Drug injection tool and drug injection assembly

Abstract

To provide a drug injection tool which reduces burden on an operator and which can restrain a drug such as a liquid embolus substance from being fixed to a hub lumen, and a drug injection assembly.SOLUTION: In a drug injection tool 1, a catheter 2, which comprises a catheter body 21 having a catheter lumen 21a and a hub 22 having a hub lumen 224 joined to a base end side B of the catheter body 21 and communicating with the catheter lumen 21a, is connected to a tip side A, and a drug stored in a syringe 31 is supplied from the base end side B. The drug supplied from the syringe 31 is injected into the living body via the catheter lumen 21a without the intermediary of the hub lumen 224.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a drug injection device and a drug injection assembly. [Background technology]

[0002] In recent years, an attachment has been proposed that provides a fluid-tight connection between a syringe and a catheter (see, for example, Patent Document 1).

[0003] Liquid embolic agents, such as N-butyl cyanoacrylate (NBCA), have been used in endoscopic sclerotherapy for esophageal and gastric varices. Recently, a liquid mixture of NBCA and the solvent Lipiodol® (hereinafter referred to as the NBCA mixture) has also been used to treat bleeding disorders and arteriovenous malformations by intravascular injection. When injected through a catheter, this NBCA mixture instantly polymerizes upon contact with blood, forming a solid substance that occludes the vascular lumen. However, because the viscosity of the NBCA mixture varies with temperature, controlling the timing of polymerization is extremely difficult, resulting in central occlusion or leakage into the venous system. Furthermore, if the catheter is not retracted quickly, the NBCA mixture may adhere to the catheter, preventing effective embolization and potentially rendering the catheter impossible to remove.

[0004] The attachment described in Patent Document 1 comprises a first component side main body portion having a tapered base mounting portion at its rear end into which the tip of the syringe is inserted, a first component side connecting portion (threaded portion) provided on the first component side main body portion and threadedly engaging with a male thread provided on a catheter hub joined to the rear end of the catheter, and a tapered connecting portion provided on the first component side main body portion and inserted partway into the tapered hub lumen, and the entire attachment is formed from the same material (metal or resin). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-220936 Summary of the Invention [Problem to be solved by the invention]

[0006] The inner layer of catheters used to inject the NBCA mixture into living bodies is generally made of a material to which the NBCA mixture does not easily adhere (e.g., fluororesin, polyolefin resin, silicone resin, etc.). On the other hand, the hub is generally made of a material that is easily adhesive (e.g., ABS, polyamide, etc.) because it is glued to the outer layer of the catheter. These adhesive materials are also materials to which the NBCA mixture easily adheres. For this reason, in medical settings, precise temperature control and ingenious equipment (e.g., using a syringe needle long enough to reach the base end of the catheter) are employed to prevent the NBCA mixture from adhering to the hub lumen, which places a burden on surgeons when injecting the NBCA mixture into living bodies.

[0007] Furthermore, even if the attachment is made of a material that is resistant to adhesion of the NBCA mixture, the tip of the connection part of the attachment does not reach the catheter lumen, so there is a risk that the NBCA mixture will adhere to the hub lumen when injected into the living body.

[0008] An object of the present invention is to provide a drug injection device and a drug injection assembly that can reduce the burden on the operator and prevent drugs such as liquid embolic substances from adhering to the hub lumen. [Means for solving the problem]

[0009] [1] A drug injection device in which a catheter including a catheter body having a catheter lumen and a hub having a hub lumen joined to the base end side of the catheter body and communicating with the catheter lumen is connected to the distal end side, and a drug contained in a syringe is supplied from the base end side, A drug injection device that injects the drug supplied from the syringe into a living body via the catheter lumen without passing through the hub lumen. [2] A tube having an injection tool lumen with both axial ends open, The drug injection device described in [1] above, wherein when the tip side of the tube is inserted into the hub lumen and connected to the catheter, the injection device lumen is directly fluidly connected to the catheter lumen. [3] The drug injection device described in [2] above, wherein when the tip of the tube is inserted into the hub lumen and connected to the catheter, the drug discharge port opening at the tip of the injection device lumen is positioned at a position where it enters the catheter lumen. [4] The tube comprises a tapered first element and a second element provided at the distal end side of the first element, having the medicine ejection port at the distal end side, and having a constant outer diameter over the entire axial length; The pharmaceutical injection device according to [3] above, wherein the first element is formed so that the inner and outer diameters and the wall thickness become smaller stepwise or continuously from the base end side to the tip end side. [5] The drug injection device according to [4], wherein at least the inner surface of the tube is made of a material to which the drug does not easily adhere even if the drug adheres. [6] The agent is a liquid containing a cyanoacrylate adhesive; The drug injection device according to [5] above, wherein at least the inner surface of the tube is formed from a fluorine-based resin, an olefin-based resin, or a silicone-based resin. [7] The syringe further includes a connector portion formed separately from the tube, joined to the tube, and connected to the syringe; The drug injection device according to [6], wherein the distal end portion of the tube is inserted into the catheter lumen when the catheter is connected to the distal end of the tube. [8] The catheter body is a catheter body of a microcatheter, The drug injection device according to [7], wherein the distal end portion of the tube inserted into the catheter lumen has an outer diameter equal to or smaller than the maximum inner diameter of the microcatheter. [9] Further comprising the syringe, The drug injection device according to any one of [1] to [8], wherein the syringe is provided integrally with the tube at the base end side of the tube with the drug contained therein in advance.

[10] The drug injection device according to any one of [1] to [9] above, A drug injection assembly comprising the catheter.

[11] A drug injection assembly as described in

[10] , wherein the tip side of the hub has a fitting hole through which the base end portion of the catheter body fits into the inner surface of the hub. [Effects of the Invention]

[0010] According to the present invention, it is possible to reduce the burden on the operator and to prevent a drug such as a liquid embolic substance from adhering to the lumen of the hub. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 shows an example of a drug injection assembly according to a first embodiment of the present invention, where (a) is an exploded front view and (b) is a front view of the assembled state. [Figure 2] FIG. 2 is a longitudinal cross-sectional view showing an example of a catheter. [Figure 3] FIG. 3 shows the pharmaceutical injection device shown in FIG. 1, where (a) is a front view, (b) is a partial cross-sectional view of part D in (a), and (c) is a partial cross-sectional view showing a modified example of (b). [Figure 4] FIG. 4 is a partial cross-sectional view of part C in FIG. [Figure 5] FIG. 5 is a perspective view showing an example of the appearance of a pharmaceutical injection device according to a second embodiment of the present invention. [Figure 6] FIG. 6 is a front view of the pharmaceutical injection device shown in FIG. [Figure 7] FIG. 7 is a plan view of the pharmaceutical injection device shown in FIG. [Figure 8] FIG. 8 is a right side view of the pharmaceutical injection device shown in FIG. [Figure 9] FIG. 9 is a left side view of the pharmaceutical injection device shown in FIG. [Figure 10] FIG. 10 is a cross-sectional view taken along line EE in FIG. [Figure 11] FIG. 11 is a front view of the tube portion shown in FIG. [Figure 12] FIG. 12 is a front view of the pharmaceutical injection device of Modification 1. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, components having substantially the same functions are designated by the same reference numerals, and redundant description thereof will be omitted.

[0013] [First embodiment] 1 shows an example of a drug injection assembly according to a first embodiment of the present invention, with (a) being an exploded front view and (b) being a front view of the assembled state. In this specification, the side inserted into the living body is referred to as the distal side A, and the side operated by the surgeon is referred to as the proximal side B.

[0014] (Drug injection assembly configuration) As shown in FIG. 1(a), this drug injection assembly 100 comprises a catheter 2 having a hub 22 joined to the base end side B of a catheter main body 21, a drug injection device 1 connected to the base end side B of the catheter 2, and a syringe 3 connected to the base end side B of the drug injection device 1. When using the drug injection assembly 100, as shown in FIG. 1(b), the drug injection device 1 is connected to the base end side B of the catheter 2, and the syringe 3, in which a drug is stored in a syringe 31, is connected to the base end side B of the drug injection device 1. Details of how the catheter 2, drug injection device 1, and syringe 3 are connected will be described later.

[0015] Examples of the liquid embolic substance housed in the syringe 31 include a cyanoacrylate adhesive such as N-butyl-2-cyanoacrylate (NBCA) and an ethylene vinyl alcohol copolymer (EVOH). The NBCA mixture is injected into the living body through the catheter 2 and, upon contact with the blood, instantly polymerizes to form a solid substance that occludes the vascular lumen. For example, NBCA is typically diluted by mixing it with an oil-based contrast agent (e.g., Lipiodol®) to adjust the polymerization rate and achieve the desired viscosity. Because the viscosity of the NBCA mixture tends to decrease with heating (e.g., 52 mPa·s at 5°C, 18 mPa·s at 37°C), precise temperature control is also required. Therefore, in medical settings, precise temperature control and ingenious tools (for example, inserting a syringe needle long enough to reach the base end of the catheter via a closed connector (e.g., Shore Plug (registered trademark))) are used to prevent the NBCA mixture from adhering to the hub lumen. Furthermore, there is a risk that the tip of the syringe needle may damage the catheter lumen. These factors have placed a burden on the surgeon when injecting the NBCA mixture into a living body.

[0016] Therefore, in this embodiment, drug injection device 1, which has the functions of both an injection needle and a closed connector, is connected between catheter 2 and syringe 3, and the drug supplied from syringe 31 is injected into the living body via catheter lumen 21a (see FIG. 2) without passing through hub lumen 224 (see FIG. 2). In other words, the drug is introduced directly into catheter lumen 21a (see FIG. 2) via drug injection device 1. That is, injection device lumen 115 (see FIG. 3(a)) of drug injection device 1 is in direct fluid communication with catheter lumen 21a. This reduces the burden on the operator and prevents the drug from adhering to hub 22 of catheter 2.

[0017] (Syringe configuration) Syringe 3 is available in two types: one with a locking mechanism and one without. While Fig. 1 shows a type with a locking mechanism, a type without a locking mechanism can also be applied to pharmaceutical injection device 1. Syringe 3 shown in Fig. 1 includes syringe 31 that contains a pharmaceutical, finger flange 32 fixed to base end side B of syringe 31, plunger 33 that moves within syringe 31 to push out the pharmaceutical inside syringe 31, pressing portion 34 that is provided on base end side B of plunger 33 and receives a pushing force against plunger 33, threaded portion 35 as an example of a locking mechanism that threadably engages with threaded projection 223 provided on hub 22 of catheter 2, and a cylindrical tip 36 provided on tip end side A of syringe 31.

[0018] Thread 35a is formed on the inner surface of threaded portion 35. Thread 35a of threaded portion 35 threadably engages with threading projection 116 provided on base end side B of pharmaceutical injection device 1, thereby connecting syringe 3 to pharmaceutical injection device 1. Note that syringe 31 may be provided integrally with pharmaceutical injection device 1 without using threaded portion 35. In this case, syringe 31 may be pre-filled with the necessary pharmaceutical.

[0019] As shown in FIG. 3(a), which will be described later, when the cylindrical tip 36 is inserted into the base end side B of the injection device lumen 115 of the pharmaceutical injection device 1, the outer peripheral surface 36a of the cylindrical tip 36 comes into contact with the inner peripheral surface 115a that defines the lumen at the most base end side B of the injection device lumen 115 (see the two-dot chain line in FIG. 3(a)). Therefore, to ensure a liquid-tight seal between the outer peripheral surface 36a and the inner peripheral surface 115a of the cylindrical tip 36, the outer peripheral surface 36a and the inner peripheral surface 115a of the cylindrical tip 36 are formed in a tapered shape (e.g., a taper ratio of 6 / 100) that conforms to a predetermined standard (e.g., JIS T 3210: Sterilized Syringes). Note that the outer peripheral surface 36a of the cylindrical tip 36 does not have to conform to a predetermined standard as long as it has a shape that corresponds to the inner peripheral surface 115a.

[0020] (Catheter configuration) 2 is a longitudinal cross-sectional view showing an example of a catheter 2. The catheter 2 includes a catheter main body 21 having a catheter lumen 21a, a hub 22 joined to the outer peripheral surface of the base end side B of the catheter main body 21 and having a hub lumen 224 communicating with the catheter lumen 21a, and a strain relief 23 for alleviating stress on the base end side B of the catheter main body 21.

[0021] For example, a microcatheter with an inner diameter of 1 mm or less can be used as the catheter main body 21. Note that the microcatheter is not limited to the above size, and the catheter main body 21 is not limited to a microcatheter. Also, although the catheter main body 21 is illustrated in Figures 2 and 4 as having the same outer and inner diameters along the axial direction, the outer and inner diameters may widen toward the base end side B.

[0022] Hub 22 comprises hub tube 221 having hub lumen 224 with both axial ends open, a pair of wings 222A, 222B provided at opposing positions on the outer peripheral surface of hub tube 221 for changing the orientation of catheter body 21 around the axis, and a screw projection 223 provided on base end side B of hub tube 221 for screwing into thread 12a of screw portion 12 of drug injection device 1.

[0023] The inner circumferential surfaces that define the hub lumen 224 are an inner circumferential surface 224a on the base end side B and an inner circumferential surface 224b on the tip end side A. The inner circumferential surface 224a on the base end side B is tapered (taper ratio 6 / 100) to correspond to the intermediate segment 112 described below. Furthermore, the inner circumferential surface 224b on the tip end side A is formed with an inner diameter that is the same as the minimum diameter of the inner circumferential surface 224a and remains constant along the longitudinal direction to facilitate insertion of the tip end segment 113 of the pharmaceutical injection device 1.

[0024] A fitting hole 224c having a predetermined length (e.g., 5 to 10 mm) in the axial direction is formed on the distal end side A of the hub tube 221 for connection to the end portion on the proximal end side B of the catheter main body 21. The end portion on the proximal end side B of the catheter main body 21 is fitted into the fitting hole 224c and joined to the hub tube 221 by a known joining method (e.g., adhesive bonding, fusion bonding, etc.).

[0025] The hub 22 is formed integrally with the catheter body 21 from a material (such as ABS or polyamide) that is easily bonded to the outer circumferential surface of the catheter body 21 by a known molding method (such as injection molding or compression molding).

[0026] The strain relief 23 is a member for reinforcing the connection between the catheter body 21 and the hub 22, and is provided to cover the area including the connection, and has a conical shape tapering toward the distal end side A. This makes it possible to impart kink resistance to the catheter 2. The strain relief 23 is formed, for example, from a flexible or elastic material such as polyurethane resin or silicone resin.

[0027] Alternatively, the distal end side A of the hub tube 221 may be thinned, and the thinned distal end may be inserted into the catheter lumen 21a to join the catheter body 21 and the hub 22 together.

[0028] (Configuration of drug injection device) FIG. 3 shows an example of a drug injection device 1, where (a) is a front view, (b) is a partial cross-sectional view of portion D in (a), and (c) is a partial cross-sectional view showing a modified example of (b). FIG. 4 is a partial cross-sectional view of portion C in FIG. 1(b). As shown in FIG. 3(a), drug injection device 1 comprises an injector tube 11 having an injector lumen 115 with both axial ends open, a threaded portion 12 rotatably provided on the outer peripheral surface of injector tube 11, and a gripping portion 114 fixed to the outer peripheral surface of injector tube 11 and used to grip drug injection device 1. By providing threaded portion 12 rotatably relative to injector tube 11 and further providing gripping portion 114, it is possible to hold gripping portion 114 with one hand and rotate threaded portion 12 with the other. As a result, injector tube 11 can be inserted into hub lumen 224 of catheter 2 without rotating, and thread 12a of threaded portion 12 can be easily threaded onto threading protrusion 223. The injection tube 11 is an example of a tube.

[0029] The injection tool tube 11 is composed of a base end segment 111, an intermediate segment 112, and a tip end segment 113, arranged in this order from the base end side B. The intermediate segment 112 is an example of a first element. The tip end segment 113 is an example of a second element.

[0030] A screw projection 116 that screws onto the thread 35 a of the screw portion 35 of the syringe 3 is formed on the base end side B of the base end segment 111 .

[0031] When the injection tool tube 11 is inserted into the proximal side B of the hub lumen 224 of the catheter 2, the outer peripheral surface 112a of the intermediate segment 112 comes into contact entirely with the inner peripheral surface 224a that defines the lumen of the proximal side B of the hub lumen 224. Therefore, to ensure a liquid-tight seal between the outer peripheral surface 112a and the inner peripheral surface 224a of the intermediate segment 112, the outer peripheral surface 112a and the inner peripheral surface 224a of the intermediate segment 112 are formed in a tapered shape (e.g., taper ratio 6 / 100) that conforms to a predetermined standard (e.g., JIS T 3210: Sterilized Syringes). Note that the outer peripheral surface 112a of the intermediate segment 112 does not have to conform to a predetermined standard as long as it has a shape that corresponds to the inner peripheral surface 224a. Note that the taper angle of the outer peripheral surface 112a of the intermediate segment 112 may be greater than the taper angle of the inner peripheral surface 224a of the catheter 2.

[0032] The distal end side A of injection tool lumen 115 opens as drug discharge port 113a, and the proximal end side B opens as drug introduction port 111a. Taking into consideration drug injection resistance, injection tool lumen 115 is formed so that the inner diameter decreases stepwise or continuously from drug introduction port 111a at proximal end side B toward drug discharge port 113a at distal end side A. Specifically, inner circumferential surfaces 115a, 115b, 115c, and 115d are formed from proximal end side B toward distal end side A as inner circumferential surfaces that define injection tool lumen 115. As described above, inner circumferential surface 115a at the most proximal end side B is formed in a tapered shape (taper ratio 6 / 100) that tapers to correspond to nozzle 36 of syringe 3. Inner circumferential surface 115b is formed to have the same inner diameter along the longitudinal direction as the minimum diameter of inner circumferential surface 115a adjacent to proximal end side B. The inner circumferential surface 115c is formed in a tapered shape such that the inner diameter continuously decreases toward the tip side A. The inner circumferential surface 115d at the tip side A has an inner diameter that is the same as the minimum diameter of the adjacent inner circumferential surface 115c along the longitudinal direction.

[0033] In consideration of ease of operation when inserting the injection tube 11 into the hub lumen 224, the intermediate segment 112 may be formed so that its wall thickness decreases stepwise or continuously from the base end side B to the tip end side A. For example, the wall thickness of the intermediate segment 112 may be 0.02 to 0.55 mm at the end on the base end side B and 0.015 to 0.425 mm at the end on the tip end side A.

[0034] The distal segment 113 is formed with an outer diameter that is the same along the longitudinal direction as the smallest outer diameter of the intermediate segment 112. Because a portion of the distal end side A of the distal segment 113 is inserted into the catheter lumen 21a, the distal segment 113 has an outer diameter that is slightly smaller than the inner diameter of the catheter lumen 21a. That is, the outer diameter of the distal segment 113 is preferably slightly smaller than the inner diameter of the catheter lumen 21a (e.g., a clearance of 0.005 mm or more and 0.05 mm or less) to enable smooth insertion into the catheter lumen 21a and to prevent leakage and backflow of the drug.

[0035] Specifically, when the inner diameter of the base end side B of the catheter main body 21 is 0.52 mm, the outer diameter of the tip side segment 113 is preferably 0.51 mm or less (e.g., approximately 0.47 to 0.51 mm) and the inner diameter is preferably 0.46 mm or less (e.g., approximately 0.42 to 0.46 mm). By setting the outer and inner diameters of the tip side segment 113 to the above values, the thickness is reduced, and flexibility can be imparted to the tip side segment 113. For example, to impart flexibility, the thickness of the tip side segment 113 may be 0.005 to 0.045 mm, 0.01 to 0.04 mm, or 0.015 to 0.035 mm. Note that when the outer and inner diameters of the catheter main body 21 are wider on the base end side B, the outer diameter of the tip side segment 113 may be equal to or less than the maximum inner diameter of the microcatheter (e.g., 1 mm or less). Furthermore, the wall thickness of the tip side segment 113 may be, for example, 0.015 mm or more or 0.03 mm or more, taking into consideration the operability (bending rigidity) when inserting it into the hub lumen 224 and the catheter lumen 21a. The inner and outer diameters of the tip side segment 113 vary depending on the inner diameter of the catheter lumen 21a, but may be 0.10 to 0.92 mm, 0.40 to 0.95 mm, and 0.015 to 0.425 mm.

[0036] When the distal end A of the injector tube 11 is inserted into the hub lumen 224 and connected to the catheter 2, the drug discharge port 113a opening at the distal end A of the injector lumen 115 is positioned within the catheter lumen 21a. Specifically, when the intermediate segment 112 and the distal end segment 113 of the drug injection device 1 are inserted into the hub lumen 224, as shown in Fig. 4, the drug discharge port 113a of the distal end segment 113 is positioned a predetermined length L (e.g., 5 to 15 mm) deeper into the distal end A than the base end surface 21b of the catheter main body 21. Note that the length L may be 1 mm or more.

[0037] The base end segment 111, the intermediate segment 112, and the tip end segment 113 are integrally formed from a material (e.g., fluorine-based resin, polyolefin-based resin, silicone-based resin, etc.) to which liquid embolic material is unlikely to adhere even if the liquid embolic material adheres, by a known molding method (e.g., injection molding, compression molding, blow molding, etc.).

[0038] As shown in FIG. 3(b), the threaded portion 12 includes a cylindrical portion 121 and a bottom portion 122. The cylindrical portion 121 has a screw thread 12a formed on its inner surface. The bottom portion 122 has an opening 122a with an inner diameter larger than the outer diameter of the outer peripheral surface of the base-end segment 111, and the corners of the end of the opening 122a are rounded. The material of the threaded portion 12 is not limited, but the threaded portion 12 can be formed by a known molding method (e.g., injection molding, compression molding, blow molding, etc.) or by machining a round bar.

[0039] 3(b), a convex portion 111b with rounded corners is provided partially or continuously around the entire outer periphery of the base-end segment 111. When the threaded portion 12 is press-fitted into the injection tube 11 from the tip side A, the bottom portion 122 is positioned between the convex portion 111b and the grip portion 114, and the convex portion 111b serves to prevent the threaded portion 12 from slipping out of the tip side A.

[0040] It should be noted that grip portion 114 may be omitted, as shown in Figure 3(c). In this case, to restrict movement of threaded portion 12 toward base end side B, convex portion 111c with rounded corners may be provided partially or continuously in the circumferential direction on the outer circumferential surface of base end segment 111. Threaded portion 12 may also be provided integrally with injection tube 11. Furthermore, pharmaceutical injection device 1 does not necessarily have to be provided with threaded portion 12.

[0041] (Method of manufacturing a drug injection device) Next, an example of a method for manufacturing the drug injection device 1 will be described. The injection tube 11 and the threaded portion 12 are formed separately. That is, the injection tube 11 is integrally formed by injection molding or the like from a material to which the liquid embolic substance does not easily adhere even if the liquid embolic substance adheres. The threaded portion 12 is integrally formed by injection molding or the like from a resin material. Next, as shown in FIG. 3(b), the threaded portion 12 is press-fitted into the injection tube 11 from the tip side A so that the bottom 122 of the threaded portion 12 is positioned between the protrusion 111b and the grip portion 114. The drug injection device 1 is manufactured in this manner.

[0042] (Connection of catheter, drug injection device and syringe) First, we will explain how to connect the catheter 2 and the drug injection device 1. The distal segment 113 and intermediate segment 112 of the drug injection device 1 are inserted into the hub lumen 224 of the catheter 2, and the threaded portion 12 is screwed onto the threaded projection 223 of the catheter 2. At this time, by holding the grip portion 114 with one hand and turning the threaded portion 12 with the other hand, the threaded projection 223 enters between the threads 12a of the threaded portion 12, and the catheter 2 and the drug injection device 1 are connected.

[0043] Next, we will explain the connection between drug injection device 1 and syringe 3. When cylindrical tip 36 of syringe 3, which contains a drug in syringe 31, is inserted into injection device lumen 115 of drug injection device 1 from base end side B, and threaded portion 35 is turned, threaded projection 116 of drug injection device 1 enters between threads 35a of threaded portion 35, and drug injection device 1 and syringe 3 are connected.

[0044] (Effects of the first embodiment) The drug injection assembly 100 according to the first embodiment provides the following advantages. (a) By connecting the drug injection device 1, which has the functions of both an injection needle and a closed connector, between the catheter 2 and the syringe 3, there is no need to use a long injection needle or other such device, thereby reducing the burden on the surgeon. (b) Because the drug discharge port 113a of the drug injection device 1 reaches the catheter lumen 21a, the drug such as a liquid embolic substance can be prevented from adhering to the hub lumen 224. (c) Drug injection device 1 has threaded portion 12 at its distal end A for connecting to catheter 2, allowing drug injection device 1 to be securely connected to catheter 2. Drug injection device 1 also has threaded projection 116 at its proximal end B for connecting to syringe 3, allowing syringe 3 with a locking mechanism to be securely connected to drug injection device 1. (d) The outer circumferential surface 112a of the intermediate segment 112 of the drug injection device 1 and the inner circumferential surface 224a of the catheter 2 are tapered at the same taper rate, ensuring a liquid-tight seal between the drug injection device 1 and the catheter 2. Furthermore, the inner circumferential surface 115a of the base end side B of the drug injection device 1 and the outer circumferential surface 36a of the nozzle 36 of the syringe 3 are tapered at the same taper rate, ensuring a liquid-tight seal between the drug injection device 1 and the syringe 3.

[0045] [Second embodiment] 5 to 9 show an example of the appearance of a drug injection device 1 according to a second embodiment of the present invention, with FIG. 5 being a perspective view, FIG. 6 being a front view, FIG. 7 being a plan view, FIG. 8 being a right side view, and FIG. 9 being a left side view. FIG. 10 is a cross-sectional view taken along line EE in FIG. 7. FIG. 11 is a front view of the tube section shown in FIG. 10. In the first embodiment, the injection tube 11 was formed as a single unit, but in this embodiment, the connector section 13 and the tube section 14 are formed separately and then joined together. Furthermore, in the first embodiment, the threaded section 12 was provided so as to be rotatable circumferentially relative to the injection tube 11, but in this embodiment, the threaded section 133 is provided by fixing it to the connector section 13. Below, this embodiment will be described, focusing on the differences from the first embodiment.

[0046] The drug injection device 1 according to this embodiment is formed by joining a connector section 13 equipped with a threaded portion 133 and a tube section 14 by a known joining method (for example, adhesive bonding, fusion bonding, etc.). The connector section 13 and the tube section 14 may be integrally formed from the same material. Here, the tube section 14 is an example of a tube.

[0047] The connector portion 13 comprises a tubular base-end segment 131 provided on the base-end side B, a tubular tip-end segment 132 provided on the tip-end side A of the base-end segment 131, and a threaded portion 133 fixed to the tip-end side A of the base-end segment 131. A threaded projection 134 that threadably engages with the threads 35a of the threaded portion 35 of the syringe 3 is formed on the base-end side B of the base-end segment 131. The outer peripheral surface 132a of the tip-end segment 132 is the portion that contacts the inner peripheral surface 224a of the base-end side B of the hub lumen 224. The outer peripheral surface 132a of the tip-end segment 132 is formed in a tapered shape (taper ratio 6 / 100) similar to the outer peripheral surface 112a of the intermediate segment 112 of the first embodiment. The pharmaceutical injection device 1 does not necessarily have to include the threaded portion 133.

[0048] Connector portion 13 also has injection tool lumen 135 that is open at both ends. Base end side B of injection tool lumen 135 opens as drug introduction port 131a. In consideration of drug injection resistance, injection tool lumen 135 is formed so that the inner diameter decreases stepwise or continuously from drug introduction port 131a on base end side B toward tip end side A. Specifically, inner circumferential surfaces 135a, 135b, and 135c are formed as inner circumferential surfaces that define injection tool lumen 135, for example, so that the inner diameter decreases continuously from base end side B toward tip end side A. Inner circumferential surface 135a that defines the lumen at the base end side B of injection tool lumen 135 is formed in a tapered shape (taper ratio 6 / 100) similar to inner circumferential surface 115a of the first embodiment.

[0049] The connector portion 13 is integrally formed with the tube portion 14 from a material that is easily bonded to the tube portion 14 (e.g., ABS, polyamide, etc.) by a known molding method (e.g., injection molding, compression molding, blow molding, etc.). Note that, like the tube portion 14, the connector portion 13 may be formed from a material to which the liquid embolic substance does not easily adhere even if the liquid embolic substance adheres to the connector portion 13 (e.g., fluorine-based resin, polyolefin-based resin, silicone-based resin, etc.).

[0050] The threaded portion 133 has a thread 133a formed on the inner surface thereof, which threadably engages with the threaded projection 223 provided on the base end side B of the catheter 2, similar to the threaded portion 12 of the first embodiment.

[0051] The tube portion 14 is composed of a first segment 141, a second segment 142, a third segment 143, and a fourth segment 144, arranged in this order from the base end side B. The third segment 143 is an example of a first element. The fourth segment 144 is an example of a second element.

[0052] The tube section 14 has a tube lumen 145 that is open at both ends. In consideration of the injection resistance of the drug, the tube lumen 145 is formed so that the inner diameter decreases stepwise or continuously from the base end side B toward the tip end side A. Specifically, inner circumferential surfaces 145a, 145b, 145c, and 145d are formed as inner circumferential surfaces that define the tube lumen 145 from the base end side B toward the tip end side A. The inner diameters of the inner circumferential surfaces 145a, 145b, and 145c are formed so that they continuously decrease from the base end side B toward the tip end side A. The inner circumferential surface 145d at the tip end side A has an inner diameter that is the same as the minimum diameter of the adjacent inner circumferential surface 145c along the longitudinal direction.

[0053] (Size range of each part of the tube) The first segment 141 is formed so that its inner and outer diameters continuously decrease and its wall thickness continuously increases from the base end side B to the tip end side A. The wall thickness may also continuously decrease from the base end side B to the tip end side A. Specifically, the first segment 141 may have an axial length of 3 to 10 mm, an inner diameter of 4.00 to 4.20 mm, an outer diameter of 4.03 to 4.27 mm, and a wall thickness of 0.015 to 0.035 mm at the end of the base end side B. The second segment 142 has the same inner and outer diameters and wall thickness throughout its entire axial length. Specifically, the second segment 142 may have an axial length of 10 to 30 mm, an inner diameter of 0.50 to 3.96 mm, an outer diameter of 1.60 to 4.00 mm, and a wall thickness of 0.02 to 0.55 mm. 11, the second segment 142 may be formed so that the inner and outer diameters and wall thickness continuously decrease from the base end side B to the tip end side A. The third segment 143 is formed so that the inner and outer diameters and wall thickness continuously decrease from the base end side B to the tip end side A. The fourth segment 144 has the same inner and outer diameters and wall thickness over its entire axial length. Specifically, the fourth segment 144 can have an axial length of 10 to 30 mm, an inner diameter of 0.10 to 0.92 mm, an outer diameter of 0.40 to 0.95 mm, and a wall thickness of 0.015 to 0.425 mm, for example. However, the inner and outer diameters of the tip side A of the first segment 141 and the base side B of the second segment 142, the inner and outer diameters of the tip side A of the second segment 142 and the base side B of the third segment 143, and the inner and outer diameters of the tip side A of the third segment 143 and the base side B of the fourth segment 144 are all the same size.

[0054] (Typical examples of the sizes of each part of the tube) Representative examples of the sizes of the various portions of the tube portion 14 include the following: The first segment 141 has an axial length of 3 mm, an inner diameter of 4.00 mm, an outer diameter of 4.05 mm, and a wall thickness of 0.025 mm at its end on the base side B, and an inner diameter of 1.80 mm, an outer diameter of 1.90 mm, and a wall thickness of 0.05 mm at its end on the tip side A. The second segment 142 has an axial length of 15 mm, an inner diameter of 1.80 mm, an outer diameter of 1.90 mm, and a wall thickness of 0.05 mm. The third segment 143 has an axial length of 8 mm, an inner diameter of 1.80 mm, an outer diameter of 1.90 mm, and a wall thickness of 0.05 mm at its end on the base side B, and an inner diameter of 0.52 mm, an outer diameter of 0.55 mm, and a wall thickness of 0.015 mm at its end on the tip side A. The fourth segment 144 has an axial length of 15 mm, an inner diameter of 0.52 mm, an outer diameter of 0.55 mm, and a wall thickness of 0.015 mm.

[0055] The tube portion 14 is integrally formed by a known molding method (e.g., extrusion molding, injection molding, compression molding, blow molding, etc.) from a material to which a liquid embolic substance does not easily adhere even if the liquid embolic substance adheres (e.g., fluorine-based resin, polyolefin-based resin, silicone-based resin, etc.). The tube portion 14 may be formed from multiple layers. In this case, of the multiple layers constituting the tube portion 14, at least the innermost layer may be formed from a material to which a liquid embolic substance does not easily adhere even if the liquid embolic substance adheres.

[0056] (Method of manufacturing a drug injection device) Next, an example of a method for manufacturing the drug injection device 1 will be described. The connector portion 13 and the tube portion 14 are formed separately. That is, the connector portion 13 is integrally formed from a resin material by injection molding or the like. The tube portion 14 is integrally formed from a material to which the liquid embolic substance does not easily adhere even if the liquid embolic substance adheres by extrusion molding or the like. Next, as shown in FIG. 10(a), the outer peripheral surfaces of the first segment 141 and the second segment 142 of the tube portion 14 are joined to the inner peripheral surfaces 135b, 135c of the connector portion 13 by a known joining method (adhesion, fusion, etc.). The drug injection device 1 is manufactured in this manner.

[0057] (Connection of catheter, drug injection device and syringe) First, we will explain how to connect the catheter 2 and the drug injection device 1. The fourth segment 144 and the third segment 143 of the drug injection device 1 are inserted into the hub lumen 224 of the catheter 2, and the threaded portion 133 is screwed onto the threaded projection 223 of the catheter 2. At this time, by holding the threaded portion 133 by hand and turning the entire drug injection device 1, the threaded projection 223 enters between the threads 133a of the threaded portion 133, and the catheter 2 and the drug injection device 1 are connected.

[0058] Next, we will explain the connection between drug injection device 1 and syringe 3. When cylindrical tip 36 of syringe 3, which contains a drug in syringe 31, is inserted into injection device lumen 135 of drug injection device 1 from base end side B, and threaded portion 35 is turned, threaded projection 134 of drug injection device 1 enters between threads 35a of threaded portion 35, and drug injection device 1 and syringe 3 are connected.

[0059] (Effects of the second embodiment) The drug injection assembly 100 according to the second embodiment has the same effects as the first embodiment, and also enables the tubular portion (fourth segment 144) to be inserted into the catheter lumen 21a to be made thinner and have a smaller diameter by forming the tube portion 14 by extrusion molding or the like separately from the connector portion 13. This makes it possible to insert the distal end side A of the tube portion 14 into the catheter lumen 21a of the catheter main body 21 using a microcatheter.

[0060] [Variation 1] 12 is a front view of a pharmaceutical injection device of Modification 1. Pharmaceutical injection device 1 of Modification 1 is the same as in the first embodiment, except that a syringe 3a is provided on the base end side B of injector tube 11. That is, syringe 31a of injector 3a is provided integrally with injector tube 11 on the base end side B of injector tube 11, with a pharmaceutical agent already contained therein.

[0061] Specifically, injection tool tube 11 has a joint end 117 instead of threaded projection 116, and tip side A of syringe 31a of injector 3a is joined to joint end 117 by a known joining method (for example, adhesive bonding, fusion bonding, etc.). Also, inner circumferential surface 115a on the base end side of base end segment 111 shown in Figure 3(a) is omitted, and inner circumferential surface 115b extends to base end side B.

[0062] Syringe 3a does not have the threaded portion 35 and nozzle 36 shown in the first embodiment, but has the other components, finger flange 32, plunger 33 and pressing portion 34, in the same manner as in the first embodiment.

[0063] According to this modification 1, since the drug is contained in the syringe 31a in advance, it is not necessary to adjust the mixture ratio of NBCA and the oily contrast agent, fill the syringe with the NBCA mixture, connect the syringe to a drug injection tool, etc., and therefore it is possible to reduce the burden on the surgeon when injecting the NBCA mixture into a living body.

[0064] [Variation 2] Although not shown, pharmaceutical injection device 1 of Modification 2 is the second embodiment, but includes a syringe 3a similar to that of Modification 1 on base end side B of connector portion 13. That is, syringe 31a of syringe 3a is provided integrally with connector portion 13 on base end side B of connector portion 13, with the pharmaceutical agent already contained therein.

[0065] Specifically, the connector portion 13 has a joining end portion as shown in FIG. 12 instead of the screw projection 134, and the tip side A of the syringe 31a of the injector 3a is joined to the joining end portion by a known joining method (e.g., adhesive bonding, fusion bonding, etc.).

[0066] According to this modification 2, similar to the modification 1, it is possible to reduce the burden on the operator when injecting the NBCA mixture into a living body.

[0067] Although the embodiments of the present invention have been described above, the embodiments of the present invention are not limited to the above embodiments and various modifications and implementations are possible. For example, in the above embodiment and Modification 1, the NBCA mixture was described as the drug, but the drug is not limited to the NBCA mixture and may be other drugs. [Explanation of symbols]

[0068] 1...drug injection device, 2...catheter, 3, 3a...syringe, 11...injection device tube, 12...threaded portion, 12a...thread thread, 13...connector portion, 14...tube portion, 21...catheter body, 21a...catheter lumen, 21b...base end surface, 22...hub, 23...strain relief, 31...syringe, 32...finger flange, 33...plunger, 34...pressure portion, 35...threaded portion, 35a...thread thread, 36...tube tip, 100...drug injection assembly, 111...base end segment, 111a...drug introduction port, 111b, 111c...convex portion, 112...intermediate segment, 112a...outer circumferential surface, 113...tip end segment, 113a...drug discharge port, 114...gripping portion, 115...injection device lumen, 115a, 115b, 115c, 11 5d...inner peripheral surface, 116...threaded projection, 117...joint end portion, 121...tubular portion, 122...bottom portion, 122a...opening, 131...base end segment, 131a...drug introduction port, 132...tip end segment, 132a...outer peripheral surface, 133...threaded portion, 133a...thread, 134...threaded projection, 135...injection tool lumen, 135a, 135b, 135c...inner peripheral surface, 141... First segment, 142...second segment, 143...third segment, 144...fourth segment, 145...tube lumen, 145a, 145b, 145c, 145d...inner circumferential surface, 221...hub tube, 222A, 222B...wing portion, 223...screw projection, 224...hub lumen, 224a, 224b...inner circumferential surface, 224c...fitting hole, A...tip side, B...base side

Claims

1. A drug injection device in which a catheter including a catheter body having a catheter lumen and a hub joined to the base end side of the catheter body and having a hub lumen communicating with the catheter lumen is connected to a distal end side, and a drug accommodated in a syringe is supplied from the base end side, A drug injection device that injects the drug supplied from the syringe into a living body via the catheter lumen without passing through the hub lumen.

2. a tube having an injection tool lumen that is open at both ends in the axial direction; When the distal end of the tube is inserted into the hub lumen and connected to the catheter, the injection tool lumen is in direct fluid communication with the catheter lumen. The drug injection device according to claim 1.

3. When the distal end of the tube is inserted into the hub lumen and connected to the catheter, the drug discharge port opening at the distal end of the injection tool lumen is positioned at a position where it is inserted into the catheter lumen. The drug injection device according to claim 2.

4. the tube comprises a tapered first element and a second element provided at a distal end side of the first element, having the medicine ejection port at the distal end side, and having a constant outer diameter over the entire length in the axial direction; The first element is formed so that the inner and outer diameters and the wall thickness become smaller stepwise or continuously from the base end side to the tip end side. The drug injection device according to claim 3.

5. At least the inner surface of the tube is made of a material to which the drug does not easily adhere even if the drug adheres. The drug injection device according to claim 4.

6. the agent is a liquid containing a cyanoacrylate adhesive; At least the inner surface of the tube is formed of a fluorine-based resin, an olefin-based resin, or a silicone-based resin. The drug injection device according to claim 5.

7. a connector portion formed separately from the tube, joined to the tube, and connected to the syringe; the distal end portion of the tube is inserted into the catheter lumen when the catheter is connected to the distal end of the tube; The drug injection device according to claim 6.

8. the catheter body is a catheter body of a microcatheter, The outer diameter of the distal end portion of the tube inserted into the catheter lumen is equal to or smaller than the maximum inner diameter of the microcatheter. The drug injection device according to claim 7.

9. Further comprising the syringe, The syringe is provided integrally with the tube on the proximal end side of the tube in a state in which the drug is contained in advance. The drug injection device according to any one of claims 1 to 8.

10. The drug injection device according to any one of claims 1 to 9; the catheter; A drug injection assembly comprising:

11. The distal end side of the hub has a fitting hole through which the proximal end side portion of the catheter body fits into the inner circumferential surface of the hub.

11. The drug injection assembly of claim 10.

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