Medical sheet and method for producing medical sheet

Abstract

[Problem] To enhance the rigidity of a body part constituting a medical sheet, and to prevent or suppress twisting when arranged in a biological organ. [Solution] The present invention includes a sheet-like body part 10 containing fibers composed of a biodegradable material. The body part has a fusion part 50 in which a plurality of through-holes 11 are formed and fibers are gathered and fused around the through-holes.

Description

Medical sheet and method for manufacturing medical sheet

[0001] The present invention relates to a medical sheet and a method for manufacturing a medical sheet.

[0002] In the medical field, surgical procedures for joining biological organs (e.g., anastomosis of the digestive tract) are known. When such procedures are performed, it is known that the absence of delayed healing at the junction where the biological organs are joined is an important factor in determining the postoperative prognosis.

[0003] Various methods and medical instruments are used in the anastomosis of biological organs, including a method using biodegradable sutures and a method using a mechanical anastomosis device that performs anastomosis with a stapler. In particular, when performing anastomosis using a mechanical anastomosis device, the joining strength between biological organs at the joint can be increased compared to methods using sutures, thereby reducing the risk of anastomosis failure.

[0004] Special Publication No. 2008-516678

[0005] The anastomosis device of Patent Document 1 promotes healing of the anastomosis site by sandwiching a sheet-like member (hereinafter referred to as a medical sheet) such as a support structure to prevent leakage or tearing at the anastomosis site. Such medical sheets are typically relatively thin and soft. The inventors have been actively studying ways to increase the rigidity of the main body of the medical sheet, prevent the medical sheet from twisting (a state where the medical sheet is bent or folded and not flat) when placed in a living organ, and prevent the medical sheet from fraying (a state where the fibers are loose at the cut ends of the fibers) when performing anastomosis using a mechanical anastomosis device.

[0006] Therefore, an object of the present invention is to increase the rigidity of the main body portion that constitutes a medical sheet, and to prevent or suppress twisting and fraying when the sheet is placed on a living organ.

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

[0008] (1) A medical sheet having a sheet-like main body containing fibers made of a biodegradable material, in which a plurality of through holes are formed and which has fused portions formed by gathering and fusing fibers around the through holes.

[0009] (2) A medical sheet according to (1) above, wherein the through holes are formed along the thickness direction of the main body portion, and the fused portions are formed along the thickness direction.

[0010] (3) A medical sheet according to (1) or (2) above, wherein the fused portion comprises a portion where the fibers are completely fused and a portion where the fibers are fused around the fibers while maintaining their shape.

[0011] (4) A medical sheet according to any one of (1) to (3) above, wherein the main body portion comprises a proximal portion located near the through-hole in the planar direction of the main body portion, and a distal portion that is farther away from the through-hole in the planar direction than the proximal portion, and the fibers are present at a higher density in the proximal portion than in the distal portion.

[0012] (5) The medical sheet according to (4) above, wherein the fused portion is formed in the vicinity of the fused portion.

[0013] (6) A medical sheet as described in (4) or (5) above, in which the main body portion has a first surface and a second surface formed on the opposite side of the first surface, and the fused portion is formed in the adjacent portion and the distal portion on the first surface, and is formed only in the adjacent portion on the second surface.

[0014] (7) A medical sheet according to any one of (1) to (6) above, wherein the main body portion is made of multifilaments of the fiber, and the fused portion is formed by at least some of the multifilaments being fused together.

[0015] (8) A method for manufacturing a medical sheet, comprising: penetrating a needle into a sheet member containing fibers made of a biodegradable material to form a through-hole; and heating the needle while the needle is still penetrating the sheet member; or penetrating the heated needle into the sheet member to form a fused portion in the fibers around the through-hole.

[0016] (9) A method for manufacturing a medical sheet as described in (8) above, wherein when the needle is heated after penetrating the sheet member to form the through hole, or when the heated needle is penetrated into the sheet member, the needle is heated to a temperature above the melting point of the fiber.

[0017] (10) A method for manufacturing a medical sheet as described in (8) above, wherein when the needle is heated after penetrating the sheet member to form the through hole, or when the heated needle is penetrated into the sheet member, the needle is heated to a temperature above the melting point of the fiber.

[0018] (11) A method for manufacturing a medical sheet according to any one of (8) to (10) above, in which the needles are heated after penetrating the sheet member to form the through holes, and the needles are heated by heating the base while the planar base on which the needles are placed is in contact with the sheet member, thereby forming the fused portion.

[0019] (12) A method for manufacturing a medical sheet according to any one of (8) to (10) above, in which the needle is heated after penetrating the sheet member to form the through hole, or the heated needle is penetrated into the sheet member, the needle is penetrated into the sheet member in a state where multiple sheet members are stacked, and the needle is heated by maintaining the needle at a predetermined temperature for a predetermined time.

[0020] (13) A method for manufacturing a medical sheet according to any one of (8) to (12) above, in which the fibers of the plurality of sheet members are needle-punched before the needles are pierced through the sheet members, and the fibers of the plurality of sheet members are entangled with each other before the needle-punching is performed.

[0021] (14) The method for manufacturing a medical sheet according to any one of (8) to (13) above, wherein the sheet member is cooled after applying heat to the needles, and the needles are removed from the sheet member.

[0022] According to the medical sheet described in (1) to (7) above and the method for manufacturing a medical sheet described in (8) to (14) above, the rigidity of the main body constituting the medical sheet can be increased, and twisting and fraying when placed in a biological organ can be prevented or suppressed.

[0023] 1 is a perspective view showing a medical sheet according to an embodiment. FIG. 1 is an enlarged cross-sectional view showing through holes in a main body portion of a medical sheet. FIG. 2 is a view showing the shape pattern of through holes in a medical sheet. FIG. 3 is a view showing a shape pattern of modified through holes in a medical sheet. FIG. 4 is a view showing a shape pattern of modified through holes in a medical sheet. FIG. 5 is a perspective view showing a medical sheet according to a modified example of FIG. 1. FIG. 6 is an exploded perspective view showing a portion (tip portion) of a medical instrument used when anastomotic biological organs using a medical sheet. FIG. 7 is an enlarged image showing fused portions of a medical sheet. FIG. 8 is an enlarged image showing fused portions of a medical sheet. FIG. 9 is a flowchart showing a method for manufacturing a medical sheet according to an embodiment. FIG. 10 is a view showing a needle member used in a method for manufacturing a medical sheet according to a first embodiment. FIG. 11 is a schematic view showing the formation of through holes in a sheet member with a needle member. FIG. 12 is a view showing a needle member used in a method for manufacturing a medical sheet according to a second embodiment.

[0024] <First Embodiment> Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. The embodiments shown here are provided as examples to embody the technical idea of ​​the present invention and are not intended to limit the present invention. Furthermore, all other embodiments, 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 scope of the inventions described in the claims and their equivalents.

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

[0026] In the following description, ordinal numbers such as "first" and "second" are used, but unless otherwise specified, these are used for convenience and do not stipulate any particular order.

[0027] <Medical Sheet> FIG. 1 is a perspective view showing a medical sheet 100 according to an embodiment. FIG. 2 is an enlarged view showing a through-hole 11 of the medical sheet. The medical sheet 100 is sandwiched between two or more biological organs (one to be joined and the other to be joined) to be anastomosed, and is configured as a flat sheet with multiple through-holes 11 formed therein. Here, "sandwiched between two or more biological organs to be anastomosed" means at least one of the following: the medical sheet 100 is placed in direct or indirect contact with the biological organs; the medical sheet 100 is placed with a spatial gap formed between the biological organs; or the medical sheet 100 is placed in both of these states (e.g., the medical sheet 100 is placed in contact with one biological organ and not in contact with the other biological organ). Examples of biological organs include hollow organs such as the large intestine, the jejunum, and the pancreatic duct. As shown in Figure 1 and other figures, the medical sheet 100 comprises a main body portion 10, a reinforcing portion 20, a fixing portion 30, holes 40, and a fused portion 50. The medical sheet 100 may not comprise the reinforcing portion 20 and the fixing portion 30, but may instead comprise the main body portion 10, holes 40, and a fused portion 50. Alternatively, the medical sheet 100 may not comprise the reinforcing portion 20, but may instead comprise the main body portion 10, fixing portion 30, holes 40, and a fused portion 50. Some of the drawings illustrate an orthogonal coordinate system, and below, the surface direction of the main body portion 10 is referred to as the surface direction YZ, and the thickness direction is referred to as the thickness direction X. This will be described in more detail below.

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

[0029] The main body 10 is formed, for example, in a circular shape as shown in FIG. 1 , and includes a plurality of through holes 11 formed to pass through the circular shape in the thickness direction X (axial direction) as shown in FIG. 2 . The size (hole diameter D) of the through holes 11 in the main body 10 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 healing by the through holes 11. The main body 10 can be configured such that the ratio of the dimension of the through holes 11 (the distance shown in FIG. 2 , the hole diameter D of the through holes 11) to the pitch P (the distance shown in FIG. 2 , the distance between the opening edges of two through holes 11) is 0.25 or greater and less than 40. Because the main body 10 has a plurality of through holes 11, there are multiple values ​​of the hole diameter D corresponding to each through hole 11. Therefore, in this embodiment, when calculating the above-mentioned ratio, the arithmetic mean value of two or more values ​​of the hole diameter D corresponding to each of the plurality of through holes 11 is used as a representative value of the hole diameter D. On the other hand, the pitch P of the multiple through holes 11 is defined as the shortest distance between the openings of two through holes 11. However, there are also multiple values ​​of the pitch P corresponding to combinations of adjacent through holes 11. Therefore, in this embodiment, when calculating the value of the above-mentioned ratio, the arithmetic mean value of two or more values ​​of the pitch P corresponding to each combination of adjacent through holes 11 is used as the representative value of the pitch P. However, the above-mentioned pitch P is an example and may be periodic or random. Note that the (perfect) circle described as the shape of the main body 10 is an example, and other shapes such as an ellipse, a polygon such as a rectangle, a star, etc. may also be used.

[0030] Fig. 3 is a diagram showing the shape pattern of the through holes 11 in the main body 10, and Figs. 4 to 6 are diagrams showing shape patterns according to modified examples of the through holes 11 in the main body 10. In Figs. 2 and 3, the through holes 11 are shown with the same shape and at equal pitches. However, the shape pattern of the through holes 11 is not limited to this. In addition to the above, it is also possible to arrange through holes 11 of different sizes at equal intervals as shown in Fig. 4, to arrange through holes of the same size at a 60° staggered pitch (staggered arrangement) as shown in Fig. 5, or to arrange through holes 11 of different sizes randomly as shown in Fig. 6.

[0031] The thickness of the main body portion 10 (dimension T shown in FIG. 2 ) is not particularly limited, but is preferably 0.05 to 0.7 mm, and more preferably 0.25 to 0.45 mm. The above-mentioned values ​​for the thickness, size, and other dimensions are merely examples, and other dimensions may also be used. When the dimension T, which is the thickness of the main body portion 10, is 0.7 mm or less (particularly when it is 0.45 mm or less), the flexibility of the main body portion 10 can be increased. This allows the main body portion 10 to adhere closely to the biological organ and improve its ability to follow the movement of the biological organ. On the other hand, when 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 medical sheet 100 may become twisted, making it difficult to place it between the biological organs to be anastomosed.

[0032] The main body 10 can be formed from a sheet-like molded product made by knitting or weaving a multifilament of multiple fibers (e.g., yarn) made of a biodegradable material as a starting material. That is, the main body 10 can be formed from a biodegradable sheet. There are no particular limitations on the material that can be used to make the main body 10, and examples of such materials include biodegradable resins.

[0033] Examples of biodegradable resins include (1) polymers selected from the group consisting of aliphatic polyesters, polyesters, polyanhydrides, polyorthoesters, polycarbonates, polyphosphazenes, polyphosphate esters, polyvinyl alcohols, polypeptides, polysaccharides, proteins, and cellulose; and (2) copolymers composed of one or more monomers constituting the above (1).

[0034] That is, the biodegradable sheet preferably contains at least one biodegradable resin selected from the group consisting of polymers selected from the group consisting of aliphatic polyesters, polyesters, polyanhydrides, polyorthoesters, polycarbonates, polyphosphazenes, polyphosphate esters, polyvinyl alcohols, polypeptides, polysaccharides, proteins, and cellulose, as well as copolymers composed of one or more monomers that constitute the polymers.The main body 10 is preferably made of a bioabsorbable material, such as polyglycolic acid (PGA) or PLGA (polylactic acid-glycolic acid copolymer).

[0035] The main body 10 is produced by converting a sheet of processed biodegradable fibers into a nonwoven fabric, followed by a process involving heating to form the through-holes 11. The main body 10 thus produced induces a biological reaction due to the constituent materials, such as biodegradable resin, that make up the main body 10. This action of the main body 10 induces the expression of biological components such as fibrin. The biological components induced in this manner can be accumulated by penetrating the through-holes 11 of the main body 10 from both sides in the planar direction YZ, thereby promoting healing. Therefore, by placing the main body 10 of the medical sheet 100 in a sandwiched state between biological organs to be joined (e.g., between two anastomosed intestinal tracts of the large intestine, between cut surfaces of anastomosed intestinal tracts of the large intestine, or between the pancreatic parenchyma and the jejunum), healing is promoted by the above-mentioned mechanism.

[0036] <Reinforcing section> The reinforcing section 20 is provided to prevent the medical sheet 100 from twisting, shifting, breaking, falling off, etc. when the medical sheet 100 is placed between the first bonded region (one bonded region) and the second bonded region (the other bonded region). The reinforcing section 20 is formed along the outer periphery of the hollow circular body section 10.

[0037] In this embodiment, the reinforcing portion 20 is configured to have higher rigidity than the main body portion 10. In this embodiment, the reinforcing portion 20 is configured in a shape that does not include through holes 11 in the main body portion 10. The reinforcing portion 20 is preferably 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). However, the reinforcing portion 20 may also include a non-bioabsorbable material.

[0038] The reinforcing member 20 may be provided along the entire outer periphery of the main body 10 in the planar direction YZ, or may be provided at one or more locations along the entire periphery. Here, the outward direction refers to the direction away from the center Pt (an imaginary point) of the medical sheet 100 in the planar direction YZ. The direction toward the center Pt of the medical sheet 100 in the planar direction YZ is the inward direction. The reinforcing member 20 may be bonded to the main body 10 with adhesive or thermal fusion, or sewn with thread. The reinforcing member 20 need not be provided. Figure 7 is a perspective view showing a medical sheet 100a according to a modified example that does not include the reinforcing member 20. As shown in Figure 7, the medical sheet 100 may be composed of the main body 10, the fixing member 30, the hole portion 40, and the fused portion 50. When the reinforcing member 20 is not provided, the outer periphery of the medical sheet 100 is composed of the main body 10 having through-holes 11 extending outward from the main body 10.

[0039] 8 is an exploded perspective view showing the distal end of a medical device 200 used when placing the medical sheet 100 on a biological organ. The medical device 200 includes a first engaging device 210 and a second engaging device 250. The medical device 200 may also be called a stapler, the first engaging device 210 may also be called a trocar, and the second engaging device 250 may also be called an anvil. The reinforcing portion 20 and a portion of the main body portion 10 on the outward side (the main body portion 10 near the inner periphery of the reinforcing portion 20) are integrated into the first and second bonded portions by being deformed when a staple is clamped by the clamping portion 270 of the second engaging device 250 facing the release portion 240 of the first engaging device 210 of the medical device 200.

[0040] <Fixing section 30> The fixing section 30 is provided to prevent or inhibit shifting of the medical sheet 100 and to prevent it from falling off, for example, when the medical sheet 100 is placed between the first and second bonded sections. The fixing section 30 is formed along the inner peripheral edge of the hollow circular shape of the main body section 10. That is, the fixing section 30 is formed to surround the center Pt (an imaginary point) of the medical sheet 100 in the planar direction YZ. Therefore, the medical sheet 100 is composed of a circular reinforcing section 20 formed to surround the center Pt of the medical sheet 100, the main body section 10 formed to surround the outer periphery of the reinforcing section 20, and the reinforcing section 20 formed to surround the outer periphery of the main body section 10. The medical sheet 100 is arranged in the following order from the center Pt outward in the planar direction YZ: the fixing section 30, the main body section 10, and the reinforcing section 20.

[0041] The fixing portion 30 is configured in a shape in which no through-hole 11 is provided in the main body portion 10, similar to the reinforcing portion 20. The fixing portion 30 can be configured from the same material as the reinforcing portion 20.

[0042] The fixing portion 30 may be provided along the entire circumference on the inward side of the main body portion 10 in the planar direction YZ, or may be provided at one or more locations along the entire circumference. The fixing portion 30 is configured coaxially with the inner edge, but its center may be offset from the main body portion 10 as long as it does not enter the fusion region. The fixing portion 30 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 device 200 during the procedure, and are separated from the outward side of the main body portion 10 and the reinforcing portion 20. The fixing portion 30 does not necessarily have to be provided. When the fixing portion 30 is not provided, the inner peripheral edge of the medical sheet 100 is formed by the main body portion 10 having through holes 11 that extend continuously inward from the main body portion 10.

[0043] <Hole> The hole 40 is spaced from the outer periphery of the main body 10 in the planar direction YZ of the main body 10, and is formed by the fixing portion 30 in this embodiment. The hole 40 is configured to be able to insert the shaft 260 of the second engaging device 250 of the medical device 200. In this embodiment, the hole 40 has a hole diameter larger than the hole diameter D of each through-hole 11, and is therefore configured to be able to insert the shaft 260. The shaft 260 of the second engaging device 250 is configured to be able to accommodate the positioning portion 220 of the first engaging device 210.

[0044] In this embodiment, the hole 40 is configured to have a substantially circular shape 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 10 can promote healing of biological tissue. The cross section of the hole 40 is preferably a perfect circle, but may also be configured to have a linear, elliptical, triangular, rectangular, concave, convex, cross-shaped or other notch shape.

[0045] 9 to 11 are images showing a part of the fused portion 50. The fused portion 50 is configured as a region where fibers gather and fuse around the through-hole 11. The through-hole 11 of the main body 10 is formed along the thickness direction X of the main body 10. The fused portion 50 is configured to be formed along the thickness direction X.

[0046] The fused portion 50 shown in FIG. 10 includes a first portion 51 in which the fibers are completely fused, as shown in FIG. 9 , and a second portion 52 in which the peripheries of the fibers are fused while maintaining the fiber shape. Here, "completely fused" refers to a state in which the fibers are fused together (i.e., fibers that are originally separate are integrated to an extent that they cannot be distinguished even when viewed under a microscope). "Fused around the peripheries of the fibers while maintaining the fiber shape" refers to a state in which the fibers are not fused together (i.e., fibers that are originally separate are integrated to an extent that they cannot be distinguished even when viewed under a microscope), but the peripheries of the fibers are fused together (i.e., fibers that are originally separate are integrated to an extent that they can be distinguished even when viewed under a microscope). As shown in FIG. 11 , the main body 10 includes a proximal portion 12 located near the through hole 11 relative to the fused portion 50, and a distal portion 13 that is farther from the through hole 11 in the planar direction YZ than the proximal portion 12. The proximal portion 12 includes the edge of the through hole 11. The distal portion 13 includes the periphery of the center of the distance (pitch P) between two through holes 11. Here, the range from the edge of one through hole 11 in the main body portion 10 to less than 50% of the length between adjacent through holes 11 can be the proximal portion 12, and the remaining range can be the distal portion 13. The proximal portion 12 is configured so that fibers exist at a higher density than the distal portion 13.

[0047] As described below, the fused portion 50 is formed in the proximal portion 12 and the distal portion 13 on one side (first surface) in the thickness direction X, and is formed only in the proximal portion 12 on the other side (second surface opposite the first surface). The fused portion 50 can be formed so that at least a portion of the multifilament fibers (yarns) are fused together. However, the fused portion 50 may also be formed so that at least a portion of the multifilament fibers (yarns) are fused together. The size of the fused portion 50 is not particularly limited, but can be, for example, 0.015 mm to 0.7 mm. The ratio of the unmelted portion of the fused portion 50 to the total area of ​​the main body portion 10 can be 3% or more and 100% or less. Furthermore, the occupancy rate of the fused portion 50 relative to the main body portion 10 when viewed in a plan view (viewed from the thickness direction X) can be 0.002% or more.

[0048] <Method of forming fused portions> Next, a method of forming the fused portions 50 in the medical sheet 100 will be described. Fig. 12 is a flowchart showing a method of forming the medical sheet 100 according to an embodiment. Fig. 13 is a diagram showing a needle member 320 used in the method of forming the fused portions 50 according to the first embodiment. Fig. 14 is a diagram showing the formation of through holes 11 in a sheet member S used to form the fused portions 50 in the medical sheet 100. The sheet member S is a sheet-like member that does not have through holes 11 formed therein and contains fibers made of a biodegradable material.

[0049] One example of a method for forming the fused portion 50 uses a forming member 300 having a base 310 with a circular flat base and numerous thermally conductive needle members 320 attached to the tip thereof, as shown in FIG. 13 . The base 310 of the forming member 300 incorporates a heatable component, such as ultrasonic waves, which can be used to generate heat in the base 310, thereby conducting the heat to the multiple needle members 320. In this embodiment, the forming member 300 is preheated. The needle members 320 are heated to a temperature above the melting point of the biodegradable fibers forming the main body 10 (for PGA, approximately 200°C, 218°C, or 218°C or higher; for PLGA, approximately 200°C, 215°C, or 215°C or higher). The needle members 320 are then inserted through the unprocessed sheet member S of the medical sheet 10 (S1), and the base 310 is brought into contact with the sheet member S, followed by pressing.

[0050] As a result, as shown in FIG. 14 , the area around the edge of the through hole 11 (corresponding to the area 12 near the main body 10) in the sheet member S is heated and melted by the heated needle member 320, and the fibers around the through hole 11 are melted and integrated, forming a fused portion 50 ( S2 ). In this embodiment, the needle member 320 has a shape in which a cylindrical portion and a conical portion having the same diameter are overlapped on the base 310. However, the shape of the needle member 320 is not particularly limited as long as it can form the through hole 11 with the desired hole diameter D. For example, the needle member 320 may be conical, pyramidal, cylindrical, tapered, or the like. Furthermore, the needle member 320 may have a diameter that is the same as or equivalent to the hole diameter D. In this embodiment, the diameter of the cylindrical portion of the needle member 320 and the diameter of the base of the conical portion are the same as the hole diameter D, and the cylindrical portion penetrates and perforates the sheet member S. However, as long as the through-hole 11 can be formed with the desired hole diameter D, the cylindrical portion does not need to penetrate the sheet member S.

[0051] 14 indicates a region of the sheet member S with which the needle members 320 come into direct contact, and region 15 indicates a region (first surface) with which the base 310 comes into direct contact. Regions 14 and 15 where the base 310 and the needle members 320 come into direct contact experience a greater amount of thermal load than regions (second surface) where the base 310 and the needle members 320 do not come into direct contact. Therefore, when viewed from the thickness direction X, one side of the sheet member S (front side, regions 14 and 15 where the base 310 and the needle members 320 come into direct contact, first surface) has more melted fibers and is more rigid than the other side (back side, regions where the base 310 and the needle members 320 do not come into direct contact, second surface).

[0052] 14 , the surface (region 15) of the sheet member S that contacts the base 310 is an uneven plane due to the fibers, and therefore there are portions that do not directly contact the base 310. The through-holes 11 are formed by avoiding the fibers of the sheet member S at the edge (corresponding to the region 12 near the main body 10) that is perforated by the needle members 320. As a result, the region 12 near the through-holes 11 has a higher fiber density than the distal region 13. In other words, the density of the through-holes 11 is higher than the density of the surface of the sheet member S. The region 15, which is heated by contact with the base 310 and where the fibers are partially melted and fused, is formed on only one side of the main body 10, and therefore the main body 10 can be provided with a certain degree of both flexibility and rigidity. Note that, on one side (front side, regions 14 and 15 where the base 310 and the needle member 320 are in direct contact, first surface) when viewed from the thickness direction X where the base 310 is in direct contact, the fused portion 50 is formed in the proximal portion 12 and the distal portion 13. On the other side (back side, region where the base 310 and the needle member 320 are not in direct contact, second surface) where the base 310 and the needle member 320 are not in direct contact, the fused portion 50 is formed only in the proximal portion 12. Regions away from the vicinity of the needle member 320 (corresponding to the distal portion 13 of the main body 10) are not completely melted by heat, but are slightly melted by heat conduction, forming the fused portion 50 in a state where the fibers are not completely melted. The fused portion 50 may be formed by fusing threads between multifilaments or by fusing bundled multifilaments together. However, fusion of bundled multifilaments together is expected to result in higher rigidity.

[0053] The number of sheet members S used to form the main body 10 is not particularly limited, and may be one or two or more, but is preferably two to eight, and four is more preferred because it provides a good balance between heating conditions and strength. By forming the through holes 11 while applying heat, the periphery of the edges is melted, making it easier to maintain the shape of the through holes 11.

[0054] After applying heat to the needle members 320, the sheet member S is cooled (S3), and the needle members 320 are removed from the sheet member S (S4). The cooling method is not particularly limited, and natural cooling or forced cooling using air or the like may be used. Cooling may be performed while the needle members 320 remain inserted, or after the needle members 320 are removed from the sheet member S. When the heated needle members 320 are punctured and processed as described above, and then the needle members 320 are separated from the sheet member S and cooled, protrusions may be formed around the edges. These protrusions facilitate positioning. Furthermore, the hardness of the sheet member S and the size and distribution of the through holes can be adjusted by changing the temperature, time, and pressure of the heat press, as well as the diameter and pitch of the needle members.

[0055] As described above, the medical sheet 100 according to this embodiment has a sheet-like main body 10 containing fibers made of a biodegradable material. The main body 10 has a plurality of through-holes 11 formed therein and a fused portion 50 formed by gathering and fusing fibers around the through-holes 11. This configuration makes it easier to maintain the shape of the through-holes 11 in the main body 10. Furthermore, configuring the fused portion 50 as described above increases the rigidity of the main body 10, thereby preventing or suppressing twisting or shifting of the medical sheet 100. Furthermore, increasing the rigidity of the main body 10 prevents or suppresses fraying when the medical sheet 100 is punched with a stapler such as the medical device 200, making punching easier.

[0056] Furthermore, the through holes 11 are formed along the thickness direction X of the main body 10. The fused portions 50 are configured to be formed along the thickness direction X. This can contribute to increasing the rigidity of the main body 10 and preventing or suppressing the occurrence of kinks in the medical sheet 100.

[0057] The fused portion 50 includes a first portion 51 where the fibers are completely fused, and a second portion 52 where the fibers have the shape of the fibers but are fused around the periphery. The presence of the first portion 51 as well as the second portion 52 in the fused portion 50 makes it easier for biological components to enter the gaps between the fibers, thereby making it easier to exert the healing effect.

[0058] The main body 10 also includes a proximal portion 12 located near the through hole 11 in the planar direction YZ of the main body 10, and a distal portion 13 located farther from the through hole 11 in the planar direction YZ than the proximal portion 12. The proximal portion 12 is configured to have a higher fiber density than the distal portion 13 by perforating the needle member 320 using the above-described method and positioning the fibers so that they are surrounded by the proximal portion 12. This configuration makes it easier to improve the strength of the main body 10, thereby making it easier to maintain the shape of the through hole 11.

[0059] The fused portions 50 are formed in the proximal portion 12 and distal portion 13 at a region 15 (first surface) that is in direct contact with the base portion 310 and the needle member 320 in the thickness direction X of the main body portion 10. The fused portions 50 are formed only in the proximal portion 12 on the side (second surface) opposite to the region 15 in the thickness direction X. This configuration makes it easier to maintain the shape of the through-holes 11, and prevents or suppresses fraying when the medical sheet 100 is punched with the medical device 200.

[0060] The main body 10 is made of multifilament fibers. The fused portion 50 can be configured such that at least some of the multifilaments are fused together. This configuration can easily improve the strength of the main body 10.

[0061] Furthermore, the method for manufacturing the medical sheet 100 is configured such that a heated needle member 320 is pierced through a sheet member S containing fibers made of a biodegradable material to form a through-hole 11, and the heated needle member 320 forms a fused portion 50 in the fibers surrounding the through-hole 11. By configuring it in this manner, a medical sheet 100 can be manufactured in which the main body 10 has high rigidity and is less likely to twist.

[0062] Furthermore, when the heated needle members 320 are penetrated through the sheet member S, the needle members 320 are heated to a temperature equal to or higher than the melting point of the fibers or the temperature at which the fibers melt. By configuring in this manner, the periphery of the through-hole 11 can be melted to form a fused portion 50 in the fibers around the through-hole 11.

[0063] In this embodiment, the base 310 on which the needle member 320 is placed is brought into contact with the sheet member S, and the base 310 is preheated to heat the needle member 320 and form the fused portion 50. This configuration makes it possible to form the fused portion 50 that can increase the rigidity of the main body 10 and make it less likely to twist.

[0064] In this embodiment, the sheet member S is cooled after heat is applied to the needle members 320, and then the sheet member S is removed from the needle members 320. By configuring in this manner, a medical sheet 100 having fused portions 50 formed thereon can be obtained.

[0065] 15 is a schematic diagram showing a manufacturing method according to a second embodiment for forming the fused portions 50 of the medical sheet 100. In this embodiment, the manufacturing method of the medical sheet 100 differs from that of the first embodiment, but the medical sheet 100 itself is the same as that of the first embodiment, and therefore a description of the medical sheet 100 will be omitted.

[0066] 15, multiple sheet members S containing a biodegradable material are stacked, and multiple thermally conductive needle members 320a, which do not have a base 310 as compared to the forming member 300 described in the first embodiment, are punctured into the sheet members to form through holes 11 in the sheet members S (S1). The multiple stacked sheet members S containing a biodegradable material may each have a different shape pattern of the through holes 11. For example, multiple sheet members S having through holes 11 arranged in two or more different shape patterns may be selected from the shape patterns of the through holes 11 of the main body 10 shown in FIGS. 3 to 6, and stacked.

[0067] Then, with the needles 320a puncturing the sheet member S, the needles 320a are maintained at a high temperature for a predetermined time. In this embodiment, the predetermined temperature can be set to a temperature at which the above-mentioned fibers melt or any temperature equal to or higher than the melting point of the above-mentioned fibers. As a result, the fused portions 50 are formed in the sheet member S (S2). In this embodiment, the fused portions 50 are formed (only) in the vicinity portions 12 on both sides (first surface and second surface) in the thickness direction X. After the needles 320a are heated, the sheet member S is cooled (S3), and the needles 320a are removed from the sheet member S (S4).

[0068] As described above, in this embodiment, the fused portion 50 is formed in the vicinity portion 12 on either side in the thickness direction X. By configuring in this manner, the shape of the through hole 11 can be easily maintained.

[0069] When the needle members 320a are heated after penetrating the sheet member S to form the through holes 11, the needle members 320a are maintained at a temperature equal to or higher than the melting point of the fibers. By configuring in this manner, the periphery of the through holes 11 can be melted to form fused portions 50 in the fibers around the through holes 11.

[0070] Furthermore, when the needle members 320a are penetrated through the sheet member S, multiple sheets S are stacked together and the needle members 320a are penetrated through the sheet members S. Then, with the needle members 320a penetrated through the sheet members S, the needle members 320a are maintained at a high temperature for a predetermined period of time. This configuration also makes it possible to obtain a medical sheet 100 in which fused portions 50 are formed in the fibers that make up the sheet member S.

[0071] The present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the claims. In the first embodiment, the sheet member S is punctured with preheated needle members 320. However, the fibers may be processed by needle punching to be more entangled with each other than before needle punching. This promotes entanglement between the fibers, which is expected to increase the rigidity of the main body portion 10 when the fibers are fused together. Furthermore, in the second embodiment, needle punching may be performed on the sheet member S before the fused portions 50 are formed. Needle punching can promote entanglement between the fibers of multiple sheet members S. Furthermore, needle punching can loosen multifilaments, which are made up of multiple fibers clumped together, and promote entanglement between the fibers. Promoting entanglement between the fibers makes it easier to form the fused portions 50 when the fibers are fused together, thereby increasing the rigidity of the medical sheet 100.

[0072] In the first embodiment, the fused portion 50 is formed by piercing the sheet member S with the preheated needle member 320, but the base 310 may be heated after the needle member 320 has pierced the sheet member S without heating it. This configuration also makes it possible to form the fused portion 50 that can increase the rigidity of the main body 10 and make it less likely to twist. In the second embodiment, the needle member 320a is maintained at a high temperature for a predetermined period of time after piercing the sheet member S with the needle member 320a, but the needle member 320a may be heated before piercing the sheet member S with the needle member 320a.

[0073] This application is based on Japanese Patent Application No. 2023-164236, filed on September 27, 2023, the disclosure of which is incorporated by reference in its entirety.

[0074] 10 main body portion, 11 through hole, 12 proximal portion, 13 distal portion, 50 fused portion, 51 first portion, 52 second portion, 100, 100a medical sheet, 310 base portion, 320, 320a needle member, S sheet member, X thickness direction, YZ surface direction.

Claims

1. A medical sheet having a sheet-like main body containing fibers made of a biodegradable material, the main body having a plurality of through-holes formed therein and fused portions formed by gathering and fusing the fibers around the through-holes.

2. The medical sheet according to claim 1, wherein the through holes are formed along the thickness direction of the main body portion, and the fused portions are formed along the thickness direction.

3. The medical sheet according to claim 1, wherein the fused portion comprises a portion where the fibers are completely fused and a portion where the fibers are fused around their peripheries while maintaining their shape.

4. A medical sheet as described in claim 1, wherein the main body portion comprises a proximal portion located near the through-hole in the surface direction of the main body portion, and a distal portion that is farther away from the through-hole in the surface direction than the proximal portion, and the fibers are present at a higher density in the proximal portion than in the distal portion.

5. The medical sheet according to claim 4, wherein the fused portion is formed in the adjacent portion.

6. A medical sheet as described in claim 4, wherein the main body portion has a first surface and a second surface formed on the opposite side of the first surface, and the fused portion is formed in the proximal portion and the distal portion of the first surface, and is formed only in the proximal portion of the second surface.

7. The medical sheet according to claim 1, wherein the main body portion is made of multifilaments of the fiber, and the fused portion is formed by at least a portion of the multifilaments being fused together.

8. A method for manufacturing a medical sheet, comprising: penetrating a sheet member containing fibers made of a biodegradable material with a needle to form a through-hole; and then heating the needle while the needle is still penetrating the sheet member; or penetrating the heated needle into the sheet member to form a fused portion in the fibers around the through-hole.

9. A method for manufacturing a medical sheet as described in claim 8, wherein when the needle is heated after penetrating the sheet member to form the through hole, or when the heated needle is penetrated into the sheet member, the needle is heated to a temperature above the melting point of the fiber.

10. A method for manufacturing a medical sheet as described in claim 8, wherein when the needle is heated after penetrating the sheet member to form the through hole, or when the heated needle is penetrated into the sheet member, the needle is heated to a temperature above the melting point of the fiber.

11. A method for manufacturing a medical sheet as described in claim 8, in which the needles are heated after piercing the sheet member to form the through holes, and the needles are heated by heating the planar base on which the needles are placed, while the base is in contact with the sheet member, thereby heating the needles and forming the fused portions.

12. A method for manufacturing a medical sheet as described in claim 8, wherein when the needle is heated after penetrating the sheet member to form the through hole, or when the heated needle is penetrated into the sheet member, the needle is penetrated into the sheet member with multiple sheet members stacked on top of each other, and the needle is heated by maintaining the needle at a predetermined temperature for a predetermined period of time.

13. A method for manufacturing a medical sheet as described in claim 8, wherein the fibers of the plurality of sheet members are needle-punched before the needles are pierced through the sheet members, and the fibers of the plurality of sheet members are entangled with each other before the needle-punching is performed.

14. The method for manufacturing a medical sheet according to claim 8, wherein the sheet member is cooled after applying heat to the needles, and the needles are removed from the sheet member.

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