Tissue modification apparatus

Abstract

The present disclosure relates to a tissue modification apparatus (200). In an example, the tissue perforation apparatus comprises a needle (212) and a dilation assembly extending through the needle. The needle has a needle head (216) terminating at a needle tip. The dilation assembly includes an expansion member (260) movable between compacted and expanded states. The needle and the dilation assembly are axially movable relative to each other. In some examples, the expansion member is an inflatable hole-dilating balloon. In some examples, the apparatus can further include a protective shaft (232) disposed between the needle and the dilation assembly.

Description

TISSUE MODIFICATION APPARATUSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 568,154, filed March 21, 2024, which is incorporated by reference herein.FIELD

[0002] The present disclosure relates to devices and apparatuses configured to modify a target tissue, which can be a leaflet of an existing valvular structure.BACKGROUND

[0003] The human heart can suffer from various valvular diseases. These valvular diseases can result in significant malfunctioning of the heart and ultimately require repair of the native valve or replacement of the native valve with an artificial valve. There are a number of known repair devices (for example, stents) and artificial valves, as well as a number of known methods of implanting these devices and valves in humans. Percutaneous and minimally-invasive surgical approaches, such as transcatheter aortic valve replacement (TAVR), are used in various procedures to deliver prosthetic medical devices to locations inside the body that are not readily accessible by surgery or where access without surgery is desirable.

[0004] Transcatheter aortic valve replacement (TAVR) is one example of a minimally-invasive surgical procedure used to replace a native aortic valve. In one specific example of the procedure, an expandable prosthetic heart valve is mounted in a crimped state on the distal end of a delivery apparatus and advanced through the patient's vasculature (for example, through a femoral artery and the aorta) to the heart. The prosthetic heart valve is positioned within the native valve and expanded to its functional size.

[0005] A variant of TAVR is valve-in- valve (ViV) TAVR, where a new prosthetic heart valve replaces a previously implanted prosthetic valve. In one specific example of the procedure, a new expandable prosthetic heart valve (“guest valve”) is delivered to the heart in a crimped state, as described above for the “native” TAVR. The guest valve is positioned within the previously implanted prosthetic valve (“host valve”) and then expanded to its functional size. The host valve in a ViV TAVR procedure can be a surgically implanted prosthetic valve or a transcatheter prosthetic valve. The term “host valve” is also used herein to refer to the native aortic valve in a native TAVR procedure.SUMMARY

[0006] One known technique for mitigating the risk of coronary ostial obstruction involves lacerating or severing a portion of one or more leaflets of the host valve (which can be an aortic bioprosthetic valve or a native aortic valve). Lacerating or severing a portion of the leaflet(s) reduces the risk of blocking the coronary ostia when the guest prosthetic valve is implanted and displaces the leaflets of the host valve toward the inner wall of the aortic root. However, method that rely on lacerating existing leaflets, require high spatial precision and surgical skill. Moreover, once the leaflets have been lacerated, the existing heart valve may function poorly and increase the risk of aortic insufficiency, at least until a replacement prosthetic valve has been successfully implanted. If the existing leaflets have become calcified, there is a further risk that the lacerating will release particulate or other debris into the blood stream, which may make the patient susceptible to vascular occlusion or stroke.

[0007] In one of its basic configurations, a tissue modification apparatus comprises a needle and a dilation assembly extending through the needle. This basic configuration can preferably be provided with any one or more of the features described elsewhere herein, in particular with those of the examples described hereafter. However, it should be understood that the basic configuration can preferably also be provided with any one or more of the features shown in the figures and / or described in conjunction with the figures, either in addition to or alternatively to the features of the examples described hereafter.

[0008] In some examples, the needle can comprise a needle head optionally terminating at a needle tip.

[0009] In some examples, the dilation assembly can comprise an expansion member optionally movable between a compacted state and an expanded state.

[0010] In some examples, the needle and the dilation assembly can optionally be axially movable relative to each other.

[0011] In some examples, the apparatus can comprise a protective shaft disposed between the needle and the dilation assembly.

[0012] In some examples, the expansion member can optionally be a hole-dilating balloon optionally mounted on a balloon catheter of the dilation assembly, wherein the compacted state of the expansion member can optionally be a deflated state of the hole-dilating balloon, and wherein the expanded state of the expansion member can optionally be an inflated state of the hole-dilating balloon.

[0013] In some examples, the dilation assembly can comprise a dilator attached to a dilator shaft extending proximally therefrom.

[0014] In some examples, the needle head can comprise a plurality of head slits.

[0015] In some examples, the needle can optionally be configured to form a pilot puncture in a target tissue.

[0016] In some examples, the expansion member can optionally be configured to be inserted within the pilot puncture.

[0017] In some examples, moving the expansion member to the expanded state, when positioned within the pilot puncture, can optionally be configured to expand the pilot puncture to form a tissue opening.

[0018] In some examples, the target tissue can optionally be a host leaflet of a host valvular structure, and wherein the tissue opening can be a leaflet opening.

[0019] In one of its basic methods, a method comprises advancing a tissue modification apparatus to a target tissue. This basic method can preferably be provided with any one or more of the steps described elsewhere herein, in particular with those of the examples described hereafter. However, it should be understood that the basic method can preferably also be provided with any one or more of the steps shown in the figures and / or described in conjunction with the figures, either in addition to or alternatively to the steps of the examples described hereafter.

[0020] In some examples, the advancing the tissue modification apparatus can optionally be over a guidewire.

[0021] In some examples, the tissue modification apparatus optionally comprises a needle.

[0022] In some examples, the tissue modification apparatus optionally comprises a dilation assembly.

[0023] In some examples, the dilation assembly can optionally extend through the needle.

[0024] In some examples, the method comprises forming a pilot puncture through the target tissue.

[0025] In some examples, the forming the pilot puncture optionally comprises advancing a needle head of the needle against the target tissue.

[0026] In some examples, the forming the pilot puncture optionally by advancing the needle head optionally comprises maintaining an expansion member of the dilation assembly in a compacted state of the expansion member, proximal to the needle head.

[0027] In some examples, the method optionally comprises, after the forming the pilot puncture, positioning the expansion member, in its compacted state, inside the pilot puncture.

[0028] In some examples, the dilation assembly optionally comprises a dilator distal to the expansion member, and a dilator shaft optionally attached to the dilator and extending proximally therefrom.

[0029] In some examples, the positioning the expansion member inside the pilot puncture optionally comprises passing the dilator through the pilot puncture.

[0030] In some examples, the method optionally comprises, after the positioning the expansion member inside the pilot puncture, expanding the expansion member inside the pilot puncture to dilate the pilot puncture and optionally form a tissue opening within the target tissue.

[0031] In some examples, the expansion member can optionally be a hole-dilating balloon mounted on a balloon catheter of the dilation assembly, wherein the compacted state can optionally be a deflated state of the hole-dilating balloon, and wherein the expanding the expansion member optionally comprises inflating the hole-dilating balloon.

[0032] In some examples, the tissue modification apparatus optionally comprises a protective shaft disposed between the needle and the dilation assembly.

[0033] In some examples, the method optionally comprises, before the positioning the holedilating balloon inside the pilot puncture, advancing the protective shaft towards the target tissue.

[0034] In some examples, the advancing the protective shaft towards the target tissue optionally comprises passing the protective shaft through the pilot puncture.

[0035] In some examples, the method optionally comprises, before the inflating the holedilating balloon, retracting the needle from the target tissue.

[0036] In some examples, the method optionally comprises, after the retracting the needle and before the inflating the hole-dilating balloon, retracting the protective shaft.

[0037] In some examples, the method optionally comprises, after the inflating the hole-dilating balloon, deflating the hole-dilating balloon.

[0038] In some examples, the method optionally comprises, after the deflating the hole-dilating balloon, retracting the hole-dilating balloon from the target tissue.

[0039] In some examples, the target tissue can optionally be a host leaflet of a host valvular structure, and wherein the tissue opening can be a leaflet opening.

[0040] In some examples, the method optionally comprises, after the retracting the expansion member, positioning a guest prosthetic valve in a radially compressed state thereof within the host valvular structure, and optionally radially expanding the guest prosthetic valve.

[0041] In some examples, the radially expanding the guest prosthetic valve optionally comprises inflating a valve-expanding balloon over which the guest prosthetic valve can be disposed.

[0042] The aspects of this disclosure can be used in combination or separately. This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. The foregoing and other objects, features, and advantages of the invention will become more apparent from the following detailed description, which proceeds with reference to the accompanying figures.BRIEF DESCRIPTION OF THE FIGURES

[0043] Some examples of the invention are described herein with reference to the accompanying figures. The description, together with the figures, makes apparent to a person having ordinary skill in the art how some examples may be practiced. The figures are for the purpose of illustrative description and no attempt is made to show structural details of an example in more detail than is necessary for a fundamental understanding of the invention. For the sake of clarity, some objects depicted in the figures are not to scale.In the Figures:

[0044] Fig. 1 is a sectional view of an aortic root.

[0045] Fig. 2A shows a cross-sectional view of a prosthetic heart valve implanted in the native aortic valve of within the aortic root of Fig. 1, according to an example.

[0046] Fig. 2B shows the implanted prosthetic heart valve of Fig. 1A as viewed from the ascending aorta, according to an example.

[0047] Fig. 3 shows a valve-in- valve implantation within the native aortic valve of Fig. 1, according to an example.

[0048] Fig. 4 is a perspective view of an exemplary tissue modification apparatus.

[0049] Fig. 5A is a perspective sectional view of a distal portion of an exemplary tissue modification apparatus, with a distal portion of a dilation assembly positioned proximal to a needle head of the apparatus.

[0050] Fig. 5B is a perspective sectional view of a distal portion of the apparatus of Fig. 5A, with the distal portion of the dilation assembly extending distal to the needle head.

[0051] Fig. 5C is a cross-sectional side view of the tissue modification apparatus of Fig. 5B.

[0052] Figs. 6A-6H illustrate steps in a method for utilizing a tissue modification assembly for forming a leaflet opening within a host leaflet.

[0053] Figs. 61-6 J illustrate steps in a method for positioning and expanding a guest prosthetic valve inside the leaflet opening.

[0054] Fig. 7A shows the hole-dilating balloon positioned within a pilot puncture of the host leaflet in a deflated state.

[0055] Fig. 7B shows the hole-dilating balloon of Fig. 7A inflated within a pilot puncture of the host leaflet.

[0056] Fig. 7C shows the guest prosthetic valve positioned within the leaflet opening after removal of the hole-dilating balloon of Fig. 7B.

[0057] Fig. 8A is a perspective view of a host prosthetic valve subsequent to forming a leaflet opening thereof.

[0058] Fig. 8B is a perspective view of a guest prosthetic valve expanded within a leaflet opening of a host prosthetic valve.

[0059] Fig. 9A is a perspective view of a distal portion of an exemplary tissue modification apparatus comprising a steerable tube assembly disposed around the needle.

[0060] Fig. 9B is a perspective view of the steerable tube assembly of Fig. 9A, with an outer bendable tube of the steerable tube assembly removed from view for illustrative purpose.

[0061] Figs. 10A and 10B are cross-sectional side views of a distal portion of the apparatus of Fig. 9A in unbent and bent states, respectively, of the steerable tube assembly.DETAILED DESCRIPTION

[0062] For purposes of this description, certain aspects, advantages, and novel features of the examples of this disclosure are described herein. The disclosed methods, apparatus, and systems should not be construed as being limiting in any way. Instead, the present disclosure is directed toward all novel and nonobvious features and aspects of the various disclosed examples, alone and in various combinations and sub-combinations with one another. The methods, apparatus, and systems are not limited to any specific aspect or feature or combination thereof, nor do the disclosed examples require that any one or more specific advantages be present, or problems be solved. The technologies from any example can be combined with the technologies described in any one or more of the other examples. In view of the many possible examples to which the principles of the disclosed technology may be applied, it should be recognized that the illustrated examples are only preferred examples and should not be taken as limiting the scope of the disclosed technology.

[0063] Although the operations of some of the disclosed examples are described in a particular, sequential order for convenient presentation, it should be understood that this manner of description encompasses rearrangement, unless a particular ordering is required by specific language set forth below. For example, operations described sequentially may in some cases be rearranged or performed concurrently. Moreover, for the sake of simplicity, the attached figures may not show the various ways in which the disclosed methods can be used in conjunction with other methods. Additionally, the description sometimes uses terms like “provide” or “achieve” to describe the disclosed methods. These terms are high-level abstractions of the actual operations that are performed. The actual operations that correspond to these terms may vary depending on the particular implementation and are readily discernible by one of ordinary skill in the art.

[0064] All features described herein are independent of one another and, except where structurally impossible, can be used in combination with any other feature described herein.

[0065] As used in this application and in the claims, the singular forms “a”, “an”, and “the” include the plural forms unless the context clearly dictates otherwise. Additionally, the terms “have” or “includes” means “comprises”. Further, the terms “coupled”, “connected”, and “attached”, as used herein, are interchangeable and generally mean physically, mechanically, chemically, magnetically, and / or electrically coupled or linked and does not exclude the presence of intermediate elements between the coupled or associated items absent specific contrary language. As used herein, “and / or” means “and” or “or”, as well as “and” and “or”.

[0066] Directions and other relative references may be used to facilitate discussion of the drawings and principles herein, but are not intended to be limiting. For example, certain terms may be used such as “inner”, “outer”, “upper”, “lower”, “inside”, “outside”, “top”, “bottom”, “interior”, “exterior”, “left”, right”, and the like. Such terms are used, where applicable, to provide some clarity of description when dealing with relative relationships, particularly with respect to the illustrated examples. Such terms are not, however, intended to imply absolute relationships, positions, and / or orientations. For example, with respect to an object, an “upper” part can become a “lower” part simply by turning the object over. Nevertheless, it is still the same part and the object remains the same.

[0067] The term “plurality” or “plural” when used together with an element means two or more of the element. Directions and other relative references (for example, inner and outer, upper and lower, above and below, left and right, and proximal and distal) may be used to facilitate discussion of the drawings and principles herein but are not intended to be limiting.

[0068] The terms “proximal” and “distal” are defined relative to the use position of a delivery apparatus. In general, the end of the delivery apparatus closest to the user of the apparatus is the proximal end, and the end of the delivery apparatus farthest from the user (for example, the end that is inserted into a patient's body) is the distal end. The term “proximal” when used with two spatially separated positions or parts of an object can be understood to mean closer to or oriented towards the proximal end of the delivery apparatus. The term “distal” when used with two spatially separated positions or parts of an object can be understood to mean closer to or oriented towards the distal end of the delivery apparatus. The terms “longitudinal” and “axial” are interchangeable, and refer to an axis extending in the proximal and distal directions, unless otherwise expressly defined.

[0069] The terms “axial direction”, “radial direction”, and “circumferential direction” have been used herein to describe the arrangement and assembly of components relative to the geometry of the frame of the prosthetic valve, or the geometry of an inflatable balloon that can be used to expand a prosthetic valve. Such terms have been used for convenient description, but the disclosed examples are not strictly limited to the description. In particular, where a component or action is described relative to a particular direction, directions parallel to the specified direction as well as minor deviations therefrom are included. Thus, a description of a component extending along an axial direction of the frame does not require the component to be aligned with a center of the frame; rather, the component can extend substantially along a direction parallel to a central axis of the frame.

[0070] As used herein, the terms “integrally formed” and “unitary” refer to a construction that does not include any welds, fasteners, or other means for securing separately formed pieces of material to each other.

[0071] As used herein, operations that occur “simultaneously” or “concurrently” occur generally at the same time as one another, although delays in the occurrence of operation relative to the other due to, for example, spacing between components, are expressly within the scope of the above terms, absent specific contrary language.

[0072] As used herein, terms such as “first”, “second”, and the like are intended to serve as respective labels of distinct components, steps, etc. and are not intended to connote or imply a specific sequence or priority. For example, unless otherwise stated, a step of performing a second action and / or of forming a second component may be performed prior to a step of performing a first action and / or of forming a first component.

[0073] As used herein, the term “substantially” means the listed value and / or property and any value and / or property that is at least 75% of the listed value and / or property. Equivalently, theterm “substantially” means the listed value and / or property and any value and / or property that differs from the listed value and / or property by at most 25%. For example, “at least substantially parallel” refers to directions that are fully parallel, and to directions that diverge by up to 22.5 degrees.

[0074] In the present disclosure, a reference numeral that includes an alphabetic label (for example, “a”, “b”, “c”, etc.) is to be understood as labeling a particular example of the structure or component corresponding to the reference numeral. Accordingly, it is to be understood that components sharing like names and / or like reference numerals (for example, with different alphabetic labels or without alphabetic labels) may share any properties and / or characteristics as disclosed herein even when certain such components are not specifically described and / or addressed herein.

[0075] Throughout the figures of the drawings, different superscripts for the same reference numerals are used to denote different examples of the same elements. Examples of the disclosed devices and systems may include any combination of different examples of the same elements. Specifically, any reference to an element without a superscript may refer to any alternative example of the same element denoted with a superscript. In order to avoid undue clutter from having too many reference numbers and lead lines on a particular drawing, some components will be introduced via one or more drawings and not explicitly identified in every subsequent drawing that contains that component.

[0076] Described herein are devices and methods for puncturing a tissue, such as a leaflet, which can be performed as part of a procedure for implanting prosthetic valves and modifying leaflets of an existing valvular structure in a patient's heart. Prior to or during implantation of the prosthetic heart valve within the existing valvular structure, a tissue piercing assembly that includes a needle can be provided in the ascending aorta of a patient and can be used to pierce, lacerate, slice, tear, cut or otherwise modify a leaflet or commissure of the existing valvular structure. In some examples, the existing valvular structure can be a native aortic valve (for example, normal or abnormal, such as bicuspid aortic valve (BAV)) or a prosthetic valve previously implanted in the native aortic valve. The modification can avoid, or at least reduce the likelihood of, issues that leaflets of the existing valvular structure might otherwise cause once the prosthetic heart valve has been fully installed, for example, obstruction of blood flow to the coronary arteries, improper mounting due to a non-circular valve cross-section, and / or restricted access to the coronary arteries if subsequent intervention is required. While described with respect to aortic valve, it should be understood that the disclosed examples can be adapted to deliver devices that can modify existing valvular structure, and in some implementations,implant prosthetic devices, to and / or in any of the native annuluses of the heart (for example, the aortic, pulmonary, mitral, and tricuspid annuluses), and can be used with any of various delivery approaches (for example, retrograde, antegrade, transseptal, transventricular, transatrial, etc.).

[0077] Fig. 1 illustrates an anatomy of the aortic root 22, which is positioned between the left ventricle 32 and the ascending aorta 26. The aortic root 22 includes a native aortic valve 20 having a native valvular structure 29 comprising a plurality of native leaflets 30. Normally, the native aortic valve 20 has three leaflets (only two leaflets are visible in the simplified illustration of Fig. 1), but aortic valves with fewer than three leaflets are possible. The leaflets 30 are supported at native commissures by the aortic annulus 24, which is a ring of fibrous tissue at the transition point between the left ventricle 32 and the aortic root 22. The leaflets 30 can cycle between open and closed positions (the closed position is shown in Fig. 1) to regulate flow of blood from the left ventricle 32 to the ascending aorta 26. Branching off the aortic root 22 are the coronary arteries 34, 36. The coronary artery ostia 42, 44 are the openings that connect the aortic root 22 to the coronary arteries 34, 36.

[0078] Figs. 2A-2B show an exemplary prosthetic valve 100 that can be implanted in a native heart valve, such as the native aortic valve 20 of Fig. 1. The term “prosthetic valve”, as used herein, refers to any type of a prosthetic valve deliverable to a patient's target site over a catheter, which is radially expandable and compressible between a radially compressed, or crimped, state, and a radially expanded state. Thus, the prosthetic valve can be crimped on or retained by an implant delivery apparatus (not shown) in the radially compressed state during delivery, and then expanded to the radially expanded state once the prosthetic valve reaches the implantation site. The expanded state may include a range of diameters to which the valve may expand, between the compressed state and a maximal diameter reached at a fully expanded state. Thus, a plurality of partially expanded states may relate to any expansion diameter between radially compressed or crimped state, and maximally expanded state. A prosthetic valve of the current disclosure (for example, prosthetic valve 100) may include any prosthetic valve configured to be mounted within the native aortic valve, the native mitral valve, the native pulmonary valve, and the native tricuspid valve.

[0079] It is understood that the prosthetic valves disclosed herein may be used with a variety of implant delivery apparatuses. Balloon expandable valves generally involve a procedure of inflating a balloon within a prosthetic valve, thereby expanding the prosthetic valve within the desired implantation site. Once the valve is sufficiently expanded, the balloon is deflated and retrieved along with a delivery apparatus (not shown). Self-expandable valves include a framethat is shape-set to automatically expand as soon an outer retaining shaft or capsule (not shown) is withdrawn proximally relative to the prosthetic valve. Mechanically expandable valves are a category of prosthetic valves that rely on a mechanical actuation mechanism for expansion. The mechanical actuation mechanism usually includes a plurality of expansion and locking assemblies (such as the prosthetic valves described in U.S. Patent No. 10,603,165, International Application No. PCT / US2021 / 052745 and U.S. Provisional Application Nos. 63 / 085,947 and 63 / 209904, each of which is incorporated herein by reference in its entirety), releasably coupled to respective actuation assemblies of a delivery apparatus, controlled via a handle (not shown) for actuating the expansion and locking assemblies to expand the prosthetic valve to a desired diameter. The expansion and locking assemblies may optionally lock the valve's diameter to prevent undesired recompression thereof, and disconnection of the actuation assemblies from the expansion and locking assemblies, to enable retrieval of the delivery apparatus once the prosthetic valve is properly positioned at the desired site of implantation.

[0080] Figs. 2A-2B show an example of a prosthetic valve 100, which can be a balloon expandable valve or any other type of valve, illustrated in an expanded state. The prosthetic valve 100 can comprise an outflow end 106 and an inflow end 104. In some instances, the outflow end 106 is the proximal end of the prosthetic valve 100, and the inflow end 104 is the distal end of the prosthetic valve 100. Alternatively, depending for example on the delivery approach of the valve, the outflow end can be the distal end of the prosthetic valve, and the inflow end can be the proximal end of the prosthetic valve.

[0081] The term “outflow”, as used herein, refers to a region of the prosthetic valve through which the blood flows through and out of the prosthetic valve 100.

[0082] The term “inflow”, as used herein, refers to a region of the prosthetic valve through which the blood flows into the prosthetic valve 100.

[0083] In the context of the present application, the terms “lower” and “upper” are used interchangeably with the terms “inflow” and “outflow”, respectively. Thus, for example, the lower end of the prosthetic valve is its inflow end and the upper end of the prosthetic valve is its outflow end.

[0084] In the context of the present application, the terms “lower” and “upper” are used interchangeably with the terms “distal to” and “proximal to”, respectively. Thus, for example, a lowermost component can refer to a distal-most component, and an uppermost component can similarly refer to a proximal-most component.

[0085] The terms “longitudinal” and “axial”, as used herein, refer to an axis extending in the proximal and distal directions, unless otherwise expressly defined.

[0086] The prosthetic valve 100 comprises an annular frame 102 movable between a radially compressed configuration and a radially expanded configuration, and a valvular structure 113 that comprises prosthetic valve leaflets 114 mounted within the frame 102. The frame 102 can be made of various suitable materials, including plastically-deformable materials such as, but not limited to, stainless steel, a nickel-based alloy (for example, a nickel-cobalt-chromium alloy such as MP35N alloy), polymers, or combinations thereof. When constructed of a plastically- deformable materials, the frame 102 can be crimped to a radially compressed state on a balloon catheter, and then expanded inside a patient by an inflatable balloon or equivalent expansion mechanism. Alternatively or additionally, the frame 102 can be made of shape-memory materials such as, but not limited to, nickel-titanium alloy (for example, Nitinol). When constructed of a shape-memory material, the frame 102 can be crimped to a radially compressed state and restrained in the compressed state by insertion into a shaft or equivalent mechanism of a delivery apparatus.

[0087] In the example illustrated in Figs. 2A-2B, the frame 102 is an annular, stent- like structure comprising a plurality of intersecting struts 108. In this application, the term “strut” encompasses axial struts, angled struts, laterally extendable struts, commissure windows, commissure support struts, support posts, and any similar structures described by U.S. Pat. Nos. 7,993,394 and 9,393,110, which are incorporated herein by reference. A strut 108 may be any elongated member or portion of the frame 102. The frame 102 can include a plurality of strut rungs that can collectively define one or more rows of cells 110. The frame 102 can have a cylindrical or substantially cylindrical shape having a constant diameter from the inflow end 104 to the outflow end 106 as shown, or the frame can vary in diameter along the height of the frame, as disclosed in US Pat. No. 9,155,619, which is incorporated herein by reference.

[0088] The struts 108 can include a plurality of angled struts and vertical or axial struts. At least some of the struts 108 can be pivotable or bendable relative to each other, so as to permit frame expansion or compression. For example, the frame 102 can be formed from a single piece of material, such as a metal tube, via various processes such as, but not limited to, laser cutting, electroforming, and / or physical vapor deposition, while retaining the ability to collapse / expand radially in the absence of hinges and like.

[0089] A valvular structure 113 of the prosthetic valve 100 can include a plurality of prosthetic valve leaflets 114 (for example, three leaflets), positioned at least partially within the frame 102, and configured to regulate flow of blood through the prosthetic valve 100 from the inflow end 104 to the outflow end 106. While three leaflets 114 arranged to collapse in a tricuspid arrangement, are shown in the example illustrated in Figs. 2A-2B, it will be clear that aprosthetic valve 100 can include any other number of leaflets 114. Adjacent leaflets 114 can be arranged together to form prosthetic valve commissures 116 that are coupled (directly or indirectly) to respective portions of the frame 102, thereby securing at least a portion of the valvular structure 113 to the frame 102. The prosthetic valve leaflets 114 can be made from, in whole or part, biological material (for example, pericardium), bio-compatible synthetic materials, or other such materials. Further details regarding transcatheter prosthetic valves, including the manner in which leaflets 114 can be coupled to the frame 102 of the prosthetic valve 100, can be found, for example, in U.S. Patent Nos. 6,730,118, 7,393,360, 7,510,575, 7,993,394, 8,652,202, and 11,135,056, all of which are incorporated herein by reference in their entireties.

[0090] In some examples, the prosthetic valve 100 can comprise at least one skirt or sealing member. For example, the prosthetic valve 100 can include an inner skirt (not shown in Fig. 2A-2B), which can be secured to the inner surface of the frame 102. Such an inner skirt can be configured to function, for example, as a sealing member to prevent or decrease perivalvular leakage. An inner skirt can further function as an anchoring region for leaflets 114 to the frame 102, and / or function to protect the leaflets 114 against damage which may be caused by contact with the frame 102, for example during valve crimping or during working cycles of the prosthetic valve 100. An inner skirt can be disposed around and attached to the inner surface of frame 102, while the leaflets can be sutured to the inner skirt along a scalloped line (not shown). An inner skirt can be coupled to the frame 102 via sutures or another form of coupler.

[0091] The prosthetic valve 100 can comprise, in some examples, an outer skirt 118 mounted on the outer surface of frame 102 (as shown in Figs. 2A-2B), configured to function, for example, as a sealing member retained between the frame 102 and the surrounding tissue of the native annulus against which the prosthetic valve is mounted, or against an inner side of a previously implanted valve in the case of ViV procedures (described further below), thereby reducing risk of paravalvular leakage (PVL) past the prosthetic valve 100. The outer skirt 118 can be coupled to the frame 102 via sutures or another form of coupler.

[0092] Any of the inner skirt and / or outer skirt can be made of various suitable biocompatible materials, such as, but not limited to, various synthetic materials (for example, PET) or natural tissue (for example pericardial tissue). In some cases, the inner skirt can be formed of a single sheet of material that extends continuously around the inner surface of frame 102. In some cases, the outer skirt 118 can be formed of a single sheet of material that extends continuously around the outer surface of frame 102.

[0093] The cells 110, defined by interconnected struts 108, define cell openings 112. While some of the cell openings 112 can be covered by the inner skirt and / or the outer skirt, at least a portion of the cell opening 112 can remain uncovered, such as cell openings 112 which are closer to the outflow end 106 of the prosthetic valve.

[0094] Figs. 2A-2B illustrate a hypothetical coronary artery obstruction that could occur in some cases from implantation of a prosthetic valve 100 within the native aortic valve 20. In this example, the prosthetic valve 100 is the guest valve or new valve, and the native aortic valve 20 is the host valve or old valve.

[0095] During implantation of the prosthetic valve 100, the prosthetic valve 100 is positioned within a central region defined between the native leaflets 30, which are also the host leaflets 10 for the example illustrated in Fig. 2A-2B. The prosthetic valve 100 is then radially expanded against the host leaflets 10. As illustrated, the host leaflets 10 form a tube around the frame 102 of the prosthetic valve 100 after the prosthetic valve 100 is radially expanded to the working diameter. As further illustrated, expansion of the prosthetic valve 100 displaces the host leaflets 10 outwards towards the coronary ostia 42, 44 such that the host leaflets 10 contact a portion of the aortic root 22 surrounding the coronary ostia 42, 44, causing coronary artery obstruction.

[0096] For an existing implanted prosthetic valve, the valvular structure may naturally degrade over time thereby requiring repair or replacement in order to maintain adequate heart functions. In a Valve- in- Valve (ViV) procedure, a new prosthetic heart valve is mounted within the existing, degrading prosthetic heart valve in order to restore proper function. Fig. 3 illustrates an exemplary hypothetical coronary artery obstruction that could occur in some cases from implantation of a prosthetic valve 100b within a previously implanted prosthetic valve 100a (for example, after a ViV procedure). In this example, the prosthetic valve 100b is the guest valve or new valve, and the prosthetic valve 100a is the host valve or old valve. In this example, the prosthetic valve 100a was previously implanted within the orifice of the native aortic valve 20. Each of the prosthetic valves 100a, 100b can have the general structure of the prosthetic valve 100 described with reference to Figs. 2A-2B, though in some examples, each of the prosthetic valves 100a, 100b can be a different type of prosthetic valve. For example, a balloon expandable guest valve 100b can be implanted inside a previously implanted mechanically expandable or self-expandable host valve 100a.

[0097] During implantation of the prosthetic valve 100b, the prosthetic valve 100b is positioned within a central region defined between the leaflets 114a of the prosthetic valve 100a, which now take the role of host leaflet 10. The prosthetic valve 100b is then radially expanded against the host leaflets 10 (i.e., against the prosthetic valve leaflets 114c). Asillustrated, the radial expansion of the prosthetic valve 100a results in outward displacement of the host leaflets 10. As further illustrated, the host leaflets 10 are displaced such that the host leaflets 10 contact the aortic root 22 at positions superior to the coronary artery ostia 42, 44, causing coronary artery ostia obstruction. Alternatively, the guest prosthetic valve 100b can displace the host leaflets 114a outwardly against the frame 102a of the host valve 100a, thereby blocking the flow of blood through the frame 102a to the coronary ostia 42, 44.

[0098] In some patient anatomies (for example, when the outflow end 106 of the prosthetic valve 100 is at the STJ level 28 and the diameter of the prosthetic valve 100 is similar to the STJ diameter such that the frame 102 touches or is very close to the aortic wall 38 at the STJ level 28), the host leaflets 10 may compromise the ability for future access into the coronary arteries 34, 36 or perfusion through the frame 102 to the coronary arteries 34, 36 during the diastole phase of the cardiac cycle. Similar problems may occur in some patient anatomies either when a guest prosthetic valve 100b is percutaneously expanded within a previously implanted host prosthetic valve 100a, or when a prosthetic valve 100 is percutaneously expanded within a native valve, displacing the native leaflets 30 outward toward the coronary ostia 42, 44.

[0099] The risk illustrated in Fig. 3 may be higher when the host valve is a bioprosthetic valve without a frame or when the leaflets of the host valve are external to a frame. Risk of coronary artery ostia obstruction can increase in a cramped aortic root or when the coronary artery ostium sits low. In the examples illustrated in Figs. 2A-3, the host leaflets 10 are shown obstructing both coronary artery ostia 42, 44. In some cases, only one host leaflet 10 may obstruct a respective coronary artery ostium. For example, the risk of obstructing the left coronary ostium 42 tends to be greater than obstructing the right coronary ostium 44 because the left coronary ostium 42 typically sits lower than the right coronary ostium 44.

[0100] The term “host valve” as used herein refers to a native heart valve in which a prosthetic valve is implanted or a previously implanted prosthetic valve in which a new prosthetic valve is implanted. Moreover, in any of the examples disclosed herein, when the host valve is a previously implanted prosthetic valve, the host valve can be a surgically implanted prosthetic heart valve (known as a “surgical valve”) or a transcatheter heart valve. The term “guest valve”, as used herein, refers to a prosthetic valve implanted in a host valve, which can be either a native heart valve or a previously implanted prosthetic valve. Similarly, the term “host leaflets 10”, as used herein, refers to native leaflets 30 of a native valve in which a new guest prosthetic valve 100 is implanted, or to prosthetic valve leaflets 114a of a previously implanted host valve 100a in which a new guest prosthetic valve 100b is implanted.

[0101] When a guest prosthetic valve 100 is deployed inside a host valvular structure 12, it displaces the host leaflets 10 of the host valve radially outwards, towards and against a host interior surface 14, which can be the interior surface of the aortic wall 38 if the host valve is the native valve, or an interior surface of the frame 102a of a previously implanted prosthetic valve 100a serving as the host valve.

[0102] To avoid obstruction of blood flow to the coronary arteries 34, 36, the valvular structure 12 of the existing host valve (whether a native aortic valve or a previously implanted prosthetic valve) can be modified by components of a delivery apparatus prior to or during implantation of a new prosthetic valve within the existing valvular structure 12. In some examples, the host valvular structure 12 is modified by piercing, lacerating, tearing, slicing, and / or cutting one or more host leaflets 10 (for example, a free end of the host leaflet 10 or a commissure of adjacent host leaflets 10, which can be a native commissure 40 for a native aortic valve 20, or a prosthetic valve commissure 116 for a previously implanted host prosthetic valve 100) using the delivery apparatus. The modification thus disrupts the impermeable tubular structure that would otherwise be formed by the existing host leaflets 10, thereby allowing blood to flow to the coronary arteries 34, 36.

[0103] Fig. 4 illustrates an exemplary tissue modification apparatus 200 that includes an expansion member 260 axially movable through and relative to a needle 212. Figs. 5A-5B show perspective sectional views of a distal portion of the tissue modification apparatus 200 in different positions of components of the apparatus 200 relative to each other. Figs. 5C shows a cross-sectional view of the distal portion of the tissue modification apparatus 200 of Fig. 5B. The tissue modification apparatus 200 can include a handle 202, a delivery catheter 206 attached to the handle 202 and distally extending therefrom, a needle 212 that can extend through a lumen 208 of the delivery catheter, and a dilation assembly 242 that can extend through a lumen 214 of the needle 212. The terms “tissue modification apparatus 200” and “apparatus 200”, as used herein, are interchangeable.

[0104] In some examples, the needle 212 and the delivery catheter 206 can be configured to be axially movable relative to each other. For example, a distally oriented movement of the needle 212 relative to the delivery catheter 206, and / or a proximally oriented movement of the delivery catheter 206 relative to the needle 212, can expose a needle head 216 of the needle 212 out the delivery catheter lumen 208.

[0105] The dilation assembly 242 includes an expansion member 260 configured to transition between a compacted state and an expanded state. The expansion member 260 can be configured to reside in a compacted state inside a lumen 214 of the needle 212, and whenpositioned inside a pilot puncture 50 that can be formed, by the needle 212, in a target tissue, it can be expanded to dilate the pilot puncture 50 and form a tissue opening 52, which can be referred to as a leaflet opening 52 when the target tissue of a host leaflet 10 of a host valvular structure 12.

[0106] In some examples, the dilation assembly 242 and the needle 212 can be configured to be axially movable relative to each other. For example, a distally oriented movement of the dilation assembly 242 relative to the needle 212, and / or a proximally oriented movement of the needle 212 relative to the dilation assembly 242, can expose a distal portion of the dilation assembly 242, which can include the expansion member 260, out the needle lumen 214.

[0107] In some examples, the tissue modification apparatus 200 further comprises a protective shaft 232 disposed inside a lumen of the needle 212, optionally between the needle 212 and the dilation assembly 242. In some examples, the dilation assembly 242 can extend through a lumen 234 of the protective shaft 232.

[0108] In some examples, the protective shaft 232 and the needle 212 can be configured to be axially movable relative to each other. For example, a distally oriented movement of the protective shaft 232 relative to the needle 212, and / or a proximally oriented movement of the needle 212 relative to the protective shaft 232, can expose a distal end portion 236 of the protective shaft 232 out the needle lumen 214.

[0109] In some examples, the dilation assembly 242 and the protective shaft 232 can be configured to be axially movable relative to each other. For example, a distally oriented movement of the dilation assembly 242 relative to the protective shaft 232, and / or a proximally oriented movement of the protective shaft 232 relative to the dilation assembly 242, can expose a distal portion of the dilation assembly 242, which can include the expansion member 260, out the protective shaft lumen 234.

[0110] In some examples, the expansion member comprises a hole-dilating balloon 260 mounted on a balloon catheter 254. The hole-dilating balloon 260 is configured to transition between a radially deflated state (which can be its compacted state), shown for example in Figs. 4-5C, 6F and 7A, and a radially inflated state (which can be its expanded state), shown for example in Figs. 6G and 7B.

[0111] In some examples, the balloon catheter 254 and the needle 212 can be configured to be axially movable relative to each other. For example, a distally oriented movement of the balloon catheter 254 relative to the needle 212, and / or a proximally oriented movement of the needle 212 relative to the balloon catheter 254, can expose the hole-dilating balloon 260 out the needle lumen 214.

[0112] In some examples, the balloon catheter 254 and the protective shaft 232 can be configured to be axially movable relative to each other. For example, a distally oriented movement of the balloon catheter 254 relative to the protective shaft 232, and / or a proximally oriented movement of the protective shaft 232 relative to the balloon catheter 254, can expose the hole-dilating balloon 260 out the protective shaft lumen 234.

[0113] In some examples, the handle 202 can include a steering mechanism configured to adjust the curvature of the distal end portion of the apparatus 200. In the illustrated example, the handle 202 can include an adjustment member, such as the illustrated rotatable knob 204a, which in turn is operatively coupled to the proximal end portion of a pull wire (not shown). The pull wire can extend distally from the handle 202 through the delivery catheter 206 and has a distal end portion affixed to the delivery catheter 206 at or near the distal end 210 of the delivery catheter 206. Rotating the knob 204a can increase or decrease the tension in the pull wire, thereby adjusting the curvature of the distal end portion of the apparatus 200. Further details on steering or flex mechanisms for the system can be found in U.S. Patent No. 9,339,384, which is incorporated by reference herein.

[0114] The handle 202 can include additional adjustment mechanisms controllable by additional knobs to maneuver additional components of the apparatus 200, such as axial movement of needle 212 and / or axial movement of a protective shaft 232, relative to other shafts or catheters of the apparatus 200, as will be elaborated in greater detail below.

[0115] The proximal ends of any of the delivery catheter 206, the needle 212, the protective shaft 232, and / or balloon catheter 254, can be coupled to the handle 202. During advancement through a patient's vasculature, the handle 202 can be maneuvered by an operator (for example, a clinician or a surgeon) to axially advance or retract components of the apparatus 200, such as the delivery catheter 206, the needle 212, the protective shaft 232, and / or balloon catheter 254.

[0116] The needle 212 comprises a needle head 216 and a needle shaft 224 extending proximally from the needle head 216, collectively defining a needle lumen 214 through which the protective shaft 232 can extend. The needle head 216 is configured to pierce a target tissue, such as a host leaflet 10 of a host valvular structure 12, to form a pilot puncture 50 in the host leaflet 10. The needle head 216 can define an angled surface 222 terminating at a sharp needle tip 220 configured to facilitate piercing the host leaflet 10 when the needle 212 is pressed thereagainst.

[0117] In some examples, at least a portion of the needle shaft 224 comprises slits arranged in a desired pattern, such as that of known hypo-tubes, to enhance flexibility thereof. In the example illustrated in Figs. 4-5C, at least part of the needle shaft 224, such as a distal portion226 thereof, is shown to include a plurality of circumferential slits 228 axially spaced from each other, so as to form circumferential bands separating between adjacent circumferential slits 228, with axially extending connecting portions connecting adjacent bands. Two adjacent circumferential bands can be connected by a plurality of angularly spaced connecting portions defined between ends of corresponding circumferential slits 228. In such arrangements, the slitted part of the needle shaft 224, such as the distal portion 226, exhibits sufficient flexibility to allow it to flex as it is pushed through a tortuous pathway without kinking or buckling, and / or to bend when passed through bent portions of the vasculature and / or through bends of a catheter is extends through.

[0118] While a specific pattern is illustrated in Figs. 4-5C, which can be a laser cut pattern, it is to be understood that the pattern of slits 228 and / or the size of the slits 228 and / or axial distances between the slits 228 can vary along the length of the corresponding slitted part of the needle shaft 224 in order to vary stiffness of the slitted part of the needle shaft 224 along its length. For example, the axial distance between adjacent slits 228 can decrease from the proximal end to the distal end of the slitted part of the needle shaft 224 to provide greater stiffness near the proximal end and greater flexibility near the distal end of the needle shaft 224.

[0119] In some examples, the slitted part of the needle shaft 224 can extend along the entire length of the needle shaft 224 or at least a significant portion of a length thereof. In some examples, the needle shaft 224 can include a distal portion 226 that includes slits, such as slits 228, and a proximal portion 230 extending proximally from the distal portion 226, which can be devoid of slits, as illustrated in Fig. 5A. In some examples, the distal portion 226 and the proximal portion 230 of the needle shaft 224 are separate components that can be affixed to each other, and may be made from similar or different materials. For example, a laser-cut metallic tube that includes slits 228 can be used to form the distal portion 226, while the proximal portion 230 can be made of a polymeric material. The distal portion 226 can allow for increased flexibility along a distal part of the needle 212, allowing it to be steered towards a target tissue, such as a host leaflet 10, to improve precision of positioning and penetration, while the polymeric proximal portion 230, devoid of such slits, may be less flexible than the distal portion 226, yet flexible enough to allow it to passively bend along curved portions of the patient's vasculature, for example.

[0120] In some examples, the distal portion 226 extends along less than 50% of the length of the entire needle shaft 224. In some examples, the distal portion 226 extends along less than 30% of the length of the entire needle shaft 224. In some examples, the distal portion 226extends along less than 25% of the length of the entire needle shaft 224. In some examples, the distal portion 226 extends along less than 20% of the length of the entire needle shaft 224.

[0121] In some implementations of a needle 212, the length of the needle shaft 224 extending through a patient's vasculature, all the way to a host leaflet 10, such as a leaflet in an aortic valve, can be in the order of more than 2 meters, such as between 2-3 meters or even longer. Laser cutting metallic tubes have such lengths can be costly. Limiting the distal portion 226 of the needle shaft 224 to be formed as a hypotube, while the optionally longer proximal portion 230 is made of a polymeric material, can advantageously reduce manufacturing costs. The proximal portion 230 can be affixed, at its distal end, to a proximal end of the distal portion 226, by any method known in the art such as gluing, overmolding, and the like.

[0122] While the needle shaft 224 is shown in the example illustrated in Fig. 5A to be formed of a distal portion 226 that includes slits 228, and a proximal portion 230 devoid of slits, it is to be understood any exemplary needle shaft 224 disclosed herein can be, in some examples, slitted along its entire length, such as by being made of a metallic laser-cut hypotube that defines the entirety of the needle shaft 224.

[0123] In some examples, the needle head 216 can be continuous with and / or integrally formed with the distal portion 226. For example, when the distal portion 226 is formed from a metallic tube, the needle head 216 can be an integral extension of the tube, together forming a unitary component. In some examples, the needle head 216 can be devoid of slits. In some examples, the needle head 216 can include slits, such as head slits 218 shown in Fig. 5A. The head slits 218 can extend between edges of the angled surface 222, and can vary in size due to narrowing of the needle head 216 towards the needle tip 220. In some examples, the pattern of the head slits 218 can be different from the pattern of the needle shaft circumferential slits 228, as illustrated in Fig. 5A.

[0124] A needle 212 of any exemplary tissue modification apparatus 200 disclosed herein can be referred to as a relatively large-diameter needle, differing from conventionally sized needles of percutaneously-deliverable medical devices, to allow for passage of an expansion member, such as a balloon catheter 254 with hole-dilating balloon 260, therethrough. The relatively enlarged diameter of such a needle can also result in a larger-than-usual needle head 216. Examples in which head slits 218 are formed in the needle head 216 can increased flexibility of the needle head 216 as well, to improve precision of positioning and penetration thereof.

[0125] The balloon catheter 254 can define a balloon catheter lumen 256 through which a guidewire 80, and one or more additional shafts of the apparatus 200, can optionally extend. The balloon catheter 254 can be fluidly connectable to a fluid source (not shown) for inflatingthe hole-dilating balloon 260. The fluid source comprises an inflation fluid. The term "inflation fluid", as used herein, means a fluid (for example, saline, though other liquids or gas can be used) used for inflating the balloon 260. The inflation fluid source is in fluid communication with the balloon catheter lumen 256, such that fluid from the fluid source can flow through the balloon catheter lumen 256 into hole-dilating balloon 260 to inflate it.

[0126] In some examples, the dilation assembly can further include a dilator 244 positioned distal to the hole-dilating balloon 260 (or other suitable expansion member 260). The dilator 244 can be conical or frustoconical in shape, and include a dilator tapering portion 248 terminating at a dilator distal end 246, and a dilator proximal portion 250 that can be coupled to a dilator shaft 262 that extends proximally therefrom. The dilator shaft 262 and dilator 244 collectively define a dilator lumen 252 open ended at the dilator distal end 246. Attachment of the dilator shaft 262 to the dilator proximal portion 250 can be achieved by a variety of methods, such as overmolding, radio-frequency welding, through an adhesive, and / or a combination thereof. In some examples (not illustrated), the dilator shaft 262 can extend through the entire length of the dilator 244, such that a distal end of the dilator shaft 262 is aligned with the dilator distal end 246. In some examples (not illustrated), the dilator shaft 262 is coupled to one or more components, such as collars or other connectors, which are in turn attached to the dilator 244. The dilator lumen 252 can be sized to allow passage of a guidewire 80 (shown, for example, in Figs. 6A-6I) therethrough.

[0127] In some examples, the hole-dilating balloon 260 is coupled to a distal end portion of the balloon catheter 254 at its proximal end, while the balloon's distal end can be coupled, directly or indirectly, to another component of the dilator assembly 242, such as the dilator 244 or dilator shaft 262. In the example illustrated in Figs. 5A-5C, the hole-dilating balloon 260 is shown to be coupled to the dilator proximal portion 250. The dilator proximal portion 250 can optionally include an outer step configured to accommodate the distal end of the balloon 260, such that the outer surface of the balloon 260 can be flush or otherwise relatively continuous with the outer surface of the dilator 244.

[0128] In some examples, such as when the hole-dilating balloon 260 is attached at both ends thereof to the dilator 244 and balloon catheter 254, both the dilator 244 with dilator shaft 262 and the balloon catheter 254 can be configured to move simultaneously in the axial direction, without necessarily being axially movable relative to each other, or while axial movement of one relative to the other is limited. In such examples, axial movement of the balloon catheter 254 is configured to cause movement of the dilator shaft 262 therewith, or axial movement ofone of the dilator shaft 262 or dilator 244 is configured to cause movement of the balloon catheter 254 therewith.

[0129] The dilator shaft 262 can extend through the balloon catheter lumen 256, and may be sized such that an annular space is formed within balloon catheter lumen 256 between an inner surface of the balloon catheter 254 and an outer surface of the dilator shaft 262 along the length of balloon catheter 254. This annular space is in fluid communication with one or more inflation openings 258 exposed to an internal cavity of the hole-dilating balloon 260, which can be in fluid communication with a fluid source (for example, a syringe or a pump) that can inject inflation fluid into the hole-dilating balloon 260, so as to inflate the balloon 260, for example during formation of a leaflet opening 52 as will be described in greater detail below and shown, for example, in Fig. 6G. The pressure of the inflation fluid within hole-dilating balloon 260 may provide the force that allows it to dilate a leaflet opening 52. Further, the balloon catheter lumen 256 may be configured to withdraw fluid from the balloon 260 through the inflation opening(s) 258, to deflate the balloon 260.

[0130] In some examples, an inflatable balloon 260 of apparatus 200, utilized as a hole-dilating balloon, can be different from a typical balloon used for expanding balloon-expandable prosthetic valves or stents, in that while a typical valve-expanding balloon is inflatable to a diameter that can allow expansion of a prosthetic valve to a functional diameter thereof, which can be similar to, or greater than (for example, in the case of valve over-expansion) the diameter of the native annulus in which the valve is deployed, the maximum diameter of a hole-dilating balloon 260 can be significantly smaller, configured to increase the size of a pilot puncture 50 to form a larger leaflet opening 52, optionally without tearing the host leaflet 10 (though in some examples, the host leaflet 10 may be still torn by a hole-dilating balloon 260).

[0131] In some examples, such as when dilation of a pilot puncture 50 is desired to form a larger leaflet opening 52, without necessarily tearing the leaflet 10, the maximum diameter to which the hole-dilating balloon 260 can be inflated is equal to or less than 12 mm. In some examples, the maximum diameter to which the hole-dilating balloon 260 can be inflated is equal to or less than 10 mm. Nevertheless, as mentioned above, in some examples a holedilating balloon 260 can be configured to tear a host leaflet 10, in which case the maximum diameter to which the hole-dilating balloon 260 can be greater than 12 mm., such as in a range of 20-25 mm.

[0132] As mentioned above, the apparatus 200 can include a protective shaft 232 disposed between the needle 212 and the balloon catheter 254. The protective shaft 232 extends through the needle lumen 214, and defines a protective shaft lumen 234 through which the hole-dilatingballoon 260 and balloon catheter 254 can extend. The protective shaft 232 can include a distal end portion 236 which can have, in some examples, an atraumatic distal edge 238, such as by being rounded or otherwise blunted. The shaft distal end portion 236 can be formed as an integral distal portion of the protective shaft 232, or as a separate component attached to the protective shaft 232. While the distal edge 238 of the shaft distal end portion 236 is shown to be angled in the examples illustrated in Fig. 5A-5C, it is to be understood that this shape of the shaft distal end portion 236, optionally matching the shape of the needle head 216, is shown by way of illustration and not limitation, and that any other shape of the shaft distal end portion 236 is contemplated, including having a substantially circular shaft distal edge 238. When provided as an angled shaft distal edge 238, the shaft distal end portion 236 can terminate at a shaft atraumatic tip 240.

[0133] In some examples, at least a portion of the protective shaft 232 comprises slits arranged in a desired pattern, such as that of known hypo-tubes, to enhance flexibility thereof. In the example illustrated in Figs. 4-5C, at least part of the protective shaft 232, such as a distal portion thereof, is shown to include a plurality of circumferential slits 233 axially spaced from each other, so as to form circumferential bands separating between adjacent circumferential slits 233, with axially extending connecting portions connecting adjacent bands. Two adjacent circumferential bands can be connected by a plurality of angularly spaced connecting portions defined between ends of corresponding circumferential slits 233. In such arrangements, the slitted part of the protective shaft 232 exhibits sufficient flexibility to allow it to flex as it is pushed through a tortuous pathway without kinking or buckling, and / or to bend when passed through bent portions of the vasculature and / or through bends of a catheter is extends through.

[0134] While a specific pattern is illustrated in Figs. 4-5C, which can be a laser cut pattern, it is to be understood that the pattern of slits 233 and / or the size of the slits 233 and / or axial distances between the slits 233 can vary along the length of the corresponding slitted part of the protective shaft 23 2in order to vary stiffness of the slitted part of the protective shaft 232 along its length. For example, the axial distance between adjacent slits 233 can decrease from the proximal end to the distal end of the slitted part of the protective shaft 232 to provide greater stiffness near the proximal end and greater flexibility near the distal end of the protective shaft 232.

[0135] When a balloon catheter 254 carrying an inflatable hole-dilating balloon 260 extends through the needle 212, it may be important to protect the hole-dilating balloon 260 from being accidentally contacted by the sharp needle tip 220. Thus, a protective shaft 232 that can bedisposed between the needle head 216 and the hole-dilating balloon 260 can advantageously protect the hole-dilating balloon 260 from being punctured by the needle’s sharp tip 220.

[0136] Various exemplary implementations for apparatus 200 and / or components thereof can be referred to, throughout the specification, with superscripts, for ease of explanation of features that refer to such exemplary implementations. It is to be understood, however, that any reference to structural or functional features of any apparatus, device or component, without a superscript, refers to these features being commonly shared by all specific exemplary implementations that can be also indicated by superscripts. In contrast, features emphasized with respect to an exemplary implementation of any apparatus, device or component, referred to with a superscript, may be optionally shared by some but not necessarily all other exemplary implementations. For example, an apparatus 200a, illustrated in Figs. 5A-5C, is an exemplary implementation of apparatus 200, and thus can include any of the features described for apparatus 200 throughout the current disclosure, except that the diameter of the delivery catheter lumen 208 can closely match an outer diameter of the needle 212, without including any additional shaft disposed between the needle 212 and delivery catheter 206.

[0137] The delivery catheter 206 has a delivery catheter distal end portion 210 which can be, in some examples, an atraumatic distal end portion 210, such as by being rounded and / or being curved radially inwards, or otherwise formed to include an outer surface tapering in the distal direction. In some examples, the needle head 216 can be maintained inside the delivery catheter lumen 208, axially positioning the sharp needle tip 220 at or proximal to the delivery catheter distal end portion 210, to conceal the sharp needle tip 220 from the surrounding anatomy during delivery, thereby mitigating the risk of the sharp needle tip 220 contacting and / or damaging any anatomical structure prior to reaching the site of treatment. In such examples, the diameter of delivery catheter lumen 208 is greater than an outer diameter of needle 212, including needle head 216.

[0138] Fig. 5 A shows a distal portion of the apparatus 200 with part of the needle 212 extending out of the lumen 208 of delivery catheter 206, such that the needle head 216 is positioned distal to the delivery catheter distal end 210. This position can be representative of the configuration of apparatus 200 during formation of a pilot opening 50, having the needle 212 distally advanced to puncture a target tissue, such as a host leaflet 10. The protective shaft 232, including the shaft distal end portion 236, is shown in Fig. 5A to remain inside the needle lumen 214, and the dilation assembly 242, including the hole-dilating balloon 260, is positioned inside protective shaft lumen 234, proximal to the needle head 216.

[0139] Figs. 5B and 5C show a perspective sectional view and a cross-sectional side view, respectively, of the distal end portion of the apparatus 200 of Fig. 5A, with the protective shaft 232 advanced through the needle lumen 214 such that the shaft distal end portion 236 is distal to the needle head 216. In this position, the dilation assembly 242 can be distally advanced through protective shaft lumen 234 to position the hole-dilating balloon 260 distal to the needle head 216 and the shaft distal end portion 236, while the protective shaft 232 protect the balloon 260 from being engaged by the needle tip 220.

[0140] It is to be understood that any reference throughout the specification and the claims, to two components which are axially movable relative to each other, is not limited to both of the components being able to axially move relative to the other when the other component is maintained axially immovable, but rather to either one of the components being axially movable relative to the other component, or both being axially movable relative to each other. For example, a reference to a needle and a dilation assembly being axially movable with respect to each other can refer either to the needle being movable in the proximal or distal direction relative to the dilation assembly, top the dilation assembly being movable in the proximal or distal direction relative to the needle, or both.

[0141] Figs. 6A-6H illustrate some steps in a method for utilizing an apparatus 200 for forming an opening within a target tissue. An exemplary implementation of the method is illustrated in Figs. 6A-6H with respect to forming a leaflet hole inside a host leaflet, which can be performed prior to implanting a guest prosthetic valve inside the host valvular structure, as further described below with respect to Figs. 6I-6J for example. The apparatus 200 can be used to perforate a host leaflet 10, such as a native leaflet 30 or a prosthetic valve leaflet 114 of a previously implanted prosthetic valve.

[0142] The distal end portion of the apparatus 200, which can include a distal end 210 of the delivery catheter 206 and / or the dilator 244 of dilation assembly 242, is configured to be inserted into a patient’s vasculature, such as within an ascending aorta, and to be advanced towards the host leaflet 10. Positioning the distal end 210 of the delivery catheter 206 and / or the dilator 244 relative to the host leaflet 10 may comprise advancing the delivery catheter 206 and / or dilator 244 toward the leaflet over a guidewire 80. For example, the guidewire 80 can be inserted into the patient’ s vasculature, and then the dilator shaft 262 and / or other shafts or tubes of the apparatus 200 may be advanced toward the host leaflet 10 over the guidewire 80.

[0143] As mentioned above, during delivery, the needle head 216 can be retained inside the delivery catheter lumen 208, such that the sharp needle tip 220 is at or proximal to the delivery catheter distal end 210. This position conceals the needle tip 220 from the surroundinganatomy, to protect the anatomical structures from being engaged or punctured by the sharp needle tip 220 during advancement towards the site of treatment.

[0144] The protective shaft 232 can extend through the needle lumen 214 so as to protect the hole-dilating balloon 260 from being contacted by the needle tip 220. Upon reaching the site of treatment, such as the host valvular structure 12, the needle 212 can be advanced towards the host leaflet 10. In some examples, prior to, or simultaneously with, advancement of the needle 212 towards the host leaflet 10, the protective shaft 232 can be distally advanced, relative to the balloon catheter 254, closer to, and optionally up to contact or close proximity with, the host leaflet 10, as shown in Fig. 6A.

[0145] The needle 212 is distally advanced to puncture the host leaflet 10 to form a pilot puncture 50 within host leaflet 10 as shown in Fig. 6B, for example when the needle head 216 is axially translated relative to dilation assembly 242. Once the needle head 216 is positioned, at least partially, past the host leaflet 10, the guidewire 80 can be optionally advanced through the needle lumen 214 to terminate with guidewire tip 82 at a position distal to the pilot puncture 50 of host leaflet 10.

[0146] While Figs. 6A-6B illustrate the protective shaft 232 advanced distally relative to the delivery catheter 206 prior to and / or during puncturing the host leaflet 10 by needle 212, in some examples, the delivery catheter 206 can be advanced up to contact with the host leaflet 10 prior to puncturing the host leaflet 10 by the needle 212. The delivery catheter 206 can apply a limited extent of a distally oriented push-force against the host leaflet 10. The delivery catheter 206, in such examples, can provide an external support structure through which the needle head 216 can be advanced and passed through the leaflet 10, in a manner that increases stability of the leaflet as the needle head 216 penetrates therethrough.

[0147] Nevertheless, for instances in which a protective shaft 232 is distally advanced up to contact with the host leaflet 10 prior to forming a pilot puncture in the leaflet 10, as illustrated in Figs. 6A-6B, similar advancement of the delivery catheter 206 is not necessarily required, as the protective shaft 232 can similarly apply a limited extent of a distally oriented push-force against the host leaflet 10, during advancement of the needle 212 thereover towards and through the host leaflet 10. The protective shaft 232, in such examples, can provide an internal support structure over which the needle head 216 can be advanced and passed through the leaflet 10, in a manner that similarly increases stability of the leaflet as the needle head 216 penetrates therethrough.

[0148] Subsequent to forming the pilot puncture 50 and optionally advancing the guidewire 80, the protective shaft 232 can be passed through the needle lumen 214 past the pilot puncture50, and as shown in Fig. 6C, and the needle 212 can be proximally retracted out of the host leaflet 10, as shown in Fig. 6D. Is some examples, the protective shaft 232 is distally pushed so as to position the shaft distal end portion 236 distal to the pilot puncture 50 while the needle 212 is kept in position, extended through the host leaflet 10, as illustrated in Fig. 6C, in which case the needle 212 can provide support to the protective shaft 232 as it distally slides over the needle 212 to pass through the host leaflet 10.

[0149] In some examples, the needle 212 can be proximally retracted out of the host leaflet 10 prior to passing the protective shaft 232 thorough the pilot puncture 50, while the guidewire 80 remains in position, extended through the host leaflet 10. The protective shaft 232 can be then advanced, over the guidewire 80, into and through the host leaflet 10, positioning the shaft distal end portion 236 distal to the pilot puncture 50. In such examples, an angled distal edge 238 formed in the shaft distal end portion 236 can facilitate insertion of the protective shaft 232 into the pilot puncture 50.

[0150] In some examples, the guidewire 80 can be advanced simultaneously with advancement of the needle 212 during formation of the pilot puncture 50. In some examples, the guidewire 80 can be advanced to terminate distal to the host leaflet 10 after formation of the pilot puncture 50 by the needle 212. In some examples, the guidewire 80 can be advanced to terminate distal to the host leaflet 10 prior to advancement of the protective shaft 232 through the pilot puncture 50. In some examples, the guidewire 80 can be advanced simultaneously with advancement of the protective shaft 232 into and through the pilot puncture 50 after formation of the pilot puncture 50 by the needle 212.

[0151] As shown in Fig. 6E, the dilation assembly 242 can be then distally advanced through the protective shaft lumen 234, to position the hole-dilating balloon 260 inside of the pilot puncture 50. Advantageously, the protective shaft 232 protects the hole-dilating balloon 260 from being contacted by the sharp needle tip 220 during retraction of the needle head 216 and / or advancement of the dilating assembly 242.

[0152] With the balloon 260 positioned at the level of the pilot puncture 50 and the needle head 216 proximally pulled away from the leaflet 10, such that it no longer poses a risk of engaging with the balloon 260, the protective shaft 232 is proximally pulled relative to the dilation assembly 242, so as to expose the hole-dilating balloon 260 as shown in Fig. 6F.

[0153] While the protective shaft 232 is shown to extend through the pilot puncture 50 in Figs. 6C-6E, in some examples, the shaft distal end portion 236 can be positioned at or proximal to the host leaflet 10. In such examples, the needle head 216 can be similarly retracted from the host leaflet 10, after which the dilation assembly 242 can be distally advanced through theprotective shaft lumen 234, exposing dilator 244 out of the shaft distal end portion 236 prior to and / or during passage thereof through the pilot puncture 50. Positioning of the hole-dilating balloon 260 within the pilot puncture 50 can be achieved by further advancement of the dilation assembly 242.

[0154] With the hole-dilating balloon 260 received within the pilot puncture 50 and exposed out of the protective shaft 232, inflating the hole-dilating balloon 260 to transition it from a radially deflated state (Fig. 6F) to a radially inflated state (Fig. 6G) can expand the pilot puncture 50 to form a leaflet opening 52 that is sized to receive the prosthetic valve 100 in the radially compressed or crimped configuration. After the hole-dilating balloon 260 is inflated to form the leaflet opening 52 as shown in Fig. 6G, the balloon 260 is deflated, as shown in Fig. 6H, optionally allowing for insertion of a guest prosthetic valve inside the leaflet opening 52.

[0155] In some examples, inflating the hole-dilating balloon 260 within the host leaflet 10 serves to increase a diameter of the pilot puncture 50 such that the resulting leaflet opening 52 is a hole with an increased diameter relative to the pilot puncture 50. In some examples in which the leaflet opening 52 is a hole, the leaflet opening 52 may be a substantially circular hole. In some examples, the leaflet opening 52 may be non-circular (for example, elliptical or asymmetric). In such examples, the diameter of the leaflet opening 52 may refer to any suitable dimension of the leaflet opening 52, such as a minimum diameter of the leaflet opening 52, a maximum diameter of the leaflet opening 52, and / or an average diameter of the leaflet opening 52.

[0156] In some examples, inflating the hole-dilating balloon 260 within the host leaflet 10 may cause the host leaflet 10 to rip and / or tear such that the leaflet opening 52 is not a bounded hole. Stated differently, in such examples, the leaflet opening 52 may be formed by a tear that extends from the pilot puncture 50 fully to the free edge of the host leaflet 10 (the coaptation edge of the leaflet).

[0157] While a dilation assembly 242 that includes a hole-dilating balloon 260 is described above and illustrated for expanding a pilot puncture 50 to form a leaflet opening 52, it is to be understood that other types of expansion member can be used instead of a balloon in any of the methods and / or systems described herein. For example, U.S. Provisional Application No. 63 / 335,739, which is incorporated herein by reference in its entirety, describes an expandable frame that can be used as an expansion member instead of a valve-expanding balloon.

[0158] In some examples, retraction of the hole-dilating balloon 260, after deflation thereof, can be performed while the guidewire 80 may be kept in position, extending through the leaflet opening 52. Subsequent to deflation of the hole-dilating balloon 260 (or recompressing of anyother type of an expansion member) inside the leaflet opening 52 and retracting it away from the host leaflet 10, the method can further include steps of positioning a guest prosthetic valve 100 inside the leaflet opening 52. A replacement valve delivery apparatus 350 carrying the guest prosthetic valve 100 can be either part of the apparatus 200, or provided as a separate assembly of apparatus 350 advanced into a leaflet opening 52.

[0159] Fig. 61 shows a guest prosthetic valve 100 positioned, in a radially compressed configuration thereof, inside the leaflet opening 52. As shown in Fig. 61, the guest prosthetic valve 100 can he mounted on a replacement valve delivery apparatus 350 that can be advanced towards the host leaflet 10 over a guidewire, which can be a separate guidewire (not shown), or can be the same guidewire 80.

[0160] In some examples, the guest prosthetic valve is a balloon expandable valve, and the replacement valve delivery apparatus 350 comprises a balloon catheter 352 carrying a valveexpanding balloon 354. In contrast to some examples of a hole-dilating balloon 260 described above, such as a hole-dilating balloon 260 configured to form a leaflet opening 52 without tearing the host leaflet, the maximum diameter to which a valve-expanding balloon 354 can be inflated can be, in some examples, greater than 18 mm., greater than 20 mm., greater than 23 mm., greater than 26 mm., and / or greater than 29 mm.

[0161] While a replacement valve delivery apparatus 350 equipped with a valve-expanding balloon 354 at a distal end portion of a balloon catheter 352 is illustrated, it is to be understood that this is shown by way of illustration and not limitation, and that a replacement valve delivery apparatus 350 can include other shafts and / or mechanisms, for example when utilized to advance and expand other types of replacement prosthetic valves, such as self-expandable prosthetic valves or mechanically expandable prosthetic valves.

[0162] In some examples, the replacement valve delivery apparatus 350 can further include a nosecone 356 positioned distal to the valve-expanding balloon 354 (or other prosthetic-valve expanding mechanism). The nosecone 356 can be conical or frustoconical in shape. The nosecone 356 can be attached to a distal end of a nosecone shaft 358 extending through the balloon catheter 352, wherein the nosecone 356 and the nosecone shaft 358 can collectively define a lumen through which a guidewire can extend. In some examples, when a nosecone 356 is present at a distal end of the replacement valve delivery apparatus 350 as also shown in the example illustrated in Fig. 61, the nosecone 356 can be advanced towards the host leaflet 10, and may optionally have a maximal diameter that can be somewhat greater than the diameter of the opening 52, such that as the nosecone 356 is inserted into the leaflet opening 52 it can optionally further expand the leaflet opening 52 to a greater diameter.

[0163] As shown in Fig. 61, the guest prosthetic valve 100 is placed in the leaflet opening 52 in its radially compressed configuration, optionally positioned over a deflated valve-expanding balloon 354 in the case of a balloon-expandable prosthetic valve. With the prosthetic valve 100 received within the leaflet opening 52, radially expanding the guest prosthetic valve 100, as shown in Fig. 6J, can serve to increase a size of the leaflet opening 52 and / or to tear the leaflet. As a result, and as discussed above, radially expanding the guest prosthetic valve 100 can serve to modify the host leaflet 10 such that the leaflet does not obstruct a cell opening 112 in a frame 102 of the guest prosthetic valve 100 or at least increases the area of the host valve and the guest valve that is not covered or obstructed by the modified host leaflet to permit access and sufficient perfusion to the adjacent coronary artery. For example, radially expanding the guest prosthetic valve within the leaflet opening 52 can operate to push a portion of the leaflet extending radially exterior of the guest prosthetic valve below an upper edge of an outer skirt of the guest prosthetic valve 100 and / or away from one or more cell openings 112 of the guest prosthetic valve 100.

[0164] In some examples, the guest prosthetic valve can be a mechanically-expandable prosthetic valve and radial expansion thereof can be achieved by actuating a mechanical actuator of the guest prosthetic valve to mechanically expand a frame of the guest prosthetic valve. In some examples, the guest prosthetic valve can be a self-expandable prosthetic valve that can be retained during delivery toward the host valvular structure in a capsule or other restraint disposed therearound, and valve expansion can be achieved by removing the capsule or other restraint from the guest prosthetic valve to allow it to radially self-expand within the host valvular structure.

[0165] Figs. 7A-8B illustrate a sequence of events in which a host valvular structure 12 is modified to receive a guest prosthetic valve 100. Figs. 7A-7B illustrate the hole-dilating balloon 260 utilized to expand the pilot puncture 50 into the leaflet opening 52. In particular, Fig. 7A illustrates the hole-dilating balloon 260 in a deflated state within the pilot puncture 50, corresponding to the state described above with respect to Fig. 6F, while Fig. 7B illustrates the hole-dilating balloon 260 in an inflated state such that the pilot puncture 50 has enlarged into the leaflet opening 52, corresponding to the state described above with respect to Fig. 6G. Fig. 7C illustrates a guest prosthetic valve 100 that can be positioned in the leaflet opening 52 after removal of the hole-dilating balloon 260 therefrom, in a crimped configuration of the prosthetic valve 100, corresponding to the state described above with respect to Fig. 61, after which the guest prosthetic valve 100 can be expanded, such as by inflating a valve-expanding balloon354 over which it can be mounted in the case of a balloon-expandable valve, so as to implant the guest prosthetic valve 100 inside the host valvular structure 12.

[0166] As mentioned, any system, apparatus and method of the current specification can be utilized for forming a leaflet opening 52 in a host leaflet 10 which can be either a native leaflet 30 or a prosthetic valve leaflet 114 of a previously implanted prosthetic valve, such as prosthetic valve 100a of Fig. 3, such as in the case of ViV procedures. Fig. 8A shows a previously implanted prosthetic valve 100a subsequent to forming the leaflet opening 52. Fig. 14B shows a configuration in which a second prosthetic valve 100b has been expanded within the leaflet opening 52 of a host prosthetic valve 100a. In the example of Fig. 8B, the guest prosthetic valve 100b is the same type of valve as the host prosthetic valve 100a. It is to be understood, however, that ViV procedures may be similarly applied to any other suitable valvular structures, such as different prosthetic valves and / or native heart valves. For example, the guest prosthetic valve 100b need not be the same type of valve as the host prosthetic valve 100a.

[0167] In the example of Fig. 8A, when the prosthetic valve leaflets 114a of the previously implanted prosthetic valve 100a are pressed against the frame 102a, the leaflet opening 52 provides a partial access into the frame 102a, but the leaflet opening 52 may not be sufficiently large to completely uncover any of the cell openings 112a of the frame 102a.

[0168] As shown in Fig. 8B, however, fully expanding the guest prosthetic valve 100b within the leaflet opening 52 further expands and / or tears the leaflet opening 52 such that several cell openings 112a of the frame 102a of the host prosthetic valve 100a and several cell openings 112b of the frame 102b of the guest prosthetic valve 100b are fully uncovered by the leaflets 114a. In some examples, this may result from the frame 102b of the guest prosthetic valve 100b pushing the leaflet 114a comprising the leaflet opening 52 downwardly (toward the inflow ends of the prosthetic valves 100a, 100b) such that one or more cell openings 112a are unobstructed by the leaflet 114a. In some examples, expanding the frame 102b within the leaflet 114a comprising the leaflet opening 52 may rip and / or tear this leaflet 114a such that the leaflet 114a cannot obstruct one or more cell openings 112a.

[0169] Figs. 9A-10B show a distal portion of an exemplary tissue modification apparatus 200b, which is an exemplary implementation of apparatus 200, and thus can include any of the features described for apparatus 200 throughout the current disclosure, except that the apparatus 200bfurther comprises a steerable tube assembly 264 of Fig. 22A-22B, which defines a steerable assembly lumen 266 through which the needle 212 extends. The steerable tubeassembly 264 can include, in some examples, a pull-member 286 with one or more elongated pull-arms 290 disposed between an outer bendable tube 270 and an inner bendable tube 278.

[0170] Fig. 9A is a perspective view of a distal portion of an exemplary steerable tube assembly 264 disposed around the needle 212. Fig. 9B is a perspective view of a distal portion of the steerable tube assembly 264 of Fig. 9A, with the outer bendable tube 270 removed from view for illustrative purpose. Figs. 10A and 10B are cross-sectional side views of a distal portion of the apparatus 200bin unbent and bent states, respectively, of the steerable tube assembly 264. Figs. 9A-10B are described herein together.

[0171] The steerable tube assembly 264 can be axially movable through, and relative to, the delivery catheter 206, which can be either a non-steerable or a steerable delivery catheter 206. The outer bendable tube 270 of the steerable tube assembly 264 extends proximally from an outer tube distal end portion 272 towards the handle 202, and includes an outer tube slotted portion 274 along at least part of its length, such as along at least a distal section of the tube 270 adjacent outer tube distal end portion 272.

[0172] In some examples, the outer tube slotted portion 274 is formed as a hypotube, configured to increase flexibility of the outer bendable tube 270 along the outer tube slotted portion 274. The outer tube slotted portion 274 can include a plurality of slits 276 arranged in a manner that can provide sufficient flexibility to allow it to flex, either as it is pushed through a tortuous pathway or when the tube assembly 264 is actively articulated by actuating the pullmember 286, without kinking or buckling.

[0173] The inner bendable tube 278 of the steerable tube assembly 264 extends proximally from an inner tube distal end portion 280 towards the handle 202, and includes an inner tube slotted portion 282 along at least part of its length, such as along at least a distal section of the tube 278 adjacent inner tube distal end portion 280. In some examples, the inner tube slotted portion 282 is formed as a hypotube, configured to increase flexibility of the inner bendable tube 278 along the inner tube slotted portion 282. The inner tube slotted portion 282 can include a plurality of slits 284 arranged in a manner that can provide sufficient flexibility to allow it to flex, either as it is pushed through a tortuous pathway or when the tube assembly 264 is actively articulated by actuating the pull-member 286, without kinking or buckling.

[0174] The pull-member 286 comprises a pull-ring portion 288 and at least one elongated pullarm 290 extending proximally from the pull-ring portion 288 towards and into the handle 202. In some examples, the at least one elongated pull-arm 290 is attached to the pull-ring portion 288. In some examples, the at least one elongated pull-arm 290 is integrally formed with the pull-ring portion 288, together forming a unitary pull-member 286. In some examples, the pull-member 286 is a tube-cut pull-member, which can be formed by cutting (for example, laser cutting) a tubular member to form one or more elongated pull-arms 290.

[0175] The outer tube distal end portion 272 can be a portion of the outer bendable tube 270 which is devoid of slits 276, and the inner tube distal end portion 280 can be a portion of the inner bendable tube 278 which is devoid of slits 284. The pull-ring portion 288 is affixed, directly or indirectly, both to the outer tube distal end portion 272 and the inner tube distal end portion 280, such as by welding, soldering, gluing, and the like. In contrast, any elongated pullarm 290 of the pull-member 286 is disposed between an outer surface of the inner bendable tube 278 and an inner surface of the outer bendable tube 270 without being attached thereto, such that the elongated pull-arm 290 can axially slide within the space defined between the tubes 270 and 278 relative to the outer bendable tube 270 and / or the inner bendable tube 278.

[0176] In some examples, the distal portion of the steerable tube assembly 264 can include a distal tip portion 268 distal to the pull-ring portion 288 of the pull-member 286. The distal tip portion 268 can be configured to be relatively rigid and not sufficiently flexible to bend, to provide structural support to a component extendable through and out of the steerable tube assembly 264, such as the needle 212. The distal tip portion 268 can include a polymeric layer distal to the pull-ring portion 288 that is devoid of the outer tube slotted portion 274 and / or the inner tube slotted portion 282. The distal tip portion 268 can terminate at a distal atraumatic end, which can be optionally rounded and / or curved radially inwards, or can be otherwise formed to include an outer surface tapering in the distal direction.

[0177] The curvature of the steerable tube assembly 264, at least along a distal portion thereof, can be changed based on the operator manipulating the elongated pull-arm 290 via an actuator of the handle 202. The elongated pull-arm 290 can extend into the handle 202 and be coupled to a mechanism (not shown) controlled by a handle actuator, such as a knob 204 or any other type of actuator, which can be utilized to axially pull the elongated pull-arm 290 in a proximal direction.

[0178] When a proximally-oriented force is applied to the elongated pull-arm 290, the force is transmitted, via the pull-ring portion 288, to the outer tube distal end portion 272 and the inner tube distal end portion 280, resulting in circumferential slits 276 and 284 being narrowed or closed at the regions circumferentially aligned with the position of the axially pulled elongated pull-arm 290, bending the distal portion of the steerable tube assembly 264 in the direction of closure. When the proximally-oriented pull force is released, the distal portion of the steerable tube assembly 264 resumes its straightened (or less bent) configuration.

[0179] Resilience of the material of any of the outer bendable tube 270 and the inner bendable tube 278 can be configured to assist the steerable tube assembly 264 in returning to a straighter (or less bent) condition, when the elongated pull-arm 290 is released (i.e., no longer proximally pulled, or proximally pulled at a smaller pulling force). The shape of the slits and the material from which each of the tubes is made, such as Nitinol in some examples, can facilitate "spring- back" of the outer bendable tube 270 and / or inner bendable tube 278 to the pre-bent configuration. This can be advantageous because the elongated pull-arm 290 can be made of a relatively rigid material, such as metal (though other suitable materials are contemplated) that will not be compressed, thus avoiding kinks.

[0180] In contrast to a pull-wire utilized in conventional steerable shafts, having a circular cross-section, the elongated pull-arm 190 has a an arcuate flattened configuration, defining a thickness in the radial direction which is smaller than a diameter of a circular pull-wire configured to withstand similar pull-forces, which advantageously enables utilization of the steerable tube assembly 264 in low-profile implementations, without significantly increasing the diametric cross-sectional profile when disposed between the needle 212 and delivery catheter 206, for example.

[0181] A pull-member 286 can include any number of elongated pull-arms 290. In some examples, the pull-member 286 includes four elongated pull-arms 290 that can be circumferentially disposed at 90° from each other. In such an arrangement, the steerable tube assembly 264 can be controllably steered in two planes orthogonal to each other. In some examples, the pull-member 286 includes two elongated pull-arms 290 that can be circumferentially disposed at 180° from each other. In such an arrangement, the steerable tube assembly 264 can be controllably steered in two directions across a plane defined by the two elongated pull-arms 290. In some examples, the pull-member 286 includes a single elongated pull-arm 290 extending proximally from the pull-ring portion 288. In such an arrangement, the steerable tube assembly 264 can be bent in a single direction defined by the circumferential position of the elongated pull-arm 290.

[0182] A steerable tube assembly 264 disclosed herein can be optionally torqued in a desired rotational direction. Thus, even when a single pull-arm 290 is provided to allow bending in a single predefined direction, or two pull-arms 290 are provided across each other to enable bending in a single plane, rotation of the steerable tube assembly 264, can angularly orient the distal end of the steerable tube assembly 264, as well as any component extending therefrom, such as a needle 212, in a desired orientation.

[0183] In some examples, the steerable tube assembly 264 and the needle 212 are configured to be movable axially relative to each other in the proximal and distal directions. In some examples, the needle head 216 is not necessarily configured to be axially translatable relative to the steerable tube assembly 264, in which case it is positioned distal to the distal tip portion 268 at all times.

[0184] As shown in Figs. 10A-10B, a steerable tube assembly 264 can extend through the delivery catheter lumen 208. In some examples, the steerable tube assembly 264 is axially movable through, and relative to, the delivery catheter 206. As shown in Fig. 10B, when the steerable tube assembly 264 is bent, for example by proximally pulling a corresponding elongated pull-arm 290 thereof, the portion of the needle 212, extending through the articulating portion of the steerable tube assembly 264, is bent therewith. Thus, a steerable tube assembly 264 can be utilized to actively orient the needle 212 in a desired direction, such as towards a host leaflet 10.

[0185] For example, after advancement of the apparatus 200bthrough the patient’ s vasculature, when the distal end portion of apparatus 200blands at the target site, it may be initially positioned at a position that is different than the position of the desired host leaflet 10. If the delivery catheter 206 is a steerable catheter, it can be bent to navigate the distal portion of the apparatus 200btoward the desired host leaflet 10, such as a leaflet that can be closer to the left coronary ostium. In some cases, orienting the apparatus 200bsideways, towards a host leaflet 10, optionally in some proximity to the nadir of the leaflet, can orient the distal end of the apparatus 200btowards a host interior surface 14, which can be the interior surface of the aortic wall if the host valve is the native valve, or an interior surface of a frame of a previously implanted prosthetic valve serving as the host valve. In such cases, merely advancing the needle 212 in the distal direction to expose it prior to penetrating through the host leaflet 10, can direct the needle towards the interior surface of the host valvular structure 12 instead of the host leaflet 10 itself.

[0186] In order to properly orient the needle 212, a distal portion of the steerable tube assembly 264 can be exposed out of the delivery catheter 206 and bent, by pulling an appropriate elongated pull-arm 290 thereof as described above, advantageously orienting the distal tip portion 268 toward the host leaflet 10, such that during advancement of the needle 212, the needle head 216 can contact and pierce through the host leaflet 10, without posing a risk of contacting and damaging adjacent anatomical structures, such as the interior surface of the host valvular structure. Exposing the steerable tube assembly 264 out of the delivery catheter 206 can be accomplished by distally pushing the steerable tube assembly 264 relative to the deliverycatheter 206, by proximally pulling the delivery catheter 206 relative to the steerable tube assembly 264, or both. Subsequent stages of a method in which apparatus 200bis used can be similar to those described above with respect to Figs. 6A-6J. Further examples of steerable tube assemblies and methods for utilization thereof can be found, for example, in U.S. Provisional Application No. 63 / 583,915, which is incorporated herein by reference in its entirety.

[0187] While exemplary apparatuses 200 are described above for use in a method for forming a leaflet opening prior to implantation a guest prosthetic valve 100 inside a host valvular structure 12, it is to be understood that any exemplary apparatus 200 disclosed herein can be used to form a puncture or opening in any target tissue, including, but not limited to, a leaflet, in any other procedure that may not require utilization of an expansion member, such as a holedilating balloon 260, to further expand the opening, and may not involve procedural steps of guest prosthetic valve implantation.

[0188] Any of the apparatuses, devices, assemblies, etc. herein can be sterilized (for example, with heat, radiation, and / or chemicals, etc.) to ensure they are safe for use with patients, and any of the methods herein can include sterilization of the associated assembly, device, apparatus, etc. as one of the steps of the method. Examples of radiation for use in sterilization include, without limitation, gamma radiation and ultra-violet radiation. Examples of chemicals for use in sterilization include, without limitation, ethylene oxide and hydrogen peroxide. Some Examples of the Disclosed Technology

[0189] Some examples of above-described technology are enumerated below. It should be noted that one feature of an example in isolation or more than one feature of the example taken in combination and, optionally, in combination with one or more features of one or more examples below are examples also falling within the disclosure of this application.

[0190] Example 1. A tissue modification apparatus comprising: a needle comprising a needle head terminating at a needle tip; a dilation assembly extending through the needle, the dilation assembly comprising an expansion member movable between a compacted state and an expanded state; and wherein the needle and the dilation assembly are axially movable relative to each other.

[0191] Example 2. The apparatus of any example herein, particularly of example 1, further comprising a protective shaft disposed between the needle and the dilation assembly.

[0192] Example 3. The apparatus of any example herein, particularly of example 2, wherein the needle and the protective shaft are axially movable relative to each other.

[0193] Example 4. The apparatus of any example herein, particularly of example 2 or 3, wherein the protective shaft and the dilation assembly are axially movable with relative each other.

[0194] Example 5. The apparatus of any example herein, particularly of any one of examples 2 to 4, wherein the protective shaft comprises a plurality of shaft circumferential slits.

[0195] Example 6. The apparatus of any example herein, particularly of any one of examples 2 to 5, wherein the protective shaft comprises a shaft distal end portion terminating at a shaft distal edge.

[0196] Example 7. The apparatus of any example herein, particularly of example 6, wherein the shaft distal edge is atraumatic.

[0197] Example 8. The apparatus of any example herein, particularly of example 6 or 7, wherein the shaft distal edge is angled.

[0198] Example 9. The apparatus of any example herein, particularly of any one of examples 1 to 8, wherein the expansion member is a hole-dilating balloon mounted on a balloon catheter of the dilation assembly, wherein the compacted state of the expansion member is a deflated state of the hole-dilating balloon, and wherein the expanded state of the expansion member is an inflated state of the hole-dilating balloon.

[0199] Example 10. The apparatus of any example herein, particularly of example 9, wherein the dilation assembly further comprises a dilator attached to a dilator shaft extending proximally therefrom.

[0200] Example 11. The apparatus of any example herein, particularly of example 10, wherein the dilator comprises a dilator tapering portion.

[0201] Example 12. The apparatus of any example herein, particularly of example 10 or 11, wherein the dilator shaft extends through the balloon catheter.

[0202] Example 13. The apparatus of any example herein, particularly of any one of examples 10 to 12, wherein the hole-dilating balloon is attached at a proximal end thereof to the balloon catheter, and at a distal end of the hole-dilating balloon to the dilator.

[0203] Example 14. The apparatus of any example herein, particularly of any one of examples 1 to 13, wherein the needle further comprises a needle shaft proximally extending from the needle head.

[0204] Example 15. The apparatus of any example herein, particularly of example 14, wherein the needle shaft comprises a plurality of needle shaft circumferential slits.

[0205] Example 16. The apparatus of any example herein, particularly of example 15, wherein the needle shaft comprises a needle shaft distal portion comprising the plurality of needle shaft circumferential slits.

[0206] Example 17. The apparatus of any example herein, particularly of example 16, wherein the needle shaft further comprises a needle shaft proximal portion extending proximally from the needle shaft distal portion.

[0207] Example 18. The apparatus of any example herein, particularly of example 17, wherein the needle shaft proximal portion is devoid of circumferential slits.

[0208] Example 19. The apparatus of any example herein, particularly of example 17 or 18, wherein the proximal portion of the needle shaft comprises a polymeric material.

[0209] Example 20. The apparatus of any one of claims 1 to 19, wherein the needle head defines an angled surface terminating at the needle tip.

[0210] Example 21. The apparatus of any example herein, particularly of any one of examples 1 to 20, wherein the needle head comprises a plurality of head slits.

[0211] Example 22. The apparatus of any example herein, particularly of any one of examples 1 to 21, further comprising a delivery catheter, wherein the needle extends through a lumen of the delivery catheter.

[0212] Example 23. The apparatus of any example herein, particularly of example 22, wherein the delivery catheter terminates at an atraumatic delivery catheter distal end.

[0213] Example 24. The apparatus of any example herein, particularly of example 22 or 23, wherein the needle and the delivery catheter are axially movable relative to each other.

[0214] Example 25. The apparatus of any example herein, particularly of any one of examples 1 to 24, further comprising a steerable tube assembly defining a steerable assembly lumen through which the needle extends.

[0215] Example 26. The apparatus of any example herein, particularly of example 25, wherein the steerable tube assembly comprises: an inner bendable tube comprising an inner tube slotted portion and an inner tube distal end portion distal to the inner tube slotted portion; an outer bendable tube disposed around the bendable inner tube, the outer bendable tube comprising an outer tube slotted portion and an outer tube distal end portion distal to the inner tube slotted portion; and a pull-member comprising a pull-ring portion affixed to the inner tube distal end portion and to the outer tube distal end portion, and at least one elongated pull-arm extending proximally from the pull-ring portion; wherein the at least one elongated pull-arm is disposed between and is axially slidable relative to the inner tube and the outer tube; and wherein the atleast one elongated pull-arm is configured to bend the steerable tube assembly when the at least one elongated pull-arm is proximally pulled.

[0216] Example 27. The apparatus of any example herein, particularly of any one of examples 1 to 26, wherein the needle is configured to form a pilot puncture in a target tissue.

[0217] Example 28. The apparatus of claim 27, wherein the expansion member is configured to remain in the compacted state proximal to the needle head when the needle forms the pilot puncture.

[0218] Example 29. The apparatus of any example herein, particularly of example 27 or 28, wherein the expansion member is configured to be inserted within the pilot puncture.

[0219] Example 30. The apparatus of any example herein, particularly of example 29, wherein moving the expansion member to the expanded state, when positioned within the pilot puncture, is configured to expand the pilot puncture to form a tissue opening.

[0220] Example 31. The apparatus of any example herein, particularly of any one of examples 1 to 30, wherein the target tissue is a host leaflet of a host valvular structure, and wherein the tissue opening is a leaflet opening.

[0221] Example 32. The apparatus of any example herein, particularly of example 31, wherein the host valvular structure is a native valvular structure of a native heart valve.

[0222] Example 33. The apparatus of any example herein, particularly of example 31, wherein the host valvular structure is a valvular structure of previously implanted prosthetic valve that is implanted within a native heart valve.

[0223] Example 34. A method comprising: advancing a tissue modification apparatus to a target tissue over a guidewire, the tissue modification apparatus comprising a needle and a dilation assembly extending through the needle; and forming a pilot puncture through the target tissue by advancing a needle head of the needle against the target tissue, while maintaining an expansion member of the dilation assembly in a compacted state of the expansion member, proximal to the needle head.

[0224] Example 35. The method of any example herein, particularly of example 34, wherein the forming the pilot puncture comprises distally advancing the needle relative to the dilation assembly.

[0225] Example 36. The method of any example herein, particularly of example 34 or 35, wherein the advancing the tissue modification apparatus to the target tissue comprises maintaining the expansion member in the compacted state.

[0226] Example 37. The method of any example herein, particularly of any one of examples 34 to 36, wherein the advancing the tissue modification apparatus to the target tissue comprises maintaining the expansion member proximal to the needle head.

[0227] Example 38. The method of any example herein, particularly of any one of examples 34 to 37, wherein the needle head comprises an angled surface and terminates at a needle tip.

[0228] Example 39. The method of any example herein, particularly of example 38, wherein the forming the pilot puncture comprises piercing the target tissue by the needle tip.

[0229] Example 40. The method of any example herein, particularly of any one of examples 34 to 39, wherein the needle comprises a needle shaft extending proximally from the needle head, the needle shaft comprising a plurality of needle shaft circumferential slits.

[0230] Example 41. The method of any example herein, particularly of example 40, wherein the needle shaft comprises a needle shaft distal portion comprising the plurality of needle shaft circumferential slits.

[0231] Example 42. The method of any example herein, particularly of example 41, wherein the needle shaft further comprises a needle shaft proximal portion extending proximally from the needle shaft distal portion.

[0232] Example 43. The method of any example herein, particularly of example 42, wherein the needle shaft proximal portion is devoid of circumferential slits.

[0233] Example 44. The method of any example herein, particularly of example 41 or 42, wherein the proximal portion of the needle shaft comprises a polymeric material.

[0234] Example 45. The method of any example herein, particularly of any one of examples 34 to 44, wherein the needle head comprises a plurality of head slits.

[0235] Example 46. The method of any example herein, particularly of any one of examples 34 to 45, further comprising, after the forming the pilot puncture, positioning the expansion member, in its compacted state, inside the pilot puncture.

[0236] Example 47. The method of any example herein, particularly of example 46, wherein the dilation assembly further comprises a dilator distal to the expansion member, and a dilator shaft attached to the dilator and extending proximally therefrom.

[0237] Example 48. The method of claim 47, wherein the dilator comprises a tapering portion.

[0238] Example 49. The method of any example herein, particularly of example 47 or 48, wherein the advancing the tissue modification apparatus to the target tissue comprises advancing the tissue modification apparatus over the guidewire extending through a dilator lumen collectively defined by the dilator and the dilator shaft.

[0239] Example 50. The method of any example herein, particularly of any one of examples 47 to 49, wherein the positioning the expansion member inside the pilot puncture comprises passing the dilator through the pilot puncture.

[0240] Example 51. The method of any example herein, particularly of any one of examples 46 to 50, further comprising, after the positioning the expansion member inside the pilot puncture, expanding the expansion member inside the pilot puncture to dilate the pilot puncture and form a tissue opening within the target tissue.

[0241] Example 52. The method of claim 51 , wherein the expansion member is a hole-dilating balloon mounted on a balloon catheter of the dilation assembly, wherein the compacted state is a deflated state of the hole-dilating balloon, and wherein the expanding the expansion member comprises inflating the hole-dilating balloon.

[0242] Example 53. The method of any example herein, particularly of example 52, wherein the tissue modification apparatus further comprises a protective shaft disposed between the needle and the dilation assembly.

[0243] Example 54. The method of any example herein, particularly of example 53, wherein the protective shaft comprises a shaft distal end portion terminating at a shaft distal edge.

[0244] Example 55. The method of any example herein, particularly of example 54, wherein the shaft distal edge is atraumatic.

[0245] Example 56. The method of any example herein, particularly of example 54 or 55, wherein the shaft distal edge is angled.

[0246] Example 57. The method of any example herein, particularly of any one of examples 54 to 56, wherein the advancing the tissue modification apparatus to the target tissue comprises maintaining the hole-dilating balloon inside the protective shaft.

[0247] Example 58. The method of any example herein, particularly of any one of examples 54 to 56, wherein the advancing the tissue modification apparatus to the target tissue comprises maintaining the hole-dilating balloon proximal to the shaft distal edge.

[0248] Example 59. The method of any example herein, particularly of any one of examples 53 to 58, further comprising, before the positioning the hole-dilating balloon inside the pilot puncture, advancing the protective shaft towards the target tissue.

[0249] Example 60. The method of any example herein, particularly of example 59, wherein the advancing the protective shaft towards the target tissue comprises advancing the protective shaft relative to the needle.

[0250] Example 61. The method of any example herein, particularly of example 59 or 60, wherein the advancing the protective shaft towards the target tissue comprises advancing the protective shaft relative to the dilation assembly.

[0251] Example 62. The method of any example herein, particularly of any one of examples 59 to 61, wherein the advancing the protective shaft towards the target tissue comprises passing the protective shaft through the pilot puncture.

[0252] Example 63. The method of any example herein, particularly of example 62, wherein the passing the protective shaft through the pilot puncture comprises positioning the shaft distal edge distal to the needle head.

[0253] Example 64. The method of any example herein, particularly of any one of examples 59 to 63, further comprising, before the inflating the hole-dilating balloon, retracting the needle from the target tissue.

[0254] Example 65. The method of any example herein, particularly of example 64, wherein the retracting the needle comprises positioning the needle head proximal to the pilot puncture.

[0255] Example 66. The method of any example herein, particularly of example 64 or 65, wherein the retracting the needle comprises positioning the needle head proximal to the holedilating balloon.

[0256] Example 67. The method of any example herein, particularly of any one of examples 64 to 66, further comprising, after the retracting the needle and before the inflating the holedilating balloon, retracting the protective shaft.

[0257] Example 68. The method of any example herein, particularly of example 67, wherein the retracting the protective shaft comprises positioning the shaft distal edge proximal to the pilot puncture.

[0258] Example 69. The method of any example herein, particularly of example 67 or 68, wherein the retracting the protective shaft comprises positioning the shaft distal edge proximal to the hole-dilating balloon.

[0259] Example 70. The method of any example herein, particularly of any one of examples 52 to 69, further comprising, after the inflating the hole-dilating balloon, deflating the holedilating balloon.

[0260] Example 71. The method of any example herein, particularly of example 70, further comprising, after the deflating the hole-dilating balloon, retracting the hole-dilating balloon from the target tissue.

[0261] Example 72. The method of any example herein, particularly of example 51, further comprising, after the expanding the expansion member, compressing the expansion member back to the compacted state.

[0262] Example 73. The method of any example herein, particularly of example 72, further comprising, after the compressing the expansion member, retracting the expansion member from the target tissue.

[0263] Example 74. The method of any example herein, particularly of any one of examples 34 to 73, wherein the tissue modification apparatus further comprises a delivery catheter through which the needle extends.

[0264] Example 75. The method of any example herein, particularly of example 74, wherein the advancing the tissue modification apparatus to the target tissue comprises maintaining the needle head inside the delivery catheter.

[0265] Example 76. The method of any example herein, particularly of example 74 or 75, wherein the advancing the needle head against the target tissue comprises advancing the needle head relative to the delivery catheter.

[0266] Example 77. The method of any example herein, particularly of example 76, wherein the advancing the needle head relative to the delivery catheter comprises exposing the needle head out of the delivery catheter.

[0267] Example 78. The method of any example herein, particularly of any one of examples 34 to 77, wherein the tissue modification apparatus further comprises a steerable tube assembly defining a steerable assembly lumen through which the needle extends, wherein the steerable tube assembly comprises an inner bendable tube, an outer bendable tube disposed around the inner bendable tube, and a pull-member that comprises a pull-ring portion affixed to an inner tube distal end portion of the inner bendable tube and to an outer tube distal end portion of the outer bendable tube, and an elongated pull-arm extending proximally from the pull-ring portion and which is slidingly movable between and relative to the inner bendable tube and the outer bendable tube.

[0268] Example 79. The method of any example herein, particularly of example 78, further comprising, prior to the forming the pilot puncture, bending a distal portion of the steerable tube assembly by proximally pulling the elongated pull-arm.

[0269] Example 80. The method of any example herein, particularly of example 78 or 79, wherein the advancing the tissue modification apparatus to the target tissue comprises needle head inside the steerable assembly lumen.

[0270] Example 81. The method of any example herein, particularly of example 80, wherein the advancing the needle head against the target tissue comprises exposing the needle head out of the steerable assembly lumen.

[0271] Example 82. The method of any example herein, particularly of example 71 or 73, wherein the target tissue is a host leaflet of a host valvular structure, and wherein the tissue opening is a leaflet opening.

[0272] Example 83. The method of any example herein, particularly of example 82, further comprising, after the retracting the expansion member, positioning a guest prosthetic valve in a radially compressed state thereof within the host valvular structure, and radially expanding the guest prosthetic valve.

[0273] Example 84. The method of any example herein, particularly of example 83, wherein the positioning the guest prosthetic valve within the host valvular structure comprises positioning the guest prosthetic valve within the leaflet opening.

[0274] Example 85. The method of any example herein, particularly of example 84, wherein the positioning the guest prosthetic valve within the host valvular structure comprises positioning the guest prosthetic valve between host leaflets of the host valvular structures.

[0275] Example 86. The method of any example herein, particularly of any one of examples 83 to 85, wherein the radially expanding the guest prosthetic valve comprises inflating a valveexpanding balloon over which the guest prosthetic valve is disposed.

[0276] Example 87. The method of any example herein, particularly of any one of examples 83 to 85, wherein the radially expanding the guest prosthetic valve comprises actuating a mechanical actuator of the guest prosthetic valve.

[0277] Example 88. The method of any example herein, particularly of any one of examples 83 to 85, wherein the guest prosthetic valve is a self-expandable prosthetic valve, and wherein radially expanding the guest prosthetic valve comprises removing a restraint from around the guest prosthetic valve.

[0278] Example 89. The method of any example herein, particularly of any one of examples 82 to 88, wherein the host valvular structure is a native valvular structure of a native heart valve.

[0279] Example 90. The method of any example herein, particularly of any one of examples 82 to 88, wherein the host valvular structure is a valvular structure of previously implanted prosthetic valve that is implanted within a native heart valve.

[0280] Example 91. The method of any example herein, particularly of example 89 or 90, wherein the native heart valve is an aortic valve.

[0281] It is appreciated that certain features of the disclosure, which are, for clarity, described in the context of separate examples, may also be provided in combination in a single example. Conversely, various features of the disclosure, which are, for brevity, described in the context of a single example, may also be provided separately or in any suitable sub-combination or as suitable in any other described example of the disclosure. No feature described in the context of an example is to be considered an essential feature of that example, unless explicitly specified as such.

[0282] In view of the many possible examples to which the principles of the disclosure may be applied, it should be recognized that the illustrated examples are only preferred examples and should not be taken as limiting the scope. Rather, the scope is defined by the following claims. We therefore claim all that comes within the scope and spirit of these claims.

Claims

WE CLAIM:

1. A tissue modification apparatus comprising: a needle comprising a needle head terminating at a needle tip; a dilation assembly extending through the needle, the dilation assembly comprising an expansion member movable between a compacted state and an expanded state; and wherein the needle and the dilation assembly are axially movable relative to each other.

2. The apparatus of claim 1 , further comprising a protective shaft disposed between the needle and the dilation assembly.

3. The apparatus of any one of claims 1 to 2, wherein the expansion member is a holedilating balloon mounted on a balloon catheter of the dilation assembly, wherein the compacted state of the expansion member is a deflated state of the hole-dilating balloon, and wherein the expanded state of the expansion member is an inflated state of the holedilating balloon.

4. The apparatus of claim 3, wherein the dilation assembly further comprises a dilator attached to a dilator shaft extending proximally therefrom.

5. The apparatus of any one of claims 1 to 4, wherein the needle head comprises a plurality of head slits.

6. A method comprising: advancing a tissue modification apparatus to a target tissue over a guidewire, the tissue modification apparatus comprising a needle and a dilation assembly extending through the needle; and forming a pilot puncture through the target tissue by advancing a needle head of the needle against the target tissue, while maintaining an expansion member of the dilation assembly in a compacted state of the expansion member, proximal to the needle head.

7. The method of claim 6, further comprising, after the forming the pilot puncture, positioning the expansion member, in its compacted state, inside the pilot puncture.

8. The method of claim 7, wherein the dilation assembly further comprises a dilator distal to the expansion member, and a dilator shaft attached to the dilator and extending proximally therefrom.

9. The method of any one of claims 7 to 8, further comprising, after the positioning the expansion member inside the pilot puncture, expanding the expansion member inside thepilot puncture to dilate the pilot puncture and form a tissue opening within the target tissue.

10. The method of claim 9, wherein the expansion member is a hole-dilating balloon mounted on a balloon catheter of the dilation assembly, wherein the compacted state is a deflated state of the hole-dilating balloon, and wherein the expanding the expansion member comprises inflating the hole-dilating balloon.

11. The method of claim 10, wherein the tissue modification apparatus further comprises a protective shaft disposed between the needle and the dilation assembly.

12. The method of claim 11, further comprising, before the positioning the hole-dilating balloon inside the pilot puncture, advancing the protective shaft towards the target tissue.

13. The method of claim 12, wherein the advancing the protective shaft towards the target tissue comprises passing the protective shaft through the pilot puncture.

14. The method of any one of claims 12 to 13, further comprising, before the inflating the hole-dilating balloon, retracting the needle from the target tissue.

15. The method of claim 14, further comprising, after the retracting the needle and before the inflating the hole-dilating balloon, retracting the protective shaft.

16. The method of any one of claims 10 to 15, further comprising, after the inflating the holedilating balloon, deflating the hole-dilating balloon.

17. The method of claim 16, further comprising, after the deflating the hole-dilating balloon, retracting the hole-dilating balloon from the target tissue.

18. The method of claim 17, wherein the target tissue is a host leaflet of a host valvular structure, and wherein the tissue opening is a leaflet opening.

19. The method of claim 18, further comprising, after the retracting the expansion member, positioning a guest prosthetic valve in a radially compressed state thereof within the host valvular structure, and radially expanding the guest prosthetic valve.

20. The method of claim 19, wherein the radially expanding the guest prosthetic valve comprises inflating a valve-expanding balloon over which the guest prosthetic valve is disposed.

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