WO2015119075A1

WO2015119075A1 - Medical catheter and method for producing medical catheter

Info

Publication number: WO2015119075A1
Application number: PCT/JP2015/052833
Authority: WO
Inventors: 宮城一貴; 佐藤由希子
Original assignee: テルモ株式会社
Priority date: 2014-02-05
Filing date: 2015-02-02
Publication date: 2015-08-13

Abstract

A medical catheter (10) has a long, elongated body (12) comprising: an inner layer (20); a reinforcement layer (22) composed of a wire (26) surrounding the outside of the inner layer (20); and an outer layer (24) covering the outside of the reinforcement layer (22). In a predetermined range of the longitudinal direction of the elongated body (12), the following are provided: a first region (30) where the peripheral surface of the wire (26) is partially or entirely covered in the peripheral direction by a covering material (28) separate from the inner layer (20) and the outer layer (24); and a second region (32) where the wire (26) is not covered by the covering material (28) and is exposed.

Description

Medical catheter and method for manufacturing medical catheter

The present invention relates to a medical catheter used for treatment or diagnosis of a living organ and a method for manufacturing the medical catheter.

In recent years, treatment of vascular lesions using a catheter has been actively performed for the reason that there is very little surgical invasion. In a procedure using a catheter, the catheter is delivered to the vicinity of the target site, and the target site is diagnosed or treated via the catheter. A catheter used for such an application is required to have excellent operability so that it can be quickly and selectively inserted into a vascular system having a thin and complicated pattern.

For example, a catheter for diagnosing or treating a target site includes a microcatheter for vascular embolization in which various therapeutic agents or contrast agents are administered and injected. The microcatheter is delivered to a target site by advancing thin peripheral blood vessels having many branches and complicatedly meandering. Therefore, the microcatheter is required to have torque transmission and pushability as well as kink resistance that does not cause the catheter to be bent at a curved portion of a blood vessel.

In order to improve the operability of the catheter in response to such a request, it is known that the medical catheter controls the rigidity of the catheter over the entire length of the catheter. In addition, a multilayered catheter in which a reinforcing layer is provided between an inner layer and an outer layer in order to improve kink resistance is also known.

For example, in Japanese Patent Laid-Open No. 2006-34347, the rigidity of the catheter is controlled by adjusting the winding state of the strands constituting the reinforcing layer of the catheter, that is, by causing the arrangement of the strands to be sparse and dense. It is disclosed. Thereby, the catheter is set so that the rigidity of the proximal end portion near the hub is high and the rigidity of the distal end portion on the opposite side is low (has flexibility). Japanese Unexamined Patent Application Publication No. 2007-89847 discloses that the rigidity is controlled by changing the thickness of the outer layer of the catheter in the axial direction.

However, in the catheter disclosed in Japanese Patent Application Laid-Open No. 2006-34347, the rigidity is controlled by the winding state of the strands constituting the reinforcing layer, so that the connectivity between the inner layer and the outer layer is reduced at a portion where the inner layer is wound many times. As a result, operability decreases. Further, in the catheter manufacturing process, it is necessary to wind the wire material around the inner layer with high accuracy, and the control of the winding device for winding the wire material becomes complicated, and the winding work takes a lot of time. .

In the catheter disclosed in Japanese Patent Application Laid-Open No. 2007-89847, the rigidity is controlled by stacking a plurality of outer layers, so there is a possibility that an abrupt stepped portion is formed in the outer layer and the outer layer is peeled off. Further, in the catheter manufacturing process, an operation of covering the reinforcing layer with a plurality of outer layers and changing the thickness of the outer layer is required, resulting in inconveniences such as an increase in the number of parts and work man-hours.

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a medical catheter capable of controlling the rigidity of the entire length of the catheter with a simple structure and operation, and a method for manufacturing the medical catheter. .

In order to achieve the above object, a medical catheter according to the present invention is a long body having a lumen including an inner layer, a reinforcing layer that covers the outer side of the inner layer, and an outer layer that covers the outer side of the reinforcing layer. The reinforcing layer includes a wire wound or braided on the inner layer, and the long body has a first region and a second region along a longitudinal direction of the long body, In the first region, a coating material that is formed separately from the inner layer and the outer layer and covers the peripheral surface of the strand is provided, and in the second region, the coating material is provided on the peripheral surface of the strand. The covering material that is not covered or is thinner than the covering material that is provided on the peripheral surface of the wire in the first region is provided.

According to the above, the medical catheter includes the first region composed of the strands and the covering material covering the peripheral surface of the strands, and the covering material is not covered on the peripheral surface of the strands or the element in the first region. It is comprised by the 2nd area | region where the thin coating material thinner than the coating material provided in the surrounding surface of the line | wire is provided. Therefore, the rigidity of the first region and the second region can be controlled by the amount of the covering material covering the peripheral surface of the strand, and different rigidity can be provided to the medical catheter with a simple configuration. That is, in the medical catheter, the rigidity of the medical catheter can be appropriately set by the covering material that covers the periphery of the strand, without changing the number of windings of the strand or the thickness of the outer layer. Moreover, the adhesiveness to the inner layer and outer layer of a strand can also be improved by providing a coating | covering material in the surrounding surface of a strand. Furthermore, the strand covered with the covering material can be easily formed. Therefore, according to the present invention, it is possible to simplify the manufacture of a medical catheter with controlled rigidity, greatly shorten the working time, and reduce the manufacturing cost.

In addition to the above configuration, the second region may be provided on the tip side of the first region.

As described above, the medical catheter can be configured flexibly on the distal end side of the elongated body by providing the second region on the distal end side relative to the first region. Can be improved. Further, when the thickness of the outer layer of the first region and the second region is the same, the second region on the distal end side of the medical catheter is not covered with the covering material on the peripheral surface of the strand, or the first region By covering with a coating material that is thinner than the coating material that covers the peripheral surface of the strands of the region, it is possible to achieve a reduction in the outer diameter of the long body from the first region, It can be easily adapted to a thin living body lumen. Moreover, even if the outer diameter of the first region and the second region are made the same by making the outer layer of the second region thicker than the first region, the medical catheter is a member whose outer layer is more flexible than the covering material. By comprising in this, the front end side of a long body can be constituted flexibly.

The elongated body has an intermediate region between the first region and the second region, and in the intermediate region, from the distal end portion of the first region toward the proximal end portion of the second region. The amount of the covering material covering the peripheral surface of the strand may be reduced.

In this way, the elongated body reduces the amount of the covering material that covers the peripheral surface of the strand as it goes from the first region to the second region in the intermediate region, so that the long body is at the boundary between the first region and the second region. Stiffness change can be made smooth. Accordingly, the medical catheter prevents a step having different rigidity at the boundary between the first region and the second region of the long body, and a step having different rigidity in a curved portion such as a blood vessel becomes a starting point of the kink. This can be suppressed. For example, in the cross section in the axial direction of the long body, the amount of the covering material that covers the peripheral surface of the strand may be reduced from the distal end portion of the first region toward the proximal end portion of the second region. Further, in the axial section of the long body, the same applies even if the thickness of the covering material covering the peripheral surface of the strand decreases from the distal end portion of the first region toward the proximal end portion of the second region. effective.

Further, the thickness of the covering material may continuously change along the longitudinal direction of the reinforcing layer.

As described above, since the wall thickness of the covering material is continuously changed, a sudden change in rigidity is suppressed in the axial direction of the long body. For this reason, generation | occurrence | production of the kink etc. at the time of delivery of a long body, etc. can be reduced.

Furthermore, the wall thickness of the covering material may become thinner toward the tip side of the reinforcing layer.

In this way, the thickness of the covering material becomes thinner as it goes toward the distal end side, so that the rigidity of the elongated body on the distal end side can be changed smoothly (tapered), and the delivery performance of the elongated body is improved. Can be increased.

Alternatively, the first region may have a portion where a plurality of the covering materials are stacked on the strand.

Thus, since the function of the covering material can be easily changed by laminating a plurality of covering materials, the rigidity of the long body can be designed more freely.

In addition, in order to achieve the above object, the method for manufacturing a medical catheter according to the present invention includes an inner layer forming step of forming an inner layer by covering the periphery of the core wire in the circumferential direction, and a covering material for the peripheral surface of the strand A reinforcing layer forming step of forming a reinforcing layer having a first region by enclosing the outer side of the inner layer with a covering wire covered with a wire, and after the reinforcing layer forming step, a part of the covering material of the covering wire is removed or A reinforcing layer processing step of forming a second region different from the first region in the reinforcing layer by reducing the outer layer forming step of forming an outer layer covering the outside of the reinforcing layer after the reinforcing layer processing step. It is characterized by providing.

As described above, in the method for manufacturing a medical catheter, the inner layer forming step, the reinforcing layer forming step, the reinforcing layer processing step, and the outer layer forming step are performed to cover the periphery of the strand with a covering material in a predetermined range in the axial direction. A long body having a region can be easily manufactured. Thereby, the elongate body can obtain different rigidity in the first region and the second region. And when controlling the rigidity of an elongate body, since it can carry out with a simple work procedure, it becomes possible to shorten work time significantly and to reduce manufacturing cost.

In this case, in the reinforcing layer treatment step, the molded article on which the reinforcing layer is formed may be immersed in a solution that dissolves the covering material while changing the immersion time in the axial direction.

Thus, by changing the immersion time of the molded product in the solution in the axial direction, a coating material whose thickness changes in the axial direction can be easily formed.

According to the medical catheter and the method for manufacturing a medical catheter according to the present invention, the long body of the medical catheter can freely control the rigidity of the long body by a simple operation. Moreover, the adhesiveness with an inner layer and an outer layer can also be controlled by the coating | covering material which covers the surrounding surface of a strand.

1A is a side view showing the overall configuration of a medical catheter according to an embodiment of the present invention, FIG. 1B is a side cross-sectional view of the IB portion of the medical catheter of FIG. 1A, and FIG. It is side surface sectional drawing of IC part of 1A medical catheter. 2A is a side view showing a part of a long body having an intermediate region, FIG. 2B is a side sectional view of a IIB portion of the long body of FIG. 2A, and FIG. 2C is a long side view of FIG. 2A. 2D is a side sectional view of the IIC portion of the body, and FIG. 2D is a side sectional view of the IID portion of the elongated body of FIG. 2A. 3A is a side view showing a first molded product formed by the catheter inner layer forming step of FIG. 1A, and FIG. 3B shows a second molded product formed by the reinforcing layer forming step of the catheter of FIG. 1A. It is a side view. It is the schematic which shows the implementation of the reinforcement layer process process of the catheter of FIG. 1A, and the 3rd molded product shape | molded. FIG. 5A is a side view showing a fourth molded product formed by the outer layer forming step of the catheter of FIG. 1A, and FIG. 5B is an explanation showing a long body formed by the catheter manufacturing method and its rigid state. FIG. 6A is a side view showing a long body according to a first modification, FIG. 6B is a side sectional view of a VIB portion of the long body of FIG. 6A, and FIG. 6C is a long body of FIG. 6A. 6D is a side sectional view of the VID portion of the elongated body of FIG. 6A, and FIG. 6E is a side sectional view of the VIE portion of the elongated body of FIG. 6A. 7A is a side view showing a long body according to a second modification, FIG. 7B is a side sectional view of a VIIB portion of the long body of FIG. 7A, and FIG. 7C is a long body of FIG. 7A. It is side surface sectional drawing of the VIIC part. 8A is a side view showing a long body according to a third modification, FIG. 8B is a side sectional view of a VIIIB portion of the long body of FIG. 8A, and FIG. 8C is a long body of FIG. 8A. It is side surface sectional drawing of a VIIIC part.

Hereinafter, preferred embodiments of the medical catheter according to the present invention will be described in detail with reference to the accompanying drawings.

The medical catheter according to the present invention is used in an intervention technique for treating or diagnosing a desired position (target site) of a living organ through a living body lumen. The living body lumen in which the medical catheter is used is not particularly limited, and examples thereof include blood vessels, bile ducts, trachea, esophagus, urethra, nasal cavity, and other organs. In the following description, medical catheters used for blood vessel treatment will be described in detail.

As shown in FIG. 1A, a medical catheter 10 (hereinafter, also simply referred to as a catheter 10) has a flexible long body 12 and a hub 14 connected to the proximal end side of the long body 12. . The long body 12 is a tubular body that is inserted into a blood vessel during a procedure, and the hub 14 is a portion that is grasped by an operator in order to operate the long body 12 inserted into the blood vessel.

The hub 14 of the catheter 10 transmits the advance / retreat operation, rotation operation, and the like by the operator to the long body 12 by firmly fixing the long body 12 inside. The hub 14 is configured to have a larger diameter and rigidity than the long body 12 so that an operator can easily hold the hub 14 during a procedure. The hub 14 has a hollow portion 14a therein and a base end opening 14b communicating with the hollow portion 14a. The hub 14 may be provided with a port corresponding to the usage of the lumen when the long body 12 is provided with a plurality of lumens. Furthermore, the catheter 10 may be provided with an appropriate operation mechanism (not shown) capable of operating the treatment portion 16 of the elongated body 12 near the hub 14 or the hub 14.

The long body 12 of the catheter 10 is of an appropriate length so that the proximal end of the long body 12 and the hub 14 are exposed outside the patient's body. Therefore, it is preferable that the catheter 10 is prepared with a plurality of long bodies 12 having different lengths within a range of about 300 to 2000 mm, for example, and can be arbitrarily selected by the operator.

Also, the outer diameter of the long body 12 is formed smaller than the inner diameter of the blood vessel to be delivered. For example, the catheter according to the present invention can control the rigidity with a simple configuration as described later, and can enhance the operability of the catheter. For this reason, the elongated body 12 is optimal for a catheter that needs to be reduced in diameter as used in the treatment of peripheral blood vessels. As an example, there is a microcatheter used for a thin peripheral blood vessel having a diameter of about 3 mm or less that is complicatedly meandered with many branches.

The catheter 10 according to the present embodiment is not limited to a microcatheter, and examples thereof include a guiding catheter, a contrast catheter, an ultrasonic catheter, a balloon catheter, an atherectomy catheter, an endoscope catheter, and a stent. The present invention can be applied to various catheters such as an indwelling delivery catheter, a drug solution administration catheter, an embolization catheter, and a sheath (for example, a guiding sheath) having a metal reinforcement.

Inside the long body 12, one or a plurality of lumens 18 (lumen) are provided along the axial direction (longitudinal direction) of the long body 12. The lumen 18 communicates with the hollow portion 14a and the base end opening 14b of the hub 14, and is used for various applications during a procedure such as inserting a guide wire (not shown) for guiding the long body 12. For example, in the case of a balloon catheter or the like, the long body 12 may be configured as a so-called rapid exchange type in which a guide wire is exposed from the lumen 18 to the outside at an intermediate position in the axial direction.

A treatment unit 16 for performing treatment or diagnosis is provided on the distal end side of the long body 12. As an example of the treatment portion 16, an opening portion 18 a communicating with the lumen 18 can be cited. In addition to the guide wire, the opening 18a can perform various treatments depending on the procedure, such as delivering another catheter 10, discharging a discharge, or sucking a substance in the body. Of course, the treatment section 16 can apply various mechanisms that can be used for treatment or diagnosis. Although not specifically illustrated in FIGS. 1A to 1C, for example, the treatment section 16 is provided on the long body 12. Therapeutic devices such as balloons and stents.

The long body 12 preferably has appropriate physical properties (rigidity, flexibility, hardness, strength, slipperiness, kink resistance, stretchability, etc.) corresponding to blood vessels that are curved and bent in a complex manner in the body. For this reason, the elongate body 12 is comprised by the multilayered structure which laminated | stacked the inner layer 20, the reinforcement layer 22, and the outer layer 24, as shown to FIG. 1B and FIG. 1C.

The inner layer 20 of the long body 12 constitutes the inner wall of the lumen 18 near the axis of the long body 12. For this reason, the inner layer 20 is preferably formed so that the fluid and the guide wire are slippery and relatively hard compared to the outer layer 24. The material constituting the inner layer 20 is not particularly limited. For example, a polyolefin resin such as high density polyethylene, polypropylene, polybutene, vinyl chloride, ethylene-vinyl acetate copolymer, or a polyolefin elastomer thereof, fluorine Resin or fluorine-based elastomer, methacrylic resin, polyphenylene oxide, modified polyphenylene ether, polyethylene terephthalate, polybutylene terephthalate, polyether ether ketone, polyamide imide, polyether imide, polyether sulfone, cyclic polyolefin, polyurethane elastomer, polyester elastomer , Polyamide or polyamide elastomer, polycarbonate, polyacetal, styrene resin or styrene Elastomer, thermoplastic polyimide and the like.

The reinforcing layer 22 is provided mainly for enhancing the rigidity and elasticity of the long body 12 and improving the delivery performance of the long body 12. The reinforcing layer 22 is formed by winding a wire 26 made of a metal material or a resin material in a coil shape around the outer peripheral surface of the inner layer 20 (see also FIG. 3B). In particular, it is preferable to apply a metal material to the strand 26 so that the shape of the reinforcing layer 22 can be easily maintained and manufactured. Examples of the metal material constituting the strand 26 include pseudoelastic alloys (including superelastic alloys) such as Ni—Ti alloys, shape memory alloys, stainless steel (for example, SUS304, SUS303, SUS316, SUS316L, SUS316J1). SUS316J1L, SUS405, SUS430, SUS434, SUS444, SUS429, SUS430F, SUS302, etc.), cobalt alloys, noble metals such as gold and platinum, tungsten alloys, carbon materials (including piano wires), etc. Is mentioned.

The outer layer 24 covers the outer side of the inner layer 20 and the reinforcing layer 22 and constitutes the surface (external appearance) of the long body 12. Since the outer layer 24 is preferably formed so as to be slippery in the blood vessel and not to damage the blood vessel, a softer material than the inner layer 20 may be applied. The material constituting the outer layer 24 is not particularly limited. For example, LDPE (low density polyethylene), EVA (ethylene vinyl acetate), EAA (ethylene acrylic acid copolymer), soft polyester elastomer, soft polyurethane Elastomer, SEBS (styrene ethylene butylene block copolymer), polyethylene elastomer, polypropylene elastomer, polybutene elastomer, polyamide elastomer, soft vinyl chloride, anhydrous maleic acid elastomer, polyolefin elastomer, fluorine elastomer, polyurethane elastomer, styrene elastomer, etc. And various thermoplastic elastomers.

Further, the long body 12 has a predetermined boundary (not shown) in the axial direction as a base point, and the second region 32 on the distal end side from the boundary is more rigid than the first region 30 on the proximal end side from the boundary. Configured to be low. For this reason, the catheter 10 realizes the change in the rigidity of the first region 30 and the rigidity of the second region 32 by providing the covering material 28 on the strands 26 constituting the reinforcing layer 22.

Specifically, as shown in FIG. 1C, the first region 30 is a covered region in which the strands 26 of the reinforcing layer 22 are covered with a covering material 28. On the other hand, as shown in FIG. 1B, the second region 32 is an uncovered region in which the strands 26 of the reinforcing layer 22 are not covered with the covering material 28. That is, the strand 26 is formed in a continuous coil shape from the distal end to the proximal end, but the covering material 28 is not covered from the distal end to the middle position in the axial direction. A covering material 28 is covered on the surface. The covering material 28 in the first region 30 covers the entire periphery by circling the peripheral surface of the strand 26 along the circumferential direction.

In the long body 12, the thickness of the covering material 28 that covers the peripheral surface of the strand 26 in the second region 32 is larger than the thickness of the covering material 28 that covers the peripheral surface of the strand 26 in the first region 30. If it is thin, the second region 32 on the distal end side is configured to have lower rigidity than the first region 30 on the proximal end side. Further, when the covering material 28 covering the peripheral surface of the strand 26 is made of a resin harder than the outer layer 24, the elongated body 12 is more flexible when the covering material 28 covering the peripheral surface of the strand 26 is thinner. become. On the other hand, in the case where the covering material 28 covering the peripheral surface of the strand 26 is made of a resin that is more flexible than the outer layer 24, the long body 12 has a smaller thickness of the covering material 28 covering the peripheral surface of the strand 26. Becomes hard.

2A to 2D, an intermediate region 31 is provided between the first region 30 and the second region 32. In the intermediate region 31, the distal end portion of the second region 32 extends from the distal end portion of the first region 30. Alternatively, the amount of the covering material 28 covering the peripheral surface of the strand 26 may be reduced. In the axial section of the long body 12, the amount of the covering material 28 covering the peripheral surface of the strand 26 in the intermediate region 31 is larger than the amount of the covering material 28 covering the peripheral surface of the strand 26 in the first region 30. Rigidity at the boundary between the first region 30 and the second region 32 of the long body 12 is configured to be less than the amount of the covering material 28 that covers the peripheral surface of the strand 26 in the second region 32. The change can be smoothed and the long body 12 can be prevented from kinking at the boundary between the first region 30 and the second region 32. For example, in the intermediate region 31, the thickness of the covering material 28 that covers the peripheral surface of the strand 26 in the intermediate region 31 is thinner than the thickness of the covering material 28 that covers the peripheral surface of the strand 26 in the first region 30; It can be configured by making it thicker than the thickness of the covering material 28 that covers the peripheral surface of the wire 26 in the second region 32.

It is preferable to apply a material having good adhesion (affinity) to the material constituting the inner layer 20 and the material constituting the outer layer 24 as the covering material 28 covering the strands 26. Thereby, the fusion | bonding of the inner layer 20, the reinforcement layer 22, and the outer layer 24 becomes strong, and the mechanical integrity of each layer can be improved. In addition, you may make it easy to adjust mutual layers by processing etc. with respect to the coating | covering material 28, and giving an unevenness | corrugation to the surrounding surface of the coating | coated material 28. FIG.

The material constituting the covering material 28 is not particularly limited, but for example, polyolefin resins such as polyethylene, polypropylene, polybutene, vinyl chloride, ethylene-vinyl acetate copolymer, or polyolefin-based elastomers thereof, fluorine-based resins. Resin or fluorine elastomer, methacrylic resin, polyphenylene oxide, modified polyphenylene ether, polyethylene terephthalate, polybutylene terephthalate, polyether ether ketone, polyamide imide, polyether imide, polyether sulfone, cyclic polyolefin, maleic anhydride elastomer, ethylene acrylic acid Copolymer, polyurethane elastomer, polyester elastomer, polyamide or polyamide elastomer, polycarbonate DOO, polyacetal, styrene resin or styrene elastomer, a thermoplastic polyimide, and the like. Of these, it is possible to use a resin imparted with adhesiveness (affinity) with polar materials (dissimilar materials such as various metals) by introducing a polar functional group into a part of the molecular structure of the nonpolar resin. Good. The covering state (wall thickness, etc.) of the covering material 28 is appropriately set depending on the rigidity design of the long body 12, the material constituting the covering material 28, the spacing between the adjacent strands 26 in the wound state, and the like. Good. For example, the thickness of the covering material 28 may be set to about 0.01 mm to 0.1 mm.

Further, when the outer layer 24 is formed by injection molding in the production of the long body 12, it is preferable that the resin material of the covering material 28 is a material harder than the resin material of the outer layer 24. If the outer diameter of the outer layer 24 (long body 12) is uniformly molded along the axial direction by injection molding, the second region 32 contains more hard resin material than the first region 30. This is because it is difficult to obtain a desired change in rigidity in the axial direction of the body 12.

The long body 12 is formed in a multilayer structure of four or more layers by forming a layer other than the reinforcing layer 22 (for example, for forming another lumen parallel to the lumen 18) between the inner layer 20 and the outer layer 24. May be.

The medical catheter 10 according to the present embodiment is basically configured as described above, and the manufacturing method thereof will be described below.

In the manufacture of the catheter 10, the laminated portion is formed in order from the inner layer as in the conventional case. That is, as shown in FIGS. 3A, 3B, and 5A, the inner layer forming step, the reinforcing layer forming step, and the outer layer forming step are sequentially performed. In the manufacturing method of this embodiment, the reinforcing layer forming step and the outer layer forming step are performed. In the meantime, as shown in FIG. 4, a reinforcing layer processing step for removing the covering material 28 is performed.

In the inner layer forming step, for example, using a precision injection molding machine (not shown), the melted resin is coated on the core wire 40 while being discharged with high accuracy through the die into the cavity where the core wire 40 (copper wire or the like) is disposed. A coating molding method can be applied. The core wire 40 to be coated forms the lumen 18 of the elongated body 12. For this reason, when the inner diameter of the lumen 18 is formed to be smaller toward the distal end of the long body 12, it is preferable to use one in which the outer diameter of the core wire 40 is gradually tapered.

Further, as another molding method of the inner layer forming step, the resin material is dissolved in an appropriate viscosity with a solvent, put in a container, the core wire 40 is immersed in the resin material in the container, and the surroundings are coated, followed by curing. You may take the method of heating for a fixed time with the heating furnace set to temperature or more.

By performing the inner layer forming step as described above, the first molded product 50 in which only the inner layer 20 is coated on the core wire 40 is constructed as shown in FIG. 3A. Next, a reinforcing layer forming step is performed on the first molded product 50. In the reinforcing layer forming step, a covered wire 42 in which the peripheral surface of the strand 26 is covered with the covering material 28 is prepared.

For this reason, before the reinforcing layer forming step, a covering step of covering the peripheral surface of the wire 26 with the covering material 28 is separately performed. The coating step can take the same molding method as the inner layer forming step. That is, in the covering step, the covering material 28 is injection-molded or coated around the strands 26 to form a covering wire 42 in which substantially the entire circumferential surface of the strands 26 is covered with the covering material 28.

In the reinforcing layer forming step, the coated wire 42 obtained in the covering step is wound around the outer side of the inner layer 20 covering the periphery of the core wire 40 using a dedicated winding device (not shown). Specifically, the bobbin is interlocked and controlled while the first molded product 50 is rotated, and the coated wire 42 wound around the bobbin is continuously sent out. The covered wire 42 is wound while being displaced in the axial direction with respect to the inner layer 20 by the displacement of the first molded product 50 along the axial direction. The winding state of the covered wire 42 (the winding method, the pitch between the adjacent covered wires 42, etc.) is set based on the physical property design of the long body 12. In particular, in the manufacturing method according to the present embodiment, since the rigidity of the long body 12 can be changed in a later reinforcing layer processing step, the coated wire 42 can be wound at equal intervals, and the reinforcing layer forming step Can be performed efficiently. By performing this reinforcing layer forming step, as shown in FIG. 3B, the second molded product 52 including the inner layer 20 and the reinforcing layer 22 formed of the coated wire 42 is constructed with respect to the core wire 40.

Next, the reinforcing layer processing step is performed on the second molded product 52 obtained in the reinforcing layer forming step. In the reinforcing layer processing step, as shown in FIG. 4, a solution 44 for dissolving the coating material 28 of the coated wire 42 is stored in the container 46, and the second molded product 52 is formed in the distal direction (the distal end of the long body 12 is configured. Dipping to the predetermined boundary.

The covered wire material 42 of the second molded product 52 is peeled off from the wire 26 by only the covering material 28 being melted by the solution 44. As a result, the coated wire 42 has a processed wire 48 having a coated portion 48a in which the coating material 28 is coated on the peripheral surface of the strand 26 and an exposed portion 48b in which the strand 26 is exposed, with the surface of the solution 44 as a base point. Migrate to That is, the second molded product 52 becomes the third molded product 54 in which the processed wire 48 is wound around the inner layer 20. The range in which the covering material 28 is peeled from the second molded product 52, that is, the axial length in which the second molded product 52 is immersed in the solution 44 is based on the rigidity (physical property) design in the axial direction of the long body 12. The time for immersing the second molded product 52 in the solution 44 may be set as appropriate based on the relationship between the material of the coating material 28 and the solution 44.

The solution 44 is made of a material that can dissolve the coating material 28 without dissolving the inner layer 20, the strand 26, and the core wire 40. The solution 44 is not particularly limited, but for example, nonpolar solvents such as toluene and benzene, dichloromethane, chloroform, ethyl acetate, butyl acetate, dimethyl ether, acetone, methyl ethyl ketone, methanol, tetrahydrofuran, dimethylformamide, dimethyl sulfoxide Polar solvents such as formic acid, acetic acid, benzoic acid, trifluoroacetic acid, p-toluenesulfonic acid, etc., organic bases such as triethylamine, pyridine, nitromethane, hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, hydrofluoric acid, etc. Examples include inorganic bases such as inorganic acids, sodium hydroxide, calcium hydroxide, and aluminum hydroxide. Moreover, you may adjust the solubility suitably by mixing these solution 44.

The third molded product 54 molded through the reinforcing layer processing step has a first region 30a and a second region 32a having different rigidity at this stage. That is, the rigidity of the covering portion 48a (the first region 30a of the third molded product 54) covered with the coating material 28 of the processed wire 48 is equal to the exposed portion 48b (the second region of the third molded product 54) where the covering material 28 is not present. Higher rigidity than 32a). The method of removing or reducing the covering material 28 on the strand 26 is not limited to immersing the second molded product 52 in the solution 44, and various methods such as scraping the covering material 28 are applied. Can do.

After forming the third molded product 54, an outer layer forming step is performed. In the outer layer forming step, for example, a resin material constituting the outer layer 24 is formed in a tube shape in advance, and the peripheral surface of the third molded product 54 is covered with the heat shrinkable tube. In this state, the heat-shrinkable tube is contracted using a heating furnace or the like, whereby the third molded product 54 and the resin constituting the outer layer 24 are heat-sealed. Thereby, as shown in FIG. 5A, the fourth molded product 56 in which the outer layer 24 covers the outer side of the reinforcing layer 22 is molded, and then the core wire 40 is removed from the fourth molded product 56 along the axial direction. The long body 12 having the inner layer 20, the reinforcing layer 22, and the outer layer 24 is molded. Further, after the third molded product 54 is molded, the outer layer 24 may be formed by injection molding using a resin material constituting the outer layer 24. By doing in this way, the magnitude | size of an outer diameter can be made the same in the full length of the elongate body 12. FIG. At this time, the resin material constituting the outer layer 24 is more flexible than the resin material constituting the covering material 28 from the viewpoint of making the second region 32 on the distal end side of the long body 12 more flexible than the first region 30. Preferably there is. Thereby, the catheter 10 makes the second region 32 on the distal end side of the long body 12 more flexible than the first region 30 while improving the adhesion between the inner layer 20 and the outer layer 24 of the reinforcing layer 22 by the covering material 28. be able to.

As shown in FIG. 5B, in the long body 12 formed by the above manufacturing method, the rigidity of the first region 30 on the proximal end side is high, and the second region 32 on the distal end side is more flexible than the first region 30. . Further, as shown in FIGS. 1B, 1C, and 5B, the first region 30 of the elongated body 12 is formed of a processed wire 48 (elementary wire 26) that is not covered with the covering material 28, and the outer diameter thereof is second. It is made thinner than the region 32. Therefore, the long body 12 is suitable for treatment or diagnosis of thin blood vessels such as peripheral blood vessels.

The formed long body 12 is completed as the catheter 10 by fixing the hub 14 to the proximal end on the first region 30 side by an appropriate joining means (caulking or bonding). In addition, the manufacturing method of the catheter 10 is not limited to said manufacturing method, You may manufacture with another manufacturing method.

For example, in the reinforcing layer forming step, the reinforcing layer 22 may be formed by using the processed wire 48 including the exposed portion 48b that is not covered with the covering material 28 and the covering portion 48a that is covered with the covering material 28. Good. That is, before the reinforcing layer forming step, a covering step for the strands 26 and a treatment step for the covering wire 42 may be performed. In this case, in the covering step, the entire outer peripheral surface of the strand 26 is covered with the covering material 28 in the same manner as the above-described covering step.

And, the treatment process is performed after the coating process. In the treatment step, the coated wire material 42 before winding is immersed in a solution 44 for dissolving the coated material 28 to melt the coated material 28 and expose the strands 26. The range in which the covering material 28 is peeled is the axial length of the first region 30 to be molded (and the axial length of the second region 32), the outer diameter of the inner layer 20, and the winding method of the processed wire 48. Based on the above, set an appropriate length.

The coated wire 42 taken out after dipping for a predetermined time shifts to a processed wire 48 that is an exposed portion 48b of the strand 26 from one end to a predetermined position and becomes a coated portion 48a of the covering 28 from the boundary to the other end. To do.

In the reinforcing layer forming process, the processed wire 48 formed through this processing process is used. In this case, the processed wire 48 is set in the winding device described above, and the processed wire 48 is wound around the first molded product 50 formed by the inner layer forming process from the tip portion. The exposed portion 48b of the processed wire 48 is first wound around the first molded product 50, and the covering portion 48a is continuously fed out after the exposed portion 48b is finished. Thereby, the reinforcing layer 22 can be easily formed. Thus, by forming the processed wire 48 before the reinforcing layer forming step, it is possible to omit the reinforcing layer processing step after the reinforcing layer forming step, and without considering the influence of the solution 44 on the inner layer 20. Thus, the molding accuracy of the long body 12 can be increased.

In the manufacturing method of providing the processed wire 48 before the reinforcing layer forming step, the processing step is not performed, and the coating process is performed on the circumferential surface of the predetermined range in the axial direction of the wire 26 (the planned formation range of the covering portion 48a). The covering material 28 may be covered. In this case, in the covering process, it is required to coat the covering material 28 on the strands 26 with high precision, so that the working time increases. However, since the subsequent reinforcing layer processing process can be omitted, the entire manufacturing of the catheter 10 is performed. As a result, shortening of the working time can be expected.

As described above, according to the medical catheter 10 and the manufacturing method thereof according to the present embodiment, the first region 30 in the longitudinal direction of the reinforcing layer 22 is covered with the strands 26 and the covering material 28 that covers the peripheral surfaces of the strands 26. Composed. Thereby, the freedom degree of the design of the rigidity of the elongate body 12 improves, and desired rigidity can be obtained. That is, in the first region 30, the rigidity of the long body 12 is not only set by changing the winding state of the wire 26 and the thickness of the outer layer 24 but also by the covering material 28 that covers the periphery of the wire 26. Can be further improved, and the range of the rigid design of the long body 12 is widened.

Further, the strand 26 coated with the coating material 28 can be easily formed by the coating process, and unnecessary portions can be easily removed by the solution 44 in the reinforcing layer processing process. For this reason, the manufacture of the medical catheter 10 is simplified, the working time can be greatly shortened, and the manufacturing cost can be reduced.

The medical catheter 10 has the second region 32 in which the covering material 28 is not covered on the peripheral surface of the strand 26, so that the medical catheter 10 differs between the first region 30 and the second region 32 of the elongated body 12. Resistance can be easily obtained. Moreover, since the second region 32 is provided on the distal end side relative to the first region 30, the distal end side of the long body 12 can be configured flexibly, and the blood vessel followability of the long body 12 is improved. be able to. In addition, since the second region 32 on the distal end side is not covered with the covering material 28, the outer diameter of the elongated body 12 can be made smaller than that in the first region 30, and even in a thin living body lumen. It can be easily applied. The long body 12 has a thickness of the covering material 28 that covers the peripheral surface of the strands 26 in the second region 32, and a thickness of the covering material 28 that covers the peripheral surface of the strands 26 in the first region 30. By reducing the thickness, the rigidity of the second region 32 on the distal end side can be reduced with respect to the first region 30 on the proximal end side.

Furthermore, the catheter 10 can change the rigidity relatively gently without providing a step on the surface, compared to a conventional long body that changes the thickness of the outer layer (see, for example, JP-A-2007-89847). . Therefore, the catheter 10 can avoid a decrease in the deliverability of the long body due to the step of the outer layer.

The medical catheter 10 according to the present invention is not limited to the above-described embodiment, and various modifications and application examples can be taken. Hereinafter, some examples of modification of the catheter 10 will be described. In the following description, the same configuration as the catheter 10 described above or a configuration having the same function is denoted by the same reference numeral, and detailed description thereof is omitted.

As shown in FIGS. 6A to 6E, the long body 12A according to the first modified example continuously changes the thickness of the covering material 28A covering the periphery of the wire 26 along the axial direction of the long body 12A. This is different from the long body 12 in that the rigidity (physical properties) is changed. That is, the long body 12A has the first region 30 (covering region) in a relatively long range in the axial direction. In the first region 30, the covering material 28A that covers the strands 26 from the base end toward the tip end is provided. It is gradually formed from thick to thin.

For this reason, the rigidity in the axial direction of the long body 12A is set so as to be gradually lowered from the proximal end toward the distal end. The change in the thickness of the covering material 28A can be easily realized by adjusting the immersion time in which the second molded product 52 is immersed in the solution 44 in the above-described reinforcing layer processing step (see also FIG. 4). Specifically, the second molded product 52 is lowered along the axial direction with respect to the solution 44 stored in the container 46 and inserted from the tip side. And if this 2nd molded product 52 is raised slowly, the axial direction of the 2nd molded product 52 will become soaking time with respect to the solution 44 from the base end side toward the front end side. As a result, the coating material 28 is dissolved in the solution 44 as it approaches the front end side, and the thickness of the coating material 28 around which the inner layer 20 is wound is gradually reduced in the third molded product 54 to be molded.

As described above, by smoothly changing the rigidity of the long body 12A, kinks are less likely to occur as compared to a long body whose rigidity changes suddenly in the axial direction. Therefore, when using this catheter 10, the surgeon can smoothly advance the long body 12 </ b> A within the blood vessel and can perform the procedure well.

As shown in FIGS. 7A to 7C, the long body 12B according to the second modified example is long in that it has a plurality of coating materials covering the periphery of the strands 26 on the first region 30 (covering region). Different from the body 12. For example, in the first region 30 of the long body 12B, the one-layer region 34 that covers the strand 26 with one coating material 29A and the two

coating materials

29A and 29B are stacked to cover the peripheral surface of the strand 26. Two-layer regions 36 are provided. Accordingly, the rigidity of the one-layer region 34 is higher than that of the second region 32 that is not covered with the covering

materials

29A and 29B, and the rigidity of the two-layer region 36 is higher than that of the first-layer region 34. A long body 12B having a change can be formed.

The multiple-

layer coating materials

29A and 29B can be easily formed by performing coating of the coating material 28 a plurality of times (the number of layers) in the coating process. The multiple layers of the covering

materials

29A and 29B may be made of the same material or different materials. When a plurality of layers are formed with

different coating materials

29A and 29B, the layers are first immersed in a solution 44a that dissolves the outer coating material 29B, and then immersed in a solution 44b that dissolves the inner coating material 29A (FIG. 4). reference). At this time, the axial length in which the second molded product 52 is immersed is appropriately changed for each coating material 28. Thus, the long body 12B having the two-layer region 36, the first-layer region 34, and the second region 32 from the proximal end side toward the distal end side can be formed.

In the long body 12B according to the second modification, the function of the covering

materials

29A and 29B can be easily changed by laminating a plurality of covering

materials

29A and 29B. It becomes possible to design. In the present embodiment, the first modified example, or the second modified example, the rigidity of the

long bodies

12, 12A, 12B is set so as to decrease toward the distal end side, but the rigidity in the axial direction is arbitrarily set. You can do it. For example, there may be a portion where the rigidity of the long body is lowest in an intermediate portion in the axial direction of the long body 12 (between the distal end side and the proximal end side).

As shown in FIGS. 8A to 8C, the long body 12C according to the third modification is different from the long body 12 in that the strands 26A (processed wire rods 49) constituting the reinforcing layer 22A are braided into a mesh shape. . The element wire 26A is configured by a flat wire having a rectangular cross section. Even if the strands 26A are formed as flat wires in this way, the covering material 28 can be satisfactorily covered by the covering step.

Therefore, by immersing the mesh-like processed wire 49 in the solution 44 in a state of being surrounded by the outer peripheral surface of the inner layer 20, the length of the proximal end side is high and the distal end side rigidity is low as in the catheter 10. The scale 12C can be formed.

In short, the cross-sectional shape of the

strands

26 and 26A covered with the covering material 28, or the winding state and the braided state of the

strands

26 and 26A constituting the reinforcing

layers

22 and 22A are not particularly limited. Further, the covering material 28 may not be covered over the entire circumference in the circumferential direction of the strand 26 in the formation state of the catheter 10. For example, according to the rigidity desired by the catheter 10, the structure which covered only a part of the circumferential direction of the strand 26, and peeled the other part may be sufficient.

In the above description, the present invention has been described with reference to preferred embodiments. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention. Yes.

Claims

An inner layer (20);
A reinforcing layer (22, 22A) covering the outside of the inner layer (20);
An elongate body (12, 12A-12C) having a lumen (18) including an outer layer (24) covering the outside of the reinforcing layer (22, 22A),
The reinforcing layer (22, 22A) includes a wire (26, 26A) wound or braided on the inner layer (20),
The elongated body (12, 12A-12C) has a first region (30) and a second region (32) along the longitudinal direction of the elongated body (12, 12A-12C),
In the first region (30), a covering material (28, 28A, 29A, 29B) formed separately from the inner layer (20) and the outer layer (24) and covering the peripheral surface of the strands (26, 26A). Is provided,
In the second region (32), the covering material (28, 28A, 29A, 29B) is not covered on the peripheral surface of the strand (26, 26A), or the element in the first region (30). The coating material (28, 28A, 29A, 29B) having a smaller thickness than the coating material (28, 28A, 29A, 29B) provided on the peripheral surface of the wire (26, 26A) is provided. A medical catheter (10) characterized.
The medical catheter (10) according to claim 1,
Said 2nd area | region (32) is provided in the front end side rather than said 1st area | region (30). The medical catheter (10) characterized by the above-mentioned.
The medical catheter (10) according to claim 1,
The elongated body (12) has an intermediate region (31) between the first region (30) and the second region (32),
In the intermediate region (31), the covering material that covers the peripheral surface of the strand (26, 26A) from the distal end portion of the first region (30) toward the proximal end portion of the second region (32). A medical catheter (10) characterized in that the amount of (28, 28A, 29A, 29B) is reduced.
The medical catheter (10) according to claim 1,
The medical catheter (10), wherein a thickness of the covering material (28A) continuously changes along the longitudinal direction of the reinforcing layer (22, 22A).
The medical catheter (10) according to claim 4,
The medical catheter (10), wherein the thickness of the covering material (28A) is reduced toward the distal end side of the reinforcing layer (22, 22A).
The medical catheter (10) according to claim 1,
The medical catheter (10), wherein the first region (30) has a portion where a plurality of the covering materials (29A, 29B) are laminated on the strand (26).
An inner layer forming step of forming the inner layer (20) by covering the periphery of the core wire (40) in the circumferential direction;
It has a 1st field (30) by enclosing the outside of the inner layer (20) with the covering wire (42) which covered the peripheral surface of the strand (26, 26A) with the covering (28, 28A, 29A, 29B). A reinforcing layer forming step of forming the reinforcing layer (22, 22A);
After the reinforcing layer forming step, a part of the covering material (28, 28A, 29A, 29B) of the covering wire (42) is removed or reduced to reduce the first region (22, 22A) to the first region (22, 22A). 30) a reinforcing layer treatment step for forming a second region (32) different from 30),
An outer layer forming step of forming an outer layer (24) covering the outside of the reinforcing layer (22, 22A) after the reinforcing layer treatment step. A method for producing a medical catheter (10), comprising:
In the manufacturing method of the medical catheter (10) of Claim 7,
In the reinforcing layer treatment step, the molded product (52) on which the reinforcing layer (22, 22A) is formed is dissolved in a solution (44, 44a, 44b) that dissolves the covering material (28, 28A, 29A, 29B). The method for producing a medical catheter (10), characterized in that the immersion is performed in the axial direction with a different immersion time.