JPH09182800A - Guidewire for medical treatment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a guidewire for medical treatment, whose contracted tip part of a superfine stainless steel wire main body is fitted with a coil spring, capable of almost completely preventing risk of remaining in the blood vessel, which is caused by breaking of the tip part by load by drawing and twisting of the wire main body upon drawing off the blood vessel, and improving performance and safety. SOLUTION: Between a contracted part 4 of a wire main body 2 and a coilspring 5, clearance 6 is provided to install a safety wire 10 therein, which consists of twisted fine wires and forms a gently serpentine shape in the lengthwise direction. The front tip 9 of the safety wire 10 is fixed to the tip head 3 of the wire main body 2, and the back tip 11 of it is connected to a soldering part 12 located at a tapered position of the primary contracted part 4A.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a medical guidewire used for introducing a catheter into a cardiovascular system.

[0002]

2. Description of the Related Art For the purpose of angiography, a catheter of an extra-fine flexible tube is inserted into a blood vessel, or a balloon catheter is inserted into a blood vessel for treating a blockage site of a coronary artery. A medical guide wire made of a flexible wire is used in order to ensure the secure insertion of the wire, and there are known examples disclosed in Japanese Patent Publication Nos. 4-25024 and 4-292175.

That is, a known medical guide wire (hereinafter,
The guide wire is simply inserted into the blood vessel with a long and complicated curved path from the tip of the blood vessel, so that the entire body has soft flexibility and vertical load resistance (buckling resistance) against the load in the traveling direction. ) Is required, and the leading end portion of the insertion progress requires a soft tip head that smoothly leads without damaging the blood vessel wall.
Adjust the position of the tip inserted into the blood vessel by inserting the part that is inserted from the tip and out of the body while rotating it as necessary (when inserting the tip into a branch vessel, branch the tip. Adjust the direction to guide the blood vessel)
When pulling out from the inside of a blood vessel, it may be pulled out while rotating in order to alleviate pulling resistance.Therefore, there is a degree of torsional rigidity that is appropriate for that rotation, and steering that adjusts the tip of the inside of the blood vessel from outside the body. Mechanical properties are essential.

Therefore, a guide wire satisfying the above-mentioned required characteristics is a very long fine wire (for example,
Attach the tip of a rounded soft body to the tip of the core material of a stainless wire having a diameter of 0.35 and a length of about 1300), and reduce the length of the core material following the tip head to a slightly smaller diameter. It has a basic structure in which a coil spring is fitted and attached.
The coil spring is a separate spring consisting of "a coil spring made of a radiopaque material such as a platinum-nickel alloy wire in the first half and a coil spring made of a radiolucent material such as a stainless wire in the second half". A coil spring is used, and the tip portion of the coil spring fitting attachment is plastically deformed into a "dogleg shape" with a fingertip if necessary to facilitate intravascular insertion, and sequentially inserted from the tip, The required treatment is performed while confirming the tip position and direction inside the blood vessel by radiation from outside the body.

[0005]

In the conventional guide wire described above, due to the plastic deformation of the above-mentioned "dogleg shape", an appropriate bending stress remains in the wire material of the coil spring, and the coil spring is fitted and mounted. The pulled tip end receives a strong pulling resistance when it is pulled out from the blood vessel. That is, for example, in a guide wire inserted into a blood vessel narrowing portion, the blood vessel in a narrowed state and the distal end portion of the guide wire are strongly engaged with each other, so that the pull-out resistance is considerably large and a coil spring is attached to the blood vessel narrowing portion. When the middle of the coil meshes with each other, the guide wire is rotated in the direction in which the coil diameter of the coil spring closer to the tip is reduced from the engagement point (in the direction opposite to the winding direction from the lower end to the upper end of the coil spring). Since the wire main body is rotated to pass the engagement point, the pulling load and the twisting load due to the rotation are carried by the reduced diameter portion of the wire main body and the coil spring.

Therefore, the coil spring and the core material, which are made of extra fine wires, rarely break due to the above-mentioned bending stress or bearing load, for example, due to micro defects on the material, segregation of components, or the like. A coil spring consisting of a welded metal connection is separated from the connection point, and the tip part of the coil spring is separated from the wire main body, and the risk of being left inside the blood vessel is extremely small. There are difficulties.

The present invention solves the above-mentioned drawbacks of the prior art and provides a guide wire that reduces the above-mentioned risk to zero.

[0008]

The guide wire of the present invention for solving the above technical problems is described as follows: "The tip of a wire main body made of a flexible ultrafine wire is provided with a tip head, and the wire main body is continued from the tip head. In a medical guide wire in which a coil spring is fitted and attached to some part of the above, a clear lance is provided between the outer periphery of the wire main body and the inner periphery of the coil spring, and the clear lance has a tip fixed to the tip head, and
It has a structure in which a safety wire having an intermediate or rear end connected to the wire main body is provided ".

That is, the guide wire of the present invention is provided with a safety wire for connecting the middle of the tip head and the middle of the wire main body to the clearance between the coil spring and the wire main body. Even if the wire breaks or disconnects in the blood vessel, it can be pulled out without being separated from the wire main body, and when pulling out the guide wire in a normal state from the blood vessel, the twisting and pulling that the tip of the guide wire receives The structure is characterized in that a part of the load is carried by the safety wire.

The safety wire has a diameter of 0.06.
An extra-fine diameter stranded wire or single wire is used,
The tip and the back end (or the middle) are connected and connected to the tip head and the wire main body by an arbitrary means such as brazing and caulking, and the connection and fixation of the intermediate portion is performed so as not to impair the flexibility of the guide wire. In a meandering shape, to give an extension margin on the tension side when bending with the center of the wire main body as the neutral axis, and in the case of the above stranded wire, the twisting direction is the same as the winding direction of the coil spring, When inserting and withdrawing the guide wire by turning it in the winding direction of the coil spring,
A mode is adopted in which the twisting of the wire main body due to the rotation prevents the twisted wire from unraveling.

[0011]

Since the above guide wire of the present invention is equipped with the above-mentioned safety wire, even if the distal end portion of the guide wire inserted into the blood vessel is broken by any chance, the damaged portion is separated from the wire main body. The risk of being left behind is extremely low. When pulling out from a tortuous blood vessel with a guide wire in a normal state, a part of the pulling load or twisting load is shared by the safety wire, so the pulling resistance at the tip portion is further improved compared to that of the conventional structure, The risk of separation of the tip part due to load / twist load can be reduced to zero.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The medical guide wire of the present invention comprises:
It is carried out as follows.

[0013]

EXAMPLE A medical guide wire 1 according to an example of the present invention,
This will be described with reference to FIG. That is, a soft hemispherical tip 3 is provided at the tip of the wire body 2 of an ultrafine wire, and the length of the wire body 2 following the tip head 3 is slightly increased.
The cross-section has a rectangular shape and is formed into a narrowed reduced portion 4, and the reduced portion 4 has a tip having a diameter substantially equal to that of the tip head 3 and the tip 3
In the guide wire 1 in which the coil spring 5 fixed to the above is fitted and attached, a minute clear lance 6 is provided between the contracted portion 4 and the coil spring 5, and the safety wire 1 is attached to the clear lance 6.
0 is provided internally.

More specifically, as shown in FIG. 1C, the safety wire 10 is made of a well-known stranded wire in which seven ultrafine wire element wires 8 are twisted together, and is gently meandered in the longitudinal direction of the wire. It has a meandering shape. The tip 9 of the safety wire 10 is attached and fixed to the tip head 3 by an arbitrary means such as caulking or brazing, and the rear end 11 (or middle) of the safety wire 10 is brazed portion 1.
It is connected to the wire main body 2 by 2 and is provided in the clear lance 6 substantially in parallel with the contracted portion 4.

The reduced portion 4 of this embodiment is a primary reduced portion 4A having a reduced degree of reduction on the rear end side of the wire main body 2,
The lower end 11 of the safety wire 10 is composed of a continuation of the wire main body 2 and a secondary deformed portion 4B having a large degree of deformation.
Due to the above technical intention, it is connected and connected to the primary reduced shape portion 4A having a large cross-sectional shape and excellent mechanical strength.

The wire main body 2 of the guide wire 1 of this embodiment has a total length of about 1,300 and a diameter of about 0.
The safety wire 10 is a stainless steel wire of 3 grits and 0.0
A wire diameter of 0.06 is obtained by S-twisting 7 wire strands 8 having a diameter of 2 with a pitch of 0.5, and has the same twisting direction as the coil spring 5 and has a total length of about 30. The coil spring 5 has the same structure as the conventional structure in which the coil spring of the platinum-nickel alloy wire in the first half portion near the tip 3 and the coil spring of the latter half portion of the stainless wire are connected at the junction point 14.

The guide wire 1 of the embodiment shown in FIG. 1 has the above-mentioned action, and the secondary contracted portion 4 serving as a weak point of mechanical strength due to the strong pull-out resistance from the blood vessel.
Even if B is cut or the coil spring 5 is cut from the joint point 14, the safety wire 10 connects and locks the cut portion to the wire main body 2, so the risk of being left in the blood vessel becomes close to zero. . Then, in the normal state of the guide wire 1 which does not cause the division, the safety wire 10 has the reduced shape portion 4B.
・ Part of the pulling load and the twisting load that the coil spring 5 receives is shared, so the above-mentioned risk of disconnection is further reduced.
The safety is remarkably improved as compared with the conventional structure without the safety wire.

The safety wire 10 of this embodiment is
Due to the twisted wire structure consisting of the same twist direction as the coil direction of the coil spring 5, the tensile strength and the twist resistance are naturally superior to the single wire of the same diameter, and the twisting by the turning operation of the wire main body 2 (into the blood vessel At the time of insertion, the wire main body 2 is rotated in the coil winding direction of the coil spring 5 viewed from the tip, and the rotation resistance reduces the diameter of the coil spring to facilitate insertion.) The twist of the safety wire 10 is not unraveled.

Since the safety wire 10 has the above-mentioned meandering shape, when it is plastically deformed into a dogleg shape with the center line 13 of the wire main body 2 as the neutral axis at the time of insertion into the blood vessel, its bending deformation. Even when the safety wire 10 is present on the pulling side of the guide wire, the pulling margin is compensated for by extending the meandering shape, so that resistance to bending deformation is hardly generated, and the guide wire 1 when inserting into a meandering blood vessel is advanced. There is no fear of impairing the flexibility of the guide wire 1, and the required mechanical properties of the guide wire 1 can be well secured.

The guide wire 1 of the present invention is not limited to the above embodiment, the safety wire 10 may be a single wire, the meandering shape may be omitted, and a single wire main body 2 may have a plurality of wires. There are changes such as providing the safety wire 10.

[0021]

As described above, the medical guide wire of the present invention prevents the leftover portion of the distal end of the blood vessel from remaining in the blood vessel with a probability as close to zero as possible, and particularly improves the performance and safety of the guide wire. There is a remarkable effect.

[Brief description of the drawings]

FIG. 1 shows a medical guide wire according to an embodiment of the present invention,
(A) is the front view, (B) is the DD sectional view of (A),
(C) is a cross-sectional view of the safety wire

[Explanation of symbols]

 1 Medical guide wire 2 Main wire 3 Tip head 4A Primary reduced shape section 4B Secondary reduced shape section 5 Coil spring 6 Clearance 8 Wire wire 9 Safety wire tip 10 Safety wire 11 Safety wire rear end 12 Brazing part

Claims (3)

[Claims] 1. A medical guide wire in which a distal end of a wire main body made of a flexible ultrafine wire is provided with a distal end head, and a coil spring is fitted and attached to a part of the wire main body following the distal end head. A clear lance is provided between the outer circumference of the wire main body and the inner circumference of the coil spring, and a structure in which a safety wire having a tip fixed to the tip head and an intermediate or rear end connected to the wire main body is provided on the clear lance. Characteristic medical guide wire. 2. The medical guide wire of claim 1, wherein the safety wire comprises a stranded wire. 3. The medical guide wire according to claim 1, wherein the safety wire has a meandering shape.