Patent Description:
The present disclosure relates to mitral valve repair or replacement and more generally to methods and methods and devices for mitral valve reshaping, repair and/or replacement of mitral chords to restore proper functioning of the mitral valve from a state of mitral valve regurgitation.

The heart includes four heart valves, which allow blood to pass through the four chambers of the heart in one direction. The four valves are the tricuspid, mitral, pulmonary and aortic valves. The four chambers are the right and left atria (upper chambers) and right and left ventricle (lower chambers).

The mitral valve is formed by two leaflets, which are known as the anterior leaflet and the posterior leaflet, which open and close in response to pressure placed on the leaflets by the pumping of the heart. There are several problems that can develop or occur with respect to the mitral valve. Such problems include mitral valve regurgitation (MR), in which the mitral valve leaflets do not close properly, which can cause leakage of the mitral valve. Severe mitral regurgitation can adversely affect cardiac function and compromise a patient's quality of life and life-span.

Several techniques have been developed, for correcting mitral valve regurgitation. These include heart transplant, valve replacement or repair, chordae tendinea shortening or replacement and mitral annular repair also known as annuloplasty, depending upon the stage and underlying etiology.

As it relates to chordae tendinea replacement or repair, certain surgical and trans apical approaches have been proposed. Despite those efforts, however, there remains a need for a transvascular approach for chordae tendinea replacement or repair, to reduce or eliminate MR.

<CIT> discloses a neo chordae tendinae deployment system, comprising a catheter, a helical ventricular anchor subassembly extendable through the catheter with a ventricular suture extending proximally through the catheter; and a leaflet anchor deployment subassembly extendable through the catheter, with a radially enlargeable leaflet anchor within the subassembly and having a leaflet suture extending proximally through the catheter.

An aspect of the disclosure includes a method of transvascular prosthetic chordae tendinae implantation, 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 a wall of the left ventricle, leaving a ventricular suture attached to the ventricular anchor and extending proximally through the catheter; from an atrium side, advancing a leaflet anchor through a superior surface of a mitral valve leaflet to position a leaflet anchor against the inferior (ventricular) side of the leaflet with a leaflet suture extending proximally through the leaflet, into and through the catheter; and securing the leaflet suture over the top of the leaflet coaptive edge to the ventricular suture to limit a range of travel of the leaflet in the direction of the left atrium.

Another aspect of the disclosure is a leaflet anchor deployment system, comprising: a catheter having a proximal end and a distal end; a leaflet anchor positioned on a distal end of the catheter; and a needle advanceable through the leaflet anchor, the needle releasably carrying a radially enlargeable leaflet anchor preloaded therein and having a suture extending proximally through the catheter.

In accordance with another aspect of the disclosure there is provided a method of transvascular prosthetic chordae tendinae implantation. 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 a wall of the left ventricle, leaving a ventricular suture attached to the ventricular anchor and extending proximally through the catheter; from an atrium side, securing a leaflet anchor catheter to a mitral valve leaflet; with the leaflet anchor catheter secured to the leaflet, advancing a leaflet anchor from the catheter through the mitral valve leaflet to secure the mitral valve leaflet to a leaflet suture, with the leaflet suture extending proximally through the catheter; and securing the leaflet suture to the ventricular suture to limit a range of travel of the leaflet in the direction of the left atrium.

The step of advancing a leaflet anchor from the catheter through the mitral valve leaflet to secure the mitral valve leaflet to a leaflet suture may comprise advancing a needle preloaded with the leaflet anchor through the superior surface of the mitral valve leaflet. The securing a leaflet anchor catheter to a mitral valve leaflet step may comprise using a leaflet connector. The leaflet connector may comprise a helical anchor or a tissue hook.

In accordance with another aspect of the disclosure there is provided a method of securing a leaflet anchor to a mitral valve leaflet. The method comprises the steps of advancing a catheter into the left atrium; from an atrium side, securing a leaflet connector coupled to the catheter to a mitral valve leaflet from an 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 a leaflet suture.

The step of advancing a leaflet anchor through the mitral valve leaflet to secure the mitral valve leaflet to a leaflet suture may comprise advancing a needle preloaded 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 comprise a helical anchor.

In accordance with another aspect of the disclosure there is provided a leaflet anchor deployment system. The system comprises a catheter having a proximal end and a distal end; a leaflet connector positioned on a distal end of the catheter; and a needle advanceable through the leaflet connector, the needle including a radially enlargeable leaflet anchor preloaded therein and having a suture extending proximally through the catheter. The leaflet connector may comprise a helical anchor.

In accordance with the invention there is provided a neo chordae tendinae deployment system. The system comprises the features of claim <NUM>, amongst others: a catheter having a proximal end and a distal end; a helical ventricular anchor subassembly extendable through the catheter, having a ventricular suture extending proximally through the catheter; and a leaflet anchor deployment subassembly extendable through the catheter, having a radially enlargeable leaflet anchor within the subassembly and having a leaflet suture extending proximally through the catheter. Further embodiments of the invention are recited in the dependent claims.

The radially enlargeable leaflet anchor may comprise a pledget. The pledget may be transformable from an elongate strip configuration to a radially enlarged, axially shortened configuration by proximal retraction of the suture. The radially enlargeable leaflet anchor may comprise the leaflet suture positioned between two sheets of material. The radially enlargeable leaflet anchor may be carried within a needle having a sharpened end for piercing the leaflet. The leaflet anchor deployment subassembly may comprise an elongate tube having a distal end and a central lumen, and a leaflet connector on the distal end. The leaflet connector may comprise a helical leaflet anchor. The needle may be axially movable with respect to the helical leaflet anchor. The system may further comprise a suture locking subassembly, advanceable through the catheter and configured to connect the ventricular suture to the leaflet suture.

In accordance with another aspect of the disclosure there is provided a leaflet anchor delivery subsystem. The subsystem comprises an elongate flexible tubular body, having a proximal end, a distal end and a central lumen; a deployment needle axially movably advancable 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 comprise a helical element. The deployment needle may be axially extendable through the helical element.

In accordance with another aspect of the disclosure there is provided a tissue anchor. The tissue anchor comprises a hub; a suture extending proximally from the hub; a helical anchor extending distally from the hub; a core wire extending concentrically through the helical anchor, and beyond the distal end of the helical anchor.

The tissue anchor may further comprise a suture anchor guide extending proximally from the hub. The tissue anchor may further comprise a tubular sleeve having a length of no more than about <NUM> extending proximally from the hub. The tissue anchor may further comprise a radiopaque marker carried by the sleeve. The tissue anchor may further comprise a radiopaque marker axially movably carried by the core wire. The tissue anchor may further comprise a spring carried by the core wire. The tissue anchor may further comprise a tissue piercing point on a distal end of the helical anchor, and a barb on the helical anchor configured to resist rotation of the helical anchor out of engagement with tissue.

In accordance with another aspect of the disclosure there is provided a tissue anchor with dynamic depth indicator. The tissue anchor comprises 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 a distal direction; wherein the radiopaque marker is advanced proximally with respect to the tissue anchor in response to the tissue anchor advancing into tissue.

In accordance with another aspect of the disclosure there is provided an endovascular suture lock. The suture lock comprises a body having a suture path extending therethrough; a movable wall in the housing, for reducing a cross sectional dimension of the suture path; a rotatable coupling on the housing; and a drive mechanism for advancing the movable wall in response to rotation of the coupling.

The suture lock may additionally comprise a friction enhancing surface exposed to the suture path. The friction enhancing surface may be on the movable wall. The suture lock may comprise a push wedge having an angled surface and axially movable within the housing. Rotation of the coupling may advance the push wedge axially which advances the movable wall laterally to change the cross sectional dimension of the suture path. The movable wall may comprise a suture gripping surface on a first side and a ramp surface on a second side, the ramp surface configured for sliding contact with the angled surface on the push wedge.

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. Understanding that these drawings depict only several embodiments in accordance with the disclosure and are not to be considered limiting on scope.

<CIT> discloses systems and methods for the transvascular prosthetic chordae tendinae implantation. 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 a 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 a mitral valve leaflet to secure the mitral valve leaflet to a leaflet suture, with the leaflet suture extending proximally through the catheter, and extending the leaflet suture over the top of the coaptive edge and securing the leaflet suture to the ventricular suture to limit a range of travel of the leaflet in the direction of the left atrium. Certain aspects are developed further herein.

The approach to the mitral valve can be accomplished through a standard transceptal approach to provide access to the left atrium. With this access, a first step can include securing a leaflet capture catheter to the leaflet of the mitral valve in the location determined to best correct regurgitation. Probing the surface of the leaflet from the superior atrium surface can advantageously provide immediate feedback as to the optimal location to add an additional mitral valve chord. In another implementation of the disclosure, the ventricular anchor is deployed first, followed by deployment of the leaflet anchor.

Referring to <FIG>, a ventricular anchor such as a helical anchor <NUM> has been deployed near the apex <NUM> of the left ventricle <NUM>. While the helical anchor <NUM> is shown positioned near the apex <NUM> in the following Figures, the anchor <NUM> can be attached at a point that is offset from the thin tissue of the apex, and can be instead implanted in the generally thicker adjacent wall of the ventricle, such as between the two papillary muscles. This allows the implanted neo chord construct (suture, optional neo papillary muscle, and/or the helical anchor) to be aligned along a longitudinal axis substantially parallel to or concentric with the original path of the native chord. In certain embodiments, the implanted neo chord construct is aligned along a longitudinal axis that is within <NUM> degrees, <NUM> degrees, or <NUM> degrees of being parallel with the original path of the native chord and/or the path of the adjacent native chord. In addition, while a helical anchor is illustrated the anchor can have a different structure for engaging tissue of the heart and thus other tissue anchor structures can be used instead of a helical structure including various piercing, hook or radially expandable structures known for engaging tissue.

Referring to <FIG>, there is illustrated one implementation of a tissue anchor suitable for use as a ventricular anchor in accordance with the present disclosure.

The anchor assembly <NUM> will be described primarily in the context of the present chordae repair application, however the anchor may be utilized in any of a wide variety of other applications where a soft tissue or bone anchor may be desired.

The anchor assembly <NUM> generally comprises a coil <NUM> which may comprise any of a variety of materials such as stainless steel or Nitinol. The coil <NUM> extends helically between a proximal end <NUM> and a distal end <NUM>. Distal end <NUM> is provided with a sharpened tip <NUM>, and also carries a retention barb <NUM>, configured to resist reverse rotation of the coil and detachment from tissue. The proximal end <NUM> of the coil <NUM> is carried by (attached to or formed integrally with) a hub <NUM> discussed in additional detail below.

Extending distally from the hub <NUM> and within the coil <NUM> is an elongate core wire <NUM> having a sharp, tissue piercing distal end <NUM>. The distal end <NUM> is positioned distally of the distal end <NUM> of the coil <NUM>. This enables the sharp distal end <NUM> to pierce tissue upon contact, and prior to beginning rotation of the coil <NUM> to embed the coil <NUM> within the target tissue. Engaging the tip <NUM> prior to rotation of the anchor stabilizes the anchor against sideways movement allowing a single placement of the anchor <NUM> against tissue, and rotation of the coil <NUM> to engage tissue, without 'walking' of the anchor away from the desired target site as will be understood by those of skill in the art. A proximal end of the core wire <NUM> may be attached to the hub in any of a variety of ways, such as by soldering, brazing, adhesives and / or mechanical interference such as by entering an aperture in a sidewall or other surface of the hub <NUM>.

A radiopaque depth marker <NUM> is provided with an aperture <NUM> and is axially movably carried on the core wire <NUM>. A distal stop <NUM> such as a radially outwardly extending protrusion or annular ridge is carried by the core wire <NUM>, and spaced proximally of the sharpened distal end <NUM> to provide a core wire leading segment <NUM> on the distal side of the stop <NUM> so that the marker <NUM> cannot interfere with the tissue anchoring function of the distal tip <NUM>. The stop <NUM> functions to limit distal travel of the marker <NUM>. The marker <NUM> may be an annular structure such as a circular disc with a central aperture to receive the core wire <NUM>.

A coil spring <NUM> is concentrically carried over the core wire <NUM> and biases the radiopaque marker <NUM> in the distal direction. The radiopaque marker <NUM> is thus held in position against a proximal surface of the stop <NUM>. In use, the marker <NUM> rides on the surface of tissue at the target attachment site. As the helical coil anchor <NUM> is rotated and advances distally into tissue, the marker <NUM> rides proximally on the core wire <NUM> along with the tissue surface, compressing the coil spring <NUM> until the marker <NUM> is retracted proximally to the hub when the tissue anchor is fully embedded. This enables fluoroscopic visualization of the progress of the coil into tissue and of the fully engaged end point of embedding the coil <NUM> into the target tissue, by observing the changing distance between marker <NUM> and a reference such as the hub <NUM> or other radiopaque marker.

The hub <NUM> comprises a proximal connector for engagement with a rotational driver as discussed elsewhere herein. In one implementation, the connector comprises an aperture such as a hexagonal aperture for removably engaging a complementary surface structure on the distal end of the driver. A suture <NUM> is secured to the anchor assembly <NUM>, for example secured to the hub <NUM>, coil <NUM> or core wire <NUM>. In the illustrated embodiment, the suture <NUM> is attached to a cross pin <NUM> which may be inserted through one or two apertures in the sidewall of the hub and across a central hub lumen. The suture may additionally carry one or two or more radiopaque markers <NUM> spaced apart from the hub <NUM>, and may extend proximally through the proximal connector and a central lumen in the rotational driver.

A suture lock guide such as a tubular sleeve <NUM> extends proximally from the hub <NUM> for at least about <NUM> or <NUM> or <NUM> but generally no more than about <NUM> or <NUM> depending upon desired performance. The guide sleeve <NUM> may comprise a flexible material such as ePTFE. Preferably a radiopaque marker band <NUM> is carried by the proximal end of sleeve <NUM> and spaced axially apart from the marker <NUM> on suture <NUM>, to facilitate fluoroscopic visualization of the suture lock as it is advanced distally over the suture <NUM>. The marker band <NUM> may be positioned in between an inner layer and an outer layer of ePTFE sleeve, such as may result from placing the band over the sleeve and inverting the sleeve over itself to entrap the ring.

The suture lock guide may comprise any of a variety of structures such as a sleeve as illustrated or an alignment pin extending proximally from the hub and received within a lumen in the suture lock, for maintaining the orientation of the suture lock following detachment 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 following release from the catheter would affect tension on the leaflet and potentially negatively affect the therapeutic value of the implant. The suture lock guide helps maintain constant the maximum distance between the ventricular anchor and the leaflet anchor both pre and post deployment from the catheter. In this manner the maximum tension on the leaflet suture (during systole) remains unchanged after the suture lock has been locked, both before and after detachment of the catheter.

The helical anchor assembly <NUM> may be delivered by a ventricular anchor delivery subsystem <NUM>. <FIG> illustrate various views of a ventricular anchor delivery subsystem <NUM> and its components. <FIG> depicts a perspective view of a distal end of the subsystem <NUM>. <FIG> depicts a perspective view of a proximal end of the subsystem <NUM>. <FIG> depicts a partially exploded view of a distal end of the subsystem <NUM>.

The subsystem <NUM> may be delivered through the delivery catheter <NUM>. The delivery catheter <NUM> may access the left atrium through conventional techniques, such as through an atrial trans-septal puncture. The delivery catheter <NUM> may be maintained in a substantially constant location throughout the procedure as various subsystems are placed and removed from the delivery catheter <NUM>. For instance, the distal end of the delivery catheter <NUM> may be positioned in the left atrium. In other implementations, the distal end of the delivery catheter <NUM> may be positioned in the left ventricle throughout the duration of the procedure.

As shown in <FIG>, the ventricular anchor delivery subsystem <NUM> may comprise an outer sheath <NUM>, a driver (comprising shaft <NUM> and head <NUM>), an anchor hub <NUM>, and an anchor <NUM>. The anchor may be a helical anchor <NUM> and the drive head <NUM> can be configured to rotate the helical anchor <NUM>. The helical anchor <NUM> may comprise an inner diameter configured to be received over the outer diameter of an anchor hub <NUM>. The helical anchor <NUM> may be securely fixed secured to the anchor hub <NUM> by an interference fit or other frictional engagement, soldering or other known attachment technique. The anchor hub <NUM> may be left implanted along with the helical anchor <NUM>.

The anchor hub <NUM> may comprise a lumen positioned substantially along a central axis of the anchor hub <NUM> for receiving a suture <NUM> (<FIG>) and attaching the suture <NUM> to the helical anchor <NUM>. In some embodiments, the suture <NUM> may comprise an attachment element (e.g. a knot or a washer) with a diameter sized to prevent the suture <NUM> from being pulled proximally through the anchor hub <NUM> lumen. For example, the suture <NUM> may be knotted on a distal side of the lumen. In some embodiments, the suture <NUM> may be tied to the anchor hub <NUM> (e.g., passed through the lumen, wrapped around a structure such as the outer surface or a cross pin <NUM> as shown in <FIG>, and tied to itself).

The helical anchor <NUM> may comprise a distal section of windings and a proximal section of windings. The proximal section of windings may be spaced closer together than the distal section of windings and may be configured for securing the helical anchor <NUM> to the anchor hub <NUM>. The distal section of windings may be spaced further apart than the proximal section of windings and may be configured for insertion into the ventricular tissue. The anchor hub <NUM> may comprise an enlarged cross-section at its proximal end configured to abut the helical anchor <NUM> and/or prevent the helical anchor <NUM> from advancing proximally over the proximal end of the anchor hub <NUM>. Other helical anchors, such as those described elsewhere herein, may be configured to be used with the ventricular anchor delivery subsystem <NUM> described herein as well.

The proximal face of the helical anchor <NUM> may comprise a recess for receiving an extending portion <NUM>' of the driver head <NUM>. The recess may be non-circular (e.g., oblong or polygonal such as hexagonal) such that it is configured to transfer torque from the driver to the anchor hub <NUM> upon rotation of the driver. The recess may be positioned around the central lumen of the anchor hub <NUM>.

In other embodiments, the anchor hub <NUM> may comprise an extending portion and the driver <NUM> may have a complementary recess. The driver head <NUM> may be generally cylindrical, with a distally facing post or aperture with a complementary configuration to rotationally engage the corresponding component on the anchor. The driver head <NUM> may be fixedly coupled to a drive shaft <NUM>. The driver may comprise a central lumen through the driver head <NUM> and drive shaft <NUM> configured to receive the suture <NUM>. The central lumen of the driver may be configured to be aligned with the central lumen of the anchor hub <NUM>. The drive shaft <NUM> may be received within a guide shaft <NUM>. The diameter of the driver head <NUM> may be larger than the inner diameter of the guide shaft <NUM>. The outer sheath <NUM> may be sized to receive the guide shaft <NUM> as well as the driver head <NUM>, the anchor hub <NUM>, and the helical anchor <NUM>.

The outer sheath <NUM> may be delivered into the left ventricle and proximal to the ventricular attachment site via the delivery catheter <NUM>. In some embodiments, the outer sheath <NUM> may be delivered without a delivery catheter. In some implementations, the helical anchor <NUM> may be concealed within the outer sheath <NUM> until the outer sheath <NUM> is positioned proximal to the ventricular attachment site then pushed distally through the outer sheath <NUM> or the outer sheath <NUM> is proximally retracted so that the helical anchor <NUM> is exposed. The helical anchor <NUM> may be placed into contact with the ventricular tissue. Rotation of the drive shaft <NUM> may cause the driver head <NUM>, the anchor hub <NUM>, and the helical anchor <NUM> to rotate thereby screwing the ventricular anchor <NUM> into the ventricular tissue. Rotation of the driver <NUM> may axially advance the driver <NUM>, anchor hub <NUM>, and helical screw <NUM> in a distal direction with respect to the outer sheath <NUM>.

The drive shaft <NUM> may be rotated manually by a user using a drive handle <NUM>, as shown in <FIG>. The proximal end of the ventricular anchor delivery subsystem <NUM>, as illustrated in <FIG>, may comprise first and second hemostasis valves <NUM>, <NUM>. The first hemostasis valve <NUM> may be positioned distal to the drive handle <NUM> and may provide access to the guide shaft <NUM>. The second hemostasis valve <NUM> may be positioned proximal to the drive handle <NUM> and may provide access to the central lumen of the driver. The ventricular anchor suture (not shown) may extend through the second hemostasis valve <NUM>.

In some implementations, the inserting portion <NUM>' of the driver head <NUM> and the recess of the anchor hub <NUM> may have a frictional engagement that transiently holds the two components together. The frictional engagement may be overcome upon proximal retraction of the driver by a counter force from the ventricular tissue once the helical anchor <NUM> is inserted. In some implementations, proximal tension on the suture <NUM> may provide an engagement force between the proximal hub <NUM> and the driver head <NUM>, which can be released upon retraction of the driver <NUM>. The driver head <NUM> may be proximally withdrawn into the outer sheath <NUM> before the outer sheath <NUM> is withdrawn into the delivery catheter <NUM>.

The non-implanted components of the ventricular anchor delivery subsystem <NUM> may be removed from the delivery catheter <NUM> and subsequent subsystems may be placed in the delivery catheter <NUM> for completing implantation of the neo chordae. In a modified embodiment, the ventricular anchor delivery subsystem <NUM> and subsequent subsystems such as the leaflet anchor delivery subsystem <NUM> may be positioned within the delivery catheter <NUM> at the same time and in certain arrangements the tissue and leaflet anchors can both be preloaded into the delivery catheter. In alternative embodiments, the implantation of the ventricular anchor may be performed in a different order (e.g., after the implantation of the leaflet anchor). The ventricular anchor delivery components may be proximally retracted over a proximal end of the suture <NUM>, which may remain extending through the delivery catheter <NUM> to the ventricular anchor <NUM>.

<FIG> depict the deployment of the leaflet anchor. Referring to <FIG>, the ventricular anchor <NUM> has been deployed and is tethered to the catheter <NUM> by a ventricular anchor suture <NUM> and the ventricular anchor subsystem has been removed. The leaflet anchor is carried within a needle <NUM>, shown aimed at a target site on the atrial side of the leaflet. The needle <NUM> is axially reciprocally carried within the catheter <NUM>, such as within a tubular sleeve <NUM> advanceable through the catheter <NUM>. Additional details of the needle and needle driver are discussed below.

As shown in <FIG>, in the illustrated arrangement, the needle can cross through the leaflet from the atrium to the ventricle and a preloaded suture can then be advanced into the ventricle. The suture can then be used to collapse the pledget against the ventricular side of the leaflet to anchor the suture to the leaflet as shown in <FIG>. Thus the pledget forms a radially enlargeable leaflet anchor. In certain embodiments, other forms of a radially enlargeable leaflet anchor can be used.

The leaflet anchor and suture can then be used in combination with a ventricular anchor, suture and suture lock to effectively create a new mitral chord as shown in <FIG>. As noted above, the leaflet anchor and suture can be used in combination with the systems and methods for the transvascular prosthetic chordae tendinae implantation disclosed in the <CIT> and the various embodiments of ventricular anchors, sutures and suture locks disclosed therein.

Preferably, the leaflet anchor deployment subassembly is provided with a temporary anchor for capturing and stabilizing the leaflet while the needle tip <NUM> is advanced therethrough at a target side. As illustrated in <FIG> and <FIG>, a distal end <NUM> of delivery tube <NUM> or other system component carries a temporary tissue anchor such as a helical tissue anchor <NUM>. Anchor <NUM> may be similar to ventricular anchor <NUM> except that temporary anchor <NUM> does not have a distal barb since it is intended to be only momentarily in engagement with the leaflet. The anchor <NUM> thus comprises a helical element <NUM> which terminates in a distal tip <NUM>.

In use, the distal tip <NUM> is positioned at a target site on the surface of the leaflet, and the helical element <NUM> is rotated about its axis to engage and penetrate the leaflet. The needle tip <NUM> may be optionally engaged with the leaflet prior to rotation of the helical element <NUM>, and utilized to stabilize the anchor against moving away from the target site in response to rotation, in a manner similar to that discussed in connection with the ventricular anchor and <FIG>.

Following engagement of the helical element <NUM> to capture the leaflet from the atrial side and secure the leaflet to the catheter, the needle may be advanced distally through the central lumen defined by the helical element <NUM> and completely through the leaflet so that the needle tip <NUM> exits the ventricular side of the leaflet as seen in <FIG>. An anchor deployment actuator such as a pusher extending through the needle may be utilized to deploy the anchor from the needle and into the ventricle.

Referring to <FIG>, the leaflet anchor may be a pledget <NUM> similar to those described elsewhere herein. The pledget <NUM> may be coupled or attached to the distal end of a leaflet anchor suture <NUM>. The pledget may comprise a soft and/or flexible material such as a fabric. The suture <NUM> may extend through the needle <NUM>. The pledget <NUM> may be folded or compressed in a conformation comprising a reduced radial cross section such that it may be disposed within the needle <NUM> for delivery, as shown in <FIG> and <FIG> discussed below. The pledget <NUM> may expand from a reduced cross section to assume a larger radial cross section upon deployment from the distal end of the needle tip <NUM>, as shown in <FIG>. In some embodiments, the pledget <NUM> may be pushed through the needle <NUM> via a push wire or release wire (not shown). Upon delivery through the needle tip <NUM>, proximal retraction of the leaflet suture <NUM> as shown in <FIG> may cause the leaflet anchor to assume an axially collapsed, radially enlarged conformation which prevents the leaflet anchor from being retracted through the puncture in the leaflet and thereby anchors the leaflet suture <NUM> to the leaflet, as shown in <FIG>.

<FIG> schematically depict a pledget <NUM> connected to the distal end of a leaflet suture <NUM>. The pledget <NUM> may comprise two wings <NUM>, <NUM>, which may be rolled/folded (e.g., both in a clockwise or counterclockwise direction) around a longitudinal axis of the pledget <NUM> to form a reduced cross section conformation. In some embodiments, the leaflet suture <NUM> may be integrally formed with the pledget <NUM>. In order to produce a foldable or collapsible configuration, the suture <NUM> may extend distally through the pledget, loop around the distal end of the pledget and return proximally and threaded back through one or more apertures (e.g., two apertures, three apertures, four apertures, etc.) formed in the pledget <NUM>, as shown in <FIG>. In some embodiments, the apertures may be aligned along a center of the pledget <NUM>.

The apertures may extend through the pledget <NUM> and through the portion of the embedded portion of the suture <NUM> which is integral with the pledget <NUM>. The embedded portion of the suture <NUM> may be at least partially flatted within the pledget <NUM>. In some embodiments, the apertures may be placed substantially near the center of the pledget (e.g., immediately to the left or right of the embedded suture <NUM> or alternating between the left and right side of the suture <NUM>). When deployed the suture <NUM> may be effectively joined to a distal end of the pledget <NUM> (e.g., the suture <NUM> may loop back to where it inserts between the pledget sheets).

<FIG> schematically depict an example of a pledget as described elsewhere herein. <FIG> schematically depicts a pledget <NUM> formed by affixing a distal end (shown in dashed lines) of the suture <NUM> between two flat sheets, such that the sheets for left and right wings <NUM>, <NUM>. <FIG> shows a cross-section of the pledget <NUM> along the axis of B-B illustrated in <FIG>. In some embodiments, the suture <NUM> may be inserted between two sheets (e.g., substantially down the middle of the sheets) and pressed and/or laminated to join the three components together (e.g., under heat and/or pressure). At least one of the layers may be partially sintered. The suture <NUM> may be flattened and/or densified to improve resistance to suture tear out. The sheets may be flat polytetrafluoroethylene (PTFE) sheets (e.g., thin uncured expanded PTFE (ePTFE) sheets) or any other suitable material. In some implementations, the leaflet suture <NUM> may be disposed between the sheets in alternative configurations, such as a zig-zag or s-shaped configuration. <FIG> shows the pledget <NUM> of <FIG> comprising a plurality of apertures <NUM> through which the proximal tail end of the suture <NUM> may be threaded through.

In some embodiments, one or more apertures <NUM> may be formed through the pledget, in various configurations, to form a collapsible structure, as described elsewhere herein, which is configured to anchor the suture <NUM> against the mitral leaflet. <FIG> shows apertures <NUM> alternating around opposing sides of the suture <NUM>. In some embodiments, the apertures <NUM> may be formed on the same side of the suture <NUM> (e.g., in wing <NUM> or wing <NUM>). In some embodiments, the apertures <NUM> may be formed through the suture <NUM>. The apertures <NUM> may be aligned along a center of the pledget <NUM>. The apertures <NUM> may be aligned along the length of the suture <NUM> (e.g., may form a straight line). The suture <NUM> may be at least partially flattened between the two opposing sheets, which may facilitate the placement of apertures <NUM> through the suture <NUM>. Various combinations of apertures <NUM>, including the positioning described above, may be used.

The pledget <NUM> may be formed such that the wings <NUM>, <NUM> are approximately the same size or they may be formed to be different sizes. Upon proximal retraction of the leaflet suture <NUM>, the pledget <NUM> may be folded to assume an accordion-like conformation, as depicted in <FIG>. The pledget <NUM> may assume a conformation comprising a substantially planar proximal surface which is approximately perpendicular to the longitudinal axis of the leaflet suture <NUM>. This conformation may facilitate anchoring the suture <NUM> in the leaflet. Upon anchoring the leaflet suture <NUM> in the leaflet, the leaflet anchor delivery subsystem <NUM> may be withdrawn from the delivery catheter <NUM>. The leaflet anchor delivery components may be proximally retracted over a proximal end of the suture <NUM>, which may remain extending through the delivery catheter <NUM> to the leaflet anchor <NUM>, alongside the ventricular anchor suture <NUM>.

<FIG> illustrate various views of the leaflet anchor delivery subsystem <NUM> and its components. <FIG> depicts a perspective view of a distal end of the subsystem <NUM>. <FIG> depicts a perspective view of a proximal end of the subsystem <NUM>. <FIG> depicts an exploded view of the distal end of the subsystem <NUM>.

As shown in <FIG> and <FIG>, the leaflet anchor delivery subsystem <NUM> may comprise an outer delivery tube <NUM>. The tube <NUM> may optionally include a deflection zone and may be configured to be steerable by an operator such as by proximal retraction of one or two or more pull wires (not shown) along various sides of the flex tube <NUM>. The operator may control the flexion of the flex tube via a knob <NUM> or lever or other actuation mechanism positioned on a handle <NUM> at the proximal end of the leaflet anchor delivery subsystem <NUM>, as shown in <FIG>.

An internal tubular shaft or needle <NUM> terminating at a distal end with a needle point <NUM> may extend through the delivery tube <NUM>. The internal needle <NUM> may comprise a hypotube, extrusion or braided tube or catheter which is flexible enough to conform to the shape of the optional flex tube <NUM>. A needle tip <NUM> may be coupled to the distal end of the internal flexible shaft <NUM>. A flexible jacket <NUM> may surround the flex tube <NUM> and a delivery shaft <NUM>.

The proximal end of the internal tubular shaft <NUM> may be connected to a needle handle <NUM>, as shown in <FIG>. The needle handle <NUM> may comprise a hemostasis valve <NUM>. The leaflet suture <NUM> may be inserted through valve <NUM>. Valve <NUM> may be a tuohy-borst valve. The needle handle <NUM> may include additional ports <NUM> for accessing the lumen of the internal flexible shaft <NUM>. The needle handle <NUM> may be positioned proximally to the handle <NUM> such that the internal flexible shaft <NUM> extends through the handle <NUM> and into the lumen of the delivery shaft <NUM>. The handle <NUM> may comprise a hemostasis valve for receiving the internal flexible shaft <NUM> and sealing the internal components of the handle, including the opening to the delivery shaft <NUM>, from the ambient environment.

The needle tip <NUM> may be extendable and retractable by extending the needle handle <NUM> toward the handle <NUM> or retracting the needle handle <NUM> from the handle <NUM>, respectively. Distal advance of the needle <NUM> may be accomplished by manually advancing the handle <NUM>. Alternatively, the distal advance of the needle may be assisted by a mechanical or electromechanical mechanism to produce a relatively high velocity, low stroke length distal advance.

Exertion of pressure on the leaflet when the needle tip <NUM> is extended distally beyond the tube <NUM> may cause the needle tip <NUM> to puncture the leaflet such that the needle tip <NUM> may extend through to the opposite side (e.g., the atrial side) of the leaflet, as shown in <FIG>. This pressure may be exerted by extending the needle tip <NUM> and/or retracting the entire delivery device <NUM> in a proximal direction with the needle tip <NUM> in an extended position.

The ventricular anchor suture <NUM> and the leaflet anchor suture <NUM> may be coupled together in a tensioned fashion to form the neo chordae implant or to join two sections of the neo chordae implant together, such that the neo chordae extends between the ventricular anchor <NUM> and the leaflet anchor <NUM> across the atrial side of the coaptive edge of the leaflet. The overall length of the neo chordae may be adjusted by proximal traction of one or both sutures <NUM>, <NUM> prior to engaging the suture lock <NUM> such that an appropriate tension is applied to the leaflet, with the tension subsequently maintained by the ventricular anchor <NUM>. The sutures <NUM>, <NUM> may remain extending proximally through the delivery catheter <NUM> to a location outside the body. In some embodiments, the proximal ends of the suture <NUM>, <NUM> may be fed into a handle or proximal portion of a suture lock delivery system <NUM> to facilitate placement of the suture lock and cutting of the sutures <NUM>, <NUM>. In some embodiments, the proximal ends may remain free or coupled or secured by other means.

<FIG> depicts the advancement of suture lock <NUM> over the ventricular anchor suture <NUM> and the leaflet suture <NUM>. The suture lock delivery subsystem <NUM> may be advanced through the delivery catheter <NUM> and a tubular pusher catheter <NUM> may push a suture lock <NUM> along the distal direction of the sutures <NUM>, <NUM>. Once the suture lock <NUM> has reached the ventricle, it can continue to be pushed along the ventricle suture <NUM> with proximal traction on the suture <NUM> and while allowing the leaflet suture <NUM> to feed distally through the catheter if needed for the suture lock <NUM> to advance distally to the ventricular anchor. As discussed further below, <FIG> illustrates the final construct with the leaflet anchor and ventricular anchors tethered together to form an artificial chordae. The proximal tails of the two sutures has been severed and catheter proximally retracted from the ventricle through the mitral valve.

<FIG> illustrate various views of the suture lock delivery subsystem <NUM> and its components. <FIG> depicts a perspective view of a distal end of the subsystem <NUM>. <FIG> depicts a perspective view of a proximal end of the subsystem <NUM>. <FIG> depicts a partially exploded view of the distal end of the subsystem <NUM>. <FIG> depicts a perspective view of a distal end of a cutting assembly. <FIG> depict side views of a cutting assembly portion of the subsystem <NUM>. <FIG> depicts a side view of a suture lock <NUM> and a distal end of a torque driver <NUM> configured to engage the suture lock <NUM>. <FIG> depict a proximal end view and a distal end view, respectively, of the suture lock <NUM>.

The suture lock delivery subsystem <NUM> may be configured to advance (e.g., slide) a suture lock <NUM> over both the sutures <NUM>, <NUM> (or even three or four or additional sutures) securing them together. The sutures <NUM>, <NUM> may each be proximally retracted relative to the suture lock <NUM> to tension the sutures <NUM>, <NUM> and modulate the length of each suture <NUM>, <NUM> between the suture lock <NUM> and the respective tissue anchors <NUM>, <NUM>. Once the tension and length of the neo chordae implant is optimized, the suture lock <NUM> may be locked to fix the length of the sutures <NUM>, <NUM> such that the sutures <NUM>, <NUM> can no longer move with respect to the suture lock <NUM>. The sutures <NUM>, <NUM> may then be severed at a point proximal to the suture lock <NUM>. The suture <NUM>, <NUM> may be cut by the same suture lock delivery subsystem <NUM> which delivered the suture lock <NUM>. In other embodiments, a separate cutting device may be inserted into the delivery catheter <NUM> after the suture lock has been locked in place.

The suture lock allows one or two or more sutures to be advanced therethrough and adjusted, and then locked with sufficient clamping efficiency that an ePTFE suture can be prevented from slipping from the suture lock under normal use conditions (e.g., withstand tension of at least about <NUM>% or <NUM>% or more of the suture breaking strength, without slipping). The lock may be reopened to permit readjustment of the tension on the mitral leaflet, and retightened, until a desired result has been achieved. The tightening tool may then be removed, leaving the suture lock behind.

The suture lock <NUM> may be advanced along the sutures by a retainer catheter <NUM>. The distal end of the retainer catheter <NUM> may be coupled to a retainer element <NUM> (<FIG>). The retainer element may comprise a flange <NUM> or other mechanical feature configured to engage the suture lock <NUM>. For example, the flange <NUM> may be inserted into a recess at a proximal end of the suture lock <NUM>. In some embodiments, rotation of the retainer catheter <NUM> and/or translation substantially perpendicular to the axial direction of the retainer catheter <NUM> may be used to disengage the retainer catheter <NUM> from the suture lock <NUM>.

The sutures <NUM>, <NUM> may extend from their respective tissue anchors to pass through the suture lock <NUM>, entering from a distal opening <NUM> in a distal face of the suture lock <NUM>, shown in <FIG>, and exiting at a proximal opening <NUM> to the suture path in a proximal face of the suture lock <NUM>, shown in <FIG>. The sutures <NUM>, <NUM> may extend through a channel in a cutter head <NUM> proximal to the suture lock <NUM> and along the outside of the retainer catheter <NUM> and through the delivery catheter <NUM>. The cutter head <NUM> may be coupled to the distal end of a cutter catheter <NUM>. The retainer catheter <NUM> may extend through an internal lumen of the cutter catheter <NUM> such that the two catheters <NUM>, <NUM> may be extendable or retractable relative to one another.

Once the sutures <NUM>, <NUM> are locked (fixedly secured) within the suture lock <NUM>, the proximal ends of the suture <NUM>, <NUM> may be cut adjacent to the proximal face of the suture lock. The sutures <NUM>, <NUM> may be cut by advancing the cutter catheter <NUM> coupled to the cutter head <NUM> toward the proximal face of the suture lock <NUM>. As schematically illustrated in <FIG>, as the cutter head <NUM> advances along the retainer catheter <NUM> toward the retainer element <NUM>, the cutter head brings the sutures <NUM>, <NUM> into close proximity to a cutting blade <NUM> positioned on the retainer element <NUM>. The cutter head <NUM> is configured to advance over the retainer element <NUM> in such a fashion that the channel in the cutter head <NUM> retaining the sutures <NUM>, <NUM> becomes increasingly spatially occupied by the blade <NUM>. As the blade <NUM> is forced into the channel of the cutter head <NUM>, the blade <NUM> shears the sutures <NUM>, <NUM>. Application of proximal tension to the sutures <NUM>, <NUM> may facilitate the cutting of the sutures <NUM>, <NUM>. In other embodiments, different actuations (e.g., rotation of a cutting catheter) can be configured to sever the sutures <NUM>, <NUM>.

In some implementations, more than two sutures may be employed and may be locked within the suture lock <NUM> and severed by the suture lock delivery subsystem <NUM> in the same fashion. In some embodiments, advancement of the cutter head <NUM> over the retainer element <NUM> may facilitate the disengagement of the retainer catheter <NUM> from the suture lock <NUM>. For example, the cutter head <NUM> may advance to a distal position where it is configured to stabilize the suture lock <NUM>, allowing the retainer catheter <NUM> to be axially and/or rotationally disengaged from the suture lock <NUM>.

<FIG> illustrates a side view of an example of a suture lock <NUM> (shown with its outer casing/shell removed). The sutures may pass through the suture lock <NUM> from a distal end to a proximal end as described elsewhere herein. The suture lock <NUM> may comprise a screw <NUM> configured to distally advance or proximally retract a push wedge <NUM>, depending on the direction of rotation of the screw. The screw <NUM> may be rotated by a torque shaft <NUM>. The torque shaft <NUM> may comprise a driver head configured to mate with recess <NUM> (e.g., a polygonal recess or other non-circular shaped recess, as shown in <FIG>) positioned at the proximal end of the suture lock <NUM> such that rotation of the torque shaft <NUM> causes rotation of the screw <NUM>. The torque shaft <NUM> may extend through an internal lumen of the retainer catheter <NUM>. The torque shaft <NUM> may be rotated at its proximal end by a knob <NUM> or other actuation mechanism positioned at a proximal end of the subsystem handle <NUM>. The handle <NUM> may include a hemostasis valve <NUM>. In some implementations, the sutures <NUM>, <NUM> may pass through the hemostasis valve <NUM>.

Advancement of the push wedge <NUM> by the torque shaft <NUM> may cause a ramp or angled surface <NUM> to gradually compress one or more springs, such as spring pins <NUM>. The springs bias the clamp upward to open the suture path until forced closure by rotation of the torque shaft <NUM>. Compression of the one or more springs <NUM> may force a clamp <NUM> downward on the sutures <NUM>, <NUM>, compressing the sutures <NUM>, <NUM> between two opposing surfaces. In some embodiments, the clamp <NUM> and the opposing surface <NUM> may have notched surfaces configured to mate with each other at discrete increments. The mated notched surfaces may provide enhanced friction and in some implementations mechanical interference for retention of the sutures <NUM>, <NUM> between the opposing surfaces such that they cannot be withdrawn, either proximally or distally, from the suture lock <NUM>. In some embodiments, the tightening may be reversible by rotating the torque shaft in an opposite direction.

Once the suture lock is properly positioned over the sutures <NUM>, <NUM> and locked into place, the sutures <NUM>, <NUM> may be severed as described elsewhere herein. <FIG> depicts the retraction of the suture lock delivery subsystem <NUM> after the sutures <NUM>, <NUM> have been cut. Once the suture lock delivery subsystem <NUM> has been removed from the delivery catheter <NUM>, the delivery catheter <NUM> may be withdrawn from the body.

Although this disclosure describes certain embodiments and examples, many aspects of the above-described systems and methods may be combined differently and/or modified to form still 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.

Furthermore, certain features that are described in this disclosure in the context of separate implementations can also be implemented in combination in a single implementation. Moreover, although features may be described above as acting in certain combinations, one or more features from a claimed combination can, in some cases, be excised from the combination, and the combination may be claimed as a subcombination or variation of a sub combination.

The disclosure herein of any particular feature, aspect, method, property, characteristic, quality, attribute, element, or the like in connection with various embodiments can be used in all other embodiments set forth herein. Also, any methods described herein may be practiced using any device suitable for performing the recited steps.

Moreover, while components and operations may be depicted in the drawings 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 in sequential order, nor include all of the components and operations, to achieve desirable results. Other components and operations that are not depicted or described can be incorporated in the embodiments and examples.

Claim 1:
A neo chordae tendinae deployment system, comprising:
a catheter (<NUM>) having a proximal end and a distal end;
a helical ventricular anchor subassembly (<NUM>) extendable through the catheter, the ventricular anchor subassembly comprising:
a hub (<NUM>), a ventricular suture (<NUM>) extending proximally from the hub;
a helical anchor (<NUM>) extending distally from the hub;
a core wire (<NUM>) extending concentrically through the helical anchor, and beyond the distal end of the helical anchor, and
a flexible, tubular sleeve (<NUM>) extending proximally from the hub, wherein the flexible, tubular sleeve extending proximally from the hub has a length of no more than about <NUM>; and J
a leaflet anchor deployment subassembly extendable through the catheter, having a radially enlargeable leaflet anchor (<NUM>) within the subassembly and having a leaflet suture Z (<NUM>) extending proximally through the catheter.