Patent Application
20240277975
The invention relates to a medical device for use within the human body, such as, for example, a balloon catheter, an introducer sheath or an implant, which includes a hollow balloon component or module which can be actuated between an inflated state and un-inflated or contracted state by means of an inflation lumen, and which provides a configuration that can be used for many medical applications.
Medical balloon components are included in many different types of medical devices, to treat a broad variety of medical conditions and these balloon components take on a range of shapes and forms.
Hereinafter, the term “component” and “module” are used interchangeably to refer to a discretely inflatable balloon unit.
A typical balloon catheter includes a balloon component which when inflated expands to do useful work within the human body via percutaneous access. The balloon catheter includes a balloon component which can be manipulated or actuated by means of fluid injection, between an un-inflated or contracted state in which state it has a relatively small diameter (such that it may be easily inserted into the human body through an introducer sheath within the groin for example) to and an inflated or deployed state, in which it has a larger diameter. The balloon component performs work in reaching a fully inflated or deployed state. For example the balloon component can exert a radially outward force onto the inner portion of a compressed/crimped metal stent or implant in order to dilate said 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.
Balloon components are sometimes subjected to a Pleat and Wrap process whereby longitudinal pleats or folds are induced to the balloon component and it is then wrapped around the catheter shaft, to minimise the crossing profile of the balloon in the un-inflated or contracted state.
Balloon components are also sometimes used on introducer sheaths/ports like for example the Kii balloon blunt-tip access system by Applied Medical which makes use of a balloon component to provide anchorage with the human body during laparoscopic procedures.
On many devices including a balloon component or balloon component assembly, the balloon component is mounted near to or at the distal end of the catheter shaft, However, the balloon component can also be mounted at any mid-way point along the shaft as is the case with the Kii Access System by Applied Medical. The catheter shaft usually runs some length (usually between 10 cm and 120 cm) and on or near the proximal end of the catheter shaft is an inflation port. This inflation port is in fluid communication with the balloon component. The catheter shaft often includes a guidewire lumen and/or a working channel as is appreciated by those familiar with devices within the minimally-invasive medical devices industry.
The balloon component is inserted into the human body in an un-inflated state. With the smaller diameter, a smaller incisions or access route can be made with obvious medical advantages. The balloon component is connected to a means of inflation (such as a syringe or an auto-inflator) via an inflation lumen often running the entire length of the catheter. When the balloon component has been advanced into position, the means of inflation is actuated and the pressure within the inflation port, the inflation lumen and the balloon component increases. This pressure increase is used to do work. The work, with respect to a “compliant balloon” component, is to occlude a vessel or orifice (e.g. Foley catheters), and, with respect to a “non-compliant”, is to deploy a stent or to dilate a stenosed artery. An example for this application is a PTA catheter.
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 matter of minutes. Other balloon catheters, like the Foley catheter or the Intra-Aortic Balloon Pump (IABP) catheter, can remain in the human body for a number of weeks or even months.
Balloon catheter designers and engineers often refer to “compliant”, “semi-compliant” and “non-compliant” balloon components. These three groups are intended to describe the way in which the balloon component changes in diameter as it is inflated to greater and greater pressures or as it is inflated with greater and greater volumes of inflation fluid (for example saline or air).
Compliant balloon components increase significantly in diameter 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 20 A to 90 A range, such as silicones, latex, thermoplastic polyurethanes (TPUs) or thermoplastic elastomers (TPEs). These elastic materials can elongate or strain significantly as more inflation fluid is added within the balloon component. Balloon components made from these relatively soft materials typically inflate to take on a largely rounded, spherical or long-spherical shape when inflated to pressures greater than around 3 psi to 20 psi. Compliant balloons typically inflate at fairly low pressures in the 3 psi to 20 psi range. Indeed, some of the materials used for these types of balloon components have ultimate elongation values of around 500% (like TPUs) to around 1500% (like TPEs and Latex). Hence a compliant balloon can grow in diameter from say 3 mm in the un-inflated state to say 20 mm in the inflated state without rupture and at a relatively low inflation pressure. This feature can be useful for applications requiring occlusion or mechanical anchorage from the balloon component. It can also be useful for applications that require the balloon component to make contact with the target anatomy or device while exerting a relatively low force on that target anatomy or device to be deployed like for example a urinary balloon catheter like the Foley catheter.
Non-compliant balloon components on the other hand do not increase significantly in diameter as they are inflated to greater and greater pressures. The strong and relatively stiff materials from which these balloon components are made do not elongate or strain significantly as more inflation fluid is added within the balloon component. Consequently, the pressure within the balloon component increases significantly as more fluid is added, while the diameter of the balloon does not increase significantly. This can be useful for applications such as dilation of the target anatomy or device where a relatively high force (and high pressure) is required and a specific target diameter must be achieved, like for example in the deployment of a balloon expandable TAVI stented heart valve. Non-compliant balloon components are often made from relatively hard and in-elastic and strong (high ultimate tensile strength) polymer materials with shore durometer hardness in the 70 D to 90 D range such as, for example, Polyethylene Terephthalate (PET) and Nylon 12 (PA12). Balloon components made from these relatively hard materials typically hold their shape and diameter when inflated to relatively high pressures in the 4 atm to 40 atm range.
Semi-compliant balloon components are those which fall into a group that is in between the compliant and non-compliant groups. Semi-compliant balloon components grow more in diameter that non-compliant balloon components when inflated to higher pressures. Semi-compliant balloons typically hold pressures that are in the range of 1 atm to 20 atm. They can sometimes be configured to provide growth at relatively high pressures can thus be used to provide a “one size fits all” type device, where the clinician can choose (usually within a fairly narrow range) the diameter to which they want to inflate the balloon, usually using a diameter vs pressure chart or table provided by the device manufacturer within the instructions for use.
A standard shaped balloon component (like those used in PTA or PTCA procedures for example) can be described as having geometric features including a first or distal neck (a largely tubular or hollow cylindrical portion also known as a “leg” or “tail”) which transitions into a first or proximal conical portion (a conical or hemi-spherical region with a smaller diameter at the neck-to-cone transition and a larger diameter at the cone-to-mid-portion transition) which tapers wider to transition into a mid-portion or “working-length” of the balloon (which typically has an outer surface which is largely cylindrical in shape, and is region of the balloon component, when inflated, with the largest diameter). Distally, the mid-portion transitions to a second or distal conical portion which tapers narrower (or tapers down) to a second or distal neck which is largely tubular like the first neck.
The first and second necks are the portions of the balloon component that typically bond to the catheter shaft or shafts.
A conical balloon component has a shape similar to the standard balloon shape described above, but with no mid-portion or “working length”.
A spherical balloon component can be described as having two hemi-spherical shaped cone sections connected to one another. So, for conical and spherical balloons, the conical portion can be described as the working length of the balloon since it is the only portion of the balloon that is not bonded or fixed to the catheter shaft.
A long spherical balloon component is like a spherical balloon component, but with a cylindrical working length or mid-portion positioned between the hemi-spherical cones. In other words a long spherical balloon component is like a standard shape balloon component but with rounded cones or hemi-spherical cones.
For example, a compliant balloon component can change shape significantly between the un-inflated state and the inflated state. For example, a compliant balloon can have a standard shape when partially inflated (to some low pressure like 0.1 psi to 0.5 psi) which then grows and changes into a spherical shape when fully inflated.
Dilation balloon components are often used to expand or open up targets such as blocked or stenosed vessels or crimped-down metal stented implants for example. In some instances the force needed to dilate the target is substantial and a high-pressure tolerant non-compliant balloon component is required.
Dilation balloons are often made from relatively hard and in-elastic and strong (high ultimate tensile strength) polymer materials like those described as being “non-compliant” or “semi compliant” above. Balloons made from these relatively hard materials typically hold their shape when inflated to relatively high pressures in the 6 atm to 30 atm range, and because they can withstand these high pressure they are better suited to dilation applications which typically require moderate to high outward radial force from the balloon component.
Occlusion balloons are used to block or occlude vessels or orifices within the human body. Occlusion balloons often have an overall spherical or long-spherical shape. The “cones” in these types of balloons are sometimes formed to have a conical shape when pressurised at a very low pressure like 0.3 psi for instance. But due to the soft and compliant nature of the materials used for occlusion balloons, they typically lose their shape and “round out” when inflated to higher pressures (like 5 psi to 20 psi for example). A long-spherical balloon has a shape similar to standard balloon but with rounded hemi-spherical “cones” on both ends of the working length. A spherical balloon typically has no cylindrical mid-portion, but rather each cone transitions into the other directly.
Occlusion balloons are often made from relatively soft and elastic polymer or rubber materials as detailed in the compliant balloons description above. Balloons made from these relatively soft materials typically grow to take on a largely round or spherical or long-spherical shape when inflated to pressures greater than around 5 psi to 20 psi. Said differently, an occlusion balloon does not typically hold its shape definition throughout inflation, but rather expands towards a rounder version of its original shape.
There are also other more exotic balloon catheters fitted with balloon components with somewhat unusual shapes or configurations. For example, valvuloplasty balloon components (used to dilate or radially-expand heart valves) sometimes have an hourglass shape (where 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 (a heart valve in this example)
Cryoablation balloon catheters are sometimes fitted with 2 balloon components, 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 here.
Some devices include balloon components which have an inverted or everted region. The Cook Cervical Ripening Balloon is an example of this. By inverting one end (for example the distal neck) of a balloon component, a favourable shape balloon assembly or balloon module can be achieved, and functionality of the medical device can be improved.
In practice the proximal neck of a standard shaped balloon component is sometimes larger in diameter than the distal neck in order to allow bonding of the proximal balloon neck to an outer catheter shaft and bonding of the distal balloon neck to a smaller diameter inner catheter shaft. The annular space between the inner and outer shafts is often used as the inflation lumen to inflate the balloon component.
Those familiar with the art of balloon catheter design and manufacture 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 which can accommodate the proximal and distal necks having 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 exposed often by means of one or more “skives” or cuts or holes at a position that lies between the proximal and distal necks of the balloon component such that the inner portion of the balloon component is in fluid communication with the inflation lumen which is in fluid communication with the inflation port.
Potential use cases for a conical or spherically shaped balloon component, providing a hollow funnel, include those discussed in the prior art namely for occlusion of vessels and orifices within the human body and or for retrieval of devices or waste matter or emboli from within the human body.
As known in the prior art, inverting or everting one end of a standard shaped balloon component (including one neck and one cone and perhaps a portion of the working length) a hollow balloon component with a shape similar to a funnel can be realised. In practice, this prior art is at best, limited and at worst, fundamentally flawed.
In practice (as is known to those who have prototyped compliant inverted or everted balloons), a compliant or thin-walled occlusion balloon such as that described above and will collapse inwardly about a distal end.
The prior art includes a funnel shaped balloon with at least one inverted/everted neck region as described in CA2492020A1 (Gore). This document describes a method and apparatus for removing emboli during an angioplasty, stenting or surgical procedure. The apparatus comprises a catheter having a funnel-shaped occlusion balloon of uniform thickness disposed on a distal end of the catheter. The occlusion balloon is fused to the distal end so that it provides a substantially seamless flow transition into a working lumen of the catheter. Additionally, a distal edge of the occlusion balloon is configured to be in close proximity with an inner wall of a vessel to facilitate blood flow into the catheter and efficiently remove emboli.
The problem with the apparatus of Gore is that, when inflated the balloon will have a rounded out distal taper. The balloon is unlikely to have a conical shape when inflated because it is a compliant (or thin walled) balloon. This inevitable “rounding out” represents a departure from the intended design, which is a conical distal taper to allow a funnel shape into which devices or emboli may more easily be retracted.
There are some less common balloon catheters which make use of a plurality of balloon components assembled together in parallel such that the device allows perfusion through a vessel while the balloons are inflated there-in. Examples of these include the Bard True Flow balloon catheter which is used to pre-dilate the aortic valve prior to implantation of a TAVI valve; the Gore Tri-Lobe balloon catheter which is used to “re-model” or “post-dilate” a self-expanding stent graft within the thoracic abdominal aorta; and, more recently, the Disa Medinotec Trachealator Airway Dilation Balloon which is used to dilate the trachea. All of these devices are designed such that when inflated the balloon module or balloon assembly expands radially outward to dilate the target anatomy or target device by applying an outward radial force from within (much like a standard dilation type balloon) but whilst still allowing fluid or blood to flow through an at least partially hollow section of the inflated balloon module or balloon assembly, thus permitting perfusion during use.
Having a device which comprises multiple balloon components assembled in parallel has two key drawbacks. Since the structure to be dilated by the balloon component, either an associated device to be deployed or a part of a patient's anatomy, is often substantially cylindrical in shape, a device comprising multiple parallel balloons will make contact with that cylinder along a few discrete lines or contact-regions, which can be undesirable. For example if three balloons are positioned in parallel (as is the case with the Gore Tri-Lobe balloon catheter) the target implant may be forced into a rounded-triangle shape (when viewed in cross section) rather than a more circular shape as is desired. Moreover, the individual balloon components which make up the multi-balloon module are typically fairly high value parts. On a standard PTA balloon catheter device for example, the balloon component can cost more than the other parts combined (including catheter shafts, inflation lures/ports). So a design that relies on using multiple components will typically have a significantly higher cost of parts which can be commercially undesirable.
Other prior art shows helical balloons which are wound into a round-tubular shape to form a hollow perfusion balloon module. These hollow helical perfusion balloons are shown to have applications including balloon dilation applications like valvuloplasty, stent deployment and balloon expandable TAVI valve deployment, tasks which are possible while maintaining perfusion thanks to the hollow central portion within the windings of the helix. One drawback of some of these helical balloons is that they typically enquire a separate frame or connector to create structural linkages between each winding of each helical coil to prevent the coil from crumpling or collapsing when exposed to a significant resistive force (such as an un-deployed metal stent for example). These additional components add material and bulk to the balloon module assembly. Moreover, any additional structural component such as a frame may itself require a certain dilation force from the helical balloon in order to expand said frame, which represents an inefficiency or a loss of outward radial force available to do useful work.
By placing one standard shape balloon component inside another and by including an inner support member positioned radially inward of both balloons a hollow balloon component that allows for perfusion while the balloons are inflated is realised. Such an invention is described in US20200179116.
This invention provides a medical device, such as, for example, a balloon catheter, an introducer sheath or an implant, which includes a hollow balloon component and which can be actuated between an inflated state and an un-inflated or contracted state by means of an inflation lumen contained within a catheter to which the balloon module is affixed.
More specifically, the invention provides a novel configuration of balloon component which has a body which, in one embodiment, has at least one conical section and, in another embodiment, has a conical section and a cylindrical working section, and a cavity spaced radially inwardly of the conical section or conical section and cylindrical section.
In the inflated state, the body of the balloon module may take on an overall shape that is largely similar to either a standard shape balloon component (as described in the background section), having a first neck region which transitions into a first cone region, which transitions into a first working region, which transitions into a second cone region, which transitions into a second neck region; or a funnel shaped balloon component (as described in the prior art) having a first neck region which transitions into a first cone region, which optionally transitions into a working region.
The balloon module is configured to be mounted on or affixed to or bonded to a catheter.
The catheter may include an inflation lumen and/or a working passage or working channel.
The body of the balloon component may be comprised of an outer layer or wall and an inner layer or wall, between which an inflatable enclosure is defined and which enclosure is in fluid communication with the inflation lumen of the catheter to which the balloon module is affixed.
The inflatable enclosure may be inflated by ingress of an inflation medium passed along the inflation lumen to move from the un-inflated state to the inflated state.
Unlike the prior art, at least one portion of the inner wall may be bonded directly, by any suitable method such as, for example, a thermal-bond or thermal-weld, to at least one portion of the outer wall to provide at least one bond zone.
It is an objective of the invention that, upon inflation of the inflatable enclosure between the inner wall and the outer wall, the at least one bond zone prevents or limits the radially inward expansion of the inner wall to provide a cavity positioned radially inward of the inner wall that beneficially remains open in the inflated state and is not impinged upon by ingress of an expanding or collapsing inner wall.
From a first perspective, the invention provides a medical device which includes a balloon module which has:
The inner cone wall may be connected to the outer cone wall along the closed perimeter such that the cavity is completely defined within the cone region and is positioned radially inward from the inner cone wall.
Alternatively, the balloon module may include a working section which comprises an outer working wall, as an extension of the outer cone wall, and an inner working wall, as an extension of the inner cone wall.
The inflation enclosure in this alternative may be between the outer cone wall, the inner cone wall, the outer working wall and the inner working wall.
The working section region may take on an outer shape that is largely cylindrical, spherical or barrel-shaped. The catheter may include a working passage which may terminate near the transition of the inner neck wall to the inner cone wall. Alternatively, the working passage may extend distally beyond the neck region. Alternatively, the working passage may extend beyond the working region.
The outer working wall may be connected to the inner working wall continuously about the closed perimeter.
The working passage may terminate near the transition of the inner neck wall to the inner cone wall.
Alternatively, the balloon module may include a working section which comprises an outer working wall, as an extension of the outer cone wall, and an inner working wall, as an extension of the inner cone wall.
Further alternatively, the balloon module may include a second cone section, extending from the working section, and terminating at a second neck section. With the outer working wall connected to the inner working wall continuously about the closed perimeter, second cone section and the second neck section are not inflatable and may comprise of a single wall.
Preferably, the working passage terminates distally of the second neck section.
The first cone section may include at least aperture which is configured to allow for fluid flow or perfusion there-through or for other devices such as, for example, guide-wires, guide catheters or delivery-catheters to pass there-through when the balloon module is inflated.
The at least one aperture may be sealed about its respective perimeter with the bonding of the outer cone wall to the inner cone wall.
The balloon module may include a flexible mesh or filter or fabric which covers or extends across the at least one aperture, adapted to allow fluid, such as blood, to flow there-through whilst preventing larger particles, such as for example calcium debris from a TAVI procedure, from passing through this flexible filter.
Alternatively or additionally, the working section may include at least one aperture as described above.
Additionally, the second cone region may include at least one window cut-outs which is adapted to allow for fluid flow or perfusion there-through or for other devices such as for example guide-wires, guide catheters or delivery-catheters to pass there-through when the device is deployed and inflated.
The at least one window cut-out may be spanned by a flexible mesh or filter or fabric configured to allow fluid, such as for example blood, to flow there-through whilst preventing larger particles, such as for example calcium debris from a TAVI procedure, from passing through this flexible filter.
In one alternative, the un-inflatable second cone section may be made completely of a flexible mesh or filter adapted as described above.
The balloon module may be mounted to the catheter with the first cone region positioned distal of the first neck region.
Alternatively, the balloon module may be mounted to the catheter with the first cone region positioned proximal of the first neck region i.e. a balloon module mounted in reverse.
From a second perspective, the invention provides a medical device for use within the human body, which includes:
The at least one bond zone may cause the inner wall to move radially outwardly with the outer wall on inflation to expand the cavity.
The balloon component may extend in a catheter deployment or insertion direction (hereinafter, a distal direction). In this alternative, the balloon component engages the catheter tube with the first end positioned proximally relatively to the second end (hereinafter referred to as “a forward extending balloon”).
The balloon component may extend in a catheter retraction direction (hereinafter, a proximal direction). In this alternative, the balloon component engages the catheter tube with the first end positioned distally relatively to the second end (hereinafter referred to as “a backward extending balloon”).
The closed perimeter may be an edge or region of curvature or inflection defining a boundary or transition between the outer wall and the inner wall (hereinafter referred to as the “edge”). The edge may describe in a generally circumferential path. Alternatively. The edge may be jagged, wavi-linear, sinusoidal or crown-shaped or it may have a mitred or wedge-like shape (similar in shape to the sharp tip of a hypodermic needle for example)
The outlet may be located at any point along the catheter tube. Preferably, the outlet is disposed at or towards the distal end.
The catheter tube may have at least one working passage or working channel.
A guide-wire may be passed along or within the at least one working passage.
The catheter tube may include a conduit, within which the at least one working passage is defined.
The first end of the balloon component may engage the catheter tube with the second end engaging the conduit.
Alternatively, the first end of the balloon component may engage the conduit with the second end engaging the catheter tube.
The conduit may have an inlet disposed at or towards the distal end.
In an application which requires improved guidance or tracking along the vessel in which the catheter is deployed, the conduit may extend beyond the edge of the balloon component as an extending section. The conduit may include an a traumatic tip and radiopaque marker bands.
The balloon module may include a plurality of tethers, each of which extend between the edge and the extending section.
The tethers may be equally circumferentially spaced relatively to one another.
The plurality of tethers may extend between the edge and the extending section in an oblique direction. The plurality of tethers may converge at a tubular neck adapted to be bonded an outer surface of the extending section.
The medical device may include a flexible conical filter which extends between from the edge and the extending section and which is seal-ably connected to the edge or working portion and the extending section. The flexible filter or fabric or mesh is configured to allow fluid, such as for example blood, to flow there-through whilst preventing larger particles, such as for example calcium debris from a TAVI procedure, from passing through this flexible filter.
The balloon component may be configured with a conical portion between the first and second ends and the edge.
The at least one bond zone may be a circumferentially continuous band.
The at least one circumferentially continuous band may be adjacent the edge.
The at least one bond zones may be formed by direct sealing engagement of the inner wall to the outer wall by employing any suitable method.
Alternatively, the balloon component may have a plurality of bond zones.
Each bond zone may be elongate or circular. The elongate bond zones may be longitudinally, circumferentially, helical or spirally configured. The elongate bond zones may be straight or take on a V-, W- or chevron shape. A pair of elongate bond zones may intersect or join to provide an X-shaped bond zone, or a zig-zag bond zone or an S shape bond zone or a sinusoidal bond zone.
It is anticipated within the scope of the invention that the bond zones may take on a shape which includes a combination of any one or more of the abovementioned shapes.
The balloon component may include a plurality of inflatable pockets defined between the bond zones.
At least one of the inflatable pockets may be a circumferentially continuous inflatable pocket adjacent the edge.
As an alternative to the balloon component being configured with a conical portion alone, the balloon component may be configured to include the conical portion and a cylindrical portion between the conical portion and the edge.
The plurality of bond zones may be on the cylindrical portion (or working region or working length), the conical portion or on both the cylindrical portion and the conical portion.
In a non-occlusive or perfusion embodiment, at least one bond zone may include an aperture which opens the hollow space or cavity to an exterior of the outer wall to allow the passage of fluid, like for example blood, or other devices, like for example a guidewire or guide-catheter, through the conical portion or the cylindrical or working portion of the balloon.
In the non-occlusive embodiment, one or more of the outer wall and the inner wall may be coated with a drug-containing layer.
Preferably, a plurality of bond zones may include an aperture. The plurality of apertures may be through bond zones on the conical portion, the cylindrical portion or the conical portion and the cylindrical portion.
One or more apertures may be seal-ably covered over with a flexible filter or fabric mesh configured to allow fluid, such as for example blood, to flow there-through whilst preventing larger particles, such as for example calcium debris from a TAVI procedure, from passing through this flexible filter.
The outer wall and the inner wall may be made of a first material and a second material respectively.
The first material may be a softer, more elastic material, than the second material to assist in the formation of a seal against a vessel in which the catheter is deployed, whilst maintaining the shape of the cavity.
Alternatively or additionally, the second material may be harder than the first material to limit inward expansion of the inner wall.
Further alternatively, the first material may have a higher friction coefficient or a lower friction coefficient than the second material.
If the first material has a higher friction coefficient, with the second material being more lubricious, it may enable the catheter to anchor within the vessel whilst easing movement of a body or device within the lumen.
The invention extends to a balloon capsule catheter which includes
A generally distal portion of the catheter, preferably the distal portion of the outer tube, may be steerable by means of pull wires and a handle mounted at or near the hub or other methods commonly used for steerable catheters
The catheter may include an outer sheath which is adapted to slide over the balloon module when the balloon is in the deflated state. This could aid in inserting the balloon into the body or through narrow vasculature en route to the target treatment site.
The invention is further described by way of an examples, with reference to the accompanying drawings in which;
The medical device 10 includes an elongate, flexible, catheter tube 12 which extends between a proximal end 14 and a distal end 16. The tube typically is made from extruded polymer tubing such as PEBAX, Polyurethane, Nylon 12 or a multiplayer or braid-reinforced extrusion and typically has a length of 100 mm to 1200 mm. On the proximal end, the catheter carries at the very least a Y connector or hub 20 (including one or more Luer fittings). The hub 20 includes at least two ports, a working or guidewire port 22 and an inflation port 24. The hub may house or comprise additional features or components such as a haemostasis-valve (as is common place in introducer sheaths) and a de-airing port which would allow other devise to be inserted into the working passage or retrieved via the working passage with minimal leakage of blood or other bodily fluids and whilst maintaining air ingress. The hub may also comprise an actuating mechanism for the advancement and retraction of a sheath configured to envelop the balloon module when deflated. The hub may also include an actuating mechanism for a steerable catheter, which may allow the distal end of the catheter tube 12 to be actuated from a straight state to a somewhat curled up or bent state, to aid in placement of the balloon module within the human body.
The catheter tube comprises an outer tube 26 and a generally concentric inner tube 28. An inflation passage 30 (see
It should be noted what while a co-axial inflation configuration is shown in the Figures, another way to inflate the balloon module is using a multi-lumen extrusion, as is common practice and well-known to those familiar with the art of balloon catheter design and manufacture. Therefore the co-axial configuration is not intended to be limiting on the invention, nor is the distal end location of the outlet.
Within the inner tube 28, a working passage is defined 34. This passage communicates the working port 22, on the proximal end 14, with a working passage opening 36. The working passage 34 can be used as a guidewire-lumen. The working passage opening 36 can be configured to receive the proximal end of a guidewire and the working passage can be configured such that said guidewire can be fed proximally until it extends beyond the proximal end 14 and beyond the proximal end of the guidewire port 22. The working passage opening 36 can be configured to allow translation of a second (smaller version) of a balloon module of the invention there through, such that the second balloon module can be slidably and rotationally actuated with respect to a first balloon module.
As illustrated in
To illustrate that the balloon module's position on the catheter tube, the orientation of the balloon module, the shape of the balloon module and the number of balloon modules are non-limiting on the invention, see
As best illustrated in
The balloon module 38 is sealable affixed to the catheter at both the first end 40 and the second end 42 to envelop the outlet 32 to the inflation passage 30. In the examples, the first end is circumferentially affixed in a band (hereinafter referred to as “the neck”) to an outer surface 46 of the outer tube 26, and the second end is circumferentially affixed in a band to the outer surface 48 of the inner tube 28. In this manner, the annular-shaped outlet is enveloped. The balloon module transitions from a conical shape to a tubular shape at both zones of affixation towards the proximal end 14 as illustrated in
Configuring the balloon module as shown in
By introducing an inflation medium or fluid, such as saline (or saline plus a contrast-additives like barium sulphate can be mixed with the saline to allow for visualisation of the balloon module under X-Ray or Fluoroscopy) water, air, nitrogen or carbon dioxide into the inflation port 24, which flows along the inflation passage 30 and exits the outlet 32 into an interior (an inflation enclosure 55) of the balloon module, the balloon module can be inflated from a deflated state to an inflated state. The deflated state is significantly less voluminous (or smaller in diameter) than the inflated state as is the case with typical medical balloons. The balloon module can thus be actuated into the deflated state in which it is substantially smaller in diameter and displaces a lesser volume than when in the inflated state. This functionality is similar to a standard balloon component and has the same benefits in that the medical device 10 can be inserted into the human body (usually via an introducer sheath or port) and maneuvered into the target location within the human body while in the deflated state. Once the balloon module is in the target location, it can be inflated to perform useful work.
A characterising feature of the medical device 10 of the invention, however, is that the outer wall 50 of the balloon module 38 is bonded to the inner wall 52 within at least one bond zone 54. By way of initial example, in the first embodiment, illustrated in
The balloon module 38 can be made from a polymer such as, for example, polyurethane, nylon-12, PEBAX, PET (Polyethylene terephthalate) or THV (Polymer comprising tetrafluoroethylene, hexafluoropropylene & vinylidene fluoride for example). The polymer can also include fibre reinforcement for improved resistance to picture or burst at higher inflation pressures. The balloon module can be made using compliant or semi-complaint medical balloon materials such as Polyurethane, Pebax or a Thermoplastic Elastomer (TPE); or a non-compliant medical balloon materials such as PET (Polyethylene terephthalate) or Nylon 12. The balloon module also can be made using one material for the outer wall 50 and another material for the inner wall 52.
The balloon module 38 can be manufactured using balloon components or elements made using a blow-forming process or using a dip-casting or dip-moulding process or using an injection moulding process. The bonding of the outer wall 50 to the inner wall 52 can be achieved using heat-bonding, thermal bonding, ultrasonic-welding, an adhesive, rivets, staples, clips, hoops, woven stitches or thread or any combination of the aforementioned.
On inflation, moving from the deflated state to the inflated state, the balloon will take an inflated-shape producing a measurable outward radial force, on walls of whatever body cavity or vessel the balloon catheter is deployed within, whilst maintaining the hollow region or cavity within the inner wall 52.
By affixing, joining or bonding the outer wall 50 to the inner wall 52, the inner wall is significantly prevented from elongating, crumpling, buckling or yielding inwards (preventing occlusion of the lumen, hollow region or cavity 53). Being connected in this manner, the outer wall 50 produces an outward radial force, on inflation of the balloon module, and pulls the inner wall 52 radially outwardly with it. When the balloon is inflated, the net outward radial force is roughly equal to the inflation pressure multiplied by the area of the outer wall (“outward facing area”) minus the area of the inner wall (“inward facing area”). Since the balloon component will usually be configured to provide an outward area larger than the inward area, the net force produced by this invention when inflated with positive pressure, is an outward radial force This outward radial force maybe useful for creating a seal against the inner diameter of a vessel, and/or opening up or dilating a vessel or a stented-implant such as, for example, a stent or a balloon expandable TAVI valve or a stent-graft for treating aneurysms through a percutaneous minimally invasive procedure.
The medical device 10 of the invention can be used in many medical treatment applications such as, for example; as a retrieval device to filter-out or capture or retrieve or remove calcium deposits or fragments from the human body similar to a cerebral protection system, to retrieve other medical devices such as, for example, balloon catheters or as a dilation perfusion balloon to provide an outward radial force onto a vessel (like employing a valvuloplasty procedure) or onto an implant (like employing a balloon expandable TAVI procedure) within the human body whilst maintaining perfusion when in the inflated state, or as a drug delivery device with the outer wall of the balloon module 38 coated in a drug and, on inflation of the balloon module, this wall makes contact with a target anatomy like a blood vessel for example to deliver the drug to the target anatomy, whilst maintaining perfusion while inflated.
The working passage 34 can be used to introduce a flushing fluid or pressurising fluid or a contrasting fluid or as a working channel or conduit through which other devices can pass through like, for example, a guidewire or an Endovascular Snare System (designed to retrieve and manipulate foreign objects within the body cavity) or another balloon catheter to name a few.
Reverting to the first embodiment 10A, illustrated in
Providing a balloon module with a circumferential band 54.1 has a benefit in that no portion of a balloon component used to make the balloon module needs to be inverted or everted to provide the outer and the inner walls. Both walls can be blow-formed or made individually as a balloon component, and then cut circumferentially on or near the working region and assembled together in the orientation illustrated in
It is beneficial to manufacture the balloon module 38 in this way because it is not easy, and sometime not possible, to invert or evert the balloon when the balloon is made of harder materials like Pebax, Nylon 12 and PET. Furthermore this manufacturing method allows for a different material to be used for the outer vs inner walls, having advantages described below.
Having the balloon 38 made in this manner allows for the introduction of harder and stronger materials which is beneficial for higher pressure balloon applications for example when a significant outward radial force is needed to open a constricted vessel, deploy a stent, post-dilate a stent or deploy or post dilate a stented-heart-valve. Furthermore, this manufacturing method makes it possible to form each wall (50, 52) from a distinct material, for example the outer membrane could be made from a Pebax 72D material, while the inner membrane could be made from a softer more elastic Pebax 63D material. The benefit here is that each surface can then be optimised to promote improved functionality. For example, the inner wall 51 can be made from a lubricious material like THV, such that it is easier to pull foreign objects (like prior deployed medical devices) into it, while the outer wall 50 can be made from a higher friction coefficient material like Polyurethane, to promote anchorage within the vessel.
Alternatively, the inner wall 52 can be made from a stronger and harder material (like Nylon 12 or Pebax 72D), less likely to collapse inwards under the inflation pressure, while the outer wall 50 can be made from a softer more elastic material (like Polyurethane with shore hardness 70A-80A or Pebax 35D) which is better suited to expand outwards under pressure like a standard compliant balloon component. This would allow for the outer wall to elongate and form a more comprehensive seal with the target vessel or device or implant within which it is inflated, without compromising the inner hollow shape of the lumen 53.
In a second embodiment 10B, illustrated in
This pattern is not limiting on the invention and equally, the bond zones can be oriented to be circumferential, helical, spiral, with each zone either straight, taking on a V-, W- X- or chevron shape, an S-shape, a zig-zag shape or a circular shape or any combination of the foregoing.
In a third embodiment 10C, illustrated in
In addition to the inflatable pocket 56.1, between the longitudinally aligned bond zones (54), there is a plurality of inflatable pockets (respectively designated 56.2, 56.3, 56.N) which allow fluid communication between the outlet 312 and the inflatable pocket 56.1.
A fourth embodiment 10D is illustrated in
In this embodiment, the balloon is configured with the circumferentially continuous inflatable pocket 56.1 and a plurality of longitudinally aligned bond zones (54.2 to 54.N) formed on the cylindrical portion 60.
Within the bond zones on the conical portion, cut-outs or apertures 62 are formed. These window cut-outs serve two key functions: they allow the balloon to be inflated, without occluding the vessel within which it has been inflated (this could be used to dilate a sensed vessel or valve (valvuloplasty) or to deploy a stent, stented-heart-valve, or stent-graft for treatment of aneurysm without occluding blood flow); and they remove material from the balloon module reducing the total amount of material needed, thereby improving the balloon's ability to fit into a small space when deflated which is advantageous for insertion through a guide-catheter, sheath, port or working channel of another device like an endoscope for example.
Moreover, this particular non-occlusive embodiments (see
Instead of the circumferential inflatable pocket 56.1, this feature can be replaced with the circumferential band 54.1 depending upon application.]
Embodiment 10H is illustrated in
Embodiment 101 is illustrated in
Another embodiment 10J is illustrated in
In a further embodiment 10L, illustrated in
This embodiment could be configured to allow both balloon modules to inflate simultaneously and from the same pressure source (as drawn) or individually in a two-step inflation protocol. This two-step inflation protocol could be achieved by running the inner tube 28 all the way to the proximal end or hub 20 of the catheter, and thereby creating a second inflation lumen or second annular inflation space. This could allow the annular lumen between the outer catheter shaft and the central catheter shaft to be pressurised independently, thereby inflating the proximal balloon module but not the distal balloon module. It can be beneficial for the balloon module to inflate from a proximal side as well as from a distal side, particularly when deploying an implant. This functionality can aid in uniform deployment of the implant, with both the proximal and distal ends of the implant expanding together, as the balloon inflated from each end simultaneously.
As with the non-inflatable tethers 65 of embodiment 10K, the distal balloon module 10.2 in this embodiment functions as an inflatable tether to the proximal balloon module 10.1 in that it connects the closed perimeter 44 to the inner tube 28 with the advantages discussed above in paragraph 145.
A guidewire 66 can pass through the inner catheter shaft, and through the tip and out of the distal end of the device. Radiopaque marker bands 67 can be added to the central catheter shaft to allow positioning of the device within the target site under x-ray imaging guidance.
In all the preceding embodiments, all the balloons modules 38 have been illustrated to include a forward extending balloons in that the direction of extension of the balloon 38, from the ends (40, 42) to the edge or rim 44, is a catheter deployment or forward direction. However, as illustrated in
Potential applications for the medical device of the invention include use in procedures such as cerebral protection, transcatheter aortic valve replacement, balloon valvuloplasty and tracheal balloon dilation among other.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2021/04170 | Jun 2021 | ZA | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/IB2022/055595 | 6/16/2022 | WO |
