Catheter

Abstract

To provide a catheter whose end part is soft and which is excellent in torque transmission property.SOLUTION: A catheter 1 includes a hollow-shaped catheter body 11 having a lumen 11h going from an end through to a base end and a coil body 21 provided to cover an outer periphery of the catheter body 11. The catheter body 11 has an end side cylindrical part 11A and a base end side cylindrical part 11B arranged on the base end side of the end side cylindrical part 11A. Rigidity of the end side cylindrical part 11A is smaller than that of the base end side cylindrical part 11B. The coil body 21 is fixed to the end side cylindrical part 11A at a first fixing part 311 and fixed to the base end side cylindrical part 11B at a second fixing part 312.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a catheter. [Background technology]

[0002] For example, when a lesion in a blood vessel is treated with a catheter, a guidewire is inserted to the lesion prior to the catheter, and the catheter is then delivered to the lesion along the guidewire.

[0003] As such a catheter, for example, a coiled tube having a configuration in which a coil is attached to the outer periphery of the tube is known (Patent Document 1), and this catheter is made of a resin tube over the entire longitudinal direction. Therefore, the entire catheter has high flexibility, and the catheter can be smoothly advanced and retreated while following the curved blood vessel along the guidewire. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 7-136279 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when performing procedures using the conventional catheters described above, although the catheter itself is flexible and has high tracking ability, it is difficult to deliver the catheter to the lesion site alone or to rotate it alone, which requires a complicated procedure using a guidewire in order to guide the catheter to the lesion site.

[0006] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a catheter having a flexible tip portion and excellent torque transmission properties. [Means for solving the problem]

[0007] Some aspects of the present disclosure include: (1) A hollow catheter body having an internal lumen extending from the distal end to the proximal end; a coil body provided to cover an outer periphery of the catheter body, the catheter body has a distal tubular portion and a proximal tubular portion disposed on the proximal side of the distal tubular portion, the rigidity of the distal end side tubular portion is smaller than the rigidity of the proximal end side tubular portion, a catheter, wherein the coil body is fixed to the distal end tubular portion by a first fixing portion and is fixed to the proximal end tubular portion by a second fixing portion; (2) The catheter according to (1), wherein the first fixing portion and the second fixing portion are disposed independently of each other, and the coil body and the catheter main body are not fixed to each other in a region between the first fixing portion and the second fixing portion. (3) The catheter according to (1) or (2), wherein the base end side tubular portion includes a metal member. (4) A distal tip is provided on the distal end side of the distal end side tubular portion, the distal tip has an inner lumen extending from the distal end to the proximal end and communicating with an inner lumen of the catheter body; The catheter according to any one of (1) to (3), wherein the distal end side tubular portion and the coil body are fixed to each other via the distal tip; and (5) The catheter according to any one of (1) to (4), wherein an inner layer made of a fluororesin and / or a polyamide resin is provided on the inner periphery of the catheter body.

[0008] In this specification, the term "tip side" refers to the direction along the longitudinal direction of the catheter body, in which the catheter advances toward the treatment site. The term "base side" refers to the direction along the longitudinal direction of the catheter body, in the opposite direction to the tip side. Additionally, the term "tip" refers to the tip end of any member or site, and the term "base end" refers to the base end of any member or site. The term "longitudinal direction" refers to the direction along the longitudinal direction of the catheter body, unless otherwise specified. Effect of the Invention

[0009] The present invention can provide a catheter having a flexible tip and excellent torque transmission properties. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic side view showing a first embodiment. [Diagram 2] FIG. 2 is a schematic enlarged longitudinal sectional view showing a part of FIG. [Diagram 3] FIG. 4 is a schematic enlarged longitudinal sectional view showing a part of the second embodiment. [Figure 4] FIG. 11 is a partially enlarged schematic vertical sectional view showing a modified example. [Diagram 5] FIG. 11 is a partially enlarged schematic vertical sectional view showing a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The catheter of the present disclosure comprises a hollow catheter body having an inner lumen extending from the tip to the base end, and a coil body arranged to cover the outer periphery of the catheter body, wherein the catheter body has a tip side tubular section and a base side tubular section arranged on the base end side of the tip side tubular section, the rigidity of the tip side tubular section being smaller than the rigidity of the base side tubular section, and the coil body being fixed to the tip side tubular section by a first fixing section and to the base side tubular section by a second fixing section.

[0012] Hereinafter, the first and second embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the embodiments shown in the drawings. The dimensions of each part shown in the drawings are shown to facilitate understanding of the implementation content, and do not necessarily correspond to the actual dimensions. In each drawing, the left side of the drawing is the tip side (distal side) that is inserted deeper into the body, and the right side is the base side (proximal side, hand side) that is operated by a technician such as a doctor.

[0013] [First embodiment] 1 is a schematic side view showing the first embodiment. As shown in FIG. 1, a catheter 1 is generally composed of a catheter body 11, a coil body 21, and a connector 41.

[0014] The catheter body 11 is a hollow member having an opening 11a at the tip and a lumen 11h that passes through from the tip to the base end. The catheter body 11 has a tip side tubular portion 11A and a base side tubular portion 11B.

[0015] The tip side tubular portion 11A is a tubular portion located at the tip portion of the catheter main body 11. A tip side portion of the lumen 11h constitutes the lumen of the tip side tubular portion 11A.

[0016] The base end side tubular portion 11B is a tubular portion disposed on the base end side of the tip end side tubular portion 11A. The base end side portion of the inner cavity 11h constitutes the inner cavity of the base end side tubular portion 11B.

[0017] The catheter 1 of the present disclosure is configured so that the rigidity of the distal end tubular portion 11A is smaller than that of the proximal end tubular portion 11B. Specifically, the catheter main body 11 may be configured so that the distal end tubular portion 11A is configured from a single homogeneous tubular member, and the proximal end tubular portion 11B is configured from homogeneous double tubular members arranged concentrically and in contact with each other. The catheter main body 11 of this embodiment is configured from a member (hereinafter also referred to as the "first tube 11T1") in which the member constituting the distal end tubular portion 11A and the member arranged on the inside of the proximal end tubular portion 11B are integrally formed, and a member (hereinafter also referred to as the "second tube 11T2") arranged on the outside of the proximal end tubular portion 11B.

[0018] The material forming the distal end side tubular portion 11A and the proximal end side tubular portion 11B is not particularly limited as long as the rigidity of the distal end side tubular portion 11A is smaller than the rigidity of the proximal end side tubular portion 11B, but it is preferable that the proximal end side tubular portion 11B includes a metal member. By including a metal member in the proximal end side tubular portion 11B, the rigidity of the proximal end side tubular portion 11B can be easily adjusted by adjusting the metal material used and its arrangement. In addition, by including a metal member in the proximal end side tubular portion 11B, the torque transmission of the catheter 1 is further improved. The above-mentioned metal member may be, for example, a tube-shaped member, a linear or ribbon-shaped member wound along the longitudinal axis direction, or a member obtained by subjecting a tube-shaped member to slit processing.

[0019] Examples of materials for forming the tip side tubular portion 11A include resin materials such as thermoplastic polyurethane (TPU), polyamide (PA), polycarbonate (PC), polyethylene (PE), polyimide (PI), polyamideimide (PAI), polytetrafluoroethylene (PTFE), and tetrafluoroethylene-perfluoroalkoxyethylene copolymer (PFA).

[0020] The material for forming the base end tubular portion 11B may be the same resin material as that for forming the tip end tubular portion 11A described above; metal materials such as stainless steel (e.g., SUS304) and superelastic alloys (e.g., Ni-Ti alloys); or combinations of these materials.

[0021] When the catheter main body 11 is composed of two or more members made of different materials, the members may be joined together by, for example, heat welding, glued with an adhesive, brazed with a wax material, or mechanically fixed by caulking, etc. Note that, as the adhesive and wax material, for example, the same adhesives and wax materials as those used for the first fixing part 311 and the second fixing part 312 described later can be used.

[0022] In this embodiment, the first tube 11T1 is made of a resin material, and the second tube 11T2 is made of a metal material. The first tube 11T1 and the second tube 11T2 are joined to the second tube 11T2 by heat welding the resin material constituting the first tube 11T1.

[0023] The coil body 21 is a member provided so as to cover the outer periphery of the catheter main body 11. The coil body 21 can be formed, for example, by spirally winding one or more solid wires, or one or more twisted wires, around the outer periphery of the distal end (tip-side tubular portion 11A) of the catheter main body 11. Note that a solid wire refers to one single wire, and a twisted wire refers to a bundle of wires formed by twisting multiple single wires together in advance.

[0024] Examples of materials that can be used to form the coil body 21 include stainless steel such as SUS316; superelastic alloys such as Ni-Ti alloys; radiopaque metal materials such as platinum and tungsten; and combinations of these materials.

[0025] In the catheter 1, the coil body 21 is fixed to the catheter body 11 at a first fixing portion 311 and a second fixing portion 312.

[0026] The first fixed portion 311 is a portion fixed to the tip side tubular portion 11A of the coil body 21. In this embodiment, the first fixed portion 311 is located on the tip outer periphery of the tip side tubular portion 11A (the tip outer periphery of the first tube 11T1).

[0027] The second fixed portion 312 is a portion fixed to the base end side tubular portion 11B of the coil body 21. In this embodiment, the second fixed portion 312 is located on the tip of the base end side tubular portion 11B (the tip of the second tube 11T2).

[0028] In the catheter 1, the first fixing part 311 and the second fixing part 312 are arranged independently of each other, and in a region R between the first fixing part 311 and the second fixing part 312, the coil body 21 and the catheter main body 11 are not fixed to each other. That is, the first fixing part 311 and the second fixing part 312 provided along the longitudinal direction of the catheter main body 11 are arranged with a gap therebetween, and in the region R between the first fixing part 311 and the second fixing part 312, the coil body 21 and the catheter main body 11 are not constrained to each other (in the region R, the coil body 21 and the catheter main body 11 can move relatively).

[0029] There is no particular limitation on the method for fixing the coil body 21 and the catheter main body 11. Examples of the fixing method include a method of heating and melting a base material to weld the coil body 21 and the catheter main body 11, a brazing method using a brazing material, and a bonding method using an adhesive.

[0030] Examples of the brazing material include metal brazing materials such as Sn-Pb alloys, Pb-Ag alloys, Sn-Ag alloys, and Au-Sn alloys. Examples of the adhesive include epoxy adhesives and cyanoacrylate adhesives.

[0031] In this embodiment, the coil body 21 and the catheter main body 11 are fixed with an adhesive at a first fixing portion 311 and a second fixing portion 312. Specifically, the tip of the coil body 21 is fixed to the tip outer periphery of the tip side tubular portion 11A (the tip outer periphery of the first tube 11T1) at the first fixing portion 311 using an adhesive B. Also, the base end of the coil body 21 is fixed to the tip of the base side tubular portion 11B (the tip of the second tube 11T2) at the second fixing portion 312 using an adhesive B.

[0032] The connector 41 is a member with which the operator operates the catheter 1. The connector 41 is connected to the base end of the catheter body 11. The connector 41 has, for example, an opening 41a at the base end and an inner lumen 41h that communicates with the inner lumen 11h of the catheter body 11. The shape of the connector 41 is not particularly limited as long as it does not impair the effects of the present invention, and can be formed, for example, into a shape that is easy for the operator to operate.

[0033] In the catheter 1, the lumen L1 is formed by the inner lumens 11h and 41h.

[0034] Next, two examples of how to use the catheter 1 will be described. The first example is a procedure in which the catheter 1 is used together with a guidewire. First, prior to the insertion of the catheter 1, a guidewire (not shown) is inserted into a blood vessel from its tip, and the guidewire exposed outside the body is manipulated to advance its tip to a lesion (e.g., a site where a thrombus has formed).

[0035] Next, the base end of the guidewire (the end on the proximal side exposed outside the body) is inserted into the lumen L1 of the catheter 1 from the opening 11a. Next, while operating the connector 41, the tip of the catheter 1 is pushed along the guidewire to the lesion. Next, after the guidewire is removed from the body, the catheter 1 is used to perform a predetermined procedure (for example, a procedure for injecting a drug through the lumen L1, removing a blood clot, or inserting a long medical device through the lumen L1). At this time, since the catheter 1 has a flexible tip and excellent torque transmission, the tip of the catheter 1 is rotated or advanced or retreated by rotating or pushing and pulling the connector 41, and the procedure can be performed quickly while adjusting the position of the tip of the catheter in the blood vessel without reinserting the guidewire.

[0036] The second mode of use is a procedure in which the catheter 1 is delivered to the lesion by itself without using a guidewire. In this procedure, the catheter 1 is inserted into a blood vessel from its tip, and the tip of the catheter 1 is pushed to the lesion while pushing in the connector 41. A predetermined procedure is then performed using the catheter 1. At that time, since the catheter 1 has a flexible tip and excellent torque transmission ability, the tip of the catheter 1 rotates or advances and retreats by rotating or pushing and pulling the connector 41, and treatment can be performed quickly while adjusting the position of the tip in the blood vessel.

[0037] As described above, the catheter 1 has the above-mentioned configuration, and therefore has a flexible distal end, and is excellent in torque transmission, since the torque transmitted through the highly rigid proximal tubular portion 11B can be effectively transmitted to the less rigid distal tubular portion 11A via the second fixing portion 312 and the first fixing portion 311 of the coil body 21. As a result, the catheter 1 can rotate and advance / retract its distal end independently without using a guidewire, for example, allowing the procedure to be performed quickly and with greater latitude in the procedure.

[0038] [Second embodiment] Fig. 3 is a schematic longitudinal sectional view showing an enlarged portion of the second embodiment. As shown in Fig. 3, the catheter 2 is generally composed of a catheter body 12, a coil body 21, a distal tip 52, and a connector 41 (not shown). The catheter 2 differs from the first embodiment in that it includes the catheter body 12 and the distal tip 52. Since the coil body 21 and the connector 41 are the same as those in the first embodiment, the same parts are denoted by the same reference numerals and detailed description thereof will be omitted. Furthermore, the configuration of the catheter body 12 other than the configuration of the catheter body 12 described below and the mode of use of the catheter 2 are the same as those in the first embodiment.

[0039] The catheter body 12 is a hollow member having a lumen 12h that passes through from the tip to the base end. The catheter body 12 has a tip side tubular portion 12A and a base side tubular portion 12B.

[0040] The tip side tubular section 12A is a section located at the tip end of the catheter main body 12. The base side tubular section 12B is disposed on the base end side of the tip side tubular section 12A. The rigidity of the tip side tubular section 12A is configured to be smaller than the rigidity of the base side tubular section 12B.

[0041] The catheter body 12 of this embodiment is composed of a member (hereinafter also referred to as the "first tube 12T1") that is integrally formed with a member constituting the tip side tubular portion 12A and a member arranged on the inside of the base side tubular portion 12B, and a member (hereinafter also referred to as the "second tube 12T2") that is arranged on the outside of the base side tubular portion 12B.

[0042] An inner layer 12n made of fluororesin and / or polyamide resin is provided on the inner periphery of the catheter main body 12. Specifically, for example, a first tube 12T1 having the inner layer 12n may be disposed from the tip end to the base end of the catheter main body 12.

[0043] The inner layer 12n may be disposed continuously from the distal end to the proximal end of the catheter body 12, or may be disposed separately in a plurality of independent portions in the longitudinal direction. The inner layer 12n may be made of either a fluororesin or a polyamide resin, and the fluororesin and the polyamide resin may be disposed separately in a plurality of portions in the longitudinal direction.

[0044] A braided body 12b is embedded in the catheter main body 12 so as to cover the outer periphery of the inner layer 12n. Specifically, the braided body 12b is formed, for example, by weaving wires into a mesh shape, and can be embedded in the first tube 12T1. The catheter main body 12 has the braided body 12b, which allows the catheter main body 12 to be reinforced while maintaining the flexibility of the tip side tubular section 12A.

[0045] Examples of materials that can be used to form the braid 12b include stainless steel such as SUS304; superelastic alloys such as Ni-Ti alloys; and radiopaque metals such as platinum and tungsten.

[0046] The distal tip 52 is a member provided on the distal end side of the distal tubular portion 12A. The distal tip 52 has an opening 52a at its distal end, and has a lumen 52h that penetrates from the distal end to the proximal end and communicates with the lumen 12h of the catheter body 12. The distal tip 52 may be formed in a shape that tapers toward the distal end, such as a hemispherical shape that protrudes toward the distal end, so that the catheter 2 can easily proceed inside the body cavity.

[0047] In this embodiment, the distal end tubular section 12A and the coil body 21 are fixed to each other via the distal end tip 52. Specifically, for example, in the first fixing section 321, the coil body 21 is not directly fixed to the catheter body 12 (specifically, the distal end tubular section 12A), but is fixed to the distal end tip 52.

[0048] Examples of materials for forming the tip 52 include metal materials such as the above-mentioned brazing material, and resin materials such as polyurethane and polyurethane elastomer.

[0049] Methods for fixing the distal tip 52 to the coil body 21 and the catheter body 12 include, for example, brazing the distal end of the coil body 21 or the distal end of the catheter body 12 to the distal tip 52 made of a wax material, welding or embedding them in the distal tip 52 made of a resin material, or bonding them with an adhesive.

[0050] In the catheter 2, the lumen L2 is formed by the lumen 52h, the lumen 12h, and the lumen 41h.

[0051] As described above, in the catheter 2, the distal tubular section 12A and the coil body 21 are fixed to each other via the distal tip 52. Therefore, by appropriately selecting the shape of the distal tip 52, it is possible to reduce resistance when the catheter 2 advances and suppress damage to tissue, for example.

[0052] As described above, the catheter 2 has an inner layer 12n made of fluororesin and / or polyamide resin provided on the inner periphery of the catheter body 12. This can improve the sliding properties with a medical device inserted into the lumen 12h of the catheter body 12 and reduce frictional resistance with a medicinal solution introduced through the lumen 12h and with obstructing matter retrieved through the lumen 12h, allowing procedures to be performed smoothly.

[0053] The present disclosure is not limited to the configurations of the above-described embodiments, but is intended to include all modifications within the scope of the claims and meaning equivalent to the scope of the claims. A part of the configurations of the above-described embodiments may be deleted or replaced with another configuration, or another configuration may be added to the configurations of the above-described embodiments.

[0054] 4, the tip of base-side tubular portion 13B may be formed with inclined surface 13c facing radially outward, and the base end of coil body 21 may be disposed so as to rest on inclined surface 13c. This allows easy and reliable positioning of the base end of coil body 21 and the tip of base-side tubular portion 13B, enabling mass production of catheters with little variation and high positional accuracy.

[0055] 5, the base end of the coil body 21 may be disposed so as to be in contact with the outer circumferential surface 14s of the tip end of the base-end tubular portion 14B. This makes it possible to easily increase the length of contact between the coil body 21 and the base-end tubular portion 14B in the longitudinal direction, and, for example, to further increase the joint strength between the coil body 21 and the base-end tubular portion 14B.

[0056] In the above-described embodiment, the catheters 1 and 2 are described in which the coil body 21 and the distal end tubular portion 11A, 12A are spaced apart. However, the coil body and the distal end tubular portion may be arranged in contact with each other so as to be separable in the region R between the first fixing portion and the second fixing portion.

[0057] In the above-described embodiment, the catheters 1 and 2 are described in which the distal end tubular portion 11A, 12A and the proximal end tubular portion 11B, 12B are formed using the first tube 11T1, 12T1 and the second tube 11T2, 12T2. However, the distal end tubular portion and the proximal end tubular portion may be integrally formed, or the distal end tubular portion and the proximal end tubular portion may be integrally formed, and the proximal end of the distal end tubular portion and the distal end of the proximal end tubular portion may be joined.

[0058] In the above-mentioned second embodiment, the catheter 2 has the distal tip 52, the inner layer 12n, and the braided body 12b. However, the catheter may not have all of these (such as the catheter 1 of the first embodiment), or may have at least one of these. [Explanation of symbols]

[0059] 1,2 Catheter 11, 12, 13, 14 Catheter body 11A,12A Tip side cylindrical part 11B, 12B, 13B, 14B Base end cylindrical part 11h,12h lumen 12n inner layer 21 Coil body 311,321,331,341 1st fixed part 312,322,332,342 2nd fixed part 52 Tip 52h lumen R region

Claims

1. a hollow catheter body having a lumen extending from the distal end to the proximal end; a coil body provided to cover the outer periphery of the catheter body, the catheter body has a distal tubular portion and a proximal tubular portion disposed on the proximal side of the distal tubular portion, the rigidity of the distal end side tubular portion is lower than the rigidity of the proximal end side tubular portion, A catheter characterized in that the coil body is fixed to the distal tubular portion by a first fixing portion and is fixed to the proximal tubular portion by a second fixing portion.

2. 2. The catheter according to claim 1, wherein the first fixing portion and the second fixing portion are arranged independently of each other, and the coil body and the catheter main body are not fixed to each other in the region between the first fixing portion and the second fixing portion.

3. The catheter according to claim 1 or 2, wherein the proximal cylindrical portion includes a metal member.

4. A distal tip is provided at the distal end of the distal end cylindrical portion, the distal tip has a lumen that penetrates from the distal end to the proximal end and communicates with the lumen of the catheter body; 3. The catheter according to claim 1, wherein the distal cylindrical portion and the coil body are fixed to each other via the distal tip.

5. 3. The catheter according to claim 1, wherein an inner layer made of fluororesin and / or polyamide resin is provided on the inner periphery of the catheter body.

Images