JPH06319803A - Catheter - Google Patents

Abstract

PURPOSE:To provide the catheter which is soft at its front end and is hard at its base end by arranging a tube for adjusting hardness formed with breaks which are higher in density nearer the front end within a catheter tube. CONSTITUTION:The tube 15b for adjusting hardness is arranged on the inside surface 15a of the outer tube 15. This tube 15b for adjusting hardness is adhered to the outer tube 15. The breaks 15e having the width gradually increasing toward the base end 15d (i.e., the density gradually decreasing) are spirally formed on the tube 15b for adjusting hardness and the remaining base end 15d is formed as a cylindrical body. The breaks 15e are formed by pressing a cutter to the tube 15b for adjusting hardness and gradually lowering the moving speed of this cutter toward the base end 15d from the front end 15 while rotating the tube 15b for adjusting hardness of the cylindrical body. The breaks 15e are otherwise formed by spirally winding ribbon-shaped nylon having a narrow width at the front end 15c and the width gradually increasing toward the base end 15d.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to catheters.

[0002]

2. Description of the Related Art A catheter is a tube member that is inserted from the outside to a predetermined site such as a lesion in the body for diagnosis and treatment. In terms of its function, it is important for this catheter that it can be bent and inserted along a guide wire or a blood vessel to a predetermined site in the body.

However, in the conventional catheter,
The hardness was relatively high in order to be able to push it to a predetermined part in the body. Therefore, when the tip is finally inserted into a thin site, for example, a thin blood vessel, it cannot be bent properly, and it is difficult to insert the catheter to a predetermined site. On the other hand, when the catheter is made of a flexible material, it is easy to bend at a thin portion, but it is difficult to push the catheter into the body at the proximal end.

From this point of view, a catheter has been proposed in which a gold wire having a uniform thickness is tightly wound to maintain the hardness and to be freely bendable.

[0005]

However, even in the catheter having the gold wire wound around it, although the flexibility is slightly improved, the overall hardness is still uniform.
For this reason, the tip was too hard to be successfully inserted into the thin portion as described above if it had sufficient hardness to be pushed into the body.

[0006] Therefore, an object of the present invention is to solve the above problems and to provide a catheter having a flexible distal end and a rigid proximal end.

[0007]

The catheter of the first aspect of the present invention is characterized in that a hardness adjusting tube having a cut formed therein, the density of which increases as it approaches the distal end portion, is arranged in the catheter tube.

The catheter of the second aspect of the present invention is characterized in that a hardness adjusting tube having a groove whose density increases as it approaches the distal end is arranged in the catheter tube.

[0009]

According to the catheter of the present invention, the hardness adjusting tube is arranged inside the catheter tube. The hardness adjustment tube has different densities of cuts or grooves depending on the position, and therefore the hardness thereof varies depending on the position. That is, since the density of the cuts or grooves is high at the tip portion, fine bending is free and flexible. On the other hand, at the proximal end,
The low or zero density of the cuts or grooves maintains sufficient hardness for inserting the catheter into the body. Therefore, it is possible to freely change the hardness according to the position by changing the density of the cuts or grooves as desired. For example, the hardness can be continuously changed by gradually changing the density of cuts or grooves. Therefore, it was possible to obtain a catheter having a flexible distal end and a hard proximal end with a very simple structure in which a hardness adjusting tube having a cut or groove is simply arranged.

The cuts or grooves may be provided in a direction or position where they are easily bent depending on the intended use, may be oriented in any of vertical, horizontal and diagonal directions, and are irregularly formed in various directions. It may be a thing. Further, the cut may be formed by winding a ribbon having a thin tip end and a wide base end, without making the cut by cutting. The groove refers to a part where the wall pressure is thinned without completely cutting the cross section, and the shape is a U-shaped cross section, a V-shaped cross section, or a straight cut. It may be contained, or may be one in which the meat pressure is formed gently and thinly by a crimping technique or the like.

As a material for the tube for adjusting hardness, a material having an appropriate hardness which does not cause a disadvantageous effect may be selected according to its use. For example, polypropylene, polyacetal, polyethylene, polyester, polycarbonate, polyurethane, polyamide. Etc., or a metal such as gold.

The wall pressure of the hardness adjusting tube may be determined as desired according to the wall pressure of the catheter to be applied, the hardness of the hardness adjusting tube itself, and the like, but is not particularly limited.
03-0.3 mm, especially 0.05 mm is preferable. The length of the tip portion that forms a cut or groove in the hardness adjusting tube may be determined as desired according to the application and the hardness of the hardness adjusting tube itself, and is not particularly limited, but is 5 cm for a catheter having a total length of 30 to 300 cm. that's all,
30 cm is particularly preferable for a catheter having a total length of 135 cm.

As the catheter to be applied, any conventionally known catheter which is preferably flexible at the distal end and hard at the proximal end can be applied. For example, PCT
A balloon catheter, PTA balloon catheter, I
ABP balloon catheter etc. are mentioned.

[0014]

Preferred embodiments of the present invention will be described below in order to further clarify the constitution and operation of the present invention described above. [Embodiment 1] FIG. 1 is a schematic front view showing an intravascular drug delivery balloon catheter 1 of this embodiment in which a balloon portion 3 is inflated. The intravascular drug delivery balloon catheter 1 of the present embodiment has a total length of 135 cm and is composed of a balloon portion 3 and a shaft portion 5.

As shown in a partially enlarged view of FIG. 2, the balloon portion 3 has an inner tube 7 penetrating the center portion thereof. The inner tube 7 is for inserting a guide wire that is inserted into a blood vessel and guides the balloon portion 3 to an appropriate site. The inner tube 7 may be made of any conventionally known material, and examples thereof include polyethylene, polypropylene, polyamide, polyacetal, and fluororesin.

Around the inner tube 7, as shown in the AA end view in FIG. 3, it becomes a hollow cylindrical shape [see FIG. 3 (a)] when expanded, and a wing shape when contracted [FIG.
(See (b)] is provided. In practice, the winged sleeve 9 is folded around the inner tube 7 when contracted in any suitable manner, for example artificially or by scoring the material. The tip 11 of the balloon portion 3 is adhered or adhered so that the inner tube 7 and the sleeve 9 are not separated by the pressure. Further, it has an appropriate shape and hardness so that it can be easily inserted and moved into a blood vessel, it can be inserted into the blood vessel from the outside to move in the blood vessel, and the blood vessel is not damaged. On the outer surface 7a of the inner tube 7 inside the balloon portion 3, a marker 12 for detecting that it has reached an appropriate portion (namely, a lesion portion) is annularly arranged. The marker 12 is a radiopaque material such as Au or P.
It is composed of t.

On the outer wall of the sleeve 9, a drug carrying layer 13 is provided. The drug-carrying layer 13 is a layer of a water-absorbent polymer, which absorbs the drug by impregnation, but releases little or no drug under normal pressure, and the balloon portion 3
It has the property of releasing the drug by closely adhering to the lesion due to expansion. Although polyvinyl alcohol was used in this example, examples of polymers having such properties include carboxymethyl cellulose, polyacrylic acid, sodium polyacrylate, and polyacrylamide, which can be used equivalently.

As shown in the BB end view of FIG. 4 and the partially enlarged cutaway view of FIG. 5, the shaft portion 5 is continuously pierced by the inner tube 7 penetrated by the balloon portion 3 at the center thereof. The outer tube 15 concentric with the inner tube 7 is provided on the outer side of the outer tube 15. The outer tube 15 is continuous with the sleeve 9 of the balloon portion 3, and is a path for expanding the sleeve 9 by applying pressure from the external pressure supply means, for example, liquid to the sleeve 9. The outer tube 15 and the inner tube 7 are
As shown in the C-C end view in FIG. 6, the balloon portion 3 and the shaft portion 5 are bonded with a thermoplastic resin 16 at the boundary portion, and the sleeve 9 is attached to a part of the thermoplastic resin 16.
Is provided with a hole 16a through which a liquid for expanding the liquid can pass. Therefore, the space in the outer tube 15 and the hollow in the sleeve 9 are continuous by this hole 16a. The outer tube 15 may be made of any conventionally known material, for example, polyethylene, ethylene vinyl acetate copolymer, ethylene acrylic acid copolymer, ethylene acrylic acid ester copolymer, ionomer, polyester, polyamide. , Polysulfone, polyacetal, polyurethane and the like.

A hardness adjusting tube 15b is disposed on the inner surface 15a of the outer tube 15. The hardness adjusting tube 15b is preferably adhered to the outer tube 15 with an adhesive or a pressure sensitive adhesive. As shown in the front view of FIG. 7, the hardness adjusting tube 15b has a spiral portion 15e (30 cm) with a gradually increasing width (that is, decreasing density) 15e toward the base end portion 15d. The remaining base end portion 15d (105 cm) is a tubular body. Here, the cut 15e is the tube 1 for adjusting the hardness of the cylindrical body.
While rotating 5b, put a cutter on the hardness adjusting tube 15b and change the moving speed of the cutter to the tip 1
It can be formed by gradually slowing from 5c toward the base end portion 15d. Alternatively, the break 15e
May be formed by spirally winding a ribbon-shaped nylon having a narrow width at the distal end 15c and gradually widening toward the proximal end 15d. In this example, the nylon hardness adjusting tube 15b was used, but the present invention is not limited to this, and polypropylene, polyacetal, polyethylene, polyester, polycarbonate,
Polyurethane or the like can be applied equally.

Further, accessories such as a connector 17a, an expansion port 17b or a guide wire port 17c are hermetically attached to the base end 17 of the shaft portion 5. Here, a method for applying the intravascular drug delivery balloon catheter 1 of the present embodiment will be described. FIG. 8 is a schematic diagram for explaining it.

In advance, a balloon catheter for intravascular administration 1
In the state where the sleeve 9 is expanded, the drug carrying layer 1
3 is impregnated with a proper amount of the drug A (step 1), and the sleeve 9 is contracted and the sleeve 9 is naturally wound around the inner tube 7 (step 2). At this time, since only the internal pressure is reduced, no pressure is applied to the outside, and therefore the drug A
Is not released, and since the sleeve 9 is formed with a fold, it is naturally folded as it contracts. Here, the drug carrying layer 13 releases little or no drug unless it is pressurized.

A sheath 23 is inserted into the femoral artery 21, a guide catheter 25 is inserted through the sheath 23, and an inlet 27 of a coronary artery 31 having a lesion 29 to be treated (the enlarged view is shown by a chain line). (Step 3). Next, the intravascular drug delivery balloon catheter 1 into which the guide wire 19 has been inserted is inserted through the guide catheter 25 (step 4). The balloon catheter 1 for intravascular administration is set in the target lesioned portion 29 while the guide wire 19 is advanced from the entrance 27 of the coronary artery (step 5).

In the balloon catheter 1 for intravascular administration, the hardness adjusting tube 15b is the outer tube 1.
5 is located on the inner surface 15a, the target lesion portion 29
It is smooth to insert up. That is, the base end portion 15
Since d has no cut 15e, it is hard and can be easily pushed into the body. However, the spiral cuts 15e are gradually increased in density as they approach the tip portion 15c, and the cuts 15e become flexible. Therefore, the distal end portion 15c can be inserted into the target lesion portion 29 along the thin coronary artery 31.

Then, the aqueous solution of the contrast agent urographine is sent to the sleeve 9 through the outer tube 11 (for example, at 8 atm) to expand the sleeve 9 (step 6).
As a result, the drug-carrying layer 13 provided on the outer wall of the sleeve 9 is pressed by contacting the blood vessel, and the drug is released from the drug-carrying layer, that is, the water-absorbent polymer layer. Therefore, the drug can be given only to the lesioned part 29. After administration of the drug, the sleeve 9 is contracted, and the intravascular medication balloon catheter 1 is removed from the blood vessel.

According to the above-mentioned embodiment, the hardness adjusting tube 15 having the cut portions 15e formed at the tip portion 15c with a high density is formed.
Since b was placed on the inner surface 15a of the outer tube 15, a catheter that was hard at the proximal end 15d and flexible at the distal end 15c could be obtained. Therefore, even a thin and bent blood vessel can be inserted properly up to the target lesion portion 29 along the blood vessel.

The drug-carrying layer 13 is made of a water-absorbing polymer such as polyvinyl alcohol in this embodiment, but is not limited to this, and various liquid-absorbing layers (and releasing a liquid when pressurized), For example, a porous material such as a nylon nonwoven fabric or a foam having open cells can be used. Alternatively, as a balloon catheter for intravascular administration, the drug-carrying layer 1 is previously prepared before being inserted into the blood vessel.
Instead of the type of the above-described embodiment in which the drug is loaded on the catheter 3, a catheter of the type having no drug loading layer as described below may be used. That is, the outer tube 15 of the above embodiment
A drug guiding tube is provided on the outer side of the sleeve and a drug releasing sleeve is provided on the outer side of the sleeve 9, and the target lesioned portion 29
It may be a catheter of the type in which the drug is guided from the drug guiding tube to the drug releasing sleeve after the sleeve 9 is set in and the drug is released as the sleeve 9 expands. In this case, the hardness adjusting tube 15b
Can also be provided on the inner surface of the drug guiding tube or the outer surface of the outer tube 15. For example, the hardness adjusting tube 15b is applied to a catheter as described in Japanese Patent Publication No. 64-7090.

Although the hardness adjusting tube 15b is arranged on the inner surface 15a of the outer tube 15 in the above embodiment, the present invention is not limited to this as long as it does not have a disadvantageous effect. For example, the outer surface 7a of the inner tube 7 is provided. And inner surface 7b
It is also possible to place it in.

Further, in the above embodiment, the cut 15e is formed in a spiral shape, but the invention is not limited to this, and even in the vertical direction [FIG. 9 (a)] as shown in FIG. It may be [FIG. 9 (b)]. Further, as shown in FIG. 10, a large number of tubular bodies whose width becomes narrower toward the tip end may be closely arranged by making a turn in the lateral direction.

Further, in the above embodiment, the cut 15e is formed, but the meat pressure is obtained by a groove having a V-shaped cross section as shown in FIG. 11A or by thermocompression bonding as shown in FIG. 11B. The same effect can be obtained even if it is formed so as to be gently thin. Further, although the hardness adjusting tube 15b is applied to the intravascular drug delivery balloon catheter 1 in the above-mentioned embodiment, various balloon catheters without the drug carrying layer 13 or that the distal end portion is flexible and the proximal end portion is hard. Is, of course, applicable to all the various catheters that are desired.

The embodiment of the present invention has been described above.
The present invention is not limited to these examples, and it goes without saying that the present invention can be implemented in various modes without departing from the gist of the present invention.

[0031]

As described above, according to the catheter of the present invention, the distal end is flexible and the proximal end is hard, which is an excellent effect.

[Brief description of drawings]

FIG. 1 is a schematic front view showing the balloon catheter for intravascular administration of Example 1 with a sleeve inflated.

FIG. 2 is a partially enlarged view of the balloon portion 3.

FIG. 3 is an AA end view thereof.

FIG. 4 is a BB end view of the shaft portion.

FIG. 5 is a partially enlarged cutaway view thereof.

FIG. 6 is a C-C end view illustrating a bonded state of an outer tube and an inner tube at a boundary portion between a balloon portion and a shaft portion.

FIG. 7 is a front view of a hardness adjusting tube.

FIG. 8 is a schematic diagram showing a method of using the balloon catheter for intravascular administration of the present example.

FIG. 9 is a schematic diagram showing an example of a break other than the present embodiment.

FIG. 10 is a schematic view showing an example of still another break from this embodiment.

FIG. 11 is a schematic diagram illustrating a groove that is another example of the break in the present embodiment.

[Explanation of Codes] 1 ... Balloon catheter for intravascular administration, 3 ... Balloon part, 5 ... Shaft part, 7 ... Inner tube, 9 ... Sleeve, 13 ... Drug carrying part , 15
... Outer tube, 15b ... Hardness adjusting tube, 15c ... Hardness adjusting tube tip portion, 15
d ... Base end of the hardness adjusting tube, 15e ... Cut line.

Claims (3)

[Claims] 1. A catheter characterized in that a hardness adjusting tube having a cut formed therein, the density of which increases as it approaches the tip, is arranged in the catheter tube. 2. The catheter according to claim 1, wherein the hardness adjusting tube is formed by winding a ribbon having a thin distal end and a wide proximal end. 3. A catheter characterized in that a hardness adjusting tube having grooves formed therein, the density of which increases as it approaches the distal end portion, is arranged in the catheter tube.