JP7698608B2 - Balloon for balloon catheter - Google Patents

Description

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

When narrowed areas hardened by calcification form on the inner walls of blood vessels, diseases such as angina pectoris and myocardial infarction are caused. One of the treatments for this is angioplasty, which uses a balloon catheter to expand the narrowed area. Angioplasty is a minimally invasive therapy that does not require open chest surgery like bypass surgery, and is widely performed.

A balloon catheter is inserted into a body cavity with the balloon in a deflated state and delivered to the treatment site through the body cavity. During delivery, the transport of the balloon is controlled by transmitting operations from the hand side to the tip side where the balloon is located. At this time, it is required that the catheter be easy to insert into the body cavity and that operations from the hand side be easily transmitted to the tip side (high pushability). In addition, when a fluid is introduced into the inner cavity of the balloon to expand it, there is a problem that the balloon stretches in an undesired direction or is damaged by the pressure of the fluid. To address such problems, for example, Patent Document 1 discloses a balloon catheter that improves the adhesion strength between the balloon and the outer shaft without increasing the outer diameter at the adhesion part between the balloon and the outer shaft.

International Publication No. 2017/158735

Balloon catheters are required to have not only high pushability and balloon strength, but also the ability to smoothly pass through body cavities and the ability to flexibly move along tortuous body cavities (trackability). However, conventional balloon catheters have been insufficient in achieving both improved strength and smooth insertion and improved trackability. Therefore, the object of the present invention is to provide a balloon for a balloon catheter that can be smoothly inserted through body cavities and has improved trackability and pushability while increasing the strength of the balloon to prevent the balloon from stretching in undesired directions or breaking.

A balloon for a balloon catheter according to an embodiment of the present invention is as follows.
[1] A balloon for a balloon catheter having a straight tube portion, a proximal tapered portion located proximal to the straight tube portion, a proximal sleeve portion located proximal to the proximal tapered portion, a distal tapered portion located distal to the straight tube portion, and a distal sleeve portion located distal to the distal tapered portion, wherein the balloon has a balloon body having an outer surface and an inner surface, and a protruding portion that protrudes radially outward from the outer surface of the balloon body and extends in a longitudinal axis direction of the balloon body, wherein in the radial cross section, the protruding portion provided on the straight tube portion has a base end connected to the outer surface of the balloon body, and a tip end that is located radially outward from the base end and is the radially outer end of the protruding portion, and the balloon for a balloon catheter satisfies at least one of the following (1) and (2).
(1) In the radial cross section, the protruding portion of the proximal taper section is inclined in a first or second circumferential direction of the balloon body, and the angle between a straight line connecting the midpoint of the width direction of the base end and the tip and a perpendicular line to the base end is 30° or more.
(2) In the radial cross section, the protrusion of the distal taper section is inclined in a first or second circumferential direction of the balloon body, and the angle between a straight line connecting the midpoint of the width direction of the base end and the tip and a perpendicular line to the base end is 30° or more.

The balloon for a balloon catheter according to the embodiment of the present invention is preferably any one of the following [2] to [4].
[2] A balloon for a balloon catheter according to [1], which satisfies at least one of the following (3) and (4):
(3) In the radial cross section, the protruding portion of the proximal taper portion is inclined in the first direction or the second direction, and an angle between a straight line connecting a midpoint in a width direction of the base end and the tip and a perpendicular line to the base end is 30° or more;
The proximal sleeve portion and the proximal tapered portion have an inward protrusion that protrudes radially inward beyond the inner surface of the balloon body and extends in the longitudinal axis direction.
(4) In the radial cross section, the protruding portion of the distal taper portion is inclined in the first direction or the second direction, and an angle between a straight line connecting a midpoint in a width direction of the base end and the tip and a perpendicular line to the base end is 30° or more;
The distal sleeve portion and the distal tapered portion have an inward protrusion that protrudes radially inward beyond the inner surface of the balloon body and extends in the longitudinal axis direction.
[3] A balloon for a balloon catheter according to [1] or [2], which satisfies at least one of the following (5) and (6):
(5) In the radial cross section, the protruding portion of the proximal taper portion is inclined in the first direction or the second direction, and an angle between a straight line connecting a midpoint of the base end in a width direction and the tip and a perpendicular line to the base end is 30° or more,
The protruding portion is inclined in the first direction or the second direction over the entire area in the longitudinal axial direction of the proximal taper portion.
(6) In the radial cross section, the protruding portion of the distal taper portion is inclined in the first direction or the second direction, and an angle between a straight line connecting a midpoint in a width direction of the base end and the tip and a perpendicular line to the base end is 30° or more,
The protrusion is inclined in the first direction or the second direction over the entire area in the longitudinal axial direction of the distal taper portion.
[4] A balloon for a balloon catheter according to [1] or [2], which satisfies at least one of the following (7) and (8).
(7) In the radial cross section, the protruding portion of the proximal taper portion is inclined in the first direction or the second direction, and an angle between a straight line connecting a midpoint of the base end in a width direction and the tip and a perpendicular line to the base end is 30° or more,
The protruding portion is inclined in at least a portion in the longitudinal axial direction of the proximal taper portion in the first direction or the second direction.
(8) In the radial cross section, the protruding portion of the distal taper portion is inclined in the first direction or the second direction, and an angle between a straight line connecting a midpoint in the width direction of the base end and the tip and a perpendicular line to the base end is 30° or more,
The protrusion is inclined in at least a portion in the longitudinal axial direction of the distal taper portion in the first direction or the second direction.

The present invention also provides the following:
[5] A catheter comprising a balloon for a balloon catheter according to any one of [1] to [4] above.

According to the balloon for balloon catheter, the strength of the balloon is increased by having a protrusion, and the balloon is prevented from stretching or breaking in an undesired direction, while the protrusions provided on the distal taper section and/or the proximal taper section, which are the leading sections when the balloon is advanced or retreated, are inclined in the first or second circumferential direction of the balloon body, so that the inclined protrusions act as cushions, allowing the balloon for balloon catheter to be smoothly inserted into the body cavity and improving trackability. In addition, because the protrusions provided on the distal taper section and/or the proximal taper section are inclined in the first or second circumferential direction of the balloon body, the outer diameter of the balloon can be reduced without reducing the protrusions themselves, so that both the strength of the balloon and the ease of insertion into the body cavity can be achieved.

1 illustrates a side view of a balloon catheter according to one embodiment of the present invention. 2 shows a cross-sectional view taken along line II-II in FIG. 3 shows a cross-sectional view of the balloon shown in FIG. 2 in a deflated state. 4 shows a cross-sectional view taken along line IV-IV in FIG. 5 shows a cross-sectional view of the balloon shown in FIG. 4 in a deflated state. 6 shows a cross-sectional view taken along line VI-VI in FIG. 7 illustrates a modification of FIG. 6. 1 illustrates a cross-sectional view of a balloon according to another embodiment of the present invention. 13 illustrates a cross-sectional view of a balloon according to yet another embodiment of the present invention. 13 illustrates a cross-sectional view of a balloon according to yet another embodiment of the present invention. FIG. 2 illustrates a perspective view of a parison prior to expansion according to one 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 below, and can of course be modified as appropriate within the scope of the intent described above and below, all of which are included in the technical scope of the present invention. In addition, hatching and component symbols may be omitted in each drawing for convenience, but in such cases, reference should be made to the specification or other drawings. Furthermore, the dimensions of various components in the drawings may differ from the actual dimensions, as priority is given to contributing to an understanding of the features of the present invention.

A balloon for a balloon catheter according to an embodiment of the present invention is a balloon for a balloon catheter having a straight tube portion, a proximal tapered portion located proximal to the straight tube portion, a proximal sleeve portion located proximal to the proximal tapered portion, a distal tapered portion located distal to the straight tube portion, and a distal sleeve portion located distal to the distal tapered portion, the balloon having an outer surface and an inner surface, and a protruding portion that protrudes radially outward from the outer surface of the balloon body and extends in the longitudinal direction of the balloon body, and in a radial cross section, the protruding portion provided on the straight tube portion has a base end connected to the outer surface of the balloon body, and a tip end that is located radially outward from the base end and is the radially outer end of the protruding portion, and satisfies at least one of the following (1) and (2).
(1) In a radial cross section, the protrusion provided on the proximal sleeve portion is inclined in a first or second circumferential direction of the balloon body, and the angle between a straight line connecting the midpoint of the width direction of the base end and the tip and a perpendicular line to the base end is 45° or more.
(2) In a radial cross section, the protrusion provided on the distal sleeve portion is inclined in a first or second circumferential direction of the balloon body, and the angle between a straight line connecting the midpoint of the width direction of the base end and the tip and a perpendicular line to the base end is 45° or more.

In this way, the balloon for balloon catheter according to the embodiment of the present invention has a protrusion that increases the strength of the balloon and prevents the balloon from stretching or breaking in an undesired direction, while the protrusion provided on the distal sleeve portion and/or the proximal sleeve portion that leads when the balloon is advanced or retreated is tilted in the first or second circumferential direction of the balloon body, so that the tilted protrusion acts like a cushion, allowing for smooth insertion into the body cavity and improving trackability. In addition, because the protrusion provided on the distal sleeve portion and/or the proximal sleeve portion is tilted in the first or second circumferential direction of the balloon body, the outer diameter of the balloon can be reduced without reducing the protrusion itself, so that both the strength of the balloon and the ease of insertion into the body cavity can be achieved.

With reference to Figures 1 to 10, a balloon for a balloon catheter according to an embodiment of the present invention will be described. Figure 1 shows a side view of a balloon catheter according to an embodiment of the present invention. Figure 2 shows a cross-sectional view taken along line II-II in Figure 1, showing a cross-sectional view of the straight tube portion of the balloon of the balloon catheter shown in Figure 1 in an expanded state. Figure 3 shows a cross-sectional view of the expanded portion shown in Figure 2 in a contracted state. Figure 4 shows a cross-sectional view taken along line IV-IV in Figure 1, showing a cross-sectional view of the distal tapered portion of the balloon of the balloon catheter shown in Figure 1 in an expanded state. Figure 5 shows a cross-sectional view of the distal tapered portion of the balloon shown in Figure 4 in a contracted state. Figure 6 shows a cross-sectional view taken along line VI-VI in Figure 1, showing a cross-sectional view of the distal sleeve portion of the balloon of the balloon catheter shown in Figure 1. Figure 7 shows a modified example of Figure 6. 8 to 10 show cross-sectional views of balloons for balloon catheters according to different embodiments of the present invention, with FIG. 8 showing a cross-sectional view of the distal sleeve portion, and FIGS. 9 and 10 showing cross-sectional views of the distal tapered portion in a contracted state, with FIG. 9 showing a cross-sectional view of the more distal tapered portion and FIG. 10 showing a cross-sectional view of the more proximal distal tapered portion. In this specification, balloons for balloon catheters may be simply referred to as "balloons."

In the present invention, the proximal side refers to the direction toward the user's hand relative to the extension direction of the balloon catheter 1 or the longitudinal direction of the shaft 3, and the distal side refers to the opposite direction of the proximal side, i.e., the direction toward the subject of treatment. The longitudinal axis direction of the balloon catheter 1 is preferably the same as the longitudinal axis direction x of the balloon body 20. In this specification, even if the member is not a long member, it will be described as having the same longitudinal axis direction x. The radial direction y of the balloon body 20 is a direction perpendicular to the longitudinal axis direction x, and is a direction connecting the center of the balloon body 20 and a point on the outer edge of the balloon body 20 in the expanded state in a cross section perpendicular to the longitudinal axis direction x. The circumferential direction z of the balloon body 20 is a direction along the outer edge of the balloon body 20 in the expanded state in a cross section in the radial direction y.

As shown in FIG. 1, the balloon catheter 1 has a shaft 3 and a balloon 2 provided at the distal end 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.

The shaft 3 preferably has a fluid flow path therein and also has a guide wire insertion path. In order to configure the shaft 3 to have a fluid flow path and a guide wire insertion path therein, for example, the shaft 3 may have an outer tube 31 and an inner tube 32, the inner tube 32 functions as a guide wire 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.

As shown in FIG. 1 , the balloon 2 for a balloon catheter has a straight tube portion 23, a proximal taper portion 22 located proximal to the straight tube portion 23, a proximal sleeve portion 21 located proximal to the proximal taper portion 22, a distal taper portion 24 located distal to the straight tube portion 23, and a distal sleeve portion 25 located distal to the distal taper portion 24. The balloon 20 has an outer surface and an inner surface, and 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. In a cross section in the radial direction y, the protruding portion 60 provided on the straight tube portion 23 has a base end 61 connected to the outer surface of the balloon body 20 and a tip end 62 that is located outward in the radial direction y from the base end 61 and is the outer end of the protruding portion 60 in the radial direction y. In this case, at least one of the following (1) and (2) is satisfied.
(1) In a cross section in the radial direction y, the protrusion 60 provided on the proximal sleeve portion 21 is inclined in the first direction d1 or the second direction d2 in the circumferential direction z of the balloon body 20, and the angle θ between a straight line _Lp connecting the widthwise midpoint of the base end 61 to the tip 62 and a perpendicular line _Lv of the base end 61 is 45° or greater.
(2) In a cross section in the radial direction y, the protrusion 60 provided on the distal sleeve portion 25 is inclined in the first direction d1 or the second direction d2 in the circumferential direction z of the balloon body 20, and the angle θ between a straight line _Lp connecting the widthwise midpoint of the base end 61 to the tip 62 and a perpendicular line _Lv of the base end 61 is 45° or more.
The balloon 2 has the protruding portion 60, which increases the strength of the balloon 2 and prevents the balloon 2 from stretching in an undesired direction or breaking. In addition, when the balloon 2 is inserted into a body cavity and delivered to a lesion in the body cavity, the protruding portion 60 provided on the distal sleeve portion 25 and/or the proximal sleeve portion 21, which is the leading portion in the forward or backward movement of the balloon 2, is tilted in the first direction d1 or the second direction d2 in the circumferential direction z of the balloon body 20, so that the tilted protruding portion 60 acts like a cushion, allowing the balloon 2 for a balloon catheter to be smoothly inserted into the body cavity and to have improved trackability. Furthermore, the protruding portion 60 provided on the distal sleeve portion 25 and/or the proximal sleeve portion 21 is tilted in the first direction d1 or the second direction d2 in the circumferential direction z of the balloon body 20, so that the outer diameter of the balloon 2 can be reduced without reducing the protruding portion 60 itself, thereby achieving both the strength of the balloon 2 and ease of insertion into the body cavity.

As shown in FIG. 1, the balloon 2 has a straight tube section 23, a proximal tapered section 22 located proximally of the straight tube section 23, a proximal sleeve section 21 located proximally of the proximal tapered section 22, a distal tapered section 24 located distally of the straight tube section 23, and a distal sleeve section 25 located distally of the distal tapered section 24. At least a portion of the proximal sleeve section 21 and the distal sleeve section 25 can be fixed to the shaft 3, and when the shaft 3 has an outer tube 31 and an inner tube 32, at least a portion of the proximal sleeve section 21 can be fixed to the outer tube 31, and at least a portion of the distal sleeve section 25 can be fixed to the inner tube 32.

The proximal tapered section 22, the straight tube section 23, and the distal tapered section 24 are sections that are expanded by supplying fluid to the inside of the balloon 2 through the shaft 3, and it is preferable that the proximal sleeve section 21 and the distal sleeve section 25 do not expand even when fluid is supplied to the inside of the balloon 2. This allows the fixation of the balloon 2 and the shaft 3 to be stable even when the balloon 2 is in an expanded state.

The straight tube section 23 preferably has the same diameter in the longitudinal axis direction x, and the proximal taper section 22 and the distal taper section 24 are preferably formed so that their diameters decrease with increasing distance from the straight tube section 23. By reducing the diameters of the proximal taper section 22 and the distal taper section 24, the outer diameters of the proximal and distal ends of the balloon 2 can be reduced when the balloon 2 is deflated, thereby reducing the step between the shaft 3 and the balloon 2, making it easier to insert the balloon 2 into the body cavity.

As shown in FIG. 2, the balloon 2 has a balloon body 20 having an outer surface and an inner surface, and 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. When the balloon 2 is delivered to the lesion, the balloon body 20 is expanded as shown in FIG. 2, and the protruding portion 60 can be used to perform treatment such as incising the narrowed portion of the lesion.

The protrusion 60 provided on the straight tube section 23 has a base end 61 connected to the outer surface of the balloon body 20 and a tip end 62 located radially outward of the base end 61 in the radial direction y, which is the outer end of the protrusion 60 in the radial direction y. Regardless of the shape of the cross section of the protrusion 60 in the radial direction y, the outer end in the radial direction y can be uniquely determined, and the tip 62 of the protrusion 60 can be defined. It is preferable to fix the balloon 2 to the lesion with the tip 62 or to make an incision in the lesion, and further to incise the lesion so that the protrusion 60 is inserted into the lesion up to the base end 61 side, thereby expanding the stenosis. The tip 62 of the protrusion 60 may have a sharp shape with an acute angle, or may have a shape with a curved surface or a flat surface, but from the above viewpoint, it is preferable that the tip 62 has a sharp shape.

The base end 61 has a predetermined width in the circumferential direction z of the balloon body 20, and the width of the base end 61 in the circumferential direction z is preferably 1/100 or more of the circumferential length of the balloon body 20, more preferably 1/80 or more, even more preferably 1/70 or more, and preferably 1/4 or less, more preferably 1/8 or less, and even more preferably 1/10 or less.

As shown in FIG. 2, multiple protrusions 60 may be provided in the circumferential direction z, or, although not shown, one protrusion 60 may be provided in the circumferential direction z. When multiple protrusions 60 are provided in the circumferential direction z, the number of protrusions 60 in the circumferential direction z is not particularly limited, but is preferably 2 or more, more preferably 3 or more, may be 4 or more, and is preferably 10 or less, preferably 8 or less, and may be 6 or less. In this case, the protrusions 60 are preferably arranged at intervals in the circumferential direction z, and more preferably arranged at equal intervals in the circumferential direction z. This makes it easier to fix the balloon 2 and to incise the stenosis.

The protrusions 60 may be provided continuously from the proximal end to the distal end of the balloon body 20, or may be provided intermittently. The protrusions 60 may be arranged parallel to the longitudinal axis direction x of the balloon body 20, or may be arranged in a spiral shape so as to go around the outer surface of the balloon body 20 in the circumferential direction z. If the protrusions 60 are arranged parallel to the longitudinal axis direction x, the protrusions 60 can cut the stenosis straight. If the protrusions 60 are arranged in a spiral shape, the protrusions 60 can cut the stenosis obliquely.

The cross-sectional shape of the protrusion 60 perpendicular to the longitudinal axis direction x may be any shape, and may be a substantially triangular shape as shown in FIG. 2, or may be a polygonal, sector-shaped, wedge-shaped, convex, spindle-shaped, etc.

It is preferable that the protrusion 60 provided on the straight pipe portion 23 is not inclined in either the first direction d1 or the second direction d2 in the circumferential direction z. This allows the protrusion 60 to efficiently fix the balloon 2 to the lesion and incise the stenosis. When the protrusion 60 is not inclined in either the first direction d1 or the second direction d2 in the circumferential direction z, the straight line L p connecting the midpoint in the width direction of the base end 61 and the tip 62 coincides with the perpendicular line L _v of the base end 61, that is, the angle formed by the straight line L _p connecting the midpoint in the width direction of the base end 61 and the tip 62 and the perpendicular line L _v of the base end 61 is preferably 0°. The absolute value of the angle is also allowed to be 3° or less, 5° or less, or 10° or less. In this case, the angle formed by _{the straight line L p and} the perpendicular line L _v of the base end 61 is set to an angle in the direction in which the protrusion 60 is inclined with respect to the perpendicular line L _v of the base end 61, starting from _the midpoint in the width direction of the base end 61. Here, the perpendicular line _Lv is a perpendicular line to a line segment connecting one end and the other end of the base end 61 in the circumferential direction z in a cross section in the radial direction y.

The maximum value of the height of the protrusion 60 in the straight tube portion 23 is preferably 1 time or more, more preferably 1.5 times or more, even more preferably 2 times or more, and may be 50 times or less, 30 times or less, or 10 times or less, of the membrane thickness of the balloon body 20. When the height of the protrusion 60 is within the above range, the protrusion 60 can easily incise the stenosis, and the stretching of the balloon 2 in the longitudinal axis direction x can be easily prevented, and the pushability of the balloon 2 can be improved. The height of the protrusion 60 can be obtained by subtracting the length from the centroid of the balloon body 20 to the point where the line segment intersects with the outer edge of the balloon body 20 from the length of the line segment connecting the centroid of the balloon body 20 and the tip 62 in the cross section in the radial direction y.

As shown in FIG. 3, in the contracted state of the balloon 2, the balloon body 20 in the straight tube portion 23 preferably forms the wing 29, and the wing 29 is preferably folded. At this time, the protruding portion 60 is preferably formed in a portion other than the wing 29, and the wing 29 is preferably folded so as to cover the protruding portion 60. The balloon 2 is transported in the contracted state through the body cavity to the lesion, and since the protruding portion 60 is covered by the wing 29, it is possible to prevent the protruding portion 60 from unnecessarily damaging the body cavity wall or being damaged during transport. Even in the contracted state, it is preferable that the protruding portion 60 provided on the straight tube portion 23 does not fall in either the first direction d1 or the second direction d2 of the circumferential direction z. This allows the protruding portion 60 to remain in an unfallen state when the balloon 2 is expanded.

The number of wings 29 in the deflated state of the balloon 2 is not particularly limited, but is preferably 2 or more, more preferably 3 or more, and may be 4 or more, and is preferably 10 or less, more preferably 8 or less, and even more preferably 6 or less. If the number of wings 29 is within the above range, the balloon 2 can be easily deflated.

As shown in FIG. 4, the protrusion 60 provided on the distal taper portion 24 may not be inclined in either the first direction d1 or the second direction d2 in the circumferential direction z. Although the proximal taper portion 22 is not shown, like the distal taper portion 24, the protrusion 60 provided on the proximal taper portion 22 may not be inclined in either the first direction d1 or the second direction d2 in the circumferential direction z. Since the protrusion 60 of the tapered portion is not inclined in the expanded state of the balloon 2, the protrusion 60 arranged on the tapered portion can fix the balloon 2 to the lesion and incise the stenosis. In the contracted state of the balloon 2 as shown in FIG. 5, the tapered portion is easily folded so that the outer diameter is smaller than that of the straight tube portion 23, so that the balloon 2 can be delivered to the lesion without significantly impairing the insertability of the balloon 2 even if the protrusion 60 is not inclined.

The balloon 2 satisfies at least one of the following (1) and (2).
(1) In a cross section in the radial direction y, the protrusion 60 provided on the proximal sleeve portion 21 is inclined in the first direction d1 or the second direction d2 in the circumferential direction z of the balloon body 20, and the angle θ between a straight line _Lp connecting the widthwise midpoint of the base end 61 to the tip 62 and a perpendicular line _Lv of the base end 61 is 45° or greater.
(2) In a cross section in the radial direction y, the protrusion 60 provided on the distal sleeve portion 25 is inclined in the first direction d1 or the second direction d2 in the circumferential direction z of the balloon body 20, and the angle θ between a straight line _Lp connecting the widthwise midpoint of the base end 61 to the tip 62 and a perpendicular line _Lv of the base end 61 is 45° or more.

Here, the perpendicular line _Lv is a perpendicular line to a line segment connecting one end and the other end of the base end 61 in the circumferential direction z in a cross section in the radial direction y.

6 shows a cross-sectional view of the distal sleeve portion 25, but the proximal sleeve portion 21 can be similarly described, so the description will be given with reference to FIG. 6. As shown in FIG. 6, the protruding portion 60 provided on the proximal sleeve portion 21 and/or the distal sleeve portion 25 is inclined in the first direction d1 or the second direction d2 of the circumferential direction z, and the angle θ between the straight line _Lp connecting the midpoint in the width direction of the base end 61 and the tip 62 and the perpendicular line _Lv of the base end 61 is 45° or more. With this configuration, when the balloon 2 is transported to the lesion in the body cavity, the inclined protruding portion 60 acts like a cushion between the balloon body 20 and the body cavity wall, so that the balloon 2 can be smoothly inserted into the body cavity, resulting in a balloon 2 with improved trackability. Furthermore, since the protrusion 60 is only inclined in the circumferential direction z and the protrusion 60 itself is not reduced, the outer diameter of the balloon 2 can be reduced to facilitate insertion of the balloon 2 while maintaining the effect of preventing the balloon 2 from stretching and improving the pushability by the protrusion 60. The angle θ is preferably 50° or more, more preferably 60° or more, and even more preferably 65° or more. The upper limit of the angle θ is naturally limited because the base end 61 is connected to the outer surface of the balloon body 20 and the tip 62 can only incline until it comes into contact with the outer surface of the balloon body 20, but for example, the angle θ may be 100° or less, 95° or less, or 90° or less. In this case, the angle θ formed by the straight line L _p and the perpendicular line L _{v to the base end 61 is set to the angle formed by the straight line L p} with respect to the perpendicular line L _{v to} the base end 61, starting from the midpoint in the width direction of the base end 61, in the direction in which the protrusion 60 inclines.

When the protrusion 60 is tilted in the first direction d1 or the second direction d2 of the circumferential direction z, the outer end of the protrusion 60 in the radial direction y in this state differs from the outer end when the protrusion 60 is not tilted. However, in this specification, the tip 62 when the protrusion 60 is tilted refers to the same part as the tip 62 when the protrusion 60 is not tilted.

In both the proximal sleeve portion 21 and the distal sleeve portion 25, it is preferable that the protrusions 60 are inclined in the first direction d1 or the second direction d2 of the circumferential direction z. This allows the protrusions 60 provided on both the distal sleeve portion 25 and the proximal sleeve portion 21, which are at the forefront when the balloon 2 is advanced and retreated within the body cavity, to act like a cushion, allowing the balloon 2 to be smoothly inserted into the body cavity in both the advanced and retreated cases, resulting in an improved trackability.

Alternatively, only in the distal sleeve portion 25, the protrusion 60 may be inclined in the first direction d1 or the second direction d2 of the circumferential direction z, and in the proximal sleeve portion 21, the protrusion 60 may not be inclined. As a result, the protrusion 60 provided on the distal sleeve portion 25, which is the leading portion when the balloon 2 is advanced in the body cavity, acts like a cushion, allowing the balloon 2 to be advanced easily. At this time, the protrusion 60 arranged on the proximal sleeve portion 21 can support the proximal portion of the balloon 2 against the body cavity wall during transportation, thereby improving the trackability of the balloon 2.

Alternatively, only in the proximal sleeve portion 21, the protrusion 60 may be inclined in the first direction d1 or the second direction d2 of the circumferential direction z, and in the distal sleeve portion 25, the protrusion 60 may not be inclined. This allows for treatment in which the protrusion 60 located in the distal sleeve portion 25, which is the leading side of the balloon 2, advances the balloon 2 while scraping the body cavity wall, and when the balloon 2 is retracted, it can be easily retracted due to the cushioning effect of the protrusion 60 located in the proximal sleeve portion 21 and inclined.

As shown in FIG. 7, when multiple protrusions 60 are provided in the circumferential direction z, one protrusion 60 may be inclined in a first direction d1 in the circumferential direction z, and the other protrusions 60 may be inclined in a second direction d2 in the circumferential direction z.

As shown in FIG. 6, it is preferable that a space is formed between the tip 62 of the fallen protrusion 60 and the outer surface of the balloon body 20, and it is preferable that the distance h from the outer surface of the balloon body 20 to the tip 62, which can be used as an index of the size of this space, is equal to or greater than a predetermined value. The distance h can be defined as the distance between a tangent to the outer surface of the balloon body 20 perpendicular to the line segment connecting the centroid O of the balloon body 20 and the tip 62, and a straight line parallel to the tangent and passing through the tip 62. The distance h is preferably equal to or greater than 1/5 of the thickness of the balloon body 20, more preferably equal to or greater than 1/4, and even more preferably equal to or greater than 1/2, and may also be equal to or less than 10 times, 5 times, or 3 times. If the distance h is within the above range, the size of the space formed between the tip 62 of the fallen protrusion 60 and the outer surface of the balloon body 20 can be equal to or greater than a predetermined value, and the trackability of the balloon 2 can be improved by the cushioning effect of the fallen protrusion 60.

In either case, the protrusion 60 disposed on the sleeve portion may be inclined over the entire range in the longitudinal axis direction x, or over a portion of the longitudinal axis direction x. The range over which the protrusion 60 is inclined can be determined depending on the degree of cushioning desired.

It is preferable that the balloon 2 satisfies at least one of the following (3) and (4).
(3) In a cross section in the radial direction y, the protruding portion 60 of the proximal sleeve portion 21 is inclined in the first direction d1 or the second direction d2, and the angle between a straight line L _p connecting the midpoint of the base end 61 in the width direction and the tip 62 and a perpendicular line L _v of the base end 61 is 45° or more.
The proximal sleeve portion 21 has an inner protrusion 70 that protrudes inward in the radial direction y beyond the inner surface of the balloon body 20 and extends in the longitudinal axis direction x.
(4) In a cross section in the radial direction y, the protrusion 60 of the distal sleeve portion 25 is inclined in the first direction d1 or the second direction d2, and the angle between a straight line L _p connecting the midpoint of the base end 61 in the width direction and the tip 62 and a perpendicular line L _v of the base end 61 is 45° or more.
The distal sleeve portion 25 has an inner protrusion 70 that protrudes inward in the radial direction y beyond the inner surface of the balloon body 20 and extends in the longitudinal axis direction x.

As shown in FIG. 8, the proximal sleeve portion 21 and/or the distal sleeve portion 25 preferably have an inner protrusion 70 that protrudes inward in the radial direction y from the inner surface of the balloon 20 and extends in the longitudinal direction x in the portion where the protrusion 60 is collapsed. This allows the inner protrusion 70 to improve the strength of the proximal end and/or distal end of the balloon 2 even in the portion where the protrusion 60 is collapsed. The inner protrusion 70 is preferably disposed in the same position as the protrusion 60 in the circumferential direction z. This allows the strength of the proximal end and/or distal end of the balloon 2 to be further improved.

It is preferable that the balloon 2 satisfies at least one of the following (5) and (6).
(5) In a cross section in the radial direction y, the protruding portion 60 of the proximal sleeve portion 21 is inclined in the first direction d1 or the second direction d2, and the angle θ between a straight line L _p connecting the midpoint of the base end 61 in the width direction to the tip 62 and a perpendicular line L _v of the base end 61 is 45° or more.
In a cross section in the radial direction y, the protrusion 60 of the proximal taper portion 22 is inclined in the first direction d1 or the second direction d2, and the angle between a straight line _Lp connecting the midpoint of the width of the base end 61 to the tip 62 and a perpendicular line _Lv to the base end 61 is 30° or more.
(6) In a cross section in the radial direction y, the protruding portion 60 of the distal sleeve portion 25 is inclined in the first direction d1 or the second direction d2, and the angle θ between a straight line L _p connecting the midpoint of the base end 61 in the width direction to the tip 62 and a perpendicular line L _v of the base end 61 is 45° or more.
In a cross section in the radial direction y, the protrusion 60 of the distal taper portion 24 is inclined in the first direction d1 or the second direction d2, and the angle between a straight line _Lp connecting the widthwise midpoint of the base end 61 to the tip 62 and a perpendicular line _Lv to the base end 61 is 30° or more.

As shown in Figures 9 and 10, the protrusion 60 may also be inclined in the first direction d1 or the second direction d2 in the tapered portion. Figure 9 shows a cross-sectional view of the distal tapered portion 24 on the more distal side in the contracted state, and Figure 10 shows a cross-sectional view of the distal tapered portion 24 on the more proximal side in the contracted state. In this way, the protrusion 60 is deeply inclined on the more distal side, i.e., on the end side of the balloon 2, far from the straight tube portion 23, where the length of the wing 29 in the contracted state is short, and the protrusion 60 is shallowly inclined on the more proximal side, i.e., on the straight tube portion 23 side of the balloon 2, where the length of the wing 29 in the contracted state is long. As a result, the protrusion 60 is shallower inclined closer to the straight tube portion 23, and when delivered to the lesion, the protrusion 60 arranged on the distal tapered portion 24 can easily fix the balloon 2 to the lesion and incise the stenosis. This explanation can be made similarly for the proximal tapered portion 22. In other words, it is also preferable that the protrusion 60 is deeply inclined on the more proximal side of the proximal taper section 22, i.e., the end of the balloon 2, far from the straight tube section 23, where the length of the wing 29 is short in the contracted state, and that the protrusion 60 is shallowly inclined on the more distal side, i.e., on the straight tube section 23 side of the balloon 2, where the length of the wing 29 is long in the contracted state. When the protrusion 60 is deeply inclined, it means that the distance h is short, and when the protrusion 60 is shallowly inclined, it means that the distance h is long. The degree of cushioning effect achieved by inclining the protrusion 60 can be controlled by determining how the distance h is.

Alternatively, the protrusions 60 in the tapered portion may be inclined to the same extent in the longitudinal axis direction x. Also, the protrusions 60 may have some parts that are inclined and some parts that are not inclined in the longitudinal axis direction x.

By having the protrusion 60 in the tapered section collapsed, the protrusion 60 in the tapered section can also function as a cushion, improving the trackability of the balloon 2. The effect of whether the protrusion 60 arranged in the proximal tapered section 22 and/or the distal tapered section 24 is collapsed can be seen from the effect of whether the protrusion 60 arranged in the proximal sleeve section 21 and/or the distal sleeve section 25 is collapsed.

The angle θ at which the protrusion 60 in the tapered portion is inclined is preferably 30° or more, more preferably 45° or more, and even more preferably 50° or more, and may be, for example, 95° or less, 90° or less, or 80° or less.

It is preferable that the balloon 2 satisfies at least one of (7) and (8).
(7) In a cross section in the radial direction y, the protruding portion 60 of the proximal sleeve portion 21 is inclined in the first direction d1 or the second direction d2, and the angle between a straight line L _p connecting the midpoint of the base end 61 in the width direction and the tip 62 and a perpendicular line L _v of the base end 61 is 45° or more.
In a cross section in the radial direction y, the protruding portion 60 of the proximal taper portion 22 is inclined in the first direction d1 or the second direction d2, and the angle between a straight line L _p connecting the midpoint of the base end 61 in the width direction to the tip 62 and a perpendicular line L _v of the base end 61 is 30° or more.
The proximal sleeve portion 21 and the proximal tapered portion 22 have an inward protrusion 70 that protrudes inward in the radial direction y beyond the inner surface of the balloon body 20 and extends in the longitudinal axis direction x.
(8) In a cross section in the radial direction y, the protruding portion 60 of the distal sleeve portion 25 is inclined in the first direction d1 or the second direction d2, and the angle between a straight line L _p connecting the midpoint of the base end 61 in the width direction and the tip 62 and a perpendicular line L _v of the base end 61 is 45° or more.
In a cross section in the radial direction y, the protruding portion 60 of the distal taper portion 24 is inclined in the first direction d1 or the second direction d2, and the angle between a straight line L _p connecting the midpoint of the base end 61 in the width direction to the tip 62 and a perpendicular line L _v of the base end 61 is 30° or more.
The distal sleeve portion 25 and the distal tapered portion 24 have an inward protrusion 70 that protrudes inward in the radial direction y beyond the inner surface of the balloon body 20 and extends in the longitudinal axis direction x.

In the portion where the protrusion 60 arranged in the tapered portion and the sleeve portion is collapsed, it is preferable to have an inner protrusion 70 that protrudes inward in the radial direction y from the inner surface of the balloon 20 and extends in the longitudinal axis direction x. As a result, even in the portion where the protrusion 60 is collapsed, the inner protrusion 70 can improve the strength of the proximal end and/or distal end of the balloon 2. The inner protrusion 70 is preferably arranged at the same position as the protrusion 60 in the circumferential direction z. As a result, the strength of the proximal end and/or distal end of the balloon 2 can be further improved. The inner protrusion arranged in the tapered portion is not shown, but the inner protrusion 70 in FIG. 8 can be referred to.

Examples of materials constituting the balloon body 20 include polyolefin resins such as polyethylene, polypropylene, and ethylene-propylene copolymers, polyester resins such as polyethylene terephthalate and polyester elastomers, polyurethane resins such as polyurethane and polyurethane elastomers, polyphenylene sulfide resins, polyamide resins such as polyamide and polyamide elastomers, fluorine resins, silicone resins, and natural rubbers such as latex rubber. These may be used alone or in combination of two or more. Among them, polyamide resins, polyester resins, and polyurethane resins are preferably used. In particular, elastomer resins are preferably used in terms of thinning and flexibility of the balloon body 20. For example, among polyamide resins, nylon 12 and nylon 11 are suitable as resins constituting the balloon body 20, and nylon 12 is more suitable because it can be molded relatively easily during blow molding. In addition, polyamide elastomers such as polyether ester amide elastomers and polyamide ether elastomers are preferably used 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 protruding portion 60 and the inner protruding portion 70 are preferably made of the same material as the balloon body 20. If the protruding portion 60 and the inner protruding portion 70 are made of the same material as the balloon body 20, the flexibility of the balloon 2 can be maintained while the protruding portion 60 and the inner protruding portion 70 are less likely to damage the outer surface of the balloon body 20. The balloon body 20, the protruding portion 60, and the inner protruding portion 70 are preferably integrally molded. This makes it possible to prevent the protruding portion 60 and the inner protruding portion 70 from falling off the balloon body 20.

The balloon 2 can be manufactured by placing a cylindrical parison 200 made of resin, as shown in FIG. 11, in a mold having a groove in the inner cavity, and performing biaxial stretch blow molding. The protrusion 60 can be formed, for example, by inserting the parison 200 into the inner cavity of the mold, making the thick part 220 of the parison enter the groove of the mold, and introducing a fluid into the inner cavity 210 of the parison 200 to expand the parison 200. In addition, when forming the inner protrusion 70, for example, the thick part 220 of the parison 200 can be pressed against a part of the mold without a groove, and introducing a fluid into the inner cavity 210 of the parison 200 to expand the parison 200, thereby forming the inner protrusion 70. For the material constituting the parison 200, the description of the material constituting the balloon body 20 above can be referred to.

Examples of materials constituting the shaft 3 include polyamide-based resins, polyester-based resins, polyurethane-based resins, polyolefin-based resins, fluorine-based resins, vinyl chloride-based resins, silicone-based resins, and natural rubber. These may be used alone or in combination of two or more. Of these, it is preferable that the material constituting the shaft 3 is at least one of polyamide-based resins, polyolefin-based resins, and fluorine-based resins, which can increase the slipperiness of the surface of the shaft 3 and improve the insertability of the balloon catheter 1 within the body cavity.

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 the end. Of 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 undone even if the balloon 2 is repeatedly expanded and contracted, and the bond strength between the balloon 2 and the shaft 3 can be easily increased.

As shown in FIG. 1, a hub 4 may be provided on the proximal side of the shaft 3, and the hub 4 may be provided with a fluid injection section 7 that is connected to a flow path of the fluid supplied to the inside of the balloon 2. The hub 4 preferably has a guidewire insertion section 5 that is connected to the insertion passage of the guidewire. The balloon catheter 1 has a hub 4 equipped with a fluid injection section 7 and a guidewire insertion section 5, so that the operation of supplying fluid to the inside of the balloon 2 to expand and contract the balloon 2 and the operation of delivering the balloon catheter 1 to the treatment site along the guidewire can be easily performed. In this way, not only can the balloon catheter 2 according to the embodiment of the present invention be applied to a so-called over-the-wire type balloon catheter in which the guidewire is inserted from the distal side to the proximal side of the shaft, but also to a so-called rapid exchange type balloon catheter in which the guidewire is inserted halfway from the distal side to the proximal side of the shaft.

The shaft 3 and the hub 4 can be joined by, for example, bonding with an adhesive, welding, etc. Among these, it is preferable that the shaft 3 and the hub 4 are joined by adhesion. By bonding the shaft 3 and the hub 4, it is possible to increase the bonding strength between the shaft 3 and the hub 4 and thereby increase the durability of the balloon catheter 1 when the materials constituting the shaft 3 and the hub 4 are different, for example, when the shaft 3 is composed of a highly flexible material and the hub 4 is composed of a highly rigid material.

1: Balloon catheter 2: Balloon 3: Shaft 4: Hub 5: Guide wire insertion section 7: Fluid injection section 20: Balloon body 21: Proximal sleeve section 22: Proximal tapered section 23: Straight tube section 24: Distal tapered section 25: Distal sleeve section 29: Wing 31: Outer tube 32: Inner tube 60: Protrusion 61: Base end 62: Tip 70: Inner protrusion 200: Parison 210: Lump 220: Thick wall section of parison x: Longitudinal axis direction of balloon body y: Radial direction of balloon body z: Circumferential direction of balloon body d1: First direction d2: Second direction L _v : Perpendicular line to base end L _p : Straight line θ connecting the midpoint of the width direction of the base end and the tip: Angle h between L _v and L _p : Distance from the outer surface of the balloon body to the tip in the space formed between the outer surface of the balloon body and the tip

Claims (5)

A balloon for a balloon catheter, the balloon having a straight tube section, a proximal taper section located proximally of the straight tube section, a proximal sleeve section located proximally of the proximal taper section, a distal taper section located distally of the straight tube section, and a distal sleeve section located distally of the distal taper section,
The balloon has an outer surface and an inner surface, and a protrusion protruding radially outward from the outer surface of the balloon and extending in the longitudinal axis direction of the balloon,
In the radial cross section, the protrusion provided on the straight tube portion has a base end connected to an outer surface of the balloon body, and a tip end located radially outward from the base end and being an outer end of the protrusion in the radial direction,
In the radial cross section, the protrusion provided on the straight pipe portion has an angle of 10° or less between a straight line connecting a midpoint in a width direction of the base end and the tip end and a perpendicular line to the base end,
A balloon for a balloon catheter, which satisfies at least one of the following (1) and (2):
(1) In the radial cross section, the protruding portion of the proximal taper section is inclined in a first or second circumferential direction of the balloon body, and the angle between a straight line connecting the midpoint of the width direction of the base end and the tip and a perpendicular line to the base end is 30° or more.
(2) In the radial cross section, the protrusion of the distal taper section is inclined in a first or second circumferential direction of the balloon body, and the angle between a straight line connecting the midpoint of the width direction of the base end and the tip and a perpendicular line to the base end is 30° or more. 2. The balloon for a balloon catheter according to claim 1, which satisfies at least one of the following (3) and (4):
(3) In the radial cross section, the protruding portion of the proximal taper portion is inclined in the first direction or the second direction, and an angle between a straight line connecting a midpoint in a width direction of the base end and the tip and a perpendicular line to the base end is 30° or more;
The proximal tapered portion has an inward protruding portion that protrudes radially inward beyond the inner surface of the balloon body and extends in the longitudinal axis direction.
(4) In the radial cross section, the protruding portion of the distal taper portion is inclined in the first direction or the second direction, and an angle between a straight line connecting a midpoint in a width direction of the base end and the tip and a perpendicular line to the base end is 30° or more;
The distal tapered portion has an inward protrusion that protrudes radially inward beyond the inner surface of the balloon body and extends in the longitudinal axis direction. 3. The balloon for a balloon catheter according to claim 1 or 2, which satisfies at least one of the following (5) and (6):
(5) In the radial cross section, the protruding portion of the proximal taper portion is inclined in the first direction or the second direction, and an angle between a straight line connecting a midpoint of the base end in a width direction and the tip and a perpendicular line to the base end is 30° or more,
The protruding portion is inclined in the first direction or the second direction over the entire area in the longitudinal axial direction of the proximal taper portion.
(6) In the radial cross section, the protruding portion of the distal taper portion is inclined in the first direction or the second direction, and an angle between a straight line connecting a midpoint in a width direction of the base end and the tip and a perpendicular line to the base end is 30° or more,
The protrusion is inclined in the first direction or the second direction over the entire area in the longitudinal axial direction of the distal taper portion. 3. The balloon for a balloon catheter according to claim 1 or 2, which satisfies at least one of the following (7) and (8):
(7) In the radial cross section, the protruding portion of the proximal taper portion is inclined in the first direction or the second direction, and an angle between a straight line connecting a midpoint of the base end in a width direction and the tip and a perpendicular line to the base end is 30° or more,
The protruding portion is inclined in at least a portion in the longitudinal axial direction of the proximal taper portion in the first direction or the second direction.
(8) In the radial cross section, the protruding portion of the distal taper portion is inclined in the first direction or the second direction, and an angle between a straight line connecting a midpoint in the width direction of the base end and the tip and a perpendicular line to the base end is 30° or more,
The protrusion is inclined in at least a portion in the longitudinal axial direction of the distal taper portion in the first direction or the second direction. A catheter equipped with a balloon for a balloon catheter according to claim 1 or 2.

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