Access port and vascular access device

Abstract

The purpose of the present invention is to provide an access port capable of suppressing or reducing the occurrence of coring. Another purpose of the present invention is to provide a vascular access device capable of the same. This access port (92) includes a vascular access part (921) and a peripheral part (926) that surrounds the periphery of the vascular access part (921). The tensile elastic modulus of the vascular access part (921) is greater than the tensile elastic modulus of the peripheral part (926). Meanwhile, a vascular access device (9) includes the access port (92) and a vascular prosthesis (91).

Description

Access ports and vascular access devices

[0001] The present invention relates to an access port and a vascular access device.

[0002] Hemodialysis is typically performed three times a week, and needles are inserted each time, so it is desirable to avoid or reduce the pain of needle insertion.

[0003] An example of a device that can avoid or reduce the pain of needle puncture is the columnar access port described in Patent Document 1. This access port includes a solid central portion extending along the axis of the columnar shape and a tubular peripheral portion surrounding the central portion. With this access port, the peripheral portion is harder than the central portion through which the needle is inserted, preventing the needle from being inserted at an angle.

[0004] However, when a needle is inserted into the rubber stopper of a vial, coring can occur (see Non-Patent Document 1). That is, the rubber stopper can be scraped off by the needle.

[0005] Patent No. 4815024

[0006] Chotikawanich T, Kammee T, Khantee S. The impact of needle size and angle on rubber coring after multiple puncturing of multi-dose propofol vial rubber stoppers. Heliyon. 2022 May 6;8(5):e09389. doi: 10.1016 / j.heliyon.2022.e09389. PMID: 35592659; PMCID: PMC9111999.

[0007] Coring can occur not only when the needle penetrates the rubber stopper of a vial, but also when the needle penetrates the access port.

[0008] An object of the present invention is to provide an access port that can suppress or reduce the occurrence of coring, and also to provide a vascular access device that can do so.

[0009] To solve this problem, the access port of the present invention has the following configuration [1]: [1] An access port including a vascular access portion including a first surface to be pierced with a needle and a second surface from which the needle protrudes, and a peripheral portion surrounding the periphery of the vascular access portion, wherein the vascular access portion contains an elastomer, and the tensile modulus of the vascular access portion is greater than the tensile modulus of the peripheral portion.

[0010] According to [1], since the vascular access portion contains an elastomer, when the needle is inserted into or removed from the vascular access portion, the hole made by the needle can be closed.

[0011] Furthermore, because the tensile modulus of the vascular access portion is greater than that of the surrounding portion, i.e., because the tensile modulus of the surrounding portion is smaller than that of the vascular access portion, the frequency of occurrence of elastomer pieces (hereinafter sometimes referred to as "rubber pieces," "cores," or "foreign matter") that may be generated when the vascular access portion is scraped off when a needle is inserted into the vascular access portion can be reduced. This is explained below. If the tensile modulus of the surrounding portion were greater than that of the vascular access portion, the surrounding portion would hinder the expansion of the vascular access portion in response to the insertion of a needle. In contrast, with the access port of [1], the tensile modulus of the surrounding portion is smaller than that of the vascular access portion, so the surrounding portion does not excessively hinder the expansion of the vascular access portion, and therefore the vascular access portion can expand in response to the insertion of a needle. As a result, the pressure applied by the vascular access portion to the needle can be reduced, reducing the frequency of cores. Therefore, the occurrence of coring can be suppressed or reduced.

[0012] The access port of the present invention preferably has the following configurations [2] to [5]. [2] The access port according to [1], wherein the tensile modulus of the vascular access portion is 250 kPa or more. [3] The access port according to [1] or [2], wherein the surrounding portion is porous. [4] The access port according to any of [1] to [3], wherein the surrounding portion contains a polyurethane-based thermoplastic elastomer. [5] The access port according to any of [1] to [4], wherein the surrounding portion includes a first layer and a second layer provided between the first layer and the vascular access portion, and the first layer is porous. [6] The access port according to any of [1] to [5], wherein the difference between the tensile modulus of the vascular access portion and the tensile modulus of the surrounding portion (i.e., the tensile modulus of the vascular access portion - the tensile modulus of the surrounding portion) is 50 kPa or more or 200 kPa or more. [7] The access port according to any one of [1] to [6], wherein the tensile modulus of elasticity of the vascular access portion is 300 kPa or more. [8] The access port according to any one of [1] to [7], wherein the tensile modulus of elasticity of the vascular access portion is 1500 kPa or less or 1000 kPa or less. [9] The access port according to any one of [1] to [8], wherein the peripheral portion covers at least a part of the surface connecting the first surface and the second surface of the vascular access portion.

[10] The access port according to any one of [1] to [9], wherein the peripheral portion covers the entire surface connecting the first surface and the second surface of the vascular access portion.

[0013] On the other hand, the vascular access device of the present invention has the configuration of

[11] below. The vascular access device of the present invention preferably has the configuration of

[12] below.

[11] A vascular access device comprising: an access port according to any one of [1] to

[10] ; and an artificial blood vessel, wherein the second surface of the access port faces the artificial blood vessel.

[12] The vascular access device according to

[11] , wherein the access port extends laterally from the outer surface of the artificial blood vessel.

[0014] According to the present invention, it is possible to provide an access port and a vascular access device that can suppress or reduce the occurrence of coring.

[0015] 1A , 2A , 2B, 2C, 2D, 2E, 2F, 2G, 2G, 2H ... 3A is a schematic cross-sectional view of a vascular access device and its surroundings when the vascular access device according to a modification of this embodiment is placed in a living body. 3B is a schematic view of the vascular access device and its surroundings when viewed in the direction of arrow IIIB shown in Fig. 3A. 3C is a schematic cross-sectional view of the vascular access device and its surroundings when cut along the IIIC cutting line shown in Fig. 3A. 3D is a schematic cross-sectional view of a vascular access device according to a further modification and its surroundings when cut along the IIIC cutting line shown in Fig. 3A.

[0016] Hereinafter, embodiments of the present invention will be described in detail.

[0017] 1A, 1B, and 1C, the vascular access device 9 of this embodiment includes an artificial blood vessel 91 and an access port 92 protruding from the artificial blood vessel 91. The artificial blood vessel 91 and the access port 92 can be joined by any method. For example, they may be sewn together, joined with an adhesive, welded with a solvent, or welded with heat. Because the access port 92 is joined to the artificial blood vessel 91, the effort of joining them can be eliminated when placing the vascular access device 9.

[0018] 1.1 Access Port The access port 92 extends in a columnar shape from the outer surface (hereinafter sometimes referred to as the "outer surface") of the artificial blood vessel 91 to the side of the artificial blood vessel 91. The angle α formed between the access port 92 and the artificial blood vessel 91 may be, for example, 10 degrees or more, 30 degrees or more, 45 degrees or more, or 60 degrees or more. The angle α may be, for example, 90 degrees or less.

[0019] The access port 92 has a columnar shape. Although the figures show a cylindrical access port 92, the shape of the access port 92 may be, for example, a square columnar shape or a pentagonal columnar shape. In other words, the access port 92 may have a rectangular columnar shape.

[0020] The height H of the access port 92 may be 3 mm or more, or 5 mm or more, based on the outer surface of the artificial blood vessel 91. The height H of the access port 92 may be 25 mm or less, or 20 mm or less.

[0021] The length L of the access port 92 may be 3 mm or more, or 5 mm or more. The length L of the access port 92 may be 150 mm or less, or 120 mm or less. Here, the length L of the access port 92 refers to the maximum dimension of the access port 92 in the longitudinal direction of the artificial blood vessel 91.

[0022] The width W of the access port 92 may be 4 mm or more, or 5 mm or more. The width of the access port 92 may be 15 mm or less, or 12 mm or less. Here, the width W of the access port 92 refers to the maximum dimension of the access port 92 in the thickness direction of the artificial blood vessel 91. The width W of the access port 92 may be larger, smaller, or the same as the thickness of the artificial blood vessel 91.

[0023] The number of access ports 92 in the vascular access device 9 is one or more, and may be two or more. Of these, one access port 92 is preferred. Note that the vascular access device 9 can be cut as needed to adjust the length before placement, and in this paragraph, the number of access ports 92 refers to the number of access ports 92 before cutting.

[0024] The access port 92 is made of an elastomer. Because the access port 92 is made of an elastomer, when a needle is inserted into or removed from the vascular access portion 921 of the access port 92, the hole made by the needle can be closed.

[0025] The access port 92 includes a vascular access portion 921 and a peripheral portion 926 that surrounds the periphery of the vascular access portion 921. The vascular access portion 921 and the peripheral portion 926 may be joined together, for example, by stitching, bonding with an adhesive, welding with a solvent, or welding with heat. The vascular access portion 921 may also be fitted to the peripheral portion 926 without adhesive and / or thread.

[0026] The vascular access portion 921 is cylindrical. Although these figures show a cylindrical vascular access portion 921, the shape of the vascular access portion 921 may be, for example, a square prism or a pentagonal prism. In other words, the shape of the vascular access portion 921 may be a prismatic prism.

[0027] The vascular access portion 921 includes a first surface 923 for being punctured with a needle and a second surface 924 from which the needle protrudes. The second surface 924 faces the artificial blood vessel 91. The second surface 924 is positioned closer to the artificial blood vessel 91 than the first surface 923.

[0028] The area of ​​the first surface 923 is, for example, 10 mm ２ It may be 15 mm or more. ２ The area of ​​the first surface 923 may be, for example, 20 mm ２ It may be 30 mm or more. ２ The area of ​​the first surface 923 may be, for example, 180 mm ２ It may be less than 120 mm ２ It may be the following:

[0029] The vascular access portion 921 is formed of an elastomer. That is, the vascular access portion 921 contains an elastomer. Because the vascular access portion 921 contains an elastomer, when a needle is inserted into or removed from the vascular access portion 921, the hole made by the needle can be closed. A thermoplastic elastomer is preferable as the elastomer. When the vascular access portion 921 contains a thermoplastic elastomer, the vascular access portion 921 is easily manufactured. 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 preferable. Examples of styrene-based thermoplastic elastomers include styrene-diene-styrene block copolymers such as styrene-butadiene-styrene block copolymers (SBS) and styrene-isoprene-styrene block copolymers (SIS). Examples of styrene-based thermoplastic elastomers include hydrogenated styrene-diene-styrene block copolymers. The vascular access portion 921 may further contain components other than the elastomer (for example, additives).

[0030] The tensile modulus of the vascular access portion 921 is greater than that of the surrounding portion 926. This reduces the frequency of elastomer fragments (i.e., cores) that may be formed when the vascular access portion 921 is scraped off when a needle is inserted into the vascular access portion 921. This is explained below. If the tensile modulus of the surrounding portion 926 were greater than that of the vascular access portion 921, the surrounding portion 926 would prevent the vascular access portion 921 from expanding in response to the insertion of a needle. In contrast, with the access port 92, the tensile modulus of the surrounding portion 926 is less than that of the vascular access portion 921. This prevents the surrounding portion 926 from excessively impeding the expansion of the vascular access portion 921, allowing the vascular access portion 921 to expand in response to the insertion of a needle. As a result, the pressure applied by the vascular access portion 921 to the needle can be reduced, reducing the frequency of core formation. Therefore, the occurrence of coring can be suppressed or reduced. Furthermore, because the tensile modulus of the surrounding portion 926 is smaller than that of the vascular access portion 921, it is easier to thread a thread through the surrounding portion 926 than through the vascular access portion 921. Therefore, when suturing the access port 92 to the skin 12, the suturing may be easier. The difference between the tensile modulus of the vascular access portion 921 and the tensile modulus of the surrounding portion 926 (i.e., the tensile modulus of the vascular access portion 921 minus the tensile modulus of the surrounding portion 926) may be, for example, 50 kPa or more, or 200 kPa or more. Here, the tensile modulus is a value measured by the method described in the Examples.

[0031] The tensile modulus of the vascular access portion 921 is preferably 250 kPa or more. If the modulus is 250 kPa or more, when a needle is inserted into or removed from the vascular access portion 921, the hole made by the needle can be effectively closed. In other words, the hemostatic properties are excellent. The tensile modulus of the vascular access portion 921 is more preferably 300 kPa or more. On the other hand, the tensile modulus of the vascular access portion 921 may be, for example, 1500 kPa or less, or 1000 kPa or less.

[0032] The peripheral portion 926 covers the entire surface (hereinafter, sometimes referred to as the "side surface") connecting the first surface 923 and the second surface 924 of the vascular access portion 921. In other words, the peripheral portion 926 covers all of the side surfaces of the vascular access portion 921. In these figures, the peripheral portion 926 covers all surfaces (i.e., surfaces) of the vascular access portion 921 except for the first surface 923 and the second surface 924. Although a tubular peripheral portion 926 is shown in these figures, the shape of the peripheral portion 926 may also be, for example, a rectangular cylindrical shape. When the vascular access portion 921 is rectangular prism-shaped, the peripheral portion 926 is preferably rectangular tubular. In other words, the peripheral portion 926 can be cylindrical (e.g., tubular, rectangular, etc.).

[0033] The thickness of the surrounding portion 926 may be, for example, 0.5 mm or more, or 1 mm or more. The thickness of the surrounding portion 926 may be 3 mm or less, or 2 mm or less. The surrounding portion 926 may have a single layer configuration.

[0034] The perimeter 926 is preferably porous, which allows tissue to penetrate the perimeter 926 and thus somewhat secure the access port 92 to the body.

[0035] The surrounding portion 926 is formed of an elastomer. That is, the surrounding portion 926 contains an elastomer. A thermoplastic elastomer is preferable as the elastomer. When the surrounding portion 926 contains a thermoplastic elastomer, the surrounding portion 926 is easily manufactured. 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 polyurethanes, are preferable. Examples of polyurethane-based thermoplastic elastomers include Pellethane (registered trademark), ChronoFlex (registered trademark), ChronoTane (registered trademark), and HydroTane (registered trademark). These are preferable because medical-grade products are commercially available. The surrounding portion 926 may further contain components other than the elastomer (for example, additives).

[0036] 1.2 Artificial Blood Vessel The artificial blood vessel 91 includes an inner lumen surface (hereinafter sometimes referred to as the "inner surface") and an outer surface. Both ends of the artificial blood vessel 91 are open.

[0037] The artificial blood vessel 91 may be, for example, a straight type, a tapered type, or a short tapered type.

[0038] The length of the artificial blood vessel 91 may be, for example, 50 mm or more, or 100 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 of the vascular access device 9 can be cut as necessary to adjust its length before placement, and in this paragraph, the length of the artificial blood vessel 91 refers to the length of the artificial blood vessel 91 before cutting.

[0039] The inner diameter of the artificial blood vessel 91 may be, for example, 4 mm or more, or 5 mm or more. The inner diameter of the artificial blood vessel 91 may be, for example, 15 mm or less, or 12 mm or less. Note that when the artificial blood vessel 91 is, for example, a tapered type or a short taper type, the inner diameter in this specification means the maximum inner diameter.

[0040] The artificial blood vessel 91 preferably includes a tube made of an elastomer (hereinafter, sometimes referred to as an "elastomeric tube"). The elastomer tube may be, for example, porous or non-porous. A thermoplastic elastomer is preferred as the elastomer. When the elastomer tube is made of a thermoplastic elastomer, i.e., when the elastomer tube contains a thermoplastic elastomer, the elastomer tube is easy to fabricate. 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. The elastomer tube may be coated with some substance, such as gelatin.

[0041] 1.3 Placement The vascular access device 9 is placed in a manner in which at least a portion of the first surface 923 of the vascular access portion 921 is exposed from the skin 12. By placing the vascular access device 9 in this manner, pain from puncture can be avoided or reduced. Note that these figures show a manner in which the entire first surface 923 is exposed from the skin 12.

[0042] To place the vascular access device 9, an artery and a vein can be connected together using 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 placement procedure for the vascular access device 9 can include, for example, incising the skin 12 of a living body (e.g., the skin of a human arm), connecting the artery and the vein with the vascular access device 9, and then sewn up the vascular access device 9 so that at least a portion of the first surface 923 of the vascular access portion 921 is exposed from the skin 12. Examples of veins include the cephalic vein, basilic vein, and saphenous vein. The blood vessel (specifically, the artery or vein) and the artificial blood vessel 91 can be sewn up with sutures. In this case, the artificial blood vessel 91 of the vascular access device 9 may be placed in a loop shape or a straight shape, for example.

[0043] The length of the placed artificial blood vessel 91 may be, for example, 50 mm or more, or 100 mm or more. The length of the placed artificial blood vessel 91 may be 600 mm or less, or 500 mm or less.

[0044] 2. Various modifications can be made to the above-described embodiment. Various modifications can be made to the above-described embodiment. For example, one or more of the following modifications can be selected and made to the above-described embodiment.

[0045] In the above-described embodiment, a configuration in which an artery and a vein are connected by the vascular access device 9 has been described. However, the present invention is not limited to this configuration. For example, veins may be connected to each other by the vascular access device 9 (not shown). In this case, the placement procedure of the vascular access device 9 may include, for example, incising the skin 12 of a living body (e.g., the skin of a human arm), connecting the veins to each other with the artificial blood vessel 91 of the vascular access device 9, and then suturing the vascular access device 9 so that at least a portion of the first surface 923 of the vascular access portion 921 is exposed from the skin 12. When the living body has an internal shunt, it is preferable to connect the veins to each other with the vascular access device 9 downstream of the anastomosis (e.g., the anastomosis between an artery and a vein in an autologous intravascular shunt, the anastomosis between an artificial blood vessel and a vein in an artificial intravascular shunt, etc.).

[0046] In the above-described embodiment, a configuration has been described in which the access port 92 extends laterally from the outer surface of the artificial blood vessel 91. In this configuration, the second surface 924 of 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. As shown in FIG. 1D , at least the second surface 924 of the access port 92 may be exposed toward the lumen of the artificial blood vessel 91. In this case, at least the second surface 924 of the access port 92 may be exposed toward the lumen of the artificial blood vessel 91 from an opening formed in the artificial blood vessel 91. In this manner, with at least the second surface 924 of the access port 92 exposed toward the lumen of the artificial blood vessel 91, the second surface 924 may face the artificial blood vessel 91.

[0047] In the above-described embodiment, the peripheral portion 926 covers the entire side surface of the vascular access portion 921. However, the vascular access device 9 is not limited to this configuration. As shown in Fig. 1E, the peripheral portion 926 may cover only a portion of the side surface of the vascular access portion 921. In this figure, the side surface near the tip of the vascular access portion 921 is exposed.

[0048] In the above-described embodiment, the peripheral portion 926 has been described as having a single-layer structure. However, the vascular access device 9 is not limited to this structure. As shown in FIG. 1F , the peripheral portion 926 may have a multi-layer structure. The peripheral portion 926 of the vascular access device 9 shown in this figure includes a first layer 61 and a second layer 62. The first layer 61 may be porous. The second layer 62 is provided between the first layer 61 and the vascular access portion 921. The second layer 62 may be porous or non-porous.

[0049] In the above-described embodiment, the access port 92 extends in a columnar shape laterally from the artificial blood vessel 91. However, the vascular access device 9 is not limited to this configuration. The shape of the access port 92 can be modified as appropriate. This will be described below. The access port 92 may have a shape such as that shown in FIGS. 2A, 2B, and 2C. That is, the access port 92 may extend along the length of the artificial blood vessel 91 while increasing in height without separating from the artificial blood vessel 91. The access port 92 may have a shape such as that shown in FIGS. 3A, 3B, and 3C. That is, the access port 92 may extend along the length of the artificial blood vessel 91 at a constant height H without separating from the artificial blood vessel 91. The length L of the access port 92 in this example is as described in the above-described embodiment, but may also be, for example, 10 mm or more, or 25 mm or more. The length L of the access port 92 may be 200 mm or less, or 150 mm or less. In these figures (i.e., FIGS. 2A, 2B, 2C, 3A, 3B, and 3C), the width W of the access port 92 is generally constant along the height H of the access port 92. However, the width W of the access port 92 is not limited to this. For example, as shown in FIG. 3D, the width W of the access port 92 may increase along the height H of the access port 92. This allows the area of ​​the first surface 923 to be increased compared to when the width W of the access port 92 is constant along the height H of the access port 92.

[0050] In the above embodiment, the access port 92 is used in a living body together with the artificial blood vessel 91. However, the access port 92 may be used in a living body independently of the artificial blood vessel 91. In other words, the access port 92 may be used in a living body without the artificial blood vessel 91.

[0051] In the above-described embodiment, the peripheral portion 926 is porous. However, the vascular access device 9 is not limited to this configuration. The peripheral portion 926 may be non-porous.

[0052] In the above-described embodiment, the surrounding portion 926 is formed from an elastomer. However, the vascular access device 9 is not limited to this configuration. The surrounding portion 926 may be formed from a material other than an elastomer.

[0053] The present invention will be described in more detail below with reference to examples and comparative examples. Unless otherwise specified, "parts" means "parts by mass" and "%" means "% by mass".

[0054] <1. Evaluation Method> <1.1. Measurement of Tensile Modulus> A test piece 50 mm long and 5 mm wide was cut out from an elastomer sheet 3 mm thick. A tensile test was carried out using an Autograph AGS-X 1kN manufactured by Shimadzu Corporation, with a gauge length of 30 mm and a tensile speed of 150 mm / min. The cross-sectional area A (unit: m ２ The tensile modulus was calculated using the following formula: A (m ２ ) = 3 / 1000 × 5 / 1000 Tensile modulus (kPa) = (N5 (N) - N1 (N)) / A (m ２ ) / 0.04 "N5(N)" means that a value of N units is substituted for N5 in this formula. "N1(N)" means that a value of N units is substituted for N1 in this formula. "A(m ２ ) is m in A of this formula ２ This means that the unit value is substituted.

[0055] <1.2. Puncture Test> <1.2.1. Examples 1 to 3> A 50 mL sample bottle was pre-washed with distilled water and then filled with 40 mL of distilled water. An elastomer sheet was fixed onto the mouth of the sample bottle containing 40 mL of distilled water, and the elastomer sheet was repeatedly punctured with a 16 G syringe at an angle of 45° to the top surface of the elastomer sheet. When the number of punctures reached 300, 800, and 1000, the amount of water leakage and coring measurements, as described below, were performed.

[0056] 1.2.2. Comparative Example 1 Puncture was performed in the same manner as in Example 1, except that instead of simply fixing an elastomer sheet over the mouth of a sample bottle containing 40 mL of distilled water, an elastomer sheet fitted in a metal frame (specifically, a metal frame into which a 50 mm square, 3 mm thick elastomer sheet could be snugly fitted) was fixed over the mouth of the sample bottle containing 40 mL of distilled water.

[0057] <1.3. Measurement of Water Leakage Amount> An elastomer sheet was fixed to the top surface of a cylindrical container with a diameter of 30 mm. Water was pumped into the container, and a water pressure of 16.0±0.3 kPa (120±2 mmHg) was applied to a circuit capable of applying water pressure to the elastomer sheet fixed to the top surface of the container using the water. The amount of water leakage from the surface of the elastomer sheet for 60 seconds after the puncture test was measured. A rating of "Good" was given when the amount of water leakage was less than 1 mL / min after 300, 800, and 1000 punctures. A rating of "Poor" was given when the amount of water leakage was 1 mL / min or more after 300 punctures.

[0058] <1.4. Coring Measurement> Coring was measured in accordance with the light-shielding particle counting method in the Japanese Pharmacopoeia, "6.07 Test Method for Insoluble Particles in Injectables." Specifically, the number of particles in the sample (specifically, distilled water in a sample bottle that had been obliquely punctured 300, 800, or 1000 times) was measured using a liquid particle counter KL-05 manufactured by Rion Co., Ltd. under the following conditions: flow rate: 25 mL / min, waste flow rate: 100 mL / min, measurement volume: 5.0 mL, number of empty measurements: 1, and number of measurements: 3. After puncturing 300, 800, and 1000 times, a rating of "Good" was given when the number of particles 10 μm or larger was 25 or less and the number of particles 25 μm or larger was 10 or less. After puncturing 300 times, a rating of "Good" was given when the number of particles 10 μm or larger was more than 25 and the number of particles 25 μm or larger was 10 or less. After puncturing 300 times, a rating of "Good" was given when the number of particles 10 μm or larger was more than 25 and the number of particles 25 μm or larger was 10 or less. When the number of punctures was 300 and the number of particles of 10 μm or more exceeded 25 and the number of particles of 25 μm or more exceeded 10, the result was judged as x.

[0059] 2. Preparation of Elastomer Sheets 2.1. Example 1 and Comparative Example 1 A 3 mm thick elastomer sheet was prepared by thermal compression molding a styrene-isoprene-styrene elastomer D1161 manufactured by KRATON using a hot press.

[0060] 2.2. Example 2 An elastomer sheet having a thickness of 3 mm was prepared in the same manner as in Example 1, except that styrene-isoprene-styrene elastomer D1163 manufactured by KRATON was used instead of D1161.

[0061] 2.3. Example 3 A commercially available isoprene rubber sheet having a thickness of 3 mm was used as the elastomer sheet.

[0062] <3. Results> The table summarizing the results is shown below.

[0063] It is clear that the coring results after the puncture test without a metal frame in Examples 1 to 3 suggest the coring results after the puncture test when the elastomer sheet is fitted into a frame having a tensile modulus smaller than that of the elastomer sheet. Therefore, the coring results in Examples 1 to 3 support the coring reduction effect of the invention according to the "Summary of the Invention" described above (specifically, the effect of suppressing or reducing the occurrence of coring).

[0064] 9... Vascular access device, 91... Artificial blood vessel, 92... Access port, 921... Vascular access portion, 926... Surrounding portion, 61... First layer, 61... Second layer, 12... Skin

Claims

1. An access port comprising: a vascular access portion including a first surface for being pierced with a needle and a second surface for the needle to protrude from; and a peripheral portion surrounding the periphery of the vascular access portion, wherein the vascular access portion contains an elastomer, and the tensile modulus of the vascular access portion is greater than the tensile modulus of the peripheral portion.

2. The access port according to claim 1, wherein the tensile modulus of elasticity of the vascular access portion is 250 kPa or more.

3. The access port of claim 1, wherein said periphery is porous.

4. The access port of claim 3, wherein said surround comprises a polyurethane-based thermoplastic elastomer.

5. The access port of claim 1, wherein the peripheral portion includes a first layer and a second layer disposed between the first layer and the vascular access portion, and the first layer is porous.

6. A vascular access device comprising: an access port according to any one of claims 1 to 5; and an artificial blood vessel, wherein the second surface of the access port faces the artificial blood vessel.

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