Balloon for balloon catheter

Abstract

Provided is a balloon for a balloon catheter with which it is possible to cut a narrowed section obliquely or widely in a contracted state.　This balloon for a balloon catheter is provided with a balloon body (20) and a protrusion (60) having a distal end portion (61), and satisfies (1) and / or (2) below.　(1) In the contracted state, the distal end portion (61) in a distal tapered section (24) is disposed on the side in the first direction C1 of the circumferential direction of the balloon body (20) relative to the straight line Ld, and is not disposed on the side in the second direction C2.　(2) In the contracted state, the distal end portion (61) in a proximal tapered section (22) is disposed on the side in the first direction C1 of the circumferential direction of the balloon body (20) relative to the straight line Lp, and is not disposed on the side in the second direction C2.

Description

[Technical Field]

[0001] The present invention relates to a balloon for a balloon catheter. [Background technology]

[0002] The formation of narrowed areas due to calcification and other factors in the inner walls of blood vessels can lead to diseases such as angina pectoris and myocardial infarction. One treatment for these conditions is angioplasty, which uses a balloon catheter to dilate the narrowed area. Angioplasty is a minimally invasive treatment that does not require open chest surgery like bypass surgery, and is widely used.

[0003] In angioplasty, conventional balloon catheters can be difficult to dilate stenotic areas that have hardened due to calcification or other factors. While a method of dilating stenotic areas by placing an indwelling dilation device called a stent at the stenotic area is also used, this treatment can sometimes result in excessive neointima growth in the blood vessel, causing recurrence of vascular stenosis, a condition known as in-stent restenosis (ISR). In ISR lesions, the neointima is soft and has a slippery surface, so when a conventional balloon catheter is used to dilate the balloon, it can slip out of position and damage the blood vessel.

[0004] Balloon catheters that can dilate stenotic lesions, even in calcified or ISR lesions, have been developed, including balloon catheters with protrusions, blades, or scoring elements that penetrate the stenotic lesion. For example, Patent Document 1 discloses a balloon catheter with scoring elements made of a polymeric material with higher rigidity than the polymeric material forming the balloon body, and the scoring elements are flattened at one and the other ends of the balloon. Patent Document 2 discloses a scoring balloon structure in which the height of the scoring elements decreases along the tapered shape of the balloon, and Patent Document 3 discloses a balloon catheter in which the straight portion of the balloon is provided with an outer protrusion and the tapered portion is provided with an inner protrusion. In Patent Documents 1 to 3, the height of the scoring elements decreases at both ends of the balloon, or inner protrusions are provided instead of outer protrusions. In contrast, there is also a balloon catheter with a high protrusion, in which the protrusions located at the distal tapered portion of the balloon are greater than the protrusions located at the straight portion (Patent Document 4). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] US Patent Application Publication No. 2016 / 0128718 [Patent Document 2] Special Publication No. 2014-506140 [Patent Document 3] International Publication No. 2020 / 012851 Brochure [Patent Document 4] International Publication No. 2020 / 012850 Brochure Summary of the Invention [Problem to be solved by the invention]

[0006] Balloon catheters are inserted into body cavities in a deflated and folded state and delivered to the treatment site. Therefore, the balloon catheters disclosed in Patent Documents 1 to 3 attempt to improve the penetrability of the balloon by reducing the height of the scoring element at the distal end of the balloon to prevent an increase in outer diameter and facilitate easier insertion into body cavities. Furthermore, the balloon catheter disclosed in Patent Document 4 has a high protrusion on the distal tapered section so that when only the distal cone region is introduced into the lesion and the balloon is inflated, the element provided in the distal cone region can incise the lesion while inflating the balloon. However, none of these balloons were designed to allow the balloon to be advanced or retracted in a deflated state to make an oblique incision in a stricture or to incise a wide area in a single movement.

[0007] In view of the above circumstances, an object of the present invention is to provide a balloon for a balloon catheter that can make an oblique incision or a wide incision in the stenotic area in a deflated state during delivery of the balloon or when the balloon is delivered to the lesion area. [Means for solving the problem]

[0008] One embodiment of the balloon for a balloon catheter of the present invention that can solve the above-mentioned problems is a balloon for a balloon catheter having a balloon body with an outer surface and an inner surface, wherein the balloon body has a straight tube section, a distal tapered section located distal to the straight tube section, and a proximal tapered section located proximal to the straight tube section, and the distal tapered section, the straight tube section, and the proximal tapered section have protruding portions that protrude radially outward from the outer surface of the balloon body and extend in the longitudinal axis direction of the balloon body, and the protruding portions have tip portions in a radial cross section of the balloon body, and at least one of the following (1) and (2) is satisfied. (1) When the balloon for the balloon catheter is in a deflated state, the tip of the protruding portion of the distal tapered portion is aligned with a straight line L connecting the tip of the proximal end of the distal tapered portion and the tip of the distal end of the distal tapered portion.d In contrast, the circumferential surface of the balloon body is arranged on the first direction side and not on the second direction side, or is arranged on the second direction side and not on the first direction side. (2) When the balloon for the balloon catheter is in a deflated state, the tip of the protruding portion of the proximal tapered portion is aligned along a straight line L connecting the tip of the distal end of the proximal tapered portion and the tip of the proximal end of the proximal tapered portion. p In contrast, the circumferential surface of the balloon body is arranged on the first direction side and not on the second direction side, or is arranged on the second direction side and not on the first direction side.

[0009] In the deflated state of the balloon for a balloon catheter, the balloon for a balloon catheter is preferably folded.

[0010] In the deflated state of the balloon for a balloon catheter, when the ends of the straight tube section of the distal tapered section and the proximal tapered section in the longitudinal axis direction of the balloon body are defined as 0% and the other ends are defined as 100%, it is preferable that at least one of the following (1) and (2) be satisfied: (1) The tip of the protrusion in the entire section from the 20% position to the 70% position of the distal tapered section is a straight line L d The tip of the protrusion in the section from the 90% position to the 100% position of the distal tapered portion is aligned with a straight line L d are not arranged on the first direction side or the second direction side. (2) The tip of the protrusion in the entire section from the 20% position to the 70% position of the proximal tapered section is a straight line L p The tip of the protruding portion in the section from the 90% position to the 100% position of the proximal tapered portion is aligned with a straight line L p are not arranged on the first direction side or the second direction side. In this case, it is preferable that at least one of the following (1) and (2) is satisfied. (1) The straight line L at the tip of the protrusion at the 40% position of the distal tapered section dThe distance from the tip of the protrusion at 60% of the distal taper is the straight line L d It is more than 1.2 times the distance from (2) The straight line L at the tip of the protrusion at the 40% position of the proximal taper p The distance from the proximal taper is the straight line L p It is more than 1.2 times the distance from

[0011] In a deflated state, the balloon for a balloon catheter preferably satisfies at least one of the following (1) and (2): (1) The tip of the protrusion in the entire section from the 20% position to the 70% position of the distal tapered section is a straight line L d The balloon is disposed radially inward of the balloon body or at the same position as the imaginary curved surface obtained by rotating the balloon around the central axis of the balloon body. (2) The tip of the protrusion in the entire section from the 20% position to the 70% position of the proximal tapered section is a straight line L p The balloon is disposed radially inward of the balloon body or at the same position as the imaginary curved surface obtained by rotating the balloon around the central axis of the balloon body.

[0012] When the balloon for a balloon catheter is in an expanded state, it is preferable that the tip of the protruding portion of the distal tapered portion, the tip of the protruding portion of the straight tube portion, and the tip of the protruding portion of the proximal tapered portion are located at the same circumferential position of the balloon body.

[0013] The balloon body has wing forming portions that form wings in a deflated state, and the protrusions are preferably arranged outside the wing forming portions.

[0014] It is preferable that the protruding portion of the distal tapered section, the protruding portion of the straight tube section, and the protruding portion of the proximal tapered section extend continuously in the longitudinal axis direction of the balloon body.

[0015] The protrusions are preferably made of the same material as the balloon body.

[0016] The present invention also provides a method for producing the above-described balloon for a balloon catheter. A manufacturing method according to one embodiment of the present invention includes the steps of: preparing a first cylindrical body, a second cylindrical body, and a third cylindrical body, each having an internal space extending in the longitudinal direction; preparing a balloon for a balloon catheter, the balloon having an outer surface and an inner surface, the balloon body having a straight tube section, a distal tapered section located distal to the straight tube section, and a proximal tapered section located proximal to the straight tube section, the distal tapered section, the straight tube section, and the proximal tapered section having protrusions that protrude radially outward from the outer surface of the balloon body and extend in the longitudinal direction of the balloon body; and arranging the distal tapered section in the first cylindrical body, the proximal tapered section in the second cylindrical body, and the straight tube section in the third cylindrical body when the balloon for a balloon catheter is in a deflated state, and the manufacturing method satisfies at least one of the following (1) and (2). (1) In the positioning step, the inner surface of the first cylindrical object and at least a part of the protruding portion of the distal tapered portion are in contact with each other. (2) In the positioning step, the inner surface of the second cylindrical object and at least a part of the protruding portion of the proximal tapered portion are in contact with each other. [Effects of the Invention]

[0017] According to the above-mentioned balloon for balloon catheter, when the balloon is in a deflated state, the tip of at least one of the protruding portions of the distal tapered portion and the proximal tapered portion is positioned on the first circumferential side of the balloon and not on the second circumferential side, or on the second circumferential side and not on the first circumferential side. Therefore, during delivery of the balloon or when the balloon has been delivered to the lesion, the balloon can be advanced or retracted in the deflated state to make an oblique incision in the narrowed portion or an incision over a wide area. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a side view of a balloon catheter according to an embodiment of the present invention. [Figure 2] 2 is a longitudinal sectional view of the balloon catheter shown in FIG. 1 in an expanded state of the balloon. [Figure 3] FIG. 3 shows a cross-sectional view taken along the line III-III in FIG. [Figure 4] 3 is a radial cross-sectional view of the straight tube portion of the balloon shown in FIG. 2 in a contracted state. [Figure 5] 3 shows a radial cross-sectional view of the tapered portion of the balloon shown in FIG. 2 in a contracted state. [Figure 6] 3 is a plan view of the balloon shown in FIG. 2 in a deflated state, as viewed from the protruding portion side. [Figure 7] FIG. 10 is a plan view of a balloon according to another embodiment of the present invention in a deflated state, as viewed from the protruding portion side. [Figure 8] FIG. 10 is a plan view of a balloon according to yet another embodiment of the present invention in a deflated state, as viewed from the protrusion side. [Figure 9] FIG. 10 is a plan view of a balloon according to yet another embodiment of the present invention in a deflated state, as viewed from the protrusion side. [Figure 10] FIG. 10 is a plan view of a balloon according to yet another embodiment of the present invention in a deflated state, as viewed from the protrusion side. [Figure 11] FIG. 10 is a plan view of a balloon according to yet another embodiment of the present invention in a deflated state, as viewed from the protrusion side. [Figure 12] FIG. 10 is a plan view of a balloon according to yet another embodiment of the present invention in a deflated state, as viewed from the protrusion side. [Figure 13] FIG. 10 is a plan view of a balloon according to yet another embodiment of the present invention in a deflated state, as viewed from the protrusion side. [Figure 14] 3 shows a side view of the balloon shown in FIG. 2 in a folded state. [Figure 15] 15 shows a cross-sectional view taken along the line XV-XV in FIG. 14. [Figure 16] 16 shows a cross-sectional view taken along the line XVI-XVI in FIG. 14. [Figure 17] 17A and 17B show cross-sectional views taken along the line XVII-XVII in FIG. 14 [Figure 18]FIG. 10 is a plan view of a balloon according to another embodiment of the present invention in a deflated state, as viewed from the protruding portion side. [Figure 19] FIG. 10 is a plan view of a balloon according to yet another embodiment of the present invention in a deflated state, as viewed from the protrusion side. [Figure 20] 3 shows a partial side view of the balloon shown in FIG. 2 in a deflated state. [Figure 21] 3 shows a plan view of the balloon shown in FIG. 2 as seen from the protruding portion side. [Figure 22] FIG. 2 illustrates a perspective view of a parison prior to expansion according to one embodiment of the present invention. [Figure 23] 2 is a cross-sectional view perpendicular to the longitudinal axis direction of a first cylindrical object or a second cylindrical object in a manufacturing method according to one embodiment of the present invention. FIG. [Figure 24] 1A and 1B show radial cross-sectional views of a manufacturing method according to one embodiment of the present invention, in which a distal tapered portion is positioned within a first cylindrical body or a proximal tapered portion is positioned within a second cylindrical body. [Figure 25] 25 shows a radial cross-sectional view of the first cylindrical object or the second cylindrical object shown in FIG. 24 at another location in the longitudinal axis direction. [Figure 26] 25 is a radial cross-sectional view of the first cylindrical object or the second cylindrical object shown in FIG. 24 at yet another location in the longitudinal axis direction. [Figure 27] 4 is a cross-sectional view in the radial direction of a third cylindrical object in a manufacturing method according to an embodiment of the present invention. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0019] The present invention will be described in detail below based on the embodiments, but the present invention is not limited to the following embodiments and can be implemented with appropriate modifications within the scope of the above and below-described purpose, and all such modifications are included within the technical scope of the present invention. In addition, hatching and component symbols may be omitted in each drawing for convenience. In such cases, reference should be made to the specification or other drawings. The dimensions of various components in the drawings may differ from actual dimensions, as priority is given to helping understand the features of the present invention.

[0020] A balloon for a balloon catheter according to one embodiment of the present invention has a balloon body having an outer surface and an inner surface, the balloon body having a straight tube section, a distal tapered section located distal to the straight tube section, and a proximal tapered section located proximal to the straight tube section, the distal tapered section, the straight tube section, and the proximal tapered section having protruding portions that protrude radially outward from the outer surface of the balloon body and extend in the longitudinal axis direction of the balloon body, the protruding portions having a tip portion in a radial cross section of the balloon body, and satisfying at least one of the following (1) and (2): (1) When the balloon for the balloon catheter is in a deflated state, the tip of the protruding portion of the distal tapered portion is aligned with a straight line L connecting the tip of the proximal end of the distal tapered portion and the tip of the distal end of the distal tapered portion. d In contrast, the circumferential surface of the balloon body is arranged on the first direction side and not on the second direction side, or is arranged on the second direction side and not on the first direction side. (2) When the balloon for the balloon catheter is in a deflated state, the tip of the protruding portion of the proximal tapered portion is aligned along a straight line L connecting the tip of the distal end of the proximal tapered portion and the tip of the proximal end of the proximal tapered portion. p In contrast, the circumferential surface of the balloon body is arranged on the first direction side and not on the second direction side, or is arranged on the second direction side and not on the first direction side. In this way, when the balloon is in a deflated state, the tip of at least one of the protruding portions of the distal tapered portion and the proximal tapered portion is disposed on the first or second circumferential side of the balloon body, so that during delivery of the balloon or when the balloon has been delivered to the lesion, the balloon can be advanced or retracted in a deflated state to incise the stenotic portion obliquely or to incise a wide area in a single movement. In this specification, a balloon for a balloon catheter may be simply referred to as a "balloon."

[0021] A balloon for a balloon catheter will be described with reference to Figures 1 to 21. Figure 1 shows a side view of a balloon catheter according to one embodiment of the present invention, Figure 2 shows a longitudinal cross-sectional view of the balloon of the balloon catheter shown in Figure 1 in an expanded state, and Figure 3 shows a cross-sectional view taken along line III-III of Figure 1. Figure 4 shows a radial cross-sectional view of the straight section of the balloon shown in Figure 2 in a contracted state, and Figure 5 shows a radial cross-sectional view of the tapered section of the balloon shown in Figure 2 in a contracted state. Figure 6 shows a plan view of the balloon shown in Figure 2 in a contracted state, as seen from the protruding portion side, and Figures 7 to 13 show plan views of balloons according to different embodiments, as seen from the protruding portion side, in a contracted state. Figure 14 shows a side view of the balloon shown in Figure 2 in a folded state, and Figures 15, 16, and 17 show cross-sectional views of the balloon shown in Figure 14 taken along lines XV-XV, XVI-XVI, and XVII-XVII, respectively. Figures 18 and 19 are plan views of a balloon according to another embodiment in a deflated state, as viewed from the protruding portion side. Figure 20 is a partial side view of the balloon shown in Figure 2 in a deflated state, i.e., a view from the side of a portion where one protrusion is formed along the balloon body. Figure 21 is a plan view of the balloon shown in Figure 2, as viewed from the protruding portion side.

[0022] In the present invention, the proximal side refers to the direction toward the user or surgeon in the direction of extension of the balloon catheter 1 or the longitudinal axis direction x of the shaft 3, and the distal side refers to the opposite side of the proximal side, i.e., the direction toward the patient. Even components other than elongated members such as the shaft 3 have the same longitudinal axis direction x as the shaft 3. The radial direction y is a direction perpendicular to the longitudinal axis direction x, connecting the center of the balloon body 20 to a point on the circumscribing circle of the balloon body 20 in a cross section perpendicular to the longitudinal axis direction x. The circumferential direction z is a direction along the circumference of the circumscribing circle of the balloon body 20 in an expanded state in a cross section perpendicular to the longitudinal axis direction x.

[0023] As shown in Figures 1 and 2, the balloon catheter 1 has a shaft 3 and a balloon 2 provided on the outside of the shaft 3. The balloon catheter 1 has a distal side and a proximal side, and the balloon 2 is provided on the distal side of the shaft 3. The balloon catheter 1 is configured so that a fluid is supplied to the inside of the balloon 2 through the shaft 3, and the expansion and contraction of the balloon 2 can be controlled using an indeflator (balloon pressurizer). The fluid may be a pressurized fluid pressurized by a pump or the like.

[0024] The shaft 3 preferably has an internal fluid flow path and further has a guidewire insertion path. An example of a configuration in which the shaft 3 has an internal fluid flow path and a guidewire insertion path is a configuration in which the shaft 3 has an outer tube 31 and an inner tube 32, the inner tube 32 functions as a guidewire insertion path, and the space between the inner tube 32 and the outer tube 31 functions as a fluid flow path. In this configuration in which the shaft 3 has the outer tube 31 and the inner tube 32, it is preferable that the inner tube 32 extends from the distal end of the outer tube 31 and penetrates distally of the balloon 2, the distal side of the balloon 2 is joined to the inner tube 32, and the proximal side of the balloon 2 is joined to the outer tube 31.

[0025] As shown in Figures 1 to 13, the balloon 2 for the balloon catheter 1 has a balloon body 20 having an outer surface and an inner surface. The balloon body 20 has a straight tube section 23, a distal tapered section 24 located distal to the straight tube section 23, and a proximal tapered section 22 located proximal to the straight tube section 23. The distal tapered section 24, the straight tube section 23, and the proximal tapered section 22 have protruding portions 60 that protrude radially outward from the outer surface of the balloon body 20 and extend in the longitudinal axis direction x of the balloon body 20. The protruding portion 60 has a tip portion 61 in a cross section of the balloon body 20 in the radial direction y, and satisfies at least one of the following (1) and (2). (1) When the balloon 2 for the balloon catheter 1 is in a deflated state, the tip 61 of the protruding portion 60 of the distal tapered portion 24 is aligned along a straight line L connecting the tip 61 at the proximal end of the distal tapered portion 24 and the tip 61 at the distal end of the distal tapered portion 24. d In contrast, they are arranged on the first direction C1 side of the circumferential direction z of the balloon body 20 and not on the second direction C2 side, or they are arranged on the second direction C2 side and not on the first direction C1 side. (2) When the balloon 2 for the balloon catheter 1 is in a deflated state, the tip 61 of the protruding portion 60 of the proximal tapered portion 22 is aligned along a line L connecting the tip 61 of the distal end of the proximal tapered portion 22 and the tip 61 of the proximal end of the proximal tapered portion 22. p In contrast, they are arranged on the first direction C1 side of the circumferential direction z of the balloon body 20 and not on the second direction C2 side, or they are arranged on the second direction C2 side and not on the first direction C1 side. When the balloon 2 is in a deflated state, the tip 61 of at least one of the protrusions 60 of the distal tapered portion 24 and the proximal tapered portion 22 is arranged on the first direction C1 side or the second direction C2 side of the circumferential direction z of the balloon body 20. Therefore, during delivery of the balloon 2 or when the balloon 2 is delivered to the lesion, the balloon 2 can be advanced or retreated in the deflated state to incise the narrowed area diagonally or to incise a wide area in a single movement.

[0026] 2, the balloon 2 may have a non-expandable distal sleeve portion 25 and a non-expandable proximal sleeve portion 21 located distally of the distal tapered portion 24 and proximally of the proximal tapered portion 22, respectively. At least a portion of the distal sleeve portion 25 and the proximal sleeve portion 21 may be fixed to the shaft 3, and in the case where the shaft 3 has an outer tube 31 and an inner tube 32, at least a portion of the proximal sleeve portion 21 may be fixed to the outer tube 31, and at least a portion of the distal sleeve portion 25 may be fixed to the inner tube 32.

[0027] The distal tapered portion 24 and the proximal tapered portion 22 are preferably formed so that their diameters decrease with increasing distance from the straight tube portion 23. Because the balloon body 20 has the straight tube portion 23, which has the largest diameter in the expanded state, when the balloon 2 is expanded at a stricture, the straight tube portion 23 makes sufficient contact with the stricture, facilitating dilation and incision of the stricture. Furthermore, as described below, wings 29 are formed when the balloon 2 is deflated. Since the balloon body 20 has the distal tapered portion 24 and the proximal tapered portion 22, the outer diameters of which decrease with increasing distance from the straight tube portion 23, when the balloon 2 is deflated and the wings 29 are wound around the shaft 3, the protruding portions 60 in the distal tapered portion 24 and the proximal tapered portion 22 can be exposed from the wings 29 of the balloon 2. These exposed protruding portions 60 allow the stricture to be incised even when the balloon 2 is deflated.

[0028] As shown in Figures 2 and 3, the protrusions 60 of the balloon 2 are portions that protrude radially outward in the y direction from the outer surface of the balloon body 20 when the balloon 2 is inflated. The maximum length by which the protrusions 60 protrude radially outward in the y direction from the outer surface of the balloon body 20 in the radial y cross section is preferably at least 1.2 times the thickness of the balloon body 20, more preferably at least 1.5 times, and even more preferably at least 2 times. It is also acceptable for the protrusions 60 to be at most 100 times, 50 times, 30 times, or 10 times. This makes it easier for the protrusions 60 to make incisions of an appropriate depth in the stricture, facilitating incision. Furthermore, the protrusions 60 can improve the strength of the balloon 2 and prevent the balloon 2 from over-expanding when pressurized.

[0029] The number of protrusions 60 in the circumferential direction z of the balloon 2 may be one, or may be multiple as shown in Figure 3. When the balloon 2 has multiple protrusions 60 in the circumferential direction z, the multiple protrusions 60 are preferably spaced apart in the circumferential direction z, and more preferably arranged at equal intervals in the circumferential direction z. The distance of separation is preferably longer than the maximum circumferential length of the protrusions 60. Arranging the protrusions 60 at intervals in the circumferential direction z, preferably at equal intervals, makes it easier to fix the balloon 2 and to incise the stricture.

[0030] As shown in FIG. 3 , the protrusions 60 have a tip 61 in a cross section taken along the radial direction y of the balloon body 20. The tip 61 facilitates incision into the stenotic site, allowing the stenotic site to be incised while preventing dissection of the vascular intima. The tip 61 is the portion of the protrusion 60 that protrudes furthest outward in the radial direction y from the outer surface of the balloon body 20, and may have a shape with an acute angle as shown in FIG. 3 , an obtuse angle, a curved shape, or a flat shape. From the viewpoint of ease of incision, a shape with an acute angle is preferable. The shape of the protrusions 60 in a cross section taken along the radial direction y may be any shape, including a substantially triangular shape as shown in FIG. 3 , a polygonal, fan-shaped, wedge-shaped, convex, spindle-shaped, etc.

[0031] 4 and 5, the deflated state of the balloon 2 is the state after fluid has been discharged from the interior of the balloon 2 or before fluid is supplied to the interior of the balloon 2, and in the deflated state of the balloon 2, the inner surface of the balloon body 20 has a portion close to the shaft 3 and wings 29 formed thereon. In other words, as shown in Fig. 3, the expanded balloon 2 has wing-forming portions 28 that form wings 29 in the deflated state. In the embodiment shown in Figs. 4 and 5, the shaft 3 has an outer tube 31 and an inner tube 32, and in the deflated state of the balloon 2, the inner surface of the balloon body 20 has a portion close to the inner tube 32. 4, which shows a cross-section in the radial direction y of the straight tubular section 23 in a contracted state, with FIG. 5, which shows a cross-section in the radial direction y of a tapered section (distal tapered section 24 or proximal tapered section 22). As can be seen from a comparison between the straight tubular section 23, which is the section of the balloon 2 that has the largest diameter in an expanded state, and the tapered section, which is the section with a reduced diameter, the length in the radial direction y of the blades 29 of the straight tubular section 23 is longer than the length in the radial direction y of the blades 29 of the tapered section. If the distal tapered section 24 and the proximal tapered section 22 are gradually reduced in diameter toward the distal and proximal sides, respectively, the length in the radial direction y of the blades 29 in the radial direction y cross-section also gradually decreases toward the distal and proximal sides, respectively. Consequently, blades 29 may not be formed in the distal portion of the distal tapered section 24 and the proximal portion of the proximal tapered section 22. It is preferable that no wings 29 are formed at the distal end of distal tapered section 24 and the proximal end of proximal tapered section 22. If wings 29 are not formed at the distal end portion of distal tapered section 24 and the proximal end portion of proximal tapered section 22, protrusion 60 can abut against the body cavity wall at those portions without being hindered by wings 29, making it possible to incise the stricture.

[0032] As shown in FIGS. 6 to 13, when the balloon 2 is in a deflated state, the tip end 61 of the protruding portion 60 of at least one of the distal tapered portion 24 and the proximal tapered portion 22 is aligned along a straight line L. d and the line L pIn contrast, the distal tapered portion 24 and the proximal tapered portion 22 are each independently arranged in the first direction C1 and not in the second direction C2 in the circumferential direction z of the balloon body 20, or arranged in the second direction C2 and not in the first direction C1. That is, the tip end 61 of the protruding portion 60 of at least one of the distal tapered portion 24 and the proximal tapered portion 22 is aligned with the straight line L. d and the line L p 6 to 13 show an embodiment in which the tip end 61 of the protruding portion 60 of the entire section from the distal end to the proximal end of at least one of the distal tapered portion 24 and the proximal tapered portion 22 is arranged on the first direction C1 side or the second direction C2 side, but it is sufficient that the tip end 61 of the protruding portion 60 of at least one of the distal tapered portion 24 and the proximal tapered portion 22 has at least a part arranged on the first direction C1 side or the second direction C2 side, and the other part is arranged on the straight line L. d Or straight line L p It may be placed on top.

[0033] As shown in FIGS. 6 and 7, the distal end portions 61 of the protruding portions 60 of both the distal tapered portion 24 and the proximal tapered portion 22 are aligned along a straight line L d and the line L p With this configuration, the distal tapered portion 24 and the tip 61 of the protruding portion 60 of the proximal tapered portion 22 can be arranged on the same side in the circumferential direction z, so that the tip 61 can be arranged on the same side in the circumferential direction z when the balloon 2 is advanced and retreated within the body cavity, and both the distal tapered portion 24 and the tip 61 of the protruding portion 60 of the proximal tapered portion 22 can be used to make oblique incisions on the same side of the body cavity wall in the circumferential direction z or to incise a wide area in a single movement.

[0034] As shown in FIGS. 8 and 9, the tip 61 of the protrusion 60 of the distal tapered portion 24 is aligned along a straight line L d The proximal tapered portion 22 is disposed on the first direction C1 side or the second direction C2 side with respect to the first direction C1 side or the second direction C2 side. pThe distal tapered portion 24 may be disposed on the second direction C2 side or the first direction C1 side, opposite to the distal tapered portion 24. With this configuration, the distal tapered portion 24 and the proximal tapered portion 22 can have the tip portions 61 of the protrusions 60 on different sides in the circumferential direction z, and therefore the tip portions 61 can be disposed on different sides in the circumferential direction z when the balloon 2 is advanced and retracted within the body cavity, making it possible to make oblique incisions at different locations when the balloon 2 is advanced and retracted, or to make an incision over a wider area in a single movement.

[0035] As shown in FIGS. 10 and 11, the tip 61 of the protruding portion 60 of the proximal tapered portion 22 is aligned along a straight line L p The distal tapered portion 24 is disposed on the first direction C1 side or the second direction C2 side with respect to the first direction C1 side or the second direction C2 side. d With this configuration, only the tip 61 of the protruding portion 60 of the proximal tapered portion 22 can be disposed on the first direction C1 side or the second direction C2 side in the circumferential direction z, and the tip 61 of the protruding portion 60 of the distal tapered portion 24 is not curved in the circumferential direction z. Therefore, while the tip 61 of the distal tapered portion 24 makes a straight incision, for example, the tip 61 of the proximal tapered portion 22 can be used to make an oblique incision while retracting the balloon 2, or to incise a wide area in a single movement.

[0036] As shown in FIGS. 12 and 13, the tip 61 of the protrusion 60 of the distal tapered portion 24 is aligned along a straight line L d The proximal tapered portion 22 is disposed on the first direction C1 side or the second direction C2 side with respect to the first direction C1 side or the second direction C2 side. pWith this configuration, only the tip 61 of the protruding portion 60 of the distal tapered portion 24 can be disposed on the first direction C1 side or the second direction C2 side of the circumferential direction z, and the tip 61 of the protruding portion 60 of the proximal tapered portion 22 is not curved in the circumferential direction z. Therefore, while the tip 61 of the proximal tapered portion 22 makes a straight incision, the tip 61 of the distal tapered portion 24 can be used to make an oblique incision or to incise a wide area in a single movement while, for example, advancing the balloon 2.

[0037] As described above, by appropriately selecting various modes such as those shown in Figures 6 to 13, it is possible to obtain the balloon 2 that is most suitable for treating the lesion at the treatment target site. d and the line L p extends in the longitudinal axis direction x, but the straight line L d and the line L p may extend at an angle in the circumferential direction z with respect to the longitudinal axis direction x.

[0038] 6 to 13 show an embodiment in which the distal sleeve portion 25 and the proximal sleeve portion 21 also have a protrusion 60, but the distal sleeve portion 25 and the proximal sleeve portion 21 do not have to have a protrusion 60, and the distal sleeve portion 25 and the proximal sleeve portion 21 may have an inner protrusion that protrudes inward in the radial direction y beyond the inner surface of the balloon body 20. If the distal sleeve portion 25 and the proximal sleeve portion 21 do not have a protrusion 60, it will be easier to insert the balloon 2 into a body cavity and to move it forward and backward within the body cavity.

[0039] With regard to the length of the protrusion 60 in the radial direction y in the cross section in the radial direction y, the length of the protrusion 60 in the distal tapered portion 24 or the proximal tapered portion 22 is preferably shorter than the length of the protrusion 60 in the straight tube portion 23. In addition, in the expanded state, the tip end 61 of the protrusion 60 in the distal tapered portion 24 and the proximal tapered portion 22 is aligned along the straight line L d and L pThis reduces the risk that, when the balloon 2 is in an expanded state, the tip 61 of the protrusion 60 in the tapered portion other than the straight tube portion 23 that acts on the lesion will come into contact with normal blood vessels or other areas that are not the target of treatment.

[0040] As shown in Figures 14 to 17, the balloon 2 is preferably folded when it is in a deflated state. When the balloon 2 is in a folded state, the blades 29 formed by the deflation of the balloon 2 shown in Figures 4 and 5 are wound around the shaft 3. In the straight tube section 23 having the largest diameter, the length of the blades 29 in the radial direction y is long, and therefore the amount of the blades 29 wound around the shaft 3 is large, as shown in Figure 15. On the other hand, in the distal tapered section 24 and the proximal tapered section 22, which are reduced in diameter, the length of the blades 29 in the radial direction y is shortened due to the reduced diameter, and in one embodiment of the present invention, the length becomes shorter as it goes further distally and further proximally. In one embodiment of the present invention, in the distal tapered section 24 and the proximal tapered section 22 near the straight tube section 23, shorter wings 29 than those in the straight tube section 23 are wound around the shaft 3 (inner tube 32) as shown in Fig. 16 , and in the more distal and more proximal sections, even shorter wings 29 are wound around the shaft 3 (inner tube 32) as shown in Fig. 17 . Alternatively, by adjusting the diameter of the balloon 2 and the number of wings 29, it is possible to reduce the amount of winding of the wings 29 around the distal tapered section 24 and the proximal tapered section 22 near the straight tube section 23 as shown in Fig. 17 , or even to eliminate the wings 29 completely. By folding the balloon 2, the balloon 2 can be easily inserted into a body cavity.

[0041] As shown in FIG. 18, when the balloon 2 is in a deflated state, the ends of the distal tapered portion 24 and the proximal tapered portion 22 on the straight tube portion 23 side in the longitudinal axis direction x of the balloon body 20 are at a 0% position D0, and the other ends are at a 100% position D 100 When the above condition is satisfied, it is preferable that at least one of the following conditions (1) and (2) is satisfied. (1) Position D at 20% of the distal tapered portion 2420 from the position D of 70% 70 The tip 61 of the protrusion 60 in the entire section up to is on the first direction C1 side or the second direction C2 side with respect to the straight line L d and is arranged on the first direction C1 side or the second direction C2 side with respect to the straight line L, and the position D of 90% of the distal tapered portion 24 90 from the position D of 100% 100 The tip 61 of the protrusion 60 in the section up to is not arranged on the first direction C1 side and the second direction C2 side with respect to the straight line L d (2) The tip 61 of the protrusion 60 in the entire section from the position D of 20% to the position D of 70% of the proximal tapered portion 22 (2) The position D of 20% of the proximal tapered portion 22 20 from the position D of 70% 70 The tip 61 of the protrusion 60 in the entire section up to is on the first direction C1 side or the second direction C2 side with respect to the straight line L p and is arranged on the first direction C1 side or the second direction C2 side with respect to the straight line L, and the position D of 90% of the proximal tapered portion 22 90 from the position D of 100% 100 The tip 61 of the protrusion 60 in the section up to is not arranged on the first direction C1 side and the second direction C2 side with respect to the straight line L p (2) The tip 61 of the protrusion 60 in the entire section from the position D of 20% to the position D of 70% of the proximal tapered portion 22 The position D from the 90% position D farthest from the straight tube portion 23 of the distal tapered portion 24 and the proximal tapered portion 22 90 to the position D of 100% 100 Since the section up to is the tip side when the balloon 2 is advanced or retracted in the body cavity, in the contracted state of the balloon 2, the tip 61 of at least one protrusion 60 of the distal tapered portion 24 and the proximal tapered portion 22 in this portion is not arranged on the first direction C1 side and the second direction C2 side with respect to the straight line L d or the straight line L p By not being arranged on the first direction C1 side and the second direction C2 side with respect to the straight line L, a straight cut can be made into the body cavity wall at the tip side of the balloon 2. In addition to such a configuration, the position D of at least one of the distal tapered portion 24 and the proximal tapered portion 22 20 from the position D of 20% 70 to the position D of 70% d or the straight line L pSince the balloon 2 is arranged on the first direction C1 side or the second direction C2 side, it is possible to make a straight incision at the tip side of the balloon 2, and then make an incision at an angle by moving the balloon 2 forward or backward, or to incise a wide area in one movement.

[0042] 18 shows an embodiment that satisfies both the above conditions (1) and (2), but it is also possible for either the distal tapered portion 24 or the proximal tapered portion 22 to satisfy the above conditions (1) or (2). From the viewpoint of making straight incisions on both tip ends of the balloon 2, it is preferable that both the distal tapered portion 24 and the proximal tapered portion 22 satisfy the above conditions (1) and (2). This allows for straight incisions to be made on the tip end of the balloon 2 whether the balloon 2 is advanced or retracted.

[0043] As shown in FIG. 19, it is preferable that the balloon 2 according to the embodiment of the present invention, in addition to the above-described aspects, further satisfies at least one of the following (1) and (2). (1) Position D at 40% of the distal tapered portion 24 40 The straight line L of the tip 61 of the protrusion 60 d The distance from the distal tapered portion 24 is 60% of the position D 60 The straight line L of the tip 61 of the protrusion 60 d It is more than 1.2 times the distance from (2) Position D at 40% of the proximal tapered portion 22 40 The straight line L of the tip 61 of the protrusion 60 p The distance from the proximal taper portion 22 is 60% of the position D 60 The straight line L of the tip 61 of the protrusion 60 p It is more than 1.2 times the distance from 40% position D 40 The straight line L of the tip 61 of the protrusion 60 d Or straight line L p The distance from the 60% position D 60 The straight line L of the tip 61 of the protrusion 60 d Or straight line L pIt is preferable that the distance is 1.5 times or more, and more preferable that the distance is 2 times or more. 40 The straight line L of the tip 61 of the protrusion 60 d Or straight line L p The distance from the 60% position D 60 The straight line L of the tip 61 of the protrusion 60 d Or straight line L p The distance is preferably 10 times or less, more preferably 8 times or less, and even more preferably 5 times or less, of the distance from the distal tapered portion 24. d Or straight line L p 20% position D arranged on the first direction C1 side or the second direction C2 side with respect to 20 Position D: 70% from the center 70 This allows for the formation of a more curved portion in the entire section up to the end of the balloon, making it possible to make a more oblique incision while advancing or retracting the balloon 2, or to incise a wider area in one movement.

[0044] As shown in FIG. 20, in the deflated state of the balloon 2, it is preferable that at least one of the following (1) and (2) be satisfied. (1) Position D at 20% of the distal tapered portion 24 20 Position D: 70% from the center 70 The tip 61 of the protrusion 60 in the entire section up to the line L d A virtual curved surface C obtained by rotating the balloon body 20 around the central axis 20C of the balloon body 20 d The slits 24 are disposed inward in the radial direction y of the balloon body 20 or at the same position as the slits 24. (2) Position D at 20% of the proximal tapered portion 22 20 Position D: 70% from the center 70 The tip 61 of the protrusion 60 in the entire section up to the line L p A virtual curved surface C obtained by rotating the balloon body 20 around the central axis 20C of the balloon body 20 p The slits 24 are arranged inward in the radial direction y of the balloon body 20 or at the same position as the slits 24. When the balloon 2 is in a deflated state, the tip 61 of the protruding portion 60 of at least one of the distal tapered portion 24 and the proximal tapered portion 22 is located on the virtual curved surface C d or virtual surface C p Since the balloon 2 is arranged inward in the radial direction y of the balloon body 20 or at the same position as the balloon 2, the diameter of the relevant part can be reduced, and the balloon 2 can be easily inserted when advancing or retreating within the body cavity.

[0045] As shown in Figure 20, the line L d Or straight line L p The straight line L may have an angle in the radial direction y with respect to the central axis 20C of the balloon body 20 (i.e., the longitudinal axis direction x). d Or straight line L p The imaginary curved surface C in the embodiment in which the imaginary curved surface C is angled in the radial direction y with respect to the central axis 20C of the balloon body 20 d and virtual surface C p 20, becomes the side surface of a truncated cone. When the diameter of the balloon 2 is large, or when the length in the radial direction y of the protruding portion 60 at the straight tube portion 23 is longer than the length in the radial direction y of the protruding portion 60 at the distal tapered portion 24 and the proximal tapered portion 22 in the cross section in the radial direction y, the straight line L d Or straight line L p has an angle in the radial direction y with respect to the central axis 20C of the balloon body 20, and the imaginary curved surface C d and virtual surface C p The side of the truncated cone has a bottom surface on the side of straight tube portion 23. In this embodiment, the diameters of the distal and proximal portions of distal tapered portion 24 and proximal tapered portion 22, respectively, can be kept small during deflation, and the diameter of the portion that will be the tip side when balloon 2 is inserted into a body cavity and moved forward or backward becomes small, making it easier to insert balloon 2 into the body cavity.

[0046] Although not shown, the straight line L d Or straight line L p The straight line L may be parallel to the central axis 20C of the balloon body 20 (i.e., the longitudinal axis direction x). d Or straight line L p is parallel to the central axis 20C of the balloon body 20.d and virtual surface C p is the side of the cylinder. Line L d and the line L p is parallel to the central axis 20C of the balloon body 20, the diameter of the straight tube portion 23 can be reduced when the balloon 2 is deflated, and the diameter of the straight tube portion 23 can also be reduced when the blades 29 formed by the deflation of the balloon 2 are wrapped around the shaft 3, making it easier to insert the straight tube portion 23 into the body cavity.

[0047] In FIG. 20, the imaginary curved surface C in the distal tapered portion 24 and the proximal tapered portion 22 d and virtual surface C p In the embodiment, both of the curved surfaces are the side surfaces of a truncated cone. d is the side surface of the cylinder and the imaginary curved surface C in the proximal tapered portion 22 p may be the side of a truncated cone, or vice versa.

[0048] In Figure 20, the 20% position D of both tapers 20 Position D: 70% from the center 70 However, the balloon 2 according to the embodiment of the present invention also includes an embodiment in which either the distal tapered portion 24 or the proximal tapered portion 22 satisfies the above conditions (1) or (2). From the viewpoint of improving the insertability when inserting the balloon 2 into a body cavity and advancing it to a lesion, the distal tapered portion 24 is positioned at 20% of the distal tapered portion 24. 20 Position D: 70% from the center 70 In the entire section up to the point where the tip 61 of the protrusion 60 is on the virtual curved surface C d It is preferable that the distal end of the balloon 2 is disposed inward in the radial direction y of the balloon body 20 or at the same position as the distal end of the balloon 2. This allows the diameter of the distal end of the balloon 2 to be reduced when the balloon 2 is inserted into the body cavity and advanced forward, making it easier to insert the balloon 2 into the body cavity.

[0049] As described above, in the balloon 2 according to the embodiment of the present invention, when the balloon 2 is in a deflated state, the tip end 61 of the protruding portion 60 of at least one of the distal tapered portion 24 and the proximal tapered portion 22 is aligned along the straight line L. d and the line L p 21 , the distal end 61 of the protruding portion 60 of the distal tapered section 24, the straight end 61 of the protruding portion 60 of the proximal tapered section 22, and the proximal end 61 of the protruding portion 60 of the proximal tapered section 22 are preferably positioned at the same position in the circumferential direction z of the balloon body 20. This allows the balloon 2 to be inflated at a lesion or the like after delivery to make a straight incision, but in the deflated state it can be moved forward or backward to make an oblique incision at a stricture or to incise a wide area in a single movement.

[0050] 21, the protruding portions 60 of the distal tapered section 24, the protruding portions 60 of the straight tube section 23, and the protruding portions 60 of the proximal tapered section 22 preferably extend continuously in the longitudinal axis direction x of the balloon body 20. By having the protruding portions 60 extend continuously in the longitudinal axis direction x of the balloon body 20, it is possible to further improve the strength of the balloon 2 and further prevent the balloon 2 from over-expanding when pressurized.

[0051] As shown in FIGS. 3 to 5 and 15 to 17, the balloon body 20 has wing-forming portions 28 that form wings 29 in the deflated state, and the protruding portions 60 are preferably located outside the wing-forming portions 28. If the protruding portions 60 are located outside the wing-forming portions 28, they do not interfere with the folding of the wings 29, making it easier to fold the balloon 2 and reducing the outer diameter of the balloon 2 in the folded state. In a more preferred embodiment, as shown in FIGS. 4 and 5, multiple wings 29 are formed in the deflated state, and the protruding portions 60 are preferably located between the multiple wings 29. This allows the wings 29 to protect the protruding portions 60 when the balloon 2 is folded, as shown in FIGS. 15 and 16. This reduces damage to the protruding portions 60 and prevents the protruding portions 60 from acting on the wall of the body cavity at unintended locations when the balloon 2 is folded and inserted into the body cavity. 16 and 17, by adjusting the length of the vanes 29 in the radial direction y, for example, by adjusting the diameter of the balloon 2 or the number of vanes 29, it is possible to adjust the extent to which the vanes 29 cover the protruding portions 60 in the distal tapered portion 24 and the proximal tapered portion 22. That is, if the vanes 29 are short enough so as not to cover the protruding portions 60 in the distal tapered portion 24 and the proximal tapered portion 22 near the 0% position D0 from the straight tube portion 23, the protruding portions 60 can be exposed from the vanes 29 in most of the distal tapered portion 24 and the proximal tapered portion 22, and the exposed protruding portions 60 can be used to incise the stricture while moving the balloon 2 forward or backward. Alternatively, the wings 29 can be made long enough to cover the protrusions 60 beyond the 50% position of the distal tapered portion 24 and the proximal tapered portion 22. In this case, the portion of the protrusions 60 exposed from the wings 29 can be made smaller, thereby suppressing the effect of the protrusions 60 when advancing or retracting the balloon 2. In this way, by adjusting the range over which the wings 29 cover the protrusions 60, it is possible to accommodate various lesions.

[0052] Although Figures 4, 5, and 15 to 17 show an embodiment with three vanes 29, the number of vanes 29 is not particularly limited as long as the balloon 2 can be folded. For example, two or more vanes are preferred, three or more vanes are more preferred, and four or more vanes, five or more vanes are also preferred. If the lower limit of the number of vanes 29 is within the above range, the diameter of the balloon 2 can be reduced while covering the protruding portion 60 during folding, thereby improving insertion into a body cavity. Furthermore, the number of vanes 29 is preferably ten or less, more preferably eight or less, and even more preferably six or less. If the upper limit of the number of vanes 29 is within the above range, even a balloon 2 with a large diameter can be easily folded. By setting the number of vanes 29 within the above range, the size of the portion of the protruding portion 60 covered by the vanes 29 in the distal tapered portion 24 and the proximal tapered portion 22 can be adjusted.

[0053] Examples of materials for the balloon body 20 include polyolefin resins such as polyethylene, polypropylene, and ethylene-propylene copolymer; polyester resins such as polyethylene terephthalate and polyester elastomer; polyurethane resins such as polyurethane and polyurethane elastomer; polyphenylene sulfide resins; polyamide resins such as polyamide and polyamide elastomer; fluorine-containing resins; silicone resins; and natural rubbers such as latex rubber. These materials may be used alone or in combination. Among these, polyamide resins, polyester resins, and polyurethane resins are preferred. Elastomer resins are particularly preferred for achieving thinness and flexibility in the balloon body 20. Among polyamide resins, nylon 12 and nylon 11 are preferred, with nylon 12 being more preferred due to its ease of blow molding. Furthermore, polyamide elastomers such as polyetheresteramide elastomers and polyamideether elastomers are preferred for achieving thinness and flexibility in the balloon body 20. Among these, polyether ester amide elastomers are preferably used because they have high yield strength and provide good dimensional stability to the balloon body 20 .

[0054] The protrusions 60 are preferably made of the same material as the balloon body 20. If the protrusions 60 are made of the same material as the balloon body 20, the flexibility of the balloon 2 can be maintained while the protrusions 60 are less likely to damage the outer surface of the balloon body 20. The balloon body 20 and the protrusions 60 are preferably molded integrally. This prevents the protrusions 60 from falling off the balloon body 20.

[0055] Examples of materials that can be used to form the shaft 3 include polyamide resins, polyester resins, polyurethane resins, polyolefin resins, fluorine-based resins, vinyl chloride resins, silicone resins, and natural rubber. These materials can be used alone or in combination. Among these, the material that forms the shaft 3 is preferably at least one of polyamide resins, polyolefin resins, and fluorine-based resins. This can increase the slipperiness of the surface of the shaft 3 and improve the insertability of the balloon catheter 1 within a body cavity.

[0056] The balloon 2 and the shaft 3 can be joined by bonding with an adhesive, welding, or by attaching a ring-shaped member to the overlapping portion of the end of the balloon 2 and the shaft 3 and crimping them. Among these, it is preferable that the balloon 2 and the shaft 3 are joined by welding. By welding the balloon 2 and the shaft 3, the bond between the balloon 2 and the shaft 3 is unlikely to come loose even when the balloon 2 is repeatedly inflated and deflated, and the bond strength between the balloon 2 and the shaft 3 can be easily increased.

[0057] As shown in FIG. 1 , the balloon catheter 1 may have a hub 4 provided proximal to the shaft 3. The hub 4 may have a fluid injection section 7 connected to a flow path for fluid supplied to the interior of the balloon 2. The hub 4 preferably has a guidewire insertion section 5 communicating with a guidewire insertion passage. The balloon catheter 1 has a hub 4 equipped with the fluid injection section 7 and the guidewire insertion section 5, which facilitates the operation of supplying fluid to the interior of the balloon 2 to inflate and deflate the balloon 2 and the operation of delivering the balloon catheter 1 to a treatment site along the guidewire. The balloon 2 according to the embodiment of the present invention can be applied not only to so-called over-the-wire balloon catheters in which a guidewire is inserted from the distal end to the proximal end of the shaft 3 as shown in FIG. 1 , but also to so-called rapid exchange balloon catheters in which a guidewire is inserted partway from the distal end to the proximal end of the shaft.

[0058] The shaft 3 and the hub 4 can be joined by, for example, bonding with an adhesive or welding. Of these, it is preferable that the shaft 3 and the hub 4 are joined by adhesive. By bonding the shaft 3 and the hub 4, the bond strength between the shaft 3 and the hub 4 can be increased, thereby improving the durability of the balloon catheter 1, even when the shaft 3 and the hub 4 are made of different materials, such as when the shaft 3 is made of a highly flexible material and the hub 4 is made of a highly rigid material.

[0059] The present invention also provides a method for manufacturing a balloon 2 for a balloon catheter 1 according to an embodiment of the present invention. A method for manufacturing a balloon 2 according to an embodiment of the present invention will be described with reference to FIGS. 22 to 27. FIG. 22 is a perspective view of a parison before expansion according to an embodiment of the present invention, showing the presence of a lumen and a thick-walled portion. FIG. 23 is a radial cross-sectional view of a first cylindrical object or a second cylindrical object in a manufacturing method according to an embodiment of the present invention. FIG. 24 is a radial cross-sectional view of a step of arranging a distal tapered portion in the first cylindrical object or a step of arranging a proximal tapered portion in the second cylindrical object in a manufacturing method according to an embodiment of the present invention, showing a radial cross-sectional view of a position where the proximal end of the distal tapered portion or the distal end of the proximal tapered portion is arranged in the first cylindrical object or the second cylindrical object, respectively. FIG. 25 is a radial cross-sectional view of the first cylindrical object or the second cylindrical object shown in FIG. 24 at another position in the longitudinal axis direction, showing the tip of the protruding portion of the distal tapered portion aligned with a straight line L. d The portion of the balloon body that is disposed on the first direction side in the circumferential direction of the balloon body with respect to the proximal tapered portion is located at a position where the tip of the protruding portion of the proximal tapered portion is aligned with the straight line L p 26 is a radial cross-sectional view of the first cylindrical object or the second cylindrical object shown in FIG. 24 at a different location in the longitudinal axis direction, in which the tip of the protruding portion of the distal tapered portion is aligned with a straight line L. d The portion of the balloon body that is further circumferentially in the first direction relative to the proximal tapered portion is located at a position where the proximal tapered portion is located on the straight line L. p 24 to 26 show radial cross-sectional views of the location where the portion disposed further to the first direction side in the circumferential direction of the balloon body is located. The dashed lines in Figures 24 to 26 show the circumferential positions of the tips of the protrusions at the proximal end of the distal tapered section or the circumferential positions of the tips of the protrusions at the distal end of the proximal tapered section, and these are indicated by the straight line L d or L p 27 is a cross-sectional view in the radial direction of a third cylindrical object in a manufacturing method according to an embodiment of the present invention.

[0060] A method for manufacturing a balloon 2 according to an embodiment of the present invention includes the steps of preparing a first cylindrical body 310, a second cylindrical body 320, and a third cylindrical body 330, each having a space therein extending in the longitudinal axis direction, and manufacturing a balloon for a balloon catheter having a balloon body 20 having an outer surface and an inner surface, the balloon body 20 having a straight tube portion 23, a distal tapered portion 24 located distal to the straight tube portion 23, and a proximal tapered portion 22 located proximal to the straight tube portion 23, and the distal tapered portion 24 and the straight tube portion 23 are connected to each other. The method includes a step of preparing a balloon for a balloon catheter, the balloon having a protruding portion 60 in which the distal tapered portion 24 and the proximal tapered portion 22 protrude radially outward from the outer surface of the balloon body 20 in the radial direction y and extend in the longitudinal axis direction x of the balloon body 20; and an arrangement step of arranging the distal tapered portion 24 in the first cylindrical body 310, the proximal tapered portion 22 in the second cylindrical body 320, and the straight tube portion 23 in the third cylindrical body 330 when the balloon is in a deflated state, and satisfies at least one of the following (1) and (2). (1) In the disposing step, the inner surface of the first cylindrical object 310 and at least a part of the protruding portion 60 of the distal tapered portion 24 are in contact with each other. (2) In the disposing step, the inner surface of the second cylindrical object 320 and at least a part of the protruding portion 60 of the proximal tapered portion 22 are in contact with each other. By arranging the protrusion 60 of the distal tapered section 24 so that at least a portion of the protrusion 60 abuts against the inner surface of the first cylindrical object 310, the protrusion 60 can be moved in the circumferential direction z of the balloon body 20. As a result, the tip 61 of the protrusion 60 of the distal tapered section 24 can be arranged to curve toward the first direction C1 or the second direction C2 in the circumferential direction z of the balloon body 20 in the deflated state. Furthermore, by arranging the protruding portion 60 of the proximal tapered portion 22 so that at least a portion of the protruding portion 60 abuts against the inner surface of the second cylindrical object 320, the protruding portion 60 can be moved in the circumferential direction z of the balloon body 20. As a result, the tip 61 of the protruding portion 60 of the proximal tapered portion 22 can be arranged to curve in the first direction C1 or the second direction C2 in the circumferential direction z of the balloon body 20 in the deflated state.

[0061] In order to move the tip 61 of the protrusion 60 of the distal taper portion 24 in the circumferential direction z of the balloon body 20 in the contracted state, it is sufficient to carry out the above-mentioned step (1). In order to move the tip 61 of the protrusion 60 of the proximal taper portion 22 in the circumferential direction z of the balloon body 20 in the contracted state, it is sufficient to carry out the above-mentioned step (2). In order to move the tip 61 of the protrusions 60 of both the distal taper portion 24 and the proximal taper portion 22 in the circumferential direction z of the balloon body 20 in the contracted state, it is sufficient to carry out both the above-mentioned steps (1) and (2).

[0062] In the balloon preparation process, a cylindrical parison 200 made of resin, as shown in FIG. 22 , is placed in a mold having a groove in its inner cavity, and the balloon is prepared by biaxially stretching and blow molding. The protrusion 60 can be formed, for example, by inserting the parison 200 into the mold cavity, fitting the thick-walled portion 220 of the parison 200 into the mold groove, and then introducing a fluid into the inner cavity 210 of the parison 200 to expand the parison 200. Furthermore, when the distal sleeve portion 25 or the proximal sleeve portion 21 does not have a protrusion 60 or when an inward protrusion is to be formed, the balloon 2 can be manufactured by, for example, pressing the thick-walled portion 220 of the parison 200 against a portion of the mold without a groove, and then introducing a fluid into the inner cavity 210 of the parison 200 to expand the parison 200. For the material constituting the parison 200, the description of the material constituting the balloon body 20 above can be referenced.

[0063] When performing step (1) of the manufacturing method according to one embodiment of the present invention, the first cylindrical object 310 has an internal space extending in the longitudinal axis direction x, as shown in Figure 23 , and the shape of this space in a cross section in the radial direction y preferably varies along the longitudinal axis direction x. That is, the shape of the space preferably varies depending on the distance traveled when the tip 61 of the protrusion 60 of the distal taper section 24 is moved in the circumferential direction z of the balloon body 20 in the deflated state. This makes it possible to change the position at which at least a portion of the protrusion 60 of the distal taper section 24 abuts against the inner surface of the first cylindrical object 310, thereby preventing the tip 61 of the protrusion 60 of the distal taper section 24 from moving in the radial direction y of the balloon body 20 in the deflated state and adjusting the distance traveled in the circumferential direction z of the balloon body 20.

[0064] An example of the shape of the space portion of the first cylindrical object 310 in a cross section in the radial direction y will be described. d The space in the first cylindrical object 310 where the tip end 61 of the protrusion 60 of the distal tapered portion 24 at the base end and tip end of the first cylindrical object 310 is disposed preferably has a space shape that does not abut the protrusion 60, and for example, the space in the first cylindrical object 310 where the proximal end of the distal tapered portion 24 is disposed may have a shape as shown in Figure 24. When it is desired to suppress movement of the tip end 61 of the protrusion 60 of the distal tapered portion 24 in the radial direction y of the balloon body 20, the tip end 61 of the protrusion 60 of the distal tapered portion 24 is aligned with the straight line L. d The space of the first cylindrical object 310 at the location where the portion of the balloon body 20 arranged on the first direction C1 side in the circumferential direction z is disposed preferably has a space shaped so that at least a portion of the space abuts the protrusion 60 as shown in Figure 25. dThe space in the first cylindrical object 310 at the location where the portion disposed further circumferentially in the first direction C1 is located preferably has a shape such that at least a portion of the space abuts the protrusion 60, as shown in Fig. 26. In this way, by changing the shape of the space as shown in the examples of Figs. 24 to 26, it is possible to adjust the distance that the tip 61 of the protrusion 60 of the distal tapered section 24 moves in the circumferential direction z of the balloon body 20 while preventing the tip 61 from moving in the radial direction y of the balloon body 20 in the deflated state. Alternatively, although not shown, by adjusting the cross-sectional shape of the space in the radial direction y of the first cylindrical object 310, it is possible to abut at least a portion of the protrusion 60 against the inner surface of the first cylindrical object 310 while allowing the tip 61 of the protrusion 60 to move in the circumferential direction z of the balloon body 20 while allowing the tip 61 of the protrusion 60 to move in the radial direction y of the balloon body 20, thereby adjusting the movement distance in the circumferential direction z along the longitudinal axis direction x. The shape of the space in the first cylindrical object 310 is not limited to the shapes shown in Figures 24 to 26 and may be any shape as long as it is possible to adjust the movement distance in the circumferential direction z of the balloon body 20 while suppressing or allowing the tip 61 of the protrusion 60 of the distal tapered portion 24 to move in the radial direction y of the balloon body 20 in the deflated state.

[0065] It is preferable that the cross-sectional shapes of the first cylindrical body 310 and the second cylindrical body 320 in the radial direction y change continuously in the longitudinal axis direction x, so that the tip end 61 of the protrusion 60 of the distal tapered section 24 and the tip end 61 of the protrusion 60 of the proximal tapered section 22 can be moved continuously in the circumferential direction z of the balloon body 20 in the longitudinal axis direction x in the deflated state.

[0066] The third cylindrical object 330 has a space therein extending in the longitudinal axis direction x. The shape of the space in the third cylindrical object 330 in a cross section in the radial direction y may be the same as or different from the shape of the space in the first cylindrical object 310 at the location where the proximal end of the distal tapered portion 24 is disposed, as shown in FIG. 27 . However, it is preferable that the area of ​​the space in the third cylindrical object 330 in the cross section in the radial direction y be larger than the area of ​​the space in the first cylindrical object 310. This prevents the protruding portion 60 of the straight pipe portion 23 disposed in the space in the third cylindrical object 330 from abutting against the inner surface of the third cylindrical object 330, thereby preventing the inner surface of the third cylindrical object 330 from interfering with the protruding portion 60 of the straight pipe portion 23.

[0067] When step (2) is performed in addition to step (1), the second cylindrical object 320 preferably has the same configuration as the first cylindrical object 310. That is, the shape of the space in the cross section of the second cylindrical object 320 in the radial direction y at the location where the distal end of the proximal tapered portion 22 is disposed may be the shape shown in Figure 24, and the tip end 61 of the protruding portion 60 of the proximal tapered portion 22 may be the shape shown in Figure 24. d The shape of the space of the second cylindrical member 320 at the location where the portion disposed on the first direction C1 side in the circumferential direction is disposed may be the shape shown in FIG. 25, and the tip end 61 of the protruding portion 60 of the proximal tapered portion 22 may be the shape shown in FIG. d The shape of the space in the second cylindrical object 320 at the location where the portion disposed further circumferentially toward the first direction C1 is located may be the shape shown in Figure 26. As with the first cylindrical object 310, the shape of the space in the cross section of the second cylindrical object 320 in the radial direction y is not limited to this. With the second cylindrical object 320 having the above configuration, it is possible to change the position at which the inner surface of the second cylindrical object 320 abuts on at least a portion of the protruding portion 60 of the proximal taper section 22, and to adjust the distance by which the tip portion 61 of the protruding portion 60 of the proximal taper section 22 moves in the circumferential direction z of the balloon body 20 while suppressing or allowing movement in the radial direction y of the balloon body 20 in the deflated state.

[0068] When only the above step (1) is performed without performing the step (2), it is preferable that the second cylindrical object 320 has the same configuration as the above third cylindrical object 330. This makes it possible to prevent the protruding portion 60 of the proximal tapered portion 22 arranged in the space of the second cylindrical object 320 from contacting the inner surface of the second cylindrical object 320, and to prevent the inner surface of the second cylindrical object 320 from interfering with the protruding portion 60 of the proximal tapered portion 22.

[0069] When only the above step (2) is performed without performing the step (1), it is preferable that the first cylindrical object 310 has the same configuration as the above third cylindrical object 330. This makes it possible to prevent the protruding portion 60 of the distal tapered portion 24 arranged in the space of the first cylindrical object 310 from abutting against the inner surface of the first cylindrical object 310, and to prevent the inner surface of the first cylindrical object 310 from interfering with the protruding portion 60 of the distal tapered portion 24.

[0070] It is preferable that the length in the longitudinal direction x of the first cylindrical body 310, the length in the longitudinal direction x of the second cylindrical body 320, and the length in the longitudinal direction x of the third cylindrical body 330 are approximately the same as the length in the longitudinal direction x of the distal tapered portion 24, the length in the longitudinal direction x of the proximal tapered portion 22, and the length in the longitudinal direction x of the straight tube portion 23, respectively.

[0071] In the above-mentioned arrangement step, it is preferable to arrange the first cylindrical body 310, the third cylindrical body 330, and the second cylindrical body 320 in this order in the longitudinal axis direction x so that the centers of the spaces in the cross sections of the first cylindrical body 310, the third cylindrical body 330, and the second cylindrical body 320 coincide with each other, and then insert the balloon 2 into the space from the side of the second cylindrical body 320. This allows the distal tapered section 24 to be arranged in the first cylindrical body 310, the straight tube section 23 to be arranged in the third cylindrical body 330, and the proximal tapered section 22 to be arranged in the second cylindrical body 320.

[0072] By performing the above-described positioning step to determine the position of the tip 61 of the protrusion 60, the position of the tip 61 of the protrusion 60 in the distal tapered section 24 and / or the proximal tapered section 22 can be formed. The balloon 2 can then be folded by hand or using a folding machine or the like. If the protrusion 60 is positioned somewhere other than the wing-forming section 28, it is preferable to fold the balloon 2 so that the wings 29 cover the protrusion 60. By folding the balloon 2 without disrupting the formed position of the tip 61 of the protrusion 60, it is possible to obtain a balloon 2 in which the tip 61 of the protrusion 60 is curved in the circumferential direction z of the balloon body 20 in the folded state.

[0073] Materials that constitute the first cylindrical object 310, the second cylindrical object 320, and the third cylindrical object 330 include, for example, synthetic resins such as polycarbonate-based resins, polyacetal-based resins, and fluorine-based resins, and metals such as iron, copper, and stainless steel.

[0074] This application claims the benefit of priority to Japanese Patent Application No. 2020-215754, filed on December 24, 2020. The entire content of the specification of Japanese Patent Application No. 2020-215754, filed on December 24, 2020, is incorporated herein by reference. [Explanation of symbols]

[0075] 1: Balloon catheter 2: Balloon 3: Shaft 4: Hub 5: Guidewire insertion section 7:Fluid injection part 20: Balloon body 20C: Central axis of the balloon body 21: Proximal sleeve part 22: Proximal tapered section 23: Straight pipe section 24: Distal tapered section 25: Distal sleeve 28: Blade forming section 29: Feather 31: Outer tube 32: Inner tube 60:Protrusion 61:Tip 200:Parison 210: Lumen of parison 220: Thick part of parison 310: First cylindrical object 320: Second cylindrical object 330: Third cylindrical object L d :The tip of the distal tapered section D0 and D 100 A straight line connecting the tip of L p :The tip of the proximal tapered section D0 and D 100 A straight line connecting the tip of C1: 1st direction C2:Second direction D0: 0% position D 20 :20% position D 40 :40% position D 60 :60% position D 70 :70% position D 90 :90% position D 100 :100% position C d :L d A virtual curved surface obtained by rotating around the central axis of the balloon body C p :L p A virtual curved surface obtained by rotating around the central axis of the balloon body x: longitudinal axis direction y: radial direction z: Circumferential direction

Claims

1. A balloon for a balloon catheter having a balloon body with an outer surface and an inner surface, the balloon body has a straight tube portion, a distal tapered portion located distal to the straight tube portion, and a proximal tapered portion located proximal to the straight tube portion; the distal tapered section, the straight tube section, and the proximal tapered section each have a protruding portion that protrudes radially outward from the outer surface of the balloon body and extends in the longitudinal axis direction of the balloon body; the protrusion has a tip end in a cross section of the balloon body in a radial direction, When the balloon for a balloon catheter is in an inflated state, the tip end of the protrusion of the distal tapered portion is not located on the first direction side or the second direction side in the circumferential direction of the balloon body with respect to a straight line Ld connecting the tip end of the proximal end of the distal tapered portion and the tip end of the distal end of the distal tapered portion, and the tip end of the protrusion of the proximal tapered portion is not located on the first direction side or the second direction side in the circumferential direction of the balloon body with respect to a straight line Lp connecting the tip end of the distal end of the proximal tapered portion and the tip end of the proximal end of the proximal tapered portion, A balloon for a balloon catheter that satisfies at least one of the following (1) and (2): (1) When the balloon for the balloon catheter is in a deflated state, the tip end of the protrusion of the distal tapered portion is aligned with the straight line L ｄ With respect to the first direction, the second direction is arranged on the first side and not on the second side, or the second direction is arranged on the second side and not on the first side. (2) When the balloon for the balloon catheter is in a deflated state, the tip end of the protruding portion of the proximal tapered portion is aligned with the straight line L ｐ With respect to the first direction, the second direction is arranged on the first side and not on the second side, or the second direction is arranged on the second side and not on the first side.

2. 2. The balloon for a balloon catheter according to claim 1, wherein the balloon for a balloon catheter is folded in a deflated state.

3. 3. The balloon for a balloon catheter according to claim 1, wherein, in a deflated state of the balloon for a balloon catheter, when the ends of the distal tapered section and the proximal tapered section on the straight tube section side in the longitudinal axis direction of the balloon body are defined as a 0% position and the other ends are defined as a 100% position, at least one of the following (1) and (2) is satisfied: (1) The tip of the protrusion in the entire section from the 20% position to the 70% position of the distal tapered portion is aligned with the straight line L ｄ and the tip of the protrusion in the section from the 90% position to the 100% position of the distal tapered portion is aligned with the straight line L. ｄ are not arranged on the first direction side or the second direction side with respect to the (2) The tip of the protrusion in the entire section from the 20% position to the 70% position of the proximal tapered portion is aligned with the straight line L ｐ and the tip of the protruding portion in the section from the 90% position to the 100% position of the proximal tapered portion is aligned with the straight line L ｐ are not arranged on the first direction side or the second direction side with respect to the

4. The balloon for a balloon catheter according to claim 3, which satisfies at least one of the following (1) and (2): (1) The straight line L of the tip of the protrusion at a position 40% of the distal tapered portion ｄ The distance from the straight line L of the tip of the protrusion at a position 60% of the distal tapered portion is ｄ It is more than 1.2 times the distance from (2) The straight line L of the tip of the protrusion at a position 40% of the proximal taper portion ｐ The distance from the straight line L of the tip of the protrusion at a position 60% of the proximal taper portion ｐ It is more than 1.2 times the distance from

5. The balloon for a balloon catheter according to any one of claims 1 to 4, wherein, in a deflated state, the balloon for a balloon catheter satisfies at least one of the following (1) and (2): (1) The tip of the protrusion in the entire section from the 20% position to the 70% position of the distal tapered portion is aligned with the straight line L ｄ The balloon body is disposed radially inward of or at the same position as an imaginary curved surface obtained by rotating the balloon body around the central axis of the balloon body. (2) The tip of the protrusion in the entire section from the 20% position to the 70% position of the proximal tapered portion is aligned with the straight line L ｐ The balloon body is disposed radially inward of or at the same position as an imaginary curved surface obtained by rotating the balloon body around the central axis of the balloon body.

6. 6. The balloon for a balloon catheter according to claim 1, wherein, in an expanded state of the balloon for a balloon catheter, the tip of the protruding portion of the distal tapered section, the tip of the protruding portion of the straight tube section, and the tip of the protruding portion of the proximal tapered section are located at the same circumferential position of the balloon body.

7. 7. The balloon for a balloon catheter according to claim 1, wherein the balloon body has wing forming portions that form wings in a deflated state, and the protrusions are located outside the wing forming portions.

8. 8. The balloon for a balloon catheter according to claim 1, wherein the protruding portion of the distal tapered section, the protruding portion of the straight tube section, and the protruding portion of the proximal tapered section extend continuously in the longitudinal axis direction of the balloon body.

9. The balloon for a balloon catheter according to any one of claims 1 to 8, wherein the protrusions are made of the same material as the balloon body.

10. A method for manufacturing a balloon for a balloon catheter according to any one of claims 1 to 9, comprising: preparing a first cylindrical object, a second cylindrical object, and a third cylindrical object each having a space therein extending in a longitudinal axis direction; preparing a balloon for a balloon catheter, the balloon having a balloon body having an outer surface and an inner surface, the balloon body having a straight tube portion, a distal tapered portion located distal to the straight tube portion, and a proximal tapered portion located proximal to the straight tube portion, the distal tapered portion, the straight tube portion, and the proximal tapered portion having protrusions that protrude radially outward beyond the outer surface of the balloon body and extend in the longitudinal axis direction of the balloon body; and an arrangement step of arranging the distal tapered portion within the first cylindrical body, the proximal tapered portion within the second cylindrical body, and the straight tube portion within the third cylindrical body when the balloon for the balloon catheter is in a deflated state, A method for manufacturing a balloon for a balloon catheter, which satisfies at least one of the following (1) and (2): (1) In the positioning step, the inner surface of the first cylindrical object and at least a part of the protruding portion of the distal tapered portion are in contact with each other. (2) In the positioning step, the inner surface of the second cylindrical object and at least a part of the protruding portion of the proximal tapered portion are in contact with each other.

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