Guide wire

Abstract

To provide a guide wire securing safety by suppressing erroneous puncture by a puncture part.SOLUTION: A guide wire for guiding a dilator to be inserted into a living body comprises a long shaft part 11 with flexibility, a puncture part 15 disposed at a tip of the shaft part and forming a hole in a biological tissue, and an elastically deformable cover part 30 for covering the puncture part 15. The cover part 30 include a wire 31 to be wound spirally, a sparse pitch part 36 contractile along a central shaft X, and a tip cover 30B located on a tip side of the sparse pitch part 36, capable of covering at least a part of the puncture part 15, having no clearance, and undeformable. The puncture part 15 includes a first contact part 16, and the tip cover 30B includes a second contact part 39 capable of coming into contact with the first contact part 16 from a base end side. The tip cover 30B extends from the second contact part 39 to the tip side, and when the first contact part 16 comes into contact with the second contact part 39, a relative axial movement of the first contact part 16 and the second contact part 39 is restricted.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a guide wire for puncturing a living tissue.

Background Art

[0002] The heart repeats contraction and relaxation at appropriate timing and circulates blood by an electric current flowing through myocardial tissue called the conduction system. When the generation and transmission of the electrical signal flowing through this conduction system become abnormal, contraction and relaxation cannot be performed at appropriate timing, and arrhythmia occurs.

[0003] As a treatment method for arrhythmia, a method of ablating and blocking the conduction path of the signal causing arrhythmia by heating or cooling is known. As a device for performing this treatment method, a device that can be inserted percutaneously up to the left atrium and ablate the conduction path of the signal located at the pulmonary vein ostium is known. Such an ablation device is widely used because it is minimally invasive and highly effective.

[0004] When performing ablation in the left atrium, a technique called transseptal puncture (Brockenbrough method) is required, in which a needle is inserted into a thin septum called the fossa ovalis of the atrial septum from the right atrium to create a hole communicating from the right atrium to the left atrium. Transseptal needles, which are devices for performing this transseptal puncture, include mechanical needles and radio frequency needles. Mechanical needles are the mainstream because they are inexpensive.

[0005] A mechanical puncture needle performs puncture using a sharp needle. When using a mechanical puncture needle, there is a risk of accidental puncture due to excessive pressing of the needle. An accidental puncture by the needle may be accompanied by a serious complication called cardiac tamponade (a state in which blood accumulates between the pericardium and the myocardium, leading to heart failure). On the other hand, a high-frequency energy puncture needle is a method of penetrating the atrial septum by outputting high-frequency energy supplied from a console, which is a separately provided device. Therefore, the high-frequency energy puncture needle has no risk of accidental puncture, but it is expensive and requires a console.

[0006] For example, Patent Document 1 describes a device in which an inner needle, which is a mechanical puncture needle, is disposed inside a tubular outer needle. The tip of the inner needle is bent so as to face the proximal end side. The tip of the inner needle is accommodated in the outer needle in a linearly extended state. The inner needle protrudes from the outer needle to make a hole in the atrial septum from the right atrium side, and after reaching the left atrium, it bends toward the proximal end side. Thus, the device described in Patent Document 1 suppresses the occurrence of accidental puncture by the inner needle.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] The inner needle of the device described in Patent Document 1 bends toward the proximal end side after puncture, but is not accommodated in another member. Therefore, this device still has a risk of accidental puncture by the inner needle. Also, the inner needle is always exposed inside the outer needle. For this reason, when inserting the inner needle into the outer needle and transporting it to the atrial septum, the inside may damage the outer needle, or the tip of the inner needle may be damaged. Also, a high level of safety is required for a device that punctures biological tissue.

[0009] The present invention has been made to solve the above-described problems, and an object thereof is to provide a guide wire that can suppress accidental puncture by a puncture portion that performs puncture and can obtain high safety.

Means for Solving the Problems

[0010] The guide wire according to the present invention that achieves the above object is a guide wire for guiding a tubular elongated body inserted into a living body, and includes an elongated shaft portion having flexibility, a puncture portion disposed at a distal end portion of the shaft portion for forming a hole in a living tissue, and a cover portion that is elastically deformable and covers the puncture portion. The cover portion has a sparse pitch that can be contracted along a central axis of winding having a wire wound in a spiral shape, and a non-deformable distal end cover that is located on the distal end side of the sparse pitch and can cover at least a part of the puncture portion without a gap. The shaft portion or the puncture portion has a first contact portion, and the distal end cover has A housing tube that slidably houses the puncturing portion, a wire fixing portion that is continuously fixed to the inside of the housing tube from the wire forming the sparse pitch portion toward the tip side, a second contact portion located on the proximal end side with respect to the first contact portion and is located on the surface on the tip side of the wire fixing portion The second contact portion and, and extends to the distal end side from the second contact portion. When the first contact portion contacts the second contact portion, relative axial movement between the first contact portion and the second contact portion is restricted.

Advantages of the Invention

[0011] In the guide wire configured as described above, since the cover portion covers the puncture portion, accidental puncture by the puncture portion is suppressed, and high safety can be obtained. In addition, when the first contact portion contacts the second contact portion, relative axial movement between the first contact portion and the second contact portion is restricted, and elongation of the cover portion is restricted.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Mode for Carrying Out the Invention

[0013] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the dimensions in the drawings may be exaggerated for convenience of explanation and may be different from the actual dimensions. Also, in this specification and the drawings, components having substantially the same function are denoted by the same reference numerals, and redundant explanations are omitted. In this specification, the side to be inserted into the lumen will be referred to as the "tip side", and the hand-operated side will be referred to as the "proximal end side".

[0014] The guide wire 10 according to an embodiment of the present invention has a puncturing function and is used to form a hole in the fossa ovalis O that communicates from the right atrium to the left atrium. The hole may be a slit. When there is a hole in the fossa ovalis O, after guiding an ablation catheter inserted percutaneously into the large vein to the right atrium, it can be inserted into the left atrium through the hole and ablate around the pulmonary vein ostium. That is, the guide wire 10 is used to form an access route for the ablation catheter in the fossa ovalis O.

[0015] As shown in FIG. 1, the guide wire 10 is used together with a sheath assembly 20 into which the guide wire 10 can be inserted. The sheath assembly 20 has a reinforcing tube 60 into which the guide wire 10 is inserted, a dilator 40 into which the reinforcing tube 60 is inserted, and an outer sheath 50 into which the dilator 40 is inserted.

[0016] The guide wire 10 is a long device that guides a sheath assembly 20 including a dilator 40 and an ablation catheter to a target position within a blood vessel. Further, the guide wire 10 also has a function of puncturing the fossa ovalis O. As shown in FIGS. 1 and 2, the guide wire 10 includes a shaft portion 11 that is a long wire, a puncturing portion 15 having a sharp needle portion 15A, and a cover portion 30 that houses the puncturing portion 15.

[0017] The guide wire 10 has a wire curve portion 10A whose axis bends at a site where the cover portion 30 covers the shaft portion 11. The wire curve portion 10A bends by fixing the non-bent cover portion 30 to the bent shaft portion 11. Alternatively, the wire curve portion 10A may bend by fixing the bent cover portion 30 to the non-bent shaft portion 11. Alternatively, the wire curve portion 10A may bend by fixing the bent cover portion 30 to the bent shaft portion 11.

[0018] The wire curve portion 10A is bent in a natural state where external forces such as gravity and blood flow do not act. Note that the wire curve portion 10A does not have to be bent in the natural state as long as it is bent in the usage environment. For example, the wire curve portion 10A may be bent by the action of its own weight, or may be bent by receiving force from the blood flow. Since the guide wire 10 is flexible, the wire curve portion 10A can be formed by the action of external forces such as its own weight and blood flow even if it is not bent in the natural state.

[0019] The shaft portion 11 includes a shaft base end portion 12 located on the base end side, a shaft tip end portion 14 located on the tip end side, and a shaft diameter-reduced portion 13 located between the shaft base end portion 12 and the shaft tip end portion 14. The shaft base end portion 12 is a portion with a constant outer diameter located on the base end side. The shaft diameter-reduced portion 13 extends from the shaft base end portion 12 toward the tip end side and is a portion where the outer diameter decreases in a tapered shape. Due to the outer diameter of the shaft diameter-reduced portion 13 decreasing in a tapered shape, physical properties such as bending rigidity gradually change along the axial direction. Therefore, the shaft diameter-reduced portion 13 can suppress the occurrence of kinks or the like due to a sudden change in physical properties. Also, the bending rigidity of the shaft diameter-reduced portion 13 gradually decreases along the axial direction. For this reason, the shaft portion 11 has high pushability and reachability in a tortuous blood vessel. The shaft tip end portion 14 is a portion with a constant outer diameter extending from the shaft diameter-reduced portion 13 toward the tip end side. The outer diameter of the shaft tip end portion 14 is smaller than the outer diameter of the shaft base end portion 12. Note that the outer diameter of the shaft tip end portion 14 does not necessarily have to be constant.

[0020] The constituent material of the shaft portion 11 preferably has flexibility and is somewhat rigid. For example, metals such as stainless steel, tantalum, titanium, platinum, gold, tungsten, shape memory alloys imparted with shape memory effect or superelasticity by heat treatment, polyolefins such as polyethylene and polypropylene, polyesters such as polyamide and polyethylene terephthalate, fluorine-based polymers such as PTFE (polytetrafluoroethylene) and ETFE (ethylene-tetrafluoroethylene copolymer), PEEK (polyetheretherketone), polyimide, etc. can be suitably used. Shape memory alloys such as Ni-Ti-based, Cu-Al-Ni-based, Cu-Zn-Al-based, etc. can be suitably used. Also, the shaft portion 11 may contain an X-ray contrast material. The X-ray contrast material is preferably formed from at least one metal or two or more alloys selected from the group consisting of gold, platinum, iridium, tungsten, or their alloys, and silver-palladium alloy.

[0021] The axial length of the shaft portion 11 is, for example, 300 to 5000 mm, preferably 1000 to 3000 mm, more preferably 1500 to 2500 mm. The outer diameter of the shaft tip portion 14 is, for example, 0.04 to 0.8 mm, preferably 0.08 to 0.4 mm, more preferably 0.12 to 0.35 mm. The outer diameter of the shaft base end portion 12 is, for example, 0.3 to 1.0 mm, preferably 0.4 to 0.8 mm, more preferably 0.7 to 0.8 mm.

[0022] The puncturing portion 15 is a circular tube having a sharp needle portion 15A that pierces biological tissue. The puncturing portion 15 is provided with a through hole 17 that penetrates from the base end side to the tip end side. The puncturing portion 15 is fixed to the tip end portion of the shaft portion 11. The puncturing portion 15 is provided with an inclined surface 18 that inclines with respect to the central axis at the tip end. A sharp needle portion 15A for puncturing biological tissue is formed at the tip end of the inclined surface 18. The tip end of the shaft tip portion 14 is disposed inside the puncturing portion 15. The tip end of the shaft tip portion 14 is fixed to the inner peripheral surface of the puncturing portion 15 by a needle fixing portion 19 by welding, adhesion, or the like. The inner diameter of the puncturing portion 15 is larger than the outer diameter of the shaft tip portion 14. The central axis of the puncturing portion 15 and the central axis of the shaft tip portion 14 preferably substantially coincide. The central axis of the puncturing portion 15 and the central axis of the shaft tip portion 14 do not have to coincide. The shape of the needle portion 15A is not particularly limited as long as it can puncture biological tissue, and may be, for example, a conical shape, a knife-shaped flat plate, or a shovel-shaped curved plate. Therefore, the through hole 17 does not have to be formed in the puncturing portion 15. Further, the cross-sectional shape of the puncturing portion 15 does not have to be circular. Further, the puncturing portion 15 may have a structure integrated with the shaft portion 11. The puncturing portion 15 may be an electrode or the like that can release energy such as current or heat. A first contact portion 16 that can contact a second contact portion 39 described later is formed on the surface on the base end side of the puncturing portion 15.

[0023] The axial length of the puncturing portion 15 is preferably such that it does not inhibit the flexibility of the guide wire 10 within the blood vessel. The axial length of the puncturing portion 15 is, for example, 2 to 10 mm, preferably 2 to 6 mm, more preferably 2 to 4 mm. The outer diameter of the puncturing portion 15 is, for example, 0.3 to 1.0 mm, preferably 0.4 to 0.8 mm, more preferably 0.7 to 0.8 mm. The inner diameter of the puncturing portion 15 is, for example, 0.1 to 0.9 mm, preferably 0.2 to 0.7 mm, more preferably 0.3 to 0.5 mm. The inclination angle of the inclined surface 18 of the puncturing portion 15 with respect to the central axis is appropriately set, and is, for example, 3 to 45 degrees, preferably 5 to 40 degrees, more preferably 10 to 35 degrees.

[0024] The constituent material of the puncturing portion 15 is preferably somewhat rigid. For example, metals such as stainless steel, tantalum, titanium, platinum, gold, tungsten, polyolefins such as polyethylene and polypropylene, polyesters such as polyamide and polyethylene terephthalate, fluorine-based polymers such as PTFE (polytetrafluoroethylene) and ETFE (ethylene-tetrafluoroethylene copolymer), PEEK (polyetheretherketone), polyimide, etc. can be preferably used.

[0025] The cover portion 30 accommodates the puncturing portion 15 so as to be able to expose it, and is tubular as a whole. The cover portion 30 has an elastically deformable part. Deformation includes both the meaning of being contractible along the central axis X of the cover portion 30 and the meaning of being movable between a state where the central axis X of the cover portion 30 is bent and a straight state. The cover portion 30 includes a coil portion 32 formed by a wire 31 that draws a helix, a housing tube 33 fixed to the tip side of the coil portion 32, and a stopper 34 fixed inside the base end portion of the housing tube 33. The coil portion 32 has an elastically deformable part.

[0026] The housing tube 33 is a circular tube that slidably houses the puncture part 15. The tip surface of the housing tube 33 is formed into a smooth curved surface through surface machining. Note that the housing tube 33 may be formed by joining a wire 31 that describes a spiral. The wire 31 forming the housing tube 33 preferably describes a spiral without gaps, but may have gaps.

[0027] The stopper 34 is a member that restricts excessive elongation of the cover part 30 by coming into contact with the puncture part 15. For example, the stopper 34 is a circular tube that is fitted and fixed inside the base end portion of the housing tube 33. The stopper 34 is located on the proximal end side of the puncture part 15 inside the housing tube 33. The shaft portion 11 passes through the inside of the stopper 34. The inner diameter of the stopper 34 is smaller than the outer diameter of the puncture part 15. For this reason, the puncture part 15 cannot pass through the inner cavity of the stopper 34. A second contact portion 39 that can contact the first contact portion 16 of the puncture part 15 is formed on the surface on the tip end side of the stopper 34. The second contact portion 39 that can contact the first contact portion 16 is formed at a stepped portion 34A where the inner diameter changes from the inner peripheral surface of the housing tube 33. The second contact portion may be formed at a site where the inner diameter changes in a tapered shape from the inner peripheral surface of the housing tube 33. Further, the second contact portion may be formed on the tip end surface of the coil portion 32.

[0028] The constituent material of the housing tube 33 is preferably somewhat hard. For example, metals such as stainless steel, tantalum, titanium, platinum, gold, tungsten, polyolefins such as polyethylene and polypropylene, polyesters such as polyamide and polyethylene terephthalate, fluorine-based polymers such as PTFE (polytetrafluoroethylene) and ETFE (ethylene-tetrafluoroethylene copolymer), PEEK (polyetheretherketone), polyimide, etc. can be suitably used.

[0029] The coil portion 32 is formed by a single continuous wire 31. Note that the coil portion 32 may be formed by a plurality of wires. The coil portion 32 has a substantially constant outer diameter and inner diameter along the central axis X of the helix. The coil portion 32 has a tip dense pitch portion 35 located on the tip side, a sparse pitch portion 36 located on the base end side of the tip dense pitch portion 35, and a base end dense pitch portion 37 located on the base end side of the sparse pitch portion 36. The tip dense pitch portion 35 and the base end dense pitch portion 37 have a shorter pitch distance of the helix than the sparse pitch portion 36. The pitch distance is the axial movement distance when the helix is wound 360 degrees in the circumferential direction. Therefore, the tip dense pitch portion 35 and the base end dense pitch portion 37 hardly contract along the central axis X of the helix. In the tip dense pitch portion 35 and the base end dense pitch portion 37, adjacent wires 31 may be in contact with each other without a gap, or may be separated with a gap. In the sparse pitch portion 36, a gap is formed between adjacent wires 31. For this reason, the sparse pitch portion 36 can contract along the central axis X of the helix. Note that the configuration of the coil portion 32 is not particularly limited as long as it includes a portion that can contract along the central axis X of the helix.

[0030] The base end of the coil portion 32 is fixed to the shaft portion 11 by a joint portion 38 made of solder, an adhesive, a material melted by welding, or the like. The joint portion 38 fills the step and gap between the base end of the coil portion 32 and the shaft portion 11. The central axis X of the helix of the coil portion 32 substantially coincides with the axis of the shaft base end portion 12, the shaft reduced diameter portion 13, and the shaft tip portion 14.

[0031] The coil portion 32 is disposed at a position overlapping the wire curve portion 10A of the guide wire 10, thereby forming a curve portion 30A that can move between a state where the central axis X is bent and a straight state. The curve portion 30A is bent in one direction in the bent state. The central axis X of the helix in the curve portion 30A may or may not coincide with the axis of the shaft portion 11. The shaft portion 11 may or may not contact the inner peripheral surface of the curve portion 30A.

[0032] The bending angle of the curved portion 30A is not particularly limited, but is preferably 45 to 85 degrees, more preferably 70 to 85 degrees. By providing the curved portion 30A, when the guide wire 10 is pushed forward in the living body, the tip of the guide wire 10 is less likely to hit the living tissue, and damage to the living tissue can be suppressed.

[0033] The cross-sectional shape of the wire 31 forming the cover portion 30, which is orthogonal to the extending direction of the wire 31, is circular. Thereby, the spring constant of the coil portion 32 can be reduced. For this reason, the coil portion 32 can be easily deformed during puncture, and the puncture resistance can be reduced. Note that the cross-sectional shape of the wire 31 forming the cover portion 30 does not have to be circular, and may be, for example, an ellipse, a rectangle, a square, a parallelogram, a trapezoid, or the like. If the cross-sectional shape of the wire 31 is a rectangle or a square, when the cover portion 30 contracts along the central axis X, the wires 31 arranged along the central axis X come into contact with a large area. Therefore, the cover portion 30 contracted along the central axis X has an improved force transmission force in the direction along the central axis X.

[0034] The cover portion 30 includes a tip cover 30B that is not deformable along the central axis X on the tip side of the portion that is deformable along the central axis X of the coil portion 32. In the present embodiment, the tip cover 30B has a housing tube 33 and a stopper 34. Alternatively, in the present embodiment, the tip cover 30B is composed of the housing tube 33, the stopper 34, and a part of the wire 31 fixed to the housing tube 33 or the stopper 34. The first contact portion 16 described above is located at the tip cover 30B that is not deformable and is located on the tip side of the deformable portion.

[0035] The length of the guide wire 10 is appropriately set, and is, for example, 300 to 5000 mm.

[0036] The coil portion 32 is formed by spirally winding a straight wire 31. Alternatively, the coil portion 32 may be cut out from a circular tube by laser processing or the like.

[0037] The constituent material of the coil portion 32 is preferably elastically deformable and somewhat rigid. For example, shape memory alloys to which a shape memory effect or superelasticity is imparted by heat treatment, metals such as stainless steel, tantalum, titanium, platinum, gold, tungsten, polyolefins such as polyethylene and polypropylene, polyesters such as polyamide and polyethylene terephthalate, fluorine-based polymers such as PTFE (polytetrafluoroethylene) and ETFE (ethylene-tetrafluoroethylene copolymer), PEEK (polyetheretherketone), polyimide, etc. can be suitably used. As the shape memory alloy, Ni-Ti-based, Cu-Al-Ni-based, Cu-Zn-Al-based, etc. can be suitably used. Further, the coil portion 32 may contain an X-ray contrast material. The X-ray contrast material is preferably formed of at least one metal or two or more alloys selected from the group consisting of gold, platinum, iridium, tungsten, or their alloys, and silver-palladium alloy. Further, by forming the coil portion 32 in a spiral shape, unevenness increases and high ultrasonic contrast can be achieved.

[0038] Generally, the guide wire 10 has a certain degree of rigidity while also having high flexibility so as not to damage the biological lumen to be inserted and to be pushed forward within a tortuous biological lumen. Therefore, in the guide wire 10 of the present embodiment, when a force directed toward the proximal end side is received at the distal end portion of the cover portion 30 in a state where bending (radial deformation) is not restricted, a part of the guide wire 10 bends and the force escapes from the distal end portion of the cover portion 30 to other parts. Further, since the distal end portion of the guide wire 10 is bent, it is difficult for a force directed toward the proximal end side to act, and it is difficult for a force to contract the cover portion 30 toward the central axis X to act. For this reason, even when the cover portion 30 receives a force directed toward the proximal end side at the tip, the force necessary to contract the cover portion 30 toward the central axis X does not act on the cover portion 30. Therefore, the cover portion 30 bends by receiving a force directed toward the proximal end side in a state where bending is free and maintains the state of accommodating the needle portion 15A.

[0039] The reinforcing tube 60 used together with the guide wire 10 can accommodate the guide wire 10 and is inserted into the dilator 40. To appropriately puncture the fossa ovalis O, it is necessary for the device to have an appropriate angle and rigidity so as to appropriately face the fossa ovalis O within the right atrium. The reinforcing tube 60 can be inserted into the dilator 40 to increase the rigidity and angle of the device.

[0040] The dilator 40 is used to widen the hole of the fossa ovalis O formed by the guide wire 10. The dilator 40 has a tapered portion 42 that tapers in diameter toward the distal end on the distal end side. The lumen of the dilator 40 opens at the most diameter-reduced end of the tapered portion 42. The dilator 40 is inserted from the proximal opening into which the reinforcing tube 60 is inserted.

[0041] The outer sheath 50 is inserted with the dilator 40 from the proximal opening. The outer sheath 50 can pass through the hole of the fossa ovalis O formed by the guide wire 10 together with the dilator 40. After the dilator 40 is removed, the outer sheath 50 provides an access route for the ablation catheter through its lumen.

[0042] Next, the operation and effects of the guide wire 10 according to this embodiment will be described.

[0043] As shown in FIG. 5(A), the guide wire 10 is accommodated in an assembly composed of the outer sheath 50 and the dilator 40 while being accommodated in the reinforcing tube 60. At this time, the tip of the guide wire 10 is disposed between the opening on the tip side of the dilator 40 and the opening on the tip side of the reinforcing tube 60. When the guide wire 10 moves within the reinforcing tube 60 and the dilator 40, the puncturing portion 15 of the guide wire 10 is maintained in a state of being accommodated in the cover portion 30. Thereby, when the guide wire 10 moves within the reinforcing tube 60 and the dilator 40, it is suppressed that the puncturing portion 15 damages the reinforcing tube 60 and the dilator 40 or the puncturing portion 15 itself is damaged.

[0044] The guide wire 10 is pushed in with the tip of the dilator 40 abutted against the fossa ovalis O. As shown in FIG. 3, the curved portion 30A of the cover portion 30 is linearly deformed inside the reinforcing tube 60.

[0045] When the guide wire 10 moves inside the reinforcing tube 60 and the dilator 40 toward the tip side, the cover portion 30 positioned on the tip side of the guide wire 10 contacts the fossa ovalis O. As a result, a force directed toward the base end side acts on the tip of the cover portion 30 positioned at the foremost end of the guide wire 10. The linearly deformed curved portion 30A receives the force directed toward the base end side, and thus changes from the state shown in FIG. 3 to the state shown in FIG. 4(A). Thereby, the curved portion 30A of the cover portion 30 elastically contracts along the central axis X.

[0046] When the coil portion 32 contracts along the central axis X, as shown in FIGS. 4(A) and 5(A), the receiving tube 33 located on the tip side of the curved portion 30A moves toward the proximal end side with respect to the puncturing portion 15. As a result, the needle portion 15A of the puncturing portion 15 accommodated inside the receiving tube 33 is exposed from the receiving tube 33 toward the tip side. Therefore, the guide wire 10 can form a hole in the fossa ovalis O by the puncturing portion 15 exposed from the cover portion 30. After the puncturing portion 15 penetrates the fossa ovalis O and reaches the left atrium, the cover portion 30 penetrates the formed hole. When the tip of the cover portion 30 penetrates the hole, as shown in FIGS. 3 and 5(B), the elastically contracted coil portion 32 extends along the central axis X by its own restoring force. As a result, the puncturing portion 15 is accommodated in the receiving tube 33 of the cover portion 30. The wire curved portion 10A and the curved portion 30A restore to their original curved shapes after protruding from the dilator 40 or the biological tissue. Since the cover portion 30 accommodating the puncturing portion 15 protrudes from the dilator 40, it is not restricted from bending. For this reason, even when a force toward the proximal end side acts on the tip of the cover portion 30 located at the leading end of the guide wire 10, the cover portion 30 can freely bend without contracting along the central axis X. For this reason, the puncturing portion 15 in the left atrium does not protrude from the cover portion 30, and the state of being accommodated in the cover portion 30 is maintained. Therefore, it is possible to prevent the puncturing portion 15 from accidentally puncturing an unintended position. Further, since the wire curved portion 10A is curved, it is difficult for the tip of the guide wire 10 to hit the biological tissue. For this reason, the wire curved portion 10A can suppress damage to the biological tissue.

[0047] For example, when pulling out the guide wire 10, the biological tissue may get caught on the sparse pitch portion 36 of the cover portion 30. In such a state, in the case of a guide wire without the first contact portion 16 and the second contact portion 39, when a tensile force in the proximal direction acts on the shaft portion 11, as shown in FIG. 4(B), the shaft portion 11 moves in the proximal direction. On the other hand, the movement of the cover portion 30 in the proximal direction is restricted by the biological tissue. As a result, since the shaft portion 11 and the cover portion 30 move relative to each other in the axial direction, the cover portion 30 may be plastically deformed. However, when a tensile force in the proximal direction acts on the shaft portion 11 with the biological tissue caught on the tip portion of the cover portion 30 and the shaft portion 11 moves in the proximal direction, the first contact portion 16 and the second contact portion 39 come into contact. Thereby, since the relative axial movement between the shaft portion 11 and the cover portion 30 is restricted, plastic deformation of the cover portion 30 can be prevented. As a result, excessive elongation of the extendable coil portion 32 located on the proximal side of the tip cover 30B is restricted. Therefore, it is possible to suppress the cover portion 30 from being plastically deformed and the puncture portion 15 from being exposed to the outside. The guide wire 10 that has passed through the fossa ovalis O can guide the movement of the dilator 40 and the outer sheath 50 from the right atrium to the left atrium.

[0048] As described above, the guide wire 10 according to the present embodiment is a guide wire 10 for guiding a tubular elongated body (for example, the dilator 40) inserted into a living body, and includes an elongated shaft portion 11 having flexibility, a puncture portion 15 disposed at the tip of the shaft portion 11 for forming a hole in the biological tissue, and a cover portion 30 that is elastically deformable and covers the puncture portion 15. The cover portion 30 has a sparse pitch portion 36 that has a wire 31 wound in a spiral shape and can contract along the central axis X of the winding, and a tip cover 30B that is located on the tip side of the sparse pitch portion 36 and can cover at least a part of the puncture portion 15. The puncture portion 15 has a first contact portion 16, and the tip cover 30B has a second contact portion 39 located on the proximal side with respect to the first contact portion 16. When the first contact portion 16 comes into contact with the second contact portion 39, the relative axial movement between the first contact portion 16 and the second contact portion 39 is restricted.

[0049] The guide wire 10 configured as described above can obtain high safety by suppressing accidental puncture by the puncture portion 15 because the cover portion 30 covers the puncture portion 15. In addition, when the first contact portion 16 contacts the second contact portion 39, the relative axial movement between the first contact portion 16 and the second contact portion 39 is restricted, and the extension of the cover portion 30 is restricted. For this reason, the guide wire 10 can suppress plastic deformation in the extension direction of the cover portion 30 that covers the puncture portion 15, suppress unintentional exposure of the puncture portion 15, and obtain high safety. Also, normally, since the puncture portion 15 is covered by the cover portion 30, it is possible to prevent the puncture portion 15 from damaging other devices or the puncture portion from being damaged during operation.

[0050] Further, the tip cover 30B has a stepped portion 34A approaching the central axis X on the inner peripheral surface, the second contact portion 39 is located at the stepped portion 34A, and the first contact portion 16 is formed at the base end portion of the puncture portion 15. Thereby, the second contact portion 39 of the stepped portion 34A of the tip cover 30B can be brought into contact with the first contact portion 16 of the puncture portion 15, and excessive extension of the cover portion can be favorably restricted.

[0051] Further, the stepped portion 34A is formed entirely around the inner peripheral surface of the tip cover 30B. Thereby, the second contact portion 39 of the stepped portion 34A provided entirely around the tip cover 30B can be surely brought into contact with the first contact portion 16 of the puncture portion 15, and excessive extension of the cover portion 30 can be favorably restricted.

[0052] Also, when moving in the direction in which the positions of the first contact portion 16 and the second contact portion 39 move apart, the puncture portion 15 protrudes from the cover portion 30. For this reason, the guide wire 10 can puncture biological tissue with the puncture portion 15 by separating the positions of the first contact portion 16 and the second contact portion 39.

[0053] Note that the present invention is not limited to the above-described embodiments, and various modifications can be made by those skilled in the art within the technical idea of the present invention. For example, the stopper 34 does not have to be formed entirely around the inner peripheral surface of the tip cover 30B. Therefore, the stopper 34 does not have to be a circular tube. For example, the stopper 34 may be a portion that protrudes radially inward from a part in the circumferential direction of the inner peripheral surface of the housing tube 33. Further, the stopper 34 and the housing tube 33 may have an integral structure.

[0054] Also, like the guide wire 70 of the first modified example shown in FIG. 6(A), a wire fixing portion 31A, which is the tip portion of the helical wire 31 forming the coil portion 32, may be fixed to the inner peripheral surface of the base end portion of the housing tube 33. The second contact portion 39 is located on the surface on the tip side of the wire fixing portion 31A. The first contact portion 16 is located on the surface on the base end side of the puncture portion 15.

[0055] As described above, the tip cover 30B of the guide wire 70 according to the first modified example has a housing tube 33 that slidably houses the puncture portion 15, and a wire fixing portion 31A that is continuously fixed to the inside of the housing tube 33 from the wire 31 forming the coil portion 32 toward the tip side. The second contact portion 39 is located on the surface on the tip side of the wire fixing portion 31A. Thereby, the second contact portion 39 located at the wire fixing portion 31A continuous from the coil portion 32 can be brought into contact with the first contact portion 16, and excessive elongation of the cover portion 30 can be satisfactorily restricted.

[0056] Also, like the guide wire 80 of the second modified example shown in FIG. 6(B), the inner peripheral surface of the housing tube 33 may have an inclined portion 33A that approaches the central axis X toward the base end side. The second contact portion 39 is located at the inclined portion 33A. The first contact portion 16 is located at the base end of the puncture portion 15.

[0057] As described above, the tip cover 30B of the guide wire 80 according to the second modification has a housing tube 33 that slidably houses the puncture portion 15. The housing tube 33 has an inclined portion 33A on its inner peripheral surface that approaches the central axis X toward the proximal end side, and the second contact portion 39 is located at the inclined portion 33A. Thereby, the second contact portion 39 of the inclined portion 33A of the tip cover 30B can be brought into contact with the first contact portion 16, and excessive elongation of the cover portion 30 can be satisfactorily restricted.

[0058] Also, as in the case of the guide wire 90 of the third modification shown in FIG. 6(C), the housing tube 33 may have a stepped portion 34A on its inner peripheral surface that approaches the central axis X, and the second contact portion 39 may be located at the stepped portion 34A. The first contact portion 16 is located at a large-diameter portion 11A of the shaft portion 11 that penetrates the stepped portion 34A and is located on the tip side of the stepped portion 34A. The outer diameter of the large-diameter portion 11A is larger than the inner diameter of the inner peripheral surface of the stepped portion 34A. Thereby, the large-diameter portion 11A cannot pass through the hole formed by the inner peripheral surface of the stepped portion 34A.

[0059] As described above, the tip cover 30B of the guide wire 90 according to the third modification has a stepped portion 34A on its inner peripheral surface that approaches the central axis X, the second contact portion 39 is located at the stepped portion 34A, and the first contact portion 16 is located at a large-diameter portion 11A that is disposed at the tip of the shaft portion 11 and has an outer diameter larger than that on the proximal end side. Thereby, the second contact portion 39 located at the stepped portion 34A of the tip cover 30B can be brought into contact with the first contact portion 16 of the shaft portion, and excessive elongation of the cover portion 30 can be satisfactorily restricted.

[0060] Also, as in the case of the guide wire 100 of the fourth modification shown in FIG. 6(D), the housing tube 33 has a stepped portion 34A as in the third modification, and the large-diameter portion 11A located at the tip of the shaft portion 11 may be separated from the puncture portion 15 toward the proximal end side. Thereby, when the second contact portion 39 located at the stepped portion 34A of the housing tube 33 comes into contact with the first contact portion 16 located at the large-diameter portion 11A, the force acting from the second contact portion 39 to the first contact portion 16 is not transmitted to the puncture portion 15. For this reason, the guide wire 100 can suppress the puncture portion 15 from falling off from the shaft portion 11.

[0061] This application is based on Japanese Patent Application No. 2019-038774 filed on March 4, 2019, the disclosure of which is incorporated herein by reference in its entirety.

Explanation of Reference Numerals

[0062] 10, 70, 80, 90, 100 guide wires 11 shaft portion 11A large-diameter portion 15 puncture portion 16 first contact portion 19 needle fixing portion 30 cover portion 30A curved portion 30B tip cover 31 wire 31A wire fixing portion 32 coil portion 33 housing tube 33A inclined portion 34 stopper 34A stepped portion 36 sparse pitch portion 39 second contact portion X central axis

Claims

1. A guide wire for guiding a tubular elongate body inserted into a living body, having an elongate shaft portion with flexibility, a puncture portion disposed at the distal end of the shaft portion for forming a hole in living tissue, and an elastic deformable cover portion covering the puncture portion, wherein the cover portion has a sparse pitch portion having a wire wound in a spiral and contractible along the central axis of the winding, and a non-deformable tip cover located on the tip side of the sparse pitch portion and capable of covering at least a part of the puncture portion without a gap, the shaft portion or the puncture portion has a first contact portion, the tip cover has a housing tube for slidably housing the puncture portion, a wire fixing portion continuously fixed to the inside of the housing tube from the wire forming the sparse pitch portion toward the tip side, and a second contact portion located on the proximal side with respect to the first contact portion and on the tip side surface of the wire fixing portion, and extends to the tip side from the second contact portion, a guide wire in which when the first contact portion contacts the second contact portion, relative axial movement between the first contact portion and the second contact portion is restricted.

2. The guide wire according to claim 1, wherein when moving in a direction in which the positions of the first contact portion and the second contact portion are separated, the puncture portion protrudes from the cover portion.

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