JP2021023443A - catheter - Google Patents

Abstract

To provide a catheter whose base end part has rigidity and whose end part is soft and difficult to peel.SOLUTION: A catheter 1 includes a first tubular part 11 and a second tubular part 21. The first tubular part 11 is provided with a large diameter part 11A extending from an end to a base end side; and a small diameter part 11B which extends from a base end of the large diameter part 11A to the base end side and has an external diameter smaller than the external diameter of the large diameter part 11A. An outer periphery of the small diameter part 11B is coated with the second tubular part 21. The catheter is formed so that bending rigidity of a material composing the first tubular part 11 is smaller than bending rigidity of the material composing the second tubular part 21.SELECTED DRAWING: Figure 1A

Description

The present invention relates to a catheter.

A guide catheter or the like to be inserted into a body cavity such as a blood vessel is required to have flexibility at its tip so that it can smoothly proceed inside the curved body cavity, for example. On the other hand, the proximal end of the catheter is required to be rigid so that it is not pushed back from the position where the catheter is placed due to the operation of a device such as a guide wire used in combination with the catheter.

As such a catheter, for example, a catheter having a structure in which a tip is extended toward the tip side at the tip of a rigid outer tube is disclosed (see, for example, Patent Document 1).

According to the catheter described above, since the tip is made of a material that is more flexible than the outer tube, both the flexibility of the tip and the rigidity of the proximal end can be expected.

U.S. Pat. No. 6,648,874

However, in the conventional catheter as described above, since the outer tube bonded to the base end of the tip tip is divided into two layers, the tip tip and the outer side are compared with the case where the outer tube is bonded to the outer tube formed of a single layer. There is a high possibility that the tube will peel off.

The present invention has been made based on the above circumstances, and an object of the present invention is to provide a catheter having a rigid base end portion, a flexible tip portion, and being difficult to peel off.

Some aspects of this disclosure include
(1) A first tubular portion and a second tubular portion are provided.
The first tubular portion has a large diameter portion extending from the tip toward the proximal end side, and extends from the proximal end of the large diameter portion toward the proximal end side and is smaller than the outer diameter of the large diameter portion. It has a small diameter part with an outer diameter,
The outer circumference of the small diameter portion is covered with the second tubular portion.
A catheter in which the flexural rigidity of the material constituting the first tubular portion is smaller than the flexural rigidity of the material constituting the second tubular portion.
(2) The catheter according to (1) above, wherein the tip portion of the small diameter portion has a tapered portion whose outer diameter gradually decreases toward the proximal end side.
(3) The catheter according to (1) or (2), which includes a braid that is at least partially embedded in the first tubular portion, and (4) the braid is the first tubular. The catheter according to (3) above, which is embedded so as to straddle the portion and the second tubular portion.

In the present specification, the "tip side" means a direction along the long axis direction of the catheter, in which the large diameter portion is located with respect to the small diameter portion of the first tubular portion. Further, the "base end side" means a direction along the long axis direction of the catheter and a direction opposite to the tip end side. Further, the "tip" refers to the end portion on the distal end side of any member or portion, and the "base end" indicates the end portion on the proximal end side of any member or portion. Further, the “tip portion” refers to a portion of any member or portion that includes the tip and extends halfway from the tip toward the proximal end side. The "base end portion" refers to a portion of any member or portion that includes the proximal end and extends halfway from the proximal end toward the distal end side. "Flexural rigidity" refers to the "flexural modulus" specified in JIS K 7171 (2016).

INDUSTRIAL APPLICABILITY The present invention can provide a catheter having a rigid proximal end and a flexible distal end that is difficult to peel off.

It is a partial notch schematic side view which shows the 1st Embodiment of this invention. It is a partially enlarged schematic cross-sectional view which shows an example of the catheter tip part in 1st Embodiment. It is a partial notch schematic side view which shows the 2nd Embodiment of this invention. It is a partial notch schematic side view which shows the 3rd Embodiment of this invention. It is a partial cutout schematic side view which shows the modification of this embodiment. It is a partial cutout schematic side view which shows the modification of this embodiment. It is a partially enlarged schematic cross-sectional view which shows the modification of this embodiment. It is a partially enlarged schematic cross-sectional view which shows the modification of this embodiment. It is a partially enlarged schematic cross-sectional view which shows the modification of this embodiment.

The catheter includes a first tubular portion and a second tubular portion, and the first tubular portion includes a large-diameter portion extending from the tip toward the proximal end side and a base from the proximal end of the large-diameter portion. It is provided with a small diameter portion extending toward the end side and having an outer diameter smaller than the outer diameter of the large diameter portion, and the outer circumference of the small diameter portion is covered with the second tubular portion. The bending rigidity of the material constituting the first tubular portion is smaller than the bending rigidity of the material constituting the second tubular portion.

In addition, in this specification, a "catheter tip portion" refers to a region in a long axis direction in which a large diameter portion of a first tubular portion is particularly located.

Hereinafter, the first to third embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the embodiments described in the drawings. Further, the dimensions of the catheter shown in each drawing are the dimensions shown for facilitating the understanding of the implementation contents, and do not correspond to the actual dimensions.

[First Embodiment]
FIG. 1A is a schematic side view of a partially cutaway showing the first embodiment of the present invention. As shown in FIG. 1A, the catheter 1 is roughly composed of a first tubular portion 11, a second tubular portion 21, a braided body 31, a tip tip 41, and a connector 51. ..

The first tubular portion 11 is a longitudinal portion in which a through hole 11h penetrating from the tip end to the base end is formed. The first tubular portion 11 includes a large diameter portion 11A and a small diameter portion 11B.

The large diameter portion 11A is a portion extending from the tip end toward the base end side. Specifically, as the large diameter portion 11A, for example, one having a constant outer diameter along the major axis direction (see FIG. 1A), and at least a part of the outer diameter in the major axis direction gradually or gradually changes. Alternatively, a combination of these (not shown) or the like can be exemplified.

The small diameter portion 11B is a portion extending from the proximal end of the large diameter portion 11A toward the proximal end side and having an outer diameter smaller than the outer diameter of the large diameter portion 11A. Specifically, as the small diameter portion 11B, for example, one having a constant outer diameter along the major axis direction (see FIG. 1A), or at least a part of the outer diameter in the major axis direction gradually or gradually changes or An example of a combination of these (not shown) can be exemplified. The outer circumference of the small diameter portion 11B is covered with a tubular (cylindrical) second tubular portion 21.

The tip of the second tubular portion 21 is continuous with the proximal end of the large diameter portion 11A. The second tubular portion 21 and the large diameter portion 11A and / or the small diameter portion 11B may be fixed or merely in contact with each other. When the second tubular portion 21 and the large diameter portion 11A and / or the small diameter portion 11B are fixed, for example, a method of bonding using an adhesive, a method of welding by heating, or the like is adopted as the fixing method. Can be done.

It is preferable that the outer diameter of the tip of the second tubular portion 21 matches the outer diameter of the base end of the large diameter portion 11A in the first tubular portion 11, and the outer diameter of the tip of the second tubular portion 21 is The outer diameter of the large diameter portion 11A and the second tubular portion 21 coincides with the outer diameter of the base end of the large diameter portion 11A in the first tubular portion 11, and the outer diameter of the large diameter portion 11A is from the tip of the large diameter portion 11A to the second tubular portion 21. It is more preferable that the shape is constant over the base end, or that the outer diameter gradually decreases from the base end of the second tubular portion 21 toward the tip of the large diameter portion 11A. As a result, the catheter 1 can be smoothly advanced inside the body cavity.

Examples of the material constituting each of the first and second tubular portions 11 and 21 include resin materials such as polyamide, polyamide elastomer, polyolefin, polyester, polyester elastomer, polyurethane, polyurethane elastomer, silicone, and fluororesin. ..

Here, the flexural rigidity of the material constituting the first tubular portion 11 can be configured to be smaller than the flexural rigidity of the material constituting the second tubular portion 21. As a combination of the materials constituting the first and second tubular portions 11 and 21, two kinds of the above materials may be combined, but the same kind of materials may be combined. When the same kind of materials are combined, it is possible to form the first tubular portion 11 and the second tubular portion 21 having a rigidity larger than the flexural rigidity of the first tubular portion 11 by using materials of different grades. Thereby, the rigidity of the base end portion and the flexibility of the tip end portion (large diameter portion 11A) can be imparted to the catheter 1.

The braided body 31 is a member that is at least partially embedded in the first tubular portion 11. The braided body 31 can be formed, for example, by braiding in a mesh pattern using the strands 31a. As the strand 31a, one or more single wires or stranded wires can be used. However, the single wire means one single wire, and the stranded wire means a bundle of wires formed by twisting a plurality of single wires in advance. As shown in FIG. 1B, at least a part of the braided body 31 may be embedded in the tip tip 41.

Examples of the material constituting the braided body 31 include stainless steel such as SUS304 and SUS316; platinum, tungsten; and a resin material such as reinforced plastic.

As described above, the catheter 1 can increase its own strength by embedding the braided body 31 in the first tubular portion 11, the first tubular portion 11 and the tip tip 41, and the catheter 1 can be increased. It is possible to prevent breakage, crushing, and kinking.

The tip tip 41 is a member extending from the tip of the first tubular portion 11 toward the tip side. The tip tip 41 can be formed so as to taper toward the tip side, for example. The tip tip 41 has a through hole 41h along the major axis direction, and the through hole 41h and the through hole 11h of the first tubular portion 11 communicate with each other.

The tip tip 41 can be formed of, for example, a material that is more flexible than the material that constitutes the first tubular portion 11. Examples of the material constituting the tip chip 41 include resin materials such as polyurethane, polyurethane elastomer, polyamide, and polyamide elastomer. As a result, the catheter 1 can be smoothly advanced in the body cavity while further reducing the load on the body tissue.

The connector 51 is a member for which the operator grips the catheter 1. The connector 51 has, for example, a through hole 51h that is connected to the base end portion of the first tubular portion 11 and communicates with the above-mentioned through hole 11h. An opening 51a is formed at the end of the through hole 51h on the base end side. The shape of the connector 51 is not particularly limited as long as the effect of the present invention is not impaired, and for example, the connector 51 can be formed into a shape that is easy for the operator to operate.

Here, the lumen L is formed by the through hole 41h of the tip tip 41, the through hole 11h of the first tubular portion 11, and the through hole 51h of the connector 51. For example, a medical device such as a guide wire, a liquid such as a chemical solution, or the like is inserted into the lumen L through the opening 51a.

Next, a mode of use of the catheter 1 will be described. Here, a procedure in which the catheter 1 is used as a guiding catheter and a stenosis formed in a coronary artery of the heart is expanded with a balloon catheter will be illustrated.

Prior to the use of the catheter 1, a guide wire A (not shown) is first inserted into a blood vessel, and the tip thereof is sent close to the entrance of the coronary artery of the heart. Next, the guide wire A is inserted into the lumen L of the catheter 1, and the catheter 1 is pushed forward along the guide wire A into the blood vessel so that the tip reaches the entrance of the coronary artery of the heart. At this time, the catheter 1 is fed while following the curvature of the blood vessel.

Next, the guide wire A is pulled out and replaced with a thinner guide wire B (not shown) for a balloon catheter, and the tip of the guide wire B reaches a position where it passes through the stenosis portion via the catheter 1. Next, a balloon catheter (not shown) is inserted along the guide wire B to the inside of the stenosis, and the stenosis is expanded by the balloon for treatment. After this treatment, the procedure is completed by removing the balloon catheter, the catheter 1, and the guide wire B in this order from the body.

As described above, since the catheter 1 has the above configuration, the base end portion has rigidity, the tip end portion is flexible, and peeling of the tip end portion can be suppressed. As a result, the catheter 1 can be smoothly and surely delivered to a desired site in the body cavity without peeling off the tip portion (large diameter portion 11A) even if the blood vessel is complicatedly curved.

[Second Embodiment]
FIG. 2 is a schematic side view of a partially cutaway showing a second embodiment of the present invention. As shown in FIG. 2, the catheter 2 is roughly composed of a first tubular portion 12, a second tubular portion 22, a braided body 31, a tip tip 41, and a connector 51. .. The catheter 2 differs from the first embodiment in that it includes a first tubular portion 12 and a second tubular portion 22. Since the configurations of the braided body 31, the tip tip 41, and the connector 51 are the same as those of the first embodiment, the same parts are designated by the same reference numerals and detailed description thereof will be omitted. Further, since the configurations other than the configurations of the first tubular portion 12 and the second tubular portion 22 and the usage mode of the catheter 2 shown below are the same as those of the first embodiment, the description thereof will be omitted. ..

The first tubular portion 12 includes a large diameter portion 12A and a small diameter portion 12B. The large diameter portion 12A extends from the tip toward the proximal end side. The small diameter portion 12B is formed so as to extend from the proximal end of the large diameter portion 11A toward the proximal end side and to be smaller than the outer diameter of the large diameter portion 12A. The catheter 2 has a tapered portion 12Ba in which the tip portion of the small diameter portion 12B gradually decreases in outer diameter toward the proximal end side.

The second tubular portion 22 covers the outer circumference of the small diameter portion 12B. Specifically, for example, the second tubular portion 22 is provided so that the tip portion covers the tapered portion 12Ba of the small diameter portion 12B, and the outer diameter of the second tubular portion 22 is constant along the major axis direction. The thickness of the second tubular portion 22 can be formed so as to increase from the tip end to the proximal end side on the outer peripheral surface of the tapered portion 12Ba.

As described above, since the catheter 2 has the above configuration, it is possible to avoid a sudden change in rigidity at the boundary portion between the large diameter portion 12A and the small diameter portion 12B, and a kink occurs at the boundary portion. Can be suppressed. Further, when the tip portion of the second tubular portion 22 is fixed to the tapered portion 12Ba, the contact area between the two can be increased, and the first tubular portion 12 and the second tubular portion 22 are separated from each other. It becomes difficult.

[Third Embodiment]
FIG. 3 is a schematic side view of a partial notch showing a third embodiment of the present invention. As shown in FIG. 3, the catheter 3 is roughly composed of a first tubular portion 13, a second tubular portion 23, a braided body 33, a tip tip 41, and a connector 51. .. The catheter 3 differs from the first embodiment in that it includes a first tubular portion 13, a second tubular portion 23, and a braided body 33. Since the configurations of the tip tip 41 and the connector 51 are the same as those of the first embodiment, the same parts are designated by the same reference numerals and detailed description thereof will be omitted. In addition, the configurations other than the configurations of the first tubular portion 13, the second tubular portion 23, and the braided body 33 shown below, and the usage mode of the catheter 3 are the same as those of the first embodiment. The explanation is omitted.

The first tubular portion 13 includes a large diameter portion 13A and a small diameter portion 13B. The large diameter portion 13A extends from the tip toward the proximal end side. The small diameter portion 13B is formed so as to extend from the proximal end of the large diameter portion 13A toward the proximal end side and to be smaller than the outer diameter of the large diameter portion 13A. The second tubular portion 23 covers the outer circumference of the small diameter portion 13B.

The braided body 33 is a member that is at least partially embedded in the first tubular portion 13. In the catheter 3, the braided body 33 is embedded so as to straddle the first tubular portion 13 and the second tubular portion 23. Specifically, in the braided body 33, for example, the tip portion 33A and the base end portion 33C are embedded in the first tubular portion 13, and the intermediate portion 33B between the tip portion 33A and the base end portion 33C is the second. It can be embedded in the tubular portion 23. In the braided body 33 of such an embodiment, the tip portion 33A and the intermediate portion 33B, and / or the intermediate portion 33B and the base end portion 33C are respectively continuous strands 33a.

As described above, since the catheter 3 has the above configuration, the braided body 33 is embedded so as to straddle the first tubular portion 13 and the second tubular portion 23, so that the first tubular portion is formed. The connection strength between the portion 13 and the second tubular portion 23 can be increased, and the second tubular portion 23 can be suppressed from peeling from the first tubular portion 13.

It should be noted that the present invention is not limited to the configuration of the above-described embodiment, but is indicated by the scope of claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims. Will be done.

For example, in the above-described embodiment, the catheters 1 to 3 having the braided bodies 31, 33, the tip tip 41, and the connector 51 have been described, but even if the catheter does not have at least one of these. Good. For example, the catheter may be a catheter 1m1 (see FIG. 4A) having a first tubular portion 11m1, a second tubular portion 21 and a connector 51, and the first tubular portion 11m2 and the second. A catheter 1 m2 (see FIG. 4B) having a tubular portion 21, a braided body 31 m2 (for example, one whose tip is embedded up to a large diameter portion of the first tubular portion 11 m2) and a connector 51. May be good.

Further, in the third embodiment described above, the catheter in which the tip end portion 33A and the base end portion 33C of the braided body 33 are embedded in the first tubular portion 13 and the intermediate portion 33B is embedded in the second tubular portion 23. Although the third has been described, it is sufficient that at least a part of the braided body is embedded in the first tubular portion of the catheter. Examples of such a catheter include a catheter 1m3 in which the tip portion 33Am3 of the braided body 33m3 is embedded in the first tubular portion 13m3 and the proximal end portion 33Cm3 is embedded in the second tubular portion 23m3 (see FIG. 5A). A long axis in which a catheter 1m4 (see FIG. 5B) in which a tip portion 33Am4 of a braided body 33m4 is embedded in a second tubular portion 23m4 and a base end portion 33Cm4 is embedded in a first tubular portion 13m4 and a small diameter portion 13Bm5 are arranged. The braided body 33m5 is sandwiched between the first tubular portion 13m5 and the second tubular portion 23m5 so that the strands constituting the braided body 33m5 are sandwiched between the first tubular portion 13m5 and the second tubular portion 23m5 at the portion in the direction. A catheter 1 m5 (see FIG. 5C) embedded so as to straddle the tubular portion 23 m5 of the above.

1,2,3 Catheter 11,12,13 First tubular part 11A, 12A, 13A Large diameter part 11B, 12B, 13B Small diameter part 12Ba Tapered part 21,22,23 Second tubular part 31,33 Braid

Claims (4)

It has a first tubular part and a second tubular part,
The first tubular portion has a large diameter portion extending from the tip toward the proximal end side and extends from the proximal end of the large diameter portion toward the proximal end side and is smaller than the outer diameter of the large diameter portion. It has a small diameter part with an outer diameter,
The outer circumference of the small diameter portion is covered with the second tubular portion.
A catheter in which the flexural rigidity of the material constituting the first tubular portion is smaller than the flexural rigidity of the material constituting the second tubular portion. The catheter according to claim 1, wherein the tip portion of the small diameter portion has a tapered portion whose outer diameter gradually decreases toward the proximal end side. The catheter according to claim 1 or 2, wherein at least a part thereof includes a braided body embedded in the first tubular portion. The catheter according to claim 3, wherein the braid is embedded so as to straddle the first tubular portion and the second tubular portion.

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