Tissue reinforcement device

Abstract

[Problem] To suppress unintended deformation of staples when biological organs are anastomosed by the staples in a state in which a tissue reinforcement device is sandwiched between the biological organs. [Solution] The present invention comprises a plurality of openings 50 that are larger or longer than a through-hole 11 of a body section 10 and are defined by a circumferential edge. Of the plurality of openings, at least two adjacent openings disposed on concentric circles centered on the center of an insertion part 30 are disposed within 60 degrees in the circumferential direction without any portion of the circumferential edges of the openings missing, and the interval between center of gravity positions of the adjacent openings is 45 degrees or less in the circumferential direction.

Description

Tissue reinforcement device

[0001] The present invention relates to a tissue reinforcement device.

[0002] In the medical field, a technique for surgically joining living organs (for example, gastrointestinal anastomosis) is known. When such a technique is performed, it is known that it is important as a postoperative prognostic factor that the healing at the joint where the living organs are joined does not cause a delay.

[0003] In the technique of anastomosing living organs, various methods and medical instruments are used. For example, a method of suturing living organs with biodegradable sutures and a method of using a mechanical anastomosis device that performs anastomosis with a stapler have been proposed. In particular, when performing anastomosis using a mechanical anastomosis device, since the joining force between living organs at the joint can be increased compared to the method using sutures, the risk of suture failure can be reduced.

[0004] Japanese Patent Publication No. 2008-516678

[0005] In the anastomosis device of Patent Document 1, in order to prevent leakage or fracture at the anastomosis site, the healing of the anastomosis site is promoted by sandwiching a sheet-like member such as a support structure (hereinafter referred to as a tissue reinforcement device). The inventors of the present invention have discovered that when anastomosing living organs with the tissue reinforcement device sandwiched between the living organs, depending on the form of the tissue reinforcement device, it may cause deformation of the staples. Since this staple deformation may affect the anastomosis state at the anastomosis site, intensive studies have been conducted on suppressing unintended staple deformation.

[0006] Therefore, the present invention is to suppress unintended staple deformation when anastomosing living organs with staples with the tissue reinforcement device sandwiched between the living organs.

[0007] The present invention is achieved by any one of the following means (1) to (14).

[0008] (1) A tissue reinforcement device used by being sandwiched between the anastomoses of a living organ, comprising: a sheet-like main body having a plurality of through holes and containing a fibrous material made of a biodegradable material; a plurality of openings that are larger or longer than the through holes of the main body and defined by their peripheral edges; and an insertion portion through which a medical instrument can be inserted at the center of the main body in the planar direction, wherein at least two adjacent openings centered on the center of the insertion portion are arranged within 60 degrees in the circumferential direction without any gaps in the peripheral edges of the openings, and the distance between the centroid positions of adjacent openings is 45 degrees or less in the circumferential direction.

[0009] (2) The tissue reinforcement device according to (1) above, wherein at least two of the openings are arranged within a 30-degree angle in the circumferential direction with respect to the central part of the main body in the planar direction, without any missing peripheral edges of the openings.

[0010] (3) The tissue reinforcement device according to (1) or (2) above, wherein the shortest distance between the peripheral edges of adjacent openings in the main body is 0.8 mm or more.

[0011] (4) The tissue reinforcement device according to any one of (1) to (3) above, wherein the opening has the maximum width in the circumferential direction of concentric circles centered on the insertion portion, is arranged over a predetermined width extending from the center of the insertion portion, and the predetermined width is greater than the maximum width.

[0012] (5) The tissue reinforcement device according to any one of (1) to (4) above, wherein when the tissue reinforcement device is loaded into a circular stapler having a circular cutter portion and a circular staple portion, the opening is positioned in an area that overlaps with at least the cutter portion.

[0013] (6) The tissue reinforcement device according to (5) above, wherein the opening is located in an area that does not overlap with the staple portion.

[0014] (7) The tissue reinforcement device according to any one of (1) to (6) above, wherein the opening is a slit.

[0015] (8) The tissue reinforcement device according to any one of (1) to (6) above, wherein the opening is a cutout.

[0016] (9) The tissue reinforcement device according to any one of (1) to (8) above, wherein the main body portion has a fusion portion around the through hole where the fibers gather and fuse together.

[0017] (10) The tissue reinforcement device according to (9) above, wherein the through hole is formed along the thickness direction of the main body and the fused portion is formed along the thickness direction.

[0018] (11) The tissue reinforcement device according to (9) or (10), wherein the fused portion comprises a portion in which the fibers are completely fused and a portion in which the area around the fibers is fused while maintaining the shape of the fibers.

[0019] (12) The tissue reinforcement device according to any one of (9) to (11) above, wherein the main body portion comprises a proximity portion located near the through hole in the planar direction of the main body portion, and a distal portion located further away from the through hole in the planar direction than the proximity portion, and the fibers are present at a higher density in the proximity portion than in the distal portion.

[0020] (13) The fused portion is formed in the vicinity of the tissue reinforcement device described in (12) above.

[0021] (14) The tissue reinforcement device according to (5) above, wherein the opening can suppress deformation of the staples by distributing the tension applied to the tissue reinforcement device when using the circular stapler.

[0022] According to the tissue reinforcement devices described in (1) to (14) above, when anastomosing a biological organ with a staple while the tissue reinforcement device is sandwiched between the biological organs, unintended deformation of the staple can be suppressed.

[0023] This is a schematic diagram showing a tissue reinforcement device according to an embodiment. This is an enlarged cross-sectional view showing a through hole in the main body of the tissue reinforcement device. This is an exploded perspective view showing a part (tip) of a medical instrument used when anastomosing biological organs using the tissue reinforcement device. This is an enlarged image showing the fusion portion of the tissue reinforcement device. This is an enlarged image showing the fusion portion of the tissue reinforcement device. This is an enlarged image showing the fusion portion of the tissue reinforcement device. This is a schematic diagram showing the pitch of the tissue reinforcement device according to an embodiment. This is a schematic diagram showing the pitch of the tissue reinforcement device according to an embodiment. This is a schematic diagram showing a tissue reinforcement device according to a modified example of Figure 1. This is a schematic diagram showing a tissue reinforcement device according to a modified example of Figure 1. This is a schematic diagram showing a tissue reinforcement device according to a modified example of Figure 1. This is a schematic diagram showing a tissue reinforcement device according to a modified example of Figure 1. This is a schematic perspective view showing a state in which the tissue reinforcement device is placed between the first engaging device and the second engaging device constituting the medical instrument. This is a schematic diagram showing staples when a tissue reinforcement device without an opening is punched out with a medical instrument. This is a schematic diagram showing staples when a tissue reinforcement device with an opening is punched out with a medical instrument. This is a schematic diagram showing a state in which the cutter portion of the medical instrument and staples are placed on the biological tissue to be anastomosed. This is a schematic diagram showing the placement of the cutter and staples at the anastomosis site with a tissue reinforcement device positioned between the biological tissues to be anastomosed. This is a photograph showing the tissue reinforcement device used in the experiment. This is a photograph showing the tissue reinforcement device used in the experiment. This is a photograph of the staples viewed from the axial direction when the intestines were anastomosed with a tissue reinforcement device without an opening sandwiched between the intestines. This is a photograph of the staples viewed from the axial direction when the intestines were anastomosed with the tissue reinforcement device shown in Figure 18 sandwiched between the intestines. This is a photograph of the staples viewed from the axial direction when the intestines were anastomosed with the tissue reinforcement device shown in Figure 19 sandwiched between the intestines.

[0024] Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. The embodiments shown herein are illustrative examples to embody the technical idea of ​​the present invention and do not limit the present invention. Furthermore, all other implementable forms, examples, and operational techniques that can be conceived by those skilled in the art without departing from the spirit of the present invention are included in the scope and spirit of the present invention, as well as in the claims and their equivalents.

[0025] Furthermore, the drawings attached to this specification may be schematically represented with changes to scale, aspect ratio, shape, etc., from the actual object for the sake of illustration and ease of understanding, but these are merely examples and do not limit the interpretation of the present invention.

[0026] Furthermore, in the following explanations, ordinal numbers such as "first" and "second" are used, but unless otherwise specified, they are used for convenience and do not prescribe any particular order.

[0027] <Tissue Reinforcement Device> Figure 1 is a schematic diagram showing a tissue reinforcement device 100 according to an embodiment. Figure 2 is an enlarged view showing the through-holes 11 of the tissue reinforcement device. The tissue reinforcement device 100 is positioned sandwiched between two or more biological organs to be anastomosed (one site to be joined and the other site to be joined), and is configured in a flat sheet shape with a plurality of through-holes 11. Here, "positioned sandwiched between two or more biological organs to be anastomosed" means at least one of the following: the tissue reinforcement device 100 is positioned in a state where it is directly or indirectly in contact with the biological organs, the tissue reinforcement device 100 is positioned in a state where a spatial gap is formed between it and the biological organs, or the tissue reinforcement device 100 is positioned in both states (for example, the tissue reinforcement device 100 is in contact with one biological organ and not in contact with the other biological organ). Examples of biological organs include tubular organs such as the large intestine, jejunum, and pancreatic duct. As shown in Figure 1 and other figures, the tissue reinforcement device 100 comprises a main body portion 10, a fixing portion 20, an insertion portion 30, a fusion portion 40, and an opening 50. Alternatively, the tissue reinforcement device 100 may consist only of the main body portion 10, the insertion portion 30, the fusion portion 40, and the opening 50, without the fixing portion 20. Note that some drawings illustrate a Cartesian coordinate system; hereafter, the plane direction of the main body portion 10 will be referred to as the plane direction YZ, and the thickness direction will be referred to as the thickness direction X. Further details are provided below.

[0028] <Main body> The main body 10 is positioned between two biological organs to be anastomosed (for example, two large intestines, or a pancreatic duct and a jejunum), and is configured as a sheet that can follow the movement of the biological organs to be anastomosed.

[0029] As shown in Figure 1, the main body 10 is formed in a circular shape as an example, and as shown in Figure 2, it has a plurality of through holes 11 formed to be inserted in the thickness direction X (axial direction) of the circular shape. As an example of the size (hole diameter D) of the through holes 11 of the main body 10, it is preferably 0.1 to 6 mm, more preferably 0.3 to 4 mm, and even more preferably 0.6 to 1.5 mm. The main body 10 can promote a fusion effect through the through holes 11. The ratio of the dimension of the through hole 11 (the distance shown in Figure 2, which is the hole diameter D of the through hole 11) to the pitch P (the distance shown in Figure 2, which is the distance between the opening edges of two through holes 11) can be configured to be 0.25 or more and less than 40. Since the main body 10 has a plurality of through holes 11, there are a plurality of values ​​for the hole diameter D corresponding to each through hole 11. Therefore, in this embodiment, when calculating the value of the ratio described above, the arithmetic mean of two or more values ​​of the hole diameter D corresponding to each of the plurality of through holes 11 is used as the representative value of the hole diameter D. On the other hand, the pitch P of the multiple through holes 11 is defined by the shortest distance between the openings of two through holes 11. However, there are multiple values ​​for pitch P corresponding to combinations of adjacent through holes 11. Therefore, in this embodiment, when calculating the ratio value described above, the arithmetic mean of two or more pitch P values ​​corresponding to each combination of adjacent through holes 11 is used as the representative value of pitch P. However, the pitch P described above is an example and may be periodic or random. Note that the (true) circle described as the shape of the main body 10 is an example and may also be configured to include other shapes such as ellipses, polygons such as quadrilaterals, and star shapes.

[0030] The thickness of the main body portion 10 (dimension T shown in Figure 2) is not particularly limited, but is preferably 0.05 to 0.7 mm, and more preferably 0.25 to 0.45 mm. The numerical values ​​for thickness and size mentioned above are examples, and other sizes are also acceptable. When the dimension T, which is the thickness of the main body portion 10, is 0.7 mm or less (especially when it is 0.45 mm or less), the flexibility of the main body portion 10 can be increased. As a result, the main body portion 10 adheres closely to the biological organ, and its ability to follow the movement of the biological organ is improved. On the other hand, if the dimension T, which is the thickness of the main body portion 10, is 0.05 mm or less, the strength of the main body portion 10 is insufficient, and the tissue reinforcement device 100 will twist, making it difficult to position it between the biological organs to be anastomosed.

[0031] The main body 10 can be made from a sheet-like molded product formed by knitting or weaving a multifilament of multiple fibers (e.g., yarn) made of biodegradable material. In other words, the main body 10 can be made from a biodegradable sheet. There are no particular restrictions on the constituent materials of the main body 10; for example, biodegradable resin can be used.

[0032] Examples of biodegradable resins include (1) polymers selected from the group consisting of aliphatic polyesters, polyesters, polyacid anhydrides, polyorthoesters, polycarbonates, polyphosphazenes, polyphosphate esters, polyvinyl alcohols, polypeptides, polysaccharides, proteins, and cellulose; and (2) copolymers composed of one or more monomers that make up (1) above.

[0033] In other words, the biodegradable sheet preferably contains at least one biodegradable resin selected from the group consisting of polymers selected from the group consisting of aliphatic polyester, polyester, polyacid anhydride, polyorthoester, polycarbonate, polyphosphazene, polyphosphate ester, polyvinyl alcohol, polypeptide, polysaccharide, protein, and cellulose, and copolymers composed of one or more monomers constituting the polymer. The main body 10 is preferably made of a bioabsorbable material such as polyglycolic acid (PGA) or PLGA (polylactic acid / glycolic acid copolymer).

[0034] The main body 10 is made by processing a sheet of biodegradable fibers into a nonwoven fabric, and then undergoing a heating process to form through-holes 11. The main body 10 thus created induces a biological reaction through its constituent materials, such as biodegradable resin. Through this action, the main body 10 induces the expression of biological components such as fibrin. The biological components thus induced can promote fusion by accumulating through the through-holes 11 of the main body 10 from both sides in the surface direction YZ. Therefore, by placing the main body 10 of the tissue reinforcement device 100 sandwiched between biological organs to be joined (for example, between anastomosing intestinal segments of the large intestine, between the cut surfaces of anastomosing intestinal segments of the large intestine, or between the pancreatic parenchyma and the jejunum), fusion is promoted by the above mechanism.

[0035] Figure 3 is an exploded perspective view showing the tip of a medical instrument 200 used when placing a tissue reinforcement device 100 into a living organ. The medical instrument 200 comprises a first engagement device 210 and a second engagement device 250. The medical instrument 200 may also be called a circular stapler, the first engagement device 210 may also be called a trocar, and the second engagement device 250 may also be called an anvil. A portion of the outer side of the main body 10 is integrated with the first and second joined parts by deformation when staples L released from the discharge portion 240 (corresponding to the staple portion) of the first engagement device 210 of the medical instrument 200 are clamped together with the contact portion 270 of the second engagement device 250 which is opposite the discharge portion 240. A punching portion 230 (corresponding to the cutter portion) is provided circumferentially on the radially inward side of the discharge portion 240, which can punch out living tissue and the tissue reinforcement device 100 in a circumferential manner. The positioning portion 220, located in the center of the first engaging device 210, is housed inside a hollow shaft 260 that protrudes from a contact portion 270 that contacts the release portion 240 of the second engaging device 250, thereby aligning the first engaging device 210 and the second engaging device 250.

[0036] <Fixing part> The fixing part 20 is provided to prevent or suppress displacement of the tissue reinforcement device 100 and to prevent it from falling off when the tissue reinforcement device 100 is placed between the first and second areas to be joined. As shown in Figure 1, the fixing part 20 is formed along the inner periphery of the hollow circular shape of the main body 10. That is, the fixing part 20 is formed to surround the central point Pt (virtual point) of the tissue reinforcement device 100 in the plane direction YZ. The tissue reinforcement device 100 is arranged in the order of fixing part 20 and main body 10 from the central point Pt outward in the plane direction YZ.

[0037] The fixing portion 20 is configured in a shape that does not have a through hole 11 in the main body portion 10. The fixing portion 20 can be made of a bioabsorbable material such as a thermoplastic resin such as PGA (polyglycolic acid), PLA (polylactic acid), PLGA (polylactic acid / glycolic acid copolymer), PDS (polydioxanone), or PCL (polycaprolactone).

[0038] The fixing portion 20 may be provided around the entire circumference on the inward side of the main body portion 10 in the surface direction YZ, or it may be provided partially in one or more locations around the entire circumference. Although the fixing portion 20 is configured coaxially with the inner edge, its center position may be offset from the main body portion 10 as long as it does not enter the fusion region. The fixing portion 20 and the inward side of the main body portion 10 are punched out by the punching portion 230 of the first engaging device 210 of the medical instrument 200 during the procedure, separating them from the outward side of the main body portion 10. Note that the fixing portion 20 is not required. If the fixing portion 20 is not provided, the inner periphery of the tissue reinforcement device 100 is composed of the main body portion 10 with a through hole 11 that extends inward from the main body portion 10.

[0039] <Insertion portion> As shown in Figure 1, the insertion portion 30 is spaced apart from the outer peripheral edge of the main body portion 10 in the surface direction YZ of the main body portion 10 and is provided approximately in the center in the surface direction, and in this embodiment it is formed by the fixing portion 20. The insertion portion 30 is configured to be insertable onto the shaft 260 of the second engaging device 250 of the medical device 200. In this embodiment, the insertion portion 30 has a hole diameter larger than the hole diameter D of each through hole 11, so it is configured to be insertable onto the shaft 260. The shaft 260 of the second engaging device 250 is configured to accommodate the positioning portion 220 of the first engaging device 210.

[0040] In this embodiment, the insertion portion 30 is configured to be approximately circular when viewed from the thickness direction X. However, the specific shape of the hole is not limited to a circular shape as long as the main body portion 10 can promote the fusion of biological tissue. The cross-section of the insertion portion 30 is preferably a perfect circle, but it may also be configured to be linear, elliptical, triangular, square, concave, convex, cross-shaped, or other types of notches.

[0041] <Fused portion> Figures 4 to 6 are images showing a part of the fused portion 40. The fused portion 40 is configured as a part where fibers gather and fuse together around the through hole 11. The through hole 11 of the main body portion 10 is formed along the thickness direction X of the main body portion 10. The fused portion 40 is configured to be formed along the thickness direction X.

[0042] The fused portion 40 shown in Figure 5 comprises a first portion 41 in which the fibers are completely fused, as shown in Figure 4, and a second portion 42 in which the area around the fibers is fused while maintaining the shape of the fibers. Here, "completely fused" means that the fibers are a single, unified entity (so integrated that even when examined under a microscope, the originally separate fibers cannot be distinguished). "The area around the fibers is fused while maintaining the shape of the fibers" means that the fibers are not a single, unified entity (so integrated that even when examined under a microscope, the originally separate fibers cannot be distinguished), but there is a portion in which the area around the fibers is melted and the fibers are fused together (so integrated that even when examined under a microscope, the originally separate fibers can be distinguished).

[0043] As shown in FIG. 6, the main body portion 10 includes a vicinity portion 12 located in the vicinity of the through-hole 11 in relation to the fusion portion 40, and a distal portion 13 spaced apart from the through-hole 11 in the YZ plane direction further than the vicinity portion 12. The vicinity portion 12 includes the opening edge of the through-hole 11. The distal portion 13 includes the periphery around the center of the distance (pitch P) between two through-holes 11. Here, in the main body portion 10, the range from the edge of one through-hole 11 to less than 50% of the length between adjacent through-holes 11 can be the vicinity portion 12, and the other range can be the distal portion 13. The vicinity portion 12 is configured such that fibers exist at a higher density than the distal portion 13.

[0044] As will be described later, the fusion portion 40 is formed on the vicinity portion 12 and the distal portion 13 on one side (the first surface) in the thickness direction X, and is configured to be formed only on the vicinity portion 12 on the other side (the second surface opposite to the first surface). The fusion portion 40 can be formed such that at least a part of multiple multi-filaments in which a plurality of fibers are bundled are fused. However, the fusion portion 40 may be formed such that at least a part of the fibers (threads) of the multi-filaments are fused. The size of the fusion portion 40 is not particularly limited, but for example, it can be configured to be from 0.015 mm to 0.7 mm. The fusion portion 40 can be configured such that the ratio to the non-melted portion is 3% or more and 100% or less. Also, the occupancy rate of the fusion portion 40 with respect to the main body portion 10 when the main body portion 10 is viewed in plan (seen from the thickness direction X) can be configured to be 0.002% or more.

[0045] <Opening Portion> FIGS. 7 and 8 are schematic views showing the pitch of the opening portion 50 in the tissue reinforcement device 100 according to the embodiment. The opening portion 50 is defined by a peripheral edge portion, is configured to be larger or longer than the through-hole 11, and a plurality of them are provided in the circumferential direction with the center of the insertion portion 30 as the center. The opening portion 50 is formed at regular intervals in the circumferential direction of the main body portion 10. As shown in FIG. 7, the opening portion 50 is arranged such that the peripheral edge portions of two adjacent opening portions 50 do not lack at an angle within 60 degrees in the circumferential direction, and as shown in FIG. 8, the distance between the centers of gravity of the opening portions 50 is configured to be within 45 degrees. In FIG. 1, the opening portion 50 is configured in an elliptical shape, and the position of the center of gravity is the intersection of the long axis and the short axis of the ellipse.

[0046] It is more preferable that the openings 50 are arranged so that two or more openings 50 are placed within a 30-degree angle in the circumferential direction with respect to the center of the main body 10 in the planar direction, without any gaps in the peripheral edges of the openings 50. As shown in Figure 1, the openings 50 have a maximum width d1 in the circumferential direction of concentric circles centered on the insertion portion 30, and are arranged over a predetermined width d2 extending from the center of the insertion portion 30, where the predetermined width d2 can be made larger than the maximum width d1. The openings 50 are placed in an area that overlaps with at least the cutter portion (punching portion 230) when the tissue reinforcement device 100 is loaded into the medical instrument 200. Also, the openings 50 are placed in an area that does not overlap with the area where the staples L are placed.

[0047] Figures 9 to 12 are schematic diagrams showing modified openings in a tissue reinforcement device. The shape of the openings is not particularly limited as long as they are arranged within the pitch range described above. In addition, while making the openings larger increases the effect of suppressing deformation of the staples, it may also reduce operability as the entire main body becomes more prone to twisting, so it is preferable to keep the maximum width of the openings to less than 6.5 mm. Also, by bringing the openings 50 closer together, the strength of the main body 10 is reduced, thus increasing the effect of suppressing deformation of the staples when using the medical instrument 200. However, if the openings 50 are brought too close together, the strength of the device body is reduced, which may cause the openings to connect before use, increasing the risk of device damage. Therefore, it is desirable that the closest distance between the peripheral edges of the openings be 0.8 mm or more, more preferably 0.85 mm or more, and even more preferably 1.0 mm or more. In addition, in order to suppress the connection of the openings by through holes, it is preferable that the closest distance between the peripheral edges of the openings be greater than the diameter of the through holes. In this context, "closest" refers to the opening that is closest in a straight line to a given opening among the different openings arranged around it, and is not limited to openings arranged concentrically with respect to the center of the main body 10 in the planar direction. The opening 50a may be formed as a rectangle larger than the through hole 11, as shown in Figure 9. The opening 50b may be formed by arranging multiple small circles larger than the through hole 11 across multiple diameters at the above-described pitch, as shown in Figure 10. The opening 50c may be formed by arranging multiple slits longer than the through hole 11 inclined with respect to the radial direction in the circumferential and radial directions, as shown in Figure 11. The opening 50d may be formed by arranging multiple cross-shaped slits larger than the through hole 11 in the circumferential direction, and arranging multiple types of these in the radial direction, as shown in Figure 12.

[0048] Incidentally, the position of the center of gravity is the intersection of the diagonal lines in the case of FIG. 9, the center of the circle in the case of FIG. 10, the midpoint on the line segment in the case of FIG. 11, and the center of the cross shape in the case of FIG. 12. Further, the openings 50a, 50b, and 50d in FIGS. 9, 10, and 12 can also be said to be cutouts formed by removing the shape of the main body portion 10. In this specification, the difference between a slit and a cutout is that a slit is a shape formed by cutting fibers without cutting the material from the state where the through-hole 11 is formed. On the other hand, a cutout is a shape formed by removing the material from the state where the through-hole 11 is formed, or a shape in which an opening having a larger area than the through-hole 11 is formed in the plane direction. By making the opening a slit, the fiber material constituting the main body portion 10 is partially cut, so that the force applied to the main body portion 10 during the anastomosis operation is more easily dispersed, and the deformation of the staple L can be suppressed. Further, by creating the opening by cutting, the area of the main body portion 10 that abuts on the punched portion 230 of the medical device 200 is reduced, so that the force applied to the punching operation of the main body portion 10 is reduced, and the deformation of the staple L can be suppressed.

[0049] As described above, the tissue reinforcement device 100 is used by being sandwiched between the anastomosis parts of a living body organ, and includes a main body portion 10, an opening portion 50, and an insertion portion 30. The main body portion 10 includes a fiber material made of a biodegradable material, has a plurality of through-holes 11, and is configured in a sheet shape. The opening portion 50 is larger or longer than the through-hole 11 of the main body portion 10, and is defined by a peripheral edge portion and provided in plurality. The insertion portion 30 is provided at the central portion in the plane direction of the main body portion 10 and is configured to be able to insert the medical device 200. Among the plurality of opening portions 50, at least two adjacent opening portions 50 centered on the center of the insertion portion 30 are arranged within 60 degrees in the circumferential direction without the peripheral edge portion of the opening portion 50 being missing, and the distance between the centers of gravity of the adjacent opening portions 50 is configured to be 45 degrees or less in the circumferential direction.

[0050] Figures 13 to 17 are schematic diagrams illustrating a tissue reinforcement device 100 with openings. In Figure 13, the openings 50 are not shown for convenience. When the tissue reinforcement device 100 is placed between the first engaging device 210 and the second engaging device 250 and a cutting operation is performed, the staples L are inserted through the tissue reinforcement device 100 as shown in Figure 17, and both ends are folded so as not to bulge in the axial direction (thickness direction X). Here, as shown in Figure 16, before the punching section 230 cuts the biological organ, a relatively large force is applied to the staples L while they are inside the biological organ, which may cause unintended deformation of the staples L, that is, deformation such that the staples L bulge in a direction perpendicular to the axial direction. In contrast, as shown in Figures 1 and 15, by providing openings 50 in the tissue reinforcement device 100 at the above pitch, the force acting on the staples L is distributed, making it easier to cut the main body 10 and suppressing unintended deformation of the staples L compared to the case where there are no openings 50 as shown in Figure 14.

[0051] Furthermore, at least two openings 50 are arranged within a 30-degree angle in the circumferential direction of the main body 10, with respect to the center of the main body 10 in the YZ plane direction, without any missing peripheral edges of the openings 50. This configuration makes it easier to cut the main body 10 and suppresses unintended deformation of the staples L.

[0052] Furthermore, the opening 50 has a maximum circumferential width d1 in a concentric circle centered on the insertion portion 30, and is arranged over a predetermined width d2 extending from the center of the insertion portion 30. The predetermined width d2 can be made larger than the maximum width d1. By configuring it in this way, the main body portion 10 can be easily cut, and unintended deformation of the staple L can be suppressed.

[0053] Furthermore, when the tissue reinforcement device 100 is loaded into the medical instrument 200, which is equipped with a circular punching section 230 and a circular discharge section 240, the opening 50 is positioned in an area that overlaps with at least the punching section 230. This configuration makes it easier to cut the main body 10 and suppresses unintended deformation of the staple L.

[0054] Furthermore, the opening 50 is positioned in an area that does not overlap with the discharge section 240. This configuration prevents the part that is implanted in the body from being punched through, thus preventing a decrease in the strength of the main body 10, and also allows the main body 10 to make sufficient contact with the anastomosis site, thereby exhibiting a healing effect.

[0055] Furthermore, the opening 50 can be a slit or a cutout. This configuration makes it easier to cut the main body 10 and suppresses unintended deformation of the staple L.

[0056] Furthermore, the main body portion 10 has a fusion portion 40 where fibers gather and fuse together around the through hole 11. This configuration makes it easier to maintain the shape of the through hole 11 in the main body portion 10. Also, by configuring the fusion portion 40 as described above, the rigidity of the main body portion 10 can be increased, preventing or suppressing the occurrence of twisting or displacement of the tissue reinforcement device 100. In addition, by increasing the rigidity of the main body portion 10, fraying when the tissue reinforcement device 100 is punched out with a stapler such as a medical instrument 200 can be prevented or suppressed, and it can be punched out more easily.

[0057] Furthermore, the through-hole 11 is formed along the thickness direction X of the main body portion 10. The fusion portion 40 is configured to be formed along the thickness direction X. Therefore, it is possible to increase the rigidity of the main body portion 10 and contribute to preventing or suppressing twisting in the tissue reinforcement device 100.

[0058] Furthermore, the fused portion 40 comprises a first portion 41 in which the fibers are completely fused, and a second portion 42 in which the fibers retain their shape while the area around them is fused. The presence of the first portion 41 in addition to the second portion 42 in the fused portion 40 makes it easier for biological components to penetrate the gaps between the fibers, thereby facilitating the bonding effect.

[0059] Furthermore, the main body portion 10 comprises a proximity portion 12 located near the through hole 11 in the YZ plane direction of the main body portion 10, and a distal portion 13 located further away from the through hole 11 in the YZ plane direction than the proximity portion 12. The proximity portion 12 is configured such that the fibers are arranged to avoid each other, resulting in a higher density of fibers in the proximity portion 12 than in the distal portion 13. This configuration makes it easier to improve the strength of the main body portion 10, thereby making it easier to maintain the shape of the through hole 11.

[0060] Furthermore, the fused portion 40 is formed in the vicinity portion 12 in the thickness direction X. This configuration makes it easier to maintain the shape of the through hole 11 and prevents or suppresses fraying when the tissue reinforcement device 100 is punched out by the medical instrument 200.

[0061] Furthermore, the opening 50 can suppress deformation of the staples L by distributing the tension applied to the tissue reinforcement device 100 when using the medical instrument 200, which is a circular stapler.

[0062] (Experiment) Next, we will explain the deformation of the staple L when the tissue reinforcement device according to the example and the tissue reinforcement device according to the comparative example were inserted into a medical instrument and punched out. Figures 18 and 19 are photographs of the tissue reinforcement device used in this experiment, and Figures 20 to 22 are photographs of the staple L viewed from the axial direction when the intestinal tract was joined with the tissue reinforcement device sandwiched between the intestinal tract.

[0063] In this experiment, the state of the staples L, which were used to join the severed intestinal tracts extracted from pigs using a medical device 200, was confirmed using X-ray CT imaging. Using this state as a reference, the dimensions of the staples L in the direction perpendicular to the axial direction (the direction with the greatest degree of deformation) were measured when the following three tissue reinforcement devices 100 were placed between the unjointed intestinal tracts, and a significant difference in the degree of deformation compared to the reference was confirmed.

[0064] The first case involves a tissue reinforcement device with through-holes 11 and no openings 50, placed between the intestinal tract (see Figure 14, comparative example). The second case involves a rectangular opening 50 in the main body 10, as shown in Figure 18, with the centers of gravity of adjacent openings spaced approximately 45 degrees apart (example). The third case involves an opening 50 larger than the through-holes 11 in the main body 10, with the centers of gravity of adjacent openings spaced approximately 22.5 degrees apart (example). For these three cases, a t-test was used to check for statistical significance (whether the p-value was greater than 0.05).

[0065] In the three cases described above, punching and joining with staple L were performed using the medical instrument 200, and then only the staple L was removed and its condition was observed. First, in the first case (comparative example), the p-value was below 0.05, indicating that the staple L was significantly different from the standard, meaning that the staple L was significantly deformed in the axial direction (see Figure 20). On the other hand, in the second and third cases (examples), the p-value was above 0.05, indicating no significant difference from the standard, meaning that the deformation of the staple L could be suppressed to the same extent as the standard (see Figures 21 and 22).

[0066] The present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the claims.

[0067] This application is based on Japanese Patent Application No. 2024-169982, filed on 30 September 2024, the disclosures of which are cited in their entirety by reference.

[0068] 10 Main body, 11 Through hole, 12 Nearby part, 13 Distal part, 30 Insertion part, 40 Fusion part, 41 First part, 42 Second part, 50 Opening, 100 Tissue reinforcement device, 200 Medical instrument (circular stapler), 230 Punching part (cutter part), 240 Discharge part (staple part), d1 Maximum width, d2 Width, X Thickness direction, YZ Plane direction.

Claims

1. A tissue reinforcement device used by being sandwiched between the anastomoses of a living organ, comprising: a sheet-like main body having a plurality of through holes and containing a fibrous material made of a biodegradable material; a plurality of openings that are larger or longer than the through holes of the main body and defined by their peripheral edges; and an insertion portion through which a medical instrument can be inserted at the center of the main body in the planar direction, wherein at least two adjacent openings centered on the center of the insertion portion are arranged within 60 degrees in the circumferential direction without any gaps in the peripheral edges of the openings, and the distance between the centroid positions of adjacent openings is 45 degrees or less in the circumferential direction.

2. The tissue reinforcement device according to claim 1, wherein at least two or more openings are arranged within a 30-degree angle in the circumferential direction with respect to the central part of the main body in the planar direction, without any missing peripheral edges of the openings.

3. The tissue reinforcement device according to claim 1, wherein the shortest distance between the peripheral edges of adjacent openings in the main body is 0.8 mm or more.

4. The tissue reinforcement device according to claim 1, wherein the opening has the maximum circumferential width of concentric circles centered on the insertion portion and is arranged over a predetermined width extending from the center of the insertion portion, and the predetermined width is greater than the maximum width.

5. The tissue reinforcement device according to claim 1, wherein when the main body is loaded into a circular stapler having a circular cutter section and a circular staple section, the opening is positioned in an area that overlaps with at least the cutter section.

6. The tissue reinforcement device according to claim 5, wherein the opening is located in a region that does not overlap with the staple portion.

7. The tissue reinforcement device according to claim 1, wherein the opening is a slit.

8. The tissue reinforcement device according to claim 1, wherein the opening is a cutout.

9. The tissue reinforcement device according to claim 1, wherein the main body portion has a fusion portion around the through hole where the fibers gather and fuse together.

10. The tissue reinforcement device according to claim 9, wherein the through hole is formed along the thickness direction of the main body, and the fused portion is formed along the thickness direction.

11. The tissue reinforcement device according to claim 10, wherein the fused portion comprises a portion in which the fibers are completely fused and a portion in which the area around the fibers is fused while maintaining the shape of the fibers.

12. The tissue reinforcement device according to claim 10, wherein the main body comprises a proximity portion located near the through hole in the planar direction of the main body and a distal portion located further away from the through hole in the planar direction than the proximity portion, the proximity portion having a higher density of fibers than the distal portion.

13. The tissue reinforcement device according to claim 12, wherein the fused portion is formed in the vicinity of the fused portion.

14. The tissue reinforcement device according to claim 5, wherein the opening can suppress deformation of the staples by distributing the tension applied to the tissue reinforcement device when using the circular stapler.

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