JP3357416B2 - catheter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a catheter.

[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 a body and performs diagnosis, treatment, and the like. In this catheter, it is important from the viewpoint of its function that it can be bent and inserted along a guide wire or a blood vessel to a predetermined site in the body.

However, in a conventional catheter,
In order to be able to push into a predetermined part in the body, the hardness was relatively high. For this reason, when the tip is finally inserted into a thin portion, for example, a thin blood vessel, it cannot be bent well, and it is difficult to insert the catheter to a predetermined portion. Conversely, when the catheter is made of a flexible material, it is easy to bend at a thin site, but it has been difficult to push the catheter into the body at the base end.

[0004] From this viewpoint, there has been proposed a catheter in which a gold wire having a uniform thickness is densely wound to maintain the hardness and freely bend.

[0005]

However, in the catheter wound with the gold wire, the flexibility is slightly improved, but the overall hardness is still uniform.
For this reason, if it has sufficient hardness to be pushed into the body, the tip is too hard to be successfully inserted into the narrow part as described above.

Accordingly, an object of the present invention is to solve the above-mentioned problems and to provide a catheter having a flexible distal end and a rigid proximal end.

[0007]

According to the present invention , there is provided a catheter comprising:
The synthetic resin outer tube is inserted into the lumen of the synthetic resin outer tube.
With the structure through the inner tube, the outer tube
A gap is formed between the inner tube and the inner tube.
That the catheter tube, it and a hardness adjusting tube cuts or grooves density increases is formed gets closer to the tip portion, the hardness adjustment tube, synthesis
The inner surface of the outer tube, the inner
Outer surface of the inner tube, or inside the inner tube
It is characterized by being arranged on one of the surfaces .

[0008]

[0009]

The catheter of the present invention is made of a synthetic resin outer
Insert the inner tube made of synthetic resin into the lumen of the tube.
Further, a hardness adjusting tube made of a synthetic resin is disposed on one of the inner surface of the outer tube, the outer surface of the inner tube, and the inner surface of the inner tube. In the hardness adjusting tube, the density of the cuts or grooves differs depending on the position, so that the hardness differs depending on the position. In other words, since the density of the cuts or grooves is high at the tip, fine bending is free and flexible.
On the other hand, at the proximal end, the density of cuts or grooves is low or zero, so that sufficient hardness is maintained for the operation of inserting the catheter into the body. Therefore, the hardness can be freely changed according to the position by changing the density of the cuts or grooves as desired. For example, by gradually changing the density of the cuts or grooves, the hardness can be changed continuously. For this reason, it was possible to obtain a catheter having a flexible distal end and a rigid proximal end with a very simple configuration such as simply disposing a hardness adjusting tube having a cut or groove formed therein.

The cuts or grooves need only be provided in directions and positions that are easy to bend depending on the application, and may be oriented in any of vertical, horizontal and diagonal directions, and may be formed irregularly in various directions. May be used. Further, the cut may be formed by winding a ribbon having a narrow distal end and a wide base end without forming the cut by cutting. The groove refers to a portion where the cross section is not completely cut and a part of the body pressure is reduced, and the shape may be a U-shaped cross section, a V-shaped cross section, or a straight cut. It may be a material that has been formed, or a material that is formed to be thin gradually by using a pressure bonding technique.

As the material of the tube for adjusting the 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 And the like .

The wall pressure of the hardness adjusting tube may be determined as desired in accordance with the wall pressure of the catheter to be applied, the hardness of the hardness adjusting tube itself, and the like.
It is preferably from 0.3 to 0.3 mm, particularly preferably 0.05 mm. The length of the tip for forming 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. that's all,
Particularly, in a catheter having a total length of 135 cm, the length is preferably 30 cm.

As a 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 and the like can be mentioned.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in order to further clarify the configuration and operation of the present invention described above. [Embodiment 1] FIG. 1 is a schematic front view showing an intravascular medication balloon catheter 1 of this embodiment in a state where a balloon portion 3 is inflated. The intravascular medication 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 at the center. The inner tube 7 is used to insert a guide wire for guiding the balloon portion 3 to an appropriate site by inserting the inner tube 7 into a blood vessel. The inner tube 7 may be made of any conventionally known material, and examples thereof include polyethylene, polypropylene, polyamide, polyacetal, and fluorine-based resin.

As shown in the AA end view of FIG. 3, the inner tube 7 has a hollow cylindrical shape when inflated (see FIG. 3A), and a wing shape when contracted [see FIG.
(See (b)). In practice, the wing-shaped sleeve 9 is folded around the inner tube 7 on contraction in a suitable way, for example artificially or by creasing or hammering the material. The distal end 11 of the balloon portion 3 is adhered or adhered so that the inner tube 7 and the sleeve 9 are not separated by pressurization. In addition, it has an appropriate shape and hardness so as to facilitate insertion and movement into the blood vessel, to move the inside of the blood vessel by being inserted into the blood vessel from the outside, and not to damage the blood vessel. On the outer surface 7a of the inner tube 7 inside the balloon portion 3, a marker 12 for detecting that the inner tube 7 has reached an appropriate site (that is, a lesion) is annularly arranged. The marker 12 is made of a radiopaque material such as Au or P.
t.

A drug carrying layer 13 is provided on the outer wall of the sleeve 9. The drug-carrying layer 13 is a layer of a water-absorbing polymer, which absorbs a drug by impregnation, but releases little or no drug under normal pressure, and
Has the property of releasing a drug by contacting with a diseased part due to the expansion of the drug. In this example, polyvinyl alcohol was used, but polymers having such properties include, for example, carboxymethyl cellulose, polyacrylic acid, sodium polyacrylate, polyacrylamide, and the like, and can be used equally.

As shown in the BB end view in FIG. 4 and the partially enlarged cut-away view in FIG. 5, the shaft portion 5 has an inner tube 7 penetrated by the balloon portion 3 at the center portion. An outer tube 15 concentric with the inner tube 7 is provided outside 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 a pressure, for example, a liquid from the external pressure supply means to the sleeve 9. The outer tube 15 and the inner tube 7
As shown in the CC end view in FIG. 6, a thermoplastic resin 16 is adhered at a boundary portion between the balloon portion 3 and the shaft portion 5, and a sleeve 9 is attached to a part of the thermoplastic resin 16.
Is provided with a hole 16a through which a liquid can be passed. Therefore, the space in the outer tube 15 and the hollow in the sleeve 9 are continuous by the 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 acrylate 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 an adhesive. As shown in a front view of FIG. 7, the hardness adjusting tube 15b has a spiral cut 15e at the distal end 15c (30 cm) that gradually widens (that is, decreases in density) toward the proximal end 15d. The remaining base end 15d (105 cm) is a tubular body. Here, the cut 15e is formed in the tube 1 for adjusting the hardness of the cylindrical body.
5b, the cutter is applied to the hardness adjusting tube 15b, and the moving speed of the cutter is reduced to the tip 1.
It can be formed by gradually slowing down from 5c toward the base end 15d. Alternatively, a break 15e
May be formed by spirally winding ribbon-shaped nylon, which is narrow at the distal end 15c and gradually widens toward the proximal end 15d. In the present embodiment, the nylon hardness adjusting tube 15b is used, but the present invention is not limited to this. Polypropylene, polyacetal, polyethylene, polyester, polycarbonate,
Polyurethane or the like can be equally applied.

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

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

The sheath 23 is inserted into the femoral artery 21, the guide catheter 25 is inserted through the sheath 23, and the entrance 27 of the coronary artery 31 having the lesion 29 to be treated (shown by an enlarged dashed line). (Step 3). Next, the intravascular medication balloon catheter 1 into which the guide wire 19 has been inserted is inserted from the guide catheter 25 (step 4). The intravascular medication balloon catheter 1 is set at the target lesion 29 with the guidewire 19 preceding the entrance 27 of the coronary artery (step 5).

Here, in the balloon catheter 1 for intravascular administration, the hardness adjusting tube 15b is
5, the target lesion 29
It is smooth to insert up. That is, the base end 15
Since d has no cut 15e, it is hard and can be easily pushed into the body. However, the spiral cut 15e is gradually formed with a high density as approaching the distal end portion 15c, so that the spiral cut 15e becomes flexible. Therefore, the distal end portion 15c can be inserted into the target lesion 29 along the thin coronary artery 31.

Then, an aqueous solution of the contrast agent urografin is sent (for example, at 8 atm) to the sleeve 9 via the outer tube 11 to expand the sleeve 9 (step 6).
As a result, the drug-carrying layer 13 provided on the outer wall of the sleeve 9 comes into contact with the blood vessel and is pressed, so that the drug is released from the drug-carrying layer, that is, the water-absorbing polymer layer. Therefore, the medicine can be given only to the lesion 29. After administration of the drug, the sleeve 9 is contracted, and the intravascular medication balloon catheter 1 is withdrawn from the blood vessel.

According to the above-described embodiment, the hardness adjusting tube 15 in which the notch 15e is formed at a high density at the end portion 15c.
Since b was arranged on the inner surface 15a of the outer tube 15, the catheter was hard at the proximal end 15d and flexible at the distal end 15c. For this reason, even if it is a thin and bent blood vessel, it can be successfully inserted to the target lesion 29 along the blood vessel.

In the present embodiment, the drug-carrying layer 13 uses a water-absorbing polymer, for example, polyvinyl alcohol. However, the present invention is not limited to this. 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 may be used in advance before being inserted into a blood vessel.
In addition to the type of the above-described embodiment in which the drug is supported on 3, a catheter having no drug-supporting 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 outside of the sleeve 9 and a drug releasing sleeve is provided on the outside of the sleeve 9.
After the sleeve 9 has been set, the catheter may be of a type in which the drug is guided from the drug guide tube to the drug release sleeve, and the sleeve 9 is expanded to release the drug. In this case, the hardness adjusting tube 15b
May be provided on the inner surface of the drug guiding tube or the outer surface of the outer tube 15. For example, a hardness adjusting tube 15b is applied to a catheter described in Japanese Patent Publication No. 4-64709.

In the above embodiment, the hardness adjusting tube 15b is disposed on the inner surface 15a of the outer tube 15. However, the hardness adjusting tube 15b is not limited to this as long as an adverse effect does not occur. And inner surface 7b
It is also possible to arrange in.

Further, in the above-described embodiment, the cut 15e is formed in a spiral shape. However, the present invention is not limited to this. Even if the cut 15e is in the vertical direction as shown in FIG. [FIG. 9 (b)]. Further, as shown in FIG. 10, a plurality of cylindrical bodies having a width narrowing toward the distal end portion may be densely arranged by making a round in the transverse direction cut.

Further, in the above-described embodiment, the cut 15e is formed. However, the pressure is formed by a groove having a V-shaped cross section as shown in FIG. 11A or a thermocompression bonding as shown in FIG. 11B. The same effect can be obtained even if is formed slowly and thinly. Further, in the above embodiment, the hardness adjusting tube 15b is applied to the intravascular administration balloon catheter 1. However, various balloon catheters having no drug carrying layer 13 or a flexible distal end and a rigid proximal end are used. Can, of course, be applied to all the various catheters desired.

The embodiments of the present invention have been described above.
The present invention is not limited to these embodiments at all, 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, there is an excellent effect that the distal end is flexible and the proximal end is hard.

[Brief description of the drawings]

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

FIG. 2 is a partially enlarged view of the balloon section 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 CC end view for explaining a bonding state between 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 view showing a method of using the intravascular medication balloon catheter of the present embodiment.

FIG. 9 is a schematic diagram showing an example of another break from the present embodiment.

FIG. 10 is a schematic diagram showing still another example of a break in the present embodiment.

FIG. 11 is a schematic diagram for explaining a groove which is another example of a break in the present embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Balloon catheter for intravascular administration, 3 ... Balloon part, 5 ... Shaft part, 7 ... Inner tube, 9 ... Sleeve, 13 ... Drug carrier part, 15
··· Outer tube, 15b ··· Hardness adjusting tube, 15c ··· Tip of hardness adjusting tube, 15
d: Base end of the hardness adjusting tube, 15e: Cut.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) A61M 25/00 A61M 25/09

Claims (2)

(57) [Claims] 1. Inside the lumen of an outer tube made of synthetic resin
With a structure in which an inner tube made of synthetic resin is passed through,
A gap between the outer tube and the inner tube
Formed with a catheter tube, and a hardness adjusting tube formed with a cut or groove whose density increases as approaching the distal end portion, wherein the hardness adjusting tube is made of synthetic resin, Of outer tube
Inner surface, outer surface of the inner tube, or the inner tube
A catheter disposed on one of the inner surfaces of the tube . 2. The catheter according to claim 1, wherein the hardness adjusting tube is formed by winding a ribbon having a narrow distal end and a wide proximal end.