Mitral valve leaflet tethering

Abstract

The present disclosure includes devices and techniques for threading one or more catheters to the apex or base of the right ventricle by transfemoral vein access to the right ventricle. The catheter can be passed through to turn upward, directed towards the mitral valve, by puncturing the ventricular septum into the left ventricle through the ventricular side or right side of the heart. From this entry point in the left ventricle, flail mitral valve leaflets can be sutured and tethered, pulled back into place, and re-attached with grounding anchors in the right ventricle, or embedded in the septal wall. The ventricular septal crossing technique may include passing a coaxial conduit through a first access conduit, where the first access conduit may act as a guide to direct an inner or second coaxial conduit toward a flail mitral valve leaflet.

Description

[0001] This application is a divisional application of the invention application filed on December 30, 2016, with application number CN202310432127.X and titled "Mitral valve leaflet tethering". Technical Field

[0002] This disclosure relates generally to cardiac treatment devices and techniques, and particularly to methods and devices for mitral valve repair. Background Technology

[0003] The heart consists of four valves that allow blood to flow in one direction through the four chambers of the heart. These four valves are the tricuspid valve, mitral valve, pulmonary valve, and aortic valve. The four chambers are the right atrium and left atrium (upper chambers) and the right ventricle and left ventricle (lower chambers).

[0004] The mitral valve is formed by two leaflets, called the anterior and posterior leaflets, which open and close in response to the pressure exerted on the leaflets by the heart's pumping action. Several problems can develop or occur with the mitral valve. These problems include mitral regurgitation (MR), in which the mitral valve leaflets do not close properly, potentially leading to mitral valve leakage. Severe mitral regurgitation can adversely affect heart function and impair a patient's quality of life and lifespan. Several techniques are designed to correct mitral regurgitation, including valve replacement, chordae tendineae shortening or replacement, and mitral valve annulus repair, also known as annulusoplasty.

[0005] Existing techniques for correcting mitral regurgitation involve repairing the mitral valve via open-heart surgery while the patient's heart has stopped beating and the patient is on cardiopulmonary bypass. This technique is highly invasive and carries inherent risks. There is a need to provide a less invasive surgical procedure for repairing the mitral valve. Summary of the Invention

[0006] One embodiment disclosed herein includes a method for repairing a patient's mitral valve, the method comprising inserting a catheter extending through the venous side or right side of the heart into the right ventricle of the patient's heart to access the left ventricle, and fixing the mitral valve leaflets with the catheter.

[0007] Another embodiment disclosed herein is a chordae tendineae replacement system, which may include a catheter and a chordae tendineae replacement implant. The catheter may have an elongated, flexible tubular body having a proximal end and a distal end. The catheter may be configured to enter the right ventricle via a blood vessel and the left ventricle via the interventricular septum. The chordae tendineae replacement implant may be deployably carried by the catheter. The chordae tendineae replacement implant may include an elongated body having a proximal end with a proximal tissue anchor and a distal end with a mitral valve leaflet attachment anchor.

[0008] Another embodiment disclosed herein is a method for repairing the mitral valve, which includes inserting a catheter into the right ventricle via a blood vessel, extending the catheter through the interventricular septum and into the left ventricle, and deploying a chordae tendineae replacement implant using the catheter. Attached Figure Description

[0009] Figure 1AA The normal mitral valve leaflet junction in the left ventricle is shown, including the chordae tendineae appendage extending from the free edge of the mitral valve leaflet to the papillary muscle.

[0010] Figure 1A The ruptured chordae tendineae are shown.

[0011] Figure 1 The technique for guiding one or more catheters to the apex or base of the right ventricle via the femoral vein is shown.

[0012] Figure 2 The image shows a catheter inserted into the interventricular septum wall via the venous side or right side of the heart to enter the left ventricle.

[0013] Figure 3 The first and second ducts are shown, which can be manipulated to position the distal end, thereby capturing the edge of the mitral valve leaflet.

[0014] Figure 4 A magnet is shown that can be used to position the ends of two catheters relative to each other.

[0015] Figure 4A The diagram shows a suture loop that passes through the leaflets of the mitral valve, is tethered back through the inferior duct, and is attached to an anchor at the apex or ventricular septum.

[0016] Figure 5 The grounding plug is shown.

[0017] Figure 5A The internal anchor within the tissue wall or interventricular septum tissue separating the left and right ventricles is shown.

[0018] Figure 5AA The spacer anchor is shown.

[0019] Figure 5B Examples of internal anchors and apex anchors are shown.

[0020] Figure 6 The grounding anchor located inside the heart is shown.

[0021] Figure 7 A spiral anchor is shown.

[0022] Figure 8 The pathway originating from the jugular vein also provides access to the vena cava and right ventricle, and / or access to the left atrium via transseptal puncture. Detailed Implementation

[0023] The normal mitral valve leaflet 10 junction in the left ventricle includes the chordae tendineae 12 extending from the free edge of the mitral valve leaflet 10 to the papillary muscle 14, such as... Figure 1AA As shown.

[0024] The flail leaflets can be surgically repaired using sutures by reattaching them to the papillary muscle. Figure 1A Repair and reconnection of the ruptured chordae tendineae (7) shown. Another technique is transapical reconnection of flail leaflets, similar to the technique developed by a company called NeoChord.

[0025] A different technique involves accessing the right ventricle 16 via the femoral vein 18, and guiding one or more catheters 20 to the apex or base of the right ventricle 16, such as... Figure 1 As shown. The inlet will begin from the femoral vein 18 in the groin, ascend through the inferior vena cava into the right atrium 24, pass through the tricuspid valve 22 to reach the bottom of the right ventricle 16. It punctures the interventricular septum 19 via the venous side or right side of the heart to enter the left ventricle 26. The catheter 20 can pass through and bend upwards towards the mitral valve 28, as shown. Figure 2 As shown. From this entry point in the left ventricle 26, the flail-shaped mitral valve leaflet can be sutured and tethered, pulled back into place, and reattached with a grounding anchor in the right ventricle 16, or the anchor can be embedded in the septal wall. The septal wall traversal technique may include a coaxial catheter 30 passing through a first entry catheter 20, wherein the first entry catheter 20 can act as a guide to direct an internal or second coaxial catheter 30 toward the flail-shaped mitral valve leaflet. Figure 3 As shown, both the first catheter 20 and the second catheter 30 can be manipulated to position the distal end to capture the edge of the mitral valve leaflet. A needle can be passed through to guide a suture through the mitral valve leaflet to reattach the leaflet to the lower chamber of the heart, into or across the septal wall and anchored in the right ventricle. Passing a tether through the mitral valve leaflet and through the second internal catheter 30 back to the grounding anchor, the leaflet will be pulled into position, replicating any chordae tendineae that may have failed or broken. The attachment of the new suture to the grounding anchor can be achieved by knotting, sliding a one-way stop, or other means to engage the anchor and suture together. Single-line attachment or multiple-line attachment will allow the load to be distributed or pulled in different force vectors, thus moving the grounding point of the mitral valve leaflet in different directions. Figure 3As shown, secondary atrial access can be achieved via the venous system through transseptal puncture to reach above the mitral valve, to deliver additional catheter 32 into the left atrium for positioning above the flail leaflets. Achieving secondary fixation of the leaflets from both above and below will allow for accurate positioning and suture attachment within the leaflet margins under echo- and fluorescein fluoroscopy. Magnets 36 and 34 may be present at the ends of each catheter to position the ends of each catheter 30 and 32 relative to each other, as shown. Figure 4 As shown. Magnets 36 and 34 may have through holes or a central lumen to longitudinally transfer silk, sutures 43, or other items from one end to the other. The suture loop 41 will pass through the mitral valve leaflet 27, be tethered back through the inferior duct 30, and be attached to an anchor at the apex or ventricular septum, as shown. Figure 4A As shown.

[0026] The grounding plug or anchor 40 can be similar to the Amplatz device used for closing ASD, or similar to another device for distributing force over a larger area that distributes the load across a larger surface area within the right ventricle or interventricular septum, such as... Figure 5 As shown. Another way to secure the suture in the right ventricle is to attach the suture to a swab (finger-release cotton) 73 or other pad to distribute the load within the right ventricle. An alternative technique is to embed the internal anchor 42 within the tissue wall or interventricular septum separating the left and right ventricles, such as... Figure 5A As shown. Figure 5B and 5AA The internal anchor 50 can be delivered from above or from the left atrium, through the septal pathway and across the mitral valve leaflets to attach the mitral valve leaflets to the suture 43 and into the septal wall between the right and left ventricles, thereby securing it to an internal structure such as the anchor to prevent movement during suture tightening. Figure 5A As shown, the internal anchor may include a barb 80 and a suture holder 82. It may also be advantageous to extend a portion of the anchor into the left atrium away from the septal wall to position the tangent point directly below the attachment point of the mitral valve leaflet. This will provide a straight line to both the superior and inferior attachment points without torque or moment around the septal wall inlet and without interfering with any other chordae tendineae structures or papillary muscles. The strain relief section at the anchor exit can also prevent suture micro-vibration wear caused by areas where suture cyclic loading may be a stress concentration zone. Figure 7 As shown, spiral anchor 52 (see Figure 5B It can also be delivered from above via a septal pathway, entering the apex of the heart or myocardial tissue through the mitral valve. Coil 55 will allow the contact point to connect to the suture, which in turn connects to the mitral valve leaflets. Multiple connection points can also be added for additional support or tethering of additional ruptured chordae tendineae. Secondary adjustments can also be made after implantation by re-tethering the suture through wrapping, re-knotting, or pulling.

[0027] A guidewire 70, approximately 0.035 inches in diameter and 180 cm in length, can be used to access the femoral vein. (Example:) Figure 8 As shown, a guide sheath can follow to provide a catheter for the insertion and exit of additional catheters into and out of the femoral vein. The diameter of catheter 72 can be approximately 10 to 24 Frenchies, and the guide can be pushed into the femoral vein with a dilator to guide the distal end without damaging the vessel. The length of catheter 72 can be approximately 100 cm. Advancing the device delivery catheter along guidewire 72 through the guide sheath can be achieved using a radiopaque device for tracking the guidewire, guide sheath, and delivery catheter via real-time X-ray or fluoroscopy. Passing through the inferior vena cava and through the tricuspid valve into the right atrium, the catheter can follow the guidewire or be actively shaped or bent via a pull wire or shaping system through a deflectable catheter at the handle. Injected contrast dye into the heart can provide a route map of the structural items within the heart. Aiming or manipulating the catheter and guidewire to the apex of the right ventricle and passing a needle or puncture instrument from the right ventricle to the left ventricle will provide access from the femoral vein to the left ventricle into the mitral valve.

[0028] Alternatively, access to the left atrium can be achieved via the femoral artery in the groin through transseptal puncture, allowing advancement of the guidewire and catheter system in a similar manner as described above. This will allow the mitral valve leaflets to come into close contact, securing them and suturing them back into their correct positions. The upper catheter from the left atrium and the lower catheter from the left ventricle via the right ventricle can position and maintain the flail leaflets for suture puncture and tethering back into their correct positions to align with adjacent leaflets, thereby eliminating mitral regurgitation. A puncture needle and strain relief swab 75 can be used to pass through the suture 75 and distribute localized force at the leaflet attachment site, such as... Figure 6 As shown. Single or multiple passes through the leaflet will mimic normal chordae tendineae, thus providing normal leaflet movement. The suture material can be #4 or #5 PTFE, silk, or other materials commonly used for normal valve repair. The placement of the suture will allow normal left ventricular and mitral valve movement and freedom, as the suture will pass between the papillary muscles and attach at one end to the flail leaflet, while the other end, held in place by strain relief in the right ventricle, enters the right ventricle. Figure 8 As shown, the jugular vein access also provides access to the vena cava and right ventricle, and / or access to the left atrium via transseptal puncture. This jugular vein access eliminates the first 180-degree turn upwards along the femoral vein into the right ventricle, but it is not a routine access route for most interventional cardiologists.

[0029] The catheter will be constructed from common polymers including nylon, Teflon, polyurethane, and other readily available materials, with guidewire ports at both the proximal and distal ends. The desired catheter curve will be pre-set, fixed, or actively bent by varying forces transmitted via a pull cord or tube to bias in one or the other, thereby providing column compression on one side of the catheter relative to the other. Column and tube strength can be provided through embedded coiled wire, coiled wire braided with strip or circular filaments, laser-cut tubes, or skeleton structures to create the defined structure and / or curve required to achieve access. Variable stiffness and construction techniques are well-known in the industry to allow delivery of the desired specific pushability, stiffness, and curve. Internal and external coatings and surface treatments can facilitate relative movement between vessel walls and between the wire and other catheters. Tensioning can be provided by a pull cord extending from the distal end of the catheter to the proximal portion. This pull cord can be activated by converting a rotating bolt into a longitudinal force, thereby pulling the connection to the distal end of the catheter. The total length of the femoral vein catheter access will be approximately 100 cm, with a lumen to receive the guidewire for positioning within the body's vascular system. The total length of the internal jugular vein catheter will be approximately 60 cm. The two catheters will have a diameter of approximately 6-20 French and at least one lumen from the proximal and distal ends of the delivery system.

[0030] Access via the femoral vein allows the catheter to be inserted through the tricuspid valve and into the right ventricle. At the apex of the right ventricle, access to the left ventricle is achieved by advancing a needle or catheter through the septal wall. Passing a guidewire from the right ventricle to the left ventricle using a needle, ultrasound, or a heart-retrieving tool is the route and access path for mitral valve repair. Once the needle and / or guidewire can be advanced, additional tools such as catheters can be used to repair the mitral valve. The septal wall can be thicker than 1 cm, so the access port can be maintained by balloon dilation, a guide catheter, or an inlet cannula to allow tools and catheters to pass through during repair. Manipulated sheaths, catheters, or cannulas can allow easier access to specific areas of the mitral valve for repair. Once optimal positioning is achieved, rotation and / or angular adjustments can be fixed or locked in place. This can be achieved with a pre-shaped curved configuration where the catheter bends downwards through the tricuspid valve and across the interventricular septum, then upwards towards the mitral valve. This shape can be fixed or varied according to the patient's needs and anatomy. Guidewires approximately 0.035 inches in diameter and 180 to 300 centimeters in length will allow the catheter to be advanced and allow for the replacement of additional tools. Expandable dilators can be used to expand areas requiring a sealed passage or a larger diameter catheter. Catheter sizes range from approximately 6 Frenchies to approximately 24 Frenchies in diameter, with lengths ranging from 90 to 160 centimeters. These catheters can be constructed from common polymers, including nylon, polyurethane, polyethylene, or other similar polymers. Braided, coiled, or laser-cut tubing can be used in the catheter construction to better support the desired inner diameter, shape, or curve. These materials may also include stainless steel, nitinol, platinum, or MP35N metals suitable for catheter construction.

[0031] Nesting multiple catheters provides additional degrees of freedom for bending, movement, and translation. In one embodiment, a larger catheter (24 French diameter) leading to the apex of the right ventricle can be used to position a stable base from which an inner catheter (18 French diameter) is advanced through the interventricular septum, and a third catheter can be advanced through this catheter, with an inner diameter of approximately 14 French, to advance into the left ventricle, thus targeting the mitral valve. These catheters will allow for a variety of adjustments and angles for various anatomical structures. The ability to translate, rotate, and lock each of these catheters together or independently will provide a stable platform for delivering repair tools to the valve. The locking mechanism for each of these nested catheters can be achieved by using hydraulically altered diameter expansion, mechanical expansion through a rotating device that creates an eccentric locking, or longitudinal pulling that creates a diameter difference between the catheters. This push-pull translation can force the catheters to wrinkle, thereby creating a larger bulge within one catheter.

[0032] Furthermore, push-pull lines can force catheters to form predetermined shapes and curves in one or more planes. By laser-cutting a specific pattern into the inner frame of the catheter, the length of one side of the catheter is reduced by the pull line while the cylindrical shape of the catheter collapses, creating a shape determined by the laser-cut elements inside the catheter. As an example, a slot can be cut on one side of the tube, and a tension line can be attached to the distal end of the tube. As tension is applied to the line, the collapse of the slotted side of the tube will cause bending or biasing of the tubular element. These slots can also be complex shapes to lock the rotation angle into a predetermined shape. This complex shape can be a V-shape, a beveled cut, a rounded shape, or another detailed pattern to prevent the tube from collapsing at a predetermined radius. This pattern can also be rotated around the tube to create three-dimensional shapes and curves beyond a single plane.

[0033] This pattern will be laser-cut into the inner tube of the catheter and will be made of metal or polymer, and embedded in the catheter wall.

[0034] The first angular bend will be approximately 180 degrees, changing the direction of the catheter from the femoral vein access through the tricuspid valve and pointing towards the apex of the right ventricle. The second bend in the catheter will be an approximately 90-degree turn towards the interventricular septum, forming a "shepherd's hook" shape. This 90-degree orientation can also be achieved using a second internal catheter, which passes through the first, larger-diameter catheter to guide the access through the interventricular septum. This will require a 90-degree curve to steer the distal end towards the septal wall. Once the septal wall is penetrated, another 90-degree bend will be needed to direct the catheter towards the mitral valve. Between these two 90-degree bends, a gap of approximately 1 to 2 centimeters is needed to traverse the septal wall tissue. This straight segment can be pre-shaped into a curved configuration and actuated by a single or multiple drawstrings. A preferred embodiment utilizes the first catheter to achieve the 90-degree bend towards the interventricular septum.

[0035] The next internal catheter, pointing towards the mitral valve, can advance toward the valve leaflet in the left ventricle. The catheter tip, positioned beneath the leaflet, can locate the free edge of the mitral valve leaflet to secure chordae tendineae, used for repair of ruptured chordae tendineae or flail leaflets. Single or multiple chordae tendineae can originate from a single point of entry or from separate locations along the valve leaflet. From above, through a transseptal pathway, a second catheter can be positioned along the same free edge of the leaflet on the apical side. Coaxial positioning of these two catheters can be achieved by embedding them within the catheter or by advancing the magnetic tip through the central lumen of each catheter.

[0036] Positioning the two catheters above and below the leaflet, clamping them together to sandwich the leaflet, creates a passage through the leaflet for chordae tendineae repair or tethering, secured via a lower entry point originating from the right ventricle. The chordae tendineae repair can be achieved using PTFE sutures or another material suitable for permanent implantation. In cases where the lower entry point extends into the right ventricle, the anchor can be located entirely within the right ventricle or the interventricular septum, exposing only alternative suture material in the left ventricle. Anchor designs can resemble barbed anchors with single or multiple barbs for tissue engagement, plugs held from the right ventricular side of the septum, or screw devices for engaging tissue in the right or left ventricle. During or after chordae tendineae and anchoring system implantation, the attachment of the tissue anchor to the chordae tendineae leaflet attachment can be adjusted while monitoring the tension of the chordae tendineae or real-time echo results.

Claims

1. A tissue anchor for mitral valve chordae tendineae repair, the tissue anchor comprising an anchor for engaging cardiac tissue and at least one barb, wherein the tissue anchor is embedded within the cardiac tissue.

2. The tissue anchor as described in claim 1, characterized in that, The tissue anchor also includes anchors for engaging the surface of the right ventricle that crosses the septum.

3. The tissue anchor as described in claim 1, characterized in that, The tissue anchor also includes a swab.

4. A puncture tool for mitral valve chordae tendineae repair, the puncture tool comprising: The needle is configured to pass through the leaflet of the mitral valve at least once; as well as A suture, configured to connect the mitral valve leaflets to the ventricles of the heart.

5. The puncture tool as described in claim 4, characterized in that, The needle is connected to the suture.

6. The puncture tool as described in claim 4, characterized in that, The puncture tool is configured to pass a suture through the mitral valve leaflets.

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