thickness configuration by a sewn seam. Typically, the fabric used is a velour material made from polyester fiber or the like.

In the drawings,

FIG. 1 is an elevational view of a prosthetic heart valve with portions partly broken away, and shown in section, the sectional portion corresponding to the view along line 1--1 of FIG. 2.

FIG. 2 is a bottom plan view of the same prosthetic heart valve with portions partially broken away and shown in section.

FIG. 3 is a partial sectional view of a portion of the prosthetic heart valve of this invention shown in an intermediate stage of assembly.

FIG. 4 is a partial sectional view of the same portion of the heart valve in a further stage of assembly.

FIG. 5 is a partial sectional view of the same portion of the valve in completed form.

FIG. 6 is a detailed view, partially in section, of a portion of a strut encased in a portion of the support ring.

FIG. 7 is an elevational view, with a portion broken away and sectioned, of the support ring prior to assembly.

FIG. 8 is a diagramatic view of a prosthetic heart valve of this invention sutured in position in a heart.

Referring to FIGS. 1 and 2, a mitral valve is shown which utilizes the invention of this application. The valve has a support ring 10 having a cross-sectional shape as illustrated in FIG. 1. Support ring 10 serves to define the shape of the body of the heart valve and the central opening 11 defined therein, and is a support for its cloth covering and for the means for retaining a movable closure element described below. If desired, support ring 10 can be oval in shape to more closely accommodate the natural shape of the suturing site.

Ring 10 carries a pair of struts 12, which struts retain a movable closure disc 14, which is typically made of pyrolytic carbon. Disc 14 is movable between an open, flow-permitting position as shown in full lines of FIG. 1, and a closed, flow-occluding position as shown in dotted lines in the same Figure.

Ring 10 has a toroidal fabric wrapping 16 which defines, as a suturing element, an annular protrusion 18 of fabric of double thickness extending from the side ring 10 opposite the side adjacent the closure disc 14. Double thickness suturing element 18 is used to suture the valve in position within the mitral orifice as shown in FIG. 8, with the resultant advantages described above. The double thickness of suturing element 18 provides added strength and sealing capability, to avoid blood leakage about the valve. The body of the valve, including ring 10, struts 12, and disc 14, typically hang below the heart's mitral ring in the ventricle, as shown in FIG. 8. If desired, a continuous suture technique can be used to affix suturing element 18 to the mitral ring, with the suturing element 18 being generally deformed outwardly as shown, to provide a better seal against blood leakage. With each pulse of blood pressure, suturing element 18 is pressed outwardly against the mitral ring for additional sealing capability.

Each strut 12 contains an internal rod 20 (FIG. 6), typically of titanium, which can be enclosed in a sheath 22 which is made of hard, nonthrombogenic plastic such as polytetrafluoroethylene. Strut 12 comprises a disc-holding portion 24 outside of ring 10, and a pair of retained portions 26 which fit within a channel 21 defined in ring 10 for securance to the ring. An outer, annular flange 28 of ring 10 is bent inwardly to secure each of the retained portions 26 of strut 12 in place.

Since the annular channel 21 (FIG. 3) defined in ring 10 is not completely filled after emplacement of the strut 12, an additional pair of curved filler rods 30 are supplied to fill the remaining space of the channel 21.

Retained portions 26 of the struts and curved filler rods 30 are held together in a subassembly by means of support ring 32, which is initially of U-shaped cross section, as shown in FIG. 7. Support ring 32 has slots 34 defining tabs 35, which can be folded over retained portions 26 and curved filler rods 30. Appropriate cutaway portions of support ring 32 and flange 28 are provided to permit the struts 12 to pass out of the ring at the points where disc-holding portions 24 are defined.

Ring 10 carries an annular seat 36 against which closure disc strikes and seals when in the closed, flow-occluding position. Seat 36 includes a circular strip of flexible adhesive 38 (FIG. 3) which is typically silicone rubber. Adhesive 38, in turn, holds a circular strip 40 of dacron felt or the like, to provide a relatively resilient seat over which fabric 16 passes and against which disc 14 strikes as it closes.

Referring to FIGS. 3 through 5, a technique for assembling the valve of this invention is shown.

A tubular piece of dacron velour or the like is sewn together along a circular seam 42 to define suturing element 18. The sewn tubular fabric material 16 is then placed over support ring 10 in the manner indicated in FIG. 3, and ends 44, 46 are sutured together with a second circular seam 48 and pushed upwardly into channel 21 defined in ring 10 as indicated in FIG. 4. The dimensions of tubular fabric 16 are so selected that a firm fit of fabric is achieved about ring 10. Following this, the subassembly made of struts 12, curved filler rods 30, support ring 32, and disc 14 is also inserted into channel 21 defined in ring 10. Fingers 50 of flange 28, which are separated by channels 52, are pushed inwardly toward the center of ring 10 to affix the subassembly held together by support ring 32 in ring 10. Prior to insertion of the subassembly including support ring 32 into channel 21, disc 14 has been incorporated into the subassembly, so that bending of fingers 50, as indicated in FIG. 5, results in the completed heart valve as shown in FIGS. 1 and 2.

The above disclosure has been for illustrative purposes only and is not intended for purposes of restriction of the invention, which is defined in the claims below. While a single type of heart valve has been disclosed herein, the invention of this application is contemplated for use with any of a large variety of valves for use in the heart or for other uses, including all types of aortic as well as mitral valves. Some specific types of valves in which the invention of this application can be used include other discoid valves, such as those with struts which cross each other to define a cage-like enclosure about the movable disc, valves using movable occluder balls, or valves with poppet occluders connected to a projecting neck and slidably held in a retention ring, such as the valve shown in issue of The Lancet published Sept. 24, 1962, page 1087.

Tilting disc valves such as those shown in U.S. Pat. No. 3,476,143, can also be built in accordance with this invention. Likewise, different fabric wrappings and other configurations can be used in valves made in accordance with this invention, such as in the valves described in U.S. Pat. Nos. 3,099,016 and 3,263,239.

Claims

That which is claimed is:

1. A prosthetic heart valve which comprises: a support ring defining an orifice, which support ring carries means retaining a moveable closure element adjacent one side of said support ring, said support ring having a fabric wrapping which defines, as a suturing element, a flexible annular protrusion. of fabric of multiple thickness extending solely from a radially inward portion of the side of the support ring in position adjacent the orifice, and positioned opposite said one side adjacent the closure element, said protrusion extending in a direction approximately perpendicular to the plane of said support ring, and an annular seam securing together the thickness of fabric defining said annular protrusion.

2. The heart valve of claim 1 in which said fabric wrapping is a folded and sewn tubular sleeve.

3. The heart valve of claim 2 in which the annular fabric protrusion is of double thickness.

4. The heart valve of claim 3 in which said fabric is velour which comprises polyester fiber.

5. The heart valve of claim 4 in which said movable closure element is a disc which is movable between an open, flow-permitting position and a closed, flow-occluding position.

6. A prosthetic heart valve which comprises a support ring defining an orifice, which support ring carries means retaining a moveable closure element adjacent one side of said support ring, said support ring having a fabric wrapping which defines, as a suturing element, a flexible annular protrusion of fabric of multiple thickness extending solely from a radially inward portion of the side of the support ring in a position adjacent the orifice, and positioned opposite said one side adjacent the closure element, said protrusion extending in a direction approximately perpendicular to the plane of said support ring and having inner and outer ends, an annular seam securing the thickness of fabric defining said annular protrusion of fabric together adjacent said inner end, and sutures in the outer end of said protrusion for securance to a mitral orifice of a heart, the outer periphery of said support ring being free of tissue-securing sutures.