Abstract:
The suture retainer according to one aspect of the invention has a retainer body and a plurality of suture attachment mechanisms spaced circumferentially about the retainer body, each of the suture attachment mechanisms (such as a pair of teeth) being adapted to hold a suture strand at a discrete attachment point. Another aspect of the invention provides a method of securing a suture in a suture retainer, including the following steps: providing a suture retainer having a retainer body and a plurality of suture attachment mechanisms spaced circumferentially about the retainer body; and attaching a suture strand to the retainer body at each of the suture attachment mechanisms. Yet another aspect of the invention provides a suturing method including the steps of: attaching a first end of a suture strand to a suture retainer; contacting a tissue contact portion of the suture strand with tissue to be sutured, the tissue contact portion being disposed between the first end of the suture strand and a second end of the suture strand; and attaching the second end of the suture strand to the suture retainer at a plurality of suture attachment points spaced circumferentially about the suture retainer.

Description:
BACKGROUND OF THE INVENTION 
     The invention relates generally to suture retainers and methods of using suture retainers. In particular, the invention relates to suture retainers that hold a suture strand at a plurality of circumferentially spaced points about the suture retainer. 
     Sutures are used for a variety of surgical purposes, such as approximation of tissue and ligation of tissue. Most generally, when placing sutures, the strand of suture material to be used has a needle affixed to one end. The needle is passed through the tissue to be approximated or ligated, forming a stitch. The stitch is then tensioned appropriately, and the two ends of the suture, the needle end and the non-needle end, are knotted to retain the desired tension in the stitch. Sometimes the ends are knotted together; in other instances they may be stoppered separately, often with the aid of a clip or other device to form resistance to passage through tissue. While forming knots in suture during open surgery is a simple matter, forming knots in suture during endoscopic surgery can be very difficult. 
     Suture retainers may be used in place of suture knots to prevent passage of a suture end into and through tissue and to maintain the tension applied to the suture material during the suturing procedure. Suture clips and other suture retainers are described in the following publications: U.S. Pat. Nos. 5,234,449; 5,383,905; 5,391,173; 5,643,295; 5,645,553; 5,735,877; 5,845,645; 5,895,393; 6,015,428; 6,066,160; 6,231,592; and 6,432,123. 
     SUMMARY OF THE INVENTION 
     The present invention provides a suture retainer with multiple circumferentially spaced attachment points. The invention also provides a suture retainer with a suture guide mechanism adapted to maintain an angle between a suture strand and a suture attachment mechanism. While the suture retainer of this invention can be used in conventional open surgeries or external surgeries, the invention is particularly useful for endoscopic suturing. 
     The suture retainer according to one aspect of the invention has a retainer body and a plurality of suture attachment mechanisms spaced circumferentially about the retainer body, each of the suture attachment mechanisms (such as a pair of teeth) being adapted to hold a suture strand at a discrete attachment point. In some embodiments, each suture attachment mechanism is adapted to releasably hold the suture strand. 
     In some embodiments of the invention, the suture retainer also has a suture guide mechanism, such as a projection from the retainer body, adapted to maintain an angle between the suture strand and one of the suture attachment mechanisms. The suture guide mechanism may be adapted to be a first contact point of the suture strand with the suture retainer. 
     In some embodiments, the suture attachment mechanisms are needle-end suture attachment mechanisms, with the suture retainer also including a non-needle-end suture attachment mechanism adapted to hold a non-needle-end of the suture strand. The non-needle-end suture attachment mechanism may be disposed radially inward from each of the needle-end suture attachment mechanisms. Also, in some embodiments, the retainer body has a first member and a second member, with at least a portion of the second member being adapted to be inserted into the first member to form the non-needle-end suture attachment mechanism, such as a slot in the second member which interacts with the first member to hold the non-needle-end of the suture strand. The suture retainer may also have an alignment mechanism adapted to orient the second member with respect to the first member. In some embodiments, the suture retainer also has a movable connection between the first member and the second member, and in some embodiments the suture retainer has a snap connection between the first member and the second member. In some embodiments, a suture guide mechanism may project from the first and/or second member. 
     Another aspect of the invention provides a method of securing a suture in a suture retainer, including the following steps: providing a suture retainer having a retainer body and a plurality of suture attachment mechanisms spaced circumferentially about the retainer body; and attaching a suture strand to the retainer body at each of the suture attachment mechanisms. In some embodiments, each suture attachment mechanism is at least a pair of teeth, with the method further including the step of inserting the suture strand between each of the pairs of teeth. The method may also include the step of releasing the suture strand from the suture attachment mechanisms after the attaching step and possibly the step of reattaching the suture strand to the suture attachment mechanisms after the releasing step. 
     In some embodiments the method also includes the step of contacting the suture strand with a suture guide to maintain an angle between the suture strand and one of the suture attachment mechanisms. The contacting step may include the step of contacting with the suture guide a portion of the suture strand between a point where the suture strand leaves a tissue surface and a point where the suture strand contacts a suture attachment mechanism. 
     In some embodiments, the attaching step includes the step of attaching a needle-end of the suture strand to needle-end suture attachment mechanisms, with the method further including the step of attaching a non-needle-end of the suture strand to the suture retainer. The retainer body may include a first member and a second member, and the step of attaching the non-needle-end of the suture strand may include the step of inserting at least a portion of the second member into the first member to hold the non-needle-end of the suture strand. In embodiments in which the retainer body has a movable connection between the first member and the second member, the inserting step may include the step of moving the second member about the movable connection with respect to the first member and possibly the step of snapping the first and second members together. 
     Yet another aspect of the invention provides a suturing method including the steps of: attaching a first end of a suture strand to a suture retainer; contacting a tissue contact portion of the suture strand with tissue to be sutured, the tissue contact portion being disposed between the first end of the suture strand and a second end of the suture strand; and attaching the second end of the suture strand to the suture retainer at a plurality of suture attachment points spaced circumferentially about the suture retainer. In some embodiments, the step of attaching the second end of the suture strand includes the step of placing the second end of the suture strand between a plurality of pairs of teeth, each pair of teeth being disposed at one of the suture attachment points. The method may also include the step of detaching the suture strand from the suture attachment mechanisms after the attaching step and possibly the step of reattaching the suture strand to the suture attachment mechanisms after the detaching step. 
     In some embodiments, the step of attaching the first end of the suture strand includes the step of inserting at least a portion of a first suture retainer body member into a second suture retainer body member. The attaching step may also include the step of placing the first end of the suture strand into a slot formed in the first suture retainer body member. The inserting step may include the step of aligning the first suture retainer body member with the second suture retainer body member, such as by rotating the second body member to align a second suture retainer body member alignment element with a first suture retainer body member alignment element. 
     Some embodiments of this aspect of the invention include the step of contacting the second end of the suture strand with a suture guide to maintain an angle between the suture strand and one of suture attachment mechanisms, such as by making a first contact of the second end of the suture strand with the suture retainer. 
     INCORPORATION BY REFERENCE 
     All publications and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The novel features of the invention are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings of which: 
         FIG. 1  is a side elevational view of a suture retainer according to one embodiment of this invention. 
         FIG. 2  is a side elevational view of the suture retainer of  FIG. 1 , partially assembled. 
         FIG. 3  is a side elevational view of a plug portion of the suture retainer of  FIG. 1 . 
         FIG. 4  is a top elevational view of the plug portion of the suture retainer shown in  FIG. 3 . 
         FIG. 5  is a medial cross-sectional view taken along line  5 - 5  of the embodiment of the suture retainer of  FIG. 1  with a suture strand laid into the attachment mechanisms. 
         FIG. 6  is a side elevational view of the wheel portion of the suture retainer shown in  FIG. 1 . 
         FIG. 7  is a perspective view of the suture retainer shown in  FIG. 1 . 
         FIG. 8  shows a suture retainer according to one embodiment of this invention in use to retain a suture strand. 
         FIG. 9  is a top elevational view of a suture attachment feature that may be used with embodiments of this invention. 
         FIG. 10  is a top elevational view of the wheel portion of yet another embodiment of the suture retainer of this invention. 
         FIG. 11  is a cross-sectional view taken along the line A-A of  FIG. 10 . 
         FIG. 12  is a side elevational view of the plug portion of the embodiment of  FIG. 10 . 
         FIG. 13  is a schematic view of an assembled suture retainer according to the embodiment of  FIGS. 10-12  showing a suture in place. 
         FIG. 14  is a top elevational view of the wheel portion of another embodiment of the suture retainer of this invention. 
         FIG. 15  is a cross-sectional view taken along the line A-A of  FIG. 14 . 
         FIG. 16  is a top elevational view of the plug portion of the embodiment of  FIG. 14 . 
         FIG. 17  is a cross-sectional view of a suture and a partially assembled suture retainer according to the embodiment of  FIGS. 14-16 , prior to use. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIGS. 1-7  show embodiments of a suture retainer  10  with two principal parts: a wheel portion  12  and a plug portion  14 . Wheel portion  12  has sets of teeth  16  arranged around its circumference. As shown best in  FIG. 7 , tooth sets  16  each have a pair of inclined facing edges  18  and  20  that diverge from the center of wheel portion  12  toward the outer circumference of wheel portion  12 . The spacing and angle of inclined surfaces  18  and  20  are chosen to engage the diameter of the suture strand with which the retainer is intended to be used. In one embodiment, for example, the angle between the inclined surfaces of each tooth set is about 10° or less. 
     In the embodiments shown in  FIGS. 1-7 , wheel portion  12  has three sets of teeth arranged about the circumference of wheel portion  12  in a manner to produce pull angles of between about 50° and 70° for each tooth set. Pull angle is defined as the angle formed on the “pull” side of the tooth set between a suture held by the tooth set and a line normal to a plane formed by the juxtaposed edges of the teeth. The tooth sets extend radially from the center of wheel portion  12  or may extend on an angle from a radius in order to provide the desired pull angle. In other embodiments, the suture retainer may have one, two or more than three sets of suture attachment mechanisms, such as the teeth shown in the embodiments of  FIGS. 1-7 . 
     A pair of plates or flanges  22  and  24  surround and support the tooth sets. Plates  22  and  24  also aid the surgeon in passing the needle end of the suture around wheel portion  12  to engage successive tooth sets. Wheel portion  12  has a central opening  26  and an alignment hole  28 . Opening  26  and hole  28  mate with corresponding portions of plug portion  14  when the suture retainer is assembled. 
     Plug portion has lock arms  30  and  32  extending from a plate  34 . Lock arms  30  and  32  have cam surfaces  36  and  38 , respectively that are adapted to bend arms  30  and  32  inward when surfaces  36  and  38  engage the edges of opening  26  in wheel portion  12 . A slot  40  is formed between arms  30  and  32 . 
     Also extending from plate  34  is a suture guide mechanism (such as hook  42  in  FIG. 1  or tab  50  in  FIG. 7 ) and an alignment member  44 . Alignment member  44  extends into alignment hole  28  when plug portion  14  is connected to wheel portion  12 . This arrangement sets the position of the suture guide mechanism (e.g., hook  42 ) with respect to one of the tooth sets  16  so that hook may serve as a retainer or guide for a suture strand as it enters a first tooth set  16 , as described below. Other means of aligning the plug and wheel portions of the suture retainer may be used, of course, without departing from the invention. 
     To use the suture retainer, the non-needle-end of a suture is inserted into the slot  40 , preferably when the suture retainer is in the partially assembled configuration shown in FIG  2 . Plug portion  14  is then advanced completely into wheel portion  12 , with alignment member  44  aligned with alignment hole  28 . As lock arms  30  and  32  move into opening  26 , cam surfaces  36  and  38  engage the edges of opening  26  to move arms  30  and  32  inward. After cam surfaces  36  and  38  have completely passed through opening  26 , arms  30  and  32  move outwardly so that lock surfaces  46  and  48  formed on arms  30  and  32 , respectively, engage the far side of plate  24  in a snap connection, as shown in  FIGS. 1 and 7 , and the suture strand is gripped firmly, preferably in a controlled clearance space between the shaft of the plug and the bore of the wheel. 
     When thus assembled, the non-needle-end of the suture strand is held firmly by suture retainer  10 . The surgeon can then pass the needle and needle-end of the suture strand through and/or around the tissue  2  to be sutured or ligated, pulling suture retainer  10  against the surface of the tissue, as shown in  FIG. 8 . When the suture stitch is complete, the surgeon passes the needle-end  6  of the suture strand  4  around and in engagement with the suture guide mechanism  42 , tensions the stitch, then guides the needle-end of the suture strand in succession into the three sets of teeth  16 , maintaining the tension in the suture strand as the surgeon progresses. If the stitch tension and suture retainer grip are satisfactory, the surgeon then may sever the unused ends of the suture strand. If, however, the stitch needs to be retensioned to either increase or decrease tissue approximation or the retainer grip needs to be adjusted, the surgeon may pull the suture strand away from the tooth sets, then retension the stitch and reengage the suture strand with the suture retainer. While the illustrations show a clockwise wrapping of the suture, other embodiments of the invention may employ counterclockwise wrapping of the suture around the retainer. 
     The shape and position of hook  42  help retain the suture strand&#39;s orientation and pull angle with respect to the first set of teeth  16  it encounters. In addition, the curved end of hook  42  helps retain the suture strand in place after the suturing procedure has been completed. Other shapes and manners of suture strand guides may be used in place of hook  42 , such as tabs, posts, rings, etc. In addition, the suture strand guide of this invention may be used with suture retainers having one, two or more than three suture attachment mechanisms. 
       FIG. 9  shows an optional feature for holding the far end of the needle-end of the suture strand after engagement with the retainer&#39;s sets of teeth. A slot  54  is formed in plate  24  of suture retainer  10 . The end of the suture strand may be placed within slot  54  to provide additional retention of the suture and to maintain the retention of the suture provided by the last set of teeth before severing and removing the needle end of the suture. The slot may be tapered or parallel, as shown, and may be used with any of the embodiments of this invention. This feature may also be used to retain one end of a suture strand without regard to whether, or the manner in which, the other end of the suture strand is retained. 
     Another embodiment of the invention is shown in  FIGS. 10-13 . Suture retainer  60  has a wheel portion  62  and a plug portion  64 . Like the previous embodiments, wheel portion  62  has sets of teeth  66  arranged about a circumference of wheel portion  62 . A pair of plates or flanges  68  and  70  surround and support the tooth sets. Wheel portion  62  also has a central opening  72  with a movable member  74  formed inside the opening. A suture guide mechanism  76  extends from wheel portion  62 . 
     Plug portion  64  has a slot  78  and a groove  80 . A tab  82  extends from the top surface of plug portion  64 . Prior to insertion (or after partial insertion) of plug  64  into wheel  62  in the direction shown by the arrow in  FIG. 11 , the non-needle-end of a suture strand  86  may be inserted into slot  78  and, if desired, wrapped around groove  80  and back through slot  78 . Plug  64  is then inserted fully into opening  72  of wheel  62  from the bottom, as shown in  FIG. 11 . As it is inserted, the plug&#39;s tab  82  pushes the top of the wheel&#39;s movable member  74  radially away from the center of opening  72 . When the plug&#39;s tab  82  reaches a space  84  above movable member  74 , movable member  74  moves back toward the center of opening  72 , snapping plug  64  in place within wheel  62 . In this position, the non-needle-end of suture strand  86  is held firmly by suture retainer  60 . The suture thread may be tensioned downward, as shown in  FIG. 13 . 
     After assembly of the suture retainer, the surgeon may then use the needle-end of the suture to perform the suturing or ligation procedure. As in the other embodiments, when the suture stitch is complete, the surgeon passes the needle-end of the suture strand around the suture guide  76 , then inserts the suture strand in succession into the sets of teeth  66 . Thereafter, the surgeon may place the needle-end of the suture strand into a slot  88  formed in plate or flange  68 . 
     In the embodiment shown in  FIGS. 10-13 , the top and bottom edges of plug  64  lie flush with the top and bottom edges of wheel  62 . This arrangement is an optional feature of the invention. Also, it should be understood that other suture attachment mechanisms and other numbers of suture attachment mechanisms may be used in the suture retainer of this invention. 
       FIGS. 14-17  show yet another embodiment of this invention. Suture retainer  100  has a wheel portion  102  and a plug portion  104 . Like the previous embodiments, wheel portion  102  has sets of teeth  106  arranged about a circumference of wheel portion  102 . A pair of plates or flanges  108  and  110  surround and support the tooth sets. Wheel portion  102  also has a central opening  112  with a movable arm  114  formed inside the opening. A suture guide mechanism  116  extends from wheel portion  112 . 
     Plug portion  104  has a pair of pins  107  extending from an upper surface. When the suture retainer is assembled prior to use, pins  107  are snapped into openings formed by pairs of arms  118  extending upward from the upper surface of flange  108  of wheel  102  to form a hinge to allow rotational movement between plug  104  and wheel  102 . Other forms of movable connection between the plug and wheel are also covered by this invention. 
       FIG. 17  shows the arrangement of plug  104  and wheel  102  prior to use of the suture retainer. A loop  120  formed in the non-needle-end of a suture strand is passed up through opening  112 . The suture strand may then be wrapped one or more times around plug  104  with the suture strand lying in grooves  122  (and groove  123 , for multiple suture wraps) formed in plug  104 . Plug  104  is then rotated downward about the hinge formed by pins.  107  and arms  118 . As the bottom of plug  104  enters opening  112 , an angled surface  124  of plug  104  engages an angled surface formed on the top of a tab  126  of movable arm  114 , pushing the top of arm  114  radially outward. When plug  104  has been completely inserted into wheel  102 , tab  126  moves radially inward into a slot  128  formed in plug  104  to latch plug  104  in place within wheel  102 . The surgeon may then use the needle-end of the suture to perform the suturing or ligation procedure. As in the other embodiments, when the suture stitch is complete, the surgeon passes the needle-end of the suture strand around the suture guide  116 , then inserts the suture strand in succession into the sets of teeth  106  to hold the suture in place. 
     The use of circumferentially spaced tooth sets provides multiple suture attachment mechanisms each at desired pull angles. This arrangement reduces the likelihood of slippage of the suture strand in the event one of the attachment points fails or provides less than 100% of the required tensioning force. Other numbers of tooth sets set at other pull angles may also be used. In addition, other attachment mechanisms may be used in place of the tooth sets described above, such as high friction surfaces, hooks, posts, rings, etc. 
     The components of the device described above can be made of medically suitable metal or plastics, including bio-absorbable polymers. Example materials include stainless steel, polycarbonate and polyglycolide. 
     While preferred embodiments of the present invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. It is intended that the following claims define the scope of the invention and that methods and structures within the scope of these claims and their equivalents be covered thereby.