WO2024171959A1

WO2024171959A1 - Guide wire

Info

Publication number: WO2024171959A1
Application number: PCT/JP2024/004491
Authority: WO
Inventors: 健太三觜; 彩加吉本; 恵勝本
Original assignee: テルモ株式会社
Priority date: 2023-02-13
Filing date: 2024-02-09
Publication date: 2024-08-22

Abstract

[Problem] To suppress the occurrence of perforation of a blood vessel when advancing within the blood vessel. [Solution] A guide wire having a long wire body 110 and a lubricating coating layer 120 covering at least part of the wire body 110. The lubricating coating layer 120 is formed from a material capable of swelling when wet and has a first coating section 121 covering the leading end of the wire body 110 and a predetermined area in a leading end section 111 of the wire body 110. The first coating section 121 has an outer circumferential surface including a curved surface that is formed by a change in the thickness of the first coating section 121 and is a protrusion on the radially outward side of the wire body 110.

Description

Guidewires

The present invention relates to a guidewire.

A guidewire is a medical device used to guide various catheters to lesions that occur within blood vessels to treat the lesions (see, for example, Patent Document 1).

The surgeon inserts a guidewire into the blood vessel, brings the tip of the guidewire close to the lesion, and then inserts a catheter along the guidewire. The guidewire must travel around the curves and branches of the blood vessel and pass through the stenosis. For this reason, the guidewire must have a flexible tip and be able to be inserted easily into the stenosis.

JP 2016-221249 A

When a guidewire advances through a blood vessel, its tip may come into contact with the vessel wall. If the guidewire is pushed in with more force than necessary, it may break through the vessel wall and cause blood vessel perforation.

At least one embodiment of the present invention has been made in consideration of the above circumstances, and aims to provide a guidewire that can suppress the occurrence of vascular perforation when advancing through a blood vessel.

The above object of the present invention can be achieved by any one of the following (1) to (6).

(1) A guidewire having a long wire body and a lubricating coating layer covering at least a portion of the wire body, the lubricating coating layer being formed of a material that swells when wet, the lubricating coating layer having a first coating portion covering the tip of the wire body and a predetermined area of the tip of the wire body, the first coating portion being formed by changing the thickness of the first coating portion, and having an outer peripheral surface including a curved surface that is convex radially outward of the wire body.

(2) The first covering portion has a first region that is a region from a tip to a portion having a maximum outer diameter and that has a thickness increasing from the tip to the base end, and a second region that is a region from a base end of the first region to a base end of the first covering portion and that at least partially includes a portion that has a thickness decreasing from the tip to the base end,
The guidewire according to (1) above, wherein the second region has a second region distal end portion that is convex radially outward and a second region proximal end portion that is convex radially inward.

(3) The guide wire of (1) or (2) above, wherein the lubricating coating layer includes a second coating portion that is continuous with the base end of the first coating portion and covers the wire body, and the outer circumferential surfaces of the first coating portion and the second coating portion are smoothly connected.

(4) The guidewire of (3) above, in which, when the lubricating coating layer is in a swollen state, the radial thickness of the first coating portion is equal to or greater than the radial thickness of the second coating portion.

(5) A guidewire according to (3) or (4) above, in which, when the lubricating coating layer is in a swollen state, the maximum outer diameter of the first coating portion is greater than the maximum outer diameter of the second coating portion.

(6) A guidewire according to (3) or (4) above, in which, when the lubricating coating layer is in a swollen state, the maximum outer diameter of the first coating portion is equal to or smaller than the maximum outer diameter of the second coating portion.

According to one embodiment of the present invention, the guidewire has a first coating portion composed of a lubricating coating layer disposed at the tip of the wire body. The first coating portion is formed by varying the thickness of the first coating portion, and has an outer peripheral surface that includes a curved surface that is convex radially outward from the wire body. Therefore, the first coating portion can mitigate the impact when the guidewire comes into contact with the blood vessel wall. In addition, the first coating portion can notify the surgeon by touch that the guidewire has come into contact with the blood vessel wall, allowing the surgeon to carefully manipulate the guidewire. Therefore, the guidewire can suppress blood vessel perforation.

2 is a partially enlarged view of the vicinity of the distal end of the guide wire according to the present invention. FIG. 1 is a schematic cross-sectional view of a first embodiment of a guidewire according to the present invention; FIG. 2 is a schematic cross-sectional view of a second embodiment of the guidewire according to the present invention. FIG. 4 is a diagram for explaining the shape of a first coating portion of the lubricant coating layer. 13 is a partially enlarged view of the vicinity of the distal end of the guide wire of the first modified example. FIG. FIG. 11 is a partially enlarged view of the vicinity of the distal end of a guide wire according to a second modification. FIG. 13 is a partially enlarged view of the vicinity of the distal end of a guide wire according to modification 3. FIG. 13 is a partially enlarged view of the vicinity of the distal end of a guide wire according to modification 4. FIG. 13 is a partially enlarged view of the vicinity of the tip portion of the guide wire of modified example 5. FIG. 23 is a partially enlarged view of the vicinity of the tip portion of the guide wire of modified example 6. FIG. 23 is a partially enlarged view of the vicinity of the tip portion of the guide wire of modified example 7.

Below, the form for carrying out the present invention will be described in detail with reference to the drawings. The embodiment shown here is an example to embody the technical idea of the present invention, and does not limit the present invention. Furthermore, all other possible forms, examples, and operating techniques that can be thought of 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 included in the scope of the invention described in the claims and their equivalents.

Furthermore, for the convenience of illustration and ease of understanding, the drawings attached to this specification may be depicted diagrammatically with appropriate changes in scale, aspect ratio, shape, etc. from the actual product, but these are merely examples and do not limit the interpretation of the present invention.

For ease of explanation, the following directions are defined in this specification. In FIG. 1, the "longitudinal direction" is the longitudinal direction of the guidewire 100, which is the direction along the central axis C of the guidewire 100. The "radial direction" is the direction moving away from or approaching the central axis C of the guidewire 100 in an orthogonal cross section (transverse cross section) with the central axis C of the guidewire 100 as the reference axis. The "circumferential direction" is the rotational direction with the central axis C of the guidewire 100 as the reference axis.

The side of the guidewire 100 that is inserted into the blood vessel is referred to as the "tip side," and the side opposite the tip side (the side that is held by the surgeon) is referred to as the "base side." The part that includes a certain range from the tip (the most distal end) along the longitudinal direction is referred to as the "tip portion," and the part that includes a certain range from the base end (the most proximal end) in the longitudinal direction is referred to as the "base end."

In the following explanation, when ordinal numbers such as "first" and "second" are used, they are used for convenience and do not dictate any particular order, unless otherwise specified.

The guidewire 100 according to the present invention is a medical device that is inserted into blood vessels to guide catheters or stents for intravascular treatment to lesions. Note that the guidewire 100 can also be inserted into other biological lumens (such as blood vessels, ureters, bile ducts, fallopian tubes, and hepatic ducts) other than blood vessels depending on the purpose of treatment.

As shown in FIG. 1, the guidewire 100 has a long wire body 110 and a lubricating coating layer 120 that covers at least a portion of the wire body 110.

<Wire body>
The wire body 110 constitutes the main body of the guide wire 100, and has a lubricious coating layer 120 formed on at least a portion of the outer circumferential surface.

The wire body 110 may have any known configuration, such as a coil-type first configuration (guidewire 100A) in which a coil (tubular body 20A) is provided on a core member 10 as shown in FIG. 2, or a jacket-type second configuration (guidewire 100B) in which the entire core member 10 is covered with a resin layer 20B as shown in FIG. 3. The configurations of guidewires 100A and 100B will be described below as examples of the configuration of the guidewire 100 of the present invention.

<First Form>
The configuration of a first embodiment of the guidewire 100 according to the present invention will be described with reference to FIG.

As shown in Figure 2, the guidewire 100A has a long core member 10A, a tubular body 20A that covers the periphery of the tip of the core member 10A, a fixing portion 30A that fixes the tubular body 20A to the core member 10A, and a coating layer 40A that covers each member including the core member 10A. The core member 10A, the tubular body 20A, and the fixing portion 30A constitute the wire body 110A of the guidewire 100A.

The core member 10A comprises a first core portion 11A and a second core portion 12A disposed on the base end side of the first core portion 11A and joined to the first core portion 11. The first core portion 11A is a long member extending from the tip of the second core portion 12A along the longitudinal direction toward the tip side of the guidewire 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 guidewire 100A. The first core portion 11A and the second core portion 12A can be joined by welding, brazing, or soldering.

The core member 10A can be formed from known materials applicable to guidewires, such as superelastic alloys such as nickel-titanium alloys and stainless steel. It is preferable that the first core portion 11A is formed from a material with lower rigidity than the material of the second core portion 12A, but the first core portion 11A and the second core portion 12A may be formed from the same material. Furthermore, the core member 10A may be formed from a single continuous member, rather than being formed from multiple members like the first core portion 11A and the second core portion 12A.

The tubular body 20A is a coil formed by winding a wire in a spiral shape around the core member 10A. The tubular body 20A is formed of a first coil 21A arranged at the tip of the first core portion 11A, and a second coil 22A arranged at the base end side of the first coil 21A and arranged coaxially 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. It is preferable that the outer diameters of the first coil 21A and the second coil 22A are constant from the tip to the base end. The tubular body 20A may be formed of one coil, or three or more coils.

The outer diameter of the wire material forming the first coil 21A is larger than the outer diameter of the wire material forming the second coil 22A. The cross-sectional shape of the wire material forming the first coil 21A and the second coil 22A is preferably circular, but may also be elliptical or polygonal. In addition, the wire material forming the first coil 21A and the second coil 22A may be a twisted wire consisting of two or more wire materials, rather than just a single wire material.

The wire that forms 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, metals such as gold, platinum, and tungsten, or alloys containing these metals.

The wire diameter of the wire of the first coil 21A and the second coil 22A constituting the luminal body 20A is 0.02 mm or more and 0.2 mm or less. However, the material of the wire forming the first coil 21A and the second coil 22A of the luminal body 20A, the outer diameter, the cross-sectional shape, the pitch of the first coil 21A and the second coil 22A, etc. can be appropriately selected depending on the purpose of the guidewire 100A.

The fixing part 30A is a member for fixing the tubular body 20A to the core member 10A. The fixing part 30A has a tip fixing part 31A that fixes the tip of the tubular body 20A to the core member 10A, an intermediate fixing part 32A that fixes the intermediate part of the tubular body 20A to the core member 10A, and a base end fixing part 33A that fixes the base end of the tubular body 20A to the core member 10A.

The material forming the fixing portion 30A is a brazing material or solder. The brazing material may be gold brazing or silver brazing. The solder may be tin-silver alloy solder or tin-lead alloy solder. The material forming the fixing portion 30A may be an adhesive.

The coating layer 40A includes a lubricating coating layer 41A and a base-end coating layer 42A formed on the base-end 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 guidewire 100A by reducing friction between the guidewire 100A and a blood vessel or catheter.

The lubricating coating layer 41A covers each part (the tubular body 20A, the fixing part 30A) provided on the first core part 11A and a part of the first core part 11A. The base-side coating layer 42A covers the part of the core member 10A located on the base-side side of the tubular body 20A.

The lubricating coating layer 41A can be formed of 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 copolymers), water-soluble nylon, polyvinyl alcohol, polyvinylpyrrolidone, and derivatives thereof. In particular, the lubricating coating layer 41A is preferably formed of a material that swells when wet to become a hydrogel. Hydrogels have appropriate elasticity and can mitigate the impact when the guidewire 100A comes into contact with the blood vessel wall.

The base end coating layer 42 can be made of a low friction material. Fluorine-based resins (PTFE, ETFE, etc.) and silicone resins can be suitably used as low friction materials.

<Second Form>
Next, a configuration of a second embodiment of the guidewire 100 according to the present invention will be described with reference to FIG.

As shown in FIG. 3, the guidewire 100B has a core member 10B extending in the longitudinal direction, a resin layer 20B that coats the core member 10B, and a lubricating coating layer 30B that coats the outer circumferential surface of the resin layer 20B. The core member 10B and the resin layer 20B constitute the wire body 110B of the guidewire 100B.

The core member 10B includes a first core portion 11B having at least a portion of a tapered shape in which the outer diameter gradually increases from the tip to the base end, and a second core portion 12B that is connected to the base end of the first core portion 11B and has a constant outer diameter along the longitudinal direction.

The core member 10B can be made of a material that can be used for the aforementioned core member 10A.

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

The resin layer 20B is preferably formed from a highly flexible material, such as polyolefins such as polyethylene and polypropylene, polyvinyl chloride, polyesters (PET, PBT, etc.), polyamides, polyimides, polyurethanes, polystyrene, polycarbonates, silicone resins, fluorine-based resins (PTFE, ETFE, PFA, etc.), composite materials of these, various rubber materials such as latex rubber and silicone rubber, or composite materials combining two or more of these.

The thickness of the resin layer 20B is not particularly limited. Furthermore, the resin layer 20B is not limited to a single-layer structure, and may be a multi-layer structure. The resin layer 20B may cover only the tip portion of the guidewire 100B.

The lubricating coating layer 30B is formed to cover the resin layer 20B, and improves the operability and safety of the guidewire 100B by reducing friction between the guidewire 100B and the blood vessel or catheter.

The lubricating coating layer 30B can be formed from a material that can be used for the lubricating coating layer 41A described above.

The guidewire 100B can be provided with a marker portion at the tip of the first core portion 11. The marker portion is provided by fixing a coil or a cylindrical body made of a radiopaque material near 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 guidewire 100B has improved visibility under radioscopy.

The guidewire 100 according to the present invention has a characteristic shape for the lubricating coating layer 120 in order to suppress blood vessel perforation. The lubricating coating layer 120 according to the present invention will be described below.

<Lubricant Coating Layer>
The lubricous coating layer 120 includes a first coating portion 121 and a second coating portion 122. The lubricous coating layer 120 corresponds to the lubricous coating layer 41A of the guidewire 100A and the lubricous coating layer 30B of the guidewire 100B. At least a portion of the lubricous coating layer 120 is formed from a material that can swell when wet.

<First covering part>
1 , the first coating portion 121 is a portion of the lubricant coating layer 120 that covers the tip of the wire body 110 and a predetermined region of the tip portion 111 of the wire body 110. The first coating portion 121 has an outer circumferential surface that includes a curved surface that is convex radially outward from the wire body 110 and is formed by changing the thickness of the lubricant coating layer 120.

As shown in FIG. 4, the first coating portion 121 has a first region R1 from the tip to the portion with the maximum outer diameter, and a second region R2 from the base end of the first region R1 to the base end of the first coating portion 121. In the guidewire 100, the thickness of the first coating portion 121 increases from the tip to the base end in the first region R1. The thickness of the first coating portion 121 decreases from the tip to the base end in the second region R2. In this specification, the thickness of the lubricous coating layer 120 is the thickness when the material forming the lubricous coating layer 120 is in a swollen state when wet.

Figure 4 is a diagram showing a two-axis Cartesian coordinate system in which the axis passing through the central axis C of the wire body 110 is the x-axis (longitudinal direction of the guidewire 100) and the axis perpendicular to the x-axis and tangent to the tip of the first covering portion 121 is the y-axis (radial direction of the guidewire 100), with the central axis C of the guidewire 100 placed in a natural state overlapping with the x-axis. The first covering portion 121 has a teardrop-shaped three-dimensional shape obtained by rotating the curve L made by the outer circumferential surface of the first covering portion 121 shown in the first quadrant of the Cartesian coordinate system shown in Figure 4, around the x-axis (central axis C) as the axis of rotation.

As shown in FIG. 4, in the first quadrant of the Cartesian coordinate system, when the function y=f(x) represents the curve L formed by the outer circumferential surface of the first covering portion 121 when the guidewire 100 is viewed from the side, the function y=f(x) has a second derivative f"(x) in a certain section of x (x>0). The first region R1 of the first covering portion 121 corresponds to the section of x that satisfies f'(x)>0 on the distal side of the maximum point P1 (first derivative f'(x)=0) on the curve L where the function y=f(x) is maximum and largest in FIG. 4. The second region R2 of the first covering portion 121 corresponds to the section of x that satisfies f'(x)<0 on the proximal side of the maximum point P1 on the curve L in FIG. 4.

The first region R1 of the first covering portion 121 is convex radially outward. That is, in FIG. 4, the section corresponding to the first region R1 of the first covering portion 121 is a section in which the function y = f(x) satisfies f''(x) < 0 and f''(x) < 0.

The second region R2 of the first covering portion 121 has a second region tip portion R21 which is a predetermined range from the base end of the first region R1 to the tip side of the second region R2 and is convex radially outward, and a second region base end portion R22 which is proximal to the second region tip portion R21 and is convex radially inward. The second region R2 of the first covering portion 121 has an inflection point P2 on the curve L in FIG. 4 where f"(x)=0 and the sign of f"(x) is inverted and the concavity and convexity of the curve L changes. The second region tip portion R21 corresponds to the section where f'(x)<0 and f"(x)<0 where the function y=f(x) is convex upward, with the inflection point P2 on the curve L in FIG. 4 as the boundary, and the second region base end portion R22 corresponds to the section where f'(x)<0 and f"(x)>0 where the function y=f(x) is convex downward. In FIG. 4, "upward convex" means that a line segment connecting any two points on the curve L is always below the curve. On the other hand, "downward convex" means that a line segment connecting any two points on the curve is always above the curve.

The lubricating coating layer 120 smoothly connects the outer surface of the first coating portion 121 and the outer surface of the second coating portion 122 via the second region base end R22 located at the connection between the first coating portion 121 and the second coating portion 122. As a result, the guidewire 100 is less likely to have the connection between the first coating portion 121 and the second coating portion 122 of the lubricating coating layer 120 get caught on the blood vessel wall or the inner cavity of the catheter, preventing peeling of the lubricating coating layer 120.

The first covering portion 121 has an outer peripheral surface including a curved surface that is convex radially outward of the wire body 110, formed by varying the thickness of a material that swells when wet, and covers the tip of the wire body 110 and a predetermined area of the tip portion 111 of the wire body 110. This allows the first covering portion 121 to mitigate the impact when the guidewire 100 comes into contact with the blood vessel wall. In addition, the first covering portion 121 can notify the surgeon by touch that the guidewire 100 has come into contact with the blood vessel wall, allowing the surgeon to carefully manipulate the guidewire 100. Therefore, the guidewire 100 can suppress blood vessel perforation.

The first covering portion 121 has a length in the longitudinal direction of 0.4 mm or more. In the case of a coil type in which a wire is wound around the core member 10 of the wire body 110 as shown in FIG. 2, the first covering portion 121 is formed across multiple wires at least in the longitudinal direction.

The radial thickness t1 of the first covering portion 121 is 0.05 mm or more and 0.2 mm or less.

From the viewpoint of preventing blood vessel perforation, the first covering portion 121 should be formed within a range of 5 mm from the tip of the guidewire 100, preferably within a range of 1 mm to 2 mm from the tip of the guidewire 100.

The first covering portion 121 may have a shape that does not have an inflection point P2 on the curve formed by the outer peripheral surface. The first covering portion 121 covers the tip of the wire body 110 and a specified region of the tip portion 111 of the wire body 110, and can have a shape that has an outer peripheral surface that is only a convex curved surface on the radially outward side of the wire body 110. In this case, the first covering portion 121 has the first region R1 and the second region tip portion R21 of the second region R2.

<Second covering part>
1, the second coating portion 122 is a portion of the lubricant coating layer 120 that is closer to the base end than the first coating portion 121. The second coating portion 122 is formed to a substantially constant thickness. The outer circumferential surface of the second coating portion 122 is smoothly connected to the outer circumferential surface of the first coating portion 121.

As shown in FIG. 1, when the lubricating coating layer 120 is in a swollen state, the radial thickness t1 of the first coating portion 121 is equal to or greater than the radial thickness t2 of the second coating portion 122 (t1≧t2). Furthermore, the maximum outer diameter d1 of the first coating portion 121 is greater than the maximum outer diameter d2 of the second coating portion 122 (d1>d2). This improves the guidewire 100's ability to absorb shock when the tip portion 111 comes into contact with the blood vessel wall and to transmit tactile sensation to the surgeon.

The lubricant coating layer 120 may be composed of only the first coating portion 121. The lubricant coating layer 120 may also have other coating portions in addition to the first coating portion 121 and the second coating portion 122.

The first coating portion 121 of the lubricating coating layer 120 is formed of a material that can swell when wet. The first coating portion 121 can be formed of a material that can be applied to the lubricating coating layer 41A in the first embodiment described above. The second coating portion 122 of the lubricating coating layer 120 is preferably formed of the same material as the first coating portion 121. Note that the first coating portion 121 and the second coating portion 122 may each be formed of a different material.

The lubricating coating layer 120 can be formed by immersing the wire body 110 from the tip side into a solution containing a material for forming the lubricating coating layer 120 for the length required for coating, and then vertically pulling the wire body 110 out of the solution and then carrying out a drying process. The wire body 110 may be immersed in the solution once or multiple times.

When the wire body 110 is pulled out of the solution, a portion of the solution adhering to the outer peripheral surface of the wire body 110 forms a teardrop-shaped liquid puddle that covers the entire circumference of the tip 111 of the wire body 110 due to the action of surface tension. The first coating portion 121 can be formed by drying the liquid puddle that has formed at the tip 111 of the wire body 110. When the wire body 110 is pulled out of the solution, the solution adhering to the outer peripheral surface of the wire body 110 flows downward due to gravity, and the second coating portion 122 can be formed as a layer with a substantially constant thickness.

[Modification example]
The guidewire 100 of the present invention can be modified as appropriate as in the following modified examples. In the following description of each modified example, differences from the above-described embodiment will be mainly described, and components having the same functions as those in other embodiments will be denoted by the same or related reference numerals, detailed description will be omitted, and no particular mention will be made. The configuration, members, method of use, etc. may be the same as those in each embodiment. Furthermore, each modified example can be implemented in combination with other embodiments by appropriately selecting necessary configurations from those shown in each modified example, within the scope of the gist of the present invention.

The guidewires shown in Modifications 1 to 7 are characterized by the shape of the tip of the wire body. Therefore, the wire body in each form may be configured as either the coil-type wire body 110A shown in the first form (see Figure 2) or the jacket-type wire body 110B shown in the second form (see Figure 3), as in the forms described above.

<Variation 1>
5 is an enlarged view of the distal end portion and its periphery of a guidewire 100C of Modification 1. The dotted line in the figure indicates the outer shape of a wire body 110C.

As shown in FIG. 5, the guidewire 100C of the first modified example is characterized by the shape of the tip of the wire body 110C. The tip portion 111C of the wire body 110C includes, in order from the base end to the tip of the wire body 110C, a constant outer diameter portion 112C, a tapered portion 113C disposed adjacent to the tip of the constant outer diameter portion 112C, and a most distal portion 114C disposed adjacent to the tip of the tapered portion 113C.

Tapered portion 113C has a generally truncated cone shape with a tapered surface whose outer diameter gradually decreases toward the tip. The most distal end portion 114C is provided at the tip of tapered portion 113C and has a generally indented spherical shape whose outer diameter gradually decreases toward the tip.

The guidewire 100C has a lubricant coating layer 120 that covers at least a portion of the wire body 110C. As shown in FIG. 5, the lubricant coating layer 120 has an outer peripheral surface that includes a curved surface that is convex radially outward, and includes a first coating portion 121 that covers the tip of the wire body 110C and a predetermined area of the tip portion 111C of the wire body 110C, and a second coating portion 122 that is disposed on the base end side of the first coating portion 121, has a substantially constant thickness, and is smoothly connected to the outer peripheral surface of the first coating portion 121.

As shown in FIG. 5, when the lubricating coating layer 120 is in a swollen state, the maximum outer diameter d1 of the first coating portion 121 is larger than the maximum outer diameter d2 of the second coating portion 122. The radial thickness t1 of the first coating portion 121 is equal to or larger than the radial thickness t2 of the second coating portion 122.

In the guidewire 100C of the first modification, the tip portion 111C, including the portion with a reduced diameter, is covered with the first coating portion 121 of the lubricous coating layer 120, so that blood vessel perforation can be prevented and peeling of the lubricous coating layer 120 can be prevented.

<Modification 2>
6 is an enlarged view of the distal end portion and its periphery of a guidewire 100D according to Modification 2. The dotted line in the drawing indicates the outer shape of a wire body 110D.

As shown in FIG. 6, the guidewire 100D of the second modified example is characterized by the shape of the tip of the wire body 110D. The tip portion 111D of the wire body 110D includes, in order from the base end to the tip of the wire body 110D, a constant outer diameter portion 112D and a tapered portion 113D disposed adjacent to the tip of the constant outer diameter portion 112D.

The tapered portion 113D has a generally conical shape with an outer diameter that gradually decreases toward the tip. The slope of the tapered portion 113D is greater than the slope of the tapered portion 113C of modified example 1. The length of the tapered portion 113D in the major axis direction is shorter than the length of the tapered portion 113C of modified example 1 and the most distal end portion 114C of modified example 1. The tip of the tapered portion 113D has a rounded shape.

The guidewire 100D has a lubricant coating layer 120 that covers at least a portion of the wire body 110D. As shown in FIG. 6, the lubricant coating layer 120 has an outer peripheral surface that includes a curved surface that is convex radially outward, and includes a first coating portion 121 that covers the tip of the wire body 110D and a predetermined area of the tip portion 111D of the wire body 110D, and a second coating portion 122 that is disposed on the base end side of the first coating portion 121, has a substantially constant thickness, and is smoothly connected to the outer peripheral surface of the first coating portion 121.

As shown in FIG. 6, when the lubricating coating layer 120 is in a swollen state, the maximum outer diameter d1 of the first coating portion 121 is larger than the maximum outer diameter d2 of the second coating portion 122. The radial thickness t1 of the first coating portion 121 is equal to or larger than the radial thickness t2 of the second coating portion 122.

In the guidewire 100D of the second modification, the tip portion 111D including the thinned portion is covered with the first coating portion 121 of the lubricous coating layer 120, so that blood vessel perforation can be prevented and peeling of the lubricous coating layer 120 can be prevented.

<Modification 3>
7 is an enlarged view of the distal end portion and its periphery of a guidewire 100E according to Modification 3. The dotted line in the figure indicates the outline of a wire body 110E.

As shown in Figure 7, the guidewire 100E of the third modified example is characterized by the shape of the tip of the wire body 110E. The tip portion 111E of the wire body 110E includes, in order from the base end to the tip of the wire body 110E, a constant outer diameter portion 112E, a tapered portion 113E disposed adjacent to the tip of the constant outer diameter portion 112E, and a most distal portion 114E disposed adjacent to the tip of the tapered portion 113E.

Tapered portion 113E has a generally truncated cone shape with a tapered surface whose outer diameter gradually decreases toward the tip. Most distal end portion 114E is provided at the tip of tapered portion 113E and has a generally hemispherical shape whose outer diameter gradually decreases toward the tip. The gradient of tapered portion 113E is greater than the gradient of tapered portion 113C of modified example 1. The length in the major axis direction of tapered portion 113E and most distal end portion 114E is shorter than the length in the major axis direction of tapered portion 113C and most distal end portion 114C of modified example 1.

The guidewire 100E has a lubricant coating layer 120 that covers at least a portion of the wire body 110E. As shown in FIG. 7, the lubricant coating layer 120 has an outer peripheral surface that includes a curved surface that is convex radially outward, and includes a first coating portion 121 that covers the tip of the wire body 110E and a predetermined area of the tip portion 111E of the wire body 110E, and a second coating portion 122 that is disposed on the base end side of the first coating portion 121, has a substantially constant thickness, and is smoothly connected to the outer peripheral surface of the first coating portion 121.

As shown in FIG. 7, when the lubricating coating layer 120 is in a swollen state, the maximum outer diameter d1 of the first coating portion 121 is larger than the maximum outer diameter d2 of the second coating portion 122. The radial thickness t1 of the first coating portion 121 is equal to or larger than the radial thickness t2 of the second coating portion 122.

In the guidewire 100E of the third modification, the tip portion 111E, including the portion with a reduced diameter, is covered with the first coating portion 121 of the lubricous coating layer 120, so that blood vessel perforation can be prevented and peeling of the lubricous coating layer 120 can be prevented.

<Modification 4>
8 is an enlarged view of the distal end portion and its periphery of a guidewire 100F according to Modification 4. The dotted line in the figure indicates the outer shape of a wire body 110F.

The guidewire 100F of the fourth modified example is characterized by the shape of the tip of the wire body 110F, as shown in Fig. 8. The tip portion 111F of the wire body 110F includes, in order from the base end to the tip of the wire body 110F, a first constant outer diameter portion 112F, a tapered portion 113F arranged adjacent to the tip of the first constant outer diameter portion 112F, a second constant outer diameter portion 114F arranged adjacent to the tip of the tapered portion 113F, and a most distal portion 115F arranged adjacent to the tip of the second constant outer diameter portion 114F.

The outer diameter of the second constant outer diameter portion 114F is smaller than the outer diameter of the first constant outer diameter portion 112F. The most distal end portion 115F has a generally hemispherical shape. The maximum outer diameter of the most distal end portion 115F is smaller than the outer diameter of the first constant outer diameter portion 112F and is equal to the outer diameter of the second constant outer diameter portion 114F.

The guidewire 100F has a lubricant coating layer 120 that covers at least a portion of the wire body 110F. As shown in FIG. 8, the lubricant coating layer 120 has an outer peripheral surface that includes a curved surface that is convex radially outward, and includes a first coating portion 121 that covers the tip of the wire body 110F and a predetermined area of the tip portion 111F of the wire body 110F, and a second coating portion 122 that is disposed on the base end side of the first coating portion 121, has a substantially constant thickness, and is smoothly connected to the outer peripheral surface of the first coating portion 121.

As shown in FIG. 8, when the lubricating coating layer 120 is in a swollen state, the maximum outer diameter d1 of the first coating portion 121 is larger than the maximum outer diameter d2 of the second coating portion 122. The radial thickness t1 of the first coating portion 121 is equal to or larger than the radial thickness t2 of the second coating portion 122.

In the guidewire 100F of the fourth modified example, the tip portion 111F, which includes a portion with a different outer diameter, is covered with the first coating portion 121 of the lubricous coating layer 120, so that blood vessel perforation can be suppressed and peeling of the lubricous coating layer 120 can be suppressed.

<Modification 5>
9 is an enlarged view of the distal end portion and its periphery of a guidewire 100G according to Modification 5. The dotted line in the figure indicates the outer shape of a wire body 110G.

As shown in FIG. 9, the guidewire 100G of the fifth modified example is characterized by the shape of the tip of the wire body 110G. The tip portion 111G of the wire body 110G includes, in order from the base end to the tip of the wire body 110G, a constant outer diameter portion 112G and a tapered portion 113G disposed adjacent to the tip of the constant outer diameter portion 112G.

The tapered portion 113G has a generally truncated cone shape with a tapered surface whose outer diameter gradually decreases toward the tip.

The guidewire 100G has a lubricant coating layer 120 that covers at least a portion of the wire body 110G. As shown in FIG. 9, the lubricant coating layer 120 has an outer peripheral surface that includes a curved surface that is convex radially outward, and includes a first coating portion 121 that covers the tip of the wire body 110G and a predetermined area of the tip portion 111G of the wire body 110G, and a second coating portion 122 that is disposed on the base end side of the first coating portion 121 and has a substantially constant thickness that is smoothly connected to the outer peripheral surface of the first coating portion 121.

As shown in FIG. 9, when the lubricating coating layer 120 is in a swollen state, the maximum outer diameter d1 of the first coating portion 121 is larger than the maximum outer diameter d2 of the second coating portion 122. The radial thickness t1 of the first coating portion 121 is equal to or larger than the radial thickness t2 of the second coating portion 122.

In the guidewire 100G of the fifth modified example, the tip portion 111G, including the portion with a reduced diameter, is covered with the first coating portion 121 of the lubricous coating layer 120, so that blood vessel perforation can be prevented and peeling of the lubricous coating layer 120 can be prevented.

<Modification 6>
10 is an enlarged view of the distal end portion and its periphery of a guidewire 100H according to Modification 6. The dotted line in the figure indicates the outer shape of a wire body 110H.

As shown in Fig. 10, the guidewire 100H of the sixth modified example is characterized by the shape of the tip of the wire body 110H. The tip portion 111H of the wire body 110H includes, in order from the base end to the tip of the wire body 110H, a first constant outer diameter portion 112H, a tapered portion 113H arranged adjacent to the tip of the first constant outer diameter portion 112H, and a second constant outer diameter portion 114H arranged adjacent to the tip of the tapered portion 113H.

The outer diameter of the second constant outer diameter portion 114H is smaller than the outer diameter of the first constant outer diameter portion 112H. The length in the major axis direction of the second constant outer diameter portion 114H is longer than the length in the major axis direction of the second constant outer diameter portion 114F of the fourth modified example. The tip of the second constant outer diameter portion 114H has a rounded shape.

The guidewire 100H has a lubricant coating layer 120 that covers at least a portion of the wire body 110H. The lubricant coating layer 120 includes a first coating portion 121 and a second coating portion 122.

As shown in FIG. 10, the first covering portion 121 has an outer peripheral surface that includes a curved surface that is convex radially outward, and covers the tip of the wire body 110H and a predetermined area of the tip portion 111H of the wire body 110H.

As shown in FIG. 10, the first coating portion 121 is a portion of the lubricating coating layer 120 that covers a predetermined region of the second constant outer diameter portion 114H of the wire body 110H. The first coating portion 121 has a first region R1 from the tip to the portion with the maximum outer diameter d1, and a second region R2 from the base end of the first region R1 to the base end of the first coating portion 121. The first region R1 of the first coating portion 121 is convex radially outward. The second region R2 of the first coating portion 121 has a second region tip portion R21 that is convex radially outward and is a predetermined range from the base end of the first region R1 to the tip side of the second region R2, and a second region base portion R22 that is convex radially inward and is on the base end side of the second region tip portion R21.

The first coating portion 121 has a constricted portion 123 at the portion where it connects with the second coating portion 122, where the outer peripheral surface of the lubricating coating layer 120 includes a curved surface that is convex radially inward. That is, the constricted portion 123 is formed at the base end portion R22 of the second region of the first coating portion 121. The constricted portion 123 smoothly connects the outer peripheral surface of the first coating portion 121 and the outer peripheral surface of the second coating portion 122.

As shown in FIG. 10, when the lubricating coating layer 120 is in a swollen state, the maximum outer diameter d1 of the first coating portion 121 is less than or equal to the maximum outer diameter d2 of the second coating portion 122. The radial thickness t1 of the first coating portion 121 is greater than or equal to the radial thickness t2 of the second coating portion 122. The first region R1 of the first coating portion 121 increases in thickness from the tip to the base end. The second region R2 of the first coating portion 121 decreases in thickness from the tip to the base end, and then increases in thickness through the constricted portion 123.

When the second region R2 of the first covered portion 121 is superimposed on a two-axis orthogonal coordinate system with the central axis C of the longitudinal section of the guidewire 100H coinciding with the x-axis, the second region R2 of the first covered portion 121 has an inflection point P2 on the curve L formed by the outer circumferential surface of the first covered portion 121 shown in the first quadrant, and a minimum point P3 (f'(x) = 0) at which the function y = f(x) is minimum, proximal to the inflection point P2. Therefore, the second region proximal end R22 of the guidewire 100H satisfies f'(x) < 0 and f''(x) < 0 on the distal side of the minimum point P3, and satisfies f'(x) > 0 and f''(x) < 0 on the proximal side of the minimum point P3. As a result, the second region proximal end R22 of the first covered portion 121 has a constricted portion 123.

As shown in FIG. 10, the second coating portion 122 is a portion of the lubricating coating layer 120 that is closer to the base end than the first coating portion 121. The second coating portion 122 is formed with a substantially constant thickness. The outer peripheral surface of the second coating portion 122 is smoothly connected to the outer peripheral surface of the first coating portion 121.

In the guidewire 100H of the sixth modified example, the tip portion 111H, including the narrowed portion, is covered with the first coating portion 121 of the lubricous coating layer 120, which prevents blood vessel perforation and prevents the lubricous coating layer 120 from peeling off. In addition, the guidewire 100H has a maximum outer diameter d1 of the first coating portion 121 that is equal to or smaller than the maximum outer diameter d2 of the second coating portion 122, which makes it easier to insert the guidewire into the stenosis.

<Modification 7>
11 is an enlarged view of the periphery of the distal end of a guidewire 100K of Modification 7. The dotted line in the figure indicates the outline of a wire main body 110K. The guidewire 100K of Modification 7 has a curved portion 112K at a distal end 111K. The curved portion 112K is provided closer to the proximal end than the first covering portion 121 of the guidewire 100K.

As shown in FIG. 11, the distal end 111K of the wire body 110K in the guidewire 100K of variant 7 includes, in order from the distal end to the proximal end of the wire body 110K, a distal straight section 113K, a curved section 112K, and a proximal straight section 114K. The outer diameter of the distal end of the curved section 112K matches the outer diameter of the proximal end of the distal straight section 113K. The outer diameter of the proximal end of the curved section 112K matches the outer diameter of the distal end of the proximal straight section 114K. The curved section 112K is formed in a range of 1 mm to 20 mm from the most distal end of the guidewire 100K.

The guidewire 100K has a lubricant coating layer 120 that covers at least a portion of the wire body 110K. The lubricant coating layer 120 includes a first coating portion 121 and a second coating portion 122.

As shown in FIG. 11, the first covering portion 121 has an outer peripheral surface including a curved surface that is convex radially outward, and covers the tip of the wire body 110K and a predetermined area of the tip straight portion 113K of the wire body 110K. The maximum outer diameter d1 of the first covering portion 121 is larger than the maximum outer diameter d2 of the second covering portion 122. The radial thickness t1 of the first covering portion 121 is equal to or greater than the radial thickness t2 of the second covering portion 122.

As shown in FIG. 11, the second coating portion 122 is a portion of the lubricating coating layer 120 that is closer to the base end than the first coating portion 121. The outer peripheral surface of the second coating portion 122 is smoothly connected to the outer peripheral surface of the first coating portion 121.

The guidewire 100K of variant 7 has a tip portion 111K covered with the first coating portion 121 of the lubricating coating layer 120, which prevents blood vessel perforation and prevents the lubricating coating layer 120 from peeling off.

[Action and Effect]
As described above, the guide wire 100 of the present invention has a long wire body 110 and a lubricant coating layer 120 covering at least a portion of the wire body 110, the lubricant coating layer 120 being formed of a material that swells when wet, and having a first coating portion 121 covering the tip of the wire body 110 and a predetermined region of the tip portion 111 of the wire body 110, and the first coating portion 121 is formed by changing the thickness of the first coating portion 121 and has an outer peripheral surface that includes a curved surface that is convex radially outward from the wire body 110.

With this configuration, the guidewire 100 has the first coating portion 121 of the lubricating coating layer 120 disposed at the tip of the wire body 110. The first coating portion 121 is formed by varying the thickness of the first coating portion 121, and has an outer peripheral surface that includes a curved surface that is convex radially outward from the wire body 110. Therefore, the first coating portion 121 can mitigate the impact when the guidewire 100 comes into contact with the blood vessel wall. In addition, the first coating portion 121 can notify the surgeon that the guidewire 100 has come into contact with the blood vessel wall by touch, allowing the surgeon to carefully manipulate the guidewire 100. Therefore, the guidewire 100 can suppress blood vessel perforation.

The first coated portion 121 of the guidewire 100 may have a first region R1 that is a region from the tip to the portion with the maximum outer diameter d1 and that increases in thickness from the tip to the base end, and a second region R2 that is a region from the base end of the first region R1 to the base end of the first coated portion 121 and that includes at least a portion where the thickness decreases from the tip to the base end, and the second region R2 may be configured to have a second region tip portion R21 that is convex radially outward and a second region base portion R22 that is convex radially inward.

The second region R2 of the first coating portion 121 has a shape that transitions from the tip to the base end from the second region tip portion R21, which is convex radially outward, to the second region base portion R22, which is convex radially inward. Therefore, the outer peripheral surface of the first coating portion 121 is smoothly connected to the outer peripheral surface located on the base end side of the second region R2 without creating a step. As a result, in the guidewire 100, the connection portion between the first coating portion 121 and the second coating portion 122 of the lubricous coating layer 120 is less likely to get caught on the blood vessel wall or the inner cavity of the catheter, so peeling of the lubricous coating layer 120 can be suppressed.

The lubricating coating layer 120 of the guidewire 100 may also include a second coating portion 122 that is continuous with the base end of the first coating portion 121 and covers the wire body 110, and the outer circumferential surfaces of the first coating portion 121 and the second coating portion 122 may be configured to be smoothly connected.

With this configuration, the guidewire 100 is coated with a lubricating coating layer 120 including a first coating portion 121 formed at the tip and a predetermined range of the tip of the wire body 110 and a second coating portion 122 formed on the base end side of the first coating portion 121, improving operability within a blood vessel. In addition, the guidewire 100 has a smooth connection between the outer circumferential surface of the first coating portion 121 and the outer circumferential surface of the second coating portion 122, which can prevent the lubricating coating layer 120 from peeling off due to the connection portion between the first coating portion 121 and the second coating portion 122 getting caught on the blood vessel wall or the inner cavity of the catheter.

Furthermore, when the lubricating coating layer 120 of the guidewire 100 is in a swollen state, the radial thickness of the first coating portion 121 may be greater than or equal to the radial thickness of the second coating portion 122, and the maximum outer diameter d1 of the first coating portion 121 may be greater than the maximum outer diameter d2 of the second coating portion 122.

With this configuration, the guidewire 100 has a thick first covering portion 121 formed on the tip portion 111 of the wire body 110, which improves the effect of mitigating the impact when the tip portion 111 comes into contact with the blood vessel wall and the effect of transmitting the tactile sensation to the surgeon.

In addition, when the lubricating coating layer 120 of the guidewire 100 is in a swollen state, the maximum outer diameter d1 of the first coating portion 121 may be equal to or smaller than the maximum outer diameter d2 of the second coating portion 122.

With this configuration, the guidewire 100 has the tip 111, including the narrowed portion, covered with the first coating portion 121 of the lubricous coating layer 120, which prevents blood vessel perforation and prevents the lubricous coating layer 120 from peeling off. In addition, the guidewire 100 has an outer diameter of the first coating portion 121 that is equal to or smaller than the outer diameter of the second coating portion 122, which makes it easier to insert the guidewire 100 into a stenotic portion.

This application is based on Japanese Patent Application No. 2023-019779, filed on February 13, 2023, the disclosure of which is incorporated by reference in its entirety.

100, 100A to 100K Guide wire,
110, 110A to 110K Wire body,
120 Lubricant coating layer,
121 first covering portion,
122 second covering portion,
C central axis,
d1 maximum outer diameter of the first covering part,
d2 maximum outer diameter of the second covering part,
R1 first region,
R2 second region,
R21 second region tip,
R22 second region proximal end;
t1: radial thickness of the first covering portion;
t2: Radial thickness of the second covering portion.

Claims

A guidewire having a long wire body and a lubricating coating layer covering at least a portion of the wire body,
the lubricating coating layer is made of a material that swells when wet, and has a first coating portion that covers the tip of the wire body and a predetermined area of the tip of the wire body;
The first covering-portion is formed by varying the thickness of the first covering-portion, and has an outer peripheral surface that includes a curved surface that is convex radially outward from the wire body.
the first covering portion has a first region which is a region from a tip to a portion having a maximum outer diameter and which has a thickness increasing from the tip to the base end, and a second region which is a region from the base end of the first region to the base end of the first covering portion and which at least partially includes a portion whose thickness decreases from the tip to the base end,
The guidewire according to claim 1 , wherein the second region has a second region distal end portion that is convex radially outward and a second region proximal end portion that is convex radially inward.
The guidewire of claim 1, wherein the lubricating coating layer includes a second coating portion that is continuous with the base end of the first coating portion and covers the wire body, and the outer circumferential surfaces of the first coating portion and the second coating portion are smoothly connected.
The guidewire of claim 3, wherein when the lubricating coating layer is in a swollen state, the radial thickness of the first coating portion is equal to or greater than the radial thickness of the second coating portion.
The guidewire of claim 3, wherein when the lubricating coating layer is in a swollen state, the maximum outer diameter of the first coating portion is greater than the maximum outer diameter of the second coating portion.
The guidewire of claim 3, wherein when the lubricating coating layer is in a swollen state, the maximum outer diameter of the first coating portion is equal to or smaller than the maximum outer diameter of the second coating portion.