JPH06319804A - Balloon catheter - Google Patents

Abstract

PURPOSE:To provide the balloon catheter having a soft front end part, with which an inner tube and a sleeve come into tight contact. CONSTITUTION:This balloon catheter for dosing in blood vessels has the sleeve 9 which is expandable and shrinkable by a pressure from the outside, a drug carrying layer 13 consisting of a water absorptive polymer disposed across the outside wall of the sleeve 9 and the inner tube which is arranged through the outer tuber and the sleeve 9a and into which a guide wire is inserted. The front end 11 with which the inner tube and the sleeve 9 come into tight contact is provided with a soft part 11b formed with plural holes 11a penetrating the inner tube and the sleeve 9 radially from the center. The sleeve 9 is inserted down to the prescribed part by well curving the front end 11 even at the time of inserting the front end 11 into the slender part, for example, the fine blood vessel, etc., in the final.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to balloon catheters.

[0002]

2. Description of the Related Art A balloon catheter has a sleeve that can be inflated and deflated at its tip, and the sleeve is inflated and inserted into a predetermined site such as a lesion in the body, and then the sleeve is inflated for diagnosis. , A tube member for performing treatment and the like. From the function of this balloon catheter, it is important that the sleeve can be inserted into a predetermined portion in the body by being bent properly along the guide wire or the blood vessel.

[0003]

However, at the tip of the balloon catheter, the inner tube through which the guide wire is inserted and the sleeve are in close contact with each other so that the medium for expanding the sleeve does not leak out from the inside of the sleeve. Therefore, the hardness of the closely contacted portion was relatively high. As a result, when the tip is finally inserted into a thin portion, for example, a thin blood vessel, it cannot be bent properly, and it is difficult to insert the sleeve to a predetermined portion.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above problems and to provide a balloon catheter having a flexible distal end portion in which the inner tube and the sleeve are in close contact with each other.

[0005]

A balloon catheter according to the present invention comprises a sleeve that can be inflated and deflated by pressure supplied from the outside, an outer tube that serves as a path for supplying pressure to the sleeve, the outer tube, and the outer tube. In a balloon catheter provided through an inner tube through which a guide wire is inserted, the distal end of which is disposed through the sleeve and which is in close contact with the sleeve, in at least one of the inner tube and the sleeve in a close contact portion, It is characterized in that a flexible portion having flexibility is provided by forming the material in a shape with a part thereof removed.

[0006]

According to the balloon catheter of the present invention, the flexible portion is provided on at least one of the inner tube and the sleeve at the tip portion where the inner tube and the sleeve, which are relatively hard portions, are in close contact with each other. . This flexible portion is made to have flexibility by having a shape obtained by partially removing the material. That is, when the material is formed into a shape in which a part thereof is deleted, a part of the wall thickness is thinned, or a space is generated in the wall thickness to improve flexibility and be flexible.

The "shape obtained by partially removing the material" means a plurality of holes penetrating the inner tube and the sleeve, a plurality of holes axially penetrating the inner tube in the close contact portion, cracks, grooves, or Examples thereof include recesses formed on the entire inner circumference. Therefore, even when the tip is finally inserted into a thin portion, for example, a thin blood vessel, the tip can be properly bent and the sleeve can be inserted up to a predetermined portion.

[0008]

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 end view of the balloon portion 3 in FIG. 2, an inner tube 7 penetrates through the central 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 of 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 portion 11 of the balloon portion 3 is in close contact with the inner tube 7 and the sleeve 9 so as not to separate from each other due to pressure. Then, as shown in FIG. 4 which is a partially cutaway enlarged front view and FIG. 5 which is a BB cross-sectional view thereof, a distal end portion 11 in which the inner tube 7 and the sleeve 9 are adhered to each other is shown.
The flexible portion 11 has a plurality of holes 11a penetrating the inner tube 7 and the sleeve 9 formed radially from the center.
b is provided. The holes 11a can be formed by any means such as a thermal laser, an excimer laser, and a drill. The size of the hole 11a is appropriately set according to the length of the inner tube 7 and the sleeve 9 in close contact with each other, the wall thickness, and the desired flexibility, but is preferably 10 μm.
~ Several hundred μm.

Further, on the outer surface 7a of the inner tube 7 inside the balloon portion 3, a marker 12 for detecting the arrival at an appropriate portion (that is, a lesion portion) is annularly arranged. The marker 12 is a radiopaque material such as A
It is composed of u and Pt.

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-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 enlarged end view CC of FIG. 6 and the partially enlarged cutaway view of FIG. 7, the shaft portion 5 is followed by the inner tube 7 which is penetrated by the balloon portion 3 in the central portion. An outer tube 15 is provided that is penetrated and is concentric with the inner tube 7 on the outer side thereof.
Note that, in FIG. 7, hatching showing a cross section is omitted. 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. Outer tube 15 and inner tube 7
As shown in the enlarged end view DD of FIG. 8, the thermoplastic resin 1 is provided at the boundary between the balloon portion 3 and the shaft portion 5.
6 is bonded, and a hole 16a through which a liquid for expanding the sleeve 9 can pass is provided in a part of the thermoplastic resin 16. 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,
Examples thereof include polyacetal and polyurethane.

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. 9, the hardness adjusting tube 15b has a spiral portion 15e (30 cm) having a gradually widening width (that is, a lower 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. 10 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 (enlarged view by a one-dot 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 31 (step 5).

Here, in the balloon catheter 1 for intravascular administration, a plurality of holes 11a penetrating the inner tube and the sleeve are formed in the tip portion 11 where the inner tube and the sleeve, which are relatively hard parts, are in close contact with each other. The formed flexible portion 11b is provided. That is, the tip 1
No. 1 is flexible because its flexibility is improved by the flexible portion 11b having a space in its thickness. Therefore, the distal end portion 11 can be bent along the inside of the thin coronary artery 31 and can be successfully inserted up to the target lesion portion 29.

Further, since the hardness adjusting tube 15b is arranged on the inner surface 15a of the outer tube 15,
The target lesion site 2 is the entire balloon catheter 1 for intravascular administration.
Inserting up to 9 is smooth. That is, the base end 1
Since 5d 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, it is easier to insert the distal end portion 15c along the narrow coronary artery 31 to the target lesion portion 29.

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-described embodiment, the plurality of holes 11a penetrating the inner tube 7 and the sleeve 9 are formed in the tip portion 11 where the inner tube 7 and the sleeve 9 which are relatively hard parts are in close contact with each other. By providing the flexible portion 11b described above, the flexible catheter of the distal end portion 11 can 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.

In the above embodiment, a plurality of holes 11a penetrating the inner tube 7 and the sleeve 9 are formed as the flexible portion 11b, but the shape is not limited to this as long as the material is partially deleted. Further, even if the flexible portion 11b is not formed on both the inner tube 7 and the sleeve 9 of the tip portion 11 that are in close contact with each other, the inner tube 7
Alternatively, at least one of the sleeves 9 has a flexible portion 11b.
Should be provided. For example, as shown in FIG. 11A, a partially cutaway enlarged front view and FIG. 11B a side view thereof,
Flexible portion 11 having a plurality of holes 11c penetrating the inner tube 7 of the tip portion 11 in close contact with each other in the axial direction.
It may be d. Alternatively, as shown in a partially enlarged sectional view of FIG. 12 (a) and a side view of FIG. 12 (b), by cutting the inner tube 7 by a predetermined distance from the most distal end portion 11e toward the proximal direction. As shown in a partially cutaway enlarged front view showing the inner tube 7 by breaking the sleeve 9 in FIG. 13 or the flexible portion 11g having the split 11f, the inner tube 7 of the tip 11 which is in close contact with the inner tube 7 is spiraled. It may be a flexible portion 11i having a crack 11h. Further, as shown in the side view of FIG. 14, it may be a flexible portion 11k having a plurality of grooves 11j formed in the axial direction. Alternatively, as shown in a partially enlarged sectional view of FIG.
It may be the flexible portion 11p in which is formed. Flexible parts 11b, 11d, 11g, 11i, 11k, 1 as described above
Any of 1p can be easily manufactured.

The drug-carrying layer 13 is made of a water-absorbing polymer such as polyvinyl alcohol in the present embodiment, but is not limited to this, and various liquid-absorbing layers (and releasing liquid when pressurized), For example, a porous material such as a nylon nonwoven fabric or a foam having open cells can be used. Alternatively, before inserting the intravascular drug delivery balloon catheter 1 into the blood vessel, a drug guiding tube is provided outside the outer tube 15 and the target lesion site 29 is sleeved even if the drug carrying layer 13 is not loaded with the drug in advance. Alternatively, after the 9 is set, the drug may be guided from the drug guiding tube to the drug carrying layer so that the sleeve 9 is expanded and the drug is released. 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. Further, the hardness adjusting tube 15b may not be provided if necessary.

Further, in the above-mentioned embodiment, the present invention is applied to the balloon catheter 1 for intravascular administration, but it is needless to say that it can be applied to all various balloon catheters having no drug carrying layer 13. For example, a PCTA balloon catheter, a PTA balloon catheter, an IABP balloon catheter, etc. are mentioned.

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.

[0027]

As described above, according to the balloon catheter of the present invention, the tip portion where the inner tube and the sleeve are in close contact is flexible. Therefore, even when the tip is finally inserted into a thin portion, for example, a thin blood vessel, the tip can be properly bent and the sleeve can be inserted up to a predetermined portion.

[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 end view of the balloon portion 3.

FIG. 3 is an AA end view thereof.

FIG. 4 is a partially cutaway enlarged front view of the distal end portion of the balloon portion.

FIG. 5 is a BB sectional view thereof.

FIG. 6 is a C-C enlarged end view of the shaft portion.

FIG. 7 is a partially enlarged cutaway view thereof.

FIG. 8 is a DD enlarged end view for explaining the bonding state of the outer tube and the inner tube at the boundary portion between the balloon portion and the shaft portion.

FIG. 9 is a front view of a hardness adjusting tube.

FIG. 10 is a schematic view showing a method of using the balloon catheter for intravascular administration of the present example.

FIG. 11 is an explanatory diagram showing an example of a flexible portion, which is different from this embodiment.

FIG. 12 is an explanatory diagram showing an example of a flexible portion, which is still another example of the present embodiment.

FIG. 13 is an explanatory diagram showing an example of a flexible portion, which is still another example of the present embodiment.

FIG. 14 is an explanatory diagram showing an example of a flexible portion, which is still another example of the present embodiment.

FIG. 15 is an explanatory diagram showing an example of a flexible portion, which is another example of the present embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Balloon catheter for intravascular medication, 3 ... Balloon part, 5 ... Shaft part, 7 ... Inner tube, 9 ... Sleeve, 13 ... Drug support part, 11
... Tip of balloon part, 11a, 11c ... Hole,
11b, 11d, 11g, 11i, 11k, 11p ...
・ Flexible parts, 11f, 11h ... Cracks, 11j ...
Groove, 11n ... Recess, 15 ... Outer tube.

Claims (6)

[Claims] 1. A sleeve that is expandable / contractible by a pressure supplied from the outside, an outer tube that serves as a path for supplying a pressure to the sleeve, and is disposed through the outer tube and the sleeve, and the tip thereof is the sleeve. In a balloon catheter provided with an inner tube through which a guide wire is inserted, which is in close contact with the inner tube, at least one of the inner tube and the sleeve in the intimate contact portion is formed by partially removing the material. A balloon catheter characterized in that a flexible portion having greater flexibility is provided. 2. The balloon catheter according to claim 1, wherein the shape in which the material of the flexible portion is partially removed is a plurality of holes penetrating the inner tube and the sleeve. 3. The balloon catheter according to claim 1, wherein the shape in which the material of the flexible portion is partially removed is a plurality of holes that axially penetrate the inner tube in the closely contacting portion. 4. The balloon catheter according to claim 1, wherein the shape in which the material of the flexible portion is partially removed is a crack. 5. The balloon catheter according to claim 1, wherein the shape in which the material of the flexible portion is partially removed is a groove. 6. The balloon catheter according to claim 1, wherein the shape in which the material of the flexible portion is partially removed is a concave portion formed on the entire inner circumference.