JP2000140119A - Catheter and catheter appliance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a catheter which is excellent in operability and is more particularly excellent in kink resistance and torque transmission. SOLUTION: This catheter has a catheter body having a lumen 20. The front end 4 of the catheter body consists of metallic flat plate coils 8a and 8b which extend in the axial direction of the catheter 1, a relatively flexible outer layer 14 which is disposed on the outer side of these metallic flat plate coils 8a and 8b and extends nearer the front end side than the metallic flat plate coils 8a and 8b, a foremost end 4A which is disposed on the front end side of the front end 4 and is formed in the portion extending nearer the front end side than at least the metallic flat plate coils 8a and 8b of the outer layer 14 and an X-ray contrast member 4c which is disposed on the foremost end 4A and is arranged nearer the front end side than the metallic flat plate coils 8a and 8b.

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 ultraselective injection such as endovascular surgery, anticancer drug treatment, and angiography.

[0002]

2. Description of the Related Art In recent years, an intravascular operation for treating a vascular lesion by percutaneously inserting a catheter into a blood vessel without performing a surgical operation has become popular. In such a procedure,
The catheter has to be meandered in a complicated manner and selectively inserted into a specific site of a thin blood vessel with many branches.

For example, in endovascular surgery called embolization performed for aneurysms and arteriovenous malformations found in cerebral blood vessels and the like, the tip of a thin catheter is selectively inserted into the affected part of the brain or its vicinity. From the tip of the catheter, a liquid embolic material such as a dimethyl sulfoxide solution of cyanoacrylate or ethylene-vinyl alcohol copolymer, a granular embolic material such as polyvinyl alcohol granules, or a coil is injected. A small-diameter catheter corresponding to the injection of a liquid embolic substance, the administration of a drug, and the injection of a contrast medium into such a thin blood vessel is used.

[0004] Therefore, in addition to the chemical and biological safety required for ordinary catheters, such small-diameter catheters can be quickly and reliably inserted into small and complicated patterns of blood vessels. The required operability is required. Further, in order to inject the embolic substance, it is required to have chemical resistance, in particular, solvent resistance which does not deteriorate when it comes into contact with a solvent such as dimethyl sulfoxide.

[0005] Further, the operability of the catheter will be described in detail. The pushing force of the operator for inserting the catheter into the blood vessel can be reliably transmitted from the proximal end to the distal end of the catheter. The torque transmitting property that the rotational force applied at the proximal end side can be reliably transmitted to the distal end side, and the inside of the curved blood vessel can be smoothly advanced along the guide wire inserted beforehand without damaging the blood vessel inner wall. Followability and the catheter tip reaches the target site,
Even after the guide wire is pulled out, the kink resistance is required so that the catheter does not bend at the curved or bent portion of the blood vessel. In addition, one of the biggest factors imparting these properties to the catheter requires the lubricity of the outer surface of the catheter.

[0006] With respect to the required performance of such a catheter, as a conventional technique for imparting pushability and followability, a relatively hard inner tube and a tube which covers the outer surface of the inner tube and protrudes from the tip of the inner tube. 2. Description of the Related Art There has been developed and proposed a catheter having a double-tube structure, which is composed of a relatively flexible outer tube having a portion.

[0007] For example, in Japanese Utility Model Publication No. 60-500013, a catheter in which a polyamide is used for an inner tube and urethane is used for an outer tube, and a tip portion of the inner tube is formed in a tapered shape so that the inner diameter gradually increases. It has been disclosed. However, this catheter has poor solvent resistance because the outer tube is made of urethane, and is not suitable for a catheter used for embolization.
In addition, in the present invention, at the boundary where the double pipe portion of polyamide and urethane transitions to the single pipe portion of urethane,
Due to the rapid change in stiffness, the catheter body may be bent. In particular, in the single pipe portion of urethane, since the outer diameter and the inner diameter are constant and the rigidity does not decrease gradually toward the tip, stress concentrates at the boundary where the double pipe changes to the single pipe, and the pipe is bent. And the tracking ability is poor.

In US Pat. No. 4,636,346,
A guiding catheter having a main portion of a triple tube structure and a distal portion of a double tube structure extending distally therefrom is disclosed. In this catheter, the tube between the inner tube and the outer tube among the triple tubes of the main part is relatively rigid, but at the distal end where there is no such rigid tube, torque transmission and kink resistance are reduced. Not at the required level.

Further, Japanese Patent Application Laid-Open No. 57-173065 discloses a catheter using a spirally wound wire inside. The catheter consists of a tube that extends approximately the entire length of the tube and a spiral wound wire that terminates in the middle of the tube. However, this catheter has a spiral wound wire exposed in the catheter lumen,
Since there is a possibility that the embolic substance may be clogged or caught, and there is no possibility that the guide wire may be caught, it is necessary to carefully operate it during use.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to provide a novel catheter. That is,
It is to provide a catheter excellent in operability. In particular, it is to provide a catheter having excellent kink resistance. Another object of the present invention is to provide a catheter excellent in torque transmission. Another object of the present invention is to provide a catheter having excellent followability. Another object of the present invention is to provide a catheter having excellent pushability. Another object of the present invention is to provide a catheter having excellent chemical resistance. Another object of the present invention is to provide a catheter excellent for cerebrovascular treatment.

[0011]

SUMMARY OF THE INVENTION An object of the present invention is a catheter having a catheter body having a distal end and a proximal end, and a lumen extending between the distal end and the proximal end. A) a flat metal coil extending in the axial direction of the catheter, and b) a relatively soft outer layer or outer layer provided outside the flat metal coil and extending distally from the flat metal coil. A tube, c) a tip portion provided on the tip side of the tip portion and formed at least in a portion of the outer layer or the outer tube extending to the tip side with respect to the metal plate coil, and d) the tip portion. An X-ray contrast member provided on the distal end side of the metal plate coil.

[0012] The catheter body has a body portion on the base end side with respect to the distal end portion.
It preferably extends from the main body to the tip. Preferably, the outer layer or outer tube is formed from a relatively flexible tubular body. It is preferable that the outer layer or the outer tube is formed by covering a surface of the metal plate coil with a flexible material. Preferably, the catheter further has a relatively soft inner layer or inner tube provided inside the flat metal coil. It is preferable that the inner layer or the inner tube extends toward the distal end side from the metal plate coil to form the foremost end.
It is preferable that the catheter further has an inner layer provided inside the metal plate coil. It is preferable that the catheter main body has a main body on the base end side with respect to the distal end, and the outer diameter of the catheter decreases in the order of the main body, the distal end, and the distal end. It is preferable that a hydrophilic lubricating layer is provided on the surface of the outer layer or outer tube.

Further, the catheter of the present invention is inserted into a target blood vessel along a guide wire inserted through the lumen of the guiding catheter while projecting from a distal end of a guiding catheter having a lumen through which the catheter can be inserted. And a catheter for use with a guiding catheter and a guidewire.

The present invention also provides a catheter as described above,
A guidewire that can be inserted into the lumen of the catheter.

To explain the structure of the catheter of the present invention, it is preferable that the relatively flexible inner layer extends almost all over the catheter, but another member may be connected in the middle. For example, if the distal end of the catheter is required to be more flexible, the inner layer of the distal end may be formed of a material that is more flexible than the inner layer of the main body and connected. Furthermore, the main body is extruded in a tube shape from a hard material, and at the boundary between the main body and the tip, extrusion is continued while gradually increasing the mixing ratio of the soft material, and a portion corresponding to the tip is formed. In the case of a tube obtained by extruding only a soft material, that is, a tube formed integrally such that the main body is a hard material, the tip is a soft material, and the ratio of the soft material increases in the tip direction at the boundary at the boundary. It is also possible to use.

The inner layer has a lumen, and has a space through which a guide wire, a chemical solution, an embolizing agent, and the like can pass. The lumen diameter, that is, the inner diameter of the inner layer is preferably substantially the same from the main body to the distal end, but the inner diameter of the inner layer at the distal end can be gradually reduced in the distal direction together with the outer diameter of the outer layer at the distal end. It is. Also,
The thickness of the inner layer may be substantially the same at the tip and the main body, but it is preferable to make the tip thinner because flexibility increases.

The material of the inner layer is preferably excellent in so-called chemical resistance, which is not affected by the chemicals passing through the inside.
In particular, a catheter used for embolization is preferably provided with a solvent resistance because the embolic substance may contain a solvent such as DMSO, ethanol, or cyanoacrylate. Also, a guide wire composed of an X-ray contrast coil provided at the tip of the metal elastic core material and a fluorine-based coating material coated on the surface of the core material, and a plastic coating material coated on the surface of the metal elastic core material To improve the slidability when a guide wire such as a guide wire consisting of a hydrophilic lubricating layer fixed to the surface of the covering material is inserted into the lumen inside the inner layer, or to prevent the passage of embolic material when it is a coil. In order to facilitate the formation, it is preferable to use a smooth material having good slidability. As the material of the inner layer, a material that satisfies chemical resistance and slidability as well as flexibility is preferable,
For example, a soft fluororesin such as a fluoroelastomer, a linear low-density polyethylene (LLDPE), and a modified polyolefin can be used. In order to improve the slidability on the inner surface of the inner layer, it is preferable to perform a hydrophilic treatment. In the hydrophilic treatment, the water-swellable compound can be fixed to the inner layer directly or by a binder. In the hydrophilic treatment, a hydrophilic and hydrophobic block copolymer can be fixed to the inner layer.

The intermediate layer is composed of a rigid layer and a coil layer in the main body of the catheter, and is composed of a coil layer in the distal end. The intermediate layer is formed of a rigid layer in the main body of the catheter, and is configured such that the coil layer extends from the distal end to the distal end of the rigid layer. Further, the intermediate layer may be provided from the main body portion to the distal end portion by a coil layer having a predetermined rigidity.

The intermediate layer is provided outside the inner layer, and further provided inside the outer layer described later. Either the coil layer or the rigid layer may be inside. The intermediate layer is not necessarily required to be adhered to the inner layer or the outer layer as long as the intermediate layer has practically good torque transmission properties and pushability. However, if the front end and the base end are adhered, the torque transmission properties and pushability are improved.

The rigid layer has a relatively high rigidity, and is provided for improving the axial and lateral rigidity of the catheter and improving the pushability of transmitting the pushing force at hand to the distal end. . When a material having a corresponding rigidity is used for the inner layer and the outer layer, the rigid layer can be omitted. The thickness of the rigid layer may be substantially the same in the axial direction, and may be reduced in the distal direction at the distal end of the rigid layer.
Further, a spiral slit may be formed at the tip of the rigid layer. It is preferable that the pitch of the spiral slit be reduced in the tip direction. Further, a plurality of slits may be formed in the axial direction at the tip of the rigid layer.

The material of the rigid layer is not particularly limited as long as it improves the axial and lateral stiffness of the catheter and has a pushing property of transmitting the pushing force at hand to the tip. So polyimide,
A liquid crystal polymer or the like is used. Stainless steel (SUS3
04) may be configured as a metal layer such as a pipe or a mesh braid. Further, the outer surface of the metal coil may be covered with a braided body to suppress the degree of freedom of the coil to some extent to form a rigid layer.

The coil layer is provided for providing torque transmission and kink resistance, and further improves pushability. The coil layer extends at least from the distal end of the rigid layer to the distal end of the catheter. The coil layer may extend from the catheter body to the distal end. Since the coil layer is provided between the tip (end) and the tip of the rigid layer as described above, a drop in rigidity can be reinforced and kink can be prevented. Further, when the tip portion of the rigid layer is thinned, the kink resistance is further improved. The coil layer terminates shortly before the distal end of the catheter, preferably beyond the most flexible part of the catheter.

The coil layer is preferably a two-layer coil wound in opposite directions, but may be a single-layer coil. The coil is preferably a flat coil having a rectangular cross section, but may be a coil having a circular cross section. The winding pitch of the coil may be the same between the main body portion and the distal end portion of the catheter, but it is possible to partially change the pitch. Here, the pitch refers to the total length of the coil width (the diameter of the wire when the wire cross section is circular, the distance of the long side if the wire cross section is rectangular) and the coil gap. For example, by using a coil having a coil gap smaller than that of the tip portion or using a coil having a larger coil width, the body portion has higher rigidity. In addition, by increasing the coil gap or decreasing the coil width after passing the end of the rigid layer in the distal direction, the flexibility from the main body to the distal portion is increased stepwise or continuously in three steps and four steps. Can be changed.

In the case of a two-layer coil, it is possible to change the flexibility of the inner layer coil and the outer layer coil. Means for changing the flexibility include changing the thickness of the coil and changing the material of the coil itself. It is also possible to change the coil of the inner layer and the coil of the outer layer. Although the main body of the catheter is a two-layer coil, the inner or outer layer coil may be terminated at one end in the middle of one coil at the distal end. This provides multiple levels of flexibility. The coil used in the present invention is made of metal such as stainless steel (SUS304) or superelastic, PET,
Plastic, polyamide, and polycarbonate plastics are preferred. The outer layer is composed of a relatively flexible tubular body. Further, the outer layer may be formed by coating the surface of the inner layer or the intermediate layer with a flexible material. It also has a main body made of relatively high-rigidity resin, a tip part made of relatively low-rigidity resin, and a transition portion in which the mixing ratio of the high-rigidity resin and the low-rigidity resin changes continuously. A tube in which a part and a tip part are integrally formed may be used. Alternatively, a high-rigidity tube and a low-rigidity tube may be joined by a rigid tube therebetween. Further, a high-rigidity tube and a low-rigidity tube may be overlapped and joined over several mm to several tens of mm. In this case, the distal end of the high-rigidity tube corresponding to the main body is gradually thinned, while the low-rigidity tube corresponding to the distal end is gradually thickened and joined. This is preferable because a large area can be obtained. The outer layer may be formed by shrinking the surface of the inner layer or the intermediate layer with a shrink tube made of polyolefin or the like. The outer layer is preferably formed of a material having good biocompatibility, particularly good antithrombotic properties.

It is preferable to provide a hydrophilic lubricating layer on the surface of the outer layer. This lubricating layer may be a simple coating, but is preferably fixed to a degree that can withstand practical use. It is preferable that the surface of the outer layer be subjected to a treatment having higher biocompatibility. As biocompatibility, antithrombotic properties are required, and heparin solution coating and heparin bonding are preferred. That is, it is preferable that heparin is fixed to the outer tube surface. Further, it is preferable to form a catheter as an outer tube by mixing and extruding a thrombolytic agent with the outer tube material, since the thrombolytic agent is gradually released when the catheter is used. In addition, it is preferable to fix a block copolymer of a hydrophilic compound block and a hydrophobic compound block as a hydrophilic lubricating layer on the surface of the outer layer, because lubricity and antithrombotic properties are improved. This hydrophilic compound is preferably a water-swellable compound. As such a copolymer, block copolymer of polyglycidyl methacrylate (PGMA) -dimethylacrylamide (DMAA) is preferable.

It is preferable to provide a most flexible tip on the tip side of the tip. The foremost portion is preferably formed of two layers, an outer layer and an inner layer. However, a more flexible tip member may be fixed by fusion or bonding. Further, the foremost part can be formed by only one outer layer. Preferably, the distal end has a constriction with a reduced outer diameter. It is preferable to provide an X-ray contrast member at the forefront part. It is desirable that the X-ray contrast member be wound or embedded with a wire material of gold or platinum in a coil shape because the position of the most distal portion is found during the catheterization procedure.

Another means for preventing a sudden change in the rigidity of the catheter itself from the end of the rigid layer to the distal end thereof may be provided. That is, by providing the anti-kinking tube at the corresponding location, the effect of anti-kinking can be expected.

The cerebrovascular treatment for embolizing a cerebral aneurysm using the catheter of the present invention (cerebral aneurysm embolization) will be briefly described.

First, a guiding catheter having a lumen through which the catheter of the present invention can be inserted is inserted from the femoral artery to the internal cervix, external cervix, or vertebral artery via the aorta and placed there. The inner surface of the guiding catheter is coated with a hydrophilic coating. Next, a guide wire comprising a metal elastic core material, a plastic coating material coated on the surface thereof, and a hydrophilic lubricating layer fixed on the coating material surface, and a metal elastic core material and a guide wire provided at the tip of the core material The catheter of the present invention, in which a guide wire or the like made of an X-ray contrast-enhanced coil and a fluorine-based coating material coated on the surface of a core material is inserted and set, along the lumen of the guiding catheter, After projecting from the distal end, the catheter of the present invention and the guide wire are inserted into a target blood vessel. On the way, at the time of reaching the blood vessel bifurcation, guide the guide wire to selectively insert into the target blood vessel,
Then the catheter is pushed in. If it is difficult to insert the catheter along the guide wire, rotate the hand of the catheter, push the catheter while transmitting the rotation to the distal end of the catheter, and proceed to the target blood vessel. The cerebral aneurysm present in the target blood vessel is confirmed from the upstream side with a contrast agent from a catheter under X-ray fluoroscopy. The distal end of the catheter of the present invention has the flexibility to introduce and pass through the fine and complex blood vessels of the cerebral artery. Since the coil is provided at the distal end of the catheter even in a curved or bent blood vessel, the blood vessel can easily travel along the guide wire without kinking. Upon reaching the target site, the tip of the catheter is inserted into the cerebral aneurysm, and an embolic material such as a microcoil is introduced.
When the introduction is complete, remove the catheter.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the catheter of the present invention will be described below with reference to the drawings. FIG. 1 is an overall view of a first embodiment of the catheter of the present invention. The catheter 1 according to the present embodiment includes a catheter body 1a including a main body 2 and a distal end portion 4 and a hub 11 provided at a proximal end of the catheter main body 1a. The distal end of the distal end portion 4 has an opening 4 a and communicates from the opening 4 a to the base end 11 a of the hub 11. The guide wire 50 protrudes from the opening 4a. The catheter 1 has a total length of 1500 mm, the length of the distal end portion 4 is 200 mm, and the length of the main body 2 is 1300 mm.

FIG. 2 is a partial sectional view of the catheter 1. As shown in FIG. 2, the catheter 1 has an intermediate layer 12 including a relatively soft inner layer 6, a coil layer 8 provided outside the inner layer 6, and a rigid layer 10 having relatively high rigidity.
And a relatively soft outer layer 1 provided outside the intermediate layer 12.
The main body 2 is composed of an inner layer 6, a coil layer 8 of an intermediate layer 12, and a tip 4 composed of an outer layer 14.

A lubricating layer 16 is provided on the outer surface of the outer layer 14, and the lubricating layer 16 imparts hydrophilicity to improve slidability with blood vessels. Further, the antithrombotic property is improved by coating the lubricating layer 16 with the heparin solution.

The inner layer 6 is provided so as to extend from the main body 2 to the distal end portion 4.
To the base end 11a of the hub 11. The inner layer 6 is constituted by an inner tube and has a substantially uniform inner and outer diameter.
Guide wires, chemicals, embolic agents, etc. can pass through. Since the material of the inner layer 6 is a fluorine-based elastomer, it is excellent in chemical resistance, particularly in solvent resistance, and has good embolic material and guide wire insertion and sliding properties.

The intermediate layer 12 is composed of the rigid layer 10 and the coil layer 8 in the main body 2 of the catheter 1,
Is composed of the coil layer 8. The intermediate layer 12 is provided outside the inner layer 6, and further provided inside an outer layer 14 described later. A rigid layer 10 is provided outside the coil layer 8.
Is provided. When the intermediate layer 12 is bonded to the outer layer 14 and the inner layer 6 at the distal end and the proximal end, the pressure resistance is improved in addition to the torque transmitting property and the pushing property.

The rigid layer 10 is a tube having relatively high rigidity, and is provided for improving the rigidity of the catheter and improving the pushability of transmitting the pushing force at hand to the distal end portion 4. The thickness of the rigid layer 10 is substantially the same in the axial direction, and is reduced in the distal direction at the distal end 10a of the rigid layer. This can prevent kink. Rigid layer 1
Polyimide is used as the material of No. 0. The main body 2 provided with the rigid layer 10 has good pushability.

The coil layer 8 extends from the main body 2 to the tip 4. The coil layer 8 is provided in order to provide torque transmission and kink resistance, and further improves pushability. Since the coil layer 8 is provided between the front end (end) 10a of the rigid layer 10 and the portion beyond the end, the drop in rigidity can be reinforced and kink can be prevented. The coil layer 8 is a two-layer coil wound in mutually opposite directions.
This two-layer coil is a double coil composed of an inner coil 8a and an outer coil 8b. When the inner coil 8a is wound right, the outer coil 8b is wound left. Both the inner coil 8a and the outer coil 8b are plate coils having a substantially rectangular cross section,
The pitch is 0.12 mm for both coils, and the coil gap is 0.02 mm. The inner coil 8a and the outer coil 8b
The coils are wound in directions opposite to each other at about 80 degrees with respect to the axial direction. The thickness of both coils is about 0.01 mm. The inner coil 8a and the outer coil 8b are made of stainless steel (SUS30
4).

The outer layer 14 is composed of a relatively flexible tubular body. Since the outer layer 14 is formed by shrinking the surface of the inner layer 6 and the intermediate layer 12 with a polyolefin-based shrink tube, the outer layer 14 can be easily formed. In addition, since the swelling and bending of the coil such as the outer coil 8b are suppressed and the intermediate layer 12 can be fixed, the torque transmitting property and the pushing property are improved.

On the surface of the outer layer 14, a hydrophilic lubricating layer 16 is provided. The lubricating layer 16 is fixed to the extent that it can be put to practical use. The lubricating layer 16 is hydrated during blood vessel insertion to reduce the frictional resistance with the inner wall of the blood vessel, and can be relatively easily introduced into tortuous peripheral blood vessels. As the hydrophilic lubricating layer, although it depends on the material of the outer layer, the outer layer 14 of the present embodiment is formed of a modified polyolefin, and is a hydrophilic copolymer which is a block copolymer of polyglycidyl methacrylate (PGMA) -dimethylacrylamide (DMAA). A block copolymer of a compound block and a hydrophobic compound block is fixed. Since the hydrophilic compound of the block copolymer is a water-swellable compound, it has excellent lubricity and has a hydrophilic / hydrophobic microdomain structure, so that antithrombotic properties can be expected. On the distal end side of the distal end portion 4, a most flexible distal end portion 4A is provided.
The foremost portion 4 </ b> A is formed of two layers, the outer layer 14 and the inner layer 6. The axial length of the tip portion 4A is about 3.0 mm. The top end 4A is made of a platinum wire wound in a coil shape X
Since the line contrast member 4c is provided, the position of the distal end portion 4A of the catheter 1 can be clearly confirmed under X-ray fluoroscopy. The foremost end 4A has an opening 4a through which the lumen 20 opens.

The outer diameter of the catheter 1 is the thickest in the main body 2, the thinnest in the foremost end 4 A, and the middle in the distal end 4. For example, the outer diameter of the main body 2 is about 0.92 mm,
The outer diameter of the tip 4 is about 0.80 mm, and the outer diameter of the tip 4A is about 0.72 mm.

The second embodiment of the catheter of the present invention is basically the same as the first embodiment shown in FIG.
And a hub 11 provided at the proximal end of the catheter body 1a. Tip 4
Has an opening 4a and communicates from the opening 4a to the base end 11a of the hub 11.

FIG. 3 is a partial sectional view of a second embodiment of the catheter of the present invention. As shown in FIG. 4, the catheter 1 has a relatively flexible inner layer 6, a metal tube 30 which is a metal layer provided outside the inner layer 6, and a distal end portion 30 a of the metal tube 30.
A main body 2 composed of a coil layer 8 extending from the vicinity in the distal direction, a relatively flexible outer layer 14, an inner layer 6 extending from the main body 2, a coil layer 8, and a distal end composed of the outer layer 14 extending from the main body 2. It is composed of a part 4 and a foremost part 4A formed of two layers, an inner layer 6 and an outer layer 14 extending from the tip part 4.

The relatively soft inner layer 6 is a tubular body that forms the lumen 20 substantially throughout the catheter, and has a space through which a guide wire, a drug solution, an embolic agent, and the like can pass. The lumen diameter, i.e., the inner diameter of the inner layer, is substantially the same from the body to the tip, facilitating the passage of the insert. The material of the inner layer 6 is preferably excellent in so-called chemical resistance, which is not affected by a drug passing through the inside. Particularly, in a catheter used for embolization, a solvent such as DMSO, ethanol, or dianoacrylate is contained in the embolic substance. In some cases, it is preferable to have solvent resistance. To improve the slidability when the guide wire is inserted through the lumen inside the inner layer, or to make the embolic material easy to pass through when the coil is a coil, use a smooth material with good slidability. Since the material of the inner layer preferably satisfies chemical resistance and slidability as well as flexibility, a thin tube made of a soft fluororesin is used.

The metal tube 30, which is a metal layer, is connected to an outer layer 1 described later.
4, which is provided to improve the axial and lateral stiffness of the catheter and improve the pushability of transmitting the push force at hand to the distal end. Further, the metal tube 30 has a wide elastic range and is hardly or hardly plastically deformed in normal use against bending stress. Metal tube 30
The thickness of the metal tube 30 is substantially the same in the axial direction.
At 0a, it becomes thinner in the tip direction. Further, a spiral slit 30c is provided at the distal end portion 30a of the metal tube 30. The axial length of the spiral slit 30c is about 150 mm. Spiral slit 30
As for c, since the pitch of the slits decreases in the direction of the tip and the rigidity of the tip gradually decreases, it is effective in preventing kink. The metal tube 30 is a stainless steel (SUS304) pipe. The metal layer may be formed of a mesh braid or the like in addition to the metal tube.

The coil layer 8 is provided for providing torque transmission and kink resistance, and further improves the indentability. The coil layer 8 is provided at the tip 30 of the metal tube 30.
It extends to the distal end portion 4 of the catheter with a as a base end. Since the coil layer 8 is provided between the distal end portion (terminal end) 30a of the metal tube 30 and the portion therebefore, the drop in rigidity is reinforced and the concentration of stress can be diffused to prevent kink. During the insertion of the guidewire, the guidewire does not become unable to advance or retreat due to the kink of the catheter at the relevant position. Coil layer 8
Are two-layer coils wound in opposite directions. This two-layer coil is a double coil composed of an inner coil 8a and an outer coil 8b. Each of the inner coil 8a and the outer coil 8b is a flat coil having a rectangular cross section, the pitch of both coils is about 0.12 mm, and the coil gap is about 0.02 mm.
The coil layer 8 is a two-layer coil wound in mutually opposite directions. The inner coil 8a and the outer coil 8b are wound in directions opposite to each other at about 80 degrees with respect to the axial direction. The thickness of both coils is 0.02 mm. The inner coil 8a and the outer coil 8b are formed of stainless steel (SUS304). Note that the distal end portion 30a of the metal tube 30 and the coil layer 8
The length in the axial direction of the overlapped portion is about 2 mm. The coil layer 8 may be formed to have a thin overlapping portion so as not to form an extremely large bulge outside the catheter 1. Alternatively, the base end of the outer coil 8b may be provided at a position intermediate between the end of the metal tube 30 and the base end of the inner coil 8a by shifting the base end of the inner coil 8a. Further metal tube 30
It is preferable that the base end of the coil layer 8 starts and overlaps with about 1/3 of the entire length of the portion where the spiral slit 30c is provided.

The outer layer 14 is composed of a relatively flexible tubular body. On the surface of the outer layer 14, a hydrophilic lubricating layer 16 is provided. The lubricating layer 16 is made of a polymer capable of containing water.
Of the guiding catheter that passes through the aorta and the selection of relatively sharp vessel branches,
With the introduction of a curved or bent peripheral blood vessel or the like, rotation and pushing at hand can be freely transmitted to the distal end portion 4 with low friction.

At the distal end of the distal end portion 4 of the catheter 1, a most flexible distal end portion 4A of the entire catheter is provided. The foremost portion 4A is formed of two layers, the outer layer 14 and the inner layer 6. The foremost end 4A has an opening 4a through which the lumen 20 opens. Since the distal end portion 4A has a constricted portion 4b having a reduced outer diameter on the base end side of the opening portion 4a, the direction of the distal end portion 4A can be easily changed, and the distal end portion 4A can be inserted at a blood vessel bifurcation or an aneurysm. The range of choice of directions is expanded. An X-ray contrast member 4c in which a platinum wire is wound in a coil shape is provided at the foremost portion 4A.

FIG. 4 is a partial sectional view showing a third embodiment of the catheter of the present invention. The catheter 1 includes a main body 2 and a tip 4. An inner tube 36 integrally extending from the main body 2 to the distal end portion 4, a tube 34 having a relatively hard main body region 34 a and a relatively soft distal region 34 b, and provided between the inner tube 36 and the tube 34. And a coil 38 extending in the axial direction.

The inside of the inner tube 36 is the lumen 20, which is a passage through which a guide wire and a chemical solution pass. The diameter of the lumen 20 becomes smaller at the distal end portion 4 of the catheter 1 toward the distal end. The thickness of the inner tube 36 is substantially the same at the main body 2 and the tip 4. The inner tube 36 is made of the same material from the distal end to the proximal end, and is made of a flexible material that easily follows the curve of the inserted blood vessel and has little influence on the blood vessel.

A coil 38 is wound around the inner tube 36. The coil 38 is a stainless flat metal coil with a pitch of 0.12 mm and a coil gap of 0.02 mm. The cross-sectional shape of the flat coil is rectangular, and is about 0.01 mm in length (thickness) and about 0.1 mm in width (coil width). The coil 38 integrally extends from the main body 2 to the distal end portion 4 and terminates at a position substantially the same as the distal end of the inner tube 36. The inner diameter of the coil 38 becomes smaller toward the distal end according to the outer diameter of the inner tube 36. Coil 38
In the main body 2, the pushability is reinforced in combination with a relatively hard main body region 34a of the tube 34 described later, and the distal end portion 4 prevents torque transmission and collapse of the lumen.

The tube 34 is provided in close contact with the outside of the coil 38, and has a relatively hard body region 34a and a relatively soft tip region 34b in the axial direction. The main body region 34a and the tip region 34b are connected by a connection portion 34c. The distal end region 34b of the connecting portion 34c is fused so that the body region 34a has a tapered shape and is covered from the surface. The thickness and outer diameter of the connection portion 34c
a and the tip region 34b. The relatively hard main body region 34a corresponds to the main body 2 of the catheter 1 and provides rigidity to the main body 2 to facilitate pushing.
The relatively soft tip region 34b corresponds to the tip 4,
When a curved blood vessel or a blood vessel branched at an acute angle is inserted and placed, the guide wire is excellent in followability. Since the connecting portion 34c is overlapped and connected so that the rigidity does not suddenly change, there is little sudden change in physical properties and it is difficult to kink, but the above-mentioned coil 38 extends over the main body region 34a and the tip region 34b. Because it is provided on the inner surface,
It is even more difficult to kink. Further, by connecting tubes having intermediate flexibility between the main body region 34a and the distal end region 34b, kink is less likely to occur. Since the outer diameter of the tube 34 at the distal end portion 4 decreases toward the distal end, it is suitable for inserting a complicated and small-diameter blood vessel such as the brain.

In the main body 2, a tube 34, which is an outer tube from the outside,
Relatively hard main body region 34a, coil 3 as an intermediate layer
8 and a flexible inner tube 36 as an inner layer. At the distal end portion 4, a relatively soft distal region 34b of the tube 34, which is an outer tube from the outside, a coil 38, which is an intermediate layer,
And a flexible inner tube 36 as an inner layer.

A distal end portion 4A is adjacent to the distal end side of the distal end portion 4, and a relatively soft distal end region 3 of the tube 34 of the distal end portion 4 is provided.
4b is extended, the coil 38 ends before the distal end 4A, and the distal end of the coil 38 is adjacent to the proximal end 4b of the distal end 4A. The distal end of the inner tube 36 ends before the distal end 4A, the distal end of the coil 38 is adjacent to the proximal end 4d of the distal end 4A, and the diameter of the lumen 20 at the distal end 4A is: The lumen 2 of the adjacent inner tube 36
It is almost the same as the diameter of 0 without any step. The most advanced part 4A
An opening 4a through which the men 20 are opened is provided. Cutting edge 4A
Is embedded with a platinum coil 4c for X-ray imaging, and the position of the tip 4A can be confirmed by X-ray imaging. The distal end portion 4A may be formed in a ring shape with a relatively flexible material, and may be fused to the distal end portion 4.

FIG. 5 is a partial sectional view showing a fourth embodiment of the catheter of the present invention. The catheter 1 includes a main body 2 and a tip 4. An inner tube 46 integrally extending from the main body 2 to the distal end portion 4, a relatively hard coil 48 a and a relatively soft coil 48 b, and an outer tube 44.

The inside of the inner tube 36 is the lumen 20, which is a passage through which a guide wire, a chemical solution and the like pass. Lumen 20
Have substantially the same diameter in the main body 2 and the tip 4 of the catheter 1. The thickness of the inner tube 36 is substantially the same at the main body 2 and the tip 4. The inner tube 36 is made of the same material from the distal end to the proximal end, and is made of a flexible material that easily follows the curve of the blood vessel to be inserted and has little influence on the blood vessel.

A relatively hard coil 48a is wound around a portion corresponding to the main body 2 of the inner tube 36. The coil 48a is a flat stainless steel coil having a pitch of about 0.12 mm and a coil gap of about 0.02 mm. The cross-sectional shape of the flat coil is rectangular, and the vertical (thickness) is about 0.
01 mm and the width (coil width) is about 0.1 mm. The coil 48a is provided to provide rigidity to the main body 2, and ends in the middle of the catheter 1 and does not extend to the tip. At the tip of the coil 48a, the pitch is reduced to change the rigidity sequentially. A coil 48b is provided outside the coil 48a. Coil 48b which is an outer coil
Has lower rigidity than the coil 48a which is an inner coil. In order to change the rigidity between the coil 48a and the coil 48a, a method of making the coil material hard and soft,
A method to increase the pitch to obtain hardness, to reduce the pitch to make it softer, to increase the thickness of the coil to make it harder, to make it thinner and softer, There is also a method of forming a coil having a flexible circular cross section, and one or more of these methods can be used in combination. The winding directions of the outer coil 48b and the inner coil 48a are reversed. The coil 48b extends to the tip 4 beyond the tip of the coil 48a. Since the coil 48b of the distal end portion 4 is relatively soft, it has good followability of the guide wire and is resistant to crushing when inserting or retaining a curved blood vessel or selecting an acute blood vessel branch. The outer coil 48b is made of the same material from the distal end to the proximal end, but coils of different members may be arranged in the axial direction according to the purpose. For example, inner coil 4
The outer coil 48b is extended to the distal end 4 beyond the distal end of the inner coil 48a by making the rigidity of the outer coil 48b equal to or lower than that of the inner coil 48a in order to compensate for the easiness of kink on the distal end side of the inner coil 48a. . Outer coil 48b at tip 4
By connecting a relatively flexible coil of another member to the distal end side, the kink at the distal end of the inner coil 48a can be prevented, and the flexibility of the distal end portion 4 can be ensured. The coil 48a is provided in close contact with the inside of the coil 48b, but a relatively hard coil 48a may be provided outside the relatively soft coil 48b.

The outer tube 44 includes a coil 48a and a coil 48b.
It is fixed so that the movement of the coil does not lose its flexibility. The outer diameter of the outer tube 44 is the outer diameter of the catheter 1 together with the covering member described later, and since the thickness of the outer tube 44 is substantially the same in the axial direction, the coils 48a and 48b overlap. The part is the largest, then the part that is only coil 48b is smaller,
The foremost portion 4A described later is the smallest. The outer tube 44 is made of a relatively soft material, and its surface is coated with a water-containing polymer that imparts lubricity. Also,
The surface is coated with a coating material having antithrombotic properties.

At the tip of the tip 4, as the tip 4 A, the coil 48 b terminates shortly before and is constituted by a flexible outer tube 44 and an inner tube 46. The distal end 4A is the most flexible part of the catheter 1, reduces the risk of damaging the very delicate intima, and reduces the risk of damaging the guidewire that has been inserted into a curved or bent blood vessel. Followability also increases. A platinum coil 4c is wound around the inner tube 46 of the distal end portion 4A, and the position of the distal end portion 4a can be confirmed by X-ray contrast.

FIG. 6 is a partial sectional view showing a reference example of the catheter of the present invention. The catheter 1 includes a main body 2 and a tip 4. An inner tube 56 extending integrally from the main body 2 to the tip 4, a metal coil 58a and a braided body (blade wire)
53 and an outer tube 54.

The inside of the inner tube 36 is the lumen 20, which is a passage through which a guide wire, a chemical solution and the like pass. Lumen 20
Have substantially the same diameter in the main body 2 and the tip 4 of the catheter 1. The thickness of the inner tube 56 is substantially the same at the main body 2 and the tip 4. The inner tube 56 is made of the same material from the distal end to the proximal end, and is made of a flexible material that easily follows the curve of the inserted blood vessel and has little influence on the blood vessel.

A metal coil 58 is wound around a portion corresponding to the main body 2 of the inner tube 56. Metal coil 58
Is a stainless steel flat metal coil with a pitch of about 0.1 mm.
The coil gap is about 0.02 mm at 12 mm. The cross-sectional shape of the flat coil is rectangular and about 0.01 m long (thick)
m, width (coil width) is about 0.1 mm. Metal coil 5
Numeral 8 is provided for imparting torque transmission and kink resistance to the main body 2, and ends in the middle of the catheter 1 and does not extend to the tip.

A braided body 53 is provided outside the metal coil 58. The braid 53 extends to the tip 4 beyond the tip of the coil 58. The braided body 53 is almost the catheter 1
Are provided continuously from the distal end to the proximal end. Main unit 2
The braided body 53 has a high rigidity by suppressing the degree of freedom of the metal coil 58. The braided body 53 of the distal end portion 4 has relatively low rigidity in bending stress, and therefore has good followability of the guide wire and is resistant to crushing when inserting or placing a curved blood vessel or selecting an acute blood vessel branch. . The outer tube 54 is a braided body 5
3 and a metal coil 58, and the coil is fixed in close contact with the coil so as not to lose its flexibility. Outer tube 5
4 together with the covering member described later,
And the thickness of the outer tube 54 is substantially the same in the axial direction, so that the main body portion 2 where the braid 53 and the coil 58 overlap is the largest, and then the braid 53 and the inner tube 5
6, the distal end portion 4 which becomes the outer tube 54 is smaller, and the foremost end portion 4A described later is the smallest. The outer tube 54 is made of a relatively soft material, and its surface is coated with a water-containing polymer that imparts lubricity. In addition, the surface is coated with a coating material having antithrombotic properties.

At the forefront of the distal end portion 4, the braided body 53 terminates on the front side as a foremost portion 4 A, and includes a flexible outer tube 54 and an inner tube 56. Advanced part 4
A is the most flexible part of catheter 1 and reduces the risk of damaging the very delicate intima of the blood vessel, and also follows the guide wire inserted into a curved or bent blood vessel. Get higher. A platinum coil 4c is wound around the inner tube 56 of the distal end portion 4A, and the position of the distal end portion 4a can be confirmed by X-ray contrast.

[0063]

As described in detail above, the catheter of the present invention comprises a catheter body having a distal end and a proximal end, and a lumen extending between the distal end and the proximal end. The distal end of the body has a) a flat metal coil extending in the axial direction of the catheter; and b) a relatively soft outer layer or a layer provided outside the flat metal coil and extending distally from the flat metal coil. An outer tube, c) a foremost portion provided at a tip side of the tip portion and formed at least in a portion of the outer layer or the outer tube extending to the tip side with respect to the metal plate coil, and d) the foremost portion Provided in
It is characterized by having an X-ray contrast member disposed on the distal end side from the metal plate coil, so that it is excellent in operability, particularly in kink resistance and torque transmission. Furthermore, since the pushability and chemical resistance are improved, the operability is good in cerebrovascular treatment.

[Brief description of the drawings]

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

FIG. 2 is a partial sectional view of a first embodiment of the catheter of the present invention.

FIG. 3 is a partial cross-sectional view of a second embodiment of the catheter of the present invention.

FIG. 4 is a partial sectional view of a third embodiment of the catheter of the present invention.

FIG. 5 is a partial sectional view of a fourth embodiment of the catheter of the present invention.

FIG. 6 is a partial sectional view of a reference example of the catheter of the present invention.

[Explanation of symbols]

 1: catheter 2: body 4: tip 6: inner layer 8: coil layer 10: rigid layer 12: intermediate layer 14: outer layer

Claims (10)

[Claims] A catheter body having a distal end and a proximal end;
A catheter comprising a lumen extending between the distal end and the proximal end, the distal end of the catheter body comprising: a) a metal plate coil extending in an axial direction of the catheter; b) an outside of the metal plate coil. A) a relatively flexible outer layer or outer tube extending to the distal end side of the metal plate coil, and c) provided at the distal end side of the distal end portion, at least from the metal plate coil of the outer layer or outer tube. And d) an X-ray contrast member provided at the foremost portion and disposed on the forefront side of the metal plate coil. Characterized catheter. 2. The catheter body according to claim 1, wherein the catheter main body has a main body on a base end side with respect to the distal end, and the metal plate coil extends from the main body to the distal end. The catheter as described. 3. The catheter according to claim 1, wherein the outer layer or the outer tube is formed of a relatively flexible tubular body. 4. The catheter according to claim 1, wherein the outer layer or the outer tube is formed by coating a flexible material. 5. The catheter according to claim 1, wherein the catheter further has a relatively flexible inner layer or inner tube provided inside the metal plate coil. 6. The catheter according to claim 5, wherein the inner layer or the inner tube extends more distally than the metal plate coil to form the distal end. 7. The catheter main body has a main body on the proximal side from the distal end, and the outer diameter of the catheter is smaller in the order of the main body, the distal end, and the distal end. A catheter according to any one of claims 1 to 6. 8. The catheter according to claim 1, wherein a hydrophilic lubricating layer is provided on a surface of the outer layer or the outer tube. 9. The catheter may be inserted into a target blood vessel along a guide wire inserted through the lumen of the guiding catheter while projecting from a distal end of a guiding catheter having a lumen through which the catheter can be inserted. The catheter according to any one of claims 1 to 8, which is a catheter used together with a guiding catheter and a guide wire. 10. A catheter device comprising the catheter according to claim 1, and a guide wire that can be inserted into the lumen of the catheter.