1. Technical Field
The present disclosure relates to looped sutures and methods of forming the same. More particularly, the present disclosure relates to looped sutures including a reinforced welded joint to improve the strength of the suture and resistance to shear failure.
2. Background of Related Art
Loops may be formed in a suture during, or prior to, a wound closing procedure. A loop may be formed in a suture for a number of reasons. For example, during manufacture a loop may be formed in the suture to assist in further processing of the suture, e.g., for holding the suture as barbs are formed along the length thereof. Alternatively, a loop formed in a suture during manufacture may be used to secure the suture to tissue. In this manner, once the non-looped end of the suture is inserted through tissue, that end may be threaded through the loop to form a slip knot-like configuration that may be tied to secure tissue. In another application, a loop may be formed in a suture in place of a knot. This requires the use of a handheld instrument that may be brought into an operating room for securing the first and second ends of a suture that have been received through opposing sections of tissue.
Regardless of the reason for forming the loop, when a loop is formed in a suture, whether using adhesive, heat, or ultrasonic energy, the diameter of the suture is doubled where the two suture portions overlap. In the event that the suture loop is used to secure tissue, the doubling of the diameter of the suture in order to create the loop increases the amount of force necessary to pull the loop through tissue. Therefore, it would be beneficial to have a system and method of forming a looped suture to reinforce the overlapping portion such that the strength of the suture is increased and the suture is more resistant against shear stress failure.
The present sutures include an elongate body and a filler material. The elongate body includes a distal end having first and second overlapping sections forming a loop. The filler material is disposed within at least a portion of a seam defined between the first and second overlapping sections of the elongate body to reinforce the first and second overlapping sections. The first and second overlapping sections may include a taper in a proximal end thereof. In embodiments, the suture includes a bioactive agent.
The elongate body and the filler material may be fabricated from the same or different polymeric materials. In embodiments, the filler material includes a thermoplastic polymer. In embodiments, the first and second overlapping sections of the elongate body may be substantially parallel to each other. In other embodiments, the first and second overlapping sections may be intertwined.
Methods of forming a reinforced looped suture are also described. In accordance with the present methods, a suture including an elongate body including a distal end having first and second overlapping sections defining a loop is provided, and a filler material is applied to a seam defined between the first and second overlapping sections. In embodiments, the filler material is sprayed towards the seam of the first and second overlapping sections of the elongate body. In other embodiments, a pre-molded filler may be applied to the seam of the first and second overlapping sections of the elongate body.
The filler material may be provided at a temperature that is sufficient to locally melt the first and second overlapping sections of the elongate body to create a reinforced joined segment. In embodiment in which the filler material is the same as the material forming the first and second overlapping portions, a homogeneous joined segment is formed. In embodiments, the filler material may be welded to the first and second overlapping sections to create the reinforced joined segment. Welding may be accomplished by the application of radiofrequency (RF), ultrasonic, laser, electric arc discharge, or thermal energy.
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:
A looped suture and method of forming the same are described herein. Various exemplary embodiments of the present disclosure are discussed hereinbelow in terms of a welded looped suture. A looped suture in accordance with the present disclosure includes a first section of suture which is joined with a second section of suture to form a loop. The adjacent surfaces of the first and second sections are reinforced to increase the strength at the junction of the first and second sections of the suture.
In the following discussion, the term “proximal” should be understood as referring to the portion of a structure that is closer to a clinician during proper use. The term “distal” should be understood as referring to the portion of a structure that is further from the clinician during proper use.
The following discussion includes a description of embodiments of the presently disclosed looped suture, as well as a description of exemplary corresponding methods of forming the looped suture and using the looped suture in accordance with the principles of the present disclosure.
Looped sutures described herein may be formed from any sterilizable biocompatible material that has suitable physical properties for the intended use of the suture. The sutures described herein may be monofilament or multifilament sutures formed from natural, synthetic, degradable, and/or non-degradable materials, as well as combinations thereof. The sutures may be formed from biocompatible polymers, such as homopolymers or copolymers, including random copolymers, block copolymers, or graft copolymers. The biocompatible polymers may be linear polymers, branched polymers, or dendrimers.
Representative degradable polymers which may be utilized to form the suture 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; proteins such as albumin, casein, zein, silk, and soybean protein; 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), and 1, dioxepanones (e.g., 1,4-dioxepan-2-one and 1,5-dioxepan-2-one); poly(hydroxyalkanoate)s such as polyhydroxybutyrate, polyhydroxyvalerate, poly(3-hydroxybutyrate-co-3-hydroxyvalerate), polyhydroxyoctanoate, and polyhydroxyhexanoate; polyalkylene oxalates; polyoxaesters; polyanhydrides; polyester anhydrides; polyortho esters; and copolymers, block copolymers, homopolymers, blends, and combinations thereof.
Suitable non-degradable materials which may be utilized to form the sutures 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; polyether-esters such as 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; ethylene-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; carbon fibers; and copolymers and combinations thereof.
The sutures 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 Looped sutures may also be formed by tying a noose, cinch, or knot in a suture. Looped sutures may also be created through use of laser or ultrasonic welding, or through use of degradable or permanent glues or adhesives. In some embodiments, the sutures may include a yarn made of more than one filament, which may contain multiple filaments of the same or different materials. Where the suture is made of multiple filaments, the suture may be made using any known technique such as, for example, braiding, weaving or knitting. The sutures may also be drawn, oriented, annealed, calendared, crinkled, twisted, commingled, or air entangled to form yarns as part of the suture forming process.
Although shown having a circular cross-sectional geometry, the cross-sectional geometry of the suture may be of any suitable shape such as, round, elliptical, square, flat, octagonal, and rectangular.
Referring now to the drawings,
First and second sections 13, 14 of elongate body 11 of looped suture 10 may be welded together to form joined segment 15. Energy is locally applied to first and second sections 13, 14 of elongate body 11 fusing sections 13, 14 together to form joined segment 15. Various types of energy may be applied to first and second sections 13, 14 to form joined segment 15, including RF, ultrasonic, laser, electrical arc discharge, and thermal. Alternatively, first and second sections 13, 14 of elongate body 11 may be joined using glue, epoxy or other adhesives. In yet other embodiments, first and second sections 13, 14 of elongate body 11 may simply be positioned tangentially to, or touching, one another until the application of the filler material, as described in further detail below.
A proximal end 13a of first section 13 may be angled to form a tapered surface 17. Tapered surface 17 angles downwardly towards proximal end 11a of elongate body 11 of looped suture 10. Tapered surface 17 may form an angle “α” relative to a longitudinal axis “X” of second section 14, between zero degrees (0°) and ninety degrees (90°). Tapered surface 17 facilitates insertion of loop 12 into or through tissue. Tapered surface 17 may be formed prior to, during, or following the joining of first and second sections 13, 14. Tapered surface 17 forms a smooth transition with second section 14 of elongate body 11 for ease of insertion through tissue and to decrease the shear stress applied to the first and second sections 13, 14 as looped suture 10 is pulled through tissue.
Although shown having a substantially planar taper, tapered surface 17 may include any number of configurations. For example, tapered surface 17 may be beveled, may include a laterally and longitudinally concave taper, may include a laterally and longitudinally convex taper, or may include any combination thereof. Tapered surface 17 may be selected depending on the tissue being sutured and/or the depth loop 12 is desired to be received within the tissue.
An example of a process of forming a loop 12 is described by Nicholas Maiorino et al. in U.S. Patent Publication No. 2010/0071833, the entire contents of which is herein incorporated by reference. Briefly, this method involves utilizing a system including a base, a suture retaining member, a suture tensioning member, a welding assembly, and a cutting assembly. In this system, proximal end 11a of elongated body 11 is securely locked in a clamp, second section 14 of elongate body 11 is positioned within a channel in the base, and elongate body 11 is wrapped around a pin before first section 13 is placed on top of, or adjacent, second section 14. A distal end 11b of elongate body 11 is then received in a tension cylinder. Once first and second sections 13, 14 are positioned adjacent one another, a welding assembly is approximated towards the suture retaining member to melt the contacting portions between first and second sections 13, 14 to create joined segment 15. The welding assembly may be an ultrasonic welding assembly as described in detail below with reference to
Other methods of forming a looped suture are within the purview of those skilled in the art, such as processes described by Nicholas Maiorino et al. in U.S. Patent Publication Nos. 2010/0101707 and 2010/0276062, the entire contents of which are herein incorporated by reference.
A reinforcement or filler material 18 is applied to the first and second sections 13, 14 about joined segment 15. Filler material 18 is applied to the seam 19 created between the first and second sections 13, 14 to increase the strength of the joined segment 15. Filler material 18 is a biocompatible polymeric material, or composite thereof, that may be the same or different than the material from which the looped suture 10 is fabricated. The filler material 18 reinforces the joined segment 15 by increasing the strength thereof, which may be related to increasing the thickness of the joined segment 15. In embodiments, the filler material 18 may be a thermoplastic polymer that can be heated to a soft and/or molten state, and subsequently cooled to return the filler material 18 to a solid state.
The filler material 18 may be applied to the joined segment 15 utilizing techniques known to one skilled in the art, e.g., dipping, wiping, spraying, etc. For example, the filler material 18 may be applied by spraying a solution or melt of the filler material 18 from the tip 21 of an applicator 20 towards the joined segment 15 as illustrated in
In embodiments, filler material 18 may be provided at a temperature that is sufficient to locally melt the first and second sections 13, 14 of elongate body 11 and create a solid structure (
With reference to
Referring now to
Filler material 118 may be applied to the twisted joined segment 115 along the curved seams 119 formed between the first and second sections 113, 114 and optionally, be welded thereafter. In embodiments, the first and second sections 113, 114 of the joined segment 115 may be ultrasonically welded without the use of filler material 118. Twisting of the first and second sections 113, 114 changes the direction of force required for the suture to fail in shear from a constant pull along the axis of the suture when the first and second sections 13, 14 are aligned substantially parallel with each other (
In embodiments, at least one bioactive agent may be combined with or applied on at least a portion of suture 10 described herein. For example, a bioactive agent may be combined with the polymer used to form the suture, and/or a bioactive agent may be applied as a continuous or discontinuous coating covering at least a portion of a surface thereof. Bioactive agents may be applied onto the suture utilizing any method within the purview of one skilled in the art including, for example, spraying, dipping, brushing, rolling, wiping, painting, extruding, and the like. The at least one agent may be freely released by the suture or may be chemically bound to the surface of the suture.
Bioactive agents include substances which are beneficial and tend to promote the healing process. For example, the looped sutures can be provided with a bioactive agent that will be deposited at the sutured site. The bioactive agent can be chosen for its antimicrobial properties, capability for promoting wound repair and/or tissue growth, or for specific indications such as thrombosis. In embodiments, combinations of such agents may be applied to the medical device of the present disclosure before, during, or after suture formation.
Suitable bioactive agents include, for example, biocidal agents, antimicrobial agents, antibiotics, anti-proliferatives, medicants, growth factors, anti-clotting agents, clotting agents, analgesics, anesthetics, anti-inflammatory agents, wound repair agents and the like, chemotherapeutics, biologics, protein therapeutics, monoclonal or polyclonal antibodies, DNA, RNA, peptides, polysaccharides, lectins, lipids, probiotics, diagnostic agents, angiogenics, anti-angiogenic drugs, polymeric drugs, and combinations thereof.
Although the above bioactive agents have been provided for the purposes of illustration, it should be understood that the present disclosure is not so limited. In particular, although certain bioactive agents are specifically referred to above, the present disclosure should be understood to include analogues, derivatives, and conjugates of such agents.
The sutures may be dyed in order to increase the visibility of the suture in the surgical field. Any dye suitable for incorporation in medical devices may be used. Such dyes include, but are not limited to, carbon black, bone black, FD&C Blue #1, FD&C Blue #2, FD&C Blue #3, FD&C Blue #6, D&C Green #6, D&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).
In use, the looped sutures described herein may include a needle (not shown) on the proximal end thereof. The needle is inserted into and through a first and second flap of tissue. The looped suture may be pulled through the tissue until the proximal end of the first overlapping section contacts the tissue. Once a portion of the loop of the suture is received within the tissue, the proximal end of the suture may be inserted through the loop. The proximal end of the suture may then be pulled tight, thereby approximating the first and second tissue flaps towards one another. The proximal end of the suture may then be knotted or otherwise secured to the loop. In one embodiment, a knot may be formed in the proximal end to prevent the proximal end from withdrawing from the loop. In another embodiment, the proximal end of the suture may be tied directly to the loop.
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.
This application claims the benefit of, and priority to, U.S. Provisional Application No. 61/466,673, filed on Mar. 23, 2011, the entire disclosure of which is incorporated by reference herein.
Number | Date | Country | |
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61466673 | Mar 2011 | US |