Non-occlusive balloon catheter

Abstract

The balloon catheter (10) includes a catheter tube (12), an inflation passage (22) defined within the catheter tube and having an outlet (32), and a flexible envelope (28) engaging the catheter tube at at least proximal and distal end sections to surround the outlet and provide at least one balloon inflatable from a deflated state to an inflated state. In the inflated state, the balloon component is adapted to provide one or more lobes (34) and one or more channels (36), where a single channel is defined between adjacent sections of a single lobe or multiple channels are defined between adjacent pairs of lobes. The channels provide the balloon with a unique shape, one use of which is to provide an unobstructed passageway through which bodily fluids can pass when the balloon catheter is deployed within a blood vessel.

Description

[Technical Field]

[0001] The present invention relates to balloon catheters, and more particularly to balloon catheters having balloon modules that include lobes and channels and that can be compliant, semi-compliant, or non-compliant.

[0002] Background technology Medical balloon components are included in many different types of medical devices to treat a wide variety of medical conditions, and these balloon components come in a variety of shapes and forms.

[0003] Hereinafter, the terms "component" and "module" are used interchangeably to refer to an individually inflatable balloon unit. A balloon module refers to a balloon component that is constructed from multiple subcomponents into a balloon subassembly or "balloon module," which can then be assembled onto a medical device, such as a balloon catheter or a robotically controlled surgical device.

[0004] A typical balloon catheter includes a balloon component that expands when inflated to perform a useful task within the human body via percutaneous access. The balloon catheter includes a balloon component that can be manipulated or actuated by fluid injection between an uninflated or deflated state having a relatively small diameter (e.g., so that it can be easily inserted into the human body through an introducer sheath in the groin) and an inflated or deployed state having a larger diameter. The balloon component performs a task upon reaching the fully inflated or deployed state. For example, the balloon component can exert a radially outward force on the inner portion of a blood vessel or a compressed / crimped metal stent or implant to expand the implant into its deployed state. Examples of these more typical balloon catheters include PTA (percutaneous transluminal angioplasty) balloon catheters, Foley balloon catheters, and TAVI (transcatheter aortic valve implantation) balloon catheters.

[0005] The balloon component sometimes undergoes a pleating and wrapping process in which longitudinal pleats or folds are induced in the balloon component to minimize the transverse profile of the balloon in the uninflated or deflated state, and then it is wrapped around the catheter shaft.

[0006] Balloon components may also be used on introducer sheaths / ports, such as the Kii™ Balloon Blunt Tip Access System by Applied Medical, which utilizes balloon components to provide fixation with the body during laparoscopic procedures.

[0007] In many devices that include a balloon component or balloon component assembly, the balloon component is mounted near or at the distal end of the catheter shaft. However, the balloon component can also be mounted at any intermediate point along the shaft, as in the Kii™ Access System by Applied Medical. The catheter shaft typically extends for some length (typically 10 cm to 120 cm) and has an inflation port on or near the proximal end of the catheter shaft. This inflation port is in fluid communication with the balloon component. The catheter shaft often includes a guidewire lumen and / or working channel, as will be understood by those familiar with devices within the minimally invasive medical device industry.

[0008] The balloon component is inserted into the human body in an uninflated state. With a smaller diameter, a smaller incision or access path can be made, with obvious medical advantages. The balloon component is often connected to an inflation means (such as a syringe or automatic inflator) via an inflation lumen that runs the entire length of the catheter. As the balloon component is advanced into position, the inflation means is actuated, increasing pressure within the inflation port, inflation lumen, and balloon component. This increased pressure is used to perform a task. For a "compliant balloon" component, the task may be to occlude a vessel or orifice (e.g., a Foley catheter) or, for a "non-compliant" component, to deploy a stent or widen a narrowed artery. An example of this application is a PTA catheter.

[0009] Many balloon catheters remain in the body for only a short time. PTA, PTCA (percutaneous transluminal coronary angioplasty) and TAVI balloon catheters are examples that typically remain in the body for a few minutes. Other balloon catheters, such as Foley catheters or intra-aortic balloon pump (IABP) catheters, can remain in the body for weeks or even months.

[0010] Balloon catheter designers and engineers often refer to balloon components as "compliant," "semi-compliant," and "non-compliant." These three groupings are intended to describe the way in which the diameter of a balloon component changes as it is inflated to increasingly higher pressures or with increasingly larger volumes of inflation fluid (e.g., saline or air).

[0011] Compliant balloon components increase in diameter significantly as they are inflated. Compliant balloon components are generally made from relatively soft and elastic polymer or rubber materials with Shore durometer hardness in the range of 20A to 90A, such as silicone, latex, thermoplastic polyurethane (TPU), or thermoplastic elastomer (TPE). These elastic materials can significantly stretch or strain as more inflation fluid is added to the balloon component. Balloon components made from these relatively soft materials typically expand to assume a large, rounded, spherical or spheroidal shape when inflated to pressures above about 3 psi to 20 psi. Compliant balloons are typically inflated at relatively low pressures, in the range of 3 psi to 20 psi. In fact, some of the materials used for these types of balloon components have ultimate elongation values ​​of about 500% (e.g., TPU) to about 1500% (e.g., TPE and latex). Thus, a compliant balloon can increase in diameter from approximately 3 mm in an uninflated state to approximately 20 mm in an inflated state at a relatively low inflation pressure without rupturing. This feature can be useful in applications requiring occlusion or mechanical fixation from the balloon component. It can also be useful for applications requiring the balloon component to contact the target anatomy or device while exerting relatively low forces on the deployed target anatomy or device, such as urological balloon catheters such as Foley catheters.

[0012] Non-compliant balloon components, on the other hand, do not significantly increase in diameter as they are inflated to increasingly higher pressures. The strong and relatively rigid materials from which these balloon components are made do not significantly stretch or distort as more inflation fluid is added to the balloon component. Thus, while the pressure within the balloon component increases significantly as more fluid is added, the balloon diameter does not increase significantly. This can be useful for applications such as the expansion of a target anatomy or device where relatively high forces (and high pressures) are required and a specific target diameter must be achieved, such as in the deployment of a balloon-expandable TAVI stented heart valve. Non-compliant balloon components are often made from relatively hard, inelastic, and strong (high ultimate tensile strength) polymeric materials with Shore durometer hardness in the range of 70D to 90D, such as polyethylene terephthalate (PET) and nylon 12 (PA12). Balloon components made from these relatively hard materials typically retain their shape and diameter when inflated to relatively high pressures in the range of 4 atm to 40 atm.

[0013] Semi-compliant balloon components fall into a group between the compliant and non-compliant groups. Semi-compliant balloon components expand in diameter to higher pressures than non-compliant balloon components. Semi-compliant balloons typically hold pressures in the range of 1 atm to 20 atm. They can sometimes be configured to provide expansion at relatively high pressures and thus can be used to provide a "one size fits all" type of device, allowing the clinician to select the diameter (usually within a relatively narrow range) to which they want to inflate the balloon using a diameter versus pressure (or sometimes volume) chart or table, usually provided by the device manufacturer in the instructions for use.

[0014] Standard-shaped balloon components (such as those used in PTA or PTCA procedures) can be described as having geometric features including a first or distal neck (a mostly tubular or hollow cylindrical portion, also known as the "leg" or "tail") that transitions to a first or proximal cone (a conical or semispherical region with a smaller diameter at the transition from the neck to the cone and a larger diameter at the transition from the cone to the mid-section), which tapers more broadly as it transitions to the mid-section or "working length" of the balloon (typically a region of mostly cylindrical shape, with an outer surface that, when inflated, is the region of the balloon component with the largest diameter). Distally, the mid-section transitions to a second or distal cone, which tapers more narrowly toward the second or distal neck, which, like the first neck, is mostly tubular.

[0015] The first and second necks are typically portions of the balloon component that attach to one or more catheter shafts or medical devices.

[0016] The conical balloon component has a shape similar to the standard balloon shape described above, but does not have a middle section or "working length."

[0017] A spherical balloon component can be described as having two hemispherical conical sections connected to one another. Thus, for conical and spherical balloons, the conical portion can be described as the working length of the balloon, as it is the only portion of the balloon that is not bonded or secured to the catheter shaft.

[0018] A spheroidal balloon component is similar to a spherical balloon component, but with a cylindrical working length or middle section positioned between hemispherical cones. In other words, a spheroidal balloon component is similar to a standard shaped balloon component, but with rounded or hemispherical cones.

[0019] For example, a compliant balloon component can change shape significantly between an uninflated state and an inflated state. For example, a compliant balloon can have a normal shape when partially inflated (to some low pressure, such as 0.1 psi to 0.5 psi), and then grow and change to a spherical shape when fully inflated.

[0020] Dilatation balloon components are often used to dilate or open targets, such as, for example, blocked or narrowed blood vessels or crimped metal stented implants. In some cases, the force required to dilate the target is substantial, requiring a high-pressure resistant non-compliant balloon component.

[0021] Dilatation balloons are often made from relatively stiff, inelastic, and strong (high ultimate tensile strength) polymeric materials, such as those described above as "non-compliant" or "semi-compliant." Balloons made from these relatively stiff materials retain their shape when inflated to relatively high pressures, typically in the range of 6 atm to 30 atm, and because these materials can withstand these high pressures, these materials are typically better suited for dilatation applications requiring moderate to high outward radial forces from the balloon components.

[0022] Occlusion balloons are used to block or occlude blood vessels or orifices within the human body. Occlusion balloons often have an overall spherical or prolate spheroidal shape. The "cones" in these types of balloons may be formed to have a conical shape when inflated to very low pressures, such as 0.3 psi. However, due to the soft and compliant nature of the materials used in occlusion balloons, they typically lose their shape and become "rounded" when inflated to higher pressures (e.g., 5 psi to 20 psi). Prolate spheroidal balloons are shaped like standard balloons but have rounded, hemispherical "cones" at both ends of their working length. Spherical balloons typically do not have a cylindrical middle section; rather, each cone transitions directly into the other.

[0023] Occlusion balloons are often made from relatively soft and elastic polymeric or rubber materials, as detailed in the compliant balloon description above. Balloons made from these relatively soft materials typically grow to assume a mostly round, spherical, or spheroidal shape when inflated to pressures above about 5 psi to 20 psi. In other words, an occlusion balloon typically does not retain its shape definition throughout inflation, but rather expands toward a rounder version of its original shape.

[0024] There are also examples of compliant balloons (typically made from relatively soft and elastic materials) used to expand target vessels, implants, or devices with relatively low outward radial force or pressure. This may be desirable to minimize the risk of damaging the target anatomy by exerting excessive expansion force from the balloon. Because compliant balloons typically operate at low pressures, the force exerted by these balloons is typically lower. The "Reliant" balloon by Medtronic and the "Coda" balloon by Cook are examples of compliant medical balloons used to remodel aortic stent grafts. These balloons are designed to eliminate endoleaks to treat aortic aneurysms using TEVAR (thoracic end-vascular aortic repair) or EVAR (end-vascular aortic repair) procedures. Endoleaks are the failure of a stent graft to form a seal against the aorta at its proximal or distal end, which can lead to leakage between the stent graft and the aortic wall and render the implant ineffective. Remodeling or expanding these stent grafts to full circumferential contact with the aorta (enabling a pressure seal) requires a relatively low outward radial force, and therefore a compliant balloon may be used. Not that low-pressure expansion is undesirable (as in many TEVAR procedures), but rather that it may be desirable for the pressure within the balloon component to remain low throughout its use to limit or eliminate the risk of damage to the surrounding anatomy.

[0025] Other, more unusual balloon catheters also exist that have balloon components attached with somewhat unusual shapes or configurations. For example, valvuloplasty balloon components (used to dilate or radially expand heart valves) sometimes have an hourglass shape (the working portion of the balloon includes a central "waist" region with a smaller diameter) that allows the balloon to fit more snugly within the target anatomy (in this example, the heart valve).

[0026] Cryoablation balloon catheters may be fitted with two balloon components, with the inner balloon positioned radially inward from the outer balloon. In other words, the inner balloon is positioned within the outer balloon. The Arctic Front system is an example of a balloon catheter including two balloons as described herein.

[0027] Some devices include balloon components with inverted or everted regions. The Cook Cervical Ripening Balloon is an example of this. By inverting one end of the balloon component (e.g., the distal neck), a preferred shape of the balloon assembly or balloon module can be achieved, which can improve the functionality of the medical device.

[0028] In practice, the proximal neck of a standard-shaped balloon component may be larger in diameter than the distal neck, allowing the proximal balloon neck to be coupled to an outer catheter shaft and the distal balloon neck to be coupled to a smaller diameter inner catheter shaft. The annular space between the inner and outer shafts is often used as an inflation lumen for inflating the balloon component. This type of catheter shaft configuration is sometimes referred to as a "coaxial" catheter shaft.

[0029] Those familiar with the art of balloon catheter design and manufacturing will know that, in other instances, the balloon component on a balloon catheter may have proximal and distal necks with the same or similar diameters and may be mounted on a multi-lumen catheter shaft that can accommodate proximal and distal necks with similar diameters. One of the lumens in the multi-lumen shaft is used as an inflation lumen for the balloon component. The inflation lumen is often exposed by one or more "skives" or cuts or holes located between the proximal and distal necks of the balloon component, such that the interior portion of the balloon component is in fluid communication with the inflation lumen, which is in fluid communication with the inflation port.

[0030] There are several less common balloon catheters that utilize multiple balloon components assembled in parallel to allow the device to perfuse blood vessels while the balloons are inflated within the vessel. Examples include the Bard True Flow™ balloon catheter, used to pre-dilatate the aortic valve before implantation of a TAVI valve; the Gore Tri-Lob™ balloon catheter, used to “reconstruct” or “post-dilatate” a self-expanding stent-graft in the thoracic-abdominal aorta; and, more recently, the Disa Medinotec™ Tracheator Airway Dilation Balloon, used to dilate the trachea. All of these devices are designed so that, when inflated, the balloon module or balloon assembly expands radially outward, applying an outward radial force from the inside to dilate the target anatomy or device (much like a standard dilatation-type balloon), while still allowing fluid or blood to flow through at least a partially hollow section of the inflated balloon module or balloon assembly, thus enabling perfusion during use.

[0031] Perfusion balloon devices that include multiple balloon components assembled in parallel (such as the True-Flow & Tri-Lobe device) have three significant drawbacks: (i) the individual balloon components that make up a multi-balloon module are typically expensive parts. In many balloon catheter devices, a balloon component can cost more than the sum of its other parts. Therefore, designs that rely on using multiple balloon components typically have significantly higher part costs that may be commercially undesirable; (ii) the additional assembly operations required to bond each balloon component to the catheter shaft require additional time and testing, resulting in higher development and manufacturing costs; and (iii) the additional pressure bonding introduces additional risks that need to be considered during the design validation phase of product development and may increase the cost of developing a product.

[0032] By placing one standard shaped balloon component inside another and including an inner support member positioned radially inward of both balloons, a hollow balloon component is implemented that allows for perfusion while the balloons are inflated. Such an invention is described in U.S. Patent Application Publication No. 2020-0179116.

[0033] Summary of the Invention Hereinafter, "flexible envelope" refers to the flexible material, i.e., the material that constitutes the balloon module.

[0034] Hereinafter, "basic state" refers to the state of the balloon module partially inflated to a pressure of 0.1 to 1 psi, where the balloon module assumes its inherent shape with an inner diameter and an outer diameter.

[0035] Hereinafter, the term "inflated state" refers to a state in which the balloon module is fully inflated to a certain pressure threshold within which the balloon maintains its inherent shape, but above which pressure the balloon becomes distorted from its inherent shape.

[0036] Hereinafter, the term "overinflated state" refers to the state of a balloon module that has been overinflated beyond a pressure threshold, beyond which the balloon module progressively distorts from its natural shape until the inner diameter equals the outer diameter.

[0037] The present invention provides a balloon catheter or medical device, the balloon catheter or medical device comprising: a catheter tube defining a longitudinal axis; an inflation passage defined within the catheter tube and having an outlet; a flexible envelope engaging the catheter tube at least at the proximal and distal end sections and surrounding the outlet to provide at least one balloon component inflatable from a deflated state to an inflated state by the entry of inflation fluid through the outlet; Including, In an inflated state, the balloon component is adapted or confined to provide at least one lobe and at least one channel, the at least one channel being formed between adjacent sections of the at least one lobe or between an adjacent pair of lobes; At their outermost radial limits, the plurality of lobes define an outer (or working) diameter (OD), and at their innermost radial limits, the plurality of channels define an inner diameter (ID).

[0038] The balloon catheter may be a non-occlusive balloon catheter.

[0039] The at least one channel and the at least one lobe may follow corresponding helical paths.

[0040] The balloon catheter may include multiple lobes and multiple channels.

[0041] Each lobe and each channel may extend longitudinally between at least the proximal and distal end sections.

[0042] The flexible envelope can be engaged with the catheter along at least one intermediate section between the proximal and distal end sections to configure the flexible envelope into at least the first and second balloon components.

[0043] Each channel may extend directly between the proximal and distal end sections, or between the proximal and mid sections, and between the mid and distal sections.

[0044] Alternatively, each channel may follow a serpentine, sinusoidal, or spiral path between its respective sections.

[0045] The multiple lobes may be uniformly angularly spaced relative to one another about the longitudinal axis.

[0046] Each channel and each lobe may be coextensive with one another.

[0047] Alternatively, the channels may spiral in clockwise and counterclockwise directions, intersecting at points to provide multiple diamond-shaped lobes between them.

[0048] The flexible envelope can be made from a compliant or semi-compliant material (capable of withstanding moderate to high pressures, but with greater compliance and flexibility than non-compliant materials).

[0049] The material may include one or more of thermoplastic polyurethane (TPU), thermoplastic elastomer, silicone rubber, polyether block amide (PEBAX), and nylon 12 (PA12).

[0050] Preferably, the flexible envelope is made from a homogeneous material.

[0051] The balloon component may have or be adapted with a plurality of confining (or stiffer or less compliant) sections, each confining section at least partially coextensive with a respective channel, and a plurality of expandable (or more compliant) sections, each expandable section at least partially coextensive with a respective lobe.

[0052] In one alternative, the flexible envelope may be fitted with a containment section having a thicker wall thickness compared to the wall thickness of the compliant section.

[0053] In another alternative adapted for high pressure applications, such as dilating a vessel, tissue or implant, the balloon catheter can include a tubular brace engaging the exterior of the flexible envelope and including at least a proximal end hub and a distal end hub, and a plurality of longitudinally extending tension elements extending between and connecting the proximal and distal end hubs.

[0054] The tubular brace may include at least one intermediate hub between the proximal end hub and the distal end hub, and a plurality of longitudinally extending tension elements extend between the proximal end hub and the at least one intermediate hub and connect the proximal end hub to the at least one intermediate hub and the at least one intermediate hub to the distal end hub, respectively.

[0055] The elements may be uniformly angularly spaced.

[0056] Each element may extend along a respective confinement section and be adapted to confine that section in an expanded state and provide a respective channel as adjacent expandable sections expand through respective gaps (or slots) between the elements and provide a respective lobe.

[0057] The brace may be made from a tubular blank that is cut to provide the hub, elements, and gaps.

[0058] The tubular blank may be made from a metal, polymer, or composite material.

[0059] Alternatively, the brace may be made of filaments that are formed or shaped to provide the hub, elements and gaps.

[0060] The filaments may be made from a suitable metal, polymer, or composite material.

[0061] Each filament may be a single length wire, braid, or strand from which the hub and elements are integrally formed to minimize or eliminate joint points.

[0062] Each hub may be adapted to resist radial expansion and constitutes a circumferential section of the brace.

[0063] The filaments comprising the hub are formed with a plurality of diametric or radial expansion formations, each adapted to allow the brace to expand diametrically or radially, allowing assembly of the brace onto the balloon component.

[0064] The expansion formation may be corrugated, with its height aligned with the longitudinal axis and its width aligned with the circumference of the catheter tube.

[0065] The filaments making up the element may be formed with at least one longitudinally extending formation adapted to allow the brace to stretch longitudinally in response to inflation of the balloon component.

[0066] At least one longitudinally extending formation is corrugated, the height of which corresponds to the circumference of the catheter tube and the width of which is aligned with the longitudinal axis.

[0067] Preferably, each element has two longitudinally extending formations, one at each end, positioned within the conical region of the balloon component.

[0068] When the balloon module is in its basic state, the ID may be 20% to 80% of the OD.

[0069] When the balloon module is in an inflated state, the ID may be 20% to 80% of the OD.

[0070] When the balloon module is in an over-inflated state, the ID can increase relative to the OD, and in this state, each channel can become progressively shallower until the ID is 100% of the OD.

[0071] The balloon catheter or medical device may include a tubular sleeve positioned radially outward from the balloon component, which surrounds at least a portion of the working length of each balloon component and is adapted to limit the radial expansion of the multiple lobes (and OD) or to protect the flexible envelope from puncture by, for example, a stenosis, a calcified vessel, or an implant.

[0072] The tubular sleeve may be made of a suitable non-elastic material with high tensile strength, such as Kevlar.

[0073] The invention will now be further described, by way of example only, with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0074] [Figure 1] 1A-1C schematically illustrate various embodiments of a balloon catheter device comprising one or more balloon modules. [Figure 2] 2A-2D show a first embodiment of a balloon catheter device. [Figure 3] 3A-3H show a first embodiment of the device from various perspectives. [Figure 4] 4A-4F show a first embodiment of the device. [Figure 5] 5A-5D show the wire brace alone in an uninflated state engaged with the balloon component. [Figure 6] 6A-6C show a wire brace engaged with the balloon component of a device according to a second embodiment, with the component in an inflated state. [Figure 7]7A-7C show a third embodiment of the device having an outer sleeve that surrounds at least a portion of the balloon component. [Figure 8] 8A-8B show several embodiments of the device, each having a different shaped balloon component. [Figure 9] 9A-9F show another embodiment of the present invention including a wire brace with diamond-shaped openings. [Figure 10] 10A-10F illustrate a further embodiment of the present invention in which the brace includes a pair of hub surrounding jackets. [Figure 11] 11A-11F show a final embodiment of the present invention having a single spiral channel and corresponding lobes.

[0075] MODE FOR CARRYING OUT THE INVENTION 1-10 illustrate various embodiments and configurations of a non-occlusive balloon catheter device 10 according to the present invention.

[0076] Balloon catheter device 10 includes an elongated flexible catheter tube or shaft 12 extending between a proximal end 14 and a distal end 16. At the proximal end, the catheter tube has a hub 15 which, in the illustrated example, has a pair of inflation ports, designated 18.1 and 18.2, respectively, and a working channel inlet port 19.

[0077] The inflation ports are in fluid communication with inflation passages or passages 22.1 and 22.2 (see FIG. 2D). Also contained within tube 12 is a working passage 24 which terminates in an opening 26 at its distal end.

[0078] While a single inflation port may be sufficient, having two separate inflation ports has the advantage of faster inflation and deflation times and allows for fluid to be circulated through the ports, one port as an inlet and one port as an outlet, allowing for continuous replacement or circulation of fluid within the balloon, which may have application-specific advantages, such as energy delivery during therapy.

[0079] As shown in Figure 1A, the device 10 has a single balloon component 28.A at the distal end of the catheter tube 12. In Figure 1B, the device has two balloon components (designated 28.B and 28.C, respectively) positioned midway between the proximal and distal ends (14, 16). In Figure 1C, a dual balloon component embodiment 28.D is shown at the distal end. The balloon components may be configured according to any of the embodiments described below.

[0080] However, it is contemplated within the scope of the present invention that a balloon component or components of various configurations may be positioned on the catheter tube 12 at any point between the ends (14, 16).

[0081] With regard to the structure and configuration of the balloon component, Figures 2A and 2B show a first embodiment of device 10.1 in which balloon component 28.1 is comprised of a flexible envelope, preferably made from a homogeneous material, that is sealably affixed to catheter tube 12 (depicted shorter for ease of illustration) at a circumferential proximal end section (proximal neck) 27 and a circumferential distal end section (distal neck) 29, enclosing an outlet(s) 32 in the catheter tube.

[0082] For ease of description, only a single outlet 32, a single inflation passage, and a single inflation port will be referenced, despite the presence of multiple of these features in the embodiment being described.

[0083] The outlet 32 ​​is in fluid communication with the inflation port 18 along the inflation passage 22 to allow the inflow of inflation fluid through the outlet to inflate the balloon component 28.1 from a deflated state to an inflated state. In this manner, the deflated balloon component 28 facilitates their insertion into a blood vessel and maneuvering the component to a target location where it can be inflated to perform a useful task.

[0084] In the inflated state (as shown), the balloon component is adapted or confined (depending on the embodiment, but in this embodiment the balloon component is adapted as described below) to provide a plurality of lobes (respectively designated 34.1, 34.2, ... 34N) and a plurality of channels (respectively designated 36.1, 36.2, ... 36N), each defined between adjacent pairs of lobes (e.g., channel 36.1 defined between lobes 34.1 and 34.2), with the plurality of lobes defining an outer (or working) diameter (OD) and the plurality of channels defining an inner diameter (ID) at their outermost radial limits. Both the OD and ID are shown in dotted lines in FIG. 2C.

[0085] In this example, the channels and lobes are longitudinally aligned and regularly angularly spaced relative to the longitudinal axis, as shown in Figure 3C. The lobes are also substantially coextensive with the channels along the working length, with the respective ends of each expansion lobe tapering toward the proximal and distal end sections (27, 29) at respective conical sections 31.1 and 31.2.

[0086] Materials making up the flexible envelope of the balloon module may include (in blends or multi-layers) one or more of TPU (thermoplastic polyurethane) (typically 40A to 75D Shore durometer hardness), TPE (thermoplastic elastomer) (typically 15A to 80A), PEBAX (by Arkema) (polyether block amide) (typically 22D to 75D), approximately 72D nylon 12 (PA12), and PET (polyethylene terephthalate).

[0087] Examples of blends are TPU + PEBAX and PEBAX + PA12. Multilayer flexible envelopes can be made in a multilayer extrusion process, allowing for blowing balloons with inner and outer layers (which are bonded together wherever they are coextruded) without the need for an additional blow molding step. Drug coating typically occurs as a secondary process on the outer layer of the balloon.

[0088] The device 10 may also include radiopaque marker bands (not shown) positioned within and / or proximal and / or distal to the balloon component to enable positioning of the device within the target anatomy.

[0089] In Figures 3A, 3B, and 3C, the balloon component 28.1 of device 10.2 is shown in an inflated state, in isometric, side, and end views. The series of Figures 3D-3E sequentially show an inflation cycle and how the OD and ID initially both increase proportionally until the OD reaches a limit (defined as the fully inflated state as shown in Figure 3F), and then the ID increases further due to shallowing of channel 36 as the inflation pressure increases to the over-inflated state (see Figures 3G and 3H).

[0090] In Figures 4C and 4C.1, which are cross-sectional views through the wall 40 of balloon component 28.1, the flexible envelope is fitted with a plurality of stiff (or relatively less compliant) sections, designated 42.1, 42.2, ... 42.N, respectively, each containment section at least partially coextensive with a respective channel, and a plurality of expandable (or relatively more compliant) sections, designated 44.1, 44.2, ... 44.N, respectively, each expandable section at least partially coextensive with a respective lobe.

[0091] In this example, the change in relative compliance between the rigid and compliant sections is caused by the change in wall thickness of these sections. The rigid sections have thicker walls relative to the compliant sections. This is best shown in Figure 4C.1.

[0092] To vary the channel depth for a particular application, for any given inflation pressure, one or both of the following parameters of the flexible envelope may be varied: material of manufacture, wall thickness of the rigid section, and wall thickness of the compliant section.

[0093] 5A and 5B show another embodiment of the invention in which device 10.2 is adapted for higher pressure applications such as, for example, vascular, tissue, or implant expansion. The device includes a tubular brace 46 mounted over and positioned radially outward from the uninflated balloon component 28.2.

[0094] Brace 46 includes at least a proximal hub 48.1 and a distal hub 48.2, and a plurality of tension elements (designated 50.1, 50.2, ... 50.N, respectively) extending longitudinally between and connecting the proximal and distal hubs, the plurality of elements being uniformly angularly spaced apart as illustrated in Figure 5C.1.

[0095] The brace 46 in this example is made with an integrally formed hub and elements to minimize or eliminate connection points that can chafe and puncture the flexible envelope during use. The brace can be made from a single length of wire, braid, polymer strand, fibrous carbon, Kevlar, or monofilament.

[0096] Within the hub 48, the tension elements 49 bridge along the connection sections 52, providing hoop strength and resisting radial expansion around the hub when the enclosed balloon component 28 is inflated. However, they maintain the cylindrical shape of the hub while allowing radial expansion in a controlled manner. One or more elements within the hub can be formed with multiple corrugations (not shown), with the amplitude (height) of the corrugations aligned with the central axis of the catheter tube and the wavelength (width) of the corrugations aligned with the circumferential direction of the catheter tube, allowing the hub to expand diametrically. This can be functionally beneficial to enable assembly onto a compliant balloon component.

[0097] When engaged with the balloon component 28, each element 50 extends along and defines a respective confinement section 42, best shown in Figures 6A and 6C. Upon inflation of the balloon component, the element confines the underlying confined section to provide a respective channel 36. Respective lobes 34 are then formed as adjacent expandable sections 44 expand through respective gaps 53 between the elements.

[0098] Although not shown, the tubular brace may include at least one intermediate hub between the proximal hub (48.1) and the distal hub (48.2), with a plurality of longitudinally extending tension elements extending between the proximal hub and the at least one intermediate hub, connecting the proximal hub to the at least one intermediate hub and the at least one intermediate hub to the distal hub, respectively. Such adapted hubs would confine the intermediate section of the balloon component 28, as illustrated in Figures 8F and 8G.

[0099] As shown in Figures 6A, 6B, and 6C, each longitudinal tensile element 50 includes a longitudinally extending section (54.1 and 54.2) at each end that is positioned within the conical section 31 of the balloon component. Each longitudinally extending section is adapted to allow the frame or brace to stretch longitudinally in response to the inflation of the balloon component. This is best shown in Figures 6C1-6C3, which show the increasingly expanding balloon component and how each expandable section stretches to accommodate the expansion, allowing ID expansion with increasing inflation pressure. The longitudinally extending sections are formed into multiple corrugations (zigzag sections) with the amplitude of the corrugations aligned with the circumferential direction of the catheter tube, and the wavelength of the corrugations aligned with the longitudinal axis of the catheter tube.

[0100] 7A-7C show a balloon catheter device 10.3 according to a third embodiment. In this embodiment, the device includes an outer tubular sleeve 56 positioned radially outward from the balloon component 28.3, at least along the working length of the component. The balloon component of this embodiment is the same as the balloon component of the previous embodiment.

[0101] The sleeve is inelastic and configured to prevent the OD from increasing beyond the sleeve diameter. The sleeve may be made from a suitable high tensile strength material, such as Kevlar. The sleeve protects the balloon component 28.3 from rupture or bursting when it comes into contact with sharp objects, such as implants or vascular calcification.

[0102] Figures 8A-8G show various preferred shapes for the balloon component, designated 28.1 (the same shape as the previously described embodiment), 28.4, 28.5, 28.6, and 28.7, respectively. Shapes include elongated oval (28.1), elongated angular (28.4), diamond (28.5), spherical (28.6), and double spherical (28.7).

[0103] A double spherical embodiment can be formed using appropriately configured braces 46 as described above in paragraph 73. However, the number of balloon components is not limiting of the invention, and it is contemplated within the scope that there may be 1, 2, 3...n, n+1 balloons.

[0104] 9A-9C show a preferred embodiment of device 10.8 in which the tension elements 50 of braces 46 converge, intersect, or join at one or more points 60 between the hubs, allowing perfusion between multiple diamond-shaped lobes. This shapes the underlying balloon component 28.8 to have multiple channels 36 that spiral in clockwise (see directional arrows indicated by X) and counterclockwise (see directional arrows indicated by Y) directions and intersect at points. Diamond-shaped lobes (34.1, 34.2...34N) protrude between them.

[0105] This diamond-shaped embodiment 10.8 has many advantages. By connecting the tension elements together between the hubs, the working length of the balloon component is better constrained within the brace, reducing the risk of the balloon component expanding into an undesirable shape due to more expansion between one pair of tension elements, expansion to one side, or as it is sometimes referred to as "bull-flogging." A brace with a helical tension element that is not connected to other tension elements would induce undesirable torque on the catheter shaft in response to inflation of the balloon component.

[0106] 10A-10F show another preferred embodiment of a balloon catheter device 10.9. In this embodiment, brace 46.8 includes an outer jacket (designated 62.1 and 62.2, respectively) disposed over each hub 48 of brace 46.

[0107] This outer jacket 62 ensures that when the balloon components 28.9 are inflated, the respective hubs 48 frictionally engage the respective necks (27, 29), which in turn are affixed and held to the catheter shaft 12.

[0108] The jacket may be made from a thermoplastic polymer such as TPU or nylon or Pebax and may be "reflowed" or heat bonded onto the balloon component and / or catheter shaft so that it encases the hub of the brace.

[0109] A final embodiment of the balloon catheter device 10.10 is shown in Figures 11A-11C. A feature of this embodiment is that the balloon component 28.10 is formed with a single channel 36 that follows a helical path from the proximal end section 27 to the distal end section 29. This single helical channel corresponds to a single helical lobe 34.

[0110] The braces 46 of any embodiment can be made from metal wire, high-tensile strength polymers such as "ultra-high molecular weight polyethylene," or fibers such as Kevlar or carbon fiber. Each tension element can be mechanically connected to the other by wrapping one around the other, or by bonding, or by fastening or connecting components such as ferrules or sleeves. Alternatively, the tension elements along with the hubs can be laser cut from metal or polymer tubing. At least a portion of the brace can be coated with a polymer, which can allow for easier bonding of the brace to the balloon component. Braces coated with a soft polymer layer can also allow for increased burst pressure because the soft polymer layer cushions the brace on the balloon component and increases the contact surface area between the brace and the balloon component, thereby reducing stress within the balloon component and increasing burst pressure.

[0111] The outer surface of the balloon component 28 can be coated with a drug, which would be beneficial because the drug can come into contact with the balloon and be delivered to the target anatomy while still allowing perfusion of fluid (e.g., blood or urine).

[0112] A compliant version of the present invention includes the following features: The balloon component or flexible envelope includes an outer diameter and an inner diameter. In the "base state" (defined as a low inflation pressure in the range of 0.1 to 1 psi), the inner diameter is significantly smaller than the outer diameter. In the "inflated state" (defined as an inflation pressure above 2 psi and below a "threshold pressure" defined below), both the outer and inner diameters increase by a measurable amount compared to their respective measurements in the base state. In both the base and inflated states, the ratio (or relative size) between the outer and inner diameters can be described as follows: 1 / 5 outer diameter ≦ inner diameter ≦ 4 / 5 outer diameter

[0113] However, in a third state, termed the "overinflation state," defined by inflation pressures exceeding a "threshold pressure," The inner diameter is greater than 4 / 5 of the outer diameter.

[0114] In the hyperinflated state, the inner diameter is approximately equal to the outer diameter. This feature is useful in applications where the user desires to control the mass or volumetric flow rate of fluid passing through the perfusion channel. By increasing the inflation pressure, the user can controllably decrease the flow rate by effectively reducing the cross-sectional area available for perfusion. By continuing to increase the inflation pressure further, the user can completely occlude and stop all flow as the inner diameter is approximately equal to the outer diameter. By decreasing the inflation pressure, flow or perfusion can again be restored. This ability to control or stop flow can be useful in applications such as, for example, REBOA (Resuscitative Endovascular Balloon Occlusion of the Aorta).

Claims

1. 1. A balloon catheter (10) comprising: a catheter tube (12) defining a longitudinal axis; an inflation passage (22) defined within the catheter tube and having an outlet (32); and a flexible envelope (28) engaging the catheter tube at at least a proximal end section (27) and a distal end section (29) and surrounding the outlet (32), providing at least one balloon component inflatable from a deflated state to an inflated state by the entry of inflation fluid through the outlet (32), wherein in the inflated state, the balloon component is conformed or confined to provide at least one lobe (34) and at least one channel (36), the at least one channel being formed between adjacent sections of the at least one lobe or between adjacent pairs of lobes, and wherein, at their outermost radial limits, the plurality of lobes define an outer diameter (OD), and, at their innermost radial limits, the plurality of channels define an inner diameter (ID).

2. The balloon catheter of claim 1 , wherein the at least one lobe and the at least one channel extend longitudinally between the proximal end section and the distal end section.

3. 3. The balloon catheter of claim 1, wherein the flexible envelope engages the catheter along at least one intermediate section between the proximal end section and the distal end section to configure the flexible envelope into at least a first balloon component and a second balloon component.

4. 4. The balloon catheter according to claim 1, wherein the at least one channel extends directly between the proximal end section and the distal end section, or between the proximal end section and the intermediate section, and between the intermediate section and the distal end section.

5. 4. The balloon catheter of claim 1, wherein the at least one channel follows a serpentine, sinusoidal, or helical path between the proximal end section and the distal end section, or between the proximal end section and the intermediate section, and between the intermediate section and the distal end section.

6. The balloon catheter of any one of claims 1 to 5, wherein the flexible envelope is made from a compliant, semi-compliant, or non-compliant material.

7. 7. The balloon catheter of claim 6, wherein the material comprises one or more of a thermoplastic polyurethane, a thermoplastic elastomer, a silicone rubber, a polyether block amide, and a nylon 12.

8. The balloon catheter of claim 6 or 7, wherein the flexible envelope is made of a homogenous material.

9. The balloon catheter of any one of claims 1 to 8, wherein the at least one channel and the at least one lobe follow corresponding helical paths.

10. The balloon catheter of any one of claims 1 to 8, comprising multiple lobes and multiple channels.

11. The balloon catheter of claim 10 , wherein the plurality of lobes are uniformly angularly spaced relative to one another about the longitudinal axis.

12. 12. The balloon catheter of claim 10 or 11, wherein each channel and each lobe is coextensive with one another.

13. 13. The balloon catheter of claim 10, wherein the channel spirals in both clockwise and counterclockwise directions and intersects at points to provide multiple diamond-shaped lobes therebetween.

14. 14. The balloon catheter of claim 10, wherein the balloon component comprises a plurality of containment sections (42), each containment section at least partially coextensive with a respective channel, and a plurality of expandable sections (44), each compliant section at least partially coextensive with a respective lobe.

15. 15. The non-occlusive balloon catheter of claim 14, wherein the flexible envelope is adapted in the compliant section to have a thicker wall thickness when compared to the wall thickness in the containment section.

16. 15. The non-occlusive balloon catheter of claim 14, wherein the balloon catheter includes a tubular brace (46) engaging the exterior of the flexible envelope and including at least a proximal hub (48.1) and a distal hub (48.2), and a plurality of longitudinally extending tension elements (50) extending between and connecting the proximal and distal hubs.

17. 17. The non-occlusive balloon catheter of claim 16, wherein the tubular brace includes at least one intermediate hub between the proximal end hub and the distal end hub, and the plurality of longitudinally extending tension elements extend between the proximal end hub and the at least one intermediate hub, connecting the proximal end hub to the at least one intermediate hub and the at least one intermediate hub to the distal end hub, respectively.

18. 18. The non-occlusive balloon catheter of claim 16 or 17, wherein each hub constitutes a circumferential section of the brace and is adapted to resist radial expansion.

19. The non-occlusive balloon catheter of any one of claims 16 to 18, wherein the plurality of elements are uniformly angularly spaced apart.

20. 20. The non-occlusive balloon catheter of claim 16, wherein each element extends along a respective confinement section, confining said section in said expanded state to provide a respective channel, and wherein adjacent expandable sections are adapted to provide a respective lobe when expanded through respective gaps (35) between the elements.

21. 21. The non-occlusive balloon catheter of claim 20, wherein the brace is made from a tubular blank that is cut to provide a hub, elements, and gaps.

22. 22. The non-occlusive balloon catheter of claim 21, wherein the tubular blank is made from a metal, a polymer, or a composite material.

23. 21. The non-occlusive balloon catheter of claim 20, wherein the brace is made from filaments formed to provide a hub, elements, and gaps.

24. 24. The non-occlusive balloon catheter of claim 23, wherein the filament is a single length of wire, braid, or strand, and the hub and the element are integrally formed to minimize or eliminate connection points.

25. 25. The non-occlusive balloon catheter of claim 24, wherein the filaments are made of a metal, a polymer, or a composite material.

26. 26. The non-occlusive balloon catheter of claim 24 or 25, wherein the filaments of the hub are formed with a plurality of diametric expansion formations adapted to allow the braces to expand diametrically, allowing assembly onto a compliant balloon component.

27. 27. The non-occlusive balloon catheter of claim 26, wherein the expansion formations are corrugated, the height of the corrugations aligned with the longitudinal axis and the width of the corrugations aligned with the circumference of the catheter tube.

28. 28. The non-occlusive balloon catheter of claim 24, wherein the filaments making up the element are formed with at least one longitudinally extending formation adapted to allow the brace to stretch longitudinally in response to the inflation of the balloon component.

29. 30. The non-occlusive balloon catheter of claim 28, wherein the at least one longitudinally extending formation is corrugated, with a height that matches the circumference of the catheter tube and a width that is aligned with the longitudinal axis.

30. 30. The non-occlusive balloon catheter of claim 28 or 29, wherein each element has two longitudinally extending formations, one at each end, positioned within the conical region of the balloon component.

31. The non-occlusive balloon catheter according to any one of claims 1 to 30, wherein the ID of the balloon module in the base state is 20% to 80% of the OD.

32. 32. The non-occlusive balloon catheter of claim 31, wherein the ID of the balloon module in the inflated state is between 20% and 80% of the OD.

33. 33. The non-occlusive balloon catheter of claim 31 or 32, wherein upon hyperinflation, each channel becomes progressively shallower until the ID is 100% of the OD.

34. 34. The non-occlusive balloon catheter of any one of claims 1 to 33, comprising a tubular sleeve (56) positioned radially outward from the balloon components and surrounding at least a portion of the working length of each balloon component.

35. 35. The non-occlusive balloon catheter of claim 34, wherein the tubular sleeve is made from a suitable inelastic material with high tensile strength.

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