WO2025205144A1 - Catheter - Google Patents

Abstract

This catheter (100) includes: a distal end member (20) that is provided with a first shaft (10) and an elongated section (35) that has an X-ray opaque section (25); a second shaft (50); and a balloon (60) that has a main body section (61) that expands and contracts in a radial direction (y) of the first shaft (10) and can adjust a protruding length of the main body section (61) from the first shaft (10) according to a length of a lesion section of a patient. At least a portion of the elongated section (35) is disposed further to a distal side than a distal end (10d) of the first shaft (10), and a distal end of the elongated section (35) is movable outward in the radial direction (y) of the first shaft (10) by expansion of the balloon (60).

Description

catheter

The present invention relates to a catheter.

Catheters have been developed that are equipped with an expansion member that can adjust the length of the portion that expands outside the sheath to match the length of the lesion by adjusting the length of the portion that protrudes from the sheath. Such catheters can be used to treat lesions by adjusting the length of the portion that expands outside the sheath to match the length of the lesion.

For example, Patent Document 1 discloses a catheter assembly having a sheath with an expansion member disposed therein and a flexible distal tip.

Patent document 2 discloses a catheter having an outer sleeve with a balloon disposed therein and a flexible distal end.

Patent document 3 discloses a catheter having an outer sheath with an expansion member disposed therein and a flexible distal end.

U.S. Patent No. 6,884,257 U.S. Pat. No. 5,961,536 Special Publication No. 2010-527695

However, with catheters such as those described in Patent Documents 1 to 3, it is difficult to visually confirm the shape of the proximal end of the balloon portion that expands outside the sheath, even under X-ray fluoroscopy. This can make it difficult to adjust the length of the portion that expands outside the sheath to match the length of the lesion, or to properly position the portion that expands outside the sheath at the lesion, which can result in damage to normal tissue when treatment is performed on areas other than the lesion.

The present invention was made in consideration of the above circumstances, and its purpose is to provide a catheter that can more easily prevent damage to normal tissue when treatment is performed on areas other than the lesion.

A catheter according to one embodiment of the present invention is as follows.
[1] A first shaft having a longitudinal direction and a radial direction and an inner cavity extending in the longitudinal direction;
a tip member connected to the distal end of the first shaft, having an inner lumen communicating with the inner lumen of the first shaft, and including an elongated portion extending in the longitudinal direction and having a radiopaque portion;
a second shaft disposed in the lumen of the first shaft and the lumen of the tip member and adapted to move in the longitudinal direction relative to the first shaft;
a balloon disposed at a distal portion of the second shaft, the balloon having a main body portion that expands and contracts in the radial direction, and a protruding length of the main body portion from the first shaft that can be adjusted depending on the length of a lesion in a patient;
At least a portion of the elongated portion is disposed distal to the distal end of the first shaft,
A catheter in which the distal end of the elongated portion is movable radially outward by expansion of the balloon.

By expanding the balloon, the distal end of the elongated portion moves radially outward from the first shaft, allowing the elongated portion to more easily conform to the shape of the proximal end of the main body portion expanding outside the first shaft. Because the elongated portion has an X-ray opaque portion, the shape of the proximal end of the main body portion expanding outside the first shaft can be easily visualized under X-ray fluoroscopy. This makes it easier to adjust the length of the main body portion expanding outside the first shaft to the length of the lesion, and to appropriately position the main body portion expanding outside the first shaft at the lesion. This makes it easier to prevent damage to normal tissue caused by treatment being performed on areas other than the lesion.

The catheter according to the embodiment of the present invention is preferably any one of the following [2] to [14].
[2] The catheter according to [1], wherein the tip member has a fixed portion at its proximal portion, the inner diameter of which does not expand due to the expansion of the balloon, and which is fixed to the first shaft.
[3] The catheter according to [1] or [2], wherein the tip member is disposed radially outward of the elongated portion and has an outer membrane made of a material having lower rigidity than the material constituting the elongated portion.
[4] When the balloon is inflated, the portion of the main body protruding from the first shaft has a straight tube portion, a distal tapered portion located distal to the straight tube portion, and a proximal tapered portion located proximal to the straight tube portion,
The catheter according to any one of [1] to [3], wherein the elongated portion has an abutment portion that abuts against the straight tube portion when the balloon is in an expanded state.
[5] The catheter according to any one of [1] to [4], wherein the first shaft has a protrusion protruding radially inward.
[6] The catheter according to any one of [1] to [5], wherein the elongated portion is made of a material containing a shape-memory material.
[7] A catheter described in any one of [1] to [6], wherein the length of the distal end of the elongated portion in the circumferential direction of the first shaft is longer than the length of the proximal end of the elongated portion in the circumferential direction of the first shaft.
[8] A catheter described in any one of [1] to [6], wherein the length of the proximal end of the elongated portion in the circumferential direction of the first shaft is longer than the length of the distal end of the elongated portion in the circumferential direction of the first shaft.
[9] The catheter according to any one of [1] to [8], wherein the tip member comprises a slit tube having a slit extending from the distal end toward the proximal side.
[10] The catheter according to [9], wherein the number of the slits present in the distal portion of the slit tube is greater than the number of the slits present in the proximal portion of the slit tube.
[11] A catheter according to [9] or [10], wherein the length of the proximal end of the slit in the circumferential direction of the first shaft is longer than the length of the distal end of the slit in the circumferential direction of the first shaft.
[12] The tip member includes a plurality of the elongated portions,
the plurality of elongated portions include a first elongated portion and a second elongated portion;
The catheter according to any one of [1] to [11], wherein the second elongated portion is located radially outward of the first elongated portion when the balloon is deflated.
[13] An inner diameter of a portion of the first shaft when the balloon is in an expanded state is larger than an inner diameter of the portion of the first shaft when the balloon is in a deflated state,
The catheter according to [2], wherein the inner diameter of the fixing portion when the balloon is inflated is smaller than the inner diameter of the portion of the first shaft when the balloon is inflated.
[14] The first shaft has an outer layer and an inner layer located radially inward of the outer layer,
The catheter according to [13], wherein the inner layer is made of a material having a lower hardness than the outer layer.

A catheter according to one embodiment of the present invention is as follows.
[15] A first shaft having a longitudinal direction and a radial direction and an inner lumen extending in the longitudinal direction;
a tip member connected to the distal end of the first shaft, having an inner lumen communicating with the inner lumen of the first shaft, and including an elongated portion extending in the longitudinal direction and having a radiopaque portion;
a second shaft disposed in the lumen of the first shaft and the lumen of the tip member and adapted to move in the longitudinal direction relative to the first shaft;
a balloon disposed at a distal portion of the second shaft, the balloon having a main body portion that expands and contracts in the radial direction, and a protruding length of the main body portion from the first shaft that can be adjusted depending on the length of a lesion in a patient;
the balloon has a protrusion protruding outward in the radial direction from the main body portion,
At least a portion of the elongated portion is disposed distal to the distal end of the first shaft,
A catheter in which the distal end of the elongated portion is movable radially outward by expansion of the balloon.

By expanding the balloon, the distal end of the elongated portion moves radially outward from the first shaft, allowing the elongated portion to more easily conform to the shape of the proximal end of the main body portion expanding outside the first shaft. Because the elongated portion has an X-ray opaque portion, the shape of the proximal end of the main body portion expanding outside the first shaft can be easily visualized under X-ray fluoroscopy. This makes it easier to adjust the length of the main body portion expanding outside the first shaft to the length of the lesion, and to appropriately position the main body portion expanding outside the first shaft at the lesion. This makes it easier to prevent damage to normal tissue caused by treatment being performed on areas other than the lesion.

The catheter according to the embodiment of the present invention is preferably any one of the following [16] to [31].
[16] The catheter according to [15], wherein the tip member has a fixed portion at its proximal portion, the inner diameter of which does not expand due to the expansion of the balloon, and which is fixed to the first shaft.
[17] The catheter according to [15] or [16], wherein the tip member is disposed radially outward of the elongated portion and has an outer membrane made of a material having lower rigidity than the material constituting the elongated portion.
[18] When the balloon is in an expanded state, the portion of the main body protruding from the first shaft has a straight tube portion, a distal tapered portion located distal to the straight tube portion, and a proximal tapered portion located proximal to the straight tube portion,
The catheter according to any one of [15] to [17], wherein the elongated portion has an abutment portion that abuts against the straight tube portion when the balloon is in an expanded state.
[19] The catheter according to any one of [15] to [18], wherein the tip member comprises a slit tube provided with a slit extending from the distal end toward the proximal side.
[20] The catheter according to [19], wherein the number of the slits is the same as the number of the convex portions of the balloon.
[21] The catheter according to any one of [15] to [20], wherein the convex portion and the elongated portion of the balloon do not abut on each other when the balloon is in an expanded state.
[22] The catheter according to any one of [15] to [21], wherein the convex portion and the main body portion of the balloon are integrally molded.
[23] The catheter according to any one of [15] to [22], wherein the first shaft has a protrusion protruding radially inward.
[24] The catheter according to any one of [15] to [23], wherein the elongated portion is made of a material containing a shape-memory material.
[25] A catheter according to any one of [15] to [24], wherein the length of the distal end of the elongated portion in the circumferential direction of the first shaft is longer than the length of the proximal end of the elongated portion in the circumferential direction of the first shaft.
[26] A catheter according to any one of [15] to [24], wherein the length of the proximal end of the elongated portion in the circumferential direction of the first shaft is longer than the length of the distal end of the elongated portion in the circumferential direction of the first shaft.
[27] The catheter according to [19] or [20], wherein the number of the slits present in the distal portion of the slit tube is greater than the number of the slits present in the proximal portion of the slit tube.
[28] A catheter according to [19] or [20], wherein the length of the proximal end of the slit in the circumferential direction of the first shaft is longer than the length of the distal end of the slit in the circumferential direction of the first shaft.
[29] The tip member includes a plurality of the elongated portions,
the plurality of elongated portions include a first elongated portion and a second elongated portion;
The catheter according to any one of [15] to [28], wherein the second elongated portion is located radially outward of the first elongated portion when the balloon is deflated.
[30] An inner diameter of a portion of the first shaft when the balloon is in an expanded state is larger than an inner diameter of the portion of the first shaft when the balloon is in a deflated state,
The catheter according to [16], wherein the inner diameter of the fixing part when the balloon is inflated is smaller than the inner diameter of the part of the first shaft when the balloon is inflated.
[31] The first shaft has an outer layer and an inner layer located radially inward of the outer layer,
The catheter according to [30], wherein the inner layer is made of a material having a lower hardness than the outer layer.

The catheter of the present invention can help prevent damage to normal tissue caused by treatment being performed on areas other than the lesion.

FIG. 1 shows a side view of a catheter according to an embodiment of the present invention. FIG. 2 shows an enlarged cross-sectional view (partial side view) of the distal portion of the catheter shown in FIG. FIG. 3 is a cross-sectional view (partial side view) of the catheter shown in FIG. 2, showing a state in which a portion of the main body is expanded outside the first shaft. FIG. 4 is a cross-sectional view (partial side view) showing a modification of the catheter shown in FIG. FIG. 5 is a cross-sectional view (partial side view) showing a modification of the catheter shown in FIG. FIG. 6 is a cross-sectional view (partial side view) of the catheter shown in FIG. 5, showing a state in which a portion of the main body is expanded outside the first shaft. FIG. 7 is a cross-sectional view (partial side view) showing a modification of the catheter shown in FIG. FIG. 8 is a side view showing a modified example of the tip member. FIG. 9 is a side view showing a modified example of the tip member. FIG. 10 is a side view showing a modified example of the tip member. FIG. 11 is a side view showing a modified example of the tip member. FIG. 12 is a side view showing a modified example of the tip member. FIG. 13 is a cross-sectional end view taken along line XIII-XIII shown in FIG. FIG. 14 shows a cutaway end view of a modification of the tip member shown in FIG. FIG. 15 shows a cutaway end view of a modification of the tip member shown in FIG. FIG. 16 shows a side view of a catheter according to an embodiment of the present invention. FIG. 17 shows an enlarged cross-sectional view (partial side view) of the distal portion of the catheter shown in FIG. FIG. 18 is a cross-sectional view (partial side view) of the catheter shown in FIG. 17, showing a state in which a portion of the main body is expanded outside the first shaft. FIG. 19 is a cross-sectional view (partial side view) showing a modification of the catheter shown in FIG. FIG. 20 is a cross-sectional view (partial side view) showing a modification of the catheter shown in FIG. FIG. 21 is a cross-sectional view (partial side view) of the catheter shown in FIG. 20, showing a state in which a portion of the main body is expanded outside the first shaft. FIG. 22 is a cross-sectional view (partial side view) showing a modification of the catheter shown in FIG. FIG. 23 is a side view showing a modified example of the tip member. FIG. 24 is a side view showing a modified example of the tip member. FIG. 25 is a side view showing a modified example of the tip member. FIG. 26 is a side view showing a modified example of the tip member. FIG. 27 is a side view showing a modified example of the tip member. FIG. 28 is a cross-sectional end view taken along line XIII-XIII shown in FIG. FIG. 29 shows a cutaway end view of a modification of the tip member shown in FIG. FIG. 30 shows a cutaway end view of a modification of the tip member shown in FIG. FIG. 31 is a cross-sectional end view taken along line XVI-XVI shown in FIG.

The present invention will be explained in detail below with reference to the drawings, but of course the present invention is not limited to the illustrated examples and can be implemented with appropriate modifications within the scope of the above and below-mentioned intent, all of which are encompassed within the technical scope of the present invention. Hatching, symbols, etc. may be omitted in each drawing for convenience; in such cases, reference should be made to the specification or other drawings. Furthermore, the dimensions of various parts in the drawings may differ from their actual dimensions, as priority is given to aiding understanding of the features of the present invention.

(Embodiment 1)

A catheter according to one embodiment of the present invention comprises a first shaft having a longitudinal and radial direction and a lumen extending in the longitudinal direction; a tip member connected to the distal end of the first shaft, having a lumen communicating with the lumen of the first shaft, and including an elongated portion extending in the longitudinal direction of the first shaft and having an X-ray opaque portion; a second shaft disposed in the lumen of the first shaft and the lumen of the tip member and moving in the longitudinal direction of the first shaft relative to the first shaft; and a balloon disposed in the distal portion of the second shaft, having a main body portion that expands and contracts in the radial direction of the first shaft, the length of which protrudes from the first shaft being adjustable depending on the length of the patient's lesion; and the gist of the catheter is that at least a portion of the elongated portion is disposed distal to the distal end of the first shaft, and the distal end of the elongated portion is movable radially outward of the first shaft by expansion of the balloon.

The overall configuration of a catheter 100 according to an embodiment of the present invention will be described with reference to Figures 1 to 15. These figures show a catheter 100 comprising a first shaft 10, a tip member 20, a second shaft 50, and a balloon 60. The first shaft 10 has a longitudinal direction x, a radial direction y, and a circumferential direction c.

The components and parts of the catheter 100 other than the first shaft 10 also have longitudinal, radial, and circumferential directions. The longitudinal, radial, and circumferential directions of the components and parts of the catheter 100 other than the first shaft 10 may or may not match the longitudinal direction x, radial direction y, and circumferential direction c of the first shaft 10. For ease of understanding, this specification shows a configuration in which the longitudinal, radial, and circumferential directions of all components and parts match the longitudinal direction x, radial direction y, and circumferential direction c of the first shaft 10, respectively.

In this specification, the proximal side refers to the direction toward the user's hand in the longitudinal direction x of the first shaft 10, and the distal side refers to the opposite side of the proximal side, i.e., the direction toward the treatment target. Furthermore, when each member or part is divided into two equal parts in the longitudinal direction x of the first shaft 10, the part of each member or part located on the distal side is referred to as the distal part of each member or part, and the part of each member or part located on the proximal side is referred to as the proximal part of each member or part. The distal end of each member or part is the end located most distally of each member or part. The proximal end of each member or part is the end located most proximal of each member or part. The end includes the peripheral portion of the end. In other words, the distal end refers to the distal end and the peripheral portion of the distal end, and the proximal end refers to the proximal end and the peripheral portion of the proximal end.

1 shows a side view of a catheter according to an embodiment of the present invention. FIG. 2 shows an enlarged cross-sectional view (partial side view) of the distal portion of the catheter shown in FIG. 1. FIG. 3 shows a cross-sectional view (partial side view) of the catheter shown in FIG. 2, showing a state in which a portion of the main body is expanded outside the first shaft. FIG. 4 shows a cross-sectional view (partial side view) of a modified example of the catheter shown in FIG. 3. FIG. 5 shows a cross-sectional view (partial side view) of a modified example of the catheter shown in FIG. 2. FIG. 6 shows a cross-sectional view (partial side view) of the catheter shown in FIG. 5, showing a state in which a portion of the main body is expanded outside the first shaft. FIG. 7 shows a cross-sectional view (partial side view) of a modified example of the catheter shown in FIG. 3. More specifically, FIGS. 2 to 7 show cross sections passing through the central axis of the first shaft and parallel to the longitudinal direction of the first shaft. FIGS. 8 to 12 show side views of modified examples of the tip member. FIG. 13 shows an end view of a cross section taken along line XIII-XIII shown in FIG. 2. Figures 14 and 15 are cross-sectional end views showing modified versions of the tip member shown in Figure 13.

As shown in Figures 1 to 7, the catheter 100 comprises a first shaft 10, a tip member 20, a second shaft 50, and a balloon 60.

As shown in Figures 2 to 7, the first shaft 10 has a longitudinal direction x and a radial direction y, and has an inner lumen 10a extending in the longitudinal direction x. The first shaft 10 may have an inner surface 10b facing the inner lumen 10a and an outer surface 10c facing the outside of the first shaft 10. Furthermore, the first shaft 10 preferably has a distal end 10d and a proximal end.

As shown in Figures 1 to 12, the tip member 20 is connected to the distal end of the first shaft 10 and has a lumen 20a that communicates with the lumen 10a of the first shaft 10. The tip member 20 may have an inner surface 20b facing the lumen 20a and an outer surface 20c facing the exterior of the tip member 20. The lumen 20a of the tip member 20 preferably extends in the longitudinal direction x of the first shaft 10. Furthermore, the tip member 20 preferably has a distal end 20d and a proximal end 20e.

The tip member 20 has an elongated portion 35 extending in the longitudinal direction x of the first shaft 10. The elongated portion 35 has an X-ray opaque portion 25.

As shown in FIG. 12, the radiopaque portion 25 may be formed by forming only a portion of the elongated portion 35 from a material containing a radiopaque substance. As shown in FIG. 2, the radiopaque portion 25 may be formed by forming the entire elongated portion 35 from a material containing a radiopaque substance.

As shown in Figures 2 to 7, the second shaft 50 is disposed in the inner cavity 10a of the first shaft 10 and the inner cavity 20a of the tip member 20, and moves relative to the first shaft 10 in the longitudinal direction x of the first shaft 10.

As shown in Figures 2 to 7, the balloon 60 is disposed at the distal portion of the second shaft 50 and has a main body 61 that expands and contracts in the radial direction y of the first shaft 10, and the length of the main body 61 protruding from the first shaft 10 can be adjusted depending on the length of the patient's lesion. More specifically, it is preferable that the length of the main body 61 protruding from the first shaft 10 can be adjusted by moving the second shaft 50 relative to the first shaft 10 in the longitudinal direction x of the first shaft 10.

As shown in Figures 2 to 7, at least a portion of the elongated portion 35 is disposed distal to the distal end 10d of the first shaft 10. The entire elongated portion 35 may be disposed distal to the distal end 10d of the first shaft 10. Although not shown, only a portion of the elongated portion 35 may be disposed distal to the distal end 10d of the first shaft 10, with the remaining portion of the elongated portion 35 being disposed proximal to the distal end 10d of the first shaft 10.

The distal end of the elongated portion 35 is movable outward in the radial direction y of the first shaft 10 due to the expansion of the balloon 60. Figures 2 and 5 show the balloon 60 in a deflated state. Figures 3, 4, 6, and 7 show the balloon 60 in an expanded state, with the distal end of the elongated portion 35 having moved outward in the radial direction y of the first shaft 10. A portion of the elongated portion 35 may be movable outward in the radial direction y of the first shaft 10, or the entire elongated portion 35 may be movable outward in the radial direction y of the first shaft 10.

As shown in Figures 2 to 7, expansion of the balloon 60 moves the distal end of the elongated portion 35 outward in the radial direction y of the first shaft 10, allowing the elongated portion 35 to more easily conform to the shape of the proximal end of the main body portion 61 expanding outside the first shaft 10. Because the elongated portion 35 has an X-ray opaque portion 25, the shape of the proximal end of the main body portion 61 expanding outside the first shaft 10 can be easily visualized under X-ray fluoroscopy. This makes it easy to adjust the length of the main body portion 61 expanding outside the first shaft 10 to the length of the lesion, and to appropriately position the main body portion 61 expanding outside the first shaft 10 at the lesion. This makes it easier to prevent damage to normal tissue caused by treatment being performed on areas other than the lesion.

The catheter 100 can be used, for example, by inserting the distal end of the first shaft 10 to the lesion, and then protruding a portion of the main body 61 of the balloon 60 disposed in the lumen 10a of the first shaft 10 and the lumen 20a of the tip member 20 from the first shaft 10. By expanding the balloon 60 while leaving a portion of the main body 61 protruding from the first shaft 10, it becomes easy to adjust the length of the main body 61 expanding outside the first shaft 10 to the length of the lesion. When a guidewire 1 is used, the guidewire 1 is placed in the body cavity, and then the distal end of the first shaft 10 is inserted to the lesion.

As shown in FIG. 7, the first shaft 10 preferably has a protrusion 14 that protrudes inward in the radial direction y of the first shaft 10. With this configuration, when the balloon 60 is inflated with a portion of the main body 61 protruding from the first shaft 10, the protrusion 14 bites into the balloon 60, making it easier to suppress movement of the balloon 60 in the longitudinal direction x of the first shaft 10.

The first shaft 10 may have only one protrusion 14, but may also have multiple protrusions 14.

A single protrusion 14 may be elongated and extend in the longitudinal direction x of the first shaft 10, but is preferably elongated and extend in the circumferential direction c of the first shaft 10. A single protrusion 14 may be elongated and extend spirally so as to wind around the second shaft 50. A single protrusion 14 may also be columnar, polygonal pyramidal, polygonal truncated pyramidal, conical, truncated conical, or hemispherical, and multiple protrusions 14 having these shapes may be scattered.

The proximal end of the tip member 20 may be connected to the distal end of the first shaft 10. The proximal end 20e of the tip member 20 may be connected to the distal end 10d of the first shaft 10. The proximal end of the tip member 20 may be fixed to the distal end of the first shaft 10. The proximal end 20e of the tip member 20 may be fixed to the distal end 10d of the first shaft 10.

The tip member 20 may have a tapered portion in which the outer diameter decreases toward the distal end when the balloon 60 is deflated, i.e., in its natural state. The tip member 20 may have a straight tube portion in which the outer diameter is constant when the balloon 60 is deflated, i.e., in its natural state.

The tip member 20 may be made of a material including resin or metal.

As shown in Figures 1 to 12, the tip member 20 preferably has a fixing portion 22 in its proximal portion. The fixing portion 22 is preferably a portion whose inner diameter does not expand when the balloon 60 is expanded. Furthermore, the fixing portion 22 preferably has a portion that is fixed to the first shaft 10. It is preferable that at least a portion of the fixing portion 22 is fixed to the first shaft 10 in the longitudinal direction x of the first shaft 10. That is, only a portion of the fixing portion 22 may be fixed to the first shaft 10 in the longitudinal direction x of the first shaft 10, or the entire fixing portion 22 may be fixed to the first shaft 10 in the longitudinal direction x of the first shaft 10. Since the inner diameter of the fixing portion 22 does not expand when the balloon 60 is expanded, the tip member 20 is less likely to come off the first shaft 10.

It is preferable that the proximal end of the fixing portion 22 is fixed to the distal end of the first shaft 10. The proximal end of the fixing portion 22 may also be fixed to the distal end 10d of the first shaft 10. The distal end of the first shaft 10 may be inserted into the inner cavity of the fixing portion 22, and the inner surface of the fixing portion 22 may be fixed to the outer surface 10c of the first shaft 10. The fixing portion 22 may also be inserted into the inner cavity 10a of the first shaft 10, and the inner surface 10b of the first shaft 10 and the outer surface of the fixing portion 22 may be fixed.

The tip member 20 preferably has multiple elongated portions 35. Each elongated portion 35 changes shape in accordance with the deformation of the balloon 60 due to its expansion, making it easier to express the shape of the proximal end of the main body portion 61 expanding outside the first shaft 10.

The tip member 20 may be composed of multiple members, or may be composed of a single member. For example, as shown in Figure 3, the tip member 20 may include a plate-shaped member 38 and a ring-shaped member 39, with the proximal portion of the plate-shaped member 38 located in the inner cavity of the ring-shaped member 39. As shown in Figures 10 and 11, the tip member 20 may include a slit tube 36 having a slit 37 extending from the distal end 20d toward the proximal side. It is preferable to provide multiple slits 37.

The elongated portion 35 is preferably made of a material containing a shape memory material. A shape memory material is a material that has the ability to remember its shape. Examples of shape memory materials that can be used include metals such as stainless steels such as SUS304 and SUS316, platinum, nickel, cobalt, chromium, titanium, tungsten, aluminum, gold, silver, Ni-Ti alloys, and Co-Cr alloys, as well as resins such as norbornene-based polymers, trans-polyisoprene-based polymers, styrene-butadiene-based copolymers, polyurethane-based polymers, polyester-based polymers, polyolefin-based polymers, and acrylic-based polymers.

The distal end of the elongated portion 35 preferably has rounded edges, either by being rounded or by being spherically processed as shown in Figure 12. By processing the distal end of the elongated portion 35 in this manner, it is possible to more easily prevent damage to blood vessels when the distal end of the elongated portion 35 comes into contact with the blood vessels. Furthermore, as shown in Figure 12, the spherically processed portion at the distal end of the elongated portion 35 may be formed from a material containing an X-ray opaque substance, thereby constituting the X-ray opaque portion 25.

8 and 10, the length of the distal end of the elongated portion 35 in the circumferential direction c of the first shaft 10 may be longer than the length of the proximal end of the elongated portion 35 in the circumferential direction c of the first shaft 10. By making the length of the distal end of the elongated portion 35 in the circumferential direction c of the first shaft 10 relatively long, the visibility of the distal end of the elongated portion 35 under X-ray fluoroscopy is improved, making it easier to improve the visibility of the shape of the proximal end of the main body portion 61 expanding outside the first shaft 10. Furthermore, by making the length of the proximal end of the elongated portion 35 in the circumferential direction c of the first shaft 10 relatively short, the rigidity of the proximal end of the elongated portion 35 is reduced. Therefore, the distal end of the elongated portion 35 is more likely to move outward in the radial direction y of the first shaft 10 due to the expansion of the balloon 60.

As shown in FIG. 9 , the length of the proximal end of the elongated portion 35 in the circumferential direction c of the first shaft 10 may be longer than the length of the distal end of the elongated portion 35 in the circumferential direction c of the first shaft 10. By making the length of the distal end of the elongated portion 35 in the circumferential direction c of the first shaft 10 relatively short, the rigidity of the distal end of the elongated portion 35 is reduced. This makes it easier for the distal end of the elongated portion 35 to follow the deformation of the balloon 60 due to the expansion of the balloon 60.

As shown in FIG. 11, it is preferable that the number of slits 37 present in the distal portion 36a of the slit tube 36 is greater than the number of slits 37 present in the proximal portion 36b of the slit tube 36. This configuration tends to reduce the rigidity of the distal portion 36a of the slit tube 36. As a result, the distal end of the elongated portion 35 tends to move outward in the radial direction y of the first shaft 10 due to the expansion of the balloon 60, and the elongated portion 35 tends to conform to the shape of the proximal end of the main body portion 61 expanding outside the first shaft 10.

As shown in FIG. 10 , the length of the proximal end of the slit 37 in the circumferential direction c of the first shaft 10 is preferably longer than the length of the distal end of the slit 37 in the circumferential direction c of the first shaft 10. By making the length of the proximal end of the slit 37 in the circumferential direction c of the first shaft 10 relatively long, the proximal ends of adjacent elongated portions 35 are less likely to come into contact with each other. This makes it easier for the distal ends of the elongated portions 35 to move outward in the radial direction y of the first shaft 10 when the balloon 60 is expanded.

As shown in Figures 13, 14, and 15, the multiple long portions 35 may include a first long portion 351 and a second long portion 352. The multiple long portions 35 may further include a third long portion 353, a fourth long portion 354, a fifth long portion 355, and a sixth long portion 356. The multiple long portions 35 may be aligned in the circumferential direction c of the first shaft 10.

As shown in Figures 14 and 15, one elongated portion 35 is preferably configured to be located further outward in the radial direction y of the first shaft 10 than the other elongated portions 35. More specifically, when the balloon 60 is deflated, the second elongated portion 352 is preferably located further outward in the radial direction y of the first shaft 10 than the first elongated portion 351. This configuration makes it possible to increase the length of the distal end of the elongated portion 35 in the circumferential direction c of the first shaft 10 while making it easier to reduce the outer diameter of the tip member 20. This improves the visibility of the shape of the proximal end of the main body portion 61 expanding outside the first shaft 10 under X-ray fluoroscopy, while making it easier to reduce the diameter of the tip member 20. Note that when the balloon 60 is deflated, one elongated portion 35 may not be configured to be located further outward in the radial direction y of the first shaft 10 than the other elongated portions 35.

As shown in FIG. 4, the tip member 20 may have an outer membrane 23 that is disposed outward in the radial direction y of the first shaft 10 from the elongated portion 35 and is made of a material with lower rigidity than the material that makes up the elongated portion 35. The elongated portion 35 may be partially or entirely embedded in the outer membrane 23. This makes it possible to prevent tissue damage that would occur if the elongated portion 35 came into direct contact with the tissue.

The outer membrane 23 is preferably cylindrical, with the elongated portion 35 disposed within its lumen. The distal end of the elongated portion 35 is preferably located proximal to the distal end of the outer membrane 23. It is more preferable that the entire elongated portion 35 be disposed within the lumen of the cylindrical outer membrane 23.

The outer membrane 23 can be made from any of the materials exemplified below as materials that can be used to make the balloon 60.

The radiopaque portion 25 can be made of a material containing a radiopaque substance, such as lead, barium, iodine, tungsten, gold, platinum, iridium, stainless steel, titanium, or a cobalt-chromium alloy. The entire radiopaque portion 25 may be made of a radiopaque substance alone. The radiopaque portion 25 may also be made of a combination of a radiopaque substance and another material.

The radiopaque portion 25 may contain particles containing the radiopaque material described above. The particles containing the radiopaque material may be composed entirely of the radiopaque material, or only partially of the radiopaque material. The particles containing the radiopaque material are preferably composed of the radiopaque material and a dispersant. Examples of dispersants that may be used to form the particles containing the radiopaque material include resin dispersants such as polyamide resin, polyester resin, polyurethane resin, and polyolefin resin, organic salt dispersants such as magnesium stearate, and inorganic dispersants such as talc. The elongated portion 35 may be formed from a base resin in which particles containing the radiopaque material described above are mixed. Examples of base resins that can be used include polyamide resin, polyester resin, polyurethane resin, polyolefin resin, vinyl chloride resin, silicone resin, natural rubber, and fluororesin.

The second shaft 50 can be configured to have an inner cavity extending in the longitudinal direction x of the first shaft 10. As can be seen from Figures 2 to 7, the inner cavity of the second shaft 50 can be used as a passage for inserting the guide wire 1, etc.

As shown in Figures 2 to 7, the second shaft 50 may have a second inner shaft 51 and a second outer shaft 52. The second outer shaft 52 has an inner lumen and is preferably disposed in the inner lumen 10a of the first shaft 10. The second inner shaft 51 has an inner lumen in which the guide wire 1 is disposed and is preferably disposed in the inner lumen of the second outer shaft 52.

The second outer shaft 52 is preferably connected to an indeflator that injects fluid to be supplied inside the balloon 60.

It is preferable that the first shaft 10 and the second shaft 50 are flexible. This makes it easier to deform the first shaft 10 and the second shaft 50 to fit the shape of the body cavity. In addition, it is preferable that the first shaft 10 and the second shaft 50 have elasticity in order to maintain their shape.

The shape of the first shaft 10 and the second shaft 50 can be, for example, a hollow cylinder, a hollow polygonal prism, etc.

The first shaft 10 and the second shaft 50 can be, for example, a hollow body formed by arranging one or more wires in a predetermined pattern; a hollow body with a resin coating on at least one of the inner and outer surfaces; a resin tube; or a combination of these, such as a combination of these connected in the longitudinal direction. Examples of hollow bodies with wires arranged in a predetermined pattern include tubular bodies with a mesh structure formed by crossing or weaving wires, and coils with wound wires. The wires may be one or more solid wires or one or more twisted wires. Resin tubes can be manufactured by extrusion molding, for example. When the first shaft 10 and the second shaft 50 are resin tubes, the first shaft 10 and the second shaft 50 can be constructed from a single layer or multiple layers. The first shaft 10 and the second shaft 50 may be constructed from a single layer in a portion of the longitudinal direction x or circumferential direction c of the first shaft 10, and the other portion may be constructed from multiple layers.

The first shaft 10 and the second shaft 50 can be made of synthetic resins such as polyolefin resins (e.g., polyethylene and polypropylene), polyamide resins (e.g., nylon), polyester resins (e.g., PET), aromatic polyether ketone resins (e.g., PEEK), polyether polyamide resins, polyurethane resins, polyimide resins, and fluororesins (e.g., PTFE, PFA, and ETFE), or metals such as stainless steel, carbon steel, and nickel-titanium alloys. These may be used alone or in combination of two or more types. The first shaft 10 and the second shaft 50 may be made of the same material, or may be made of different materials.

The outer diameter of the first shaft 10 can be, for example, 1.0 mm or more, 1.1 mm or more, 1.2 mm or more, etc. The outer diameter of the first shaft 10 can also be, for example, 5.0 mm or less, 4.0 mm or less, 3.0 mm or less, etc., but is preferably 2.0 mm or less.

The inner diameter of the first shaft 10 can be, for example, 4.0 mm or less, 3.8 mm or less, 3.5 mm or less, etc. The inner diameter of the first shaft 10 can also be, for example, 0.4 mm or more, 0.5 mm or more, 0.6 mm or more, etc., but is preferably 0.8 mm or more, and more preferably 1.2 mm or more. It is also preferable that the inner diameter of the first shaft 10 is large enough to allow the second shaft 50 to pass through.

The balloon 60 is preferably made of resin. Resins that can be used to make the balloon 60 include polyamide resin, polyester resin, polyurethane resin, polyolefin resin, vinyl chloride resin, silicone resin, and natural rubber. These can be used alone or in combination of two or more. Of these, polyamide resin, polyester resin, and polyurethane resin are preferred. Elastomer resin can be used to make the balloon 60 thinner and more flexible.

The balloon 60 may have a distal sleeve portion 64 fixed to the second inner shaft 51 and a proximal sleeve portion 65 fixed to the second outer shaft 52.

As shown in Figures 3, 4, 6, and 7, when the balloon 60 is inflated, the main body 61 preferably has a portion 62 protruding from the first shaft 10 and a portion 63 located in the lumen 10a of the first shaft 10. When the balloon 60 is inflated, the portion 62 of the main body 61 protruding from the first shaft 10 preferably has a straight tube portion 62b, a distal tapered portion 62a located distal to the straight tube portion 62b, and a proximal tapered portion 62c located proximal to the straight tube portion 62b. The above-described configuration of the balloon 60 makes it easier for the straight tube portion 62b to come into contact with the lesion.

As shown in Figure 3, when the balloon 60 is inflated, the elongated portion 35 preferably has an abutment portion 24 that abuts the straight tube portion 62b. This makes it easier to visualize the proximal end of the straight tube portion 62b, which is likely to abut the lesion.

The abutment portion 24 is preferably arranged so that it is parallel to the longitudinal direction of the balloon 60, the longitudinal direction x of the first shaft 10, the longitudinal direction of the second shaft 50, etc. Note that "parallel" here includes strict parallelism up to ±10°.

5 and 6, it is preferable that the inner diameter of a portion of the first shaft 10 when the balloon 60 is inflated is larger than the inner diameter of the portion of the first shaft 10 when the balloon 60 is inflated, and the inner diameter of the fixing portion 22 when the balloon 60 is inflated is smaller than the inner diameter of the portion of the first shaft 10 when the balloon 60 is inflated. This configuration makes it easier to suppress movement of the balloon 60 in the longitudinal direction x of the first shaft 10 when the balloon 60 is inflated with a portion of the main body 61 protruding from the first shaft 10. For example, this can be implemented by having the first shaft 10 have an outer layer 15 and an inner layer 16 located inward of the outer layer 15 in the radial direction y of the first shaft 10, and the inner layer 16 being made of a material with a lower hardness than the outer layer 15. Hardness can be measured by measuring the repulsive force during compression, measuring the elastic modulus using a scanning probe microscope (SPM), measuring Rockwell hardness, or measuring Shore hardness, but it is preferably measured by measuring Shore hardness.

The length from the distal end to the proximal end of the catheter 100 can be, for example, 200 mm or more, 250 mm or more, 300 mm or more, etc. The length from the distal end to the proximal end of the catheter 100 can also be, for example, 2500 mm or less, 2450 mm or less, 2400 mm or less, etc.

As shown in FIG. 1, a hub 70 may be connected to the proximal portion of the first shaft 10. The first shaft 10 and the hub 70 may be fixed together. For example, the first shaft 10 and the hub 70 can be fixed together by adhesive bonding, welding, screws, etc.

FIG. 1 discloses an embodiment in which a guidewire port 13 is formed midway from the distal end to the proximal end of the first shaft 10. The guidewire port 13 is connected to the lumen 10a of the first shaft 10. FIG. 1 shows a so-called rapid exchange type catheter 100. The first shaft 10 may have a first distal shaft portion 11 and a first proximal shaft portion 12 located proximally of the first distal shaft portion 11. The first distal shaft portion 11 and the first proximal shaft portion 12 may be separate members, with the proximal end of the member constituting the first distal shaft portion 11 connected to the distal end of the member constituting the first proximal shaft portion 12. Alternatively, the first distal shaft portion 11 and the first proximal shaft portion 12 may be formed from a single member.

Although not shown, the catheter 100 can also be of a so-called over-the-wire type, in which a lumen 10a is formed from the distal end to the proximal end of the first shaft 10. When the catheter 100 is of an over-the-wire type, it is preferable that the lumen 10a of the first shaft 10 extend in the longitudinal direction x of the catheter 100 to the position where the hub 70 is located.

The outer surface 10c of the first shaft 10 may be coated. As shown in FIG. 1, if the catheter 100 is a rapid exchange type, the outer surface of at least one of the first distal shaft portion 11 and the first proximal shaft portion 12 may be coated, or the outer surfaces of both the first distal shaft portion 11 and the first proximal shaft portion 12 may be coated. If the catheter 100 is an over-the-wire type, only a portion or the entire outer surface 10c of the first shaft 10 may be coated.

The coating applied to the outer surface 10c of the first shaft 10 can be a hydrophilic or hydrophobic coating depending on the purpose. The coating can be applied by immersing the first shaft 10 in a hydrophilic or hydrophobic coating agent, by applying a hydrophilic or hydrophobic coating agent to the outer surface 10c of the first shaft 10, or by covering the outer surface 10c of the first shaft 10 with a hydrophilic or hydrophobic coating agent. Drugs or additives may also be added to the coating agent.

Hydrophilic coating agents include hydrophilic polymers such as polyvinyl alcohol, polyethylene glycol, polyacrylamide, polyvinylpyrrolidone, and methyl vinyl ether maleic anhydride copolymer, as well as hydrophilic coating agents composed of combinations of these.

Hydrophobic coating agents include polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP), perfluoroalkoxyalkane (PFA), silicone oil, hydrophobic urethane resin, carbon coating, diamond coating, diamond-like carbon (DLC) coating, ceramic coating, and substances with low surface free energy terminated with alkyl groups or perfluoroalkyl groups.

(Embodiment 2)

A catheter according to one embodiment of the present invention comprises a first shaft having a longitudinal and radial direction and a lumen extending in the longitudinal direction; a tip member connected to the distal end of the first shaft, having a lumen communicating with the lumen of the first shaft, and including an elongated portion extending in the longitudinal direction of the first shaft and having an X-ray opaque portion; a second shaft disposed in the lumen of the first shaft and the lumen of the tip member and moving in the longitudinal direction of the first shaft relative to the first shaft; and a balloon disposed in the distal portion of the second shaft, having a main body portion that expands and contracts in the radial direction of the first shaft, the length of the main body portion protruding from the first shaft in a radial direction, the length of the main body portion being adjustable depending on the length of the patient's lesion; the balloon has a convex portion that protrudes outward in the radial direction of the first shaft from the main body portion, at least a portion of the elongated portion being disposed distal to the distal end of the first shaft, and the distal end of the elongated portion being movable outward in the radial direction of the first shaft by expansion of the balloon.

The overall configuration of a catheter 100 according to an embodiment of the present invention will be described with reference to Figures 16 to 31. These figures show a catheter 100 comprising a first shaft 10, a tip member 20, a second shaft 50, and a balloon 60. The first shaft 10 has a longitudinal direction x, a radial direction y, and a circumferential direction c.

The components and parts of the catheter 100 other than the first shaft 10 also have longitudinal, radial, and circumferential directions. The longitudinal, radial, and circumferential directions of the components and parts of the catheter 100 other than the first shaft 10 may or may not match the longitudinal direction x, radial direction y, and circumferential direction c of the first shaft 10. For ease of understanding, this specification shows a configuration in which the longitudinal, radial, and circumferential directions of all components and parts match the longitudinal direction x, radial direction y, and circumferential direction c of the first shaft 10, respectively.

In this specification, the proximal side refers to the direction toward the user's hand in the longitudinal direction x of the first shaft 10, and the distal side refers to the opposite side of the proximal side, i.e., the direction toward the treatment target. Furthermore, when each member or part is divided into two equal parts in the longitudinal direction x of the first shaft 10, the part of each member or part located on the distal side is referred to as the distal part of each member or part, and the part of each member or part located on the proximal side is referred to as the proximal part of each member or part. The distal end of each member or part is the end located most distally of each member or part. The proximal end of each member or part is the end located most proximal of each member or part. The end includes the peripheral portion of the end. In other words, the distal end refers to the distal end and the peripheral portion of the distal end, and the proximal end refers to the proximal end and the peripheral portion of the proximal end.

16 is a side view of a catheter according to an embodiment of the present invention. FIG. 17 is an enlarged cross-sectional view (partial side view) of the distal portion of the catheter shown in FIG. 16. FIG. 18 is a cross-sectional view (partial side view) of the catheter shown in FIG. 17, showing a state in which a portion of the main body is expanded outside the first shaft. FIG. 19 is a cross-sectional view (partial side view) of a modified example of the catheter shown in FIG. 18. FIG. 20 is a cross-sectional view (partial side view) of a modified example of the catheter shown in FIG. 17. FIG. 21 is a cross-sectional view (partial side view) of the catheter shown in FIG. 20, showing a state in which a portion of the main body is expanded outside the first shaft. FIG. 22 is a cross-sectional view (partial side view) of a modified example of the catheter shown in FIG. 18. More specifically, FIGS. 17 to 22 show cross sections passing through the central axis of the first shaft and parallel to the longitudinal direction of the first shaft. FIGS. 23 to 27 are side views showing modified examples of the tip member. Figure 28 is a cross-sectional end view taken along line XIII-XIII in Figure 17. Figures 29 and 30 are cross-sectional end views showing modified examples of the tip member shown in Figure 28. Figure 31 is a cross-sectional end view taken along line XVI-XVI in Figure 21.

As shown in Figures 16 to 22, the catheter 100 comprises a first shaft 10, a tip member 20, a second shaft 50, and a balloon 60.

As shown in Figures 17 to 22, the first shaft 10 has a longitudinal direction x and a radial direction y, and has an inner lumen 10a extending in the longitudinal direction x. The first shaft 10 may have an inner surface 10b facing the inner lumen 10a and an outer surface 10c facing the outside of the first shaft 10. Furthermore, the first shaft 10 preferably has a distal end 10d and a proximal end.

As shown in Figures 16 to 27, the tip member 20 is connected to the distal end of the first shaft 10 and has a lumen 20a that communicates with the lumen 10a of the first shaft 10. The tip member 20 may have an inner surface 20b facing the lumen 20a and an outer surface 20c facing the outside of the tip member 20. The lumen 20a of the tip member 20 preferably extends in the longitudinal direction x of the first shaft 10. Furthermore, the tip member 20 preferably has a distal end 20d and a proximal end 20e.

The tip member 20 has an elongated portion 35 extending in the longitudinal direction x of the first shaft 10. The elongated portion 35 has an X-ray opaque portion 25.

As shown in FIG. 27, the radiopaque portion 25 may be formed by forming only a portion of the elongated portion 35 from a material containing a radiopaque substance. As shown in FIG. 17, the radiopaque portion 25 may be formed by forming the entire elongated portion 35 from a material containing a radiopaque substance.

As shown in Figures 17 to 22, the second shaft 50 is disposed in the inner cavity 10a of the first shaft 10 and the inner cavity 20a of the tip member 20, and moves relative to the first shaft 10 in the longitudinal direction x of the first shaft 10.

As shown in Figures 17 to 22, the balloon 60 is disposed at the distal portion of the second shaft 50 and has a main body 61 that expands and contracts in the radial direction y of the first shaft 10, and the length of the main body 61 protruding from the first shaft 10 can be adjusted depending on the length of the patient's lesion. More specifically, it is preferable that the length of the main body 61 protruding from the first shaft 10 can be adjusted by moving the second shaft 50 relative to the first shaft 10 in the longitudinal direction x of the first shaft 10.

As shown in FIG. 31, the balloon 60 has a protrusion 67 that protrudes outward from the main body 61 in the radial direction y of the first shaft 10.

As shown in Figures 17 to 22, at least a portion of the elongated portion 35 is disposed distal to the distal end 10d of the first shaft 10. The entire elongated portion 35 may be disposed distal to the distal end 10d of the first shaft 10. Although not shown, only a portion of the elongated portion 35 may be disposed distal to the distal end 10d of the first shaft 10, with the remaining portion of the elongated portion 35 being disposed proximal to the distal end 10d of the first shaft 10.

The distal end of the elongated portion 35 can move outward in the radial direction y of the first shaft 10 due to the expansion of the balloon 60. Figures 17 and 20 show the balloon 60 in a deflated state. Figures 18, 19, 21, and 22 show the balloon 60 in an expanded state, with the distal end of the elongated portion 35 moving outward in the radial direction y of the first shaft 10. A portion of the elongated portion 35 may be movable outward in the radial direction y of the first shaft 10, or the entire elongated portion 35 may be movable outward in the radial direction y of the first shaft 10.

As shown in Figures 17 to 22, expansion of the balloon 60 moves the distal end of the elongated portion 35 outward in the radial direction y of the first shaft 10, allowing the elongated portion 35 to more easily conform to the shape of the proximal end of the main body portion 61 expanding outside the first shaft 10. Because the elongated portion 35 has an X-ray opaque portion 25, the shape of the proximal end of the main body portion 61 expanding outside the first shaft 10 can be easily visualized under X-ray fluoroscopy. This makes it easy to adjust the length of the main body portion 61 expanding outside the first shaft 10 to the length of the lesion, and to appropriately position the main body portion 61 expanding outside the first shaft 10 at the lesion. This makes it easier to prevent damage to normal tissue caused by treatment being performed on areas other than the lesion.

The catheter 100 can be used, for example, by inserting the distal end of the first shaft 10 to the lesion, and then protruding a portion of the main body 61 of the balloon 60 disposed in the lumen 10a of the first shaft 10 and the lumen 20a of the tip member 20 from the first shaft 10. By expanding the balloon 60 while leaving a portion of the main body 61 protruding from the first shaft 10, it becomes easy to adjust the length of the main body 61 expanding outside the first shaft 10 to the length of the lesion. When a guidewire 1 is used, the guidewire 1 is placed in the body cavity, and then the distal end of the first shaft 10 is inserted to the lesion.

As shown in FIG. 22, the first shaft 10 preferably has a protrusion 14 that protrudes inward in the radial direction y of the first shaft 10. With this configuration, when the balloon 60 is inflated with a portion of the main body 61 protruding from the first shaft 10, the protrusion 14 bites into the balloon 60, making it easier to suppress movement of the balloon 60 in the longitudinal direction x of the first shaft 10.

The first shaft 10 may have only one protrusion 14, but may also have multiple protrusions 14.

A single protrusion 14 may be elongated and extend in the longitudinal direction x of the first shaft 10, but is preferably elongated and extend in the circumferential direction c of the first shaft 10. A single protrusion 14 may be elongated and extend spirally so as to wind around the second shaft 50. A single protrusion 14 may also be columnar, polygonal pyramidal, polygonal truncated pyramidal, conical, truncated conical, or hemispherical, and multiple protrusions 14 having these shapes may be scattered.

The proximal end of the tip member 20 may be connected to the distal end of the first shaft 10. The proximal end 20e of the tip member 20 may be connected to the distal end 10d of the first shaft 10. The proximal end of the tip member 20 may be fixed to the distal end of the first shaft 10. The proximal end 20e of the tip member 20 may be fixed to the distal end 10d of the first shaft 10.

The tip member 20 may have a tapered portion in which the outer diameter decreases toward the distal end when the balloon 60 is deflated, i.e., in its natural state. The tip member 20 may have a straight tube portion in which the outer diameter is constant when the balloon 60 is deflated, i.e., in its natural state.

The tip member 20 may be made of a material including resin or metal.

As shown in Figures 16 to 27, the tip member 20 preferably has a fixing portion 22 in its proximal portion. The fixing portion 22 is preferably a portion whose inner diameter does not expand when the balloon 60 is expanded. Furthermore, the fixing portion 22 preferably has a portion that is fixed to the first shaft 10. It is preferable that at least a portion of the fixing portion 22 is fixed to the first shaft 10 in the longitudinal direction x of the first shaft 10. That is, only a portion of the fixing portion 22 may be fixed to the first shaft 10 in the longitudinal direction x of the first shaft 10, or the entire fixing portion 22 may be fixed to the first shaft 10 in the longitudinal direction x of the first shaft 10. Since the inner diameter of the fixing portion 22 does not expand when the balloon 60 is expanded, the tip member 20 is less likely to come off the first shaft 10.

It is preferable that the proximal end of the fixing portion 22 is fixed to the distal end of the first shaft 10. The proximal end of the fixing portion 22 may also be fixed to the distal end 10d of the first shaft 10. The distal end of the first shaft 10 may be inserted into the inner cavity of the fixing portion 22, and the inner surface of the fixing portion 22 may be fixed to the outer surface 10c of the first shaft 10. The fixing portion 22 may also be inserted into the inner cavity 10a of the first shaft 10, and the inner surface 10b of the first shaft 10 and the outer surface of the fixing portion 22 may be fixed.

The tip member 20 preferably has multiple elongated portions 35. Each elongated portion 35 changes shape in accordance with the deformation of the balloon 60 due to its expansion, making it easier to express the shape of the proximal end of the main body portion 61 expanding outside the first shaft 10.

The tip member 20 may be composed of multiple members, or may be composed of a single member. For example, as shown in Figure 18, the tip member 20 may include a plate-shaped member 38 and a ring-shaped member 39, with the proximal end of the plate-shaped member 38 located within the lumen of the ring-shaped member 39. As shown in Figures 25 and 26, the tip member 20 may include a slit tube 36 having a slit 37 extending from the distal end 20d toward the proximal side. It is preferable to provide multiple slits 37.

The elongated portion 35 is preferably made of a material containing a shape memory material. A shape memory material is a material that has the ability to remember its shape. Examples of shape memory materials that can be used include metals such as stainless steels such as SUS304 and SUS316, platinum, nickel, cobalt, chromium, titanium, tungsten, aluminum, gold, silver, Ni-Ti alloys, and Co-Cr alloys, as well as resins such as norbornene-based polymers, trans-polyisoprene-based polymers, styrene-butadiene-based copolymers, polyurethane-based polymers, polyester-based polymers, polyolefin-based polymers, and acrylic-based polymers.

The distal end of the elongated portion 35 preferably has rounded edges, either by being rounded or by being spherically processed as shown in Figure 27. By processing the distal end of the elongated portion 35 in this manner, it is possible to more easily prevent damage to blood vessels when the distal end of the elongated portion 35 comes into contact with the blood vessels. Furthermore, as shown in Figure 27, the spherically processed portion at the distal end of the elongated portion 35 may be formed from a material containing an X-ray opaque substance, thereby forming the X-ray opaque portion 25.

23 and 25, the length of the distal end of the elongated portion 35 in the circumferential direction c of the first shaft 10 may be longer than the length of the proximal end of the elongated portion 35 in the circumferential direction c of the first shaft 10. By making the length of the distal end of the elongated portion 35 in the circumferential direction c of the first shaft 10 relatively long, the visibility of the distal end of the elongated portion 35 under X-ray fluoroscopy is likely to be improved, making it easier to improve the visibility of the shape of the proximal end of the main body portion 61 expanding outside the first shaft 10. Furthermore, by making the length of the proximal end of the elongated portion 35 in the circumferential direction c of the first shaft 10 relatively short, the rigidity of the proximal end of the elongated portion 35 is reduced. Therefore, the distal end of the elongated portion 35 is more likely to move outward in the radial direction y of the first shaft 10 due to the expansion of the balloon 60.

As shown in FIG. 24, the length of the proximal end of the elongated portion 35 in the circumferential direction c of the first shaft 10 may be longer than the length of the distal end of the elongated portion 35 in the circumferential direction c of the first shaft 10. By making the length of the distal end of the elongated portion 35 in the circumferential direction c of the first shaft 10 relatively short, the rigidity of the distal end of the elongated portion 35 is reduced. This makes it easier for the distal end of the elongated portion 35 to follow the deformation of the balloon 60 due to the expansion of the balloon 60.

As shown in Figure 26, the number of slits 37 present in the distal portion 36a of the slit tube 36 is preferably greater than the number of slits 37 present in the proximal portion 36b of the slit tube 36. With the above configuration, the length of the elongated portion 35 in the circumferential direction c of the first shaft 10 becomes shorter toward the distal side, making it easier for the distal end of the elongated portion 35 to move outward in the radial direction y of the first shaft 10 due to the expansion of the balloon 60, and making it easier for the elongated portion 35 to conform to the shape of the proximal end of the main body portion 61 expanding outside the first shaft 10.

As shown in FIG. 25, the length of the proximal end of the slit 37 in the circumferential direction c of the first shaft 10 is preferably longer than the length of the distal end of the slit 37 in the circumferential direction c of the first shaft 10. By making the length of the proximal end of the slit 37 in the circumferential direction c of the first shaft 10 relatively long, the proximal ends of adjacent elongated portions 35 are less likely to come into contact with each other. This makes it easier for the distal ends of the elongated portions 35 to move outward in the radial direction y of the first shaft 10 due to the expansion of the balloon 60.

As shown in Figures 28, 29, and 30, the multiple long portions 35 may include a first long portion 351 and a second long portion 352. The multiple long portions 35 may further include a third long portion 353, a fourth long portion 354, a fifth long portion 355, and a sixth long portion 356. The multiple long portions 35 may be aligned in the circumferential direction c of the first shaft 10.

As shown in Figures 29 and 30, one elongated portion 35 is preferably configured to be located further outward in the radial direction y of the first shaft 10 than the other elongated portions 35. More specifically, when the balloon 60 is deflated, the second elongated portion 352 is preferably located further outward in the radial direction y of the first shaft 10 than the first elongated portion 351. This configuration makes it possible to increase the length of the distal end of the elongated portion 35 in the circumferential direction c of the first shaft 10 while making it easier to reduce the outer diameter of the tip member 20. This improves the visibility of the shape of the proximal end of the main body portion 61 expanding outside the first shaft 10 under X-ray fluoroscopy, while making it easier to reduce the diameter of the tip member 20. Note that when the balloon 60 is deflated, one elongated portion 35 may not be configured to be located further outward in the radial direction y of the first shaft 10 than the other elongated portions 35.

As shown in FIG. 19 , the tip member 20 may have an outer membrane 23 that is disposed outward in the radial direction y of the first shaft 10 from the elongated portion 35 and is made of a material with lower rigidity than the material that makes up the elongated portion 35. The elongated portion 35 may be partially or entirely embedded in the outer membrane 23. This makes it possible to prevent tissue damage that would occur if the elongated portion 35 came into direct contact with the tissue.

The outer membrane 23 is preferably cylindrical, with the elongated portion 35 disposed within its lumen. The distal end of the elongated portion 35 is preferably located proximal to the distal end of the outer membrane 23. It is more preferable that the entire elongated portion 35 be disposed within the lumen of the cylindrical outer membrane 23.

The outer membrane 23 can be made from any of the materials exemplified below as materials that can be used to make the balloon 60.

The radiopaque portion 25 can be made of a material containing a radiopaque substance, such as lead, barium, iodine, tungsten, gold, platinum, iridium, stainless steel, titanium, or a cobalt-chromium alloy. The entire radiopaque portion 25 may be made of a radiopaque substance alone. The radiopaque portion 25 may also be made of a combination of a radiopaque substance and another material.

The radiopaque portion 25 may contain particles containing the radiopaque material described above. The particles containing the radiopaque material may be composed entirely of the radiopaque material, or only partially of the radiopaque material. The particles containing the radiopaque material are preferably composed of the radiopaque material and a dispersant. Examples of dispersants that may be used to form the particles containing the radiopaque material include resin dispersants such as polyamide resin, polyester resin, polyurethane resin, and polyolefin resin, organic salt dispersants such as magnesium stearate, and inorganic dispersants such as talc. The elongated portion 35 may be formed from a base resin in which particles containing the radiopaque material described above are mixed. Examples of base resins that can be used include polyamide resin, polyester resin, polyurethane resin, polyolefin resin, vinyl chloride resin, silicone resin, natural rubber, and fluororesin.

The second shaft 50 can be configured to have an inner cavity extending in the longitudinal direction x of the first shaft 10. As can be seen from Figures 17 to 22, the inner cavity of the second shaft 50 can be used as a passage for inserting the guide wire 1, etc.

As shown in Figures 17 to 22, the second shaft 50 may have a second inner shaft 51 and a second outer shaft 52. The second outer shaft 52 has an inner lumen and is preferably disposed in the inner lumen 10a of the first shaft 10. The second inner shaft 51 has an inner lumen in which the guide wire 1 is disposed and is preferably disposed in the inner lumen of the second outer shaft 52.

The second outer shaft 52 is preferably connected to an indeflator that injects fluid to be supplied inside the balloon 60.

It is preferable that the first shaft 10 and the second shaft 50 are flexible. This makes it easier to deform the first shaft 10 and the second shaft 50 to fit the shape of the body cavity. In addition, it is preferable that the first shaft 10 and the second shaft 50 have elasticity in order to maintain their shape.

The shape of the first shaft 10 and the second shaft 50 can be, for example, a hollow cylinder, a hollow polygonal prism, etc.

The first shaft 10 and the second shaft 50 can be, for example, a hollow body formed by arranging one or more wires in a predetermined pattern; a hollow body with a resin coating on at least one of the inner and outer surfaces; a resin tube; or a combination of these, such as a combination of these connected in the longitudinal direction. Examples of hollow bodies with wires arranged in a predetermined pattern include tubular bodies with a mesh structure formed by crossing or weaving wires, and coils with wound wires. The wires may be one or more solid wires or one or more twisted wires. Resin tubes can be manufactured by extrusion molding, for example. When the first shaft 10 and the second shaft 50 are resin tubes, the first shaft 10 and the second shaft 50 can be constructed from a single layer or multiple layers. The first shaft 10 and the second shaft 50 may be constructed from a single layer in a portion of the longitudinal direction x or circumferential direction c of the first shaft 10, and the other portion may be constructed from multiple layers.

The first shaft 10 and the second shaft 50 can be made of synthetic resins such as polyolefin resins (e.g., polyethylene and polypropylene), polyamide resins (e.g., nylon), polyester resins (e.g., PET), aromatic polyether ketone resins (e.g., PEEK), polyether polyamide resins, polyurethane resins, polyimide resins, and fluororesins (e.g., PTFE, PFA, and ETFE), or metals such as stainless steel, carbon steel, and nickel-titanium alloys. These may be used alone or in combination of two or more types. The first shaft 10 and the second shaft 50 may be made of the same material, or may be made of different materials.

The outer diameter of the first shaft 10 can be, for example, 1.0 mm or more, 1.1 mm or more, 1.2 mm or more, etc. The outer diameter of the first shaft 10 can also be, for example, 5.0 mm or less, 4.0 mm or less, 3.0 mm or less, etc., but is preferably 2.0 mm or less.

The inner diameter of the first shaft 10 can be, for example, 4.0 mm or less, 3.8 mm or less, 3.5 mm or less, etc. The inner diameter of the first shaft 10 can also be, for example, 0.4 mm or more, 0.5 mm or more, 0.6 mm or more, etc., but is preferably 0.8 mm or more, and more preferably 1.2 mm or more. It is also preferable that the inner diameter of the first shaft 10 is large enough to allow the second shaft 50 to pass through.

The balloon 60 is preferably made of resin. Resins that can be used to make the balloon 60 include polyamide resin, polyester resin, polyurethane resin, polyolefin resin, vinyl chloride resin, silicone resin, and natural rubber. These can be used alone or in combination of two or more. Of these, polyamide resin, polyester resin, and polyurethane resin are preferred. Elastomer resin can be used to make the balloon 60 thinner and more flexible.

The balloon 60 may have a distal sleeve portion 64 fixed to the second inner shaft 51 and a proximal sleeve portion 65 fixed to the second outer shaft 52.

As shown in Figures 18, 19, 21, and 22, when the balloon 60 is inflated, the main body 61 preferably has a portion 62 protruding from the first shaft 10 and a portion 63 located in the lumen 10a of the first shaft 10. When the balloon 60 is inflated, the portion 62 of the main body 61 protruding from the first shaft 10 preferably has a straight tube portion 62b, a distal tapered portion 62a located distal to the straight tube portion 62b, and a proximal tapered portion 62c located proximal to the straight tube portion 62b. The balloon 60 having the above configuration makes it easier for the straight tube portion 62b to come into contact with the lesion.

As shown in Figure 18, when the balloon 60 is inflated, the elongated portion 35 preferably has an abutment portion 24 that abuts the straight tube portion 62b. This makes it easier to visualize the proximal end of the straight tube portion 62b, which is likely to abut the lesion.

The abutment portion 24 is preferably arranged so that it is parallel to the longitudinal direction of the balloon 60, the longitudinal direction x of the first shaft 10, the longitudinal direction of the second shaft 50, etc. Note that "parallel" here includes strict parallelism up to ±10°.

20 and 21, it is preferable that the inner diameter of a portion of the first shaft 10 when the balloon 60 is inflated is larger than the inner diameter of the portion of the first shaft 10 when the balloon 60 is deflated, and that the inner diameter of the fixing portion 22 when the balloon 60 is inflated is smaller than the inner diameter of the portion of the first shaft 10 when the balloon 60 is inflated. This configuration makes it easier to suppress movement of the balloon 60 in the longitudinal direction x of the first shaft 10 when the balloon 60 is inflated with a portion of the main body portion 61 protruding from the first shaft 10. For example, this can be implemented by having the first shaft 10 have an outer layer 15 and an inner layer 16 located inward of the outer layer 15 in the radial direction y of the first shaft 10, and the inner layer 16 being made of a material with a lower hardness than the outer layer 15. Hardness can be measured by measuring the repulsive force during compression, measuring the elastic modulus using a scanning probe microscope (SPM), measuring Rockwell hardness, or measuring Shore hardness, but it is preferably measured by measuring Shore hardness.

The balloon 60 may have only one protrusion 67, but may also have multiple protrusions 67. For example, as shown in FIG. 31, the multiple protrusions 67 may include a first protrusion 671, a second protrusion 672, a third protrusion 673, a fourth protrusion 674, a fifth protrusion 675, and a sixth protrusion 676. The multiple protrusions 67 may be aligned in the circumferential direction c of the first shaft 10.

The single protrusion 67 may be elongated and extend in the circumferential direction of the balloon 60, but is preferably elongated and extend in the longitudinal direction of the balloon 60. The longitudinal direction of the single protrusion 67 may be inclined with respect to the circumferential direction or the longitudinal direction of the balloon 60. The single protrusion 67 may extend in a spiral manner so as to wind around the second shaft 50. The single protrusion 67 may also be cylindrical, polygonal pyramidal, polygonal truncated pyramidal, conical, truncated conical, or hemispherical, and multiple protrusions 67 having these shapes may be scattered.

The shape of one elongated protrusion 67 in a cross section perpendicular to the longitudinal direction of the elongated protrusion 67 may be a polygon such as a triangle or a rectangle, a partial circular shape such as a semicircle or a sector, a wedge shape, a convex shape, a spindle shape, or an irregular shape. Polygons include polygons with clearly defined corners and straight sides, as well as rounded polygons with rounded corners and polygons with at least some of the sides curved.

The number of slits 37 may be the same as the number of protrusions 67 on the balloon 60, or may be different. The number of slits 37 in the circumferential direction of the balloon 60 may be the same as the number of protrusions 67 in the circumferential direction of the balloon 60. In a cross section perpendicular to the longitudinal direction of the balloon 60, the number of slits 37 may be the same as the number of protrusions 67 on the balloon 60.

As can be seen from Figure 31, it is preferable that the convex portions 67 of the balloon 60 and the elongated portions 35 do not come into contact when the balloon 60 is in an expanded state. It is also preferable that the convex portions 67 and the elongated portions 35 of the balloon 60 are arranged alternately in the circumferential direction of the balloon 60 when the balloon 60 is in an expanded state. With this configuration, the convex portions 67 of the balloon 60 are more likely to come into contact with the lesion, which makes it easier to improve treatment efficiency.

As can be seen from Figure 31, it is preferable that the protrusions 67 and main body 61 of the balloon 60 are integrally molded. However, it is also acceptable for the protrusions 67 and main body 61 of the balloon 60 to be made from separate members, with the member making up the protrusions 67 of the balloon 60 being fixed to the member making up the main body 61 of the balloon 60.

The length from the distal end to the proximal end of the catheter 100 can be, for example, 200 mm or more, 250 mm or more, 300 mm or more, etc. The length from the distal end to the proximal end of the catheter 100 can also be, for example, 2500 mm or less, 2450 mm or less, 2400 mm or less, etc.

As shown in FIG. 16, a hub 70 may be connected to the proximal portion of the first shaft 10. The first shaft 10 and the hub 70 may be fixed together. For example, the first shaft 10 and the hub 70 can be fixed together by adhesive bonding, welding, screws, etc.

Figure 16 discloses an embodiment in which a guidewire port 13 is formed midway from the distal end to the proximal end of the first shaft 10. The guidewire port 13 is connected to the lumen 10a of the first shaft 10. Figure 16 shows a so-called rapid exchange type catheter 100. The first shaft 10 may have a first distal shaft portion 11 and a first proximal shaft portion 12 located proximal to the first distal shaft portion 11. The first distal shaft portion 11 and the first proximal shaft portion 12 may be separate members, with the proximal end of the member constituting the first distal shaft portion 11 connected to the distal end of the member constituting the first proximal shaft portion 12. Alternatively, the first distal shaft portion 11 and the first proximal shaft portion 12 may be formed from a single member.

Although not shown, the catheter 100 can also be of a so-called over-the-wire type, in which a lumen 10a is formed from the distal end to the proximal end of the first shaft 10. When the catheter 100 is of an over-the-wire type, it is preferable that the lumen 10a of the first shaft 10 extend in the longitudinal direction x of the catheter 100 to the position where the hub 70 is located.

The outer surface 10c of the first shaft 10 may be coated. As shown in FIG. 16, if the catheter 100 is a rapid exchange type, the outer surface of at least one of the first distal shaft portion 11 and the first proximal shaft portion 12 may be coated, or the outer surfaces of both the first distal shaft portion 11 and the first proximal shaft portion 12 may be coated. If the catheter 100 is an over-the-wire type, only a portion or the entire outer surface 10c of the first shaft 10 may be coated.

The coating applied to the outer surface 10c of the first shaft 10 can be a hydrophilic or hydrophobic coating depending on the purpose. The coating can be applied by immersing the first shaft 10 in a hydrophilic or hydrophobic coating agent, by applying a hydrophilic or hydrophobic coating agent to the outer surface 10c of the first shaft 10, or by covering the outer surface 10c of the first shaft 10 with a hydrophilic or hydrophobic coating agent. Drugs or additives may also be added to the coating agent.

Hydrophilic coating agents include hydrophilic polymers such as polyvinyl alcohol, polyethylene glycol, polyacrylamide, polyvinylpyrrolidone, and methyl vinyl ether maleic anhydride copolymer, as well as hydrophilic coating agents composed of combinations of these.

Hydrophobic coating agents include polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP), perfluoroalkoxyalkane (PFA), silicone oil, hydrophobic urethane resin, carbon coating, diamond coating, diamond-like carbon (DLC) coating, ceramic coating, and substances with low surface free energy terminated with alkyl groups or perfluoroalkyl groups.

This application claims the benefit of priority from Japanese Patent Application No. 2024-050048, filed March 26, 2024, and the benefit of priority from Japanese Patent Application No. 2024-050049, filed March 26, 2024. The entire contents of the specifications of Japanese Patent Application No. 2024-050048 and Japanese Patent Application No. 2024-050049 are incorporated herein by reference.

1: Guidewire 10: First shaft 100: Catheter 10a: Lumen 10b: Inner surface 10c: Outer surface 10d: Distal end 11: First distal shaft portion 12: First proximal shaft portion 13: Guidewire port 14: Convex portion 15: Outer layer 16: Inner layer 20: Tip member 20a: Lumen 20b: Inner surface 20c: Outer surface 20d: Distal end 20e: Proximal end 22: Fixation portion 23: Outer membrane 24: Abutment portion 25: X-ray opaque portion 35: Long portion 351: First long portion 352: Second long portion 353: Third long portion 354: Fourth long portion 355: Fifth long portion 356: Sixth long portion 36: Slit tube 36a: Distal portion 36b : Proximal portion 37: Slit 38: Plate-like member 39: Ring-like member 50: Second shaft 51: Second inner shaft 52: Second outer shaft 60: Balloon 61: Main body 62: Portion 62a protruding from first shaft: Distal tapered portion 62b: Straight tube portion 62c: Proximal tapered portion 63: Portion 64 located in the lumen of the first shaft: Distal sleeve portion 65: Proximal sleeve portion 67: Convex portion 671: First convex portion 672: Second convex portion 673: Third convex portion 674: Fourth convex portion 675: Fifth convex portion 676: Sixth convex portion 70: Hub c: Circumferential direction of first shaft x: Longitudinal direction of first shaft y: Radial direction of first shaft

Claims (31)

a first shaft having a longitudinal direction and a radial direction and having an inner lumen extending in the longitudinal direction;
a tip member connected to the distal end of the first shaft, having an inner lumen communicating with the inner lumen of the first shaft, and including an elongated portion extending in the longitudinal direction and having a radiopaque portion;
a second shaft disposed in the lumen of the first shaft and the lumen of the tip member and adapted to move in the longitudinal direction relative to the first shaft;
a balloon disposed at a distal portion of the second shaft, the balloon having a main body portion that expands and contracts in the radial direction, and a protruding length of the main body portion from the first shaft that can be adjusted depending on the length of a lesion in a patient;
At least a portion of the elongated portion is disposed distal to the distal end of the first shaft,
A catheter in which the distal end of the elongated portion is movable radially outward by expansion of the balloon. The catheter described in claim 1, wherein the tip member has a fixed portion at its proximal portion that is fixed to the first shaft and whose inner diameter does not expand when the balloon is expanded. A catheter as described in claim 1 or 2, wherein the tip member is disposed radially outward of the elongated portion and has an outer membrane made of a material less rigid than the material constituting the elongated portion. When the balloon is in an expanded state, the portion of the main body protruding from the first shaft has a straight tube portion, a distal tapered portion located distal to the straight tube portion, and a proximal tapered portion located proximal to the straight tube portion,
3. The catheter according to claim 1, wherein the elongated portion has an abutting portion that abuts against the straight tube portion when the balloon is in an expanded state. A catheter according to claim 1 or 2, wherein the first shaft has a protrusion that protrudes radially inward. The catheter described in claim 1 or 2, wherein the elongated portion is made of a material containing a shape-memory material. A catheter according to claim 1 or 2, wherein the length of the distal end of the elongated portion in the circumferential direction of the first shaft is longer than the length of the proximal end of the elongated portion in the circumferential direction of the first shaft. A catheter according to claim 1 or 2, wherein the length of the proximal end of the elongated portion in the circumferential direction of the first shaft is longer than the length of the distal end of the elongated portion in the circumferential direction of the first shaft. A catheter as described in claim 1 or 2, wherein the tip member comprises a slit tube having a slit extending from the distal end toward the proximal side. The catheter of claim 9, wherein the number of slits present in the distal portion of the slit tube is greater than the number of slits present in the proximal portion of the slit tube. The catheter of claim 9, wherein the length of the proximal end of the slit in the circumferential direction of the first shaft is longer than the length of the distal end of the slit in the circumferential direction of the first shaft. the distal end member includes a plurality of the elongated portions;
the plurality of elongated portions include a first elongated portion and a second elongated portion;
The catheter according to claim 1 or 2, wherein the second elongated portion is located radially outward of the first elongated portion when the balloon is in a deflated state. an inner diameter of a portion of the first shaft when the balloon is in an expanded state is larger than an inner diameter of the portion of the first shaft when the balloon is in a deflated state;
The catheter according to claim 2, wherein an inner diameter of the fixing portion when the balloon is in an inflated state is smaller than an inner diameter of the portion of the first shaft when the balloon is in an inflated state. the first shaft has an outer layer and an inner layer located radially inward of the outer layer,
The catheter according to claim 13, wherein the inner layer is made of a material having a lower hardness than the outer layer. a first shaft having a longitudinal direction and a radial direction and having an inner lumen extending in the longitudinal direction;
a tip member connected to the distal end of the first shaft, having an inner lumen communicating with the inner lumen of the first shaft, and including an elongated portion extending in the longitudinal direction and having a radiopaque portion;
a second shaft disposed in the lumen of the first shaft and the lumen of the tip member and adapted to move in the longitudinal direction relative to the first shaft;
a balloon disposed at a distal portion of the second shaft, the balloon having a main body portion that expands and contracts in the radial direction, and a protruding length of the main body portion from the first shaft that can be adjusted depending on the length of a lesion in a patient;
the balloon has a protrusion protruding outward in the radial direction from the main body portion,
At least a portion of the elongated portion is disposed distal to the distal end of the first shaft,
A catheter in which the distal end of the elongated portion is movable radially outward by expansion of the balloon. The catheter described in claim 15, wherein the tip member has a fixed portion at its proximal portion, the inner diameter of which does not expand when the balloon is expanded, and which is fixed to the first shaft. The catheter described in claim 15, wherein the tip member has an outer membrane arranged radially outward of the elongated portion and made of a material less rigid than the material constituting the elongated portion. When the balloon is in an expanded state, the portion of the main body protruding from the first shaft has a straight tube portion, a distal tapered portion located distal to the straight tube portion, and a proximal tapered portion located proximal to the straight tube portion,
The catheter according to claim 15, wherein the elongated portion has an abutment portion that abuts against the straight tube portion when the balloon is in an expanded state. A catheter according to any one of claims 15 to 18, wherein the tip member comprises a slit tube having a slit extending from the distal end toward the proximal side. The catheter described in claim 19, wherein the number of slits is the same as the number of protrusions on the balloon. The catheter described in any one of claims 15 to 18, wherein the convex portion and the elongated portion of the balloon do not abut when the balloon is in an expanded state. The catheter described in any one of claims 15 to 18, wherein the convex portion and the main body portion of the balloon are integrally molded. A catheter according to any one of claims 15 to 18, wherein the first shaft has a protrusion that protrudes radially inward. A catheter according to any one of claims 15 to 18, wherein the elongated portion is made of a material containing a shape-memory material. A catheter according to any one of claims 15 to 18, wherein the length of the distal end of the elongated portion in the circumferential direction of the first shaft is longer than the length of the proximal end of the elongated portion in the circumferential direction of the first shaft. A catheter according to any one of claims 15 to 18, wherein the length of the proximal end of the elongated portion in the circumferential direction of the first shaft is longer than the length of the distal end of the elongated portion in the circumferential direction of the first shaft. The catheter of claim 19, wherein the number of slits present in the distal portion of the slit tube is greater than the number of slits present in the proximal portion of the slit tube. The catheter of claim 19, wherein the length of the proximal end of the slit in the circumferential direction of the first shaft is longer than the length of the distal end of the slit in the circumferential direction of the first shaft. the distal end member includes a plurality of the elongated portions;
the plurality of elongated portions include a first elongated portion and a second elongated portion;
The catheter according to any one of claims 15 to 18, wherein the second elongated portion is located radially outward of the first elongated portion when the balloon is deflated. an inner diameter of a portion of the first shaft when the balloon is in an expanded state is larger than an inner diameter of the portion of the first shaft when the balloon is in a deflated state;
17. The catheter of claim 16, wherein an inner diameter of the fixation portion when the balloon is in an expanded state is smaller than an inner diameter of the portion of the first shaft when the balloon is in an expanded state. the first shaft has an outer layer and an inner layer located radially inward of the outer layer,
31. The catheter of claim 30, wherein the inner layer is made of a material having a lower hardness than the outer layer.