JP4332340B2 - Medical guidewire - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a medical guide wire, and more particularly to a medical guide wire 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)
[Patent Document 5]
JP 4-25024
Conventionally, catheters have been used for infusion and blood access for dialysis. However, with the recent improvement in radiological medical technology, it has become possible to guide the catheter directly to the affected area through the blood vessel, and it is used as a medical device for directly examining or treating the affected area. The guide wire is inserted in advance of the catheter to guide the catheter to a target site in the blood vessel. In this way, the guide wire must be inserted along the bent blood vessel, so that it can be easily bent even in meandering blood vessels without damaging the blood vessel wall, and can be inserted into complicated blood vessel branches. Flexibility is required. Furthermore, a guide wire that is relatively rigid in the axial direction of the guide wire and that does not easily buckle in the axial direction is required for insertion deep into the body.
[0003]
As such a guide wire, as shown in FIG. 3, Patent Document 1 has flexibility as a whole, and has a relatively rigid main body 101 and a relatively flexible tip 102. A guide wire 100 is disclosed which is formed so as to become tapered from the main body 101 toward the distal end 102. Moreover, in such a guide wire, a coil made of a metal wire is attached to the outer periphery of the distal end portion so that the flexibility of the distal end portion is not impaired and even if the distal end is bent, it can be restored without buckling. And those using a shape memory alloy are known. In Patent Document 2, the coil is wound around the entire metal core wire to provide rigidity in the axial direction and flexibility in the radial direction, and to the base of the core wire, and to the sparse end of the core wire. A guide wire is disclosed in which a difference in rigidity and flexibility is provided between a base portion and a distal end portion by winding a coil on the base portion, thereby improving operability. Furthermore, Patent Document 3 discloses a guide wire that is further improved in strength by winding a coil twice to facilitate operation.
[0004]
In Patent Document 4, in order to further improve the operability, it has a base end portion, a tip end portion, and an intermediate portion connecting them, and their hardness decreases in the order of the base end portion, the intermediate portion, and the tip end portion. Discloses a guide wire divided into a plurality of sections.
[0005]
[Problems to be solved by the invention]
An object of the present invention is to provide a guide wire having a distal end portion that is flexible and has good operability without buckling, with the object of improving the operability of the conventional guide wire.
[0006]
[Means for Solving the Problems]
The medical guide wire of the present invention (Claim 1) includes a core wire having an operation portion, an action portion that is gradually narrowed from one end to the tip of the operation portion, and a base portion from the tip of the action portion to the action portion. A contrast coil provided toward the end and a non-contrast coil provided from the end of the contrast coil toward the proximal end of the action portion. The contrast coil has a natural length between the windings. The non-contrast coil is a close contact coil, the outer diameters of the contrast coil and the non-contrast coil are substantially the same as the outer diameter of the operation unit, and the contrast coil and the non-contrast coil are made of polyvinyl. By winding a metal wire coated with a synthetic resin of any hydrophilic polymer selected from the group consisting of pyrrolidone, cellulose, maleic anhydride, and n-vinyl lactam acrylic methacrylate Each end of each coil is fixed to the action portion, and the base end of the contrast coil and the tip of the non-contrast coil are entangled and fixed. Pulled so as to be longer by 0.1 mm or more and fixed so that the distance between the windings is 0.01 to 0.05 mm. Between the fixed windings of the contrast coil is between the fixed windings of the non-contrast coil It is characterized by being larger. In such a guide wire, it is preferable that the tip of the action portion is flat.
[0007]
In the guide wire manufacturing method according to the present invention (Claim 3) , the contrast coil and the non-contrast coil , which is a contact coil, are inserted into the acting portion of the core wire, both ends of the contrast coil are fixed, and both ends of the non-contrast coil are fixed. The coil is fixed while being pulled so that the length of the coil is at least 0.1 mm longer than the natural length.
[0008]
[Operation and effect of the invention]
The guide wire of the present invention (Claim 1) includes a core wire having an action portion that is gradually narrowed from one end to the tip of the operation portion, and two kinds of contrast coils that are wound differently in the action portion, non-contrast Since it has a coil, it is relatively moderately rigid in the axial direction and flexible in the radial direction. In particular, by providing a contrast coil wound more sparsely on the distal end side in the action portion leading the guide wire, the distal end side becomes more flexible, and the risk of breaking through a blood vessel wall or the like is reduced. Further, by providing a non-contrast coil that is continuously wound tightly from the end of the contrast coil while having such a tip, it is possible to give the part a certain degree of rigidity, so that the entire action part As a result, operability can be improved. Further, when the action part is in contact with the blood vessel wall or the like, the action part exhibits two-stage elasticity, and thus the possibility that the distal end side of the action part is buckled or the blood vessel wall is damaged is reduced. When operating a guide wire, the tip is usually deformed into a J shape or an angle shape, but it is shaped by providing a flexible part between the shaping part and the operation part. The operability is also improved. That is, it is possible to easily and surely guide to the target site even in a complicatedly branched blood vessel.
Further, since the synthetic resin that coats the contrast coil and the non-contrast coil is a synthetic resin of any hydrophilic polymer selected from the group consisting of polyvinyl pyrrolidone, cellulose, maleic anhydride, and n-vinyl lactam acrylic methacrylate. An action portion of a guide wire that exhibits lubricity when wet can be provided. Thereby, the friction between the surface of the action part with unevenness by the coil and the blood vessel wall or the catheter inner surface can be reduced. The guide wire is shaped by directly touching the action part before being inserted into the body, whereas the action part is operated by the operation part after being inserted into the body. For this reason, it is preferable that the material does not exhibit lubricity before insertion into the body and exhibits lubricity after insertion into the body. Thus, the use of a hydrophilic polymer as a coating on the surface does not normally exhibit lubricity and lubricity when wet. The action part surface of the guide wire which shows can be obtained. And operability before and after insertion in the body can be remarkably improved.
Furthermore, generally, when a synthetic resin is provided on the coil part after assembling the core wire and the coil, the synthetic resin fixes the coil wires to each other, so the flexibility of this part is lost and the operability is reduced. To do. However, in the guide wire of the present invention, the contrast coil has a natural length and a gap between the windings, and the non-contrast coil is fixed by being pulled so as to be longer than the natural length by 0.1 mm or more. It is a close contact coil fixed so as to be 0.01 to 0.05 mm, and the space between the fixed non-contrast coil windings is larger than the space between the fixed first coil windings. The coil wires are not in contact with each other, the coil wires are not fixed, flexibility is sufficiently maintained, and operability is high. Further, it is possible to give a preferable flexibility in the radial direction and a preferable rigidity in the axial direction at the respective positions where the coils are located. Moreover, the flexibility and rigidity can be arbitrarily adjusted by changing the length.
[0009]
In addition, when the tip of the action portion is flat (Claim 2), the tip portion of the action portion is relatively flexible in the vertical direction and rigid in the left-right direction. , Easier to handle the tip .
[0011]
In the guide wire manufacturing method of the present invention (Claim 3), the contrast coil is fixed to the action part, and the both ends of the non-contrast coil are pulled and fixed to the action part. Since both ends are fixed while pulling the non-contrast coil in this way, the dimension of the gap between the windings can be adjusted, and a non-contrast coil having favorable flexibility and rigidity can be provided. In particular, when there is not enough space between the strands of the coil coated with the synthetic resin, adjacent windings may be bonded to each other, which may reduce flexibility. Thus, the guide wire of the present invention can be manufactured by fixing the non-contrast coil .
[0012]
[Embodiments of the Invention]
Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a partial cross-sectional view showing an embodiment of a 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 formed by an operation portion 12 and an action portion 13 extending from one end of the operation portion 12 to a tip end in a tapered shape, and a base wire portion to a tip end portion of the action portion. It is comprised from the non-contrast coil 14 (2nd coil) and the contrast coil 15 (1st coil) provided in order toward 17. FIG. 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 portion 13.
[0014]
The operation unit 12 is coated with a synthetic resin on the surface thereof, whereby friction with a blood vessel or a catheter can be reduced. Therefore, when the guide wire is slid, the blood vessel is not damaged and the operability is good. Furthermore, by providing a biochemically stable synthetic resin layer, the influence on the body can be made relatively small. As a material for coating such an operation portion, 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 if it is inserted into the body, and a guide wire having a smaller influence on the body can be obtained. Further, since the guide wire 10 is operated by a fingertip at the base portion 16 of the operation portion 12, the base portion 16 is formed in a hemispherical shape so that the operation can be easily performed. As a result, a fine operation for guiding to a complicatedly branched blood vessel or the like is facilitated.
[0015]
The action part 13 is tapered from the end of the operation part 12 to the tip. Thereby, the flexibility increases as it becomes the tip side. Further, a non-contrast coil 14 and a contrast coil 15 are provided around the action portion 13. By providing the coils 14 and 15 as described above, the action 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, operation in the body is easy, and even when the tip is bent during the operation, it can return to its 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. The total length is 0.6 to 3.0 m, preferably 1.5 to 2.0 m. The outer diameter W is 0.1 to 2.0 mm in the operation part, and 0.2 to 0.5 mm is particularly preferable. Moreover, in the front-end | tip part 17 of an action part, the outer diameter V is 0.05-0.20 mm, and what is 0.06-0.10 mm especially is preferable.
Further, the tip 17 of the core wire may be pressed into a plate shape. Thus, by making the tip portion 17 into a plate shape, a tip that is flexible in the vertical direction and rigid in the left-right direction can be provided, the movement of the tip can be easily predicted, and the operation is easy to perform. In the present embodiment, the taper is thinned from the operation part to the tip, but the taper-shaped connection part may be obtained to be thinned in steps (see FIG. 2). Furthermore, although two coils are provided in this embodiment, 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 contrast coil 15 is composed of a metal wire that is contrasted by radiation and a synthetic resin layer that coats the metal wire. Thereby, in the action part by which the coil is wound, friction with a blood vessel wall etc. can be made small. Further, since the adjacent windings of the coil are not fixed by the coating, the elasticity as the coil can be maintained. As a material for such a synthetic resin layer, a hydrophilic polymer is preferable, and polyvinyl pyrrolidone, cellulose, maleic anhydride, and n-vinyl lactam acrylic methacrylate are particularly preferable. By using a hydrophilic polymer as the synthetic resin layer, it is most preferable when the surface does not usually have lubricity and a guide wire having lubricity when wet can be obtained, and the manipulation is performed inside and outside the body. Further, by providing the contrast coil 15 on the distal end side, the distal end of the action portion 13 can be detected by radiation, and the distal end of the action portion 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, it can be made to fit to the action part 13 by the taper-shaped Z part. Further, the outer diameter of the non-contrast coil 14 is set to be approximately the same as that of the operation unit 12. Therefore, the guide wire as a whole has substantially the same diameter and is less likely to get caught during operation. The non-contrast coil 14 is fixed at a Z part and a Y part that is slightly longer than the natural length of the non-contrast coil 14 from the Z part. The distance between the adjacent windings is 0.01 to 0.05 mm. When the thickness is less than 0.01 mm, the hardness is too high to pass through a complicatedly bent blood vessel, and when it is larger than 0.05 mm, the hardness becomes too soft and the operability is lowered. Thereby, the action part 13 which has preferable rigidity in the axial direction of a guide wire and has favorable flexibility in a radial direction can be obtained. Moreover, since the coil is covered with the synthetic resin, it is possible to prevent the adjacent windings from sticking to each other. Furthermore, the guide wire according to the site | part to examine can be obtained by adjusting a clearance gap and adjusting the flexibility. 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, and cobalt alloy as the above-described core.
[0018]
The contrast coil 15 is fixed at the Y portion where one end of the non-contrast coil 14 is fixed and the X portion which is the tip of the action portion 13. The space between the adjacent windings is larger than the non-contrast coil 14 and is wound at 0.01 to 0.05 mm. Thus, by giving a change to the winding method of the non-contrast coil 14 and the contrast coil 15, it is possible to give the action portion stepwise elasticity. Therefore, on the tip side, flexibility is provided so that the tip is directed in the other direction, and the action portion 13 as a whole is given a moderate rigidity, and as a whole, more delicate movement is possible. In addition, the tip is usually shaped by bending the tip with a finger or the like and deformed 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 remarkably 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. Moreover, after fixing the front-end | tip part 17, it is provided in the hemispherical shape. 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 they may be entangled. Moreover, you may fix after entangling. Entangling both coils in this way creates rigidity at the site and improves operability.
[0020]
Such a guide wire 10 can be manufactured as follows. A core wire 11 having an operation portion 12 and an action portion that continuously extends from the operation portion 12 to the tip thereof is prepared. The tip portion 17 of the core wire is formed into a plate shape by pressing. A contrast coil 15 and a 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 part at the tip of the action part 13, and the other end of the contrast coil 15 is fixed together with one end of the non-contrast coil 14 in a natural length state at the Y part of the action part 13. . Then, the other end of the non-contrast coil 14 is fixed at the Z portion of the action portion 13 while being pulled so as to be 0.1 mm or longer from its natural length. Next, the tip 17 can be polished into a hemispherical shape, and the portion fixed so as to smoothly rotate or roll on a flat surface over the entire length can be polished. By manufacturing in this way, the gap of the non-contrast coil 14 (second coil) can be adjusted, and a guide wire having favorable flexibility in the radial direction can be manufactured. Further, the contrast coil 15 (first coil) may be adjusted to a preferable gap while being similarly pulled.
[0021]
In order to fix the coils 14 and 15 to the action portion 13 of the core wire 11, usually, soft soldering such as soldering is used. A brazing material other than solder, such as silver brazing or hard brazing, can also be used. Examples of fixing methods other than brazing include welding and pressure welding.
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional view showing an embodiment of a guide wire of the present invention.
FIG. 2 is a front view of a core wire used in 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 Action part 14 Non-contrast coil 15 Contrast coil 16 Base part 17 Tip part

Claims (3)

A core wire having an operation part and an action part that gradually becomes thinner from one end to the tip of the operation part;
In the action part, a contrast coil provided from the tip of the action part toward the base end,
It consists of a non-contrast coil provided from the end of the contrast coil toward the base end of the action part,
The contrast coil has a natural length and a gap between windings,
The non-contrast coil is a contact coil;
The outer diameters of the contrast coil and the non-contrast coil are substantially the same as the outer diameter of the operation unit
The contrast coil and the non-contrast coil are wound with a metal wire coated with a synthetic resin of any hydrophilic polymer selected from the group consisting of polyvinyl pyrrolidone, cellulose, maleic anhydride, and n-vinyl lactam acrylic methacrylate. Composed of
Both ends of each coil are fixed to the action part, and the base end of the contrast coil and the tip of the non-contrast coil are entangled and fixed,
The non-contrast coil is fixed so that the distance between the windings becomes 0.01 to 0.05 mm by pulling it so that it is longer than the natural length by 0.1 mm or more.
The spacing between the fixed contrast coil windings is larger than between the fixed non-contrast coil windings,
Medical guide wire. The guide wire according to claim 1, wherein a distal end portion of the action portion has a flat plate shape. A method of manufacturing a guide wire according to claim 1,
Inserting the contrast coil and the non-contrast coil, which is a close contact coil, into the working part of the core wire,
A method of manufacturing a guide wire in which both ends of a contrast coil are fixed and both ends of a non-contrast coil are fixed while being pulled so that the length of the coil is at least 0.1 mm longer than the natural length.

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