Abstract:
A valve repair system, preferably including an annuloplasty prosthesis and a holder for the prosthesis. The holder includes a first component having a central opening, a circumferential surface and an outwardly extending member. The annuloplasty prosthesis is located adjacent to the circumferential surface, above the outwardly extending member. The holder further includes a second component movable upwardly relative to the first holder component and includes a rigid penetrating member extending downward from the second component into the prosthesis, holding it adjacent the circumferential surface. The holder also includes a suturing guide for assisting a physician in valve repair surgery, which may be a cuttable suture extending across the central opening along a path approximating a desired line of leaflet coaption. The cuttable suture may additionally secure the first and second components to one another. The suturing guide may also be incorporated into one-piece annuloplasty prosthesis holders or into stand-alone tools that do not carry annuloplasty prostheses.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    The present invention relates generally to surgical tools and more particularly for surgical tools used in conjunction with valve repair, including tools for holding prostheses such as annuloplasty rings and bands.  
           [0002]    Annuloplasty rings and bands are useful in a variety of surgical procedures, including mitral and tricuspid annular reduction. In these procedures, sutures are first placed around all or portions of the valve annulus at spaced intervals. Sutures passing through the annulus in regions in which reduction of the valve annulus is desired are spaced equidistant from one another, for example, at 4 mm intervals. These sutures are then brought through the annuloplasty ring or band more closely spaced than where they pass through the annulus, for example, 2 mm. The process of passing the sutures through the ring or band occurs while the prosthesis is held above the valve annulus. The ring is then moved down into contact with the valve annulus, causing contraction of the annulus, thus effecting a reduction in valve annulus circumference. This basic procedure is used to correct both mitral and tricuspid annular dilatation.  
           [0003]    In order for the sutures to be passed through the annuloplasty ring, it is desirable that the ring be held in a fixture or tool of some fashion. One early tool was manufactured by Pilling Instruments, and took the general form of a cone provided with a circumferential groove near the base. The cone was also provided with longitudinal slits, so that the tool could be contracted to accept the ring around the circumference of the groove. The tool was adapted to be held by means of a threaded handle.  
           [0004]    More recent holder designs are disclosed in U.S. Pat. No. 6,283,993, wherein sutures passing through the prosthesis are used to retain it in a circumferential groove on the holder. An alternative design is disclosed in U.S. Pat. No. 5,011,481, which employs radially and downwardly extending fingers in conjunction with sutures passing around the prosthesis to retain it on the holder. Yet another alternative design is disclosed in U.S. Pat. No. 5,522,884, in which an adjustable annuloplasty ring is retained on its holder by tightening the adjusting sutures within the ring to contract it into a circumferential groove on the holder.  
           [0005]    Examples of flexible annuloplasty bands and rings are also disclosed in the above cited patents, all of which are incorporated herein by reference in their entireties.  
         SUMMARY OF THE INVENTION  
         [0006]    The present invention is directed toward an improved holder for use with annuloplasty prostheses. The holder is specifically configured to assist the surgeon in performing the technique of mitral or tricuspid reduction, and is typically provided in conjunction with the annuloplasty ring or band, ready for use. The holder takes the general form of an oblate ring component having an upper surface, a lower surface, a central opening and an outer circumferential surface corresponding generally to the configuration of a valve annulus. The prosthesis extends around at least a portion of this circumferential surface and is releasably retained alongside this surface during the passing of sutures through the prosthesis.  
           [0007]    The present invention provides improvements directed to the mechanism for retaining the prosthesis on the holder during passage of the sutures and releasing the prosthesis after positioning on the valve annulus. Rather than retaining the annuloplasty ring to the holder by means of sutures passing through the annuloplasty ring, the ring is retained by means of downwardly extending penetrating members such as barbs, pins, pegs, or needles, which enter the annuloplasty prosthesis and retain it to the holder during passage of sutures through the prosthesis. These penetrating members may be fabricated of metal or molded plastic and are sufficiently rigid that they are not readily deflected outward to allow outward movement of the annuloplasty prosthesis away from the holder. The penetrating members may have sharpened or relatively blunt tips.  
           [0008]    The preferred embodiment is a two-component holder in which the first component includes the circumferential surface around which the prosthesis is mounted and the second component carries the penetrating members. The first component also typically includes radially extending projections that prevent the prosthesis from moving downward off of the penetrating members, until upward movement of the second component. In a preferred embodiment, the first and second holder components are retained to one another, for example by means of a suture or sutures coupling the first and second components together. In this embodiment, the first and second components become movable relative to one another following cutting of the suture or sutures retaining them together. The first and second holder components are preferably molded of generally rigid plastics but might in some cases be fabricated of metal or other materials.  
           [0009]    The present invention generally is intended to provide a simplified and more easily employed mechanism for holding the annuloplasty prosthesis during passage of the sutures through the prosthesis and for releasing it from the holder after the ring has been moved downward into its intended location on the valves annulus.  
           [0010]    The holder of the present invention is also provided with a mechanism for assisting the surgeon in the surgical repair of broken or elongated chordae tendinae (chords), as is sometimes performed in conjunction with placement of an annuloplasty prosthesis. This is accomplished by means of a suturing guide extending across the central opening through the holder, approximating the line of leaflet coaption. Sutures used to reconnect the inner edges of the valve leaflets to the papillary muscles are knotted around the suturing guide and the leaflet edge, to assure that the length of the suture is appropriate to allow leaflet coaption.  
           [0011]    The suture guide may be any elongated structure, such a rod, bar or cord, but in the preferred embodiment of the invention, the suture guide takes the form of a suture or sutures, extending across the opening through the holder. Cutting the suture allows it to be pulled through the knots at the leaflet edge, facilitating removal of the holder. In the disclosed embodiment, the suture or sutures extending across the central opening are extensions of sutures holding the first and second components closely adjacent one another, routed so that cutting the sutures to allow their removal from the knots at the leaflet edge also releases the first and second components so that the second component may move upward relative to the first component, allowing removal of the annuloplasty prosthesis from the holder.  
           [0012]    While in the preferred embodiments described below, the suture guide is part of a two-component annuloplasty prosthesis holder, the suturing guide may also be incorporated in a one-piece holder or in a stand-alone tool which does not carry an annuloplasty prosthesis. In such embodiments, the tool could include a single ring-shaped component corresponding generally to the annulus of the valve to be repaired and the suturing guide could extend across the central opening through the ring shaped component in a manner analogous to its location in the disclosed preferred embodiments. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    [0013]FIG. 1 illustrates a prior art annuloplasty prosthesis and holder, after passage of sutures through the annuloplasty prosthesis.  
         [0014]    [0014]FIG. 2 illustrates a cross section through a prior art annuloplasty prosthesis holder.  
         [0015]    [0015]FIG. 3 is a perspective view of a two-component annuloplasty prosthesis holder according and associated handle according to a preferred embodiment of the present invention.  
         [0016]    [0016]FIG. 4 is a perspective view from above of the embodiment of FIG. 3, with the handle removed.  
         [0017]    [0017]FIG. 5 is a perspective view from below of the embodiment of FIG. 3.  
         [0018]    [0018]FIG. 6 is a perspective view from below of the embodiment of FIG. 3, illustrating the second component moved upwardly from the first component to release the annuloplasty prosthesis.  
         [0019]    [0019]FIGS. 7A and 7B are a cross sectional views through portions of the first and second components of the embodiment of FIG. 3, illustrating interconnection of the prosthesis and the holder components.  
         [0020]    [0020]FIGS. 8A and 8B are cut-away views illustrating the use of the holder of FIG. 3 in conjunction with a surgical repair procedure.  
         [0021]    [0021]FIG. 9 is a perspective view of a second embodiment of two-component annuloplasty prosthesis holder according and associated handle according to a preferred embodiment of the present invention.  
         [0022]    [0022]FIG. 10 is a perspective view from below of the embodiment of FIG. 9.  
         [0023]    [0023]FIG. 11 is a perspective view from below of the embodiment of FIG. 9, illustrating the second component moved upwardly from the first component to release the annuloplasty prosthesis. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0024]    [0024]FIG. 1 is a perspective view of a two-piece annuloplasty holder according to the prior art. In particular, the holder system as illustrated is described in the brochure “Medtronic Duran Flexible Annuloplasty Systems In Service Guide”, published by Medtronic, Inc. in 2000, Publication No. UC200004685 EN, incorporated herein by reference in its entirety. The holder system includes a handle  16  which may be made of metal or plastic, and which may, in some embodiments, include a malleable shaft allowing for manual reconfiguration of the shaft. The shaft is snapped into the holder itself, which includes two components  10  and  12  that are molded of rigid plastic. The upper component  10  of the holder is transparent and serves as a template, including markings illustrating the locations of the valve trigones and regularly spaced markings assisting in placement of sutures around the annuloplasty prosthesis  13 . As illustrated, the first component  12  of the prosthesis releasably secured to the second component  10  of the prosthesis and the annuloplasty prosthesis  13  is mounted around a circumferential surface of the first holder component  12 .  
         [0025]    As illustrated, sutures  14  have been passed through the valve annulus  18  and upwardly and outwardly through the prosthesis  13  itself, according to conventional practice for implantation of annuloplasty prostheses. The holder system is then used to move the prosthesis  13  downwardly along the sutures so that it is seated adjacent to the upper surface of the annulus  18 . The second component  10  of the holder may be removed from the first component  12  by cutting the sutures holding them together, leaving the ring mounted around the first holder component  12 , seated adjacent the valve annulus. Although not visible in this view, the first component  12  of the holder includes a large central orifice, so that testing to assure that leaflets of the heart valve co-apt can be accomplished while the prosthesis  13  remains on the first component  12  of the holder. In the particular product marketed by Medtronic, Inc., removable of the prosthesis  13  from the first holder component  12  was accomplished by cutting sutures that held the prosthesis on the holder.  
         [0026]    [0026]FIG. 2 is a cross section through the first and second components of the holder illustrated in FIG. 1, in conjunction with attached annuloplasty prosthesis  13 . In this view it can be seen that the second component  10  of the holder is provided with a formed recess  15  configured to releasably engage a handle  16  (FIG. 1). In this view also it can be seen that the first holder component  12  defines a large central aperture illustrated generally at  17 , through which operation of the associated heart valve can be observed after removal of the second holder component  10 . As noted above, component  10  is held to component  12  by means of cuttable sutures, and prosthesis  13  is likewise maintained mounted to component  12  by means of cuttable sutures. Mounting of the prosthesis  12  to the first component  12  of the holder by means of these sutures requires handwork, increasing the expense and complexity of production of the system comprising the holder and the prosthesis. In addition, release of the prosthesis  13  from the first holder  12  requires multiple cuts of the sutures holding the prosthesis to the first holder component  12 , complicating the procedure for releasing the prosthesis from the holder.  
         [0027]    [0027]FIG. 3 is a perspective view of a second embodiment of a two-piece holder according to the present invention, with handle  209  attached. In this embodiment, annuloplasty prosthesis  204  is mounted against an outer circumferential surface of first holder component  202 , which is in turn retained against second holder component  200 . The second holder component  20  is provided with a snap fitting  210 , engaging a pin on the end of the handle  209 . The snap fitting may be replaced by a threaded recess or other mechanical mechanism for connecting to the handle  209 . Snap fitting  210  is mounted to a removable base  211 , which is retained to cross bar  208  of component  200  by means of suture  213 , which is captured to base  211 . Handle  209  and base  211  are removed together after cutting suture  213  at slot  215 . Sutures  206  retain component  200  adjacent component  202 . Sutures  206  are tied to component  200  in the vicinity of grooves  207  and  205 . When cut at grooves  207 , component  200  is released to move upward relative to component  202 , in turn releasing the annuloplasty prosthesis  204 , as described in more detail below.  
         [0028]    In this view it can seen that substantial apertures are defined through the assembly comprising components  200  and  202 , allowing for testing of the coaption of valve leaflets. The portions of sutures  206  extending across the apertures, between the edges of component  200  and cross bar  208  serve as a suturing guide to assist the physician in repair of leaflets with damaged chordae tendinae, as discussed in more detail in conjunction with FIGS. 8A and 8B.  
         [0029]    [0029]FIG. 4 is a perspective view from above of holder components  202  and  200  and prosthesis  204  as illustrated in FIG. 3 showing removal of the handle  209  and base  211  after cutting of suture  213 . While the preferred embodiment as illustrated employs a relatively small base  211  to which the handle is mounted, in alternative embodiments a template as discussed in conjunction with FIGS. 1 and 2, held to component  200  by cuttable sutures, might be substituted for base  211 . Alternatively, base  211  might be omitted and snap fitting  210  might instead be formed as part of the crossbar  208 . In yet other alternative embodiments some or all of crossbar  208  might be replaced with an additional suturing guide. In some such embodiments, the snap fitting  210  might be mounted adjacent to the inner periphery of component  200 .  
         [0030]    [0030]FIG. 5 is a view from below of the first and second holder components  202  and  200  in conjunction with the annuloplasty prosthesis  204 . Numbered elements correspond to those in FIG. 3. In this view, the routing of the sutures  206  to retain first and second holder components  202 ,  200  closely adjacent to one another is further illustrated. Sutures  206  are tied to component  202  adjacent its outer periphery by knots  201 , of which only one is visible. Free ends of sutures  206  then extend upward through component  200 , across slots  207  (FIG. 3), back downward through component  200 , along L-shaped slots  221  and across the apertures through component  202  to slot  229  in crossbar  208 . Sutures  206  then pass upward through crossbar  208 , along slot  205  (FIG. 7) back downward through crossbar  208  and are tied at knots  203  to retain them to the crossbar.  
         [0031]    In operation, the first and second components of the holder work as follows. When first and second holder components  202 ,  200  are located closely adjacent to one another as illustrated, pins  214  (not visible in this view) extending downward from component  200  extend through prosthesis  204 . Projections  220  extend radially outward from the first holder component  202  adjacent the lower surface of prosthesis  204  preventing downward movement of the prosthesis off of pins  214 . This mechanical interrelation is illustrated in more detail in FIGS. 10 and 11A, discussed below. When released, component  200  can move upwardly enough to withdraw the pins  214  from prosthesis  204 . Projections  220  are configured to allow them to bend inwardly after upward movement of component  200 , facilitating removal of the prosthesis  204 . This mechanism is also discussed in more detail in conjunction with FIGS. 6 and 7A. Holder components  200  and  202  are mechanically captured to one another by means of interacting tabs and grooves in regions  224  of the holder, described in more detail in conjunction with FIG. 7B.  
         [0032]    [0032]FIG. 6 is a view from below of the first and second holder components  202  and  200  in conjunction with the annuloplasty prosthesis  204 . Numbered elements correspond to those in FIGS.  3 - 5 . In this view, sutures  206  have been cut at slots  207 , allowing for holder component  200  to be moved slightly upwardly from holder component  202 . Holder component  200  has moved upwardly enough to withdraw pins  214  from prosthesis  204 . The prosthesis  204  is removed over projections  220 , leaving it positioned adjacent to valve annulus. In this view, it can be seen that pins  214  extend through openings or interruptions  223  in the circumferential flange  226  located adjacent the upper edge of component  202 . As illustrated in more detail in FIG. 7A, projections  220  can pivot inwardly, facilitating removal of the prosthesis  204  from the holder after circumferential wall  228  of component  200  has moved upward of the projections  220  and no longer prevents their inward motion.  
         [0033]    In the specific embodiment illustrated, pins  214  extend all the way through the prosthesis  204  and into corresponding holes  221  in the lower, radially extending projections  220 . In other embodiments, pins  214  may be shortened and need not extend all the way to or into the lower radially extending projections  220 . As discussed above, extension of the pins  214  to or preferably into the projections  120  may be especially desirable if the annuloplasty prosthesis  204  is very flexible and or extensible and may be less beneficial if the annuloplasty prosthesis  204  is a generally rigid or inextensible prosthesis. While the prosthesis  204  as illustrated takes the form of an annuloplasty ring, the holder may also be used with a band. In such case, the pins  214  are preferably located so that they will pass through the band adjacent its ends.  
         [0034]    [0034]FIG. 7A illustrates a cross-sectional view through a portion of the combination of first holder component  200 , second holder component  202  and the prosthesis  204 . In this view, illustrating the situation prior to upward movement of the second holder component. Pin  214  passes through the aperture  223  in the outwardly extending flange  226  (FIG. 6) of upper component  220 , extends through prosthesis  204  and terminates in hole  221  in projection  220 . Outwardly extending projection  220  prevents downward movement of the prosthesis  204  off of pin  214 . Preferably, the thickness of first component  200  is reduced at  219  to define a hinge point, allowing projection  220  to pivot inward after upward movement of circumferential wall  228  has occurred.  
         [0035]    [0035]FIG. 7B illustrates a cross-sectional view of a portion of the assembly comprising first and second holder components  202 ,  200  and prosthesis  204 . This cross-section is taken through one of the regions  224  illustrated in FIGS. 5 and 6. Holder components  200  and  202  are retained to one another by projections or tabs  213  located slidably within grooves  215 , allowing upward movement of second component  200  until the lower end of  217  of groove  215  contacts the projection  213 . This mechanism limits upward movement of the second holder component  200  and retains first and second holder components  200 ,  202  together, as illustrated in FIG. 6.  
         [0036]    [0036]FIGS. 8A and 8B are cut-away views illustrating the utility of sutures  206  in conjunction with surgical repair of broken or elongated chordae tendinae (chords), as is sometimes performed in conjunction with placement of an annuloplasty prosthesis. The basic procedure involved is described in the article “Surgical Techniques For The Repair Of Anterior-Mitral Leaflet Prolapse” by Duran, published in the Journal Of Cardiovascular Surgery, 1999; 14:471-481, incorporated herein by reference in its entirety. As illustrated in FIG. 8A, a double-armed suture  252  is first attached to the papillary muscle  256  by means of a pledget  258 . Alternatively, as described in the Duran article, if multiple chords are to be replaced, a loop of suture may be attached to the papillary muscle and multiple double-armed sutures passed through the loop for attachment to the valve leaflet or leaflets. Suture  252  is intended to replace the broken chord  255 . The free ends of the suture  252  are passed upward and sutured to the edge of valve leaflet  250 , previously attached to the papillary muscle  256  by means of the broken chord.  
         [0037]    In the procedure as described in the above cited Duran article, adjustment of the height of the leaflet  250  to determine proper placement of knots  254 , coupling the sutures  252  to the leaflet  250  was accomplished by means of an additional suture passed through the leaflet, held upward by means of forceps to adjust the appropriate leaflet height. In conjunction with the present invention, after the annuloplasty prosthesis  204  has been moved downward and sutured to the valve annulus, suture  206  is used as a suturing guide for determining the proper point at which knots  254  are tied, to assure that the leaflet  250  will coapt properly with the adjacent leaflet  251 . Knots  254  comprise a series of knots, the first of which is tied around suture  206 . The remaining knots are tied thereafter. One or more repairs of this type may be made along the portions of suture  206  extending across the apertures through the annuloplasty prosthesis holder, depending upon the number of chords that are broken. In the embodiment as illustrated in FIGS.  3 - 5  above, the path of the sutures  206  as they cross the apertures through the annuloplasty holder is intended to generally approximate the line of coaption of the leaflets of a mitral valve, facilitating their use in this particular surgery. Other possible routings for the sutures  206  might be substituted in conjunction with other possible valve repair surgeries.  
         [0038]    [0038]FIG. 8B illustrates the production of knots  254  to anchor sutures  252  to the valve leaflet  250  in more detail. In this view it can be seen that one of the free ends of the suture  252  is passed upward through the valve leaflet, around the edge of the valve leaflet and through the leaflet again, while the other free end is simply passed up through the valve leaflet. The free ends are knotted together around suture  206  and the series of knots is continued until an adequate number of knots are provided to safely anchor the suture  252  to the valve leaflet  250 .  
         [0039]    After the leaflet repair is complete, sutures  206  are cut at slots  207  (FIG. 3) as discussed above to allow annuloplasty holder component  200  to move upward relative to component  202  (FIG. 6) to release the prosthesis  204 . This also allows the cut ends of the sutures  206  to be pulled through the knot or knots  254 , as the holder assembly is moved upward away from the valve annulus. While sutures  206 , provide a preferred mechanism for facilitating the repair procedure discussed above, it is possible that other structures could be substituted for them, including other types of tensile members or more rigid members such as rods or bars, provided that provision is made for removal of the structures from the knots  254 , after the surgical repair is complete.  
         [0040]    [0040]FIG. 9 is a perspective view of an alternative embodiment of the present invention which operates in the same general manner as the embodiment illustrated in FIGS.  3 - 8 B, described above. The embodiment of FIG. 9 does include some differences in structure and function, which are discussed in more detail below.  
         [0041]    The handle  209 A is somewhat modified from the handle illustrated in FIG. 3, in that the lower end of the handle is provided with two inwardly deflectable arms  209 B, each carrying an outwardly extending projection at their lower end, engaging in corresponding apertures  210 B in snap fitting  210 A. Base member  211 A otherwise corresponds generally to base member  211  discussed above, and is secured to holder component  200 A by means of suture  215 A in the same fashion as described in conjunction with base member  211  described above.  
         [0042]    The suturing guide  206 A takes the form of a cuttable suture, routed in a manner analogous to that of the above-described embodiment. However, cutting guides  207 A are formed as grooves in the upper surface of component  200 A rather than penetrating through the component. Further, two additional retention sutures  206 B are provided, which operate to retain component  200 A to component  202 A, in addition to the retention function performed by the sutures  206 A. Sutures  206 B are also associated with cutting guides  207 A, which take the form of slots formed in the upper surface of component  200 A. Cutting of the sutures  206 A and  206 B at all four of the cutting guides  207 A is required in order for component  202 A to be moved downward relative to component  200 A to release the prosthesis  204 A, in a manner analogous to that described in conjunction with the embodiment discussed above.  
         [0043]    [0043]FIG. 10 is a perspective view from the lower surface of the embodiment of FIG. 9. All numbered components correspond to identically numbered components illustrated in FIG. 9, discussed above.  
         [0044]    [0044]FIG. 11 is a perspective view from below the embodiment of FIG. 9 with component  202 A moved downward relative to component  200  to release prosthesis  204 B. In order for component  200 A to move downward relative to component  200 A, all of the sutures  206 A and  206 B must be cut at cutting guides  207 A (FIG. 9).  
         [0045]    In this view, the routing of sutures  206 A and  206 B is more clearly illustrated. Sutures  206 A are anchored to component  202 A by passing them through two adjacent holes in component  202 A and knotting the sutures at  201 A to retain them to component  202 A. One end of each suture  206 A is then passed upward through adjacent holes the components  202 A and  200 A, extended across a cutting guide  207 A (FIG. 9), passed downward through adjacent holes in components  200 A and  202 A on the other side of cutting guide  207 A and passed through slot  221 A. The sutures  206 A are then extended across the aperture through component  202 A, where they are anchored to crossbar  208 A by means of knot  203 A in a manner identical to that described in conjunction with the embodiment of FIGS.  3 - 8 B. Sutures  206 B are first anchored to component  202 A by being looped through adjacent holes through component  202 A and knotted at  201 B. One free end of each suture  206 B is then passed upward through adjacent holes in components  202 A and  200 A, extended across a cutting guide  207 A (FIG. 9), passed downward through adjacent holes in components  200 A and  202 A on the other side of cutting guide  207 A and knotted at  201 C to retain components  200 A and  202 A adjacent to one another. As illustrated, the free ends of the suture  206 B are shown after cutting to allow downward movement of component  202 A relative to component  200 A.  
         [0046]    In this view it can also be seen that the needles  214 A, rather than being provided with sharp tips as in the embodiment of FIGS.  3 - 8  described above, are provided with rounded or ball-tip ends. The needles  214 A pass through prosthesis  204 A and operate to retain the prosthesis to the holder in the same manner as described above in conjunction with the embodiment of FIGS.  3 - 8 B.