JPH0759861A - Catheter - Google Patents

Abstract

PURPOSE:To provide the catheter which has excellent operability, less damages the blood vessels and has excellent safety by specifying the bending elasticity and curvature of a liquid crystal polymer alloy for orienting a resin inside layer joined with a resin outside layer via a reinforcing material layer in a longitudinal direction and a catheter body to specific values. CONSTITUTION:The catheter body is internally formed with a pipe cavity 3 from its base end toward its front end. The main part of the catheter consists of the resin inside layer 4, the reinforcing material layer 5 tightly joined to the outer side thereof and the resin outside layer 6. The reinforcing layer 5 is constituted by forming wires to a lattice, stranded wire, spiral or braided structure form along the longitudinal direction of the catheter and, therefore, the resin inside layer 4 is composed of a material consisting of the liquid crystal polymer alloy and having relatively large rigidity and the resin outside layer 6 is constituted of a relatively soft material. The bending elasticity (ASTM D-790, 23 deg.C) of the catheter body part having the resin inside layer 4 is specified to >=200g and the curvature of the catheter body to <=15mm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a catheter used, for example, for percutaneously inserting a catheter into a blood vessel to diagnose a lesion involving the blood vessel by angiography or for treatment by injecting a drug.

[0002]

2. Description of the Related Art Diagnosis and treatment of lesions involving blood vessels have become popular by percutaneously inserting a catheter into blood vessels without performing a surgical operation. When performing selective angiography or vasodilation. An imaging catheter, a guiding catheter, a dilatation catheter, etc. are generally used for the. Such a catheter is required to have operability so that it can be quickly and surely inserted into a vascular system having a thin and complicated shape and structure.

This operability will be described in detail. In addition to the so-called pushability by which the pushing force of the operator for inserting the catheter in the blood vessel can be reliably transmitted from the base side of the catheter to the distal side, the proximal side of the catheter is added. The torque transmissibility capable of reliably transmitting the generated rotational force to the distal end side, and the followability capable of proceeding smoothly in the curved blood vessel along the preceding guide wire and without damaging the inner wall of the blood vessel (hereinafter referred to as "guide wire"). "Following" or simply "following")
Therefore, it is necessary to have kink resistance so that the catheter does not bend even at the curved / bent portion of the blood vessel even after the catheter tip reaches the target portion and the guide wire is removed.

It is known that, in order to obtain good pushability and torque transmission, it is preferable that the portion excluding the distal end of the catheter tube is made of a relatively rigid material.
On the other hand, since the tube is made of a rigid material, the kink resistance tends to be inevitably lowered, and a suitable balance between the two is desired.

In recent years, there has been an increasing demand for a catheter tube having a smaller diameter also in order to improve the non-invasiveness of the catheter. That is, when puncturing a patient's skin with a catheter, the catheter tube has seemingly contradictory requirements. That is, it is more non-invasive to use a catheter tube that is as thin as possible, while it is necessary to have a cross-sectional area as large as possible when injecting a contrast agent or the like into the catheter lumen. Required. Particularly in the field of microcatheter, the bending elasticity, which has not been a problem in the case of a large-diameter catheter, tends to decrease to a non-negligible level due to its smaller diameter.

Therefore, in such a catheter, the bending rigidity of the main part of the shaft at the same level as that required for a large-diameter catheter is required.

In the conventionally known catheters, polyurethane is generally used as the constituent material of the catheter tube.
Known are resin tubes such as polyamide, polyester elastomer, and fluorinated polyethylene propylene copolymer, or multilayer tubes in which these resins are coated in multiple layers. Furthermore, a combination of these resin tubes in which a stainless wire or the like is reinforced with a blade has been proposed. However, all the catheters made of the resin materials mentioned above are relatively soft resins, and have a bending rigidity sufficient for practical use as a catheter having a relatively large diameter. The diameter of a catheter, particularly a catheter having a size of 4 French or less, is often too low to ensure sufficient operability as a catheter.

[0008]

An object of the present invention is to provide excellent operability such as pushability, followability, and kink resistance, little vascular damage, and excellent safety, especially for a technique for a thin blood vessel. Is to provide a suitable catheter.

[0009]

Such an object is achieved by the catheter according to the present invention described in (1) to (10) below.

(1) In a catheter having a portion in which a resin inner layer and a resin outer layer are joined via a reinforcing material layer,
The inner resin layer is substantially made of a liquid crystal polymer alloy oriented in the length direction.

(2) In the catheter described in (1), the liquid crystal polymer alloy is in the form of an alloy containing the liquid crystal polymer alone or mixed with a compatible resin.

(3) In the catheter described in (1) or (2), the reinforcing material layer is a linear body formed in a lattice shape, a stranded wire shape, a spiral shape, or a knitted structure shape along the axis of the catheter body. It is composed.

(4) In the catheter described in (1) to (3), the resin outer layer is made of a thermoplastic resin or the resin outer layer is made of a thermosetting resin.

(5) In the catheters described in (1) to (4), the bending elasticity F of the catheter body is 200 g or more.

(6) In the catheter described in (1) to (5), the bending ratio D of the catheter body is 15 mm or less.

(7) In the catheter described in (1) to (6), the outer resin layer projects by a predetermined length from the tip of the inner resin layer. (8) In the catheter described in (1) to (7) A base portion in which the outer diameter of the catheter body is substantially constant in the longitudinal direction, and an intermediate portion in which the outer diameter of the catheter body gradually decreases toward the distal end, and only the resin outer layer that is more flexible toward the distal end than the intermediate portion And a tip portion having an outer diameter gradually decreasing toward the tip is formed.

(9) A catheter is formed by coating a core wire made of a metal wire with a resin inner layer made of a liquid crystal polymer alloy, forming a reinforcing material layer on the outer periphery of the core wire, and then covering the resin outer layer, and then pulling out the core wire. And a withdrawal rate of the resin inner layer made of the liquid crystal polymer alloy at the time of coating is three times or more.

(10) In the catheter manufacturing method described in (9), the outer resin layer is subjected to a surface treatment for improving adhesion with the inner resin layer and / or the reinforcing material layer,
To be covered.

In the catheter of the present invention, the main part of the catheter body is composed of a plurality of resin layers which are a combination of a highly rigid resin inner layer made of a liquid crystal polymer alloy and a less rigid resin outer layer. Further, a reinforcing material layer is provided along the axis of the catheter body as an intermediate layer configured in a lattice shape, a twisted wire shape, a spiral shape, or a knitting structure. In addition to imparting sufficient rigidity, the main part of (1) is imparted with excellent pushability and torque transmissibility, and the kink resistance is improved.

In a further preferred embodiment, since the outer layer projects a predetermined length from the tip of the inner layer to form a flexible catheter tip, not only ordinary arteries and veins having a relatively large diameter but also, for example, cerebral blood vessels. It exhibits excellent pushability, followability, and kink resistance even in complicated blood vessels such as peripheral blood vessels and other peripheral blood vessels, has reliable selectivity at the blood vessel bifurcation, and is highly safe.

More specifically, in a preferred embodiment of the vascular catheter of the present invention, a base portion in which the outer diameter of the catheter body is substantially constant in the longitudinal direction, and an intermediate portion in which the outer diameter of the catheter body gradually decreases in the distal direction. In addition, since it is composed of only a flexible outer layer on the tip side from the middle part, and the tip part whose outer diameter gradually decreases toward the tip direction is formed, it has excellent pushability from the base part to the middle part. It exerts torque transmissibility, and the rigidity of the catheter body continuously decreases from almost the entire region from the middle part to the tip part, so it exhibits excellent followability to the guide wire inserted in a bent blood vessel and bends. (Kink)
Is also prevented.

In this case, since the outer diameters of the intermediate portion and the distal end portion are gradually reduced toward the distal end, the insertability (running property) when pushing the catheter into the blood vessel and the selection at the blood vessel bifurcation portion. It is highly likely.

At the boundary between the base and the middle and at the boundary between the tip and the tip, the outer surface of the catheter body forms a continuous smooth surface with no steps, thus stimulating the blood vessel. There is little damage and no damage.

Furthermore, the elastic modulus of the inner layer and the outer layer can be increased by gradually decreasing the outer diameter of the inner layer in the middle portion toward the tip direction, that is, by forming the outer surface of the inner layer in a taper shape and by selecting the material and size. With proper adjustment, sudden changes in rigidity and stress concentration at the boundary are eliminated, and kinks are less likely to occur.

Further, in a preferred embodiment of the vascular catheter of the present invention, when the outer surface of the catheter body is covered with a hydrophilic polymer substance, a surface having high lubricity is formed by connecting to a blood vessel or the like, and The operability is further improved, the inner wall of the blood vessel is not damaged, and the safety is further enhanced.

The present invention will be described below in detail with reference to the preferred examples shown in the accompanying drawings.

FIG. 1 is a plan view showing an example of the overall structure of the blood vessel catheter of the present invention, and FIG.
It is an enlarged view of the configuration of the main part of the catheter tube in the length direction of the blood vessel catheter.

As shown in FIG. 1, the blood vessel catheter 1 of the present invention comprises a catheter body 2 and a hub 12 attached to a proximal end 21 of the catheter body 2.

As shown in FIG. 2, the catheter body 2 is
A lumen 3 is formed inside from the base end 21 to the tip 22. The lumen 3 serves as a flow path for a drug solution or the like, and when the blood vessel catheter 1 is inserted into a blood vessel, the lumen 3
The guide wire is inserted into the. The hub 12 functions as an injection port for a drug solution or the like into the lumen 3 and an insertion port for the guide wire, and also as a grip portion when operating the blood vessel catheter 1.

As shown in FIG. 2, the catheter body 2 is
The main part is composed of the resin inner layer 4, and the reinforcing material layer 5 and the resin outer layer 6 which are adhered and joined to the outer surface of the resin inner layer 4. The reinforcing layer 5 is formed by forming a linear body in a lattice shape, a twisted wire shape, a spiral shape, or a knitted structure shape along the length direction of the catheter. The resin inner layer 4 is made of a material having a relatively high rigidity made of a liquid crystal polymer alloy,
The resin outer layer 6 is often made of a relatively flexible material.

Further, as shown in FIG. 1, the catheter body 2
Is composed of a base portion 7, an intermediate portion 8 and a tip portion 9 in order from the base end 21 side. Of these, the base portion 7 and the intermediate portion 8 have the multi-tube structure, and the tip portion 9 is often composed of only the resin outer layer 6.

The tip portion 9 does not have the resin inner layer 4 and the reinforcing layer 5, but is composed only of the resin outer layer 6. In this tip portion 9, it is often possible to exhibit preferable characteristics by gradually reducing the outer diameter of the catheter body 2 in the tip direction.
That is, the outer surface of the catheter body 2 forms a continuous and smooth surface (for example, a surface that curves in the catheter longitudinal direction), and it is preferable that the step is substantially eliminated. As a result, there is little irritation to the blood vessel during insertion of the catheter, damage to the inner wall of the blood vessel is prevented, and further, the boundary portion 10 is worn due to being caught when passing through the insertion port of a catheter insertion device such as a sheath. To be prevented.

In the present invention, as a constituent material of the resin inner layer 4, a resin substantially composed of a liquid crystal polymer alloy is used. The liquid crystal polymer (LCP) is a member of super-engineered plastics. Since it exhibits excellent mechanical properties particularly in the flow orientation direction, it is used as it is or in the form of alloy in various material fields. Liquid crystal polymers are roughly classified into thermotropic (heat melting type) and lyotropic (solution type), but in the present invention, thermotropic liquid crystal polymers are mainly used because of ease of molding. As such a liquid crystal polymer,
Polyarylate, polyester amide, polyester carbonate, etc. are emerging. Among them, polyarylate is typical, and it is hydroxybenzoic acid (PH
B) It is prepared by polymerizing a monomer such as 5-hydroxynaphthoic acid and a polymer such as polyethylene terephthalate alone. It is extremely complicated to describe the structure of such a liquid crystal polymer, and the following trade names are exemplified as follows.

Rodrun (Unitika), Zaider (Nippon Petrochemical), Vectra (Polyplastics), Novacurate (Mitsubishi Kasei), Econol (Sumitomo Chemical), UE
NO-LCP (Ueno Pharmaceutical), Idemitsu LCP (Idemitsu Petrochemical), Tosoh LCP (Tosoh), MGC-LCP (Mitsubishi Gas Chemicals), Toray LCP (Toray), Victorex (I
CI) etc.

These liquid crystal polymers are in the form of an alloy in which various compounding polymers and compounding agents are combined with a base polymer having a different monomer composition and structure to cover the hard and brittle properties which are the drawbacks of materials having a large amount of liquid crystal components. Often used.

The compounded polymer to be compounded with the liquid crystal polymer is, for example, polyolefin such as polypropylene, polyethylene (particularly low density polyethylene), ethylene-vinyl acetate copolymer, the above polyamide elastomer, the above polyester elastomer, polyurethane elastomer, soft Various flexible resins and elastomers such as polyvinyl chloride, polystyrene elastomer, fluorine elastomer, silicone rubber, and latex rubber can be used. Of these, polyamide elastomers, polyester elastomers, and polyolefin resins are particularly preferable. In the above description, the polyamide elastomer is, for example, nylon 6 or nylon 6
4, nylon 66, nylon 610, nylon 612,
Nylon 46, Nylon 9, Nylon 11, Nylon 1
2, various aliphatic or aromatic polyamides such as N-alkoxymethyl modified nylon, hexamethylenediamine-isophthalic acid polycondensate, and metaxyloyldiamine-adipic acid polycondensate are used as hard segments, and polyester, polyether, etc. A typical example is a block copolymer having a polymer as a soft segment. In addition, a polymer alloy (polymer blend, graft polymerization, random polymerization, etc.) of the polyamide and a resin having high flexibility, or the polyamide is softened by a plasticizer or the like. It is a concept that includes a materialized product and a mixture thereof.

The compounding agent may be an alloying agent (compatibilizer), a curing agent, a softening agent, a contrast agent, a heat and light stabilizer, a coloring agent, a surface smoothness improving agent such as a transesterification catalyst, depending on the purpose. Various additives such as an additive for the purpose of extending the molecular weight may be blended. In this case, it is preferable to use an additive component that is difficult to extract with a solvent, a drug solution, blood or the like.

In the present invention, the reinforcing material layer is composed of a reinforcing wire formed by forming a linear body along the axis of the catheter body into a lattice shape, a stranded wire shape, a spiral shape or a knitted structure.

Typical examples of the reinforcing line are shown below.

Metal wire: stainless steel, tungsten, copper,
Boron, Ni-Ti alloy, amorphous alloy, etc. Organic fibers: aramid, polyarylate, polyethylene,
Inorganic fibers such as polyvinyl alcohol: ceramic fibers, glass fibers, carbon fibers, etc. Examples of the constituent material of the resin outer layer 6 include polypropylene, polyethylene (particularly low-density polyethylene), polyolefins such as ethylene-vinyl acetate copolymer, Polyamide elastomer, the polyester elastomer, polyurethane elastomer, soft polyvinyl chloride,
Various flexible resins and elastomers such as polystyrene elastomer, fluorine-based elastomer, silicone rubber, and latex rubber can be used. Of these, polyamide elastomers, polyester elastomers, and polyolefin resins are particularly preferable.

In the above, polyamide elastomer means, for example, nylon 6, nylon 64, nylon 6
6, nylon 610, nylon 612, nylon 46,
As a hard segment, various aliphatic or aromatic polyamides such as nylon 9, nylon 11, nylon 12, N-alkoxymethyl modified nylon, hexamethylenediamine-isophthalic acid condensation polymer, and meta-xyloyldiamine-adipic acid condensation polymer are used. Block copolymers having a soft segment of a polymer such as polyester and polyether are typical, and in addition, a polymer alloy (polymer blend, graft polymerization, random polymerization, etc.) of the polyamide and a resin having high flexibility and the above This is a concept that includes a softened polyamide with a plasticizer and the like, and also a mixture thereof.

When the resin inner layer of the present invention is an alloy of a liquid crystal polymer and a (non-liquid crystal) polymer used for the resin outer layer, the resin inner layer and the resin outer layer are easily adhered to each other through the reinforcing layer, and therefore, a preferred embodiment Can be configured.

As the plasticizer, it is preferable to use one that is difficult to extract with a solvent or blood.

The polyamide elastomer, polyester elastomer, polyurethane elastomer and polyolefin resin elastomer may include alloying agents, compatibilizing agents, curing agents, softening agents, contrast agents, stabilizers, colorants, etc., if necessary. You may mix | blend various additives. In this case, it is preferable to use an additive component that is difficult to extract with a solvent, a drug solution, blood or the like.

That is, as the outer diameter Do increases, or when the outer diameter Do is constant, the outer diameter Do and the inner diameter D
The greater the difference from i, the higher the rigidity. In the case of a blood vessel catheter, the outer diameter and the inner diameter of the catheter body 2 are often regulated by the applied vascular system and procedure, and the difference between the outer diameter and the inner diameter tends to decrease empirically. It becomes low, which is disadvantageous for preventing bending. Therefore, in order to obtain necessary and sufficient rigidity, it is preferable to select the material based on the bending elastic modulus of the material.

In the present invention, the rigidity of the base portion 7 and the intermediate portion 8 mainly affects the pushability and the torque transmissibility, and most of them depend on the rigidity of the resin inner layer 4. In the catheter of the present invention, a liquid crystal polymer alloy is used to secure the rigidity of the resin inner layer 4. It is known that the liquid crystal polymer and its alloy are strongly oriented in the fluid surface layer. From this meaning, as a means of increasing the rigidity of the catheter tube of the present invention, a resin inner layer having a constant thickness is extruded and coated several times. It is possible to exhibit higher flexural elasticity (compared to the case where the total thickness is extruded and coated once) by forming in (1). In addition, it is preferable that the rate of withdrawal is 3 times or more when coating the resin inner layer, and rigidity can be increased. If it is less than 3 times, the desired rigidity cannot be obtained, and in order to obtain the desired rigidity, it is necessary to increase the rigidity by thickening the resin inner layer, and as a result, the catheter outer diameter may be increased. is there.

The withdrawal rate is obtained based on the following equation (1).

Drop rate = (Cross sectional area of resin discharge part of extrusion die) / (Cross sectional area of coating) (1) Bending elasticity (AS) of the catheter main body having the resin inner layer 4
TMD-790, 23 ° C.) is preferably 200 g or more, and more preferably 250 g or more.
If it is less than 200 g, pushability and torque transmissibility will be poor, and if it exceeds 700 g, followability with respect to the guide wire will be poor and the load on the flexible inner wall of the blood vessel will increase.

The bending ratio D of the catheter body is preferably 15 mm or less, and when it exceeds 15 mm, it is disadvantageous in that the kink resistance is deteriorated. The bending ratio D is a value measured by the device shown in FIG. 3, and holds one end 102 of the catheter main body 2 and presses the other end side along a cylindrical body 101 provided on the holding table 100 when pressing. The minimum diameter A when it can be bent 180 ° without being bent (broken line) is the bending ratio D.

In the present invention, the resin inner layer 4 and the resin outer layer 6
It is important that the outer peripheral surface of the resin inner layer 4 and the inner peripheral surface of the resin outer layer 6 and the reinforcing layer 5 interposed in the middle enhance mutual adhesion. As a specific method, for example, the resin inner layer 4 is subjected to a surface treatment for improving adhesion, a reinforcing layer is placed thereon, and then the surface treatment is similarly performed, and then the resin outer layer 6 is formed. Can be closely attached.

In the present invention, the size of the catheter body 2 is not particularly limited. For example, in the case of a blood vessel catheter used by inserting it into a blood vessel, the total length of the catheter body 2 is about 50 to 200 cm, particularly 65 to 150 cm. The length of the intermediate portion 8 is preferably about 5 to 30 cm, especially 10
About 20 cm is preferable, and the length of the tip 9 is 1 to 35 cm.
It is preferably about cm, particularly about 2 to 20 cm. In such a range, the bending rigidity of each part of the catheter body 2 is well balanced, and the above-mentioned effects are effectively exhibited.

In the present invention, the outer surface of the catheter body 2 (the outer peripheral surface of the resin outer layer 6) is preferably covered with a hydrophilic (or water-soluble) polymer substance (not shown).
As a result, when the outer surface of the catheter body 2 comes into contact with blood, physiological saline, or the like, the coefficient of friction is reduced and lubricity is imparted, and the slidability of the catheter body 2 is further improved, resulting in pushing Property, followability, kink resistance and safety are further enhanced.

Examples of the hydrophilic polymer substance include the following natural or synthetic polymer substances or derivatives thereof.

<Natural polymer substance> 1). Starch-based examples: carboxymethyl starch, dialdehyde starch 2). Cellulosic examples: CMC, MC, HEC, HPC 3). Tannin, Nignin Example: Tannin, Nignin 4). Polysaccharides Example: Alginic acid, gum arabic, guar gum, gum tragacanth, tamarind species 5). Protein example: gelatin, casein, glue, collagen <synthetic water-soluble polymer> 1). PVA-based example: polyvinyl alcohol 2). Polyethylene oxide type Example: Polyethylene oxide, polyethylene glycol 3). Acrylic acid type Example: Sodium polyacrylate 4). Maleic anhydride type Example: Methyl vinyl ether maleic anhydride copolymer 5). Phthalates: Example: Polyhydroxyethyl phthalate 6). Water-soluble polyester Example: Polydimethyl roll propionate 7). Ketone aldehyde resin Example: Methyl isopropyl ketone formaldehyde resin 8). Acrylamide Example: Polyacrylamide 9). Polyvinylpyrrolidone type Example: PVP 10). Polyamine type Example: Polyethyleneimine 11). Polyelectrolyte Example: Polystyrene sulfonate 12). Other examples: Water-soluble nylon Among these, particularly, cellulosic polymer materials (for example, hydroxypropyl cellulose), polyethylene oxide polymer materials (polyethylene glycol),
Maleic anhydride polymer (eg, maleic anhydride copolymer such as methyl vinyl ether maleic anhydride copolymer), acrylamide polymer (eg, polyacrylamide), water-soluble nylon (eg, Toray Industries) AQ-Nylon P-70) is preferable because a low coefficient of friction can be stably obtained.

Further, as the derivative of the above-mentioned polymer substance,
It is not limited to a water-soluble substance, and if the water-soluble polymer substance is used as a basic constituent, there is no particular limitation, and even if it is insolubilized, it has a degree of freedom in the branched chain and it contains water. I wish I had it.

For example, an esterified product obtained by condensation, addition, replacement, oxidation, reduction reaction or the like of the above-mentioned polymer substance,
Salt, amidated product, anhydride, halide, etherified product, hydrolyzed product, acetalized product, formalized product, alkylolated product, quaternized product, diazotized product, hydrazide compound, sulfonated product, nitrated product, ion complex: diazonium group, A substance having two or more reactive functional groups, such as an azide group, an isocyanate group, an acid chloride group, an acid anhydride group, an iminocarbonic acid ester group, an amino group, a carboxyl group, an epoxy group, a hydroxyl group, and an alkyl group, and a crosslinked product;
Examples thereof include vinyl compounds, acrylic acid, methacrylic acid, diene compounds, and copolymers with maleic anhydride.

In order to fix such a coating layer of a hydrophilic polymer substance on the outer surface of the catheter body 2, it is necessary to covalently bond it with the reactive functional group existing in or introduced into the outer layer 6 or the surface thereof. It is preferable to carry out by. This can provide a continuous lubricious surface.

The reactive functional group existing in or introduced into the outer layer 6 or on the surface thereof may be any one as long as it reacts with the above-mentioned polymer substance and crosslinks and fixes it if it does not bond. , Azido group, isocyanate group, acid chloride group, acid anhydride group, imino carbonate group, amino group, carboxyl group, epoxy group, hydroxyl group,
Examples thereof include an alkyl group and the like, and an isocyanate group, an amino group, an alkyl group and an epoxy group are particularly preferable.

The average molecular weight of the hydrophilic polymer in the present invention is not particularly limited, but is preferably about 3 to 5,000,000. As a result, a lubricating layer having high lubricity, an appropriate thickness, and an appropriate degree of swelling when containing water can be obtained.

The thickness of the lubricating layer made of such a hydrophilic polymer is not particularly limited, but is 0.1 to 100 μm.
It is preferably about 1 to 30 μm.

The composition and coating method of the hydrophilic polymer in the present invention are described in, for example, JP-A-53-10.
6778, U.S. Pat. No. 4,100,309, JP-A-63
No. 259269 and Japanese Patent Publication No. 1-33181 can be applied.

[0062]

Example 1 A specific example of the present invention will be described below.

Molding of resin inner layer Liquid crystal polyarylate which is a copolymer of parahydroxybenzoic acid and polyethylene terephthalate (Unitika Ltd.,
Rodran 3000) and an aromatic polyarylate obtained by polycondensation of terephthalic acid and bisphenol (Unitika Ltd.,
(U-polymer) 25/75 weight ratio kneaded pellets were melted by an extruder and coated on a copper wire having a diameter of 0.65 mm. The withdrawal rate was tripled.

Formation of Reinforcement Layer A reinforcement layer (stainless steel wire 30 μm: blade structure) was placed on the resin inner layer 4 using a blade machine, and a modified polyolefin having good adhesion was coated on the metal with a solution.

Molding of Resin Outer Layer On the above-mentioned copper wire / inner resin layer 4 / reinforcing layer 5
After coating the modified polyethylene, the copper wire of the inner core was removed to prepare a catheter tube having the structure shown in FIG.

Bending elasticity of catheter body tube 2 (AS
(TM D-790, 23 ° C.) was 300 g, and the bending ratio D was 10 mm. The bending ratio D is a value indicated by the diameter A when measured by the device shown in FIG.

Then, a coating layer of a methyl ethyl ether maleic anhydride copolymer, which is a hydrophilic polymer, is formed on almost the entire outer surface of the catheter body 2 by the method described in JP-B-1-33181. After formation, the hub 11 was attached to the proximal end 21 of the catheter body to obtain the angiocatheter of the present invention.

The dimensions of each part of the catheter body 2 are
It is as follows.

Total length of catheter main body: 150 cm Base length: 110 cm Base outer diameter: 1.1 mm Base inner diameter: 0.65 mm Intermediate length: 20 cm Intermediate outer diameter: Gradually reduced from 1.1 mm to 0.90 mm Intermediate inner diameter: 0 .65 mm Tip length: 20 cm Tip outer diameter: Gradually reduced from 0.90 mm to 0.74 mm Tip inner diameter: Gradually reduced from 0.65 mm to 0.54 mm

[0070]

[Example 2] The procedure of Example 1 was repeated except that the withdrawal rate was set to 5 times.

Bending elasticity of catheter body tube (AST
(MD-790, 23 ° C.) was 350 g, and the bending ratio D was 12 mm.

[0072]

Comparative Example 1 A catheter tube was prepared in exactly the same manner as in Example 1, except that the reinforcing layer was not placed. Bending elasticity of the obtained catheter body tube 2 (ASTM D-79
(0.23 ° C.) was 280 g, and the bending ratio D was 30 mm.

From this comparative example, it was confirmed that the angiocatheter of the present invention has excellent kink resistance.

[0074]

Comparative Example 2 A catheter tube was prepared in exactly the same manner as in Example 1, except that nylon was used instead of the liquid crystal polyarylate. The bending ratio D of the obtained catheter body tube 2 was 8 mm, but the bending elasticity (ASTM
D-790, 23 ° C.) was as low as 70 g.

[0075]

[Comparative Example 3] The same procedure as in Example 1 was carried out except that the withdrawal rate was 1.5 times.

Bending elasticity of catheter body tube (AST
(MD-790, 23 ° C.) was 147 g, and the bending ratio D was 9 mm.

From this comparative example, it was confirmed that the angiocatheter of the present invention is excellent in bending elasticity and has a kink resistance of a practically sufficient level.

[0078]

As described above, according to the blood vessel catheter of the present invention, since the main portion of the catheter body has the resin inner layer having high rigidity made of liquid crystal polyarylate alloy, pushability and torque transmission are improved. It is excellent, has good followability with respect to a guide wire inserted in a bent blood vessel, and has improved kink resistance and selectivity in branching blood vessels.

Further, by making the tip end flexible, the blood vessel is less stimulated, the inner wall of the blood vessel is prevented from being damaged, and the safety is high.

Further, when the outer surface of the catheter body is covered with a hydrophilic polymer substance, a lubricating surface is formed by contact with blood vessels and the like, and the frictional resistance is reduced, so that the above effect is further enhanced.

The effect of the present invention as described above is not only for ordinary arteries and veins having a relatively large diameter, but also for small diameters and many branches, such as cerebrovascular and other peripheral blood vessels, tortuous and meandering. It is also effective when selectively inserted into a blood vessel.

[0082]

[Brief description of drawings]

FIG. 1 is a plan view showing a configuration example of a blood vessel catheter of the present invention.

FIG. 2 is a vertical cross-sectional view schematically showing an enlarged configuration of the main body 2 of the catheter tube of the present invention.

FIG. 3 is a conceptual diagram for measuring a bending ratio D.

[Explanation of symbols]

 1 Vascular Catheter 2 Catheter Main Body 21 Base End 22 Tip 3 Lumen 4 Resin Inner Layer 5 Reinforcement Layer 6 Resin Outer Layer 7 Base 8 Intermediate 9 Tip 12 Hub

Claims (1)

[Claims] 1. A catheter having a portion in which a resin inner layer and a resin outer layer are joined via a reinforcing material layer, wherein the resin inner layer consists essentially of a liquid crystal polymer alloy oriented in the longitudinal direction, A catheter having a bending elasticity of 200 g or more and a bending rate of 15 mm or less.