Bonding device

Abstract

An implantable prosthesis and delivery system for the treatment of tricuspid regurgitation. The system is configured for preloading into a percutaneous delivery system and includes a self-expanding anchor stent with an attachable and positionable junction member. The stent is implanted in the inferior vena cava near the right atrium and is connected to the junction member via a multi-directional coupler and gimbal assembly. The junction member is manufactured from a porous or semi-porous material formed on a wire frame and is configured, prior to implantation, with a curvature that optionally matches the valve leaflets. When deployed, the junction member conforms to the defect of the patient's tricuspid valve and self-aligns and self-expands over several cardiac cycles to obtain a shape for providing a bonding surface to the native valve leaflets to reduce TVR.

Description

Technical Field

[0001] The present invention relates most generally to medical devices, and more specifically to a tricuspid valve prosthesis provided with a highly efficient joint surface for use in the treatment of tricuspid regurgitation (TR) in the anatomical structures of various patients.

Background Art

[0002] This description and the accompanying drawings describe a novel tricuspid valve prosthesis while highlighting novel features related to the ability to provide a highly efficient joint surface in the treatment of tricuspid regurgitation (TR) in the anatomical structures of various patients.

[0003] The tricuspid valve (TV) includes a plurality of arrangements of native valve leaflets and a corresponding circumferential tissue, an annulus, inside the right heart structure. The inferior vena cava (IVC) returns deoxygenated blood to the right atrium (RA), and the blood then flows through the TV into the right ventricle (RV) and ultimately to the lungs where it is reoxygenated. In TVR, the tricuspid valve between the right atrium and the right ventricle does not close properly after blood is pumped from the right atrium into the right ventricle. Inappropriate junctions between native valve leaflets (anterior, posterior, septal) can result from several causes including dilation of the TV annulus, structural damage to the chordae tendineae, and impairment of the papillary muscles. As a result of the inappropriate junction, blood regurgitates from the right ventricle into the right atrium when the ventricular systolic pressure is high during ventricular systole.

[0004] Designing a medical device that effectively reduces a patient's TR is a challenging problem. When pharmacological interventions such as diuretics or vasodilators are ineffective, there are currently two main solutions: (1) a mechanical solution that reconstructs the shape and size of the TV annulus to force the valve leaflets to come closer together for coaptation, which increases the risk to delicate tissue, and (2) inserting a "gap-closing" device to prevent or reduce TV TR by joining with the native valve leaflets.

[0005] The design presented in this application targets the latter type of solution, where a novel and improved coaptation device can be safely fixed to the IVC and easily positioned inside the TV valve leaflets. The coaptation device of the present invention is unique in that it can move freely on multiple axes, which prevents contact with the native valve leaflets and thus avoids the occurrence of new TR. The novel three-dimensional shape of the coaptation member precisely conforms to what is "necessary" to reduce TR.

Summary of the Invention

[0006] In the most important aspect, the tricuspid valve prosthesis of the present invention includes an IVC stent made of nickel-titanium (nitinol) and configured to be positioned in the IVC near the junction of the right atrium (RA) and the IVC. Thereby, the stent secures the tricuspid valve prosthesis to the IVC itself. A coupler connects the IVC stent to a gimbal, which in turn connects the coupler to a coaptation member (hereinafter referred to as the "coaptation sail"), resulting in multi-axis rotation of the coaptation sail relative to the coupler inside the TV annulus. The coaptation sail includes a three-dimensional shaped nitinol wireframe covered with, surrounded by, or housed within various porous and non-porous fabric materials. The coaptation sail is attached to the gimbal by sutures, and in an embodiment, the nitinol wireframe is also held in the gimbal structure. When deployed, the fabric-covered coaptation sail extends partially into the center of the TV, providing a coaptation surface for the native TV valve leaflets.

[0007] Delivery, implantation, and deployment of the engagement sail are achieved using the delivery system described in the concurrently filed International Patent Application No. PCT / US23 / 69296 (filed June 28, 2023), which is incorporated herein by reference in its entirety.

[0008] The TR patient population includes numerous anatomical variations that deviate from basic dimensions such as the diameter of the IVC and the size of the TV annulus. The orientation of the patient's IVC ostium (IVC ostium plane) and the distance to the TV annulus, as well as the orientation of the TV annulus (TV annulus plane), present additional challenges when positioning the engagement sail. However, the orientation and position of the engagement sail in the three-dimensional space of the RA and TV annulus are crucial for successful reduction of TR. Therefore, several prosthesis functions are required and provided to enable the engagement system of the present invention to treat the anatomical structures of a wide variety of TR patient populations. Accordingly, variations may be included in the embodiments of the present invention without departing from the spirit and scope of the concepts of the present invention.

[0009] The present invention will be better understood and various other objects and advantages will become apparent upon consideration of the following detailed description. Such description refers to the accompanying drawings.

Brief Description of the Drawings

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DETAILED DESCRIPTION OF THE INVENTION

[0039] Due to the following structures, features, and functions, the tricuspid valve prosthesis and its delivery system of the present invention can treat larger and more diverse anatomical structures of TR patients. Each provides advantages individually or in combination. The new prosthesis elements include a self-aligning gimbal, a self-filling three-dimensional junction sail, a coupler, a pre-curved prosthesis configuration (without using a tensioner system), and an automatic rotation mechanism for the junction sail.

[0040] First, referring to FIG. 1, a perspective view of the tricuspid valve prosthesis 100 of the present invention is shown. No assumed tensioner or anchor components are depicted in this figure. The nitinol IVC stent 102 is positioned in the IVC near the junction of the right atrium (RA) and the IVC. The stent functions on its own in the IVC and secures the tricuspid valve prosthesis during deployment. The coupler 104 includes a proximal portion 104a tethered to the IVC stent 102 via a nitinol or other medical grade wire 103 and a distal portion 104b connected to the gimbal 106. Next, the gimbal is connected to the junction sail 108.

[0041] The coupler / gimbal assembly provides for multi-axis rotation of the attachment seal relative to the coupler within the TV valve ring. The attachment seal itself includes three-dimensional shaped Nitinol wire frames 110a, 110b therein and is covered with a porous or semi-porous material such as fabric 112. The material can be selected from any of a number of porous, semi-porous, and even non-porous materials such as fabric, polymer barrier, polyurethane foam (PU), reticulated polyurethane, polytetrafluoroethylene (PTFE). Polyester suture thread is used to attach the attachment seal to the gimbal. When deployed, the attachment seal extends at least partially generally centrally towards the TV. This provides a natural TV valve tip mating surface sufficient to resolve the valve attachment gap.

[0042] The isometric view of FIG. 2 shows that the distal portion 104b of the coupler 104 includes a through hole 118 axially aligned with the base 114 and arms 120a, 120b for passing an axis or pin (see FIGS. 5A - 5C) to connect the distal portion 104b to the proximal portion 104a of the coupler 104 in an integral yoke 116. The coupler base 114 includes a cylindrically frustoconical passageway 122 disposed longitudinally centrally between the arms 120a, 120b. The platform 124 between the bases of the arms includes a first elliptical well or recess 126 with sidewalls 128 and has a center 130 aligned with the central axis of the cylindrically frustoconical passageway. A deeper second elliptical recess 132 also has a center on the central axis 123 of the cylindrically frustoconical passageway and includes a major axis 134 perpendicular to the major axis 136 of the first elliptical recess between its vertices.

[0043] The gimbal 106 includes a cylindrical shaft 140 having a central axis 141 that coincides with the central axis 123 of the cylindrical frustum passage 122 of the coupler distal base 114 when the shaft is inserted into the cylindrical frustum passage, and the clearance between the shaft and the cylindrical frustum passage is such that the shaft can pivot in an arc of about 20-50 degrees across the cylindrical frustum passage axis (see FIG. 2C). In embodiments, the pivot may be a substantially symmetric swing, but it need not be, and in some embodiments, the swing may be adjusted for a particular patient and occur in an asymmetric range of motion. The movement of the gimbal shaft that aids the self-aligning function of the engagement sail is further enabled by a gimbal head 142 disposed in the first elliptical recess 126 and having a generally planar oval top 144, and in embodiments, may include a hemispherical ball 146 disposed between the shaft 140 and the top 144. The apex of the oval head has a clearance from the sidewall of the first oval recess, and the head can also rotate about 10-40 degrees within the cylindrical frustum passage. In summary, it will be appreciated that the gimbal can perform both pivoting and rotation with respect to the coupler.

[0044] The distal end 148 of the gimbal shaft 140 includes a male thread 150 into which a gimbal wing nut 152 is threadably attached to secure the end of the nitinol wire within the gimbal. More specifically, in embodiments, the wires of the nitinol frame pass through slots or holes 140a in the gimbal shaft, are wrapped around a circumferential channel, and when these are threadably attached to the gimbal shaft, are captured by the gimbal nut. In embodiments, suture thread may be used to secure materials that cover, embed, or surround the nitinol wire frame. The wings 154 of the gimbal wing nut include holes 156 for more easily attaching the engagement sail fabric to the gimbal assembly (via suture thread).

[0045] Constructed as such, as shown in FIGS. 2B and 2C, the gimbal shaft rotates within the cylindrical frustum passage of the coupler, and the head rotates within the recess of the coupler platform.

[0046] The joining device of the present invention (more specifically, the structure and components of the joining sail itself) provides a three-dimensional surface for the natural valve leaflets to contact (join) so that blood does not flow into the RA during RV contraction. Conventional devices had a substantially planar configuration and joining surfaces and could effectively expand the natural valve leaflets, but in many cases these devices were insufficient to resolve the joining gap and thus insufficient to reduce TR.

[0047] Figures 3A - 3E are very schematic views showing the contact area of the coupler 104 and the gimbal 106 when the system is drawn into the delivery sheath 101. The distal portion 104b of the coupler rotates about an axis or pin 119 disposed through a hole 118 in a yoke 116 that connects the distal portion of the coupler and the proximal portion 104a of the coupler, so that when the components are drawn into the sheath for delivery, the gimbal shaft is axially aligned with the axis of the delivery sheath 101 (Figures 3A, 3C(a), and 3D(a)). When removed from the sheath during delivery, the distal portion 104b of the coupler rotates into an angled configuration, possibly with the aid of a pusher bar manipulated by the physician (Figures 3B, 3C(b), and 3D(b)).

[0048] This operation is further illustrated in FIGS. 4A - 4C, in which, in an embodiment, when pushed into the delivery sheath (FIG. 4A), the nitinol wire torsion spring 125 is captured inside the cylindrical sheath wall and moved into a bent configuration, whereby it can be seen that tension is applied. When removed from the sheath, the spring 125 straightens, applying an angular force to the distal portion 104b, rotating it about the axis 119 and forcing it into an angled relationship with respect to the proximal portion 104a, such that when delivered, the gimbal axis 141 tilts laterally and downwardly, becoming substantially coaxial with the collection of junctions of the septum, posterior valve tip, and anterior valve tip joining lines. This automatic rotation mechanism of the coupler / gimbal / sail assembly promotes achieving an optimal orientation of the joining sail, with the upper portion of the joining sail preferably becoming parallel to the TV valve annulus. Thereby, the joining of the joining sail and the native valve tip is maximally ensured.

[0049] Next, looking at FIGS. 5A - 5C, several schematic views show the TV valve tip joining 501 in FIG. 5A, and the wide joining gap 502 and narrow joining gap 503 respectively, with the latter shown in FIGS. 5B, 5C.

[0050] In an embodiment, the nitinol wire of the joining sail can be pre - bent to better conform to the target TV. The stent comprises a pre - bent portion, but can also be configured without a tensioner and anchor system. Such an alternative configuration may be desirable to reduce the complexity of the procedure. It will be understood that multiple pre - bent variations are available for a physician to address the anatomical structure of a particular patient.

[0051] Figures 6A - 6C show the performance of a junctional seal deployed to fit several junctional scenarios 510, 511, 512 and the types of gaps shown in Figures 5B - 5C. For simplicity, the corresponding chordae tendineae and papillary muscles are not shown. Also, for the purposes of this disclosure, it is not necessary to characterize the junctional gap, as it is understood that the gap can extend completely or only partially across the anterior - septal, anterior - posterior, or septal - posterior junction lines. Whether the junctional gap is narrow or wide, it causes TR, regardless of whether it extends partially or completely across the junction line. Importantly, these figures also illustrate the changing configuration in which the junctional seal adapts and conforms to the junctional gap over several cardiac cycles, thereby creating a junctional surface along the native leaflets during the cardiac cycle. Figure 6A shows the shape of the junctional seal when first deployed, Figure 6B shows the shape at an initial stage of blood filling and clotting, and Figure 6C shows the final shape of the junctional seal configured to effectively fill the junctional gap and prevent TR after several cardiac cycles.

[0052] In an embodiment, the junction device includes the feature that upon deployment, a semi - porous or porous material, such as a fabric, textile, polymer barrier, polyurethane foam (PU), reticulated polyurethane, polytetrafluoroethylene (PTFE), etc., can be used to mold the junctional seal in three dimensions. Depending on the material of the junctional seal, blood can fill the interior of the three - dimensional junctional seal while obtaining the shape of the native leaflets and any gaps between the leaflets without the need to use a balloon. This also results in an internal expansion structure that can be loaded by the physician into the sheath of the delivery system.

[0053] The figures of 6A - 6C illustrate how the junctional seal changes shape over time to create a junctional surface along the native leaflets. The blood - filling function of the three - dimensional junctional seal occurs naturally during the cardiac cycle due to the pressure difference between the RA and RV, respectively. Initially, the pressure inside the junctional seal (Sp) is equal to the right atrial pressure (RAp) because it is deployed inside the right atrium (RA).

[0054] At t = 0, 510, when the anastomotic seal crosses the TV valve annulus and is positioned between the native leaflets, during systole RVp > RAp, so it is exposed to a pressure difference. During diastole, the pressure becomes more uniform and the influence on the pressure of the anastomotic seal is minimized. Note that during the cardiac cycle, the pressure difference penetrates the structure of the anastomotic seal.

[0055] At t = 1, 511, since blood flows from high pressure to low pressure, the porous anastomotic seal material allows non - coagulated blood and other blood components to enter the interior of the anastomotic seal and fill it slowly. Note that as the anastomotic seal fills, the anastomotic gap also gradually closes, and as a result, the pressure difference increases, which in turn causes the anastomotic seal to be filled more fully.

[0056] In an embodiment, a variable porous material structure can be used to adjust the pressure changes, the resulting blood volume, and the shape of the anastomotic seal. To control the final shape of the anastomotic seal and prevent it from becoming a non - productive floating ball above the leaflets, various methods are available, such as varying the porosity according to the depth of insertion.

[0057] At t = 2, 512, the interior of the anastomotic seal is filled with blood and since it is outside the irregular blood flow, the blood is coagulating inside the anastomotic seal. When the blood coagulates, even if a pressure difference remains, the coagulated blood cannot flow back through the porous material of the anastomotic seal, effectively creating a three - dimensional anastomotic seal shape that conforms to the shape of the native leaflets.

[0058] Ultimately, due to the endothelialization of the surface of the anastomotic seal, the coagulated blood is sealed inside the anastomotic seal, although it can change shape over time in response to the changing valve annulus.

[0059] Note that the joining range of the joining seal is determined by the degree of existing TR and the size of the joining gap. Since the cross-section of the joining seal gradually transitions from a substantially straight shape at the bottom to a three-dimensional oval shape at the top, the ability to treat anatomically different wide types of TR is obtained depending on the amount inserted across the valve annulus. Thus, the lower planar portion of the joining seal effectively brings about the dilation of the native valve leaflets, while the upper portion fills the TR gap. Therefore, based on the patient's anatomical structure and insertion depth, the major axis of the joining seal can be at various angles (not necessarily perpendicular) to the TV valve annulus plane, and yet a reduction in TR is still achieved. Various configurations of the joining seals 701 to 705 are shown in FIGS. 7A to 7F.

[0060] Referring to FIGS. 8A to 8C, the joining seal 801 can include a lower planar portion 802 that can include one or more pleats or branches 803, thereby forming individual lobe portions 801a, 801b and facilitating the bending of the joining seal around the periphery of the curved joining connection, which can result in an improvement in the joining around the curve. These are shown in FIGS. 8A to 8C.

[0061] FIG. 9 is a schematic diagram showing the degree of freedom by which a physician can control the positioning of the joining seal inside the TV valve annulus via the movement of the handle of the delivery system, showing the relative movement of the gimbal to facilitate an improvement in the joining.

[0062] Next, referring to FIG. 10, in an alternative embodiment of the joining device 200 of the present invention, the device includes a delivery system that is structurally and operationally connected and that facilitates the accurate positioning and placement of the joining device during installation and deployment. The following description includes an explanation of the TV prosthesis itself, which also includes a joining sail 108 that is positioned and placed by a dedicated joining device delivery system. The joining sail 108, its porous / semi-porous material cover 112, and its nitinol frames 110a, 110b remain substantially the same as in the previous embodiment and thus maintain the same reference numerals. Other elements, such as couplers and gimbals, are substantially the same but have been modified for use with the novel delivery and placement system and are thus given new numbers along with the newly described elements and functions.

[0063] Next, referring again to FIG. 10, in alternative embodiment 200, it can be seen that the joining sail 108 includes nitinol wires 110a, 110b of an internal three-dimensional shape that are at least partially surrounded and covered by various porous and non-porous materials 112. The joining sail includes a proximal intermediate section 106 between the nitinol wires. The joining sail 100 extends somewhat into the center of the TV and provides a joining surface for the native TV valve tip.

[0064] At the proximal intermediate portion of the joining sail, an alternative embodiment of the gimbal / coupler subassembly 220 connects the joining sail 108 to the nitinol steering tube subassembly 300. The gimbal 222 connects the coupler 224 to the joining sail 108, resulting in a multi-axial rotation of the joining sail with respect to the coupler 224 inside the TV valve annulus. The coupler 224 includes a proximal portion 224a and a distal portion 224b and captures the gimbal such that the gimbal includes degrees of freedom via rotational and swiveling motions with respect to the coupler. The coupler 224 is connected to the distal end 300a of the steering tube with a pin 300b. Also, the nitinol wire frame 102 of the joining sail 108 is connected to the distal end of the gimbal shaft 222a of the gimbal by a coupling clamp 222b.

[0065] The steering tube 300 and associated tensioner rod subassembly 500 are attached to the stent 400 and delivery system handle, providing multi-axis adjustable positioning of the junction sail 108. Tensioning and / or rotating the steering tube subassembly within the stent 400 aligns the junction sail with the positioning and TV valve annulus, and the TV valve annulus engages the native TV valve leaflets to treat various anatomical structures. The IVC stent 400 is composed of nitinol, positioned in the IVC near the junction of the right atrium (RA) and the IVC, and secures the tricuspid valve prosthesis in the IVC. Note that the antithrombotic cover of the steering tube 300 is not shown.

[0066] In the TR patient population, there are many anatomical variations in addition to basic dimensions such as the IVC diameter and the size of the TV valve annulus. The orientation of the IVC ostium (IVC ostium plane), the distance to the TV valve annulus, and the orientation of the TV valve annulus (TV valve annulus plane) pose additional challenges in positioning the junction sail. However, the orientation and position of the junction sail in the three-dimensional space of the RA and TV valve annulus are extremely important for successful correction of TR. Therefore, additional prosthesis and delivery system functions are required to ensure that the junction prosthesis and delivery system of the present invention can treat the various anatomical structures of the TR patient population.

[0067] The following novel systems provide the required functions, along with features and functions that enable the junction prosthesis and delivery system of the present invention to treat a more diverse range of TR patient anatomical structures. Each function provides advantages individually or in combination. In particular, some novel aspects of the junction sail 100, gimbal 222, and coupler 224 are the same as those of the inventors of the present invention and are disclosed in a co-pending international patent application filed simultaneously, which is entitled "Junction Device" and is incorporated herein by reference in its entirety.

[0068] The elements of the prosthesis and delivery system included in this disclosure mainly consist of: (1) a novel gimbal design manufactured from medical - suitable materials such as polyetheretherketone (PEEK), stainless steel, titanium, etc.; (2) a steering tube (adjustable in multiple axes and manufactured from materials such as nitinol, PEEK, etc.); (3) a stent design for the steering tube attachment, also manufactured from the same materials; and (4) a tension rod sub - assembly manufactured from PEEK, stainless steel, titanium, polyimide, etc.

[0069] The gimbal 222 connects the coupler 224 to the junction sail 108, enabling the junction sail to move relative to the coupler in multiple axes. The ability of the junction sail to self - orient inside the TV valve annulus ensures that the junction sail does not collide with the native valve leaflets, thereby causing an increase in TR. Instead, it ensures that the junction sail self - aligns to the junction connection to strengthen the connection of the native valve leaflets. To illustrate the design elements, some figures of the gimbal and coupler assembly are shown in FIGS. 11A - 11C. Porous and non - porous cover materials that include the intermediate portion between nitinol wires, or porous and non - porous covers between the outer layer and nitinol wires, are not shown.

[0070] FIGS. 11A - 11C are perspective views showing the gimbal 222 including nitinol wires 110a, 110b and the steering tube 300 attached to the coupler 224. The exploded view of FIG. 11B shows the various components of the assembly including the gimbal 222 and the coupler 224. Note the angled tab 301 at the distal end 301b of the nitinol steering tube 300. While wrapping the prosthesis (junction sail), the tab 301 is generally aligned with the axis of the steering tube, but when the sheath is removed, it bends inward to the position shown. This is due to the springiness of the tab material.

[0071] The cross-sectional view of FIG. 11C illustrates the attachment of the coupler 224 to the steering tube 300 via the pin 300a. Note that the gimbals are housed within and captured by the proximal and distal portions of the couplers 224a and 224b respectively and extend therethrough.

[0072] The purpose of the steering tube 300 is the positioning of the engagement seal 108 relative to the TV valve ring. The multi-axis adjustment capabilities, bending in multiple planes, and rotation with respect to the stent of this design collectively enable fine-tuning of the position of the engagement seal to match the patient's anatomy.

[0073] The schematic views of FIGS. 12A - 12C illustrate multiple orientations of one steering system at various amounts of bending and rotation. Note that the bending of the steering tube is the result of the rotation of a threaded insert (which interacts with the tension rod subassembly) such that the tension in the tension member, which effectively shortens one side (the side where material is removed) of the steering tube to create curvature, is increased. The material of the steering tube is typically nitinol, although other materials (such as PEEK, stainless steel, etc.) are also suitable.

[0074] One configuration of the steering system subassembly is shown assembled in FIG. 13. The illustrations of FIGS. 15 and 17 are cross-sectional views of the steering configuration of FIG. 13 and further include details of the tension rod subassembly coupled to the steering rod subassembly.

[0075] FIG. 14 is a top perspective view showing components including a steering system and a tension rod subassembly, and also in this figure, it illustrates how a tension member 501 (e.g., a suture, a thin cable or chain, a medical wire, etc.) is wound around a suture pin 502 (i.e., an anchor pin). When the threaded component 504 rotates to generate tension, almost no or no moment is transmitted to the tension member 501, and due to the axial load applied to the threaded component, there is no counter-torque for removing the sheath, so it should be noted that the tension member 501 is effectively fixed at a predetermined position.

[0076] The individual components and their respective functions of the multi-directional positioning and placement system particularly include, as described above, the novel steering tube 300. It is necessary to understand that based on the pattern at the time of cutting (and additional cross-through pins), bending can occur in several different directions. This can be determined according to the anatomical structure of the patient for a specific procedure and the requirements of the control system. The serrated collar 302 is fixed to the steering tube 300 using a cross-through pin 303, which provides a serrated edge at the inner / proximal end, and thereby fixes the rotational angle of the steering tube with respect to a serrated stent collar 304 having a serrated edge that meshes in combination with that of the serrated collar. Thereby, the bending direction is obtained via a tension member passing under the cross-through pin (see particularly FIGS. 15 and 17). The serrated stent collar 304 attaches the steering tube 300 to the stent 400 and allows the steering tube to rotate with respect to the stent.

[0077] The compression spring 306 causes the serrations of the serrated collar 302 to engage with the serrated distal (first) stent collar 304 and provides a spring force for manually rotating the steering tube with respect to the stent. In an embodiment, the compression spring 306 is inside the steering tube (not shown) and can provide a locking spring force.

[0078] Although the use of a serrated collar is shown, alternative embodiments include a collet that provides higher angular resolution, or an arrangement of cross pins and grooved collars. In alternative embodiments (not shown here), compression of the spring, rotation of the steering tube, and locking of the rotation angle by the handle control of the delivery system may be possible.

[0079] The ring collar 308 is also attached to the steering tube using a cross through pin 305 and resists the spring force of the compression spring 306. The proximal (second) stent collar 310 is attached to the steering tube and allows rotation and movement of the steering tube relative to the stent.

[0080] The tensioner rod subassembly 500 provides a secure connection between the prosthesis and the delivery system handle, transmits rotational (torque) force to the steering tube via the tensioner rod, thereby adjusting the tension against flexion of the steering tube.

[0081] The tension rod subassembly shown in FIGS. 15A - 15C is illustrated in three views: an isometric assembly view, an exploded perspective view, and a cross - sectional perspective view. The individual components shown and their respective functions include a stitching pin 502 (FIG. 15B) fixed to a threaded tensioner 504 and connected to 501. The components of the threaded tensioner 504 adjust the tension of the tension member when screwed into or out of the threaded insert 312, causing a bend in the steering tube 300. The beaded wire 506 is combined with the threaded tensioner 504 using a bead expansion 506a at the distal end of the beaded wire, which is captured in and between a formed recess 504a at the proximal end of the threaded tensioner surrounded by a tension collar 508 and a formed recess 510a at the distal end 510a of a tension interlock 510, providing an interface that locks in a predetermined position to provide a torqueable assembly while allowing the tension interlock 510 to be severed when moved from the threaded tensioner 504. The beaded wire is connected at its proximal end to a release button 604 of the delivery system. The tension collar 508 is mounted to cover the proximal end 504a of the threaded tensioner 504 and the distal end 510a of the tension interlock 510. The threaded tension interlock 510 is attached to a tension tube 514 and a torsion tube 514.

[0082] A radiopaque band 512 is attached over the tension tube 514, providing assistance for fluoroscopic imaging when evaluating the relative position of the threaded tensioner 504 inside the threaded insert 312. The tension tube 514 is attached to the tension interlock 510 and connected to an operator - controlled knob of the delivery system (not shown in these figures).

[0083] The individual components of the interlock assembly are shown side by side in FIG. 16. This illustration shows the components separately positioned, but the final assembly is essentially coaxial. Here too, the tension interlock 510 is rotated 180 degrees and illustrates the function of the end that captures the balled end 506a of the ball wire 506. As described above, the expanded spherical end of the ball wire 506 fits into a pocket at the end of the threaded tensioner 504, the tension interlock 510 is placed over the rounded end, and when the tensioner collar 508 covers all the components at the interface, the ball wire is fully captured. The threaded tensioner 504 and the tension interlock 510 both have "D"-shaped ends that, when joined together, are housed inside the tensioner collar 508. This interlock assembly provides an interface that locks in place and provides an assembly that can be torqued, and allows for cutting when the tension interlock 510 is moved away from the threaded tensioner 504.

[0084] This configuration has been described for a "ball wire captured in a pocket", but this is not limiting. Alternatives include L-shaped wire ends on both sides that fit into L-shaped pockets on both sides of the D-shaped end, or slots with holes at the ends of the L-shaped wire ends. In each alternative, a tensioner collar is required to restrain the joint until cutting is required.

[0085] Cross-sectional views of the steering system and the tension rod subassembly are shown in FIGS. 17 and 19. Note that the routing of the tension member (i.e., suture, wire, cable, chain, etc.) in this configuration passes under the intermediate point 518 from the distal end 516, reaches the proximal return 520, and returns to 516 along the same path. A typical assembly method involves routing the tension member inside a protective lubricating tube (i.e., FEP, PTFE, etc.) that wraps around the pin 520 while passing under the cross-through pin 518 and terminates at 516. The protective lubricating tube (not shown) prevents damage to the tension member by the inner edge of the steering tube 300 during flexion in a clinical environment or natural prosthesis movement. Additional cross-through pins can be distributed throughout the length of the steering tube to create additional pivot points. These pivot points, in combination with various laser cut patterns, result in multi-directional flexion of the steering tube.

[0086] The path of the tension member over / under or from one side to the opposite side of each cross-through pin can vary depending on the desired flexion. Additional guides for controlling the path of the tension member can be placed on the cross-through pins. Additional tension members can be connected to these cross-through pins, and coaxial or non-coaxial threaded inserts and a tension rod configuration (not shown) can be used to apply various amounts of force to various sections of the steering tube.

[0087] When a threaded insert is attached to the steering tube, the steering tube has a "T"-shaped feature that interacts with the threaded insert, providing a fixation without the use of fasteners or adhesives.

[0088] As can be seen from FIGS. 17-18, the stent 400 is configured to be attached to the steering tube. The serrated stent collars 304 and 310 each include two pins that pass through the collar and enter the aligned holes 402, 404 (see FIG. 18) of the stent for attaching the steering tube to the stent. The stent strut gap between the holes allows the integral stent collar to be firmly captured by the stent struts.

[0089] A single coaxial tension rod subassembly is shown in FIG. 19. As can be surmised thus far, the purpose of the tension rod subassembly is to adjust the flexion of the steering tube, fix the amount of tension once positioned, and then remove it from the prosthesis upon completion of the implantation procedure. The tension rod subassembly is shown in detail in each of FIGS. 15A-17, and FIGS. 19-20. The connection between the steering system subassembly and the tension rod subassembly is achieved via a threaded insert 312 that is attached to the steering tube and threadedly connected to a threaded tensioner 504.

[0090] The proximal end of the delivery system associated with the tension rod subassembly is operatively coupled to a conventional endoscopic control handle having a tension knob, a release knob, a guide wire lumen and luer lock, a plurality of dials for rotating and / or bending the steering tube, a lever for locking or unlocking the position of the joining device, and other actuating mechanisms for controlling the multi-directional positioning and placement of the joining device.

[0091] The main components of the delivery system control handle are illustrated in FIGS. 21 through 22C. Referring to each and all of these figures, at the proximal end of the system is a prosthetic delivery system handle 600 that provides multiple functions during the preparation and implantation of the tricuspid valve prosthesis and provides a controlled implantation that allows for retrieval if necessary. The control handle includes a tension knob 602, a release knob 604, and a guide wire lumen and luer lock 606. The flush port 608 allows the system to be flushed with heparinized saline to remove all air from the inner catheter and prosthesis. The sheath dial 610 is operatively connected to the delivery sheath and, when rotated, retracts the outer sheath and slowly exposes the engagement prosthesis. The heparinized saline drip line 612 facilitates the prevention of clotting of the adjustment mechanism during prosthesis delivery. The stent release button 614 prevents accidental release of the prosthesis until it is pushed by preventing the outer sheath from being fully retracted. The cylindrical passageway 620 of the control handle routes the tension tab 514 to an effective connection with the tension dial knob 602 that adjusts the amount of tension applied to the prosthesis during rotation, and the release knob button 604 disconnects the delivery system from the prosthesis. The cylindrical passageway 622 receives the cardiac guide wire that passes through the handle and exits at the luer lock 606 at the proximal end of the handle.

[0092] In FIGS. 22A through 22C, note the delivery system handle 600, tension knob 602, release knob 604, and guide wire lumen and luer lock 606. The cross-sectional view (FIG. 22B) illustrates the structural and operational relationships of the components and the mechanism of the compression spring inside the tension knob 602 that applies spring force to maintain the connection of the interlock assembly. A side-set screw 605 is included for safety to ensure that the two components remain connected. When ready to remove, loosen the side-set screw and pull in the tension knob 602 to remove from the prosthesis.

[0093] The enlarged view (Figure 22C) illustrates a visual indicator 607 of a white ring that presents a reference point of the applied tension. Additional delivery system handle configurations (not shown) include a plurality of dials for rotating and / or bending the steering tube, a lever for locking or unlocking the position of the joining device, and other control and actuation mechanisms for multi-directional movement of the joining device, ensuring very accurate positioning and placement on TV.

[0094] The implantation procedure using the joining device and its delivery system is similar to other transcatheter procedures using fluoroscopy and echo visualization and includes the following steps.

[0095] First, access the femoral vein and perform an anatomical evaluation and a TVR evaluation. Next, prepare the joining prosthesis and place it in the sheath, and confirm the preparation of the system. Then, connect a heparinized saline pressure bag to the side stop cock of the delivery system handle and appropriately set the bag pressure to ensure a slight flow from the sheath tip. Load the prosthesis into the delivery system. Next, the physician / operator advances the joining prosthesis and its control mechanism from the access site to the right atrium via a guide wire using image guidance. Next, the physician / operator observes the radiopaque nose cone and the outer sheath tip marker using fluoroscopy.

[0096] To deploy the joining prosthesis, fix the delivery handle to the surface, rotate the sheath dial clockwise so that the tip of the outer sheath retracts, gradually exposing the sail into the right atrium while the outer sheath passes through the introducer sheath. When the joining sail and the steering tube are completely out of the sheath, rotation of the sheath dial stops. At this point, an evaluation is made of how the position of the joining sail interacts with the TV valve annulus and the native valve leaflets.

[0097] To obtain optimal results, the sail is repositioned, as necessary, by one of the following: (1) advancing, retracting, or rotating the entire prosthesis system; (2) further rotating the sheath dial clockwise to further expose the prosthesis; or (3) rotating the tension knob counterclockwise to bend the distal portion of the stent, taking great care to ensure that only the stent is exposed.

[0098] Next, changes in regurgitation and valve function can be evaluated by ultrasound imaging (ICE, TTE).

[0099] Deployment of the prosthesis: To deploy the prosthesis, the physician / operator carefully rotates the sheath dial 610 clockwise and stops while maintaining the position of the distal end of the stent in the IVC to expose the stent. Note that the stent remains constrained by the sheath at the proximal end, but is juxtaposed in the IVC while it expands.

[0100] Using the hex wrench provided in the sterilization preparation materials, the operator carefully loosens the set screw 605 that connects the tension knob 602 and the release button 604. To remove the delivery system from the stent, the operator gently presses / pulls with the tension knob and release button, pulling with the tension knob and pushing with the release button. Observe the results carefully and confirm removal by carefully pulling the tension knob and release button from the handle 600.

[0101] To fully remove the stent from the IVC, keep the release button on the delivery system handle pressed and then turn the sheath dial clockwise to fully expand the stent in the IVC (note that the order of some steps may be reversed depending on the situation). Next, the operator must slowly advance / retract the delivery system to confirm that the delivery system is completely disengaged from the prosthesis.

[0102] Next, rotate the sheath dial (counterclockwise) to advance the sheath to the nose cone.

[0103] Finally, the guide wire is removed before the stent is removed, which is removed from the currently implanted and positioned prosthesis system.

[0104] The foregoing description is directed to preferred embodiments of the invention, including the best mode contemplated by the inventors for carrying out the invention presently under consideration. However, these do not purport to cover all possible alternative embodiments, whether found in substantially equivalent alternative structures, substantially equivalent alternative acts, or both, nor are they intended to begin to do so. The embodiments are rather presented and described for illustrative purposes, but it will be understood by those skilled in the art that it is not desired to limit the invention to the exact structures, dimensional relationships, and acts shown and described. Various modifications, alternative structures, changes, and equivalents can be readily conceived of by those skilled in the art and may be used as appropriate without departing from the true spirit and scope of the invention. Such changes may include alternative materials, components, structural arrangements, sizes, shapes, forms, functions, operating characteristics, alternative orders of method steps, and the like. Accordingly, the above description and illustration should not be construed as limiting the scope of the invention as defined by the appended claims.

Claims

**Claim 1** A tricuspid valve prosthesis for treating tricuspid valve regurgitation (TVR), comprising: A stent configured to be implanted in the inferior vena cava (IVC) near its junction with the right atrium (RA); A coupler and gimbal assembly tethered to the stent; and A junction sail having a wire frame connected to the coupler and gimbal assembly and housed inside a material cover, the junction sail being configured for percutaneous delivery to the RA for deployment inside the tricuspid valve (TV) annulus; The tricuspid valve prosthesis, wherein when the stent is implanted in the IVC and the tethered junction sail is deployed inside the TV annulus, the junction sail material absorbs and holds blood, the blood coagulates inside the junction sail, and over a plurality of cardiac cycles, the junction sail is shaped by the pressure difference, blood flow, and physical engagement with the native valve leaflets between the RA and the right ventricle to provide a mating surface to the native valve leaflets and reduce the size of the mating gap, thereby forming a three-dimensional shape that reduces TVR. **Claim 2** The tricuspid valve prosthesis according to claim 1, wherein the tethering is by wire. **Claim 3** The tricuspid valve prosthesis according to claim 1, wherein the stent is made of nitinol. **Claim 4** The tricuspid valve prosthesis according to claim 1, wherein the wire frame is made of nitinol wire. **Claim 5** The tricuspid valve prosthesis according to claim 4, wherein the wire frame is configured to have a curvature that matches the native valve leaflets before implantation. **Claim 6** The tricuspid valve prosthesis according to claim 1, wherein the material cover is porous. **Claim 7** The tricuspid valve prosthesis according to claim 1, wherein the material cover is non-porous. **Claim 8** The tricuspid valve prosthesis according to claim 1, wherein the coupler and gimbal assembly includes a coupler having a proximal portion tethered to the stent, a distal portion pivotally connected to the proximal portion and having a cylindrical through-passage, a gimbal having a head captured between the proximal and distal portions of the coupler, and a cylindrical shaft inserted into the through-passage, the shaft having a distal end configured to be attached to the wire frame of the junction sail. **Claim 9** The head of the gimbal and the distal portion of the coupler of claim 8 are configured such that the gimbal can rotate about its longitudinal axis and pivot with respect to the coupler. The tricuspid valve prosthesis according to claim 8.

10. The coupler and gimbal assembly of claim 9 are configured to provide multi-axis rotation of the bonding seal with respect to the coupler within the TV valve annulus. The tricuspid valve prosthesis according to claim 9.

11. The bonding seal has a generally flat side surface, upper surface, and lower edge, and is configured to automatically rotate with respect to the coupler upon deployment, with the upper portion being parallel to the TV valve annulus and maximizing the engagement with the native valve leaflets. The tricuspid valve prosthesis according to claim 10.

12. The cylindrical shaft of the gimbal has a mounting structure for connecting the wire frame at its distal end. The tricuspid valve prosthesis according to claim 10.

13. The mounting structure includes a male threaded portion at the distal end of the cylindrical shaft and a wing nut that threads onto the male threaded portion, and the wires of the wire frame are captured and fixed to the cylindrical shaft by the wing nut. The tricuspid valve prosthesis according to claim 12.

14. The gimbal includes a hemispherical ball that engages the surface of the distal portion of the coupler under the head, thereby facilitating a pivoting motion with respect to the distal portion of the coupler. The tricuspid valve prosthesis according to claim 9.

15. The tricuspid valve prosthesis according to claim 1 further includes a torsion spring disposed between the proximal and distal portions of the coupler, which biases the proximal and distal portions in an angular direction with respect to each other when deployed from the delivery sheath.

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