Patent Publication Number: US-9833234-B2

Title: Tissue fixation device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a National Stage Application of PCT/US13/55678 under 35 USC §371 (a), which claims the benefit of and priority to U.S. Provisional Patent Application No. 61/691,915, filed Aug. 22, 2012, the entire disclosure of which is incorporated by reference herein. 
    
    
     BACKGROUND 
     Technical Field 
     The present disclosure relates to medical devices and methods of using the same. More particularly, the present disclosure relates to surgical devices for tissue fixation. 
     Background of Related Art 
     Techniques for repairing damaged or diseased tissue are widespread in medicine. Wound closure devices, such as sutures and staples, as well as other repair devices like mesh or patch reinforcements, are frequently used for repair. For example, in the case of hernias, a surgical mesh or patch is commonly used to reinforce the abdominal wall. Typically, sutures, staples, and/or tacks are utilized to fix the surgical mesh or patch to surrounding tissue. 
     The current standard of care for laparoscopic ventral hernia repair, for example, involves the application of stay sutures that are placed both through a surgical mesh and trans-abdominally, and tied down just underneath the skin. Permanent sutures are typically used for this application. The sutures are placed around the perimeter of the mesh, and sometimes in the center to permanently tie the mesh to the area of herniation and to prevent the mesh from sliding within the peritoneum. For each stay suture, a surgeon will pierce the abdominal wall with a suture passer and grasp one end of a suture that has been pre-placed on the mesh, and pull the end of the suture through the abdominal wall and out past the skin. When the two ends of the suture are outside of the patient, the surgeon will pull up on the mesh and tie down a knot in the suture, compressing the abdominal wall and keeping the mesh tight against the peritoneum. The surgeon will then cut the excess suture and close the skin over the knot. This process may take about a minute or two for each stay suture, and may be associated with acute and/or chronic pain, likely due to compression of the abdominal wall and the nerves within it. 
     It would be advantageous to provide a fixation device that simplifies and shortens the time to secure a mesh, and limits or prevents pain caused by abdominal wall and nerve compression. 
     SUMMARY 
     A tissue fixation device includes an elongated body extending between a distal portion including a barbed loop, and a proximal portion including a blunt tip. The elongated body, proximal portion, and distal portion are provided in a variety of configurations. 
     The elongated body may be formed from a single filament or multiple filaments that may each be barbed or unbarbed, and arranged to intersect or remain separate along a length thereof. The filament(s) may be formed from biodegradable and/or non-biodegradable polymeric and/or metallic materials. 
     The proximal portion may be an extension of the elongated body, or may be provided in other configurations, such as a loop. The proximal portion is free of barbs and a needle. In embodiments, the proximal portion may include a cap. The cap may be magnetic or include a ring extending from a proximal end thereof to aid a clinician in placing the tissue fixation device within tissue. The proximal portion may also include indicia. 
     The distal portion may include a pledget. The pledget may be disposed at a distal-most end of the distal portion, or may include spaced openings through which the loop of the distal portion may be laced through. The pledget may include a biocompatible coating. In embodiments, the coating is anti-adhesive, and in other embodiments, the coating may include surface reactive functional groups. The pledget may also include barbs and/or darts to mechanically fix the pledget to tissue. 
     The barbed loop may be fixed to the elongated body, or may be slidable relative thereto. In embodiments, the barbed loop includes a distal portion that is fixed to the elongated body and a proximal portion defining an unfixed ring that is translatable along the elongated body. The barbed loop may be configured to move from a first position in which the barbed loop is expanded, and a second position in which the barbed loop is compressed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and, together with a general description of the disclosure given above, and the detailed description of the embodiment(s) given below, serve to explain the principles of the disclosure, wherein: 
         FIG. 1  is a side view of a tissue fixation device in accordance with an embodiment of the present disclosure; 
         FIGS. 2A-2E  are side views of various embodiments of a distal portion of a tissue fixation device of the present disclosure; 
         FIGS. 3A-3C  are schematic illustrations of an exemplary method of using a tissue fixation device of the present disclosure; 
         FIG. 4  is a side view of a tissue fixation device in accordance with another embodiment of the present disclosure; 
         FIGS. 5A and 5B  are side views of a tissue fixation device in accordance with yet another embodiment of the present disclosure; 
         FIGS. 6A-6K  are side views of various embodiments of body sections of a tissue fixation device of the present disclosure; and 
         FIGS. 7A-7E  are side view of various embodiments of a proximal portion of a tissue fixation device of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     A tissue fixation device and method of using the same are described herein. While the present discussion and figures below depict exemplary embodiments of the present disclosure in terms of a tissue fixation device for use in hernia repair, the presently disclosed devices may be utilized in any surgical procedure requiring joining or positioning of tissue, or fastening of surgical implants thereto. 
     A tissue fixation device in accordance with the present disclosure includes an elongated body extending between a distal portion including a barbed loop, and a proximal portion including a blunt tip. The tissue fixation device described herein may be formed from any sterilizable biocompatible material that has suitable physical properties for the intended use of the device. The elongated body, distal portion, and/or proximal portion of the tissue fixation device may be fabricated from any biodegradable and/or non-biodegradable polymeric and/or metallic material that can be used in surgical procedures. 
     The term “biodegradable” as used herein is defined to include both bioabsorbable and bioresorbable materials. By biodegradable, it is meant that the material decomposes, or loses structural integrity under body conditions (e.g., enzymatic degradation or hydrolysis) or is broken down (physically or chemically) under physiologic conditions in the body such that the degradation products are excretable or absorbable by the body. Absorbable materials are absorbed by biological tissues and disappear in vivo at the end of a given period, which can vary, for example, from hours to several months, depending on the chemical nature of the material. It should be understood that such materials include natural, synthetic, bioabsorbable, and/or certain non-absorbable materials, as well as combinations thereof. 
     Representative natural biodegradable polymers include: polysaccharides such as alginate, dextran, chitin, chitosan, hyaluronic acid, cellulose, collagen, gelatin, fucans, glycosaminoglycans, and chemical derivatives thereof (substitutions and/or additions of chemical groups include, for example, alkyl, alkylene, amine, sulfate, hydroxylations, carboxylations, oxidations, and other modifications routinely made by those skilled in the art); catgut; silk; linen; cotton; and proteins such as albumin, casein, zein, silk, soybean protein, and copolymers and blends thereof; alone or in combination with synthetic polymers. 
     Synthetically modified natural polymers include cellulose derivatives such as alkyl celluloses, hydroxyalkyl celluloses, cellulose ethers, cellulose esters, nitrocelluloses, and chitosan. Examples of suitable cellulose derivatives include methyl cellulose, ethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, hydroxybutyl methyl cellulose, cellulose acetate, cellulose propionate, cellulose acetate butyrate, cellulose acetate phthalate, carboxymethyl cellulose, cellulose triacetate, and cellulose sulfate sodium salt. 
     Representative synthetic biodegradable polymers include polyhydroxy acids prepared from lactone monomers such as glycolide, lactide, caprolactone, ε-caprolactone, valerolactone, and δ-valerolactone, carbonates (e.g., trimethylene carbonate, tetramethylene carbonate, and the like), dioxanones (e.g., 1,4-dioxanone and p-dioxanone), 1,dioxepanones (e.g., 1,4-dioxepan-2-one and 1,5-dioxepan-2-one), and combinations thereof. Polymers formed therefrom include: polylactides; poly(lactic acid); polyglycolides; poly(glycolic acid); poly(trimethylene carbonate); poly(dioxanone); poly(hydroxybutyric acid); poly(hydroxyvaleric acid); poly(lactide-co-(ε-caprolactone-)); poly(glycolide-co-(ε-caprolactone)); polycarbonates; poly(pseudo amino acids); poly(amino acids); poly(hydroxyalkanoate)s such as polyhydroxybutyrate, polyhydroxyvalerate, poly(3-hydroxybutyrate-co-3-hydroxyvalerate), polyhydroxyoctanoate, and polyhydroxyhexanoate; polyalkylene oxalates; polyoxaesters; polyanhydrides; polyester anyhydrides; polyortho esters; and copolymers, block copolymers, homopolymers, blends, and combinations thereof. 
     Some non-limiting examples of suitable non-degradable materials include: polyolefins such as polyethylene (including ultra high molecular weight polyethylene) and polypropylene including atactic, isotactic, syndiotactic, and blends thereof polyethylene glycols; polyethylene oxides; polyisobutylene and ethylene-alpha olefin copolymers; fluorinated polyolefins such as fluoroethylenes, fluoropropylenes, fluoroPEGSs, and polytetrafluoroethylene; polyamides such as nylon, Nylon 6, Nylon 6,6, Nylon 6,10, Nylon 11, Nylon 12, and polycaprolactam; polyamines; polyimines; polyesters such as polyethylene terephthalate, polyethylene naphthalate, polytrimethylene terephthalate, and polybutylene terephthalate; polyethers; polybutester; polytetramethylene ether glycol; 1,4-butanediol; polyurethanes; acrylic polymers; methacrylics; vinyl halide polymers such as polyvinyl chloride; polyvinyl alcohols; polyvinyl ethers such as polyvinyl methyl ether; polyvinylidene halides such as polyvinylidene fluoride and polyvinylidene chloride; polychlorofluoroethylene; polyacrylonitrile; polyaryletherketones; polyvinyl ketones; polyvinyl aromatics such as polystyrene; polyvinyl esters such as polyvinyl acetate; etheylene-methyl methacrylate copolymers; acrylonitrile-styrene copolymers; ABS resins; ethylene-vinyl acetate copolymers; alkyd resins; polycarbonates; polyoxymethylenes; polyphosphazine; polyimides; epoxy resins; aramids; rayon; rayon-triacetate; spandex; silicones; and copolymers and combinations thereof. 
     In embodiments, the elongated body, distal portion, proximal portion, or portions thereof may be formed from polybutester, a copolymer of butylenes terephthalate and polytetramethylene ether glycol. For example, the tissue fixation device, or portions thereof, may be formed from the commercially available nonabsorbable polybutester monofilaments, sold under the trade name Novafil™ by Covidien. In some embodiment, the tissue fixation device, or portions thereof, may be formed from a copolymer of glycolic acid and trimethylene carbonate, such as, for example, Maxon™, commercially available from Covidien. In embodiments, the tissue fixation device, or portions thereof, may be formed from a terpolymer of glycolic acid, trimethylene carbonate, and dioxanone, such as, for example, Biosyn™, commercially available from Covidien. 
     In embodiments, the tissue fixation device may include: metals such as steel or titanium; metal alloys including degradable alloys such as iron-based or magnesium-based degradable alloys; and the like. 
     The elongated body of the tissue fixation device described herein may be formed from monofilament or multi-filament structures that are fabricated from natural, synthetic, degradable, and/or non-degradable materials, as well as combinations thereof, as described above. The elongated body may be formed using any technique within the purview of those skilled in the art such as, for example, extrusion, molding, casting, and/or spinning. Where the elongated body is made of multiple filaments, the elongate body may be formed using any known technique such as, for example, braiding, weaving or knitting. The filaments may also be drawn, oriented, annealed, calendared, crinkled, twisted, commingled, or air entangled to form the elongated body. 
     In embodiments, the elongated body, or portions thereof, may be barbed. The barbs may be single or compound barbs formed along a portion or the entire length of the elongated body in specified or random patterns. Barbs may be formed from angled cuts in an outer surface of the elongated body, or barbs may be molded on the outer surface of the elongated body, such that an inner surface of the barb is positioned opposite to an outer surface of the elongated body. The barbs may all be oriented in the same or different directions, and may be cut at the same or different barb angles. Compound barbs include an inner surface including at least two angled cuts disposed at first and second orientations, respectively, relative to a longitudinal axis of the elongated body. Examples of compound barbs which may be utilized include those disclosed in U.S. Patent Application Publication No. 2009/0210006, entitled “Compound Barb Medical Device and Method”, the entire disclosure of which is incorporated by reference herein. 
     The surface area of the barbs may vary. For example, fuller-tipped barbs can be made of varying sizes designed for specific surgical applications. When joining fat and relatively soft tissues, large barbs may be desired, whereas smaller barbs may be more suitable for collagen-dense tissues. In some embodiments, a combination of large and small barbs on the same structure may be beneficial, for example, when used in a tissue repair with differing tissue layer structures. A combination of large and small barbs may be used within the same tissue fixation device such that the barb sizes are customized for each tissue layer to ensure maximum holding properties. 
     The distal portion includes a barbed loop. The barbed loop may be permanently or releasably secured to the elongated body by convention means, such as, for example, ultrasonic welding or with the use of adhesives, or may be integrally formed with the elongated body. Similarly, the proximal portion may be a component separate from, and joined to, the elongated body, or monolithically formed with the elongated body. The proximal-most end of the proximal portion includes a blunted or unsharpened tip for atraumatic insertion into tissue. The distal and/or proximal portions may be formed from the same or different materials than that of the elongated body. 
     Referring now to the drawings,  FIG. 1  illustrates a tissue fixation device  100  of the present disclosure. Tissue fixation device  100  includes an elongated body  110 , a proximal portion  120 , and a distal portion  130 . The elongated body  110  extends between the proximal portion  120  and the distal portion  130 , and is illustrated as a solid structure that is free of barbs. Although shown as having a substantially circular cross-sectional geometry, the elongated body portion may be any suitable shape, such as round, elliptical, square, flat, octagonal, and rectangular, among other geometric and non-geometric shapes. In embodiments, the elongated body  110  may have a varying diameter, e.g., the elongated body may have a smaller diameter at a proximal end that gradually transitions to a larger diameter at a distal end. 
     Proximal portion  120  contiguously extends from the elongated body  110  and terminates in a blunt tip  122 . Distal portion  130  includes a loop  132  having first and second segments  132   a  and  132   b  interconnected by a terminal end portion  132   c . The barbs  134  may be disposed on any portion of the loop  132 , in embodiments, barbs  134  are disposed on at least the portion of the loop  132  closest to the elongated body  110 . As illustrated, barbs  134  are disposed on the first and second segments  132   a  and  132   b  of the loop  132 , and the terminal end portion  132   c  is free of barbs. In otherwords, the distal-most portion of the loop  132   c  is unbarbed. 
     The distal portion of the tissue fixation device may be provided with a pledget, such as those shown in  FIGS. 2A-2E . A pledget may be formed from plastic, polymeric, or other biocompatible materials, including non-degradable and/or degradable materials as described above. For example, in embodiments in which the distal portion of the tissue fixation device is fabricated from a non-degradable material, a non-degradable pledget may be utilized, such as a pledget fabricated from a silicone or fluorocarbon based material, like polytetrafluoroethylene (e.g., TEFLON). Similarly, in some embodiments in which the distal portion of the tissue fixation device is fabricated from a biodegradable material, a biodegradable pledget may be utilized, such as a pledget fabricated from a copolymer of lactide and glycolide. 
     In embodiments, a pledget may include magnetic material to aid a clinician in positioning the pledget against tissue with the use of an external magnet. A pledget may be fabricated from an absorbable and/or non-absorbable magnet material, such as a ferromagnetic metal. Suitable metals include iron ore (magnetite or lodestone), cobalt and nickel, rare earth metals like gadolinium and dysprosium, and alloys thereof. The pledget may also be made from composite materials such as ceramic or ferrite, alnico (a combination of aluminum, nickel and cobalt with iron), or triconal (a combination of titanium, cobalt, nickel and aluminum with iron). In some embodiments, a pledget may be formed from a polymeric material including ferromagnetic metal particles. The polymer may be any biodegradable and/or non-biodegradable polymer as described above. In embodiments, ferromagnetic metal particles may be freely admixed or co-extruded with the polymer forming the pledget, or may be tethered to the polymer through any suitable chemical bond. In some embodiments, the ferromagnetic metal particles may be spray or dip coated on a formed pledget. 
     A pledget  240  may be securely fastened to terminal end portion  232   c  of the loop  232  of a distal portion  230 , as illustrated in  FIG. 2A , or may include openings  342  that are dimensioned to allow passage of the first and second segments  332   a  and  332   b  of loop  332  therethrough so that the pledget  340  may be positioned along any portion within loop  332  of the distal portion  330 , as illustrated in  FIG. 2B . 
     In embodiments, a pledget may include a coating. The coating may be utilized to alter the physical properties on the surface of the pledget (e.g., enhance lubricity), or may provide a therapeutic benefit to tissue. In general, a coating may be applied to a surface of the pledget, or selective regions thereof, by, for example, spraying, dipping, brushing, vapor deposition, co-extrusion, capillary wicking, film casting, molding, etc. 
     Therapeutic agents include any substance or mixture of substances that have clinical use. Alternatively, a therapeutic agent could be any agent which provides a therapeutic or prophylactic effect; a compound that affects or participates in tissue growth, cell growth and/or cell differentiation; a compound that may be able to invoke or prevent a biological action such as an immune response; or a compound that could play any other role in one or more biological processes. A variety of therapeutic agents may be coated on a pledget, or incorporated into the tissue fixation device of the present disclosure. Moreover, any agent which may enhance tissue repair, limit the risk of sepsis, and modulate the mechanical properties of the tissue fixation device (e.g., the swelling rate in water, tensile strength, etc.) may be added to the material forming the tissue fixation device or may be coated thereon. 
     Examples of classes of therapeutic agents which may be utilized in accordance with the present disclosure include antimicrobials, analgesics, antipyretics, anesthetics, antiepileptics, antihistamines, anti-inflammatories, cardiovascular drugs, diagnostic agents, sympathomimetics, cholinomimetics, antimuscarinics, antispasmodics, hormones, growth factors, muscle relaxants, adrenergic neuron blockers, antineoplastics, immunogenic agents, immunosuppressants, gastrointestinal drugs, diuretics, steroids, lipids, lipopolysaccharides, polysaccharides, and enzymes. It is also intended that combinations of therapeutic agents may be used. 
     Other therapeutic agents which may be in the present disclosure include: local anesthetics; non-steroidal antifertility agents; parasympathomimetic agents; psychotherapeutic agents; tranquilizers; decongestants; sedative hypnotics; steroids; sulfonamides; sympathomimetic agents; vaccines; vitamins; antimalarials; anti-migraine agents; anti-parkinson agents such as L-dopa; anti-spasmodics; anticholinergic agents (e.g., oxybutynin); antitussives; bronchodilators; cardiovascular agents such as coronary vasodilators and nitroglycerin; alkaloids; analgesics; narcotics such as codeine, dihydrocodeinone, meperidine, morphine and the like; non-narcotics such as salicylates, aspirin, acetaminophen, d-propoxyphene and the like; opioid receptor antagonists such as naltrexone and naloxone; anti-cancer agents; anticonvulsants; anti-emetics; antihistamines; anti-inflammatory agents such as hormonal agents, hydrocortisone, prednisolone, prednisone, non-hormonal agents, allopurinol, indomethacin, phenylbutazone and the like; prostaglandins and cytotoxic drugs; estrogens; antibacterials; antibiotics; anti-fungals; anti-virals; anticoagulants; anticonvulsants; antidepressants; antihistamines; and immunological agents. 
     Other examples of suitable therapeutic agents which may be included in the present disclosure include: viruses and cells; peptides, polypeptides and proteins, as well as analogs, muteins, and active fragments thereof; immunoglobulins; antibodies; cytokines (e.g., lymphokines, monokines, chemokines); blood clotting factors; hemopoietic factors; interleukins (IL-2, IL-3, IL-4, IL-6); interferons (β-IFN, (α-IFN and γ-IFN)); erythropoietin; nucleases; tumor necrosis factor; colony stimulating factors (e.g., GCSF, GM-CSF, MCSF); insulin; anti-tumor agents and tumor suppressors; blood proteins; gonadotropins (e.g., FSH, LH, CG, etc.); hormones and hormone analogs (e.g., growth hormone); vaccines (e.g., tumoral, bacterial and viral antigens); somatostatin; antigens; blood coagulation factors; growth factors (e.g., nerve growth factor, insulin-like growth factor); protein inhibitors; protein antagonists; protein agonists; nucleic acids such as antisense molecules, DNA, and RNA; oligonucleotides; and ribozymes. 
     As illustrated in  FIG. 2C , a distal portion  430  includes a pledget  440 . A bottom/distal surface  444  of the pledget  440  may include an anti-adhesive coating that acts as a barrier layer between the tissue fixation device and surrounding tissue to prevent the formation of adhesions, and a top surface  446  of the pledget  440  may be surface treated in order to promote adhesion to tissue. In embodiments, the top surface  446  may include a coating containing tissue reactive functional groups for fixation of the pledget  440  to tissue by crosslinking with reactive groups present in tissue such as primary amine groups, secondary amine groups, hydroxyl groups, carboxylic groups, sulfonic groups, combinations thereof, and the like. Such groups include compounds possessing chemistries having some affinity for tissue. 
       FIGS. 2D and 2E  illustrate a distal portion  530 ,  630 , respectively, including a pledget  540 ,  640  having mechanical means of attachment to tissue. The pledget may include mechanical barbs, grips, hooks, or darts to achieve, or enhance, adhesivity to tissue. As illustrated in  FIG. 2D , a pledget  540  may include a mechanical dart  550  including a base portion  552  tapering toward a sharp tip  554 . The base portion  552  includes a larger diameter than the tip  554  for enhanced tissue fixation. As illustrated in  FIG. 2E , pledge  640  may including mechanical darts  650  each of which include an arm  652  having a sharp or pointed tip  654  for piercing and gripping tissue. 
       FIGS. 3A-3C  illustrate an exemplary method for fixing a hernia mesh “M” to tissue with a tissue fixation device of the present disclosure. It should be understood that embodiments described herein may be generally inserted into tissue and positioned in a similar manner. The below described insertion method is applicable to other embodiments described herein. As illustrated in  FIG. 3A , tissue fixation device  100   a  is delivered to a surgical site and positioned with the elongated body  110  and proximal portion  120  extending through the tissue “T”, and the distal portion  330  abutting hernia mesh “M”. The tissue fixation device  100   a  may be delivered to the surgical site using a conventional suturing device, such as an Endo Close™ Single Use Suturing Device, commercially available from Covidien. For example, the tissue fixation device  100   a  may be hooked through a portion of a stylet of the Endo Close™ device and drawn within the cannula of the device. The Endo Close™ device may then be inserted through the tissue and released under the fascia without the need for a sharp piercing tip on the proximal portion of the tissue fixation device. 
     After the tissue fixation device  100   a  is delivered through the tissue “T”, a clinician may pull up on the proximal portion  120  of the tissue fixation device  100   a  such that the distal portion  330  is compressed against the hernia mesh “M” and tissue “T”, as illustrated in  FIG. 3B . The barbs  334  located on the distal portion  330  of the tissue fixation device  300  adhere to the hernia mesh “M” and/or tissue “T”, fixing the distal portion  330  thereagainst. The clinician may then cut the proximal portion  120 , or a portion of the elongated body  110 , for example, along cut line “C”, allowing the tissue fixation device  100   a  to hold the hernia mesh “M” against tissue “T” without compressing the tissue “T” with a suture knot, as required by traditional devices. In embodiments, the proximal portion  120  may be formed from a biodegradable material and the distal portion  330  may be formed from a non-degradable material to aid in patient comfort by limiting the mass of the tissue fixation device within the tissue while retaining fixation integrity of the hernia mesh “M”. 
     The loop of a tissue fixation device may, alternatively or additionally, include sections of reduced diameter to account for bending moments in the distal portion during use. For example, as illustrated in  FIG. 4 , tissue fixation device  100   b  includes a distal portion  130   a  in which the loop  132   a  includes notches  136  in a surface thereof to increase flexibility of the loop and/or to preferentially bend or fold the loop, and barbs  134   a  disposed on the loop  132   a.    
     With reference now to  FIGS. 5A and 5B , the size of the loop of a tissue fixation device in accordance with the present disclosure may be adjustable. Tissue fixation device  700  is substantially similar to tissue fixation device  100  and will therefore only be described as related to differences therebetween. Tissue fixation device  700  includes a proximal portion  720  and a distal portion  730  that is slidably disposed along elongated body  710 . The distal portion  730  is configured as a loop  732 , including barbs  734 , in which terminal distal end  732   c  is contiguous with a terminal end of the elongated body  710 , and the first and second segments  732   a  and  732   b  are joined at a proximal end to form an unattached ring  735  that is translatable along the elongated body  710 . The loop  732  is configured to move from a first position in which the loop is expanded, as shown in  FIG. 5A , and a second position in which the loop is compressed, as illustrated in  FIG. 5B . Accordingly, as a clinician pulls up on the tissue fixation device  700 , once placed in tissue, the ring  735  slides down the elongated body  710  and into the compressed configuration of  FIG. 5B . 
     The elongated body of the tissue fixation device of the present disclosure may be provided in a variety of configurations. The elongated body may include body sections having a structure, such as barbs and/or multi-filaments segments, that is different from that of the monofilament structure of  FIG. 1 . The body sections may extend along the entire length of the elongated body, or along portion(s) thereof. For example, as illustrated in  FIG. 6A , an elongated body  210   a  of a tissue fixation device  200   a  may include a body section  211   a  including barbs  212   a  extending along the entire length thereof to aid in fixing the tissue fixation device within tissue. In some embodiments, as illustrated in  FIG. 6B , a body section  211   b  including barbs  212   b  may be provided on a portion of the elongated body  210   b  of a tissue fixation device  200   b . And in other embodiments, as illustrated in  FIG. 6C , a body section  211   c  including barbs  212   c  may be provided in spaced intervals along the length of the elongated body  210   c  of a tissue fixation device  200   c . As described above with respect to the barbs of the distal portion of the tissue fixation device, the barbs  212  of the elongated body  210  may also be provided with any barb configuration (e.g., single or compound), in any pattern thereon. 
       FIGS. 6D-6K  illustrate exemplary embodiments of other body sections that may be incorporated into an elongated body of the present disclosure. As illustrated in  FIG. 6D , for example, a body section  311   a  may include a combination of barbed and unbarbed filaments  314  that are substantially separate and in spaced relation to each other along a majority of the length thereof, and united only at pre-defined points  316  positioned at opposed terminal ends of the body section  311   a . The filaments  314  may be bonded, welded, fused, knotted, braided, twisted, entangled, or otherwise joined at the pre-defined points  316 .  FIG. 6E  differs from  FIG. 6D  in that all of the filaments  314  of the elongated body  310   b  in  FIG. 6E  include barbs  312 . 
     Alternatively, as illustrated in  FIGS. 6F-6K , filaments may be commingled along the length of a body section.  FIG. 6F  illustrates a body section  411   a  including a plurality of filaments  414  each including barbs  412  in a braided configuration.  FIG. 6G  illustrates a body section  411   b  including a plurality of filaments  414  that intersect at least one other filament at pre-defined points  416  along the length of the body section  411   b . As shown, all filaments  414  intersect at pre-defined points  416  that are substantially evenly spaced along the length of the body section  411   b . In other embodiments, the pre-defined points may be unevenly spaced along the length of the body section. As shown in  FIG. 6H , for example, varying the spacing between pre-defined points  416  may provide the body section  411   c  with a tapered or varied shape along the length thereof. 
       FIG. 6I  illustrates a body section  511   a  including a plurality of filaments  514  including a central filament  514   a  and at least one outer filament  514   b . The outer filament  514   b  is joined to the central filament  514   a  at pre-defined points  516  therealong, such as by fusing the central filament  514   a  and the outer filament  514   b  together. The central filament  514   a  is illustrated as being free of barbs and the outer filaments  514   b  as including barbs  512 . In embodiments, the central filament  514   a  may be formed from a non-absorbable material and the outer filaments  514   b  may be formed from an absorbable material. In some embodiments, the central filament  514   a  may have a larger diameter than the outer filaments  514   b . In other embodiments, as illustrated in  FIG. 6J , the shape of the body section  511   b  may be varied by varying the length of the outer filaments  514   b  provided between the pre-defined points  516 . 
       FIG. 6K  illustrates an elongated body  610  including a central filament  614   a  and an outer filament  614   b  twisted around the central filament  614   a . As illustrated, the central filament  614  is free of barbs and the outer filament  614   b  includes barbs  612 , however, it is envisioned that any barbed/unbarbed configuration of filaments may be utilized. It should be understood that the body section may include any number of barbed and/or unbarbed filaments that are gathered in a variety of configurations. The filaments may all be fabricated from the same or different materials, and be of the same or different cross-sectional diameter or size. 
     Referring again to  FIG. 1 , the proximal portion  120  is illustrated as a longitudinally extending segment terminating in an unsharpened tip  122 . The proximal portion of the tissue fixation device may also be provided in a variety of other configurations having a blunted tip, such as that shown in  FIG. 7A . As illustrated in  FIG. 7A , a proximal portion  220  may be formed into a loop  222 . As illustrated in  FIG. 7B , a proximal portion  320  may terminate in a cap  324 . The cap may be formed from any polymeric and/or metallic material as described above, and in embodiments in which the elongated body is formed from a plurality of filaments, may be utilized to gather and crimp the filament together at a terminal end thereof. 
     In embodiments, as shown, for example, in  FIG. 7C , the cap  424  of a proximal portion  420  may be formed from a magnetic material, such as those described above in reference to the pledget of the distal portion. 
     In embodiments, the cap may include indicia, such as shapes, symbols, numerals, text, among other markings, for identifying the proximal portion of the tissue fixation device.  FIG. 7D  illustrates a proximal portion  520  including a cap  524  including indicia  526 . The indicia may be in any shape and size to provide a visibly distinguishable mark or pattern on the proximal portion of the tissue fixation device. In embodiments, indicia may be applied by utilizing ink that may be visualized under visible, infrared, ultraviolet, and/or by other wavelengths of light. In some embodiments, dyes may be utilized. Dyes include, but are not limited to, carbon black, bone black, FD&amp;C Blue #1, FD&amp;C Blue #2, FD&amp;C Blue #3, FD&amp;C Blue #6, D&amp;C Green #6, D&amp;C Violet #2, methylene blue, indocyanine green, other colored dyes, and combinations thereof. It is envisioned that visualization agents may also be used, such as fluorescent compounds (e.g., fluorescein or eosin), x-ray contrast agents (e.g., iodinated compounds), ultrasonic contrast agents, and MRI contrast agents (e.g., Gadolinium containing compounds). A variety of applicators within the purview of those skilled in the art may be used to apply the indicia, including, for example, syringes, droppers, markers or pen-like applicators, brushes, sponges, patches, combinations thereof, and the like. 
       FIG. 7E  illustrates a proximal portion  620  including a cap  624  having a ring  622  extending proximally therefrom. A ring  622  may be utilized to aid a clinician in pulling a tissue fixation device up through tissue, as described above with respect to the exemplary method of using a tissue fixation device as described above. 
     Persons skilled in the art will understand that the devices and methods specifically described herein, and illustrated in the accompanying drawings, are non-limiting exemplary embodiments. It is envisioned that the elements and features illustrated or described in connection with one exemplary embodiment may be combined with the elements and features of another without departing from the scope of the present disclosure. As well, one skilled in the art will appreciate further features and advantages of the disclosed devices and methods based on the above-described embodiments. As such, further modifications and equivalents of the invention herein disclosed can occur to persons skilled in the art using no more than routine experimentation, and all such modifications and equivalents are believed to be within the spirit and scope of the disclosure as defined by the following claims.