Abstract:
A surgical pledget assembly includes a pledget body having first and second apertures extending through the body, one or more snares passing through the apertures in the pledget body and including first and second suture engaging loops disposed on a distal side of the pledget, an optional third folding loop disposed on a proximal side of the pledget, and a handle secured to the ends of the snare or snares proximal to the pledget.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     None 
     BACKGROUND OF THE INVENTION 
     This invention relates generally to surgical suturing and more particularly to a device for remotely placing a surgical pledget at a suturing site and drawing suture tails through the pledget to be secured proximally of the pledget. 
     DESCRIPTION OF RELATED ART 
     The general medical definition of a pledget is a small compress, tuft, or flat mass usually made of gauze or absorbent cotton that is laid over a wound or into a cavity to apply medication, exclude air, retain dressings or absorb discharged matter. The pledget concept, in a more specifically surgical application, often applies to material or bolster used to help reduce the risk of suture pulling through tissue that it is holding by cushioning and spreading the load of the suture against the underlying tissue. Surgical pledgets have been used throughout history and remain a routinely utilized adjunct to suture mediated tissue repair even in the most advanced modern surgical procedures. 
     In addition to pledgets distributing the retaining force of the suture over a larger area of tissue, they can aid in minimizing the leakage of bodily fluids, such as blood, that results from penetration of bodily tissue by a suture needle and suture. Pledgets may be left implanted permanently at a wound closure site or a prosthetic attachment site. If indicated, they can also be subsequently removed along with the sutures from the patient. 
     A pledget may be placed completely under a section of suture or it can be configured so that the suture passes through one or more sections of the substance or the body of the pledget itself. A pledget also may be placed before or after the suture has been passed through tissue. By passing the suture through the pledget, the suture and the pledget can be more conveniently and securely handled during the suture placement process. While a pledget could be placed under the suture and above the tissue without the suture traversing through the pledget, this is often not practical or reliable under certain surgical conditions, especially those involving the remote suturing as are needed in many minimally invasive surgical procedures. 
     Furthermore, a pledget not threaded with a suture is more readily dislodged during manipulation or by movement or change of shape (e.g., swelling resolution) of the tissue. 
     Pledget Description. Pledgets are usually small pieces of thin, relatively soft material intended to atraumatically distribute the suture compressional forces over a broad area. They are conventionally formed from biocompatible flexible materials such as foam, felt or fabric. Pledgets are often made from non-resorbable polyurethane, polyamide, polyethylene, polypropylene, polyethylene terephthalate, polytetrafluoroethylene (PTFE or Teflon®), or various absorbable polymers, such as polyglycolic acid or even pieces of autologous tissue. These materials are selected based on surgical judgment to offer sufficiently enhanced structural integrity to assure that after the suture is tied, the pledget is held securely but gently against the tissue surrounding the suture to prevent tearing of the suture through the tissue and to reduce or prevent bleeding at suture puncture wounds. Common pledgets are conventionally formed from flat cloth-like material and are usually configured in circular, oval or rectangular shapes. Pledgets can be supplied as loose individual pieces with or without preformed suture holes extending through full thickness of the pledget, with preformed specialized suture entrance slits to accommodate alternative methods of placement with suture as described for example in U.S. Pat. No. 4,823,794 or as sets of multiple connected pledgets as described, for example, in U.S. Pat. No. 5,733,308) or pre-loaded on sutures with needles (e.g., Gore-Tex TH-22 {Flagstaff, Ariz.} or Covidien 3336-51 {Mansfield, Mass.}). Pledgets not preloaded on suture are also commercially available (e.g., Ethicon PCP20 {Somerville, N.J.}, TFE Polymer Pledgets (Firm)) with or without pre-formed holes through the body of the pledget just large enough to accommodate a suture of the desired size. 
     Suturing with Pledgets. Pledgets are usually used when more than one tissue bite is performed with one suture. A single loop suture, called a simple interrupted suture, does not typically require a pledget since a single loop going through two edges of a wound would have only a pledget on top of the wound. When more than one tissue bite is required, it is more practical to use pledgets under the sections of suture not passing through the tissue. For example, a so-called double armed suture with a needle at each end and with a pledget on the suture between the needles can be used to provide a pledget located on top of the tissue between the tissue entrance holes of the needles at the side opposite from where the knot will be placed (Reed and Cortez, “Measured Tricuspid Annuloplasty: A Rapid and Reproducible Technique”, Annals of Thoracic Surgery, Vol. 21, February 1976, pp. 168-169.) After the needles have exited the tissue site, by passing these two needles through a second pledget, this second pledget is located on the knot side of the closure on the top of the tissue between the needle exit sites. For conventional hand-tied knots, both needles would typically then be cut off from the suture and the hand-tied knotting process would commence over the second pledget near the needles exit site. Tightening the suture draws the two pledgets together and holds the tissue in compression. 
     Alternative Suturing and Knotting Techniques. Alternative techniques of suture placement, especially those used with mechanically assisted suturing devices, often provide two suture ends left untied on one side of the wound closure site or a prosthetic attachment site (U.S. Pat. Nos. 6,997,931; 7,731,727; U.S. application Ser. No. 12/835,464). For automated mechanical knots, it would further be helpful to not only pass the suture through the pledget but to continue to pass the same suture ends through the mechanical knot. The use of a single loop wire snare to pull suture ends through a mechanical knot (U.S. Pat. Nos. 5,520,702; 5,643,289; 5,669,917; 6,368,334; 6,641,592; 7,235,086) is currently commercially available through the Titanium Knot® Quick Load® unit and the Cor-Knot™ Quick Load® unit for the TK and CK device products, respectively, from our company, LSI SOLUTIONS®, Victor, N.Y. This single loop suture snare approach is easily and quickly learned by surgeons; it has been successfully employed to help secure suture in thousands of patients throughout this country. 
     The use of pledgets with surgical suturing confers many compelling advantages, but placement of a pledget on the suture ends at the knot side of the suture still presents inconvenient challenges and unnecessary risks. A pledget preloaded onto a suture, either through the use of needles or passing suture ends through pre-placed holes in the pledget, provides more definitive capture of the pledget. 
     Prior to this invention, the requisite use of needles to pass suture through pledgets would require several extra steps, increase the risk of needle injury and infection, and may not prove possible in many modern surgical interventions. While reducing the risk to the surgical team of unnecessary needle exposure is critical, the advantages of pledgets for the patient should not be sacrificed because of the difficulties of hand threading the suture through the pledgets. Hand threading suture ends through tiny holes in pledgets is not practical and may not even be achievable in the diminished ambient light conditions of many video intensive operating rooms. Custom slotted pledgets can offer some benefits, but may not satisfy the requirements for ease-of-use, effectiveness and safety in minimally invasive surgery applications, especially those involving automated suturing or automated knot placement technologies. The currently marketed single loop wire snare devices now available for pulling suture through mechanical knots do not aid in the placement of suture through pledgets. Devices to reduce the dexterity requirements and complexity of modern surgical operations can decrease anesthesia and surgery durations and potentially improve patient outcomes. A surgeon should have the option for the expedited use of enhancements, like pledgets, based on clinical needs without concerns regarding reliability or excessive time expenditures. The present invention addresses these needs. 
     BRIEF SUMMARY OF THE INVENTION 
     Briefly stated and in accordance with an embodiment of the invention, surgical pledget assembly includes a pledget body having first and second apertures extending through the body, one or more snares passing through the apertures in the pledget body and including first and second suture engaging loops disposed on a distal side of the pledget, an optional third folding loop disposed on a proximal side of the pledget, and a handle secured to the ends of the snare or snares proximal to the pledget. 
     In accordance with another embodiment of the invention, a suturing sleeve is disposed on the snare between the handle and the proximal side of the pledget. 
     In accordance with yet another aspect of the invention, the handle comprises a hollow sleeve. 
     In accordance with another aspect of the invention, the handle is crimped to the ends of the snare. 
     In accordance with yet another aspect of the invention, the snare ends are twisted together. 
     In accordance with still another aspect of the invention, the handle is curved to make it easier to grasp. 
     In accordance with a further aspect of the invention, the snare includes suture engaging loops of different sizes. 
     In accordance with a still further aspect of the invention, the suturing sleeve includes an enlarged head and a crimpable body. 
     In accordance with another aspect of the invention, a method for drawing first and second suture tails through first and second apertures of a surgical pledget includes the steps of providing a surgical pledget having first and second apertures formed therein or a snare or snares formed into first and second suture engaging loops disposed distally of a pledget and an optional folding loop where the snare is a single piece, and first and second snare ends disposed proximally of a pledget; and passing the first and second suture tails through the first and second suture engaging loops respectfully; and then drawing the snare and the suture tails proximally through the pledget apertures by pulling the snare ends proximally until the snare is released from the pledget and the suture tails pass through the pledget apertures. 
     In accordance with another aspect of the invention, the method includes the step of securing the suture tails together on the proximal side of the pledget to close a wound for example. 
     In accordance with yet another aspect of the invention, securing the suture tails includes the step of securing the tails with a crimpable sleeve. 
     In accordance with yet another aspect of the invention, the method includes the step of passing the snare ends through a suture securing sleeve before drawing the snare ends and the suture tails proximally through the pledget and drawing the suture tails through the sleeve. 
     In accordance with a favored embodiment of the invention, the suture tails are crimped in the suture securing sleeve. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S) 
       While the novel aspects of the invention will be described with particularity in the appended claims, the invention itself together with further objects and advantages thereof may be more readily understood by reference to the following detailed description of the number presently preferred embodiments of the invention taken in conjunction with the accompanying drawings in which: 
         FIG. 1  is a distally oriented perspective view of a surgical pledget assembly in accordance with this invention as presented for use; 
         FIG. 2  is a proximally oriented perspective view of the pledget assembly of  FIG. 1  as presented for use; 
         FIG. 3  is a perspective view of the pledget assembly presented in  FIG. 1  in preparation for use in a corresponding application instrument when applied to its field of use; 
         FIG. 4  is a perspective view of the distal end of the pledget assembly and corresponding application instrument presented in  FIG. 3  as applied to its intended field of use; 
         FIG. 5  is a proximal perspective view of the pledget assembly accepting suture tails from a wound site; 
         FIG. 6  is a proximal perspective view of the pledget assembly of  FIG. 5  illustrating the initial passing of suture through the device; 
         FIG. 7  is a proximal perspective view of the pledget assembly of  FIG. 6  illustrating the final stage of progression of the suture through the device; 
         FIG. 8  is a proximal perspective view of the pledget assembly of  FIG. 7  demonstrating the suture completely passed through the device; 
         FIG. 9  is a proximal perspective view of the pledget assembly of  FIG. 8  pressed against the wound site and closing the wound area via the tension of the suture; 
         FIG. 10  is a perspective view of the closed wound with applied suture securing sleeve; 
         FIG. 11  is an exploded perspective view detailing a representative sequential step in the assembly of the pledget assembly of this invention; 
         FIG. 12  is a perspective view of the pledget assembly disclosed in  FIG. 11 ; 
         FIG. 13  is a perspective view illustrating the initialization of the forming process for the pledget assembly of  FIG. 12 ; 
         FIG. 14  is a perspective view of the formed pledget assembly of  FIG. 13 ; 
         FIG. 15  is an exploded perspective view of an additionally formed and adapted pledget assembly of  FIG. 14 ; 
         FIG. 16  is a perspective view illustrating partial assembly of the pledget assembly illustrated in  FIG. 15 ; 
         FIG. 17  is a perspective view of an embodiment of a pledget assembly in accordance with this invention illustrating a variation of the installed ends of the wire snare; 
         FIG. 18  is a perspective view of an embodiment of a pledget assembly in accordance with this invention wherein two separate wire snare loops are passed individually through a pledget. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIGS. 1 and 2 , a presently preferred embodiment of the invention is disclosed. 
       FIG. 1  shows a distal view of a dual snare pledget assembly  10  as presented for use. A large loop  46  and a small loop  45  having passed through and expanded outside of suture holes  52  formed in a pledget  50  in a fashion that allows for the positioning of the pledget  50  in proximity to a suture securing sleeve  30 . While  FIGS. 1-17  illustrate embodiments of the invention in which the large and small loops are formed from a single length of material, the loops may be formed separately as shown in  FIG. 18 . 
       FIG. 2  shows a proximal perspective view of the dual snare pledget assembly  10  of  FIG. 1  relative to its intended field of use with the pledget  50  in position close to a head  32  of the suture securing sleeve  30 . A folding loop  47  of a wire snare  40  transits the two suture holes  52  of the pledget  50 . 
       FIG. 3  is a perspective view of the dual snare pledget assembly  10  with its preferred method of application in a mechanical crimping device  60 . The mechanical crimping device  60  is preferably a commercially available product such as the TK Ti-Knot® Device™, or CK Cor-Knot™ Device™ which are marketed exclusively by LSI SOLUTIONS®, Inc. The curved handle  20  of the dual snare pledget assembly  10  is inserted into a sleeve receptacle  61  along an insertion path  62  located at the distal end of a barrel  63  that is fixedly attached to a handle  64  of the mechanical crimping device  60 . The mechanical crimping device  60  is mechanically activated via a lever  65  which induces a physically crushing force onto the suture securing sleeve  30  leaving it permanently attached to suture tails emanating from a wound closure site. 
     Focusing on  FIG. 4 , the dual snare pledget assembly  10  is shown fully installed and securely seated in the barrel  63  of the mechanical crimping device  60  of  FIG. 3 . The curved handle  20  is passed through and protruding from the barrel  63 . While a curved handle geometry is preferred to facilitate threading of the handle through the distal end of the mechanical crimping device and to provide greater purchase for pulling on the handle to operate the device during a procedure, a straight handle may also be used, preferably provided with a textured gripping surface. 
       FIGS. 5 through 8  illustrate the sequential threading, passing, and pulling of suture  80  through the dual snare pledget assembly  10 , suture securing sleeve  30  and barrel  63  of the mechanical crimping device  60 . 
       FIG. 5  depicts opposing sections of tissue  70  with emplaced suture  80 . The suture  80  protrudes from sections of tissue  70  through suture exits  72  such that a left suture tail  82  and a right suture tail  84  remain separated from each other. The left suture tail  82  and the right suture tail  84  are directed towards the mechanical crimping device  60  of  FIG. 3  and the installed dual snare pledget assembly  10  with the small loop  45  and large loop  46 , respectively. Illustrated is the initial step wherein the left suture tail  82  is threaded through the small loop  45  and kept separated and untangled from the right suture tail  84  which is threaded through the large loop  46 . It should be noted, however, that placement of a particular suture tail in a particular loop is not critical so long as the suture  80  is kept untangled, and only one suture tail is fed into each loop. 
       FIG. 6  shows the sequence of events after  FIG. 5  wherein the curved handle  20  is extracted by hand from the barrel  63  of the mechanical crimping device  60  by pulling it in the direction  24 . The small loop  45  and large loop  46  are drawn through the suture holes  52  in the pledget  50  and begin the process of passing the left suture tail  82  and right suture tail  84  through the mechanical crimping device  60 . 
       FIG. 7  depicts the sequence of events after  FIG. 6  wherein the curved handle  20  is extracted by hand further from the barrel  63  of the mechanical crimping device  60  in the pull direction  24 . The previously passed small loop  45  and its threaded left suture tail  82 , which are no longer visible, are almost pulled entirely through the barrel  63  and the large loop  46 , which is no longer visible, and its threaded right suture tail  84  have passed through the pledget  50  and are being passed through the barrel  63 . While small and large loops are preferred to reduce the bulk of the snare as it passes through the mechanical crimping device, loops of the same size may also be used. 
       FIG. 8  illustrates the final sequence of pulling suture  80  through the pledget  50  and out of the barrel  63  of the mechanical crimping device  60 . The curved handle  20  is fully extricated from the barrel  63  in pull direction  24  which subsequently allows for the exit of the left suture tail  82  and the right suture tail  84  from the barrel  63 . 
     Referring now to  FIG. 9 , the barrel  63  of the mechanical crimping device  60  is moved along engaging direction  66  and the left suture tail  82  and the right suture tail  84  are pulled taut in direction  86  such that the pledget  50  is cinched against the tissue  70 , drawing the opposing sides towards each other in direction  74 . Tension is maintained and the mechanical crimping device  60  is actuated to secure the suture with the crimped sleeve  90  (not shown in this view). While use of a sleeve to secure the suture is preferred, the suture may also be tied in conventional fashion. 
       FIG. 10  illustrates the effect of the actuated mechanical crimping device  60  as shown in  FIG. 9  wherein the pledget  50  is snug to the tissue  70 , the suture  80  is taut, and a crimped sleeve  90  is secured against the pledget  50  with trimmed suture  88  exiting a crimped barrel  92 . 
     Referring to  FIGS. 11 and 12 , process steps are shown for a typical assembly of a pledget assembly in accordance with one aspect of the invention. 
       FIG. 11  shows a pledget assembly  10  preferably including a wire or fiber snare  40 , a suture securing sleeve  30  having an enlarged head  32 , and a curved handle  20 . The wire snare  40  is formed of a biocompatible flexible wire such as 304 stainless steel or the like, or a natural or synthetic fiber such as silk or polypropylene or the like, into a loop  41  whose free ends  42  are secured together as a twisted pair end  43 . The twisted pair end  43  of wire snare  40  is inserted through a bore  36  of suture securing sleeve  30  such that the head  32  is adjacent to the loop  41 . 
     Traditionally, the suture securing sleeve  30  is made of a medical grade permanently implantable radiopaque material; such as titanium, although absorbable materials such as magnesium can be used. Suitable suture securing sleeves  30  are exclusively marketed by LSI SOLUTIONS®, Inc, and can be found under commercial trade names Ti-Knot® and Cor-Knot™ The twisted pair end  43  is inserted into a snare receptacle bore  22  of a curved handle  20  and permanently secured by mechanically crimping the handle. While twisting the ends of the wire snare  40  is preferred, the untwisted ends may, if desired, simply be inserted through the sleeve  30  into the handle  20  and crimped. Typical materials used in the forming of the curved handle  20  include fully hardened stainless steels in the 400 series regime. 
       FIG. 12  illustrates the assembled dual snare pledget assembly  10  of  FIG. 11  before the single snare is formed into two loops. The wire snare  40  passes through the suture securing sleeve  30  and fixedly attached to the curved handle  20 . 
       FIGS. 13 through 16  illustrate the forming sequence of the wire snare  40  in accordance with an embodiment of the invention. 
       FIG. 13  depicts the dual snare pledget assembly  10  in its raw form with the loop  41  being deformed in a folding direction  44  such that the presentation of a dual loop becomes evident. 
       FIG. 14  shows a dual snare pledget assembly  10  that having been formed in folding direction  44  creates a folding loop  47  and two disparate loops of wire; a small loop  45  and a large loop  46 . 
       FIG. 15  demonstrates the additional forming of the wire snare  40  into formed points  48  to facilitate installation through suture holes  52  of the pledget  50 . The large loop  46  and the small loop  45  are mechanically pinched to temporarily create formed points  48 . 
     Referring to  FIG. 16 , the large loop  46  of the wire snare  40  has been passed through one of the suture holes  52  of the pledget  50  and expanded. The small loop  45  with its formed point  48  is shown inserted through and protruding from the opposing suture hole  52  of pledget  50 . 
       FIG. 17  shows an embodiment of the invention in which the ends  42  of the wire snare  40  are not twisted or otherwise combined, but fed individually through the suture securing sleeve  30  and into the curved handle  20  where they are mechanically secured, for example, by crimping. 
       FIG. 18  shows an embodiment of the invention wherein free ends  102  of an individual small wire loop  100  and free ends  112  of a large wire loop  110  are separately fed through the suture holes  52  of pledget  50  and subsequently through the suture securing sleeve  30  and into the curved handle  20  where they are mechanically secured. 
     While the invention has been described in connection with certain presently preferred embodiments thereof, those skilled in the art will recognize that many modifications and changes may be made therein without departing from the broad scope of the invention which accordingly is intended to be defined solely by the appended claims.