Patent ID: 12220315

DETAILED DESCRIPTION

As described herein, when one or more components are described as being connected, joined, affixed, coupled, attached, or otherwise interconnected, such interconnection may be direct as between the components or may be indirect such as through the use of one or more intermediary components. Also as described herein, reference to a “member,” “component,” or “portion” shall not be limited to a single structural member, component, or element but can include an assembly of components, members, or elements. Also as described herein, the terms “substantially” and “about” are defined as at least close to (and includes) a given value or state (preferably within 10% of, more preferably within 1% of, and most preferably within 0.1% of).

A prosthetic device has a coaptation means or coaption element and at least one anchoring means or anchor. The coaption element is configured to be positioned within the native heart valve orifice to help form a more effective seal between the native leaflets, thereby reducing or preventing regurgitation. The coaption element can have a structure that is impervious to blood and that allows the native leaflets to close together on each side of the coaption element during ventricular systole to block blood from flowing from the left or right ventricle back into the left or right atrium, respectively. The prosthetic device can be configured to seal against two or three native valve leaflets; that is, the device may be used in the native mitral (bicuspid) and tricuspid valves. The coaption element is sometimes referred to herein as a spacer because the coaption element can fill a space between improperly functioning native mitral or tricuspid leaflets that do not close completely.

The coaption element can have various shapes. In some embodiments, the coaption element can have an elongated cylindrical shape having a round cross-sectional shape. In other embodiments, the coaption element can have an oval cross-sectional shape, a crescent cross-sectional shape, or various other non-cylindrical shapes. The coaption element can have an atrial or upper end positioned in or adjacent to the left atrium, a ventricular or lower end positioned in or adjacent to the left ventricle, and a side surface that extends between the native mitral leaflets. In embodiments configured for use in the tricuspid valve, the atrial or upper end is positioned in or adjacent to the right atrium, and the ventricular or lower end is positioned in or adjacent to the right ventricle, and the side surface that extends between the native tricuspid leaflets.

The anchor can be configured to secure the device to one or both of the native mitral leaflets such that the coaption element is positioned between the two native leaflets. In embodiments configured for use in the tricuspid valve, the anchor is configured to secure the device to one, two, or three of the tricuspid leaflets such that the coaption element is positioned between the three native leaflets. In some embodiments, the anchor can attach to the coaption element at a location adjacent the ventricular end of the coaption element. In some embodiments, the anchor can attach to an actuation means such as a shaft or actuation wire, to which the coaption element is also attached. In some embodiments, the anchor and the coaption element can be positioned independently with respect to each other by separately moving each of the anchor and the coaption element along the longitudinal axis of the shaft or actuation wire. In some embodiments, the anchor and the coaption element can be positioned simultaneously by moving the anchor and the coaption element together along the longitudinal axis of the shaft or actuation wire. The anchor can be configured to be positioned behind a native leaflet when implanted such that the leaflet is captured by the anchor.

The prosthetic device can be configured to be implanted via a delivery means such as a delivery sheath. The coaption element and the anchor can be compressible to a radially compressed state and can be self-expandable to a radially expanded state when compressive pressure is released. The device can be configured for the anchor to be expanded radially away from the still-compressed coaption element initially in order to create a gap between the coaption element and the anchor. A native leaflet can then be positioned in the gap. The coaption element can be expanded radially, closing the gap between the coaption element and the anchor and capturing the leaflet between the coaption element and the anchor. In some embodiments, the anchor and coaption element are optionally configured to self-expand. The implantation methods for various embodiments can be different, and are more fully discussed below with respect to each embodiment. Additional information regarding these and other delivery methods can be found in U.S. Pat. No. 8,449,599 and U.S. Patent Application Publication Nos. 2014/0222136, and 2014/0067052, 2016/0331523 each of which is incorporated herein by reference in its entirety.

The disclosed prosthetic devices are prevented from atrial embolization by having the anchor hooked to a leaflet, taking advantage of the tension from native chordae tendineae to resist high systolic pressure urging the device toward the left atrium. During diastole, the devices can rely on the compressive and retention forces exerted on the leaflet that is captured by the anchor to resist embolization into the left ventricle.

Referring now toFIGS.1-6, an implantable prosthetic device100is shown in various stages of deployment. The device100is deployed from a delivery sheath102and includes a coaption portion104and an anchor portion106. The coaption portion104of the device100includes a coaption element110that is adapted to be implanted between the leaflets of the native mitral valve and is slideably attached to an actuation wire or shaft112. The anchor portion106is actuatable between open and closed conditions and can take a wide variety of forms, such as, for example, paddles, gripping elements, or the like. Actuation of the actuation wire112opens and closes the anchor portion106of the device100to capture the mitral valve leaflets during implantation. The actuation wire or shaft112may take a wide variety of different forms. For example, the actuation wire or shaft may be threaded such that rotation of the actuation wire or shaft moves the anchor portion106relative to the coaption portion104. Or, the actuation wire or shaft may be unthreaded, such that pushing or pulling the actuation wire or shaft112moves the anchor portion106relative to the coaption portion104.

The anchor portion106of the device100includes outer paddles or gripping elements120and inner paddles or gripping elements122that are connected between a cap114and the coaption element110by portions124,126,128. The portions124,126,128may be hinged and/or flexible to move between all of the positions described below. The actuation wire112extends through the delivery sheath and the coaption element110to the cap114at the distal end of the anchor portion106. Extending and retracting the actuation wire112increases and decreases the spacing between the coaption element110and the cap114, respectively. An attaching means or collar (not shown) removably attaches the coaption element110to the delivery sheath102so that the coaption element110slides along the actuation wire112during actuation to open and close the paddles120,122of the anchor portion106.

Referring toFIG.3, the barbed clasps130include a base or fixed arm132, a moveable arm134, barbs136, and a hinge portion138. The fixed arms132are attached to the inner paddles122, with the hinge portion138disposed proximate the coaption element110. The hinge portion138provides a spring force between the fixed and moveable arms132,134of the barbed clasp130. The hinge portion138can be any suitable hinge, such as a flexible hinge, a spring hinge, a pivot hinge, or the like. In certain embodiments, the hinge portion138is a flexible piece of material integrally formed with the fixed and moveable arms132,134. The fixed arms132are attached to the inner paddles122and remain stationary relative to the inner paddles122when the moveable arms134are opened to open the barbed clasps130and expose the barbs136. The barbed clasps130are opened by applying tension to actuation lines116attached to the ends of the moveable arms134, thereby causing the moveable arms134to pivot on the hinge portions138.

During implantation, the paddles120,122are opened and closed to capture the native mitral valve leaflets between the paddles120,122and the coaption element110. The barbed clasps130further secure the native leaflets by engaging the leaflets with barbs136and pinching the leaflets between the moveable and fixed arms134,132. The barbs136of the barbed clasps130increase friction with the leaflets or may partially or completely puncture the leaflets. The actuation lines116can be actuated independently so that each barbed clasp130can be opened and closed independently. Independent operation allows one leaflet to be captured at a time, or for the repositioning of a clasp130on a leaflet that was insufficiently captured, without altering a successful grasp on the other leaflet. The barbed clasps130not only open and close independent from each other but can fully be opened and closed independent from the position of the inner paddle122, thereby allowing leaflets to be captured in a variety of positions as the particular situation requires.

The barbed clasps130can be opened independently by pulling on an attached actuating means or actuation line116that extends through the delivery sheath102to the end of the barbed clasp130. The actuation line116can take a wide variety of forms, such as, for example, a line, a suture, a wire, a rod, a catheter, or the like. The barbed clasps130can be spring loaded so that in the closed position the barbed clasps130continue to provide a pinching force on the captured native leaflet. This pinching force remains constant regardless of the position of the inner paddles122. Barbs136of the barbed clasps130can pierce the native leaflets to further secure the native leaflets.

Referring now toFIG.1, the device100is shown in an elongated or fully open condition for deployment from the delivery sheath. The device100is loaded in the delivery sheath in the fully open position, because the fully open position takes up the least space and allows the smallest catheter to be used (or the largest device100to be used for a given catheter size). In the elongated condition the cap114is spaced apart from the coaption element110such that the paddles120,122of the anchor portion106are inverted or fully open. In some embodiments, an angle formed between the interior of the outer and inner paddles120,122is approximately 180 degrees. The barbed clasps130are kept in a closed condition during deployment through the delivery sheath102so that the barbs136(FIG.3) do not catch or damage the sheath or tissue in the patient's heart.

Referring now toFIG.1A, the device100is shown in an elongated detangling condition, similar toFIG.1, but with the barbed clasps130in a fully open position, ranging from about 140 degrees to about 200 degrees, to about 170 degrees to about 190 degrees, or about 180 degrees between fixed and moveable portions of the barbed clasps130. Fully opening the device100and the clasps130has been found to improve ease of detanglement from anatomy of the patient during implantation of the device100.

Referring now toFIG.2, the device100is shown in a shortened or fully closed condition. The compact size of the device100in the shortened condition allows for easier maneuvering and placement within the heart. To move the device100from the elongated condition to the shortened condition, the actuation wire112is retracted to pull the cap114towards the coaption element110. The hinges or flexible connections126between the outer paddle120and inner paddle122are limited in movement such that compression forces acting on the outer paddle120from the cap114being retracted towards the coaption element110cause the paddles or gripping elements120,122to move radially outward. During movement from the open to closed position, the outer paddles120maintain an acute angle with the actuation wire112. The outer paddles120can optionally be biased toward a closed position. The inner paddles122during the same motion move through a considerably larger angle as they are oriented away from the coaption element110in the open condition and collapse along the sides of the coaption element110in the closed condition. In certain embodiments, the inner paddles122are thinner and/or narrower than the outer paddles120, and the hinge or flexible portions126,128connected to the inner paddles122are thinner and/or more flexible to allow more movement than the hinge or flexible portion124connecting the outer paddle124to the cap114.

Referring now toFIGS.3-5, the device100is shown in a partially open, capture-ready condition. To transition from the fully closed to the partially open condition, the actuation wire112is extended to push the cap114away from the coaption element110, thereby pulling on the outer paddles120, which in turn pulls on the inner paddles122, causing the anchor portion106to partially unfold. The actuation lines116are also retracted to open the clasps130so that the leaflets can be captured.

Referring now toFIG.4, one of the actuation lines116is extended to allow one of the clasps130to close. Referring now toFIG.5, the other actuation line116is extended to allow the other clasp130to close. Either or both of the actuation lines116may be repeatedly actuated to repeatedly open and close the barbed clasps130.

Referring now toFIG.6, the device100is shown in a fully closed and deployed condition. The delivery sheath102and actuation wire112are retracted and the paddles120,122and clasps130remain in a fully closed position. Once deployed, the device100may be maintained in the fully closed position with a mechanical latch or may be biased to remain closed through the use of spring materials, such as steel, other metals, plastics, composites, etc. or shape-memory alloys such as Nitinol. For example, the hinged or flexible portions124,126,128,138, and/or the inner and outer paddles122, and/or an additional biasing component (see component224inFIG.13) may be formed of metals such as steel or shape-memory alloy, such as Nitinol—produced in a wire, sheet, tubing, or laser sintered powder—and are biased to hold the outer paddles120closed around the coaption element110and the barbed clasps130pinched around native leaflets. Similarly, the fixed and moveable arms132,134of the barbed clasps130are biased to pinch the leaflets. In certain embodiments, the hinge portions124,126,128,138, and/or the inner and outer paddles122, and/or an additional biasing component (see component224inFIG.13) may be formed of any other suitably elastic material, such as a metal or polymer material, to maintain the device in the closed condition after implantation.

Referring now toFIGS.7-12, the implantable device100ofFIGS.1-6is shown being delivered and implanted within a native mitral valve40of a heart10. Referring now toFIG.7, the delivery sheath is inserted into the left atrium20through the septum and the device100is deployed from the delivery sheath in the fully open condition. The actuation wire112is then retracted to move the device100into the fully closed condition shown inFIG.8. As can be seen inFIG.9, the device100is moved into position within the mitral valve40into the ventricle30and partially opened so that the leaflets42,44can be captured. Referring now toFIG.10, an actuation line116is extended to close one of the clasps130, capturing a leaflet42.FIG.11shows the other actuation line116being then extended to close the other clasp130, capturing the remaining leaflet44. Lastly, as can be seen inFIG.12, the delivery sheath102and actuation wire112are then retracted and the device100is fully closed and deployed in the native mitral valve400.

Referring now toFIG.13, an implantable prosthetic device200is shown. The implantable device200is one of the many different configurations that the device100that is schematically illustrated inFIGS.1-12can take. The device200is deployed from a delivery sheath (not shown) and includes a coaption portion204and an anchor portion206. The device200is loaded in the delivery sheath in the fully open position, because the fully open position takes up the least space and allows the smallest catheter to be used (or the largest device200to be used for a given catheter size). The coaption portion204of the device includes a coaption element210for implantation between the leaflets of the native mitral valve that is slideably attached to an actuation wire or shaft212. Actuation of the actuation wire212opens and closes the anchor portion206of the device200to capture the mitral valve leaflets during implantation.

The anchor portion206of the device200includes outer paddles220and inner paddles222that are hingeably connected to the cap214and the coaption element210. The actuation wire212extends through the delivery sheath (not shown), a collar211, and the coaption element210to the cap214at the distal end of the anchor portion206. Extending and retracting the actuation wire212increases and decreases the spacing between the coaption element210and the cap214, respectively. The collar211optionally includes a collar seal213that forms a seal around the actuation wire or shaft212during implantation of the device200, and that seals shut when the actuation wire212is removed to substantially close the device200to blood flow through the interior of the coaption element210after implantation. In some embodiments, the collar2011removably engages and attaches the coaption element200to the delivery sheath so that the coaption element210slides along the actuation wire212during actuation to open and close the paddles220,222of the anchor portion206. In some embodiments, the collar2011is held closed around the coaption element2010by the actuation wire212, such that removal of the actuation wire212allows fingers (not shown) of the collar to open, releasing the coaption element210. In some embodiments, the cap2014optionally includes a seal216and/or an insert218that fit inside an opening215of the coaption element210, the coaption element210having a hollow interior. The seal216and/or insert218maintain the coaption element210substantially closed to blood flow when the actuation wire212is withdrawn and the device200is implanted.

The coaption element210and paddles220,222are formed from a covering that may be a mesh, woven, braided, or formed in any other suitable way. The covering may be cloth, shape-memory alloy wire—such as Nitinol—to provide shape setting capability, or any other flexible material suitable for implantation in the human body. Paddle frames224provide additional pinching force between the outer paddles222and the coaption element210, and assist in wrapping the leaflets around the sides of the coaption element210for a better seal between the coaption element210and the leaflets. In some embodiments, the covering extends around the paddle frames224.

The barbed clasps230include a base or fixed arm232, a moveable arm234, barbs236, and a hinge portion238. The fixed arms232are attached to the inner paddles222, with the hinge portion238disposed proximate the coaption element210. The fixed arms232are attached to the inner paddles222through holes or slots233with sutures (not shown). The fixed arms232may be attached to the inner paddles222with any suitable means, such as screws or other fasteners, crimped sleeves, mechanical latches or snaps, welding, adhesive, or the like. The fixed arms232remain stationary relative to the inner paddles222when the moveable arms234are opened to open the barbed clasps230and expose the barbs236. The barbed clasps230are opened by applying tension to actuation lines (not shown) attached to holes235disposed at ends of the moveable arms234, thereby causing the moveable arms234to pivot on the hinge portions238.

During implantation, the paddles220,222are opened and closed to capture the native mitral valve leaflets between the paddles220,222and the coaption element210. The barbed clasps230further secure the native leaflets by engaging the leaflets with barbs236and pinching the leaflets between the moveable and fixed arms234,232. The barbs236of the barbed clasps230increase friction with the leaflets or may partially or completely puncture the leaflets. The actuation lines can be actuated independently so that each barbed clasp230can be opened and closed independently. Independent operation allows one leaflet to be captured at a time, or for the repositioning of a clasp230on a leaflet that was insufficiently captured, without altering a successful grasp on the other leaflet. The barbed clasps230not only open and close independent from each other but can be fully opened and closed independent from the position of the inner paddle222, thereby allowing leaflets to be captured in a variety of positions as the particular situation requires.

Referring now toFIGS.14-25, an implantable device300is shown being delivered and implanted within the native mitral valve40of the heart10. The device300is similar to implantable device200ofFIG.13, though device300has a covering over the coaption element310, clasps330, inner paddles322and/or the outer paddles320. The device300is deployed from a delivery sheath302and includes a coaption portion304and an anchor portion306. The coaption portion304of the device includes a coaption element310for implantation between the leaflets of the native mitral valve that is slideably attached to an actuation wire or shaft312. Actuation of the actuation wire or shaft312opens and closes the anchor portion306of the device300to capture the mitral valve leaflets during implantation.

The anchor portion306of the device300includes outer paddles320and inner paddles322that are flexibly connected to the cap314and the coaption element310. The actuation wire312extends through a collar303(seeFIG.20), delivery sheath302, and the coaption element310to the cap314at the distal end of the anchor portion306. Extending and retracting the actuation wire312increases and decreases the spacing between the coaption element310and the cap314, respectively. Fingers of the collar303removably attach the coaption element310to the delivery sheath302so that the coaption element310slides along the actuation wire312during actuation to open and close the paddles320,322of the anchor portion306. In some embodiments, the collar303is held closed around the coaption element310by the actuation wire312, such that removal of the actuation wire312allows the fingers of the collar303to open, releasing the coaption element310.

The coaption element310and paddles320,322are formed from a flexible material that may be a mesh, woven, braided, or formed in any other suitable way. The flexible material may be cloth, shape-memory alloy wire—such as Nitinol—to provide shape setting capability, or any other flexible material suitable for implantation in the human body.

The barbed clasps330include a base or fixed arm332, a moveable arm334, barbs336(seeFIG.20), and a hinge portion338. The fixed arms332are attached to the inner paddles322, with the hinge portion338disposed proximate the coaption element310. Sutures (not shown) attach the fixed arms332to the inner paddles322. The fixed arms332may be attached to the inner paddles322with any suitable means, such as screws or other fasteners, crimped sleeves, mechanical latches or snaps, welding, adhesive, or the like. The fixed arms332remain stationary when the moveable arms334are opened to open the barbed clasps330and expose the barbs336. The barbed clasps330are opened by applying tension to actuation lines316attached to the ends of the moveable arms334, thereby causing the moveable arms334to pivot on the hinge portions338.

During implantation, the paddles320,322are opened and closed to capture the native mitral valve leaflets between the paddles320,322and the coaption element310. The outer paddles320have a wide curved shape that fits around the curved shape of the coaption element310to more securely grip the leaflets. The curved shape and rounded edges of the outer paddle320also prohibits tearing of the leaflet tissue. The barbed clasps330further secure the native leaflets by engaging the leaflets with barbs336and pinching the leaflets between the moveable and fixed arms334,332. The barbs336of the barbed clasps330increase friction with the leaflets or may partially or completely puncture the leaflets. The actuation lines can be actuated independently so that each barbed clasp330can be opened and closed independently. Independent operation allows one leaflet to be captured at a time, or for the repositioning of a clasp330on a leaflet that was insufficiently captured, without altering a successful grasp on the other leaflet. The barbed clasps330not only open and close independent from each other but can be fully opened and closed independent from the position of the inner paddle322, thereby allowing leaflets to be captured in a variety of positions as the particular situation requires.

The device300is loaded in the delivery sheath in the fully open position, because the fully open position takes up the least space and allows the smallest catheter to be used (or the largest device300to be used for a given catheter size). Referring now toFIG.14, the delivery sheath is inserted into the left atrium20through the septum and the device300is deployed from the delivery sheath302in the fully open condition. The actuation wire312is then retracted to move the device300into the fully closed condition shown inFIGS.15-16and then maneuvered towards the mitral valve40as shown inFIG.17. Referring now toFIG.18, when the device300is aligned with the mitral valve40, the actuation wire312is extended to open the paddles320,322into the partially opened position and the actuation lines316are retracted to open the barbed clasps330to prepare for leaflet capture. Next, as shown inFIGS.19-20, the partially open device300is inserted through the mitral valve40until leaflets are properly positioned in between the inner paddles322and the coaption element310and inside the open barbed clasps330.FIG.21shows the device300with both clasps330closed, though the barbs336of one clasp330missed one of the leaflets44. As can be seen inFIGS.22-23, the out of position clasp330is opened and closed again to properly capture the missed leaflet44. When both leaflets42,44are captured properly, the actuation wire312is retracted to move the device300into the fully closed position shown inFIG.24. With the device300fully implanted in the native mitral valve40, the actuation wire312is withdrawn to release the collar303from an upper end or plate311of the coaption element310. Once deployed, the device300may be maintained in the fully closed position with a mechanical means such as a latch or may be biased to remain closed through the use of spring material, such as steel, and/or shape-memory alloys such as Nitinol. For example, the paddles320,322may be formed of steel or Nitinol shape-memory alloy—produced in a wire, sheet, tubing, or laser sintered powder—and are biased to hold the outer paddles320closed around the coaption element310and the barbed clasps330pinched around native leaflets.

Referring now toFIG.23A, a close-up view of one of the leaflets42,44captured by one of the clasps330is shown. The leaflet42,44is captured between the moveable and fixed arms334,332of the clasp330. As shown inFIG.23A, the tissue of the leaflet42,44is not pierced by the barbs336, though in some embodiments the barbs336may partially or fully pierce through the leaflet42,44. The angle and height of the barbs336relative to the moveable arm334helps to secure the leaflet42,44within the clasp330. In particular, a force pulling the implant off of the native leaflet will encourage the barbs336to further engage the tissue, thereby ensuring better retention. Retention of the leaflet42,44in the clasp330is further improved by the position of fixed arm332near the barbs336when the clasp330is closed. In this arrangement, the tissue is formed by the fixed and moveable arms332,334and the barbs336into an S-shaped torturous path. Thus, forces pulling the leaflet away from the clasp330will encourage the tissue to further engage the barbs336before the leaflets can escape

Referring now toFIG.26, an exemplary barbed clasp400for use in implantable prosthetic devices, such as devices100,200,300described above, is shown. The barbed clasp400is formed from a top layer402and a bottom layer404. The two-layer design of the clasp400allow thinner sheets of material to be used, thereby improving the flexibility of the clasp400over a clasp formed from a single thicker sheet, while maintaining the strength of the clasp400needed to successfully retain a native valve leaflet.

The barbed clasp400includes a fixed arm410, a hinged portion420, and a movable arm430having a barbed portion440. The top and bottom layers402,404have a similar shape and in certain embodiments are attached to each other at the barbed end440. The hinged portion420is spring-loaded so that the fixed and moveable arms410,430are biased toward each other when the barbed clasp400is in a closed condition. When assembled to an implantable prosthetic device, the fixed arm410is attached to a portion of the prosthetic device. The clasp400is opened by pulling on an actuation line attached to the moveable arm430until the spring force of the hinge portion420is overcome.

The fixed arm410is formed from a tongue411of material extending from the hinged portion420between two side beams431of the moveable arm430. The tongue411is biased between the side beams431by the hinge portion420such that force must be applied to move the tongue411from a neutral position located beyond the side beams431to a p reloaded position substantially parallel with the side beams431. The tongue411is held in the preloaded position by a T-shaped cross-bar414that is attached to the tongue411and extends outward to engage the side beams431. In certain embodiments, the angle between the fixed and moveable arms410,430when the tongue is in the neutral position is about 30 to about 100 degrees, 30 to about 90 degrees, or about 30 to about 60 degrees, or about 40 to about 50 degrees, or about 45 degrees.

The tongue411includes holes412for receiving sutures (not shown) that attach the fixed arm410to an implantable device. The fixed arm410may be attached to an implantable device by various attaching means, such as screws or other fasteners, crimped sleeves, mechanical latches or snaps, welding, adhesive, or the like. In certain embodiments, the holes412are elongated slots or oval-shaped holes to accommodate sliding of the layers402,404without damaging the sutures attaching the clasp400to an implantable device.

The hinge portion420is formed by two beam loops422that extend from the tongue411of the fixed arm410to the side beams431of the moveable arm430. In certain embodiments, the beam loops422are narrower than the tongue411and side beam431to provide additional flexibility. The beam loops422each include a center portion424extending from the tongue411and an outer portion426extending to the side beams431. The beam loops422are bent into a somewhat spiral or helical shape by bending the center and outer portions424,426in opposite directions, thereby forming an offset or step distance428between the tongue411and side beams431. The step distance428provides space between the arms410,430to accommodate the native leaflet of the mitral valve after it is captured. In certain embodiments, the step distance428is about 0.5 millimeter to about 1 millimeters, or about 0.75 millimeters.

When viewed in a top plan view, the beam loops have an “omega-like” shape. This shape of the beam loops422allows the fixed and moveable arms410,430to move considerably relative to each other without plastically deforming the clasp material. For example, in certain embodiments, the tongue411can be pivoted from a neutral position that is approximately 45 degrees beyond the moveable arm430to a fully open position that ranges from about 140 degrees to about 200 degrees, to about 170 degrees to about 190 degrees, or about 180 degrees from the moveable arm430without plastically deforming the clasp material. In certain embodiments, the clasp material plastically deforms during opening without reducing or without substantially reducing the pinch force exerted between the fixed and moveable arms in the closed position.

Preloading the tongue411enables the clasp400to maintain a pinching or clipping force on the native leaflet when closed while also being able to be opened wide to more easily capture the native leaflet. The p reloading of the tongue411provides a significant advantage over prior art clips that provide little or no pinching force when closed. Additionally, closing the clasp400with spring force is a significant improvement over clips that use a one-time locking closure mechanism, as the clasp400can be repeatedly opened and closed for repositioning on the leaflet while still maintaining sufficient pinching force when closed.

The barbed portion440of the moveable arm430includes an eyelet442, barbs444, and barb supports446. Positioning the barbed portion of the clasp400at an end of the moveable arm430increases the space between the barbs444and the fixed arm410when the clasp400is opened, thereby improving the ability of the clasp400to successfully capture a leaflet during implantation. This distance also allows the barbs444to more reliably disengage from the leaflet for repositioning. In certain embodiments, the barbs of the clasps may be staggered longitudinally to further distribute pinch forces and local leaflet stress.

The barbs444are laterally spaced apart at the same distance from the hinge portion420, providing a superior distribution of pinching forces on the leaflet tissue while also making the clasp more robust to leaflet capture than barbs arranged in a longitudinal row. In some embodiments, the barbs444can be staggered to further distribute pinch forces and local leaflet stress.

The barbs444are formed from the bottom layer404and the barb supports446are formed from the top layer. In certain embodiments, the barbs are formed from the top layer402and the barb supports are formed from the bottom layer404. Forming the barbs444only in one of the two layers402,404allows the barbs to be thinner and therefore effectively sharper than a barb formed from the same material that is twice as thick. The barb supports446extend along a lower portion of the barbs444to stiffen the barbs444, further improving penetration and retention of the leaflet tissue. In certain embodiments, the ends of the barbs444are further sharpened using any suitable sharpening means.

The barbs444are angled away from the moveable arm430such that they easily penetrate tissue of the native leaflets with minimal pinching or clipping force. The barbs444extend from the moveable arm at an angle of about 45 degrees to about 75 degrees, or about 45 degrees to about 60 degrees, or about 48 to about 56 degrees, or about 52 degrees. The angle of the barbs444provides further benefits, in that force pulling the implant off of the native leaflet will encourage the barbs444to further engage the tissue, thereby ensuring better retention. Retention of the leaflet in the clasp400is further improved by the position of the T-shaped cross bar414near the barbs444when the clasp400is closed. In this arrangement, the tissue pierced by the barbs444is pinched against the moveable arm430at the cross bar414location, thereby forming the tissue into an S-shaped torturous path as it passes over the barbs444. Thus, forces pulling the leaflet away from the clasp400will encourage the tissue to further engage the barbs444before the leaflets can escape.

Each layer402,404of the clasp400is laser cut from a sheet of shape-memory alloy, such as Nitinol. The top layer402is aligned and attached to the bottom layer404. In certain embodiments, the layers402,404are attached at the barbed end440of the moveable arm430. For example, the layers402,404may be attached only at the barbed end440, to allow the remainder of the layers to slide relative to one another. Portions of the combined layers402,404, such as a fixed arm410, barbs444and barb supports446, and beam loops422are bent into a desired position. The layers402,404may be bent and shapeset together or may be bent and shapeset separately and then joined together. The clasp400is then subjected to a shape-setting process so that internal forces of the material will tend to return to the set shape after being subjected to deformation by external forces. After shape setting, the tongue411is moved to its preloaded position so that the cross-bar414can be attached. Consequently, the clasp400can be completely flattened for delivery through a delivery sheath and allowed to expand once deployed within the heart.

The clasp400is opened and closed by applying and releasing tension on an actuation means such as an actuation line, suture, wire, rod, catheter, or the like (not shown) attached to the moveable arm430. The suture is inserted through an eyelet442near the barbed portion440of the moveable arm430and wraps around the end of the moveable arm430before returning to the delivery sheath. In certain embodiments, an intermediate suture loop is made through the eyelet and the suture is inserted through the intermediate loop. An intermediate loop of suture material reduces friction experienced by the actuation suture relative to the friction between the actuation suture and the clasp material. When the suture is looped through the eyelet442or intermediate loop, both ends of the actuation suture extend back into and through the delivery sheath102(seeFIG.1). The suture can be removed by pulling one end of the suture proximally until the other end of the suture pulls through the eyelet or intermediate loop and back into the delivery sheath.

Referring now toFIG.27, an exemplary barbed clasp500for use in implantable prosthetic devices, such as devices100,200,300described above, is shown. The barbed clasp500is substantially the same as the barbed clasp400, except the barbed clasp500includes a suture pin543disposed across an opening542, instead of the hole442. The barbed clasp500is formed from a top layer502and a bottom layer504. The two-layer design of the clasp500allow thinner sheets of material to be used, thereby improving the flexibility of the clasp500over a clasp formed from a single thicker sheet, while maintaining the strength of the clasp500needed to successfully retain a native valve leaflet.

The barbed clasp500includes a fixed arm510, a hinged portion520, and a movable arm530having a barbed portion540. The top and bottom layers502,504have a similar shape and in certain embodiments are attached to each other at the barbed end540. The hinged portion520is spring-loaded so that the fixed and moveable arms510,530are biased toward each other when in the barbed clasp500is in a closed condition. When assembled to an implantable prosthetic device, the fixed arm510is attached to a portion of the prosthetic device. The clasp500is opened by pulling on an actuation means or actuation line attached to the moveable arm530until the spring force of the hinge portion520is overcome.

The fixed arm510is formed from a tongue511of material extending from the hinged portion520between two side beams531of the moveable arm530. The tongue511is biased between the side beams531by the hinge portion520such that force must be applied to move the tongue511from a neutral position located beyond the side beams531to a preloaded position substantially parallel with the side beams531. The tongue511is held in the preloaded position by a T-shaped cross-bar514that is attached to the tongue511and extends outward to engage the side beams531. In certain embodiments, the angle between the fixed and moveable arms510,530when the tongue is in the neutral position is about 30 to about 100 degrees, or about 30 to about 90 degrees, or about 30 to about 60 degrees, or about 40 to about 50 degrees, or about 45 degrees.

The tongue511includes holes512for receiving sutures (not shown) that attach the fixed arm510to an implantable device. The fixed arm510may be attached to an implantable device by various attaching means, such as screws or other fasteners, crimped sleeves, mechanical latches or snaps, welding, adhesive, or the like. In certain embodiments, the holes512are elongated slots or oval-shaped holes to accommodate sliding of the layers502,504without damaging the sutures attaching the clasp500to an implantable device.

The hinge portion520is formed by two beam loops522that extend from the tongue511of the fixed arm510to the side beams531of the moveable arm530. In certain embodiments, the beam loops522are narrower than the tongue511and side beam531to provide additional flexibility. The beam loops522each include a center portion524extending from the tongue511and an outer portion526extending to the side beams531. The beam loops522are bent into a somewhat spiral or helical shape by bending the center and outer portions524,526in opposite directions, thereby forming a step distance528between the tongue511and side beams531. The step distance528provides space between the arms510,530to accommodate the native leaflet of the mitral valve after it is captured. In certain embodiments, the step distance528is about 0.5 millimeter to about 1 millimeters, or about 0.75 millimeters.

When viewed in a top plan view, the beam loops have an “omega-like” shape. This shape of the beam loops522allows the fixed and moveable arms510,530to move considerably relative to each other without plastically deforming the clasp material. For example, in certain embodiments, the tongue511can be pivoted from a neutral position that is approximately 45 degrees beyond the moveable arm530to a fully open position that ranges from about 140 degrees to about 200 degrees, to about 170 degrees to about 190 degrees, or about 180 degrees from the moveable arm530without plastically deforming the clasp material. In certain embodiments, the clasp material plastically deforms during opening without reducing the pinch force exerted between the fixed and moveable arms in the closed position.

Preloading the tongue511enables the clasp500to maintain a pinching or clipping force on the native leaflet when closed while also being able to be opened wide to more easily capture the native leaflet. The p reloading of the tongue511provides a significant advantage over prior art clips that provide little or no pinching force when closed. Additionally, closing the clasp500with spring force is a significant improvement over clips that use a one-time locking closure mechanism, as the clasp500can be repeatedly opened and closed for repositioning on the leaflet while still maintaining sufficient pinching force when closed.

The barbed portion540of the moveable arm530includes an eyelet542, barbs544, and barb supports546. Positioning the barbed portion of the clasp500at an end of the moveable arm530increases the space between the barbs544and the fixed arm510when the clasp500is opened, thereby improving the ability of the clasp500to successfully capture a leaflet during implantation. This distance also allows the barbs544to more reliably disengage from the leaflet for repositioning. In certain embodiments, the barbs of the clasps may be staggered longitudinally to further distribute pinch forces and local leaflet stress.

The barbs544are laterally spaced apart at the same distance from the hinge portion520, providing a superior distribution of pinching forces on the leaflet tissue while also making the clasp more robust to leaflet capture than barbs arranged in a longitudinal row.

The barbs544are formed from the bottom layer504and the barb supports546are formed from the top layer. Forming the barbs544only in one of the two layers502,504allows the barbs to be thinner and therefore effectively sharper than a barb formed from the same material that is twice as thick. The barb supports546extend along a lower portion of the barbs544to stiffen the barbs544, further improving penetration and retention of the leaflet tissue. In certain embodiments, the ends of the barbs544are further sharpened using any suitable sharpening means.

The barbs544are angled away from the moveable arm530such that they easily penetrate tissue of the native leaflets with minimal pinching or clipping force. The barbs544extend from the moveable arm at an angle of about 45 to about 75 degrees, or about 45 to about 60 degrees, or about 48 to about 56 degrees, or about 52 degrees. The angle of the barbs544provides further benefits, in that force pulling the implant off of the native leaflet will encourage the barbs544to further engage the tissue, thereby ensuring better retention. Retention of the leaflet in the clasp500is further improved by the position of the T-shaped cross bar514near the barbs544when the clasp500is closed. In this arrangement, the tissue pierced by the barbs544is pinched against the moveable arm530at the cross bar514location, thereby forming the tissue into an S-shaped torturous path as it passes over the barbs544. Thus, forces pulling the leaflet away from the clasp500will encourage the tissue to further engage the barbs544before the leaflets can escape.

Each layer502,504of the clasp500is laser cut from a sheet of shape-memory alloy, such as Nitinol. The top layer502is aligned and attached to the bottom layer504. In certain embodiments, the layers502,504are attached at the barbed end540of the moveable arm530. For example, the layers402,404may be attached only at the barbed end440, to allow the remainder of the layers to slide relative to one another. Portions of the combined layers502,504, such as a fixed arm510, barbs544and barb supports546, and beam loops522are bent into a desired position. The clasp500is then subjected to a shape-setting process so that internal forces of the material will tend to return to the set shape after being subjected to deformation by external forces. After shape setting, the tongue511is moved to its preloaded position so that the cross-bar514can be attached. Consequently, the clasp500can be completely flattened for delivery through a delivery sheath and allowed to expand once deployed within the heart.

The clasp500is opened and closed by applying and releasing tension on an actuating means such as an actuation line, suture, wire, rod, catheter, or the like (not shown) attached to the moveable arm530. The suture is inserted through an opening542in the moveable arm530and looped around a pin543disposed in the opening542. The smooth round shape of the pin543allows tension to be applied to the moveable arm530from many directions without causing the suture to wear. In certain embodiments, an intermediate suture loop is made through the opening and around the pin and the suture is inserted through the intermediate loop. An intermediate loop of suture material reduces friction experienced by the actuation suture relative to the friction between the actuation suture and the clasp material. When the actuation suture is looped around the pin543, both ends of the suture extend back into and through the delivery sheath102(seeFIG.1). The suture can be removed by pulling one end of the suture proximally, until the other end of the suture pulls around the pin543and back into the delivery sheath.

Referring now toFIGS.28-31, an exemplary barbed clasp600similar to barbed clasps400and500is shown in a variety of bent positions to illustrate the independent movement of the layers forming the barb clasps400,500, and600. The barbed clasp600is formed from a top layer602and a bottom layer604. The barbed clasp600includes a moveable arm620, a fixed arm622, a hinge portion624. The moveable arm620includes a barbed portion626with barbs628. The barbed clasp600does not include a cross-bar to prevent the moveable arm620from moving past the fixed arm622. Instead of a cross-bar, the moveable arm620is held in a closed position with the fixed arm622by the inner paddle (not shown). To better illustrate the preloading of the clasp600,FIGS.28-31show the fixed arm622moving relative to a stationary moveable arm620. When assembled to an implantable device, however, the moveable arm620would move relative to the fixed arm622that is attached to the device.

Referring now toFIGS.28-29, the clasp600is shown in a preloading or shape setting condition. The fixed arm622is bent below the moveable arm620by an angle610before the shape setting operation is performed. Force must be applied then to return the fixed arm622to a parallel relationship with the moveable arm620. Thus, increasing the preloading angle610increases the force required to move the fixed arm622, thereby increasing the preloading spring force pinching the arms620,622together when the clasp600is closed. In other words, the greater the angle610, the greater the spring force applied to captured tissue by the arms620,622.

Referring now toFIGS.30-31, the clasp600is shown being opened to an opening angle612. As can be seen inFIGS.30and31, the beam loops of the hinge portion624tend to separate as the clasp600is opened. Allowing the layers602,604to separate during bending decreases strain on the material, thereby further increasing the maximum opening angle612that can be achieved before plastic deformation of the clasp material. As noted above, the hinge portion624is shaped to form somewhat spiral or helical beam loops, thereby forming a gap or step distance614between the arms620,622(FIG.29) that allows the leaflet tissue to be captured.

As the clasp600is opened, the layers602,604in the fixed arm622slide relative to each other. In some embodiments, holes through the fixed arm622are elongated so that sutures securing the fixed arm622to the implantable device are not pinched by the sliding movement of the layers, nor are the layers602,604constrained from sliding, which reduces strain experienced by the clasp material.

Referring now toFIGS.32-35, exemplary barb clasps700,800,900, and1000are shown. Barb clasps700,800,900, and1000, like clasps400,500,600can be used in the implantable devices100,200, and300described above. Unlike barbed clasps400,500,600, however, barbed clasps700,800,900, and1000are formed by laser cutting material from the side of the clasp rather than from the top. Laser cutting from the side reduces the operations required to manufacture the clasp and allows the thickness of the clasp to be varied to vary the bending properties of portions of the clasp based on the function of each portion. For example, hinge portions may be thinner to provide more flexibility while arms may be thickened to provide more stiffness.

Referring now toFIG.32, a laminated barb clasp700is shown. The barb clasp700has thick and thin portions702,704and is formed from alternating spacer layers706and barbed layers708to form a laminated structure. The clasp700includes a moveable arm720, a fixed arm722, and a hinge portion724. The moveable arm720includes a barbed portion726having barbs728formed in the barbed layers708. Forming the layers706,708by laser cutting from a side profile allows the barbs728to be tapered, thereby providing a stiff barb with a sharp point. The fixed arm722includes holes to secure the clasp700to an implantable device. When assembled to an implantable device, the fixed arm722is extended by the attached inner paddle, thus the native tissue is pinched between the moveable arm720and the inner paddle of the device. The moveable and fixed arms720,722are formed at an angle relative to each other such that an extension of the fixed arm722would intersect with the moveable arm720. Attaching the fixed arm722to the inner paddle effectively extends the end of the fixed arm722such that the inner paddle would interfere with the moveable arm720. The interference of the components causes the moveable arm720to be moved relative to the fixed arm722such that the clasp700is opened, thereby preloading the moveable arm722such that a pinch force is applied against the inner paddle when the clasp700is in the closed position. Thus, a pinch force is created between the moveable and fixed arms720,722without shapesetting the moveable and fixed arms720,722of the clasp700. Alternatively, the individual layers are formed with the moveable and fixed arms720,722parallel to each other and are then bent and shapeset such that the moveable arm720is biased toward the fixed arm722when the clasp700is affixed to the inner paddle.

Referring now toFIGS.33-35, exemplary barb clasps800,900,1000are shown. The clasps800,900,1000are similar in overall shape while illustrating the variety of thicknesses possible when laser cutting clasps from the side. The clasps800,900,1000have a thin portion804,904,1004and a thick portion802,902,1002. The clasps800,900,1000include a moveable arm820,920,1020, a fixed arm822,922,1022, a hinge portion824,924,1024. The moveable arm820,920,1020includes a barb portion826,926,1026having barbs (not shown) similar to the barbs728of the barb portion726of clasp700. As can be seen inFIGS.33-35, holes can be provided in the fixed arm822,922,1022to secure the clasp800,900,1000to an implantable device. When assembled to an implantable device, the fixed arm822,922,1022is extended by the attached inner paddle, thus the native tissue is pinched between the moveable arm820,920,1020and the inner paddle of the device.

Referring now toFIG.36, an exemplary barbed clasp1100similar to barbed clasps400,500,600is shown. Unlike barbed clasps400,500,600, however, barbed clasp1100is formed from a single layer of material that varies in thickness between a thick portion1102and a thin portion1104. The barbed clasp1100includes a fixed arm1110, a hinge portion1120, and a moveable arm1130. The fixed arm1110includes attachment holes1112and an optional integrated crossbar1114. The hinge portion1120includes an arcuate hinge1122formed from the thin portion1104. The moveable arm1130includes a barbed portion1140with barbs1144. A suture (not shown) can be attached to an eyelet1142near the barbed portion1140to open and close the clasp1100.

To form the barbed clasp1100, a sheet of material is thinned to form the thin portion1104. The shape of the clasp1100is then laser cut from the sheet of material so that the hinge portion1120is aligned with the thin portion1104. The barbs1144and fixed arm1110are then bent into the position shown inFIG.36before shape setting. The optional T-shaped crossbar1114of the fixed arm1110must be twisted to insert it through the slot in the moveable arm1130for shape setting and to move the arms1110,1130from the preloading position to a closed position. In certain embodiments, the optional T-shaped crossbar1114is omitted, is smaller, or is alternatively replaced with a relief in the moveable arm1130, to facilitate ease of manufacture and shape setting. After the shape setting, the crossbar is twisted, moved back through the slot, and positioned on top of the thick portion1102. The crossbar1114is positioned in generally the same manner as the crossbar414(seeFIG.26).

Like the clasps400,500described above, the clasp1100can be opened fully without plastically deforming the clasp material while still providing pinching force when closed. Fewer steps are required to manufacture the clasp1100as compared to the clasps above, as the clasp1100is cut from a single sheet of material and no welding step is needed to weld layers of material together.

Referring now toFIGS.37-52, an exemplary barbed clasp1200for use in implantable prosthetic devices, such as devices100,200,300described above, is shown. The barbed clasp1200is formed from a single layer1202of material. The barbed clasp1200includes a fixed arm1210, a hinged portion1220, and a movable arm1230having a barbed portion1240. The hinged portion1220is spring-loaded so that the fixed and moveable arms1210,1230are biased toward each other when the barbed clasp1200is in a closed condition. When assembled to an implantable prosthetic device, the fixed arm1210is attached to a portion of the prosthetic device. The clasp1200is opened by pulling on an actuating mans such as an actuation line or suture attached to the moveable arm1230until the spring force of the hinge portion1220is overcome.

The fixed arm1210is formed from a tongue1211of material extending from the hinged portion1220between two side beams1231of the moveable arm1230to an end1214. In some embodiments, the moveable arm is formed from a tongue of material that extends between two side beams of the fixed arm. The tongue1211is biased between the side beams1231by the hinge portion1220such that force must be applied to move the tongue1211from a neutral position located beyond the side beams1231to a preloaded position that is nearly parallel or parallel with the side beams1231, as can be seen inFIGS.39-40E. The tongue1211is held in the preloaded position when it is attached to a paddle of an implantable prosthetic device. The end1214of the tongue1211may optionally have a T-shape cross-member that engages the side beams1231to hold the tongue1211in the preloaded position.

In certain embodiments, the angle between the fixed and moveable arms1210,1230when the tongue1211is in the neutral position is about 30 to about 120 degrees, 40 to about 110 degrees, or about 50 to about 100 degrees, or about 60 to about 90 degrees, or about 90 degrees. The tongue1211includes holes1212for receiving sutures (not shown) that attach the fixed arm1210to an implantable device.

The hinge portion1220is formed by a plurality of torsional spring segments1222arranged in a repeating pattern extending from the tongue1211of the fixed arm1210to the side beams1231of the moveable arm1230. Each spring segment1222is joined with other spring segments1222to form a repeating pattern. Joining multiple segments1222together allows the hinge portion1220to bend a considerable amount while avoiding plastic deformation of the material as the individual torsional spring segments1222are twisted. For example, in certain embodiments, the tongue1211can be pivoted from the neutral position that is approximately 90 degrees beyond the moveable arm1230to a fully open position that ranges from about 140 degrees to about 200 degrees, to about 170 degrees to about 190 degrees, or about 180 degrees. from the moveable arm1230without plastically deforming the clasp material. In certain embodiments, the clasp material can plastically deform during opening without reducing or without substantially reducing the pinch force exerted between the fixed and moveable arms in the closed position. The pattern spring segments1222are formed from open and closed cutouts1224in the hinge portion1220. Exemplary spring segments and their arrangement in a pattern are described below and shown inFIGS.51A-52.

Preloading the tongue1211enables the clasp1200to maintain a pinching or clipping force on the native leaflet when closed while also being able to be opened wide to more easily capture the native leaflet. The preloading of the tongue1211provides a significant advantage over prior art clips that provide little or no pinching force when closed. Additionally, closing the clasp1200with spring force is a significant improvement over clips that use a one-time locking closure mechanism, as the clasp1200can be repeatedly opened and closed for repositioning on the leaflet while still maintaining sufficient pinching force when closed.

The barbed portion1240of the moveable arm1230includes eyelets1242and barbs1244. Positioning the barbed portion of the clasp1200at an end of the moveable arm1230increases the space between the barbs1244and the fixed arm1210when the clasp1200is opened, thereby improving the ability of the clasp1200to successfully capture a leaflet during implantation. This distance also allows the barbs1244to more reliably disengage from the leaflet for repositioning. In certain embodiments, the barbs of the clasps may be staggered longitudinally to further distribute pinch forces and local leaflet stress. In certain embodiments, the ends of the barbs1244are further sharpened using any suitable sharpening means.

The barbs1244are laterally spaced apart at the same distance from the hinge portion1220, providing a superior distribution of pinching forces on the leaflet tissue while also making the clasp more robust to leaflet capture than barbs arranged in a longitudinal row. In some embodiments, the barbs1244can be staggered to further distribute pinch forces and local leaflet stress.

The barbs1244are angled away from the moveable arm1230at an angle1246(FIG.38A) such that they easily engage tissue of the native leaflets with minimal pinching or clipping force. During use, the barbs1244may penetrate the native leaflet tissue, though penetration of the tissue is not necessary for the clasp1200to securely grasp the leaflets. The barbs1244extend from the moveable arm at an angle1246of about 20 degrees to about 90 degrees, or about 40 degrees to about 70 degrees, or about 50 to about 60 degrees, or about 53 degrees. The angle of the barbs1244provides further benefits, in that force pulling the implant off of the native leaflet will encourage the barbs1244to further engage the tissue, thereby ensuring better retention. Retention of the leaflet in the clasp1200is further improved by the position of the end1214of the fixed arm1210when the clasp1200is closed. In this arrangement, the tissue engaged by the barbs1244is pinched against the moveable arm1230at the end1214location, thereby forming the tissue into an S-shaped torturous path as it passes over the barbs1244. Thus, forces pulling the leaflet away from the clasp1200will encourage the tissue to further engage the barbs1244before the leaflets can escape. The end1214can optionally be shapeset with a slight bend toward the moveable arm1230to accentuate the S-shape of the tortuous path of the tissue captured between the fixed and moveable arms1210,1230.

The layer of material1202of the clasp1200is laser cut from a sheet of shape-memory alloy, such as Nitinol. Portions of the layer1202, such as the fixed arm1210, hinge portion1220and barbs1244are bent into a desired position. The clasp1200is then subjected to a shape-setting process so that internal forces of the material will tend to return to the set shape after being subjected to deformation by external forces. After shape setting, the tongue1211is moved to its preloaded, closed, or open positions to be attached to the implantable device. Consequently, the clasp1200can be substantially flattened in the closed position for delivery through a delivery sheath and allowed to expand once deployed within the heart.

The clasp1200is opened and closed by applying and releasing tension on an actuation line or suture (e.g., suture2504ofFIG.71) attached to the moveable arm1230. The suture is inserted through at least one of the eyelets1242located near the barbed portion1240of the moveable arm1230before returning to the delivery sheath. In certain embodiments, an intermediate suture loop is made through one or more of the eyelets1242and the actuation suture is inserted through one or more of the intermediate loops. An intermediate loop of suture material reduces friction experienced by the actuation suture relative to the friction between the actuation suture and the clasp material. When the suture is looped through the eyelet1242or intermediate loop, both ends of the actuation suture extend back into and through the delivery sheath102(see, e.g.,FIG.1). The suture can be removed by pulling one end of the suture proximally until the other end of the suture pulls through the eyelet or intermediate loop and back into the delivery sheath.

Like the clasps400,500described above, the clasp1200can be opened fully without plastically deforming the clasp material while still providing pinching force when closed. Fewer steps are required to manufacture the clasp1100as compared to the clasps above, as the clasp1200is cut from a single sheet of material and no welding step is needed to weld layers of material together.

Referring now toFIGS.37-48E, the clasp1200is shown in various bending positions ranging from a neutral position (FIGS.37-38E) to a fully open position (FIGS.47-48E). Though the fixed arm1210is shown in different positions inFIGS.37-48E, once installed in an implantable device, the moveable arm1230is actuated by the surgeon to move relative to the device while the fixed arm1210remains stationary relative to the device.

FIGS.37-38Eshow the clasp1200in the neutral position for shape-setting. During shape-setting, the tongue1211of the fixed arm1210is bent to a tongue angle1216that is about 60 degrees to about 120 degrees, or about 90 degrees below the side beams1231of the moveable arm1230. After shape-setting, the tongue1211remains in the shape-setting or neutral position unless acted upon by forces to move the tongue1211into other positions. Thus, when the tongue1211is moved to a preloading or closed position (FIGS.39-40E) internal forces of the clasp material are exerted in the closing direction, thereby generating a pinching force when the clasp1200is in the closed or preloaded condition. During implantation of a medical device including the clasp1200, the moveable arm1230is actuated with a suture (not shown) to change the angle1216between the fixed and moveable arms1210,1230. The clasp1200is shown in a one-quarter open condition inFIGS.41-42E, a half open condition inFIGS.43-44E, a three-quarter open condition inFIGS.45-46E, and a fully open condition inFIGS.47-48E. The angle1216between the fixed and moveable arms1210,1230in the fully open position may be about 140 degrees to about 200 degrees, to about 170 degrees to about 190 degrees, or about 180 degrees. That is, the clasp1200is capable of being opened substantially completely flat without plastic deformation of the clasp material.

Referring now toFIGS.49-50, the layer1202of material for forming the clasp1200is shown in a pre-shape setting condition, that is, in a substantially flat condition after being laser cut from a sheet of material.FIG.50in particular clearly shows the repeating nature of the pattern of spring segments1222and cutouts1224that form the hinge portion1220.

Referring now toFIGS.51A-51D, exemplary torsional spring segments1300,1400,1500,1600for a patterned hinge portion (e.g., hinge portion1220of the clasp1200) are shown. The spring segments1300,1400,1500,1600are arrangeable in a repeating pattern that is cut out of a single piece so that there are no physical seams between the individual segments. Thus, the shape of the spring segments1300,1400,1500,1600is defined by the cutouts in the hinge portion and imaginary boundaries at the “joints” between segments.

Referring now toFIG.51A, the spring segment1300is formed by cutouts1301made in a layer1302of material resulting in a substantially rotationally symmetric, S-like shape. Each spring segment1300extends from a first end1310to a second end1320between a first side1330and a second side1340. A first end joining location1312is located at the first end1310adjacent the first side1330. A first side joining location1332is located at the first side1330adjacent the first end1310. A second end joining location1322is located at the second end1320adjacent the second side1340. A second side joining location1342is located at the second side1340adjacent the second end1320. Side surface1304extend between the first end joining location1312and the second side joining location1342, and between the second end joining location1322and the first side joining location1332. An inner corner1306is formed near each side joining location1332,1342.

Referring now toFIGS.51B-51D, spring segments1400,1500,1600are shown. These spring segments1400,1500,1600are similar in structure to the spring segment1300described above, though spring segments1400,1500,1600include an outer corner1408,1508,1608near each end joining location opposite the side joining location. The shapes of the spring segments1300,1400,1500,1600vary in the size and shape of the side surfaces1304,1404,1504,1604, rounded inner corners1306,1406,1506,1606and rounded outer corners1408,1508,1608. For example, the side surfaces1304,1404are substantially straight, while the side surfaces1504,1604are concave. These differences in shape change the stress distribution in hinge portions formed from a pattern of the differently shaped spring segments.

Referring now toFIG.52, an exemplary spring grouping1700of spring segments1300is shown. As can be seen inFIG.52, side joining locations1332,1342are joined to other side joining locations1332,1342and end joining locations1312,1322are joined to other end joining locations1312,1322. The substantially rotationally symmetric shape of the spring segments1300allows either end1310,1320or side1330,1340of one segment to be joined to either end1310,1320or side1330,1340of another segment. Various patterns may then be formed, such as the H-pattern formed by the grouping1700inFIG.52. While the segments1300,1400,1500,1600are substantially rotationally symmetric, individual segments in a pattern of segments may be modified to form rounded outer edges of a hinge portion or to adapt to the fixed or moveable arm of a clasp.

When the spring grouping1700is subjected to a bending force1710each of the segments1300is twisted in the direction indicated by the arrows1720. Consequently, the individual spring segments1300are subjected to torsional strain and not bending strain. One can also see that the deformation of the material1302is reduced relative to the bending of a flat sheet of material being bent in a similar manner while maintaining the spring force of the hinge portion of the clasp. As a result, a hinge portion formed from a pattern of torsional spring segments is strong and flexible.

To form a patterned hinge portion, such as the hinge portion1220described above, a pattern comprising plurality of spring segments are arranged in rows and columns. The spring segments are arranged with their longitudinal and lateral axes in the same orientation, as can be seen inFIGS.49-50and52. In certain embodiments, the spring segments may be rotated relative to each other to form different spring patterns. The spring segments are organized into columns and rows. Columns are defined along the longitudinal axis of the clasp, while rows are defined along the lateral axis of the clasp. Thus, a column of spring segments is as wide as the longest dimension of an individual spring segment, while a row of spring segments has a height equal to the shortest dimension of an individual spring segment. For example, the clasp1200shown inFIG.50includes three columns and seven rows of spring segments (not including partial rows connecting the hinge portion to the fixed and moveable arms). Where the ends of segments border an edge of the clasp, two segments in adjacent rows are joined together at one location, forming a U-shaped grouping. Individual spring segments or groupings of spring segments may be modified away from their rotational symmetry to increase the smoothness and/or robustness of the edges of the hinge portion. Where the ends of segments are located at an intersection of two columns, the segments may join up to three other segments, forming an X-shaped grouping, like the grouping1700shown inFIG.62. The patterned hinge may include any suitable number of rows and columns of spring segments. The size and shape of each segment may be adjusted to adjust the spring parameters of the patterned hinge. The size and shape of the spring segments may be uniform throughout the patterned hinge or may vary based on the location of the spring segment within the pattern.

Referring now toFIGS.53-55, an exemplary barb clasp1800is shown that is cut from a tube of material1802using four-axis laser cutting (X, Y, Z, and rotation axes) and five-axis laser cutting (X, Y, Z, and two tilt-axes for the laser head). The tube can first be cut into segments and then each segment is cut in generally the same way that a flat piece of stock or blank material is cut; that is, the tube provides a curved blank instead of a flat blank. The additional degrees of freedom of the laser cutter allow the tube to be rotated or the head of the laser cutter to be tilted during laser cutting. Rotating the tube or tilting the laser cutting head allows the barbs to be cut in the sharper barb configuration shown inFIG.55without requiring a separate sharpening operation. The clasp1800is similar in structure to the clasp1200, described in detail above. The tube of material802has an inner radius1804, an inner surface1801, and an outer surface1803. Cutting the clasp1800from a tube of material1802provides a cupped or concave profile when viewed from the end, as shown inFIG.54. One effect of the concave profile is that the elongated portions of the fixed and moving arms1810,1830increasing their stiffness, without substantially impacting the flexibility of the hinge portion1820. The concave profile also results in barbs1844with sharper points or tips1846without a separate sharpening operation—i.e, the barbs are formed with a beveled edge without sharpening. The sharp points1846enable improved engagement with the native leaflet tissue. Referring toFIG.55, the sharp points1846are formed during laser cutting because the cutting planes that form first and second sides1847,1848of the barbs1844to intersect at the tip1846, thereby forming a triangular pyramid shape that comes to a point that is not possible when the cutting planes that form the sides of the barb are parallel and do not intersect. Thus, the barbs1844of the clasp1800have a strong base1845and a sharp point1846in a single layer of material, without any secondary sharpening operation.

Referring now toFIG.56, an exemplary clasp1900is shown. The clasp1900is similar in structure to the clasp1200, described in detail above with a differently structured hinge portion1920. The hinge portion1920includes a plurality of beams1922formed by a series of elongated cuts1924. Referring now toFIGS.56A-56B, alternate embodiments of the beams1922of the hinge portion1920are shown.FIG.56Ashows the rectangular beam1922having a bent portion1926.FIG.56Bshows the rectangular beam1922having a bent portion1926that is also twisted about 90 degrees such that the cross-section of the beam in the bent portion1926is perpendicular to the portions of the beam1922at its ends. Twisting the beam1922, as shown inFIG.56B, reduces the bending strain in the beam1922thereby increasing its flexibility.

Referring now toFIGS.57-58, an exemplary barbed clasp2000for use in implantable prosthetic devices, such as devices100,200,300described above, is shown. The barbed clasp2000includes a fixed arm2010that is attached to the implantable device. The barbed clasp2000differs from other clasps in that the clasp2000includes a plurality of movable arms2030that each have a hinged portion2020and a barbed portion2040having a single barb2042. The independent arms2030of the clasp2000individually pinch the tissue of the native leaflet which allows for improved engagement of tissue that is not uniform in thickness. The arms2030can also be shape set in a wide or spread out arrangement and crimped down into a narrow configuration for deployment so that the barbs2042can be spaced apart laterally more than would be possible if the arms were rigidly connected. In certain embodiments, the arms2030include an optional hole or notch (not shown) that can be engaged by an actuation suture to cinch the arms2030together during deployment.

The fixed arm2010is formed from a tongue2011from which beams2031that form the moveable arms2030extend. The hinge portions2020are formed by bending each of the beams2031to form a bent portion2022. The hinged portions2020are spring-loaded so that the fixed and moveable arms2010,2030are biased toward each other when the barbed clasp2000is in a closed condition. In certain embodiments, the tongue2011is formed from a wide plate of material to provide a larger lateral area as a pinching location for the independent arms2030.

The barbed clasp2000is laser cut from a layer2002of shape-memory alloy, such as Nitinol. As is shown inFIG.57A, the barbs2042lay flat in the same plane as the rest of the clasp2000when cut out of the layer2002of material. The moveable arms2030and barbs2040are then bent and twisted into the shape shown inFIG.57and are then subjected to a shape setting process. As noted above, the independent arms2030of the clasp2000can be shape set as wide or narrow as desired. In certain embodiments individual arms2030may be longer or shorter than others, and the spacing of the arms2030may vary or be uniform.

Cutting the barbs2042out of the sheet of material and then twisting them into position also allows larger barbs of a variety of shapes to be formed. In certain embodiments, the barbed portions2040may include multiple smaller barbs arranged in series that may or may not be facing in the same direction. In certain embodiments, the ends of the barbs2042are further sharpened using any suitable sharpening means. In certain embodiments, the hinge portions2020of the beams2031include twisted portions2024. The twisted portions2024may act as torsional springs that resist lateral forces applied to the ends of the barbs2042, thereby helping to maintain the alignment of the barbs2042when engaging the tissue of the native leaflets.

Referring now toFIGS.59-63, an exemplary clasp2100for use in implantable prosthetic devices, such as devices100,200,300described above, is shown. The clasp2100is expandable between a collapsed condition and an expanded condition and is shape set in the expanded condition so that the clasp2100automatically expands from the collapsed condition to the expanded condition. As can be seen inFIG.61A, the clasp2100can be deployed from a delivery sheath2150in the collapsed condition and allowed to self-expand into the expanded condition.

The clasp2100has many features that are similar to the clasp1200, described in detail above, such as a patterned hinge portion2120formed by a plurality of spring segments2122and cutouts2124and a fixed arm2110that includes a tongue2111having holes2112for attaching the fixed arm2110to the implantable device and an end2114having a T-shape to retain the fixed arm2110in a preloaded position. The clasp2100also has a moveable arm2130that includes a barbed portion2140with a plurality of barbs2142.

The hoop-like shape of the moveable arm2130provides for a wider barbed portion2140that can include more barbs2142with the same or greater lateral spacing than other clasps. The wider spacing of the barbs2142improves capture of the native leaflets. In certain embodiments, the hoop shape of the moveable arm2130is similar to the shape of wide outer paddles of an implantable device so that pinching forces of the paddles are spread out evenly on the barbs, further improving the retention of the native leaflets. Some of the barbs2142may also be longitudinally staggered as a result of their position on the hoop-like shape of the moveable arm2130. In certain embodiments, the ends of the barbs2042are further sharpened using any suitable sharpening means. In certain embodiments, the tongue2111is formed from a wide plate of material to provide a larger lateral area as a pinching location.

The moveable arm2130is provided in the shape of a hoop or loop. The moveable arm2130includes side beams2131that are thinner and more flexible, particularly in the lateral direction, than the side beams1231of the clasp1200described above. The side beams2131include a first hinge portion2132arranged toward the proximate end of the moveable arm2130and a second hinge portion2136arranged at the distal end of the moveable arm2130. The first hinge portion2132is formed by one or more bends in the side beams2132. In certain embodiments, the second hinge portion2136includes a thinner—and therefore more flexible—portion to reduce the force required to collapse the clasp2100. The moveable arm2130includes holes2134arranged between the first and second hinge portions2132,2136for receiving the actuation sutures2152that are used to collapse the moveable arm2130. The holes2134are arranged further laterally from the center of the clasp2130than the hinge portions2132,2136to provide mechanical advantage when force is applied via the sutures2152. In certain embodiments, the holes2134are located at the lateral-most location of the side beams2131.

The rounded hoop shape of the clasp2100allows the clasp2100to be collapse by merely retracting the clasp2100into the delivery sheath. In certain embodiments, the expansion and contraction of the clasp2100is controlled by actuation sutures2152. The sutures2152may be routed through an aperture2156of a guide2154to holes2134in the moveable arm2130to control the direction in which the force applied along the suture2152is applied to cinch the moveable arm2130into a collapsed position. For example, arranging the guide2154closer to the connection point to the sutures2152to the clasp2100causes the forces applied to the clasp2100by the sutures2152to be directed in a more lateral rather than longitudinal direction. Alternatively, as can be seen inFIG.61B, a single suture loop2153can be routed through the aperture2156of the guide2154, through each of the holes2134in the moveable arm2130, and then back through the guide2154so that actuation of the single loop2153cinches the moveable arm2130into a collapsed position.

Referring now toFIGS.64-68, an exemplary barbed clasp2200for use in implantable prosthetic devices, such as devices100,200,300described above, is shown. The barbed clasp2200includes elements of clasps1200,2000described above. The barbed clasp2200includes a fixed arm2210that is attached to the implantable device and a hinge portion2220that allows the clasp2200to open and close. The hinge portion2220is formed from a repeating pattern of spring segments2222and cutouts2224, like that of the clasp1200.

The barbed clasp2200also includes features similar to the clasp2000, such as a plurality of independent movable arms2230that each have a barbed portion2240having a single barb2244. The independent arms2230of the clasp2200individually pinch the tissue of the native leaflet which allows for improved engagement of tissue that is not uniform in thickness. The arms2230can also be shape set in a wide or spread out arrangement and crimped down into a narrow configuration for deployment so that the barbs2244can be spaced apart laterally more than would be possible if the arms were rigidly connected. The barbed portion2240of each arm2230includes a hole2242for receiving an actuation suture2252(FIG.65A).

The clasp2200is expandable between a collapsed condition and an expanded condition and is shape set in the expanded condition so that the clasp2200automatically expands from the collapsed condition to the expanded condition. As can be seen inFIG.65A, the clasp2200can be deployed from a delivery sheath2250in the collapsed condition and allowed to self-expand into the expanded condition. The expansion and contraction of the clasp2200is controlled by the actuation suture2252that cinches the independent arms2230together to collapse the clasp2200so that it fits within the delivery sheath2250. In some embodiments, the independent arms collapse together by merely retracting the clasp2100into the delivery sheath.

The fixed arm2210is formed from a tongue2211extending from the hinge portion2220to an end2214. The tongue2211includes holes2212for securing the tongue2211to the implantable device. In certain embodiments, the tongue2211is formed from a wide plate of material to provide a larger lateral area as a pinching location. In certain embodiments, the end2214of the tongue2211includes a T-shape cross-member like that of clasp2100.

The barbed clasp2200is laser cut from a layer2202of shape-memory alloy, such as Nitinol. Like the clasp2100shown inFIG.57A, the barbs2242lay flat in the same plane as the rest of the clasp2200when cut out of the layer2202of material. The moveable arms2230and barbed portions2240are then bent and twisted into the shape shown inFIGS.64-68and are then subjected to a shape setting process. In some embodiments, the barbs of the independent arms are [?] cut so that the barbs are bent upwards like the barbs of clasp1200, thereby not requiring the twisting of the independent arms. As noted above, the independent arms2230of the clasp2200can be shape set as wide or narrow as desired. In certain embodiments, individual arms2230may be longer or shorter than others, and the spacing of the arms2230may vary or be uniform.

Cutting the barbs2244out of the sheet of material and then twisting them into position also allows larger barbs of a variety of shapes to be formed. In certain embodiments, the barbed portions2240may include multiple smaller barbs arranged in series that may or may not be facing in the same direction. In certain embodiments, the ends of the barbs2244are further sharpened using any suitable sharpening means. In certain embodiments, the beams2231include twisted portions2232. The twisted portions2232may act as torsional springs that resist lateral forces applied to the ends of the barbs2244, thereby helping to maintain the alignment of the barbs2244when engaging the tissue of the native leaflets.

Referring now toFIGS.69-73B, various arrangements for attaching an actuating suture to exemplary barb clasps are shown. In these embodiments, an intermediate suture loop is made through one or more of the eyelets in the barbed clasp and the actuation suture is inserted through one or more of the intermediate loops. Connecting to the clasp through an intermediate loop of suture material reduces friction experienced by the actuation suture relative to the friction between the actuation suture and the clasp material. Both ends of the actuation suture extend back into and through the delivery sheath (not shown). The suture can be removed by pulling one end of the suture proximally until the other end of the suture pulls through the eyelet or intermediate loop and back into the delivery sheath.

Referring now toFIG.69, an exemplary suture arrangement2300is shown attached to the barb clasp400described above. The suture arrangement2300includes an intermediate suture loop2302inserted through the eyelet442and around the end of the barbed portion440. Alternatively, the intermediate suture loop2302may be inserted through the eyelet442and between the side beams of the moveable arm. An actuation suture2304is threaded from the delivery sheath through the intermediate suture loop2302and back into the delivery sheath. Tension applied to the actuation suture2304opens the clasp400when the spring forces keeping the clasp400closed are overcome. Releasing tension on the actuation suture2304allows the clasp400to spring shut. The rounded shape of the barbed portion440of the clasp400prohibits the clasp400from catching on native tissue or other portions of the implantable device.

Referring now toFIGS.70A-70B, an exemplary suture arrangement2400is shown attached to the barb clasp1200described above. The suture arrangement2400includes an intermediate suture loop2402inserted through the center eyelet1242and between the side beams1231of the moveable arm1230. An actuation suture2404is threaded from the delivery sheath through the intermediate suture loop2402and back into the delivery sheath. Tension applied to the actuation suture2404opens the clasp1200when the spring forces keeping the clasp1200closed are overcome. Releasing tension on the actuation suture2404allows the clasp1200to spring shut.

FIG.70Ais a side view of the suture arrangement2400showing that a gap or recess2406may form between the end of the clasp and the actuating suture2404of the suture arrangement2400described above. In particular, the gap2406may form when the actuation suture2404is at an angle with the barbed portion of the clasp1200.FIG.70Bis a front view of the suture arrangement2400showing that side gaps or recesses2408are formed between the actuation suture2404and the sides of the barbed portion1240of the clasp1200. Under certain conditions, the gaps or recesses2406,2408may become catch points—i.e., a location that has a potential to catch or snag native tissue or other portions of the implantable device during deployment and installation and/or on a catheter wall during retrieval. In particular, sharp angles and edges may become catch points. Rounding the corners of the clasp1200, as can be seen inFIG.70B, reduces the chance that the clasp1200will catch. In some embodiments, the device does not include any recesses having a depth greater than one third of the width of the device.

Referring now toFIG.71, a front view of an exemplary suture arrangement2500is shown attached to the barb clasp1200described above. The suture arrangement2500includes an intermediate suture loop2502inserted through the center eyelet1242and around the end of the barbed portion1240. An actuation suture2504is threaded from the delivery sheath through the intermediate suture loop2502and back into the delivery sheath. Tension applied to the actuation suture2504opens the clasp1200when the spring forces keeping the clasp1200closed are overcome. Releasing tension on the actuation suture2504allows the clasp1200to spring shut.

Forming the intermediate suture loop2502around the end of the barbed portion1240eliminates the possibility that a gap (e.g., the gap2406shown inFIG.70A) will form between the actuation suture and the clasp. Like the suture arrangement2400described above and shown inFIG.70B,FIG.71shows that side gaps2508are formed between the actuation suture2504and the sides of the barbed portion1240of the clasp1200. Under certain conditions, the gaps2508may become catch points—i.e., a location that has a potential to catch or snag native tissue or other portions of the implantable device during deployment and installation and/or on the catheter during retrieval. In particular, sharp angles and edges may become catch points. Rounding the corners of the clasp1200, as can be seen inFIG.71, reduces the chance that the clasp1200will catch on native tissue or other portions of the device.

Referring now toFIGS.72-73B, an exemplary suture arrangement2600is shown attached to the barb clasp1200described above. The suture arrangement2600includes intermediate suture loops2602inserted through the eyelets1242proximate the sides of the clasp1200and around the end of the barbed portion1240. An actuation suture2604is threaded from the delivery sheath through the intermediate suture loops2602and back into the delivery sheath. Tension applied to the actuation suture2604opens the clasp1200when the spring forces keeping the clasp1200closed are overcome. Releasing tension on the actuation suture2604allows the clasp1200to spring shut.

The suture arrangement2600reduces or eliminates the gaps shown inFIGS.70A-71that can become catch points. Forming the intermediate suture loops2602around the end of the barbed portion1240eliminates the possibility of a gap, such as the gap2406shown inFIG.70A, from forming between the clasp1200and the actuation suture2604. The suture arrangement2600also reduces or eliminates side gaps, such as the side gaps2508shown inFIGS.70B and71, between the actuation suture2604and the sides of the clasp1200.

Referring now toFIGS.74A-75, exemplary barb clasps and implantable devices are shown. As noted above, catch points are locations on the implantable device that have a potential to catch or snag native tissue, other portions of the implantable device, and/or delivery catheter during deployment and installation and/or during recapture or retrieval. In addition to catch points that may be formed on individual components of the implantable device, such as the catch points described above, catch points may also be formed by the assembly of two or more components.

Referring now toFIGS.74A-74B, an exemplary implantable device2700is shown assembled with two barb clasps400. The barb clasps400are attached to inner paddles2720of the implantable device2700that extend from a coaption element2710. A suture arrangement2730includes intermediate suture loops2732attached to the barbed portion440of the clasps400, and actuation sutures2734extending from a delivery sheath2702, through the intermediate suture loops2732, and back into the sheath2702. When the clasps400are in a closed condition, the offset of the hinge portions420forms a gap2740between the clasps400and coaption element2710that can become a catch point. As can be seen inFIG.74B, the gap2740is reduced or eliminated when the clasps400are opened partially, though the overall width of the device2700increases because of the opening of the clasps400. As such, the catch point can be eliminated during recapture or retrieval by partially opening the clasps400as shown inFIG.74B. Partially opening the clasps when retracting the device into the sheath has an additional benefit of causing the actuation lines or sutures to engage an opening2703of the delivery sheath2702, thereby causing the opening2703to flair open and provide a larger opening through which the device2700can be withdrawn. Suture configurations like those shown inFIGS.70B and71engage the opening2703in two locations as the sutures extend from the clasps in two locations, thereby widening the opening2703in a substantially diamond shape. Suture configurations like those shown inFIG.72engage the opening2703in four locations because the sutures extend from the clasps in four locations, thereby widening the opening2703in a substantially rectangular shape. The actuation sutures2734can be relaxed after the hinge portions420are in the catheter.

Referring now toFIG.75, an exemplary implantable device2800is shown assembled with two barb clasps1200. The barb clasps1200are attached to inner paddles2820of the implantable device2800that extend from a coaption element2810. A suture arrangement2830includes intermediate suture loops2832attached to the barbed portion1240of the clasps1200, and actuation sutures2834extending from a delivery sheath2802, through the intermediate suture loops2832, and back into the sheath2802. The round shape of the hinge portion1220of the clasp1200prevents a catch point from forming at an intersection2840between the hinge portion1220and the coaption element2810. Thus, the shape of the clasp1200reduces or eliminates gaps, such as the gap2740shown inFIG.74Bthat may become catch points, without needing to partially open the clasps1200during retrieval or recapture.

In certain embodiments, rather than an intermediate suture loop, the actuation line or suture is attached to a portion of a covering surrounding a clasp of an implantable device. For example, the actuation line or suture may be threaded through a loop or openings in the covering. The covering may be formed from a flexible material that may be a mesh, woven, braided, or formed in any other suitable way. The flexible material may be cloth, shape-memory alloy wire—such as Nitinol—to provide shape setting capability, or any other flexible material suitable for implantation in the human body.

Referring now toFIG.76, a side view of an exemplary barb clasp2900is shown. While the clasp2900is shown in the shape of the clasp1200described above, the clasp2900can have any shape suitable for use as a barbed clasp formed from laminated layers of material, such as any of the clasps described above. The clasp2900has a fixed arm2910, hinged portion2920, moveable arm2930, and barbed portion2940. The clasp2900is formed from a first layer2902and a second layer2904of material. The layers2902,2904may be formed from similar or different materials, and may have the same or different thicknesses. In certain embodiments, additional layers of material may also be provided.

Referring now toFIG.77, a side view of an exemplary double-ended barb clasp3000is shown. The double-ended clasp3000has a fixed arm3010with hinge portions3020and moveable arms3030extending from both ends. Each moveable arm3030includes a barbed portion3040including at least one barb3042. While the barbs3042are shown facing outwards, in other embodiments the barbs3042face inwards. The clasp3000is formed from first and second layers of material3002,3004, though, in certain embodiments, the clasp is formed from a single layer, and in certain other embodiments, is formed from more than two layers. The hinge portions3020, movable arms3030, and barbed portions3040may be formed in the shape of any of the clasps described above.

Referring now toFIGS.78-79, an exemplary barbed clasp3102for use in implantable prosthetic devices, such as devices100,200,300described above, is shown. The barbed clasp3102includes elements of clasp1200described above. The barbed clasp3102includes a fixed arm3110that is attached to the implantable device and a hinge portion3120that allows the clasp3102to open and close. The hinge portion3120is formed from a repeating pattern of spring segments3122and cutouts3124, like that of the clasp1200. The barbed clasp3102also includes a pair of independent first and second movable arms3130,3132extending from the hinge portion3120to a barbed portion3140having barbs3144.

The fixed arm3110is formed from a tongue3111extending from the hinge portion3120to an end3114. The tongue3111includes holes3112for securing the tongue3111to the implantable device. In certain embodiments, the tongue3111is formed from a wide plate of material to provide a larger lateral area as a pinching location. In certain embodiments, the end3114of the tongue3111includes a T-shape cross-member like that of clasp3102.

The moveable arms3130,3132of the clasp3102individually pinch the tissue of the native leaflet which allows for improved engagement of tissue that is not uniform in thickness. In some embodiments, the moveable arms3130,3132are formed from a single moveable arm similar to the moveable arm1230of clasp1200that is separated into first and second moveable arms3130,3132by a cut3148so that the first and second moveable arms3130,3132are allowed to open and close independent from each other. In some embodiments, the hinge portion3120is also separated into first and second hinge portions (not shown).

Referring now toFIG.79, an exemplary implantable device3100is shown assembled with two barb clasps3102. The barb clasps3102are attached to inner paddles3108of the implantable device3100that extend from a coaption element3106. An actuation arrangement3150includes intermediate suture loops3152attached to holes3146in the barbed portion3140of the first and second moveable arms3130,3132and first and second actuation sutures3154,3156. The first and second actuation sutures3154,3156extend from the delivery sheath3104, through the intermediate suture loops3152, and back into the delivery sheath3104. Each of the moveable arms3130,3132can be separately opened by applying tension to the first and second actuation sutures3154,3156, respectively. Opening the first and second moveable arms3130,3132separately allows the grip of the clasp3102on native tissue to be adjusted based on the thickness of the tissue and the orientation of the clasp3100.

Referring now toFIGS.80A-80E, an exemplary barbed clasp3200for use in implantable prosthetic devices, such as devices100,200,300described above, is shown. The clasp3200is configured to place a tensioning force on the native tissue when the implantable prosthetic device—e.g., any device described in the present application—is attached to the native tissue. Like the barbed clasps described above, the barbed clasp3200includes a fixed arm3210, a hinge portion3220, and a moveable arm3230having a barbed portion3240. The fixed arm3210of the clasp3200is slideably connected to a paddle3202of an implantable device such that the clasp3200can be moved along the paddle3202in the direction3204. For example, an actuation line3250can be used to move the clasp3200along the paddle3202in the direction3204. The actuation line3250can also be used move the moveable arm3230between the closed position (as shown inFIG.80A) and the open position (as shown inFIG.80B). The actuation line3250can take any form described in the present application. In some embodiments, the clasp3200includes an optional biasing member3260(e.g., a spring) configured to maintain the clasp3200in a desired position along the paddle3202(e.g., the position shown inFIGS.80A and80E).

Referring toFIG.80A, the clasp3200is shown in a first position on the paddle3202and in a closed position. Referring toFIG.80B, the clasp3200is shown after the moveable arm3230has been moved in a direction3203to an open position by the actuation line3250. Referring toFIG.80C, the clasp3200is shown after having been moved along the paddle3202in a direction3205to a second position. In some embodiments, the clasp3200is moved along the paddle3202in the direction3205by the actuation line3250or a separate mechanism. In embodiments that include the biasing member3260, enough force is applied to the clasp3200to move the clasp3200in the direction3205, causing the biasing member3260to expand and create a tension force on the clasp3200in a direction3206opposite to the direction3205. While the illustrated embodiment shows the clasp3200being moved to an open position (as shown inFIG.80B) prior to the clasp3200being moved along the paddle3202in the direction3205to the second position (as shown inFIG.80C), it should be understood that clasp3200can be moved in the direction3205to the second position prior to the moveable arm3230of the clasp3200being moved in the direction3203to an open position or the movements can be simultaneous. Referring toFIG.80D, the moveable arm3230is moved to a closed position in the direction3207by the actuation line3250to secure the barbed portion3240of the clasp3200to valve tissue (not shown). In the position shown inFIG.80D, the biasing member3260is being maintained in an extended position (e.g., as a result of the force applied to the clasp3200by the actuation line3250, or another mechanism, to keep the clasp3200in the second position), which means the biasing member3260is placing a tensioning force on the clasp3200in the direction3206. Referring toFIG.80E, after the barbed portion3240of the clasp3200is secured to the native tissue, the force maintaining the clasp3200in the second position is released, which causes the tensioning force applied by the biasing member3260to move the clasp3200along the paddle3202in the direction3208. The movement of the clasp3200in the direction3208causes the barbed portion3240to create a tensioning force on the native tissue in the direction3209. This tensioning force on the native tissue allows the implantable device to maintain a secure connection to the native tissue.

Referring now toFIGS.81A-81C, an exemplary barbed clasp3300for use in implantable prosthetic devices, such as devices100,200,300described above, is shown. The clasp3300is configured to place a tensioning force on the native tissue when the implantable prosthetic device—e.g., any device described in the present application—is attached to the native tissue. Like the barbed clasps described above, the barbed clasp3300includes a fixed arm3310, a hinge portion3320, and a moveable arm3330having a barbed portion3340. The moveable arm3330includes a flexible portion3332arranged between the hinge portion3320and the barbed portion3340. The flexible portion3332may comprise, for example, a cutout in the moveable arm3330, a different material than the remainder of the moveable arm3330, or can take any other suitable form that allows the flexible portion3332to be more flexible than the remainder of the moveable arm3330. In some embodiments, the flexible portion3332is omitted and an actuation mechanism3350is still capable of flexing the barbed portion3340of the moveable arm3330as illustrated byFIGS.81A-81C.

The actuation mechanism3350includes an actuation line3352(e.g., a suture) and a push-pull link3354configured to receive the line3352. The push-pull link3354can be a catheter, a wire with a loop (as shown inFIG.82), or any other link that is capable of receiving the line3352and pushing or pulling the moveable arm3330of the clasp3300. The actuation line3352extends at a first end3351from a delivery sheath (not shown) and is removably attached to the moveable arm3330at a first connection point3356arranged proximate the barbed portion3340. The actuation line3352also extends from the first connection point3356and is removably attached to the moveable arm3330at a second connection point3358arranged between the flexible portion3332and the hinge portion3320. The actuation line3352then extends from the second connection point3358and through the push-pull link3354at a second end3353.

Referring toFIG.81A, the clasp3300is shown in an open position with native tissue3302disposed in an opening3304between the moveable arm3330and the fixed arm3310. The clasp3300can be moved to the open position by pulling on the line3352. Referring toFIG.81B, the link3354and the line3352of the actuation mechanism3350is used to move the moveable arm3330in the closing direction3306to the closed position and flex the barbed portion3340in the opening direction3308. In doing so, the first end3351of the line3352is pulled in the opening direction3308while the link3354is pushed in the closing direction3306such that the barbed portion3340of the moveable arm3330pivots or flexes at the flexible portion3332in the upward direction3303as it opens. Still referring toFIG.81B, the link3354and the line3352are moved such that the barbed portion3340engages or pierces the native tissue3302as the moveable arm3330is moved into the closed position and the barbed portion3340is in the flexed position.

Referring now toFIG.81C, the first end3351of the line3352is released, allowing the barbed portion3340of the moveable arm3330to pivot about the flexible portion3332. As the barbed portion3340pivots, the native tissue3302is retracted in the downward or inward direction3305, thereby creating a tensioning force on the native tissue in the inward direction3305. After the moveable arm3330is secured to the native tissue3302(as shown inFIG.81C) the link3354and the line3352are removed from the clasp3300.

Referring now toFIG.82, an actuation mechanism3400for use in implantable prosthetic devices, such as devices100,200,300described above, is shown. The mechanism3400includes first and second control members3410,3420that extend from a delivery device3402. The delivery device3402may be any suitable device, such as a sheath or catheter. The first and second control members3410,3420include first and second sutures3412,3422and first and second flexible wires3414,3424. The first and second flexible wires3414,3424extend from the delivery device3402and each include a loop3416,3426for receiving the first and second sutures3412,3422and for engaging a clasp (e.g., clasp1200described above). Each of the first and second sutures3412,3422extends from the delivery device3402, through a one of the first and second loops3416,3426, respectively, and back into the delivery device3402. In some embodiments, the first and second control members3412,3422extend through separate delivery devices3402. The sutures3412,3422are removably attached to moveable arms of exemplary barbed clasps described above. The first and second loops3416,3426of the respective wires3414,3424are able to move along the corresponding sutures3412,3422such that the loops3416,3426can engage the corresponding barbed clasps to engage the moveable arms. That is, the sutures3412,3422are used to pull the moveable arms in an opening direction and the wires3414,3424are used to push the moveable arms in a closing direction. The wires3414,3424can be made of, for example, steel alloy, nickel-titanium alloy, or any other metal or plastic material. In certain embodiments, the wires3414,3424can have a diameter between about 0.10 mm and about 0.35 mm, between about 0.15 mm and about 0.30 mm, and between about 0.20 mm and about 0.25 mm.

While various inventive aspects, concepts and features of the disclosures may be described and illustrated herein as embodied in combination in the exemplary embodiments, these various aspects, concepts, and features may be used in many alternative embodiments, either individually or in various combinations and sub-combinations thereof. Unless expressly excluded herein all such combinations and sub-combinations are intended to be within the scope of the present application. Still further, while various alternative embodiments as to the various aspects, concepts, and features of the disclosures—such as alternative materials, structures, configurations, methods, devices, and components, alternatives as to form, fit, and function, and so on—may be described herein, such descriptions are not intended to be a complete or exhaustive list of available alternative embodiments, whether presently known or later developed. Those skilled in the art may readily adopt one or more of the inventive aspects, concepts, or features into additional embodiments and uses within the scope of the present application even if such embodiments are not expressly disclosed herein.

Additionally, even though some features, concepts, or aspects of the disclosures may be described herein as being a preferred arrangement or method, such description is not intended to suggest that such feature is required or necessary unless expressly so stated. Still further, exemplary or representative values and ranges may be included to assist in understanding the present application, however, such values and ranges are not to be construed in a limiting sense and are intended to be critical values or ranges only if so expressly stated.

Moreover, while various aspects, features and concepts may be expressly identified herein as being inventive or forming part of a disclosure, such identification is not intended to be exclusive, but rather there may be inventive aspects, concepts, and features that are fully described herein without being expressly identified as such or as part of a specific disclosure, the disclosures instead being set forth in the appended claims. Descriptions of exemplary methods or processes are not limited to inclusion of all steps as being required in all cases, nor is the order that the steps are presented to be construed as required or necessary unless expressly so stated. The words used in the claims have their full ordinary meanings and are not limited in any way by the description of the embodiments in the specification.