Balloon for catheter

Abstract

The balloon catheter (1A) comprises: an expansion portion (3B) having a cylindrical shape extending in the extension direction; an anterior connecting portion (3A) extending from the anterior end portion (30D) of the expansion portion (3B) to the side opposite to the expansion portion (3B); and a basal connecting portion (3C) extending from the basal end portion (30P) of the expansion portion (3B) to the side opposite to the expansion portion (3B). The balloon (3) has an inner thick membrane portion (4A) and a thin membrane portion (40) of different thicknesses. The thickness of the inner thick membrane portion (4A) is greater than that of the thin membrane portion (40). The outer diameter, which is the radial distance from the central axis (C1) extending through the center of the expansion portion (3B) in the extension direction to the outer surface (302), is the same at the thin membrane portion (40) as at the inner thick membrane portion (4A). The inner diameter, which is the radial distance from the central axis (C1) to the inner surface (301), is smaller at the inner thick film portion (4A) than at the thin film portion (40).

Description

Technical Field

[0001] This invention relates to balloons for catheters. Background Technology

[0002] In balloon catheters, high pressure resistance of the balloon is required, and various methods have been proposed to achieve this. For example, in the balloon catheter described in Patent Document 1, a reinforcing portion is provided on the outer surface of the base balloon, thereby increasing the strength of the base balloon and suppressing excessive expansion of the base balloon during pressurization.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent No. 6259560 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] When a balloon has an external thickness, there is a problem of reduced balloon permeability within the blood vessel. Furthermore, when a balloon is used to leave a stent within the blood vessel, the external thickness makes it prone to snagging on the stent. In this case, there are potential problems such as reduced balloon permeability when passing through the stent, or difficulty in detaching the balloon from the stent after inflating it.

[0008] The purpose of this invention is to provide a catheter balloon that can maintain intravascular permeability while achieving high pressure resistance.

[0009] Solution for solving the problem

[0010] The catheter balloon of the present invention comprises: an expansion portion having a cylindrical shape extending in an extension direction; a front end connection portion extending from a first front end portion of the expansion portion on one side of the extension direction toward a side opposite to the expansion portion, wherein the diameter of the end portion connected to the expansion portion is larger than the diameter of a second front end portion on the side opposite to the end portion connected to the expansion portion; and a base end connection portion extending from a first base end portion of the expansion portion on the other side of the extension direction toward a side opposite to the expansion portion, wherein the diameter of the end portion connected to the expansion portion is larger than the diameter of a second base end portion on the side opposite to the end portion connected to the expansion portion. The catheter balloon is characterized in that it has an inner thick membrane portion and a thin membrane portion, each with a different thickness, the thickness of the inner thick membrane portion being greater than that of the thin membrane portion, the inner surface of the inner thick membrane portion protruding radially inward towards a central axis extending in the extension direction from the center of the expansion portion, compared to the inner surface of the thin membrane portion, and the outer surface of the inner thick membrane portion not protruding radially outward relative to the outer surface of the thin membrane portion.

[0011] Catheter balloons can achieve high pressure resistance by using the inner thick membrane portion to suppress rapid expansion. The outer surface of the inner thick membrane portion does not protrude radially outward compared to the outer surface of the thin membrane portion. Therefore, catheter balloons can maintain good permeability within the blood vessel.

[0012] In this invention, the outer diameter, which is the radial distance from the central axis to the outer surface, may be the same in the thin film portion and the inner thick film portion, while the inner diameter, which is the radial distance from the central axis to the inner surface, may be smaller in the inner thick film portion than in the thin film portion. The outer diameter of the catheter balloon is the same in the inner thick film portion and the thin film portion, and it does not protrude laterally in the thicker inner film portion. Therefore, the catheter balloon can further maintain good intravascular permeability.

[0013] In this invention, the inner thick membrane portion may also extend along the extension direction. The catheter balloon can utilize the inner thick membrane portion to suppress rapid expansion and contraction along the extension direction during contraction and expansion. Therefore, the catheter balloon can suppress rapid radial expansion corresponding to elongation in the extension direction, thus achieving high pressure resistance.

[0014] In this invention, the expansion portion may also include an inner thick film portion that extends along the extension direction over the entire range from the first anterior end portion to the first basal end portion. The catheter balloon can suppress rapid contraction and expansion along the extension direction during both contraction and expansion throughout the entire area of ​​the expansion portion.

[0015] In this invention, the expansion portion may also include an outer thick membrane portion and an inner thick membrane portion, both with a thickness greater than that of the thin membrane portion. The inner diameter is the same at the thin membrane portion and at the outer thick membrane portion, while the outer diameter is larger at the outer thick membrane portion than at the thin membrane portion. The inner and outer thick membrane portions are aligned in the extending direction, with the inner thick membrane portion closer to the first anterior end portion than the outer thick membrane portion, and the outer thick membrane portion closer to the first basal end portion than the inner thick membrane portion. The catheter balloon does not have an outer thick membrane portion at the front end of the expansion portion. Therefore, compared to the case where an outer thick membrane portion is present throughout the entire area of ​​the expansion portion in the extending direction, the catheter balloon is less likely to be held in a fully stretched state along the extending direction. Therefore, for example, during the insertion of the balloon into a stent-containing vessel, even if the outer thick membrane portion is hooked onto the stent, it is possible to prevent the catheter balloon from being held in a fully stretched state along the extending direction. Therefore, it is possible to prevent unwanted forces from being applied to the stent from the catheter balloon.

[0016] In this invention, the inner thick film portion may also be provided in the expansion portion, the front end connection portion, and the base end connection portion, and the inner thick film portion extends along the extension direction over the entire range from the second front end portion to the second base end portion. The catheter balloon can suppress rapid expansion and contraction along the extension direction during contraction and expansion throughout the entire area of ​​the expansion portion, the front end connection portion, and the base end connection portion.

[0017] In this invention, the thickness of the inner thick membrane portion of the front-end connector may decrease from the portion connected to the first front end of the expansion portion towards the second front end, and the thickness of the inner thick membrane portion of the base-end connector may decrease from the portion connected to the first base end of the expansion portion towards the second base end. The catheter balloon allows for flexibility in the second front end of the front-end connector and the second base end of the base-end connector, thus preventing the catheter balloon from being held in a fully stretched state along the extension direction when these portions come into contact with stents, hard lesions, etc.

[0018] In this invention, at least one slit may be provided in the inner thick membrane portion. The catheter balloon can easily bend the inner thick membrane portion using the slit, thus allowing for good deformation even within meandering blood vessels. Therefore, the catheter balloon can effectively follow the blood vessel.

[0019] In this invention, the catheter balloon may also have a plurality of slits arranged in the extending direction, the spacing between each of the plurality of slits in the extending direction being narrower closer to the second anterior end. For the catheter balloon, the narrower the spacing between the plurality of slits at the anterior end, the easier it is to bend. In this case, when the catheter balloon enters a meandering blood vessel, it can easily follow the vessel. Therefore, the user can properly guide the catheter balloon to the target site. On the other hand, for the catheter balloon, the wider the spacing between the plurality of slits at the basal end, the greater its rigidity. In this case, the stress exerted by the catheter balloon on the lesion of the blood vessel can be increased, thus improving treatment efficiency.

[0020] In this invention, the catheter balloon may also have a plurality of slits arranged in the extending direction, each slit being deeper closer to the second anterior end. For the catheter balloon, the deeper the depth of the slits at the anterior end, the easier it is to bend. In this case, when the catheter balloon enters a meandering blood vessel, it can easily follow the vessel. Therefore, the user can properly guide the catheter balloon to the target site. On the other hand, for the catheter balloon, the shallower the depth of the slits at the basal end, the greater the rigidity. In this case, the stress exerted by the catheter balloon on the lesion of the blood vessel can be increased, thus improving treatment efficiency.

[0021] In this invention, the inner thick film portion may also be annular, extending circumferentially around the central axis. The catheter balloon can maintain high pressure resistance even when the film portion is thin. Furthermore, the catheter balloon improves flexibility when bent in directions intersecting the extension direction.

[0022] In this invention, the inner thick film portion may also be spirally arranged circumferentially extending around the central axis and disposed over the entire range between the first anterior end portion and the first base end portion. The catheter balloon can have the inner thick film portion seamlessly disposed over the entire range of the expansion portion's extension direction, thus maintaining high pressure resistance over the entire range of the expansion portion's extension direction. Furthermore, the flexibility of the catheter balloon can be improved.

[0023] In this invention, the inner thick membrane portion may also be disposed over the entire range between the second anterior end portion and the second basal end portion. The catheter balloon can have the inner thick membrane portion seamlessly disposed over the entire region between the second anterior end portion and the second basal end portion, thus maintaining high pressure resistance over a greater range in the extension direction.

[0024] In this invention, at least one slit may be provided in the inner thick membrane portion. The catheter balloon can bend the inner thick membrane portion using the slit, thus allowing for good deformation even within meandering blood vessels. Therefore, the catheter balloon can follow the blood vessel well.

[0025] In this invention, the catheter balloon may also have a plurality of slits arranged in the direction extending from the inner thick membrane portion, and when viewed from the extending direction, each of the plurality of slits is positioned to overlap with at least one of the other slits. The catheter balloon can be configured with a portion of higher flexibility and a portion of lower flexibility in the circumferential direction. In this case, when the catheter balloon is inserted into a meandering blood vessel, it can easily follow the blood vessel. Therefore, the user can properly guide the catheter balloon to the target site. Attached Figure Description

[0026] Figure 1 This is a diagram showing balloon catheter 1A and a cross-sectional view obtained by cutting balloon catheter 1A with a plane orthogonal to the direction of extension.

[0027] Figure 2 This is a diagram showing the balloon catheter 1B and a cross-sectional view obtained by cutting the balloon catheter 1B with a plane orthogonal to the extension direction.

[0028] Figure 3 This is a diagram showing balloon catheter 1C and a cross-sectional view obtained by cutting balloon catheter 1C with a plane parallel to the direction of extension.

[0029] Figure 4 This is a diagram showing the balloon catheter 1D and a cross-sectional view obtained by cutting the balloon catheter 1D with a plane parallel to the direction of extension.

[0030] Figure 5 This is a diagram showing the balloon catheter 1E and a cross-sectional view obtained by cutting the balloon catheter 1E with a plane orthogonal to the extension direction.

[0031] Figure 6 This is a diagram showing the balloon catheter 1F and a cross-sectional view obtained by cutting the balloon catheter 1F with a plane parallel to the direction of extension.

[0032] Figure 7 This is a diagram showing the balloon catheter 1G and a cross-sectional view obtained by cutting the balloon catheter 1G with a plane orthogonal to the extension direction. Detailed Implementation

[0033] Embodiments (1A to 1G) of the balloon catheter 1 of the present invention will be described with reference to the accompanying drawings. The accompanying drawings are used to illustrate the technical features employed in the present invention. The structures of the described devices are not intended to be limited thereto, but are merely illustrative examples. The balloon catheter 1 can dilate stenotic lesions formed in blood vessels or expand stents within blood vessels using a balloon 3.

[0034] <First Embodiment (Balloon Catheter 1A)>

[0035] Reference Figure 1 The balloon catheter 1A is described below. The balloon catheter 1A has a catheter shaft 2 and a balloon 3.

[0036] <Catheter axis 2>

[0037] The balloon 3 is connected to one end of the tubular catheter shaft 2. The balloon catheter 1A is used with a catheter tip (not shown) connected to the other end of the catheter shaft 2. The catheter tip can supply compressed fluid to the balloon 3 via the catheter shaft 2.

[0038] Hereinafter, one of the two ends of the catheter shaft 2 will be referred to as the "front end side". The other end of the catheter shaft 2 will be referred to as the "base end side". The direction of extension along the catheter shaft 2 will be referred to as the "extension direction". The shaft that passes through the center of the catheter shaft 2 and extends along the extension direction will be referred to as the central axis C1. In the cross-section (hereinafter simply referred to as the "section") in the case of cutting in a plane orthogonal to the central axis C1, the side closer to the central axis C1 in the radial direction centered on the central axis C1 will be referred to as the "inner side", and the side away from the central axis C1 in the radial direction centered on the central axis C1 will be referred to as the "outer side".

[0039] The conduit shaft 2 has an outer tube 21 and an inner tube 22. Both the outer tube 21 and the inner tube 22 are flexible. The inner diameter of the outer tube 21 is larger than the outer diameter of the inner tube 22. The inner tube 22, except for a predetermined portion at its front end, is disposed within the lumen of the outer tube 21. A predetermined portion at the front end of the inner tube 22 protrudes from the end of the outer tube 21 at its front end (hereinafter referred to as "front end 211") toward the front end. The end of the inner tube 22 at its front end (hereinafter referred to as "front end 221") is positioned further toward the front end than the front end 211 of the outer tube 21. Hereinafter, the predetermined portion at the front end of the inner tube 22 will be referred to as "protruding portion 225". The materials of the outer tube 21 and the inner tube 22 are not particularly limited; polyamide resin is used as an example.

[0040] Compressed fluid supplied from the catheter tip flows through the space outside the inner lumen of the inner tube 22, which is located within the inner lumen of the outer tube 21. A guidewire (not shown) is inserted into the inner lumen of the inner tube 22.

[0041] <Balloon 3>

[0042] The internal pressure of balloon 3 changes accordingly with the presence or absence of a supply of compressed fluid from a catheter tip (not shown), thus enabling it to deform between a contracted and inflated state. Figure 1 The balloon 3 in its inflated state is shown. The anterior end of the balloon 3 (hereinafter referred to as "anterior end 3D") is heat-fused to the vicinity of the front end 221 of the protrusion 225 of the inner tube 22. Additionally, the basal end of the balloon 3 (hereinafter referred to as "basal end 3P") is heat-fused to the vicinity of the front end 211 of the outer tube 21. The balloon 3 covers the protrusion 225 of the inner tube 22 from the outside. The material of the balloon 3 is not particularly limited; polyamide resin is used as an example.

[0043] In the balloon 3, an anterior connecting portion 3A, an expansion portion 3B, and a base connecting portion 3C are defined. The anterior connecting portion 3A is the region in the balloon 3 in its inflated state that extends from the anterior end portion 3D toward the base end portion 3P while expanding in diameter. The base connecting portion 3C is the region in the balloon 3 in its inflated state that extends from the base end portion 3P toward the anterior end portion 3D while expanding in diameter. The expansion portion 3B is the region in the balloon 3 in its inflated state sandwiched between the anterior connecting portion 3A and the base connecting portion 3C, and has a substantially uniform diameter throughout its extension direction. In the inflated state, the expansion portion 3B becomes a cylindrical shape extending along the extension direction. The balloon 3 has an inner surface 301 and an outer surface 302. The radial distance between the central axis C1 and the inner surface 301 is called the inner diameter Ri(n) (n is an integer). The radial distance between the central axis C1 and the outer surface 302 is called the outer diameter Ro(n).

[0044] The end portion on the front end side of the expansion portion 3B is referred to as the "front end portion 30D", and the end portion on the base end side is referred to as the "base end portion 30P". The front end connecting portion 3A extends from the end portion connected to the front end portion 30D of the expansion portion 3B toward the front end portion 3D towards the front end portion 3D. The diameter of the cross-section of the front end connecting portion 3A is largest at the end portion connected to the front end portion 30D of the expansion portion 3B and smallest at the front end portion 3D. The base end connecting portion 3C extends from the end portion connected to the base end portion 30P of the expansion portion 3B toward the base end portion 3P towards the base end portion 3P. The diameter of the cross-section of the base end connecting portion 3C is largest at the end portion connected to the base end portion 30P of the expansion portion 3B and smallest at the base end portion 3P.

[0045] The expansion portion 3B has inner thick film portions 41, 42, and 43 (hereinafter referred to as "inner thick film portion 4A" without distinction) and a thin film portion 40. The thicknesses of the inner thick film portion 4A and the thin film portion 40 are different. The thickness of the inner thick film portion 4A is greater than that of the thin film portion 40. The outer diameter Ro(1) of the expansion portion 3B is the same at the inner thick film portion 4A and at the thin film portion 40. Therefore, the outer surface 302 of the expansion portion 3B is a smooth state without any bumps or depressions. On the other hand, the inner diameter Ri(n) of the expansion portion 3B is different at the inner thick film portion 4A and at the thin film portion 40. The inner diameter Ri(1) at the inner thick film portion 4A is smaller than the inner diameter Ri(2) at the thin film portion 40. Therefore, the inner surface 301 of the expansion portion 3B protrudes inward at the inner thick film portion 4A. Hereinafter, this part is referred to as "protrusion 300". The protrusion 300 is convexly curved toward the central axis C1.

[0046] The inner thick film portion 4A extends along the extension direction over the entire range from the front end portion 30D of the expansion portion 3B to the base end portion 30P. The inner thick film portions 41, 42, and 43 are arranged at equal intervals in the circumferential direction centered on the central axis C1. The inner diameter Ri(1) of the inner thick film portion 4A is uniform over the entire range from the front end portion 30D to the base end portion 30P. That is, the amount of protrusion of the protrusion 300 formed on the inner surface 301 of the inner thick film portion 4A toward the central axis C1 is uniform over the entire range from the front end portion 30D to the base end portion 30P.

[0047] The thin film portion 40 is disposed between the inner thick film portions 41 and 42, between the inner thick film portions 42 and 43, and between the inner thick film portions 43 and 41 in the circumferential direction.

[0048] <Function and Effects of the First Embodiment>

[0049] In balloon catheter 1A, the thickness of the inflatable portion 3B of balloon 3 is greater at the inner thick membrane portion 4A than at the thin membrane portion 40. Therefore, balloon 3 can suppress rapid inflation using the inner thick membrane portion 4A, thus achieving high pressure resistance. The outer diameter Ro(1) of balloon 3 is the same at the inner thick membrane portion 4A and at the thin membrane portion 40, and even the thicker inner thick membrane portion 4A does not protrude laterally. Therefore, balloon catheter 1A can maintain good permeability of balloon 3 within the blood vessel.

[0050] The thick membrane portion 4A located inside the expansion portion 3B can suppress the rapid expansion and contraction of the balloon 3 along the extension direction during contraction and expansion. Therefore, the balloon catheter 1A can suppress the rapid radial expansion of the front end connection portion 3A, the expansion portion 3B, and the base end connection portion 3C in accordance with the elongation in the extension direction of the balloon 3, thus achieving high pressure resistance.

[0051] The inner thick membrane portion 4A extends along the extension direction throughout the entire range between the anterior end portion 30D and the basal end portion 30P of the expansion portion 3B. Therefore, the balloon catheter 1A can suppress the rapid expansion and contraction of the balloon 3 along the extension direction during contraction and expansion throughout the entire region of the expansion portion 3B. Furthermore, the balloon catheter 1A, particularly at the expansion portion 3B, suppresses the increase in the diameter of the balloon 3 during expansion, thereby reducing the pressure exerted on the blood vessel in its normal state. Moreover, the balloon catheter 1A can improve the durability of the expansion portion 3B of the balloon 3.

[0052] <Special Considerations for the First Implementation>

[0053] The expansion portion 3B of the balloon 3 is not limited to a cylindrical shape. The diameter of the expansion portion 3B can also vary throughout the entire range of the extension direction. The cross-sectional shape of the expansion portion 3B is not limited to a circle, but can also be elliptical or polygonal. In this case, the outer diameter Ro(1) of the expansion portion 3B can also be different at the inner thick membrane portion 4A and at the thin membrane portion 40.

[0054] The shape of the inner thick film portion 4A is not limited to the above embodiment and can be modified in various ways. The number of inner thick film portions 4A extending along the extension direction is not limited to 3, but can be 1, 2, 4 or more. The inner thick film portion 4A may not be provided in the entire range between the front end portion 30D and the base end portion 30P in the expansion portion 3B. For example, the inner thick film portion 4A may also be broken in a part of the extension direction.

[0055] The front end of the protrusion 300 formed on the inner surface 301 of the inner thick film portion 4A near the central axis C1 can be sharp or smooth. The thickness of the inner thick film portion 4A can also be smaller closer to the front end 30D. The thickness of the inner thick film portion 4A can also be smaller closer to the base end 30P.

[0056] <Second Embodiment (Balloon Catheter 1B)>

[0057] Reference Figure 2 The balloon catheter 1B will be described. The balloon catheter 1B differs from the balloon catheter 1A in that it not only has an inner thick membrane portion 4B in the expansion portion 3B of the balloon 3, but also has an inner thick membrane portion 4B in the front end connection portion 3A and the base end connection portion 3C.

[0058] The front connecting portion 3A, the expansion portion 3B, and the base connecting portion 3C have inner thick film portions 44, 45, and 46 (hereinafter referred to as "inner thick film portion 4B" without distinction) and a thin film portion 40. The inner thick film portion 4B extends along the extension direction throughout the entire range from the front end portion 3D of the front connecting portion 3A to the base end portion 3P of the base connecting portion 3C. The thickness of the inner thick film portion 4B in the expansion portion 3B is uniform throughout the entire range from the front end portion 30D to the base end portion 30P. Therefore, the inner diameter Ri(1) of the inner thick film portion 4B is uniform throughout the entire range from the front end portion 30D to the base end portion 30P. That is, the amount of protrusion of the protrusion 300 formed on the inner surface 301 of the inner thick film portion 4B toward the inward side is uniform throughout the entire range from the front end portion 30D to the base end portion 30P.

[0059] On the other hand, the thickness of the inner thick film portion 4B in the front end connecting portion 3A gradually decreases from the portion of the front end 30D of the front end connecting portion 3A that is connected to the front end portion 3D of the expansion portion 3B toward the front end portion 3D. That is, the amount of protrusion of the protrusion 300 formed on the inner surface 301 of the inner thick film portion 4B toward the inward side gradually decreases from the front end portion 30D toward the front end portion 3D.

[0060] Furthermore, the thickness of the inner thick film portion 4B in the base end connecting portion 3C gradually decreases from the portion of the base end portion 3C connected to the base end portion 30P of the expansion portion 3B towards the base end portion 3P. That is, the amount of protrusion of the protrusion 300 formed on the inner surface 301 of the inner thick film portion 4B toward the central axis C1 gradually decreases from the base end portion 30P towards the base end portion 3P.

[0061] <Function and Effects of the Second Embodiment>

[0062] In the balloon catheter 1B, an inner thick membrane portion 4B is provided within the balloon 3, extending from the anterior end portion 3D of the anterior connector 3A to the basal end portion 3P of the basal connector 3C. In this case, the balloon catheter 1B can suppress rapid expansion and contraction along the extension direction during contraction and expansion, not only throughout the entire area of ​​the expansion portion 3B but also throughout the entire areas of the anterior connector 3A and the basal connector 3C.

[0063] The thickness of the inner thick membrane portion 4B of the anterior connecting portion 3A gradually decreases from the portion connecting to the anterior end portion 30D of the expansion portion 3B towards the anterior end portion 3D. Similarly, the thickness of the inner thick membrane portion 4B of the basal connecting portion 3C gradually decreases from the portion connecting to the basal end portion 30P of the expansion portion 3B towards the basal end portion 3P. In this case, the balloon catheter 1B can soften the anterior end portion 3D of the anterior connecting portion 3A and the basal end portion 3P of the basal connecting portion 3C in the balloon 3. Therefore, when these portions come into contact with stents, hard lesions, etc., it is possible to prevent the balloon 3 from being held in a fully stretched state along the extension direction. Thus, it is possible to prevent unnecessary forces from the balloon 3 acting on stents, hard lesions, etc.

[0064] <Special Considerations for the Second Implementation>

[0065] The balloon 3 may have an inner thick membrane portion 4B only in the anterior connecting portion 3A, and not in the basal connecting portion 3C. The thickness of the inner thick membrane portion 4B in the anterior connecting portion 3A may also be uniform across the entire range from the portion connected to the anterior end portion 30D of the inflatable portion 3B to the anterior end portion 3D. Similarly, the thickness of the inner thick membrane portion 4B in the basal connecting portion 3C may also be uniform across the entire range from the portion connected to the basal end portion 30P of the inflatable portion 3B to the basal end portion 3P.

[0066] <Third Embodiment (Balloon Catheter 1C)>

[0067] Reference Figure 3 The balloon catheter 1C is described below. The balloon catheter 1C has an inflatable portion 3B that connects to the inner thick membrane portion 4A (see reference). Figure 1 The inner thick membrane portion 4C has a different shape than the balloon catheter 1A.

[0068] The expansion portion 3B has inner thick film portions 51, 52, 53, and 54 (hereinafter referred to as "inner thick film portion 4C" without distinction) and a thin film portion 40. The inner thick film portion 4C extends in a ring shape along the circumferential direction centered on the central axis C1. The inner thick film portions 51, 52, 53, and 54 are arranged at equal intervals in the extending direction. The thickness of the inner thick film portions 51, 52, 53, and 54 is uniform throughout the circumferential direction. Therefore, the inner diameter Ri(1) of the inner thick film portion 4C is uniform throughout the circumferential direction. That is, the amount of protrusion of the protrusion 300 formed on the inner surface 301 of the inner thick film portion 4C toward the central axis C1 is uniform throughout the circumferential direction.

[0069] <Function and Effects of the Third Implementation Method>

[0070] The inner thick membrane portion 4C of the balloon catheter 1C extends in a ring shape, thus maintaining high pressure resistance of the balloon 3 throughout the circumferential region of the expansion portion 3B even when the membrane portion 40 is relatively thin. Furthermore, the balloon catheter 1C enhances the flexibility of the balloon 3 when bent in a direction intersecting the extension direction.

[0071] <Special Considerations for the Third Implementation>

[0072] The number of inner thick film portions 4C is not limited to the above embodiment, and may be 1 to 3, or 5 or more. A portion of the circumferential direction of the inner thick film portion 4C may also be broken. The thicknesses of the inner thick film portions 51 to 54 may also be different. For example, the thickness of the inner thick film portions 51 to 54 may be thinner closer to the front end portion 30D of the expansion portion 3B. The circumferential thickness of each of the inner thick film portions 51 to 54 may also be uneven. An inner thick film portion (for example, the inner thick film portion 4A in the first embodiment) may also extend along the extending direction to connect the inner thick film portions 51 to 54. The annular inner thick film portion 4C may also be provided at the front end connecting portion 3A and the base end connecting portion 3C.

[0073] <Fourth Embodiment (Balloon Catheter 1D)>

[0074] Reference Figure 4 The balloon catheter 1D is described below. The balloon catheter 1D has an inner thick membrane portion 4B (see reference) at the distal end connection 3A, the expansion portion 3B, and the base connection 3C. Figure 2 The inner thick membrane portion 4D, with its different shape, differs from that of the balloon catheter 1B.

[0075] The front connecting portion 3A, the expansion portion 3B, and the base connecting portion 3C each have an inner thick film portion 4D and a thin film portion 40. The inner thick film portion 4D extends spirally in a circumferential direction centered on the central axis C1. The inner thick film portion 4D is disposed within the range between the front end portion 30D and the base end portion 30P of the expansion portion 3B, between the portion of the front connecting portion 3A that connects to the front end portion 30D of the expansion portion 3B and the front end portion 3D, and between the portion of the base connecting portion 3C that connects to the base end portion 30P of the expansion portion 3B and the base end portion 3P. That is, the inner thick film portion 4D extends spirally throughout the entire range between the front end portion 3D of the front connecting portion 3A and the base end portion 3P of the base connecting portion 3C.

[0076] The thickness of the inner thick film portion 4D is uniform throughout the entire region from the front end portion 3D to the base end portion 3P. Therefore, the inner diameter Ri(1) of the inner thick film portion 4D is uniform throughout the entire region from the front end portion 3D to the base end portion 3P. In addition, the helical pitch of the inner thick film portion 4D is uniform throughout the entire region from the front end portion 3D to the base end portion 3P.

[0077] <Function and Effects of the Fourth Implementation Method>

[0078] The balloon catheter 1D has a spiral-shaped inner thick membrane portion 4D at the expansion portion 3B. Therefore, the inner thick membrane portion 4D can be seamlessly positioned throughout the entire extension direction of the expansion portion 3B. Consequently, the balloon catheter 1D can maintain the high pressure resistance of the balloon 3 throughout the entire extension direction of the expansion portion 3B. Furthermore, the balloon catheter 1D improves the flexibility of the balloon 3 when the expansion portion 3B is bent in a direction intersecting the extension direction.

[0079] The balloon catheter 1D further comprises a spiral-shaped inner thick membrane portion 4D at both the anterior connecting portion 3A and the basal connecting portion 3C. Therefore, the inner thick membrane portion 4D extends over the entire range between the anterior end portion 30D of the anterior connecting portion 3A and the basal end portion 3P of the basal connecting portion 3C. In this case, the balloon catheter 1D can seamlessly configure the inner thick membrane portion 4D over the entire region of its extension direction within the range between the anterior end portion 3D and the basal end portion 3P in the balloon 3. Therefore, the balloon catheter 1D can maintain high pressure resistance of the balloon 3 over a larger range in the extension direction.

[0080] <Special Considerations for the Fourth Implementation>

[0081] The inner thick film portion 4D may be provided only in the expansion portion 3B, and not in the front end connecting portion 3A and the base end connecting portion 3C. The thickness of the inner thick film portion 4D may also be non-uniform. For example, the thickness of the inner thick film portion 4D may be smaller as it approaches the front end portion 30D or the base end portion 30P. The helical pitch of the inner thick film portion 4D may also be non-uniform. For example, the helical pitch of the inner thick film portion 4D may be smaller as it approaches the front end portion 30D or the base end portion 30P.

[0082] <Fifth Embodiment (Balloon Catheter 1E)>

[0083] Reference Figure 5 The balloon catheter 1E will be described. The balloon catheter 1E replaces the inner thick membrane portion 4A (refer to...). Figure 1 However, the balloon catheter 1A differs from the balloon catheter 3A in that the expansion portion 3B has an inner thick membrane portion 4E and an outer thick membrane portion 6E. Hereinafter, the central position in the extension direction of the expansion portion 3B of the balloon 3 will be referred to as the "central position Pc".

[0084] The expansion portion 3B has inner thick film portions 61, 62, 63 (hereinafter referred to as "inner thick film portion 4E" without distinction), outer thick film portions 64, 65, 66 (hereinafter referred to as "outer thick film portion 6E" without distinction) and thin film portion 40.

[0085] The inner thick film portions 61, 62, and 63 are arranged at equal intervals in the circumferential direction centered on the central axis C1. The inner thick film portion 4E extends along the extension direction over the entire range between the front end portion 30D of the expansion portion 3B and the central position Pc. That is, the inner thick film portion 4E is positioned closer to the front end portion 30D than the central position Pc. The outer diameter Ro(1) of the portion of the expansion portion 3B closer to the front end portion 30D than the central position Pc is the same at the inner thick film portion 4E as it is at the thin film portion 40. Therefore, the outer surface 302 of this portion becomes a smooth state without any bumps or depressions. On the other hand, the inner diameter Ri(n) of the portion of the expansion portion 3B closer to the front end portion 30D than the central position Pc is different at the inner thick film portion 4E than it is at the thin film portion 40. The inner diameter Ri(1) at the inner thick film portion 4E is smaller than the inner diameter Ri(2) at the thin film portion 40. Therefore, the inner surface 301 of this part protrudes inward at the inner thick film portion 4E, forming a protrusion 300.

[0086] The thickness of the inner thick film portion 4E is uniform across the entire range from the front end portion 30D to the central position Pc. Therefore, the inner diameter Ri(1) at the inner thick film portion 4E is uniform across the entire range from the front end portion 30D to the central position Pc. That is, the amount of protrusion of the protrusion 300 formed on the inner surface 301 of the inner thick film portion 4E toward the central axis C1 is uniform across the entire range from the front end portion 30D to the central position Pc.

[0087] The thickness of the outer thick film portion 6E is different from that of the thin film portion 40, but the same as that of the inner thick film portion 4E. The thickness of the outer thick film portion 6E is greater than that of the thin film portion 40. The outer thick film portions 64, 65, and 66 are arranged at equal intervals in the circumferential direction centered on the central axis C1.

[0088] The outer thick film portion 6E is positioned closer to the base end portion 30P than the central position Pc. The inner diameter Ri(2) of the portion of the expansion portion 3B closer to the base end portion 30P than the central position Pc is the same at the outer thick film portion 6E as it is at the thin film portion 40. Therefore, the inner surface 301 of this portion is smooth without any bumps or depressions. On the other hand, the outer diameter Ro(n) of the portion of the expansion portion 3B closer to the base end portion 30P than the central position Pc is different at the outer thick film portion 6E than it is at the thin film portion 40. The outer diameter Ro(2) of the outer thick film portion 6E is larger than the outer diameter Ro(1) at the thin film portion 40. Therefore, the outer surface 302 of this portion protrudes outward at the outer thick film portion 6E. Hereinafter, this portion will be referred to as the "protrusion 600". The outer thick film portion 6E extends along the extension direction over the entire range between the central position Pc and the base end portion 30P of the expansion portion 3B.

[0089] The thickness of the outer thick film portion 6E is uniform across the entire range from the central position Pc to the base end portion 30P. Therefore, the outer diameter Ro(2) of the outer thick film portion 6E is uniform across the entire range from the central position Pc to the base end portion 30P. That is, the amount of protrusion of the protrusion 600 formed on the outer surface 302 at the outer thick film portion 6E towards the outside is uniform across the entire range from the central position Pc to the base end portion 30P.

[0090] <Function and Effects of the Fifth Implementation Method>

[0091] The balloon 3 of the balloon catheter 1E has an inner thick membrane portion 4E located closer to the anterior end 30D than the central position Pc, and an outer thick membrane portion 6E located closer to the basal end 30P than the central position Pc. The outer thick membrane portion 6E is not located near the anterior end 30D in the expansion portion 3B of the balloon 3. Therefore, compared to having the outer thick membrane portion 6E throughout the entire extension direction of the expansion portion 3B, the balloon 3 is less likely to be held in a fully stretched state along the extension direction. Therefore, for example, during the insertion of the balloon 3 into a stent-containing vessel, even if the outer thick membrane portion 6E is hooked onto the stent, it is possible to prevent the balloon 3 from being held in a fully stretched state along the extension direction. Thus, the balloon catheter 1E can suppress unwanted forces exerted by the balloon 3 on the stent. Furthermore, the balloon catheter 1E can apply the outer thick membrane portion 6E to the lesion within the vessel during balloon 3 expansion.

[0092] <Special Considerations for the Fifth Implementation>

[0093] The boundary between the inner thick film portion 4E and the outer thick film portion 6E is not limited to the central position Pc. For example, the boundary between the inner thick film portion 4E and the outer thick film portion 6E may be positioned near the bisector of the two bisectors that divide the expansion portion 3B into three equal parts along the extending direction, close to the front end portion 30D. Alternatively, for example, the boundary between the inner thick film portion 4E and the outer thick film portion 6E may also be positioned near the bisector of the two bisectors that divide the expansion portion 3B into three equal parts along the extending direction, close to the base end portion 30P.

[0094] The inner thick film portion 4E may also be provided at the front end connecting portion 3A. In this case, the inner thick film portion 4E may also extend in the extending direction between the portion in the front end connecting portion 3A that connects to the front end portion 30D of the expansion portion 3B and the front end portion 3D. The outer thick film portion 6E may also be provided at the base end connecting portion 3C. In this case, the outer thick film portion 6E may also extend in the extending direction between the portion in the base end connecting portion 3C that connects to the base end portion 30P of the expansion portion 3B and the base end portion 3P.

[0095] The thickness of the inner thick film portion 4E and the outer thick film portion 6E may also be uneven in the extension direction. For example, the thickness of each of the inner thick film portion 4E and the outer thick film portion 6E may gradually decrease towards the central position Pc. The thickness of the inner thick film portion 4E may also gradually decrease towards the front end portion 30D. The thickness of the outer thick film portion 6E may also gradually decrease towards the base end portion 30P.

[0096] The inner surface 301 of the expansion portion 3B may also protrude inward at the outer thick film portion 6E. That is, at the outer thick film portion 6E, the outer surface 302 may protrude outward, and the inner surface 301 may protrude inward.

[0097] <Sixth Embodiment (Balloon Catheter 1F)>

[0098] Reference Figure 6 The balloon catheter 1F will be described. The balloon catheter 1F differs from the balloon catheter 1A in that it has a slit 7A in the inner thick membrane portion 4A.

[0099] In the balloon catheter 1F, slits 71, 72, 73, and 74 (hereinafter referred to as "slit 7A" without distinction) are respectively provided in the inner thick membrane portions 41 to 43. Slit 7A is an incision or resection portion provided in the protrusion 300 of the inner thick membrane portion 4A. Slit 7A has a pair of inner walls 701 facing each other in the extending direction. The pair of inner walls 701 are connected at the deepest part (hereinafter referred to as "bottom 700"). When slit 7A is an incision portion, the pair of inner walls 701 are in contact with each other. When slit 7A is a resection portion, the pair of inner walls 701 are separated in the extending direction. Furthermore, when slit 7A is a resection portion, the deeper the slit 7A, the smaller the spacing between the pair of inner walls 701 in the extending direction. Figure 6 In the example, the slit 7A of the cut portion is shown.

[0100] Slits 71, 72, 73, and 74 are arranged in this order along the extension direction. Slit 71 is closest to the anterior end 30D of the inflatable portion 3B of the balloon 3. Slit 74 is closest to the basal end 30P of the inflatable portion 3B of the balloon 3. The interval in the extension direction between slits 71 and 72 is denoted as s1. The interval in the extension direction between slits 72 and 73 is denoted as s2. The interval in the extension direction between slits 73 and 74 is denoted as s3. Interval s2 is larger than interval s1, and interval s3 is larger than interval s2. That is, the interval s in the extension direction between slits 71 and 74 is narrower the closer it is to the anterior end 30D of the inflatable portion 3B of the balloon 3.

[0101] The depth of slit 71 is denoted as d1. The depth of slit 72 is denoted as d2. The depth of slit 73 is denoted as d3. The depth of slit 74 is denoted as d4. The depth d of slit 7A corresponds to the radial length from the inner surface 301 of the balloon 3 to the bottom 700. Depth d2 is smaller than depth d1. Depth d3 is smaller than depth d2. Depth d4 is smaller than depth d3. That is, the depth d of each of slits 71 to 74 is deeper the closer it is to the anterior end 30D of the expansion portion 3B of the balloon 3.

[0102] <Function and Effects of the Sixth Implementation Method>

[0103] In balloon catheter 1F, the inner thick membrane portion 4A can be bent using slit 7A, thus allowing balloon 3 to deform well even within tortuous blood vessels. Therefore, balloon catheter 1F enables balloon 3 to follow blood vessels well.

[0104] The intervals 's' in the extension directions of each of the slits 71-74 are narrower as they approach the anterior end 30D of the expansion portion 3B. Therefore, for the balloon 3, the narrower the anterior end 30D of the intervals 's' between the slits 71-74, the easier it is to bend. In this case, when the balloon 3 is inserted toward a meandering blood vessel, it can easily follow the vessel. Thus, the user can properly position the balloon 3 to the target site. On the other hand, for the balloon 3, the wider the basal end 30P of the intervals 's' between the slits 71-74, the greater its rigidity. In this case, the stress exerted by the balloon 3 on the lesion portion of the blood vessel can be increased, thereby improving the treatment efficiency resulting from the expansion of the balloon 3.

[0105] The depth d of each of the slits 71-74 is deeper closer to the anterior end 30D. Therefore, for the balloon 3, the deeper the anterior end 30D is relative to the depth d of the slits 71-74, the easier it is to bend. In this case, when the balloon 3 is inserted towards a meandering blood vessel, it can easily follow the vessel. Thus, the user can properly position the balloon 3 to the target site. On the other hand, for the balloon 3, the closer the basal end 30P is to the depth d of the slits 71-74, the greater its rigidity. In this case, the stress exerted by the balloon 3 on the lesion of the blood vessel can be increased, thus improving the treatment efficiency resulting from the expansion of the balloon 3.

[0106] <Special Considerations for the Sixth Implementation Method>

[0107] The number of slits 7A is not limited to the above embodiment, and can be 1 to 3, or 5 or more. Different numbers of slits 7A can also be provided for the inner thick film portions 41 to 43. The positions of the slits 71 to 74 in the extension direction can also be different in the inner thick film portions 41 to 43. Slits 71 to 74 with different depths d can also be arranged at equal intervals in the extension direction. Slits 71 to 74 arranged at different intervals s can also have the same depth d in the slits 71 to 74. Slits 71 to 74 with the same depth d can also be arranged at equal intervals in the extension direction.

[0108] <Seventh Embodiment (Balloon Catheter 1G)>

[0109] Reference Figure 7 The balloon catheter 1G will be described. The balloon catheter 1G differs from the balloon catheter 1C in that it has a slit 7B at the point where the annular inner thick membrane portion 4C is located (see reference). Figure 3 )different.

[0110] Slits 76A, 76B, and 76C are provided in the inner thick film portion 51 of the expansion portion 3B. Slits 77A, 77B, and 77C are provided in the inner thick film portion 52. Slits 78A, 78B, and 78C are provided in the inner thick film portion 53. Slits 79A, 79B, and 79C are provided in the inner thick film portion 54. Without distinguishing between slits 76A-76C, 77A-77C, 78A-78C, and 79A-79C, they are referred to as "slit 7B".

[0111] Slits 76A-76C, 77A-77C, 78A-78C, and 79A-79C are arranged at equal intervals around the central axis C1. The circumferential positions of slits 76A, 77A, 78A, and 79A are consistent. The circumferential positions of slits 76B, 77B, 78B, and 79B are consistent. The circumferential positions of slits 76C, 77C, 78C, and 79C are consistent. Therefore, when viewing slit 7B from the extension direction, the positions of slits 76A, 77A, 78A, and 79A overlap; the positions of slits 76B, 77B, 78B, and 79B overlap; and the positions of slits 76C, 77C, 78C, and 79C overlap.

[0112] <Function and Effects of the Seventh Implementation Method>

[0113] The balloon catheter 1G can bend the annular inner thick membrane portion 4C using the slit 7B, thus allowing it to deform well even within tortuous blood vessels. Therefore, the balloon 3 can follow the blood vessel well.

[0114] When viewing balloon 3 from its extended direction, the positions of slits 76A, 77A, 78A, and 79A overlap; the positions of slits 76B, 77B, 78B, and 79B overlap; and the positions of slits 76C, 77C, 78C, and 79C overlap. Therefore, the balloon catheter 1G allows the portion of balloon 3 with slits 7B in the circumferential direction to be a highly flexible portion, and the portion without slits 7B to be a less flexible portion. In this case, by utilizing the highly flexible portion to bend balloon 3, balloon 3 can easily follow blood vessels when entering winding blood vessels, etc. Therefore, the user can properly guide balloon 3 to the target site.

[0115] <Special Considerations for the Seventh Implementation>

[0116] The number and position of the slits 7B provided in the inner thick film portions 51 to 54 may also be different. Alternatively, slits 7B may not be provided in a portion of the inner thick film portions 51 to 54 (e.g., the inner thick film portion 54 closest to the base end 3P). Furthermore, the slits 7B may not all overlap. For example, only the positions of slits 76A, 77A, 78A, and 79A may overlap, while the positions of slits 76B, 77B, 78B, and 79B, as well as slits 76C, 77C, 78C, and 79C, may not overlap.

[0117] <Other>

[0118] Balloon 3 is an example of a "catheter balloon" of the present invention. Anterior portion 30D is an example of a "first anterior portion" of the present invention. Base portion 30P is an example of a "first base portion" of the present invention. Anterior portion 3D is an example of a "second anterior portion" of the present invention. Base portion 3P is an example of a "second base portion" of the present invention.

Claims

1. A catheter balloon, comprising: An expansion section having a cylindrical shape extending in the extension direction; A front-end connecting portion, which extends from a first front end portion of the expansion portion on one side of the extending direction toward a side opposite to the expansion portion, wherein the diameter of the end portion connected to the expansion portion is larger than the diameter of a second front end portion that is the end portion opposite to the end portion connected to the expansion portion; and The base end connecting portion is a portion extending from the first base end end of the expansion portion on the opposite side of the extending direction to the side opposite to the expansion portion, and the diameter of the end connected to the expansion portion is larger than the diameter of the second base end end, which is the end connected to the opposite side of the end of the expansion portion. The balloon for catheterization is characterized in that... The catheter balloons each have an inner thick membrane portion and a thin membrane portion of different thicknesses. The thickness of the inner thick film portion is greater than that of the thin film portion. The inner surface of the inner thick film portion protrudes radially inward towards a central axis that passes through the center of the expansion portion and extends along the extension direction, compared to the inner surface of the thin film portion. The outer surface of the inner thick film portion does not protrude radially outward relative to the outer surface of the thin film portion. The inner thick film portion is provided in the expansion portion, the front end connecting portion, and the base end connecting portion. The inner thick film portion extends along the extension direction over the entire range from the second front end portion to the second base end portion. The thickness of the inner thick film portion of the front end connector gradually decreases from the portion connected to the first front end of the expansion portion toward the second front end. The thickness of the inner thick film portion of the base end connection gradually decreases from the portion connected to the first base end of the expansion portion toward the second base end.

2. The balloon for catheterization according to claim 1, characterized in that, The outer diameter, which is the radial distance from the central axis to the outer surface, is the same at the thin film portion as it is at the inner thick film portion. The inner diameter, which is the radial distance from the central axis to the inner surface, is smaller at the inner thick film portion than at the thin film portion.

3. The catheter balloon according to claim 1 or 2, characterized in that, The inner thick film portion extends along the extension direction.

4. The balloon for catheterization according to claim 3, characterized in that, The expansion portion is provided with the inner thick film portion. The inner thick film portion extends along the extension direction over the entire range from the first front end portion to the first base end portion.

5. The balloon for catheterization according to claim 2, characterized in that, The expansion portion is provided with an outer thick film portion and an inner thick film portion, both of which have a greater thickness than the thin film portion. The inner diameter is the same at the thin film portion and at the outer thick film portion. The outer diameter is larger at the outer thick film portion than at the thin film portion. The inner thick film portion and the outer thick film portion extend along the extending direction and are arranged in the extending direction. The inner thick film portion is closer to the first front end portion than the outer thick film portion, and the outer thick film portion is closer to the first base end portion than the inner thick film portion.

6. The catheter balloon according to claim 4 or 5, characterized in that, At least one slit is provided in the inner thick film portion.

7. The balloon for catheterization according to claim 6, characterized in that, The catheter balloon is provided with a plurality of slits arranged in the direction of extension. The spacing between the plurality of slits in their respective extension directions becomes narrower as they approach the second front end.

8. The balloon for catheterization according to claim 6, characterized in that, The catheter balloon is provided with a plurality of slits arranged in the direction of extension. The depth of each of the plurality of slits increases as it approaches the second front end.

9. The balloon for catheterization according to claim 1, characterized in that, The inner thick film portion is in the form of a ring extending circumferentially around the central axis.

10. The balloon for catheterization according to claim 1, characterized in that, The inner thick film portion is spirally extended circumferentially around the central axis and is disposed over the entire range between the first front end portion and the first base end portion.

11. The balloon for catheterization according to claim 10, characterized in that, The inner thick film portion is provided over the entire range between the second front end portion and the second base end portion.

12. The catheter balloon according to any one of claims 9 to 11, characterized in that, At least one slit is provided in the inner thick film portion.

13. The catheter balloon according to claim 12, characterized in that, The catheter balloon is provided with a plurality of slits arranged in the direction extending from the inner thick membrane portion. When viewed from the direction of extension, each of the plurality of slits is configured at a position that overlaps with at least one of the other slits.

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