Abstract:
A surgical fastener that has an urging part and a piercing part. The urging part is formed to urge the piercing part to move between open and closed positions. The piercing part includes a pair of piercing prongs that terminate at tips, which taper into a sharpened condition to pierce through skin tissue under manual force. The piercing prongs each having a different radius of curvature so that the tips overlap each other as the piercing part reaches the closed position and that spread apart from each other as the piercing part reaches the open position. At least one of the urging part and the piercing part including a mechanism that tends to urge the tips of the piercing prongs closer to each other as the piercing part moves to the closed position from the open position.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to external skin wound fasteners that are employed for rapid closure of skin wounds by bringing sides of the wound into apposition. Apposition is a layered formation of superficial and deep soft tissues beginning at the skin surface. Hard tissue as cartilage, bone, enamel, dentin, and cementum may lie beneath the apposition and thus can benefit by being stabilized by fasteners securing the tissue above. The fasteners may be clips, clasps or uniters. 
     2. Description of Related Art 
     Skin wounds may be closed with surgical fasteners (clips and skin staples), sutures, Ethicon dermabond, or Gecko-inspired surgical tape. 
     Skin wounds of shallow depths (3.9 mm) are closed by skin staples, but cannot close deep wounds. Deep wounds are closed now with sutures in layers and only the surface is stapled with staples. 
     Ethicon dermabond is a skin bond glue—liquid that hardens in contact useful only for small tension free cuts (such as for children who are afraid of needles). Gecko-inspired surgical tape is made of a biodegradable elastic polymer and is suitable to patch wounds in organs such as the liver or heart. 
     Surgical fasteners (including clips and staples) and mentioned in U.S. Pat. No. 5,618,311 permit the surgeon to rapidly close a wound with a mechanical fastener, which holds the tissue together while the wound heals. These present day surgical fasteners however reach only to shallow depths and cannot appose bulky tissue masses. Both metallic and non-metallic fasteners are in common use. Some of the non-metallic fasteners are formed from bio-absorbable resinous materials such as blends of lactic acid/glycolide copolymer. Plastic materials of this type are widely known and commercially available under the trade names of “POLYSORB” and “LACTOMER” plastic. Typically fasteners made from these materials lose a substantial portion of their tensile strength after a few weeks of exposure to human tissue. After deployment in a mammalian body, the fasteners fragment and the pieces are metabolized by the body and therefore dissolve over time. 
     According to U.S. Pat. No. 5,618,311, the principal advantage of surgical stapling is the speed with which a wound or incision can be closed. However, in certain surgical procedures it is desirable to close the skin wound with sutures lying completely in the dermis layer. This form of subcuticular suturing minimizes the occurrence of visible scarring. However, such subcuticular suturing is very tedious and is very time consuming to perform. Surgical staplers and clips are not available for performing this type of closure. 
     U.S. Pat. No. 5,618,311 proposed a biodegradable surgical fastener having noninterlockable members. The fastener comprises a first arm and a second arm integrally interconnected to each other. Each arm has a distal prong such that each of the distal prongs are directed toward the other arm. Also proposed is a surgical fastener applicator for applying surgical fasteners having arms each with a prong. This staple-gun like applicator extrudes the biodegradable fastener horizontally to stay parallel to the skin surface in the dermis of the skin, and it is thus not meant to appose in vertically made deep tissue wounds. 
     Such an applicator comprises a fixed handle, a movable applicator lever mounted for motion with respect to said fixed handle, an applicator nose mounted to the fixed handle for storing a plurality of the fasteners and for positioning a fastener at the distal end of the applicator nose, spreader pins located proximate the applicator nose and contacting the fastener, and means connected to the spreader pins and the applicator lever for translating the movement of the applicator lever to the spreader pins. As the applicator lever is actuated, for example, when it is moved into the fixed handle, the spreader pins first apply pressure on the arms to spread apart the prongs of the fastener and subsequently release the pressure on the arms to allow the prongs to approach each other. The applicator can further have squeezer jaws located proximate the applicator nose and coupled to the movable applicator lever so that motion is translated from the applicator lever to the squeezer jaws when the applicator lever is actuated, for example, when the lever is moved into the handle. The squeezer jaws first open to allow the prongs to be spread apart by the spreader pins and subsequently close to apply pressure on the arms to bring the prongs of said fastener together after the spreader pins release the pressure on the arms to allow the prongs to approach each other. 
     It is desired to provide a surgical fastener suited for closing, at a rapid rate, deep wounds. It is further desired that such a surgical fastener be quickly removed when desired to do so. It is desired to not only close in the dermis, but for deeper wounds, to close fascia and muscle layers all at once if need be. 
     SUMMARY OF THE INVENTION 
     One aspect of the present invention relates to external skin wound fasteners that are employed for rapid closure of skin wounds by bringing sides of the wound into apposition. Skin and deeper layers, such as fascia and muscle layers, can be apposed with larger sized fasteners all in one action in accordance with the invention. The fasteners may be clips, clasps or uniters. 
     Another aspect of the invention resides in a surgical fastener that has an urging part and a piercing part. The urging part is formed to urge the piercing part to move between open and closed positions. The piercing part includes a pair of piercing prongs that terminate at tips, which taper into a sharpened condition to pierce through skin tissue under manual force. The piercing prongs each having a different radius of curvature so that the tips overlap each other as the piercing part reaches the closed position and that spread apart from each other as the piercing part reaches the open position. At least one of the urging part and the piercing part including a mechanism that tends to urge the tips of the piercing prongs closer to each other as the piercing part moves to the closed position from the open position. 
     The tips of the piercing prongs may be magnetically attracted to each other. The piercing prongs may expand in response to exposure to skin temperature. 
     A further aspect of the invention resides in a surgical fastener suited for closing, at a rapid rate, deep wounds in the dermis layer and those deeper than the dermis layer and be quickly removed when desired to do so. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
       For a better understanding of the present invention, reference is made to the following description and accompanying drawing, while the scope of the invention is set forth in the appended claims. 
         FIG. 1  shows a schematic diagram of a would neighboring the eye in a taut condition due to a grasping force from a surgical tool as the wound is being closed with surgical fasteners in accordance with the invention. Forceps position the surgical fastener appropriately with distal ends of the forceps fitted into accommodating grooves at ends of handles of a surgical fastener. 
         FIG. 2  shows a schematic diagram of the surgical fastener of  FIG. 1  but close-up and with a different surgical tool grasping s wall of the wound to render the wound taut as the wound is being closed with surgical fasteners in accordance with the invention. Large wounds can be held taut and made to stay approximated with fingers alone holding the two edges together to “feed” the wound line to the fastener. 
         FIG. 3  shows a schematic view of a plurality of surgical fasteners in position closing a wound neighboring the eye, with an inset cut-away view showing an exemplary one of the surgical fasteners in a cut-away view closing the wound. 
         FIG. 4  shows a small-size surgical fastener in accordance with the invention, but with a sterile package enclosing the handles and with grooves in the handle ends for accommodating placement of distal ends of forceps in the manner of  FIG. 1 . 
         FIG. 5  shows an isometric view of the small-size surgical fastener of  FIG. 4  outside the packaging. 
         FIG. 6  shows an enlargement of a distal end of a handle within the circled portion of  FIG. 5  to show the groove to accommodate a distal end of forceps. 
         FIG. 7  shows a large-size surgical fastener in accordance with the invention being position to close a wound. 
         FIG. 8  shows the similar view to that of  FIG. 7 , except that a torsion spring is provided. 
         FIG. 9  shows a schematic elevation view of a further embodiment of a fastener with telescoping piercing arms that project from left and right side fastener arms. 
         FIG. 10  shows a schematic top view of a left side fastener arm of  FIG. 9 . 
         FIG. 11  shows a schematic top view of a right side fastener arm of  FIG. 9 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Unlike suturing, which requires a surgical tray and skilled medical personnel in operating room or emergency room setting, the present invention offers an alternative based on the use of sterile packaged fasteners in various sizes instead. The various sizes are suited for various depths of wounds. Such renders them available to surgeons of many specialties in the operating rooms, emergency rooms and nursing outposts in emergency medical service ambulances. Soldiers may carry them in their backpacks on the battlefield to clasp closed their bleeding wounds immediately when laceration occurs, thereby stopping the loss of blood right away. 
     Turning to  FIG. 1  the surgical fastener  10  is held by forceps  20 , while a surgical hook  30  holds open a wound  40  to be closed by a series of the surgical fasteners  10  in the vicinity of an eye  50 .  FIG. 2  shows a similar view as in  FIG. 1 , except that a surgical hook  32  is used to open a large wound  41 . 
     The purpose for using the surgical fastener  10  is so that lips of he wound would be brought to stay apposed with one pinching motion. The action would close the skin wound quickly as these surgical fasteners  10  would be placed one after another in quick succession at intervals so as to have the closure along the full length of the wound in no time (See  FIG. 3 ). 
     Turing to  FIGS. 4-6 , the surgical fastener  10  is a clasp having external handles  12  (external urging part) each with a groove  13  and a pair of piercing prongs  14  (internal penetrating part or piercing part), a pivot bar  16 , and a torsion spring  18 . By engaging distal ends of the forceps  20  of  FIGS. 1 and 2  into complementary ones of the groves  13  ( FIGS. 4 and 6 ) at the end of the handles  12  and squeezing the forceps  20  ( FIGS. 1 and 2 ) to close, the torsion spring  18  ( FIGS. 4 and 5 ) compresses to open the clasp and thus spread apart the piercing prongs  14 . The distal tips of the piercing prongs  14  may be properly positioned relative to the opposite edges of the wound  40  ( FIGS. 1 and 2 ) so that opening the forceps decompresses the spring to enable the piercing prongs  14  to be urged to pierce (penetrate or otherwise enter) from the opposite sides of the wound through the skin. These piercing prongs  14  overlap in deeper parts of the wound apposing the wound sides one to he other as the spring compression would be let go. 
     The fasteners may come in various sizes. That is, tiny for shallow wounds as those found on the skin of the eyelids to grades of ever larger ones for very deep gushing wounds. For deep wounds, it wound be possible to make two-tier vertically aligned prongs. The tips of the piercing prongs  14  are needle sharp for passing into tissues with ease and thus taper to their distal ends. The piercing prongs  14  may be made of stainless steel or other metals or other tissue compatible materials such as silicone rigid plastic. 
     Turning to  FIGS. 7 and 8 , larger size surgical fasteners  11 ,  15  are picked up and held by fingers to urge the piercing prongs  14  to penetrate the skin to close the wound  40 . In the case of  FIG. 8 , the torsion spring  18  is compressed by squeezing together the handles  12 . The wounds sides are held in apposition by the force of the torsion spring  18  and by the sharpness of tips of the piercing prongs  14 . 
     The surgical fasteners  10 ,  11  are in a variety of different widths. The dimensions for the different widths are dependent upon the number of prongs of the surgical fastener:  1  prong,  2  prongs,  3  prongs,  4  prongs, n prongs. 
     Removal of the surgical fasteners  10 ,  11  is easy. Just pinch a “collar” (squeeze together handles  12 ) to compress the spring, which causes the piercing prongs  14  to open up and retract out of the healed wound. 
     The spring  18  does not have to be the sole force or mechanism to keep sides of the wound together and may be dispensed with altogether ( FIG. 7 ). The distal end of the clasps may be magnetic so that a magnetic attractive force would help keep the sides of the wound together. The clasp itself may exert a force tending to keep its prongs in a closed position upon the attainment of certain modalities such as temperature. For instance, the piercing prongs  14  may be made of a metal material that expands when exposed to the elevated temperature of a persons skin temperature at the wound from an unexpanded state at room temperature to generate a force tending to keep sides of the wound together. 
     Another variant is shown in  FIG. 9 . The two piercing prongs  14  each telescope in a sense from an associated one of the two fastener legs to overlap each other in the fully extended position of  FIG. 9 . Each of the piercing prongs spring bias to be urged, upon release, from a retracted position to the fully extended position. 
     In the retraced position, spring biased pins  66  project through a proximal opening  60  in one outward wall  68  of associated fastener legs. This spring biased pins  66  may taper into the proximate opening  60  such that only the tip can project through. The wider part of the taper is too wide to fit into the proximal opening  60 . At the end of the pin opposite from the taper of the pin  66  is a respective spring, which acts against a companion outward wall  70  (spaced from the outward wall  68 ). Each fastener leg has its own pair of outward walls  68 ,  70  that are essentially parallel with each other. 
     In order for the piercing prongs to move from the retracted position to the fully extended position, catches (pins  66 ) are released to allow springs  76  to decompress to urge the piercing prongs  14  ( FIG. 9 ) to move in the direction of arrows  72  ( FIGS. 9-11 ). To release the catches, projecting tapered ends  80  ( FIGS. 10 ,  11 ) of the pins  66  are manually pressed into the proximal openings  60  to clear them. This allows an associated compressed spring  76  ( FIGS. 10 ,  11 ), which is secured to an associated support bar  74  ( FIGS. 10 ,  11 ), to decompress to urge the piercing prongs  14  ( FIG. 9 ) to move to the fully extended position while the pins  66  are being guided along tracks  62 . The tracks  62  are aligned with each other in both outward walls  68 ,  70  of associated fastener legs. 
     At the fully extended position, the tapered ends  80  ( FIGS. 10 ,  11 ) of the pins  66  bias into associated distal openings  64  just as they did for the proximal openings  60 . This effectively locks the piercing prong into its fully extended position. Thus, the piercing prongs  14  travel in the direction of the double arrows  72  ( FIGS. 9-11 ) to reach the fully extended position from the retracted position. 
     The spring bias of springs  76  that urge the piercing prongs  14  to move from the retracted to the fully extended position is advantageous by providing in effect a stronger push in close proximity to where the piercing prongs are to overlap each other in the fully extended position. Thus, one would initially push the piercing prongs as far as practical into the skin walls on either side of the wound while the piercing prongs are in the retracted position. For instance, as the distal ends of the fastener arms become adjacent the skin, the piercing prongs  14  cannot be further inserted under manual force. At that point of advance, the pins  66  need to be manually pushed in to allow a spring to decompress to urge the piercing prongs to advance further reach their fully extended positions. The sides of the wound should appose each other. 
       FIG. 10  represents schematically the left side fastener arm of  FIG. 9 . The left side fastener arm of  FIG. 10  is symmetric to the right side fastener arm of  FIG. 11 . The tracks  62  ( FIG. 9 ) are recesses in the walls  68 ,  70  of  FIGS. 10 ,  11  that extend the same length, although not shown in those views. 
     The springs  76  of  FIGS. 10 ,  11  are shown in a decompressed condition, but their compressed condition can be understood when the pins  66  align with the opening  60  such that the tapered ends  80  project through. The springs  76  compress between their associated support bar  74  and the associated pin  66 . 
     The walls  68 ,  70  may be joined to each other at each fastener leg by top and bottom surfaces (not shown, but which may extend the full distance of the walls  68 ,  70  to form a rectangular, tubular shape with the walls  68 ,  70 ). Movement of the piercing prongs from the retracted position to the extended position appears to telescope from the associated fastener leg. 
     Removal of the fastener is straightforward. By squeezing the handles  12  toward each other, the fastener legs spread apart, which enables the piercing prongs  14  to be thereafter manually pulled out by pulling out the fastener. 
     Spring loaded prongs: initially, the prongs would be partially retracted into a sleeve housing a compressed spring. The upper part of the prong would be attached to the spring. A button would be triggered or a pin would be pushed out to release the spring and, as the spring expanded, it would drive the prongs forcefully into fascia. 
     While the foregoing description and drawings represent the preferred embodiments of the present invention, various changes and modifications may be made without departing from the scope of the present invention.