JP7748835B2 - Guidewire - Google Patents

Description

This disclosure relates to a guidewire.

Guidewires having a coil body are known (see, for example, Patent Documents 1 and 2). Guidewires are inserted into body cavities such as blood vessels to assist in the insertion of medical devices such as catheters and stents.

Japanese Patent Application Laid-Open No. 2004-230142 International Publication No. 2021/117657

It is not easy to properly set the flexibility of a coil body while ensuring its pushability.

The present disclosure therefore aims to provide a guidewire in which the flexibility of the coil body can be easily adjusted.

In one aspect of the present disclosure, the guidewire has at least one wire forming a coil body, and the at least one wire has at least one groove.

In one embodiment of the present disclosure, the guidewire has at least one groove provided only in the distal end of the guidewire.

In one embodiment of the present disclosure, the guidewire is a guidewire in which the at least one groove has a pitch that decreases from the proximal end toward the distal end of the guidewire.

In one embodiment of the present disclosure, the guidewire is a guidewire in which the width or depth of the at least one groove increases from the proximal end toward the distal end of the guidewire.

In one embodiment of the present disclosure, the guidewire is a guidewire in which the at least one strand forms a contrast marker.

In one embodiment of the present disclosure, the guidewire is a guidewire in which the at least one wire forms the distal end of the guidewire or a portion extending from the distal end to the proximal end of the guidewire.

In one embodiment of the present disclosure, the guidewire is a guidewire in which the at least one groove is provided in a portion of the at least one wire that extends around the entire circumference of the guidewire.

In one embodiment of the present disclosure, the guidewire is such that the at least one groove is not provided in a portion of the at least one wire aligned in a first direction perpendicular to the axial direction of the guidewire, but is provided in a portion of the at least one wire aligned in a second direction perpendicular to both the axial direction of the guidewire and the first direction.

In one embodiment of the present disclosure, the guidewire is a guidewire in which the at least one groove is provided on both sides or only one side of the at least one strand itself in the second direction.

In one embodiment of the present disclosure, the guidewire is a guidewire in which the at least one groove is provided on both sides or only one side of the at least one wire itself in the axial direction of the guidewire.

In one embodiment of the present disclosure, the guidewire is a guidewire in which the at least one groove extends in the axial direction of the guidewire.

In one embodiment of the present disclosure, the guidewire is a guidewire in which the at least one groove is provided only in a portion of the at least one wire that is located radially outward of the guidewire.

In one embodiment of the present disclosure, the guidewire is a guidewire in which the at least one groove is provided in a spiral or annular shape on the outer circumferential surface of the at least one wire itself.

In one embodiment of the present disclosure, a method for manufacturing a guidewire includes an irradiation step of irradiating the at least one wire with laser light in a state in which the coil body is formed, thereby forming the at least one groove.

This disclosure provides a guidewire in which the flexibility of the coil body can be easily adjusted.

1 is a partial cross-sectional side view showing a guidewire according to a first embodiment. FIG. FIG. 2 is an enlarged view of a portion of FIG. 1. 3 is a cross-sectional view taken along line AA in FIG. 2. FIG. 2 is a side view showing a modified example of the coil body shown in FIG. 1 . FIG. 2 is a side view showing a modified example of the coil body shown in FIG. 1 . FIG. 2 is a side view showing a modified example of the coil body shown in FIG. 1 . FIG. 2 is a side view showing a modified example of the coil body shown in FIG. 1 . FIG. 10 is a partial cross-sectional side view showing a guidewire according to a second embodiment. FIG. 10 is a partial cross-sectional side view showing a guidewire according to a third embodiment. FIG. 10 is a partial cross-sectional side view showing a guidewire according to a fourth embodiment.

Embodiments of the present disclosure will be described in detail below with reference to the drawings.

As shown in Figures 1 and 2, the guidewire 1 according to the first embodiment of the present disclosure has a core portion 8, a coil portion 7, a fixing portion 9, and a covering portion 10. The core portion 8 has a first core 8a and a second core 8b. The coil portion 7 has a coil body 2 (hereinafter also referred to as the first coil body 2) and another coil body (hereinafter also referred to as the second coil body 6). The fixing portion 9 has a first fixing material 9a, a second fixing material 9b, and a third fixing material 9c. The covering portion 10 has a first covering layer 10a, a second covering layer 10b, a third covering layer 10c, and a fourth covering layer 10d. The guidewire 1 according to this embodiment is suitable for, for example, percutaneous coronary intervention (PCI).

Hereinafter, the end located forward when the guidewire 1 is introduced into a body cavity such as a blood vessel will be referred to as the tip, and the opposite end will be referred to as the base, and the direction along the axis O extending longitudinally along the center of the guidewire 1 will be referred to as the axial direction, the direction along a straight line perpendicular to the axis O will be referred to as the radial direction, and the direction circumferentially around the axis O will be referred to as the circumferential direction. Note that in the drawings, the radial dimensions are shown larger than they actually are to make the structure easier to understand.

The first core 8a is linear and extends axially around the axis O, and is made of a metal material such as a superelastic alloy, such as a nickel (Ni)-titanium (Ti) alloy. The radial dimension of the first core 8a decreases from the base end to the tip end. The cross-sectional shape of the first core 8a (the shape in a cross section perpendicular to the axial direction) is circular throughout its entire length. The base end surface 8c of the first core 8a is joined to the tip end surface of the second core 8b by welding.

The second core 8b is linear and extends axially around the axis O, and is made of a metal material such as stainless steel. The cross-sectional shape of the second core 8b is circular throughout its entire length.

The first coil body 2 is formed in a spiral shape centered on the axis O using at least one wire 3. Specifically, the first coil body 2 is formed in a spiral shape using a single wire 3. The first coil body 2 forms a radiopaque marker. That is, the first coil body 2 is formed from a material such as a metal, including materials with low X-ray transparency such as Pt and Au. The first coil body 2 is configured as a marker with radiopaque properties. The cross-sectional shape of the wire 3 itself that forms the first coil body 2 (the shape of a cross section perpendicular to the longitudinal direction of the wire 3 itself) is circular. The first coil body 2 forms only the tip portion 1a of the guidewire 1.

The second coil body 6 is located closer to the base end than the first coil body 2. The second coil body 6 is formed from a single wire 3 and is spirally shaped about the axis O. The second coil body 6 is made of a metal material such as stainless steel. The wire 3 that forms the second coil body 6 has a circular cross-sectional shape.

The outer diameter of the wire 3 of the first coil body 2 itself is larger than the outer diameter of the wire 3 of the second coil body 6. This improves the X-ray contrast of the first coil body 2, allowing the surgeon to clearly recognize the position of the tip 1a of the guidewire 1.

The first coil body 2 and the second coil body 6 each cover the first core 8a from the radial outside. The inner diameter of the first coil body 2 is larger than the outer diameter of the portion of the first core 8a located inside the first coil body 2. The inner diameter of the second coil body 6 is larger than the outer diameter of the portion of the first core 8a located inside the second coil body 6. The first coil body 2 and the second coil body 6 have approximately the same outer diameter. In other words, the coil portion 7 has an approximately uniform outer diameter in the axial direction.

The tip end of the first coil body 2 is fixed to the first core 8a by a first fixing material 9a. The base end of the first coil body 2 is fixed to the first core 8a by a second fixing material 9b. The tip end of the second coil body 6 is fixed to the first core 8a by a second fixing material 9b. The base end of the second coil body 6 is fixed to the first core 8a by a third fixing material 9c. The first fixing material 9a, the second fixing material 9b, and the third fixing material 9c are each a brazing material such as solder.

The first coating layer 10a coats the entire first coil body 2, second coil body 6, first fixing material 9a, second fixing material 9b, and third fixing material 9c. The second coating layer 10b coats the portion of the first core 8a closer to the base end than the third fixing material 9c, excluding the base end. The third coating layer 10c coats the joint between the first core 8a and the second core 8b. The fourth coating layer 10d coats the portion of the second core 8b excluding the tip and base ends.

The first coating layer 10a is formed, for example, from a hydrophilic polymer. The second coating layer 10b and the fourth coating layer 10d are each formed, for example, from a fluorine-based resin. The third coating layer 10c is formed, for example, from a resin such as silicone.

As shown in Figures 2 and 3, at least one strand 3 forming the first coil body 2 has at least one spiral groove 4. Specifically, the outer surface of the strand 3 forming the first coil body 2 itself has a double spiral groove 4 formed by two grooves 4. Therefore, the first coil body 2 has a groove portion 5 formed by two grooves 4. Each groove 4 extends spirally along the axial direction (longitudinal direction) of the strand 3 itself. Each groove 4 has two opposing side surfaces 4a and a bottom surface 4b connecting these side surfaces 4a. The first coating layer 10a penetrates into each groove 4, resulting in good adhesion to the first coil body 2.

Each groove 4 has a constant width W (distance between both side surfaces 4a) and a constant depth D (depth D of the bottom surface 4b). The groove portions 5 form a predetermined pattern in which parts of the grooves 4 are arranged at a predetermined pitch P in the width direction of the groove 4. The pitch P of the groove portions 5 is constant.

Each groove 4 is provided over the entire axial length of the wire 3 itself. Therefore, the groove portion 5 is provided over the entire circumference of the first coil body 2, centered on the axis O.

The method for forming each groove 4 is not particularly limited. For example, each groove 4 can be formed by rotating the wire 3 itself, which has been stretched straight before being coiled, in the circumferential direction while feeding it in the axial direction, and then cutting the outer surface of the wire 3 itself with a laser or the like irradiated perpendicular to the axial direction.

The outer surface of the wire 3 that forms the second coil body 6 does not have grooves 4. In other words, the grooves 4 are provided only in the first coil body 2. Therefore, the grooves 4 are provided only in the distal end portion 1a of the guidewire 1.

According to this embodiment, the provision of the groove portion 5 ensures the X-ray contrast of the first coil body 2 while increasing its flexibility. Furthermore, by appropriately setting the width W, depth D, and pitch P of the grooves 4 in the groove portion 5, the flexibility of the distal end portion 1a of the guidewire 1 can be easily adjusted.

The first coil body 2 and the second coil body 6 may each have a spiral shape other than a single spiral, for example, a double spiral, or a triple or more multiple spiral. The cross-sectional shape of the wire 3 forming the first coil body 2 may be other than circular, for example, elliptical, rectangular, square, polygonal, etc. The cross-sectional shape of the wire 3 forming the second coil body 6 may be other than circular, for example, elliptical, rectangular, square, polygonal, etc. The first coil body 2 is not limited to a contrast marker.

The cross-sectional shapes of the first core 8a and the second core 8b may be other than circular, and may be, for example, elliptical, rectangular, square, polygonal, etc. The cross-sectional shapes of the first core 8a and the second core 8b may also change in the axial direction. Furthermore, the configuration is not limited to joining the base end surface 8c of the first core 8a to the tip end surface of the second core 8b by welding. For example, the base end of the first core 8a and the tip end of the second core 8b may be positioned inside a tubular body and joined. The core unit 8 is not limited to a configuration having the first core 8a and the second core 8b joined to each other. The first core 8a and the second core 8b may be integrally formed from the same material.

The first coating layer 10a, the second coating layer 10b, the third coating layer 10c, and the fourth coating layer 10d may each have a single-layer structure or a laminated structure. The coating portion 10 is not limited to a structure divided into the first coating layer 10a, the second coating layer 10b, the third coating layer 10c, and the fourth coating layer 10d in the axial direction.

The fixing portion 9 is not limited to a configuration having the first fixing member 9a, the second fixing member 9b, and the third fixing member 9c. For example, the base end of the first coil body 2 and the tip end of the second coil body 6 may be joined to each other without providing the second fixing member 9b.

The outer surface of the wires 3 that form the first coil body 2 may have grooves 4 in a spiral shape other than a double spiral; for example, it may have grooves 4 in a single spiral shape, or grooves 4 in a triple or more spiral shape. When the first coil body 2 is formed from two or more wires 3, it may be configured so that only some of the wires 3 that form the first coil body 2 have at least one groove 4, rather than each of the wires 3. Groove portions 5 may be provided not only in the first coil body 2 but also in the second coil body 6.

Each groove 4 forming the groove portion 5 may be arranged in a ring shape rather than a spiral shape. For example, as shown in the modified example in Figure 4, the outer surface of the wire 3 forming the first coil body 2 may have multiple ring-shaped grooves 4 arranged at a predetermined pitch P in the axial direction of the wire 3 itself. In Figure 4, only one groove 4 is marked with a reference symbol.

The grooves 4 forming the groove portion 5 may be formed in a shape other than a spiral or annular shape. For example, as shown in the modified example in Figure 5, the grooves 4 forming the groove portion 5 may extend along the axial direction of the guidewire 1 (the direction along the axis O). In this case, each groove 4 may be formed only in a portion of the first coil body 2 located radially outward of the guidewire 1 (the radially outward of the axis O). In Figure 5, only one groove 4 is marked with a reference symbol. This configuration allows the groove portion 5 to be easily formed by an irradiation step in which at least one groove 4 is formed by irradiating the first coil body 2 (at least one strand 3 forming the first coil body 2) with laser light. Note that the irradiation step may be performed with the first coating layer 10a in place. In this case, the wavelength of the laser light is set to a wavelength that is easily absorbed by the first coil body 2, such as a metal, but is difficult to absorb by the first coating layer 10a, such as a non-metal.

Each groove 4 forming the groove portion 5 may extend in the axial direction of the guidewire 1, or in another direction. Each groove 4 forming the groove portion 5 may be provided in a portion of the first coil body 2 located radially inside the guidewire 1, in addition to or instead of a portion of the first coil body 2 located radially outside the guidewire 1. The groove portion 5 may be provided on one or both sides of at least one of the wires 3 itself in the axial direction of the guidewire 1.

Instead of being provided around the entire circumference of the guidewire 1 on the first coil body 2, the groove portion 5 may be provided not on the portion of the first coil body 2 aligned in a first direction (the up-and-down direction in FIG. 6 or 7) perpendicular to the axial direction of the guidewire 1, but on the portion of the first coil body 2 aligned in a second direction (the direction perpendicular to the plane of the paper in FIG. 6 or 7) perpendicular to both the axial direction and the first direction of the guidewire 1, as in the modified example shown in FIG. 6 or 7. In FIG. 6 or 7, only one groove 4 is denoted by a reference symbol. This configuration ensures the pushability of the first coil body 2 while increasing flexibility in a specific direction.

The groove portions 5 provided in the portions of the first coil body 2 aligned in the second direction may be provided on only both sides of at least one wire 3 in the axial direction of the guide wire 1, as in the modified example shown in Figure 6, for example. Alternatively, the groove portions 5 provided in the portions of the first coil body 2 aligned in the second direction may be provided on only one side of at least one wire 3 in the axial direction of the guide wire 1. This configuration ensures the pushability of the first coil body 2 while increasing its flexibility in the first direction.

The groove portions 5 provided in the portions of the first coil body 2 aligned in the second direction may be provided on only both or only one side of at least one of the strands 3 in the second direction, as in the modified example shown in Figure 7. This configuration ensures the pushability of the first coil body 2 while increasing its flexibility in the second direction.

The groove portion 5 is not limited to a configuration in which the width W, depth D, and pitch P of the grooves 4 are all constant. For example, the groove portion 5 may be configured so that the pitch P of the grooves 4 decreases from the base end to the tip end of the guidewire 1, or the width W or depth D of the grooves 4 increases from the base end to the tip end of the guidewire 1. This configuration efficiently increases the flexibility of the tip portion 1a of the guidewire 1 while ensuring the pushability of the first coil body 2.

As shown in FIG. 8 , the guidewire 1 according to the second embodiment of the present disclosure has a core portion 8, a coil body 2, and a covering portion 10. The covering portion 10 has an inner covering layer 10e and an outer covering layer 10f. The guidewire 1 according to this embodiment is suitable for insertion into blood vessels in the abdomen, head, etc.

The core portion 8 is linear and extends axially around the axis O, and is made of a metal material such as a superelastic alloy, such as a nickel (Ni)-titanium (Ti) alloy. The distal end of the core portion 8 has a radial dimension that decreases from the base end toward the distal end.

The coil body 2 is formed in a spiral shape centered on the axis O using at least one wire 3. The coil body 2 forms a contrast marker. The coil body 2 is arranged so that its inner surface contacts the outer surface of the tip of the core portion 8. The coil body 2 forms only the tip portion 1a of the guide wire 1. However, the coil body 2 may also form portions of the guide wire 1 other than the tip portion 1a. In the illustrated example, the coil body 2 forms a single spiral, but it may also be configured to form a double spiral or multiple spiral.

The inner coating layer 10e covers the entire core portion 8 and coil body 2. The inner coating layer 10e is formed, for example, from a resin. The outer coating layer 10f covers the entire inner coating layer 10e. The outer coating layer 10f is formed, for example, from a hydrophilic polymer.

At least one wire 3 forming the coil body 2 has at least one groove 4 (not shown). In other words, the coil body 2 has a groove portion 5. The groove portion 5 is provided in the same manner as in the first embodiment.

As with the first embodiment, this embodiment can enhance flexibility while ensuring the X-ray contrast of the coil body 2. Furthermore, by appropriately setting the width W, depth D, and pitch P of the grooves 4 in the groove portion 5, the flexibility of the distal end 1a of the guidewire 1 can be easily adjusted.

As with the first embodiment, the groove portion 5 can be modified in various ways, including the modifications shown in Figures 4 to 7.

As shown in FIG. 9 , the guidewire 1 according to the third embodiment of the present disclosure includes a coil body 2, a core wire 11, a safety wire 12, a distal end member 13, and a proximal end member 14. The coil body 2 forms the portion of the guidewire 1 that extends from the distal end 1a to the proximal end 1b. The guidewire 1 according to this embodiment is suitable for angiography, for example. The distal end 1a of the guidewire 1 is curved in a J-shape in its natural state before elastic deformation.

The distal end member 13 is fixed to the distal end of the coil body 2. The proximal end member 14 is fixed to the proximal end of the coil body 2. The core wire 11 extends axially radially inside the coil body 2, strengthening the stiffness of the coil body 2. The distal end of the core wire 11 is tapered from the proximal end toward the distal end. The proximal end of the core wire 11 is connected to the proximal end member 14. The safety wire 12 extends axially radially inside the coil body 2, connects to the distal end member 13 at its distal end, and connects to the proximal end member 14 at its proximal end, maintaining the overall shape of the guidewire 1.

The coil body 2 is formed from at least one wire 3 in a spiral shape centered on the axis O. At least one wire 3 forming the coil body 2 has at least one groove 4 (not shown). In other words, the coil body 2 has a groove portion 5. The groove portion 5 is provided in the same manner as in the first embodiment. In the illustrated example, the coil body 2 is in a single spiral shape, but it may also be in a double spiral or multiple spiral shape.

According to this embodiment, the flexibility of the coil body 2 can be easily increased. Furthermore, by appropriately setting the width W, depth D, and pitch P of the grooves 4 in the groove portion 5, the flexibility of the distal end 1a of the guidewire 1 can be easily adjusted.

As with the first embodiment, the groove portion 5 can be modified in various ways, including the modifications shown in Figures 4 to 7.

The core wire 11 is not limited to being tapered. The core wire 11 is not limited to being connected to the base end member 14. For example, the base end of the core wire 11 may be fixed to the coil body 2 via brazing material or the like. The safety wire 12 is not limited to being connected to the base end member 14. For example, the base end of the safety wire 12 may be fixed to the coil body 2 via brazing material or the like.

As shown in FIG. 10, the guidewire 1 according to the fourth embodiment of the present disclosure has a configuration similar to that of the third embodiment, except that the distal end portion 1a of the guidewire 1 is linear in its natural state. This embodiment also achieves the same effects as the third embodiment.

This disclosure is not limited to the above-described embodiments, and various modifications are possible without departing from the spirit of the present disclosure.

Therefore, the guidewire 1 according to the above-described embodiment can be modified in various ways as long as it has at least one wire 3 forming the coil body 2, and the at least one wire 3 has at least one groove 4.

It is preferable that the guidewire 1 according to the above-described embodiment is a guidewire 1 in which at least one groove 4 is provided only in the distal end portion 1a of the guidewire 1.

In the guidewire 1 according to the above-described embodiment, it is preferable that at least one groove 4 has a pitch P that decreases from the base end toward the tip end of the guidewire 1.

The guidewire 1 according to the above-described embodiment is preferably a guidewire 1 in which the width W or depth D of at least one groove 4 increases from the base end toward the tip end of the guidewire 1.

It is preferable that the guide wire 1 according to the above-described embodiment is a guide wire 1 in which at least one wire 3 forms a contrast marker.

In the guide wire 1 according to the above-described embodiment, it is preferable that at least one wire 3 forms the distal end 1a of the guide wire 1 or a portion extending from the distal end 1a to the proximal end 1b of the guide wire 1.

The guide wire 1 according to the above-described embodiment is preferably a guide wire 1 in which at least one groove 4 is provided in at least one wire 3 over the entire circumference of the guide wire 1.

It is also preferable that the guide wire 1 according to the above-described embodiment is a guide wire 1 in which at least one groove 4 is not provided in a portion of at least one wire 3 aligned in a first direction perpendicular to the axial direction of the guide wire 1, but is provided in a portion of at least one wire 3 aligned in a second direction perpendicular to both the axial direction of the guide wire 1 and the first direction.

In this case, the guide wire 1 is preferably a guide wire 1 in which at least one groove 4 is provided on both sides or only one side of at least one strand 3 itself in the second direction. It is also preferable that the guide wire 1 is a guide wire 1 in which at least one groove 4 is provided on both sides or only one side of at least one strand 3 itself in the axial direction of the guide wire 1.

The guidewire 1 according to the above-described embodiment is preferably a guidewire 1 in which at least one groove 4 extends in the axial direction of the guidewire 1. In this case, the guidewire 1 is preferably a guidewire 1 in which at least one groove 4 is provided only in a portion of at least one wire 3 that is located radially outward of the guidewire 1.

It is also preferable that the guide wire 1 according to the above-described embodiment is a guide wire 1 in which at least one groove 4 is provided in a spiral or annular shape on the outer peripheral surface of at least one wire 3 itself.

The method for manufacturing the guidewire 1 according to the above-described embodiment preferably includes an irradiation step in which at least one groove 4 is formed by irradiating laser light onto at least one wire 3 in a state in which the coil body 2 is formed.

1 Guidewire 1a Distal end portion of guidewire 1b Proximal end portion of guidewire 2 First coil body (coil body)
3 Wire 4 Groove 4a Side surface 4b Bottom surface 5 Groove portion 6 Second coil body 7 Coil portion 8 Core portion 8a First core 8b Second core 8c Base end surface of first core 9 Fixing portion 9a First fixing member 9b Second fixing member 9c Third fixing member 10 Covering portion 10a First covering layer 10b Second covering layer 10c Third covering layer 10d Fourth covering layer 10e Inner covering layer 10f Outer covering layer 11 Core wire 12 Safety wire 13 Distal end member 14 Base end member D Depth O Axis P Pitch W Width

Claims (7)

A guidewire having at least one wire forming a coil body, the at least one wire having at least one groove,
A guide wire in which the at least one groove is not provided in a portion of the at least one wire aligned in a first direction perpendicular to the axial direction of the guide wire, but is provided in a portion of the at least one wire aligned in a second direction perpendicular to both the axial direction of the guide wire and the first direction. The guide wire according to claim 1 , wherein the at least one groove is provided on both or only one surface of the at least one strand itself in the second direction. The guidewire according to claim 1 , wherein the at least one groove is provided on both sides or only one side of the at least one strand itself in the axial direction of the guidewire. A guidewire having at least one wire forming a coil body, the at least one wire having at least one groove,
The at least one groove extends axially along the guidewire. The guidewire according to claim 4 , wherein the at least one groove is provided only in a portion of the at least one strand positioned radially outward of the guidewire. The guidewire according to claim 1 , wherein the at least one groove is provided in a spiral or annular shape on the outer circumferential surface of the at least one strand itself. A method for manufacturing a guide wire according to any one of claims 1 to 5 , further comprising an irradiation step of forming the at least one groove by irradiating the at least one wire with laser light in a state in which the coil body is formed.