Patent Publication Number: US-2003229377-A1

Title: Tube and rod suture clamping system

Description:
TECHNICAL FIELD  
       [0001] 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.  
       BACKGROUND OF THE INVENTION  
       [0002] 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.  
       [0003] 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, for example, at the back of the patient&#39;s heart during a coronary artery bypass graft (CABG) operation. 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 secured together by tying off the suture pair. It would instead be advantageous to provide a system which is adapted to secure together two tissues, but uses only a single strand of suture.  
       SUMMARY OF THE INVENTION  
       [0004] The present invention provides a suture clamping system, including a rod and a clamp. The clamp preferably has a first end into which an end of the rod is received and a second end which is dimensioned to be snap-fit around the rod. Preferably, the first and second ends of the clamp are separated by a bendable mid-section. In various embodiments, a notch is formed in the second end of the clamp for receiving one or more sutures (e.g.: a suture pair) therebetween.  
       [0005] In accordance with a preferred method, the one or more sutures are clamped by first positioning the suture(s) between a clamp and a rod, wherein the clamp has a C-shaped cross section and is dimensioned to be snap-fit around the rod; and then pushing the clamp against the rod such that the clamp snap-fits around the rod, thereby trapping the suture(s) between the clamp and the rod. In preferred aspects, a suture pair is clamped together, however, in alternate preferred aspects, the clamp and rod are simply secured to a single suture strand. In those preferred aspects of the invention in which a pair of sutures are used, the suture pair is trapped between the rod and the clamp as the clamp is snap-fit around the rod.  
       [0006] In various aspects, the rod is tubular in shape, and the clamp is dimensioned to be snap or press fit around a portion of the circumference of the rod. In optional preferred aspects, the portion of the circumference of the rod encircled by the C-section of the clamp is greater than 180 degrees such that the C-section of the clamp “latches” firmly around the rod. In various exemplary embodiments the portion of the circumference of the rod encircled by the C-section of the clamp is greater than 200 degrees, or more preferably 220 degrees, or more preferably 230 degrees or more preferably 240 degrees.  
       [0007] The present system may further include an applicator which positions the clamping system, and which forces the clamping system into a closed position in which the clamp is snap-fit around the rod. Optionally, the applicator may comprise a pair of pincers which are dimensioned to hold the rod and clamp therebetween.  
       [0008] The present invention may be used so as to completely avoid manual suture knot tying. Therefore, it also avoids the bulky multiple loops or “throws” required when knot tying. Instead, with the present system, the suture(s) is simply “clamped” together between the rod and the clamp. Thus, the present invention saves valuable time, and can be operated in very small spaces with limited surgical access, and does not require the long lengths of suture which are otherwise needed for manual knot tying.  
       [0009] The present clamping system can be positioned directly adjacent to the operative site at which it is desirable to secure the suture(s). Thus, the present applicator can be used to fasten together a suture pair right at the operative site. Therefore, the present system may be used so that it does not pull suture at the surgical site when the suture(s) are clamped or secured together. Rather, as the present system is deployed, it simply closes to lock together the suture(s) at the operative site. Therefore, the present system can easily be positioned right up against the operative site. In contrast, knot tying 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.  
       [0010] Thus, the present invention provides a rapid, easy to operate, system to secure a suture pair together, or to clasp onto a single strand of suture. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0011]FIG. 1A is a side elevation view of a first aspect of the present invention in an open position.  
     [0012]FIG. 1B is an exploded view corresponding to FIG. 1A.  
     [0013]FIG. 2 is a side elevation view of a first aspect of the present invention in a closed position.  
     [0014]FIG. 3A is a front elevation view of the present invention in an open position.  
     [0015]FIG. 3B is an exploded view corresponding to FIG. 3A.  
     [0016]FIG. 4 is a front elevation view of the present invention in a closed position.  
     [0017]FIG. 5 is a perspective view of the distal end of an applicator adapted to hold the system of FIGS.  1  to  4 .  
     [0018]FIG. 6 is a side elevation view corresponding to FIG. 5, with the rod and clamp in an open position.  
     [0019]FIG. 7 is a side elevation view corresponding to FIG. 5, with the rod and clamp in a closed position.  
     [0020]FIG. 8 is a perspective view of a second embodiment of the present invention.  
     [0021]FIG. 9 is a top plan view of the embodiment of FIG. 8.  
     [0022]FIG. 10 is a perspective view of a third embodiment of the present invention.  
     [0023]FIG. 11 is a perspective view of the present system securing tissues together using only a single strand of suture.  
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS  
     [0024] The present invention provides a suture clamping system which is fast and easy to use, and avoids the need for knot tying. FIGS.  1  to  7  show a first (two-part) embodiment of the invention comprising a separate rod and clamp. FIGS. 8 and 9 show a second (one-part) embodiment of the invention comprising a structure folded back on itself. FIG. 9 shows a third embodiment of the invention comprising a fused rod and clamp portion. The various embodiments of the invention provide a structure that clamps a length of suture or a suture pair between two portions of the structure. The portions of the structure generally include a tube and a rod.  
     [0025] Referring first to FIGS. 1A and 1B, a two part suture clamping assembly  10  is provided. Clamping assembly  10  includes a rod  20  and a clamp  30 . Clamp  30  has a first end  32 , a second end  34  and a bendable mid-section  36 . Preferably, a notch  35  is provided in second end  34 . As shown in FIG. 1B, rod  20  has a narrow end  22  which is dimensioned to be received into bore  33  in end  32  of clamp  30 .  
     [0026] In accordance with a preferred method of operation, one or more sutures  50  (e.g.: a suture pair) is preferably received into notch  35 , such that it passes between rod  20  and clamp  30 . Thereafter, clamping assembly  10  is “closed” (i.e. “deployed”) with end  34  of clamp  30  being snap-fit around rod  20 . Thus, suture pair  50  is clamped together as the suture pair is effectively trapped between rod  20  and end  34  of clamp  30 . Specifically, to move assembly  10  from an “open” position (FIG. 1A) to a “closed” position (FIG. 2), a pinching force F is applied, which simply pinches together rod  20  and end  34  of clamp  30 .  
     [0027] As can be seen in FIGS. 3A to  4 , end  34  has a C-shaped cross section, which is snap-fit around rod  20 . Rod  20  and clamp  30  are each preferably dimensioned such that an interference fit is created therebetween which compresses suture  50  between rod  20  and clamp  30 . The compressive force aids in holding the suture in place. Alternatively, rod and clamp may be dimensioned to be line-to-line fit and the suture material provides the interference. Another alternative is that the rod and clamp may be dimensioned to have a small space or gap that is slightly smaller than the intended suture size to have adequate compression.  
     [0028] In optional aspects, rod  20  and clamp  30  are made of biocompatible steel, plastic or a shape memory metal such as Nitinol™. Rod  20  may optionally have a roughened surface  21  (FIG. 1B) to increase the sliding friction against suture pair  50 . Surface  21  may be roughened by a variety of techniques, including sandblasting, filing, knurling and chemical etching.  
     [0029] Preferably, assembly  10  is sized approximately for the intended suture size. Preferably, assembly  10  has an outer diameter of approximately 0.032″ to secure 7-0 polypropylene sutures. Preferably, assembly  10  has a length of not more than 0.12″ and most preferably, not more than about 0.18″. When the assembly is embodied in such a small size, it can be positioned directly adjacent to the surgical operative site. Alternatively, the assembly may be sized for use with suture in the range of 8-0 to 3-0. In addition, the material of the suture may be polypropylene monofilamenrt, braided Dacron/nylon or similar suture.  
     [0030] Due to its very small size, in accordance with the present invention, an optional applicator is provided. Referring to FIGS.  5  to  7 , applicator  50  comprises a “pinching” device having prongs  52  and  54 . As shown in Figs. prong  52  preferably has a recess  53  into which end  32  of assembly  10  is received. Prong  54  preferably has a stub (e.g.: an overhang)  55  at its distal end.  
     [0031] As shown in FIG. 6, assembly  10  is first held in its open position between prong  52  and  54 . At this time, a suture pair  50  is positioned in notch  35  between end  34  of clamp  30  and rod  20 . As is shown in FIG. 7, a force F is then applied, pinching together prongs  52  and  54 , thereby pushing clamp end  34  into a snap-fit position over rod  20 . Thus, suture pair  50  is clamped into position between clamp end  43  and rod  20 . Thereafter, prongs  52  and  54  can again be opened (to the position shown in FIG. 6). At this time, assembly  10  remain firmly clamped around suture pair  50 . Thus, assembly  10  can easily be removed from recess  53  of applier  50 .  
     [0032] A second embodiment of the present invention is shown in FIGS. 8 and 9. This embodiment is similar in function to the first embodiment, however, it is instead formed from a single block of material, as follows. Clamp  60  is formed with a tubular end  62 , an opposite end  64  (having a C-shaped cross-section) and a thin bendable mid-section  66 . Alternatively, the different sections of clamp  60  can be separate pieces which are joined together. In this case, the separate pieces can be made of different materials. In accordance with this embodiment of the present invention, clamp  60  is folded over upon itself (folding end  62  in direction D) such that end  62  is snap-fit into end  64 . Thus, a suture pair (not shown) can be held together between ends  62  and  64  (similar to the manner in which suture pair  50  is held between rod  20  and clamp  30  in the first embodiment). Preferably, a notch  65  is cut into end  64  such that a single suture or suture pair (not shown) can more easily be positioned therein prior to end  62  being snap-fit into end  64 .  
     [0033] An optional third embodiment is shown in FIG. 10 in which clamping assembly  70  is provided. Assembly  70  comprises a rod portion  72 , a C-shaped cross-sectional clamp portion  74  and a bendable member  76  separating them. In preferred aspects, assembly  70  is formed from a single block of material, but it may also be formed from two blocks of material fused or adhesively held together. Assembly  70  operates similar to the first and second embodiments of the invention. Specifically, when a pinching force F is applied, clamp portion  74  is snap-fit into position around rod portion  72  such that a suture pair (not shown) can be trapped therebetween.  
     [0034]FIG. 11 illustrates using the present system to secure two tissues together using only a single strand of suture, as follows. A single suture  50  is threaded through tissues T 1  and T 2 . A first clamping assembly  10 A is clamped onto suture  50  right next to tissue T 1  and a second clamping assembly  10 B is clamped onto suture  50  right next to tissue T 2 . Thus, tissues T 1  and T 2  are secured together using only a single strand of suture  50 . In other aspects of the present invention, (e.g.: as illustrated in FIGS. 1A, 6 and  7 ) a single clamping assembly  10  may be used to secure a pair of sutures  50  together. Thus, it is to be understood that the present system may be used to clamp around a single suture or a suture pair. Moreover, in the case of a suture pair, such suture pair may comprises two separate strands of suture or opposite ends of a single strand of suture, as desired.