JPH08308933A - Medical tube - Google Patents

Abstract

PURPOSE: To provide a medical tube which facilitates insertion of a blood vessel or the like into a body cavity with a proper rigidity on the side of a base part and excellent softness at the tip part and moreover, permits a larger inner diameter thereof than the outer diameter with excellent resistance to pressure. CONSTITUTION: A tip part of a metal tube 32 is formed thinner than a base part while a groove 34 made spiral continuously is formed at the tip part or a groove which is formed spirally as a whole or in rings arranged at a specified interval while being broken at points by link parts there. The outer circumference of the metal tube 32 is covered with a resin tube 33 or a resin film to form a medical tube 31.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a medical tube suitable as a catheter used for various purposes.

[0002]

2. Description of the Related Art As is well known, a catheter is guided by, for example, a guide wire, inserted into a body cavity such as a blood vessel, and its tip reaches a target site. , Various treatments with a balloon attached to the tip, treatment of arteriosclerosis by inserting a cutter, etc., ultrasonic tomography with an ultrasonic sensor, electrode at the tip Is used to make a pacemaker for the heart.

A catheter is generally made of a resin tube such as a fluororesin or a urethane resin. However, the resin tube alone is insufficient in rigidity especially on the base side and is difficult to be pushed into a body cavity such as a blood vessel. Since the torsional rigidity is insufficient and it is difficult to orient the tip in a desired direction by rotating the base side, there is a disadvantage that the insertion work cannot be performed quickly. Further, there is a problem that when the contrast agent or the liquid for balloon is injected, it swells with respect to the internal pressure, resulting in pressure loss.

On the other hand, the catheter, on the other hand, is required to have flexibility, especially at the distal end thereof, in order to prevent the catheter from being easily deformed along the change of the insertion path of the blood vessel or the like and not damaging the inner wall of the blood vessel or the like. .

In order to solve such a problem, Japanese Patent Publication No.
No. 26574 proposes a catheter shown in FIG. The catheter 11 includes a flexible inner tube portion 12
And a flexible outer tube portion 13 between the wire layer 14 and
The base end portion 14a of the wire layer 14 is densely knitted, and the tip end portion 14b is roughly knitted. The wire layer 14 increases the torsional rigidity, and the tip portion 14b of the wire layer 14 is roughened to give the tip portion flexibility. Further, the wire layer 14 enhances the pressure resistance at the time of injecting a contrast agent or the like.

[0006] In addition, the applicant of the present invention 3-1228
No. 50 discloses a medical guide wire shown in FIG. This guide wire 21 has a spiral groove 23 formed at the tip of a metal tube 22 and has a curved head 2 at the tip.
4 is formed. Also, the spiral groove 23
By narrowing the pitch as it gets closer to the tip,
It is designed to become more flexible as it approaches the tip.

[0007]

[Problems to be Solved by the Invention] Japanese Patent Publication 6-26574
The catheter 11 shown in FIG. 7 disclosed in US Pat.
Although the flexibility of the tip portion is imparted by roughening the tip portion of the wire layer 14, the wire layer 14 and the inner tube portion 1 sandwiching the wire layer 14 are provided.
Since the wall thickness of the catheter 2 and the outer tube portion 13 is large, the inner diameter of the catheter cannot be made large, and as a result, the outer diameter becomes large when trying to obtain the required inner diameter, which is not suitable for thin blood vessels. There was a problem that it could not be inserted.

On the other hand, since the guide wire 21 shown in FIG. 8 disclosed in Japanese Utility Model Laid-Open No. 3-122850 is mainly used as a guide wire, it has a head portion 24 at its tip.
Is provided, and there is a problem that it is difficult to take out the liquid medicine and various tools from the tip. Further, since the metal tube itself is used, there is a problem that the slipperiness in the body cavity such as a blood vessel is poor.

The present invention has been made in order to solve the above-mentioned problems of the prior art, and its purpose is to provide rigidity against pushing into a body cavity such as a blood vessel and torsional rigidity when the tip is directed in a desired direction. In addition, the tip has sufficient flexibility so as not to damage tissues such as blood vessels, has excellent pressure resistance when injecting a contrast agent, etc. and has a larger inner diameter than the outer diameter. Another object of the present invention is to provide a medical tube that can be processed and has good slipperiness in a body cavity such as a blood vessel.

[0010]

In order to achieve the above object, a medical tube according to the present invention is provided with a metal tube having a groove for imparting flexibility at its distal end, and a coating on the outer circumference of the metal tube. The resin tube or the resin coating is formed, and the front end portion of the metal tube is thinner than the base portion.

In the present invention, the groove is a continuous spiral groove, or is a groove having a spiral shape or an annular shape arranged at a predetermined interval as a whole, and a groove having a shape interrupted at some places by a connecting portion. Preferably there is. The groove having such a shape can be formed, for example, by etching or
It can be formed by a method such as cutting or laser machining.

The metal tube is preferably made of a shape memory alloy having superelasticity. In this case, heat treatment is performed so that the transformation point of the tip of the metal tube is higher than the transformation point of the base, for example, the transformation point of the base is 20 ° C. or lower and the transformation point of the tip is 40 ° C. or higher. May be. Thereby, the tip portion of the metal tube can be made more flexible.

Further, it is preferable that the tip of the metal tube is tapered and thin. As a method for forming the thin end portion of the metal tube, a method by etching or a method by centerless polishing can be preferably adopted. Further, the degree of thinning is preferably such that the thickness of the metal tube at the most distal end is 0.2 to 0.8 times the thickness of the base portion.

[0014]

Since the medical tubing of the present invention uses the metal tube as the core material, it has excellent rigidity on the base side, the rigidity required when pushing into the body cavity, and the tip when rotated at the hand side. The part has excellent followability, that is, rotation transmission. For this reason, the operation when inserting into the body cavity is easy, and the work can be performed quickly. Further, since a metal tube is used as the core material, it has excellent pressure resistance when a contrast agent or the like is injected.

The tip of the metal tube has, for example, a continuous spiral groove, or a spiral groove as a whole or an annular shape arranged at a predetermined interval, and a groove having a shape interrupted at some places by a connecting portion. Since the distal end portion of the metal tube is thinner than the base portion, the flexibility is excellent at the distal end portion, and it is possible to prevent the tissue in the body cavity such as a blood vessel from being damaged.

Furthermore, since the outer circumference of the metal tube is covered with the resin tube or the resin coating, the slipperiness in the body cavity such as a blood vessel is improved as compared with the case where only the metal tube is used.

Furthermore, the metal tube has sufficient rigidity even if it is thin as compared with a cylindrical mesh or the like, and is sandwiched between the inner tube and the outer tube so as not to come apart or peel off inside. Since it is not necessary to have a hollow structure, the inner diameter can be made larger than the outer diameter, and an extremely thin medical tube to be inserted into a cerebral blood vessel or the like can be manufactured.

[0018]

1 and 2 show one embodiment of the medical tube of the present invention. FIG. 1 is a side sectional view of the medical tube, and FIG. 2 is a side view showing a metal tube used in the medical tube.

As shown in FIG. 1, this medical tube 3
1 is composed of a metal tube 32 and a resin tube 33 coated on the outside thereof. As the metal tube 32, for example, stainless steel, shape memory alloy or the like is preferably adopted, but shape memory alloy having superelasticity is particularly preferable. As the resin tube 33, for example, urethane resin, fluororesin or the like is preferably adopted. The metal tube 32 and the resin tube 33 are joined by molding the metal tube 32 integrally when molding the resin tube 33, or by covering the outer circumference of the metal tube 32 with the resin tube 33 and then heat-shrinking the resin tube 33. By doing so, a method of attaching the metal tube 32 to the outer circumference thereof can be adopted.

The tip portion of the metal tube 32 is formed so that the outer circumference thereof is tapered and the wall thickness of the tube is gradually reduced. In this case, the degree of thinning is preferably such that the most advanced thickness a is 0.2 to 0.8 times the thickness b on the base side. Such processing can be performed by etching or centerless polishing.

As shown in FIG. 2, the metal tube 3
A spiral groove 34, which penetrates the inside and outside of the tube, is formed at the tip of 2 to give flexibility. The tip end 34a of the spiral groove 34 is stopped at a position that does not reach the tip end 32a of the metal tube 32, thereby preventing the tip end part from coming loose. The pitch of the spiral groove 34 is gradually narrowed toward the tip, whereby the spiral groove 3 is formed.
In the coil portion formed by No. 4, the width A on the base side is 5 to 20 mm and the width B on the tip side is 0.1 to 2 mm. The spiral groove 34 can be formed by, for example, a method by etching, a method by machining, etc. As the method by machining, cutting, laser processing, etc. are preferably adopted.

Referring again to FIG. 1, the resin tube 33
The tip portion of is protruding a predetermined length from the tip of the metal tube 32. The protrusion length C is preferably 2 to 30 mm. A ring or coil made of a radiopaque material such as gold, platinum, or an alloy thereof is arranged on the inner circumference or the outer circumference of the protruding portion 33a, and fixed to the resin tube 33 by adhesion or welding. Alternatively, it may be fixed to the tip of the metal tube 32 by a method such as brazing.

The outer diameter of the metal tube 32 is 0.4-.
2.0 mm is preferable, and the outer diameter of the resin tube 33 is 0.5 to
2.6 mm is preferred. Further, the thickness b on the base side of the metal tube 32 is preferably 0.05 to 0.2 mm.
The thickness c is preferably 0.05 to 0.3 mm. Further, the total length of the medical tube 31 is preferably 500 to 2000 mm, and the length D of the tip end portion provided with the spiral groove 34 in the metal tube 32 and having flexibility is preferably 100 to 600 mm.

The outer periphery of the resin tube 33 may be further coated with a hydrophilic resin film. As such a hydrophilic resin film, for example, the resin disclosed in JP-B-4-14991 can be used.

Further, when the metal tube 32 is made of a shape memory alloy, it may be formed so that the transformation point on the tip side, for example, the portion D in FIG. 1 is higher than the transformation point on the base side. More preferably, the transformation point on the base side is 20 ° C.
Below, the transformation point on the tip side is set to 40 ° C. or higher. As a method of making such a characteristic, the shape memory processing of the metal tube 32 is performed on the base side from 450 to 520.
C., the tip side is 400 to 480.degree. C., the method of heating for 30 minutes or more, and the memory treatment, or the whole metal tube 32 is 450.
It is possible to employ a method in which after heating at ~ 520 ° C for 30 minutes or more to perform a memory treatment, only the tip side is heated at about 400 ° C for 30 minutes to 8 hours for aging treatment.

Due to the metal tube 32, the medical tube 31 has excellent rigidity at the time of pushing and torsional rigidity at the time of rotation for orienting the tip in a desired direction, and the thickness of the tip of the metal tube 32. By gradually thinning and providing the spiral groove 34 at the tip,
The tip portion had sufficient flexibility, and therefore the insertion operation into the body cavity such as a blood vessel could be performed quickly and reliably.

When the medical tube 31 is inserted into the body cavity, it is preferable to insert the guide wire to a desired position in advance and insert the guide wire along the guide wire, but the guide wire is used. It is also possible to directly insert itself into a body cavity and guide it to a desired position without using it.

FIG. 3 shows another example of the metal tube used for the medical tube of the present invention. The metal tube 42 is provided with a spiral groove 44 at its tip, the tip 44a thereof stops at a position not reaching the tip of the metal tube 42, and the tip is gradually thinned. Similar to the example, but the pitch of the spiral groove 44 is constant, and instead, the spiral groove 44 is formed so that the groove width becomes thicker toward the tip, and as a result, the spiral groove 44 is formed. In the coil portion, the width G on the base side is 5 to 20 mm, and the width H on the tip side is 0.1 to 2
It is designed to be mm.

FIG. 4 shows another embodiment of the medical tube of the present invention. The medical tube 51 has a metal tube 52 similar to that in the above-mentioned embodiment. At the tip of the metal tube 52, a groove 53 having a spiral shape as a whole is formed.
Are formed. The spiral groove 53 is interrupted at some places by a connecting portion 54, and the coil portions formed between the grooves 53 are axially connected by the connecting portion 54. In this case, one width W of the connecting portion 54 is preferably 1/15 to 1/5 of the circumferential length of the metal tube 32, and the connecting portion 54 has a circumference of the spiral groove 53.
It is preferably provided at 0.5 to 2 places.

The spiral groove 53 is formed in the metal tube 5
The pitch is narrowed toward the tip of No.2. Further, the tip of the metal tube 52 has a spiral groove 5
From the middle of the portion where 3 is provided, as in the above embodiment,
The outer periphery of the tube is tapered so that the wall thickness of the tube is gradually reduced.

Further, a resin coating 55 of urethane resin, fluororesin or the like is formed on the outer periphery of the metal tube 52,
This improves the slipperiness within the body cavity. The resin coating 55 can be formed by, for example, spray coating, dipping or the like. The thickness of the resin coating 55 is preferably 2 to 10 μm. The metal tube 52
By providing the connecting portion 54 as described above in the spiral groove 53, the coil-shaped portion formed by the spiral groove 53 does not fully extend.

FIG. 5 shows still another embodiment of the medical tube according to the present invention. This medical tube 6
No. 1 has a metal tube 62 similar to that of the above-mentioned embodiment, and the metal tube 62 has an annular groove 63 at its tip.
However, a plurality of them are formed side by side so that the interval becomes gradually narrower toward the tip in the axial direction. The annular groove 63 is interrupted at some places by the connecting portion 64, whereby the annular portions formed between the grooves 63 are axially connected. In addition, the tip of the metal tube 62 has a tapered outer periphery as in the above embodiment,
The tube is formed so that the wall thickness is gradually reduced. Further, the outer periphery of the metal tube 62 is covered with a resin tube 65 except for the tip portion.

FIG. 6 shows still another embodiment of the medical tube according to the present invention. This medical tube 7
1 is a metal tube 72 similar to the embodiment shown in FIG.
And a resin tube 73 whose outer periphery is covered. The outer periphery of the tip of the metal tube 72 is tapered and thin, and the thickness of the tip is gradually thinner than that of the base side. Also, the metal tube 7
A groove 74 having a spiral shape as a whole is formed at the tip end of the groove 2. The groove 74 is interrupted in some places by a connecting portion 75, and the coil portion formed between the grooves 74 has the connecting portion 75. Are connected in the axial direction. Furthermore,
The spiral groove 74 has a constant pitch, but is formed so as to widen toward the tip of the metal tube 72, so that the width of the coil portion formed between the grooves 74 becomes smaller than that of the metal. It is formed so as to become narrower toward the tip of the tube 72. Therefore, the flexibility of the metal tube 72 increases toward the tip.

The medical tubing of each of the above embodiments is
Although it is linear from the base end to the tip, the tip may be bent and formed in an angle shape, for example, when the base side is rotated at the bifurcation part such as a blood vessel,
The tip can be easily oriented in a desired direction.

[0035]

As described above, according to the medical tube of the present invention, a metal tube having a groove at the tip and a thin tip, and a resin tube or resin coating covering the outer circumference thereof. Therefore, appropriate rigidity is obtained on the base side and sufficient flexibility is provided on the tip side. The resin tube or the resin coating also improves the sliding property in the body cavity such as a blood vessel. Therefore, it is possible to safely and easily perform the insertion work into a body cavity such as a blood vessel. Further, by changing the pitch or groove width of the spiral groove of the metal tube and further changing the degree of thinning of the tip of the metal tube, the flexibility at the tip can be finely and accurately adjusted. Furthermore, by using a metal tube, sufficient rigidity and pressure resistance can be obtained even with a relatively thin thickness,
Since it can take a larger inner diameter than conventional catheters,
It is possible to manufacture an extremely thin medical tube to be inserted into a cerebral blood vessel or the like. Therefore, the medical tube according to the present invention includes a catheter for administration of a contrast agent, a balloon catheter for performing various treatments by attaching a balloon to the tip, an atherectomy for treatment of arteriosclerosis, and an ultra tip. It can be used for medical tubes for various purposes such as a catheter for attaching an ultrasonic sensor to take an ultrasonic tomographic image, an electrode catheter for providing an electrode at the tip to make a pacemaker of the heart, and the like.

[Brief description of drawings]

FIG. 1 is a side sectional view showing an embodiment of a medical tube of the present invention.

FIG. 2 is a side view showing a metal tube used for the medical tube.

FIG. 3 is a side view showing another example of the metal tube used for the medical tube of the present invention.

FIG. 4 is a partial cross-sectional side view showing another embodiment of the medical tube of the present invention.

FIG. 5 is a partial sectional side view showing still another embodiment of the medical tube of the present invention.

FIG. 6 is a partial cross-sectional side view showing still another embodiment of the medical tube of the present invention.

FIG. 7 is a partially cutaway side view showing an example of a conventional catheter.

FIG. 8 is a partial side view showing an example of a conventional guide wire.

[Explanation of symbols]

 31, 51, 61, 71 Medical tube 32, 42, 52, 62, 72 Metal tube 33, 65, 73 Resin tube 55 Resin coating 34, 44, 53, 74 Spiral groove 63 Annular groove 54, 64, 75 Connection

Claims (5)

[Claims] 1. A metal tube having a groove formed for imparting flexibility to a tip portion, and a resin tube or a resin coating coated on the outer periphery of the metal tube, wherein the tip portion of the metal tube is a base portion. A medical tube characterized by being thinner than. 2. The medical tube according to claim 1, wherein the groove is a continuous spiral groove. 3. The medical tube according to claim 1, wherein the groove has a spiral shape or an annular shape arranged at predetermined intervals as a whole, and has a shape interrupted at some places by a connecting portion. 4. The medical tube according to claim 1, wherein the metal tube is made of a shape memory alloy. 5. The medical tube according to claim 1, wherein the metal tube has a tapered thin end portion.