Vascular access device

Abstract

The objective is to provide a vascular access device that can reduce the risk of damage to artificial blood vessels during puncture. [Solution] The vascular access device 9 includes an artificial blood vessel 91 and an access port 92 that protrudes radially from the artificial blood vessel 91. The artificial blood vessel 91 includes a curved portion 911a adjacent to the access port 92 that curves convexly toward the access port 92. It is preferable that the access port 92 contains an elastomer.

Description

[Technical Field]

[0001] This invention relates to a vascular access device. [Background technology]

[0002] Hemodialysis is a life-sustaining treatment for patients with chronic renal failure. It involves drawing blood from the body two to three times a week and using a device called a dialyzer to remove waste and excess fluid.

[0003] Methods for removing blood from the body and returning it include CVC (Central Venous Catheter), which involves placing a catheter in the patient's central vein to withdraw and return blood; AVF (Arteriovenous Fistula), which involves short-circuiting the patient's own vein and artery to increase blood flow and then inserting a needle into the enlarged vein to withdraw and return blood; and AVG (Arteriovenous Graft), which involves using an artificial blood vessel to short-circuit a vein and artery and then inserting a needle into the artificial blood vessel to withdraw and return blood.

[0004] While CVCs have the advantage of allowing immediate initiation of hemodialysis, they have the disadvantage of being prone to thrombosis and infection. AVFs, which use the patient's own blood vessels, have the advantage of being less prone to thrombosis and infection due to the protective function of immune cells such as macrophages. However, there are challenges such as some patients having veins that do not widen (inmaturation), vascular deterioration and aneurysm formation due to repeated punctures, and hematoma formation due to puncture errors. On the other hand, AVGs have a higher infection rate than AVFs, but they can be used in patients whose veins do not widen with AVFs, and there are high expectations for them as a new vascular access device in light of the aging of dialysis patients in recent years (see Non-Patent Literature 1).

[0005] In recent years, Shawn M. Gage et al. have devised a new vascular access artificial blood vessel with a puncture access port (see Patent Document 1). Shawn et al. have attempted to visually identify the puncture site of the implanted artificial blood vessel from the skin surface by the raised outer circumference of the chamber, by providing a puncture site for dialysis in the artificial blood vessel and surrounding the puncture site with a chamber, thereby avoiding the risk of puncturing the posterior wall of the artificial blood vessel and causing bleeding due to puncture error (see Non-Patent Document 2). However, there are concerns that the chamber is large, placing a heavy burden on the patient, and that the continuous pressure and irritation of the skin by the chamber may cause skin lacerations. [Prior art documents] [Non-patent literature]

[0006] [Non-Patent Document 1] Lawson JH, Niklason LE, Roy-Chaudhury P. Challenges and novel therapies for vascular access in haemodialysis. Nat Rev Nephrol. 2020 Oct;16(10):586-602. doi: 10.1038 / s41581-020-0333-2. Epub 2020 Aug 24. PMID: 32839580; PMCID: PMC8108319. [Non-Patent Document 2] Gage SM, Lawson M, Nichols C, Sycks D, Manson RJ, Knight JA. An immediate access dialysis graft designed to prevent needle-related complications: Results from the initial pre-clinical studies. J Vasc Access. 2020 May;21(3):328-335. doi: 10.1177 / 1129729819874987. Epub 2019 Sep 16. PMID: 31526086; PMCID: PMC7274852. [Patent Documents]

[0007] [Patent Document 1] US 2021 / 0346585 A1 [Overview of the project] [Problems that the invention aims to solve]

[0008] The present invention aims to provide a vascular access device that can reduce the risk of damage to artificial blood vessels during puncture. [Means for solving the problem]

[0009] To solve this problem, the vascular access device of the present invention comprises the configuration described in [1] below. Hereinafter, [1], [2], etc. may be referred to as item 1, item 2, etc. [1] Artificial blood vessels and The artificial blood vessel includes an access port protruding radially from the artificial blood vessel, The artificial blood vessel includes a curved portion adjacent to the access port that curves convexly toward the access port, Vascular access device.

[0010] [1] According to [1], since vascular access devices include access ports that protrude radially from the artificial blood vessel, the pain of puncture can be avoided or reduced by placing the devices such that at least a portion of the access ports is exposed from the skin.

[0011] Furthermore, because the artificial blood vessel includes a curved section (i.e., a portion that curves convexly toward the access port), the distance from the tip of the needle entering the lumen to reaching the artificial blood vessel wall can be extended. Therefore, the risk of damage to the artificial blood vessel during puncture (specifically, the risk of damage to the artificial blood vessel by the tip of the needle entering the lumen) can be reduced. Consequently, the risk of complications resulting from damage to the artificial blood vessel (e.g., the development of aneurysms and hematomas) can be reduced.

[0012] The vascular access device of the present invention preferably has the following configuration [2] to [8] (i.e., items 2 to 8). [2] The vascular access device according to [1], wherein the lengthwise dimension of the access port is greater than the widthwise dimension of the access port, and the lengthwise direction is parallel to the longitudinal direction of the artificial blood vessel. Here, "longitudinal direction of the artificial blood vessel" refers to the direction parallel to the line connecting the two ends of the artificial blood vessel when it is stretched. In other words, "longitudinal direction of the artificial blood vessel" refers to the direction parallel to the straight line passing through the two ends of the stretched artificial blood vessel. [3] The access port includes an access surface for being punctured with a needle, The access surface is inclined with respect to the longitudinal direction of the access port. Vascular access devices as described in [1] or [2]. [4] The curved portion includes a first portion that approaches the upper end of the access surface in the height direction of the access port as it advances in the first longitudinal direction of the artificial blood vessel, and a second portion that moves away from the upper end of the access surface in the height direction of the access port as it advances in the first direction, The lower end of the access surface is downstream in the first direction from the first part. extends a virtual plane including the height direction and the length direction of the access port, and at least one virtual perpendicular line intersecting the access surface perpendicularly passes through at least one of the center points of the inner diameter of the first part. The vascular access device according to [3]. Here, the "first direction" means one direction in the longitudinal direction of the artificial blood vessel. [5] The vascular access device according to any one of [1] to [4], wherein the access port includes a protrusion including an access surface for being pierced by a needle. [6] The vascular access device according to any one of [1] to [5], wherein the access port includes a recess including an access surface for being pierced by a needle. [7] The access port includes an access surface for being pierced by a needle. The access surface is indicated by at least one of color and a line. The vascular access device according to any one of [1] to [6]. [8] The vascular access device according to any one of [1] to [7], wherein the access port includes an elastomer.

[0013] The vascular access device of the present invention preferably also has the following configuration. [9] The vascular access device according to any of the preceding paragraphs, wherein the dimension in the width direction of the access port (i.e., the width of the access port) is larger than the thickness of the artificial blood vessel.

[10] The vascular access device according to any of the preceding paragraphs, wherein the artificial blood vessel includes a porous body having a tubular shape.

[11] The vascular access device according to any of the preceding paragraphs, wherein the artificial blood vessel includes a biodegradable material in the communication holes of the porous body.

[12] The vascular access device according to any of the preceding paragraphs, wherein the biodegradable material has cell adhesion properties.

[13] The vascular access device according to any of the preceding paragraphs, wherein the biodegradable material is a cross-linked gelatin gel.

[14] The vascular access device according to any one of the preceding paragraphs, wherein the access port includes a main portion including the access surface and a peripheral portion covering at least a part of the main portion.

[15] The main part includes the upper surface including the access surface, The surrounding portion covers at least a part of the side surface of the main portion. A vascular access device as described in any of the preceding paragraphs.

[16] The vascular access device according to any of the preceding paragraphs, wherein the main part includes the elastomer.

[17] The vascular access device according to any of the preceding paragraphs, wherein the surrounding portion includes a porous material.

[18] The vascular access device according to any of the above items, wherein the surrounding portion contains a biodegradable material within the communication holes of the porous body.

[19] The vascular access device according to any of the preceding paragraphs, wherein the biodegradable material in the surrounding area has cell adhesion properties.

[20] The vascular access device according to any of the preceding paragraphs, wherein the biodegradable material in the surrounding area is a cross-linked gelatin gel. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide a vascular access device that can reduce the risk of damage to artificial blood vessels during puncture. [Brief explanation of the drawing]

[0015] [Figure 1A] This is a schematic side view of the vascular access device of this embodiment. [Figure 1B] Figure 1A shows a schematic cross-sectional view of the vascular access device after it has been cut along the IB cutting line. [Figure 1C] Figure 1B shows a schematic cross-sectional view of the vascular access device after it has been cut along the IC cutting line. [Figure 1D] This figure shows a schematic cross-sectional view of the vascular access device of this embodiment when it is implanted in a living organism. The figure also shows a needle inserted into the vascular access device along a virtual perpendicular (specifically, a virtual perpendicular extending from a virtual plane that includes the height and length directions of the access port and intersects perpendicularly with the access surface). [Figure 2A] This is a schematic side view of a vascular access device according to a modified example of this embodiment. [Figure 2B] Figure 2A shows a schematic cross-sectional view of the vascular access device after it has been cut along the IIB cutting line. [Figure 2C] Figure 2B shows a schematic cross-sectional view of the vascular access device after it has been cut along the IIC cutting line. [Figure 2D] This figure shows a schematic cross-sectional view of the vascular access device of this embodiment when it is implanted in a living organism. The figure also shows a needle inserted into the vascular access device along a virtual perpendicular (specifically, a virtual perpendicular extending from a virtual plane that includes the height and length directions of the access port and intersects perpendicularly with the access surface). [Figure 3A] This is a schematic side view of a vascular access device according to a further modification of this embodiment. [Figure 3B] This is a schematic diagram showing the vascular access device as viewed in the direction of arrow IIIB, as indicated in Figure 3A. [Modes for carrying out the invention]

[0016] Embodiments of the present invention will be described in detail below.

[0017] <1. Vascular Access Device> As shown in Figures 1A, 1B, 1C, and 1D, the vascular access device 9 of this embodiment includes an artificial blood vessel 91 and an access port 92 protruding radially from the artificial blood vessel 91. Because the vascular access device 9 includes an access port 92 protruding radially from the artificial blood vessel 91, the pain of puncture can be avoided or reduced by implanting the device such that at least a portion of the access port 92 is exposed from the skin. The artificial blood vessel 91 and the access port 92 can be joined by any method. They may be sutured together, joined with adhesive, welded with a solvent, or heat-welded. Because the access port 92 is joined to the artificial blood vessel 91, the effort of joining them together can be avoided when implanting the vascular access device 9.

[0018] The longitudinal direction D1 of the artificial blood vessel 91 refers to the direction parallel to the direction connecting the two ends of the artificial blood vessel 91 when the artificial blood vessel 91 is stretched. In other words, the longitudinal direction D1 of the artificial blood vessel 91 refers to the direction parallel to the straight line passing through both ends of the stretched artificial blood vessel 91. One direction in the longitudinal direction D1 of the artificial blood vessel 91 is called the first direction D11, and the other direction is called the second direction D12. Of the two ends of the artificial blood vessel 91, the upstream end in the first direction D11 is called the first end, and the downstream end in the first direction D11 is called the second end.

[0019] The longitudinal direction of the access port 92 is parallel to the longitudinal direction D1 of the artificial blood vessel 91.

[0020] <1.1.Artificial blood vessel> The artificial blood vessel 91 has an inner surface (hereinafter sometimes referred to as the "inner surface") and an outer surface. The artificial blood vessel 91 may be, for example, a straight type, a tapered type, or a short tapered type. Among these, the straight type is preferred. Here, the straight type means a shape in which the inner diameter is constant throughout the entire artificial blood vessel 91. Both ends of the artificial blood vessel 91 are open.

[0021] The inner diameter of the artificial blood vessel 91 is preferably 4 mm or more and 6 mm or less, and more preferably 5 mm or more and 6 mm or less. In the case of the artificial blood vessel 91 being, for example, a tapered type or a short tapered type, the inner diameter in this specification refers to the maximum inner diameter.

[0022] The thickness of the artificial blood vessel 91 is preferably 0.5 mm or more, and more preferably 1.0 mm or more. On the other hand, the thickness of the artificial blood vessel 91 is preferably 2.0 mm or less, and more preferably 1.5 mm or less.

[0023] The length of the artificial blood vessel 91 may be, for example, 50 mm or more, 100 mm or more, 200 mm or more, or 300 mm or more. The length of the artificial blood vessel 91 may be 600 mm or less, or 500 mm or less. Note that the artificial blood vessel 91 may be cut as necessary for length adjustment before implantation, and in this paragraph, the length of the artificial blood vessel 91 refers to the length before cutting.

[0024] The artificial blood vessel 91 includes a porous body and biodegradable material within the pores of the porous body, specifically within the interconnected pores. Because the artificial blood vessel 91 contains biodegradable material within the interconnected pores of the porous body, the number of empty interconnected pores can increase as the biodegradable material degrades in the body. Therefore, the more the biodegradable material degrades, the more tissues, capillaries, or cells can penetrate into the interconnected pores.

[0025] <1.1.1. Porous materials> The artificial blood vessel 91 includes a porous body, specifically a tubular porous body (hereinafter sometimes referred to as a "porous tube"). The porous tube has an inner surface (hereinafter sometimes referred to as an "inner surface") and an outer surface. Both ends of the porous tube (i.e., the first end and the second end) are open. The porous tube may have a single-layer structure or a multi-layer structure.

[0026] The explanation of the inner diameter of the porous tube is omitted because it overlaps with the explanation of the inner diameter of the artificial blood vessel 91. Therefore, the explanation of the inner diameter of the artificial blood vessel 91 can also be used as an explanation of the inner diameter of the porous tube. However, the inner diameter of the porous tube and the inner diameter of the artificial blood vessel 91 do not need to be the same. That is, the inner diameter of the porous tube and the inner diameter of the artificial blood vessel 91 may be the same or different. For example, the inner diameter of the porous tube may be larger than the inner diameter of the artificial blood vessel 91.

[0027] The explanation of the thickness of the porous tube is omitted because it overlaps with the explanation of the thickness of the artificial blood vessel 91. Therefore, the explanation of the thickness of the artificial blood vessel 91 can also be used as an explanation of the thickness of the porous tube. However, the thickness of the porous tube and the thickness of the artificial blood vessel 91 do not need to be the same. That is, the thickness of the porous tube and the thickness of the artificial blood vessel 91 may be the same or different. For example, the thickness of the porous tube may be smaller than the thickness of the artificial blood vessel 91.

[0028] The explanation of the length of the porous tube is omitted because it overlaps with the explanation of the length of the artificial blood vessel 91. Therefore, the explanation of the length of the artificial blood vessel 91 can also be used as an explanation of the length of the porous tube.

[0029] Porous tubes have connecting pores, or linking pores. Specifically, porous tubes have linking pores extending from the inner surface of the tube to the outer surface of the tube. Therefore, tissues, capillaries, cells, etc., can penetrate the porous tube. Thus, this infiltration can be promoted, and as a result, intimal formation can be promoted.

[0030] The porous tube preferably contains a thermoplastic elastomer. When the porous tube contains a thermoplastic elastomer, it is easy to manufacture. The porous tube may also contain components other than the thermoplastic elastomer (for example, additives).

[0031] Thermoplastic polyurethane elastomers can be cited as an example of thermoplastic elastomers. When a porous tube contains a thermoplastic polyurethane elastomer, the manufacturing of the porous tube is easy. Moreover, in this case, it is possible to give the porous tube entropy elasticity, and therefore, an artificial blood vessel that is easy to implant can be provided.

[0032] Examples of thermoplastic polyurethane elastomers include Pellethane®, ChronoFlex®, ChronoThane®, and HydroThane®. These are preferred because medical-grade versions are commercially available.

[0033] The thermoplastic elastomer preferably has entropic elasticity at at least 30°C to 42°C. The entropic elasticity of the porous tube allows for the provision of an artificial blood vessel that is easy to implant.

[0034] <1.1.2. Biodegradable materials> The artificial blood vessel 91 contains a biodegradable material within the pores of the porous tube, specifically within the connecting pores. Examples of biodegradable materials include cross-linked gelatin gel and collagen. Among these, cross-linked gelatin gel is preferred because its dissolution rate in body fluids can be easily controlled depending on the degree of cross-linking. It is preferable that the cross-linked gelatin gel forms a gel at 40°C.

[0035] <1.1.3. First reinforcing thread> The artificial blood vessel 91 may further include a first thread (hereinafter sometimes referred to as the "first reinforcing thread") that extends spirally in a clockwise direction from the first end to the second end of the porous tube. The first reinforcing thread can prevent or reduce kinking (i.e., the phenomenon in which the lumen of the artificial blood vessel closes due to excessive bending of the artificial blood vessel).

[0036] The first reinforcing thread may extend spirally along the outer surface of the porous tube, for example, or spirally inside the porous tube. In particular, it is preferable that the first reinforcing thread extends spirally inside the porous tube.

[0037] The pitch of the first reinforcing threads may be, for example, 1 mm or more, or 2 mm or more. On the other hand, the pitch of the first reinforcing threads may be, for example, 10 mm or less, or 5 mm or less.

[0038] The diameter of the first reinforcing thread may be, for example, 100 μm or more, or 120 μm or more. On the other hand, the diameter of the first reinforcing thread may be, for example, 200 μm or less, or 180 μm or less.

[0039] Examples of the first reinforcing yarn include filament yarn and spun yarn. Examples of filament yarn include monofilament and multifilament. Monofilament is preferred among these. Examples of monofilament include polyester monofilament, nylon monofilament, and polypropylene monofilament. Polyester monofilament is preferred among these.

[0040] <1.1.4. Second reinforcing thread> The artificial blood vessel 91 may further include a second thread (hereinafter sometimes referred to as the "second reinforcing thread") that extends spirally in a counterclockwise direction from the first end to the second end of the porous tube. The second reinforcing thread can further prevent or reduce kinking.

[0041] The explanation of the second reinforcing thread is omitted as it overlaps with the explanation of the first reinforcing thread. Therefore, the explanation of the first reinforcing thread can also be used as the explanation of the second reinforcing thread.

[0042] <1.1.5. Others> The artificial blood vessel 91 may further include a layer covering the outer surface of the porous tube (hereinafter sometimes referred to as the "coating layer"). The coating layer may contain biodegradable material.

[0043] On the other hand, the artificial blood vessel 91 may further include a layer covering the inner surface of the porous tube. The artificial blood vessel may contain components other than biodegradable materials (e.g., additives) within the pores of the porous tube.

[0044] <1.1.6. Curved Section> The artificial blood vessel 91 includes a portion that curves convexly toward the access port 92, namely a curved portion 911a and a curved portion 911b, located beside the access port 92. Here, the curved portions 911a and 911b can be portions that maintain a convex curve toward the access port 92 when the artificial blood vessel 91 is pulled to the extent that the vascular access device 9 does not break. Because the artificial blood vessel 91 includes curved portions 911a and 911b, the distance from the tip of the needle 6 entering the lumen to reaching the artificial blood vessel wall can be extended. Therefore, the risk of damage to the artificial blood vessel 91 during puncture (specifically, the risk of damage to the artificial blood vessel 91 by the tip of the needle 6 entering the lumen) can be reduced. Hence, the risk of complications resulting from damage to the artificial blood vessel 91 (e.g., aneurysm, hematoma) can be reduced.

[0045] The artificial blood vessel 91 further includes a portion 912 located upstream of the curved portions 911a and 911b in the first direction D11 (hereinafter referred to as the "upstream portion"), and a portion 913 located downstream of the curved portions 911a and 911b in the first direction D11 (hereinafter referred to as the "downstream portion"). The upstream portion 912 and the downstream portion 913 are connected by the curved portions 911a and 911b.

[0046] The curved portion 911a includes a portion 916a that approaches the upper end 30a of the access surface 923a in the height direction of the access port 92 as it moves in the first direction D11 (hereinafter sometimes referred to as the "upward portion"), and a portion 917a that moves away from the upper end 30a of the access surface 923a in the height direction of the access port 92 as it moves in the first direction D11 (hereinafter sometimes referred to as the "downward portion").

[0047] The curved portion 911b further includes a portion 916b that approaches the upper end 30b of the access surface 923b in the height direction of the access port 92 as it moves in the first direction D11 (hereinafter sometimes referred to as the "upward portion"), and a portion 917b that moves away from the upper end 30b of the access surface 923b in the height direction of the access port 92 as it moves in the first direction D11 (hereinafter sometimes referred to as the "downward portion").

[0048] <1.2. Access Port> The height H of the access port 92 may be 1 mm or more, 2 mm or more, or 3 mm or more. The height H of the access port 92 may be 25 mm or less, 20 mm or less, or 15 mm or less. Here, height H is the distance in the height direction of the access port 92 between the upper end 30a of the access surface 923a or the upper end 30b of the access surface 923b and the upper end of the lumen (i.e., the highest point of the lumen). The upper end 30a of the access surface 923a is the upper end of the access surface 923a in the height direction of the access port 92. The upper end 30b of the access surface 923b is the upper end of the access surface 923b in the height direction of the access port 92.

[0049] The length L of the access port 92 may be 10 mm or more, 20 mm or more, or 30 mm or more. The length L of the access port 92 may be 150 mm or less, 130 mm or less, or 110 mm or less. Here, length L refers to the maximum length dimension of the access port 92.

[0050] The width W of the access port 92 may be 5 mm or more, 7 mm or more, or 10 mm or more. The width of the access port 92 may be 30 mm or less, 26 mm or less, or 22 mm or less. Here, the width W of the access port 92 refers to the maximum dimension of the access port 92 in the width direction. The width W of the access port 92 may be greater than, less than, or the same as the diameter of the artificial blood vessel 91. When the width W of the access port 92 is greater than the diameter of the artificial blood vessel 91, it is more convenient for increasing the size of the access surface 923a or access surface 923b compared to when it is smaller than the diameter of the artificial blood vessel 91.

[0051] The length L of the access port 92 is greater than the width W of the access port 92. When the length L of the access port 92 is greater than the width W, it is advantageous for increasing the size of the access surface 923a or access surface 923b in the longitudinal direction of the access port 92 compared to when the length L is less than the width W.

[0052] The access port 92 includes a projection 927a, which protrudes above the surrounding area in the height direction of the access port 92. The access port 92 further includes a projection 927b, which protrudes above the surrounding area in the height direction of the access port 92.

[0053] The height H1 of projection 927a may be 1 mm or more, or 2 mm or more. The height H1 of projection 927a may be 15 mm or less, or 12 mm or less, or 9 mm or less. The length L1 of projection 927a may be 1 mm or more, or 3 mm or more, or 5 mm or more. The length L1 of projection 927a may be 25 mm or less, or 20 mm or less, or 15 mm or less. The description of the height and length of projection 927b is omitted because it overlaps with the description of the height H1 and length L1 of projection 927a. Therefore, the description of the height H1 and length L1 of projection 927a can also be treated as the description of the height and length of projection 927b.

[0054] The projection 927a includes the access surface 923a. The projection 927b includes the access surface 923b. The access surfaces 923a and 923b are surfaces to be pierced by the needle 6. The access surfaces 923a and 923b may be flat or curved, but they are preferably flat.

[0055] The area of ​​the access surface 923a is, for example, 3 mm². 2 It may be greater than or equal to 5mm 2 It may be greater than or equal to 9mm 2 The area may be greater than or equal to 225 mm². 2 The following are also acceptable, 150mm 2 The following may also be true: 100mm 2 The following is also possible: The description of the area of ​​access surface 923a can also be treated as a description of the area of ​​access surface 923b. The areas of access surface 923a and access surface 923b may be the same or different. In particular, it is preferable that the areas of access surface 923a and access surface 923b are the same.

[0056] Access surfaces 923a and 923b are inclined with respect to the longitudinal direction of the access port 92. Because access surfaces 923a and 923b are inclined with respect to the longitudinal direction of the access port 92, the risk of damaging the artificial blood vessel 91 during puncture can be further reduced. This will be explained. Generally, the needle 6 is inserted into the blood vessel at an oblique angle to the surface of the skin 12. Because access surfaces 923a and 923b are inclined with respect to the longitudinal direction of the access port 92, if the needle 6 is inserted straight into access surface 923a or access surface 923b, the needle 6 will naturally be oblique to the surface of the skin 12. Therefore, because access surfaces 923a and 923b are inclined with respect to the longitudinal direction of the access port 92, it is easier to insert the needle 6 into the artificial blood vessel 91 at an oblique angle to the surface of the skin 12. Therefore, the risk of damaging the artificial blood vessel 91 during puncture can be further reduced. Thus, the risk of complications resulting from damage to the artificial blood vessel 91 can be further reduced.

[0057] Regarding the positional relationship between the access surface 923a and the curved section 911a, the lower end 31a of the access surface 923a is downstream of the upward section 916a in the first direction D11. The positional relationship between the access surface 923a and the curved section 911a satisfies the condition that at least one of the virtual perpendiculars extending from a virtual plane including the height and length directions of the access port 92 and intersecting the access surface 923a perpendicularly passes through at least one of the center points of the inner diameter of the upward section 916a. Although the virtual perpendiculars themselves (specifically, virtual perpendiculars extending from a virtual plane including the height and length directions of the access port 92 and intersecting the access surface 923a perpendicularly) are not shown, it is clear from the appearance of the needle 6 inserted into the vascular access device 9 along the virtual perpendiculars that the positional relationship between the access surface 923a and the curved section 911a satisfies this condition. The positional relationship between the access surface 923a and the curved portion 911a satisfies this condition, allowing the tip of the needle 6 to easily enter the lumen of the ascending portion 916a when the needle 6 is inserted from the access surface 923a. Therefore, the distance the tip of the needle 6 travels from the time it enters the lumen until it reaches the artificial blood vessel wall can be extended more frequently. Consequently, the risk of damaging the artificial blood vessel 91 during puncture can be further reduced. Therefore, the risk of complications resulting from damage to the artificial blood vessel 91 can be further reduced. This condition can also be rephrased as the condition that when the access surface 923a is virtually moved along a virtual perpendicular (specifically, a virtual perpendicular extending along a virtual plane including the height and length directions of the access port 92 and intersecting the access surface 923a perpendicularly), the access surface 923a passes through at least one of the center points of the inner diameter of the ascending portion 916a.

[0058] Regarding the positional relationship between the access surface 923b and the curved portion 911b, the lower end 31b of the access surface 923b is downstream of the upward portion 916b in the first direction D11. The positional relationship between the access surface 923b and the curved portion 911b satisfies the condition that at least one of the virtual perpendiculars extending from the virtual plane including the height and length directions of the access port 92, and intersecting the access surface 923b perpendicularly, passes through at least one of the center points of the inner diameter of the upward portion 916b. Because the positional relationship between the access surface 923b and the curved portion 911b satisfies this condition, when the needle 6 is inserted from the access surface 923b, the tip of the needle 6 can easily enter the lumen of the upward portion 916b. Therefore, the distance from the tip of the needle 6 after entering the lumen to reaching the artificial blood vessel wall can be extended more frequently. Thus, the risk of damage to the artificial blood vessel 91 during puncture can be further reduced. Therefore, the risk of complications resulting from damage to the artificial blood vessel 91 can be further reduced.

[0059] The access port 92 includes a portion 921 that includes the top surface 922 (hereinafter sometimes referred to as the "main portion") and a portion 926 that covers at least a part of the side surface of the main portion 921 (hereinafter sometimes referred to as the "surrounding portion").

[0060] <1.2.1. Main Section> The main portion 921 of the access port 92 includes projections 927a and 927b. The upper surface 922 of the main portion 921 includes the surface of projection 927a and the surface of projection 927b. Therefore, the upper surface 922 includes access surfaces 923a and 923b.

[0061] The upper surface 922 is not covered by the surrounding portion 926. Therefore, the vascular access device 9 can be placed such that at least the access surface 923a and the access surface 923b are exposed from the skin 12.

[0062] The main part 921 is formed of an elastomer. That is, the main part 921 contains an elastomer. Because the main part 921 contains an elastomer, when a needle is inserted into or removed from the main part 921, the hole made by the needle can be closed. A thermoplastic elastomer is preferred as the elastomer. When the main part 921 contains a thermoplastic elastomer, the main part 921 is easy to manufacture. Examples of thermoplastic elastomers include styrene-based thermoplastic elastomers, acrylic-based thermoplastic elastomers, olefin-based thermoplastic elastomers, polyester-based thermoplastic elastomers, and polyurethane-based thermoplastic elastomers. Among these, styrene-based thermoplastic elastomers are preferred. Examples of styrene-based thermoplastic elastomers include styrene-butadiene-styrene block copolymers (SBS) and styrene-isoprene-styrene block copolymers (SIS). Hydrogenated styrene-diene-styrene block copolymers can also be used as styrene-based thermoplastic elastomers. The main part 921 may further contain components other than the elastomer (for example, additives).

[0063] The tensile modulus of the elastomer is preferably 250 kPa or higher, and more preferably 300 kPa or higher. When it is 250 kPa or higher, the hole made by the needle can be effectively closed when the needle is inserted into or removed from the main part 921. In other words, it has excellent hemostatic properties. On the other hand, the tensile modulus of the elastomer may be, for example, 1500 kPa or less, or 1000 kPa or less. Here, the tensile modulus of the elastomer can be measured, for example, by the following method. A test specimen measuring 3 mm thick, 50 mm long, and 5 mm wide is cut from the elastomer. A tensile test is performed using a Shimadzu AutographAGS-X 1kN with a gauge length of 30 mm and a tensile speed of 150 mm / min. The cross-sectional area A of the test specimen (unit: m²) is measured. 2 Using the load N1 (in N) when the tensile strain is 1%, and the load N5 (in N) when the tensile strain is 5%, the tensile modulus is calculated using the following formula. A(m2 ) = 3 / 1000 × 5 / 1000 Tensile modulus of elasticity (kPa) = (N5 (N) - N1 (N)) / A (m 2 ) / 0.04 “N5 (N)” means that a value in N units is substituted for N5 in this formula. “N1 (N)” means that a value in N units is substituted for N1 in this formula. “A (m 2 )” means that a value in m 2 units is substituted for A in this formula.

[0064] <1.2.2. Peripheral part> The peripheral part 926 of the access port 92 covers at least a part of the side surface of the main part 921.

[0065] The peripheral part 926 includes an inner surface facing the main part 921 and an outer surface opposite to the inner surface. That is, the peripheral part 926 includes an outer surface and an inner surface located closer to the main part 921 than the outer surface.

[0066] The thickness of the peripheral part 926, that is, the thickness from the inner surface to the outer surface, may be, for example, 0.5 mm or more, or may be 1 mm or more. The thickness of the peripheral part 926 may be 3 mm or less, or may be 2 mm or less.

[0067] The peripheral part 926 preferably includes a porous body. Specifically, the peripheral part 926 includes a porous body having communication holes. Since the peripheral part 926 includes a porous body having communication holes, cells can enter the communication holes. That is, living tissue can infiltrate into the communication holes. Therefore, the access port 92 can be fused with the epidermis, and the progress of downward loosening (that is, the epidermis falling along the access port 92) can be reduced or prevented. The porous body of the peripheral part 926 and the main part 921 can be joined. The porous body of the peripheral part 926 and the main part 921 may be, for example, sutured, joined with an adhesive, welded with a solvent, or welded with heat.

[0068] The porous material of the surrounding portion 926 includes an inner surface facing the main portion 921 and an outer surface opposite the inner surface. That is, the porous material of the surrounding portion 926 includes an outer surface and an inner surface located closer to the main portion 921 than the outer surface. The porous material of the surrounding portion 926 may be a single-layer structure or a multi-layer structure.

[0069] It is preferable that the porous material has connecting pores, i.e., interconnecting pores. It is preferable that the porous material has interconnecting pores extending from the inner surface to the outer surface of the porous material.

[0070] It is preferable that the porous material has at least one peak (hereinafter sometimes referred to as the "L peak") in the log differential pore volume distribution curve, with the peak peak located in the range of pore diameters between 100 μm and 1000 μm. When the porous material has an L peak, that is, has pores of a certain size, biological tissue can penetrate the porous material more easily.

[0071] The L peak may have its peak apex in the range of pore diameters from 105 μm to 1000 μm, or it may have its peak apex in the range of pore diameters from 120 μm to 1000 μm.

[0072] The log differential pore volume of the L peak is preferably 3.0 mL / g or more, and more preferably 4.0 mL / g or more. On the other hand, the log differential pore volume of the L peak may be, for example, 8.0 mL / g or less, or 7.0 mL / g or less.

[0073] It is preferable that the porous material further has at least one peak (hereinafter sometimes referred to as the "S peak") in the log differential pore volume distribution curve, the peak peak having a pore diameter of 100 μm or less.

[0074] The S peak may have its peak apex in the range of pore diameter 60 μm or less, or it may have its peak apex in the range of pore diameter 40 μm or less.

[0075] The log differential pore volume of the S peak is preferably 1.0 mL / g or greater. On the other hand, the log differential pore volume of the S peak may be, for example, 6.0 mL / g or less, or 5.0 mL / g or less.

[0076] Pore ​​size distribution can be measured using the mercury intrusion method. Specifically, the measurement can be performed using the Autopore V9620 pore size distribution analyzer manufactured by Micromeristics, Inc., at an initial pressure of 1.5 kPa.

[0077] It is preferable that the porous body contains an elastomer. In other words, it is preferable that the porous body is a porous elastomer. A thermoplastic elastomer is preferred as the elastomer. When the porous body contains a thermoplastic elastomer, the porous body is easy to manufacture. Examples of thermoplastic elastomers include styrene-based thermoplastic elastomers, acrylic-based thermoplastic elastomers, olefin-based thermoplastic elastomers, polyester-based thermoplastic elastomers, and polyurethane-based thermoplastic elastomers. Among these, polyurethane-based thermoplastic elastomers, i.e., thermoplastic polyurethane elastomers, are preferred. Examples of polyurethane-based thermoplastic elastomers include Pellethane®, ChronoFlex®, ChronoThane®, and HydroThane®. These are preferred because medical-grade versions are commercially available. The porous body may further contain components other than the elastomer (for example, additives).

[0078] The elastomer preferably has entropic elasticity at least 30°C to 42°C.

[0079] Preferably, the surrounding portion 926 further contains a biodegradable material having cell adhesion properties within the pores of the porous material, specifically within the communication pores. When the surrounding portion 926 contains a biodegradable material having cell adhesion properties within the communication pores of the porous material, it can effectively fuse with the epidermis and therefore further reduce or prevent the progression of down growth. This will be explained. When the surrounding portion 926 of the access port 92 contains a biodegradable material having cell adhesion properties, cells can adhere to the biodegradable material. Moreover, since the biodegradable material is located within the communication pores, the number of communication pores into which cells can enter (i.e., empty communication pores) can increase as the biodegradable material degrades in the body. As a result, cells can enter the communication pores by traveling along the biodegradable material. In other words, the biodegradable material can help infiltrate the communication pores of biological tissue. Therefore, if the access port 92 contains a biodegradable material with cell adhesion properties within the communication pores of the porous body, it can effectively fuse with the epidermis, further reducing or preventing the progression of down growth.

[0080] The explanation of the biodegradable material in the surrounding portion 926 is omitted because it overlaps with the explanation of the biodegradable material in the artificial blood vessel 91. Therefore, the explanation of the biodegradable material in the artificial blood vessel 91 can also be used as the explanation of the biodegradable material in the surrounding portion 926.

[0081] <2. Placement> The vascular access device 9 is implanted in such a manner that at least the access surface 923a and the access surface 923b are exposed from the skin 12. By implanting the vascular access device 9 in this manner, the pain of puncture can be avoided or reduced. Note that these figures show an embodiment in which the entire upper surface 922 of the main part 921 of the access port 92 is exposed from the skin 12.

[0082] To place the vascular access device 9, an artery and a vein can be connected with the vascular access device 9. That is, one end of the artificial blood vessel 91 of the vascular access device 9 can be anastomosed to an artery, and the other end of the artificial blood vessel 91 of the vascular access device 9 can be anastomosed to a vein. In this case, the procedure for placing the vascular access device 9 can be, for example, to make an incision in the skin 12 of a living body (for example, the skin of a human arm), connect the artery and vein with the vascular access device 9, and then suture the vascular access device 9 in such a manner that at least the access surface 923a and access surface 923b are exposed from the skin 12. Examples of veins include the cephalic vein, ulnar cephalic vein, and saphenous vein. The blood vessel (specifically, an artery or a vein) and the artificial blood vessel 91 can be sutured together with sutures. In this case, the artificial blood vessel 91 of the vascular access device 9 may be placed in a loop shape or in a straight shape.

[0083] The length of the implanted artificial blood vessel 91 may be, for example, 50 mm or more, or 100 mm or more. The length of the implanted artificial blood vessel 91 may be 600 mm or less, or 500 mm or less.

[0084] <3. Method for manufacturing porous materials> As described above, since both the artificial blood vessel 91 and the surrounding portion 926 of the access port 92 contain porous material, a preferred method for manufacturing a porous tube containing thermoplastic polyurethane elastomer will be described as an example of a method for manufacturing a porous material.

[0085] A method for manufacturing a porous tube may include the steps of: preparing a polyurethane porous material stock solution containing a thermoplastic polyurethane elastomer, dimethyl sulfoxide, and a pore-forming agent insoluble in dimethyl sulfoxide and water-soluble (hereinafter sometimes referred to as the "preparation step"); solidifying the polyurethane porous material stock solution by cooling it while it is in a tubular shape (hereinafter sometimes referred to as the "solidification step"); and washing the solidified tubular material with water (hereinafter sometimes referred to as the "washing step"). According to this manufacturing method, a porous tube can be produced in which pores derived from the pore-forming agent and pores derived from dimethyl sulfoxide crystals are formed. The method for manufacturing a porous tube may further include a step of drying the porous tube obtained by the washing step.

[0086] <3.1. Preparation process> In this step, a polyurethane porous material stock solution is prepared. For example, the polyurethane porous material stock solution can be prepared by mixing and stirring a thermoplastic polyurethane elastomer and dimethyl sulfoxide, then adding a pore-forming agent and stirring, or by mixing dimethyl sulfoxide with the thermoplastic polyurethane elastomer and pore-forming agent and stirring. The former is preferred.

[0087] The temperature of the dimethyl sulfoxide mixed with the thermoplastic polyurethane elastomer is preferably 70°C or higher. At 70°C or higher, the thermoplastic polyurethane elastomer can be easily dissolved in the dimethyl sulfoxide. The temperature of the dimethyl sulfoxide may be, for example, 80°C or higher, or 90°C or higher. The temperature of the dimethyl sulfoxide may be, for example, 150°C or lower, or 120°C or lower.

[0088] The pore-forming agent is a particle that is insoluble in dimethyl sulfoxide but soluble in water. The particle size of the pore-forming agent can be adjusted using a mortar and pestle, sieve, etc. Sodium chloride can be given as an example of a pore-forming agent.

[0089] The thermoplastic polyurethane elastomer content is preferably 3% by mass or more, more preferably 4% by mass or more, and even more preferably 5% by mass or more, based on 100% by mass of the polyurethane porous body stock solution. On the other hand, the thermoplastic polyurethane elastomer content is preferably 7% by mass or less, more preferably 6% by mass or less, and even more preferably 5.5% by mass or less, based on 100% by mass of the polyurethane porous body stock solution.

[0090] The content of the pore-forming agent is preferably 10% by mass or more, more preferably 20% by mass or more, and even more preferably 30% by mass or more, based on 100% by mass of the polyurethane porous body stock solution. On the other hand, the content of the pore-forming agent is preferably 60% by mass or less, more preferably 55% by mass or less, and even more preferably 50% by mass or less, based on 100% by mass of the polyurethane porous body stock solution.

[0091] The total content of thermoplastic polyurethane elastomer, dimethyl sulfoxide, and porosinant is preferably 90% by mass or more, more preferably 95% by mass or more, even more preferably 98% by mass or more, and even more preferably 100% by mass, based on 100% by mass of the polyurethane porous body stock solution.

[0092] <3.2. Solidification process> In this process, the polyurethane porous material stock is solidified by cooling it while it is in a tubular shape. To create the tubular shape of the polyurethane porous material stock, it is preferable to prepare a cylindrical rod and a mold including an inner wall capable of forming a cylindrical cavity concentric with the rod, and then fill the space between the rod and the inner wall (i.e., the tubular space) with the polyurethane porous material stock.

[0093] To solidify the polyurethane porous material stock solution, it is cooled to a temperature below the freezing point of dimethyl sulfoxide. The polyurethane porous material stock solution can be cooled to, for example, 10°C or below, 0°C or below, or -10°C or below.

[0094] <3.3. Washing Process> In this step, the tubular solid formed from the polyurethane porous material stock is washed with water. Since both dimethyl sulfoxide and the pore-forming agent are soluble in water, washing the tubular solid with water removes both the dimethyl sulfoxide and the pore-forming agent from the tubular solid. Therefore, a porous tube can be obtained by washing the tubular solid with water. For washing the tubular solid, for example, tap water, deionized water, distilled water, or ultrapure water can be used. The washing may be performed multiple times. For example, the tube may be washed with water below the freezing point of dimethyl sulfoxide (for example, ice-cold water), and then further washed with warm water at 50°C to 70°C. After washing, the porous tube may be dried.

[0095] <3.4. Other processes> The porous tube may be cut to adjust its length.

[0096] <4. Method for manufacturing a component containing biodegradable material within the pores of a porous body> As described above, since both the artificial blood vessel 91 and the surrounding portion 926 of the access port 92 contain biodegradable material within the pores of the porous body, a preferred method for manufacturing the artificial blood vessel 91 will be described as an example of a method for manufacturing a component containing biodegradable material within the pores of a porous body (i.e., the artificial blood vessel 91 and the surrounding portion 926).

[0097] The method for manufacturing the artificial blood vessel 91 in this embodiment includes the steps of: immersing the pre-immersion artificial blood vessel in an aqueous solution containing a water-soluble biodegradable material under reduced pressure (hereinafter sometimes referred to as the "immersion step"); increasing the atmospheric pressure of the aqueous solution in which the pre-immersion artificial blood vessel is immersed (hereinafter sometimes referred to as the "pressurization step"); removing the post-immersion artificial blood vessel from the aqueous solution (hereinafter sometimes referred to as the "removal step"); and insolubilizing the water-soluble biodegradable material contained in the post-immersion artificial blood vessel (hereinafter sometimes referred to as the "insolubilization step"). The method for manufacturing the artificial blood vessel 91 in this embodiment may further include a step of preparing the pre-immersion artificial blood vessel before the immersion step (hereinafter sometimes referred to as the "preparation step").

[0098] <4.1. Preparation process> In this step, the pre-immersion artificial blood vessel is prepared. The pre-immersion artificial blood vessel may be the same as the artificial blood vessel 91, except that it does not contain biodegradable material in the connecting pores of the porous tube. The pre-immersion artificial blood vessel includes a porous tube. The pre-immersion artificial blood vessel may further include a first reinforcing thread. The pre-immersion artificial blood vessel may further include a second reinforcing thread.

[0099] <4.2. Soaking process> In this process, the unimmersed artificial blood vessel is immersed in an aqueous solution containing a water-soluble biodegradable material under reduced pressure. For example, the unimmersed artificial blood vessel with the core inserted is immersed (i.e., placed) in the aqueous solution in a container, and then the container is placed in a desiccator, the inside of the desiccator is depressurized, and the reduced pressure state is maintained. The diameter of the core is preferably 0.9 to 1.1 times the inner diameter of the porous tube, and more preferably equal to the inner diameter of the porous tube.

[0100] Gelatin is preferred as the water-soluble biodegradable material. The content of the water-soluble biodegradable material in the aqueous solution is preferably 5% by mass or more, and more preferably 7% by mass or more. When it is 5% by mass or more, the gel strength is high and the pressure resistance is high. On the other hand, the content of the water-soluble biodegradable material in the aqueous solution is preferably 15% by mass or less, and more preferably 12% by mass or less. When it is 12% by mass or less, the viscosity of the aqueous solution is low and filling into porous tubes becomes easier.

[0101] A reduced pressure environment is an environment below atmospheric pressure. A reduced pressure environment of 25 kPa or less is preferable, an environment of 20 kPa or less is more preferable, and an environment of 15 kPa or less is even more preferable. This can reduce the porosity of the artificial blood vessel.

[0102] While the artificial blood vessel is immersed in the aqueous solution under reduced pressure before immersion, the temperature of the aqueous solution is preferably 35°C or higher, and more preferably 40°C or higher. This can reduce the porosity of the artificial blood vessel.

[0103] The time for immersing the artificial blood vessel in the aqueous solution under reduced pressure before immersion, i.e., the immersion time under reduced pressure, is preferably 1 minute or more, more preferably 3 minutes or more, and even more preferably 5 minutes or more.

[0104] <4.3. Pressurization Process> In this step, the atmospheric pressure of the aqueous solution in which the artificial blood vessels are immersed is increased. In this step, it is preferable to raise the atmospheric pressure to above atmospheric pressure, and more preferably to atmospheric pressure.

[0105] <4.4. Extraction Process> In this step, the immersed artificial blood vessel is removed from the aqueous solution, and if necessary, any aqueous solution adhering to the surface of the porous tube of the immersed artificial blood vessel is removed.

[0106] <4.5. Immobilization Process> In this step, the water-soluble biodegradable material contained in the artificial blood vessel after immersion is insolubilized. To insolubilize it, it is preferable to irradiate the artificial blood vessel with an electron beam after immersion. This allows the gelatin to be crosslinked without using a crosslinking agent that may affect living organisms, especially when the water-soluble biodegradable material is gelatin. When crosslinking gelatin with an electron beam, the electron beam dose is preferably 20 kGy or more, and more preferably 25 kGy or more. A dose of 20 kGy or more effectively gels the gelatin aqueous solution and also increases the amount of insoluble material. On the other hand, the electron beam dose may be, for example, 80 kGy or less, 60 kGy or less, 50 kGy or less, or 45 kGy or less. Among these, 45 kGy or less is preferred from the viewpoint of preventing excessive yellowing of the porous tube.

[0107] <5. Various modifications can be made to the embodiments described above.> Various modifications can be made to the embodiments described above. For example, one or more of the following modifications can be selected to modify the embodiments described above.

[0108] In the embodiments described above, a configuration was described in which the access port 92 is not exposed toward the lumen of the artificial blood vessel 91. However, the vascular access device 9 is not limited to this configuration. The access port 92 may be exposed toward the lumen of the artificial blood vessel 91.

[0109] In the above-described embodiment, the artificial blood vessel 91 was described as comprising a porous tube and a biodegradable material within the pores of the porous tube. However, this embodiment is not limited to this configuration. For example, the artificial blood vessel 91 may be formed from knitted fabric, nonwoven fabric, foam, etc. Examples of such materials include polytetrafluoroethylene, polyester, and polyurethane.

[0110] In the embodiments described above, the artificial blood vessel 91 was configured to include a curved portion 911a and a curved portion 911b. However, this embodiment is not limited to this configuration. For example, the artificial blood vessel 91 may include only the curved portion 911a of the curved portions 911a and 911b. Of course, the artificial blood vessel 91 may include further curved portions in addition to the curved portions 911a and 911b.

[0111] A configuration in which the length L of the access port 92 is greater than the width W of the access port 92 has been described. However, this embodiment is not limited to this configuration.

[0112] Although the above-described embodiment explains that the access port 92 includes projections 927a and 927b, the vascular access device 9 is not limited to this configuration. For example, the access port 92 may include only projection 927a of projections 927a and 927b. Of course, the access port 92 may also include further projections along with projections 927a and 927b. The further projections may include further access surfaces. On the other hand, as shown in Figures 2A, 2B, 2C, and 2D, the access port 92 may include recesses 928a and 928b instead of protrusions 927a and 927b. The description of the depth H2 and length L2 of recess 928a is omitted because it overlaps with the description of the height H1 and length L1 of protrusion 927a. Therefore, the description of the height H1 and length L1 of protrusion 927a can also be used as the description of the depth H2 and length L2 of recess 928a. Similarly, the description of the height H1 and length L1 of protrusion 927a can also be used as the description of the depth and length of recess 928b. Recess 928a includes access surface 923a. Recess 928b includes access surface 923b. As shown in Figures 3A and 3B, the access port 92 does not have to include projections 927a and 927b or recesses 928a and 928b. In the vascular access device 9 shown in Figures 3A and 3B, the access surface 923a is not inclined with respect to the length of the access port 92, but the access surface 923a is indicated by at least one of color and line. The access surface 923a may have a different color from the surrounding color. That is, the access surface 923a may have a first color and the surrounding area of ​​the access surface 923a may have a second color. The access surface 923a may be separated from its surroundings by a line. The line separating the access surface 923a from its surroundings may be, for example, circular (e.g., a perfect circle, an ellipse, etc.) or quadrilateral. The line separating the access surface 923a from its surroundings may have a different color from the access surface 923a and its surroundings. The access surface 923b is not inclined with respect to the longitudinal direction of the access port 92, but the access surface 923b is indicated by at least one of color and lines. The access surface 923b may have a different color from the surrounding color. The access surface 923b may be separated from the surroundings by lines.

[0113] In the above-described embodiment, a configuration was described in which the access port 92 includes a main portion 921 and a surrounding portion 926. However, this embodiment is not limited to this configuration. For example, the access port 92 may include only the main portion 921 of the main portion 921 and the surrounding portion 926.

[0114] In the above-described embodiment, a configuration was explained in which an artery and a vein are connected by a vascular access device 9. However, the configuration is not limited to this. For example, veins may be connected to each other by the vascular access device 9. In this case, as a procedure for implanting the vascular access device 9, for example, an incision may be made in the skin 12 of the living body (for example, the skin of a human arm), the veins may be connected to each other by the artificial blood vessel 91 of the vascular access device 9, and then the vascular access device 9 may be sutured in such a manner that at least the access surface 923a and the access surface 923b are exposed from the skin 12. If the living body has an arteriovenous fistula, it is preferable to connect the veins to each other with the vascular access device 9 downstream of the anastomosis (for example, the anastomosis between an artery and a vein in an autologous arteriovenous fistula, or the anastomosis between an artificial blood vessel and a vein in an artificial arteriovenous fistula). [Explanation of symbols]

[0115] 9... Vascular access device, 91... Artificial blood vessel, 92... Access port, 921... Main part, 926... Peripheral part, 12... Skin, 911a... Curved part, 911b... Curved part, 912... Upstream part, 913... Downstream part, 916a... Upward part, 916b... Upward part, 917a... Downward part, 917b... Downward part, 923a... Access surface, 923b... Access surface, 922... Upper surface of main part, 927a... Projection, 927b... Projection, 928a... Recess, 928b... Recess, 30a... Upper end of access surface, 30b... Upper end of access surface, 31a... Lower end of access surface, 31b... Lower end of access surface, D1... Longitudinal direction, D11... First direction, D12... Second direction

Claims

1. Artificial blood vessels and The artificial blood vessel includes an access port protruding radially from the artificial blood vessel, The artificial blood vessel includes a curved portion adjacent to the access port that curves convexly toward the access port, Vascular access device.

2. The vascular access device according to claim 1, wherein the lengthwise dimension of the access port is greater than the widthwise dimension of the access port, and the lengthwise direction is parallel to the longitudinal direction of the artificial blood vessel.

3. The access port includes an access surface for being punctured with a needle, The access surface is inclined with respect to the longitudinal direction of the access port. The vascular access device according to claim 2.

4. The curved portion includes a first portion that approaches the upper end of the access surface in the height direction of the access port as it advances in the first longitudinal direction of the artificial blood vessel, and a second portion that moves away from the upper end of the access surface in the height direction of the access port as it advances in the first direction. The lower end of the access surface is downstream of the first part in the first direction, At least one virtual perpendicular line extending from the virtual plane including the height and length directions of the access port, and intersecting the access plane perpendicularly, passes through at least one of the center points of the inner diameter of the first part. The vascular access device according to claim 3.

5. The vascular access device according to claim 1, wherein the access port includes a projection that includes an access surface for being punctured with a needle.

6. The vascular access device according to claim 1, wherein the access port includes a recess that includes an access surface for being punctured with a needle.

7. The access port includes an access surface for being punctured with a needle, The access surface is indicated by at least one of color and lines. The vascular access device according to claim 1.

8. The vascular access device according to claim 1, wherein the access port includes an elastomer.

Images