Fixation device with symmetrical extension elements

Abstract

A fixation device for fixation of heart valve leaflets includes a central assembly and first and second arms each pivotally coupled to the central assembly. Each of the first and second arms include a trunk portion having a first end, a second end, and a longitudinal axis extending therebetween. The trunk portion has opposing lateral sides each extending between the first and second ends. Each of the first and second arms further include a coupling portion extending from the first end of the trunk portion. The coupling portion includes a pair of extension elements symmetrical about the longitudinal axis, and configured to be coupled to the central assembly for pivotal movement of the trunk portion relative the central assembly. The fixation device further includes first and second gripping elements each moveable relative to the first and second arms, respectively, to capture native leaflet tissue therebetween.

Description

FIXATION DEVICE WITH SYMMETRICAL EXTENSION ELEMENTSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of the filing date of U.S. Provisional Application No. 63 / 384,338, filed November 18, 2022, the disclosure of which is hereby incorporated herein by reference.FIELD OF DISCLOSED SUBJECT MATTER

[0002] The disclosed subject matter is directed to medical devices for the endovascular, percutaneous, or minimally invasive surgical treatment of bodily tissues, such as tissue approximation or valve repair. More particularly, the present disclosure relates to repair of valves of the heart and venous valves.

[0003] Surgical repair of bodily tissues can involve tissue approximation and fastening of such tissues in the approximated arrangement. When repairing valves, tissue approximation includes coapting the leaflets of the valves in a therapeutic arrangement which can then be maintained by fastening or fixing the leaflets. Such coaptation can be used to treat regurgitation, which commonly occurs in the mitral valve and in the tricuspid valve.

[0004] Mitral valve regurgitation is characterized by retrograde flow from the left ventricle of a heart through an incompetent mitral valve into the left atrium. During a normal cycle of heart contraction (systole), the mitral valve acts as a check valve to prevent flow of oxygenated blood back into the left atrium. In this way, the oxygenated blood is pumped into the aorta through the aortic valve. Regurgitation of the mitral valve can significantly decrease the pumping efficiency of the heart, placing the patient at risk of severe, progressive heart failure.

[0005] Mitral valve regurgitation can result from a number of different mechanical defects in the mitral valve or the left ventricular wall. The valve leaflets, the valve chordae which connect the leaflets to the papillary muscles, the papillary muscles or the left ventricular wall can be damaged or otherwise dysfunctional. Commonly, the valve annulus can be damaged, dilated, or weakened limiting the ability of the mitral valve to close adequately against the high pressures of the left ventricle.

[0006] Tricuspid valve regurgitation has several causes. Functional tricuspid valve regurgitation (FTR) is characterized by structurally normal tricuspid valve leaflets that are nevertheless unable to properly coapt with one another to close properly due to other structuraldeformations of surrounding heart structures. For example, the right ventricle can become dilated as a result of pulmonary hypertension or an abnormal heart muscle condition (cardiomyopathy).

[0007] Other causes of tricuspid valve regurgitation are related to degenerative valves and / or defects of the tricuspid valve leaflets, tricuspid valve annulus, or other tricuspid valve structures. In some circumstances, tricuspid valve regurgitation is a result of infective endocarditis, blunt chest trauma, rheumatic fever, Marfan syndrome, carcinoid syndrome, improper placement of pacemaker leads, or congenital defects to the structure of the heart.

[0008] Tricuspid valve conditions are also often associated with problems related to the left side of the heart, such as mitral valve regurgitation. In particular, FTR is often associated with left heart pathologies, though the tricuspid valve is typically left untreated during left heart surgeries. Left heart pathologies such as mitral valve regurgitation and stenosis can induce pressure and volume overload in the right ventricle, which in turn can induce ventricle enlargement and tricuspid annular dilation. Though often relatively mild at the time of treatment of the left heart, this annular dilation of the tricuspid valve can be progressive and asymmetric, and FTR can become more severe as time goes on. Reoperation for repair of the tricuspid valve is often needed owing to the degenerative character of the pathology.DESCRIPTION OF RELATED ART

[0009] Treatments for mitral and tricuspid valve regurgitation rely on valve replacement or repair including leaflet and annulus remodeling, the latter generally referred to as valve annuloplasty. Another technique for valve repair, which relies on suturing adjacent segments of opposed valve leaflets together is referred to as the “edge-to-edge” or “bow-tie” technique. The edge-to-edge technique can be performed via open chest access, but an endovascular approach is preferable. An endovascular approach can include an endovascular system wherein a catheter is advanced to the heart from a remote vasculature location. Furthermore, such endovascular system should allow for repositioning and optional removal of a fixation device (z.e., valve repair clip) prior to fixation to ensure optimal placement. Such endovascular system likewise can be useful for repair of tissues in the body other than heart valves.BRIEF SUMMARY OF THE DISCLOSURE

[0010] The purpose and advantages of the disclosed subject matter will be set forth in and apparent from the description that follows, as well as will be learned by practice of the disclosed subject matter. Additional advantages of the disclosed subject matter will be realized and attainedby the methods and systems particularly pointed out in the written description and claims hereof, as well as from the appended drawings.

[0011] To achieve these and other advantages and in accordance with the purpose of the disclosed subject matter, as embodied and broadly described, the disclosed subject matter is directed to a fixation device for treating a patient.

[0012] One aspect of the disclosed subject matter includes a fixation device for fixation of leaflets of a heart valve including a central assembly. The fixation device further includes a first arm and a second aim each pivotally coupled to the central assembly. Each of the first arm and the second arm include a trunk portion having a first end, a second end and a longitudinal axis extending therebetween. The trunk portion has opposing lateral sides, each lateral side extending between the first end and the second end. Each of the first arm and the second arm further include a coupling portion extending from the first end of the trunk portion, the coupling portion comprising a pair of extension elements symmetrical in shape to each other about the longitudinal axis and configured to be coupled to the central assembly for pivotal movement of the trunk portion from and toward a closed position relative the central assembly. The fixation device further includes a first gripping element and a second gripping element each moveable relative to the first arm and the second arm, respectively, to capture native leaflet tissue therebetween.

[0013] In accordance with aspects of the disclosed subject matter, each extension element can be a strut having a rectangular cross-section in end view. Each rectangular cross-section can have a width dimension that is transverse to the longitudinal axis of the trunk portion, and a height dimension that is orthogonal to the width dimension. Wherein the width dimension can be about 0.03 to 0.08 inch and the height dimension can be about 0.01 to 0.02 inch. In plan view of the arm, the pair of extension elements can each extend from the first end of the trunk portion in parallel to the to the longitudinal axis of the trunk portion. In side view of the arm, the pair of extension elements can each extend from the first end of the trunk portion at an extension element angle of between about 140 degrees and 160 degrees relative to the longitudinal axis of the trunk portion.

[0014] Further in accordance with the disclosed subject matter, the first and second aims can be configured to be moved to a collapsed position with the trunk portion of the first arm and the trunk portion of the second arm positioned in parallel to each other. In the collapsed position the first end of the trunk portion of the first arm can be spaced from the first end of the trunk portion of the second arm a distance of about 0.14 inch to 0.22 inch. The first and second arms canbe configured to be moved to a pinched position with the first end of the trunk portion of the first arm and the first end of the trunk portion of the second arm in contact with each other. In the pinched position the first end of the trunk portion of the first arm is spaced from the first end of the trunk portion of the second arm a distance of about 0.12 inch to about 0.16 inch.

[0015] The first arm can be moveable about a first pivot axis defined on the central assembly and the second arm can be moveable about a second pivot axis defined on the central assembly. The first pivot axis and the second pivot axis can be spaced from each other. The first pivot axis can include a first pivot pin coupled with the pair of extension elements of the first arm and the second pivot axis can include a second pivot pin coupled with the pair of extension elements of the second arm. The first pivot pin and the second pivot pin can be disposed in a slot joint defined within the central assembly. The first pivot pin can be disposed within a first opening in the central assembly and the second pivot pin can be disposed within a second opening in the central assembly. The first pivot axis and the second pivot axis each can comprise a rivet connection between the pair of extension elements of the coupling portion of the first arm and of the second arm, respectively, and the central assembly.

[0016] The first pivot pin and the second pivot pin each can extend through an entire width of the central assembly. In side view, an angle A is defined between the first arm and the second arm, wherein the first arm and the second arm can be in a fully inverted position when the extension elements of the arms touch each other, wherein the angle A between the arms in the fully inverted position can be about 300 degrees. Each extension element can include a top edge and a bottom edge, and wherein in the fully inverted position the bottom edges of the pair of extension elements of the first arm can be flush together with the bottom edges of the pair of extension elements of the second arm. In side view of the arm, the pair of extension elements each can extend from the first end of the trunk portion at an extension element angle relative to the longitudinal axis of the trunk portion, and the extension element angle can be about one half the angle A.

[0017] Further in accordance with aspects of the disclosed subject matter, the first arm can have at least one property that is different than the second arm. The at least one property can be configured to correspond to a first leaflet having at least one characteristic that is different from at least one characteristic of a second leaflet. The first arm can have a length different than the second arm. The first arm can have a width different than the second arm. The first arm can have a shape different than the second arm. The first arm can be made of at least one different material than thesecond arm. The first arm and the second arm can he different from each other by at least a property selected from the group consisting of mass, thickness, surface area, roughness profile, echogenicity, and flexibility. The fixation device can include a radiopaque marker on one of the first arm and the second arm wherein the other of the first arm and the second arm does not comprise a radiopaque marker. The first arm can include a substantially hollow frame structure comprising less than about 60% of the metal volume of the second arm, which can include a substantially full frame structure comprising at least 0.001 cubic inches of metal volume.BRIEF DESCRIPTION OF THE FIGURES

[0018] FIG. 1 is a perspective view of an exemplary embodiment of a fixation device for use in accordance with the disclosed subject matter.

[0019] FIGS. 2A-2C are side views of an alternative embodiment of a fixation device at various positions, wherein optional arms of greater length are depicted with dashed lines.

[0020] FIG. 3 is a plan view of an arm and gripping element of the fixation device of FIG. 1 in an open position.

[0021] FIG. 4 is a perspective view of a portion of an arm of the fixation device of FIG. 1.

[0022] FIG. 5 is a side view of the fixation device of FIG. 1, wherein the trunk portions of the arms are positioned parallel to each other.

[0023] FIG. 6 is a side view of the fixation device of FIG. 1, wherein when the arms are moved toward the closed position until the first arm and the second arm touch each other.

[0024] FIGS. 7A-7B are side views of a portion of the fixation device of FIG. 1, wherein the fixation device comprises a slot joint.

[0025] FIG. 8 is a side view of a portion of the fixation device of FIG. 1, wherein the fixation device comprises a double joint.

[0026] FIG. 9 is a front cross-sectional view of a portion of the fixation device of the FIG. 1, wherein the fixation device comprises a through joint.

[0027] FIG. 10 is a side view of the fixation device of FIG. 1 in an example of an inverted position.

[0028] FIG. 11 is a bottom view of an alternative embodiment of a fixation device in an example of an open position.

[0029] FIG. 12 is perspective view of the fixation device of FIG. 11 in an example of an open position.

[0030] FIG. 13 is a top view of an example of an interventional catheter assembly in accordance with the disclosed subject matter.DETAILED DESCRIPTION

[0031] Reference will now be made in detail to the various exemplary embodiments of the disclosed subject matter, exemplary embodiments of which are illustrated in the accompanying drawings.

[0032] The fixation device for use with the disclosed subject matter provides an edge-to- edge transcatheter valve repair option for patients having various conditions, including regurgitant mitral valves or tricuspid valves. Transcatheter (e.g., trans-septal) edge-to-edge valve repair has been established using a fixation device, such as the MitraClip Transcatheter Mitral Valve Repair device. These fixation devices generally are configured to capture and secure opposing native leaflets using two types of leaflet contacting elements. The first element is a sub-valvular arm (also known as a distal element or fixation element) to contact the ventricular side of a native leaflet to be grasped. With the arm positioned underneath to stabilize the native leaflet in a beating heart, a second gripping element (e.g., a proximal element) can be lowered or moved toward the arm and into contact with the atrial side of the native leaflet to capture the leaflet therebetween. Once each native leaflet is captured by a respective arm and gripping element, the fixation device can be closed by raising or moving the arms toward a center of the fixation device such that the leaflets are brought into coaptation, which results in a reduction in valvular regurgitation during ventricular systole. Furthermore, a covering can be provided on the arms and / or gripping elements to facilitate tissue ingrowth with the captured leaflets.

[0033] Additional details of exemplary fixation devices in accordance with the disclosed subject matter are set forth below. Furthermore, a number of patents and publications disclose additional details and aspects of such fixation devices and related operations. See for example, U.S. Pat. No. 7,226,467 to Lucatero et al , U.S. Pat. No. 7,563,267 to Goldfarb et al:, U.S. Pat. No. 7,655,015 to Goldfarb et al:, U.S. Pat. No. 7,736,388 to Goldfarb et al:, U.S. Pat. No. 7,811.296 to Goldfarb et al:, U.S. Pat. No. 8,057,493 to Goldfarb et al:, U.S. Pat. No. 8,303,608 to Goldfarb et al:, U.S. Pat. No. 8,500,761 to Goldfarb et al:, U.S. Pat. No. 8,734,505 to Goldfarb et al:, U.S. Pat. No. 8,740,920 to Goldfarb et al:, U.S. Pat. No. 9,510,829 to Goldfarb et al:, U.S. Pat. No. 7,635,329 to Goldfarb et al:, U.S. Patent Application Publication No. 2017 / 0042546 to Goldfarb et al:, U.S. Patent Application Publication No. 2017 / 0239048 to Goldfarb et al:, U.S.Patent Application Publication No. 2018 / 0325671 to Abunassar et al , U.S. Patent Application Publication No. 2021 / 0015607 to Abunassar et al:, U.S. Patent Application Publication No. 2021 / 0015614 to Kizuka et al , U.S. Patent Application Publication No. 2021 / 0106419 to Abunassar; U.S. Patent Application No. 17 / 124259, filed December 16, 2020; U.S. Provisional Application No. 63 / 092,110, filed October 15, 2020; and U.S. Provisional Patent Application No. 63 / 182,167, filed April 30, 2021, the entirety of the contents of each of these patents and published applications is incorporated herein by reference.

[0034] In grasping tissue and leaflet capture for mitral valve and tricuspid valve disease, certain patient conditions and anatomies, such as those associated with thick leaflets, high stresses can occur at certain leaflet locations when coapted by an edge-to-edge fixation device. For certain anatomies, a fixation device having symmetrical joint configuration (e.g., joints without asymmetrical jog features) can reduce leaflet stress while improving the fixation device leaflet coaptation. For example, a symmetrical joint can facilitate a fixation device configured with arms having separate, off-center rotation points. Off-center rotation points can allow for additional space between the arm and a central assembly of the fixation device, particularly proximate the rotation point. Additional space proximate the rotation point can enable coaptation of thick leaflets without causing excess stress while maintaining leaflet coaptation behavior through the rest of the arm. Furthermore, a symmetrical joint configuration can increase performance of the gripping element component by decreasing potential lateral migration into a space created by the jog arm.

[0035] Additionally, a symmetrical joint configuration having an off-center rotation point can enable a fixation device to be positioned in an inverted configuration wherein the width dimension is narrowed. A narrowed width in the inverted position can increase maneuverability of the fixation device during device repositioning and retraction back through a heart valve without getting entangled in chordae or inducing valve trauma.

[0036] Furthermore, a symmetrical joint configuration having an off-center rotation point can enable a hinge configuration that passes completely through a central assembly. A centered rotation point is aligned with a shaft or rod passing through a center of the central assembly, so a hinge cannot pass completely through. In such a centered construction, arms of the fixation device may overlap so that each arm is connected to the same hinge and rotates about the same rotation point which may require the arms to have asymmetric jog features to provide clearance for the other arm. By contrast, an off-center rotation point allows the hinge to pass through the centralassembly next to the centered shaft or rod, thus forming a through joint. A through joint can improve manufacturing (e.g., eliminate the need for welding) and reduce tolerance requirements. Furthermore, joint components used at other locations (e.g., at the arm and leg joint) can be utilized in the arm central assembly joint. Regarding performance, a through joint is more stable and can increase predictability in leaflet capture, particularly regarding lateral gripping motion and twisting motions, even in certain misuse scenarios.

[0037] Moreover, a symmetrical joint configuration can result in a fixation device having a simplified design (e.g., through joints) wherein components can be manufactured with lower tolerance requirements without sacrificing reliability or performance. Furthermore, more consistent, less expensive, and less heat intensive manufacturing techniques can be utilized. For example, certain types of welds and certain sheet metal stamps, such as jogs or offsets, can be avoided while still maintaining a parallel positioning of two arms at the same plane. Manufacturing techniques utilizing lower heat can reduce undesired deformation and increase uniformity in components. Additionally, symmetric parts can be easier to fixture and inspect compared to more complex asymmetric parts.

[0038] In accordance with another aspect of the disclosed subject matter, a fixation device can have different arms, wherein one arm has at least property that is different from another arm on the device. In particular, the property of one arm can be different to accommodate a different property between two leaflets. Known diagnostic processes can be utilized to determine differences in leaflet properties within the same heart valve. For example, a prolapsed, flailed or Barlowed leaflet can be identified wherein the leaflet can have calcified or variable thickness. For example, one arm can be configured for a relatively thick and frail posterior leaflet and the other arm can be configured for a relatively thin and resilient anterior leaflet. As another example, a short arm can be used to avoid calcium in a leaflet, while a long arm can be used to better treat a long billowing / prolapsing leaflet. Overall, matching certain leaflets to particular arm configurations can improve stress distribution in a grasped leaflets and lead to improved procedural results.

[0039] When the arms have a different property from each other, imaging (e.g., fluoroscopic imaging) needs to be considered to enable a user to distinguish the two arms during a surgical procedure. For example, arms having a distinctly different shapes (e.g., a hollow frame versus a full frame) can be easily distinguished over imaging because the shape would result ingrossly different echo features. However, arms having other property differences (e.g., different roughness profiles) can be indistinguishable from each other over imaging. As such, a feature detectable over imaging (e.g., a radiopaque marker) can be added to one of the arms.

[0040] Generally, and as set forth in greater detail below, the disclosed subject matter provided herein includes a fixation device for fixation of leaflets of a heart valve, wherein the fixation includes a central assembly. The fixation device further includes a first arm and a second arm each pivotally coupled to the central assembly. Each of the first arm and the second arm include a trunk portion having a first end, a second end and a longitudinal axis extending therebetween. The trunk portion has opposing lateral sides, each lateral side extending between the first end and the second end. Each of the first arm and the second arm further include a coupling portion extending from the first end of the trunk portion, the coupling portion comprising a pair of extension elements symmetrical in shape to each other about the longitudinal axis and configured to be coupled to the central assembly for pivotal movement of the trunk portion from and toward a closed position relative the central assembly. The fixation device further includes a first gripping element and a second gripping element each moveable relative to the first arm and the second arm, respectively, to capture native leaflet tissue therebetween.

[0041] Referring to FIG. 1 for the purpose of illustration and not limitation, a fixation device 104 for fixation of native leaflets of a heart valve is disclosed herein. The fixation device 104 as embodied herein includes a central assembly 171 defining a central axis 194. The central assembly 171 can include various central components for operation and release of the fixation device, such as a detachment mechanism. The first arm 108 can be moveable about a first pivot axis 166 defined on the central assembly and the second arm 110 can be moveable about a second pivot axis 168 defined on the central assembly 171. As shown, the first pivot axis 166 and the second pivot axis 168 can be spaced from each other. The first pivot axis 166 can include a first pivot pin 167 coupled with the first arm 108 and the second pivot axis 169 can include a second pivot pin 169 coupled with the second arm 110. The first arm 108 and the second arm 110 can each have a length dimension of about between about .322 inch and about .622 inch. The length of the arm can be selected for a particular patient anatomy (e.g., a fixation device having relatively long arms can be selected for certain patient valve anatomies).

[0042] For purpose of illustration, and not limitation, the distal portion 106 further includes at least one leg 120, 122 operatively coupled to the arm 108, 110 and configured to move the arm108, 110 to a selected position between a fully closed position, an open position, and an inverted position. The legs can have connection locations at each end, wherein the distance between the connection locations is between about 0.19 inch and about 0.29 inch, and preferably about 0.24 inch, although other suitable distances can be used. Additionally, the central assembly 171 can include a base portion 124 coupled to the at least one leg 120, 122, wherein distal movement of the base portion 124 can move the at least one leg 120. 122 to move the arm 108, 110 towards the fully open position. Furthermore, the base portion 124 can be operatively connected with a stud 126 which can be operatively attached to an actuator rod 128. In some embodiments, the stud 126 can be threaded so that a distal end of the actuator rod 128 can attach to the stud 126 by a screwtype action. Further, the connection point between the stud 126 and the actuator rod 128 can be disposed within the central assembly 171, as in the illustrated example. However, the actuator rod 128 and stud 126 can be operatively connected by any mechanism which is releasable to allow the fixation device 104 to be detached. The stud 126 can be axially extendable and retractable to move the base portion 124 and therefore the legs 168, 169 which pivot the arms 108, 110 between closed, open, and inverted positions. The fixation device 104 can further include a locking mechanism 129 configured to prevent distal movement of the base portion 124 according to some examples. Further details regarding the fixation device components and operation are disclosed in the patents and publications incorporated by reference herein.

[0043] As depicted herein in FIGS. 2A-2C, various positions of the fixation device 104 are depicted for purpose of illustration and not limitation. Arms of longer length are illustrated in dashed lines as one example for comparison to shorter arms of another example. In FIG. 2A, the fixation device arms are positioned axially in alignment, e.g., vertically, or nearly vertically, as shown. FIGS. 2B and 2C illustrate the arms positioned with an angle A between each other. In FIG. 2B, angle A is about 10 degrees (+ / - 5 degrees) and in FIG. 2C angle A is about 60 degrees (+ / - 5 degrees). As disclosed herein, the fixation device is in the closed position when angle A is about 30 degrees or less (+ / - 5 degrees), although another angle can result when leaflets of greater thickness are captured therebetween. Although not depicted in FIG. 2, the aims can continue to open after angle A exceeds 180 degrees, e.g., inverted (shown in FIG. 10).

[0044] With reference back to FIG. 1, and in accordance with the disclosed subject matter, the fixation device 104 further includes a first gripping element 116 and a second gripping element 118 each moveable relative to the first arm 108 and the second arm 110, respectively, to capturenative leaflet tissue therebetween. The gripping element 116, 118 can be moveable relative to the arm 108, 110 to capture a second native leaflet therebetween. In particular, the gripping clement 116, 118 has a first end 130 coupled to a portion of the fixation device and a free end 132 moveable relative to the arm 108, 110. As embodied in the illustrated example, each gripping element 116, 118 can include a plurality of friction elements 152, in some cases, positioned in rows. For example, each gripping element 116, 118 can have at least four rows of friction elements 134. The friction elements 134 can allow for improved tissue engagement during leaflet capture. If the fixation device requires adjustment after an initial leaflet capture, the arms can be opened (e.g., opened to the inverted position shown in FIG. 10), the gripping element can be raised vertically, and tissue can disengage from the fixation device, facilitating later re-capture.

[0045] With continued reference to FIG. 1, each gripping element 116, 118 can be biased toward each respective arm 108, 110 in some examples. Prior to leaflet capture, each gripping element 116, 118 can be moved inwardly toward a longitudinal center of the device (i.e., away from each respective arm 108, 110) and held with the aid of one or more gripping element lines (not shown) which can be in the form of sutures, wires, rods, cables, polymeric lines, or other suitable structures. The gripping element lines can be operatively connected with the gripping elements 116, 118 in a variety of ways, such as by being threaded through loops (not shown) disposed on the gripping elements 116, 118.

[0046] In accordance with the disclosed subject matter, and with further reference to the embodiment disclosed in FIG. 3, for purpose of illustration and not limitation, a first arm 108 is illustrated in plan view. Any feature of the first arm 108 disclosed herein can likewise be a feature of the second arm 110 (or any other arm of an example of disclosure). As illustrated, the first arm 108 includes a trunk portion 150 having a first end 152, a second end 154 and a longitudinal axis 190 defined therebetween. The trunk portion 150 has opposing lateral sides 158, each lateral side 158 extending between the first end 152 and the second end 154.

[0047] The first arm 108 further includes a coupling portion 140 extending from the first end 152 of the trunk portion 150. In one example, the coupling portion 140 comprises a pair of extension elements 160 symmetrical in shape to each other about the longitudinal axis 190 and equidistant from longitudinal axis 190. The pair of extension elements 160 are, in one example, configured to be coupled to the central assembly 171 for pivotal movement of the trunk portion 150 from and toward a closed position relative the central assembly. The dimension 163 betweenthe pair of extension elements 160 can be between about 0.102 inch and 0.152 inch and preferably about 0.127 inch, although other suitable dimensions can be used. In plan view of the arm 108, 110, the pair of extension elements 160 each extend from the first end 152 of the trunk portion 150 in parallel to the to the longitudinal axis 190 of the trunk portion 150 according to various examples.

[0048] With reference back to FIG. 1 in particular, the first pivot pin 167 can be coupled with the pair of extension elements 160 of the first arm 108 and the second pivot pin 169 can be coupled with the pair of extension elements 160 of the second arm 110 in one example. The dimension between the pair of extension elements 160 can be sized to tightly fit the gripping element 116 therebetween in one example. The pair of extension elements 160 having a symmetrical shape can allow for a tight fit of the gripping element 116 because an equal amount of space can be provided on each side of the gripping element 116. A tight fit of the gripping element 116 can advantageously control and guide movement of the gripping element 116 in certain circumstances, for example, during a torsion force on the gripping element 116 caused during an implantation procedure.

[0049] Referring in addition to FIG. 4, in one example, each of the pair of extension elements 160 can include a through-hole 161 for connection to the central assembly 171. Each through-hole 161 can be the same size. Turning back to FIG. 1, each coupling portion 140 of the first arm 108 and the second arm 110 can be moveable about a first pivot axis 166 and a second pivot axis 168, respectively, on the central assembly 171. Each extension element 160 can be a strut having a rectangular cross-section in end view as is best shown in FIG. 4. In some examples, each rectangular cross-section can have a width dimension 191 that is primarily transverse to the longitudinal axis 190 of the trunk portion and that extends from an inner surface to an outer surface of the respective extension elements 160 of the first and second arms 108, 110, and a height dimension 196 that is orthogonal to the width dimension 191. The width dimension 196 can be about 0.03 to 0.08 inch or preferably about 0.05 inch, although other suitable width dimensions can be used. The height dimension 196 can be about 0.01 to 0.02 inch or preferably about 0.015 inch, although other suitable height dimensions can be used. It is also contemplated that extension elements 160 may have other cross-sectional shapes, such as circular, for example. As mentioned above, in one example, each extension element 160 is equidistant from the longitudinal axis 190. In this regard, when each extension element 160 is rectangular in shape, for example, the innersurfaces of the extension elements 160 are equidistant from the longitudinal axis 190, and the outer surfaces of the extension elements 160 arc equidistant from the longitudinal axis 190. Where other cross-sectional shapes are utilized, the inner and outer extents of the cross-sectional width dimensions of the extension elements 160 are similarly equidistant from the longitudinal axis 190.

[0050] In accordance with another aspect of the disclosed subject matter, and as shown in FIG. 5, in side view of the arm 108, 110, the pair of extension elements 160 each extend from the first end 152 of the trunk portion 150 toward each other and at an extension element angle 182 of between about 140 degrees and 160 degrees, or preferably about 150 degrees relative to the longitudinal axis 190 of the trunk portion 150, although other suitable angle dimensions can be used. Additionally or alternatively, the pair of extension elements 160 each extend from the first end 152 of the trunk portion 150 at a supplemental angle 183 of between 20 to 40 degrees, or preferably about 30 degrees relative to the longitudinal axis 190 of the trunk portion 150, although other suitable angle dimensions can be used. In other words, in some examples, the pair of extension elements 160 extend at an oblique angle relative to their respective trunk portion 150 and toward central axis 194.

[0051] As further shown in FIG. 5, the first and second arms 108, 110 can be configured to be moved to a collapsed position with the trunk portion 150 of the first arm 108 and the trunk portion 150 of the second arm 110 positioned in parallel to each other. In one example of the collapsed position, the first end 152 of the trunk portion 150 of the first arm 108 is spaced from the first end 152 of the trunk portion 150 of the second arm 110 a distance 162 of about 0.14 inch to 0.22 inch, or preferably about 0.18 inch, although other suitable distance dimensions can be used.

[0052] As further embodied herein in FIG. 6, in this example, the first and second arms 108, 110 are configured to be moved to a pinched position with the first end 152 of the trunk portion 150 of the first arm 108 and the first end 152 of the trunk portion 150 of the second arm 110 in contact with each other. In the example of the pinched position, the first end 152 of the trunk portion 150 of the first arm 108 is spaced from the first end 152 of the trunk portion 150 of the second arm 110 a distance 162 of about 0.12 inch to about 0.16 inch, or preferably 0.14 inch, although other suitable distance dimensions can be used. The distance 162 may also increase if tissue is inserted in the device arms, for example, if valve leaflets cause the pinched position to become obstructed where the trunk portions 150 are parallel in a manner similar to the collapsedconfiguration in FIG. 5, where the distance 162 is about 0.14 inch to 0.22 inch, or preferably about 0.18 inch, although other suitable distance dimensions can be used.

[0053] As is perhaps best shown in the example of FIGS. 5 and 6, the first pivot axis 166 and the second pivot axis 168 are separate from each other and off-center relative the central axis 194 of the fixation device. This off-center configuration allows for additional space between each arm 108, 110 and the central assembly 171, as compared to a center axis configuration. In other words, in a center axis configuration, a single pivot axis of arms 108, 110 intersects central axis 194, but in the off-center or offset configuration of FIGS. 5 and 6, first and second pivot axes 166, 168 may be offset from central axis 194 and located at opposite sides thereof. As shown, there is additional space particularly proximate the pivot axes 166, 168, which can enable coaptation of thick leaflets without excess stress. Further, leaflet coaptation behavior through the rest of the arms 108, 110 (i.e., the portions of the arms spaced from the pivot axis) can be maintained.

[0054] As best shown in FIGS. 1, 7A, and 7B, the first pivot pin 167 with first pivot axis 166 and the second pivot pin 169 with first pivot axis 168 can be disposed in a slot joint 176 defined within the central assembly 171 according to one example. In one example, the slot joint 176 can comprise a single opening, which may be elongate in a direction transverse to central axis 194, with the first pivot pin 167 and the second pivot pin 169 disposed therein. As in the illustrated example, the first pivot pin 167 and the second pivot pin 169 are both disposed off-center within the slot joint 176, which allows for a central shaft to extend along central axis 194 of the fixation device 104 and between pivot pins 167 and 169.

[0055] Turing now in addition to FIG. 8, and in accordance with another aspect of the disclosed subject matter, the first pivot pin 167 can be disposed within a first opening 178 in the central assembly 171 and the second pivot pin 169 can be disposed within a second opening 179 in the central assembly 171. As in the illustrated example, the first pivot pin 167 and the second pivot pin 169 can both be disposed off-center relative the central axis 194. The double joint shown in the example of FIG. 8 offers the advantage of discrete positioning of the first pivot pin 167 and second pivot pin 169 such that their position is at a controlled and discreet distance from the fixation device central shaft, which runs along central axis 194. This design choice therefore provides assurance of controlled clearance between pivot pins 167 and 169 and the central shaft used to actuate the fixation device. The combined slot joint shown in the example of FIG. 7A and FIG. 7B may allow resistance to occur during any movement of pins 167 and 169 and central shaftof the device but allows for a smaller housing component to be used, contributing to a smaller overall device size. Additionally, in one example, the first pivot axis 166 and the second pivot axis168 can each comprise a rivet connection between the pair of extension elements 160 of the coupling portion 140 of the first arm 108 and of the second arm 110, respectively, and the central assembly 171. The first and second pivot pins 167 and 169 may be welded to extension elements, or may be more preferably rivetted for security through extension elements and through slot 176 or holes 178 and 179 according to one example. Riveting may be preferable to welding as heat generated from the welding process can warp extension elements 160.

[0056] As shown in the example of FIG. 9, the first pivot pin 167 and the second pivot pin169 can each extend through an entire width of the central assembly. For example, the pivot pin can be a through pin 182. A through pin 182 can be used in conjunction with off-center joint configurations, such as the slot joint 176, the first opening 178, and the second opening 179 described above according to various examples of the disclosure. The through pin 182 can be used in off-center joint configurations wherein the axis of rotation of the joint avoids the delivery shaft 128, which passes through a center of the fixation device according to various examples. A through pin 182 can increase stability of the arms 108, 110, particularly with lateral gripping motion and twisting motions. Additionally, the implementation of a through pin 182 by virtue of the off-center configurations can simplify construction and assembly as compared to a center axis configuration which may require tighter tolerances for alignment of two separate pivot pins at opposite sides of the delivery shaft 128 and may preclude a rivet option.

[0057] In accordance with another aspect of the disclosed subject matter, in some situations, it can be desired to reposition or remove the fixation device 104 after a deployment to capture native leaflet tissue. Such repositioning or removal can be desired for a variety of reasons, such as to reapproach a valve in an attempt to achieve better valve function, to achieve more optimal positioning of device 104, to detangle the device 104, to exchange the device 104 with one having a different design, or to abort the procedure. To facilitate repositioning or removal, the fixation device 104 can be invertible to a configuration that can reduce tangling, interfering, or damaging the chordae, leaflets, or other tissue. In the inverted position, the fixation device 104 can be repositioned to a desired orientation wherein the arms 108, 110 can then be reverted to a grasping position against the leaflets. Alternatively, the fixation device 104 can be withdrawn back through the valve leaflets. Once the device 104 has been withdrawn through valve leaflets, thearms 108, 110 be moved to a collapsed position or any other configuration suitable for removal from the body or for reinsertion through the valve.

[0058] As shown in FIG. 10, in side view an angle A is defined between the first arm 108 and the second arm 110, wherein the first arm 108 and the second arm 110 can be in an example of a fully inverted position in which the extension elements 160 of the arms touch each other. The angle A between the arms 108, 110 in the example of the fully inverted position can be about 280 to about 320 degrees, or preferably about 300 degrees, although other suitable angle dimensions can be used. Each extension element 160 includes a top edge 186 and a bottom edge 188, and in the fully inverted position the bottom edges 188 of the pair of extension elements 160 of the first arm 108 can be flush together with the bottom edges 188 of the pair of extension elements 160 of the second arm 110. According to one example, in side view of the arm 108, 110, the pair of extension elements 160 each extend from the first end of the trunk portion at an extension element angle 182 relative to the longitudinal axis of the trunk portion 150, and the extension element angle can be about one half the angle A (+ / - 5 degrees). In the fully inverted position, a lateral profile of the fixation device 173 can be between about 0.36 inch to about 0.48 inch and preferably about .44 inch, although other suitable dimensions can be used. Symmetrical, off-center arms can allow increased angle A in the inverted position which can result in a narrow profile of the fixation device 104. A narrow profile can allow the fixation device to more easily traverse through anatomic structures without getting entangled in chordae or inducing valve trauma.

[0059] As further embodied herein in FIGS. 11-12, the first arm 108 can have at least one property that is different than the second arm 110. The at least one property can be configured to correspond to a first leaflet having at least one characteristic that is different from at least one characteristic of a second leaflet. The first arm 108 can have at least one of a length, a width, and a shape property different than the second arm 110 in various examples. For example, the lengths of each arm 108, 110 can be selected to match the lengths of corresponding leaflets. The length dimensions may differ from one side to another by about 25% to 100%, but preferably 50% on the longer side. Widths may be different between the two sides such that the wider side is 25% wider to 300% wider than the other side, or preferably 150% to 200% wider. This geometry matching approach can provide more uniform leaflet strains and leaflet forces in the grasped leaflets, providing better long-term valve biomechanics and enabling more stability in reducing mitral regurgitation. As shown in the example of FIGS. 11-12, the first arm 108 can include asubstantially hollow frame structure comprising less than about 60% of the metal volume of the second arm, which can include a substantially full frame structure comprising at least 0.001 cubic inches of metal volume. Additionally, openings defined by the frame of first arm 108 can be larger than openings defined by the frame of the second arm 110. Further, the first arm 108 can be made of at least one different material than the second arm 110. The first arm 108 and the second arm 110 can be different from each other by at least a property selected from the group consisting of mass, thickness, density, surface area, roughness profile, echogenicity, radiopacity, alloy type, covering type, and flexibility. The example fixation device 104 can be configured wherein one of the first arm 108 and the second arm 110 comprises a radiopaque marker (not shown) and the other of the first arm 108 and the second arm 110 does not comprise a radiopaque marker. Such radiopaque marker may allow a surgeon to identify the arms 108. 110 of different characteristics under medical imaging guidance so that they can be applied to the appropriate valve leaflet.

[0060] Referring in addition to FIG. 13 for purpose of illustration and not limitation, an exemplary interventional catheter assembly 200 is provided for delivery of a fixation device (e.g., the fixation device 104). That is, the interventional catheter assembly 200 can be used to introduce and position the fixation device 104. The examples of the interventional catheter assembly 200 can include an interventional catheter 202, having a proximal end portion 222 and a distal end portion 224, and a handle 204 attached to the proximal end portion 222. The fixation device 104 can be removably coupleable to the distal end portion 224 for delivery to a site within the body, for example, the mitral valve or the tricuspid valve. Extending from the distal end portion 224 is actuator rod 128. In this example, the actuator rod 128 is connectable with the fixation device 104 and can act to manipulate the fixation device 104, for example, opening and closing the arms. Handle 204 of the interventional catheter assembly 200 is shown as one suitable example, including main body 208, gripping element line handle 212, lock line handle 210, actuator rod control 214, and actuator rod handle 216, among other features.

[0061] During one example of a procedure, to access a valve, such as a mitral valve or a tricuspid valve, the interventional catheter 202 can be inserted from a puncture in the femoral vein, through the inferior vena cava and into the right atrium. For access to the mitral valve, the interventional catheter 202 can, in one example, extend through a puncture in a fossa of the interatrial septum and curve so that the distal end portion 224 is directed over the mitral valve. For access to the tricuspid valve, the interventional catheter 202 can curve in the right atrium so thatthe distal end portion 224 is directed over the tricuspid valve. For any valve, the distal end portion 224 can be centered over an opening between the leaflets of the valve. The distal end portion 224 can be lowered into the valve, thereby lowering the fixation device 104 into the ventricle. The distal end portion 224 can be raised and lowered as desired for a procedure, such as a regurgitation correction procedure. Prior to a procedure, imaging and various tests can be performed to anticipate and diagnose a patient’s individual circumstances and assist a physician in selecting a fixation device having the desired parameters.

[0062] While various embodiments disclosed herein utilize a push-to-open, pull-to-close mechanism for opening and closing arms it should be understood that other suitable mechanisms can be used, such as a pull-to-open, push-to-close mechanism. Likewise, other actuation elements can be used for deployment of the gripping elements.

[0063] The components disclosed herein, such as the example arm and leg components 108, 110, 120, 122, can be formed with an alternative geometry by manufacturing from tubing. For example, tube cutting manufacturing techniques can be used wherein each component would have a “C” shaped cross section (e.g., a “half pipe”) cut from a tube to create a trough for the arms 108, 110 and a profile for the legs 120, 122.

[0064] Although the subject matter disclosed herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications exemplified by such embodiments. It is therefore to be understood that numerous modifications may be made to the exemplary embodiments and that other arrangements may be devised such as combining one or more features of one embodiment with another embodiment or features from a plurality of embodiments, as an example. Thus, the exemplary embodiments herein are not intended to be exhaustive or to limit the disclosed subject matter to those embodiments disclosed.

Claims

CLAIMS1. A fixation device for fixation of leaflets of a heart valve, the fixation device comprising: a central assembly; a first arm and a second arm each pivotally coupled to the central assembly, each of the first arm and the second arm comprising: a trunk portion having a first end, a second end and a longitudinal axis extending therebetween, the trunk portion having opposing lateral sides, each lateral side extending between the first end and the second end, and a coupling portion extending from the first end of the trunk portion, the coupling portion comprising a pair of extension elements symmetrical in shape to each other about the longitudinal axis and configured to be coupled to the central assembly for pivotal movement of the trunk portion from and toward a closed position relative the central assembly; and a first gripping element and a second gripping element each moveable relative to the first arm and the second arm.

2. The fixation device of claim 1, wherein each extension element is a strut having a rectangular cross-section in end view.

3. The fixation device of claim 2, wherein each rectangular cross-section has a width dimension that is transverse to the longitudinal axis of the trunk portion, and a height dimension that is orthogonal to the width dimension.

4. The fixation device of claim 3, wherein the width dimension is about 0.03 to 0.08 inch and the height dimension is about 0.01 to 0.02 inch.

5. The fixation device of claim 1, wherein the pair of extension elements are equidistant from the longitudinal axis of the trunk portion.

6. The fixation device of claim 1, wherein in plan view of the arm, the pair of extension elements each extend from the first end of the trunk portion in parallel to the to the longitudinal axis of the trunk portion.

7. The fixation device of claim 1 , wherein in side view of the arm, the pair of extension elements each extend from the first end of the trunk portion at an extension element angle of between about 140 degrees and 160 degrees relative to the longitudinal axis of the trunk portion.

8. The fixation device of claim 1 , wherein the first and second arms are configured to be moved to a collapsed position with the trunk portion of the first arm and the trunk portion of the second arm positioned in parallel to each other.

9. The fixation device of claim 8, wherein in the collapsed position the first end of the trunk portion of the first arm is spaced from the first end of the trunk portion of the second arm a distance of about 0.14 inch to 0.22 inch.

10. The fixation device of claim 1, wherein the first and second arms are configured to be moved to a pinched position with the first end of the trunk portion of the first arm and the first end of the trunk portion of the second arm in contact with each other.

11. The fixation device of claim 10, wherein in the pinched position the first end of the trunk portion of the first arm is spaced from the first end of the trunk portion of the second arm a distance of about 0.12 inch to about 0.16 inch.

12. The fixation device of claim 1, wherein the first arm is moveable about a first pivot axis defined on the central assembly and the second arm is moveable about a second pivot axis defined on the central assembly.

13. The fixation device of claim 12, wherein the first pivot axis and the second pivot axis are spaced from each other.

14. The fixation device of claim 13, wherein the first pivot axis is disposed at an opposite side of the longitudinal axis of the trunk portion than the second pivot axis.

15. The fixation device of claim 13, wherein the first pivot axis includes a first pivot pin coupled with the pair of extension elements of the first arm and the second pivot axis includes a second pivot pin coupled with the pair of extension elements of the second arm.

16. The fixation device of claim 15, wherein the first pivot pin and the second pivot pin are disposed in a slot joint defined within the central assembly.

17. The fixation device of claim 15, wherein the first pivot pin is disposed within a first opening in the central assembly and the second pivot pin is disposed within a second opening in the central assembly.

18. The fixation device of claim 15, wherein the first pivot axis and the second pivot axis each comprises a rivet connection between the pair of extension elements of the coupling portion of the first arm and of the second arm, respectively, and the central assembly.

19. The fixation device of claim 15, wherein the first pivot pin and the second pivot pin each extends through an entire width of the central assembly.

20. The fixation device of claim 1, wherein in side view an angle A is defined between the first arm and the second arm, wherein the first arm and the second arm are in a fully inverted position when the extension elements of the arms touch each other, wherein the angle A between the arms in the fully inverted position is about 300 degrees.

21. The fixation device of claim 20, wherein each extension element includes a top edge and a bottom edge, and wherein in the fully inverted position the bottom edges of the pair of extension elements of the first arm are flush together with the bottom edges of the pair of extension elements of the second arm.

22. The fixation device of claim 21, wherein in side view of the arm, the pair of extension elements each extend from the first end of the trunk portion at an extension element angle relative to the longitudinal axis of the trunk portion, and the extension element angle is about one half the angle A.

23. The fixation device of claim 1 , wherein the first arm has at least one property that is different than the second arm.

24. The fixation device of claim 23, wherein the at least one property is configured to correspond to a first leaflet having at least one characteristic that is different from at least one characteristic of a second leaflet.

25. The fixation device of claim 23, wherein the first arm has a length different than the second arm.

26. The fixation device of claim 23, wherein the first arm has a width different than the second arm.

27. The fixation device of claim 23, wherein the first arm has a shape different than the second arm.

28. The fixation device of claim 23, wherein the first arm is made of at least one different material than the second aim.

29. The fixation device of claim 23, wherein the first arm and the second arm are different from each other by at least a property selected from the group consisting of mass, thickness, surface area, roughness profile, covering type, alloy type, density, radiopacity, echogenicity, and flexibility.

30. The fixation device of claim 23, wherein one of the first arm and the second arm comprises a radiopaque marker and the other of the first arm and the second arm docs not comprise a radiopaque marker.

31. The fixation device of claim 23, wherein the first arm comprises a hollow frame structure defining at least one opening extending therethrough, the second arm comprises a full frame structure defining at least one opening extending therethrough, the at least one opening of the second arm being smaller than the at least one opening of the first arm.

32. The fixation device of claim 23, wherein the first aim comprises a substantially hollow frame structure comprising less than about 60% of the metal volume of the second arm, which can include a substantially full frame structure comprising at least 0.001 cubic inches of metal volume.

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