JP2013022367A - Catheter and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smooth a catheter surface, to prevent displacement of a reinforcing wire material, to prevent air bubbles from remaining in a catheter, and to compatibly achieve shape retention and flexibility.SOLUTION: The catheter with a reinforcing wire material 8 includes: an inner layer 6; an intermediate layer 7 laminated on the outer periphery of the inner layer 6; the reinforcing wire material 8 wound spirally along the intermediate layer 7; and an outer layer 9 laminated on the outer periphery of the intermediate layer 7 and the reinforcing wire material 8. The reinforcing wire material 8 is arranged so as to bite into the intermediate layer 7, and the catheter is formed.

Description

  The present invention relates to a catheter having a reinforcing wire and a manufacturing method thereof.

  A catheter is a hollow medical device that is inserted into a body cavity, tube, blood vessel, or the like, and is used for, for example, suctioning a thrombus, securing a passage of a blood vessel in an obstructed or stenotic state, and injecting an angiographic contrast agent. For example, in Patent Document 1, a reinforcing wire is wound around the outer periphery of a resin layer on the inner layer side, and a resin layer on the outer layer side is covered with a reinforcing wire, thereby forming an inner layer side resin layer and an outer layer side resin layer. A catheter in which a reinforcing wire is interposed between the two is described.

JP-A-8-317986

However, in the conventional catheter, a reinforcing wire having a large outer diameter is sandwiched between the inner layer and the outer layer, so that only the reinforcing wire is disposed on the surface of the outer layer more than the other surface portion. Bulges and partially protrudes by the outer diameter of the tube, thereby forming irregularities on the entire surface of the catheter.
In particular, at the intersections of the mesh, the reinforcing wires overlap each other and the reinforcing wires have high rigidity so that they hardly collapse and deform even if they overlap. There is also a problem that the projections are partially thickened and thereby the unevenness of the entire catheter surface becomes large.

When a reinforcing wire is wound around the outer peripheral surface of the inner layer in the manufacture of a catheter having a reinforcing wire, the reinforcing wire slides and the winding pitch easily shifts, and the pressure strength of the portion where the pitch is widened by this positional shift is reduced. There was a problem to do.
In particular, at the intersection of the mesh, the reinforcing wires overlap each other. Therefore, when the other reinforcing wire is wound on one reinforcing wire, the surfaces of these reinforcing wires slide and the winding pitch easily shifts. There was also a problem.

  In addition, after winding the reinforcing wire along the outer peripheral surface of the inner layer, and covering the outer resin layer on the outer layer, when the outer layer is laminated, air is entrained between the outer peripheral surface of the inner layer and the reinforcing wire. As a result, not only the adhesion between the inner layer and the outer layer is weakened and the film is easily peeled off, but also when the outer layer is formed of a transparent or translucent material, irregularly remaining bubbles are conspicuous and have a commercial value. There was a problem of significantly lowering.

  In particular, at the intersection of the mesh, the reinforcing wires are in contact with each other, so when laminating the outer layer, air is more likely to remain in these intersections, and the outer layer is made of a transparent or translucent material. When formed, there is also a problem that more irregularly remaining bubbles become more conspicuous.

  The present invention can solve the problems caused by sandwiching the reinforcing wire between the inner layer and the outer layer, smooth the catheter surface, prevent displacement of the reinforcing wire, and prevent air bubbles from remaining in the catheter. It is for the purpose.

  In order to achieve such an object, the present invention provides an inner layer, an intermediate layer laminated on the outer periphery of the inner layer, a reinforcing wire wound spirally along the intermediate layer, and the intermediate layer and the reinforcing wire. And an outer layer laminated on the outer periphery, and the reinforcing wire is arranged so as to bite into the intermediate layer.

  In addition to the above-described features, the outer layer is formed of a soft resin, and the intermediate layer is formed of a resin that is harder than the outer layer when solidified.

  In addition to the above-described features, a second reinforcing wire is disposed between the inner layer and the intermediate layer.

  In addition, as a manufacturing method thereof, an intermediate layer is laminated in a molten state on the outer periphery of the inner layer, and the reinforcing wire is spirally wound before the intermediate layer is solidified, and then the intermediate layer is bitten into the intermediate layer. The outer layer is laminated on the outer periphery of the reinforcing wire.

The present invention having the above-described features can solve the problems caused by sandwiching the reinforcing wire between the inner and outer layers, and is arranged so that the reinforcing wire bites into the intermediate layer, and the reinforcing wire has a large cross-sectional outer diameter like the reinforcing wire. However, since the thickness of the intermediate layer does not change as a whole, the surface of the outer layer cannot be uneven due to the presence or absence of the reinforcing wire, and the catheter surface can be made smooth.
Furthermore, since the reinforcing wire is arranged so as to bite into the intermediate layer, and the movement of the reinforcing wire is suppressed in the intermediate layer, it is possible to prevent positional displacement when the reinforcing wire is wound.
Thereby, the winding pitch of a reinforcement wire can be made uniform, and it can prevent that a pressure strength falls partially.
Further, since the reinforcing wire is arranged so as to bite into the intermediate layer and air is not involved between the inner layer and the reinforcing wire, it is possible to prevent bubbles from remaining in the catheter.
Thereby, peeling of the inner layer and the outer layer due to bubbles remaining between the layers can be reliably prevented, and even if the outer layer is formed of a transparent or translucent material, the bubbles are not conspicuous and the commercial value can be maintained high. .

  Furthermore, by molding the intermediate layer with a resin that is harder than the inner layer and outer layer resins when solidified, the intermediate layer does not change shape due to changes in the internal pressure of the catheter, while preventing the catheter from being kinked or broken. When trying to bend, the entire catheter can be bent without collapsing and deforming together with the reinforcing wire, so that both shape retention and flexibility can be achieved.

In addition, when a second reinforcing wire having a smaller outer diameter than the reinforcing wire is used as the second reinforcing wire between the inner layer and the intermediate layer, the second reinforcing wire on the surface of the outer layer even when sandwiched between the inner layer and the intermediate layer Since only the arrangement position of does not protrude larger than other surface portions, the catheter surface can be made substantially smooth.
Further, since the second reinforcing wire is positioned by the lamination of the intermediate layer, it is possible to prevent the displacement of the winding pitch of both of the second reinforcing wire and the reinforcing wire, and to prevent the second reinforcement. Since there is no air entrainment at the intersection of the wire and the reinforcing wire, bubbles can be prevented from remaining in the catheter.

FIG. 1 is a plan view showing an overall configuration of a catheter according to an embodiment of the present invention. FIG. 2A is a partially cutaway perspective view of the catheter body according to the embodiment of the present invention, and FIG. 2B is a partially enlarged longitudinal sectional view of the catheter body according to the embodiment of the present invention. .

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a plan view showing an overall configuration of a catheter according to an embodiment of the present invention. A catheter 1 according to an embodiment of the present invention includes a catheter main body 2 and a hub 3 attached to the proximal end of the catheter main body 2. The catheter body 2 is composed of a flexible tubular member, and a lumen 4 is formed inside from the proximal end to the distal end. The lumen 4 functions as a guide wire lumen, and the guide wire 5 is inserted into the lumen 4 when the catheter 1 is inserted into a blood vessel. The lumen 4 can also be used as a passage for a chemical solution, an embolic substance, a contrast agent, or the like. The hub 3 functions as an insertion port for the guide wire 5 into the lumen 4, an injection port for a drug solution, an embolic material, a contrast medium, etc. into the lumen 4, and also functions as a grasping unit for operating the catheter 1. .

  FIG. 2A is a partially cutaway perspective view of the catheter body according to the embodiment of the present invention, and FIG. 2B is a partially enlarged longitudinal sectional view of the catheter body according to the embodiment of the present invention. . The catheter body 2 of the present embodiment includes an inner layer 6, an intermediate layer 7 laminated on the outer periphery of the inner layer 6, a reinforcing wire 8 wound spirally along the intermediate layer 7, and the intermediate layer 7 and the reinforcement. And an outer layer 9 laminated on the outer periphery of the wire 8.

  The inner layer 6 includes, for example, a thermoplastic resin as a main component, a plasticizer for moderately softening, a stabilizer for preventing deterioration, other lubricants, fillers, processing aids, improvement materials, and the like at a predetermined ratio. For example, it is molded in a molten state by an extrusion molding machine, and cooled into a cylindrical shape by cooling it.

  The inner layer 6 covers the inner periphery of the reinforcing wire 8 and serves as a core for disposing the reinforcing wire 8 and forms the lumen 4. The inner layer 6 can be made of the same material as that of the outer layer 9 described above, but is preferably made of a low friction material. Thereby, friction is reduced on the inner surface of the inner layer 6. As a result, the sliding resistance with the guide wire 5 inserted through the lumen 4 is reduced, and the operation of inserting the catheter 1 into the blood vessel along the preceding guide wire 5 or the guide wire 5 is removed from the catheter 1. Operation can be performed more easily and smoothly.

The low-friction material constituting the inner layer 6 may be any material that can reduce friction on the inner surface of the inner layer 6, and examples thereof include fluororesin, nylon 66, polyether ether ketone, and high-density polyethylene. . Among these, a fluorine resin is more preferable.
Examples of the fluorine-based resin include polytetrafluoroethylene, polyvinylidene fluoride, ethylene tetrafluoroethylene, perfluoroalkoxy resin, and the like. Among these, polytetrafluoroethylene is more preferable.

  Although it does not specifically limit as thickness of the inner layer 6, For example, it is preferable that it is 50 micrometers or less, and it is more preferable that it is 40 micrometers or less. If the thickness of the inner layer 6 exceeds the above-described upper limit, it is disadvantageous for reducing the diameter of the catheter body 2.

  The outer layer 9 includes, for example, a thermoplastic resin as a main component, a plasticizer for moderately softening, a stabilizer for preventing deterioration, other lubricants, fillers, processing aids, improvement materials, and the like at a predetermined ratio. For example, it is molded in a molten state by an extruder, and cooled to solidify into a transparent, translucent or opaque cylindrical shape.

  As the constituent material of the outer layer 9, a flexible material is used, for example, polyolefin such as polypropylene and ethylene-vinyl acetate copolymer, polyester such as polyamide, polyethylene terephthalate (PET), and polybutylene terephthalate (PBT). , Fluorine resin such as polyurethane, polyvinyl chloride, polystyrene resin, polytetrafluoroethylene, ethylene-tetrafluoroethylene copolymer, etc., various flexibility such as polyamide elastomer, polyurethane elastomer, polystyrene elastomer, polyester elastomer, fluorine elastomer Resin having properties, rubber materials such as silicone rubber and latex rubber, or a combination of two or more of these materials can be used.

  Although it does not specifically limit as thickness of the outer layer 9, Usually, it is preferable that it is about 0.05-0.15 mm, and it is more preferable that it is about 0.06-0.12 mm. If the outer layer 9 is thinner than the above lower limit value, the pushability and torque transmission may not be sufficiently exhibited. On the other hand, if the outer layer 9 is thicker than the aforementioned upper limit value, it is disadvantageous for reducing the diameter of the catheter body 2. In the present embodiment, the thickness of the outer layer 9 is substantially uniform from the proximal end to the distal end of the catheter body 2, but may be configured to gradually decrease in the distal direction of the catheter body 2. Thereby, the rigidity (bending rigidity) of the catheter 1 also decreases continuously. For this reason, the follow-up property and kink resistance of the catheter body 2 are improved.

  The intermediate layer 7 is made of a soft thermoplastic resin or a resin compatible with the soft resin of the inner layer 6 and the outer layer 9, and is molded in a molten state by, for example, an extrusion molding machine, and is solidified into a cylindrical shape by cooling it. The Furthermore, it is preferable to use a semi-rigid resin or a hard resin in which the amount of plasticizer is reduced so that the intermediate layer 7 becomes harder than the soft thermoplastic resin of the outer layer 9 when solidified.

  As the constituent material of the intermediate layer 7, a material having flexibility is used. For example, polyolefin such as polypropylene and ethylene-vinyl acetate copolymer, polyamide, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and the like. Various types of resins such as polyester, polyurethane, polyvinyl chloride, polystyrene resin, fluororesin such as polytetrafluoroethylene, ethylene-tetrafluoroethylene copolymer, polyamide elastomer, polyurethane elastomer, polystyrene elastomer, polyester elastomer, fluorine elastomer, etc. Resins having flexibility, rubber materials such as silicone rubber and latex rubber, or a combination of two or more of these materials can be used.

  The thickness of the intermediate layer 7 is preferably larger than the thickness of the reinforcing wire 8, and is usually preferably about 0.03 to 0.08 mm, more preferably about 0.05 to 0.06 mm. preferable.

  Examples of the reinforcing wire 8 include at least one of a metal member and a non-metal member. As a material constituting the metal member, for example, one or more of stainless steel, nickel-titanium alloy, platinum, iridium, tungsten and the like can be used. On the other hand, as a material constituting the nonmetallic member, for example, one or two or more of carbon, polyamide, polyethylene terephthalate, polybutylene terephthalate, and the like can be used.

  In particular, the reinforcing wire 8 is preferably made of a radiopaque material such as tungsten, platinum, iridium, or an alloy containing these. As a result, as described in detail in the description of the region 42 described later, the winding pitch of the reinforcing wire 8 is reduced only at the distal end portion in the vicinity of the distal end of the catheter body 2 (in the present embodiment, the region 42). The distal end portion of the reinforcing wire 8 can function as an X-ray opaque marker.

  Further, the reinforcing wire 8 is not limited to a circular shape as shown in the figure, and may be a flat shape, that is, a ribbon shape (band shape). When the cross-sectional shape of the reinforcing wire 8 is circular, the diameter of the reinforcing wire 8 is preferably about 10 to 100 μm, more preferably about 30 to 60 μm. Moreover, when the reinforcing wire 8 is ribbon-shaped, it is preferable that the width is about 0.1 to 1.0 mm and the thickness is about 0.04 to 0.05 mm. By arranging such a reinforcing wire 8, a sufficient reinforcing effect can be obtained with a relatively thin thickness. For this reason, the catheter main body 2 having such a reinforcing wire 8 is advantageous in reducing the diameter.

  The reinforcing wire 8 is arranged so that each of the reinforcing wires 8 bites into the intermediate layer 7 by spirally winding a plurality of reinforcing wires 8 along the outer peripheral surface 7 a of the intermediate layer 7.

  Furthermore, it is preferable to arrange the second reinforcing wire 10 between the inner layer 6 and the intermediate layer 7 as necessary. As the second reinforcing wire 10, a reinforcing wire thinner than the outer diameter of the reinforcing wire 8 or a wire similar to the reinforcing wire 8 described above is used. Specifically, a reinforcing wire having a large outer diameter as a reinforcing wire 8 is inserted into the intermediate layer 7 made of a semi-rigid resin that is harder than the outer layer 9 when solidified, and between the inner layer 6 and the intermediate layer 7. The case where the second reinforcing wire 10 thinner than the outer diameter of the reinforcing wire 8 is spirally wound so as to be opposite to the inclination angle of the reinforcing wire 8 is shown.

  And as an example of the manufacturing method of such a catheter 1, after the inner layer 6 is extrusion-molded with an extruder and this is cooled and solidified, the intermediate layer 7 is melted by extrusion molding on the outer periphery of the inner layer 6 The intermediate layer 7 is wound in a spiral manner before the intermediate layer 7 is solidified, so that the intermediate layer 7 is bitten into the intermediate layer 7, and then the outer layer 9 is extruded on the outer periphery of the intermediate layer 7 and the reinforcing wire 8. Thus, the inner layer 6, the intermediate layer 7 and the outer layer 9 are bonded and fused together to be integrated.

Next, a specific method for manufacturing the catheter 1 will be described.
First, a soft resin that becomes the inner layer 6 is extruded by an extruder (not shown), and after cooling and solidifying the inner layer 6, the second reinforcing wire 10 is formed along the outer peripheral surface 6 a of the inner layer 6. Is spirally wound with a predetermined tension.

  Thereafter, the semi-rigid resin that becomes the intermediate layer 7 is extruded in a molten state by an extruder so as to cover the outer peripheral surface 6a of the inner layer 6 and the second reinforcing wire 10, and the reinforcing wire 8 is formed before it solidifies. Then, it is spirally wound with a predetermined tension by a winding device (not shown). As a result, the reinforcing wire 8 bites into the molten intermediate layer 7 toward the inner layer 6, and a concave groove 7 b is formed in the outer peripheral surface 7 a of the intermediate layer 7 by this biting.

  Subsequently, after the intermediate layer 7 is cooled and solidified, the soft resin that becomes the outer layer 9 is extruded by an extruder so as to cover the outer peripheral surface 7a, the concave groove 7b, and the reinforcing wire 8 of the intermediate layer 7. The outer layer 9 is solidified by being molded, and the catheter body 2 is completed.

According to the catheter 1 of the present embodiment, the reinforcing wire 8 is arranged so as to bite into the intermediate layer 7, so that even if the reinforcing wire 8 has a large cross-sectional outer diameter like the reinforcing wire, the thickness of the intermediate layer 7 is entirely Therefore, the surface of the outer layer can be prevented from being uneven by the reinforcing wire 8, so that the catheter surface can be smoothed.
Furthermore, since the reinforcing wire 8 bites into the intermediate layer 7 so that the reinforcing wire 8 is immovably disposed in the intermediate layer 7, it is possible to prevent displacement of the reinforcing wire when it is wound.
In addition, since the reinforcing wire 8 bites into the intermediate layer 7, air is not caught between the inner layer 6 and the reinforcing wire 8, so that bubbles can be prevented from remaining in the catheter.

  According to the catheter 1 of the present embodiment, the portion where the reinforcing wire 8 is disposed is not easily crushed, and the intermediate layer 7 made of a semi-rigid resin is disposed between the inner layer 6 and the outer layer 9, so that the catheter is kinked or broken. Even when the internal pressure of the catheter changes, the shape of the intermediate layer 7 does not change, such as the diameter of the intermediate layer 7 being reduced or expanded, and when a force acts to bend the catheter, Since the inner layer 6 and the outer layer 9 can be bent without being crushed and deformed, both shape retention and flexibility can be achieved.

  Furthermore, even if the second reinforcing wire 10 is sandwiched between the inner layer 6 and the intermediate layer 7, if the diameter of the second reinforcing wire 10 is smaller than that of the reinforcing wire 8, only the arrangement location of the second reinforcing wire 10 is present on the surface of the outer layer 9. Since it does not protrude more than other surface portions, the catheter surface can be made substantially smooth.

In addition, since the second reinforcing wire 10 is positioned by the subsequent lamination of the intermediate layer 7, the winding pitch of the second reinforcing wire 10 and the reinforcing wire 8 is not misaligned at the intersection of the second reinforcing wire 10 and the reinforcing wire 8. Since there is no air entrainment at the intersection of the second reinforcing wire 10 and the reinforcing wire 8, no bubbles remain in the catheter.
In addition, since the second reinforcing wire 10 is balanced with the reinforcing wire 8, the catheter 1 can be prevented from stretching or twisting.

  In the previous embodiment, the case where the second reinforcing wire 10 is spirally wound between the inner layer 6 and the intermediate layer 7 so as to be opposite to the inclination angle of the reinforcing wire 8 is shown. Without limitation, a second reinforcing wire 10 having the same outer diameter as that of the reinforcing wire 8 may be spirally wound between the inner layer 6 and the intermediate layer 7. In this case, the second intermediate layer is laminated in a molten state between the inner layer 6 and the intermediate layer 7, and the second reinforcing wire 10 is wound before the second intermediate layer is solidified to wind the second intermediate layer. It is preferable to bite into the intermediate layer. Furthermore, a plurality of second reinforcing wires 10 may be arranged at equal intervals in the circumferential direction so as to extend in the axial direction of the catheter. Further, the inner layer 6 is not limited to the illustrated example, and an innermost layer (not shown) made of a raw material adapted to the fluid passing through the catheter is provided inside the inner layer 6 as necessary, or an outermost layer for protection on the outer side of the outer layer 9. (Not shown) can also be provided.

  DESCRIPTION OF SYMBOLS 1 ... Catheter, 2 ... Catheter main body, 6 ... Inner layer, 7 ... Middle layer, 8 ... Reinforcement wire, 9 ... Outer layer, 10 ... Second reinforcement wire

Claims (4)

An inner layer, an intermediate layer laminated on the outer periphery of the inner layer, a reinforcing wire wound spirally along the intermediate layer, and an outer layer laminated on the outer periphery of the intermediate layer and the reinforcing wire,
A catheter, wherein the reinforcing wire is arranged so as to bite into the intermediate layer.   The catheter according to claim 1, wherein the outer layer is formed of a soft resin, and the intermediate layer is formed of a resin that is harder than the outer layer when solidified.   The catheter of Claim 1 or 2 arrange | positioned so that a 2nd reinforcement wire may be inserted | pinched between the said inner layer and the said intermediate | middle layer.   An intermediate layer is laminated on the outer periphery of the inner layer in a molten state, and before the intermediate layer is solidified, the reinforcing wire is wound spirally so as to bite into the intermediate layer, and then the outer layer is formed on the outer periphery of the intermediate layer and the reinforcing wire. A catheter manufacturing method characterized by being laminated.

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