JP3971447B1 - Medical guidewire, medical guidewire and microcatheter assembly, and medical guidewire, balloon catheter and guiding catheter assembly - Google Patents

Abstract

[PROBLEMS] To improve the operability by forming a buoyancy chamber inside a tip portion that is likely to hang down due to the action of gravity, and to improve the forward propulsive force by utilizing pressure resistance and specific gravity difference. Offer.
In a coil tip portion of a guide wire, a buoyancy chamber is formed by a brazing portion, an airtight wall, and a resin coating. The resin coating 4 forms a tubular film having an outer diameter smaller than the outer diameter of the coil body 3 in the gap C between the coil wires of the coil body 3 when the coil body 3 is extended in a wet state. To do. As a result, deep insertion in the blood vessel was made possible by the combined use of the buoyancy chamber action and the pressure resistance increasing action. The resin coating 4 includes a first layer 41 having a hydrophobic coating and a second layer 42 having a hydrophilic coating. When the resin coating 4 is wet, the resin coating 4 has a specific gravity from the first layer 41 to the second layer 42 side. By making it smaller, it achieves weight reduction and contributes to the improvement of buoyancy performance.
[Selection] Figure 2

Description

  The present invention relates to a medical guide wire that effectively uses blood flow to improve the reachability of a deep portion into a bent meandering blood vessel.

  When inserting a catheter into a blood vessel, it is necessary to first insert the guide wire into a target part of the human body, and various proposals have been made to smoothly reach the guide wire at a position where insertion is difficult, such as a curved portion.

  Patent Document 1 discloses a resin tube in which an X-ray impermeable metal coil is attached to the end of a core material, a resin tube that wraps the outer periphery of the metal coil, and a guide wire that swells and covers the resin tube. With this configuration, the slipperiness due to the smoothness of the resin tube, the thrombus adhesion prevention, and the pushability at the time of insertion due to the small diameter at the tip of the core material are obtained.

  Patent Document 2 describes a guide wire that has a flexible distal end portion and a highly rigid main body portion, a high X-ray contrast metal is inserted into the distal end portion, and is entirely covered with a resin and exhibits lubrication characteristics when wet. Has been. This proposal aims to improve the operability (push-in and pull-back) of the guide wire with excellent lubricity when wet.

In Patent Document 3, a radiopaque coil is fixed to the distal end portion of the core material, and a resin coating and a hydrophilic coating are partially applied to improve the operability of the guide wire by reducing the friction coefficient of the hand portion. Proposals have been made.
JP 2000-135289 A Japanese Patent Laid-Open No. 4-9162 Utility Model Registration No. 2588582

In the conventional guide wire, the buoyancy in the blood or blood flow in the internal space in the blood vessel, the pressure resistance, and the specific gravity difference are used to effectively improve the operability of the guide wire. There is no thought.
An object of the present invention is to improve operability by positively forming a buoyancy chamber (air chamber) inside a guide wire that is likely to hang down due to the action of gravity. It is an object of the present invention to provide a medical guide wire that can maintain hermeticity even when the gap between them is widened, and has improved forward propulsive force by using pressure resistance and using specific gravity difference.

The medical guide wire according to claim 1, wherein a coil spring having a radiation opaque portion made of a radiation opaque material on a distal end side and a radiation transparent portion made of a radiation transparent material on a rear end side of the radiation opaque portion. And a core material which is inserted into the body of the coil spring and has a small diameter at the front end side and a thick diameter at the rear end side, and the front end of the coil spring body and the front end of the core material are hermetically fixed. periphery of the resin-coated hermetically formed on a rear end portion of the radiopaque portion, the airtight wall for fixing the core material and the coil spring member hermetically provided in the radiopaque portion, the distal end of the helical spring body In a medical guide wire in which a buoyancy chamber is formed by an airtight wall, an airtight wall, and a resin coating , the resin coating is made from a mixture of a hydrophobic polymer and a hydrophilic polymer. Become wet Sometimes, the resin coating made of a mixture, the specific gravity from the inside to the outside is smaller, and, together with a lubricity than when dry state, 50 gaps between coil wires of the wire diameter of the coil wire At the time of extension of the coil spring body that is 100%, a cylindrical film having an outer diameter smaller than the outer diameter of the coil spring body is formed in the gap between the coil strands of the coil spring body. Formed between the inside of the coil spring body and the central diameter portion of the coil spring body, and on the outer periphery, a convex part is formed with the coil wire being a convex part and a cylindrical film is a concave part, and blood flow is formed in the convex part. The forward thrust is improved by the pressure resistance at the time of collision and the spiral vortex generated by the winding form of the coil spring body.

According to this, since the buoyancy chamber selectively formed in the radiopaque portion on the distal end side of the medical guide wire receives buoyancy due to blood or blood flow in the blood vessel, the medical guide wire distal end portion due to gravity is The sagging can be prevented, the stable posture of the distal end portion of the medical guide wire in the blood vessel can be maintained, and the operability of the guide wire is improved.
Even when the radiopaque portion is bent and deformed, and the gap between the coil wires of the coil spring body is widened, the internal film is formed by the cylindrical film formed by extending the wet resin coating. Can be kept airtight without being released to the outside.
Further, the resin coating is made of a mixture of a hydrophobic polymer and a hydrophilic polymer, and the specific gravity of the resin coating made of the mixture decreases from the inside to the outside of the resin layer when wet.
In this case, as a specific embodiment of the mixture, in addition to a mixture obtained by simply mixing a hydrophobic polymer and a hydrophilic polymer, a mixture obtained by mixing a hydrophobic polymer with an adhesive polymer and a hydrophilic polymer, or a hydrophobic polymer A mixture in which a hydrophilic polymer is mixed with a plasticizer added thereto, or a mixture in which a hydrophilic polymer is mixed with a mixture of an adhesive polymer and a plasticizer in a hydrophobic polymer may be used.
By increasing the weight ratio of the hydrophilic polymer having a small specific gravity to the outside where the volume is gradually increasing, the specific gravity from the inside to the outside is reduced so that the outside with a low specific gravity occupies the entire resin coating. Since the ratio increases, it achieves weight reduction and contributes to the improvement of buoyancy performance.
Further, according to this medical guide wire, the coil of the coil spring body has a resin coating when the coil spring body extends such that the gap between the coil strands is 50 to 100% of the wire diameter of the coil strand. A cylindrical film having an outer diameter smaller than the outer diameter of the coil spring body is formed in the gap between the strands. As a result, even when the tip of the guide wire is inverted in a relatively small-diameter blood vessel, a cylindrical film is formed in the gap between the expanded coil wires, so that airtightness can be maintained, and the buoyancy chamber It is possible to participate in the effect of the elastic restoring action by. Further, when the medical guide wire is inserted into the blood vessel, it receives pressure resistance due to blood flow at the convex and concave portions, and can be inserted into the deep portion of the blood vessel.

3. The medical guidewire according to claim 2, wherein the coil spring has a radiation opaque portion made of a radiopaque material on a distal end side and a radiation transparent portion made of a radiation transparent material on a rear end side of the radiation opaque portion. And a core material which is inserted into the body of the coil spring and has a small diameter at the front end side and a thick diameter at the rear end side, and the front end of the coil spring body and the front end of the core material are hermetically fixed. periphery of the resin-coated hermetically formed on a rear end portion of the radiopaque portion, the airtight wall for fixing the core material and the coil spring member hermetically provided in the radiopaque portion, the distal end of the helical spring body In the medical guide wire in which a buoyancy chamber is formed by an airtight wall, an airtight wall, and a resin coating , the resin coating is a hydrophobic coated solid on the outer periphery of the coil spring body. The first is the layer The provided this outside of the first layer providing the second layer is a fluid layer of a hydrophilic coating, when wet state, the resin coating is gravity from the first layer to the second layer side is decreased, and, The gap between the coil strands of the coil spring body when the coil spring body is extended while having a lubricity more than in the dry state and the gap between the coil strands is 50 to 100% of the strand diameter of the coil strand. In addition, a cylindrical film having an outer diameter smaller than the outer diameter of the coil spring body is formed, and the cylindrical film is formed between the inside of the coil spring body and the central diameter portion of the coil spring body, The coil wire is a convex part, the cylindrical film is a concave part, a convex concave part is formed, and the pressure resistance when the blood flow collides with the convex part and the spiral vortex generated by the winding form of the coil spring body , that improves the driving force of forward And features.

According to this, since the buoyancy chamber selectively formed in the radiopaque portion on the distal end side of the medical guide wire receives buoyancy due to blood or blood flow in the blood vessel, the medical guide wire distal end portion due to gravity is The sagging can be prevented, the stable posture of the distal end portion of the medical guide wire in the blood vessel can be maintained, and the operability of the guide wire is improved.
Even when the radiopaque portion is bent and deformed, and the gap between the coil wires of the coil spring body is widened, the internal film is formed by the cylindrical film formed by extending the wet resin coating. Can be kept airtight without being released to the outside.
The resin coating is provided with a first layer , which is a solid layer of hydrophobic coating, on the outer periphery of the coil spring body, and a second layer , which is a fluidized layer of hydrophilic coating , is provided outside the first layer. Since the specific gravity of the resin coating is reduced from the first layer to the second layer side, the proportion of the second layer having a low specific gravity in the entire resin coating increases, so that weight reduction is achieved and buoyancy performance is improved. Contributes to improvement.
Further, according to this medical guide wire, the coil of the coil spring body has a resin coating when the coil spring body extends such that the gap between the coil strands is 50 to 100% of the wire diameter of the coil strand. A cylindrical film having an outer diameter smaller than the outer diameter of the coil spring body is formed in the gap between the strands. As a result, even when the tip of the guide wire is inverted in a relatively small-diameter blood vessel, a cylindrical film is formed in the gap between the expanded coil wires, so that airtightness can be maintained, and the buoyancy chamber It is possible to participate in the effect of the elastic restoring action by. Further, when the medical guide wire is inserted into the blood vessel, it receives pressure resistance due to blood flow at the convex and concave portions, and can be inserted into the deep portion of the blood vessel.

In the medical guide wire according to claim 3, due to the buoyancy chamber, the gas pressure in the buoyancy chamber increases during bending deformation of the radiopaque portion, and the increased internal pressure is restored to the original state by eliminating the bending deformation. Using the elastic restoring force in the returning buoyancy chamber , the forward thrust is improved by the pressure resistance when the blood flow collides with the convex part and the spiral vortex generated by the winding form of the coil spring body It is characterized by that.
According to this, the buoyancy chamber is selectively provided in the radiopaque portion that is easily plastically deformed, and by using the elastic restoring force of the buoyancy chamber, drooping of the radiopaque portion that is prone to plastic deformation and plastic deformation are reduced. Thus, the distal end portion of the medical guide wire can always maintain the initial shape stably.

In the medical guide wire according to claim 4 , the resin coating is made of a mixture of a hydrophobic polymer and a hydrophilic polymer, and a plasticizer is added to the hydrophobic polymer.
According to this, the flexibility of the resin coating can be increased.

In the medical guidewire according to claim 5 , the coil spring body has a radiopaque portion made of a radiopaque material having a springback amount smaller than that of the stainless steel wire on the distal end side.
That is, the radiopaque portion is made of a material that is easily plastically deformed, but the plastic deformation of the radiopaque portion is reduced by the elastic restoring action of the buoyancy chamber.

In the medical guidewire according to claim 6 , the coil spring body has a radiopaque portion made of a radiopaque material having a springback amount smaller than that of the stainless steel wire on the distal end side. The rear end side has a radiation transmitting portion made of a stainless steel wire, and the radiation opaque portion has an outer diameter smaller than that of the radiation transmitting portion.
That is, the radiopaque portion is easily plastically deformed. However, the plastic deformation of the radiopaque portion is reduced by the elastic restoring action of the buoyancy chamber.

In the medical guide wire according to claim 7 , the coil spring body is formed by joining the radiopaque material and the radiolucent material, and forming the wire rod after the diameter reduction drawing process in a coil shape. It is a coil of radiopaque material.
Prior to spiral winding, the radiopaque material and the radiation transparent material are joined together by welding, and after the diameter reduction drawing process, the spiral winding is formed into a coil shape. Solder and brazing material, which were necessary for the structure to be joined, are no longer necessary, achieving weight reduction and contributing to improved buoyancy performance.

In the medical guide wire according to the eighth aspect , the coil spring body is composed of a multi-filament line including at least one radiopaque material at the tip.
As a result, the coil spring body consisting of multiple filaments has a very small gap between the coil strands when bent compared to a single wire coil spring body, so even between severe bending deformations, The cylindrical film of the resin coating formed on is not broken by tension, and the airtight state can be maintained.

In the medical guide wire according to claim 9 , the buoyancy chamber is formed by enclosing a foam having a closed cell structure.
Thereby, by enclosing the foam in the buoyancy chamber, the plastic deformation of the core material and the coil spring body can be effectively prevented, and the elastic restoring force can be increased.

In the medical guide wire according to claim 10 , the buoyancy chamber is formed by enclosing spherical foam beads having a specific gravity of 0.06 to 0.5.
In this case, the expanded beads have few contact points with the adjacent expanded beads and can form many voids convenient for forming the buoyancy chamber, which contributes to the improvement of the buoyancy performance.

The assembly of the medical guidewire and the microcatheter according to claim 11 is composed of a microcatheter and a medical guidewire inserted through the microcatheter, and the outer diameter of the medical guidewire is approximately 0.2032-0. The inner diameter of the microcatheter is approximately 0.280 to 0.80 mm.
According to this assembly, although the medical guide wire has a small diameter, the push-in characteristic of the medical guide wire can be improved by the microcatheter, and the medical guide wire can be inserted deep into the blood vessel. Can contribute to reducing the burden on the patient during surgery.

An assembly of a medical guide wire, a balloon catheter, and a guiding catheter according to claim 12 , wherein the guiding catheter, the medical guide wire inserted through the guiding catheter, and the balloon catheter guided by the guiding catheter are provided. The outer diameter of the medical guide wire is approximately 0.2032-0.254 mm (0.008-0.010 inch), and the inner diameter of the balloon catheter is approximately 0.38-0.90 mm. The inner diameter of the guiding catheter is approximately 1.7 to 2.0 mm.
According to this assembly, using the buoyancy of the buoyancy chamber, the distal end portion of the medical guide wire can be placed on the bloodstream, and can be inserted into the deep blood vessel using the pressure resistance due to the bloodstream. The diameters of the balloon catheter and guiding catheter can be reduced, respectively, to meet the demand for minimally invasive lesions, and to contribute to reducing the burden on patients during surgery.

  The best mode for carrying out the present invention will be described with reference to the examples shown in the drawings.

[Configuration of Example 1]
1 to 6 show Example 1 (corresponding to claims 2 , 3 and 5 to 7 ).
The right side in the figure is the front end side, and the left side is the hand side (rear end) side (even in the figures of the embodiments after the first embodiment, the right side in the figure is the front side and the left side is the hand side unless otherwise indicated. is there).
In Example 1, the medical guide wire is the guide wire 1 for treating a coronary artery occlusion.
The guide wire 1 includes a core material (core) 2 and a coil spring body (hereinafter referred to as a coil body) 3 that is coaxially fitted to the distal end side portion 21 of the core material 2 as a core material distal end portion. A resin coating 4 is formed on the outer periphery of the coil body 3, and a buoyancy chamber 5 is formed at the distal end portion 12 of the guide wire 1.

  The core material 2 is formed of a stainless steel wire, the distal end side is a small distal end side portion 21, and the rear end (hand side) side is a large diameter proximal side portion 22. The distal side portion 21 has a length of about 300 mm, and the proximal side portion 22 has a remaining length of about 1200 mm or about 2700 mm. The front end side portion 21 is a strong taper portion 23, a weak taper portion 24, a cylindrical portion 25, a weak taper portion 26, and a multi-stage flat portion formed so that the plate thickness decreases in three steps from the hand side toward the front end. 27 (see FIG. 1 (e)).

In the multi-stage flat part 27, the curvature radius is different for each step part. That is, the first stage 27a having the smallest plate thickness at the most advanced state, the second stage 27b having a slightly larger thickness than the first stage 27a on the rear end side, and the second stage 27b on the rear end side. The locality radius at the time of bending deformation increases in the order of the third stage 27c having a slightly larger thickness. For this reason, the bending deformation of the distal end side portion 21 is facilitated within a narrow range, and the advantage that the distal end side portion 21 faithfully follows the bent stenotic lesion is obtained.
For example, the thickness of the multi-stage flat portion 27 from the front end side to the proximal side is, in order, 0.040 mm for the first stage 27a, 0.050 mm for the second stage 27b, and 0.063 mm for the third stage 27c. Is set.
In the case of a structure in which the cross-sectional areas of the multistage flat portions 27 are formed substantially the same, the mold is press-molded in a substantially parallel state with respect to the distal end side portion 21. As a result, the fine dimensions of the multi-stage flat portion 27 after press molding are stabilized, and the life of the mold is extended.

  The coil body 3 is formed by welding a platinum wire of a predetermined length and a stainless steel wire and drawing the wire to a predetermined outer diameter, and then spirally winding it into a coil shape. It has an equivalent total length of about 300 mm. The coil body 3 is made of a radiopaque material such as platinum having a coil tip 31 of about 30 mm, and the coil rear portion 32 on the rear side of the coil tip 31 is made of a radiation transmissive material such as stainless steel of about 270 mm.

The coil body 3 is made of a wire material such as gold, silver, or tungsten in addition to platinum as a radiopaque material, and a stainless steel wire is used as the radiation transmissive material because of biocompatibility. A radiopaque material such as a platinum wire is a material that has a small spring back amount and is easily plastically deformed as compared with a stainless steel wire. Therefore, for example, when a wire rod having a wire diameter of 0.072 mm is wound around the coil body 3 having an outer diameter of 0.355 mm, the coil tip portion 31 made of platinum wire has a coil outer diameter of 0 than the coil rear portion 32 made of stainless steel wire. 0.02 mm or less. That is, the coil body 3 has a shape that is reduced in diameter toward the distal end side.
Further, the coil tip portion 31 of the guide wire 1 has a gap C of about 10 to 30% of the outer diameter of the coil wire W of the coil body 3 in order to ensure the flexibility of the tip portion.

The coil body 3 is hermetically fixed in a state where there is no gap between the front end 33 of the core member 2 and the brazing portion 10 (adhering portion) using ball solder (tin) or brazing material, and the rear end 34 is The core member 2 is brazed and fixed to the strong taper portion 23.
A resin coating 4 is applied to the outer periphery of the coil body 3 and the proximal side portion 22 of the core member 2.

In this embodiment, the resin coating 4 has a two-layer structure including a first layer 41 of a hydrophobic coated solid layer and a second layer 42 of a hydrophilic coated fluidized layer exhibiting lubricating characteristics when wet.
Specifically, the solid layer of hydrophobic coating means a solid layer coated with polyurethane, polyether block amide, polyamide, fluororesin, or the like. In addition, the fluidized bed of the hydrophilic coating refers to a fluidized bed that exhibits lubricating properties when wet, and includes polyvinylpyrrolidone, maleic anhydride ethyl ester copolymer, and polyethylene oxide.

In this embodiment, the specific gravity of the second layer 42 is smaller than that of the first layer 41 when wet.
Specifically, if the first layer 41 is made of PTFE, which is a fluororesin, the specific gravity is 2.14 to 2.20. Polyvinyl pyrrolidone, maleic anhydride ethyl ester copolymer, polyethylene oxide, etc. having a specific gravity close to 1 are used. In addition, if polyurethane (specific gravity 1.20 to 1.24) or polyester (specific gravity 1.38) is used for the first layer 41, the second layer 42 has a smaller specific gravity than the above, and when wet, it is almost the same. Polyvinyl pyrrolidone having a specific gravity close to water is used.

  The covering form of the first layer 41 and the second layer 42 may be a form in which the outer periphery of the coil body 3 is covered with the first layer 41 and the second layer 42 in order from the inner layer side as shown in FIG. As shown in FIG. 2B, the first layer 41 is covered over the entire circumference of the coil wire W, and the second layer 42 is covered on the first layer 41 covered on the outer periphery of the coil body 3. Form may be sufficient.

The joint portion of the coil body 3 between a coil front part (radiation opaque part, hereinafter also referred to as a non-transparent coil) 31 and a coil rear part (radiation transmission part, hereinafter also referred to as a transmission coil) 32 is airtight by brazing. A wall 11 is formed.
The hermetic wall 11 is formed by secretly fixing the rear end portion of the coil tip portion 31 and the core material 2 in a state without a gap and using a ball solder (tin) or a brazing material without a gap.
As a result, in the coil tip portion (impermeable coil) 31 of the coil body 3, airtightness is secured by the brazing portion 10, the airtight wall 11 and the resin coating 4, and the buoyancy chamber 5 is formed by the internal space. . That is, the guide wire 1 includes the buoyancy chamber 5 at the distal end portion 12.

In the buoyancy chamber 5, when the gap C between the coil wires is widened due to bending of the guide wire 1 or the like when wet, the resin coating 4 extends and the outer diameter of the coil body 3 extends into the gap C. Since the cylindrical film 43 having a smaller outer diameter is formed, airtightness is maintained.
As described above, the coil tip 31 of the guide wire 1 is about 10 to 30% of the outer diameter of the coil wire W of the coil body 3 between the coil wires in order to ensure the flexibility of the tip portion. The gap C is vacant. Further, the surgeon bends and deforms the coil tip 31 at one or a plurality of sites in a range of about 2 to 7 mm from the most advanced state in order to improve the optionality at the blood vessel bifurcation (FIG. 3). (See (a)). When the lesion stenosis is introduced, the coil body 3 undergoes elastic deformation due to contact with the tube wall or the like.
At that time, the gap C is widened, but as shown in FIG. 3B, the resin coating 4 that has absorbed water and is in a wet state is stretched to form a film 43 continuous with the gap C.

  The continuous film 43 has a spiral cylindrical shape, and the outer diameter of the valley portion is smaller than the outer diameter of the coil body 3 covered with the resin. That is, on the outer periphery of the coil body 3 covered with the resin coating 4, the convex concave portion 6 is formed in which the coil wire W becomes the convex portion 61 and the cylindrical film 43 formed between the coil strands becomes the concave portion 62. The

Generally, the blood vessel inner diameter of the coronary artery is 2 to 4 mm, and the diameter of the coronary artery decreases as it goes deeper. In rare cases, the distal end portion of the guide wire 1 may be inverted at a stenotic lesion.
For example, when the guide wire 1 has an outer diameter d of 0.35 mm and a blood vessel inner diameter D of 2 mm, the difference Δs between the outer arc length L of the coil body 3 arc at the bent portion and the inner arc length m is Δs = L−m = (π × 2 × 1/2) − (π × 1.3 × 1/2) ≈1.099 mm, and the inner arc length m is 2.04 mm (π × 1.3 × 1 / 2). Since this is stretched to 3.139 mm, the length ratio is about 1.53, and the coil body 3 at the bent portion is stretched by about 50% (see FIG. 4A). ).

When the blood vessel inner diameter D is 1.4 mm, Δs becomes Δs = L−m = (π × 1.4 × 1/2) − (π × 0.7 × 1/2) ≈1.099 mm, The arc length m is 1.099 mm (π × 0.7 × 1/2). Since this is extended to 2.198 mm, the length ratio is about 2, and the coil body 3 at the bent portion is extended approximately 100% (see FIG. 4B).
Note that a blood vessel diameter smaller than this is restrained by the inner diameter width of the blood vessel, so that such a phenomenon does not occur.

In the present embodiment, the resin coating 4 is used so that the reversal action rarely occurs in the thin blood vessel as described above and the film 43 is not broken even when the coil body 3 is extended to 50% or 100%. Amount, material is set.
Specifically, in the first layer 41, the plasticity may be increased by adding a plasticizer to the hydrophobic polymer. As the plasticizer, camphor, castor oil, dioctyl phthalate and the like can be used.

[Method for Forming Resin Coating of Example 1]
The resin coating 4 may be formed by any method such as extrusion molding, dipping method, and heat shrink tube forming method, but it is necessary that the buoyancy chamber 5 can be sealed.
In order to hermetically form the buoyancy chamber 5 in the coil body 3, a molding method using a heat shrinkable tube that is pressurized at the time of coating formation and can be formed while the resin does not enter the buoyancy chamber 5 or remains, or A dipping method is desirable. In particular, a dipping method that is not pressurized and does not require a resin weld end treatment is most desirable.

  In this embodiment, the resin coating 4 is formed by first immersing the coil body 3 in a hydrophobic polymer solution (dipping method) and then thermally drying (about 170 ° C. for about 10 minutes). Thereafter, it is formed by dipping in a hydrophilic polymer solution (dipping method (overcoating)) and heat drying (170 ° C., about 10 minutes).

Also, a method of immersing in a hydrophilic polymer solution or applying a hydrophilic polymer after immersing in a solution in which either an adhesive polymer or a plasticizer, or a mixture of both, is mixed in a hydrophobic polymer solution and thermally drying But you can.
In that case, polyurethane, polyester, styrene polybutadiene, acrylic resin, or the like is used as the adhesive polymer. This is to improve the adhesion of the resin coating 4 to the coil body 3.
As the plasticizer, camphor, castor oil, dioctyl phthalate, or the like is used. This is effective for increasing the flexibility of the resin coating 4. In particular, as described above, in order to form the flexible film 43 continuous in the gap C between the coil wires even if the reversal action occurs, and to prevent the film 43 from breaking, It is preferable to add an agent.

[Effects of Example 1]
FIG. 5 is a photograph observing how the cylindrical film 43 is formed in the gap C between the coil wires. 5 (a) and 5 (b), the cylindrical film 43 is formed on the central diameter portion of the coil body 3, (a) is when the wire diameter is 50% elongated, and (b) is the wire diameter. It is a state at the time of 100% elongation. 5 (c) and 5 (d), the cylindrical film 43 is formed inside the coil body 3, (c) is when the wire diameter is 50% elongated, and (d) is the wire diameter. It is a state at the time of 100% elongation.
In either case, a cylindrical film 43 is formed in the gap C between the coil wires, and gas is confined inside.
That is, the guide wire 1 is a cylindrical film formed by extending the wet resin coating 4 even when the coil tip portion 31 is bent and deformed and the gap C between the coil wires is widened. By 43, internal gas is not discharged | emitted outside (the state which confined gas inside), airtightness can be maintained, and the buoyancy chamber 5 can be formed also at the time of bending deformation.

The guide wire 1 of the first embodiment has the following actions and effects by forming such a cylindrical film 43 and forming the buoyancy chamber 5.
B) The posture of the tip 12 in the bloodstream can be stably maintained by the buoyancy chamber 5.
For the purpose of imaging by radiation, the coil body 3 of the guide wire 1 uses platinum at least at the coil tip 31. Platinum has a specific gravity of 21.4, which is approximately 2.14 compared to the specific gravity of stainless steel 7.9. 7 times.
Since the distal end portion 12 of the guide wire 1 is required to be flexible, the core material 2 is reduced in diameter. For this reason, as the specific gravity of the coil tip portion (impermeable coil) 31 is larger, the distal end portion 12 of the guide wire 1 is more likely to hang down in a free state. This tendency is the same also in the blood flow in the blood vessel into which the guide wire 1 is inserted.

When the guide wire 1 having a heavy coil tip 31 is inserted into the blood vessel, the distal end portion 12 of the guide wire 1 hangs down, thereby increasing the degree of contact with the inner wall of the blood vessel, resulting in blood vessel dissociation or intimal detachment. There is a fear. In particular, at the bifurcation position of the blood vessel, this drooping reduces the blood vessel selectivity when the operator inserts the guide wire 1 in a desired direction.
In the present invention, since the buoyancy chamber 5 is provided in the coil tip 31 of the distal end portion 12 of the guide wire 1, the distal end portion 12 is reduced in sag due to buoyancy in the blood flow in the blood vessel, and maintains a constant straight state. can do. In this way, by reducing the sagging of the distal end portion 12 in the bloodstream, contact with the blood vessel wall and friction can be reduced, and the occurrence of dissociation or intimal detachment can be prevented. Then, the distal end portion 12 of the guide wire 1 is placed on the bloodstream and can be smoothly and easily inserted to the deep portion of the bent and meandering blood vessel.

B) By using the elastic restoring force by the buoyancy chamber 5, the shape of the distal end portion 12 can be stably maintained, and insertion into the deep part of the blood vessel becomes possible.
As described above, the coil front portion 31 has a smaller spring back amount than the coil rear portion 32 and is easily plastically deformed. Therefore, the guide wire 1 of the present invention is provided with a sealed buoyancy chamber 5 inside the coil tip portion (impermeable coil) 31 that is easily plastically deformed.

For this reason, the pressure of the gas in the buoyancy chamber 5 increases at the time of bending deformation, and if the bending deformation is eliminated, the original state is restored by the increased internal pressure. That is, by utilizing the elastic restoring force in the buoyancy chamber 5 filled with gas or the like, the plastic deformation of the tip 12 can be reduced, and the tip 12 can always maintain its initial shape stably.
The coil body 3 is reduced in diameter toward a tip 33 due to a difference in springback amount between a radiopaque material such as a platinum wire and a stainless steel wire, and based on the formation of the buoyancy chamber 5. The effect of maintaining the shape stability also occurs. As a result, the passability of the coil tip portion 31 with respect to the stenotic lesion can be further improved.

C) Use of pressure resistance enables insertion into deep blood vessels.
The guide wire 1 of the present invention is used for treating a coronary artery occlusion portion, and is inserted into the coronary artery Ac as shown in FIG. Unlike the aortic arch Aa, the direction of blood flow in the coronary artery Ac is the same as the direction of travel of the guide wire 1, that is, in a tailwind state (see arrow in FIG. 6 (a)).
In such a case, the blood flow collides with the convex portion 61, and the infiltration of the blood flow to the core material side is blocked by the cylindrical film 43, so that the blood flow naturally follows the winding form of the coil body 3. As a result, a spiral vortex is generated (see FIG. 6B).

A propulsive force in the traveling direction can be exerted by the pressure resistance when the blood flow collides with the convex portion 61 and the spiral vortex generated by the winding form of the coil body 3.
Since the present invention forms the buoyancy chamber 5 that does not release the internal gas to the outside as described above, the distal end portion 12 is in a state of floating in the bloodstream due to the action of the buoyancy chamber 5, and the pressure resistance and Due to the spiral vortex, the forward driving force can be exerted, and the insertion into the deep part of the blood vessel is further facilitated.

D) With the guide wire 1 of the present invention, the diameter can be reduced, it is easy to meet the demand for minimally invasive surgery, and the burden on the patient can be reduced.
For example, in diameter expansion treatment of cardiovascular occlusion, that is, percutaneous transvascular coronary angioplasty (PTCA), a guide wire is generally 0.35 mm in outer diameter, and a guiding catheter for introducing a balloon catheter used for diameter expansion treatment is 7F. ~ 8F (inner diameter is 2.3 mm to 2.7 mm) is used. Since the guide wire is required to have various mechanical properties such as torque transmission property and push-in property in order to be inserted into a deep portion in the bent meandering blood vessel, the outer diameter generally used is 0.355 mm.

On the other hand, the guide wire 1 according to the present invention improves the insertion property up to the deep part in the blood vessel by utilizing mechanical characteristics, and uses the buoyancy of the buoyancy chamber 5 to place the blood on the blood flow. It also has the effect of being inserted deep. For this reason, the guide wire 1 of the present invention can reduce the mechanical requirement characteristics such as torque transmission characteristics and reduce the diameter of the guide wire 1 and the core material 2.
For example, when used as an assembly of a guide wire 1, a balloon catheter (not shown), and a guiding catheter (not shown) (corresponding to claim 12 ), the outer diameter of the guide wire 1 is 0.014 inch to 0. From 008 to 0.010 inches (0.355 mm to 0.2032 to 0.254 mm), the guiding catheter for guiding the balloon catheter is 7F to 8F to 5F, 6F (inner diameter 2.3 mm to 2.7 mm) The inner diameter can be reduced to 1.7 mm to 2.0 mm. As a result, it is possible to meet the demand for minimally invasiveness, and the burden on the patient during surgery can be reduced.
In addition, since the inner diameter of the balloon catheter is approximately 0.38 to 0.90 mm and the guiding catheter is used in combination with the balloon catheter to maintain an appropriate clearance with the guide wire 1, By supporting the pushing force of 1 as a reaction force by the guiding catheter and the balloon catheter, the pushing force at the lesion can be exhibited.

  E) Since the outer peripheral portion of the coil body 3 is hermetically sealed by the elastic resin coating 4, even if the tip portion 12 is locally buckled and deformed, the internal pressure of the buoyancy chamber 5 increases and elastically deforms. A restoring force to return to the original is generated by the increased internal pressure. Moreover, the resin coating 4 also has the function of protecting the thin wire core material 2 that is easily plastically deformed.

F) Since the resin coating 4 has a two-layer structure composed of the first layer 41 of the solid layer and the second layer 42 of the fluidized bed, for example, fine pinholes or scratches are generated in the resin coating 4. In this case, by encapsulating the liquid viscous fluid of the second layer 42 over the entire first layer 41, the gas in the buoyancy chamber 5 is prevented from leaking to the outside and the sealed state of the buoyancy chamber 5 is maintained. be able to.
Further, as the liquid viscous fluid of the second layer 42 is encapsulated in the entire first layer 41, friction with the blood vessel wall can be reduced.

G) The resin coating 4 has a structure in which the second layer 42 has a specific gravity smaller than that of the first layer 41, thereby reducing the weight of the guide wire 1 and contributing to an improvement in buoyancy performance.
The reason why this structure can be reduced in weight is that the second layer 42 on the outer layer side is gradually changed in diameter with respect to the first layer 41 on the inner layer side. This is because the ratio of the second layer 42 on the side to the entire coating increases.

[Configuration of Example 2]
FIG. 7 shows a second embodiment (corresponding to claim 1).
In the second and subsequent embodiments, differences from the first embodiment will be mainly described.
In the guide wire 1 of this embodiment, the resin coating 4 has a single layer structure composed of a single layer of a mixture of a hydrophobic polymer and a hydrophilic polymer. In addition, the monolayer made of this mixture has a specific gravity that decreases from the inside to the outside when wet.
Specific embodiments of the mixture include a mixture in which a hydrophobic polymer and a hydrophilic polymer are mixed, a mixture in which a hydrophobic polymer is mixed with an adhesive polymer, and a mixture in which a hydrophilic polymer is mixed, and a hydrophobic polymer added with a plasticizer. There are a mixture in which a hydrophilic polymer is mixed (corresponding to claim 4 ), and a mixture in which a hydrophobic polymer is mixed with an adhesive polymer and a plasticizer and a hydrophilic polymer is mixed (corresponding to claim 4 ).

Examples of the hydrophobic polymer include cellulose ester, a copolymer of polymethyl vinyl ether and maleic anhydride, and cellulose ester is most preferable.
Examples of the hydrophilic polymer include polyvinyl pyrrolidone, maleic anhydride ethyl ester copolymer, and polyethylene oxide.

As the adhesive polymer, polyurethane, polyester, styrene polybutadiene, acrylic resin, or the like is used. This is to improve the adhesion of the resin coating 4 to the coil body 3.
As the plasticizer, camphor, castor oil, dioctyl phthalate, or the like is used. This is effective for increasing the flexibility of the resin coating 4.

[Method for Forming Resin Coating of Example 2]
In this embodiment, the resin coating 4 is formed by immersing the coil body 3 in a mixed solution of a hydrophobic polymer solution and a hydrophilic polymer (dipping method), and then heat drying (170 ° C., about 10 minutes). Formed.
Alternatively, either the adhesive polymer or the plasticizer, or both the adhesive polymer and the plasticizer are mixed in the hydrophobic polymer solution, and then the coil body 3 is immersed in the mixed solution in which the hydrophilic polymer is mixed. (Dipping method), and then heat-dried (170 ° C., about 10 minutes) to form.

[Effects of Example 2]
The resin coating 4 of the present embodiment is configured such that the specific gravity decreases from the inside to the outside when in a wet state. For example, a hydrophobic polymer in which an adhesive polymer is mixed adheres to the outer peripheral portion of the metal coil body 3 such as a radiopaque material, and is high between the hydrophobic polymer and the hydrophilic polymer. Cross-linked or intermolecularly bonded. For this reason, there are many hydrophobic polymer components inside the coil body 3, and many hydrophilic polymer components are arrange | positioned on the outer side.
Thereby, weight reduction of the guide wire 1 is achieved and it contributes to the improvement of buoyancy performance.
The reason why this structure can be reduced in weight is that the outside has a gradually changing diameter with respect to the inside, so if the specific gravity on the outside is reduced, the ratio of the outside having a small specific gravity to the entire coating increases. .

[Configuration of Example 3]
8 and 9 show a third embodiment (corresponding to claim 8 ).
In the guide wire 1 of the present embodiment, the coil body 3 is a multi-strand coil 3 </ b> A composed of a multi-strand including at least one radiopaque material at the coil tip 31.
Specifically, the multi-strand coil 3A is formed in a twisted wire shape having an outer diameter of φ0.35 mm using 3 to 12 wires having a wire diameter of φ0.072 mm (12 in this embodiment shown in FIG. 8). The formed opaque wire R made of at least one (6 in this embodiment) radiopaque material is used for the coil tip portion 31 between the brazing portion 10 and the hermetic wall 11. Thus, the coil tip portion 31 is a radiation opaque portion.

As a manufacturing method of this structure, there are a method in which 3 to 12 wires are wound and formed using a core metal, or a method in which each wire is twisted using a rope twisting machine.
Alternatively, a wire rod having a diameter of 0.072 mm may be formed using 3 to 4 strands, and 3 to 12 wires may be used as the multi-strand coil 3A.

[Effects of Example 3]
The relationship between the coating formation and the buoyancy chamber 5 with the above structure will be described below.
When the bending radius is large, the single wire coil body 3 as in the first embodiment has a large gap C between the coil strands on the side where the curvature radius of the bent portion is large, whereas in the multi-strand coil 3A, The gap C is extremely small (see FIG. 9).
The reason for this can be considered that when the multi-strand coil 3A is bent and deformed, a minute positional shift due to relative slip occurs between the strands, and the large gap C of the single-wire coil body 3 is absorbed. .

In the multi-strand coil 3A using a multi-strand, even if it is bent and deformed, the gap C generated between the coil strands is very small, so that the coating can be broken by tension even for severe bending and deformation. No, the sealed state by the coating can be maintained even during severe bending deformation.
And the function of the buoyancy chamber 5 can be exhibited stably for a long time.

[Configuration of Example 4]
FIG. 10A shows Example 4 (corresponding to claim 9 ).
In this embodiment, the buoyancy chamber 5 is formed by a foam layer 51 having a closed cell structure.
The foam layer 51 is formed by brazing the core material 2 and the coil body 3, then dipping the coil body 3 into a predetermined portion of the coil body 3 and pulling it up, and the foam layer 51 is attached through a jig. The outer diameter is made uniform and left or heated until the foam is solidified. Thereafter, the resin coating 4 is applied to the entire coil body 3 and the core material 2 by the dipping method or the like. A spray-type foam material may be used.

  The foam layer 51 is made of a material obtained by adding a foaming agent to a resin (elastic body). As the resin, a styrene resin such as polyester or a styrene / methacrylic acid copolymer, or a polyolefin resin such as polyethylene or polypropylene can be used. As the foaming agent, known ones such as a volatile foaming agent such as carbon dioxide and a decomposable foaming agent such as ammonium carbonate can be used. As an example, a crosslinked polyolefin foam having a specific gravity of 0.06 to 0.3 is used.

  The foam layer 51 may be obtained by adding a foaming agent to rubber. Silicone rubber or chloroprene rubber is used as the rubber material. As the silicone rubber foaming agent, known foaming agents such as azobisisobutyronitrile can be used. The structure of the foam layer 51 is desirably a closed cell structure rather than an open cell structure in which bubbles are continuous, and the size of the bubbles is desirably fine. As an example, a silicone sponge having a fine cell structure excellent in compression set, low specific gravity (about 0.41) and an average cell diameter of about 110 μm is desirable.

[Effects of Example 4]
The configuration according to the fourth embodiment has the following specific effects.
Since the foam layer 51 is interposed between the core material 2 and the coil body 3, even if the coil tip 31 is pressed by extrusion molding on the outer periphery of the coil body 3 during resin coating molding, There is no resin inside. If the foam layer 51 is a closed cell, the resin can be more effectively prevented from entering the coil body 3 and the buoyancy chamber 5 can be secured. Moreover, since the foam layer 51 is an elastic body, the plastic deformation of the core material 2 and the coil body 3 can be more effectively prevented and the elastic restoring force can be increased.

  Generally, the coil tip portion (impermeable coil) 31 of the coil body 3 is provided with a minute gap between the coil wires in order to give more flexibility. For this reason, at the time of molding of the resin coating 4, the resin of the resin coating 4 enters the gap, thereby hindering flexibility. In the present embodiment, since the foam layer 51 is integrated up to the outer peripheral surface of the coil body 3, this problem can be prevented and the flexibility of the coil tip portion 31 can be stably maintained.

[Configuration of Example 5]
FIG. 10B shows the fifth embodiment (corresponding to claim 10 ). In this embodiment, the buoyancy chamber 5 is formed by the foam beads 53. A synthetic resin foam bead is used as the foam bead 53, and the material shown in Example 4 is formed into a spherical body. As this example, a spherical body having a specific gravity of 0.06 to 0.5 and about 50 to 100 μm is used.

[Effects of Example 5]
In the configuration of the fifth embodiment, the following specific effects can be obtained.
Since the foam beads 53 are a foam and have a spherical structure, for example, unlike the polygonal shape, there are few contact points between the foam beads 53 adjacent to each other, and many voids convenient for forming the buoyancy chamber 5 can be formed.

  Moreover, the buoyancy chamber 5 can be easily formed in the coil tip part (impermeable coil) 31 by using the foam layer 51 of Example 4 as the binder of the foam beads 53. In addition, as a manufacturing method in this case, it can form by the same construction method as Example 4 only by mixing a certain amount of foam beads 53 into the foam layer 51.

FIG. 11 shows a sixth embodiment (corresponding to claim 11 ).
The present embodiment is an assembly 8 of a guide wire 1 and a micro catheter 7, which is composed of a micro catheter 7 and a guide wire 1 inserted through the micro catheter 7.
As already described above, the guide wire 1 of the present invention uses blood flow by using a combination of a buoyancy chamber action and a pressure resistance increasing action, and further by a lightening action by coating formation using a specific gravity difference. The inner deep part can be inserted. For this reason, the guide wire 1 of the present invention can reduce mechanical requirements such as torque transmission characteristics and reduce the diameter of the guide wire 1.
However, in order to pass through a highly stenotic lesion, mechanical characteristics such as sufficient torque transmission characteristics are required, which may be insufficient in the guide wire 1 having a reduced diameter.

Therefore, in this embodiment, the use of the assembly 8 used in combination with the microcatheter 7 made of a flexible tube having a small inner diameter satisfies the requirement of mechanical requirements.
That is, after the distal end portion 12 of the guide wire 1 reaches the highly stenotic lesion S, the microcatheter 7 is inserted to the vicinity of the highly stenotic lesion S, and the rear end of the microcatheter 7 (external, not shown). When the guide wire 1 is pushed while holding, and the microcatheter 7 supports the pushing force as a reaction force in this case, the pushing force can be exerted and the guide wire 1 can be advanced.
The inner diameter of the microcatheter 7 used for this is 0.280 to 0.80 mm and the outer diameter is about 0.4 to 1.2 mm. The outer diameter of the guide wire 1 inserted into the microcatheter 7 is approximately 0.2032-0.254 mm (0.008-0.010 inch).

  This makes it possible to insert deep into the blood vessel, exert a pushing force within the highly stenotic lesion S while having a small diameter, meet the demand for minimally invasiveness, and reduce patient burden during surgery. it can.

[Modification]
12 to 14 show a modification.
In Examples 1-6, the multistage flat part 27 formed so that plate | board thickness may become small over three steps toward the front-end | tip part of the front end side part 21 of the core material 2 (refer FIG.1 (e)). However, it is also possible to provide a multistage reduced diameter portion 28 having a tapered circular cross section formed so that the outer diameter decreases in three steps toward the tip (see FIG. 12C). . Similarly to the multi-stage flat portion 27, the multi-stage reduced-diameter portion 28 also has a different radius of curvature for each step portion. Therefore, the distal-side portion 21 is easily bent and deformed, and the distal-side portion 21 extends along the bent stenosis lesion. The advantage of following faithfully is obtained.

In the guide wire 1 shown in FIG. 13, a multi-row hollow coil body 36 that wraps the proximal side portion 22 of the core material 2 is connected to the proximal side end of the coil rear portion (transmission coil) 32, so The rear end of the hollow coil body 36 is brazed or welded.
At this time, when comparing the example using the solid body on the hand side and the example using the solid core material 2 inside the multi-row hollow coil body, when the outer diameter on the hand side is the same outer diameter, If the multi-row hollow coil body 36 is used, since a concave gap is generated between adjacent strands, the weight can be reduced as compared with the solid core material 2. Further, when the core material 2 is inserted into the blood vessel, blood flows along the multi-row hollow coil body 36, so that a propelling force is applied to the core material 2 to enable deep insertion into the stenotic lesion.

  In the guide wire 1 shown in FIG. 14, the coil is only the opaque coil 31, and the entire guide wire 1 is surrounded by the resin coating 4. The configurations of these modified examples also have the same operations and effects as the first embodiment.

(A) is a side view of a guide wire, (b) is an AA cross-sectional view of (a), (c) is a side view of a core material, and (d) is a front view of (c). (E) is a perspective view of a multistage flat part (Example 1). (A), (b) is side sectional drawing of the guide wire front-end | tip part (Example 1). (A) is a figure explaining the mode of bending of a guide wire front-end | tip part, (b) is a side view of the guide wire at the time of expansion | extension (Example 1). (A), (b) is a figure explaining the expansion | extension degree of a bending part when a guide wire front-end | tip part inverts (Example 1). It is the photograph which observed a mode that the cylindrical film | membrane was formed in the clearance gap between coil strands (Example 1). (A) is explanatory drawing which shows insertion to the coronary artery of a guide wire, (b) is a perspective view of a guide wire, and has shown the relationship between a guide wire and a blood flow (Example 1). (Example 2) which is side sectional drawing of the front-end | tip part of a guide wire. (Example 3) which is a perspective view of a guide wire. (A) shows the bending state of a single-wire coil body (Example 1), (b) is the figure which showed the bending state of the multi-strand coil (Example 3). (A), (b) is side part sectional drawing of the guide wire front-end | tip part (Example 4, 5). (A), (b) is the figure which showed the mode of insertion of the guide wire to the highly stenotic lesion part using the assembly of a guide wire and a microcatheter (Example 6). It is the figure which showed the core material, (a) is a side view, (b) is a right view, (c) is a perspective view of a multistage reduced diameter part (modification). (A) is a side view of a guide wire, (b) is a BB sectional view of (a), (c) is a CC sectional view of (a) (modification). It is a side view of a guide wire (modification).

Explanation of symbols

1 Guide wire (medical guide wire)
10 Brazing part (adhesion part)
DESCRIPTION OF SYMBOLS 11 Airtight wall 12 Tip part 2 Core material 21 Tip side part (tip of core material)
22 Hand side (back end of core)
3 Coil spring body (coil body)
31 Coil tip (radiation opaque part, opaque coil)
32 Coil rear (radiation transmission part, transmission coil)
33 Tip (tip of coil spring body)
3A multi-strand coil 4 resin coating 41 first layer 42 second layer 43 film (tubular film)
5 Buoyancy chamber 51 Foam layer (foam)
53 Foam Beads 6 Convex Concavities 61 Convex Parts 62 Concave Parts 7 Microcatheter 8 Assembly (Assembly of Medical Guide Wire and Microcatheter)
W Coil wire C Clearance (gap between coil wires)
R impervious wire

Claims (12)

A coil spring body having a radiopaque portion made of a radiopaque material on the distal end side, and a radiation transmissive portion made of a radiolucent material on the rear end side of the radiopaque portion;
The coil spring is inserted into the body, and the front end side has a small diameter and the rear end side has a thick core,
Airtightly fixing the tip of the coil spring body and the tip of the core material,
A resin coating is formed on the outer periphery of the coil spring body in an airtight manner ,
An airtight wall for airtightly fixing the core material and the coil spring body is provided at a rear end portion of the radiopaque portion ,
Before SL radiopaque portion, and a fixing portion which is fixed to the tip of the distal end and the core of the coil spring body hermetically, wherein the hermetic wall and, medical guide wire forming the buoyancy chamber by said resin coating In
The resin coating is
Consisting of a mixture of a hydrophobic polymer and a hydrophilic polymer,
In the wet state, the resin coating made of the mixture has a smaller specific gravity from the inside to the outside , and has lubricity as compared to the dry state,
When the coil spring body is extended so that the gap between the coil strands is 50 to 100% of the wire diameter of the coil strand, the gap between the coil strands of the coil spring body Form a cylindrical membrane with an outer diameter smaller than the outer diameter,
The cylindrical film is formed between the center diameter portion of the coil spring body from the inside of the coil spring body,
On the outer periphery, the coil wire is a convex portion, the cylindrical film is a concave portion, a convex concave portion is formed,
A medical guide wire characterized in that forward propulsive force is improved by pressure resistance when blood flow collides with the convex portion and spiral vortex generated by the winding form of the coil spring body . A coil spring body having a radiopaque portion made of a radiopaque material on the distal end side, and a radiation transmissive portion made of a radiolucent material on the rear end side of the radiopaque portion;
The coil spring is inserted into the body, and the front end side has a small diameter and the rear end side has a thick core,
Airtightly fixing the tip of the coil spring body and the tip of the core material,
A resin coating is formed on the outer periphery of the coil spring body in an airtight manner ,
An airtight wall for airtightly fixing the core material and the coil spring body is provided at a rear end portion of the radiopaque portion ,
Before SL radiopaque portion, and a fixing portion which is fixed to the tip of the distal end and the core of the coil spring body hermetically, wherein the hermetic wall and, medical guide wire forming the buoyancy chamber by said resin coating In
The resin coating is provided with a first layer that is a solid layer of hydrophobic coating on the outer periphery of the coil spring body, and a second layer that is a fluidized layer of hydrophilic coating is provided outside the first layer ,
In the wet state, the resin coating has a lower specific gravity from the first layer to the second layer side , and has a lubricity than in the dry state,
When the coil spring body is extended so that the gap between the coil strands is 50 to 100% of the wire diameter of the coil strand, the gap between the coil strands of the coil spring body Form a cylindrical membrane with an outer diameter smaller than the outer diameter,
The cylindrical film is formed between the center diameter portion of the coil spring body from the inside of the coil spring body,
On the outer periphery, the coil wire is a convex portion, the cylindrical film is a concave portion, a convex concave portion is formed,
A medical guide wire characterized in that forward propulsive force is improved by pressure resistance when blood flow collides with the convex portion and spiral vortex generated by the winding form of the coil spring body . The medical guidewire according to claim 1 or 2,
Due to the buoyancy chamber, the gas pressure in the buoyancy chamber increases during bending deformation of the radiopaque portion, and the elastic restoring force in the buoyancy chamber returns the increased internal pressure to the original state by eliminating the bending deformation. A medical device characterized in that the propulsive force forward is improved by the pressure resistance when the blood flow collides with the convex portion and the spiral vortex generated by the winding form of the coil spring body. Guide wire. The medical guidewire according to claim 1 ,
The medical guide wire , wherein the resin coating is made of a mixture of a hydrophobic polymer and a hydrophilic polymer, and a plasticizer is added to the hydrophobic polymer . The medical guidewire according to any one of claims 1 to 4 ,
The coil spring body has the radiopaque portion made of a radiopaque material having a springback amount smaller than that of a stainless steel wire on a distal end side . The medical guidewire according to any one of claims 1 to 4 ,
The coil spring body has the radiopaque portion made of a radiopaque material having a springback amount smaller than that of a stainless steel wire on the tip side, and a stainless steel wire on the rear end side of the radiopaque portion. The radiation transmitting part
The medical guide wire , wherein the radiopaque portion has an outer diameter smaller than that of the radiolucent portion . The medical guidewire according to any one of claims 1 to 6,
The coil spring body is formed by joining a radiopaque material and a radiopaque material, forming a wire after reduced diameter drawing into a coil shape, and the tip side is a coil of a radiopaque material. Medical guide wire. The medical guidewire according to any one of claims 1 to 4 ,
The medical guide wire according to claim 1 , wherein the coil spring body is composed of a multi-filament line including at least one radiopaque material at a distal end portion . The medical guidewire according to any one of claims 1 to 8,
The medical guide wire , wherein the buoyancy chamber is formed by enclosing a foam having a closed cell structure . The medical guidewire according to any one of claims 1 to 8 ,
The medical buoyancy chamber is formed by enclosing spherical foam beads having a specific gravity of 0.06 to 0.5 . An assembly of a medical guidewire and a microcatheter comprising a microcatheter and the medical guidewire according to any one of claims 1 to 10 inserted through the microcatheter,
The outer diameter of the medical guidewire is approximately 0.2032-0.254 mm (0.008-0.010 inches),
An assembly of a medical guide wire and a microcatheter, wherein the inner diameter of the microcatheter is approximately 0.280 to 0.80 mm. A medical guide wire comprising a guiding catheter, the medical guide wire according to any one of claims 1 to 10 inserted through the guiding catheter, and a balloon catheter guided by the guiding catheter. An assembly of a balloon catheter and a guiding catheter,
The outer diameter of the medical guidewire is approximately 0.2032-0.254 mm (0.008-0.010 inches),
The inner diameter of the balloon catheter is approximately 0.38-0.90 mm,
An assembly of a medical guide wire, a balloon catheter, and a guiding catheter, wherein an inner diameter of the guiding catheter is approximately 1.7 to 2.0 mm.

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