JP2020156820A - catheter - Google Patents

Abstract

To provide a catheter in which an embolization coil or the like in a sheath can be suitably pushed out.SOLUTION: The catheter comprises a long sheath 3 formed in a hollow form. A lumen (inner layer 4) of a distal portion of the sheath 3 includes: a first linearly extending straight portion 5; a first tapered portion 6 disposed at a distal side from the first straight portion 5; a second tapered portion 7 disposed at a distal side from the first tapered portion 6; and a second straight portion 8 disposed at a distal side from the second tapered portion 7 and extending linearly. The inclination ratios of the first tapered portion 6 and the second tapered portion 7 are different.SELECTED DRAWING: Figure 2

Description

The present invention relates to a catheter comprising a sheath.

Conventionally, an embolic coil has been used in the treatment of hypervascular tumors such as hepatocellular carcinoma and metastatic liver cancer, arteriovenous malformations, and uterine fibroids. This embolic coil is, for example, inserted into an aneurysm or the like via a sheath to fill the lumen of the aneurysm, interrupt blood flow, and function to prevent the aneurysm from rupturing. In addition, a guide wire may be inserted inside the sheath.

For example, in Patent Document 1, an embolic coil is passed through a tubular sheath (described as a microcatheter in the same document), the embolic coil is pushed out by an insertion tool, and the embolic coil is expanded into an aneurysm. The deployment system is disclosed.

Japanese Patent Publication No. 2011-528267

However, in the embolic coil deployment system of Patent Document 1, since the sheath bends in the blood vessel, a frictional force is applied to the embolic coil from the inner wall surface of the sheath when the embolic coil is pushed out, and the embolic coil is smoothed by the insertion tool. It was difficult to push it out. Therefore, there is room for improvement in the extrudability of the embolic coil and the like.

The present invention has been made in view of the above-mentioned problems, and provides a catheter capable of suitably extruding an embolic coil or a guide wire (hereinafter, referred to as an embolic coil or the like) in a sheath. is there.

According to the present invention, a long sheath formed in a hollow shape is provided, and the lumen of the distal portion of the sheath is a linearly extending first straight portion and a distal portion of the first straight portion. A first tapered portion provided on the side, a second tapered portion provided on the distal side of the first tapered portion, and a linearly extending portion provided on the distal side of the second tapered portion. Provided is a catheter including a second straight portion to be provided, wherein the inclination ratios of the first tapered portion and the second tapered portion are different.

According to the catheter of the present invention, when the embolic coil or the like inserted into the distal lumen comes into contact with the first tapered portion and the second tapered portion of the lumen, the embolic coil or the like can be oriented stepwise. ..
In particular, since the inclination ratios of the first taper portion and the second taper portion are different, the reduced diameter length and the axial direction related to the inclination ratio are met in order to meet the need to suppress catching according to the embolic coil in the lumen. The length ratio can be adjusted in advance.

It is an overall view of the catheter which concerns on embodiment of this invention. FIG. 2 is an enlarged cross-sectional view showing a portion II of FIG. 1 of the catheter according to the present embodiment, showing the structure of the inner layer of the catheter and the state in which the embolic coil is extruded. FIG. The tip of the embolic coil is located in, (b) is the tip of the embolic coil in the first taper, and (c) is the tip of the embolic coil in the second taper. It is a figure which shows the state which is located. FIG. 5 is an enlarged cross-sectional view showing a part II of FIG. 1 of a catheter in the sheath according to the first modification. FIG. 5 is an enlarged cross-sectional view showing a part II of FIG. 1 of a catheter in a sheath according to a second modification. FIG. 5 is an enlarged cross-sectional view showing a part II of FIG. 1 of a catheter in a sheath according to a third modification.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
It should be noted that the embodiments described below are merely examples for facilitating the understanding of the present invention, and do not limit the present invention. That is, the shapes, dimensions, arrangements, etc. of the members described below can be changed and improved without departing from the gist of the present invention, and it goes without saying that the present invention includes equivalents thereof.
Further, in all the drawings, similar components are designated by the same reference numerals, and duplicate description will be omitted as appropriate. In each drawing, the dimensional ratio is adjusted so that the difference in the characteristic configuration of each part becomes clear, so that the dimensional ratio may differ from the actual dimensional ratio.

<Overview>
First, the outline of the catheter 1 according to the present embodiment will be described mainly with reference to FIGS. 1 and 2. FIG. 1 is an overall view of the catheter 1 according to the embodiment of the present invention, and FIG. 2 is an enlarged cross-sectional view showing a part II of FIG. 1 of the catheter 1 according to the present embodiment, which is an inner layer 4 of the catheter 1. It is a figure which shows the structure and the state which pushed out the embolic coil 11. FIG. 2A is a diagram showing a state in which the tip end portion of the embolic coil 11 is located on the first straight portion 5. FIG. 2B is a diagram showing a state in which the tip end portion of the embolic coil 11 is located on the first tapered portion 6. FIG. 2C is a diagram showing a state in which the tip end portion of the embolic coil 11 is located on the second tapered portion 7.

The catheter 1 according to the present embodiment includes a long sheath 3 formed in a hollow shape. The lumen (inner layer 4) of the distal portion (part II of FIG. 1) of the sheath 3 is a first straight portion 5 extending linearly and a first straight portion 5 provided distal to the first straight portion 5. A first tapered portion 6, a second tapered portion 7 provided on the distal side of the first tapered portion 6, and a second straight provided on the distal side of the second tapered portion 7 and extending linearly. Including part 8. The first tapered portion 6 and the second tapered portion 7 are characterized in that the inclination ratios are different.

According to the above configuration, in order to extend the guide wire (not shown), the embolic coil 11 or the like (hereinafter, referred to as the embolic coil 11 or the like, or only the embolic coil 11 as a representative) to the outside of the sheath 3 is distal. The embolic coil 11 inserted into the lumen of the portion comes into contact with the first tapered portion 6 and the second tapered portion 7 of the lumen in order, and the embolic coil 11 can be oriented stepwise.
In particular, since the inclination ratios of the first taper portion 6 and the second taper portion 7 are different, the inclination ratio is met in order to meet the need to suppress catching according to the size and winding diameter of the embolic coil 11 or the like in the lumen. The ratio of the reduced diameter to the axial length related to the above can be adjusted in advance.

The "chamber" may be any one that forms a space through which the embolic coil 11 can pass. That is, the "inner cavity" is not limited to the one defined by the inner layer 4 formed separately from the outer layer 10 described later, but is defined by the one in which the outer layer 10 and the inner layer 4 are integrally formed. It may be.
Further, with respect to the first straight portion 5 and the second straight portion 8, "extending linearly" means that the lumen diameter is constant in the present invention. For example, when the axis 12 is curved, the shape curved about the axis 12 is also included in the "linearly extending" shape.
Further, the "taper" is a shape in which the diameter becomes smaller toward the tip (distal end).

<Composition>
Next, the configuration of the catheter 1 according to the present embodiment will be described mainly with reference to FIGS. 1 and 2.
The catheter 1 (sheath 3) is passed through a blood vessel to feed the embolic coil 11 to the lesion portion, and has a handle 2 which is a handle portion and a base end connected to the handle 2 and is flexible. The tubular sheath 3 and the like are provided.

[sheath]
As described above, the catheter 1 (sheath 3) has an inner layer 4 formed in a hollow shape and extending in the axial direction, a wire reinforcing layer 9 covering the inner layer 4, and a radial outer side of the wire reinforcing layer 9. The outer layer 10 formed on the surface is provided.

[Inner layer, lumen]
The inner layer 4 has a part having a different diameter in the axial direction, and is formed in a cylindrical shape of about 0.01 mm. As shown in FIG. 2, the tip portion of the inner layer 4 has a large-diameter straight tubular first straight portion 5 and a tapered first tapered portion 6 and a second tapered portion 7 from the proximal side to the distal side. , A second straight portion 8 having a small diameter straight cylinder, is continuously formed.

As the material of the inner layer 4, a fluorine-based thermoplastic resin material such as polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF) and perfluoroalkoxy alkane resin (PFA) can be used. By using a fluorine-based resin material, the slidability of the embolic coil 11 can be improved.
The diameter of the lumen 4a defined by the inner layer 4 is about 0.6 to 1.0 mm at the base end of the first tapered portion 6 and about 0.5 mm at the tip of the second tapered portion 7.

The second tapered portion 7 is inclined with respect to the axis 12 of the sheath 3 at an angle α2 smaller than the angle α1 of the first tapered portion 6.
In this way, since the second tapered portion 7 is inclined at an angle α2 smaller than the angle α1 of the first tapered portion 6, the first tapered portion 6 sharply narrows the swing range of the embolic coil 11. The second tapered portion 7 can guide the embolic coil 11 so as to extend outwardly in the distal direction. Here, the "angle" of the sheath 3 with respect to the axis 12 refers to the angle on the acute angle side of the angle with respect to the axis 12. Here, the angle α1 is, for example, in the range of 0.03 degrees to 15.00 degrees, more preferably in the range of 0.04 degrees to 10.00 degrees. The angle α2 is, for example, in the range of 0.02 degrees to 12.00 degrees, more preferably in the range of 0.03 degrees to 9.00 degrees, and is smaller than α1.

Therefore, in the second tapered portion 7 which is on the tip side and has a smaller diameter than the first tapered portion 6, the inclination with respect to the axis 12 is smaller than that of the first tapered portion 6, so that the embolic coil 11 is the second tapered portion. It is possible to prevent the 7 from getting caught in the inner wall surface. Therefore, the extrudability of the embolic coil 11 can be improved.
In the present embodiment, the length of the entire tapered portion is about 100 mm, and the axial length L1 of the first tapered portion 6 and the axial length L2 of the second tapered portion 7 are equal lengths, but the first 2 The axial length L2 of the tapered portion 7 may be longer than the axial length L1 of the first tapered portion 6.

Further, when the contrast medium is flowed through the lumen 4a, the inner surface of the inner layer 4 is formed with tapered portions (first tapered portion 6 and second tapered portion 7) whose diameter is reduced toward the distal side. In addition, it is possible to increase the flow velocity on the distal side rather than the proximal side with respect to the tapered portion.
The diameter of the distal edge of the second straight portion 8 is in the range of 0.4 to 0.7 times, more preferably 0.5 to 0.5 times the diameter of the distal edge of the first straight portion 5. It is in the range of 0.62 times.

[Wire reinforcement layer]
The wire reinforcing layer 9 according to the present embodiment imparts rigidity to the sheath 3, and a plurality of metal wires (wire strands 9a) are wound in a mesh shape so as to intersect the axis 12 at an angle. It is a metal layer. The wire reinforcing layer 9 may be wound in a multi-row coil shape.
Reinforcing wire materials include metal materials such as tungsten (W), stainless steel (SUS), nickel-titanium alloys, steel, titanium, copper, titanium alloys or copper alloys, as well as shear strength higher than that of the inner layer 4 and the outer layer 10. A resin material such as polyimide (PI), polyamideimide (PAI) or polyethylene terephthalate (PET) having a high value can be used.

Each of the first tapered portion 6 and the second tapered portion 7 is provided with a wire reinforcing layer 9 in which a plurality of wire strands 9a overlap to form a two-layer structure, so that the tip of the embolic coil 11 is first. It is possible to prevent the first tapered portion 6 and the second tapered portion 7 from being deformed when sliding in contact with the 1 tapered portion 6 and the second tapered portion 7. Therefore, the user can smoothly push out the embolic coil 11 passing through the first tapered portion 6 and the second tapered portion 7.

Further, at least one of the boundary portion between the first tapered portion 6 and the second tapered portion 7 or the boundary portion between the second tapered portion 7 and the second straight portion 8 that protrudes toward the inner diameter side with respect to the axis 12. The overlapping portion (the portion where the rigidity is increased) of the wire strands 9a on the inner side and the outer side in the radial direction may be displaced from the portion.
In this way, when the tip of the embolic coil 11 moves from the first tapered portion 6 to the second tapered portion 7 or from the second tapered portion 7 to the second straight portion 8, the first tapered portion 6 and Deformation of the boundary portion with the second tapered portion 7 or the boundary portion between the second tapered portion 7 and the second straight portion 8 can be tolerated. Therefore, it is possible to smoothly push out the embolic coil 11 that moves beyond the first tapered portion 6 to the second tapered portion 7.

On the other hand, each boundary portion, the boundary portion between the first straight portion 5 and the first tapered portion 6, the boundary portion between the first tapered portion 6 and the second tapered portion 7, or the second tapered portion 7 and the second An overlapping portion (a portion where the rigidity is increased) of the inner and outer wire strands 9a in the radial direction may be arranged at the boundary portion with the straight portion 8.
By doing so, when the wire wire 9a is wound around the inner layer 4 after the inner layer 4 is formed, the wire wire 9a is not loosened at the above boundary portion, and the wire wire 9a is wound. Can be stabilized.
Further, when the tip portion of the embolic coil 11 moves to the boundary portion between the first straight portion 5 and the first tapered portion 6, which is recessed on the outer diameter side with respect to the axis 12, the embolic coil 11 presses the portion. It is possible to prevent the boundary portion from being deformed so as to sink. Therefore, the user can smoothly push out the embolic coil 11 beyond the first straight portion 5 and into the first tapered portion 6.

The wire strands 9a wound around the outer circumferences of the first tapered portion 6 and the second tapered portion 7 may be wound at the same pitch in the regions of the first tapered portion 6 and the second tapered portion 7. It may be wound at different pitches.
For example, when making it easier to bend in the region of the second tapered portion 7 than in the region of the first tapered portion 6, the second taper is larger than the pitch of the wire wire 9a wound around the first tapered portion 6. The pitch of the wire strand 9a wound around the portion 7 may be set small.
Further, the pitch of the wire wire 9a wound around the first straight portion 5 and the pitch of the wire wire 9a wound around the first tapered portion 6 may be different. Similarly, the pitch of the wire wire 9a wound around the second tapered portion 7 and the pitch of the wire wire 9a wound around the second straight portion 8 may be different.

Further, different rigidity may be set at a perspective position in the region of the second tapered portion 7. For example, when the rigidity is gradually reduced toward the distal side in the region of the second tapered portion 7, the wire element is gradually reduced from the proximal side toward the distal side of the second tapered portion 7. The pitch of the line 9a may be set so as to be gradually reduced.
In addition, regarding the adjustment of the rigidity of the sheath 3, in addition to the pitch adjustment of the wire wire 9a, the thickness and the metal one and the resin one may be included.

[Outer layer]
As the material of the outer layer 10, a thermoplastic polymer material can be used. Examples of the thermoplastic polymer material include polyimide (PI), polyamideimide (PAI), polyethylene terephthalate (PET), polyethylene (PE), polyamide (PA), polyamide elastomer (PAE), and polyether blockamide (PEBA). Examples thereof include nylon elastomer, polyurethane (PU), ethylene-vinyl acetate resin (EVA), polyvinyl chloride (PVC) or polypropylene (PP).
The outer peripheral surface of the outer layer 10 (sheath 3) according to the present embodiment is a cylindrical surface formed with a uniform diameter. In other words, the thickness of the outer layer 10 is formed so that the inner layer 4 is reduced in diameter toward the distal end by the first tapered portion 6 and the second tapered portion 7, so that the thickness of the outer layer 10 is reduced toward the distal end. It is formed to be large.

[Embolic coil]
The embolic coil 11 is made of, for example, silver-plated copper wire, and is preliminarily habituated so as to form a dumpling in a natural state. The embolic coil 11 is inserted into the lumen 4a of the catheter 1 from the proximal side, and the tip of the embolic coil 11 is forcibly stretched from the catheter 1 by abutting the inner wall surface of the inner layer 4 in the lumen 4a. Pushed in. When the embolus coil 11 is pushed out to the site to be indwelled, the embolus coil 11 curls up in a dumpling shape inside the site, enabling embolization of blood vessels.
If the diameter of the lumen 4a of the catheter 1 (sheath 3) is too large with respect to the winding diameter of the embolic coil 11, the embolic coil 11 will be curled in the lumen 4a. In order to smoothly push the embolic coil 11 toward the distal direction, the diameter of the lumen 4a of the sheath 3 is smaller than the winding diameter of the embolic coil 11 at any position in the axial direction.

[motion]
The operation of the embolic coil 11 when the user pushes the embolic coil 11 distally in the lumen 4a will be described mainly with reference to FIG.
As shown in FIG. 2A, on the proximal end side (first straight portion 5) of the large-diameter lumen 4a, the embolic coil 11 is between the peripheral wall of the lumen 4a (inner wall of the first straight portion 5). Since there is a clearance, it moves forward while trying to curl (while rubbing against the peripheral wall of the lumen 4a while trying to bend).
As shown in FIG. 2B, resistance is generated in the embolic coil 11 at the transition from the first straight portion 5 to the first taper portion 6, but the movement of the embolic coil 11 in the distal direction is restricted. The first tapered portion 6 is formed at a sufficiently gentle angle α1 so that there is no such thing.

As shown in FIG. 2C, when the embolic coil 11 passes through the second tapered portion 7, a part of the embolic coil 11 proximal to the distal end is the peripheral wall of the lumen 4a (second tapered portion 7). The embolic coil 11 tries to bend further and moves forward while rubbing against the peripheral wall of the lumen 4a by abutting against the inner wall of the lumen 4a.
When the embolic coil 11 passes through the second tapered portion 7, resistance is generated in the embolic coil 11, but the second tapered portion 7 is sufficiently provided so that the movement of the embolic coil 11 in the distal direction is not restricted. It is formed at a gentle angle α2.

Then, the embolic coil 11 reaches the second straight portion 8, further exceeds the second straight portion 8, and projects to the outside on the distal side of the sheath 3.

[First modification]
Next, the sheath 3X according to the first modification will be described mainly with reference to FIG. FIG. 3 is an enlarged cross-sectional view showing a portion II of FIG. 1 of the catheter 1 in the sheath 3X according to the first modification.
The sheath 3X includes an inner layer 24 having a first tapered portion 26 and a second tapered portion 27.
The first tapered portion 26 according to this example is inclined with respect to the axis 12 of the sheath 3 at an angle α3 smaller than that of the second tapered portion 27.

According to the above configuration, the first tapered portion 26 is inclined at an angle α3 smaller than the second tapered portion 27 (angle α4), so that the embolic coil 11 inserted from the proximal side of the sheath 3X is the first. It is possible to prevent the taper portion 26 from being caught. Therefore, the extrudability of the embolic coil 11 in the distal direction can be improved. Further, since the second tapered portion 27 is formed at a steep angle α4 with respect to the first tapered portion 26 (angle α3), the swing range of the embolic coil 11 can be sharply narrowed. Here, the angle α3 is, for example, in the range of 0.02 degrees to 12.00 degrees, more preferably in the range of 0.03 degrees to 9.00 degrees. The angle α4 is, for example, in the range of 0.03 degrees to 15.00 degrees, more preferably in the range of 0.04 degrees to 10.00 degrees, and is larger than α3.

Further, when the embolic coil 11 crosses the distal edge of the second tapered portion 27, the reaction force of the second tapered portion 27 having a larger component in the proximal direction than the reaction force from the first tapered portion 26 is generated. It is no longer applied to the embolic coil 11. Therefore, the tip of the embolic coil 11 can be projected distally. When the embolic coil 11 crosses the distal edge of the second tapered portion 27 in this way, the tip of the embolic coil 11 projects distally and is inserted into the small-diameter second straight portion 8. It will be easier to do. As a result, the embolic coil 11 can be smoothly fed to the distal end of the sheath 3.

Further, the overlapping portion (rigidity) of the wire strands 9a inside and outside in the radial direction with respect to the boundary portion between the second tapered portion 27 and the second straight portion 8 protruding toward the inner diameter side with respect to the axis line 12. The raised portion) may be arranged so as to be offset.
In this way, when the tip of the embolic coil 11 moves from the second tapered portion 27 to the second straight portion 8, deformation of the boundary portion between the second tapered portion 27 and the second straight portion 8 can be allowed. .. Therefore, it is possible to smoothly push out the embolic coil 11 that moves beyond the second tapered portion 27 to the second straight portion 7.

On the other hand, each boundary portion, the boundary portion between the first straight portion 5 and the first tapered portion 26, the boundary portion between the first tapered portion 26 and the second tapered portion 27, or the second tapered portion 27 and the second An overlapping portion (a portion where the rigidity is increased) of the inner and outer wire strands 9a in the radial direction may be arranged at least a part of the boundary portion with the straight portion 8.
By doing so, when the wire wire 9a is wound around the inner layer 4 after the inner layer 4 is formed, the wire wire 9a is not loosened at the above boundary portion, and the wire wire 9a is wound. Can be stabilized.
Further, the boundary portion between the first straight portion 5 and the first tapered portion 26 or the boundary portion between the first tapered portion 26 and the second tapered portion 27, which is recessed on the outer diameter side with respect to the axis 12, is embolized. When the tip of the coil 11 moves, it is possible to prevent the boundary portion from being deformed so as to sink due to the pressing by the embolic coil 11. Therefore, the user can smoothly push the embolic coil 11 beyond the first straight portion 5 to the first tapered portion 26 or beyond the first tapered portion 26 to the second tapered portion 27. ..

In this example, the length of the entire tapered portion is about 100 mm, and the axial length L3 of the first tapered portion 26 and the axial length L4 of the second tapered portion 27 are the same length, but the first The axial length L3 of the tapered portion 26 may be longer than the axial length L4 of the second tapered portion 27.

[Second modification]
Next, the sheath 3Y according to the second modification will be described mainly with reference to FIG. FIG. 4 is an enlarged cross-sectional view showing a portion II of FIG. 1 of the catheter 1 in the sheath 3Y according to the second modification.
The distal lumen (inner layer 34) of the sheath 3Y according to this example further includes a third straight portion 38 extending linearly between the first tapered portion 6 and the second tapered portion 7.
According to the above configuration, since the third straight portion 38 is provided between the first tapered portion 6 and the second tapered portion 7, the diameter of the distal cavity of the sheath 3Y is gradually reduced. Therefore, it is possible to prevent the embolic coil 11 from being caught on the inner wall surface of the inner layer 34.
A straight (non-tapered) third straight portion 38 (non-tapered) is provided between the first tapered portion 26 having a relatively steep slope and the second tapered portion 27 having a relatively gentle slope according to the first modification. An intermediate connecting portion) may be formed.

[Third variant]
The sheath 3Z according to the third modification will be described mainly with reference to FIG. FIG. 5 is an enlarged cross-sectional view showing a portion II of FIG. 1 of the catheter 1 in the sheath 3Z according to the third modification.
The distal lumen (inner layer 44) of the sheath 3Z according to this example further includes a third tapered portion 48 between the second tapered portion 7 and the second straight portion 8.

According to the above configuration, by providing three tapered portions (first tapered portion 6, second tapered portion 7, and third tapered portion 48), the embolic coil 11 and the embolic coil 11 are provided while suppressing the change in the angle of the tapered portion. The contact portion with the tapered portion can be dispersed in the axial direction of the sheath 3Z. Therefore, it is possible to prevent the embolic coil 11 from being caught on the inner wall surface of the inner layer 44. In addition, three or more tapered portions may be provided.

In particular, the angle α5 with respect to the axis 12 in the third tapered portion 48 according to this example is formed to be smaller than the angle α2 with respect to the axis 12 in the second tapered portion 7. Here, the angle α5 is, for example, in the range of 0.01 degrees to 11.00 degrees, more preferably in the range of 0.02 degrees to 8.70 degrees, and is smaller than α2.
Further, in this example, the length of the entire tapered portion is about 100 mm, the axial length L1 of the first tapered portion 6, the axial length L2 of the second tapered portion 7, and the axial length of the third tapered portion 48. L5 is of equal length. However, the present invention is not limited to such a configuration, and the axial length L5 of the third tapered portion 48 is made longer than the axial length L2 of the second tapered portion 7, and the axial length of the second tapered portion 7 is increased. L2 may be longer than the axial length L1 of the first tapered portion 6.
Although the inactive configuration has been described in the present embodiment, the catheter according to the present invention can be flexed by the active configuration (for example, by passing the operation line through the outer layer 10). It may be applied to the one of the configuration).

The above embodiment includes the following technical ideas.
(1) Equipped with a long sheath formed in the air
The distal lumen of the sheath
The first straight part that extends linearly and
A first tapered portion provided on the distal side of the first straight portion and
A second tapered portion provided on the distal side of the first tapered portion,
Includes a second straight portion that is provided distal to the second taper portion and extends linearly.
A catheter characterized in that the inclination ratios of the first tapered portion and the second tapered portion are different.
(2) The catheter according to (1), wherein the second tapered portion is inclined at an angle smaller than that of the first tapered portion with respect to the axis of the sheath.
(3) The catheter according to (1), wherein the first tapered portion is inclined at an angle smaller than that of the second tapered portion with respect to the axis of the sheath.
(4) The lumen of the distal portion of the sheath further includes a third straight portion extending linearly between the first tapered portion and the second tapered portion (1) to (3). The catheter according to any one of the above.
(5) The lumen of the distal portion of the sheath further includes a third tapered portion between the second tapered portion and the second straight portion, according to any one of (1) to (4). The catheter described.

1 Catheter 2 Handle 3, 3X, 3Y, 3Z Sheath 4 Inner layer (chamber)
4a Lumen 5 1st straight part 6 1st tapered part 7 2nd tapered part 8 2nd straight part 9 Wire reinforcing layer 9a Wire wire 10 Outer layer 11 Embolic coil 12 Axis 24 Inner layer 26 1st tapered part 27 2nd tapered part 34 Inner layer 38 3rd straight part 44 Inner layer 48 3rd taper part

Claims (5)

With a long sheath formed in the air,
The distal lumen of the sheath
The first straight part that extends linearly and
A first tapered portion provided on the distal side of the first straight portion and
A second tapered portion provided on the distal side of the first tapered portion,
Includes a second straight portion that is provided distal to the second taper portion and extends linearly.
A catheter characterized in that the inclination ratios of the first tapered portion and the second tapered portion are different. The catheter according to claim 1, wherein the second tapered portion is inclined at an angle smaller than that of the first tapered portion with respect to the axis of the sheath. The catheter according to claim 1, wherein the first tapered portion is inclined at an angle smaller than that of the second tapered portion with respect to the axis of the sheath. Any one of claims 1 to 3, wherein the lumen of the distal portion of the sheath further includes a third straight portion extending linearly between the first tapered portion and the second tapered portion. The catheter described in. The catheter according to any one of claims 1 to 4, wherein the lumen of the distal portion of the sheath further includes a third tapered portion between the second tapered portion and the second straight portion.

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