Patent ID: 12208008

DETAILED DESCRIPTION

The present disclosure provides methods and devices for grasping and securing tissues such as valve leaflets to treat cardiac valve regurgitation. In one embodiment, a valve fixation device may comprise a unitary elongate member comprising at least one neck portion and at least one arm portion, the elongate member being biased towards a closed configuration wherein at least a pair of tissue engaging surfaces of the elongate member (for example, a tissue engaging surface on the neck portion and a tissue engaging surface of the arm portion) are held adjacent to each other by a bias force. The bias force is at least equal to a valve leaflet grasping force, enabling the fixation device to grasp and retain leaflets as part of cardiac treatment. A delivery tool including a spreader may independently translate the tissue engaging surfaces to enable cardiac leaflets to be captured and retained by and/or between the tissue engaging surfaces. The valve fixation device may include at least two arms, each of which may be independently controlled to grasp and capture opposing leaflets of a valve, such as the anterior and posterior leaflets of a mitral valve, to reduce the size of the valve opening and improve cardiac performance. In some embodiments, at least a portion of the fixation device includes one or more tissue retention mechanisms, including but not limited to teeth, barbs, hooks, tines, pores, or surface texture, etc., that improves fixation device retention. In some embodiments, the delivery tool may include one or more features, such as a shield or a standoff, configured to reduce interaction between tissue retention mechanisms and tissue during positioning of the fixation device.

These and other beneficial aspects of an implant and method of deployment are described in more detail below. Although embodiments of the present disclosure may be described with specific reference to mitral valves, the principles disclosed herein may be readily adapted to facilitate reconstruction of any valve annulus, for example including a tricuspid valve annulus and/or may similarly benefit any other dilatation, valve incompetency, valve leakage and other similar heart failure conditions.

As used herein, the term “distal” refers to the end farthest away from the medical professional when introducing a medical device into a patient, while the term “proximal” refers to the end closest to the medical professional when introducing a medical device into a patient.

FIGS.1A-1Dillustrate perspective views of one embodiment of a fixation device100that may be used as disclosed herein to reduce the size of a valve, for example by joining together valve leaflets. The fixation device100is shown formed of a unitary, elongate body105having a proximal neck portion110and a distal portion130comprising one or more arms of the elongate body. In various embodiments, the body105may be manufactured from a shape memory alloy (SMA) or similar materials with the ability to recover a pre-defined configuration. Such materials include, but are not limited to, Nickel Titanium, Graphene, Nitinol, copper-aluminum-nickel and the like.

Such materials are referred to herein as biased towards the pre-defined configuration. A bias force is the recovery force of the shaped memory alloy, e.g., the force exhibited by the body to recover (e.g. return to its pre-defined configuration) under the strain of deformation from the pre-defined configuration. The bias force is a function of the size, shape, and composition of shaped material. In one example embodiment, the overall elongate body may have a length of 14 mm-24 mm, to provide a “folded” length between 7 mm and 12 mm, a width of 2 mm-6 mm and a thickness of 0.25-0.75 mm, providing a device having a grasping force of between 0.1 and 0.5 lbs. Although a fixation device having ranges of length, width, and/or thickness is disclosed, it is appreciated that one of skill in the art may develop similar fixation devices capable of providing similar bias or grasping forces that urge the fixation device towards a closed, tissue retaining configuration, and such similar devices are considered to be within the scope of this disclosure.

According to one aspect, the fixation device may be manufactured to provide sufficient grasping force to enable it to fixedly attach to leaflet tissue without imparting undue gravitational forces that may disrupt remaining valve function. In this way, the fixation device has a mass that is not significantly larger than necessary such that the weight of the fixation device does not negatively impact the leaflet or nearby tissue. For example, a device100may weigh between 50-150 mg, for example 65 mg, or the like, e.g., such that a weight of a clamp may not undesirably interfere with leaflet operation.

FIG.1Aillustrates the unitary elongate body105in an unbiased state. In one embodiment, the unitary elongate body105has a length L that extends longitudinally along an axis A, a width W, perpendicular to the Axis A, and a thickness T. In some embodiments, such as that shown inFIG.1A, the width is fixed along the length L. In other embodiments, the width may vary (increase, decrease) along the length L. Similarly, although the thickness T is shown to be relatively uniform along the length and width, it is appreciated that in various embodiments the thickness may vary (increase, decrease) along the length L or across the width W. In the embodiment ofFIG.1A, as will be described in more detail below, the distal portion130of the unitary elongate body105is shown apportioned across its width into a plurality of arms, such as arm120and arm122.

The unitary elongate body has several surfaces, including a forward surface112, shown inFIG.1A, and a rear surface111(shown inFIG.1C). At least a portion of the proximal neck portion110of the unitary elongate body105includes a tissue engaging portion115, and at least a portion of a distal end of an arm, such as arm120, also includes a tissue engaging surface portion125. Although certain portions of the body105are designated as tissue engaging surfaces, it is appreciated that the tissue engaging surface portion may include a larger or smaller area than that designated, and that the tissue engaging portion may be any surface of the body105that contacts leaflet tissue during use.

According to one embodiment, the pre-defined configuration of the unitary elongate body comprises a closed configuration wherein common surfaces of proximal and distal portions of the unitary elongate body are positioned close to and opposing each other to form a leaflet fixation device.

For example,FIG.1Billustrates the unitary elongate body100in its biased, closed, configuration. Each arm,120,122is differently biased, formed such that distal ends121,123of the respective arms120,122contact different surfaces (e.g.,111,112) of the proximal neck portion110of the leaflet fixation device100. For example, distal end121of arm120contacts the proximal neck portion110of the device100at a tissue engagement surface115, while the distal end123of arm122contacts the proximal neck portion110of the device100on the opposing surface. As a result, the fixation device100leverages the resistive forces of shape memory materials to provide a unitary, low profile, light weight retention mechanism for valve leaflet treatment.

FIG.1Cillustrates the rearward facing surface111of the fixation device100comprising biased arms120,122and shown including tissue engaging surface117on its proximal end110. The embodiment of the fixation device100ofFIGS.1A-1Dcomprises a two-armed retention device, wherein each of the arms are biased towards an opposing surface of the proximal neck portion of the body105. Thus, a distal tissue engaging surface127of arm122, in a biased configuration, contacts or is otherwise close to and facing a tissue engaging surface117. InFIG.1C, the arm122is shown pulled away from the proximal neck portion110of body105by an angular extent133. The angular extent133corresponds to an open configuration of the arm122, that leaving a gap between the body105and the arm122that is sufficiently wide to enable leaflet tissue to be disposed therebetween. In some embodiments, the angular extent133may range between 75 and 120 degrees or more, for example, to leave a gap in the range of 90 degrees.

FIG.1Dis a diagram illustrating the fixation device100in a fully open configuration, with both arms120,122spaced apart from the proximal neck portion110such that the distal tissue engaging surfaces125,127are spaced apart from the proximal tissue engaging surfaces117. As described in more detail below, according to one aspect, each of the arms120,122of the fixation device100may be independently opened and closed, enabling greater precision and accuracy when grabbing tissue by enabling grasping of individual leaflets during the procedure.

In the embodiment ofFIGS.1A-1D, where the arms of the distal portion of the unitary elongate body are formed by apportioning the width of the distal portion into segments, the distal tissue engaging surface (125,127) comprises only approximately half (or other portion, when arms have different widths) of the width W of the unitary body105. In such a configuration, the grasping force of each arm should be selected to compensate for the reduced size of the tissue engaging surface.

FIGS.2A-2Dillustrate various views of a second embodiment of a fixation device200comprising a unitary elongate body205having a length L, a width W, and a thickness T which may correspond generally in L and W dimension to the device100ofFIGS.1A-1D, and may range in thickness T from the same dimension to double the thickness or more at least partially along its length, as will be described. InFIG.2A, the unitary elongate body205is shown in an unbiased configuration. The body205includes a proximal neck portion210and a distal portion230, the proximal neck portion210comprising a tissue engaging surface215and the distal portion230comprising a tissue engaging surface225. In some embodiments, the thickness of the distal portion230may be greater than the thickness of the proximal neck portion210, although the disclosure is not so limited. Arms220,222of the fixation device200may be formed by apportioning the thickness T of the distal portion into segments. With such an arrangement, the tissue engaging surface area225of the distal end230of the fixation device200utilizes the entire width W of the body205, enabling a more comprehensive use of the proximal tissue engaging portion215for securing tissue. In some embodiments, increasing the tissue engaging surface area in this manner may enable lighter weight materials to be used for a fixation device capable of achieving the desired bias force for leaflet grasping.

FIG.2Bis a side view of the fixation device200. The distal portion230of the device200is shown bisected along its thickness T, forming two arms220,222which are biased towards a closed configuration wherein the distal ends of arms220,222contact, or are otherwise close to and facing opposing surfaces of the proximal neck portion210of the device200.

FIG.2Cillustrates the device200in a partially open configuration, wherein the arm220has been pulled or pushed back from the biased, closed configuration to expose distal tissue engaging surface227and proximal tissue engaging surface217(not visible) to leaflet tissue.

FIG.2Dillustrates the device200in a fully open configuration, wherein both arms220,222have been pushed or pulled away from their biased, closed configuration to an open configuration wherein gaps G1, G2enable leaflet tissue to be disposed between tissue engaging surfaces of the device200for capture.

FIGS.3A-3Cillustrate an alternate embodiment of a fixation device300. Like the device200ofFIGS.2A-2C, the device ofFIGS.3A-3Cincludes arms320,322formed by bisecting the distal portion of the elongate body305along its thickness. The arms320,322are biased towards a closed configuration, wherein distal portions of the arms320,322contact, or are close to and facing the proximal neck portion310of the body305. In the embodiment ofFIGS.3A,3C, the proximal neck portion310of the body305includes one or more tissue retention features, such as tissue retention feature323. InFIGS.3A-3C, the tissue retention features323are shown disposed upon opposing surfaces311,312the proximal neck portion310of the elongate body305. The illustrated tissue retention features323comprise a tooth that extends at an angle from a longitudinal axis A of the elongate body. In one embodiment, the tooth is distally angled, to secure leaflet tissue, when disposed between the arms320,322and the proximal tissue engaging surfaces, against pullout due to chronic palpatory forces.

In some embodiments, the one or more tissue retention mechanisms may be arranged in columns extending along at least one of the plurality of arms such that the plurality of retention mechanisms are in different planes. The protrusions may extend not more than 50% through a thickness of a wall of the leaflet, e.g., the protrusions may not extend into the wall of a leaflet and may instead distort the tissue. The protrusions may extend a distance from an arm that may be about 0.5 millimeters to about 1.5 millimeters.

FIG.3Bis a cross-sectional view of device300, illustrating tissue retention mechanisms323deployed on opposing surfaces311,312of the proximal end310of the device300. As shown inFIG.3B, as the arms320,322are urged towards their biased configuration, the arms will push any captured tissue towards the tissue retention mechanisms323, improving the affixation of the device300to leaflet tissue.FIG.3Cillustrates the device300in a fully open configuration, providing gaps G1, G2between the proximal end310of the device300and respective arms320,322. It is appreciated that, when employing tissue retention mechanisms such as teeth323, the resiliency of the unitary elongate body may be selected to ensure that the gaps G1, G2are wide enough to accommodate leaflet tissue without interference from the retention mechanisms323. In other words, the open configuration should provide a gap at least equal to expected leaflet tissue thickness plus the protrusion extent of any tissue retention mechanism used to retain the leaflet.

AlthoughFIGS.3A-3Cillustrate tissue retention mechanisms relatively equally disposed on opposing surfaces of the proximal neck portion310of the body305, it is appreciated that tissue retention mechanisms may take many forms and may be deployed in various patterns which are optimized to the particular tissue to be captured by the fixation device, as well as to secure the device against chronic palpatory forces that act upon it. Thus, although a particularly shaped tooth is shown inFIGS.3A-3C, the present disclosure is not limited to the use of teeth, but additionally encompasses barbs, hooks, tines, or another feature that may be used to engage or interact with leaflet tissue.

FIGS.4-7illustrate various embodiments of tissue retention devices that employ different tissue retention mechanisms.FIG.4is a cross section view of one embodiment of a device400that includes a plurality of tissue retention mechanisms disposed on the proximal neck portion401of the device400, including distally facing teeth402and proximally facing teeth404. Such embodiments may improve the ability of tissue to be grasped between the proximally and distally facing teeth, to assist in retaining leaflet tissue by the device400.

FIG.5is a cross section view of an embodiment of a device500that includes a plurality of tissue retention mechanisms, wherein some tissue retention mechanisms, such as neck teeth512, are disposed on the proximal neck portion501of the device500, and other tissue retention mechanisms, such as tissue engaging teeth515, are disposed on the arms514,516. With such an arrangement, tissue retention is applied to both sides of a captured leaflet, further increasing the strength of affixation of the device500to the leaflet.

FIG.6is a cross section view of an embodiment of a device600that includes a plurality of tissue retention mechanisms, wherein some tissue retention mechanisms, such as neck teeth622,624, are disposed on the proximal neck portion601of the device600, and other tissue retention mechanisms, such as tissue engaging teeth625, are disposed on the arms626,628. The embodiment ofFIG.6illustrates how the pattern of tissue retention mechanisms may vary in accordance with the particular tissue or chronic use conditions of the clip.

FIG.7is a side view perspective of an embodiment of a device700that includes a plurality of tissue retention mechanisms, including both tissue retention mechanisms that are configured to pierce tissue, such as neck teeth702,703on proximal neck portion701, and tissue engaging teeth705on arms704,706, as well as tissue retention mechanisms such as pores707which are configured to encourage endothelialization (e.g., tissue ingrowth) into the device700. For example, the pore size may range from between 5 and 30 μm. The pores may be distributed over portion or all of the elongate body. Other methods of promoting tissue ingrowth along a portion of or the entire elongate body, for example by modifying the surface texture of the elongate body, coating the body with pro-angiogenic drugs, etc., are also within the scope of this disclosure.

FIGS.8-10illustrate alternate embodiments of tissue fixation devices which may be formed from a resilient material that leverages the bias forces of a closed configuration to provide leaflet grasping forces for retaining the leaflet within the device.

FIG.8illustrates a fixation device800comprising an elongate body805formed into two opposing arms820,822, and bent so that the proximal end810of the elongate body faces the distal end830of the elongate body, and portions821,823of the arms are biased to a closed configuration such that tissue engaging surfaces811,813of the arms are adjacent to and face each other to enable tissue to be grasped between the arms820,822. Each arm820,822is shown to include tissue retention mechanisms such as teeth802disposed in parallel columns along surfaces811,813of the device800. In the embodiment ofFIG.8, the proximal end810and distal end830of the elongate body805may each include a coupler832,833, that may be used, for example, to couple the device800to a delivery tool to manage delivery of the device800to the valve leaflet. As described in more detail below, in one embodiment, the coupler832may include a bore (not shown), having a central lumen835extending therethrough configured to accept a pin or other mechanism to releasably secure the arm to a delivery tool which is configured to move each arm820,822independently from other arms of the body805.

FIG.9is a side view of an embodiment of a fixation device900formed from a unitary elongate body905which has been apportioned along its thickness to form both proximal arms910,912in the proximal neck portion of the elongate body905as well as distal arms920,922in the distal portion of elongate body905. In one embodiment, distal arm920includes a biased configuration wherein a distal tissue engaging surface925is adjacent to, and faces, a proximal tissue engaging surface915of the proximal arm910. Distal arm922also includes a biased configuration wherein a distal tissue engaging surface927is adjacent to, and faces, a proximal tissue engaging surface917of the proximal arm910. Such a fixation device may serve to dampen the strain upon the leaflets by allowing the fixation portions to move more freely with the valve during use, while providing force necessary to retain the leaflets in a joined configuration to treat disease. In the embodiment ofFIG.9, each proximal arm910,912is shown to include tissue retention mechanisms, such as teeth924, disposed along its length. As discussed with regard toFIGS.4-7, additional or alternate tissue retention mechanisms and patterns may be substituted herein consistent with this disclosure.

FIG.10is a side view of an embodiment of a fixation device1000formed from a unitary elongate body1005which has been apportioned along its thickness to provide a plurality of distal arms1020,1022,1030,1032, each of which is biased to a closed configuration wherein at distal tissue engaging surfaces1021,1023,1031,1033are oriented towards a tissue engaging surface of the proximal neck portion1010of the body1050. In one embodiment, connectors1021,1023may be deployed to couple interior distal arms1030,1032to exterior distal arms1020,1022so that, when the exterior distal arms1020,1022are spread, the interior distal arms1030,1032are pulled open, allowing tissue to be disposed between the arms1020,1030,1022,1032an the proximal neck portion1010of the body1050. As shown inFIG.10, tissue retention mechanisms such as teeth1011,1013may be strategically placed along the proximal neck portion1010and/or arms1020,1022,1030,1032to secure tissue within the device1000.

The leaflet retaining devices such as those described in various embodiments above, may be used in a variety of therapeutic procedures, including endovascular, minimally-invasive, and open surgical procedures, and can be used in various anatomical regions, including the abdomen, thorax, cardiovascular system, heart, intestinal tract, stomach, urinary tract, bladder, lung, and other organs, vessels, and tissues. The fixation devices may be particularly useful for procedures requiring minimally-invasive or endovascular access to remote tissue locations, where the instruments utilized must negotiate long, narrow, and tortuous pathways to the treatment site.

For example, the leaflet fixation device may be used for edge to edge repair of a cardiac valve including but not limited to a mitral valve. The mitral valve can be accessed from a remote surgical or vascular access point and the two valve leaflets may be brought together at a fixation point using the fixation device via endovascular or minimally invasive approaches. For example, the fixation device may be used to join the anterior leaflet and posterior leaflet of the mitral valve at any location of the leaflets between the anterolateral and posteromedial commissures of the valve. Multiple fixation devices may be used to couple the leaflets at various points of the valve. In some circumstances the fixation device may be used in open surgical approaches as well. According to the invention, the mitral valve may be approached either from the atrial side (antegrade approach) or the ventricular side (retrograde approach), and either through blood vessels or through the heart wall.

The fixation device may be delivered using a tool that is positioned near a desired treatment site and used to manipulate the fixation device, enabling the device to grasp the target tissue. In endovascular applications, the delivery tool may typically be a working catheter that is translated to the treatment site via a delivery catheter/guidewire system. In surgical applications, the delivery tool may typically a surgical instrument.

In one embodiment, the method includes the steps of advancing the delivery tool having a proximal end and a distal end to a location within a patient's body, wherein the delivery tool releasably carries the fixation device and is configured to translate the fixation device between its open and closed configuration to grasp leaflet tissue, and to release the leaflet tissue following positioning of the fixation device on the leaflets.

FIGS.11A-11Eillustrate features of one embodiment of a delivery tool1100which may be used to deliver a fixation device1150to a treatment site. The delivery tool1100is shown to include a support arm1120comprising a proximal end1101and distal end1103, the distal end1103having an opening defining a sleeve configured to releasably accept the proximal neck portion1110of the fixation device1150. In some embodiments, for example, the proximal neck portion1110of the fixation device may include a slot which cooperates with a tab (not shown) internal to the sleeve to retain the proximal neck portion1110of the device within the sleeve during deployment. Following deployment, the tab may be withdrawn from the slot, freeing the device from the delivery tool.

The delivery tool1100further includes one or more spreader mechanisms, such as jaws1152,1154. Each jaw1152,1154is generally matched in shape to the curve of the fixation device1150to minimize the profile of the delivery tool. In one embodiment, the jaws1152,1154comprise a curved shape to minimize the potential for interference between the distal end1103of the delivery tool and cardiac features, such as chordae tendinea and the like. In one embodiment, each jaw1152,1154is pivotably mounted at pivot point1156of its distal end to the distal end1103of the support arm1120of the delivery tool1100. Guide cables1122,1124may extend from the proximal end of the jaw to the distal end1103of the support arm1120of the delivery tool1100, wherein actuation of the drive cables, for example, for example, pulling the cables proximally through the sleeve, may pull the jaws1152,1154away from a longitudinal axis defined by the delivery tool. In one embodiment, the distal arms of the fixation device1150are releasably coupled to the proximal ends of the jaws1152,1154such that when the jaw is pulled away from the longitudinal axis of the delivery tool, the distal arm is also pulled away, creating a gap which may be used to grasp leaflet tissue.

For example,FIG.11Billustrates the delivery tool1100supporting the fixation device1150in a partially open configuration, wherein the jaw1154is releasably coupled at its proximal end1157to the distal arm1155of the fixation device1150. Guide cable1124may be pulled into the support arm1120to open the jaw1154to create a gap G1for accepting leaflet tissue. The guide cable1124may then be released or otherwise actuated to allow the arm1155to return to its biased, closed configuration to capture leaflet tissue between the arm1155and the proximal neck portion1110of the fixation device1150.

FIG.11Cillustrates the actuation of the second jaw1152, for example which may occur by manipulation of the guide cable1122through the support arm1120as described above. When the guide cable1122is pulled proximally through the support arm1120, the jaw1152opens. The distal arm1159, which is releasably coupled to the jaw1152, also is pulled away from the proximal neck portion1110of the fixation device1150by action of the jaw, generating a gap G2for capturing a second valve leaflet. Once the valve leaflet is positioned within the gap G2, the guide cable1122may be released or otherwise controlled to allow the distal arm1159to return to its biased configuration, capturing tissue between the arm1159and the proximal neck portion1110of the device1150.

FIG.11Dis a close-up cross section of an example of a system for coupling the distal arm1159to the jaw1152. In one embodiment, as described above, the distal arm may have a coupler1162disposed at its distal end. The coupler may comprise, for example, a protuberance having a bore1163extending therethrough, with the bore sized to accept a distal end of the guide cable1122. In some embodiments, the guide cable1122may include a drive tube having a threaded coupler1134disposed on its distal end1125. The threads of the coupler may interact with threads or other features on the internal surface of the bore1163to secure the threaded coupler1134within the bore1163. In some embodiments, the drive tube may be rotatable, and rotation of the drive tube may translate the drive tube axially within the bore1163. Once the fixation device has been manipulated to grasp both anterior and posterior leaflets, actuation of the drive to may be performed to distally translate the drive tube out through bore1163, releasing the coupling between the arm1159of the fixation device and jaw1152of the delivery tool, and enabling removal of the delivery tool from the treatment site.

In some embodiments, the connection between the delivery tool and the fixation device may be formed to inhibit affixation of the fixation device during its placement, to facilitating positioning of the fixation device on the leaflets without tissue interference. For example,FIG.11Eis a close up view of one embodiment of a jaw1152of a delivery tool, including a sleeve1170disposed longitudinally along at least a portion of the length of the jaw. The sleeve1170, in one embodiment, provides a standoff which maintains a space between the tissue retention mechanisms and an opposing tissue engagement surface, to inhibit entry of the tissue retention mechanisms into tissue during positioning of the fixation device. A height HSTANDOFFof the sleeve1170may generally correspond to the protrusion distance of any tissue retention mechanism of a fixation device.

FIG.11F, for example, illustrates a fixation device1180disposed upon the jaw portion1152of a delivery system. The fixation device1180is shown to include tissue retention features (e.g., teeth)1183disposed along edges of the device1180and oriented and protruding towards a tissue engaging surface1185of the fixation device1180. The sleeve1170is configured to at least partially inhibit entry of the teeth1183. For example, the sleeve may have a height that is equal to at least half of the extent of protrusion of the teeth1183. In some embodiments, the sleeve1170may include a bore1187extending therethrough, for example, to slidably accept a cable (not shown) that opens and closes the jaw of the delivery tool. It should be noted that, although a unitary sleeve is shown inFIGS.11E and11F, alternative methods of inhibiting tissue affixation during placement of the fixation device, including but not limited to separate spacers disposed along the length of the jaw, shields disposed over the tissue retention mechanisms and the like are considered to be within the scope of this disclosure.

FIGS.12A-12Cillustrate an alternate embodiment of a delivery tool1200that may be used to deliver a fixation device1250such as those described herein in various embodiments, to a treatment site. The delivery tool includes a proximal end1201and a distal end1203, and a pair of spreader arms1230,1232rotatably disposed on the distal end1203of the delivery tool, wherein the spreader arms are operable to push the distal arms1220,1222of the fixation device1250away from a longitudinal axis defined by the delivery tool to thereby generate a gap between the tool1200and the arms1220,1222for corralling leaflet tissue. In some embodiments, the delivery tool may include a distal sleeve, configured to releasably carry the proximal neck portion1201of the fixation device to the treatment site. In various embodiments, each spreader arm may be rotatably coupled to the proximal end1201of the delivery tool, for example at pivot points1211,1213, and adapted to move smoothly over an internal surface1241,1243of the arms1220,1222. For example, in one embodiment, each spreader arm1230,1232may include a roller1240,1242disposed on its distal end that enables the spreader arm to smoothly glide over the surfaces1241,1243while providing a pushing force that acts against the biased configuration of the arms to generate the gap. It can be appreciated that the length of each spreader arm may vary depending upon the particular architecture of the fixation device but should be sufficient to allow the spreader arm to generate a gap that is capable of accepting leaflet tissue when rotated about its pivot point.

For example, referring now toFIG.12B, the delivery device is shown in a partially open position, wherein the spreader arm1232has been rotated across the surface1241of the distal arm1222to a position generally perpendicular to the axis of the delivery device. The rotation force of the spreader arm is sufficient to counteract the bias forces of the fixation device1250, causing the distal arm1222to be pushed away from the delivery tool1200and generating a gap G1between the tool1200and the distal arm1222for accepting tissue. When tissue has been corralled between the tool1200and the distal arm1222, the spreader arm1232may be rotated distally, removing the counteracting forces and allowing the distal arm1222to return to its biased configuration to capture tissue between the tool1200and the distal arm1222.

FIG.12Cillustrates the delivery device in a partially open position, wherein the spreader arm1230has been rotated across the surface1243of the distal arm1220to a position generally perpendicular to the axis of the delivery tool1200. The rotation force of the spreader arm1230is sufficient to counteract the bias forces of the fixation device1250, causing the distal arm1220to be pushed away from the delivery tool1200and generating a gap G2between the tool1200and the distal arm1220for accepting tissue. When tissue has been corralled between the tool1200and the distal arm1220, the spreader arm1230may be rotated distally, removing the counteracting forces and allowing the distal arm1220to return to its biased configuration to capture tissue between the tool1200and the distal arm1220.

Once both leaflets are secured, the delivery tool may be removed, for example by releasing or otherwise expelling the proximal end of the fixation device1250from the delivery tool1200.

FIGS.13A-13Dillustrate various structures of a heart1300, including a mitral valve1320comprising posterior and anterior leaflets1322,1324supported by chordae tendinea1325which are controlled by papillary muscles1326. In the illustrated embodiment, a delivery catheter1400supports a delivery tool1450and may be used to navigate the delivery tool1450to a treatment site, for example below a mitral annulus1340.

InFIG.13A, the delivery tool1450is shown delivered through the atrium to the leaflets, although the disclosure is not limited to any particular delivery pathway. The rounded architecture of the delivery tool1450reduces the potential of interference between the chordae tendinea and the delivery tool.FIG.13Billustrates the delivery tool1450following capture of a leaflet1324by the fixation device. Once one leaflet is captured, as shown inFIG.13Cthe delivery tool1450may be used to pull leaflets1324towards leaflet1322, for example, until the two leaflets coapt. The delivery tool1450may then be operated to open and close the spreader mechanism to capture the second leaflet1322within the retention device.

FIG.13Dis a magnified side view of the coupled leaflets shown inFIG.13C, following removal of the delivery tool. As shown inFIG.13D, following delivery, the fixation device1350is positioned such that the leaflets1322,1324are securely captured between the proximal end1310of the fixation device1350and the arms1352,1354of the fixation device1350.FIG.14is a top down view of a mitral valve, following placement of a fixation device1450between a posterior leaflet1402and an anterior leaflet1404.

Accordingly, a unitary, lightweight leaflet clip is provided for use in securing valve leaflets for cardia repair procedures has been shown and described in various embodiments. With such an arrangement, the number and type of components involved in the leaflet clipping solution is reduced to a single, unitary component that leverages the resistive forces of shape memory material as a fixation mechanism, thereby reducing the overall weight of the fixation device and failure risks associated with chronic interaction between components.

As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises” and/or “comprising,” or “includes” and/or “including” when used herein, specify the presence of stated features, regions, steps, elements, and/or components, but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and/or groups thereof.

As used herein, the conjunction “and” includes each of the structures, components, features, or the like, which are so conjoined, unless the context clearly indicates otherwise, and the conjunction “or” includes one or the others of the structures, components, features, or the like, which are so conjoined, singly and in any combination and number, unless the context clearly indicates otherwise.

All numeric values are herein assumed to be modified by the term “about,” whether or not explicitly indicated. The term “about,” in the context of numeric values, generally refers to a range of numbers that one of skill in the art would consider equivalent to the recited value (i.e., having the same function or result). In many instances, the term “about” may include numbers that are rounded to the nearest significant figure. Other uses of the term “about” (i.e., in a context other than numeric values) may be assumed to have their ordinary and customary definition(s), as understood from and consistent with the context of the specification, unless otherwise specified. The recitation of numerical ranges by endpoints includes all numbers within that range, including the endpoints (e.g. 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5).

It is noted that references in the specification to “an embodiment,” “some embodiments,” “other embodiments,” etc., indicate that the embodiment(s) described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it would be within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments, whether explicitly described, unless clearly stated to the contrary. That is, the various individual elements described herein, even if not explicitly shown in a particular combination, are nevertheless contemplated as being combinable or arrangeable with each other to form other additional embodiments or to complement and/or enrich the described embodiment(s), as would be understood by one of ordinary skill in the art.

The devices and/or methods disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure. While various embodiments of the devices and methods of this disclosure have been described, it may be apparent to those of skill in the art that variations can be applied to the devices and/or methods and in the steps or in the sequence of steps of the method described herein without departing from the concept, spirit and scope of the disclosure. All such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the spirit, scope and concept of the disclosure as defined by the appended claims.