Method and apparatus for mitral valve chordae repair

Abstract

Methods and devices for transvascular artificial chordae implantation are disclosed. The catheter is advanced into the left atrium. The catheter may be anchored to an upper surface of the mitral valve leaflet from the atrial side, and the leaflet anchor may be advanced into the mitral valve leaflet to secure the mitral valve leaflet to the leaflet suture. The ventricular anchor is anchored to the ventricular wall to secure the ventricular wall to the ventricular suture. The leaflet suture and the ventricular suture may be tensioned and joined by the suture lock to form the artificial chordae tendineae.

Description

[0001] This application is a divisional application of the application filed on September 29, 2020, with application number 201980023765.8 and title "Methods and Devices for Mitral Chordae Tendineae Repair". Incorporation by reference of any priority applications

[0002] This application claims the benefit under 35 U.S.C. § 119(e) of U.S. Provisional Application No. 62 / 641,612, filed on March 12, 2018, the entire content of which is incorporated herein by reference for all purposes. This application is also a continuation-in-part of U.S. Application No. 15 / 858,671, filed on December 29, 2017, which is a continuation-in-part of U.S. Application No. 15 / 638,176, filed on June 29, 2017 (now U.S. Patent No. 9,877,833), which claims the priority of U.S. Provisional Application No. 62 / 441,031, filed on December 30, 2016, the entire content of each of these applications being incorporated herein by reference for all purposes. Any and all applications for foreign or domestic priority claims identified in the application data sheet filed with this application are incorporated herein by reference in accordance with 37 CFR 1.57. Technical Field

[0003] The present disclosure relates to mitral valve repair or replacement, and more generally to methods and devices for mitral valve remodeling, repair, and / or replacement of mitral chordae tendineae to restore normal function of the mitral valve from a mitral regurgitation condition. Background Art

[0004] The heart includes four heart valves that allow blood to pass through the four chambers of the heart in one direction. The four valves are the tricuspid valve, the mitral valve, the pulmonary valve, and the aortic valve. The four chambers are the right atrium and the left atrium (upper chambers) and the right ventricle and the left ventricle (lower chambers).

[0005] The mitral valve is formed by two leaflets, which are referred to as the anterior leaflet and the posterior leaflet, and they open and close in response to the pressure applied to the leaflets by the pumping through the heart. Several problems can form or occur with respect to the mitral valve. These problems include mitral regurgitation (MR), in which the mitral valve leaflets do not close properly, which can result in leakage of the mitral valve. Severe mitral regurgitation can adversely affect heart function and compromise the quality of life and life expectancy of the patient.

[0006] Several techniques have been developed for correcting mitral regurgitation. Depending on the stage and underlying cause, these techniques include heart transplantation, valve replacement or repair, chordae tendineae shortening or replacement, and mitral annuloplasty, also known as mitral ring repair.

[0007] Since correction involves chordal replacement or repair, certain surgical and transapical approaches have been proposed. Despite these efforts, there remains a need for a transvascular approach for chordal replacement or repair to reduce or eliminate MR. SUMMARY OF THE INVENTION

[0008] One aspect of the invention includes a transvascular method of implanting an artificial chord, the method comprising the steps of: advancing a catheter into the left atrium, through the mitral valve, and into the left ventricle; deploying a ventricular anchor from the catheter and into the wall of the left ventricle, leaving a ventricular suture attached to the ventricular anchor and extending proximally through the catheter; advancing a leaflet anchor from the atrial side through the upper surface of the mitral valve leaflet to position the leaflet anchor against the lower (ventricular) side of the leaflet using a leaflet suture that extends proximally through the leaflet, into and through the catheter; and securing the leaflet suture to the ventricular suture at the top of the leaflet junction edge to limit the travel of the leaflet in the direction of the left atrium.

[0009] Another aspect of the disclosure is a leaflet anchor deployment system, the system comprising: a catheter having a proximal end and a distal end; a leaflet anchor positioned at the distal end of the catheter; and a needle capable of advancing through the leaflet anchor, the needle releasably carrying a radially expandable leaflet anchor preloaded therein and having a suture extending proximally through the catheter.

[0010] According to another aspect of the invention, there is provided a transvascular method of implanting an artificial chord. The method comprises the steps of: advancing a catheter into the left atrium, through the mitral valve, and into the left ventricle; deploying a ventricular anchor from the catheter and into the wall of the left ventricle, leaving a ventricular suture attached to the ventricular anchor and extending proximally through the catheter; fixing a leaflet anchor catheter to the mitral valve leaflet from the atrial side; advancing the leaflet anchor from the catheter through the mitral valve leaflet with the leaflet anchor catheter fixed to the leaflet to fix the mitral valve leaflet to the leaflet suture, wherein the leaflet suture extends proximally through the catheter; and fixing the leaflet suture to the ventricular suture to limit the travel of the leaflet in the direction of the left atrium.

[0011] The step of advancing the leaflet anchor from the catheter through the mitral valve leaflet to fix the mitral valve leaflet to the leaflet suture may include: advancing a needle preloaded with the leaflet anchor through the upper surface of the mitral valve leaflet. The step of fixing the leaflet anchor catheter to the mitral valve leaflet may include: using a leaflet connector. The leaflet connector may include a spiral anchor or a tissue hook.

[0012] According to another aspect of the present invention, a method of attaching a leaflet anchor to a mitral valve leaflet is provided. The method includes the steps of: advancing a catheter into the left atrium; attaching, from the atrial side, a leaflet connector coupled to the catheter to the leaflet from the atrial side of the mitral valve leaflet; and after attaching the leaflet connector to the mitral valve leaflet, advancing the leaflet anchor through the mitral valve leaflet to attach the mitral valve leaflet to the leaflet suture.

[0013] The step of advancing the leaflet anchor through the mitral valve leaflet to attach the mitral valve leaflet to the leaflet suture may include: advancing a needle pre-loaded with the leaflet anchor through the mitral valve leaflet from the atrial side. The needle may be advanced through the leaflet connector. The leaflet connector may include a spiral anchor.

[0014] According to another aspect of the present invention, a leaflet anchor deployment system is provided. The system includes: a catheter having a proximal end and a distal end; a leaflet connector positioned at the distal end of the catheter; and a needle capable of being advanced through the leaflet connector, the needle including a radially expandable leaflet anchor pre-loaded therein and having a suture extending proximally through the catheter. The leaflet connector may include a spiral anchor.

[0015] According to another aspect of the present invention, a new chordae tendineae deployment system is provided. The system includes: a catheter having a proximal end and a distal end; a spiral ventricular anchor subassembly capable of extending through the catheter and having a ventricular suture extending proximally through the catheter; and a leaflet anchor deployment subassembly capable of extending through the catheter, having a radially expandable leaflet anchor within the subassembly and having a leaflet suture extending proximally through the catheter.

[0016] The radially expandable leaflet anchor may include packing. The packing may be transformed from an elongated strip configuration to a radially expanded and axially shortened configuration by proximal retraction of the suture. The radially expandable leaflet anchor may include a leaflet suture positioned between two material sheets. The radially expandable leaflet anchor may be carried within a needle having a tip for piercing the leaflet. The leaflet anchor deployment subassembly may include an elongated tube having a distal end and a central lumen and a leaflet connector at the distal end. The leaflet connector may include a spiral leaflet anchor. The needle is capable of moving axially relative to the spiral leaflet anchor. The system may further include: a suture locking subassembly capable of being advanced through the catheter and configured to connect the ventricular suture to the leaflet suture.

[0017] According to another aspect of the present invention, a leaflet anchor delivery subsystem is provided. The subsystem includes: an elongate flexible tubular body having a proximal end, a distal end, and a central lumen; a deployment needle axially movably advanced 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 is axially extendable through the helical element.

[0018] According to another aspect of the present invention, a tissue anchor is provided. The tissue anchor includes: a hub; a suture extending proximally from the hub; a helical anchor extending distally from the hub; and a core wire concentrically extending through the helical anchor and beyond the distal end of the helical anchor.

[0019] The tissue anchor may further include a suture anchor guide extending proximally from the hub. The tissue anchor may further include a tubular cannula extending proximally from the hub and having a length of no more than about 10 cm. The tissue anchor may further include a radiopaque marker carried by the cannula. 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 at the distal end of the helical anchor; and barbs on the helical anchor configured to resist rotation of the helical anchor in engagement with tissue.

[0020] According to another aspect of the present invention, a tissue anchor with a dynamic depth indicator is provided. The tissue anchor includes: 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 for biasing the radiopaque marker in the distal direction; wherein the radiopaque marker is advanced proximally relative to the tissue anchor in response to the tissue anchor being advanced into tissue.

[0021] According to another aspect of the present invention, an intravascular suture lock is provided. The suture lock includes: a body having a suture path extending therethrough; a movable wall in the housing for reducing the cross-sectional size of the suture path; a rotatable coupler on the housing; and a drive mechanism for advancing the movable wall in response to rotation of the coupler.

[0022] The suture lock may additionally include a friction-enhanced surface exposed to the suture path. The friction-enhanced surface may be located on a movable wall. The suture lock may include a push wedge having an angled surface and being axially movable within the housing. Rotation of the coupler may axially advance the push wedge, which will laterally advance the movable wall to change the cross-sectional dimension of the suture path. The movable wall may include a suture gripping surface on a first side and a ramp surface on a second side, the ramp surface being configured for sliding contact with the angled surface on the push wedge. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In conjunction with the drawings, the foregoing and other features of the present disclosure will become more fully apparent from the following description and the appended claims. It should be understood that these drawings only depict several embodiments in accordance with the present disclosure and should not be considered as limiting the scope.

[0024] Figure 1 Illustrates placement of a ventricular anchor into the mitral valve via a transseptal approach.

[0025] Figure 2A and Figure 2B Illustrates a ventricular anchor.

[0026] Figure 2C Is a perspective view of a ventricular anchor on the distal end of a ventricular anchor deployment tool.

[0027] Figure 2D Is a perspective view of the proximal end of a ventricular anchor deployment tool.

[0028] Figure 2E Is a partially exploded perspective view of the distal end of a ventricular anchor and a ventricular anchor deployment tool.

[0029] Figure 3 Illustrates the deployment end of a catheter positioned to engage the leaflets of the mitral valve.

[0030] Figure 4 Illustrates a leaflet captured by a helical leaflet anchor and a needle passing from the atrium through the leaflet to the ventricle.

[0031] Figure 5 Illustrates a pledgetted leaflet anchor deployed from the needle and entering the ventricle.

[0032] Figure 6A Illustrates proximal traction on a leaflet suture that collapses the pledget against the ventricular side of the leaflet.

[0033] Figures 6B to 6D Illustrates details of a pledgetted leaflet anchor.

[0034] Figure 7Illustrates the deployed ventricular anchor and suture and the deployed leaflet anchor and suture for preparing and attaching the suture lock.

[0035] Figure 8 Illustrates a perspective view of the distal end of the leaflet anchor delivery subsystem.

[0036] Figure 9 Illustrates a perspective view of the proximal end of the leaflet anchor delivery subsystem.

[0037] Figure 10 Illustrates an exploded view of the distal end of the leaflet anchor delivery subsystem.

[0038] Figure 11 Depicts advancing a suture lock via a suture lock delivery subsystem over a leaflet anchor suture and a ventricular anchor suture to connect the leaflet anchor to the ventricular anchor.

[0039] Figure 12 Depicts the suture lock in a locked position after the tension has been adjusted and the suture tail has been cut.

[0040] Figure 13 Depicts a perspective view of the distal end of the suture lock delivery subsystem.

[0041] Figure 14 Depicts a perspective view of the proximal end of the suture lock delivery subsystem.

[0042] Figure 15 Depicts a partial exploded view of the distal end of the suture lock delivery subsystem.

[0043] Figure 16 Depicts a perspective view of the distal end of the suture cutting assembly.

[0044] Figure 17 Depicts a side view of the cutting assembly portion of the suture lock delivery subsystem in a configuration where the cutting head has not been advanced to hold the suture before the suture is cut.

[0045] Figure 18 Depicts a side view of the cutting assembly portion of the suture lock delivery subsystem in a configuration where the cutting head has been advanced to cut the suture.

[0046] Figure 19 Depicts a side view of the distal end of the suture lock and a torque driver configured to engage the suture lock.

[0047] Figure 20 Depicts a proximal view of the suture lock.

[0048] Figure 21 Depicts a distal view of the suture lock. Detailed implementation manners

[0049] U.S. Patent Application 15 / 858,671, filed on December 29, 2017 (the entire content of which is incorporated herein by reference), discloses a transvascular artificial chordae tendineae implantation system and method. One aspect involves: advancing a catheter into the left atrium, through the mitral valve, and into the left ventricle; deploying a ventricular anchor from the catheter and into the wall of the left ventricle, leaving a ventricular suture attached to the ventricular anchor and extending proximally through the catheter; and advancing a leaflet anchor into the mitral valve leaflets to fix the mitral valve leaflets to a leaflet suture, wherein the leaflet suture extends proximally through the catheter, and causing the leaflet suture to extend above the top of the coaptation edge and fixing the leaflet suture to the ventricular suture to limit the range of travel of the leaflets in the direction of the left atrium. Certain aspects are further developed herein.

[0050] The path to the mitral valve can be achieved through a standard transseptal path to provide access to the left atrium. For this access, the first step can include fixing a leaflet capture catheter to the leaflets of the mitral valve in a position determined to optimally correct the regurgitation. Probing the leaflet surface from the superior atrial surface can advantageously provide immediate feedback regarding the optimal location for adding additional mitral chordae tendineae. In another embodiment of the present invention, the ventricular anchor is deployed first, followed by the deployment of the leaflet anchor.

[0051] See Figure 1 , a ventricular anchor such as a helical anchor 32 has been deployed near the apex 20 of the left ventricle 24. Although the helical anchor 32 is shown in the following figures as being positioned near the apex 20, the anchor 32 can be attached at a point on thin tissue away from the apex and can alternatively be implanted in the generally thicker adjacent wall of the ventricle, such as between two papillary muscles. This allows the implanted new chordae tendineae structure (sutures, optional new papillary muscles, and / or helical anchors) to be aligned along a longitudinal axis that is substantially parallel to the original path of the native chordae tendineae or coaxial therewith. In certain embodiments, the implanted new chordae tendineae structure is aligned along a longitudinal axis that is within 5 degrees, 10 degrees, or 15 degrees parallel to the original path of the native chordae tendineae and / or the path of adjacent native chordae tendineae. Additionally, although a helical anchor is illustrated, the anchor can have different structures for engaging cardiac tissue, and thus, other tissue anchor structures can be used in place of the helical structure, including various piercing, hook, or radially expandable structures known for engaging tissue.

[0052] See Figure 2A and Figure 2B, which illustrates an embodiment of a tissue anchor suitable for use as a ventricular anchor according to the present invention. The anchor assembly 50 will be described primarily in the context of the chordae tendineae repair application of the present invention; however, the anchor can be used in any of a variety of other applications where a soft tissue or bone anchor may be desired.

[0053] The anchor assembly 50 generally includes a coil 54, which can include any of a variety of materials, such as stainless steel or nitinol. The coil 54 extends helically between a proximal end 56 and a distal end 58. The distal end 58 is provided with a sharp tip 59 and also carries retention barbs 61, which are configured to resist reverse rotation of the coil and detachment from the tissue. The proximal end 56 of the coil 54 is carried by a hub 57 (attached to or integrally formed with it), which is discussed in more detail below.

[0054] Extending distally from the hub 57 and within the coil 54 is an elongate core wire 62 having a sharp tissue-piercing distal end 64. The distal end 64 is positioned distally of the distal end 58 of the coil 54. This enables the sharp distal end 64 to pierce the tissue upon contact and before the coil 54 begins to rotate, to embed the coil 54 within the target tissue. Engaging the distal end 64 prior to rotating the anchor stabilizes the anchor against lateral movement, allowing the anchor assembly 50 and the coil 54 to be placed against the tissue once and the coil 54 to be rotated to engage the tissue, without the anchor "walking away" 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 any of a variety of ways, such as by brazing, soldering, adhesives, and / or mechanical interference, such as by entering an aperture in the sidewall or other surface of the hub 57.

[0055] A radiopaque depth marker 66 is provided with an aperture 68 and is axially movably carried on the core wire 62. A distal stop 70, such as a radially outwardly extending protrusion or annular ridge, is carried by the core wire 62 and is spaced proximally of the sharp distal end 64 to provide a core wire guide segment 72 on the distal side of the stop 70 such that the marker 66 does not interfere with the tissue-anchoring function of the distal tip 64. The stop 70 is used to limit the distal travel of the marker 66. The marker 66 can be an annular structure, such as a disk having a central aperture for receiving the core wire 62.

[0056] The coil spring 71 is concentrically carried on the core wire 62 and biases the radiopaque marker 66 in the distal direction. Thereby, the radiopaque marker 66 is held in place against the proximal surface of the stop 70. In use, the marker 66 bears against the tissue surface at the target attachment site. As the helical coil anchor 54 rotates and advances distally into the tissue, the marker 66 bears proximally against the core wire 62 with the tissue surface to compress the coil spring 71 until the marker 66 retracts proximally into the hub when the tissue anchor is fully embedded. This enables the process of the coil into the tissue and the end point of the complete engagement of the coil 54 into the target tissue to be fluoroscopically visualized by observing the changing distance between the marker 66 and a reference such as the hub 57 or other radiopaque markers.

[0057] The hub 57 includes a proximal connector for engaging with a rotary driver as described elsewhere herein. In one embodiment, the connector includes an aperture, such as a hexagonal aperture, for removably engaging complementary surface structures on the distal end of the driver. The suture 74 is fixed to the anchor assembly 50, such as to the hub 57, the coil 54, or the core wire 62. In the illustrated embodiment, the suture 74 is attached to the cross pin 76, which can be inserted through one or two apertures in the sidewall of the hub and through the central hub lumen. The suture may additionally carry one or two or more radiopaque markers 82 spaced apart from the hub 57 and may extend proximally through the central lumen in the proximal connector and the rotary driver.

[0058] A suture lock guide, such as the tubular cannula 78, extends proximally from the hub 57 by at least about 2 mm or 4 mm or 8 mm, but generally not more than about 5 cm or 2 cm depending on the desired performance. The guide cannula 78 may include a flexible material, such as ePTFE. Preferably, the radiopaque marker band 80 is carried by the proximal end of the cannula 78 and is axially spaced from the marker 82 on the suture 74 to facilitate fluoroscopic visualization of the suture lock as it advances distally along the suture 74. The marker band 80 may be positioned between the inner and outer layers of the ePTFE cannula, such as may be created by placing the band on the cannula and flipping the cannula onto itself to capture the loop.

[0059] The suture lock guide can include any of a variety of structures, such as the cannula or alignment pin illustrated in the figure, which extends proximally from the hub and is received within the lumen of the suture lock for maintaining the orientation of the suture lock after separation from the deployment catheter. Since the tension on the suture 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 will affect the tension on the leaflets and potentially negatively impact the therapeutic value of the implant. The suture lock guide helps to maintain a constant maximum distance between the ventricular anchor and the leaflet anchor both before and after deployment from the catheter. Thus, the maximum tension (during systole) on the leaflet suture remains constant before and after catheter separation, after the suture lock has been locked.

[0060] The helical anchor assembly 50 can be delivered by the ventricular anchor delivery subsystem 300. Figures 2C to 2E Various views of the ventricular anchor delivery subsystem 300 and its components are illustrated. Figure 2C A perspective view of the distal end of the subsystem 300 is depicted. Figure 2D A perspective view of the proximal end of the subsystem 300 is depicted. Figure 2E A partially exploded view of the distal end of the subsystem 300 is depicted.

[0061] The subsystem 300 can be delivered by the delivery catheter 100. The delivery catheter 100 can be introduced into the left atrium by conventional techniques (such as by transseptal puncture through the atrium). As the various subsystems are placed within and removed from the delivery catheter 100, the delivery catheter 100 can remain in a substantially constant position throughout the procedure. For example, the distal end of the delivery catheter 100 can be positioned within the left atrium. In other embodiments, the distal end of the delivery catheter 100 can be positioned within the left ventricle throughout the duration of the procedure.

[0062] As Figures 2C to 2E shown, the ventricular anchor delivery subsystem 300 can include an outer sheath 304, a drive shaft 307 and a drive head 306, an anchor hub 308, and an anchor 302. The anchor can be a helical anchor 302, and the drive head 306 can be configured to rotate the helical anchor 302. The helical anchor 302 can include an inner diameter configured to be received on the outer diameter of the anchor hub 308. The helical anchor 302 can be securely fixed to the anchor hub 308 by an interference fit or other frictional engagement, brazing, or other known attachment techniques. The anchor hub 308 can be configured to be implanted with the helical anchor 302.

[0063] The anchor hub 308 can include a lumen that is positioned substantially along the central axis of the anchor hub 308 for receiving the suture 74( Figure 2A) and attach the suture 74 to the screw anchor 302. In some embodiments, the suture 74 may include an attachment element (e.g., a knot or washer) sized such that the diameter of the attachment element is designed to prevent the suture 74 from being pulled proximally through the lumen of the anchor hub 308. For example, the suture 74 may be knotted distally of the lumen. In some embodiments, the suture 74 may be tied to the anchor hub 308 (e.g., through the lumen, wrapped around a structure such as an outer surface or cross pin 76, as Figure 2B shown, and tied to itself).

[0064] The screw anchor 302 may include a distal segment of the wrap and a proximal segment of the wrap. The proximal segment of the wrap may be spaced closer together than the distal segment of the wrap and may be configured to secure the screw anchor 302 to the anchor hub 308. The distal segment of the wrap may be spaced farther apart than the proximal segment of the wrap and may be configured to be inserted into ventricular tissue. The anchor hub 308 may include an enlarged cross-section at its proximal end configured to abut the screw anchor 302 and / or prevent the screw anchor 302 from advancing proximally at the proximal end of the anchor hub 308. Other screw anchors, such as those described elsewhere herein, may also be configured to be used with the ventricular anchor delivery subsystem 300 described herein.

[0065] The proximal face of the screw anchor 302 may include a recess for receiving an extension 306' of the drive head 306. The recess may be non-circular (e.g., rectangular or polygonal, such as hexagonal) such that it is configured to transfer torque from the driver to the anchor hub 308 as the driver rotates. The recess may be positioned around the central lumen of the anchor hub 308.

[0066] In other embodiments, the anchor hub 308 may include an extension and the driver 309 may have a complementary recess. The drive head 306 may be generally cylindrical with a distally facing post or aperture having a complementary configuration for rotatably engaging a corresponding component on the anchor. The drive head 306 may be fixedly coupled to the drive shaft 307. The driver may include a central lumen through the drive head 306 and a drive shaft 307 configured to receive the suture 74. The central lumen of the driver may be configured to align with the central lumen of the anchor hub 308. The drive shaft 307 may be received within the guide shaft 305. The diameter of the drive head 306 may be greater than the inner diameter of the guide shaft 305. The outer sheath 304 may be sized to receive the guide shaft 305 as well as the drive head 306, the anchor hub 308, and the screw anchor 302.

[0067] The outer sheath 304 can be delivered into the left ventricle via the delivery catheter 100 and proximal to the ventricular attachment site. In some embodiments, the outer sheath 304 can be delivered without the delivery catheter. In some embodiments, the helical anchor 302 can be hidden within the outer sheath 304 until the outer sheath 304 is positioned proximal to the ventricular attachment site and then pushed distally through the outer sheath 304, or the outer sheath 304 is retracted proximally such that the helical anchor 302 is exposed. The helical anchor 302 can be placed in contact with ventricular tissue. Rotation of the drive shaft 307 can cause the drive head 306, the anchor hub 308, and the helical anchor 302 to rotate, thereby screwing the helical anchor 302 into the ventricular tissue. Rotation of the driver 309 can axially advance the driver 309, the anchor hub 308, and the helical anchor 302 in the distal direction relative to the outer sheath 304.

[0068] As Figure 2D shown, the user can manually rotate the drive shaft 307 using the drive handle 312. The proximal end of the ventricular anchor delivery subsystem 300, as Figure 2D illustrated, can include a first hemostatic valve 314 and a second hemostatic valve 316. The first hemostatic valve 314 can be positioned distal to the drive handle 312 and can provide an access path to the guide shaft 305. The second hemostatic valve 316 can be positioned proximal to the drive handle 312 and can provide an access path to the central lumen of the driver. A ventricular anchor suture (not shown) can extend through the second hemostatic valve 316.

[0069] In some embodiments, the insertion portion 306' of the drive head 306 and the recess of the anchor hub 308 can have a friction engagement that temporarily holds the two components together. Once the helical anchor 302 is inserted, the friction engagement can be overcome when the driver is retracted proximally by the reaction force from the ventricular tissue. In some embodiments, the proximal tension on the suture 74 can provide an engagement force between the proximal hub 308 and the drive head 306 that can be released when the driver 309 is retracted. The drive head 306 can be retracted proximally into the outer sheath 304 before the outer sheath 304 is withdrawn into the delivery catheter 100.

[0070] The unimplanted components of the ventricular anchor delivery subsystem 300 can be removed from the delivery catheter 100, and subsequent subsystems can be placed within the delivery catheter 100 to complete the implantation of a new chord. In a modified embodiment, the ventricular anchor delivery subsystem 300 and subsequent subsystems such as the leaflet anchor delivery subsystem 330 can be simultaneously positioned within the delivery catheter 100, and in certain arrangements, both the tissue and leaflet anchors can be pre-loaded into the delivery catheter. In an alternative embodiment, the implantation of the ventricular anchor can be performed in a different order (e.g., after the implantation of the leaflet anchor). The ventricular anchor delivery component can be retracted proximally toward the proximal end of the suture 74, the proximal end of which can remain extended through the delivery catheter 100 to the ventricular anchor 302.

[0071] Figure 3 Figures 4 through 6 depict the deployment of the leaflet anchor. Refer to Figure 3 , where the ventricular anchor 32 has been deployed and tethered to the catheter 100 via the ventricular anchor suture 74, and the ventricular anchor subsystem has been removed. The leaflet anchor is carried within the needle 338, which is shown targeting a target site on the atrial side of the leaflet. The needle 338 is axially reciprocated within the catheter 100, such as within a tubular cannula 332 that can be advanced through the catheter 100. Other details of the needle and needle driver are discussed below.

[0072] As Figure 3 shown, in the illustrated arrangement, the needle can pass from the atrium through the leaflet to the ventricle, and then the pre-loaded suture can be advanced into the ventricle. Then, as Figure 4 shown, the suture can be used to collapse the pledget against the ventricular side of the leaflet to anchor the suture to the leaflet. Thereby, the pledget forms a leaflet anchor that can radially expand. In certain embodiments, other forms of radially expandable leaflet anchors can be used.

[0073] Then, the leaflet anchor and suture can be used in combination with the ventricular anchor, suture, and suture lock to effectively create a new mitral valve chord, as Figure 5 shown. As described above, the leaflet anchor and suture can be used in combination with the systems and methods for transvascular artificial chord implantation disclosed in U.S. Patent Application 15 / 858,671, the entire contents of which are incorporated herein by reference, and with various embodiments of the ventricular anchor, suture, and suture lock disclosed therein.

[0074] Preferably, the leaflet anchor deployment subassembly is provided with a temporary anchor for capturing and stabilizing the leaflet when the tip 338 of the needle is advanced through the anchor on the target side. As Figure 3 and Figure 4Exemplarily, the distal end 400 of the delivery tube 332 or other system components carry a temporary tissue anchor, such as the helical tissue anchor 402. The anchor 402 may be similar to the ventricular anchor 54, except that the temporary anchor 402 does not have a distal barb, as it is intended to engage the leaflet only temporarily. Thus, the anchor 402 includes a helical element 406 terminating in a distal tip 408.

[0075] In use, the distal tip 408 is positioned at a target site on the surface of the 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 is used to stabilize the anchor in a manner similar to that associated with the ventricular anchor and Figure 2A and Figure 2B as discussed to prevent it from leaving the target site in response to rotation.

[0076] After the helical element 406 engages to capture the leaflet from the atrial side and 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 such that the needle tip 338 exits the ventricular side of the leaflet, as Figure 4 shown. An anchor deployment actuator, such as a pusher extending through the needle, can be utilized to deploy the anchor from the needle and into the ventricle.

[0077] See Figure 5 , the leaflet anchor can be a pledget 340 similar to the pledgets described elsewhere herein. The pledget 340 can be coupled or attached to the distal end of the leaflet anchor suture 344. The pledget can include a soft and / or flexible material, such as a fabric. The suture 344 can extend through the needle 336. The pledget 340 can be folded or compressed in a configuration including a reduced radial cross-section such that it can be disposed within the needle 336 for delivery, as discussed below Figure 8 and Figure 10 shown. When deployed from the distal end of the needle tip 338, the pledget 340 can expand from the reduced cross-section to present a larger radial cross-section, as Figure 5 shown. In some embodiments, the pledget 340 can be pushed through the needle 336 via a push wire or release wire (not shown). After delivery through the needle tip 338, proximal retraction of the leaflet suture 344, as shown in FIG. 6, can cause the leaflet anchor to assume an axially collapsed, radially expanded configuration that prevents the leaflet anchor from retracting through the perforation in the leaflet, thereby anchoring the leaflet suture 344 to the leaflet, as Figure 7 shown.

[0078] Figures 6A to 6DThe padding 340 is schematically depicted connected to the distal end of the leaflet suture 344. The padding 340 can include two wings 341, 342 that can be rolled / folded about the longitudinal axis of the padding 340 (e.g., both in a clockwise or counterclockwise direction) to form a reduced cross-sectional configuration. In some embodiments, the leaflet suture 344 can be formed integrally with the padding 340. To create a foldable or collapsible configuration, the suture 344 can extend distally through the padding, loop around the distal end of the padding, and return proximally and back through one or more orifices (e.g., two orifices, three orifices, four orifices, etc.) formed in the padding 340, such as Figure 6A In some embodiments, the orifice can be aligned along the center of the wadding 340 .

[0079] The orifice can extend through the wadding 340 and through the portion of the embedded portion of the suture 344 that is integral with the wadding 340. The embedded portion of the suture 344 can be at least partially flattened within the wadding 340. In some embodiments, the orifice can be placed substantially near the center of the wadding (e.g., immediately to the left or right of the embedded suture 344 or alternating between the left and right sides of the suture 344). When deployed, the suture 344 can be effectively coupled to the distal end of the wadding 340 (e.g., the suture 344 can be looped back to the position where it is inserted between the wadding pieces).

[0080] Figures 6B to 6D An example of a wadding as described elsewhere herein is schematically depicted. Figure 6B Schematically depicted is a wadding 340 formed by securing the distal end of a suture 344 (shown in phantom) between two flat sheets such that the sheet is for a left wing 341 and a right wing 342 . Figure 6C The filling 340 is shown along Figure 6B Cross section of the BB axis of the example. In some embodiments, the suture 344 can be inserted between the two sheets (e.g., substantially along the middle of the sheet) and extruded and / or laminated to connect the three components together (e.g., under heat and / or pressure). At least one layer can be partially sintered. The suture 344 can be flattened and / or compacted to increase resistance to suture tearing. The sheet can be a flat polytetrafluoroethylene (PTFE) sheet (e.g., a thin uncured expanded PTFE (ePTFE) sheet) or any other suitable material. In some embodiments, the leaflet suture 344 can be arranged between the sheets in an alternative configuration such as a zigzag or s-shaped configuration. Figure 6D Shows Figure 6B The wadding 340 includes a plurality of apertures 343 through which the proximal ends of the sutures 344 may pass.

[0081] In some embodiments, one or more orifices 343 may be formed through the pledget in various configurations to form a collapsible structure as described elsewhere herein, the collapsible structure being configured to anchor suture 344 against the mitral valve leaflets. Figure 6D Orifices 343 are shown alternating on opposite sides of suture 344. In some embodiments, orifices 343 may be formed on the same side of suture 344 (e.g., in flange 341 or flange 342). In some embodiments, orifices 343 may be formed through suture 344. Orifices 343 may be centered along the pledget 340. Orifices 343 may be aligned along the length of suture 344 (e.g., may form a straight line). Suture 344 may be at least partially flattened between two opposing sheets, which may facilitate the placement of orifices 343 through suture 344. Various combinations of orifices 343 including the above-described positioning may be used.

[0082] The pledget 340 may be formed such that flanges 341, 342 have substantially the same dimensions, or they may be formed to have different dimensions. When the leaflet suture 344 is retracted proximally, the pledget 340 may be folded to present an accordion-like configuration, as Figure 6A depicted. The pledget 340 may present a configuration including a substantially planar proximal surface that is generally perpendicular to the longitudinal axis of the leaflet suture 344. This configuration may facilitate the anchoring of suture 344 in the leaflet. When anchoring the leaflet suture 344 in the leaflet, the leaflet anchor delivery subsystem 340 may be withdrawn from the delivery catheter 100. The leaflet anchor delivery component may be retracted proximally at the proximal end of suture 344, the proximal end of which may remain adjacent to the ventricular anchor suture 74 and extend through the delivery catheter 100 to the leaflet anchor 340.

[0083] Figures 8 to 10 Illustrates various views of the leaflet anchor delivery subsystem 330 and its components. Figure 8 A perspective view of the distal end of the subsystem 330 is depicted. Figure 9 A perspective view of the proximal end of the subsystem 330 is depicted. Figure 10 An exploded view of the distal end of the subsystem 330 is depicted.

[0084] As Figure 8 and Figure 10 shown, the leaflet anchor delivery subsystem 330 may include an outer delivery tube 332. The tube 332 may optionally include a deflection region and may be configured to be manipulable by an operator, such as by one or two or more pull wires (not shown) retracting proximally along respective sides of the curved tube 332. The operator may control the bending of the curved tube via a knob 352 or lever or other actuation mechanism located on a handle 350 at the proximal end of the leaflet anchor delivery subsystem 330, asFigure 9 as shown

[0085] An internal tubular shaft or needle 336 that terminates at a tip 338 at the distal end can extend through a delivery tube 332. The internal needle 336 can include a hypotube, an extruded tube, a braided tube, or a catheter that has sufficient flexibility to conform to the shape of the optional curved tube 332. The tip 338 can be coupled to the distal end of the internal flexible shaft 336. A flexible jacket 333 can surround the curved tube 332 and the delivery shaft 334.

[0086] The proximal end of the internal tubular shaft 336 can be connected to a needle handle 354, as Figure 9 shown. The needle handle 354 can include a hemostatic valve 356. A leaflet suture 344 can be inserted through the valve 356. The valve 356 can be a Tuohy-Borst valve. The needle handle 354 can include an additional port 358 for accessing the lumen of the internal flexible shaft 336. The needle handle 354 can be positioned proximal to the handle 350 such that the internal flexible shaft 336 extends through the handle 350 and into the lumen of the delivery shaft 334. The handle 350 can include a hemostatic valve that receives the internal flexible shaft 336 and seals off the internal components of the handle, including the opening to the delivery shaft 334, from the surrounding environment.

[0087] The tip 338 can be capable of extending and retracting by respectively extending the needle handle 354 towards the handle 350 or retracting the needle handle 354 from the handle 350. The distal advancement of the needle 336 can be achieved by manually advancing the handle 354. Alternatively, the distal advancement of the needle can be assisted by a mechanical or electromechanical mechanism to produce a relatively high speed, low stroke length distal advancement.

[0088] Applying pressure to the leaflet when the tip 338 extends distally beyond the tube 332 can cause the tip 338 to pierce the leaflet such that the tip 338 can extend through to the opposite side of the leaflet (e.g., the atrial side), as Figure 4 shown. The pressure can be applied by extending the tip 338 and / or retracting the entire delivery device 330 in the proximal direction with the tip 338 in the extended position.

[0089] The ventricular anchor suture 74 and the leaflet anchor suture 344 can be joined together in a tensioned manner to form a new chord implant or to join two segments of a new chord implant such that the new chord extends across the atrial side of the junction edge of the leaflet between the ventricular anchor 302 and the leaflet anchor 340. The total length of the new chord can be adjusted by retracting one or both sutures 74, 344 proximally prior to engaging the suture lock 376 such that appropriate tension is applied to the leaflet, where the tension is then maintained by the ventricular anchor 302. The sutures 74, 344 can remain extending proximally through the delivery catheter 100 to a location outside the body. In some embodiments, the proximal ends of the sutures 74, 344 can 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 can remain free or be joined or secured by other means.

[0090] Figure 11 Depicts the advancement of the suture lock 376 over the ventricular anchor suture 74 and the leaflet suture 344. The suture lock delivery subsystem 370 can be advanced through the delivery catheter 100 and the tubular pusher catheter 372 can push the suture lock 376 along the distal direction of the sutures 74, 344. Once the suture lock 376 reaches the ventricle, it can continue to be pushed along the ventricular suture 74 with proximal traction on the suture 74 and at the same time allow the leaflet suture 344 to be fed distally through the catheter as needed to advance the suture lock 376 distally to the ventricular anchor. As discussed further below, Figure 12 Illustrates the final configuration where the leaflet anchor and the ventricular anchor are tethered together to form an artificial chord. The proximal tails of the two sutures have been cut and the catheter has been retracted proximally from the ventricle through the mitral valve.

[0091] Figures 13 to 14 Illustrates various views of the suture lock delivery subsystem 370 and its components. Figure 13 Depicts a perspective view of the distal end of the subsystem 370. Figure 14 Depicts a perspective view of the proximal end of the subsystem 370. Figure 15 Depicts a partially exploded view of the distal end of the subsystem 370. Figure 16 Depicts a perspective view of the distal end of the cutting assembly. Figure 17 and Figure 18 Depicts a side view of the cutting assembly portion of the subsystem 370. Figure 19 Depicts a side view of the distal ends of the suture lock 376 and the torque driver 388 configured to engage the suture lock 376. Figure 20 and Figure 21 Depicts a proximal view and a distal view of the suture lock 376, respectively.

[0092] The suture lock delivery subsystem 370 can be configured to advance (e.g., slide) a suture lock 376 over two sutures 74, 344 (and even three or four or additional sutures) to secure them together. The sutures 74, 344 can 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 respective tissue anchors 302, 340. Once the tension and length of the new chordal implant are optimized, the suture lock 376 can be locked to secure the length of the sutures 74, 344 such that the sutures 74, 344 can no longer move relative to the suture lock 376. The sutures 74, 344 can 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 delivered the suture lock 376. In other embodiments, a separate cutting device can be inserted into the delivery catheter 100 after the suture lock is locked in place.

[0093] The suture lock allows one or two or more sutures to be advanced through the suture lock and adjusted and then locked with sufficient clamping efficiency such that the ePTFE sutures are prevented from sliding out of the suture lock under normal use conditions (e.g., withstand a tension of at least about 60% or 80% or greater of the suture break strength without sliding). The lock can be reopened to allow readjustment of the tension on the mitral valve leaflets and retightened until the desired result has been achieved. The tightening tool can then be removed, leaving the suture lock.

[0094] The suture lock 376 can be advanced along the suture by holding catheter 373. The distal end of the holding catheter 373 can be coupled to a holding element 377( Figure 15 ). The holding 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 at the proximal end of the suture lock 376. In some embodiments, rotation of the holding catheter 373 and / or translation substantially perpendicular to the axial direction of the holding catheter 373 can be used to disengage the holding catheter 373 from the suture lock 376.

[0095] The sutures 74, 344 can extend from their respective tissue anchors to pass through the suture lock 376 to enter through a distal opening 395 in the distal face of the suture lock 376( Figure 21 shown therein), and exit at a proximal opening 394 to a suture path in the proximal face of the suture lock 376( Figure 20(shown in). The sutures 74, 344 can extend through a channel in the cutting head 375 proximal to the suture lock 376, and extend along the outside of the retention catheter 373 and through the delivery catheter 100. The cutting head 375 can be coupled to the distal end of the cutting catheter 372. The retention catheter 373 can extend through the inner lumen of the cutting catheter 372 such that the two catheters 372, 373 can extend or retract relative to each other.

[0096] Once the sutures 74, 344 are locked (securely fixed) within the suture lock 376, the proximal ends of the sutures 74, 344 can be cut adjacent to the proximal face of the suture lock. The sutures 74, 344 can be cut by advancing the cutting catheter 372, which is coupled to the cutting head 375, toward the proximal face of the suture lock 376. As Figures 17 to 18 schematically illustrated, as the cutting head 375 advances along the retention catheter 373 toward the retention element 377, the cutting head brings the sutures 74, 344 into close proximity to the cutting blade 379 positioned on the retention element 377. The cutting head 375 is configured to advance on the retention element 377 in such a way that the channels in the cutting head 375 that hold the sutures 74, 344 become increasingly spatially occupied by the blade 379. When the blade 379 is forced into the channels of the cutting head 375, the blade 379 severs the sutures 74, 344. Applying a proximal tension to the sutures 74, 344 can facilitate the cutting of the sutures 74, 344. In other embodiments, different actuation (e.g., rotation of the cutting catheter) can be configured to sever the sutures 74, 344.

[0097] In some embodiments, more than two sutures can be employed, and these sutures can be locked within the suture lock 376 and severed in the same manner by the suture lock delivery subsystem 370. In some embodiments, the advancement of the cutting head 375 on the retention element 377 can facilitate the detachment of the retention catheter 373 from the suture lock 376. For example, the cutting head 375 can be advanced to a distal position where the cutting head 375 is configured to stabilize the suture lock 376 to allow the retention catheter 373 to axially and / or rotationally disengage from the suture lock 376.

[0098] Figure 19Side view of an example of a suture lock 376 (shown with its outer housing / shell removed). A suture can pass through the suture lock 376 from the distal end to the proximal end, as described elsewhere herein. The suture lock 376 can include a screw 382 configured to advance a push wedge 384 distally or retract it proximally depending on the direction of rotation of the screw. The screw 382 can be rotated by a torque shaft 388. The torque shaft 388 can include a drive head configured to mate with a recess 381 (e.g., a polygonal recess or other non-circular recess, such as Figure 20 shown) located at the proximal end of the suture lock 376 such that rotation of the torque shaft 388 causes rotation of the screw 382. The torque shaft 388 can extend through the inner lumen of a holding 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, sutures 311, 344 can pass through the hemostatic valve 397.

[0099] Advancing the push wedge 384 by the torque shaft 388 can gradually compress one or more springs, such as spring pins 388, against a ramp or angled surface 386. The springs bias the clamp upward to open the suture path until forced closed by rotation of the torque shaft 388. Compression of one or more spring pins 388 can force the clamp 390 downward onto the sutures 311, 344, thereby compressing the sutures 311, 344 between two opposing surfaces. In some embodiments, the clamp 390 and the opposing surface 392 can have notched surfaces configured to mate with each other in discrete increments. The mating notched surfaces can provide enhanced friction and, in some embodiments, mechanical interference for holding the sutures 311, 344 between the opposing surfaces such that they cannot be withdrawn proximally or distally from the suture lock 376. In some embodiments, tightening can be reversible by rotating the torque shaft in the opposite direction.

[0100] Once the suture lock is properly positioned on the sutures 74, 344 and locked in place, the sutures 74, 344 can be cut as described elsewhere herein. Figure 12 Depiction of the retraction of the suture lock delivery subsystem 370 after the sutures 74, 344 have been cut. Once the suture lock delivery subsystem 370 has been removed from the delivery catheter 100, the delivery catheter 100 can be withdrawn from the body.

[0101] Although the disclosure describes certain embodiments and examples, many aspects of the above systems and methods can be combined and / or modified differently to form additional embodiments or acceptable examples. All such modifications and variations are intended to be included within the scope of the disclosure. Indeed, a wide variety of designs and methods are possible and within the scope of the disclosure.

[0102] In addition, certain features described in the disclosure in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, the various features described in the context of a single embodiment can also be implemented separately or in any suitable sub-combination in multiple embodiments. Moreover, although the features may be described above as acting in certain combinations, one or more features from the claimed combination can in some cases be excised from the combination, and the combination can be claimed as a sub-combination or a variation of the sub-combination.

[0103] Any particular feature, aspect, method, performance, characteristic, quality, property, element, etc. disclosed herein in connection with various embodiments can be used in all other embodiments set forth herein. Moreover, any method described herein can be practiced using any device suitable for performing the described steps.

[0104] Moreover, although 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, nor need they be arranged and performed in sequential order, nor need all components and operations be included to achieve the desired result. Other components and operations not depicted or described can be incorporated in the embodiments and examples. For example, one or more additional operations can be performed before, after, simultaneously with, or between any of the described operations. Further, in other embodiments, the operations can be rearranged or reordered. Moreover, the separation of the various system components in the above embodiments should not be understood as requiring such separation in all embodiments, and it should be understood that the components and systems can generally be integrated together in a single product or packaged into multiple products.

[0105] In summary, various illustrative embodiments and examples are described herein. Although systems and methods have been disclosed in the context of these embodiments and examples, the disclosure extends beyond the specifically disclosed embodiments to other alternative embodiments and / or other uses of the embodiments, and to certain modifications and equivalents thereof. The disclosure expressly contemplates that the various features and aspects of the disclosed embodiments can be combined or substituted for one another. Accordingly, the scope of the disclosure should not be limited by the specifically disclosed embodiments above, but should be determined only by a reasonable reading of the appended claims and their full scope of equivalents.

Claims

1. A small leaflet anchoring delivery subsystem, comprising: An elongate flexible tubular body having a proximal end, a distal end, and a central lumen; A deployment needle axially movably advanced through the central lumen; A collapsible fluffed small leaflet anchor carried within the deployment needle; And A small leaflet connector positionable at the distal end of the elongate flexible tubular body.

2. The lobular anchor delivery subsystem according to claim 1, wherein The small leaflet connector is configured to engage the mitral valve leaflets from the atrial side of the mitral valve leaflets.

3. The small leaf anchor delivery subsystem according to claim 1, characterized in that The deployment needle is configured to be advanced through the small leaflet connector.

4. The small leaf anchor delivery subsystem according to claim 1, wherein The small leaflet connector includes tissue hooks.

Images