Compliance control stitching with multiple axis stitch pattern

Abstract

Methods and apparatuses for forming grafts having a very high porosity, so that tissue may contact adjacent tissue directly through the pores or openings, while retaining a high degree of strength by forming a reinforcing stitching pattern without piercing the substrate. For example, described herein are grafts and methods of forming them using a substrate having a plurality of pre-formed holes or pores that are relatively large. Different stitches (e.g., lock stitches) may share the same hole or holes through the substrate. The grafts may be formed without piercing the substrate by passing through the pre-formed holes.

Description

COMPLIANCE CONTROL STITCHING WITH MULTIPLE AXIS STITCH PATTERNCLAIM OF PRIORITY

[0001] None.INCORPORATION BY REFERENCE

[0002] All publications and patent applications mentioned in this specification are herein incorporated by reference in their entirety to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference.FIELD

[0003] The apparatuses and methods described herein relate to stitch patterns useful for sewing or embroidering into biotextile or medical textile substrates. More particularly, described herein are compliance-control stitch patterns that modulate the strength and stiffness of substrates under certain load conditions, useful in surgical grafts and medical textiles.BACKGROUND

[0004] Soft tissues within a body may benefit from repair or reinforcement due to a variety of reasons such as disease, enhancement, or trauma. An implant or graft may be used to repair or reinforce a soft tissue, such as an unhealthy or modified tissue in the body. The tissue may, for example, be tissue that is no longer able to maintain its shape or physiological function such as a hernia or a tissue for which a shape or size change is desired such as breast size or shape change due to breast enhancement or breast reconstruction.

[0005] Some implant grafts include a substrate embroidered with a reinforcing thread. In some cases, the thread is arranged in a stitch pattern that alters the physical properties of the substrate to improve its performance when implanted into a patient’s body. For example, the thread may be woven into a pattern that reinforces the strength of the substrate and also provides a certain degree of compliance. However, the stitching process creates holes in the substrate that may weaken the substrate, especially if the substrate has an unstable construction or rigidity.- 1 - SG Docket No.: 14450-715.601

[0006] Therefore, there is a need for improved embroidered surgical repair materials and embroidery techniques for forming surgical repair materials.SUMMARY OF THE DISCLOSURE

[0007] Described herein are surgical grafts that include a compliance control pattern with multiple axis stitch pattern embroidery. The embroidery may modulate the tensile strength and compliance of the substrate. For example, the compliance control pattern may provide multiple directional control of the compliance of the substrate. The embroidered substrates may be, or be part of, a soft tissue repair graft, such as a repair scaffold, a patch, or a mesh for repairing a hernia or for breast reconstruction.

[0008] The multiple axis embroidery pattern includes multiple stitch patterns overlaid onto each other such that the stitch patterns intersect at nodes where lines of the stitch patterns run parallel to different axes. In at least some of the intersections, the threads of the stitch patterns share holes within the substrate. This construction is found to increase the strength of the substrate more than other reinforcing embroidery patterns.

[0009] According to one example, a surgical graft includes: a substrate; a multiple axis embroidery pattern sewn into the substrate, the multiple axis embroidery pattern comprising first, second, and third stitch patterns, wherein the first stitch pattern overlays the second stitch pattern, and the third stitch pattern overlays the first and second stitch patterns; wherein the first stitch pattern includes first rows arranged in parallel to a first axis, the second stitch pattern includes second rows arranged in parallel to a second axis, and the third stitch pattern includes third rows arranged in parallel to a third axis, wherein the first, second, and third axes are nonparallel to each other; and wherein the first, second and third stitch patterns share holes in the substrate, wherein, in each shared holes of the substrate, the second stitch pattern at least partially envelops the first stitch pattern, and the third stitch pattern at least partially envelops the first and second stitch patterns. The multiple axis embroidery pattern may form equilateral triangles. A length of each side of the equilateral triangles may range from about 2 millimeters (mm) and 8 mm. The holes may be arranged in a pattern of offset rows in the substrate. The surgical graft may have a maximum load resistance of 160 N or greater. The multiple axis embroidery pattern may include a fourth stitch pattern including fourth rows arranged in parallel to a fourth axis that is nonparallel to the first, second, and third axes, wherein the first, second, third and fourth stitch patterns share at least a subset of the holes in the substrate, and wherein, in each shared subset of holes, the fourth stitch pattern overlays and at least partially envelops the first, second, and third stitch patterns. At least a portion of the first, second, and third stitch patterns may be entangled with each other within the shared - 2 - SG Docket No.: 14450-715.601holes. Upper and lower threads of each of the first, second, and third stitch patterns may interlock within the shared holes. The substrate may include multiple layers. The substrate may include one or more layers of a collagen sheet, a hyaluronic acid sheet, a knit, a weave, a braid, a nonwoven material, a meltblown material, an electrospun sheet, a biotextile material, and / or a latex material.

[0010] According to another example, a method of forming compliance control, multiple axis embroidery pattern in a substrate includes: sewing a first stitch pattern into the substrate, wherein the first stitch pattern comprises a first rows of lines arranged in parallel to a first axis; sewing a second stitch pattern into the substrate over the first stitch pattern, wherein the second stitch pattern comprises a second rows of lines arranged in parallel to a second axis that is non-parallel to the first axis, wherein the second stitch pattern is sewn such that the first and second stitch patterns share a holes in the substrate, wherein, in each shared holes of the substrate, the second stitch pattern at least partially envelops the first stitch pattern; and sewing a third stitch pattern into the substrate over the first and second stitch patterns, wherein the third stitch pattern comprises a third rows of lines arranged in parallel to a third axis that is non-parallel to the first and second axes, wherein the third stitch pattern is sewn such that the first, second and third stitch patterns share a holes in the substrate, wherein, in each shared holes of the substrate, the third stitch pattern at least partially envelops the first and second stitch patterns. The first rows of lines may be equally distanced from each other, the second rows of lines are equally distanced from each other, and the third rows of lines are equally distanced from each other. The multiple axis embroidery pattern may form equilateral triangles. A length of each side of the equilateral triangles may range from about 2 millimeter (mm) and 8 mm. The embroidered substrate may have a maximum load resistance of 160 N or greater. The method may further include sewing a fourth stitch pattern into the substrate over the first, second and third stitch patterns wherein the third stitch pattern comprises a fourth rows of lines arranged in parallel to a fourth axis that is non-parallel to the first, second and third axes, wherein the first, second, third and fourth stitch patterns share at least a subset of the holes in the substrate, and wherein, in each shared subset of holes, the fourth stitch pattern overlays and at least partially envelops the first, second, and third stitch patterns. At least a portion of the threads of the first, second, and third stitch patterns may be entangled with each other within the shared holes. Upper and lower threads of each of the first, second, and third stitch patterns may interlock within the shared holes. The substrate may include multiple layers.

[0011] According to a further example, a surgical graft includes: a substrate; a multiple axis embroidery pattern sewn into the substrate, the multiple axis embroidery pattern- 3 - SG Docket No.: 14450-715.601comprising first, second, and third stitch patterns, wherein the first stitch pattern overlays the second stitch pattern, and the third stitch pattern overlays the first and second stitch patterns; wherein the first stitch pattern includes a first rows arranged in parallel to a first axis, the second stitch pattern includes a second rows arranged in parallel to a second axis, and the third stitch pattern includes a third rows arranged in parallel to a third axis, wherein the first, second, and third axes are nonparallel to each other; wherein the first, second and third stitch patterns share a holes in the substrate, wherein, in each shared holes of the substrate, the second stitch pattern at least partially envelops the first stitch pattern, and the third stitch pattern at least partially envelops the first and second stitch patterns; and wherein the multiple axis embroidery pattern forms a equilateral triangles.

[0012] In particular, described herein are surgical grafts formed to have a very high permeability while retaining a high strength, by embroidering one or more patterns though preexisting holes in the substate, without (or without substantially) piercing the substrate, which may result in stress and wear on the substrate, potentially weaking it and / or reducing its effective lifetime.

[0013] For example, described herein are surgical grafts, comprising: a substrate comprising a repeating pattern of pre-existing holes through the substrate, the holes having a diameter of between 2 and 12 mm; an embroidery pattern sewn into the substrate through the pre-existing holes so as not to form local stress concentrators in the substrate, the embroidery pattern comprising first, second, and third stitching patterns, wherein the first stitch pattern overlays the second stitch pattern, and the third stitch pattern overlays the first and second stitch patterns; wherein the first stitch pattern includes a plurality of first rows arranged in parallel, the second stitch pattern includes a plurality of second rows arranged in parallel, and the third stitch pattern includes a plurality of third rows arranged in parallel, wherein the first, second, and third rows are not parallel to each other; and wherein the first, second and third stitch patterns pass through the substrate through the pre-existing holes at an edge region of the pre-existing holes, leaving an unobstructed zone through a center of the pre-existing holes.

[0014] In some examples the first, second and third stitch patterns may pass through the substrate only through the pre-existing holes at the edge region of the pre-existing holes. Alternatively, in some cases, greater than 70% (e.g., 75% or greater, 80% or greater, 85% or greater, 90% or greater, 95% or greater, 97% or greater, 98% or greater, 99% or greater, etc.) of the first, second and third stitch patterns pass through the substrate only through the preexisting holes at the edge region of the pre-existing holes.- 4 - SG Docket No.: 14450-715.601

[0015] In some cases, each of the first, second and third stitch patterns form a lock stitch pattern within the pre-existing holes. In some examples each of the first, second and third stitch patterns forms a plurality of equilateral triangles. A length of each side of the plurality of equilateral triangles may range from about 2 millimeters (mm) and 8 mm. The holes of the plurality of pre-existing holes may be arranged in a pattern of offset rows in the substrate. The plurality of pre-existing holes may be any appropriate shape, e.g., circular, non-circular (oval, rectangular, triagonal, square, pentagonal, hexagonal, etc.). The surgical graft may have a maximum load resistance of 160 N or greater (e.g., 165 N or greater, 170 N or greater, 175 N or greater, 180 N or greater, 185 N or greater, 190 N or greater, 200 N or greater, 210 N or greater, etc.).

[0016] The embroidery pattern may include a fourth stitch pattern sewn into the substrate through the pre-existing holes so as not to form local stress concentrators in the substrate, the fourth stitch pattern including a plurality of fourth rows may be arranged in parallel to a fourth axis that is nonparallel to the first, second, and third rows. At least a portion of each of the first, second, and third stitch patterns may pass through the pre-existing holes and may be arranged around the periphery of the pre-existing holes.

[0017] In any of these grafts, the upper and lower threads of each of the first, second, and third stitch patterns may interlock within the shared plurality of holes.

[0018] The substrate may include multiple layers. For example, the substrate may include one or more layers of: a collagen sheet, a hyaluronic acid sheet, a knit, a weave, a braid, a nonwoven material, a meltblown material, an electrospun sheet, a biotextile material, and / or a latex material.

[0019] Also described herein are surgical grafts comprising: a substrate comprising a repeating pattern of pre-existing holes through the substrate, the holes having a diameter of between 2 and 12 mm; an embroidery pattern sewn into the substrate through the pre-existing holes so as not to pierce the substrate and form local stress concentrators in the substrate, the embroidery pattern comprising a stitching pattern formed of lock stiches within the preexisting holes, and wherein the embroidery pattern passes through the substrate through the pre-existing holes at an edge region within the pre-existing holes, leaving an unobstructed zone through a center of the pre-existing holes.

[0020] The embroidery pattern may pass through the substrate only through the preexisting holes at an edge region of the pre-existing holes. Alternatively, in some cases, greater than 70% (e.g., 75% or greater, 80% or greater, 85% or greater, 90% or greater, 95% or greater, 97% or greater, 98% or greater, 99% or greater, etc.) of the first, second and third- 5 - SG Docket No.: 14450-715.601stitch patterns pass through the substrate only through the pre-existing holes at the edge region of the pre-existing holes.

[0021] In any of these grafts, the pre-existing holes may be punched, cut, burned (e.g., laser cut) or otherwise formed into the substrate prior to embroidering / sewing. In some cases, the substrate may be fabricated to include these holes (pores). The holes may be the same size or different sizes. The holes may be arranged in any appropriate pattern. For example, the plurality of pre-existing holes may be arranged in a pattern of offset rows in the substrate. As mentioned, the pre-existing holes may be formed of any shape within the defined size ranges. For example, the plurality of pre-existing holes may be circular. The plurality of pre-existing holes may be arranged in a pattern of offset rows in the substrate. The plurality of preexisting holes may be any appropriate shape, e.g., circular, non-circular (oval, rectangular, triagonal, square, pentagonal, hexagonal, etc.). The surgical graft may have a maximum load resistance of 160 N or greater (e.g., 165 N or greater, 170 N or greater, 175 N or greater, 180 N or greater, 185 N or greater, 190 N or greater, 200 N or greater, 210 N or greater, etc.).

[0022] The substrate may include multiple layers. The substrate may include one or more layers of: a collagen sheet, a hyaluronic acid sheet, a knit, a weave, a braid, a nonwoven material, a meltblown material, an electrospun sheet, a biotextile material, and / or a latex material.

[0023] Also described herein are methods of forming a graft having a plurality of preexisting holes. For example, a method of forming a surgical graft may include: sewing a stitch pattern into a substrate, the substrate comprising a repeating pattern of pre-existing holes through the substrate, the holes having a diameter of between 2 and 12 mm, wherein stitch pattern is sewn into the substrate through the pre-existing holes without piercing the substrate so as not to form local stress concentrators in the substrate, the stitch pattern comprising lock stiches within the pre-existing holes, and wherein the stich pattern passes through the substrate through the pre-existing holes at an edge region within the pre-existing holes, leaving an unobstructed zone through a center of the pre-existing holes. The stitch pattern may comprise a first, a second, and a third stitching pattern, wherein the first stitch pattern overlays the second stitch pattern, and the third stitch pattern overlays the first and second stitch patterns, and wherein the first stitch pattern includes a plurality of first rows arranged in parallel, the second stitch pattern includes a plurality of second rows arranged in parallel, and the third stitch pattern includes a plurality of third rows arranged in parallel, wherein the first, second, and third rows are not parallel to each other. At least a portion of the threads of the first, second, and third stitch patterns may be entangled with each other within the shared plurality of holes. An upper and a lower thread of each of the first, second,- 6 - SG Docket No.: 14450-715.601and third stitch patterns may interlock within the shared plurality of holes. The substrate may include multiple layers.

[0024] It should be appreciated that all combinations of the foregoing concepts and additional concepts discussed in greater detail below (provided such concepts are not mutually inconsistent) are contemplated as being part of the inventive subject matter disclosed herein and may be used to achieve the benefits described herein.

[0025] The process parameters and sequence of steps described and / or illustrated herein are given by way of example only and can be varied as desired. For example, while the steps illustrated and / or described herein may be shown or discussed in a particular order, these steps do not necessarily need to be performed in the order illustrated or discussed. The various example methods described and / or illustrated herein may also omit one or more of the steps described or illustrated herein or include additional steps in addition to those disclosed.

[0026] All of the methods and apparatuses described herein, in any combination, are herein contemplated and can be used to achieve the benefits as described herein.BRIEF DESCRIPTION OF THE DRAWINGS

[0027] A better understanding of the features and advantages of the methods and apparatuses described herein will be obtained by reference to the following detailed description that sets forth illustrative embodiments, and the accompanying drawings of which:

[0028] FIGS. 1 A and IB illustrate perspective and closeup views of an example stitch pattern.

[0029] FIG. 1C illustrates a plan view of an example stitch pattern sewn into winding pattern, such as in a substrate.

[0030] FIGS. 2A-2F illustrate an example of two overlaid stitch patterns.

[0031] FIGS. 3A and 3B illustrate an example of forming an embroidery pattern having a square grid construction.

[0032] FIGS. 4A-4C illustrate an example of forming an embroidery pattern having a triaxial construction.

[0033] FIGS. 5A-5C illustrate example close-up views of one of the stitch locations of the triaxial construction FIGS. 4A-4C.

[0034] FIGS. 6 A and 6B illustrate simplified plan views of the square grid pattern of FIGS. 3A-3B and the triaxial pattern of FIGS. 4A-5C.- 7 - SG Docket No.: 14450-715.601

[0035] FIGS. 7A and 7B illustrate plan views of the channels formed in a substrate using the square grid embroidery of FIGS. 3A-3B and the triaxial pattern of FIGS. 4A-5C.

[0036] FIGS. 8A-8D illustrate example graphs comparing the strength of the square grid embroidery of FIGS. 3A-3B and the triaxial pattern of FIGS. 4A-5C.

[0037] FIGS. 9A-9D illustrate an example of forming an embroidery pattern having a quad-axial construction.

[0038] FIGS. 10 A- 10C illustrate an example of a non-piercing embroidery pattern for a substrate as described herein.

[0039] FIG. 11 shows an enlarged view of a portion of a graft formed by embroidering through a plurality of pre-formed stitch patterns without piercing the substrate forming a highly porous graft.

[0040] FIG. 12 shows a perspective view of a graft having the stitching pattern shown in FIG. 11.DETAILED DESCRIPTION

[0041] Described herein are methods and apparatuses (e.g., devices and systems, and in particular surgical grafts) that include embroidery patterns having a multiple axis arrangement. The multiple axis embroidery pattern includes multiple stitch patterns overlaid onto each other in a manner to share holes in a substrate. The multiple axis embroidery pattern imparts greater strength to the substrate compared to other reinforcing embroideries. The multiple axis embroidery pattern further provides an efficient use of embroidery material and minimizes the number of holes created in the substrate, thereby allowing the substrate to maintain more of its integrity. Also described herein are methods and apparatuses for forming grafts having a very high porosity, so that tissue may contact adjacent tissue directly through the pores or openings, while retaining a high degree of strength by forming the reinforcing stitching pattern (embroidery pattern) without piercing the substrate, e.g., stitching only through the pre-formed openings.

[0042] In general, embroidery can alter the compliance and strength of a substrate. The alterations may be directional or isotropic in nature. For many substrates, the process of embroidery pierces the substrate material and creates new full-thickness holes or channels. These channels can change the compliance of the substrate and may weaken the substrate. For many substrates, the more channels / holes that are created in the substrate, the weaker the substrate may become. Examples of these substrates may include collagen sheets, hyaluronic acid sheets, knits, weaves, braids, nonwovens, meltblowns, electrospun sheets, and other biotextiles. The substrate may start out strong, stiff, and robust or may start out as weak,- 8 - SG Docket No.: 14450-715.601flexible and / or delicate. The channels created by the stitching process may impact on the strength and compliance of the substrate in varying degrees. Meanwhile, the filaments added to the resultant composite structure change the mechanical characteristics, typically by adding strength and reducing compliance.

[0043] The embroidery patterns described herein have a multiple axis arrangement that imparts stabilizing qualities and mechanical characteristics otherwise not achievable with alternative embroidery arrangements. The stabilizing qualities and mechanical characteristics can be in the shear direction or out-of-plane. These characteristics can be mostly unidirectional, directionally biased, multi -directional, or isotropic. The multiple axis embroidery provides unique structural qualities while minimizing impact to substrate material.

[0044] The embroidery patterns can impact the properties of the substrate alone, or the substrate / embroidery composite. For example, given the same amount and type of filament embroidered into the same substrate, different patterns may yield different properties (substrate alone or with embroidery). The multiple axis pattem / sequence can yield desirable properties for substrate or substrate / embroidery composite.

[0045] The embroidered substrates may be, or be part of, a surgical graft. The grafts may be implants for soft tissue repair and / or regeneration applications, such as hernia repair, or breast reconstruction. In some cases, the implant provides a base scaffold that supports the repaired area until the patient’s body self-repairs, for example, as the patient’s cells infiltrate the surgical material and generate new tissue. In other cases, the patient’s body will not completely self-repair, or the repair will not be sufficiently strong such that the implant stands in for, or permanently reinforces, natural tissue. In the former case, it is often desired that the implant remain in place until the repaired tissue can shoulder the load forces, though this may be a slow and developing process that takes place over time. Examples of a surgical graft having performance enhancing embroidery patterns are described in U.S. Patent No. 10,213,284 and U.S. Patent No. 10,426,587, each of which is incorporated herein by reference in its entirety.

[0046] The embroidery patterns described herein include stitches, where an upper thread interlocks with a lower thread with a substrate therebetween. FIGS. 1 A-1B show example aspects of a stitch pattern. FIG. 1 A shows an example portion of a stitch pattern sewn in an embroidery run direction 107. The stitch pattern includes an upper thread 101 (e.g., on one side of a substrate) and a lower thread 103 (e.g., on the opposite side of the substrate). The upper thread 101 interlocks with the lower thread 103 at a stitch location 105.- 9 - SG Docket No.: 14450-715.601

[0047] FIG. IB shows a closeup view of a stitch location 105. When forming the stitch pattern in a substrate, a needle penetrates the substrate to interlock the upper thread 101 and the lower thread 103 at each interlock location 105.

[0048] FIG. 1C shows a plan (top) view of an example stitch pattern sewn into winding pattern, such as in a substrate. The stitch follows a continuous run direction 132 along a plane of the substrate to create a number of parallel rows 130 (e.g., lines) separated by switchback segments 131 (e.g. lines). In some examples, the rows 130 are sewn in parallel across an inner portion (e.g., a majority) of the substrate and the switchback segments 131 are sewn along the edges of the substrate. The upper and lower threads of the stitch pattern interlock at stitch locations 117, which is also where holes or channels are formed within the substrate.

[0049] FIGS. 2A-2F show an example of two overlaid stitch patterns to affect the compliance of the substrate. These figures show an intersection region of a second stitch pattern 227 that overlaps and intersects a first stitch pattern 225. The first stitch pattern 225 is embroidered into the substrate first so that the second stitch pattern 227 is sewn around the first stitch pattern 225 at their intersections. That is, the upper and lower threads of the second stitch pattern 227 envelop the upper and lower threads of the first stitch pattern 225.

[0050] FIGS. 2 A and 2B show perspective and top-down views, respectively, of the intersection region in a state where the second stitch pattern 227 intersects a midway point between two stitch locations 232a and 232b of the first stitch pattern 225. In this state, the second stitch pattern 227 is allowed some movement in either direction along the run direction 235 of the second stitch pattern 227. This midpoint position may be an initial position of the second stitch pattern 227, for example, when there are no pulling / stretching forces placed on the substrate.

[0051] FIGS. 2C and 2D show the intersection region after a stretching force is applied to the substrate, thereby causing the second lockstitch pattern 227 to shift toward and be stopped by the lockstitch 232b of the first lockstitch pattern 225. Note that in general, the stitching patterns described herein may refer to lock stitch stitching patterns. Likewise, FIGS. 2E and 2F show the intersection region after a different stretching force is applied to the substrate, thereby causing the second lockstitch pattern 227 to shift toward and be stopped by the lockstitch 232a of the first lockstitch pattern 225. In this way, movement of the second lockstitch pattern 227 along its run direction 235 is more limited or “locked” compared to the first lockstitch pattern 225 along its run direction 230. This results in more compliance of the substrate / graft when pulled or stretched along the run direction 230 compared to the run direction 235.- 10 - SG Docket No.: 14450-715.601

[0052] FIGS. 3A and 3B show an example of forming an embroidery pattern having a square grid construction in a substrate 300. FIG. 3A shows a first lockstitch pattern 325 sewn into the substrate 300 to form rows of lines 330 arranged in parallel and separated by switchback lines 331 that are non-parallel to the rows of lines 330. In this case, the rows of lines 330 are patterned into a majority of the area of the substrate 300, and the switchback lines 331 are embroidered along the edges of the substrate 300. The upper and lower threads of the first lockstitch pattern 325 interlock at lockstitch locations 317. The lockstitch locations 317 coincide with holes or channels formed within the substrate 300 to make the lockstitches.

[0053] FIG. 3B shows a second lockstitch pattern 327 sewn into the substrate 300 over the first lockstitch pattern 325. The second lockstitch pattern 327 forms rows of lines 332 arranged in parallel and separated by switchback lines 333 that are non-parallel to the rows of lines 332. The upper and lower threads of the second lockstitch pattern 327 envelope the upper and lower threads of the first lockstitch pattern 325 where they intersect. In this case, the first lockstitch pattern 325 and the second lockstitch pattern 327 intersect at lockstitch locations 317.

[0054] FIGS. 4A-4C show an example of forming an embroidery pattern having a triaxial construction in a substrate 400. FIG. 4A shows a first lockstitch pattern 425 sewn into the substrate 400 to form rows of lines 430 arranged in parallel and separated by switchback lines 431 that are non-parallel to the rows of lines 430. The upper and lower threads of the first lockstitch pattern 425 interlock at lockstitch locations 417. The lockstitch locations 417 coincide with holes or channels formed within the substrate 400 to make the lockstitches.

[0055] FIG. 4B shows a second lockstitch pattern 427 sewn into the substrate 400 over the first lockstitch pattern 425. The second lockstitch pattern 427 forms rows of lines 432 arranged in parallel and separated by switchback lines 433 that are non-parallel to the rows of lines 432. In this case, the rows of lines 432 of second lockstitch pattern 427 are sewn in a non-perpendicular and non-parallel orientation with respect to the rows of lines 430 of the first lockstitch pattern 425. The upper and lower threads of the second lockstitch pattern 427 envelop the upper and lower threads of the first lockstitch pattern 425 where they intersect at lockstitch locations 417. The first lockstitch pattern 425 and the second lockstitch pattern 427 share corresponding holes (also referred to as channels) within the substrate 400 at lockstitch locations 417.

[0056] FIG. 4C shows a third lockstitch pattern 429 sewn into the substrate 400 over the first lockstitch pattern 425 and the second lockstitch pattern 427. The third lockstitch pattern 429 forms rows of lines 434 arranged in parallel and separated by switchback lines 435 that - 11 - SG Docket No.: 14450-715.601are non-parallel to the rows of lines 434. In this case, the rows of lines 434 of third lockstitch pattern 429 are sewn in a non-perpendicular and non-parallel orientation with respect to the rows of lines 430 (of the first lockstitch pattern 425) and the rows of lines 432 (of the second lockstitch pattern 427). The upper and lower threads of the third lockstitch pattern 429 envelop the upper and lower threads of both the first lockstitch pattern 425 and second lockstitch pattern 427 where they intersect at lockstitch locations 417. The first lockstitch pattern 425, the second lockstitch pattern 427, and the third lockstitch pattern 429 share corresponding holes within the substrate 400 at lockstitch locations 417.

[0057] FIGS. 5A-5C show an example close-up view of one of the lockstitch locations 417 of FIGS. 4A-4C. FIG. 5A shows the lockstitch structure of the first lockstitch pattern 425, which includes an upper thread 501 that interlocks with a lower thread 503 in the lockstitch locations 417. The row (e.g., line) of the first lockstitch pattern 425 is arranged in parallel to a first run direction 507, which corresponds to a first axis.

[0058] FIG. 5B shows the second lockstitch pattern 427 overlaid onto the first lockstitch pattern 425. The row (e.g., line) of the second lockstitch pattern 427 is arranged in parallel to a second run direction 508, which corresponds to a second axis. The second run direction 508 (second axis) is non-parallel to the first run direction 507 (first axis). An upper thread 502 and a lower thread 504 of the second lockstitch pattern 427 envelop the upper thread 501 and lower thread 503 of the first lockstitch pattern 425 at each lockstitch location 417. In this arrangement, the first lockstitch pattern 425 locks movement of the second lockstitch pattern 427, thereby limiting movement and adding strength to the substrate (e.g., resistance to stretching) when a stretching force is applied along the second run direction 508 (second axis). In addition, a lockstitch of the second lockstitch pattern 427 coincides with a lockstitch of the first lockstitch pattern 425 in the same hole / channel of the substrate in which they intersect. This allows for less holes / channels in substrate compared to arrangements where lockstitches of intersection patterns do not share holes / channels.

[0059] FIG. 5C shows the third lockstitch pattern 429 overlaid onto both the first lockstitch pattern 425 and the second lockstitch pattern 427. The row (e.g., line) of the third lockstitch pattern 429 is arranged in parallel to a third run direction 509, which corresponds to a third axis. The third run direction 509 (third axis) is non-parallel to the first and second run directions 507 / 508 (first and second axes). An upper thread 505 and a lower thread 506 of the third lockstitch pattern 429 envelop the upper and lower threads of the first and second lockstitch patterns 425 / 427. In this arrangement, the first and second lockstitch patterns 425 / 427 lock movement of the third lockstitch pattern 429, thereby limiting movement and adding strength to the substrate (e.g., resistance to stretching) when a stretching force is - 12 - SG Docket No.: 14450-715.601applied along the third run direction 509 (third axis). In addition, a lockstitch of the third lockstitch pattern 429 coincides with lockstitches of the first and second lockstitch patterns 425 / 427 in the same hole / channel of the substrate in which they intersect. This shared construction among all three lockstitch patterns 425, 427, 429 reduces the number of holes created in the substrate (compared to patterns where they do not share holes) and allows the substrate to maintain more of its integrity.

[0060] In some cases, the threads within each shared hole of the substrate may entangle or intertwine with each other. In such cases, this may provide further resistance to movement of the lockstitch patterns 425, 427, 429, thereby further strengthening the substrate.

[0061] In the triaxial embroidery pattern of FIGS. 4A-5C, the rows of lines in each of the lockstitch patterns 425, 427, 429 are equally distanced from each other. In addition, the lines of each of the lockstitch patterns 425, 427, 429 are equally spaced radially at each intersection node (lockstitch locations 417). This arrangement of the first, second and third lockstitch patterns 425, 427, 429 forms an arrangement of equilateral triangles. This construction may provide added strength and allow the embroidery to be efficiently (e.g., equally) distributed among the three axes 507, 508, 509.

[0062] FIGS. 6A-8D compare construction and performance aspects of an example square grid embroidery pattern (e.g., FIGS. 3A-3B) to a triaxial embroidery pattern (e.g., FIG. 4A-5C) that are made of the same embroidery material (thread, filament) and the same amount of embroidery material by weight and thickness.

[0063] FIGS. 6 A and 6B show simplified plan views of the square grid and triaxial patterns, respectively. The square grid pattern shown in FIG. 6A forms squares having sides with lengths LI equal to 2.5 millimeters (mm). The triaxial pattern shown in FIG. 6B forms equilateral triangles with sides having a length L2 equal to 4.0 mm.

[0064] The triaxial pattern may provide more stabilization to a substrate compared to the square grid pattern due to its construction. For example, in the square grid pattern, half of the stitch lines (second lockstitch pattern) get locked by the other half of the stitch lines (first lockstitch pattern). In comparison, in the triaxial pattern, two-thirds of the stitch lines (second and third lockstitch patterns) get locked by one-third of the stitch lines (first lockstitch pattern).

[0065] FIGS. 7A and 7B show the holes formed in a substrate using the 2.5 mm square grid embroidery and the 4.0 mm triaxial embroidery, respectively. The square grid pattern has four filaments per channel. The triaxial pattern has six filaments per channel. For the same embroidered area, the triaxial pattern forms much fewer channels in the substrate compared- 13 - SG Docket No.: 14450-715.601to the square grid pattern - specifically, a 55% decrease in the number of channels in the substrate.

[0066] FIG. 8A compares the average maximum load performance of the square grid pattern embroidery and the triaxial grid pattern embroidery only. The embroidery patterns were formed in a removable substrate and the removable substrate was then removed, leaving only the embroidery material. To test the strength of the embroidery, a ball burst testing method was used, in which a ball is pushed against the embroidery while measuring resistance in Newtons (N). The maximum load corresponded to the maximum measured resistance before the embroidery broke / burst. The average of a number of samples were tested to determine the average maximum load. Results show that the 4.0 mm triaxial embroidery had an average maximum load of about 96 N, whereas the 2.5 mm square grid embroidery had an average maximum load of less than 80 N. Thus, for the same amount of embroidery area and material by weight, the 4.0 mm triaxial embroidery provided a greater resistance to breakage / bursting.

[0067] FIG. 8B compares the average maximum load performance of a two-layered biological substrate with channels (e.g., needle holes) formed therein in accordance with the square grid pattern (FIG. 7A) and the triaxial grid pattern (FIG. 7B). Results show that the substrate with channels according to the 4.0 mm triaxial embroidery had an average maximum load greater than 125 N, whereas the same substrate with channels according to 2.5 mm square grid embroidery had an average maximum load of less than 100 N. These results indicate that the fewer substrate channels created by the triaxial pattern compared to the number of substrate channels created by the square grid pattern yielded a stronger resistance to breakage / bursting.

[0068] FIG. 8C compares the average maximum load performance of a substrate with square grid pattern embroidery and the triaxial grid pattern embroidery. Results show that the substrate embroidered with the 4.0 mm triaxial pattern had an average maximum load of about 170 N, whereas the same substrate embroidered with the 2.5 mm square grid pattern had an average maximum load of about 155 N. These results indicate that the substrate embroidered with the triaxial pattern had a stronger resistance to breakage / bursting compared to the substrate embroidered with the square grid pattern.

[0069] FIG. 8D compares the load (N) per extension of a substrate embroidered with the square grid pattern and the triaxial pattern. These results indicate that, for a given load, a substrate with the triaxial pattern stretches less than the same substrate with the square grid pattern. This indicates that the triaxial pattern provides a substrate with more strength and resistance to deformation compared to the square grid pattern.- 14 - SG Docket No.: 14450-715.601

[0070] As discussed above, the triaxial embroidery patterns may form an arrangement of equilateral triangles of the same size. See, e.g., plan view of FIG. 6A. The length LI of the triangles may vary, for example, based on desired strength properties, size of graft, etc. In some examples, the length LI may range from about 2 millimeters (mm) and 8 mm.

[0071] The multiple axis embroidery patterns described herein may include any number of overlaying lockstitch patterns to create any number of corresponding rows arranged in parallel axes (e.g., 2, 3, 4, 5, 6, 7, 8 or more) and lockstitch patterns that share holes in a substrate.

[0072] For example, FIGS. 9A-9D show an example of forming an embroidery pattern having a quad-axial construction. FIG. 9A shows a first lockstitch pattern 925 to form rows of first lines 930 arranged in parallel. The first lockstitch pattern 925 may be sewn using a continuous run of thread with switchback lines, such as FIG. 4A, but such switchback lines are not shown for simplicity.

[0073] FIG. 9B shows a second lockstitch pattern 927 sewn over the first lockstitch pattern 925 to form a square grid pattern. The second lockstitch pattern 927 includes rows of second lines 932 arranged in parallel. The second lines 932 intersect the first lines 930 of the first lockstitch pattern 925 at first lockstitch locations 917. At each of the first lockstitch locations 917, the second lockstitch pattern 927 envelopes the upper and lower threads of the first lockstitch pattern 925. In addition, at each of the first lockstitch locations 917, the first and second lockstitch patterns 925, 927 penetrate the same hole.

[0074] FIG. 9C shows a third lockstitch pattern 929 sewn over the first and second lockstitch patterns 925, 927. The third lockstitch pattern 929 includes rows of third lines 934 arranged in parallel. The third lines 934 intersect the first and second lines 930, 932 of the first and second lockstitch patterns 925, 927 at the first lockstitch locations 917. At each of the first lockstitch locations 917, the third lockstitch pattern 929 envelopes the upper and lower threads of each of the first and second lockstitch patterns 925, 927. In addition, at each of the first lockstitch locations 917, the first, second and third lockstitch patterns 925, 927, 929 penetrate the same hole.

[0075] FIG. 9D shows a fourth lockstitch pattern 931 sewn over the first, second and third lockstitch patterns 925, 927, 929. The fourth lockstitch pattern 931 includes rows of fourth lines 936 arranged in parallel. The fourth lines 936 intersect the first, second, and third lines 930, 932, 934 of the first, second and third lockstitch patterns 925, 927, 929 at the first lockstitch locations 917. At each of the first lockstitch locations 917, the fourth lockstitch pattern 931 envelopes the upper and lower threads of each of the first, second and third- 15 - SG Docket No.: 14450-715.601lockstitch patterns 925, 927, 929. In addition, at each of the first lockstitch locations 917, the first, second, third and fourth lockstitch patterns 925, 927, 929, 931 penetrate the same hole.

[0076] In addition, the fourth lockstitch pattern 931 intersects with just the third lockstitch pattern 927 at second lockstitch location 919. At each of the second lockstitch locations 919, the fourth lockstitch pattern 931 envelopes the upper and lower threads of only the third lockstitch pattern 929. In addition, at each of the second lockstitch locations 919, only the third and fourth lockstitch patterns 929, 931 penetrate the same hole. Thus, at every intersection of the lockstitch patterns, there are two or four lockstitch patterns that share the same holes.

[0077] As shown, the quad-axial pattern of FIG. 9D forms an arrangement of equilateral triangles. This symmetrical arrangement may be conducive to providing symmetrical and improved strength to a substrate compared to unsymmetrical arrangements. In some examples, a length of each side of the triangles ranges from about 2 mm and 8 mm.

[0078] The substrates described herein may include biocompatible materials such as biotextiles. The biotextiles may be obtained or derived from living tissue. In some cases, the biotextiles include an extracellular matrix. Living tissue may include, for example dermis / skin tissue (and sub-tissue, extracellular matrices), pericardium, peritoneum, intestine, stomach, forestomach, and other suitable tissues. The animal source may be any suitable animal, including a mammal such as human, pig, cow, or sheep, or may be synthesized, for example, by recombinant expression. Biotextiles may be biodegradable or resorbable. Some non-limiting examples of biotextiles include extracellular matrix-derived tissue scaffolds or patches, autograft tissue, allograft tissue, and xenograft tissue, as well as artificial skin, artificial heart valves, and other implantable prosthetics.

[0079] The substrates described herein may include medical textiles made of one or more synthetic materials. Some non-limiting examples of synthetic materials may include polypropylene, polyethylene, as well as combinations of polypropylene and polyethylene, and / or other implantable polymers. Substrates comprising polypropylene may be preferred in some cases. Substrates comprising polyethylene, including polyethylene monofilaments may be preferred in some cases.

[0080] The substrates described herein may include a collagen sheet, a hyaluronic acid sheet, a knit, a weave, a braid, a nonwoven material, a meltblown material, an electrospun sheet, a biotextile material and / or a latex material.

[0081] The substrates described herein may comprise a film. The film may comprise one or more layers (e.g., placed on the outer surfaces) of the substrate, or the film may constitute- 16 - SG Docket No.: 14450-715.601the entire substrate. Support stitch patterns and / or compliance control stitch patterns may be sewn or embroidered into one or more layers of the film.

[0082] The substrates described herein may include one layer of material or multiple layers (e.g., 2, 3, 4, 5, 6 or more layers) of substrate material. The layers may be made of the same material or different materials. If multiple layers are used, the embroidery (e.g., multiple axis pattern) may be sewn through all or a subset of the layers.

[0083] The substrates described herein have any of a number of ranges of thickness. In some examples, the substrate has a thickness ranging from about 0.1 mm to about 1 mm (e.g., 0.1 mm to 0.25 mm, 0.1 mm to 0.5 mm, or 0.1 mm to 1.0 mm).

[0084] The thread (also referred to as filament) described herein may be made of one or more biocompatible materials. The thread may include one fiber (e.g., monofilament) or multiple fibers. The thread may be made of one material or multiple materials. The thread may be made of one or more synthetic materials and / or one or more materials obtained or derived from living tissue. In some examples, the thread includes one or more polymer materials, such as polypropylene and / or polyethylene.

[0085] In some examples, the thread and / or the substrate may include one or more biodegradable and / or resorbable materials. The biodegradable and / or resorbable material(s) may degrade and / or be resorbed by the body in a desired period of time, for example, after a sufficient amount of healing. In some examples, the thread and / or the substrate may include different biodegradable and / or resorbable materials that are configured to degrade and / or be resorbed at different rates. In some examples, the thread and / or the substrate includes a combination of biodegradable and / or resorbable materials and material(s) that are not configured to degrade and / or be resorbed.

[0086] The grafts described herein may include any number of support stitch patterns and compliance control stitch patterns. For example, a substrate may include one, two, three, four, five, six, or more support stitch patterns and / or one, two, three, four, five, six, or more compliance control stitching patterns. In some examples, the support stitch patterns are part of the compliance control stitch pattern.

[0087] Also described herein are apparatuses (e.g., grafts) and methods of forming them using a substrate having a plurality of pre-formed holes or pores that are relatively large (e.g., between 1-15 mm in diameter, e.g., between about 1-12 mm, between about 2-12 mm, between about 2-10 mm, between about 1-8 mm, etc.). As described above, different stitches (e.g., lock stitches) may share the same hole through the substrate, however in these examples the holes may be quite large. Thus, any of these methods and compositions (e.g., grafts) may be formed without piercing the substrate, by passing through pre-existing holes.- 17 - SG Docket No.: 14450-715.601

[0088] For example, FIGS. 10A-10C illustrate one method of forming an example of a graft having non-piercing embroidery. In this example the substrate includes a plurality of pre-formed openings, e.g., holes or macro-pores (having any shape) that are created in the substrate 1001 prior to embroidering. These holes may be any shape or size, particularly and advantageously between about 1-15 mm (e.g., about 2-12 mm, about 2-10 mm, etc.) in diameter. In the example shown in FIGS. 10 A- 10C the holes are 5 mm diameter. By embroidering through the pre-existing holes 1005, such as relatively large radius holes, in this example a circle, the process may result in significantly lower stress concentration areas. In FIG. 10A the needle may pass through he pores (“openings”) without piercing the substrate 1001 and stitch / embroider in a first pattern (e.g., ‘run direction’) 1003. In FIG. 10B the same substrate and holes (e.g., macropores) may be used to add a second (or more, see, e.g., FIG.10C) stitching pattern on top of the first stitching pattern, as shown. The second stitching pattern 1021 is formed on top of the fist, and the same rule may apply; stitches (e.g. comer lock stitches 1024) may only be formed through pre-existing holes 1005 in the substrate 1001. FIG. 10C shows yet another stitching pattern 1031 added to the first two stitching patterns 1011, 1021. The stitching pattern is arranged around the periphery of the insider of each opening. The central part of each opening may be left un-occluded, as shown in FIG. 11

[0089] Thus, in some examples the needle penetration (which may create a lock-stitch) may not pierce and break the substrate. Instead, the needle penetrates the substrate without damage through one or more pre-existing holes arranged over the substate. When forming the embroidery (e.g., stitching) pattern, the needle may pass into the pre-formed holes and may form a lock-stitch within the border region of the hole. If an embroidery needle pierces and breaks the substrate, a higher stress-concentrator may be formed. Thus, these methods may avoid passing through (e.g., piercing the substrate). This can help maintain the integrity and strength of the substrate, creating a final construct of substrate and embroidery, without the higher stress-concentrators of a needle breaking the substrate.

[0090] As described above, multiple needle penetrations can exist in the same hole. For the example shown, six needle penetrations, which would have otherwise had to created multiple (e.g., up to six) substrate high-stress-concentration features, instead are sharing 1 lower-stress-concentrating hole. In general, these methods and apparatuses may embroider a stich pattern using the pre-formed holes as described herein.

[0091] Embroidery patterns may be created such that needle-penetrations are formed within the border of the hole, and which may maintain a significant amount of unobstructed hole area. Any number of suture lines may have a penetration within the hole and specifically within the border of a hole. In FIG. 11, which shows a side perspective view, the suture - 18 - SG Docket No.: 14450-715.601pattern includes straight lines of thread / filament that traverse along the outside of a circular hole, within the hole border. FIG. 11 shows six (6) suture lines and six (6) lock-stitches formed within the border of each single hole of the substrate. As mentioned, the substrate may be preprocessed to form the pre-existing holes. Pre-existing holes may be formed in any appropriate manner, particularly in ways that do not otherwise weaken or damage the substate, e.g., but heating (burning), light (laser), and cutting (punching). FIG. 12 shows an example of one hole having a relatively large diameter in which the stitching pattern includes three sutures that each form a lock stitch within and at a periphery of the pre-formed hole. In FIG. 12 the majority of the area of the hole is left open, providing an unobstructed zone. In another example (not shown), an embroidery pattern could form an angle or “V”, changing direction within the border of the hole, using the substrate border / edge for support during change of direction, e.g., during embroidery. In another example (not shown), the embroidery pattern could form corner-lock features within the border of the hole. In another example, (not shown), the embroidery pattern could use, for example, only 3 suture lines forming a tri-axial pattern. The “node” of the triaxial pattern could exist at the inside edge of the border, or directly in the middle of the hole.

[0092] Thus, the method and apparatuses described herein form non-piercing embroidery grafts that include holes or macro-pores having any shape that are created in the substrate. These large radius holes, in the example shown in FIGS. 10A-10C, 11 and 12, the holes are each a circle, however other shapes may be used. Suturing through these holes may avoid the creation of high stress concentration areas as the needle pierces through substrate. Thus, in FIGS. 10 A- 10C, 11 and 12, needle penetration (which may create the lock-stitch) does not pierce and break the substrate. The needle may penetrate the substrate without damage.

[0093] Similarly, the needle may pass through the substrate and form a lock-stitch within the border region of the hole. Typically, if an embroidery needle pierces and breaks the substrate, a higher stress-concentrator is formed. The methods and compositions described herein can help maintain the integrity and strength of the substrate, creating a final construct of substrate and embroidery, without the higher stress-concentrators of a needle breaking the substrate.

[0094] In general, multiple needle penetrations can exist in the same hole, as illustrated in each of FIGS. 10A-10C, 11 and 12. For the example six (6) needle penetrations, which would have created six (6) substrate high-stress-concentration features, instead are sharing 1 lower-stress-concentrating pre-existing hole.- 19 - SG Docket No.: 14450-715.601

[0095] Embroidery patterns may be created such that needle-penetrations are formed within the border of the hole, and while maintaining a significant amount of unobstructed hole area. Any number of suture lines could have a penetration within the border of a hole.

[0096] In the example shown in FIGS. 11 and 12, straight lines traverse along the outside of a circular hole, within the hole border, and six suture lines and six lock-stitches are formed within the border of a single hole. In FIGS. 11 and 12, following the stitching, the resulting unobstructed zone 1115 is positioned in the middle of the hole and has a diameter that is at least 80% of the diameter of the hole.

[0097] As mentioned, in some examples (not shown), the embroidery pattern could form an angle or “V”, changing direction within the border of the hole, using the substrate border / edge for support during change of direction (during embroidery). The embroidery pattern could form corner-lock features within the border of the hole. The embroidery pattern could use, for example, only three suture lines forming a tri-axial pattern. The “node” of the triaxial pattern could exist at the inside edge of the border, or directly in the middle of the hole.

[0098] When a feature or element is herein referred to as being “on” another feature or element, it can be directly on the other feature or element, or intervening features and / or elements may also be present. In contrast, when a feature or element is referred to as being “directly on” another feature or element, there are no intervening features or elements present. It will also be understood that, when a feature or element is referred to as being “connected”, “attached” or “coupled” to another feature or element, it can be directly connected, attached or coupled to the other feature or element or intervening features or elements may be present. In contrast, when a feature or element is referred to as being “directly connected”, “directly attached” or “directly coupled” to another feature or element, there are no intervening features or elements present. Although described or shown with respect to one embodiment, the features and elements described or shown can apply to other embodiments. It will also be appreciated by those of skill in the art that references to a structure or feature that is disposed “adjacent” another feature may have portions that overlap or underlie the adjacent feature.

[0099] Terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. For example, as used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and / or “comprising,” when used in this specification, specify the presence of stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition - 20 - SG Docket No.: 14450-715.601of one or more other features, steps, operations, elements, components, and / or groups thereof. As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items and may be abbreviated as “ / ”.

[0100] Spatially relative terms, such as “under”, “below”, “lower”, “over”, “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is inverted, elements described as “under” or “beneath” other elements or features would then be oriented “over” the other elements or features. Thus, the exemplary term “under” can encompass both an orientation of over and under. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. Similarly, the terms “upwardly”, “downwardly”, “vertical”, “horizontal” and the like are used herein for the purpose of explanation only unless specifically indicated otherwise.

[0101] Although the terms “first” and “second” may be used herein to describe various features / elements (including steps), these features / elements should not be limited by these terms, unless the context indicates otherwise. These terms may be used to distinguish one feature / element from another feature / element. Thus, a first feature / element discussed below could be termed a second feature / element, and similarly, a second feature / element discussed below could be termed a first feature / element without departing from the teachings of the present invention.

[0102] Throughout this specification and the claims which follow, unless the context requires otherwise, the word “comprise”, and variations such as “comprises” and “comprising” means various components can be co-jointly employed in the methods and articles (e.g., compositions and apparatuses including device and methods). For example, the term “comprising” will be understood to imply the inclusion of any stated elements or steps but not the exclusion of any other elements or steps.

[0103] In general, any of the apparatuses and methods described herein should be understood to be inclusive, but all or a sub-set of the components and / or steps may alternatively be exclusive and may be expressed as “consisting of’ or alternatively “consisting essentially of’ the various components, steps, sub-components or sub-steps.

[0104] As used herein in the specification and claims, including as used in the examples and unless otherwise expressly specified, all numbers may be read as if prefaced by the word “about” or “approximately,” even if the term does not expressly appear. The phrase “about”- 21 - SG Docket No.: 14450-715.601or “approximately” may be used when describing magnitude and / or position to indicate that the value and / or position described is within a reasonable expected range of values and / or positions. For example, a numeric value may have a value that is + / - 0.1% of the stated value (or range of values), + / - 1% of the stated value (or range of values), + / - 2% of the stated value (or range of values), + / - 5% of the stated value (or range of values), + / - 10% of the stated value (or range of values), etc. Any numerical values given herein should also be understood to include about or approximately that value, unless the context indicates otherwise. For example, if the value “10” is disclosed, then “about 10” is also disclosed. Any numerical range recited herein is intended to include all sub-ranges subsumed therein. It is also understood that when a value is disclosed that “less than or equal to” the value, “greater than or equal to the value” and possible ranges between values are also disclosed, as appropriately understood by the skilled artisan. For example, if the value “X” is disclosed the “less than or equal to X” as well as “greater than or equal to X” (e.g., where X is a numerical value) is also disclosed. It is also understood that throughout the application, data is provided in a number of different formats, and that this data, represents endpoints and starting points, and ranges for any combination of the data points. For example, if a particular data point “10” and a particular data point “15” are disclosed, it is understood that greater than, greater than or equal to, less than, less than or equal to, and equal to 10 and 15 are considered disclosed as well as between 10 and 15. It is also understood that each unit between two particular units are also disclosed. For example, if 10 and 15 are disclosed, then 11, 12, 13, and 14 are also disclosed.

[0105] Although various illustrative embodiments are described above, any of a number of changes may be made to various embodiments without departing from the scope of the invention as described by the claims. For example, the order in which various described method steps are performed may often be changed in alternative embodiments, and in other alternative embodiments one or more method steps may be skipped altogether. Optional features of various device and system embodiments may be included in some embodiments and not in others. Therefore, the foregoing description is provided primarily for exemplary purposes and should not be interpreted to limit the scope of the invention as it is set forth in the claims.

[0106] The examples and illustrations included herein show, by way of illustration and not of limitation, specific embodiments in which the subject matter may be practiced. As mentioned, other embodiments may be utilized and derived there from, such that structural and logical substitutions and changes may be made without departing from the scope of this disclosure. Such embodiments of the inventive subject matter may be referred to herein - 22 - SG Docket No.: 14450-715.601individually or collectively by the term “invention” merely for convenience and without intending to voluntarily limit the scope of this application to any single invention or inventive concept, if more than one is, in fact, disclosed. Thus, although specific embodiments have been illustrated and described herein, any arrangement calculated to achieve the same purpose may be substituted for the specific embodiments shown. This disclosure is intended to cover any and all adaptations or variations of various embodiments. Combinations of the above embodiments, and other embodiments not specifically described herein, will be apparent to those of skill in the art upon reviewing the above description.- 23 - SG Docket No.: 14450-715.601

Claims

CLAIMSWhat is claimed is:

1. A surgical graft, comprising:a substrate comprising a repeating pattern of pre-existing holes through the substrate, the holes having a diameter of between 2 and 12 millimeters (mm);an embroidery pattern sewn into the substrate through the pre-existing holes so as not to form local stress concentrators in the substrate, the embroidery pattern comprising first, second, and third stitching patterns,wherein the first stitch pattern overlays the second stitch pattern, and the third stitch pattern overlays the first and second stitch patterns;wherein the first stitch pattern includes a plurality of first rows arranged in parallel, the second stitch pattern includes a plurality of second rows arranged in parallel, and the third stitch pattern includes a plurality of third rows arranged in parallel, wherein the first, second, and third rows are not parallel to each other; andwherein the first, second and third stitch patterns pass through the substrate through the pre-existing holes at an edge region of the pre-existing holes, leaving an unobstructed zone through a center of the pre-existing holes.

2. The surgical graft of claim 1, wherein the first, second and third stitch patterns pass through the substrate only through the pre-existing holes at the edge region of the preexisting holes.

3. The surgical graft of claim 1, wherein greater than 90% of the first, second and third stitch patterns pass through the substrate only through the pre-existing holes at the edge region of the pre-existing holes.

4. The surgical graft of claim 1, wherein each of the first, second and third stitch patterns forms a lock stitch pattern within the pre-existing holes.

5. The surgical graft of claim 1, wherein each of the first, second and third stitch patterns forms a plurality of equilateral triangles.

6. The surgical graft of claim 5, wherein a length of each side of the plurality of equilateral triangles ranges from about 2 millimeters (mm) and 8 mm.-24 - SG Docket No.: 14450-715.6017. The surgical graft of claim 1, wherein the plurality of pre-existing holes are arranged in a pattern of offset rows in the substrate.

8. The surgical graft of claim 1, wherein the plurality of pre-existing holes are circular.

9. The surgical graft of claim 1, wherein the surgical graft has a maximum load resistance of 160 N or greater.

10. The surgical graft of claim 1, wherein the embroidery pattern includes a fourth stitch pattern sewn into the substrate through the pre-existing holes so as not to form local stress concentrators in the substrate, the fourth stitch pattern including a plurality of fourth rows arranged in parallel to a fourth axis that is nonparallel to the first, second, and third rows.

11. The surgical graft of claim 1, wherein at least a portion of each of the first, second, and third stitch patterns are passing through the pre-existing holes are arranged around the periphery of the pre-existing holes.

12. The surgical graft of claim 1, wherein upper and lower threads of each of the first, second, and third stitch patterns interlock within the shared plurality of holes.

13. The surgical graft of claim 1, wherein the substrate includes multiple layers.

14. The surgical graft of claim 1, wherein the substrate includes one or more layers of: a collagen sheet, a hyaluronic acid sheet, a knit, a weave, a braid, a nonwoven material, a meltblown material, an electrospun sheet, a biotextile material, and / or a latex material.

15. A surgical graft, comprising:a substrate comprising a repeating pattern of pre-existing holes through the substrate, the holes having a diameter of between 2 and 12 millimeters (mm);an embroidery pattern sewn into the substrate through the pre-existing holes so as not to pierce the substrate and form local stress concentrators in the substrate, the embroidery pattern comprising a stitching pattern formed of lock stiches within the pre-existing holes, andwherein the embroidery pattern passes through the substrate through the pre-existing holes at an edge region within the pre-existing holes, leaving an unobstructed zone through a center of the pre-existing holes.- 25 - SG Docket No.: 14450-715.60116. The surgical graft of claim 15, wherein the embroidery pattern passes through the substrate only through the pre-existing holes at an edge region of the pre-existing holes.

17. The surgical graft of claim 15, wherein greater than 90% of the embroidery pattern passes through the substrate only through the pre-existing holes at the edge region of the preexisting holes.

18. The surgical graft of claim 15, wherein the plurality of pre-existing holes are arranged in a pattern of offset rows in the substrate.

19. The surgical graft of claim 15, wherein the plurality of pre-existing holes are circular.

20. The surgical graft of claim 15, wherein the surgical graft has a maximum load resistance of 160 N or greater.

21. The surgical graft of claim 15, wherein the substrate includes multiple layers.

22. The surgical graft of claim 15, wherein the substrate includes one or more layers of: a collagen sheet, a hyaluronic acid sheet, a knit, a weave, a braid, a nonwoven material, a meltblown material, an electrospun sheet, a biotextile material, and / or a latex material.

23. A method of forming a surgical graft, the method comprising:sewing a stitch pattern into a substrate, the substrate comprising a repeating pattern of pre-existing holes through the substrate, the holes having a diameter of between 2 and 12 mm,wherein stitch pattern is sewn into the substrate through the pre-existing holes without piercing the substrate so as not to form local stress concentrators in the substrate, the stitch pattern comprising lock stiches within the pre-existing holes, andwherein the stich pattern passes through the substrate through the pre-existing holes at an edge region within the pre-existing holes, leaving an unobstructed zone through a center of the pre-existing holes.

24. The method of claim 23, wherein the stitch pattern comprises a first, a second, and a third stitching pattern, wherein the first stitch pattern overlays the second stitch pattern, and the third stitch pattern overlays the first and second stitch patterns, and wherein the first stitch pattern includes a plurality of first rows arranged in parallel, the second stitch pattern includes a plurality of second rows arranged in parallel, and the third stitch pattern - 26 - SG Docket No.: 14450-715.601includes a plurality of third rows arranged in parallel, wherein the first, second, and third rows are not parallel to each other.

25. The method of claim 23, wherein the stitched surgical graft has a maximum load resistance of 160 N or greater.

26. The method of claim 25, wherein at least a portion of the threads of the first, second, and third stitch patterns are entangled with each other within the shared plurality of holes.

27. The method of claim 25, wherein an upper and a lower thread of each of the first, second, and third stitch patterns interlock within the shared plurality of holes.

28. The method of claim 23, wherein the substrate includes multiple layers.- 27 - SG Docket No.: 14450-715.601

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