Fastening system for engaging tissue of patient

Abstract

The invention relates to a fixation system for engaging tissue of a patient. The fixation system comprises an implantable fixation device and a catheter. The proximal element actuator (90A) extends through the first hole (402A) of the shaft (12) such that the catch element (337A, 338A) is disposed within the second hole (402B) of the shaft (12). When the catch element (337A, 338A) is disposed within the second aperture (402B), the actuator rod (64) is movable between a first position in which the actuator rod (64) at least partially blocks a path between the first aperture (402A) and the second aperture (402B) to prevent removal of the catch element (337A, 338A) from the first aperture (402A) and the second aperture (402B), and a second position in which the actuator rod (64) at least partially blocks a path between the first aperture (402A) and the second aperture (402B) to prevent removal of the catch element (337A, 338A) from the second aperture (402B). The path is not blocked by the actuator rod (64) and the catch element (337A, 338A) is able to travel along the path and exit the first hole (402A) and the second hole (402B).

Description

[0001] This application is a divisional application of the invention patent application with the application date of July 15, 2020, application number 202080061198.8 (PCT / US2020 / 042139), and invention name “Fixing and releasing mechanism of proximal element actuator”. Technical Field

[0002] The present invention generally relates to medical methods, medical devices, and medical systems. In particular, the present invention relates to methods, devices, and systems for endovascular, percutaneous, or minimally invasive surgical treatment of body tissue, such as tissue access or valve repair. More specifically, the present invention relates to the repair of heart valves and venous valves. Background Art

[0003] Mitral regurgitation is characterized by reverse flow from the heart's left ventricle through a dysfunctional mitral valve into the left atrium. During a normal cycle of myocardial contraction (systole), the mitral valve acts as a check valve to prevent oxygenated blood from flowing back into the left atrium. In this way, oxygenated blood is pumped through the aortic valve into the aorta. Valvular regurgitation can significantly reduce the heart's pumping efficiency, placing the patient at risk for severe, progressive heart failure.

[0004] Mitral regurgitation can be caused by a variety of different mechanical defects in the mitral valve or the left ventricular wall. The valve leaflets, the chordae connecting the leaflets to the papillary muscles, the papillary muscles, or the left ventricular wall may be damaged or otherwise malfunction. Often, the annulus may be damaged, dilated, or weakened, limiting the mitral valve's ability to close adequately against the high pressures in the left ventricle.

[0005] The most common treatment for mitral regurgitation relies on valve replacement or repair, which involves reshaping the leaflets and annulus, a procedure commonly referred to as annuloplasty. One existing technique for mitral valve repair that relies on suturing together adjacent segments of opposing leaflets is known as the "bow tie" or "edge-to-edge" technique. While all of these techniques can be very effective, they typically rely on open-heart surgery, in which the patient's chest is opened, typically via a sternotomy, and the patient is placed on cardiopulmonary bypass. The need to both open the chest and place the patient on cardiopulmonary bypass is invasive and associated with high mortality and morbidity rates. Recently, minimally invasive catheter-based procedures have been developed to deliver implantable clips to incompetent valves. These clips are used to secure portions of the leaflets together, thereby reducing regurgitation. While the clips appear promising, their delivery and deployment can be challenging. In some cases, visualization of the clips and leaflets using techniques such as fluoroscopy and echocardiography can be challenging. Therefore, improved attachment mechanisms and attachment assessment methods are desired.

[0006] For these reasons, it is desirable to provide improved methods, devices and systems for performing mitral and other heart valve repair. These methods, devices and systems should preferably not require open chest access and be capable of being performed intravascularly, i.e., using a device that is advanced to the heart from a point in the patient's vasculature distal to the heart, or by minimally invasive methods. In addition, these devices and systems should provide features that allow for simpler delivery of the fixation device and repositioning and optional removal of the fixation device prior to fixation to ensure optimal placement. Still more preferably, the methods, devices and systems will be useful for repairing tissues other than heart valves within the body. At least some of these objectives will be achieved by the invention described below.

[0007] Description of Related Technology

[0008] Minimally invasive and percutaneous techniques for coapting and modifying mitral valve leaflets to treat mitral regurgitation are described in PCT Publication Nos. WO 98 / 35638; WO 99 / 00059; WO 99 / 01377; and WO 00 / 03759.

[0009] Maisano et al. (1998) Eur. J. Cardiothorac. Surg. 13: 240-246; Fucci et al. (1995) Eur. J. Cardiothorac. Surg. 9: 621-627; and Umana et al. (1998) Ann. Thorac. Surg. 66: 1640-1646 described an open surgical procedure for performing an "edge-to-edge" or "bow-tie" mitral valve repair in which the edges of the opposing leaflets are sutured together to reduce regurgitation. Articles discussing the nature and treatment of dilated cardiomyopathy are reviewed by Dec and Fuster (1994) N. Engl. J. Med. 331: 1564-1575 and Alvarez et al. (1996) J. Thorac. Cardiovasc. Surg. 112: 238-247.

[0010] Mitral annuloplasty is described in the following publications: Bach and Bolling (1996) Am. J. Cardiol. 78:966-969; Kameda et al. (1996) Ann. Thorac. Surg. 61:1829-1832; Bach and Bolling (1995) Am. Heart J. 129:1165-1170; and Bolling et al. (1995) 109:676-683. Linear segmental annuloplasty for mitral valve repair is described by Ricchi et al. (1997) Ann. Thorac. Surg. 63:1805-1806. Tricuspid annuloplasty is described by McCarthy and Cosgrove (1997) Ann. Thorac. Surg. 64:267-268; Tager et al. (1998) Am. J. Cardiol. 81:1013-1016; and Abe et al. (1989) Ann. Thorac. Surg. 48:670-676.

[0011] Percutaneous transluminal cardiac repair procedures are described by Park et al. (1978) Circulation 58:600-608; Uchida et al. (1991) Am. Heart J. 121:1221-1224; and Ali Khan et al. (1991) Cathet. Cardiovasc. Diagn. 23:257-262.

[0012] Endovascular heart valve replacement is described in U.S. Patent Nos. 5,840,081; 5,411,552; 5,554,185; 5,332,402; 4,994,077; and 4,056,854. See also U.S. Patent No. 3,671,979 which describes a catheter for temporary placement of a prosthetic heart valve.

[0013] Other percutaneous and endovascular cardiac repair procedures are described in US Patent Nos. 4,917,089; 4,484,579; and 3,874,338 and PCT Publication No. WO 91 / 01689.

[0014] Thoracoscopic and other minimally invasive heart valve repair and replacement procedures are described in U.S. Patent Nos. 5,855,614; 5,829,447; 5,823,956; 5,797,960; 5,769,812; and 5,718,725. Summary of the Invention

[0015] According to the disclosed subject matter, a fixation system for engaging tissue of a patient is provided. The system includes an implantable fixation device having a first arm and a second arm, a first proximal element movable between a first position and a second position relative to the first arm, a second proximal element movable between a first position and a second position relative to the second arm, and a coupling member. The system also includes a delivery device having a catheter having a proximal end portion and a distal end portion, the catheter defining at least one lumen extending between the proximal and distal end portions, the shaft extending through the at least one lumen and releasably coupled to the coupling member. The delivery device further includes a first proximal element actuator and a second proximal element actuator, the first proximal element actuator extending through at least one lumen, the first proximal element actuator having a first end portion, a second end portion, and a mid-portion located between the first and second end portions, wherein the first proximal element actuator is coupled to the first proximal element at the mid-portion of the first proximal element actuator and the first proximal element actuator is actuatable to move the first proximal element between a first position and a second position, and a second proximal element actuator extending through at least one lumen, the second proximal element actuator having a first end portion, a second end portion, and a mid-portion located between the first and second end portions, wherein the second proximal element actuator is coupled to the second proximal element at the mid-portion of the second proximal element actuator and the second proximal element actuator is actuatable to move the second proximal element between the first position and the second position. The second end portion of the first proximal element actuator and the second end portion of the second proximal element actuator can each be coupled to at least one of the shaft and the coupling member.

[0016] In accordance with the disclosed subject matter, the first and second proximal element actuators can be coupled to the shaft and / or coupling member in various ways to enhance performance. For example, the first and second proximal element actuators can be released from at least one of the shaft and the coupling member by decoupling the shaft from the coupling member. The second end portion of the first proximal element actuator can include a first ring, and the second end portion of the second proximal element actuator can include a second ring. When the shaft and the coupling member are coupled together, each of the first and second rings can be disposed around at least one of the shaft and the coupling member.

[0017] The second end portion of the first proximal element actuator may include a first catch element, and the second end portion of the second proximal element actuator may include a second catch element. The first catch element may be a first spherical portion and the second catch element may be a second spherical portion. Alternatively, the first catch element may be a first trumpet-shaped portion and the second catch element may be a second trumpet-shaped portion. The first catch element may be configured to be received within the first opening of the shaft, and the second catch element may be configured to be received within the second opening of the shaft. The first catch element and the second catch element may be retained in the corresponding first opening and second opening by an actuator rod received within the tubular cavity of the shaft. The first catch element and the second catch element may be received between the shaft and the connecting member when the shaft and the connecting member are connected together in a releasable manner.

[0018] The delivery system may further include a first proximal element actuator spindle and a second proximal element actuator spindle extending through at least one lumen of the catheter. The first proximal element actuator spindle may be configured to releasably anchor the first proximal element actuator between the first proximal element actuator spindle and the catheter, and the second proximal element actuator spindle may be configured to releasably anchor the second proximal element actuator between the second proximal element actuator spindle and the catheter. The delivery device may further include a first cutter configured to cut the first proximal element actuator, thereby releasing the first proximal element. The delivery device may include a second cutter configured to cut the second proximal element actuator, thereby releasing the second proximal element.

[0019] According to another aspect of the disclosed subject matter, a fixation system for engaging tissue of a patient is provided. The system includes an implantable fixation device having a first arm and a second arm, a first proximal element movable between a first position and a second position relative to the first arm, a second proximal element movable between a first position and a second position relative to the second arm, and a coupling member. The system also includes a delivery device having a catheter and a shaft, the catheter having a proximal end portion and a distal end portion, the catheter defining at least one lumen extending between the proximal end portion and the distal end portion, the shaft extending through the at least one lumen and releasably coupled to the coupling member. The delivery device includes a first proximal element actuator and a second proximal element actuator, the first proximal element actuator extending through at least one lumen, the first proximal element actuator having a first end portion and a second end portion, wherein the first proximal element actuator is coupled to the first proximal element at the second end portion of the first proximal element actuator, and the first proximal element actuator is actuatable to move the first proximal element between a first position and a second position, and the second proximal element actuator extending through at least one lumen, the second proximal element actuator having a first end portion and a second end portion, wherein the second proximal element actuator is coupled to the second proximal element at the second end portion of the second proximal element actuator, and the second proximal element actuator is actuatable to move the second proximal element between the first position and the second position.

[0020] The first proximal element actuator and the second proximal element actuator can each include an outer sheath having a first window, an inner mandrel capable of axial movement relative to the outer sheath, and a suture extending from the outer sheath and defining a loop. The suture can be actuated between a captured position and a released position, in which the suture extends into the window of the outer sheath and is received by the inner mandrel through the loop.

[0021] The first proximal element actuator and the second proximal element actuator may each include an outer sheath that is axially movable relative to an inner member having distal jaws, wherein the outer sheath is configured to close the jaws by distal movement relative to the inner member and to open the jaws by proximal movement relative to the inner member. The first proximal element actuator and the second proximal element actuator may each include a weakened region proximal to the second end portion of the first proximal element actuator.

[0022] According to the disclosed subject matter, a fixation system for engaging tissue of a patient is provided, the fixation system comprising an implantable fixation device and a delivery device. The implantable fixation device may comprise a first arm and a second arm, a first proximal element movable between a first position and a second position relative to the first arm, a second proximal element movable between a first position and a second position relative to the second arm, and a coupling member. The delivery device may comprise a catheter having a proximal end portion and a distal end portion, the catheter defining at least one lumen extending between the proximal end portion and the distal end portion, the shaft extending through the at least one lumen and releasably coupled to the coupling member. The delivery device may further include a first proximal element actuator extending distally through at least one lumen and proximally back through at least one lumen to define a loop extending from a distal end portion of the catheter, the loop of the first proximal element actuator being coupled to the first proximal element and actuatable to move the first proximal element between a first position and a second position, and a second proximal element actuator extending distally through at least one lumen and proximally back through at least one lumen to define a loop extending from the distal end portion of the catheter, the loop of the second proximal element actuator being coupled to the second proximal element and actuatable to move the second proximal element between the first position and the second position. The loop defined by the first proximal element actuator and the loop defined by the second proximal element actuator may each be coupled to at least one of the shaft and the coupling member.

[0023]

[0011] Other aspects of the nature and advantages of the disclosed subject matter are set forth in the detailed description that follows in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Shown are the left ventricle and left atrium of the heart during systole.

[0025] Figure 2A The free edges of the leaflets in normal apposition are shown, and Figure 2B The free edge is shown in reverse apposition.

[0026] Figures 3A to 3C Grasping of the leaflet by the fixation device, inversion of the distal element of the fixation device, and removal of the fixation device are shown, respectively.

[0027] Figure 4 The position of the fixation device is shown in a desired orientation relative to the leaflets.

[0028] Figures 5A to 5B as well as Figures 6A to 6B An exemplary embodiment of the coupling mechanism of the present application is shown.

[0029] 7A to 7B as well as Figures 8A to 8B The movement of the fixing element of an embodiment of the fixing device of the present invention is shown.

[0030] Figure 9 Another embodiment of a fixing device is shown.

[0031] FIG. 10A to FIG. 10B 、 Figures 11A to 11B 、 FIG. 12A to FIG. 12B 、 13A to 13B as well as Figures 14 to 16 The fixation device of FIG. 7 is shown in various possible positions during introduction and placement of the device within the body for a therapeutic procedure.

[0032] 17A to 17C The securing device is shown in various positions.

[0033] Figures 18 and 19 An embodiment of a fixation device comprising a proximal element and a locking mechanism is shown.

[0034] Figures 20 to 21 Cross-sectional views of the locking mechanism are provided in the unlocked position and the locked position, respectively.

[0035] Figure 22 to Figure 27 Another embodiment of a securing device having a cover and a separate actuation mechanism is shown.

[0036] Figure 28 Another embodiment of a securing device comprising a clamp pusher is shown.

[0037] Figure 29 An embodiment of a fixation device having an independent proximal element actuation mechanism is shown.

[0038] Figure 30 Another embodiment of a fixation device having an independent proximal element actuation mechanism is shown.

[0039] Figure 31 Another embodiment of a fixation device having an independent proximal element actuation mechanism is shown.

[0040] Figure 32 Another embodiment of a fixation device having an independent proximal element actuation mechanism is shown.

[0041] Figure 33 Another embodiment of a fixation device having an independent proximal element actuation mechanism is shown.

[0042] Figures 34 to 35 Another embodiment of a fixation device is shown that includes an independent proximal element actuation mechanism having a single actuator.

[0043] Figures 36 to 40Shown is a diagram with a gripper pusher Figure 9 Fixing device.

[0044] Figures 41 to 46 Another embodiment of a fixture having a clamp pusher and a separate actuation mechanism is shown.

[0045] Figure 47 Another embodiment of a fixture having a clamp pusher and a separate actuation mechanism is shown.

[0046] Figure 48 Another embodiment of a fixture having a clamp pusher and a separate actuation mechanism with a single actuator is shown.

[0047] Figures 49A to 49C 、 Figures 50A to 50E 、 Figures 51A to 51B as well as Figures 52A to 52G Various embodiments of linearly coupling the proximal element to the proximal element of the fixation device are shown.

[0048] Figure 53 、 Figures 54A to 54D 、 Figures 55A to 55C as well as Figures 56A to 56B An actuator rod and associated components according to another embodiment of a securing device are shown.

[0049] Figure 57 and Figure 58 An embodiment for releasably coupling a clip pusher to a securing device is shown.

[0050] Figure 59A and Figure 59B The configuration of the proximal element actuator is shown.

[0051] Figure 60A and Figure 60B Another configuration of a proximal element actuator is shown.

[0052] Figure 61 A heart with functional mitral regurgitation is schematically shown.

[0053] Figures 62A to 62B Schematically illustrated is continuous leaflet capture in a heart with functional mitral regurgitation using an implantable fixation device of the disclosed subject matter.

[0054] Figures 63A to 63B A heart with degenerative mitral regurgitation is schematically shown.

[0055] Figures 64A to 64B Schematically illustrates sequential leaflet capture in a heart with degenerative mitral regurgitation using an implantable fixation device of the disclosed subject matter.

[0056] Figures 65A to 65B Shown is an enlarged view of a distal end portion of a delivery system shaft having a bore for receiving a catch element in accordance with the disclosed subject matter.

[0057] Figure 65C yes Figure 65B Cross-sectional view of the distal end portion of the delivery system shaft.

[0058] Figure 65D The distal end portion of the proximal element actuator is shown with a trumpet-shaped catch.

[0059] Figure 65E Shown is an enlarged view of a distal end portion of a delivery shaft having a bore for receiving a catch element in accordance with the disclosed subject matter.

[0060] Figure 65F The distal end portion of the proximal element actuator is shown with a ball-shaped catch.

[0061] Figure 65G Shown is an enlarged view of a distal end portion of a delivery shaft having a bore for receiving a catch element in accordance with the disclosed subject matter.

[0062] Figure 65H Shown is an enlarged view of the edge of a bore of a delivery shaft having chamfered edges in accordance with the disclosed subject matter.

[0063] Figure 65I Shown is an enlarged view of the edge of a bore of a delivery shaft having a chamfer including rounded edges in accordance with the disclosed subject matter.

[0064] Figure 65J Shown is an enlarged view of a delivery shaft including an angle-reducing feature in accordance with the disclosed subject matter.

[0065] Figures 66A to 66D Shown is an enlarged view of the distal end portion of a delivery system shaft, a proximal element actuator, and a proximal element and the coupling therebetween using a ring in accordance with the disclosed subject matter.

[0066] Figure 67 Shown is an enlarged view of the distal end portion of a delivery system shaft, a proximal element actuator, and a proximal element, and the coupling therebetween using a mandrel, in accordance with the disclosed subject matter.

[0067] Figure 68 Shown is an enlarged view of the distal end portion of a delivery system shaft, a proximal element actuator, and a proximal element, and the coupling therebetween using a cutter, in accordance with the disclosed subject matter.

[0068] Figures 69A to 69BShown is an enlarged view of a distal end portion of a proximal element actuator and a proximal element and the coupling therebetween using a ring in accordance with the disclosed subject matter.

[0069] Figure 70 Shown is an enlarged view of a distal end portion of a proximal element actuator and a proximal element and the coupling therebetween using a jaw in accordance with the disclosed subject matter.

[0070] Figure 71 Shown is an enlarged view of a distal end portion of a proximal element actuator and a proximal element and the coupling therebetween using a necking region in accordance with the disclosed subject matter. DETAILED DESCRIPTION

[0071] 1. Cardiac physiology

[0072] exist Figure 1 FIG shows the left ventricle LV of a normal heart H during systole. The left ventricle LV contracts and blood flows outward through the tricuspid valve (aorta) AV in the direction of the arrow. Backflow or "regurgitation" of blood through the mitral valve MV is prevented because the mitral valve is constructed as a "check valve" that prevents backflow when the pressure in the left ventricle is higher than the pressure in the left atrium LA. Figure 1 As shown, the mitral valve MV comprises a pair of leaflets having free edges FE that converge evenly to close. The opposite ends of the leaflets LF are attached to the surrounding heart structures along an annular region called the annulus AN. The free edges FE of the leaflets LF are fastened to the lower portion of the left ventricle LV by chordae tendineae CT (hereinafter referred to as chordae tendineae) which comprise a plurality of branching tendons fastened over the lower surface of each leaflet in the leaflets LF. The chordae tendineae CT are in turn attached to the papillary muscles PM that extend upward from the lower portion of the left ventricle and the intraventricular septum IVS.

[0073] Many structural defects in the heart can cause mitral regurgitation. Regurgitation occurs when the valve leaflets do not close properly, allowing leakage from the ventricles into the atria. Figure 2A As shown, the free edges of the anterior and posterior leaflets converge normally along the line of coaptation C. Figure 2B An example of a defect that causes regurgitation is shown in . Here, enlargement of the heart causes the mitral valve annulus to enlarge so that the free edges FE do not converge during systole. This results in a gap G that allows blood to leak through the valve during ventricular contraction. Ruptured or elongated chordae tendineae may also cause leaflet prolapse because insufficient tension is transmitted to the leaflets via the chordae tendineae. The two leaflets do not converge properly and leakage will occur from the left ventricle into the left atrium while the other leaflet maintains its normal contour. This type of regurgitation may also occur in patients with ischemic heart disease where the left ventricle does not contract sufficiently to achieve proper closure.

[0074] 2. General Overview

[0075] Aspects of the present invention provide methods and devices for grasping, approximating, and securing tissue, such as valve leaflets, to treat heart valve regurgitation, particularly mitral regurgitation. The present invention also provides features that allow the device to be repositioned and removed, if desired, particularly in areas where removal may be hindered by anatomical features, such as chordae tendineae. Such removal will allow the surgeon to reapproach the valve in a new manner, if desired.

[0076] The gripping will preferably be non-invasive which provides a number of benefits. Non-invasive means that the devices and methods of the present invention can be applied to the leaflets and then removed without causing any significant clinical damage to the leaflet structure or function. The leaflets and valve continue to perform essentially the same function as before the application of the present invention. Therefore, some minor penetration or indentation of the leaflets may occur using the present invention and still meet the definition of "non-invasive". This enables the device of the present invention to be applied to diseased valves and enables the device of the present invention to be removed or repositioned when desired without negatively affecting valve function. In addition, it should be understood that in some cases, it may be necessary or desirable to puncture or otherwise permanently affect the leaflets during gripping, fixation, or both gripping and fixation. In some of these cases, gripping and fixation can be accomplished by a single device. Although many embodiments are provided to achieve these results, a general overview of the basic features will be presented herein. These features are not intended to limit the scope of the invention and the purpose of presenting these features is to provide a basis for the description of the various embodiments presented later in this application.

[0077] The devices and methods of the present invention rely on the use of an interventional tool that is positioned proximate the desired treatment site and used to grasp the target tissue. In intravascular applications, the interventional tool is typically an interventional catheter. In surgical applications, the interventional tool is typically an interventional instrument. In a preferred embodiment, fixation of the grasped tissue is accomplished by maintaining the grasp using a portion of the interventional tool that remains as an implant. While the present invention may have a variety of applications for tissue access and fixation throughout the body, the present invention is particularly well suited for the repair of valves, particularly heart valves such as the mitral valve. Reference Figure 3A , an interventional tool 10 having a delivery device such as a shaft 12 and a fixation device 14 is shown approaching the mitral valve MV from the atrial side and grasping the leaflets LF. As described above, the mitral valve can be accessed surgically or by using endovascular techniques and can be accessed by a transventricular retrograde approach or by a transatrial antegrade approach. For illustrative purposes, an antegrade approach is described.

[0078] The fixation device 14 is releasably attached to the shaft 12 of the interventional tool 10 at the distal end of the shaft 12. When describing the device of the present invention herein, "proximal" shall refer to the direction toward the end of the device that is manipulated by the user outside the patient's body, and "distal" shall refer to the direction toward the working end of the device that is positioned at the treatment site and away from the user. With respect to the mitral valve, proximal shall refer to the upstream side of the atria or leaflets, and distal shall refer to the downstream side of the ventricles or leaflets.

[0079] The fixation device 14 generally includes a proximal element 16 (or grasping element; wherein "proximal element" and "grasping element" are used interchangeably herein) and a distal element 18 (or fixation element; wherein "distal element" and "fixation element" are used interchangeably herein) that extend radially outward and are positionable on opposite sides of the leaflets LF shown so as to capture the leaflets or hold the leaflets therebetween. The proximal element 16 preferably comprises a cobalt-chromium alloy, nickel-titanium nobium, or stainless steel, and the distal element 18 preferably comprises a cobalt-chromium alloy or stainless steel, however any suitable material may be used. The fixation device 14 is capable of being coupled to the shaft 12 by a coupling mechanism 17. The coupling mechanism 17 allows the fixation device 14 to be removed and left as an implant to hold the leaflets together in an apposed position.

[0080] In some cases, it may be desirable to reposition or remove the fixation device 14 after the proximal element 16, the distal element 18, or both the proximal element 16 and the distal element 18 have been deployed to capture the leaflets LF. Such repositioning or removal may be necessary for a variety of reasons, such as: reapproximating the valve in an attempt to achieve better valve function, more ideally positioning the device 14 on the leaflets, achieving a better grip on the leaflets; detangling the device 14 from surrounding tissue, such as chordae tendineae; replacing the device 14 with a device having a different design; or interrupting the fixation procedure, to name a few. To facilitate repositioning or removal of the fixation device 14, the distal element 18 is releasable and optionally invertible into a configuration suitable for withdrawing the device 14 from the valve without tangling or interfering with or damaging the chordae tendineae, leaflets, or other tissue. Figure 3B 4. An inverted position is shown, wherein the distal element 18 can be moved in the direction of arrow 40 to an inverted position. Likewise, the proximal element 16 can be raised if desired. In the inverted position, the device 14 can be repositioned to a desired orientation, wherein the distal element can then be restored to its original position. Figure 3A Alternatively, as Figure 3CAs shown, the fixation device 14 can be withdrawn from the leaflets (indicated by arrow 42). Such inversion reduces damage to the leaflets and minimizes any entanglement of the device with surrounding tissue. Once the device 14 is withdrawn through the leaflets, the proximal and distal elements can be moved to a closed position or configuration suitable for removal from the body or reinsertion through the mitral valve.

[0081] Figure 4 The position of the fixation device 14 in a desired orientation relative to the leaflets LF is shown. This is a short-axis view of the mitral valve MV from the atrial side, and therefore the proximal element 16 is shown in solid lines and the distal element 18 is shown in dashed lines. The proximal element 16 and the distal element 18 are positioned substantially perpendicular to the line of apposition C. The device 14 can be moved generally along the line of apposition to a regurgitant position. The leaflets LF are held in place so that during diastole, as shown in FIG. Figure 4 As shown, the leaflets LF are maintained in a position between the elements 16, 18 surrounded by the opening O created by the diastolic pressure gradient. Advantageously, the leaflets LF are aligned so that the proximal or upstream surfaces of the leaflets LF face each other in a vertical orientation parallel to the direction of blood flow through the mitral valve MV. The upstream surfaces can be brought together so as to be in contact with each other or can be maintained slightly apart, but will preferably be maintained in a vertical orientation along which the upstream surfaces face each other at the point of apposition. This simulates the double orifice geometry of a standard surgical bow-tie repair. A color Doppler echo will be displayed in the event that the regurgitation of the valve has been reduced. If the resulting mitral flow pattern is satisfactory, the leaflets can be fixed together in this orientation. If the resulting color Doppler image shows that the mitral regurgitation has not improved sufficiently, the interventional tool 10 can be repositioned. This can be repeated until the optimal result is produced, wherein the leaflets LF remain in place.

[0082] Once the leaflets are in coaptation in the desired arrangement, the fixation device 14 is then detached from the shaft 12 and left as an implant to hold the leaflets together in the coapted position. As previously described, the fixation device 14 is coupled to the shaft 12 by the coupling mechanism 17 . Figures 5A to 5B 、 Figures 6A to 6B An exemplary embodiment of such a coupling mechanism is shown. Figure 5A An upper shaft 20 and a removable lower shaft 22 are shown, interlocked at a line of engagement or mating surface 24. The mating surface 24 can have any shape or curvature that will allow or facilitate interlocking and subsequent removal. As shown, a close-fitting outer sheath 26 is positioned over the shafts 20, 22 to cover the mating surface 24. Figure 5B The lower shaft 22 is shown separated from the upper shaft 20. This is achieved by retracting the outer sheath 26 so that the mating surfaces 24 are exposed, thereby allowing the shafts 20, 22 to separate.

[0083] Similarly, Figure 6A The upper tubular shaft 28 and the removable lower tubular shaft 30 are shown interlocked at a mating surface 32. Likewise, the mating surface 32 can have any shape or curvature that will allow or facilitate interlocking and subsequent removal. The upper tubular shaft 28 and the lower tubular shaft 30 form an outer member having an axial passage. As shown, a close-fitting rod 34 or inner member is inserted through the tubular shafts 28, 30 to bridge the mating surface 32. Figure 6B The lower shaft 30 is shown separated from the upper shaft 28. This is achieved by retracting the rod 34 to a position above the mating surface 32, which in turn allows the shafts 28, 30 to separate. Other examples of coupling mechanisms are described and shown in co-pending U.S. patent application Ser. No. 09 / 894,493, which is incorporated herein by reference for all purposes.

[0084] Similarly, Figure 6A The upper tubular shaft 28 and the removable lower tubular shaft 30 are shown interlocked at a mating surface 32. Likewise, the mating surface 32 can have any shape or curvature that will allow or facilitate interlocking and subsequent removal. The upper tubular shaft 28 and the lower tubular shaft 30 form an outer member having an axial passage. As shown, a close-fitting rod 34 or inner member is inserted through the tubular shafts 28, 30 to bridge the mating surface 32. Figure 6B The lower shaft 30 is shown separated from the upper shaft 28. This is achieved by retracting the rod 34 to a position above the mating surface 32, which in turn allows the shafts 28, 30 to separate. Other examples of coupling mechanisms are described and shown in co-pending U.S. patent application Ser. No. 09 / 894,493, which is incorporated herein by reference for all purposes.

[0085] 3. Fixtures

[0086] A. Import and Place

[0087] The fixation device 14 is delivered to the valve or desired tissue using a delivery device. Depending on the application, the delivery device can be rigid or flexible. For intravascular applications, the delivery device includes a flexible delivery catheter, which will be described in a later section. Typically, however, such a catheter includes a shaft having a proximal end and a distal end and a fixation device releasably attached to the distal end of the shaft. The shaft is typically elongated and flexible, suitable for intravascular introduction. Alternatively, the delivery device may include a shorter and less flexible interventional instrument that can be used for transthoracic surgical introduction through the heart wall, although some flexibility and minimal profile are generally desired. As Figure 3AAs shown, the fixation device can be releasably coupled to the delivery device. The fixation device can have a variety of forms, several embodiments of which will be described herein.

[0088] Figures 7A to 8B Embodiments of the securing device 14 are shown in various positions or configurations. Figure 7A A fixation device 14 is shown in a closed configuration for delivery through a patient's vasculature, and in this example, through the mitral valve. The fixation device 14 includes a coupling member 19 that allows the fixation device 14 to be disassembled for implantation. In this example, the coupling member 19 is shown as comprising Figures 5A to 5B 's lower shaft 22 and mating surface 24, and thus the coupling member 19 will function similarly to that described above. The fixture 14 also includes a pair of opposing distal elements 18, each distal element 18 having an engagement surface 50 that faces inwardly toward the opposing distal element 18 in the closed configuration. The distal elements 18 preferably include elongated arms 53, each having a proximal end 52 rotatably connected to the coupling member 19 and a free end 54. Suitable connection means for the arms 53 to the coupling member 19 include pins, living hinges, or other known rotational connection mechanisms. Figure 7A In the closed configuration, free ends 54 point in a first direction such that arms 53 and engagement surface 50 are nearly parallel to each other and to axis 21, and are preferably slightly angled inwardly toward each other. In a preferred embodiment, when no tissue is present between arms 53, arms 53 can be closed until free ends 54 contact each other or engage shaft 12 when fixation device 14 is attached to shaft 12, thereby minimizing the profile of fixation device 14 for passage through a delivery device.

[0089] Figures 7B to 8A The fixture 14 is shown in an open position wherein the engagement surfaces 50 are disposed apart at a separation angle 56, wherein the separation angle 56 is typically up to about 180 degrees, preferably up to 90 to 180 degrees, and wherein the arms 53 are disposed generally symmetrically relative to the axis 21. The arms 53 can be moved to the open position by a variety of actuation mechanisms. For example, as indicated by arrow 62, a plunger or actuator rod can be advanced through the coupling member 19 to engage a spring or spring-loaded actuation mechanism 58 attached to the distal element 18. The distal element 18 is caused to rotate relative to the coupling member 19 by applying a force against the actuation mechanism 58. The distal element 18 can be maintained in the open position by the actuator rod acting against the resistance provided by the spring of the actuation mechanism 58, which moves the distal element 18 toward the coupling member 19 when the distal elements 18 are separated by less than 180 degrees. Figure 7A The spring load of the actuating mechanism 58 resists the outward movement of the actuating mechanism 58 and pushes the device 14 toward the closed position.

[0090] In this embodiment, the proximal element 16 comprises a resilient looped wire form that is biased outwardly and attached to the coupling member 19 so as to be biased to Figure 8A The open position shown, but can be moved in an inward rotational manner when the arms 53 are closed. The wire form can be flexible enough to be rigidly attached to the coupling member 19 and be able to elastically deflect inwardly, or the wire form can be attached by a rotating coupling, such as a pin or a living hinge. In use, the leaflet LF is positioned between the proximal element 16 and the distal element 18. Once the leaflet LF is positioned between the proximal element 16 and the distal element 18, the distal element 18 can be closed, thereby compressing the leaflet between the engagement surface 50 and the proximal element 18. Depending on the thickness of the leaflet, the arrangement of the leaflet, the position of the fixation device on the leaflet and other factors, the arms 53 can be maintained at Figure 7B open position, move to Figure 7A The fixation device 14 can be placed in a fully closed position or in any of a variety of positions between the open position and the fully closed position to cause the leaflets LF to coapt and maintain the leaflets LF in the desired position with a desired degree of force. In any case, the fixation device 14 will remain in place as an implant after being separated from the delivery catheter.

[0091] In some cases, as previously described, it may be desirable to reopen the fixation device 14 after initial placement. To reopen the device 14, the Figure 7B , the actuator rod can be re-advanced or reinserted through the coupling member 19 and re-advanced to press against the actuator mechanism 58. Again, this advancement applies a force against the actuator mechanism 58 in the manner described above, thereby moving the arms 53 outward to release the force against the leaflets and move the engagement surface 50 away from the proximal element 16. The leaflets are then free to move relative to the fixation device 14. The fixation device 14 can then be repositioned as needed and the actuator rod retracted to reclose the distal element 18 to bring the leaflets into coaptation.

[0092] In some cases, after initial insertion through the valve, it may be desirable to withdraw the fixation device 14 back through the valve or completely out of the patient's body. 7A to 8A If an attempt is made to fix the fixed element 14 in the closed position or the open position shown, there is a risk that the arms 53 will interfere with or become entangled with the chordae tendineae, the leaflets or other tissues. To avoid this, the fixing element 14 is preferably adapted to invert the arms 53 so that the free ends 54 point in a second direction opposite to the first direction in which the free ends 54 point in the closed position, each arm 53 being at an obtuse angle relative to the axis 21, as shown. Figure 8BAs shown. The arms 53 can be rotated so that the engagement surfaces 50 are disposed at a separation angle 56 of up to 360 degrees, and preferably at least up to 270 degrees. This can be achieved by applying a force against the actuation mechanism 58 using a push rod or plunger extending through the coupling member 19 as described above. In this embodiment, once the distal elements 18 have been rotated apart by more than 180 degrees, the spring load of the actuation mechanism 58 biases the distal elements 18 toward the inverted position. The spring load of the actuation mechanism 58 resists the outward movement of the actuation mechanism 58 and pushes the device 14 toward the inverted position.

[0093] With the arms 53 in the inverted position, the engagement surface 50 provides an atraumatic surface to deflect tissue as the fixation device is withdrawn. This allows the device to be retracted back through the annulus without risk of damaging the valve and other tissue. In some cases, once the fixation device 14 has been pulled back through the valve, it will be desirable to return the device to the closed position for withdrawal of the device from the body (through the vasculature or through a surgical opening).

[0094] Figures 7A to 8B The embodiment shown in FIG is assembled from separate components comprising biocompatible materials. The components may be formed from the same or different materials including, but not limited to, stainless steel or other metals, (Elgiloy), nitinol, titanium, tantalum, metal alloys, or polymers. Furthermore, some or all of these components may be made of bioresorbable materials that will be absorbed by the surrounding tissue or will dissolve in the bloodstream after implantation. It has been found that in mitral valve repair applications, the fixation device of the present invention is completely surrounded by tissue within a few months of implantation, after which the device can dissolve or be absorbed without negatively impacting the repair.

[0095] Figure 9Another embodiment of a fixation device 14 is shown. Here, the fixation device 14 is shown coupled to the shaft 12 to form the interventional tool 10. The fixation device 14 includes a coupling member 19 and a pair of opposing distal elements 18. The distal elements 18 include elongated arms 53, each having a proximal end 52 rotatably connected to the coupling member 19 and a free end 54. The free end 54 has a rounded shape to minimize interference with and damage to surrounding tissue structures. Preferably, each free end 54 defines a curvature about two axes, one of which is an axis 66 perpendicular to the longitudinal axis of the arm 53. Thus, the engagement surface 50 has a cupped or concave shape for the surface area that contacts the tissue and helps grasp and retain the leaflets. This also allows the arms 53 to nest around the shaft 12 in a closed position, minimizing the device's profile. Preferably, the arms 53 are at least partially concave or curved inward about their longitudinal axis 66. Additionally, preferably, each free end 54 defines a curvature about an axis 67 perpendicular to the axis 66 or the longitudinal axis of the arm 53. This curvature is the reverse curvature of the distal-most portion along the free end 54. Likewise, the longitudinal edges of the free end 54 may be flared outwardly. Both the reverse curvature and the flaring minimize damage to tissue with which it is engaged.

[0096] In an embodiment suitable for mitral valve repair, the lateral width across the engagement surface 50 (which determines the width of the tissue engagement) is at least about 2 mm, typically 3 mm to 10 mm, and preferably about 4 mm to 6 mm. In some cases, a wider engagement is desired, wherein the engagement surface 50 is larger, for example, about 2 cm, or multiple fixation devices are used adjacent to each other. The arm 53 and the engagement surface 50 are configured to engage a length of tissue of about 4 mm to 10 mm along the longitudinal axis of the arm 53, and preferably about 6 mm to 8 mm. The arm 53 also includes a plurality of openings to enhance grip and promote ingrowth of tissue after implantation.

[0097] The leaflets are captured between the distal element 18 and the proximal element 16. In some embodiments, the proximal element 16 is flexible, resilient, and cantilevered from the coupling member 19. The proximal element is preferably resiliently biased toward the distal element. Each proximal element 16 is shaped and positioned to be at least partially recessed in a concave portion of the distal element 18 when no tissue is present. Figure 9 As shown, when the fixation device 14 is in the open position, the proximal elements 16 are shaped such that each proximal element 16 separates from the engagement surface 50 near the proximal end 52 of the arm 53 with the free end of the proximal element contacting the engagement surface 50 and slopes toward the engagement surface 50 near the free end 54. This shape of the proximal elements 16 accommodates leaflets or other tissues of varying thickness.

[0098] The proximal element 16 includes a plurality of openings 63 and scalloped side edges 61 to enhance tissue grip. The proximal element 16 may optionally include friction attachments, friction features, or grip-enhancing elements to aid in grasping and / or retaining the leaflets. In a preferred embodiment, the friction attachments include barbs 60 having tapered tips extending toward the engagement surface 50. It will be appreciated that any suitable friction attachment may be used, such as forks, coils, strips, barbs, grooves, channels, protrusions, surface roughening, sintering, high-friction pads, coatings, or combinations thereof. Optionally, magnets may be present in the proximal and / or distal elements. It will be appreciated that the mating surfaces may be made of or include materials of opposite magnetic charge to induce an attractive force through magnetic forces. For example, the proximal and distal elements may each include magnetic materials of opposite magnetic charge, thereby maintaining tissue under constant compression between the proximal and distal elements to facilitate faster tissue healing and ingrowth. Furthermore, magnetic force can be used to pull the proximal element 16 toward the distal element 18, or additionally or alternatively, to bias the proximal element toward the distal element. This can facilitate deployment of the proximal element 16. In another example, the distal elements 18 each include magnetic materials of opposite magnetic charge such that tissue positioned between the distal elements 18 is held between the distal elements 18 by the magnetic force.

[0099] As described below, the proximal element 16 can be covered with a fabric or other flexible material to enhance grip and tissue ingrowth after implantation. Preferably, when a fabric or covering is used in combination with barbs or other friction features, these features will protrude through the fabric or other covering to contact any tissue engaged by the proximal element 16.

[0100] In an exemplary embodiment, the proximal element 16 is formed from a sheet of metal of a spring-like material using a stamping operation that creates the opening 63, the scalloped edge 61, and the barbs 60. Alternatively, the proximal element 16 may comprise a spring-like material or be molded from a biocompatible polymer. It should be noted that while some types of friction attachments that may be used in the present invention may permanently alter or cause some damage to the tissue thereby engaged, in preferred embodiments, the friction attachments will be atraumatic and will not damage or otherwise affect the tissue in a clinically significant manner. For example, in the case of the barbs 60, it has been demonstrated that after engaging the mitral valve leaflets by the fixation device 14, which should subsequently be removed during surgery, the barbs 60 do not leave significant permanent scarring or other damage to the leaflet tissue and are therefore considered atraumatic.

[0101] The fixation device 14 also includes an actuation mechanism 58. In this embodiment, the actuation mechanism 58 includes two connecting members or legs 68, each leg 68 having a first end 70 and a second end 72, the first end 70 being rotatably engaged with one of the distal elements 18 at a riveted joint 76, and the second end 72 being rotatably engaged with a stud 74. The legs 68 are preferably comprised of a rigid or semi-rigid metal or polymer, such as Cobalt chromium alloy or stainless steel, however, any suitable material can be used. Although two legs 68 are shown to be pinned to the stud 74 by a single rivet 78 in the embodiment, it is understood that each leg 68 can be individually attached to the stud 74 by an independent rivet or pin. The stud 74 can be engaged with the actuator rod 64 (not shown), which extends through the shaft 12 and can be axially extended and retracted to move the stud 74 and therefore the legs 68, which rotate the distal element 18 between the closed, open and inverted positions. Similarly, the fixation of the stud 74 holds the legs 68 in place and therefore the distal element 18 in the desired position. The stud 74 can also be locked in place by a locking function, which will be further described in the following section.

[0102] In any of the embodiments of the fixation device 14 disclosed herein, it may be desirable to provide some mobility or flexibility in the distal element 18 and / or the proximal element 16 when in the closed position, so that these elements can move or flex as the leaflets open or close. This provides shock absorption and thereby reduces forces on the leaflets and minimizes the possibility of tearing or other damage to the leaflets. This mobility or flexibility can be provided by constructing the distal element 18 from a flexible, resilient metal or polymer of appropriate thickness. Furthermore, the locking mechanism of the fixation device (described below) can be constructed from a flexible material to allow some slight movement of the proximal and distal elements even when locked. Furthermore, the distal element 18 can be connected to the coupling mechanism 19 or the actuation mechanism 58 by a mechanism that biases the distal element into the closed position (inward) but permits the arms to open slightly in response to forces applied by the leaflets. For example, rather than being pinned at a single point, these components can be pinned via a slot that allows a small amount of translation of the pin in response to forces resisting the arms. A spring is used to bias the pinned component toward one end of the slot.

[0103] FIG. 10A to FIG. 10B 、 Figures 11A to 11B 、 FIG. 12A to FIG. 12B 、 13A to 13B as well as Figures 14 to 16 The device 14 is shown in various possible positions during introduction and placement in the body for a therapeutic procedure. Figure 9 Implementation of the fixing device 14. Figure 10AAn embodiment of an interventional tool 10 is shown being delivered through a catheter 86. It will be appreciated that the interventional tool 10 can take the form of a catheter, and similarly, the catheter 86 can take the form of a guide catheter or sheath. However, in this example, the terms interventional tool 10 and catheter 86 will be used. The interventional tool 10 includes a fixation device 14 coupled to a shaft 12, and the fixation device 14 is shown in a closed position. Figure 10B Shown in a larger diagram Figure 10A . In the closed position, the opposing pair of distal elements 18 are positioned so that the engagement surfaces 50 face each other. Each distal element 18 includes an elongated arm 53 having a cup-like or concave shape so that the arms 53 together encompass the shaft 12 and optionally contact each other on opposite sides of the shaft. This provides a small profile for the fixation device 14 that can be easily passed through the catheter 86 and through any anatomical structure, such as the mitral valve. In addition, Figure 10B Also included is an actuation mechanism 58. In this embodiment, the actuation mechanism 58 includes two legs 68, each movably coupled to a base 69. The base 69 engages an actuator rod 64 that extends through the shaft 12 and is used to manipulate the fixture 14. In some embodiments, the actuator rod 64 is directly attached to the actuation mechanism 58, particularly to the base 69. However, the actuator rod 64 may alternatively be attached to a stud 74, which in turn is attached to the base 69. In some embodiments, the stud 74 is threaded such that the actuator rod 64 is attached to the stud 74 via a screw-type action. However, the rod 64 and stud 74 may be engaged by any releasable mechanism to allow the fixture 14 to be separated from the shaft 12.

[0104] Figures 11A to 11B The fixture 14 is shown in an open position. In the open position, the distal element 18 is rotated so that the engagement surface 50 faces in a first direction. The distal advancement of the stud 74 relative to the coupling member 19, through the action of the actuator rod 64, applies a force to the distal element 18. Due to the freedom of movement in this direction, the distal element 18 begins to rotate about the engagement portion 76. This radially outward rotation and movement of the distal element 18 causes the legs 68 to rotate about the engagement portion 80, causing them to point slightly outward. The stud 74 can be advanced to any desired distance related to the desired separation of the distal element 18. In the open position, the engagement surface 50 is arranged at an acute angle relative to the shaft 12, and the engagement surfaces 50 are preferably arranged at an angle between 90 and 180 degrees relative to each other. In one embodiment, in the open position, the free ends 54 of the arms 53 have a span of approximately 10 to 20 mm, typically approximately 12 to 18 mm, and preferably approximately 14 to 16 mm.

[0105] The proximal element 16 is generally biased outwardly toward the arm 53. The proximal element 16 can be moved inwardly toward the shaft 12 and held against the shaft 12 by means of a proximal element wire 90, which can be in the form of a suture, wire, nitinol wire, rod, cable, polymer wire, or other suitable structure. The proximal element wire 90 can be connected to the proximal element 16 by threading the wire 90 in a variety of ways. Figure 11A As shown, when the proximal element 16 has a ring shape, the wire 90 can pass through the ring and be folded in half. Figure 11B As shown, when the proximal element 16 has an elongated solid shape, the wire 90 can pass through one or more openings 63 in the element 16. Figure 11B As shown in FIG, a wire loop 48 may be present on proximal element 16, through which proximal element wire 90 may be threaded and folded in half. Such a wire loop 48 may help reduce friction on proximal element wire 90, or, when proximal element 16 is solid or lacks other loops or openings, proximal element wire 90 may be attached through the wire loop 48. Proximal element wire 90 may be attached to proximal element 16 via a detachable device that allows a single wire 90 to be attached to proximal element 16 without being folded in half, and also allows a single wire 90 to be directly detached from proximal element 16 when desired. Examples of such detachable devices include hooks, catches, clips, or breakable couplings, to name a few. By applying sufficient tension to proximal element wire 90, the detachable device can be detached from proximal element 16, such as by breaking the coupling. Other mechanisms for detachment may also be used. Similarly, locking wire 92 may be attached to and detached from the locking mechanism via similar detachable devices.

[0106] In the open position, the fixation device 14 can engage tissue to be accessed or treated. Figure 9 to Figure 1 The embodiment shown in Figure 1 is suitable for repairing the mitral valve using an antegrade approach from the left atrium. The interventional tool 10 is advanced through the mitral valve from the left atrium to the left ventricle. The distal element 18 is oriented perpendicular to the line of apposition and is then positioned so that the engagement surface 50 contacts the ventricular surface of the leaflet, thereby grasping the leaflet. The proximal element 16 is retained on the atrial side of the leaflet so that the leaflet is located between the proximal element and the distal element. In this embodiment, the proximal element 16 has a friction attachment, such as a barb 60 that points towards the distal element 18. However, at this time, neither the proximal element 16 nor the barb 60 contacts the leaflet.

[0107] The interventional tool 10 can be repeatedly manipulated to reposition the fixation device 14 so that the leaflets are properly contacted or gripped at the desired location. Repositioning is achieved while the fixation device is in the open position. In some cases, regurgitation can also be checked while the device 14 is in the open position. If regurgitation is not satisfactorily reduced, the device can be repositioned and regurgitation checked again until the desired result is achieved.

[0108] It may also be desirable to invert the fixation device 14 to aid in repositioning or removal of the fixation device 14 . FIG. 12A to FIG. 12B Fixture 14 is shown in an inverted position. Further advancement of stud 74 relative to coupling member 19 further rotates distal element 18, causing engagement surface 50 to face outward and free end 54 to point distally, with each arm 53 forming an obtuse angle relative to shaft 12. The angle between arms 53 is preferably in the range of approximately 270 to 360 degrees. Further advancement of stud 74 further rotates distal element 18 about joint 76. This radially outward rotation and movement of distal element 18 causes legs 68 to rotate about joint 80, returning them to their initial position, where they are generally parallel to one another. Stud 74 can be advanced any desired distance associated with the desired inversion of distal element 18. Preferably, in the fully inverted position, the span between free ends 54 does not exceed approximately 20 mm, is typically less than approximately 16 mm, and is preferably approximately 12 to 14 mm. In this illustration, proximal element 16 is held in place against shaft 12 by applying tension to proximal element wire 90. Thus, a relatively large space can be created between elements 16, 18 for repositioning. In addition, the inverted position allows the fixation device 14 to be withdrawn through the valve while minimizing damage to the leaflets. The engagement surface 50 provides an atraumatic surface for deflecting tissue when the fixation device is retracted proximally. It should also be noted that the barbs 60 are slightly angled in the distal direction (away from the free end of the proximal element 16) to reduce the risk that the barbs will snag or tear tissue when the fixation device is withdrawn.

[0109] Once the fixation device 14 has been positioned in the desired position against the leaflets, the leaflets may be captured between the proximal and distal elements 16 , 18 . 13A to 13B The fixation device 14 is shown in such a position. Here, the proximal element 16 is lowered towards the engagement surface 50 so that the leaflet is held between the proximal element 16 and the engagement surface 50. Figure 13B In FIG, the proximal element 16 is shown as including barbs 60 that can be used to provide atraumatic grip of the leaflets. Alternatively, larger, more pointed barbs or other penetrating structures can be used to pierce the leaflets to more actively help hold the leaflets in place. Figures 11A to 11B The open position of the proximal element 16 is similar to that of the distal element 18, however, the proximal element 16 is now lowered toward the arm 53 by releasing the tension on the proximal element wire 90 to compress the proximal element 16 with the leaflet tissue of the arm 53. At any time, if regurgitation is not sufficiently reduced, the proximal element 16 can be raised and the distal element 18 adjusted or inverted to reposition the fixation device 14.

[0110] After the leaflets have been captured between the proximal and distal elements 16, 18 in the desired arrangement, the distal element 18 can be locked to hold the leaflets in that position, or the fixation device 14 can be returned or directed toward the closed position. This locking will be described in a later section. Figure 14 The fixture 14 is shown in a closed position in which the leaflets (not shown) are captured and engaged. This is achieved by proximally retracting the stud 74 relative to the coupling member 19, causing the legs 68 of the actuating mechanism 58 to apply an upward force to the distal element 18, which in turn rotates the distal element 18 so that the engagement surfaces 50 once again face each other. The released proximal element 16, which is biased outwardly toward the distal element 18, is simultaneously pushed inwardly by the distal element 18. As described below, the fixture 14 can then be locked to retain the leaflets in this closed position.

[0111] like Figure 15 As shown, the securing device 14 may then be released from the shaft 12. As described, the securing device 14 may be releasably coupled to the shaft 12 via the coupling member 19. Figure 15 86 .

[0112] In an exemplary embodiment, Figure 18 As shown, the proximal element wires 90 are elongated flexible threads, wires, cables, sutures, or threads that extend through the shaft 12, through the proximal element 16 in a loop, and back through the shaft 12 to the proximal end of the shaft 12. When detachment is desired, one end of each wire can be released at the proximal end of the shaft 12, and the other end pulled to pull the free end of the wire distally through the shaft 12 and through the proximal element 16, thereby releasing the fixation device. It will be appreciated that alternative methods and techniques for detachment may be used, for example, by releasing the distal second end of the proximal element actuator to disengage it from the anchor and retract the delivery catheter handle, as further described below, for example, and particularly Figure 22A .

[0113] Figure 16As shown, the coupling member 19 remains separated from the shaft 12 of the interventional tool 10 and the proximal element 16 is deployed so that tissue (not shown) can be located between the proximal element 16 and the distal element 18.

[0114] 17A to 17C The cover 100 is shown on the fixture 14 with the fixture 14 in various positions. Figure 17A When the device 14 is in the open position, the cover 100 is shown enclosing the distal element 18 and the actuation mechanism 58. Thus, the engagement surface 50 is covered by the cover 100, which helps to minimize trauma to the tissue and provides additional friction to help grasp and hold the tissue. Figure 17B Shown in an inverted position Figure 17A The cover 100 is loosely fitting and / or flexible or elastic so that the device 14 can be freely moved to various positions, and the cover 100 conforms to the contours of the device 14 and remains securely attached in all positions. Figure 17C The device 14 is shown in a closed position. Thus, when the fixation device 14 is left in the closed position as an implant, the exposed surface of the device 14 is substantially covered by the covering 100. It will be appreciated that the covering 100 can cover specific portions of the fixation device 14 while leaving other portions exposed. For example, the covering 100 can include a sleeve that is mounted on the distal element 18 rather than on the actuation mechanism 58, a cap that is mounted on the distal end 54 of the distal element 18, or a pad that covers the engagement surface 50, to name a few examples. It will be appreciated that the covering 100 can allow any friction attachments, such as barbs, to be exposed. In addition, the covering 100 can cover any other surface of the proximal element 16 and / or the fixation device 14. In any case, the covering 100 should be durable to withstand multiple introduction cycles and, when implanted in the heart, a lifetime of cardiac cycles.

[0115] The covering 100 may alternatively comprise a polymer or other suitable material that is impregnated, sprayed, coated, or otherwise adhered to the surface of the fixation device 14. Optionally, the polymer coating may include pores or contours that help grip tissue and / or promote tissue growth.

[0116] Any of the coverings 100 may optionally include a drug, antibiotic, antithrombotic, or antiplatelet agent such as heparin, (warfarin sodium), to name a few. These agents can be, for example, impregnated into the cover 100 or coated onto the cover 100. These agents can then be delivered to the tissue and / or bloodstream surrounding the grasped tissue to achieve a therapeutic effect.

[0117] B. Fixture locking mechanism

[0118] As previously mentioned, the fixing device 14 optionally includes a locking mechanism for locking the device 14 in a specific position such as an open, closed or inverted position or any position therebetween. It will be appreciated that the locking mechanism includes an unlocking mechanism that allows the device to be locked and unlocked. Figures 18 to 21 An embodiment of the locking mechanism 106 is shown. Figure 18 In this embodiment, the locking mechanism 106 is disposed between the coupling member 19 and the base 69 of the actuation mechanism 58. The base 69 is fixedly attached to a stud 74 that extends through the locking mechanism 106. The stud 74 is releasably attached to the actuator rod 64 that passes through the coupling member 19 and the shaft 12 of the interventional tool 10. The base 69 is also connected to the leg 68 of the actuation mechanism 58, which is in turn connected to the distal element 18.

[0119] Figure 18 Also shown is the proximal element 16, which in this embodiment straddles the locking mechanism and engages below the locking mechanism 106. The proximal element 16 is shown as being supported by a proximal element wire 90. The proximal element 16 is raised and lowered by manipulating the proximal element wire 90. In addition, a locking wire 92 is shown connected to a release harness 108 of the locking mechanism 106. As will be described below, the locking wire 92 is used to lock and unlock the locking mechanism 106. The proximal element wire 90 and the locking wire 92 can comprise any suitable material, typically a wire, a nitinol wire, a cable, a suture, or a silk thread, etc. In addition, the proximal element wire 90 and / or the locking wire 92 can comprise a coating such as parylene. Parylene is a conformal and biocompatible vapor-deposited, pinhole-free protective film. It is inert and protects against moisture, chemicals, and electrical charges.

[0120] Figure 19 Provided Figure 18 106 . However, here, the proximal elements 16 are supported by a single proximal element wire 90 that passes through both proximal elements 16. In this arrangement, both elements are raised and lowered simultaneously by the action of the single proximal element wire 90. Whether the proximal elements 16 are manipulated independently by separate proximal element wires 90 or collectively by a single proximal element wire 90, the proximal element wire 90 can extend directly through openings in the proximal elements and / or through a layer or portion of the covering 100 over the proximal elements, or through a sewing loop above or below the covering 100.

[0121] Figures 20 to 21 The locking mechanism 106 is shown in FIG. 1 , which shows the locking mechanism 106 in an unlocked position and a locked position, respectively. Figure 20, the locking mechanism 106 includes one or more wedging elements such as rolling elements. In this embodiment, the rolling elements include a pair of barbells 110 disposed on opposite sides of the stud 74, each barbell having a pair of generally cylindrical caps and a shaft between the caps. The barbells 110 and the stud 74 are preferably comprised of cobalt chromium alloy or stainless steel, however, any suitable material may be used. The barbells 110 are manipulated by the hooked end 112 of the release wire 108. When the locking wire 92 (at Figure 18 When an upward force is applied to the harness 108, the hooked end 112 causes the barbell 110 to rise against the spring 114, as shown. Figure 20 This pulls the barbell 110 upward along the sidewall or inclined surface 116, thereby releasing the barbell 110 from abutting the stud 74. In this position, the stud 74 is free to move. Thus, when the locking wire 92 raises or elevates the harness 108, the locking mechanism 106 is in the unlocked position, in which the stud 74 allows the actuating mechanism 58 and, therefore, the distal element 18, to move freely to any desired position. Releasing the harness 108 by the locking wire 92 causes the locking mechanism 106 to transition to the locked position, as shown. Figure 21 As shown in FIG. By releasing the upward force on the barbell 110 by the hooked end 112, the spring 114 forces the barbell 110 downward and wedges it between the inclined surface 116 and the stud 74. This restricts the movement of the stud 74, thereby locking the actuation mechanism 58 and, consequently, the distal element 18 in place. Furthermore, the stud 74 may include one or more grooves 82 or indentations that receive the barbell 110. This can provide a faster and more positive locking by securing the barbell 110 in a defined position, increase the stability of the locking feature by further preventing movement of the barbell 110, and provide a tangible indication to the user that the barbell has reached the locked position. Furthermore, the grooves 82 can be used to indicate the relative position of the distal elements 18, particularly the distance between the distal elements 18. For example, each groove 82 can be positioned to correspond to a 0.5 mm or 1.0 mm decrease in the distance between the distal elements 18. As the stud 74 moves, the barbell 110 contacts the grooves 82; by counting the number of grooves 82 felt as the stud 74 moves, the user can determine the distance between the distal elements 18 and provide a desired degree of coaptation based on leaflet thickness, geometry, spacing, blood flow dynamics, and other factors. Thus, the grooves 82 can provide tactile feedback to the user.

[0122] The locking mechanism 106 allows the fixation device 14 to remain in an unlocked position when attached to the interventional tool 10 during grasping and repositioning and then remain in a locked position when left as an implant. However, it will be appreciated that, if desired, the locking mechanism 106 can be repeatedly locked and unlocked throughout the placement of the fixation device 14. Once final placement is determined, the locking wire 92 and the proximal element wire 90 are removed and the fixation device is left behind.

[0123] While the embodiments of the present invention described above utilize a push-to-open, pull-to-close mechanism for opening and closing the distal element 1, it should be understood that a pull-to-open, push-to-close mechanism is equally feasible. For example, the distal element 18 can be coupled at its proximal end to the stud 74 rather than to the coupling member 19, and the legs 68 can be coupled at their proximal ends to the coupling member 19 rather than to the stud 74. In this example, when the stud 74 is pushed distally relative to the coupling member 19, the distal element 18 will close, while pulling the stud 74 proximally toward the coupling member 19 will open the distal element 18.

[0124] C. Individual Actuation of Proximal Elements

[0125] In another embodiment, reference Figure 9 , actuation of the proximal element 16 can be achieved by using one or more proximal element wires or actuators 90. Such actuation can be achieved in various ways. For example, Figure 22A As shown, the proximal element actuators 90A and 90B can be inserted through the wire loops 48A and 48B provided on the radially outward proximal sides of the proximal elements 16A and 16B, respectively. The distal ends of the proximal element actuators 90A and 90B can include closed loops 95A and 95B that surround the proximal elements 16A and 16B. Figure 22A , the shaft 12 and the coupling member 19 coupled together as shown in . As described above, the shaft 12 and the coupling member 19 can be coupled together in a releasable manner. In order for the closed loops 95A and 95B to surround the shaft 12 and the coupling member 19, the closed loops 95A and 95B are placed on the shaft 12 and / or the coupling member 19 before the coupling shaft 12 and the coupling member 19 are connected together. When the closed loops 95A and 95B surround the shaft 12 and the coupling member 19, the closed loops 95A and 95B hold the distal ends of the proximal element actuators 90A and 90B in place relative to the shaft 12 and the coupling member 19 and limit the extent to which the proximal element actuators 90A and 90B can be retracted. The proximal element actuators 90A and 90B are mechanically connected to the proximal elements 16A and 16B, respectively, by passing through the wire loops 48A and 48B. Thus, as Figure 23As shown, when proximal element actuators 90A and 90B are proximally retracted in direction 96, proximal element actuators 90A and 90B move proximal elements 16A and 16B, respectively, away from distal elements 18A and 18B. Similarly, pushing proximal element actuators 90A and 90B distally moves proximal elements 16A and 16B toward distal elements 18A and 18B.

[0126] In another embodiment, in order to enable proximal element actuators 90A and 90B to pull proximal elements 16A and 16B proximally and push proximal elements 16A and 16B distally, each of proximal element actuators 90A and 90B can be configured to have a thin wire portion 90D and a thick wire portion 90E. Thin wire portion 90D extends from rings 48A and 48B to thick wire portion 90E. The thin wire portion 90D can retract proximal element actuators 90A and 90B through wire rings 48A and 48B when the proximal element actuators are pulled proximally. On the other hand, thick wire portion 90E has a stiffness that prevents these portions of proximal element actuators 90A and 90B from passing through rings 48A and 48B because the stiffer section does not easily bend to form the bend required to extend through rings 48A and 48B toward shaft 12. Thus, when proximal element actuators 90A and 90B are urged to a position where thick wire portion 90E reaches loops 48A and 48B, proximal element actuators 90A and 90B serve to urge proximal elements 16A and 16B toward distal elements 18A and 18B, respectively.

[0127] Figure 59A and 59B An embodiment is shown in which a thick wire portion 90E is formed by rolling the end of a circular thin wire portion 90D. In particular, the rolling of the circular portion of the wire produces a cross section having a thick portion T3 formed as a result of the rolling so that the circular segment thickness T1 is reduced to a thickness T2. This results in a cross section having a substantially rectangular shape with dimensions T2 and T3. Notably, T3 is greater than T1, and T2 is less than T1. Due to this flattening of the ends of the proximal element actuators 90A and 90B, the bending characteristics of the end portions are changed. That is, under compressive loads, the bend will tend to follow the Figure 59A The plane is generated instead of Figure 59B The rounded portion (thin) may have a diameter in the range of 0.009 to 0.012 inches and the thick portion may have a width in the range of 0.013 to 0.02 inches. Figure 60A and Figure 60B As shown, the proximal element actuators 90A and 90B may be formed from a plurality of thick sections that thicken toward the distal end of the actuator. Figure 60B As shown, TA <TB<TC<TD。

[0128] In such Figure 22B In another embodiment shown, as an alternative to using a thick / thin wire combination, proximal element actuators 90A and 90B can include thin wires housed within outer tube 90G. In this embodiment, rather than relying on a stiffer thick wire portion, the proximal element actuators include outer tube 90G to push proximal elements 16A and 16B distally. Outer tube 90G can comprise, for example, a braided polyamide tube.

[0129] By using a thick wire portion or outer tube, a greater force can be used to push or position the proximal elements 16A and 16B distally toward the distal element. In contrast, when configured, such proximal elements 16A and 16B are biased to extend distally to combine only with the thin wire proximal element actuators 90A and 90B, and the engagement force between the proximal elements 16A and 16B and the distal elements 18A and 18B increases as the distal elements move distally, i.e., as shown in FIG. Figure 3B However, when thick wire portions or outer tubes are introduced into the proximal elements 16A and 16B, greater force can be used to push the proximal elements distally. This provides more control and better positioning for capturing the leaflets during coaptation. In addition, when there is a relatively large gap between the leaflets, such as Figure 3B As shown, extending the distal elements in a 180-degree alignment enables the system to more easily capture the leaflets at this gap or interval. In addition, the ability to push proximal elements 16A and 16B to engage distal elements 18A and 18B within this range (120 to 180 degrees or greater) provides a responsive and improved geometry for leaflet capture.

[0130] Proximal element actuators 90A and 90B can be moved to move proximal elements 16A and 16B relative to distal elements 18A and 18B at various angles and distances. Furthermore, the degree to which proximal element actuators 90A and 90B are pushed or pulled can be maintained to maintain the position of proximal elements 16A and 16B relative to distal element 18. For example, Figure 24 As shown, proximal element actuators 90A and 90B are pulled proximally and held in the position shown to maintain proximal elements 16A and 16B in an intermediate position relative to distal element 18. Figure 23 As shown, the intermediate position is between the position toward which the proximal elements 16A and 16B are biased and the position in which the proximal elements 16A and 16B are fully retracted. Figure 27As shown, once proximal elements 16A and 16B are in the desired position, shaft 12 and coupling member 19 can be decoupled such that proximal element actuators 90A and / or 90B are proximally retracted to decouple the proximal element wires from proximal element 16. Thus, fixation device 14 can remain in place while shaft 12, proximal element actuators 90A and 90B, and other parts can be removed from the operative site. Figure 28 As shown, the fixing device 14 generally includes the following 17A to 17C Essentially the same covering 100 discussed in .

[0131] It may be desirable to provide independent actuation mechanisms for proximal elements 16A and 16B. Figure 25 As shown, proximal element actuator 90A retracts proximally and proximal element 16A rotates away from distal element 18A, while proximal element actuator 90B pushes distally and proximal element 16B rotates toward distal element 18B. Figure 26 8B. As shown, proximal element actuator 90A is not interfered with, thereby allowing proximal element 16A to remain in the position toward which proximal element 16A is biased, while proximal element actuator 90B is retracted proximally, thereby moving proximal element 16B away from distal element 18B. Providing independent actuation mechanisms for proximal elements 16A and 16B allows the leaflets to be grasped independently by proximal elements 16A and 16B and distal elements 18A and 18B. As a result, fixation device 14 can more easily and at a more ideal position to bring the leaflets into apposition. For example, as opposed to grasping both leaflets simultaneously, a first leaflet can be grasped at a desired position and fixation device 14 can then be repositioned so that the second leaflet can be grasped at a more ideal position.

[0132] Reference is made for purposes of illustration and not limitation Figures 61 to 64B , various etiologies of mitral regurgitation may benefit from either individual or sequential leaflet capture. For example, Figure 61 A heart with functional mitral regurgitation is shown with a restricted and short posterior mitral leaflet (PML). Simultaneous capture of the anterior mitral leaflet (AML) and the PML can be difficult due to one or more of the restricted mobility of the PML, the short length of the PML, the wide gaps between the leaflets, and the high tension forces transmitted by the valve's underlying structures, such as the chordae tendineae and associated papillary muscles. Independent leaflet capture can be used to (1) capture the PML first without worrying about capturing the AML simultaneously (2) Figure 62A ), (2) gradually repositioning the catheter to the position for capturing the AML while maintaining capture of the PML ( Figure 62B ), and (3) capture the AML. This order can be reversed or adjusted based on the operator's observation of which leaflet is more challenging or particularly static during the cardiac cycle.

[0133] For example, Figures 63A to 63B A heart with a flail case of degenerative mitral regurgitation is shown, where the PML flailed excessively but the AML chordae tendineae were intact. In this case, the AML with intact chordae tendineae moved more centrally under systolic pressure due to the angulation of the AML edges ( Figure 63A ). Thus, during the systolic phase, as the leaflet edges move inward and deeper into the implantable fixation device 14 (not shown) positioned between the leaflets, AML capture can be easier and more effective. However, during systolic phase, the flailed PML is untethered from the chordae tendineae and can flail uncontrollably into the left atrium. Thus, capture of the PML leaflets is more challenging during the systolic phase of the cardiac cycle. In contrast, during the diastolic phase ( Figure 63B ), the flail's PML can be pushed downward. This position can more easily capture the maximum amount of leaflets. Therefore, in this case, AML capture can be performed during systole ( Figure 64A ), and PML capture can be performed during diastole ( Figure 64B ).

[0134] Alternatively, the leaflets can still be grasped simultaneously if desired because the independently actuatable proximal element actuators can still be moved simultaneously. Furthermore, if, for example, the leaflets were incorrectly approximated during the first grasp, after the leaflets are grasped, they can be released and the leaflets can be grasped again. The described embodiments can be used with either the S-lock configuration or the I-lock configuration described herein.

[0135] An embodiment of a fixation device similar to the one described above may include both a clamp pusher 81 and independently actuatable proximal elements 16A and 16B, such as Figure 28 Having both a gripper pusher 81 and independently actuatable proximal elements 16A and 16B can allow the fixation device to have many of the advantages described above, such as more accurate and stronger grasping of the leaflets.

[0136] In another embodiment, the proximal element actuators 90A and 90B may each include a Figure 18 302. Figures 29 to 33 As shown, proximal element actuators 90A and 90B may be coupled with release wires 108 so that locking wires 92 may be eliminated.

[0137] Figure 29A configuration is shown in which proximal element actuator 90A loops through release harness 108 and the end of proximal element 16A. Another proximal element actuator 90B loops through only proximal element 16B. Thus, in this embodiment, manipulation of proximal element actuator 90A proximally or distally actuates proximal element 16A into or out of engagement with tissue. After tissue engagement is complete and the leaflets are properly apposed, proximal element actuator 90A can be further actuated to release release harness 108 of locking mechanism 106. On the other hand, if it is determined that fixation device 14 requires repositioning, applying tension to proximal element actuator 90A unlocks the locking mechanism. Further actuation of proximal element actuator 90A can then disengage proximal element 16A from the leaflets, allowing for repositioning.

[0138] In another embodiment, Figure 30 As shown, proximal element actuators 90A and 90B can be configured to cross with the shaft 12 to provide better leverage for actuation. Likewise, in this configuration, proximal element actuator 90A passes through the release harness 108 and the end of proximal element 16A in a looped manner. The other proximal element actuator 90B passes through only proximal element 16B in a looped manner. However, crossing the shaft in this manner changes the angular relationship between the points at which proximal element actuators 90A and 90B exit the nose 318 of the shaft 302 and the points at which they connect to the respective proximal elements 16A and 16B. Thus, in a configuration such as Figure 29 With a given amount of tension on the proximal element actuators 90A and 90B in the configuration shown, the resultant force of actuation on the proximal elements 16A and 16B is increased. This arrangement also allows for the elimination of the locking wire 92. Figure 29 As shown, each of the proximal element actuators 90A and 90B can straddle the shaft 12. However, the wires can also be routed to cross on the same side of the shaft 12.

[0139] Figure 31 Another configuration for wiring proximal element actuators 90A and 90B is shown. In this configuration, proximal element actuators 90A and 90B are each coupled to one of proximal elements 16A and 16B and release harness 108. Although Figure 30 The embodiment shown locks the fixation device 14 only after the proximal element 16A is moved into engagement with the leaflet, but Figure 31 The configuration permits the operator to control the order in which the leaflets engage between proximal element 16A and proximal element 16B. In other words, in the event that the operator chooses to actuate only proximal element 16B, proximal element actuator 90A does not need to be actuated after locking fixture 14.

[0140] Figure 32 and Figure 33 Another possible configuration for proximal element actuators 90A and 90B is shown. Each proximal element actuator includes a loop that exits from nose 318 and returns to nose 318. However, in this case, proximal element actuators 90A and 90B are each double-wired through the end of a corresponding one of proximal elements 16A and 16B and then looped around release harness 108. Figure 32 16A, and proximal element actuator 90B exits nose 318 on a side of nose 318 adjacent to proximal element 16B. In an alternative configuration, proximal element actuator 90A exits nose 318 on a side of nose 318 opposite proximal element 16A, and proximal element actuator 90B exits nose 318 on a side of nose 318 opposite proximal element 16B. Intersecting the axis in this manner changes the angular relationship between the points at which proximal element actuators 90A and 90B exit nose 318 of shaft 302 and the points at which proximal element actuators 90A and 90B connect to respective proximal elements 16A and 16B. Thus, at a given amount of tension on proximal element actuators 90A and 90B, the net force of actuation on proximal elements 16A and 16B is increased.

[0141] exist Figures 29 to 33 In each of the embodiments of the present invention, each of the proximal element actuators 90A and 90B can be formed from a single wire, which can be formed from a single or multiple wires extending from the nose 318 of the shaft 302 and returning to the nose 318 of the shaft 302. However, in Figure 32 and Figure 33 In an embodiment, the proximal element actuators 90A and 90B may extend only from the nose 318 and then terminate at Figure 24 The coupling shaft 12 or coupling member 19 is shown.

[0142] D. Individual actuation of proximal elements / single actuators

[0143] In other embodiments, continuous gripping can be achieved using a single actuator. Figure 34A configuration is shown in which a single proximal element actuator 90 having a proximal end and a distal end extends from the nose 318 of the shaft 302 to one of the proximal elements 16A. The single proximal element actuator 90 can be looped through an eyelet at the distal end of the proximal element 16A or retained by a suture at the same location. The same proximal element actuator 90 then extends across the coupling shaft 12 to the other proximal element 16B where it is coupled to the distal end of the proximal element 16b in a manner similar to the proximal element 16A. The distal end of the proximal element actuator 90 extends to either the coupling shaft 12 or the coupling member 19 and is secured thereto. Figure 34 In the embodiment, the proximal element actuator 90 is fastened using a ring. However, the proximal element actuator can be releasably fixed to the fixing device 14 according to any of the embodiments disclosed below.

[0144] By virtue of the geometry of this configuration, each proximal element 16A and 16B can be independently actuated, and the proximal element actuator 90 can be released as the coupling member 19 separates. Figure 35 As shown, due to the wiring arrangement of the proximal element actuator 90, the resultant forces F1 and F2 have different angles. These resultant forces and their directions are based on the tension on the proximal element 90 and the direction (angle) at which the proximal element actuator 90 approaches and extends away from the corresponding proximal element 16A or 16B. The force that moves the corresponding proximal element is the component of the force that is perpendicular to the length of the corresponding proximal element. This perpendicular component is represented by FN1 and FN2. Smaller angles (θ1, θ2) between the resultant forces and the perpendicular components result in larger perpendicular components. As shown in FIG. Figure 35 As shown, because angle θ1 is smaller than angle θ2, vertical component FN1 will be greater than vertical component FN2. Therefore, for a given amount of tension in proximal element actuator 90, proximal element 16A will receive more movement force than proximal element 16B. This means that proximal element 16B will remain closed while proximal element 16A is open, and will open after proximal element 16A is fully open. This allows proximal elements 16A and 16B to be independently actuated using a single proximal element actuator 90.

[0145] E. Clamp Pusher for Engaging Proximal Elements

[0146] In some cases, the leaflets may become completely or partially separated from the fixture due to poor insertion between the proximal and distal elements. Therefore, standard imaging techniques, such as echocardiography and fluoroscopy, are used to assess the insertion depth of the leaflets into the fixture or to distinguish between the leaflets and the proximal and distal elements of the fixture. However, depending on the angle and / or position of the proximal and distal elements relative to the delivery catheter, assessing the depth of leaflet insertion into the fixture or distinguishing between the leaflets and the proximal and distal elements of the fixture can be challenging. Therefore, visualization is preferably performed with the distal elements in a further open configuration in which the distal elements are displaced relative to each other. However, because many existing embodiments of the fixture only allow the proximal elements to open to an angle of approximately 85°, the distal elements must be closed to an angle of approximately 45°, and preferably 60°, between them to securely grasp the leaflets between the proximal and distal elements. While this configuration helps the operator visualize and distinguish between the leaflets and the fixture, it is preferable to further open the distal elements to an angle greater than 90°, and more preferably to an angle of 120° or greater. Therefore, it would be desirable to modify the proximal elements to open further.

[0147] Figures 36 to 40 Shown with Figures 7A to 14 The device is similar to an embodiment of the fixing device, the main difference being that this embodiment includes a clamp pusher. Figure 36 A fixture 14 is shown which generally takes the same form as the fixture 14 previously described. In addition to the features previously described, the fixture 14 further includes a clamp pusher 81. The clamp pusher 81 deflects radially outwardly to provide an arcuate region 83 which expands outwardly until the arcuate region 83 engages the upper surface of the proximal element 16. As the arcuate region 83 continues to deflect radially outwardly, the arcuate region 83 further pushes the proximal element 16 such that the proximal element deflects and rotates outwardly toward the engagement surface of the distal element 18. Thus, the proximal elements 16 can be deflected further outwardly than they would normally be deflected and, therefore, the leaflets can be captured between the proximal and distal elements when the distal elements are positioned in a more open position having a larger angle therebetween. In a preferred embodiment, the angle between the distal elements is greater than about 90°, preferably greater than about 110°, and more preferably greater than about 120°. In Figure 36In an embodiment, the clamp pusher 81 includes two arms formed from a metal, polymer, or other linear material. Exemplary materials include cobalt chromium, stainless steel, nickel titanium, etc. Polymers can also be used to manufacture the clamp pusher. When an axially directed compressive force is applied that is substantially parallel to the longitudinal axis of the clamp pusher arms, the clamp pusher 81 can be actuated to bend outward. During compression, the clamp pusher bends outward to form an arcuate region 83. In other embodiments, the clamp pusher can be a spring that is elastically biased to bend outward to form the arcuate region 83. However, when the proximal element wire (not shown here) is tightened to lift the proximal element 16, the clamp pusher spring will telescope to a reduced profile.

[0148] Figure 37 The fixation device 14 is shown with a covering for tissue ingrowth, and wherein the clamp pusher 81 is expanded to engage the proximal element 16 (also referred to as the clamping element) with the distal element 18 (also referred to as the fixation element). The leaflets (not shown for convenience) are clamped between the proximal element 16 and the distal element 18. Figure 38 Clip pusher 81 is shown in a telescoping configuration. Arcuate region 83 telescoping allows proximal element 16 to be retracted toward shaft 12, thereby allowing the leaflets (not shown) to be released from fixation device 14. Clip pusher 83 is offset relative to proximal element 16 so that the proximal element can be retracted without interfering with clip pusher 81.

[0149] Figure 39 The clamp pusher 83, which preferably includes two spring arms 99, is highlighted. Each arm 99 is formed from wire or machined from sheet material or other raw material and has a rectangular cross-section in this embodiment, but other cross-sections are also contemplated. The distal portion 91 of each arm 99 has a notched area 93 formed with a pair of fingers that can engage with bosses or other attachment mechanisms on the fixture 14. The notches can be released from the bosses when the fixture 14 is separated from the delivery catheter shaft 12. In addition, each arm includes two arcuate regions or peaks, including a larger distal arcuate region 83 and a smaller proximal arcuate region 95. The larger arcuate region 83 flares outward a greater distance to engage the proximal element 16 and urge the proximal element 16 into engagement with the distal element 18. When the distal arcuate region 83 relaxes and telescopes away from the proximal element 16, or when telescoped due to retraction of the proximal element, the smaller proximal arcuate region 95 expands radially outward. An attachment ring or coupling collar 97 is adjacent the nose 318 (described in more detail below) and is slidably disposed on the shaft 12 and allows the clamp arm 99 to be coupled to the shaft 12 . Figure 40The distal arcuate region 83 is shown engaging the proximal element 16 , and the notch 93 on the distal portion of each arm 99 is also shown engaging a boss 94 on the fixture 14 .

[0150] As described above, for example, with reference to Figures 10A to 11B , actuation of the proximal element 16 may be accomplished using one or more proximal element wires or actuators 90. In another embodiment, the actuation may be accomplished by a combination of the proximal element actuator 90 and the gripper pusher 81 as described above. For example, Figure 41 As shown, proximal element actuators 90A and 90B may pass through wire loops 48A and 48B disposed on radially outward proximal sides of proximal elements 16A and 16B, respectively. The distal ends of proximal element actuators 90A and 90B may include a loop around Figure 41 , which are shown in FIG. 1 . The closed loops 95A and 95B of the shaft 12 and the coupling member 19 coupled together are shown in FIG. As discussed above, the shaft 12 and the coupling member 19 can be coupled together in a releasable manner. In order for the closed loops 95A and 95B to surround the shaft 12 and the coupling member 19, the closed loops 95A and 95B are placed on the shaft 12 and / or the coupling member 19 before the shaft 12 and the coupling member 19 are coupled together. When the closed loops 95A and 95B surround the shaft 12 and the coupling member 19, the closed loops 95A and 95B hold the distal ends of the proximal element actuators 90A and 90B in place relative to the shaft 12 and the coupling member 19 and limit the extent to which the proximal element actuators 90A and 90B can be retracted. The proximal element actuators 90A and 90B are mechanically connected to the proximal elements 16A and 16B, respectively, by passing through the wire loops 48A and 48B. Thus, as Figure 42 As shown, when proximal element actuators 90A and 90B are proximally retracted in direction 96, proximal element actuators 90A and 90B move proximal elements 16A and 16B away from distal elements 18A and 18B, respectively.

[0151] However, in a combination of proximal element actuators 90A and 90B that permit independent actuation of proximal elements 16A and 16B, gripper pusher 81 can also be included in the fixture. Thus, proximal elements 16A and 16B can be deflected further outward than they normally would, and thus, the leaflets can be captured between the proximal and distal elements when the distal element is positioned in a more open position with a larger angle therebetween. In a preferred embodiment, the angle between the distal elements is greater than approximately 90°, preferably greater than approximately 110°, and more preferably greater than approximately 120°. Thus, in this embodiment, the fixture enables independent actuation and a wide range of movement of proximal elements 16A and 16B.

[0152] Proximal element actuators 90A and 90B can be moved to move proximal elements 16A and 16B to various angles and distances from distal elements 18A and 18B. Furthermore, the degree to which proximal element actuators 90A and 90B are pushed or pulled can be maintained to maintain the position of proximal elements 16A and 16B relative to distal element 18. For example, Figure 43 As shown, proximal element actuators 90A and 90B are pulled proximally and held in the position shown to maintain proximal elements 16A and 16B in an intermediate position relative to distal element 18. This intermediate position is similar to the position toward which proximal elements 16A and 16B are biased. Figure 42 The proximal elements 16A and 16B are shown between their fully retracted positions. Figure 46 As shown, once proximal elements 16A and 16B are in the desired position, shaft 12 and coupling member 19 can be decoupled such that proximal retraction of proximal element actuators 90A and / or 90B decouples the proximal element wires from proximal element 16. Thus, fixation device 14 can remain in place while shaft 12, proximal element actuators 90A and 90B, and other parts can be removed from the operative site. Figures 41 to 47 As shown, the securing device 14 generally includes a covering 100 .

[0153] It may be desirable to provide independent actuation mechanisms for proximal elements 16A and 16B. Figure 44 As shown, proximal element actuator 90A retracts proximally and proximal element 16A rotates away from distal element 18A, while proximal element actuator 90B pushes distally and proximal element 16B rotates toward distal element 18B. Figure 45 As shown, proximal element actuator 90A is not interfered with, thereby allowing proximal element 16A to maintain the position toward which proximal element 16A is biased, while proximal element actuator 90B is proximally retracted, thereby moving proximal element 16B away from distal element 18B.

[0154] In another embodiment, Figure 47 As shown, with Figure 46 The independent actuation of the proximal elements 16A and 16B is performed in a similar manner to the embodiment described in Figure 47 As shown, proximal element actuators 90A and 90B are formed of a double loop configuration. Each proximal element actuator 90A and 90B exits through nose 318 of shaft 302 and returns through nose 318 of shaft 302 after being routed through the distal end of a corresponding one of proximal elements 16A and 16B and around shaft 12 or coupling mechanism 19 in a looped manner. This configuration provides for a dual loop configuration. Figure 46, but permits removal of the proximal element actuators 90A and 90B before the coupling mechanism 19 is released from the shaft 12.

[0155] In such Figure 48 In another embodiment shown, a single proximal element actuator 90 is configured to Figure 34 However, this embodiment also uses the gripper pusher 81 to provide an expanded range of movement of the distal elements 18A and 18B in the opening direction. By virtue of the geometry of this configuration, each proximal element 16A and 16B can be independently actuated, and the proximal element actuator 90 can be released as the coupling member 19 separates. Figure 35 As shown, due to the wiring arrangement of proximal element actuator 90, the resultant forces F1 and F2 are at different angles. These resultant forces and their directions are based on the tension on proximal element 90 and the direction (angle) at which proximal element actuator 90 approaches and extends away from the corresponding proximal element 16A or 16B. Similarly, the force that moves the corresponding proximal element is the component of the force perpendicular to the length of the corresponding proximal element. These perpendicular components are represented by FN1 and FN2. Therefore, for a given amount of tension in proximal element actuator 90, proximal element 16A will receive more moving force than proximal element 16B. This means that proximal element 16B will remain closed when proximal element 16A opens, and will open after proximal element 16A is fully opened. This allows for independent actuation of proximal elements 16A and 16B using a single proximal element actuator 90. Furthermore, in this embodiment, the angle between the distal elements can be greater than approximately 90°, preferably greater than approximately 110°, and more preferably greater than approximately 120°. Thus, in this embodiment, the fixation device can be used for independent actuation and a wide range of movement of the proximal element.

[0156] F. Proximal Element Actuator Connection

[0157] In many of the embodiments described above, proximal element actuator 90, or proximal element actuators 90A and 90B, include an end that can be releasably coupled to fixation device 14. The various embodiments described below illustrate various methods and structures for releasably coupling a proximal element actuator that can be applied to any of the embodiments described above.

[0158] In many embodiments, the shaft 12 and the coupling member 19 are releasably coupled together via an L-shaped locking mechanism. Figure 49A As shown, the proximal element actuator 90 may include a rounded T-shaped end 90T located distal to the flat section 90F, and the shaft 12 may include an L-shaped end 12L. Figure 49B , when the proximal element actuator 90 and the shaft 12 are placed in the channel 19C of the coupling member 19, the proximal element actuator 90 is releasably coupled to the coupling member 19. When the shaft 12 is placed through the channel 19C, the L-shaped ends 12L are pushed inward until they reach the aperture 19A. At this point, the L-shaped ends 12L expand outward to fit into the aperture 19A, thereby locking the shaft 12 in place relative to the coupling member 19, as shown in FIG. Figure 49C The round T-shaped distal end 90T will typically be placed in the space 19CA before the shaft 12 is placed in the channel 19C. Figure 49C As shown, when the shaft is placed in channel 19C, the rounded T-shaped distal end 90T is then trapped in the space or pocket 19CA between channel 19C and the wider portion of shaft 12. Other L-shaped locking mechanisms or other locking mechanisms are described in commonly assigned U.S. patent application Ser. No. 12 / 393,452, entitled “Detachment Mechanism for Implantable Fixation Devices,” filed Feb. 26, 2009, the entire contents of which are incorporated herein by reference.

[0159] The rounded T-shaped end 90T of the proximal element actuator 90 can also be used to facilitate releasable coupling of the proximal element wire 90 to the shaft 12 and coupling member 19 in many other ways. For example, Figure 50A As shown, the L-shaped end portion 12L of the shaft 12 may include at least one proximal element wire groove 12S. Figure 50C and Figure 50D As shown, the T-shaped end 90T of the proximal element actuator 90 is slid into the proximal element wire groove 12S. The shaft 12 is then placed in the coupling member 19, thereby also locking the proximal element wire 90 in place. Figure 50E As shown, removing shaft 12 from coupling member 19 allows proximal element wire 90 to slide out of proximal element wire slot 12S of L-shaped end 12L, thereby decoupling proximal element actuator 90 from both shaft 12 and coupling device 19 .

[0160] like Figure 51A As shown, the proximal element actuator 90 may include a flat T-shaped end 90TF. The shaft 12 may also include an inner distal cover 1511 surrounding the distal portion of the shaft 12 and an outer distal cover 1521 surrounding the inner distal cover. The inner distal cover 1511 will generally be in a fixed position relative to the shaft 12, while the outer distal cover will be movable relative to the shaft 12 within a range determined by a protrusion 1515 of the inner distal cover 1511 positioned through a side channel 1525 of the outer distal cover 1521. Figure 51B As shown, in order to releasably couple the proximal element actuator 90 to the shaft 12 and the coupling line 19, the T-shaped end portion 90TF is fitted into the T-shaped cutout 1513 of the inner distal cover 1511, and when the shaft 12 is placed in the coupling device 19, the coupling device 19 pushes the outer distal cover 1521 onto the inner distal cover 1511 to cover the T-shaped cutout 1513 and the T-shaped end portion 90TF. This compresses the coil spring 1522 placed between the inner distal cover 1511 and the outer distal cover 1521. When the fixing device 14 is released from the shaft 12, the outer distal cover 1521 moves distally due to the action of the coil spring 1522 to expose the T-shaped cutout 1513 and thereby release the proximal element actuator. In some embodiments, the outer distal cover 1521 can be spring-loaded against the inner distal cover 1523 so as to tend to maintain Figure 51B Their relative positions are shown in .

[0161] For example, Figures 52A to 52G As shown, the proximal element actuator 90 may be releasably coupled to the fixation device 14 in a variety of ways by using variations of inner and outer distal collars on the distal portion of the shaft 12 . Figure 52A An inner distal collar 1511A is shown having a pair of T-shaped cutouts 1513 and a protrusion 1514 . Figure 52B An outer distal collar 1521A is shown having a channel 1524. For example, Figures 52C to 52E As shown, when the inner distal collar 1511A slides into the outer distal collar 1521A, the channel 1524 guides the inner distal collar 1511A via the protrusion 1514 of the inner distal collar 1511A. Figure 51A and Figure 51B In the illustrated embodiment, to releasably couple the proximal element actuator 90 to the shaft 12 and the coupling member 19, the T-shaped end portion 90TF fits into the T-shaped cutout 1513 of the inner distal collar 1511S. Figure 52F and Figure 52G As shown, when the shaft 12 is placed in the coupling member 19, the coupling member 19 pushes the outer distal collar 1521S onto the inner distal collar 1511S to cover the T-shaped cutout 1513 and the T-shaped end 90TF. This compresses the Figure 52C When the fixing device 14 is released from the shaft 12, the outer distal cover 1521A moves distally due to the action of the coil spring 1522A to expose the T-shaped cutout 1513A and thus release the proximal element actuator 90.

[0162] In other embodiments, the proximal element actuator 90 may be releasably engaged with a structure that is activated by removing the actuator rod 64 through the coupling member 19 and the shaft 12. Figure 53 As shown, a stud 74 is releasably attached to an actuator rod 64 that passes through the coupling member 19 and shaft 12 of the interventional tool 10. In this manner, the actuator rod 64 can be connected to the fixation device and used to manipulate the fixation device, typically to open and close the distal element. After the leaflets have been approximated, the actuator rod 64 is removed proximally from the stud 74 to release the coupling member 19, or alternatively, to release the L-shaped locking mechanism described above. In the following embodiments, this action of the actuator rod 64 can be used to release the proximal element actuator 90.

[0163] In one embodiment, Figures 54A to 54D as well as Figures 55A to 55C As shown, spring member 331 is used in combination with actuator rod 64 to retain and release proximal element actuator 90. Figure 54A As shown, a portion of the shaft extending from the nose 318 has two windows 333 formed therein. Two spring members are positioned on the periphery of the shaft 12 adjacent the corresponding windows so that curved portions 335 extend into the actuator rod path formed within the shaft 12. The proximal sides of these curved portions 335 can be fixed to the nose 318 or an outer portion of the shaft 12. The distal side of each curved portion 335 is attached to a "C"-shaped portion having a notch 339 formed at each end of the "C". The corresponding end portion of one "C"-shaped portion on one spring is configured to abut the end portion of the other spring so that the corresponding notch 339 can limit the movement of the ball 337 at the end of either proximal element actuator. Figure 54C The location where the "C" shaped portions contact to form a notch that prevents the distal end of the ball 337 from moving is shown.

[0164] like Figure 55A As shown, the actuator rod 64 is configured to have a tapered profile with a narrow portion and a wide portion. Figure 55B , when the actuator rod 64 moves proximally, the wide portion of the actuator rod 64 contacts the curved portion 335 to separate the corresponding "C" shaped portions of the adjacent spring members 331. This opens the notch 339 so that the ball 337 of the proximal actuator 90 is released, as shown in FIG. Figure 55C shown.

[0165] In such Figure 56A and Figure 56BIn another embodiment shown, proximal element actuator 90 or proximal element actuators 90A and 90B can be releasably attached to shaft 12 by using one or a set of pads 65 that are hingedly attached to shaft 12. In this configuration, a pair of windows 33 are formed in shaft 12 (only one window is required in the case of a single proximal element actuator). Pads are hingedly attached to the inside of shaft 12 on the proximal side of each of the windows 33. Figure 56A As shown, when the actuator rod 64 is withdrawn from the proximal end, the pad 65 moves inwardly so that the proximal element actuator 90 can move freely. When the actuator rod 64 is in this position, the proximal element actuator 90 can be inserted into or withdrawn from the window 33. On the other hand, as shown in FIG. Figure 56B As shown, when the actuator rod 64 is moved distally, the pads 65 are pressed outwardly against the interior surface of the shaft 12 to trap or clamp the proximal element actuator. This secures the proximal element actuator so that the proximal element 16 can move independently. The proximal element actuator 90 is fixed to the shaft 12 until the actuator rod 64 is moved proximally again. Figure 56A to the position shown in .

[0166] Reference Figures 65A to 65I For purposes of illustration and not limitation, actuator rod 64 can be used as an anchor to limit the proximal movement of proximal element actuators 90A and 90B. As disclosed above, the second ends (e.g., distal end portions) of proximal element actuators 90A and 90B can each include a stop element, such as ball 337A (see Figure 65F ) or other shapes, such as a trumpet-shaped portion 338A having a conical shape (see Figure 65D ), the catch element can be sized to be received within the shaft 12. Figures 65A to 65CAs shown, a portion of the shaft 12 extending from the nose 318 and proximal to the L-shaped end 12L of the L-lock may have two slots 401A and 401B defined therein. Slot 401A may define holes 402A and 402B, and slot 401B may define holes 402C and 402D. Holes 402A and 402C may be sized to receive flares 338A and 338B (not shown) passing through holes 402A and 402C, respectively, and into slots 401A and 401B, respectively. Holes 402B and 402D may be sized to prevent flares 338A and 338B from extending beyond slots 401A and 401B, respectively. The configuration of slots 401A and 401B and holes 402A through 402D may allow for easier manufacturing of features in the shaft 12. Slots 401A and 401B may be drilled to ensure that slots 401A and 401B do not pass completely through shaft 12. In this configuration, flared portions 338A and 338B of proximal element actuators 90A and 90B may remain within shaft 12 to manage slack in proximal element actuators 90A and 90B.

[0167] Before actuator rod 64 (which extends through shaft 12) is inserted and coupled to stud 74 of the fixture, flared portion 338A of proximal element actuator 90A can be inserted into slot 401A through hole 402A and toward hole 402B, and flared portion 338B of proximal element actuator 90B can be inserted into slot 401B through hole 402C and toward hole 402D. As actuator rod 64 extends through shaft 12, movement of flared portions 338A and 338B, and therefore proximal element actuators 90A and 90B, can be restricted. For example, flared portions 338A and 338B can be prevented from advancing through holes 402B and 402D, respectively, and can be prevented from being pulled through actuator rod 64 and through holes 402A and 402C, respectively. Thus, the second end portions of proximal element actuators 90A and 90B can be held in place relative to shaft 12. Once actuator rod 64 is decoupled from stud 74 and then retracted, flared portions 338A and 338B at the distal end portions of proximal element actuators 90A and 90B are no longer restricted from movement and proximal element actuators 90A and 90B are free to move. When the proximal ends are retracted, proximal element actuators 90A and 90B can pass through holes 402A and 402C, respectively, and decouple from proximal elements 16A and 16B, respectively.

[0168] According to the disclosed subject matter, for example, when one hole 402B is formed on one side distal to another hole 402A and one hole 402D is formed on the other side distal to another hole 402C, the slots 401A and 401B may be drilled at an angle toward the distal end of the shaft 12 (see FIG. Figure 65E and Figure 65G). This configuration of slots 401A and 401B may provide easier deployment of proximal element actuators 90A and 90B and may reduce friction.

[0169] The hole 402A may be configured to have a fillet radius 403A (see Figure 65B and Figure 65H ) and hole 402C can be configured with a fillet radius 403B (not shown). Fillet radius 403A and fillet radius 403B can limit sharp edges on holes 402A and 402C and can allow proximal element actuators 90A and 90B to bend gently with fillet radius 403A and 403B. Therefore, fillet radius 403A and 403B can reduce strain and sudden bending of proximal element actuators 90A and 90B. Fillet radius 403A and 403B can also reduce local bending strain and failure caused by pulling proximal element actuators 90A and 90B too hard or cycling them multiple times. Fillet radius 403A and 403B can be at least 0.001 inches. The fillet radius can be at least 20% of the diameter of proximal element wires 90A and 90B. In accordance with the disclosed subject matter, the fillet radius can be at least 10% of the exit hole size. Corner radii 403A and 403B may extend around the entirety of the respective apertures 402A and 402C or may extend along the proximal edges where the proximal element actuators 90A and 90B will engage when pulled proximally. Additionally or alternatively, apertures 402A and 402C may be configured with a plurality of corners including smooth corners 403D and 403E (see FIG. Figure 65I ) chamfer 403C, smooth corners 403D and 403E limit the bending of the proximal element actuators 90A and 90B when pulled proximally.

[0170] Additionally or alternatively, an angle reducing feature 405 can be provided on the outer surface of the shaft 12. For example, the angle reducing feature 405 can include an O-ring or a metal ring and can be provided on the outer diameter of the shaft 12, which can limit the bending of the proximal element actuators 90A and 90B when tightened.

[0171] As disclosed herein and previously discussed, an additional sleeve may be provided. A sleeve (not shown) may be provided at the entrance to the distal angled aperture and may ensure that the catch element remains between the mandrel and the sleeve and may control slack during closure.

[0172] Each proximal element actuator may be coupled to a corresponding proximal element prior to securing the second end of each proximal element actuator to the shaft. Figure 22A 、 Figure 27 and Figure 53Each proximal element actuator may include a first end portion, a second end portion, and an intermediate portion located between the first end portion and the second end portion. Proximal element actuators 90A and 90B may be coupled to proximal elements 16A and 16B, respectively, at the intermediate portions of the proximal element actuators, such that when proximal element actuators 90A and 90B are proximally actuated, proximal element actuators 90A and 90B may move proximal elements 16A and 16B, respectively, relative to arms 53A and 53B, thereby moving first proximal element 16A and second proximal element 16B between a first position and a second position.

[0173] Alternatively, and as with respect to Figures 29 to 34 As depicted, proximal element actuator 90 extends distally through at least one lumen and back proximally through at least one lumen. A variety of catheter configurations can be provided in accordance with the disclosed subject matter. For example, the at least one lumen can include at least a first proximal element actuator lumen and a second proximal element actuator lumen. The at least one lumen can include at least a third proximal element actuator lumen and a fourth proximal element actuator lumen. The delivery device can also include a shaft extending through the at least one lumen, the shaft being releasably coupled to a coupling member of the implantable fixation device.

[0174] Reference Figures 66A to 66D For purposes of illustration and not limitation, each proximal element actuator 90A and 90B can define a ring 95C and 95D, respectively, extending from the distal end portion of the catheter. The rings 95C and 95D can each surround the actuator rod 64. Figure 66A and Figure 66B As discussed above, a portion of shaft 12 extending from nose 318 can have two windows 33 formed therein. Rings 95C and 95D can each pass through a corresponding window 33 formed in shaft 12 such that each ring can surround actuator rod 64. Once fixture 14 is in the desired position, actuator rod 64 can be decoupled from stud 74 and retracted, and subsequent proximal retraction of proximal element actuators 90A and 90B will then decouple proximal element actuators 90A and 90B from proximal elements 16A and 16B. Alternatively, a single window 33 can be provided and each ring 95C and 95D can be disposed through window 33 and around actuator rod 64 in a looped manner.

[0175] Alternatively, the proximal element actuators 90A and 90B may each be separately located at a second end portion (such as described above with respect to FIG. 22A to FIG. 22B as well as Figure 27Detailed description of the exemplary embodiment of the embodiment of the present invention) includes rings 95A and 95B. In this way, each ring 95A and 95B can pass through the corresponding window 33 and be arranged around the actuator rod 64 in a ring-forming manner. This configuration can provide Figure 27 The illustrated embodiment provides similar operational flexibility, but permits removal of proximal element actuators 90A and 90B prior to decoupling shaft 12 from coupling member 19. Alternatively, a single window 33 may be provided and each ring 95A and 95B may be provided through window 33 and around actuator rod 64 in a looped manner.

[0176] As further described herein, each proximal element actuator can be formed from a single or multiple wires that extend from and return to the nose 318 of the shaft 302. Figure 67As shown, for example, proximal element actuators 90A and 90B (of which only proximal element actuator 90A is depicted for clarity) can have second ends that are releasably attached to nose 318 of shaft 302 using one or more proximal element actuator spindles 404. In this configuration, proximal element actuator spindles 404 can extend from the proximal end portion of interventional tool 10 to nose 318 of shaft 302 through lumen 406, such that proximal element actuator spindles 404 can be manipulated by a user outside of the patient's body. For example, the distal end portion of proximal element actuator spindle 404 can include a plunger 408 having a diameter greater than the diameter of lumen 406, such that proximal movement of proximal element actuator spindle 404 can press plunger 408 against a distal surface of nose 318 of shaft 302. As disclosed herein, a single actuator spindle and plunger or two or more actuator spindles and plungers, each coupled to a corresponding proximal element actuator, can be used. Each proximal element actuator 90A and 90B (not shown) can extend from nose 318 and thus be coupled to the corresponding proximal element 16A (and 16B, not shown) at an intermediate portion, for example, via actuator rings 48A (and 48B, not shown) of proximal elements 16A and 16B. The proximal element actuator second end portion is fixed to nose 318 of the shaft. That is, by moving proximal element actuator spindle 404 distally, the distal ends of proximal element actuators 90A and 90B can each be placed between the distal surface of nose 318 of shaft 302 and the proximal surface of the corresponding plunger 408, such that the proximal movement of each proximal element actuator spindle 404 traps or clamps the corresponding proximal element actuator. As disclosed herein, a single actuator spindle and plunger can be used, or two actuator spindles and plungers can be used, each plunger coupled to a corresponding proximal element actuator. This can secure the proximal element actuators so that the proximal elements 16 can be independently moved and released. After the proximal elements are deployed, the corresponding proximal actuators can be separated by distal movement of the proximal element actuator spindle 404 to allow each proximal element actuator 90 to be released and disconnected from the corresponding proximal element.

[0177] Additionally or alternatively, and with reference to Figure 68For purposes of illustration and not limitation, and wherein only proximal element actuator 90A is depicted for clarity, the distal end of proximal element actuator spindle 404 can include a blade 410 fixedly attached to its distal end portion. Proximal element actuator spindle 404 can rotate relative to shaft 302, thereby causing blade 410 to rotate relative to shaft 302. Thus, rotation of proximal element actuator spindle 404 can deploy blade 410 to cut the corresponding proximal element actuator 90. For example, each proximal element actuator 90 can be coupled to nose portion 318 of shaft 302 to form a ring with an intermediate portion coupled to the corresponding proximal element, or directly coupled to the corresponding proximal element. Once the proximal element actuator is cut by the proximal element spindle blade, the proximal element actuator can be withdrawn from the shaft / lumen. A single mandrel 404 and blade 410 may be provided to cut each proximal element actuator individually, or a separate proximal element actuator mandrel 404 and blade 410 may be provided for each proximal element actuator 90A and 90B for independently removing proximal element actuators 90A and 90B.

[0178] As disclosed herein, and as Figures 69A to 69B As shown, for purposes of illustration and not limitation, each proximal element actuator 90A and 90B (wherein only proximal element actuator 90A is depicted for clarity) can include an outer sheath 90G having a window 90W formed therein, an inner mandrel 414 that is axially movable relative to the outer sheath 90G, and a suture extending from the outer sheath and defining a loop 412. The suture can be actuated between a captured position, in which the suture extends into the window 90W of the outer sheath 90G and receives the inner mandrel 414 through the loop 412, and a released position. The inner mandrel 414 can be disposed within the respective outer sheath 90G, wherein the inner mandrel 414 is movable relative to the outer sheath 90B. Each loop 412 can pass through the wire loop 48 or eyelet of the respective proximal element 16A and 16B (wherein only the proximal element 16A is depicted for clarity) and return to the window 90W formed in the outer sheath 90G. Inner shaft 414 can pass through ring 412 within the introducer sheath, thereby securing proximal element actuator 90A to proximal element 16A. Thus, after the proximal element is deployed, proximal retraction of inner shaft 414 can release ring 412 and allow proximal element actuator 90A to be disconnected from proximal element 16A.

[0179] As further described herein, the proximal element actuator 90 can be releasably engaged with a structure activated by a force applied by a user. Figure 70As shown, each proximal element actuator 90A and 90B (of which only proximal element actuator 90A is depicted for clarity) can include a slidable outer sheath 90S and an inner member having a jaw 90P at its distal end portion, for example, wherein jaw 90P includes one or more jaw tines 90PP or the like. Jaws 90P can be formed from a shape-memory material such that one or more jaw tines 90PP are biased outward. In this manner, jaw tines 90PP can be placed through actuator ring 48 of the corresponding proximal element 16A and 16B (of which only proximal element 16A is depicted for clarity). Moving the slidable outer sheath 90S toward the distal end of jaws 90P can lock jaw tines 90PP in an inward position, thereby trapping wire loop 48 of proximal element 16A within jaw tines 90PP. This can be used to secure each proximal element actuator 90 to the corresponding proximal element 16 to allow independent movement and release. After the proximal elements are deployed, the slidable outer sheath 90S can be moved proximally away from the jaws 90P so that the jaws prongs 90PP are no longer locked in the inward position to allow the proximal element actuator 90 to be disconnected from the corresponding proximal element 16.

[0180] Additionally or alternatively, and with reference to Figure 71 For purposes of illustration and not limitation, each proximal element actuator 90A and 90B (wherein only proximal element actuator 90A is depicted for clarity) can be directly bonded to a corresponding proximal element 16A and 16B (wherein only proximal element 16A is depicted for clarity), for example, by adhesive or welding. Each proximal element actuator 90 can include a weakened area, such as a necked portion 90N near the distal end of proximal element actuator 90. When a user applies a sufficient amount of proximal force to a proximal element actuator, such as proximal element actuator 90A, proximal element actuator 90A can break or rupture to disconnect proximal element actuator 90A from proximal element 16A. For example, necked portion 90N can be sized to ensure that the breaking point of proximal element actuator 90A occurs at necked portion 90N. Other suitable configurations include a weakened area that can be a scratched area or other area that is weakened in another manner.

[0181] Although the methods and structures for releasably securing proximal element actuator 90 are illustrated above with one or two proximal element actuators, those structures may be used or modified for use with single or multiple proximal element actuators 90 .

[0182] G. Releasably secure the clamp pusher

[0183] As mentioned above, Figure 39The clamp pusher 83 is highlighted and preferably includes two spring arms 99. Each arm 99 is formed from wire or machined from sheet material or other raw material and has a rectangular cross-section in this embodiment, although other cross-sections are also contemplated. Figure 39 In the embodiment of the present invention, the distal portion 91 of each arm 99 has a notched area 93 forming a pair of fingers that can engage with bosses or other attachment mechanisms on the fixation device. When the fixation device 14 is separated from the delivery catheter shaft 12, the notches can be released from the bosses. Figure 57 and Figure 58 An alternative embodiment of an arm 99 for releasably securing the clip pusher 83 in conjunction with an L-shaped locking configuration is shown.

[0184] Figure 57 and Figure 58 Shown in Figure 6A . Here, the upper shaft 500 is releasably coupled to the lower shaft 506 via a detent mechanism 504, 508. In this embodiment, the upper and lower shafts are generally tubular, but those skilled in the art will appreciate that other configurations are possible. The detent mechanism in this exemplary embodiment includes one or more spring arms 502 integrally formed on the tubular upper shaft 500 and one or more receiving portions 508 sized to receive the spring arms 502. The tubular upper shaft 500 is integrally formed with the one or more spring arms 502, which have a flange-like engagement surface 504 at the distal end of the one or more spring arms 502. The spring arms 502 are preferably biased inwardly, i.e., toward the interior of the shaft 500. The removable tubular lower shaft 506 has one or more receiving portions, in this case apertures 508, which are configured to receive and mate with the engagement surfaces 504 of the spring arms 502 and the engagement surfaces of the arms 99 of the clamp pusher 83. The apertures 508 can extend all the way through the wall of the lower shaft 506 and be sized to snugly mate with both the engagement surfaces 504 of the spring arms 502 and the engagement surfaces 101 at the distal ends 91 of the arms 99. To releasably couple the arms 99 to the tubular lower shaft 506, the engagement surfaces 101 of the arms 99 fit into the corresponding apertures 508. A snugly fitting rod 34 (such as the actuator rod 64) is then inserted through the tubular shafts 500, 506, thereby deflecting the inwardly biased spring arms 502 outwardly so that the engagement surfaces 504 are urged into engagement with the corresponding receiving portions 508 and arms 99, thereby coupling the clamp pusher 83 and the upper shaft 500 to the lower shaft 506.

[0185] Figure 58The lower shaft 506 is shown separated from the upper shaft 500. This is achieved by retracting the rod 34 to a position above the spring arm 502, which allows the engagement surface 504 to be biased inwardly to disengage from the receiving portion 508, thereby allowing the arm 99 of the clamp pusher 83 to separate from the shafts 500, 506.

[0186] While the above is a complete description of a preferred embodiment of the invention, various alternatives, substitutions, additions, modifications and equivalents are possible without departing from the scope of the invention. For example, in many of the embodiments described above, the invention is described in the context of approaching the valve structure from the upstream side, i.e., from the atrial side in the case of the mitral valve. It should be understood that any of the embodiments described above can also be used in other approaches, including from the downstream side of the ventricle or valve and through the heart wall using surgical methods. In addition, the present invention can be used to treat a variety of other tissue structures besides heart valves and will find use in a variety of tissue approximation, attachment, closure, clamping and ligation applications, some intravascular, some endoscopic, and some open surgeries.

[0187] Likewise, although the foregoing invention has been described in some detail by way of illustration and example for purposes of clarity of understanding, it will be apparent that various alternatives, modifications and equivalents may be used and the foregoing description should not be taken as limiting the scope of the invention, which is defined by the appended claims.

Claims

1. A fixation system for engaging tissue of a patient, comprising: An implantable fixation device (14) having a coupling member (19), a distal element (18), and a proximal element (16) movable relative to the distal element (18); and a catheter (86) having a proximal end and a distal end, the catheter (86) further comprising a shaft (12), an actuator rod (64), and a proximal element actuator (90A), each extending from the proximal end of the catheter (86), the shaft (12) being coupled to a coupling member (19) of the fixture (14) and defining a lumen and a first hole (402A) and a second hole (402B) each intersecting the lumen, the actuator rod (64) being movably disposed in the lumen of the shaft (12), and the proximal element actuator (90A) being coupled to the proximal element (16) and having a distal end defining a stop element (337A, 338A), wherein the proximal element actuator (90A) extends through the first hole (402A) of the shaft (12) such that the blocking elements (337A, 338A) are disposed within the second hole (402B) of the shaft (12), and wherein, when the blocking element (337A, 338A) is disposed within the second hole (402B), the actuator rod (64) is movable between a first position and a second position, wherein in the first position, the actuator rod (64) at least partially blocks a path between the first hole (402A) and the second hole (402B) to prevent the blocking element (337A, 338A) from being removed from the first hole (402A) and the second hole (402B), and in the second position, the path is not blocked by the actuator rod (64) and the blocking element (337A, 338A) is able to travel along the path and leave the first hole (402A) and the second hole (402B).

2. The fixing system according to claim 1, wherein: The shaft (12) defines a central longitudinal axis, the first hole (402A) is disposed on a first side of the central longitudinal axis, and the second hole (402B) is disposed on a second side of the central longitudinal axis.

3. The fixing system according to claim 1, wherein: The first aperture (402A) and the second aperture (402B) extend transverse to the central longitudinal axis.

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