US20060122633A1 - Methods and devices for termination - Google Patents

Abstract

Devices and methods used in termination of a tissue tightening procedure are described. Termination includes the cinching of a tether to tighten the tissue, locking the tether to maintain tension, and cutting excess tether. In procedures involving anchors secured to the tissue, the tether is coupled to the anchors and the tissue is tightened via tension applied to the anchors by cinching the tether. In general, the devices and methods can be used in minimally invasive surgical procedures, and can be applied through small incisions or intravascularly. A method for tightening tissue by fixedly coupling a first anchor to a tether and slidably coupling a second anchor to the tether, securing both anchors to the tissue, applying tension to the tether intravascularly, fixedly coupling the tether to the second anchor, and cutting the tether is described. The tissue to be tightened can comprise heart tissue, in particular heart valve annulus tissue. Various devices and methods for locking the tether in place and cutting excess tether are described.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS
• This application is a continuation-in-part of U.S. Ser. No. 11/232,190, filed Sep. 20, 2005, which is a continuation-in-part of U.S. Ser. No. 10/792,681, filed Mar. 2, 2004, which claims the benefit of U.S. Ser. No. 60/459,735, filed on Apr. 1, 2003, U.S. Ser. No. 60/462,502, filed on Apr. 10, 2003, and U.S. Ser. No. 60/524,922, filed on Nov. 24, 2003, and which is a continuation-in-part of U.S. Ser. No. 10/741,130, filed on Dec. 19, 2003, which is a continuation-in-part of U.S. Ser. No. 10/656,797, filed on Sep. 4, 2003, and is a continuation-in-part of U.S. Ser. No. 10/461,043, filed on Jun. 13, 2003, the latter of which claims the benefit of U.S. Ser. No. 60/388,935, filed on Jun. 13, 2002, U.S. Ser. No. 60/429,288, filed on Nov. 25, 2002, U.S. Ser. No. 60/445,890, filed on Feb. 6, 2003, and U.S. Ser. No. 60/462,502, filed on Apr. 10, 2003, the disclosures of which are herein incorporated by reference in their entirety.
FIELD
• The methods and devices described herein relate generally to medical devices and methods, and more specifically to devices and methods for enhancing tissue repair using minimally invasive surgical techniques, especially for use in cardiovascular valve repair.
BACKGROUND
• Advances have been made in techniques and tools for use in minimally invasive surgery that can be performed through small incisions or intravascularly. For example, improvements have been made recently to reduce the invasiveness of cardiac surgery. To avoid open procedures, such as open, stopped-heart surgery, which can lead to high patient morbidity and mortality, devices and methods have been developed for operating through small incision, for operating on a beating heart, and for performing cardiac procedures via intravascular or intravascular access. For many minimally invasive surgery techniques, significant challenges include positioning the treatment device or devices in a desired location for performing the procedure and deploying the treatment into or on the target tissue.
• Heart valve repair can benefit from less invasive surgical techniques. Traditional treatment of heart valve stenosis or regurgitation, such as mitral or tricuspic regurgitation, typically involves an open-heart surgical procedure to replace or repair the valve. Valve repair procedures usually involve annuloplasty, which is a set of techniques designed to restore the valve annulus shape and strengthen the annulus. Conventional annuloplasty surgery generally requires a thoracotomy (a large incision into a patient's thorax), and sometimes a median stemotomy (an incision through a patient's sternum). These open-heart, open-chest procedures routinely involve placing the patient on a heart-lung bypass machine for long periods of time so that the patient's heart and lungs can be stopped during the procedure. In addition, valve repair and replacement is typically technically challenging and requires a substantial incision through a heart wall to access the valve. Many patients such as elderly patients, children, patients with complicating conditions such as comorbid medical conditions or those having undergone other surgical procedures, and patients with heart failure, are not considered candidates for heart valve surgery because of the high risk involved.
• Minimally invasive procedures are typically performed endoscopically through catheters, through small incisions or intravascularly. Instruments such as graspers, dissectors, clip appliers, lasers, cauterization devices and clamps are routinely used endoscopically, with an endoscope used for visualizing the procedure. When a surgeon desires to bring pieces of two tissue together, the surgeon typically threads a suture through the two pieces of tissue, applies tension, and ties off or knots the suture to maintain the tension. However, during endoscopic surgery, the manipulation required when knotting or tying suture material can be difficult because of severely restricted space.
• Previously, there have been attempts to maintain tension in tissue by using staples, clips, clamps, or other fasteners to obviate the need for suturing. However, these methods do not provide adjustable tension such as is available when a surgeon uses suture. U.S. Pat. Nos. 5,520,702 and 5,643,289 describe deformable cylindrical tubes that can be applied over a loop of suture. After a suture is adjusted to a desired tension, the suture is looped, and a deployment gun applies a deformable tube over the suture loop and crimps it so that it clamps down on the suture. After the loop is secured with a crimp, a separate cutting member or tool can be used to cut the excess suture material. U.S. Pat. No. 6,099,553 also describes deformable crimps that can be applied over the ends of sutures to fix them into place. Similar crimping devices that operate to mechanically fasten suture together and cut away excess tether are provided as TI-KNOT® knot replacement systems by LSI Solutions.® However, with crimping schemes, the suture may still slip through crimps and lose tension, especially if the suture has a small diameter, if the suture is made of a material susceptible to slippage, such as metal or TEFLON® fluoropolymer, or if the crimp is insufficiently deformed. U.S. Publication No. 2003/0167071 describes fasteners made from shape memory materials that can be applied to sutures to avoid tying knots in catheter-based procedures. U.S. Pat. Nos. 6,409,743 and 6,423,088 describe fusible collars that can be used in place of knots in securing sutures. These fusible collars require an external source of energy be locally applied to the collar without damaging surrounding tissue for the fusing process.
• Devices and methods for less-invasive repair of cardiac valves have been described. In heart valve repair procedures, it is often desired for a physician to secure one or more treatment devices to valve annulus tissue. Annular tissue tends to be more fibrous than muscular or valve leaflet tissue, and thus can be more suitable tissue for securing treatment devices such as anchors to treat a heart valve. Devices and methods for positioning anchor delivery devices are described in U.S. patent applications Ser. Nos. 60/445,890, 60/459,735, 60/462,502, 60/524,922, 10/461,043, 10/656,797, 10/741,130 and 10/792,681, which were previously incorporated by reference. For example, these references describe devices and methods for exposing, stabilizing and/or performing a procedure on a heart valve annulus.
• Many treatments, including annuloplasty, involve tightening of tissue. For some tissue tightening procedures, anchors coupled to a suture are embedded in tissue, and the suture is then cinched to tighten the tissue via the anchors. Examples of devices and methods for such procedures applied to heart valve repair are provided in U.S. patent applications Ser. Nos. 10/656,797, 10/741,130 and 10/792,681.
• Improved methods and devices for locking a suture to maintain tension in the suture are desired, especially in minimally invasive treatments where surgical access is limited. For treatments involving tissue anchors, improved methods and devices are desired for locking a suture that has been coupled with the anchors such that the suture does not move relative to the last applied anchor. Also desired are improved methods and devices for severing excess suture so that it can be removed.
BRIEF SUMMARY
• Described herein are devices and methods for use in termination procedures during tissue tightening treatments. In general, termination involves any one or all of the steps carried out when finishing a tissue tightening procedure, including: cinching a tether to tighten tissue; locking the cinching tether in place; and cutting off excess tether. Tissue anchors can be secured to the tissue to be tightened and the tether coupled to the anchors, so that cinching of the tether tightens the tissue via the anchors.
• In some variations, a method for tightening tissue is provided. A first anchor is fixedly coupled to a tether, and a second anchor is slidably coupled to the tether. Both anchors are secured to the tissue to be tightened. Tension is applied to the tether intravascularly, the second anchor is fixedly coupled to the tether, and the tether is cut.
• In some variations, the anchors are secured to the tissue intravascularly. In some variations, the tissue includes heart tissue. For example, the tissue can include a heart valve annulus or a mitral valve annulus.
• A force having a component counter to the tensioning force applied to the tether can be applied to the second anchor in some variations. An intravascular device can be contacted with the second anchor to apply the force to the second anchor.
• In some variations, a portion of the tether is loaded into an intravascular device after the anchors are secured to the tissue. The tether can be captured with a loop to load it into the intravascular device. The tether can also be threaded through a feature in a rod, and the rod can be inserted into the intravascular device. The features in the rod can include openings, indents, grooves, slits, or the like.
• In other variations, the tether can be fixedly coupled to the anchor intravascularly. In some variations, the tether is fixedly coupled to the second anchor by clamping the tether to the second anchor. In other variations, the tether can be fixedly coupled to the second anchor by deforming the second anchor. In still other variations, the tether can be fixedly coupled to the second anchor by applying an adhesive to the tether.
• In some variations, the tether is fixedly coupled to the second anchor by providing a locking feature on the tether. The tether can be threaded through a feature on the second anchor, and the locking feature cannot pass through the feature on the second anchor in the direction toward the first anchor. The locking feature can include protrusions that allow the locking feature to slide along the tether in one direction only. The locking feature can include a knot. The locking feature can include a washer through which the tether passes and a knot on the tether, which cannot pass through the washer. In some variations, the locking feature can pass through the feature on the second anchor through which the tether passes in the direction away from the first anchor. The feature on the second anchor can include an eyelet.
• In some variations, the locking feature is clamped to the tether. The tether can be clamped between an expanded deformable mesh and the inner wall of a tube. The tether can be clamped by applying a force to at least partially unkink a kinked tube, passing the tether through the tube, and then releasing the force to re-kink the tube. In some variations, the tether is clamped by applying a force to separate two surfaces of the locking feature, passing the tether between the surfaces, and releasing the force to clamp the tether between the surfaces. The tether can be clamped by applying a force to cause two surfaces of the locking feature to move together to clamp the tether between the two surfaces. In other variations, the tether is passed through an opening in a deformable material, and the deformable material is deformed to cause a dimension in the opening in the deformable material to decrease, thereby clamping the tether. The tether can be clamped by passing the tether through the locking feature and altering the path of the tether through the locking feature to increase the frictional forces on the tether.
• A locking feature (e.g., a clamp, lock, knot, or other tether-securing feature) may be detachable from a delivery device. For example, a locking feature may be releasably (or detachably) connected to a tube, rod, or wire, etc. In one variation, the termination device comprises a locking feature that is detachably connected to a delivery tube. Other features may also be included as part of the termination device, include a tether cutter, a push rod (for detaching and/or activating the locking feature), etc.
• In some variations, the cutting of the tether is performed intravascularly. In other variations, the tether is cut proximal to the second anchor. In still other variations, the tether is cut by shearing the tether between two concentric tubes. One concentric tube can be advanced with respect to the other concentric tube along the axis of the tubes. Alternatively, one concentric tube can be rotated with respect to the other concentric tube about the axis of the tubes.
• In some variations, the tether can be cut by passing the tether through an opening in a tube and rotating a blade in a plane that intersects an axis of the tube. In other variations, the tether can be cut by contacting the tether with a cutting blade. In still other variations, the tether can be cut by passing the tether through a tube, inflating in the tube a balloon to which one or more cutting blades are mounted and rotating the balloon. In other variations, the tether can be cut by shearing the tether between two blades sharing a pivot.
• In some variations, a single intravascular device can deploy the anchors, apply tension to the tether, fixedly couple the tether to the second anchor and cut the tether. In other variations, the same or different intravascular device may be used to perform any step or combination of steps in a method for tightening tissue that includes securing to the tissue a first anchor fixedly coupled to a tether and a second anchor slidably coupled to the tether, applying tension to the tether intravascularly, fixedly coupling the tether to the second anchor and cutting the tether.
• In some variations, a termination device includes a detachable locking feature and a tether cutter. For example, the termination device may comprise a tubular body that couples to a tether with a detachable locking feature at the distal end of the termination device. The termination device may also include a tether cutter. In some variations, the tether cutter is located proximal to the detachable locking feature. In operation, the tether may be coupled to the detachable locking feature (e.g., by threading through a region of the detachable locking feature), and the locking feature may be positioned to secure the tether (e.g., abutting an anchor). The tether may be tensioned appropriately, and the locking feature can be locked and detached from the rest of the termination device. The tether maybe cut either before or after detaching the locking feature. In some variations, the termination device comprises a rod for locking the detachable locking feature and/or for detaching the detachable locking feature.
• Described herein are termination devices for locking an implantable and cinchable tether. The termination devices may include an elongate body and a locking feature releasably attached to the distal end of the elongate body. The locking feature is typically configured to couple to the tether, and has an unsecured state (e.g., an “open” state in some variations), wherein the tether may move with respect to the locking feature, and a secured state (e.g., a “closed state” in some variations), wherein the tether is secured by the locking feature. The termination device may also include a tether cutter. For example, a tether cutter may be located distally to the locking feature. (such as a cutting tube within the elongate body). In some variations, the elongate body is configured as a catheter.
• In some variations, the termination device may also include a force applicator for releasing the locking feature from the rest of the termination device. For example, the force applicator may comprise a push rod extending longitudinally within the elongate body of the termination device. The termination device may also include a releasable attachment region between the locking feature and the elongate body that can be broken or detached to separate the locking feature of the termination device from the rest of the device. The releasable attachment region may be a frangible region, and may be configured to separate the locking feature from the elongate body when a force of greater than a predetermined load (e.g., about 2 lbs) is applied to the locking feature. In some variations, the releasable attachment region comprises a perforated region. The releasable attachment region may also be formed by the connection between two regions made up of different materials. For example, the locking feature may comprise a different material than the elongate body. The locking feature may also be separated from the body of the termination device (e.g., catheter) by a cutter. The cutter may be a sharp slot, hole, or edge attached to an elongate element that slides relative to the joint (e.g., the releasable attachment region), and thus cuts the joint. The cutter may also cut the joint and the tether in a single motion.
• Any appropriate locking feature may be used. In some variations, the locking feature comprises a clamp. In some variations, the locking feature comprises a plug or inner tube that is configured to compress the tether against a wall of the locking feature when the locking feature is in the secured state.
• Also described herein are termination devices including an elongate body, a locking feature releasably attached to the distal end of the elongate body (the locking feature configured to couple to the tether) and a tether cutter coupled to the elongate body, wherein the tether cutter may be activated to cut the tether.
• Methods of securing a cinchable tether are also described. In some variations, these methods may include the steps of coupling the tether to a termination device (wherein the termination device comprises an elongate body and a locking feature releasably attached to the distal end of the elongate body, so that the locking feature can be coupled to the tether), cinching the tether, and securing the tether with the locking feature.
• In some variations, the method of securing a cinchable tether may also include the step of cutting the tether (e.g., using a tether cutter, including a tether cutter that is part of the termination device). The method may also include the step of separating the locking feature from the elongate body. In some variations, the step of separating the locking feature from the elongate body includes applying force to separate the locking feature from the elongate body. The step of applying force may comprise pushing a push rod located at least partly within the elongate body.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a cross-sectional view of a heart with a flexible anchor delivery device being positioned for treatment of a mitral valve annulus, according to some embodiments.
• FIGS.2A-D are cross-sectional views of a portion of a heart, schematically showing positioning of a flexible device for treatment of a mitral valve annulus, according to some embodiments.
• FIG. 3 is a perspective view of a distal portion of an anchor delivery device, according to some embodiments.
• FIG. 4 is a perspective view of a segment of a distal portion of an anchor delivery device, with anchors in an undeployed shape and position.
• FIG. 5 is a different perspective view of the segment of the device shown inFIG. 4.
• FIG. 6 is a perspective view of a segment of a distal portion of an anchor delivery device, with anchors in a deployed shape and position.
• FIGS. 7A-7E are cross-sectional views of an anchor delivery device, illustrating a method for delivering anchors to valve annulus tissue.
• FIGS. 8A and 8B are top views of a plurality of anchors coupled to a self-deforming member or “backbone,” with the backbone shown in an undeployed shape and in a deployed shape.
• FIGS. 9A-9C are various perspective views of a distal portion of a flexible anchor delivery device according to some embodiments.
• FIGS. 10A-10F illustrate a method for applying anchors to a valve annulus and cinching the anchors to tighten the annulus, using an anchor delivery device according to some embodiments.
• FIG. 11 shows a heart in cross-section with a guide catheter device advanced through the aorta into the left ventricle according to some embodiments.
• FIG. 12A-12F illustrate a method for advancing an anchor delivery device to a position for treating a heart valve according to some embodiments.
• FIGS. 13A and 13B are side cross-sectional views of a guide catheter device for facilitating positioning of an anchor delivery device according to some embodiments.
• FIGS. 14A and 14B are illustrative variations of devices and methods for loading tethers into catheters.
• FIGS.15A-H are additional variations of devices and methods for loading tethers into catheters.
• FIGS.16A-E are illustrative examples of termination devices and methods utilizing knots to fix a tether in place.
• FIGS.17 illustrates an example of a termination method and device that utilizes a tether comprising spaced apart protrusions to maintain tension on the tether.
• FIGS.18A-B illustrates additional examples of termination methods and devices that utilize a tether comprising spaced apart protrusions to maintain tension on the tether.
• FIGS.19A-C show variations of termination devices and methods that include threading a tether through a tube that can be straight (to allow the tether to slide) or kinked (to lock the tether into place).
• FIGS.20A-B show variations of termination devices and methods that include threading a tether through a clamp that forces the tether into a tortuous path to fix the tether in place.
• FIGS.21A-C show additional variations of termination devices and methods that include threading a tether through a clamp that forces the tether into a tortuous path to fix the tether in place.
• FIG. 22 shows a variation of a termination device utilizing clips or spring clips to lock a tether.
• FIGS.23A-C illustrate variations of termination devices and methods that utilize an expandable mesh element to fix a tether.
• FIGS.24A-B show examples of termination devices and methods that incorporate threading a tether through protrusions that allow the tether to slide in one direction, but not in the opposite direction.
• FIG. 25 shows another example of a termination device as described herein.
• FIGS.26A-B show examples of termination devices and methods that include threading a tether through a compressible ring, and then compressing the ring such that the inner dimension of the ring is reduced sufficiently to prevent the tether from sliding through the ring.
• FIG. 27 shows another example of a termination device and method that includes threading a tether through a compressible ring, and then compressing the ring such that the inner dimension of the ring is reduced sufficiently to prevent the tether from sliding through the ring.
• FIGS.28A-C show examples of termination devices and methods that include threading a tether through a channel of a clamping device, and inserting an actuator that forces actuator elements into the channel to impede slippage of the tether to lock the tether in place.
• FIGS.29A-F illustrate various examples of termination devices and methods that utilize sharpened tubes to sever excess tether after the tether is locked into place.
• FIGS.30A-B show additional examples of termination devices and methods that utilize sharpened tubes to sever excess tether.
• FIGS.31A-D illustrate variations of tubular termination devices and methods that can be used to cut excess tether after the tether is locked into place.
• FIGS.32A-B show other variations of tubular termination devices and methods for cutting tether.
• FIG. 33 illustrates variations of termination devices and methods that utilize concentric tubes for cutting tether.
• FIGS.34A-D show variations of termination devices and methods that include a rotatable blade attached to the end of a tube.
• FIGS.35A-C provides examples of termination devices and methods that include a hook that pulls excess tether over a cutting surface to sever the tether.
• FIGS.36A-B show examples of termination devices and methods that include the use of angled barbs to cut excess tether.
• FIG. 37 illustrates variations of termination devices and methods in which a cutter attached to an expandable member is used to cut a tether.
• FIGS.38A-D show examples of various termination devices and methods that involve threading a tether between pins and severing the section of tether extended between the pins.
• FIG. 39 shows one variation of a termination device as described herein.
• FIGS. 40A and 40B show different variations of termination devices.
• FIG. 41A shows a termination device and a loading device for loading a tether into a termination device.
• FIG. 41B shows a termination device with a detachable locking feature.
• FIG. 41C shows the locking feature ofFIG. 41B after detaching from the rest of the termination device.
• FIG. 42A and 42B show one variation of a termination device.
DETAILED DESCRIPTION
• The present application discloses methods and devices for tightening tissue. These methods generally involve securing to the tissue a first anchor that is coupled to a tether, securing to the tissue a second anchor that is slidably coupled to the tether, applying tension to the tether, fixing the position of the tether with respect to the second anchor, and cutting the tether. Any or all of these steps can be performed intravascularly. For example, tension can be applied to the tether intravascularly, and the anchors can be secured to the tissue intravascularly. Although for exemplary purposes the following description typically focuses on uses of the disclosed methods and devices in mitral valve and other heart valve repair, such description should not be interpreted to limit the scope of the invention as defined by the claims. Tissue tightened by the disclosed methods and devices may comprise any part of the body including, for example, the heart, bladder, stomach, gastroesophageal junction, vasculature, gall bladder, or the like. The methods and devices disclosed herein may be used, for example, to close or reduce the diameter of any suitable body lumen, valve or structure or to tether portions of tissue which are separate or which have been traumatically severed.
• Heart tissue tightened by the disclosed methods and devices may comprise, for example, an atrial-septal defect or a heart valve annulus such as, for example, a mitral valve annulus. In many cases, methods disclosed herein may be performed on a beating heart. Access to the beating heart may be accomplished by any available technique, including intravascular, transthoracic, and the like. In addition to beating heart access, the methods disclosed herein may be used for intravascular stopped heart access as well as stopped heart open chest procedures.
• The first portion of this application will describe exemplary methods and devices for securing tethered anchors to tissue in the context of a heart valve repair procedure. The anchors can be secured to tissue intravascularly. Subsequent portions of the application will describe exemplary methods and devices for applying tension to the tether to tighten the tissue, for locking the tether to an anchor or otherwise fixing the position of the tether with respect to an anchor to maintain the tension, and for cutting the tether. The methods and devices described for performing these steps are meant to be exemplary and should not be interpreted as limiting the scope of the claims.
• Referring now toFIG. 1, a heart H is shown in cross section, with an elongateanchor delivery device100 introduced within the heart H. Generally,delivery device100 comprises an elongate body with adistal portion102 configured to deliver anchors to, for example, a heart valve annulus. (InFIGS. 1, 2A and2B,distal portion102 is shown diagrammatically without anchors or an anchor-delivery mechanism to enhance clarity of the figures.) In some embodiments, the elongate body comprises a rigid shaft, while in other embodiments it comprises a flexible catheter, so thatdistal portion102 may be positioned in the heart H and, for example, under one or more valve leaflets to engage a valve annulus via a intravascular approach. Intravascular access may be gained, for example, through the internal jugular vein (not shown) to the superior vena cava SVC to the right atrium RA, across the interatrial septum to the left atrium LA, and then under one or more mitral valve leaflets MVL to a position within the left ventricle (LV) under the valve annulus (not shown). Alternatively, access to the heart may be achieved via the femoral vein and the inferior vena cava. In other embodiments, access may be gained via the coronary sinus (not shown) and through the atrial wall into the left atrium. In still other embodiments, access may be achieved via a femoral artery and the aorta, into the left ventricle, and under the mitral valve. Any other suitable access route may also be used.
• In other embodiments, access to the heart H may be transthoracic, withdelivery device100 being introduced into the heart via an incision or port in the heart wall. Even open heart surgical procedures may benefit from the disclosed methods and devices. Furthermore, some embodiments may be used to enhance procedures on the tricuspid valve annulus, adjacent the tricuspid valve leaflets TVL, or any other cardiac or vascular valve. Therefore, although the following description typically focuses on minimally invasive or less invasive mitral valve repair for treating mitral regurgitation, the disclosed methods and devices are in no way limited to that use.
• With reference now toFIGS. 2A and 2B, a method for positioningdelivery device100 for treating a mitral valve annulus VA is depicted diagrammatically in a cross-sectional view. First, as inFIG. 2A,distal portion102 is positioned in a desired location under a mitral valve leaflet L and adjacent a ventricular wall VW. (Again,distal portion102 is shown without anchors or anchor-delivery mechanism for demonstrative purposes.) The valve annulus VA generally comprises an area of heart wall tissue at the junction of the ventricular wall VW and the atrial wall AW that is relatively fibrous and, thus, significantly stronger than leaflet tissue and other heart wall tissue.
• Distal portion102 may be advanced into position under the valve annulus by any suitable technique, some of which are described below in further detail. Generally,distal portion102 may be used to deliver and secure anchors to the valve annulus, to stabilize and/or expose the annulus, or both. In some embodiments using a delivery device having a flexible elongate body as shown inFIG. 1, a flexibledistal portion102 may be passed from the right atrium RA through the interatrial septum in the area of the foramen ovale (not shown—behind the aorta A), into the left atrium LA and thus the left ventricle LV. Alternatively, flexibledistal portion102 may be advanced through the aorta A and into the left ventricle LV, for example using access through a femoral artery. Oftentimes,distal portion102 will then naturally travel, upon further advancement, under the posterior valve leaflet L into a space defined above asubvalvular space104 roughly defined for the purposes of this application as a space bordered by the inner surface of the left ventricular wall VW, the inferior surface of mitral valve leaflets L, and cordae tendineae CT connected to the ventricular wall VW and the leaflet L. It has been found that a flexible anchor delivery catheter, such as the delivery devices disclosed herein, when passed under the mitral valve via an intravascular approach, often enterssubvalvular space104 relatively easily and may be advanced alongspace104 either partially or completely around the circumference of the valve. Once inspace104,distal portion102 may be conveniently positioned at the intersection of the valve leaflet(s) and the ventricular wall VW, which intersection is immediately adjacent or very near to the valve annulus VA, as shown inFIG. 2A. These are but examples of possible access routes of an anchor delivery device to a valve annulus, and any other access routes may be used.
• In some embodiments,distal portion102 includes a shape-changing portion which enablesdistal portion102 to conform to the shape of the valve annulus VA. The catheter may be introduced through the vasculature with the shape-changing distal portion in a generally straight, flexible configuration. Once it is in place beneath the leaflet at the intersection between the leaflet and the interior ventricular wall, the shape ofdistal portion102 is changed to conform to the annulus and usually the shape is “locked” to provide sufficient stiffness or rigidity to permit the application of force fromdistal portion102 to the annulus. Shaping and optionally lockingdistal portion102 may be accomplished in any of a number of ways. For example, in some embodiments, a shape-changing portion may be sectioned, notched, slotted or segmented and one or more tensioning members such as tensioning cords, wires or other tensioning devices coupled with the shape-changing portion may be used to shape and rigidifydistal portion102. A segmented distal portion, for example, may include multiple segments coupled with two tensioning members, each providing a different direction of articulation to the distal portion. A first bend may be created by tensioning a first member to give the distal portion a C-shape or similar shape to conform to the valve annulus, while a second bend may be created by tensioning a second member to articulate the C-shaped member upwards against the annulus. In other embodiments, a shaped expandable member, such as a balloon, may be coupled withdistal portion102 to provide for shape changing/deforming. In various embodiments, any configuration and combination may be used to give distal portion102 a desired shape.
• For transthoracic methods and other embodiments,distal portion102 may be pre-shaped, and the method may simply involve introducingdistal portion102 under the valve leaflets. The pre-shapeddistal portion102 may be rigid or formed from any suitable super-elastic or shape memory material, such as nickel titanium alloys, spring stainless steel, or the like.
• In addition to delivering and securing anchors to the valve annulus VA, delivery device100 (and specifically distal portion102) may be used to stabilize and/or expose the valve annulus VA. Such stabilization and exposure procedures are described fully in U.S. patent application Ser. No. 10/656,797, which was previously incorporated by reference. For example, oncedistal portion102 is positioned under the annulus, force may be applied todistal portion102 to stabilize the valve annulus VA, as shown inFIG. 2B. Such force may be directed in any suitable direction to expose, position and/or stabilize the annulus. For example, upward and lateral force is shown inFIG. 2B by the solid-headed arrow drawn from the center ofdistal portion102. In other cases, only upward, only lateral, or any other suitable force(s) may be applied. With application of force todistal portion102, the valve annulus VA is caused to rise or project outwardly, thus exposing the annulus for easier viewing and access. The applied force may also stabilize the valve annulus VA, also facilitating surgical procedures and visualization.
• Some embodiments may include a stabilization component as well as an anchor delivery component. For example, some embodiments may include two flexible members, one for contacting the atrial side of a valve annulus and the other for contacting the ventricular side. In some embodiments, such flexible members may be used to “clamp” the annulus between them. One of such members may be an anchor delivery member and the other may be a stabilization member, for example. Any combination and configuration of stabilization and/or anchor delivery members is contemplated.
• Referring now toFIGS. 2C and 2D, ananchor delivery device108 is shown delivering and securing ananchor110 to a valve annulus VA. These are again representational figures and are not drawn to scale.Anchor110 is shown first housed within delivery device108 (FIG. 2C) and then delivered to the annulus VA (FIG. 2D). As is shown, in some embodiments anchors110 may have a relatively straight configuration when housed indelivery device108, for example, anchors110 may have two sharpened tips (although they need not be) and a loop in between the tips. Upon deployment fromdelivery device108, the tips ofanchor110 may curve in opposite directions to form two semi-circles, circles, ovals, overlapping helices or the like. This is but one example of a type of self-securing anchor that may be delivered to a valve annulus. Typically, multiple coupledanchors110 are delivered, and theanchors110 are drawn together to tighten the valve annulus. Methods for anchor delivery and for drawing anchors together are described further below.
• Althoughdelivery device108 is shown having a circular cross-sectional shape inFIGS. 2C and 2D, it may alternatively have any other suitable shape. In some embodiments, for example, it may be advantageous to provide a delivery device having an ovoid or elliptical cross-sectional shape. Such a shape may help ensure that the device is aligned, when positioned in a corner formed by a ventricular wall and a valve leaflet, such that one or more openings in the delivery device is oriented to deliver the anchors into valve annulus tissue. To further enhance contacting of the valve annulus and/or orientation of the delivery device, some embodiments may further include an expandable member, coupled with the delivery device, which expands to urge or press or wedge the delivery device into the corner formed by the ventricle wall and the leaflet to contact the valve annulus. Such enhancements are described further below.
• With reference now toFIG. 3, some embodiments of a portion of ananchor delivery device200 suitably include anelongate shaft204 having adistal portion202 configured to deliver a plurality ofanchors210, coupled with atether212, to tissue of a valve annulus.Tethered anchors210 are housed within ahousing206 ofdistal portion202, along with one or moreanchor retaining mandrels214 and anexpandable member208. Many variations may be made to one or more of these features, and various parts may be added or eliminated. Some of these variations are described further below, but no specific embodiment(s) should be construed to limit the scope of the invention as defined by the appended claims.
• Housing206 may be flexible or rigid in various embodiments. In some embodiments, for example,flexible housing206 may be comprised of multiple segments configured such thathousing206 is deformable by tensioning a tensioning member coupled to the segments. In some embodiments,housing206 is formed from an elastic material having a geometry selected to engage and optionally shape or constrict the valve annulus. For example, the rings may be formed from super-elastic material, shape memory alloy such as nickel titanium alloys, spring stainless steel, or the like. In other instances,housing206 could be formed from an inflatable or other structure that can be selectively rigidified in situ, such as a gooseneck or lockable element shaft, any of the rigidifying structures described above, or any other rigidifying structure.
• “Anchors,” for the purposes of this application, is defined to mean any fasteners. Thus, anchors (e.g., anchors210) may comprise C-shaped or semicircular hooks, curved hooks of other shapes, straight hooks, barbed hooks, clips of any kind, T-tags, or any other suitable fastener(s). In some embodiments, as described above, anchors may comprise two tips that curve in opposite directions upon deployment, forming two intersecting semi-circles, circles, ovals, helices or the like. In some embodiments, anchors (e.g., anchors210) are self-deforming. By “self-deforming” it is meant that anchors change from a first undeployed shape to a second deployed shape upon release of anchors from restraint in a housing (e.g., release ofanchors210 from housing206). Such self-deforming anchors may change shape as they are released from a housing and enter valve annulus tissue to secure themselves to the tissue. Thus, for the example shown inFIG. 3, a crimping device or other similar mechanism is not required ondistal end202 to apply force toanchors210 to attach them to annular tissue. Self-deforming anchors may be made of any suitable material, such as a super-elastic or shape-memory material like a nickel titanium alloy or spring stainless steel. In other embodiments, anchors may be made of a non-shape-memory material and may be loaded into a housing in such a way that they change shape upon release. Alternatively, anchors that are not self-deforming may be used, and such anchors may be secured to tissue via crimping, firing or the like. Even self-securing anchors may be crimped in some embodiments to provide enhanced attachment to tissue. Delivery of anchors may be accomplished by any suitable device and technique, such as by simply releasing the anchors by hydraulic balloon delivery as discussed further below. Any number, size and shape of anchors may be included in a housing.
• In some embodiments, anchors (e.g., anchors210) are generally C-shaped or semicircular in their undeployed form, with the ends of the “C” being sharpened to penetrate tissue or being blunt, but configured to penetrate tissue when expanded with force. Approximately midway along the C-shaped anchor, an eyelet may be formed for allowing slidable passage of a tether (e.g., tether212). To maintainanchors210 in their C-shaped, undeployed state, anchors210 may be retained withinhousing206 by twomandrels214, onemandrel214 retaining each of the two arms of the C-shape of eachanchor210.Mandrels214 may be retractable withinelongate catheter body204 to releaseanchors210 and allow them to change from their undeployed C-shape to a deployed shape. The deployed shape, for example, may approximate a complete circle or a circle with overlapping ends, the latter appearing similar to a key ring. Such anchors are described further below, but generally may be advantageous in their ability to secure themselves to annular tissue by changing from their undeployed to their deployed shape. In some embodiments, anchors (e.g., anchors210) are also configured to lie flush with a tissue surface after being deployed. By “flush” it is meant that no significant amount of an anchor protrudes from the surface, although some small portion may protrude.
• Tethers (e.g., tether212) may be one long piece of material or two or more pieces and may comprise any suitable material, such as suture, suture-like material, a DACRON® polyester strip or the like. Retainingmandrels214 may also have any suitable configuration and be made of any suitable material, such as stainless steel, titanium, nickel titanium alloys, or the like. Various embodiments may have one mandrel, two mandrels, or more than two mandrels.
• In some embodiments, anchors210 may be released frommandrels214 to contact and secure themselves to annular tissue without any further force applied bydelivery device200. Some embodiments, however, may also include one or moreexpandable members208, which may be expanded to help driveanchors210 into tissue. Expandable member(s)208 may have any suitable size and configuration and may be made of any suitable material(s). Hydraulic systems such as expandable members are known in the art, and any known or as yet undiscovered expandable member may be included inhousing206 as part of the present invention.
• Referring now toFIGS. 4 and 5, a segment of adistal portion302 of an anchor delivery device suitably includes ahousing306, multiple tensioningmembers320 for applying tension tohousing306 to change its shape, twoanchor retaining mandrels314 slidably disposed inhousing306,multiple anchors310 slidably coupled with atether312, and anexpandable member308 disposed betweenanchors310 andhousing306. As can be seen inFIGS. 4 and 5,housing306 may include multiple segments to allow the overall shape ofhousing306 to be changed by applying tension to tensioningmembers320. As also is evident from the drawings, “C-shaped” anchors310 may actually have an almost straight configuration when retained bymandrels314 inhousing306. Thus, for the purposes of this application, “C-shaped” or “semicircular” refers to a very broad range of shapes including a portion of a circle, a slightly curved line, a slightly curved line with an eyelet at one point along the line, and the like.
• With reference now toFIG. 6, the same segment ofdistal portion302 is shown, butmandrels314 have been withdrawn from twomandrel apertures322, to releaseanchors310 fromhousing306. Additionally,expandable member308 has been expanded to drive anchors out ofhousing306.Anchors310, having been released frommandrels314, have begun to change from their undeployed, retained shape to their deployed, released shape.
• Referring now toFIGS. 7A-7E, a cross-section of adistal portion402 of an anchor delivery device is shown in various stages of delivering an anchor to tissue of a valve annulus VA. InFIG. 7A,distal portion402 is positioned against the valve annulus, ananchor410 is retained by twomandrels414, atether412 is slidably disposed through an eyelet onanchor410, and anexpandable member408 is coupled withhousing406 in a position to driveanchor410 out ofhousing406. When retained bymandrels414,anchor410 is in its undeployed shape. As discussed above,mandrels414 may be slidably retracted, as designated by the solid-tipped arrows inFIG. 7A, to releaseanchor410. In various embodiments, anchors410 may be released one at a time, such as by retractingmandrels414 slowly, may be released in groups, or may all be released simultaneously, such as by rapid retraction ofmandrels414.
• InFIG. 7B,anchor410 has begun to change from its undeployed shape to its deployed shape (as demonstrated by the hollow-tipped arrows) and has also begun to penetrate the annular tissue VA.Empty mandrel apertures422 demonstrate thatmandrels414 have been retracted at least far enough to releaseanchor410. InFIG. 7B,expandable member408 has been expanded to driveanchor410 partially out ofhousing406 and further into the valve annulus VA.Anchor410 also continues to move from its undeployed towards its deployed shape, as shown by the hollow-tipped arrows. InFIG. 7D,anchor410 has reached its deployed shape, which is roughly a completed circle with overlapping ends or a “key ring” shape. InFIG. 7E,delivery device402 has been removed, leaving a tethered anchor secured in place in the valve annulus. Of course, there will typically be a plurality of tethered anchors secured to the annular tissue. Tether412 may then be cinched to apply force toanchors410 and cinch and tighten the valve annulus. The tether may be cinched using any suitable device or method. For example, during cinching a force can be applied to the most proximal anchor having a vector component counter to the force applied to the tether to cinch the tether. An intravascular device, such as a pusher, may be used to apply this force to the most proximal anchor.
• With reference now toFIGS. 8A and 8B, a diagrammatic representation of another embodiment of coupled anchors is shown. Here, anchors510 are coupled to a self-deforming or deformable coupling member orbackbone505.Backbone505 may be fabricated, for example, from nickel titanium alloys, spring stainless steel, or the like, and may have any suitable size or configuration. In one embodiment, as inFIG. 8A,backbone505 is shaped as a generally straight line when held in an undeployed state, such as when restrained within a housing of an anchor deliver device. When released from the delivery device,backbone505 may change to a deployed shape having multiple bends, as shown inFIG. 8B. By bending,backbone505 shortens the longitudinal distance between anchors, as demonstrated by the solid-tipped arrows inFIG. 8B. This shortening process may act to cinch a valve annulus into which anchors510 have been secured. Thus, anchors510 coupled tobackbone505 may be used to cinch a valve annulus without using a tether or applying tethering force. Alternatively, a tether may also be coupled withanchors510 to further cinch the annulus. In such an embodiment,backbone505 will be at least partially conformable or cinchable, such that when force is applied toanchors510 andbackbone505 via a tether,backbone505 bends further to allow further cinching of the annulus.
• Referring now toFIGS. 9A-9C, in some embodiments a flexible distal portion of ananchor delivery device520 suitably includes ahousing522 coupled with anexpandable member524.Housing522 may be configured to house multiple coupledanchors526 and ananchor contacting member530 coupled with apull cord532.Housing522 may also includemultiple apertures528 for allowing egress ofanchors526. For clarity,delivery device520 is shown without a tether inFIGS. 9A and 9C, butFIG. 9B shows that atether534 may extend through an eyelet, loop or other portion of eachanchor526, and may exit eachaperture528 to allow for release of the plurality ofanchors526. Various features of these embodiments are described further below.
• In the embodiments shown inFIGS. 9A-9C, anchors526 are relatively straight and lie relatively in parallel with the long axis ofdelivery device522.Anchor contacting member530, which may comprise any suitable device, such as a ball, plate, hook, knot, plunger, piston, or the like, generally has an outer diameter that is nearly equal to or slightly less than the inner diameter ofhousing522. Contactingmember530 is disposed within the housing, distal to adistal-most anchor526, and is retracted relative tohousing522 by pullingpull cord532. When retracted,anchor contacting member530 contacts and applies force to adistal-most anchor526 to cause thatanchor526 to exithousing522 via one of theapertures528. Contactingmember530 is then pulled farther proximally to contact and apply force to thenext anchor526 to deploy thatanchor526, and so on.
• Retracting contactingmember530 to pushanchors526 out ofapertures528 may help causeanchors526 to avidly secure themselves to adjacent tissue. Usinganchors526 that are relatively straight/flat when undeployed allowsanchors526 with relatively large deployed sizes to be disposed in and delivered from a relativelysmall housing522. In some embodiments, for example, anchors526 that deploy into a shape approximating two intersecting semi-circles, circles, ovals, helices, or the like, and that have a radius of one of the semi-circles of about 3 mm may be disposed within ahousing522 having a diameter of about 5 French (1.67 mm), or about 4 French (1.35 mm), or even smaller.Such anchors526 may measure about 6 mm or more in their widest dimension. These are only examples, however, and other larger orsmaller anchors526 may be disposed within a larger orsmaller housing522. Furthermore, any convenient number ofanchors526 may be disposed withinhousing522. In some embodiments, for example,housing522 may hold about 1-20anchors526, or about 3-10anchors526. Other embodiments may holdmore anchors526.
• Anchor contacting member530 andpull cord532 may have any suitable configuration and may be manufactured from any material or combination of materials. In alternative embodiments, contactingmember530 may be pushed by a pusher member to contact and deployanchors526. Alternatively, any of the anchor deployment devices and methods previously described may be used.
• Tether534, as shown inFIG. 9B, may comprise any of thetethers534 or tether-like devices already described above, or any other suitable device. Tether534 is generally fixedly coupled to adistal-most anchor526 at anattachment point536. By “fixedly coupled,” here it is meant thattether534 is coupled todistal-most anchor526 in a manner that preventstether534 from sliding through or pastdistal-most anchor526 in the direction of more proximal neighboring anchors526. This may be achieved, for example, via a knot, weld, adhesive, or by any other suitable mechanism that fixedly couplestether534 todistal-most anchor526. Fixedly coupling includes, for example, via a knot, protuberance, or other feature ontether534 that cannot pass through an eyelet, loop, or other similar feature indistal-most anchor526 through whichtether534 passes. Tether534 then extends through an eyelet, loop or other similar feature on each of theanchors526 so as to be slidably coupled with theanchors526. In the embodiments shown,tether534 exits eachaperture528, then enters the next-most-proximal aperture, passes slidably through a loop on ananchor526, and exits thesame aperture528. By entering and exiting eachaperture528,tether534 allows the plurality ofanchors526 to be deployed into tissue and cinched. Other configurations ofhousing522, anchors526 andtether534 may alternatively be used. For example,housing522 may include a longitudinal slit through whichtether534 may pass, thus allowingtether534 to reside wholly within housing before deployment.
• Expandable member524 is an optional feature ofanchor delivery device520, and thus may be included in some embodiments and not in others. In other words, a distal portion ofanchor delivery device520 may include housing, contents of housing, and other features either with or without an attached expandable member.Expandable member524 may comprise any suitable expandable member currently known or discovered in the future, and any method and substance(s) may be used to expandexpandable member524. Typically,expandable member524 will be coupled with a surface ofhousing522, will have a larger expanded radius thanhousing522, and will be configured such that when it is expanded ashousing522 nears or contacts the valve annulus,expandable member524 will push or presshousing522 into enhanced contact with the annulus. For example,expandable member524 may be configured to expand within a space near the corner formed by a left ventricular wall and a mitral valve leaflet.
• Generally,anchor delivery device520 may be advanced into any suitable location for treating any valve by any suitable advancing or device placement method. Many catheter-based, minimally invasive devices and methods for performing intravascular procedures, for example, are well known, and any such devices and methods, as well as any other devices or method described in this application or later developed, may be used to advance orposition delivery device520 in a desired location.
• Another implementation of a method for securing a plurality oftethered anchors526 to a mitral valve annulus VA in a heart is now described with reference toFIGS. 10A-10F,11, and12A-12F. Referring first toFIG. 11 (a cross-sectional depiction of a heart H), in one embodiment afirst guide catheter550 is advanced in retrograde fashion through the aorta A, typically via access from a femoral artery.Guide catheter550 is passed into the left ventricle LV of the heart and thus into thesubannular space552.Subannular space552 is generally defined by the left ventrical wall, the mitral valve leaflets MVL, and cordae tendineae of the left ventricle and travels along most or all of the circumference of the valve annulus.Guide catheter550 is generally a flexible elongate catheter which may have one or more curves or bends toward its distal end to facilitate placement of the distal end ofcatheter550 insubannular space552. The distal end ofguide catheter550 may be configured to be positioned at an opening into or withinsubannular space552 such that subsequent catheter devices may be passed throughguide catheter550 intospace552.
• InFIGS. 12A-12F the mitral valve MV, including mitral valve leaflets MVL, is represented diagrammatically from an inferior perspective looking up. InFIG. 12A, guidecatheter550 is show extending up to or intosubannular space552, as inFIG. 11. As shown inFIG. 12B, asecond guide catheter554 may be advanced throughfirst guide catheter550 to pass through/along a portion or all ofsubannular space552. In one embodiment thissecond guide catheter554 is steerable (as described below with respect toFIGS. 13A and 13B, for example), to help conformsecond guide catheter554 tosubannular space552.
• Next, as shown inFIG. 12C, aguide sheath556 may be passed oversecond guide catheter554 to extend alongsubannular space552.Sheath556 is generally a flexible, tubular member that can be passed oversecond guide catheter554 and withinfirst guide catheter550. To enhance passage and exchange, any of these and other described catheter members, sheath members, or the like may be manufactured from and/or coated with one or more friction resistant materials. Oncesheath556 is in place,second guide catheter554 may be withdrawn, as shown inFIG. 12D. As shown inFIG. 12E, an anchor delivery device520 (described above) may then be advanced throughsheath556 to a desired position withinsubannular space552.Sheath556 may then be withdrawn as inFIG. 12F, leavinganchor delivery device520.
• These are only exemplary methods for advancing an anchor delivery device to a position for treating a valve annulus, and any other suitable method or combination of devices may be used to position an anchor delivery device. In various alternative embodiments, one or more steps may be added, deleted or modified while achieving a similar result. In some embodiments, a similar method may be used to treat the mitral valve from a superior/right atrial position or to treat another heart valve. Additionally, other devices or modifications of the systems just described may be used in other embodiments.
• Referring now toFIG. 10A,anchor delivery device520 is contacted with the valve annulus VA such thatopenings528 are oriented to deployanchors526 into the annulus. Such orientation may be achieved by any suitable technique. In some embodiments, for example, ahousing522 having an elliptical cross-sectional shape may be used to orientopenings528. As described above, in some implementations contact betweenhousing522 and the valve annulus VA may be enhanced by expanding anexpandable member524 to wedgehousing522 within the corner formed by the left ventricular wall and the valve leaflets.
• As shown inFIG. 10B, whendelivery device520 is positioned in a desired location for deployinganchors526,anchor contacting member530 is retracted to contact and apply force to a most-distal anchor526 to begin deployinganchor526 throughaperture528 and into tissue of the valve annulus VA.FIG. 10C showsanchor526 further deployed out ofaperture528 and into valve annulus VA.FIG. 10D shows the valve annulus VA transparently so that further deployment ofanchors526 can be seen. As shown, in some embodiments anchors526 include two sharpened tips (although they need not be) that move in opposite directions upon release fromhousing522 and upon contacting the valve annulus VA. Between the two sharpened tips, ananchor526 may be looped or have any other suitable eyelet or other device for allowing slidable coupling with atether534.
• Referring now toFIG. 10E, anchors526 are seen in their fully deployed or nearly fully deployed shape, with each tip (or “arm”) of eachanchor526 having curved to form a circle or semi-circle. Of course, in various embodiments anchors526 may have any other suitable deployed and undeployed shapes, as described more fully above.FIG. 10F showsanchors526 deployed into and secured to the valve annulus VA and coupled withtether534, with thedistal-most anchor526 fixedly coupled to tether534 atattachment point536 andother anchors526 slidably coupled totether534.
• Although the implementation just described employedanchor delivery device520, any other suitable anchor delivery devices known, described herein, or later developed may also be used to secure a plurality of tethered anchors to a mitral valve annulus or other tissue. In some implementations, after the anchors have been secured to the tissue the anchor delivery device may be withdrawn. In other implementations, as described below, the anchor delivery device may be further employed in subsequent steps of a tissue tightening method. In some embodiments, the anchor delivery device is withdrawn throughfirst guide catheter550, andfirst guide catheter550 is then withdrawn. In alternative embodiments,first guide catheter550 may be withdrawn before the anchor delivery device is withdrawn.
• In various embodiments, alternative methods may be used to urge an anchor delivery device into contact with the valve annulus. For example, in some embodiments a magnet may be coupled with the anchor delivery device, and another anchor may be disposed within the coronary sinus, in proximity to the first magnet. The two magnets may attract one another, thus pulling the anchor delivery device into greater contact with the annulus. Various embodiments may also include visualizing the annulus using a visualization member coupled with or separate from the anchor delivery device. In some embodiments, the tether is a strip of detachable, biocompatible material, such as DACRON® polyester, that is coupled with the anchor delivery device. The anchors are driven through the strip, which detaches to affix to the valve annulus via the anchors. In other embodiments, the tether is a detachable, biocompatible, distal portion of the guide sheath through which the anchors are driven, and that portion of the guide sheath remains attached to the annulus via the anchors.
• Referring again toFIG. 10F, after the plurality oftethered anchors526 has been secured to the valve annulus, tension may be applied totether534 to cinchtether534 and thereby tighten the annulus, thus reducing valve regurgitation. In some embodiments, valve function may be monitored by any suitable method, such as echocardiogram and/or fluoroscopy, andtether534 may be cinched, loosened, and adjusted to achieve a desired amount of tightening as evident via the employed visualization technique(s) or monitored function(s). When a desired amount of tightening is achieved,tether534 is then fixedly coupled to a most-proximal anchor526 (or to two or more most-proximal anchors526), using any suitable technique. By “fixedly coupled,” here it is meant thattether534 is coupled to most-proximal anchor or anchors526 in a manner that preventstether534 from sliding through or past most proximal anchor or anchors526 in the direction of moredistal anchors526. Suitable techniques for fixedly couplingtether534 to most proximal anchor or anchors536 include but are not limited to use of adhesives, tying, knotting, crimping the anchor, deforming the anchor, clamping the tether to the anchor, and providing a locking feature on the tether that, for example, cannot pass through an eyelet, loop, or other similar feature in the most proximal anchor or anchors. Some of these techniques are discussed in additional detail below.
• Still referring toFIG. 10F, aftertether534 has been fixedly coupled to most proximal anchor or anchors526,tether534 is cut proximal to the most-proximal anchor526, thus leaving the cinched,tethered anchors526 in place along the valve annulus VA. Tether534 may be cut via any technique such as, for example, with a cutting member coupled withhousing522. Techniques and devices for cuttingtether534 are discussed in additional detail below.
• In some embodiments it may be advantageous to deploy a first set ofanchors526 along a first portion of a valve annulus VA, cinch the first set of anchors to tighten that portion of the annulus, move thedelivery device520 to another portion of the annulus (typically the opposite side), and deploy and cinch a second set ofanchors526 along a second portion of the annulus. Such a method may be more convenient in some cases than extendingdelivery device520 around all or most of the circumference of the annulus, and may allow a shorter, moremaneuverable housing522 to be used.
• In some embodiments the steps of securing the anchors to the tissue, applying tension to the tether, fixedly coupling the tether to the most proximal anchor or anchors and cutting the tether are performed by the same device. Any or all of these steps may be performed intravascularly. In other embodiments different devices may be used to perform each step or combinations of these steps. For example, in some embodiments, a first device deploys and secures the anchors to tissue and one or more other devices performs the termination steps of applying tension to the tether, fixedly coupling the tether to one or more of the most proximal anchors, and cutting the tether. Devices that perform one or more of these termination steps are described herein as termination devices.
• If an initial step is performed by a first device and a subsequent step is to be performed by a second device such as a termination device, it may be necessary to load the tether into the second device. Both devices can be intravascular devices. Generally such loading will occur after the tethered anchors have been secured to tissue. The tether may be loaded into the second device prior to introducing the second device into the body, e.g., into the vasculature. Alternatively, the tether may be loaded into the second device in situ (e.g., intravascularly).
• Referring now toFIGS. 14A and 14B, in some embodiments,tether534 is loaded intotermination device600 using a lasso604 (e.g., a threading device) which comprises aloop606 at one end. One end of tether534 (not shown) is coupled to a plurality of anchors that have been secured to tissue by, for example, the methods and/or devices described herein. The other end oftether534 is threaded throughloop606 oflasso604.Lasso604 may then be pulled along the axis of termination device600 (FIG. 14A) or, in alternative implementations, through aside hole608 in termination device600 (FIG. 14B) to loadtether534 intotermination device600.Termination device600 may then perform one or more termination steps.Lasso604 may be made from, for example, conventional materials such as wire, suture, cable, string, or a monofilament. The lasso may comprise a loop (as show inFIGS. 14A and 14B), a hook, a coil, a tube, an elongate element with hole, or any other structure or material that can “grab” the tether.
• In other embodiments (e.g.,FIGS. 15A-15H) the tether is loaded into a termination device by threading the tether through one or more features in a rod and then inserting the rod into the termination device. These rods may be of a length that facilitates easy handling, if applicable, and sized to interface with the termination device. Preferably, the rods are 60-150 cm. The rods may be composed of any material which will perform the function of handling the tether, including metal and plastic (e.g., nylon, PEBAX, PEEK, Fluoro polymer like PTFE, PET, or polyethylene, polypropylene, or metal braided polymer). The features in the rod may be, for example, holes, openings, indents, grooves, and slits. The rod may remain in the termination device or be subsequently removed. In some implementations a knot may be tied at the proximal end of the tether to prevent the tether from slipping out of the rod. In some implementations the rod has a passage from one end of the rod to a first opening in a side of the rod and another passage from the other end of the rod to a second opening in a side of the rod. The tether may be threaded through these passages. InFIG. 15A, for example,rod610 comprises atube612 with side holes614. Tether534 is threaded through one end of the tube, through the two side holes, and through the other end of the tube.Rod610 is then inserted into termination device600 (FIG. 15B).
• In other implementations, (FIG. 15C),rod616 comprises a C-shapedfeature618 through whichtether534 may be threaded.Rod616 is then inserted into a termination device similarly to the example shown inFIG. 15B. Feature618 may be, for example, a C-shaped fastener that snaps aroundtether534. In these implementations,tether534 may comprise a knot or othersuitable feature620 that cannot pass through C-shapedfeature618, thus improving the ability ofrod616 to pulltether534 into a termination device.
• In the implementations shown inFIGS. 15D-15F,rod622 comprises through-holes624 oriented approximately perpendicular to a long axis of the rod andflat portions626 and628 oriented approximately parallel to the long axis of the rod. Tether534 runs alongflats626 and628 when it is threaded throughholes624. This configuration allowsrod622 andtether534 to remain within a round profile. In the implementation shown inFIGS. 15G and 15H,rod630 comprisesholes632 oriented approximately perpendicular to a long axis of the rod andgrooves634 oriented approximately parallel to the long axis. Tether534 runs alonggrooves634 when threaded throughholes632. In these implementations also, the rod and tether may remain within a round profile. Other orientations of holes, flats, and grooves may also be suitable in these implementations.
• After a plurality of tethered anchors have been secured to tissue, in some embodiments the device used to deploy and secure the anchors may be used to apply tension to the tether to tighten the tissue. In other embodiments, a termination device into which the tether has been loaded may be used to apply the tension. In some embodiments, the deployment or termination device is advanced along the tether to a location at or near the proximal end of the tethered anchors. The device may then be used to apply an opposing force to the most proximal anchor while tension is applied to the tether to cinch it. The opposing force has a component counter to the tensioning force applied to the tether, and thus stabilizes the most proximal anchor as the tether is cinched. The opposing force may be applied, for example, by contacting the most proximal anchor with the deployment or termination device. The deployment or termination device may be an intravascular device.
• During a tissue tightening procedure, e.g., an annuloplasty procedure, a locking or fixing feature should be applied to the cinching tether to fix its length so that tension is maintained. If anchors are being secured to the tissue, and the cinching tether is threaded through the anchors to tighten the tissue via the anchors, the end of the cinching tether should not slide through an eye of the most proximal anchor.
• Various fixing or locking features and methods can be used to fix the end of the cinching tether so that it does not slip through the most proximal anchor. These features and methods can be used intravascularly. Several types of locking features can be used. These locking features generally fall into three categories: features that cannot slide; features that can slide until they hit a stop; and features that are designed to slide somewhat before locking, relieving some tension in the tether. For the latter type of features, an extra length of tether is provided to accommodate the slippage. The locking features can be applied to the most proximal anchor itself, or they can be applied to the tether. In addition, the tether can be fixedly coupled to the most proximal anchor by deforming the second anchor, e.g., by use of a device that can bend or twist the second anchor.
• Knots can be used as locking features for tethers. One type of knot that can be used is a slip knot positioned near the most proximal anchor, as illustrated inFIG. 16A. Tether534 is cinched until the tissue shape (e.g., valve tissue) is as desired. The proximal end of the tether is threaded through aloop710 of atie711 havingslip knot712. Theloop710 is slid overtether534 in a distal direction until it reaches or is close to the most proximal anchor.Tie711 is pulled to slide through713 to tighten the knot aroundtether534 such that the tether is locked in place and will not slip past the most proximal anchor, e.g., through an eye of the most proximal anchor. Many different types of slip knots may be used, including Roeder's knots. In some variations, a secondary slip knot can be applied to the end, slipping portion and/or non-slipping portion oftie711 tofurther lock knot712 in place.Tie711 can be passed inside acatheter713. In another variation,tether534 and tie711 are joined with knots, including half knots, to further lockknot712 in place.
• In other variations, as shown inFIG. 16B, tether.534 can be looped throughanchors526, with aslip knot715 positioned near most proximal anchor closing the loop. Tether534 can be looped through the eye of most distal anchor and then threaded through other anchors in any suitable fashion that allows tension on thetether534 to be adjusted as necessary. For example, as illustrated inFIG. 16B,tether534 can be looped through most distal anchor, then both strands can be threaded through the remaining anchors, except for the most proximal anchor. On the most proximal anchor, just one of the strands may be threaded through, while the other strands goes around the last anchor. Thus, the anchor forces the two strands of the knot to exit at angles relative to one another so that when tension is exerted on those strands, a knot such as the Roeder's knot self tightens.Slip knot715 can be pushed to cinchtether534 as desired and locktether534 into place. A knot pusher can be used to simultaneously cinch and push the knot. As the knot is pushed,tether534 adjusts, sliding through the most distal anchor such that two sides of the loop oftether534 are approximately equal in length. The force of tissue expanding outward can causeknot715 to tighten further. For the most distal anchor,tether534 can be threaded through a guided feed (not shown), such as a slotted device coupled to most distal anchor, to lessen friction as thetether534 is cinched. A secondary tie having a secondary slip knot, for example, similar to tie711 as shown inFIG. 16A, can be applied totether534 to help tightenknot715. In addition, two knots (not shown) can be used for the variation shown inFIG. 16B. The tether can include a loop having a first slip knot positioned proximal the most proximal anchor and a second slip knot positioned distal the most distal anchor. The two slip knots positioned at opposite ends of the plurality of tethered anchors can be used to adjust the length and tension in the loop of the tether.
• In other variations illustrated inFIG. 16C,tether534 can be threaded through allanchors526 except the mostproximal anchor626. At the distal end oftether534 is ablock716, e.g., a knot or a washer or the like, to prevent the most distal anchor from passing over the most distal end oftether534. Asecond cinching cable717 is threaded through only the mostproximal anchor626 and hasblock718, e.g., a knot or a washer or the like, to prevent the mostproximal anchor626 from passing over the most proximal end ofcable717.Cable717 is used to tie aslip knot719 aroundtether534 just proximal the second most proximal anchor, such thatknot719 can slide alongtether534.Knot719 is pushed alongtether534 in a distal direction to cinchtether534, e.g., bypusher720. Expanding force of tissue can further tightenknot719.
• In other variations as shown inFIG. 16D, a slidinghalf knot721 proximal of the most proximal anchor is passed distally down the length oftether534 to the most proximal anchor.Half knot721 is held open as it is slid distally down the length oftether534. Whenhalf knot721 is in the desired position, the device holding the knot open is released, and a pusher may push on the knot in a distal direction to tighten the knot. The knot can be held open by any suitable method. For example, as illustrated inFIG. 16E,pusher727 can include aretractable member728, e.g., a wire form made from any suitable material such as a nickel titanium alloy, that holdshalf knot721 open. Whenhalf knot721 is positioned as desired to locktether534 in place,retractable member728 is retracted to releasehalf knot721. Alternatively,knot721 can be held open by sliding the knot around a round or elliptical roller (not shown) having a large enough cross-sectional diameter to prevent the knot from becoming tight and therefore not sliding.Knot721 can also be held open by placing pins (not shown) in the two loops of the half knot such that the loops, and therefore the knot, cannot tighten. In somevariations knot721 itself is large enough that it cannot pass through the eye of most proximal anchor. In other variations, there is a washer or other blocking object722 slidably coupled totether534 that cannot pass through the eyelet of most proximal anchor. For any of the variations including sliding a half knot, a mechanical feature that holds the tether slack before, during, or after sliding the half knot can be included. By holding the tether with sufficient slack, the knot generally will not tighten.
• As shown inFIG. 16D, an additional cinching cable723 having a knot or other impediment724 on its distal end can be threaded through the most proximal anchor so that the cinching cable723 cannot pass through the most proximal anchor when pulled in a proximal direction.Half knot721 can then be tied with both cinching cable723 andtether534, creating a bulkier knot. In some variations, both cinching cable723 andtether534 are passed through washer or blocking object722. In other variations, two tethers can be threaded through all anchors. The two tethers can then used to make a half knot.Tube727 can be pushed againsthalf knot721 to push the knot in a distal direction to create a fully locked knot, holding the tethers in place.Tube727 can have a saddle (not shown) to aid in pushing. In some variations, the cinching tether or tethers can exit the side of pushingtube727.
• As shown inFIG. 17A,tether734 can haveprotrusions703 that allowtether734 to slide throughanchors726, e.g., through anchor eyelets, in one direction, but not in the opposite direction.Protrusions703 can be arrow-shaped, V-shaped, cone-shaped, triangular, or have any other suitable shape or geometry that allows them to pass in one direction through an opening but not in the reverse direction. Alternatively,protrusions703 can comprise other shapes or objects, such as knots. In some variations, as shown inFIG. 18A, the mostproximal anchor726′ has an eyelet with a reduced cross-sectional dimension such thatprotrusions703 can pass astether734 is pulled in a proximal direction through the eyelet ofanchor726′, but not whentether734 is pulled in a distal direction. Tether734 can be ratcheted into a desired tension assequential protrusions703 are passed through the mostproximal anchor726′. In other variations, as shown inFIG. 18B, acollar705 is positioned alongtether734 proximal to mostproximal anchor726′. Tether734 is threaded through anopening706 incollar705. Opening706 can expand slightly such thatprotrusions703 can pass through opening706 when they are pulled through in a proximal direction, but not when pulled in a distal direction. For example, opening706 can be a generally fixed opening andprotrusions703 can be of such a shape as to pass in the proximal direction throughopening706 but not in the distal direction. Thus, assequential protrusions703 are passed throughopening706,tether734 is cinched tighter and locked into place.
• Protrusions703 can be of any type and provided by any suitable method. For example,tether734 includingprotrusions703 can be formed of sheet metal, and then processed, e.g., by electropolishing or any other suitable technique, to remove sharp corners and edges. Tether734 andprotrusions703 can also be formed of plastic, e.g., a plastic comprising a TEFLON® fluoropolymer, or polyester. Alternatively,protrusions703 can be added totether734 in a separate step, e.g., by threading cones onto a suture and fixing the cones in place along the suture at defined intervals. The cones can be bonded or otherwise attached to or coupled with the suture.
• Other methods for fixing the end of a tether such that tension is maintained include threading the tether through a path having numerous twists, turns, and or bends such that slippage of the tether is prevented.
• A self-kinking tube can be used to clamp or lock a tensioned tether into place during termination. As shown inFIG. 19A,tube870 that has been pre-kinked along its length can be provided. A force can be applied totube870 to compress it axially to maintain its kinked state, e.g., by providing a spring extending between the ends of the tube. As illustrated inFIG. 19B, aspring871 havingspring elements872 can be provided.Spring871 can be placed in a collinear arrangement withtube870 such that ends ofspring871 are coupled to the ends oftube870. Thus,spring871 can assist in applying axial force totube870 to maintain its kinked state. For example,spring871 can be placed overtube870, or alongside and generally parallel withtube870. A second straight tube873 (e.g., a catheter) can be provided which fits overspring871 by compressingspring elements872 inwardly (FIG. 19C). This causesspring871 to elongate, and therefore to elongatekinked tube870 into a generally straightened state (FIG. 19C). Tether534 can be threaded through straightenedtube870 such thattether534 can move back and forth throughtube870 freely. When it is desired to fixtether534 during termination, theforce causing tube870 to be at least partially unkinked can be released, allowingtube870 to be restored to its kinked state to locktether534. For the examples illustrated in FIGS.19A-C,second tube873 can be removed fromspring871, thus allowingspring elements872 to recover to their curved state, reducing the length ofspring871, and causingtube870 to recover to its kinked state. Oncetube870 is kinked,tether734 can no longer freely move and is fixed into place.Tube870 can be made of any material suitable for use inside the human body and that can be transferred between a straightened and kinked state, such as nylon, PEBAX®, polyurethane, polyethylene terephthalate, polyethylene, polypropylene or polyetheretherketone.Spring871 can comprise any spring material suitable for use within the human body, such as stainless steel, titanium, or nickel titanium alloys or polyetheretherketone. Althoughspring871 has been depicted as having a basket shape for purposes of illustration,spring871 can have any suitable shape.
• The tether can be threaded through a clamp to lock it into place during termination. Clamping can involve applying a force to cause two surfaces (e.g., clamp jaws) of a locking feature together to clamp the tether. Clamping can also involve applying a force to separate two surfaces of a locking feature, passing the tether between the surfaces, and releasing the force to clamp the tether between the surfaces. In some variations, the surfaces of the clamp jaws will be at least partially roughened, toothed, or made to have adhesive properties to hold the tether. For example, as illustrated inFIG. 20A, two sides of aclamp880 can form aninterlocking profile882, e.g., a stepped profile or other profile having corners. Tether534 is threaded throughholes881 such thattether534 traversesprofile882 whenclamp880 is open. Asclamp880 is closed,tether534 is forced to follow the tortuous path imposed on it by the interlockingprofile882. Clamp880 can be closed by any suitable mechanism, such as with a closure, or with a spring hinge. Ifclamp880 is closed by a spring hinge, it can be propped open using a propping element (not shown) whiletether534 is threaded throughholes881, and before it is desired to fixtether534 into place. When it is desired to lock downtether534 during termination, the propping element can be removed. Alternatively, a spring hinge can have an open position, allowingtether534 to slide freely throughclamp880. When it is desired to fix the tether, the spring hinge can be snapped into a closed position. Clamp880 can have any suitableinterior surfaces883 such that when the clamp is closed, surfaces883 preventtether534 from slipping. In other embodiments, the clamp can have numerous structural features along its length. For example, as illustrated inFIG. 20B,clamp1100 has a saw-toothed surface on inner surfaces of bothjaws1110 and1112 along its longitudinal axis, andtether534 is threaded throughclamp1100 along its longitudinal axis.Clamp jaws1110 and1112 can be locked together when it is desired to fixtether534 upon termination by any suitable mechanism, such as by using a hinge or clamping mechanism. Besides the stepped surface illustrated inFIG. 20A and the saw-toothed surface illustrated inFIG. 20B, other suitable clamping surfaces can be used, including roughened, notched, etched, scored, and the like.
• FIG. 21A illustrates additional examples of toothed clamping devices that can be used to lock the tether during termination. InFIG. 21A, clamp885 havingfirst side886 with protrudingfeatures887 attached thereto and secondopposing side888 with protrudingfeatures889 attached thereto is provided. Protruding features887 and889 are placed in an alternating manner along the long axis A-A′ ofclamp885 and extend into the interior volume ofclamp885 such that the only path down the long axis is tortuous whenclamp885 is closed. Whenclamp885 is opened (FIG. 21B), a generally unobstructed path down the long axis A-A′ of the interior ofclamp885 exists. Thus tether534 can be threaded through axis A-A′ ofclamp885 in its opened state. Whenclamp885 is closed (FIG. 21C),tether534 will be forced in a tortuous path byprotrusions887 and889, and will thus be fixed into place. In some variations, the rest state ofclamp885 is closed, and held open, e.g., by a propping mechanism, tothread tether534 throughclamp885 and to adjust tension ontether534. When it is desired to locktether534,clamp885 is allowed to close, e.g., by retracting the propping mechanism. In other variations, the clamp is open during its rest state so thattether534 can easily slide through its interior. When it is desired to fixtether534, an external element clamps or deformsclamp885 such that it is in a closed state andprotrusions887 and889lock tether534.
• The tether can be threaded through a coil or spring890 in a direction generally orthogonal to the expandable direction of the spring.
• Other clamping schemes can be used to lock a tether into place during termination. Several factors can influence how well a clamp holds a tether. These include surface finish, surface area, elasticity of material, configuration of the tether in the clamp, and clamping force. For example, surfaces that are roughened, toothed, scored, etched, textured, or sticky (i.e., have adhesive properties) all increase the holding force of the clamp. In addition, a larger clamping surface area generally increases the holding force. In some cases, more elastic materials used for clamp jaws can provide increased hold on cinching tethers. Designing a clamp so that it holds the cinching tether in a bent, folded, curved, or other generally nonlinear configuration can increase the holding force. A higher clamping force applied to the tether via clamp jaws increases the holding force of the clamp. All of these variables can be adjusted according to clamp design to provide desired features, e.g., size, cost, ease of use, installation method, and biocompatibility for area or type of use. Certain clamp features may be desired for use with certain tether types or materials or diameters, for use with certain tension ranges, or for certain tissue types. Clamping devices can be used to clamp onto the tether such that the tether cannot move past the most proximal anchor. Alternatively, clamping devices can be used to clamp the tether to the most proximal anchor.
• A clamping device, such as a clip, formed of a single piece of metal can be provided to lock the tether during termination. An example of such a clamping device is illustrated inFIG. 22. For the embodiments shown inFIG. 22,clamp910 is closed in its rest state. Before locking,tether534 is threaded throughclamp910, between propped-open jaws911 and912. The jaws can be propped open by proppingmechanism913, e.g., a wire, a tube, or any suitable mechanism. After the tether is in its desired position, the propping mechanism is withdrawn such thatjaws911 and912 clamp down ontether534. The clamping device illustrated inFIG. 22 can be used either to clamp directly ontotether534 or to clamptether534 to most proximal anchor.
• Clamping devices with expandable, deformable mesh may be used to clamp tethers during termination. Examples of such clamping devices are illustrated inFIG. 23A-C. As shown inFIG. 23A,expandable member901, e.g., a balloon, encased or partially encased in anexpandable mesh element902 is provided withintube900, e.g., a catheter. Tether534 is threaded betweeninner wall903 oftube900 andouter wall904 ofexpandable mesh element902. As shown inFIG. 23B, asexpandable member901 is expanded,tether534 is compressed between meshouter wall904 and tubeinner wall903. In some variations, it may be desired to provide a mesh element having a textured surface, roughened surface, or adhesive properties to increase friction withtether534. For example, as illustrated inFIG. 23C,mesh element902 having flanges or other protruding features905 can be provided that is capable of catching and/or compressingtether534.Mesh element902 can be made of any suitable material, e.g., metal, polymer, or any suitable type of fiber, and can have a tubular, or any other suitable, configuration.Tube900 can be made of any suitable material, and can be rigid or flexible. For example,tube900 can include an elastomer.Inner wall903 oftube900 can be coated with an elastomer or adhesive. The walls oftube900 can be interrupted, e.g., by providing holes with which the metal mesh can interact, e.g., by at least a partially interlocking interaction. In some variations, the mesh is self-expanding. In these variations,expandable member901 may be omitted. A sleeve (not shown) may be installed around self-expanding mesh to constrain the outer diameter of the mesh. When the sleeve is removed, e.g., by retraction, the mesh is able to expand outwardly to locktether534 between the mesh andtube900. Self-expanding mesh may be made of materials such as shape-memory metals or superelastic metals.
• A hollow locking element having features that protrude towards its interior can be used to fixtether534 during termination. An example of such alocking element930 is provided inFIG. 24A. Tether534 is threaded throughhollow locking element930.Features931, such as barbs, flaps, or prongs, protrude inwardly. An inner cross-sectional dimension ofelement930 is small enough such that at least some offeatures931contact tether534 as it is threaded throughelement930.Features931 are angled in a proximal direction, such that lockingelement930 can be slid in a distal direction until it reaches or is close to mostproximal anchor526. Becausefeatures931 are angled in a proximal direction, and at least some offeatures931contact tether534, motion in the opposite direction (i.e., slidingelement930 in a proximal direction) will be opposed byfeatures931 exerting force againsttether534. In some cases, features931 may be flexible to ease the pulling oftether534 throughelement930 in a distal direction during the cinching oftether534. In some variations, features931 can be sharp enough or small enough in dimension so as to become interlocked with inter-thread spaces intether534. Lockingelement930 can be prepared by any suitable method. For example, as illustrated inFIG. 25, V-shapedgrooves932 can be cut into a metal tube (e.g., by using a laser). The resulting V-shaped metal pieces can be bent inward, forming a cross-section ofelement930 similar to that illustrated inFIG. 24A. A plug that fits into a collar can be used to lock the tether during termination.
• Collars comprising deformable materials can also be used to lock the tether during termination. Examples of these variations are illustrated in FIGS.26A-B andFIG. 27. As shown inFIG. 26A,tether534 can be threaded through acylindrical collar1020 anddeformable ring1024 positioned in the interior ofcollar1020 and seated on abase1022 ofcollar1020.Ring1024 can be any suitable deformable ring, such as an O-ring. Before locking the tether during termination,tether534 can slide freely throughcylindrical collar1020. When fixing the tether into place, pushingelement1026 is pushed into the interior ofcollar1020 such thatring1024 is compressed, thus reducing its inner diameter (FIG. 26B).Ring1024 is chosen such that its inner diameter when compressed is small enough to restrict movement oftether534. Alternatively,1024 could be a shape other than a ring, such as two or more portions which are compressed so that they griptether534 between them. Pushingelement1026 can be pushed intocollar1020 by any suitable technique. For example, the interior ofcollar1020 andelement1026 can be threaded, such thatelement1026 can be screwed down tocompress ring1024. Alternatively, pushingelement1026 can have a friction fit withcollar1020 to compressring1024. In other variations, the pushing element is spring loaded such that it fits intocollar1020 and can compressring1024. In still other variations, an additional cap or spring (not shown) can be applied to pushelement1026 down tocompress ring1024. As illustrated inFIG. 27, the interior ofcollar1030 and the exterior of pushingelement1032 can be configured such thatelement1032 is ratcheted along the interior ofcollar1030 when force is applied, thus compressingring1034 and constrictingtether534 such that it cannot slide. For the embodiments shown in FIGS.26A-B andFIG. 27, rings1024,1034 can have any suitable cross-sectional shape and be made of any suitable material. For example, in some cases, it may be desired that rings1024,1034 have round or polyhedral, e.g., octahedral, cross-sectional shapes. Material forrings1024,1034 can be chosen for any desired property, such as deformability, biocompatibility, or coefficient of friction with the material used fortether534. In other variations, the tether can be clamped by altering a path of the tether through a locking feature to increase the frictional forces on the tether. For example, the tether can be threaded through a network of rollers or pins to lock the tether in place during termination.
• As shown in FIGS.28A-B, clamps containing actuated clamping elements can be used to lock the tether in place during termination. For example,clamp1060 containingclamping elements1064 and1066 can be used.Clamp1060 hasfirst side wall1062 with a profiledinner surface1072 andopposite side wall1068.Actuator channel1074 is provided betweenside wall1068 andelements1064 and1066.Elements1064 are arranged generally collinearly with and alternated withelements1066 along a length ofclamp1060, such thatelements1064 protrude further intoactuator channel1074. Tether534 is threaded throughchannel1076 betweenelements1064,1066 and profiledinner surface1072 offirst side wall1062. Asactuator1070 is forced intoactuator channel1074, actuatingelements1064 are preferentially pushed intochannel1076, creating a tortuous path fortether534 that is threaded through channel1076 (FIG. 28B). In some cases, actuatingelements1064 have rounded edges whereactuator1070 will slide against them to force them intochannel1076. Profiledinner surface1072 can have any suitable profile to locktether534 during termination. In some variations, a locking device made from a single piece can be used to accomplish the same locking principle as exemplified in FIGS.28A-B. For example, as shown inFIG. 28C,locking device1080 can be used.Locking device1080 comprises afirst side wall1082 having first profiledinner surface1092.Middle wall1084 having second profiledinner surface1090 is provided opposite firstinner surface1092.Second side wall1086 is provided, separated frommiddle wall1084 byactuator channel1087. Tether534 is threaded throughchannel1084 betweensurfaces1090 and1092. Before lockingdevice1080,tether534 can move feely throughchannel1084. When it is desired to locktether534 usingdevice1080, anactuator1091 can be inserted intoactuator channel1087, forcing profiledsurfaces1090 and1092 together, thus creating a tortuous path fortether534, and preventing it from slipping throughdevice1080.
• Adhesive may be used to facilitate the locking of the tether. For example, drops of adhesive material may be applied, e.g., released from an applicator, to bond the tether to any locking mechanism. For example, adhesive may be applied to knots (see FIGS.16A-E, for example), clamping devices (seeFIGS. 19-23, for example), or to protrusions on the tether (seeFIG. 17 and18A, for example). Pressure activated or pressure sensitive adhesives may be used. For example, with reference toFIG. 23A-C, the exterior ofmesh902 and or the interior oftube900 can be at least partially lined with a pressure activated or pressure sensitive adhesive.
• After the tether is locked to prevent it from slipping through the most proximal anchor, the excess tether must be cut so it can be removed during termination. Generally, the tether is cut proximal the locking mechanism. In many cases, it is desired to cut the tether as closely as possible to the locking mechanism, while leaving enough excess length to allow for any slippage that may occur. The following examples provide various methods and devices for cutting the excess tether.
• In some variations, concentric tubes can be used to cut excess tether. One concentric tube can be advanced relative to another concentric tube to shear off excess tether at a desired position. Alternatively, one concentric tube can be rotated with respect to another concentric tube to cut the tether. For example, as shown inFIG. 29A, in some embodiments,tether534 has been cinched and is fixed relative to most proximal anchor by lockingfeature744. Although lockingfeature744 is shown herein as separate from the most proximal anchor for illustrative purposes, lockingfeature744 can also be part of, or integral with, the most proximal anchor. In addition, lockingfeature744 can be located external or internal to a catheter or other intravascular device. Tether534 enters acatheter745 and exits through aside opening746. Tether534 can be loaded intocatheter745 by any suitable method, for example those described herein inFIGS. 14-15. A cuttingtube747 having anedge748 sharp enough to cuttether734, e.g., a metal tube having a sharpened edge, is attached to a flexible tube or to a rod and is advanced inside the catheter over side opening746 from whichtether534 extends. As it is advanced overtether534, cuttingtube747 can shear off the excess portion of the tether. In some variations, as shown inFIG. 29B, cuttingtube747 is advanced against a base749 that can assisttube747 in cutting throughtether534.Base749 can for example be a block positioned on the interior ofcatheter745. Alternatively,base749 can be part ofcatheter745 or be formed integrally withcatheter745.Base749 can be formed of any suitable material, e.g., any elastomeric or rigid material. In some variations, cuttingtube747 can be spun or rotated to improve cutting. The profile of cuttingtube747 can be any suitable shape, for example V-shaped or triangular, as shown in FIGS.29C-E. In addition, cuttingtube747 may have a serrated or saw-tooth pattern of sharp protrusions around its perimeter to aid in cutting. Such variations may be used for example whentube747 is spun or rotated during the cutting process. In some variations, as shown inFIG. 29F, cuttingtube747 can be positioned in front ofhole746 such that cuttingtube747 can be pulled in a proximal direction towardhole746 to cut tether534 (indicated by solid arrow).
• Alternatively, a cutting tube can be provided that is external to acatheter housing tether534. For example, as shown inFIG. 30A,tether534 extends throughcatheter745 and exits throughhole746. Again,tether534 can be loaded intocatheter745 by any suitable method, including methods described herein. Cuttingtube750, which can be a sharpened metal tube, can slide along the exterior ofcatheter745. In some variations, cuttingtube750 is attached to asecond tube751 which slides along the exterior ofcatheter745.Second tube751 can be flexible. As cuttingtube750 is advanced in a distal direction toward hole746 (indicated by solid arrow), end753 oftube750 can severtether534. As shown inFIG. 30B, a base754 can be positioned alongcatheter745 such thattether534 is pushed against base752 as cuttingtube750 is advanced towardhole746, thereby improving the cutting process. As also shown inFIG. 30B, a cover orshroud754 can be provided around cuttingtube750 in some variations to prevent sharpenedend753 from catching on tissue or the like. In some variations, cover754 is attached tosecond tube751.
• Cutting tubes can have any suitable shape. For example, as shown inFIG. 31A, cuttingtube760 can have a V-shape along its perimeter or other notched feature designed to channeltether534. Alternatively, cuttingtube760 can have a curved profile (FIG. 31B), an angled profile (FIG. 31C), a serrated profile (FIG. 31D), or a saw tooth profile (not shown). The latter two variations may be useful when cuttingtube760 is rotated or spun during the cutting process. In some variations, the perimeter ofhole746 is sharpened to cuttether734. The cutting tubes can be configured such that they operate either externally or internally tocatheter745.
• In some variations, cutting tubes can sever the tether by cutting in a direction roughly perpendicular to the long axis of the catheter, e.g., by rotating one concentric tube relative to a second concentric tube. As illustrated inFIG. 32A,tether534 enterscatheter745 and exits throughhole746. Cuttingtube770 can be configured such that when it is rotated about the long axis A-A′ ofcatheter745, it can slicetether534. For example, cuttingtube770 can have an angled shape such that when it rotates about axis A-A′ it cutstether534. In some variations, cuttingtube770 is attached to aflexible tube771. In other variations, a blockingstructure773 is disposed oncatheter745.Blocking structure773 can have any suitable shape, and can serve as a base against whichtether534 can be pushed during the cutting process. Block773 can be attached to, part of, or integral withcatheter745. Alternatively, as shown inFIG. 32B, the cuttingtube772 can have a profiled shape to enable it to cuttether534 in a direction generally orthogonal to long axis A-A′ ofcatheter745 as it is rotated around axis A-A′. Optionally, a blockingstructure774 can be provided oncatheter745 such thattether534 is pushed againstblock774 during the cutting process. Block774 can be any suitable shape or have and suitable configuration and can be attached to, part of, or integral withcatheter745. Cutting tubes such as those illustrated in FIGS.32A-B can be configured such that they are internal to the catheter.
• In some variations, a pair of concentric cutting tubes can be used to cut the tether. The concentric tubes can be either internal or external to the catheter. As illustrated inFIG. 33, the two concentric cutting tubes780 and781 can be rotated about the long axis A-A′ ofcatheter745 in opposite directions (indicated by solid arrows). Thus, the cuttingedges782 and783 can cuttether534 in a scissor-like fashion. Cuttingedges782 and783 can be sharpened in such a way to enableedges782 and783 to pass each other as closely as possible.
• In some variations, the tether does not exit the catheter through a side hole. In these variations, a cutter can be mounted on a tube concentric to the catheter, either externally or internally, and rotated to cut the cable. For example, as shown inFIG. 34A,excess tether534proximal locking feature744 enterscatheter792 through itsend opening794.Optionally catheter792 can havelips793 that restrict the diameter of theend opening794. Aconcentric tube791 has attached thereto ablade790, which can be rotated to severexcess tether534.FIG. 34B illustrates the operation ofblade790 ontether534 as it is rotated.
• Alternatively, as shown inFIG. 34C, twoconcentric tubes795 and798 can be provided.Tube795 hasblade796 attached to its end;tube798 hasblade797 attached to its end.Blades796 and797 are oriented generally perpendicular to the long axes oftubes795 and798. Thetubes795 and798 are rotated in opposite directions about their respective long axes to cuttether534.FIG. 34D illustrates the operations ofblades796 and797 ontether534 as they are rotated.Blades796,797 can be configured such that sharpened edges pass each other closely enough and at such angles to facilitate cutting. Thecutting blades790,796, and797 can have any suitable shape, e.g., angled, V-shaped, or curved. Theconcentric tubes795,798 can be mounted either external or internal tocatheter792. For example, one tube can be external while the other is internal.
• In some variations, as illustrated-inFIG. 35A, a hook, loop or the like can be used to engage the tether between the most proximal anchor and the distal end of the catheter. Tether534 is cinched, locked into place by lockingfeature744, and threaded lengthwise throughcatheter801 inchannel807 between an inner wall ofcatheter801 and cuttingtube802. Cuttingtube802 has a sharpenededge803 on its distal end.Assembly804 havinghook805 on its distal end is configured such that it extends through cuttingtube802.Hook805 engages aportion806 of the excess tether that extends proximally from lockingfeature744. The length oftether534 threaded throughchannel807 is pulled in a proximal direction. Hook805 can pullportion806 oftether534 in a proximal direction (indicated by solid arrow), forcing the tether against sharpenededge803, which severs the excess tether. Alternatively, hook805 can include a sharpened edge or blade such that it can cuttether534.
• As described above, the tether cutter may comprise any appropriate structure or material. For example, in addition to the cutting tubes described above, the tether cutter may cut by heat, electricity, chemical reaction, or the like. For example, the tether cutter may comprise an electrode or filament through which electrical energy may be applied to cut the tether.
• In other variations, as illustrated inFIG. 35B,tether534 can be threaded through acollet810 comprising ahousing811. Housing811 can be coupled tocatheter817. Tether534 is threaded throughcollet810 such that aloop812 oftether534 extends in a proximal direction fromcollet810.Collet810 can have any suitable shape, e.g., U-shaped or C-shaped. A hook orloop813 coupled toapparatus815 can be used to engageloop812. Apusher814 can be used to apply force in a distal direction to collet810 whilehook813 is pulled in a proximal direction byapparatus815. Ashook813 is pulled in a proximal direction,tether534 is forced againstcutting blade818. Cuttingblade818 can have any suitable orientation or configuration such thattether534 can be forced against a cutting surface of cuttingblade818. Cuttingblade818 can be attached to, part of, or integral withhousing811. Optionally, acollar816 can be placed betweencollet810 andpusher814 to aid in applying force tocollet810. In some variations,collet810 can be placed internal tocatheter817, andhousing811 can be omitted. In those variations,catheter817 can comprise a cutting blade (not shown) attached to, part of, or integral with the catheter and configured such that asloop812 oftether534 is pulled in a proximal direction,tether534 is forced against the cutting blade. In some variations, hook813 can be capable of cuttingtether534 as tension is applied. In those variations, cuttingblade818 maybe omitted. InFIG. 35B is that hook orloop813 draws the end of the tether is drawn intocollet810. Then,tube814 pushes down816 around810 to lock in thetether534. The assembly of tether, collet andcollar534,810,816 is released all together, becoming an element which locks the tether and prevents slipping through the most proximal eyelet.
• In other variations as shown inFIG. 35C,tether534 can be threaded through a one-way locking mechanism820 provided internal to catheter821.Locking mechanism820 can be separate from, e.g., part of a separate tube, or attached to catheter821.Locking mechanism820 comprises opposing angled flaps824. The flaps are angled in a proximal direction and closely spaced such that the tether can be pulled throughmechanism820 in a proximal direction forming aloop822 extending in a proximal direction frommechanism820. Ahook823 coupled toapparatus824 engagestether loop822. Once the tether is cinched to the desired tension by pullingloop822 proximally and locked into place by lockingdevice744,tether534 can be pulled in a distal direction and cut by cuttingedges825 provided as part offlaps824. Optionally, cuttingedges825 can be serrated or comprise teeth to aid in cutting.FIG. 35C illustrates a locking device that is an alternative to the device shown inFIG. 35B. Here, instead, theloop822 is pulled through and locked. Then, the whole thing (locking flaps and loop) is released to be the “lock” that prevents slipping the tether from slipping through the eyelet.
• As shown inFIG. 36A, cuttingapparatus834 comprising singleangled flap826 can be used to cut excess tether.Cutting apparatus834 can be internal to a catheter (not shown) or part of a catheter.Cutting apparatus834 compriseswall828,opposite flap826. In some variations,wall828 is a wall of a tube. In other variations, bothsurface828 andflap826 are formed from the same tube.Flap826 is angled in a proximal direction and abuts or is in close proximity towall828. Tether534 can be threaded betweenflap826 andwall828 by pulling in a proximal direction. However, when force is applied to pulltether534 in a distal direction, cuttingedge829 offlap826 digs into and severstether534.
• As shown inFIG. 36B, in some variations acutting apparatus835 comprising multiple angled flaps can be provided. Several spaced apart or staggeredflaps830 having cutting edges833 are providedopposite walls836.Flaps830 are angled in a proximal direction and abut or are in close proximity to opposingwalls836. Tether534 can be threaded in a proximal direction betweenwalls836 and flaps830. Whentether534 is pulled in a distal direction, cutting edges833 dig in and operate to severtether534. For the variations shown in FIGS.35D-E, cuttingedges829,833 can be configured in any suitable manner, e.g., they may be sharpened blades, comprise a serrated cutting edge, or comprise teeth.
• As shown inFIG. 37, a cutter can be mounted on a balloon within a catheter. An excess portion oftether534 proximal to locking device755 enterscatheter837 at its distal end and exits throughside hole831.Expandable member832 is provided withincatheter837 and is adjacent to the section oftether534 withincatheter837.Expandable member832 can be, for example, a balloon, or more than one balloon. Attached to the perimeter of the expandable member are cutters (e.g., blades)838 capable of cuttingtether534.Expandable member832 can be expanded such thattether534 is pressed between an interior wall ofcatheter837 andcutter838. When in its expanded state,expandable member832 can be rotated along an axis generally parallel to the long axis ofcatheter837 to cuttether534. For example, ifexpandable member832 comprises a balloon, the balloon can be inflated to an amount such thatcutter838 is pressed againsttether534 but the balloon can still be rotated withincatheter837.Cutter838 can have any suitable shape or configuration. In some variations, asingle blade838 can be attached toexpandable member832 that is capable of cuttingtether534. In other variations,cutter838 can severtether534 by virtue of the blade being pressed into the tether by the expandable member, and thus need not be rotated to a substantial degree to severtether534. In some variations, a deformable mesh tube (not shown) can be provided to at least partially encaseexpandable member832. Thus, asexpandable member832 is expanded, it can cause the mesh tube to expand againsttether534, sandwiching it between the mesh andtube837 to holdtether534 in place.
• As shown in FIGS.38A-D,tether534 can be threaded through cuttingapparatus839 comprising a guillotine-like blade and an opposing cutting block. The excess portion oftether534 proximal locking device ormechanism744 is threaded intocatheter840 betweenside wall841 andpin842. Tether534 then traverses part of the inner diameter ofcatheter840 and is threaded betweenopposite side wall843 andpin844.Blade845 is provided on one side ofportion847 oftether534 extended betweenpins842 and844.Blade845 is mounted in any suitable manner, e.g., on abridge848 at least partially withincatheter840. Optionally, acutting block846 is provided acrosstether portion847 andopposite blade845. As tension is applied totether534 in a proximal direction (indicated by solid arrow),blade845 can be forced againsttether portion847, thus severing the tether.Blade845 can cut against-cuttingblock846, when present. As shown inFIG. 38C, a tool comprising a pair of blades connected with a pivot (e.g., a scissor-like tool)850 can be provided to cut the tether.Tool850 can operate within or external tocatheter840.Rods851 connected to opposingblades852 oftool850 can be pulled or pushed to severtether534. As shown inFIG. 38D,tether534 can be threaded betweencatheter side wall841 andpin842, betweenpin842 andpin860, and betweenpin844 andopposite side wall843. A sharpened blade or hook861 can be pulled acrosstether portion847 which extends betweenpins842 and844 to cuttether534.
• In some embodiments, cinchingtether534, fixedly couplingtether534 to most-proximal anchor526, and cuttingexcess tether534 are achieved using a single or integrated termination device (not shown). The termination device may comprise, for example, a catheter that can be advanced overtether534 that includes a cutting member and a knot, other attachment member, or a locking device for attaching or fixedly couplingtether534 to most-proximal anchor526. The termination catheter may be a steerable catheter. The termination catheter may be advanced overtether534 to a location at or near the proximal end of the tethered anchors526. The catheter may then be used to apply opposing force to the most-proximal anchor526 whiletether534 is cinched. The attachment member may be used to attachtether534 to most-proximal anchor526 and the cutting member may be used to cuttether534 just proximal to most-proximal anchor526. Such a termination device is only one possible way of accomplishing the cinching, attachment and cutting steps, and any other suitable device(s) or technique(s) may be used.
• A termination device can incorporate the termination functions of cinching the anchors with a tether, locking the cinching tether, and cutting away the excess length of the cinching tether in many ways. In some embodiments, a deployment device can deploy the anchors into the tissue to be tightened, and also cinch and lock the tether. A separate device can them be employed to cut the tether. Alternatively, the anchor deployment device can deploy the anchors into the tissue, cinch, lock and cut the tether. In other variations, three separate devices can be used in termination: an anchor deployment device; a second device to cinch the tether and lock the tether; and a third device to cut the tether. Termination functionalities can be integrated in any suitable manner in one or more termination devices. In addition, any number or combination of devices can be used in the termination procedure. Provided below are several possible architectures for termination devices that combine or integrate termination functions. These devices are only exemplary devices.
• For example, with reference to FIGS.23A-C, a balloon or otherexpandable member901 can be inflated to expand ametal mesh902 to clamptether534 betweenmesh902 and anouter tube900. Subsequently, a sharpened tube can be advanced to cut the tether. For example, if the tether is threaded through a side hole, the sharpened tubes that are provided in FIGS.30A-B,31A-D, and32A-B can be used to cut the tether as indicated in the figures. If the tether is not threaded through a side hole, cutters such as are illustrated in FIGS.34A-D can be used. Any suitable cutting technique can be also be used to sever the excess tether.
• In another example, with reference toFIG. 37 and FIGS.23A-C, the expandable member orballoon832 ofFIG. 37 can be inflated to expand a metal mesh (not shown inFIG. 37 but similar to mesh902 as illustrated in FIGS.23A-C) to compress thetether534 between the mesh andouter tube837.Cutting mechanism838 is mounted toexpandable member832.Expandable member832 can be configured such that the portion of the expandable member to whichcutter838 is mounted inflates after the metal mesh is expanded. For example,expandable member838 can comprise two separate balloons, one of which hascutting mechanism838 attached thereto. When the portion ofmember832 comprisingcutter838 is expanded,cutter838cuts tether534. Alternatively, a cutter orcutters838 can be rotated to severtether534. Once the tether has been cut, the mesh locking mechanism applied to the tether can be released, e.g., by advancing a pusher (not shown).
• In another example of an architecture of a termination device, with reference toFIG. 37 and FIGS.16A-E, a multi-stranded half-knot intether534 can be pushed down to locktether534 in place. Then expandable member can be inflated and rotated at least partially withincatheter837 such that cutters (e.g., blades)838cut tether534. Alternatively, with reference to FIGS.30A-B,31A-D,32A-B,33, and34A-D as examples, any type of tube-mounted cutter can be used to severtether534. For cutting devices such as those illustrated in FIGS.30A-B,31A-D,32A-B, and33, in whichtether534 is threaded through a side hole (e.g.,side hole746 in FIGS.30A-B) to enable cutting, additional tethers or cables used to formmulti-stranded knot721 can also be threaded through the side hole and cut. Any other type of cutting mechanism described herein can be used in combination with a tether locking mechanism employing a multi-stranded half-knot to fixtether534.
• With reference now toFIGS. 13A and 13B, one embodiment of asteerable catheter device560 is shown.Steerable catheter device560 may be used in a method such as that just described in reference toFIGS. 12A-12F, for example in performing a function similar to that performed bysecond guide catheter554. In other embodiments,catheter device560 may perform any other suitable function, e.g., any of the termination functions described herein. As shown,catheter device560 suitably includes an elongate catheter body having aproximal portion562 and adistal portion564. At least one tensioningmember568, such as but not limited to a tensioning cord, extends fromproximal portion562 todistal portion564 and is coupled with thedistal portion564 and at least onetensioning actuator570/572 on the proximal portion.Tensioning actuator570/572 may include, for example, aknob570 and abarrel572 for wrapping and unwrappingtensioning member568 to apply and remove tension. Tensioningmember568 is coupled withdistal portion564 at one or more connection points580. In some embodiments,catheter device560 includes aproximal housing571, handle or the like, coupled to the proximal end ofproximal portion562 via ahub576 or other mechanism.Housing571 may be coupled withtensioning actuator570/572 and may include one ormore arms574 for infusing fluid or for other functions. In the embodiment shown,arm574 andhousing571 include alumen567 that is in fluid communication with afluid lumen566 of the catheter body. Fluid may be introduced througharm574 to pass throughfluid lumen566 to provide, for example, for contrast material at the distal tip ofcatheter device560 to enhance visualization ofdevice560 during a procedure. Any other suitable fluid(s) may be passed throughlumens567/566 for any other purpose. Anotherlumen578 may be included indistal portion564, through which tensioningmember568 passes before attaching at a distal location alongdistal portion564.
• FIG. 13B showscatheter device560 in a deformed/bent configuration, after tension has been applied todistal portion564 by applying tension to tensioningmember568, viaknob570 andbarrel572. The bend indistal portion564 will allow it to conform more readily to a valve annulus, whilecatheter device560 in its straight configuration will be more amenable to passage through vasculature of the patient. Tensioningmember568 may be manufactured from any suitable material or combination of materials, such as but not limited to nickel titanium alloys, polyester, nylon, polypropylene and/or other polymers. Some embodiments may include two ormore tensioning members568 and/or two ormore tensioning actuators570/572 to provide for changes in shape ofdistal portion564 in multiple directions. In alternative embodiments,knob570 andbarrel572 may be substituted with any suitable devices, such as a pull cord, button, lever or other actuator. Various alternatives may also be substituted for tensioningmember568 in various embodiments. For example, shaped expandable members, shape memory members and/or the like may be used to change the shape ofdistal portion564.
• Generally,proximal portion562 of the catheter body is less flexible thandistal portion564.Proximal portion562 may be made of any suitable material, such as PEBAX® elastomers, fluoroethylenepropylene, nylon, polyethylene and/or the like, and may include a braided material, such as stainless steel, to provide stiffness and strength.Distal portion564 may be made of similar or other materials, but the braided material is typically not included, to provide for greater flexibility. Both proximal anddistal portions562/564 may have any suitable lengths, diameters, overall configurations and the like. In one embodiment the catheter body is approximately 140 cm in length and 6 French in diameter, but any other suitable sizes may be used in other embodiments.Proximal portion562,distal portion564 or preferably both, may be made from or coated with one or more friction resistant or lubricating material to enhance passage ofdevice560 through an introducer catheter and/or to enhance passage of a sheath or other device overcatheter device560.
• As described above, the termination devices described herein may be integrated termination devices, including tether cutters, locking features, tensioning devices, positioning devices, and the like. Provided below are exemplary termination devices including many of these features.
EXAMPLES
• In general, termination devices are designed to cinch, lock, and/or cut a tether (e.g., a suture or cable) as described herein. These devices can be used for any surgery where these functions (or combinations of them) are desired.FIG. 39 shows atermination device3901 having adetachable locking feature3905 that is releasably attached at the distal end of the termination device. This variation of a termination device has an elongatedtubular body3903 which may be flexible over all (or a portion) of its length. Thus, the termination device may be used in non-invasive procedures (e.g., percutaneously) or in invasive (e.g., open-heart) surgeries. The termination device shown inFIG. 39 is configured as a termination device catheter.
• Thetermination device3901 shown in cross-section inFIG. 39 is coupled to atether3910. The tether is threaded through the distal region of the termination device, particularly through thelocking feature3905 region at the distal end of the termination device. Although any locking feature may be included as part of the termination device, as described above, the locking feature shown inFIG. 39 is a clamping type locking feature in which aplug3913 fits into a hollow region of the locking feature and secures the tether between the plug and a wall of the locking feature. The tether passes through one or more openings (e.g. passages or holes) on the side of the device. Until the locking feature is secured, the termination device may be moved along the tether (e.g., by sliding), or the tether may be pulled through the termination device. Thus, the tether may be cinched by slinding the termination device down (distally) the tether.
• The openings through the termination device may be positioned such that the device can still easily slide along the tether (cinching cable). The tether may be threaded into the locking feature in such a way that it winds in and out of the tube, as suggested by the drawings. This may help the cable slide more easily, because under tension, the cable is free to wind less tightly around the features on the tube (e.g. closer to straight path). The cable may be threaded or coupled to the termination device during manufacturing or by the user. As shown inFIGS. 14A and 14B, a wire loop (or lasso) may be threaded through the openings. Then, after inserting the tether through the loop, the opposite end of the loop can be pulled to thread the tether through the openings. In some variations, the termination device may be slid along the tether until the tether is cinched to the desired size through the anchors, and then secured into position using the locking feature. For example, inFIG. 39, the locking feature is secured by moving theplug3913 into position within the hollow portion of thelocking feature3905, where it secures (holds) at least a portion of thetether3910. In the variation shown inFIG. 39, theplug3913 secures thetether3910 by compressing at least a portion of the tether between the plug and the inner walls of the locking feature and forcing the tether to wind through the tube through sharp turns. The locking feature (including the plug) may comprise features that prevent the release of the plug from the locking feature. For example, the locking feature may include adhesive or cement, or it may be at least partly deformable so that once the plug is inserted into the distal tip (e.g., locking feature) region of the termination device, it is retained at the distal tip.
• The termination device shown inFIG. 39 also includes a plunger or pushrod3915 for pushing theplug3913 into position to secure the tether within the locking feature of the termination device. The plunger shown may be slidable within the lumen of the termination device. In some variations, the rod may include guides (e.g., guiding the direction) or stops (e.g., limiting the distance that the rod may travel, or the force that may be applied by the rod). Thus, there may be motion-limiting features on the termination device and/or rod to prevent the rod from being pushed too far forward, or applying too much force, which could disturb either the locking mechanism or the tissue (e.g., after separation of the locking mechanism from the rest of the termination device).
• The locking feature may be detachably connected to the rest of the termination device. For example, the locking feature may be frangibly connected to the termination device, so that it can be detached from the termination device by breaking the connection between the locking feature and more proximal portion of the body of the termination device. Thus, the locking feature e.g., tube, clamp, knot, etc.) can be attached to the rest of the termination device so that it can be separated. The locking feature may be detachably connected to the rest of the termination device by any appropriate method. Thus, the locking feature (or a portion of the locking feature) may include a releasably attachment region. The releasable attachment region may include any region that can be separated or broken to release the locking feature from the elongate body of the termination device. For example, the releasable attachment region may comprise a region where the locking feature is fused to another region of the termination device (e.g., the distal region of the elongate body).
• In some variations the locking feature is fused by melting the materials comprising at least a portion of the locking feature and a portion of the rest of the termination device. The two materials may be fused together to different degrees (e.g., by varying the number of fuse spots or area of fusing) to adjust the force necessary to separate the two regions of the termination device. The different regions of the termination device may comprise different materials, or may comprise the same material. In some variations, the fused region comprises a third material used to secure the two regions together until they are separated. Being able to use different materials for different regions of the termination device may be advantageous if there are different material requirements for the different regions of the termination device, for example if the more distal portion of the termination device needs to be more flexible, and the more proximal region needs to be stiffer, or vice-versa.
• In some variations, the detachable locking feature of the termination device is attached to the rest of the termination device by a releasable attachment region that has been structurally weakened between the locking feature and the rest of the termination device. For example, the termination device may comprise a scored, etched, perforated, fractured, creased, slotted or dimpled region between the locking feature and the rest of the termination device. An example of a perforated region3120 is shown inFIG. 39. Thus, the locking feature may be composed of the same material as the rest of the termination device (or it may be made of-different materials that have been fused together). Scoring, perforating or other wise weakening the region between the locking feature and the more proximal portion of the termination device may allow the locking feature to be separated from the rest of the termination device when enough force is applied (e.g., to the termination feature by the push rod, as described above). The detachable locking feature could also be attached via an adhesive or a friction fit so that applying a certain amount of force causes the two regions of the termination device to separate, releasing the detachable locking feature. The two materials can also be welded, brazed, soldered, or snap-locked.
• As described above, the locking feature can be controllably released from the rest of the termination device by applying force. Force may be applied in any appropriate manner (e.g., pushing on a push rod, hydraulic force (e.g., saline etc.), magnetic force, pressure, etc.). For example, thesame push rod3915 used to push theplug3913 and secure the locking feature may be used to separate the locking feature from the rest of the termination device by simply pushing with additional force. In some variations, a separate force applicator may be used to secure the locking feature (e.g., a push rod) and to separate the locking feature from the rest of the termination device (e.g., a second push rod). Furthermore, the amount of force required to release the detachable locking feature may be predetermined. In variations where the locking feature is locked or triggered by the same force applicator (e.g., push rod), the force required to detach the locking feature may be greater than the force required to secure the locking feature (locking the tether). For example, the termination device may be configured to release the detachable locking feature after the application of greater than about 2 lbs of force, greater than about 3 lbs of force, greater than about 4 lbs of force, greater than about 5 lbs of force, greater than about 10 lbs of force, greater than about 20 lbs of force, or between about 2 lbs and about 5 lbs of force. The termination device may be configured to detach the locking feature by selecting an appropriate junction between the locking feature and the rest of the termination device (e.g., the thickness, material(s), scoring/perforations, etc.). In some variations, the force applicator used to release the locking feature (e.g., the push rod, fluid line, magnet, etc.) may be configured to apply a controllable force necessary to detach the locking feature. Thus, the force required to separate the locking feature from the rest of the termination device can be adjusted by fusing the materials of the locking feature and the body of the termination device together more or less, by adjusting the amount of perforation, or by changing the adhesive application or friction fit. Further, the amount of force and the way that force is applied to detach the locking feature may be controlled to prevent damage to the locking feature, the tether, the anchors, and/or the surrounding tissue. The locking feature may also be released by cutting the joint between it and the rest of the termination catheter (e.g., by a shearing blade that slides to shear the fuse joint). A cutter may also cut the cable and the joint in a combined manner, thus completely releasing the locking mechanism with the cable severed.
• Although we have described only a few of the ways that a locking feature may be detachably connected to a termination device, it should be understood that any appropriate attachment may be used, including snap fits and attachment mechanisms (e.g., threads, etc.). The attachments described herein may be readily scaled in size for use with even applications requiring very small locking features (e.g., during percutaneous applications).
• In operation (e.g., during an annuloplasty procedure), a locking feature is typically secured to the tether to fix its length (in some cases cinching the tether), such that the end of the tether does not slide through the eye of the most proximal anchor, as described above. After the tether is locked, the excess length of tether may be cut and removed.
• Typically, cinching occurs by applying tension to the tether while bracing the termination device (e.g., including a locking feature) against the most proximal anchor. The tether may slide through the termination device when the locking feature is not in a secured state. After the desired amount of cinching is achieved, the locking feature is engaged, locking the suture in place. For example, the termination device shown inFIG. 39 can be used to secure a tether (e.g., cinching an annulus) by applying force from a push rod to push theplug3913 into the locking feature and secure the tether. The end of the locking feature shown inFIG. 39 comprises an outer tube that is partially or completely closed (narrowed) so as the plug is pushed in, it is held securely against the tether. As described above, the plug may comprise a material which is compressible or elastic to aid in locking the plug into the end of the locking feature. In some variations, a portion of the locking feature may be configured to secure the locking feature in the locked position, and/or to secure the tether. For example, theplug3913 shown as part of the locking feature inFIGS. 39 and 40 may have polygonal (e.g., hexagonal) sides that interact with the inner surface of the locking mechanism. The plug maybe solid or hollow. The plug may have bumps, dimples, ribs, grooves or holes on the surface to increase traction on the cable. The locking feature may also include structures (e.g., rims, brackets, etc.) to help hold the plug in the locked configuration. Thus, this locking feature (like most of the locking features described above) has an unsecured state, in which the tether may move with respect to the locking feature, and a secured state, in which the tether is secured or held by the locking feature. Once the tether is locked into position, the push-rod can be further advanced to separate the locking feature from the rest of the termination device. The outer tube may also be polygonal in cross-section.
• As described above, any appropriate locking feature may be used. For example, the locking feature may comprise a kinking tube that is kinked to secure a tether by a plug. In one variation, the tether passes inside of an outer tube of the locking feature through a pre-kinked smaller tube. When passing and cinching the tether, the tether is tensioned, causing the pre-kinked inner tube to straighten and thus lower the sliding force required to move the tether in the termination device. When it is desired to secure the locking feature, a plug can be pushed into the outer tube to buckle and kink the pre-kinked inner tube to secure the tether in very tight windings, locking the tether in position.FIGS. 42A and 42B show one variation of a termination device having a locking feature that fixes a tether in a tight winding path within the locking feature to secure the tether. InFIG. 42A, the locking feature is shown in the unlocked state, when theinner tube4207 is un-kinked, allowing thetether3910 to pass freely though the locking feature (e.g., the outer tube4210).FIG. 42B shows the locking feature in the secured state, in which the inner (kinking) tube has been kinked so that thetether3910 is constrained, and cannot slide freely within theinner tube4207. InFIG. 42B, aplug4201 is pushed forward into the distal end of the locking feature, compressing the kinkinginner tube4207 and securing thetether3910 into the locked position.
• The tether may be cut to remove excess material (e.g., proximal to the locking feature) either before or after detaching the locking feature from the rest of the termination device. As previously described, the termination deice (including the detachable locking feature) may be combined with any of the tether cutters described herein.FIGS. 40A and 40B illustrate different tether cutters that may be incorporated into a termination device, including the detachable locking feature.FIG. 40A shows a termination device with a detachable locking feature similar to the one shown inFIG. 39. The termination device also includes a tether cutter that is configured as acutting tube4002 that has a sharpenedouter edge4004. Thepush rood3915 passes through the cutting tube. The termination device also includes guides which guide thetether3910 through the termination device so that it can be positioned for cutting by the cuttingtube4002. InFIG. 40A, the tether is positioned through the termination device so that it can be readily cut by the cutting tube when the tube is brought forward (e.g., moving the cutting tube distally). InFIG. 40A, the cutting tube has at least one edge (e.g., over half of the cutting tube circumference) so that at least one end of the tether (e.g., the end contacting the more proximal end of the tether) is cut by the cutting tube. As described above, other types of tether cutters may be used as well. For example,FIG. 40B shows a similar tether cutter that is configured to cut the tether when thecutting tube4010 is drawn proximally. InFIG. 40B, the cutting tube has apassage4012 through which thetether3910 passes, and at least a portion of the cutting tube is sharp4014. Thetether3910 also passes through the wall of the termination device (configured as a catheter inFIGS. 40A and 40B). The end of the tether can be cut by drawing the tether taught after securing the locking feature of the termination device and then moving the cutting tube against the tether so that it is cut.
• The exemplary termination devices shown inFIGS. 39 and 40 include passages or holes through which the tether may couple with thetether3910. As described above, the tether may be threaded into the passages of the termination device either during use, or before inserting the termination device. The locking device portion of a termination device may include a first passage for engaging the tether on the side (e.g., a more distal side, as shown inFIG. 42A and 42B) of the locking device, rather than at the distal end, as shown inFIGS. 39-41. In variations of the locking feature where the side is longer than width, and the tether enters the locking feature from the side, the locking feature may be held against the tissue on the longer side of the locking feature. Thus, the location where the tether first engages the locking feature may determine how the locking feature is positioned after being secured to a cinched tether.
• In some variations, a threading device (e.g., a lasso) may be included to draw the thread through the termination device, as described above forFIG. 14A and 14B.FIG. 41A shows another variation of athreading device4104, preloaded into thetermination device4101. The threading device shown comprises a wire that forms a loop (e.g., a lasso), and the flattened loop passes through the holes (or passages) in the termination device. The tether may be passed through the loop, and drawn into the termination device, as previously described.
• In some variations, the termination device may include channels, guides or passages which direct the tether. For example,FIG. 41B shows a portion of a termination device having adetachable locking feature4107. The termination device includes passages and guides which position the tether within the termination device when the tether is coupled to the termination device. Thus, the tether may be held so that it can be secured, and then cut, using the termination device.FIG. 41C shows an example of a detachable locking feature of a termination device as described fromFIGS. 39-40 in which the locking feature has be secured to the tether and released from the rest of the termination device.
• AlthoughFIGS. 39-41 illustrate termination devices having detachable locking features configured as clamps, any appropriate locking feature (e.g., knot, collars, adhesives, clamps, etc.) may be used, as described above.
• Furthermore, although the foregoing has been described in some detail by way of illustration and example for purposes of clarity of understanding, it is apparent to those skilled in the art that certain minor changes and modifications will be practiced. Therefore, the description and examples should be construed as limiting the scope of the invention as described in the claims.

Claims (21)

1. A termination device for locking an implantable and cinchable tether, the termination device comprising:

an elongate body; and

a locking feature releasably attached to the distal end of the elongate body, the locking feature configured to couple to the tether; the locking feature having an unsecured state, wherein the tether may move with respect to the locking feature, and a secured state, wherein the tether is secured by the locking feature.

2. The termination device ofclaim 1, further comprising a tether cutter.

3. The termination device ofclaim 2, wherein the tether cutter is located distally to the locking feature.

4. The termination device ofclaim 2, wherein the tether cutter comprises a cutting tube within the elongate body.

5. The termination device ofclaim 1, wherein the elongate body is configured as a catheter.

6. The termination device ofclaim 1, further comprising a force applicator for releasing the locking feature from the rest of the termination device.

7. The termination device ofclaim 6, wherein the force applicator comprises a push rod extending longitudinally within the elongate body of the termination device.

8. The termination device ofclaim 1, further comprising a releasable attachment region between the locking feature and the elongate body.

9. The termination device ofclaim 8, wherein the releasable attachment region comprises a frangible region.

10. The termination device ofclaim 1, further configured to separate the locking feature from the elongate body when a force of greater than about2 lbs is applied to the locking feature.

11. The termination device ofclaim 8, wherein the releasable attachment region comprises a perforated region.

12. The termination device ofclaim 1, wherein the locking feature comprises a different material than the elongate body.

13. The termination device ofclaim 1, wherein the locking feature comprises a clamp.

14. The termination device ofclaim 1, wherein the locking feature comprises a plug configured compress the tether against a wall of the locking feature in the secured state.

15. The termination device ofclaim 1, wherein the locking feature comprises a plug configured to fix the tether in a tight winding path within the locking feature in the secured state.

16. A termination device comprising:

an elongate body;

a locking feature releasably attached to the distal end of the elongate body, the locking feature configured to couple to the tether; and

a tether cutter coupled to the elongate body, wherein the tether cutter may be activated to cut the tether.

17. A method of securing a cinchable tether comprising:

coupling the tether to a termination device, wherein the termination device comprises:

an elongate body; and

a locking feature releasably attached to the distal end of the elongate body, the locking feature configured to couple to the tether;

cinching the tether; and

securing the tether with the locking feature.

18. The method ofclaim 17, further comprising cutting the tether.

19. The method ofclaim 17, further comprising separating the locking feature from the elongate body.

20. The method ofclaim 19, wherein the step of separating the locking feature from the elongate body comprises: applying force to separate the locking feature from the elongate body.

21. The method ofclaim 20, wherein the step of applying force comprises pushing a push rod located at least partly within the elongate body.

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