JP2012115408A - Guide wire for medical use, manufacturing method thereof, and assembly of guide wire for medical use and microcatheter - Google Patents

Abstract

The leading plug at the distal end of a conventional medical guide wire has a long length in the longitudinal direction of the core wire, so that it cannot be inserted deeply into a lesion with severe bending meandering. In order to enable deep insertion even within such a lesion, there has been a technical problem for shortening and reducing the diameter of the leading plug while securing the separation strength from the core wire of the leading plug.
The same or the same kind of joining member is used to form a leading plug structure consisting of a short and small cured portion and a leading portion, or a coating layer is formed around the core wire using the same or the same kind of joining member as the leading stopper. By using the formed leading plug structure, the leading plug can be shortened and the diameter can be reduced while securing the separation strength from the core wire and the like.
[Selection] Figure 1

Description

  The present invention relates to a medical guide wire with improved mechanical strength characteristics in the joining of a core wire, which is a thin wire, and a coil spring body using a joining member, and in particular, the joining of a leading plug at the tip, and a manufacturing method thereof.

  The leading plug at the tip joint between the core wire of the medical guide wire and the coil spring body must satisfy the safety of the human body in consideration of the ease of deep insertion into the blood vessel and the mechanical strength characteristics of the thin wire. For this reason, various proposals have been made.

  In Patent Document 1, there is a description of stenosis treatment in which the length in the longitudinal direction of the leading plug is numerically limited and passed through the blood vessel wall of the lesioned part. However, the mechanical connection between the core wire of the leading plug and the coil spring body is described. There is no description of any specific technical means of the joining structure that does not reduce the strength but rather improves it.

  In Patent Document 2, when welding a core wire and a coil spring body, the core wire is annealed by welding heat and the tensile strength at break is reduced. Therefore, an enlarged diameter reinforcing portion is formed, and the cross-sectional area of the core wire is increased for annealing. Although there is a description for preventing the mechanical strength from being reduced by the length of the lead plug in the longitudinal direction of the core wire, the mechanical strength characteristics of the lead wire and the coil spring body are improved as described above. No specific technical means for shortening and reducing the diameter of the leading plug are disclosed.

JP 2003-164530 A Japanese Patent Laid-Open No. 2005-6868

In a conventional medical guidewire, when a lead plug is formed by joining a Ni-Ti alloy wire to a coil spring body as a core wire, shape memory characteristics and elastic modulus due to the thermal effect of the core wire of the Ni-Ti alloy wire There is no technical idea about joining using eutectic alloy, which is a joining member for brazing and soldering considering mechanical strength characteristics such as, and a medical guide wire consisting of this joining technology is used for bending blood vessels There is no prior art regarding a technical idea such as a shortened or diameter-reduced leading plug that dramatically improves the ease of deep insertion in a blood vessel that is extremely meandering.
The object of the present invention is to use a Ni-Ti alloy wire that has undergone shape memory treatment on the core wire, without reducing the mechanical strength characteristics and shape memory characteristics, etc. of the thermal effect due to the heat of fusion of the joining member to the core wire. Disclosed is a method for joining a leading plug structure comprising a joining member that joins a coil spring body, and further shortening the diameter and reducing the diameter of the leading plug by making it possible to make a strong connection, thereby causing extremely severe bending of the blood vessel. An object of the present invention is to provide a medical guide wire that can be easily inserted into a blood vessel and can be operated safely by an operator.

According to the first aspect of the present invention, a core wire made of a flexible elongated body, and a coil spring body in which the core wire is inserted into a tip end portion of the core wire are mounted, and a tip end portion of the core wire and the coil spring body is attached. In a medical guide wire with a leading plug,
The core wire is made of a Ni-Ti alloy wire,
The leading plug melts and flows a bonding member into the gap between the coil spring bodies to form a bonded hardened portion bonded to the core wire and bonded to the coil spring body,
Thereafter, the joint cured part is cut from the tip for a predetermined length to form a short and small cured part,
Using a joining member that is the same as or similar to the joining member of the short and hardened portion, a leading plug comprising the short and hardened portion integrated with the leading portion provided at the front end of the short and hardened portion is formed. ,And,
The joining member is a medical guide wire using a eutectic alloy having a melting temperature of 180 ° C. to 450 ° C.
With this configuration, by using a joining member having a constant melting temperature, the short and small hardened portion is prevented while preventing a decrease in shape memory recovery characteristics of the Ni-Ti alloy wire and an increase in residual strain in the stress strain characteristics. And a leading plug structure consisting of the leading portion improves the bonding strength between the core wire of the leading plug and the coil spring body, shortens the leading plug, and deepens in the blood vessel where bending meanders due to diameter reduction are extremely severe It is possible to provide a medical guide wire that can be easily inserted and can be safely operated by an operator.

The invention according to claim 2 is the medical guidewire according to claim 1,
By using the same or the same kind of joining member as that for forming the leading plug at the site where the leading stopper is formed at least at the tip of the core wire, the outer circumference of the core wire is melted for a predetermined length and the joining member is used. Forming a coating layer,
A medical guide wire comprising a lead plug in which the core wire, the short and hardened portion, and the head portion are integrated with each other through the coating layer.
With this configuration, a core wire made of a Ni-Ti alloy wire is used as a core wire to prevent deterioration of the shape memory recovery characteristic of the core wire of the lead plug joint portion where bending fatigue resistance is required, and to prevent an increase in residual strain in the stress strain characteristic. While improving the wettability with the core wire of the joining member, and improving the joint strength of the integrated fixing of the leading stopper consisting of the integration of the short and hardened part and the leading part, shortening and reducing the diameter of the leading stopper Can be achieved.

Invention of Claim 3 is the medical guide wire as described in any one of Claims 1-2,
The inter-line gap of the coil spring body is 5% to 85% of the wire diameter of the coil spring body, and
When the length of the lead plug in the longitudinal direction of the core wire is L (mm) and the wire diameter of the coil spring body is d (mm), the length L of the lead plug in the longitudinal direction of the core wire is 0.190 mm or more. And
A medical guide wire characterized by satisfying a relational expression of 0.078 + 2.05d ≦ L ≦ 0.800.
With this configuration, it is possible to improve the joint strength between the core wire of the lead plug and the coil spring body, and to shorten and reduce the diameter of the lead plug, making it easy to insert deep into blood vessels with severe bending meandering. Can be achieved.

The invention according to claim 4 is the medical guidewire according to claim 3,
The length of the lead plug in the longitudinal direction of the core wire is 0.190 mm or more and 0.600 mm or less from the distal end.
With this configuration, using a medical guide wire with a shorter and smaller diameter leading stopper, a procedure in a blood vessel with extremely severe bending meandering, for example, a retrograde approach described later, is performed in a deep portion in the blood vessel. Easy insertion can be achieved.

Invention of Claim 5 is a medical guide wire as described in any one of Claims 1-4,
The core wire is composed of a Ni-Ti alloy wire which is subjected to wire drawing with a total area reduction of 15% to 65% after annealing and shape memory treatment at 300 ° C to 450 ° C. It is.
With this configuration, it is possible to improve the tensile breaking strength of the core wire while considering the limit of wire drawing of the Ni—Ti alloy wire used for the core wire, and to shorten the lead plug and reduce the diameter.

The invention according to claim 6 is the medical guidewire according to any one of claims 1 to 5,
The coil spring body is made of a composition containing a gold component, or a coil spring body plated with gold, and the lead plug is made of a eutectic alloy having a composition containing a gold component. A medical guide wire characterized by joining both a spring body and the core wire.
By this structure, the wettability with the coil spring body of a joining member can be improved more, and joining strength with the coil sprue ring body of a leading plug can be improved more.

The invention according to claim 7 is the medical guidewire according to any one of claims 1 to 6,
The inter-line gap of the coil spring body from the rear end face of the leading plug to the front end of the intermediate fixing portion is 5% to 30% of the wire diameter of the coil spring body,
The intermediate fixing part has a width of 0.5 mm to 1.5 mm using a joining member that is the same or the same type as the leading plug made of the joining member and is a eutectic alloy having a melting temperature of 180 ° C. to 450 ° C. A donut shape in the shape of a disk,
Fixing the core wire and the coil spring body at the intermediate fixing portion;
The wire diameter of the coil spring body is d (mm), the minimum value of the line gap of the coil spring body is P0 (mm), and the maximum value (mm) of the line gap of the coil spring body is P1 (mm). ), And when the length from the rear end surface of the leading plug to the front end of the intermediate fixing portion is M (mm),
3. A medical guide wire characterized by satisfying a relational expression of 3.25 × (d / P1) ≦ M ≦ 2.625 × (d / P0).
With this configuration, each joint strength of the leading plug and the intermediate fixing portion by the joining member is increased, and while securing the flexibility between the leading plug and the intermediate fixing portion by obtaining an equal line gap of the coil spring body, In addition, the coil spring body is sparse and densely deformed during operation within the lesion, and in the case of “sparse deformation”, the lesion tissue bites into the coil spring body, and in the case of “dense deformation”, the lesion tissue is outside the coil spring body. Thus, the operator can easily grasp the position information of the distal end of the medical guide wire due to a sense of resistance to the hand operation.

According to an eighth aspect of the present invention, there is provided a core wire made of a flexible elongated body, and a coil spring body having the core wire inserted through the distal end portion of the core wire, and attached to the distal end portion of the core wire and the coil spring body. In the manufacturing method of the medical guide wire in which the leading plug is formed,
The core wire is a step of grinding the tip using a Ni-Ti alloy wire,
Inserting the coil spring body by inserting the core wire into the coil spring body; and
Melting a eutectic alloy bonding member having a melting temperature of 180 ° C. to 450 ° C., bonding the tip of the core wire and the tip of the coil spring body, and forming a bonded hardened portion; Cutting the cured portion by a predetermined length to form a short and small cured portion;
Using the same or the same kind of joining member as the short and hardened portion, the leading plug comprising the short and hardened portion integrated with the leading portion provided at the front end of the short and hardened portion is formed. It is a manufacturing method of a medical guide wire characterized by comprising the steps of:
With this configuration, by using a joining member having a constant melting temperature, it is possible to prevent deterioration of the shape memory recovery characteristic of the Ni-Ti alloy wire and prevent increase in residual strain of the stress strain characteristic, and lead wire of the lead plug A medical guide wire that can be operated safely by the surgeon by improving the joint strength between the coil spring body and the lead plug, making it easier to insert deep into the blood vessel where bending and meandering are extremely severe due to shortening and diameter reduction. Can be manufactured.

The invention according to claim 9 is the method for producing the medical guidewire according to claim 8,
By using the same or the same kind of joining member as that for forming the leading plug at the site where the leading stopper is formed at least at the tip of the core wire, the outer circumference of the core wire is melted for a predetermined length and the joining member is used. Comprising the step of forming a coating layer,
A medical guide wire manufacturing method comprising a leading plug in which the core wire, the short and hardened portion, and the head portion are integrated with each other through the coating layer.
With this configuration, the Ni—Ti alloy wire is used as the core wire, while preventing the deterioration of the shape memory recovery characteristic of the core wire at the lead plug joint portion where bending fatigue resistance is required, and the increase of the residual strain in the stress strain characteristic In addition, we improve the wettability with the core wire of the joining member, improve the joint strength of the integrated fixing of the leading stopper consisting of the integration of the short and hardened part and the leading part, shortening the leading stopper and reducing the diameter A guide wire can be manufactured.

The invention according to claim 10 is an assembly of the medical guide wire according to any one of claims 1 to 7 and a microcatheter.
The outer diameter of the medical guidewire is 0.228 mm to 0.254 mm (0.009 inch to 0.010 inch);
The medical guide wire has an inner diameter of 0.28 mm to 0.90 mm and is formed by winding or twisting a plurality of thick and thin wires, and when inserted into the lesion, the outer peripheral portion is pressed and pressed by the lesion. An assembly of a medical guide wire and a microcatheter, wherein the assembly is inserted into a microcatheter composed of a spiral tubular body forming an uneven shape by the thick line and the thin line at least within 300 mm from the distal end side. is there.
With this configuration, by using a joining member having a constant melting temperature, it is possible to obtain a medical guide wire that prevents a decrease in the shape memory recovery characteristic of the Ni-Ti alloy wire and prevents an increase in residual strain in the stress strain characteristic. The assembly using the microcatheter having a high function for supporting the perforation function of the occlusion lesion and the advance reaction force of the medical guide wire can greatly contribute to the treatment of the occlusion lesion.

It is the front view of a medical guide wire and a core wire, and the principal part enlarged view of a core wire. It is a process principal part enlarged view of the joining method of the core wire front-end | tip part of a medical guide wire. It is a characteristic view of the length of a leading stopper and detachment strength. It is a stress-strain characteristic view of a Ni-Ti alloy wire (wide strain range high elasticity type). It is a stress-strain characteristic view of a Ni-Ti alloy wire (work hardening type). It is a use state figure of the guide wire etc. in a lesioned part. It is a state figure of change of hand operation force for grasping tip position information. It is a use state figure of a medical guide wire and a balloon catheter in a lesioned part, a tip part shape state figure of a medical guide wire, and a micro catheter example figure. FIG. 6 is an enlarged view of a main part of a leading plug of Patent Document 2. (Comparative Example 1)

  The best embodiment of the present invention is shown in the drawings and will be described below.

FIG. 1 shows a medical guide wire (hereinafter referred to as a guide wire) 1 (1A, 1B) according to the present invention. Example 1 is used as a guide wire 1A, and a coating layer 44 is formed on the outer peripheral portion of a core wire tip 21 described later. The second embodiment is referred to as a guide wire 1B.
In FIG. 1, a core wire tip portion 21 of a core wire 2 has a coil spring body (hereinafter referred to as a coil body) 3 that is coaxially fitted, and the coil body 3 has radiation on the tip side such as gold, platinum, and tungsten. The rear end side of the opaque material coil 31 is formed of a radiation transparent material coil 32 such as a stainless steel wire.
An intermediate fixing portion 42 and a rear end fixing portion 43 are partially bonded to the core wire distal end portion 21 using the bonding member 4, respectively.
Then, using the joining member 4, a leading plug 41 having a tip end surface having a rounded shape or the like composed of a short and hardened portion 412 and a leading portion 411 is formed by joining the core wire tip 21 and the tip of the coil body 3. The leading end shape of the leading plug 41 may be any of a hemispherical shape, a cylindrical shape, a conical shape toward the leading end side, and the like.

The core wire 2 uses a Ni—Ti alloy wire, which will be described later, about 300 mm from the tip of the core wire tip 21 is a thin wire of about 0.06 mm to 0.200 mm, and the remaining hand portion 22 is about 1200 mm. It consists of a thick line at about 2700mm.
In addition, the small diameter portion of the core wire tip 21 is gradually changed toward the tip, and the cross-sectional shape thereof is a circular cross-section (FIG. 1 (D)), a rectangular cross-section (FIG. 1 (E)), or a rectangular cross-sectional shape. It is good also as a structure (code | symbol (f)) which provided the groove | channel groove | channel orthogonal to a core wire longitudinal direction in the outer peripheral surface.
A resin coating 6 such as fluororesin or urethane resin is formed on the outer peripheral portion of the core wire proximal side 22 of the core wire 2. In particular, urethane resin or the like is formed on the outer peripheral portion of the coil body 3, and fluorine is applied on the outer periphery of the core wire proximal side 22. Resin (PTFE) or the like is coated. In addition, a hydrophilic coating 7 such as polyvinyl pyrrolidone that exhibits lubricating properties when wet is formed on the outer periphery of the resin coating 6 and has an outer diameter of 0.355 mm.

  In addition, the guide wire 1B of Example 2 uses the bonding member 4 to form the coating layer 44 on the outer periphery of the core wire tip portion 21, and is the same as or similar to the bonding member 4 using the coating layer 44. Using the member 4, the tip end surface composed of the short and hardened portion 412 and the leading portion 411 is joined to the leading plug 41 having a rounded shape or the like via the coating layer 44, and together with the core wire tip 21 and the tip of the coil body 3 Join and form. The other structure is the same as that of the first embodiment.

Next, FIG. 2 shows a manufacturing process of the leading plug 41 of the present invention, and a coating layer 44 is formed by the joining member 4 having a film thickness of 0.002 mm to 0.005 mm on the outer periphery of the core wire tip 21 in FIG. (Symbol B), the coil body 3 in which the inter-line gap P of the coil body 3 in the lead plug 41 forming portion is 5% to 85% of the wire diameter of the coil body 3 is externally fitted (symbol C), and the coating layer 44, the joint hardened portion 413 is formed by joining the coil body 3 and the core wire tip 21 using the joining member 4 (reference numeral D), and then cut (H dimension) together with the predetermined long core wire tip 21. Then, the short cured portion 412 (reference numeral E) is used, and the leading portion 411 is joined to the front end of the short cured portion 412 using the same or the same kind of bonding member 4 as the coating layer 44 and the short cured portion 412. The outer diameter of the short and hardened portion 412 and the head portion 411 is 0.34. Forming the head plug 41 mm (code F, D4 dimensions). Before forming the coating layer 44, the coil body 3 may be externally fitted and inserted into the core wire 2 and compressed and deformed to the proximal side, and then the coating layer 44 of the bonding member 4 may be formed on the outer periphery of the core wire tip 21 ( As shown in FIG.
The leading plug 41 composed of the short cured portion 412 and the head portion 411 joined to the tip portion of the coil body 3 may be joined to the core wire tip portion 21 without forming the coating layer 44, or the core wire tip portion. In order to improve the wettability with 21 and improve the bonding strength, bonding may be performed via the coating layer 44.

  The reason why the inter-wire gap P of the coil body 3 is set to 5% to 85% of the wire diameter (d) of the coil body 3 is that the bonding member 4 from the gap of the coil body 3 into the coil body 3 below 5%. When it exceeds 85%, it is difficult to secure the contact area between the joining member 4 and the surface of the coil body 3 with a short length in the longitudinal direction, and the detachment strength described later of the leading plug 41 is taken into consideration. Because. Considering the permeability of the joining member 4 and the separation strength of the lead plug 41 from the core wire 2 and the coil body 3 while ensuring the contact area between the joining member 4 and the coil body 3 with a short length in the longitudinal direction, Preferably, it is 5% to 65%.

Next, FIG. 3 is a view showing the detachment strength of the leading plug 41 when the length of the leading plug 41 of the second embodiment is changed in the longitudinal direction of the core wire. The detachment strength of the leading plug 41 referred to here means that when a tensile load is applied in the longitudinal direction of the core wire, the leading plug 41 is connected to the core wire tip 21 or the coil body 3 (in this embodiment, the radiopaque material coil 31). It means the value of the maximum load when the joint breaks and leaves.
In addition, the illustrated symbol A indicates the relationship between the length L (FIGS. 1 (C) and 2 (A)) in the longitudinal direction of the lead plug 41 of the second embodiment of the present invention and the separation load. In addition, the symbol B shown in the figure has the same structure as the leading plug 8 of Patent Document 2 and is referred to as Comparative Example 1. (Fig. 9)
This is because when the lead plug 8 is formed by welding on the core wire tip portion 21 having a wire diameter of 0.06 mm, the core wire tip portion 21 is annealed by welding heat, so that an enlarged diameter reinforcing portion 811 and a plug base portion 812 are provided. Thus, the cross-sectional area of the wire diameter is increased to ensure the tensile breaking strength of the core wire tip 21. In this case, the total length of the leading plug 8 is 1.0 mm (L dimension in the drawing), and the outer diameter Is 0.345 mm (K dimension in the drawing).
In addition, the reference symbol C indicates that the joining member used for the lead plug is a silver solder having a melting temperature of 605 ° C. to 800 ° C., and is simply applied to the tip end portion of the coil body 3 with respect to the first embodiment of the present invention. A case where a leading plug is formed (a structure that is not the leading plug 41 including the short and hardened portion 412 and the leading portion 411 as in the first and second embodiments of the present invention) and the coating layer 44 is not formed is shown. did.
In Comparative Example 2, the length of the lead plug in the longitudinal direction of the core wire of the lead plug, in which the silver solder naturally flows into the gap between the core wire 2 and the coil body 3 by the capillary phenomenon and is hardened, is set. Is approximately 0.920 mm, and the separation strength at this time is described. The reason for this is that it is difficult to manufacture below 0.900 mm with a manufacturing method in which silver solder flows and hardens naturally. In addition, in FIG. 3, each hatching range described the range of the upper and lower limits of each detachment strength.

Next, the relationship between the length of the leading plug of FIG. 3 and the separation strength will be described.
In general, the lower limit guaranteed value of the detachment strength of the guide plug 41 of the guide wire 1 (1A, 1B) as a cardiovascular treatment device is set to 250 gf, and when this lower limit guaranteed value is 250 gf, Comparative Example 1 An average of 320 gf that exceeds the guaranteed lower limit by about 70 gf is not allowed to greatly exceed this value. (Figure 3)
This is because the comparative example 1 is a pinpoint welding method by TIG welding with the bulging portion 813 at the coil front end welding portion 33 of the coil wire of the coil body 3, and the separation strength from the coil body 3 is the coil strength of the coil body 3. This is because the strength and welding heat (800 ° C. to 900 ° C.) are greatly affected by the bonding strength with one wire and the tensile strength at break. Further, the length of the leading plug 8 (FIG. 9, L dimension) is 1.0 mm.

  On the other hand, the second embodiment of the present invention is indicated by the symbol A in FIG. 3, and the separation strength when the length of the leading plug 41 (FIGS. 1 (C), 2 (A), L dimension) is 0.190 mm. Shows 320 gf above the guaranteed lower limit on average, and is 375 gf on average at 0.250 mm, over 500 gf at 0.50 mm, and 550 gf on average at 0.600 mm, and 0. At 800 mm, the average value is stably 575 gf. As a result, when compared with Comparative Example 1, if the same separation strength 320 gf as Comparative Example 1 is used, the length of the leading plug is reduced to about 0.15 mm or less by using Example 2 of the present invention. Can be greatly shortened. In Comparative Example 2 (reference symbol C), the average value of the detachment strength can exceed the lower limit guaranteed value, but the variation in the detachment strength is large and the lower limit value is ensured while maintaining the lower limit guaranteed value. The length cannot be shortened as in the embodiment of the present invention.

  Next, the reason why the embodiment of the present invention can shorten the length in the longitudinal direction of the core of the lead plug while securing the lower limit value of the separation strength, the structure of the lead plug, the contact structure between the core wire and the lead plug, the joining The thermal characteristics of the members and the engagement structure of the leading plug to the coil body will be described in the following order.

  A. In the embodiment of the present invention, the structure of the leading plug 41 is formed by using the joining member 4 to form the joint hardened portion 413 and then cutting a predetermined length to form a short hardened portion 412, and a leading portion at the front end of the short hardened portion 412. 411 is provided, and the short and hardened part 412 and the head part 411 are that the joining member 4 is the same or uses the same kind of material. Thereby, the short hardening part 412 and the head part 411 are improved in wettability, enable a firmly fixed joining, and lead guide 41 can be shortened. As a specific example of shortening, according to FIG. 3, when the separation strength of the leading plug 41 of Example 2 of the present invention is 320 gf exceeding the guaranteed lower limit by 70 gf, the length L in the longitudinal direction of the leading plug 41 is 0. 190 mm, which corresponds to the length of two wire diameters (0.055 mm) of the radiopaque coil 31 and the inter-line gap S of 5% of the wire diameter of the coil body 3 in FIG. Is the length L of the value of three digits after the decimal point when the length of the head portion 411 and the length (0.078 mm) in the longitudinal direction of the core wire of the head portion 411 are summed.

When this relationship is expressed by a mathematical expression, the length of the lead plug 41 in the longitudinal direction of the core wire is L (mm), and the wire diameter of the coil body 3 is d (mm). L (mm) is 0.190 mm or more from the tip and satisfies the following relational expression (1).
Relational expression (1): 0.078 + 2.05d ≦ L ≦ 0.800
More preferably, it is 0.190 mm or more and 0.600 mm or less. Here, the maximum value of the length of the lead plug 41 in the longitudinal direction of the core wire is set to 0.800 mm or less, even if it is shortened by about 20% compared to Comparative Examples 1 and 2 from FIG. This is because, as a more preferable aspect, the reason why it is set to 0.600 mm or less can secure a separation strength of about 1.7 times as described above even if it is shortened by about 40%. Because. The reason why the length is set to 0.190 mm or more is that the separation strength suddenly decreases at a length of 0.150 mm, so that the safety factor is taken into consideration beyond the standard of separation strength (250 gf) to ensure safety. Because. The effect of shortening the leading plug 41 will be described later.

  And the joining member 4 used by this invention uses the eutectic alloy whose melting temperature is 180 to 450 degreeC. And the eutectic alloy here means a special alloy having the lowest melting point (melting temperature) obtained by changing the component ratio of the alloy, specifically, an alloy material containing gold or silver. The gold-tin alloy material is 80% by weight of gold, the balance is tin and the melting temperature is 280 ° C, the silver-tin alloy is 3.5% silver, the remainder is tin and the melting temperature is 221 ° C, and the gold is 88% by weight. The balance is germanium, the melting temperature is 356 ° C., and the eutectic alloy is composed of silver, tin and indium and the melting temperature is 450 ° C. Table 1 shows typical examples.

  Here, the reason why gold is used as the bonding member 4 is to improve visibility under radioscopy, corrosion resistance, and spreadability. The reason why silver is used is to adjust the melting point and the reason why tin is used. Is to improve the wettability with the core wire 2 or the coil body 3 by lowering the melting point, the reason for using indium is also for improving the wettability, and the reason for using germanium is that of the intermetallic compound This is to suppress the coarsening of the crystal grains and prevent the bonding strength from being lowered. Lead and antimony are not preferable from the viewpoints of incompatibility with the human body and difficulty in workability.

In addition, if a silver solder having a melting temperature of 605 ° C. to 800 ° C. or a gold solder having a melting temperature of 895 ° C. to 1030 ° C. is used, the core wire 2 becomes embrittled or annealed. The tensile strength at break is greatly reduced, and the risk of the leading plug 41 separating from and separating from the joint between the core wire 2 and the coil body 3 increases. Furthermore, the shape memory recovery characteristic is lowered, and the residual strain in the stress strain characteristic is increased.
Then, a gold solder having a melting temperature of about 880 ° C. and having a gold content of 74.5% to 75.5% by weight, silver of 12% to 13% by weight, and other zinc, iron, lead, etc. of 0.15% by weight or less was used. In this case, the same problem as described above also occurs when a silver solder having a melting temperature of 780 ° C. of 72 wt% silver and 28 wt% copper is used.

B. Next, in the embodiment of the present invention, the contact structure between the core wire 2 and the leading plug 41 is that the leading plug 41 is formed on the outer periphery of the core wire 2 via the coating layer 44. This is because a coating layer 44 is formed on the outer periphery of the core wire tip 21 of the core wire 2 in advance by the bonding member 4 before the lead plug 41 is formed, and the same or the same kind of eutectic alloy as the coating layer 44 is bonded. The short curing portion 412 is formed using the member 4, and the leading portion 411 is formed at the front end of the short curing portion 412 using the same or the same type of bonding member 4 as the bonding member 4 that forms the short curing portion 412. This is because the leading plug 41 including the short and hardened portion 412 and the leading portion 411 is formed through the coating layer 44. Even if the coating layer 44 is not formed, if the leading plug 41 composed of the short and hardened portion 412 and the leading portion 411 is formed using the same or the same kind of joining member, the effect of improving the separation strength is achieved. Can be obtained. A more preferred embodiment is to form the coating layer 44.
Here, the joining member 4 which is the same kind of eutectic alloy means that the total of one or two identical composition components is 50% by weight or more. For example, in Table 1, the symbols A1 and A2 are the same, A1 and B1 are different.

As a more preferable aspect, the reason why the coating layer 44 is formed on the core wire tip 21 in advance is that the contact angle between the coating layer 44 and each of the joining members 4 on which the short cured portion 412 and the leading portion 411 are formed is reduced. This is because the wettability can be improved and the bonding strength with the core wire tip 21 can be increased, and the reason why the short cured portion 412 is formed using the same or the same type of bonding member 4 as the coating layer 44, and The reason why the head portion 411 is formed using the same or the same kind of joining member 4 as the short and small cured portion 412 is to improve the wettability and increase the joint strength between them as described above. This is because a high leading plug 41 can be formed. The length N0 of the coating layer 44 is preferably 1 mm to 8 mm, but in order to increase the bending flexibility due to the shortening of the leading plug 41 described later, the length of the core wire 2 in the leading plug 41 is included, and The length N1 from the rear end surface of the leading plug 41 to the proximal side is 2 mm or less, more preferably 0.5 mm to 1 mm or less, most preferably 0 mm, and only the length of the core wire 2 in the leading plug 41 is obtained. This is when the length of the coating layer 44 is reached.
And the effect of shortening the length of the lead plug 41 in the longitudinal direction of the core wire by cutting the joint hardening portion 413 together with the core wire 2 and the coil body 3 to form the short hardening portion 412 will be described later.

  If supplemented, the core wire 2 and the joining member 4 are formed in the same manner as in the formation of the coating layer 44 by performing a partial heat treatment at 180 ° C. to 450 ° C. at the lead plug 41 forming portion of the tip end region (N0) of the core wire 2. The joint strength between the core wire 2 and the leading plug 41 can be increased. More specifically, a partial heat treatment is performed from 180 ° C. to 450 ° C. for 1 second to 60 minutes, preferably from 280 ° C. to 450 ° C. for 1 second to 60 minutes, and from 1 mm to 30 mm (N0 in FIG. 1) from the core wire tip to the hand side. To do. The partial heat treatment means may be an atmosphere heating using hot air as a medium by a heat treatment furnace with a built-in heater, or may be partial heating using conductive heat using a soldering iron as a medium, or may be led by hot air in a nitrogen gas atmosphere. Pinpoint heating with a width of about 1 mm to 2 mm at the joint portion of the stopper 41 may be used, or heating using a high frequency may be used.

C. This is because in the embodiment of the present invention, the joining member 4 is used in consideration of the thermal characteristics of the Ni—Ti alloy wire with respect to the core wire 2.
Specifically, the core wire 2 used in the examples of the present invention was subjected to a wire drawing process with a total area reduction of 15% to 65% using an annealed material, and a shape memory process was performed at 300 ° C. to 450 ° C. A Ni—Ti alloy wire is used, and a eutectic alloy having a melting temperature of 180 ° C. to 450 ° C. is used as the joining member.
Here, the reason why the total area reduction ratio is 15% to 65% is that the wire drawing process is less than 15%, the predetermined tensile breaking strength cannot be obtained, and the Ni-Ti alloy wire exceeds 65%. This is because it is difficult to perform wire drawing, and within this range, a core wire 2 made of a Ni—Ti alloy wire having a tensile breaking strength characteristic of 125 kgf / mm ² to 260 kgf / mm ² can be obtained.

The reason why the eutectic alloy having a melting temperature of 180 ° C. to 450 ° C. is used when the lead plug 41 is formed using, for example, a wide strain range high elasticity Ni—Ti alloy wire (Japanese Patent No. 3547366). The Ni—Ti alloy wire has a residual strain Z (FIG. 4) in the stress-strain characteristic diagram, so that the shape recovery characteristic is inferior. Flexural bending fatigue characteristics are required.
In such a case, since the embodiment of the present invention uses the joining member 4 having the predetermined melting temperature, the increase of the residual strain Z is suppressed, and the shape of the core wire 2 at the joining portion of the leading plug 41 is suppressed. Recovery characteristics can be maintained and improved.
In particular, the joint portion of the lead plug 41 with the core wire 2 is required to have high bending bending fatigue resistance when inserted into a bending meandering blood vessel described later. In FIGS. 4 and 5, symbol H indicates stress hysteresis, and symbol F indicates a yield point.
A more detailed reason for suppressing the increase in the residual strain Z and maintaining / improving the shape recovery characteristic is that the wire diameter of the core wire tip 21 is 0.060 mm, or the core wire 2 is pressed to have a plate width of 0.094 mm. When the rectangular cross section has a plate thickness of 0.030 mm, the heat capacity is small due to the thin wire, and it is easy to be affected by heat, and the core wire is formed by previously forming the coating layer 44 by melting the joining member 4 to the core wire tip 21 in a certain range. 2 and the heating of the bonding member 4 by melting the bonding member 4 and heating the core wire 2 by the formation of the leading plug 41, the same as the low temperature heat treatment to the core wire tip 21 using the heat at the time of melting of the bonding member 4 This is because it can be considered to have produced the effect.

  Further, the joining member 4 is preferably a eutectic alloy having a melting temperature of 180 ° C. to 450 ° C., for example, a gold-tin alloy having a melting heat of 280 ° C. (Table 1, reference A-1), silver having a melting temperature of 450 ° C., Tin and indium alloys (table B-2 in Table 1) are desirable, and those in this range have a high low-temperature heat treatment effect on the core wire using the heat at the time of melting of the eutectic alloy, promote stress-induced martensitic transformation, and There is an effect of suppressing the appearance of the yield point and the lowering of the elastic modulus, which are observed in the heat treatment at a temperature exceeding 450 ° C. In addition, as a Ni-Ti alloy material, Ni contains 50.2 at% to 51.5 at%, the balance is Ni-Ti alloy composed of Ti, Ni contains 49.8 at% to 51.5 at%, and Cr, A Ni-Ti alloy containing 0.1 at% to 2.0 at% of one or more of Fe, V, Al, Cu, Co, and Mo, with the balance being Ti, and 49.0 at Ti. Ni—Ti alloy or the like containing 5% to 51.0 at%, 5 at% to 12 at% of Cu, and the balance being Ni.

  Also in the case where a work hardening type Ni—Ti alloy wire (Japanese Patent Publication No. 6-83726) is used for the core wire 2 that forms and joins the coating layer 44 and the leading plug 41 by the joining member 4 (FIG. 5). In the same manner as described above, an increase in residual strain and a decrease in elastic modulus are suppressed, and the shape recovery characteristics are not deteriorated by heating the core wire 2 when the joining member 4 is melted. The reason for this is that, for example, a linear memory treatment using a work-hardening Ni—Ti alloy wire with a total area reduction of 35% to 50% is from 350 ° C. to 450 ° C. for 10 seconds to 30 seconds. On the other hand, the melting temperature of the joining member 4 is 180 ° C. to 450 ° C., and if the upper limit of the linear memory processing temperature is exceeded, the yield point decreases and the elastic modulus changes greatly, and the shape recovery characteristic decreases. This is because the melting temperature of the joining member 4 used in the embodiment of the invention does not exceed this temperature range. More preferably, the eutectic alloy which is the joining member 4 having a melting temperature of 280 ° C. to 450 ° C. is used.

D. In the embodiment of the present invention, the engagement structure of the leading plug to the coil body or the like forms the short and hardened portion 412 that bites into the inter-line gap P of the coil body 3, and the flat shape of the core wire tip 21 (FIG. This is because of the anchor effect due to an increase in the contact area with the leading plug 41 when () (f)).
Specifically, the gap P between the wires 3 of the coil body 3 in the leading plug 41 (FIGS. 1 (C) and 2 (A)) is provided as a gap between 5% and 85% of the wire diameter, and short and small curing is achieved. The outer diameter D3 of the portion 412 is larger than the coil average diameter D0 of the coil body 3 and is equal to or smaller than the outer diameter D2 of the coil body 3, and the coil wire of the coil body 3 is embedded or embedded in the short and hardened portion 412. It is characterized by that. (Figure 1 (c))
And the contact form with the coil wire of the coil body 3 of the short and small cured portion 412 is a spiral contact form, the contact area with the coil wire surface of the coil body 3 is increased at a short distance in the longitudinal direction, and This is because the detachment strength of the leading plug 41 can be increased by the anchor effect.

Then, the core wire tip 21 increases the contact area with the short and hardened portion 412 by forming the core flat portion 23 by pressing, or by setting the groove 5 on one or both sides of the core flat portion 23, The separation strength between the lead plug 41 and the core wire 2 can be increased due to the effect.
Specifically, the wire diameter of the core wire tip portion 21 is pressed to 0.060 mm to form a rectangular cross-sectional shape having a plate width of 0.094 mm and a plate thickness of 0.030 mm, for example. Can be increased by about 1.32 times.
Then, by forming a plurality of grooves 5 having a depth of about 0.003 mm to 0.005 mm on the surface of the flat core portion 23, the anchor effect is further exhibited. Desirably, the groove 5 is formed in a direction orthogonal to the longitudinal direction of the core wire, and the groove 5 may have a lattice shape, and the coating layer 44 is bonded to each shape of the core flat portion 23. Due to the synergistic effect of improving power, a higher anchor effect can be exhibited. (Fig. 1 (e) (f))

In addition, it is more preferable that the material of the radiopaque material coil 31 to be joined to the lead plug 41 of the coil body 3 includes the same composition component as that of the joining member 4 forming the lead plug 41. Specifically, when the material of the radiopaque material coil 31 is a material containing a gold component or a coil body 3 plated with gold, the bonding member 4 is a eutectic alloy containing a gold component (see Tables 1 to 1). A-4).
The reason for this is to improve the wettability of the bonding member 4 with the coil body 3 at the bonding portion, and to reduce the difference in thermal expansion between the bonding members between the bonding member 4 and the coil body 3. This is to improve the stable bonding strength.

  Next, the effect of obtaining the guide wire 1 provided with the leading plug 41 having a reduced length in the longitudinal direction of the core wire and having a high separation strength will be described below.

By reducing the length of the leading plug 41 in the longitudinal direction of the core wire and using the guide wire 1 provided with the leading plug 41 having high detachment strength, the success rate of treatment for chronic complete obstruction lesions with severe bending meandering has been greatly increased. Can be improved.
FIG. 6 (b) shows an example of conventional completely-occluded lesion treatment as shown in Patent Document 1, and the proximal end 10A on the side close to the aorta of the completely-occluded lesion 10 in the coronary artery is the aorta. It is composed of a harder tissue (fibrous cap) than the closed distal end portion 10B on the far side, and when the guide wire 1 is pushed forward, it is difficult to perforate the completely closed lesioned portion 10 only by bending the distal end portion. It was. (Indicator 1a)
For this reason, the guide wire 1 is repeatedly advanced and retracted from 2 mm to 3 mm, and the difference between the rough feeling of the inner membrane 91 in the blood vessel wall and the resistance feeling of the inner membrane 92 inside the outer membrane 93 sticking is determined at the hand portion. While detecting by the surgeon, the form of the occluded portion of the completely occluded lesion 10 is bypassed from the illustrated code 1b to the illustrated code 1c at the boundary between the intima 91 and the media 92, and to the illustrated code 1d. A completely occluded lesion 10 is penetrated using the guide wire 1 and then dilatation treatment is performed using a balloon catheter or the like.
However, this technique requires an extremely high skill of the surgeon, and it takes a lot of time to acquire the skill.

In recent years, it has been found that even if the closed proximal end portion 10A that directly receives blood flow from the aorta is in a hardened state, the opposite closed distal end portion 10B is in a soft state. A technique of drilling the guide wire 1 from the closed distal end portion 10B side to the closed proximal end portion 10A side (hereinafter referred to as a retrograde approach) has been attempted, and therapeutic results have been dramatically improved. In order to carry out this retrograde approach, it is important to find collateral blood circulation (hereinafter referred to as colateral), which is a blood vessel that devours the developed occluded peripheral tree, and this is referred to as septal (hereinafter referred to as septal). ) It has been found that 11 has developed.
However, this septal collateral blood circulation (hereinafter referred to as septal collateral) 11A is different from the blood vessel that existed before the occurrence of the obstructed lesion, and is thin because it has developed as a self-defense function due to the presence of the obstructed portion. In addition, the blood vessel is in an extremely intense blood vessel with a meandering shape called a corkscrew, just like a corkscrew in a spiral shape. (FIG. 6 (A) code 11B) For example, the cork screw portion 11B has 6 to 8 or more portions that alternately make U-turns with a radius of curvature of about 3 mm to 4 mm within a linear distance of about 50 mm.

The septal collateral 11A has a blood vessel diameter that is greatly different from the coronary artery blood vessel diameter of 3 mm to 4 mm, and is approximately 0.4 mm or less, accounting for 50% to 60% of the whole. Under this condition, the guide wire 1 is pushed forward. In order to proceed, the outer diameter of the tip of the guide wire 1 is 0.4 mm or less, and even in the state of the corkscrew portion 11B that is extremely bent and meandering, a hardened portion at the tip that can follow the bending and meandering is possible. A guide wire 1 having a leading plug with a short length is required.
For this reason, the leading plug length L of Patent Document 2 is approximately 1.0 mm, whereas the leading plug length L of Examples 1 and 2 of the present invention is from 0.190 mm as the shortest preferable shortened mode. It is possible to reduce the length while improving the separation strength from the core wire 2 or the coil body 3 at 0.60 mm.

The outer diameter D2 of the coil body 3 and the outer diameter D4 of the leading plug are both 0.345 mm, and particularly when this septal collateral 11A is used, the outer diameter is desirably 0.345 mm or less, more preferably. Is 0.305 mm or less, more preferably 0.254 mm or less. The reason for this is that septal collateral 11A has a blood vessel diameter of about 0.4 mm or less occupying 50% to 60% of the whole, and in order to enable a small turn that can follow a blood vessel shape that is extremely bent and meandering. As shown in FIG. 8 (b), the distal end portion of the guide wire 1 is bent in advance, the length R of the central axis of the bent shape is sufficiently short with respect to the longitudinal direction, and the radius of curvature is A shape with a sufficiently small r can make a small turn, and the embodiment of the present invention can be shortened while maintaining a high separation strength, which is suitable for this application. In addition, the bent hook-shaped shape is plastically deformed together with the radiopaque material coil 31 by bending deformation due to strong processing exceeding the elastic deformation of the tip portion, and the core wire 2 is a Ni-Ti alloy wire. In addition to processing, shape memory processing may be performed in a bent shape in advance.
And if supplemented, the length N1 from the proximal end face of the leading plug 41 of the coating layer 44 can secure the flexibility of the core wire as it is shorter, and promotes a small turn, more preferably 0.5 mm to 1.0 mm, Most preferably, it is 0 mm.

In order to allow the guide wire 1 to pass through the cork screw portion 11B, the guide wire 1 having a shortened length in the longitudinal direction of the core wire or a reduced outer diameter and a reaction force that can push the guide wire 1 are supported. Therefore, the microcatheter 12 having an inner diameter of 0.28 mm to 0.90 mm inserted into the guiding catheter 14 having an inner diameter of 1.59 mm to 2.00 mm is inserted, and the microcatheter 12 or the microcatheter 12 and the guiding catheter 14 are inserted. And in combination.
And the guide wire 1 which passed the corkscrew part 11B, without passing the inside of the blood vessel wall of an obstruction | occlusion part as shown in patent document 1 is completely obstruct | occluded from the obstruction | occlusion tip end part 10B which consists of soft. The lesioned part 10 can be easily perforated. (FIG. 6 (a) 1e)
Reference numeral 19 in the figure indicates the state of a conventional procedure (an antegrade approach) for perforating the guide wire 101 from the closed proximal end portion 10A side, reference numeral 91 indicates the right coronary artery, reference numeral 92 indicates the left coronary artery, Reference numeral 20 denotes the aorta.

  Next, the effect by providing the leading stopper 41 and the intermediate | middle fixing | fixed part 42 of the Example of this invention is demonstrated below.

By providing the leading plug 41 and the intermediate fixing portion 42, it becomes easy to grasp the position information of the distal end portion of the guide wire 1 in the obstructed lesion portion.
The intermediate fixing portion 42 according to the first and second embodiments of the present invention uses a eutectic alloy having a melting temperature of the same or the same kind of joining member 41 as the joining member 4 and having a width (W) of 0.5 mm. To 1.5 mm and the outer diameter of the disk body 3 is substantially the same as the outer diameter D2 of the coil body 3, and the core wire tip 21 and the coil body 3 are joined to each other. The dimension M from the rear end face of the stopper 41 to the front end of the intermediate fixing portion 42 is a dimension described later (FIG. 1 (C) symbol M), and the gap between the lines (FIG. 1 (C), symbol P) is The wire diameter of the coil body 3 (FIG. 1 (c), symbol d) is 5% to 30%, and the wire diameter of the coil body 3 is 0.06 mm.

The intermediate fixing portion 42 is the same as the joining member 4 of the leading plug 41 or the same kind of joining member is used because the thermal expansion of the intermediate fixing portion 42 and the leading plug 41 and the heating temperature to the core wire are substantially the same. In order to minimize the variation of the position M up to the intermediate fixing portion 42 due to the heat of fusion of the joining member 4, and to obtain a uniform inter-line gap between the coil bodies during this time (position M), and the coating layer 44. The reason why the same or the same kind of bonding member is used is to improve the bonding strength in consideration of wettability when bonding to the core wire via the coating layer 44. In addition, if it supplements, joining which forms the leading plug 41 used when the material of the radiopaque material coil 31 of the coil body 3 consists of a composition containing a gold component, or a coil body plated with gold, or an intermediate fixing portion 42 The member 4 is preferably a joining member made of a eutectic alloy having a composition containing a gold component. Specifically, the joining members shown in Table 1 with reference signs A1 to A4 are used.
The reason for this is that the bonding strength between the coil body 3 and the leading plug 41 or the intermediate fixing part 42 is improved by improving the wettability of the bonding member 4 with the coil body 3 and reducing the thermal expansion difference at the joint. This is to further improve the quality.

  With this configuration, it is easy for the operator to grasp the position information of the distal end portion of the guide wire 1 in the obstructed lesion. That is, the operator's advance / retreat operation of the guide wire 1 while grasping the distal end position within the obstructed lesion is detected while causing the lesion tissue to bite into the inter-line gap of the coil body 3 as seen in Patent Document 1. Yes. That is, with reference to FIGS. 1C and 7, due to the presence of the intermediate fixing portion 42 to which the core wire tip 21 and the coil body 3 are fixed, in the case of a pushing operation, The wire gap P of the coil body 3 on the side of the intermediate fixing portion 42 of the coil body 3 in which the inter-line gap P is provided in advance due to the friction of the coil body 3 becomes narrow and closely adheres (tightly deformed), while the coil on the lead plug 41 side In the body 3, the inter-line gap P is enlarged (sparsely deformed), and the diseased tissue enters therein. On the other hand, in the pulling operation, on the contrary, the wire gap P of the coil body 3 on the leading plug 41 side is narrowed and closely attached, while the inter-line gap of the coil body 3 on the intermediate fixing portion 42 side. P expands, and this time, the lesion tissue enters this, and the pushing and pulling operation alternately causes the lesion tissue to enter the leading plug 41 side and the intermediate fixing portion 42 side. If the pushing operation force is a and the pulling operation force is b, the result is as shown in FIG. Then, the operator can grasp the tip position information of the guide wire 1 in the obstructed lesion by the difference U in resistance feeling of the reversal action of the pushing and pulling operation force. In FIG. 7A, there is almost no difference in resistance U of the reversal action. For example, it is a state diagram of a pushing operation and a pulling operation when the gap between the wires is less than 5% of the wire diameter of the coil body 3.

The advance / retreat operation of the guide wire 1 in the obstructed lesion is approximately 2 mm to 3 mm and an average of 2.5 mm. In such a case, when the wire diameter of the coil body 3 is 0.06 mm and the gap between the coil wires is 5% to 30% of the wire diameter of the coil body 3, the distance of 2.5 mm to be advanced and retracted by the total gap between the coil wires. In order to ensure the position, the position M of the intermediate fixing portion 42 corresponds to the length of one turn including the wire diameter of the coil body 3 and the gap between the coil wires, and the length of the forward / backward operation (2.5 mm). About 11 mm {(0.06 + 0.06 × 0.30) × 2.5 ÷ (0.06 × 0.30) which is a value obtained by multiplying the maximum value or the minimum value of the gap between lines to be wound )} To about 53 mm {(0.06 + 0.06 × 0.05) × 2.5 ÷ (0.06 × 0.05)}, and a more preferable gap between wires is 8% of the wire diameter of the coil body 3 30% to 30%, the position M to the intermediate fixing portion 42 is about 11 mm to about 34 mm. In consideration of the passage through the corkscrew portion 11B, when the preferable inter-line gap is 8% to 20% of the wire diameter of the coil body 3, the position M to the intermediate fixing portion 42 is about 15 mm to about 34 mm. It is.
The length M from the rear end face of the leading plug 41 to the front end of the intermediate fixing portion 42 is obtained by generalizing the above calculation method when the inter-wire gap of the coil body 3 is 5% to 30% of the wire diameter of the coil body 3. Thus, the following relational expression (1) between the wire diameter of the coil body and the gap between the coil wires is satisfied.
Relational expression (1): 3.25 × (d / P1) ≦ M ≦ 2.625 × (d / P0)
M: Length from the rear end surface of the leading plug to the front end of the intermediate fixing portion 42 (mm)
d: Wire diameter of coil body (mm) P0: Minimum value of gap between coil wires (mm)
P1: Maximum value of gap between coil wires (mm)
Here, the gap between the coil wires is set to 5% to 30%, and more preferably 8% to 20%. In this range, the surgeon can recognize the difference in resistance feeling of the reversal action and bend This is because the passability of the meandering corkscrew portion 11B is taken into consideration. In the above relational expression, the minimum value of the position M to the intermediate fixed part is
The calculation was performed as (d + d × 0.30) × 2.5 / P1 = 3.25 × (d / P1), and the maximum value was calculated and generalized in the same manner as described above.

The joining member 4 used for forming the lead plug 41 prevents the joining strength from being lowered due to the progress of corrosion, prevents blackening, and further prevents the visibility from being lowered under radioscopy by reducing the diameter using the septal collateral 11A. From the viewpoint, it is desirable to use a eutectic alloy containing a gold component.
This is because the guide wire 1 is immersed in physiological saline before the procedure. For example, when the joining member 4 made of a silver-based eutectic alloy is used for the lead plug 41, silver sulfide or the like is immersed within about 1 hour. Or the formation of silver chloride, and the blackening of the silver compound begins due to the photosensitivity of the silver compound, and the blackening further progresses with the passage of time, increasing the corrosion and lowering the bonding strength. In addition, the guide wire 1 that allows the corkscrew portion 11B to pass therethrough has a reduced diameter, and thus it is necessary to prevent the visibility from being lowered.

  Next, the method for manufacturing the guide wire of the present invention will be described below.

The guide wire manufacturing method of the present invention includes:
A medical guide comprising a core wire composed of a flexible elongated body, a coil spring body having the core wire inserted through the distal end portion of the core wire, and a leading plug formed at the distal end portion of the core wire and the coil spring body. In the wire manufacturing method,
The core wire is a step of grinding the tip using a Ni-Ti alloy wire,
Inserting the coil spring body by inserting the core wire into the coil spring body; and
Melting a eutectic alloy bonding member having a melting temperature of 180 ° C. to 450 ° C., bonding the tip of the core wire and the tip of the coil spring body, and forming a bonded hardened portion; Cutting the cured portion by a predetermined length to form a short and small cured portion;
Using the same or the same kind of joining member as the short and hardened portion, the leading plug comprising the short and hardened portion integrated with the leading portion provided at the front end of the short and hardened portion is formed. It is a manufacturing method of a medical guide wire characterized by comprising the steps of:
With this configuration, by using a joining member having a constant melting temperature, it is possible to prevent the deterioration of the shape memory recovery characteristic of the Ni—Ti alloy wire and to prevent the residual strain from being increased in the stress strain characteristic. Medical use that improves the joint strength between the core wire 2 and the coil body 3 and facilitates deep insertion in a blood vessel where bending meanders are extremely severe due to shortening and diameter reduction of the leading plug 41, allowing the operator to operate safely. A guide wire can be manufactured.

According to another method of manufacturing the guide wire of the present invention, in the guide wire manufacturing method, after the step of grinding the core wire tip portion, at least a portion of the core wire tip portion where the leading plug is formed is 180. A medical guide wire manufacturing method comprising a partial heat treatment step at 1 to 60 minutes at a temperature of from 450C to 450C.
With this configuration, it is possible to manufacture the guide wire 1 that improves the tensile strength at break of the core wire by the strong wire drawing and improves the wettability of the bonding member 4 with the core wire 2 to increase the bonding strength.

And, another method for manufacturing the guide wire of the present invention is the method for manufacturing the guide wire,
By using the same or the same kind of joining member as that for forming the leading plug at the site where the leading stopper is formed at least at the tip of the core wire, the outer circumference of the core wire is melted for a predetermined length and the joining member is used. Comprising the step of forming a coating layer,
A medical guide wire manufacturing method comprising a leading plug in which the core wire, the short and hardened portion, and the head portion are integrated with each other through the coating layer.
With this configuration, a Ni-Ti alloy wire is used for the core wire 2 to prevent deterioration of the shape memory recovery characteristic of the core wire 2 at the joint portion of the lead plug 41 where bending fatigue resistance is required, and to prevent an increase in residual strain in the stress strain characteristic. In addition, the wettability of the joining member 4 with the core wire 2 is further improved, and the joining strength of the integrated fixing of the leading plug 41 formed by integrating the short and hardened portion 412 and the leading portion 411 is improved. It is possible to manufacture a guide wire 1 with a shorter and smaller diameter. In addition, if supplementarily, the process of forming the coating layer 44 by the joining member 4 in the outer periphery of the said core wire 2 can be considered as one embodiment of the partial heat treatment process for 1 second to 60 seconds.

  In addition, in addition to the partial heat treatment step, another method for improving the wettability between the core wire 2 of the Ni—Ti alloy wire and the bonding member 4 is to remove the oxide film using electrolytic polishing or sandpaper. As a result, the bondability of the bonding member 4 can be improved. In addition, when sandpaper or the like is used, in addition to the above effects, polishing in the major axis direction of the core wire tip 21 flattens the machining flaw in the direction perpendicular to the major axis due to the coreless grinding process, and starts the processing flaw. It also has another function and effect of preventing repeated cutting and improving repeated bending fatigue resistance.

Next, by using the guide wire 1 having the structure of the leading plug 41 of the present invention, the guide wire 1 can be reduced in diameter.
For example, the outer diameter of the proximal portion 22 of the guide wire 1 and the coil body 3 is changed from 0.355 mm to 0.254 mm (0.014 inch to 0.010 inch), and the core wire 2 and the coil body 3 by the joining member 4 By using the structure of the leading plug 41 that enables strong bonding, the outer diameter (D4) forming the leading plug 41 and the outer diameter (D2) of the coil body 3 are reduced to 0.228 mm (0.009 inch). Diameter can be increased.
Then, the guide wire 1 is inserted into the microcatheter 12, and the guide wire 1 and the microcatheter 12 are inserted into the guiding catheter 14. In such a case, the guiding catheter 14 changes from 7F to 8F to 5F to 6F (inner diameter 2.3 mm to 2.7 mm to inner diameter 1.59 mm to 2.00 mm) following the narrowing of the guide wire 1. The diameter can be reduced together with the microcatheter 12 (the inner diameter is 0.28 mm to 0.90 mm) inserted into the catheter.
As a result, the retrograde approach procedure using Septal Collatellal 11A can be made extremely easy, and the success rate of treatment in the chronic total occlusion lesion 10 can be drastically improved, and a request for minimally invasiveness is required. As a result, the burden on the patient can be greatly reduced. In addition, as shown in FIG. 6 (a), the microcatheter 12 is introduced together with the guidewire 1 and supported by the microcatheter 12 so as to support the reaction force of the force pushing the guidewire 1 forward. The forward driving force of 1 can be exhibited.

The microcatheter 12 that receives a reaction force that supports the advancing force that strongly pushes the guide wire 1 is a multilayer resin tube (inner layer PTFE, outer layer polyamide, etc.) structure, or a metal wire braid is interposed in the multilayer resin tube body. In addition to the above structure, the tip portion 17 is made of a spiral tube body in which a tip portion 17 of a substantially conical shape made of metal or synthetic resin is fixed, and a plurality of metal wire round wires are formed into a multi-row coil body, A flexible hollow tube comprising a helical tube 15 having a metallic tip that allows perforation in a lesion or a tapered cone-shaped resin tip having high penetration into a bent meandering lesion. Is desirable.
In particular, in a retrograde approach procedure using Septal Collateral 11A, when the blood vessel diameter is small and bending meandering is severe, the spiral of a multi-strand coil body in which the outer peripheral portion forms a rounded uneven shape. As shown in FIG. 8 (c), the tubular body is desirable, and among the multi-strands, for example, one or two thick lines 16A having a line diameter of 0.11 mm to 0.18 mm, and a line diameter Is formed by winding or twisting two to eight fine wires 16B of 0.06 mm to 0.10 mm, or by providing two or more pairs of two to four fine wires for one thick wire. It is the structure of the spiral tubular body 15 in which the metal wire is adjacently contacted and wound or formed by twisting to form a hollow shape with a hollow outer periphery.
This is because the blood vessel wall and the convex and concave portions of the outer peripheral portion of the multi-strip line are in contact with each other to prevent sliding movement, and the force that supports the reaction force of the guide wire 1 to be pushed forward is high. In addition, the thick wire contacts the blood vessel wall earlier, and if it is rotated once in that state, it moves only with the twisted pitch of the thick wire, and the travel distance in one rotation becomes longer. As a result, the guide wire 1 This is because the advancing / retreating operation as an assembly including the is accelerated. In addition, the structure which forms the said unevenness in the front-end | tip part of the outer peripheral part, or the whole, or the said unevenness in at least one part (300 mm from the front-end | tip) of an outer peripheral part by the compression / pressing action from a blood vessel wall at the time of insertion in a stenosis part May be a structure in which a thin resin tube body 18A is provided on the outer peripheral portion and a similar resin tube body 18B is provided on the inner side.

Then, by using the guide wire 1 having the structure of the leading plug 41 of the present invention, the diameter can be reduced as described above. Then, the guide wire 1 having a reduced diameter is inserted into the balloon catheter 13, and the guide wire 1 and the balloon catheter 13 are inserted into the guiding catheter 14. In such a case, following the narrowing of the guide wire 1, the guiding catheter 14 is changed from 7F to 8F to 5F to 6F (inner diameter 2.3 mm to 2.7 mm to inner diameter 1.59 mm to 2.00 mm). The diameter can be reduced along with the balloon catheter 13 (inner diameter 0.28 mm to 0.90 mm) inserted therein.
As a result, in the case of the retrograde approach procedure using Septal Collateral 11A, as described above, the success rate of treatment of chronic total occlusion lesions is dramatically improved, and further, the demand for minimally invasiveness is met. Can greatly contribute to mitigation. If supplemented, the balloon catheter 13 introduced together with the guide wire 1 is expanded in front of the cork screw portion 11B in order to increase the forward pushing force of the guide wire 1 entering the cork screw portion 11B of the septal collatellal 11A. Thus, the propulsion force of the guide wire 1 can be exerted by supporting the reaction force of the guide wire 1 that is about to move forward and contact the blood vessel wall. In such a case, the expanded outer diameter 13B of the balloon portion 13A of the balloon catheter 13 is desirably 1.2 mm to 1.8 mm. (Fig. 8 (A))

  In addition, if the diameter is reduced, the guide wire 1 and the balloon catheter 13 can be inserted into the guiding catheter 14 as a pair to facilitate the kissing procedure. The kissing technique here refers to a guide wire and a balloon catheter that are inserted into two sets of guiding catheters 14 as a set to simultaneously expand the balloon portions of the two balloon catheters in the bifurcation lesion of the blood vessel, This refers to a technique that simultaneously expands the blood vessel inner diameter of two branching stenotic lesions.

(The invention's effect)
As described above, the medical guide wire according to the present invention has the structure of a leading plug composed of a short hardened portion and a leading portion using a joining member made of the same or the same material, and thereby the longitudinal direction of the core of the leading plug. The overall length can be reduced by shortening the length and further reducing the outer diameter.
Furthermore, it comprises a leading plug structure in which a coating layer is formed on the outer periphery of the core wire using a bonding member made of the same or the same material as the leading plug, and improves the wettability between the bonding member forming the leading plug and the core wire. Thus, the firm coupling between the core wire and the coil body can be further improved.

  In addition, a guide wire with a leading plug structure that enables the core wire and the coil body to be tightly coupled while being shortened and reduced in diameter can be easily advanced forward even in severely meandering lesions. In addition, by using it as an assembly with a microcatheter consisting of a spiral tube that can strongly support the forward force of the guide wire forward, a new lesion treatment technique such as a retrograde approach is possible. Thus, it provides a new technical idea that can dramatically improve the success rate of chronic complete obstruction lesion treatment. There are the above various effects.

1 Guide wire (medical guide wire)
2 core wire
21 Core wire tip (core wire) 3 Coil spring body (coil body)
31 Radiopaque coil
32 Radiation transparent material coil
4 Joining members
41 Leading stopper 411 Top
412 Short cured part
413 Hardened joint
42 Intermediate fixing part
43 Rear end fixing part
44 Coating layer
5 groove
6 Resin coating
7 Hydrophilic coating
8 Leading plug (Patent Document 2)

Claims (10)

A medical guide comprising a core wire composed of a flexible elongated body, a coil spring body having the core wire inserted through the distal end portion of the core wire, and a leading plug formed at the distal end portion of the core wire and the coil spring body. In the wire
The core wire is made of a Ni-Ti alloy wire,
The leading plug melts and flows a bonding member into the gap between the coil spring bodies to form a bonded hardened portion bonded to the core wire and bonded to the coil spring body,
Thereafter, the joint cured part is cut from the tip for a predetermined length to form a short and small cured part,
Using a joining member that is the same as or similar to the joining member of the short and hardened portion, a leading plug comprising the short and hardened portion integrated with the leading portion provided at the front end of the short and hardened portion is formed. ,And,
A medical guide wire, wherein the joining member is made of a eutectic alloy having a melting temperature of 180 ° C to 450 ° C. The medical guidewire according to claim 1, wherein
By using the same or the same kind of joining member as that for forming the leading plug at the site where the leading stopper is formed at least at the tip of the core wire, the outer circumference of the core wire is melted for a predetermined length and the joining member is used. Forming a coating layer,
A medical guide wire comprising a leading plug in which the core wire, the short and hardened portion, and the head portion are integrated with each other through the coating layer. The medical guidewire according to any one of claims 1 to 2,
The inter-line gap of the coil spring body is 5% to 85% of the wire diameter of the coil spring body, and
When the length of the lead plug in the longitudinal direction of the core wire is L (mm) and the wire diameter of the coil spring body is d (mm), the length L of the lead plug in the longitudinal direction of the core wire is 0.190 mm or more. And satisfying a relational expression of 0.078 + 2.05d ≦ L ≦ 0.800. The medical guidewire according to claim 3,
The length of the lead plug in the longitudinal direction of the core wire is 0.190 mm or more and 0.600 mm or less from the distal end. The medical guidewire according to any one of claims 1 to 4,
The core wire is composed of a Ni-Ti alloy wire which is subjected to wire drawing with a total area reduction of 15% to 65% after annealing and shape memory treatment at 300 ° C to 450 ° C. . The medical guide wire according to any one of claims 1 to 5,
The coil spring body is made of a composition containing a gold component, or a coil spring body plated with gold, and the lead plug is made of a eutectic alloy having a composition containing a gold component. A medical guide wire characterized by joining both a spring body and the core wire. The medical guide wire according to any one of claims 1 to 6,
The inter-line gap of the coil spring body from the rear end face of the leading plug to the front end of the intermediate fixing portion is 5% to 30% of the wire diameter of the coil spring body,
The intermediate fixing part has a width of 0.5 mm to 1.5 mm using a joining member that is the same or the same type as the leading plug made of the joining member and is a eutectic alloy having a melting temperature of 180 ° C. to 450 ° C. A donut shape in the shape of a disk,
Fixing the core wire and the coil spring body at the intermediate fixing portion;
The wire diameter of the coil spring body is d (mm), the minimum value of the line gap of the coil spring body is P0 (mm), and the maximum value (mm) of the line gap of the coil spring body is P1 (mm). ), And when the length from the rear end surface of the leading plug to the front end of the intermediate fixing portion is M (mm),
3. A medical guide wire characterized by satisfying a relational expression of 3.25 × (d / P1) ≦ M ≦ 2.625 × (d / P0). A medical guide comprising a core wire composed of a flexible elongated body, a coil spring body having the core wire inserted through the distal end portion of the core wire, and a leading plug formed at the distal end portion of the core wire and the coil spring body. In the wire manufacturing method,
The core wire is a step of grinding the tip using a Ni-Ti alloy wire,
Inserting the coil spring body by inserting the core wire into the coil spring body; and
Melting a eutectic alloy bonding member having a melting temperature of 180 ° C. to 450 ° C., bonding the tip of the core wire and the tip of the coil spring body, and forming a bonded hardened portion; Cutting the cured portion by a predetermined length to form a short and small cured portion;
Using the same or the same kind of joining member as the short and hardened portion, the leading plug comprising the short and hardened portion integrated with the leading portion provided at the front end of the short and hardened portion is formed. The manufacturing method of the medical guide wire characterized by comprising the process to do. In the manufacturing method of the medical guide wire of Claim 8,
By using the same or the same kind of joining member as that for forming the leading plug at the site where the leading stopper is formed at least at the tip of the core wire, the outer circumference of the core wire is melted for a predetermined length and the joining member is used. Comprising the step of forming a coating layer,
A medical guide wire manufacturing method comprising: a leading plug in which the core wire, the short and hardened portion, and the head portion are integrated with each other through the coating layer. In the assembly of the medical guide wire according to any one of claims 1 to 7 and a microcatheter,
The outer diameter of the medical guidewire is 0.228 mm to 0.254 mm (0.009 inch to 0.010 inch);
The medical guide wire has an inner diameter of 0.28 mm to 0.90 mm and is formed by winding or twisting a plurality of thick and thin wires, and when inserted into the lesion, the outer peripheral portion is pressed and pressed by the lesion. An assembly of a medical guide wire and a microcatheter, wherein the assembly is inserted into a microcatheter formed of a spiral tube forming at least 300 mm from the distal end side and forming an uneven shape by the thick line and the thin line.

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