JP2004208704A - Medical guidewire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a guidewire, improved in operability, and having the tip part which will not cause buckling, is flexible and has good operability. <P>SOLUTION: This guidewire 10 is composed of: a core wire 11 having an operating part 12 and a working part 13 gradually decreased in thickness from one end of the operation part to the tip; an imaging coil 15 provided extending from the tip of the working part at the working part; and a non-imaging coil 14 provided extending from the end part of the imaging coil. The imaging coil 15 is formed by winding a metal wire covered with synthetic resin at a gap of 0.01 to 0.05 mm between the adjacent windings. The non-imaging coil 14 is formed by winding a metal wire covered with synthetic resin at a gap of 0 to 0.05 mm between the adjacent windings. Further, both ends of the respective coils are fixed to the working part. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a medical guidewire, particularly to a medical guidewire used for percutaneous transluminal coronary angioplasty (PTCA) and the like.
[0002]
[Prior art]
[Patent Document 1] JP-A-60-63065
[Patent Document 2] JP-A-4-108456
[Patent Document 3] JP-A-6-63150
[Patent Document 4] JP-A-10-33689 (Japanese Patent No. 3181533)
Conventionally, catheters have been used for infusion, blood access for dialysis, and the like. However, with the recent improvement in radiation medical technology, it has become possible to guide a catheter directly to an affected part through a blood vessel, and it is used as a medical device for directly examining or treating an affected part. Then, a guide wire is inserted prior to the catheter to guide the catheter to a target site in a blood vessel. Since the guide wire must be inserted along the curved blood vessel in this way, it can be easily bent even in a meandering blood vessel without damaging the blood vessel wall, and can be inserted into a complicated blood vessel branch. Flexibility is required. Further, there is a need for a guidewire that is relatively rigid in the axial direction of the guidewire and does not easily buckle in the axial direction in order to be inserted deep inside the body.
[0003]
As shown in FIG. 3, such a guide wire has a body portion 101 having flexibility as a whole and having relatively high rigidity, and a relatively flexible distal end portion 102 as shown in FIG. A guidewire 100 is disclosed which is formed so as to be tapered from the main body 101 toward the distal end 102. Also, in such a guidewire, a coil made of a metal wire is attached to the outer periphery of the distal end so that the flexibility of the distal end is restored without buckling even if the distal end is bent. Known are those that have been made or those that use a shape memory alloy. Further, in Patent Document 2, a coil is wound around the entire metal core wire to provide rigidity in the axial direction and flexibility in the radial direction, and furthermore, densely at the base of the core wire, and at the tip of the core wire. A loosely wound coil gives a difference in rigidity and flexibility between a base portion and a distal end portion, and thereby discloses a guide wire having improved operability. Further, Patent Literature 3 discloses a guidewire in which the strength is further improved by winding the coil twice, and the operation is facilitated.
[0004]
In Patent Literature 4, in order to further improve operability, a base portion, a tip portion, and an intermediate portion connecting them are provided, and their hardness is reduced in the order of the base portion, the intermediate portion, and the tip portion. Discloses a guidewire divided into a plurality of sections provided in the guidewire.
[0005]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION An object of the present invention is to provide a guidewire having a flexible and operable distal end without buckling, with the object of improving the operability of a conventional guidewire.
[0006]
[Means for Solving the Problems]
A guide wire according to the present invention is a core wire having an operating portion, and an operating portion that is gradually narrowed from one end to the distal end of the operating portion, and from the distal end to the proximal end of the operating portion. And a second coil provided from an end of the first coil to a base end of the action portion, wherein the first coil and / or the second coil are The first coil is densely wound, the second coil is sparsely wound, and both ends of each coil are fixed to the working portion, while being formed by winding a metal wire coated with a synthetic resin. It is characterized by having. In such a guide wire, it is preferable that the distal end of the action portion has a flat plate shape (claim 2). Furthermore, it is preferable that the synthetic resin coating the first coil and / or the second coil is a hydrophilic polymer or a fluororesin (claim 3). Further, it is preferable that a gap between adjacent windings of the first coil is 0.01 to 0.05 mm and a gap between adjacent windings of the second coil is 0 to 0.05 mm. 4).
[0007]
In the method of manufacturing a guide wire according to the present invention (claim 5), the first coil and the second coil, which is a close coil, are inserted into the working portion of the core wire, both ends of the first coil are fixed, and the second coil is fixed. It is characterized in that both ends are pulled and fixed so that the length of the coil is at least 0.1 mm longer than the natural length.
[0008]
[Action and effect of the invention]
A guide wire according to the present invention (Claim 1) has a core wire having an operation portion that is gradually narrowed from one end to a tip of the operation portion, and the operation portion has two types of a first coil and a second coil having different windings. Since it has two coils, it has relatively moderate rigidity in the axial direction and flexibility in the radial direction. In particular, by providing the first coil sparsely wound on the distal end side in the action section leading the guide wire, the distal end side becomes more flexible, and the risk of piercing the blood vessel wall or the like is reduced. Further, by providing the second coil continuously and densely wound from the end of the first coil while having such a tip portion, the portion can have a certain degree of rigidity. Operability can be improved as a whole. Further, when the action portion has two levels of elasticity when it comes into contact with a blood vessel wall or the like, the possibility that the distal end side of the action portion buckles or damages the blood vessel wall is reduced. When operating a guide wire, the tip is usually shaped into a J-shape or angled shape, but by providing a flexible part between the shaping part and the operation unit, the shaping is performed. And the operability is also improved. In other words, it is possible to easily and reliably guide to the target site even in a complicatedly branched blood vessel.
[0009]
Further, when the tip of the action portion is flat (claim 2), since the tip has relatively flexibility in the up-down direction and rigidity in the left-right direction, the movement of the tip is easy to predict. Easy to handle the tip. Further, when the synthetic resin covering the first coil and the second coil is a hydrophilic polymer (claim 3), an action portion of a guide wire exhibiting lubricity when wet can be provided. Thereby, the friction between the surface of the working portion having irregularities due to the coil, the blood vessel wall, and the inner surface of the catheter can be reduced. In addition, the guide wire, before being inserted into the body, directly touches and clears the action section, but after insertion into the body, since the action section is operated with the operation section, it does not show lubricity before insertion into the body, Those that exhibit lubricity after insertion into the body are preferred. By using a hydrophilic polymer as a surface coating in this way, it is possible to obtain a working surface of a guide wire that does not normally exhibit lubricity but exhibits lubricity when wet. Therefore, operability before and after insertion into the body can be significantly improved. Furthermore, generally, when a synthetic resin is provided in a coil portion after assembling a core wire and a coil, the synthetic resin fixes a gap between coil wires, so that the flexibility of this portion is lost and operability is reduced. I do. However, in the guide wire of the present invention, since at least one of the first coil and the second coil is a coil formed of a metal wire coated with a synthetic resin in advance, the element wires of the coil are fixed in the coil. However, flexibility is sufficiently maintained. Therefore, operability is improved.
[0010]
When the distance between adjacent turns of the first coil is 0.01 to 0.05 mm and the distance between adjacent turns of the second coil is 0 to 0.05 mm (claim 4), It is possible to provide a preferable flexibility in the radial direction and a preferable rigidity in the axial direction at the located portion. Further, by changing the length, the flexibility and rigidity can be arbitrarily adjusted. If the gap between the windings of the first coil is larger than the maximum value in the above range, buckling may occur at the distal end. If the gap is less than the minimum value, the gap is not sufficient, and May have higher rigidity, and the tip may break through a blood vessel wall or the like. If the gap between the wires of the second coil is larger than 0.05 mm, the force cannot be transmitted to the distal end portion.
[0011]
In the method of manufacturing a guide wire according to the present invention (claim 5), the first coil is fixed to the working portion, and the both ends of the second coil are fixed to the working portion while being pulled. Since both ends are fixed while pulling the second coil in this manner, the size of the gap between the windings can be adjusted, and the second coil having preferable flexibility and rigidity can be provided. In particular, when the gap between the strands of the coil coated with the synthetic resin is not sufficient, the adjacent windings are stuck to each other, and there is a possibility that the flexibility may be deteriorated, which is preferable. By fixing the second coil in this way, the guide wire of the present invention can be manufactured.
[0012]
[Embodiment of the present invention]
Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a partial sectional view showing an embodiment of the guide wire of the present invention, and FIG. 2 is a front view of a core wire used for the guide wire of the present invention.
[0013]
A guide wire 10 shown in FIG. 1 includes a core wire 11 integrally formed of an operation portion 12 and an operation portion 13 extending from one end of the operation portion 12 to the distal end in a tapered manner, and a base end portion and a distal end portion of the operation portion. It is composed of a non-contrast coil 14 and a contrast coil 15 provided in order toward 17. The non-contrast coil 14 is a coil that transmits X-rays, and the contrast coil 15 is a coil that does not transmit X-rays. Both ends of each coil are fixed to the action section 13.
[0014]
The operation section 12 has a surface coated with a synthetic resin, so that friction with a blood vessel, a catheter, or the like can be reduced. Therefore, when sliding the guide wire, the blood vessel is not damaged and the operability is good. Further, by providing a biochemically stable synthetic resin layer, the effect on the body can be relatively reduced. As a material for the coating of such an operation unit, a hydrophilic polymer, a fluororesin, or the like is preferable, and polytetrafluoroethylene (PTFE) is particularly preferable. Since PTFE is stable, it does not melt even when inserted into the body, so that a guide wire having a smaller influence on the body can be obtained. In addition, since the guide wire 10 is operated by a fingertip at the base 16 of the operation unit 12, the base 16 is formed in a hemispherical shape so that the operation can be easily performed. This facilitates a fine operation for guiding to a complicatedly branched blood vessel or the like.
[0015]
The action section 13 is tapered from one end of the operation section 12 to the tip thereof. Thereby, the flexibility increases toward the tip side. Further, a non-contrast coil 14 and a contrast coil 15 are provided around the operation section 13. By providing the coils 14 and 15 in this manner, the working portion 13 can have rigidity in the axial direction of the guide wire 10 and can have flexibility and elasticity in the radial direction. Therefore, the operation inside the body is easy, and even if the tip bends during the operation, it can return to the original shape without buckling due to elastic force. Examples of the material of the core wire 11 include elastic stainless steel, nickel-titanium (Ni-Ti) alloy, nickel alloy, and cobalt alloy. Its total length is 0.6 to 3.0 m, preferably 1.5 to 2.0 m. The outer diameter W of the operating portion is 0.1 to 2.0 mm, and particularly preferably 0.2 to 0.5 mm. Further, the outer diameter V of the distal end portion 17 of the action portion is preferably 0.05 to 0.20 mm, particularly preferably 0.06 to 0.10 mm.
Further, the distal end portion 17 of the core wire may be pressed into a plate shape. By forming the distal end portion 17 in a plate shape in this manner, it is possible to provide a distal end having flexibility in the vertical direction and rigidity in the horizontal direction, and it is easy to predict the movement of the distal end and to perform the operation. In the present embodiment, the tapered portion is tapered from the operation portion to the distal end. However, the tapered connecting portion may be obtained and gradually tapered (see FIG. 2). Further, in the present embodiment, two coils are provided, but three or more coils may be provided.
[0016]
The non-contrast coil 14 is composed of a metal wire that is not contrasted by radiation and a synthetic resin layer that coats the metal wire, and is a close contact coil. The imaging coil 15 is composed of a metal wire that is imaged by radiation and a synthetic resin layer that coats the metal wire. Thereby, the friction with the blood vessel wall or the like can be reduced in the working portion where the coil is wound. Further, since the adjacent windings of the coil are not fixed by the coating, the elasticity of the coil can be maintained. As a material of such a synthetic resin layer, a hydrophilic polymer is preferable, and particularly, polyvinylpyrrolidone, cellulose, maleic anhydride, and n-vinyl lactam acrylic methacrylate (n-vinyl-lactam alkyl-methacrylate) are preferable. By using a hydrophilic polymer as the synthetic resin layer, it is possible to obtain a guide wire having a surface that usually has no lubricity and lubricity when wet, and is most preferable when the operation is performed inside and outside the body. In addition, by providing the imaging coil 15 on the distal end side, the distal end of the operating section 13 can be detected by radiation, and the distal end of the operating section 13 in the body can be guided to the target site.
[0017]
The non-contrast coil 14 is a close contact coil, and its inner diameter is slightly smaller than the outer diameter of the operation unit 12. Therefore, the tapered Z portion can be fitted to the action portion 13. The outer diameter of the non-contrast coil 14 is set to be substantially the same as that of the operation unit 12. For this reason, the entire guidewire has substantially the same diameter, and is less likely to be caught during operation. The non-contrast coil 14 is fixed at a Z portion and a Y portion, which is a point slightly longer than the natural length of the non-contrast coil 14 from the Z portion. The distance between adjacent windings is 0.01 to 0.05 mm. If it is less than 0.01 mm, it is too hard to pass through a complicatedly bent blood vessel, and if it is more than 0.05 mm, it becomes too flexible and operability decreases. Thereby, it is possible to obtain the working portion 13 having a preferable rigidity in the axial direction of the guide wire and a preferable flexibility in the radial direction. Further, since the coil is covered with the synthetic resin, it is possible to prevent the adjacent windings from sticking to each other. Further, by adjusting the gap and the flexibility thereof, a guide wire corresponding to a part to be examined can be obtained. Examples of the metal wire that is not contrasted by the radiation of the non-contrast coil 14 include the same wire stainless steel, nickel-titanium alloy, nickel alloy, cobalt alloy, and the like as the core described above.
[0018]
The contrast coil 15 is fixed at a Y portion to which one end of the non-contrast coil 14 is fixed and at an X portion which is a tip of the operation portion 13. The space between the adjacent windings is larger than the non-contrast coil 14 by 0.01 to 0.05 mm. In this way, by giving a change to the way in which the non-contrast coil 14 and the contrast coil 15 are wound, it is possible to give the action section a stepwise elasticity. For this reason, on the distal end side, flexibility is provided so that the distal end is directed in the other direction, and the working portion 13 as a whole is provided with moderate rigidity, thereby enabling more delicate movement as a whole. In addition, shaping is usually performed by bending the tip with a finger or the like to deform it into an angle shape or a J-shape. However, the shaping is easy because the tip is more flexible, and more complicated shaping is possible. That is, as a result, the operability can be significantly improved as a whole.
[0019]
The outer diameter of the contrast coil 15 is substantially the same as the outer diameter of the operation unit 11 like the non-contrast coil 14, and the contrast coil 15 is fixed at both ends X and Z in a natural length state. The tip 17 is provided in a hemispherical shape after being fixed. This makes it easier to guide the guide wire without damaging the blood vessel. Examples of the core wire of the non-contrast coil 15 include gold, platinum, silver, bismuth, tungsten, nickel, tantalum, iridium, titanium, rhodium, cobalt, and alloys thereof. The non-contrast coil 14 and the contrast coil 15 are fixed at the Y portion, but both coils may be entangled. Moreover, it may be fixed after being entangled. By tying both coils in this way, rigidity is created at that site, and operability is improved.
[0020]
Such a guidewire 10 can be manufactured as follows. A core wire 11 having an operation unit 12 and an operation unit that continuously extends from the operation unit 12 to the distal end in a tapered shape is prepared. The tip 17 of the core wire is formed into a plate shape by pressing. The contrast coil 15 and the non-contrast coil 14 are inserted into the core wire 11 and the ends of both coils are entangled. Next, one end of the contrast coil 15 is fixed at the X portion at the tip of the operation portion 13, and the other end of the contrast coil 15 is fixed together with one end of the non-contrast coil 14 in the natural length state at the Y portion of the operation portion 13. . Then, the other end of the non-contrast coil 14 is fixed at the Z portion of the working portion 13 while being pulled so as to be longer than its natural length by 0.1 mm or more. Then, it can be manufactured by polishing the tip portion 17 into a hemispherical shape, and polishing a fixed portion so as to smoothly rotate or roll on a plane over the entire length. By manufacturing in this manner, the gap between the second coils can be adjusted, and a guidewire having favorable flexibility in the radial direction can be manufactured. Also, the first coil may be similarly adjusted to a preferable gap while being pulled.
[0021]
In order to fix the coils 14 and 15 to the working portion 13 of the core wire 11, soft brazing such as soldering is usually used. A brazing material other than solder, for example, silver brazing, hard brazing or the like can also be used. As a fixing method other than brazing, for example, welding, pressure welding, and the like can be given.
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional view showing an embodiment of a guide wire according to the present invention.
FIG. 2 is a front view of a core wire used for the guide wire of the present invention.
FIG. 3 is a front view of a conventional guide wire.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Guide wire 11 Core wire 12 Operation part 13 Working part 14 Non-contrast coil 15 Contrast coil 16 Base 17 Tip

Claims (5)

An operating portion, and a core wire having an operating portion that is gradually narrowed from one end to the tip of the operating portion,
The operating portion includes a first coil provided from the distal end of the operating portion to the proximal end, and a second coil provided from the end of the first coil toward the proximal end of the operating portion. ,
The first coil and / or the second coil are configured by winding a metal wire coated with a synthetic resin,
The first coil is tightly wound, the second coil is loosely wound,
A guide wire in which both ends of each coil are fixed to the working portion. 2. The guidewire according to claim 1, wherein the distal end of the action section has a flat plate shape. The guide wire according to claim 1, wherein the synthetic resin covering the first coil and / or the second coil is a hydrophilic polymer or a fluororesin. The guide wire according to claim 1, wherein a gap between adjacent windings of the first coil is 0.01 to 0.05 mm, and a gap between adjacent windings of the second coil is 0 to 0.05 mm. . It is a manufacturing method of the guide wire of Claim 4, Comprising:
The first coil and the second coil, which is a close contact coil, are inserted into the action part of the core wire,
A method for manufacturing a guide wire in which both ends of a first coil are fixed and both ends of a second coil are fixed while being pulled such that the length of the coil is at least 0.1 mm longer than a natural length.

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