Balloon catheter balloon

Abstract

A balloon catheter for easy insertion into a body cavity, with good pushability and the ability to easily cut stenosis is provided. The balloon catheter balloon (1) has a balloon body (20) with a protrusion (60) that protrudes radially outward from the outer surface at the straight tube portion (23) and the proximal conical portion (22) and extends in the long axis direction x. The ratio of the height H1 of the protrusion (60) at the straight tube portion (23) to the width W1 of the protrusion (60) is W1 / H1, which is greater than the ratio of the height H2 of the protrusion (60) at the proximal conical portion (22) to the width W2 of the protrusion (60) is W2 / H2.

Description

Technical Field

[0001] This invention relates to balloons for balloon catheters. Background Technology

[0002] Angina pectoris, myocardial infarction, and other diseases can occur due to the formation of narrowed sections in the inner wall of blood vessels caused by calcification and other hardening. As one treatment option, angioplasty is a procedure that uses a balloon catheter to dilate the narrowed section. Angioplasty is a low-invasive treatment that does not require open-chest surgery like bypass surgery and is widely performed.

[0003] In angiogenesis surgery, conventional balloon catheters sometimes fail to dilate stenotic lesions hardened by calcification or other factors. Alternatively, methods using indwelling dilators called stents can be employed to dilate the stenosis; however, this treatment can also lead to in-stent-restenosis (ISR) lesions, characterized by excessive neointimal proliferation and subsequent re-stenosis. In ISR lesions, the neointimal layer is soft and prone to slippage, making it easy for the balloon to shift from the lesion during dilation, potentially damaging the vessel.

[0004] As a balloon catheter capable of dilating stenosis even in calcified lesions and ISR lesions, balloon catheters have been developed that incorporate protrusions or braided layers or scoring elements in the balloon for biting into the stenosis. For example, Patent Document 1 discloses a balloon catheter in which the protrusion of the protrusion located at the anterior lateral cone is greater than the protrusion of the protrusion located at the straight tube. Furthermore, Patent Document 2 discloses a balloon catheter in which the dilation element connected to the outer surface of the balloon via a connector has a first effective width and a second effective width, wherein the first effective width is less than the second effective width.

[0005] Patent Document 1: International Publication No. 2020 / 012850

[0006] Patent Document 2: Japanese Patent Publication No. 2011-513031

[0007] The balloon catheter, in its constricted state, is inserted into the body cavity and delivered to the treatment site within the cavity. During delivery, balloon delivery is controlled by transmitting manipulation from the hand side to the tip containing the balloon. This facilitates insertion within the body cavity and allows for easy transmission of manipulation from the hand side to the tip (high pushability), thereby improving treatment safety, shortening treatment time, and enabling less burdensome treatment for the patient. Furthermore, after the balloon is delivered to the treatment site, efficient and easy incision of the stenosis is required. However, existing balloon catheters have room for improvement in terms of ease of insertion within the body cavity, pushability, and ease of incision of the stenosis. Summary of the Invention

[0008] In view of the above, the object of the present invention is to provide a balloon catheter that is easy to insert into a body cavity, has good pushability, and can easily cut through stenosis.

[0009] One embodiment of the balloon catheter balloon of the present invention, which solves the above-mentioned problems, includes a balloon body having an outer surface and an inner surface, having: a long axis direction, a radial direction, and a circumferential direction; the radial direction is the direction connecting the centroid of a shape that outlines the shape of the balloon body in its expanded state to a point on the outer surface in a cross-section perpendicular to the long axis direction; the circumferential direction is the direction along the outer periphery of the balloon body in its expanded state in a cross-section perpendicular to the radial direction. The balloon body has: a straight tube portion; a proximal cone portion located closer to the side than the straight tube portion; and a distal cone portion located more distal to the side than the straight tube portion. The balloon body has protrusions in the straight tube portion and the proximal cone portion, which protrude radially outward from the outer surface of the balloon body and extend in the long axis direction. The ratio of the height H1 of the protrusion to the width W1 of the protrusion at the straight tube portion, W1 / H1, is greater than the ratio of the height H2 of the protrusion to the width W2 of the protrusion at the proximal cone portion, W2 / H2.

[0010] (Here, the height and width of the protrusion are defined as follows.)

[0011] In the radial section, the circumcircle C of the balloon body b The radius and the circumcircle C b The circumcircle C of the common center protrusion p The difference in radius is taken as the height of the protrusion.

[0012] In the radial section, with the circumcircle C b The width of the protrusion is defined as the maximum length of the arc within the inner contour of the protrusion of the concentric circles sharing a common center.

[0013] Preferably, the width W1 of the protrusion at the straight tube section is wider than the width W2 of the protrusion at the proximal conical section.

[0014] The preferred ratio W1 / H1 at the straight pipe section is 0.2 or higher and 5 or lower.

[0015] Preferably, the ratio W2 / H2 at the proximal lateral cone is 0.2 or higher and 5 or lower.

[0016] Preferably, in the radial cross-section, the protrusion of the straight tube section has a front end portion, and the width W of the front end portion of the protrusion is... T The ratio W to the width W1 of the protrusion T / W1 is below 0.5.

[0017] (Here, the width of the front end of the protrusion is defined as follows.)

[0018] In the radial section, with the circumcircle C p Concentric circles with a common center and a circumcircle C p The width of the front end is defined as the length of the arc inside the contour of the protruding part, which is 95% of the radius of the circle.

[0019] The height H1 of the protrusion of the preferred straight pipe section is at least 0.1 mm.

[0020] Preferably, in the radial section, the protrusion of the straight tube section has a front end with an angle of 135° or less.

[0021] Preferably, the protrusions of the straight tube section and the protrusions of the proximal side cone section extend continuously in the long axis direction.

[0022] Preferably, the distal conical portion has a protrusion, and the height H3 of the protrusion of the distal conical portion is lower than the height H1 of the protrusion of the straight tube portion. In this case, it is preferable that the protrusion of the straight tube portion and the protrusion of the distal conical portion extend continuously in the long axis direction.

[0023] Preferably, the distal cone has a medial protrusion that protrudes radially inward from the inner surface of the balloon body and extends along its long axis. In this case, the distal cone preferably has a protrusion, and the protrusion of the distal cone and the medial protrusion are positioned at the same location in the circumferential direction.

[0024] The preferred protrusion is made of the same material as the balloon body.

[0025] According to the above-mentioned balloon catheter, the ratio of the height H1 of the protrusion at the straight section to the width W1 of the protrusion, W1 / H1, is greater than the ratio of the height H2 of the protrusion at the proximal lateral cone section to the width W2 of the protrusion, W2 / H2. Therefore, it is possible to form a balloon catheter that is easy to insert into the body cavity, has good pushability, and can easily cut through the stenosis. Attached Figure Description

[0026] Figure 1 This is a side view of a balloon catheter according to one embodiment of the present invention.

[0027] Figure 2 express Figure 1 The cross-sectional view along the long axis of the balloon catheter in its expanded state.

[0028] Figure 3 express Figure 1 Sectional view III-III.

[0029] Figure 4 express Figure 1 Sectional view IV-IV.

[0030] Figure 5 This is a radial cross-sectional view of a straight tube portion according to another embodiment of the present invention.

[0031] Figure 6 This is a radial cross-sectional view of the straight tube portion according to yet another embodiment of the present invention.

[0032] Figure 7 This is a radial cross-sectional view of the proximal side cone according to another embodiment of the present invention.

[0033] Figure 8 This is a radial cross-sectional view of the proximal side cone according to yet another embodiment of the present invention.

[0034] Figure 9 This is a radial cross-sectional view of the proximal side cone according to yet another embodiment of the present invention.

[0035] Figure 10 Indicates in Figure 5 The diagram illustrates the front end of the protrusion in the shown form.

[0036] Figure 11 This is a top view of a balloon according to one embodiment of the present invention, viewed from the protruding side.

[0037] Figure 12 This is a radial cross-sectional view of the distal side cone according to one embodiment of the present invention.

[0038] Figure 13 This is a radial cross-sectional view of the distal side cone according to another embodiment of the present invention.

[0039] Figure 14 This is a perspective view of the preform before expansion according to one embodiment of the present invention. Detailed Implementation

[0040] The present invention will now be specifically described based on embodiments. However, the present invention is not limited to these embodiments, and it is undoubtedly possible to implement it by appropriate modifications within the scope of the preceding / following descriptions, all of which are included within the technical scope of the present invention. Furthermore, in the various figures, for convenience, there are instances where shaded lines, component reference numerals, etc., are omitted. In such cases, please refer to the specification and other figures. Additionally, the dimensions of various components in the figures are primarily advantageous for understanding the features of the present invention, and therefore may differ from actual dimensions. Furthermore, in this specification, the balloon catheter is sometimes simply referred to as a balloon.

[0041] The balloon catheter of the present invention comprises a balloon body having an outer surface and an inner surface, and having a long axis direction, a radial direction, and a circumferential direction. The radial direction is the direction connecting the centroid of a shape that outlines the shape of the balloon body in its expanded state to a point on the outer surface in a cross-section perpendicular to the long axis direction. The circumferential direction is the direction along the outer periphery of the balloon body in its expanded state in a cross-section of the radial direction. The balloon body has: a straight tube portion; a proximal cone portion located closer to the side than the straight tube portion; and a distal cone portion located distal to the side than the straight tube portion. The balloon body has protrusions in the straight tube portion and the proximal cone portion. These protrusions protrude radially outward from the outer surface of the balloon body and extend in the long axis direction. The ratio of the height H1 to the width W1 of the protrusion at the straight tube portion, W1 / H1, is greater than the ratio of the height H2 to the width W2 of the protrusion at the proximal cone portion, W2 / H2. Here, the height and width of the protrusions are defined as follows.

[0042] In the radial section, the circumcircle C of the balloon body b The radius and the circumcircle C b The circumcircle C of the common center protrusion p The difference in radius is taken as the height of the protrusion.

[0043] In the radial section, with the circumcircle C b The width of the protrusion is the maximum length of the arc inside the contour of the protrusion within the circumference of the concentric circles that share a common center.

[0044] The ratio of the height H1 to the width W1 of the protrusion at the straight tube portion (W1 / H1) is greater than the ratio of the height H2 to the width W2 of the protrusion at the proximal lateral cone portion (W2 / H2), thus enabling the formation of a balloon that can be efficiently incised during expansion. This is believed to be because satisfying the above relationship allows the width W1 of the protrusion at the straight tube portion to be relatively large compared to its height H1, thereby widening the area to be incised through the protrusion in the circumferential z-direction and increasing the expansion force during incision. Furthermore, the relatively large ratio of the height H1 to the width W1 of the protrusion at the straight tube portion (W1 / H1), i.e., the relatively small ratio of the height H1 to the width W1, allows for a relatively small outer diameter of the balloon during contraction, facilitating balloon insertion into the body cavity. Additionally, the reduced rigidity of the balloon makes contraction easier, thus shortening the retraction time. This enables shorter treatment times in cases of multiple expansions, shorter times for removing the inflated and contracted balloon, or for transporting it to other lesions, resulting in safer treatment with less burden on the patient.

[0045] Furthermore, the ratio of the height H1 to the width W1 of the protrusion at the straight tube is greater than the ratio W1 / H1 of the height H2 to the width W2 of the protrusion at the proximal conical section, i.e., the ratio W2 / H2 of the height H2 to the width W2 of the protrusion at the proximal conical section is relatively smaller. This allows the height H2 of the protrusion at the proximal conical section to be relatively larger than its width W2. Consequently, the bending rigidity of the proximal conical section is greater than that of the straight tube, resulting in a balloon with good delivery capability. Additionally, the ratio W2 / H2 of the height H2 of the protrusion at the proximal conical section is relatively smaller, i.e., the width W2 of the protrusion is relatively smaller than its height H2. This narrows the area that would be a three-dimensional obstacle when inserting the balloon into the body cavity in the circumferential direction, making balloon insertion into the body cavity easier.

[0046] Thus, the balloon of the present invention can reduce the bending stiffness in the long axis direction from the proximal side to the distal side of the balloon, thereby enabling the balloon to have the best balance of bending stiffness as a whole, good pushability, and good resistance to kinking and insertion.

[0047] Reference Figures 1 to 14 Instructions are provided regarding the use of balloon catheters. Figure 1 This is a side view of a balloon catheter according to one embodiment of the present invention. Figure 2 express Figure 1 The cross-sectional view along the long axis of the balloon catheter in its expanded state. Figure 3 express Figure 1 Sectional view III-III, Figure 4 express Figure 1 Sectional view IV-IV. Figure 5 This is a radial cross-sectional view of the straight tube portion according to another embodiment of the present invention. Figure 6 This is a radial cross-sectional view of the straight tube portion according to yet another embodiment of the present invention. Figures 7-9 This is a radial cross-sectional view showing the proximal cone portion involved in various embodiments of the present invention. Figure 10 Indicates in Figure 5 The diagram illustrates the front end of the protrusion in the shown configuration. Figures 5-10 In order to make the description of the height and width of the protrusion easier to understand, the description of the inner tube and the shaded line have been omitted. Figure 11 This is a top view of a balloon according to one embodiment of the present invention, viewed from the protruding side. Figure 12 This is a radial cross-sectional view showing the distal side cone portion according to one embodiment of the present invention. Figure 13 This is a radial cross-sectional view of the distal side cone according to another embodiment of the present invention. Figure 14 This is a perspective view of the preform before expansion according to one embodiment of the present invention.

[0048] In this invention, the proximal side refers to the direction relative to the extension direction of the balloon catheter 1 or the long axis direction x of the axis 3, which is the direction of the user's or surgeon's hand. The distal side refers to the opposite direction of the proximal side, that is, the direction of the object being treated. Even components other than the long strip-shaped component such as the axis 3 have the same long axis direction x as the axis 3.

[0049] like Figure 1 and Figure 2 As shown, the balloon catheter 1 has: a shaft 3; and a balloon 2 for the balloon catheter, disposed outside the shaft 3. The balloon catheter 1 has a distal side and a proximal side, with the balloon 2 disposed distally on the shaft 3. The balloon catheter 1 is configured to supply fluid to the interior of the balloon 2 via the shaft 3, and the expansion and contraction of the balloon 2 can be controlled using an inflator (balloon pressurizer). The fluid can also be a pressurized fluid pressurized by a pump or the like.

[0050] Preferably, the shaft 3 has a fluid flow path internally and a guidewire insertion path. To form a structure in which the shaft 3 has both a fluid flow path and a guidewire insertion path internally, an example can be formed as follows: the shaft 3 has an outer tube 31 and an inner tube 32, the inner tube 32 functions as the guidewire insertion path, and the space between the inner tube 32 and the outer tube 31 functions as a fluid flow path. Thus, in the case of the shaft 3 having an outer tube 31 and an inner tube 32, preferably the inner tube 32 extends from the distal end of the outer tube 31 and protrudes to a position distal to the balloon 2, the distal side of the balloon 2 engages with the inner tube 32, and the proximal side of the balloon 2 engages with the outer tube 31.

[0051] like Figure 1 and Figure 2 As shown, the balloon 2 has a balloon body 20 having an outer surface and an inner surface, and has a major axis direction x, a radial direction y and a circumferential direction z. The radial direction y is the direction connecting the centroid of the shape of the balloon body 20 in its expanded state to a point on the outer surface in a cross section perpendicular to the major axis direction x. The circumferential direction z is the direction along the outer periphery of the balloon body 20 in its expanded state in a cross section of the radial direction y.

[0052] The balloon body 20 has: a straight tube portion 23; a proximal conical portion 22 located closer to the straight tube portion 23; and a distal conical portion 24 located distal to the straight tube portion 23. Preferably, the straight tube portion 23 has approximately the same diameter in the long axis direction x, and preferably the proximal conical portion 22 and the distal conical portion 24 are formed to narrow as they move away from the straight tube portion 23. The straight tube portion 23 has the largest diameter, so that when the balloon 2 is dilated in a lesion such as a stenosis, the straight tube portion 23 can make sufficient contact with the lesion, facilitating the dilation or incision of the lesion. In addition, by having the narrowed proximal conical portion 22 and the distal conical portion 24, the outer diameter of the proximal and distal ends of the balloon 2 can be reduced when the balloon 2 is contracted, thereby reducing the step difference between the axis 3 and the balloon 2, and thus facilitating the insertion of the balloon 2 into the body cavity.

[0053] The balloon 2 may also have a non-expanding proximal sleeve portion 21 and a distal sleeve portion 25 at positions closer to the proximal side cone portion 22 and distal to the distal side cone portion 24, respectively. It is possible to form a structure in which at least a portion of the proximal sleeve portion 21 and the distal sleeve portion 25 is fixed to the shaft 3. When the shaft 3 has an outer tube 31 and an inner tube 32, it is possible to form a structure in which at least a portion of the proximal sleeve portion 21 is fixed to the outer tube 31 and at least a portion of the distal sleeve portion 25 is fixed to the inner tube 32.

[0054] like Figures 2-4 As shown, the balloon body 20 has protrusions 60 at the straight tube portion 23 and the proximal conical portion 22. These protrusions 60 project outwards radially y from the outer surface of the balloon body 20 and extend along the major axis direction x. The maximum length of the protrusion 60 projecting outwards radially y from the outer surface of the balloon body 20 in a cross-section of the radial y direction is preferably at least 1.2 times the membrane thickness of the balloon body 20, more preferably at least 1.5 times, and even more preferably at least 2 times. However, lengths of less than 100 times, 50 times, 30 times, or 10 times are also permissible. Furthermore, this maximum length may vary along the major axis direction x. With a protrusion 60 having a maximum length within the aforementioned range, it is easier to form an incision of appropriate depth in the narrow portion, making incision easier. Moreover, by having the protrusion 60 in the balloon body 20, the strength of the balloon 2 can be improved, and excessive expansion of the balloon 2 during inflation can be suppressed.

[0055] like Figure 1 and Figure 2 As shown, the balloon body 20 may also have a structure in which the protrusion 60 located on the proximal conical portion 22 extends to the proximal sleeve portion 21, and the proximal sleeve portion 21 also has a protrusion 60. Alternatively, although not shown, the balloon body 20 may also have a structure in which the proximal sleeve portion 21 does not have a protrusion 60.

[0056] Regarding the number of protrusions 60 on the circumferential z-axis, it can be as follows: Figure 3 and Figure 4 The image shows multiple examples, or you can refer to... Figures 5-9 One example is shown. When multiple protrusions 60 are provided in the circumferential direction z, the multiple protrusions 60 are preferably separated in the circumferential direction z, and more preferably arranged at equal intervals in the circumferential direction z. Preferably, the separation distance is longer than the maximum circumference of the protrusions 60. By separating the protrusions 60 in the circumferential direction z, and preferably arranging them at equal intervals, it becomes easier to fix the balloon 2 and cut the narrow portion.

[0057] The protrusion 60 extending along the long axis x on the outer surface of the balloon body 20 can be positioned at the same location in the circumferential direction z as in the long axis x direction, i.e. Figure 2 The protrusion 60 is arranged vertically along the long axis x. If the protrusion 60 is arranged vertically, it can cut through the narrow portion vertically. Alternatively, although not shown, the protrusion 60 can also be arranged at different positions in the long axis x and circumferential z, for example, in a spiral shape that surrounds the outer surface of the balloon body 20 in the circumferential z. If the protrusion 60 is like this, it can cut through the narrow portion obliquely.

[0058] The ratio W1 / H1 of the height H1 of the protrusion 60 in the straight tube 23 to the width W1 of the protrusion 60 is greater than the ratio W2 / H2 of the height H2 of the protrusion 60 in the proximal conical section 22. Here, in the radial y-section, the circumcircle C of the balloon body 20... b radius r b With the same circumcircle C b The circumcircle C of the protrusion 60 of the common center O p radius r p The difference, as the height of the protrusion 60, will be in the radial y section, and intersect with the circumcircle C. b Concentric circles C sharing a common center O c The maximum length of the arc inside the outline of the protrusion 60 within the circumference is taken as the width of the protrusion 60.

[0059] Reference Figures 5-9 The definition of the height of the protrusion 60 is explained. Figure 5 This is a radial y-sectional view of the straight tube portion 23 of the balloon 2 according to one embodiment. Figure 5 In the shape shown, the outer periphery of the balloon body 20 is circular, therefore the circumscribed circle C b Consistent with the outer periphery of the balloon body 20. Aligned with the circumcircle C. b The circumcircle C of the protrusion 60 of the common center O p The circumcircle C is uniquely determined, therefore it can be found by circumscribing the circumcircle C. p radius r pWith circumcircle C b radius r b The difference is such that the height H1 of the protrusion 60 at the straight pipe section 23 can be obtained.

[0060] Figure 6 This is a radial y-sectional view at the proximal conical portion 22 of the balloon 2 according to another embodiment. Figure 6 In the configuration shown, the membrane thickness of the balloon body 20, where the protrusion 60 is arranged in the circumferential direction z, becomes thicker. As a result, the outer periphery of the balloon body 20 becomes a roughly elliptical shape that extends only in the direction of the protrusion 60, deviating from a circular shape. Therefore, the circumcircle C... b Unlike the outer periphery of the balloon body 20. Even in this case, it differs from the circumcircle C. b The circumcircle C of the protrusion 60 of the common center O p It is also uniquely determined, therefore, by finding the circumcircle C p radius r p With circumcircle C b radius r b The difference allows us to obtain the height H1 of the protrusion 60 at the straight pipe section 23. For example... Figure 6 As shown, the outer periphery of the balloon body 20 may deviate from a circular shape due to the difference in membrane thickness in the radial y section along the circumferential z direction. Alternatively, although not shown, the outer periphery of the balloon body 20 may also deviate from a circular shape because although the membrane thickness of the balloon body 20 is the same in the radial y section along the circumferential z direction, the cross-sectional shape of the balloon body 20 itself deviates from a circular shape.

[0061] Figure 7 This is a radial y-sectional view at the proximal conical portion 22 of the balloon 2 according to one embodiment. Figure 7 In the shape shown, the outer periphery of the balloon body 20 is circular, therefore the circumscribed circle C b Consistent with the outer periphery of the balloon body 20. Aligned with the circumcircle C. b The circumcircle C of the protrusion 60 of the common center O p The circumcircle C is uniquely determined, therefore it can be found by circumscribing the circumcircle C. p radius r p With circumcircle C b radius r b The difference allows for the determination of the height H2 of the protrusion 60 at the proximal side cone 22. Although not shown in the figure, it can be seen in the description of the straight tube 23 above. Figure 6 As described above, even if the outer periphery of the balloon body 20 deviates from a circular shape, the circumscribed circle C b and circumcircle C p It is also uniquely determined, therefore, by finding the circumcircle C p radius r p With circumcircle C b radius rb The difference allows us to obtain the height H2 of the protrusion 60 at the proximal lateral cone 22.

[0062] Figure 8 and Figure 9 These are radial y-sectional views of the proximal conical portion 22 of the balloon 2 according to another embodiment. Figure 8 and Figure 9 In the configuration shown, the cross-sectional shape of the protrusion 60 in the radial y-section is similar to... Figure 7 The cross-sectional shapes shown are different, but even in this case, the circumcircle C b and circumcircle C p It is also uniquely determined, therefore, by finding the circumcircle C p radius r p With circumcircle C b radius r b The difference allows us to obtain the height H2 of the protrusion 60 at the proximal lateral cone 22.

[0063] Next, refer to Figures 5-9 The definition of the width of the protrusion 60 is explained. For example... Figure 5 As shown, in the radial y-section of the straight tube section 23, it is parallel to the circumscribed circle C. b Concentric circles C sharing a common center O c The maximum length of the arc within the circumference of the protrusion 60 is equal to the width of the protrusion 60. Although related to the circumscribed circle C... b Concentric circles C sharing a common center O c Infinitely many, but a portion of their circumference exists within concentric circles C inside the contour of protrusion 60. c It is finite. And among them, the largest concentric circle C that can determine the length of at least one arc existing inside the contour of the protrusion 60 is... c The length of the arc can be calculated as the width W1 of the protrusion 60 of the straight tube 23. Figure 5 In the configuration shown, the maximum width is at the base end of the protrusion 60 closest to the center O, and the longest concentric circle C, existing on the inner side of the outline of the protrusion 60, is... c Circumcircle C of balloon body 20 b Consistent.

[0064] exist Figure 6 In the shape shown, the width is also the largest on the base end side of the protrusion 60 closest to the center O, and therefore the concentric circle C with the largest length of the arc existing inside the outline of the protrusion 60 is also the largest. c Circumcircle C of balloon body 20 bConsistent. Even in cases other than those not illustrated, even when the protrusion 60 has its maximum width excluding the base side, it is possible to determine at least one aspect with respect to the circumscribed circle C. b The concentric circles C that share a center O and exist inside the contour of the protrusion 60 are the longest concentric circles. c Therefore, the width W1 of the protrusion 60 at the straight pipe section 23 can be obtained.

[0065] The width W2 of the protrusion 60 at the proximal conical portion 22 can also be obtained in the same way as the width W1 of the protrusion 60 at the straight tube portion 23. For Figure 7 and Figure 8 In terms of the shape shown, although the cross-sectional shapes of the protrusions 60 in the radial y section are different, they can be compared with... Figure 5 The same applies to the case of the straight tube section 23 shown, where the width W2 of the protrusion 60 is also obtained. Figure 7 and Figure 8 In the configuration shown, the protrusion 60 has its maximum width on the base end side closest to the center O, and... Figure 5 Similarly, the concentric circle C with the longest arc existing inside the contour of the protrusion 60 is... c Circumcircle C of balloon body 20 b Consistent.

[0066] Figure 9 The shape shown is an example of the case where the protrusion 60 has its maximum width, excluding the base end side. In this case, the concentric circle C, which has the longest arc length, exists inside the contour of the protrusion 60. c Circumcircle C of balloon body 20 b Different, but capable of determining the length of at least one concentric circle C, which is the largest concentric circle existing inside the contour of the protrusion 60. c Therefore, the width W2 of the protrusion 60 can be obtained.

[0067] The shape of the radial section b of the protrusion 60 can be any shape, for example, it can be as follows: Figures 3-7 The approximate triangle shown can also be as follows: Figure 8 and Figure 9 The shape shown is approximately pentagonal, but it can also be polygonal, sector-shaped, wedge-shaped, convex, spindle-shaped, circular, etc. Regardless of the shape of the protrusion 60 in the radial y-section, the height and width of the protrusion 60 can be determined by the above definition.

[0068] As determined above, the ratio of the height H1 to the width W1 of the protrusion 60 at the straight tube 23 is larger than the ratio of the height H2 to the width W2 of the protrusion 60 at the proximal lateral cone 22. This allows the width W1 of the protrusion at the straight tube 23 to be relatively larger than its height H1, thereby widening the area cut by the protrusion 60 in the circumferential z direction. Consequently, a balloon capable of efficient cutting during expansion can be formed. Furthermore, the ratio of the height H1 to the width W1 of the protrusion 60 at the straight tube 23 is relatively large, meaning that the height H1 of the protrusion 60 is relatively small compared to its width W1 within the straight tube 23. This allows for a relatively small outer diameter of the balloon 2 during contraction, facilitating insertion of the balloon 2 into the body cavity. In addition, the reduced rigidity of balloon 2 makes it easier to contract, thus shortening the retraction time. This allows for shorter treatment times when multiple inflatations are required, as well as shorter times to remove the inflated balloon or deliver it to other lesions, enabling safer treatment with less burden on the patient.

[0069] The ratio W1 / H1 of the height H1 of the protrusion 60 at the straight tube 23 to the width W1 of the protrusion 60 is greater than the ratio W2 / H2 of the height H2 of the protrusion 60 at the proximal conical section 22. That is, the ratio W2 / H2 of the height H2 of the protrusion 60 in the proximal conical section 22 is relatively small, thus allowing the height H2 of the protrusion 60 in the proximal conical section 22 to be relatively large compared to its width W2. Consequently, the bending stiffness of the proximal conical section 22 in the long axis x direction is greater than that of the straight tube 23, thereby enabling it to become a balloon 2 with good pushability. In addition, the ratio of the height H2 to the width W2 of the protrusion 60 at the proximal lateral cone 22 is relatively small, that is, the width W2 of the protrusion 60 is relatively small compared with the height H2. This makes the area that becomes a three-dimensional obstacle when the balloon 2 is inserted into the body cavity narrower in the circumferential z direction, and makes it easier to insert the balloon 2 into the body cavity.

[0070] In this way, the balloon 2 can reduce the bending stiffness in the long axis x direction from the proximal side to the distal side of the balloon 2, thus enabling the balloon to have the best balance of bending stiffness as a whole, with good pushability, and good resistance to kinking and insertion.

[0071] Preferably, the width W1 of the protrusion 60 at the straight tube portion 23 is wider than the width W2 of the protrusion in the proximal conical portion 22. The relatively wider width W1 of the protrusion 60 at the straight tube portion 23 allows the area cut by the protrusion 60 of the straight tube portion 23 to be wider in the circumferential z direction, increasing the expansion force during cutting and making it easier to form a balloon 2 capable of efficient cutting. Furthermore, the relatively narrow width W2 of the protrusion 60 at the proximal conical portion 22 allows the area that becomes a three-dimensional obstacle when inserting the balloon 2 into the body cavity to be narrower in the circumferential z direction, making insertion of the balloon 2 into the body cavity easier.

[0072] Preferably, the W1 / H1 ratio at the straight pipe section 23 is 0.2 or higher and 5 or lower. The W1 / H1 ratio at the straight pipe section 23 can also be 0.4 or higher, 0.6 or higher, 0.8 or higher, 0.9 or higher, 1.0 or higher, 1.2 or higher, 1.25 or higher, 1.3 or higher, 1.5 or higher, or 2 or higher. Alternatively, the W1 / H1 ratio at the straight pipe section 23 can also be 4 or lower, 3.5 or lower, or 3 or lower.

[0073] Preferably, the W2 / H2 ratio at the proximal conical portion 22 is 0.2 or more and 5 or less. The W2 / H2 ratio at the proximal conical portion 22 may also be 0.3 or more, 0.4 or more, 0.5 or more, or 0.8 or more. Furthermore, the W2 / H2 ratio at the proximal conical portion 22 may also be 3 or less, 2 or less, 1.5 or less, 1.2 or less, or 1.1 or less, more preferably 1.0 or less, and even more preferably 0.9 or less.

[0074] Based on the requirement that the ratio W1 / H1 at the straight tube section 23 is greater than the ratio W2 / H2 at the proximal conical section 22, the ratio W1 / H1 at the straight tube section 23 and the ratio W2 / H2 at the proximal conical section 22 each have values ​​within the aforementioned range, thereby further improving the efficiency of cutting, the pushing ability, and the insertion permeability within the body cavity.

[0075] like Figure 10 As shown, preferably in a radial y-section, the protrusion 60 of the straight tube portion 23 has a front end portion 61, and the width W of the front end portion 61 of the protrusion 60 is... T The ratio W to the width W1 of the protrusion 60 T / W1 is less than 0.5. The width W of the front end 61 T Used in the radial y-section and the circumcircle C p Concentric circles with a common center O and a radius equal to the circumcircle C p radius r p 95% of the circle C T The length of the arc within the circumference of the protrusion 60 is defined by the length of the arc. The width W of the front end 61 is... T The ratio W to the width W1 of the protrusion 60 T / W1 is more preferably 0.4 or less, further preferably 0.3 or less, particularly preferably 0.25 or less, and may also be 0.2 or less, or may also be 0.1 or less. The width W of the front end portion 61 T The ratio W to the width W1 of the protrusion 60 T The lower limit of / W1 is not particularly limited, but it can be, for example, 0.01. The width W of the front end portion 61 of the protrusion 60... T With values ​​within the aforementioned range, when the balloon 2 is dilated at the lesion site, causing the straight tube 23 to come into contact with the stenosis, the area of ​​the anterior end 61 of the protrusion 60 that comes into contact with the stenosis becomes smaller, allowing a larger force to be applied to a smaller area, thereby increasing the stress on the stenosis and making it easier to cut the stenosis.

[0076] Preferably, the height H1 of the protrusion 60 of the straight tube 23 is at least 0.1 mm, provided that the ratio W1 / H1 in the straight tube 23 is greater than the ratio W2 / H2 in the proximal lateral cone 22. More preferably, the height H1 of the protrusion 60 of the straight tube 23 is 0.2 mm or more, further preferably 0.3 mm or more, and particularly preferably 0.4 mm or more. If the height H1 of the protrusion 60 of the straight tube 23 is the above-mentioned value, when the balloon 2 is dilated at the lesion site, causing the straight tube 23 to abut against the stenosis, the stress on the stenosis caused by the anterior end 61 of the protrusion 60 can be increased, making it easier to cut the stenosis. Furthermore, the height H1 of the protrusion 60 of the straight tube 23 is preferably 1 mm or less, more preferably 0.8 mm or less, further preferably 0.7 mm or less, and particularly preferably 0.6 mm or less. If the height H1 of the protrusion 60 of the straight tube 23 is a value below the above, good insertion permeability within the body cavity can be achieved when the balloon 2 is delivered to the lesion.

[0077] The stress on the stenotic portion caused by the height H1 of the protrusion 60 of the straight tube 23 is saturated in the region exceeding the aforementioned upper limit value, therefore it is not necessary for the height H1 of the protrusion 60 of the straight tube 23 to be large enough to exceed the aforementioned upper limit value. For the balloon 2 of the present invention, compared with the effect caused by the height H1 of the protrusion 60 of the straight tube 23, by satisfying the requirement that the ratio W1 / H1 in the straight tube 23 is greater than the ratio W2 / H2 in the proximal lateral cone 22, it is possible to ensure the stress imparted to the stenotic portion by the protrusion 60 of the straight tube 23 over a wider range in the circumferential z direction. Therefore, a balloon 2 can be formed that allows for efficient cutting while maintaining good insertionability without making the height H1 of the protrusion 60 of the straight tube 23 too large.

[0078] Preferably, the height T2 of the protrusion 60 at the proximal conical portion 22 is higher than the height T1 of the protrusion 60 at the straight tube portion 23. This results in higher bending rigidity along the long axis (x) at the proximal conical portion 22, leading to better delivery; conversely, the rigidity at the straight tube portion 23 is reduced, making balloon 2 easier to contract and easier to insert into the body cavity. However, regarding the aforementioned relationship between the height T2 of the protrusion at the proximal conical portion 22 and the height T1 of the protrusion 60 at the straight tube portion 23, it is important that the ratio W1 / H1 at the straight tube portion 23 is greater than the ratio W2 / H2 at the proximal conical portion 22. By satisfying this requirement, a balloon 2 can be formed that has good delivery, is easy to insert into the body cavity, and can efficiently perform stenosis incision.

[0079] like Figure 10 As shown, preferably in a radial y-section, the protrusion 60 of the straight tube portion 23 has a front end portion 61, and the front end portion 61 has an angle θ of 135° or less. The angle θ is more preferably 120° or less, even more preferably 100° or less, and may also be 90° or less, 80° or less, 60° or less, or 30° or less. Furthermore, the angle θ is preferably 5° or more, more preferably 10° or more, and even more preferably 20° or more. If the angle θ is within the above range, efficient cutting can be achieved.

[0080] like Figure 11 As shown, the protrusion 60 of the preferred straight tube 23 and the protrusion 60 of the proximal side cone 22 extend continuously in the long axis direction x. By having the protrusion 60 extend continuously from the proximal side cone 22 to the straight tube 23 in the long axis direction x, the rigidity of the balloon 2 can be improved, the over-expansion of the balloon 2 during pressurization can be suppressed, and the pushability can be further improved.

[0081] like Figure 12As shown, the distal conical portion 24 may also have a protrusion 60, and the height H3 of the protrusion 60 of the distal conical portion 24 is lower than the height H1 of the protrusion 60 of the straight tube portion 23. The distal conical portion 24 is the part that forms the anterior side when the balloon 2 is inserted into the body cavity. Therefore, by suppressing the height H3 of the protrusion of the distal conical portion 24 to a lower value, the outer diameter of the distal conical portion 24 is reduced, thereby making it easier to insert the balloon 2 into the body cavity. In the distal conical portion 24, the protrusion 60 may be disposed in the long axis direction x, between the proximal end and the distal end of the distal conical portion 24, or it may be disposed as a whole. From the viewpoint of making it easier to insert the balloon 2 into the body cavity, it is preferable that the protrusion 60 is disposed in a part of the distal conical portion 24 in the long axis direction x, and in this case, it is preferable that the protrusion 60 is disposed on the proximal end side of the distal conical portion 24, and that the protrusion 60 is not disposed on the distal end side of the distal conical portion 24. This allows for a reduction in the outer diameter of the distal end of the distal cone 24, thus enabling the formation of a structure that makes it easier to insert the balloon 2 into the body cavity.

[0082] The distal conical portion 24 may also have one or more protrusions 60, similar to the proximal conical portion 22 and the straight tube portion 23. Preferably, the protrusions 60 of the straight tube portion 23 and the protrusions of the distal conical portion 24 extend continuously in the long axis direction x. By having the protrusions 60 extend continuously from the straight tube portion 23 to the distal conical portion 24 in the long axis direction x, the rigidity of the balloon 2 can be improved, over-expansion of the balloon 2 during pressurization can be suppressed, and the delivery capability can be further improved.

[0083] like Figure 13 As shown, the distal cone 24 preferably has an inner protrusion 70, which protrudes radially inward from the inner surface of the balloon body 20 and extends in the long axis direction x. With this structure, even if the height H3 of the protrusion 60 at the distal cone 24 is relatively low, the rigidity of the distal cone 24 can be improved by reinforcing the balloon body 20 from the inside by the inner protrusion 70, thus suppressing excessive balloon expansion during inflation and further improving delivery. Furthermore, Figure 13 The diagram shows a configuration with a protrusion 60 in addition to the medial protrusion 70. However, if the distal cone 24 has the medial protrusion 70, the distal cone 24 may not have the protrusion 60. Even without the protrusion 60, the presence of the medial protrusion 70 can improve the rigidity of the distal cone 24 and suppress excessive expansion of the balloon 2 during pressurization.

[0084] like Figure 13As shown, the distal cone 24 preferably has a protrusion 60 and a medial protrusion 70, which are positioned at the same location in the circumferential z direction. The protrusion 60, which can reinforce the balloon body 20 from the outside, and the medial protrusion 70, which can reinforce the balloon body 20 from the inside, reinforce the balloon body 20 at the same location in the circumferential z direction of the distal cone 24, thus further suppressing excessive inflation of the balloon 2 during inflation.

[0085] Materials constituting the balloon body 20 include, for example, polyolefin resins such as polyethylene, polypropylene, and ethylene-propylene copolymer; 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 elastomers; fluorinated resins; silicone resins; and natural rubber such as latex rubber. Only one type of these can be used, or two or more types can be used in combination. Among these, polyamide resins, polyester resins, and polyurethane resins are suitable. In particular, considering the thin-film properties and flexibility of the balloon body 20, elastomer resins are preferred. 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 considering its ease of formation during blow molding. Furthermore, considering the thin-film properties and flexibility of the balloon body 20, polyamide elastomers such as polyether ester amide elastomers and polyamide ether elastomers are preferred. Among these considerations, considering the high yield strength and good dimensional stability of the balloon body 20, polyether ester amide elastomer is preferred.

[0086] Preferably, the protrusion 60 is made of the same material as the balloon body 20. If the protrusion 60 is made of the same material as the balloon body 20, the flexibility of the balloon 2 can be maintained, and the protrusion 60 is less likely to damage the outer surface of the balloon body 20. Preferably, the balloon body 20 and the protrusion 60 are integrally formed. This prevents the protrusion 60 from detaching from the balloon body 20.

[0087] In the configuration where the distal conical portion 24 has an inner protrusion 70, the inner protrusion 70 is preferably made of the same material as the balloon body 20 for the same reasons as described above.

[0088] balloon 2, for example, by... Figure 14A preform 200, as shown, having at least a portion of a thick-walled portion 220 made of resin in the circumferential z direction and extending in the long axis x direction, is disposed in a mold with an inner cavity and subjected to biaxial stretch blow molding. The protrusion 60 can be formed, for example, by inserting the preform 200 into the inner cavity of the mold, causing the thick-walled portion 220 of the preform 200 to enter the groove of the mold, and introducing fluid into the inner cavity 210 of the preform 200 to cause the preform 200 to expand. The width and height of the protrusion 60 can be adjusted by the thickness of the thick-walled portion 220 of the preform 200, the depth of the groove in the mold, and the shape. Furthermore, to form a distal side cone 24 having an inner protrusion 70, for example, it can be formed by pressing a portion of the thick-walled portion 220 of the preform 200 corresponding to the distal side cone 24 against a shallow or non-grooved portion of the mold groove, and introducing fluid into the inner cavity 210 of the preform 200 to cause the preform 200 to expand. When using a mold with a shallow groove in this part, it is possible to form a structure in which the protrusion 60 and the inner protrusion 70 are positioned at the same location in the circumferential direction z. When using a mold in which the groove in this part does not exist, it is possible to form a structure in which the protrusion 60 is not formed but the inner protrusion 70 is formed. As the material constituting the preform 200, it is possible to refer to the material constituting the above-described balloon body 20.

[0089] Examples of materials constituting the shaft 3 include polyamide resins, polyester resins, polyurethane resins, polyolefin resins, fluorinated resins, vinyl chloride resins, silicone resins, and natural rubber. Only one type may be used, or two or more may be used in combination. Preferably, the material constituting the shaft 3 is at least one of polyamide resins, polyolefin resins, and fluorinated resins. This improves the slipperiness of the shaft 3 surface, thereby enhancing the insertion portability of the balloon catheter 1 within the body cavity.

[0090] For the joining of balloon 2 and shaft 3, methods such as joining with adhesive, fusion bonding, and riveting by installing a ring-shaped component at the overlapping part of the end of balloon 2 and shaft 3 can be used. Among these, joining balloon 2 and shaft 3 by fusion bonding is preferred. When balloon 2 and shaft 3 are fused, the joining of balloon 2 and shaft 3 is not easily dislodged even if balloon 2 is repeatedly expanded and contracted, which can easily improve the joining strength of balloon 2 and shaft 3.

[0091] like Figure 1As shown, in the balloon catheter 1, a hub 4 may be provided proximal to the shaft 3, and a fluid injection section 7 communicating with the flow path of fluid supplied to the interior of the balloon 2 may be provided in the hub 4. Furthermore, it is preferable that the hub 4 has a guidewire insertion section 5 communicating with the guidewire insertion path. By having a hub 4 with a fluid injection section 7 and a guidewire insertion section 5 in the balloon catheter 1, it is possible to easily perform the operation of supplying fluid to the interior of the balloon 2 to inflate the balloon 2, and the operation of delivering the balloon 2 to the treatment site along the guidewire. The balloon 2 according to the embodiments of the present invention can be applied not only to… Figure 1 The so-called OTW (Over-The-Wire) balloon catheter, which inserts a guidewire from the distal side to the proximal side of axis 3 as shown, can also be used as the so-called RX (Rapid Exchange) balloon catheter, which inserts a guidewire from the distal side of axis to the proximal side.

[0092] For the joining of shaft 3 and pivot 4, examples include bonding with adhesives and fusion bonding. Among these, it is preferable that shaft 3 and pivot 4 are joined by adhesive bonding. By bonding shaft 3 and pivot 4, for example, when the materials constituting shaft 3 and pivot 4 are different, such as when shaft 3 is made of a highly flexible material and pivot 4 is made of a highly rigid material, the joining strength between shaft 3 and pivot 4 can be improved, thereby improving the durability of balloon catheter 1.

[0093] This application claims a priority interest based on Japanese Patent Application No. 2021-41378, filed on March 15, 2021. The entire contents of the description of Japanese Patent Application No. 2021-41378, filed on March 15, 2021, are incorporated herein by reference.

[0094] Explanation of reference numerals in the attached figures

[0095] 1...Balloon catheter; 2...Balloon; 3...Axis; 4...Pivot; 5...Guidewire insertion section; 7...Fluid injection section; 20...Balloon body; 21...Proximal sleeve section; 22...Proximal cone section; 23...Straight tube section; 24...Distal cone section; 25...Distal sleeve section; 31...Outer tube; 32...Inner tube; 60...Protrusion; 61...Anterior end portion; 70...Inner protrusion; 200...Preform; 210...Inner cavity of the preform; 220...Thick-walled portion of the preform; C b ...the circumcircle of the balloon body; r b...radius of the circumcircle of the balloon body; H1...height of the protrusion at the straight tube; H2...height of the protrusion at the proximal conical section; H3...height of the protrusion at the distal conical section; W1...width of the protrusion at the straight tube; W2...width of the protrusion at the proximal conical section; W... T ...width of the front end of the protrusion at the straight section; x...major axis direction; y...radial direction; z...circumferential direction.

Claims

1. A balloon for a balloon catheter, characterized in that, It has a balloon body with an outer surface and an inner surface. It has a major axis, a radial direction, and a circumferential direction. The radial direction is the direction connecting the centroid of a shape that outlines the shape of the balloon body in its expanded state to a point on the outer surface in a cross-section perpendicular to the major axis. The circumferential direction is the direction along the outer periphery of the balloon body in its expanded state in the radial cross-section. The balloon body has: a straight tube portion; a proximal conical portion located closer to the straight tube portion; and a distal conical portion located more distal to the straight tube portion. The balloon body has protrusions in the straight section and the proximal lateral cone section, the protrusions projecting radially outward from the outer surface of the balloon body and extending along the long axis. The ratio of the height H1 to the width W1 of the protrusion at the straight tube section, W1 / H1, is greater than the ratio of the height H2 to the width W2 of the protrusion at the proximal lateral cone section, W2 / H2. The distal conical portion has the protrusion, and the height H3 of the protrusion of the distal conical portion is lower than the height H1 of the protrusion of the straight tube portion. Here, the height and width of the protrusion are defined as follows: In the radial section, the circumcircle C of the balloon body b The radius and the circumcircle C b The circumcircle C of the protrusion with the common center p The difference in radii is taken as the height of the protrusion. In the radial section, and the circumcircle C b The width of the protrusion is defined as the maximum length of the arc within the outline of the protrusion in the circumference of the concentric circles that share a common center.

2. The balloon for balloon catheters according to claim 1, characterized in that, The width W1 of the protrusion at the straight tube portion is wider than the width W2 of the protrusion at the proximal side cone portion.

3. The balloon for balloon catheters according to claim 1 or 2, characterized in that, The ratio W1 / H1 at the straight pipe section is 0.2 or higher and 5 or lower.

4. The balloon for balloon catheters according to claim 1 or 2, characterized in that, The ratio W2 / H2 at the proximal lateral cone is 0.2 or higher and 5 or lower.

5. The balloon for balloon catheters according to claim 1 or 2, characterized in that, In the radial cross-section, the protrusion of the straight tube section has a front end portion, and the width W of the front end portion of the protrusion is... T The ratio W to the width W1 of the protrusion T / W1 is below 0.5 Here, the width of the front end of the protrusion is defined as follows: In the radial section, and the circumcircle C p Concentric circles with a common center and a radius equal to the circumcircle C p The length of the arc inside the outline of the protrusion within the circumference of a circle that is 95% of the radius is taken as the width of the front end.

6. The balloon for balloon catheters according to claim 1 or 2, characterized in that, The height H1 of the protrusion of the straight pipe section is at least 0.1 mm.

7. The balloon for balloon catheters according to claim 1 or 2, characterized in that, In the radial cross-section, the protrusion of the straight tube has a front end portion with an angle of less than 135°.

8. The balloon for balloon catheters according to claim 1 or 2, characterized in that, The protrusion of the straight tube and the protrusion of the proximal side cone extend continuously along the long axis.

9. The balloon for balloon catheters according to claim 1 or 2, characterized in that, The protrusion of the straight tube portion and the protrusion of the distal side cone portion extend continuously along the long axis.

10. The balloon for balloon catheters according to claim 1 or 2, characterized in that, The distal conical portion has an inner protrusion that protrudes radially inward from the inner surface of the balloon body and extends along the long axis.

11. The balloon for balloon catheters according to claim 10, characterized in that, The protrusions of the distal lateral cone and the medial protrusion are positioned at the same location in the circumferential direction.

12. The balloon for balloon catheters according to claim 1 or 2, characterized in that, The protrusion is made of the same material as the balloon body.

Images