1. Technical Field
The present disclosure relates generally to implantable medical devices having at least one tissue gripping element and to methods for forming such devices.
2. Background of Related Art
Surgical meshes may be used during both laparoscopic and open surgery for repair of many types of defects and injuries. For example, surgical meshes are commonly used in the repair of hernias. The meshes may be used to provide support to surrounding tissue, as well as to supplement standard suturing.
During hernia repair, the mesh may be placed over the entirety of damaged tissue and some of the healthy tissue surrounding the defect. The mesh can be held in place by a fixation device that attaches the mesh to the surrounding tissue. A variety of different fixation devices may be used to anchor the mesh into the tissue. For example, a needled suture may be passed through or around the tissue near the defect to hold the mesh in a position which spans the injured tissue. In other instances, staples, tacks, clips and pins are known to be passed through or around the tissue near the defect to anchor the implant in a position which spans the injured tissue.
Unfortunately, the use of such fixation devices may increase the patient's discomfort and, in certain instances, may weaken the tissue to which the fixation devices are attached. Certain techniques involve placing a mesh against the repair site without the addition of a fixation device. For example, in some instances the mesh may be simply positioned within the abdomen allowing the pressure of the peritoneum to hold the mesh against the posterior side of the abdominal wall. However, fixation of the mesh may be helpful in order to avoid folding, shrinkage, and migration of the mesh.
Although methods that require the use of fixation devices have been proven effective in anchoring an implant such as a mesh into the tissue, penetration of the tissue by such devices inflicts additional trauma to the damaged tissue or the tissue near the defect and requires additional time for healing. Thus, implantable devices which do not require the use of sutures, staples, tacks, pins, and/or clips is desirable in order to further limit the amount of trauma to healthy tissue surrounding the wound and caused by the fixation devices.
Accordingly, the present disclosure describes implantable medical devices which include at least one tissue-gripping element, such as a barbed loop or a barbed and spiked nap.
In certain embodiments, the implantable medical devices include a biocompatible substrate having a surface containing at least one barbed loop. The at least one barbed loop may protrude perpendicularly from the surface of the biocompatible substrate. In embodiments, a plurality of barbed loops may be positioned along any portion of the surface of the biocompatible substrate.
In some embodiments, the implantable medical devices described herein include a biocompatible substrate having a surface containing barbed and spiked naps. The barbed and spiked naps may protrude perpendicularly from the surface of the biocompatible substrate. In embodiments, the barbed and spiked naps may be positioned along any portion of the surface of the biocompatible substrate.
Methods of forming such devices are also disclosed. For instance, in certain embodiments, methods of forming a barbed implantable medical device are described which include: providing at least one barbed, biocompatible filament; and, combining the at least one barbed biocompatible filament with a biocompatible substrate to form barbed loops along a surface of the biocompatible substrate. Such methods produce barbed implantable medical devices which include tissue-gripping elements such as barbed loops.
In other embodiments, methods of forming a barbed implantable medical device are described which include: providing a biocompatible substrate having loops protruding perpendicularly from a surface of the biocompatible substrate; and forming barbs on the loops of the medical device.
In addition, methods of forming an implantable medical device having barbed and spiked naps are also described which include: providing a biocompatible substrate having loops protruding perpendicularly from a surface of the biocompatible substrate; forming barbs on the loops of the medical device; and treating a portion of the loops to melt and separate each loop into two barbed and spiked naps.
In some embodiments, methods of forming an implantable medical device having barbed and spiked naps are also described which include: providing at least one barbed, biocompatible filament; combining the at least one barbed biocompatible filament with a biocompatible substrate to form barbed loops along a surface of the of the biocompatible substrate; and, treating a portion of the barbed loops to melt and separate each barbed loop into two barbed and spiked naps.
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the disclosure and, together with a general description of the disclosure given above, and the detailed description of the embodiments given below, serve to explain the principles of the disclosure.
The present disclosure relates to barbed implantable medical devices which display tissue-gripping capabilities. In certain embodiments, the implantable medical devices include at least one barbed loop to attach to tissue. In other embodiments, the implantable medical devices include at least one barbed and spiked nap to attach to tissue. In still other embodiments, the implantable medical devices include at least one barbed loop and at least one barbed and spiked nap to attach to tissue.
The implantable medical devices include a biocompatible substrate having a surface to which the barbed loops, barbed and spiked naps, or a combination of the two may be positioned. The biocompatible substrates are often planar in configuration, however, any two-dimensional or three dimensional shapes suitable for implantation may be used. Some examples of suitable biocompatible substrates include films, foams, meshes, buttresses, patches, tapes, pledgets, occlusion devices, and the like. In certain embodiments, the biocompatible substrate is a surgical mesh.
Any biocompatible material may be used to form the biocompatible substrates and/or the filaments described herein. For example, the substrate may be made from natural, synthetic, bioabsorbable or non-bioabsorbable materials. It should of course be understood that any combination of natural, synthetic, bioabsorbable and non-bioabsorbable materials may be used to form the substrates or filaments described herein. The term “bioabsorbable” as used herein is defined to include both biodegradable and bioabsorbable materials. By bioabsorbable, it is meant that the materials decompose, or lose structural integrity under body conditions (e.g. enzymatic degradation or hydrolysis) or are broken down (physically or chemically) under physiologic conditions in the body such that the degradation products are excretable or absorbable by the body.
Representative natural bioabsorbable materials include: polysaccharides, such as alginate, dextran, chitin, hyaluronic acid, cellulose, collagen, gelatin, fucans, glycosaminoglycans, and chemical derivatives thereof (substitutions and/or additions of chemical groups, for example, alkyl, alkylene, hydroxylations, oxidations, and other modifications routinely made by those skilled in the art); and proteins, such as albumin, casein, zein, silk, 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. These are collectively referred to herein as “celluloses.”
Representative synthetic bioabsorbable polymers include polyhydroxy acids prepared from lactone monomers, such as glycolide, lactide, caprolactone, ε-caprolactone, valerolactone, and δ-valerolactone, as well as pluronics, 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; polyalkylene oxalates; polyoxaesters; polyanhydrides; polyortho esters; and copolymers, block copolymers, homopolymers, blends, and combinations thereof. In certain embodiments, the biocompatible substrate may be formed using a combination of bioabsorbable and non-bioabsorbable polymers.
Some non-limiting examples of suitable non-bioabsorbable materials include polyolefins, such as polyethylene and polypropylene including atactic, isotactic, syndiotactic, and blends thereof; polyethylene glycols; polyethylene oxides; ultra high molecular weight polyethylene; copolymers of polyethylene and polypropylene; polyisobutylene and ethylene-alpha olefin copolymers; fluorinated polyolefins, such as fluoroethylenes, including expanded polytetrafluoroethylene (ePTFE) and condensed polytetrafluoroethylene c(PTFE), fluoropropylenes, fluoroPEGSs, and polytetrafluoroethylene; polyamides, such as nylon and polycaprolactam; polyamines; polyimines; polyesters, such as polyethylene terephthalate and polybutylene terephthalate; aliphatic polyesters; polyethers; polyether-esters, such as polybutester; polytetramethylene ether glycol; 1,4-butanediol; polyurethanes; acrylic polymers and copolymers; modacrylics; vinyl halide polymers and copolymers, such as polyvinyl chloride; polyvinyl alcohols; polyvinyl ethers, such as polyvinyl methyl ether; polyvinylidene halides, such as polyvinylidene fluoride and polyvinylidene chloride; polyacrylonitrile; polyaryletherketones; polyvinyl ketones; polyvinyl aromatics, such as polystyrene; polyvinyl esters, such as polyvinyl acetate; copolymers of vinyl monomers with each other and olefins, such as etheylene-methyl methacrylate copolymers, acrylonitrile-styrene copolymers, ABS resins, and ethylene-vinyl acetate copolymers; alkyd resins; polycarbonates; polyoxymethylenes; polyphosphazine; polyimides; epoxy resins; aramids, rayon; rayon-triacetate; spandex; silicones; and combinations thereof.
The biocompatible substrates may be formed using any method within the purview of those skilled in the art. Some non-limiting examples include, weaving, knitting, braiding, crocheting, extruding, spraying, casting, molding, and combinations thereof. In some embodiments, the biocompatible substrate may be a two or three dimensional surgical mesh which is woven, knitted, braided, or crocheted from at least one first filament to form the substrate. In certain embodiments, the biocompatible substrate may be a surgical mesh consisting of at least one first filament made of polyethylene terephthalate.
The tissue-gripping elements, i.e., the barbed loops and/or the barbed and spiked naps, which are positioned on at least a portion of the biocompatible substrate, may be formed from at least one second filament. The second filaments may be made from any biocompatible, bioabsorbable, or non-bioabsorbable material, including those described herein. In some embodiments, the first and second filaments may be made from the same materials. In other embodiments, the first and second filaments may be made from different materials. For example, in some embodiments, the biocompatible substrate may be formed from at least one first filament made from a non-bioabsorbable material, i.e., polypropylene, and the tissue-gripping elements may be formed from at least one second filament made from a bioabsorbable material, i.e., polylactic acid.
The tissue-gripping elements, whether loops or spiked naps, include a plurality of barbs positioned along the length of the element. The barbs may be disposed in various arrangements along the length of the filament. The barbs may be formed using any suitable method, including but not limited to, injection molding, stamping, cutting, laser, ultrasonics, and the like. The barbs may be uni-directional, multi-directional, symmetrical, non-symmetrical, and combinations thereof.
The second filaments used to form the tissue-gripping elements may be barbed at any time during the manufacturing of the implants described herein. In some embodiments, the second filaments may be barbed prior to being incorporated into the biocompatible substrate. In some embodiments, the second filaments may be barbed after being incorporated into the biocompatible substrate. In still other embodiments the second filaments may be barbed while being incorporated into the biocompatible substrate.
In certain embodiments, the tissue-gripping elements may be made form second filaments added to the substrate as loops which extend from the surface of a biocompatible surface in a generally perpendicular manner. In other embodiments, the tissue-gripping elements may be made from a plurality of second filaments which individually extend from the surface of a biocompatible surface in a generally perpendicular manner. By generally perpendicular the tissue-gripping elements may protrude from the surface of the implant at about 90 degrees. It is envisioned that the tissue-gripping elements may protrude from the surface of the implant from about 75 to about 105 degrees.
Referring now to
In
In
As depicted in
As shown in
Although the substrate is shown to be generally rectangular, the substrates described herein may be of any shape including elliptical, square, triangular, hexagonal, and circular and the like. In addition, the substrate may include apertures to accommodate the passage of bodily tissue when implanted. The implant can be shaped and sized during manufacturing or can be cut to a particular size and shape immediately before use.
Turning to
In certain embodiments, the implantable medical device may be a surgical mesh which made from a plurality of first and second filaments woven in any suitable manner that allows the filaments to form a substrate and form loops or naps which extend from the surface of said substrate.
The front and intermediate guide-bars may be threaded with a first set of filaments or yarns. The intermediate bars may be threaded, one guide full, three guides empty, with monofilament or multifilament yarn. This yarn may be made from any suitable biocompatible material; and in some embodiments, may be made from polyethylene terephthalate. This filament or yarn is represented by a broken line and by reference number 11 in
The front bar is threaded; one guide full, one guide empty, and works in chain weave with a multifilament or monofilament yarn, represented by number 12 in
The rear bar may be threaded, one guide full and one guide empty, with a second filament, i.e., monofilament or multifilament. This second filament or yarn may be made from any suitable biocompatible material; and in some embodiments, may be made from polylactic acid. The second filament may be woven to form the barbed loops or the barbed and spiked naps of the final product.
The diameter of the second filament is over 0.10 millimeter. In practice, this diameter is between 0.14 and 0.18 millimeter and is of the order of 0.15 millimeter. This yarn or filament is represented by reference number 10 and in a solid line in
The different filaments may be worked according to the following chart:
The rear bar places the yarn in partial well under the chain stitch and “thrown” onto the needle not forming a chain stitch. For this reason, at the next row, the needle not forming a chain stitch not being supplied permits escape of the monofilament mesh which forms a loop (see
The medical device thus obtained may be a knit provided with loops which are generally perpendicular to one of the surfaces of the substrate. The loops also display the rigidity to hold at about a right angle, which is obtained by the rigidity or nerve of the second filament employed. This rigidity or nerve may be necessary for the subsequent formation of the spiked and barbed naps or barbed loops which ensure a tissue-gripping function.
Other patterns by which to obtain a knit with loops that protrude from one face should be apparent to one skilled in the art. In embodiments, the second filament used to form the loops can be cut along its length prior to the knitting of the substrate to form barbs. In other embodiments, the second filaments used to form the loops can first be knitted into the substrate and then may be cut along the length of the loops to form barbs.
Each spiked nap 902 thus has a substantially rectilinear body 904 protruding perpendicularly with respect to the substrate 900. Rectilinear body 904 includes attached end 902a and free end 902b, with free end 902b having spike 903 of greater width than that of the body 904 and barbs 905 positioned between attached end 902a and free end 902b. Spike 903 may have the shape of a sphere or mushroom.
In embodiments, the substrate and/or loops or naps of the medical device can be coated with a bioactive agent. The term “bioactive agent”, as used herein, is used in its broadest sense and includes any substance or mixture of substances that have clinical use. Consequently, bioactive agents may or may not have pharmacological activity per se, e.g., a dye. Alternatively a bioactive agent could be any agent that provides a therapeutic or prophylactic effect, a compound that effects or participates in tissue growth, cell growth, cell differentiation, and an anti-adhesive compound, a compound that may be able to invoke a biological action such as an immune response, or could play any other role in one or more biological processes. It is envisioned that the bioactive agent may be applied to the substrate and/or loops or naps in any suitable form, e.g., films, powders, liquids, gels, and the like.
Examples of classes of bioactive agents, which may be utilized in accordance with the present disclosure include: anti-adhesives; 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; platelet activating drugs; clotting factors; and enzymes. It is also intended that combinations of bioactive agents may be used.
Anti-adhesive agents can be used to prevent adhesions from forming between the mesh and the surrounding tissues opposite the target tissue. In addition, anti-adhesive agents may be used to prevent adhesions from forming between the coated implantable medical device and the packaging material. Some examples of these agents include, but are not limited to hydrophilic polymers such as poly(vinyl pyrrolidone), carboxymethyl cellulose, hyaluronic acid, polyethylene oxide, poly vinyl alcohols, and combinations thereof.
Suitable antimicrobial agents which may be included as a bioactive agent include: triclosan, also known as 2,4,4′-trichloro-2′-hydroxydiphenyl ether, chlorhexidine and its salts, including chlorhexidine acetate, chlorhexidine gluconate, chlorhexidine hydrochloride, and chlorhexidine sulfate, silver and its salts, including silver acetate, silver benzoate, silver carbonate, silver citrate, silver iodate, silver iodide, silver lactate, silver laurate, silver nitrate, silver oxide, silver palmitate, silver protein, and silver sulfadiazine; polymyxin, tetracycline; aminoglycosides, such as tobramycin and gentamicin; rifampicin; bacitracin; neomycin; chloramphenicol; miconazole; quinolones such as oxolinic acid, norfloxacin, nalidixic acid, pefloxacin, enoxacin and ciprofloxacin; penicillins such as oxacillin and pipracil, nonoxynol 9, fusidic acid, cephalosporins; and combinations thereof. In addition, antimicrobial proteins and peptides such as bovine lactoferrin and lactoferricin B may be included as a bioactive agent.
Other bioactive agents, which may be included as a bioactive agent 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, dihydrocodeinonc, 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; anti-convulsants; 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; chemotherapeutics, estrogens; antibacterials; antibiotics; anti-fungals; anti-virals; anticoagulants; anticonvulsants; antidepressants; antihistamines; and immunological agents.
Other examples of suitable bioactive agents, which may be included in the mesh or suture 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 such as fibrin, thrombin, fibrinogen, synthetic thrombin, synthetic fibrin, synthetic fibrinogen; 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); bone morphogenic proteins; TGF-B; protein inhibitors; protein antagonists; protein agonists; nucleic acids, such as antisense molecules, DNA, RNA, RNAi; oligonucleotides; polynucleotides; and ribozymes.
The barbed implantable medical devices described herein may be formed using any suitable method known to those skilled in the art. In certain embodiments, one such method may include: providing at least one barbed, biocompatible filament; and combining the at least one barbed biocompatible filament with a biocompatible substrate to form barbed loops along a surface of the biocompatible substrate. In other embodiments, a method may include: providing a biocompatible substrate having loops protruding perpendicularly from a surface of the biocompatible substrate; and forming barbs on the loops of the medical device.
In addition, the barbed loops may be treated in any manner suitable to separate the barbed loops into two separate barbed and spiked naps. For example, it may be useful to apply a certain amount of heat and/or pressure to melt the barbed loop thereby separating the loop into two separate naps and by melting the material used to form the loop, the ends of each separate nap will include a spike thus creating a spiked and barbed nap. The barbed loops may be treated using any suitable method, including heated rollers or cylinders, lasers, ovens, ultrasonics, and the like.
It will be apparent from the foregoing that, while particular forms of the implantable medical devices have been illustrated and described, various modifications can be made without departing from the spirit and scope of the present disclosure. For example, although particular barb configurations may be illustrated and described herein, any suitable configuration and arrangement may be possible.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US2011/047224 | 8/10/2011 | WO | 00 | 3/8/2013 |
Number | Date | Country | |
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61372329 | Aug 2010 | US |