Artificial blood vessel and method for manufacturing artificial blood vessel

Abstract

Provided is an artificial blood vessel having an inner peripheral surface that has a favorable effect on blood flow and a method for manufacturing an artificial blood vessel having an inner peripheral surface that has a favorable effect on blood flow. The artificial blood vessel includes a tubular sheet that defines a space for blood flow. The tubular sheet includes an ion-implanted layer as an inner layer. The ion-implanted layer includes polytetrafluoroethylene as a main component. An inner peripheral surface of the ion-implanted layer is composed of a roughened surface that includes polytetrafluoroethylene as a main component.

Description

Technical Field

[0001] This invention relates to artificial blood vessels and methods for manufacturing artificial blood vessels. Background Technology

[0002] Prosthetic materials used to construct artificial blood vessels are known.

[0003] As a related technology, Patent Document 1 discloses a bio-repair material with affinity for biological tissue adhesives. Patent Document 1 describes irradiating polytetrafluoroethylene with an ion beam to improve adhesion to fibrin glue.

[0004] Previously, irradiating polytetrafluoroethylene (PTFE) with an ion beam was specifically performed to improve its adhesion to tissues or fibrin glue. On the other hand, using the ion-irradiated surface of PTFE as a surface defining a lumen for bodily fluid flow was neither previously practiced nor known. In particular, irradiating the inner circumferential surface of a cylindrical body with an ion beam is physically difficult, and therefore, irradiating the inner circumferential surface of an artificial blood vessel made of PTFE was neither previously practiced nor known.

[0005] Patent Document 2 discloses a method for manufacturing an antithrombotic material. Patent Document 2 describes coating the inner wall of an ePTFE tube with a biopolymer material and irradiating the biopolymer material with an ion beam. However, Patent Document 2 does not describe implanting ions into the ePTFE to roughen its surface. Existing technical documents Patent documents

[0006] Patent Document 1: Japanese Patent No. 4445697 Patent Document 2: Japanese Patent Application Publication No. 9-299474 Summary of the Invention The problem that the invention aims to solve

[0007] The purpose of this invention is to provide an artificial blood vessel with an inner peripheral surface that is beneficial to blood flow and a method for manufacturing the artificial blood vessel with an inner peripheral surface that is beneficial to blood flow. Methods for solving problems

[0008] The embodiments of the present invention relate to the artificial blood vessels and the method for manufacturing the artificial blood vessels as shown below.

[0009] (1) An artificial blood vessel, wherein, The artificial blood vessel has a cylindrical sheet that defines a space for blood flow. The cylindrical sheet contains the ion-implanted layer as an inner layer. The main component of the ion implantation layer is polytetrafluoroethylene. The inner peripheral surface of the ion implantation layer is composed of a roughened surface with polytetrafluoroethylene as the main component. (2) According to the artificial blood vessel described in (1) above, wherein, The ion-implanted layer consists of a single layer in which elements implanted by ion implantation are mixed and present in the polytetrafluoroethylene. (3) The artificial blood vessel according to (1) or (2) above, wherein, At least a portion of the roughened surface, which is mainly composed of polytetrafluoroethylene, is exposed to the space in which the blood flows. (4) The artificial blood vessel according to any one of (1) to (3) above, wherein, The tubular sheet is a seamless structure. (5) The artificial blood vessel according to any one of (1) to (4) above, wherein, At least a portion of the outer peripheral surface of the tubular sheet is a second roughened surface. (6) The artificial blood vessel according to (5) above, wherein, At least a portion of the outer peripheral surface of the tubular sheet is an unroughened surface. (7) The artificial blood vessel according to any one of (1) to (6) above, wherein, The inner peripheral surface of the ion implantation layer carries a drug. (8) The artificial blood vessel according to (7) above, wherein, The drug contains a blood clotting inhibitor. (9) A method for manufacturing an artificial blood vessel, wherein the manufacturing method comprises: The process of preparing tubular sheets containing polytetrafluoroethylene; and The process of irradiating the polytetrafluoroethylene with an ion beam to form an ion implantation layer on the tubular sheet. The cylindrical sheet contains the ion-implanted layer as an inner layer. The main component of the ion implantation layer is polytetrafluoroethylene. The inner peripheral surface of the ion implantation layer is composed of a roughened surface with polytetrafluoroethylene as the main component. (10) The method for manufacturing artificial blood vessels according to (9) above, wherein, The angle between the direction parallel to the length of the tubular sheet and the direction in which the ion beam is incident on the polytetrafluoroethylene is 45 degrees or more. (11) The method for manufacturing an artificial blood vessel according to (9) or (10) above, wherein, The manufacturing method includes a step of flipping the cylindrical sheet so that the outer surface of the cylindrical sheet becomes the inner surface. The process of irradiating the polytetrafluoroethylene with the ion beam includes irradiating the outer surface of the tubular sheet with the ion beam. In the process of flipping the tubular sheet, the outer surface that was irradiated by the ion beam becomes the inner surface. (12) The method for manufacturing an artificial blood vessel according to any one of (9) to (11) above, wherein, After performing the step of irradiating the polytetrafluoroethylene with the ion beam, a layer containing a reagent is attached to the surface of the ion implantation layer. (13) The method for manufacturing an artificial blood vessel according to any one of (9) to (12) above, wherein, The manufacturing method includes a step of irradiating the outer peripheral surface of the cylindrical sheet with an ion beam to form a second ion implantation layer on the cylindrical sheet. After performing the step of irradiating the outer peripheral surface of the tubular sheet with the ion beam, at least one of a bio-adhesive and a coating to prevent blood leakage is applied to the surface of the second ion implantation layer. The effects of the invention

[0010] According to the present invention, it is possible to provide an artificial blood vessel having an inner peripheral surface that is beneficial to blood flow and a method for manufacturing an artificial blood vessel having an inner peripheral surface that is beneficial to blood flow. Attached Figure Description

[0011] Figure 1 This is a schematic three-dimensional view of the artificial blood vessel in the first embodiment. Figure 2 This is a schematic cross-sectional view of the artificial blood vessel in the first embodiment. Figure 3 It is a schematic cross-sectional view showing the state of the artificial blood vessel in the first embodiment being installed in the first blood vessel and the second blood vessel. Figure 4 It is a schematic cross-sectional view showing the spread of the patient's tissue on the inner circumferential surface of the ion-implanted layer. Figure 5 This is a schematic cross-sectional view showing the state in which the inner peripheral surface of the end of the artificial blood vessel in the first embodiment is installed on the outer peripheral surface of the end of the patient's blood vessel. Figure 6 This is a schematic cross-sectional view showing the state of the artificial blood vessel being installed in the patient's blood vessel with the end face of the artificial blood vessel in contact with the end face of the patient's blood vessel in the first embodiment. Figure 7This is a schematic perspective view of the artificial blood vessel in a first variation of the first embodiment. Figure 8 This is a schematic cross-sectional view showing the state of the artificial blood vessel in the first variant of the first embodiment being installed in the first blood vessel and the second blood vessel. Figure 9 This is a schematic perspective view of the artificial blood vessel in a second variation of the first embodiment. Figure 10 This is a schematic cross-sectional view showing the state of the artificial blood vessel in the second variation of the first embodiment being installed in the first blood vessel and the second blood vessel. Figure 11 This is a schematic cross-sectional view showing the state of the artificial blood vessel carrying the drug in the first embodiment. Figure 12 This is a schematic cross-sectional view showing the state of the artificial blood vessel carrying the drug in a modified example of the first embodiment. Figure 13 It is a schematic perspective view illustrating an example of a tubular sheet prepared in the preparation process. Figure 14 It is a schematic cross-sectional view illustrating the irradiation of the inner circumferential surface of a cylindrical sheet by an ion irradiation device. Figure 15 It is a schematic cross-sectional view illustrating the irradiation of the outer surface of a cylindrical sheet by an ion irradiation device. Figure 16 This is a diagram that schematically illustrates the flipping of a tubular sheet. Figure 17 It is a schematic three-dimensional diagram that represents the state during the flipping process. Figure 18 It is a schematic cross-sectional view showing the state during the execution of the second irradiation process. Figure 19 It is a schematic cross-sectional view illustrating the situation where an ion beam is irradiated only a portion of the outer peripheral surface of a cylindrical sheet. Figure 20 It is a schematic cross-sectional view showing the state of the second ion implantation layer with a bio-adhesive attached after the second irradiation process has been performed. Figure 21 It is a schematic cross-sectional view showing the state after the second irradiation process, in which a coating to prevent blood leakage is applied to the surface of the second ion implantation layer. Figure 22 It is a schematic cross-sectional view showing the situation of irradiating an ion beam onto the end face of the first direction side of the cylindrical sheet. Figure 23It is a schematic cross-sectional view showing the irradiation of an ion beam onto the end face of the cylindrical sheet in the second direction. Figure 24 This is a flowchart illustrating an example of a method for manufacturing an artificial blood vessel according to the second embodiment. Detailed Implementation

[0012] Hereinafter, with reference to the accompanying drawings, the artificial blood vessel 1A in the embodiment and the method for manufacturing the artificial blood vessel 1 will be described. It should be noted that in the following description, components and parts with the same function will be labeled with the same reference numerals, and repeated descriptions of components and parts labeled with the same reference numerals will be omitted.

[0013] (Definition of the term) In this specification, the direction from the second end 23 of the tubular sheet 2 toward the first end 21 of the tubular sheet 2 is defined as the first direction DR1. Furthermore, the direction opposite to the first direction DR1 is defined as the second direction DR2. Figure 1 In the example described, the first direction DR1 and the second direction DR2 are aligned with the length direction of the tubular sheet 2.

[0014] (First Implementation) Reference Figures 1 to 12 The artificial blood vessel 1A in the first embodiment will be described. Figure 1 This is a schematic perspective view of the artificial blood vessel 1A in the first embodiment. Figure 2 This is a schematic cross-sectional view of the artificial blood vessel 1A in the first embodiment. Figure 3 This is a schematic cross-sectional view showing the state in which the artificial blood vessel 1A in the first embodiment is installed in the first blood vessel 9a and the second blood vessel 9b. Figure 4 It is a schematic cross-sectional view showing the state of the patient's tissue 90 spreading on the inner peripheral surface 31 of the ion implantation layer 30. Figure 5 This is a schematic cross-sectional view showing the state in which the inner peripheral surface of the end of the artificial blood vessel 1A in the first embodiment is installed on the outer peripheral surface of the end of the patient's blood vessel 9. Figure 6 This is a schematic cross-sectional view showing the state in which the artificial blood vessel 1A is installed in the patient's blood vessel 9 with the end face of the artificial blood vessel 1A in contact with the end face of the patient's blood vessel 9 in the first embodiment. Figure 7 This is a schematic perspective view of the artificial blood vessel 1A in a first variation of the first embodiment. Figure 8 This is a schematic cross-sectional view showing the state in which the artificial blood vessel 1A in the first variant of the first embodiment is installed in the first blood vessel 9a and the second blood vessel 9b. Figure 9 This is a schematic perspective view of the artificial blood vessel 1A in a second variation of the first embodiment. Figure 10 This is a schematic cross-sectional view showing the state in which the artificial blood vessel 1A is installed in the first blood vessel 9a and the second blood vessel 9b in a second variation of the first embodiment. Figure 11 This is a schematic cross-sectional view showing the state of the artificial blood vessel 1A carrying the drug K in the first embodiment. Figure 12 This is a schematic cross-sectional view showing the state of the artificial blood vessel 1A carrying the drug K in a modified example of the first embodiment.

[0015] like Figure 1 As illustrated, the artificial blood vessel 1A in the first embodiment includes a tubular sheet 2. The tubular sheet 2 defines a space SP for blood flow.

[0016] like Figure 2 As illustrated, the cylindrical sheet 2 contains the ion-implanted layer 30 as an inner layer. The main component of the ion-implanted layer 30 is polytetrafluoroethylene.

[0017] exist Figure 2 In the described example, the inner peripheral surface 31 of the ion implantation layer 30 is composed of a roughened surface 31r primarily composed of polytetrafluoroethylene (PTFE). In other words, the proportion of PTFE constituting the roughened surface in the total material constituting the roughened surface 31r is 50% or more by weight. The proportion of PTFE constituting the roughened surface in the total material constituting the roughened surface 31r can be 70% or more by weight, 90% or more by weight, 95% or more by weight, or 99% or more by weight.

[0018] The entire cylindrical sheet 2 may contain polytetrafluoroethylene (PTFE) as a major component. In other words, PTFE may account for 50% or more of the total materials constituting the cylindrical sheet 2. Alternatively, the proportion of PTFE in the total materials constituting the cylindrical sheet 2 may be 70% or more, 90% or more, 95% or more, or 99% or more. Alternatively, the cylindrical sheet 2 may also be a laminate formed by an inner layer of PTFE and an outer layer of other materials.

[0019] exist Figure 2 In the described example, the roughened surface 31r is formed by the inner peripheral surface 31 of the ion-implanted layer 30. In this specification, "ion-implanted layer 30" refers to a layer whose physical and / or chemical properties are altered by implanting ionized elements. Figure 2 In the described example, the ion implantation layer 30 has a plurality of tiny recesses 30d on its surface by ion implantation.

[0020] The roughened surface 31r, primarily composed of polytetrafluoroethylene (PTFE) (more specifically, the inner circumferential surface 31 of the ion-implanted layer 30), has a beneficial effect on blood flow. More specifically, the roughened surface 31r, primarily composed of PTFE (more specifically, the inner circumferential surface 31 of the ion-implanted layer 30), acts like a rib, reducing the frictional resistance between the inner surface of the tubular sheet 2 and the blood flowing within it. Thus, blood flow FL in patients with the artificial blood vessel 1A becomes better (see reference). Figure 3 The roughening degree of the roughened surface 31r can be set to a suitable value for the Reynolds number of the blood flowing within the cylindrical sheet 2. For example, the roughening degree of the roughened surface 31r can be set to a laminar flow of blood near the inner circumferential surface 31.

[0021] Compared to unroughened surfaces, roughened surfaces 31r, primarily composed of polytetrafluoroethylene, facilitate cell spreading in patients. Therefore, as... Figure 4 As illustrated, after the artificial blood vessel 1A is anastomosed with the patient's blood vessel 9, the roughened surface 31r of the tubular sheet 2 is relatively quickly covered by the patient's tissue 90 (more specifically, the patient's cells). After the roughened surface 31r of the tubular sheet 2 is covered by the patient's tissue 90, it is expected that the tubular sheet 2, like the patient's blood vessel 9, will influence blood flow.

[0022] (Any additional structure) Next, any additional structures that can be used in the artificial blood vessel 1A of the first embodiment will be described.

[0023] (Expanded polytetrafluoroethylene) In this specification, polytetrafluoroethylene (PTFE) is preferably expanded polytetrafluoroethylene (hereinafter referred to as "ePTFE"). ePTFE is polytetrafluoroethylene that has undergone a stretching process (more specifically, polytetrafluoroethylene stretched under heat). ePTFE is, for example, expanded porous polytetrafluoroethylene manufactured using the method described in U.S. Patent Nos. 3,953,566 or 4,187,390. Alternatively, the polytetrafluoroethylene in this specification may be non-expanded polytetrafluoroethylene.

[0024] (Ion implantation layer 30) The ion implantation layer 30 is a layer in polytetrafluoroethylene (PTFE) containing ion-implanted elements. It should be noted that a portion of the ion-implanted elements can detach from the ion implantation layer 30. The elements ion-implanted into the PTFE can be argon, neon, or other elements. In other words, the ion implantation layer 30 can be a layer in PTFE containing argon, a layer in PTFE containing neon, or a layer in PTFE containing other elements.

[0025] like Figure 2 As illustrated, the ion implantation layer 30 may be composed of a monolayer 30-1 in which elements implanted by ion implantation (e.g., argon or neon) are mixed in polytetrafluoroethylene.

[0026] like Figure 2 As illustrated, at least a portion of the roughened surface 31r, primarily composed of polytetrafluoroethylene (PTFE), is exposed to the blood flow space SP. The roughened surface 31r, substantially entirely composed of PTFE, can be exposed to the blood flow space SP. The roughened surface 31r has a beneficial effect on blood flow. Furthermore, compared to a non-roughened surface, the roughened surface 31r facilitates the spread of the patient's cells (more specifically, endothelial cells).

[0027] The inner surface of the tubular sheet 2 can be substantially roughened as a whole to a surface 31r (more specifically, the inner circumferential surface 31 of the ion implantation layer 30). In this case, the inner circumferential surface 31 of the ion implantation layer 30 generally helps to reduce frictional resistance to blood flow. In addition, the patient's tissue 90 (more specifically, the patient's endothelial cells) can easily spread on the inner circumferential surface 31 of the ion implantation layer 30 as a whole.

[0028] The maximum height roughness Rz of the inner peripheral surface 31 of the ion implantation layer 30 is, for example, 8 μm or more. It should be noted that, in this specification, the "maximum height roughness Rz" is measured based on JIS B 0601:2013 (corresponding to international standard ISO 4287:1997, Amd.1:2009).

[0029] (Seamless cylindrical sheet material 2) The tubular sheet 2 is preferably a seamless structure. In this case, since the inner surface of the tubular sheet 2 is seamless, blood flow is smoother. Figure 1 In the examples described, the tubular sheet 2 is a seamless tubular sheet.

[0030] The seamless cylindrical sheet 2 is formed, for example, by extrusion molding. More specifically, the seamless cylindrical sheet 2 is formed by extruding a raw material with polytetrafluoroethylene as the main component into a cylindrical shape. In contrast, when the cylindrical sheet 2 is formed by rolling up a flat sheet, seams (in other words, gaps) are inevitably present.

[0031] After forming the tubular sheet 2, its outer surface can be roughened by ion irradiation. After the outer surface of the tubular sheet 2 is roughened, it can be flipped so that its outer surface becomes its inner surface. This flipping transforms the inner surface of the tubular sheet 2 into a roughened surface 31r. This flipping overcomes the technical difficulty of using the inner layer of the tubular sheet 2 as an ion implantation layer.

[0032] (Tubular sheet 2) The artificial blood vessel 1A in the first embodiment includes a tubular sheet 2. More specifically, the artificial blood vessel 1A is composed of the tubular sheet 2. The film thickness of the tubular sheet 2 is, for example, 0.01 mm or more and 2 mm or less. The film thickness of the tubular sheet 2 can be 0.05 mm or more and 1.5 mm or less, 0.1 mm or more and 1.0 mm or less, or 0.1 mm or more and 0.5 mm or less.

[0033] (First end 21 of cylindrical sheet 2) exist Figure 3 In the described example, the tubular sheet 2 has a first end 21 that is installed on the patient's first blood vessel 9a. Figure 3 In the described example, the first end portion 21 is attached to the end of the patient's first blood vessel 9a via an end-to-end anastomosis. Alternatively, the first end portion 21 can be attached to the patient's first blood vessel 9a via an end-to-side anastomosis. The first end portion 21 can also be attached to the patient's first blood vessel 9a by suturing. Alternatively or additionally, the first end portion 21 can be attached to the patient's first blood vessel 9a using a biological adhesive (e.g., fibrin glue). Any known method can be used to attach the first end portion 21 to the first blood vessel 9a.

[0034] In the first end portion 21, the first contact layer 21c that contacts the first blood vessel 9a preferably includes a roughened surface (more specifically, the surface of the ion implantation layer) (see reference). Figure 7 and Figure 8 In this configuration, the patient's cells readily spread between the first contact layer 21c and the first blood vessel 9a. Therefore, blood is less likely to leak between the first contact layer 21c and the first blood vessel 9a. A bio-adhesive can be applied to the first contact layer 21c. If the first contact layer 21c includes a roughened surface (more specifically, the surface of the ion-implanted layer), this roughened surface facilitates the carrying of the bio-adhesive. The first contact layer 21c may be a layer in which a coating preventing blood leakage is applied to the roughened surface (more specifically, the surface of the ion-implanted layer).

[0035] like Figure 3 As illustrated, the first end 21 of the tubular sheet 2 can be configured to be installed in the first blood vessel 9a while inserted inside the end of the first blood vessel 9a. Alternatively, such as... Figure 5 As illustrated, the first end 21 of the tubular sheet 2 can be mounted on the first blood vessel 9a when the end of the first blood vessel 9a is inserted into the inside of the first end 21 of the tubular sheet 2.

[0036] Furthermore, as an alternative, such as Figure 6 As illustrated, the first end 21 of the tubular sheet 2 can be mounted on the first blood vessel 9a when the end face 21e of the first end 21 of the tubular sheet 2 is in contact with the end face of the first blood vessel 9a.

[0037] exist Figure 6 In the described example, the end face 21e of the first end 21 of the cylindrical sheet 2 (more specifically, the end face 21e on the first direction DR1 side of the cylindrical sheet 2) includes a roughened surface 21r. Figure 6 In the described example, the roughened surface 21r is formed by the surface of the ion-implanted layer 20. When the end face 21e includes the roughened surface 21r (more specifically, the surface of the ion-implanted layer 20), the patient's cells rapidly spread on the roughened surface 21r. Therefore, leakage of blood from the gap between the end face 21e and the end face of the first blood vessel 9a can be prevented. It should be noted that, from the viewpoint of preventing blood leakage from this gap before the patient's cells spread on the roughened surface 21r (more specifically, the surface of the ion-implanted layer 20), a bio-adhesive can be applied to the roughened surface 21r.

[0038] like Figure 4 As illustrated, even when the first end 21 of the tubular sheet 2 is inserted inside the end of the first blood vessel 9a, the patient's tissue 90 (more specifically, the patient's cells) rapidly spreads on the roughened surface 21r (more specifically, the surface of the ion implantation layer 20) on the first direction DR1 side of the first end 21. Therefore, blood leakage can be prevented, and blood flow near the end face 21e on the first direction DR1 side of the tubular sheet 2 can be improved.

[0039] (Second end portion 23 of cylindrical sheet 2) exist Figure 3 In the described example, the tubular sheet 2 has a second end 23 that is installed on the patient's second blood vessel 9b. Figure 3In the described example, the second end portion 23 is attached to the end of the patient's second blood vessel 9b via an end-to-end anastomosis. Alternatively, the second end portion 23 can be attached to the patient's second blood vessel 9b via an end-to-side anastomosis. The second end portion 23 can also be attached to the patient's second blood vessel 9b by suture. Alternatively or additionally, the second end portion 23 can be attached to the patient's second blood vessel 9b using a biological adhesive (e.g., fibrin glue). Any known method can be used to attach the second end portion 23 to the second blood vessel 9b.

[0040] In the second end portion 23, the second contact layer 23c that contacts the second blood vessel 9b preferably includes a roughened surface (more specifically, the surface of the ion implantation layer) (see reference). Figure 7 and Figure 8 In this configuration, the patient's cells readily spread between the second contact layer 23c and the second blood vessel 9b. Therefore, blood is less likely to leak between the second contact layer 23c and the second blood vessel 9b. A bio-adhesive can be applied to the second contact layer 23c. When the second contact layer 23c includes a roughened surface (more specifically, the surface of the ion-implanted layer), the second contact layer 23c is advantageous for carrying the bio-adhesive. The second contact layer 23c can be a layer with a coating applied to the roughened surface (more specifically, the surface of the ion-implanted layer) to prevent blood leakage.

[0041] like Figure 3 As illustrated, the second end 23 of the tubular sheet 2 can be installed in the second blood vessel 9b with the latter inserted inside the end of the second blood vessel 9b. Alternatively, such as... Figure 5 As illustrated, the second end 23 of the tubular sheet 2 can be mounted on the second blood vessel 9b when the end of the second blood vessel 9b is inserted into the inside of the second end 23 of the tubular sheet 2.

[0042] Furthermore, as an alternative, such as Figure 6 As illustrated, the second end 23 of the tubular sheet 2 can be mounted on the second blood vessel 9b when the end face 23e of the second end 23 of the tubular sheet 2 is in contact with the end face of the second blood vessel 9b.

[0043] The end face 23e of the second end 23 of the tubular sheet 2 (more specifically, the end face 23e on the second direction DR2 side of the tubular sheet 2) may include a roughened surface 23r. The roughened surface 23r may be formed by the surface of the ion implantation layer.

[0044] (Outer peripheral surface 41 of cylindrical sheet 2 ) like Figure 1 As illustrated, the outer peripheral surface 41 of the tubular sheet 2 can be a non-roughened surface 41s (more specifically, a smooth surface). Figure 1In the example described, the outer peripheral surface 41 of the tubular sheet 2 is substantially entirely an unroughened surface 41s (more specifically, a smooth surface). It should be noted that, in this specification, "unroughened surface" refers to a surface that has not undergone roughening treatment and whose maximum height roughness Rz is less than that of the roughened surface 31r.

[0045] exist Figure 1 and Figure 7 In the described example, at least a portion of the outer peripheral surface 41 of the tubular sheet 2 (e.g., the outer peripheral surface 415 of the central region 25 along the length direction of the tubular sheet 2) is an unroughened surface 41s. The unroughened surface 41s is less likely to adhere to the patient's internal tissues.

[0046] exist Figure 7 and Figure 9 In the described example, at least a portion of the outer peripheral surface 41 of the tubular sheet 2 is a roughened surface 41r. The outer peripheral surface 41 of the tubular sheet 2 preferably includes a roughened surface 41r primarily composed of polytetrafluoroethylene (PTFE). The outer peripheral surface 41 of the tubular sheet 2 can substantially entirely contain PTFE as its primary component.

[0047] like Figure 8 and Figure 10 As illustrated, the roughened surface 41r is formed by the surface of the ion-implanted layer 40. The ion-implanted layer 40 is, for example, a layer in which the ion-implanted element is mixed in polytetrafluoroethylene. The element implanted into the cylindrical sheet 2 (more specifically, the element ion-implanted into polytetrafluoroethylene) is, for example, argon, neon, etc. The ion-implanted layer 40 can be a layer in which argon is mixed in polytetrafluoroethylene, or it can be a layer in which neon is mixed in polytetrafluoroethylene.

[0048] The maximum height roughness Rz of the roughened surface 41r is, for example, 8 μm or more.

[0049] like Figure 7 and Figure 9 As illustrated, the outer peripheral surface 411 of the first end 21 of the tubular sheet 2 can be a roughened surface 411r. The roughened surface 411r is formed by the surface of the ion implantation layer 40.

[0050] When the outer peripheral surface 411 of the first end 21 of the tubular sheet 2 is a roughened surface 411r (more specifically, the surface of the ion implantation layer 40), after the outer peripheral surface 411 of the first end 21 is installed on the first blood vessel 9a, the patient's cells can easily spread between the outer peripheral surface 411 and the first blood vessel 9a. Therefore, blood is less likely to leak from between the outer peripheral surface 411 and the first blood vessel 9a. As an alternative or additional solution, such as Figure 5As illustrated, the inner circumferential surface 311 of the first end 21 of the tubular sheet 2 can be a roughened surface 311r (more specifically, the surface of the ion implantation layer 30). In this case, after the inner circumferential surface 311 of the first end 21 is installed on the first blood vessel 9a, the patient's cells can easily spread between the inner circumferential surface 311 and the first blood vessel 9a. Therefore, blood is less likely to leak from between the inner circumferential surface 311 and the first blood vessel 9a.

[0051] like Figure 10 As illustrated, the outer peripheral surface 415 of the central region 25 along the longitudinal direction of the tubular sheet 2 can be a roughened surface 415r (more specifically, the surface of the ion implantation layer 40). In this case, the outer peripheral surface 415 of the central region 25 along the longitudinal direction of the tubular sheet 2 can be fixed to the patient's in vivo tissue PT. This fixation can be achieved by contacting the roughened surface 415r with the in vivo tissue PT, allowing the patient's tissue (more specifically, the patient's cells) to spread on the roughened surface 415r. As an alternative or additional method, this fixation can be performed using biological adhesives or sutures, etc.

[0052] like Figure 9 As illustrated, the outer peripheral surface 41 of the tubular sheet 2 can be substantially entirely roughened surface 41r (more specifically, the surface of the ion implantation layer 40).

[0053] In this specification, to distinguish the terminology of the "roughened surface 31r" included in the inner layer of the tubular sheet 2 from the "roughened surface 41r" included in the outer layer of the tubular sheet 2, the latter is referred to as the "second roughened surface 41r". In this specification, to distinguish the terminology of the "roughened surface 31r" included in the inner layer of the tubular sheet 2 from the "roughened surface 21r" included in the end face 21e of the first end portion 21 of the tubular sheet 2, the latter is referred to as the "third roughened surface 21r". In this specification, to distinguish the terminology of the "roughened surface 31r" included in the inner layer of the tubular sheet 2 from the "roughened surface 23r" included in the end face 23e of the second end portion 23 of the tubular sheet 2, the latter is referred to as the "fourth roughened surface 23r".

[0054] In this specification, to distinguish the terminology of the "ion implantation layer 30" on the inner surface side of the cylindrical sheet 2 from the "ion implantation layer 40" on the outer surface side of the cylindrical sheet 2, the latter is referred to as the "second ion implantation layer 40". In this specification, to distinguish the terminology of the "ion implantation layer 30" on the inner surface side of the cylindrical sheet 2 from the "ion implantation layer 20" on the end face 21e side of the cylindrical sheet 2 in the first direction DR1, the latter is referred to as the "third ion implantation layer 20".

[0055] The surface roughness (more specifically, the maximum height roughness Rz) of roughened surface 31r can be the same as that of the second roughened surface 41r. Alternatively, the surface roughness (more specifically, the maximum height roughness Rz) of roughened surface 31r can be different from that of the second roughened surface 41r. The function of roughened surface 31r (e.g., a function that benefits blood flow) differs from the function of the second roughened surface 41r (e.g., a function that improves adhesion to patient tissue). Therefore, the difference between the surface roughness (more specifically, the maximum height roughness Rz) of roughened surface 31r and the surface roughness (more specifically, the maximum height roughness Rz) of the second roughened surface 41r can be set according to the difference in their functions.

[0056] The surface roughness (more specifically, the maximum height roughness Rz) of roughened surface 31r can be the same as the surface roughness (more specifically, the maximum height roughness Rz) of the third roughened surface 21r. Alternatively, the surface roughness (more specifically, the maximum height roughness Rz) of roughened surface 31r can be different from the surface roughness (more specifically, the maximum height roughness Rz) of the third roughened surface 21r.

[0057] (Drug K) like Figure 11 and Figure 12 As illustrated, the inner peripheral surface 31 of the ion implantation layer 30 can support the drug K. Multiple tiny recesses 30d are formed on the inner peripheral surface 31 of the ion implantation layer 30 by ion implantation. These recesses 30d facilitate the support of the drug K.

[0058] The inner peripheral surface 31 of the ion implantation layer 30 carries an agent that inhibits blood coagulation (hereinafter referred to as "blood coagulation inhibitor K1"). In other words, the agent K carried by the inner peripheral surface 31 of the ion implantation layer 30 may include the blood coagulation inhibitor K1 (e.g., an anticoagulant, an antiplatelet drug). Since blood coagulation inhibitors are well known, a description of blood coagulation inhibitors is omitted.

[0059] As an alternative or additional option, the inner peripheral surface 31 of the ion implantation layer 30 may carry an agent K2 that regulates the spread of vascular endothelial cells. The agent K2 that regulates the spread of vascular endothelial cells may be an agent that stimulates the proliferation of vascular endothelial cells (e.g., an agent containing vascular endothelial growth factor (VEGF)) or a cell proliferation inhibitor that inhibits the proliferation of vascular endothelial cells. By regulating the spread of vascular endothelial cells with agent K2, the time required for the inner surface of the tubular sheet 2 to be covered by the patient's tissue (more specifically, the patient's endothelial cells) can be appropriately controlled.

[0060] exist Figure 11 and Figure 12 In the described example, a portion of the inner peripheral surface 31 of the ion implantation layer 30 is not covered by the agent K, but is exposed to the blood flow space SP. Alternatively, the entire inner peripheral surface 31 of the ion implantation layer 30 can be covered by the agent K. In these cases, the agent K is slowly released into the bloodstream, thus exposing the inner peripheral surface 31 of the ion implantation layer 30 to the blood flow space SP. After the inner peripheral surface 31 of the ion implantation layer 30 is exposed to the blood flow space SP, the inner peripheral surface 31 helps to reduce frictional resistance to blood flow. Additionally, the patient's tissue 90 (more specifically, the patient's endothelial cells) spreads on the inner peripheral surface 31 of the ion implantation layer 30.

[0061] (Second Implementation) Reference Figures 1 to 24 The manufacturing method of the artificial blood vessel 1 according to the second embodiment will be described. Figure 13 This is a schematic perspective view of an example of a tubular sheet 2 prepared in the preparation process. Figure 14 It is a schematic cross-sectional view showing the situation where an ion beam BM is irradiated from the ion irradiation device 8a onto the inner surface of the cylindrical sheet 2. Figure 15 This is a schematic cross-sectional view showing the irradiation of the outer surface 2t of the cylindrical sheet 2 by the ion irradiation device 8b. Figure 16 This is a schematic diagram illustrating the flipping of the tubular sheet 2. Figure 17 It is a schematic three-dimensional diagram that represents the state during the flipping process. Figure 18 It is a schematic cross-sectional view showing the state during the execution of the second irradiation process. Figure 19 This is a schematic cross-sectional view showing only a portion of the outer peripheral surface 41 of the cylindrical sheet 2 being irradiated with an ion beam BM2. Figure 20 This is a schematic cross-sectional view showing the state after the second irradiation process, with the bio-adhesive J attached to the surface of the second ion implantation layer 40. Figure 21 This is a schematic cross-sectional view showing the state of the second ion implantation layer 40 after the second irradiation procedure, with a coating to prevent blood leakage attached to the surface of the CT. Figure 22 This is a schematic cross-sectional view showing the irradiation of the end face 21e of the cylindrical sheet 2 in the first direction DR1 direction with an ion beam BM3. Figure 23 This is a schematic cross-sectional view showing the irradiation of the ion beam BM4 onto the end face 23e of the cylindrical sheet 2 in the second direction DR2. Figure 24 This is a flowchart illustrating an example of a method for manufacturing the artificial blood vessel 1 in the second embodiment.

[0062] In the second embodiment, the description focuses on the points that differ from the first embodiment. Furthermore, in the second embodiment, repetitive descriptions of matters already described in the first embodiment are omitted. Therefore, it is self-evident that, even without explicit explanation, matters already described in the first embodiment can be applied to the second embodiment. Conversely, matters described in the second embodiment can be used in the first embodiment.

[0063] In the method for manufacturing artificial blood vessels in the second embodiment, the artificial blood vessel 1 manufactured can be the artificial blood vessel 1A in the first embodiment, or it can be other artificial blood vessels.

[0064] like Figure 13 As illustrated, in the first step ST1, a tubular sheet 2 containing polytetrafluoroethylene is prepared. The first step ST1 is a preparation process.

[0065] like Figure 14 As illustrated, in the second step ST2, the polytetrafluoroethylene (PTFE) is irradiated with an ion beam BM. The second step ST2 is an irradiation process. The irradiation process (second step ST2) includes irradiating the PTFE with an ion beam BM to form an ion implantation layer 30 on the tubular sheet 2.

[0066] exist Figure 14 In the described example, the irradiation process (second step ST2) includes irradiating the inner surface of the cylindrical sheet 2 with an ion beam BM. By irradiating the inner surface of the cylindrical sheet 2 with the ion beam BM, the inner surface of the cylindrical sheet 2 becomes a roughened surface 31r. Furthermore, by irradiating the inner surface of the cylindrical sheet 2 with the ion beam BM, the inner surface of the cylindrical sheet 2 becomes the inner peripheral surface 31 of the ion implantation layer 30 (for example, see reference...). Figure 2 .).exist Figure 14 In the examples described, the ion irradiation device 8a is equipped with a magnet (e.g., a superconducting magnet 81) that deflects the ion beam BM.

[0067] Because the inner diameter of the artificial blood vessel is small, it is extremely difficult to irradiate the inner surface of the cylindrical sheet 2 with an ion beam BM. However, if the technology described in Japanese Patent Application Publication No. 5-128993 is applied to the manufacture of the artificial blood vessel 1, it is not impossible to irradiate the inner surface of the cylindrical sheet 2 with an ion beam BM.

[0068] As an alternative, such as Figure 15 and Figure 16 As illustrated, after performing the irradiation process (second step ST2), the cylindrical sheet 2 can be flipped so that the outer surface 2t of the cylindrical sheet 2 becomes the inner surface. By flipping, the inner surface of the cylindrical sheet 2 becomes the roughened surface 31r. In addition, by flipping, the inner surface of the cylindrical sheet 2 becomes the inner peripheral surface 31 of the ion implantation layer 30.

[0069] like Figure 1 , Figure 7 or Figure 9 As illustrated, the cylindrical sheet 2 contains an ion implantation layer 30 as an inner layer. The main component of the ion implantation layer 30 is polytetrafluoroethylene (PTFE). The inner circumferential surface 31 of the ion implantation layer 30 is formed by a roughened surface 31r mainly composed of PTFE.

[0070] In a second embodiment, a method for manufacturing an artificial blood vessel 1 having an inner peripheral surface 31 that has a beneficial effect on blood flow is provided.

[0071] (Any additional structure) Next, any additional structures that can be used in the manufacturing method of the artificial blood vessel 1 in the second embodiment will be described.

[0072] like Figure 13 As illustrated, in the first step ST1 (preparation process), a tubular sheet 2 containing polytetrafluoroethylene is prepared.

[0073] The tubular sheet 2 prepared in the preparation step (first step ST1) may contain polytetrafluoroethylene (PTFE) as a main component. In other words, the proportion of PTFE in the total materials constituting the tubular sheet 2 may be 50% by weight or more. The proportion of PTFE constituting the tubular sheet 2 in the total materials constituting the tubular sheet 2 may be 70% by weight or more, 90% by weight or more, 95% by weight or more, or 99% by weight or more. The tubular sheet 2 prepared in the preparation step (first step ST1) may be made of ePTFE. The tubular sheet 2 prepared in the preparation step (first step ST1) is preferably a sheet with PTFE exposed on its surface. Figure 13 In the example described, the outer peripheral surface of the tubular sheet 2 prepared in the preparation process (first step ST1) is exposed with polytetrafluoroethylene. In addition, the inner peripheral surface of the tubular sheet 2 prepared in the preparation process (first step ST1) is exposed with polytetrafluoroethylene.

[0074] The film thickness of the tubular sheet 2 prepared in the preparation process (first step ST1) is, for example, 0.01 mm or more and 2 mm or less. The film thickness of the tubular sheet 2 can be 0.05 mm or more and 1.5 mm or less, 0.1 mm or more and 1.0 mm or less, or 0.1 mm or more and 0.5 mm or less.

[0075] exist Figure 13 In the example described, the tubular sheet 2 prepared in the preparation step (first step ST1) is a seamless tubular body. The tubular sheet 2 prepared in the preparation step (first step ST1) can be a tubular body formed by extrusion molding.

[0076] like Figure 14 or Figure 15 As illustrated, in the second step ST2 (irradiation process), an ion beam BM is irradiated onto the polytetrafluoroethylene (PTFE) to form an ion implantation layer 30 on the cylindrical sheet 2. In the irradiation process (second step ST2), the ion beam BM irradiating the PTFE can contain argon ions, neon ions, or other ions. In other words, in the irradiation process (second step ST2), the element implanted into the PTFE can be argon, neon, or other elements.

[0077] like Figure 14 As illustrated, the irradiation process (second step ST2) may include irradiating the inner surface of the cylindrical sheet 2 with an ion beam BM to roughen the inner surface 2n of the cylindrical sheet 2.

[0078] exist Figure 14 In the described example, the angle α between the direction parallel to the length of the tubular sheet 2 and the direction in which the ion beam BM is incident on the polytetrafluoroethylene is 45 degrees or more and 90 degrees or less. This angle α is preferably 60 degrees or more, 70 degrees or more, 80 degrees or more, or 85 degrees or more. With an angle α of 45 degrees or more, the topological structure of the roughened surface 31r becomes favorable. In contrast, in the method described in Patent Document 2, the angle between the direction parallel to the length of the tube and the direction of travel of the ion beam BM is 1.7 degrees, preventing the ions from penetrating deep into the inner layer of the tube. In other words, in the method described in Patent Document 2, a roughened surface that is sufficiently beneficial to blood flow is not formed. Furthermore, in the method described in Patent Document 2, the asymmetry of the topological structure of the roughened surface becomes excessive, potentially restricting the installation direction of the tube relative to the blood vessel.

[0079] like Figure 15 As illustrated, the irradiation process (second step ST2) may include irradiating the outer surface 2t of the cylindrical sheet 2 with an ion beam BM to roughen the outer surface 2t of the cylindrical sheet 2. In other words, the process of irradiating polytetrafluoroethylene with an ion beam BM may include irradiating the outer surface 2t of the cylindrical sheet 2 with an ion beam BM.

[0080] exist Figure 15 In the described example, the angle α between the direction parallel to the length of the cylindrical sheet 2 and the direction in which the ion beam BM is incident on the polytetrafluoroethylene is 45 degrees or more and 90 degrees or less. This angle α is preferably 60 degrees or more, 70 degrees or more, 80 degrees or more, or 85 degrees or more. With an angle α of 45 degrees or more, the topological structure of the roughened surface 31r becomes better.

[0081] The irradiation process (second step ST2) can be performed while the cylindrical sheet 2 is rotating around the first axis AX1. In other words, the ion irradiation device 8b can irradiate the outer surface 2t of the cylindrical sheet 2 rotating around the first axis AX1 with an ion beam BM. Alternatively, during the execution of the irradiation process (second step ST2), the ion irradiation unit of the ion irradiation device 8b can rotate around the first axis AX1.

[0082] By performing an irradiation process (second step ST2), an ion-implanted layer 30 (more specifically, a layer in which the ion-implanted elements are mixed in polytetrafluoroethylene) is formed on the cylindrical sheet 2. After performing the irradiation process (second step ST2), a layer containing agent K can be attached to the surface of the ion-implanted layer 30. Regarding agent K, it has already been described in the first embodiment, so a repeated description of agent K is omitted.

[0083] like Figure 16 and Figure 17 As illustrated, in the third step ST3, the cylindrical sheet 2 can be flipped. The third step ST3 is a flipping process. In the flipping process (third step ST3), the cylindrical sheet 2 is flipped so that the outer surface 2t of the cylindrical sheet 2 becomes the inner surface. Through the process of flipping the cylindrical sheet, the outer surface 2t of the cylindrical sheet 2, which has been irradiated by the ion beam, becomes the inner surface of the cylindrical sheet 2.

[0084] exist Figure 16 and Figure 17 In the described example, by flipping the cylindrical sheet, the ion implantation layer 30 becomes the inner layer of the cylindrical sheet 2. Furthermore, the inner peripheral surface 31 of the ion implantation layer 30 becomes the roughened surface 31r. The ion implantation layer 30, the inner peripheral surface 31, and the roughened surface 31r have already been described in the first embodiment, therefore, repeated descriptions of the ion implantation layer 30, the inner peripheral surface 31, and the roughened surface 31r are omitted.

[0085] When the manufacturing method of the artificial blood vessel 1 includes the above-mentioned flipping process (third step ST3), the technical difficulty of irradiating the inner surface of the cylindrical sheet 2 with the ion beam BM can be avoided. Therefore, the above-mentioned irradiation process (second step ST2) can be performed using a more general ion irradiation device.

[0086] like Figure 18 As illustrated, in the fourth step ST4, an ion beam BM2 can be irradiated onto the outer peripheral surface 41 of the cylindrical sheet 2. The fourth step ST4 is the second irradiation process. The second irradiation process (fourth step ST4) includes irradiating the outer peripheral surface 41 of the cylindrical sheet 2 with the ion beam BM2 to form a second ion implantation layer 40 on the cylindrical sheet 2. By irradiating the outer peripheral surface 41 of the cylindrical sheet 2 with the ion beam BM2, at least a portion of the outer peripheral surface 41 of the cylindrical sheet 2 becomes a second roughened surface 41r (see, if necessary, reference...). Figure 8 or Figure 10 The second roughened surface 41r is formed by the surface of the second ion implantation layer 40.

[0087] In the second irradiation step (fourth step ST4), the ion beam BM2 irradiating the outer peripheral surface 41 of the cylindrical sheet 2 can contain argon ions, neon ions, or other ions. In other words, in the second irradiation step (fourth step ST4), the element implanted into the cylindrical sheet 2 (more specifically, the element ion implanted into the polytetrafluoroethylene) can be argon, neon, or other elements.

[0088] The second irradiation process (fourth step ST4) may include irradiating the outer peripheral surface 41 of the cylindrical sheet 2 with an ion beam BM2.

[0089] As an alternative, such as Figure 19 As illustrated, the second irradiation step (fourth step ST4) may include irradiating only a portion of the outer peripheral surface 41 of the cylindrical sheet 2 with the ion beam BM2. Figure 19 In the described example, the second irradiation step (fourth step ST4) includes irradiating a first region RG1 of the outer peripheral surface 41 of the cylindrical sheet 2 with an ion beam BM2. Figure 19 In the example described, the second irradiation process (fourth step ST4) is performed with a mask MK disposed in the region opposite to the second region RG2, so that the ion beam BM2 does not reach the second region RG2 on the outer peripheral surface 41 of the cylindrical sheet 2.

[0090] exist Figure 19 In the example described, after the second irradiation process (fourth step ST4) is performed, the outer peripheral surface 411 of the first end 21 of the cylindrical sheet 2 becomes a roughened surface 411r (more specifically, the surface of the second ion implantation layer 40).

[0091] exist Figure 19 In the example described, after the second irradiation process (fourth step ST4) is performed, the outer peripheral surface 413 of the second end 23 of the cylindrical sheet 2 becomes a roughened surface 413r (more specifically, the surface of the second ion implantation layer 40).

[0092] exist Figure 19 In the example described, after performing the second irradiation process (fourth step ST4), the outer peripheral surface 415 of the central region 25 along the length of the cylindrical sheet 2 is an unroughened surface. In other words, after performing the second irradiation process (fourth step ST4), the outer peripheral surface 415 of the central region 25 along the length of the cylindrical sheet 2 remains in an unroughened state.

[0093] exist Figure 18 (or Figure 19In the example described, the second irradiation step (fourth step ST4) can be performed while the cylindrical sheet 2 is rotating about the second axis AX2. In other words, the ion irradiation device 8b can irradiate the outer peripheral surface 41 of the cylindrical sheet 2 rotating about the second axis AX2 with an ion beam BM2. Alternatively, during the execution of the second irradiation step (fourth step ST4), the ion irradiation unit of the ion irradiation device 8b can rotate about the second axis AX2. The second axis AX2 may be the same as or different from the first axis AX1.

[0094] In execution Figure 14 After the illustrated irradiation procedure (second step ST2), the following can be performed. Figure 18 or Figure 19 The illustrated second irradiation procedure (fourth step ST4). During execution Figure 14 Before the illustrated irradiation procedure (second step ST2), it can be performed Figure 18 or Figure 19 The illustrated second irradiation procedure (fourth step ST4). Further, as an alternative, in performing... Figure 16 After the illustrated flipping process (step ST3), the following can be performed. Figure 18 or Figure 19 The second irradiation process (step 4 ST4) is illustrated.

[0095] like Figure 20 As illustrated, after performing the second irradiation step (fourth step ST4), a bio-adhesive J can be applied to the surface of the second ion implantation layer 40. As an alternative or additional solution, such as... Figure 21 As illustrated, after performing the second irradiation step (fourth step ST4), a blood leakage-preventing coating CT (e.g., a layer of biocompatible polymeric material to prevent blood leakage) can be applied to the surface of the second ion implantation layer 40. The coating CT (more specifically, the layer of biocompatible polymeric material) comprises, for example, a gel-like polymer (more specifically, biopolymers such as collagen and / or biocompatible polymers such as polyethylene glycol). Figure 21 In the described example, a coating CT (e.g., a coating CT containing collagen or a coating CT containing polyethylene glycol) is attached to the surface of the second ion implantation layer 40 (more specifically, the surface of the second ion implantation layer 40 with polytetrafluoroethylene as the main component), so that the surface of the second ion implantation layer 40, i.e. the second roughened surface 41r, has good adhesion to the coating CT.

[0096] The application of a coating CT (e.g., a collagen-containing coating CT or a polyethylene glycol-containing coating CT) to the surface of the second ion implantation layer 40 (more specifically, the surface of the second ion implantation layer 40 with polytetrafluoroethylene as the main component) can also be employed in the artificial blood vessel 1A of the first embodiment described above. In the first embodiment, the ion implantation layer 30 is, for example, non-gelatinous. In the first embodiment, a gelatinous coating (e.g., a collagen-containing gelatinous coating or a polyethylene glycol-containing gelatinous coating) can be applied to the surface of the ion implantation layer 30 (more specifically, the surface of the non-gelatinous ion implantation layer 30). Additionally, in the first embodiment, the second ion implantation layer 40 is, for example, non-gelatinous. In the first embodiment, a gelatinous coating (e.g., a collagen-containing gelatinous coating or a polyethylene glycol-containing gelatinous coating) can be applied to the surface of the second ion implantation layer 40 (more specifically, the surface of the non-gelatinous second ion implantation layer 40).

[0097] It should be noted that, in order to improve the adhesion between the substrate of the sheet applied to blood vessels and the biocompatible polymer material (e.g., collagen and / or polyethylene glycol) coated on the substrate, the technique of coating the surface of the ion-implanted layer of the substrate (e.g., a substrate with polytetrafluoroethylene as the main component) with a biocompatible polymer material (e.g., a gel-like biocompatible polymer material, a gel-like polymer material containing collagen, or a gel-like polymer material containing polyethylene glycol) can also be adopted in vascular patches. In this case, the vascular patch applied to blood vessels has, for example, the following configuration. (1) The vascular patch comprises a sheet covering the damaged portion of the vascular wall (e.g., a pore in the vascular wall); (2) the sheet comprises an ion-implanted layer (e.g., a non-gel-like layer); (3) the main component of the ion-implanted layer is polytetrafluoroethylene (PTFE); (4) the surface of the ion-implanted layer is formed by a roughened surface with PTFE as the main component; (5) a coating of a biocompatible polymer material in contact with the vascular wall (e.g., a gel-like polymer coating, more specifically, a coating comprising collagen and / or polyethylene glycol) is attached to the surface of the ion-implanted layer. The biocompatible polymer coating (e.g., a gel-like polymer coating) may be configured to contact the blood flow (in other words, the blood flowing in the vascular vessel) through the damaged portion of the vascular wall (e.g., a pore in the vascular wall). Since the adhesion between polytetrafluoroethylene (PTFE) and biocompatible polymers (e.g., collagen and / or polyethylene glycol) is improved by the roughening of the surface of the ion-implanted layer, the peeling of the biocompatible polymers from PTFE in contact with the bloodstream can be suppressed. It should be noted that the biocompatible polymers can dissolve into the bloodstream (dissolution is different from peeling). Furthermore, the biocompatible polymers can be biodegradable. This coating is applied after ion implantation of the PTFE. In other words, the coating is applied to the surface of the ion-implanted layer after the ion-implanted layer is formed on the sheet. The ion-implanted layer and the roughened surface have already been described in the first embodiment, therefore, a repetition of the description regarding the ion-implanted layer and the roughened surface is omitted.

[0098] like Figure 22 As illustrated, the method for manufacturing the artificial blood vessel 1 in the second embodiment may include a step of irradiating an ion beam BM3 onto the end face 21e of the cylindrical sheet 2 in the first direction DR1. By irradiating the end face 21e of the cylindrical sheet 2 in the first direction DR1 with the ion beam BM3, the end face 21e of the cylindrical sheet 2 in the first direction DR1 becomes a third roughened surface 21r. The third roughened surface 21r is formed by the surface of the third ion implantation layer 20.

[0099] like Figure 23As illustrated, the method for manufacturing the artificial blood vessel 1 in the second embodiment may include a step of irradiating the end face 23e of the cylindrical sheet 2 on the second direction DR2 side with an ion beam BM4. By irradiating the end face 23e of the cylindrical sheet 2 on the second direction DR2 side with an ion beam BM4, the end face 23e of the cylindrical sheet 2 on the second direction DR2 side becomes a fourth roughened surface 23r.

[0100] (Other implementation methods) In the first embodiment (except for the description column of "(pharmaceutical)"), the terms "blood", "first blood vessel", "second blood vessel" and "artificial blood vessel" can be replaced and understood as "body fluid", "first tubular tissue", "second tubular tissue" and "tubular prosthesis", respectively.

[0101] For example, other implementations involve tubular prostheses as shown below.

[0102] (1) A tubular prosthesis having a cylindrical sheet that defines a space for the flow of bodily fluids. The cylindrical sheet contains the ion-implanted layer as an inner layer. The main component of the ion implantation layer is polytetrafluoroethylene. The inner peripheral surface of the ion implantation layer is composed of a roughened surface with polytetrafluoroethylene as the main component. (2) According to the tubular prosthesis described in (1) above, wherein, The ion-implanted layer consists of a single layer in which elements implanted by ion implantation are mixed and present in the polytetrafluoroethylene. (3) The tubular prosthesis according to (1) or (2) above, wherein, At least a portion of the roughened surface, which is mainly composed of polytetrafluoroethylene, is exposed to the space in which the body fluid flows. (4) The tubular prosthesis according to any one of (1) to (3) above, wherein, The tubular sheet is a seamless structure. (5) The tubular prosthesis according to any one of (1) to (4) above, wherein, At least a portion of the outer peripheral surface of the tubular sheet is a second roughened surface. (6) The tubular prosthesis according to (5) above, wherein, At least a portion of the outer peripheral surface of the tubular sheet is an unroughened surface. (7) The tubular prosthesis according to any one of (1) to (6) above, wherein, When the direction from the second end of the tubular sheet toward the first end of the tubular sheet is defined as the first direction, the end face of the tubular sheet on the first direction side is the third roughened surface.

[0103] In the first embodiment, the terms "blood," "first blood vessel," "second blood vessel," and "artificial blood vessel" can be replaced with "lymph," "first tubular tissue," "second tubular tissue," and "artificial lymphatic vessel," respectively. In the first embodiment, the terms "blood," "first blood vessel," "second blood vessel," and "artificial blood vessel" can be replaced with "digestive fluid," "first tubular tissue," "second tubular tissue," and "artificial digestive tract," respectively. In the first embodiment, the terms "blood," "first blood vessel," "second blood vessel," and "artificial blood vessel" can be replaced with "urine," "first tubular tissue," "second tubular tissue," and "artificial ureter," respectively.

[0104] In the second embodiment, the terms "blood" and "artificial blood vessel" can be replaced with "body fluid" and "tubular prosthesis," respectively.

[0105] For example, other embodiments involve a method of manufacturing a tubular prosthesis as shown below.

[0106] (1) A method for manufacturing a tubular prosthesis, wherein the manufacturing method comprises: The process of preparing tubular sheets containing polytetrafluoroethylene; and The process of irradiating the polytetrafluoroethylene with an ion beam to form an ion implantation layer on the tubular sheet. The cylindrical sheet contains the ion-implanted layer as an inner layer. The main component of the ion implantation layer is polytetrafluoroethylene. The inner peripheral surface of the ion implantation layer is composed of a roughened surface with polytetrafluoroethylene as the main component. (2) The method for manufacturing the tubular prosthesis according to (1) above, wherein, The angle between the direction parallel to the length of the tubular sheet and the direction in which the ion beam is incident on the polytetrafluoroethylene is 45 degrees or more. (3) The method for manufacturing the tubular prosthesis according to (1) or (2) above, wherein, The manufacturing method includes a step of flipping the cylindrical sheet so that the outer surface of the cylindrical sheet becomes the inner surface. The process of irradiating the polytetrafluoroethylene with the ion beam includes irradiating the outer surface of the tubular sheet with the ion beam. In the process of flipping the tubular sheet, the outer surface that was irradiated by the ion beam becomes the inner surface. (4) The method for manufacturing a tubular prosthesis according to any one of (1) to (3) above, wherein, The manufacturing method includes a step of irradiating the outer peripheral surface of the cylindrical sheet with an ion beam to form a second ion implantation layer on the cylindrical sheet. After performing the step of irradiating the outer peripheral surface of the tubular sheet with the ion beam, a bio-adhesive is applied to the surface of the second ion implantation layer.

[0107] In the second embodiment, the terms "blood" and "artificial blood vessel" can be replaced with "lymph" and "artificial lymphatic vessel," respectively. In the second embodiment, the terms "blood" and "artificial blood vessel" can be replaced with "digestive fluid" and "artificial digestive tract," respectively. In the second embodiment, the terms "blood" and "artificial blood vessel" can be replaced with "urine" and "artificial ureter," respectively.

[0108] This invention is not limited to the above-described embodiments or modifications. It is evident that appropriate modifications or alterations can be made to the embodiments or modifications within the scope of the technical concept of this invention. Furthermore, various techniques used in the embodiments or modifications can be applied to other embodiments or modifications as long as they do not create technical contradictions. Further, any additional structures in the embodiments or modifications can be appropriately omitted. Explanation of reference numerals in the attached figures

[0109] 1, 1A: Artificial blood vessel; 2: Cylindrical sheet; 2n: Inner surface; 2t: Outer surface; 8a, 8b: Ion irradiation device; 9: Blood vessel; 9a: First blood vessel; 9b: Second blood vessel; 20: Ion implantation layer; 21: First end; 21c: First contact layer; 21e: End face; 21r: Roughened surface; 23: Second end; 23c: Second contact layer; 23e: End face; 23r: Roughened surface; 25: Central region in the length direction; 30: Ion implantation layer; 30d: Recess; 31: Inner peripheral surface; 31r: Roughened surface; 40: Ion implantation layer; 41: Outer peripheral surface; 41r: Roughened surface; 41s: Unroughened surface; 81 : Superconducting magnet; 90: Tissue; 311: Inner peripheral surface; 311r: Roughened surface; 411: Outer peripheral surface; 411r: Roughened surface; 413: Outer peripheral surface; 413r: Roughened surface; 415: Outer peripheral surface; 415r: Roughened surface; AX1: First axis; AX2: Second axis; BM, BM2, BM3, BM4: Ion beam; CT: Coating; DR1: First direction; DR2: Second direction; J: Bioadhesive; K: Agent; K1: Blood coagulation inhibitor; K2: Agent regulating the spread of vascular endothelial cells; MK: Mask; PT: In vivo tissue; RG1: First region; RG2: Second region; SP: Space.

Claims

1. An artificial blood vessel, wherein, The artificial blood vessel has a cylindrical sheet that defines a space for blood flow. The cylindrical sheet contains the ion-implanted layer as an inner layer. The main component of the ion implantation layer is polytetrafluoroethylene. The inner peripheral surface of the ion implantation layer is composed of a roughened surface with polytetrafluoroethylene as the main component.

2. The artificial blood vessel according to claim 1, wherein, The ion-implanted layer consists of a single layer in which elements implanted by ion implantation are mixed and present in the polytetrafluoroethylene.

3. The artificial blood vessel according to claim 1, wherein, At least a portion of the roughened surface, which is mainly composed of polytetrafluoroethylene, is exposed to the space in which the blood flows.

4. The artificial blood vessel according to any one of claims 1 to 3, wherein, The tubular sheet is a seamless structure.

5. The artificial blood vessel according to any one of claims 1 to 3, wherein, At least a portion of the outer peripheral surface of the tubular sheet is a second roughened surface.

6. The artificial blood vessel according to claim 5, wherein, At least a portion of the outer peripheral surface of the tubular sheet is an unroughened surface.

7. The artificial blood vessel according to any one of claims 1 to 3, wherein, The inner peripheral surface of the ion implantation layer carries a drug.

8. The artificial blood vessel according to claim 7, wherein, The drug contains a blood clotting inhibitor.

9. A method for manufacturing an artificial blood vessel, wherein, The manufacturing method comprises: The process of preparing tubular sheets containing polytetrafluoroethylene; and The process of irradiating the polytetrafluoroethylene with an ion beam to form an ion implantation layer on the tubular sheet. The cylindrical sheet contains the ion-implanted layer as an inner layer. The main component of the ion implantation layer is polytetrafluoroethylene. The inner peripheral surface of the ion implantation layer is composed of a roughened surface with polytetrafluoroethylene as the main component.

10. The method for manufacturing an artificial blood vessel according to claim 9, wherein, The angle between the direction parallel to the length of the tubular sheet and the direction in which the ion beam is incident on the polytetrafluoroethylene is 45 degrees or more.

11. The method for manufacturing an artificial blood vessel according to claim 9 or 10, wherein, The manufacturing method includes a step of flipping the cylindrical sheet so that the outer surface of the cylindrical sheet becomes the inner surface. The process of irradiating the polytetrafluoroethylene with the ion beam includes irradiating the outer surface of the tubular sheet with the ion beam. In the process of flipping the tubular sheet, the outer surface that was irradiated by the ion beam becomes the inner surface.

12. The method for manufacturing an artificial blood vessel according to claim 9 or 10, wherein, After performing the step of irradiating the polytetrafluoroethylene with the ion beam, a layer containing a reagent is attached to the surface of the ion implantation layer.

13. The method for manufacturing an artificial blood vessel according to claim 9 or 10, wherein, The manufacturing method includes a step of irradiating the outer peripheral surface of the cylindrical sheet with an ion beam to form a second ion implantation layer on the cylindrical sheet. After performing the step of irradiating the outer peripheral surface of the tubular sheet with the ion beam, at least one of a bio-adhesive and a coating to prevent blood leakage is applied to the surface of the second ion implantation layer.

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