Unidirectional and Bidirectional Anchor Scaffolds
20230157690 · 2023-05-25
Inventors
Cpc classification
A61B17/0644
HUMAN NECESSITIES
A61F2/0063
HUMAN NECESSITIES
A61B2017/0641
HUMAN NECESSITIES
A61F2220/0016
HUMAN NECESSITIES
A61F2250/0067
HUMAN NECESSITIES
A61F2250/0031
HUMAN NECESSITIES
International classification
Abstract
A wound closure device includes multiple base elements arranged in a repeating pattern and a first anchor extending from a first side of each base element of the multiple base elements in a first direction for securing itself to a first layer of tissue along a wound within a body. The wound closure device further includes a second anchor extending from a second side of each base element of the multiple base elements in a second direction that is opposite to the first direction for securing itself within a second layer of tissue along the wound, such that the wound closure device is configured to hold the first and second layers of tissue against each other to close the wound.
Claims
1-20. (canceled)
21. A wound closure device comprising: a plurality of base elements arranged in a repeating pattern; a first anchor extending from a first side of each base element of the plurality of base elements in a first direction for securing itself to a first layer of tissue along a wound within a body; and a second anchor extending from a second side of each base element of the plurality of base elements in a second direction that is opposite to the first direction for securing itself within a second layer of tissue along the wound, such that the wound closure device is configured to hold the first and second layers of tissue against each other to close the wound.
22. The wound closure device of claim 21, wherein the wound closure device is configured to be disposed internal to the body between the first and second layers of tissue.
23. The wound closure device of claim 22, wherein the wound closure device comprises a bidirectional wound closure device.
24. The wound closure device of claim 21, wherein the wound closure device comprises a plurality of first anchors that extend from the first side of each base element of the plurality of base elements.
25. The wound closure device of claim 24, wherein the wound closure device comprises a plurality of second anchors that extend from the second side of each base element of the plurality of base elements.
26. The wound closure device of claim 21, wherein the repeating pattern comprises a two-dimensional array.
27. The wound closure device of claim 21, wherein each base element of the plurality of base elements has an elongate shape.
28. The wound closure device of claim 27, wherein the elongate shape has an aspect ratio of greater than 1:4.
29. The wound closure device of claim 27, wherein the repeating pattern comprises a one-dimensional array of the plurality of base elements arranged in a row.
30. The wound closure device of claim 21, wherein the first and second anchors extend substantially perpendicularly with respect to the base element.
31. The wound closure device of claim 21, wherein the wound closure device is configured to resist forces exerted on the first and second layers of tissue in directions parallel to a substantially planar arrangement of the plurality of base elements when the first and second anchors are secured to the first and second layers of tissue.
32. The wound closure device of claim 21, wherein each base element of the plurality of base elements includes one or more holes formed therein.
33. The wound closure device of claim 21, further comprising a flexible substrate to which the plurality of base elements are coupled in the repeating pattern.
34. The wound closure device of claim 33, wherein the wound closure device is configured to hold the first and second layers of tissue against each other along the flexible substrate to close the wound.
35. The wound closure device of claim 33, wherein the flexible substrate comprises a plurality of loops of material.
36. The wound closure device of claim 35, wherein each base element of the plurality of base elements includes a hole formed therein, and wherein a segment of the plurality of loops of material passes through the hole of the base element.
37. The wound closure device of claim 36, wherein the hole is located along an edge of the base element.
38. The wound closure device of claim 35, wherein each base element of the plurality of base elements includes at least two holes formed therein, and wherein at least two segments of the plurality of loops of material respectively pass through the at least two holes of the base element such that the base element couples at least two loops of the plurality of loops of material to each other.
39. The wound closure device of claim 35, wherein loops of the plurality of loops of material are interlocked with each other.
40. The wound closure device of claim 21, wherein the first anchor comprises a shaft and a head disposed at an end of the shaft, and wherein the first anchor has: a length in a range of 5 mm to 10 mm and a head width in a range of 0.3 mm to 0.5 mm; or a length in a range of 0.75 mm to 1.25 mm and a head width in a range of 0.1 mm to 0.15 mm; or a length in a range of 0.1 mm to 0.2 mm and a head width in a range of 0.1 mm to 0.15 mm; or a length in a range of 2.75 mm to 3.25 mm and a head width in a range of 0.1 mm to 0.15 mm.
41. The wound closure device of claim 21, wherein the first anchor is made of a single material.
42. The wound closure device of claim 21, wherein the first anchor comprises a central core comprising a first material and an outer shell comprising a second material that differs from the first material.
43. The wound closure device of claim 42, wherein the first material is harder than the second material.
44. The wound closure device of claim 21, wherein the first anchor comprises: a shaft; and a head disposed at an end of the shaft, the head comprising: a sharp tip, a plurality of barbs extending away from the sharp tip and radially outward from the shaft, and a plurality of flexible support members respectively connected to the plurality of barbs and to the shaft to limit an extent to which the plurality of barbs can move radially outward from the shaft.
45. The wound closure device of claim 44, wherein the head is configured such that: during a penetration of the first anchor into the first layer of tissue in the first direction, the plurality of barbs moves radially inward toward the shaft, and after the penetration and during a movement of the first anchor within the first layer of tissue in the second direction, the plurality of barbs is prevented from being directed toward the sharp tip.
46. The wound closure device of claim 45, wherein during the movement of the first anchor within the tissue in the second direction, the plurality of barbs moves radially outward from the shaft to secure the first anchor to the first layer of tissue.
47. The wound closure device of claim 21, wherein each of the plurality of base elements, the first anchor, and the second anchor comprises one or more polymers.
48. The wound closure device of claim 47, wherein the plurality of base elements has a different material formulation than at least one of the first anchor and the second anchor.
49. The wound closure device of claim 47, wherein at least one of the plurality of base elements, the first anchor, and the second anchor comprises one or more of polydioxanone, polyglyconate, or polypropylene.
50. The wound closure device of claim 21, wherein the first and second anchors comprise a resorbable material.
51. The wound closure device of claim 21, wherein at least one of the plurality of base elements, the first anchor, and the second anchor comprises a material that elutes a drug.
52. An anchor of a wound closure device, the anchor comprising: a shaft; and a head disposed at an end of the shaft, the head comprising: a sharp tip, a plurality of barbs extending away from the sharp tip and radially outward from the shaft, and a plurality of flexible support members respectively connected to the plurality of barbs and to the shaft to limit an extent to which the plurality of barbs can move radially outward from the shaft.
53. A method of closing a wound during a surgical procedure, the method comprising: placing a wound closure device between a first layer of tissue along the wound within a body and a second layer of tissue along the wound within the body, the wound closure device comprising: a plurality of first anchors extending in a first direction toward the first layer of tissue, and a plurality of second anchors extending in a second direction that is opposite to the first direction and toward the second layer of tissue; and causing the pluralities of first and second anchors to respectively penetrate the first and second layers of tissue to hold the first and second layers of tissue against each other to close the wound.
Description
BRIEF DESCRIPTION OF THE FIGURES
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[0071] Other embodiments not shown herein are contemplated.
DETAILED DESCRIPTION
[0072] Examples of methods and systems are described herein. It should be understood that the words “exemplary,” “example,” and “illustrative,” are used herein to mean “serving as an example, instance, or illustration.” Any embodiment or feature described herein as “exemplary,” “example,” or “illustrative,” is not necessarily to be construed as preferred or advantageous over other embodiments or features. Further, the exemplary embodiments described herein are not meant to be limiting. It will be readily understood that certain aspects of the disclosed systems and methods can be arranged and combined in a wide variety of different configurations.
[0073] It is desirable as part of a variety of medical procedures to secure two tissues together along a planar interface (e.g., between a skin flap and underlying muscle/fascia) in a manner that avoids seroma formation and infection, prevents dehiscence, provides support to the tissues along and across the planar interface, supplies tension to the tissues to enhance wound healing, decrease tension applied to incisions, and prevent puckering, sagging, or other unwanted tissue migration, and/or that satisfies some other aims of a medical procedure. For example, abdominoplasties, breast reductions or reconstructions, facelifts, mastectomies, hernias, or other procedures include securing neighboring tissues together across a large, planar interface.
[0074] Simply placing the tissues in an opposing manner, with sutures or other securing means emplaced along the edge(s) of the interface between the opposing tissues, often results in seroma, hematomas, or other fluid buildup between the opposing tissues, which can lead to infection. The use of sutures in this manner can also take an extended time to emplace, and can lead to puckering in the skin. Correction of these issues can require additional surgical interventions and/or higher experience on the part of the surgeon. To ameliorate these issues, drains can be emplaced, but drains require additional postoperative care and eventual removal, and do not prevent seroma formation or other fluid buildup in all circumstances. Additionally or alternatively, multiple sutures can be placed between the tissues at a variety of places across the interface between the tissues. However, this requires a great deal of time, effort, and skill on the part of the surgeon and can still lead to puckering, seroma formation, or other unwanted effects (e.g., due to the lack of support in directions parallel to the interface between the tissues, due to imperfections in the placement of the sutures, or other factors). Such procedures can also increase the time a patient is in the operating theater and/or under anesthesia, with concomitant increased risks inter alia of infection or other deleterious sequelae.
[0075] Wound closure devices and systems described herein (which can be referred to as “scaffolds”) provide improved outcomes with regard to healing, cosmesis, post-operative care, and other metrics of interest. These systems include a flexible mesh or other substrate (e.g., a woven material, a set of loops of material interlocking with each other) in which is embedded multiple anchoring elements. Each anchoring element includes a base element, via which the anchoring element is coupled to the flexible substrate, and one or more anchors extending from the base element that can penetrate into tissue and then, using barbs or other means, become fixed in the tissue. Where the anchors extend in both directions from the base elements, they can provide ‘vertical’ support between two neighboring volumes of tissue. The connection, via the base elements, to the flexible substrate also allows the wound closure device to provide support in one or both directions parallel to the plane of the interface between the tissues. Further, where the flexible substrate is porous, composed of multiple loops or open elements, or otherwise configured to permit or enhance ingrowth of tissue, the flexible substrate can provide enhanced support over time as tissue ingrowth proceeds.
[0076] Note that, while reference is made to an interface ‘between’ two volumes of tissue, the wound closure devices described herein can be applied to provide support along the ‘external interface’ between skin or some other exposed tissue and the environment of the body. This can be done, e.g., to provide tension along the surface of the skin or other tissue and to transmit that tension across one or more incisions in the tissue, to transmit that tension across a wider area of the tissue (e.g., to areas of the tissue whose interface with underlying tissues has not been recently surgically interrupted), or to transmit tension in some other manner to facilitate healing, reduce sagging, puckering, or loosening of the tissue, to improve cosmetic outcomes, or to provide some other benefit.
[0077] The clinical benefits of the devices described herein include, but are not limited to: 1) providing tension relief on internal suture-based repairs to allow a longer time for fibrosis and scar healing of the suture tension line. This benefit can be applied to any suture line under tension or that might exhibit poor wound healing due to other conditions, e.g., hernia repairs, muscle repairs, incisions under tension or with poorly vascularized tissue due to e.g., smoking, radiation or other conditions. 2) Reducing or completely preventing ‘dead space’ between the fascia/muscle and subcutaneous interspace (or some other inter-tissue interface) which can limit to formation of seroma or low pressure hematoma/bleeding, thereby reducing infections or chronic seromas and the need for postoperative drains. 3) Reducing the intraoperative time, effort, and skill to close incisions, under tension or not, via transcutaneous application as well as when used to effect subcutaneous/intermediate layer closure using a bidirectional scaffold placed in a perpendicular direction to approximate the subcutaneous and deep dermal layers of tissue.
[0078] A scaffold as described herein can include a flexible substrate composed of interlocking loops of polymer (or other material) and solid platforms (which can also be referred to as “base elements”) of polymer (or other material) which have holes or other features to facilitate mechanical connection with the loops of the flexible substrate. The loops and platforms can be arranged along horizontal and vertical directions with a repeating pattern of multiple loops followed by a platform. The platforms can be manufactured separately with a directional anchor (which can include one or more spurs/barbs) that permits one way movement into tissue but that resists movement in the opposite direction, thereby allowing the directional anchors to be inserted into tissue so as to anchor the platforms, and by extension the flexible substrate, to multiple locations along a surface of the tissue(s).
[0079] The spurs or barbs of each anchor can be similar to a porcupine quill or a grappling hook with the ability to penetrate and move in one direction into tissue but to resist movement in the opposite direction out of the tissue. This directional preference allows for stabilization of the scaffold/flexible substrate as well as the approximation and fixture of the different layers of the tissue(s). The loops of the flexible substrate in the horizontal and vertical directions can be manufactured to resist stretching and pulling along the plane parallel to the plane of the flexible substrate. The anchors of the platforms couple such resistive parallel forces into the tissue(s) while also resisting movement in the direction perpendicular to the flexible substrate (e.g., resisting forces that can separate opposing tissues, resulting in dehiscence or other unwanted effects).
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[0082] The scaffold of
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[0084] Note that, while the flexible substrate of the scaffolds depicted in
[0085] The materials of the flexible substrate, base elements, and/or anchors can be resorbable, non-resorbable, configured to elute a drug (e.g., an antibiotic to prevent infection, some other drug to promote wound healing), or composed of some material or combination of materials according to an application. Such materials can include polydioxanone, polyglyconate, or polypropylene. The materials will primary be polydioxanone and possible polyglyconate although polypropylene will possibly be an option if permanent material is needed. For example, the base elements and anchor can be made of resorbable materials (e.g., polydioxanone, polyglyconate) while the flexible substrate is composed of a non-resorbable material (e.g., polypropylene) such that the flexible substrate remains in the body following wound healing, so as to provide support to tissues that have grown through it. Alternatively, the rate of resorption of different elements of the scaffold can be tailored (e.g., by adjusting a ratio of a copolymer, by adjusting a degree of branching or mean length of a polymer) according to an application. For example, all of the elements of the scaffold can be composed of resorbable materials (e.g., polydioxanone), but their rates of resorbtion can be specified such that the anchors resorb quickly (e.g., to improve comfort once the initial period of wound healing has occurred, thus reducing the need for fixation provided by the anchors) while the flexible substrate resorbs more slowly (to provide parallel tension support to tissues that have grown through the material of the flexible substrate). For example, antibiotic impregnated polymer can be employed as well as possible slow release drugs that can be added to a transcutaneous unidirectional scaffold or to a subcutaneous scaffold to prevent or reduce infection and/or scarring.
[0086] As shown in
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[0088] The anchors of a scaffold, which include a central ‘shaft’ that terminates in a ‘head,’ can be configured in a variety of ways and have dimensions specified according to a target tissue type (e.g., skin of the face, skin of the body, subcutaneous skin and underlying muscle/fascia). The shaft mechanically couples the head to a base element. The head includes multiple spurs, barbs, or other features to facilitate insertion into and fixation in target tissue.
[0089] In examples where the scaffold is employed unidirectionally on the external surface of skin (e.g., skin of the face), the anchor length can range from 50 to 200 um to allow for less pain on insertion as well as lowering the risk of scarring in the papillary dermis. The size of the scaffold will also vary depending on location. The anchor can have a head width between 0.3 mm and 0.5 mm and a length between 5 mm and 10 mm for use in internal fixation between volumes of tissue (e.g., between skin of the body and underlying muscle/fascia). The anchor can have a head width between 0.1 mm and 0.15 mm and a length between 0.75 mm and 1.25 mm and/or a length between 0.1 mm and 0.2 mm for applications involving skin of the face. The anchor can have a head width between 0.1 mm and 0.15 mm and a length between 2.75 mm and 3.25 mm for applications involving subcutaneous fixation of skin of the face.
[0090] The anchors can be composed of multiple different materials to tailor the resistance or resorption profile, to facilitate manufacturing or insertion into tissue, or to provide some other benefit.
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[0092] As shown in
[0093] An anchor as described herein can be fabricated via a variety of methods. In some examples, the anchor can be formed using injection molding or other techniques to provide the bulk of the material of the anchor. In some example, additional subtractive processes (e.g., laser or mechanical cutting to remove volumes of the anchor material, laser ablation) can be applied to form the barbs or other features of the anchor. This can be done to form geometries that are difficult or impossible to achieve via injection molding or other techniques used to provide initial forming of the anchor, to avoid pre-straining or pre-stressing the barbs as they come out of a mold, to provide for sharper features, to remove material internal to the barbs to allow the barbs to deform more toward the shaft during insertion, or to provide some other benefit.
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[0095] The above detailed description describes various features and functions of the disclosed systems, devices, and methods with reference to the accompanying figures. In the figures, similar symbols typically identify similar components, unless context indicates otherwise. The illustrative embodiments described in the detailed description, figures, and claims are not meant to be limiting. Other embodiments can be utilized, and other changes can be made, without departing from the scope of the subject matter presented herein. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, can be arranged, substituted, combined, separated, and designed in a wide variety of different configurations, all of which are explicitly contemplated herein.
[0096] While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope being indicated by the following claims.