Balloon for balloon catheter

Abstract

Provided is a balloon for a balloon catheter that can incise a constricted portion in the contracted state.　The balloon for a balloon catheter has a balloon body (20) and a protruding portion (60) that has a tip end portion (61), and satisfies (1) and / or (2) below.　(1) The tip end portion (61) from D20 to D50 of a distal-side tapered portion (24) is arranged outward in the radial direction y with respect to a virtual curved surface Cd that is obtained by rotating around the central axis (20C) a straight line Ld connecting the tip end portion (61) of D0 and the tip end portion (61) of D100.　(2) The tip end portion (61) from D20 to D50 of a proximal-side tapered portion (22) is arranged outward in the radial direction y with respect to a virtual curved surface Cp that is obtained by rotating around the central axis (20C) a straight line Lp connecting the tip end portion (61) of D0 and the tip end portion (61) of D100.

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 a 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 facilitate insertion into body cavities and prevent an increase in the outer diameter. However, because the height of the scoring element at the distal end of such balloon catheters is reduced, it is difficult to incise a stricture while the balloon is deflated during delivery or at the lesion. 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, this is insufficient in terms of ensuring insertional ease when the balloon is deflated and incising a stricture while advancing or retracting the balloon.

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

[0008] One embodiment of the balloon for a balloon catheter of the present invention that has solved the above-mentioned problems is a balloon for a balloon catheter having a balloon body with 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 each having 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 protruding portion having a tip portion in a radial cross section of the balloon body, and when the straight tube section-side ends of the distal tapered section and the proximal tapered section in the longitudinal axis direction of the balloon body are defined as the 0% position and the other end is defined as the 100% position in the deflated state of the balloon for a balloon catheter, at least one of the following (1) and (2) is satisfied: (1) The tip of the protrusion in the section from the 20% position to the 50% position of the distal taper portion is a straight line L connecting the tip of the distal taper portion at the 0% position and the tip of the distal taper portion at the 100% position. d The balloon body is disposed radially outward of the 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 section from the 20% position to the 50% position of the proximal taper is aligned with the straight line L connecting the tip of the proximal taper at the 0% position and the tip of the proximal taper at the 100% position. p The balloon body is disposed radially outward of the imaginary curved surface obtained by rotating the balloon body around the central axis of the balloon body.

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

[0010] 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 section from the 90% position to the 100% position of the distal tapered section is a straight line L dThe 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 section from the 90% position to the 100% 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.

[0011] When the balloon for a balloon catheter is in an expanded state, it is preferable that the protruding portion of the distal tapered portion, the protruding portion of the straight tube portion, and the protruding portion of the proximal tapered portion are arranged at the same circumferential position of the balloon body.

[0012] When the balloon for a balloon catheter is in a deflated state, it is preferable that the protruding portions of the straight tube section, the protruding portions of the distal tapered section, and the protruding portions of the proximal tapered section are arranged 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 manufacturing the above-described balloon for a balloon catheter. The manufacturing method according to one embodiment of the present invention includes the steps of preparing a first cylindrical object and a second cylindrical object, each having a space extending in the longitudinal direction and having a pressing member on its inner surface that can protrude and retract from the outside to the inside, and a third cylindrical object having a space extending in the longitudinal direction therein; and preparing a balloon for a balloon catheter having a balloon body with 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 method includes the steps of: preparing a balloon for a balloon catheter, in which the distal tapered portion, straight tube portion, and proximal tapered portion protrude radially outward from the outer surface of the balloon body and have protrusions extending in the longitudinal axis direction of the balloon body; arranging the distal tapered portion in a first cylindrical object, arranging the proximal tapered portion in a second cylindrical object, and arranging the straight tube portion in a third cylindrical object; and deflating the balloon for a balloon catheter, and includes at least one of the steps (1) and (2) below. (1) In the contraction step, the pressing member of the first cylindrical object presses both sides of the protrusion in a cross section perpendicular to the longitudinal axis direction of the balloon body toward the inside of the first cylindrical object. (2) In the contraction step, the pressing member of the second cylindrical object presses both sides of the protrusion in a cross section perpendicular to the longitudinal axis direction of the balloon body toward the inside of the second cylindrical object. [Effects of the Invention]

[0017] According to the balloon for balloon catheter described above, when the balloon is in a deflated state, the tip of the protruding portion of at least one of the distal tapered portion and the proximal tapered portion is positioned radially outward of the balloon so as to satisfy predetermined conditions. 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 incise the stenotic portion. [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 shows a partial longitudinal cross-sectional view of the balloon shown in FIG. 2 in a deflated state. [Figure 7] 10 is a partial longitudinal cross-sectional view of a balloon according to another embodiment of the present invention in a deflated state. FIG. [Figure 8] 3 shows a side view of the balloon shown in FIG. 2 in a folded state. [Figure 9] 9 shows a cross-sectional view taken along line IX-IX in FIG. 8. [Figure 10] XX cross-sectional view of FIG. 8. [Figure 11] 10 shows a cross-sectional view taken along the line XI-XI in FIG. 8. [Figure 12] 10A and 10B show partial longitudinal cross-sectional views of a balloon in a deflated state according to yet another embodiment of the present invention. [Figure 13] 3 shows a plan view of the balloon shown in FIG. 2 as seen from the protruding portion side. [Figure 14] FIG. 2 illustrates a perspective view of a parison prior to expansion according to one embodiment of the present invention. [Figure 15] 2 is a cross-sectional view perpendicular to the longitudinal axis direction of a first cylindrical object in a manufacturing method according to one embodiment of the present invention. FIG. [Figure 16] 3 is a cross-sectional view perpendicular to the longitudinal axis direction of a second cylindrical object in a manufacturing method according to one embodiment of the present invention. [Figure 17] 4 is a cross-sectional view perpendicular to the longitudinal axis direction of a third cylindrical object in a manufacturing method according to one embodiment of the present invention. FIG. [Figure 18]10 is a cross-sectional view perpendicular to the longitudinal axis direction during the step of arranging the distal tapered portion inside the first cylindrical object in the manufacturing method according to one embodiment of the present invention. FIG. [Figure 19] 10A and 10B are cross-sectional views perpendicular to the longitudinal axis direction in a step in which a pressing member presses both side portions of a protrusion in a manufacturing method according to an embodiment of the present invention. 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 an embodiment of the present invention has a balloon body having an outer surface and an inner surface. 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. The distal tapered section, straight tube section, and 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 protruding portion has a tip portion in a radial cross section of the balloon body. When the straight tube section-side ends of the distal tapered section and the proximal tapered section in the longitudinal axis direction of the balloon body are defined as 0% and 100%, respectively, in the deflated state of the balloon for a balloon catheter, at least one of the following (1) and (2) is satisfied: (1) The tip of the protrusion in the section from the 20% position to the 50% position of the distal taper portion is a straight line L connecting the tip of the distal taper portion at the 0% position and the tip of the distal taper portion at the 100% position. dThe balloon body is disposed radially outward of the 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 section from the 20% position to the 50% position of the proximal taper is aligned with the straight line L connecting the tip of the proximal taper at the 0% position and the tip of the proximal taper at the 100% position. p The balloon body is disposed radially outward of the imaginary curved surface obtained by rotating the balloon body around the central axis of the balloon body. In this way, when the balloon is in a deflated state, the tip of the protruding portion of at least one of the distal tapered portion and the proximal tapered portion is disposed radially outward from the balloon body so as to satisfy the above-mentioned predetermined condition, so that during delivery of the balloon or when the balloon has been delivered to the lesion, the stenotic portion can be incised by moving the balloon forward or backward in the deflated state. 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 13. 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 partial longitudinal cross-sectional view of the balloon shown in Figure 2 in a contracted state, i.e., a cross-sectional view of the balloon membrane including the balloon body and protrusions, and Figure 7 shows a cross-sectional view of a modified version of Figure 6. Figure 8 shows a side view of the balloon shown in Figure 2 in a folded state, and Figures 9, 10, and 11 show cross-sectional views taken along lines IX-IX, XX, and XI-XI of the balloon shown in Figure 8, respectively. Fig. 12 is a partial longitudinal cross-sectional view of a balloon according to another embodiment of the present invention in a deflated state, i.e., a cross-sectional view of the balloon membrane including the balloon body and protrusions. Fig. 13 is a plan view of the balloon shown in Fig. 2, seen from the protrusion 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 FIGS. 1 to 7 , the balloon 2 for the balloon catheter 1 has a balloon body 20 having an outer surface and an inner surface, and 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 each have a protruding portion 60 that protrudes outward in the radial direction y from the outer surface of the balloon body 20 and extends 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. When the balloon 2 is in a deflated state, the ends of the distal tapered section 24 and the proximal tapered section 22 on the straight tube section 23 side in the longitudinal axis direction x of the balloon body 20 are designated as a 0% position D0, and the other ends are designated as a 100% position D1. 100 When this is the case, at least one of the following (1) and (2) is satisfied. (1) Position D at 20% of the distal tapered portion 24 20 Position D: 50% from the center 50 The tip 61 of the protrusion 60 in the section up to is the tip 61 at the 0% position D0 of the distal tapered portion 24 and the 100% position D 100 A straight line L connecting the tip 61 of d A virtual curved surface C obtained by rotating the balloon body 20 around the central axis 20C of the balloon body 20 d 3. The stator 22 is disposed outward in the radial direction y of the balloon body 20. (2) Position D at 20% of the proximal tapered portion 22 20 Position D: 50% from the center 50 The tip 61 of the protruding portion 60 in the section up to is the tip 61 at the 0% position D0 of the proximal tapered portion 22 and the 100% position D 100 A straight line L connecting the tip 61 of p A virtual curved surface C obtained by rotating the balloon body 20 around the central axis 20C of the balloon body 20 p 3. The stator 22 is disposed outward in the radial direction y of the balloon body 20. 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 radially outward of the balloon body 20 so as to satisfy the above-mentioned specified conditions. Therefore, during delivery of the balloon 2 or when the balloon 2 is delivered to the lesion site, the balloon 2 can be advanced or retracted in the deflated state to incise the stenotic site using the tip 61.

[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 in an inflated state. 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 a cross section along the y direction 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. Such protrusions 60 facilitate incision of the stricture, improve the strength of the balloon 2, and prevent over-expansion of the balloon 2 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 and 7, 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 distance is 20% of the distal tapered portion 24,20 Position D: 50% from the center 50 and the position D at 20% of the proximal taper portion 22 20 Position D: 50% from the center 50 The tip 61 of the protrusion 60 in at least one of the sections from d A virtual curved surface C obtained by rotating the balloon body 20 around the central axis 20C of the balloon body 20 d and the line L p A virtual curved surface C obtained by rotating the balloon body around the central axis 20C pThe distal end 61 of the protrusions 60 of the distal tapered section 24 and the proximal tapered section 22 is disposed outward in the radial direction y of the balloon body 20 relative to the distal end 61 of the protrusions 60 of the proximal tapered section 22. That is, when the balloon 2 is deflated, the tips 61 of the protrusions 60 of both the distal tapered section 24 and the proximal tapered section 22 may be disposed outward in the radial direction y of the balloon body 20 so as to satisfy the above-mentioned predetermined condition, or the tips 61 of the protrusions 60 of either tapered section may be disposed outward in the radial direction y of the balloon body 20 so as to satisfy the above-mentioned predetermined condition. If the tips 61 of the protrusions 60 of both tapered sections are disposed outward in the radial direction y of the balloon body 20 so as to satisfy the above-mentioned predetermined condition, the tips 61 can be used to act on the stenotic site and make an incision, regardless of whether the balloon 2 is advanced or retreated within the body cavity in the deflated state. Furthermore, for example, if the tip 61 of the protrusion 60 in only the proximal tapered portion 22 is arranged radially outward of the balloon body 20 in the y direction so as to satisfy the above-mentioned specified conditions, and the tip 61 of the protrusion 60 in the distal tapered portion 24 is not arranged radially outward of the balloon 20 in the y direction, the diameter of the distal tapered portion 24, which passes through the body cavity first when the balloon 20 is advanced, can be reduced, and the balloon 2 can be deflated to easily pass through the body cavity while the tip 61 of the protrusion 60 of the proximal tapered portion 22 can be used to incise the stenotic portion. Conversely, if the tip 61 of the protrusion 60 in only the distal tapered portion 24 is disposed outward in the radial direction y of the balloon body 20 so as to satisfy the above-mentioned predetermined condition, and the tip 61 of the protrusion 60 in the proximal tapered portion 22 is not disposed outward in the radial direction y of the balloon 20, then the distal tapered portion 24, which passes through the body cavity first when the balloon 20 is advanced, can incise the stricture, improving the subsequent insertability of the balloon 2. Furthermore, the balloon 20 can easily pass through the body cavity when retracted.

[0033] Figure 5 shows a tapered portion in which the tips 61 of the protrusions 60 are disposed radially outward of the balloon body 20 in the y direction so as to satisfy a predetermined condition. As shown in Figure 5, in a tapered portion in which the tips 61 of the protrusions 60 are disposed radially outward of the balloon body 20 in the y direction so as to satisfy a predetermined condition, the inner surface of the balloon body 20 where the protrusions 60 are formed is raised above the shaft 3 (inner tube 32), and the rest of the balloon body 20 other than the protrusions 60 and the vanes 29 may be in close proximity to the shaft 3 (inner tube 32). This allows the tips 61 of the protrusions 60 in the tapered portion to be disposed radially outward of the balloon body 20 in the y direction, while reducing the outer diameter of the rest of the balloon 2 other than the protrusions 60 and the vanes 29. This reduces the outer diameter of the balloon 2 when folded, even though the tips 61 of the protrusions 60 in the tapered portion are disposed radially outward in the y direction, thereby enabling the balloon 2 to be easily inserted into a body cavity.

[0034] In at least one of the distal tapered portion 24 and the proximal tapered portion 22, the tip 61 of the protrusion 60 is at a 20% position D 20 Position D: 50% from the center 50 In the other sections, the tip 61 of the protrusion 60 may be disposed outward in the radial direction y of the balloon body 20, may be disposed at the same position in the radial direction y of the balloon body 20, or may be disposed inward in the radial direction y of the balloon body 20. In at least one of the distal tapered section 24 and the proximal tapered section 22, the tip 61 of the protrusion 60 is more preferably disposed outward in the radial direction y of the balloon body 20 in the section from the 15% position to the 60% position, and even more preferably in the section from the 10% position to the 70% position. Also, for example, the tip 61 of the protrusion 60 may be disposed outward in the radial direction y of the balloon body 20 in the section from the 0% position D0 to the 100% position D 100 (However, the 0% position D0 and the 100% position D 100 ) may be arranged outside the balloon body 20 in the radial direction y.

[0035] The amount by which the tip 61 of the protrusion 60 protrudes in the radial direction y of the balloon body 20 can be adjusted by the amount by which the inner surface of the balloon body 20 where the protrusion 60 is formed floats above the shaft 3 (inner tube 32), or by the radial length of the protrusion 60 in the radial y cross section. However, from the viewpoint of the insertability of the balloon 2 in its inflated state, it is preferable to adjust the amount by which the tip 61 protrudes in the radial direction y by the amount by which the inner surface of the balloon body 20 where the protrusion 60 is formed floats above the shaft 3. This allows the tip 61 of the protrusion 60 to be positioned outward in the radial direction y without increasing the radial length of the protrusion 60 in the radial y cross section of the tapered portion. With this configuration, the balloon 2 can be advanced or retracted within the body cavity, and the tip 61 of the protrusion 60 positioned outward in the radial direction y can incise the stenotic site. At the same time, since the inner surface of the balloon body 20 where the protrusion 60 is formed is floating from the shaft 3, there is room for the protrusion 60 to move inward in the radial direction y when the balloon 2 passes through a narrowed or bent section, and the outer diameter of the balloon 2 can be reduced, thereby preventing the balloon 2 from getting caught in a narrowed or bent section and improving insertability.

[0036] By adjusting the section in the longitudinal axis direction x in which the tip 61 of the protrusion 60 is positioned outward in the radial direction y, and the amount of protrusion of the tip 61 of the protrusion 60 in the radial direction y of the balloon body 20, it is possible to apply the balloon 2 to treatment sites in various conditions.

[0037] With regard to the radial y length of the protrusion 60 in a cross section in the radial y direction, the length of the protrusion 60 in the distal tapered section 24 or the proximal tapered section 22 is preferably shorter than the length of the protrusion 60 in the straight tube section 23. Even if the radial y length of the protrusion 60 in the tapered section is shorter than the radial y length of the protrusion 60 in the straight tube section 23, the tip 61 of the protrusion 60 in the tapered section can be positioned outward in the radial y direction by floating the inner surface of the balloon body 20 where the protrusion 60 is formed above the shaft 3 (inner tube 32) as described above.

[0038] In the expanded state, the distal tapered portion 24 and the proximal tapered portion 22 have tips 61 of the protrusions 60 that are aligned along a straight line L d and L p This 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.

[0039] As shown in FIG. 6, the tip 61 at the 0% position D0 of the distal tapered portion 24 and the tip 61 at the 100% position D 100 A straight line L connecting the tip 61 of d、 and the distal end 61 at the 0% position D0 of the proximal tapered portion 22 and the 100% position D 100 A straight line L connecting the tip 61 of p The straight line L may be parallel to the central axis 20C of the balloon body 20. d and the 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 as shown in Figure 6. 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.

[0040] As shown in FIG. 7, the tip 61 at the 0% position D0 of the distal tapered portion 24 and the tip 61 at the 100% position D 100 A straight line L connecting the tip 61 of d、 and the distal end 61 at the 0% position D0 of the proximal tapered portion 22 and the 100% position D 100 A straight line L connecting the tip 61 of p The imaginary curved surface C may have an angle in the radial direction y with respect to the central axis 20C of the balloon body 20.d and virtual surface C p 7, the line L is 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 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.

[0041] 6 and 7, 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 cylinder or 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.

[0042] 6 and 7, the distal sleeve portion 25 and the proximal sleeve portion 21 also have protrusions 60, but the distal sleeve portion 25 and the proximal sleeve portion 21 do not have to have protrusions 60, and the distal sleeve portion 25 and the proximal sleeve portion 21 may have inner protrusions that protrude 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 protrusions 60, it will be easier to insert the balloon 2 into a body cavity and to advance and retract it within the body cavity.

[0043] As described above, in the balloon 2 according to the embodiment of the present invention, the distal tapered portion 24 and the proximal tapered portion 22 have at least some of the protruding portions 60 whose tip ends 61 are in a contracted state and are curved in a predetermined range within the virtual curved surface C d and virtual surface C p In the expanded state, the distal tapered portion 24 and the proximal tapered portion 22 are arranged outward in the radial direction y of the balloon body 20. d and virtual surface C p It is preferable that the protrusions 60 are not disposed outward in the radial direction y of the balloon body 20. This reduces the risk that the tip ends 61 of the protrusions 60 in the tapered portion other than the straight tube portion 23 that acts on the lesion will come into contact with areas of normal blood vessels that are not the target of treatment when the balloon 2 is expanded after delivery, and yet allows the balloon to be moved forward or backward in the contracted state to incise the stenotic portion.

[0044] As shown in Figures 8 to 11, 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, so the amount of the blades 29 wound around is large, as shown in Figure 9. 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 diameter reduction, and in one embodiment of the present invention, the length is from the 0% position D0 on the straight tube section side to the 100% position D1. 100 On the 0% position D0 side of the distal tapered portion 24 and the proximal tapered portion 22, the blades 29, which are shorter than those in the straight tube portion 23, are wound around the shaft 3 (inner tube 32) as shown in FIG. 10011, shorter blades 29 are wound around the shaft 3 (inner tube 32) on the distal side tapered portion 24 and the proximal side tapered portion 22. Alternatively, by adjusting the diameter of the balloon 2 and the number of blades 29, the amount of winding of the blades 29 can be reduced even on the 0% position D0 side of the distal side tapered portion 24 and the proximal side tapered portion 22, as shown in FIG. 100 It is also possible to make it so that almost no wings 29 are formed on the side of the balloon 2. By folding the balloon 2, the balloon 2 can be easily inserted into a body cavity.

[0045] As shown in FIG. 12, in the deflated state of the balloon 2, it is preferable that at least one of the following (1) and (2) be satisfied. (1) 90% position D of the distal tapered portion 24 90 From 100% position D 100 The tip 61 of the protrusion 60 in the 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 arranged inward in the radial direction y of the balloon body 20 or at the same position as the slits 24. (2) 90% position D of the proximal tapered portion 22 90 From 100% position D 100 The tip 61 of the protrusion 60 in the 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. Position D at the furthest 90% of the distal tapered portion 24 and the proximal tapered portion 22 from the straight tube portion 23 90 From 100% position D 100 The section up to is the part on the tip side when the balloon 2 is advanced or retreated in the body cavity, so 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 in this section is positioned on the virtual curved surface C d and virtual surface C pIf the portion is arranged inward in the radial direction y of the balloon body 20 or at the same position as the portion, the diameter of the portion can be made smaller, making it easier to insert the balloon 2 when moving it forward or backward within the body cavity.

[0046] At least one of the distal tapered portion 24 and the proximal tapered portion 22 is positioned between 80% and 100% positions D 100 The tip 61 of the protrusion 60 in the section up to is formed on the virtual curved surface C d or C p It is more preferable that the balloon body 20 is disposed inward in the radial direction y or at the same position as the balloon body 20. 100 In these sections, the tip 61 of the protrusion 60 is positioned on the virtual curved surface C d or C p If the distal end portion 24 is positioned radially inward of or at the same position as the distal end portion 24 of the balloon body 20 in the radial direction y, the diameter of the distal end portion when the balloon 2 is advanced or retracted within the body cavity can be made smaller over a longer section in the longitudinal axis direction x, making it easier to insert the balloon 2 when advancing or retracting it within the body cavity.

[0047] In FIG. 12, the virtual surface C d and virtual surface C p Although both of the above are the side surfaces of a truncated cone, either one of them may be the side surface of a cylinder as shown in FIG. 6. 90 From 100% position D 100 In the section up to, at least one of (1) and (2) above is satisfied, and the virtual curved surface C d and virtual surface C p If the side of the distal tapered portion 24 is a truncated cone, the diameters of the distal and proximal portions of the distal tapered portion 24 and the proximal tapered portion 22, respectively, can be made smaller when deflated, making it easier to insert the balloon 2 into the body cavity and move it forward or backward.

[0048] In Figure 12, the 90% position D of both tapered sections 90 From 100% position D 100However, 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 90% position D of the distal tapered portion 24 is 90 From 100% position D 100 In the 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] 13 , when the balloon 2 is inflated, the protruding portions 60 of the distal tapered section 24, the straight section 23, and the protruding portions 60 of the proximal tapered section 22 are preferably located at the same position in the circumferential direction z of the balloon body 20. When the balloon 2 is inflated, the protruding portions 60 are located at the same position in the circumferential direction z along the longitudinal axis x of the balloon 2, which allows for straight incisions and allows the protruding portions 60 to be fixed to the body cavity wall when the balloon 2 is inflated to treat a stricture.

[0050] 13, the protruding portions 60 of the distal tapered section 24, the straight 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 improve the strength of the balloon 2 and prevent the balloon 2 from over-expanding when pressurized.

[0051] As shown in Figures 4, 5, and 9 to 11, when the balloon 2 is in a deflated state, the protruding portions 60 of the straight tube section 23, the protruding portions 60 of the distal tapered section 24, and the protruding portions 60 of the proximal tapered section 22 are preferably located at the same position in the circumferential direction z of the balloon body 20. That is, the tip ends 61 of the protruding portions 60 of the distal tapered section 24 and the proximal tapered section 22 are located outward in the radial direction y of the balloon body 20 so as to satisfy the above-mentioned predetermined condition when the balloon 2 is deflated, but preferably do not move in the circumferential direction z of the balloon body 20 due to deflation. This ensures that the tip ends 61 that act on the lesion are located at the same position in the circumferential direction z, allowing for straight incisions to be made while the balloon 2 is advanced or retracted in a deflated state.

[0052] As shown in FIGS. 3 to 5 and 9 to 11, 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. 9 and 10, thereby reducing damage to the protruding portions 60 when the balloon 2 is folded and inserted into a body cavity and preventing the protruding portions 60 from acting on the body cavity wall in unintended locations. 10 and 11, by adjusting the length of the vanes 29 in the radial direction y by adjusting the diameter of the balloon 2 or the number of vanes 29, the extent to which the vanes 29 cover the protruding portions 60 in the distal tapered portion 24 and the proximal tapered portion 22 can be adjusted. That is, if the vanes 29 are short enough 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 advancing or retracting the balloon 2. Alternatively, if the vanes 29 are short enough not to cover the protruding portions 60 in the distal tapered portion 24 and the proximal tapered portion 22 near the 50% 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 stricture can be incised by using the exposed protruding portions 60 while advancing or retracting the balloon 2. 50 In this case, the portion of the protrusion 60 exposed from the wings 29 can be made smaller, thereby suppressing the action of the protrusion 60 when the balloon 2 is advanced or retracted. In this way, by adjusting the range over which the wings 29 cover the protrusion 60, it is possible to accommodate application to various lesions.

[0053] Although Figures 4, 5, and 9 to 11 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.

[0054] 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 .

[0055] 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.

[0056] 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.

[0057] 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.

[0058] As shown in FIG. 1 , the balloon catheter 1 may have a hub 4 provided on the proximal side of the shaft 3. The hub 4 may have a fluid injection section 7 that communicates with a fluid flow path for supplying fluid to the interior of the balloon 2. The hub 4 preferably has a guidewire insertion section 5 that communicates 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 side to the proximal side 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 side to the proximal side of the shaft.

[0059] 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.

[0060] 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. 14 to 19. FIG. 14 is a perspective view of a parison before expansion according to an embodiment of the present invention, showing the parison having a lumen and a thick-walled portion. FIG. 15 is a cross-sectional view perpendicular to the longitudinal axis direction of a first cylindrical object in a manufacturing method according to an embodiment of the present invention. FIG. 16 is a cross-sectional view perpendicular to the longitudinal axis direction of a second cylindrical object in a manufacturing method according to an embodiment of the present invention. FIG. 17 is a cross-sectional view perpendicular to the longitudinal axis direction of a third cylindrical object in a manufacturing method according to an embodiment of the present invention. FIG. 18 is a cross-sectional view perpendicular to the longitudinal axis direction of a manufacturing method according to an embodiment of the present invention, showing a step of disposing a distal tapered portion within the first cylindrical object. FIG. 19 is a cross-sectional view perpendicular to the longitudinal axis direction of a manufacturing method according to an embodiment of the present invention, showing a step of pressing both sides of a protrusion with a pressing member.

[0061] 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 and a second cylindrical body 320 each having a space extending in the longitudinal axis direction x therein and a pressing member 300 on its inner surface that can protrude and retract from the outside to the inside, and a third cylindrical body 330 each having a space extending in the longitudinal axis direction x therein; and a method for manufacturing a balloon catheter balloon having a balloon main body 20 having an outer surface and an inner surface, the balloon main body 20 comprising 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. The method includes a step of preparing a balloon for a balloon catheter, in which the distal tapered portion 24, the straight tube portion 23, and the proximal tapered portion 22 protrude radially outward from the outer surface of the balloon body 20 in the y direction and have a protrusion 60 extending in the x direction of the longitudinal axis of the balloon body 20; an arrangement step of arranging the distal tapered portion 24 in a first cylindrical body 310, the proximal tapered portion 22 in a second cylindrical body 320, and the straight tube portion 23 in a third cylindrical body 330; and a contraction step of contracting the balloon 2 for the balloon catheter 1, and includes at least one of the following steps (1) and (2). (1) In the contraction step, the pressing member 300 of the first cylindrical object 310 presses both sides of the protrusion 60 in a cross section perpendicular to the longitudinal axis direction x of the balloon body 20 toward the inside of the first cylindrical object 310. (2) In the contraction step, the pressing member 300 of the second cylindrical body 320 presses both sides of the protrusion 60 in a cross section perpendicular to the longitudinal axis direction x of the balloon body 20 toward the inside of the second cylindrical body 320. When both sides of the protrusion 60 of the distal tapered section 24 disposed within the first cylindrical object 310 are pressed by the retaining member 300, the protrusion 60 is guided by the retaining member 300 and can move outward in the radial direction y of the balloon body 20. As a result, the tip 61 of the protrusion 60 of the distal tapered section 24 can be positioned outward in the radial direction y of the balloon body 20. Furthermore, when the retaining member 300 presses both sides of the protruding portion 60 of the proximal tapered portion 22 disposed within the second cylindrical object 320, the protruding portion 60 is guided by the retaining member 300 and can move outward in the radial direction y of the balloon body 20. As a result, the tip 61 of the protruding portion 60 of the proximal tapered portion 22 can be positioned outward in the radial direction y of the balloon body 20.

[0062] In order to position the tip 61 of the protrusion 60 of the distal tapered portion 24 outside the radial direction y of the balloon body 20, it is sufficient to perform the above-mentioned step (1). In order to position the tip 61 of the protrusion 60 of the proximal tapered portion 22 outside the radial direction y of the balloon body 20, it is sufficient to perform the above-mentioned step (2). In order to position the tip 61 of the protrusions 60 of both the distal tapered portion 24 and the proximal tapered portion 22 outside the radial direction y of the balloon body 20, it is sufficient to perform both the above-mentioned steps (1) and (2).

[0063] In the process of preparing a balloon having protrusions 60, a cylindrical parison 200 made of resin, such as that shown in FIG. 14 , can be placed in a mold having a groove in its inner cavity and subjected to biaxial stretch blow molding to prepare the balloon. The protrusions 60 can be formed, for example, by inserting the parison 200 into the inner cavity of the mold, fitting the thick-walled portion 220 of the parison 200 into the groove, and then introducing a fluid into the inner cavity 210 of the parison 200 to expand the parison 200. Furthermore, when no protrusions 60 are formed in the distal sleeve portion 25 or the proximal sleeve portion 21, 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.

[0064] As shown in Figures 15 and 16, the first cylindrical object 310 and the second cylindrical object 320 have a space therein extending in the longitudinal axis direction, and also have a pressing member 300 at a position corresponding to the protruding portion 60 when the distal tapered portion 24 is disposed therein. It is preferable that a pair of pressing members 300 is disposed for each protruding portion 60 so as to press both sides of the protruding portion 60 in a cross section perpendicular to the longitudinal axis direction x. The third cylindrical object 330 has a space therein extending in the longitudinal axis direction, as shown in Figure 17.

[0065] 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 section 24, the length in the longitudinal direction x of the proximal tapered section 22, and the length in the longitudinal direction x of the straight tube section 23, respectively. In addition, it is preferable that the internal spaces of the first cylindrical body 310, the second cylindrical body 320, and the third cylindrical body 330 have diameters slightly larger than the outer diameter of the straight tube section 23.

[0066] 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 positions of their respective spaces coincide, and then insert the balloon 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 in the third cylindrical body 330, and the proximal tapered section 22 in the second cylindrical body 320.

[0067] 18, before the pressing step is performed, the pressing member 300 is not in contact with the protruding portion 60, whereas during the pressing step, as shown in Fig. 19, the pressing member 300 protrudes in the radial direction y and presses both sides of the protruding portion 60 in a cross section perpendicular to the longitudinal axis direction x toward the inside of the first tubular portion and / or the second tubular portion, thereby allowing the protruding portion 60 to be guided by the pressing member 300 and move outward in the radial direction y of the balloon body 20. The length of the pressing member 300 in the radial direction y can be set appropriately depending on the length of the corresponding protruding portion 60 in the radial direction y.

[0068] 19 , when it is desired to suppress movement of the tip ends 61 of the protrusions 60 of the distal tapered section 24 and / or the proximal tapered section 22 in the circumferential direction z of the balloon body 20, it is preferable to set the distance between the pair of pressing members 300 so that, for example, a pair of pressing members 300 provided for one protrusion 60 can press the vicinity of the base end of the protrusion 60. Alternatively, although not shown, by adjusting the positions of the pressing members 300, it is possible to move the tip ends 61 of the protrusions 60 outward in the radial direction y of the balloon body 20 while allowing movement of the tip ends 61 of the protrusions 60 in the circumferential direction z of the balloon body 20.

[0069] If the pressing member 300 of the first cylindrical object 310 or the pressing member 300 of the second cylindrical object 320 does not perform the pressing process, the first cylindrical object 310 or the second cylindrical object 320 may be a cylindrical object that does not have a pressing member 300, such as the third cylindrical object 330, or the pressing member 300 may be housed in the wall surface of the first cylindrical object 310 or the second cylindrical object 320 so that it does not abut against the protrusion 60.

[0070] By performing the pressing steps (1) and / or (2) 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 portion 24 and / or the proximal tapered portion 22 can be formed. The balloon 2 can then be folded by hand or using a folding machine. If the protrusion 60 is located somewhere other than the wing-forming portion 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 positioned outward in the radial direction y of the balloon body 20 in the folded state.

[0071] 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.

[0072] This application claims the benefit of priority to Japanese Patent Application No. 2020-215753, filed on December 24, 2020. The entire contents of the specification of Japanese Patent Application No. 2020-215753, filed on December 24, 2020, are incorporated herein by reference. [Explanation of symbols]

[0073] 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 300: Pressing member 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 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 D0: 0% position D 20 :20% position D 50 :50% position D 90 :90% position D 100 :100% position 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 the balloon catheter is in a deflated state, the balloon for the balloon catheter is folded, In a deflated state of the balloon for a balloon catheter, when the ends of the distal tapered portion and the proximal tapered portion on the straight tube portion side in the longitudinal axis direction of the balloon body are set to the 0% position and the other ends are set to the 100% position, the balloon for a balloon catheter satisfies at least one of the following (1) and (2): (1) The tip of the protrusion in the section from the 20% position to the 50% position of the distal tapered portion is a straight line L connecting the tip of the distal tapered portion at the 0% position and the tip of the distal tapered portion at the 100% position. ｄ is disposed radially outward of the balloon body with respect to 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 section from the 20% position to the 50% position of the proximal taper portion is a straight line L connecting the tip of the proximal taper portion at the 0% position and the tip of the proximal taper portion at the 100% position. ｐ is disposed radially outward of the balloon body with respect to an imaginary curved surface obtained by rotating the balloon body around the central axis of the balloon body.

2. 2. The balloon for a balloon catheter according to claim 1, 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 section from the 90% position to the 100% 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 section from the 90% position to the 100% 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.

3. 3. The balloon for a balloon catheter according to claim 1, wherein, in an expanded state of the balloon for a balloon catheter, 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 are arranged at the same circumferential position of the balloon body.

4. 4. The balloon for a balloon catheter according to claim 1, wherein, in a deflated state of the balloon for a balloon catheter, the protruding portion of the straight tube section, the protruding portion of the distal tapered section, and the protruding portion of the proximal tapered section are arranged at the same circumferential position of the balloon body.

5. 5. 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.

6. 6. 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.

7. 7. The balloon for a balloon catheter according to claim 1, wherein the protrusions are made of the same material as the balloon body.

8. A method for manufacturing a balloon for a balloon catheter according to any one of claims 1 to 7, comprising: preparing a first cylindrical object and a second cylindrical object each having a space extending in the longitudinal axis direction therein and a pressing member on an inner surface thereof that can be protruded and retracted from the outside to the inside, and a third cylindrical object having a space extending in the longitudinal axis direction therein; 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; an arrangement step of arranging the distal tapered portion within the first cylindrical object, the proximal tapered portion within the second cylindrical object, and the straight tube portion within the third cylindrical object; a contraction step of contracting the balloon for the balloon catheter, A method for manufacturing a balloon for a balloon catheter, comprising at least one of the following steps (1) and (2): (1) In the contraction process, the pressing member of the first cylindrical body presses both sides of the protrusion in a cross section perpendicular to the longitudinal axis direction of the balloon body toward the inside of the first cylindrical body. (2) In the contraction step, the pressing member of the second cylindrical body presses both sides of the protrusion in a cross section perpendicular to the longitudinal axis direction of the balloon body toward the inside of the second cylindrical body.

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