JP2005211524A - Guide wire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a guide wire with which a follow-up property of a catheter to the guide wire can be surely improved and operability of the guide wire and the catheter can be improved. <P>SOLUTION: A guide wire 10 includes a core wire 20 of which the diameter of a distal end portion 22 is reduced, and a resin layer 40 covering the core wire 20, and a expanded-diameter portion 41 of which the diameter is partially expanded, is provided in the distal end portion of the resin layer 40 where the diameter-reduced distal end portion 22 of the core wire 20 is disposed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a medical guide wire used to guide the distal end of a catheter to a target location when the catheter is inserted into a human tubular organ such as a blood vessel, a ureter, a bile duct, or a trachea.

  In recent years, for inspection and treatment of human tubular organs such as blood vessels, ureters, bile ducts, trachea, etc., a catheter is inserted to administer contrast agents, etc., or a portion of tissue is collected with forceps through the catheter. Has been done. When inserting a catheter, a relatively thin and flexible guide wire is first inserted into the tubular organ, and after the distal end of the guide wire reaches the target location, the catheter is inserted along the outer periphery of the guide wire. The guide wire is pulled out.

  FIG. 9 shows the insertion state of the catheter at the branch of the blood vessel. That is, at the branch portion of the blood vessel, first, the distal end portion of the guide wire 1 is inserted along the target branch tube 3, and then the catheter 2 is advanced along the outer periphery of the guide wire 1.

  However, if the clearance between the catheter 2 and the guide wire 1 is large, as shown in FIG. 9A, the guide wire 1 tends to be eccentric within the catheter 2, and the distal end of the catheter 2 is connected to the branch tube 3. It will be in the state caught on the base end part of. In this state, even if the catheter 2 is further pushed in and advanced, the catheter may advance to a different branch pipe from the target branch pipe 3 as shown in FIG. 9B. is there.

  Thus, when the clearance between the inner diameter of the catheter 2 and the outer diameter of the guide wire 1 is large, the followability when the catheter 2 is advanced along the guide wire 1 is deteriorated, and the catheter 2 cannot be inserted smoothly. was there.

  On the other hand, in Patent Document 1 below, in a catheter guide wire having a flexible distal end portion and a main body portion, the distal end portion is provided on the distal end side of the guide wire, and the martensite reverse transformation disclosure temperature is 0 ° C. to A shape memory portion made of a shape memory alloy at 40 ° C. and formed to be transformed into a curved shape at a temperature higher than the temperature; and a super elastic portion formed of a super elastic metal following the shape memory portion; A guide wire for a catheter is disclosed. In the embodiment, the tip is formed thicker than the main body by the amount of the coil mounted on the outer periphery thereof.

Patent Document 2 discloses a metal core having a distal end, and a point extending from the proximal direction of the distal end of the metal core and extending to a point in the distal direction of the distal end of the metal core. Distal guidewire sections are disclosed comprising a plurality of polymer fibers extending distally, the fibers being fixedly attached to the metal core at at least one point. It is described that it can be molded into a wide variety of complex and predictable shapes that are not obstructive to the patient and very easily.
Japanese Patent Publication No. 3-44540 JP-A-10-66728

  However, although the above Patent Document 1 shows a coil that is formed thicker than the main body by the amount of the coil mounted on the outer periphery thereof, there is no point about the relationship between the outer diameter of the guide wire and the inner diameter of the catheter. It is not made, and only the portion of the coil attached to the outer periphery of the distal end of the guide wire is thickened on the drawing. Moreover, the thick portion extends over the entire tip of the guide wire. For this reason, even if the gap between the inner diameter of the catheter and the inner diameter of the catheter is reduced by the thicker portion, there is a problem that the inner periphery of the catheter and the distal end portion are large and the friction resistance of the catheter against the guide wire increases. .

  Further, in Patent Document 2 described above, a fiber can be included in the distal end portion of the guide wire so that a doctor can freely shape at the surgical site. In this document, the outer diameter of the guide wire and the inner diameter of the catheter are also provided. No attention has been paid to the relationship with the above, and the amount of fiber contained is only thickened by chance in the drawing. The thick portion is tapered, but in the tapered shape, the raised thick portion is extremely short, so it is considered that the effect of improving the guide property of the catheter is poor.

  Accordingly, an object of the present invention is to provide a guide wire that can reliably improve the followability of the catheter to the guide wire and can improve the operability of the guide wire and the catheter.

  In order to achieve the above object, according to a first aspect of the present invention, the resin includes a core wire having a reduced diameter at a tip end portion and a resin layer that covers the core wire, and the tip end portion at which the core wire has a reduced diameter is disposed. The guide wire is characterized in that a diameter-expanded portion that is partially enlarged is provided at the tip of the layer.

  According to the first aspect of the present invention, the clearance of the enlarged portion of the guide wire with respect to the inner diameter of the catheter to be applied can be reduced, so that the guide wire can be prevented from rattling in the catheter. Further, since the guide wire is not in an eccentric state in the catheter, when inserting the catheter along the outer periphery of the guide wire, the catheter can be smoothly advanced along the path of the guide wire. The followability of the catheter with respect to can be improved.

  Further, since the enlarged diameter portion is partially provided at the distal end portion of the resin layer, the portion that slides between the outer periphery of the guide wire and the inner periphery of the catheter is reduced during insertion of the catheter, and the guide The frictional resistance of the catheter against the wire can be reduced. In addition, since the portion where the enlarged diameter portion is not provided is flexible, the flexibility of the distal end portion of the guide wire is not impaired. Therefore, the operability of the guide wire and the catheter when inserting the catheter can be improved.

  Furthermore, since the clearance of the enlarged portion of the guide wire with respect to the inner diameter of the catheter is small, it is possible to prevent blood or the like in the blood vessel from flowing back beyond the enlarged portion when the guide wire is used.

  According to a second aspect of the present invention, there is provided the guide wire according to the first aspect, wherein the length of the enlarged diameter portion in the axial direction of the guide wire is 10 to 100 mm.

  According to the second aspect of the invention, since the diameter-enlarged portion having an appropriate length can be obtained, the flexibility of the guide wire can be maintained and the followability of the catheter to the guide wire can be sufficiently ensured.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the resin layer has a distal end portion having a smaller diameter than the enlarged diameter portion on the distal end side with respect to the enlarged diameter portion of the resin layer. A guide wire having a length of 5 to 30 mm is provided.

  According to the third aspect of the invention, the distal end portion of the guide wire has a small diameter at the most distal portion of the guide wire, and the small diameter portion can be used to select and advance a path in a branching portion such as a blood vessel. Compared to the case where the entire diameter is expanded, the insertion workability is improved.

  According to a fourth aspect of the present invention, in any one of the first to third aspects of the present invention, a metal coil is mounted on the outer periphery of the reduced diameter end portion of the core wire, and the wire material forming the metal coil is Provided is a guide wire as described above, which is composed of a superelastic alloy disposed on the outer periphery and a radiopaque material disposed in the center thereof.

  According to the fourth aspect of the invention, the wire forming the metal coil is composed of the superelastic alloy disposed on the outer periphery and the radiopaque material disposed in the center thereof. Compared to a metal coil using only a radiopaque material, it has high flexibility and shape restoration, and when placed in a tubular organ such as a blood vessel, its position can be visually recognized by a fluoroscopic camera. The guide wire and the 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.

  According to the guide wire of the present invention, by providing a diameter-enlarged portion that is partially enlarged at the distal end portion of the resin layer in which the reduced-diameter distal end portion of the core wire is disposed, The clearance of the enlarged portion of the guide wire with respect to the inner diameter can be reduced to prevent the guide wire from rattling in the catheter. Further, since the guide wire is not in an eccentric state in the catheter, the followability of the catheter to the guide wire can be improved, for example, at a branching portion such as a blood vessel. Furthermore, since the enlarged diameter part is partially formed at the distal end of the guide wire, the sliding area where the enlarged diameter part contacts the inner wall of the catheter is made as small as possible to reduce the frictional resistance of the catheter against the guide wire. Can do. Furthermore, since the diameter-expanded portion is partially provided, the flexibility of the distal end portion of the guide wire is not impaired, so that the operability of the guide wire and the catheter can be improved.

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

  1 to 5 show an embodiment of a guide wire according to the present invention. The guide wire 10 is mainly composed of a core wire 20, a metal coil 30 attached to the outer periphery of the distal end portion 22 of the core wire 20, and a resin layer 40 that covers the core wire 20 and the metal coil 30. Moreover, the diameter-expanded part 41 expanded partially is provided in the front-end | tip part of the resin layer 40 in which the diameter-reduced front-end | tip part 22 of the core wire 20 is arrange | positioned.

  However, the guide wire of the present invention is not only a guide wire in the above-described manner, but also a guide wire in which the core wire is simply coated with a resin layer, or a metal coil is attached to the entire core wire, and the outer periphery thereof is resin. It can also be applied to a guidewire coated with a layer.

  The core wire 20 includes a base portion 21 and a distal end portion 22 that is reduced in diameter from the base portion 21, and the distal end portion 22 is a tapered portion 22 a that is reduced in diameter from the base portion 21, and is further advanced from the tapered portion. 22b (see FIG. 2).

  The distal end portion 22 only needs to have a shape that gradually decreases in diameter toward the forefront of the core wire 20 and has a reduced diameter. For example, the tip portion 22 may have a tapered shape, a stepped shape, or the like. Such a shape can be formed by means such as machining or etching.

  The length of the diameter-reduced tip 22 is preferably about 30 to 500 mm, and the entire length of the core wire 20 is preferably about 300 to 5000 mm. Moreover, the diameter of the base 21 of the core wire 20 is suitably set according to the objective in the range of about 0.2-3 mm.

  As the material of the core wire 20, an elastic material such as a super elastic material, stainless steel, and piano wire is preferably used. Examples of superelastic materials include Ni—Ti alloys, Cu—Zn—X (X = Al, Fe, etc.) alloys, Ni—Ti—X (X = Fe, Cu, V, Co, etc.) alloys, and the like.

  The Ni-Ti alloys and the like are widely known as shape memory alloys having a shape memory effect and a superelastic (pseudoelastic) effect. Unlike ordinary metal materials that are permanently deformed due to deformation strain exceeding the point, even if deformation strain exceeding the yield point is applied, when the material is unloaded, it returns to its original shape without permanent deformation. Since the return characteristic is also large, it is suitable as the core wire of the guide wire, and the temperature condition for exhibiting the superelasticity (pseudoelasticity) effect is set to the body temperature of humans or animals or lower. For superelasticity (pseudoelasticity), JIS H 7001 issued by the Japanese Standards Association can be referred to.

  A metal coil 30 is disposed on the outer periphery of the distal end portion of the core wire 20 described above, and a base end of the metal coil 30 is fixed to a taper portion 22 a of the core wire 20 with a brazing material 51. Further, the most distal end portion 22b of the core wire 20 and the tips of the metal coils 30 are fixed to a head 52 that is formed of a brazing material and has a round tip. The head 52 can also be formed, for example, by melting the ends of the core wire 20 and the metal coil 30.

  The metal coil 30 is made of a metal wire. This wire is preferably a radiopaque material in that it also acts as a marker during X-ray imaging. As such a radiopaque material, for example, gold, platinum, silver, bismuth, tungsten, or an alloy containing these metals is preferably used.

  The length of the metal coil 30 is preferably 10 to 300 mm. If it is less than 10 mm, the rigidity of the tip is lowered, and the marker action at the time of X-ray contrast is weakened. Moreover, if it exceeds 300 mm, the X-ray marker attached to a device such as a catheter used together with the metal coil overlaps, which makes it difficult to confirm the position.

  Further, the metal coil 30 may be made of a wire material containing a radiopaque material in a Co-based alloy or the like, or a wire material such as a clad material in which different metals are formed in a multilayer structure, but these wires have low elasticity. When large deformation is applied, plastic deformation occurs, so that the metal coil 30 needs to be manufactured within a range where elastic deformation is possible, and the shape and the like tend to be limited.

  FIG. 6 shows a wire rod particularly preferably used in the present invention, which has solved the above-described problems. This wire is composed of a superelastic alloy b disposed on the outer periphery and a radiopaque material a disposed on the center thereof. The superelastic alloy b disposed on the outer periphery and the radiopaque material a disposed on the center may be integrated or may be moved separately. Since this wire is formed of the radiopaque material a disposed at the center and the superelastic alloy b disposed at the outer periphery, the wire can naturally bend and correspond to the bent portion of the tubular organ. It has both flexibility and visibility that allows the position of the metal coil 30 to be visually recognized by an X-ray fluoroscopic camera. The guide wire and catheter of the present invention can be smoothly and accurately applied to a treatment site inside a tubular organ. Can be detained.

  As the X-ray opaque material a disposed in the central portion, a metal such as Au, Pt, or Pd is used. As the superelastic alloy b disposed on the outer periphery, a Ni—Ti-based shape memory alloy or the like is used. Preferably used. In addition, the relationship between the diameter X of the X-ray opaque material a disposed at the center in FIG. 6 and the diameter Y of the wire is such that the cross-sectional area of the X-ray opaque material a disposed at the center is the crossing of the wire. It is preferable to set it in a range of 10 to 40% with respect to the area.

  In addition, the wire comprised by the above-mentioned superelastic alloy b arrange | positioned at the outer periphery and the radiopaque material a arrange | positioned in the center part can also be utilized as a material of the said core wire 20. FIG.

  The core wire 20 and the metal coil 30 described above are entirely covered with a resin layer 40. The resin layer 40 is preferably one that can be subsequently coated with a hydrophilic resin film, such as polyurethane, polyether block amide, polyethylene, polyvinyl chloride, polyester, polypropylene, polyamide, polystyrene, fluorine resin, silicon resin, and the like. Adopted. Moreover, the resin layer 40 may contain a radiopaque material. As the radiopaque material, powders such as bismuth, barium sulfate, and tungsten are preferably used.

  The resin layer 40 has a length that covers the entire core wire 20 and the metal coil 30. Moreover, the thickness of the resin layer 40 is not particularly limited, but is preferably 30 to 100 μm.

  Such a resin layer 40 is coated on the core wire 20 and the metal coil 30 by, for example, extrusion molding using the resin as described above after the metal coil is fixed to the core wire 20.

  And in this invention, the diameter-expanded part 41 expanded partially is provided in the part which coat | covers the front-end | tip part 22 of the core wire 20 of the resin layer 40. As shown in FIG. The diameter-expanded portion 41 includes a covered tube 41a mounted along the axial direction of the guide wire 10 and tapered portions 41b provided at both ends of the covered tube 41a. The tapered portion 41b is provided to prevent the inner wall of the tubular organ from being damaged when the guide wire 10 is inserted into the tubular organ.

  In FIG. 1 (B) and FIG. 4, the length B of the said enlarged diameter part 41 along the axial direction of the guide wire 10 is preferably 10-100 mm, and more preferably 20-50 mm.

  If the length B of the enlarged diameter portion 41 is less than 10 mm, the proximal side of the enlarged diameter portion 41 of the guide wire 10 is left in the catheter at the branching portion of the tubular organ, and the distal end side of the enlarged diameter portion 41 is connected to the branch tube. It becomes difficult to insert into. On the other hand, when the length B of the enlarged diameter portion 41 exceeds 100 mm, the sliding portion between the inner periphery of the catheter and the guide wire increases, and the frictional resistance of the catheter against the guide wire increases. Therefore, it is difficult to insert the catheter, and the operability of the guide wire and the catheter is deteriorated.

  Furthermore, the outer diameter D of the enlarged diameter portion 41 is greater than 1.1 times and less than 1.3 times the outer diameter C of the portion of the guide wire 10 where the diameter is not enlarged. preferable.

  When the size of the outer diameter D with respect to the outer diameter C is less than 1.1 times, the effect of partially reducing the clearance between the catheter inner diameter and the guide wire becomes poor. When the clearance is reduced, the frictional resistance against the catheter increases. However, when the clearance is increased, the guideability of the catheter is degraded.

  Further, when the size of the outer diameter D with respect to the outer diameter C exceeds 1.3 times, the outer diameter C in the portion where the guide wire 10 is not expanded is thinner than the outer diameter D of the expanded portion 41. Therefore, the rigidity of the guide wire 10 is reduced, the pushability of the guide wire 10 is lowered, and the operability is deteriorated. Moreover, since the inclination angle of the taper part 41b provided in the diameter-expanded part 41 becomes large, when inserting the catheter following the catheter, the inner periphery of the catheter is caught on the taper part 41b, which is not preferable.

  Furthermore, in the guide wire 10 of the present invention, as shown in FIG. 4, the outer diameter D of the enlarged diameter portion 41 is 0.01 to 0.1 mm smaller than the inner diameter of the catheter 50 to which the guide wire 10 should be applied. It is preferable to be formed.

  According to this, since the clearance E can be set appropriately, rattling is effectively prevented without greatly increasing the frictional resistance of the guide wire 10 in the catheter 50, and the follow-up of the catheter 50 to the guide wire 10 is achieved. And the operability of the guide wire 10 and the catheter 50 can be further improved.

  Further, in this embodiment, a diameter-reduced portion 42 having a thickness in which the most advanced portions of the core wire 20 and the metal coil 30 are covered with the resin layer 40 is provided further to the distal end side than the enlarged-diameter portion 41 of the guide wire 10. . The axial length A of the reduced diameter portion 42 is preferably 5 to 30 mm.

  If the length of the reduced diameter portion 42 is less than 5 mm, the distal end portion of the guide wire tends to be thick and difficult to insert when attempting to insert the distal end portion of the guide wire into a target branch pipe or the like. If the length of the diameter-reduced portion 42 exceeds 30 mm, the length until the diameter-expanded portion 41 is inserted into the branch pipe or the like becomes longer, so that the effects of the invention are reduced. If the diameter-reduced portion 42 is longer than 30 mm, the diameter-reduced portion 41 does not reach the blood vessel branching portion because it stops on the distal end side of the guide wire, and the effect of the present invention may not be expected.

  As the material of the above-described covering tube 41a and tapered portion 41b, the same resin material as that of the resin layer 40 described above is used. The coated tube 41a is formed by, for example, using a core material having a predetermined length, extruding the resin material such as polyurethane, and covering the core material to form a tube, and then coating the core material. The formed resin can be swelled with a solvent, the core material can be removed, and the solvent contained in the resin can be dried to be molded.

  And the said enlarged diameter part 41 can be shape | molded by the procedure of FIG. 2 (A), (B) and FIG. 3, for example. First, as shown in FIG. 2 (A), a coated tube 41a cut at a predetermined length is provided on the outer periphery of the tip portion of the resin layer 40 where the tip portion 22 having a reduced diameter of the core wire 20 is disposed. Swell with solvent and wear.

  Next, the solvent contained in the coated tube 41a is dried to shrink the coated tube 41a. Then, as shown in FIG. 2B, the covering tube 41 a is tightly covered and coated at a predetermined position on the outer periphery of the resin layer 40.

  And as shown in FIG. 3, the taper part 41b is formed by piling up resin melt | dissolved with the solvent. In this operation, first, a melted resin is included in the tip of a rod-shaped article such as a mandrel. Thereafter, while rotating the core wire 20 covering the resin layer 40 in the axial direction, a mandrel or the like is brought close to the resin to fill both ends of the covering tube 41a. The melted resin is welded to both end portions of the covering tube 41 a and the resin layer 40. Then, by drying the solvent contained in the resin, the taper portion 41b is contracted, the taper portion 41b is fixed to the covering tube 41a, and the enlarged diameter portion 41 is formed.

  The tapered portion 41b may be formed by dissolving both end portions of the covering tube 41a with a solvent.

  As a solvent for swelling the above-described coated tube 41a, for example, when polyurethane is used, dichloromethane, methyl ethyl ketone (MEK), tetrahydrofuran (THF), toluene and the like are preferably used. Moreover, tetrahydrofuran (THF) is used as a solvent for dissolving the resin used when forming the tapered portion 41b, for example. Furthermore, also when melt | dissolving the covering tube 41a and forming the taper part 41b, tetrahydrofuran (THF) is used, for example.

  Furthermore, as a method of forming the taper portion 41b, it is possible to form by injection molding (injection molding), potting molding or dipping molding in which a resin-dissolved liquid is accumulated, or extrusion molding that covers the resin while controlling the discharge amount.

In the guide wire 10 of the present invention, it is preferable to further form a hydrophilic resin film on the surface of the resin layer 40 and the enlarged diameter portion 41. As such a hydrophilic resin film, a resin having a hydrophilic group such as —OH, —CONH ₂ , —COOH, —NH ₂ , —COO ⁻ , —SO ^{3 —} , preferably the resin layer 40 and Those having a functional group capable of binding to the surface of the enlarged diameter portion 41 are preferably employed. Examples of such hydrophilic resins include polyvinyl pyrrolidone and polyethylene glycol.

  In addition, as a bonding structure between the resin layer 40 and the enlarged diameter portion 41 and the hydrophilic resin film, for example, as the resin layer 40 and the enlarged diameter portion 41, a resin in which an isocyanate group remains is used, or the isocyanate group is reactive. When a resin having reactivity with an isocyanate group is used, after further reacting a compound having an isocyanate group, a hydrophilic resin such as polyvinyl pyrrolidone or polyethylene glycol is reacted through these isocyanate groups. A method of bonding is preferably used. Such a method for forming a hydrophilic resin film is described in detail, for example, in JP-A-5-184666, JP-A-7-80078, and JP-A-7-124263. In addition, the outer diameter of the guide wire 10 and the enlarged diameter part 41 in this invention means the outer diameter including the thickness of a hydrophilic resin film, when forming a hydrophilic resin film as mentioned above.

  Next, a method of using the guide wire 10 according to the present invention will be described with an example in which the catheter 50 is inserted into a blood vessel using the guide wire 10 as a guide.

  First, the guide wire 10 is inserted into the blood vessel, and the catheter 50 is inserted along the outer periphery of the guide wire 10. In this insertion, the catheter 50 may be inserted after the guide wire 10 is first inserted to the target treatment site, but the distal end of the guide wire 10 is placed with the catheter 50 disposed on the outer periphery of the guide wire 10. If it advances a little, it can also be performed by repeating the operation of following the catheter 50 and advancing. The guide wire 10 according to the present invention is particularly effective when the catheter 50 is advanced by following the catheter 50 after the distal end of the guide wire 10 is slightly advanced.

  As shown in FIG. 4, according to the guide wire 10 of the present invention, the enlarged diameter portion 41 is partially provided at the distal end portion of the guide wire 10, thereby providing the clearance E with respect to the inner diameter of the catheter 50 by the enlarged diameter portion 41. Can be small. For this reason, rattling in the catheter 50 of the guide wire 10 can be reduced, and the distal end portion of the guide wire 10 can be prevented from being eccentric in the catheter 50.

  Then, as shown in FIG. 5, at the branch portion of the blood vessel, the distal end portion of the guide wire 10 is inserted into the target branch tube 3, the distal end side of the enlarged diameter portion 41 enters the branch tube 3, and the proximal end side is The catheter 50 is placed inside the catheter 50. When the catheter 50 is pushed along the guide wire 10 in this state, the catheter 50 is pushed into the branch tube 3 in a state of being substantially concentrically disposed with the guide wire 10 by the enlarged diameter portion 41 of the guide wire 10. The end portion of the catheter 50 is smoothly introduced into the target branch tube 3 without being caught by the branch portion of the blood vessel.

  Further, since the enlarged diameter portion 41 is partially provided at the distal end portion of the guide wire 10 and there are few portions that slide between the outer periphery of the guide wire 10 and the inner periphery of the catheter 50, the guide wire for the catheter 50 is provided. Ten frictional resistances can be reduced. Moreover, the operativity of the guide wire 10 and the catheter 50 when inserting the catheter 50 can be improved without impairing the flexibility of the distal end portion of the guide wire 10.

Example A guide wire 10 having a shape as shown in FIG. 1 was manufactured by the steps as shown in FIGS. 2A and 2B and FIG.

  First, the coated tube 41a was molded by an extrusion molding machine. That is, a core material having an outer diameter of 0.35 mm and a predetermined length was used. Polyurethane was extruded into the core material, coated with the core material, and formed into a tube shape. Thereafter, the polyurethane was swollen with methyl ethyl ketone (MEK), the core material was removed, and methyl ethyl ketone (MEK) was dried to obtain a coated tube 41a. And this covering tube 41a was cut | disconnected so that length might be set to 31 mm.

  The core wire 20 is made of stainless steel and has an outer diameter of the base portion 21 of 0.29 mm and an overall length of 200 mm. From the most distal side of the core wire 20, the tip portion 22 was formed by processing to 400 mm.

  Next, a metal coil 30 made of a platinum alloy and having an outer diameter of 0.25 mm and a length of 30 mm is disposed on the outer periphery of the core wire 20, and its tip is aligned with the most distal portion 22 b of the core wire 20. The head 52 was formed by welding the materials. And the base end part of the metal coil 30 was welded to the taper part 22a of the core wire 20 by the brazing material 51.

  Next, the resin layer 40 made of polyurethane was coated on the core wire 20 on which the metal coil 30 was mounted with an extrusion molding machine.

  Next, the coated tube 41a was swelled with methyl ethyl ketone (MEK) and disposed on the outer periphery of the distal end portion of the resin layer 40 where the distal end portion 22 with the reduced diameter of the core wire 20 was disposed. Thereafter, the coated tube 41 a was dried to evaporate methyl ethyl ketone (MEK), and the outer periphery of the resin layer 40 was coated.

  Next, a liquid in which polyurethane (THF) is dissolved in polyurethane (hereinafter referred to as liquid G) is contained in the mandrel tip, and the core wire 20 covered with the resin layer 40 is rotated in the axial direction while the coated tube 41a is rotated. Liquid G was filled at both ends. Then, by drying the liquid G and evaporating the solvent, the tapered portion 41b was fixed to the covering tube 41a, and the enlarged diameter portion 41 was formed.

  In the guide wire 10 thus formed, the length B in the axial direction of the enlarged diameter portion 41 was 40 mm, and the outer diameter D thereof was 0.45 mm. Further, the length A in the axial direction of the resin layer 40 having a diameter smaller than that of the enlarged diameter portion 41 on the tip side from the enlarged diameter portion 41 of the resin layer 40 is 10 mm, and the outer diameter C thereof is 0.41 mm. It was.

  When the guide wire 10 thus obtained is used for introducing a catheter having an inner diameter of 0.53 mm as shown in FIG. 5, the catheter 50 can be smoothly inserted, and excellent followability and operability. Was confirmed.

Test Example A catheter followability test was conducted on various guide wires.

  A microcatheter J having an inner diameter of 0.5 mm is inserted into a Y-shaped blood vessel model H as shown in FIG. 7A, and the following sample 1, sample 2, and sample 3 are placed on the inner periphery of the microcatheter J. A guide wire was inserted. Then, the tip of the guide wire protruding from the microcatheter J was inserted into the branch part I of the blood vessel model H, and the guide wire was set to be bent in a J shape. The branch portion I is formed to be inclined at an angle of 30 degrees with respect to the linear portion of the blood vessel model H. The insertion length of the guide wire inserted into the branch part I at this time was L.

  In this state, the insertion length L of the guide wire was changed, the microcatheter J was pushed in the direction of the arrow, and it was confirmed whether or not the guide wire was followed. And the minimum value of the insertion length L of the guide wire when following the guide wire was defined as the followability of the catheter to the guide wire. In this case, the shorter the guide wire insertion length L, the better the followability of the catheter.

Sample 1
A guide wire shown in FIG. 7B was produced. In this guide wire, a metal coil 30 is disposed at the tip end portion of the core wire 20 and is fixed to the core wire 20, and the resin layer 40 is coated on the core wire 20 and the entire metal coil 30. The outer diameter of the resin layer 40 is 0.41 mm. When this guide wire is disposed at the center of the microcatheter J, the clearance from the microcatheter J is 0.12 mm. The length from the distal end to the proximal end of the guide wire is 1800 mm.

Sample 2
A guide wire shown in FIG. 7C was produced. This guide wire is substantially the same as the sample 1 except that the outer diameter of the resin layer 40 is 0.46 mm. When this guide wire is disposed at the center of the microcatheter J, the clearance with the microcatheter J is 0.07 mm.

Sample 3
A guide wire shown in FIG. 7D was produced. This guide wire is provided with an enlarged diameter portion 41 having an outer diameter of 0.46 mm on the outer periphery of the distal end portion of the resin layer 40. In the guide wire 10, the length of the enlarged diameter portion 41 in the axial direction is 40 mm, the distal end side of the enlarged diameter portion 41 of the resin layer 40, and the reduced diameter portion 42 having a smaller diameter than the enlarged diameter portion 41 in the axial direction. The length is 10 mm. Other configurations are the same as those of the sample 1. When this guide wire is arranged at the center of the microcatheter J, the clearance from the microcatheter J in the enlarged diameter portion 41 is 0.07 mm.

  Using the guidewires of Samples 1 to 3 described above, a catheter followability test with respect to the guidewire was performed. The result is shown in FIG.

  As shown in FIG. 8, in the case of the sample 1 having a clearance as large as 0.12 mm with respect to the microcatheter J, in order for the microcatheter J to follow the guidewire, the guidewire must be inserted into the branch part I as much as 20 mm. I must.

  On the other hand, in the case of Sample 2 and Sample 3 where the clearance from the microcatheter J is as small as 0.07 mm, if the guide wire is inserted into the branch part I by 5 mm, the microcatheter J follows the guide wire and guides It can be seen that the followability of the catheter to the wire is improved. That is, it was found that the smaller the clearance, the better the followability of the catheter.

  In the case of the sample 3, the followability of the catheter is the same as the sample 2 although the portion where the outer diameter is large is small. Therefore, in the sample 3, the flexibility of the catheter is maintained while maintaining the flexibility. It can be seen that the followability is improved.

  The present invention is used to guide the distal end of a catheter to a target location when the catheter is inserted into a blood vessel or the like, and can improve the followability of the catheter with respect to the guide wire and can improve the operability of the guide wire and the catheter. It can be used as a guide wire.

It is explanatory drawing which shows one Embodiment of the guide wire of this invention, Comprising: (A) is a perspective view which shows the whole guide wire, (B) is sectional drawing of a guide wire. It is process drawing which shows the formation method of the enlarged diameter part of the guide wire, Comprising: (A) is sectional drawing which shows a covering tube swelling process, (B) is a covering tube contraction process. It is process drawing which shows the formation method of the enlarged diameter part of the guide wire, Comprising: It is sectional drawing which shows a taper part formation process. It is sectional drawing which shows the use condition of the guide wire. It is sectional drawing which shows the state which used the guide wire in the branch part of the blood vessel. It is explanatory drawing which shows the other example of the wire which makes the metal coil in this invention. (A) is explanatory drawing which shows the method of the follow-up test of the catheter in an Example, (B) is explanatory drawing which shows the sample 1 in the follow-up test, (C) shows the sample 2 in the follow-up test Explanatory drawing (D) is explanatory drawing which shows the sample 3 in the follow-up test. It is a graph which shows the measurement result of the follow-up test of the catheter in an Example. It is explanatory drawing which showed the problem in case the clearance between the outer diameter of a guide wire and the inner diameter of a catheter is large, Comprising: (A) is explanatory drawing when the front-end | tip of a catheter is caught in the branch part of the blood vessel, (B) These are explanatory drawings when a catheter does not progress to the target blood vessel.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Guide wire 20 Core wire 22 Tip part 30 Metal coil 40 Resin layer 41 Expanded-diameter part a Radiopaque material arrange | positioned in center part b Superelastic alloy arrange | positioned in outer periphery

Claims (4)

  It has a core wire whose tip is reduced in diameter, and a resin layer that covers the core, and the diameter of the core that has been reduced in diameter is increased partially at the tip of the resin layer. A guide wire provided with a diameter portion.   The guide wire according to claim 1, wherein a length of the enlarged diameter portion in an axial direction of the guide wire is 10 to 100 mm.   3. The resin layer according to claim 1 or 2, wherein the resin layer has a tip portion having a smaller diameter than the enlarged diameter portion on the tip side of the enlarged diameter portion, and the axial length of the tip portion having the small diameter is 5 to 30 mm. Guide wire. A metal coil is attached to the outer periphery of the reduced diameter end portion of the core wire, and the wire material forming the metal coil includes a superelastic alloy disposed on the outer periphery and an X-ray non-uniformity disposed on the center thereof. The guide wire according to any one of claims 1 to 3, comprising a permeable material.

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