JPS6063065A - Guide wire for catheter - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention ■Background of the Invention Technical Field The present invention relates to a catheter kite wire that is capable of guiding a catheter, and is used to guide a therapeutic or testing catheter to a predetermined site in a blood vessel, digestive tract, trachea or other body cavity. The present invention relates to a catheter guide wire that can be introduced and placed.

BACKGROUND ART Conventionally, a coiled kite wire made of stainless steel wire or piano wire, or a heptad filament-shaped guide wire made of plastic has been used as a guide wire for a catheter. - ■ 1. Conventional guide wires all include general metal materials such as stainless steel wire and piano wire, whose cross-sectional area gradually decreases from the main body toward the tip, in part or the entire length of the guide wire. As a result, a relatively rigid main body portion and a relatively flexible tip portion are formed.

1. The guide wire is inserted percutaneously into a blood vessel at the introduction side, etc., as is typical when an angiography catheter is placed in a predetermined blood vessel site, and the end of the main body of the guide wire is located outside the body. It is often used to insert the tip of the catheter into the blood vessel using the guide wire as the axis. Therefore, the above-mentioned kite wire can be inserted smoothly into a blood vessel against the resistance generated between the outer surface of the guide wire and the tissue, and can also be inserted against the resistance generated between the outer surface of the guide wire and the inner surface of the catheter. A certain degree of rigidity is provided to the main body so that the catheter can be guided.

However, as mentioned above, the main body of the conventional guidewire is made of a general metal material, and as it undergoes plastic deformation above a certain displacement, the guidewire may buckle depending on the manual operation. According to
The buckled portion becomes a deformed portion that cannot be restored, and this deformed portion creates a large resistance to the advancement of the catheter, making it difficult to smoothly introduce the catheter. In addition, when guiding a catheter with the distal end curved in advance to facilitate insertion into a predetermined vascular site, the catheter is inserted into the guide wire and straightened. The insertion resistance of the catheter against the guide wire increases, and the possibility of trouble occurring due to the buckling increases.

In addition, after the catheter is inserted into the blood vessel together with the guide wire, the distal end of the guide wire, which protrudes by a predetermined length from the distal opening of the catheter, is further inserted into the blood vessel in order to reach a predetermined vascular site. We need to get ahead and push forward. Therefore, the tip of the conventional kite wire is required to have good shape adaptability even in tortuous blood vessels without damaging the blood vessel wall, and flexibility so that it can be inserted into complicated blood vessel branches.

However, as mentioned above, conventional guidewires
The distal end is made of a general metal material or plastic, and if the displacement exceeds a certain level, plastic deformation occurs, impairing the flexible blood vessel running to the specified blood vessel site.
In addition, even when the tip of the guidewire reaches the specified blood vessel site, the tip has reduced rebound resilience due to plastic deformation, so when the tip of the catheter is advanced, it resists the bending stress of the catheter. There is no resistance between the guidewire tip and the blood vessel wall necessary to keep the guidewire tip in place, and as a result, the guidewire tip is pulled out of the predetermined vascular site. This often results in failure to place the device in the appropriate location, or a large amount of procedure time. In addition, in order to prevent damage to the blood vessel wall and to prevent the blood vessel from getting caught during self-travelling, there is a guidewire whose tip has been deformed into a single-letter shape. Because it is deformed into a straight line, it does not restore to a perfect straight shape within the blood vessel,
Many of them have the disadvantage that they do not fully demonstrate their initial functions.

II. OBJECTS OF THE INVENTION It is an object of the present invention to provide a catheter guide wire that allows a catheter to be reliably and easily introduced into a predetermined site.

■Structure of the Invention In order to achieve the above object, the present invention provides a catheter guide wire having a relatively rigid main body and a relatively flexible distal end. The part is made of a superelastic metal body.

Further, in the present invention, the main body portion is formed of a superelastic metal body.

Further, in the present invention, the tip portion is formed of a superelastic metal body.

Further, in the present invention, both the main body portion and the tip portion are formed of a superelastic metal body.

The present invention also provides a method in which the cross-sectional area of at least a portion of the tip is smaller than the cross-sectional area of the main body, and the cross-sectional area between the main body and the tip is continuous from the main body to the tip. It is designed to be reduced in size.

IV Detailed Description of the Invention FIG. 1 is a plan view showing a catheter guide wire IO according to an embodiment of the present invention, and FIGS. 2 to 4 are views taken along lines II-II to IV-IV in FIG. FIG.

The guide wire IO has a relatively rigid body portion 11 and a relatively flexible tip portion 12, and has a tapered portion 13 between the two.

The guide wire 10 has a total content of 48 to 58 atom%.
T1Ni alloy of Ni, 38.5-41.5 wt% Znc
y) Cu-Zn alloy, l~lo weight%X (7) Cu
-Zn-X alloy (X=Be, St, Sn, AI,
It is formed of a superelastic (pseudoelastic) metal body such as a Ni-Al alloy containing 38 to 38 atomic percent Al (Ga), 38 to 38 at.

The main body 11 of the guide wire 10 has an outer diameter of 0.8θmm.
, the length is 130cm, and the yield stress is 10-80K.
g/m tn' (manufactured by Toyo Seiki Co., Ltd., Strograph M
Distance between mold and chuck: 80 mm, speed: 5 mm
7min at a tensile temperature of 22°C). Restoration stress (yield stress upon unloading (B in Figure 7) is 60K
g/mrn' (22°C) or less. In addition,
The outer diameter of the main body portion 11 is preferably set in the range of 0.1 to 2 mm, more preferably 0.45 to 1.15' mm. Further, the length of the main body portion 11 is preferably set in a range of 10 to 300 cm.

The distal end 12 of the guide wire 10 has an outer diameter of 0.2 mm,
The length is 20 cm, the yield stress is 10 to 80 Kg/mm',
The restoring stress is set to 0 to 80 Kg/mtn' or less. The outer diameter of the tip portion 12 is set in the range of 0.05 to 1.5 mm, more preferably 0.1 to 0.5 mm (however, it does not exceed the outer diameter of the main body 11). It is better. Further, the length of the tip portion 12 is preferably set in a range of 1 to 50 cm, more preferably 2 to 30 cm. Yield stress at the tip of the example: 18-24 Kg/mm',
The restoring stress was in the range of 12 to 18 K g/mrn' (7).

The most distal end 14 of the distal end 12 of the guide wire 10 is rounded to prevent it from penetrating the blood vessel wall. Further, the tapered portion 13 has its cross-sectional area continuously reduced from the main body portion 11 toward the distal end portion 12, and the main body portion 1. The change in rigidity at the connecting portion between the guide wire t and the distal end portion 12 is made gradual to prevent bending of the guide wire 10 at the connecting portion.

Note that the distal end of the distal end 12 of the guide wire 10 is not necessarily R-shaped, but has a spherical shape as shown by 15 in FIG. condition, 5th
By forming a coil shape as shown at 17 in Figure (C) or a ring shape as shown at 18 in Figure 5 (D), penetration into the blood vessel wall can be prevented. Good too.

In addition, the guide wire lo is shown in Fig. 6 (,A), (B).
As shown in FIG. 2, by curve-forming the distal end portions 12A and 12B into a predetermined shape similar to a blood vessel running or branching, insertion into a predetermined blood vessel site can be performed reliably and easily.

In addition, the main body part 11 and the distal end part 1 of the guide wire lo
The connecting portion with the main body 11 and the distal end 12 need not necessarily be tapered, but may have a cross-sectional shape that does not cause a significant change in cross-sectional area between the main body 11 and the tip 12. The tip portion 12 may have an intermediate outer diameter.

Figure 7 shows an outer diameter of 0. Elmm, the bending load (W) - displacement amount CD) characteristics of the T i Ni alloy forming a cantilever beam with a length of 20 mm are shown by the solid line, and the outer diameter is 0.45 mm.
, is a diagram showing, by broken lines, the bending load-displacement characteristics of a stainless steel wire forming a cantilever beam with a length of 20 mm. FIG. The bending load-displacement characteristics of the T i Ni alloy are shown by solid lines, and the outer diameter is 0°1 mm and the length is 20 mm.
FIG. 3 is a diagram showing, by broken lines, the bending load-displacement characteristics of the stainless steel wire forming the cantilever beam. Furthermore, in FIGS. 7 and 8, E is the amount of plastic residual strain of the stainless steel wire. That is, according to FIGS. 7 and 8, the superelastic metal body has (1) a large recoverable elastic strain;
It reaches several percent to several percent of lO, and has the characteristic that (2) the magnitude of the load does not change even if the strain increases. Therefore, since the guide wire 10 has its main body 11 made of a superelastic metal body having bending load-displacement characteristics that are approximately the same as the solid line in FIG.
11 has elastic strain characteristics with relatively high buckling strength. In addition, since the kite wire 10 described in item 1 is formed of a superelastic metal body having bending load-displacement characteristics that are approximately the same as the solid line in FIG.
The distal end portion 12 has an elastic strain characteristic that allows it to undergo a relatively large displacement under a constant stress and be restored.

■Specific effects of the invention Next, the operation of the above embodiment will be explained.

The guide wire 10 may have a straight shape as shown in FIG. Some catheters have a life function that allows the catheter 20 to advance smoothly in the blood vessel 21 by keeping the catheter 20 straight under insertion of the main body 11 having high rigidity. Also, Kitewire l.

The distal end 12 of the catheter 2o is placed in front of the distal end of the catheter 2o, and the distal end of the catheter 2o is positioned at a predetermined blood vessel site 22.
It is possible to lead to

Here, the guide wire 10 has an elastic strain characteristic in which the main body portion 11 has a relatively large yield stress. Therefore, even if a relatively large bending deformation occurs in the main body portion 11 when inserting the guide wire 10 into a catheter or blood vessel,
The main body part 1 does not reach the plastic deformation region and cause buckling.
It becomes possible to change the buckling limit of 1. That is, even if the main body portion 11 is significantly deformed due to manual manipulation applied to the guide wire 10, the deformed portion easily returns to its straight state and does not become a resistance to the advancement of the catheter. Also, when a catheter having a curved portion at the tip is inserted into the crown while being straightened, the main body portion 11
This allows the catheter to be advanced smoothly without creating any resistance between the catheter and the catheter.

Further, the above-mentioned kite wire IO has an elastic strain characteristic that allows the distal end portion 12 to undergo a relatively large displacement under a constant stress and to be able to recover. Therefore, when the distal end portion 12 moves through a bend in the blood vessel, it easily undergoes large bending deformation with a relatively small load, and without damaging the blood vessel wall, bends and deforms in response to changes in the bend in the blood vessel. Repeat the restoration,
It has good shape adaptability to tortuous m-tubes, can be curved relatively easily to blood vessel branches, and can be smoothly advanced to a predetermined blood vessel site. In addition, when inserting the catheter into a predetermined blood vessel site, the distal end 12 is provided with rebound elasticity sufficient to create the resistance against the blood vessel wall necessary for the catheter to remain in a predetermined position against bending stress. The catheter can be appropriately indwelled without the portion 12 being pulled out from the predetermined blood vessel site. Furthermore, even if the distal end portion 12, which has been curved in advance, is deformed into a straight line when passing through the introducer needle, it will be restored to its completely curved shape upon subsequent insertion into the blood vessel, and the initial function will be fully satisfied. possible.

Furthermore, unlike conventional coiled kite wires, the guide wire 10 has no irregularities on its surface, so it is better against blood coagulation, and has increased tensile strength compared to plastic kite wires, making it safer. It is.

Furthermore, unlike conventional coiled guidewires, the guidewire 10 has good torque transmittance in both torsional directions, and the distal end 12 can be reliably directed toward a predetermined vascular site by the torque applied to the main body 11. It is easily directional and has good operability for insertion into complex blood vessel sites.

In the above embodiments, the guide wire 10 has been described in which both the main body portion 11 and the distal end portion 12 are made of a superelastic metal body. However, in the present invention, only the main body of the guidewire may be formed of a superelastic metal body, and the main body may be provided with an elastic strain characteristic having a relatively large yield stress, and only the distal end of the guidewire may be formed of a superelastic metal body. The tip may be formed of a superelastic metal body, and the distal end portion may have an elastic strain characteristic that allows a relatively large displacement under a constant stress and allows recovery.

∎Effects of the Invention As described in ``2'', the present invention provides a catheter guide wire having a relatively rigid main body and a relatively flexible distal end. is made of a superelastic metal body. Therefore, it becomes possible to introduce the catheter into a predetermined site reliably and easily.

Further, according to the present invention, by forming the main body portion from a superelastic metal body, the main body portion can be provided with elastic strain characteristics having a relatively large yield stress.

In addition, the present invention has the tip portion made of a superelastic metal body, so that it can be displaced relatively largely under constant stress.
In addition, the distal end portion has elastic strain characteristics that can be restored.

Furthermore, by forming both the main body and the distal end of a superelastic metal body, the main body has an elastic strain characteristic with a relatively large yield stress, and the yield stress is relatively large under a constant stress. It becomes possible to provide the distal end with elastic strain characteristics that can be displaced and restored.

In addition, the present invention has the cross-sectional area of the tip portion smaller than the cross-sectional area of the main body portion, and the cross-sectional area between the main body portion and at least a portion of the tip portion is continuous from the main body portion to the tip portion. By reducing the size, the change in rigidity at the connecting portion between the main body portion and the distal end portion can be made gradual, and it is possible to prevent the occurrence of bending at the connecting portion.

[Brief explanation of drawings]

FIG. 1 is a plan view showing a catheter guide wire according to an embodiment of the present invention, FIG. 2 is a sectional view taken along line II--II in FIG. 1, and FIG. 3 is a cross-sectional view taken along line II-II in FIG. A cross-sectional view along
4 is a sectional view taken along the line IV-IV in FIG. 1, FIGS. Figures (A) and (B)
) is a plan view showing the shape of the tip of a kite wire according to a modified example of the present invention. FIGS. 7 and 8 are diagrams showing the bending load-displacement characteristics of a superelastic metal body and a general elastic metal body, and FIG. 9 is a schematic diagram showing how the guide wire according to the present invention is used. 10... Guide wire, 11... Main body, 12.1
2A, 12B... Tip portion, 13... Taper portion. Patent applicant Fuji Terumo Co., Ltd. Agent Patent attorney Osamu Shiokawa

Claims (1)

[Claims] (+) A guide wire for a catheter having a relatively rigid main body and a relatively flexible distal end, in which at least a portion of the main body and the distal end are made of a superelastic metal. A guidewire for a catheter, characterized in that it is formed by: (2) The guide wire for a catheter according to claim 1, wherein the main body portion is formed of a superelastic metal body. (3) The guide wire for a catheter according to claim 1, wherein the distal end portion is formed of a superelastic metal body. (4) The guide wire for a catheter according to claim 1, wherein both the main body portion and the distal end portion are formed of a superelastic metal body. (5) The cross-sectional area of at least a portion of the tip is made smaller than the cross-sectional area of the main body, and the cross-sectional area between the main body and the tip is continuously reduced from the main body to the tip. 4. A kitewire for a catheter according to any one of claims 1 to 4.