JP2011125556A - Guide wire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a guide wire having a distal end part surely habitually bent in a desired shape, and suppressing the increase of cost, even though the guide wire is formed of a superelastic Ni-Ti alloy. <P>SOLUTION: The guide wire 10 includes a core wire 20 having a distal end part at least made of superelastic Ni-Ti alloy, and a coil 30 made of a Pt (platinum)-based alloy or W (tungsten) arranged on the outer periphery of the distal end part of the core wire 20, the distal end part of the core wire 20 extends in a linear shape in an initial shape and the wire diameter D1 of a part of a predetermined length from the distal end tip thereof is 0.02 to 0.10 mm, a gap C1 of 0.01 to 0.08 mm is formed between the outer periphery of the part of a predetermined length from the distal end tip of the core wire 20 and the inner periphery of the coil, and the gap C2 between the adjacent coil wires 32, 32 of a part arranged on the outer periphery of the part of the predetermined length from the distal end tip of the core wire 20 of the coil 30 is 0.03 to 0.08 mm. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a guide wire used when a tube such as a catheter is inserted into a human tubular organ such as a blood vessel, a ureter, a bile duct, or a trachea.

  Conventionally, in order to inspect and treat human tubular organs such as blood vessels, ureters, bile ducts, and trachea, a tube-like catheter is inserted and a drug such as a contrast medium or an anticancer agent is administered, or tissue is removed by forceps through the catheter. Some of them are collected. When inserting the catheter, a relatively thin and flexible guide wire is inserted into the tubular organ, and the distal end of the guide wire reaches the target location, and then the catheter is inserted along the outer periphery of the guide wire. .

  When the guide wire is inserted into a complicatedly bent tubular organ such as a blood vessel, a superelastic alloy such as a Ni—Ti alloy is preferably used.

  In order to select and insert a desired branch tube at the branch portion of the tubular organ, the distal end portion of the guide wire is bent in advance into a bent shape such as a “J-shape” or “heft-shape”. Shaped ones are in circulation, and doctors select and use guide wires with appropriate bending shapes according to the treatment site and patient.

  However, in the above case, guide wires with various bent shapes must be prepared, which is wasteful, and the shape of the branch portion of the tubular organ varies depending on the treatment site and the patient. This guide wire cannot always be used as it is. For this reason, doctors often use the guide wire by bending the tip of the guide wire into a predetermined shape so that the tip can be easily inserted into the branch pipe in accordance with the treatment site or patient. However, the Ni—Ti-based superelastic alloy has a problem that its tip is difficult to bend.

  In order to bend and bend the tip of a guide wire using a core wire made of a Ni-Ti alloy, the following patent document 1 is made of an alloy having a basic composition of Ni and Ti, and is processed into a linear shape. A medical guide wire having a core wire provided with a part that is easy to be plastically deformed by cold working a part of its entire length after heat treatment is disclosed.

  Patent Document 2 below includes a tip portion and a substrate portion and is made of a Ni-Ti alloy, and the annealing temperature differs between the tip portion and the substrate portion, and the tip portion is subjected to heat treatment at 700 ° C. or higher. A catheter guide wire is disclosed in which a core material having a super elastic characteristic at 37 ° C. and plasticity against shape deformation at 80 ° or less is coated with a synthetic resin.

  On the other hand, in Patent Document 3 below, a superelastic core material including a main body portion, a tip portion having a diameter smaller than that of the main body portion, a transition portion between the main body portion and the tip portion, An X-ray contrast metal coil provided in close contact with the tip, and a synthetic resin coating member that covers at least a part of the contrast metal coil and the core material to form a substantially smooth outer surface; A guide wire comprising a hydrophilic lubricating layer covering at least a part of the synthetic resin covering member is disclosed.

JP 2001-9041 A JP-A-2-289267 JP-A-10-146390

  The medical guide wire disclosed in Patent Document 1 is formed into a transition by performing a cold working on a part of a core wire after being processed into a linear shape and subjected to a heat treatment, thereby enabling a bending bend. However, since it is necessary to perform cold working, the manufacturing cost increases, the toughness becomes poor, and the possibility of cracking and breaking increases.

  Further, the catheter guide wire of Patent Document 2 has a disadvantage in that the manufacturing process is complicated and the cost is increased because different heat treatments are performed on the substrate part and the tip part. Further, since the plastic deformability at the tip is given by heat-treating the tip at a high temperature and lowering the yield point, even if the doctor shapes the tip into an appropriate bent shape, a tube such as a catheter is used. When the guide wire is inserted into the guide wire, there is a demerit that its bent shape is stretched and easily returns to the original shape, and it is difficult to maintain the bent shape of the tip portion.

  Further, in the guide wire of Patent Document 3, since the X-ray contrast-enhanced metal coil is provided in close contact with the distal end portion of the superelastic core material, the distal end portion of the guide wire becomes hard, and the inside of the tubular organ There is a problem in the workability of insertion into

  Therefore, even if the core wire is formed of a Ni-Ti-based superelastic alloy, the object of the present invention is to be able to reliably bend the tip portion into a desired shape, suppress an increase in cost, It is an object to provide a guide wire that is less likely to crack or break, has a flexible tip, and has a high ability to maintain a bent shape.

  In order to achieve the above object, a guide wire according to the present invention includes a core wire having at least a tip portion made of a Ni-Ti superelastic alloy, and a coil made of a Pt alloy or W disposed on the outer periphery of the tip end portion of the core wire. The tip of the core wire extends in a straight line with an initial shape, and the wire diameter D1 of a predetermined length portion from the tip is 0.02 to 0.10 mm. A gap C1 of 0.01 to 0.08 mm is formed between the outer periphery of a portion having a predetermined length from the leading edge of the core wire and the inner periphery of the coil, and the coil has a predetermined length from the leading edge of the core wire. The gap C2 between the coil wire rods adjacent to each other disposed on the outer periphery of the portion is 0.03 to 0.08 mm.

  In the guide wire of the present invention, it is preferable that the coil has a wire diameter D2 of 0.057 to 0.778 mm.

  In the guide wire of the present invention, it is preferable that the outer periphery of the core wire and the coil is coated with a resin layer made of a polyurethane-based synthetic resin having a thickness T of 0.01 to 0.1 mm.

  In the guide wire of the present invention, the coil has a distal end portion fixed to the most distal end portion of the core wire, and a proximal end portion thereof from a portion where the core wire has a wire diameter D1 of 0.02 to 0.10 mm. The axial length of the portion fixed to the thick base side and having the core wire diameter D1 of 0.02 to 0.10 mm is preferably 1 to 30 mm.

  According to the present invention, the wire diameter D1 of a portion having a predetermined length from the forefront of the core wire is 0.02 to 0.10 mm, and 0.01 to the portion between the outer periphery of the core wire and the inner periphery of the coil. A coil having a gap C1 of .about.0.08 mm and a gap C2 between the coil wires of 0.03 to 0.08 mm is arranged. By bending the part, the Pt alloy or W In addition to the deformation of the coil, the core wire is also surely distorted and can be given a bent shape, and the distal end portion of the guide wire can be bent in any shape and direction.

  In this case, if the wire diameter D1 of the portion of the predetermined length from the leading edge of the core wire is less than 0.02 mm, it is difficult to obtain sufficient rigidity as the core wire, and if it exceeds 0.10 mm, the tip portion becomes too hard. End up. Further, if the gap C2 between the coil wires is less than 0.03 mm, adjacent coil wires interfere with each other when they are bent, making it difficult to effectively give a two-dimensional bent shape. If it exceeds, the ratio of the gap between the coil wires is large, and X-rays are easily transmitted, and the visibility under X-ray fluoroscopy is deteriorated.

  And in the guide wire of the present invention, even if it is a guide wire using a core wire made of a Ni-Ti superelastic alloy, without subjecting the tip of the core wire to secondary processing or heat treatment, Since the tip portion can be bent and bent, an easy-to-use guide wire can be provided and the manufacturing cost can be reduced.

1 shows an embodiment of a guide wire according to the present invention, where (a) is an explanatory view showing the whole in cross section, and (b) is an explanatory view showing a resin layer in cross section. It is explanatory drawing which shows the state which bent and bent the front-end | tip part of the guide wire. It is explanatory drawing which shows the test method of the bending bending performance of the guide wire of various dimensions. In the same bending performance test, it is explanatory drawing which shows a state in case the clearance gap between coil wire materials is smaller than predetermined value.

  Hereinafter, an embodiment of a guide wire of the present invention will be described with reference to the drawings.

  As shown in FIGS. 1A and 1B, the guide wire 10 in this embodiment includes a core wire 20, a coil 30 disposed on the outer periphery of the distal end portion of the core wire 20, and outer periphery of the core wire 20 and the coil 30. And a coated resin layer 40.

  The core wire 20 includes a base portion 21 having a constant diameter and a predetermined length, a taper portion 23 gradually reduced in diameter from the base portion 21 toward the tip, and a reduced diameter portion extending from the tip of the taper portion 23 in a predetermined length. 25.

  The core wire 20 is made of Ni—Ti, such as Ni—Ti, Ni—Ti—X (X = Fe, Cu, V, Co, Cr, Mn, Nb, etc.), which has high biocompatibility and super elasticity. It is formed from a superelastic alloy.

  The core wire 20 in this embodiment is integrally formed continuously from the proximal end to the distal end by drawing or extruding from a die hole (the tapered portion 23 and the reduced diameter portion 25 are formed by subsequent machining or etching). Each part is made of the same material, but at least the tip is sufficient if it is the Ni-Ti superelastic alloy, and the other parts are made of stainless steel, Ni, W or the like. Also good.

  As shown in FIG. 1, in this embodiment, a coil 30 is disposed on the outer periphery of the reduced diameter portion 25 and the outer periphery of the tapered portion 23 extending from the proximal end of the reduced diameter portion 25, and this portion is the core wire 20. The tip part a is formed.

  And the front-end | tip part a of this core wire 20 is linearly extended by the initial shape, and the wire diameter D1 of the part b of predetermined length from the most front is 0.02-0.10 mm. In this embodiment, the reduced diameter portion 25 extends in a straight line parallel to the guide wire axis at a constant diameter and the wire diameter D1 from the foremost end to the proximal end of the reduced diameter portion 25. The diameter-reduced portion 25 forms the “part of a predetermined length from the most advanced” of the present invention.

  The portion b having a predetermined length from the forefront of the core wire 20 only needs to have a wire diameter D1 of 0.02 to 0.10 mm, and the portion b is reduced in a tapered shape within the range of the wire diameter D1. Alternatively, the diameter may be reduced to a stepped shape.

  When the wire diameter D1 of the tip b of the tip portion a having a predetermined length from the front end is less than 0.02 mm, it is difficult to obtain sufficient rigidity of the core wire 20, and when it exceeds 0.10 mm, the tip portion becomes hard. Pass.

  Further, the axial length L of the portion of the tip end a where the wire diameter D1 is 0.02 to 0.10 mm, that is, the axial length L (the reduced diameter portion) of the portion b having a predetermined length from the forefront. The axial length L) from the forefront to the base end of 25 is 1 to 30 mm, and more preferably 5 to 20 mm.

  If the length L in the axial direction of the portion is less than 1 mm, the range in which the tip end portion a can be bent decreases, and if it exceeds 30 mm, the portion with a small wire diameter becomes long and the rigidity of the core wire 20 decreases.

  The coil 30 disposed on the outer periphery of the distal end portion a of the core wire 20 is made of a Pt alloy or W, and is formed by winding a coil wire 32 having a wire diameter D2. The wire diameter D2 of the coil wire 32 is more preferably 0.057 to 0.0778 mm.

  If the wire diameter D2 of the coil wire 32 is less than 0.057 mm, the coil wire diameter D2 is thin, so that it is difficult to resist the superelasticity of the distal end portion a of the core wire 20, and the distal end portion a is difficult to bend and bend. If it exceeds 0.0778 mm, the coil wire diameter D2 is large, so the entire coil 30 is hardened and the flexibility of the tip end portion a of the core wire 20 is reduced.

  Although the said coil 30 is arrange | positioned at the outer periphery of the front-end | tip part a of the core wire 20, the adjacent coil wire material in the part b (reduced diameter part 25) of the predetermined length from the forefront of the core wire 20 of the coil 30 at this time. The coil 30 is formed so that the gap C2 between the 32 and 32 is 0.03 to 0.08 mm. The coil 30 of this embodiment is formed by winding a coil wire 32 with the same gap C2 from the distal end portion to the proximal end portion.

  If the gap C2 between the adjacent coil wires 32 and 32 is less than 0.03 mm, the adjacent coil wire materials 32 and 32 interfere with each other when the tip end a of the core wire 20 is bent and bent, so that the two-dimensional bending is performed. When it becomes difficult to effectively give the shape and exceeds 0.08 mm, the ratio of the gaps between the coil wires is large, the X-rays are easily transmitted, and the visibility under X-ray fluoroscopy is deteriorated.

  As shown in FIG. 2, the two-dimensional bending shape means that the distal end portion of the guide wire 10 is planarly bent with respect to a portion other than the distal end portion, and does not bend on the front side or the back side of the paper. This means that the axial center of the tip portion bends on the same plane with respect to the axial center of the portion other than the tip portion.

  The guide wire 10 has a wire diameter D1 of 0.02 to 0.10 mm in a portion b (reduced diameter portion 25) having a predetermined length from the foremost end of the core wire 20, and includes an outer periphery of the core wire 20 and a coil in the portion. 30 is provided with a clearance C1 of 0.01 to 0.08 mm between the inner periphery of the coil 30 and the coil 30 having a clearance C2 between the coil wires 32 and 32 of 0.03 to 0.08 mm. The coil 30 made of Pt alloy or W is deformed by applying an appropriate force to the portion b of a predetermined length from the most leading edge of the core wire 20 and bending it, and the core wire 20 is also reliably distorted. In addition, a bent shape can be imparted, and the tip of the guide wire 10 can be bent in an arbitrary shape and direction as shown in FIG.

  The coil 30 of this embodiment is wound with the same gap C2 from the distal end to the proximal end. However, as described above, the gap C2 is provided in the portion b having a predetermined length from the most distal end of the core wire 20. The other portions may be wound in close contact with each other, or may be wound in a gap outside the range of the gap C2.

  The coil 30 has a distal end portion a of the core wire 20 inserted through the inner periphery thereof, the distal end portion disposed on the outermost periphery of the core wire 20, and the proximal end portion disposed on the outer periphery of the tapered portion 23 of the core wire 20. . And the front-end | tip part of the coil 30 is fixed to the most advanced part of the core wire 20 via the round head 34 which consists of brazing materials etc., and a base end part is a taper part via the junction part 36 which consists of brazing materials etc. 23 is fixed. Thus, in this embodiment, the proximal end portion of the coil 30 is thicker than the portion of the core wire 20 in which the wire diameter D1 is 0.02 to 0.10 mm (the portion b having a predetermined length from the forefront). It is fixed to the base side.

  In addition, as shown in the partial enlarged view of FIG. 1A, the coil 30 is between its inner periphery and the outer periphery of the portion b (reduced diameter portion 25) having a predetermined length from the most distal end of the core wire 20. It arrange | positions so that the clearance gap C1 of 0.01-0.08 mm may be formed.

  If the gap C1 is less than 0.01, the coil 30 is likely to adhere to the outer periphery of the tip end a of the core wire 20, and the coil 30 and the core wire 20 interfere with each other when bending and are difficult to bend. If it exceeds the upper limit, the coil 30 is too far from the outer periphery of the tip end portion a, and it becomes difficult to impart distortion to the core wire 20.

  A resin layer 40 made of a polyurethane-based synthetic resin having a thickness T of 0.01 to 0.1 mm is coated on the outer periphery of the core wire 20 and the outer periphery of the coil 30 attached to the outer periphery of the distal end portion a of the core wire 20. Yes. In this embodiment, the resin layer 40 is covered so as to cover the entire core wire 20 and the thickness thereof is substantially constant. However, the thickness T of the resin layer 40 in the present invention is the most advanced of the core wire 20. Means a thickness at a position corresponding to a portion b having a predetermined length (see a partial enlarged view of FIG. 1A). The resin layer 40 is coated on the outer periphery of the coil 30, but does not enter the inner periphery of the coil 30, and a gap is formed in the coil 30, and the gap C1 between the inner periphery of the coil and the outer periphery of the core wire is maintained. It has come to be.

  As described above, the outer periphery of the core wire 20 and the coil 30 is covered with the resin layer 40 made of a relatively hard polyurethane-based synthetic resin having a thickness T of 0.01 to 0.1 mm. The shape can be easily retained, and the superelasticity of the core wire 20 can be overcome, so that the distal end portion of the guide wire 10 can be easily bent and bent.

  If the thickness T of the resin layer 40 exceeds 0.1 mm, the resin layer 40 becomes too thick and the flexibility of the distal end portion of the guide wire 10 is impaired. Even when the resin layer 40 is not coated on the outer periphery of the core wire 20 and the coil 30, the tip end a can be held in a predetermined bent shape.

  The outer periphery of the resin layer 40 is preferably coated with a hydrophilic resin such as polyvinyl pyrrolidone, polyethylene glycol, or methyl vinyl ether maleic anhydride copolymer in order to impart slipping property and thrombus adhesion preventing property.

  The guide wire 10 having the above structure is manufactured as follows, for example. First, a Ni—Ti-based alloy material is melted and pulled out from a die having a predetermined diameter or extruded to form a wire having a predetermined wire diameter. In a state where the wire is stretched linearly, heat treatment is performed under a predetermined condition, and shape memory processing is performed so that the wire becomes linear. Thereafter, machining or etching is appropriately performed to form the core wire 20 including the base portion 21, the tapered portion 23, and the reduced diameter portion 25. Next, after the coil 30 is mounted on the outer periphery of the distal end portion a of the core wire 20 as described above, the guide wire 10 is manufactured by covering the outer periphery of the core wire 20 and the coil 30 with the resin layer 40.

  The guide wire 10 has a wire diameter D1 of 0.02 to 0.10 mm in a portion b (reduced diameter portion 25) having a predetermined length from the foremost end of the core wire 20, and includes an outer periphery of the core wire 20 and a coil in the portion. 30 is provided with a clearance C1 of 0.01 to 0.08 mm between the inner periphery of the coil 30 and the coil 30 having a clearance C2 between the coil wires 32 and 32 of 0.03 to 0.08 mm. The coil 30 made of Pt alloy or W is deformed by applying an appropriate force to the portion b of a predetermined length from the most leading edge of the core wire 20 and bending it, and the core wire 20 is also reliably distorted. In addition, a bent shape can be imparted, and the tip of the guide wire 10 can be bent in an arbitrary shape and direction as shown in FIG.

  In the case of bending bending, a jig made of a columnar rod, a cylindrical pipe, or the like is pressed against the distal end portion of the guide wire 10, and the jig is reciprocated like a squeezing to guide the guide wire 10. The tip portion of the wire 10 can be efficiently bent and bent.

  As described above, according to the guide wire 10, even when the core wire 20 made of a Ni-Ti superelastic alloy is used, the distal end portion thereof can be reliably bent and bent. The shape of the tip can be changed as appropriate according to the treatment site and patient, and the convenience can be improved.

  Further, since the coil 30 is arranged at the tip end a of the core wire 20 with a predetermined gap C1, the guide wire tip end portion is compared with the case where the coil is tightly wound around the outer periphery of the core wire as in Patent Document 3. It is possible to suppress the hardening as much as possible, and to maintain the shape maintaining property while maintaining a certain degree of flexibility, and it is possible to prevent the guide wire 10 from being lowered in workability.

  Further, there is no need to perform secondary processing such as cold processing on the tip end a of the core wire 20 (Patent Document 1), or to perform a heat treatment different from the shape memory processing (Patent Document 2), Since the tip portion can be bent and bent, the manufacturing cost of the guide wire 10 can be reduced.

  In this embodiment, since the coil wire diameter D2 is 0.057 to 0.778 mm, the coil wire diameter D2 can be maintained at an appropriate thickness without being too thin and not too thick. The tip portion of the guide wire 10 can be easily bent and bent, and the flexibility of the tip portion of the guide wire 10 can be ensured.

  Furthermore, in this embodiment, the coil 30 has its distal end fixed to the most distal end portion of the core wire 20 and its proximal end portion from the portion where the wire diameter D1 of the core wire 20 is 0.02 to 0.10 mm. The axial length L of the portion fixed to the thick base side and having the wire diameter D1 of the core wire 20 of 0.02 to 0.10 mm is 1 to 30 mm. The length that can be bent and bent can be secured appropriately, and the distal end portion of the guide wire 10 can be easily bent and bent in a desired direction and shape.

(Sample preparation)
A wire rod having a predetermined diameter is prepared using a Ni-Ti alloy, stretched linearly, and held at 510 ° C. for 60 seconds to perform shape memory processing so as to be linear, and then shrink. Twenty-three samples were prepared by cutting so that the wire diameter D1 of the diameter portion 25 would be the numerical values shown in Table 1 below.

  Moreover, the coil wire 32 of the coil wire diameter D2 shown in following Table 1 was wound so that adjacent things might become the clearance gap C2 of following Table 1, and 23 coils 30 were produced.

  These coils 30 were attached to the outer periphery of the tip end portion a of the core wire 20, and both end portions thereof were fixed to the core wire 20 via the head portion 34 and the joint portion 36, and then covered with polyurethane. As a result, various dimensions shown in Table 1 below, that is, D1 (wire diameter of the reduced diameter portion 25), D2 (wire diameter of the coil 30), C2 (gap between the coil wires 32 and 32), C1 (reduced diameter portion). Samples 1 to 23 having a clearance between the outer periphery of 25 and the inner periphery of the coil 30) and T (thickness in the reduced diameter portion 25 of the resin layer 40) were produced.

(Test method)
About each said samples 1-23, the amount of permanent deformation was measured by the method shown in FIG. That is, as shown to Fig.3 (a), after winding the front-end | tip part of each samples 1-23 to the cylinder of diameter 1.2mm, it was made to slide about 5 mm.

  Then, as shown in FIG. 3B, the deformation angle of the tip portion with respect to the portion other than the tip portion is 70 ° or more, and the one having the deformation angle maintained is evaluated as being capable of bending bending. (Shown as “◯” in Table 1), deformation angle is less than 70 °, breaks during winding, or the bent shape cannot be maintained and returned to its original shape, and cannot be bent (Indicated as “x” in Table 1). The results are summarized in Table 1 above.

(Test results)
As shown in Table 1 above, Samples 2 and 3 were both too thin with a wire diameter D2 of the coil 30 of 0.050 mm and could not be bent sufficiently. Sample 7 was a wire of the reduced diameter portion 25. The diameter D1 was too thick at 0.110 mm, and it broke during bending.

  In Samples 8 and 9, the gap C2 between the coil wires 32 and 32 is too narrow, resulting in a three-dimensional shape and not a desired bent shape. In Sample 13, the gap C is too wide and the X-ray The visibility under fluoroscopy was poor.

  As shown in FIG. 4, when the coil 30 is bent, the coil wire rods 32 located on the inner side collide with each other and lose their place, as shown in FIG. Since it is displaced with respect to the axial center, it is considered that it is bent into a three-dimensional shape.

  Sample 14 does not have a gap C1 between the outer periphery of the reduced diameter portion 25 and the inner periphery of the coil 30 (0.00 mm), and cannot retain its shape after bending, and Sample 18 has a gap C1 of 0.10 mm that is too wide. It could not be bent sufficiently.

  In sample 23, the thickness T of the resin layer 40 was too thick, ie, 0.15 mm, and could not be bent sufficiently.

  Samples other than the above samples (3 to 6, 10 to 12, 15 to 17, 19 to 22) all have a wire diameter D1 of the reduced diameter portion 25 of 0.02 to 0.10 mm and a wire diameter D2 of the coil 30. 0.057 to 0.778 mm, the gap C2 between the coil wires 32 and 32 is 0.03 to 0.08 mm, the gap C1 between the outer periphery of the reduced diameter portion 25 and the inner periphery of the coil 30 is 0.01 to 0.08 mm, The thickness T of the resin layer 40 satisfied the range of 0.01 to 0.1 mm, and it was confirmed that the resin layer 40 could be reliably bent and bent.

10 Guide wire 20 Core wire 30 Coil 32 Coil wire 40 Resin layer

Claims (4)

A guide wire comprising at least a core wire made of a Ni-Ti-based superelastic alloy and a coil made of a Pt-based alloy or W arranged on the outer periphery of the tip end of the core wire,
The leading end of the core wire extends linearly with an initial shape, and the wire diameter D1 of a portion of a predetermined length from the leading edge is 0.02 to 0.10 mm,
A gap C1 of 0.01 to 0.08 mm is formed between the outer periphery of the portion having a predetermined length from the forefront of the core wire and the inner periphery of the coil.
The guide is characterized in that a gap C2 between adjacent coil wires of a portion of the coil disposed on the outer periphery of a portion having a predetermined length from the forefront of the core wire is 0.03 to 0.08 mm. Wire.   The guide wire according to claim 1, wherein a wire diameter D2 of the coil is 0.057 to 0.778 mm.   The guide wire according to claim 1 or 2, wherein a resin layer made of a polyurethane-based synthetic resin having a thickness T of 0.01 to 0.1 mm is coated on the outer periphery of the core wire and the coil.   The coil has its distal end fixed to the most distal end of the core wire, and its base end fixed to the base side thicker than the portion where the wire diameter D1 of the core wire is 0.02 to 0.10 mm. The guide wire according to any one of claims 1 to 3, wherein an axial length of a portion in which the wire diameter D1 of the core wire is 0.02 to 0.10 mm is 1 to 30 mm.