Method and apparatus for mitral valve chordae repair

Abstract

To provide methods and devices for transvascular prosthetic chordae tendineae implantation.SOLUTION: Methods and devices for transvascular prosthetic chordae tendineae implantation are disclosed. A catheter is advanced into the left atrium. From an atrium side, the catheter can be anchored to a superior surface of a mitral valve leaflet, and a leaflet anchor can be advanced into the mitral valve leaflet to secure the mitral valve leaflet to a leaflet suture. A ventricular anchor is anchored to the wall of the ventricle to secure the ventricular wall to a ventricle suture. The leaflet suture and the ventricle suture may be tensioned and connected by a suture lock to form a prosthetic chordae tendineae.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims the benefit under 35 U.S.C. § 119(e) of U.S. Provisional Application No. 62 / 641,612, filed March 12, 2018, the entirety of which is incorporated herein by reference for all purposes. This application is also a continuation-in-part of U.S. patent application Ser. No. 15 / 858,671, filed December 29, 2017, which is a continuation-in-part of U.S. patent application Ser. No. 15 / 638,176, filed June 29, 2017, now U.S. Patent No. 9,877,833, the entirety of which claims priority to U.S. Provisional Application No. 62 / 441,031, filed December 30, 2016, the entirety of each of which is incorporated herein by reference for all purposes. All applications with foreign or domestic priority claims identified in the Application Data Sheet filed herewith are incorporated herein by reference under 37 CFR § 1.57.

[0002] The present disclosure relates to mitral valve repair or replacement, and more generally to methods and devices for reshaping, repairing and / or replacing mitral valve chordae to restore proper function of the mitral valve from conditions of mitral regurgitation. [Background technology]

[0003] The heart has four heart valves that allow blood to pass in one direction through the four chambers of the heart: the tricuspid valve, the mitral valve, the pulmonary valve, and the aortic valve. The four chambers are the left and right atria (upper chambers) and the left and right ventricles (lower chambers).

[0004] The mitral valve is made up of two leaflets, called the anterior and posterior leaflets, which open and close in response to pressure exerted on the leaflets by the pumping of the heart. Several problems can occur or develop with the mitral valve. These problems include mitral regurgitation (MR), in which the mitral valve leaflets do not close properly, causing the mitral valve to leak. Severe mitral regurgitation can adversely affect cardiac function and impair a patient's quality of life and lifespan.

[0005] Several techniques have been developed to correct mitral regurgitation, including heart transplantation, valve replacement or repair, chordae tendineae shortening or replacement, and mitral annulus repair, also known as annuloplasty, depending on the disease and underlying etiology.

[0006] Certain surgical and transapical approaches have been proposed for chordae replacement or repair. However, despite these efforts, there remains a need for transvascular approaches for chordae replacement or repair to reduce or eliminate MR. Summary of the Invention [Means for solving the problem]

[0007] Aspects of the invention include a method for implanting transvascular artificial chordae, comprising: advancing a catheter into the left atrium and through the mitral valve into the left ventricle; deploying a ventricular anchor from the catheter into the wall of the left ventricle, leaving ventricular sutures attached to the ventricular anchor and extending proximally through the catheter; advancing the leaflet anchor through the catheter from the atrial side through the superior surface of the mitral valve leaflet, positioning the leaflet anchor against the inferior (ventricular) side of the leaflet with the leaflet sutures extending proximally through the leaflet; and securing the leaflet sutures from the apex of the leaflet to the ventricular sutures to limit the range of movement of the leaflet toward the left atrium.

[0008] Another aspect of the present disclosure is a leaflet anchor deployment system that includes a catheter having a proximal end and a distal end, a leaflet anchor disposed at the distal end of the catheter, and a needle advanceable through the leaflet anchor, the needle releasably carrying a pre-loaded radially expandable leaflet anchor having a suture extending proximally through the catheter.

[0009] According to another aspect of the present invention, there is provided a method for implanting transvascular artificial chordae, comprising the steps of advancing a catheter into the left atrium, advancing it through the mitral valve and into the left ventricle, deploying a ventricular anchor from the catheter into the wall of the left ventricle and leaving ventricular sutures attached to the ventricular anchor and extending proximally through the catheter, and securing a leaflet anchor catheter to the mitral valve leaflet from the atrial side, advancing a leaflet anchor from the catheter through the mitral valve leaflet with the leaflet anchor catheter secured to the leaflet, securing the mitral valve leaflet to the leaflet sutures extending proximally through the catheter, and securing the leaflet sutures to the ventricular sutures to limit the range of movement of the leaflet toward the left atrium.

[0010] Advancing the leaflet anchor from the catheter through the mitral valve leaflet to secure the mitral valve leaflet can include advancing a needle pre-loaded with the leaflet anchor through a superior surface of the mitral valve leaflet. Securing the leaflet anchor catheter to the mitral valve leaflet can include using a leaflet connector. The leaflet connector can include a helical anchor or a tissue hook.

[0011] According to another aspect of the present invention, a method of securing a leaflet anchor to a mitral valve leaflet is provided, the method including the steps of advancing a catheter into the left atrium, securing a leaflet connector coupled to the catheter to the mitral valve leaflet from the atrial side of the leaflet, and, after securing the leaflet connector to the mitral valve leaflet, advancing a leaflet anchor through the mitral valve leaflet to secure the mitral valve leaflet to the leaflet sutures.

[0012] Advancing the leaflet anchor through the mitral valve leaflet to secure the mitral valve leaflet to the leaflet suture can include advancing a needle pre-loaded with the leaflet anchor through the mitral valve leaflet from the atrial side. The needle can also be advanced from a leaflet connector. The leaflet connector can include a helical anchor.

[0013] According to another aspect of the present invention, a leaflet anchor deployment system is provided, the system including a catheter having a proximal end and a distal end, a leaflet connector disposed at the distal end of the catheter, and a needle advanceable through the leaflet connector, the needle including a radially expandable leaflet anchor having a suture preloaded thereon and extending proximally through the catheter. The leaflet connector may include a helical anchor.

[0014] According to another aspect of the present invention, there is provided a neochordae tendineae deployment system including a catheter having a proximal end and a distal end, an expandable helical ventricular anchor subassembly through the catheter and having a ventricular suture extending proximally therethrough, and a leaflet anchor deployment subassembly extending through the catheter, the leaflet anchor deployment subassembly having a radially expandable leaflet anchor therein and the leaflet suture extending proximally therethrough.

[0015] The radially expandable leaflet anchor can include a pledget. The pledget can be convertible from an elongated strip shape to a radially expanded, axially retracted shape by proximal retraction of the suture. The radially expandable leaflet anchor can include leaflet sutures disposed between two sheets of material. The radially expandable leaflet anchor can be carried within a needle having a sharp tip for piercing the leaflet. The leaflet anchor deployment subassembly can include an elongated tube having a distal end and a central lumen, and a leaflet connector on the distal end. The leaflet connector can include a helical leaflet anchor. The needle can move axially relative to the helical leaflet anchor. The system can further include a suture lock subassembly advanceable through the catheter and configured to connect the ventricular suture to the leaflet suture.

[0016] According to another aspect of the present invention, a leaflet anchor delivery subsystem is provided, the subsystem including an elongate flexible tubular body having a proximal end, a distal end and a central lumen, a deployment needle axially movably advanceable through the central lumen, a leaflet anchor carried within the deployment needle, and a leaflet connector carried by the distal end of the tubular body. The leaflet anchor may include a helical element. The deployment needle may be axially extendable through the helical element.

[0017] According to another aspect of the present invention, a tissue anchor is provided that includes a hub, a suture extending proximally from the hub, a helical anchor extending distally from the hub, and a core wire extending concentrically through the helical anchor and beyond a distal end of the helical anchor.

[0018] The tissue anchor may further include a suture anchor guide extending proximally from the hub. The tissue anchor may further include a tubular sleeve extending proximally from the hub and having a length of about 10 cm or less. The tissue anchor may further include a radiopaque marker carried by the sleeve. The tissue anchor may further include a radiopaque marker axially movably carried by the core wire. The tissue anchor may further include a spring carried by the core wire. The tissue anchor may further include a tissue piercing point on a distal end of the helical anchor and barbs on the helical anchor configured to resist rotation of the helical anchor out of engagement with the tissue.

[0019] In accordance with another aspect of the present invention, there is provided a tissue anchor having a dynamic depth indicator, the tissue anchor including a hub, a tissue anchor extending distally from the hub, a core wire extending distally from the hub, a radiopaque marker movably carried by the hub, and a spring biasing the radiopaque marker distally, the radiopaque marker advancing proximally relative to the tissue anchor in response to advancement of the tissue anchor into tissue.

[0020] In accordance with another aspect of the present invention, an endovascular suture lock is provided that includes a body having a suture pathway extending therethrough, a movable wall within a housing for reducing a cross-sectional dimension of the suture pathway, a rotatable coupling on the housing, and a drive mechanism for advancing the movable wall in response to rotation of the coupling.

[0021] The suture lock can further include a friction-enhanced surface exposed to the suture pathway. The friction-enhanced surface can be on the movable wall. The suture lock can include a push wedge having an angled surface and axially movable within the housing. Rotation of the coupling can axially advance the push wedge, which laterally advances the movable wall to change the cross-sectional dimension of the suture pathway. The movable wall can include a suture-gripping surface on a first side and an angled surface on a second side, the angled surface configured for sliding contact with the angled surface on the push wedge. [Brief explanation of the drawings]

[0022] The foregoing and other features of the present disclosure will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings, which should be understood to depict only some embodiments in accordance with the disclosure and are not to be considered limiting in scope.

[0023] [Figure 1] Figure 1 shows the placement of the ventricular anchor via a transcephalic approach to the mitral valve. [Figure 2A] FIG. 2A shows a ventricular anchor. [Figure 2B] FIG. 2B shows the ventricular anchor. [Figure 2C] FIG. 2C is a perspective view of a ventricular anchor on the distal end of a ventricular anchor deployment tool. [Figure 2D] FIG. 2D is a perspective view of the proximal end of the ventricular anchor deployment tool. [Figure 2E] FIG. 2E is a partially exploded perspective view of the ventricular anchor and the distal end of the ventricular anchor deployment tool. [Figure 3] FIG. 3 shows the deployment end of the catheter positioned to engage the leaflets of the mitral valve. [Figure 4] Figure 4 shows the leaflet captured by the helical leaflet anchor and the needle passing across the leaflet from the atrium to the ventricle. [Figure 5] FIG. 5 shows a pledget-style leaflet anchor deployed from a needle into the ventricle. [Figure 6A] FIG. 6A shows proximal traction on the leaflet sutures to fold the pledget against the ventricular side of the leaflet. [Figure 6B] FIG. 6B shows details of the pledget-type leaflet anchor. [Figure 6C] FIG. 6C shows details of the pledget-type leaflet anchor. [Figure 6D] FIG. 6D shows details of the pledget-type leaflet anchor. [Figure 7] FIG. 7 shows the deployed leaflet anchors and sutures, as well as the deployed ventricular anchor and sutures ready for tensioning and attachment of the suture lock. [Figure 8] FIG. 8 shows a perspective view of the distal end of the leaflet anchor delivery subsystem. [Figure 9] FIG. 9 shows a perspective view of the proximal end of the leaflet anchor delivery subsystem. [Figure 10] FIG. 10 shows an exploded view of the distal end of the leaflet anchor delivery subsystem. [Figure 11] FIG. 11 shows the advancement of a suture lock through the suture lock delivery subsystem over the leaflet anchor sutures and the ventricular anchor sutures, connecting the leaflet anchor to the ventricular anchor. [Figure 12] FIG. 12 shows the suture lock in the locked position after the tension has been adjusted and the suture ends have been cut. [Figure 13] FIG. 13 shows a perspective view of the distal end of the suture lock delivery subsystem. [Figure 14] FIG. 14 shows a perspective view of the proximal end of the suture lock delivery subsystem. [Figure 15] FIG. 15 shows a partially exploded view of the distal end of the suture lock delivery subsystem. [Figure 16] FIG. 16 shows a perspective view of the distal end of the suture cutting assembly. [Figure 17]FIG. 17 shows a side view of the cutting assembly portion of the suture lock delivery subsystem in a configuration in which the cutting head has not yet advanced to hold the suture before it is cut. [Figure 18] FIG. 18 shows a side view of the cutting assembly portion of the suture lock delivery subsystem in a configuration in which the cutting head is advanced to cut the suture. [Figure 19] FIG. 19 shows a side view of a suture lock and a distal end of a torque drive configured to couple to the suture lock. [Figure 20] FIG. 20 shows a view of the proximal end of the suture lock. [Figure 21] FIG. 21 shows a view of the distal end of the suture lock. DETAILED DESCRIPTION OF THE INVENTION

[0024] U.S. Patent Application No. 15 / 858,671, filed December 29, 2017, which is incorporated herein by reference in its entirety, discloses a system and method for transvascular artificial chordae implantation. One embodiment includes advancing a catheter into the left atrium, advancing it through the mitral valve into the left ventricle, deploying a ventricular anchor from the catheter and deploying it within the wall of the left ventricle, leaving ventricular sutures attached to the ventricular anchor and extending proximally through the catheter, advancing the leaflet anchor into the mitral valve leaflet to secure the mitral valve leaflet to the leaflet suture extending proximally through the catheter, extending the leaflet suture onto the superior surface of the leaflet tip, and securing the leaflet suture to the ventricular suture to limit the range of movement of the leaflet toward the left atrium. Specific embodiments are further described herein.

[0025] Approaching the mitral valve can be accomplished via a standard transseptal approach, which provides access to the left atrium. With this access, the first step is to secure the leaflet capture catheter to the mitral valve leaflets in a position determined to best correct regurgitation. Inspecting the leaflet surface from the superior atrial surface can advantageously provide immediate feedback regarding the optimal location for adding the mitral valve chordae. In another implementation of the present invention, the ventricular anchor is deployed first, followed by the leaflet anchors.

[0026] Referring to FIG. 1 , a ventricular anchor, such as helical anchor 32, is deployed near the apex 20 of the left ventricle 24. In the following figures, helical anchor 32 is shown positioned near the apex 20; however, anchor 32 can also be attached at a location offset from the thin tissue of the apex or embedded in the generally thicker adjacent wall of the ventricle, such as between two papillary muscles. This aligns the implanted neochordae construct (sutures, any neopapillary muscles, and / or helical anchor) along an axis substantially parallel or concentric with the original path of the native chordae. In certain embodiments, the implanted neochordae construct is aligned along a longitudinal axis within 5 degrees, 10 degrees, or 15 degrees of a line parallel to the original path of the native chordae and / or a path adjacent to the original path of the native chordae. Additionally, while a helical anchor is illustrated, the anchor may have different structures for engaging cardiac tissue, and thus other tissue anchor structures may be used in place of the helical structure, including various piercing, hook, or radially expandable structures known for engaging tissue.

[0027] 2A and 2B, one embodiment of a tissue anchor suitable for use as a ventricular anchor in accordance with the present invention is shown. While anchor assembly 50 is described primarily in the context of chordae tendineae repair applications herein, the anchor may be utilized in any of a wide variety of other applications where a soft tissue or bone anchor may be desired.

[0028] Anchor assembly 50 generally includes a coil 54, which may comprise any of a variety of materials, such as stainless steel or nitinol. Coil 54 extends helically between a proximal end 56 and a distal end 58. Distal end 58 includes a sharpened tip 59 and also carries retention barbs 61 configured to resist back-rotation and peeling of the coil from tissue. Proximal end 56 of coil 54 is carried by (attached to or integrally formed with) hub 57, which will be discussed in more detail below.

[0029] Extending distally from the hub 57 and within the coil 54 is an elongated core wire 62 having a sharp, tissue-piercing distal tip 64. The distal tip 64 is located distal to the distal end 58 of the coil 54. This allows the sharp distal tip 64 to pierce tissue upon contact and before initiating rotation of the coil 54 to embed the coil 54 within the target tissue. Engaging the tip 64 prior to rotating the anchor stabilizes the anchor against lateral movement and holds the anchor 50 in place relative to the tissue, allowing the coil 54 to be rotated to engage tissue without "wobbling" the anchor from the desired target site, as will be understood by those skilled in the art. The proximal end of the core wire 62 can be attached to the hub in a variety of ways, such as by soldering, brazing, adhesive, and / or mechanical interference, such as by inserting into an opening in a sidewall or other surface of the hub 57.

[0030] A radiopaque depth marker 66 having an opening 68 is carried axially movably on the core wire 62. A distal stop 70, such as a radially outwardly extending projection or annular protrusion, is carried by the core wire 62 and is spaced proximally from the sharpened distal end 64, providing a core wire guidance segment 72 distal to the stop 70 so that the marker 66 does not impair the tissue anchoring function of the distal tip 64. The stop 70 functions to limit distal movement of the marker 66. The marker 66 may be an annular structure, such as a circular disk, having a central opening for receiving the core wire 62.

[0031] The coil spring 71 is carried concentrically on the core wire 62, urging the radiopaque marker 66 distally. The radiopaque marker 66 is thus held in position against the proximal side of the stop 70. In use, the marker 66 rides on the tissue surface at the target attachment site. As the helical coil anchor 54 rotates and advances distally into the tissue, the marker 66 rides proximally on the core wire 62 with the tissue surface, compressing the coil spring 71 until the tissue anchor is fully embedded and the marker 66 retracts proximally toward the hub. This allows fluoroscopic visualization of the progression of the coil into the tissue and the fully engaged endpoint of the coil 54 implanted within the target tissue by observing the changing distance between the marker 66 and a reference, such as the hub 57 or other radiopaque marker.

[0032] The hub 57 includes a proximal connector for engagement with a rotary drive, as discussed elsewhere herein. In one embodiment, the connector includes an opening, such as a hexagonal opening, for releasably engaging a complementary surface structure on the distal end of the drive. A suture 74 is secured to the anchor assembly 50, e.g., the hub 57, the coil 54, or the core wire 62. In the illustrated embodiment, the suture 74 is attached to a cross pin 76 that is inserted through one or two openings in the hub sidewalls and across the central hub lumen. The suture can additionally carry one or more radiopaque markers 82 at a location distal to the hub 57 and can extend proximally through the proximal connector and central lumen of the rotary drive.

[0033] A suture lock guide, such as a tubular sleeve 78, extends proximally from the hub 57 at least about 2 mm, 4 mm, or 8 mm, but typically no more than about 5 cm or 2 cm, depending on the desired performance. The guide sleeve 78 may comprise a flexible material, such as ePTFE. Preferably, a radiopaque marker band 80 is carried by the proximal end of the sleeve 78 and positioned axially spaced from the markers 82 on the suture 74 to facilitate fluoroscopic visualization of the suture lock as it is advanced distally over the suture 74. The marker band 80 may be positioned between the inner and outer layers of the ePTFE sleeve by placing the band over the sleeve and inverting the sleeve over it to encase the ring.

[0034] The suture lock guide may include any of a variety of structures, such as a sleeve as shown, or an alignment pin extending proximally from the hub and received within a lumen within the suture lock, to maintain the orientation of the suture lock after detachment from the deployment catheter. Because suture tension is optimized while the suture lock is held in place by the deployment catheter, any change in the orientation of the suture lock after release from the catheter can affect the tension on the valve leaflets and potentially negatively impact the therapeutic value of the implant. The suture lock guide helps maintain a constant maximum distance between the ventricular anchor and the leaflet anchors both before and after deployment from the catheter. In this way, the maximum tension on the leaflet sutures (during systole) does not change after the suture lock is locked, either before or after detachment of the catheter.

[0035] The helical anchor assembly 50 can be delivered by a ventricular anchor delivery subsystem 300. Figures 2C-2E show various views of the ventricular anchor delivery subsystem 300 and its components. Figure 2C shows a perspective view of the distal end of the subsystem 300. Figure 2D shows a perspective view of the proximal end of the subsystem 300. Figure 2E shows a partially exploded view of the distal end of the subsystem 300.

[0036] Subsystem 300 may be delivered through delivery catheter 100, which may access the left atrium via conventional techniques, such as atrial transseptal puncture. Delivery catheter 100 may be maintained in a substantially constant position throughout the procedure while the various subsystems are positioned and removed from delivery catheter 100. For example, the distal end of delivery catheter 100 may be positioned in the left atrium. In other embodiments, the distal end of delivery catheter 100 may be positioned in the left ventricle throughout the procedure.

[0037] As shown in FIGS. 2C-2E, ventricular anchor delivery subsystem 300 can include an outer sheath 304, a driver (including shaft 307 and head 306), an anchor hub 308, and an anchor 302. The anchor can be a helical anchor 302, and driver head 306 can be configured to rotate helical anchor 302. Helical anchor 302 can include an inner diameter configured to be received over the outer diameter of anchor hub 308. Helical anchor 302 can be securely secured to anchor hub 308 by an interference fit or other frictional engagement, soldering, or other known attachment techniques. Anchor hub 308 can remain implanted along with helical anchor 302.

[0038] The anchor hub 308 can include a lumen disposed substantially along a central axis of the anchor hub 308 for receiving the suture 74 ( FIG. 2A ) and attaching the suture 74 to the helical anchor 302. In some embodiments, the suture 74 can include an attachment element (e.g., a knot or washer) having a diameter sized to prevent the suture 74 from being pulled proximally through the anchor hub 308 lumen. For example, the suture 74 can be knotted distally in the lumen. In some embodiments, the suture 74 can be tied to the anchor hub 308 (e.g., passed through the lumen and wrapped around an outer surface or a structure such as a cross pin 76 and tied to itself, as shown in FIG. 2B ).

[0039] Helical anchor 302 may include a distal winding portion and a proximal winding portion. The proximal winding portion may be more closely spaced than the distal winding portion and may be configured to secure helical anchor 302 to anchor hub 308. The distal winding portion may be more widely spaced than the proximal winding portion and may be configured for insertion into ventricular tissue. Anchor hub 308 may have an enlarged cross-section at its proximal end configured to contact helical anchor 302 and / or to prevent helical anchor 302 from advancing proximally beyond the proximal end of anchor hub 308. Other helical anchors described elsewhere herein may also be configured for use with ventricular anchor delivery subsystem 300 described herein.

[0040] The proximal face of helical anchor 308 may include a recess for receiving extension portion 306' of drive head 306. The recess may be non-circular (e.g., polygonal, such as rectangular or hexagonal) so as to be configured to transfer torque from the driver to anchor hub 308 upon rotation of the driver. The recess may be located around a central lumen of anchor hub 308.

[0041] In other embodiments, the anchor hub 308 can include an extension portion, and the driver 306 can have a corresponding recess. The driver head 306 can be generally cylindrical with a distally facing post or opening having a complementary configuration for rotationally engaging a corresponding component on the anchor. The drive head 306 can be fixedly coupled to the drive shaft 307. The driver can include a central lumen through the drive head 306 and the drive shaft 307 configured to receive the suture 74. The central lumen of the driver can be configured to align with the central lumen of the anchor hub 308. The drive shaft 307 can be received within the guide shaft 305. The diameter of the drive head 306 can be larger than the inner diameter of the guide shaft 305. The outer sheath 304 can be sized to receive the guide shaft 305 along with the drive head 306, anchor hub 308, and helical anchor 302.

[0042] The outer sheath 304 can be delivered within the left ventricle and proximal to the ventricular attachment site via the delivery catheter 100. In some embodiments, the outer sheath 304 can be delivered without a delivery catheter. In some embodiments, the outer sheath 304 can be positioned proximal to the ventricular attachment site and then pushed distally through the outer sheath 304, or the helical anchor 302 can be hidden within the outer sheath 304 until the outer sheath 304 is retracted proximally to expose the helical anchor 302. The helical anchor 302 can be brought into contact with ventricular tissue. Rotating the drive shaft 307 rotates the drive head 306, anchor hub 308, and helical anchor 302, thereby threading the ventricular anchor 302 into the ventricular tissue. Rotating the driver 309 can axially advance the driver 309, anchor hub 308, and helical screw 302 distally relative to the outer sheath 304.

[0043] Drive shaft 307 can be manually rotated by a user using drive handle 312, as shown in FIG. 2D. As shown in FIG. 2D, the proximal end of ventricular anchor delivery subsystem 300 can include first and second hemostatic valves 314, 316. First hemostatic valve 314 can be located distal to drive handle 312 and can provide access to guide shaft 305. Second hemostatic valve 316 can be located proximal to drive handle 312 and can provide access to a central lumen of the drive. A ventricular anchor suture (not shown) can extend through second hemostatic valve 316.

[0044] In some embodiments, the insertion portion 306' of the drive head 306 and the recess in the anchor hub 308 may have a frictional engagement that temporarily holds the two components together. The frictional engagement can be released upon proximal retraction of the drive portion by a reaction force from the ventricular tissue once the helical anchor 302 is inserted. In some embodiments, proximal tension on the suture 74 can provide an engagement force between the proximal hub 308 and the drive head 306, which can be released upon retraction of the drive portion 309. The drive head 306 can be retracted proximally into the outer sheath 304 before the outer sheath 304 is retracted into the delivery catheter 100.

[0045] The unimplanted components of the ventricular anchor delivery subsystem 300 can be removed from the delivery catheter 100, and subsequent subsystems can be placed into the delivery catheter 100 to complete the implantation of the neochordae tendineae. In modified embodiments, the ventricular anchor delivery subsystem 300 and subsequent subsystems, such as the leaflet anchor delivery subsystem 330, can be placed simultaneously within the delivery catheter 100, and in some arrangements, both the tissue and leaflet anchors can be preloaded into the delivery catheter. In alternative embodiments, implantation of the ventricular anchors can be performed in a different order (e.g., after implantation of the leaflet anchors). The ventricular anchor delivery components can be retracted proximally beyond the proximal ends of the sutures 74, which remain extended through the delivery catheter 100 to the ventricular anchor 302.

[0046] 3-6 illustrate the deployment of the leaflet anchors. Referring to FIG. 3, the ventricular anchor 32 is deployed and coupled to the catheter 100 by the ventricular anchor suture 74, and the ventricular anchor subsystem is removed. The leaflet anchor is carried within a needle 338 directed toward a target site on the atrial side of the valve leaflet. The needle 338 is carried axially relative to one another within the catheter 100, such as within a tubular sleeve 332 advanceable through the catheter 100. Additional details of the needle and needle driver are discussed below.

[0047] As shown in Figure 3, in the illustrated configuration, the needle passes through the leaflet from the atrium to the ventricle, and the pre-loaded suture can be advanced into the ventricle. The suture can then be used to fold the pledget against the ventricular side of the leaflet and secure the suture to the leaflet, as shown in Figure 4. The pledget thus forms a radially expandable leaflet anchor. In certain embodiments, other forms of radially expandable leaflet anchors can be used.

[0048] The leaflet anchors and sutures can then be used in combination with ventricular anchors, sutures, and suture locks to effectively create new mitral chordae as shown in Figure 5. As previously mentioned, the leaflet anchors and sutures can be used in combination with the systems and methods for transvascular artificial chordae implantation disclosed in U.S. Patent Application No. 15 / 858,671 (incorporated herein by reference in its entirety) and the various embodiments of the ventricular anchors, sutures, and suture locks disclosed therein.

[0049] Preferably, the leaflet anchor deployment subassembly is provided with a temporary anchor for capturing and stabilizing the leaflet while the needle tip 338 is advanced through it at the target site. As shown in FIGS. 3 and 4 , the distal end 400 of the delivery tube 332 or other system component has a temporary tissue anchor, such as a helical tissue anchor 402. Because the temporary anchor 402 is intended to only temporarily engage the leaflet, the anchor 402 does not have distal barbs, but may otherwise be similar to the leaflet anchor 54. As such, the anchor 402 includes a helical element 406 terminating in a distal tip 408.

[0050] In use, the distal tip 408 is placed at a target site on the surface of the valve leaflet, and the helical element 406 is rotated about its axis to engage and penetrate the leaflet. The needle tip 338 may optionally engage the leaflet prior to rotation of the helical element 406 and may be utilized to stabilize the anchor against movement away from the target site in response to rotation, in a manner similar to that described in connection with the ventricular anchor and Figures 2A and 2B.

[0051] After the helical element 406 captures the leaflet from the atrial side and engages to secure the leaflet to the catheter, the needle can be advanced distally through the central lumen defined by the helical element 406 and completely through the leaflet so that the needle tip 338 emerges from the ventricular side of the leaflet as seen in Figure 4. An anchor deployment actuator, such as a pusher extending through the needle, can be utilized to deploy the anchor from the needle into the ventricle.

[0052] Referring to FIG. 5 , the leaflet anchor may be a pledget 340 similar to those described elsewhere herein. The pledget 340 may be coupled or attached to the distal end of a leaflet anchor suture 344. The pledget may comprise a soft and / or flexible material, such as fabric. The suture 344 may extend through the needle 336. The pledget 340 may be folded or compressed to a configuration including a reduced radial cross-section so that it can be placed within the needle 336 for delivery, as shown in FIGS. 8 and 10 , discussed below. The pledget 340 may expand from a reduced cross-section to assume a larger radial cross-section upon deployment from the distal end of the needle tip 338, as shown in FIG. 5 . In some embodiments, the pledget 340 may be pushed through the needle 336 via a push wire or release wire (not shown). Once delivered through the needle tip 338, proximal retraction of the leaflet suture 344 allows the leaflet anchor to assume an axially collapsed and radially expanded configuration, as shown in FIG. 6, which prevents the leaflet anchor from retracting through the leaflet puncture, thereby securing the leaflet suture 344 to the leaflet, as shown in FIG. 7.

[0053] 6A-6D schematically illustrate a pledget 340 connected to the distal end of a leaflet suture 344. The pledget 340 may include two wings 341, 342, which can be rolled / folded (e.g., both clockwise or counterclockwise) around the longitudinal axis of the pledget 340 to form a reduced cross-sectional configuration. In some embodiments, the leaflet suture 344 may be integrally formed with the pledget 340. To create the collapsible configuration, the suture 344 may extend distally through the pledget, loop around the distal end of the pledget, return proximally, and thread back through one or more openings (e.g., two openings, three openings, four openings, etc.) formed in the pledget 340, as shown in FIG. 6A. In some embodiments, the openings may be aligned along the center of the pledget 340.

[0054] The openings can extend through the pledget 340 and through the portions of the embedded portions of the sutures 344 that are integral with the pledget 340. The embedded portions of the sutures 344 may be at least partially flattened within the pledget 340. In some embodiments, the openings can be located substantially near the center of the pledget (e.g., immediately to the left or right of the embedded sutures 344, or alternating between the left and right sides of the sutures 344). When deployed, the sutures 344 can be effectively coupled to the distal end of the pledget 340 (e.g., the sutures 344 can loop back into position to be inserted between the pledget sheets).

[0055] Figures 6B-6D schematically illustrate examples of pledgets as described elsewhere herein. Figure 6B schematically illustrates pledget 340 formed by adhering the distal end (shown in dashed lines) of suture 344 between two flat sheets, resulting in the formation of the sheet for left and right wings 341, 342. Figure 6C illustrates a cross-section of pledget 340 along the axis B-B illustrated in Figure 6B. In some embodiments, suture 344 may be inserted between the two sheets (e.g., substantially down the middle of the sheets) and then pressed and / or laminated (e.g., under heat and / or pressure) to bond the three components together. At least one layer may be partially sintered. Suture 344 may be flattened and / or densified to improve the suture's resistance to tearing. The sheets may be flat polytetrafluoroethylene (PTFE) sheets (e.g., thin, uncured expanded PTFE (ePTFE) sheets) or other suitable materials. In some embodiments, the leaflet sutures 344 may be arranged between the sheets in other configurations, such as a zigzag or S-shape. Figure 6D shows the pledget 340 of Figure 6B including multiple openings 343 for securing the proximal tail ends of the sutures 344.

[0056] In some embodiments, one or more openings 343 can be formed through the pledget in various configurations to form a collapsible structure configured to secure the suture 344 to the mitral valve leaflets, as described elsewhere herein. FIG. 6D shows the openings 343 alternating around both sides of the suture 344. In some embodiments, the openings 343 may be formed on the same side of the suture 344 (e.g., wing 341 or wing 342). In some embodiments, the openings 343 can be formed through the suture 344. The openings 343 may be aligned along the center of the pledget 340. The openings 343 may be aligned along the length of the suture 344 (e.g., forming a straight line). The suture 344 can be at least partially flattened between two opposing sheets, which facilitates placement of the openings 343 through the suture 344. Various combinations of openings 343 can be used, including the arrangements described above.

[0057] The pledget 340 may be shaped so that the wings 341, 342 are approximately the same size, or may be shaped so that they are unequal in size. Upon proximal retraction of the leaflet sutures 344, the pledget 340 may collapse into an accordion-like configuration, as shown in FIG. 6A . The pledge 340 may be configured to include a generally planar proximal surface that is generally perpendicular to the long axis of the leaflet sutures 344. This configuration may facilitate securing the sutures 344 to the leaflets. Once the leaflet sutures 344 are secured within the leaflets, the leaflet anchor delivery subsystem 340 is withdrawn from the delivery catheter 100. The leaflet anchor delivery components, along with the ventricular anchor sutures 74, may be retracted proximally beyond the proximal ends of the sutures 344, which remain extended through the delivery catheter 100 to the leaflet anchor 340.

[0058] Figures 8-10 show various views of the leaflet anchor delivery subsystem 330 and its components. Figure 8 shows a perspective view of the distal end of the subsystem 330. Figure 9 shows a perspective view of the proximal end of the subsystem 330. Figure 10 shows an exploded view of the distal end of the subsystem 330.

[0059] As shown in Figures 8 and 10, leaflet anchor delivery subsystem 330 can include an outer delivery tube 332. Tube 332 can optionally include a deflection zone and can be configured to be manipulated by an operator, such as by proximal retraction of one or more pull wires (not shown) along various sides of flexible tube 332. The operator can control the bending of the flexible tube via a knob 352 or lever or other actuation mechanism located on a handle 350 at the proximal end of leaflet anchor delivery subsystem 330, as shown in Figure 9.

[0060] An inner tubular shaft or needle 336, terminating at its distal end in a needle tip 338, can extend through the delivery tube 332. The inner needle 336 may comprise hypotube, extruded tubing, or braided tubing or a catheter that is flexible enough to conform to the shape of any flexible tube 332. The needle tip 338 may be coupled to the distal end of the inner flexible shaft 336. A flexible jacket 333 may surround the flexible tube 332 and the delivery shaft 334.

[0061] As shown in FIG. 9 , the proximal end of the inner tubular shaft 336 may be connected to a needle handle 354. The needle handle 354 may include a hemostatic valve 356. The leaflet suture 344 may be inserted through the valve 356. The valve 356 may be a Tuohy-Borst valve. The needle handle 354 may include an additional port 358 for accessing the lumen of the inner flexible shaft 336. The needle handle 354 may be positioned proximal to the handle 350 such that the inner flexible shaft 336 extends through the handle 350 and into the lumen of the delivery shaft 334. The handle 350 may include a hemostatic valve to receive the inner flexible shaft 336 and seal the internal components of the handle, including the opening to the delivery shaft 334, from the surrounding environment.

[0062] The needle tip 338 may be retractable by extending the needle handle 354 toward or retracting the needle handle 354 from the handle 350. Distal advancement of the needle 336 may be achieved by manually advancing the handle 354. Alternatively, distal advancement of the needle may be assisted by a mechanical or electromechanical mechanism that produces relatively fast, short-stroke distal advancement.

[0063] Pressure on the valve leaflet as the needle tip 338 extends distally beyond the vessel 332 may cause the needle tip 338 to pierce the valve leaflet such that the needle tip 338 extends to the opposite side of the leaflet (e.g., the atrial side), as shown in Figure 4. This pressure may be generated by extending the needle tip 338 and / or by retracting the entire delivery device 330 proximally with the needle tip 338 in the extended position.

[0064] The ventricular anchor suture 74 and the leaflet anchor suture 344 can be tied together under tension to form a neochordae implant or to tie two segments of a neochordae implant together, so that the neochordae extend across the atrial side of the coaptive edges of the leaflets between the ventricular anchor 302 and the leaflet anchor 340. The total length of the neochordae is adjusted by applying traction proximally to one or both sutures 74, 344 before engaging the suture lock 376 so that the appropriate tension is applied to the leaflets, with the tension then being maintained by the ventricular anchor 302. The sutures 74, 344 may extend proximally through the delivery catheter 100 to a location outside the body. In some embodiments, the proximal ends of the sutures 74, 344 may be fed into the handle or proximal portion of the suture lock delivery system 370 to facilitate placement of the suture lock and cutting of the sutures 74, 344. In some embodiments, the proximal ends may be left free or may be connected or secured by other means.

[0065] FIG. 11 illustrates the advancement of the suture lock 376 over the ventricular anchor suture 74 and the leaflet sutures 344. The suture lock delivery subsystem 370 can be advanced through the delivery catheter 100, and a tubular pusher catheter 372 can push the suture lock 376 distally along the sutures 74, 344. Once the suture lock 376 reaches the ventricle, proximal traction on the suture 74 can continue to push the suture lock 376 along the ventricular suture 74, while the leaflet sutures 344 can be fed distally through the catheter if necessary to advance the suture lock 376 distally to the ventricular anchor. As discussed further below, FIG. 12 illustrates the final configuration in which the leaflet anchor and ventricular anchor are joined to form the artificial chordae tendineae. The proximal tails of the two sutures are cut, and the catheter is retracted proximally from the ventricle through the mitral valve.

[0066] Figures 13-14 show various views of the suture lock delivery subsystem 370 and its components. Figure 13 shows a perspective view of the distal end of the subsystem 370. Figure 14 shows a perspective view of the proximal end of the subsystem 370. Figure 15 shows a partially exploded view of the distal end of the subsystem 370. Figure 16 shows a perspective view of the distal end of the cutting assembly. Figures 17 and 18 show side views of the cutting assembly portion of the subsystem 370. Figure 19 shows a side view of the suture lock 376 and the distal end of a torque drive 388 configured to engage the suture lock 376. Figures 20 and 21 show proximal and distal end views, respectively, of the suture lock 376.

[0067] The suture lock delivery subsystem 370 may be configured to advance (e.g., slide) the suture lock 376 over both sutures 74, 344 (or three, four, or additional sutures). The sutures 74, 344 may each be retracted proximally relative to the suture lock 376 to tension the sutures 74, 344 and adjust the length of each suture 74, 344 between the suture lock 376 and the corresponding tissue anchor 302, 340. Once the tension and length of the neochordae implant are optimized, the suture lock 376 may be locked to fix the length of the sutures 74, 344 so that they can no longer move relative to the suture lock 376. The sutures 74, 344 may then be cut at a point proximal to the suture lock 376. The sutures 74, 344 can be cut by the same suture lock delivery subsystem 370 that delivers the suture lock 376. In other embodiments, a separate cutting device may be inserted into the delivery catheter 100 after the suture lock is locked in place.

[0068] The suture lock allows one or more sutures to be advanced and adjusted, and then locks with sufficient clamping efficiency to prevent the ePTFE suture from slipping out of the suture lock under normal use conditions (e.g., use conditions that allow the suture to withstand tension of at least about 60% or 80% of the suture's breaking strength without slipping). The lock can be reopened to readjust the tension on the mitral valve leaflets and retightened until the desired result is achieved. The clamping tool can then be removed, leaving the sutures secured.

[0069] The suture lock 376 can be advanced along the suture by a retention catheter 373. The distal end of the retention catheter 373 can be coupled to a retention element 377 ( FIG. 15 ). The retention element can include a flange 371 or other mechanical feature configured to engage the suture lock 376. For example, the flange 371 can be inserted into a recess in the proximal end of the suture lock 376. In some embodiments, rotation of the retention catheter 373 and / or movement of the retention catheter 373 generally perpendicular to the axial direction can disengage the retention catheter 373 from the suture lock 376.

[0070] The sutures 74, 344 may extend from their respective tissue anchors and pass through the suture lock 376, entering through a distal opening 395 on the distal face of the suture lock 376, as shown in FIG. 21 , and exiting the suture path through a proximal opening 394 on the proximal face of the suture lock 376, as shown in FIG. 20 . The sutures 74, 344 may extend through a channel in the cutter head 375 proximal to the suture lock 376, along the outside of the retention catheter 373, and through the delivery catheter 100. The cutter head 375 may be coupled to the distal end of the cutter catheter 372. The retention catheter 373 may extend through the interior lumen of the cutter catheter 372 such that the two catheters 372, 373 are extensible or retractable relative to one another.

[0071] Once the sutures 74, 344 are locked (secured) within the suture lock 376, the proximal ends of the sutures 74, 344 can be severed adjacent the proximal surface of the suture lock. The sutures 74, 344 can be severed by advancing a cutter catheter 372 coupled to a cutter head 375 toward the proximal surface of the suture lock 376. As shown schematically in FIGS. 17-18 , as the cutter head 375 advances along the retention catheter 373 toward the retention element 377, the cutter head brings the sutures 74, 344 into proximity with a cutting blade 379 disposed on the retention element 377. The cutter head 375 is configured to advance over the retention element 377 such that the channel within the cutter head 375 that holds the sutures 74, 344 is gradually occupied by the blade 379. As the blade 379 is forced into the channel of the cutter head 375, the blade 379 shears the sutures 74, 344. The application of proximal tension to the suture 74, 344 can facilitate severing of the suture 74, 344. In other embodiments, different actuations (e.g., rotation of the cutting catheter) can be configured to sever the suture 74, 344.

[0072] In some embodiments, two or more sutures can be used and locked within the suture lock 376 and cut in a similar manner by the suture lock delivery subsystem 370. In some embodiments, advancement of the cutter head 375 over the retention element 377 can facilitate removal of the retention catheter 373 from the suture lock 376. For example, the cutter head 375 can be advanced to a distal position configured to stabilize the suture lock 376, allowing the retention catheter 373 to disengage axially and / or rotationally from the suture lock 376.

[0073] FIG. 19 shows a side view of an example suture lock 376 (with its outer casing / shell removed). A suture can be passed through the suture lock 376 from its distal end to its proximal end, as described elsewhere herein. The suture lock 376 can include a screw 382 configured to advance or retract a push wedge 384 distally or proximally, depending on the direction of rotation. The screw 382 can be rotated by a torque shaft 388. The torque shaft 388 can include a driver head configured to mate with a recess 381 (e.g., a polygonal recess or other non-circular recess, as shown in FIG. 20 ) located at the proximal end of the suture lock 376 so that rotation of the torque shaft 388 causes rotation of the screw 382. The torque shaft 388 can extend through the internal lumen of the retention catheter 373. The torque shaft 388 can be rotated at its proximal end by a knob 398 or other actuation mechanism located at the proximal end of a subsystem handle 396. The handle 396 can include a hemostatic valve 397. In some embodiments, the sutures 311, 344 can pass through the hemostatic valve 397.

[0074] Advancement of the push wedge 384 by the torque shaft 388 causes the angled surface 386 to gradually compress one or more springs, such as a spring pin 388. The springs urge the clamp upward, opening the suture path, until rotation of the torque shaft 388 forces it closed. The compressive force of the one or more springs 388 presses the clamp 390 downward onto the sutures 311, 344, compressing the sutures 311, 344 between the two opposing surfaces. In some embodiments, the clamp 390 and the opposing surface 392 may have notched surfaces configured to mate with each other at their respective increments. The mated notched surfaces can provide increased friction and, in some embodiments, mechanical interference to hold the sutures 311, 344 between the opposing surfaces so that they cannot be pulled either proximally or distally from the suture lock 376. In some embodiments, the clamping may be reversible by rotating the torque shaft in the opposite direction.

[0075] Once the suture lock is properly positioned over the sutures 74, 344 and locked in place, the sutures 74, 344 may be severed as described elsewhere herein. Figure 12 shows retraction of the suture lock delivery subsystem 370 after the sutures 74, 344 have been severed. Once the suture lock delivery subsystem 370 has been detached from the delivery catheter 100, the delivery catheter 100 may be withdrawn from the body.

[0076] While this disclosure describes particular embodiments and examples, many aspects of the above-described systems and methods can be differently combined and / or modified to form further embodiments or acceptable examples. All such modifications and variations are intended to be included herein within the scope of this disclosure. Indeed, a wide variety of designs and approaches are possible and are within the scope of this disclosure.

[0077] Furthermore, certain features that are described in this disclosure as the content of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described as the content of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Furthermore, even if features are described as working in a particular combination, one or more features of a claimed combination may, in some cases, be deleted from the combination, and such combination may be claimed as a subcombination or a variation thereof.

[0078] Any particular feature, aspect, method, property, characteristic, quality, attribute, element, etc. disclosed herein in connection with various embodiments can be used in all other embodiments set forth herein. Additionally, any method described herein can be performed using any apparatus suitable for performing the described steps.

[0079] Furthermore, while components and operations may be depicted in the figures or described in the specification in a particular arrangement or order, such components and operations need not be arranged and performed in the particular arrangement and order shown in the figures, nor in any sequential order, nor inclusive of all of the components and operations, to achieve desirable results. Other components and operations not shown or described may be incorporated into the examples and implementations. For example, one or more additional operations may be performed before, after, simultaneously with, or during any of the described operations. Moreover, operations may be rearranged or reperformed in other embodiments. Also, the separation of various system components in the above-described embodiments should not be construed as requiring such separation in all embodiments, and it should be understood that the described components and systems may generally be integrated into a single product or packaged into multiple products.

[0080] In summary, various exemplary embodiments and examples have been described herein. While systems and methods have been disclosed as embodiments and examples thereof, the disclosure extends beyond the specifically disclosed embodiments to other alternative examples and / or other uses of the embodiments, as well as certain modifications and equivalents thereof. The disclosure expressly contemplates that various features and aspects of the disclosed embodiments can be combined with or substituted for one another. Accordingly, the scope of the disclosure should not be limited by the particular disclosed embodiments described above, but should be determined only by a fair reading of the claims and their full scope of equivalents.

Claims

1. An intravascular suture lock, comprising: a body having a suture channel extending therethrough; a movable wall within the housing for reducing a cross-sectional dimension of the suture path; a rotatable coupling on the housing; a drive mechanism for advancing the movable wall in response to rotation of the rotatable coupling; 1. An endovascular suture lock comprising:

2. An intravascular suture lock as described in claim 1, having a friction-enhancing surface exposed in the suture path.

3. An intravascular suture lock as described in claim 2, wherein the friction-enhancing surface is on the movable wall.

4. An intravascular suture lock as described in claim 1, comprising a push wedge having an angled surface and movable axially within the housing.

5. An intravascular suture lock as described in claim 4, wherein rotation of the rotatable coupling advances the push wedge axially, thereby advancing the movable wall laterally and changing the cross-sectional dimensions of the suture path.

6. An intravascular suture lock as described in claim 5, wherein the movable wall has a suture gripping surface on a first side and a sloped surface on a second side, the sloped surface configured to be in sliding contact with the angled surface on the push wedge.

7. An intravascular suture lock as described in claim 4, further comprising a screw configured to advance the push wedge distally or retract it proximally.

8. An intravascular suture lock as described in claim 7, further comprising a recess that releasably engages with a torque shaft for rotating the screw.

9. An intravascular suture lock as described in claim 1, wherein the movable wall comprises a clamp having a friction-enhancing surface exposed to the suture path.

10. An intravascular suture lock as described in claim 9, wherein the intravascular suture lock has a clamping efficiency sufficient to withstand a suture tension of at least about 60% of the suture breaking strength.

11. An intravascular suture lock as described in claim 9, wherein the intravascular suture lock has a clamping efficiency sufficient to withstand a suture tension of at least about 80% of the suture breaking strength.

12. An intravascular suture lock as described in claim 9, wherein the clamp has a notched surface.

13. An intravascular suture lock as described in claim 12, wherein the notched surface of the clamp is located on the opposite side of the suture path and spaced apart from an opposing surface, and the opposing surface has a notch.

14. An intravascular suture lock as described in claim 13, wherein the cutout surface and the opposing surface of the clamp are configured to fit together.

15. An intravascular suture lock as described in claim 1, comprising a spring that biases the movable wall away from the suture path.

16. An intravascular suture lock as described in claim 1, wherein the drive mechanism includes a screw.

17. The intravascular suture lock of claim 1, configured to clamp a suture, release the suture, and re-clamp the suture.

18. An intravascular suture lock as described in claim 1, comprising a clamping surface having a notch and an opposing surface having a notch configured to provide mechanical interference to hold a suture between said clamping surface.

19. An intravascular suture lock as described in claim 1, wherein the suture pathway is configured to accept at least two sutures.

20. The endovascular suture lock of claim 1, wherein the endovascular suture lock is configured for transvascular delivery to a ventricle within the heart.

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