WO2023171064A1

WO2023171064A1 - Catheter

Info

Publication number: WO2023171064A1
Application number: PCT/JP2022/045232
Authority: WO
Inventors: 隆史伊藤
Original assignee: テルモ株式会社
Priority date: 2022-03-07
Filing date: 2022-12-08
Publication date: 2023-09-14

Abstract

Provided is a catheter excellent in operability and capable of suppressing excessive bending of a part thereof on the proximal end side while maintaining permeability to a lesion in a predetermined range on the distal end side of the catheter.　The present invention comprises: a shaft (10) having a lumen (11) that makes the distal end and proximal end communicate with each other in the axial center direction; an operating portion (20) fixed to the proximal end of the shaft (10); and a reinforcing tube (30) which has a tubular body covering the periphery of the shaft (10) and capable of sliding in the axial center direction with respect to the shaft (10) and which comprises, at the proximal end, a coupling portion (33) that can be coupled to the operating portion (20). The maximum outer diameter (D3) of the coupling portion (33) is smaller than the maximum outer diameter (D4) of the operating portion (20). In a state in which the coupling portion (33) is coupled to the operating portion (20), the distal end of the reinforcing tube (30) is located at a position spaced apart from the distal end of the shaft (10) toward the proximal end side by 200-600 mm inclusive.

Description

catheter

The present invention relates to a catheter used within a lumen of a blood vessel or the like.

In recent years, treatment within the lumen of blood vessels and the like using catheters has become popular because the surgical invasiveness is extremely low. Catheters are used by being selectively introduced into the intricately branched blood vessels in the body, and their internal lumens allow them to supply therapeutic agents, diagnostic contrast agents, etc. into the body, and to connect other therapeutic catheters. It is possible to guide the robot to a target position (for example, see Patent Document 1). When treating peripheral areas of blood vessels or complex lesions using a catheter, it is necessary to reduce the outer diameter of the catheter in order to improve the ability to reach the target blood vessel and pass through the lesion.

JP2014-230710A

The inner diameter of the blood vessel is, for example, about 10 mm in the common iliac artery, but about 3 to 4 mm in the more distal below-the-genital artery, and becomes smaller as it becomes more distal. In order to reach lesions in peripheral areas, it is necessary to use thin catheters suitable for peripheral lesions, but thin catheters tend to bend excessively in blood vessels with large inner diameters. For this reason, when a catheter thinner than the appropriate thickness for the inner diameter of the blood vessel is inserted, the back-up performance of the guide wire inserted into the catheter to support the catheter and the pushability of the catheter itself are reduced.

The present invention has been made to solve the above-mentioned problems, and is capable of suppressing excessive bending of the proximal portion of the catheter while maintaining the ability to pass through a predetermined range of lesions on the distal end side of the catheter. The purpose is to provide a catheter with excellent operability.

A catheter according to the present invention that achieves the above object includes a shaft having a lumen penetrating in the axial direction from the distal end to the proximal end, an operating section fixed to the proximal end of the shaft, and a It is a tubular body that is slidable in the axial direction with respect to the shaft, and has a reinforcing tube that has a connecting portion that can be connected to the operating portion at the base end, and the maximum outer diameter of the connecting portion is equal to the maximum outer diameter of the connecting portion. The reinforcing tube is smaller than the maximum outer diameter of the operating portion, and when the connecting portion is connected to the operating portion, the distal end of the reinforcing tube is disposed at a position of 200 mm or more and 600 mm or less from the distal end of the shaft to the proximal end side. It is characterized by

The catheter configured as described above suppresses excessive deflection within the blood vessel by covering the outside of the shaft with a reinforcing tube, and the reinforcing tube extends from the distal end of the shaft to the proximal end in a range of 200 mm or more and 600 mm or less. Excessive deflection of the proximal portion can be suppressed while maintaining the passability to a predetermined range of lesions on the distal end side of the shaft that is not covered by the shaft. In addition, since the connecting part of the reinforcing tube can be connected to the operating part fixed to the base end of the shaft, and the maximum outer diameter of the connecting part is smaller than the maximum outer diameter of the operating part, the operator can operate the operating part. The connecting portion of the reinforcing tube is less likely to interfere with the operation when the reinforcing tube is operated, and the reinforcing tube can be slid on the shaft and moved away from the operating section if necessary. Therefore, the catheter has excellent operability.

The operation section may have a ring-shaped connection recess that is depressed from the distal end side to the base end side, and the connection section may be able to fit into the connection recess and be connected to the operation section. As a result, the connecting part of the reinforcing tube is surrounded by the tip of the operating part, so when the operator operates the operating part, the connecting part of the reinforcing tube is less likely to interfere with the operation, and the connecting part of the reinforcing tube does not interfere with the shaft fixed to the operating part. It is easy to operate the reinforcing tube in one piece. Further, if necessary, the reinforcing tube can be moved away from the operating section by sliding the reinforcing tube toward the tip of the shaft.

The connecting portion may be connectable to the operating portion by covering the outer surface of the distal end side of the operating portion. Thereby, in the catheter, the connecting portion of the reinforcing tube and the operating portion can be easily operated in an integrated manner. In addition, it is easy to remove the connecting portion of the reinforcing tube from the operating section, and if necessary, it is easy to slide the reinforcing tube toward the tip of the shaft and move it away from the operating section. .

The reinforcing tube may have a plurality of protrusions on the inner surface. This creates a gap between the shaft and the reinforcing tube, making it easier for the sterilizing gas to reach between the shaft and the reinforcing tube. Furthermore, by reducing the contact area between the reinforcing tube and the shaft, it is possible to improve the slidability of the reinforcing tube with respect to the shaft.

The reinforcing tube may have a breakable weakened portion extending from the distal end to the proximal end. This allows the catheter to destroy the weakened portion located outside the body and remove the reinforcing tube from the shaft while the distal end of the shaft is inserted into the blood vessel.

The reinforcing tube may have a thicker portion on the distal end side than on the proximal end side. As a result, the thick portion and the shaft covered by the thick portion form a locally hard-to-flex portion on the proximal side of the portion to be inserted into the lesion, and the ability to engage with the blood vessel, push into the blood vessel, etc. can be adjusted.

FIG. 1 is a plan view showing a catheter according to an embodiment. FIG. 2 is an enlarged cross-sectional view along the axis showing the catheter according to the embodiment. 3 is a sectional view taken along line AA in FIG. 2. FIG. FIG. 7 is a sectional view perpendicular to the axis showing a first modified example of the catheter. It is a sectional view along the axis showing a second modification of the catheter. It is a top view which shows the 3rd modification of a catheter.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the dimensions in the drawings may be exaggerated and differ from the actual dimensions for convenience of explanation. Further, in this specification and the drawings, constituent elements having substantially the same functional configuration are designated by the same reference numerals and redundant explanation will be omitted. In this specification, the side of the catheter that is inserted into the living body lumen will be referred to as the "distal side," and the side that will be operated will be referred to as the "proximal side."

The catheter 1 according to the present embodiment is, for example, introduced into a blood vessel from the radial artery of the arm and inserted into the artery of the lower limb, and is used for treatment, diagnosis, etc. The arteries of the lower limbs are the arteries near the aortoiliac artery bifurcation and on the more distal side. Note that the catheter 1 may be inserted from a blood vessel other than the arm artery. Further, the catheter 1 may be used for treatment and diagnosis of blood vessels other than the arteries of the lower limbs. Further, the catheter 1 may be inserted into a bile duct, trachea, esophagus, urethra, or other living body lumen or body cavity, and used for treatment, diagnosis, and the like.

As shown in FIG. 1, the catheter 1 includes an elongated shaft 10, an operating section 20 fixed to the proximal end of the shaft 10, and a tubular reinforcing tube 30 that covers the shaft 10.

As shown in FIGS. 1 to 3, the shaft 10 is a flexible tubular member, and has a lumen 11 formed therein from the base end to the distal end. A guide wire is inserted through the lumen 11 when the catheter 1 is inserted into a blood vessel. Furthermore, the lumen 11 can also be used as a passage for medical solutions, embolic substances, contrast agents, medical instruments, and the like.
But that's fine.

The shaft 10 is composed of a plurality of layers, including an inner layer 12 forming the inner surface of the lumen 11, a reinforcing body 13 formed outside the inner layer 12, and a reinforcing body 13 formed outside the inner layer 12 and the reinforcing body 13. An outer layer 14 is provided.

A lumen 11 is formed inside the inner layer 12. The constituent material of the inner layer 12 is preferably a fluororesin such as polytetrafluoroethylene (PTFE) or a low-friction material such as high-density polyethylene (HDPE). Alternatively, the material may be a mixture of polyamide resin, polyamide elastomer, polyester, polyester elastomer, and metal powder having X-ray contrast properties such as tungsten.

The reinforcing body 13 is formed by braiding a plurality of wire rods 15 into a tubular shape around the outer periphery of the inner layer 12 so as to have gaps. The wire 15 used in the reinforcing body 13 may be made of stainless steel, a metal wire such as platinum (Pt) or tungsten (W), resin fiber, carbon fiber, glass fiber, or the like.

The outer layer 14 is a tubular member that covers the outer periphery of the inner layer 12 and the reinforcing body 13. The constituent material of the outer layer 14 is, for example, polyolefin (for example, polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomer, or a mixture of two or more of these), polyvinyl chloride, Polymer materials such as polyamide, polyester elastomer, polyamide elastomer, polyurethane, polyurethane elastomer, polyimide, and fluororesin, thermoplastic resins such as mixtures thereof, and thermosetting resins such as epoxy resins can be used. Alternatively, the material may be a mixture of polyamide resin, polyamide elastomer, polyester, polyester elastomer, or a metal powder having X-ray contrast properties such as tungsten, or the same material as the inner layer 12 may be used.

Further, the shaft 10 has a shaft main portion 16 having a substantially constant outer diameter, and a shaft distal end portion 17 which is disposed on the distal end side of the shaft main portion 16 and whose outer diameter decreases toward the distal end. A base end of the shaft main portion 16 is fixed to a hub 21 of the operating section 20, which will be described later.

The outer diameter D1 of the shaft main portion 16 is not particularly limited, but is, for example, 0.70 mm or more and 0.85 mm or less.

The operating section 20 has a hub 21 and an anti-kink protector 22. The maximum outer diameter D4 of the operating section 20 in FIG. It may also be the diameter. Furthermore, the operating portion 20 may be a combination of the hub 21 and the kink-resistant protector. The hub 21 has a proximal end portion of the shaft main portion 16 fixed in a liquid-tight manner by adhesive, heat fusion, a fastener (not shown), or the like. The hub 21 functions as an insertion port for guide wires and medical instruments into the lumen 11, an injection port for medical solutions, embolic substances, contrast agents, etc. into the lumen 11, and also serves as a gripping portion when operating the catheter 1. It also functions as The constituent material of the hub 21 is not particularly limited, but thermoplastic resins such as polycarbonate, polyamide, polysulfone, polyarylate, and methacrylate-butylene-styrene copolymer can be suitably used.

The anti-kink protector 22 is made of an elastic material and is provided so as to surround the shaft 10, and suppresses the kink of the shaft 10 at the connecting portion 33 between the shaft 10 and the hub 21. The kink-resistant protector 22 has a tubular connecting convex portion 23 that protrudes toward the distal end so as to form a gap with the outer peripheral surface of the shaft 10, and extends from the distal end to the base so as to be surrounded by the connecting convex portion 23. A ring-shaped connecting recess 24 is formed that is recessed toward the end. As the constituent material of the kink-resistant protector 22, for example, natural rubber, silicone resin, etc. can be suitably used.

The reinforcing tube 30 is a tube body for reinforcing the shaft 10. The reinforcing tube 30 is a tube body that covers the circumference of the shaft 10 and is slidable in the axial direction X of the shaft 10 with respect to the shaft 10. The reinforcing tube 30 includes a tapered portion 31 whose outer diameter decreases toward the tip, a reinforcing tube main portion 32 whose inner diameter and outer diameter are approximately constant, and a connection that can fit into and be connected to the connection recess 24 of the operating section 20. 33. The outer diameter D2 of the reinforcing tube main part 32 is not particularly limited as long as it is larger than the outer diameter D1 of the shaft main part 16, and is, for example, 0.85 mm or more and 1.5 mm or less. When the outer diameter D1 of the shaft main portion 16 is 0.85 mm, the outer diameter D2 of the shaft main portion 16 is preferably 0.95 mm or more and 1.5 mm or less.

The reinforcing tube 30 is formed with a breakable gradually weakened portion 34 extending from the distal end to the proximal end. The fragile portion 34 is a portion that has lower strength than surrounding portions and is more likely to be destroyed. The fragile portion 34 is formed, for example, by a perforation or a groove in which a plurality of holes are lined up. Note that the reinforcing tube 30 does not need to have the fragile portion 34.

The connecting portion 33 is a pipe continuous from the reinforcing main pipe. The maximum outer diameter D3 of the connecting portion 33 is smaller than the maximum outer diameter D4 of the operating portion 20 to be connected. The maximum outer diameter D3 of the connecting portion 33 is twice the distance (radius) from the axis of the reinforcing tube 30 to the outer surface of the connecting portion 33 that is furthest away in a direction perpendicular to the axis. The maximum outer diameter D4 of the operating section 20 is the outer surface of the operating section 20 that is farthest from the axis of the operating section 20 (or the axis of the reinforcing tube 30 connected to the operating section 20) in a direction perpendicular to the axis. The length is twice the distance (radius) to. The connecting portion 33 can fit and be connected to the operating portion 20 by entering the connecting recess 24 of the operating portion 20 . Note that the connecting portion 33 is not particularly limited as long as it can be connected to the operating portion 20 and has a maximum outer diameter D3 smaller than the maximum outer diameter D4 of the operating portion 20. For example, the connecting portion 33 may have an outer diameter and an inner diameter different from those of the reinforcing main pipe. The material constituting the reinforcing tube 30 is not particularly limited, but for example, resin materials applicable to the inner layer 12 and outer layer 14 described above can be suitably used. The reinforcing tube 30 may include a reinforcing member such as a braided wire or coil like the reinforcing body 13 provided on the shaft 10. In this case, it is difficult to provide the breakable fragile portion 34 in the reinforcing pipe 30, and the reinforcing tube 30 may not have the fragile portion 34.

In a state where the connecting portion 33 of the reinforcing tube 30 is connected to the operating portion 20, the shaft 10 has an exposed portion 18 that is not covered by the reinforcing tube 30 on the distal end side of the reinforcing tube 30. Preferably, at least a portion of the exposed portion 18, preferably the entire length of the exposed portion 18, is coated with a hydrophilic coat. The hydrophilic coat is, for example, a hydrophilic polymer, such as a cellulose-based polymer material, a polyethylene oxide-based polymer material, or a maleic anhydride-based polymer material (e.g., maleic anhydride such as methyl vinyl ether-maleic anhydride copolymer). copolymers), acrylamide-based polymers (eg, polyacrylamide, glycidyl methacrylate-dimethylacrylamide block copolymers), water-soluble nylon, polyvinyl alcohol, polyvinylpyrrolidone, and derivatives thereof. Hydrophilic polymers create a strong fixed layer of water on their surfaces, exhibit high affinity for blood within blood vessels and the blood vessel wall, and exhibit low friction. Note that the shaft 10 may be coated with a hydrophilic coat beyond the proximal end of the exposed portion 18, or may be coated with a hydrophilic coat over the entire effective length L2 of the catheter 1; A shorter range of hydrophilic coatings may also be used.

The length L1 of the exposed portion 18 along the axial direction X is preferably 100 mm or more and 600 mm or less, more preferably 200 mm or more and 600 mm or less, and still more preferably 300 mm or more and 600 mm or less.

The effective length L2 of the catheter 1 is preferably set appropriately depending on the position where the catheter 1 is inserted into the blood vessel and the position of the lesion, and is, for example, 600 mm or more and 1500 mm or less. Note that the effective length L2 of the catheter 1 is the length of a portion that can be inserted into a blood vessel, a sheath, or the like. In this embodiment, the effective length L2 of the catheter 1 is the length from the most distal end of the anti-kink protector 22 to the most distal end of the shaft 10.

Next, the operation of the catheter 1 according to this embodiment will be explained.

The catheter 1 according to the present embodiment includes a shaft 10 having a lumen 11 penetrating in the axial direction It is a tubular body that can slide in the axial direction The diameter D3 is smaller than the maximum outer diameter D4 of the operating section 20, and when the connecting section 33 is connected to the operating section 20, the distal end of the reinforcing tube 30 has a diameter of 200 mm or more and 600 mm or less from the distal end of the shaft 10 to the proximal end. placed in position. Therefore, the catheter 1 maintains the ability to pass through the lesion in the exposed portion 18 that is not covered by the reinforcing tube 30 in a predetermined range from the distal end of the shaft 10 to the proximal end, and the Excessive deflection of the portion can be suppressed by the reinforcing tube 33. Further, since the connecting portion 33 of the reinforcing tube 30 can be connected to the operating portion 20 fixed to the base end of the shaft 10, and the maximum outer diameter D3 of the connecting portion 33 is smaller than the maximum outer diameter D4 of the operating portion 20. When the operator operates the operating section 20, the connecting portion 33 of the reinforcing tube 30 is unlikely to interfere with the operation, and the reinforcing tube 30 can be slid and moved relative to the shaft 10 as necessary. Therefore, the catheter 1 has excellent operability. Furthermore, since the reinforcing tube 30 can be slid distally with respect to the shaft 10 as needed, the length of the exposed portion 18 can be shortened, and bending can be reduced, so that the guide wire inserted into the catheter can be It is expected that the backup performance for supporting the catheter 1 and the pushability of the catheter 1 itself will be improved.

As an example, the part where the outside of the shaft 10 is covered with the reinforcing tube 30 can suppress excessive bending even in a blood vessel with an inner diameter of about 10 mm, such as the common iliac artery, and the distal end side of the catheter 1 can be suppressed. The exposed portion 18 can pass through a lesion in a small blood vessel with an inner diameter of about 3 mm to 4 mm, such as a below-the-knee artery. Further, since the length of the exposed portion 18 of the catheter 1 is 200 mm or more and 600 mm or less, the catheter 1 can have a sufficient length to pass the tip of the catheter 1 to a lesion located in a thin peripheral region.

The operating portion 20 has a ring-shaped connecting recess 24 that is depressed from the distal end side to the proximal end side, and the connecting portion 33 can fit into the connecting recess 24 and be connected to the operating portion 20. As a result, the connecting part 33 of the reinforcing tube 30 is surrounded by the distal end of the operating part 20, so that when the operator operates the operating part 20, the connecting part 33 of the reinforcing tube 30 is less likely to interfere with the operation. The shaft 10 fixed to the shaft 20 and the reinforcing tube 30 can be easily operated integrally.

The reinforcing tube 30 has a breakable weakened portion 34 extending from the distal end to the proximal end. Thereby, the catheter 1 can destroy the weakened portion 34 located outside the body and remove the reinforcing tube 30 from the shaft 10 while the distal end of the shaft 10 remains inserted into the blood vessel. As a result, when treatment of a more peripheral region is required, the catheter 1 can be used without being replaced, and additional devices such as a guide wire or a catheter can be inserted into the guiding catheter.

The reinforcing tube 30 may have a thicker wall portion 36 on the distal end side than on the proximal end side. As a result, the thick portion 36 and the shaft 10 covered by the thick portion 36 form a region that is locally difficult to bend on the proximal end side of the exposed portion 18 that is inserted into the lesion, and improves the engagement with the blood vessel and the shaft 10 covered by the thick portion 36. You can adjust gender etc.

Note that the present invention is not limited to the embodiments described above, and various modifications can be made by those skilled in the art within the technical idea of the present invention. For example, as in a first modification shown in FIG. 4, the reinforcing tube 30 may have a plurality of protrusions 35 on the inner surface. Each protrusion 35 has a pin shape, but may also have a peak shape that is elongated in a predetermined direction. Thereby, a gap is formed between the shaft 10 and the reinforcing tube 30, making it easier for the sterilizing gas to reach between the shaft 10 and the reinforcing tube 30. Further, by reducing the contact area between the reinforcing tube 30 and the shaft 10, the sliding performance of the reinforcing tube 30 with respect to the shaft 10 can be improved.

Furthermore, as in the second modification shown in FIG. 5, the connecting portion 33 may be connected to the operating portion 20 by covering the outer surface of the distal end side of the operating portion 20. Thereby, in the catheter 1, the connecting portion 33 of the reinforcing tube 30 and the operating portion 20 can be easily operated in an integrated manner. In addition, the connecting portion 33 of the reinforcing tube 30 can be easily removed from the operating section 20, and if necessary, the reinforcing tube 30 can be slid toward the distal end of the shaft 10 and moved away from the operating section 20. It is easy to do.

Furthermore, as in a third modification shown in FIG. 6, the reinforcing tube 30 may have a thicker portion 36 on the distal end side that is thicker than the proximal end side. As a result, the thick portion 36 and the shaft 10 covered by the thick portion 36 form a region that is locally difficult to bend on the proximal end side of the exposed portion 18 that is inserted into the lesion, and improves the engagement with the blood vessel and the shaft 10 covered by the thick portion 36. You can adjust gender etc.

Furthermore, the portion to which the connecting portion 33 of the reinforcing tube 30 connects may be the hub 21 instead of the kink-resistant protector 22 of the operating portion 20.

Note that this application is based on Japanese Patent Application No. 2022-34445 filed on March 7, 2022, and the disclosures thereof are referenced and incorporated in their entirety.

1 Catheter 10 Shaft 11 Lumen 12 Inner layer 13 Reinforcement body 14 Outer layer 15 Wire rod 16 Shaft main part 17 Shaft tip 18 Exposed part 20 Operation part 21 Hub 22 Kink-resistant protector 23 Connection convex part 24 Connection recess 30 Reinforcement tube 31 Tapered part 32 Reinforcement Pipe main part 33 Connecting part 34 Weakening part 35 Protrusion 36 Thick part D1 Outer diameter of main shaft part D2 Outer diameter of main part of reinforcing pipe D3 Maximum outer diameter of connecting part D4 Maximum outer diameter of operating part L1 Axis of exposed part Length along the cardiac direction L2 Effective length of the catheter X Axial direction

Claims

a shaft having a lumen communicating in the axial direction from the distal end to the proximal end;
an operating section fixed to the base end of the shaft;
a reinforcing tube that is a tubular body that covers the periphery of the shaft and is slidable in the axial direction with respect to the shaft, and has a connecting portion connectable to the operating portion at the base end;
The maximum outer diameter of the connecting portion is smaller than the maximum outer diameter of the operating portion,
A catheter characterized in that, in a state in which the connecting portion is connected to the operating portion, the distal end of the reinforcing tube is disposed at a position of 200 mm or more and 600 mm or less from the distal end of the shaft to the proximal end side.
The operating portion has a ring-shaped connecting recess that is recessed from the distal end toward the proximal end,
The catheter according to claim 1, wherein the connecting portion can fit into the connecting recess and be connected to the operating portion.
The catheter according to claim 1, wherein the connecting portion is connectable to the operating portion by covering the outer surface of the distal end side of the operating portion.
The catheter according to any one of claims 1 to 3, wherein the reinforcing tube has a plurality of protrusions on its inner surface.
The catheter according to any one of claims 1 to 4, wherein the reinforcing tube has a breakable weakened portion extending from the distal end to the proximal end.
The catheter according to any one of claims 1 to 5, wherein the reinforcing tube has a thicker wall portion on the distal end side than on the proximal end side.