Needle catheter and puncture needle system

Abstract

This needle catheter is provided with a hollow tip section comprising a puncture needle, a hollow intermediate section provided continuously with the tip section nearer the base end side than the tip section, and a hollow base end section provided continuously with the intermediate section nearer the base end side than the intermediate section. The rigidity of the tip section is greater than the rigidity of the intermediate section, and the rigidity of the base end section is greater than the rigidity of the intermediate section.

Description

Needle catheter and needle system

[0001] The present disclosure relates to needle catheters and needle insertion systems.

[0002] Catheters equipped with hollow puncture needles are known. For example, Patent Document 1 discloses an indwelling needle assembly including an inner needle to be inserted into a subject and a catheter into which the inner needle is inserted. Patent Document 2 discloses a puncture device including a puncture needle having a curved portion, a holding member for holding the puncture needle, an indwelling device to be placed in the body by the puncture needle, and a guide member to be placed at a predetermined position on the body surface. Hereinafter, catheters equipped with puncture needles, as in Patent Documents 1 and 2, will also be referred to as "needle catheters." Patent Document 3 discloses a spinal anesthesia needle having a dot-like or annular step formed on the outer circumferential surface of the tip.

[0003] Incidentally, a known regenerative therapy method for regenerating cardiomyocytes whose function has been impaired by myocardial infarction or other conditions involves preparing cardiomyocytes in a sheet form outside the body and attaching the cell sheet to the heart to promote cardiomyocyte regeneration (see, for example, Patent Document 4). However, because the heart is constantly beating, it is difficult to stably attach a cell sheet to the heart for an extended period of time. Therefore, a therapeutic method that promotes cardiomyocyte regeneration by injecting a medicinal solution into cardiomyocytes is anticipated. This therapeutic method will hereinafter be referred to as "medicinal solution injection therapy." In medicinal solution injection therapy, a medicinal solution prepared by culturing and inducing differentiation of stem cells is injected into the myocardium via the coronary artery.

[0004] Japanese Patent Application Laid-Open No. 2008-43445 Japanese Patent Application Laid-Open No. 2007-117392 International Publication No. 02 / 04051 Pamphlet Japanese Patent Application Laid-Open No. 5572138

[0005] In the above-described drug solution injection therapy, the needle catheters described in Patent Documents 1 and 2 can be used to inject drug solutions into the myocardium from the coronary artery. However, in order for the puncture needle to reach the injection site of the drug solution, the needle catheter needs to be curved significantly inside the coronary artery. The injection site of the drug solution is the area of ​​the body tissue to be punctured. In this regard, with the needle catheters described in Patent Documents 1 and 2, when the needle catheter is curved significantly, there is a possibility that the needle catheter cannot be delivered within the delivery catheter or the puncture needle may damage the inside of the delivery catheter, leaving room for improvement.

[0006] These problems are not limited to drug injection therapy, but are common to all percutaneous procedures using needle catheters, including those inserted into the body lumen, such as the lymphatic system, biliary system, urinary system, respiratory system, digestive system, secretory glands, and reproductive organs, as well as the vascular system.

[0007] The present disclosure has been made to solve at least some of the above-mentioned problems, and aims to provide a needle catheter that can exhibit stable deliverability regardless of the curved shape of the biological lumen and can effectively puncture the target area.

[0008] The present disclosure has been made to solve at least part of the above-mentioned problems, and can be realized in the following aspects.

[0009] (1) According to one aspect of the present disclosure, there is provided a needle catheter comprising: a hollow distal end portion made of a puncture needle; a hollow intermediate portion provided proximally of the distal end portion and continuous with the distal end portion; and a hollow proximal end portion provided proximally of the intermediate portion and continuous with the intermediate portion, wherein the distal end portion has a greater rigidity than the intermediate portion, and the proximal end portion has a greater rigidity than the intermediate portion.

[0010] The intermediate section of the needle catheter is located between the distal end, which is made of a puncture needle, and the proximal end, and can be advanced through a highly curved portion of the blood vessel within the lumen of a delivery catheter previously inserted into the blood vessel. In this regard, according to the present configuration, the rigidity of the intermediate section is smaller than that of the distal and proximal ends, allowing the surgeon to smoothly advance the needle catheter even through a highly curved portion of the blood vessel. According to this configuration, the rigidity of the proximal end, which is closer to the surgeon's hand, is greater than that of the intermediate section, improving pushability and allowing the surgeon to easily push the needle catheter. Furthermore, according to this configuration, the rigidity of the distal end, which includes the puncture needle for puncturing body tissue, is greater than that of the intermediate section, allowing for easy puncture of body tissue. As a result, a needle catheter can be provided that exhibits stable deliverability regardless of the curved shape of the biological lumen and can effectively puncture the target area of ​​body tissue.

[0011] (2) In the needle catheter of the above embodiment, the puncture section includes the distal end portion and a distal portion of the intermediate section, and the puncture section is inserted into body tissue. The puncture section may include a distal puncture section including the puncture needle and a proximal puncture section continuous with the distal puncture section, and the proximal puncture section may have a lower rigidity than the distal puncture section. In a medical treatment method for injecting a drug solution into cardiomyocytes to promote cell regeneration, i.e., drug solution injection therapy, a puncture section is inserted from inside a coronary artery into the myocardium to inject the drug solution. Therefore, the puncture needle of the needle catheter used in drug solution injection therapy often has a curved shape. In this regard, according to this configuration, the rigidity of the proximal puncture section of the puncture section inserted into body tissue is lower than the rigidity of the distal puncture section including the puncture needle. Therefore, even when the puncture needle has the curved shape described above, the proximal puncture section, which has a lower rigidity, bends within the lumen of the delivery catheter, allowing the puncture section to advance smoothly. In other words, the proximal puncture portion functions as a buffer within the lumen of the delivery catheter, allowing the puncture portion to advance smoothly. Even when the puncture portion is exposed from the opening of the delivery catheter to puncture body tissue, the surgeon can push the needle catheter with the puncture needle inserted into the body tissue, thereby bending the proximal puncture portion, which has low rigidity, and puncturing the body tissue more deeply while maintaining the inclination of the puncture needle inserted into the body tissue. As a result, the accuracy of puncturing the target area can be improved, and a needle catheter can be provided that can more effectively puncture the target area of ​​body tissue.

[0012] (3) In the needle catheter of the above embodiment, the base-end puncture portion may have lower sliding properties relative to body tissue than the distal-end puncture portion. With this configuration, the base-end puncture portion has lower sliding properties relative to body tissue than the distal-end puncture portion, and therefore the puncture resistance of the base-end puncture portion is higher than that of the distal-end puncture portion. Therefore, when the base-end puncture portion has been inserted into the body tissue, the surgeon can easily tell from the change in feel at the hand that the proximal puncture portion has been inserted. As a result, the surgeon can be prevented from accidentally inserting the puncture portion deeper than necessary. As a result, the accuracy and safety of puncturing the target area can be improved, and a needle catheter can be provided that can more effectively puncture the target area of ​​body tissue.

[0013] (4) In the needle catheter of the above embodiment, the puncture section may have a curved section and a linear straight section that is continuous with the curved section and is located proximal to the curved section, and in a side view in which the curved shape of the curved section can be seen, the distance from the tip D of the puncture section to the side of the line defining the outer periphery of the intermediate section that is farther from the tip D may be greater than the inner diameter of the delivery catheter into which the needle catheter is inserted. According to this configuration, the puncture section has a curved section and a linear straight section, and in a side view in which the curved shape of the curved section can be seen, the distance from the tip D of the puncture section to the side of the line defining the outer periphery of the intermediate section that is farther from the tip D (i.e., the bending width of the puncture needle) is greater than the inner diameter of the delivery catheter into which the needle catheter is inserted. Therefore, by using a needle catheter of this configuration, the puncture section can be easily exposed from an opening in the delivery catheter and used to puncture body tissue during drug solution injection therapy.

[0014] (5) In the needle catheter of the above embodiment, the puncture portion may have a distal end surface at its distal end, and the distal end surface may be curved in a direction opposite to the bending direction of the bending portion in a side view in which the curved shape of the bending portion can be confirmed. According to this configuration, the distal end surface of the puncture portion is curved in a direction opposite to the bending direction of the bending portion in a side view in which the curved shape of the bending portion can be confirmed. This prevents the tip of the puncture portion from getting caught on the inner circumferential surface of the delivery catheter when the puncture portion is advanced within the lumen of the delivery catheter. As a result, damage to the delivery catheter and the puncture portion during delivery can be reduced.

[0015] (6) In the needle catheter of the above aspect, when the needle catheter is inserted into the delivery catheter and the incident angle α of the puncture portion with respect to the inner circumferential surface of the delivery catheter is greater than 0° and less than 10°, the inclination angle β of the distal end surface of the puncture portion with respect to the inner circumferential surface of the delivery catheter may be greater than 0°. With this configuration, even when the needle catheter is inserted into the delivery catheter and the incident angle α of the puncture portion with respect to the inner circumferential surface of the delivery catheter increases to approximately 10°, the distal end surface of the puncture portion can be kept floating above the inner circumferential surface of the delivery catheter. In other words, the distal end surface of the puncture portion can be kept separated from the inner circumferential surface of the delivery catheter. As a result, damage to the delivery catheter and the puncture portion during delivery can be suppressed.

[0016] (7) According to one aspect of the present disclosure, a puncture needle system is provided. This puncture needle system includes the needle catheter of the above aspect and a delivery catheter into which the needle catheter is inserted. The delivery catheter has a lumen into which the needle catheter is inserted and a side opening on the side of the delivery catheter that connects the lumen to the outside. When the needle catheter is inserted into the delivery catheter and the tip end is pushed forward to the side opening, the tip end protrudes from the side opening. This configuration provides a puncture needle system including a needle catheter and a delivery catheter that is suitable for drug solution injection therapy. According to this configuration, the delivery catheter has a side opening on the side of the delivery catheter through which the tip end of the needle catheter protrudes. Therefore, compared to a configuration in which the tip end of the needle catheter protrudes from the tip opening of the delivery catheter, it is easier to puncture the myocardium from inside the coronary artery.

[0017] The present disclosure can be realized in various forms, for example, in the form of a puncture needle, a needle catheter having a puncture needle, a puncture needle system including a needle catheter and a combination device, and a method of manufacturing these.

[0018] 2 is an explanatory diagram illustrating the configuration of a puncture needle system. FIG. 2 is an explanatory diagram illustrating the configuration of a needle catheter. FIG. 2 is a transverse cross-sectional view taken along line A-A in FIG. 2. FIG. 2 is a transverse cross-sectional view taken along line B-B in FIG. 2. FIG. 2 is a transverse cross-sectional view taken along line CC in FIG. 2. FIG. 2 is an enlarged view of the vicinity of the tip of the needle catheter. FIG. 2 is a view showing the tip of the needle catheter when not inserted into a delivery catheter. FIG. 2 is a view showing the tip of the needle catheter when inserted into a delivery catheter. FIG. 2 is a view showing the state of the heart during a drug solution injection treatment procedure. FIG. 2 is an explanatory diagram showing the state of delivering the needle catheter with the delivery catheter. FIG. 2 is an explanatory diagram showing the state of removing the stylet wire. FIG. 2 is an explanatory diagram showing the state of protruding the needle catheter from the delivery catheter. FIG. 2 is an explanatory diagram showing the state of puncturing the myocardium with the needle catheter. FIG. 2 is an enlarged view of the vicinity of the tip of the needle catheter of the second embodiment. FIG. 2 is an enlarged view of the vicinity of the tip of the needle catheter of the third embodiment. FIG. 2 is an enlarged view of the vicinity of the tip of the needle catheter of the fourth embodiment. FIG. 2 is a transverse cross-sectional view taken along line A-A in FIG. 2. FIG. 2 is a transverse cross-sectional view taken along line B-B in FIG. 2. 10 is a cross-sectional view of the needle catheter of the fifth embodiment taken along the line CC. FIG. 11 is a cross-sectional view of the needle catheter of a modified example taken along the line CC.

[0019] First Embodiment FIG. 1 is an explanatory diagram illustrating the configuration of a puncture needle system 1000. The puncture needle system 1000 of this embodiment includes a delivery catheter 1, a needle catheter 2, and a stylet wire 3. The puncture needle system 1000 is inserted into a body lumen, such as the vascular system, lymphatic system, biliary system, urinary system, respiratory system, digestive system, secretory glands, and reproductive organs, and is used to inject a liquid into body tissue. Hereinafter, a drug solution injection therapy will be illustrated as an example of a specific application of the puncture needle system 1000. Drug solution injection therapy is a treatment method that promotes the regeneration of cardiomyocytes by injecting a drug solution into cardiomyocytes. In this drug solution injection therapy, a drug solution produced by culturing and inducing differentiation of stem cells is injected into the myocardium through a coronary artery. In this embodiment, "large curvature" means a large curvature. A large curvature means a small radius of curvature and a sharp curve.

[0020] For ease of explanation, Figure 1 includes some parts where the relative size ratios of the components are different from the actual ones. Some of the components are exaggerated. Figure 1 illustrates mutually orthogonal X, Y, and Z axes. The X axis corresponds to the longitudinal direction of the delivery catheter 1, needle catheter 2, and stylet wire 3, the Y axis corresponds to the height direction of the delivery catheter 1, needle catheter 2, and stylet wire 3, and the Z axis corresponds to the width direction of the delivery catheter 1, needle catheter 2, and stylet wire 3. The left side (-X axis direction) of Figure 1 is referred to as the "distal side" of each device and component, and the right side (+X axis direction) of Figure 1 is referred to as the "proximal side" of each device and component. Of the two ends of each device and component in the longitudinal direction (X axis direction), the end located on the distal side is referred to as the "distal end," and the other end located on the proximal side is referred to as the "proximal end." The distal end and its vicinity are referred to as the "distal portion," and the proximal end and its vicinity are referred to as the "proximal end." The distal end is inserted into the living body, and the proximal end is operated by an operator such as a doctor. These points are also common to the figures shown in Fig. 2 and subsequent figures.

[0021] A needle catheter 2 is inserted into a delivery catheter 1. The delivery catheter 1 is a catheter for delivering the needle catheter 2 to the injection site of a medicinal solution (i.e., the area of ​​body tissue to be punctured). As shown in Fig. 1, the delivery catheter 1 includes a distal tip 11, a catheter shaft 12, and a connector 19. The delivery catheter 1 of this embodiment is a single-lumen catheter having one side opening 1c.

[0022] The distal tip 11 is attached to the distal end of the catheter shaft 12 and moves through the blood vessel ahead of other components. The distal tip 11 is a cylindrical component with an outer diameter that gradually decreases from the proximal end to the distal end. A distal opening 1a is formed at the distal end of the distal tip 11. The distal opening 1a is an opening for inserting other devices (e.g., a delivery guide wire called a workhorse wire) into the delivery catheter 1.

[0023] The catheter shaft 12 is a cylindrical member (tubular body) with an elongated outer shape. A side opening 1c, which is a through-hole that communicates the inside and outside of the catheter shaft 12, is formed at the distal end of the catheter shaft 12. The side opening 1c is an opening that allows the distal end of the needle catheter 2 to protrude from the delivery catheter 1. The shape of the side opening 1c when viewed from the -Y axis direction is rectangular. The shape of the side opening 1c may be any shape. The arbitrary shape may be, for example, a circle, a square, or a polygon. A distal tip 11 is fixed to the distal end of the catheter shaft 12. A connector 19 is fixed to the proximal end of the catheter shaft 12.

[0024] The connector 19 is attached to the proximal end of the catheter shaft 12, making it easier for the surgeon to grasp the device. The connector 19 is a generally cylindrical member provided with a pair of wings. A proximal end opening 1b is formed at the proximal end of the connector 19. The proximal end opening 1b is an opening for inserting the needle catheter 2 or other devices into the delivery catheter 1. An example of such other devices is a workhorse wire.

[0025] As shown by dashed lines in Figure 1, the distal tip 11, catheter shaft 12, and connector 19 have a delivery lumen 1L formed in them along the longitudinal direction of the delivery catheter 1, connecting the interiors of each section. The delivery lumen 1L is a lumen into which the needle catheter 2 and other devices are inserted. The inner diameter Φ1L of the delivery lumen 1L may be determined arbitrarily as long as it is larger than the outer diameters of the intermediate section 22 and proximal end section 23 of the needle catheter 2. The proximal end of the delivery lumen 1L communicates with the outside through a proximal end opening 1b. The distal end of the delivery lumen 1L communicates with the outside through a distal end opening 1a. The distal end of the delivery lumen 1L communicates with the outside through a side opening 1c.

[0026] The distal tip 11 can be formed from a flexible resin material, such as polyurethane elastomer. The distal tip 11 may also be formed from a radiopaque resin or metal material. For example, when using a radiopaque resin material, the distal tip 11 can be formed by mixing a radiopaque material such as bismuth trioxide, tungsten, or barium sulfate with polyamide resin, polyolefin resin, polyester resin, polyurethane resin, silicone resin, or fluororesin. For example, when using a radiopaque metal material, the distal tip 11 can be formed from at least one of gold, platinum, and tungsten. The distal tip 11 may also be formed from an alloy containing at least one of gold, platinum, and tungsten (e.g., a platinum-nickel alloy). The catheter shaft 12 and the connector 19 can be formed from known materials, such as nylon resin, polyolefin, polyester, thermoplastic resin, polyamide elastomer, polyolefin elastomer, polyurethane elastomer, silicone rubber, and latex rubber. An example of a nylon resin is polyamide. Examples of polyolefins include polyethylene, polypropylene, and ethylene-propylene copolymers. Examples of polyesters include polyethylene terephthalate. Examples of thermoplastic resins include polyvinyl chloride, ethylene-vinyl acetate copolymers, cross-linked ethylene-vinyl acetate copolymers, and polyurethanes.

[0027] The needle catheter 2 is a catheter for injecting a medicinal solution into body tissue. As shown in Fig. 1, the needle catheter 2 includes a distal end portion 21, an intermediate portion 22, a proximal end portion 23, a marker 24, and a connector 29. The needle catheter 2 of this embodiment is a single-lumen catheter having one needle.

[0028] The distal end portion 21 is a hollow puncture needle attached to the distal end of the intermediate portion 22. The puncture needle is also simply called a "needle." The distal end portion 21 has an outer diameter that gradually decreases from the proximal end toward the distal end, and the distal end has a sharp shape to facilitate puncturing body tissue. The distal end portion 21 is curved in a specific direction. In the example shown, the distal end portion 21 is curved in the -Y axis direction. A distal end opening 2a is formed at the distal end of the distal end portion 21. The distal end opening 2a is used to project the stylet wire 3 during delivery of the needle catheter 2, and is an opening used to eject the medicinal solution during medicinal solution injection through the needle catheter 2. The puncture needle 21 may be integral with the intermediate portion 22 or may be separate from the intermediate portion 22.

[0029] The intermediate portion 22 is continuous with the distal portion 21, on the proximal side of the distal portion 21. The intermediate portion 22 has a long cylindrical shape, in other words, a tubular shape, and is a portion with a constant outer diameter. The proximal portion 23 is continuous with the intermediate portion 22, on the proximal side of the intermediate portion 22. The proximal portion 23 has a long cylindrical shape, in other words, a tubular shape, and is a portion with a constant outer diameter. As shown in the figure, the outer diameter of the intermediate portion 22 and the outer diameter of the proximal portion 23 are the same. In this embodiment, "same" and "equal" do not necessarily mean strict agreement, but also mean allowing for differences due to manufacturing errors, etc. "Constant" is synonymous with "approximately constant" and means being approximately constant while allowing for variations due to manufacturing errors, etc.

[0030] The marker 24 functions as a mark for enabling confirmation of the position of the distal end portion 21 under an X-ray image. An X-ray image is also called an annular image. The marker 24 is an annular member provided between the distal end portion 21 and the intermediate portion 22, specifically, at the distal end of the intermediate portion 22. The marker 24 may have any shape other than an annular shape, or may be omitted. The marker 24 can be formed from a radiopaque resin material or a metal material.

[0031] Connector 29 is attached to the proximal end side of proximal portion 23, making it easier for the surgeon to grasp the device. Connector 29 is a substantially cylindrical member provided with a pair of wings. A proximal end opening 2b is formed at the proximal end of connector 29. Proximal end opening 2b is used to insert stylet wire 3 during delivery of needle catheter 2, and is an opening used to attach a syringe for supplying medicinal liquid during medicinal liquid injection through needle catheter 2. Connector 29 can be made of a well-known resin material.

[0032] As shown by dashed lines in Figure 1, a lumen 2L is formed in the distal end portion 21, intermediate portion 22, proximal end portion 23, and connector 29, connecting the interiors of each portion along the longitudinal direction of the needle catheter 2. The lumen 2L is a lumen for inserting the stylet wire 3. The lumen 2L is a lumen through which a medicinal solution flows. The inner diameter Φ2L of the lumen 2L may be determined arbitrarily as long as it is larger than the outer diameter Φ3 of the stylet wire 3. The distal end of the lumen 2L communicates with the outside through a distal end opening 2a. The proximal end of the lumen 2L communicates with the outside through a proximal end opening 2b.

[0033] The stylet wire 3 is a wire that protects the delivery catheter 1 and the needle catheter 2 when the puncture needle system 1000 is in use, and that provides rigidity to the needle catheter 2, thereby facilitating delivery of the needle catheter 2. The stylet wire 3 includes a core wire and a coil body. For convenience of illustration, the core wire and coil body are omitted from Figure 1.

[0034] The core wire is a cylindrical member having an elongated outer shape. The core wire may have a constant outer diameter, or may have an outer diameter that decreases from the base end to the tip end. The coil body is formed by helically winding a wire. The coil body is disposed so as to surround a portion of the core wire at the tip end and is fixed to the core wire. The coil body may be disposed so as to surround the entire core wire from the tip end to the base end. The outer diameter Φ3 of the coil body is defined as the outer diameter of the stylet wire 3. In this embodiment, the outer diameter Φ3 of the stylet wire 3 is the smallest inner diameter of the distal end portion 21 of the needle catheter 2 (i.e., the inner diameter of the tip of the distal end portion 21) minus a predetermined clearance value. In other words, the tip of the needle catheter 2 has an inner diameter obtained by adding a predetermined clearance value to the outer diameter Φ3 of the stylet wire 3.

[0035] The core wire can be formed using at least one of a stainless steel alloy, a superelastic alloy, a piano wire, a nickel-chromium alloy, a cobalt alloy, and tungsten. Examples of stainless steel alloys include SUS302, SUS304, and SUS316. Examples of superelastic alloys include nickel-titanium. The core wire may be formed using known materials other than those listed above. The coil body can be formed using at least one of a stainless steel alloy, a superelastic alloy, a radiolucent alloy, and a radiopaque alloy. Examples of stainless steel alloys include SUS304 and SUS316. Examples of superelastic alloys include nickel-titanium alloys. Examples of radiolucent alloys include piano wire, a nickel-chromium alloy, and a cobalt alloy. Examples of radiopaque alloys include gold, platinum, tungsten, and alloys containing these elements (e.g., platinum-stainless steel alloys, platinum-nickel alloys). The coil body may be made of known materials other than those mentioned above.

[0036] FIG. 2 is an explanatory diagram illustrating the configuration of the needle catheter 2. FIG. 3 is a cross-sectional view taken along line A-A in FIG. 2. FIG. 4 is a cross-sectional view taken along line B-B in FIG. 2. FIG. 5 is a cross-sectional view taken along line CC in FIG. 2. In FIGS. 2 to 5, an axis O passing through the centers of the intermediate section 22, the base end section 23, and the connector 29 is illustrated. The X, Y, and Z axes in FIGS. 2 and 3 correspond to each other. The configuration of the needle catheter 2 will be described in detail below.

[0037] The tip section 21 is the portion of the needle catheter 2 located at the most distal end. As shown in FIG. 3, the tip section 21 is configured as a hollow puncture needle. At the base end of the tip section 21, the center of the tip section 21 coincides with the axis O. The distal end of the tip section 21 is given a curved shape that is curved in a specific direction (the -Y axis direction in the illustrated example). Therefore, at the distal end of the tip section 21, the center of the tip section 21 is inclined with respect to the axis O. The tip section 21 (puncture needle) can be formed from a metal with shape memory properties, such as a nickel-titanium alloy or a CuZnAl alloy. As shown in FIG. 2, in the needle catheter 2, the tip section 21 is a section S21 from the tip of the puncture needle to the tip of the marker 24.

[0038] The intermediate portion 22 is located closer to the base end than the distal end portion 21, in other words, between the distal end portion 21 and the base end portion 23. As shown in FIG. 4 , the intermediate portion 22 includes a coil body 221 and a tube 222.

[0039] The tube 222 is provided to prevent leakage of the medicinal solution from the needle catheter 2. The tube 222 is a cylindrical member (tubular body) with an elongated outer shape. The distal end of the tube 222 is joined to the proximal end of the distal end portion 21 (puncture needle). The proximal end of the tube 222 is joined to the distal end portion of the connector 29. Any bonding agent can be used for the joining, for example, metal solder such as silver solder, gold solder, zinc, Sn—Ag alloy, or Au—Sn alloy, or adhesive such as epoxy adhesive or cyanoacrylic adhesive. The tube 222 can be formed from a resin with excellent chemical resistance, for example, polyimide resin.

[0040] The coil body 221 is provided to impart a predetermined rigidity and flexibility to the intermediate section 22 of the needle catheter 2, thereby improving the deliverability of the needle catheter 2. The coil body 221 is a multi-filament coil formed by winding multiple strands of wire. The coil body 221 is arranged to surround the outer circumferential surface of the tube 222. In the illustrated example, the inner circumferential surface of the coil body 221 and the outer circumferential surface of the tube 222 are in contact with each other. The distal end of the coil body 221 is bonded to the tube 222 and the distal end 21 (puncture needle), respectively. The proximal end of the coil body 221 is bonded to the tube 222 and the distal end of the shaft 231, respectively. Any bonding agent can be used for bonding, such as metal solder such as silver solder, gold solder, zinc, Sn—Ag alloy, or Au—Sn alloy, or an adhesive such as an epoxy adhesive or a cyanoacrylic adhesive. Note that bonding may be performed using two or more methods in combination.

[0041] The coil body 221 can be formed using at least one of a stainless steel alloy, a superelastic alloy, a radiolucent alloy, and a radiopaque alloy, for example. Examples of stainless steel alloys include SUS304 and SUS316. Examples of superelastic alloys include a nickel-titanium alloy. Examples of radiolucent alloys include piano wire, nickel-chromium alloys, and cobalt alloys. Examples of radiopaque alloys include gold, platinum, tungsten, and alloys containing these elements (e.g., platinum-stainless steel alloys and platinum-nickel alloys). The coil body 221 may also be formed using known materials other than those listed above. The coil body 221 may be a single-strand coil formed by winding a single wire. The coil body 221 may also be a single-strand stranded coil formed by winding a single wire made by twisting multiple wires together. The coil body 221 may be a multi-strand stranded coil formed by using a plurality of strands of wire twisted together and winding each strand of wire multiple times. As shown in Figure 2, in the needle catheter 2, the intermediate section 22 is a section S22 from the base end of the marker 24 to the boundary between the intermediate section 22 and the base end 23.

[0042] The base end portion 23 is located closer to the base end than the intermediate portion 22, in other words, between the intermediate portion 22 and the connector 29. As shown in Fig. 5, the base end portion 23 has a shaft 231 and a tube 222. The tube 222 is the same member as the tube 222 described in Fig. 4.

[0043] The shaft 231 is provided to impart a predetermined rigidity and torque transmission capability to the proximal end 23 of the needle catheter 2, thereby improving the deliverability of the needle catheter 2. The shaft 231 is a cylindrical member (tubular body) having an elongated outer shape. The shaft 231 is disposed so as to surround the outer circumferential surface of the tube 222. In the illustrated example, the inner circumferential surface of the shaft 231 and the outer circumferential surface of the tube 222 are in contact with each other. The distal end of the shaft 231 is bonded to the tube 222 and the proximal end of the coil body 221, respectively. The proximal end of the shaft 231 is bonded to the tube 222 and the connector 29, respectively. Any bonding agent can be used for bonding, for example, metal solder such as silver solder, gold solder, zinc, Sn—Ag alloy, or Au—Sn alloy, or adhesive such as epoxy adhesive or cyanoacrylic adhesive. Bonding may be performed using two or more methods in combination.

[0044] The shaft 231 can be made of known materials, such as stainless steel alloys such as SUS302, SUS304, and SUS316, and superelastic alloys such as nickel-titanium alloys. As shown in Fig. 2, in the needle catheter 2, the proximal end 23 is a section S23 extending from the boundary between the intermediate section 22 and the proximal end 23 to the tip of the connector 29. In the needle catheter 2 of this embodiment, the length of the intermediate section 22 in the longitudinal direction (the length of section S22) and the length of the proximal end 23 (the length of section S23) are approximately equal.

[0045] In this needle catheter 2, the rigidity of the distal end portion 21 is greater than that of the intermediate portion 22 (rigidity: distal end portion 21 > intermediate portion 22). The rigidity of the proximal end portion 23 is greater than that of the intermediate portion 22 (rigidity: proximal end portion 23 > intermediate portion 22). The rigidity can be calculated using a three-point bending test. The difference in rigidity between the distal end portion 21 and the intermediate portion 22 is due to the fact that the distal end portion 21 is composed of a metal puncture needle and the intermediate portion 22 is composed of a flexible coil body 221 and a resin tube 222. The difference in rigidity between the intermediate portion 22 and the proximal end portion 23 is due to the difference in configuration between the intermediate portion 22 and the proximal end portion 23, that is, the intermediate portion 22 includes a flexible coil body 221 and the proximal end portion 23 includes a metal shaft 231. The rigidity of the distal end portion 21 and the proximal end portion 23 may be the same, or the distal end portion 21 may have a greater rigidity, or the proximal end portion 23 may have a greater rigidity.

[0046] 6 is an enlarged view of the vicinity of the tip portion 21 of the needle catheter 2. With the needle catheter 2 of this embodiment, when it is desired to puncture deeper, for example when the myocardial layer is thick, not only the tip portion 21 (puncture needle) but also a portion of the intermediate portion 22 on the distal side is punctured into the body tissue. In this way, the portion of the needle catheter 2 that is punctured into the body tissue is also referred to as the "puncture portion 200." As described above, the puncture portion 200 includes the tip portion 21 and a portion of the intermediate portion 22 on the distal side.

[0047] 6, the puncturing section 200 has a distal puncturing section 201 consisting of the distal end section 21 (puncturing needle), and a proximal puncturing section 202 consisting of the marker 24 and a portion of the distal end side of the intermediate section 22. The proximal puncturing section 202 is located closer to the proximal end than the distal puncturing section 201 and is provided contiguous to the distal puncturing section 201. In the example shown, the proximal puncturing section 202 extends a length L1 from the tip of the marker 24. The length L1 may be determined arbitrarily.

[0048] At this time, the rigidity of the proximal puncture section 202 is smaller than the rigidity of the distal puncture section 201 (rigidity: distal puncture section 201 > proximal puncture section 202). The rigidity can be calculated by a three-point bending test. The difference in rigidity between the distal puncture section 201 and the proximal puncture section 202 is due to the fact that the distal puncture section 201 is composed of a metal puncture needle, and the proximal puncture section 202 is composed of a flexible coil body 221 and a resin tube 222. Because the length of the marker 24 in the longitudinal direction is short, it can be ignored when considering the difference in rigidity.

[0049] The base-end puncturing portion 202 has lower sliding properties against body tissue than the tip-end puncturing portion 201 (slidability: tip-end puncturing portion 201 > base-end puncturing portion 202). The sliding properties can be determined using sample A and body tissue sample B as follows: The operator prepares a sample of the tip-end puncturing portion 201 and a sample of the base-end puncturing portion 202 as sample A. With a force gauge attached to the base end of sample A, the operator punctures body tissue sample B and applies a certain pressing load. The operator performs the test on sample A of the tip-end puncturing portion 201 and sample A of the base-end puncturing portion 202, respectively. As a result of the test, the operator can determine that the larger the force gauge measurement value, the higher the puncture resistance against body tissue, i.e., the lower the sliding properties. The difference in sliding properties between the tip-end puncture portion 201 and the base-end puncture portion 202 is due to the fact that the tip-end puncture portion 201 has a smooth surface and is composed of a tapered puncture needle, while the base-end puncture portion 202 has a coil body 221 with an uneven surface.

[0050] A portion of puncture section 200 on the distal side that has a curved shape that is curved in one specific direction (the −Y axis direction in the illustrated example) is called curved section 211. A portion of puncture section 200 on the proximal side that is not curved and has a linear shape is called straight section 212. Straight section 212 is located closer to the proximal end than curved section 211 and is provided contiguous to curved section 211.

[0051] 2 and 6 are diagrams showing the needle catheter 2 in a side view in which the curved shape of the bending portion 211 can be confirmed. A side view in which the curved shape of the bending portion 211 can be confirmed means that the needle catheter 2 is viewed from a direction (Z-axis direction) in which the length of distance S, described below, appears longest and the distal end 21, intermediate portion 22, and proximal end 23 can be confirmed. In this side view, the tip of the distal end 21 is defined as point D. In the illustrated side view, point D is the tip of the puncture needle, in other words, the tip of the puncture portion 200. In this case, the distance S between the distal end D and a line FL that defines the outer periphery of the intermediate portion 22 farther from the tip D is greater than the inner diameter Φ1L of the delivery catheter 1 (see FIG. 1), i.e., the inner diameter Φ1L of the first lumen 1L (S>Φ1L). Of the two lines (i.e., the line on the +Y-axis direction and the line on the −Y-axis direction) that define the outer periphery of the intermediate section 22 in the side view, the line FL is the line farther from the tip D in the direction (Y-axis direction) that intersects with the extension direction of the intermediate section 22 (the X-axis direction in FIG. 6 ). The distance S is the distance from the tip D to point CP, where CP is defined as the point where a virtual line PL obtained by virtually extending line FL toward the tip intersects with a perpendicular line VD drawn from the tip D to virtual line PL. In other words, the distance S represents the bending width of the puncture needle 21. In other words, the distance S represents the length of the needle catheter 2 in the bending direction of the bending section 211 (the −Y-axis direction in the example of FIG. 6 ).

[0052] FIG. 7 is a diagram showing the tip of the needle catheter 2 when not inserted into the delivery catheter 1. FIG. 8 is a diagram showing the tip of the needle catheter 2 when inserted into the delivery catheter 1. As shown in the figures, the puncture section 200 has a tip surface 210 at its tip. This tip surface 210 is curved in the opposite direction to the bending direction of the bending section 211 in side views ( FIGS. 2 , 6 , 7 , and 8 ) in which the curved shape of the bending section 211 can be seen. Specifically, as shown in FIG. 6 , the bending section 211 is curved in the −Y-axis direction. On the other hand, as shown in FIGS. 6 to 8 , the tip surface 210 is curved in the +Y-axis direction. In other words, in side views ( FIGS. 2 , 6 , 7 , and 8 ) in which the curved shape of the bending section 211 can be seen, the arc formed by the outer periphery of the bending section 211 and the arc formed by the tip surface 210 face each other. 8 , the incident angle of the tip portion 21 with respect to the inner circumferential surface 12i within the delivery lumen 1L of the delivery catheter 1 is α, and the inclination angle of the tip surface 210 at the tip D with respect to the inner circumferential surface 12i is β. The tip surface 210 of the tip portion 21 has a curved shape such that the inclination angle β at the tip D of the tip surface 210 is greater than 0° (β > 0°) when the incident angle α of the tip portion 21 is at least greater than 0° and less than 10° (0° < α < 10°). In other words, the tip surface 210 is formed in a curved shape such that the tip D of the tip surface 210 is floating (separated) from the inner circumferential surface 12i of the delivery catheter 1 even when the incident angle α of the tip portion 21 increases to approximately 10°. In other words, the incident angle α is the angle between a line AL drawn along the side surface of the tip portion 21 that faces the delivery catheter 1 and the inner circumferential surface 12i in the side view of Fig. 8. The inclination angle β is the angle between a line BL drawn along the tip surface 210 of the tip portion 21 that faces the delivery catheter 1 and the inner circumferential surface 12i in the side view of Fig. 8. The incident angle α is determined by the inner diameter Φ1L of the delivery lumen 1L and the curvature of the tip portion 21 (puncture needle). The three-dimensional shape of the tip surface 210 is preferably spherical, but may also be a curved plate shape.

[0053] Having such a tip surface 210 can prevent the needle catheter 2 from damaging the inner circumferential surface 12i of the delivery catheter 1. Specifically, as shown in Fig. 8 , when the needle catheter 2 is directly inserted into the delivery catheter 1, the arc-shaped tip surface 210 of the needle catheter 2 comes into contact with the inner circumferential surface 12i of the delivery catheter 1, causing the tip D to be raised above the inner circumferential surface 12i. Therefore, even when the needle catheter 2 is directly inserted into the delivery catheter 1, damage to the inner circumferential surface 12i of the delivery catheter 1 by the sharp tip D can be prevented.

[0054] Figure 9 is a diagram showing the state of the heart during a drug solution injection treatment procedure. In this embodiment, a case where a drug solution is injected into a myocardium 96 from a left coronary artery 94 of a heart 90 is illustrated. The left side of Figure 9 shows the heart 90, and the guiding catheter 4, delivery catheter 1, and needle catheter 2 inserted into the heart 90. The right side of Figure 9 shows the delivery catheter 1 and needle catheter 2 in the left coronary artery 94. For ease of explanation, in Figure 9, the guiding catheter 4 is represented by a dashed line and the delivery catheter 1 is represented by a solid line.

[0055] As shown in the right-hand bubble in Figure 9 , the left coronary artery 94 has a curved shape that follows the surface of the spherical heart 90. When the needle catheter 2 advances through the delivery catheter 1 positioned along the left coronary artery 94, it is subjected to an outward force relative to the curvature of the left coronary artery 94. The curvature of the left coronary artery 94 is the same as the curvature of the delivery catheter 1. In Figure 9 , the force acting on the needle catheter 2 is indicated by a dashed arrow. The injection site of the drug solution through the needle catheter 2 is the myocardium 96 of the heart 90, which is located on the opposite side of the direction of the force acting on the needle catheter. Therefore, it is difficult for the tip 21 (puncture needle) of the needle catheter 2 to protrude from the side opening 1c of the delivery catheter 1. This is also true for the right coronary artery 95. However, with the puncture needle system 1000 of this embodiment, as will be described below, the needle catheter 2 can be delivered stably regardless of the curved shape of the blood vessels leading to the left coronary artery 94 and the right coronary artery 95, and the injection site for the medicinal solution can be punctured satisfactorily.

[0056] Figure 10 is an explanatory diagram showing the state in which the needle catheter 2 is delivered by the delivery catheter 1. Figure 11 is an explanatory diagram showing the state in which the stylet wire 3 is removed. Figure 12 is an explanatory diagram showing the state in which the needle catheter 2 is protruded from the delivery catheter 1. Figure 13 is an explanatory diagram showing the state in which the needle catheter 2 is inserted into the myocardium 96. For ease of explanation, in Figures 10 to 13, the needle catheter 2 inserted into the delivery lumen 1L of the delivery catheter 1 and the stylet wire 3 inserted into the lumen 2L of the needle catheter 2 are each represented by a solid line.

[0057] The surgeon can perform the procedure for drug solution injection therapy, for example, by following the steps a1 to a10 below. (a1) The surgeon inserts a work horse wire from the upper arm or thigh and delivers it to the entrance of the left coronary artery 94. The work horse wire is a guide wire used for delivery. (a2) The surgeon inserts the work horse wire from the tip of the guiding catheter 4 and delivers the guiding catheter 4 along the work horse wire to the entrance of the left coronary artery 94. (a3) ​​The surgeon inserts the work horse wire into the delivery catheter 1 by inserting it into the distal opening 1a of the delivery catheter 1 and pulling it out from the proximal opening 1b. The surgeon pushes the delivery catheter 1 along the work horse wire inside the guiding catheter 4. In this way, the delivery catheter 1 is guided to the entrance of the left coronary artery 94 using the guiding catheter 4. (a4) The surgeon further advances the delivery catheter 1 into the left coronary artery 94 until the side opening 1c of the delivery catheter 1 reaches a position in the left coronary artery 94 near the injection site of the medicinal solution. At this time, the surgeon adjusts the circumferential orientation of the delivery catheter 1 so that the side opening 1c of the delivery catheter 1 is positioned on the side of the myocardium 96, as shown in FIG. 10 . The surgeon then removes the workpiece wire from the delivery catheter 1.

[0058] (a5) The surgeon inserts the stylet wire 3 into the needle catheter 2 by inserting it through the proximal end opening 2b of the needle catheter 2 and withdrawing it from the distal end opening 2a. At this time, the surgeon leaves the stylet wire 3 protruding a certain length from the distal end opening 2a of the needle catheter 2. (a6) The surgeon inserts the needle catheter 2 with the stylet wire 3 inserted into it through the proximal end opening 1b of the delivery catheter 1. At this time, the surgeon gently curves the bending portion 211 of the needle catheter 2 until the length of the distal end portion 211 in the bending direction (the -Y direction in Figure 6) becomes equal to or less than the inner diameter of the delivery catheter 1. (a7) The surgeon pushes the needle catheter 2 with the stylet wire 3 inserted into it toward the distal end within the delivery lumen 1L of the delivery catheter 1. 10 , the stylet wire 3 protruding from the distal end opening 2a lifts the tip portion 21 (puncture needle) of the needle catheter 2, thereby functioning as a buffer member that prevents the tip portion 21 of the needle catheter 2 from contacting the inner circumferential surface 12i of the delivery catheter 1. This further reduces damage to the needle catheter 2 and the delivery catheter 1 when delivering the needle catheter 2. As shown in FIG. 10 , a gap is generated between the stylet wire 3 and the inner circumferential surface of the delivery catheter 1 due to the rigidity of the stylet wire 3.

[0059] (a8) After delivering the needle catheter 2 to just before the side opening 1c of the delivery catheter 1, the surgeon removes the stylet wire 3 from the needle catheter 2 as shown in Fig. 11 . Withdrawal of the stylet wire 3 causes the curved shape of the tip portion 21 of the needle catheter 2 (in other words, the shape of the curved portion 211), which had been gradually changed by the thickness of the stylet wire 3 and the gap between the stylet wire 3 and the inner circumferential surface of the delivery catheter 1, to return to its original shape by the thickness of the stylet wire 3 and the gap between the stylet wire 3 and the inner circumferential surface of the delivery catheter 1. When the surgeon further advances the tip portion 21 of the needle catheter 2 to the side opening 1c of the delivery catheter 1, the curved shape of the tip portion 21 completely returns to its original shape, and as a result, the tip portion 21 of the needle catheter 2 protrudes outward through the side opening 1c as shown in Fig. 12 . (a9) As shown in Figure 13, the surgeon pushes the needle catheter 2 in with the tip 21 (puncture needle) of the needle catheter 2 protruding from the side opening 1c. (a10) The surgeon attaches a syringe filled with a medicinal solution to the base end opening 2b of the needle catheter 2 and supplies the medicinal solution from the syringe into the lumen 2L. The medicinal solution passes through the lumen 2L and is ejected from the tip opening 2a into the myocardium 96. This allows the medicinal solution to be injected into the injection site (i.e., the area of ​​body tissue to be punctured).

[0060] In the needle catheter 2 of this embodiment, the intermediate section 22 has a lower rigidity than the distal section 21 and the proximal section 23. Furthermore, the proximal puncture section 202 has a lower rigidity than the distal puncture section 201, which includes the puncture needle. Therefore, during steps a5 to a7 and during insertion and delivery of the needle catheter 2 as shown in FIG. 10 , the intermediate section 22 and the proximal puncture section 202 bend (i.e., the intermediate section 22 and the proximal puncture section 202 function as buffer members), thereby maintaining the angle of the distal section 21 relative to the intermediate section 22 at a gentle angle that conforms to the delivery lumen 1L. The angle of the distal section 21 relative to the intermediate section 22 is, specifically, the angle of the distal puncture section 201 relative to the proximal puncture section 202. As a result, even when the delivery catheter 1 is significantly curved to follow the curved shape of a blood vessel, the needle catheter 2 can be smoothly advanced within the delivery lumen 1L. In the needle catheter 2 of this embodiment, the rigidity of the base end 23, which is closer to the surgeon's hand, is greater than the rigidity of the intermediate portion 22, thereby improving the pushability when advancing the needle catheter 2 in step a7.

[0061] In the needle catheter 2 of this embodiment, the rigidity of the tip section 21, including the puncture needle, is greater than the rigidity of the intermediate section 22. Therefore, the myocardium 96 can be easily punctured with the surgeon's pushing operation in step a9. Furthermore, in the needle catheter 2 of this embodiment, the rigidity of the proximal puncture section 202 is less than the rigidity of the distal puncture section 201, including the puncture needle. Therefore, as shown in FIG. 13 , the proximal puncture section 202, which has a lower rigidity, bends with the surgeon's pushing operation in step a9 (i.e., the proximal puncture section 202 functions as a buffer), allowing the myocardium 96 to be punctured more deeply while maintaining the inclination of the tip section 21 (puncture needle) punctured into the myocardium 96. The proximal puncture section 202 has lower sliding properties against body tissue than the distal puncture section 201. Therefore, when the myocardium 96 has been punctured up to the proximal puncture portion 202, the surgeon can easily recognize from the change in the feeling at his / her hand that the proximal puncture portion 202 has been punctured. The change in the feeling at the surgeon's hand means an increase in resistance at his / her hand.

[0062] The example shown in Figures 10 to 13 describes the procedure for a drug solution injection treatment using a stylet wire 3. However, the use of the stylet wire 3 may be omitted. In this case, the puncture needle system 1000 may be configured as a system including a delivery catheter 1 and a needle catheter 2 without the stylet wire 3. Even when the stylet wire 3 is omitted, the needle catheter 2 has a curved distal end surface 210. As described in Figure 8, this prevents contact between the distal end D and the inner circumferential surface 12i during delivery, thereby preventing damage to the delivery catheter 1 and the distal end portion 21 of the needle catheter 2. As described in Figure 6, the puncture portion 200 of the needle catheter 2 has a curved portion 211, and the distance S, which represents the bending width of the puncture needle, is greater than the inner diameter Φ1L of the delivery catheter 1. Therefore, when the distal end of the distal end portion 21 (puncture portion 200) is delivered to the side opening 1c, the distal end portion 21 can easily protrude outward from the side opening 1c.

[0063] As described above, the intermediate section 22 of the needle catheter 2 is located between the distal end section 21, which is a puncture needle, and the proximal end section 23, and can be advanced through a highly curved portion of the blood vessel within the delivery lumen 1L of the delivery catheter 1 previously inserted into the blood vessel ( FIG. 9 ). In this regard, according to the needle catheter 2 of the first embodiment, the rigidity of the intermediate section 22 is smaller than that of the distal end section 21 and the proximal end section 23, allowing the surgeon to smoothly advance the needle catheter 2 through a highly curved portion of the blood vessel. According to the needle catheter 2 of the first embodiment, the rigidity of the proximal end section 23, which is closer to the surgeon's hand, is greater than that of the intermediate section 22, improving pushability and allowing the surgeon to easily push the needle catheter 2. Furthermore, according to the needle catheter 2 of the first embodiment, the rigidity of the distal end section 21, which includes the puncture needle for puncturing body tissue, is greater than that of the intermediate section 22, allowing the body tissue (myocardium 96 in the example of FIG. 13 ) to be easily punctured. As a result, it is possible to provide a needle catheter 2 that can exhibit stable delivery properties regardless of the curved shape of the body lumen and can satisfactorily puncture the target puncture area of ​​body tissue.

[0064] In drug solution injection therapy, the puncture portion 200 is inserted into the myocardium 96 from inside the coronary arteries 94, 95 to inject drug solution. Therefore, the puncture needle of the needle catheter 2 used in drug solution injection therapy often has a curved shape as described in Fig. 6 . In this regard, according to the needle catheter 2 of the first embodiment, the rigidity of the proximal puncture portion 202 of the puncture portion 200 that punctures body tissue is lower than the rigidity of the distal puncture portion 201 including the puncture needle ( Fig. 6 ). Therefore, even when the delivery catheter 1 has the curved puncture needle described above, the proximal puncture portion 202, which has lower rigidity, bends (i.e., functions as a buffer member) within the delivery lumen 1L of the delivery catheter 1, allowing the puncture portion 200 to advance smoothly. Even when puncturing body tissue with the puncture section 200 exposed from the side opening 1c of the delivery catheter 1, the surgeon can push the needle catheter 2 while the puncture needle is still inserted into the body tissue, thereby bending the less rigid proximal puncture section 202 and allowing the puncture needle to puncture deeper into the body tissue while maintaining the inclination of the puncture needle inserted into the body tissue. As a result, the accuracy of puncturing the target area can be improved, and a needle catheter 2 can be provided that can more effectively puncture the target area of ​​the body tissue.

[0065] Furthermore, according to the needle catheter 2 of the first embodiment, the proximal puncture portion 202 has lower sliding properties relative to body tissue than the distal puncture portion 201, and therefore the puncture resistance of the proximal puncture portion 202 is higher than that of the distal puncture portion 201 ( FIG. 6 ). Therefore, when the proximal puncture portion 202 has been inserted into body tissue, the surgeon can easily tell from the change in feel at hand that the proximal puncture portion 202 has been inserted. As a result, the surgeon can be prevented from accidentally inserting the puncture portion 200 deeper than necessary. As a result, the accuracy and safety of puncturing the target area can be improved, and a needle catheter 2 can be provided that can more effectively puncture the target area of ​​body tissue.

[0066] Furthermore, according to the needle catheter 2 of the first embodiment, the puncture portion 200 has a curved portion 211 and a linear straight portion 212, and in a side view ( FIG. 6 ) in which the curved shape of the curved portion 211 can be seen, the distance S between the tip D and the line FL that defines the outer periphery of the intermediate portion 22 and is farther from the tip D is greater than the inner diameter Φ1L of the delivery catheter 1 into which the needle catheter 2 is inserted. Therefore, by using the needle catheter 2 of the first embodiment, the puncture portion 200 can be exposed from the side opening 1c of the delivery catheter 1 and the operation of puncturing body tissue can be easily performed during drug solution injection therapy.

[0067] Furthermore, according to the needle catheter 2 of the first embodiment, in a side view ( FIGS. 6 , 7 , and 8 ) in which the curved shape of the bending portion 211 can be confirmed, the distal end surface 210 of the puncture portion 200 is curved in the direction opposite to the bending direction of the bending portion 211. Therefore, when the puncture portion 200 is advanced within the delivery lumen 1L of the delivery catheter 1, the distal end D of the puncture portion 200 can be prevented from getting caught on the inner circumferential surface 12i of the delivery catheter 1. As a result, damage to the delivery catheter 1 and the puncture portion 200 during delivery can be prevented.

[0068] Furthermore, the first embodiment can provide a puncture needle system 1000 suitable for drug solution injection therapy, including a needle catheter 2 and a delivery catheter 1. According to the puncture needle system 1000 of the first embodiment, the delivery catheter 1 has a side opening 1c on the side of the delivery catheter 1, through which the tip portion 21 of the needle catheter 2 protrudes. This makes it easier to puncture the myocardium 96 from inside the coronary arteries 94, 95, compared to a configuration in which the tip portion 21 of the needle catheter 2 protrudes from the tip opening 1a of the delivery catheter 1.

[0069] 14 is an enlarged view of the vicinity of the distal end portion 21A of a needle catheter 2A of a second embodiment. In the second embodiment, an example will be described in which the rigidity and slidability against body tissue are different from those of the first embodiment. The needle catheter 2A of the second embodiment has the configuration described in the first embodiment, but includes a distal end portion 21A instead of the distal end portion 21 and an intermediate portion 22A instead of the intermediate portion 22.

[0070] The distal end portion 21A and the intermediate portion 22A constitute the puncturing portion 200A. The puncturing portion 200A has a distal end puncturing portion 201A consisting of the distal end portion 21A (puncture needle) and a proximal end puncturing portion 202A consisting of the marker 24 and a portion of the distal end of the intermediate portion 22A. In this embodiment, the rigidity of the proximal end puncturing portion 202A is the same as the rigidity of the distal end puncturing portion 201A (rigidity: distal end puncturing portion 201A = proximal end puncturing portion 202A). The proximal end puncturing portion 202A has the same sliding properties against body tissue as the distal end puncturing portion 201A (slidability: distal end puncturing portion 201A = proximal end puncturing portion 202A). The rigidity and sliding properties can be obtained by the method described in the first embodiment.

[0071] As described above, the configurations of the distal puncture section 201A and the proximal puncture section 202A can be modified in various ways, and the rigidity and slidability may be the same. The rigidity of the proximal puncture section 202A may be greater than the rigidity of the distal puncture section 201A. The proximal puncture section 202A may have greater slidability against body tissue than the distal puncture section 201A. The needle catheter 2A of the second embodiment described above can also achieve the same effects as the first embodiment described above.

[0072] <Third embodiment> Figure 15 is an enlarged view of the vicinity of the tip portion 21B of a needle catheter 2B of a third embodiment. In the third embodiment, a configuration in which the tip portion 21B is not curved will be described. The needle catheter 2B of the third embodiment has the configuration described in the first embodiment, but instead of the tip portion 21, it has a tip portion 21B. The tip portion 21B and the intermediate portion 22 form a puncture portion 200B. The puncture portion 200B does not have the curved portion 211 described in the first embodiment, and is entirely linear. In other words, the puncture portion 200B can also be said to be entirely straight.

[0073] As described above, the configurations of the tip section 21B and the puncture section 200B can be modified in various ways, and the puncture section 200B does not need to have a curved section 211. As described above, the puncture needle of the tip section 21B is formed of a metal with shape-memory properties. Therefore, with the needle catheter 2B of the third embodiment, prior to use in a procedure (FIGS. 10 to 13), the surgeon can deform the tip section 21B into a shape that is easy to perform the procedure by squeezing the tip section 21B (puncture needle) with a finger or the like. The surgeon may perform the procedure without bending the tip section 21B, in other words, while the tip section 21B remains straight. The needle catheter 2B of the third embodiment described above can also achieve the same effects as the first embodiment. Furthermore, the needle catheter 2B of the third embodiment can provide a needle catheter 2B that allows the operator to flexibly change the curvature and shape of the puncture needle depending on the surgeon's preferences and the type of procedure.

[0074] <Fourth embodiment> Figure 16 is an enlarged view of the vicinity of the tip portion 21C of a needle catheter 2C of a fourth embodiment. In the fourth embodiment, a configuration in which the shape of the tip surface 210C is different will be described. The needle catheter 2C of the fourth embodiment has a tip portion 21C instead of the tip portion 21 in the configuration described in the first embodiment. The tip portion 21C and the intermediate portion 22 form the puncture portion 200C. The puncture portion 200C has a tip surface 210C instead of the tip surface 210 described in the first embodiment. As shown in the enlarged view in the speech bubble on the left in Figure 16, the tip surface 210C is not curved. In other words, the cutting edge of the puncture needle at the tip portion 21C has a shape in which the needle tip is cut along one surface.

[0075] As described above, the configurations of the tip portion 21C and the puncture portion 200C can be modified in various ways, and the tip surface 210C of the puncture portion 200C does not have to be curved. The cutting edge of the puncture needle of the tip portion 21C can have any shape. For example, the needle tip may have a multifaceted cut shape, may be constricted, or may have a side hole. The side hole is a through hole different from the tip opening 2a. The needle catheter 2C of the fourth embodiment described above can also achieve the same effects as the first embodiment described above. The needle catheter 2C of the fourth embodiment can provide a wide variety of cutting edge shapes for the tip portion 21C.

[0076] Fifth Embodiment Figure 17 is a cross-sectional view of a needle catheter 2D of a fifth embodiment taken along line A-A. Figure 18 is a cross-sectional view of a needle catheter 2D of a fifth embodiment taken along line B-B. Figure 19 is a cross-sectional view of a needle catheter 2D of a fifth embodiment taken along line CC. In the fifth embodiment, an example will be described in which the configurations of an intermediate section 22D and a base end section 23D are different. The needle catheter 2D of the fifth embodiment has the configuration described in the first embodiment, except that it includes an intermediate section 22D instead of the intermediate section 22 and a base end section 23D instead of the base end section 23.

[0077] The intermediate section 22D has a shaft 225 instead of the coil body 221 and the tube 222 in the configuration described in the first embodiment. The shaft 225 is provided to improve the deliverability of the needle catheter 2D by imparting a predetermined rigidity and flexibility to the intermediate section 22D. The shaft 225 is a cylindrical member (tubular body) having an elongated outer shape. The shaft 225 is formed using a material with a relatively low rigidity among the materials of the shaft 231 exemplified in the first embodiment. The proximal end section 23D does not have the tube 222 in the configuration described in the first embodiment. The shaft 231 of the proximal end section 23D is formed using a material with a higher rigidity than the shaft 225. The shaft 225 and the shaft 231 have the same thickness. As a result, in the needle catheter 2D, the rigidity of the proximal end section 23D is greater than the rigidity of the intermediate section 22D. The shaft 225 is also referred to as the "distal shaft," and the shaft 231 is also referred to as the "proximal shaft."

[0078] As described above, the configuration of the intermediate section 22D and the proximal end section 23D can be modified in various ways, and the intermediate section 22D and the proximal end section 23D do not necessarily have to include a tube 222. As shown in FIGS. 17 to 19 , the intermediate section 22D and the proximal end section 23D may both be configured as tubular bodies. In the examples shown in FIGS. 17 to 19 , the intermediate section 22D and the proximal end section 23D are shown as different members formed of materials with different rigidities. However, the intermediate section 22D and the proximal end section 23D may be a single member formed of the same material. In this case, for example, the rigidity of the proximal end section 23D can be made greater than that of the intermediate section 22D by making the thickness of the portion corresponding to the intermediate section 22D thinner than the thickness of the portion corresponding to the proximal end section 23D. The needle catheter 2D of the fifth embodiment described above can also achieve the same effects as the first embodiment described above. The needle catheter 2D of the fifth embodiment allows for a simplified configuration of the intermediate section 22D and the proximal end section 23D.

[0079] <Modifications of this embodiment> The present disclosure is not limited to the above-described embodiment, and can be implemented in various forms without departing from the gist thereof. For example, the following modifications are also possible.

[0080] [Variation 1] The first to fifth embodiments described above show one example of the configuration of the puncture needle system 1000 and the needle catheters 2, 2A to 2D. However, the configuration of the puncture needle system 1000 and the needle catheters 2, 2A to 2D can be modified in various ways.

[0081] For example, the puncture needle system 1000 may be configured from the delivery catheter 1 and the needle catheter 2 without including the stylet wire 3. The puncture needle system 1000 may be configured to further include a combined device (e.g., a guiding catheter) not described above.

[0082] For example, the configuration of the delivery catheter 1 described above is merely one example, and various modifications are possible. For example, the delivery catheter 1 may be configured as a multi-lumen catheter. For example, the delivery catheter 1 may have a marker that allows the position of the side opening 1c to be recognized under X-ray images. For example, the configuration of the stylet wire 3 described above is merely one example, and various modifications are possible. For example, the stylet wire 3 may be composed of only a core wire and may not have a coil body. For example, the stylet wire 3 may have additional components, such as a distal tip or a marker.

[0083] Figure 20 is a cross-sectional view of a modified needle catheter taken along line CC. In the first embodiment, an example was described in which the coil body 221 is not present at the proximal end 23 of the needle catheter 2. As shown in Figure 20, the coil body 221 may be present at the proximal end 23 of the needle catheter 2. In this case, the proximal end of the coil body 221 is joined to the proximal end of the tube 222 and the proximal end of the shaft 231 inside the connector 29. In other words, as shown in Figure 20, the tube 222, the coil body 221, and the shaft 231 are layered from the inside to the outside at the proximal end 23 of the needle catheter 2. This configuration can also achieve the same effects as the above-mentioned embodiments.

[0084] For example, the needle catheter 2 may not have the marker 24. For example, the needle catheter 2 may be provided with a plurality of markers indicating the puncture depth on the distal end portion 21 and a portion of the distal end side of the intermediate portion 22. The plurality of markers are arranged in a scale pattern at regular intervals. The surgeon can easily grasp the puncture depth by checking the plurality of markers under an X-ray image.

[0085] For example, in the needle catheter 2, the length of the intermediate section 22 in the longitudinal direction (the length of section S22) and the length of the base end section 23 (the length of section S23) are approximately equal. The length of the intermediate section 22 may be shorter than the length of the base end section 23. This will further improve the torque transmission properties of the needle catheter 2. The length of the intermediate section 22 may be longer than the length of the base end section 23. This will further improve the flexibility of the needle catheter 2. For example, the outer circumferential surface of the needle catheter 2 may be coated with a hydrophilic resin or a hydrophobic resin. This will improve the slidability of the needle catheter 2 inside the delivery catheter 1. For example, the inner circumferential surface of the needle catheter 2 may be coated with a resin that has excellent chemical resistance.

[0086] [Variation 2] The configurations of the puncture needle system 1000 and the needle catheters 2, 2A-2D of the first to fifth embodiments and the configuration of the puncture needle system 1000 and the needle catheters 2, 2A-2D of Variation 1 may be combined as appropriate. For example, the needle catheter 2 may be configured by combining any of the distal end sections 21A-21C described in the second to fourth embodiments with the intermediate section 22D and the proximal end section 23D described in the fifth embodiment. For example, the needle catheter 2 may be configured by arbitrarily combining two or more of the rigidity and slidability described in the second embodiment, the straight puncture needle described in the third embodiment, and the shape of the distal end surface 210C described in the fourth embodiment.

[0087] This aspect has been described above based on embodiments and modifications. The above-described embodiments of the aspect are intended to facilitate understanding of this aspect and are not intended to limit this aspect. This aspect may be modified or improved without departing from the spirit and scope of the claims, and equivalents thereof are included in this aspect. If a technical feature is not described as essential in this specification, it may be deleted as appropriate.

Claims

1. A needle catheter (2, 2A to 2D) comprising: a hollow tip portion (21, 21A to 21C) made of a puncture needle; a hollow intermediate portion (22, 22A, 22D) provided contiguous with the tip portion (21, 21A to 21C) on the proximal side of the tip portion (21, 21A to 21C); and a hollow base end portion (23, 23D) provided contiguous with the intermediate portion (22, 22A, 22D) on the proximal side of the intermediate portion (22, 22A, 22D), wherein the rigidity of the tip portion (21, 21A to 21C) is greater than the rigidity of the intermediate portion (22, 22A, 22D), and the rigidity of the base end portion (23, 23D) is greater than the rigidity of the intermediate portion (22, 22A, 22D).

2. A needle catheter (2, 2B to 2D) according to claim 1, comprising a puncturing section (200, 200B, 200C) including the tip section (21, 21B, 21C) and a portion of the tip side of the intermediate section (22, 22D), the puncturing section (200, 200B, 200C) being inserted into body tissue, the puncturing section (200, 200B, 200C) comprising a tip-side puncturing section (201) including the puncture needle and a base-side puncturing section (202) provided contiguous with the tip-side puncturing section (201), the rigidity of the base-side puncturing section (202) being less than the rigidity of the tip-side puncturing section (201).

3. A needle catheter (2, 2B to 2D) according to claim 2, wherein the base end puncture portion (202) has lower sliding properties against body tissue than the tip end puncture portion (201).

4. A needle catheter (2, 2A, 2C, 2D) according to claim 2 or 3, wherein the puncture section (200, 200A, 200C) has a curved section (211) and a linear straight section (212) that is continuous with the curved section (211) and is located proximal to the curved section (211), and wherein, in a side view in which the curved shape of the curved section (211) can be seen, the distance from the tip D of the puncture section (200, 200A, 200C) to the side of a line defining the outer periphery of the intermediate section (22, 22A, 22D) that is farther from the tip D is greater than the inner diameter of a delivery catheter (1) into which the needle catheter (2, 2A, 2C, 2D) is inserted.

5. A needle catheter (2, 2A, 2B, 2D) according to claim 4, wherein the puncture section (200, 200A, 200B) has a distal end surface at its distal end, and in a side view in which the curved shape of the curved section (211) can be seen, the distal end surface is curved in the opposite direction to the curved direction of the curved section (211).

6. A needle catheter (2, 2A, 2B, 2D) according to claim 5, wherein when the needle catheter (2, 2A, 2B, 2D) is inserted into the delivery catheter (1) and the angle of incidence α of the puncture portion (200, 200A, 200B) with respect to the inner circumferential surface of the delivery catheter (1) is greater than 0° and less than 10°, the angle of inclination β of the tip surface of the puncture portion (200, 200A, 200B) with respect to the inner circumferential surface of the delivery catheter (1) is greater than 0°.

7. A puncture needle system comprising: a needle catheter (2, 2A to 2D) according to any one of claims 1 to 6; and a delivery catheter (1) into which the needle catheter (2, 2A to 2D) is inserted, wherein the delivery catheter (1) has a lumen into which the needle catheter (2, 2A to 2D) is inserted, and a side opening (1c) provided on the side of the delivery catheter (1) that connects the lumen to the outside, and wherein when the needle catheter (2, 2A to 2D) is inserted into the delivery catheter (1) and the tip end portion (21, 21A to 21C) is pushed up to the side opening, the tip end portion (21, 21A to 21C) protrudes from the side opening (1c).

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