Abstract:
An annuloplasty prosthesis for a heart valve has a sewing cuff added to the conventional structure. The sewing cuff is preferably an extension of the fabric cover that is provided around the core of the prosthesis. The sewing cuff preferably extends radially outwardly from cross sections of the remainder of the prosthesis. Methods of making such a sewing cuff are also disclosed.

Description:
[0001]     This application claims the benefit of U.S. provisional patent application No. 60/571,437, filed May 14, 2004, which is hereby incorporated by reference herein in its entirety. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     Annuloplasty prostheses for heart valves are well known as is shown, for example, by Alfieri et al. U.S. patent application publication US 2002/0173844 Al and Bolling et al. U.S. patent application publication US 2003/0093148 Al. Such prostheses may be complete rings (e.g., as in the above-mentioned Alfieri et al. and Bolling et al. references), or they may be less than complete rings (e.g., as in Carpentier U.S. patent 3,656,185). The term “annuloplasty” is used herein to refer to both of these types of prostheses (i.e., both complete rings and less than completely annular structures (e.g., generally C-shaped structures)).  
         [0003]     Typical annuloplasty prostheses include a core member surrounded by a soft fabric cover. The core member is often substantially rigid or at least semi-rigid and not penetrable by a suture needle and suture material. The fabric cover may be designed to cushion the prosthesis, and possibly also to promote tissue in-growth into the prosthesis to help integrate the prosthesis into the patient&#39;s body. It is often desired to secure the prosthesis in the patient by passing one or more suture needles and suture material through the fabric cover and adjacent tissue. Tightness and/or thinness of the fabric cover may make this difficult to do. Even if the surgeon is successful in getting proper engagement, the amount of fabric caught may be less than would be desirable for good tissue healing and over-growth.  
       SUMMARY OF THE INVENTION  
       [0004]     To facilitate suturing an annuloplasty prosthesis into a patient, a sewing cuff is added to the prosthesis in accordance with the invention. Such a sewing cuff is preferably an extension of the fabric cover that is provided around the core of the prosthesis. The sewing cuff preferably extends radially outwardly from cross sections of the core and the remainder of the fabric cover. Stitching may be used to stabilize the extension. The extension may be one-piece with the fabric cover. For example, a medial portion of the cover fabric may be used to form the extension. As another example, a free edge portion of the fabric used for the cover may be used to provide the extension. The free edge portion may be folded to increase the bulk of the extension. Two free edge portions of the fabric used for the cover may be used together to form the extension. Again, folding may be used to increase the bulk of the extension.  
         [0005]     The invention also includes various methods of making sewing cuffs such as those summarized in the preceding paragraph.  
         [0006]     Further features of the invention, its nature and various advantages, will be more apparent from the accompanying drawings and the following detailed description of the preferred embodiments. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]      FIG. 1  is a simplified cross sectional view of an illustrative embodiment of an annuloplasty prosthesis for a heart valve in accordance with the invention.  FIG. 1  may be taken as shown at  1 - 1  in  FIG. 7 .  
         [0008]      FIG. 2   a  is a simplified cross sectional view of an illustrative embodiment of a component that can be used in making a prosthesis like that shown in  FIG. 1  in accordance with the invention.  
         [0009]      FIG. 2   b  is similar to  FIG. 2   a,  but shows a later stage in handling the component in accordance with the invention.  
         [0010]      FIG. 2   c  is again similar to  FIGS. 2   a  and  2   b,  but shows a still later stage in accordance with the invention.  
         [0011]      FIG. 2   d  is generally similar to  FIG. 1 , but shows an end result from the progression of  FIGS. 2   a - 2   c  in accordance with the invention.  
         [0012]      FIGS. 3   a - 3   c  are each generally similar to  FIG. 1 , but show a progression in an alternative approach to making a prosthesis in accordance with the invention.  
         [0013]      FIG. 4  is again generally similar to  FIG. 1 , but shows an alternative construction of a prosthesis in accordance with the invention.  
         [0014]      FIG. 5  is once again generally similar to  FIG. 1 , but shows another alternative construction of a prosthesis in accordance with the invention.  
         [0015]      FIG. 6  is again generally similar to  FIG. 1 , but shows still another alternative construction of a prosthesis in accordance with the invention.  
         [0016]      FIG. 7  is a simplified plan view of an illustrative embodiment of a prosthesis in accordance with the invention. 
     
    
     DETAILED DESCRIPTION  
       [0017]     The annuloplasty prosthesis  10  cross section shown in  FIG. 1  includes core member  20 , a layer  30  of an elastomeric material surrounding core  20 , and fabric cover  40  surrounding elements  20  and  30 .  FIG. 1  also shows what may be described as a mini-sewing-cuff  50  extending radially outwardly from the other elements at one angular location or region around the circumference of the cross section. For completeness  FIG. 7  shows a plan view of an entire illustrative annuloplasty prosthesis  10  in accordance with the invention and which can have a cross section as shown in  FIG. 1  (or as in other FIGS. subsequent to  FIG. 1 ). Although  FIG. 7  shows the cross section taken at one particular location, substantially the same cross section may be found at other (or even all) locations annularly around prosthesis  10 . Also, although  FIG. 7  shows a prosthesis  10  that is a complete, unbroken, generally D-shaped annulus, prosthesis  10  could have other shapes, and could alternatively be only a portion of an annulus (e.g., it could be C-shaped rather than D-shaped). Still another point to be made is that although  FIG. 7  shows sewing cuff  50  extending around the outside of prosthesis  10 , sewing cuff  50  could alternatively be at any other location around cross sections of the prosthesis.  
         [0018]      FIG. 7  is provided to make the point that, although most of the other FIGS. herein are of cross sections, these other FIGS. are representative cross sections of structures that extend longitudinally (e.g., out of the plane of the paper on which the cross sections are drawn).  
         [0019]     Typical materials for the various components of prosthesis  10  will be mentioned later in this specification. For the moment it will be sufficient to point out that elastomeric layer  30  is optional and may be omitted in some embodiments of the invention. Fabric cover  40  would then be directly over core  20 . The FIGS. subsequent to  FIG. 1  show generalized cores  20 , which can be either like core  20  in  FIG. 1  or a composite of elements such as  20  and  30  in  FIG. 1 .  
         [0020]     Sewing cuff  50  can be formed on prosthesis  10  in any of a number of different ways. Some examples are shown in subsequent FIGS. and described below.  
         [0021]     In the illustrative embodiment shown in  FIGS. 2   a - 2   d,  a medial (or more generally an interior) portion of fabric  40  is gradually pinched together as shown progressively in  FIGS. 2   a - 2   c  until two interior creases  42   a  and  42   b  are formed and brought together ( FIG. 2   c ). A fine suture  60  is then used to sew the two creases  42  together to create sewing cuff  50 . After the sewing cuff has been sewn together, the two free ends (edges)  44   a  and  44   b  of fabric  40  are wrapped around prosthesis core  20  and stitched together as shown at  70  in  FIG. 2   d.  Fabric  40  is pulled tightly together during stitching  70  so that it will securely and firmly wrap around prosthesis core  20 .  
         [0022]     In the alternative embodiment illustrated by  FIGS. 3   a - 3   c,  fabric cover  40  is first wrapped loosely around prosthesis core  20 . A portion of the fabric annulus is gradually squeezed or pinched together as shown at  41  in  FIG. 3   b.  This eventually produces a sewing cuff. Depending on the width of the cuff required, the amount of fabric  40  squeezed or pinched together to create the cuff can vary. Suture  60  is added to hold sewing cuff  50  together as shown in  FIG. 3   c  to complete the process.  
         [0023]     In the further alternative embodiment shown in  FIG. 4 , sewing cuff  50  is created by squeezing together two otherwise free edges  46   a  and  46   b  of fabric  40  after the fabric has been wrapped around prosthesis core  20 . A fine suture  60  can then be used to stitch the two single-layers fabric edges together (and around core  20 ) to form the sewing cuff. The width (radial outward projection) of the cuff (dimension W in  FIG. 1 ) can be determined by adjusting the amount of excess fabric  40  used to wrap around the core. More than just the single stitch line  60  can be used to hold edges  46   a  and  46   b  together in sewing cuff  50 .  
         [0024]     In the still further alternative embodiment shown in  FIG. 5 , fabric  40  is loosely wrapped around prosthesis core  20  with both edges  48   a  and  48   b  free. Free edges  48  are then folded over on themselves so that each free edge becomes double-layered. The two double-layered free edges are then squeezed together, and a fine suture  60  is used to stitch the fabric together to form sewing cuff  50 . A sewing cuff created in this way can be thicker (bulkier) and provide more cushioning. Free edges  48  can also be folded over multiple times to create a triple- or other multiple-layered cuff  50 .  
         [0025]     In the further illustrative embodiment shown in  FIG. 6 , sewing cuff  50  is first formed by folding a free edge portion of fabric  40  several times as shown at  49  to get the thickness desired. This is then stitched together with suture  60  so that the sewing cuff is stabilized and remains intact with the desired shape. The remaining free edge of fabric  40  is used to wrap around prosthesis core  20  and then stitched to the sewing cuff as shown at  70 . Fabric  40  will wrap around ring core  20  securely and firmly when the process is completed.  
         [0026]     Sewing cuff  50  may measure from about 0.25 mm to about 5.0 mm in width (see dimension W in  FIG. 1  or the comparable unreferenced dimension in any of the other FIGS.). The sewing cuff may be created from a soft fabric such as polyester, PTFE, or the like, and may be the same as (or even one piece with) fabric cover  40 . Sewing cuff  50  allows the surgeon to place sutures easily, and also provides substantially more fabric for tissue in-growth purposes. More sewing fabric also allows for a better cushion between the heart valve annulus and the prosthesis. As has been said, sewing cuff  50  can also be used with a prosthesis core that is first covered by a soft elastomer  30 , such as silicone or the like, before it is covered by a fabric  40  with cuff  50 . The sewing cuff can also be used on just prosthesis core  20  itself without any intermediate elastomer covering  30 . Prosthesis core  20  can be made from any suitable material, such as stainless steel, titanium, ceramic, elgiloy, shape-memory alloy, and/or polymeric material.  
         [0027]     It will be understood that the foregoing is only illustrative of the principles of the invention, and that various modifications can be made by those skilled in the art without departing from the scope and spirit of the invention. For example, although the FIGS. herein show prostheses having cores  20  that are round in cross section, it will be appreciated that other core cross sectional shapes can be used instead if desired.