JPH06246004A - Catheter - Google Patents

Abstract

PURPOSE:To provide a catheter capable of recovering a repairative material even if the reparative material gets inconvenient on the way of being pushed out and further separating simply the repairative material when a desired spot is filled properly with the repairative material. CONSTITUTION:A catheter is provided with a hollow catheter body 11, a guide cable 12 for pushing a repairative material 20 made of a shape memory alloy inserted from one end of the catheter body and stretched linearly out of the other end and a heating means 14 for heating the repairative material at the other end of the catheter body to recover the shape of the repairative material. A connection part 13 formed of a shape memory alloy is provided on the tip of the guide cable and heated by the heating means to recover the shape and separate the repairative material connected to the connection part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a catheter, and in particular, a repair material made of a shape-memory alloy stretched linearly inserted from one end of a hollow catheter body is pushed to the other end by a guide cable, The present invention relates to a catheter which recovers its shape by heating a repair material at the other end with a heating means.

[0002]

2. Description of the Related Art A vascular aneurysm, especially an aneurysm that occurs deep inside the human body such as the brain, is a very dangerous disease. It is common to occlude it by clipping the root, which greatly depends on the skill of the operator.

As an alternative to such an operation, a vascular repair material made of a shape memory alloy (hereinafter simply referred to as "repair material") is brought to the aneurysm generation site by a catheter having a high flexibility, Alternatively, at the entrance of the aneurysm, an attempt to thrombosis of the aneurysm by indwelling after recovering to a desired shape is made in Japanese Patent Application Laid-Open No. 2-71762, Proc. Academic Conference, Heisei 4
Issued on March 5, 2012).

FIG. 8 shows an example of the catheter proposed in the above publication. In the figure, the middle part is omitted, the tip part on the side of inserting into the blood vessel is on the left side, and the operator's operating part is on the right side. The catheter 100 is composed of a hollow main body 110 made of an antithrombotic material, and an extruding wire 120 and the like that are electrically connected therein.

In using the catheter 100,
As shown in FIG. 9, the distal end portion is inserted until it reaches the vicinity of the entrance of the aneurysm L12 formed in the artery L11, and the hollow main body 110 is memorized in a predetermined shape from the operation portion side in advance, A repair material 130 made of a shape-memory alloy stretched linearly is inserted, and then the extruded wire 1 is inserted.
20 is inserted, and the repair material 130 is pushed out from the tip of the hollow main body 110 by the tip thereof. Further, a water pipe 140 is arranged in parallel in the hollow main body 110, and the repair material 130 extruded by the hot water supplied through the water pipe 140 is heated to recover its shape and is left indwelling.

[0006]

In the above-mentioned conventional catheter, since the repair material is only pushed out by the push-out wire, once the push-out operation is started, the repair material cannot be recovered even if the push-out state becomes inconvenient during the operation. There is a problem.

Therefore, when a repair material is connected to the tip of the extruded wire and a mechanical connecting means that can separate the extruded wire after completion of the extruding is provided, a problem occurs in the extruded state,
By pulling out the push-out wire, it is possible to also pull out the repair material connected to the tip of the push-out wire.However, in general, the mechanical connecting means has a complicated structure and becomes large in size. The hollow main body that needs to be inserted from one end becomes thick and cannot be put to practical use.

Therefore, in view of the above problems, the present invention can recover the repairing material even if the extruded state of the repairing material becomes inconvenient on the way, and when the repairing material can be properly filled in a desired place, the separation can be easily performed. It is an object of the present invention to provide a catheter that can be used in the above.

[0009]

In order to achieve the above-mentioned object, a catheter made according to the present invention comprises a hollow catheter body, and a repair made of a linear shape-stretched shape memory alloy inserted from one end of the catheter body. In a catheter comprising a guide cable for pushing a material to the other end and a heating means for heating the repair material at the other end of the catheter body to restore its shape, a connecting portion made of a shape memory alloy is provided at the tip of the guide cable. It is characterized in that the repairing material connected to the connecting portion is separated by heating the connecting portion by the heating means to recover the shape.

[0010]

With the above construction, a connecting portion made of a shape memory alloy is formed at the tip of the guide cable, and the repair material connected to this connecting portion is heated by the heating means to recover the shape and repair. Since the connection of the materials is released, it is possible to pull out the repaired material pushed out at an arbitrary point in the middle unless the connection between the guide cable and the repairing material is released.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of a catheter according to the present invention applied to insert a repair material 20 into the aneurysm L2 by inserting the distal end portion thereof until reaching the entrance of the aneurysm L2 formed on the artery L1. In FIG. 1, the catheter 10 includes a hollow catheter body 11, a guide cable 12 that pushes out a repair material 20 inserted from one end (not shown) of the catheter body 11 from the other end side, and a repair material at the other end portion of the catheter body 11. The heater 14 is provided as a heating means for heating the 20 to 40 to 42 ° C. to recover the shape.

The heating temperature of the heater 14 is selected such that it does not adversely affect the living body and the repair material 20 does not recover its shape due to the body temperature before reaching the aneurysm generation site. A connecting portion 13 made of a shape memory alloy is provided at the tip of the guide cable 12, and the connecting portion 13 is heated to, for example, 40 to 50 ° C. by the heater 14 to recover its shape, and the repair material 20 connected thereto is attached. I try to separate them.

FIG. 2 shows a concrete example of the connecting portion 13 provided at the tip of the guide cable 12. The connecting portion 13 is made of the same shape memory alloy as that of the repair material 20 and is linearly memorized. Bend the existing connecting part 13 into a hook shape,
As shown in (a), the hook-shaped connecting portion 13 is attached to the repair material 20.
It is connected to the repair material 20 by hanging on the loop 21 formed at one end of the repair material 20. Then, the hook-shaped connecting portion 13 is heated to recover the hook-shaped connecting portion 13 into a linear shape as shown in (b), whereby the connection with the repair material 20 is released.

The repair material 20 is preferably the one shown in FIG.
The one shown in is used. In the figure, a repair material 20 is a core wire 2 made of a shape memory alloy having a diameter of about 0.1 mm.
2 and a coil material 23 wound around the core wire 22 form a spiral structure. The coil material 23 is made of a fine metal wire (diameter 100, 70, 50 μm) such as platinum, stainless steel, silver, or gold, which has excellent biocompatibility. Both ends of the coil material 23 are welded to both ends of the core wire 22, respectively, and smooth end face processing portions 24 are formed so as not to damage or break through the living body when the living body is filled.

With this structure, as the shape memory alloy of the core wire 22, it is possible to use a thin one having a small diameter with low rigidity which does not cause a breakthrough of a living body, and a small density and a light weight, which is suitable for implantation in the body. Becomes The alloy used is N, which forms a dense titanium oxide film on the surface of the alloy.
An i-Ti based alloy is suitable, which has a high corrosion resistance and is therefore stable in vivo and excellent in biocompatibility. Further, the coil material 23 forms a coil material for expanding the surface area of the repair material 20 and promoting the thrombus formation.

The repair material 20 having a spiral structure shown in FIG. 3 is exaggerated in order to clearly show the structure, but the actual size thereof is, as shown in the figure, a linear length of 20 to 30 mm. It is set to an appropriate length. On the other hand, regarding the diameter, the diameter including the coil material 22 around the core wire 21 is 0.457 mm or less, and is set so that it can be easily loaded into the bore of the catheter body 11.

The repair material 20 shown in FIG. 3 is stored in the three-dimensional shape once before it is used, and then the catheter body 11 is processed.
It is stretched in a straight line prior to insertion into a sheet, the details of which will be described with reference to FIG. Prior to the heat treatment, the linear repair material 20 is heat-treated as shown in (a), and in this state, it is transformed into a three-dimensional shape to be memorized as shown in (b), and then cooled to memorize the shape. .

Subsequently, it is stretched linearly as shown in (c), and in this state, it is inserted into the main body of the catheter inserted into the blood vessel from one end, and is extruded from the other end to the aneurysm generation site by a guide cable, and heated there. By doing so, the memorized shape is restored as shown in (d).

FIG. 5 shows another embodiment of the connecting portion, in which the connecting portion 13 is formed by a shape memory alloy coil in which the shape is remembered so as to recover the shape to a diameter larger than the diameter of the end surface processing portion 24 of the repair material 20. , (A), the coil of the connecting portion is deformed to connect the end surface processing portion 23 of the repair material 20. The connection of the repair material 20 can be released by expanding the diameter of the coil-shaped connecting portion 13 in the outer diameter direction shown by "↑" and "↓" as shown in the figure by the shape recovery as shown in (b). .

FIG. 6 shows still another embodiment of the connecting portion, which is formed by a shape memory alloy joint memorized so as to recover the shape to a diameter larger than the diameter of the end surface processing portion 23 of the repair material 20, As shown in (a), the joint of the connecting portion is deformed to connect the end surface processing portion 23 of the repair material 20. To release the connection of the repair material 20,
As shown in (b), the diameter of the joint-shaped connecting portion 13 is expanded by the shape recovery so as to expand in the outer diameter direction indicated by "↑" and "↓" as shown in the figure.

The repair material 20 of the illustrated embodiment is shown in FIG.
As shown in (a), it is a type to be placed in an aneurysm, and when the shape is restored, thin wires are overlapped to form a spherical shape, but the present invention is to be placed in an artery wall as shown in (b). The coil-shaped type, or the type in which it is placed in the arterial wall like the (b) type as shown in (c), and can also be applied to the braided type.

Further, in the above-mentioned embodiment, the shape memory alloy forming the connecting portion is formed of the same shape memory alloy forming the repair material, and the shape recovery temperature is the same.
By setting the temperature of the repair material to a slightly lower temperature of 40 to 42 ° C and the recovery temperature of the connection portion to a slightly higher temperature of 50 ° C, it is possible to prevent the connection portion from being erroneously shape-recovered when the shape of the repair material is recovered. It will be possible.

Further, in the illustrated embodiment, the heater provided at the other end of the catheter body is used as the heating means for the repair material and the connecting portion, but the hot water adopted in the prior art is used. It is also possible to use heating means.

[0024]

As described above, according to the present invention, the repair material is connected by the connecting portion made of the shape memory alloy, and the connecting portion is heated to recover its shape to release the connection. Simple and compact, repairing material can be collected even if there is a problem in the extruded state without thickening the hollow catheter body, connecting and disconnecting the repairing material is easy, and operation reliability Can be secured.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of a catheter according to the present invention.

FIG. 2 is a diagram showing an example of a connecting portion in FIG.

FIG. 3 is a diagram showing an example of a repair material.

FIG. 4 is a diagram showing a procedure for shape memory and shape recovery of a repair material.

5 is a diagram showing another example of the connecting portion in FIG.

FIG. 6 is a view showing still another example of the connecting portion in FIG.

FIG. 7 is a diagram showing examples of various repair materials.

FIG. 8 is a cross-sectional view of a conventional catheter.

FIG. 9 is a view showing a usage state of the catheter of FIG.

[Explanation of symbols]

 10 catheter 11 catheter main body 12 guide cable 13 connecting portion 14 heater (heating means) 20 repair material

 ─────────────────────────────────────────────────── --- Continuation of the front page (72) Inventor Masao Miyagi 1-204 Higashi Taisei-cho, Omiya City, Saitama Prefecture (72) Inventor Koho Takakura 1-27-20 Fukasawa, Setagaya-ku, Tokyo (72) Inventor Shigeru Nemoto Chiba Prefecture 3-28-8 Mihama, Urawa City

Claims (1)

[Claims] 1. A hollow catheter body, a guide cable which is inserted from one end of the catheter body and which pushes out a repair material made of a linearly stretched shape memory alloy to the other end, and at the other end of the catheter body, In a catheter provided with a heating means for heating a repair material to recover its shape, a connecting portion made of a shape memory alloy is provided at the tip of the guide cable, the connecting portion is heated by the heating means to recover the shape, and the connecting portion. A catheter characterized in that the repair material connected to the portion is separated.