catheter

Abstract

This prevents the reinforcing material from being exposed to the outside when the catheter breaks. [Solution] The catheter comprises a first tube, a tip, and a second tube. The first tube has a reinforced section in which a reinforcing body is embedded. The tip is located more distal to the first tube. The second tube is joined to the first tube and the tip. At least one of the tensile strength of the second tube and the joint strength between the second tube and the first tube is less than the tensile strength of the reinforced section.

Description

Technical Field

[0001] The technology disclosed in this specification relates to a catheter.

Background Art

[0002] A catheter is used, for example, when treating a lesion in a living body lumen such as a blood vessel. The catheter has a tube. A reinforcing member such as a coil is embedded in the tube (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a known catheter, if a tensile force acts on the tip of the catheter and causes it to break, there is a risk that the reinforcing member will be exposed to the outside.

[0005] This specification discloses a technology capable of solving the above-described problems.

Means for Solving the Problems

[0006] The technology disclosed in this specification can be realized, for example, in the following forms.

[0007] The catheter disclosed in this specification includes a first tube, a tip chip, and a second tube. The first tube has a reinforcing portion in which a reinforcing member is embedded. The tip chip is located on the tip side of the first tube. The second tube is joined to the first tube and the tip chip. At least one of the breaking strength of the second tube and the joining strength between the second tube and the first tube is smaller than the breaking strength of the reinforcing portion.

Brief Description of the Drawings

[0008] [Figure 1] Side view of the catheter in this embodiment [Figure 2] Diagram showing a longitudinal section of the catheter tip. [Figure 3] This is an explanatory diagram showing a cross-section of the catheter shaft at position III-III in Figure 2. [Modes for carrying out the invention]

[0009] (Embodiment) (Configuration of catheter 10) Figure 1 is a side view of the catheter 10 in this embodiment. Figure 2 is an explanatory diagram showing a longitudinal section (YZ section) of the tip of the catheter 10. Figure 3 is an explanatory diagram showing a cross-section (XY section) of the shaft portion 20 of the catheter 10 at position III-III in Figure 2.

[0010] The positive Z-axis side of the catheter 10 is the distal end (tip) that is inserted into the body. The negative Z-axis side of the catheter 10 is the proximal end (proximal) that is manipulated by the operator. In the catheter 10 and its components, "tip" means the tip end, "tip portion" means the tip and its vicinity, "proximal end" means the proximal end, and "proximal end portion" means the proximal end and its vicinity. In the catheter 10 and its components, "longitudinal section" means a section parallel to the central axis Ax of the catheter 10, and "transverse section" means a section perpendicular to the central axis Ax.

[0011] Catheter 10 is a medical device. Catheter 10 is used, for example, to treat lesions in biological lumens. Biological lumens include blood vessels, the digestive tract, ureters, organs, and bile ducts.

[0012] The catheter 10 has a shaft portion 20 and a connector 30. The connector 30 is connected to the proximal end of the shaft portion 20.

[0013] The shaft portion 20 is a long, rectangular member. The shaft portion 20 has a first lumen 11L and a second lumen 12L that extend in the longitudinal direction of the shaft portion 20. For example, other medical devices can be inserted into the first lumen 11L and the second lumen 12L. The tip of the first lumen 11L opens at the tip of the shaft portion 20, and the base end of the first lumen 11L opens in a hole 22 formed in the middle portion of the shaft portion 20 between the tip and the base end. The tip of the second lumen 12L opens at the tip of the shaft portion 20, and the base end of the second lumen 12L opens at the base end of the shaft portion 20.

[0014] The shaft portion 20 includes a tip 150, a first tube 110, a second tube 120, a third tube 130, an outer tube 140, a core wire 160, and a marker 170.

[0015] The tip 150 is a tubular member having a through hole 156 that extends in the longitudinal direction of the shaft portion 20. The tip 150 is positioned at the very front of the shaft portion 20. The through hole 156 of the tip 150 forms the tip of the first lumen 11L. The tip 150 is made of, for example, resin or metal.

[0016] The third tube 130 is a tubular member having a through hole 136 that extends in the longitudinal direction of the shaft portion 20. The tip 130d of the third tube 130 is located closer to the base end than the base end of the tip 150. The base end 130p of the third tube 130 is approximately the same as the base end of the shaft portion 20. The through hole 136 of the third tube 130 forms the second lumen 12L.

[0017] The outer edge shape of the cross-section of the third tube 130 is, for example, approximately circular. The outer edge shape of the cross-section may differ for each part of the third tube 130. The third tube 130 is formed of, for example, a resin material. The third tube 130 may be formed of the same material throughout. The third tube 130 may be formed of different materials for each part.

[0018] The third tube 130 has a reinforcement 134 embedded therein. The reinforcement 134 is, for example, a coil body or a braided body (blade). The reinforcement 134 suppresses, for example, the collapse of the third tube 130. The reinforcement 134 is formed of, for example, a metal material. Examples of the material forming the reinforcement 134 include tungsten, stainless steel (SUS302, SUS304, SUS316, etc.). In the present embodiment, the reinforcement 134 is arranged over the entire length of the third tube 130.

[0019] The first tube 110 is a tubular member in which a through hole 116 extending in the longitudinal direction of the shaft portion 20 is formed. The tip 110d of the first tube 110 is located on the proximal side of the proximal end of the tip chip 150. The proximal end 110p of the first tube 110 is substantially the same as the position of the hole 22 formed in the middle portion of the shaft portion 20\. The through hole 116 of the first tube 110 forms the proximal end portion of the first lumen 11L. The shape of the outer edge of the cross section of the first tube 110 is, for example, substantially circular. The shape of the outer edge of the cross section may be different for each part of the first tube 110.

[0020] The first tube 110 is formed of, for example, a resin material. The first tube 110 may be formed of the same material throughout. The first tube 110 may be formed of different materials for each part. The first tube 110 may have, for example, an inner layer formed of polytetrafluoroethylene (PTFE) and an outer layer formed of, for example, a polyamide resin.

[0021] The first tube 110 has a reinforced portion 112 and an unreinforced portion 111. A reinforcing body 114 is embedded in the reinforced portion 112. The reinforcing body 114 is, for example, a coil or a braid. The reinforcing body 114 suppresses, for example, the crushing of the first tube 110. The reinforcing body 114 is formed of, for example, a metal material. Examples of materials for forming the reinforcing body 114 include tungsten and stainless steel (SUS302, SUS304, SUS316, etc.). In this embodiment, the reinforcing body 114 is arranged along the entire length of the first tube 110, excluding a portion at the tip (i.e., the unreinforced portion 111). A protective layer may be additionally arranged in the radially outer region of the first tube 110 where the tip of the reinforcing body 114 is located, to suppress the exposure of the reinforcing body 114 to the outside. The protective layer is formed of, for example, a resin material such as PET (polyethylene terephthalate).

[0022] The unreinforced portion 111 of the first tube 110 is located on the tip side of the reinforced portion 112. No reinforcing material is placed in the unreinforced portion 111.

[0023] The second tube 120 is a tubular member in which a through hole 126 extending in the longitudinal direction of the shaft portion 20 is formed. The second tube 120 is joined to the tip chip 150 and the first tube 110. More specifically, the tip portion 121 of the second tube 120 is inserted into the through hole 156 of the tip chip 150. That is, the tip 120d of the second tube 120 is located on the tip side of the base end of the tip chip 150. The base end portion 123 of the second tube 120 covers the tip end portion of the first tube 110 from the outer peripheral side. In the present embodiment, the base end portion 123 of the second tube 120 covers substantially the entire non-reinforcement portion 111 of the first tube 110 and does not cover the reinforcement portion 112. That is, the base end 120p of the second tube 120 is substantially the same as the position of the boundary between the non-reinforcement portion 111 and the reinforcement portion 112. The base end portion 123 of the second tube 120 is joined to the non-reinforcement portion 111 of the first tube 110 by, for example, welding or adhesion. The tip portion 121 of the second tube 120 is joined to the base end portion of the tip chip 150 by, for example, welding or adhesion. The intermediate portion 122 connecting the tip portion 121 and the base end portion 123 in the second tube 120 is located on the base end side of the base end of the tip chip 150 and on the tip side of the tip 110d of the first tube 110. No reinforcing body is arranged in the second tube 120.

[0024] The through hole 126 of the second tube 120 is connected to the through hole 156 of the tip chip 150 and the through hole 116 of the first tube 110, and forms the intermediate portion of the first lumen 11L. The shape of the outer edge of the cross section of the second tube 120 is, for example, substantially circular. The shape of the outer edge of the cross section may be different for each part of the second tube 120.

[0025] The second tube 120 is formed of, for example, a resin material. The second tube 120 may be formed of the same material throughout. The second tube 120 may be formed of different materials for each part. The second tube 120 may be formed of, for example, a polyethylene resin.

[0026] In this embodiment, at least one of the breaking strength of the second tube 120 and the joint strength between the second tube 120 and the first tube 110 is less than the breaking strength of the reinforcing portion 112 of the first tube 110. Both the breaking strength of the second tube 120 and the joint strength between the second tube 120 and the first tube 110 may be less than the breaking strength of the reinforcing portion 112 of the first tube 110. Only one of the breaking strength of the second tube 120 and the joint strength between the second tube 120 and the first tube 110 may be less than the breaking strength of the reinforcing portion 112 of the first tube 110. The joint strength between the second tube 120 and the first tube 110 may be less than the breaking strength of the second tube 120.

[0027] The breaking strengths of the first tube 110 and the second tube 120 can be adjusted, for example, by changing the forming material of the tubes or the dimensions of the tubes (outer diameter, inner diameter, wall thickness, etc.). For example, if the second tube 120 is made of polyethylene resin and the first tube 110 is made of polyamide resin, the breaking strength of the second tube 120 will be less than the breaking strength of the reinforcement portion 112 of the first tube 110. The joint strength between the second tube 120 and the first tube 110 can be adjusted, for example, by changing the welding temperature. For example, increasing the welding temperature will increase the joint strength between the second tube 120 and the first tube 110. The relative strengths of the breaking strengths and joint strengths of each part of the catheter 10 can be confirmed by tensile testing using a testing machine.

[0028] The outer tube 140 is a tubular member that extends in the longitudinal direction of the shaft portion 20. The position of the tip of the outer tube 140 is approximately the same as the position of the base end of the tip 150. The position of the base end of the outer tube 140 is approximately the same as the position of the base end of the shaft portion 20. The outer tube 140 surrounds the first tube 110, the second tube 120, the third tube 130 and the core wire 160 from the outer circumference. In other words, the first tube 110, the second tube 120, the third tube 130 and the core wire 160 are housed in the hollow portion of the outer tube 140.

[0029] The shape of the outer edge of the cross-section of the outer tube 140 is, for example, approximately elliptical. The shape of the outer edge of the cross-section may differ for each part of the outer tube 140. The outer tube 140 is formed of, for example, a resin material. The outer tube 140 may be formed of the same material throughout. The outer tube 140 may be formed of different materials for each part.

[0030] The core wire 160 is an elongated member that extends in the longitudinal direction of the shaft portion 20. The core wire 160 is located on the outer circumference of the first tube 110, the second tube 120, and the third tube 130, and is surrounded from the outer circumference by the outer tube 140. The core wire 160 extends from the tip of the shaft portion 20 to the base end of the shaft portion 20. More specifically, the tip 160d of the core wire 160 is located further forward than the tip of the reinforcing portion 112 of the first tube 110. In this embodiment, the tip 160d of the core wire 160 is located further forward than the tip of the unreinforced portion 111 of the first tube 110. In this embodiment, the tip 160d of the core wire 160 is located further forward than the base end of the tip tip 150, and further back than the tip 120d of the second tube 120.

[0031] The core wire 160 is formed from, for example, a metal. Examples of materials for forming the core wire 160 include stainless steel, Ni-Ti alloy, nickel-chromium alloy, cobalt alloy, tungsten, and the like.

[0032] The marker 170 is positioned at the tip of the shaft portion 20. The marker 170 is inserted, for example, into a through hole 156 at the base end of the tip 150 and is positioned to surround the second tube 120 from the outer circumference. The marker 170 is joined to the core wire 160, for example, by welding. The marker 170 is formed of a radiopaque material (e.g., an X-ray opaque material). Examples of radiopaque materials include platinum, gold, silver, tin, tungsten, bismuth, rhenium, tantalum, palladium, iridium, barium, and their alloys.

[0033] (Effects of this embodiment) As described above, the catheter 10 of this embodiment includes a first tube 110, a tip 150, and a second tube 120. The first tube 110 has a reinforcing portion 112 in which a reinforcing body 114 is embedded. The tip 150 is located more distal to the first tube 110. The second tube 120 is joined to the first tube 110 and the tip 150. At least one of the breaking strength of the second tube 120 and the joint strength between the second tube 120 and the first tube 110 is less than the breaking strength of the reinforcing portion 112.

[0034] In this embodiment, when a tensile force acts on the tip of the catheter 10 and causes fracture, the fracture preferentially occurs in either the second tube 120 itself or at the joint between the second tube 120 and the first tube 110. The possibility of the fracture occurring in the reinforced portion 112 where the reinforcing member 114 is located is low. Therefore, the exposure of the reinforcing member 114 to the outside when the catheter 10 fractures is suppressed.

[0035] In this embodiment, the joint strength between the second tube 120 and the first tube 110 may be less than the breaking strength of the second tube 120. In such a configuration, the rupture of the catheter 10 preferentially occurs at the joint between the second tube 120 and the first tube 110. Therefore, the exposure of the reinforcing body 114 to the outside when the catheter 10 ruptures is effectively suppressed.

[0036] In this embodiment, the first tube 110 is located towards the tip of the reinforcing portion 112 and further has an unreinforced portion 111 that does not contain the reinforcing body. The second tube 120 is joined to the unreinforced portion 111 of the first tube 110. Therefore, the exposure of the reinforcing body 114 to the outside in the event of rupture of the catheter 10 is further effectively suppressed.

[0037] In this embodiment, the catheter 10 further has a core wire 160 extending along the first tube 110. The tip 160d of the core wire 160 is located more aft than the tip of the reinforcing portion 112. No reinforcing material is placed in the portion of the reinforcing portion 112 more aft than the tip. By positioning the tip 160d of the core wire 160 more aft than the tip of the reinforcing portion 112, excessive flexibility in the portion where no reinforcing material is placed is suppressed. The tip 160d of the core wire 160 may also be located more aft than the tip of the unreinforced portion 111. This effectively suppresses excessive flexibility in the portion where no reinforcing material is placed.

[0038] In this embodiment, the catheter 10 further includes a third tube 130 extending along the first tube 110 (arranged side by side so that their long axes are parallel to each other). The tip 150, the first tube 110, the second tube 120, and the third tube 130 form a shaft portion 20 extending in the longitudinal direction of the catheter 10. The first tube 110 and the second tube 120 form a first lumen 11L. The tip of the first lumen 11L opens at the tip of the shaft portion 20, and the base end of the first lumen 11L opens in the middle portion between the tip and base of the shaft portion 20. The third tube 130 forms a second lumen 12L. The tip of the second lumen 12L opens at the tip of the shaft portion 20, and the base end of the second lumen 12L opens at the base end of the shaft portion 20. Therefore, the first lumen 11L functions as a rapid exchange type lumen, and the second lumen 12L functions as an over-the-wire type lumen. In this embodiment, in the catheter 10 having the above two lumens, the exposure of the reinforcing body 114 to the outside when the catheter 10 breaks is suppressed.

[0039] (modified version) The technologies disclosed herein are not limited to the embodiments described above and can be modified in various forms without departing from their essence, for example, the following modifications are possible.

[0040] The configuration of the catheter 10 in the above embodiment is merely an example and can be modified in various ways. For example, in the above embodiment, the reinforcing member 114 may be positioned up to the tip of the first tube 110.

[0041] In the above embodiment, the base end 123 of the second tube 120 may cover only a portion of the tip side of the unreinforced portion 111 of the first tube 110. The base end 123 of the second tube 120 may cover a portion of the reinforced portion 112 of the first tube 110 in addition to the unreinforced portion 111. The tip of the first tube 110 may cover the base end 123 of the second tube 120 from the outer circumference.

[0042] In the above embodiment, the position of the tip 160d of the core wire 160 may be on the proximal side of the tip of the unreinforced portion 111 of the first tube 110, or on the proximal side of the tip of the reinforced portion 112.

[0043] The techniques disclosed herein are not limited to catheters having two lumens, but are equally applicable to catheters having one lumen or catheters having three or more lumens.

Claims

1. A first tube (110) having a reinforcing section (112) in which a reinforcing body (114) is embedded, A tip (150) located further forward than the first tube (110), The first tube (110) and the second tube (120) joined to the tip (150), Equipped with, A catheter (10) wherein at least one of the rupture strength of the second tube (120) and the joint strength between the second tube (120) and the first tube (110) is less than the rupture strength of the reinforcing portion (112).

2. A catheter (10) according to claim 1, The aforementioned joint strength is less than the breaking strength of the second tube (120) of the catheter (10).

3. A catheter (10) according to claim 1 or claim 2, The first tube (110) is located closer to the tip than the reinforcing portion (112) and further has an unreinforcing portion (111) that does not include a reinforcing body. The second tube (120) is a catheter (10) joined to the unreinforced portion (111) of the first tube (110).

4. A catheter (10) according to claim 3, The invention further comprises a core wire (160) extending along the first tube (110), The tip of the core wire (160) is located more towards the tip of the reinforcing portion (112) of the catheter (10).

5. A catheter (10) according to claim 4, The tip of the core wire (160) is located more distally than the tip of the unreinforced portion (111) of the catheter (10).

6. A catheter (10) according to any one of claims 1 to 5, The present invention further comprises a third tube (130) extending along the first tube (110), The tip (150), the first tube (110), the second tube (120), and the third tube (130) form a shaft portion (20) that extends in the longitudinal direction of the catheter (10). The first tube (110) and the second tube (120) form a first lumen (11L), wherein the tip of the first lumen (11L) opens at the tip of the shaft portion (20), and the base end of the first lumen (11L) opens in the intermediate portion between the tip and base end of the shaft portion (20), The third tube (130) is a second lumen (12L), the catheter (10) having a tip of the second lumen (12L) that opens at the tip of the shaft portion (20) and a base end of the second lumen (12L) that opens at the base end of the shaft portion (20).

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