JPH1033682A - Catheter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the feedability of angiographic agent and insertability of guide wire, improve the blood vessel insertability by miniaturization of outer diameter, and improve the basic performance as medical catheter by forming an inner layer tube from a tube body formed of a resin tape wound with overlap. SOLUTION: In a catheter 1, an inner layer tube 2 has a structure in which a resin tape is wound with overlap into a tube body, and an outer layer tube 3 prepared by resin extrusion molding is provided on the circumference of the inner layer tube 2. Namely, a resin tape 10 is wound with overlap on a core metal 12 of slender wire rod having an appropriate wire diameter so that the side edges are superposed by a slight quantity, whereby a wound body 13 having a lap part 8 having a preset lap width L is formed, and the wound body 13 is removed from the metal core 12 to form the inner layer tube 2 of independent tube body. Then, after a metallic braid 4 is wound on the circumference, the outer layer tube 3 prepared by resin extrusion molding is formed on the circumference by posterior attaching followed by cutting to form the catheter 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a medical catheter which is inserted into a coronary artery of a patient and used as a guide such as a contrast catheter or a balloon catheter.

[0002]

2. Description of the Related Art A medical catheter 1 is a Japanese patent publication 7-21.
There are known examples such as Japanese Patent Publication No. 84 and Japanese Patent Application Laid-Open No. Hei 7-8563, etc. (see FIG. 5 (A)), which consist of a multi-layer tube wall in which an inner tube 2 and an outer tube 3 for inserting a guide wire into a center hole are laminated. It has the basic shape of a flexible microtubule, guides the catheter 1 from the distal end into the patient's blood vessel, and grasps (sometimes while rotating) the proximal end portion of the patient coming out of the patient's blood vessel into the meandering blood vessel. It is configured to perform a predetermined treatment by inserting and setting it.

[0003] Therefore, for the intravascular insertion set, a high degree of mechanical properties such as appropriate elasticity, vertical load resistance (buckling resistance) against insertion resistance load in the advancing direction, and torsional rigidity are required. The distal end portion leading in the blood vessel needs to have a high degree of flexibility and flexibility, and the proximal end portion that goes out of the body needs a steering property to be inserted and advanced into the blood vessel by manual operation. The vertical load and the torsional rigidity are not uniform in the longitudinal direction of the tube, but preferably increase gradually in the proximal direction.

[0004] As described above, the catheter 1 having the conventional structure (see FIG. 5 (B)) is obtained by winding the metal braid 4 around the outer circumference of the inner layer tube 2 and mechanical properties of the metal braid 4 as a mechanical element. Or the resin properties of the inner tube 2 and the outer tube 3 are hardly and softly combined, or the thickness of the inner tube 2 and the outer tube 3 of the hard / soft combination resin is adjusted, or the like. Consideration has been given to bring it closer to that of the nature.

[0005]

Since the conventional catheter 1 having the above structure is a resin tube, it is continuously molded by a known resin extrusion molding method, so that the tube has an uneven wall thickness. In some cases, such uneven wall thickness impairs the mechanical properties of the pipe, so the pipe wall is set to be slightly thicker (with the intention of stabilizing the mechanical properties of the pipe and preventing the effect of uneven wall thickness). I have to make the meat thicker)
There is a problem that the outer diameter of the catheter 1 is increased and the insertability in the blood vessel is deteriorated.
In order to stabilize the adhesiveness of the inner tube 2 and function as a resin tube body in which the inner tube 2 and the outer tube 3 are integrated, the outer surface of the inner tube 2 extruded in advance is roughened by mechanical means or chemical means. It is necessary to perform the processing, and the catheter 1 is complicated in the forming process, which increases the cost.

Since the conventional catheter is an extruded resin tube, the vertical load and torsional stiffness in the longitudinal direction of the tube except for the distal end portion must be uniform. If the rigidity of the base end portion is not appropriate for the properties and the rigidity of the base end portion is set to an appropriate value, the flexibility of the intermediate portion of the tube will be insufficient, and if the flexibility of the intermediate portion of the tube is set to an appropriate value, the rigidity of the base end portion will be insufficient. However, there is a drawback in that a weak zone having mechanical properties is present in any part of the catheter, thereby impairing the intravascular insertion property.

On the other hand, in the case of a structure in which the metal braid 4 is wound (see FIGS. 5B and 5C), the metal braid 4 knitted to be long and wide is cut into a predetermined size, and the metal braid 4 is cut into a predetermined size. After welding the tips of the wires 5 of the cut portion to each other, the inner pipe 2
Wrapped around. However, the end of the metal braid 4 wound around the inner tube 2 has a qualitative shape in which the end portion of the metal braid 4 bulges outward due to release of the braid constraint by cutting and welding stress. Therefore, the outer tube 3 at that portion expands to hinder the uniformity of the outer diameter, and at the same time, the wire 5
May protrude from the outer periphery of the outer layer tube 3, and in such a state, the insertability into the blood vessel is reduced, and further, the blood vessel wall is damaged.

Therefore, in order to prevent the safety hindrance or the like due to the protrusion of the wire 5 beforehand, the outer periphery of the outer tube 3 where the end of the metal braid 4 is located is magnified with a magnifying glass. The manual inspection must be carefully performed for the presence / absence of lines. However, the inspection work is a micro-inspection for confirming a very small protrusion of a round wire having a diameter of approximately 0.075 mm diameter (or a square wire having a thickness of 0.03 mm and a width of 0.15 mm width). In addition to requiring a lot of inspection man-hours,
There is a possibility that a projecting portion may be erroneously recognized as a "good product having no protruding line", and lacks quality reliability.

The present invention provides a catheter which overcomes the above-mentioned drawbacks of the prior art.

[0010]

A catheter according to the present invention which solves the above technical problem is a catheter comprising a flexible ultrafine inner tube through which a guide wire is inserted into a central hole, wherein the inner tube is formed of a resin tape. It is characterized in that it is a laminated tube in which an outer tube and an outer layer are provided on the outer periphery of an inner tube, and is used in the same manner as a catheter having a conventional structure. The term “overlap winding” in the present invention means a normal overlap winding in which, when a tape is wound around a rod or the like in a spiral shape, the edges of the tape are slightly overlapped and wound.

The inner tube having the tape-overlap winding structure is formed by, for example, a method in which a resin tape is overlap-wrapped around a core bar, and then the core bar is removed. A mode in which mechanical properties such as rigidity and flexibility in the longitudinal direction of the inner layer tube are intentionally adjusted and set by changing the amount by gradually increasing / decreasing or changing the amount of netting on the outer surface of the tape of the resin tape. Alternatively, an embodiment using a two-layer resin tape to which a punching tape is adhered has been adopted, and an outer layer portion in which a resin tape is also overlapped and wound around the inner layer tube is provided, and the outer layer tube is formed by a conventional resin extrusion molding method. May be omitted.

[0012]

The catheter of the present invention comprising an inner tube having the above-described structure has an overlapping winding structure of a resin tape having excellent thickness accuracy. It is possible to reduce the thickness and to reduce the wall thickness, and the inner diameter can be enlarged as compared with that of the conventional structure having the same outer diameter of the catheter. Maintaining the same degree of drug delivery, etc., allows the outer diameter of the catheter to be reduced, thereby improving intravascular insertion.

On the inner periphery of the inner tube, a spiral small step (a step corresponding to the tape thickness) formed by the tape side edge of the resin tape continuously appears, and this spiral small step serves as a pool of lubricant. As it functions, the slipperiness of the guidewire inserted into the inner tube is improved and the catheter performance is further improved, and a spiral-shaped minute step also appears on the outer periphery of the inner tube, and it is post-formed on the outer surface of the inner tube by extrusion molding. Since it functions as a locking strip for the outer tube, the roughening of the outer periphery of the inner tube becomes unnecessary.

Further, when the wrap amount of the overlap winding is changed by a variable amount, the inner layer tube becomes rigid in direct proportion to the wrap amount and the rigidity and buckling resistance are improved. This allows the mechanical properties of each part of the catheter of the flexible tube to be intentionally adjusted and set with considerable flexibility. Therefore, depending on the degree of freedom of the adjustment setting, it is possible to impart suitable mechanical properties such that “buckling resistance and rigidity gradually increase from the distal end side to the proximal end side of the tube”, or a zone in the longitudinal direction of the tube. Separately, the amount of wrap can be set to a variable amount to provide a property that “flexibility and rigidity are in harmony” according to each part in the longitudinal direction.

Further, those using the resin tape having the net or the punching tape according to the above-described embodiment have the following effects. That is, the conventional metal braid 4 becomes unnecessary by the net having excellent mechanical strength, and the conventional complicated inspection process can be omitted. In addition, the net and the punching tape appear on the surface, and the surface roughness of the inner pipe 2 is reduced. Is improved, so that the roughening of the inner tube 2 becomes unnecessary.

[0016]

Embodiments of the present invention will be described below. First, referring to FIG. 1 showing a first embodiment of the present invention, an inner tube 2 of a resin ultrafine tube through which a guide wire (not shown) is inserted into a center hole, and an outer tube formed on the outer periphery of the inner tube 2 The inner tube 2 has a structure in which a resin tape (manufactured by Teflon) is overlapped and wound into a tube, and a known resin extrusion is formed on the outer periphery of the inner tube 2. An outer layer tube 3 is provided by a method.

That is, the inner layer tube 2 is overlapped and wound around a core bar 12 of an elongated wire material having an appropriate wire diameter by slightly overlapping the side edges of the resin tape 10 by a small amount. Then, the wound body 13 is formed on the inner tube 2 of the independent tube body by removing the wound body 13 from the cored bar 12. Thereafter, a metal braid 4 similar to the conventional one is wound around the outer periphery thereof, and an outer layer tube 3 is subsequently formed on the outer periphery thereof by a known resin extrusion method, cut into unit lengths, and laminated. It is formed into a tubular catheter 1.

The resin tape 10 may be provided with an adhesive portion 9 having an adhesive width W corresponding to the wrap amount L in advance, or the adhesive portion 9 having an adhesive automatically applied immediately before winding on the core 12. Is provided, and the adhesive portion 9 is placed on the lower side so as to be polymerized on the previously wound resin tape 10 and adhesively set, whereby the shape of the tubular body is fixed. The above-described embodiment has the above-described action, and the catheter performance such as the ability to insert into a blood vessel and the ability to feed a contrast agent is improved by reducing the thickness of the inner layer tube 2.

Next, another embodiment of the present invention will be described with reference to FIGS. 2, 3, and 4. FIG. That is, FIG.
In the inner tube 2 formed by overlappingly winding the resin tape 10 in the same manner as in the embodiment, the inner tube 2 shown in FIG. L1 · L2 in the proximal direction (also the proximal direction of the catheter 1) from the distal end portion of
L3 and L4, and in FIG. 2B, L1 and L2 gradually increase stepwise in each of the zones partitioned from the distal end to the proximal end.

In the embodiment shown in FIG. 2, the rigidity of the inner tube 2 increases in proportion to the increase of the wrap amount L, and the buckling resistance and rigidity of the tube increase. When the catheter 1 is formed as a catheter 1, the catheter 1 becomes a tube body exhibiting the mechanical properties of the inner layer tube 2, and the distal end portion is "flexible and flexible, and buckling-resistant in the proximal direction. Suitable mechanical properties "that the properties and rigidity gradually increase.

Next, in the embodiment shown in FIG. 3, in the inner tube 2 also formed by overlappingly winding a resin tape 10, a metal or resin net 11 is wound inside the resin tape 10. The inner tube 2 is a double-layered resin tape 10A with a double-layer structure or a resin tape 10B with a punching tape, which is adhered or adhered with a punching tape 10C in which small holes are densely formed. In the embodiment using the resin tape 10A with a net in this embodiment, the presence of the net 11 supplements the mechanical strength of the inner tube 2, so that the winding of the metal braid 4 in the conventional structure becomes unnecessary. Then, even if the resin tape 10A is overlapped and wound, there is no possibility that the enormous shape 6 and the protruding element wire 5 in the conventional structure are generated, so that the complicated conventional inspection process is unnecessary and the molding process of the catheter 1 is simplified. Make it more efficient. Then, since the net 11 or the punching tape 10C appears on the surface to make the outer periphery extremely rough, the conventional outer surface roughening process is unnecessary and the adhesion of the outer tube 3 is improved.

On the other hand, in the embodiment shown in FIG. 4, an outer layer 7 is provided on the outer periphery of the inner tube 2 made of the resin tape 10 which is also overlapped and wound around the inner tube 2 which is also wound with the resin tape 10 overlapped. It has a structure. In the embodiment of FIG. 4, the outer layer tube 3 by the resin extrusion molding method of the conventional structure becomes unnecessary, and the entire shape of the laminated tube structure catheter 1 is constituted by the tape having excellent wall thickness accuracy. And the degree of freedom in setting the mechanical properties in the longitudinal direction of the catheter 1 due to a change in the variation of the wrap amount L is further improved, so that the catheter performance can be particularly improved and improved.

It should be noted that the catheter 1 of the present invention is not limited to each of the above embodiments, and the inner tube 2 formed by overlappingly winding the resin film 10 is not limited to the above embodiments. It is possible to freely combine and relocate the differences represented in the above, and to implement them as specific components with necessary changes. Then, the resin tape 10 is continuously wound around the cored bar 12 by a dedicated device and wound and formed, and the formed portion is sequentially removed from the cored bar 12 and continuously formed into a long tube body. A method such as cutting and mass-producing the inner tube 2 is adopted.

[0024]

The catheter of the present invention comprises the inner tube 2 wound with an ultra-thin tape having an excellent thickness accuracy. Therefore, the thickness of the catheter tube can be made unevener than that of the conventional extrusion method. Since the catheter can be reduced in thickness and thickness can be reduced, and the inner diameter of the catheter having the same outer diameter can be made larger than that of a conventional catheter, the injectability of an angiographic agent or the like and the guidewire insertability are improved. And, if the injectability of the angiographic agent is maintained at the same level, the outer diameter of the catheter 1 can be reduced, and the insertability in the blood vessel can be improved, so that the basic performance as a medical catheter can be improved. .

In addition, since the appropriate mechanical properties which change depending on the longitudinal direction of the catheter of the flexible ultrafine tube can be intentionally adjusted and set by the change in the amount of wrapping of the resin tape, the steering property of the catheter is included. The performance is further improved and improved. In the case of using a resin tape with a mesh body and a punching tape, the need for roughening the outer peripheral surface of the inner tube and a complicated inspection process are eliminated, and the catheter molding process is simplified and made more efficient. Prevent the occurrence of defective products based on existence and improve quality reliability. There are the above useful effects.

[Brief description of the drawings]

FIG. 1 is a front view showing a structure and a molding method of a catheter according to a first embodiment of the present invention.

FIG. 2 shows a catheter according to another embodiment of the present invention;
Both (A) and (B) are front views of the inner tube.

FIG. 3 shows a catheter according to another embodiment of the present invention;
Both (A) and (B) are front views of the inner tube.

FIG. 4 is a front view of a catheter according to another embodiment of the present invention.

FIGS. 5A and 5B show a conventional catheter, wherein FIGS. 5A and 5B are front views of the catheter, and FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Catheter 2 Inner tube 3 Outer tube 4 Metal braid 5 Elementary wire 6 Huge shape 7 Outer layer 8 Lapping part 9 Adhesive part 10 Resin tape 11 Mesh body 12 Core metal 13 Winding body L Wrap width W Adhesion width

Claims (5)

[Claims] 1. A catheter comprising an inner tube made of a flexible ultrafine tube through which a guide wire is inserted into a center hole, wherein the inner tube is made of a tube in which a resin tape is overlapped and wound. 2. The catheter according to claim 1, comprising an inner tube in which the mechanical properties in the longitudinal direction of the tube are adjusted and set by changing the wrap amount of the overlap winding. 3. The catheter according to claim 1, comprising an inner tube in which a resin tape with a mesh or a resin tape with a punching tape is overlapped and wound. 4. The method according to claim 1, 2 or 3.
A catheter having a structure in which an outer layer portion formed by overlapping and winding a resin tape is provided on the outer periphery of any one of the inner layer tubes. 5. The catheter according to claim 4, wherein the mechanical properties in the longitudinal direction of the tubular body are adjusted and set by changing the wrap amount of the overlap winding of the outer layer.