Braided anchor for mitral valve

Abstract

A prosthetic heart valve may include a valve portion, a tether connected to the valve portion, and an anchor for connecting the tether to the wall of the heart. The anchor may include a flexible first disc biased toward a first shape that is convex in a first direction and a neck extending from the first disc in a second direction opposite the first direction. The neck has a first end connected to the first disc and a second end. The anchor may further include a flexible second disc connected to the second end of the neck and biased toward a second shape that is convex in the first direction. When deployed, the first and second discs sandwich the wall of the heart.

Claims

1. A prosthetic heart valve, comprising: a valve portion including at least two leaflets; a tether having a first end connected to the valve portion and a second end; and a flexible anchor connected to the second end of the tether, the anchor comprising: a flexible first disc biased toward a first shape that is convex in a first direction; a flexible second disc connected to the first disc and biased toward a second shape; a neck extending from the first disc in a second direction opposite the first direction, the neck having a first end connected to the first disc and a second end; and a cuff securing the second disc to the tether; wherein the cuff includes one-way gripping features that permit the anchor to slide along the tether in the second direction, but do not allow the anchor to slide along the tether in the first direction.

2. The prosthetic heart valve of claim 1, wherein the first disc, the neck, and the second disc are formed from a flexible tube.

3. The prosthetic heart valve of claim 2, wherein the tube is formed of braided wire.

4. The prosthetic heart valve of claim 1, wherein the first disc and the second disc are formed of wire mesh.

5. The prosthetic heart valve of claim 4, wherein the wire mesh is constructed of a shape memory alloy.

6. The prosthetic heart valve of claim 1, wherein the first shape is a first dome shape and the second shape is a second dome shape that is convex in the first direction.

7. The prosthetic heart valve of claim 6, wherein the first dome shape has a concave interior, and the second dome shape extends into the concave interior.

8. The prosthetic heart valve of claim 1, further comprising a deformable frame supporting the first disc.

9. The prosthetic heart valve of claim 8, wherein the frame is invertible and is biased toward a shape that is convex in the first direction.

10. A method of anchoring the prosthetic heart valve of claim 1 to the heart of a patient, the method comprising: disposing the anchor within a delivery tube near a distal end of the delivery tube; locating the distal end of the delivery tube near or through a wall of the heart; and deploying the anchor from the delivery tube such that the first disc is positioned outside the heart wall and the second disc is positioned inside the heart wall.

11. The method of claim 10, further comprising inserting the delivery tube into the patient through a femoral vein.

12. The method of claim 10, further comprising passing the delivery tube through a septum of the heart.

13. The method of claim 10, wherein the step of deploying the anchor includes restraining movement of the anchor relative to the heart.

14. The method of claim 10, wherein the step of deploying the anchor includes pushing the anchor out of the distal end of the tube.

15. A prosthetic heart valve, comprising: a valve portion including at least two leaflets; a tether having a first end connected to the valve portion and a second end; and a flexible anchor connected to the second end of the tether, the anchor comprising: a flexible first disc biased toward a first shape that is convex in a first direction; a neck having a first end connected to the first disc and extending in a second direction opposite the first direction to a second end; a flexible second disc connected to the second end of the neck, the second disc being biased toward a second shape that is convex in the first direction, the first disc, the neck, and the second disc being formed from a contiguous tube of wire mesh; a deformable frame supporting the first disc, the frame being invertible and biased toward a cone shape; and an annular cuff securing the second disc to the tether.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is an exploded view of an exemplary prosthetic cardiovascular valve.

(2) FIG. 2 is an opened and flattened view of an unexpanded inner frame of the prosthetic valve of FIG. 1.

(3) FIGS. 3 and 4 are side and bottom views, respectively, of the inner frame of FIG. 2 in an expanded configuration.

(4) FIG. 5 is an opened and flattened view of an unexpanded outer frame of the prosthetic valve of FIG. 1.

(5) FIGS. 6 and 7 are side and top views, respectively, of the outer frame of FIG. 5 in an expanded configuration.

(6) FIGS. 8-10 are side, front, and top views, respectively, of an assembly of the inner frame of FIGS. 2-4 and the outer frame of FIGS. 5-7, all in an expanded configuration.

(7) FIG. 11A is a perspective view of an anchor for the prosthetic valve of FIG. 1.

(8) FIG. 11B is an axial view of the anchor of FIG. 11.

(9) FIG. 12 is a side view of the anchor for the prosthetic valve of FIG. 1 according to another arrangement.

(10) FIG. 13 is a perspective view of the anchor of FIG. 11 in a partially everted state.

(11) FIG. 14 illustrates a trans-jugular insertion of a delivery tube for the anchor of FIG. 11.

(12) FIG. 15 illustrates a trans-femoral insertion of the delivery tube of FIG. 14.

(13) FIG. 16 illustrates the delivery tube of FIGS. 14 and 15 extending through a wall of a heart.

(14) FIGS. 17-20 illustrate the anchor of FIG. 11 in progressive stages of deployment from the delivery tube of FIGS. 14 and 15.

(15) FIGS. 21A and 21B illustrate the delivery tube being retracted from the prosthetic valve of FIG. 1 and the anchor of FIG. 11.

(16) FIG. 22 illustrates the valve of FIG. 1 implanted in a heart.

(17) FIGS. 23A and 23B are perspective views of a frame for the anchor of FIG. 11.

(18) FIG. 24 is an axial view of the anchor of FIG. 11 with the frame of FIGS. 23A and 23B installed.

DETAILED DESCRIPTION

(19) As used herein, the term “proximal,” when used in connection with a delivery device or components of a delivery device, refers to the end of the device closer to the user of the device when the device is being used as intended. On the other hand, the term “distal,” when used in connection with a delivery device or components of a delivery device, refers to the end of the device farther away from the user when the device is being used as intended. As used herein, the terms “substantially,” “generally,” “approximately,” and “about” are intended to mean that slight deviations from absolute are included within the scope of the term so modified.

(20) An exemplary prosthetic heart valve 110 as may be used with various embodiments of the present disclosure is shown in an exploded view in FIG. 1. Valve 110 includes an inner structure or assembly 112 and an outer structure or assembly 114. Valve 110 may be coupled to a tether 226 and a collapsible tether anchor 210.

(21) Inner assembly 112 includes an inner frame 140, outer cylindrical wrap 152, and leaflet structure 136 (including articulating leaflets 138 that define a valve function). Leaflet structure 136 may be sewn to inner frame 140, and may use parts of inner frame 140 for this purpose. Inner assembly 112 is disposed and secured within outer assembly 114, as described in more detail below.

(22) Outer assembly 114 includes outer frame 170. Outer frame 170 may also have in various embodiments an outer frame cover of tissue or fabric (not pictured), or may be left without an outer cover to provide exposed wireframe to facilitate in-growth of tissue. Outer frame 170 may also have an articulating collar or cuff (not pictured) covered by a cover 148 of tissue or fabric.

(23) Tether 226 is connected to valve 110 by inner frame 140. Thus, inner frame 140 includes tether connecting or clamping portion 144 by which inner frame 140, and by extension valve 110, is coupled to tether 226.

(24) Inner frame 140 is shown in more detail in FIGS. 2-4. Inner frame 140 can be formed from a milled or laser-cut tube of a shape-memory material such as, for example, nitinol. Inner frame 140 is illustrated in FIG. 2 in an undeformed, initial state, i.e., as milled or laser-cut, but cut longitudinally and unrolled into a flat sheet for ease of illustration. Inner frame 140 is shown fully deformed, i.e., to the final, deployed configuration, in the side view and bottom view of FIGS. 3 and 4, respectively. Inner frame 140 can be divided into four portions corresponding to functionally different portions of inner frame 140 in final form: apex portion 141, body portion 142, strut portion 143, and tether connecting portion 144. Strut portion 143 includes six struts, such as strut 143A, which connect body portion 142 to connecting portion 144. A greater or lesser number of struts is contemplated herein.

(25) Connecting portion 144 includes longitudinal extensions of the struts, connected circumferentially to one another by pairs of micro-V's. Connecting portion 144 is configured to be radially collapsed by application of a compressive force, which causes the micro-V's to become more deeply V-shaped, with each pair of vertices moving closer together longitudinally and the open ends of the V shapes moving closer together circumferentially. When collapsed, connecting portion 144 can clamp or grip one end of tether 226, either connecting directly onto a tether line (e.g., braided filament line) or onto an intermediate structure, such as a polymer or metal piece that is, in turn, firmly fixed to the tether line. The foregoing is merely exemplary and other techniques can be used to connect tether 226 to connecting portion 144.

(26) In contrast to connecting portion 144, apex portion 141 and body portion 142 are configured to be expanded radially. Strut portion 143 forms a longitudinal connection, and radial transition, between the expanded body portion 142 and the compressed connecting portion 144.

(27) Body portion 142 includes six longitudinal posts, such as post 142A, although the body portion may include a greater or lesser number of such posts. The posts can be used to attach leaflet structure 136 to inner frame 140, and/or can be used to attach inner assembly 112 to outer assembly 114, such as by connecting inner frame 140 to outer frame 170. In the illustrated example, posts 142A include apertures 142B through which connecting members (such as suture filaments and/or wires) can be passed to couple the posts to other structures.

(28) Outer frame 170 of valve 110 is shown in more detail in FIGS. 5-7. Outer frame 170 can be formed from a milled or laser-cut tube of a shape-memory material such as, for example, nitinol. Outer frame 170 is illustrated in FIG. 5 in an undeformed, initial state, i.e., as milled or laser-cut, but cut longitudinally and unrolled into a flat sheet for ease of illustration. Outer frame 170 can be divided into a coupling portion 171, a body portion 172, and a flared portion 173, as shown in FIG. 5. Coupling portion 171 includes multiple openings or apertures 171A by which outer frame 170 can be coupled to inner frame 140, as discussed in more detail below.

(29) Flared portion 173 may include an indicator 174. In one example, indicator 174 is simply a broader portion of the wire frame element of flared portion 173, i.e., indicator 174 is more apparent in radiographic or other imaging modalities than the surrounding wireframe elements of flared portion 173. In other examples, indicator 174 can be any distinguishable feature (e.g., protrusion, notch, etc.) and/or indicia (e.g., lines, markings, tic marks, etc.) that enhance the visibility of the part of flared portion 173 on which it is formed, or to which it is attached. Indicator 174 can facilitate the implantation of the prosthetic valve by providing a reference point or landmark that the operator can use to orient and/or position the valve (or any portion of the valve) with respect to the native valve annulus or other heart structure. For example, during implantation, an operator can identify (e.g., using echocardiography) indicator 174 when the valve 110 is situated in a patient's heart. The operator can therefore determine the location and/or orientation of the valve and make adjustments accordingly.

(30) Outer frame 170 is shown fully deformed, i.e., to the final, deployed configuration, in the side view and top view of FIGS. 6 and 7, respectively. As best seen in FIG. 7, the lower end of coupling portion 171 forms a roughly circular opening (identified by “O” in FIG. 7). The diameter of this opening preferably corresponds approximately to the fully deformed diameter of body portion 142 of inner frame 140 to facilitate the coupling together of these two components of valve 110.

(31) Outer frame 170 and inner frame 140 are shown coupled together in FIGS. 8-10 in front, side, and top views, respectively. The two frames collectively form a structural support for a valve leaflet structure, such as leaflet structure 136 in FIG. 1. The frames support leaflet structure 136 in the desired relationship to the native valve annulus, support the coverings for the two frames to provide a barrier to blood leakage between the atrium and ventricle, and couple to the tether 226 (by the inner frame 140) to aid in holding the prosthetic valve in place in the native valve annulus by the connection of the free end of the tether and tether anchor 210 to the ventricle wall, as described more fully below. The two frames are connected at six coupling points (representative points are identified as “C”). In this embodiment, the coupling of the frames is implemented with a mechanical fastener, such as a short length of wire, passed through an aperture 171A in coupling portion 171 of outer frame 170 and a corresponding aperture 142B in a longitudinal post 142A in body portion 142 of inner frame 140. Inner frame 140 is thus disposed within the outer frame 170 and securely coupled to it.

(32) An exemplary anchor 210 for a prosthetic mitral heart valve is illustrated in FIGS. 11A and 11B. Anchor 210 includes a first disc 214 and a second disc 218, both provided by a wire mesh and centered on an axis X. First disc 214 is offset from second disc 218 in a first direction along axis X. First disc 214 and second disc 218 are each biased toward a dome-shaped resting configuration that is concave toward a second direction along axis X, the second direction being opposite the first direction. The resting configuration of first disc 214 extends far enough in the second direction along axis X to partially overlap second disc 218.

(33) It should be understood that the illustrated dome shapes are merely exemplary, and first disc 214 and second disc 218 may be biased differently. For example, either or both of first disc 214 and second disc 218 may be biased toward a resting configuration that is convex toward the second direction or generally planar. Further, the first disc 214 and second disc 218 may be biased to different resting configurations. In one example, the first disc 214 may be biased toward a dome-shaped resting configuration that is concave toward the second direction while the second disc 218 is biased toward a generally planar configuration having about the same diameter location as the widest part of the dome-shaped resting configuration of the first disk 214, as shown in FIG. 12. In the arrangement shown in FIG. 12, second disc 218 is generally planar in shape with a shallow concavity toward the first direction near the center of second disc 218.

(34) Anchor 210 also includes a cuff 222 for gripping a tether 226, which may be connected to a prosthetic heart valve. Cuff 222 is offset from second disc 218 in the second direction along axis X. One-way gripping features, such as angled teeth, within cuff 222 may permit anchor 210 to slide along tether 226 in the second direction, but not the first direction.

(35) Anchor 210 is flexible, as illustrated in FIG. 13, which shows anchor 210 with the first disc 214 everted from its resting configuration. First disc 214 is connected to second disc 218 by a neck 228 extending between first disc 214 and second disc 218. In the illustrated example, neck 228 is centered on axis X, but in other examples neck 228 may be radially offset from axis X. First disc 214, second disc 218, and neck 228 may all be constructed from a single continuous piece or tube of wire mesh. The wire mesh may be formed from a plurality of strands or wires braided into various three-dimensional shapes and/or geometries to engage tissues, or from one or more sheets cut to provide mesh, such as by laser. In one example, the wires form a braided metal fabric that is resilient, collapsible and capable of heat treatment to substantially set a desired shape. One class of materials which meets these qualifications is shape-memory alloys, such as nitinol. The wires may comprise various materials other than nitinol that have elastic and/or memory properties, such as spring stainless steel, trade named alloys such as Elgiloy® and Hastelloy®, CoCrNi alloys (e.g., tradename Phynox®), MP35N®, CoCrMo alloys, or a mixture of metal and polymer fibers. Depending on the individual material selected, the strand diameter, number of strands, and pitch may be altered to achieve the desired shape and properties of anchor 210. Shape memory materials such as nitinol may be particularly suitable for anchor 210 in that shape memory material construction enables anchor 210 to consistently return to an intended shape after being compressed and deployed. In other arrangements, anchor 210 may be covered by or may incorporate other flexible biocompatible material, such as a fabric.

(36) FIG. 14 shows a trans-jugular insertion of an at least partially flexible delivery tube 230 for anchor 210 and valve 110. Delivery tube 230 may be formed of any known material for building catheters, including biocompatible metals such as steel, and may be part of a steerable or flexible catheter system. Delivery tube 230 may include an inflexible portion near its distal end to facilitate the intended puncture of tissue and guidance of valve 110. Delivery tube 230 is inserted through the patient's jugular vein (not shown), then through superior vena cava 236, right atrium 252, atrial septum 254, left atrium 256, native mitral valve 260, and into left ventricle 242. Tube 230 exits left ventricle 242 through ventricular wall 238 at or near the apex 246 of heart 234. A retractable puncturing device (not shown) and a retractable atraumatic tip (not shown) may extend from the distal open end 248 of tube 230 in alternate stages of insertion of tube 230. The puncturing device may produce openings through atrial septum 254 and ventricular wall 238 while the atraumatic tip may act to prevent injury to other tissue. Once delivery tube 230 has been fully inserted, the distal open end 248 of tube 230 is positioned outside of ventricular wall 238. The trans-jugular insertion of tube 230 may be accomplished by any of variety of methods, such as, for example, guiding tube 230 along a guide wire, such as a shape-memory guide wire, inserted through the jugular vein. The flexible nature of anchor 210 allows trans-jugular delivery of anchor 210 through tube 230. Because tube 230, anchor 210, and valve 110 all reach heart 234 from the jugular vein, valve 110 and anchor 210 may be delivered and implanted without any intercostal puncture.

(37) FIG. 15 shows a trans-femoral insertion of tube 230. Tube 230 enters heart 234 through inferior vena cava 250, travels through right atrium 252, and punctures septum 254 to enter left atrium 256. Tube 230 is advanced from left atrium 256 through native mitral valve 260, left ventricle 242, and ventricular wall 238 such that the open end 248 of the tube is positioned outside of wall 238 at or near apex 246. As with trans-jugular insertion, guidance of tube 230 during trans-femoral insertion may be accomplished using a variety of methods, including guidance along a guide wire.

(38) The trans-jugular and trans-femoral insertions described above are merely exemplary. It should be understood that tube 230 could be guided toward heart 234 using any suitable method known in the art.

(39) FIGS. 16-20 illustrate anchor 210 in progressive stages of deployment from the open end 248 of tube 230. Tube 230 is shown in a distalmost position in FIG. 16, with open end 248 positioned outside of heart 238. Tube 230 may be retracted while anchor 210 is forced to remain in place, such as by a reversal of a typical Bowden cable arrangement. For example, a semi-rigid cable or wire 266 may be inserted through tube 230 to contact the proximal end of valve 110, as shown in FIG. 21A. Pulling tube 230 proximally relative to wire 266 causes valve 110 and anchor 210 to deploy out from the open end 248 of tube 230, as shown in 21B. As shown in FIG. 17, retracting tube 230 while preventing anchor 210 from retreating with the tube into heart 234 causes first disc 214 of anchor 210 to deploy out from the open end 248 of tube 230 and expand radially relative to axis X. Upon further retraction of tube 230, the bias of first disc 214 causes it to curve back onto the outer apex 246 of heart 234, as shown in FIG. 18. Further retraction of tube 230 in FIG. 19 allows second disc 218 to deploy and expand radially relative to axis X within left ventricle 242 until second disc 218 opens to press against an inner side of wall 238, as shown in FIG. 20. Pressure against wall 238 results from the elastic bias of first disc 214 and second disc 218 toward certain resting positions as described above with regard to FIGS. 11A, 11B, and 12. First disc 214 and second disc 218 pressing on opposite sides of wall 238 causes anchor 210 to grip wall 238. Such progressive expansion from within a narrow tube results in anchor 210 adequately securing valve 110 to ventricular wall 238 without requiring an intercostal puncture through the patient's chest.

(40) According to alternative embodiments or arrangements, tube 230 may be retracted while anchor 210 is held in place by a cord (not shown) connected to anchor 210 and extending out from an intercostal incision in the patient's chest. In an embodiment employing this method, tube 230 may extend into left ventricle 242 but not entirely or at all through ventricular wall 238, and anchor 210 may be deployed by pulling anchor 210 out of tube 230 and through wall 238 using the cord.

(41) FIG. 22 illustrates valve 110 implanted in heart 234 with anchor 210 seated at or near the apex 246 of heart 234. Tube 230 has been withdrawn from heart 234, through inferior vena cava 250 in the illustrated example, leaving valve 110 behind.

(42) FIGS. 23A and 23B illustrate a flexible reinforcing frame 258 for anchor 210. Frame 258 optionally may be installed as illustrated to reinforce anchor 210. Frame 258 is constructed from wire that is both thicker and less flexible than the wire mesh of anchor 210 (or simply less flexible), but frame 258 may be constructed from any suitable elastically deformable biocompatible material, such as nitinol. Frame 258 tends toward a resting configuration in which leaves 264 of frame 258 are arranged to form a cone shape. Frame 258 may be inverted from the cone shape, but will return to the cone shape upon release from external forces.

(43) FIG. 24 shows frame 258 installed on anchor 210. Frame 258 is disposed over first disc 214, on a side of first disc 214 opposite second disc 218. Tabs 262 extend from frame 258 axially through the neck 228 of anchor 210 and are bound to tether 226 by cuff 222. In such an arrangement, frame 258 would be inverted and compressed radially inward so as to extend in the first direction relative to anchor 210 when anchor 210 is compressed within tube 230. For example, first disc 214 and frame 258 may be inverted to extend in the first direction along axis X within tube 230 prior to delivery. Frame 258 will fold back toward the second direction and into the cone shape after release from tube 230. Frame 258 further includes tabs 262 that, in the rest configuration of frame 258, extend into an interior of the cone shape from a point at which leaves 264 intersect. As anchor 210 is deployed, frame 258 expands radially outward and folds backward toward the second direction and ventricular wall 238 to push first disc 214 onto wall 238. Tabs 262 may extend into cuff 222, and frame 258 may be connected to anchor 210 by cuff 222 gripping tabs 262.

(44) To summarize the foregoing, disclosed is an anchor for a prosthetic heart valve, including a flexible first disc biased toward a first shape that is convex in a first direction; a neck extending from the first disc in a second direction opposite the first direction, the neck having a first end connected to the first disc and a second end; and a flexible second disc connected to the second end of the neck and biased toward a second shape; and/or

(45) the first disc, the neck, and the second disc may be formed from a flexible tube; and/or

(46) the tube may be formed of braided wire; and/or

(47) the first disc and the second disc may be formed of wire mesh; and/or

(48) the wire mesh may be constructed of a shape memory alloy; and/or

(49) the anchor may further include an annular cuff connected to the second disc and configured to secure the anchor to a tether; and/or

(50) the cuff may include gripping features that restrict movement of the tether within the cuff in the second direction and permit movement of the tether within the cuff in the first direction; and/or

(51) the first shape may be a first dome shape and the second shape may be a second dome shape that is convex in the first direction; and/or

(52) the first dome shape may have a concave interior, and the second dome shape may extend into the concave interior; and/or

(53) the anchor may further include a deformable frame supporting the first disc; and/or the frame may be invertible and may be biased toward a cone shape.

(54) Also disclosed is a prosthetic heart valve, including a valve portion including at least two leaflets; a tether having a first end connected to the valve portion and a second end; and a flexible anchor connected to the second end of the tether, the anchor including a flexible first disc biased toward a first shape that is convex in a first direction; a flexible second disc connected to the first disc and biased toward a second shape; and a cuff securing the second disc to the tether; and/or

(55) the cuff may include gripping features that restrict movement of the tether within the cuff in the second direction and permit movement of the tether within the cuff in the first direction. Also disclosed is a method of anchoring any of the prosthetic heart valves described above to the heart of a patient, the method including disposing the anchor within a delivery tube near a distal end of the delivery tube; passing the distal end of the delivery tube at least partially through a wall of the heart; and deploying the anchor from the delivery tube such that the first disc is positioned outside the heart wall and the second disc is positioned inside the heart wall; and/or
the method may further include inserting the delivery tube into the patient through a femoral vein; and/or
the method may further include passing the delivery tube through a septum of the heart; and/or the step of deploying the anchor may include restraining movement of the anchor relative to the heart; and/or
the step of deploying the anchor may include pushing the anchor out of the distal end of the tube.

(56) Also disclosed is a prosthetic heart valve, including a valve portion including at least two leaflets; a tether having a first end connected to the valve portion and a second end; and a flexible anchor connected to the second end of the tether, the anchor including a flexible first disc biased toward a first shape that is convex in a first direction; a neck having a first end connected to the first disc and extending in a second direction opposite the first direction to a second end; a flexible second disc connected to the second end of the neck, the second disc being biased toward a second shape that is convex in the first direction, the first disc, the neck, and the second disc being formed from a contiguous tube of wire mesh; a deformable frame supporting the first disc, the frame being invertible and biased toward a cone shape; and an annular cuff securing the second disc to the tether.

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