JP2014161705A - Guide wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a guide wire capable of securing a sufficient bond strength between a core shaft and a coil body, and simply and accurately forming a shape of the tip of the guide wire.SOLUTION: A guide wire includes a core shaft 20, a coil body 30 covering the core shaft 20, and a bonding part 50 for bonding the tip of the core shaft 20 and the tip of the coil body 30. The bonding part 50 is formed by fusing the tip of the core shaft 20, and the tip of the coil body 30 is covered with the bonding part 50; and thereby, it is possible to bond the core shaft 20 and the coil body 30 without using a brazing material, and to secure the contact area between the bonding part 50 and the coil body 30. As a result of this, it is possible to secure a sufficient bond strength between the core shaft 20 and the coil body 30. Since the coil body 30 is not fused to retain the tip shape, it is possible to simply and accurately form a shape of the tip of the guide wire 10.

Description

  The present invention relates to a guide wire inserted into a blood vessel.

  A guide wire for use in inserting a catheter into a blood vessel is known. When inserting a catheter, a guide wire is first inserted into the blood vessel and advanced to the vicinity of the lesion, and then the catheter is advanced along the guide wire. In this manner, various treatments are performed through the catheter with the catheter inserted to the vicinity of the lesioned part of the blood vessel.

  Blood vessels are soft and easily damaged organs. Therefore, the guide wire is required to have sufficient flexibility so as not to damage the blood vessel. In view of this, a coil body provided at the distal end portion of the guide wire to ensure flexibility at the distal end portion (so-called coil-type guide wire) is widely used. In such a coil-type guide wire, a coil body is provided so as to cover the core shaft, and the distal end portion of the core shaft and the distal end portion of the coil body are joined by a brazing material.

  In general, the brazing material has a property of easily causing electrolytic corrosion. Therefore, when the core shaft and the coil body are joined using the brazing material, the brazing material may be melted by electrolytic corrosion, and sufficient joining strength cannot be ensured. Then, the guide wire which joined both the front-end | tip part of a coil body and the front-end | tip part of a core shaft by welding, without using brazing material is proposed (patent document 1).

US Pat. No. 5,488,959

  However, the guide wire described in Patent Document 1 has a problem that it is difficult to accurately form the shape of the tip portion of the guide wire. That is, in the guide wire described in Patent Document 1, both the tip of the coil body and the tip of the core shaft are melted because the coil body and the core shaft are joined by welding. For this reason, there is a problem that the shape of the distal end portion of the guide wire is difficult to stabilize, and as a result, it is difficult to accurately form the shape of the distal end portion of the guide wire.

  The present invention has been made in response to the above-described problems of the prior art, and in a coil-type guide wire, the bonding strength between the core shaft and the coil body can be sufficiently ensured, and the guide An object of the present invention is to provide a technique capable of easily and accurately forming the shape of the tip of a wire.

  In order to solve the above-described problems, the guide wire of the present invention employs the following configuration. That is, the guide wire of the present invention includes a core shaft, a coil body that covers the core shaft, and a joint portion that joins the tip portion of the core shaft and the tip portion of the coil body, and the joint portion is the tip of the core shaft. The coil body is formed by melting the part, and the coil body is characterized in that the tip part is covered with the joint part.

  Such a guide wire of the present invention joins the tip of the core shaft and the tip of the coil body by melting the core shaft. By doing so, the tip of the core shaft and the tip of the coil body can be joined without using a brazing material that easily undergoes electrolytic corrosion. As a result, it is possible to sufficiently secure the bonding strength between the core shaft and the coil body.

  In the guide wire of the present invention, the core shaft is melted but the coil body is not melted, and the shape of the tip portion of the coil body is maintained. Therefore, compared with the case where both the core shaft and the coil body are melted by welding, the shape of the distal end portion of the guide wire can be easily stabilized. As a result, the shape of the distal end portion of the guide wire can be easily and accurately formed, so that the insertion property of the guide wire into the blood vessel can be improved.

  Furthermore, the front-end | tip part of a coil body is the state covered with the junction part. Therefore, it is possible to reliably join the core shaft and the coil body by ensuring a contact area between the joint portion and the coil body.

  In the above-described guide wire of the present invention, a joint may be provided at the tip of the coil body so as to wrap the wire of the coil body.

  If it carries out like this, the contact area of a junction part and a coil body can be enlarged more. As a result, the core shaft and the coil body can be more reliably joined.

  In the guide wire of the present invention described above, a joint is provided at the tip of the coil body so as to wrap the wire of the coil body, and further, the inner peripheral surface of the coil body and the outer peripheral surface of the core shaft are provided. It is good also as providing a junction part also in the clearance gap between them.

  Also in such a guide wire of the present invention, the core shaft and the coil body can be reliably joined by increasing the contact area between the joint portion and the coil body. In addition, since the gap between the inner peripheral surface of the coil body and the outer peripheral surface of the core shaft can be filled with the joint at the distal end portion of the coil body, the hardness at the distal end portion of the guide wire can be ensured. As a result, it is possible to provide a guide wire that can easily penetrate a portion (chronic complete occlusion, so-called CTO) in which a blood vessel is blocked by cholesterol or the like deposited on the inner wall of the blood vessel.

  In the above-described guide wire of the present invention, the core shaft may be formed of a material having a melting point lower than that of the coil body.

  If it carries out like this, when joining the front-end | tip of a core shaft and the front-end | tip of a coil body, it can avoid reliably that a coil body fuse | melts with a core shaft. As a result, the shape of the tip of the guide wire can be more easily and accurately formed.

  In the above-described guide wire of the present invention, the coil body may be formed of tungsten.

  Tungsten is a material that has radiopacity. Therefore, the position of the distal end portion of the guide wire in the blood vessel can be confirmed while viewing the X-ray fluoroscopic image. However, tungsten is a metal that is difficult to join with other metals. For this reason, when joining the coil body of tungsten and a core shaft, it is difficult to ensure sufficient joint strength. On the other hand, in the guide wire of the present invention, the tip of the tungsten coil body is covered by the joint portion, so even if the tungsten coil body is difficult to join with other metals, the core is reliably It can be joined to the shaft.

  In the above-described guide wire of the present invention, the core shaft may be formed of stainless steel. Stainless steel is a material that can be easily processed by heat. Therefore, it is possible to easily form the joint by using stainless steel as the material for the core shaft.

It is explanatory drawing which showed the structure of the guide wire of 1st Embodiment of this invention. It is explanatory drawing which showed the structure of the guide wire of 2nd Embodiment of this invention. It is explanatory drawing which showed the structure of the guide wire of 3rd Embodiment of this invention. It is explanatory drawing which showed the structure of the guide wire of 4th Embodiment of this invention. (A) is an overall view of the guide wire, and (b) is an enlarged view of the distal end portion of the guide wire. It is explanatory drawing which showed the structure of the guide wire of 5th Embodiment of this invention. (A) is an overall view of the guide wire, and (b) is an enlarged view of the distal end portion of the guide wire. It is explanatory drawing which showed the mode of the procedure using the guide wire of 5th Embodiment of this invention.

A. First embodiment:
Below, in order to clarify the content of the present invention described above, various embodiments of the guide wire of the present invention will be described.
FIG. 1 is an explanatory diagram showing the configuration of the guide wire of the first embodiment. The illustrated guide wire 10 includes a core shaft 20 and a coil body 30 provided so as to cover the distal end side of the core shaft 20. In the guide wire 10 illustrated in FIG. 1, stainless steel (SUS) is used as the material of the core shaft 10. Further, tungsten having radiopacity is used as the material of the coil body 30, so that the position of the distal end portion of the guide wire in the blood vessel can be confirmed by an X-ray fluoroscopic image. Yes.

  The core shaft 20 includes a proximal end portion 22, a distal end portion 24 having a smaller diameter than the proximal end portion 22, and a tapered portion 26 that connects the proximal end portion 22 and the distal end portion 24. In FIG. 1, a part of the base end portion 22 is not shown.

  The shape of the core shaft 20 is not limited to the shape illustrated in FIG. 1, and for example, the diameter of the core shaft may be constant. However, as in this embodiment, the core shaft 20 has a shape that decreases in diameter toward the tip, thereby ensuring the flexibility of the tip of the guide wire 10 and the rigidity of the guide wire 10 on the rear end side ( That is, it is possible to ensure supportability when carrying a catheter or the like.

  The rear end portion of the coil body 30 is brazed to the core shaft 20. In the present embodiment, the rear end portion of the coil body 30 is joined to the boundary portion between the base end portion 22 and the taper portion 26 of the core shaft 20 by the brazing material 40. Moreover, in the guide wire 10 of this embodiment, the front-end | tip part of the coil body 30 and the front-end | tip part of the core shaft 20 are joined as follows. That is, the tip end portion of the core shaft 20 and the coil body are covered by melting the tip end portion of the core shaft 20 and covering the outer peripheral surface of the tip end portion of the coil body 30 with the melted core shaft (hereinafter referred to as the joint portion 50). 30 tip portions are joined.

  Thus, the guide wire 10 of the present embodiment melts the tip of the core shaft 20 to join the tip of the core shaft 20 and the tip of the coil body 30 without using a brazing material. The brazing material is generally a material that easily causes electrolytic corrosion. Therefore, it is possible to sufficiently secure the bonding strength between the core shaft 20 and the coil body 30 by bonding the core shaft 20 and the coil body 30 without using such a material.

  In the guide wire 10 of the present embodiment, the core shaft 20 is melted, but the coil body 30 is not melted, and the shape of the tip portion of the coil body 30 is maintained. Therefore, the shape of the tip portion of the guide wire 10 can be stabilized as compared with the case where both the core shaft and the coil body are melted by welding. As a result, the shape of the distal end portion of the guide wire 10 can be easily and accurately formed, so that the insertion property of the guide wire into the blood vessel can be improved.

  Furthermore, in the guide wire 10 of the present embodiment, the distal end portion of the coil body 30 is covered with the joint portion 50. Therefore, a sufficient contact area between the joint portion 50 and the coil body is ensured, so that the core shaft and the coil body can be more reliably joined.

  Here, in general, when tungsten is used as the material of the coil body 30, there is a problem that it is difficult to ensure sufficient bonding strength because it is difficult to bond tungsten to another metal. In this respect, in the guide wire 10 of this embodiment, as described above, the tip portion of the coil body 30 is covered with the joint portion 50 formed by melting the core shaft 20, so that the joint with other metals is not performed. Even a difficult coil body 30 made of tungsten can be reliably joined to the core shaft 20.

  In addition, in the guide wire 10 of this embodiment, the core shaft 20 is formed of stainless steel (SUS). Since stainless steel (SUS) is a material that can be easily processed by heat, using the stainless steel as the material of the core shaft 20 makes it possible to easily form the joint 50.

  In addition, in the guide wire 10 of this embodiment, the material of the core shaft 20 (stainless steel in this embodiment) is formed of a material having a lower melting point than the material of the coil body 30 (tungsten in this embodiment). ing. For this reason, when joining the front-end | tip of the core shaft 20 and the front-end | tip of the coil body 30, it can avoid reliably that the coil body 30 fuse | melts with the core shaft 20. FIG. As a result, the shape of the tip of the guide wire can be formed more easily and accurately.

  There are other related embodiments in the first embodiment described above. In the following, other embodiments will be briefly described. In the following description, the same components as those of the guide wire 10 of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

B. Second embodiment:
FIG. 2 is an explanatory view showing the configuration of the guide wire 12 of the second embodiment. The illustrated guide wire 12 of the present embodiment is different from the above-described guide wire 10 of the first embodiment in that the joining portion 52 covers the distal end portion of the coil body 32. That is, in the guide wire 12 of the present embodiment, the joint portion 52 is provided in such a manner as to wrap around the wire at the distal end portion of the coil body 32.
In the guide wire 12 of the present embodiment, the winding pitch of the coil body 32 is set so that the joining portion 52 can easily penetrate between the strands of the coil body 32. It is set larger than the winding pitch of the coil body 30 (see FIG. 1).

  In such a guide wire 12 of the present embodiment, the contact area between the joint 52 and the coil body 32 as compared with the case where the joint 50 is in contact with the outer peripheral surface of the coil body 30 (in the case of FIG. 1). Can be increased. As a result, the core shaft 20 and the coil body 32 can be more reliably joined.

C. Third embodiment:
FIG. 3 is an explanatory view showing the configuration of the guide wire 14 of the third embodiment. The illustrated guide wire 14 of the present embodiment is different from the guide wires 10 and 12 of the various embodiments described above in the manner in which the joint portion 54 covers the distal end portion of the coil body 32. That is, in the guide wire 14 of the present embodiment, not only the joint portion 54 wraps the wire at the tip end portion of the coil body 32, but also the joint portion 54 includes the inner peripheral surface of the coil body 32 and the outer periphery of the core shaft 20. It is also provided in the gap with the surface.

  In such a guide wire 14 of the present embodiment, similarly to the guide wire 12 (see FIG. 2) of the second embodiment described above, by ensuring a contact area between the joint portion 54 and the coil body 32, The core shaft 20 and the coil body 32 can be reliably joined. Further, since the joint portion 54 is also provided in the gap between the inner peripheral surface of the coil body 32 and the outer peripheral surface of the core shaft 20, the hardness at the distal end portion of the guide wire 14 can be increased. As a result, it can be suitably used as a guide wire 14 used in a procedure that penetrates chronic total occlusion (CTO).

D. Fourth embodiment:
FIG. 4 is an explanatory view showing the configuration of the guide wire 16 of the fourth embodiment. (A) is an overall view of the guide wire 16, and (b) is an enlarged view of the distal end of the guide wire 16.

  As shown in the drawing, the guide wire 16 of the present embodiment has a configuration that is very similar to the guide wire 14 of the third embodiment shown in FIG. 3, but the structure of the tip of the coil body 34 is a guide. It is different from the wire 14. That is, in the guide wire 16 of the present embodiment, the diameter of the wire of the coil body 34 decreases toward the tip in the portion covered with the joint portion 54.

  As described above, in the present embodiment, the diameter of the strand of the coil body 34 in the portion covered by the joint portion 54 decreases toward the tip, but the portion of the coil body 34 covered in the joint portion 54. The diameter of the wire may be smaller than the diameter of the wire of the coil body 34 in the other part and may be a constant diameter (not shown). However, the shape in which the diameter of the wire of the coil body 34 decreases toward the tip as in the present embodiment has an advantage that it is easy to manufacture for processing reasons.

  In the guide wire 16 of this embodiment, the joint portion 54 penetrates between the strands of the coil body 34 because the diameter of the strand of the coil body 34 in the portion covered by the joint portion 54 is set small. It has become easier. Accordingly, it is possible to facilitate the joining operation of the core shaft 20 and the coil body 34 by the joining portion 54.

E. Fifth embodiment:
FIG. 5 is an explanatory view showing the configuration of the guide wire 18 of the fifth embodiment. (A) is an overall view of the guide wire 18, and (b) is an enlarged view of the tip of the guide wire 18.

  As shown in the drawing, the guide wire 18 of the present embodiment has a configuration that is very similar to the guide wire 14 of the third embodiment shown in FIG. 3, but the structure of the tip of the coil body 36 is a guide. It is different from the wire 14. That is, in the guide wire 18 of the present embodiment, the outer diameter of the coil body 36 decreases toward the tip.

  FIG. 6 is an explanatory view showing a state of the procedure using the guide wire 18 of the fifth embodiment. For comparison, a state when the guide wire 14 of the third embodiment shown in FIG. 3 is inserted into a thin blood vessel is shown for comparison, and (b) shows the guide of the present embodiment. The state when the wire 18 is inserted into a thin blood vessel is shown.

  As shown in FIG. 6A, in the guide wire 14 of the third embodiment, the joint portion 54 has a substantially cylindrical shape. Therefore, when the guide wire 14 is inserted into a thin blood vessel, the entire side surface of the joint portion 50 comes into contact with the inner wall of the blood vessel. When the guide wire 14 is moved in this state, the joint portion 54 receives sliding resistance.

  Also in the guide wire 18 of the present embodiment shown in FIG. 6B, the joint 56 receives sliding resistance from the inner wall of the blood vessel. However, since the joint portion 56 has a substantially conical shape, when the guide wire 18 is inserted into a thin blood vessel, the contact area between the side surface of the joint portion 56 and the blood vessel inner wall can be made relatively small. As a result, the sliding resistance received from the inner wall of the blood vessel can be reduced, so that the bonding portion 56 and the coil body 36 are securely fixed even in a situation where the bonding portion 56 receives the sliding resistance. It becomes possible.

  As mentioned above, although the guide wire of various embodiment was demonstrated, this invention is not restricted to said embodiment, In the range which does not deviate from the summary, it is possible to implement in various aspects. For example, in the guide wires of the various embodiments described above, it has been described that tungsten is used as the material of the coil body. However, the material of the coil body is not limited to tungsten. Moreover, in the guide wire of various embodiment mentioned above, it demonstrated that stainless steel (SUS) was used as a material of the core shaft 20. FIG. However, the material of the core shaft 20 is not limited to stainless steel (SUS).

  In the guidewires of the various embodiments described above, it has been described that the rear end portion of the coil body and the core shaft are joined using a brazing material. However, the coil body and the core shaft may be joined to the rear end portion of the coil body by melting the core shaft in the same manner as the front end portion (not shown). In this way, the core shaft and the coil body can be joined at a plurality of locations without using a brazing material, so that the joint strength between them can be further improved.

10, 12, 14, 16, 18 ... guide wire,
20 ... Core shaft,
22: proximal end,
24 ... tip part,
26 ... taper part,
30, 32, 34, 36 ... coil bodies,
40 ... brazing material,
50, 52, 54, 56 ... joints

Claims (6)

A core shaft;
A coil body covering the core shaft;
A joint that joins the tip of the core shaft and the tip of the coil body;
The joint is formed by melting the tip of the core shaft,
The coil body is a guide wire whose tip is covered with the joint. The guide wire according to claim 1, wherein
The joint portion is a guide wire provided so as to wrap the element wire of the coil body at a distal end portion of the coil body. A guide wire according to claim 2,
The joint is a guide wire that is also provided in a gap between the inner peripheral surface of the coil body and the outer peripheral surface of the core shaft. A guide wire according to any one of claims 1 to 3,
The guide wire characterized in that the melting point of the core shaft is lower than the melting point of the coil body. A guide wire according to any one of claims 1 to 4,
The guide wire, wherein the coil body is made of tungsten. The guide wire according to claim 5, wherein
The guide wire, wherein the core shaft is made of stainless steel.