Abstract:
A suture clamp comprising a plurality of elements positioned together in a row, each element of the plurality of elements having a lower portion separated from an upper portion by a flexible neck, each element of the plurality of elements including a slot having an outwardly facing opening, the slots from the plurality of elements configured to accept a suture element through the row of elements and secure the suture element. A method of clamping a suture, including applying a biasing force to at least one element into the first position to provide access to the outwardly facing opening of the slot, passing the suture through a tissue layer, receiving the suture into the slot through the outward facing opening, and removing the biasing force to form a tortuous path between adjacently positioned elements of the plurality of elements.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This is a continuation application of U.S. patent application Ser. No. 11/461,323, filed Jul. 31, 2006, and entitled “Multi Element Biased Suture Clip”, which is a continuation application of U.S. patent application Ser. No. 10/305,923, filed Nov. 26, 2002, and entitled “Multi Element Biased Suture Clip”, now U.S. Pat. No. 7,108,710, the disclosures of which are incorporated herein by this reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. The Field of the Invention 
         [0003]    The present invention relates to systems for securing a pair of suture lengths together or for using a single strand of suture to secure tissues together at an operative site in a patient without necessarily tying a knot. 
         [0004]    2. The Relevant Technology 
         [0005]    Sutures are used to sew tissue together, and thereby close tissue openings, cuts or incisions during or after any of a very wide variety of medical procedures. Typically, the surgeon manually ties together a suture pair to close the opening; however, automatic suture tying systems have also been developed. 
         [0006]    There are a number of disadvantages of knotting sutures together to secure tissues to one another. For example, manual knot tying requires considerable dexterity. Also, manual knot tying can take considerable time. Knot tying is further complicated by the fact that surgical sutures have low friction surfaces. Therefore, it is typically necessary for a surgeon to include many “throws” when tying the knot. This multiple-throw problem occurs even if an automatic knot tying device is used. Unfortunately, as the number of loops or “throws” incorporated into the knot increase, the knot becomes increasingly large and bulky. Moreover, the surgeon typically needs to handle strands of adequate suture length prior to commencing manual knot tying. Thus, manual knot tying requires considerable space both in which to view, and to perform, the actual suture knot tying. Therefore, knot tying is particularly difficult in areas of limited available space or access, such as, for example, at the back of the patient&#39;s heart during a coronary artery bypass graft (CABG) operation, or at the artery in the tissue tract after a femoral artery catheterization procedure. Manually tied knots often lock prior to reaching the intended amount of tension to be applied to the tissue. Furthermore, tissues are typically secured together by a pair of sutures wherein each of the sutures in the pair pass through both of the tissues which are then secured together by tying off the suture pair. It would instead be advantageous to provide a system which is adapted to secure tissue with suture, but without necessarily tying a knot. 
       BRIEF SUMMARY OF THE INVENTION 
       [0007]    Embodiments of the present invention provide a suture clamping system. The present suture clamping system can be used to clamp a suture pair, or to use a single strand of suture to secure tissues together. In one embodiment, a plurality of elements define a slot sized to accept a suture element through the row of elements when at least one of the elements is in a first position, and wherein a tortuous path is formed through the row of elements when at least one of the elements is in a second position. 
         [0008]    In various embodiments, the slot is generally parallel to the length of the row. In various embodiments, the at least one of the elements is a flexible element which is in the second position when not biased, and which moves into the first position when biased. In various embodiments, the direction in which the flexible element is biased is generally transverse to the length of the row. 
         [0009]    In various embodiments, the present invention comprises a plurality of adjacent flexible elements connected together in a row. The elements are biased to first positions which define an opening slot along the row of elements. A tortuous path is formed through the elements when the elements are not biased. 
         [0010]    Still other embodiments may also include a biasing/positioning device which is used to bias and hold the row of elements in the first position (at which time an opening is defined along the top of the row for receipt of the suture length or suture pair therein). Preferably, the biasing device is slidably received around the row of elements such that as the biasing force is removed, (e.g.: as the row of elements are slidably pushed or otherwise advanced through the biasing device), the elements then move to a non-biased position (at which time a tortuous path is formed along through the row of elements). Thus, a suture pair can effectively be clamped or “fastened” together when the sutures are held in such a tortuous path. Features of the present invention allow a physician to completely avoid manual suture knot tying. Therefore, the bulky multiple loops or “throws” required when knot tying can be minimized or eliminated. Instead, the suture pair is simply “clamped” or held together between the flexible elements. 
         [0011]    Alternatively, the present system can be clamped onto a single suture and can thus act as an anchor preventing movement of a tissue layer along a single suture strand. Specifically, when using only a single strand of suture, the suture is clamped so that it does not move with respect to the clamping system. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is a perspective view of a single flexible element. 
           [0013]      FIG. 2  is a perspective view of row of flexible elements as individually illustrated in  FIG. 1 , with the elements in a non-biased position, forming a tortuous path therethrough. 
           [0014]      FIG. 3  is an end view of the row of flexible elements as illustrated in  FIG. 2 . 
           [0015]      FIG. 4  is a perspective view of row of flexible elements as individually illustrated in  FIG. 1 , with the elements biased into a first position such that an opening slot forms along the top of the row. 
           [0016]      FIG. 5  is a perspective end view of the row of flexible elements as illustrated in  FIG. 4 . 
           [0017]      FIG. 6  is an end elevation view of the row of flexible elements as illustrated in  FIGS. 4 and 5 . 
           [0018]      FIG. 7  is a perspective view of an alternate design of a row of flexible elements, with the elements in a non-biased position, forming a tortuous path therethrough. 
           [0019]      FIG. 8  is a perspective view of the row of elements of  FIG. 7 , with the elements biased into a first position such that an opening slot forms along the top of the row. 
           [0020]      FIG. 9  is a perspective end view of a dual rail biasing device slidably received over the row of flexible elements, with the elements in a non-biased position, as shown in  FIGS. 2 and 3 . 
           [0021]      FIG. 10  is in a view similar to  FIG. 9 , but including as suture pair received in the slot formed through the row of elements. 
           [0022]      FIG. 11  is a perspective end view of the row of flexible elements after it has been pushed fully through the dual rail biasing device, such that the elements return to a non-biased position, trapping the suture pair in a tortuous path therein, as shown in  FIGS. 2 and 3 . 
           [0023]      FIG. 12  is a top plan view corresponding to  FIG. 11 . 
           [0024]      FIG. 13  is an exploded perspective view of an embodiment of the invention having two non-flexible elements with a single flexible element positioned therebetween. 
           [0025]      FIG. 14  is a perspective view of an embodiment of the invention further comprising a suture guide assembly, a pair of flexible suture capture elements and a rail guide. 
           [0026]      FIG. 15  is an exploded perspective view of the invention shown in  FIG. 14 . 
           [0027]      FIG. 16A  is a front elevation view of the embodiment of the invention shown in  FIG. 14  in a closed position. 
           [0028]      FIG. 16B  is a front elevation view of the embodiment of the invention shown in  FIG. 14  in an open position. 
           [0029]      FIG. 17A  is a rear view of the suture guide assembly in a closed position (corresponding to  FIG. 16A ). 
           [0030]      FIG. 17B  is a rear view of the suture guide assembly in an open position (corresponding to  FIG. 16B ). 
           [0031]      FIG. 18A  is a front view of a pair of suture capture elements in a non-biased position. 
           [0032]      FIG. 18B  is a front view of a pair of suture capture elements in a biased position, thus forming a suture opening therethrough. 
           [0033]      FIG. 19  is a top perspective view of the device of  FIG. 14 , positioned on a pair of rails prior to deployment. 
           [0034]      FIG. 20  is a view similar to  FIG. 19 , but with the device advanced to a position such that the rails cause the device to open to receive a suture pair therein. 
           [0035]      FIG. 21  is a view similar to  FIG. 20 , but with the device advanced to a position such that the suture guide assembly projects beyond the distal ends of the rails, showing the suture guide assembly locking onto the suture pair. 
           [0036]      FIG. 22  is a view similar to  FIG. 21 , but with the entire device advanced beyond the distal ends of the pair of rails, showing the suture capture elements locking onto the suture pair. 
       
    
    
     DETAILED DESCRIPTION 
       [0037]    In accordance with the present invention, a suture clamping system is provided. In preferred aspects, the suture clamping system comprises a plurality of individual flexible elements positioned together in a row. In various preferred embodiments, the individual flexible elements are shaped the same. Optionally, the row of elements is formed by positioning successive identically shaped elements adjacent to one another. It is to be understood, however, that the individual elements in the row need not be identical in shape to one another. It is also to be understood that the individual elements need not be positioned in direct “touching” contact side-by-side with one another, but may instead be positioned some distance apart from one another. As will also be explained, various embodiments of the invention may include rows of elements including both flexible and non-flexible elements. In fact, in one embodiment, only one flexible element is required. 
         [0038]    One or more of these elements are preferably biased in a direction transverse to the length of the row. When biased, one or more flexible elements move to a first position at which the elements define a slot along the length of the row. The slot is specifically sized to receive a suture therein. When not biased, the one or more flexible elements return to a second (non-biased) position. When in a non-biased position, the elements form a tortuous path for the suture received therein. 
         [0039]      FIGS. 1 to 6  illustrate a first preferred embodiment of the present invention, and  FIGS. 7 and 8  illustrate a second preferred embodiment of the present invention.  FIGS. 9 to 12  illustrate an exemplary positioning/biasing device for use with various embodiments of a suture clamp.  FIG. 13  illustrates an embodiment of the invention having only one flexible element.  FIGS. 14 to 18B  show component parts of an embodiment of the device having a suture guide assembly, a pair of flexible suture capture elements, and a rail guide.  FIGS. 19 to 22  show sequential steps in the deployment of the embodiment of the device shown  FIGS. 14 to 18B . 
         [0040]      FIG. 1  illustrates an embodiment of a single clamping element  10 . Element  10  has a lower portion  11 , a neck  12 , and an upper portion  13 . A slot  14  is defined by upper portion  13 . Also, an optional projection  15  extends longitudinally from upper portion  13 . As will be explained, projections  15  provide contact surfaces between adjacent elements such that the elements may rest against one another when in a non-biased (second) position. It is to be understood that projections  15  are optional and that various embodiments of the present invention do not require projections  15  to operate. 
         [0041]    Element  10  is preferably fabricated from a unitary block of Nitinol or other suitable flexible or elastic material, including various plastics and metals. Photochemical machining or other known techniques may be used to form element  10 . Most preferably, each element  10  will be dimensioned to about 1 mm in height. 
         [0042]    As can be seen in  FIGS. 2 and 3 , a plurality of flexible elements  10  (i.e.:  10 A,  10 B,  10 C,  10 D, etc.) can be positioned side-by-side forming row  20 . Preferably, lower portions  11  of the successive elements  10  are positioned adjacent to one another such that their projections  15  interlock with upper portions  13  of adjacent elements (as shown in  FIG. 2 ). Lower portions  11  of the successive elements  10  may optionally be connected together (side-by-side) by a variety of techniques, including fusion bonding and adhesives. Alternatively, lower portions  11  of the successive elements  10  may optionally be spaced some distance apart from one another (not shown). 
         [0043]    In another embodiment, elements  10  may each optionally comprise a pair of holes  16  (see  FIG. 1 ) such that elements  10 A,  10 B,  10 C,  10 D, can be positioned on rods  30  and  32 , or a similar mounting element or structure. 
         [0044]    In accordance with the present invention, a biasing force (“F” in  FIG. 3 ) is applied to the upper portions of each of elements  10 . Biasing force F is applied in a direction generally transverse to the length of the row. Thus, as can be seen, force F will squeeze row  20  from its sides. The bottom portions  11  of each of elements  10  are held in a constant position with respect to one another. Alternatively, an embodiment of the present invention may include a single unitary bottom portion (as opposed to the illustrated plurality of separate bottom portions  11 ). Thus, the device which comprises the row of elements can be machined or molded out of a solid block of material such that the elements have a common bottom portion (for example, as illustrated in  FIG. 13 ). Having a thin neck  12 , the upper portions  13  of each of elements  10  will tend to move apart in a direction transverse to the row of elements as biasing force F is applied. 
         [0045]    As shown in  FIGS. 4 to 6 , when a sufficiently strong biasing force F is applied, elements  10  move to a first position in which a slot  22  forms along the top of row  20 . (i.e. when adjacent slot defining features  14  in successive elements  10  are in alignment). At this time a pair of sutures  40  and  42  (see  FIG. 10 ) can be positioned within slot  22 . When force F is removed, elements  10  will naturally tend to return to their non-biased (or possibly biased against one another) position, at which time an upper portion  13 A of a first element ( 10 A) will abut against projection  15 B of upper portion  13 B of a second element ( 10 B), as shown in  FIGS. 2 and 3 . 
         [0046]    The flexible elements which are used to form the suture clamping device can be made in a variety of different shapes. For example, referring to  FIGS. 7 and 8 , a row  200  of flexible elements  100 A,  100 B,  100 C,  100 D,  100 E, etc. are used to form a suture clamping device. Specifically, as shown in the non-biased position (i.e.  FIG. 7 ), elements  100  each have a lower portion  110 , a neck  120  and an upper portion  130 . Upper portion  130  has a slot defining features  140  formed therein. As can be seen, element  110  is formed such that its neck  120  holds upper portion  130  (and slot defining features  140 ) at an angle when in the non-biased ( FIG. 7 ) position. 
         [0047]    Thus, when a squeezing force F is applied against flexible elements  100  on either side of row  200 , elements will be biased into the position shown in  FIG. 8  wherein the slot-defining features  140  of successive elements are positioned in alignment with one another to form a slot  122 . A pair of sutures  40  and  42  can then be placed into slot  122 . When the biasing force F is released, elements  110  will tend to move back to the position shown in  FIG. 7 , thus forming a tortuous path for sutures  40  and  42 , passing therethrough. 
         [0048]    In an alternate embodiment, the elements are formed such that a suture slot is instead formed when the elements are in their non-biased position. In such an embodiment, the application of a biasing force would move the elements into a position such that the tortuous suture path is formed therethrough. After the elements have been biased to move into positions forming the tortuous suture path therethrough, a clip or other fastening device can be used to hold the elements in the biased position, with the tortuous suture path passing therethrough. 
         [0049]    Sutures  40  and  42  may preferably comprise opposite ends of a continuous suture loop which has been used to suture together an anastomosis graft or to close a hole in a blood vessel or other tissue wall, or to anchor one or more suture elements. Alternatively, sutures  40  and  42  may comprise ends of separate suture strands which are fastened (i.e. clamped) together by present invention. 
         [0050]    In accordance with preferred aspects of the present invention, a method for clamping a suture pair is also provided. Preferably, this method includes biasing the row of adjacent flexible elements  10  (i.e.: applying force F) so that elements  10  move to the position (as shown in  FIGS. 4 to 6 ) in which an opening slot  22  is formed therethrough. Preferably, this biasing force is applied in a direction transverse to the length of the row. Then, suture pair  40  and  42  is received into opening slot  22 . Then, biasing force F is removed such that the adjacent flexible elements  10 A,  10 B,  10 C,  10 D, etc., move to positions which hold the suture pair in a tortuous path (as shown in  FIGS. 2 and 3 ). Similarly, as seen in  FIGS. 7 and 8 , the present method may comprise: biasing the row of adjacent flexible elements  100  (i.e.: applying force F) so that elements  100  move to the first position (as shown in  FIG. 9 ) in which an opening slot  122  is formed there along. Then, suture pair  40  and  42  is received into opening slot  122 . Then, biasing force F is removed such that the adjacent flexible elements  100 A,  100 B,  100 C,  100 D, etc., move or spring back to positions which hold the suture pair in a tortuous path (as shown in  FIG. 7 ). 
         [0051]    The present method will be explained by reference to a dual rail positioning/biasing device shown in  FIGS. 9 to 12 , as follows. 
         [0052]    A biasing device  50  may be provided as part of the present suture clamping system. In one embodiment, biasing device  50  comprises two rails  51  and  52  which are parallel to one another over two regions, and angled with respect to one another over another region. Specifically, as seen in  FIG. 9 , rails  51  and  52  are parallel with respect to one another in regions  54  and  58  and are angled with respect to one another in region  56 . As also seen in  FIG. 9 , a push rod  60  is used to successively push elements  10 A,  10 B,  10 C and  10 D distally from region  58 , and then through regions  56  and  54 . 
         [0053]    From the position shown in  FIG. 9 , push rod  60  is advanced such that row  20  of elements  10  is pushed into region  54  (as shown in  FIG. 10 ) wherein rails  51  and  52  are positioned closer together, such that individual slot defining features  14  are put into alignment (forming slot  22  along the length of row  20 ). As shown in  FIG. 10 , a suture pair  40 ,  42  can then be positioned within slot  22 . Lastly, as shown in  FIGS. 11 and 12 , row  20  is pushed out of the distal end of biasing device  50 . As shown in  FIG. 12 , the biasing force on the sides of row  20  is removed such that elements  10 A,  10 B,  10 C and  10 D return to their non-biased position, thus forming a tortuous path for suture pair  40  and  42  passing therethrough. 
         [0054]    As stated above, the present invention may comprise a plurality of flexible elements. It is to be understood, however, that embodiments of the invention may also comprise non-flexible elements, or various combinations of flexible and non-flexible elements. For example, as shown in  FIG. 13 , a row  300  of elements (which may optionally have a single unitary base  310 ) may have a single flexible element  300 B disposed between (or otherwise adjacent to) non-flexible elements  300 A and  300 C. When a biasing force F is applied to the sides of the device, flexible element  300 B will move to a position such that elements  300 A,  300 B and  300 C will be placed in alignment. Then, a suture, or suture pair can easily be threaded through opening slots  340 A,  340 B and  340 C. When biasing force F is removed, element  300 B will tend to spring back into the position shown in  FIG. 13 , thereby forming a tortuous path, firmly holding the suture(s) therein. 
         [0055]      FIGS. 14 to 18B  show an alternate embodiment of the present invention that includes a suture clamp assembly  500  including a suture guide assembly  502 , a pair of flexible elements  510 A and  510 B and a rail guide  520 . Suture guide assembly  502  includes a suture guide  503  and a suture lock  504 . As can be seen in  FIGS. 16A to 17B , suture lock  504  is movable with respect to suture guide  503 , thus permitting a suture or suture pair to be inserted therebetween, and then clamped, as follows. As shown in  FIGS. 16A and 17B , suture lock  504  is initially position adjacent to suture guide  503  (by the action of spring  505 ). When using the device, the end of suture lock  504  which extends in to cavity  521  in rail guide  520  is pushed. Such force compresses spring  505  so that suture lock  504  moves to the position shown in  FIGS. 16B and 17B , thereby opening passageway  506 , permitting a suture, or suture pair to be inserted therein. Thereafter, the force can be removed from the end of suture lock  504  which extends in to cavity  521  such that, spring  505  expands and suture lock  504  returns to the position shown in  FIGS. 16A and 17A , thereby trapping a suture or suture pair in passageway  506 . 
         [0056]    Behind suture guide assembly  502  are positioned one or more flexible elements which are used to capture a suture or suture pair. These flexible elements operate in the same manner as the “row of flexible elements” described with regard to other embodiments herein. Specifically, flexible elements  510 A and  510 B have a non-biased position as shown in  FIG. 18A . When a biasing force is applied to the underside of projections  511 , flexible elements  510 A and  510 B move to the positions shown in  FIG. 18B , at which time their slots  512  move into alignment with one another. When slots  512  of flexible elements  510 A and  510 B are positioned in alignment, a suture or suture pair can be received therein. Then, the biasing forces can be removed from projections  511 , causing the flexible elements to move towards the position shown in  FIG. 18A , thereby forming a tortuous path for a suture passing therethrough. It is to be understood that the present invention encompasses embodiments with more than two flexible suture capture elements  510 , or even as few as one flexible and one non-flexible element. 
         [0057]    In optional preferred aspects, both the suture guide  503  and the suture lock  504  are dimensioned such that the opening slot  507  (formed in passageway  506  in which the suture(s) are trapped) is not co-linear with the opening slots  512  through flexible elements  510 A and  510 B. An advantage of opening slot  507  not being co-linear with the path through opening slots  512  is that this further adds to the tortuosity of the suture path through the device, and permits more exact positioning of the device with respect to the target tissue. 
         [0058]      FIGS. 19 to 22  show the deployment of the embodiment of the invention shown in  FIGS. 14 to 18B , as follows. As shown in  FIG. 19 , suture clamp assembly  500  is initially positioned between rails  602 , with a push rod  610  abutting against the rear of rail guide  520 . Next, push rod  610  is used to advance the suture clamp assembly  500  to the position shown in  FIG. 20  where the spacing between rails  602  narrows. Thus, one of the rails  602  will push on the end of suture lock  504  in cavity  512  so that suture lock  504  moves apart from suture guide  503 , as explained above. In addition, advancing flexible elements  510 A and  510 B to the region where the spacing of rails  602  narrows will move flexible elements  510 A and  510 B to their biased position ( FIG. 18B ). At this time, a pair of sutures  40  and  42  can be received therein. Next, push rod  610  is used to advance the suture clamp assembly  500  to the position shown in  FIG. 21  where suture guide assembly  502  is advanced beyond the distal end of the rails  602 . Accordingly, suture lock  504  moves back into position against suture guide  503 , thereby trapping sutures  40  and  42  therebetween. Lastly, as shown in  FIG. 22 , push rod  610  is used to fully push assembly  500  out beyond the distal end of rails  602 . At this time, flexible elements  510 A and  510 B spring back to their non-biased positions, thus forming a tortuous path for sutures  40  and  42  passing therethrough. Accordingly, the row of flexible elements  510 A and  510 B assist suture guide assembly  502  in clamping onto sutures  40  and  42 , thereby operating as a system which fastens the sutures together. In accordance with this embodiment of the invention, the suture guide assembly  502  fastens onto the suture (or suture pair) prior to flexible elements  510 A and  510 B fastening onto the suture(s). The suture guide assembly  502  can be positioned immediately adjacent to the tissue target site, if desired. After the suture guide assembly  502  has clamped onto the suture(s), the flexible elements  510 A and  510 B will sequentially clamp onto the suture(s), thereby taking up any slack in the suture(s) from the proximal side of the device. In other words, as each of the elements in the row of flexible elements is sequentially pushed out from between rails  602 , the flexible elements will sequentially move to their non-biased positions, drawing in suture through rail guide  520 . Since the suture is pulled in from the rail guide (i.e. the proximal) end of the device, it will not pull on the suture(s) from the suture guide assembly (i.e. the distal) end of the device. This minimizes inadvertent pulling on the sutures at the target tissue location (i.e. at the distal) end of the device). 
         [0059]    The present system can be positioned directly adjacent to the operative site at which it is desirable to secure the suture pair. Specifically, the present system can be deployed without pulling suture at the surgical site as the suture pair is secured together. Rather, in preferred embodiments, as the present system is deployed, it pulls in suture from end of the clamp positioned away from the operative site. In contrast, manual or even automatic knot tying systems may either result in a loose knot being positioned at a small distance away from the operative site, or an overly tight knot pulling excessively on the tissues. 
         [0060]    In addition, the present system can minimize the extent to which suture at the surgical site is pulled as it secures the suture(s). As the present system is deployed, it simply tightens together a suture pair at the operative site. In contrast, when tying together a suture pair, it is typically difficult to tie a knot very close to the operative site without excessively pulling on the tissues being tied together. 
         [0061]    The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.