JPH0663142A - Pipe and catheter for diagnosis and treatment - Google Patents

Abstract

PURPOSE:To provide a pipe and a catheter for diagnosis and treatment which can satisfy the respective needs for characteristics such as flexibility, buckling resistance, pushability and torque transmissibility. CONSTITUTION:A metal wire rod 5 which has a polyester resin layer 12 coated on the outer surface thereof and is formed by low-carbon two phase organization steel with the tensile strength of 300Kgf/mm or more is coiled so that adjacent coil parts 5a, 5b form a pipe 6 pressed to each other by the initial restoring force of coiled forming. A fluororesin layer 22 is coated on the inner peripheral surface or the outer peripheral surface by heat contraction or by pressure at the time of injection molding to closely adhere to the polyester resin layer to be taken as a catheter for diagnosis and treatment.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible material that can be easily bent into a free shape, a buckling resistance that prevents the cross-sectional shape from being crushed when bent, and a pushability that easily advances by a pressing force. Pipes required to transmit torque with high accuracy, such as diagnostic and therapeutic pipes, optical communication pipes, and industrial piping materials, and particularly the flexibility and buckling resistance required for the pipes. , The structure of the pipe which can improve the characteristics such as pushability and torque transmissibility and contribute to the reduction of the diameter. INDUSTRIAL APPLICABILITY The present invention is most suitable for a diagnostic and therapeutic catheter that is inserted into the heart, brain, lungs, stomach, or these blood vessels to extract body fluids, blood, etc., or inject drugs. explain.

[0002]

2. Description of the Related Art In recent years, a method of diagnosing and treating the inside of the heart and coronary arteries by inserting a catheter into a blood vessel has attracted attention. This is because a catheter is inserted into a coronary artery from an artery such as the femoral region, a contrast agent is administered from the distal end of the catheter, and this is fluoroscopically diagnosed, and a catheter is used in patients with ischemic heart disease. The coronary artery is dilated and treated. This treatment method has been attracting attention as a new treatment method for ischemic heart disease because it can correct coronary stenosis without opening the chest and immediately improve clinical symptoms. The following characteristics are required for such a catheter. The outer diameter should be as thin as possible to prevent bleeding when inserting into or removing from a thin blood vessel. On the other hand, the inner diameter should be as large as possible in order to inject and administer a large amount of contrast agent against blood pressure. For that purpose, at least 0.75 mmφ is required. In addition, since it is necessary to insert it along the twisted and bent blood vessel, it has excellent flexibility to bend freely,
Also, it has excellent buckling resistance so that the cross-sectional shape does not collapse when it is bent. When pushing inside the blood vessel, it has excellent pushability that surely advances in the pushing direction. In addition, in order to freely change the direction of the distal end of the catheter, the torque transmission property that can reliably transmit the rotation amount by the rotating operation at hand to the distal end of the catheter is required. In addition, it must be pressure resistant in order to maintain a stable internal pressure when administering a contrast agent. Conventionally, as a catheter requiring the above characteristics, for example, a reinforcing layer is formed on the outer surface of an inner cylinder made of fluororesin or the like, and a resin outer cover for improving pressure resistance is inserted on the surface of the reinforcing layer. There is a structure (for example, Japanese Patent Application Sho
63-161937). The reinforcing layer is formed by twisting a plurality of metal ultrafine wires into a knitting structure of warp and weft yarns, wound around the inner cylinder, or the outer surface of the inner cylinder is provided with a fine wire core. It is constructed by winding it in a spiral of 45 degrees.

[0003]

However, the above-mentioned conventional catheter has a structure in which the inner cylinder is reinforced with a reinforcing layer in order to secure the above-mentioned characteristics such as buckling resistance, and moreover, the reinforcing layers are numerous. Since it has a structure in which the ultrafine wires are braided, or the ultrafine wires are wound while being inclined with respect to the axis, the wall thickness of the pipe is likely to be increased accordingly. As a result, the outer diameter of the conventional catheter is limited to 3.5 mmφ when the above-mentioned predetermined inner diameter is secured, and improvement in this respect is required. Further, the above-mentioned conventional catheter has a problem that if the diameter is too small, torque transmission and buckling resistance are insufficient, transmission of the rotational operation amount to the distal end is not sufficient, and the cross-sectional shape of the catheter is easily collapsed. is there.

The present invention has been made in view of the above-mentioned conventional circumstances, and provides a pipe and a diagnostic / treatment catheter having a completely new structure which can further reduce the outer diameter while satisfying all the above-mentioned characteristics. It is an object.

[0005]

According to a first aspect of the present invention, a metal wire is wound in a coil shape, and adjacent coil portions of the metal wire are in pressure contact with each other by an initial restoring force by coil forming. It is a pipe characterized by that. The invention according to claim 2 is a diagnostic treatment catheter using the pipe according to claim 1, wherein the outer surface of the metal wire is coated with a polyester resin layer, and the inner peripheral surface or the outer peripheral surface of the pipe is formed. It is characterized in that the fluororesin layer is formed so as to adhere to the polyester resin layer by heat shrinkage or by pressure during injection molding. Further, the invention of claim 3 is a pipe and a catheter for diagnostic treatment, wherein the metal wire is a piano wire, a stainless wire, or a low carbon dual phase steel wire having a tensile strength of 300 Kgf / mm ² or more. is there.

Here, the initial restoring force in the present invention means the restoring force in a state where no external force is applied. When the adjacent coil portions are in pressure contact, as shown in FIG. 1, the pitch p between the coil portions 5a, 5a is equal to the wire diameter d, and a tensile load of a predetermined value or more is applied in the axial direction. Up to the above, it means a state where the pitch p remains d and does not change. Further, as a method of pressing the coil portions to each other, for example, a metal wire is wound around a core rod,
Alternatively, when a coil is formed by bending with a roller, the coil portions are formed so that the pitch p between them is smaller than the wire diameter d, that is, the coil portions are formed so as to overlap each other in the axial direction. This can be achieved by allowing the coil portion to retain a force for returning to a pitch state smaller than the above d in the natural state after processing. The metal wire may have a circular cross section, an elliptical cross section, or a rectangular cross section, and is not particularly limited.
Further, the pipe of the present invention may be a double-wound metal wire.

The coating of the above-mentioned metal wire material with the polyester resin can prevent metal elution and has a film thickness of 1 to 1.
This is because it can be coated in a thin thickness of 5 μm and the chemical resistance can be improved. In addition, the fluororesin is adhered to the polyester resin layer by heat shrinkage or pressure during injection molding on the pipe, so that the gap between adjacent coil portions on the surface of the pipe is eliminated to improve torque transmission and sterilization. This is because of the improvement, and the film thickness of this fluororesin layer is preferably 20 to 50 μm. The fluororesin layer may be coated on both the inner peripheral surface and the outer peripheral surface of the pipe, or may be coated on only one of them.

Furthermore, the metal wire may be a piano wire,
The reason why the stainless wire or the low carbon dual phase steel wire is adopted is that it contributes to the downsizing of the pipe while satisfying the respective characteristics required when it is used as a diagnostic / treatment catheter, for example. Here, the low carbon dual phase steel wire is
This was previously proposed by the applicant of the present invention, in which C: 0.01 to 0.50% by weight, Si: 3.0% or less, Mn: 5.0% or less, and the balance of Fe and unavoidable impurities is 3.0 to 6.
It was manufactured by subjecting a 0-mm wire rod to a primary heat treatment, a primary cold drawing, a secondary heat treatment, and a secondary cold drawing to obtain a wire having a diameter of 120 μm or less. Incidentally, such a manufacturing method is described in JP-A-62-20824. A metal ultrafine wire made of a low carbon dual phase steel wire produced by the above method,
The processing cell by the above-mentioned strong processing has a fibrous fine metal structure arranged in a fiber shape in one direction, and the size of the processing cell, the fiber interval is 5 to 100 Å, 50 to 1000 Å,
Furthermore, the tensile strength is 300 to 600 kg / mm ² or more. When such a low carbon dual phase steel wire is used as the metal wire, the tensile strength and the toughness can be improved while making the wire diameter smaller than the piano wire and the stainless wire. When the low carbon dual phase steel wire or piano wire is adopted, it is desirable to coat the surface with Ni plating. By forming a Ni plating coating layer, the adhesion with the resin coating layer can be improved.
In addition, for example, it is possible to suppress the activity of the wire when using a metal ultrafine wire with a wire diameter of 120 μm or less,
Also, the corrosion resistance can be improved.

[0009]

According to the pipe of the first aspect of the present invention, the metal wire is wound in a coil shape, and the coil portions are pressed against each other by the initial restoring force of the coil forming. By adopting it as a diagnostic / treatment catheter, it is possible to achieve a reduction in diameter while ensuring the above-mentioned characteristics. That is, since the pipe can be formed only by the metal wire rod, the wall thickness can be made smaller than that of the conventional structure in which the inner cylinder is reinforced with the reinforcing layer made of the knitting structure.
By adopting a metal ultra-fine wire of about 100 μm, it is possible to reduce the outer diameter to about 1 mmφ while maintaining an inner diameter of 0.75 mmφ or more, which has been difficult in the past, and to meet the above-mentioned demand for smaller diameter. . Further, the pipe of the present invention has a structure in which circularly shaped coil portions are in pressure contact with each other, has high flexibility, and is easily bent into a free shape. On the other hand, since the circular shape holding force of the coil portion itself is extremely strong, the circular shape is not crushed even when it is flexibly bent as described above, and the buckling resistance is significantly improved. Moreover, since the coil parts are pressed against each other,
The rotary operation amount applied to one end of the pipe is surely transmitted to the tip portion as it is, and the torque transmissibility is improved. Also, since the coil parts are in pressure contact with each other, the pushing force applied to one end of the pipe is transmitted to the tip without being absorbed, and when this is used as a catheter, it is pushed to insert and push it into the blood vessel. The ability can be secured.

Further, in the invention of claim 2, since the polyester resin layer is formed on the outer surface of the metal wire and the fluorine resin layer is formed on the surface of the pipe by heat shrinkage or injection molding, the polyester resin layer is formed. It is possible to prevent metal elution, and to coat thinly, to improve chemical resistance, and to eliminate gaps between adjacent coil portions by the fluororesin layer, thereby improving torque transmission and sterilization. Furthermore, the pressure resistance of the pipe can be improved, and the resistance when the contrast agent is injected can be reduced by the fluororesin layer on the inner surface.

Further, according to the invention of claim 3, since the piano wire, the stainless wire or the low carbon dual phase steel wire is adopted as the metal wire material, the tensile strength at the time of forming a small diameter pipe by the extra fine wire The thickness can be reduced while securing. In this case, especially when low-carbon dual-phase steel wire is used, it is possible to easily obtain a wire with a tensile strength of 300 to 600 kg / mm ² and a wire diameter of 100 μm or less, and to have a higher strength than the piano wire. And can contribute to the reduction in diameter.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 5 are views for explaining a pipe according to an embodiment of the invention of claim 1, and in this embodiment, the case of application to a diagnostic / treatment catheter will be described as an example.
In the figure, reference numeral 1 is a diagnostic treatment catheter to which the pipe of this embodiment is applied, which is connected to an operating portion 3 having a contrast agent injection portion at one end of an insertion portion 2 having a length of about 1 m and an outer diameter of about 1 mm. The guide portion 4 is fixed and rotatably fitted. The insertion portion 2 is bent in a generally V shape, and a pore 2a for ejecting a contrast agent is formed at the tip of the insertion portion 2.

The insertion portion 2 is formed by winding a metal wire 5 having a wire diameter of about 100 μm into a coil to form a pipe 6, and the outer surface of the pipe 6 is covered with a resin coating layer 7 having a thickness of 1 to 2 μm. It was formed. The resin coating layer 7 has a wave shape along the outer surface of the pipe 6, and the wave shape is adjusted by appropriately selecting the viscosity of the resin liquid and the like. The metal wire 5 is made of a low carbon dual phase steel wire, has the above-mentioned composition, and is manufactured by the above-mentioned manufacturing method. This low-carbon dual-phase steel wire has a fibrous fine metal structure in which working cells produced by strong working are arranged in one direction in a fibrous form, and the size of the working cells and the fiber spacing are each 5 ~ 100Å, 50 ~ 1000Å, and tensile strength is 300 ~ 600 kg / mm ² . A Ni plating layer 8 of about 1 μm is formed on the surface of the metal wire 5. The plating layer 8 has a processing strain due to the plastic working during the wire drawing work, so that the adhesion with the resin coating layer 7 is improved.

In the pipe 6, the adjacent coil portions 5a, 5a of the metal wire rod 5 are in pressure contact with each other by the initial restoring force by coil forming (see FIG. 1 → mark), whereby the pipe 6 with no gap is formed. Are formed. The initial restoring force is such that, when the metal wire 5 is wound around a core rod or is formed into a coil by bending with a roller, adjacent coil portions are axially overlapped with each other. It is obtained by winding so that the coil pitch p becomes smaller than the wire diameter d.

Next, the function and effect of this embodiment will be described. In the catheter 1 of the present embodiment, for example, the insertion portion 2 is inserted into the coronary artery of the heart from an artery such as the femoral region, the contrast agent is administered through the pores 2a of the insertion portion 2, and this is fluoroscopically observed. To diagnose abnormalities. And the catheter 1 of this embodiment
According to this, since the metal wire 5 is wound into a coil to form the pipe 6 and the coil portions 5a of the metal wire 5 are pressed against each other by the initial restoring force, the following characteristics can be improved. can get. I. Since the basic shape of the insertion portion 2 is constituted only by the metal wire 5 and the thin resin coating layer 7 is provided on the basic shape, compared with the conventional structure in which the inner cylinder is reinforced by the reinforcing layer made of the knitting structure. The wall thickness can be reduced. As a result, the outer diameter can be significantly reduced while ensuring the pressure resistance and inner diameter necessary for administering the contrast agent, and the insertion into a thin blood vessel can be performed smoothly, and bleeding during extraction can be prevented. Can be suppressed. Further, since the low-carbon dual-phase steel wire is adopted as the metal wire 5, the tensile strength of the wire itself can be improved, and the wire diameter can be made extremely small to 100 μm or less, which also contributes to the reduction in diameter. . II. Further, since the pipe 6 is formed by pressing the coil portions 5a of the metal wire 5 into contact with each other, the pipe 6 itself has extremely high flexibility and therefore can be easily inserted into a twisted and bent blood vessel. it can. on the other hand,
The circular shape retaining force of the coil portion 5a itself is extremely strong, and therefore the circular shape is not crushed even though it has the flexibility, and the buckling resistance is significantly improved. III. Further, since the coil portions 5a are in pressure contact with each other and the circular shape retaining force is strong, the rotational operation amount applied to one end of the catheter 1 is directly transmitted to the distal end portion, and torque transmissibility is improved. Also, the pushing force applied to one end is transmitted to the tip as it is, improving the pushability,
The insertion portion 2 of the catheter 1 can be surely oriented in a desired direction and can be advanced in the pushed direction, so that a desired examination site can be inserted.

FIG. 6 shows a modification of the above embodiment. In the pipe 10 of the present embodiment, a ribbon-shaped metal wire rod 11 having a thickness of 10 to 30 μm and a width of 50 to 150 μm and a rectangular cross section is wound in a coil shape, and the coil portions 11a of the metal wire rod 11 are initially restored. This is an example in which they are pressed against each other by force. With this pipe 10, the same effect as that of the above-described embodiment can be obtained, and the outer diameter can be further reduced while ensuring the required inner diameter.

Further, in the above embodiment, one metal wire 5 is used.
Although the case where the pipe 6 is formed by the above is described as an example, the present invention is not limited to the pipe 6 as shown by the chain double-dashed line in FIG.
The metal wire 5 may be doubly wound around the outer peripheral surface of, and in such a case, the buckling property, the torque transmissibility and the like can be further improved. Further, in the above embodiment, the case where the pipe is applied to the catheter has been described as an example, but the pipe of the present invention is not limited to this, for example, a pipe for inserting an optical fiber, a suction pipe, or for precision machinery. It can also be applied to pipes and the like, and is particularly effective when applied to pipes that require flexibility, buckling resistance, torque transmission properties, and the like.

FIG. 7 and FIG. 8 are views for explaining the diagnostic and therapeutic catheter according to the second aspect of the present invention.
The same reference numerals as those in FIG. 1 indicate the same or corresponding parts. The diagnostic / treatment catheter 20 of the present embodiment has a metal wire rod 5 formed by coating a Ni plating layer 8 on the outer surface of a low carbon dual phase steel wire, and the adjacent coil portions 5a, 5a of the metal wire rod 5. Of the pipes 6 are in pressure contact with each other, and the basic structure is the same as that of the above embodiment.

The outer surface of the metal wire 5 is coated with a polyester resin layer 21 having a thickness of about 1 to 5 μm, and the outer surface of the pipe 6 has a thickness of 20 to 20 μm.
A fluororesin layer 22 made of Teflon (registered trademark) having a thickness of about 50 μm is formed by coating. This fluororesin layer 22
As shown in FIG. 8, the pipe 6 is formed by inserting the pipe 6 into the fluorinated resin tube 22 'and heating the tube 22' to about 350.degree. As a result, the space between the coil portions 5a, 5a of the pipe 6 is filled with the fluororesin layer 22 and there is no gap.
Moreover, the fluorine resin layer 22 is the polyester resin layer 21.
Is in close contact with. An injection molding method can also be used as a method of forming the fluororesin layer 22. The pressure at the time of this injection molding causes the fluororesin to fill the gaps between the coil portions and adhere to the polyester resin layer.

According to the present embodiment, the coil portions 5a of the metal wire rod 5 are pressed against each other by the initial restoring force to make the pipe 6
Since this is formed, the same effects as the respective characteristics of the above-described embodiment can be obtained. Further, since the polyester resin layer 21 is formed on the outer surface of the metal wire 5, thin coating can be easily performed, metal elution can be prevented, and chemical resistance can be improved. Furthermore, since the Ni plating layer 8 is formed on the surface of the low carbon dual phase steel wire and the polyester resin layer 21 is formed on the surface of the plating layer 8, the adhesion and the adhesiveness of the resin layer 8 are improved. The effect that it can be obtained is also obtained. Furthermore, since the fluororesin layer 22 is formed on the outer surface of the pipe 6 while heat-shrinking, the gap between the pipe 6 and the fluororesin layer 22 can be surely eliminated, and torque transmission and sterilization are prevented. Can be improved. This is because the conventional catheter for diagnosis and treatment has a structure in which the reinforcing layer is simply inserted into the resin tube, so that a gap a is likely to occur between the resin tube and the reinforcing layer as shown in FIG. 8, for example. As a result, there is a problem that the torque transmissibility is poor and it is difficult to sterilize the gap a. Although the fluororesin layer 22 is formed only on the outer surface of the pipe 6 in the above embodiment,
This may be formed only on the inner surface or on both sides, and when formed on both sides, the above respective characteristics can be further improved.

[0021]

As described above, according to the pipe of the first aspect of the present invention, the metal wire is wound in a coil shape, and the coil portions of the metal wire are coil-formed by the initial restoring force of the wire itself. Since they are pressed against each other, there is an effect that they can contribute to a reduction in diameter while improving flexibility, buckling resistance, torque transferability, and the like. Further, in the invention of claim 2, since the polyester resin layer is formed on the outer surface of the metal wire and the fluorine resin layer is formed on the inner peripheral surface or the outer peripheral surface of the pipe, the polyester resin layer is thinly coated. On the other hand, there is an effect that the chemical resistance can be improved, and a torque transmission property and a sterilization property can be improved by eliminating the gap between the adjacent coil portions by the fluororesin layer. Further, according to the invention of claim 3, since the piano wire, the stainless wire or the low carbon dual phase steel wire is used as the metal wire material, the thickness can be reduced while securing the necessary strength, and the diameter can be further reduced. There is an effect that can be done.

[Brief description of drawings]

FIG. 1 is a partial sectional side view for explaining a pipe according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the pipe of the above embodiment.

FIG. 3 is a cross-sectional view of the metal wire rod of the above embodiment.

FIG. 4 is a perspective view showing a pipe of the above embodiment.

FIG. 5 is a perspective view showing a diagnostic / treatment catheter to which the pipe of the above embodiment is applied.

FIG. 6 is a side view showing a modified example of the pipe of the above embodiment.

FIG. 7 is a partial cross-sectional side view for explaining a diagnostic treatment catheter according to an embodiment of the present invention.

FIG. 8 is a side view showing a method of forming a fluororesin layer on the surface of the pipe of the above embodiment.

[Explanation of symbols]

 5, 11 Metal wire 5a, 11a Coil part 6, 10 Pipe 20 Diagnostic and therapeutic catheter 21 Polyester resin layer 22 Fluorine resin layer

Claims (3)

[Claims] 1. A pipe characterized in that a metal wire is wound in a coil shape, and adjacent coil portions of the metal wire are in pressure contact with each other by an initial restoring force due to coil forming. 2. A pipe formed by winding a metal wire rod whose outer surface is coated with a polyester resin layer into a coil shape, and winding such that adjacent coil portions of the metal wire rod are in pressure contact with each other by an initial restoring force by coiling. And a fluororesin layer on the inner or outer peripheral surface of the pipe by heat shrinkage,
Alternatively, the catheter for diagnosis and treatment is characterized in that it is formed so as to be in close contact with the polyester resin layer by the pressure during injection molding. 3. The metal wire according to claim 1, wherein the metal wire is a piano wire, a stainless wire, or a tensile strength of 300 Kgf.
A pipe and a diagnostic / treatment catheter characterized by comprising a low-carbon dual-phase steel wire of / mm ² or more.