Guide wire

Abstract

To provide a guide wire capable of suppressing occurrence of blood vessel perforation while high insertability into a narrow section is provided.SOLUTION: The guide wire comprises a long wire body 110 and a lubricant coating layer 120 covering at least a part of the wire body 110 therewith. The wire body 110 includes a wire-body first constant-outer-diameter part 111 and a wire-body tapered part 112 adjacently disposed at the proximal end of the wire-body first constant-outer-diameter part 111. The lubricant coating layer 120 includes a first coating part 121 formed of material swellable in humectation, the first coating part 121 including a coating first constant-outer-diameter part 121a and a coating tapered part 121b adjacently disposed at the proximal end of the coating first constant-outer-diameter part 121a. In a state where the first coating part 121 is swelled, the distal end of the coating tapered part 121b is located further forward than the distal end of the wire-body tapered part 112.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a guide wire.

Background Art

[0002] In the diagnosis and treatment of lesions formed in blood vessels, procedures using catheters are performed. An operator inserts a guide wire into the blood vessel, brings the distal end of the guide wire to reach the lesion, and then inserts the catheter along the guide wire.

[0003] Guide wires are required to advance through curved portions and branched portions of blood vessels and pass through stenotic portions. Therefore, the distal end portion of a guide wire is required to have flexibility and penetration performance into stenotic portions. For example, Patent Document 1 discloses a guide wire having a core wire and a coil provided with a small-diameter equal-diameter portion and a tapered portion at the distal end of the core wire, in order to obtain high penetration performance into a stenotic portion without impairing operability.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of Invention

Problems to be Solved by the Invention

[0005] The guide wire of Patent Document 1 achieves high penetration performance into a stenotic portion by providing a small-diameter equal-diameter portion and a tapered portion at the distal end to reduce the outer diameter of the distal end portion of the guide wire.

[0006] However, a guide wire with a reduced-diameter distal end may get caught at the entrance of the stenotic portion at the tapered portion where the outer diameter increases from the distal end toward the proximal end, which may cause breakage of the guide wire.

[0007] Furthermore, if the surgeon attempts to insert the guidewire into the stenosis with excessive force, the tip of the guidewire may unintentionally advance, potentially causing vascular perforation by piercing the vascular wall in or beyond the stenosis.

[0008] At least one embodiment of the present invention has been made in view of the above circumstances, and specifically aims to provide a guidewire that has high insertion capability into stenotic areas while suppressing the occurrence of vascular perforation. [Means for solving the problem]

[0009] The above objectives of the present invention are achieved by any one of the following (1) to (8).

[0010] (1) A guide wire having a long wire body and a lubricating coating layer covering at least a portion of the wire body, wherein the wire body includes a first constant outer diameter portion of the wire body and a tapered portion of the wire body positioned adjacent to the base end of the first constant outer diameter portion of the wire body, the lubricating coating layer includes a first coating portion formed of a material capable of swelling when wet, the first coating portion includes a first constant outer diameter portion of the coating and a tapered portion of the coating positioned adjacent to the base end of the first constant outer diameter portion of the coating, and in a swollen state of the first coating portion, the tip of the tapered portion of the coating is located closer to the tip than the tip of the tapered portion of the wire body.

[0011] (2) The guide wire of (1), wherein the wire body includes a second constant outer diameter portion of the wire body positioned adjacent to the base end of the tapered portion of the wire body, and in a state in which the first coating portion is swollen, the base end of the coating tapered portion is located on the tip side of the tip of the second constant outer diameter portion of the wire body.

[0012] (3) The guide wire according to (1) or (2) above, wherein the first covering portion includes a second covering portion with a constant outer diameter that is positioned adjacent to the base end of the covering tapered portion, and when the first covering portion is swollen, the maximum value of the outer diameter of the first covering portion with a constant outer diameter is smaller than the maximum value of the outer diameter of the second covering portion with a constant outer diameter.

[0013] (4) Any guide wire of the above (1) to (3), wherein the lubricating coating layer includes a second coating portion that forms the tip of the guide wire, the second coating portion is made of a material that can swell when wet, and when the first coating portion and the second coating portion are swollen, the thickness of the second coating portion in the longitudinal direction is greater than the thickness of the first constant outer diameter coating portion of the first coating portion in the radial direction.

[0014] (5) The lubricating coating layer includes a second coating portion that forms the tip of the guide wire, The second coating portion is a guide wire of any of the above (1) to (3), which is made of a hydrophobic polymer.

[0015] (6) Any guide wire of the above (1) to (5), wherein, when the first coating portion is swollen, the minimum value of the radial thickness of the coating tapered portion in the wire body tapered portion is greater than or equal to the minimum value of the radial thickness of the first constant outer diameter coating portion.

[0016] (7) Any guide wire of the above (1) to (6), wherein the wire body includes a long core member and a coil arranged to cover the outer circumference of the tip of the core member, and at least the first constant outer diameter portion of the wire body and the tapered portion of the wire body are formed by the coil.

[0017] (8) A guide wire according to any of (1) to (6) above, wherein the wire body includes a long core member and a resin layer covering the outer circumference of the core member, and at least the outer circumference of the first constant outer diameter portion of the wire body and the outer circumference of the tapered portion of the wire body are formed by the resin layer. [Effects of the Invention]

[0018] According to one embodiment of the present invention, the guide wire has the distal end portion of the wire main body reduced in diameter by the constant outer diameter portion of the wire main body and the tapered portion of the wire main body, so that high penetration into a stenotic portion can be obtained. Further, in the lubricious coating layer covering the distal end portion of the wire main body, in a state where the lubricious coating layer is swollen, the distal end of the coating tapered portion is located closer to the distal end side than the distal end of the wire main body tapered portion. Therefore, when the guide wire is pushed into the stenotic portion, the distal end of the lubricious coating tapered portion comes into contact with the inlet of the stenotic portion before the distal end of the wire main body tapered portion. This makes it difficult for the distal end of the wire main body tapered portion to get caught on the inlet of the stenotic portion, so that damage to the guide wire is suppressed and the penetration into the stenotic portion is improved. In addition, since the lubricious coating layer of the guide wire is formed of a material that can swell when wet, even if the guide wire is pushed into the stenotic portion with an unnecessarily strong force, the elastic force of the lubricious coating layer reduces the excessive pushing force, and unintended advancement of the distal end portion can be suppressed. Furthermore, the operator can sensuously recognize that the distal end of the coating tapered portion of the lubricious coating layer has come into contact with the inlet of the stenotic portion by the elastic force of the lubricious coating layer, and thus can advance the guide wire carefully into the stenotic portion. Thereby, the guide wire can suppress the occurrence of vascular perforation. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] [Figure 1] It is a partially enlarged view around the distal end portion of the guide wire according to the first embodiment of the present invention. [Figure 2] It is a schematic cross-sectional view of the first configuration of the guide wire. [Figure 3] It is a schematic cross-sectional view of the second configuration of the guide wire. [Figure 4] It is a partially enlarged view around the distal end portion of the guide wire according to the second embodiment of the present invention. [Figure 5] It is a partially enlarged view around the distal end portion of the guide wire of Modification Example 1. [Figure 6] It is a partially enlarged view around the distal end portion of the guide wire of Modification Example 2. [Figure 7] It is a partially enlarged view around the distal end portion of the guide wire of Modification Example 3. [Mode for Carrying Out the Invention]

[0020] Hereinafter, modes for carrying out the present invention will be described in detail with reference to the drawings. The embodiments shown herein are illustrated to embody the technical idea of the present invention, and do not limit the present invention. Further, all other practicable modes, examples, operation techniques and the like that can be conceived by those skilled in the art without departing from the gist of the present invention are included in the scope and gist of the present invention, and are also included in the invention described in the claims and the equivalent scope thereof.

[0021] Furthermore, the drawings attached to the present specification may be schematically represented by appropriately modifying the scale, vertical and horizontal dimensional ratios, shapes and the like from the actual product for the convenience of illustration and easy understanding, but these are merely examples and do not limit the interpretation of the present invention.

[0022] In the present specification, for convenience of explanation, the following directions are defined. In Figure 1, the "longitudinal direction" is the direction along the central axis C of the guide wire 100. The "radial direction" is the direction away from or approaching the central axis C in a cross section perpendicular to the axis (transverse cross section) with the central axis C of the guide wire 100 as the reference axis. The "circumferential direction" is the rotational direction around the central axis C of the guide wire 100 as the reference axis.

[0023] The side on which the guide wire 100 is inserted into a blood vessel is defined as the "distal end side", and the side opposite to the distal end side (the side gripped by the operator) is defined as the "proximal end side". In addition, the portion including a certain range along the longitudinal direction from the distal end (the most distal end) is referred to as the "distal end portion", and the portion including a certain range along the longitudinal direction from the proximal end (the most proximal end) is referred to as the "proximal end portion".

[0024] In the following description, ordinal numbers such as "first" and "second" are used for convenience unless otherwise specified, and do not prescribe any particular order.

[0025] The guidewire 100 according to the present invention is a medical device inserted into a blood vessel to guide a catheter or stent to a lesion for endovascular treatment. The guidewire 100 can also be inserted into other biological tubules (such as blood vessels, ureters, bile ducts, fallopian tubes, and hepatic ducts) depending on the treatment purpose.

[0026] [First Embodiment] A guide wire 100 according to the first embodiment will be described.

[0027] As shown in Figure 1, the guide wire 100 has a long wire body 110 and a lubricating coating layer 120 that covers at least a portion of the wire body 110.

[0028] <Wire body> The wire body 110 is composed of at least the following, arranged in order from the tip to the base: a first constant outer diameter portion 111 of the wire body; a tapered portion 112 of the wire body, which is adjacent to the base end of the first constant outer diameter portion 111 and whose outer diameter decreases from the base end to the tip; and a second constant outer diameter portion 113 of the wire body, which is adjacent to the base end of the tapered portion 112.

[0029] The outer shape of the wire body tapered section 112 is a linear tapered shape in which the outer diameter of the wire body 110 changes linearly along the long axis direction of the wire body 110, and the taper angle (the rate of decrease in outer diameter from the base to the tip) is constant. However, the outer shape of the wire body tapered section 112 may also be an exponential tapered shape in which the outer diameter of the wire body 110 changes exponentially along the long axis direction of the wire body 110, a parabolic tapered shape in which the outer diameter of the wire body 110 is proportional to the square root of the distance from the tip of the wire body tapered section 112, and the overall shape is a parabola with the tip of the wire body tapered section 112 as its vertex, or a hyperbolic tangent shape formed by an S-shaped curve along the long axis direction of the wire body 110. Furthermore, the wire body tapered section 112 may include multiple tapers with different taper angles and taper shapes. If the wire body tapered section 112 is composed of multiple tapers, the tapers of the wire body tapered section 112 may be arranged continuously, or sections with a constant outer diameter may be placed between the tapers.

[0030] The outer diameter of the first constant outer diameter section 111 of the wire body is smaller than the outer diameter of the second constant outer diameter section 113 of the wire body. Therefore, the guide wire 100 can be inserted into constricted areas with high passability. From the viewpoint of passability into constricted areas, the outer diameter of the first constant outer diameter section 111 of the wire body can be set in the range of 0.1 mm to 0.9 mm, and the outer diameter of the second constant outer diameter section 113 of the wire body can be set in the range of 0.2 mm to 1.0 mm.

[0031] The wire body 110 can adopt known configurations, such as a first coil type configuration (guide wire 100A) in which a coil (tubular body 20A) is provided on a core member 10 as shown in Figure 2, or a second jacket type configuration (guide wire 100B) in which the entire core member 10 is covered with a resin layer 20B as shown in Figure 3. Below, the configurations of guide wires 100A and 100B will be described as examples of the guide wire 100 of the present invention.

[0032] <First form> The configuration of the first embodiment of the guide wire 100 according to the present invention will be described with reference to Figure 2.

[0033] As shown in Figure 2, the guide wire 100A has a wire body 110A and a covering layer 40A that covers at least a portion of the wire body 110A. The wire body 110A includes a long core member 10A, a tubular body 20A that covers the area around the tip of the core member 10A, and a fixing part 30A that fixes the tubular body 20A to the core member 10A.

[0034] The core member 10A comprises a first core portion 11A and a second core portion 12A positioned on the base end side of the first core portion 11A and joined to the first core portion 11A. The first core portion 11A is a long member extending along the long axis from the tip of the second core portion 12A toward the tip side of the guide wire 100A. The second core portion 12A is a long member extending from the base end of the first core portion 11A toward the base end side of the guide wire 100A. The first core portion 11A and the second core portion 12A can be joined by welding, brazing, or soldering. The first core portion 11A and the second core portion 12A may also be connected using a cylindrical connecting member. The core member 10A may also be formed from a single continuous member.

[0035] The core member 10A can be formed from a known material applicable to guide wires, such as a superelastic alloy like a nickel-titanium alloy or stainless steel. Preferably, the first core portion 11A is formed from a material with lower rigidity than the second core portion 12A. However, the first core portion 11A and the second core portion 12A may be formed from the same material.

[0036] The lumen 20A is a coil formed by spirally winding a wire around the core member 10A. The lumen 20A is formed by a first coil 21A positioned at the tip of the first core portion 11A, and a second coil 22A positioned at the base end of the first coil 21A and coaxially positioned with the first core portion 11A. The first core portion 11A and the second coil 22A surround the first core portion 11A of the core member 10A and are fixed to the first core portion 11A. The first coil 21A has the first constant outer diameter portion 111, the tapered portion 112, and the second constant outer diameter portion 113 of the wire body as described above in the guide wire 100. Therefore, the outer diameter of the tip of the first coil 21A is smaller than the outer diameter of the base end. It is preferable that the outer diameter of the second coil 22A is constant from the tip to the base end. The lumen 20A may be formed by one coil or by three or more coils. Furthermore, the first constant outer diameter portion 111, the tapered portion 112, and the second constant outer diameter portion 113 of the wire body in the guide wire 100A may be formed in locations other than the first coil 21A of the lumen 20A.

[0037] The outer diameter of the wire forming the first coil 21A is larger than the outer diameter of the wire forming the second coil 22A. The cross-sectional shape of the wires forming the first coil 21A and the second coil 22A is preferably circular, but it may also be elliptical or polygonal. Furthermore, the wires forming the first coil 21A and the second coil 22A may be not only a single wire, but also a stranded wire consisting of two or more wires.

[0038] The wires forming the first coil 21A and the second coil 22A of the tubular body 20A can be made of materials such as stainless steel, superelastic alloys, cobalt-based alloys, gold, platinum, tungsten, or alloys containing these metals. In particular, it is preferable that the wire forming the first coil 21A be made of a radiopaque material. This improves the visibility of the guidewire 100A under fluoroscopy.

[0039] The material, outer diameter, cross-sectional shape, and pitch of the wires forming the first coil 21A and second coil 22A of the tubular body 20A can be appropriately selected according to the purpose of the guide wire 100A.

[0040] The fixing portion 30A is a member for fixing the tubular body 20A to the core member 10A. The fixing portion 30A includes a tip fixing portion 31A for fixing the tip of the tubular body 20A to the core member 10A, an intermediate fixing portion 32A for fixing the middle part of the tubular body 20A to the core member 10A, and a base fixing portion 33A for fixing the base end of the tubular body 20A to the core member 10A.

[0041] The material used to form the fixing portion 30A is brazing material or solder. Brazing materials include gold brazing material and silver brazing material. Solders include tin-silver alloy solder and tin-lead alloy solder. The material used to form the fixing portion 30A may also be adhesive.

[0042] The coating layer 40A includes a lubricating coating layer 41A and a proximal coating layer 42A formed on the proximal side of the lubricating coating layer 41A. The coating layer 40A is formed to cover the wire body 110A and improves the operability and safety of the guide wire 100A by reducing friction between the guide wire 100A and the blood vessel or catheter.

[0043] The lubricating coating layer 41A covers each part (luminous body 20A, fixing part 30A) provided on the first core part 11A and a part of the first core part 11A. The proximal coating layer 42A covers the portion of the core member 10A that is located on the proximal side of the luminous body 20A. The proximal coating layer 42A may also cover the second core part 12A.

[0044] The lubricating coating layer 41A can be formed from a hydrophilic polymer. Examples of hydrophilic polymers that form the lubricating coating layer 41A include cellulose-based polymers, polyethylene oxide-based polymers, maleic anhydride-based polymers (e.g., maleic anhydride copolymers such as methyl vinyl ether-maleic anhydride copolymer), acrylamide-based polymers (e.g., polyacrylamide, glycidyl methacrylate-dimethylacrylamide block copolymer), water-soluble nylon, polyvinyl alcohol, polyvinylpyrrolidone, and their derivatives. In particular, it is preferable that the lubricating coating layer 41A be formed from a material that swells to form a hydrogel when wet. Because the hydrogel has appropriate elasticity, it can mitigate the impact when the guidewire 100A comes into contact with the blood vessel wall.

[0045] The base end coating layer 42A can be formed from a low-friction material. Suitable low-friction materials include fluororesins (PTFE, ETFE, etc.) and silicone resins.

[0046] <Second form> Next, with reference to Figure 3, the configuration of the second embodiment of the guide wire 100 according to the present invention will be described.

[0047] As shown in Figure 3, the guide wire 100B comprises a wire body 110B and a lubricating coating layer 30B that covers at least a portion of the wire body 110B. The wire body 110B includes a core member 10B that extends in the longitudinal direction and a resin layer 20B that covers the core member 10B.

[0048] The core member 10B includes a first core portion 11B having a tapered shape in which the outer diameter increases from the tip to the base, at least in part, and a second core portion 12B positioned adjacent to the base of the first core portion 11B and having a constant outer diameter along the long axis. The first core portion 11B and the second core portion 12B are formed from a single continuous member. The core member 10B may also be formed by joining the first core portion 11B and the second core portion 12B by welding, brazing, or soldering.

[0049] The core member 10B can be formed from a material applicable to the aforementioned core member 10A.

[0050] The resin layer 20B is formed to cover the entire core member 10B. The tip of the resin layer 20B has a rounded shape.

[0051] The resin layer 20B is preferably formed from a highly flexible material, such as polyethylene, polyolefins such as polypropylene, polyvinyl chloride, polyester (PET, PBT, etc.), polyamide, polyimide, polyurethane, polystyrene, polycarbonate, silicone resin, fluororesin (PTFE, ETFE, PFA, etc.), or composite materials thereof, or various rubber materials such as latex rubber, silicone rubber, or composite materials combining two or more of these.

[0052] The thickness of the resin layer 20B is not particularly limited. Furthermore, the resin layer 20B is not limited to a single-layer structure, but may also have a multi-layer structure.

[0053] The lubricating coating layer 30B is formed to cover at least a portion of the resin layer 20B, thereby reducing friction between the guidewire 100B and blood vessels or catheters, and improving the operability and safety of the guidewire 100B. Furthermore, by coating the resin layer 20B with the lubricating coating layer 30B, the resistance to peeling is improved compared to when it is directly coated onto the core member 10B.

[0054] The lubricating coating layer 30B can be formed from a material applicable to the aforementioned lubricating coating layer 41A.

[0055] The guidewire 100B may be provided with a marker portion at the tip of the first core portion 11B. The marker portion is provided by fixing a coil or cylindrical body made of a radiopaque material to the vicinity of the tip of the first core portion 11B via a fixing material such as adhesive or solder. Examples of radiopaque materials include precious metals such as gold, platinum, and tungsten, or alloys containing these (e.g., platinum-iridium alloy). By providing a marker portion at the tip of the first core portion 11B, the visibility of the guidewire 100B under radiofluoroscopy is improved.

[0056] The guidewire 100 according to the present invention is characterized by the shape of its lubricating coating layer 120 in order to suppress vascular perforation. The lubricating coating layer 120 corresponds to the lubricating coating layer 41A of guidewire 100A and the lubricating coating layer 30B of guidewire 100B. The lubricating coating layer 120 according to the present invention will be described below.

[0057] <Lubricating coating layer> The lubricating coating layer 120 includes a first coating portion 121 and a second coating portion 122. The lubricating coating layer 120 is formed of a material that is capable of swelling when wet, at least in part.

[0058] <First covering section> The first coating portion 121 is a portion of the lubricating coating layer 120 that covers a predetermined area of ​​the tip of the wire body 110, from the base end to the tip of the wire body 110. As shown in Figure 1, the first coating portion 121 has a first constant outer diameter coating portion 121a, a tapered coating portion 121b positioned adjacent to the base end of the first constant outer diameter coating portion 121a, and a second constant outer diameter coating portion 121c positioned adjacent to the base end of the tapered coating portion 121b.

[0059] The first coating portion 121 is formed of a material that can swell when wet. The material that can swell when wet is preferably a hydrophilic polymer applicable to the lubricating coating layer 41A of the first embodiment of the guide wire 100A described above.

[0060] The first constant outer diameter portion 121a of the wire body is a portion that covers a predetermined range from the base end side of the first constant outer diameter portion 111 of the wire body toward the base end of the first constant outer diameter portion 111 of the wire body. When the lubricating coating layer 120 is swollen, the radial thickness d2 of the first constant outer diameter portion 121a of the wire body is substantially constant along the long axis. In this specification, the thickness of the lubricating coating layer 120 is the thickness when the material forming the lubricating coating layer 120 is swollen when wet.

[0061] The tapered coating portion 121b is the portion that covers a predetermined area from the tip to the base end of the first constant outer diameter portion 111 of the wire body and the tapered portion 112 of the wire body, which is on the base end side of the first constant outer diameter portion 121a of the coating. The tapered coating portion 121b is smoothly connected to the first constant outer diameter portion 121a of the coating. When the lubricating coating layer 120 is swollen, the radial thickness d1 of the tapered coating portion 121b in the tapered portion 112 of the wire body is substantially constant along the long axis. Therefore, the outer shape of the tapered coating portion 121b in the tapered portion 112 of the wire body follows the shape of the tapered portion 112 of the wire body. In this embodiment, as shown in Figure 1, the outer shape of the coated tapered portion 121b has a tapered shape in which the outer diameter r2 of the coated tapered portion 121b decreases from the base end to the tip of the guide wire 100, and the taper angle of the coated tapered portion 121b is substantially the same as the taper angle of the wire body tapered portion 112.

[0062] The second constant outer diameter portion 121c of the covering is a portion that covers a predetermined range from the tip to the base end of the wire body tapered portion 112 and the second constant outer diameter portion 113 of the wire body, which are located on the base end side of the covering tapered portion 121b. The second constant outer diameter portion 121c of the covering is smoothly connected to the covering tapered portion 121b. When the lubricating coating layer 120 is swollen, the radial thickness of the second constant outer diameter portion 121c of the covering in the wire body second constant outer diameter portion 113 is substantially constant along the long axis.

[0063] When the lubricating coating layer 120 is swollen, the tip of the coated tapered portion 121b is located further forward than the tip of the wire body tapered portion 112. In other words, the tip of the coated tapered portion 121b is located further forward than the base end of the wire body first constant outer diameter portion 111.

[0064] As a result, when the guidewire 100 is pushed into the constricted area, the tip of the coated tapered portion 121b contacts the entrance of the constricted area before the tip of the wire body tapered portion 112. This makes it less likely for the tip of the wire body tapered portion 112 of the guidewire 100 to get caught at the entrance of the constricted area, thus suppressing damage to the guidewire 100 and improving ease of insertion into the constricted area. Furthermore, since the lubricating coating layer 120 of the guidewire 100 is formed of a hydrophilic polymer that can swell when wet, even if it is pushed into the constricted area with excessive force, the elastic force of the lubricating coating layer 120 weakens the excessive pushing force, preventing the tip from advancing unintentionally. In addition, the operator can intuitively sense when the tip of the coated tapered portion 121b of the lubricating coating layer 120 has contacted the entrance of the constricted area due to the elastic force of the lubricating coating layer 120, allowing the guidewire 100 to be advanced carefully into the constricted area. This allows the guidewire 100 to prevent vascular perforation.

[0065] When the wire body 110 of the guide wire 100 has a coil-type configuration (wire body 110A), the tip of the tapered portion 121b of the first covering portion 121 is located closer to the tip than the tip of the tapered portion 112 of the wire body, making it less likely for the coil forming the tapered portion 112 of the wire body to get caught in the constricted section. Therefore, the first covering portion 121 can effectively prevent the coil forming the tapered portion 112 of the wire body from getting caught and damaged at the entrance of the constricted section.

[0066] As shown in Figure 1, when the lubricating coating layer 120 is swollen, the base end of the coated tapered portion 121b is located closer to the tip than the tip of the wire body's second constant outer diameter portion 113. That is, the base end of the coated tapered portion 121b is located closer to the tip than the base end of the wire body's tapered portion 112. In Figure 1, the positions of the tip and base end of the coated tapered portion 121b are indicated by dotted lines, and the positions of the tip and base end of the wire body's tapered portion 112 are indicated by solid lines.

[0067] As a result, when the guide wire 100 is pushed into the constricted section, the base end of the lubricated tapered section 121b contacts the entrance to the constricted section before the base end of the tapered section 112 of the wire body. This prevents the tip of the second constant outer diameter section 113 of the wire body from getting caught at the entrance to the constricted section, improving the ease of insertion into the constricted section.

[0068] When the lubricating coating layer 120 is swollen, the minimum value of the radial thickness d1 of the coated tapered portion 121b in the wire body tapered portion 112 is greater than or equal to the minimum value of the radial thickness d2 of the coated first constant outer diameter portion 121a.

[0069] As a result, the guide wire 100 has high lubricity in the coated tapered portion 121b, further improving its ability to pass through constricted areas.

[0070] In a state where the lubricating coating layer 120 is swollen, it is preferable that the maximum value of the radial thickness d2 of the first constant outer diameter coating portion 121a is less than or equal to the minimum value of the radial thickness d1 of the coating tapered portion 121b in the wire body tapered portion 112. More preferably, the maximum value of the radial thickness d2 of the first constant outer diameter coating portion 121a is smaller than the minimum value of the radial thickness d1 of the coating tapered portion 121b in the wire body tapered portion 112. As a result, the outer diameter of the tip of the guide wire 100 can be reduced, further improving its ability to pass through constricted sections.

[0071] When the lubricating coating layer 120 is swollen, the maximum value of the outer diameter r1 of the first constant outer diameter portion 121a is smaller than the maximum value of the outer diameter r3 of the second constant outer diameter portion 121c. As a result, the outer diameter of the tip of the guide wire 100 can be reduced, further improving its ability to pass through constricted areas.

[0072] <Second covering section> The second coating portion 122 is the portion of the lubricating coating layer 120 that is closer to the tip than the first coating portion 121. The second coating portion 122 covers the tip of the wire body 110 and forms the tip of the guide wire 100.

[0073] The base end of the second covering portion 122 is smoothly connected to the tip of the first covering portion 121. The radial thickness of the second covering portion 122 is approximately constant along the long axis. The radial thickness of the second covering portion 122 is approximately the same as the radial thickness d2 of the first constant outer diameter covering portion 121a of the first covering portion 121 that is connected to the base end of the second covering portion 122. In Figure 1, the positions of the tip of the first covering portion 121 and the base end of the second covering portion 122 are indicated by the dashed lines.

[0074] In this embodiment, the first covering portion 121 and the second covering portion 122 are integrally formed from the same material. Therefore, the second covering portion 122 is made of a material that can swell when wet. The base end of the second covering portion 122 and the tip end of the first covering portion 121 may be formed to be spaced apart from each other.

[0075] The guidewire 100 has elasticity and high lubricity at its tip due to the second covering portion 122. Therefore, the guidewire 100 can suppress vascular perforation as it advances through the blood vessel toward the stenosis, and its maneuverability is improved in curved and bifurcated sections of the blood vessel.

[0076] The lubricating coating layer 120 may have coating portions other than the first coating portion 121 and the second coating portion 122. Furthermore, the radial thickness of the first coating portion 121 and the second coating portion 122 of the lubricating coating layer 120 may vary along the longitudinal axis.

[0077] [Second Embodiment] Next, a second embodiment of the guide wire according to the present invention will be described. In the following description, the differences from the previously described embodiment will be mainly explained, and components that have the same function as those of the other embodiment will be denoted by the same or related reference numerals, and detailed explanations will be omitted and they will not be specifically mentioned.

[0078] The guide wire 100C according to the second embodiment will be described with reference to Figure 4. The guide wire 100C of the second embodiment differs from that of the first embodiment in the position where the tapered portion 121Cb of the first covering portion 121C is formed.

[0079] The wire body 110 of the guide wire 100C may be configured as either the coil-type wire body 110A (see Figure 2) as shown in the first embodiment described above, or the jacket-type wire body 110B (see Figure 3) as shown in the second embodiment.

[0080] The lubricating coating layer 120C includes a first coating portion 121C and a second coating portion 122C.

[0081] The first coating portion 121C includes a first constant outer diameter coating portion 121Ca, a tapered coating portion 121Cb positioned adjacent to the base end of the first constant outer diameter coating portion 121Ca, and a second constant outer diameter coating portion 121Cc positioned adjacent to the base end of the tapered coating portion 121Cb.

[0082] The first constant outer diameter section 121Ca is a portion that covers a predetermined range from the base end side of the first constant outer diameter section 111 of the wire body towards the base end of the first constant outer diameter section 111 of the wire body.

[0083] The coated tapered portion 121Cb is the portion that covers the first outer diameter constant portion 111 and the wire body tapered portion 112 on the base end side of the coated first outer diameter constant portion 121Ca.

[0084] The second constant outer diameter section 121Cc is the portion that covers a predetermined range from the tip to the base end of the second constant outer diameter section 113 of the wire body.

[0085] In the longitudinal direction, the base end of the tapered coating portion 121Cb of the first coating portion 121C substantially coincides with the base end of the tapered portion 112 of the wire body, as shown in Figure 4. The tip of the tapered coating portion 121Cb is located further forward than the tip of the tapered portion 112 of the wire body, as shown in Figure 4. That is, the tip of the tapered coating portion 121Cb is located further forward than the base end of the first constant outer diameter portion 111 of the wire body. In Figure 4, the positions of the tip and base end of the tapered coating portion 121Cb and the position of the base end of the tapered portion 112 of the wire body are indicated by dotted lines, and the position of the tip of the tapered portion 112 of the wire body is indicated by a solid line.

[0086] When the lubricating coating layer 120 is swollen, the thickness d1 of the coated tapered portion 121Cb increases from the base end to the tip, and the outer diameter r2 of the coated tapered portion 121Cb decreases from the base end to the tip. Therefore, the taper angle of the coated tapered portion 121Cb is smaller than the taper angle of the wire body tapered portion 112.

[0087] When the lubricating coating layer 120C is swollen, the minimum value of the radial thickness d1 of the coated tapered portion 121Cb in the wire body tapered portion 112 is greater than or equal to the minimum value of the radial thickness d2 of the coated first constant outer diameter portion 121Ca.

[0088] The second coating portion 122C is the portion of the lubricating coating layer 120C that is closer to the tip than the first coating portion 121C. The second coating portion 122C covers the tip of the wire body 110 and forms the tip of the guide wire 100C. The second coating portion 122C has a substantially constant thickness in the radial direction.

[0089] In the second embodiment, the guide wire 100C has a base end of the coated tapered portion 121Cb that substantially coincides with the base end of the wire body tapered portion 112, and the tip of the coated tapered portion 121Cb is located further forward than the tip of the wire body tapered portion 112. Therefore, when the guide wire 100C is pushed into a constricted area, the tip of the coated tapered portion 121Cb contacts the entrance to the constricted area before the tip of the wire body tapered portion 112. Since the lubricating coating layer 120C is made of a hydrophilic polymer that can swell when wet, even if the guide wire 100C is pushed into a constricted area with excessive force, the elastic force of the lubricating coating layer 120C weakens the excessive pushing force. Therefore, the guide wire 100C can suppress unintended advancement of its tip. Furthermore, the surgeon can intuitively sense when the tip of the tapered portion 121Cb of the lubricating coating layer 120C has come into contact with the entrance to the stenosis, allowing them to carefully advance the guidewire 100C into the stenosis. Therefore, the guidewire 100C can suppress the occurrence of vascular perforation.

[0090] Furthermore, as shown in Figure 4, the base end of the coated tapered portion 121Cb is approximately coincident with the base end of the wire body tapered portion 112, and the tip is located further forward than the tip of the wire body tapered portion 112. As a result, the radial thickness d1 of the coated tapered portion 121Cb in the wire body tapered portion 112 increases from the base end towards the tip. Consequently, the first coated portion 121C has a greater radial thickness around the boundary between the wire body first constant outer diameter portion 111 and the wire body tapered portion 112, where the outer diameter of the wire body 110 changes. As a result, the guide wire 100C has improved lubricity around the boundary between the wire body first constant outer diameter portion 111 and the wire body tapered portion 112, and excessive pushing force can be effectively reduced. Furthermore, since the tapered angle of the covered tapered portion 121Cb of the guidewire 100C is smaller than the tapered angle of the wire body tapered portion 112, the wire body tapered portion 112 is prevented from getting caught at the entrance of the stenosis. As a result, the guidewire 100C can have high insertion ability into the stenosis while preventing the tip from unintentionally advancing and causing vascular perforation.

[0091] [Example of modification] The guide wires 100 and 100C of the present invention can also be implemented with appropriate modifications as shown in the following Modification 1 to Modification 3. Although the figures shown in each modification show modifications based on the configuration of the guide wire 100 of the first embodiment, they are also applicable to the guide wire 100C of the second embodiment. Furthermore, each of the modified examples shown below can be implemented by appropriately selecting necessary configurations from the configurations shown in each modification and combining them with other embodiments, without departing from the spirit of the present invention.

[0092] <Variation 1> Figure 5 is an enlarged view of the area around the tip of the guide wire 100D of Modified Example 1. As shown in Figure 5, the guide wire 100D of Modified Example 1 has a configuration in which the lubricating coating layer 120D has only the first coating portion 121D.

[0093] As shown in Figure 5, the first coating portion 121D includes a first constant outer diameter coating portion 121Da, a tapered coating portion 121Db positioned adjacent to the base end of the first constant outer diameter coating portion 121Da, and a second constant outer diameter coating portion 121Dc positioned adjacent to the base end of the tapered coating portion 121Db.

[0094] The first constant outer diameter covering portion 121Da is a portion that covers a predetermined range from the base end side of the first constant outer diameter covering portion 111 of the wire body towards the base end of the first constant outer diameter covering portion 111 of the wire body.

[0095] The coated tapered portion 121Db is the portion that covers a predetermined area from the tip to the base end of the first outer diameter constant portion 111 and the wire body tapered portion 112, which are located on the base end side of the coated first outer diameter constant portion 121Da.

[0096] The second constant outer diameter section 121Dc is a portion that covers a predetermined range from the tip to the base end of the wire body tapered section 112 and the second constant outer diameter section 113, which are located on the base end side of the covering tapered section 121Db.

[0097] When the lubricating coating layer 120D is swollen, the tip of the coated tapered portion 121Db is located further forward than the tip of the wire body tapered portion 112. In other words, the tip of the coated tapered portion 121Db is located further forward than the base end of the wire body first constant outer diameter portion 111.

[0098] When the lubricating coating layer 120D is swollen, the minimum value of the radial thickness d1 of the coating tapered portion 121Db in the wire body tapered portion 112 is greater than or equal to the minimum value of the radial thickness d2 of the coating first constant outer diameter portion 121Da.

[0099] In the modified example 1, the guide wire 100D has the tip of the coated tapered portion 121Db positioned further forward than the tip of the wire body tapered portion 112. Therefore, like the guide wire 100 in the first embodiment and the guide wire 100C in the second embodiment, the guide wire 100D can suppress the unintended advance of its tip and cause vascular perforation.

[0100] Furthermore, since the guide wire 100D does not have a second covering portion 122, its tip has lower lubricity compared to the guide wire 100 which has a second covering portion 122. For this reason, the guide wire 100D can reliably grasp the entrance to the constricted area.

[0101] <Variation 2> Figure 6 is an enlarged view of the area around the tip of the guide wire 100E of Modified Example 2. As shown in Figure 6, the guide wire 100E of Modified Example 2 has a lubricating coating layer 120E consisting of a first coating portion 121E and a second coating portion 122E.

[0102] As shown in Figure 6, the first coating portion 121E includes a first constant outer diameter coating portion 121Ea, a tapered coating portion 121Eb positioned adjacent to the base end of the first constant outer diameter coating portion 121Ea, and a second constant outer diameter coating portion 121Ec positioned adjacent to the base end of the tapered coating portion 121Eb.

[0103] The first constant outer diameter covering portion 121Ea is a portion that covers a predetermined range from the base end side of the first constant outer diameter covering portion 111 of the wire body towards the base end of the first constant outer diameter covering portion 111 of the wire body.

[0104] The coated tapered portion 121Eb is the portion that covers a predetermined area from the tip to the base end of the first coated constant outer diameter portion 111 and the wire body tapered portion 112, which are located on the base end side of the coated first constant outer diameter portion 121Ea.

[0105] The second constant outer diameter section 121Ec is a portion that covers a predetermined range from the tip to the base end of the wire body tapered section 112 and the second constant outer diameter section 113, which are located on the base end side of the covering tapered section 121Eb.

[0106] When the lubricating coating layer 120E is swollen, the tip of the coated tapered portion 121Eb is located further forward than the tip of the wire body tapered portion 112. In other words, the tip of the coated tapered portion 121Eb is located further forward than the base end of the wire body first constant outer diameter portion 111.

[0107] When the lubricating coating layer 120E is swollen, the minimum value of the radial thickness d1 of the coated tapered portion 121Eb in the wire body tapered portion 112 is greater than or equal to the minimum value of the radial thickness d2 of the coated first constant outer diameter portion 121Ea.

[0108] The second coating portion 122E is the portion of the lubricating coating layer 120E that is closer to the tip than the first coating portion 121E. The second coating portion 122E covers the tip of the wire body 110 and forms the tip of the guide wire 100E. The base end of the second coating portion 122E is smoothly connected to the tip of the first coating portion 121E. The radial thickness of the second coating portion 122E is approximately constant along the long axis. The radial thickness of the second coating portion 122E is approximately the same as the radial thickness d2 of the first constant outer diameter coating portion 121Ea of the first coating portion 121E that is connected to the base end of the second coating portion 122E.

[0109] The thickness d3 in the longitudinal direction of the second coating portion 122E at the tip of the guide wire 100E is greater than the radial thickness d2 of the first constant outer diameter coating portion 121Ea. Therefore, the thickness d3 in the longitudinal direction of the second coating portion 122E is greater than the radial thickness. As shown in Figure 6, the thickness d3 in the longitudinal direction of the second coating portion 122E is the thickness from the very tip of the first constant outer diameter portion 111 of the wire body to the very tip of the second coating portion 122E.

[0110] In the modified example 2, the guidewire 100E has a longitudinal thickness d3 of the second covering portion 122E that is greater than the radial thickness d2 of the first constant outer diameter covering portion 121Ea. This allows the guidewire 100E to have high elasticity and high lubricity at its tip due to the lubricating coating layer 120E. Furthermore, the surgeon can intuitively sense when the tip of the guidewire 100E has come into contact with the blood vessel wall or the entrance to the stenosis due to the second covering portion 122E, allowing them to carefully advance the guidewire 100. Therefore, as the guidewire 100E progresses through the blood vessel toward the stenosis, vascular perforation can be suppressed, and maneuverability at curved and bifurcated sections of the blood vessel is improved.

[0111] <Variation 3> Figure 7 is an enlarged view of the area around the tip of the guide wire 100F of Modified Example 3. As shown in Figure 7, the guide wire 100F of Modified Example 3 has a lubricating coating layer 120F, which consists of a first coating portion 121F and a second coating portion 122F.

[0112] As shown in Figure 7, the first covering portion 121F includes a first covering portion with a constant outer diameter 121Fa, a covering tapered portion 121Fb positioned adjacent to the base end of the first covering portion with a constant outer diameter 121Fa, and a second covering portion with a constant outer diameter 121Fc positioned adjacent to the base end of the covering tapered portion 121Fb.

[0113] The first constant outer diameter covering portion 121Fa is a portion that covers a predetermined range from the base end side of the first constant outer diameter covering portion 111 of the wire body towards the base end of the first constant outer diameter covering portion 111 of the wire body.

[0114] The coated tapered portion 121Fb is the portion that covers a predetermined area from the tip to the base end of the first coated constant outer diameter portion 111 and the wire body tapered portion 112, which are located on the base end side of the coated first constant outer diameter portion 121Fa.

[0115] The second constant outer diameter section 121Fc is a portion that covers a predetermined range from the tip to the base end of the wire body tapered section 112 and the second constant outer diameter section 113, which are located on the base end side of the covering tapered section 121Fb.

[0116] When the lubricating coating layer 120F is swollen, the tip of the coated tapered portion 121Fb is located further forward than the tip of the wire body tapered portion 112. In other words, the tip of the coated tapered portion 121Fb is located further forward than the base end of the wire body first constant outer diameter portion 111.

[0117] When the lubricating coating layer 120F is swollen, the minimum value of the radial thickness d1 of the coated tapered portion 121Fb in the wire body tapered portion 112 is greater than or equal to the minimum value of the radial thickness d2 of the coated first constant outer diameter portion 121Fa.

[0118] The first coating portion 121F is formed of a hydrophilic polymer having lubricating properties. The hydrophilic polymer can preferably be a material that swells when wet, which is applicable to the lubricating coating layer 41A of the first embodiment of the guide wire 100A described above.

[0119] The second coating portion 122F is formed of a hydrophobic polymer with lubricating properties. A silicone resin or the like can be suitably used as the hydrophobic polymer.

[0120] In the modified example 3, the guide wire 100F has a second covering portion 122F made of a hydrophobic polymer, which moderately suppresses the lubrication of the tip and allows it to reliably grasp the entrance to the constricted area.

[0121] The formation order of the first covering portion 121F and the second covering portion 122F is not particularly limited. The second covering portion 122F may be formed after the first covering portion 121F, or the first covering portion 121F may be formed after the second covering portion 122F. The second covering portion 122F can also be formed by covering the wire body 110 with the material for forming the first covering portion 121F up to the formation area of ​​the second covering portion 122F, removing the first covering portion 121F present in the formation area of ​​the second covering portion 122F, and then covering it with the material for forming the second covering portion 122F.

[0122] [Effects and Effects] As described above, the guide wire 100 according to the present invention comprises a long wire body 110 and a lubricating coating layer 120 covering at least a portion of the wire body 110. The wire body 110 includes a wire body first constant outer diameter portion 111 and a wire body tapered portion 112 positioned adjacent to the base end of the wire body first constant outer diameter portion 111. The lubricating coating layer 120 includes a first coating portion 121 made of a material that can swell when wet. The first coating portion 121 includes a coated first constant outer diameter portion 121a and a coated tapered portion 121b positioned adjacent to the base end of the coated first constant outer diameter portion 121a. When the first coating portion 121 is swollen, the tip of the coated tapered portion 121b is located closer to the tip than the tip of the wire body tapered portion 112.

[0123] With this configuration, the guide wire 100 has a reduced diameter at the tip due to the wire body's first constant outer diameter section 111 and the wire body's tapered section 112, thus providing high passability into constricted sections. Furthermore, when the lubricating coating layer 120 covering the tip of the wire body 110 is swollen, the tip of the coating tapered section 121b is located further forward than the tip of the wire body's tapered section 112. Therefore, when the guide wire 100 is pushed into a constricted section, the tip of the lubricating coating tapered section 121b contacts the entrance of the constricted section before the tip of the wire body's tapered section 112. As a result, the tip of the wire body's tapered section 112 is less likely to get caught at the entrance of the constricted section, thus suppressing damage to the guide wire 100 and improving its passability into constricted sections. Furthermore, since the guidewire 100 is formed of a material whose lubricating coating layer 120 is capable of swelling when wet, even if it is pushed into the stenosis with excessive force, the elastic force of the lubricating coating layer 120 weakens the excessive pushing force, preventing the tip from advancing unintentionally. In addition, the operator can intuitively sense when the tip of the tapered portion 121b of the lubricating coating layer 120 has come into contact with the entrance to the stenosis due to the elastic force of the lubricating coating layer 120, allowing the guidewire 100 to be advanced carefully into the stenosis. As a result, the guidewire 100 can prevent vascular perforation.

[0124] Furthermore, the wire body 110 of the guide wire 100 includes a second constant outer diameter portion 113 of the wire body that is positioned adjacent to the base end of the tapered portion 112 of the wire body, and when the first coating portion 121 is swollen, the base end of the coating tapered portion 121b may be positioned closer to the tip than the tip of the second constant outer diameter portion 113 of the wire body.

[0125] With this configuration, when the guide wire 100 is pushed into the constricted section, the base end of the lubricated tapered section 121b contacts the entrance to the constricted section before the tip of the second constant outer diameter section 113 of the wire body. As a result, the tip of the second constant outer diameter section 113 of the wire body does not get caught at the entrance to the constricted section, improving the ease of insertion into the constricted section.

[0126] Furthermore, the first coating portion 121 includes a second coating portion with a constant outer diameter 121c, which is positioned adjacent to the base end of the coating tapered portion 121b. In a state where the first coating portion 121 is swollen, the maximum value of the outer diameter r1 of the first coating portion with a constant outer diameter 121a may be smaller than the maximum value of the outer diameter r3 of the second coating portion with a constant outer diameter 121c.

[0127] This configuration allows the outer diameter of the tip of the guide wire 100 to be reduced, further improving its ability to pass through constricted areas.

[0128] Furthermore, the lubricating coating layer 120E of the guide wire 100E includes a second coating portion 122E that forms the tip of the guide wire 100E. The second coating portion 122E is made of a material that can swell when wet, and when the first coating portion 121E and the second coating portion 122E are swollen, the thickness d3 of the second coating portion 122E in the longitudinal direction may be greater than the radial thickness d2 of the first constant outer diameter coating portion 121Ea of the first coating portion 121E.

[0129] With this configuration, the guidewire 100E can have high elasticity and high lubricity at its tip due to the lubricating coating layer 120E. In addition, the surgeon can intuitively sense when the tip of the guidewire 100E has come into contact with the blood vessel wall or the entrance to the stenosis thanks to the second coating portion 122E, allowing the surgeon to carefully advance the guidewire 100E. Therefore, as the guidewire 100E progresses through the blood vessel toward the stenosis, vascular perforation can be suppressed, and its maneuverability at curved and bifurcated sections of the blood vessel is improved.

[0130] Furthermore, the lubricating coating layer 120F of the guide wire 100F includes a second coating portion 122F that forms the tip of the guide wire 100F, and the second coating portion 122F may be formed of a hydrophobic polymer.

[0131] With this configuration, the lubrication at the tip of the guide wire 100F is moderately suppressed, allowing it to reliably grasp the entrance to the constricted area.

[0132] Furthermore, when the first coating portion 121 of the guide wire 100 is swollen, the minimum value of the radial thickness d1 of the coating tapered portion 121b in the wire body tapered portion 112 may be greater than or equal to the minimum value of the radial thickness d2 of the coating first constant outer diameter portion 121a.

[0133] With this configuration, the guide wire 100 has high lubricity in the coated tapered portion 121b, further improving its ability to pass through constricted areas.

[0134] Furthermore, the wire body 110 of the guide wire 100 includes a long core member 10A and a coil (tubular body 20A) arranged to cover the outer circumference of the tip of the core member 10A, and at least the first constant outer diameter portion 111 of the wire body and the tapered portion 112 of the wire body may be formed by the coil.

[0135] With this configuration, the guidewire 100 has improved flexibility at its tip due to the coil, thus improving maneuverability in curved and bifurcated sections when advancing through blood vessels. In addition, because the tip of the tapered portion 121b of the first covering portion 121 of the guidewire 100 is located further forward than the tip of the tapered portion 112 of the wire body, the coil forming the tapered portion 112 of the wire body is prevented from getting caught in narrowed sections, thus preventing damage to the coil.

[0136] Furthermore, the wire body 110 of the guide wire 100 includes a long core member 10B and a resin layer 20B that covers the outer circumference of the core member 10B, and at least the outer circumference of the first constant outer diameter portion 111 of the wire body and the outer circumference of the tapered portion 112 of the wire body may be formed by the resin layer 20B.

[0137] With this configuration, the lubricating coating layer 120 of the guide wire 100 is coated on the resin layer 20B, thereby improving its peel resistance. [Explanation of symbols]

[0138] 100, 100A, 100B, 100C, 100D, 100E, 100F guide wires, 110, 110A, 110B wire body, 111 Wire body first constant outer diameter section, 112 Wire body tapered section, 113 Wire body second constant outer diameter section, 120 Lubricating coating layer, 121, 121C, 121D, 121E, 121F First covering portion, 121a, 121Ca, 121Da, 121Ea, 121Fa Covered first constant outer diameter section, 121b, 121Cb, 121Db, 121Eb, 121Fb Covered tapered section, 121c, 121Cc, 121Dc, 121Ec, 121Fc Covering second constant outer diameter section, 122, 122C, 122E, 122F Second coating section, C center axis, d1 The radial thickness of the tapered portion of the covering in the tapered portion of the wire body, d2 Radial thickness of the coating in the first constant outer diameter portion of the wire body, d3 Thickness in the longitudinal direction of the second covering portion, r1 Outer diameter of the first fixed outer diameter section of the coating, r2 Outer diameter of the coated tapered section, r3: Outer diameter of the second fixed outer diameter section of the coating.

Claims

1. A guide wire having a long wire body and a lubricating coating layer covering at least a portion of the wire body, The wire body includes a first constant outer diameter portion of the wire body and a tapered portion of the wire body adjacent to the base end of the first constant outer diameter portion of the wire body. The lubricating coating layer includes a first coating portion formed of a material that can swell when wet, The first covering portion includes a first covering portion with a constant outer diameter and a covering tapered portion positioned adjacent to the base end of the first covering portion with a constant outer diameter. A guide wire in which, when the first coating portion is swollen, the tip of the coating tapered portion is located closer to the tip than the tip of the wire body tapered portion.

2. The wire body includes a second constant outer diameter portion of the wire body, which is positioned adjacent to the base end of the tapered portion of the wire body. The guide wire according to claim 1, wherein, in the state in which the first coating portion is swollen, the base end of the coating tapered portion is located on the tip side of the tip of the second constant outer diameter portion of the wire body.

3. The first covering portion includes a second covering portion with a constant outer diameter, which is positioned adjacent to the base end of the covering tapered portion. The guide wire according to claim 1, wherein, in a state in which the first coating portion is swollen, the maximum value of the outer diameter of the first constant outer diameter coating portion is smaller than the maximum value of the outer diameter of the second constant outer diameter coating portion.

4. The lubricating coating layer includes a second coating portion that forms the tip of the guide wire. The second coating portion is formed of the material that can swell when wet, The guide wire according to any one of claims 1 to 3, wherein, in a state in which the first and second coating portions are swollen, the thickness of the second coating portion in the longitudinal direction is greater than the thickness of the first coating portion in the radial direction of the first coating portion with a constant outer diameter.

5. The lubricating coating layer includes a second coating portion that forms the tip of the guide wire. The guide wire according to any one of claims 1 to 3, wherein the second coating portion is formed of a hydrophobic polymer.

6. The guide wire according to any one of claims 1 to 3, wherein, in a state in which the first coating portion is swollen, the minimum value of the radial thickness of the coating tapered portion in the wire body tapered portion is greater than or equal to the minimum value of the radial thickness of the first constant outer diameter coating portion.

7. The wire body includes a long core member and a coil arranged to cover the outer circumference of the tip of the core member. The guide wire according to any one of claims 1 to 3, wherein at least the first constant outer diameter portion of the wire body and the tapered portion of the wire body are formed by a coil.

8. The wire body includes a long core member and a resin layer covering the outer circumference of the core member. The guide wire according to any one of claims 1 to 3, wherein at least the outer circumference of the first constant outer diameter portion of the wire body and the outer circumference of the tapered portion of the wire body are formed of a resin layer.

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