WO2026029963A1 - Balloon and energy transfer design for calcium disruption - Google Patents

Abstract

An intravascular lithotripsy ("IVL") catheter system (300) for use in directing energy to tissue of a heart valve may include an energy source (312), a catheter (320), two shafts (320a, 320b) each carrying one or more lithotripsy emitters (322a, 322b), and a balloon (324). The balloon may have an inflated condition with a tubular shape, with the one or more lithotripsy emitters being positioned within the balloon. When inflated, an inner wall of the balloon may defines an inflow end to be positioned adjacent an inflow end of the heart valve, am outflow end to be positioned adjacent an outflow end of the heart valve, and an open interior space (350) to be positioned within the heart valve. The open interior space may allow blood to flow from the inflow end of the balloon to the outflow end of the balloon through the open interior space.

Description

Balloon and Energy Transfer Design for Calcium Disruption

Cross-Reference to Related Applications

[0001] This application claims the benefit of priority to U.S. Provisional Patent Application No. 63/678,719, 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 overtime, 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] According to one aspect of the disclosure, an intravascular lithotripsy (“IVL”) catheter system is for use in directing energy to tissue of a heart valve. The IVL catheter system may include an energy source, a catheter operably coupled to the energy source, a first shaft extending from a distal portion of the catheter, and a second shaft extending from the distal portion of the catheter. A portion the first shaft may carry a first lithotripsy emitter, and a portion of the second shaft may carry a second lithotripsy emitter. A balloon may be positioned at a distal end portion of the catheter system. The balloon may have an inflated condition in which the balloon has a tubular shape including an outer cylindrical wall and an inner cylindrical wall. The portion of the first shaft carrying the first lithotripsy emitter may be positioned between the outer cylindrical wall and the inner cylindrical wall of the balloon, and the portion of the second shaft carrying the second lithotripsy emitter may be positioned between the outer cylindrical wall and the inner cylindrical wall of the balloon. In the inflated condition of the balloon, the inner cylindrical wall of the balloon may define a first inflow end configured to be positioned adjacent an inflow end of the heart valve, a second outflow end configured to be positioned adjacent an outflow end of the heart valve, and an open interior space configured to be positioned within an annulus of the heart valve. The open interior space may be sized and shaped to allow blood to flow from the first inflow end of the balloon to the second outflow end of the balloon through the open interior space. The balloon may include a proximal face, and the first shaft and the second shaft may each enter the balloon through the proximal face of the balloon. The first shaft and second shaft may each terminate within the balloon. The balloon may include a distal face, and the first shaft and the second shaft may each exit the balloon through the distal face of the balloon and converge to an atraumatic distal tip.

[0004] The heart valve may have an effective orifice area (“EOA”), and the balloon may be sized and shaped so that when the balloon is in the inflated condition within the heart valve, the open interior space defines an area for blood flow that is at least 50% of the EOA. The balloon may be sized and shaped so that when the balloon is in the inflated condition within the heart valve, the defined area for blood flow is between 100% and 250% of the EOA. The balloon may be sized and shaped so that when the balloon is in the inflated condition within the heart valve, the defined area for blood flow is at least 100% of the EOA. The balloon may include a temporary valve within the open interior space of the balloon, the temporary valve configured to restrict blood from flowing from the second outflow end of the balloon to the first inflow end of the balloon through the open interior space. The temporary valve may include one or more prosthetic leaflets mounted to an interior surface of the inner cylindrical wall of the balloon. The one or more prosthetic leaflets may be formed of pericardial tissue. The one or more prosthetic leaflets may be formed of a synthetic polymer. The balloon may include at least one temporary pump component within the open interior space of the balloon, the at least one temporary pump component configured to provide pulsatile blood flow from the first inflow end of the balloon to the second outflow end of the balloon through the open interior space. The at least one temporary pump component may be an impeller. The impeller may be operably coupled to the energy source.

[0005] According to another aspect of the disclosure, an intravascular lithotripsy (“IVL”) catheter system may be for use in directing energy to a leaflet of a heart valve. The IVL catheter system may include an energy source, a catheter operably coupled to the energy source, a first shaft extending from a distal portion of the catheter, and a second shaft extending from the distal portion of the catheter. A portion the first shaft may carry a first lithotripsy emitter, and a portion of the second shaft may carry a second lithotripsy emitter. A first balloon may be positioned at a distal end portion of the catheter system, the first balloon having an outer wall and an inner wall, the portion of the first shaft carrying the first lithotripsy emitter being positioned between the outer wall and the inner wall of the first balloon. A second balloon may be positioned at a distal end portion of the catheter system, the second balloon having an outer wall and an inner wall, the portion of the second shaft carrying the first lithotripsy emitter being positioned between the outer wall and the inner wall of the second balloon. In a first use condition of the IVL catheter system, the first balloon and the second balloon may be spaced apart a first distance from each other to define a leaflet-receiving space, the first distance being larger than a thickness of the leaflet. The IVL catheter system may be configured to transition to a second use condition in which the first balloon and the second balloon are spaced apart a second distance from each other, the second distance being about equal to the thickness of the leaflet. The first shaft and the second shaft may be formed of a shape memory material, and the first shaft and second shaft may be shape set so that, in the absence of applied forces, the IVL catheter system has the first use condition. The catheter may include a main shaft, and the first shaft and the second shaft may extend through an interior portion of the main shaft, the main shaft being configured to translate distally relative to the first shaft and the second shaft to transition the IVL catheter system from the first use condition to the second use condition. While the IVL catheter system is in the second use condition, the first balloon and the second balloon may be configured to cooperatively grasp the leaflet therebetween. The first balloon may include a proximal face, the second balloon may include a proximal face, the first shaft may enter the first balloon through the proximal face of the first balloon, and the second shaft may enter the second balloon through the proximal face of the second balloon. The first shaft may terminates within the first balloon, and the second shaft may terminate within the second balloon.

Brief Description of the Drawings

[0006] Fig. l is a cutaway view of a simplified representation of a human heart.

[0007] Figs. 2A-2B show examples of a healthy aortic valve when closed and open, respectively. [0008] Figs. 2C-2D show examples of a stenosed aortic valve when closed and open, respectively. [0009] Fig. 3 illustrates a prior art system for providing intravascular lithotripsy.

[0010] Fig. 4 illustrates the system of Fig. 3 in an exemplary use within a blood vessel.

[0011] Fig. 5 illustrates a system for providing intravascular lithotripsy according to an aspect of the disclosure.

[0012] Fig. 6 illustrates the system of Fig. 5 in an exemplary use within an aortic valve, with certain components of the system omitted for clarity of illustration.

[0013] Fig. 7 illustrates a system similar to the system of Fig. 5, but including a temporary valve, in an exemplary use within an aortic valve, with certain components of the system omitted for clarity of illustration.

[0014] Fig. 8 illustrates a system similar to the system of Fig. 5, but including a temporary pump, in an exemplary use within an aortic valve, with certain components of the system omitted for clarity of illustration.

[0015] Fig. 9 illustrates a system for providing intravascular lithotripsy according to an aspect of the disclosure.

[0016] Fig. 10 illustrates the system of Fig. 9 in an exemplary use within an aortic valve, with certain components of the system omitted for clarity of illustration. Detailed Description of the Disclosure

[0017] 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 left 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.

[0018] 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 dual-leaflet valve that opens as a result of a pressure differential in which the pressure in the left atrium 122 as it fdls with blood increases and the pressure in the left ventricle 124 decreases due to ventricular relaxation. 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 (z.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.

[0019] 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.

[0020] 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, shown 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.

[0021] 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. In either case, the diseased native leaflets may need to be resected (i.e. removed) prior to implanting the prosthetic heart valve, although such leaflet resection is by no means required in all cases (and such leaflet resection is typically not performed in TAVR cases).

[0022] 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.

[0023] Another technique that has gained recent interest is intravascular lithotripsy (“IVL”). Generally, IVL is a treatment in which a catheter device is passed into the patient’ s vasculature, and focused ultrasonic energy or shock waves are delivered from the catheter device 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 a balloon catheter 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. However, the balloon catheter may be operably coupled to a generator that can deliver energy to one or more electrodes 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. Examples of devices to perform IVL are provided in U.S. Patent Application Publication Nos. 2016/0135828 and 2022/028773, the disclosures of which are hereby incorporated by reference herein.

[0024] Fig. 3 shows an example of a prior art IVL system 200, and Fig. 4 shows the IVL system 200 in an exemplary use condition. IVL system 200 is described in U.S. Patent Application Publication No. 2024/0206896, the disclosure of which is hereby incorporated by reference herein. Fig. 3 shows the IVL system 200 which may include a power source 212 (e.g., in the form of an electrical generator or a laser system), a handle 214 with therapy delivery control 215 and a catheter 220 with two lithotripsy emitters 222 (shown in the form of a pair of arcing electrodes, but alternatively they could comprise optical or laser emitters), and a fluid filled balloon 224. Optional marker bands 225, which may be, for example, radiopaque markers, may be provided. The catheter 220 may include a central tube 226 defining a guide wire lumen through which a guide wire 227 passes for delivering the balloon 224 at the desired location along the guide wire 227. A sheath 228 may surround the central tube 226 and may define a delivery lumen 229 through which inflation media, such as saline, can be controllably delivered for inflation of balloon 224. The lumen 229 may provide a concentric space around the central tube 226 within which electrode wires (not shown) can be run from the control 215 to the emitters 222 among other components. The sheath 228 may be connected at a proximal end to a hub 217 that can include any number of ports allowing electrode wires to pass into the lumen 227 and/or 229 along with saline for inflation, the guide wire 227, and any number of other components as desired.

[0025] The balloon 224 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. In use, the balloon 224 may be inflated to a common pressure for angioplasty procedures (e.g. about 4 atm) and the therapy actuated via the delivery control 215.

[0026] Fig. 4 shows the balloon 224 inflated to a therapy delivery state where the lithotripsy emitters 222 may be “fired” to disrupt the vessel calcification C. Optional indicator bands 225 may be provided to afford visualization and proper positioning by use of known imaging techniques. The balloon 224 may be inflated to a typical angioplasty pressure (e.g. 4 atm) and therapy is delivered. The balloon 224 may naturally expand during or just after the therapy is delivered to clear the vessel for passage of blood.

[0027] The control 215 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 222 comprising a pair of spaced electrodes and, in accordance with the illustrated embodiment, then in series to a second emitter 222 also comprising a pair of spaced electrodes. The high voltage pulse may cause a spark across the first electrode pair then across the second electrode pair sequentially within the balloon 224. The somewhat conductive saline solution within the balloon 224 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.

[0028] Although IVL system 200 may be well-suited to treat calcification in various different blood vessels, treatment of heart valves, and in particular the aortic valve 140, using IVL system 200 may be more problematic. For example, if balloon 224 were inflated within the aortic valve 140 to contact the valve annulus 141 and the valve leaflets 140a, 140b, 140c, the inflated balloon 224 would mostly or entirely block flow of blood through the aortic valve 140. Because blood flowing through the aortic valve 140 is fed to the majority of the body (other than the lungs) to deliver oxygen, the amount of time that the balloon 224 may remain inflated within the aortic valve 140 for delivery of treatment is limited. In other words, permanent damage may result to the patient if the aortic valve 140 remains blocked for any extended amount of time. Further, because the heart will attempt to continue to beat while the balloon 224 is blocking the aortic valve 140, rapid pacing may be necessary to effectively stop the heart from beating temporarily while treatment is delivered. Although rapid pacing may be performed in different ways, in one example, a temporary pacemaker is used to pace the heart at a very high rate, which effectively results in the heart not producing significant contractions, due to the rapidity of the pacing, while the rapid pacing is applied. Although rapid pacing is commonly performed in procedures, including transcatheter heart valve replacements, rapid pacing is a known stressor to the heart and can lead to temporary or even permanent damage to the heart. Thus, it would be preferable to be able to perform IVL to treat calcified heart valves without the need to perform rapid pacing, or otherwise with only needing a minimal amount of rapid pacing during the procedure.

[0029] Fig. 5 illustrates a system 300 for providing IVL therapy, including to a heart valve, that is generally similar to system 200 with one main exception being the configuration of the balloon 324. For example, system 300 may include a generator 312 similar or identical to generator 212, a handle 314 similar or identical to handle 214, and a therapy delivery control 315 similar or identical to therapy delivery control 215. Further, system 300 may include a hub 317 similar or identical to hub 217, and a catheter 320 extending from the hub 317. Catheter 320 may be generally similar to catheter 220, but may split into two or more shafts or legs 320a, 320b proximal to the balloon 324. The shafts or legs 320a, 320b may be branches of the main catheter 320, or otherwise may be separate shafts (or portions of a separate shaft) that extend through the interior of the main catheter 320. Balloon 324 may be an expandable balloon that is configured to be filled with a fluid, including a liquid such as saline, with the expanded outer diameter of the balloon 324 being sufficient to contact the inner surface of an annulus and/or leaflets of a heart valve, including annulus 141 and/or leaflets 140a, 140b, 140c of aortic valve 140. However, unlike balloon 224, balloon 334 takes the general shape of a hollow cylinder, which may generally include an inner cylindrical wall, an outer cylindrical wall, a proximal annular face, and a distal annular face. With this configuration, a substantially open area 350 is defined within the inner cylindrical wall and between the proximal and distal face of the balloon 324 when expanded. [0030] Still referring to Fig. 5, each of the two legs 320a, 320b of catheter 320 may extend through the balloon 324, for example at substantially diametrically opposed ends thereof, between the inner wall and outer wall of the balloon 324. In the particular illustrate example, each leg 320a, 320b may exit the balloon 324 at a distal face thereof, and extend distally to converge at an atraumatic tip 360. Similar to system 200, system 300 may include lithotripsy emitters 322a, 322b and optional marker bands 325a, 325b to assist with treating calcified tissue. For example, two emitters 322a may be positioned on one leg 320a of the catheter 320 within the interior volume of the balloon 324, and two emitters 322b may be positioned on the other leg 320b of the catheter 320 within the interior volume of the balloon 324. A pair of optional marker bands 325a may be positioned on the first leg 320a of the catheter 320 within the interior volume of the balloon 324, and a pair of optional marker bands 325b may be positioned on the second leg 320b of the catheter 320 within the interior volume of the balloon 324. The emitters 322a, 322b may be substantially similar or identical to emitters 222 of system 200, and thus are not described in greater detail herein.

[0031] Fig. 6 illustrates certain portions of system 300 in an exemplary use condition in aortic valve 140, with various components of the system 300 omitted for clarity of illustration. In particular, the only components of the system 300 shown in Fig. 6 are the balloon 324, shown in an inflated condition, and emitters 322a, 322b. The generator 312 may be activated, for example using therapy control 315, in substantially the same manner as described in connection with Figs. 3-4 to cause the emitters 322a, 322b 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. Importantly, because the inflated balloon 324 has a tubular shape that defines a substantially continuous open area 350, blood flow through the aortic valve 140 is not entirely blocked during treatment. Rather, blood may continue to flow in the antegrade direction B through the open area 350.

[0032] The configuration of balloon 324 and emitters 322 in system 300 may provide one or more benefits. First, compared to the emitters 222 of system 200, the emitters 322a, 322b of system 300 may be positioned more closely to the target tissue (e.g. the aortic valve leaflets 140a, 140b, 140c). This closer positioning may allow for more efficient transfer of energy from the emitters 322a, 322b to the calcium of the leaflets 140a, 140b, 140c, to more effectively break up or otherwise disrupt the calcium. Second, compared to the balloon 224 of system 200, the balloon 324 of system 300 allows for blood to flow across the aortic valve 140 during the time in which the balloon 324 is inflated and energy is being transmitted by the emitters 322a, 322b to the leaflets 140a, 140b, 140c. Because balloon 324 allows the flow of blood to occur during treatment, the need for rapid pacing may be reduced or eliminated, which may also allow for an increased treatment time which may produce better results in terms of calcium breakup or disruption within the leaflets 140a, 140b, 140c. However, because retrograde flow through the balloon 324 may still be possible in the specific embodiment shown in Fig. 6, a main benefit may be the reduction or elimination of rapid pacing compared to increased treatment time. A typical treatment time may be, for example, between about 10 and about 30 seconds, including about 20 seconds. However, in other embodiments described herein (including, for example, the valved embodiment of Fig. 7, the pump embodiment of Fig. 8, and the clip/grasper embodiment of Figs. 9-10, treatment time may be significantly increased, if desired, including more than about 20 seconds, more than about 30 seconds, more than about 40 seconds, more than about 50 seconds, or more than about 1 minute).

[0033] Although system 300 includes a catheter 320 that is shown as having two legs 320a, 320b, it may include more than two legs, preferably as long as the legs diverge in a way that allow an interior space through which blood may flow substantially unimpeded. In some examples, it may be preferable to include three legs that are substantially evenly spaced (e.g. at about 120 degree intervals), with each leg carrying one or more emitters so that one leg having one or more emitters may be positioned directly against a corresponding one of each of the three native aortic valve leaflets (or against corresponding ones of the three tricuspid valve or pulmonary valve leaflets).

[0034] In the illustrated example of Fig. 5, the legs 320a, 320b of catheter 320 extend beyond the distal face of the balloon 324 and converge to an atraumatic distal tip 360, which may help guide the catheter 320 through the vasculature. In some examples, a guidewire similar to guidewire 227 may be configured to extend through catheter 320, and through the open area 350 of the balloon 324 and into and through the atraumatic distal tip 360 to assist with guidance. Even if the guidewire is used, it is small enough as to not meaningfully obstruct the flow of blood through the open space 350 of the balloon 324 during treatment. In other embodiments, the atraumatic tip 360 may be entirely omitted with the legs 320a, 320b of the catheter 320 terminating within the interior volume of the balloon between the outer and inner walls.

[0035] It should be understood that the balloon 324 is preferably mostly or entirely fluid-tight so that it is capable of remaining inflated during treatment. In some examples, the balloon 324 may be formed with apertures in the proximal face through which legs 320a, 320b, and the material of the balloon 324 may be sealed around the legs 320a, 320b by any suitable mechanism, including adhesives, welding, and the like. If the lets 320a, 320b pass through a distal face of the balloon 324, similar apertures and sealing may be provided. For example, the legs 320a, 320b may be passed through the proximal and distal faces of the balloon 324 and thereafter joined to the atraumatic distal tip 360, with the material of the balloon 324 being sealed against the legs 320a, 320b just prior to or after being joined to the distal tip 360.

[0036] In some examples, the legs 320a, 320b may be formed of a material that has shape-memory properties, including polymers and/or metal or metal alloys such as nitinol. If the legs 320a, 320b are formed of a shape memory material, they may be set to the expanded shape shown in Fig. 5. In some examples, if the legs 320a, 320b are set to the expanded shape, the legs 320a, 320b and/or the balloon 324 may be retractable into an overlying sheath, including catheter 320 or another sheath that overlies catheter 320, to help maintain the balloon 324 and the legs 320a, 320b in a small profile collapsed condition for minimally invasive delivery. In other examples, if the legs 320a, 320b are formed of a shape memory material, they may be shape set to a collapsed condition in which the legs 320a, 320b are positioned close to each other to achieve a small profile for transvascular delivery. In these examples, as the balloon 324 is inflated, it will tend to take the cylindrical or tubular shape shown in Figs. 5-6, with the force of the balloon expansion tending to pull the legs 320a, 320b away from their collapsed setshape into the condition shown in Fig. 5. In still other examples, the legs 320a, 320b may not be formed of a shape memory material, and the force from inflation or deflation of the balloon 324 will tend to pull the legs 320a, 320b away from each other (when the balloon 324 is being inflated) or to push the legs 320a, 320b toward each other (when the balloon 324 is being deflated). It should also be understood that one or more lumens may extend through an interior of the legs 320a, 320b with one or more openings positioned in the interior volume of the balloon 324 between the outer and inner cylindrical walls to allow for inflation media, which may be a fluid, including a liquid, including for example saline (or a saline and contrast solution) to pass into or out of the balloon 324 for inflation or deflation, respectively. In other embodiments, one or more dedicated inflation lumens may be provided in separate tubes that are not part of the legs 320a, 320b but which extend from the hub 317 to the balloon 324.

[0037] By performing IVL on a stenosed native heart valve using system 300 (or any of the other alternate examples described herein that allow for continued blood flow through the heart valve), removal or disruption of calcium may either (i) eliminate the need (at least temporarily of not permanently) for more invasive treatments such as implanting a prosthetic heart valve or surgical removal of calcification from the leaflets, or (ii) enhance the effectiveness of more invasive treatments such as implanting a prosthetic heart valve of surgical removal of calcification from the leaflets, if the more invasive treatments are still performed following IVL treatment. And as noted above, these benefits may be achieved while simultaneously minimizing or eliminating the risk of rapid pacing during the IVL procedure.

[0038] It should be understood that, in prior art systems such as IVL system 200, due to imperfect fit between the balloon 224 and the interior periphery of the annulus of the heart valve, some small amount of blood flow may still be possible across the valve during IVL treatment. However, with the embodiments described herein, more than 50%, more than 60%, more than 70%, more than 80%, more than 90%, including up to about 95% of the pre-treatment effective orifice area (“EGA”) of the heart valve may remain available for blood flow during IVL treatment. In fact, because the balloon 324 (or other balloon described herein) may push the native leaflets farther outwardly than they may be able to achieve naturally given the level of stenosis, up to 100% or even more of the pre-treatment EGA of the heart valve may remain available for blood flow during IVL treatment. For example, given that the patients receiving this treatment typically have stenosed leaflets, the EGA during treatment may be significantly greater than the pre-treatment EGA, including the peri -procedural EGA being up to about 250% of the pre-treatment EGA, although smaller numbers such as up to about 200%, or up to about 150%, are also possible.

[0039] Although the tubular shape of balloon 324 may allow for blood to flow across the valve being treated during treatment, the blood may be free (or mostly free) to flow in either the antegrade or retrograde direction depending on the particular phase of the beating heart. Thus, in some examples, a temporary valve may be provided with balloon 324 to create more optimized hemodynamics during treatment in which retrograde blood flow through the balloon 324 is mostly or entirely prevented. For example, Fig. 7 illustrates a balloon 324’ that may be similar or identical to balloon 324 (other than the temporary valve and any features directly related thereto) and which may be used in a system that is similar or otherwise identical to system 300. As shown in Fig. 7, the balloon 324’ may include one or more valve leaflets 360a’, 360b’, mounted within the open space 350’ defined by the inner cylindrical wall of the balloon 324’. In the illustrated example, two leaflets 360a’, 360b’ are provided to form the temporary valve. However, in other embodiments a single leaflet, or more than two leaflets, may be provided to form the temporary valve. If the temporary valve takes the form of one or more leaflets, the one or more leaflets may be formed of any suitable leaflet material, including known materials for prosthetic heart valve leaflets, such as tissue materials (including treated and/or fixed bovine or porcine pericardial tissue) or synthetic materials (such as polymers formed as woven or knitted fabrics or as polymer sheets). If the temporary valve is formed from one or more leaflets, the leaflets may each have a base that is fixed to interior surface of the inner cylindrical wall of the balloon 324’, for example by adhesives, and a free end that acts to coapt with free ends of other leaflets similar to the function of the native leaflets 140a, 140b, 140c. If a single leaflet 360a’ is provided, it may have a free edge that coapts with the interior surface of the inner cylindrical wall of the balloon 324’. In other examples, the temporary valve may be formed in a configuration that does not use separate leaflets, such as a duckbill valve. A system that incorporates balloon 324’ instead of balloon 324 may be used in a similar or identical way as described in connection with system 300, with the added benefit that the temporary valve may allow for better hemodynamics, including avoiding loss of blood pressure, during the procedure. It should be understood that, following the IVL procedure, the temporary valve is removed with the balloon 324’ from the patient.

[0040] While a temporary valve, similar to that shown in Fig. 7, is one option for allowing blood to flow with improved hemodynamics during an IVL treatment procedure, another option is the use of a temporary blood pump. For example, Fig. 8 illustrates a balloon 324” that may be similar or identical to balloon 324 (other than the temporary pump and any features directly related thereto) and which may be used in a system that is similar or otherwise identical to system 300. As shown in Fig. 8, the balloon 324’ ’ may include a pump component, which may be for example an impeller 360”, mounted within the open space 350” defined by the inner cylindrical wall of the balloon 324”. Although not shown in Fig. 8, a separate shaft may be connected to the impeller 360’ ’ and extend back to hub 317 and/or generator 312, which may provide power and controls to the impeller 360” through a dedicated shaft. A system that incorporates balloon 324” instead of balloon 324 may be used in a similar or identical way as described in connection with system 300, with the added benefit that the impeller 360” may be activated to create a temporary pump in which pulsatile blood flow may be provided to the patient during the IVL procedure. It should be understood that, following the IVL procedure, the temporary pump is removed with the balloon 324” from the patient. Although Fig. 8 illustrates a pump component such as an impeller 360” within the interior open space 350” of the balloon 324”, in other examples, a minimally invasive pump may be provided as part of the catheter 320. Minimally invasive blood pumps are described in greater detail in U.S. Patent Nos. 9,872,948 and 10,808,704, the disclosures of which are hereby incorporated by reference herein. In still other examples, instead of incorporated a minimally invasive blood pump into balloon 324” (or a catheter coupled thereto), an entirely separate minimally invasive blood pump may be used simultaneously with system 300 to achieve a similar effect of pulsatile blood flow being provided during IVL treatment.

[0041] The embodiments shown and described in connections with Figs. 5-8 generally include a tubular balloon that allows for blood to flow through the interior of the balloon during IVL treatment. Figs. 9-10, on the other hand, include an example in which IVL treatment may be provided to an individual leaflet of the heart valve while still allowing the remaining leaflets to function coapt such that pulsatile blood flow may continue during IVL treatment. For example, Fig. 9 illustrates a system 400 for providing IVL therapy, including to one or more leaflets of a heart valve, that is generally similar to systems 200 and 300 with one main exception being the configuration of the balloon. For example, system 400 may include a generator 412 similar or identical to generators 212 and 312, a handle 414 similar or identical to handles 214 and 314, and a therapy delivery control 415 similar or identical to therapy delivery controls 215 and 315. Further, system 400 may include a hub 417 similar or identical to hubs 217 and 317, and a catheter 420 extending from the hub 417. Catheter 420 may be generally similar to catheter 320, but with two or more catheter legs 420a, 420b proximal to the balloon(s). The balloon(s) may be provided as two separate ballons 424a, 424b which are each expandable balloons that are configured to be filled with a fluid, including a liquid such as saline.

[0042] Still referring to Fig. 9, each of the two legs 420a, 420b of catheter 420 may extend into their respective balloons 424a, 424b. In the particular illustrate example, each leg 420a, 420b may enter the corresponding balloon 424a, 424b at a distal face thereof, and terminate within the interior confines of the respective balloon 424a, 424b. Similar to system 300, system 400 may include lithotripsy emitters 422a, 422b and optional marker bands 425a, 425b to assist with treating calcified tissue. For example, two emitters 422a may be positioned on one leg 420a of the catheter 420 within the interior volume of the balloon 424a, and two emitters 422b may be positioned on the other leg 420b of the catheter 420 within the interior volume of the balloon 424b. A pair of optional marker bands 425a may be positioned on the first leg 420a of the catheter 420 within the interior volume of the balloon 424a, and a pair of optional marker bands 425b may be positioned on the second leg 420b of the catheter 420 within the interior volume of the balloon 424b. The emitters 422a, 422b may be substantially similar or identical to emitters 222 of system 200, and thus are not described in greater detail herein.

[0043] Each balloon 424a, 424b may have a generally flat or partially curved shape when expanded with inflation media. In a first condition of use, the legs 420a, 420b may force the balloons 424a, 424b to splay apart to define an interior open space 450 which, as shown in Fig. 10, may be configured to accept one of the leaflets of the valve being treated, such as leaflet 140a of the aortic valve 140. As shown in Fig. 10, the catheter 420 may be delivered intravascularly until the balloons 424a, 424b are positioned on either side of the leaflet 140a to be treated. Either prior to the balloons 424a, 424b being positioned on opposite side of the leaflet 140a, or after such positioning, the balloons 424a, 424b may be inflated with inflation media, for example by forcing inflation media through an interior inflation lumen of each leg 420a, 420b, with the portion of the legs 420a, 420b within the interior boundary of the balloons 424a, 424b having one or more openings to allow the inflation media to enter into and inflate the balloons 424a, 424b. The legs 420a, 420b and thus the balloons 424a, 424b may be reconfigured to pinch or clamp over the leaflet 140a to be treated, for example to maintain the leaflet 140a in a mostly static position relative to the balloons 424a, 424b (and thus the emitters 422a, 422b) during IVL treatment. [0044] In one example, the legs 420a, 420b may be formed at least partially of a shape memory material, such as a polymer or metal or metal alloy like Nitinol, with the legs 420a, 420b being positioned relatively far from each other in the absence of applied forces to form the open space 450. In this example, an overlying catheter, which may be catheter 420 or another overlying catheter, may be advanced relative to legs 420a, 420b to force the legs 420a, 420b to pinch together (reducing the size of the open space 450) while the leaflet 140a to be treated is positioned between the legs 420a, 420b (and thus between the balloons 424a, 424b). Once the leaflet 140a is confirmed to be pinched or clamped between the balloons 424a, 424b, which confirmation may be performed under visualization (with or without the aid of marker bands 425a, 425b), the balloons 424a, 424b may be inflated if they have not already been previously inflated. It may be preferably to inflate the balloons 424a, 424b prior to pinching the leaflet 140a. With the balloons 424a, 424b inflated and the leaflet 140a trapped between the balloons 424a, 424b, the emitters 422a, 422b may be activated as described above to focus energy onto the leaflet 140a to break up, remove, or otherwise disrupt calcium of the leaflet 140a. It should be understood that, because the balloons 424a, 424b are not positioned within the annulus 141, blood my continue to flow through the aortic valve 140 during IVL treatment. Further, because only one leaflet is restrained, the other leaflet (in the case of a mitral valve) or the other leaflets (in the case of a tricuspid valve, such as leaflets 140b, 140c of aortic valve 140) may continue to open and close to provide pulsatile blood flow during the IVL treatment. It should be understood that the remaining leaflets may not fully coapt due to the first leaflet 140a being restrained, but nonetheless the remaining leaflets may provide suitable hemodynamics to allow for IVL treatment to occur without the need for rapid pacing (or with lesser need for rapid pacing) and for treatment to performed for a longer time period than would be possible with a system similar to system 200 (and/or compared to any other system that requires significant rapid pacing).

[0045] Although system 400 is shown with two individual legs 420a, 420b that include emitters 422a, 422b in a substantially one-dimensional layout, in other examples, two or more legs may be provided within each balloon 424a, 424b to provide a two-dimensional array of emitters which may provide for increased area of effective IVL treatment. Compared to system 300 (and variations thereof described herein), system 400 may be more suited to treating leaflet calcification than annular calcification. Further, although Fig. 10 illustrates treatment of a single leaflet 140a, it should be understood that the process may be repeated for one or more additional leaflets until the desired amount of IVL treatment has been performed. Once IVL treatment of the particular leaflet is completed, the leaflet may be released from being secured between the balloons 424a, 424b by withdrawing the legs 420a, 420b (and/or by withdrawing an overlying sheath relative to the legs 420a, 420b to allow the legs 420a, 420b to splay apart). Once the treated leaflet is released, the procedure may be repeated as desired for other leaflets, or otherwise the system may be fully withdrawn from the patient to complete the IVL procedure.

[0046] 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.

[0047] 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 IVL system 300 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 300, 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. IVL system 400, on the other hand, may be best suited to approach the leaflets of the heart valve being treated in a retrograde delivery route so that the balloons are best aligned to capture the free end(s) of the leaflet(s) being treated.

[0048] 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

1. An intravascular lithotripsy (“IVL”) catheter system for use in directing energy to tissue of a heart valve, the catheter system comprising: an energy source; a catheter operably coupled to the energy source; a first shaft extending from a distal portion of the catheter, a portion the first shaft carrying a first lithotripsy emitter; a second shaft extending from the distal portion of the catheter, a portion of the second shaft carrying a second lithotripsy emitter; and a balloon positioned at a distal end portion of the catheter system, the balloon having an inflated condition in which the balloon has a tubular shape including an outer cylindrical wall and an inner cylindrical wall, the portion of the first shaft carrying the first lithotripsy emitter being positioned between the outer cylindrical wall and the inner cylindrical wall of the balloon, the portion of the second shaft carrying the second lithotripsy emitter being positioned between the outer cylindrical wall and the inner cylindrical wall of the balloon, wherein in the inflated condition of the balloon, the inner cylindrical wall of the balloon defines a first inflow end configured to be positioned adjacent an inflow end of the heart valve, a second outflow end configured to be positioned adjacent an outflow end of the heart valve, and an open interior space configured to be positioned within an annulus of the heart valve, the open interior space being sized and shaped to allow blood to flow from the first inflow end of the balloon to the second outflow end of the balloon through the open interior space.

2. The IVL catheter system of claim 1, wherein the balloon includes a proximal face, and the first shaft and the second shaft each enter the balloon through the proximal face of the balloon.

3. The IVL catheter system of any of the preceding claims, wherein the first shaft and second shaft each terminate within the balloon.

4. The TVL catheter system of claim 1 or 2, wherein the balloon includes a distal face, and the first shaft and the second shaft each exit the balloon through the distal face of the balloon and converge to an atraumatic distal tip.

5. The IVL catheter system of any of the preceding claims, wherein the heart valve has an effective orifice area (“EOA”), the balloon being sized and shaped so that when the balloon is in the inflated condition within the heart valve, the open interior space defines an area for blood flow that is at least 50% of the EOA.

6. The IVL catheter system of claim 5, wherein the balloon is sized and shaped so that when the balloon is in the inflated condition within the heart valve, the defined area for blood flow is between 100% and 250% of the EOA.

7. The IVL catheter system of claim 5, wherein the balloon is sized and shaped so that when the balloon is in the inflated condition within the heart valve, the defined area for blood flow is at least 100% of the EOA.

8. The IVL catheter system of any of the preceding claims, wherein the balloon includes a temporary valve within the open interior space of the balloon, the temporary valve configured to restrict blood from flowing from the second outflow end of the balloon to the first inflow end of the balloon through the open interior space.

9. The IVL catheter system of claim 8, wherein the temporary valve includes one or more prosthetic leaflets mounted to an interior surface of the inner cylindrical wall of the balloon.

10. The IVL catheter system of claim 9, wherein the one or more prosthetic leaflets are formed of pericardial tissue.

11. The IVL catheter system of claim 9, wherein the one or more prosthetic leaflets are formed of a synthetic polymer.

12. The TVL catheter system of any of claims 1 -7, wherein the balloon includes at least one temporary pump component within the open interior space of the balloon, the at least one temporary pump component configured to provide pulsatile blood flow from the first inflow end of the balloon to the second outflow end of the balloon through the open interior space.

13. The IVL catheter system of claim 12, wherein the at least one temporary pump component is an impeller.

14. The IVL catheter system of claim 13, wherein the impeller is operably coupled to the energy source.

15. An intravascular lithotripsy (“IVL”) catheter system for use in directing energy to a leaflet of a heart valve, the catheter system comprising: an energy source; a catheter operably coupled to the energy source; a first shaft extending from a distal portion of the catheter, a portion the first shaft carrying a first lithotripsy emitter; a second shaft extending from the distal portion of the catheter, a portion of the second shaft carrying a second lithotripsy emitter; a first balloon positioned at a distal end portion of the catheter system, the first balloon having an outer wall and an inner wall, the portion of the first shaft carrying the first lithotripsy emitter being positioned between the outer wall and the inner wall of the first balloon; and a second balloon positioned at a distal end portion of the catheter system, the second balloon having an outer wall and an inner wall, the portion of the second shaft carrying the first lithotripsy emitter being positioned between the outer wall and the inner wall of the second balloon, wherein in a first use condition of the IVL catheter system, the first balloon and the second balloon are spaced apart a first distance from each other to define a leaflet-receiving space, the first distance being larger than a thickness of the leaflet, the IVL catheter system being configured to transition to a second use condition in which the first balloon and the second balloon are spaced apart a second distance from each other, the second distance being about equal to the thickness of the leaflet.

16. The IVL catheter system of claim 15, wherein the first shaft and the second shaft are formed of a shape memory material, the first shaft and second shaft being shape set so that, in the absence of applied forces, the IVL catheter system has the first use condition.

17. The IVL catheter system of claim 15 or 16, wherein the catheter includes a main shaft, and the first shaft and the second shaft extend through an interior portion of the main shaft, the main shaft being configured to translate distally relative to the first shaft and the second shaft to transition the IVL catheter system from the first use condition to the second use condition.

18. The IVL catheter system of any of claims 15-17, wherein while the IVL catheter system is in the second use condition, the first balloon and the second balloon are configured to cooperatively grasp the leaflet therebetween.

19. The IVL catheter system of any of claims 15-18, wherein the first balloon includes a proximal face, the second balloon includes a proximal face, the first shaft enters the first balloon through the proximal face of the first balloon, and the second shaft enters the second balloon through the proximal face of the second balloon.

20. The IVL catheter system of any of claims 15-19, wherein the first shaft terminates within the first balloon, and the second shaft terminates within the second balloon.