Methods and devices for modifying heart valve leaflets

Abstract

Systems, devices, and methods for percutaneously modifying valve leaflets in the heart, thereby facilitating further repair or replacement. In some embodiments, the leaflets are amputated. In other embodiments, the leaflets are partially or completely removed. The modification of the leaflets can be performed in conjunction with a prosthetic valve or independently.

Description

Related Applications

[0001] This application claims priority to U.S. Provisional Patent Application No. 62 / 933,007, entitled "Heart Valve Leaflet Modification," filed November 8, 2019, the entirety of which is hereby incorporated by reference. [Technical field]

[0002] The present disclosure relates to novel and advantageous transcatheter-delivered valve repair devices, more specifically, devices that address problems associated with treating pathologies involving heart valves, such as the mitral, aortic, pulmonary, and tricuspid valves. [Background technology]

[0003] The background discussion provided in this disclosure is intended to generally present the context of the disclosure. The work of the inventor(s) of the present application to the extent described in this Background section, and aspects of the description that may not otherwise be found to be prior art at the time of filing, are not admitted, expressly or impliedly, to be prior art to the present disclosure.

[0004] Valvular heart disease is a common cardiovascular condition that can consist of narrowing (i.e. stenosis), insufficiency (i.e. incompetence or regurgitation), or a combination of the two conditions affecting a patient's heart valves. When valvular heart disease develops, the chambers of the heart undergo adverse remodeling, leading to heart failure, severe illness, and reduced survival.

[0005] Open surgery is commonly used, but many patients are not surgical candidates due to the risks involved, and minimally invasive approaches to treatment are often preferred to minimize perioperative and postoperative recovery.

[0006] Transcatheter therapies for valvular heart disease include valve repair or total replacement, in which an artificial valve is implanted inside the patient's valve, or in which a prosthesis is implanted inside an existing prosthesis that has malfunctioned or been lost (e.g., valve-in-valve).

[0007] Transcatheter treatments for valvular heart disease typically preserve the native valve leaflets or artificial prostheses. Unfortunately, the native valve leaflets or artificial prostheses left in place can impede the success of subsequent repair or replacement. In some cases, the risk of obstruction is too high to allow a successful transcatheter treatment. In other cases, obstruction may not be noticed until the valve is implanted.

[0008] A specific example is transcatheter mitral valve replacement, in which a valve prosthesis is implanted into either the patient's native mitral valve apparatus or a previously placed artificial valve. Due to the proximity of the mitral annulus to the left ventricular outflow tract, transcatheter mitral valve replacement can result in the native or artificial leaflets being positioned in the direction of systolic flow. Anterior positioning of the native leaflets or artificial prosthesis can result in severe left ventricular outflow tract obstruction, which can be life-threatening. SUMMARY AND OBJECTS OF THE PRESENT DISCLOSURE

[0009] The following presents a simplified summary of one or more embodiments of the disclosure in order to provide a basic understanding of such embodiments. This summary is not an extensive overview of all contemplated embodiments and is not intended to identify key or critical elements of all embodiments or to delineate the scope of any or all embodiments.

[0010] The present disclosure provides a method for percutaneously modifying valve leaflets in the heart, thereby Change Repair or replaceThe present disclosure relates to systems and methods for facilitating the removal of a valve leaflet. In some embodiments, the leaflets are severed. In other embodiments, the leaflets are partially or completely removed. The disclosure is comprised of a steerable guide catheter (SGC) positioned within the ventricle, a delivery catheter (DC), a cutting element (CU), and a piercing member (P) having barbs or retaining elements (B). Although the disclosure describes methods for modifying the leaflets of the mitral valve, these same methods and tools can be used for any leaflet in the heart, either prior to subsequent valve treatment (i.e., repair or replacement) or as a stand-alone treatment.

[0011] While multiple embodiments are disclosed, still other embodiments of the present disclosure will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the invention. As will be appreciated, the various embodiments of the present disclosure are capable of modification in various obvious aspects, all without departing from the spirit and scope of the present disclosure. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive.

[0012] One aspect of the invention is a leaflet modification device comprising a steerable guide catheter, a piercing element extendable from a distal end of the steerable guide catheter and having a tissue engaging feature, and a cutting element extendable from the distal end of the steerable guide catheter and expandable from a first configuration to a second configuration, wherein the cutting element and the piercing element are translatable relative to one another to sandwich a leaflet between the cutting element and the piercing element and enable the cutting element to modify the leaflet.

[0013] Another aspect of the invention is a system for modifying a native valve leaflet, the system including a steerable guide catheter, a delivery catheter extendable from a distal end of the steerable guide catheter, and a cutting element extendable from the distal end of the steerable guide catheter and expandable from a first configuration to a second configuration, the cutting element having a cutting unit having a distal crossover, a push rod, and a connecting member connecting the cutting unit to the push rod.

[0014] Another aspect of the invention is a method of treating a valve leaflet, the method including advancing a cutting element through a catheter to a target leaflet, expanding the cutting element from a first configuration to a second configuration, engaging the leaflet with the cutting element, and modifying the leaflet with the cutting element. [Brief description of the drawings]

[0015] These and other aspects, features and advantages of which embodiments of the present invention are possible will become apparent and elucidated from the following description of embodiments of the invention that proceeds with reference to the accompanying drawings.

[0016] [Figure 1] FIG. 1 is a diagram of the human heart provided for reference.

[0017] [Diagram 2] FIG. 1 is a diagram of a human heart fitted with a prosthetic mitral valve, provided to illustrate the problem addressed by the present invention.

[0018] [Figure 3A] FIG. 1 is a perspective view of an unrepaired mitral valve provided for reference.

[0019] [Figure 3B] FIG. 1 is a perspective view of a mitral valve modified in accordance with an embodiment of the present invention.

[0020] [Figure 4A] FIG. 1 is a plan view of a mitral valve modified in accordance with one embodiment of the present invention.

[0021] [Figure 4B] FIG. 1 is a plan view of a mitral valve modified in accordance with one embodiment of the present invention.

[0022] [Figure 5A] 1A-1D illustrate steps of one embodiment of the leaflet modification method of the present invention.

[0023] [Figure 5B] 1A-1D illustrate steps of one embodiment of the leaflet modification method of the present invention.

[0024] [Figure 5C] 1A-1D illustrate steps of one embodiment of the leaflet modification method of the present invention.

[0025] [Figure 5D] 1A-1D illustrate steps of one embodiment of the leaflet modification method of the present invention.

[0026] [Figure 5E] 1A-1D illustrate steps of one embodiment of the leaflet modification method of the present invention.

[0027] [Figure 5F] 1A-1D illustrate steps of one embodiment of the leaflet modification method of the present invention.

[0028] [Figure 5G] 1A-1D illustrate steps of one embodiment of the leaflet modification method of the present invention.

[0029] [Figure 6A] FIG. 1 is a perspective view of a mitral valve modified in accordance with an embodiment of the present invention.

[0030] [Figure 6B] FIG. 1 is a perspective view of a mitral valve modified in accordance with an embodiment of the present invention.

[0031] [Figure 6C]FIG. 1 is a perspective view of a mitral valve modified in accordance with an embodiment of the present invention.

[0032] [Figure 6D] FIG. 1 is a perspective view of a mitral valve modified in accordance with an embodiment of the present invention.

[0033] [Figure 6E] FIG. 1 is a perspective view of a mitral valve modified in accordance with an embodiment of the present invention.

[0034] [Figure 6F] FIG. 1 is a perspective view of a mitral valve modified in accordance with an embodiment of the present invention.

[0035] [Figure 7A] 1A-1D illustrate steps of one embodiment of the leaflet modification method of the present invention.

[0036] [Figure 7B] 1A-1D illustrate steps of one embodiment of the leaflet modification method of the present invention.

[0037] [Figure 7C] 1A-1D illustrate steps of one embodiment of the leaflet modification method of the present invention.

[0038] [Figure 7D] 1A-1D illustrate steps of one embodiment of the leaflet modification method of the present invention.

[0039] [Figure 7E] 1A-1D illustrate steps of one embodiment of the leaflet modification method of the present invention.

[0040] [Figure 7F] 1A-1D illustrate steps of one embodiment of the leaflet modification method of the present invention.

[0041] [Figure 7G] 1A-1D illustrate steps of one embodiment of the leaflet modification method of the present invention.

[0042] [Figure 7H] 1A-1D illustrate steps of one embodiment of the leaflet modification method of the present invention.

[0043] [Figure 8] FIG. 1 is a plan view of a modified aortic valve modified according to one embodiment of the leaflet modification method of the present invention.

[0044] [Figure 9A] 1A-1D illustrate steps of one embodiment of the leaflet modification method of the present invention.

[0045] [Figure 9B] 1A-1D illustrate steps of one embodiment of the leaflet modification method of the present invention.

[0046] [Figure 10A] FIG. 1 is a plan view of a modified aortic valve modified according to one embodiment of the leaflet modification method of the present invention.

[0047] [Figure 10B] FIG. 1 is a plan view of a modified aortic valve modified according to one embodiment of the leaflet modification method of the present invention.

[0048] [Figure 10C] FIG. 1 is a plan view of a modified aortic valve modified according to one embodiment of the leaflet modification method of the present invention.

[0049] [Figure 10D] FIG. 1 is a plan view of a modified aortic valve modified according to one embodiment of the leaflet modification method of the present invention.

[0050] [Figure 10E] FIG. 1 is a plan view of a modified aortic valve modified according to one embodiment of the leaflet modification method of the present invention.

[0051] [Figure 11] FIG. 1 is a side view of one embodiment of a leaflet modification device of the present invention.

[0052] [Figure 12] FIG. 1 is a side view of one embodiment of a leaflet modification device of the present invention.

[0053] [Figure 13] FIG. 1 is a side view of one embodiment of a leaflet modification device of the present invention.

[0054] [Figure 14] FIG. 1 is a side view of one embodiment of a leaflet modification device of the present invention.

[0055] [Figure 15] FIG. 1 is a side view of one embodiment of a leaflet modification device of the present invention.

[0056] [Figure 16] FIG. 1 is a side view of one embodiment of a leaflet modification device of the present invention.

[0057] [Figure 17] FIG. 1 is a side view of one embodiment of a leaflet modification device of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0058] Next, specific embodiments of the present invention will be described with reference to the accompanying drawings. However, the present invention may be embodied in many different forms and should not be construed as being limited to the embodiments set forth in this disclosure. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present invention to those skilled in the art. The terms used in the detailed description of the embodiments shown in the accompanying drawings are not intended to limit the present invention. In the drawings, the same numbers refer to the same elements.

[0059] The present invention relates to the treatment of lesions of the aortic root and ascending aorta with devices deployed via a catheter. Although the present disclosure discusses embodiments of the present disclosure with respect to the aortic root and ascending aorta of a patient, the embodiments are applicable to any valve of the patient's heart and the present disclosure should not be construed as limited to this application. The embodiments described in this disclosure may be applied to the repair of other valves and chambers of the human heart.

[0060] When used in a patient, the device of the present invention modifies the leaflets to reduce the risk of left ventricular outflow tract ("LVOT") obstruction and facilitate subsequent valve repair or replacement. The device can be navigated to any portion of any valve leaflet and can cut or remove part or all of the targeted portion. From the operator's perspective, implantation of the device can be guided with real-time echocardiographic and fluoroscopic assessment. The cutting element can be of various shapes selected to suit the patient's anatomy and the desire to facilitate subsequent valvular disease treatment.

[0061] The heart is normally composed of four valves: the mitral valve, the aortic valve, the pulmonary valve, and the tricuspid valve. For purposes of explanation, this disclosure focuses on the use of the devices and methods of the present invention to modify the leaflets of the heart valves.

[0062] FIG. 1 illustrates various parts of the human heart, provided for reference and to establish some of the abbreviations used in this disclosure. The anterior mitral valve leaflet AML is part of the cardiac skeleton, located near the aortic valve AV and near the left ventricular outflow tract LVOT. When mitral valve closure occurs due to contractile pressure, the proximity of the AML to the LVOT increases during diastole and decreases during systole. Thus, systolic flow through the LVOT is normally unimpeded by the AML.

[0063] When mitral valve replacement is performed to replace the mitral valve with a prosthetic mitral valve PMV, as shown in Figure 2, the AML typically becomes externally fixed to the prosthetic valve frame. This fixation of the AML obstructs systolic flow through the LVOT, and such obstruction can be life-threatening. In many cases, mitral valve replacement, especially via transcatheter means, is not performed due to LVOT obstruction from AML fixation.

[0064] When performing open surgery on a patient, the surgeon may remove the AML to facilitate mitral valve repair. The present invention is directed to devices and methods that can be used to modify the AML and thereby reduce the risk of LVOT obstruction. The modification changes the AML from its baseline state (FIG. 3A) to a configuration (FIG. 3B) in which the anterior portion and its free end have an embodiment of a modification 10 that allows blood flow through the cells of a subsequently placed prosthetic valve. In one non-limiting example of an embodiment shown in FIG. 3B, the modification 10 is a cut only that maintains leaflet coaptation during systolic closure of the mitral valve. FIG. 4A is a plan view of the MV showing an example of the location of the modification 10 at the coaptation of the anterior mitral leaflet AML and the posterior mitral leaflet PML. In another embodiment, the modification is partial or complete removal of the leaflet (FIG. 4B), which would terminate the use of the native mitral valve in favor of implanting a prosthetic mitral valve.

[0065] 5A-5G, one embodiment of the device and method of the present invention is described. Beginning with FIG. 5A, a steerable guide catheter 20 is introduced into the left atrium and oriented such that the distal end 22 of the catheter 20 faces the anterior mitral valve leaflet AML. Those skilled in the art will appreciate that this method can be used to modify other anatomical valves and that this method is provided as a non-limiting example.

[0066] Next, a piercing element 30 is advanced from the distal end 22 of the steerable guide catheter 20, as seen in Figure 5B. The piercing element 30 includes tissue engaging features 32, such as barbs or similar retaining elements, that guide the AML to be secured both during systole (Figure 5C), when the AML and PML are brought together, and during diastole (Figure 5D), when the PML is directed away from the AML by the flow of blood from the left atrium LA to the left ventricle LV. The piercing element 30 may also include a hypotube (not shown) for placement of a guidewire through the AML.

[0067] 5E and 5F, once the AML is secured, a cutting element 40 is advanced through a delivery catheter 50, which is translatably housed within the steerable guide catheter 20, and engaged with the AML for modification. Methods of piercing that may be used include, for example, RF energy, mechanical force that causes the leaflets to close and impinge the needle tip, etc. Various embodiments of the cutting element 40 are described in more detail below.

[0068] Figures 6A-6F show various non-limiting examples of modifications that can be made to an AML (or other leaflet) according to the present invention. In Figure 6A, the modification 10 is embodied as a single slit 12. Figure 6B shows a double slit 13. Figure 6C shows an elongated slit 14. Figure 6D shows a crown-shaped slit 15. Figure 6E shows a cross-shaped slit 16. Figure 6F shows a wide slit 17 with tissue excision.

[0069] 7A-7H, an embodiment of a method of the present invention will be described in which a device of the present invention is used to modify an aortic valve AV. For reference, FIG. 7A shows the aortic valve AV, which connects the left ventricle LV and the ascending aorta Ao, in a closed state during diastole. FIG. 7B shows the aortic valve AV in an open state during systole, also for reference.

[0070] Beginning with Figure 7C, an embodiment of the method of the present invention begins by guiding a steerable guide catheter 20 through the ascending aorta to a location posterior to the aorta, directing it to the target valve cusp, and advancing a delivery catheter through the distal end 22 of the guide catheter 20. Figure 7C shows the delivery catheter 50 being advanced to the left aortic cusp during diastole, and Figure 7D shows the delivery catheter 50 maintaining its position during systole. The system of the present invention may be used to position the delivery catheter 50 in any one of the coronary cusps (i.e., the left coronary artery, the right coronary artery, or a non-coronary artery).

[0071] In FIG. 7E, the cutting element 40 is advanced from the delivery catheter such that the sharp distal intersection 42 penetrates and passes through the leaflet. To prevent buckling of the cutting element 40 and facilitate more precise placement, it may be advantageous to advance the delivery catheter 50 until it contacts the leaflet. In at least some embodiments, the cutting element 40 is an ablative electrical element and may be energized to pass through the leaflet. Other modes of cutting are known to those skilled in the art, including but not limited to mechanical cutting, cryoablation cutting, laser cutting, RF cutting, ultrasonic cutting, electrosurgical cutting, and the like. In other embodiments, an additional perforation wire may be advanced integrally with the cutting element 40 just distal to the cutting element 40 to pass the cutting element 40 through the leaflet. FIG. 7F shows the cutting element 40 passing through the leaflet and expanding into a deployed configuration to create the desired shape modification.

[0072] In Figure 7G, the cutting element 40, while energized if applicable, is retracted through the leaflets in the deployed configuration to begin forming the modification, and in Figure 7H, the cutting element 40 has passed through the leaflets and the modification has been formed.

[0073] Figure 8 shows a completed modification 10 made to an aortic valve cusp using the method of Figures 7A-7H. The modification 10 consists of a single slit 18 made in the middle of the cusp and spaced from the covering edge.

[0074] 9A-9B, additional steps of the method are shown that can be used to create additional modified shapes, if desired, using the same cutting element 40. In FIG. 9A, the steerable guide catheter 20 and delivery catheter 50 are repositioned by rotating, bending, or extending to a different position on the leaflet with the cutting element 40 retracted from the leaflet, and then advanced past the leaflet as described above or using the already created slit. The cutting element 40 is then retracted through the leaflet to create the additional modifications.

[0075] 10A-10F, non-limiting examples of modifications 10 made to an aortic valve using the methods described above are shown. FIG. 10A is a reference view of an unmodified aortic valve AV. FIG. 10B shows a modification 10 in the form of a slit 100 extending radially from the center of the leaflet to the middle of the leaflet. FIG. 10C shows a slit 101 formed in the center of the leaflet oriented generally parallel to the aortic valve periphery away from the edge. FIG. 10D shows a slit 102 formed from the edge of the leaflet and running generally parallel to the aortic valve periphery to a point within the leaflet. FIG. 10E shows a slit 103 extending from one free edge to another, effectively directing the ability to remove aortic valve leaflet tissue portion X.

[0076] With regard to the various embodiments of the cutting element 40 of the present invention, attention is first directed to FIG. 11 which illustrates that the cutting element 40 generally comprises a cutting unit 44 having a distal intersection 42, a push rod 46 used to advance the cutting element 40 through a delivery catheter 50, and a connecting element 48 connecting the cutting unit 44 to the push rod 46.

[0077] The cutting unit 44 is generally a looped wire having a first configuration and a second deployed configuration. The second configuration is heat set into the wire upon release from the delivery catheter in at least one embodiment. In at least one embodiment, the wire is formed from a memory metal such as Nitinol. In one embodiment, the cutting unit 44 is self-expanding with a shape that allows engagement of the leaflets from one or both sides of the valve. In another embodiment, the cutting unit 44 has exposed elements for charging and severing the leaflets. In yet another embodiment, the cutting unit 44 has a sharp tip for mechanically cutting the leaflets. In yet another embodiment, the cutting unit 44 passes through the leaflets and then expands or charges them to facilitate modification.

[0078] The cutting unit 44 can be modified into various shapes to suit the anatomy of the heart valve and the planned subsequent treatment. Figures 12-15 are embodiments of the cutting element 40 that differ only in the shape of the cutting unit 44. Figure 12 shows the cutting unit 44 in a second enlarged configuration with oblong wings 60, 61 formed. Figure 13 shows the cutting unit 44 in a second enlarged configuration with oblong wings 62, 63 formed. Figure 14 shows the cutting unit 44 in a second enlarged configuration with swept back wings 64, 65 formed. Figure 15 shows the cutting unit 44 in a second enlarged configuration with elongated swept back wings 66, 67 formed.

[0079] 16 and 17 illustrate an embodiment of a cutting element 70 that utilizes a tether 72 to manually change the configuration of the cutting unit 44 from a first configuration to a second configuration. The cutting element 70, like the other embodiments, includes a cutting unit 44 having a distal crossover 42, a push rod 46 that is used to advance the cutting element 40 through the delivery catheter 50, and a linking element 48 that connects the cutting unit 44 to the push rod 46. The tether 72 leads from the proximal end of the catheter and has a mechanism attached thereto that allows a user to pull on the tether. A distal end 74 of the tether 72 is attached to the distal crossover 42 of the cutting unit 44. Pulling the tether 72 retracts the distal crossover 42, causing the cutting unit 44 to assume the second configuration, as seen in FIG.

[0080] As used in this disclosure, the term "substantially" or "generally" refers to the complete or nearly complete extent or degree of an action, property, quality, state, structure, item, or result. For example, an object that is "substantially" or "generally" enclosed means that the object is either completely enclosed or nearly completely enclosed. The exact extent to which deviations from absolute completeness are permitted may depend on the particular context in some cases. Generally, however, the proximity to completeness will be a degree of completeness that results in a similar overall result as would be obtained if absolute and complete completion were obtained. The terms "substantially" or "generally" are equally applicable when used in a negative sense, implying a complete or nearly complete absence of an action, property, quality, state, structure, item, result, etc. For example, an element, combination, embodiment, or composition that is "substantially free" or "generally free" of a component or element may still actually include the item, generally to the extent that there is no measurable effect of the item.

[0081] Any reference to "one embodiment" or "an embodiment" as used in this disclosure means that a particular element, feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment. Appearances of the phrase "in one embodiment" in various places in this specification are not necessarily all referring to the same embodiment.

[0082] As used herein, the terms "comprise," "comprising," "includes," "has," "having," or other variations are intended to cover a non-exclusive inclusion. For example, a process, method, article, or apparatus consisting of a list of elements is not necessarily limited to only those elements, but may include other elements not expressly listed or inherent to the process, method, article, or apparatus. Also, unless expressly stated otherwise, "or" means an inclusive "or" and not an exclusive "or." For example, a condition A or B is satisfied if: A is true (or present) and B is false (or absent), A is false (or absent) and B is true (or present), or both A and B are true (or present).

[0083] In addition, the use of "a" or "an" is employed to describe elements and components of the embodiments of the present disclosure. This is done merely for convenience and to give a general sense of the description. This specification should be read to include one or at least one, unless otherwise clear, and the singular also includes the plural.

[0084] Although the present invention has been described in terms of specific embodiments and applications, those skilled in the art can, in light of this teaching, create additional embodiments and modifications without departing from the spirit of the claimed invention or beyond the scope of the claimed invention. It is therefore understood that the drawings and specification in this disclosure are presented by way of example to facilitate understanding of the invention and should not be construed as limiting its scope.

Claims

1. 1. A system for modifying a native valve leaflet, comprising: a steerable guide catheter; a cutting element extendable from a distal end of the steerable guide catheter, the cutting element comprising an electrical loop wire; 1) a first configuration, in which a distal crossing is configured to pierce the leaflet via RF energy to allow a cutting unit to pass through the leaflet; 2) the cutting unit having an expanded second configuration, in which the looped wire of the cutting unit forms an elliptical, rectangular, or oblong wing shape and is configured to cut a slit in the valve leaflet via RF energy; Push stick and a connecting member connecting the cutting unit to the push bar.

2. The system of claim 1 , wherein the airfoil shape is swept back.

3. The system of claim 1 , wherein the expanded second configuration is configured to sever the leaflets upon retraction.

4. 10. The system of claim 1, wherein the electrical looped wire comprises a shape memory metal and is heat set into the expanded second configuration.

5. The system of claim 1 , further comprising a tether configured to change the configuration of the cutting unit between the first configuration and the expanded second configuration.

6. The system described in claim 5, wherein the tether is attached to the distal intersection.

7. The system of claim 1 , wherein the second expanded configuration is further configured to sever the leaflets upon retraction.

8. The system of claim 1 , wherein the cutting unit has exposed elements for charging and cutting the leaflets.

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