JPH09294810A - Catheter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To omit the complicated inspection process for confirming whether a strand is protruded or not, remarkably improve safety and quality assurance, and promote the cost reduction by providing a resin intermediate layer between the outer periphery of a metal braid and the inner periphery of an outer tube. SOLUTION: This catheter 1 made of a flexible extra fine tube is constituted of a metal braid 4 braided with a stainless extra fine wire strand 5 into a net shape and wound on the outer periphery and a resin outer tube 3 containing a resin inner tube layer 2 inserted with an extra fine guide wire at the central portion. A thin resin intermediate layer 7 is inserted between the metal braid 4 and the outer layer tube 3 to form a tube body, and the inner layer tube 2 wound with the metal braid 4, the intermediate layer 7, and the outer layer tube 3 are integrated to form the catheter 1 made of a single extra fine tube. The catheter l has a uniform diameter and is smooth, and it can form the tube outer periphery where no strand 5 is protruded at all.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art A catheter 1 of a medical instrument (see FIG. 2) has a resin inner layer tube 2 made of Teflon or the like with a metal braid 4 wrapped around an outer layer tube 3 made of a polyamide or polyurethane resin. It has a basic structure consisting of flexible multilayer ultrafine tubules that are stacked, and is inserted into the blood vessel from its tip (sometimes rotated a little) to reach a predetermined position of the patient's coronary artery and set. A predetermined treatment such as contrast enhancement is performed.

Then, the metal braid 4 is attached to the catheter 1 to be inserted into a blood vessel having a tortuous and complicated path.
A metal braid 4 wound around the inner layer tube 2 so as to impart appropriate rigidity and elasticity (recovery elasticity from bending deformation) so that the braided wire 5 is not easily loosened and loses elasticity. The ends of the inner layer pipe 2 are formed by butt welding the wires 5 to each other.
Is disposed between the outer layer tube 3 and the outer layer tube 3.

[0004]

In the above-mentioned conventional catheter 1, the metal braid 4 knitted in a long and wide shape is cut into a predetermined size, and the ends of the strands 5 of the cut portion are welded to each other. After that, it is wrapped around the inner layer tube 2. However (see FIG. 2 (B)), due to the release of the braid restraint by cutting, the welding stress, etc., it is qualitative that the end portion of the metal braid 4 wound around the inner layer tube 2 has an enormous shape 6 that bulges outward. is there. Therefore, the outer layer tube 3 in that portion may swell and hinder the uniformity of the outer diameter, and the wire 5 in the enlarged shape portion 6 may protrude from the outer periphery of the outer layer tube 3. The insertability into the blood vessel is reduced and the blood vessel wall is damaged.

Therefore, in order to prevent the safety from being hindered by the protrusion of the strand 5, the outer periphery of the outer layer tube 3 at the portion where the end portion of the metal braid 4 is present is magnified by the "extension strand". There is no choice but to perform a manual inspection carefully for "presence / absence". However, the inspection work is a round wire with a wire diameter of approximately 0.075 mm (or 0.03 mm thick ×
Since it is a micro inspection to confirm the very small amount of protrusion of 0.15 mould width square wire), a lot of inspection man-hours are required and there is a possibility that the protrusion is misidentified as "good product without protrusion line". , Lacks quality reliability.

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

[0007]

The catheter of the present invention which solves the above technical problems is described as follows: "A resin inner layer tube in which a metal braid is wrapped around the outer periphery, and a resin outer layer tube including the inner layer tube. And a resin intermediate layer is provided between the outer circumference of the metal braid and the inner circumference of the outer layer tube.

That is, in the catheter of the present invention, by providing the above-mentioned intermediate layer, the enormous deformation appearing at the end of the metal braid and the protrusion of the wire are suppressed, and the outer layer tube has no bulging portion. The structure is characterized by a uniform tubular smooth tube and a structure that prevents the strands of wire from protruding from the outer layer tube. From the technical intention, the intermediate layer may be placed on a metal braid, if necessary. After the formation, a forming means for forming an outer layer pipe on the outer circumference of the intermediate layer is adopted.

[0009]

In the catheter of the present invention having the above-mentioned structure, even if the intermediate layer is partially expanded due to the enormous deformation of the metal braid, the partially expanded shape of the intermediate layer can be obtained by extrusion molding the outer layer pipe in the post-process. Since it is absorbed by the thickness of the outer layer pipe, the outer periphery of the outer layer pipe can be formed to have a smooth outer periphery with no bulging portion.

The intermediate layer suppresses the enormous deformation of the metal braid and the protrusion of the wire, and even if there is a wire protruding from the intermediate layer, the protruding portion is absorbed in the layer of the outer layer pipe. To be done. And, for example, when extrusion molding of the outer layer tube, the outer circumference of the intermediate layer can be pressed with a straightening roller, and the protruding strands can be removed by passing through a die, so that there is no strand protrusion of the metal braid. Can be molded on the outer periphery of high quality pipe.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The catheter of the present invention described above is implemented as in the following examples.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A catheter 1 according to an embodiment of the present invention will be described in detail with reference to FIG. That is, a metal braid 4 in which a stainless ultrafine wire 5 is braided in a mesh shape is wound around the outer periphery, and an inner tube 2 made of resin is inserted into the center portion of which an ultrafine wire guide wire (not shown) is inserted. In a catheter 1 which is a flexible ultrafine tubular body made of a resin outer layer tube 3 enclosing the inner layer tube 2, a thin resin intermediate layer 7 is provided between the metal braid 4 and the outer layer tube 3. The inner layer tube 2 around which the metal braid 4 is wound, the intermediate layer 7, and the outer layer tube 3 are integrated to form a single ultrafine catheter 1.

The catheter 1 of this embodiment is separately molded in advance and cut into a required size, and the inner layer tube 2 around which the metal braid 4 having the ends of the strands 5 of the cut portion welded together is wound. The intermediate layer 7 is molded on the outer periphery by a known resin extrusion molding, and then the outer layer tube 3 is molded on the outer periphery of the intermediate layer 7 by the extrusion molding method. The inner layer tube 2 is made of Teflon. The middle layer 7 and the outer layer tube 3 are made of 6 nylon or 12 nylon.
Inner diameter: 2.15 grit, outer layer tube 3 outer diameter: 2.70 grit, middle layer 7 wall thickness: 0.08 grit, outer layer tube 3 wall thickness: 0.145 grit It is the original.

The catheter 1 of the embodiment shown in FIG. 1 has the above-mentioned function, has a uniform diameter, is smooth, and has a wire 5
Since it can be molded into a tube outer circumference having no protrusions, the conventional cumbersome outer circumference inspection is unnecessary, and a high quality and low cost catheter can be provided.

The catheter of the present invention is not limited to the above-mentioned embodiment, but the outer circumferences of the inner layer tube 2 and the intermediate layer 7 are roughened by etching or the like to improve the adhesion of the intermediate layer 7 and the outer layer tube 3. May be planned.

[0016]

As described above, the catheter of the present invention comprises an inner layer tube in which a metal braid is wrapped around the outer periphery thereof, and the metal braid has a smooth and beautiful outer periphery without the wire sticking out. Since it can be molded into a tubular body, the complicated inspection process for checking the presence or absence of wire extrusion is omitted, and there is no risk of defective wire extrusion, which further improves the safety and quality assurance of medical catheters. As a result, there are various useful effects that can reduce the cost of the catheter 1.

[Brief description of drawings]

FIG. 1 is a front view of a catheter according to an embodiment of the present invention.

2A and 2B show a conventional catheter, in which FIG. 2A is a front view thereof, and FIG. 2B is a front view showing an enlarged shape and a protruding state of a metal braid.

[Explanation of symbols]

 1 Catheter 2 Inner Layer Tube 3 Outer Layer Tube 4 Metal Braid 5 Elementary Wire 6 Enlarged Shape 7 Intermediate Layer

Claims (1)

[Claims] 1. A catheter comprising a resin inner layer tube having a metal braid wrapped around the outer periphery thereof and a resin outer layer tube enclosing the inner layer tube, wherein the outer periphery of the metal braid and the outer layer tube are A catheter characterized by a structure in which a resin intermediate layer is provided between the inner circumference and the inner circumference.