Balloon for balloon catheter and balloon catheter provided with the same

Abstract

To provide a balloon for a balloon catheter which is provided with a projection part on its surface, can incise a stenosis part by the balloon in a contracted state, and is improved in a function of expanding the stenosis part even in an expanded state, and to provide a balloon catheter provided with the balloon.SOLUTION: Provided is a balloon 20 for a balloon catheter, including: a balloon body part 26 having an outer surface and an inner surface; and a projection part 27 projecting outward in a radial direction y and extending in a longitudinal axis direction x on the outer surface of the balloon body part 26; wherein the projection part 27 in a straight pipe part 23 has an ST-part notch 28ST, the protruding part 27 in a distal-side taper part 24 has a DT-part notch 28DT, and both of a depth D3 of the ST-part notch 28ST and a depth D4 of the DT-part notch 28DT are 50 μm or more, and the depth D3 and the depth D4 satisfy a relationship of D3>D4.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a balloon for a balloon catheter and a balloon catheter including the same. [Background technology]

[0002] Angioplasty, in which a balloon catheter is inserted into the narrowed area of ​​a blood vessel and the balloon is expanded to expand the blood vessel and ensure blood flow, is widely used as a minimally invasive therapy. Angioplasty is used to treat diseases such as myocardial infarction caused by narrowing of the coronary artery of the heart, and to treat narrowing of shunts for dialysis.

[0003] In angioplasty, it is sometimes difficult to dilate stenotic areas that have hardened due to calcification, etc., using a general balloon catheter. In addition, a method of dilating the stenotic area by placing an indwelling dilatation device called a stent at the stenotic area is also used, but this can lead to lesions such as ISR (In-Stent-Restenosis), in which the neointima of the blood vessel grows excessively after treatment, causing stenosis again. In ISR lesions, the neointima is soft and has a slippery surface, so when a general balloon catheter is used to dilate the balloon, the position of the balloon may shift from the lesion, causing damage to the blood vessel.

[0004] As a balloon catheter capable of expanding the stenosis even in such a calcified lesion or ISR lesion, a balloon catheter provided with a protrusion, blade, or scoring element for penetrating the stenosis has been developed. For example, Patent Document 1 discloses a balloon catheter having a scoring element made of a polymeric material having a higher rigidity than the polymeric material forming the balloon body, and the scoring element is flattened at one end and the other end of the balloon. Patent Document 2 discloses a scoring balloon structure in which the height of the scoring element decreases along the tapered shape of the balloon, and Patent Document 3 discloses a balloon catheter in which an outer protrusion is provided on the straight tube part of the balloon and an inner protrusion is provided on the tapered part. In the above Patent Documents 1 to 3, the height of the scoring element decreases at both ends of the balloon, or an inner protrusion is provided instead of an outer protrusion. In contrast, there is also a balloon catheter having a high protrusion part in which the protrusion amount of the protrusion arranged on the distal tapered part is larger than that of the protrusion arranged on the straight tube part of the balloon (Patent Document 4). [Prior art documents] [Patent documents]

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

[0006] A balloon catheter is inserted into a body cavity in a deflated and folded state and delivered to a treatment site. For this reason, in the balloon catheters disclosed in the above Patent Documents 1 to 3, the height of the scoring element at the tip of the balloon is suppressed to prevent the outer diameter from increasing so that the balloon can be easily inserted into a body cavity, thereby attempting to improve the passability of the balloon. In addition, in the balloon catheter disclosed in the above Patent Document 4, the height of the protrusion arranged in the tip cone region is increased so that when only the tip cone region is introduced into the lesion and the balloon is expanded while making an incision in the lesion with the element provided in the tip cone region. However, in any of these balloons, it was not assumed that the stenosis would be incised while the balloon was advanced or retreated in the deflated state.

[0007] In view of the above circumstances, an object of the present invention is to provide a balloon for a balloon catheter, which has protrusions on its surface, and which is capable of incising a stricture when in a contracted state, and which is less slippery when in an expanded state, thereby preventing slippage from the stricture, and a balloon catheter equipped with said balloon. [Means for solving the problem]

[0008] A balloon for a balloon catheter according to an embodiment of the present invention that solves the above problems 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 catheter has a balloon main body portion having an outer surface and an inner surface, and a protruding portion protruding radially outward from the outer surface of the balloon main body portion and extending in the longitudinal direction, the protruding portion in the straight tube portion has an ST portion notch, and the protruding portion in the distal tapered portion has a DT portion notch, a depth D3 of the ST portion notch and a depth D4 of the DT portion notch are both 50 μm or more, and the depth D3 of the ST portion notch and the depth D4 of the DT portion notch satisfy the relationship D3>D4.

[0009] Since the protrusion is disposed on the distal tapered portion where the outer diameter of the balloon body when expanded gradually decreases from the straight tube portion, the protrusion on the distal tapered portion is easily exposed from the vanes when the balloon is deflated, and can contribute to the incision of the stenosis. At this time, since the depth of the DT notch of the protrusion on the distal tapered portion is relatively shallow, the rigidity of the protrusion on the distal tapered portion can be increased, and the protrusion on the distal tapered portion can be incised by an operation such as moving the balloon forward (crawling forward) while deflated. In addition, since the depth of the ST notch of the protrusion on the straight tube portion is relatively deep, each segment of the protrusion divided by the ST notch in the straight tube portion can act on the stenosis and function as an anchor. As a result, when the balloon is expanded and the protrusion on the straight tube portion is exposed from the vanes, the balloon can be made less slippery, and the balloon can be prevented from slipping off the stenosis. In this way, the balloon for balloon catheter according to the embodiment of the present invention can incise and expand the narrowed area not only when the balloon is expanded but also when it is deflated, and can prevent the balloon from shifting during expansion, making it applicable to a variety of lesions.

[0010] The balloon for a balloon catheter according to an embodiment of the present invention is preferably any one of the following [2] to

[12] . [2] The ST part notch is a plurality of ST part notches, and the depth D3 is the average of the depths of the plurality of ST part notches. The balloon for a balloon catheter according to [1]. [3] The DT part notch is a plurality of DT part notches, and the depth D4 is the average of the depths of the plurality of DT part notches. The balloon for a balloon catheter according to [1] or [2]. [4] The height H3 of the protruding part in the straight tube part and the height H4 of the protruding part in the distal tapered part satisfy the relationship H3≧H4. The balloon for a balloon catheter according to any one of [1] to [3]. [5] The protruding part in the proximal tapered part has a PT part notch, the depth D2 of the PT part notch is 50 μm or more, and the depth D3 of the ST part notch and the depth D2 of the PT part notch satisfy the relationship D3<D2. The balloon for a balloon catheter according to any one of [1] to [4]. [6] The PT part notch is a plurality of PT part notches, and the depth D2 is the average of the depths of the plurality of PT part notches. The balloon for a balloon catheter according to [5]. [7] The height H3 of the protruding part in the straight tube part and the height H2 of the protruding part in the proximal tapered part satisfy the relationship H3≧H2. The balloon for a balloon catheter according to any one of [1] to [6]. [8] The depth D3 of the ST part notch and the height H3 of the protruding part in the straight tube part satisfy the relationship D3≧H3×1 / 4. The balloon for a balloon catheter according to any one of [1] to [7]. [9] The depth D4 of the DT part notch and the height H4 of the protruding part in the distal tapered part satisfy the relationship D4≧H4×1 / 4. The balloon for a balloon catheter according to any one of [1] to [8].

[10] A balloon for a balloon catheter according to any one of [1] to [9], wherein the protruding portion in the proximal taper portion has a PT portion notch, the depth D2 of the PT portion notch is 50 μm or more, and the depth D2 of the PT portion notch and the height H2 of the protruding portion in the proximal taper portion satisfy the relationship D2 ≧ H2 × 1 / 4.

[11] The balloon for a balloon catheter according to any one of [1] to

[10] , wherein the number of the ST portion notches is greater than the number of the DT portion notches.

[12] A balloon for a balloon catheter described in any one of [1] to

[11] , wherein the protruding portion in the proximal taper portion has a PT portion notch, the depth D2 of the PT portion notch is 50 μm or more, and the number of the ST portion notches is greater than the number of the PT portion notches.

[0011] The present invention also provides the following:

[13] A balloon catheter comprising the balloon for a balloon catheter according to any one of [1] to

[12] above. Effect of the Invention

[0012] According to the balloon for balloon catheter and the balloon catheter including the balloon catheter, the depth of the notch in the protruding portion in the distal taper portion is relatively shallow, so that the rigidity of the protruding portion in the distal taper portion can be improved, and the stenosis can be incised by moving the balloon forward (crawling forward) in a deflated state. In addition, the depth of the notch in the straight tube portion is relatively deep, so that each segment of the protruding portion divided by the notch in the straight tube portion acts on the stenosis and functions as an anchor. This makes it possible to make the balloon less slippery when the balloon is expanded, and prevents the balloon from slipping off the stenosis. [Brief description of the drawings]

[0013] [Figure 1] 1 is a side view of a balloon catheter according to an embodiment of the present invention. [Diagram 2]FIG. 2 is a cross-sectional view of the balloon catheter shown in FIG. 1 along line II-II. [Diagram 3] FIG. 2 is a perspective view of a balloon of the balloon catheter shown in FIG. 1. [Figure 4] 1 is a longitudinal cross-sectional view of a balloon according to one embodiment of the present invention. FIG. [Diagram 5] FIG. 2 is a side view of a balloon in a deflated state according to one embodiment of the present invention. [Figure 6] 6 is a cross-sectional view of the balloon shown in FIG. 5 taken along line VI-VI. [Figure 7] FIG. 7 is a cross-sectional view taken along line VII-VII of the balloon shown in FIG. 5. [Figure 8] FIG. 13 is a perspective view of a balloon according to another embodiment of the present invention. [Figure 9] FIG. 9 is a side view of the balloon shown in FIG. 8 in a deflated state. [Figure 10] 10 is a cross-sectional view taken along the line XX in FIG. 9. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] The present invention will be described below based on the embodiments, but the present invention is not limited to the following embodiments, and can be modified as appropriate within the scope of the above and below, and all of these 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, the specification and other drawings should be referred to. Furthermore, the dimensions of various components in the drawings may differ from the actual dimensions, since priority is given to helping understand the features of the present invention.

[0015] 1. Balloons for balloon catheters A balloon for a balloon catheter according to an embodiment of the present invention will be described with reference to Figs. 1 to 10. Fig. 1 is a side view of a balloon catheter according to an embodiment of the present invention. Fig. 2 is a II-II cross-sectional view of the balloon catheter shown in Fig. 1, showing a cross-section perpendicular to the longitudinal axis direction of a portion of the straight tube part of the balloon where no notch is arranged in the protruding part. Fig. 3 is a perspective view of the balloon of the balloon catheter shown in Fig. 1. Figs. 2 and 3 show the balloon in an expanded state. Fig. 4 is a cross-sectional view of the longitudinal axis direction of a balloon according to an embodiment of the present invention, showing an enlarged view of a portion where a protruding part is arranged. Fig. 5 is a side view of a balloon according to an embodiment of the present invention in a contracted state. Fig. 6 is a VI-VI cross-sectional view of the balloon shown in Fig. 5, showing a configuration in which a vane is formed on the straight tube part in a contracted state and the protruding part on the straight tube part is covered by the vane. Fig. 7 is a VII-VII cross-sectional view of the balloon shown in Fig. 5, showing a configuration in which a vane is formed on the distal taper part in a contracted state and at least a part of the protruding part on the distal taper part is exposed from the vane. Fig. 8 is a perspective view of a balloon according to another embodiment of the present invention. Fig. 8 shows a balloon in an expanded state. Fig. 9 is a side view of the balloon shown in Fig. 8 in a deflated state. Fig. 10 is a cross-sectional view taken along line XX of the balloon shown in Fig. 9, showing a configuration in which wings are formed on the proximal tapered portion in the deflated state and at least a part of the protruding portion of the proximal tapered portion is exposed from the wings.

[0016] As shown in FIG. 1, the balloon 20 is provided at the distal portion of the balloon catheter 10. The balloon 20 is connected to the distal portion of the shaft 30, and the balloon 20 can be expanded by introducing a fluid through the inner cavity of the shaft 30, and can be deflated by discharging the fluid. To control the expansion and contraction of the balloon 20, a fluid can be introduced or discharged using an indeflator (balloon pressurizer). The fluid may be a pressurized fluid pressurized by a pump or the like. The balloon catheter 10 will be described in detail in the section "2. Balloon Catheter."

[0017] 1 to 10, the balloon 20 has a longitudinal axis direction x, a radial direction y that is a direction connecting the centroid of the circumscribing circle of the balloon 20 and a point on the circumscribing circle in a cross section perpendicular to the longitudinal axis direction x, and a circumscribing direction z that is a direction along the circumscribing circle. In this specification, the direction toward the user's hand in the longitudinal axis direction x is referred to as the proximal side, and the side opposite to the proximal side, i.e., the direction toward the treatment subject, is referred to as the distal side.

[0018] Each of the components and parts other than the balloon 20 has a longitudinal axis direction, a radial direction, and a circumferential direction, which may be the same as or different from the longitudinal axis direction x, radial direction y, and circumferential direction z of the balloon 20. However, for ease of understanding, this specification will be described as assuming that all components and parts have the same longitudinal axis direction, radial direction, and circumferential direction as the longitudinal axis direction x, radial direction y, and circumferential direction z of the balloon 20.

[0019] As shown in Figures 1 and 3, a balloon 20 for a balloon catheter according to an embodiment of the present invention has a straight tube section 23, a proximal taper section 22 located proximal to the straight tube section 23, a proximal sleeve section 21 located proximal to the proximal taper section 22, a distal taper section 24 located distal to the straight tube section 23, and a distal sleeve section 25 located distal to the distal taper section 24.

[0020] The proximal taper section 22 and the distal taper section 24 are preferably formed so that the diameter decreases with increasing distance from the straight tube section 23. With this configuration, the straight tube section 23 of the balloon 20 can have the maximum diameter in the expanded state, and the straight tube section 23 can be brought into sufficient contact with the lesion by expanding the balloon 20 at the lesion, making it easy to expand or incise the stenosis. In addition, since the balloon 20 has the proximal taper section 22 and the distal taper section 24, the outer diameter of the proximal end section and the distal end section of the balloon 20 can be reduced when the balloon 20 is deflated, thereby reducing the step between the shaft 30 and the balloon 20, and the balloon 20 can be easily inserted into a body cavity, a forceps channel of an endoscope, or a delivery catheter such as a guiding catheter.

[0021] Furthermore, as described below, when the balloon 20 is deflated, the balloon main body 26 is formed into wings 29, but since the diameter of the balloon main body 26 becomes smaller in the proximal taper section 22 and the distal taper section 24 as it moves away from the straight tube section 23, the length of the formed wings 29 in the circumferential direction z becomes shorter. Therefore, when the balloon 20 is deflated and the wings 29 are wrapped around the shaft 30, at least a part of the protruding parts 27 in the proximal taper section 22 and the distal taper section 24 can be exposed from the wings 29, and the exposed parts of the protruding parts 27 can incise the stenotic part even when the balloon 20 is deflated.

[0022] It is preferable that the proximal sleeve portion 21 and the distal sleeve portion 25 are portions that do not expand even when the balloon 20 is in an expanded state. This allows at least a portion of the proximal sleeve portion 21 and the distal sleeve portion 25 to be stably fixed to the shaft 30. In the case where the shaft 30 has an inner shaft 31 and an outer shaft 32 as described below, at least a portion of the proximal sleeve portion 21 can be fixed to the outer shaft 32, and at least a portion of the distal sleeve portion 25 can be fixed to the inner shaft 31.

[0023] 2 and 3, the balloon 20 has a balloon main body 26 having an outer surface and an inner surface, and a protruding portion 27 protruding outward in the radial direction y from the outer surface of the balloon main body 26 and extending in the longitudinal axis direction x. The balloon main body 26 is a portion that defines the basic shape of the balloon 20, and its outer shape is preferably a cylindrical shape in the straight pipe portion 23, a truncated cone shape in the tapered portion, and a cylindrical shape with a smaller diameter than the straight pipe portion 23 in the sleeve portion. In other words, the protruding portion 27 is a portion that is formed thicker than the thickness of a portion where the protruding portion 27 is not provided, i.e., a portion where the balloon main body 26 is exposed.

[0024] The thickness of the protruding portion 27 of the balloon 20 is, for example, preferably 1.2 times or more, more preferably 1.5 times or more, even more preferably 1.8 times or more, 2.0 times or more, or 2.5 times or more, the thickness of the portion of the balloon 20 where the protruding portion 27 is not provided. There is no particular upper limit to the thickness of the protruding portion 27 of the balloon 20, and it may be, for example, 30 times or less, 20 times or less, or 10 times or less the thickness of the portion of the balloon 20 where the protruding portion 27 is not provided.

[0025] It is preferable that no unevenness is formed in the portion of the balloon 20 where the protrusion 27 is not provided, and it is preferable that the thickness of the portion of the balloon 20 where the protrusion 27 is not provided, i.e., the thickness of the balloon main body 26, is uniform in the longitudinal axis direction x and the circumferential direction z. Here, the unevenness does not include surface roughness that is inevitably formed during manufacturing. This makes it easy to uniformly expand the balloon 20, and makes it easier to achieve the scoring function of the protrusion 27 as desired. However, the thickness of the balloon main body 26 in the straight pipe portion 23, the thickness of the balloon main body 26 in the tapered portion, and the thickness of the balloon main body 26 in the sleeve portion may be different from each other, and the thickness of the balloon main body 26 in the straight pipe portion 23 may be the thinnest. This makes it possible to obtain a balloon 20 with improved flexibility.

[0026] 2, the protrusion 27 has an apex 27t and a base 27b. The apex 27t is a portion including the outer end of the protrusion 27 in the radial direction y, and the base 27b is a portion including the boundary with the balloon main body 26, i.e., the inner end of the protrusion 27 in the radial direction y.

[0027] The balloon 20 has the protrusions 27, which can provide the balloon 20 with a scoring function. By contacting and digging into the lumen wall of the stenosis, the protrusions 27 can crack even the calcified lumen wall of the stenosis. Therefore, the stenosis can be expanded while suppressing dissection of the vascular intima. In addition, the thickness and rigidity of the protrusions 27 can improve the rigidity of the balloon 20, which can increase the pressure resistance of the balloon 20 and suppress overexpansion when pressurized.

[0028] 3, the protrusion 27 is provided so as to extend in a ridge-like manner in the longitudinal axis direction x on the outer surface of the balloon main body 26. Note that the protrusion 27 has a notch 28, which will be described later, and the protrusion 27 extending in a ridge-like manner in the longitudinal axis direction x may be interrupted by the notch 28. Even in this case, when the protrusion 27 extends to both the distal side and the proximal side of the notch 28 in the longitudinal axis direction x, it can be said that one protrusion 27 extends in the longitudinal axis direction x.

[0029] 2 and 3, a plurality of protrusions 27 may be provided in the circumferential direction z, or, although not shown, only one protrusion 27 may be provided in the circumferential direction z. The number of protrusions 27 in the circumferential direction z may be 1 or more, 2 or more, 3 or more, 4 or more, 6 or more, and may be 20 or less, 15 or less, or 10 or less. When a plurality of protrusions 27 are provided in the circumferential direction z, the plurality of protrusions 27 are preferably spaced apart in the circumferential direction z, and more preferably arranged at approximately equal intervals in the circumferential direction z. The separation distance is preferably longer than the maximum length of the protrusions 27 in the circumferential direction z.

[0030] The protrusion 27 is preferably provided on the straight pipe section 23 and the distal taper section 24, and the range in which the protrusion 27 is arranged in the longitudinal axis direction x may be a partial section or the entire section of the straight pipe section 23, and may be a partial section or the entire section of the distal taper section 24. The protrusion 27 may be arranged on the proximal taper section 22, and the range in which the protrusion 27 is arranged in the longitudinal axis direction x may be a partial section or the entire section of the proximal taper section 22. Furthermore, the protrusion 27 may be provided on the proximal sleeve section 21 and / or the distal sleeve section 25, and the range in which the protrusion 27 is arranged in the longitudinal axis direction x may be a partial section or the entire section of the proximal sleeve section 21 and / or the distal sleeve section 25. Here, the range in which the protrusion 27 is arranged in the longitudinal axis direction x includes a portion that is torn by a notch 28 described later. When the balloon main body 26 is exposed by the notch 28, the length of the exposed portion in the longitudinal direction x is preferably shorter than the maximum length in the longitudinal direction x of the protruding portion segment 27S described below. In this configuration, one protruding portion 27 extends in the longitudinal direction x including the notch 28. Alternatively, the protruding portion 27 may be provided in a part of each of the proximal taper portion 22 and the straight tube portion 23 in the longitudinal direction x, and the length of the exposed portion in the longitudinal direction x may be longer than the length of the protruding portion segment 27S in the longitudinal direction x, so that a plurality of protruding portions 27 are arranged in the longitudinal direction x.

[0031] The cross-sectional shape of the protrusion 27 in a cross section perpendicular to the longitudinal axis direction x may be any shape, such as a triangle, a rectangle, a polygon, a semicircle, a part of a circle, an approximately circle, a sector shape, a wedge shape, a convex shape, a spindle shape, or a combination thereof. The triangle, rectangle, and polygon include shapes with clear corner apexes and straight sides, as well as so-called rounded polygons with rounded corners and shapes with at least some of the sides curved. Alternatively, the cross-sectional shape of the protrusion 27 may be an irregular shape having irregularities, chips, or the like. For example, the protrusion 27 may have a cross-sectional shape that differs depending on the position in the longitudinal axis direction x, such as a protrusion 27 having an approximately triangular cross-sectional shape in a portion where the notch 28 is not provided and a cross-sectional shape that is approximately trapezoidal in a portion where the notch 28 is provided.

[0032] 3, the protrusion 27 in the straight pipe section 23 has an ST portion notch 28ST, and the protrusion 27 in the distal tapered section 24 has a DT portion notch 28DT. The ST portion notch 28ST is a notch provided in the straight pipe section 23, and the DT portion notch 28DT is a notch provided in the distal tapered section 24, but hereinafter, the notches may be collectively referred to as notch 28 regardless of where they are provided.

[0033] The notch 28 can be provided so as to form a recess in the top 27t of the protruding portion 27 extending in the longitudinal axis direction x. In this case, the notch 28 may be formed by cutting off a part of the top 27t of the protruding portion 27. As shown in FIG. 4, the notch 28 has a bottom 28b disposed at the deepest position in the depth direction of the notch 28 described below, and a top 28t which is a boundary with the top 27t of the protruding portion 27. Since the notch 28 is provided so as to form a recess in the top 27t of the protruding portion 27, it is preferable that one notch has two tops 28t in a cross section in the longitudinal axis direction x passing through the top 27t of the protruding portion 27.

[0034] The depth D3 of the ST portion notch 28ST and the depth D4 of the DT portion notch 28DT are preferably 50 μm or more. The depths D3 and D4 are more preferably 70 μm or more, and even more preferably 100 μm or more. If the lower limit of the depth of the notch 28 is above the above, the protrusion 27 can be divided into a plurality of protrusion segments 27S in the longitudinal axis direction x. That is, by providing the ST portion notch 28ST in the straight pipe portion 23, the protrusion segments 27S can be arranged at both ends of the ST portion notch 28ST in the longitudinal axis direction x, and by providing the DT portion notch 28DT in the distal taper portion 24, the protrusion segments 27S can be arranged at both ends of the DT portion notch 28DT in the longitudinal axis direction x. In the longitudinal axis direction x, the apex 28t of the notch 28 is located at the end of the protrusion segment 27S.

[0035] The upper limit of the depth of the notch 28 is the height of the protrusion 27 at the position where the notch 28 is provided. A method for determining the height of the protrusion 27 will be described later. The depth D3 of the ST portion notch 28ST is preferably 500 μm or less, more preferably 400 μm or less, and even more preferably 300 μm or less. The depth D4 of the DT portion notch 28DT is preferably 400 μm or less, more preferably 300 μm or less, even more preferably 200 μm or less, and particularly preferably 100 μm or less.

[0036] As shown in FIG. 4, the depth of the notch 28 can be the distance between the point where a perpendicular line intersects with the imaginary line connecting the two apexes 28t of the notch 28 and the point where the perpendicular line intersects with the bottom 28b of the notch 28 when a perpendicular line is drawn from the imaginary line connecting the two apexes 28t of the notch 28 to the bottom 28b of the notch 28 in a cross section in the longitudinal axis direction x passing through the apex 27t of the protruding portion 27. In the example of FIG. 4, the imaginary line connecting the apexes 28t of the ST portion notch 28ST is parallel to the longitudinal axis direction x, and the depth D3 is obtained as the distance between the imaginary line in the radial direction y and the bottom 28b of the ST portion notch 28ST. In the distal taper portion 24, the imaginary line connecting the apexes 28t of the DT portion notch 28DT is not parallel to the longitudinal axis direction x, but the depth D4 can be obtained by drawing a perpendicular line from the imaginary line to the bottom 28b of the DT portion notch 28DT. The cross section in the longitudinal direction x passing through the apex 27t of the protrusion 27 is a cross section passing through the centroid of the balloon main body 26 in a cross section perpendicular to the longitudinal direction x, i.e., the central axis of the balloon main body 26. The same applies to other parts described in this specification as "a cross section in the longitudinal direction x passing through the apex 27t of the protrusion 27."

[0037] The shape of the notch 28 is not particularly limited. In a cross section in the longitudinal direction x passing through the top 27t of the protrusion 27, the shape of the notch 28 may be a V-shape, a U-shape, a shape with one side removed from a rectangle, or a combination of these shapes. Regardless of the shape, the bottom 28b arranged at the deepest position in the depth direction can be specified, so the depth can be determined by the above definition. The bottom 28b of the notch 28 may or may not reach the base 27b of the protrusion 27. The balloon main body 26 may be exposed at the bottom of the notch 28 by the bottom 28b of the notch 28 reaching the base 27b of the protrusion 27. Even if the balloon main body 26 is exposed at the bottom of the notch 28, if the length of the exposed part in the longitudinal direction x is shorter than the maximum length of the protrusion segment 27S in the longitudinal direction x, the exposed part is considered to be a part of the notch 28 rather than a non-existent part of the protrusion 27.

[0038] 3 and 4, the depth D3 of the ST portion notch 28ST and the depth D4 of the DT portion notch 28DT satisfy the relationship D3>D4. That is, the depth D3 of the ST portion notch 28ST provided in the protruding portion 27 of the straight pipe portion 23 is deeper than the depth D4 of the DT portion notch 28DT provided in the protruding portion 27 of the distal tapered portion 24. When a plurality of notches 28 are provided in the straight pipe portion 23 and / or the distal tapered portion 24, it is sufficient that any one of them satisfies the relationship D3>D4. Alternatively, all of the plurality of notches 28 may satisfy the relationship D3>D4.

[0039] When multiple protrusions 27 are provided in the circumferential direction z of the balloon 20, it is preferable that at least one pair of notches 28 in the straight tube section 23 and the distal tapered section 24 in each protrusion 27 satisfy the relationship D3>D4. Alternatively, all of the multiple protrusions 27 may have one or more pairs of notches 28 that satisfy the relationship D3>D4.

[0040] The relationship D3>D4 may be satisfied by the bottom 28b of the ST-portion notch 28ST reaching the base 27b of the protrusion 27 and the bottom 28b of the DT-portion notch 28DT not reaching the base 27b of the protrusion 27. Alternatively, the relationship D3>D4 may be satisfied in a state in which neither the bottom 28b of the ST-portion notch 28ST nor the bottom 28b of the DT-portion notch 28DT reaches the base 27b of the protrusion 27. Alternatively, the relationship D3>D4 may be satisfied in a state in which both the bottom 28b of the ST-portion notch 28ST and the bottom 28b of the DT-portion notch 28DT reach the base 27b of the protrusion 27.

[0041] As shown in FIG. 5, the balloon 20 can be in a contracted state before a fluid is introduced into the lumen or after the fluid once introduced is discharged. When the balloon 20 is in an expanded state, the balloon body 26 in the straight tube portion 23 has a cylindrical shape as shown in FIG. 2. When the balloon 20 is in a contracted state, the wings 29 are formed in the balloon 20 as shown in FIG. 5 to FIG. 7. The wings 29 are folded to reduce the outer diameter of the balloon 20 so that the lumen wall of the balloon body 26 approaches the shaft 30. That is, as shown in FIG. 2, the balloon 20 in the expanded state can be said to have the wing forming portion 29a, and the longer the length of the wing forming portion 29a in the circumferential direction z, the longer the wing 29 can be formed. As shown in FIG. 6, the straight tube portion 23 is the portion having the maximum diameter when expanded, so the length of the wing 29 in the straight tube portion 23 is long, and the protruding portion 27 in the straight tube portion 23 can be covered by the wing 29 in the contracted state.

[0042] In contrast, as shown in Fig. 7, in the distal taper section 24 where the outer diameter of the balloon body 26 when expanded gradually decreases from the straight tube section 23, the length of the wings 29 is short, so that at least a part of the protrusion 27 in the distal taper section 24, particularly the apex 27t of the protrusion 27, can be exposed from the wings 29 even in the contracted state. As shown in Fig. 5, on the more distal side of the distal taper section 24, the protrusion 27 can be exposed almost without being affected by the wings 29. As a result, the protrusion 27 in the distal taper section 24 can contribute to the incision of the stenosis with the wings 29 folded when the balloon 20 is contracted.

[0043] At this time, since the depth D4 of the DT portion notch 28DT of the protrusion 27 in the distal taper portion 24 is relatively shallow, the rigidity of the protrusion 27 in the distal taper portion 24 can be increased, and the narrowed portion can be efficiently expanded.

[0044] In addition, since the depth D3 of the ST portion notch 28ST of the protrusion 27 in the straight pipe section 23 is relatively deep, each of the protrusion segments 27S divided by the ST portion notch 28ST in the straight pipe section 23 can act on the narrowed portion and function as an anchor. This makes it possible to make the balloon 20 less slippery when the balloon 20 is expanded and the protrusion 27 in the straight pipe section 23 is exposed from the vane 29, and prevents the balloon 20 from slipping out of the narrowed portion.

[0045] In the longitudinal direction x, the width of one notch 28, i.e., the length between two apexes 28t, is preferably shorter than the maximum length in the longitudinal direction x of the protruding portion segment 27S. The maximum length in the longitudinal direction x of the protruding portion segment 27S refers to the length of the longest one in the longitudinal direction x among the multiple protruding portion segments 27S formed by dividing them by the notches 28. This makes it possible to relatively lengthen the length in the longitudinal direction x of the protruding portion segment 27S that can contribute to the incision of the stenosis portion, thereby ensuring the stenosis portion expansion function. In addition, the rigidity of the protruding portion 27 can be made greater than a predetermined value.

[0046] 3, the most distal protruding portion segment 27S in the straight tube portion 23 may be disposed contiguous with the most proximal protruding portion segment 27S in the distal tapered portion 24. This allows the protruding portion 27 to be formed contiguous from the straight tube portion 23 to the distal tapered portion 24, making it easier to improve the rigidity of the protruding portion 27 to improve the expansion function of the stenosis portion and to improve the rigidity of the balloon 20.

[0047] In the longitudinal axis direction x, the width of one notch 28, i.e., the length between two apexes 28t, may be longer or shorter than the depth of the notch 28. For example, as shown in Fig. 4, the ratio of the width to the depth D3 of the ST portion notch 28ST in the straight pipe portion 23 (D3 / width of the ST portion notch 28ST) may be larger than the ratio of the width to the depth D4 of the DT portion notch 28DT in the distal taper portion 24 (D4 / width of the DT portion notch 28DT). This allows the length of the protruding portion segment 27S in the straight pipe portion 23 in the longitudinal axis direction x to be longer, and the rigidity of the protruding portion 27 in the straight pipe portion 23 to be improved, thereby improving the stenosis portion expansion function.

[0048] Alternatively, the ratio of the width to the depth D3 of the ST portion notch 28ST in the straight tube section 23 (D3 / width of ST portion notch 28ST) may be smaller than or equal to the ratio of the width to the depth D4 of the DT portion notch 28DT in the distal taper section 24 (D4 / width of DT portion notch 28DT).

[0049] (Claim 2) 3, the ST portion notch 28ST of the straight pipe section 23 is a plurality of ST portion notches 28ST, and the depth D3 of the ST portion notch 28ST is preferably the average of the depths of the plurality of ST portion notches 28ST. The depths of the plurality of ST portion notches 28ST formed in the straight pipe section 23 may be different from one another, and the above-mentioned effect can be achieved by making the average of the depths relatively deep.

[0050] (Claim 3) 3, the DT portion notch 28DT of the distal taper portion 24 is a plurality of DT portion notches 28DT, and the depth D4 of the DT portion notch 28DT is preferably the average of the depths of the plurality of DT portion notches 28DT. The depths of the plurality of DT portion notches 28DT formed in the distal taper portion 24 may be different from one another, and the above-mentioned effect can be achieved by making the average of the depths relatively shallow.

[0051] Although not shown, the balloon 20 may have an inner protrusion that protrudes inward in the radial direction y and extends in the longitudinal axis direction x on the inner surface of the balloon body 26. The inner protrusion may be disposed at the same position as the protrusion 27 in the longitudinal axis direction x or the circumferential direction z. The inner protrusion and the protrusion 27 are preferably integrally molded, whereby a portion of the balloon 20 may be formed thick.

[0052] The distal sleeve portion 25 may or may not be provided with a protrusion 27. When the distal sleeve portion 25 is provided with a protrusion 27, the height of the protrusion 27 may be higher or lower than the height of the protrusion 27 in the straight tube portion 23, but a preferred embodiment is a low protrusion 27 as shown in FIG. 3. When the distal sleeve portion 25 is not provided with a protrusion 27, or when it is provided with a protrusion 27, the height of the protrusion 27 is low, the insertability of the balloon 20 can be improved. In this case, it is preferable that the proximal sleeve portion 21 is provided with an inner protrusion.

[0053] The proximal side of the balloon 20, i.e., the proximal taper section 22 and the proximal sleeve section 21, may or may not be provided with a protrusion 27. As shown in Fig. 3, the proximal taper section 22 and the proximal sleeve section 21 may be provided with a low protrusion 27. This can improve the insertability of the balloon 20.

[0054] When the protrusion 27 is not provided in the proximal taper section 22 and / or the proximal sleeve section 21, it is preferable that an inner protrusion is provided. Alternatively, when the protrusion 27 is provided in the proximal taper section 22 and / or the proximal sleeve section 21 but has a low height, it is preferable that an inner protrusion is provided at the same position in the longitudinal axis direction x or the circumferential direction z as the protrusion 27. This can improve the rigidity of the proximal side of the balloon 20 and can suppress kinking and overexpansion when pressurized.

[0055] As shown in Fig. 8, it is also a preferred embodiment that the proximal taper section 22 has a protruding section 27 with a predetermined height or more. In this case, it is preferred that the protruding section 27 in the proximal taper section 22 has a PT section notch 28PT, and the depth D2 of the PT section notch 28PT is 50 µm or more, and the depth D3 of the ST section notch 28ST in the straight pipe section 23 and the depth D2 of the PT section notch 28PT satisfy the relationship D3>D2. When a plurality of notches 28 are provided in the proximal taper section 22 and / or the straight pipe section 23, it is sufficient that any one of them satisfies the relationship D3>D2. Alternatively, all of the plurality of notches 28 may satisfy the relationship D3>D2.

[0056] The relationship D3>D2 may be satisfied by the bottom 28b of the ST-portion notch 28ST reaching the base 27b of the protrusion 27 and the bottom 28b of the PT-portion notch 28PT not reaching the base 27b of the protrusion 27. Alternatively, the relationship D3>D2 may be satisfied in a state in which neither the bottom 28b of the ST-portion notch 28ST nor the bottom 28b of the PT-portion notch 28PT reaches the base 27b of the protrusion 27. Alternatively, the relationship D3>D2 may be satisfied in a state in which both the bottom 28b of the ST-portion notch 28ST and the bottom 28b of the PT-portion notch 28PT reach the base 27b of the protrusion 27.

[0057] 9 and 10, in the proximal taper section 22 where the outer diameter of the balloon body 26 during expansion gradually decreases from the straight tube section 23, the length of the wings 29 is short, so that at least a part of the protruding portion 27 in the proximal taper section 22, particularly the apex 27t of the protruding portion 27, can be exposed from the wings 29 even in the contracted state. As shown in FIG. 9, in the more proximal side of the proximal taper section 22, the protruding portion 27 can be exposed almost without being affected by the wings 29. As a result, the protruding portion 27 in the proximal taper section 22 can contribute to the incision of the stenosis with the wings 29 folded when the balloon 20 is contracted.

[0058] At this time, since the depth D2 of the PT portion notch 28PT of the protrusion 27 in the proximal taper portion 22 is relatively shallow, the rigidity of the protrusion 27 in the proximal taper portion 22 can be increased, and the narrowed portion can be efficiently expanded.

[0059] 4, the ratio of the width to the depth D3 of the ST portion notch 28ST in the straight pipe section 23 (D3 / width of the ST portion notch 28ST) may be larger than the ratio of the width to the depth D2 of the PT portion notch 28PT in the proximal taper section 22 (D2 / width of the PT portion notch 28PT). This allows the length in the longitudinal axis direction x of the protruding portion segment 27S in the straight pipe section 23 to be increased, improving the rigidity of the protruding portion 27 in the straight pipe section 23 and improving the stenosis portion expansion function.

[0060] Alternatively, the ratio of the width to the depth D3 of the ST portion notch 28ST in the straight pipe section 23 (D3 / width of ST portion notch 28ST) may be smaller than or equal to the ratio of the width to the depth D2 of the PT portion notch 28PT in the proximal taper section 22 (D2 / width of PT portion notch 28PT).

[0061] 8, the PT portion notch 28PT of the proximal taper section 22 is a plurality of PT portion notches 28PT, and the depth D2 of the PT portion notch 28PT is preferably the average of the depths of the plurality of PT portion notches 28PT. The depths of the plurality of PT portion notches 28PT formed in the proximal taper section 22 may be different from one another, and the above-mentioned effect can be achieved by making the average of the depths relatively shallow.

[0062] The depth D4 of the DT portion notch 28DT of the distal taper portion 24 and the depth D2 of the PT portion notch 28PT of the proximal taper portion 22 may be the same, or the depth D4 of the DT portion notch 28DT of the distal taper portion 24 may be shallower than the depth D2 of the PT portion notch 28PT of the proximal taper portion 22, or the depth D4 of the DT portion notch 28DT of the distal taper portion 24 may be deeper than the depth D2 of the PT portion notch 28PT of the proximal taper portion 22.

[0063] The number of ST portion notches 28ST in the straight tube section 23 is preferably greater than the number of DT portion notches 28DT in the distal taper section 24. This makes it easier to increase the number of protruding portion segments 27S in the straight tube section 23 and improve the stenosis expansion function. Also, since the number of DT portion notches 28DT in the distal taper section 24 is relatively small, the rigidity of the protruding portion 27 in the distal taper section 24 can be improved, improving the stenosis expansion function when the balloon 20 is deflated.

[0064] When the protruding portion 27 in the proximal taper portion 22 has the PT portion notch 28PT, the depth D2 of the PT portion notch 28PT is preferably 50 μm or more, and the number of the ST portion notches 28ST in the straight tube portion 23 is preferably greater than the number of the PT portion notches 28PT in the proximal taper portion 22. Since the straight tube portion 23 is a portion of the balloon 20 that has a long length in the longitudinal axis direction x, the relatively large number of ST portion notches 28ST in the straight tube portion 23 makes it easier to ensure the stenosis portion expansion function by the ST portion notches 28ST when the balloon 20 is expanded. In addition, the relatively small number of PT portion notches 28PT in the proximal taper portion 22 improves the rigidity of the protruding portion 27 in the proximal taper portion 22, thereby improving the stenosis portion expansion function when the balloon 20 is deflated.

[0065] The number of PT portion notches 28PT in the proximal taper portion 22 may be the same as or different from the number of DT portion notches 28DT in the distal taper portion 24.

[0066] The number of ST portion notches 28ST in the straight pipe section 23 is preferably 1 or more, 3 or more, 5 or more, and 20 or less, 16 or less, 12 or less, or 8 or less. The number of DT portion notches 28DT in the distal tapered section 24 may be 1, and is preferably 2 or more, 3 or more, and 10 or less, 7 or less, or 5 or less. The number of PT portion notches 28PT in the proximal tapered section 22 may be 1, and is preferably 2 or more, 3 or more, and 10 or less, 7 or less, or 5 or less.

[0067] As shown in Fig. 4, the height H3 of the protrusion 27 in the straight pipe section 23 and the height H4 of the protrusion 27 in the distal taper section 24 preferably satisfy the relationship H3 ≥ H4. The height H3 of the protrusion 27 in the straight pipe section 23 and the height H4 of the protrusion 27 in the distal taper section 24 may be the same, i.e., H3 = H4, but it is preferable that the height H3 of the protrusion 27 in the straight pipe section 23 is higher than the height H4 of the protrusion 27 in the distal taper section 24, i.e., H3 > H4. This makes it easy to make the depth D3 of the ST section notch 28ST in the straight pipe section 23 deeper than the depth D4 of the DT section notch 28DT in the distal taper section 24. In addition, since the height H3 of the protrusion 27 in the straight pipe section 23 is relatively high, the protrusion segment 27S divided by the ST section notch 28ST can more easily act on the narrowed section.

[0068] As shown in FIG. 4, the height H3 of the protruding portion 27 of the straight pipe portion 23 is measured at a portion where the notch 28 (ST portion notch 28ST) is provided. The height H3 of the protruding portion 27 of the straight pipe portion 23 can be the distance between a point where a perpendicular line intersects with a virtual straight line connecting the two apexes 28t of the notch 28 (ST portion notch 28ST) toward the bottom 28b of the notch 28 (ST portion notch 28ST) in a cross section in the longitudinal axis direction x passing through the apex 27t of the protruding portion 27, and a point where the perpendicular line intersects with the base 27b of the protruding portion 27. The height H4 of the protruding portion 27 of the distal taper portion 24 is also measured at a portion where the notch 28 (DT portion notch 28DT) is provided. The height H4 of the protrusion 27 of the distal taper section 24 can be determined as the distance between a point where a perpendicular line intersects with an imaginary line connecting the two apexes 28t of the notch 28 (DT portion notch 28DT) toward the bottom 28b of the notch 28 (DT portion notch 28DT) in a cross section in the longitudinal axis direction x passing through the apex 27t of the protrusion 27 and a point where the perpendicular line intersects with the base 27b of the protrusion 27. Even if the protrusion 27 is provided in another portion, for example, the proximal taper section 22, the height of the protrusion 27 can be determined by a similar method as long as the notch 28 is provided.

[0069] For example, when a protrusion 27 is provided on the proximal sleeve portion 21, the distal sleeve portion 25, etc., and a notch 28 is not provided, the height of the protrusion 27 in these portions can be determined as the distance between the point at which a perpendicular line intersects with the top 27t of the protrusion 27 and the point at which the perpendicular line intersects with the base 27b of the protrusion 27, when a perpendicular line is drawn from a virtual straight line connecting the proximal end and distal end of the top 27t of the protrusion 27t in the proximal sleeve portion 21 in the case of the proximal sleeve portion 21, or a virtual straight line connecting the proximal end and distal end of the top 27t of the protrusion 27t in the distal sleeve portion 25 in the case of the distal sleeve portion 25. When the height of the protrusion 27 in each part is not constant along the longitudinal axis direction x, the average of the heights of the protrusions at three different points spaced apart in the longitudinal axis direction x, for example, the proximal end, midpoint, and distal end of each part, can be used as the height of the protrusion 27 of that part. When the perpendicular line does not intersect with the base 27b of the protrusion 27, as described below, the base 27b of the protrusion 27 can be extrapolated, and the point where the perpendicular line intersects with the extrapolated line 27be can be used as the reference for the height.

[0070] In Figure 4, the outer edge of protrusion 27 is formed linearly in a cross section in the longitudinal axis direction x passing through apex 27t of protrusion 27, but the shape of protrusion 27 is not limited to this, and the outer edge of protrusion 27, i.e., apex 27t, in a cross section in the longitudinal axis direction x passing through apex 27t of protrusion 27 may have any shape, such as a curved shape from the proximal end to the distal end of each part of straight tube section 23 and distal taper section 24, or a shape that combines straight lines and curves.

[0071] When a plurality of notches 28 are provided in the straight pipe section 23 or the distal taper section 24, the height of the protrusion 27 is measured at each portion where the notches 28 are provided, and the average of the heights is calculated. For example, when five ST section notches 28ST are provided in the straight pipe section 23, the height of the protrusion 27 is measured at five locations where the ST section notches 28ST are provided, and the average of the five heights obtained is set as the height H3 of the protrusion 27 of the straight pipe section 23. For example, when three DT section notches 28DT are provided in the distal taper section 24, the height of the protrusion 27 is measured at three locations where the DT section notches 28DT are provided, and the average of the three heights obtained is set as the height H4 of the protrusion 27 of the distal taper section 24. In the above example, the number of protrusions 27 provided in the straight pipe section 23 and the distal taper section 24 is five and three, respectively, but the number of protrusions 27 is not limited to these. In the case where the height of the protrusion 27 is not constant along the longitudinal axis direction x, as in the case of the distal taper portion 24, when a perpendicular line is drawn from a virtual line connecting the two apexes 28t of the notch 28 to the bottom 28b of the notch 28 to obtain the height of the protrusion 27, the perpendicular line may not intersect with the base 27b of the protrusion 27. In such a case, a virtual line connecting the proximal end and the distal end of the base 27b of the protrusion 27 in the distal taper portion 24 may be extrapolated, and the point where the perpendicular line intersects with the extrapolated line 27be may be used as the reference for the height. In the case of a portion other than the distal taper portion 24, when the perpendicular line does not intersect with the base 27b of the protrusion 27, the base 27b of the protrusion 27 may be extrapolated, and the point where the perpendicular line intersects with the extrapolated line 27be may be used as the reference for the height.

[0072] FIG. 4 shows an embodiment in which the height H4 of the protrusion 27 in the distal taper portion 24 becomes smaller toward the distal side along the longitudinal axis direction x, but the height H4 of the protrusion 27 in the distal taper portion 24 may be constant along the longitudinal axis direction x.

[0073] As shown in Figs. 3 to 5, the protrusion 27 in the distal taper section 24 preferably has a height that gradually decreases from the proximal side to the distal side in the longitudinal axis direction x. This makes it easy to improve the insertability of the balloon 20. In this case, when a plurality of DT section notches 28DT are provided in the protrusion 27 in the distal taper section 24, it is preferable that D4 is deeper on the proximal side and shallower on the distal side. This makes it easy to ensure the rigidity of the protrusion 27 in the distal taper section 24. In this case, it is also a preferred embodiment that an inner protrusion is formed in the distal taper section 24. This makes it possible to improve the rigidity of the distal side of the balloon 20 and to suppress kinking and overexpansion when pressurized.

[0074] 4, it is preferable that the height H3 of the protruding portion 27 in the straight pipe portion 23 and the height H2 of the protruding portion 27 in the proximal taper portion 22 satisfy the relationship H3 ≧ H2. The height H3 of the protruding portion 27 in the straight pipe portion 23 and the height H2 of the protruding portion 27 in the proximal taper portion 22 may be the same, i.e., H3 = H2, but it is preferable that the height H3 of the protruding portion 27 in the straight pipe portion 23 is higher than the height H2 of the protruding portion 27 in the proximal taper portion 22, i.e., H3 > H2. This makes it possible to keep the outer diameter of the balloon 20 in the proximal portion small, thereby improving the insertability of the balloon 20.

[0075] As shown in FIG. 4, FIG. 8, and FIG. 9, the protruding portion 27 in the proximal taper portion 22 preferably has a height that gradually decreases from the distal side to the proximal side in the longitudinal axis direction x. This makes it easier to improve the insertability of the balloon 20. In this case, when a plurality of PT portion notches 28PT are provided in the protruding portion 27 in the proximal taper portion 22, it is preferable that the depth D2 is deeper toward the distal side and shallower toward the proximal side. This makes it easier to ensure the rigidity of the protruding portion 27 in the proximal taper portion 22. In this case, it is also a preferred embodiment that an inner protruding portion is formed in the proximal taper portion 22. This makes it possible to further improve the rigidity of the proximal side of the balloon 20, and to suppress kinking and overexpansion when pressurized.

[0076] In the straight pipe section 23, the depth D3 of the ST portion notch and the height H3 of the protrusion 27 preferably satisfy the relationship D3 ≧ H3 × 1 / 4. This allows the ratio of the depth D3 of the ST portion notch 28ST to the height H3 of the protrusion 27 in the straight pipe section 23 to be a predetermined value or more, making it easier to improve the expansion function of the stenosis portion by the protrusion segment 27S acting on the stenosis portion.

[0077] In the distal tapered section 24, the depth D4 of the DT notch 28DT and the height H4 of the protrusion 27 preferably satisfy the relationship D4 ≧ H4 × 1 / 4. This allows the ratio of the depth D4 of the DT notch 28DT to the height H4 of the protrusion 27 in the distal tapered section 24 to be a predetermined value or more, so that the protrusion segments 27S separated by the DT notch 28DT can act on the vascular wall more easily when the balloon 20 is in a deflated state, making it easier to improve the expansion function of the stenosis area.

[0078] When the protruding portion 27 in the proximal taper portion 22 has a PT portion notch 28PT, the depth D2 of the PT portion notch 28PT is 50 μm or more, and the depth D2 of the PT portion notch 28PT and the height H2 of the protruding portion 27 in the proximal taper portion 22 preferably satisfy the relationship D2≧H2×1 / 4. This allows the ratio of the depth D2 of the PT portion notch 28PT to the height H2 of the protruding portion 27 in the proximal taper portion 22 to be a predetermined value or more, so that the protruding portion segments 27S divided by the PT portion notch 28PT can act on the vascular wall more easily, which makes it easier to improve the stenosis portion expansion function when the balloon 20 is deflated. The depth D2 of the PT portion notch 28PT is more preferably 70 μm or more, and even more preferably 100 μm or more. If the lower limit of the depth D2 of the PT portion notch 28PT is the above or more, the protruding portion 27 can be easily divided into a plurality of protruding portion segments 27S in the longitudinal axis direction x. Further, the depth D2 of the PT portion notch 28DT is preferably 400 μm or less, more preferably 300 μm or less, further preferably 200 μm or less, and particularly preferably 100 μm or less.

[0079] The balloon body 26 is preferably made of a resin, more preferably a thermoplastic resin. This makes it easy to manufacture the balloon 20 by molding. Examples of the resin that constitutes the balloon body 26 include polyolefin resins such as polyethylene, polypropylene, and ethylene-propylene copolymer, polyester resins such as polyethylene terephthalate and polyester elastomer, polyurethane resins such as polyurethane and polyurethane elastomer, polyphenylene sulfide resins, polyamide resins such as polyamide and polyamide elastomer, fluorine 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 10. For example, nylon 12 and nylon 11 are examples of polyamide resins that are suitable for the balloon 20, and nylon 12 is preferably used because it can be molded relatively easily during blow molding. Moreover, polyamide elastomers such as polyether ester amide elastomers and polyamide ether elastomers are preferably used from the viewpoints of thinning and flexibility of the balloon 20. Among them, polyether ester amide elastomers are preferably used from the viewpoints of high yield strength and good dimensional stability of the balloon 20.

[0080] The protrusion 27 can be made of, for example, a resin. When the protrusion 27 is made of a resin, it is preferable that the protrusion 27 and the balloon main body 26 are made of the same resin, and it is preferable that the protrusion 27 and the balloon main body 26 are integrally molded. That is, it is preferable that the protrusion 27 is not attached to the outer surface of the balloon main body 26, but that the thin part of the balloon 20 forms the balloon main body 26 and the thick part of the balloon 20 forms the protrusion 27. The balloon main body 26 may have an inner layer and an outer layer, and in this case, it is preferable that the protrusion 27 is made of the same resin as the outer layer of the balloon main body 26. With this configuration, it is difficult for the protrusion 27 to unintentionally fall off the balloon main body 26. Furthermore, or alternatively, the protrusion 27 and the balloon main body 26 may be made of different resins as long as the resin constituting the protrusion 27 and the resin constituting the balloon main body 26 have a certain degree of compatibility. The protrusion 27 may be attached to the outer surface of the balloon main body 26 as a separate member by means of welding, adhesion, or the like.

[0081] The protrusions 27 may be made of metal or a combination of metal and resin. The protrusions 27 may be attached to the outer surface of the balloon body 26 as separate members by welding, adhesion, or other means.

[0082] 2. Balloon Catheter The balloon catheter 10 according to the embodiment of the present invention includes the balloon for balloon catheter 20. As described in the above section "1. Balloon for balloon catheter", the balloon 20 is connected to the distal end of the shaft 30 as shown in FIG.

[0083] FIG. 1 shows a so-called rapid exchange type balloon catheter 10, which has a guidewire port 31a midway from the distal side to the proximal side of the shaft 30, and an inner shaft 31 that functions as a guidewire insertion passage from the guidewire port 31a to the distal side of the shaft 30.

[0084] It is preferable that the shaft 30 has a fluid flow path and a guide wire insertion path therein. For example, the shaft 30 may have an inner shaft 31 and an outer shaft 32 arranged outside the inner shaft 31, the inner shaft 31 functions as a guide wire insertion path, and the space between the outer shaft 32 and the inner shaft 31 functions as a fluid flow path. In such a configuration, it is preferable that the inner shaft 31 extends to the distal side so as to penetrate the balloon 2, the distal side of the balloon 20 is connected to the inner shaft 31, and the proximal side of the balloon 20 is connected to the outer shaft 32.

[0085] The balloon catheter 10 preferably has a distal outer shaft 32d and a proximal outer shaft 32p, and the distal outer shaft 32d and the proximal outer shaft 32p may be separate members, and the proximal end of the distal outer shaft 32d may be connected to the distal end of the proximal outer shaft 32p to form the outer shaft 32 extending from the balloon 20 to the proximal end of the balloon catheter 10. Alternatively, one outer shaft 32 may extend from the balloon 20 to the proximal end of the balloon catheter 10, and the distal outer shaft 32d and the proximal outer shaft 32p may be further formed of multiple tube members.

[0086] The shaft 30 is preferably made of a resin, a metal, or a combination of a resin and a metal. By using a resin as the material for the shaft, it becomes easier to impart flexibility and elasticity to the shaft 30. In addition, by using a metal as the material for the shaft 30, the deliverability of the balloon catheter 1 can be improved.

[0087] Examples of resins constituting the shaft 30 include polyamide resins, polyester resins, polyurethane resins, polyolefin resins, fluorine resins, vinyl chloride resins, silicone resins, natural rubber, synthetic rubber, and the like. These may be used alone or in combination of two or more. Examples of metals constituting the shaft 30 include stainless steel such as SUS304 and SUS316, platinum, nickel, cobalt, chromium, titanium, tungsten, gold, Ni-Ti alloys, Co-Cr alloys, or combinations thereof. When the shaft 30 includes a distal outer shaft 32d and a proximal outer shaft 32p that are separate members, for example, the distal outer shaft 32d may be made of a resin, and the proximal outer shaft 32p may be made of a metal. The shaft 30 may also have a laminated structure made of different materials or the same materials.

[0088] The balloon 20 and the shaft 30 can be joined by bonding with an adhesive, welding, attaching a ring-shaped member to the overlapping portion of the end of the balloon 20 and the shaft 30 and crimping the end, etc. Among these, it is preferable that the balloon 20 and the shaft 30 are joined by welding. By welding the balloon 20 and the shaft 30, the bond between the balloon 20 and the shaft 30 is not easily released even when the balloon 20 is repeatedly expanded or contracted, and the bond strength can be improved.

[0089] A tip member 60 is preferably provided at the distal end of the balloon catheter 10. The tip member 60 may be provided at the distal end of the balloon catheter 10 as a member separate from the inner shaft 31 and connected to the distal end of the balloon 20, or the inner shaft 31 extending distally beyond the distal end of the balloon 20 may function as the tip member 60.

[0090] In order to make it possible to confirm the position of the balloon 20 under X-ray fluoroscopy, a radiopaque marker 70 may be disposed on the shaft 30 at a portion where the balloon 20 is located in the longitudinal axis direction x. The radiopaque marker 70 may be disposed, for example, on the inner shaft 31 disposed inside the balloon 20, and is preferably disposed at positions corresponding to both ends of the straight tube portion 23 of the balloon 20, or may be disposed at a position corresponding to the center of the straight tube portion 23 of the balloon 20.

[0091] A hub 40 may be provided on the proximal side of the shaft 30, and the hub 40 is preferably provided with a fluid injection portion 50 that communicates with a flow path for supplying fluid to the inside of the balloon 20.

[0092] The shaft 30 and the hub 40 can be joined by, for example, bonding with an adhesive, welding, etc. Among these, it is preferable that the shaft 30 and the hub 40 are joined by adhesion. By bonding the shaft 30 and the hub 40, the bond strength between the shaft 30 and the hub 40 can be increased and the durability of the balloon catheter 10 can be improved when the shaft 30 and the hub 40 are made of different materials, for example, when the shaft 30 is made of a highly flexible material and the hub 40 is made of a highly rigid material.

[0093] Although not shown, the present invention can also be applied to a so-called over-the-wire type balloon catheter having a guidewire passage from the distal side to the proximal side of the shaft. In the case of the over-the-wire type, it is preferable that the inflation lumen and the guidewire lumen extend to a hub located on the proximal side, and the proximal openings of each lumen are provided in a bifurcated hub.

[0094] In the case of a rapid exchange type catheter, it is preferable that the outer wall of the distal outer shaft 32d and / or the proximal outer shaft 32p is appropriately coated, and it is more preferable that both the distal outer shaft 32d and the proximal outer shaft 32p are coated. In the case of an over-the-wire type catheter, it is preferable that the outer wall of the outer shaft is appropriately coated.

[0095] The coating can be a hydrophilic coating or a hydrophobic coating depending on the purpose, and can be applied by immersing the shaft 30 in a hydrophilic coating agent or a hydrophobic coating agent, applying a hydrophilic coating agent or a hydrophobic coating agent to the outer wall of the shaft 30, or covering the outer wall of the shaft 30 with a hydrophilic coating agent or a hydrophobic coating agent. The coating agent may contain a drug or an additive.

[0096] Examples of hydrophilic coating agents include hydrophilic coating agents made of hydrophilic polymers such as polyvinyl alcohol, polyethylene glycol, polyacrylamide, polyvinylpyrrolidone, methyl vinyl ether maleic anhydride copolymer, or any combination thereof.

[0097] Examples of hydrophobic coating agents include polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP), perfluoroalkoxyalkane (PFA), silicone oil, hydrophobic urethane resin, carbon coat, diamond coat, diamond-like carbon (DLC) coat, ceramic coat, and substances with low surface free energy terminated with alkyl groups or perfluoroalkyl groups.

[0098] A drug may be retained on the outer surface of the straight tube portion 23 of the balloon 20. The drug is not particularly limited as long as it is a pharmacologically active substance, and examples of the drug include drugs that are acceptable as medicines, such as gene therapy drugs, non-gene therapy drugs, small molecules, and cells. In particular, when the catheter is used for the purpose of suppressing restenosis of blood vessels after treatment in angioplasty, anti-restenosis drugs such as antiproliferative drugs and immunosuppressants can be preferably used as the drug. Examples of such drugs include paclitaxel, sirolimus (rapamycin), everolimus, and zotarolimus. [Explanation of symbols]

[0099] 10: Balloon catheter 20: Balloon for balloon catheter 21: Proximal sleeve part 22: Proximal taper 23: Straight pipe section 24: Distal tapered section 25: Distal sleeve part 26: Balloon body 27:Protrusion 27b: Base of protrusion 27t: Top of protrusion 27S: protruding segment 28:Notch 28b: Bottom of the notch 28t: Top of notch 28PT: PT section notch 28ST: ST section notch 28PS: PS section notch 29: Feather 29a: Wing forming section 30: Shaft 31: Inner shaft 31a: Guidewire port 32: Outer shaft 32d: Distal outer shaft 32p: Proximal outer shaft 40: Hub 50:Fluid injection part 60: Tip member 70: Marker D2: Depth of the proximal taper notch D3: Depth of the notch in the straight pipe D4: Depth of the notch in the distal taper H2: Height of proximal taper protrusion H3: Height of protruding part of straight pipe H4: Height of the protruding part of the distal taper

Claims

1. 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, a balloon body having an outer surface and an inner surface; The balloon body has a protrusion on the outer surface thereof, the protrusion protruding radially outward and extending in the longitudinal axis direction, The protrusion at the straight tube section has an ST section notch, and the protrusion at the distal tapered section has a DT section notch, The depth D3 of the ST portion notch and the depth D4 of the DT portion notch are both 50 μm or more, A balloon for a balloon catheter, wherein the depth D3 of the ST portion notch and the depth D4 of the DT portion notch satisfy the relationship D3>D4.

2. 2. The balloon for a balloon catheter according to claim 1, wherein the ST portion notch is a plurality of ST portion notches, and the depth D3 is an average of the depths of the plurality of ST portion notches.

3. 2. The balloon for a balloon catheter according to claim 1, wherein the DT notch is a plurality of DT notches, and the depth D4 is an average of the depths of the plurality of DT notches.

4. 2. The balloon for a balloon catheter according to claim 1, wherein a height H3 of the protrusion at the straight tube portion and a height H4 of the protrusion at the distal tapered portion satisfy a relationship of H3 ≧ H4.

5. 2. The balloon for a balloon catheter according to claim 1, wherein the protruding portion in the proximal taper portion has a PT portion notch, the depth D2 of the PT portion notch is 50 μm or more, and the depth D3 of the ST portion notch and the depth D2 of the PT portion notch satisfy the relationship D3 < D2.

6. 6. The balloon for a balloon catheter according to claim 5, wherein the PT portion notch is a plurality of PT portion notches, and the depth D2 is an average of the depths of the plurality of PT portion notches.

7. 2. The balloon for a balloon catheter according to claim 1, wherein a height H3 of the protruding portion at the straight tube portion and a height H2 of the protruding portion at the proximal taper portion satisfy a relationship of H3 ≧ H2.

8. 2. The balloon for a balloon catheter according to claim 1, wherein a depth D3 of the ST portion notch and a height H3 of the protrusion in the straight tube portion satisfy a relationship of D3 ≥ H3 × 1 / 4.

9. 2. The balloon for a balloon catheter according to claim 1, wherein a depth D4 of the DT portion notch and a height H4 of the protrusion in the distal taper portion satisfy a relationship of D4 ≧ H4 × 1 / 4.

10. 2. The balloon for a balloon catheter according to claim 1, wherein the protruding portion in the proximal taper portion has a PT portion notch, the depth D2 of the PT portion notch is 50 μm or more, and the depth D2 of the PT portion notch and the height H2 of the protruding portion in the proximal taper portion satisfy the relationship D2 ≧ H2 × 1 / 4.

11. 2. The balloon for a balloon catheter according to claim 1, wherein the number of the ST portion notches is greater than the number of the DT portion notches.

12. 2. The balloon for a balloon catheter according to claim 1, wherein the protruding portion in the proximal taper portion has a PT portion notch, the depth D2 of the PT portion notch is 50 μm or more, and the number of the ST portion notches is greater than the number of the PT portion notches.

13. A balloon catheter comprising the balloon for a balloon catheter according to any one of claims 1 to 12.

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