JPH10244007A - Chateter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a catheter which is excellent in manipulatability, and which has an anti-kink ability, which has a proximal end part appropriate for cutting, and a distal end part easy to form herein a side hole. SOLUTION: A catheter is composed of a flexible tube body 2 formed of an outer layer 6, an inner layer 7 and an intermediate structure 8 between them, which are laminated one upon another. The tube body 2 has a distal end part 21, an intermediate part 22 and a proximal end part 23, arranged in the mentioned order in the longitudinal direction thereof. The distal end part 21 is composed of an outer layer 6, having side holes 3. The intermediate part 22 is composed of the outer layer 5, an inner layer 7 and an intermediate structure 8. The distal end part 23 is composed of the outer layer 6 and the inner layer 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a catheter, and more particularly to an indwelling catheter.

[0002]

2. Description of the Related Art Epidural catheters are used for epidural anesthesia, and indwelling catheters for hepatic arteries are used for treatment of liver cancer and the like. Such a catheter is required to have excellent operability so that it can be inserted into the epidural space or vascular system of a thin and complicated shape with a quick and reliable selectivity. In addition, kink resistance is required so that the catheter does not bend at a curved or bent portion such as an epidural space.

[0003] That is, a so-called push-in property, in which a force pushed by an operator to penetrate a blood vessel, can be reliably transmitted from the proximal end to the distal end of the catheter, and a rotational force applied at the proximal end of the catheter has a distal end. It is required to have a torque transmitting property that can be reliably transmitted to the part and a followability that can smoothly move through a bent portion without damaging a living tissue.

In order to obtain the above-mentioned pushability, torque transmission and kink resistance, a portion other than the distal end of the catheter is made of a relatively hard material. For this purpose, it is preferable that the distal end of the catheter is made of a relatively flexible material.

For example, Japanese Utility Model Publication No. Sho 62-17082 discloses a catheter comprising an outer tube and an inner tube. This catheter has a double tube structure in which silicon rubber is used for the outer tube, hard resin such as fluorine resin is used for the inner tube, and the inner tube is inserted into a portion of the outer tube other than the tip. But,
In this catheter, a step corresponding to the thickness of the inner tube is formed in the lumen of the tube at the boundary between the single tube portion (tip portion) and the double tube portion (portion excluding the tip portion). Therefore, bending is likely to occur at the step, and the kink resistance is poor.

In US Pat. No. 4,636,346,
A guiding catheter having a main portion of a triple tube structure composed of an inner tube, an intermediate layer, and an outer tube, and a distal end portion of a double tube structure (lacking the intermediate layer of the main portion) extended in a distal direction therefrom is provided. It has been disclosed.

By the way, in the case of an indwelling catheter such as an epidural catheter, for example, a proximal portion is cut to an appropriate length according to the case and used.

However, in the catheter disclosed in US Pat. No. 4,636,346, since the metal coil is disposed almost entirely except for the distal end portion as the intermediate layer, cutting is difficult. The cross-sectional shape is deformed,
There is a problem that the catheter is not suitable for cutting because it causes collapse of the lumen of the catheter. Therefore, various catheters having different lengths must be prepared in advance, and the most suitable catheter must be selected and used.

Further, when a side hole is provided at the distal end of the double tube structure for this catheter, the physical and chemical properties (for example, melting points) of the material of the outer tube and the material of the inner tube are different, so that precision is required. However, there is a problem that it is difficult to form a proper side hole.

[0010]

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide excellent operability and kink resistance, to be easily cut at an arbitrary portion of a base end, and to be provided at a front end. An object of the present invention is to provide a catheter in which a hole is easily formed.

[0011]

This and other objects are achieved by the present invention which is defined below as (1) to (19).

(1) In a catheter having a flexible tube main body in which an outer layer, an inner layer, and an intermediate structure located therebetween are laminated, the tube main body is constituted by the outer layer or the inner layer. And a distal end portion having at least one side hole, an intermediate portion composed of the outer layer, the intermediate structure, and the inner layer, and a proximal end portion configured of at least one of the outer layer or the inner layer. A catheter characterized by the above-mentioned.

(2) In a catheter having a flexible tube main body in which an outer layer, an inner layer and an intermediate structure located therebetween are laminated, the tube main body is constituted by the outer layer or the inner layer. And a distal end having at least one side hole, an intermediate part composed of the outer layer, the intermediate structure, and the inner layer, and a proximal end composed of the outer layer and the inner layer. And catheter.

(3) The catheter according to (1) or (2), wherein the distal end of the distal end is closed.

(4) The catheter according to any one of (1) to (3), wherein the distal end has a lower rigidity than the intermediate portion.

(5) The catheter according to any one of (1) to (4), wherein the distal end portion is formed of the outer layer.

(6) The base according to any one of the above (1) to (5), wherein the base end can be cut at an arbitrary position and a connecting member is connected to the cut end. The catheter as described.

(7) The catheter according to any one of (1) to (6), wherein the outer layer and the inner layer are made of different polymer materials.

(8) The catheter according to any one of (1) to (7), wherein the outer layer is made of a material having a lower melting point than the inner layer.

(9) The catheter according to any one of (1) to (8) above, wherein the hardness of the inner layer is higher than the hardness of the outer layer.

(10) The outer layer has a Shore hardness D ₁ ,
The catheter according to any one of the above (1) to (9), wherein the Shore hardness D _{2 of the} inner layer satisfies the following formulas (I), (II) and (III). D ₁ ≦ 65 (I) D ₂ ≧ 50 (II) D ₁ <D ₂ (III)

(11) The catheter according to any one of (1) to (10), wherein the inner layer has a smaller thickness than the outer layer.

(12) The catheter according to any one of (1) to (11), wherein the outer layer is formed of a urethane resin, and the inner layer is formed of a fluorine resin.

(13) The catheter according to any one of (1) to (12), wherein the intermediate structure is made of a metal material.

(14) The catheter according to any one of (1) to (12), wherein the intermediate structure is a metal coil.

(15) The catheter according to any one of (1) to (14), wherein the side hole is formed by laser processing.

(16) The catheter according to any one of (1) to (14), wherein the side hole is formed by laser processing using an excimer laser.

(17) The catheter according to (16), wherein the excimer laser has an oscillation wavelength of 248 nm.

(18) The catheter according to any one of (1) to (17), wherein the diameter of the side hole is smaller than the inner diameter of the tube body.

(19) The catheter according to any one of (1) to (18) above, wherein the tube main body is used by being inserted and placed in an epidural space.

[0031]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a catheter according to the present invention will be described in detail based on a preferred embodiment shown in the accompanying drawings.

FIG. 1 is an overall schematic view of the catheter of the present invention, FIG. 2 is a partial longitudinal sectional view of the tube body of the catheter shown in FIG. 1, and FIG. 3 is a sectional view taken along line AA in FIG. 4
Is a sectional view taken along line BB in FIG. 2, and FIG. 5 is a sectional view taken along line CC in FIG.
FIG. 6 is a schematic view showing a state in which the catheter of the present invention is inserted and placed in the epidural space. Note that the right side in FIG. 2 is described as a “base end” and the left side as a “distal end”.

A catheter 1 of the present invention shown in FIG. 1 is a catheter for epidural space used by being inserted and detained in an epidural space, and is mainly connected to a tube main body 2 and a proximal end thereof. And a subcutaneous implantation port 4 which is used as a subcutaneous implantation port.

The tube body 2 has a lumen 20,
The distal end portion 21 is provided with a side hole 3 for injecting a drug solution into an epidural space or the like. Further, the base end side of the tube main body 2 is cut at an arbitrary position, and then the cut end surface is connected to the connection portion 41 such as the normal embedding port 4.

The catheter body 2 has a distal end 2 in the longitudinal direction.
1, an intermediate part 22, a base end part 23, and an inner layer 7,
The intermediate structure 8 and the outer layer 6 are laminated, and the tip 2
1, the intermediate portion 22 and the base end portion 23 are composed of at least one of the inner layer 7, the intermediate structure 8, and the outer layer 6.

Hereinafter, the catheter body 2 will be described by dividing it in the longitudinal direction. The distal end portion 21 of the tube main body 2 has a single-pipe structure constituted by the outer layer 6, as shown in FIGS. This makes it easier to provide side holes. That is, for example, in the case of a double-pipe structure made of different resins, when a side hole is opened using a heated jig, the jig is heated in accordance with the material having a higher melting point, so that the jig is heated at a lower melting point. There is a problem that the resin is deteriorated (deteriorated) or decomposed (liquefied) due to the high temperature of the jig. In addition, when forming side holes by laser processing, it is necessary to select laser light according to the absorption characteristics of each material in order to form the side holes with high accuracy, such as differences in the absorptivity of laser light in each material. In consideration of the above, it is necessary to control the irradiation time, irradiation energy and the like of the laser beam for each material, and the manufacturing process becomes complicated. On the other hand, when side holes are provided by irradiating a high energy laser, so-called burrs or the like are generated around the holes due to excessive melting of the resin. For this reason, the side holes 3 cannot be formed with high accuracy.

However, in the case of a single-pipe structure as in the present invention, the processing conditions for the side holes can be determined in accordance with the characteristics of one type of material forming the end portion 21. And the accuracy of the shape and dimensions can be increased.

The material of the outer layer 6 is a flexible material so as not to damage a living tissue when inserted into a living body. Examples include polyvinyl chloride resins,
Urethane resins such as polyurethane, olefin resins such as polyethylene, polypropylene, ethylene-vinyl acetate copolymer, polyester, polyether, polyamide resin, tetrafluoroethylene / perfluoroalkylvinyl ether copolymer (PFA), polytetra Examples include various synthetic resins such as fluoroethylene such as fluoroethylene (PTFE) and fluoroelastomer; various thermoplastic elastomers such as polyamide elastomer and polyester elastomer; and polymer materials such as various rubbers. Among them, a thermoplastic resin material having flexibility is preferable, for example, polyolefin such as polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, polyester, polyvinyl chloride, urethane resin, polyamide , Polyamide elastomer, silicone rubber and the like are preferable, and urethane resin is particularly preferable. Since the urethane-based resin is relatively soft, it has a high effect of protecting a living tissue when the distal end portion 21 is inserted. Also,
It is also preferable from the viewpoint of adhesiveness with a fluororesin constituting the inner layer 7 described later and biocompatibility.

The length of the tip 21 is not particularly limited,
For example, 2 to 100 mm is preferable, and 5 to 30 mm is particularly preferable. If the distal end portion 21 is too short, it becomes difficult to form the side hole 3, while if it is too long, a kink or the like occurs at the time of insertion due to its flexibility, and the lumen 20 may be narrowed or closed.

In the case of an epidural catheter, the outer diameter of the outer layer 6 constituting the distal end portion 21 is, for example, 0.6 to 1.5.
mm, preferably 0.8 to 1.2 mm. The inner diameter is, for example, preferably from 0.3 to 0.9 mm, particularly preferably from 0.4 to 0.6 mm. In the case of a vascular catheter, the outer diameter is preferably, for example, 0.8 to 2.5 mm, and the inner diameter is, for example, preferably 0.3 to 2.0 mm. By setting the inside diameter and the outside diameter in these ranges, flexibility and followability to bending are sufficiently exhibited.

The tip 21 is filled with a drug solution (for example, an anesthetic, an anticancer drug, physiological saline, etc.) in the epidural space (target site).
At least one side hole 3 for injecting into the hole is provided. When a plurality of side holes 3 are provided, it is preferable that the side holes 3 are arranged so as to be shifted from each other in the longitudinal direction and / or the outer peripheral direction of the tube main body 2. In the case of this embodiment, two side holes 3 are displaced in the longitudinal direction and the outer peripheral direction of the tube body 2 respectively. This prevents breakage due to a decrease in the strength of the distal end portion 21, increases the flow rate of the chemical solution, and improves the dispersibility of the chemical solution.

The diameter of the side hole 3 is not particularly limited, but is preferably smaller than the inner diameter of the tube body 2, for example.
If the hole diameter is too small, an excessive pressure is applied to the inner wall of the distal end portion 21 when sending the chemical solution, which is not preferable. If the hole diameter is too large, the strength of the tube body 2 is reduced. The side holes 3 may have different hole diameters.

The side holes 3 are preferably formed by laser processing in view of the easiness of formation, the shape and the dimensional accuracy, and an excimer laser is particularly preferable.

An excimer laser is a laser that oscillates a short pulse with a high peak power in the ultraviolet region.
r, Kr, Xe, etc.) and halogen (F, Cl, Br, etc.)
Oscillates, for example, at a wavelength of 193 to 351 nm. When such an excimer laser is irradiated on a polymer material, it is possible to instantaneously form fine side holes in the tube main body 2 using a phenomenon in which the material can be subjected to a vaporization process without heat influence, that is, a so-called ablation phenomenon. it can. Therefore, the small-diameter side hole 3 can be easily formed with a high dimensional accuracy without causing processing defects such as alteration, melting, burrs, and soot.

In consideration of the constituent materials of the catheter body 2, among the excimer lasers, particularly, the wavelength is 248.
nm or less, and a KrF excimer laser having an oscillation wavelength of 248 nm is particularly preferable. A laser having such a wavelength is particularly excellent in workability.

The tip 211 of the tip 21 is not particularly limited, but is preferably closed as shown in FIG. If the distal end 211 is provided with a hole, when inserting the tube body 2, foreign matter such as minute blood vessels or fat in the epidural space 12 enters through the hole of the distal end 211, and the lumen 2.
This is because 0 may be clogged.

The tip 211 is preferably rounded as shown in FIG. 2 so as not to damage the living tissue when inserted into the living body.

In the illustrated example, the distal end portion 21 is formed of one layer of the outer layer 6, but may be formed of only one layer of the inner layer 7 described later instead. Also in this case 1
Since it is a layer, the same operation and effect as described above can be obtained.

The intermediate portion 22 has relatively high rigidity, and the distal end portion 21 has a lower rigidity than the intermediate portion 22. The intermediate portion 22 has a triple tube structure including the outer layer 6, the intermediate structure 8, and the inner layer 7, as shown in FIGS.

By adopting such a triple tube structure,
The intermediate portion 22 of the tube body 2 has an appropriate bending elasticity,
As shown in FIG. 6, it is possible to cope with a sharp bend of the tube at the time of being inserted and placed in the epidural space 12, and the kink does not cause collapse of the lumen 20 even in insertion into a curved blood vessel.

As shown in FIGS. 2 and 4, the intermediate structure 8 is provided between the outer layer 6 described above and an inner layer 7 described later.

This intermediate structure 8 is, as shown in FIG.
When the epidural catheter is inserted and placed, the tube body 2
Covers the part with the largest curvature.

The intermediate structure 8 functions as a so-called reinforcing material layer. For example, any shape such as a tubular shape, a coil shape, and a mesh may be used, but a coil as shown in FIG. 2 is preferable. Thus, the kink resistance and torque transmission of the intermediate portion 22 can be improved with a relatively small thickness, and the pushability of transmitting the pushing force at the base end portion 23 to the distal end portion 21 can be improved. . Further, the coil can be freely set in terms of the winding pitch, the number of windings, and the like, and the adjustment of the rigidity and the like of the intermediate portion 22 becomes easy.

The sectional shape of the coil is preferably flat as shown in FIG. Thereby, the intermediate structure 8 can be made thinner while securing a sufficient reinforcing effect.

Examples of the material constituting the intermediate structure 8 include various metal materials such as stainless steel, aluminum or aluminum alloy, superelastic alloy, shape memory alloy, polyamide, polyvinyl chloride, polycarbonate, ABS resin, polyethylene, polypropylene,
Various synthetic resin materials such as polytetrafluoroethylene, acrylic resin, polyetherketone (PEK), polyetheretherketone (PEEK), and polyimide can be used. Metal materials are preferable, and stainless steel (SUS
304) is particularly preferred. The intermediate structure 8 is provided relatively thin (for example, about 30 μm) as described later.
Stainless steel is preferable because it can exhibit kink resistance at such a thickness and can prevent the lumen 20 from being closed. And
It is easy to process because of its excellent ductility and malleability.

The reason why the intermediate structure 8 is provided between the outer layer 6 and the inner layer 7 is to prevent the intermediate structure 8 from being exposed on the inner surface and the outer surface of the tube body 2. For example,
When the intermediate structure 8 is made of a metal material, it is the tube body 2
If it is exposed on the inner surface or outer surface of the substrate, it comes into contact with a chemical solution or a body fluid for a long time, which may cause problems such as corrosion of a metal material and elution of metal ions.

The intermediate structure 8 constituting the intermediate portion 22
The thickness of the layer is not particularly limited, for example, 0.01 to
0.1 mm, and more preferably 0.03 to 0.05 mm. If the layer of the intermediate structure 8 is too thin, a sufficient reinforcing effect,
That is, elasticity, bending rigidity, and kink resistance cannot be exhibited. If one layer is too thick, it may be exposed on the inner surface and the outer surface, and the tube main body 2 is excessively hard, which is not preferable.

As shown in FIG. 2, the inner layer 7 is provided over the intermediate portion 22 except for the distal end portion 21 and the proximal end portion 23 of the catheter main body 2. Thereby, the intermediate portion 22 forms a triple tube structure as shown in FIG. 4, and has higher bending elasticity and rigidity than the tip portion 21 of the single tube structure composed of the outer layer 6, thereby improving the kink resistance. Further, the inner layer 7 functions to prevent the intermediate structure 8 from coming into contact with the chemical solution passing through the lumen 20 as described above.

As the material of the inner layer 7, the same polymer material as that of the outer layer 6 can be used, but a resin having a higher melting point than the material of the outer layer 6 and a relatively hard resin is preferable. Thereby, the rigidity of the intermediate portion 22 and the base end portion 23 is maintained, and sufficient kink resistance is obtained. Further, by fusing the outer layer 6 having a low melting point to the outer peripheral surface of the inner layer 7, the coating can be formed easily and with good yield.

Although such a material is not particularly limited, for example, a fluorine-based resin is exemplified, and polytetrafluoroethylene (PTFE) is particularly preferred. Since polytetrafluoroethylene is a relatively hard resin, the inner layer 7
Can be provided with kink resistance even if the layer is formed thin.
Further, such a material is excellent in chemical resistance and has a low coefficient of friction, so that the fluidity of a chemical solution or the like can be improved.

Further, PTFE has good slipperiness, and is excellent in ease of pulling out when removing a core wire used for molding a catheter after molding, which is preferable in production.

The hardness of the inner layer 7 is preferably larger than the hardness of the outer layer 6, and in particular, the Shore hardness D of the outer layer 6
_1, when the Shore hardness D ₂ of the inner layer 7, the following formula (I), it is preferable to satisfy the relationship (II) and (III).

D ₁ ≦ 65 (I)

D ₂ ≧ 50 (II)

D ₁ <D ₂ (III)

By satisfying the above relationship, the catheter body can exhibit sufficient kink resistance and flexibility of the distal end portion 21 even if the catheter is a very thin catheter for epidural space. The combination of the outer layer 6 and the inner layer 7 that satisfies such a relationship is not particularly limited, but the most preferable examples include, for example, the above-mentioned outer layer 6 made of a polyurethane resin and the inner layer 7 made of a fluororesin.

Although the length of the intermediate portion 22 is not particularly limited,
In the case of an epidural catheter, for example, it is preferably from 30 to 500 mm, more preferably from 100 to 200 mm. In the case of a vascular catheter, for example, it is preferably 50 to 850 mm. If the intermediate portion 22 is too short, the portion exhibiting sufficient kink resistance will be shortened accordingly, and the range of response to various cases will be narrowed, and versatility will be reduced. On the other hand, if the length of the intermediate portion 22 is too long, there is a possibility that the cut portion may enter the region of the intermediate portion 22 when the catheter is adjusted to a desired length. May be difficult to cut.

The thickness of the inner layer 7 is preferably 0.01 to 0.1 mm, more preferably 0.03 to 0.05 mm. If the thickness is too small, when the tube body 2 is bent,
The inner layer 7 may be easily damaged such as cracks, and the intermediate structure 8 may be exposed on the inner wall surface of the tube body 2.
On the other hand, if it is too large, the tube main body 2 becomes hard and the kink resistance cannot be effectively exhibited, and the outer diameter of the tube main body 2 itself becomes undesirably large.

The thickness of the inner layer 7 is preferably smaller than that of the outer layer 6. If the thickness of the inner layer 7 is larger than that of the outer layer 6, the tube main body 2 becomes hard, so that kink resistance may not be sufficiently exhibited.

A portion having a double tube structure (stiffness difference absorbing portion) composed of the outer layer 6 and the inner layer 7 may be provided at the boundary between the tip portion 21 and the intermediate portion 22. Thus, the difference in rigidity between the distal end portion 21 and the intermediate portion 22 can be reduced, and kink due to a change in rigidity can be effectively prevented.

Further, the intermediate structure 8 is moved from the tip of the intermediate portion 22 to the intermediate structure 8.
Is also preferred to prevent exposure to the inner wall surface and direct contact with the chemical solution.

The inner layer 7 and the intermediate structure 8 are joined to each other. The bonding method in this case is not particularly limited, and includes, for example, bonding with an adhesive.

The base end 23 is located at the middle 2 of the tube body 2.
It is located closer to the proximal end than 2. As shown in FIGS. 2 and 5, the base end portion 23 preferably has a double-tube structure including the inner layer 7 and the outer layer 6. With the double tube structure of the inner layer 7 and the outer layer 6, appropriate bending rigidity and kink resistance are imparted to the entire base end portion 23.

The base structure 23 is not provided with the intermediate structure 8. This facilitates the cutting of the base end 22 at an arbitrary position. That is, as described above, since the intermediate structure 8 is made of a material such as a relatively hard metal, it is difficult to cut with scissors or the like, and even if cut, the shape of the cut end face of the tube body 2 is deformed by plastic deformation. As a result, it is difficult to insert the connection portion 41 such as an embedded port, and the connection becomes difficult. In addition, if the connection is made in a deformed state, the connection will be incomplete and detachment from the connection portion 41, liquid leakage, and the like are likely to occur.

On the other hand, when the outer layer 6 and the inner layer 7 are composed of only the resin layer as in the present invention, even if they are cut off with scissors or the like, the cut portion has a sectional shape due to the elasticity of the resin itself. Is restored to its original circular shape and does not plastically deform. Therefore, connection to the connection portion 41 can be easily and reliably performed regardless of the cutting position.

Although the length of the base portion 23 is not particularly limited,
In the case of an epidural catheter, it is preferably 30 to 92%, more preferably 60 to 85%, based on the entire length of the catheter body 2. In the case of a vascular catheter, it is not particularly limited, but preferably 5 to 75%.

The absolute length of the base portion 23 is preferably at least 30 mm, more preferably at least 50 mm.

The base portion 23 may be constituted by either the outer layer 6 or the inner layer 7.

As a method of manufacturing the catheter of the present invention as described above, for example, first, the inner layer 7 is formed on the core wire (covering of the electric wire). Subsequently, the intermediate structure 8 is arranged on the outer peripheral surface of the inner layer 7 and bonded.

Next, the outer layer 6 separately formed by hollow molding is put on the outer peripheral surfaces of the inner layer 7 and the intermediate structure 8 and joined by, for example, wire covering molding. Thus, the intermediate structure 8 is provided between the outer peripheral surface of the inner layer 7 and the inner peripheral surface of the outer layer 6.

Bonding by wire coating molding is preferable in terms of simplification of the process, high dimensional accuracy, and assurance of surface smoothness. Other bonding methods include, for example, fusion by heating and adhesive bonding. Bonding, solvent welding, or the like may be used.

Subsequently, after removing the core wire, the tip 2
Cut 1 to appropriate length. Next, the tip portion 21 is subjected to tip processing. That is, first, the lumen 2 of the tube body 2
The core wire is inserted into the mold 0, and in this state, the tip 211 is inserted into a mold such as a mold, a glass mold, or a synthetic resin heated by a high-frequency induction heating or a heater. Thereby, the constituent material of the distal end portion 21 is melted, and the distal end 211 is closed in a rounded shape.

Next, a predetermined number of side holes 3 are formed at predetermined positions of the distal end portion 21 by laser processing using the above-described excimer laser or the like, and the catheter body 2 is completed.

The embodiments of the catheter according to the present invention have been described with reference to the drawings. However, the present invention is not limited to these embodiments. Particularly, constituent materials of the outer layer 6, the inner layer 7, and the intermediate structure 8,
Any combination of characteristics such as rigidity and hardness is possible.

The catheter of the present invention may not include the subcutaneous implantation port 4 or may be connected to the tube body 2 by a member other than the subcutaneous implantation port, such as a connector, a hub, or a branch tube. Any member may be used.

The structure of the catheter of the present invention may have an arbitrary layer between each of the inner layer 7, the intermediate structure 8, and the outer layer 6. For example, a hydrophilic polymer layer may be formed on the outer side of the outer layer to obtain wet lubricity.
Further, with respect to the longitudinal direction of the catheter, an arbitrary portion may be provided between the distal end portion 21 and the intermediate portion 22, between the intermediate portion 22 and the proximal end portion 23, or further on the proximal end side of the proximal end portion 23. You may.

The use of the catheter of the present invention is not limited to epidural catheters, but may be other catheters such as IVH, PTCA, IABP, cardiac output measurement, arterial infusion, TAE, The present invention is also applicable to catheters for cancer chemotherapy and the like, and particularly to various catheters that may be used by cutting the base end side.

[0088]

Next, specific examples of the present invention will be described.

Example 1 An epidural catheter shown in FIGS. 1 to 5 was prepared. The conditions of this catheter are as follows.

Total length of catheter = 950 mm Length of distal end portion 21 = 15 mm Length of intermediate portion 22 = 100 mm Length of proximal end portion = 835 mm (88% of total catheter length)
%)

[0091]

<Intermediate structure 8> Constituent material: Stainless steel SUS304 Form: One-layer single-turn coil with a flat cross-section line having a thickness of 50 μm Outer diameter: 0.7 mm Inner diameter: 0.6 mm Total length: 100 mm

[0093]

<Side holes> Number of formed: 2 Formed position: 5 mm from the tip, 10 mm (opposite sides) Hole diameter: 300 μm (within ± 10% error with respect to design value) Forming method: KrF excimer laser (oscillation wavelength: 248 nm) Laser processing Energy: 32mJ, Irradiation time: 11 ± 1sec / 1 hole

[Experiment 1] Implantation The catheter prepared in Example 1 was inserted into the epidural space of an experimental animal according to a conventional method.

At the same time, a subcutaneous pocket was created under the collarbone of the experimental animal, and a subcutaneous implantation port was fixed therein.

Next, in order to make the proximal end of the catheter suitable length, about 150 mm from the proximal end was cut with scissors, and the cut end was inserted into the connection of the subcutaneous implantation port and connected. .

At this time, there was no deformation such as crushing of the cut end surface of the catheter, and the connection operation could be performed easily, quickly and reliably.

Finally, the inside of the subcutaneous pocket in which the port was placed was washed, and after confirming hemostasis, the suture was sutured to complete the port implantation. As a result, the catheter was inserted and placed in the epidural space.

2. Injection of chemical solution A nonionic X-ray contrast agent (iohexol, concentration: iodine content 240 mg / ml, 5 ml) was prepared and injected from the port using a syringe.

3. X-ray observation Assuming the injection of a drug solution, an X-ray contrast agent was injected for visualization.

Under X-ray fluoroscopy, the movement of the injected contrast agent in the catheter and the outflow from the side hole of the catheter were observed.

As a result, the contrast agent flowed smoothly in the catheter, and was injected into the epidural space from both side holes at the distal end. This confirmed that the catheter of Example 1 did not suffer from inconvenience such as stenosis or occlusion of the lumen due to kink.

In addition, there was no detachment between the catheter and the connection portion of the port, and no leakage of the contrast agent was observed at that portion.

[0105]

As described above, according to the catheter of the present invention, excellent kink resistance is exhibited while maintaining performance such as torque transmission, pushability, and followability, and safety is improved. high.

In addition, since the proximal end is suitable for cutting, the catheter can be cut at an arbitrary position on the proximal end and the length of the catheter can be adjusted.

In particular, since there is no deformation of the cut end surface, the connection can be easily and reliably made when connecting to a connection portion such as an embedding port, and leakage of a chemical solution or the like at the connection portion does not occur.

Further, since the tip portion is made of the same material, the formation of the side hole is facilitated, and the accuracy of the shape and size of the side hole is high.

[Brief description of the drawings]

FIG. 1 is an overall schematic view of a catheter of the present invention.

FIG. 2 is a partial longitudinal sectional view of the catheter shown in FIG.

FIG. 3 is a sectional view taken along line AA in FIG. 2;

FIG. 4 is a sectional view taken along line BB in FIG. 2;

FIG. 5 is a sectional view taken along line CC in FIG. 2;

FIG. 6 is a schematic diagram showing a state where the catheter of the present invention is inserted and placed in an epidural space.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Catheter 2 Tube main body 3 Side hole 4 Subcutaneous implantation port 6 Outer layer 7 Inner layer 8 Intermediate structure 12 Epidural space 20 Lumen 21 Tip section 22 Intermediate section 23 Base section 41 Connection section 211 Tip

Claims (19)

[Claims] 1. A catheter having a flexible tube main body formed by laminating an outer layer, an inner layer, and an intermediate structure located therebetween, wherein the tube main body includes the outer layer or the inner layer, And at least one
A tip portion having two side holes, an intermediate portion configured by the outer layer, the intermediate structure, and the inner layer, and a base end configured by at least one of the outer layer and the inner layer. Catheter. 2. A catheter comprising a flexible tube main body formed by laminating an outer layer, an inner layer, and an intermediate structure located therebetween, wherein the tube main body is constituted by the outer layer or the inner layer, And at least one
A catheter comprising: a distal end having two side holes; an intermediate portion including the outer layer, the intermediate structure, and the inner layer; and a proximal end including the outer layer and the inner layer. 3. The catheter according to claim 1, wherein the distal end of the distal end is closed. 4. The catheter according to claim 1, wherein the distal end has a lower rigidity than the intermediate portion. 5. The catheter according to claim 1, wherein the distal end is formed of the outer layer. 6. The catheter according to any one of claims 1 to 5, wherein the base end can be cut at any position, and is used by connecting a connection member to the cut end. 7. The catheter according to claim 1, wherein the outer layer and the inner layer are made of different polymer materials. 8. The catheter according to claim 1, wherein the outer layer is made of a material having a lower melting point than the inner layer. 9. The catheter according to claim 1, wherein the hardness of the inner layer is higher than the hardness of the outer layer. 10. The catheter according to claim ₁ , wherein the Shore hardness D _{1 of the} outer layer and the Shore hardness D _{2 of the} inner layer satisfy the following formulas (I), (II) and (III). . D ₁ ≦ 65 (I) D ₂ ≧ 50 (II) D ₁ <D ₂ (III) 11. The catheter according to claim 1, wherein the inner layer has a smaller thickness than the outer layer. 12. The method according to claim 1, wherein the outer layer is made of a urethane resin, and the inner layer is made of a fluorine resin.
12. The catheter according to any one of items 11 to 11. 13. The catheter according to claim 1, wherein the intermediate structure is made of a metal material. 14. The catheter according to claim 1, wherein the intermediate structure is a metal coil. 15. The catheter according to claim 1, wherein the side hole is formed by laser processing. 16. The catheter according to claim 1, wherein the side hole is formed by laser processing using an excimer laser. 17. The catheter according to claim 16, wherein the excimer laser has an oscillation wavelength of 248 nm. 18. The catheter according to claim 1, wherein a diameter of the side hole is smaller than an inner diameter of the tube main body. 19. The catheter according to claim 1, wherein the tube main body is used by being inserted and placed in an epidural space.