Puncture needle system and puncture needle unit

Abstract

This puncture needle system includes: a delivery catheter that comprises a first hollow shaft having a first lumen therein, and that is provided with a lateral surface opening communicating between the first lumen and the outside on a lateral surface of the first hollow shaft; a needle catheter that comprises a hollow puncture needle having a curved section at a tip section and a tip opening at the tip, and that comprises a second hollow shaft continuing to a puncture needle, disposed closer to a base end side than the puncture needle, communicating with the inside of the puncture needle, and having therein a second lumen communicating with the outside via the tip opening; and a stylet wire. The needle catheter is pushed forward in the first lumen toward the tip side of the delivery catheter in an insertion state in which the stylet wire is inserted into the second lumen and protrudes from the tip opening, and then the stylet wire is removed from inside the second lumen, thereby causing the puncture needle to protrude to the outside from the lateral surface opening.

Description

Lancing needle system and puncture needle unit

[0001] The present disclosure relates to a puncture needle system and a puncture needle unit.

[0002] Puncture of body tissue using an instrument having a puncture needle has been performed in the past. For example, Patent Document 1 discloses an instrument having a puncture needle, which is a catheter configured so that the diameter of the puncture tip is smaller than the diameter of the body on the base end. Patent Document 2 discloses a puncture instrument designed to reliably puncture the dermis with the puncture needle.

[0003] JP 2008-43445 A JP 2007-117392 A

[0004] The instruments described in Patent Documents 1 and 2 do not take into consideration use in treatments in which a medicinal solution is injected into body tissue from within a living lumen, and therefore there has been a demand for a technology that enables good puncture of body tissue while achieving both efficiency and safety in such treatments.

[0005] The present disclosure has been made to solve at least some of the above-mentioned problems, and aims to provide a puncture needle system that is capable of effectively puncturing body tissue while achieving both procedural efficiency and safety in treatments in which a medicinal solution is injected into body tissue from within a biological lumen.

[0006] The present disclosure has been made to solve at least part of the above-mentioned problems, and can be realized in the following aspects.

[0007] (1) According to one aspect of the present disclosure, there is provided a puncture needle system including: a needle catheter including a first hollow shaft having a first lumen therein, the first hollow shaft having a side opening in a side surface thereof that communicates with the first lumen and the outside, a hollow puncture needle having a curved portion at a distal end and a distal opening at the distal end, and a second hollow shaft that is continuous with the puncture needle and is positioned proximal to the puncture needle, the second hollow shaft having a second lumen therein that communicates with the interior of the puncture needle and with the outside via the distal opening, and a stylet wire, wherein the needle catheter is pushed through the first lumen toward the distal end of the delivery catheter in an inserted state in which the stylet wire is inserted into the second lumen and protrudes from the distal opening, and then the stylet wire is withdrawn from the second lumen, causing the puncture needle to protrude from the side opening to the outside.

[0008] This configuration allows the needle catheter to be placed in an inserted state in which the stylet wire is inserted into the second lumen and protrudes from the distal end opening. When the inserted needle catheter is advanced toward the distal end of the delivery catheter, the stylet wire protruding from the distal end opening functions as a buffer to prevent the puncture needle from contacting the inner circumferential surface of the delivery catheter. This reduces damage to the puncture needle and the delivery catheter during delivery of the needle catheter. By removing the stylet wire from the second lumen after the inserted needle catheter reaches the vicinity of the side opening, the curve of the puncture needle, which had been softened by the insertion of the stylet wire, returns to its original shape, making it easier for the puncture needle to protrude from the side opening to the outside of the delivery catheter. Therefore, this configuration provides a puncture needle system that enables satisfactory puncture of body tissue while achieving both efficient and safe procedures.

[0009] (2) In the puncture needle system of the above aspect, the stylet wire may have a first section including the tip and a second section continuous with the first section and positioned proximal to the first section, wherein the outer diameter of the stylet wire in the second section is greater than half the inner diameter of the tip of the puncture needle and less than the inner diameter of the tip. With this configuration, in the inserted state, the clearance between the outer surface of the stylet wire in the second section and the inner surface of the puncture needle is reduced, thereby reducing the range over which the puncture needle can move around the stylet wire in the second section. This prevents the tip of the puncture needle from moving too far away from the stylet wire and coming into contact with the inner surface of the delivery catheter. As a result, damage to the puncture needle and the delivery catheter can be further reduced when the needle catheter is delivered.

[0010] (3) In the puncture needle system of the above aspect, in a side view in which the curved shape of the curved portion can be confirmed, the distance between the distal end of the needle catheter and one of the lines defining the outer periphery of the second hollow shaft farthest from the distal end of the needle catheter may be greater than the inner diameter of the delivery catheter, and when the needle catheter in the inserted state is inserted into the first lumen, a gap may be formed between the center of the distal end opening and the inner circumferential surface of the delivery catheter. With this configuration, the curved portion of the puncture needle is gently curved in the inserted state, so that when the inserted needle catheter is advanced toward the distal end of the delivery catheter within the first lumen, the force pushing the base end of the needle catheter toward the distal end can be prevented from being directed in a direction in which the distal end of the needle catheter pushes against the inner circumferential surface of the delivery catheter. Therefore, the inserted needle catheter can be easily advanced toward the distal end within the first lumen, improving the efficiency of the procedure.

[0011] (4) In the puncture needle system of the above aspect, in a side view in which the curved shape of the curved portion can be confirmed, the distance between the distal end of the needle catheter and one of the lines defining the outer periphery of the second hollow shaft, which is farthest from the distal end of the needle catheter, may be greater than the inner diameter of the delivery catheter, and when the needle catheter in the inserted state is inserted into a transparent member having a cylindrical space formed therein with an inner diameter the same length as the inner diameter of the first lumen, a gap may be formed between the center of the distal end opening and the inner circumferential surface of the delivery catheter. With this configuration, the curved portion of the puncture needle is gently curved in the inserted state, so that when the inserted needle catheter is advanced toward the distal end of the delivery catheter within the first lumen, the force pushing the base end of the needle catheter toward the distal end can be prevented from being directed in the direction of the distal end of the needle catheter pushing against the inner circumferential surface of the delivery catheter. Therefore, the inserted needle catheter can be easily advanced toward the distal end within the first lumen, improving the efficiency of the procedure.

[0012] (5) In the puncture needle system of the above aspect, the stylet wire may have a first section including a distal end and a second section continuous with the first section and located proximal to the first section, and the rigidity of at least the first and second sections of the stylet wire may be greater than 1 / 50 of the rigidity of the puncture needle but less than the rigidity of the puncture needle. With this configuration, the curved portion of the puncture needle is gently curved in the inserted state. Therefore, when the inserted needle catheter is advanced toward the distal end of the delivery catheter within the first lumen, the force pushing the proximal end of the needle catheter toward the distal end can be prevented from being directed in a direction where the distal end of the needle catheter pushes against the inner circumferential surface of the delivery catheter. Therefore, the inserted needle catheter can be easily advanced toward the distal end within the first lumen, improving the efficiency of the procedure.

[0013] (6) In the puncture needle system of the above aspect, the stylet wire may have a first section including a tip and a second section continuous with the first section and located proximal to the first section, and may further include a core wire, a coil body surrounding the core wire in the first and second sections, and a hemispherical tip joint joining the tip of the core wire to the tip of the coil body. With this configuration, even if at least the portion of the stylet wire corresponding to the first section protrudes out of the delivery catheter through the side opening when the inserted needle catheter is pushed toward the distal end of the delivery catheter within the first lumen, damage to body tissue can be suppressed because the portion is composed of a flexible core wire and coil body and a hemispherical tip joint. With this configuration, the portion of the stylet wire corresponding to the second section is provided with a coil body, and therefore longitudinal misalignment between the needle catheter and the stylet wire in the inserted state due to unevenness on the outer circumferential surface of the coil body can be suppressed. Therefore, the needle catheter in the inserted state, which is less likely to slip longitudinally relative to the stylet wire, can be easily pushed forward toward the distal end within the first lumen, thereby achieving both greater efficiency and safety in the procedure.

[0014] (7) In the puncture needle system of the above aspect, the outer diameter of the core wire in the second section may be greater than one-third of the inner diameter of the tip of the puncture needle and less than the inner diameter of the tip. With this configuration, in the inserted state, the clearance between the outer surface of the stylet wire in the second section (the outer surface of the section where the core wire is surrounded by the coil) and the inner surface of the puncture needle is reduced, thereby narrowing the range over which the puncture needle can move around the stylet wire in the second section. This prevents the tip of the puncture needle from moving too far away from the stylet wire and coming into contact with the inner surface of the delivery catheter. As a result, damage to the puncture needle and the delivery catheter during delivery of the needle catheter can be further reduced.

[0015] (8) In the puncture needle system of the above aspect, the coil body in the first section may be provided with a radiopaque marker. With this configuration, by checking the position of the marker under an angio image, the position of the first section of the stylet wire in the inserted needle catheter can be easily determined, thereby improving the efficiency of the procedure.

[0016] (9) According to another aspect of the present disclosure, a puncture needle unit is provided. The puncture needle unit includes a needle catheter including a hollow puncture needle having a curved portion at its distal end and a distal opening at its distal end, a hollow shaft connected to the puncture needle and positioned proximal to the puncture needle, and having an internal lumen communicating with the interior of the puncture needle and communicating with the outside via the distal opening, and a stylet wire, wherein the stylet wire is inserted into the lumen, protruding from the distal opening, and removable from the lumen. This configuration allows the needle catheter to be placed in an insertion state in which the stylet wire is inserted into the lumen and protruding from the distal opening. In this insertion state, the curve of the curved portion of the puncture needle is gentle, making it easier to insert the needle catheter into a delivery catheter. When the inserted needle catheter is advanced toward the distal end of the delivery catheter, the stylet wire protruding from the distal opening functions as a buffer to prevent the puncture needle from contacting the inner circumferential surface of the delivery catheter. This reduces damage to the puncture needle and the delivery catheter when delivering the needle catheter. By removing the stylet wire from the lumen after the inserted needle catheter reaches the vicinity of the side opening of the delivery catheter, the curve of the puncture needle, which had been softened by the insertion of the stylet wire, returns to its original shape, making it easier for the puncture needle to protrude outward from the side opening. Therefore, this configuration provides a puncture needle unit that enables good puncture of body tissue while achieving both efficient and safe procedures.

[0017] The present disclosure can be realized in various forms, such as a delivery catheter, a needle catheter, a stylet wire, a puncture needle unit including a delivery catheter and a needle catheter, and a method for manufacturing these.

[0018] 3 is an explanatory diagram illustrating the configuration of the puncture needle system of the first embodiment. FIG. 3 is an explanatory diagram illustrating the configuration of a needle catheter. FIG. 4 is a cross-sectional view of each part of FIG. 2. FIG. 4 is a cross-sectional view of each part of FIG. 2. FIG. 4 is a cross-sectional view of each part of FIG. 2. FIG. 4 is an enlarged view of the vicinity of the puncture needle of the needle catheter. FIG. 5 is an explanatory diagram showing the needle catheter with a stylet wire inserted. FIG. 6 is a diagram showing the state of the heart during a drug solution injection treatment procedure. FIG. 7 is an explanatory diagram showing the procedure of the drug solution injection treatment procedure. FIG. 8 is an explanatory diagram showing the procedure of the drug solution injection treatment procedure. FIG. 9 is an explanatory diagram showing the procedure of the drug solution injection treatment procedure. FIG. 10 is an explanatory diagram showing the procedure of the drug solution injection treatment procedure. FIG. 11 is an explanatory diagram showing the vicinity of the tip of the needle catheter 2 in an inserted state. FIG. 12 is an explanatory diagram showing a state in which no gap is formed in a puncture needle system of a comparative example. FIG. 13 is an explanatory diagram showing the needle catheter in an inserted state inserted into a member. FIG. 14 is an explanatory diagram illustrating a longitudinal section of the stylet wire of a second embodiment. FIG. 15 is an explanatory diagram showing the needle catheter in an inserted state inserted into a member. FIG. 16 is a cross-sectional view of a base-end shaft.

[0019] First Embodiment FIG. 1 is an explanatory diagram illustrating the configuration of a puncture needle system 1000 according to a first embodiment. FIG. 1 illustrates the configuration of a delivery catheter 1. FIG. 1 illustrates the configuration of a needle catheter 2. FIG. 1 illustrates the configuration of a stylet wire 3. The puncture needle system 1000 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 bodily tissue. Hereinafter, a drug solution injection therapy will be described as an example of a specific application scenario for 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 prepared by culturing and inducing differentiation of stem cells is injected into the myocardium via a coronary artery.

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

[0022] The distal tip 11 is continuous with the first hollow shaft 12 and is positioned distal to the first hollow shaft 12, moving through the blood vessel ahead of other components. The distal tip 11 is a cylindrical member with an outer diameter that gradually decreases from the base 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 first hollow shaft 12 is a cylindrical member (tubular body) having a first lumen 1L therein and an elongated outer shape. The first hollow shaft 12 includes a distal shaft 12D and a proximal shaft 12P. A side opening OP, which is a through-hole connecting the first lumen 1L to the outside, is provided on the side surface of the distal shaft 12D. The side opening OP is an opening through which the distal end of the needle catheter 2 protrudes from the delivery catheter 1. The shape of the side opening OP as viewed from the -Y axis direction is substantially rectangular. The shape of the side opening OP as viewed from the -Y axis direction may be any shape (e.g., circular, square, polygonal). A radiopaque marker M is provided on the side surface of the distal shaft 12D near the side opening OP. The marker M is provided to surround the outer edge of the side opening OP under X-ray images (angio images) and functions as a guide to confirm the orientation of the side opening OP. A distal tip 11 is fixed to the distal end of the distal shaft 12D. A connector 19 is fixed to the proximal end of the proximal shaft 12P. In this embodiment, the length Lo from the distal end of the side opening OP to the proximal end of the distal tip 11 is 10 mm.

[0024] The connector 19 is continuous with the first hollow shaft 12 and is positioned closer to the proximal end than the first hollow 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 (e.g., a workhorse wire) into the delivery catheter 1.

[0025] As shown by dashed lines in Figure 1, the distal tip 11, first hollow shaft 12, and connector 19 are formed with a first lumen 1L that connects the interiors of each section along the longitudinal direction of the delivery catheter 1. The first lumen 1L is a lumen into which the needle catheter 2 or other devices are inserted. The inner diameter Φ1L of the first lumen 1L may be determined arbitrarily as long as it is larger than the outer diameter of the second hollow shaft 22 of the needle catheter 2. The base end of the first lumen 1L is connected to the outside through a base end opening 1b. The tip of the first lumen 1L is connected to the outside through a tip opening 1a. The tip of the first lumen 1L is connected to the outside through a side opening OP.

[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, it 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, it can be formed from gold, platinum, tungsten, or an alloy containing these elements (e.g., platinum-nickel alloy). The first hollow shaft 12 and the connector 19 can be formed from known materials, such as nylon resins such as polyamide; polyolefins such as polyethylene, polypropylene, and ethylene-propylene copolymers; polyesters such as polyethylene terephthalate; thermoplastic resins such as polyvinyl chloride, ethylene-vinyl acetate copolymers, cross-linked ethylene-vinyl acetate copolymers, and polyurethane; polyamide elastomers; polyolefin elastomers; polyurethane elastomers; silicone rubber; and latex rubber.

[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 puncture needle 21, a second hollow shaft 22, a marker 24, a connector 29, and a cap CP. The needle catheter 2 of this embodiment is a single-lumen catheter with one needle.

[0028] The puncture needle 21 is the distal end of the needle catheter 2 and is a hollow puncture needle that is continuous with the second hollow shaft 22 and is positioned distal to the second hollow shaft 22. The puncture needle 21 may be integral with the second hollow shaft 22 or may be separate from the second hollow shaft 22. The puncture needle 21 is also simply referred to as a "needle." The puncture needle 21 has an outer diameter that gradually decreases from the base end to the distal end, while its inner diameter is constant. The distal end of the puncture needle 21 has a sharp shape to facilitate puncturing body tissue. The puncture needle 21 has a curved portion 211 at its distal end that is curved in a specific direction (the -Y-axis direction in the illustrated example) (see FIG. 6 ). A distal end opening 2a is provided at the distal end of the puncture needle 21. The distal end opening 2a is used to project the stylet wire 3 during delivery of the needle catheter 2 and to eject the medicinal solution during medicinal solution injection through the needle catheter 2.

[0029] The second hollow shaft 22 is continuous with the puncture needle 21 and is positioned proximal to the puncture needle 21. It has a second lumen 2L inside and is a cylindrical member (tubular body) with an elongated outer shape. The second hollow shaft 22 includes a distal shaft 22D and a proximal shaft 22P. The distal shaft 22D and the proximal shaft 22P both have a constant outer diameter. As shown in the figure, the outer diameter of the distal shaft 22D is the same as the outer diameter of the proximal shaft 22P. In this embodiment, "same" and "equal" do not necessarily mean exact agreement, but also mean allowing for differences due to manufacturing errors and the like. "Constant" is synonymous with "approximately constant" and means being approximately constant while allowing for variations due to manufacturing errors and the like.

[0030] The marker 24 functions as a guide to enable confirmation of the position of the puncture needle 21 under an angiographic image. The marker 24 is an annular member provided between the puncture needle 21 and the distal shaft 22D, specifically, at the tip of the distal shaft 22D. The marker 24 may have any shape other than an annular shape, or may be omitted.

[0031] Connector 29 is continuous with proximal shaft 22P and is positioned closer to the proximal end than proximal shaft 22P, making it easier for the surgeon to grasp the device. Connector 29 is a generally cylindrical member provided with a pair of wings. A proximal opening 2b is formed at the proximal end of connector 29. Proximal opening 2b is used to insert stylet wire 3 during delivery of needle catheter 2, and is used to attach a syringe for supplying medicinal liquid during medicinal liquid injection through needle catheter 2.

[0032] As shown by dashed lines in FIG. 1 , the puncture needle 21, the second hollow shaft 22, and the connector 29 are formed with a second lumen 2L that connects the interiors of each part along the longitudinal direction of the needle catheter 2. The second lumen 2L is a lumen for inserting the stylet wire 3 and also a lumen for circulating a medicinal solution. The inner diameter Φ2L of the second 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 second lumen 2L communicates with the outside through a distal end opening 2a. The proximal end of the second lumen 2L communicates with the outside through a proximal end opening 2b. In other words, the second lumen 2L connects the interior of the second hollow shaft 22 with the interior of the puncture needle 21, and also connects the interior of the second hollow shaft 22 with the outside via the distal end opening 2a.

[0033] The cap cp is a cylindrical member that can be attached so as to cover the outer peripheral surface of the proximal end of the connector 29. A female thread (not shown) is formed on the inner peripheral surface of the cap cp, and a male thread (not shown) is formed on the outer peripheral surface of the proximal end of the connector 29. When the stylet wire 3 is inserted into the second lumen 2L, the inner diameter of the proximal end opening 2b, which decreases depending on how tightly the cap cp is tightened, presses against the outer peripheral surface of the stylet wire 3, thereby fixing the stylet wire 3 to the needle catheter 2.

[0034] 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 the delivery of the needle catheter 2. As shown in FIG. 1 , the stylet wire 3 includes a core wire 31.

[0035] The core wire 31 is a cylindrical member having an elongated outer shape. The core wire 31 has a constant outer diameter. Details of the first section S1 and the second section S2 shown in FIG. 1 will be described later with reference to FIG. 7.

[0036] The core wire 31 can be made of materials such as stainless steel alloys such as SUS302, SUS304, and SUS316, superelastic alloys such as NiTi (nickel-titanium) alloys, piano wire, nickel-chromium alloys, cobalt alloys, tungsten, etc. The core wire 31 may also be made of known materials other than those mentioned above.

[0037] In the puncture needle system 1000, of the tip portion of the delivery catheter 1 (tip 11), the tip portion of the needle catheter 2 (tip portion of the puncture needle 21), and the tip portion of the stylet wire 3 (tip portion of the core wire 31), the tip portion of the needle catheter 2 (tip portion of the puncture needle 21) has the highest rigidity, and the tip portion of the stylet wire 3 (tip portion of the core wire 31) has the lowest rigidity.

[0038] FIG. 2 is an explanatory diagram illustrating the configuration of the needle catheter 2. FIGS. 3 to 5 are cross-sectional views of the various parts of FIG. 2. FIG. 3 shows a cross-section taken along line F3-F3 in FIG. 2. FIG. 4 shows a cross-section taken along line F4-F4 in FIG. 2. FIG. 5 shows a cross-section taken along line F5-F5 in FIG. 2. In FIGS. 2 to 5, the central axis of the second hollow shaft 22 is shown as axis O (dotted chain line). The X, Y, and Z axes in FIGS. 2 to 5 correspond to each other. The configuration of the needle catheter 2 will be described in detail below.

[0039] The puncture needle 21 is the portion located at the most distal end of the needle catheter 2. At the base end of the puncture needle 21, the center of the puncture needle 21 coincides with the axis O. At the distal end of the puncture needle 21, the distal end portion of the puncture needle 21 is a curved portion 211 (see FIG. 6 ), so the center of the puncture needle 21 is inclined with respect to the axis O. The puncture needle 21 can be formed from a metal having shape memory properties, such as a NiTi alloy or a CuZnAl alloy.

[0040] As shown in FIG. 4 , the distal shaft 22D of the second hollow shaft 22 includes a coil body 221 and a tube 222 .

[0041] 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 puncture needle 21 from the proximal end side. The proximal end of the tube 222 is joined to the distal end 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.

[0042] The coil body 221 is provided to impart a predetermined rigidity and flexibility to the tube 222 in the distal shaft 22D, 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 puncture needle 21, respectively. The proximal end of the coil body 221 is bonded to the tube 222 and the distal end of the shaft 231, described below, 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 adhesive such as epoxy adhesive or cyanoacrylic adhesive. Bonding may be performed using two or more methods in combination.

[0043] The coil body 221 can be formed from, for example, stainless steel alloys such as SUS304 and SUS316, superelastic alloys such as NiTi alloys, radiolucent alloys such as piano wire, nickel-chromium alloys, and cobalt alloys, radiopaque alloys such as gold, platinum, tungsten, and alloys containing these elements (e.g., platinum-stainless steel alloys and platinum-nickel alloys), or other known materials. The coil body 221 may be a single-strand coil formed by winding a single wire, a single-strand stranded coil formed by winding a single strand of a twisted wire obtained by twisting multiple wires together, or a multi-strand stranded coil formed by using multiple twisted wires obtained by twisting multiple wires together and winding each twisted wire multiple times.

[0044] 5, the proximal shaft 22P of the second hollow shaft 22 has a shaft 231 and a tube 222. The tube 222 is the same member as the tube 222 described with reference to FIG.

[0045] The shaft 231 is provided to impart a predetermined rigidity and torque transmission capability to the tube 222 in the proximal shaft 22P, 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.

[0046] The shaft 231 can be made of a known material, for example, a stainless steel alloy such as SUS302, SUS304, or SUS316, or a superelastic alloy such as a NiTi alloy. In the needle catheter 2 of this embodiment, the length of the distal shaft 22D in the longitudinal direction is approximately equal to the length of the proximal shaft 22P.

[0047] 6 is an enlarged view of the vicinity of the puncture needle 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 puncture needle 21 but also a portion of the distal end of the distal shaft 22D is inserted into the body tissue. In this way, the portion of the needle catheter 2 that is inserted into the body tissue is also referred to as the "puncture portion 200." As described above, the puncture portion 200 includes the puncture needle 21 and a portion of the distal end of the distal shaft 22D.

[0048] The distal end of puncturing section 200 is curved section 211. The proximal end of puncturing section 200 is defined by straight section 212, which is a linear section along axis O. Straight section 212 is provided continuous with curved section 211 from the proximal end.

[0049] 6 is a diagram 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 in which the length of distance S, described below, is the longest and the puncture needle 21 and the distal shaft 22D can be confirmed (the Z-axis direction in FIG. 6 ). In this side view, the tip of the distal end surface 210 of the puncture needle 21 is referred to as the distal end D. Here, the distance S between the distal end D and a line FL that defines the outer periphery of the second hollow shaft 22 farther from the distal end 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 (the line on the +Y-axis direction and the line on the −Y-axis direction) that define the outer periphery of the second hollow shaft 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 second hollow shaft 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, which is an imaginary extension of line FL toward the tip side, intersects with a perpendicular line VD drawn from the tip D to the virtual line PL. In other words, the distance S represents the bending width of the puncture needle 21. The line T-T shown in FIG. 6 will be used in the description of FIG. 7 .

[0050] FIG. 7 is an explanatory diagram showing the needle catheter 2 with the stylet wire 3 inserted into the second lumen 2L. In FIG. 7, the stylet wire 3 inserted into the second lumen 2L is represented by a solid line and hatching to make it easier to see. Because the clearance between the inner circumferential surface of the second lumen 2L and the outer circumferential surface of the stylet wire 3 is very small, the dashed line representing the second lumen 2L in FIGS. 1 and 6 overlaps with the solid line representing the stylet wire 3 in FIG. 7. Hereinafter, the state in which the stylet wire 3 is inserted into the second lumen 2L and protrudes from the distal opening 2a of the needle catheter 2, as shown in FIG. 7, will be referred to as the "insertion state." In the puncture needle system 1000, when injecting a medicinal solution into cardiomyocytes, the needle catheter 2 in the insertion state is inserted through the proximal opening 1b of the delivery catheter 1 inserted into a biological lumen.

[0051] 1 and 7 , the stylet wire 3 has a first section S1 including the distal end, and a second section S2 that is continuous with the first section S1 and is located proximal to the first section S1. The first section S1 corresponds to the portion of the stylet wire 3 that is intended to protrude from the distal opening 2 a of the needle catheter 2 in the inserted state. The second section S2 corresponds to the portion of the stylet wire 3 that is intended to be located inside the puncture needle 21 in the inserted state. In other words, it corresponds to the portion of the stylet wire 3 that extends from the proximal end of the first section S1 to the proximal end and is included within the length of the second lumen 2L (the portion from the distal surface 210 to the marker 24) formed within the puncture needle 21. A marker may be provided between the first section S1 and the second section S2 of the stylet wire 3 to indicate the boundary between them.

[0052] In the inserted needle catheter 2, the length Ls of the portion of the stylet wire 3 protruding from the distal opening 2a (the portion corresponding to the first section S1) is assumed to be 10 mm or less. As described with reference to FIG. 1 , in this embodiment, the length Lo from the distal end of the side opening OP to the rear end of the distal tip 11 is 10 mm. In drug solution injection therapy using the puncture needle system 1000, when drug solution is injected into cardiomyocytes, it is assumed that the delivery catheter 1 is delivered until the side opening OP reaches the vicinity of the drug solution injection site, and then the distal end of the puncture needle 21 of the inserted needle catheter 2 is delivered within the delivery catheter 1 to just before the side opening OP. Therefore, the length Ls is set to be equal to or less than the length Lo so that the stylet wire 3 does not protrude from the distal opening 1a of the delivery catheter 1 at this time.

[0053] The outer diameter of the stylet wire 3 in the second section S2 is greater than half the inner diameter of the tip of the puncture needle 21, but is smaller than the inner diameter of the tip of the puncture needle 21. The inner diameter of the tip of the puncture needle 21 refers to the inner diameter in a cross section taken along line T-T in Figure 6 (the inner diameter of the most distal cross section of the puncture needle 21 at a position where the second lumen 2L is not missing). In this embodiment, the stylet wire 3 is a core wire 31 having a constant outer diameter, and the inner diameter of the puncture needle 21 is also constant, so the outer diameter of the stylet wire 3 over its entire length is greater than half the inner diameter of the puncture needle 21, but is smaller than the inner diameter of the puncture needle 21. By designing the length of the outer diameter of the stylet wire 3 in the second section S2 in this manner, the clearance between the inner surface of the puncture needle 21 and the outer surface of the stylet wire 3 is reduced when inserted, thereby reducing the range over which the puncture needle 21 can move around the stylet wire 3.

[0054] Figure 8 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 from a left coronary artery 94 of a heart 90 into a myocardium 96 (see Figures 9 to 12) is illustrated. Figure 8 shows the heart 90, and the guiding catheter 4, delivery catheter 1, and needle catheter 2 inserted into the heart 90. For ease of explanation, in Figure 8, the guiding catheter 4 is represented by a dashed line and the delivery catheter 1 is represented by a solid line.

[0055] Figures 9 to 12 are explanatory diagrams showing the procedure for drug solution injection therapy. Figure 9 shows the state in which the needle catheter 2 is delivered by the delivery catheter 1. Figure 10 shows the state in which the stylet wire 3 is removed. Figure 11 shows the state in which the needle catheter 2 is protruded from the delivery catheter 1. Figure 12 shows the state in which the needle catheter 2 is inserted into the myocardium 96. For ease of explanation, in Figures 9 to 12, the needle catheter 2 inserted into the first lumen 1L of the delivery catheter 1 and the stylet wire 3 inserted into the second lumen 2L of the needle catheter 2 are each shown by a solid line.

[0056] The surgeon can perform the drug solution injection treatment procedure, for example, by following the steps a1 to a10 below. (a1) The surgeon inserts a work horse wire (a guide wire for delivery) from the upper arm or thigh and delivers it to the entrance of the left coronary artery 94. (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 and delivers it until the side opening OP of the delivery catheter 1 reaches a position near the injection site of the drug solution in the left coronary artery 94. At this time, the surgeon adjusts the circumferential orientation of the delivery catheter 1 so that the side opening OP of the delivery catheter 1 is positioned on the side of the myocardium 96, as shown in Figure 9. The surgeon then removes the workpiece wire from the delivery catheter 1.

[0057] (a5) The surgeon inserts the stylet wire 3 into the needle catheter 2 through the proximal end opening 2b of the needle catheter 2 and withdraws it from the distal end opening 2a, thereby inserting the stylet wire 3 into the needle catheter 2 (putting the needle catheter 2 in an inserted state). At this time, the surgeon tightens the cap cp while the first section S1 of the stylet wire 3 protrudes from the distal end opening 2a, thereby securing this state. (a6) The surgeon inserts the inserted needle catheter 2 through the proximal end opening 1b of the delivery catheter 1. The surgeon gently curves the bending portion 211 of the needle catheter 2 until the length of the bending portion 211 in the bending direction (in the case of Figure 6, the -Y-axis direction) is equal to or less than the inner diameter Φ1L of the delivery catheter 1 (see Figure 1). (a7) The surgeon pushes the inserted needle catheter 2 toward the distal end within the first lumen 1L of the delivery catheter 1. At this time, as shown in Fig. 9 , the portion of the stylet wire 3 protruding from the distal opening 2a corresponding to the first section S1 functions as a buffer member that lifts the puncture needle 21 of the needle catheter 2 and prevents the puncture needle 21 of the needle catheter 2 from contacting the inner circumferential surface 12i of the delivery catheter 1. This prevents damage to the needle catheter 2 and the delivery catheter 1 when the needle catheter 2 is delivered. As shown in Fig. 9 , a gap GP is generated between the distal opening 2a and the inner circumferential surface 12i of the delivery catheter 1 due to the rigidity of the stylet wire 3 and the gentle bending of the bending section 211 when the needle catheter 2 is inserted into the first lumen 1L in the inserted state. The details of the gap GP will be described later using Fig. 13 .

[0058] (a8) After delivering the needle catheter 2 to just before the side opening OP of the delivery catheter 1, the surgeon removes the stylet wire 3 from the needle catheter 2 as shown in Fig. 10 . Withdrawing the stylet wire 3 causes the curved shape of the puncture needle 21 of the needle catheter 2 (the shape of the curved portion 211), which had been gradually changed by the thickness of the stylet wire 3 and the formation of the gap GP, to return to its original shape by the thickness of the stylet wire 3 and the gap GP. When the surgeon further advances the puncture needle 21 of the needle catheter 2 up to the side opening OP of the delivery catheter 1, the curved shape of the puncture needle 21 (the shape of the curved portion 211) completely returns to its original shape, and as a result, the puncture needle 21 of the needle catheter 2 naturally protrudes outward through the side opening OP as shown in Fig. 11 . That is, in the puncture needle system 1000, as described in (a7) and (a8), the needle catheter 2 is pushed forward toward the distal end of the delivery catheter 1 while inserted, and then the stylet wire 3 is withdrawn from the second lumen 2L, causing the puncture needle 21 to protrude from the side opening OP to the outside of the delivery catheter 1. (a9) As shown in FIG. 12 , the surgeon pushes the needle catheter 2 with the puncture needle 21 of the needle catheter 2 protruding from the side opening OP. (a10) The surgeon attaches a syringe filled with a medicinal solution to the proximal end opening 2b of the needle catheter 2 and supplies the medicinal solution from the syringe to the second lumen 2L. The medicinal solution passes through the second lumen 2L and is protruded from the distal end 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).

[0059] Figure 13 is an enlarged view of the vicinity of the tip of the needle catheter 2 in the inserted state, inserted into the first lumen 1L of the delivery catheter 1. Figure 13 shows a longitudinal cross section of the delivery catheter 1, needle catheter 2, and stylet wire 3, taken along a cross section passing through the axis O (see Figures 2 to 6) and the tip D. As shown in Figure 13, in the puncture needle system 1000, when the needle catheter 2 in the inserted state is inserted into the first lumen 1L, a gap GP is formed between the center CT of the tip opening 2a and the inner circumferential surface 12i of the delivery catheter 1. The gap between the center CT of the tip opening 2a and the inner circumferential surface 12i of the delivery catheter 1 refers to the gap between the center CT and a portion SD of the inner circumferential surface 12i of the delivery catheter 1 that is closest to the center CT in the longitudinal cross section. In the puncture needle system 1000, the rigidity of the stylet wire 3 and the rigidity of the puncture needle 21 are adjusted so that the gap GP is formed. In detail, the rigidity of at least the first section S1 and the second section S2 (see FIGS. 1 and 7 ) of the stylet wire 3 is greater than 1 / 50 of the rigidity of the puncture needle 21, but less than the rigidity of the puncture needle 21. In this embodiment, the rigidity of the stylet wire 3 over its entire length is greater than 1 / 50 of the rigidity of the puncture needle 21, but less than the rigidity of the puncture needle 21. The rigidities of the stylet wire 3 and the puncture needle 21 are calculated by a three-point bending test.

[0060] 14 is an explanatory diagram showing a state in which a gap GP is not formed in a puncture needle system of a comparative example. The puncture needle system of the comparative example is the same as the puncture needle system 1000 of the first embodiment in that it includes a delivery catheter 1. The puncture needle system of the comparative example differs from the puncture needle system 1000 of the first embodiment in that it includes a needle catheter 2C and a stylet wire 3C that are different from the needle catheter 2 and the stylet wire 3. In the needle catheter 2C and stylet wire 3C of the comparative example, the rigidity of the stylet wire 3C and the rigidity of the puncture needle 21 are not adjusted to form the gap GP. Therefore, as shown in FIG. 14 , in a longitudinal cross section when the needle catheter 2C is inserted into the first lumen 1L, no gap GP is formed between the center CT of the distal end opening 2a and the inner circumferential surface 12i of the delivery catheter 1. In this case, when the inserted needle catheter 2C is pushed toward the distal end of the delivery catheter 1 within the first lumen 1L, the force pushing the base end of the needle catheter 2C toward the distal end is directed in the direction PD in which the distal end of the needle catheter 2C pushes the inner circumferential surface 12i of the delivery catheter 1, making it difficult to push the inserted needle catheter 2C toward the distal end within the first lumen 1L. In this regard, with the needle catheter 2 and stylet wire 3 of the first embodiment, as described in Figure 13, a gap GP is formed between the center CT of the distal opening 2a and the inner circumferential surface 12i of the delivery catheter 1 in the longitudinal cross section when the needle catheter 2 is inserted into the first lumen 1L in the inserted state, which prevents the force pushing the base end of the needle catheter 2 toward the distal end from being directed in the direction PD in which the distal end of the needle catheter 2 pushes the inner circumferential surface 12i of the delivery catheter 1.

[0061] FIG. 15 is an explanatory diagram showing the needle catheter 2 in an inserted state inserted into a transparent cylindrical member TP having a cylindrical space SP formed therein. The space SP has an inner diameter ΦT that is the same length as the inner diameter Φ1L of the first lumen 1L (see FIG. 1). As shown in FIG. 15 , when the needle catheter 2 and stylet wire 3 of the puncture needle system 1000 are inserted into the member TP as the needle catheter 2 in the inserted state, as described in FIG. 13 , a gap GP is formed between the center CT of the distal end opening 2a (see FIG. 13 ) and the inner circumferential surface TPi of the delivery catheter 1. The characteristics of the needle catheter 2 and stylet wire 3 can be confirmed by inserting them into the delivery catheter 1, as described in FIG. 13 . These characteristics can also be confirmed by inserting them into the member TP having the space SP formed therein, as described in FIG. 15 .

[0062] As described above, with the puncture needle system 1000 of the first embodiment, the needle catheter 2 can be placed in an inserted state in which the stylet wire 3 is inserted into the second lumen 2L and protrudes from the distal end opening 2a. When the inserted needle catheter 2 is pushed toward the distal end of the delivery catheter 1, the stylet wire 3 protruding from the distal end opening 2a functions as a buffer that prevents the puncture needle 21 from contacting the inner circumferential surface of the delivery catheter 1. This prevents damage to the puncture needle 21 and the delivery catheter 1 when the needle catheter 2 is delivered. By removing the stylet wire 3 from the second lumen 2L after the inserted needle catheter 2 reaches the vicinity of the side opening OP, the curve of the curved portion 211 of the puncture needle 21, which had been relaxed by the insertion of the stylet wire 3, returns to its original shape, making it easier for the puncture needle 21 to protrude from the side opening OP to the outside of the delivery catheter 1. Therefore, it is possible to provide a puncture needle system 1000 that allows for good puncture into body tissue while achieving both efficiency and safety in the procedure.

[0063] In the puncture needle system 1000 of the first embodiment, the outer diameter of the stylet wire 3 over its entire length is greater than half the inner diameter of the puncture needle 21, but is smaller than the inner diameter of the puncture needle 21. Therefore, in the inserted state, the clearance between the outer surface of the stylet wire 3 and the inner surface of the puncture needle 21 in the second section S2 is small, thereby reducing the range over which the puncture needle 21 can move around the stylet wire 3 in the second section S2. This prevents the tip of the puncture needle 21 from moving too far away from the stylet wire 3 and coming into contact with the inner surface of the delivery catheter 1. As a result, damage to the puncture needle 21 and the delivery catheter 1 during delivery of the needle catheter 2 can be further reduced.

[0064] If the clearance between the inner circumferential surface of the puncture needle 21 and the outer circumferential surface of the stylet wire 3 is large, there is a risk that the stylet wire 3 will kink when being removed from the second lumen 2L, becoming caught in the second lumen 2L and immobilizing. In this regard, in the puncture needle system 1000 of the first embodiment, the outer diameter of the stylet wire 3 over its entire length is greater than half the inner diameter of the puncture needle 21 and is smaller than the inner diameter of the puncture needle 21, thereby reducing the possibility of kinking of the stylet wire 3 at least in the second lumen 2L within the puncture needle 21. As a result, the stylet wire 3 can be more easily removed from the second lumen 2L.

[0065] 13 and 15 , when the needle catheter 2 in the inserted state is inserted into the first lumen 1L or the member TP, a gap GP is formed between the center CT of the distal end opening 2a and the inner circumferential surface 12i of the delivery catheter 1. In the puncture needle system 1000 of the first embodiment, the rigidity of the stylet wire 3 over the entire length of the stylet wire 3 is greater than 1 / 50 of the rigidity of the puncture needle 21, but is less than the rigidity of the puncture needle 21. Therefore, because the curve of the curved portion 211 of the puncture needle 21 is gentle in the inserted state, when the needle catheter 2 in the inserted state is pushed toward the distal end of the delivery catheter 1 within the first lumen 1L, the force pushing the base end of the needle catheter 2 toward the distal end can be prevented from being directed in the direction PD (see FIG. 14 ) in which the distal end of the needle catheter 2 pushes against the inner circumferential surface 12i of the delivery catheter 1. Therefore, the needle catheter 2 in the inserted state can be easily pushed forward toward the distal end within the first lumen 1L, thereby improving the efficiency of the procedure.

[0066] 16 is an explanatory diagram illustrating a longitudinal cross section of a stylet wire 3A included in a puncture needle system of a second embodiment. The puncture needle system of the second embodiment is the same as the puncture needle system 1000 of the first embodiment, except that, compared to the puncture needle system 1000 of the first embodiment, the puncture needle system of the second embodiment includes a stylet wire 3A instead of the stylet wire 3.

[0067] The stylet wire 3A includes a core wire 31A, a coil body 33, a distal joint 35, and a proximal joint 37. The core wire 31A is a cylindrical member having an elongated outer shape. The core wire 31A has an outer diameter that decreases from the proximal end toward the distal end. The core wire 31A can be formed from the same material as the core wire 31 of the first embodiment.

[0068] The coil body 33 is a substantially cylindrical coil body having a substantially constant outer diameter from the base end side to the tip end side. The coil body 33 is arranged to surround the tip end of the core wire 31A. In this embodiment, the coil body 33 is a single-filament coil body formed by winding a single element wire into a multifilament. The coil body 33 may be a multifilament coil body formed by winding multiple element wires into a multifilament, a single-filament stranded coil body formed by winding a singlefilament of a stranded wire obtained by twisting multiple element wires together, or a multifilament stranded coil body formed by using multiple strands of wires twisted together and winding each strand into a multifilament.

[0069] The distal joint 35 has a hemispherical distal end and joins the distal end of the core wire 31A to the distal end of the coil body 33. The proximal joint 37 joins the core wire 31A to the proximal end of the coil body 33. The distal joint 35 and the proximal joint 37 are formed of any bonding agent, for example, a metal solder such as silver solder, gold solder, zinc, an Sn—Ag alloy, or an Au—Sn alloy. The distal joint 35 and the proximal joint 37 may also be formed of an adhesive such as an epoxy adhesive or a cyanoacrylic adhesive.

[0070] Similar to the stylet wire 3 of the first embodiment, the stylet wire 3A has a first section SA1 including the distal end and a second section SA2 adjacent to the first section SA1 from the proximal end. Similar to the first section S1 of the first embodiment, the first section SA1 corresponds to the portion of the stylet wire 3 intended to protrude from the distal opening 2a of the needle catheter 2 in the inserted state. Similar to the second section S2 of the first embodiment, the second section SA2 corresponds to the portion of the stylet wire 3 intended to be disposed inside the puncture needle 21 in the inserted state. The coil body 33 is disposed so as to surround the core wire 31A in the first section SA1 and the second section SA2. A radiopaque marker is provided on the coil body 33 in the first section SA1. Specifically, the coil body 33 in the first section SA1 is formed of platinum or any other radiopaque metal. That is, in the first section SA1, the coil body 33 itself, formed of a radiopaque metal, functions as a marker. The coil body 33 in the second section SA2 and the coil body 33 on the proximal side of the second section SA2 are made of stainless steel such as SUS304, a nickel-titanium alloy, a cobalt-chromium alloy, or the like.

[0071] The length of the outer diameter of the core wire 31A in the second section SA2 is greater than one-third of the inner diameter of the tip of the puncture needle 21, but is smaller than the length of the inner diameter of the tip of the puncture needle 21. In this embodiment, the inner diameter of the puncture needle 21 is also constant, so the length of the outer diameter of the core wire 31A in the second section SA2 is greater than one-third of the inner diameter of the puncture needle 21, but is smaller than the length of the inner diameter of the puncture needle 21. The length of the outer diameter of the stylet wire 3A (outer diameter of the coil body 33) in the second section SA2 is greater than half the inner diameter of the puncture needle 21, but is smaller than the length of the inner diameter of the puncture needle 21.

[0072] In the puncture needle system of the second embodiment, the rigidity of the stylet wire 3A and the rigidity of the puncture needle 21 are also adjusted so as to form the gap GP (see FIG. 13 ). Specifically, the rigidity of the first section SA1 and the second section SA2 of the stylet wire 3A is greater than 1 / 50 of the rigidity of the puncture needle 21, but is smaller than the rigidity of the puncture needle 21.

[0073] Like the first embodiment, the puncture needle system of the second embodiment described above is a puncture needle system that enables good puncture of body tissue while achieving both procedural efficiency and safety. According to the puncture needle system of the second embodiment, even if at least the portion of the stylet wire 3A corresponding to the first section SA1 protrudes out of the delivery catheter 1 through the side opening OP when the inserted needle catheter 2 is pushed toward the distal end of the delivery catheter 1 within the first lumen 1L, damage to body tissue is suppressed because this portion is composed of a flexible core wire 31A, a coil body 33, and a hemispherical distal end joint 35. In the puncture needle system of the second embodiment, the portion of the stylet wire 3A corresponding to the second section SA2 is provided with the coil body 33. Therefore, the unevenness of the outer peripheral surface of the coil body 33 suppresses longitudinal misalignment between the needle catheter 2 and the stylet wire 3A in the inserted state. Therefore, the needle catheter 2 in the inserted state, which is less likely to slip longitudinally relative to the stylet wire 3A, can be easily pushed forward toward the distal end within the first lumen 1L, thereby achieving both greater efficiency and safety in the procedure.

[0074] In the puncture needle system of the second embodiment, the outer diameter of the core wire 31A in the second section SA2 is greater than one-third the inner diameter of the puncture needle 21 and less than the inner diameter of the puncture needle 21. Therefore, in the inserted state, the clearance between the outer surface of the stylet wire 3A in the second section SA2 (the outer surface in the section where the core wire 31A is surrounded by the coil body 33) and the inner surface of the puncture needle 21 is reduced, thereby narrowing the range over which the puncture needle 21 can move around the stylet wire 3A in the second section SA2. This prevents the tip of the puncture needle 21 from moving too far away from the stylet wire 3A and coming into contact with the inner surface of the delivery catheter 1. As a result, damage to the puncture needle 21 and the delivery catheter 1 during delivery of the needle catheter 2 can be further reduced. As in the first embodiment, the possibility of kinking of the stylet wire 3A can be reduced, at least in the second lumen 2L within the puncture needle 21. As a result, the stylet wire 3A can be easily removed from the second lumen 2L. In order to prevent the puncture needle 21 from slipping off the core wire 31A on the coil body 33 in the inserted state, it is preferable to design the clearance between the core wire 31A and the coil body 33 (the difference between the outer diameter of the core wire 31A and the inner diameter of the coil body 33) to be small.

[0075] In the puncture needle system of the second embodiment, a radiopaque marker is provided on the coil body 33 in the first section SA1. Therefore, by checking the position of the marker under an angio image, the position of the first section SA1 of the stylet wire 3A in the inserted needle catheter 2 can be easily determined, thereby improving the efficiency of the procedure.

[0076] <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.

[0077] [Variation 1] In the first and second embodiments, the inner diameter of the puncture needle 21 was constant. However, this is not limited thereto, and the diameter may decrease from the proximal end to the distal end. Even in such a case, it is preferable that the outer diameter of the stylet wire 3 (outer diameter of the core wire 31) and the outer diameter of the stylet wire 3A (outer diameter of the coil body 33) in the second section S2 be greater than half the length of the distal inner diameter of the puncture needle 21 and be smaller than the length of the distal inner diameter of the puncture needle 21. In the first embodiment, the outer diameter of the stylet wire 3 (outer diameter of the core wire 31) was constant. However, this is not limited thereto, and the diameter may decrease from the proximal end to the distal end. Even in such a case, it is preferable that the outer diameter of the stylet wire 3 (outer diameter of the core wire 31) in the second section S2 be greater than half the length of the distal inner diameter of the puncture needle 21 and be smaller than the length of the distal inner diameter of the puncture needle 21. In the second embodiment, the outer diameter of the core wire 31A decreased from the proximal end to the distal end. Even in such a case, it is preferable that the outer diameter of the core wire 31A in the second section SA2 is greater than one-third of the inner diameter of the tip of the puncture needle 21 and is smaller than the inner diameter of the tip of the puncture needle 21.

[0078] [Variation 2] In the first embodiment, the rigidity of the stylet wire 3 and the rigidity of the puncture needle 21 were adjusted so as to form the gap GP. This is not limiting. For example, instead of or in addition to adjusting the rigidity of the stylet wire 3 and the rigidity of the puncture needle 21, the degree of curvature of the bending portion 211 when the stylet wire 3 is not inserted, the inner diameter Φ1L of the first lumen 1L, the inner diameter Φ2L of the second lumen 2L, and the outer diameter Φ3 of the stylet wire 3 may each be adjusted so as to form the gap GP.

[0079] [Variation 3] In the first embodiment described above, the rigidity of the stylet wire 3 over the entire length thereof is greater than 1 / 50 of the rigidity of the puncture needle 21, but less than the rigidity of the puncture needle 21. This is not limiting. The range of the stylet wire 3 that is greater than 1 / 50 of the rigidity of the puncture needle 21, but less than the rigidity of the puncture needle 21, may be any range, as long as it includes at least the first section S1 and the second section S2.

[0080] [Variation 4] In the first embodiment, it was confirmed that the gap GP was formed by inserting the needle catheter 2 in the inserted state into the delivery catheter 1 or the transparent cylindrical member TP. However, this is not limited to this. For example, it may be confirmed that the gap GP is formed by inserting the needle catheter 2 in the inserted state into the transparent rectangular parallelepiped member TPa shown in Figure 17. The member TPa is a transparent member having a cylindrical space SP formed therein, similar to the member TP.

[0081] [Modification 5] In the second embodiment, the coil body 33 is disposed so as to surround the core wire 31A in the first section SA1 and the second section SA2. However, this is not limiting. For example, the coil body 33 may be disposed so as to surround the core wire 31A over the entire length of the core wire 31A.

[0082] [Variation 6] In the second embodiment, the portion of the coil body 33 corresponding to the first section SA1 is formed of a radiopaque metal, thereby providing a radiopaque marker. However, this is not limited to this. For example, the radiopaque marker may be provided by attaching an annular member separate from the coil body 33 to the portion of the coil body 33 corresponding to the first section SA1.

[0083] [Variation 7] In the first and second embodiments, the puncture needle system includes the delivery catheter 1, the needle catheter 2, and the stylet wire 3 or the stylet wire 3A. However, the present invention is not limited to this. For example, the puncture needle unit may include the needle catheter 2 and the stylet wire 3 or the stylet wire 3A, but does not include the delivery catheter 1.

[0084] In the first embodiment described above, the second hollow shaft 22 includes a distal shaft 22D and a proximal shaft 22P as described with reference to FIGS. 2 to 5 , but this is not limiting. For example, the second hollow shaft 22 may include a distal shaft 22D and a proximal shaft 22Pa that is different from the proximal shaft 22P. FIG. 18 shows a cross section of the proximal shaft 22Pa. Compared to the proximal shaft 22P shown in FIG. 5 , the proximal shaft 22Pa further includes a coil body 221 between the tube 222 and the shaft 231. In other words, the structure of the proximal shaft 22Pa corresponds to the structure in which the outer circumferential surface of the distal shaft 22D shown in FIG. 4 is surrounded by the shaft 231.

[0085] 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 puncture needle system (1000) comprising: a delivery catheter (1) having a first hollow shaft (12) with a first lumen (1L) therein, the first hollow shaft (12) having a side opening (OP) on the side thereof that connects the first lumen (1L) to the outside; a needle catheter (2) having a hollow puncture needle (21) with a curved portion (211) at its tip and a tip opening (2a) at its tip; and a second hollow shaft (22) that is continuous with the puncture needle (21) and is positioned proximal to the puncture needle (21), and has a second lumen (2L) therein that connects with the interior of the puncture needle (21) and connects with the outside via the tip opening (2a); and a stylet wire (3, 3A), a puncture needle system in which the needle catheter (2) is pushed forward within the first lumen (1L) toward the tip side of the delivery catheter (1) in an inserted state in which the stylet wire (3, 3A) is inserted into the second lumen (2L) and protrudes from the tip opening (2a), and then the stylet wire (3, 3A) is removed from the second lumen (2L), causing the puncture needle (21) to protrude to the outside from the side opening (OP).

2. A puncture needle system (1000) as set forth in claim 1, wherein the stylet wire (3, 3A) has a first section (S1, SA1) including a tip, and a second section (S2, SA2) that is continuous with the first section (S1, SA1) and is positioned more proximal than the first section (S1, SA1), and the length of the outer diameter of the stylet wire (3, 3A) in the second section (S2, SA2) is greater than half the length of the inner diameter of the tip of the puncture needle (21) and is less than the length of the inner diameter of the tip.

3. A puncture needle system (1000) according to claim 1 or 2, wherein, in a side view in which the curved shape of the curved portion (211) can be seen, the distance (S) between the tip of the needle catheter (2) and one of the lines defining the outer periphery of the second hollow shaft (22) that is farther from the tip of the needle catheter (2) is greater than the inner diameter (Φ1L) of the delivery catheter (1), and when the needle catheter (2) in the inserted state is inserted into the first lumen (1L), a gap (GP) is formed between the center (CT) of the tip opening (2a) and the inner peripheral surface (SD) of the delivery catheter (1).

4. The puncture needle system (1000) according to any one of claims 1 to 3, wherein, in a side view in which the curved shape of the curved portion (211) can be seen, the distance (S) between the tip of the needle catheter (2) and one of the lines defining the outer periphery of the second hollow shaft (22) that is farther from the tip of the needle catheter (2) is greater than the inner diameter (Φ1L) of the delivery catheter (1), and when the needle catheter (2) in the inserted state is inserted into a transparent member (TP, TPa) having a cylindrical space (SP) formed therein and having an inner diameter (ΦT) the same length as the inner diameter (Φ1L) of the first lumen (1L), a gap (GP) is formed between the center (CT) of the tip opening (2a) and the inner peripheral surface (SD) of the delivery catheter (1).

5. A puncture needle system (1000) according to any one of claims 1 to 4, wherein the stylet wire (3, 3A) has a first section (S1, SA1) including a tip, and a second section (S2, SA2) that is continuous with the first section (S1, SA1) and is positioned closer to the base end than the first section (S1, SA1), and the rigidity of at least the first section (S1, SA1) and the second section (S2, SA2) of the stylet wire (3, 3A) is higher than 1 / 50 of the rigidity of the puncture needle (21) and lower than the rigidity of the puncture needle (21).

6. A puncture needle system (1000) according to any one of claims 1 to 5, wherein the stylet wire (3A) has a first section (SA1) including a tip, and a second section (SA2) that is continuous with the first section (SA1) and is positioned more proximal than the first section (SA1), and further comprises: a core wire (31A); a coil body (33) that surrounds the core wire (31A) in the first section (SA1) and the second section (SA2); and a tip joint (35) that has a hemispherical tip and joins the tip of the core wire (31A) and the tip of the coil body (33).

7. A puncture needle system (1000) as described in claim 6, wherein the length of the outer diameter of the core wire (31A) in the second section (SA2) is greater than one-third of the length of the inner diameter of the tip of the puncture needle (21) and is smaller than the length of the inner diameter of the tip.

8. A puncture needle system (1000) according to claim 6 or claim 7, wherein the coil body (33) in the first section (SA1) is provided with a radiopaque marker.

9. A puncture needle unit comprising: a needle catheter (2) equipped with a hollow puncture needle (21) having a curved portion (211) at the tip and a tip opening (2a) at the tip; and a hollow shaft (22) continuous with the puncture needle (21) and positioned proximal to the puncture needle (21), the hollow shaft having an internal lumen (2L) that communicates with the interior of the puncture needle (21) and with the outside via the tip opening (2a); and a stylet wire (3, 3A), wherein the stylet wire (3, 3A) is capable of being inserted into the lumen (2L) while protruding from the tip opening (2a) and being removable from the lumen (2L).

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