JP7410706B2 - balloon catheter - Google Patents

Description

TECHNICAL FIELD The present invention relates to balloon catheters.

It has been known that various diseases occur due to stenosis of blood vessels in the body. For example, if stenosis occurs in a coronary artery that supplies blood to the heart, there is a risk of serious diseases such as angina pectoris and myocardial infarction. One method of treating such a narrowed portion of a blood vessel is to dilate the narrowed portion using a balloon catheter, and various balloon catheters have been known so far.

For example, Patent Document 1 describes an inner tube that is inserted into the lumen of an outer shaft and the inside of a balloon to form a guide wire lumen, and that is fixed to the outer peripheral surface of the inner tube or is formed integrally with the inner tube and has a radius of A balloon catheter is disclosed that includes an anti-slip element that projects outwardly and presses against the inner surface of the balloon when the balloon is expanded.

Furthermore, Patent Document 2 describes a balloon arranged to extend in the axial direction while contacting the outer periphery of a guide wire insertion tube extending from the tip of an outer shaft, and a position on the outer periphery where the balloon is in contact with the outer shaft. A balloon that is fixed to the outer periphery of the guidewire insertion tube or formed integrally with the guidewire insertion tube at a position on the opposite side in the circumferential direction, and includes a slip prevention element that protrudes radially outward of the guidewire insertion tube. A catheter is disclosed.

Japanese Patent Application Publication No. 2016-096869 JP2016-220861A

In balloon catheters such as those disclosed in Patent Documents 1 and 2, when the balloon is inflated, one side of the balloon that is in direct or indirect contact with a tube provided with an anti-slip element is difficult to inflate, while The other side of the balloon that was not in indirect contact had a structure that was easily inflated. In such a structure, the balloon may curve when inflated, and the tube may also curve, which may actually make it difficult to dilate the stenotic region.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a balloon catheter that can easily dilate a stenotic region.

The balloon catheter according to the present invention, which can solve the above problems, has the following configuration.
[1] A balloon catheter comprising a shaft extending in a distance direction and a balloon provided on a distal side of the shaft,
The proximal end of the balloon is fixed to the shaft by a proximal fixation part,
The distal end of the balloon is fixed to the shaft by a distal fixation part,
The balloon is distal to the distal end of the proximal fixation part, and the balloon is directly attached to the shaft at a part halfway proximal to the proximal end of the distal fixation part. or has a fixed part that is indirectly fixed and a non-fixed part where the balloon is not fixed to the shaft,
The non-fixed part has a reinforcing part,
The balloon catheter is characterized in that the fixing part and the reinforcing part are spaced apart from each other by 1/4 or more of the circumference in the circumferential direction of the balloon.

As mentioned above, the balloon has a fixed part that is fixed to the shaft and a non-fixed part that is not fixed to the shaft, and the non-fixed part is separated from the fixed part by more than 1/4 of the circumference in the circumferential direction of the balloon. By providing the reinforcing portion at the position, the curvature of the shaft is suppressed, thereby making it easier to expand the narrowed portion.

Furthermore, the balloon catheter according to the present invention preferably also includes the following configurations [2] to [16].
[2] The balloon catheter according to [1], wherein the shaft is located outside the balloon.
[3] The balloon catheter according to [2], wherein the shaft includes a protruding portion in the middle portion that protrudes toward the side opposite to the balloon.
[4] The balloon catheter according to [1], wherein the shaft is located inside the balloon.
[5] The balloon catheter according to [4], wherein the shaft includes a protrusion that protrudes toward the fixed part.
[6] The balloon catheter according to [4] or [5], wherein the central axis of the shaft is located closer to the fixed part than the central axis of the balloon.
[7] The balloon catheter according to any one of [1] to [6], wherein the reinforcing portion is formed by a thick portion of the balloon.
[8] The balloon catheter according to any one of [1] to [7], wherein the reinforcing portion includes a reinforcing member.
[9] The balloon catheter according to any one of [1] to [8], wherein in a radial cross section of the balloon, the maximum thickness of the reinforcing portion is greater than or equal to the maximum thickness of the shaft.
[10] The balloon catheter according to any one of [1] to [8], wherein in a radial cross section of the balloon, the maximum thickness of the reinforcing portion is smaller than the maximum outer diameter of the shaft.
[11] The balloon catheter according to any one of [1] to [10], wherein the balloon includes a straight tube portion extending in the axial direction of the shaft, and the fixing portion is located in the straight tube portion.
[12] The balloon has a proximal tapered portion that expands in diameter toward the distal side, a straight tube portion, and a distal tapered portion that decreases in diameter toward the distal side, and the reinforcing portion The balloon catheter according to any one of [1] to [11], wherein the balloon catheter is located at least at the proximal tapered portion, the straight tube portion, and the distal tapered portion.
[13] The balloon catheter according to any one of [1] to [12], wherein the reinforcing portion is elongated.
[14] The balloon catheter according to any one of [1] to [13], wherein the reinforcing portion has a hole extending in a far-to-near direction.
[15] The reinforcing portion has an opening distal to the proximal end of the reinforcing portion and communicating with the hole on the proximal side of the distal end of the reinforcing portion. Balloon catheter.
[16] The balloon catheter according to [14] or [15], wherein the elongated body is slidably disposed in the hole.

According to the present invention, with the above configuration, it is possible to provide a balloon catheter that can easily dilate a stenotic region.

FIG. 1 is a side view of a balloon catheter according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing an axial cross section of region R in FIG. FIG. 3 is a cross-sectional view showing the AA cross section of the balloon catheter of FIG. FIG. 4 is a side view of a conventional balloon catheter. FIG. 5 is a sectional view showing another example of the AA cross section of the balloon catheter in FIG. FIG. 6 is a sectional view showing another example of the AA cross section of the balloon catheter in FIG. 1. FIG. 7 is a sectional view showing another example of the AA cross section of the balloon catheter shown in FIG. FIG. 8 is a sectional view showing another example of the AA cross section of the balloon catheter in FIG. 1. FIG. 9 is a sectional view showing another example of the AA cross section of the balloon catheter in FIG. FIG. 10 is a sectional view showing another example of the axial cross section of region R in FIG. FIG. 11 is a side view of a balloon catheter according to another embodiment of the invention. FIG. 12 is a sectional view showing the BB cross section of the balloon catheter of FIG. 11. FIG. 13 is a perspective view of the elongated body.

In the following, the present invention will be explained in more detail based on the following embodiments, but the present invention is not limited by the following embodiments, and may be modified as appropriate within the scope that fits the spirit of the above and below. Of course, it is also possible to implement in addition, and all of them are included in the technical scope of the present invention. In addition, in each drawing, member numbers etc. may be omitted for convenience, but in such a case, the specification and other drawings shall be referred to. Further, the dimensions of various members in the drawings are given priority to help understanding the features of the present invention, and therefore may differ from actual dimensions.

The balloon catheter of the present invention includes a shaft extending in the distal and proximal directions and a balloon provided on the distal side of the shaft, and the proximal end of the balloon has a proximal fixing portion. The distal end of the balloon is fixed to the shaft by a distal fixation part, and the balloon is distal to the distal end of the proximal fixation part, and the distal end of the balloon is fixed to the shaft by a distal fixation part. A fixed part in which the balloon is directly or indirectly fixed to the shaft, and a non-fixed part in which the balloon is not fixed to the shaft, in the middle part on the proximal side of the proximal end of the proximal fixed part, The non-fixed part has a reinforcing part, and the fixed part and the reinforcing part are separated from each other by 1/4 or more of the circumference in the circumferential direction of the balloon.

As mentioned above, in a balloon catheter having a fixed part in which the balloon is directly or indirectly fixed to the shaft, the non-fixed part of the balloon is located at a position at least 1/4 of the circumference of the balloon in the circumferential direction from the fixed part. By providing the reinforcing portion in the balloon, the curvature of the balloon is suppressed, thereby making it easier to dilate the narrowed portion.

A balloon catheter according to an embodiment of the present invention will be described below with reference to FIGS. 1 to 13. FIG. 1 is a side view of a balloon catheter according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing an axial cross section of region R in FIG. FIG. 3 is a cross-sectional view showing the AA cross section of the balloon catheter of FIG. FIG. 4 is a side view of a conventional balloon catheter. 5 to 9 are cross-sectional views showing other examples of the AA cross section of the balloon catheter in FIG. 1. FIG. 10 is a sectional view showing another example of the axial cross section of region R in FIG. FIG. 11 is a side view of a balloon catheter according to another embodiment of the invention. FIG. 12 is a sectional view showing the BB cross section of the balloon catheter of FIG. 11. FIG. 13 is a perspective view of the elongated body.

As shown in FIGS. 1 and 2, the balloon catheter 1 includes a shaft 10 extending in the far-to-near direction X, and a balloon 20 provided on the distal side of the shaft 10. Furthermore, the proximal end 20A of the balloon 20 is fixed to the shaft 10 by the proximal fixing part 20a, and the distal end 20B of the balloon 20 is fixed to the shaft 10 by the distal fixing part 20b.

The proximal fixing part 20a and the distal fixing part 20b are parts where the balloon 20 and the shaft 10 are firmly connected by welding or the like. 1 and 2, the shaft 10 has an inner tube 11 and an outer tube 12, and the distal fixing portion 20b of the balloon 20 is fixed to the outer surface of the inner tube 11, and the balloon 20 The proximal fixing portion 20a is fixed to the outer surface of the inner tube 11 and the outer surface of the outer tube 12. The proximal fixing portion 20a and the distal fixing portion 20b may each exist over a part of the circumferential direction of the shaft 10, or may exist over the entire circumferential direction of the shaft 10. Note that the inner tube 11 can be used as an insertion path for a guide wire or the like. Further, the space between the inner tube 11 and the outer tube 12 can be a fluid flow path, and the balloon 20 can be inflated by injecting fluid into the pressurized lumen 20I of the balloon 20 through the flow path. can. Examples of the fluid include liquids, such as physiological saline and contrast agents.

As shown in FIGS. 1 to 3, the balloon 20 is distal to the distal end 20X of the proximal fixation part 20a and proximal to the proximal end 20Y of the distal fixation part 20b. The balloon 20 has a fixing part 20F in the middle part 20c, where the balloon 20 is directly fixed to the shaft 10. Specifically, the balloon 20 is fixed by directly contacting the outer surface of the shaft 10 (inner tube 11) along the axial direction of the shaft 10 (inner tube 11) in the fixing portion 20F located in the middle portion 20c. has been done. The fixed portion 20F is difficult to expand due to the rigidity of the shaft 10 (inner tube 11) even if the pressurizing inner cavity 20I is pressurized. The fixing part 20F is a part where the balloon 20 indirectly contacts the shaft 10 (inner tube 11) via an intervening object such as a protrusion 13, as shown in FIGS. 11 and 12 described later. Good too. Further, in the fixing portion 20F, the balloon 20 may be fixed to the shaft 10 (inner tube 11) by bonding or the like.

As shown in FIGS. 1 to 3, the balloon 20 has a non-fixed part 20N in the middle part 20c where the balloon 20 is not fixed to the shaft 10, and the non-fixed part 20N has a reinforcing part 22. Furthermore, the fixing part 20F and the reinforcing part 22 are spaced apart from each other by 1/4 or more of the circumference in the circumferential direction of the balloon 20. For example, in the conventional balloon catheter 100 shown in FIG. 4, there is a fixed part 20F and a non-fixed part 20N on the opposite side to the fixed part 20F (hereinafter sometimes referred to as the opposite non-fixed part 20N). There was a difference in stiffness due to the presence or absence of the material. Furthermore, the conventional balloon catheter 100 is provided with an anti-slip element (protrusion 13) that protrudes toward the opposite side of the balloon 20, thereby increasing the above-mentioned difference in rigidity and causing the balloon 20 to curve when inflated. It was easy. On the other hand, in the balloon catheter 1 according to an embodiment of the present invention, as shown in FIG. Since the difference in rigidity between the fixed part 20F of the balloon 20 and the non-fixed part 20N on the opposite side can be reduced, the curvature during inflation of the balloon and the curvature of the shaft 10 can also be reduced, making it easier to expand the lesion. can do. Further, in this case, when the shaft 10 has the protrusion 13, the protrusion 13 can crack a highly stenotic lesion or a calcified lesion to facilitate expansion. Moreover, this also makes it easier for the protrusion 13 to exhibit an anti-slip function. In FIG. 3, the dashed-dotted line is a line passing through the central axis 20C of the balloon 20, and the portion below the dashed-dotted line is a portion that is more than 1/4 of the circumference in the circumferential direction of the balloon 20 from the fixed portion 20F. This also corresponds to the opposite non-fixed portion 20N. The reinforcing part 22 is preferably separated from the fixing part 20F by 5/16 or more of the circumference in the circumferential direction of the balloon 20, and more preferably by 6/16 or more of the circumference.

Although not shown, the fixing portion 20F may be provided at two or more locations. In that case, it is sufficient that the adjacent fixing part 20F and reinforcing part 22 are separated from each other by 1/4 or more of the circumferential length in the circumferential direction of the balloon 20.

The reinforcing portions 22 may be provided at two or more locations in the circumferential direction of the balloon 20, as shown in FIGS. 5 and 6. On the other hand, although the upper limit is not particularly limited, the reinforcing portions 22 may be provided at 10 or less locations in the circumferential direction of the balloon 20, or may be provided at 5 or less locations in the circumferential direction of the balloon 20. Further, when three or more reinforcing parts 22 are provided in the circumferential direction, it is preferable that each reinforcing part 22 is provided at regular intervals in the circumferential direction of the balloon 20, as shown in FIG.

As shown in FIGS. 1 and 2, the reinforcing portion 22 is preferably elongated. This makes it easier to prevent the balloon 20 from curving. When the reinforcing portion 22 is elongated, it is preferable that the reinforcing portion 22 extends in the axial direction of the shaft 10 . When the reinforcing portion 22 is elongated, it is not limited to a linear shape as shown in FIGS. 1 and 2, but may be a wavy line shape, a zigzag shape, or the like. These are not limited to one type, but two or more types may be provided in combination. Further, the reinforcing portion 22 is not limited to an elongated shape, but may have a net shape or the like.

Examples of the shape of the reinforcing portion 22 in the circumferential cross section of the balloon 20 include polygonal shapes such as triangular, rectangular, and trapezoidal shapes, hemispherical shapes, and spherical shapes. Although details will be described later, the reinforcing portion 22 may have a hole 22H extending in the perspective direction X, as shown in FIGS. 9 and 10. Further, the cross-sectional shape of the hole 22H in the circumferential cross-section of the balloon 20 is not particularly limited, but examples thereof include polygons such as triangles, rectangles, and trapezoids, hemispherical shapes, and spherical shapes.

The reinforcing part 22 may include a reinforcing member as shown in FIGS. 3, 5, and 6, or may be formed by a part of the balloon 20 as shown in FIGS. 7, 8, and 9. may have been done.

Examples of the reinforcing member include metal wires, resin wires, and the like. Examples of the material constituting the metal wire include stainless steel, titanium, nickel-titanium alloy, cobalt-chromium alloy, and tungsten alloy. The metal wire may be a single wire or a twisted wire. Examples of materials constituting the resin wire include polyarylate fibers, aramid fibers, ultra-high molecular weight polyethylene fibers, PBO fibers, and carbon fibers. These fibrous materials may be monofilament or multifilament. In addition, the resin forming the balloon 20, which will be described later, may be used as the material forming the resin wire. The reinforcing member may be adhered to the balloon 20 with an adhesive or the like, or may be fixed by welding or the like.

As shown in FIG. 7, the reinforcing part 22 is formed by a part of the balloon 20, and as shown in FIG. A mode in which the reinforcing portion 22 is formed by a hill-shaped thick wall portion 20T of the balloon 20, and a mode in which the reinforcing portion 22 is formed by a rail-shaped thick wall portion 20R of the balloon 20 as shown in FIG. Can be mentioned. Regarding the shape of the thick portion, reference can be made to the description of the shape of the reinforcing portion 22 above. Further, although not shown, the reinforcing portion 22 may be formed by a thick portion of the balloon 20 and a reinforcing member.

Examples of the resin constituting the balloon 20 include at least one selected from the group consisting of polyamide resin, polyester resin, polyurethane resin, polyolefin resin, vinyl chloride resin, silicone resin, and natural rubber. . Among these, at least one selected from the group consisting of polyamide resins, polyester resins, and polyurethane resins is preferred. Furthermore, elastomer resins may be used as these resins.

Balloon 20 can be manufactured by molding resin. For example, the balloon 20 can be manufactured by placing a resin tube extruded by extrusion molding in a mold and performing biaxial stretch blow molding. The balloon 20 can also be manufactured by a known molding method such as dip molding, injection molding, or compression molding.

When the treatment area is a blood vessel, the balloon 20 preferably has an axial length of 5 mm to 300 mm and an outer diameter of 1 mm to 12 mm; when the treatment area is a gastrointestinal tract such as the duodenal papilla, It is preferable that the length in the direction is 10 mm to 100 mm and the outer diameter is 3 mm to 30 mm.

As shown in FIG. 1, the balloon 20 includes a straight tube portion 21c extending in the axial direction of the shaft 10, and the fixing portion 20F is preferably located in the straight tube portion 21c. By providing the shaft 10 with the straight pipe portion 21c, it is possible to easily expand the lesion. Further, by locating the fixing portion 20F on the straight tube portion 21c, it is possible to easily apply the expansion pressure of the straight tube portion 21c to the lesioned area. The balloon 20 also has a proximal tapered portion 21a that expands in diameter toward the distal side, a straight tube portion 21c, and a distal tapered portion 21b that decreases in diameter toward the distal side. It is also preferable that 20F be located at least in the proximal tapered portion 21a, the straight pipe portion 21c, and the distal tapered portion 21b.

The balloon 20 has a proximal tapered part 21a that expands in diameter toward the distal side, a straight tube part 21c, and a distal tapered part 21b that decreases in diameter toward the distal side. are preferably located at least in the proximal tapered portion 21a, the straight pipe portion 21c, and the distal tapered portion 21b. In this way, when the balloon 20 has the proximal tapered part 21a, the straight pipe part 21c, and the distal tapered part 21b, by providing the reinforcing part 22 in each part, it is easy to prevent the balloon 20 from curving. can do. Further, the reinforcing portion 22 may be provided in at least one portion selected from the group consisting of the proximal tapered portion 21a, the straight pipe portion 21c, and the distal tapered portion 21b. The reinforcing portion 22 is also provided at locations other than the proximal tapered portion 21a, the straight pipe portion 21c, and the distal tapered portion 21b, such as the proximal fixed portion 20a and the distal fixed portion 20b. It's okay. For example, the reinforcing part 22 may be provided in the proximal fixing part 20a, the proximal tapered part 21a, the straight tube part 21c, the distal tapered part 21b, and the distal fixing part 20b. Further, the reinforcing portions 22 of each portion may be integrated and provided continuously, or may be provided separately. Further, the balloon 20 may have other shapes, such as a spherical portion, an elongated spherical portion, or the like.

The balloon 20 may include a linear thin section along the axial direction of the shaft 10. Thereby, the balloon 20 before inflation can be easily folded.

As shown in FIGS. 1 to 3, it is preferable that the shaft 10 includes a protrusion 13 that protrudes toward the opposite side from the balloon 20 at an intermediate portion 20c. The protruding portion 13 can create cracks in highly stenotic lesions and calcified lesions to facilitate expansion. Further, the protruding portion 13 may have an anti-slip function or the like. Note that even if the shaft 10 does not have the protruding portion 13, the reinforcing portion 22 can be used to create cracks or provide an anti-slip function, as will be described later.

The shaft 10 (inner tube 11) is preferably located outside the balloon 20. Thereby, the protrusion 13 and the like can be provided on the portion of the shaft 10 (inner tube 11) on the opposite side from the balloon 20.

On the other hand, the shaft 10 (inner tube 11) may be located inside the balloon 20, as shown in FIGS. 11 and 12. Furthermore, the shaft 10 may include a protrusion 13 that protrudes toward the fixed portion 20F. Also in this embodiment, the fixing part 20F, which is formed into a convex shape by the protruding part 13, can crack the calcified lesion and make it easier to expand. Furthermore, positional displacement of the balloon 20 during expansion can be made less likely to occur. Furthermore, such an aspect can prevent the protrusion 13 from separating from the shaft 10 and falling off. Note that the balloon catheter 1 in FIG. 11 has the same configuration as the balloon catheter 1 in FIG. 1 except that a part of the inner tube 11 is located inside the balloon 20.

As shown in FIG. 12, the central axis 10C of the shaft 10 is preferably located closer to the fixed part 20F than the central axis 20C of the balloon 20. As a result, even if the protruding portion 13 is small, it is possible to crack a highly stenotic lesion or a calcified lesion and make it easier to expand. Moreover, this makes it easier for the protrusion 13 to exhibit an anti-slip function.

The shape of the protrusion 13 in the circumferential cross section of the balloon 20 is not particularly limited, and examples include polygonal shapes such as triangular, rectangular, and trapezoidal shapes, hemispherical shapes, and spherical shapes. In the case of a triangular shape, the apex angle (θ) is preferably 30° or more and 100° or less, more preferably 40° or more and 60° or less.

The protruding portion 13 may include a protruding member or may be formed by a part of the shaft 10. Examples of the material constituting the protruding member include metal, resin, and the like. Examples of the metal include stainless steel, titanium, nickel-titanium alloy, cobalt-chromium alloy, tungsten alloy, and the like. Further, regarding the resin, the description of the resin constituting the balloon 20 can be referred to. The protruding member may be adhered to the shaft 10 with an adhesive or the like, or may be fixed by welding or the like. Examples of embodiments in which the protrusion 13 is formed by a part of the shaft 10 include embodiments in which the protrusion 13 is formed by a protrusion of the shaft 10, and embodiments in which the protrusion 13 is formed by a thick portion of the shaft 10. etc.

The combination of the protruding part 13 and the reinforcing part 22 includes a combination in which the protruding part 13 is formed by a part of the shaft 10 and the reinforcing part 22 is formed by a part of the balloon 20; A combination in which the reinforcing part 22 is formed by a part of the balloon 20; a combination in which the protruding part 13 is formed by a part of the shaft 10 and the reinforcing part 22 is provided with a reinforcing member. or a combination in which the protruding portion 13 is provided with a protruding member and the reinforcing portion 22 is provided with a reinforcing member. The more the curvature of the balloon 20 is reduced, the more the protrusion 13 can make it easier to crack and expand a highly stenotic lesion or a calcified lesion. Moreover, this makes it easier for the protrusion 13 to exhibit an anti-slip function. On the other hand, in addition to preventing the balloon 20 from curving, it is also possible to leave some curvature of the balloon 20 when it is inflated and utilize the curvature. For example, by providing a certain degree of difference in rigidity between the protruding part 13 and the shaft 10 and the reinforcing part 22, the reinforcing part 22 of the balloon 20 is located on the outside of the curve and tends to become convex toward the outside. It is possible to create cracks in highly stenotic lesions and calcified lesions to make them easier to expand. Moreover, this makes it easier for the protrusion 13 to exhibit an anti-slip function.

The number of protrusions 13 is not limited to one, and two or more protrusions 13 may be provided on the shaft 10. In this case, it is preferable that the plurality of protrusions 13 are arranged linearly along the axial direction of the shaft 10. The bending elastic modulus of the material constituting the protrusion 13 that can be measured based on JIS K 7171 (2016) is preferably 50 MPa or more. This makes it easier to crack stenotic lesions and calcified lesions. Therefore, the bending elastic modulus is more preferably 100 MPa or more, and even more preferably 150 MPa or more. On the other hand, if the bending elastic modulus is 10,000 MPa or less, the difference in rigidity between the protruding portion 13 and the like and the reinforcing portion 22 can be reduced, making it easier to prevent bending. Therefore, the bending elastic modulus is more preferably 5,000 MPa or less, and even more preferably 2,000 MPa or less. Further, the difference between the bending elastic modulus of the protruding portion 13 and the shaft 10 and the bending elastic modulus of the reinforcing portion 22 is preferably 10,000 MPa or less. This makes it easier to prevent bending due to differences in rigidity. Therefore, the difference in flexural modulus is more preferably 1,500 MPa or less, and even more preferably 100 MPa or less. Further, when the curvature of the balloon 20 is left to some extent during inflation and is utilized, the difference in bending modulus may be 50 MPa or more, or 150 MPa or more.

As shown in FIGS. 3 and 12, in the radial cross section of the balloon 20, the maximum thickness 22T of the reinforcing portion 22 is preferably equal to or greater than the maximum thickness 10T of the shaft 10. This makes it easier to suppress the curvature of the shaft 10 due to the difference in rigidity between the non-fixed portion 20N and the fixed portion 20F. Therefore, the maximum thickness 22T is more preferably 1.1 times or more, and even more preferably 1.5 times or more, the maximum thickness of the shaft 10. Note that the maximum thickness 22T of the reinforcing part 22 is the maximum thickness of the sum of the thickness of the reinforcing member and the thickness of the balloon 20 when the reinforcing part 22 includes a reinforcing member. Further, the maximum thickness 10T of the shaft 10 is the maximum thickness of the sum of the thickness of the shaft 10 and the thickness of the protrusion 13 when the shaft 10 is provided with the protrusion 13.

In the radial cross section of the balloon 20, the maximum thickness 22T of the reinforcing portion 22 is preferably smaller than the maximum outer diameter 10D of the shaft 10. This improves the ease of handling the balloon catheter 1. Furthermore, this allows the shaft 10 to be easily bent to a certain extent so that the reinforcing part 22 is on the outside, thereby preventing the reinforcing part 22 from getting caught on the lesion, or causing a crack in the calcified lesion by the reinforcing part 22. It can be made easier. In this way, in the balloon catheter 1, the reinforcing part 22 not only suppresses the curvature when the balloon 20 is inflated, but also leaves some curvature when the balloon 20 is inflated, and utilizes the curvature to make the reinforcing part 22 may be used to create cracks in highly stenotic lesions or calcified lesions, or the reinforcing portion 22 may have an anti-slip function or the like. Note that the maximum outer diameter 10D of the shaft 10 corresponds to the maximum length of the sum of the outer diameter of the shaft 10 and the thickness of the protrusion 13 when the shaft 10 includes the protrusion 13.

The reinforcing portion 22 may have a hole 22H extending in the perspective direction X, as shown in FIGS. 9 and 10. Furthermore, the reinforcing part 22 may have an opening 22O distal to the proximal end 22A of the reinforcing part 22 and proximal to the distal end 22B of the reinforcing part 22, which communicates with the hole 22H. . With these configurations, the elongated body 30 is inserted into the hole 22H with the linear portion 31 of the elongated body 30 on the proximal side and the blade portion 32 on the distal side as shown in FIG. The blade portion 32 can be exposed from the inside. This makes it easier for the blade portion 32 to come into contact with the lesion, making it easier for the reinforcing portion 22 to crack a highly stenotic lesion or a calcified lesion. Moreover, this also makes it easier for the reinforcing portion 22 to exhibit an anti-slip function. Alternatively, the drug may be injected into the body from the opening 22O via the hole 22H. The drug is not particularly limited as long as it is a pharmacologically active substance, and includes, for example, non-gene therapeutic drugs, biomolecules, small molecules, cells, and other pharmaceutically acceptable drugs. More specifically, anti-restenotic agents such as anti-proliferative agents and immunosuppressants may be mentioned. Only one type of drug may be used, or two or more types may be used.

It is preferable that the elongated body 30 is slidably arranged in the hole 22H. Thereby, the stiffness of the reinforcing portion 22 can be adjusted, and the curvature of the balloon 20 can be easily controlled.

It is preferable that the elongated body 30 includes a linear portion 31 and a blade portion 32. Regarding the material constituting the elongated body 30, the description of the material of the reinforcing portion 22 can be referred to.

Examples of the shape of the blade portion 32 in the cross section in the thickness direction include polygonal shapes such as triangular, rectangular, and trapezoidal shapes, hemispherical shapes, and spherical shapes. Among these, polygonal shapes are preferred, and triangular shapes are more preferred. Further, the blade portion 32 may have a notch in the thickness direction.

Examples of the shape of the linear portion 31 in the cross section in the thickness direction include polygonal shapes such as triangular, rectangular, and trapezoidal shapes, hemispherical shapes, and spherical shapes. Among these, polygonal shapes are preferred, and rectangular shapes are more preferred.

The inner tube 11 of the shaft 10 is made of at least one material selected from the group consisting of, for example, polyamide resin, polyester resin, polyurethane resin, polyolefin resin, fluorine resin, vinyl chloride resin, silicone resin, and natural rubber. May contain seeds. Furthermore, elastomer resins may be used as these resins.

The outer tube 12 of the shaft 10 is made of at least one material selected from the group consisting of polyamide resin, polyester resin, polyurethane resin, polyolefin resin, fluorine resin, vinyl chloride resin, silicone resin, and natural rubber. May contain. Furthermore, elastomer resins may be used as these resins. Note that the number of outer tubes 12 is not limited to one, and two or more may be connected. When two or more are connected, it is preferable to connect them in the axial direction. Note that the outer tube 12 may include a lumen extending in the far-to-near direction X and communicating with the hole 22H of the reinforcing portion 22 as shown in FIG.

Further, the inner tube 11 and the outer tube 12 may have a braided body made of wires, a coiled body made of wires wound helically, or the like. This makes it easier to improve the strength of the inner tube 11 and outer tube 12. Examples of the wire include metal wire, fiber, and the like. Preferable materials for forming the metal wire include stainless steel, titanium, nickel-titanium alloy, cobalt-chromium alloy, tungsten alloy, and the like. The metal wire may be a single wire or a twisted wire. Examples of the fiber include polyarylate fiber, aramid fiber, ultra-high molecular weight polyethylene fiber, PBO fiber, and carbon fiber. The fibers may be monofilament or multifilament.

The inner tube 11 and the outer tube 12 may include an X-ray opaque portion containing an X-ray opaque substance. As the X-ray opaque substance, for example, at least one member selected from the group consisting of lead, barium, iodine, tungsten, gold, platinum, iridium, platinum-iridium alloy, stainless steel, titanium, cobalt-chromium alloy, palladium, and tantalum is used. Can be mentioned.

As shown in FIGS. 1, 11, etc., the balloon catheter 1 preferably has a handle portion 40 on the proximal side. It is preferable that the handle part 40 has an lumen that communicates with a space between the inner tube 11 and the outer tube 12, which is a flow path for injecting fluid into the pressurized lumen 20I of the balloon 20. . Further, the balloon catheter 1 is of a rapid exchange type (RX type) into which a guide wire can be inserted from the proximal end 11A of the inner tube 11 provided on the distal side of the handle portion 40. However, the balloon catheter 1 is an over-the-wire type (OTW type) in which the proximal end 11A of the inner tube 11 is located within the handle portion 40 and a guide wire can be inserted from the proximal end to the distal end. There may be.

1 Balloon catheter 10 Shaft 10T Maximum thickness of shaft 10C Central axis of shaft 10D Maximum outer diameter of shaft 11 Inner tube 12 Outer tube 13 Projection 20 Balloon 20A Proximal end of balloon 20B Distal end of balloon 20C Central axis of balloon 20F Fixed part 20I Pressurized lumen 20N Non-fixed part 20P Projection-like thick part of the balloon 20T Hill-like thick part of the balloon 20R Rail-like thick part of the balloon 20a Proximal fixation part 20b Distal fixation Part 20X Distal end of proximal fixation part 20Y Proximal end of distal fixation part 20c Midway part 21a Proximal tapered part 21c Straight pipe part 21b Distal tapered part 22 Reinforcement part 22A Proximal end of reinforcement part 22B Distal end of reinforcing portion 22H Hole extending in the far-to-near direction 22O Opening communicating with the hole 22T Maximum thickness of reinforcing portion 30 Long body 31 Linear portion 32 Blade portion 40 Handle portion 100 Conventional balloon catheter

Claims (17)

A balloon catheter comprising a shaft extending in a distance direction and a balloon provided on a distal side of the shaft,
a proximal end of the balloon is secured to the shaft by a proximal securing section;
The distal end of the balloon is fixed to the shaft by a distal fixation part,
The balloon is distal to the distal end of the proximal fixation part, and the balloon is directly attached to the shaft at a part of the proximal side of the proximal end of the distal fixation part. or has a fixed part that is indirectly fixed and a non-fixed part where the balloon is not fixed to the shaft,
The non-fixed part has a reinforcing part,
The balloon catheter is characterized in that the fixing part and the reinforcing part are separated from each other by 1/4 or more of the circumference in the circumferential direction of the balloon. The balloon catheter of claim 1, wherein the shaft is located outside of the balloon. The balloon catheter according to claim 2, wherein the shaft includes a protrusion in the middle portion that protrudes toward a side opposite to the balloon. The balloon catheter according to claim 1, wherein the shaft is located inside the balloon. The balloon catheter according to claim 4, wherein the shaft includes a protrusion that protrudes toward the fixed part. 6. The balloon catheter according to claim 4, wherein the central axis of the shaft is located closer to the fixing part than the central axis of the balloon. The balloon catheter according to any one of claims 1 to 6, wherein the reinforcing portion is formed by a thick portion of the balloon. The balloon catheter according to any one of claims 1 to 7, wherein the reinforcing portion includes a reinforcing member. The balloon catheter according to any one of claims 1 to 8, wherein the shaft is a hollow tubular member. The balloon catheter according to claim 9 , wherein the maximum thickness of the reinforcing portion is greater than or equal to the maximum thickness of the shaft in a radial cross section of the balloon. The balloon catheter according to any one of claims 1 to 10 , wherein a maximum thickness of the reinforcing portion in a radial cross section of the balloon is smaller than a maximum outer diameter of the shaft. The balloon catheter according to any one of claims 1 to 11 , wherein the balloon includes a straight tube portion extending in the axial direction of the shaft, and the fixing portion is located in the straight tube portion. The balloon has a proximal tapered portion that expands in diameter toward the distal side, a straight tube portion, and a distal tapered portion that decreases in diameter toward the distal side, and the reinforcing portion includes at least The balloon catheter according to any one of claims 1 to 12 , wherein the balloon catheter is located at the proximal tapered portion, the straight tube portion, and the distal tapered portion. The balloon catheter according to any one of claims 1 to 13 , wherein the reinforcing portion has an elongated shape. The balloon catheter according to any one of claims 1 to 14 , wherein the reinforcing portion has a hole extending in a far-to-near direction. 16. The balloon catheter according to claim 15 , wherein the reinforcing part has an opening distal to the proximal end of the reinforcing part and communicating with the hole on the proximal side of the distal end of the reinforcing part. The balloon catheter according to claim 15 or 16 , wherein an elongated body is slidably arranged in the hole.

Images