Guide wire

Abstract

[Problem] To prevent vascular damage from occurring when a guide wire advances within a blood vessel. [Solution] A guide wire 100 comprises: an elongate wire body 110; and a lubricating coating layer 120 formed from a material capable of swelling upon wetting and covering at least a portion of the wire body 110. The wire body 110 includes: a core member 10; a tubular member 20 disposed so as to cover the outer periphery of a tip end portion of the core member 10; and a retaining part 40 that retains a portion of the inner peripheral surface between the tip end and the base end of the tubular member 20. The lubricating coating layer 120 has, on a portion of the outer peripheral surface thereof at the position of the retaining part 40 of the wire body 110, a bulging part 121 formed by using a change in the thickness of the lubricating coating layer 120.

Description

Guidewire

[0001] The present invention relates to a guidewire.

[0002] A guidewire is a medical device used to guide various catheters used to treat lesions occurring in blood vessels to the lesion. The guidewire has a core shaft (core member), a coil body (tubular member) arranged to cover the outer periphery of the distal end of the core shaft, and joints (distal joint, proximal joint, intermediate joint) that join the distal end, proximal end, and intermediate portion between the distal and proximal ends of the coil body to the core shaft (see, for example, Patent Document 1).

[0003] International Publication No. 2017 / 221425

[0004] The guidewire of Patent Document 1 tends to bend around the intermediate joint when advancing through a blood vessel, which can cause the intermediate fixing portion to come into contact with the blood vessel wall. The intermediate joint is fixed to the core member using a fixing material such as solder or brazing material, and is therefore harder and more rigid than the area surrounding the intermediate joint. Therefore, the intermediate joint may come into contact with the blood vessel wall and cause damage to the blood vessel wall when the guidewire is pushed in with more force than necessary.

[0005] 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 blood vessel damage when advancing through a blood vessel.

[0006] The above object of the present invention is achieved by any one of the following (1) to (9).

[0007] (1) A guidewire having a long wire body and a lubricating coating layer formed of a material that swells when wet and covering at least a portion of the wire body, wherein the wire body includes a core member, a tubular member arranged to cover the outer periphery of the tip end of the core member, and a retaining portion that holds a portion of the inner circumferential surface between the tip and base ends of the tubular member, and the lubricating coating layer has a bulge formed by a change in thickness of the lubricating coating layer on the outer circumferential surface of the wire body at the position of the retaining portion.

[0008] (2) The guide wire of (1) above, wherein the holding portion is an intermediate fixing portion that fixes the tubular member to the core member between a tip fixing portion that fixes the tip of the tubular member to the core member and a base end fixing portion that fixes the base end of the tubular member to the core member.

[0009] (3) The guide wire of (1) above, wherein the retaining portion is formed as part of the core member and is a protrusion that protrudes radially outward so as to retain the tubular member by contacting the inner surface of the tubular member.

[0010] (4) The guide wire according to any one of (1) to (3) above, wherein the bulging portion is provided in a region from the tip to the base end of the holding portion in the longitudinal direction.

[0011] (5) A guide wire according to any one of (1) to (4) above, wherein the lubricious coating layer has at least one of a distal coating portion covering the distal end of the holding portion and a proximal coating portion covering the proximal end of the holding portion in the inner cavity of the tubular member.

[0012] (6) A guide wire described in any of (1) to (5) above, wherein the tubular member has a void portion connecting the outer surface of the tubular member to the inner cavity at least at a position adjacent to the tip end of the holding portion and a position adjacent to the base end.

[0013] (7) The guide wire according to any one of (1) to (6) above, wherein the tubular member is a coil formed by winding a wire around the outer periphery of the core member.

[0014] (8) The guide wire according to (7) above, wherein the coil has an open winding portion at least at one of a position adjacent to the distal end of the holding portion and a position adjacent to the proximal end of the holding portion.

[0015] (9) A guide wire described in any of (1) to (8) above, wherein the tubular member has a distal tubular member and a proximal tubular member, and the holding portion holds the proximal end of the distal tubular member and the distal end of the proximal tubular member.

[0016] According to one embodiment of the present invention, a guidewire includes a bulging portion formed of a lubricious coating layer on the outer peripheral surface of a retaining portion that holds a tubular member from the inside at an intermediate portion between the distal end and proximal end of the wire body. The bulging portion is formed by varying the thickness of the lubricious coating layer and has an outer peripheral surface that includes a curved surface that is convex radially outward from the wire body. Therefore, the bulging portion is more rigid than the surrounding portion within a blood vessel. Even if the guidewire bends around the rigid retaining portion and comes into contact with the blood vessel wall, the bulging portion of the lubricious coating layer, which has moderate elasticity, can absorb the impact upon contact. Therefore, the guidewire can suppress blood vessel damage.

[0017] FIG. 1 is a partially enlarged cross-sectional view of the periphery of the distal end portion of a guidewire according to the present invention. FIG. 2 is a schematic cross-sectional view of a guidewire according to the present invention. FIG. 3 is a partially enlarged cross-sectional view of the periphery of an intermediate fixing portion of a guidewire according to the present invention. FIG. 4 is a view for explaining the shape of a bulging portion of a lubricious coating layer. FIG. 5 is a view showing a form in which a distal covering portion is formed on a holding portion. FIG. 6 is a view showing a form in which a distal covering portion and a proximal covering portion are not formed on a holding portion. FIG. 7 is a partially enlarged cross-sectional view of the periphery of the distal end portion of a guidewire of modified example 1. FIG. 8 is a partially enlarged cross-sectional view of the periphery of the distal end portion of a guidewire of modified example 2. FIG. 9 is a partially enlarged cross-sectional view showing another form of the guidewire of modified example 2. FIG. 10 is a partially enlarged cross-sectional view of the periphery of the distal end portion of a guidewire of modified example 3.

[0018] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The embodiments shown here are merely examples for embodying the technical idea of ​​the present invention and are not intended to limit the present invention. Furthermore, all other embodiments, examples, and operational techniques that can be conceived by those skilled in the art without departing from the spirit of the present invention are included in the scope and spirit of the present invention, as well as in the scope of the inventions set forth in the claims and their equivalents.

[0019] Furthermore, for the convenience of illustration and ease of understanding, the drawings attached to this specification may be represented schematically with the scale, aspect ratio, shape, etc. appropriately changed from the actual product, but these are merely examples and do not limit the interpretation of the present invention.

[0020] For ease of explanation, the following directions are defined herein. In Fig. 1, the "longitudinal direction" 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.

[0021] The side of the guidewire 100 that is inserted into a blood vessel is referred to as the “distal side,” and the side opposite the distal side (the side that is held by the surgeon) is referred to as the “proximal side.” The portion that includes a certain range from the distal end (the most distal end) along the longitudinal axis is referred to as the “distal portion,” and the portion that includes a certain range from the proximal end (the most proximal end) along the longitudinal axis is referred to as the “proximal end.”

[0022] In the following description, when ordinal numbers such as "first" and "second" are used, unless otherwise specified, they are used for convenience and do not stipulate any particular order.

[0023] The guidewire 100 according to the present invention is a medical device that is inserted into a blood vessel to guide a catheter or a stent for intravascular treatment to a lesion. 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.

[0024] As shown in FIGS. 1 and 2 , the guidewire 100 has a long wire body 110 and a lubricious coating layer 120 that covers at least a portion of the wire body 110 .

[0025] 1 or 2 , the wire body 110 constitutes the main body of the guidewire 100, and has a lubricious coating layer 120 formed on at least a portion of its outer circumferential surface. The wire body 110 includes a core member 10, a tubular member 20 arranged to cover the outer periphery of the distal end of the core member 10, a fixing part 30 that fixes the tubular member 20 to the core member 10, and a holding part 40 that holds a portion of the inner circumferential surface of the tubular member 20 between the distal end and the proximal end.

[0026] The core member 10 includes a first core portion 11 and a second core portion 12 disposed on the proximal side of the first core portion 11 and joined to the first core portion 11. The first core portion 11 is an elongated member extending along the longitudinal direction from the distal end of the second core portion 12 toward the distal side of the guidewire 100. The second core portion 12 is an elongated member extending from the proximal end of the first core portion 11 toward the proximal side of the guidewire 100. The first core portion 11 and the second core portion 12 can be joined by welding, brazing, or soldering. The first core portion 11 and the second core portion 12 may be connected using a cylindrical connecting member. The core member 10 may also be formed from a single continuous member.

[0027] The core member 10 can be made of a known material applicable to guidewires, such as a superelastic alloy such as a nickel-titanium alloy, or stainless steel. The first core portion 11 is preferably made of a material having lower rigidity than the material of the second core portion 12. The first core portion 11 and the second core portion 12 may be made of the same material.

[0028] The core member 10 includes a base-end covering layer 130 that covers at least a portion of the outer circumferential surface. In this embodiment, the base-end covering layer 130 is provided on the base end of the first core portion 11 and the outer circumferential surface of the second core portion 12. The base-end covering layer 130 can be formed of a low-friction material such as a fluorine-based resin (PTFE, ETFE, etc.) or a silicone resin.

[0029] As shown in Fig. 1, the tubular member 20 has a lumen 20a and is disposed so as to cover the outer periphery of the core member 10. The tubular member 20 is held from the inside by a holding portion 40 at a position between the distal end and proximal end of the tubular member 20. Furthermore, as shown in Fig. 1, the tubular member 20 has void portions 23 that communicate between the outer periphery of the tubular member 20 and the lumen 20a, at least at positions adjacent to the distal end and the proximal end of the holding portion 40.

[0030] In this embodiment, the tubular member 20 is a coil formed by helically winding a wire around the core member 10. The tubular member 20 is formed of a first coil 21 (distal-side tubular member) disposed at the distal end of the first core portion 11, and a second coil 22 (proximal-side tubular member) disposed on the proximal side of the first coil 21 and coaxially arranged with the first core portion 11. The first core portion 11 and the second coil 22 surround the first core portion 11 of the core member 10 and are fixed to the first core portion 11. It is preferable that the outer diameters of the first coil 21 and the second coil 22 are constant from the distal end to the proximal end. The tubular member 20 may be formed of one coil, or three or more coils.

[0031] The outer diameter of the wire material forming the first coil 21 is larger than the outer diameter of the wire material forming the second coil 22. The cross-sectional shape of the wire material forming the first coil 21 and the second coil 22 is preferably circular, but may also be elliptical or polygonal. Furthermore, the wire material forming the first coil 21 and the second coil 22 may be not only a single wire material but also a twisted wire consisting of two or more wire materials.

[0032] The wire forming the first coil 21 and the second coil 22 of the tubular member 20 can be made of a material such as a metal, such as stainless steel, a superelastic alloy, a cobalt-based alloy, gold, platinum, or tungsten, or an alloy containing any of these. In particular, the wire forming the first coil 21 is preferably made of a radiopaque material such as platinum. This improves the visibility of the guidewire 100 under radioscopy.

[0033] The material, outer diameter, cross-sectional shape, and pitch of the first coil 21 and second coil 22 of the wire forming the tubular member 20 can be selected appropriately depending on the purpose of the guide wire 100.

[0034] The base end of the first coil 21 and the tip end of the second coil 22 that form the tubular member 20 each have an open coil portion 20b, which is a portion with gaps between the wire of the coil. The first coil 21 and the second coil 22 are connected by intertwining portions of their open coil portions 20b. This allows the tubular member 20 to have a gap portion 23 that connects the outer circumferential surface of the tubular member 20 with the lumen 20a. The tubular member 20 has the gap portion 23, which makes it easier for the material forming the lubricating coating layer 120 to penetrate the lumen 20a of the tubular member 20. Note that the tubular member 20 may have a gap portion 23 between the wire forming the first coil 21 and the wire forming the second coil 22 at the connection portion between the first coil 21 and the second coil 22.

[0035] The tubular member 20 may be a pipe made of metal or resin. When the tubular member 20 is a pipe, the gap 23 is formed as a hole or slit penetrating the wall of the pipe.

[0036] The fixing part 30 is a member for fixing the tubular member 20 to the core member 10. The fixing part 30 has a tip fixing part 31 that fixes the tip of the tubular member 20 to the core member 10, an intermediate fixing part 32 that fixes the intermediate part of the tubular member 20 to the core member 10, and a base end fixing part 33 that fixes the base end of the tubular member 20 to the core member 10.

[0037] The intermediate fixing portion 32 is provided in the first core portion 11 at a position where the base end of the first coil 21 and the tip end of the second coil 22 are intertwined. The intermediate fixing portion 32 fixes the base end of the first coil 21 and the tip end of the second coil 22 to the first core portion 11 via a tubular member formed of metal, resin, or the like. The tubular member is disposed between the inner circumferential surface of the tubular member 20 and the outer circumferential surface of the core member 10, and reduces the gap between the inner circumferential surface of the tubular member 20 and the outer circumferential surface of the core member 10, making it easier to coaxially fix the tubular member 20 and the core member 10. The intermediate fixing portion 32 holds the tubular member 20 from the inside. The intermediate fixing portion 32 is provided at a position approximately 30 mm from the tip of the guidewire 100.

[0038] 3, the intermediate fixing portion 32 may be formed only from a fixing material such as solder or brazing. The intermediate fixing portion 32 is disposed between the outer circumferential surface of the core member 10 and the inner circumferential surface of the tubular member 20 to fix them together. In this way, the tubular member 20 is held by the intermediate fixing portion 32.

[0039] The fixing material forming the fixing portion 30 is a brazing material or a solder. The brazing material includes gold brazing and silver brazing. The solder includes tin-silver alloy solder, tin-lead alloy solder, etc. The fixing material may also be an adhesive.

[0040] 1 , the holding portion 40 is provided at a position between the distal end and proximal end of the tubular member 20, and at least a portion of the holding portion 40 contacts the inner circumferential surface of the tubular member 20 to hold the tubular member 20 from the inside. In the guidewire 100 of this embodiment, the intermediate fixing portion 32 corresponds to the holding portion 40. A plurality of holding portions 40 may be formed along the longitudinal direction between the distal end and proximal end of the tubular member 20.

[0041] 1, the gap 23 of the tubular member 20 is formed at a position adjacent to the distal end and a position adjacent to the proximal end of the holding portion 40. Note that the gap 23 may be formed at a position adjacent to either the distal end or the proximal end of the holding portion 40.

[0042] The lubricating coating layer 120 covers each part (the tubular member 20 , the fixed part 30 ) provided on the first core part 11 and a part of the first core part 11 .

[0043] At least a portion of the lubricious coating layer 120 is formed from a material that swells when wet. Such a lubricious coating layer 120 can be formed from a hydrophilic polymer. Examples of hydrophilic polymers that form the lubricious coating layer 120 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 lubricious coating layer 120 is preferably formed from a material that swells when wet and becomes a hydrogel. Hydrogels have appropriate elasticity, which can reduce the impact of contact between the guidewire 100 and the blood vessel wall.

[0044] The lubricious coating layer 120 includes a bulging portion 121 , a first coating portion 122 , a second coating portion 123 , a distal coating portion 124 , and a proximal coating portion 125 .

[0045] <Bulging Portion> As shown in Fig. 1 , the bulging portion 121 is a portion of the lubricant coating layer 120 where the thickness is increased. The bulging portion 121 is formed by varying the thickness of the lubricant coating layer 120, and has an outer peripheral surface that includes a curved surface that is convex radially outward of the guidewire 100. The bulging portion 121 is provided at the position of the holding portion 40 of the guidewire 100 in the longitudinal direction. When a plurality of holding portions 40 are formed, the bulging portion 121 may be arranged to correspond to the position of each holding portion 40.

[0046] 4 , the bulging portion 121 has a first region R1 in which the thickness of the bulging portion 121 increases from the distal end to the proximal end of the guidewire 100, a second region R2 that continues to the proximal end of the first region R1 and has a maximum outer diameter, and a third region R3 that continues to the proximal end of the second region R2 and decreases in thickness from the distal end to the proximal end. Note that in this specification, the thickness of the lubricating coating layer 120 refers to the thickness of the material that forms the lubricating coating layer 120 when it is swollen when wet.

[0047] 4 is a diagram showing a two-axis Cartesian coordinate system in which an axis along the central axis C of the guidewire 100 is the x-axis (the long axis direction of the guidewire 100) and an axis perpendicular to the x-axis and tangent to the tip of the bulging portion 121 is the y-axis (the radial direction of the guidewire 100), with the central axis C of the guidewire 100 placed in a natural state superimposed on the x-axis and the tip of the first region R1 of the guidewire 100 coinciding with the origin. The bulging portion 121 has a three-dimensional shape obtained by rotating a curve L formed by the outer circumferential surface of the bulging portion 121, which is represented in the first quadrant of the Cartesian coordinate system shown in FIG. 4, around the central axis C as the axis of rotation.

[0048] As shown in FIG. 4 , in the first quadrant of a Cartesian coordinate system, when the function y=f(x) represents the curve L formed by the outer peripheral surface of the bulging 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 range of x (x>0). In FIG. 4 , the first region R1 of the bulging portion 121 corresponds to the range of x where f′(x)>0 is satisfied, distal to the maximum point P1 (first derivative f′(x)=0) on the curve L where the function y=f(x) is maximized. In FIG. 4 , the second region R2 of the bulging portion 121 corresponds to the range of x where f′(x)=0 (maximum point P1). In FIG. 4 , the third region R3 of the bulging portion 121 corresponds to the range of x where f′(x)<0 is satisfied, proximal to the maximum point P1 on the curve L.

[0049] The first region R1 of the bulging portion 121 has a first region distal end R11 that is convex radially inward and extends over a predetermined range from the distal end of the first region R1 toward the distal end of the first region R1, and a first region proximal end R12 that is convex radially outward and extends proximal to the proximal end of the first region distal end R11. The first region R1 of the bulging portion 121 has a first inflection point P2 on the curve L in FIG. 4 where f″(x)=0 and the sign of f″(x) is inverted, causing the curve L to change its concavity and convexity. The first region distal end R11 corresponds to a section where f′(x)>0 and f″(x)>0, where the function y=f(x) is convex downward, with the first inflection point P2 on the curve L in FIG. 4 as the boundary, and where f′(x)>0 and f″(x)>0, where the function y=f(x) is convex upward. The first region proximal end R12 corresponds to a section where f′(x)>0 and f″(x)<0, where the function y=f(x) is convex upward. 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 L is always above the curve.

[0050] The second region R2 of the bulging portion 121 is the portion where the bulging portion 121 has the maximum outer diameter. The second region R2 connects the first region base end R12 of the first region R1 and the third region tip end R31 of the third region R3. In FIG. 4, the second region R2 exists as the boundary point between the first region R1 and the third region R3, and coincides with the maximum point P1 on the curve L where the function y = f(x) is maximum. In FIG. 4, the second region R2 is where f'(x) = 0.

[0051] The third region R3 of the bulging portion 121 has a third region distal end R31 that is convex radially outward and extends within a predetermined range from the base end of the second region R2 to the distal end of the third region R3, and a third region proximal end R32 that is convex radially inward and extends proximal to the third region distal end R31. The third region R3 of the bulging portion 121 has a second inflection point P3 on the curve L in FIG. 4 where f″(x)=0 and the sign of f″(x) is inverted, changing the concavity and convexity of the curve L. The third region distal end R31 corresponds to the section where f′(x)<0 and f″(x)<0, where the function y=f(x) is convex upward, with the second inflection point P3 on the curve L in FIG. 4 as the boundary, and where f′(x)<0 and f″(x)>0, where the function y=f(x) is convex downward. The third region proximal end R32 corresponds to the section where f′(x)<0 and f″(x)>0, where the function y=f(x) is convex downward.

[0052] In the lubricating coating layer 120, the outer circumferential surface of the bulging portion 121 is smoothly connected to the outer circumferential surface of the first coating portion 122 via a first region distal end portion R11 located at the connection between the bulging portion 121 and the first coating portion 122. In the lubricating coating layer 120, the outer circumferential surface of the bulging portion 121 is smoothly connected to the outer circumferential surface of the second coating portion 123 via a third region proximal end portion R32 located at the connection between the bulging portion 121 and the second coating portion 123. As a result, in the guidewire 100, the connection portions of the lubricating coating layer 120 between the bulging portion 121 and the first coating portion 122 and between the bulging portion 121 and the second coating portion 123 are less likely to get caught on the blood vessel wall or the lumen of the catheter, thereby preventing peeling of the lubricating coating layer 120.

[0053] The bulging portion 121 has an outer peripheral surface including a curved surface that is convex radially outward, formed by varying the thickness of a material that swells when wet, and covers the outer peripheral surface of the wire body 110 at least at the position of the holding portion 40 of the guidewire 100. In other words, the bulging portion 121 covers the outer peripheral surface of the holding portion 40 of the wire body 110 and / or the outer peripheral surface of the tubular member 20 at the position of the holding portion 40. This allows the bulging portion 121 to absorb the impact when the guidewire 100 comes into contact with a blood vessel wall, thereby preventing blood vessel damage.

[0054] The bulge 121 is preferably provided so as to cover the entire holding portion 40. That is, the length X1 of the bulge 121 along the longitudinal direction is preferably longer than the length X2 of the holding portion 40 along the longitudinal direction, and the bulge 121 is preferably provided so as to cover at least the region from the tip to the base end of the holding portion 40. Note that it is sufficient if at least a portion of the bulge 121 is formed on the outer circumferential surface of the wire body 110 at the position of the holding portion 40. The length X1 of the bulge 121 along the longitudinal direction is preferably 15% to 125% of the length X2 of the holding portion 40 along the longitudinal direction, more preferably 75% to 125%, and even more preferably 100% to 125%.

[0055] <First Covering Portion> As shown in Fig. 1 , the first covering portion 122 is a portion of the lubricating coating layer 120 that is closer to the tip than the bulge 121. The first covering portion 122 is preferably provided so as to cover the tip of the wire body 110. That is, the first covering portion 122 is preferably provided so as to cover at least the first coil 21. The first covering portion 122 is formed with a substantially constant thickness. The outer circumferential surface of the first covering portion 122 is smoothly connected to the outer circumferential surface of the bulge 121. Note that the first covering portion 122 does not necessarily have to be provided.

[0056] <Second coating portion> As shown in Fig. 1 , the second coating portion 123 is a portion of the lubricating coating layer 120 closer to the base end than the bulging portion 121. The second coating portion 123 is preferably provided so as to cover at least the second coil 22. The second coating portion 123 is formed with a substantially constant thickness. The outer circumferential surface of the second coating portion 123 is smoothly connected to the outer circumferential surface of the bulging portion 121.

[0057] 1 , when the lubricating coating layer 120 is in a swollen state, the maximum radial thickness t1 of the bulging portion 121 is greater than the maximum radial thickness t2 of the first coating portion 122 and the maximum radial thickness t3 of the second coating portion 123 (t1 > t2, t3). Furthermore, in the guidewire 100, the maximum outer diameter d1 of the bulging portion 121 is greater than the maximum outer diameter d2 of the first coating portion 122 and the maximum outer diameter d3 of the second coating portion 123 (d1 > d2, d3). This allows the bulging portion 121 to more effectively exert a cushioning effect on the blood vessel wall. The maximum radial thickness t1 of the bulging portion 121, the maximum radial thickness t2 of the first coating portion 122, and the maximum radial thickness t3 of the second coating portion 123 are the thicknesses of the lubricating coating layer 120 at the outer circumferential surfaces of the first coil 21 and the second coil 22 (the radially outermost positions of the wires forming the first coil 21 and the second coil 22), respectively.

[0058] The maximum radial thickness t1 of the bulging portion 121 when the lubricating coating layer 120 is in a swollen state is preferably 3 μm to 12 μm, more preferably 5 μm to 8 μm. The maximum radial thickness t1 of the bulging portion 121 when the lubricating coating layer 120 is in a dry state is preferably 0.4 μm to 1.2 μm, more preferably 0.8 μm to 1.2 μm. The maximum radial thickness t2 of the first coating portion 122 and the maximum radial thickness t3 of the second coating portion 123 when the lubricating coating layer 120 is in a swollen state are preferably 1 μm to 8 μm, more preferably 2 μm to 7 μm. The maximum radial thickness t2 of the first coating portion 122 and the maximum radial thickness t3 of the second coating portion 123 when the lubricating coating layer 120 is in a dry state are preferably 0.2 μm to 0.8 μm, more preferably 0.5 μm. The maximum radial thickness t2 of the first coating portion 122 and the maximum radial thickness t3 of the second coating portion 123 may be approximately equal to or different from each other. For example, when the lubricating coating layer 120 is in a swollen state, the maximum radial thickness t2 of the first coating portion 122 is smaller than the maximum radial thickness t3 of the second coating portion 123, and it is preferable that the maximum radial thickness t2 of the first coating portion 122 is 2 μm or more and 4 μm or less, and the maximum radial thickness t3 of the second coating portion 123 is 4 μm or more and 7 μm or less.

[0059] The lubricant coating layer 120 may be configured only with the bulging portion 121. Furthermore, the lubricant coating layer 120 may have coating portions other than the bulging portion 121, the first coating portion 122, and the second coating portion 123.

[0060] The first coating portion 122 and the second coating portion 123 of the lubricating coating layer 120 are preferably formed from the same material as the bulging portion 121. However, the bulging portion 121, the first coating portion 122, and the second coating portion 123 may be formed from different materials. For example, the bulging portion 121 and the second coating portion 123 may be formed from a material that swells when wet, and the first coating portion 122 may be partially formed from silicone.

[0061] 1 , the tip covering portion 124 is a portion that covers the tip of the holding portion 40 in the lumen 20a of the tubular member 20. The tip covering portion 124 is connected to the bulge portion 121 via the gap portion 23 of the tubular member 20. This firmly fixes the lubricating coating layer 120 to the holding portion 40 and the tubular member 20, thereby suppressing peeling of the lubricating coating layer 120 near the tip of the holding portion 40.

[0062] 1 , the proximal end covering portion 125 is a portion that covers the proximal end of the holding portion 40 in the lumen 20a of the tubular member 20. The proximal end covering portion 125 is connected to the bulge portion 121 via the gap portion 23 of the tubular member 20. This allows the lubricous coating layer 120 to be firmly fixed to the holding portion 40 and the tubular member 20, thereby preventing peeling of the lubricous coating layer 120 near the proximal end of the holding portion 40.

[0063] Because the holding portion 40 of the guidewire 100 has a difference in rigidity from the surrounding area of ​​the holding portion 40, it is prone to bending around the surrounding area starting from the holding portion 40, and this bending can cause peeling of the bulging portion 121. The guidewire 100 can effectively prevent peeling of the bulging portion 121 by providing the lubricous coating layer 120 with a distal coating portion 124 and a proximal coating portion 125, thereby firmly fixing the lubricous coating layer 120 to the holding portion 40 and the tubular member 20.

[0064] As shown in Fig. 5A, the lubricious coating layer 120 may be configured to include at least one of the distal coating portion 124 and the proximal coating portion 125. Alternatively, as shown in Fig. 5B, the lubricious coating layer 120 may not include the distal coating portion 124 or the proximal coating portion 125.

[0065] The lubricating coating layer 120 can be formed by immersing the wire body 110 in a solution containing a material for forming the lubricating coating layer 120, vertically lifting the wire body 110 out of the solution, and then drying the wire body 110. The wire body 110 may be immersed in the solution once or multiple times.

[0066] When the wire body 110 is pulled out of the solution, a portion of the solution adhering to the outer circumferential surface of the wire body 110 forms a liquid pool that covers the entire circumference of the distal end of the wire body 110 due to the action of surface tension. The bulge 121 can be formed by drying the liquid pool formed at the distal end of the wire body 110. When the wire body 110 is pulled out of the solution, the solution adhering to the outer circumferential surface of the wire body 110 flows downward due to gravity, thereby forming the first coating portion 122 and the second coating portion 123 as layers with a substantially uniform thickness. The distal coating portion 124 and the proximal coating portion 125 can be formed by flowing a material for forming the lubricating coating layer 120 into the lumen 20a of the tubular member 20 through the void portion 23 of the tubular member 20. Alternatively, the bulge 121 may be formed by applying the material for forming the lubricating coating layer 120 to the outer circumferential surface of the wire body 110 at the position where the bulge 121 is desired to be formed.

[0067] The first coating portion 122 may be formed by removing the material forming the bulge portion 121 and the second coating portion 123 from the tip of the wire body 110 and applying another material capable of forming a lubricating coating layer 120, such as silicone, to the wire body 110.

[0068] [Modifications] The guidewire 100 of the present invention can also be implemented by making appropriate modifications, as in the following modifications. The following description of each modification will mainly focus on differences from the above-described embodiment, and components having equivalent functions to those of other embodiments will be denoted by the same or related reference numerals, with detailed description omitted and no particular mention made. Furthermore, the configuration, members, and usage method may be similar to those of each embodiment. Furthermore, each modification can be implemented by appropriately selecting necessary components from those shown in each modification and combining them with other embodiments, without departing from the spirit of the present invention.

[0069] <Modification 1> A guidewire 100A according to Modification 1 will now be described. Fig. 6 is an enlarged cross-sectional view of the distal end portion and its surroundings of guidewire 100A according to Modification 1.

[0070] 6, the guidewire 100A has a lubricating coating layer 120 that covers at least a portion of the wire body 110. The guidewire 100A differs from the above-described configurations in that the second region R2 of the bulging portion 121 of the lubricating coating layer 120 has a flat portion 126 that extends a predetermined length in the longitudinal direction.

[0071] In the guidewire 100A, the second region R2 of the bulging portion 121 has a flat portion 126 extending a predetermined length in the longitudinal direction. The thickness of the bulging portion 121 at the flat portion 126 is substantially constant along the longitudinal direction and is the maximum radial thickness t1 of the bulging portion 121.

[0072] By providing flat portion 126 in second region R2 of bulging portion 121, guidewire 100A can increase the length along the longitudinal direction without excessively increasing the outer diameter of bulging portion 121. Therefore, even if guidewire 100A has a long length along the longitudinal direction of holding portion 40, the outer diameter of bulging portion 121 can be set to a size that does not interfere with use.

[0073] In the guide wire 100A of modified example 1, by providing a flat portion 126 in the second region R2 of the bulge portion 121, it is possible to form a bulge portion 121 that covers the entire length of the holding portion 40 while maintaining an outer diameter that does not interfere with use.

[0074] <Modification 2> A guidewire 100B according to Modification 2 will now be described. Fig. 7 is an enlarged cross-sectional view of the distal end portion and its surroundings of a guidewire 100B according to Modification 2.

[0075] 7, the guidewire 100B has a lubricious coating layer 120 that covers at least a portion of the wire body 110. The guidewire 100B differs from the above-described configurations in that the retaining portion 40 is formed as a part of the core member 10.

[0076] 7 , the guidewire 100B has a protruding portion 13 formed to protrude concentrically radially outward from the first core portion 11. In the guidewire 100B, the protruding portion 13 corresponds to the holding portion 40.

[0077] The protrusion 13 holds the tubular member 20 by contacting the inner circumferential surface of the tubular member 20. The protrusion 13 is preferably provided in the first core portion 11 at a position corresponding to the connection portion between the first coil 21 and the second coil 22. Note that the protrusion 13 may be fixed to the tubular member 20 via a fixing material, as shown in FIG. 8 .

[0078] <Modification 3> A guidewire 100C according to Modification 3 will now be described. Fig. 9 is an enlarged cross-sectional view of the distal end portion and its surroundings of the guidewire 100C according to Modification 3.

[0079] As shown in FIG. 9, a guidewire 100C differs from the above-described configuration in the shape of the outer circumferential surface of the lubricious coating layer 120 that covers at least a portion of the wire body 110.

[0080] As shown in Fig. 9 , in the guidewire 100C, the shape of the outer peripheral surface of the first coating portion 122 can be an uneven shape that follows the outer periphery of the wire material that forms the first coil 21. Also, as shown in Fig. 9 , in the guidewire 100C, the shape of the outer peripheral surface of the second coating portion 123 can be an uneven shape that follows the outer periphery of the wire material that forms the second coil 22. In the guidewire 100C, when the thickness of the lubricous coating layer 120 is very thin, the outer peripheral surface of the lubricous coating layer 120 that covers the tubular member 20 can have an uneven shape that follows the outer periphery of the tubular member 20 (first coil 21, second coil) as shown in Fig. 9 .

[0081] 9 , the guidewire 100C has both the first covering portion 122 and the second covering portion 123 formed with the aforementioned uneven shape, but only one of the covering portions may have an uneven shape that follows the coil shape. That is, the guidewire 100C may have the first covering portion 122 with an outer peripheral surface that has an uneven shape that follows the outer peripheral shape of the first coil 21, and the second covering portion 123 with an outer peripheral surface that is flat along the longitudinal axis. Alternatively, the guidewire 100C may have the first covering portion 122 with an outer peripheral surface that has an uneven shape that follows the outer peripheral shape of the second coil 22.

[0082] [Effects] As described above, the guide wire 100 according to the present invention has a long wire body 110 and a lubricating coating layer 120 formed of a material that swells when wet and covering at least a portion of the wire body 110, wherein the wire body 110 includes a core member 10, a tubular member 20 arranged to cover the outer periphery of the tip end of the core member 10, and a retaining portion 40 that retains a portion of the inner circumferential surface between the tip and base ends of the tubular member 20, and the lubricating coating layer 120 has a bulge 121 formed by a change in thickness of the lubricating coating layer 120 on the outer circumferential surface at the position of the retaining portion 40 of the wire body 110.

[0083] With this configuration, the guidewire 100 has a bulge 121 formed by the lubricating coating layer 120 on the outer peripheral surface of the wire body 110 at the position of the holding portion 40, which holds the tubular member 20 from the inside between the distal end and proximal end of the wire body 110. The bulge 121 is formed by varying the thickness of the lubricating coating layer 120 and has an outer peripheral surface that includes a curved surface that is convex radially outward of the wire body 110. Therefore, even if the guidewire 100 is more rigid than the surrounding area within a blood vessel and bends around the hard holding portion 40 and comes into contact with the blood vessel wall, the bulge 121 of the lubricating coating layer 120, which has moderate elasticity, can absorb the impact upon contact. Therefore, the guidewire 100 can suppress blood vessel damage.

[0084] In addition, the holding portion 40 of the guide wire 100 may be an intermediate fixing portion 32 that fixes the tubular member 20 to the core member 10 between a tip fixing portion 31 that fixes the tip of the tubular member 20 to the core member 10 and a base end fixing portion 33 that fixes the base end of the tubular member 20 to the core member 10.

[0085] With this configuration, the guidewire 100 has a bulge 121 formed of the lubricating coating layer 120 on the outer peripheral surface at the position of the intermediate fixing portion 32, which functions as a retaining portion 40 that holds the tubular member 20 from the inside between the distal end and proximal end of the wire body 110. The bulge 121 is formed by varying the thickness of the lubricating coating layer 120 and has an outer peripheral surface that includes a curved surface that is convex radially outward of the wire body 110. Therefore, even if the guidewire 100 is more rigid than the surrounding area within a blood vessel and bends around the hard intermediate fixing portion 32 and comes into contact with the blood vessel wall, the bulge 121 of the lubricating coating layer 120 has appropriate elasticity to cushion the impact upon contact. Therefore, the guidewire 100 can suppress blood vessel damage.

[0086] In addition, the holding portion 40 of the guide wire 100 may be a protrusion 13 formed as part of the core member 10 and protruding radially outward so as to hold the tubular member 20 by contacting the inner surface of the tubular member 20.

[0087] With this configuration, the guidewire 100 has a bulge 121 formed of the lubricating coating layer 120 on the outer peripheral surface at the position of the protrusion 13, which functions as a retaining portion 40 that retains the tubular member 20 from the inside between the distal end and proximal end of the wire body 110. The bulge 121 is formed by varying the thickness of the lubricating coating layer 120 and has an outer peripheral surface that includes a curved surface that is convex radially outward of the wire body 110. Therefore, the bulge 121 has higher rigidity than the surrounding area within a blood vessel. Even if the guidewire 100 bends around the hard protrusion 35 and comes into contact with the blood vessel wall, the bulge 121 of the lubricating coating layer 120 has moderate elasticity and can absorb the impact upon contact. Therefore, the guidewire 100 can suppress blood vessel damage.

[0088] Furthermore, the bulging portion 121 of the guidewire 100 may be provided in the region from the tip to the base end of the holding portion 40 in the longitudinal direction.

[0089] With this configuration, the guidewire 100 has the holding portion 40 covered over the entire length with the bulging portion 121 of the lubricious coating layer 120, so that damage to blood vessels can be effectively prevented.

[0090] In addition, the lubricating coating layer 120 of the guide wire 100 may be configured to have at least one of a tip coating portion 124 that covers the tip of the holding portion 40 and a base coating portion 125 that covers the base end of the holding portion 40 in the inner cavity 20a of the tubular member 20.

[0091] With this configuration, the guide wire 100 can have the lubricating coating layer 120 firmly fixed to the tubular member 20, the holding portion 40, the core member 10, etc. at the tip and / or base end of the holding portion 40, thereby preventing the bulge portion 121 from peeling off from the wire body 110.

[0092] In addition, the tubular member 20 of the guide wire 100 may be configured to have a void portion 23 that connects the outer surface of the tubular member 20 to the inner cavity at at least one of a position adjacent to the tip end of the holding portion 40 and a position adjacent to the base end.

[0093] With this configuration, the guidewire 100 allows the material forming the lubricating coating layer 120 to easily enter the lumen 20a of the tubular member 20 from the gap 23. Therefore, the guidewire 100 can easily form a distal coating portion 124 that covers the distal end of the holding portion 40 and a proximal coating portion 125 that covers the proximal end of the holding portion 40.

[0094] Furthermore, the tubular member 20 of the guidewire 100 may be a coil wound around the outer periphery of the core member 10 .

[0095] This configuration improves the flexibility of the guidewire 100 at the distal end.

[0096] The coil may also be configured to have an open winding portion 20b at least at one of a position adjacent to the tip end of the holding portion 40 and a position adjacent to the base end.

[0097] With this configuration, the guide wire 100 has a loosely wound portion 20b at least at one of the positions adjacent to the tip and the base end of the coil holding portion 40, which is the tubular member 20, so that the gap portion 23 can be easily formed simply by changing the pitch of the coil.

[0098] In addition, the tubular member 20 of the guide wire 100 has a tip-side tubular member (first coil 21) and a base-side tubular member (second coil 22), and the holding portion 40 holds the base end of the tip-side tubular member and the tip end of the base-side tubular member.

[0099] With this configuration, the guidewire 100 has a distal tubular member (first coil 21) and a proximal tubular member (second coil 22), and therefore the physical properties can be changed between the distal and proximal sides of the tubular member 20. This allows the guidewire 100 to improve the flexibility of the distal end and the visibility under radioscopy. Furthermore, the guidewire 100 has a bulge 121 provided in the holding portion 40, which is the connection portion between the distal tubular member and the proximal tubular member, and therefore can suppress vascular damage.

[0100] This application is based on Japanese Patent Application No. 2023-154218, filed on September 21, 2023, the disclosure of which is incorporated herein by reference in its entirety.

[0101] REFERENCE SIGNS LIST 10 Core member, 11 First core portion, 12 Second core portion, 13 Protruding portion, 20 Tubular member (20a Inner cavity, 20b Open winding portion), 21 First coil, 22 Second coil, 23 Gap portion, 30 Fixing portion, 31 Distal fixing portion, 32 Intermediate fixing portion, 33 Proximal fixing portion, 40 Holding portion, 100, 100A, 100B, 100C Guide wire, 110 Wire body, 120 Lubricious coating layer, 121 Bulging portion, 122 First coating portion, 123 Second coating portion, 124 Distal coating portion, 125 Proximal coating portion, 126 Flat portion, 130 Proximal coating layer, C Central axis, d1 Maximum outer diameter of bulging portion, d2 Maximum outer diameter of first coated portion, d3 Maximum outer diameter of second coated portion, R1 First region, R2 Second region, R3 Third region, R11 Tip of first region, R12 Base of first region, R31 Tip of third region, R32 Base of third region, t1 Maximum radial thickness of bulge portion, t2 Maximum radial thickness of first coated portion, t3 Maximum radial thickness of second coated portion, X1 Length along the longitudinal direction of bulge portion, X2 Length along the longitudinal direction of retaining portion.

Claims

1. A guidewire having a long wire body and a lubricating coating layer formed of a material that swells when wet and covering at least a portion of the wire body, wherein the wire body includes a core member, a tubular member arranged to cover the outer periphery of the tip end of the core member, and a retaining portion for retaining a portion of the inner periphery between the tip and base ends of the tubular member, and the lubricating coating layer has a bulge formed by a change in thickness of the lubricating coating layer on the outer periphery of the wire body at the position of the retaining portion.

2. A guide wire as described in claim 1, wherein the holding portion is an intermediate fixing portion that fixes the tubular member to the core member between a tip fixing portion that fixes the tip of the tubular member to the core member and a base end fixing portion that fixes the base end of the tubular member to the core member.

3. A guide wire as described in claim 1, wherein the retaining portion is formed as part of the core member and is a protrusion that protrudes radially outward so as to retain the tubular member by contacting the inner surface of the tubular member.

4. A guidewire as claimed in any one of claims 1 to 3, wherein the bulge is provided in the region from the tip to the base end of the holding portion in the longitudinal direction.

5. A guidewire as claimed in any one of claims 1 to 3, wherein the lubricating coating layer has, within the inner cavity of the tubular member, at least one of a distal coating portion covering the distal end of the holding portion and a proximal coating portion covering the proximal end of the holding portion.

6. A guidewire as claimed in any one of claims 1 to 3, wherein the tubular member has a void portion communicating between the outer circumferential surface of the tubular member and the inner cavity at least at one of a position adjacent to the tip end and a position adjacent to the base end of the holding portion.

7. A guidewire as claimed in any one of claims 1 to 3, wherein the tubular member is a coil formed by winding a wire so as to cover the outer periphery of the core member.

8. The guidewire according to claim 7, wherein said coil has an open winding portion at least in one of a position adjacent to the distal end and a position adjacent to the proximal end of said holding portion.

9. A guidewire as claimed in any one of claims 1 to 3, wherein the tubular member has a distal tubular member and a proximal tubular member, and the holding portion holds the proximal end of the distal tubular member and the distal end of the proximal tubular member.

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