Catheter balloon with segments of varying compliance - Patents.com

Abstract

An inflatable balloon for a balloon catheter is disclosed, the inflatable balloon including segments of varying compliance. In one example, an inflatable balloon for a medical catheter includes a first segment having a first compliance and a second segment having a second compliance, the first compliance being higher than the second compliance. The first and second segments extend axially along a length of the balloon, and the first segment is configured to axially rupture prior to the second segment under pressure from an inflation fluid introduced into the balloon.

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of U.S. Provisional Patent Application No. 63 / 264,702, filed November 30, 2021, which is incorporated by reference in its entirety herein.

[0002] The present disclosure relates to inflatable balloons for balloon catheters, such as delivery devices for radially expandable medical devices. [Background technology]

[0003] The human heart can suffer from a variety of valvular diseases that can cause serious cardiac dysfunction, ultimately requiring repair of the native valve or replacement of the native valve with a prosthetic valve. Numerous repair devices (e.g., stents) and prosthetic valves are known, as are numerous methods for implanting them in humans. Percutaneous and minimally invasive surgical approaches can be used in a variety of procedures to deliver prosthetic medical devices to locations within a patient's body that are not easily accessible by surgery and where access without surgery is desirable. In one specific example, a prosthetic heart valve can be crimped onto the distal end of a delivery device and advanced through the patient's vascular system (e.g., through the femoral artery and aorta) until the prosthetic valve reaches the implantation site in the heart. The prosthetic valve is then expanded to its functional size, for example, by inflating a balloon on which the prosthetic valve is mounted. Summary of the Invention

[0004] Described herein are inflatable balloons for medical (balloon) catheters. In some embodiments, the inflatable balloons described herein can be used in a delivery device for a prosthetic heart valve. Described herein are examples of delivery devices, prosthetic heart valves, and methods for implanting the delivery devices and prosthetic heart valves. The disclosed balloons and methods for manufacturing the balloons can provide balloons with segments of varying compliance configured, for example, to axially burst the balloon under pressure from an inflation pressure received by the balloon. Thus, the devices and methods disclosed herein can overcome, among other things, one or more deficiencies associated with typical delivery devices.

[0005] A balloon catheter can include a handle, one or more shafts coupled to the handle, and an inflatable balloon attached to the shaft.

[0006] In some embodiments, the balloon of the balloon catheter can include two or more segments of varying compliance configured to axially rupture the balloon under pressure from the inflation pressure received by the balloon.

[0007] In some embodiments, the balloon of the balloon catheter can include two or more sections having different durometers, one of the sections including a discontinuity extending axially along the balloon.

[0008] In some embodiments, an inflatable balloon for a medical catheter includes a first segment having a first compliance and a second segment having a second compliance, the first compliance being greater than the second compliance, the first segment and the second segment extending axially along a length of the balloon, and the first segment configured to rupture axially prior to the second segment under pressure from an inflation fluid introduced into the balloon.

[0009] In some embodiments, an inflatable balloon for a medical catheter includes a first circumferential segment including one or more layers of a first material having a first durometer, the one or more layers extending across a thickness of the balloon. The balloon further includes a second circumferential segment including one or more layers of the first material and one or more layers of a second material having a second durometer, the second durometer being greater than the first durometer. The first circumferential segment is configured to axially form a rupture prior to the second circumferential segment under pressure from an inflation fluid introduced into the balloon.

[0010] In some embodiments, an inflatable balloon for a medical catheter includes a first portion having a first durometer, a second portion having a second durometer greater than the first durometer, and a discontinuity in the second portion, the discontinuity extending axially along the length of the balloon.

[0011] In some embodiments, a balloon catheter includes a shaft extending from a handle of the balloon catheter and an inflatable balloon attached to the shaft, the balloon including a plurality of axially extending circumferential segments having different compliances, the plurality of segments configured such that when the balloon is inflated with an inflation fluid, a first segment having a higher compliance than a second segment is configured to rupture axially along the balloon before the second segment.

[0012] In some embodiments, an inflatable balloon for a medical catheter includes an inner surface configured to contact a fluid used to inflate the balloon and one or more reinforcing elements disposed on the inner surface, each reinforcing element extending axially along the balloon.

[0013] In some embodiments, a balloon catheter includes a shaft extending from a handle of the balloon catheter and an inflatable balloon attached to the shaft, the balloon including one or more reinforcing elements disposed on an inner surface of the balloon, each reinforcing element extending axially along the balloon and providing a radially increased thickness to the balloon at selected circumferential locations along the axial length of the balloon.

[0014] In some embodiments, the balloon and / or balloon catheter comprises one or more of the components listed in Examples 1-67 below.

[0015] The various innovations of the present disclosure can be used in combination or separately. This Summary is provided to introduce in a simplified form a selection of various concepts that are further described in the Detailed Description below. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. These and other objects, features, and advantages of the present disclosure will become more apparent from the following Detailed Description, from the claims, and from the accompanying drawings. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a perspective view of a prosthetic heart valve, according to one embodiment. [Diagram 2] FIG. 2 is a perspective view of a delivery device for a prosthetic heart valve, according to one embodiment. [Diagram 3] FIG. 3 is a perspective view of an exemplary transversely lacerated balloon. [Figure 4] FIG. 4 is an exemplary graph showing the outer diameter of a balloon as the inflation pressure of an inflation fluid contained within the balloon increases, the graph showing the threshold pressure for bursting for two materials of various durometers within the balloon. [Diagram 5]FIG. 5 is a cross-sectional view of an exemplary balloon comprising axially extending circumferential segments configured to rupture axially before the remainder of the balloon under pressure from an inflation fluid introduced into the balloon. [Figure 6] FIG. 6 is a perspective view of the balloon of FIG. [Figure 7] FIG. 7 is a cross-sectional view of an exemplary balloon comprising multiple axially extending circumferential segments configured to rupture axially prior to the remainder of the balloon. [Figure 8] FIG. 8 is a cross-sectional view of an exemplary balloon comprising multiple axially extending circumferential segments configured to rupture axially prior to the remainder of the balloon. [Figure 9] 9A-9C are cross-sectional views of an exemplary balloon having an axially extending circumferential segment configured to axially rupture prior to the remainder of the balloon, illustrating the greater growth of the circumferential segment compared to the remainder of the balloon, which comprises a higher durometer material, at various stages of balloon expansion. [Figure 10] FIG. 10 is a cross-sectional view of an exemplary balloon comprising multiple axially extending circumferential segments formed by discontinuities in a higher durometer portion of the balloon that are configured to axially rupture prior to the remainder of the balloon. [Figure 11] FIG. 11 is a cross-sectional view of an exemplary balloon comprising multiple axially extending circumferential segments formed by discontinuities in a higher durometer portion of the balloon and configured to axially rupture prior to the remainder of the balloon. [Figure 12] FIG. 12 is a cross-sectional view of an exemplary balloon comprising multiple axially extending circumferential segments formed by discontinuities in a higher durometer portion of the balloon that are configured to axially rupture prior to the remainder of the balloon. [Figure 13]FIG. 13 is a cross-sectional view of an exemplary balloon with a discontinuity created by overlapping ends of a higher durometer portion of the balloon, the discontinuity forming an axially extending circumferential segment configured to rupture prior to the remainder of the balloon. [Figure 14] FIG. 14 is a cross-sectional view of an exemplary balloon with a discontinuity created by overlapping ends of a higher durometer portion of the balloon, the discontinuity forming an axially extending circumferential segment configured to rupture prior to the remainder of the balloon. [Figure 15] FIG. 15 is a cross-sectional view of an exemplary balloon with two portions having different durometers, where the change in compliance or durometer around the circumference of the balloon is created by varying the number of layers in the higher durometer portion of the balloon within the lower durometer portion of the balloon. [Figure 16] FIG. 16 is a cross-sectional view of an exemplary balloon including a circumferentially extending, higher durometer section that varies in thickness circumferentially and a circumferentially extending, lower durometer section that surrounds the higher durometer section such that an axially extending circumferential segment is formed in the area of ​​the thinner portion of the higher durometer section, configured to rupture prior to the remainder of the balloon. [Figure 17] FIG. 17 is a cross-sectional view of an exemplary balloon comprising multiple axially extending circumferential segments formed by discontinuities in a higher durometer portion of the balloon that are configured to axially rupture prior to the remainder of the balloon. [Figure 18] FIG. 18 is a cross-sectional view of an exemplary balloon comprising an axially extending circumferential segment formed by a discontinuity in a higher durometer portion of the balloon, which is configured to rupture axially prior to the remainder of the balloon. [Figure 19]FIG. 19 is a cross-sectional view of an exemplary balloon configured to axially rupture prior to the remainder of the balloon and including an axially extending circumferential segment formed by a discontinuity in one or more higher durometer portions of the balloon. [Figure 20] FIG. 20 is a cross-sectional view of an exemplary balloon filled with a lower durometer material and formed by a discontinuity in a higher durometer portion of the balloon, the circumferential segment extending in the axial direction, configured to rupture axially prior to the remainder of the balloon. [Figure 21] FIG. 21 is a cross-sectional view of an exemplary balloon filled with a lower durometer material and formed by a discontinuity in a higher durometer portion of the balloon, the circumferential segment extending in the axial direction, configured to rupture axially prior to the remainder of the balloon. [Figure 22] FIG. 22 is a cross-sectional view of an exemplary balloon comprising an axially extending circumferential segment formed by a discontinuity in a higher durometer portion of the balloon, configured to rupture axially prior to the remainder of the balloon. [Diagram 23] FIG. 23 is a cross-sectional view of an exemplary balloon with axially extending circumferential segments formed by discontinuities in one or more durometer transition layers of the balloon filled with a lower durometer material, the circumferential segments being configured to rupture axially before the remainder of the balloon. [Figure 24] FIG. 24 is a cross-sectional view of an exemplary balloon having multiple layers of varying durometer portions of the balloon and axially extending circumferential segments formed by discontinuities in the higher durometer portions, the circumferential segments configured to rupture axially prior to the remainder of the balloon. [Diagram 25]FIG. 25 is a flowchart of a method for forming a balloon having one or more circumferential segments that have a higher compliance (and lower durometer) than the remainder of the balloon, such that the one or more circumferential segments are configured to rupture axially before the remainder of the balloon under pressure from inflation fluid introduced into the balloon. [Figure 26] FIG. 26 is a cross-sectional view of an exemplary extruded balloon tube prior to being formed into a balloon, the balloon tube including one or more axially extending reinforcing elements disposed on an interior surface of the balloon tube, the one or more reinforcing elements being configured such that a balloon formed from the balloon tube will axially rupture under a threshold pressure from an inflation fluid introduced into the balloon. [Figure 27] 27 is a cross-sectional view of a portion of a balloon formed from the balloon tube of FIG. 26. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] General Considerations For purposes of this specification, certain aspects, advantages, and novel features of the disclosed embodiments are described herein. The disclosed methods, apparatus, and systems should not be construed as limiting in any way. Instead, the disclosure is directed to all novel and non-obvious features and aspects of the various disclosed embodiments, alone, in various combinations with each other, and in various subcombinations with each other. The methods, apparatus, and systems are not limited to any particular aspect or feature, or combination thereof, nor do the disclosed embodiments require that any one or more particular advantages exist or problems be solved.

[0018] Although some operations of the disclosed embodiments are described in a particular sequential order for convenience of presentation, it should be understood that this method of description encompasses reordering, unless a particular order is required by specific language described below. For example, operations described sequentially may be reordered or performed simultaneously in some cases. Moreover, for simplicity, the accompanying drawings may not show various ways in which the disclosed methods may be used in combination with other methods. Additionally, the description sometimes uses terms such as "provide" or "achieve" to describe the disclosed methods. These terms are high-level abstractions of the actual operations that are performed. The actual operations that correspond to these terms may vary depending on the specific implementation, as would be readily discernible by one of ordinary skill in the art.

[0019] As used in this application and the claims, the singular forms "a," "an," and "the" include the plural forms unless the context clearly dictates otherwise. Additionally, the term "includes" means "comprises." Furthermore, the term "coupled" generally means to physically, mechanically, chemically, magnetically, and / or electrically connect or join together, and does not exclude the presence of intermediate elements between connected or associated members, unless specifically stated to the contrary.

[0020] As used herein, the term "proximal" refers to a position, orientation, or portion of a device that is closer to the user and away from the implantation site. As used herein, the term "distal" refers to a position, orientation, or portion of a device that is farther away from the user and closer to the implantation site. Thus, for example, proximal movement of a device is movement of the device away from the implantation site toward the user (e.g., outside the patient's body), while distal movement of a device is movement of the device away from the user toward the implantation site (e.g., into the patient's body). The terms "longitudinal" and "axial" refer to axes extending in the proximal and distal directions, unless expressly defined otherwise.

[0021] Overview of the disclosed technology As introduced above, the prosthetic heart valve may be crimped onto the distal end of the delivery device and advanced through the patient's vascular system (e.g., through the femoral artery and aorta) until the prosthetic valve reaches the implantation site in the heart. The prosthetic valve is then expanded to its functional size, for example, by inflating a balloon on which the prosthetic valve is mounted. In some instances, the balloon of the delivery device may tear during the implantation procedure, such as by inadvertent overinflation. A transverse tear across the balloon may cause the balloon to get stuck (on the prosthetic heart valve or another type of expandable device implanted with the delivery device, or on the delivery device) when the delivery device is removed from the patient's body. This may increase the complexity and / or duration of the implantation procedure.

[0022] Thus, a need exists for improved balloons for delivery devices or balloon catheters, and methods of making balloons for delivery devices, that avoid balloon degradation or tears (e.g., side tears) that can cause the balloon to get stuck.

[0023] Described herein are examples of inflatable balloons for balloon catheters, where the balloon has two or more circumferential segments that vary in compliance. The difference in compliance between the two or more circumferential segments may be due to different durometer materials in the different circumferential segments. Each circumferential segment may extend axially along the balloon. A circumferential segment of the balloon that has a higher compliance (and lower durometer) than other circumferential segments of the balloon may be configured to rupture axially under pressure from an inflation fluid introduced into the balloon prior to the remainder of the balloon. In this manner, the balloon may be configured to rupture axially, rather than laterally, when a threshold inflation pressure is reached.

[0024] In some embodiments, as described above, circumferential segments of varying compliance can be created by utilizing materials of different durometers to form the different circumferential segments.

[0025] In some embodiments, circumferential segments of varying compliance can be created with axially extending reinforcing elements disposed on the inner circumferential surface of the balloon, and on the outer circumferential surface of the balloon, or on both the inner and outer circumferential surfaces of the balloon.

[0026] Also described herein are methods for forming an inflatable balloon having two or more segments of varying compliance and / or durometer.

[0027] The prosthetic valves disclosed herein may be radially compressible and radially expandable between a radially compressed state and a radially expanded state. Thus, the prosthetic valve may be crimped or held by an implant delivery device in a radially compressed state during delivery, and then expanded to a radially expanded state after the prosthetic valve reaches the implantation site. It is understood that the prosthetic valves disclosed herein may be used with a variety of implant delivery devices and may be implanted via a variety of delivery procedures, examples of which will be described in more detail below.

[0028] Examples of the disclosed technology FIG. 1 illustrates an exemplary prosthetic valve 10, according to one embodiment. Any prosthetic valve disclosed herein is adapted to be implanted in the native aortic annulus, but in some embodiments may be adapted to be implanted in other native annuluses of the heart (pulmonary, mitral, and tricuspid valves). The disclosed prosthetic valves may also be implanted within blood vessels communicating with the heart, including the pulmonary artery (to replace the function of a diseased pulmonary valve), the superior vena cava or the inferior vena cava (to replace the function of a diseased tricuspid valve), or various other veins, arteries, and blood vessels of the patient. The disclosed prosthetic valves may also be implanted within a prosthetic valve previously implanted in a valve-in-valve procedure, which may be a prosthetic surgical valve or a prosthetic transcatheter heart valve.

[0029] In some examples, the disclosed prosthetic valves can be implanted within a docking device or anchoring device that is implanted within a native heart valve or blood vessel. For example, in one example, the disclosed prosthetic valves can be implanted within a docking device implanted within the pulmonary artery to replace the function of a diseased pulmonary valve, as disclosed in U.S. Patent Application Publication No. 2017 / 0231756, which is incorporated herein by reference. In some examples, the disclosed prosthetic valves can be implanted within a docking device implanted within a native mitral valve or at the mitral valve, as disclosed in International Publication No. WO2020 / 247907, which is incorporated herein by reference. In some examples, the disclosed prosthetic valves can be implanted within a docking device implanted within the superior or inferior vena cava to replace the function of a diseased tricuspid valve, as disclosed, for example, in U.S. Patent Application Publication No. 2019 / 0000615, which is incorporated herein by reference.

[0030] The prosthetic valve 10 may include four main components: a stent or frame 12, a valvular structure 14, an inner skirt 16, and a perivalvular outer seal member or outer skirt 18. The prosthetic valve 10 may have an inflow end portion 15, a middle portion 17, and an outflow end portion 19.

[0031] The valvular structure 14 may include three leaflets 40 that collectively form a leaflet structure, and these three leaflets may be configured to collapse in a tricuspid arrangement, although in other examples, a greater or lesser number of leaflets may be present (e.g., one or more leaflets 40). The leaflets 40 may be secured to one another at their adjacent sides to form the commissures 22 of the valve (e.g., leaflet) structure 14. The lower edge of the valvular structure 14 may have an undulating, curved, scalloped shape and may be secured to the inner skirt 16 by sutures (not shown). In some examples, the leaflets 40 may be formed from pericardial tissue (e.g., bovine pericardial tissue), a biocompatible synthetic material, or a variety of other suitable natural or synthetic materials known in the art, such as those described in U.S. Pat. No. 6,730,118, which is incorporated herein by reference.

[0032] The frame 12 can be formed with a plurality of circumferentially spaced slots or commissure windows 20 adapted to attach the commissures 22 of the valvular structure 14 to the frame. The frame 12 can be made from any of a variety of suitable plastically expandable materials (e.g., stainless steel, etc.) or self-expanding materials (e.g., nickel titanium alloys (NiTi), such as Nitinol) known in the art. When constructed from a plastically expandable material, the frame 12 (and thus the prosthetic valve 10) can be crimped into a radially collapsed configuration on a delivery catheter and then expanded inside the patient by an inflatable balloon or equivalent expansion mechanism. When constructed from a self-expandable material, the frame 12 (and thus the prosthetic valve 10) can be crimped into a radially collapsed configuration and restrained in the collapsed configuration by insertion within a sheath or equivalent mechanism of the delivery catheter. Once inside the body, the prosthetic valve can be advanced from a delivery sheath, which allows the prosthetic valve to expand to its functional size.

[0033] Suitable plastically expandable materials that may be used to form the frame 12 include, but are not limited to, stainless steel, a biocompatible high-strength alloy (e.g., cobalt-chromium alloy or nickel-cobalt-chromium alloy), a polymer, or a combination thereof. In a particular example, the frame 12 is made of a nickel-cobalt-chromium-molybdenum alloy, such as MP35N® alloy (SPS Technologies, Jenkintown, PA), which is equivalent to UNS R30035 alloy (covered by ASTM F562-02). MP35N® alloy / UNS R30035 alloy includes 35% nickel, 35% cobalt, 20% chromium, and 10% molybdenum by weight. Additional details regarding the prosthetic valve 10 and its various components are described in International Patent Application Publication No. WO2018 / 222799, which is incorporated herein by reference.

[0034] 2 illustrates an example delivery device 100 that may be used to implant an expandable prosthetic heart valve (e.g., prosthetic valve 10 or 50) or another type of expandable prosthetic medical device (such as a stent). In some embodiments, the delivery device 100 is specifically adapted for use in introducing a prosthetic valve into the heart.

[0035] 2 is a balloon catheter including a handle 102, a steerable outer shaft 104 extending from the handle 102, a middle shaft extending coaxially from the handle 102 through the steerable outer shaft 104, an inner shaft 106 extending coaxially from the handle 102 through the middle shaft and the steerable outer shaft 104, an inflatable balloon (e.g., balloon) 108 extending from a distal end of the middle shaft, and a nose cone 110 disposed at the distal end of the delivery device 100. The distal end portion 112 of the delivery device 100 includes the balloon 108, the nose cone 110, and a balloon shoulder assembly. A prosthetic medical device, such as a prosthetic heart valve, may be mounted on the valve retaining portion of the balloon 108. The balloon shoulder assembly is configured to maintain the prosthetic heart valve or other medical device in a fixed position on the balloon 108 during delivery through the patient's vasculature. In some embodiments, the balloon shoulder assembly can include a proximal shoulder 120 and / or a distal shoulder 122 .

[0036] The balloon 108 may include a central portion (which may be generally cylindrical when inflated, as shown in FIG. 2) and two tapered ends that connect to the delivery device 100 (e.g., one or more shafts and / or nosecones of the delivery device). The length of the balloon 108 may be defined in an axial direction 124 (which may be parallel to a central longitudinal axis of the delivery device 100 and the balloon 108). Additionally, a transverse (or radial) direction 126 may be defined perpendicular to the axial direction 124.

[0037] The handle 102 can include a steering mechanism configured to adjust the curvature of the distal end portion of the delivery device. In the illustrated embodiment, for example, the handle 102 includes an adjustment member, such as the illustrated rotatable knob 134, which in turn is operably coupled to a proximal end portion of a pull wire (not shown). The pull wire extends distally from the handle 102 through the outer shaft 104 and has a distal end portion affixed to the outer shaft at or near the distal end of the outer shaft 104. Rotating the knob 134 is effective to increase or decrease tension in the pull wire, thereby adjusting the curvature of the distal end portion of the delivery device.

[0038] The delivery device 100 can be configured to be advanced over a guidewire, which can be received within a guidewire lumen defined by the innermost shaft of the delivery device 100.

[0039] In some examples, the delivery device (or a similar delivery device) can be configured to deploy and implant a prosthetic heart valve (e.g., prosthetic valve 10 of FIG. 1) within the native annulus of a native aortic valve. Further details regarding such delivery devices can be found in International Patent Application No. PCT / US2021 / 047056, which is incorporated herein by reference.

[0040] As an example, during an implantation procedure for implanting an expandable prosthetic heart valve (e.g., prosthetic valve 10 of FIG. 1), a distal end portion of delivery device 100 (or a similar delivery device or balloon catheter) can be advanced (over a guidewire) to a target implantation site. Balloon 108 can then be inflated to radially expand and implant the prosthetic heart valve at the implantation site.

[0041] In some embodiments, the balloon may rupture (e.g., tear) during the implantation procedure. As shown in the embodiment of FIG. 3, the balloon 200 may experience a lateral tear 202. As used herein, a lateral tear may refer to a tear that occurs across the balloon 200 in a plane that is substantially perpendicular to the central longitudinal axis of the balloon 200 and defined by the radial and circumferential directions (e.g., the lateral tear 126 shown in FIG. 2, or a substantially lateral tear, such as across the entire or a portion of the balloon). A lateral tear, such as the lateral tear 202 shown in FIG. 3, may form a circumferentially extending tear edge on the balloon. Thus, a lateral tear, such as the exemplary lateral tear 202, may cause a portion of the ruptured balloon to get caught when the delivery device 100 is removed from the patient's vasculature. For example, a portion of the ruptured balloon may get caught on a prosthetic medical device (e.g., a valve) or on the delivery device. Efforts to remove the trapped balloon can increase procedure time and cost.

[0042] In some embodiments, it may be advantageous for the balloon to tear axially 124 (FIG. 2), or longitudinally, along the balloon in a direction parallel to the central longitudinal axis of the balloon. Axial tears can form tear edges that extend axially along at least a portion of the balloon. Longitudinal or axial tears can facilitate removal of the ruptured balloon, as all portions of the ruptured balloon may remain connected to the balloon catheter (e.g., delivery device 100 of FIG. 2).

[0043] By designing the balloon to have a radial strength distribution or radial balloon strain distribution, the balloon can be designed to rupture axially after a threshold (such as a predetermined lower threshold pressure or inflation pressure) is reached. In this manner, the balloon can be designed to rupture axially prior to rupturing laterally. As a result, a ruptured balloon can be more easily retrieved and removed from the patient.

[0044] As used herein, an axial direction may refer to a direction parallel to the central longitudinal axis of the balloon (e.g., axial direction 124 shown in FIG. 2), and a radial direction may refer to a direction extending radially outward from the central longitudinal axis of the balloon and perpendicular to the axial direction. A lateral direction (e.g., lateral direction 126 shown in FIG. 2) may also extend perpendicular to the central longitudinal axis of the balloon (e.g., across the balloon). A circumferential direction may refer to a direction around an object (e.g., a balloon). Additionally, the thickness of a balloon may be defined radially between the inner and outer circumferential surfaces of the balloon. When inflated, the inner circumferential surface of the balloon may face and contact the inflation fluid within the balloon.

[0045] Designing a balloon to rupture axially can be accomplished by varying the durometer of the material used to form the balloon. For example, a balloon can be extruded with one or more layers having materials of varying durometers. The balloon can then be constructed of multiple circumferential segments or portions (referred to herein as circumferential segments) formed by different layers of materials of different durometers and having different compliances (or durometers). The circumferential segments having higher compliance and / or lower durometers can be configured to rupture (or rupture) before the segments of the balloon having lower compliance and / or higher durometers.

[0046] Durometer, as used herein, may refer to the hardness of a material. A higher durometer material may be harder and less compliant than a lower durometer material. Thus, as used herein, a lower durometer material may have a higher (more compliant) compliance than a higher durometer material. As an example, a material with higher compliance can stretch more than a material with lower compliance, so that as the balloon stretches, the material with higher compliance becomes thinner, thereby causing the material with lower durometer and higher compliance to rupture before the material with higher durometer and lower compliance.

[0047] Figure 4 is a graph 300 illustrating the behavior of different durometer materials within the same balloon, or different segments of a balloon including different durometer materials, as the balloon is inflated with an inflation fluid. Specifically, graph 300 in Figure 4 illustrates the outer diameter of an inflated balloon (such as the balloon shown in Figures 5 and 6, or Figure 8, described below) on the y-axis and the inflation pressure on the x-axis. As the inflation pressure from the inflation fluid within the balloon increases, the outer diameter of the inflated balloon increases. Graph 300 illustrates three lines or curves that represent the behavior of three different circumferential balloon segments extending axially of an exemplary balloon. The three lines or curves of the graph 300 include a first line 302 illustrating the outer diameter of a first balloon segment including a first material having a first durometer (lower durometer), a second line 304 illustrating the outer diameter of a second balloon segment including a second material having a second durometer (higher durometer) greater than the first durometer, and a third line 305 illustrating the outer diameter of a third balloon segment made of a combination of both the first and second materials (e.g., different layers of each). As illustrated by the first line 302, the first balloon segment including the first material is configured to rupture at a first pressure P1 that is lower than a second pressure P2 at which the second balloon segment including the second material is configured to rupture, and a third pressure P3 at which the third balloon segment including a combination of the first and second materials is configured to rupture. For example, the first material may have a higher compliance (due to a lower durometer) so that as the inflation pressure increases (and the balloon outer diameter increases), the first material may stretch more, thereby thinning and bursting before the second material (because the second material has a lower compliance, stretches less, and therefore does not thin as quickly as the first material). Because the third balloon segment includes a combination of the first and second materials, the third pressure P3 is between the first pressure P1 and the second pressure P2. Whether the third pressure P3 is closer to the first pressure P1 or the second pressure P2 depends on whether the proportion of the respective first material in the third balloon segment is greater or less than the proportion of the second material.

[0048] In some examples, the first line 302 may represent the behavior of a first segment 406 within the balloon 400 of FIG. 5, and the third line 305 may represent the behavior of a segment 405 within the balloon 400 (a smaller section of a second segment 408, further described below with reference to FIGS. 5 and 6).

[0049] In some examples, the first line 302 may represent the behavior of the first segment 556b in the balloon 550 of FIG. 8, the second line 304 may represent the behavior of the segment 564 (a smaller section of the second segment 558b) in the balloon 550, and the third line 305 may represent the behavior of the first segment 556a in the balloon 550.

[0050] 5 and 6 show a first exemplary balloon 400 that includes an axially extending circumferential segment (first segment 406) that is configured to rupture or rupture before the remainder of the balloon 400 (e.g., when the balloon reaches a threshold inflation pressure), such that the balloon 400 will rupture axially (e.g., along the axially extending segment). In this manner, the balloon 400 may be comprised of stronger and weaker circumferential segments (or circumferential segments that are more and less resistant to increasing pressure from the inflation fluid), such that the weaker segments will rupture before the stronger segments.

[0051] The balloon 400 includes a first portion 402 having a first durometer and a second portion 404 having a second durometer, the second durometer being higher than the first durometer (FIG. 5). As such, the first portion 402 is more compliant (and therefore may be configured to stretch more in response to an increase in inflation pressure) than the second portion 404. In some embodiments, the first portion 402 can include a first material (the first lower durometer and higher compliant material of the first line 302 in FIG. 4) and the second portion 404 can include a second material (the second higher durometer and lower compliant material of the second line 304 in FIG. 4). As discussed above, the first material may have a lower durometer and higher compliance than the second material.

[0052] Figure 5 shows a cross-section of a balloon 400 taken along section AA of Figure 6. The balloon 400 has an annular cross-section with a balloon wall thickness 410 extending between an inner circumferential surface 412 and an outer circumferential surface 414 of the balloon 400. The inner circumferential surface 412 defines a cavity 413 configured to receive an inflation fluid when mounted onto the shaft of a balloon catheter. In Figure 5 and additional cross-sectional views of figures described herein, as shown, the diameter of the cavity and the balloon wall thickness 410 relative to the outer diameter of the balloon may be exaggerated (larger than actual) for illustrative purposes to clearly show the different layers of the balloon.

[0053] In some embodiments, balloon 400 can be a multi-layer balloon (FIG. 5) where first portion 402 forms a first layer 418 and a second layer 420 (e.g., of a first material) and second portion 404 forms a third layer 422 (e.g., of a second material) between first layer 418 and second layer 420. The different layers of balloon 400 can be formed using a multi-layer extrusion process, as further described below with reference to FIG.

[0054] As shown in Figure 5, the balloon 400 comprises a first segment 406 that extends circumferentially around a portion of the circumference of the balloon 400 and a second segment 408 that extends circumferentially around another portion of the circumference of the balloon (as indicated by the arrow representing the arc length 409 of the second segment 408 in Figure 5). Thus, the first segment 406 and the second segment 408 may be referred to herein as circumferential segments. In some embodiments, the first segment 406 and the second segment 408 make up the entire circumference of the balloon 400, as shown in Figure 5.

[0055] As used herein, a "circumferential segment" of a balloon may refer to a segment of the balloon that extends circumferentially around a portion (e.g., only a portion) of the circumference of the balloon. A circumferential segment may extend axially along the length of the balloon and extend radially through the thickness of the balloon. As such, a cross-section of the balloon through a plane perpendicular to the axial direction may be annular, such that the circumferential segment may form an annular wedge or cross-section.

[0056] As shown in the embodiment of FIG. 5, the first segment 406 comprises only the first portion 402 (e.g., a lower durometer material). For example, the first segment 406 can comprise one or more layers of the first portion (or first material) and can extend throughout the thickness 410 of the balloon 400 from the inner circumferential surface 412 to the outer circumferential surface 414 of the balloon 400. Thus, in some embodiments, the first segment 406 can include only the first material having a lower durometer. However, in some embodiments, the first segment 406 can be comprised of additional materials (in addition to the first material) and / or discontinuities in the second material or portions of the second material that are thinner than the remainder of the balloon, as described further below with reference to FIGS. 13-25.

[0057] The first segment 406 is an axially extending segment that extends along the length of the balloon 400 (in the direction of the central longitudinal axis 416 of the balloon 400), but around only a portion of the circumference of the balloon 400 (FIG. 6). The second segment 408 may comprise the remaining portion of the balloon 400 and also extends axially along the length of the balloon (FIG. 6). In the illustrated embodiment, both segments 406, 408 extend axially the entire length of the balloon 400, or at least the entire length of the inflatable portion of the balloon that forms the cavity.

[0058] In some embodiments, the first segment 406 extends axially for at least a majority of the length of the balloon.

[0059] In some embodiments, the first segment 406 extends less than the majority of the length of the balloon.

[0060] The axial length of each segment formed from the more compliant material may vary; for example, each such segment may extend axially for a majority of the length of the balloon, at least a majority of the length of the balloon, or less than the entire length of the balloon (or at least the entire length of the inflatable portion of the balloon).

[0061] The second segment 408 can span a majority of the circumference, or arc length 409, of the balloon 400, as shown in FIG. 5. The arc length 409 of the second segment 408 is greater than the arc length 411 of the first segment 406. The second segment 408 can include a portion of the first portion 402 (first layer 418 and second layer 420) and the second portion 404 (third layer 422). For example, across the thickness 410, the second segment 408 includes the third layer 422 of the second portion 404 disposed between the first layer 418 and the second layer 420 of the first portion 402. In this manner, the second segment 408 can include a band or layer of the second portion 404 (e.g., a second material) embedded within the first portion 402 (e.g., a first material). Because the second material of the second portion 404 is configured to burst at a higher pressure than the first material, as shown in the example graph 300 of FIG. 4, the second segment 408 may be stronger or more resistant to bursting or rupturing than the first segment 406.

[0062] As a result, the first segment 406 (which does not include any of the second portions 404 having a higher durometer in the embodiment of FIGS. 5 and 6) can be configured to rupture before the second segment 408. Because the first segment 406 extends axially along the length of the balloon 400 and extends around only a portion of the circumference of the balloon (FIG. 6), the balloon 400 is configured to rupture axially along the first segment 406. The second segments 408 disposed on either side (circumferentially) of the first segment 406 can prevent the balloon 400 from tearing laterally across the balloon. In this way, the balloon 400 can be more easily retrieved and removed with a delivery device (or another balloon catheter) if it experiences a rupture.

[0063] The first segment 406 of the balloon 400 is configured as a "weaker" circumferential segment (compared to the remainder of the balloon, or to the second segment 408) that is configured to rupture relative to or at a lower pressure than the remainder of the balloon. In other words, the first segment 406 can be formed by a discontinuity in the second portion 404 (circumferentially) having a higher durometer. Such a lower durometer (or weaker) circumferential segment (or segments) of the balloon can be created in other ways, such as by varying the placement of portions of different durometers within the balloon. Additional examples of balloons having circumferential segments configured to rupture (and rupture axially) prior to the remaining circumferential segments of the balloon are described below with reference to FIGS. 7-25.

[0064] 7 and 8 show examples of balloons having multiple circumferential segments configured to rupture (and axially rupture) prior to the remainder of the balloon. For example, as shown in FIG. 7, balloon 500 may include a first portion 502 having a first durometer (and a first compliance) and a second portion 504 having a second durometer (and a second compliance), the second durometer being greater than the first durometer (similar to that described above for first portion 402 and second portion 404). In some examples, first portion 502 can include a first material (as described above for first portion 402) and second portion 504 can include a second material (as described above for second portion 404).

[0065] In some embodiments, first portion 502 may include a different first material or combination of first materials and second portion 504 may include a different second material or combination of second materials, where the second material of second portion 504 has a higher durometer than the first material of first portion 502.

[0066] The balloon 500 can be circumferentially comprised of a plurality of (two shown in FIG. 7 ) first segments 506a and 506b (circumferential segments) that comprise the first portion 502 and form a discontinuity in the second portion 504. The balloon 500 further comprises a plurality of circumferential second segments 508a and 508b that comprise the first portion 502 and the second portion 504. For example, each of the second segments 508a and 508b can comprise a section of the second portion 504 (having a higher second durometer) embedded within the first portion 502 (having a lower first durometer). In other words, each of the second segments 508a and 508b can be formed by inner and outer layers of the first portion 502 (e.g., of a first material) and a central layer of the second portion 504 (e.g., of a second material).

[0067] Similar to first segment 406 of balloon 400 (FIGS. 5-6), first segments 506a and 506b may be axially extending circumferential segments configured to rupture (axially) prior to second segments 508a and 508b due to second segments 508a and 508b including second portion 504 (which may include a higher durometer material).

[0068] In some embodiments, the height 510 (defined circumferentially) of the lower durometer first segments 506a and 506b may be selected based on the materials of the first and second portions 502, 504 and / or the desired expansion pressure at which rupture occurs in the first segments 506a and 506b. For example, the height 510 may be less than or greater than that shown in FIG. 7. Additionally, in some embodiments, the heights 510 of the first segments 506a and 506b may be the same or different from one another.

[0069] 8 illustrates an exemplary balloon 550 comprising a first portion 552 having a first durometer and a second portion 554 having a second durometer, the second durometer being greater than the first durometer (similar to that described above for first portion 402 and second portion 404). Balloon 550 comprises first portion 552 (and in the case of first segment 556a, also second portion 554) and can comprise multiple (two shown in FIG. 8) first segments 556a and 556b in the circumferential direction. As an example, first segment 556a comprises a section or layer of first portion 552 (having a smaller first durometer) embedded within second portion 554 (having a larger second durometer), and first segment 556b comprises only one or more layers of first portion 552 (and does not include any of second portion 554). In this manner, the first segments 556 a and 556 b can form a discontinuity or gap in the circumferential second portion 554 of the balloon 550 .

[0070] The balloon 550 can further include a plurality of second segments 558a and 558b, each disposed between the two first segments 556a and 556b. The second segments 558a and 558b can include sections of the second portion 554. Thus, the second segments 558a and 558b can include one or more layers of material of the second portion 554, and the first segments 556a and 556b can include either one or more layers of material of the first portion 552 (first segments 556b), or a layer of material of the first portion 552 and one or more layers of material of the second portion 554 (first segments 556a).

[0071] Similar to first segment 406 of balloon 400 (FIGS. 5-6), first segments 556a and 556b may be axially extending circumferential segments configured to rupture (axially) before the remainder of the balloon (second segments 558a and 558b) because first segments 556a and 556b have a higher compliance (from the first durometer of the lower portion of first portion 552 contained in first segments 556a and 556b) than second segments 558a and 558b. For example, first segments 556a and 556b may be designed to stretch more with increasing inflation pressure and rupture at a lower inflation pressure than the remainder of balloon 550 by introducing the lower durometer material of first portion 552 into first segments 556a and 556b while the remainder of the balloon includes the higher durometer material of second portion 554.

[0072] In some embodiments, the heights 560a and 560b (defined circumferentially) of the first segments 556a and 556b having the lower durometer, respectively, may be selected based on the materials of the first portion 552 and the second portion 554 and / or the desired expansion pressure at which the first segments 556a and 556b will rupture. For example, the heights 560a and 560b may be less than or greater than that shown in FIG. 8. Additionally, in some embodiments, the heights 560a and 560b of the first segments 556a and 556b, respectively, may be the same as or different from one another.

[0073] 9A-9C show an example of a balloon 600 having a circumferential segment extending axially of the balloon that is configured to rupture axially prior to the remainder of the balloon 600. The balloon 600 can include a first portion 602 having a first durometer and a second portion 604 having a second durometer, the second durometer being greater than the first durometer. In some examples, the first portion 602 can include a first material having a first durometer (same or similar to first portions 402, 502, and / or 552) and the second portion 604 can include a second material having a second durometer (same or similar to second portions 404, 504, and / or 554).

[0074] The balloon 600 can include a first circumferential segment 606 comprising a first portion 602 embedded within a second portion 604. A second circumferential segment 608 can comprise the remainder of the balloon 600 and comprises only the second portion 604. The first portion 602 (which can include a first material having a lower first durometer) can extend partially through or through the entire thickness 610 of the wall of the balloon 600. In this manner, the first portion 602 of the first circumferential segment 606 can be configured to stretch more with increasing inflation pressure than the second portion 604 as the balloon 600 fills with inflation fluid (FIGS. 9A-9C).

[0075] More specifically, Figures 9A-9C show how, as the balloon is inflated with inflation fluid, the lower durometer first material of first portion 602 (which has a higher compliance compared to second portion 604) stretches or expands circumferentially more than the higher durometer material of second portion 604, thereby causing an increase in inflation pressure. The increase in inflation pressure 612 on balloon 600 is indicated in Figures 9B and 9C by the arrow centered within balloon 600.

[0076] 9B and 9C, dashed vertical line 614 and first box 616 diagrammatically illustrate how first portion 602, having a lower durometer, grows or expands circumferentially as inflation pressure 612 increases and the outer diameter of balloon 600 increases. Similarly, second box 618 represents a section of second portion 604 and diagrammatically illustrates how second portion 604 increases in size as inflation pressure 612 increases and the outer diameter of balloon 600 increases.

[0077] As the diameter of the balloon 600 increases under increasing inflation pressure 612, the first portion 602 of the first circumferential segment 606 grows larger than the second portion 604 of the second circumferential segment 608 (e.g., because the first material of the first portion 602 is more compliant and has a lower durometer than the second portion 604). The first portion 602 grows and thins more quickly as the inflation pressure 612 increases than the remainder of the balloon 600. Thus, the first circumferential segment 606 is configured to rupture first, prior to the second circumferential segment 608 (similar to that described above with reference to graph 300 of FIG. 4), when a threshold inflation pressure is reached at which rupture occurs for the material of the first portion 602.

[0078] 10-12 show cross sections of exemplary balloons 700, 720, and 740 including a first portion 702 having a first durometer and a second portion 704 having a second durometer greater than the first durometer. In some embodiments, the first portion 702 can include a first material having a lower first durometer and the second portion 704 can include a second material having a higher second durometer (compared to the first durometer). The first portion 702 can be the same as or similar to other first portions (e.g., first portion 404) described herein, and the second portion 704 can be the same as or similar to other second portions (e.g., second portion 404) described herein.

[0079] It should be noted that, for simplicity, all of Figures 10-24 are depicted as including first and second portions 702, 704 of various configurations (e.g., shape and size). In these embodiments, first and second portions 702, 704 may have a lower durometer (and higher compliance) and a higher durometer (and lower compliance), respectively, relative to one another. However, the specific materials resulting in the lower durometer first portion 702 and the higher durometer second portion 704 may differ between different balloon embodiments (of the different Figures 10-24).

[0080] 10-12, second portion 704 can be configured as a partial ring or discontinuous layer within or surrounded by first portion 702. First portion 702 can be configured as one or more circumferentially extending layers. In this manner, balloons 700, 720, and 740 of FIGS. 10-12 can be multi-layer balloons formed from multiple layer extrusions of different durometer materials (first portion 702 and second portion 704).

[0081] The balloons 700, 720, and 740 shown in FIGS. 10-12 may have one or more discontinuities 710 in the second portion 704. The discontinuities 710 may be complete or partial gaps or tears in the circumferentially extending second portion 704. These discontinuities 710 break the circumferential continuity of the second portion 704 having a higher durometer, thereby creating a relatively weaker first circumferential segment 706 that is configured to rupture under increased inflation pressure before the remainder of the balloon (e.g., a second circumferential segment 708 of the balloon comprising an unbroken section of the second portion 704). As described herein, the first circumferential segment 706 and the second circumferential segment 708 may extend axially along the length of the balloon.

[0082] As an example, the balloon 700 of FIG. 10 includes two discontinuities 710 configured as complete gaps or tears of varying height 712 (defined circumferentially) in the second portion 704 that create the first circumferential segment 706.

[0083] In some embodiments, the balloon 700 can include more or less than two discontinuities 710 (eg, only one or three), which can have the same or different heights 712 from one another.

[0084] In this manner, the balloon 700 can include a first portion 702 (e.g., only one or more layers of material of the first portion 702 across the thickness of the balloon) and a plurality of first circumferential segments 706 configured to rupture axially prior to the second circumferential segments 708.

[0085] 11, the balloon 720 includes two discontinuities 710 configured as axially extending gaps or notches that extend partially or completely through the second portion 704 to form the first circumferential segment 706. The discontinuities 710 in the balloon 720 are circumferentially spaced apart from one another.

[0086] In some embodiments, the balloon 720 can include more or less than two discontinuities 710 (e.g., only one or three) and / or the discontinuities 710 can vary in depth (radially to the second portion 704) and / or height 712.

[0087] As a result, balloon 720 comprises a plurality of first circumferential segments 706 that constitute first portion 702 and none or only a portion of the thickness of second portion 704. In this manner, first circumferential segments 706 form points of relative weakness in balloon 720 that are configured to rupture axially prior to second circumferential segments 708.

[0088] The balloon 740 of FIG. 12 includes two discontinuities 710 configured as complete gaps or breaks of varying height 712 in the second portion 704 that create the first circumferential segment 706 .

[0089] In some embodiments, the balloon 740 can include more or less than two discontinuities 710 (eg, only one or three), which can have the same or different heights 712 from one another.

[0090] In this manner, balloon 700 can include a first portion 702 (only one or more layers of material of first portion 702 across the thickness of the balloon) and include a plurality of first circumferential segments 706 configured to rupture axially prior to second circumferential segments 708. Additionally, Figure 12 illustrates an embodiment of second portion 704 configured as a rectangular or square ring, rather than the circular ring shown in Figures 10 and 11.

[0091] In some embodiments, the rings or layers of material in second portion 704 can be in different shapes that extend circumferentially around balloon 740, such as a zigzag pattern, a wave pattern, a hexagon, or the like.

[0092] 13-24 show cross sections of additional embodiments of a balloon comprising a first portion 702 having a first durometer (which may include a first material or another material or a combination of relatively low durometer materials) and a second portion 704 having a second durometer (which may include a second material or another material or a combination of relatively high durometer materials), where the second durometer is greater than the first durometer. In the different embodiments of FIGS. 13-24, the shape, arrangement, and relative sizes of the first portion 702 and the second portion 704 within the balloon may vary.

[0093] 13 and 14 show examples of balloons 800 and 810, respectively, having discontinuities 802 created by longitudinally extending ends 804 of portions 704 radially overlapping one another and / or tears in adjacently disposed second portions 704. These discontinuities 802 extending axially along the length of the balloon can form a first circumferential segment 806 (shown in brackets between dashed lines) that is configured to rupture before the remainder of the balloon under increasing inflation pressure (e.g., before a second circumferential segment 808 where the second portion 704 has no tears in the first portion 702). Thus, the first circumferential segment 806 forms a relative "weaker" point in the balloon due to the interruption or discontinuity 802 in the material in the second portion 704 (which has a lower compliance and a higher durometer).

[0094] In some embodiments, as shown in the exemplary balloon 800 of FIG. 13, the end 804 of the second portion 704 of the first circumferential segment 806 can be positioned near the inner circumferential surface 812 of the balloon 800.

[0095] In some embodiments, as shown in the exemplary balloon 810 of FIG. 14, the end 804 of the second portion 704 of the first circumferential segment 806 can be positioned near the outer circumferential surface 814 of the balloon 810.

[0096] In some embodiments, end 804 of discontinuity 802 can be approximately centered radially between inner circumferential surface 812 and outer circumferential surface 814 .

[0097] In some embodiments, ends 804 of discontinuities 802 may each extend circumferentially further and overlap one another by a greater amount than shown in FIGS.

[0098] In some embodiments, ends 804 of discontinuities 802 can be spaced apart from one another to circumferentially define gaps that are completely filled by first portion 702. Additionally, in some embodiments, thickness 816 of ends 804 of discontinuities 802 can be less than the remainder of second portion 704.

[0099] 15 illustrates an exemplary cross-section of a balloon 820 in which a change in compliance or durometer in the circumferential direction can be created by varying the number of layers of the second portion 704 within the first portion 702 of the balloon 820. For example, the second portion 704 of the balloon 820 can be formed as two layers including a first layer 822 and a second layer 824, with the second layer 824 disposed radially outward of the first layer 822. In some embodiments, the first layer 822 can be disposed adjacent to the inner circumferential surface 812 of the balloon 820 (which can form the inner surface 812 as shown in the illustrated embodiment), and the second layer 824 can extend radially outward from a first side of the first layer 822 toward the outer circumferential surface 814 of the balloon 820. In this manner, the central axis of the second layer 824 can be offset from the central axis of the first layer 822 and the balloon. A first circumferential segment 826 of the balloon 820 may include only the first layer 822 of the second portion 704, with the remainder of the first circumferential segment 826 being comprised of one or more layers of the first portion 702 (e.g., multiple layers of the first portion 702). A second circumferential segment 828 of the balloon 820 may include both the first layer 822 and the second layer 824 of the second portion 704 within the first portion 702 (e.g., the second circumferential segment 828 may be formed by multiple layers of both the first portion 702 and the second portion 704, or at least two layers of each of the first portion 702 and the second portion 704). Thus, the first circumferential segment 826 may be relatively weaker and more compliant, thereby rupturing under increasing inflation pressure before the second circumferential segment 828.

[0100] 16 illustrates a cross-section of an exemplary balloon 830 in which circumferential compliance or durometer variations can be created by varying the thickness (or radial amount of material) of the second portion 704 that extends circumferentially around the circumference of the balloon 830. For example, the second portion 704 can include one or more thinner sections 840 having a first thickness 832 and one or more thicker sections 842 having a second thickness 834. As such, the balloon 830 can include one or more first circumferential segments 836 that include the thinner sections 840 of the second portion 704 and one or more second circumferential segments 838 that include the thicker sections 842 of the second portion 704. As such, the one or more first circumferential segments 836 can have a higher compliance than the one or more second circumferential segments 838 due to the fact that the first circumferential segment 836 includes the material having the higher compliance of the first portion 702 and the material having the lower compliance of the second portion 704 along the radial direction as compared to the second circumferential segment 838. In this manner, the first circumferential segment 836 can be configured to rupture under increasing inflation pressure before one or more of the second circumferential segments 838 .

[0101] 17 illustrates a cross-section of an exemplary balloon 850 that is similar to balloon 830 of FIG. 16, but balloon 850 further includes one or more discontinuities 710 (or gaps or crevices) in second portion 704. In some embodiments, discontinuities 710 can be present in thicker section 842.

[0102] In some embodiments, discontinuity 710 can be present in thinner section 840 .

[0103] In some embodiments, the discontinuities may have a height that varies circumferentially. As discussed above with reference to Figures 10-12, these discontinuities 710 may form one or more first segments 852 that include a first portion 702 having a smaller durometer (and, in some embodiments, none of the second portions 704). Thus, the first segments 852 may be configured to rupture axially under increasing inflation pressure before the remainder of the balloon 850.

[0104] FIG. 18 illustrates a cross-section of an exemplary balloon 860 in which a discontinuity 710 in the second portion 704 is created by a varying height layer 862 of the first portion 702 extending into the second portion 704. In the example of FIG. 18, the second portion 704 is disposed adjacent to the outer circumferential surface 814 of the balloon 860, thereby forming the outermost layer of the balloon 860, while the first portion 702 forms the innermost layer of the balloon 860. FIG. 18 illustrates an example of how the shape of the discontinuity 710 can vary (e.g., can be triangular instead of rectangular or square). A first circumferential segment 864 configured to rupture axially under increasing inflation pressure can be formed in the region of the discontinuity 710 prior to a second circumferential segment 866 of the balloon 860.

[0105] 19 and 20 show cross sections of example balloons 870 and 880, respectively, comprising multiple circumferentially extending layers or portions including a first portion 702 configured as a first layer 872 and a second layer 874, a third portion 876 configured as a third layer 878, and a second portion 704 configured as a fourth layer 882. In some embodiments, the third portion 876 can have a third durometer that is different (lesser or greater) than the durometers of the first portion 702 and the second portion 704. Additionally, in some embodiments, the third portion 876 can include a third material that is different (having a third durometer) from the first material of the first portion 702 and the second material of the second portion 704.

[0106] The layers of a balloon may be concentric, as shown in balloon 880 in FIG. 20, or non-concentric, as shown in balloon 870 in FIG.

[0107] In some embodiments, one or more first circumferential segments 884 having greater compliance than the remainder of the balloon can be formed by gaps or discontinuities in one or more layers of the balloon. For example, balloon 870 in FIG. 19 has a first discontinuity 886 in third layer 878 and a second discontinuity 888 in fourth layer 882 that are filled by first portion 702.

[0108] In some examples, the discontinuities can be filled with an additional material or portion having a lower durometer and higher compliance relative to the layer in which the discontinuity is located, thereby forming a first circumferential segment 884. For example, balloon 880 of FIG. 20 can have a first discontinuity 881 in third layer 878 filled with fourth portion 883 (or fourth material) and a second discontinuity 885 in fourth layer 882 filled with fourth portion 883. In some examples, the materials filling first discontinuity 881 and second discontinuity 885 have a durometer less than the durometer of the layer in which they are located and can be different materials.

[0109] 21 illustrates a cross section of an exemplary balloon 890 including one or more (two in FIG. 21 ) discontinuities 892 in second portion 704 filled with an additional third portion 894. Third portion 894 can include a third material having a third durometer. In some embodiments, the third durometer is lower than the second durometer of second portion 704. In some embodiments, the third durometer can be lower than the first durometer of first portion 702 and the second durometer of second portion 704.

[0110] In some embodiments, the third durometer can be higher than the first durometer of first portion 702 and lower than the second durometer of second portion 704 .

[0111] In this manner, a first circumferential segment 896 configured to rupture axially can be created before the remainder of the balloon 890 (or the remaining second circumferential segment 898) can be created in the area of ​​the third portion 894.

[0112] In some embodiments, the third portion 894 can fill only the discontinuity 892 in the second portion 704 (shown in the lower portion of FIG. 21 ). In some embodiments, the third portion 894 can fill the discontinuity 892 and extend further from the discontinuity toward the inner periphery 812 and / or the outer periphery 814 (shown in the upper portion of FIG. 21 ).

[0113] FIG 22 illustrates a cross-section of an exemplary balloon 900 similar to balloon 400 of FIGS. 5 and 6 and balloon 700 of FIG. 10, but instead of a perfectly circular annular second portion 704, second portion 704 is an elliptical or elliptical layer. Additionally, as shown in FIG 22, second portion 704 may have one or more discontinuities 710 that are filled by first portion 702. In this manner, FIG 22 illustrates an example of a balloon 900 in which one or more circumferentially extending layers of the balloon (e.g., second portion 704) are not circular but have a different shape (also shown in balloon 740 of FIG. 12).

[0114] 23 illustrates a cross-section of an exemplary balloon 910 that includes a third portion 912 (or portion) between the first portion 702 (first layer) and the second portion 704 (second layer). In some embodiments, the third portion 912 can be configured as a tie layer that can help support or secure the layers of the first portion 702 and the second portion 704 to one another. For example, the third portion 912 can include an additional third material (different from the material of the first portion 702 and the second portion 704) that helps secure or bond the layers of the first portion 702 and the second portion 704 to one another.

[0115] Further, in some embodiments, the balloon 910 can include a discontinuity (gap or breach) in each of the first portion 702, the second portion 704, and the third portion 912 that is filled by the fourth portion 914. The fourth portion 914 can include a fourth material that is different from the first material of the first portion 702 and the second material of the second portion 704. In some embodiments, the fourth material of the fourth portion 914 can have a lower durometer than the second portion 704. In some embodiments, the fourth material of the fourth portion 914 can have a lower durometer than the second portion 704 and the first portion 702. In this manner, a first circumferential segment 916 is formed that has a higher compliance than the remainder of the balloon 910 and is configured to rupture axially before the second circumferential portion 918 of the balloon 900 is formed in the region of the fourth portion 914.

[0116] 24, the third portion 912 can be comprised of a layer of a third material disposed within the first portion 702 radially spaced from the second portion 704. For example, the balloon 920 can comprise (from the inner circumferential surface 812 to the outer circumferential surface 814) a first layer 922 of the first portion 702, a layer 924 of the second portion 704, a second layer 926 of the first portion 702, a layer of the third portion 912, and finally a third layer 928 of the first portion 702.

[0117] Additionally, balloon 920 can include one or more discontinuities 710 filled by first portion 702 (FIG. 24). In this manner, a first circumferential segment 930 is formed that has greater compliance than the remainder of balloon 920 and is configured to rupture axially before a second circumferential section 932 of balloon 920 is formed in the region of discontinuities 710.

[0118] 25 is a flow chart of a method 1000 for forming a balloon having one or more circumferential segments having a higher compliance (and / or lower durometer) than the remainder of the balloon, such that when the balloon is under pressure from an inflation fluid introduced into the balloon, the one or more circumferential segments are configured to rupture axially before the remainder of the balloon. For example, method 1000 can be used to form any of the balloons described herein. In some embodiments, the balloon formed by method 1000 is a multi-layer balloon comprising multiple circumferentially extending portions or layers having different durometers. In some embodiments, the portions or layers of the balloon having a higher durometer (and lower compliance) can comprise one or more discontinuities therein filled with a portion or material having a lower compliance, thereby forming one or more circumferential segments having a higher compliance that are configured to rupture at a lower inflation pressure than the remainder of the balloon.

[0119] Method 1000 begins as 1002 and includes selecting one or more materials and dies for extrusion of a multi-layer tube to form a balloon having one or more selected discontinuities and / or segments having higher compliance (e.g., first segment 406 of balloon 400 of FIGS. 5 and 6). As discussed above, various portions of the balloons described herein can have different compliances and durometers formed by materials of different durometers. By way of example, such as for balloon 400 of FIGS. 5 and 6, a first material can be selected having a first durometer (for first portion 402) and a second material can be selected having a second durometer (for second portion 404), the second durometer being greater than the first durometer. The die used in the tube extrusion process can be selected to be configured to form the particular layers (portions) and discontinuities (or higher compliance circumferential segments) of the selected balloon.

[0120] At 1004, the method 1000 includes extruding a multi-layer tube having selected discontinuities and / or circumferential segments having higher compliance using an extrusion system including the selected die and materials. In some embodiments, the extrusion system can include multiple (e.g., two or more) material co-extrusion heads and a die having multiple flow channels configured to form the designated layers of the selected balloon. Using the extrusion system, the selected multi-layer tube is formed, which may have a cross-section similar to one of the balloons described herein with reference to FIGS. 5-24.

[0121] At 1006, the method 1000 includes forming a balloon from the extruded multi-layer tube (e.g., via blow molding) and attaching the formed balloon to the shaft of a balloon catheter. In some examples, the balloon catheter can be a delivery device for a radially expandable prosthetic medical device, such as the delivery device shown in FIG.

[0122] In some embodiments, axially extending circumferential segments having higher compliance and / or lower durometer that are configured to rupture axially along the balloon prior to the remainder of the balloon (or circumferential segments having lower compliance and / or higher durometer) can be formed by varying the wall thickness of the balloon.

[0123] In some embodiments, as shown in FIGS. 26 and 27, one or more reinforcing elements 1102 can be disposed on the inner circumferential surface 1104 of an extruded balloon tube 1100 (FIG. 26) and a balloon 1101 (FIG. 27) formed from the balloon tube 1100.

[0124] In some embodiments, one or more reinforcing elements 1102 may be disposed on the outer circumferential surface of the extruded balloon tube 1100 and may be disposed on a balloon 1101 formed from the balloon tube 1100.

[0125] In some embodiments, one or more reinforcing elements 1102 may be disposed on both the inner circumferential surface 1104 and the outer circumferential surface of the extruded balloon tube 1100 and may be disposed on a balloon 1101 formed from the balloon tube 1100.

[0126] Each reinforcing element 1102 extends axially (into the page in Figures 26 and 27) along the balloon tube 1100 and balloon 1101. One or more reinforcing elements 1102 can provide a radially increasing thickness to the balloon tube 1100, and to the balloon 1101 formed therefrom, at selected circumferential locations along the axial length of the balloon. For example, as shown in Figure 26 (showing a cross-sectional view of the balloon tube 1100 prior to formation into a balloon 1101), the balloon tube 1100 has a first thickness 1106 in segments of the balloon tube that do not include reinforcing elements 1102. Additionally, in segments of the balloon tube that include reinforcing elements 1102, the balloon tube 1100 has a second thickness 1108 that is greater than the first thickness 1106. Segments of the balloon that do not include reinforcing elements 1102 can have a higher compliance than segments of the balloon that include reinforcing elements.

[0127] Thus, the reinforcing element 1102 can cause the balloon 1101 to burst axially along the length of the balloon, rather than laterally (across the balloon). For example, the reinforcing element 1102 can prevent the balloon from bursting laterally across the balloon under increasing pressure from an inflation fluid introduced into the interior cavity 1110 of the balloon.

[0128] In some embodiments, the reinforcing elements 1102 can be configured as ribs that are radially spaced from the inner surface 1104 and extend inward toward a central longitudinal axis of the balloon tube 1100 and balloon 1101.

[0129] 27 shows a cross section of a portion of a formed balloon 1101 (formed from balloon tube 1100). In some embodiments, the balloon 1101 can include a first material and the reinforcing element 1102 can include a second material that is different from the first material. In some embodiments, the second material can include a material with a higher durometer than the first material. In some embodiments, the balloon 1101 can include a first material and the reinforcing element 1102 can include the same first material.

[0130] 26, a balloon tube 1100, and balloon 1101 formed therefrom, can include a plurality of reinforcing elements 1102 spaced apart circumferentially about an inner periphery 1104. The spacing between adjacent reinforcing elements can be uniform or irregular.

[0131] In some embodiments, each reinforcing element 1102 can extend axially along the entire length of the balloon 1101.

[0132] In some embodiments, the reinforcing element 1102 can have one or more varying lengths extending axially along at least a majority of the length of the balloon 1101 .

[0133] The balloons described herein can be used in a variety of medical catheters that are configured to mount the balloon on a distal end portion of the medical catheter and inflate the balloon during a medical procedure (and thus can be referred to as a balloon catheter). Examples of such balloon catheters include delivery devices for radially expandable prosthetic medical devices (such as the delivery device 100 of FIG. 2), balloon catheters for angioplasty, and the like. Balloon catheters including the balloons disclosed herein can be used to implant any of a variety of medical devices (e.g., prosthetic heart valves, stents, stent grafts, etc.) or can be used to perform other medical procedures that do not involve the implantation of a medical device, such as a valvuloplasty procedure.

[0134] delivery technology To implant the prosthetic valve into the native aortic valve via a transfemoral delivery approach, the prosthetic valve is mounted in a radially compressed state along a distal end portion of a delivery device. The prosthetic valve and the distal end portion of the delivery device are inserted into the femoral artery and driven forward into and through the descending aorta, around the aortic arch, and through the ascending aorta. The prosthetic valve is positioned inside the native aortic valve and radially expanded (e.g., by inflating a balloon, by actuating one or more actuators of the delivery device, or by deploying the prosthetic valve from a sheath and allowing the prosthetic valve to self-expand). Alternatively, the prosthetic valve can be implanted inside the native aortic valve in a transapical procedure, in which the prosthetic valve (on the distal end portion of the delivery device) is introduced into the left ventricle through a surgical opening in the chest and the apex of the heart, and the prosthetic valve is positioned inside the native aortic valve. Alternatively, in a transaortic procedure, the prosthetic valve (on the distal end portion of the delivery device) is introduced into the aorta through a surgical incision in the ascending aorta, such as by a partial J sternotomy or a right parasternal minithoracotomy, and then driven forward through the ascending aorta toward the native aortic valve.

[0135] To implant the prosthetic valve inside the native mitral valve via a transseptal delivery approach, the prosthetic valve is mounted in a radially compressed state along the distal end portion of a delivery device. The prosthetic valve and the distal end portion of the delivery device are inserted into the femoral vein and advanced into the inferior vena cava and through the inferior vena cava, into the right atrium, across the atrial septum (through a puncture made in the atrial septum), into the left atrium, and toward the native mitral valve. Alternatively, the prosthetic valve may be implanted inside the native mitral valve in a transapical procedure, whereby the prosthetic valve (on the distal end portion of the delivery device) is introduced into the left ventricle through a surgical opening in the chest and the apex of the heart, and the prosthetic valve is positioned inside the native mitral valve.

[0136] To implant the prosthetic valve inside the native tricuspid valve, the prosthetic valve is mounted in a radially compressed state along the distal end portion of the delivery device. The prosthetic valve and the distal end portion of the delivery device are inserted into the femoral vein and advanced into and through the inferior vena cava into the right atrium, where the prosthetic valve is positioned inside the native tricuspid valve. A similar approach may be used to implant the prosthetic valve inside the native pulmonary valve or pulmonary artery, except the prosthetic valve is advanced through the native tricuspid valve into the right ventricle and toward the pulmonary valve / pulmonary artery.

[0137] Another delivery approach is the transatrial approach, whereby the prosthetic valve (on the distal end portion of the delivery device) is inserted through an incision in the chest and an incision is made through the atrial wall (of the right or left atrium) to access either of the native heart valves. Atrial delivery can also be performed endovascularly, such as from a pulmonary vein. Yet another delivery approach is the transventricular approach, whereby the prosthetic valve (on the distal end portion of the delivery device) is inserted through an incision in the chest and an incision is made through the wall of the right ventricle (typically at or near the base of the heart) to implant the prosthetic valve inside the native tricuspid valve or inside the native pulmonary valve or inside the pulmonary artery.

[0138] In all delivery approaches, the delivery device can be driven forward over a guidewire previously inserted into the patient's vasculature. Moreover, the disclosed delivery approaches are not intended to be limiting. Any of the prosthetic valves disclosed herein can be implanted using any of a variety of delivery procedures and any of a variety of delivery devices known in the art.

[0139] Any of the systems, devices, equipment, etc. herein can be sterilized (e.g., using heat / thermal, pressure, steam, radiation, and / or chemicals, etc.) to ensure that they are safe for use with patients, and any of the methods herein can include sterilization of the associated system, device, equipment, etc. as one of the steps of the method. Examples of heat / thermal sterilization include steam sterilization and autoclaving. Examples of radiation for use in sterilization include, but are not limited to, gamma radiation, ultraviolet radiation, and electron beam. Examples of chemicals for use in sterilization include, but are not limited to, ethylene oxide, hydrogen peroxide, peracetic acid, formaldehyde, and glutaraldehyde. Sterilization with hydrogen peroxide may be performed, for example, using hydrogen peroxide plasma.

[0140] Additional Examples of the Disclosed Technique In view of the above implementations of the disclosed subject matter, the present application discloses additional embodiments, which are listed below. It should be noted that a feature in isolation from an embodiment or two or more features taken in combination, and optionally in combination with one or more features from one or more additional embodiments, are also further embodiments that fall within the disclosure of the present application.

[0141] Example 1. An inflatable balloon for a medical catheter, comprising a first segment having a first compliance and a second segment having a second compliance, the first compliance being greater than the second compliance, the first segment and the second segment extending axially along a length of the balloon, and the first segment configured to axially rupture before the second segment under pressure from an inflation fluid introduced into the balloon.

[0142] Example 2. Any of the Examples herein, particularly the balloon of Example 1, wherein the first segment and the second segment are circumferential segments of the balloon that each extend circumferentially around a different portion of the circumference of the balloon.

[0143] Example 3. Any embodiment herein, particularly the balloon of Example 1 or Example 2, wherein the first segment comprises a first material having a first compliance and a first durometer, and the second segment comprises the first material and a second material having a second durometer greater than the first durometer.

[0144] Example 4. A balloon as described in any of the examples herein, particularly Example 3, wherein the first segment comprises one or more circumferentially extending layers of a first material extending across the thickness of the balloon, and the second segment comprises one or more circumferentially extending layers of the first material and one or more circumferentially extending layers of a second material.

[0145] Example 5. The balloon of any of the embodiments herein, particularly Example 4, wherein the second segment comprises a circumferentially extending layer of a second material disposed between a plurality of circumferentially extending layers of the first material.

[0146] Example 6. Any of the examples herein, particularly the balloon of Example 3, wherein the first segment comprises a circumferentially extending layer of the first material that is more than the second material, and the second segment comprises a circumferentially extending layer of the second material that is more than the first segment.

[0147] Example 7. Any of the embodiments herein, particularly any one of Examples 1-6, wherein the balloon comprises a plurality of first segments having a first compliance and a plurality of second segments having a second compliance, each of the first segments being disposed between two circumferentially adjacent second segments of the balloon.

[0148] Example 8. Any embodiment herein, particularly the balloon of Example 1 or Example 2, wherein the first segment comprises a first material having a first durometer embedded within a second material having a second durometer greater than the first durometer, and the second segment comprises the second material.

[0149] Example 9. Any of the embodiments herein, particularly the balloon of Example 1 or Example 2, wherein the balloon comprises a first circumferentially extending portion comprising a first material having a first durometer and a second circumferentially extending portion comprising a second material having a second durometer, the second durometer being greater than the first durometer, and the first segment being formed by a tear in the second circumferentially extending portion such that a discontinuity is formed in the circumferential direction.

[0150] Example 10. Any of the embodiments herein, particularly the balloon of Example 1 or Example 2, wherein the balloon comprises a first circumferentially extending portion comprising a first material having a first durometer and a second circumferentially extending portion comprising a second material having a second durometer, the second durometer being greater than the first durometer, the second circumferentially extending portion having a varying thickness, the first segment being formed by a thinner section of the second circumferentially extending portion disposed between a thicker section of the second circumferentially extending portion.

[0151] Example 11. Any of the examples herein, particularly Example 1 or Example 2, wherein the second segment comprises axially extending reinforcing elements on the inner surface of the balloon that add thickness to the balloon, and the first segment does not have axially extending reinforcing elements and is thinner than the second segment.

[0152] Example 12. Any of the examples herein, especially the balloon of Example 11, wherein the axially extending reinforcing elements comprise the same material as the remainder of the balloon.

[0153] Example 13. Any of the examples herein, especially the balloon of Example 11, wherein the axially extending reinforcing elements comprise a different material than the remainder of the balloon.

[0154] Example 14. Any of the embodiments herein, particularly the balloon of any one of Examples 1-13, wherein the medical catheter is a delivery device for a radially expandable medical device.

[0155] Example 15. An inflatable balloon for a medical catheter, comprising a first circumferential segment including one or more layers of a first material having a first durometer, one or more layers extending across a thickness of the balloon, and a second circumferential segment including one or more layers of the first material and one or more layers of a second material having a second durometer, the second durometer being greater than the first durometer, the first circumferential segment being configured to axially rupture prior to the second circumferential segment under pressure from an inflation fluid introduced into the balloon.

[0156] Example 16. A balloon as described in any of the examples herein, particularly example 15, wherein the second circumferential segment comprises a layer of a second material radially disposed between two layers of the first material, the first circumferential segment forming a gap in the second material.

[0157] Example 17. The balloon of any of the embodiments herein, especially Example 16, wherein the layer of second material forms an annulus extending axially along the balloon.

[0158] Example 18. The balloon of any of the embodiments herein, especially Example 16, wherein the layer of second material forms one of a rectangular, square, or oval ring extending axially along the balloon.

[0159] Example 19. Any of the balloons herein, particularly any one of Examples 15-18, wherein the arc length of the second circumferential segment is greater than the arc length of the first circumferential segment.

[0160] Example 20. Any of the embodiments herein, particularly any one of Examples 15-19, wherein the balloon has two first circumferential segments including one or more layers of a first material, the one or more layers extending across the thickness of the balloon, and the two first circumferential segments are circumferentially spaced from one another by a second circumferential segment.

[0161] Example 21. Any of the embodiments herein, particularly any one of Examples 16-20, wherein both the first circumferential segment and the second circumferential segment extend axially along the length of the balloon.

[0162] Example 22. The balloon of any of the embodiments herein, particularly any one of Examples 16-21, wherein the medical catheter is a delivery device for a radially expandable medical device, and the balloon is configured to be attached to the shaft of the delivery device.

[0163] Example 23. An inflatable balloon for a medical catheter, the inflatable balloon comprising a first portion having a first durometer, a second portion having a second durometer greater than the first durometer, and a discontinuity in the second portion, the discontinuity extending axially along the length of the balloon.

[0164] Example 24. The balloon of any of the embodiments herein, particularly Example 23, wherein the first portion and the second portion are circumferentially extending layers of the balloon that each extend axially along the length of the balloon.

[0165] Example 25. The balloon of any of the embodiments herein, especially Example 24, wherein the first portion and the second portion are circumferentially extending layers concentric with one another.

[0166] Example 26. The balloon of any of the embodiments herein, especially Example 24, wherein the first portion and the second portion are circumferentially extending layers that are non-concentric with respect to one another.

[0167] Example 27. The balloon of any of the embodiments herein, particularly any one of Examples 23-26, wherein the discontinuity creates a gap in the second portion in the circumferential direction.

[0168] Example 28. The balloon of any of the embodiments herein, especially example 27, wherein the gap in the second portion is filled by the first portion.

[0169] Example 29. The balloon of any of the embodiments herein, particularly example 27, wherein a gap in the second portion is filled by a third portion having a third durometer, the third durometer being less than the second durometer.

[0170] Example 30. Any of the embodiments herein, especially any one of Examples 23-26, wherein the discontinuity extends through the entire thickness of the second portion.

[0171] Example 31. The balloon of any of the embodiments herein, especially any one of Examples 23-26, wherein the discontinuity extends through a portion of the thickness of the second portion.

[0172] Example 32. Any of the embodiments herein, particularly any one of Examples 23-26, wherein the discontinuity is formed by a tear in the second portion, and the ends of the second portion radially overlap.

[0173] Example 33. Any of the embodiments herein, particularly any one of Examples 23-26, wherein the discontinuity is formed by a layer of varying height in the first portion, the height being defined circumferentially around the balloon.

[0174] Example 34. Any of the embodiments herein, particularly any one of Examples 23-33, wherein the discontinuities form circumferential segments that extend axially along the length of the balloon within the balloon and are configured to rupture axially prior to the remainder of the balloon under pressure from an inflation fluid introduced into the balloon.

[0175] Example 35. A balloon catheter comprising a shaft extending from a handle of the balloon catheter and an inflatable balloon attached to the shaft, the balloon comprising a plurality of axially extending circumferential segments having different compliances, the plurality of segments being configured such that a first segment having a higher compliance than a second segment ruptures axially along the balloon prior to the second segment when the balloon is inflated with an inflation fluid.

[0176] Example 36. The balloon catheter of any of the embodiments herein, particularly example 35, wherein the first segment and the second segment extend circumferentially around different portions of the circumference of the balloon.

[0177] Example 37. A balloon catheter of any of the embodiments herein, particularly Example 35 or Example 36, wherein the first segment comprises a first material having a first durometer and the second segment comprises the first material and a second material having a second durometer greater than the first durometer.

[0178] Example 38. A balloon catheter as described in any of the examples herein, particularly example 37, wherein the first segment includes multiple circumferentially extending layers of only the first material and the second segment includes one or more circumferentially extending layers of the first material and one or more circumferentially extending layers of the second material.

[0179] Example 39. Any of the examples herein, particularly example 38, of the balloon catheter, wherein the second segment includes one circumferentially extending layer of a second material disposed between a first circumferentially extending layer and a second circumferentially extending layer of the first material.

[0180] Example 40. A balloon catheter as described in any of the examples herein, particularly example 37, wherein the first segment comprises multiple circumferentially extending layers of a first material and a single circumferentially extending layer of a second material, and the second segment comprises multiple circumferentially extending layers of the first material and at least two circumferentially extending layers of the second material.

[0181] Example 41. A balloon catheter according to any one of Examples 35 to 40, wherein the balloon comprises a plurality of first segments having a higher compliance and a plurality of second segments having a lower compliance than the plurality of first segments, and each of the first segments is disposed between two circumferentially adjacent second segments of the balloon.

[0182] Example 42. A balloon catheter of any of the embodiments herein, particularly Example 35 or Example 36, wherein the first segment comprises a first material having a first durometer embedded within a second material having a second durometer greater than the first durometer, and the second segment comprises the second material.

[0183] Example 43. A balloon catheter of any of the embodiments herein, particularly Example 35 or Example 36, wherein the balloon comprises a first circumferentially extending portion comprising a first material having a first durometer and a second circumferentially extending portion comprising a second material having a second durometer, the second durometer being greater than the first durometer, and the first segment being formed by a tear in the second circumferentially extending portion such that a discontinuity is formed in the circumferential direction.

[0184] Example 44. Any of the embodiments herein, particularly example 35 or example 36, wherein the balloon comprises a first circumferentially extending portion comprising a first material having a first durometer and a second circumferentially extending portion comprising a second material having a second durometer, the second durometer being greater than the first durometer, the second circumferentially extending portion varying in thickness circumferentially, and the first segment being formed by a thinner section of the second circumferentially extending portion disposed between adjacent thicker sections of the second circumferentially extending portion.

[0185] Example 45. A balloon catheter of any of the embodiments herein, particularly Example 35 or Example 36, wherein the second segment has axially extending reinforcing elements on the inner surface of the balloon that add thickness to the balloon, and the first segment does not have axially extending reinforcing elements and is thinner than the second segment.

[0186] Example 46 The balloon catheter of any embodiment herein, particularly any one of Examples 35-44, wherein the balloon catheter is a delivery device for a radially expandable prosthetic medical device.

[0187] Example 47. An inflatable balloon for a medical catheter, the inflatable balloon having an inner surface configured to contact a fluid used to inflate the balloon, and one or more reinforcing elements disposed on the inner surface, each reinforcing element extending axially along the balloon.

[0188] Example 48. The balloon of any of the embodiments herein, particularly example 47, wherein the one or more reinforcing elements include two or more reinforcing elements spaced apart from one another circumferentially about the balloon.

[0189] Example 49. Any of the embodiments herein, particularly the balloon of Example 47 or Example 48, wherein each reinforcing element of the one or more reinforcing elements is configured as a rib that increases the thickness of the balloon at selected circumferential positions along the axial length of the balloon.

[0190] Example 50. Any of the embodiments herein, particularly the balloon of any one of Examples 47-49, wherein the balloon and the one or more reinforcing elements comprise the same material.

[0191] Example 51. Any of the embodiments herein, particularly the balloon of any of Examples 47-50, wherein the balloon and one or more reinforcing elements comprise different materials.

[0192] Example 52. Any of the balloons herein, particularly any of Examples 47-51, wherein one or more reinforcing elements are configured to rupture the balloon axially along the balloon in response to the balloon being inflated with an inflation fluid and reaching a threshold inflation pressure.

[0193] Example 53. A balloon catheter comprising a shaft extending from a handle of the balloon catheter and an inflatable balloon attached to the shaft, the balloon comprising one or more reinforcing elements disposed on an inner surface of the balloon, each reinforcing element extending axially along the balloon and providing radially increasing thickness to the balloon at selected circumferential locations along the axial length of the balloon.

[0194] Example 54. The balloon catheter of any embodiment herein, especially example 53, wherein the one or more reinforcing elements and the remainder of the balloon comprise the same material.

[0195] Example 55. The balloon catheter of any embodiment herein, especially example 53, wherein one or more reinforcing elements and the remainder of the balloon comprise different materials.

[0196] Example 56. A balloon catheter of any of the embodiments herein, particularly any one of embodiments 53-55, wherein one or more reinforcing elements are configured to rupture the balloon axially along the balloon when the balloon is inflated with an inflation fluid and reaches a threshold inflation pressure.

[0197] Example 57. The balloon catheter of any of the embodiments herein, particularly any one of Examples 53-56, wherein the one or more reinforcing elements include a plurality of reinforcing elements circumferentially spaced apart from one another.

[0198] Example 58. The balloon catheter of any embodiment herein, particularly any one of Examples 53-57, wherein the balloon catheter is a delivery device for a radially expandable medical device.

[0199] Example 59. An inflatable balloon for a medical catheter comprising a first material having a first compliance and a second material having a second compliance, the inflatable balloon comprising the first and second materials arranged such that the first compliance is greater than the second compliance and a cross-section of the balloon perpendicular to a longitudinal axis of the balloon forms a weakened section that ruptures axially under pressure from an inflation fluid introduced into the balloon.

[0200] Example 60 The balloon of any embodiment herein, especially example 59, wherein the weakened section comprises more of the first material than the second material.

[0201] Example 61. Any of the embodiments herein, particularly the balloon of Example 59, wherein the weakened section comprises only the first material, and the first material extends across the thickness of the balloon within the weakened section.

[0202] Example 62. Any of the embodiments herein, particularly any one of Examples 59-61, wherein the first material and the second material are disposed in multiple layers within the balloon extending axially along the balloon.

[0203] Example 63 The balloon of any of the embodiments herein, particularly example 62, wherein each layer of the plurality of layers is concentric with one another.

[0204] Example 64. Any of the embodiments herein, particularly the balloon of Example 62 or Example 63, wherein the balloon comprises two layers of a first material and a layer of a second material, the layer of the second material being disposed between the two layers of the first material, and the weakened section is formed by a gap in the layer of the second material that is filled with the first material.

[0205] Example 65. Any of the embodiments herein, particularly the balloon of Example 62 or Example 63, wherein the balloon comprises one or more layers of a first material and one or more layers of a second material, and the weakened section is formed by a discontinuity in the one or more layers of the second material.

[0206] Example 66. Any of the embodiments herein, particularly the balloon of any of Examples 59-65, wherein the medical catheter is a delivery device for a radially expandable medical device.

[0207] Example 67. Any of the embodiments herein, particularly the balloon or catheter of any one of Examples 1-66, wherein the balloon or catheter is sterilized.

[0208] Unless otherwise stated, any feature described herein with respect to any embodiment may be combined with any other feature described with respect to any one or more of the other embodiments. For example, any one or more features with respect to one balloon may be combined with any one or more features with respect to another balloon. As another example, any one or more features of one balloon catheter may be combined with any one or more features of another balloon catheter.

[0209] In view of the many possible ways in which the principles of this disclosure can be applied, it should be recognized that the illustrated arrangements illustrate examples of the disclosed technology, and should not be construed as limiting the scope of the disclosure or the claims. Rather, the scope of the claimed subject matter is defined by the following claims, and equivalents thereof.

Claims

1. 1. An inflatable balloon for a medical catheter, comprising: a first segment having a first compliance; and a second segment having a second compliance, the first compliance being greater than the second compliance, the first segment and the second segment extending axially along a length of the balloon, and the first segment configured to rupture axially before the second segment under pressure from inflation fluid introduced into the balloon.

2. 10. The balloon of claim 1, wherein the first segment and the second segment are circumferential segments of the balloon that each extend circumferentially around a different portion of the circumference of the balloon.

3. 3. The balloon of claim 1, wherein the first segment comprises a first material having the first compliance and a first durometer, and the second segment comprises the first material and a second material having a second durometer greater than the first durometer.

4. 4. The balloon of claim 3, wherein the first segment comprises one or more circumferentially extending layers of the first material extending across the thickness of the balloon, and the second segment comprises one or more circumferentially extending layers of the first material and one or more circumferentially extending layers of the second material.

5. 5. The balloon of claim 4, wherein the second segment comprises a circumferentially extending layer of the second material disposed between multiple circumferentially extending layers of the first material.

6. 4. The balloon of claim 3, wherein the first segment comprises more circumferentially extending layers of the first material than the second material, and the second segment comprises more circumferentially extending layers of the second material than the first segment.

7. 7. The balloon of claim 1, wherein the balloon comprises a plurality of first segments having the first compliance and a plurality of second segments having the second compliance, each of the first segments being disposed between two second segments that are adjacent to each other in the circumferential direction of the balloon.

8. 3. The balloon of claim 1, wherein the first segment comprises a first material having a first durometer embedded within a second material having a second durometer greater than the first durometer, and the second segment comprises the second material.

9. 3. The balloon of claim 1, wherein the balloon comprises a first circumferentially extending portion comprising a first material having a first durometer and a second circumferentially extending portion comprising a second material having a second durometer, the second durometer being greater than the first durometer, and the first segment being formed by a tear in the second circumferentially extending portion such that a discontinuity is formed circumferentially.

10. The balloon of any one of claims 1 to 9, wherein the medical catheter is a delivery device for a radially expandable medical device.

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