Abstract:
A mechanical device and method for gathering and securing tissue with a fastener. The device includes an applicator assembly configured to deploy a fastener in a first direction, a tissue manipulation assembly configured to move from a relaxed position to a grasping position in a second direction transverse to the first direction, and a translating trigger assembly coupled to the applicator assembly and the tissue manipulation assembly. The trigger assembly is configured to move from a relaxed position, through a first position, to a second position along a third direction transverse to the first and second direction. Operation of the trigger assembly from the relaxed position through the first position along the third direction causes the tissue manipulation assembly to move in the second direction to gather a portion of the tissue. Continued operation of the trigger assembly along the third direction causes the applicator assembly to deploy the fastener.

Description:
RELATED APPLICATIONS AND PRIORITY CLAIM  
       [0001]     The present application is a continuation-in-part application of co-pending U.S. patent application Ser. No. 10/448,838, filed May 30, 2003, entitled “Mechanical Method and Apparatus for Bilateral Tissue Fastening,” which is a divisional of U.S. patent application Ser. No. 10/179,628, filed Jun. 25, 2002, now issued as U.S. Pat. No. 6,726,705, and is also a continuation-in-part application of co-pending U.S. Continuation-In-Part application Ser. No. 10/607,497, entitled “Mechanical Method and Apparatus for Bilateral Tissue Fastening,” filed Jun. 25, 2003, and co-pending U.S. Continuation-In-Part application Ser. No. 10/603,397, entitled “Dynamic Bioabsorbable Fastener for Use in Wound Closure,” filed Jun. 25, 2003, all of which are herein incorporated by reference in their entirety. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates generally to the field of surgical instruments such as surgical staplers, clip applicators and sutureless closure devices. More particularly, the present invention relates to a mechanical method and apparatus for fastening tissue, such as skin tissue, with a fastener that secures opposed pieces of tissue and is deployed by a single translating trigger operation.  
       BACKGROUND OF THE INVENTION  
       [0003]     Biological healing of a tissue opening commences through the proximity of the opposed living tissue surfaces. If the opening is very large or if its location subjects the wound to continual movement, a physician will seek to forcibly hold the sides of the opening in close proximity so as to promote the healing process.  
         [0004]     Human skin tissue is comprised of three distinct layers of tissue. The epidermal layer, also known as the epidermis, is the outermost layer and includes non-living tissue cells. The dermal layer, or dermis, is the middle layer directly below the epidermal layer and comprises the living tissue of the skin that is the strongest of the three layers. The subcutaneous, or hypodermis layer is the bottom layer of skin tissue and includes less connective tissue making this the weakest layer of skin tissue. Healing occurs best when the opposing dermal layers of the skin tissue are held in proximity with each other.  
         [0005]     While traditional suturing remains a popular method of effectuating closure of wound openings, the use of staples and staplers as a closure technique has become increasingly popular, especially in surgical settings where the opening is created through a purposeful incision. In these settings, the incision tends to make a clean, straight cut with the opposing sides of the incision having consistent and non-jagged surfaces.  
         [0006]     Prior art methods of closing tissue using a stapler require at least two hands. For example, when stapling a skin opening, a medical professional typically uses one hand to manually approximate the opposing sides of the skin opening while another hand is used to position the stapler so that a metal staple will span the opening. The stapler is then manipulated such that the staple is driven into the skin with one leg being driven into each side of the skin and the cross-member of the staple extending across the opening external to the skin surface. Generally, the legs of a metal staple are driven into an anvil causing the metal staple to deform so as to retain the skin tissue in a compressed manner within the staple. This process can be repeated along the length of the wound opening such that the entire incision or wound is held closed during the healing process.  
         [0007]     While effective in holding an incision or wound closed, conventional metal staples unfortunately require removal after the healing process of a wound opening is completed. As the sciences of medical and materials technology have advanced over the course of the past century, new bioabsorbable polymers and copolymers have been developed that provide medical professionals with an alternative to metal staples that must be removed. Fasteners made of bioabsorbable materials, sometimes referred to as bioabsorbable or biodegradable, break down or degrade over time in the body, with the residuals being either absorbed or ultimately expelled by the body&#39;s natural processes.  
         [0008]     Bioabsorbable polymer fasteners are preferable to metal staples because they do not have to be removed. While there has been active development of dermal layer suturing techniques, little has been done in the area of staples and staplers for use in connection with the dermal layer. In a series of patents issued to Green et al., including U.S. Pat. Nos. 5,292,326, 5,389,102, 5,489,287 and 5,573,541, a subcuticular stapling method and apparatus are disclosed that were ultimately commercialized as the U.S. Surgical SQS Subcuticular Stapling Apparatus. The Green et al., patents describe a stapling technique employing a handheld apparatus with jaws to proximate, interdigitate and overlap opposing sides of dermal layer tissue along the length of a skin opening. The apparatus then drives a single spike through the interdigitated and overlapped dermal layers of the opposing skin surfaces in order to secure both sides of the dermal tissue on the single spike. The trigger assembly for this apparatus utilizes a conventional reciprocating trigger arrangement whereby the direction of squeezing action of the trigger is generally parallel to and opposite of the direction in which the spike is ejected from the fastener. Although this technique reduced the time required to effectuate a subcuticular skin closure, the SQS device was not commercially successful in part because the resulting closure produced an undesirable wave-like scar that sometimes did not heal effectively.  
         [0009]     A novel bilateral approach to fastening dermal tissue using bioabsorbable fasteners is disclosed and described in U.S. Pat. No. 6,726,705, as well as in U.S. patent applications Ser. Nos. 10/448,838, 10/607,497 and 10/603,397, to Peterson et al, all of which are commonly assigned to the assignee of the present application and all of which are incorporated by reference in their entirety. In one embodiment, this bilateral approach to tissue fastening utilizes a first apparatus to manipulate opposed sides of tissue to form target tissue zones followed by a second apparatus that effects a bilateral insertion of a tissue fastener to retain opposed dermal layers across an incision or wound in close approximation to facilitate healing. By maintaining contact of the dermal layers through the healing process, the healing process is enhanced which results in less chance of infection, faster recovery and improved aesthetic appearance. In addition, no subsequent medical follow-up is necessary to remove fasteners as is typically necessary with nonabsorbable fasteners. In this embodiment of Peterson et al., however, two medical practitioners may be required, one for operating each of the two apparatus that are utilized to accomplish bilateral capture and insertion of the bioabsorbable fastener.  
         [0010]     While the bilateral tissue fastening methods and apparatus taught by Peterson et al. provide many advantages, there are opportunities to improve upon the principles taught by Peterson et al. with respect to tissue fastening applications. For example, it would be desirable to provide for a fastening device that can be operated more effectively by a single medical practitioner with one hand to repeatedly and accurately approximate tissue while deploying staples.  
       SUMMARY OF THE INVENTION  
       [0011]     The invention includes a mechanical device and method for gathering and securing tissue with a fastener. The device includes an applicator assembly operably configured to deploy a fastener in a first direction, a tissue manipulation assembly operably configured to move from a relaxed position to a grasping position in a second direction generally transverse to the first direction, and a translating trigger assembly operably coupled to the applicator assembly and the tissue manipulation assembly. The trigger assembly is operably configured to move from a relaxed position, through a first position, to a second position along a third direction that is generally transverse to both the first direction and the second direction, such that manual operation of the translating trigger assembly from the relaxed position through the first position along the third direction causes the tissue manipulation assembly to move in the second direction to gather at least portion of the opposed tissue. Continued manual operation of the translating trigger assembly from the first position on to the second position along the third direction causes the applicator assembly to deploy the fastener into the opposed tissue along the first direction.  
         [0012]     In another embodiment, the invention includes a method for gathering and securing opposed tissue with a fastener. The method includes providing a fastener apparatus having an applicator assembly operably configured to deploy a fastener in a first direction, a tissue manipulation assembly operably configured to move from a relaxed position to a grasping position in a second direction generally transverse to the first direction, and a translating trigger assembly operably coupled to the applicator assembly and the tissue manipulation assembly. The trigger assembly is operably configured to move from a relaxed position, through a first position, to a second position along a third direction that is generally transverse to both the first direction and the second direction. The method also includes the steps of positioning at least a portion of the applicator assembly in an interface between the opposed tissue, advancing the trigger assembly from the relaxed position through the first position along the third direction wherein the tissue manipulation assembly moves in the second direction to gather a portion of the tissue, and moving the trigger assembly from the first position to the second position along the third direction wherein the applicator assembly deploys the fastener into opposed tissue along the first direction.  
         [0013]     In yet another embodiment, the invention includes a device for gathering and securing opposed tissue with a fastener. The device includes an applicator means operably configured to deploy a fastener in a first direction, a tissue manipulation means operably configured to move from a relaxed position to a grasping position in a second direction generally transverse to the first direction, and a translating trigger means operably coupled to the applicator means and the tissue manipulation means. The trigger means is operably configured to move from a relaxed position, through a first position, to a second position along a third direction that is generally transverse to both the first direction and the second direction such that manual operation of the translating trigger means from the relaxed position through the first position along the third direction causes the tissue manipulation means to move in the second direction to gather at least a portion of the opposed tissue, and such that continued manual operation of the translating trigger means from the first position on to the second position along the third direction causes the applicator means to deploy the fastener into the opposed tissue along the first direction.  
         [0014]     In yet another embodiment, the invention includes a method for forming an interrupted closure of opposed tissue on adjacent sides of a wound. The method includes the steps of providing an apparatus having a plurality of fasteners, wherein the length of each of the plurality of fasteners is shorter than the longitudinal length of the wound, positioning at least a portion of the fastener apparatus in an interface between the opposed tissue, deploying a first fastener into subcutaneous tissue in a first direction without penetrating the epidermis of the tissue wherein, a single barb of the first fastener is located on each of the opposite sides of the wound, and inserting a second fastener into subcutaneous tissue in a first direction without penetrating the epidermis of the tissue wherein, a single barb of the second fastener is located on each of the opposite sides of the wound. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]      FIG. 1  shows a perspective view of a wound closure instrument incorporating the present invention.  
         [0016]      FIG. 2  is a perspective view of a wound closure instrument showing the trigger in a first position.  
         [0017]      FIG. 3  is a perspective view of a wound closure instrument showing the trigger in a second position.  
         [0018]      FIG. 4  shows a front view of a wound closure instrument incorporating the present invention.  
         [0019]      FIG. 5  shows an enlarged perspective view of a wound closure instrument incorporating the present invention.  
         [0020]      FIG. 6  shows a top view of the cartridge of the present invention.  
         [0021]      FIG. 7  shows a partial cross-sectional view of the cartridge of the present invention.  
         [0022]      FIG. 8  shows a perspective view of the cartridge of the present invention.  
         [0023]      FIG. 9  shows a rear perspective view of the cartridge of the present invention.  
         [0024]      FIG. 10  shown an enlarged perspective view of a wound closure instrument incorporating the present invention.  
         [0025]      FIG. 11  is a side view of an instrument incorporating the present invention.  
         [0026]      FIG. 12  is a partial front perspective view of an instrument incorporating the present invention.  
         [0027]      FIG. 13  is a side partial view of an instrument incorporating the present invention.  
         [0028]      FIG. 14  is an enlarged cross-sectional perspective view of an instrument incorporating the present invention.  
         [0029]      FIG. 15  is a partial perspective view of a wound closure instrument incorporating the present invention.  
         [0030]      FIG. 16  is an exploded view of a wound closure instrument incorporating the present invention.  
         [0031]      FIG. 17  is a perspective view of the applicator assembly in accordance with the present invention.  
         [0032]      FIG. 18  is a partial cross-sectional view of an alternative embodiment of the cartridge of the present invention.  
         [0033]      FIG. 19  is a top view of an absorbable subcuticular skin staple of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0034]      FIGS. 1-4  show wound closure instrument  100 . Instrument  100  can take the form of the Insorb® Subcuticular Stapler as supplied by Incisive Surgical, Inc. of Plymouth, Minn., and as further described in U.S. Pat. No. 6,726,705 and pending U.S. patent applications Ser. Nos. 10/448,838, 10/607,497 and 29/202,831, all of which are incorporated by reference in their entirety.  
         [0035]     Wound closure instrument  100  is comprised of body assembly  102 , a trigger assembly  104 , a tissue manipulation assembly  106 , an applicator assembly  108 , and a fastener assembly  110 . Trigger assembly  104  is capable of moving from a relaxed position as shown in  FIG. 1 , to a first position as shown in  FIG. 2 , to a second position as shown in  FIG. 3 . Trigger assembly  104  incorporates a two-stage mechanism sequentially operating both the tissue manipulation assembly  106  and applicator assembly  108  as shown in  FIGS. 1-3  and  FIG. 16 .  
         [0036]     To grasp tissue with tissue manipulation assembly  106 , an operator grasps instrument  100  so that the operator&#39;s fingers are disposed around trigger  104  and palm is against body assembly  102 . Next, the operator positions tissue manipulation assembly so that skin tissue is vertically aligned between tissue gatherers  246 ( a ) and  246 ( b ). The operator then squeezes trigger assembly  104  toward body assembly  102 . This action causes trigger  238  to rotate about ratchet member  240 . As trigger  238  enters body assembly  102 , connecting arms  242   a ,  242   b  rotate to contact the guide ramp  244  on tissue gatherers  246   a  and  246   b  causing tissue gatherers  246   a ,  246   b  to rotate to the position shown in  FIG. 2 . In this position, skin tissue becomes disposed between tissue gatherers  246   a  and  246   b . As tissue gatherers  246 ( a ),  246 ( b ) rotate to a grasping position on either side of cartridge  200  as shown in  FIG. 18 , the skin tissue is held firmly in place.  
         [0037]     The tissue gatherers  246   a  and  246   b  of the preferred embodiment capture the skin tissue and prepare it for staple insertion. When used in connection with thin or moist skin, it is especially important that the tissue gatherers  246   a  and  246   b  perform the dual function of minimizing movement of the skin tissue during staple insertion. Accordingly, it is desirable for the capture surface  282  to be rough so that the movement of skin tissue can be minimized during staple insertion. For example capture surface  282  can include a plurality of small dimples. Alternatively, capture surface  282  can include a plurality of small bumps or protrusions. In another embodiment, capture surface  282  can include a plurality of jagged grooves. In yet another embodiment, an adhesive may be disposed on capture surface  282 . In still another embodiment, capture surface  282  can include a suction device to create a vacuum between skin tissue and capture surface  282  while a staple is inserted.  
         [0038]     Following manipulation of tissue gatherers  246 ( a ),  246 ( b ) to the grasping position shown in  FIG. 3 , further squeezing of body assembly  102  and trigger assembly  104  causes trigger  238  to move further into body assembly  102  such that interface channel  250  slides around distal connector  252 . As trigger  238  inserts further into body assembly  102 , distal connector  252  reaches the end of interface channel  250  causing rotatable member  254  to rotate about fulcrum  256  such that proximal connector  258  moves in a downward direction. Downward movement of proximal connector  258  causes channel  260  to move in a downward direction resulting in rotatable member  254  rotating about fulcrum  256 . As channel  260  moves downward, connecting tip  262  moves in a forward direction causing insertion slide  264  to advance toward insertion head  266 . As insertion head  266  advances, piercing members  268 ( a ),  268 ( b ) and backspan member  270  cooperatively capture a bottom most fastener from the plurality of fasteners  116 . The bottom-most fastener is advanced through the capture zone  272  and into the target tissue zones  274 .  
         [0039]     Once trigger assembly  104  is released, the pressure from spring  276  moves trigger  238  out of body assembly  102 . This enables ratchet member  240  to also release. Next, piercing members  268 ( a ),  268 ( b ) retract past the plurality of fasteners  116  and biasing member  230  and rod  228  advances the bottom most fastener into position for a future capture by piercing members  268 ( a ),  268 ( b ). As ratchet member  240  releases, spring  276  interacts with upper engagement portion  278  allowing trigger  238  to return to its original position which in turn causes tissue gatherers  246 ( a ),  246 ( b ) to release the grasped tissue. Accordingly, trigger assembly  104  and tissue manipulation assembly  106  return to the position shown in  FIG. 1 . Instrument  100  is then ready to repeat the grasping process and insert a subsequent staple.  
         [0040]     With reference to  FIG. 16 , the details of instrument  100  will now be discussed. Body assembly  102  preferably comprises a clam shell design with a first molded portion  112   a  and a second molded portion  112   b  that can be snapped together, thermally bonded, adhesively bonded or connected via a plurality of fastening members  114 . Body assembly  102  is preferably fabricated from plastic, although a variety of materials may be used while remaining within the scope of the invention.  
         [0041]     Fastener assembly  110  comprises a plurality of bioabsorbable fasteners  116 , for example the dynamic bioabsorbable fasteners described in U.S. patent application Ser. No. 10/603,397, which is incorporated by reference in its entirety, and a fastener cartridge  200 . Bioabsorbable fasteners  116  are stored within fastener cartridge  200  in a stacked configuration.  
         [0042]     Examples of bioabsorbable materials from which bioabsorbable fasteners  116  can be formed include poly(dl-lactide), poly(1-lactide), polyglycolide, poly(dioxanone), poly(glycolide-co-trimethylene carbonate), poly(1-lactide-co-glycolide), poly(dl-lactide-co-glycolide), poly(1-lactide-co-dl-lactide), poly(caprolactone) and poly(glycolide-co-trimethylene carbonate-co-dioxanone). Other polymer, synthetic or biological materials which are designed for initial structural integrity and have the capability of breaking down over time in the body could also be utilized.  FIG. 7  shows a top cross-sectional view of the fasteners  116  disposed in the cartridge  200 . Cartridge  200  includes a cavity  202  that is defined by a first surface  204 , a second surface  206 , a rear surface  208 , and a forward surface  210 . Forward surface  210  includes a protrusion  212  located at the midpoint of the forward surface  210 . Protrusion  212  is shown extending into cavity  202 , toward rear surface  208 , between first surface  204  and second surface  206 . In one embodiment, forward surface  210  includes kanted portions  222  and  224  extending toward protrusion  212 .  
         [0043]     The dimensions of a preferred embodiment of cavity  202  will now be discussed. Kanted portions  222  and  224  define an angle of between 30 and 90 degrees with respect to one another, preferably between 45 and 75 degrees, more preferably between 55 and 65 degrees. The width of protrusion  212  along the dimension extending into cavity  202  is between 0.010 and 0.042 inches, preferably between 0.018 and 0.034 inches. The width of cavity  202  from first surface  204  to second surface  206  is between 0.130 and 0.150 inches, preferably between 0.138 and 0.142 inches. The maximum height of cavity  202  from kanted portion  222  and rear surface  208  is between 0.190 and 0.210 inches, preferably between 0.197 and 0.203 inches. The distance between the tip of protrusion  212  and rear surface  208  is between 0.090 and 1.110 inches, preferably between 0.092 and 1.108 inches. The rear surface  208  defines a curve with a radius of between 0.060 and 0.080 inches, preferably between 0.065 and 0.075 inches, more preferably 0.070 inches.  
         [0044]      FIG. 18  shows a top cross-sectional view of an dynamic fasteners  916  disposed in an alternative embodiment of the cartridge  900 . A description of dynamic fasteners is disclosed in U.S. patent application Ser. No. 10/603,397, which is hereby incorporated by reference in its entirety. Cartridge  900  includes a cavity  902  that is defined by a first surface  904 , a second surface  906 , a rear surface  908 , and a forward surface  910 . Forward surface  910  includes a protrusion  912  located at the midpoint of the forward surface  910 . Protrusion  912  is shown extending into cavity  902 , toward rear surface  908 , between first surface  904  and second surface  906 . In one embodiment, forward surface  910  includes kanted portions  922  and  924  extending toward protrusion  912 .  
         [0045]     Fasteners  116  include a first tip  214 , a second tip  216 , and a body  218  that joins first tip  214  and second tip  216 . In one embodiment, first tip  214  and second tip  216  include barbs  218  and  220 , respectively.  
         [0046]     In a preferred embodiment, fasteners  116  are constrained within cavity  202  by first surface  204  and second surface  206 . This aspect of the invention is desirable for maintaining a constant distance between the first tip  214  and second tip  216 . Fasteners  116  may also be constrained by any or all of the rear surface  208 , forward surface  210 , kanted portions  222 ,  224  and protrusion  212 .  
         [0047]     During operation and use, downward pressure is preferably applied to the plurality of fasteners  116  by rod  228  and biasing member  230 . Rod  228  includes plug  232  configured to apply pressure to the plurality of fasteners  116  in cavity  202 . Biasing member  230  couples with rod  228  at knob  234 . The pressure generated by biasing member  230  against the interior of body assembly  102  and rod  228  generates a downward force by plug  232  against the plurality of fasteners  116 . It will be recognized that other arrangements for application of a biasing force to the plurality of fasteners  116  could also be utilized whereby the function of the biasing member  230  and rod  228  are combined, such as a spring or a flexible metal member. Alternatively, other structures for applying a biasing force could be used in place of rod  228 , such as a piston or a crossbar could be utilized.  
         [0048]     Rod  228  includes a catch  236  that is configured to rest against a corresponding area of molded portion  112  or a removable lock  300 . This enables instrument  100  to be shipped fully assembled to facilitate ease of use by a physician. Preferably, catch  236  and the removable lock  300  prevents biasing member  230  from applying force directly to fasteners  116  during shipment or storage so that the fasteners  116  do not deform after prolonged exposure to the spring force. Preferably, instrument  100  is a multi-shot design in which the plurality of fasteners  116  come preloaded in the cartridge  200  with the cartridge  200  assembled as part of the fastener assembly  110 , thus eliminating any hand loading of individual fasteners. Alternatively, cartridge  200  may be preloaded or hand loaded and designed for insertion into fastener assembly  110  prior to use.  
         [0049]     A preferred embodiment of lock  300  will be described in more detail with respect to  FIGS. 9-15 . Lock  300  includes stopper arms  302 ( a ),  302 ( b ) that extend at approximately a 90 degree angle from lock  300 , through an aperture in instrument  100 . As shown in  FIG. 9 , rod  228  is disposed between stopper  302 ( a ) and  302 ( b ). Rod  228  is positioned at an angle approximately perpendicular to stopper  302 ( a ) and  302 ( b ). Rod  228  includes a wide section  304  near the end of the rod  228  adjacent to the biasing member  230 . Rod  228  also includes a narrow section  306  between the wide section  304  and the plug  232 . As shown in  FIG. 9 , the stopper  302  of lock  300  prevents the wide section  304  of rod  228  from passing through stopper  302 ( a ) and  302 ( b ). In a preferred embodiment, plug  232  is disposed at least partially in the cavity of cartridge  200  when the movement of rod  228  is secured by lock  300 . This mechanism, by its nature, prevents the plurality of fasteners from escaping from the top entrance of the cavity.  
         [0050]     As shown in  FIG. 11 , lock  300  includes lower section  308  that extends into and through insertion head  266  and below cartridge  200 . This feature of the invention holds the plurality of fasteners within the cartridge  200 .  
         [0051]     When instrument  100  is ready to be used, lock  300  is pulled away from instrument  100  such that lower section  308  slides out of insertion head  266 . Stopper  302 ( a ),  302 ( b ) move away from rod  228  and enable rod  228  to slide downward due to the pressure of biasing member  230 . The pressure of biasing member  230  enables plug  232  to apply pressure to the plurality of staples  116  so that the lowest staple is positioned against the applicator assembly  108 . In this configuration, instrument  100  is ready for operation. Preferably, the biasing member  230  is a spring member. Alternatively, arrangements of elastic bands or belts, metal flat springs, or even a gas or liquid pressure activated mechanism could be used to provide the desired biasing force.  
         [0052]     The advantages of the present invention are accomplished by an apparatus and method that engages skin tissue on each side of a skin opening with a fastener that is preferably made of a bioresorbable material. The fastener used may have a variety of configurations and be oriented in a variety of ways as will be further described herein. The location, geometry and orientation of the fastener and the dermal layers in relation to the mechanical apparatus of the present invention are all important considerations to obtaining the most optimal contact and compression of the dermal layer for efficacious closing of the opening. While the skin tissue has been described in connection with an opening in a single piece of tissue, it will be understood that the opening in the skin tissue could also be located between two separate and otherwise unconnected pieces of tissue, or even between a piece of tissue and a piece of biocompatible material to be secured to that piece of tissue.  
         [0053]     Conventional sutures can act like a wick along which infection spreads throughout a wound. The present invention discloses a wound closure instrument  100  having a plurality of fasteners  116 . The wound closure instrument  100  is particularly suitable when the length of the wound is substantially longer than the longitudinal length of a single fastener. This configuration allows for an interrupted closure having a single barb on each side of the wound. It also minimizes the chance of infection spreading from closure to closure. Moreover, the present invention allows for tissue closure without penetrating the epidermis. As a result, infection potential throughout the closure is both decreased and localized.  
       RESEARCH FINDINGS FOR A PREFERRED EMBODIMENT  
       [0054]     A study was conducted to evaluate the clinical performance of absorbable subcuticular staples compared to metal skin staples in terms of safety, efficacy and cosmesis. The trial involved  15  gynecologic surgical patients. Observations of the incisions and patient impressions were documented at specified intervals for up to six weeks post-operatively. The absorbable staples demonstrated equivalent efficacy compared to metal skin staples with significantly improved cosmesis and patient satisfaction. A remarkable decrease in tissue irritation was found over the incisional areas closed with the absorbable staples compared to the regions closed with metal staples. Use of the subcuticular skin stapler was determined to be time effective. In addition, the absorbable staples eliminated the cost and patient discomfort associated with post-operative removal of metal staples.  
         [0055]     The objectives of surgical wound closure are safe, effective wound healing with good cosmetic results. Effective time utilization of health care professionals in the surgical suite and post-operatively can be a determining factor in treatment. A number of incisional closure techniques are available, including a variety of suture materials, metal skin staplers, tissue glues and adhesive dressings. This study was conducted to compare this new modality to metal skin staplers which are routinely utilized in surgical practice.  
         [0000]     Material and Methods  
         [0056]     A single-fire metal applicator was trial to place Applicant&#39;s subcuticular absorbable staples (INSORB™ Subcuticular Skin Staple, Incisive Surgical, Inc., Plymouth, Minn.) in fifteen consecutive patients undergoing routine gynecologic surgeries with lower midline and Pfannenstiel incisions at Fairview Health System Hospitals (Minneapolis, Minn.).  
         [0057]     The procedures included cesarean sections, abdominal hysterectomies, myomectomies and an ovarian cystectomy. Eight of the incisions were closed with a combination of metal skin staples and absorbable staples; seven of the incisions were closed entirely with the absorbable staples.  
         [0058]     The absorbable staples are made of a polylactidepolyglycolide co-polymer with an established history in wound closure. The staple design features a U-shaped curvature with cleats at the two distal ends as shown in  FIG. 19 .  
         [0059]     In this study, Adson forceps in the form of a conventional single tweezer arrangement were used to sequentially grasp each side of the tissue wound and bring the tissue to the head of the fastening apparatus, thereby approximating the sides in a sequential manner, one side at a time. The tissue is held in place by tissue gatherers  246 ( a ),  246 ( b ), when the trigger assembly  104  of the stapler  100  is actuated. Placement of the staple is accomplished by advancing a staple carrier insertion slide  264  with sharp bilateral tips which deploys the staple forward, horizontally into the subcuticular tissue allowing the staple to capture a precise bite of dermis on each side of the incision with even approximation. The cleats of the staple hold the tissue in place after the staple carrier  264  is retracted. The absorbable staples were placed at approximately 8-10 mm intervals. Standard adhesive strips were used on the INSORB closure.  
         [0000]     Results  
         [0060]     The technique was found to successfully place absorbable subcuticular staples. It was also found to be intuitive and represent a relatively flat learning curve for the surgeon and surgical assistant. The device was determined to be time effective. The use of the absorbable subcuticular skin staples resulted in a very uniform, interrupted, everted skin closure without percutaneous tissue insult.  
         [0061]     Incisional closures were observed and patient impressions documented at one, three and six weeks post-operatively.  
         [0062]     The absorbable staples demonstrated equivalent efficacy compared to metal skin staples with significantly improved cosmesis and patient satisfaction. A remarkable decrease in tissue irritation over the incisional areas closed with absorbable staples was found compared to the regions closed with metal staples. The absorbable staples eliminated the cost and patient discomfort associated with post-operative removal of metal staples.  
         [0063]     Documented patient impressions showed a significant increase in patient satisfaction with regards to comfort level and wound appearance. Patients overwhelmingly preferred the absorbable staple closure to the metal skin staple closure.  
       Conclusions  
       [0064]     It has long been understood in the medical community that the optimal incisional closure technique results in minimal tension on the wound edges with good eversion and approximation. Use of the absorbable subcuticular skin staples results in a uniform, interrupted, everted skin closure without the percutaneous tissue insult associated with metal skin staples. The clinical results indicate that the incisional closure is equivalent to metal skin staples with respect to efficacy while additionally eliminating the cost and patient discomfort associated with removal of metal skin staples.  
         [0065]     Applicant&#39;s early experience suggests that the use of absorbable subcuticular skin staples is significantly preferred by patients and is a reasonable alternative to metal skin staples.  
         [0066]     Although the present invention has been described with respect to the various embodiments, it will be understood that numerous insubstantial changes in configuration, arrangement or appearance of the elements of the present invention can be made without departing from the intended scope of the present invention. Accordingly, it is intended that the scope of the present invention be determined by the claims as set forth.