JP2004249095A - Guide wire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To offer a guide wire in which while a tip part has flexibility to prevent the inner wall of a tubular organ from being injured, a sufficient push-ability is provided, and further, positioning of a balloon catheter by X-rays is easy. <P>SOLUTION: In the guide wire 10 consisting of a core wire 20 and a metal coil 30 mounted on its outer periphery of the tip part, the metal coil 30 consists of a first metal coil 31 of single-start winding, which is arranged on the leading edge side and consists of an X-ray impermeable material, and a second metal coil 32 of multiple-start winding which is arranged on this hand side and consists of a higher X-ray permeable material than the first metal coil 31, and the contiguous wire rods of the second metal coil 32 are tightly stuck and rolled each other. It is preferred that the contiguous wire rods of the first metal coil 31 are rolled each other so as to have a space of at most its wire diameter. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  The present invention relates to a guidewire used to guide the distal end of a catheter to a target site when inserting the catheter into a tubular organ of a human body such as a blood vessel, a ureter, a bile duct, and a trachea.

  In recent years, for examination and treatment of tubular organs of the human body such as blood vessels, ureters, bile ducts, and trachea, a catheter is inserted to administer a drug such as a contrast agent, or a part of the tissue is collected with forceps or the like through the catheter. Or that is being done. In addition, for example, as a method of treating a stenotic part of a blood vessel such as a heart, it is also known to use a so-called balloon catheter in which, after passing through a catheter, a balloon provided at the distal end of the catheter is inflated to expand the stenotic part. I have.

  In this case, when inserting the balloon catheter, first, a relatively thin and flexible guide wire is inserted, the distal end of the guide wire reaches a target position, and then the catheter is inserted along the outer periphery of the guide wire. In this state, after the balloon portion is inflated to expand the stenosis, the guide wire and the balloon catheter are extracted.

  Therefore, the guide wire is required to have so-called push ability, which has a rigidity capable of breaking through the stenosis and firmly holding the balloon catheter. On the other hand, the distal end of the guide wire is required to have flexibility so as not to damage the inner wall of a blood vessel or the like.

  In general, a radiopaque marker is provided at the distal end of the guide wire so that the guide wire can accurately reach the stenosis, so that the exact position of the guide wire can be confirmed. . On the other hand, an X-ray opaque marker is also provided at the distal end of the balloon catheter, so that accurate placement of the balloon portion at the stenosis site can be confirmed.

  As such a conventional guide wire, for example, Japanese Patent No. 3091328 discloses a medical guide having a hand portion and a tip portion, in which all or a part of an elongated flexible shaft is inserted and fixed in a coil. In the wire, the coil has a single-layer winding made of a radio-opaque material disposed on the tip side thereof, and a multi-layer including at least one or more radio-opaque materials and a radiation transmitting material disposed on the other end side thereof. A medical guidewire comprising a combination with a wound is disclosed.

Also, Japanese Patent Application Laid-Open No. 2000-135289 discloses a guide wire composed of a core wire and a metal coil attached to the outer periphery of the distal end portion of the core wire. The first metal coil is preferably made of platinum or stainless steel, the second metal coil 24 is made of an X-ray opaque material such as platinum, and the second metal coil is mounted on the tip side. It is described that flexibility is imparted by increasing a pitch interval between metal coils.
Japanese Patent No. 3091328 JP 2000-135289 A

  However, in the guide wire disclosed in the above-mentioned Japanese Patent No. 3091328, both the single-wound coil and the multi-wound coil include a radiopaque material. For this reason, X-rays cannot distinguish between the two, and the entire coil portion is recognized as an integral X-ray opaque portion.

  For this reason, when inserting the above-mentioned balloon catheter, the radiopaque marker of the balloon catheter overlaps with the coil portion of the guide wire, making it difficult to recognize the balloon catheter by X-rays, and There was a problem that it could not be placed accurately.

  In the guide wire disclosed in Japanese Patent Application Laid-Open No. 2000-135289, since the specific winding method and pitch of the first metal coil and the second metal coil are not limited, the pushability that can break through the constriction and the tip It was difficult to simultaneously satisfy the required performance of flexibility of the part.

  Therefore, an object of the present invention is to provide a sufficient pushability so that the guidewire can be easily inserted, and to be able to prevent the tubular organ from being damaged at the time of insertion and withdrawal while having a flexible tip, and It is an object of the present invention to provide a guide wire that facilitates positioning of a balloon catheter by X-rays.

In order to achieve the above object, a first aspect of the present invention is a guide wire including a core wire having a tip portion having a smaller diameter than a main body portion and a metal coil attached to the outer periphery of the tip portion of the core wire,
The metal coil is disposed on the distal end side of the core wire, is joined to a single-winding first metal coil made of a radiopaque material, and is joined at a proximal end of the first metal coil. The present invention provides a guide wire comprising a multi-winding second metal coil made of a material having a higher X-ray permeability than one metal coil, wherein adjacent wires of the second metal coil are wound in close contact with each other. is there.

  According to the first aspect of the invention, since the second metal coil is formed as a multi-turn wound in close contact, the pushability at the time of insertion into the tubular organ can be maintained, and the selection of the course at the branch portion is easy. It is. In addition, since the first metal coil is formed as a single turn, the flexibility of the distal end portion is increased, and damage to the tubular organ during insertion or withdrawal can be prevented.

  Further, since the second metal coil is made of a material having a higher X-ray permeability than the first metal coil, even if the X-ray opaque marker of the balloon catheter overlaps with the second metal coil of the guide wire, the marker is used. Can be recognized, so that the balloon catheter can be arranged at an accurate position.

  A second aspect of the present invention provides the guide wire according to the first aspect, wherein the adjacent wires of the first metal coil are wound so as to have a space equal to or less than the wire diameter of the first metal coil. Things.

  According to the second aspect of the present invention, by providing an interval equal to or less than the wire diameter between the adjacent wires of the first metal coil at the distal end, the flexibility of the distal end can be further improved.

  A third aspect of the present invention provides the guidewire according to the first or second aspect, wherein the length of the metal coil is 200 to 400 mm.

  According to the third aspect, the pushability when inserting the distal end portion of the guide wire into the tubular organ can be sufficiently maintained.

  A fourth aspect of the present invention provides the guide wire according to any one of the first to third aspects, wherein the length of the first metal coil is 20 to 40 mm.

  According to the fourth aspect, it is possible to sufficiently maintain the pushability at the time of insertion into the tubular organ and sufficiently impart the flexibility of the distal end portion.

  According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the wire constituting the first metal coil includes a superelastic alloy disposed on an outer periphery and an X-ray opaque disposed at a central portion thereof. An object of the present invention is to provide a device for treating a tubular organ, which is composed of a conductive material.

  According to the above invention, the first metal coil is composed of the superelastic alloy disposed on the outer periphery and the X-ray opaque material disposed at the center thereof. As compared with the first metal coil using only the first metal coil, the flexibility and the shape restoring property are high, and furthermore, when it is placed in a tubular organ such as a blood vessel, its position can be visually recognized by an X-ray fluoroscopic camera. In addition, the balloon catheter can be accurately placed at the intended treatment site. In addition, since it can be shaped into a predetermined shape such as a J-shape or an L-shape, for example, it is possible to return to a shape in which a course can be easily selected at a branch portion in the tubular organ.

  ADVANTAGE OF THE INVENTION According to the guide wire of this invention, while a front-end | tip part is flexible and prevents damage to the inner wall of a tubular organ, while having sufficient pushability which is not easily deformed in the middle of insertion of a guide wire, it further has X. The positioning of the balloon catheter by lines is easy. Therefore, this guidewire is suitably used for treatment of a stenosis in a thin and meandering tubular organ with a balloon catheter or the like.

  1 to 5 show one embodiment of a guide wire according to the present invention. FIG. 1 is a side view of the distal end portion of the guide wire, FIG. 2 is a side sectional view of the distal end portion of the guide wire, and FIG. 3 is a diagram showing a use state of the guide wire in a stenotic blood vessel. FIG. 4 is a side sectional view showing a state before the balloon catheter is inflated, and FIG. 4B is a side sectional view showing the state after the balloon catheter and the guide wire are pulled out after use in FIG. FIG. 5 and FIG. 5 are views showing the state of the stenotic part of the blood vessel after the treatment.

  As shown in FIGS. 1 and 2, the guide wire 10 includes a core wire 20, a metal coil 30 mounted on an outer periphery of a distal end portion 22 of the core wire 20, and a hydrophilic coating that covers the distal end portion 22 of the core wire 20 and the metal coil 30. And a conductive resin film 40. The metal coil 30 includes a first metal coil 31 on the distal end side of the core wire 20 and a second metal coil 32 on the base side, and both are joined by a brazing material 52.

  The core wire 20 is reduced in diameter in two stages such that the distal end portion 22 is reduced in diameter in the distal direction from the main body portion 21 and becomes a reduced diameter portion 22b and a most distal end portion 22c via a tapered portion 22a. ing. In the present invention, the distal end portion 22 may have a smaller diameter than the main body portion 21 and may have the above-described stepped shape or may be entirely tapered.

  The material of the core wire 20 is not particularly limited, and an elastic material such as a superelastic material, stainless steel, or a piano wire is preferably used. Examples of the superelastic material include a Ni-Ti alloy, a Cu-Zn-X (X = Al, Fe, etc.) alloy, and a Ni-Ti-X (X = Fe, Cu, V, Co, etc.) alloy.

  Further, as the core wire 20, a wire processed into a wire having a predetermined wire diameter by a known method such as hot forging, hot rolling, or cold working can be used.

  The outer periphery of the main body 21 may be coated with a hydrophobic resin film in order to provide slipperiness and thrombus adhesion prevention. As such a hydrophobic resin film, for example, a silicon resin, a fluorine-based resin or the like is preferably adopted.

  A second metal coil 32 is mounted on the outer periphery of the distal end portion 22 of the core wire 20 near the base, and a first metal coil 31 is mounted on the distal end side. The base end of the second metal coil 32 is fixed to the core wire 20 by a brazing material 51, and the tip end is fixed to the core wire 20 and the first metal coil 31 by a brazing material 52. Further, the first metal coil 31 has its tip end fixed to a round head 53 made of brazing material.

  The first metal coil 31 is a single turn made of a radiopaque material. By forming the single-winding in this way, flexibility can be given to the foremost portion of the guidewire 10. The first metal coil 31 also functions as a radiopaque marker on the guidewire.

  As an X-ray opaque material, a heavy element metal is preferably used. For example, gold, platinum, silver, bismuth, tungsten, or an alloy containing these metals is used.

  The wire diameter of the metal coil 31 is preferably 0.04 to 0.09 mm. The diameter of the entire metal coil 31 is preferably 0.25 to 0.45 mm.

  As shown in FIG. 2, the first metal coil 31 is wound such that adjacent wires have a space 33 which is a space. By thus increasing the interval between the wires, flexibility can be imparted to the forefront portion. Here, it is preferable that the size of the interval 33 be equal to or less than the wire diameter of the wire forming the first metal coil 31. It is not preferable that the winding is a close winding with the interval 33 being zero, since the flexibility of the leading end portion is reduced. Further, if the interval 33 exceeds the wire diameter of the wire, the flexibility of the distal end portion decreases, which is not preferable. Specifically, it is preferable that the interval 33 is 0.01 to 0.07 mm.

  Further, the length of the first metal coil 31 is preferably 20 to 40 mm. If the length is less than 20 mm, the flexibility at the distal end is reduced and becomes insufficient, and if it is more than 40 mm, the overall rigidity is reduced and the operability of the guidewire is reduced.

  Further, the first metal coil 31 may be made of a wire containing an X-ray opaque material in a Co-based alloy or the like, or a wire such as a clad material in which different metals are formed in a multilayer structure. The first metal coil 31 must be manufactured within a range where elastic deformation is possible, and the shape and the like tend to be limited.

  FIG. 9 shows a wire that is particularly preferably used in the present invention, which solves the above-mentioned problems. This wire is composed of a superelastic alloy b disposed on the outer periphery and an X-ray opaque material a disposed at the center thereof. The superelastic alloy b disposed at the outer periphery and the X-ray opaque material a disposed at the center may be integrated or separately movable relative to each other. Since this wire is formed of the X-ray opaque material a disposed at the center and the superelastic alloy b disposed at the outer periphery, it is possible to naturally bend and respond to the bent portion of the tubular organ. It has both flexibility and visibility that allows the position of the first metal coil 31 to be visually recognized by an X-ray fluoroscopic camera, so that the guide wire 10 and the balloon catheter of the present invention can be smoothly placed on a treatment site inside a tubular organ for the purpose. , And can be placed accurately.

  In addition, a metal such as Au, Pt, or Pd is used as the X-ray opaque material a disposed in the center, and a Ni-Ti based shape memory alloy is used as the superelastic alloy b disposed on the outer periphery. And the like are preferably used. Further, the relationship between the diameter X of the X-ray opaque material a disposed at the center and the diameter Y of the wire in FIG. 9 is such that the cross-sectional area of the X-ray opaque material a disposed at the center is the cross-section of the wire. It is preferable to set so as to be in a range of 10 to 40% with respect to the area.

  The second metal coil 32 is made of a material having a higher X-ray permeability than the first metal coil, and two or more wires are closely wound to form a multi-turn.

  As a material of the second metal coil 32, a material having a higher X-ray permeability than the first metal coil 31 is used. Examples of such a material include stainless steel and a Ni-Ti alloy.

  The wire diameter of the metal coil 32 is preferably 0.04 to 0.09 mm. Further, the diameter of the entire metal coil 32 is preferably 0.25 to 0.45 mm.

  As described above, since the second metal coil 32 has a multi-turn structure in which two or more wires are in close contact with each other, the rigidity of the guide wire can be improved. The multi-winding is not particularly limited, but is preferably 2 to 3 windings, and more preferably 2 windings.

  Both ends of the first metal coil 31 and the second metal coil 32 are joined to the core wire 20 by brazing materials 51, 52 and a head 53. As such a joining method, conventionally known soldering or welding can be used, but the present invention is not particularly limited to these joining methods, and the joining may be performed with a resin, an adhesive, or the like.

  In the present invention, the entire length of the metal coil 30 is preferably 200 to 400 mm. If the diameter is less than 200 mm, the clearance between the balloon catheter lumen and the core wire of the guide wire to which the coil is not joined is large in the bent blood vessel, which causes bending in the catheter, and the operability is reduced. Exceeding this is not preferable because sufficient pushability cannot be obtained due to a decrease in the rigidity of the distal end portion.

As shown in FIG. 1, the outer periphery of the metal coil 30 and the distal end portion 22 of the core wire 20 are covered with a hydrophilic resin film 40. As the hydrophilic resin film _{40, -OH, -CONH 2, -COOH} , -NH 2, -COO -, -SO 3 - resin having a hydrophilic group such as is preferred.

  The outer periphery of the distal end portion 22 of the core wire 20 may be covered with the above-mentioned hydrophilic resin film 40 after being covered with a resin layer (not shown) in advance. Examples of such a resin layer include polyurethane, polyether block amide, polyethylene, polyvinyl chloride, polyester, polypropylene, polyamide, polystyrene, fluororesin, and silicone resin.

  In this case, as the hydrophilic resin film 40, one having a functional group capable of binding to the surface of the resin layer is preferably employed. For example, as the resin layer, a resin having an isocyanate group remaining or a resin having a reactivity with an isocyanate group is used.When a resin having a reactivity with an isocyanate group is used, a compound having an isocyanate group is further reacted. After that, polyvinylpyrrolidone, polyethylene glycol, or the like may be bound as the hydrophilic resin film 40 via these isocyanate groups. The method of forming such a hydrophilic resin film is described in detail in, for example, JP-A-5-184666, JP-A-7-80078, and JP-A-7-124263.

  Next, a method of using the above guide wire 10 will be described. FIGS. 3 to 5 show examples in which the guidewire 10 is applied to a method for treating a stenotic portion 65 of a blood vessel 60 which is a tubular organ.

  First, the guide wire 10 is inserted into the blood vessel 60, and the catheter 70 is inserted along the outer periphery of the guide wire 10. For this insertion, the catheter 70 may be inserted after the guide wire 10 is inserted first. When the distal end of the guide wire 10 is slightly advanced while the catheter 70 is arranged around the guide wire 10, the catheter 70 May be repeated by repeating the operation of causing the robot to follow. After the distal end of the guide wire 10 is passed through the stenotic portion 65 in the blood vessel 60 in this way, the balloon portion 71a at the distal end of the catheter 70 is accurately placed on the inner periphery of the stenotic portion 65, as shown in FIG. .

  The catheter 70 has a double structure including a catheter main body 72 into which the guide wire 10 is inserted, and an outer tube 71 provided on the outer periphery of the catheter main body 72 to inject a fluid into the balloon portion 71a. The catheter body 72 and the outer tube 71 are joined to the proximal end of the balloon portion 71a, and a fluid such as air or saline is injected into the balloon portion 71a through a gap between the outer tube 71 and the catheter body 72. It is supposed to be.

  An X-ray opaque marker 73 is provided on the catheter body 72 at a position corresponding to the balloon portion 71a.

  Since the first metal coil 31 of the guide wire 10 is radiopaque, the position of the guide wire 10 in the blood vessel 60 can be visually recognized accurately by X-rays. At the same time, since the second metal coil 32 has high X-ray transparency, even when the position of the second metal coil 32 and the position of the X-ray opaque marker 73 overlap as shown in FIG. The position of the radiopaque marker 73 can be visually recognized accurately by the line. Therefore, the balloon portion 71a can be accurately arranged in the stenosis portion 65 without the radiopaque marker 73 being blocked by the second metal coil 32.

  Next, in this state, as shown by an arrow A in FIG. 3B, a fluid such as air is injected into the space 75 from a gap between the catheter main body 72 and the outer tube 71, and the balloon portion 71a is expanded and expanded. Then, the catheter 70 is moved back and forth as necessary, and a treatment for pushing and expanding the stenosis 65 is performed.

  Thereafter, as shown by an arrow B in FIG. 4, after the fluid is drained to reduce the diameter of the balloon portion 71a to the original state, the guide wire 10 and the catheter 70 are pulled out of the blood vessel 60, and the treatment is completed. As a result, as shown in FIG. 5, the stenotic portion 65 of the blood vessel 60 can be expanded.

  As described above, according to the guide wire 10, the positioning of the balloon catheter by X-rays is easy, and the balloon catheter can be accurately arranged at a target position. Further, the pushability at the time of insertion of the entire distal end portion of the guide wire does not decrease, and the course at the branch portion of the tubular organ can be easily selected. In addition, the increased state-of-the-art flexibility prevents damage to the tubular organ during insertion and withdrawal.

Example 1
A guidewire 10 as shown in FIGS. 1 and 2 was manufactured by the following steps. The core wire 20 was made of stainless steel, and had a body part 21 having a wire diameter of 0.35 mm and an overall length of 1800 mm. From the base side of the core wire 20, the tapered portion 22a has a length of 50 mm, the reduced diameter portion 22b has a length of 300 mm (wire diameter 0.2 mm), and the foremost portion 22c has a length of 20 mm (wire diameter 0.05 mm). The tip 22 was formed. The reduced diameter portion 22b is formed in a tapered shape from the most distal end portion 22c side toward the main body portion 21 for about 120 mm, and then formed to have the same diameter.

  Next, the second metal coil 32 made of stainless steel, having a wire diameter of 0.07 mm, a coil diameter of 0.35 mm, and a length of 300 mm, and wound in a state where two wires are tightly wound with two turns, is reduced in diameter to the reduced diameter portion 22 b of the core wire 20. And the base end of the second metal coil 32 was joined to the tapered portion 22a of the core wire 20 with the brazing material 51.

  Next, a first metal coil 31 made of platinum and wound with a wire diameter of 0.07 mm, a coil diameter of 0.35 mm, a length of 30 mm, and a single-winding so that the distance 33 between the wires is 0.03 mm is used. After the base end of the first metal coil 31 and the front ends of the core wire 20 and the second metal coil 32 are joined with the brazing material 52, the first metal coil The tip of 31 was joined to a round head 53.

  Finally, the surfaces of the first metal coil 31, the second metal coil 32, and the distal end portion 22 of the core wire 20 are subjected to hydrophilic treatment for 300 mm with polyvinylpyrrolidone, and the guide wire of the first embodiment as shown in FIGS. Got.

Example 2
A guide wire of Example 2 was obtained under the same conditions as in Example 1 except that the wire diameter of the first metal coil 32 was changed to 0.05 mm.

Comparative Example 1
In Example 1, a guide wire of Comparative Example 1 was obtained under the same conditions as in Example 1 except that the second metal coil 32 was wound in a single turn.

Comparative Example 2
A guide wire of Comparative Example 2 was obtained under the same conditions as in Example 2 except that the first metal coil 32 was closely wound.

Comparative Example 3
In Example 2, a guide wire of Comparative Example 3 was obtained under the same conditions as Example 2 except that the interval 33 between the wires of the first metal coil 32 was 0.08 mm.

Test example 1
With respect to the guide wires of Example 1 and Comparative Example 1, the load from the bending load tester was measured while changing the distance from the tip of the guide wire, and the tip rigidity was measured.

  In the load measurement using a bending load tester, the distance between the fulcrums was set to 15 mm, and the maximum value of the load when pushing 1 mm at a speed of 10 mm / min was measured. The results are summarized in FIG.

  As shown in FIG. 6, when the distance from the tip, which is the position of the second metal coil 32, is around 30 to 120 mm and 150 mm or more, the rigidity of the first embodiment is higher than that of the comparative example 1 and the second metal coil It can be understood that the rigidity of the guide wire is improved and the pushability can be maintained by forming the double winding 32.

Test example 2
For the guide wires of Example 2 and Comparative Examples 2 and 3, the tip flexibility was measured by the method shown in FIG.

  In other words, the leading end portion 5 mm of the guide wire 10 is pressed against a resin plate 80 having a thickness of 1 mm, and the resistance load when pushing 1 mm at a speed of 10 mm / min along the arrow direction in FIG. The maximum value (the maximum abutting load) was measured. The results are shown in FIG.

  As shown in FIG. 8, in the second embodiment in which the interval 33 between the first metal coils 31 is within a preferable range in the present invention, the maximum contact load is as low as 1.2 g, and the flexibility of the tip is improved. You can see that there is.

  On the other hand, in Comparative Example 2 in which the interval 33 between the first metal coils 31 is zero, that is, in close contact winding, and in Comparative Example 3 in which the interval 33 exceeds the wire diameter of 0.05 mm, the maximum load is smaller than that in Example 2. It is high at 3.2 g and 1.7 g, respectively, and it is understood that the flexibility of the tip portion is inferior to that of Example 2.

  The present invention is used, for example, when inserting a catheter into a tubular organ of the human body such as a blood vessel, ureter, bile duct, organ, etc., is used to guide the tip of the catheter to a target location, and has a sufficient pushability, and It can be suitably used as a guide wire that can be easily positioned in the inside.

FIG. 1 is a side view of a distal end portion of a guidewire, showing one embodiment of a guidewire according to the present invention. FIG. 3 is a side sectional view of the distal end portion of the guide wire. It is a figure which shows the use state of the same guide wire in a stenotic blood vessel, Comprising: (A) The state before inflating a balloon catheter, (B) The side sectional view which shows the state after inflating a balloon catheter. FIG. 4 is a side sectional view showing a state where a balloon catheter and a guide wire have been pulled out after use in FIG. 3. It is a figure which shows the state of the stenosis part of the blood vessel after a treatment. 4 is a table showing measurement results of tip rigidity in an example. It is explanatory drawing which shows the measuring method of the front-end | tip flexibility in an Example. It is a chart showing the measurement result of tip part flexibility in an example. It is explanatory drawing which shows the other example of the wire which comprises the 1st metal coil in this invention.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 10 Guide wire 20 Core wire 21 Main part 22 Tip 22a Taper part 22b Reduced diameter part 22c Foremost part 30 Metal coil 31 First metal coil 32 Second metal coil 33 Interval 40 Hydrophilic resin film 51, 52 Brazing material 53 Head Reference Signs List 60 blood vessel 65 stenosis part 70 catheter 71 outer tube 71a balloon part 72 catheter body 73 X-ray opaque marker 75 space 80 resin plate A, B arrow a X-ray opaque material arranged in the center part b Elastic alloy

Claims (5)

In a guide wire including a core wire having a tip portion having a smaller diameter than the main body portion and a metal coil attached to the outer periphery of the tip portion of the core wire,
The metal coil is disposed on the distal end side of the core wire, is joined to a single-winding first metal coil made of a radiopaque material, and is joined at a proximal end of the first metal coil. A guide wire comprising a multi-strand second metal coil made of a material having a higher X-ray permeability than one metal coil, wherein adjacent wires of the second metal coil are wound in close contact with each other. .   The guide wire according to claim 1, wherein adjacent wires of the first metal coil are wound so as to have a space equal to or less than a wire diameter of the first metal coil.   The guidewire according to claim 1, wherein the length of the metal coil is 200 to 400 mm.   The guidewire according to any one of claims 1 to 3, wherein the length of the first metal coil is 20 to 40 mm. 5. The wire according to claim 1, wherein the wire forming the first metal coil includes a superelastic alloy disposed on an outer periphery and an X-ray opaque material disposed at a center thereof. 6. The described guidewire.