JPH10337331A - Dilatation catheter - Google Patents

Abstract

(57) [Problem] To provide a relative position between an outer tube and an inner tube even when a catheter is bent at a highly bent portion, without meandering of the inner tube in the outer tube, Provided is a catheter having excellent operability without impairing the flexibility of the distal end portion. SOLUTION: This is a dilatation catheter having a multi-tube structure composed of an outer tubular member 2 and an inner tubular member 3, wherein a projecting protrusion 5a is formed on an outer peripheral surface of the inner tubular member 3.
Is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dilatation catheter used for an operation for dilatation operation, and more particularly to a dilatation catheter used at a highly bent portion and having a shape of a tubular member even when the catheter is bent. The present invention relates to a vascular dilatation catheter that maintains the relative positions of members and is excellent in operability.

[0002]

2. Description of the Related Art Dilatation catheters are mainly used for angioplasty treatment of stenotic or occluded blood vessels.
As shown in FIG. 7, a dilatation catheter, particularly a catheter generally called an over-the-wire type, has outer tubular members 21 and 22 having a plurality of lumens therein.
An expansion body (balloon) 24 connected to an expansion lumen for supplying a pressure fluid near the distal end of the catheter shaft composed of the inner tubular member 23 and a port 25 connected to each lumen near the base end; The expansion body 24 has a structure in which the expansion body 24 is folded with respect to the catheter shaft in a normal state. Then, during treatment, the dilatation body 24 of the dilatation catheter is inserted through the patient's artery into the stenosis site, where it is dilated by introducing pressure fluid into the dilation body 24 to expand the stenotic or occluded diseased part. Things.

[0003] The dilatation catheter is mainly inserted into a body passage to be treated, and dilation treatment is performed by introducing internal pressure at a treatment site. Therefore, the required functional properties are to have sufficient strength so that the expansion body is not broken when the pressure required for expansion is introduced, and to be able to safely control the expansion size to a desired size. In addition, since the internal passage is often bent, the distal end of the dilatation catheter is particularly flexible so that it can follow the bent internal passage, and the hand portion is capable of transmitting force to the distal end. Some strength is required so as to be good. In addition, one of the important properties is that the friction with the guide wire is small because the guide wire is usually used inside.

In many cases, particularly in the vascular system, it is necessary to insert a catheter along a blood vessel from an insertion port to a lesion or a predetermined site for that purpose. Is important. The operability, the shape and the relative position retention of each member will be described in detail.The catheter is generally composed of a tubular elongated member, and the catheter is operated from outside the body through the insertion port to bend the body. Or, it must pass through a narrowed and narrowed part. Therefore, the axial force applied from the outside of the catheter body and the rotating force must be effectively transmitted to the distal end of the catheter, and the shape and the relative position of each member can be retained so as to correspond to the bent portion. It needs flexibility, anti-kink properties.

[0005] In a multi-tube catheter, when a guide wire is passed through an inner tube, for example, in a cardiovascular dilatation catheter or the like, the outer tube has a proximal end of the expander and the inner tube has a distal end of the expander. In general, the inner tube is pushed by the tip of the expansion body, and the inner tube enters the outer tube and meanders, increasing the friction between the guide wire and the inner tube through which the guide wire is inserted. If the outer tube is deformed, the inner tube is pressed and the operability of the guidewire is reduced.

In order to achieve these improvements, Japanese Patent Laid-Open No.
172474, JP-A-3-51059, JP-A-4-23
In 63, a method is proposed in which the inner tubular member and the outer tubular member are fixed by the presence of a filler between them, but the location fixed by the filler is extremely stiff compared to the surroundings. This involves the problem of losing tip flexibility, which is an important property for a compromised catheter. Further, Japanese Patent Application Laid-Open No. 5-137793 proposes a method of adhering and fixing the inner tubular member to the outside without using a filler. However, in this method, the adhering portion is hardened similarly to the above, and In some parts, the guidewire is far away from the central axis of the catheter, that is, locally extremely eccentric, so that good operability may not be obtained. Furthermore, in the above method, since the tube members are fixed after being arranged, the steps are complicated and difficult.

[0007]

As described above, in the conventional catheter, when the catheter is bent at a highly bent portion, the inner tube for passing the guide wire is deformed and friction with the guide wire increases. Or
If the inner tube is partially eccentric or severe in the outer tube, the inner tube may meander in the outer tube, reducing operability, and attempts to improve them may not be possible. However, there is a problem that the operability is impaired due to a decrease in flexibility and concentricity. In view of such circumstances, the present invention is excellent in torque transmission characteristics and anti-kinking properties, and has a shape retention property even at a bent portion and a relative position retention property of each tube without impairing flexibility, and operability. An object of the present invention is to provide a dilatation catheter excellent in the above.

[0008]

According to the present invention, there is provided a dilatation catheter having a multi-tube structure in which a plurality of tubular members are arranged, and the projecting portion protrudes from a part of the outer peripheral surface of an inner tubular member. By providing the structure, even at the bent portion, the relative position of the outer tubular member and the inner tubular member is maintained without impairing the flexibility, and the local position of the inner tubular member in the outer tubular member is maintained. An object of the present invention is to provide a dilatation catheter which is free from extreme eccentricity and meandering and has excellent torque transmission, anti-kinking properties and operability.

That is, the present invention comprises a plurality of tubular members and an adapter member connected to their proximal ends.
A dilatation catheter comprising an expandable body disposed near their distal ends, wherein the entirety or distal side of the tubular member comprises an outer tubular member and at least one inner tubular member inside the outer tubular member. A dilatation catheter comprising a multi-tube structure having a structure protruding from a part of the outer peripheral surface of the inner tubular member.

In the present invention, the protruding structure includes:
A protrusion integrally formed on the outer peripheral surface of the inner tubular member, or welded or bonded thereto may be used. Although the shape of the protrusion is not particularly limited, two or more, preferably two to six protrusions having substantially the same height are provided on the outer peripheral surface of the inner tubular member at equal intervals or diagonally. The protrusion may or may not contact the inside of the outer tubular member.
Further, in order not to impair the flexibility, it is preferable that the length of the protrusion in the axial direction is as short as possible.
mm, preferably about 0.5 to 5 mm. The protrusion may be the same material as the inner tubular member or a different material, but when integrally molded, the same material is preferable. Also, when the material of the protrusion is made of a material different from the inner tubular member, in order not to impair the flexibility of the catheter,
It is preferable that the strength with respect to the tubular member is relatively low.

Further, as the protruding structure, a structure having a communicating property that does not impair the flexibility of the catheter and allows a liquid or a gas to pass therethrough may be provided on the outer peripheral surface of the outer tubular member. Examples of the material of such a communicating structure include a foam, a fiber, a sponge, and a porous plastic having a communicating property. The location of the inner tubular member provided with the protruding structure is not particularly limited, but is preferably provided relatively near the distal end, for example, near the expansion body. One or more protruding structures are provided.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. The dilatation catheter of the present invention comprises a plurality of tubular members, an adapter member connected to their proximal ends, and an expander disposed near their distal ends. That is, in FIG. 1, a tubular member 1a and an expansion body 4 are provided near the distal end of the tubular member 1a, and at a proximal end, the tubular member 1a has a relatively larger pull than the tubular member 1a. Outer tubular member 2 which is concentrically joined to tubular member 1b having an elastic modulus and comprises tubular members 1a and 1b
Inside, a tubular inner member 3 made of polyethylene is disposed, and a structure 5a protruding from the outer peripheral surface near the expansion body near the distal end of the tubular inner member 3 is provided. The inner tubular member 3 is concentrically joined to the expansion body 4 at the distal end of the expansion body 4, and an X-ray image is formed on the inner tubular member 3 at a position overlapping the expansion body 4. The gold or platinum annular member 6 is fixed. Further, the first lumen 7 of the inner tubular member 3 communicates with the port 9 of the adapter 8, and a second lumen 10 formed between the inside of the outer tubular member 2 and the outside of the inner tubular member 3 is formed. It communicates with the port 11 of the adapter 8.

As shown in FIG. 2, the projecting structure 5a is composed of a projection-like projection made of two diagonally provided projections 12 provided on the outer peripheral surface of the inner tubular member 3. ing. The protrusion is formed by various methods. For example, as shown in FIG. 3, a ceramic core material 13 having a diameter equal to the inner diameter of the inner tubular member 3 is provided at a predetermined location inside the inner tubular member 3. Insert
When the mold is heated by a high-frequency electromagnetic wave heating device or the like, the tube-shaped member is placed in a mold comprising a pair of concave molds 16 having a Teflon 14 on the outside and a brass mold 15 on the inside according to the protrusion 5a. 3 is melted, and a protrusion 5a having the protrusion 12 corresponding to the mold 15 is formed. In this case, by pre-crosslinking the tubular member 3 by irradiating it with an electron beam at a dose of about 100 kGy, the range of effective heating conditions for the tubular member 3 at the protruding portion forming portion is widened, and excessive deformation is suppressed. This is convenient.

As still another example, a small piece of polyethylene made of the same material as that of the tubular member 3 is placed in the mold 15 in advance, and the inside of the tubular member 3 A ceramic core material 13 having a diameter equal to the inner diameter of the member 3 is inserted into the determined location, placed in the same mold as above, and heated by a high-frequency electromagnetic wave heating device or the like, so that a projection corresponding to the mold 15 is formed. 1
2 are formed. Also in this case, it is preferable to introduce crosslinks into the tubular member 3 in advance by irradiating an electron beam with a dose of about 100 kGy, since excessive deformation is suppressed.

FIGS. 4 and 5 show another embodiment of the present invention. Similar to the above-described embodiment, a structure protruding from the outer peripheral surface near the expansion body near the distal end of the inner tubular member 3 is shown. 5b is provided. Other configurations are the same as those in the above embodiment. The protruding structure 5b is formed of an S-shaped helical protrusion. The S-shaped helical protrusion is formed by, for example, applying a primer (organic amine) to a predetermined position of the inner tubular member 3 made of polyethylene. A surface treatment is performed, and an adhesive having a viscosity of 500 cst (ethyl cyanoacrylate 90 to 95% by weight, polymethyl methacrylate 5 to 10% by weight, hydroquinone about 0.
By moving the mixture (5% by weight) in the axial direction of the tubular member 3, it can be formed on the tubular member 3.

FIG. 6 shows still another embodiment of the present invention. Similar to the above embodiment, a structure 5c protruding from the outer peripheral surface near the expansion body near the distal end of the inner tubular member 3 is provided. ing. Other configurations are the same as those in the above embodiment. The protruding structure 5c is made of a structure having communication, and can be provided, for example, by the following method. That is, a polyether type urethane elastomer and polyvinyl alcohol having a particle size of about 100 microns are mixed with a 1: 1 mixed solution of dioxane and dimethylacetamine while performing a defoaming treatment to adjust the viscosity to 11st. A predetermined position of the inner tubular member 3 made of polyethylene is subjected to surface treatment by corona discharge,
While rotating the mixture, the above polyether-type urethane elastomer / polyvinyl alcohol mixture was supplied onto the tubular member 3 by a dispenser, and the polyether-type urethane elastomer-polyvinyl alcohol mixture was applied. Thereafter, the coated portion is immediately put into a coagulating liquid composed of a 30% aqueous solution of ethylene glycol to coagulate the coated material. Next, the tubular member 3 having the solidified coating material
Is treated in hot water at 90 ° C. to remove polyvinyl alcohol, and a protruding structure 5 composed of a polyurethane network structure
c is constructed on the outer peripheral surface of the tubular member 3.

[0017]

As described above, the dilatation catheter of the present invention can be used without impairing the flexibility required for the catheter.
Since the shapes of the outer tubular member and the inner tubular member and the relative positions of these tubular members are maintained, there is no local extreme eccentricity or meandering of the inner tubular member in the outer tubular member. Good operability can be obtained even when inserted and used in a damaged portion, and torque transmission and anti-kink properties are also good. Further, the dilatation catheter of the present invention is extremely advantageous industrially because it is only necessary to previously form a structure protruding from the outer peripheral surface of the inner tubular member by processing and insert it into the outer tubular member.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an embodiment of a dilatation catheter of the present invention.

FIG. 2 is an enlarged sectional view of a main part taken along line II-II of FIG.

FIG. 3 is an explanatory view of a method for forming a protruding structure used in the present invention.

FIG. 4 is a schematic sectional view showing another embodiment of the dilatation catheter of the present invention.

FIG. 5 is an enlarged sectional view of a main part of FIG.

FIG. 6 is a schematic sectional view showing still another embodiment of the dilatation catheter of the present invention.

FIG. 7 is a schematic sectional view showing a conventional dilatation catheter.

[Explanation of symbols]

1a, 1b Tubular Member 2 Outer Tubular Member 3 Inner Tubular Member 4 Expanded Body 5a Projected Structure (Protruded Projection) 5b Projected Structure (S-Shaped Spiral Projection) 5c Projected Structure (Communication Structure) 6) annular member 7 first lumen 8 adapter 9 port 10 second lumen 11 port 12 protrusion 13 ceramic core material 14 Teflon portion 15 brass mold 16 concave mold

Claims (4)

[Claims] 1. A dilatation catheter comprising a plurality of tubular members, an adapter member connected to their proximal ends, and an expander disposed near their distal ends. The whole or distal side of the member has a multi-tube structure including an outer tubular member and at least one inner tubular member inside thereof, and has a structure protruding from a part of the outer peripheral surface of the inner tubular member. A dilatation catheter, characterized in that: 2. The dilatation catheter according to claim 1, wherein the projecting structure is formed integrally with the outer peripheral surface of the inner tubular member. 3. The dilatation catheter according to claim 1, wherein the projecting structure is welded or adhered to the outer peripheral surface of the inner tubular member. 4. The dilatation catheter according to claim 1, wherein the protruding structure is a communicating structure provided on an outer peripheral surface of the outer tubular member.