Patent Abstract:
A suture passing mechanism is disclosed having an elongated delivery member and a suture capture fitting at a distal end of the delivery member. The suture capture fitting includes a recess for receiving a length of suture. The recess is bounded by a proximal wall and a lateral opening leads therein. An expeller at the recess is adapted to expel suture out of the recess through the lateral opening.

Full Description:
BACKGROUND 
     The present invention relates to suture passers and graspers and more particularly to such instruments and methods for their use wherein provision is made to eject the suture therefrom. 
     Within the field of medical surgery, there are times when a suture needs to be passed through soft tissue, but direct access to the tissue is not possible (e.g. during arthroscopy). Generally, this passage of suture is performed either anterograde or retrograde. In anterograde passing an instrument called a suture passer grasps a strand of suture and is forcibly driven through the soft tissue. Then, the suture is disengaged from the passer and the passer removed from the tissue. Retrograde passing involves driving an empty passer through the soft tissue and then manipulating it such that it captures a length of suture already inside the body. The passer is then removed from the soft tissue and pulls the suture through with it. In both of these cases, one major drawback of the suture passer is that it can be quite difficult to disengage the suture from the jaws of the passer. This is particularly true for the anterograde technique and is mainly due to the fact that the passer jaws open into a fairly large cavity. The surgeon must manipulate the tip of the passer to cause the suture to move sufficiently out of the open jaws that closing the open jaws will no longer cause the suture to become re-trapped by the passer. This process of manipulation can lead to trauma to the surrounding soft tissue up to and including the suture passer ripping through the soft tissue, foiling the repair intent of the suturing and forcing the surgeon to pursue alternate courses of repair of patient treatment. The cavity frequently also is provided with a lip or other structure to assist in the process of capturing the suture, but such features can add difficulty when the surgeon later attempts to expel the suture. 
     SUMMARY OF THE INVENTION 
     A suture passing mechanism according to the present invention comprises an elongated delivery member having a suture capture fitting at a distal end thereof. The suture capture fitting comprises a recess for receiving a length of suture. The recess has a proximal wall and a lateral opening leading therein. An expeller at the recess is adapted to expel suture out of the recess through the lateral opening. 
     Preferably, the expeller comprises a surface movable across the recess toward the lateral opening whereby to push the suture out of the lateral opening. In one embodiment, the expeller comprises a line affixed adjacent the lateral opening. It is received within the recess and spaced apart from the opening in a first position and adjacent the lateral opening in a second position. In one aspect of the invention, the line is biased into the first position and tension applied to the line moves it into the second position. Alternatively, axial compression applied to the line moves it into the second position. It can also be moved into the second position by removing tension applied to the line or removing compression applied to the line. 
     A method according to the present invention provides for passing suture through tissue. The method comprises the steps of: capturing a suture into a recess in a suture capture fitting on a distal end of an elongated delivery member; passing the suture through the tissue via the delivery member; and expelling the suture out of the recess through a lateral opening into the recess via an expeller in the recess. 
     In one aspect of the invention, a surface on the expeller is moved across the recess toward the lateral opening to push the suture out of the lateral opening. The expeller can comprise a line affixed adjacent the lateral opening and received within the recess so that it is spaced apart from the opening in a first position and adjacent the lateral opening in a second position such that the line is moved from the first position to the second position to expel the suture out of the lateral opening. The method can further comprise the step of biasing the line into the first position. The method can further comprise the step of applying, removing, increasing, or decreasing tension or compression to the line to move it into the second position. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side elevation view of a suture passer according to the present invention; 
         FIGS. 2A to 2C  are side elevation views of a suture grasping mechanism with an expelling feature at a distal end of the suture passer of  FIG. 1 ; 
         FIGS. 3A to 3C  are side elevation views of a further suture grasping mechanism according to the present invention with an alternative expelling feature; 
         FIG. 4  is a side elevation view of a further suture grasping mechanism according to the present invention with an alternative expelling feature; 
         FIG. 5  is a side elevation view of an alternative suture grasping mechanism for a suture passer according to the present invention; 
         FIGS. 6A to 6C  are side elevation views of a further suture grasping mechanism according to the present invention; 
         FIGS. 7A to 7C  are side elevation views of a further suture grasping mechanism according to the present invention; and 
         FIGS. 8A to 8C  are side elevation views of a further suture grasping mechanism according to the present invention. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  illustrates a suture grasper  10  according to the present invention. It comprises in gross an elongated shaft  12  having a distal grasping mechanism  14  and a proximal scissor handle  16 . The grasping mechanism  14  comprises a suture capture recess  18  having a lateral opening  20  and an articulating jaw  22 . The handle  16  comprises a fixed arm  24  and an articulating arm  26  connected to the articulating jaw  22  via a rod or wire  28  whereby articulation of the arm  26  translates into articulation of the jaw  22 . 
     Turning also now to  FIGS. 2A to 2C , the shaft  12  optionally terminates with a sharp distal tip  30  for passing a portion of the shaft  12  and the grasping mechanism  14  through tissue (not shown) to grab or release a suture  32 . The suture  32  is captured in the recess  18  ( FIG. 2A ). It can then be manipulated in a procedure such as being pulled back through the tissue. To release the suture  32  the jaw  22  is opened ( FIG. 2B ). 
     To assist in releasing the suture  32  from the recess  18  an expeller wire  34  is bowed outwardly toward the opening  20  to push the suture  32  out of the opening  20  ( FIG. 2C ). The expeller wire  34  is preferably a flexible but stiff wire that will bow when put into compression. It could be formed from a superelastic material such as NITINOL, but the invention need not be limited thereto. Other suitable materials include nylon, stainless steel, polyesters and elastomeric materials. The wire  34  preferably terminates in a ball  36  received within a cup  38  within the recess  18 . The cup  38  can be open or partially enclosed so as to retain the ball  36  therein while allowing rotation. Preferably, the cup  38  opens toward the opening  20  to encourage the wire  34  to rotate and bow in such direction when placed into compression. The wire  34  extends along the shaft  12  and terminates at the handle  16  in a button  40  or other mechanism to allow a user to apply compressive force thereto. Alternatively, the wire  34  could also be connected to the articulating arm  26  of the handle  16  so that a single action by a user would open the jaw  22  and activate the expeller wire  34  to expel the suture  32  from the recess  18 . 
     Other configurations for the wire  34  are possible. It can be pre-bent in the direction of the opening  20  to encourage it to bow in that direction under compression. This feature can be incorporated into the wire  34  along with the ball  36  and cup  38  or with some other attachment of the wire  34 , such as the wire simply being welded to the wall of the recess  18 . Rather than terminate in a ball  36  the wire  34  could terminate in a cylinder (not shown) received in a transverse bore adjacent the recess  18  with the wire  34  movable in a closed ended slot open toward the opening  20  thereby promoting rotation of the cylinder and wire toward the opening upon compression of the wire  34 . The compression applied is relative to any force on the wire  34  when it is in the position within the recess shown in  FIG. 2A . For instance, if an open cup  38  is employed the wire might be biased toward the cup  38  to hold it in place and then when additional compressive force is applied the wire  34  will bow outwardly toward the opening  20 . 
     Turning also now to  FIGS. 3A to 3C  an alternative embodiment of a suture grasper  50  is shown wherein tension force applied to an expeller wire  52  initiates the expelling action. The grasper  50  comprises a grasping mechanism  54  on a distal end  56  of a shaft  58  and having a recess  60  with a lateral opening  62  enclosed by an articulating jaw  64  across the opening  62  ( FIG. 3A ). The wire  52  terminates in a distal, transverse cylinder  66  which rotates in a transverse bore  68  adjacent to the recess  60 . A closed end slot  70  is open toward the opening  62  to encourage the cylinder  66  and wire  52  to rotate toward the opening when tension is applied to the wire  52 . The wire  52  is pre-bent to normally bow outwardly away from the opening  62  leaving the recess  60  open for receipt of a suture  72  ( FIG. 3B ). A groove  74  in the wall of the recess  60  adjacent the jaw  64  allows the wire  52  to follow a path into the recess  60  without obstructing the recess  60 . When tension force is applied to the wire  52  it straightens and moves toward the opening  62  to eject the suture  72  from the recess  60  ( FIG. 3C ). A slot  76  in the jaw  64  allows the wire  52  to take this configuration unimpeded by the jaw  64 . The term “tension” is used here relative to the state of the wire  52  as shown in  FIGS. 3A and 3B  in which the wire could be put into less compression to encourage it to bow outwardly away from the opening  62  than it was in  FIG. 3A . 
       FIG. 4  illustrates a further embodiment of a suture grasper  80  having a recess  82  with a lateral opening  84  and an articulating jaw  86  enclosing the opening  84 . The recess  82  is C-shaped and forms a distal lip  88 . This feature aids in capturing suture (not shown in  FIG. 4 ) into the recess  82  but can impair release of suture from the recess  82 . A first end  90  of an expeller rod  92  attaches to the lip  88  adjacent the opening  84  and is received within a groove  94  in the wall of the recess  82  which extends partially therealong from the lip  88 . An actuating rod or wire  96  attaches to a second end  98  of the rod  92  to control its articulation from position received within the groove  94  leaving the recess  82  fully open to a position as shown in  FIG. 4  where it is moved partially toward the opening  84  to bridge the overhang of the lip  88  and to thereby reduce or eliminate the ability of the lip  88  to entrap suture in the recess  82 . It does not fully expel the suture but allows it to more easily move out of the recess  82  unimpeded by the lip  88 . The rod  92  can be formed of a resilient material to encourage it to bow into the groove  94 . Alternatively, a wire as in the previous embodiments could be substituted for the rod  92  and be oriented similarly to operate to diminish the effect, when desired, of the lip  88 . Another option would be to form an effective lip with the wire such as with a living hinge point. 
       FIG. 5  illustrates a further embodiment of a suture passer  100  according to the present invention. It comprises an elongated shaft  102  terminating in a sharp distal tip  104  for penetrating tissue (not shown) with a grasping mechanism  106  immediately proximal thereto. The penetrating mechanism  106  comprises a recess  108  formed of a wall  110  and having a distal overhanging lip  112 . It further comprises a lateral opening  114  which can be spanned by an articulating jaw  116  pivotable about an axis  118 . An ejector arm  120  connects to and articulates in unison with the jaw  116 . When the jaw  116  is in a closed position, spanning and closing the opening  114 , the ejector arm  120  is received deeply within the recess  108 . A groove (not shown) can be provided in the wall  110  to receive the ejector arm  120  to minimize or eliminate its obstruction of the recess  108  in this position. When the jaw  116  is pivoted outwardly away from the opening  114  the ejector arm  120  pivots outwardly away from the wall  110  forming the recess  108 , preferably connecting to the lip  112 . If suture (not shown in  FIG. 5 ) is received within the recess  108  it will now be possible to slip the suture out of the recess  108  without it getting caught up on the lip  112 . The jaw  116  and ejector arm  120  form a V-shaped opening in this position suitable for suture capture. To enhance capture employing the lip  112  to snag a suture a user can place the jaw  116  and ejector arm  120  into an intermediate position in which the opening  114  is not closed by the jaw  116  and the lip  112  is not completely obstructed by the ejector arm  120 . Alternatively, the jaw  116  and ejector arm  120  can be adapted for independent articulation. 
       FIGS. 6A to 6C  illustrate a further embodiment of a suture grasper  200  according to the present invention. It comprises a shaft  202  having a suture capture recess  204  having a lateral opening  206  and an articulating jaw  208 . An expeller wire  210  at the recess  204  is placed in tension during capture of a suture  212  to hold the wire  210  out of the path of the suture  212  into the recess  204  ( FIG. 6A ). The jaw  208  is closed to hold the suture  212  in the recess  204  and preferably the expeller wire  210  is maintained in tension during this time ( FIG. 6B ). When it is desired to expel the suture  212  the articulating jaw  208  is opened and tension is released on the expeller wire  210  ( FIG. 6C ). The expeller wire  210  has a preformed curvature  214  which when the tension is released expels the suture  212  from the recess  204 . Preferably the expeller wire is formed of a superelastic material. 
       FIGS. 7A to 7C  illustrate a further embodiment of a suture grasper  220  according to the present invention. It comprises a shaft  222  having a suture capture recess  224  having a lateral opening  226  and an articulating jaw  228 . An expeller wire  230  is affixed adjacent the opening  226  and when under no or reduced tension has a preformed shaped which forms a lip  232  at the recess  224  and also a curvature  234  into the recess  224 . Suture  236  is captured into the recess  224  with the assistance of the lip  232  ( FIG. 7A ) and then retained therein by closure of the jaw  228  ( FIG. 7B ). To eject the suture  236  the jaw  228  is opened and tension applied to the expeller wire  230  to straighten it thereby eliminating, or substantially reducing, the curvature  234  and the lip  232  thus pushing the suture  236  out of the recess  224 . 
       FIGS. 8A to 8C  illustrate a further embodiment of a suture grasper  250  according to the present invention. It comprises a shaft  252  having a suture capture recess  254  having a lateral opening  256  and an articulating jaw  258 . An ejector  260  having a curvature  262  is positioned within the recess  254 . Preferably it comprises a wire. The ejector  260  is rotatable such that during capture of a suture  264  ( FIG. 8A ) the curvature  262  is away from the opening  256  to allow entry of the suture  264  into the recess  254 . The jaw  258  is then closed to hold the suture  264  in the recess  254 . To eject the suture  264  the jaw  258  is opened and the ejector is rotated to swing the curvature  262  toward the opening  256  thereby pushing the suture  264  out of the recess  254 . 
     While the invention has been particularly described in connection with specific embodiments thereof, it is to be understood that this is by way of illustration and not of limitation, and that the scope of the appended claims should be construed as broadly as the prior art will permit.

Technology Classification (CPC): 0