JP7736718B2 - Balloon for balloon catheter - Google Patents

Description

The present invention relates to a balloon for a balloon catheter.

Diseases such as angina pectoris and myocardial infarction occur when narrowed areas harden due to calcification and other factors on the inner walls of blood vessels. 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.

In angioplasty, standard balloon catheters can sometimes have difficulty dilating narrowed areas that have hardened due to calcification or other factors. Another method for dilating narrowed areas is to place an indwelling dilation device called a stent in the narrowed area. However, this can lead to conditions such as ISR (In-Stent-Restenosis), in which excessive neointima of the blood vessel grows after treatment, causing re-narrowing of the blood vessel. In ISR lesions, the neointima is soft and has a slippery surface, so with standard balloon catheters, the balloon may shift from the lesion during inflation, potentially damaging the blood vessel.

Balloon catheters capable of dilating stenotic lesions, even in calcified or ISR lesions, have been developed that feature protrusions, blades, or scoring elements on the balloon to 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, while 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 in which inner protrusions are provided instead of outer protrusions. In contrast, there is also a balloon catheter with a higher 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).

US Patent Application Publication No. 2016/0128718 Special table 2014-506140 publication International Publication No. 2020/012851 International Publication No. 2020/012850

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 passability of the balloon by reducing the height of the scoring element at the balloon's tip to facilitate insertion into body cavities and prevent the balloon's outer diameter from increasing. However, because the height of the scoring element at the tip is reduced in such balloon catheters, it is difficult to incise the stenosis while the balloon is deflated during delivery or at the lesion. Furthermore, the balloon catheter disclosed in Patent Document 4 has a high protrusion located on the distal tapered section so that when only the distal cone region is introduced into the lesion and the balloon is expanded, the element located in the distal cone region can make an incision in the lesion while expanding the balloon. However, this is insufficient in terms of ensuring insertional ease when the balloon is deflated and incising the stenosis by advancing or retracting the balloon.

In consideration of the above circumstances, the present invention aims to provide a balloon for a balloon catheter that can incise a stenotic area in a deflated state during delivery of the balloon or when the balloon is delivered to the lesion area.

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 taken as the 0% position and the other end 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 section is positioned radially outward of the balloon body with respect to an imaginary curved surface obtained by rotating a straight line _Ld connecting the tip of the distal taper section at the 0% position and the tip of the distal taper section at the 100% position 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 section is positioned radially outward of the balloon body with respect to an imaginary curved surface obtained by rotating a straight line _Lp connecting the tip of the proximal taper section at the 0% position and the tip of the proximal taper section at the 100% position around the central axis of the balloon body.

When the balloon for the balloon catheter is in a deflated state, it is preferable that the balloon for the balloon catheter be folded.

In a deflated state, the balloon for a balloon catheter preferably satisfies at least one of the following conditions (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 positioned radially inward of the balloon body or at the same position as the imaginary curved surface obtained by rotating the straight line _Ld 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 positioned radially inward of the balloon body or at the same position as the imaginary curved surface obtained by rotating the straight line _Lp around the central axis of the balloon body.

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

When the balloon for a balloon catheter is in a deflated state, it is preferable that the protrusions of the straight tube section, the protrusions of the distal tapered section, and the protrusions of the proximal tapered section are arranged at the same circumferential position of the balloon body.

The balloon body has a wing forming portion that forms wings in a deflated state, and it is preferable that the protrusion be located outside the wing forming portion.

It is preferable that the protrusions of the distal tapered section, the straight section, and the protrusions of the proximal tapered section extend continuously in the longitudinal axis direction of the balloon body.

It is preferable that the protrusions are made of the same material as the balloon body.

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 a retaining member on its inner surface that can be protruded and retracted 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 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.

With the above-mentioned balloon for balloon catheters, 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 specified conditions. Therefore, during delivery of the balloon or when the balloon is delivered to the lesion, the stenotic portion can be incised by moving the balloon forward or backward in the deflated state.

1 is a side view of a balloon catheter according to an embodiment of the present invention. 2 is a longitudinal sectional view of the balloon catheter shown in FIG. 1 in an expanded state of the balloon. FIG. 3 shows a cross-sectional view taken along line III-III in FIG. 3 shows a radial cross-sectional view of the straight tube portion of the balloon shown in FIG. 2 in a contracted state. 3 shows a radial cross-sectional view of the tapered portion of the balloon shown in FIG. 2 in a deflated state. 3 shows a partial longitudinal cross-sectional view of the balloon shown in FIG. 2 in a deflated state. 10 is a partial longitudinal cross-sectional view of a balloon according to another embodiment of the present invention in a deflated state. FIG. 3 shows a side view of the balloon shown in FIG. 2 in a folded state. 9 shows a cross-sectional view taken along line IX-IX in FIG. 8. XX cross-sectional view of FIG. 8. 11 shows a cross-sectional view taken along the line XI-XI in FIG. 8. 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. 3 shows a plan view of the balloon shown in FIG. 2 as seen from the protruding portion side. FIG. 2 illustrates a perspective view of a parison prior to expansion according to one embodiment of the present invention. 3A and 3B are cross-sectional views perpendicular to the longitudinal axis direction of a first cylindrical object in a manufacturing method according to one embodiment of the present invention. 3A and 3B are cross-sectional views perpendicular to the longitudinal axis direction of a second cylindrical object in a manufacturing method according to one embodiment of the present invention. 10 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. 10A and 10B are cross-sectional views perpendicular to the longitudinal axis direction during the step of placing a distal tapered portion within a first cylindrical object in a manufacturing method according to one embodiment of the present invention. 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.

The present invention will be described in detail below based on the embodiments, but the present invention is not limited to the embodiments described below. It is of course possible to make appropriate modifications within the scope of the spirit described above and below, and all such modifications are within the technical scope of the present invention. For convenience, hatching and component symbols may be omitted in the drawings. In such cases, please refer to the specification or other drawings. The dimensions of various components in the drawings may differ from their actual dimensions, as priority is given to aiding understanding of the features of the present invention.

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 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 taken as the 0% position and the other end 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 section is positioned radially outward of the balloon body with respect to an imaginary curved surface obtained by rotating a straight line _Ld connecting the tip of the distal taper section at the 0% position and the tip of the distal taper section at the 100% position 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 section is positioned radially outward of the balloon body with respect to an imaginary curved surface obtained by rotating a straight line _Lp connecting the tip of the proximal taper section at the 0% position and the tip of the proximal taper section at the 100% position 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."

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 tube portion of the balloon shown in Figure 2 in a contracted state, and Figure 5 shows a radial cross-sectional view of the tapered portion 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 IX-IX, X-X, and XI-XI cross-sectional views 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 the protrusions. Fig. 13 is a plan view of the balloon shown in Fig. 2, seen from the protrusion side.

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 direction from 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 and 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.

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 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 pressurized fluid pressurized by a pump or the like.

The shaft 3 preferably has an internal fluid flow path and also has a guidewire insertion path. For example, the shaft 3 can be configured to have an internal fluid flow path and a guidewire insertion path by having an outer tube 31 and an inner tube 32, with the inner tube 32 functioning as a guidewire insertion path and the space between the inner tube 32 and the outer tube 31 functioning as a fluid flow path. In this configuration in which the shaft 3 has an outer tube 31 and an inner tube 32, it is preferable that the inner tube 32 extends from the distal end of the outer tube 31 and penetrates distally beyond the balloon 2, with the distal side of the balloon 2 joined to the inner tube 32 and the proximal side of the balloon 2 joined to the outer tube 31.

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, 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 having a tip portion 61 in a cross section of the balloon body 20 in the radial direction y, and 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 D ₀ and the other ends are designated as a 100% position D When the value is ₁₀₀ , at least one of the following (1) and (2) is satisfied.
(1) The tip 61 of the protrusion 60 in the section from the 20% position D20 of the distal taper section ₂₄ to the ₅₀ % position D50 of the distal taper section 24 is disposed radially outward of the balloon body ₂₀ with respect to an imaginary curved surface _Cd obtained by rotating a straight line _Ld connecting the tip 61 of the distal taper section 24 at the 0% position D0 and the tip 61 of the distal taper section ₂₄ at the 100% position D100 around the central axis 20C of the balloon body 20.
(2) The tip 61 of the protrusion 60 in the section from the 20% position D20 of the proximal taper section ₂₂ to the ₅₀ % position D50 is disposed radially outward of the balloon body ₂₀ with respect to an imaginary curved surface _Cp obtained by rotating a straight line _Lp connecting the tip 61 of the proximal taper section 22 at the 0% position D0 and the tip 61 of the proximal taper section ₂₂ at the 100% position D100 around the central axis 20C 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 narrowed site using the tip 61.

As shown in FIG. 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.

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. The balloon body 20 has a straight tube portion 23 that has its maximum diameter in the expanded state, allowing the straight tube portion 23 to make sufficient contact with the stenotic site when the balloon 2 is expanded at the stenotic site, facilitating dilation and incision of the stenotic site. Furthermore, as described below, wings 29 are formed when the balloon 2 is deflated. Because the balloon body 20 has a distal tapered portion 24 and a proximal tapered portion 22 whose outer diameters 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, protrusions 60 at the distal tapered portion 24 and the proximal tapered portion 22 are exposed from the wings 29 of the balloon 2. These exposed protrusions 60 allow incision of the stenotic site even when the balloon 2 is deflated.

As shown in Figures 2 and 3, the protrusion 60 of the balloon 2 is a portion that protrudes 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 protrusion 60 protrudes radially outward in the y direction from the outer surface of the balloon body 20 in a cross section of 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 protrusion 60 to be at most 100 times, 50 times, 30 times, or 10 times. This makes it easier to make an incision of an appropriate depth in the stricture, facilitating incision. Such a protrusion 60 not only facilitates incision of the stricture, but also improves the strength of the balloon 2 and prevents over-expansion of the balloon 2 when pressurized.

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, it is preferable that the multiple protrusions 60 are spaced apart in the circumferential direction z, and it is more preferable that they are arranged at equal intervals in the circumferential direction z. The separation distance is preferably longer than the maximum circumferential length of the protrusions 60. By arranging the protrusions 60 at intervals in the circumferential direction z, preferably at equal intervals, it becomes easier to fix the balloon 2 and to incise the stricture.

As shown in FIG. 3, the protrusion 60 has a tip 61 in a cross section of the balloon body 20 taken along the radial direction y. 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 perspective of ease of incision, a shape with an acute angle is preferable. The shape of the protrusion 60 in a cross section of the radial direction y may be any shape, including a roughly triangular shape as shown in FIG. 3, a polygonal, fan-shaped, wedge-shaped, convex, spindle-shaped, etc.

As shown in Figures 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. 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. In other words, as shown in Figure 3, the expanded balloon 2 has a wing-forming portion 28 that forms the wings 29 in the deflated state. In the embodiment shown in Figures 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 (the distal tapered section 24 or the proximal tapered section 22). As can be seen from comparing the straight tubular section 23 with the tapered section 22, the straight tubular section 23 is the section of the balloon 2 that has the largest diameter in an expanded state, and the tapered section is the section with a reduced diameter. Therefore, in the cross-section in the radial direction y, 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 cross-section in the radial direction y also gradually decreases toward the distal and proximal sides, respectively. Consequently, the 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 the distal tapered section 24 and the proximal end of the proximal tapered section 22. If wings 29 are not formed at the distal end portion of the distal tapered section 24 and the proximal end portion of the proximal tapered section 22, the protrusion 60 can abut against the body cavity wall at those portions without being obstructed by the wings 29, making it possible to incise the stricture portion.

As shown in Figures 6 and 7 , when the balloon 2 is in a deflated state, the ends of the distal taper section 24 and the proximal taper section 22 on the straight tube section 23 side in the longitudinal axis direction x of the balloon body 20 are defined as the 0% position D ₀ and the other ends are defined as the 100% position D _100. In this case, the tip ends 61 of the protrusions _{60 in at least one of the section of the distal taper section 24 from the 20% position D 20 to} the 50% position D ₅₀ and the section of the proximal taper section 22 from the 20% position D ₂₀ to the 50% position D ₅₀ are positioned radially outward in the y direction of the balloon body 20 with respect to the imaginary curved surface C _d obtained by rotating the line L _d around the central axis 20C of the balloon body 20 and the imaginary curved surface C _p obtained by rotating the line L p around the central axis 20C of the balloon body 20C. That is, when the balloon 2 is deflated, the tip ends 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 tip end 61 of the protrusion 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 tip ends 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 tip ends 61 can be used to act on the stenotic portion and make an incision 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 narrowed 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 stenotic portion, thereby improving the subsequent insertability of the balloon 2. Furthermore, the balloon 20 can easily pass through the body cavity when retracted.

Figure 5 shows a tapered portion in which the tip 61 of the protrusion 60 is 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 tip 61 of the protrusion 60 is 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 protrusion 60 is formed is raised above the shaft 3 (inner tube 32), and the portion other than this portion and the vanes 29 may be close to the shaft 3 (inner tube 32). This allows the tip 61 of the protrusion 60 to be disposed radially outward of the balloon body 20 in the y direction while reducing the outer diameter of the portion other than this portion and the vanes 29. This allows the tip 61 of the protrusion 60 of the tapered portion to be disposed radially outward of the balloon body 20, while reducing the outer diameter of the balloon 2 when folded, thereby enabling the balloon 2 to be easily inserted into a body cavity.

In at least one of the distal tapered section 24 and the proximal tapered section 22, 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 20% position _D20 to the 50% position _D50 . In 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. Furthermore, 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 D100 (excluding the 0% position _D0 and the 100% position _D100 ).

The amount of protrusion of the tip 61 of the protrusion 60 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 cross section. However, from the perspective of insertability of the balloon 2 in its expanded state, it is preferable to adjust the amount of protrusion of the tip 61 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 cross section of the tapered portion. With this configuration, the balloon 2 can be advanced or retracted within the body cavity, allowing the tip 61 of the protrusion 60 positioned outward in the radial direction y to incise the stenotic area. 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.

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 by which the tip 61 of the protrusion 60 protrudes in the radial direction y from the balloon body 20, it is possible to apply the balloon 2 to treatment sites in various conditions.

With regard to the radial y length of the protrusion 60 in a radial y cross section, it is preferable that the length of the protrusion 60 in the distal tapered section 24 or the proximal tapered section 22 is 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 from the shaft 3 (inner tube 32) as described above.

In the expanded state, it is preferable that the tip ends 61 of the protrusions 60 in the distal tapered section 24 and the proximal tapered section 22 are not disposed outward from the straight lines _Ld and _Lp , thereby reducing the risk that, in the expanded state of the balloon 2, the tip ends 61 of the protrusions 60 in the tapered sections other than the straight tube section 23 that acts on the lesion will come into contact with areas such as normal blood vessels that are not the target of treatment.

As shown in Fig. 6, a line Ld connecting the tip 61 of the distal taper section 24 at the 0% position _D0 and the tip 61 of the distal taper section ₂₄ at the 100% position D100 _, and a line _Lp connecting the tip 61 of the proximal taper section 22 at the 0% position _D0 and the tip 61 of the proximal taper section ₂₂ at the 100% position D100, may be parallel to the central axis 20C of the balloon body 20. When the lines _Ld and _Lp are parallel to the central axis 20C of the balloon body 20, the imaginary curved surfaces _Cd and _Cp become the side surfaces of a cylinder, as shown in Fig. 6. If the lines _Ld and _Lp are 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 wings 29 formed by the deflation of the balloon 2 are wrapped around the shaft 3, making it easier to insert the balloon into the body cavity.

As shown in Fig. 7 , a straight line Ld connecting the tip 61 of the distal taper section 24 at the 0% position _D0 and the tip 61 of the distal taper section ₂₄ at the 100% position D100 _, and a straight line _Lp connecting the tip 61 of the proximal taper section 22 at the 0% position _D0 and the tip 61 of the proximal taper section ₂₂ at the 100% position D100, may be angled in the radial direction y with respect to the central axis 20C of the balloon body 20. In such a case, the imaginary curved surfaces _Cd and _Cp become the side surfaces of a truncated cone as shown in Fig. 7 . In cases where the diameter of the balloon 2 is large, or where the radial length of the protruding portion 60 at the straight tube portion 23 is longer than the radial length of the protruding portion 60 at the distal tapered portion 24 and the proximal tapered portion 22 in the radial cross section in the radial direction y, the line _Ld or the line _Lp will be angled in the radial direction y with respect to the central axis 20C of the balloon body 20, and the imaginary curved surface _Cd or the imaginary curved surface _Cp will be the side surface of a truncated cone whose bottom faces the straight tube portion 23. In such a configuration, the diameters of the distal and proximal portions of the distal tapered portion 24 and the proximal tapered portion 22, respectively, can be kept small during deflation, and the diameter of the portion that will be the tip when the balloon 2 is inserted into and moved forward or backward in a body cavity will be small, facilitating insertion of the balloon 2 into the body cavity.

6 and 7 show an embodiment in which the imaginary curved surface _Cd and the imaginary curved surface _Cp in the distal tapered portion 24 and the proximal tapered portion 22 are both the side surfaces of a cylinder or a truncated cone, but the imaginary curved surface _Cd in the distal tapered portion 24 may be the side surface of a cylinder and the imaginary curved surface _Cp in the proximal tapered portion 22 may be the side surface of a truncated cone, or vice versa.

In the embodiment shown in Figures 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 may not 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 the body cavity and to move it forward and backward within the body cavity.

As described above, in the balloon 2 according to the embodiment of the present invention, the tips 61 of at least some of the protrusions 60 of the distal tapered section 24 and the proximal tapered section 22 are disposed outward in the radial direction y of the balloon body 20 from the imaginary curved surfaces _Cd and _Cp within a predetermined range in the deflated state, but in the expanded state, it is preferable that the tips 61 of the protrusions 60 of the distal tapered section 24 and the proximal tapered section 22 are not disposed outward in the radial direction y of the balloon body 20 from the imaginary curved surfaces _Cd and _Cp . This reduces the risk that the tips 61 of the protrusions 60 in the tapered sections other than the straight tube section 23 that acts on the lesion will come into contact with areas such as normal blood vessels that are not the target of treatment when the balloon 2 is expanded after delivery, and yet the balloon can be moved forward or backward to incise a stenotic site.

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 that wrap 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 becomes shorter from the 0% position _D0 on the straight tube section side to the 100% position _D100 . On the 0% position _D0 side of the distal tapered section 24 and the proximal tapered section 22, shorter wings 29 than those on the straight tube section 23 are wound around the shaft 3 (inner tube 32) as shown in Fig. 10 , and on the 100% position _D100 side, even shorter wings 29 are wound around the shaft 3 (inner tube 32) as shown in Fig. 11 . Alternatively, by adjusting the diameter of the balloon 2 and the number of wings 29, the amount of winding of the wings 29 can be reduced even on the 0% position _D0 side of the distal tapered section 24 and the proximal tapered section 22, as shown in Fig. 11 , or it can be made so that almost no wings 29 are formed on the 100% position _D100 side. By folding the balloon 2, the balloon 2 can be easily inserted into a body cavity.

As shown in FIG. 12, in the deflated state of the balloon 2, it is preferable that at least one of the following conditions (1) and (2) be satisfied.
(1) The tip 61 of the protrusion 60 in the section from the 90% position _D90 to the ₁₀₀ % position D100 of the distal tapered section 24 is positioned inside or at the same position in the radial direction y of the balloon body 20 with respect to the imaginary curved surface _Cd obtained by rotating the straight line _Ld around the central axis 20C of the balloon body 20.
(2) The tip 61 of the protrusion 60 in the section from the 90% position _D90 to the ₁₀₀ % position D100 of the proximal tapered section 22 is positioned inside or at the same position in the radial direction y of the balloon body 20 with respect to the imaginary curved surface _Cp obtained by rotating the straight line _Lp around the central axis 20C of the balloon body 20.
The section of the distal tapered section 24 and the proximal tapered section 22 from the straight tube section 23, which is the farthest 90% position _D90 , to the 100% position _D100 , is the part that will be the tip side when the balloon 2 is advanced or retracted within the body cavity. Therefore, if the tip end 61 of the protrusion 60 of at least one of the distal tapered section 24 and the proximal tapered section 22 in this section is positioned inward in the radial direction y of the balloon body 20 with respect to the imaginary curved surfaces _Cd and _Cp when the balloon 2 is in a deflated state, the diameter of this section can be reduced, and the balloon 2 can be easily inserted when advanced or retracted within the body cavity.

In at least one of the distal tapered section 24 and the proximal tapered section 22, it is more preferable that the tip end 61 of the protrusion 60 in the section from the 80% position to the ₁₀₀ % position D100 is located inward in the radial direction y of the balloon body 20 with respect to the imaginary curved surface _Cd or _Cp or at the same position, and the section from the 70% position to the 100% position _D100 is even more preferable. If the tip end 61 of the protrusion 60 in these sections is located inward in the radial direction y of the balloon body 20 with respect to the imaginary curved surface _Cd or _Cp or at the same position, the diameter of the tip side when advancing or retracting the balloon 2 within the body cavity can be reduced 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.

While Figure 12 shows an embodiment in which both imaginary curved surfaces _Cd and _Cp are the side surfaces of a truncated cone, either one or both may be the side surfaces of a cylinder as shown in Figure 6. If at least one of the above conditions (1) and (2) is satisfied in the section from the 90% position _D90 to the ₁₀₀ % position D100, and if imaginary curved surfaces _Cd and _Cp are the side surfaces of a truncated cone, the diameters of the distal and proximal portions of distal tapered section 24 and proximal tapered section 22, respectively, can be made smaller during deflation, making it easier to insert balloon 2 into a body cavity and move it forward or backward.

While Figure 12 shows an embodiment in which the sections from the 90% position _D90 to the 100% position _D100 of both tapered sections satisfy the above conditions (1) and (2), the balloon 2 according to the present invention also includes an embodiment in which either the distal tapered section 24 or the proximal tapered section 22 satisfies the above conditions (1) or (2). From the viewpoint of improving the ease of insertion when inserting the balloon 2 into a body cavity and advancing it to a lesion, it is preferable that the tip end 61 of the protrusion 60 be positioned inward in the radial direction y of the balloon body 20 with respect to or at the same position as the imaginary curved surface _Cd in the section of the distal tapered section 24 from the ₉₀ % position D90 to the ₁₀₀ % position D100. This allows the diameter of the distal end portion of the balloon 2 when inserted and advanced into a body cavity to be reduced, making it easier to insert the balloon 2 through the body cavity.

As shown in Figure 13, when the balloon 2 is in an expanded state, the protrusions 60 of the distal tapered section 24, the protrusions 60 of the straight tube section 23, and the protrusions 60 of the proximal tapered section 22 are preferably arranged at the same position in the circumferential direction z of the balloon body 20. When the balloon 2 is in an expanded state, the protrusions 60 are arranged at the same position in the circumferential direction z across the longitudinal axis direction x of the balloon 2, which makes it possible to make a straight incision and fix the protrusions 60 to the body cavity wall when expanding the balloon 2 to perform treatment at a stenotic area.

As shown in Figure 13, it is preferable that the protrusions 60 of the distal tapered section 24, the protrusions 60 of the straight tube section 23, and the protrusions 60 of the proximal tapered section 22 extend continuously in the longitudinal axis direction x of the balloon body 20. By having the protrusions 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 over-expansion of the balloon 2 when pressurized.

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 specified conditions when 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 acting 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.

As shown in Figures 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 protrusions 60 are preferably located outside the wing-forming portions 28. If the protrusions 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 Figures 4 and 5, multiple wings 29 are formed in the deflated state, and the protrusions 60 are preferably located between the multiple wings 29. This allows the wings 29 to protect the protrusions 60 when the balloon 2 is folded, as shown in Figures 9 and 10, thereby suppressing damage to the protrusions 60 when the balloon 2 is folded and inserted into a body cavity and preventing the protrusions 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, 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 advancing or retracting the balloon 2. Alternatively, the wings 29 can be made long enough to cover the protrusions 60 beyond the 50% position _D50 of the distal taper portion 24 and the proximal taper 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.

Figures 4, 5, and 9 to 11 show an embodiment with three vanes 29, but 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, or five or more vanes are also acceptable. 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 when folded, thereby improving insertion into the body cavity. Furthermore, the number of vanes 29 is preferably, for example, ten or fewer vanes, more preferably eight or fewer vanes, and even more preferably six or fewer vanes. 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.

Examples of materials constituting the balloon body 20 include polyolefin-based resins such as polyethylene, polypropylene, and ethylene-propylene copolymer; polyester-based resins such as polyethylene terephthalate and polyester elastomer; polyurethane-based resins such as polyurethane and polyurethane elastomer; polyphenylene sulfide-based resins; polyamide-based resins such as polyamide and polyamide elastomer; fluorine-based resins; silicone-based resins; and natural rubber such as latex rubber. These materials may be used alone or in combination. Among these, polyamide-based resins, polyester-based resins, and polyurethane-based resins are preferred. Elastomer resins are particularly preferred in terms of thinning and flexibility of the balloon body 20. For example, among polyamide-based resins, nylon 12 and nylon 11 are preferred as resins constituting the balloon body 20, with nylon 12 being more preferred due to its relatively easy moldability during blow molding. Furthermore, polyamide elastomers such as polyetheresteramide elastomers and polyamideether elastomers are preferred in terms of thinning and flexibility of 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 .

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 as a single unit. This prevents the protrusions 60 from falling off the balloon body 20.

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. It is preferable that the material used to form the shaft 3 be at least one of polyamide resins, polyolefin resins, and fluorine-based resins. This increases the slipperiness of the shaft 3 surface and improves the ease of insertion of the balloon catheter 1 into the body cavity.

The balloon 2 and 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 shaft 3 be joined by welding. By welding the balloon 2 and shaft 3, the bond between the balloon 2 and shaft 3 is less likely to come undone even when the balloon 2 is repeatedly expanded and contracted, and the bond strength between the balloon 2 and shaft 3 can be easily increased.

As shown in FIG. 1 , the balloon catheter 1 may have a hub 4 on the proximal side of the shaft 3. The hub 4 may have a fluid injection section 7 that is connected to a fluid flow path for supplying fluid to the interior of the balloon 2. The hub 4 preferably also has a guidewire insertion section 5 that is connected to a guidewire insertion passage. The balloon catheter 1 includes a hub 4 equipped with the fluid injection section 7 and the guidewire insertion section 5, facilitating 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. As shown in FIG. 1 , the balloon 2 according to 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, 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.

The shaft 3 and hub 4 can be joined by, for example, adhesive bonding or welding. Among these, it is preferable that the shaft 3 and hub 4 be joined by adhesive bonding. By bonding the shaft 3 and hub 4 together, the bond strength between the shaft 3 and hub 4 can be increased, thereby improving the durability of the balloon catheter 1, even when the shaft 3 and 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.

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 Figures 14 to 19. Figure 14 shows 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. Figure 15 shows 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. Figure 16 shows 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. Figure 17 shows 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. Figure 18 shows a cross-sectional view perpendicular to the longitudinal axis direction of a manufacturing method according to an embodiment of the present invention, during the step of positioning a distal tapered portion within the first cylindrical object. Figure 19 shows a cross-sectional view perpendicular to the longitudinal axis direction of a manufacturing method according to an embodiment of the present invention, during the step of pressing both sides of the protrusion with a pressing member.

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 object 310, the proximal tapered portion 22 in a second cylindrical object 320, and the straight tube portion 23 in a third cylindrical object 330; and a contraction step of contracting the balloon 2 for the balloon catheter 1, and includes at least one of the steps (1) and (2) below.
(1) In the contraction process, 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 process, 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.
The retaining member 300 presses both sides of the protrusion 60 of the distal tapered portion 24 disposed within the first cylindrical object 310, allowing the protrusion 60 to be guided by the retaining member 300 and 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 portion 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.

In order to position the tip 61 of the protrusion 60 of the distal tapered portion 24 radially outward from the balloon body 20 in the y direction, it is sufficient to carry out step (1) above; in order to position the tip 61 of the protrusion 60 of the proximal tapered portion 22 radially outward from the balloon body 20 in the y direction, it is sufficient to carry out step (2) above; and in order to position the tip 61 of the protrusions 60 of both the distal tapered portion 24 and the proximal tapered portion 22 radially outward from the balloon body 20 in the y direction, it is sufficient to carry out both steps (1) and (2) above.

In the process of preparing a balloon having a protrusion 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 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, if the distal sleeve portion 25 or the proximal sleeve portion 21 does not have a protrusion 60 or if 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, please refer to the description of the material constituting the balloon body 20 above.

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 protrusion 60 when the distal tapered portion 24 is positioned therein. It is preferable that a pair of pressing members 300 are arranged for each protrusion 60 so that they can press both sides of the protrusion 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.

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. Furthermore, 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.

In the above-mentioned placement process, it is preferable to arrange the first cylindrical body 310, the third cylindrical body 330, and the second cylindrical body 320 in this order along the longitudinal axis x so that the positions of their respective spaces coincide, and then insert the balloon into the space from the second cylindrical body 320 side. This allows the distal tapered section 24 to be placed in the first cylindrical body 310, the straight tube section 23 to be placed in the third cylindrical body 330, and the proximal tapered section 22 to be placed in the second cylindrical body 320.

As shown in Figure 18, before the pressing process is performed, the pressing member 300 is not in contact with the protruding portion 60, whereas during the pressing process, as shown in Figure 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 radial length y of the pressing member 300 can be set appropriately depending on the radial length y of the corresponding protruding portion 60.

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 spacing between the pair of retaining members 300 so that, for example, a pair of retaining members 300 provided for one protrusion 60 can retain the vicinity of the base end of the protrusion 60, as shown in Figure 19. Alternatively, although not shown, by adjusting the positions of the retaining 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.

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 without 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.

By performing the above 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 proximal tapered portion 22 can be formed. The balloon 2 can then be folded by hand or using various folding machines. If the protrusion 60 is positioned other than in the wing-forming portion 28, it is preferable to fold the balloon 2 so that the wing 29 covers the protrusion 60. By folding the balloon 2 without disrupting the formed position of the tip 61 of the protrusion 60, a balloon 2 can be obtained in which the tip 61 of the protrusion 60 is positioned radially outward of the balloon body 20 in the folded state.

The materials constituting 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.

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.

1: Balloon catheter 2: Balloon 3: Shaft 4: Hub 5: Guide wire insertion section 7: Fluid injection section 20: Balloon body 20C: Central axis of balloon body 21: Proximal sleeve section 22: Proximal tapered section 23: Straight tube section 24: Distal tapered section 25: Distal sleeve section 28: Wing forming section 29: Wing 31: Outer tube 32: Inner tube 60: Protrusion 61: Tip section 200: Parison 210: Lump 220 of parison: Thick-walled section 300 of parison: Pressing member 310: First cylindrical object 320: Second cylindrical object 330: Third cylindrical object L _d : Straight line L _p connecting the tip of the distal tapered section D ₀ and the tip of D ₁₀₀ : Straight line C _d connecting the tip of the proximal tapered section D ₀ and the tip of D ₁₀₀ : L Imaginary curved surface obtained by rotating _Ld around the central axis of the balloon body _Cp : Imaginary curved surface obtained by rotating _Lp around the central axis of the balloon body _D0 : 0% position _D20 : 20% position _D50 : 50% position _D90 : 90% position _D100 : 100% position x: longitudinal direction y: radial direction z: circumferential direction

Claims (8)

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 taper section is positioned radially outward of the balloon body with respect to an imaginary curved surface obtained by rotating a straight line _Ld connecting the tip of the distal taper section at the 0% position and the tip of the distal taper section at the 100% position 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 section is positioned radially outward of the balloon body with respect to an imaginary curved surface obtained by rotating a straight line _Lp connecting the tip of the proximal taper section at the 0% position and the tip of the proximal taper section at the 100% position around the central axis of the balloon body. 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 section is positioned radially inward of the balloon body or at the same position as an imaginary curved surface obtained by rotating the straight line _Ld 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 taper section is positioned radially inward of the balloon body or at the same position as the imaginary curved surface obtained by rotating the straight line _Lp around the central axis of the balloon body. 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. 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. 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 disposed outside the wing forming portions. 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. The balloon for a balloon catheter according to any one of claims 1 to 6 , wherein the protrusions are made of the same material as the balloon body. 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.