Anatomical defect repair mesh

Abstract

The present invention provides an anatomical defect repair mesh (10) with particular application to hernia repair. The mesh includes a flexible substrate that is shiftable between a collapsed state for percutaneous delivery and an expanded state for covering an anatomical defect, the flexible substrate defining an array of substantially radially extending spokes (18) and an array of bridging struts (22), each bridging strut being disposed between a pair of adjacent spokes and extending obliquely relative to the spokes. The substrate is preferably cut from a single sheet of flexible material.

Description

[Technical field]

[0001] The present invention relates to meshes for repairing anatomical defects such as inguinal hernias, non-inguinal abdominal hernias (e.g., umbilical hernias, ventral hernias, incisional hernias), cardiac and / or vascular defects or injuries, and in particular to repair meshes configured for percutaneous delivery to the site of the anatomical defect. [Background technology]

[0002] Prosthetic meshes for repairing anatomical defects such as hernias, muscle and vascular injuries or defects are well known, and the first generation of these meshes were generally constructed entirely of polypropylene (PP). Although non-absorbable PP meshes are believed to offer advantages over simple sutures such as those used in the Bassini repair technique, initially these meshes were manufactured with small pore sizes and therefore classified as "heavy" meshes. However, such characteristics promoted persistent inflammation and fibrosis, often resulting in significant shrinkage of the mesh. To address such issues, meshes were developed with monofilament threads of different thicknesses running parallel to each other. Further refinements included anisotropic reinforcement with thick threads providing ideal stiffness and proper material deployment, and a higher number of inner thin threads to achieve a lighter mesh, which in turn minimized the amount of foreign material implanted.

[0003] However, limited resistance to biaxial tension, resulting in poor outcomes, has been reported in clinical studies with follow-up periods of up to 5–10 years. Mesh-related adhesions, erosions, and implant fixation have also been reported as complications, especially with PP-based meshes. Despite their limitations and high complication rates, non-degradable surgical meshes are still sold worldwide. Examples include PP meshes such as Marlex™, Prolene™, Prolite™, Atrium™, Trelex™, and Surgipro™, meshes from TransEasyMedical Tech. Co., and expanded polytetrafluoroethylene (e-PTFE) meshes such as Gore-Tex™ and Mycromesh™.

[0004] Additionally, second-generation surgical meshes made from non-degradable biomaterials such as medical-grade PP, polyester, and e-PTFE aimed to mitigate the inflammatory response, shrinkage, and high rates of mesh adhesions associated with first-generation synthetic meshes. To address these issues, PP meshes began to be manufactured with lighter weight weaves, using combinations of synthetic materials and blends, and surface coatings with therapeutic agents.

[0005] Prosthetic meshes classified as "lightweight" have been disclosed that claim benefits such as promoting fibroblast proliferation, promoting macrophage and leukocyte ingrowth, reducing chronic abdominal wall pain and foreign body sensation, biocompatibility, reducing the risk of chronic pain, and providing anisotropic properties similar to abdominal tissue while having sufficient mechanical strength to prevent mesh rupture. Primarily, these prosthetic meshes are composed of a combination of PP and PTFE.

[0006] The main adverse event after hernia repair with prosthetic mesh is adhesion of the mesh to internal organs. The introduction of a foreign body tends to cause an acute inflammatory response, which promotes fibrin deposition and ultimately adhesion of the material to the tissues of the organs. Disclosed solutions include antiblocking hernia patches that combine PP mesh with chitosan, as well as meshes with antiadhesion layers that prevent mesh adhesion, resulting in superior repair strength, reduced hernia recurrence rates, and reduced postoperative complications. In addition, there are meshes that consist of unique antiadhesion and coating layers. Hyaluronic acid, nitinol, titanium, hyaluronic acid carboxymethylcellulose hydrogel, oxidized regenerated cellulose, and chitosan have been used as coating materials incorporated into prosthetic meshes.

[0007] Surgical meshes utilizing Nitinol in the composition have also been disclosed, such as a lightweight PP mesh reinforced with Nitinol, or a woven mesh made of PP, PTFE, or polyester combined with a nickel-titanium shape memory alloy frame. The shape memory alloy frame allows the mesh to curl at low temperatures and return to a flat surface at 37°C, facilitating insertion during laparoscopic surgery. Preclinical studies evaluating the use of Nitinol in self-expanding meshes for laparoscopic hernia repair have been reported in the literature. Advantages include the flexibility of the mesh, which is claimed to prevent plicating and shrinking. It also eliminates the need for mesh fixation, which may prevent chronic pain.

[0008] One of the most challenging complications of prosthetic meshes used in hernia repair is biofilm formation and subsequent bacterial infection. Infection and biofilm formation on the mesh surface significantly impede the repair process, potentially leading to additional surgery and increased morbidity and mortality. These issues could potentially be addressed by designing meshes with antibacterial and antifungal agents.

[0009] The so-called third generation surgical meshes, of allogeneic and xenogeneic origin, are based on biological materials such as acellular collagen matrix scaffolds with or without crosslinking, which promote vascularization and tissue remodeling while providing mechanical support. These biological meshes were introduced to improve the integration of the implant with the host tissue by promoting vascularization and neotissue formation. Many of them were designed to be used at sites of infection or potential infection, where their biodegradable properties could reduce long-term septic complications. However, after implantation of the mesh, the degradation rate and the associated collagen matrix formation are accelerated, leading to a decrease in the elasticity and strength of the newly formed tissue. Advantages compared to first and second generation meshes include better biocompatibility, reduced inflammatory response, and promotion of wound healing response rather than fibrosis formation. Disadvantages include higher cost and lower biomechanical strength, which leads to recurrent hernias.

[0010] To prevent mesh-induced infection, meshes incorporating antibiotic coatings into prosthetic meshes have also been developed. Its advantages are claimed to be biocompatibility, resorbability, and delivery of bioactive antibiotics. Among other biomedical applications, the use of chitosan has also been reported in the art as part of a sustained antimicrobial drug delivery system in combination with a PP mesh. Positive results were obtained suggesting that the use of chitosan for controlled drug delivery could prevent mesh-induced infection.

[0011] Partially absorbable and nonabsorbable meshes are also available.

[0012] Advantages of these meshes include reduced foreign body reaction, reduced mesh adhesions, and enhanced tissue ingrowth. One such prosthetic mesh is the uniplanar tissue repair patch.

[0013] The patch contains a single layer and does not require a mesh fixation layer or an attachment layer. In addition, the patch has a bioabsorbable adhesive barrier on the bottom surface. The improvements claimed are an accelerated rate of tissue integration, a reduced area of ​​biofilm formation, reduced foreign body reaction, reduced manufacturing costs, packaging, ease of sterilization and improved ergonomics of use. However, adhesions still occur.

[0014] It is an object of the present invention to provide an improved repair mesh for anatomical defects, such as inguinal hernias, muscle and / or vascular injuries or defects, which addresses some of the above-mentioned problems of the prior art. Summary of the Invention

[0015] According to a first aspect of the present invention, there is provided an anatomical defect repair mesh comprising a flexible substrate displaceable between a collapsed state for percutaneous delivery and an expanded state for covering an anatomical defect, wherein the substrate comprises an array of substantially radially extending spokes and an array of bridging struts, each bridging strut being disposed between adjacent pairs of spokes and extending obliquely relative to the spokes for at least a portion of the length of the bridging strut.

[0016] Preferably, at least a portion of the spanning struts extend diagonally along the entire length of the strut.

[0017] Preferably, the substrate includes an array of substantially circumferentially extending cross members, each cross member extending between adjacent pairs of spokes.

[0018] Preferably, one or more adjacent spanning struts and one or more adjacent cross members meet at a common point on each spoke.

[0019] Preferably, the density of the spokes, spanning struts and / or cross members varies across the substrate.

[0020] Preferably, the density of the spokes, bridging struts and / or cross members varies such that the area of ​​each space formed between the spokes, bridging struts and / or cross members does not exceed a defined size.

[0021] Preferably, one or more of the radially extending spokes have a varying or variable stiffness along their length.

[0022] Preferably, the substrate is a nonwoven fabric.

[0023] Preferably, the substrate is of unitary construction.

[0024] Preferably, the substrate is additively manufactured.

[0025] Preferably, the substrate is cut from a single sheet.

[0026] Preferably, it includes one or more expansion elements secured to or integrally formed with the substrate.

[0027] Preferably, the one or more expansion elements are removably coupled to the substrate.

[0028] Preferably, the one or more expansion elements are transformable between a collapsed state and an expanded state.

[0029] Preferably, the one or more expansion elements are resiliently deformable.

[0030] Preferably, one or more of the expansion elements includes a bladder adapted to receive and retain an inflation fluid to maintain the substrate in an expanded state.

[0031] Preferably, the repair mesh comprises a circular array of radially extending bladders.

[0032] Preferably, the array of bladders is in fluid communication.

[0033] Preferably, the repair mesh includes an externally accessible valve in fluid communication with the bladder.

[0034] Preferably, the repair mesh includes an umbilical conduit connected between the valve and the bladder.

[0035] Preferably, the repair mesh includes an obturator operable to seal the umbilical conduit to allow removal of the valve.

[0036] Preferably, the repair mesh includes one or more guideways in which the one or more expansion elements are retained.

[0037] Preferably, each guideway comprises a sleeve provided on or within the substrate.

[0038] Preferably, the substrate comprises two or more planar layers overlying one another.

[0039] Preferably, the one or more expansion elements are defined by one or more voids formed between two planar layers.

[0040] Preferably, the sleeve includes an enlarged peripheral edge.

[0041] Preferably, one or more of the spokes includes one or more branches.

[0042] Preferably, the substrate is convex when in the expanded state.

[0043] Preferably, the repair mesh includes one or more tensile reinforcement elements that extend across the concave surface of the substrate, with only opposing ends of the reinforcement elements being secured to the substrate.

[0044] Preferably, the substrate is reversibly displaceable between a collapsed state and an expanded state.

[0045] Preferably, one or more of the spokes includes one or more joints along its length that separate the spoke into two or more articulated sections.

[0046] Preferably, the substrate includes a central region and an outer edge surrounding the central region, with the spokes arranged in a circle around the central region and extending radially outward from the central region toward the outer edge.

[0047] Preferably, the repair mesh includes anchors operable to connect the substrate to tissue.

[0048] Preferably, the substrate defines a radial array of pleats defined by spokes, with adjacent pleats folded over one another to facilitate displacement of the substrate between the collapsed and expanded states.

[0049] Preferably, the substrate comprises a polymer.

[0050] Preferably, the substrate comprises polytetrafluoroethylene.

[0051] Preferably, the repair mesh comprises one or more sensors on or about the substrate.

[0052] Preferably, the repair mesh includes ports along the periphery of the substrate for accommodating anatomical features extending from the anatomical defect site.

[0053] As used herein, the term "lateral" is intended to mean that an element or structural member extends generally perpendicular to other elements.

[0054] As used herein, the term "oblique" is intended to mean that an element or structural member is at an angle relative to another reference element, e.g., extends at an acute angle relative to the other element, as opposed to extending perpendicular to the reference element.

[0055] The present invention will now be described with reference to the accompanying drawings. [Brief description of the drawings]

[0056] [Figure 1] FIG. 1 shows a plan view of a repair mesh for an anatomical defect according to a first embodiment of the present invention. [Diagram 2] FIG. 2 illustrates an enlarged view of a portion of the repair mesh shown in FIG. 1. [Diagram 3] 2 is an enlarged view from above of a central portion of the repair mesh of FIG. 1, illustrating a possible configuration of the central overlap of multiple expansion members that form part of the repair mesh. [Figure 4] 13 shows the placement of expansion members in the central region of the repair mesh as viewed from the underside of the repair mesh. [Diagram 5] 4 shows an alternative perspective view of the arrangement shown in FIG. 3. [Figure 6] 5 shows an alternative perspective view of the arrangement shown in FIG. 4. [Figure 7] 1 shows a plan view of a repair mesh for an anatomical defect according to a second alternative embodiment of the present invention. [Figure 8] 1 shows a plan view of a repair mesh for an anatomical defect according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0057] 1-6 of the accompanying drawings, there is illustrated a repair mesh for an anatomical defect such as an inguinal hernia, generally designated 10, in accordance with a first embodiment of the present invention. The repair mesh 10 may be positioned and secured at a variety of anatomical sites to act as a barrier or reinforcement against damaged tissue, but is particularly intended for use in hernia repair. Moreover, the repair mesh 10 is adapted to be positioned in a minimally invasive manner, such as using laparoscopic or percutaneous techniques, as described in detail below, for example, as disclosed in applicant's prior U.S. Patent US9510926B2, the details of which are incorporated herein. Such means of delivery and placement are well known in the art, and further description is not believed to be necessary for a comprehensive understanding of the construction and operation of the present invention.

[0058] Thus, the repair mesh 10 is displaceable between an expanded state as shown to temporarily reduce the cross-sectional area of ​​the mesh 10 to facilitate the minimally invasive placement techniques described above, and a collapsed state for placement at an anatomical site. Once delivered to an anatomical site, the mesh 10 may be displaced to the expanded state as shown or to a deployed state as described below and secured in any suitable manner over the anatomical defect to provide reinforcement thereto. Thus, the mesh 10 includes a flexible substrate 12, which is preferably circular or elliptical, although other suitable shapes may be employed to facilitate conformance to the anatomical contours of the patient. The substrate 12 defines a central region 14 and an outer edge or periphery 16 surrounding the central region 14. In use, the substrate 12 can be folded into a generally conical or cylindrical configuration with the central region 14 forming the apex of a cone or one end of a cylinder and the outer edge 16 compressed to form the base of the cone or the other end of the cylinder to facilitate delivery, for example, through a percutaneous sheath (not shown).

[0059] The substrate 12 further includes a plurality of spokes 18 formed integrally therewith and arranged in a circular array radiating outward from at or adjacent a central region 14 of the substrate 12 to at or adjacent an outer edge 16 of the substrate 12. The lengths of the spokes 18 may vary, including but not limited to an alternating pattern in which each pair of adjacent spokes 18 includes alternating short and long spokes 18 (i.e., every other spoke is long). Similarly, for an elliptical mesh, the length of the spokes on and adjacent the major axis will be greater than the length of the spokes on and adjacent the minor axis.

[0060] The substrate 12 further includes a plurality of cross members 20 formed integrally therewith and extending between adjacent spokes 18, and a plurality of bridging struts 22 formed integrally therewith and extending diagonally relative to the cross members 20 between adjacent spokes 18. Thus, openings or voids 24 are formed between the spokes 18, the cross members 20 and the bridging struts 22 which, in use, promote tissue ingrowth, thereby enhancing fixation of the repair mesh 10 to the anatomical site.

[0061] In a particularly preferred embodiment, the entire substrate 12 is formed as a single monolithic or integral structure including the spokes 18, cross members 20 and bridging struts 22. For example, the substrate 12 may be laser cut or otherwise formed from a single sheet of material (not shown), such as a sheet of polytetrafluoroethylene, or a sheet of other suitable polymer or polymer composition. Thus, voids 24 are cut from the sheet to leave the interconnected arrangement of spokes 18, cross members 20 and bridging struts 22 that form the substrate 12. The thickness, stiffness and / or other physical and compositional properties of the material may be varied to impart desired mechanical and operational properties to the mesh 10. Alternatively, the substrate may be comprised of two overlapping sheets (not shown). Alternatively, the substrate 12 may be formed by additive manufacturing such as 3D printing, again providing a monolithic or integral structure. By utilizing such manufacturing techniques, in addition to achieving a substrate 12 having a uniform thickness or a substrate 12 having a precisely tailored variable thickness as required, it is possible to precisely tailor the physical configuration of the substrate 12 to produce specific mechanical properties not typically possible with conventional woven meshes.

[0062] The number and / or dimensions of the structural elements of the substrate 12, particularly the spokes 18, cross members 20 and bridging struts 22, may be varied as needed and may vary between different regions of the substrate 12, again to achieve desired physical or operational properties. For example, the substrate 12 may have a higher density of structural elements around the central region 14 and a relatively lower density or number of structural elements toward the outer edge 16. In this manner, the physical properties of the substrate 12 may be tailored, such as having greater mechanical strength for the central region 14 and a relatively lower mechanical strength, and therefore increased flexibility, toward the outer edge 16, increasing the facility, opportunity and / or area or platform for tissue ingrowth and attachment, and subsequently increasing resistance to centripetal forces on the mesh 10, as well as increasing resistance to rotational forces on the mesh 10 via the bridging struts 22. In general, the mesh 10 is intended to be substantially centered over the anatomical defect, and therefore it may be beneficial for the central region 14 to have the greatest mechanical strength, thereby providing the greatest support at the greatest site of anatomical weakness or damage. The dimensions of one or more of the spokes 18, cross members 20, and bridging struts 22 may be varied in different regions of the substrate. For example, the spokes 18 may be reduced in width between the central region 14 and the outer edge 18, again increasing the flexibility of the mesh 10 in its peripheral regions. This may reduce localized pressure points and improve conformance to the patient's local anatomy. Additional or alternative configurations may be employed to achieve desired mechanical properties of the mesh 10. For example, one or more of the spokes 18 may have one or more branches (not shown) and diverge into two or more sections as the spokes 18 radiate toward the outer edge.

[0063] With particular reference to FIG. 2, in the preferred embodiment shown, the substrate is laser cut from a single sheet of polytetrafluoroethylene and defines a circular array of 32 spokes 18. Extending between adjacent pairs of spokes 18 are a plurality of cross members 20, each cross member 20 therefore extending substantially perpendicular to the connected spokes 18, which may also be defined as extending substantially tangentially to its connection point with the respective spoke 18. The radial distance between adjacent cross members 20 may be constant or may vary, for example decreasing toward the outer edge 16, so that the area of ​​all voids 24 does not exceed a certain predetermined size, regardless of the location of the voids 24 on the substrate 12. Also extending between each pair of adjacent spokes 18 are a plurality of bridging struts 22, each linear and disposed at an angle to the spokes 18. In particular, each bridging strut 22 extends outward from the connection point of one of the spokes 18 with one of the cross members 20 to the connection point of the adjacent spoke 18 with the radially adjacent cross member 20. In this manner, each local group of spokes 18, cross members 20, and bridging struts 22 converge at a single point or node 26. The voids 24 are therefore triangular in shape as a result of this geometric arrangement of the structural elements of the substrate 12. The bridging struts 22 preferably extend at an acute angle to the adjacent cross members 20, for example at an angle between 30° and 70°, preferably at an angle of 45°. The bridging struts 22 are preferably straight and thus extend obliquely to the adjacent cross members 20 along the entire length of the bridging struts 22. However, it is also envisioned that the bridging struts 22 may be curved or extend in an arc between adjacent spokes 18.

[0064] The integral formation of the components or portions that form the substrate 12 further provides improved resistance to curling or distortion of the mesh 10 over time when exposed to mechanical and tissue-induced forces.

[0065] To facilitate expansion of the substrate 12 to an expanded state once delivered to the anatomical defect, the mesh 10 preferably includes one or more expansion elements, which in a preferred embodiment are in the form of resiliently deformable ribs 28, preferably extending radially or diametrically across the substrate 12. In a particularly preferred embodiment, and with reference to Figures 3-6, the ribs 28 are formed from a shape memory material such as Nitinol, although other suitable alternatives may be employed, and the plurality of ribs 28 extend diametrically across the substrate 12, converging and past one another at the central region 14. The ribs 28 are spring biased to return to the straightened configuration shown, and therefore, when the mesh 10 is folded for delivery, the ribs 28 must be forcibly deformed against the action of this spring bias, most preferably by folding each diametrically extending rib 28 in half about the central region 14. It will thus be appreciated that once the substrate 12 is deployed from its respective delivery mechanism, such as a percutaneous sheath (not shown), the ribs 28 return to their straightened configuration, thereby acting to spread the substrate 12 to an expanded state for fixation about the anatomical defect. In a particularly preferred embodiment, there are four ribs 28 equally spaced from one another at the 0°, 90°, 180°, and 270° positions. The ribs 28 may have radiopaque markers thereon, preferably at their peripheral extremities (not shown), to allow the mesh 10 to be located during deployment with an appropriate imaging device. Of course, the number and location of the ribs 28 may vary.

[0066] The ribs 28 pass each other at the central region 14, but are preferably not connected to each other. In a particularly preferred arrangement as shown, each rib 28 may have a loop or corresponding feature at its midpoint to form a protrusion in the central region 14. This protrusion effectively presses the central region 14 into the anatomical defect when the mesh 10 is deployed and captured or pinched by adjacent tissues opposing the anatomical defect, such as between the peritoneum and intestine or the opposing lower abdominal wall. This results in a convex shape for the mesh 10, which improves the load-bearing capacity of the mesh 10 and provides greater resistance to downward or outward forces from the anatomical defect, such as abdominal contents in the case of an inguinal hernia. It will be appreciated that other functional alternatives may be employed to establish this convex shape during use.

[0067] The ribs 28 may be secured to the substrate 12 by any suitable means. For example, the mesh 10 may include radially / diametrically extending sleeves (not shown) secured to or integrally formed with one side of the substrate 12, in which the respective ribs 28 are mounted. The ribs 28 may be permanently mounted within the sleeves, thereby remaining part of the implanted mesh 10. In such a configuration, the mesh 10 may be designed such that the ribs 28 form a structural component and provide some mechanical support to the substrate 12, and appropriate modifications may be made thereto. To reduce contact point pressures at the peripheral tips of the ribs 28, the ribs 28 preferably do not extend to the absolute periphery or other edges 16 of the substrate 12.

[0068] Alternatively, the ribs 28 may be releasably retained on the substrate 12, such as within a sleeve or pocket (not shown) as described above, and then separated from the substrate 12 for suitable removal after placement at the anatomical defect site. This may be done before or after the mesh 10 is secured to the anatomical defect site, for example, with sutures, staples, adhesives, or other suitable means, although the mesh 10 is not necessarily routinely secured by such fasteners. This is particularly true when a central tether and anchor (not shown) is incorporated into the mesh 10. If the mesh 10 includes a sleeve (not shown) for retaining the ribs 28, an enlarged opening may be provided at one end of the sleeve to aid in removal of each rib 28 after placement of the mesh 10 at the anatomical defect site.

[0069] It will be appreciated that functional alternatives to the ribs 28 may be employed to transition the mesh 10 from the collapsed state to the expanded state. For example, one or more enclosed chambers, bladders or sleeves may be provided on or integrally formed with the substrate 12, preferably extending diametrically, and inflatable with a liquid or gas to bias the mesh 10 from the collapsed state to the expanded state, as described below in connection with a further embodiment shown in FIG. 8. The inflation liquid or gas may be provided from a pre-filled canister (not shown) or the like. The inflation liquid (e.g., saline) or gas (e.g., CO2, helium, or air) may be passively deflated or may be actively extracted or removed once the mesh 10 is deployed around the anatomical defect. However, it is also envisioned that the inflation liquid or gas may be left in place by incorporating a valve that may provide additional mechanical strength to the substrate. The sleeve may be allowed or configured to deflate instantly or actively, or over an extended or period of time. For example, a sleeve (not shown) may remain inflated and supportive for a period of time sufficient to allow tissue ingrowth and thereby stabilization of the mesh 10, after which the sleeve may gradually collapse, reducing stiffness and support and allowing tissue ingrowth to assume the support function. This gradual loss of stiffness prevents pressure points and tenderness. The sleeve may be rolled or otherwise compressed when the mesh 10 is in the collapsed state, and may be expanded upon delivery to the anatomical site to expand the mesh 10 and provide support and structure thereto. A hardenable liquid may be used as the expansion liquid, which hardens after displacing the mesh 10 to the expanded state. A liquid containing a radiographic dye or the like may be used to allow imaging of the mesh 10 during the placement procedure.

[0070] An alternative mechanism for achieving temporary stability of the mesh 10 during the initial period of deployment, e.g., the first month or two until the mesh 10 heals due to tissue ingrowth, is to use magnesium for the ribs 28 or provide alternative magnesium struts (not shown) or the like. It is well recognized and established that magnesium has a very predictable dissolution rate in saline and body solutions, with the magnesium ribs or struts completely dissolving and resorbing within a few months. The time it takes for the magnesium ribs to be resorbed is determined by the thickness of the ribs, which are preferably contained within an open sleeve (not shown) on the substrate 12 so that body fluids are exposed to the ribs or struts. This further eliminates the need to staple or glue or secure the mesh 10 at the time of implantation. Once the magnesium ribs or struts are resorbed, long-term compression and pain may be avoided. Of course, it will be understood that other suitable materials may be selected, including, but not limited to, suitable polymers such as polytetrafluoroethylene (PTFE).

[0071] The mesh 10 may include anchors (not shown) for tethering the substrate 12 in place, for example as disclosed in applicant's earlier US Patent US9510926B2. Such anchor cords are operable to position the central region 14 of the mesh 10 over the deep inguinal ring during inguinal hernia repair, preventing migration of the mesh 10. The anchors (not shown) may be of any suitable configuration, for example the central region 14 may have a tether or anchor point formed from a high tension tether or cord (not shown) that prevents the mesh 10 from migrating away from the hernia or abdominal weakness. A bar or tab (not shown) may be located at the free end of the tether that defines an anchor for tethering the mesh 10 to a point outside the external inguinal ring (in the subcutaneous fat). The bar or tab may be made of a permanent material (e.g. Nitinol or PTFE) that may be rigid or flexible, or may be made of a biodegradable material (e.g. magnesium based calcium phosphate or polylactide or bioceramics, etc.).

[0072] 7, there is illustrated a repair mesh for an anatomical defect such as an inguinal hernia, generally designated 110, in accordance with an alternative embodiment of the present invention. In this alternative embodiment, like components are labeled with like reference numerals and perform like functions unless otherwise noted.

[0073] In this embodiment, the mesh 110 includes a substrate 112, which is again formed as a single monolithic or one-piece piece, preferably laser cut or manufactured by other suitable means from a sheet of a suitable material such as PTFE. The substrate 112 defines a central region 114, an outer edge 116, and an array of spokes 118 extending radially therebetween. Extending between adjacent spokes 118 are a plurality of diagonally oriented bridging struts 122. The mesh 110 does not incorporate cross members as in the mesh 10 of the previous embodiment. However, it can be seen that the substrate 112 again has a higher density of material towards the central region 114, with the distance between the spokes 118 and the bridging struts 122 increasing towards the periphery. As detailed above, this ensures that the central region 114 has a higher resistance to deformation and therefore a greater load bearing capacity. The mesh 110 may again be provided with suitable expansion means (not shown), such as the shape memory ribs of the first embodiment, but other suitable functional alternatives may be employed.

[0074] 8, there is illustrated a repair mesh for anatomical defects such as inguinal hernias, muscle or vascular defects or injuries, in accordance with a third embodiment of the present invention, generally designated as 210. In this third embodiment, like components are given like reference numerals and serve like functions unless otherwise noted.

[0075] The mesh 210 includes a substrate 212, again constructed from a single monolithic or integral piece, preferably formed from two or more laminated layers, each laser cut from a sheet of a suitable material such as PTFE, and the two or more layers suitably secured in face-to-face engagement, preferably bonded together by heat welding or other suitable means, as described below. As with the previous embodiment, the substrate 212 is planar and extends from a central region 214 to an outer edge 216, and includes a circular array of spokes 218, the number of which may vary as needed or for a particular anatomical application. Extending between adjacent pairs of spokes 218 are a plurality of cross members 220 that extend substantially perpendicular to the connected spokes 218, as previously described. The radial distance between adjacent cross members 20 may be constant or may vary. Also extending between each pair of adjacent spokes 218 are a plurality of bridging struts 222, each of which is linear and disposed at an angle to the spokes 218. Each bridging strut 22 preferably extends outwardly from a connection point between one of the spokes 218 and one of the cross members 220 to a connection point between an adjacent spoke 218 and a radially adjacent cross member 220. A gap 224 is formed therebetween and is triangular in shape as a result of the geometric arrangement of the structural elements of the substrate 212. The bridging struts 222 preferably extend at an acute angle to the adjacent cross members 220, for example at an angle between 30° and 70°, and more preferably at an angle of 45°.

[0076] As shown in FIG. 8, to transition the substrate 212 between a collapsed state (not shown) and an expanded state, the mesh 210 includes an array of expansion elements, preferably in the form of inflatable bladders 228 extending radially outwardly at or adjacent the center of the mesh 210. In the illustrated embodiment, there is a circular array of radially extending bladders 228 that converge at the center of the mesh 210 and are in fluid communication such that all of the bladders 228 may be inflated / deflated simultaneously. However, it is envisioned that the bladders 228 may be inflated / deflated individually or in groups. The mesh 210 includes a port in the form of a valve 50 secured to the substrate 212 and located at the center of the mesh 210, the valve being in fluid communication with the interior of the bladders 228. The valve 50 thus provides a means for introducing and / or removing inflation fluid from the bladders to transition the mesh 210 between the expanded and collapsed states. Thus, the valve 50 may be releasably connected to a suitable source of inflation liquid, such as, for example, a manometer syringe, a gas cartridge, hospital gas supply (CO, O), etc. The valve 50 may be used, for example, to continuously inflate and deflate the bladder 228 until deployment of the mesh 210 is deemed optimal.

[0077] It is also envisioned that while the valve 50 is secured to the substrate 212, an umbilical-type conduit (not shown) may be connected to the substrate in fluid communication with the bladder 228, with the valve 50 connected to the opposing free end of the conduit. This may improve access to the valve 50 during insertion of the mesh 210, or, if left in place, may allow the valve 50 to be placed in an anatomically preferred location away from the mesh, or may allow the use of a larger valve 50 than would be possible or desirable if secured directly to the substrate. The use of an umbilical conduit and remote valve also allows the valve to be removed after the mesh 210 has been expanded, for example, by simply cutting the valve off. In such a configuration, a suitable closure (not shown), such as a band or clip, may be provided on the umbilical conduit and tightened or otherwise clamped to the conduit to close the conduit prior to removal of the valve.

[0078] It is also envisioned that the valve again remains in place on the umbilical conduit to allow post-operative adjustment of the pressure in the bladder 228 to fine-tune the stiffness of the mesh 210. The valve may also function as an anchor as described above to hold the mesh 210 in position over the anatomical site to be repaired. Alternatively, the umbilical conduit may be bifurcated so that it includes a first leg that is provided with a valve and a parallel second leg that includes an anchor.

[0079] The inflation liquid may be a fluid or gas, such as, for example, carbon dioxide, air (which is radiolucent), liquid and / or gel silicone, liquid and / or curable polymer, or other suitable fluid, whether or not biocompatible and / or biodegradable. The bladder 228 is preferably fluid impermeable to permanently contain the inflation fluid, but may also be provided with a level of porosity to allow the bladder 228 to contract over a period of time, thereby avoiding long-term pressure points. The bladder 228 may also be inflatable to different pressures or of different dimensions to allow for tuning of the stiffness of the mesh 210 when in an expanded state. Depending on the inflation fluid employed, the bladder 228 may also be provided as a separate housing captured or contained within an outer sleeve (not shown) provided on or integrally formed with the substrate 212 to provide a space surrounding the bladder 228 in which any escaping inflation fluid may be retained to avoid contamination of the surrounding tissue. This configuration may be achieved by providing the array of bladders 228 as a separate piece and capturing or sandwiching it between two layers or laminates that are secured together with the bladders 228 therebetween to form the substrate 212. The two layers are secured together with heat and / or pressure, heat welded, or otherwise secured face-to-face to one another, leaving a space immediately surrounding each bladder 228 unsecured to define the aforementioned space or sleeve surrounding the bladder 228. Of course, it will be appreciated that other suitable means of manufacturing the mesh 210 may be employed to achieve such a physical configuration.

[0080] The mesh 10;110;210 may be pleated, for example, in portions that are foldable relative to one another about a fold line defined by the spokes 18;118;218 to move the mesh 10;110;210 between an expanded state and a folded state similar to the movement of an umbrella canopy. The mesh 10;110;210 may include one or more sensors (not shown) for monitoring one or more parameters, such as monitoring pressure at an anatomical site, monitoring biomarkers or other signs of disease or infection, or monitoring other useful parameters or bio-signs. Such sensors include, but are not limited to, biochemical and metabolic parameters, physical parameters (temperature, tension), electronic detection of cardiovascular parameters, and wireless transmission of data. Power for such sensors and data transmission may be obtained by external wireless power or mechanical compression within the abdomen. The mesh 10;110 may also include a second or further layer (not shown) that partially or completely covers the substrate 12;112;212.

[0081] The mesh 10;110;210 may be modified to include an opening or portal (not shown) in the center of the mesh 10;110;210 to allow for the passage of one or more surgical instruments during placement and / or removal of the mesh 10;110;210. For example, prior to full placement, the portal of the mesh 10;110;210 may be threaded with some form of support or support (not shown), which may be utilized to create a surgical space or cavity around the mesh 10;110;210 that may aid in placement and / or visualization by fiber optic imaging or the like. This support may take the form of, for example, a deployable or inflatable canopy or the like, which may be placed directly adjacent / above the mesh 10;110;210 and deployed to create the necessary space to facilitate improved / complete expansion of the mesh 10;110;210 from a collapsed state utilized to deliver the mesh 10;110;210 to the anatomical repair site. This canopy (not shown) may be an integral part of the mesh 10;110;210 or may be a separate part that can be retrieved through a portal (not shown) once the mesh 10;110;210 is fully deployed.

[0082] As detailed above, the mesh 10;110;210 is preferably domed or convex to provide structural rigidity during operation and prevent the mesh 10;110;210 from collapsing under pressure / movement, etc. To further refine this aspect, the mesh 10;110;210 may include one or more tension members (not shown) or reinforcing elements such as woven fabrics that extend across the underside (concave) of the mesh 10;110;210, preferably extending diametrically and dimensioned to be in tension when the mesh 10;110;210 is in the expanded state. These members thus act to resist collapsing or inversion of the mesh 10;110;210 under load, e.g., to better resist pressure from abdominal contents.

[0083] The design of the mesh 10;110;210 of the present invention allows for fine tuning of the above mentioned properties, such as variable flexibility between the central region 14;114;214 and the outer edges 16;116;216, allowing for improved tissue adhesion and resistance to migration and / or collapse after fixation in the anatomical defect. The oblique orientation of the bridging struts 22;122;222 prevents the mesh 10;110 from rotating once embedded by tissue ingrowth. The cross members 20;120;220 in combination with the bridging struts 22;122;222 also prevents embedding of the mesh 10;110;210, especially towards the central region 14;114;214, once embedded by tissue ingrowth. Furthermore, the diagonal orientation of the bridging struts 22;122;222, in combination with the horizontally or laterally extending cross members 20;120;220, provides maximum frictional resistance to inward movement (inward folding / embedding) of the mesh 10;110;210, facilitating tissue ingrowth and fixation of the mesh 10;110;210 at the site of the anatomical defect.

[0084] Thus, the repair mesh 10;110 of the present invention precisely establishes improved mechanical properties that may be varied by design across different regions of the mesh 10;110 to provide improved performance.

[0085] The invention is not limited to the embodiments described herein, which can be modified or varied without departing from the scope of the invention.

Claims

1. An anatomical defect repair mesh comprising a flexible substrate displaceable between a folded state for transcutaneous delivery and an expanded state for covering an anatomical defect, wherein the substrate comprises a substantially radially extending arrangement of spokes and an arrangement of bridging struts, the bridging struts being provided between adjacent pairs of spokes and extending obliquely to the spokes over at least a portion of the length of the bridging struts.

2. The repair mesh according to claim 1, wherein at least some of the bridging struts extend diagonally along the entire length of the struts.

3. The repair mesh according to claim 1, wherein the base material includes an arrangement of transverse members substantially extending in the circumferential direction, the transverse members each extending between adjacent pairs of spokes.

4. The repair mesh according to claim 3, wherein one or more adjacent bridging struts and one or more adjacent transverse members intersect at a common point on their respective spokes.

5. The repair mesh according to claim 1, wherein the density of the spokes, the bridging struts and / or transverse members varies across the base material.

6. The repair mesh according to claim 1, wherein two or more of the spokes are of different lengths.

7. The repair mesh according to claim 5, wherein the density of the spokes, the bridging struts and / or the transverse members is varied so that the area of ​​the individual spaces formed between the spokes, the bridging struts and / or the transverse members does not exceed a predetermined size.

8. The repair mesh according to claim 1, wherein one or more of the radially extending spokes have a rigidity that changes or is variable along their length.

9. The repair mesh according to claim 1, wherein the base material is a nonwoven fabric.

10. The repair mesh according to claim 1, wherein the base material has an integral structure.

11. The repair mesh according to claim 1, wherein the base material is manufactured by addition.

12. The repair mesh according to claim 1, wherein the substrate is cut from a single sheet.

13. The repair mesh according to claim 1, comprising one or more extension elements fixed to or integrally formed with the substrate.

14. The repair mesh according to claim 13, wherein one or more extension elements are detachably connected to the base material.

15. The repair mesh according to claim 13, wherein one or more extension elements are deformable between a folded state and an extended state.

16. The repair mesh according to claim 13, wherein one or more of the extension elements are elastically deformable.

17. The repair mesh according to any one of claims 13 to 16, wherein one or more expansion elements include a bladder adapted to receive and hold an expansion fluid in order to maintain the substrate in the expanded state.

18. The repair mesh according to claim 17, comprising a circular arrangement of radially extending bladder.

19. The repair mesh according to claim 18, wherein the arrangement of bladder is in fluid communication.

20. The repair mesh according to claim 17, comprising an externally accessible valve that is in fluid communication with the bladder.

21. The repair mesh according to claim 20, comprising an umbilical conduit connected between the valve and the bladder.

22. The repair mesh according to claim 20, comprising a closure device operable to seal the umbilical conduit in order to allow the removal of the valve.

23. The repair mesh according to claim 13, comprising one or more guideways in which one or more extension elements are held.

24. The repair mesh according to claim 23, wherein each guideway includes a sleeve provided on or within the substrate.

25. The repair mesh according to claim 24, wherein the sleeve includes an enlarged peripheral end.

26. The repair mesh according to claim 13, wherein the substrate includes two or more planar layers that overlap each other.

27. The repair mesh according to claim 26, wherein one or more extension elements are defined by one or more voids formed between two of the planar layers.

28. The repair mesh according to claim 1, wherein one or more of the spokes include one or more branching portions.

29. The repair mesh according to claim 1, wherein the substrate is convex when in the expanded state.

30. The repair mesh according to claim 27, wherein the repair mesh includes one or more tensile reinforcing elements extending across the concave surface of the substrate, and only the opposing ends of the tensile reinforcing elements are fixed to the substrate.

31. The repair mesh according to claim 1, wherein the base material is reversibly displaceable between the folded state and the extended state.

32. The repair mesh according to claim 1, wherein one or more of the spokes include one or more joints along their length that separate the spoke into two or more joints.

33. The repair mesh according to claim 1, wherein the base material includes a central region and an outer edge surrounding the central region, and the spokes are arranged in a circular pattern around the central region and extend radially outward from the central region toward the outer edge.

34. The repair mesh according to claim 1, wherein the base material defines a radial arrangement of pleated portions defined by the spokes, and adjacent pleated portions are folded relative to each other to facilitate the displacement of the base material between the folded state and the extended state.

35. The repair mesh according to claim 1, comprising an anchor that is operable to connect the substrate to the tissue.

36. The repair mesh according to claim 1, wherein the substrate comprises a polymer.

37. The repair mesh according to claim 1, wherein the base material contains polytetrafluoroethylene.

38. The repair mesh according to claim 1, further comprising one or more sensors on or near the substrate.

39. The repair mesh according to claim 1, comprising a port along the periphery of the substrate for accommodating anatomical features extending from the anatomical defect site.

Images