Energy transfer design for calcium disruption

Abstract

In some examples, a method of treating a native heart valve includes providing an intravascular lithotripsy having an energy source, a catheter operably coupled to the energy source, a balloon disposed over a portion of the catheter, and at least one lithotripsy emitter coupled to the catheter and having a funnel shape, inflating the balloon within the native heart valve, generating energy from the energy source, and funneling the energy onto a native leaflet or a native aortic annulus via the funnel shape of the at least one lithotripsy emitter while preventing the energy from being dispersed to other regions.

Description

Energy Transfer Design for Calcium DisruptionCross-Reference to Related Applications

[0001] This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 678,695, filed August 2, 2024, the disclosure of which is hereby incorporated by reference herein.Background of the Disclosure

[0002] In healthy individuals, the various valves of the heart allow for blood to flow in the forward or antegrade direction while the corresponding chamber of the heart contracts, and prevent blood from flowing in the reverse or retrograde direction while the corresponding chamber of the heart relaxes between contractions. However, the valves of the heart may become stenosed or narrowed over time, which in some circumstances is the result of buildup of calcium deposits within or on the heart valve leaflets over time. A stenosed heart valve may have leaflets that do not open as fully as a healthy heart valve. This may result in the heart having to work harder to pump enough blood through the heart to deliver blood throughout the body. For example, in aortic valve stenosis, the left ventricle may need to work harder to pump blood through the stenosed heart valve to deliver oxygenated blood through the body. Valve stenosis via calcification may also result in the valve leaflets not fully coapting, leading to regurgitation of blood through the heart valve in the wrong direction. The heart is a muscular organ, and if any chamber, such as the left ventricle, needs to work harder to pump blood, the tissue of the chamber may thicken and the chamber may enlarge over time. These changes in the physiology of the chamber may create even further inefficiencies in pumping of blood. Patients with stenosed heart valves can thus be susceptible to various conditions, including heart failure and other serious problems. Although treatments exist for heart valve stenosis, it may be preferably to be able to treat heart valve stenosis in a minimally invasive manner that either obviates the need for more invasive treatments, or enhances the effectiveness of future more invasive treatments.Summary of the Disclosure

[0003] In some examples, a method of treating a native heart valve includes providing an intravascular lithotripsy having an energy source, a catheter operably coupled to the energy source,ABTCSI-0001PCT a balloon disposed over a portion of the catheter, and at least one lithotripsy emitter coupled to the catheter and having a funnel shape, inflating the balloon within the native heart valve, generating energy from the energy source, and funneling the energy onto a native leaflet or a native aortic annulus via the funnel shape of the at least one lithotripsy emitter while preventing the energy from being dispersed to other regions.

[0004] In some examples, an intravascular lithotripsy catheter system for use in treating a native heart valve includes an energy source, a catheter operably coupled to the energy source, at least one lithotripsy emitter coupled to the catheter, and a reflective material disposed radially inward of the at least one lithotripsy emitter, and being configured to reflect energy from the at least one lithotripsy emitter onto a native leaflet or a native annulus of the native heart valve.Brief Description of the Drawings

[0005] Fig. l is a cutaway view of a simplified representation of a human heart.

[0006] Figs. 2A-2B show examples of a healthy aortic valve when closed and open, respectively.

[0007] Figs. 2C-2D show examples of a stenosed aortic valve when closed and open, respectively.

[0008] Fig. 3 illustrates a system for providing intravascular lithotripsy according to an aspect of the disclosure.

[0009] Figs. 4A-4B illustrate two emitter configurations according to an aspect of the disclosure.

[0010] Figs. 5A-5L illustrate several emitter geometries according to an aspect of the disclosure.

[0011] Figs. 6A-6B are schematic cross-sectional lateral views of catheters showing two configurations of emitters, according to an aspect of the disclosure.

[0012] Fig. 7 is a schematic cross-sectional view of a catheter having an inner reflector according to an aspect of the disclosure.

[0013] Fig. 8 is a cutaway view showing the use of a system for providing intravascular lithotripsy at an aortic valve according to an aspect of the disclosure.

[0014] Fig. 9 is a cutaway view showing the use of a system for providing intravascular lithotripsy at a mitral valve according to an aspect of the disclosure.Detailed Description of the Disclosure

[0015] As used herein, the term “inflow end” when used in connection with a heart valve refers to the end of the valve into which blood first enters, while the term “outflow end” refers to the end of the valve where blood exits. Thus, for an aortic valve, the inflow end is the end nearer the leftABTCSI-0001PCT ventricle while the outflow end is the end nearer the aorta. Further, the term “proximal,” when used in connection with a delivery device or system, refers to a position relatively close to the user of that device or system when it is being used as intended, while the term “distal” refers to a position relatively far from the user of the device. In other words, the leading end of a delivery device or system is positioned distal to the trailing end of the delivery device or system, when the delivery device is being used as intended. As used herein, the terms “substantially,” “generally,” “approximately,” and “about” are intended to mean that slight deviations from absolute are included within the scope of the term so modified.

[0016] Fig. 1 is a cutaway view of a simplified representation of a human heart 100. The human heart 100 includes two atria and two ventricles: a right atrium 112 and a left atrium 122, and a right ventricle 114 and a left ventricle 124. As illustrated in Fig. 1, the heart 100 further includes an aorta 110, and an aortic arch 120. Disposed between the left atrium 122 and the left ventricle 124 is the mitral valve 130. The mitral valve 130, also known as the bicuspid valve or left atrioventricular valve, is a dualdeaflet valve that opens as a result of pressure differential. As atrial pressure increases above that of the left ventricle 124, the mitral valve 130 opens and blood flows into the left ventricle. Similarly, disposed between aorta 110 and left ventricle 124 is the aortic valve 140. The aortic valve is a tricuspid (j.e. three leaflet) valve that opens as a result of increased pressure in the left ventricle 124. Generally, the annulus of the aortic valve 140 is substantially circular or cylindrical, while the annulus of the mitral valve 130 is substantially elliptical. Blood flows through heart 100 in the antegrade direction shown by arrows “B”, with the various heart valves preventing blood from flowing in the opposite retrograde direction.

[0017] As noted above, buildup of leaflet calcification can be one cause of heart valve stenosis. However, calcification may also occur in the annulus 141 of the heart valve, which may also contribute to stenosis. The remaining disclosure is generally described in the context of aortic valve stenosis for simplicity and because aortic valve stenosis occurs more frequently and typically creates more serious symptoms than the other valves of the heart. However, it should be noted that the disclosure herein, unless explicitly stated otherwise, applies to any valve of the heart.

[0018] Figs. 2A-2B illustrate top (superior) views an example of a healthy aortic valve 140 that includes three leaflets 140a, 140b, 140c. As shown in Figs. 2A-2B, each leaflet 140a, 140b, 140c includes a base that is coupled to the annulus 141 of the aortic valve 140, and a free edge that is configured to coapt with the free edges of the other leaflets when the aortic valve is closed, shownABTCSI-0001PCT in Fig. 2A, and to move away from the center of the annulus 141 to allow blood to flow through the aortic valve 140, shown in Fig. 2B. Figs. 2C-2D, on the other hand, illustrate an unhealthy aortic valve 140’ with three calcified leaflets 140a’, 140b’, 140c’, that are attached to the aortic valve annulus 141’. Fig. 2C shows the stenosed aortic valve 140’ in a closed condition. Note that, compared to the closed healthy valve 140 shown in Fig. 2A, the calcified leaflets 140a’, 140b’, 140c’ do not fully coapt, which may lead to regurgitation. Fig. 2D shows the stenosed aortic valve 140’ in an open condition. Note that, compared to the open healthy valve 140 shown in Fig. 2B, there is less open area between the calcified leaflets 140a’, 140b’, 140c’ through which blood may flow. This narrowing is the reason that the condition is termed aortic valve stenosis.

[0019] One treatment for aortic valve stenosis (or stenosis of other valves) is the implantation of a prosthetic heart valve within the diseased heart valve. Such procedures may include minimally invasive valves that can be delivered through the vasculature and expanded into the diseased heart valve (e.g., transcatheter aortic valve replacement or TAVR) as well surgical valve replacement in which access to the heart is gained surgically while the patient is on cardiopulmonary bypass and a new prosthetic heart valve is sutured into the diseased annulus.

[0020] Another treatment for aortic valve stenosis is valvuloplasty. In a valvuloplasty procedure, a catheter with a balloon tip is passed through the vasculature of the patient until the balloon, while deflated, is positioned within the diseased native heart valve. At that point, the balloon is expanded with a fluid, typically a liquid such as saline (or a saline-contrast solution). The balloon is expanded until it contacts the diseased leaflets and / or valve annulus, with high forces from the balloon expansion forcefully opening the diseased valve in an attempt to at least partially relieve the stenosis. Often, although not always, if valvuloplasty is being performed, it will be followed by transcatheter implantation of a prosthetic heart valve.

[0021] In some examples, it may be beneficial to remove or disrupt these calcium deposits from anatomical structures in order to obviate the need for more invasive treatments (e.g., valve replacement, surgical removal, etc.). Alternatively, removal or disruption of the calcium deposits may enhance the effectiveness of subsequent treatment(s).

[0022] Fig. 3 illustrates an intravascular lithotripsy (“IVL”) system 300, which may generally include a power source 312 (e.g., in the form of an electrical generator or a laser system), a handle 314 with therapy delivery control 315, a catheter 320 with a plurality of lithotripsy emitters 322 (shown in the form of conical electrodes, but alternatively they could comprise optical or laserABTCSI-0001PCT emitters), and a fluid filled balloon 324. Optional marker bands 325, which may be for example radiopaque markers, may be provided. The catheter 320 may include a central tube 326 defining a guide wire lumen through which a guide wire 327 passes for delivering the balloon 324 to a desired location along the guide wire 327. A sheath (not shown) may surround the central tube and may define a delivery lumen through which inflation media, such as saline, can be controllably delivered for inflation of balloon 324. The lumen of the sheath may provide a concentric space around the central tube 326 within which electrode wires (not shown) can be run from the control 315 to the emitters 322 among other components. The sheath may be connected at a proximal end to a hub 317 that can include any number of ports allowing electrode wires to pass into the lumen along with saline for inflation, the guide wire 327, and any number of other components as desired.

[0023] In use, catheter 320 may be passed into the patient’s vasculature, and focused ultrasonic energy or shock waves are delivered from catheter 320 to the calcified tissue in an attempt to break up or otherwise disrupt calcification of the tissue. For example, an exemplary IVL procedure to treat aortic valve stenosis may involve positioning balloon 324 within the native aortic valve via intravascular delivery, and inflating the balloon with fluid in a fashion generally similar to the beginning of a valvuloplasty procedure. Specifically, balloon 324 may be placed in a deflated position so as to more readily pass through a patient's vasculature to arrive at the site of calcification. Upon reaching the appropriate site, balloon 324 may be inflated to a common pressure for angioplasty procedures (e.g., about 4 atm) and the therapy actuated via the delivery control 315. Here, balloon 324 may be operably coupled to a generator that can deliver energy to one or more lithotripsy emitters 322 positioned on the catheter within the balloon (or on the balloon) to deliver focused energy that can cause the calcium formations within the stenosed aortic valve to break apart or otherwise diminish, which may allow the aortic valve leaflets to open to a greater extent than possible prior to the IVL treatment.

[0024] The control 315 may be used to produce one or a series of voltage pulses in accordance with a treatment scheme. A high voltage pulse may be provided to one of the emitters 322 in accordance with the illustrated embodiment, then in series to a second emitter 322. The high voltage pulse may cause a spark across the first electrode pair then across the second electrode pair sequentially within the balloon 324. The somewhat conductive saline solution within the balloon 324 may permit the high voltage spark across each electrode pair, thus creating an energy wave that propagates within the balloon toward the calcification C within the blood vessel BV.ABTCSI-0001PCT

[0025] IVL system 300 may have a finite number of pulses (or applications of energy) before its components become compromised by the energy field. In some embodiments, certain emitter configurations may improve the energy transfer from the therapeutic device to the target (e.g., calcium deposits). Precisely controlling the application of energy may limit unintended effects on other adjacent anatomical features. Furthermore, it may help reduce the energy needed to achieve procedural success (e.g., sufficient breaking up of calcium), and thereby allow the device to last longer. As previously noted, the application of energy may be directed through emitters 322, and these emitters 322 may be in the form of electrodes. The shape, size and / or configuration of these electrodes may be manipulated to achieve more efficient energy transfer.

[0026] As shown in Fig. 3, the energy emitted may be enhanced by the shape of emitters 322 itself and / or a nearby reflective covering. Specifically, emitters 322 may be generally cone-shaped or megaphone-shaped with a narrow waist adjacent catheter 320 and an enlarged head further from catheter 320. In some examples, each emitter 322 has a diameter that gradually increases from a first end closest to a central axis XI of the catheter to a second end farther from the central axis of the catheter. The opposite is also possible where each emitter 322 has a diameter that gradually decreases from a first end closest to a central axis XI of the catheter to a second end farther from the central axis of the catheter. Without being bound by any particular theory, it is believed that the shape of the emitters 322 may direct, amplify, focus, and / or funnel the transferred energy “TE” into a particular region and / or focal point, while preventing the energy from being dispersed to other regions such that maximum energy transfer efficiency is achieved. This may provide a unidirectional focal point of energy, as opposed to a scattered application of energy. Further benefits may include the ability to more effectively shield critical components of the catheter so that it is not affected by the energy field.

[0027] Turning to Fig. 4A-4B, details of potential emitters will be described. In Fig. 4A, an emitter 422A may have a cone-shaped electrode body 450, the electrode body 450 having a narrow waist 451a and an enlarged mouth 452a. In this example, energy may be sent in the direction of arrows “E” from narrow waist 451a out through enlarged mouth 452a such that the energy is directed via a corresponding cone-shaped or funnel-shaped profile with body 450 acting as a guide. In Fig. 4B, an emitter 422B may have a flat or arc-shaped electrode body 450, and this body may be disposed within a separate funneling reflective component 460 having a narrow portion 461a and an enlarged portion 462a. In this example, energy may be sent in the direction of arrows “E” andABTCSI-0001PCT directed or guided by the shape of reflective component 460. In some examples, reflective component 460 may include polymers or metals. It will be understood that the shapes of electrode body 450 or reflective component 460 may be modified, and the diameter of the opening where the energy is emitted (e.g., mouth 452a, enlarged portion 462a) may be manipulated to control the application area in the anatomy (i.e., to increase or decreased the affected area). The reflective component(s) may also be designed such that there is a convergence of the energy at a specific diameter and / or depth outside of the delivery device. For example, Figs. 5A-5L show various configurations of reflecting components including emitter configurations that generally show a diverging energy profile (e.g., 522A, 522B, 522C, 522D, 522E, 522F) and emitter configurations that generally show a converging energy profile (e.g., 522G, 522H, 5221, 522J, 522K, 522L). As shown, each emitter includes an electrode 550 disposed within a directing reflecting component 560 of a particular shape (e.g., converging or diverging cones, funnels, megaphone shapes, etc.). It will be understood, however, that the electrodes themselves may be produced in any of these shapes without a separate reflecting component. Prisms, concave / convex surfaces, lens and other designs may also be possible.

[0028] Figs. 6A-6B show two further variations of the system. In Fig. 6A, IVL system 300 includes catheter 320, balloon 324 and two cone-shaped emitters 322 disposed back-to-back (or 180 degrees apart) at each axial position or level so that energy is directed through two contralateral portions 324’ of balloon 324. In some examples, four levels of pairs of emitters are disposed on the catheter for a total of eight emitters. It will be understood that the number of axial positions or levels may be varied. In Fig. 6B, a similar IVL system 300 is shown that includes catheter 320, balloon 324 and three cone-shaped emitters 322 disposed 120 degrees apart at each axial position or level so that energy is directed through three radially spaced portions 324” of balloon 324. It will be understood that the number of emitters and the spacing between the emitters at each longitudinal level may be varied as desired.

[0029] Fig. 7 illustrates an intravascular lithotripsy (“IVL”) system 700 similar to that of Fig. 3, which generally includes a power source (not shown), a handle (not shown), a catheter 720 supporting balloon 724 and a plurality of lithotripsy emitters 722 (shown in the form of flat electrodes, but alternatively they could comprise optical or laser emitters). Catheter 720 may include a central tube 726 defining a guide wire lumen through which a guide wire 727 passes for delivering the balloon 724 to a desired location along the guide wire 727. In this example, fourABTCSI-0001PCT emitters 722 are disposed on either side of the balloon, although the number and / or spacing between the emitters may be varied. A reflective material 770 may be disposed radially inward of emitters 722. In some examples, reflective material 770 may include a polymer and / or a metal. In some examples, the reflective material 770 is glued on, adhered to, or coated on catheter 720 or central tube 726, and is configured to focus energy radially outward from the delivery catheter. In this configuration the linearly arranged emitters 722 direct energy in all directions (i.e., radially inwards and outwards). Radially outward-directed energy el may continue to be directed outward through balloon 724. Meanwhile, radially-inward directed energy e2 may be reflected or bounce off of reflective material 770 and subsequently directed outward. In this manner, a greater portion of the total energy may be radially directed outward through balloon 724 onto a proper target, and this can be accomplished with simpler manufacturing and reduced costs.

[0030] Fig. 8 is a cutaway view showing the use of a system for providing intravascular lithotripsy 300 at an aortic valve 140 according to an aspect of the disclosure. In this example, IVL system 300, similar to system 300 of Fig. 3, is being used in a valvuloplasty procedure, whereby the catheter is passed over a guidewire through the vasculature of the patient (e.g., via aortic arch 120 or aorta 110) until the balloon, while deflated, is positioned within the diseased native heart valve. In this case, the valve to be treated is a diseased aortic valve 140 with three leaflets (only leaflets 140a, 140b being shown). At this point, the balloon is expanded with a fluid, typically a liquid such as saline (or a saline-contrast solution). The balloon is expanded until it contacts the diseased leaflets and / or valve annulus to fix the IVL system in position. Once in position, the generator 312 may be activated, for example using therapy control 315, in substantially the same manner as described above to cause the emitters 322 to generate energy, e.g., shockwaves, to break up or otherwise disrupt calcium in or on aortic valve leaflets 140a, 140b, 140c and / or calcium in or on the aortic valve annulus 141. While the balloon 324 is in its inflated condition, the outer cylindrical wall of the balloon 324 may be in contact with some or preferably all of the leaflets 140a, 140b, 140c, and optionally with surfaces of the annulus 141 as well. Meanwhile, emitters 322 may direct, amplify, focus, and / or funnel the transferred energy “TE” onto a particular region and / or focal point (e.g., a native leaflet or native valve annulus), while preventing the energy from being dispersed to other regions such that maximum energy transfer efficiency is achieved.

[0031] By performing IVL on a stenosed native heart valve using system 300 (or any of the other alternate examples described herein), removal or disruption of calcium may either (i) eliminate theABTCSI-0001PCT need (at least temporarily, if not permanently) for more invasive treatments such as implanting a transcatheter prosthetic heart valve (TAVI) or surgical removal of calcification from the leaflets, or (ii) enhance the effectiveness of more invasive treatments such as implanting a surgical prosthetic heart valve with surgical removal of calcification from the leaflets, if the more invasive treatments are still performed following IVL treatment.

[0032] Moreover, it will be understood that this procedure may be performed at different sites. For example, Fig. 9 is a cutaway view showing the use of an IVL system 700 at a mitral valve 130 according to an aspect of the disclosure. In this example, the IVL system 700 is similar to that of Fig. 7, in that the system has emitters 722 and an inner reflective material 770. Here, pairs of emitters at each level of IVL system 700 may be positioned with each emitter being directed to a corresponding native leaflet. In this example, the IVL system 700 has no balloon. Thus, it will be understood that some or many of the features described above with respect to the IVL systems may be optional, and that the preceding description is merely exemplary.

[0033] Although the IVL systems described herein are generally shown and described for use with treating aortic valve stenosis, it should be understood that stenosis of other heart valves, including the pulmonary valve, mitral valve, or tricuspid valve, may be performed in substantially the same fashion using the IVL systems described herein. Further, it should be understood that the IVL systems described herein may be advanced to the treatment site in any suitable fashion. For example, if an IVL system is being used to treat aortic valve stenosis, it may be advanced along a retrograde transfemoral route so that the distal end of the balloon is positioned on the inflow side of the aortic valve and the proximal end of the balloon is positioned on the outflow side of the aortic valve. In other examples, the IVL system, when used to treat the aortic valve, may be advanced along a transapical route so that the proximal end of the balloon is positioned on the inflow side of the aortic valve and the distal end of the balloon is positioned on the outflow side of the aortic valve.

[0034] Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims.

Claims

ABTCSI-0001PCTCLAIMS1. A method of treating a native heart valve, the method comprising: providing an intravascular lithotripsy having an energy source, a catheter operably coupled to the energy source, a balloon disposed over a portion of the catheter, and at least one lithotripsy emitter coupled to the catheter and having a funnel shape; inflating the balloon within the native heart valve; generating energy from the energy source; and funneling the energy onto a native leaflet or a native aortic annulus via the funnel shape of the at least one lithotripsy emitter while preventing the energy from being dispersed to other regions.

2. The method of treating a native heart valve of claim 1 , wherein the at least one lithotripsy emitter has a diameter that gradually increases from a first end closest to a central axis of the catheter to a second end farther from the central axis of the catheter.

3. The method of treating a native heart valve of claim 1 , wherein the at least one lithotripsy emitter has a diameter that gradually decreases from a first end closest to a central axis of the catheter to a second end farther from the central axis of the catheter.

4. The method of treating a native heart valve of claim 1 , wherein the at least one lithotripsy emitter is not flat.

5. The method of treating a native heart valve of claim 1 , wherein the at least one lithotripsy emitter is cone-shaped.

6. The method of treating a native heart valve of claim 1 , wherein the at least one lithotripsy emitter includes a cone-shaped electrode body having a narrow waist and an enlarged mouth, and wherein funneling the energy onto a native leaflet comprises directing energy outward of the enlarged mouth.ABTCSI-0001PCT7. The method of treating a native heart valve of claim 1 , wherein the at least one lithotripsy emitter includes an electrode body disposed within a focusing reflecting component.

8. The method of treating a native heart valve of claim 7, wherein the reflecting component comprises a metal or a polymer.

9. The method of treating a native heart valve of claim 7, wherein the reflecting component includes a narrow portion and an enlarged portion, and wherein funneling the energy onto a native leaflet comprises directing energy outward of the enlarged portion.

10. The method of treating a native heart valve of claim 1, wherein the at least one lithotripsy emitter comprises multiple lithotripsy emitters arranged at various axial levels.

11. The method of treating a native heart valve of claim 10, wherein the at least one lithotripsy emitter comprises multiple lithotripsy emitters arranged in four axial levels.

12. The method of treating a native heart valve of claim 10, wherein the at least one lithotripsy emitter comprises two lithotripsy emitters disposed 180 degrees apart at each axial level, and further comprising the step of positioning each of the two lithotripsy emitters with a corresponding leaflet of a native mitral valve13. The method of treating a native heart valve of claim 10, wherein the at least one lithotripsy emitter comprises three lithotripsy emitters, and further comprising the step of positioning each of the three lithotripsy emitters with a corresponding leaflet of a native aortic valve.

14. An intravascular lithotripsy catheter system for use in treating a native heart valve, the catheter system comprising: an energy source; a catheter operably coupled to the energy source; at least one lithotripsy emitter coupled to the catheter; andABTCSI-0001PCT a reflective material disposed radially inward of the at least one lithotripsy emitter, and being configured to reflect energy from the at least one lithotripsy emitter onto a native leaflet or a native annulus of the native heart valve.

15. The intravascular lithotripsy catheter system of claim 14, wherein the reflecting material comprises a metal or a polymer.

16. The intravascular lithotripsy catheter system of claim 14, wherein the reflecting material is coupled to a central tube of the catheter.

17. The intravascular lithotripsy catheter system of claim 14, wherein the reflecting material is coated onto a portion of the catheter.

18. The intravascular lithotripsy catheter system of claim 14, wherein the at least one lithotripsy emitter comprises multiple lithotripsy emitters arranged at various axial levels.

19. The intravascular lithotripsy catheter system of claim 18, wherein the at least one lithotripsy emitter comprises two lithotripsy emitters arranged at four axial levels.

20. The intravascular lithotripsy catheter system of claim 18, wherein the reflecting material is cylindrical and configured to reflect energy from the multiple lithotripsy emitters.

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