Artificial blood vessel, and method for manufacturing an artificial blood vessel

Abstract

The present invention provides an artificial blood vessel having an inner surface that appropriately acts on blood flow, and a method for manufacturing an artificial blood vessel having an inner surface that appropriately acts on blood flow. [Solution] The artificial blood vessel comprises a tubular sheet that defines the space through which blood flows. The tubular sheet includes an ion-implanted layer as an inner layer. The main component of the ion-implanted layer is polytetrafluoroethylene. The inner circumferential surface of the ion-implanted layer is composed of a roughened surface mainly made of polytetrafluoroethylene.

Description

Technical Field

[0001] The present invention relates to an artificial blood vessel and a method for manufacturing the artificial blood vessel.

Background Art

[0002] Patch materials constituting artificial blood vessels and the like are known.

[0003] As a related technique, Patent Document 1 discloses a biological repair material having an affinity with a biological tissue adhesive. Patent Document 1 describes irradiating polytetrafluoroethylene with an ion beam to improve the adhesiveness with fibrin glue.

[0004] Conventionally, irradiation of an ion beam to polytetrafluoroethylene has been performed solely to improve the adhesiveness with a tissue or fibrin glue. On the other hand, utilization of the ion-irradiated surface of polytetrafluoroethylene as a surface defining a lumen through which body fluid flows has not been performed and is not known heretofore. In particular, due to the physical difficulty of irradiating an ion beam to the inner peripheral surface of a cylindrical body, irradiation of an ion beam to the inner peripheral surface of an artificial blood vessel made of polytetrafluoroethylene has not been performed and is not known heretofore.

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

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

[0007] The object of the present invention is to provide an artificial blood vessel having an inner surface that acts suitably on blood flow, and a method for manufacturing an artificial blood vessel having an inner surface that acts suitably on blood flow. [Means for solving the problem]

[0008] Embodiments of the present invention relate to the following artificial blood vessels and methods for manufacturing artificial blood vessels.

[0009] (1) Equipped with a tubular sheet that defines the space through which blood flows, The tubular sheet includes an ion implantation layer as an inner layer, The main component of the ion implantation layer is polytetrafluoroethylene. The inner surface of the ion implantation layer is composed of a roughened surface mainly composed of polytetrafluoroethylene. Artificial blood vessel. (2) The ion implantation layer is composed of a single layer in which elements implanted by ion implantation are mixed with the polytetrafluoroethylene. The artificial blood vessel described in (1) above. (3) At least a portion of the roughened surface, which is mainly composed of polytetrafluoroethylene, is exposed to the space through which the blood flows. The artificial blood vessel described in (1) or (2) above. (4) The tubular sheet is seamless. An artificial blood vessel as described in any one of the above (1) to (3). (5) At least a portion of the outer surface of the cylindrical sheet is a second roughened surface. An artificial blood vessel as described in any one of the above (1) through (4). (6) At least a portion of the outer surface of the cylindrical sheet is a non-roughened surface. The artificial blood vessel described in (5) above. (7) The inner surface of the ion implantation layer is supported with a drug. An artificial blood vessel as described in any one of the above (1) through (6). (8) The drug includes an anticoagulant. The artificial blood vessel described in (7) above. (9) A step of preparing a tubular sheet containing polytetrafluoroethylene, The process involves irradiating the polytetrafluoroethylene with an ion beam so that an ion implantation layer is formed on the tubular sheet, It is equipped with, The tubular sheet includes the ion implantation layer as an inner layer, The main component of the ion implantation layer is the polytetrafluoroethylene, The inner surface of the ion implantation layer is composed of a roughened surface mainly composed of polytetrafluoroethylene. A method for manufacturing artificial blood vessels. (10) The angle between the direction parallel to the longitudinal direction of the tubular sheet and the direction in which the ion beam is incident on the polytetrafluoroethylene is 45 degrees or more. A method for manufacturing an artificial blood vessel as described in (9) above. (11) The process includes the step of inverting the cylindrical sheet so that the outer surface of the cylindrical sheet becomes the inner surface, The step of irradiating the polytetrafluoroethylene with the ion beam includes irradiating the outer surface of the cylindrical sheet with the ion beam. By inverting the cylindrical sheet, the outer surface irradiated with the ion beam becomes the inner surface. A method for manufacturing an artificial blood vessel as described in (9) or (10) above. (12) After the step of irradiating the polytetrafluoroethylene with the ion beam is performed, a layer containing the agent is added to the surface of the ion implantation layer. A method for manufacturing an artificial blood vessel as described in any one of (9) to (11) above. (13) The process includes irradiating the outer surface of the cylindrical sheet with an ion beam so that a second ion implantation layer is formed 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 bioadhesive and a coating for preventing blood leakage is added to the surface of the second ion implantation layer. The method for manufacturing an artificial blood vessel according to any one of (9) to (12) above.

Effect of the Invention

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

Brief Description of the Drawings

[0011] [Figure 1] FIG. 1 is a schematic perspective view schematically showing an artificial blood vessel in a first embodiment. [Figure 2] FIG. 2 is a schematic cross-sectional view schematically showing an artificial blood vessel in a first embodiment. [Figure 3] FIG. 3 is a schematic cross-sectional view schematically showing a state where the artificial blood vessel in the first embodiment is attached to the first blood vessel and the second blood vessel. [Figure 4] FIG. 4 is a schematic cross-sectional view schematically showing a state where a patient's tissue has advanced on the inner peripheral surface of the ion implantation layer. [Figure 5] FIG. 5 is a schematic cross-sectional view schematically showing a state where the inner peripheral surface of the end portion of the artificial blood vessel in the first embodiment is attached to the outer peripheral surface of the end portion of a patient's blood vessel. [Figure 6] FIG. 6 is a schematic cross-sectional view schematically showing a state where the artificial blood vessel is attached to a patient's blood vessel with the end face of the artificial blood vessel in the first embodiment in contact with the end face of the patient's blood vessel. [Figure 7] FIG. 7 is a schematic perspective view schematically showing an artificial blood vessel in a first modification of the first embodiment. [Figure 8] FIG. 8 is a schematic cross-sectional view schematically showing a state where the artificial blood vessel in the first modification of the first embodiment is attached to the first blood vessel and the second blood vessel. [Figure 9]Figure 9 is a schematic perspective view showing an artificial blood vessel in a second modified example of the first embodiment. [Figure 10] Figure 10 is a schematic cross-sectional view illustrating the state in which the artificial blood vessel in the second modified example of the first embodiment is attached to the first and second blood vessels. [Figure 11] Figure 11 is a schematic cross-sectional view illustrating the state in which the artificial blood vessel in the first embodiment is carrying the drug. [Figure 12] Figure 12 is a schematic cross-sectional view illustrating a modified example of the first embodiment in which an artificial blood vessel is carrying a drug. [Figure 13] Figure 13 is a schematic perspective view illustrating an example of a tubular sheet prepared in the preparation process. [Figure 14] Figure 14 is a schematic cross-sectional view illustrating how an ion beam is irradiated onto the inner surface of a cylindrical sheet from an ion irradiation device. [Figure 15] Figure 15 is a schematic cross-sectional view illustrating how an ion beam is irradiated onto the outer surface of a cylindrical sheet from an ion irradiation device. [Figure 16] Figure 16 schematically shows how the cylindrical sheet is inverted. [Figure 17] Figure 17 is a schematic perspective view illustrating the state during the inversion process. [Figure 18] Figure 18 is a schematic cross-sectional view illustrating the state during the second irradiation process. [Figure 19] Figure 19 is a schematic cross-sectional view illustrating how an ion beam is irradiated only to a portion of the outer surface of a cylindrical sheet. [Figure 20] Figure 20 is a schematic cross-sectional view illustrating the state after the second irradiation process, where the bio-adhesive has been applied to the surface of the second ion-implanted layer. [Figure 21] Figure 21 is a schematic cross-sectional view illustrating the state after the second irradiation process, where a coating to prevent blood leakage has been applied to the surface of the second ion implantation layer. [Figure 22]Figure 22 is a schematic cross-sectional view illustrating how an ion beam is irradiated onto the end face of a cylindrical sheet on the first direction side. [Figure 23] Figure 23 is a schematic cross-sectional view illustrating how an ion beam is irradiated onto the end face of a cylindrical sheet in the second direction. [Figure 24] Figure 24 is a flowchart showing an example of a method for manufacturing an artificial blood vessel in the second embodiment. [Modes for carrying out the invention]

[0012] The artificial blood vessel 1A and the method for manufacturing the artificial blood vessel 1 in the embodiment will be described below with reference to the drawings. In the following description, the same reference numerals are used for members and parts having the same function, and repeated descriptions of members and parts with the same reference numerals will be omitted.

[0013] (Definition of terms) 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. The direction opposite to the first direction DR1 is defined as the second direction DR2. In the example shown in Figure 1, both the first direction DR1 and the second direction DR2 coincide with the longitudinal direction of the tubular sheet 2.

[0014] (First embodiment) The artificial blood vessel 1A in the first embodiment will be described with reference to Figures 1 to 12. Figure 1 is a schematic perspective view showing the artificial blood vessel 1A in the first embodiment. Figure 2 is a schematic cross-sectional view showing the artificial blood vessel 1A in the first embodiment. Figure 3 is a schematic cross-sectional view showing the artificial blood vessel 1A in the first embodiment attached to the first blood vessel 9a and the second blood vessel 9b. Figure 4 is a schematic cross-sectional view showing the state in which the patient's tissue 90 has grown onto the inner circumferential surface 31 of the ion implantation layer 30. Figure 5 is a schematic cross-sectional view showing the state in which the inner circumferential surface of the end of the artificial blood vessel 1A in the first embodiment is attached to the outer circumferential surface of the end of the patient's blood vessel 9. Figure 6 is a schematic cross-sectional view showing the state in which the artificial blood vessel 1A is attached to 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. Figure 7 is a schematic perspective view showing the artificial blood vessel 1A in a first modified example of the first embodiment. Figure 8 is a schematic cross-sectional view showing the artificial blood vessel 1A in the first modified example of the first embodiment attached to the first blood vessel 9a and the second blood vessel 9b. Figure 9 is a schematic perspective view showing the artificial blood vessel 1A in the second modified example of the first embodiment. Figure 10 is a schematic cross-sectional view showing the artificial blood vessel 1A in the second modified example of the first embodiment attached to the first blood vessel 9a and the second blood vessel 9b. Figure 11 is a schematic cross-sectional view showing the artificial blood vessel 1A in the first embodiment carrying the drug K. Figure 12 is a schematic cross-sectional view showing the artificial blood vessel 1A in the modified example of the first embodiment carrying the drug K.

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

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

[0017] In the example shown in Figure 2, the inner circumferential surface 31 of the ion implantation layer 30 is composed of a roughened surface 31r mainly made of polytetrafluoroethylene. In other words, the proportion of polytetrafluoroethylene constituting the roughened surface to the total material constituting the roughened surface 31r is 50 weight percent or more. The proportion of polytetrafluoroethylene constituting the roughened surface to the total material constituting the roughened surface 31r may be 70 weight percent or more, 90 weight percent or more, 95 weight percent or more, or 99 weight percent or more.

[0018] The entire tubular sheet 2 may contain polytetrafluoroethylene as its main component. In other words, the proportion of polytetrafluoroethylene in the total material constituting the tubular sheet 2 may be 50 weight percent or more. The proportion of polytetrafluoroethylene constituting the tubular sheet 2 in the total material constituting the tubular sheet 2 may be 70 weight percent or more, 90 weight percent or more, 95 weight percent or more, or 99 weight percent or more. Alternatively, the tubular sheet 2 may be a laminate of an inner layer made of polytetrafluoroethylene and an outer layer made of other material.

[0019] In the example shown in Figure 2, the roughened surface 31r is formed by the inner circumferential surface 31 of the ion-implanted layer 30. In this specification, "ion-implanted layer 30" means a layer whose physical and / or chemical properties have been modified by the implantation of ionized elements. In the example shown in Figure 2, the ion-implanted layer 30 has a plurality of fine depressions 30d on its surface due to ion implantation.

[0020] The roughened surface 31r, mainly composed of polytetrafluoroethylene (more specifically, the inner circumferential surface 31 of the ion implantation layer 30), acts favorably on blood flow. More specifically, the roughened surface 31r, mainly composed of polytetrafluoroethylene (more specifically, the inner circumferential surface 31 of the ion implantation layer 30), reduces frictional resistance between the inner surface of the tubular sheet 2 and the blood flowing inside the tubular sheet 2, similar to a riblet. In this way, the blood flow FL of patients to whom the artificial blood vessel 1A is applied is improved (see Figure 3). The degree of roughening of the roughened surface 31r may be set so that the Reynolds number of the blood flowing inside the tubular sheet 2 becomes an appropriate value. For example, the degree of roughening of the roughened surface 31r may be set so that the blood flow near the inner circumferential surface 31 becomes laminar flow.

[0021] The roughened surface 31r, which is mainly composed of polytetrafluoroethylene, allows patient cells to grow more easily compared to the non-roughened surface. Therefore, as illustrated in Figure 4, after the artificial blood vessel 1A is anastomosed to the patient's blood vessel 9, the roughened surface 31r of the tubular sheet 2 is covered relatively quickly 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, the tubular sheet 2 is expected to act on blood flow, just like the patient's blood vessel 9.

[0022] (Optional additional configuration) Next, we will describe optional additional configurations that can be adopted in the artificial blood vessel 1A in the first embodiment.

[0023] (Extended polytetrafluoroethylene) In this specification, polytetrafluoroethylene is preferably stretched polytetrafluoroethylene (hereinafter referred to as "ePTEF"). ePTEF is stretched polytetrafluoroethylene (more specifically, polytetrafluoroethylene stretched under heating conditions). ePTEF is stretched porous polytetrafluoroethylene produced, for example, by the method described in U.S. Patent No. 3,953,566 or No. 4,187,390. Alternatively, polytetrafluoroethylene in this specification may be unstretched polytetrafluoroethylene.

[0024] (Ion implantation layer 30) The ion-implanted layer 30 is a layer in which the ion-implanted elements are mixed with polytetrafluoroethylene. Some of the ion-implanted elements may escape from the ion-implanted layer 30. The elements ion-implanted into the polytetrafluoroethylene may be argon, neon, or other elements. In other words, the ion-implanted layer 30 may be a layer in which argon is mixed with polytetrafluoroethylene, a layer in which neon is mixed with polytetrafluoroethylene, or a layer in which other elements are mixed with polytetrafluoroethylene.

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

[0026] As illustrated in Figure 2, at least a portion of the roughened surface 31r, which is mainly composed of polytetrafluoroethylene, is exposed to the space SP through which blood flows. Substantially the entire roughened surface 31r, which is mainly composed of polytetrafluoroethylene, may be exposed to the space SP through which blood flows. The roughened surface 31r acts favorably on blood flow. Furthermore, compared to a non-roughened surface, the roughened surface 31r facilitates the growth of patient cells (more specifically, endothelial cells).

[0027] The entire inner surface of the tubular sheet 2 may be a roughened 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 as a whole contributes to reducing frictional resistance to blood flow. In addition, the patient's tissue 90 (more specifically, the patient's endothelial cells) can easily spread across the entire inner circumferential surface 31 of the ion implantation layer 30.

[0028] The maximum height roughness Rz of the inner surface 31 of the ion implantation layer 30 is, for example, 8 μm or more. In this specification, "maximum height roughness Rz" is measured in accordance with JIS B 0601:2013 (corresponding international standard ISO 4287:1997, Amd.1:2009).

[0029] (Seamless tubular sheet 2) The tubular sheet 2 is preferably seamless. In this case, the inner surface of the tubular sheet 2 is seamless, which allows for smoother blood flow. In the example shown in Figure 1, the tubular sheet 2 is a seamless tubular sheet.

[0030] The seamless tubular sheet 2 is formed, for example, by extrusion molding. More specifically, the seamless tubular sheet 2 is formed by extruding a raw material mainly composed of polytetrafluoroethylene into a tubular shape. In contrast, when the tubular sheet 2 is formed by rolling up a flat sheet, the presence of seams is unavoidable.

[0031] After the tubular sheet 2 is formed, the outer surface of the tubular sheet 2 may be roughened by ion irradiation. After the outer surface of the tubular sheet 2 is roughened, the tubular sheet 2 may be inverted so that the outer surface becomes the inner surface. This inversion makes the inner surface of the tubular sheet 2 the roughened surface 31r. This inversion overcomes the technical difficulty of making the inner layer of the tubular sheet 2 an ion implantation layer.

[0032] (Cylindrical sheet 2) The artificial blood vessel 1A in the first embodiment comprises a tubular sheet 2. More specifically, the artificial blood vessel 1A is composed of a tubular sheet 2. The thickness of the tubular sheet 2 is, for example, 0.01 mm or more and 2 mm or less. The thickness of the tubular sheet 2 may 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 tubular sheet 2) In the example shown in Figure 3, the tubular sheet 2 has a first end 21 that is attached to the patient's first blood vessel 9a. In the example shown in Figure 3, the first end 21 is attached to the end of the patient's first blood vessel 9a by an end-to-end joint. Alternatively, the first end 21 may be attached to the patient's first blood vessel 9a by an end-to-side joint. The first end 21 may be attached to the patient's first blood vessel 9a by a suture. Alternatively, or additionally, the first end 21 may be attached to the patient's first blood vessel 9a by a bioadhesive (e.g., fibrin glue). Any known method can be used to attach the first end 21 to the first blood vessel 9a.

[0034] The first contact layer 21c of the first end 21 that is in contact with the first blood vessel 9a preferably includes a roughened surface (more specifically, the surface of the ion implantation layer) (see Figures 7 and 8). In this case, patient cells can easily grow between the first contact layer 21c and the first blood vessel 9a. Therefore, blood is less likely to leak from between the first contact layer 21c and the first blood vessel 9a. A bioadhesive may 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 implantation layer), the roughened surface preferably supports the bioadhesive. The first contact layer 21c may also be a layer to which a coating is applied to the roughened surface (more specifically, the surface of the ion implantation layer) to prevent blood leakage.

[0035] As illustrated in Figure 3, the first end 21 of the tubular sheet 2 may be configured to be attached to the first vessel 9a with the end of the first vessel 9a inserted inside the end of the first vessel 9a. Alternatively, as illustrated in Figure 5, the first end 21 of the tubular sheet 2 may be configured to be attached to the first vessel 9a with the end of the first vessel 9a inserted inside the first end 21 of the tubular sheet 2.

[0036] Alternatively, as illustrated in Figure 6, the first end 21 of the tubular sheet 2 may be attached to the first blood vessel 9a such that the end face 21e of the first end 21 of the tubular sheet 2 is in contact with the end face of the end of the first blood vessel 9a.

[0037] In the example shown in Figure 6, the end face 21e of the first end 21 of the tubular sheet 2 (more specifically, the end face 21e on the first direction DR1 side of the tubular sheet 2) includes a roughened surface 21r. In the example shown in Figure 6, the roughened surface 21r is composed of the surface of the ion implantation layer 20. When the end face 21e includes the roughened surface 21r (more specifically, the surface of the ion implantation layer 20), the patient's cells rapidly grow onto 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 is prevented. In addition, from the viewpoint of preventing blood leakage from the gap before the patient's cells grow onto the roughened surface 21r (more specifically, the surface of the ion implantation layer 20), a bioadhesive may be applied to the roughened surface 21r.

[0038] As illustrated in Figure 4, 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 advances onto 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 is prevented, and blood flow near the end face 21e of the tubular sheet 2 on the first direction DR1 side is improved.

[0039] (Second end 23 of the tubular sheet 2) In the example shown in Figure 3, the tubular sheet 2 has a second end 23 that is attached to the patient's second blood vessel 9b. In the example shown in Figure 3, the second end 23 is attached to the end of the patient's second blood vessel 9b by an end-to-end joint. Alternatively, the second end 23 may be attached to the patient's second blood vessel 9b by an end-to-side joint. The second end 23 may be attached to the patient's second blood vessel 9b by a suture. Alternatively, or additionally, the second end 23 may be attached to the patient's second blood vessel 9b by a bioadhesive (e.g., fibrin glue). Any known method can be used to attach the second end 23 to the second blood vessel 9b.

[0040] The second contact layer 23c of the second end 23 that is in contact with the second blood vessel 9b preferably includes a roughened surface (more specifically, the surface of the ion implantation layer) (see Figures 7 and 8). In this case, patient cells can easily spread between the second contact layer 23c and the second blood vessel 9b. Therefore, blood is less likely to leak from between the second contact layer 23c and the second blood vessel 9b. A bioadhesive may 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 implantation layer), the second contact layer 23c preferably supports the bioadhesive. The second contact layer 23c may also be a layer to which a coating is applied to the roughened surface (more specifically, the surface of the ion implantation layer) to prevent blood leakage.

[0041] As illustrated in Figure 3, the second end 23 of the tubular sheet 2 may be configured to be attached to the second vessel 9b with the end of the second vessel 9b inserted inside the end of the second vessel 9b. Alternatively, as illustrated in Figure 5, the second end 23 of the tubular sheet 2 may be configured to be attached to the second vessel 9b with the end of the second vessel 9b inserted inside the second end 23 of the tubular sheet 2.

[0042] Alternatively, as illustrated in Figure 6, the second end 23 of the tubular sheet 2 may be attached to the second blood vessel 9b such that the end face 23e of the second end 23 of the tubular sheet 2 is in contact with the end face of the end 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. This roughened surface 23r may be formed by the surface of the ion implantation layer.

[0044] (Outer surface 41 of the cylindrical sheet 2) As illustrated in Figure 1, the outer surface 41 of the cylindrical sheet 2 may be an unroughened surface 41s (more specifically, a smooth surface). In the example shown in Figure 1, substantially the entire outer surface 41 of the cylindrical sheet 2 is an unroughened surface 41s (more specifically, a smooth surface). In this specification, "unroughened surface" means a surface that has not been subjected to roughening treatment and has a maximum height roughness Rz smaller than that of the roughened surface 31r.

[0045] In the examples shown in Figures 1 and 7, at least a portion of the outer surface 41 of the tubular sheet 2 (for example, the outer surface 415 of the longitudinal central region 25 of the tubular sheet 2) is a non-roughened surface 41s. The non-roughened surface 41s is less likely to adhere to the patient's in vivo tissues.

[0046] In the examples shown in Figures 7 and 9, at least a portion of the outer surface 41 of the tubular sheet 2 is a roughened surface 41r. Preferably, the outer surface 41 of the tubular sheet 2 contains a roughened surface 41r mainly composed of polytetrafluoroethylene. The entire outer surface 41 of the tubular sheet 2 may also contain polytetrafluoroethylene as the main component.

[0047] As illustrated in Figures 8 and 10, the roughened surface 41r is composed of the surface of the ion-implanted layer 40. The ion-implanted layer 40 is, for example, a layer in which ion-implanted elements are mixed with polytetrafluoroethylene. The elements implanted into the tubular sheet 2 (more specifically, the elements ion-implanted into the polytetrafluoroethylene) are, for example, argon, neon, etc. The ion-implanted layer 40 may be a layer in which argon is mixed with polytetrafluoroethylene, or a layer in which neon is mixed with polytetrafluoroethylene.

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

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

[0050] If the outer circumferential 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), then after the outer circumferential surface 411 of the first end 21 is attached to the first blood vessel 9a, patient cells can easily grow between the outer circumferential surface 411 and the first blood vessel 9a. Therefore, blood is less likely to leak from between the outer circumferential surface 411 and the first blood vessel 9a. Alternatively, or additionally, as illustrated in Figure 5, the inner circumferential surface 311 of the first end 21 of the tubular sheet 2 may 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 attached to the first blood vessel 9a, patient cells can easily grow 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] As illustrated in Figure 10, the outer circumferential surface 415 of the longitudinal central region 25 of the tubular sheet 2 may be a roughened surface 415r (more specifically, the surface of the ion implantation layer 40). In this case, the outer circumferential surface 415 of the longitudinal central region 25 of the tubular sheet 2 may be fixed to the patient's in vivo tissue PT. This fixation may be performed by the patient's tissue (more specifically, the patient's cells) growing onto the roughened surface 415r through contact between the roughened surface 415r and the in vivo tissue PT. Alternatively, or additionally, this fixation may be performed using a bioadhesive or sutures.

[0052] As illustrated in Figure 9, substantially the entire outer surface 41 of the tubular sheet 2 may be a roughened surface 41r (more specifically, the surface of the ion implantation layer 40).

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

[0054] In this specification, in order to distinguish between the "ion implantation layer 30" on the inner surface of the tubular sheet 2 and the "ion implantation layer 40" on the outer surface of the tubular sheet 2, the latter will be referred to as the "second ion implantation layer 40". In this specification, in order to distinguish between the "ion implantation layer 30" on the inner surface of the tubular sheet 2 and the "ion implantation layer 20" on the end face 21e side of the first direction DR1 of the tubular sheet 2, the latter will be referred to as the "third ion implantation layer 20".

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

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

[0057] (Pharmacist K) As illustrated in Figures 11 and 12, the drug K may be supported on the inner circumferential surface 31 of the ion implantation layer 30. Multiple fine depressions 30d are formed on the inner circumferential surface 31 of the ion implantation layer 30 by ion implantation. These depressions 30d suitably support the drug K.

[0058] The inner surface 31 of the ion implantation layer 30 may have a drug that inhibits blood coagulation (hereinafter referred to as "anticoagulant K1"). In other words, the drug K carried on the inner surface 31 of the ion implantation layer 30 may include anticoagulants K1 (e.g., anticoagulants, antiplatelet agents). Since anticoagulants are well known, a description of anticoagulants will be omitted.

[0059] Alternatively, or additionally, the inner circumferential surface 31 of the ion implantation layer 30 may be supported with a drug K2 that modulates the growth of vascular endothelial cells. The drug K2 that modulates the growth of vascular endothelial cells may be a drug that stimulates the proliferation of vascular endothelial cells (for example, a drug containing vascular endothelial growth factor (VEGF)) or a cell proliferation inhibitor that suppresses the proliferation of vascular endothelial cells. The drug K2 that modulates the growth of vascular endothelial cells allows for suitable control of the time it takes for the inner surface of the tubular sheet 2 to be covered by the patient's tissue (more specifically, the patient's endothelial cells).

[0060] In the examples shown in Figures 11 and 12, a portion of the inner surface 31 of the ion implantation layer 30 is exposed to the blood-flow space SP without being covered by the drug K. Alternatively, the entire inner surface 31 of the ion implantation layer 30 may be covered by the drug K. In these cases, the drug K is released into the bloodstream, causing the inner surface 31 of the ion implantation layer 30 to be exposed to the blood-flow space SP. After the inner surface 31 of the ion implantation layer 30 is exposed to the blood-flow space SP, it contributes to reducing frictional resistance to blood flow. Furthermore, patient tissue 90 (more specifically, patient endothelial cells) grows onto the inner surface 31 of the ion implantation layer 30.

[0061] (Second embodiment) A method for manufacturing the artificial blood vessel 1 in the second embodiment will be described with reference to Figures 1 to 24. Figure 13 is a schematic perspective view showing an example of a tubular sheet 2 prepared in the preparation step. Figure 14 is a schematic cross-sectional view showing the ion beam BM being irradiated onto the inner surface of the tubular sheet 2 from the ion irradiation device 8a. Figure 15 is a schematic cross-sectional view showing the ion beam BM being irradiated onto the outer surface 2t of the tubular sheet 2 from the ion irradiation device 8b. Figure 16 is a schematic diagram showing the tubular sheet 2 being inverted. Figure 17 is a schematic perspective view showing the state during the inversion step. Figure 18 is a schematic cross-sectional view showing the state during the second irradiation step. Figure 19 is a schematic cross-sectional view showing the ion beam BM2 being irradiated only onto a part of the outer peripheral surface 41 of the tubular sheet 2. Figure 20 is a schematic cross-sectional view showing the state after the second irradiation step, with the bio-adhesive J added to the surface of the second ion implantation layer 40. Figure 21 is a schematic cross-sectional view showing the state after the second irradiation step, where a coating CT to prevent blood leakage has been added to the surface of the second ion implantation layer 40. Figure 22 is a schematic cross-sectional view showing the ion beam BM3 being irradiated onto the end face 21e on the first direction DR1 side of the tubular sheet 2. Figure 23 is a schematic cross-sectional view showing the ion beam BM4 being irradiated onto the end face 23e on the second direction DR2 side of the tubular sheet 2. Figure 24 is a flowchart showing an example of a method for manufacturing the artificial blood vessel 1 in the second embodiment.

[0062] The second embodiment will primarily describe the differences from the first embodiment. On the other hand, the second embodiment will omit repetitive explanations of matters already described in the first embodiment. Therefore, it goes without saying that even if not explicitly explained in the second embodiment, matters already described in the first embodiment can be applied to the second embodiment. Conversely, matters described in the second embodiment can be adopted in the first embodiment.

[0063] The artificial blood vessel 1 manufactured in the method for manufacturing an artificial blood vessel in the second embodiment may be the artificial blood vessel 1A in the first embodiment, or it may be any other artificial blood vessel.

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

[0065] As illustrated in Figure 14, in the second step ST2, polytetrafluoroethylene is irradiated with an ion beam BM. The second step ST2 is an irradiation step. The irradiation step (second step ST2) includes irradiating polytetrafluoroethylene with an ion beam BM so that an ion implantation layer 30 is formed on the cylindrical sheet 2.

[0066] In the example shown in Figure 14, the irradiation step (second step ST2) includes irradiating the inner surface of the cylindrical sheet 2 with an ion beam BM. Irradiation of the inner surface of the cylindrical sheet 2 with the ion beam BM causes the inner surface of the cylindrical sheet 2 to become a roughened surface 31r. Irradiation of the inner surface of the cylindrical sheet 2 with the ion beam BM also causes the inner surface of the cylindrical sheet 2 to become the inner circumferential surface 31 of the ion implantation layer 30 (see, for example, Figure 2). In the example shown in Figure 14, the ion irradiation device 8a is equipped with a magnet (for example, a superconducting magnet 81) for deflecting 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 tubular sheet 2 with the ion beam BM. However, if the technology described in Japanese Patent Publication No. 5-128993 is adapted for the manufacture of the artificial blood vessel 1, it is not impossible to irradiate the inner surface of the tubular sheet 2 with the ion beam BM.

[0068] Alternatively, as illustrated in Figures 15 and 16, after the irradiation step (second step ST2), the cylindrical sheet 2 may be inverted so that the outer surface 2t becomes the inner surface. This inversion causes the inner surface of the cylindrical sheet 2 to become the roughened surface 31r. Furthermore, this inversion causes the inner surface of the cylindrical sheet 2 to become the inner circumferential surface 31 of the ion implantation layer 30.

[0069] As illustrated in Figure 1, Figure 7, or Figure 9, the tubular sheet 2 includes an ion-implanted layer 30 as an inner layer. The main component of the ion-implanted layer 30 is polytetrafluoroethylene. The inner circumferential surface 31 of the ion-implanted layer 30 is composed of a roughened surface 31r mainly composed of polytetrafluoroethylene.

[0070] In a second embodiment, a method for manufacturing an artificial blood vessel 1 having an inner circumferential surface 31 that appropriately acts on blood flow is provided.

[0071] (Optional additional configuration) Next, we will describe optional additional configurations that can be adopted in the manufacturing method of the artificial blood vessel 1 in the second embodiment.

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

[0073] The tubular sheet 2 prepared in the preparation step (first step ST1) may contain polytetrafluoroethylene as its main component. In other words, the proportion of polytetrafluoroethylene in the total material constituting the tubular sheet 2 may be 50 weight percent or more. The proportion of polytetrafluoroethylene constituting the tubular sheet 2 in the total material constituting the tubular sheet 2 may be 70 weight percent or more, 90 weight percent or more, 95 weight percent or more, or 99 weight percent or more. The tubular sheet 2 prepared in the preparation step (first step ST1) may be made of ePTEF. It is preferable that the tubular sheet 2 prepared in the preparation step (first step ST1) is a sheet in which polytetrafluoroethylene is exposed on the surface. In the example shown in Figure 13, polytetrafluoroethylene is exposed on the outer circumferential surface of the tubular sheet 2 prepared in the preparation step (first step ST1). Also, polytetrafluoroethylene is exposed on the inner circumferential surface of the tubular sheet 2 prepared in the preparation step (first step ST1).

[0074] The film thickness of the tubular sheet 2 prepared in the preparation step (first step ST1) is, for example, 0.01 mm or more and 2 mm or less. The film thickness of the tubular sheet 2 may also 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] In the example shown in Figure 13, 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) may also be a tubular body formed by extrusion molding.

[0076] As illustrated in Figure 14 or Figure 15, in the second step ST2 (irradiation step), the polytetrafluoroethylene is irradiated with an ion beam BM so that an ion implantation layer 30 is formed on the cylindrical sheet 2. In the irradiation step (second step ST2), the ion beam BM irradiated onto the polytetrafluoroethylene may contain argon ions, neon ions, or other ions. In other words, in the irradiation step (second step ST2), the element ion-implanted into the polytetrafluoroethylene may be argon, neon, or other elements.

[0077] As illustrated in Figure 14, the irradiation step (second step ST2) may include irradiating the inner surface of the cylindrical sheet 2 with an ion beam BM so that the inner surface 2n of the cylindrical sheet 2 is roughened.

[0078] In the example shown in Figure 14, the angle α between the direction parallel to the longitudinal direction of the tubular sheet 2 and the direction in which the ion beam BM is incident on the polytetrafluoroethylene is between 45 degrees and 90 degrees. Preferably, this angle α is between 60 degrees and 70 degrees, 80 degrees and 85 degrees and above. An angle α of 45 degrees or more results in a good topology of the roughened surface 31r. In contrast, in the method described in Patent Document 2, the angle between the direction parallel to the longitudinal direction of the tube and the direction of travel of the ion beam BM is 1.7 degrees, and the ions cannot penetrate deeply into the inner layer of the tube. In other words, in the method described in Patent Document 2, a roughened surface that acts suitably on blood flow is not sufficiently formed. Furthermore, in the method described in Patent Document 2, the asymmetry of the topology of the roughened surface becomes excessive, which may restrict the direction in which the tube can be attached to the blood vessel.

[0079] As illustrated in Figure 15, the irradiation step (second step ST2) may include irradiating the outer surface 2t of the cylindrical sheet 2 with an ion beam BM so that the outer surface 2t of the cylindrical sheet 2 is roughened. In other words, the step 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] In the example shown in Figure 15, the angle α between the direction parallel to the longitudinal direction of the tubular sheet 2 and the direction in which the ion beam BM is incident on the polytetrafluoroethylene is between 45 degrees and 90 degrees. Preferably, this angle α is 60 degrees or more, 70 degrees or more, 80 degrees or more, or 85 degrees or more. An angle α of 45 degrees or more results in a good topology of the roughened surface 31r.

[0081] The irradiation process (second step ST2) may be performed with the cylindrical sheet 2 rotating around the first axis AX1. In other words, the ion irradiation device 8b may irradiate the outer surface 2t of the cylindrical sheet 2, which is 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 may rotate around the first axis AX1.

[0082] The irradiation process (second step ST2) forms an ion-implanted layer 30 (more specifically, a layer in which ion-implanted elements are mixed with polytetrafluoroethylene) on the tubular sheet 2. After the irradiation process (second step ST2), a layer containing drug K may be added to the surface of the ion-implanted layer 30. Since drug K has already been described in the first embodiment, a repeated explanation of drug K will be omitted.

[0083] As illustrated in Figures 16 and 17, the cylindrical sheet 2 may be inverted in the third step ST3. The third step ST3 is an inversion step. In the inversion step (third step ST3), the cylindrical sheet 2 is inverted so that the outer surface 2t of the cylindrical sheet 2 becomes the inner surface. By inverting the cylindrical sheet, the outer surface 2t of the cylindrical sheet 2 that has been irradiated with the ion beam becomes the inner surface of the cylindrical sheet 2.

[0084] In the examples shown in Figures 16 and 17, the ion-implanted layer 30 becomes the inner layer of the tubular sheet 2 through the process of inverting the tubular sheet. In addition, the inner circumferential surface 31 of the ion-implanted layer 30 becomes the roughened surface 31r. Since the ion-implanted layer 30, the inner circumferential surface 31, and the roughened surface 31r have already been explained in the first embodiment, a repeated explanation of the ion-implanted layer 30, the inner circumferential surface 31, and the roughened surface 31r will be omitted.

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

[0086] As illustrated in Figure 18, in the fourth step ST4, the outer circumferential surface 41 of the cylindrical sheet 2 may be irradiated with an ion beam BM2. The fourth step ST4 is a second irradiation step. The second irradiation step (fourth step ST4) includes irradiating the outer circumferential surface 41 of the cylindrical sheet 2 with an ion beam BM2 so that a second ion implantation layer 40 is formed on the cylindrical sheet 2. By irradiating the outer circumferential surface 41 of the cylindrical sheet 2 with an ion beam BM2, at least a portion of the outer circumferential surface 41 of the cylindrical sheet 2 becomes a second roughened surface 41r (see Figure 8 or Figure 10 if necessary). 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 irradiated onto the outer surface 41 of the cylindrical sheet 2 may 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) may be argon, neon, or other elements.

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

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

[0090] In the example shown in Figure 19, after the second irradiation step (fourth step ST4), the outer 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] In the example shown in Figure 19, after the second irradiation step (fourth step ST4), the outer 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] In the example shown in Figure 19, after the second irradiation step (fourth step ST4), the outer circumferential surface 415 of the longitudinal central region 25 of the tubular sheet 2 is an unroughened surface. In other words, after the second irradiation step (fourth step ST4), the outer circumferential surface 415 of the longitudinal central region 25 of the tubular sheet 2 is maintained in an unroughened state.

[0093] In the example shown in Figure 18 (or Figure 19), the second irradiation step (fourth step ST4) may be performed while the cylindrical sheet 2 is rotating around the second axis AX2. In other words, the ion irradiation device 8b may irradiate the outer circumferential surface 41 of the cylindrical sheet 2, which is rotating around the second axis AX2, with the 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 may rotate around the second axis AX2. The second axis AX2 may be the same as the first axis AX1, or it may be different from the first axis AX1.

[0094] After the irradiation step illustrated in Figure 14 (second step ST2), the second irradiation step illustrated in Figure 18 or Figure 19 (fourth step ST4) may be performed. Alternatively, the second irradiation step illustrated in Figure 18 or Figure 19 (fourth step ST4) may be performed before the irradiation step illustrated in Figure 14 (second step ST2). Furthermore, alternatively, the second irradiation step illustrated in Figure 18 or Figure 19 (fourth step ST4) may be performed after the inversion step illustrated in Figure 16 (third step ST3).

[0095] As illustrated in Figure 20, after the second irradiation step (fourth step ST4), a bioadhesive J may be added to the surface of the second ion implantation layer 40. Alternatively, or additionally, as illustrated in Figure 21, after the second irradiation step (fourth step ST4), a coating CT (for example, a layer of biocompatible polymer material that prevents blood leakage) may be added to the surface of the second ion implantation layer 40. The coating CT (more specifically, a layer of biocompatible polymer material) includes, for example, a gel-like polymer (more specifically, a biopolymer such as collagen, and / or a biocompatible polymer such as polyethylene glycol). In the example shown in Figure 21, since the coating CT (for example, a coating CT containing collagen, or a coating CT containing polyethylene glycol) is added to the surface of the second ion implantation layer 40 (more specifically, the surface of the second ion implantation layer 40 mainly composed of polytetrafluoroethylene), the adhesion between the second roughened surface 41r, which is the surface of the second ion implantation layer 40, and the coating CT is good.

[0096] The addition of a coating CT (for example, a coating CT containing collagen, or a coating CT containing polyethylene glycol) to the surface of the second ion implantation layer 40 (more specifically, the surface of the second ion implantation layer 40 mainly composed of polytetrafluoroethylene) is also applicable to the artificial blood vessel 1A in the first embodiment described above. In the first embodiment, the ion implantation layer 30 is, for example, non-gel. In the first embodiment, a gel-like coating layer (for example, a gel-like coating layer containing collagen, or a gel-like coating layer containing polyethylene glycol) may be added to the surface of the ion implantation layer 30 (more specifically, to the surface of the non-gel-like ion implantation layer 30). Also, in the first embodiment, the second ion implantation layer 40 is, for example, non-gel. In the first embodiment, a gel-like coating layer (for example, a gel-like coating layer containing collagen, or a gel-like coating layer containing polyethylene glycol) may be added to the surface of the second ion implantation layer 40 (more specifically, to the surface of the non-gel-like second ion implantation layer 40).

[0097] Furthermore, the technical consideration of coating the surface of the ion-implanted layer of a sheet applied to blood vessels with a biocompatible polymer material (e.g., a polytetrafluoroethylene-based substrate) in order to improve adhesion between the substrate and the biocompatible polymer material (e.g., collagen and / or polyethylene glycol) coated on the substrate, can also be applied to vascular patches. In this case, the vascular patch applied to blood vessels would have, for example, the following configuration. (1) The vascular patch comprises a sheet that covers the damaged area of ​​the blood vessel wall (e.g., a pore in the blood vessel wall), (2) the sheet includes an ion implantation layer (the ion implantation layer is, for example, non-gel-like), (3) the main component of the ion implantation layer is polytetrafluoroethylene, (4) the surface of the ion implantation layer is composed of a roughened surface mainly composed of polytetrafluoroethylene, and (5) the surface of the ion implantation layer is coated with a biocompatible polymer material that will come into contact with the blood vessel wall (e.g., a gel-like polymer material coating, more specifically, a coating containing collagen and / or polyethylene glycol). The biocompatible polymer material coating (e.g., a gel-like polymer material coating) may be configured to come into contact with blood flow (in other words, blood flowing through the blood vessel) through the damaged area of ​​the blood vessel wall (e.g., a pore in the blood vessel wall). The adhesion between polytetrafluoroethylene and biocompatible polymer materials (e.g., collagen and / or polyethylene glycol) is improved by the roughened surface of the ion-implanted layer, thereby suppressing the peeling of the biocompatible polymer material from the polytetrafluoroethylene when in contact with blood flow. Note that the biocompatible polymer material may dissolve into the blood flow (dissolution is different from peeling). Furthermore, the biocompatible polymer material may be biodegradable. The coating is applied after ion implantation of the polytetrafluoroethylene. In other words, after the ion-implanted layer is formed on the sheet, the coating is applied to the surface of the ion-implanted layer.Since the ion-implanted layer and the roughened surface have already been described in the first embodiment, a repeated explanation of the ion-implanted layer and the roughened surface will be omitted.

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

[0099] As illustrated in Figure 23, 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 tubular sheet 2 on the second direction DR2 side with an ion beam BM4. When the end face 23e of the tubular sheet 2 on the second direction DR2 side is irradiated with the ion beam BM4, the end face 23e of the tubular sheet 2 on the second direction DR2 side becomes a fourth roughened surface 23r.

[0100] (Other embodiments) In the first embodiment (excluding the description section for "(drug)"), the terms "blood," "first blood vessel," "second blood vessel," and "artificial blood vessel" may be replaced with "body fluid," "first tubular tissue," "second tubular tissue," and "tubular prosthesis," respectively.

[0101] For example, another embodiment relates to the tubular prosthesis shown below.

[0102] (1) Equipped with a tubular sheet that defines the space through which bodily fluids flow, The tubular sheet includes an ion implantation layer as an inner layer, The main component of the ion implantation layer is polytetrafluoroethylene. The inner surface of the ion implantation layer is composed of a roughened surface mainly composed of polytetrafluoroethylene. Tubular prosthesis. (2) The ion implantation layer is composed of a single layer in which elements implanted by ion implantation are mixed with the polytetrafluoroethylene. The tubular prosthesis described in (1) above. (3) At least a portion of the roughened surface, which is mainly composed of polytetrafluoroethylene, is exposed to the space through which the bodily fluid flows. A tubular prosthesis as described in (1) or (2) above. (4) The tubular sheet is seamless. A tubular prosthesis as described in any one of (1) to (3) above. (5) At least a portion of the outer surface of the cylindrical sheet is a second roughened surface. A tubular prosthesis as described in any one of the above items (1) to (4). (6) At least a portion of the outer surface of the cylindrical sheet is a non-roughened surface. The tubular prosthesis described in (5) above. (7) 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 toward the first direction is the third roughened surface. A tubular prosthesis as described in any one of the above (1) to (6).

[0103] In the first embodiment, the terms "blood," "first blood vessel," "second blood vessel," and "artificial blood vessel" may be replaced with "lymphatic fluid," "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" may 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" may 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" may be replaced with "body fluid" and "tubular prosthesis," respectively.

[0105] For example, another embodiment relates to a method for manufacturing a tubular prosthesis as shown below.

[0106] (1) A step of preparing a tubular sheet containing polytetrafluoroethylene, The process involves irradiating the polytetrafluoroethylene with an ion beam so that an ion implantation layer is formed on the tubular sheet, It is equipped with, The tubular sheet includes the ion implantation layer as an inner layer, The main component of the ion implantation layer is the polytetrafluoroethylene, The inner surface of the ion implantation layer is composed of a roughened surface mainly composed of polytetrafluoroethylene. A method for manufacturing tubular prostheses. (2) The angle between the direction parallel to the longitudinal direction of the tubular sheet and the direction in which the ion beam is incident on the polytetrafluoroethylene is 45 degrees or more. A method for manufacturing a tubular prosthesis as described in (1) above. (3) The process includes the step of inverting the cylindrical sheet so that the outer surface of the cylindrical sheet becomes the inner surface, The step of irradiating the polytetrafluoroethylene with the ion beam includes irradiating the outer surface of the cylindrical sheet with the ion beam. By inverting the cylindrical sheet, the outer surface irradiated with the ion beam becomes the inner surface. A method for manufacturing a tubular prosthesis as described in (1) or (2) above. (4) The process includes irradiating the outer surface of the cylindrical sheet with an ion beam so that a second ion implantation layer is formed on the cylindrical sheet, After the step of irradiating the outer surface of the cylindrical sheet with the ion beam, a bio-adhesive is applied to the surface of the second ion-implanted layer. A method for manufacturing a tubular prosthesis as described in any one of (1) to (3) above.

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

[0108] The present invention is not limited to the embodiments or modifications described above, and it is clear that each embodiment or modification can be appropriately modified or changed within the scope of the technical concept of the present invention. Furthermore, the various technologies used in each embodiment or modification can be applied to other embodiments or other modifications, as long as no technical inconsistencies arise. In addition, any optional additional configurations in each embodiment or modification can be omitted as appropriate. [Explanation of symbols]

[0109] 1, 1A: Artificial blood vessel 2: Cylindrical sheet 2n: Inner 2t: External surface 8a, 8b: Ion irradiation device 9: Blood vessels 9a: 1st 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: Longitudinal central region 30: Ion implantation layer 30d: Dent 31: Inner peripheral surface 31r: Roughened surface 40: Ion implantation layer 41: Outer surface 41r: Roughened surface 41s: Unroughened surface 81: Superconducting Magnet 90: Organization 311: Inner peripheral surface 311r: Roughened surface 411: Outer surface 411r: Roughened surface 413: Outer surface 413r: Roughened surface 415: Outer surface 415r: Roughened surface AX1: 1st axis AX2: 2nd axis BM, BM2, BM3, BM4: Ion beam CT: Coating DR1: 1st direction DR2: 2nd direction J: Bioadhesive K: Drugs K1: Anticoagulant K2: A drug that regulates the progression of vascular endothelial cells. MK: Mask PT: In vivo tissue RG1: 1st area RG2: 2nd area SP: space

Claims

1. It is equipped with a tubular sheet that defines the space through which blood flows, The tubular sheet includes an ion implantation layer as an inner layer, The main component of the ion implantation layer is polytetrafluoroethylene. The inner surface of the ion implantation layer is composed of a roughened surface mainly composed of polytetrafluoroethylene. The tubular sheet includes a second ion implantation layer as an outer layer, At least a portion of the outer surface of the tubular sheet is a second roughened surface formed by the surface of the second ion implantation layer, The end face of the first end of the tubular sheet includes a third roughened surface formed by the surface of the third ion implantation layer. Artificial blood vessel.

2. The ion-implanted layer is composed of a single layer in which elements implanted by ion implantation are mixed with the polytetrafluoroethylene. The artificial blood vessel according to claim 1.

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

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

5. The maximum height roughness of the roughened surface is different from the maximum height roughness of the second roughened surface. The artificial blood vessel according to any one of claims 1 to 3.

6. At least a portion of the outer surface of the tubular sheet is a non-roughened surface. The artificial blood vessel according to any one of claims 1 to 3.

7. The inner circumferential surface of the ion implantation layer is supported with a drug. The artificial blood vessel according to any one of claims 1 to 3.

8. The aforementioned drug includes an anticoagulant. The artificial blood vessel according to claim 7.

9. A process for preparing a tubular sheet containing polytetrafluoroethylene, The process involves irradiating the polytetrafluoroethylene with an ion beam so that an ion implantation layer is formed on the tubular sheet, The process involves irradiating the outer surface of the cylindrical sheet with an ion beam so that a second ion implantation layer is formed on the cylindrical sheet, A step of irradiating the end face on the first direction side of the cylindrical sheet with an ion beam so that the end face on the first direction side of the cylindrical sheet becomes a roughened surface, When the direction opposite to the first direction is defined as the second direction, the process involves irradiating the end face of the cylindrical sheet on the second direction side with an ion beam so that the end face of the cylindrical sheet on the second direction side becomes a roughened surface. It is equipped with, The tubular sheet includes the ion implantation layer as an inner layer, The main component of the ion implantation layer is the polytetrafluoroethylene, The inner surface of the ion implantation layer is composed of a roughened surface mainly composed of polytetrafluoroethylene. The tubular sheet includes the second ion implantation layer as an outer layer. A method for manufacturing artificial blood vessels.

10. In the step of irradiating the polytetrafluoroethylene with the ion beam so that the ion implantation layer is formed on the tubular sheet, the angle between the direction parallel to the longitudinal direction of the tubular sheet and the direction in which the ion beam is incident on the polytetrafluoroethylene is 45 degrees or more. A method for manufacturing an artificial blood vessel according to claim 9.

11. The process includes a step of inverting the cylindrical sheet so that the outer surface of the cylindrical sheet becomes the inner surface, The step of irradiating the polytetrafluoroethylene with the ion beam so that the ion implantation layer is formed on the tubular sheet includes irradiating the outer surface of the tubular sheet with the ion beam. By inverting the cylindrical sheet, the outer surface irradiated with the ion beam becomes the inner surface. A method for manufacturing an artificial blood vessel according to claim 9 or 10.

12. After performing the step of irradiating the polytetrafluoroethylene with the ion beam so that the ion implantation layer is formed on the tubular sheet, a layer containing a drug is added to the surface of the ion implantation layer. A method for manufacturing an artificial blood vessel according to claim 9 or 10.

13. After the step of irradiating the outer surface of the cylindrical sheet with the ion beam, at least one of a bioadhesive and a coating to prevent blood leakage is applied to the surface of the second ion implantation layer. A method for manufacturing an artificial blood vessel according to claim 9 or 10.

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