Abstract:
An applicator for deploying a fastener having two legs into tissue. The applicator has two elongated hollow needle members, slotted portions at the distal ends of the hollow needle members for releasably retaining the legs of the fastener, two push rods adapted to move lengthwise in the two needle members, and an actuator for moving the two push rods in the needle members so as to eject the leg portions of the fastener from the slotted portion of the two needle members. A method for deploying the fastener in tissue is also disclosed.

Description:
FIELD OF THE INVENTION  
       [0001]     This invention relates to applicators and methods for deploying surgical fasteners in tissue. More particularly, it relates to certain applicators especially adapted for deploying surgical fasteners to attach tissues to each other, and to attach a mesh to tissue within a deep cavity of the body, such as the pelvic cavity.  
       BACKGROUND OF THE INVENTION  
       [0002]     In many situations, one piece of tissue must be attached to another piece of tissue for wound closure or the surgical repair of tissue defects. For example, an open wound or surgical incision may need to be closed following a surgical procedure. An injury may cause one piece of tissue (e.g., a tendon or pelvic floor tissue after childbirth) to become detached from another piece of tissue (e.g., a bone or pelvic muscle), or a piece of tissue may simply tear (e.g., a piece of meniscal cartilage or pelvic floor tissue).  
         [0003]     The traditional technique for attaching one piece of soft tissue to another piece of soft tissue has involved stitching the two pieces of tissue together using suture. However, in many circumstances such stitching can be challenging either because of the time required to do the stitching or the difficulty of stitching in a particular area of the body. Other techniques have involved using both suture and mesh to support the tissue that has been torn or become degenerated.  
         [0004]     More recently, different types of surgical fasteners have been developed for holding together two pieces of tissue. Among the fasteners which have been developed to date are the so-called T-type fasteners, in which a rod-like head is perpendicularly mounted to the end of a length of flexible filament. Another of these fasteners is the so-called H-type fastener, in which a rod-like head is perpendicularly mounted to the two opposite ends of an intermediate, bridging flexible filament. Appropriate applicator tools have also been developed for deploying such fasteners in tissue.  
         [0005]     Examples of T-type and H-type fasteners, and their associated applicators, are disclosed in U.S. Pat. No. 4,006,747 (Kronenthal et al.); U.S. Pat. No. 4,235,238 (Ogiu et al.); U.S. Pat. No. 4,669,474 (Richards et al.); U.S. Pat. No. 4,705,040 (Mueller et al.); and U.S. Pat. No. 5,941,439 (Kammerer et al.).  
         [0006]     In the case of pelvic floor repair, for example where a pelvic organ prolapses into the vagina, a prominent method of repairing these defect conditions is by a reduction of the prolapse sack through surgery. In certain cases the sack is cut down and the repair is made through suture closures. In other cases a supporting material is placed between the organ which is prolapsing into the vagina. These materials can be cadaver fascia, autologus fascia, animal derived grafts, or synthetic materials such as PROLENE® meshes or other polymeric fabrics or meshes. In the attachment method of these materials within the pelvic cavity, sutures and hand held needles are generally used. The needle is passed, one step at a time through the tissue, then through the material, and then through the tissue again. A deep cavity knot is then tied with multiple throws.  
         [0007]     Another method which has been disclosed for supporting and repairing pelvic structures involves the insertion of trocars through the pelvic muscles to provide a passageway to the repair site. Suture or mesh can be attached to the trocars and consequently passed into the muscle structure. With respect to the mesh, friction between the mesh and surrounding tissue hold the mesh in place to support and repair the pelvic tissue. With respect to suture, the suture is usually required to be tied subcuticularlly. In either case, the insertion of trocars through the pelvic muscles is still very skill dependent.  
         [0008]     Still another method to attach meshes or fabrics to the inside of the pelvic cavity is by placing bone anchors. In this case the anchors are set into the sacrum or pubic bone or ischial spine. A suture is passed through the anchor and the fabric is attached to the suture via knotting. Bone anchors can be painful to the patient as they are inserted through the periostium. Also, if they are metal, and if dislodged, they can migrate within the pelvic cavity. They are sometimes associated with infections of the bone if careful aseptic techniques are not followed since they do break the sealing tissue around the bone and penetrate into the bone.  
         [0009]     In addition to these surgical interventions, there are some pelvic floor repair cases where a tissue shrinkage technique can help. In tissues that have a high content of collagen such as fascia, using an energy source to heat and hence shrink the collagen can effectively tighten the pelvic floor. However, this is a limited application and is generally reserved for procedures, which do not involve significant stretching of the vaginal tissue or breakage of the endopelvic fascia.  
         [0010]     Unfortunately, none of these procedures to repair the pelvic floor by direct suturing or placement of a supportive mesh or bone anchor is optimal. Suturing by itself is time-consuming and skill dependent. The surgical procedures in which mesh is attached to the tissue or a bone anchor is used for attachment are also very skill dependent. This can lead to long operations in a surgical suite with general anesthesia followed by two to three day hospital stays and weeks of recovery. It can also lead to unpredictable outcomes. The energy based tissue shrinkage approach is typically limited to tissue close to or surrounding the urethra, and therefore has limited application. Accordingly, what is needed within the surgical community is an applicator especially adapted for deploying a surgical fastener to attach tissues to each other, and to attach a mesh to tissue within a deep cavity of the body, such as the pelvic cavity.  
       SUMMARY OF THE INVENTION  
       [0011]     In one aspect of the invention, the invention is an applicator for deploying a fastener in tissue where the fastener includes first and second legs generally parallel to each other. The applicator comprises a) a first elongated hollow needle member having a first distal end for penetrating tissue and a first slotted portion at the first distal end for releasably retaining the first leg of the fastener in the first slotted portion of the first elongated hollow needle member; b) a second elongated hollow needle member generally parallel to the first elongated hollow needle member, the second elongated hollow needle member having a second distal end for penetrating tissue and a second slotted portion at the second distal end for releasably retaining the second leg of the fastener in the second slotted portion of the second elongated hollow needle member; c) first and second push rods adapted to move axially from rearward to forward positions within the first and second elongated hollow needle members, respectively; and d) an actuator engageable with the first and second push rods for moving the first and second push rods in the first and second elongated hollow needle members from the rearward to the forward positions so as to eject the first and second legs of the fastener from the first and second slotted portions of the first and second elongated hollow needle members.  
         [0012]     In another aspect of the invention, the invention is a method for deploying a fastener having first and second legs into mammalian tissue at a targeted surgical site. The method comprises the steps of: a) providing an applicator having an applicator distal end, first and second elongated hollow needle members each having a needle distal end for penetrating tissue, first and second slotted portions at the distal ends of the needle members, and first and second push rods engageable with the first and second legs of the fastener and adapted to move axially from rearward to forward positions within the first and second needle members; b) inserting the first and second legs of the fastener within the first and second slotted portions of the needle members; c) positioning the first and second legs of the fastener into first and second receptacles at the distal end of the applicator so as to releasably fix the legs of the fastener within the slotted portions of the needle members; d) advancing the needle members wherein the first and second slotted portions are adjacent to the surgical site within the tissue; and e) actuating the first and second push rods from the rearward to forward positions so as to engage the first and second legs of the fastener and eject the fastener from the slotted portions of the first and second needle members into the tissue.  
         [0013]     The features of the present invention will be more fully disclosed by the following detailed description of the preferred embodiments of the invention, which is to be considered together with the accompanying drawings wherein like numbers refer to like parts. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]      FIG. 1  is a side view of an applicator formed in accordance with the present invention, with the applicator being shown in a first operating position;  
         [0015]      FIG. 2  is a side view of the applicator of  FIG. 1 , with the applicator being shown in a second operating position;  
         [0016]      FIGS. 3-7  are views showing construction details of selected portions of the applicator&#39;s push rod assembly;  
         [0017]      FIG. 8  is a view showing construction details of selected portions of the applicator&#39;s guide shaft assembly;  
         [0018]      FIGS. 9-11  are views showing construction details of selected portions of the applicator&#39;s needle assembly;  
         [0019]      FIG. 12  is a perspective view showing one type of fastener which can be used in conjunction with the present invention;  
         [0020]      FIG. 13  is a view of the fastener of  FIG. 12  as it is held in the distal end of the applicator;  
         [0021]      FIG. 14  is an assembly view of an alternate embodiment of an applicator formed in accordance with the present invention;  
         [0022]      FIG. 15  is a side view of the applicator of  FIG. 14  in a is first operating position;  
         [0023]      FIG. 15A  is side view of the applicator of  FIG. 14  in a second operating position;  
         [0024]      FIG. 15B  is a view showing construction details of selected portions of the push rod assembly of the applicator of  FIG. 14 ;  
         [0025]      FIGS. 15C, 16  and  16 A are views showing construction details of selected portions of the needle assembly of applicator of  FIG. 14 ;  
         [0026]      FIGS. 16B-16C  are views of a shield assembly of the applicator of  FIG. 14  in deployed and retracted positions respectively;  
         [0027]      FIGS. 16D-16E  are views of an alternate embodiment of a shield assembly of the applicator of  FIG. 14  in deployed and retracted positions respectively;  
         [0028]      FIG. 17  is yet another alternate embodiment of an applicator formed in accordance with the present invention,  
         [0029]      FIG. 18  is a view of the applicator of  FIG. 17  with the applicator being shown in a first operating position;  
         [0030]      FIG. 19  is a view of the connection of the guide shaft section to the housing of the applicator of  FIG. 17 ;  
         [0031]      FIG. 20  is a view of the applicator of  FIG. 17  with the applicator being shown in a second operating position;  
         [0032]      FIG. 21  is a view of the inside diameter of the trigger of the applicator of  FIG. 17 ;  
         [0033]      FIG. 22  is a view of the push rod assembly of  FIG. 17 ;  
         [0034]      FIG. 23  is a view of the push rod assembly as it is attached to trigger of the applicator of  FIG. 17 ;  
         [0035]      FIG. 24  is a view of the guide shaft section of the applicator of  FIG. 17 ;  
         [0036]      FIGS. 25-27  are views showing construction details of selected portions of the applicator&#39;s needle assembly of  FIG. 17 ;  
         [0037]      FIGS. 28-31  are schematic views showing various steps in the use of the applicator in an exemplary tissue repair application; and  
         [0038]      FIGS. 32-36  are schematic views showing an alternate method in the use of the applicator in an exemplary tissue repair application.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0039]     Referring initially to  FIGS. 1 and 2 , there is shown an applicator  5  formed in accordance with the present invention. Applicator  5  has a housing  100 , a push rod assembly  200 , a guide shaft assembly  400 , and a needle assembly  500 .  
         [0040]     Housing  100  is preferably configured as a pistol grip so as to easily conform to the hand of a user. Housing  100  serves to provide a support structure for the remainder of the elements of the applicator, as will hereinafter be described in further detail. Housing  100  is preferably formed as two mirror halves (only one of which is shown in  FIG. 1 ) so as to simplify manufacture of the applicator, with the two halves being joined during assembly so as to form the complete housing structure.  
         [0041]     Referring next to  FIGS. 1, 2  and  3 - 7 , push rod assembly  200  has first and second push rods  205  and  206 , respectively, a slide block  210 , a pivot lever  215 , a trigger or actuator  220 , and a compression spring  225 . The proximal end of push rods  205  and  206  are preferably solid, and they are secured to slide block  210  so that both push rods  205  and  206  will move in unison with slide block  210 . The compression spring  225  is situated around push rods  205  and  206  and connects to slide block  210 . The distal end of push rods  205  and  206  contain two flexible but relatively incompressible springs  205 A and  206 A. The springs facilitate the ability of the push rods  205  and  206  to follow the curvature of needle assembly  500  or the distal end of the guide shaft assembly  400 , as will hereinafter be discussed in further detail. Pivot lever  215  and trigger or actuator  220  are pivotally mounted to housing  100 . When trigger or actuator  220  is in its forward or first operating position ( FIG. 1 ), slide block  210  and push rod  205  will be in their rearward or second operating positions ( FIG. 1 ), and when trigger  220  is in its rearward position ( FIG. 2 ), slide block  210  and push rod  205  will be in their forward positions ( FIG. 2 ). Compression spring  225  biases trigger  220  into its forward position, and hence slide block  210  and push rod  205  into their rearward positions ( FIG. 1 ).  
         [0042]     Looking next at  FIGS. 1-3 ,  8  and  9 , guide shaft section  400 , which extends from the housing  100 , has a body  405 . The proximal end of the body  405  is connected in the handle housing by two sets of tabs located on either side of the shaft. One set is located at the proximal end and is shaped as flat wings  410  and  415 , and one set is located mid shaft and shaped as collars  420  and  425 . Both sets of tabs have formed mating configurations within both housing halves. These tabs and configurations are designed to secure the guide shaft within the handle housing  100 . The inner portion of the guide shaft comprises two channels  430  and  435  that extend the entire length of the guide shaft section  400 . The distal ends of these channels are configured to accept two needles  505  and  506 , which will be described in more detail below.  
         [0043]     Referring now to  FIGS. 9, 10 ,  12  and  13 , on the bottom surface of the distal end of guide shaft  400  are first and second fastener receiving and holding receptacles  1010  and  1020 . Each receptacle is formed within the body of the shaft and has two separate sections, a gate section  1011  and  1021 , and a holding section  1012  and  1022 . The gate section is a section of the receptacle at its distal end, which has a narrowed width and beveled surface. The receptacles  1010  and  1020  are sized so that the transverse leg  560  of fastener  515  can slip past the beveled surfaces of gate section  1011  and  1021  and thereafter be releasably captured in the holding sections  1012  and  1022  of the receptacles. The fastener  515  is consequently held in position on needles  505  and  506  during delivery to the surgical site, yet is allowed to separate from the needles under appropriate urging, as will hereinafter be discussed in further detail.  
         [0044]     Referring now to  FIG. 9 , on the side surfaces of the distal end of the guide shaft are two protrusions,  910  and  920 , which are used to guide the needles and guide shaft into the proper alignment with a fastener cartridge (not shown). The protrusions are generally flat wing like structures. They will mate with corresponding slots in a fastener holding cartridge to ensure proper loading of the fastener into the needles and fastener holding receptacles.  
         [0045]     Looking next at  FIGS. 1, 2  and  10 - 11 , needle assembly  500  has first and second hollow needles  505  and  506  whose proximal ends are attached to the distal end of the shaft assembly by a joint  507 . This attachment can be accomplished by gluing, solvent bonding, ultrasonic welding, or injection molding. Needles  505  and  506  can be generally curved along its length or can be straight. The distal ends of needles  505  and  506  terminate in sharp beveled edges  520  and  521 . The proximal ends of needles  505  and  506  are sized to be received in channels  508  and  509  (not shown) within the guide shaft. First and second slotted portions  530  and  531 , respectively, extend along the length of each needle  505  and  506  and communicate with the interior of each hollow needle. Preferably slotted portions  530  and  531  extend along substantially the entire length of needles  505  and  506 ; however, if desired, slotted portions  530  and  531  could be formed in only the distal portion of needles  505  and  506 , and slotted portions  530  and  531  could be omitted from the proximal portion of the needles.  
         [0046]     Referring now to  FIGS. 12 and 13 , needles  505  and  506  are sized to receive the legs  555  and  556  of fastener  515 . More particularly, fastener  515  is preferably a U-type fastener which has a first leg  555 , a second leg  556  generally parallel to the first leg, and a connecting flexible filament  560  ( FIG. 12 ). The fastener  515  may be composed of a non-absorbable material such as polypropylene. Fastener  515  is sized so that its legs  555  and  556  can fit within slotted portions  530  and  531  of needles  505  and  506 . When the legs of the fastener are fitted within the slotted portions of the needles, flexible filament  560  of the fastener extends generally perpendicularly to the needles.  
         [0047]     Referring to  FIGS. 14-16E , there is shown an alternate embodiment of an applicator in accordance with the present invention. Applicator  6  has a housing  800 , an actuation assembly  600 , and a needle insert  700 . Housing  800  has a handle  801  and a gun shaft portion  850 , which is one piece. Handle  801  is preferably configured as a pistol grip for ease of use. Housing  800  serves to provide a support structure for the remainder of the elements of the applicator, as will hereinafter be described in further detail. Housing  800  is preferably formed as two halves joined during assembly so as to form the complete housing structure.  
         [0048]     Referring to  FIGS. 14, 15 ,  15 A and  15 B, actuation assembly  600  has a push rod  610 , a trigger or actuator  815 , and an extension spring  825 . The push rod  610  fits snugly into a groove  835  situated on the gun shaft portion  850  of the housing  800 , so as to withstand movement forward without buckling. At the proximal end is a square slot  820 . This slot is dimensioned to accept a tab  830  situated on the top of trigger  815 , so that the push rod  610  will move forward when the trigger  815  is pushed. The extension spring  825  is situated on a cross pin  810  inside the top of the trigger  815  and connects the trigger  815  to the outside diameter of a connecting pin  805  located on the side of the housing  800 .  
         [0049]     Referring again to  FIGS. 14, 15 ,  15 A and  15 B, the distal end of the actuation assembly  600  has two cylindrical rods  605  and  606 . These rods are configured to be accepted into the proximal end of the needle insert  700  as will hereinafter be discussed in further detail. Trigger  815  is pivotally mounted to housing  800 . When trigger  815  is in its forward or first operating position ( FIG. 15 ), actuation assembly  600  will be in its rearward or position ( FIG. 15 ), and when trigger  815  is in its rearward second operating position (FIG.  15 A), actuation assembly  600  will be in its forward position ( FIG. 15A ). Extension spring  825  biases trigger  815  into its forward position, and hence actuation assembly  600  into its rearward position ( FIG. 15 ).  
         [0050]     Referring again to  FIGS. 14 and 15 , situated below the actuation assembly  600  on the housing  800  is a reinforcement plate  615 . This plate is designed to support the gun shaft portion  850  when the applicator is used during a surgical procedure. As force is applied to the distal end of the applicator and as the actuation assembly  600  is advanced forward, the reinforcement plate supports the actuation assembly  600  and the gun shaft portion  850  preventing buckling of the applicator.  
         [0051]     Referring now to  FIG. 15C , on the bottom surface of the distal end of gun shaft portion  850  are two fastener receiving and holding receptacles  2801  and  2802 . Each receptacle is formed within the body of the shaft and has two separate sections, a gate section  2821  and  2822 , and a holding section  2811  and  2812 . The gate section is a section of the receptacle at its distal end, which has a narrowed width and beveled surface. The receptacles  2801  and  2802  are sized so that the transverse leg of the fastener can slip past the beveled surfaces of gate sections  2821  and  2822  and thereafter be captured in holding sections  2811  and  2812 .  
         [0052]     On the side surfaces of the distal end of the gun shaft assembly  850  are two protrusions,  2831  and  2831 , which are used to guide the needles and guide shaft into the proper alignment with a fastener cartridge (not shown). The protrusions are generally flat wing like structures. They will mate with corresponding slots in a fastener holding cartridge (not shown) to ensure proper loading of the fastener into the needles and fastener holding receptacles.  
         [0053]     Referring to  FIGS. 16 and 16 A, needle insert  700  is configured as a generally flat rectangular plate. On either side of this rectangular plate are two channels  710  and  711  sized to receive the cylindrical rods  605  and  606  described above. The channel lengths are preferably staggered to facilitate ease of assembly of the cylindrical rods  605  and  606  into the channels  710  and  711 . The channels transition to form two hollow needle tips  705  and  706  on the distal end of the needle insert  700 . Needle tips  705  and  706  can be generally curved along their length or they can be straight. The distal ends of needle tips  705  and  706  terminate in sharp beveled edges  720  and  721 . Two slots  730  and  731  extend along the length of each needle tip  705  and  706  and communicate with the interior of each hollow needle. Preferably slots  730  and  731  extend along substantially the entire length of needle tips  705  and  706 ; however, if desired, slots  730  and  731  could be formed in only the distal portion of needle tips  705  and  706 , and slots  730  and  731  could be omitted from the proximal portion of the needles. Needle tips  705  and  706  are sized so as to releasably capture the legs  555  and  556  of fastener  515  as was described above.  
         [0054]     Referring now to  FIGS. 16B-16C , there is shown an optional shield  1600  for the needles of applicator  6 . This may be necessary as the needles may snag or tear tissue as the applicator is inserted into the body, or the user may catch his or her glove on the needles of the applicator. The shield is a tube with a proximal distal ends. The distal end flares into an oval opening  1610 . The proximal end terminates in a handle  1620 . On the bottom of the proximal end is a curved plate  1630  that can be snapped and locked onto the shaft of the applicator. This can be accomplished by a press fit design or a notch and groove design. The distal end of the applicator is inserted into the proximal end of the shield and the curved plate rides upon and snaps onto the top of the applicator. The shield is sized to receive the applicator and allow the applicator to move axially inside the shield to hide and expose the needle tips. The shield can be fitted to the applicator before the user enters it into the incision, or it can be inserted onto the applicator after the shield has been inserted into the surgical site. Once the assembly is in place at the target site, the shield can be moved rearwardly while pushing the needle tips of the applicator forward to expose the needles. The fastener can then be fired into the target tissue.  
         [0055]     Referring now to  FIGS. 16D and 16E , there is an alternate embodiment to the shield. A second channel  1640  is created in the applicator shaft to hold a drive pin located on the shield, which is located on the distal end of the applicator to cover the needle assembly. This pin connects the shield to a spring and actuator assembly in the handle of the applicator. The user is able to pull the shield back into the applicator shaft by depressing a button, or other type of mechanism on the applicator&#39;s handle. The shield may be biased forward so that it is always covering the needles ( FIG. 16D ). After the applicator is inserted into the incision and placed in the correct area, the user would depress a button that would pull the shield back into the applicator&#39;s shaft exposing the needles ( FIG. 16E ) and allowing the user to press the needles of the applicator into the site. Furthermore, the internal shield could be integrated with a trigger lock in such a way that the trigger can only be fired when the shield is in the retracted position.  
         [0056]     Referring now to  FIGS. 17-22 , there is shown yet another embodiment of an applicator in accordance with the present invention. Applicator  7  has a trigger or actuator  900 , a guide shaft assembly  850 , a push rod assembly  1000 , a housing  1100  and a needle assembly  1200 . The trigger  900  is configured as a hollow tube that is situated over the housing  1100 . It is generally cylindrical in shape, and its function is to advance the push rod assembly  1000  forward or backward, as will be described in more detail below. Trigger  900  is attached to the housing by a key  910  positioned on the inside diameter of the trigger that slides in an elongated slot  1150 , which restricts lateral movement of the trigger.  
         [0057]     Another function of housing  1100  is to provide a support structure for the remainder of the elements of the applicator, as will hereinafter be described in further detail. Housing  1100  is preferably formed as two mirror halves (only one of which is shown in  FIG. 18 ) so as to simplify manufacture of the applicator, with the two halves being joined during assembly so as to form the complete housing structure.  
         [0058]     Referring now to  FIGS. 18-20 ,  22  and  23 , push rod assembly  1000  has two push rods  1205  and  1206 , a slide block  1210 , and a compression spring  1225 . The proximal end of push rods  1205  and  1206  are preferably solid, and they are secured to slide block  1210  so that both push rods  1205  and  1206  will move in unison with slide block  1210  when the trigger is advanced forward. The slide block is secured to the trigger by a screw  1230 . The compression spring  1225  is situated around push rods  1205  and  1206  and connects to slide block  1210 . The distal end of push rods  1205  and  1206  contain two flexible but relatively incompressible springs  1205 A and  1206 A. This enables the push rods  1205  and  1206  to follow the curvature of needle assembly  1200  as will hereinafter be discussed in further detail. Trigger is coaxially mounted to housing  1100 , whereby (i) when trigger  900  is in its resting or first operating position ( FIG. 18 ), slide block  1210  and push rods  1205  and  1206  will be in their rearward positions ( FIG. 18 ), and (ii) when trigger  900  is in its forward or second operating position ( FIG. 20 ), slide block  1210  and push rods  1205  and  1206  will be in their forward positions ( FIG. 20 ). Compression spring  1225  biases trigger  900  into its resting position, and hence slide block  1210  and push rods  1205  and  1206  into their rearward positions ( FIG. 20 ).  
         [0059]     Referring to  FIGS. 19 , and  23 - 25 , guide shaft section  860 , which extends from the housing  1100 , has a body  1405  and proximal and distal ends. The proximal end is connected in the housing by a flange  1410  located on the proximal end of the shaft. This is designed to secure the guide shaft within the housing. The inner portion of the guide shaft comprises two channels  1430  and  1435  that extend the entire length of the guide shaft section  860 . The distal ends of these channels receive two needles  2505  and  2506 , which will be described in more detail below.  
         [0060]     Referring now to  FIGS. 25-27 , needle assembly  1200  has two hollow needles  2505  and  2506  whose proximal ends are attached to the distal end of the shaft assembly by a joint  2507 . This attachment can be accomplished by gluing, solvent bonding, ultrasonic welding, or injection molding. Needles  2505  and  2506  can be generally curved along its length or can be straight. The distal ends of needles  2505  and  2506  terminate in sharp beveled edges  2520  and  2521 . The proximal ends of needles  2505  and  2506  are sized to be received within channels  2508  and  2509 . First and second slotted portions  2530  and  2531 , respectively, extend along the length of each needle  2505  and  2506  and communicate with the interior of each hollow needle. Preferably slotted portions  2530  and  2531  extend along substantially the entire length of needles  2505  and  2506 ; however, if desired, slotted portions  2530  and  2531  could be formed in only the distal portion of needles  2505  and  2506 , and slotted portions  2530  and  2531  could be omitted from the proximal portion of the needles. Needles  2505  and  2506  are sized to capture the legs  555  and  556  of fastener  515  as was described in detail previously.  
         [0061]     By way of example but not limitation, the operation of applicator  5  will be discussed in the context of using fastener  515  to repair a pelvic organ prolapse, specifically a cystocele, although many other applications of the present invention will be readily apparent to those skilled in the art.  
         [0062]     Referring now to  FIGS. 28-31 , the user prepares applicator  5  to pick up fastener  515 . More particularly, the user picks up applicator  5 , which is normally in the configuration shown in  FIG. 1  (i.e., with trigger or actuator  220  out). The user then readies applicator  5  to receive fastener  515 , by passing the wings on the distal end of the applicator into the grooves on a cartridge  5000 , which may hold at least one fastener. The distal end of the applicator is advanced so that the legs of the fastener are slid into the slots of the needle assembly and an audible click is heard. At this point fastener  515  is withdrawn from the cartridge using applicator  5 .  
         [0063]     Once the applicator and fastener are ready for use, the user makes a vaginal incision in the anterior wall of the vagina. This is done to gain access to the muscles, ligaments, and other tissue structures of the pelvic floor. Next, the distal end of the applicator is secured to a mesh implant  2900  by pushing the needle assembly into the weave of the mesh. The distal end of the applicator  5  with mesh attached is advanced through the vaginal incision and aligned with the target attachment site  3000 . The applicator and mesh  2900  are then placed on the target attachment site  3000  and the needles are advanced to penetrate the tissue. Then, while keeping pressure on the handle of applicator  5 , the user depresses trigger  220  ( FIG. 2 ) so as to cause push rods  205  and  206  to advance. The distal ends of push rods  205  and  206  engage legs of fastener  515  and eject it out the distal end of needle assembly. In this respect it is to be appreciated that the flexible construction of the distal ends  205 A and  206 A of push rods  205  and  206  permit the push rods to follow the curvature of needles  505  and  506  as the fastener is ejected from the needles. As the fastener&#39;s legs penetrate the target site it forms a U shape around the mesh and the target site. This procedure is then repeated as many times as needed to secure the mesh to the target tissue.  
         [0064]     An alternate embodiment of performing pelvic organ prolapse repair using the applicator of the present invention will now be described. Referring now to  FIGS. 32-36 , the user prepares applicator  5  to pick up fastener  515  as described above. Once the applicator and fastener are ready for use, the user makes a vaginal incision in the anterior wall of the vagina as described above. Next, a length of suture  3200  is placed between the legs of the fastener and the two needles  505  and  506  of the needle assembly on the applicator. The distal end of the applicator  5  with suture positioned and fastener in place is advanced through the vaginal incision and aligned with the target attachment site. The applicator, fastener and suture are then placed on the target attachment site  3300  with the needles penetrating the target tissue. Then, while keeping pressure on the handle of applicator  5 , the user depresses trigger  220  ( FIG. 2 ) so as to cause push rods  205  and  206  to advance. The distal ends of push rods  205  and  206  engage legs of fastener  515  and eject it out the distal end of needle assembly. In this respect it is to be appreciated that the flexible construction of the distal ends  205 A and  206 A of push rods  205  and  206  permit the push rods to follow the curvature of needles  505  and  506  as the fastener is ejected from the needles. As the legs of the fastener penetrate the target site, it captures both the suture and the target tissue site and forms a U shape around the suture and the target site.  
         [0065]     Next, the loose ends of the suture  3300  are then positioned outside the vagina and the user passes these loose ends through a mesh implant  2900 , and then crosses the ends of the suture one over the other. The suture ends are then cinched down with the mesh to the target tissue site and the fastener. The suture is then tied using conventional suture knot tying techniques. In this way, the suture adds an adjustability feature to the mesh placement, as the mesh can then be tightened or loosened as needed. This procedure is then repeated as many times as needed to secure the mesh to the target tissue.  
         [0066]     It is, of course, possible to modify the preferred embodiments of the applicator and its method of operation and use without departing from the scope of the present invention. For example, it is possible to use the applicator of the present invention in a procedure other than the one described above, e.g., one might use the applicator to attach two pieces of tissue in the chest, abdomen, heart, or pelvic cavity. One might form needle assembly  500  so that it incorporates straight needles  505 A and  506 A rather than the curved needles  505  and  506  discussed above. If the needles were straight, then the distal ends  205 A and  206 A of push rods  205  and  206  could be rigid instead of flexible, since it would not need to traverse a curved arc as in the case where a curved needle is used. Alternatively, the distal ends of the push rods could be composed of a flexible plastic, or compliant metal with superelasticity such as Nitinol shape-memory alloy. In still yet another embodiment, it is possible to use applicator of the present invention with other double-legged fasteners rather than with the U-type fastener  515  described above.  
         [0067]     Still other variations obvious to a person skilled in the art are considered to be within the scope of the present invention as shown by the appended claims.