Heart valve repair removal method and device

Abstract

A retrieval catheter and method of use for removing a heart valve treatment, such as a leaflet clip or prosthetic leaflet chordae, is described. The retrieval catheter can include a cutting element and a basket, a piercing element, a clamping mechanism, or a similar grasping device. The method includes delivering a catheter to the area of ​​the heart valve treatment, then manipulating the catheter and associated tools as necessary to resect tissue, then removing the heart valve treatment, and withdrawing the catheter.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of and priority to U.S. Provisional Application No. 63 / 266799, filed January 14, 2022, entitled "Method and Device for Removing Chord and Tissue Surrounding Leaflet Apposition Therapy," U.S. Provisional Application No. 63 / 362507, filed April 5, 2022, entitled "Heart Valve Therapy Clip Removal," and U.S. Provisional Application No. 63 / 368588, filed July 15, 2022, entitled "Electrosurgical Devices and Methods," the entire contents of which are incorporated herein by reference. [Background technology]

[0002] Heart valve disease can occur when a patient's valve leaflets fail to close completely, allowing blood to flow backward or abnormally backward. With reference to FIG. 1, regurgitation is particularly common in the mitral valve 20, where the anterior leaflet 22 of the mitral valve fails to join properly with the posterior leaflet 24. When the ventricles of the heart 10 contract, some blood flows back from the left ventricle 14 into the left atrium 12 instead of the aorta 11. Similar regurgitation can also occur in the tricuspid valve 15, where blood can flow back from the right ventricle 13 into the right atrium 16.

[0003] A common treatment for valvular regurgitation is the use of a therapeutic device that overlaps or permanently connects the leaflets. This heart valve therapeutic hardware may have been placed using surgical, transcatheter, or minimally invasive means. For example, the hardware or treatment targeted for removal may be the MitraClip (Abbott Structural, Santa Clara, CA, USA), the PASCAL device (Edwards Lifesciences, Irvine, CA, USA), a surgically placed suture (e.g., Alfieri suture), or a similar heart valve treatment. Other heart valve treatments may be the result of techniques involving the leaflets as part of the treatment target, with partial or total leaflet involvement necessitating resection. Other examples include chordae replacement techniques placed using either transcatheter or surgical techniques to compensate for inadequate length, disruption, or misalignment of existing chordae. For purposes of this specification, the phrase "heart valve therapy" or "heart valve therapy device" is defined as any device and / or method used in the therapeutic treatment of a heart valve, such as a leaflet clip, suture, artificial chordae, or other device or method related to the treatment of a heart valve and its associated leaflets.

[0004] FIG. 2 illustrates an exemplary transcatheter delivery procedure for a valve clip 40 (e.g., MitraClip) for treating a regurgitating mitral valve 20. A delivery catheter 41 is advanced through the right atrium 16, through the atrial septum 18, and into the left atrium 12. As best shown in FIG. 3, an inner portion of a catheter 41A containing the valve clip 40 is advanced through the mitral valve 20 and into the left ventricle 14. In this example, the leaflet clip 40 includes two outer arms 40A positioned below the leaflets 22, 24 and two inner arms 40B positioned perpendicularly between the two leaflets 22, 24. As shown in FIG. 3, the catheter 41 includes a control wire that can close the outer arms 40A relative to the inner arms 40B to pinch or engage the tissue of the leaflets. As shown in FIG. 4, barbs or similar structures on the arms 40B help the leaflet clip 40 to anchor within the tissue of the leaflets 22, 24. Finally, the catheter 41 is removed, as shown in FIG. 5. 6, leaflet clip 40 is typically placed near the center of valve 20 to prevent the center from opening and creates two smaller valve openings on either side of clip 40. The smaller diameter of these openings typically provides better leaflet cohesion and prevents regurgitation.

[0005] In some cases, these structures may need to be removed to facilitate other valve therapies, such as when there is recurrent or persistent regurgitation that requires treatment. For example, the valve may require annuloplasty or placement of rings, chordae or cords, positioning devices, or leaflets, many of which may not be available with the previously performed heart valve therapy.

[0006] In some cases, these treatments need to be removed from one or more attachment points on the valve leaflets, but do not need to be completely removed to facilitate other valve treatments, leaving the structure in the heart but displacing it from the area of ​​interest so the desired treatment can be applied.

[0007] However, these heart valve repairs are typically removed through open-heart surgery, which is particularly traumatic for the patient and carries a relatively high risk of complications. Therefore, what is needed is a less traumatic technique for removing heart valve repairs that reduces the risk of complications. Summary of the Invention

[0008] The present disclosure relates to systems and methods for removing a heart valve treatment that has been used to position the valve leaflets, which may be necessary when further treatment is needed to treat disease of the valve (e.g., a different repair method, valve replacement), when the heart valve treatment has harmed or may harm the patient (e.g., stenosis, infection), when the heart valve treatment is not considered clinically beneficial, or when there is a general desire not to perform the treatment.

[0009] The present disclosure relates to systems and methods for removing heart valve therapies used to position valve leaflets, which may have been placed using surgical, transcatheter, or minimally invasive means. In at least one embodiment, the hardware or therapy targeted for removal may be a MitraClip (Abbott Structural, Santa Clara, CA), a PASCAL device (Edwards Lifesciences, Irvine, CA), a surgically placed suture (e.g., Alfieri suture), or similar positioning devices and techniques. In at least one embodiment, such positioning devices that need to be removed may be the result of techniques involving leaflets as part of the treatment target, with involvement of a portion or the entire leaflet necessitating removal. Examples of such devices include chordae replacement techniques placed using either transcatheter or surgical techniques. In some cases, chordae or cords are not effective due to improper length, splitting, misalignment, or defects in the artificial material.

[0010] The method of the present invention includes a tool for ablating native valve tissue attached to the heart valve repair with or without a capture tool, which holds the hardware to be removed while it is exposed from the body. In at least one embodiment, the ablation method consists of an adjustable snare that covers the heart valve repair and mechanically ablates the native tissue from the heart valve repair or by using an RF electrosurgical device that heats the tissue such that the intracellular temperature of the electrosurgical ablation device rapidly reaches 100°C, the intracellular contents are converted from liquid to gas, undergoing a massive volume expansion and resulting in evaporation. In at least one embodiment, the capture tool is an adjustable basket, bag, or bottle. The capture tool can be used to ablate, release, compress, modify, or completely withdraw the heart valve repair from the body.

[0011] In some embodiments, the method for removing a previously placed heart valve repair comprises a steerable catheter inserted into the patient using a transseptal, transatrial, or transventricular approach, including a delivery catheter that allows for the placement of tools to ablate and capture the heart valve repair.

[0012] In some embodiments, capture of the heart valve treatment is accomplished by insertion and implantation of a tool directly into, on, and / or around the heart valve treatment. In this approach, native tissue is ablated from the heart valve treatment by using an electrosurgical ablation device (RF electric or similar device) or similar energy or force delivered from within the implanted tool. A basket or bag for capturing the heart valve treatment may not be necessary for removal of the targeted material. Thus, in at least one embodiment, the ablation tool is used alone, without the need for a capture basket.

[0013] In at least one embodiment, the loop structure is pressed over the fixation method created by the tissue bridge, chordae tendineae implant, or heart valve repair. The loop structure can be used for resection either by electrical current or mechanical means. The loop structure can be circular, elliptical, or multi-segmented in shape and can completely or incompletely enclose an area for resection and removal. The loop structure can be used to encircle the heart valve repair and tissue and then expose it for removal.

[0014] In at least one embodiment, the tool is used to expand the heart valve repair for removal, which can be by mechanical, electrical, pneumatic, hydraulic, or similar means to deploy or change the shape of the heart valve repair for its removal.

[0015] The tool elements can be anchored to the heart valve procedure to reduce the risk of embolism. This anchoring can be achieved by anchors that are straight, helical, barbed, or a combination of these techniques.

[0016] In at least one embodiment, a catheter, spacer, balloon, or other device can be used in combination with the removal device to manage blood flow or reflux after valve removal of the heart valve repair. This can be done quickly if the removed heart valve repair and basket can be retracted through the steerable catheter, and the sealing device can then be delivered through the same delivery catheter.

[0017] Further embodiments of the present invention relate to a removal system for a valve clip or similar heart valve treatment, which may include a resection and capture catheter and a snare catheter deployable from the same or separate delivery catheters. The snare catheter can be used to first grasp and pull the valve clip distally (e.g., further into the left ventricle) to create tension or force on the valve leaflets. The resection loop and basket of the resection and capture catheter can then be positioned over the valve clip such that the resection loop is positioned proximal or atrial to the heart valve treatment. Finally, the resection loop can be activated to resect the heart valve treatment device, and finally the clip can be captured in the basket and removed from the patient. This design allows the resection loop to be pulled through tissue and the capture basket to close around the heart valve treatment device while simultaneously resecting and capturing the heart valve treatment.

[0018] The snare catheter may include a snare loop having a circular shape or an elliptical saddle shape that forms an arc shape along each side. The snare loop may have multiple teeth, a friction coating, or may be composed of a coiled wire. The snare catheter may include a distal tip with an opening in its sidewall and features that create friction with the captured valve clip, such as sharp edges, ridges, grooves, or hooks.

[0019] The snare catheter may include a handle configured to store the snare loop within the snare catheter. The handle may include a mechanism for maintaining tension on the clip and a mechanism for limiting the force a user exerts on the tightened snare. The handle may include a locking mechanism for locking the snare in a desired stored position.

[0020] The removal system may also include a guidewire passageway through one or both of the resection and capture catheter and the snare catheter. In an embodiment, the guidewire passageway may extend through the baskets of the snare catheter and the resection and capture catheter. The guidewire may extend longitudinally across the capture basket or within the tip and along the exterior surface of the basket.

[0021] The removal system may include a chordae dilator configured to at least partially occlude the distal opening of the delivery catheter and provide a relatively smooth transition with fewer sharp surfaces for the chordae or other features of the valve to "hang on."

[0022] The ablation and capture catheter may include an expandable capture basket that expands from a longitudinally compressed configuration to a longitudinally expanded configuration as the valve clip is retrieved.

[0023] The removal system may also include a catheter configured to press against the valve clip from the atrial side of the valve to provide a counterforce. Thus, the resection loop of the resection / capture catheter may be better positioned between the atrial side of the valve clip and the valve leaflets. The catheter may be configured for contact only or may be configured to evenly engage or attach to the valve clip.

[0024] The removal system may include a snare catheter that includes a cutting element capable of engaging the tissue surrounding the valve clip or other heart valve treatment to facilitate capture and removal.

[0025] In some aspects, the technology described herein relates to a snare catheter for a medical procedure on a patient, comprising: an elongate sheath having a lumen and one or more openings at a distal portion thereof leading to the lumen; an internal control member extending within the elongate sheath; a snare loop disposed at a distal end of the internal control member and extending outwardly from the one or more openings; and an electrical insulator configured to reduce transmission of electrical current between electrical ablation devices within the patient's heart.

[0026] In some aspects, the technology described herein relates to a snare catheter, wherein the electrical insulator is disposed over a portion or the entirety of the snare loop.

[0027] In some aspects, the technology described herein relates to a snare catheter, wherein the electrical insulator comprises a coating layer or a tube comprising silicone, polyolefin, polyimide, a dielectric material, PTFE, FEP.

[0028] In some aspects, the technology described herein relates to a snare catheter, wherein the snare loop comprises one or more wires comprising nitinol or stainless steel.

[0029] In some aspects, the technology described herein relates to a snare catheter, wherein the elongate sheath further includes a distal end member located at a distal end of the elongate sheath forming the one or more openings, and the electrical insulator further includes a layer, coating, or structural material.

[0030] In some aspects, the technology described herein relates to a snare catheter, wherein the distal end member has a rounded, curved, or blunt shape around the one or more openings to reduce or limit damage to the electrical insulator.

[0031] In some aspects, the technology described herein relates to a snare catheter, wherein the rounded, curved, or blunt shape is formed by an insert connected to the distal end member or by the distal end member.

[0032] In some aspects, the technology described herein relates to a snare catheter, wherein the one or more openings are located on a side of the distal end member relative to the axis of the elongate sheath.

[0033] In some aspects, the technology described herein relates to a snare catheter for a medical procedure on a patient, comprising: an elongate sheath having a lumen; an internal control member extending within the elongate sheath; a snare loop disposed at a distal end of the internal control member; and a distal end member connected to the distal end of the elongate sheath and having a first opening and a second opening leading to a lumen of the elongate sheath, the snare loop being positioned through the first opening and the second opening such that structural features of the first opening and the second opening prevent the snare loop from being completely retracted into the lumen of the elongate sheath.

[0034] In some aspects, the technology described herein relates to a snare catheter, wherein the structural feature of the distal end member is a bar or a pin.

[0035] In some aspects, the technology described herein relates to a snare catheter for use in a medical procedure on a patient, comprising an elongate sheath having a lumen and one or more openings at a distal portion thereof leading to the lumen, an internal control member extending within the elongate sheath, and a snare loop disposed at a distal end of the internal control member and extending outwardly from the one or more openings, the snare loop being configured such that when a force is applied to the snare loop in the range of about 0 grams or more and about 3 grams or less, a deflection of a distal end of the snare loop is limited to a range of about 0 mm or more and about 10 mm or less.

[0036] In some aspects, the technology described herein relates to a snare catheter, the snare loop being configured such that when a force in the range of about 0 grams or more and about 2 grams or less is applied to the snare loop, the deflection of the distal end of the snare loop is limited to a range of about 0 mm or more and about 5 mm or less.

[0037] In some embodiments, the technology described herein relates to a snare catheter, wherein the snare loop comprises a solid shape memory wire having a diameter ranging from about 0.001 inches or more to about 0.03 inches or less.

[0038] In some aspects, the technology described herein relates to a tissue ablation catheter for use in a medical treatment of a patient, comprising an elongate catheter body and a resection loop extending from a distal portion of the elongate catheter body, the resection loop comprising one or more shape memory wire segments and one or more electrodes comprising a non-shape memory material.

[0039] In some aspects, the technology described herein relates to tissue ablation catheters with one or more electrodes that comprise stainless steel.

[0040] In some aspects, the technology described herein relates to a tissue ablation catheter, wherein the one or more electrodes include a tube or sleeve connected to the one or more shape memory wire segments.

[0041] In some aspects, the technology described herein relates to a tissue ablation catheter, wherein the one or more electrodes each comprise a non-shape memory wire segment.

[0042] In some aspects, the technology described herein relates to a tissue ablation catheter, wherein the one or more electrodes are radially larger than the one or more shape memory wire segments.

[0043] In some aspects, the technology described herein relates to a tissue ablation catheter, wherein the ablation loop is an open loop or a closed loop.

[0044] In some aspects, the technology described herein relates to a tissue ablation catheter for use in a medical treatment of a patient, comprising an elongate catheter body and a resection loop extending from a distal portion of the elongate catheter body, the resection loop including a main loop segment and one or more electrodes, the one or more electrodes having a larger diameter than the main loop segment.

[0045] In some aspects, the technology described herein relates to tissue ablation catheters, wherein the one or more electrodes have a cylindrical, spherical, cubic, curved and / or ridged shape.

[0046] In some aspects, the technology described herein relates to a tissue ablation catheter, wherein the one or more electrodes are disposed over a portion of a main resection loop segment, the one or more electrodes being disposed above, below, or adjacent an insulating layer of the main resection loop segment.

[0047] In some aspects, the technology described herein relates to a tissue ablation catheter, wherein the one or more electrodes extend entirely or partially around the circumference of the main resection loop segment.

[0048] In some aspects, the technology described herein relates to a tissue ablation catheter, wherein the one or more electrodes are wire segments connected to a segment adjacent to the main resection loop segment.

[0049] In some aspects, the technology described herein relates to a tissue ablation catheter for use in a medical treatment of a patient, comprising an elongate catheter body and further comprising a resection loop extending from a distal portion of the elongate catheter body, the resection loop including one or more main loop segments and an electrode, the electrode including a wire connected to a first location of the resection loop and a second location of the resection loop, forming a space or gap in a portion of the resection loop.

[0050] In some aspects, the technology described herein relates to a tissue ablation catheter for use in a medical treatment of a patient, comprising an elongated catheter body and a resection loop extending from a distal portion of the elongated catheter body, the resection loop including a plurality of electrodes.

[0051] In some aspects, the technology described herein relates to a tissue ablation catheter, wherein the plurality of electrodes includes a first electrode disposed at a central and distal-most position of the resection loop.

[0052] In some aspects, the technology described herein relates to a tissue ablation catheter, wherein the plurality of electrodes includes a second electrode and a third electrode disposed in a distal half of the resection loop and on either side of the first electrode.

[0053] In some aspects, the technology described herein relates to a tissue ablation catheter, wherein the plurality of electrodes includes a first electrode disposed on a first side of the resection loop and a second electrode disposed on a second side of the resection loop.

[0054] In some aspects, the technology described herein relates to a capture basket catheter for a medical procedure on a patient, comprising an elongate catheter body and a capture basket disposed at a distal portion of the elongate catheter body, the capture basket being connected a first distance from a distal end of the elongate catheter body and a second distance from the distal end of the catheter body that is less than the first distance.

[0055] In some aspects, the technology described herein relates to a capture basket catheter, wherein the capture basket is connected to the first catheter by a fastening loop.

[0056] In some aspects, the technology described herein relates to a capture basket catheter, wherein the capture basket is connected at the second distance between a wire of the capture basket and an opening in the elongate catheter body.

[0057] In some aspects, the technology described herein relates to a capture basket catheter, wherein the opening is located at a distal end of the elongate catheter body.

[0058] In some aspects, the technology described herein relates to a catheter delivery device for use in a medical procedure on a patient, comprising an elongated sheath having a sheath lumen extending therethrough, and a sheath hub connected to a proximal end of the elongated sheath, the sheath hub including a plurality of ports opening into a cavity, the cavity narrowing in width distally, the cavity having a funnel at a distal end thereof, the funnel opening into the sheath lumen of the elongated sheath.

[0059] In some aspects, the technology described herein relates to a chordae resection device for use in a medical treatment of a patient, comprising: an elongated catheter body having a catheter lumen, the elongated catheter body having an opening leading from a distal portion of the elongated catheter body to the catheter lumen; a longitudinally movable ablation element disposed within the catheter lumen; and an elongated capture member having a distal end that forms a curved shape when unconstrained, the ablation element being movable by a user to extend from the opening, the ablation element at least partially surrounding one or more chordae within a heart and forming a curved shape configured to draw the chordae into the opening, the ablation element being movable within the catheter lumen distally relative to the chordae to resect the chordae.

[0060] In some aspects, the technology described herein relates to a chordae resection device, wherein the elongate capture member is disposed within a lumen of the resection element.

[0061] In some aspects, the technology described herein relates to a chordae resection device, where the elongated capture member is positioned within the catheter lumen and outside the resection element.

[0062] In some aspects, the technology described herein relates to a chordae resection device, wherein the aperture is disposed through a sidewall of the catheter body.

[0063] In some aspects, the technology described herein relates to a chordae resection device, wherein the curved shape is a loop, a spiral, a helical, a hook, or multiple loops terminating in a hook shape.

[0064] In some aspects, the technology described herein relates to a chordae resection device, wherein the capture member comprises one or more wires having a diameter ranging from about 0.001 inches or more to about 0.030 inches or less.

[0065] In some embodiments, the technology described herein relates to a chordae resection device, wherein the curved shape has a working diameter ranging from about 0.15 inches or more to about 1.5 inches or less.

[0066] In some aspects, the technology described herein relates to a chordae tendineae device, wherein the cutting element has a distal end that forms a bias cutting blade, multiple points, a single point, or a step shape.

[0067] In some aspects, the technology described herein relates to a chordae resection device, wherein the resection element is tubular or solid in shape.

[0068] In some aspects, the technology described herein relates to a chordae tendineae device, wherein the ablation element is an electrode disposed on the capture member and configured to deliver an electrical current for tissue ablation.

[0069] In some aspects, the technology described herein relates to a method for medical treatment of chordae tendineae, comprising advancing an elongate catheter body towards a heart, advancing a distal portion of an elongate capturing member through an opening in the elongate catheter body, allowing the distal portion of the elongate capturing member to bend around one or more chordae tendineae, moving the distal portion of the elongate capturing member and a portion of one or more chordae tendineae within the lumen of the elongate catheter body, and actuating the ablation element within the lumen of the elongate capturing member to sever the one or more chordae tendineae.

[0070] In some aspects, the techniques described herein relate to a method, wherein actuating a cutting element further comprises moving a cutting blade of the cutting element distally relative to one or more chordae.

[0071] In some aspects, the technology described herein relates to a method, where actuating an ablation element includes providing RF power to an electrode of the elongate capture member.

[0072] In some aspects, the technology described herein relates to a method, wherein allowing the distal portion of the elongate capture member to bend around the one or more chordae also includes allowing the distal portion of the elongate capture member to bend around a heart valve clip.

[0073] In some aspects, the technology described herein relates to a method for medical treatment of chordae tendineae, comprising advancing an elongate catheter body towards the heart, advancing a distal portion of an elongate capturing member out of an opening in the elongate catheter body, allowing the distal portion of the elongate capturing member to bend around one or more chordae tendineae and a heart valve clip, moving the distal portion of the elongate capturing member and a portion of one or more chordae tendineae within a lumen of the elongate catheter body, and advancing a separate ablation element into the heart to sever the captured one or more chordae tendineae.

[0074] In some aspects, the technology described herein relates to a method for medical treatment of chordae tendineae, comprising advancing an elongate catheter body towards a heart, advancing a distal portion of an elongate capturing member through an opening in the elongate catheter body, allowing the distal portion of the elongate capturing member to bend around one or more chordae tendineae, and activating electrodes of the elongate capturing member to transect the one or more chordae tendineae.

[0075] In some embodiments, the technology described herein relates to an RF power generator for medical treatment of a patient, comprising an RF power generator housing including a processor, a memory, and software code executable by the processor, and a user interface controllable by the processor and the software code, the software code configured to measure electrical signals of a plurality of electrodes of a resection loop and indicate whether each of the plurality of electrodes is in contact with tissue.

[0076] In some embodiments, the technology described herein relates to an RF power generator for medical treatment of a patient, comprising an RF power generator housing including a processor, a memory, and software code executable by the processor, and a user interface controllable by the processor and the software code, the software code configured to individually enable or disable multiple electrodes on a resection loop.

[0077] In some aspects, the technology described herein relates to a heart valve clip for use in treating a heart valve, comprising a clip body, a leaflet attachment mechanism configured to connect to leaflet tissue, and a snare engagement feature comprising a channel, groove, or enlarged structure at least at a base of the clip body.

[0078] In some aspects, the technology described herein relates to a heart valve clip for use in treating a heart valve, comprising a clip body, a leaflet engagement mechanism configured to engage leaflet tissue, and an electrode configured to deliver an electrical current when the electrical current is supplied to the clip body.

[0079] In some embodiments, the technology described herein relates to a tissue ablation catheter for use in a medical treatment of a patient, comprising an elongate catheter body and a resection loop extending from a distal portion of the elongate catheter body and including one or more electrodes, each of the one or more electrodes having a surface area within a range of about 0.003 square inches or more and about 0.006 square inches or less.

[0080] In some aspects, the technology described herein relates to a tissue ablation catheter, wherein the one or more electrodes each have a surface area of ​​about 0.00437506 square inches.

[0081] In some aspects, the technology described herein relates to a tissue ablation catheter, wherein the one or more electrodes are connected to a power source configured to provide RF power in the range of about 5 Watts or more and about 1600 Watts or less.

[0082] While multiple embodiments are disclosed, still other embodiments of the present disclosure will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the invention. As will be understood, the various embodiments of the present disclosure can be modified in various obvious aspects, all without departing from the spirit and scope of the present disclosure. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive. [Brief description of the drawings]

[0083] These and other aspects, features and advantages of possible embodiments of the present invention will be apparent or obvious from the following description of the embodiments of the invention.

[0084] [Figure 1] FIG. 1 is a diagram illustrating the anatomical structure of the heart.

[0085] [Diagram 2] FIG. 2 is a side view of a procedure for implanting a leaflet heart valve treatment device.

[0086] [Diagram 3] FIG. 3 is a side view of a procedure for implanting a leaflet heart valve treatment device.

[0087] [Figure 4] FIG. 4 is a side view of a procedure for implanting a leaflet heart valve treatment device.

[0088] [Diagram 5] FIG. 5 is a side view of a procedure for implanting a leaflet heart valve treatment device.

[0089] [Figure 6] FIG. 6 is a top view of a procedure for implanting a leaflet heart valve treatment device.

[0090] [Figure 7] FIG. 7 is a side view of a removal catheter according to the present invention.

[0091] [Figure 8] FIG. 8 is a side view of a removal catheter according to the present invention.

[0092] [Figure 9] FIG. 9 is a side view of a removal catheter according to the present invention.

[0093] [Figure 10] FIG. 10 is a side perspective view of a removal catheter according to the present invention.

[0094] [Figure 11] FIG. 11 is a side view of a removal catheter according to the present invention.

[0095] [Figure 12] FIG. 12 is a cross-sectional view of a removal catheter according to the present invention.

[0096] [Figure 13] FIG. 13 is an exploded view of a removal catheter according to the present invention.

[0097] [Figure 14] FIG. 14 is a perspective view of a resection loop in accordance with the present invention.

[0098] [Figure 15] FIG. 15 is a perspective view of a resection loop in accordance with the present invention.

[0099] [Figure 16] FIG. 16 is a perspective view of a resection loop in accordance with the present invention.

[0100] [Figure 17] FIG. 17 is a perspective view of a resection loop in accordance with the present invention.

[0101] [Figure 18] FIG. 18 is a perspective view of a resection loop in accordance with the present invention.

[0102] [Figure 19] FIG. 19 is a perspective view of a resection loop in accordance with the present invention.

[0103] [Figure 20] FIG. 20 is a top view of a resection loop in accordance with the present invention.

[0104] [Figure 21] FIG. 21 is a top view of a resection loop in accordance with the present invention.

[0105] [Figure 22] FIG. 22 is a perspective view of a resection loop in accordance with the present invention.

[0106] [Figure 23] FIG. 23 is a cross-sectional view of a resection loop in accordance with the present invention.

[0107] [Figure 24] FIG. 24 is a cross-sectional view of a resection loop in accordance with the present invention.

[0108] [Diagram 25] FIG. 25 is a cross-sectional view of a resection loop in accordance with the present invention.

[0109] [Figure 26] FIG. 26 is a cross-sectional view of a resection loop in accordance with the present invention.

[0110] [Figure 27] FIG. 27 is a cross-sectional view of a resection loop in accordance with the present invention.

[0111] [Figure 28] FIG. 28 is a cross-sectional view of a resection loop in accordance with the present invention.

[0112] [Figure 29] FIG. 29 is a cross-sectional view of a resection loop in accordance with the present invention.

[0113] [Diagram 30] FIG. 30 is a cross-sectional view of a resection loop in accordance with the present invention.

[0114] [Diagram 31] FIG. 31 is a side view of a basket according to the present invention.

[0115] [Diagram 32] FIG. 32 is a side view of a basket according to the present invention.

[0116] [Diagram 33] FIG. 33 is a side view of a removal catheter according to the present invention.

[0117] [Diagram 34] FIG. 34 is a side perspective view of a removal catheter according to the present invention.

[0118] [Diagram 35] FIG. 35 is a side perspective view of a removal catheter according to the present invention.

[0119] [Diagram 36] FIG. 36 is a side perspective view of a removal catheter according to the present invention.

[0120] [Figure 37] FIG. 37 is a side view of a removal catheter according to the present invention.

[0121] [Figure 38] FIG. 38 is a side view of a removal catheter according to the present invention.

[0122] [Figure 39] FIG. 39 is a side view of a removal catheter according to the present invention.

[0123] [Diagram 40] FIG. 40 is a side view of a basket according to the present invention.

[0124] [Diagram 41] FIG. 41 is a side view of a basket according to the present invention.

[0125] [Diagram 42] FIG. 42 is a side view of a basket according to the present invention.

[0126] [Diagram 43] FIG. 43 is a side view of a basket according to the present invention.

[0127] [Diagram 44] FIG. 44 is a side view of a handle according to the present invention.

[0128] [Diagram 45] FIG. 45 is a side view of a handle according to the present invention.

[0129] [Figure 46] FIG. 46 is a side view of a removal catheter according to the present invention.

[0130] [Figure 47] FIG. 47 is a side view of a removal catheter according to the present invention.

[0131] [Figure 48] FIG. 48 is a side view of a removal catheter according to the present invention.

[0132] [Figure 49] FIG. 49 is a side view of a removal catheter according to the present invention.

[0133] [Figure 50] FIG. 50 is a side view of a removal catheter according to the present invention.

[0134] [Figure 51] FIG. 51 is a side view of a removal catheter according to the present invention.

[0135] [Figure 52] FIG. 52 is a side view of a removal catheter according to the present invention.

[0136] [Figure 53] FIG. 53 is a side view of a removal catheter according to the present invention.

[0137] [Figure 54] FIG. 54 is a side view of a removal catheter and a guide catheter according to the present invention.

[0138] [Figure 55] FIG. 55 is a side view of a removal catheter and a guide catheter according to the present invention.

[0139] [Figure 56] FIG. 56 is a side view of an ablation catheter procedure according to the present invention.

[0140] [Figure 57] FIG. 57 is a side view of an ablation catheter procedure according to the present invention.

[0141] [Figure 58] FIG. 58 is a side view of an ablation catheter procedure according to the present invention.

[0142] [Figure 59] FIG. 59 is a side view of an ablation catheter procedure according to the present invention.

[0143] [Figure 60] FIG. 60 is a side view of an ablation catheter procedure according to the present invention.

[0144] [Figure 61] FIG. 61 is a side view of an ablation catheter procedure according to the present invention.

[0145] [Figure 62] FIG. 62 is a side view of an ablation catheter procedure according to the present invention.

[0146] [Figure 63] FIG. 63 is a side view of an ablation catheter procedure according to the present invention.

[0147] [Figure 64] FIG. 64 is a side view of an ablation catheter procedure according to the present invention.

[0148] [Figure 65] FIG. 65 is a side view of an ablation catheter procedure according to the present invention.

[0149] [Figure 66] FIG. 66 is a side view of an ablation catheter procedure according to the present invention.

[0150] [Figure 67] FIG. 67 is a side view of an ablation catheter procedure according to the present invention.

[0151] [Figure 68] FIG. 68 is a side view of an ablation catheter procedure according to the present invention.

[0152] [Figure 69] FIG. 69 is a side view of an ablation catheter procedure according to the present invention.

[0153] [Figure 70]FIG. 70 is a side view of an ablation catheter procedure according to the present invention.

[0154] [Figure 71] FIG. 71 is a side view of an ablation catheter procedure according to the present invention.

[0155] [Figure 72] FIG. 72 is a side view of an ablation catheter procedure according to the present invention.

[0156] [Figure 73] FIG. 73 is a side view of an ablation catheter procedure according to the present invention.

[0157] [Figure 74] FIG. 74 is a side view of an ablation catheter procedure according to the present invention.

[0158] [Figure 75] FIG. 75 is a side view of an ablation catheter procedure according to the present invention.

[0159] [Figure 76] FIG. 76 is a side view of an ablation catheter procedure according to the present invention.

[0160] [Figure 77] FIG. 77 is a side view of an ablation catheter procedure according to the present invention.

[0161] [Figure 78] FIG. 78 is a side view of an ablation catheter procedure according to the present invention.

[0162] [Figure 79] FIG. 79 is a side view of an ablation catheter procedure according to the present invention.

[0163] [Figure 80] FIG. 80 is a side view of an ablation catheter procedure according to the present invention.

[0164] [Figure 81] FIG. 81 is a side view of an ablation catheter procedure according to the present invention.

[0165] [Figure 82] FIG. 82 is a side view of an ablation catheter procedure according to the present invention.

[0166] [Figure 83] FIG. 83 is a side view of an ablation catheter procedure according to the present invention.

[0167] [Figure 84] FIG. 84 is a side view of an ablation catheter procedure according to the present invention.

[0168] [Figure 85] FIG. 85 is a side view of an ablation catheter procedure according to the present invention.

[0169] [Figure 86] FIG. 86 is a side view of an ablation catheter procedure according to the present invention.

[0170] [Figure 87] FIG. 87 is a side view of an ablation catheter procedure according to the present invention.

[0171] [Figure 88] FIG. 88 is a side view of an ablation catheter procedure according to the present invention.

[0172] [Figure 89] FIG. 89 is a side view of an ablation catheter procedure according to the present invention.

[0173] [Figure 90] FIG. 90 is a side view of an ablation catheter procedure according to the present invention.

[0174] [Figure 91] FIG. 91 is a side view of an ablation catheter procedure according to the present invention.

[0175] [Figure 92] FIG. 92 is a side view of an ablation catheter procedure according to the present invention.

[0176] [Figure 93] FIG. 93 is a side view of an ablation catheter procedure according to the present invention.

[0177] [Figure 94] FIG. 94 is a side view of an ablation catheter procedure according to the present invention.

[0178] [Figure 95] FIG. 95 is a side view of an ablation catheter procedure according to the present invention.

[0179] [Figure 96] FIG. 96 is a side view of an ablation catheter procedure according to the present invention.

[0180] [Figure 97] FIG. 97 is a side view of an ablation catheter procedure according to the present invention.

[0181] [Figure 98] FIG. 98 is a side view of an ablation catheter procedure according to the present invention.

[0182] [Figure 99] FIG. 99 is a side view of an ablation catheter procedure according to the present invention.

[0183] [Figure 100] FIG. 100 is a side view of an ablation catheter procedure according to the present invention.

[0184] [Figure 101] FIG. 101 is a perspective view of a removal catheter device in accordance with the present invention.

[0185] [Figure 102]FIG. 102 is a perspective view of a removal catheter device in accordance with the present invention.

[0186] [Figure 103] FIG. 103 is a perspective view of a removal catheter device in accordance with the present invention.

[0187] [Figure 104] FIG. 104 is a perspective view of a removal catheter device in accordance with the present invention.

[0188] [Figure 105] FIG. 105 is a perspective view of a removal catheter device in accordance with the present invention.

[0189] [Fig. 106] FIG. 106 is a perspective view of a removal catheter device in accordance with the present invention.

[0190] [Figure 107] FIG. 107 is a perspective view of an example of a valve resection.

[0191] [Figure 108] FIG. 108 is a perspective view of a removal catheter device in accordance with the present invention.

[0192] [Figure 109] FIG. 109 is a perspective view of a removal catheter device in accordance with the present invention.

[0193] [Figure 110] FIG. 110 illustrates a snare and removal system according to the present invention. [Figure 111] FIG. 111 illustrates a snare and removal system according to the present invention.

[0194] [Figure 112] FIG. 112 shows a basket tip according to the present invention. [Figure 113] FIG. 113 shows a basket tip according to the present invention.

[0195] [Fig. 114] FIG. 114 shows a snare loop according to the present invention. [Figure 115] FIG. 115 shows a snare loop according to the present invention.

[0196] [Fig. 116] FIG. 116 is a diagram showing a snare loop according to the present invention.

[0197] [Figure 117] FIG. 117 shows a snare loop according to the present invention.

[0198] [Figure 118] FIG. 118 shows a portion of a snare loop according to the present invention.

[0199] [Figure 119] FIG. 119 shows a portion of a snare loop according to the present invention.

[0200] [Figure 120] FIG. 120 shows the tip of a snare catheter according to the present invention. [Figure 121] FIG. 121 is a diagram showing the tip of a snare catheter according to the present invention.

[0201] [Figure 122] FIG. 122 is a diagram showing the tip of a snare catheter according to the present invention.

[0202] [Figure 123] FIG. 123 is a diagram showing the tip of a snare catheter according to the present invention.

[0203] [Figure 124] FIG. 124 is a diagram showing the tip of a snare catheter according to the present invention.

[0204] [Fig. 125] FIG. 125 is a diagram showing a handle for a snare catheter according to the present invention. [Fig. 126] FIG. 126 is a diagram showing a handle for a snare catheter according to the present invention.

[0205] [Figure 127] FIG. 127 illustrates a method for capturing and removing a valve clip according to the present invention. [Figure 128] FIG. 128 illustrates a method for capturing and removing a valve clip according to the present invention. [Figure 129] FIG. 129 illustrates a method for capturing and removing a valve clip according to the present invention. [Fig. 130] FIG. 130 illustrates a method for capturing and removing a valve clip according to the present invention.

[0206] [Fig. 131] FIG. 131 illustrates a removal system configured for access over a guidewire. [Fig. 132] FIG. 132 illustrates a removal system configured for access over a guidewire. [Fig. 133] FIG. 133 illustrates a removal system configured for access over a guidewire.

[0207] [Fig. 134] FIG. 134 shows a chordae spreader according to the present invention. [Fig. 135] FIG. 135 illustrates a chordae spreader according to the present invention. [Fig. 136] FIG. 136 illustrates a chordae spreader according to the present invention. [Fig. 137] FIG. 137 illustrates a chordae tendineae spreader according to the present invention.

[0208] [Fig. 138A] FIG. 138A illustrates a removal system having an alternative guidewire path.

[0209] [Fig. 138B] FIG. 138B illustrates a removal system having an alternative guidewire path.

[0210] [Fig. 139] FIG. 139 illustrates a removal system having a pigtail wire at the distal end of the basket according to the present invention.

[0211] [Fig. 140] FIG. 140 illustrates an extendable basket according to the present invention. [Fig. 141] FIG. 141 illustrates an extendable basket according to the present invention.

[0212] [Fig. 142] FIG. 142 illustrates how force is applied to a valve clip according to the present invention.

[0213] [Fig. 143A] FIG. 143A illustrates an alternative basket configuration of the present invention.

[0214] [Fig. 143B] FIG. 143B illustrates an alternative basket configuration of the present invention.

[0215] [Fig. 144] FIG. 144 illustrates an alternative removal system of the present invention without a basket.

[0216] [Fig. 145] FIG. 145 illustrates an alternative removal system having a cutting element as part of the snare loop according to the present invention.

[0217] [Fig. 146] FIG. 146 illustrates an alternative removal system having a cutting element as part of the snare loop according to the present invention.

[0218] [Fig. 147] FIG. 147 is a side view of a snare loop catheter according to the present invention.

[0219] [Fig. 148] FIG. 148 is a front view of the snare loop catheter according to the present invention shown in FIG. 147.

[0220] [Figure 149] FIG. 149 is a cross-sectional view of the snare loop catheter according to the present invention shown in FIG. 147.

[0221] [Fig. 150] FIG. 150 is a side view of the handle of the snare loop catheter according to the present invention shown in FIG. 147.

[0222] [Fig. 151] FIG. 151 is a diagram showing the distal end of the snare loop catheter according to the present invention shown in FIG.

[0223] [Fig. 152] FIG. 152 is a diagram showing the distal end of the snare loop catheter according to the present invention shown in FIG.

[0224] [Fig. 153] FIG. 153 shows the distal end of a snare loop catheter according to the present invention.

[0225] [Fig. 154] FIG. 154 shows the distal end of a snare loop catheter according to the present invention.

[0226] [Fig. 155] FIG. 155 illustrates a snare loop and inner control member according to the present invention.

[0227] [Fig. 156] FIG. 156 is a front view of a resecting loop catheter according to the present invention.

[0228] [Fig. 157] FIG. 157 is a side view of the resecting loop catheter according to the present invention shown in FIG.

[0229] [Fig. 158] FIG. 158 is a front view of a resecting loop catheter according to the present invention.

[0230] [Fig. 159] FIG. 159 is a side view of the resecting loop catheter according to the present invention shown in FIG.

[0231] [Fig. 160] FIG. 160 is a cross-sectional view of an electrode according to the present invention.

[0232] [Fig. 161] FIG. 161 is a cross-sectional view of an electrode according to the present invention.

[0233] [Fig. 162] FIG. 162 is a cross-sectional view of an electrode according to the present invention.

[0234] [Fig. 163] FIG. 163 is a cross-sectional view of an electrode according to the present invention.

[0235] [Fig. 164] FIG. 164 is a cross-sectional view of an electrode according to the present invention.

[0236] [Fig. 165] FIG. 165 is a cross-sectional view of an electrode according to the present invention.

[0237] [Fig. 166] FIG. 166 is a perspective view of an electrode according to the present invention.

[0238] [Fig. 167] FIG. 167 is a front view of an electrode of a resection loop according to the present invention.

[0239] [Fig. 168] FIG. 168 is a side view of a resection loop with multiple electrodes in accordance with the present invention.

[0240] [Fig. 169] 169 is a side view of the resection loop according to the present invention shown in FIG.

[0241] [Fig. 170] FIG. 170 is a top view of the resection loop according to the present invention shown in FIG.

[0242] [Fig. 171] FIG. 171 is a top view of a resection loop with multiple electrodes in accordance with the present invention.

[0243] [Fig. 172] FIG. 172 is a side view of an open or hook shaped resection loop according to the present invention.

[0244] [Fig. 173] FIG. 173 is a side view of a capture basket catheter according to the present invention.

[0245] [Fig. 174] FIG. 174 illustrates the distal end of the capture basket catheter according to the present invention shown in FIG.

[0246] [Fig. 175] FIG. 175 illustrates the distal end of the capture basket catheter according to the present invention shown in FIG.

[0247] [Fig. 176] FIG. 176 is a side view of a catheter hub according to the present invention.

[0248] [Fig. 177] FIG. 177 is a cross-sectional view of the catheter hub according to the present invention shown in FIG.

[0249] [Fig. 178] FIG. 178 shows a loading tool according to the present invention.

[0250] [Fig. 179] FIG. 197 shows the catheter hub of the present invention shown in FIG.

[0251] [Fig. 180] FIG. 180 illustrates a heart valve repair removal system according to the present invention.

[0252] [Fig. 181] FIG. 181 is a side view of a chordae tool according to the present invention.

[0253] [Fig. 182] FIG. 182 is a side view of a chordae tool according to the present invention.

[0254] [Fig. 183] FIG. 183 is a side view of a chordae tool according to the present invention.

[0255] [Fig. 184] FIG. 184 is a side view of a chordae tool according to the present invention.

[0256] [Fig. 185] FIG. 185 is a side view of a chordae tool according to the present invention.

[0257] [Fig. 186] FIG. 186 is a side view of a chordae tool according to the present invention.

[0258] [Fig. 187] FIG. 187 is a side view of a cutting element for a chordae tool according to the present invention.

[0259] [Fig. 188]FIG. 188 is a side view of a cutting element for a chordae tool according to the present invention.

[0260] [Fig. 189] FIG. 189 is a side view of a cutting element for a chordae tool according to the present invention.

[0261] [Fig. 190] FIG. 190 is a side view of a cutting element for a chordae tool according to the present invention.

[0262] [Fig. 191] FIG. 191 illustrates a method of using a chordae tool according to the present invention.

[0263] [Fig. 192] FIG. 192 illustrates a method of using a chordae tool according to the present invention.

[0264] [Fig. 193] FIG. 193 illustrates a method of using a chordae tool according to the present invention.

[0265] [Fig. 194] FIG. 194 illustrates a method of using a chordae tool according to the present invention.

[0266] [Fig. 195] FIG. 195 illustrates a method of using a chordae tool according to the present invention.

[0267] [Fig. 196] FIG. 196 illustrates a method of using a chordae tool according to the present invention.

[0268] [Figure 197] FIG. 197 illustrates a method of using a chordae tool according to the present invention.

[0269] [Figure 198] FIG. 198 illustrates a method of using the chordae tool according to the present invention.

[0270] [Figure 199] FIG. 199 illustrates a method of using a chordae tool according to the present invention.

[0271] [Figure 200] FIG. 200 illustrates a method of using a chordae tool according to the present invention.

[0272] [Figure 201] FIG. 201 is a diagram showing the power supply and interface according to the present invention.

[0273] [Figure 202] FIG. 202 is a diagram showing the power supply and interface according to the present invention.

[0274] [Fig. 203] FIG. 203 illustrates a heart valve clip according to the present invention.

[0275] [Fig. 204] FIG. 204 illustrates a heart valve clip according to the present invention.

[0276] [Fig. 205] FIG. 205 illustrates a heart valve clip according to the present invention.

[0277] [Fig. 206] FIG. 206 illustrates a heart valve clip according to the present invention.

[0278] [Fig. 207] FIG. 207 illustrates a heart valve clip according to the present invention.

[0279] [Fig. 208] FIG. 208 illustrates a heart valve clip according to the present invention. Detailed Description

[0280] Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings. However, the present invention may be implemented in many different forms and should not be construed as being limited to the embodiments described herein. Rather, these exemplary embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present invention to those skilled in the art. The terms used in the detailed description of the embodiments shown in the accompanying drawings are not intended to limit the present invention. In the drawings, like numbers refer to like elements.

[0281] The present invention relates generally to devices and methods for removing heart valve treatment devices via transcatheter procedures. While current methods for the removal of heart valve treatment devices require open heart surgery, the techniques and devices of the present invention utilize transcatheter devices and methods that are less invasive and may provide better patient outcomes.

[0282] For purposes of this application, the phrase "heart valve therapy" is defined as any device and / or method used in the therapeutic treatment of a heart valve, such as a leaflet clip, suture, artificial chordae, or other device or method related to the treatment of a heart valve and associated leaflets. Although in certain embodiments, a particular heart valve therapy device or method may be discussed or illustrated, such as a leaflet clip, it is understood that use with any heart valve therapy is specifically contemplated. Thus, none of the embodiments discussed herein should be limited to use only with leaflet clips.

[0283] 1-13 show various aspects of one embodiment of a removal catheter 100 for removing a leaflet heart valve treatment device, such as a valve clip 40 or similar heart valve treatment device according to the present invention. The removal catheter 100 generally includes an expandable capture basket 102 and a cutting element or resection loop 104 disposed near the top opening of the basket 102. As shown in FIGS. 7 and 8, the basket 102 is placed over the implanted valve clip 40, with the top of the basket 102 and the resection loop 104 disposed between the clip 40 and the leaflets 22, 24 of the atrial valve leaflets 22, 24. The top opening of the basket 102 is then closed or contracted, and the resection loop 104 is actuated to resect the leaflet tissue surrounding the valve clip 40 (e.g., by delivery of radio frequency energy), and release the clip 40 from the valve 20. Finally, the capture basket 102 including the valve clip 40 is pulled back and removed from the patient. Further details and variations of the removal catheter 100 are described below, followed by exemplary procedures and removal methods for various heart valves (eg, the mitral valve 20 or the tricuspid valve 15).

[0284] As best shown in Figures 9-11, the removal catheter 100 includes an inner control member 108 (best shown in Figure 11) disposed within an outer tubular sheath 110. The inner control member 108 can be a solid wire or tube that extends between distal and proximal ends of the sheath 110. The basket 102 and resection loop 104 are connected to the distal end of the inner control member 108 such that when the inner control member 108 moves longitudinally or rotationally relative to the outer tubular sheath 110, the basket 102 and resection loop 104 move similarly.

[0285] 11, in one embodiment, multiple loops 102A are placed around the circumference of the top opening of the basket 102, and a wire or fastening loop 106 is placed through the loops 102A. As best shown in FIG. 13, the fastening loop 106 can be comprised of a looped wire (e.g., circular, oval, etc.) and an elongated straight section 106A that can be connected to the control member 108 via a connecting sleeve 112. The connecting sleeve 112 can be clamped, welded, glue / epoxy, or any combination thereof, to secure the sleeve 112 to the control member 108. Alternatively, the fastening loop 106 can be connected to the control member 108 only via welding or glue.

[0286] Resection loop 104 may likewise be formed into a general loop shape (e.g., circular, oval, saddle-shaped, etc.) and may include an elongated straight portion 104E which may also be connected to control member 108 via a connecting sleeve 112. In this regard, both elongated straight portions 106A and 104E are disposed within connecting sleeve 112, as shown in cross-sectional view in FIG.

[0287] In one embodiment, the resection loop 104 ablates tissue when radio frequency energy is delivered to the resection loop. In one example, an RF power source is connected to the proximal end of the control member 108, which is made of a conductive metal, so as to transmit the RF energy to its distal end and then to the attached resection loop 104. To complete the RF energy circuit with the resection loop 104, a second RF electrode can be connected to the RF power source and attached to the patient elsewhere via an electrode pad (monopolar RF system), a second electrode can be included elsewhere on the ablation catheter 100 (bipolar RF system), or a second insulated wire can be included on the control member 108 (bipolar RF system). Radio frequency energy is an established technical term to describe high frequency alternating current (having a frequency of about 300 kHz to 3 MHz, more narrowly 100 kHz to 10 MHz).

[0288] It may be desirable to isolate the RF energy circuitry of the resection loop 104 from both the fastening loop 106 and the basket 102 to prevent damage to other tissues in the heart. This can be accomplished by using electrical insulation as specific locations on the device. For example, as shown in the cross-sectional view of FIG. 12 and the exploded view of FIG. 13, electrical wire insulation 114 can be placed on the elongated straight portion 106A (or throughout the fastening loop 106, if desired) to electrically isolate the fastening loop 106 from the RF current of the control member 108.

[0289] In other examples seen in Figures 14-30, the resection loop 104 can have different structures, shapes, and electrical insulation to help reduce the risk of the non-insulated portion 104B (i.e., the portion that resects the leaflet tissue) coming into contact with the clamping wire 106 or any portion of the basket 102. For example, Figure 14 shows a resection loop 104 where the non-insulated portion 104B of the wire is located opposite an elongated straight portion 104E and adjacent an insulated portion 104A on each side. In this example, the non-insulated portion 104B can extend around the entire circumference of the wire, as shown in Figure 21, or can be exposed only along the inside of the loop 104, as shown in Figure 20.

[0290] The non-insulated portion 104B can include only a single area (e.g., about 1-5 mm) where the underlying wire 104C is exposed, as shown in FIG. 14, or can include multiple separate non-insulated portions 104B (e.g., 2-10 portions 104B) of relatively short length (e.g., about 1-5 mm) as shown in FIG. 22.

[0291] In all resection loop embodiments, the majority of the surface of the resection loop 104 is insulated. To form the non-insulated portion 104B, the resection loop insulation 104A can be selectively removed (in the case of a wire with existing insulation) to expose the resection loop conductive wire 104C for contacting and delivering RF ablation energy to the leaflet tissue bridge when in contact with tissue adjacent the heart valve treatment. Alternatively, insulation 104A can be added (e.g., by dipping, spraying, or similar techniques) and non-insulated portion 104B can be created by masking the intended area before applying the insulation.

[0292] It will be appreciated that the non-insulated portion 104B can be oriented in any number of ways, for example, on the inner / outer surface of the resection loop 104 as well as on the bottom (ie, atrial) side of the loop 104.

[0293] The underlying wire 104C of the resection loop 104 may be constructed of a shape memory metal (e.g., Nitinol) or a similar conductive metal (e.g., stainless steel or copper). As shown in the cross-sectional views of Figures 23, 24, and 25, the underlying wire 104C may have a rectangular, circular, triangular, and square cross-section, respectively.

[0294] The resection loop 104 may be comprised of one or more wires, such as a first wire 104C and a second wire 104D. Both wires may be comprised of a similar material (e.g., Nitinol, stainless steel, copper, silver, or a similar material) or each wire may be comprised of a different material. For example, one wire 104C may be comprised of a metal that better conducts electrical current (e.g., stainless steel, silver, or copper) and the other wire 104D may be comprised of a material that retains its shape between compressed and expanded configurations (e.g., a shape memory metal such as Nitinol). The multiple wires may be electrically isolated or insulated from each other or independently. Different cross-sectional shapes with the same or different materials may further be used as shown in FIGS. 16-18 and 26-28.

[0295] In another example, the resection loop 104 can be constructed from a single wire that includes multiple strands of different wire materials. For example, Figs. 19 and 29 show a wire core 104D that is made of shape memory strands with multiple conductive strands 104C arranged circumferentially around the core 104D. In another example, Fig. 30 includes alternating shape memory strands 104D and conductive strands 104C. In this regard, the different strands can provide both desirable current conduction and the ability to expand from a compressed form to a predetermined loop shape. The multiple wires may be electrically isolated or insulated from each other or independently. Either of these two cable examples can have anywhere from 2 to 49 or more strands within.

[0296] The resection loop can have a variety of different shapes, configurations, and electrical insulator patterns to facilitate removal of tissue surrounding the clip 104, which can provide additional length and / or a predetermined path or geometry, for example. FIG. 101 shows an alternative example of a resection loop 316 having a "saddle" or wavy shape in which each side 314, 315 of the loop curves downward (i.e., proximally toward the catheter 100) and its free end 311 curves upward (i.e., distally away from the catheter 100). The sides 314 and 315 can be insulated, and the middle section 311 and the ends 312 and 313 can be insulated. The middle section 311 contacts or engages tissue on one side of the loop 316, while the ends 312 and 313 contact or engage tissue on the other side. Sides 315 and 316 may be bent outward to increase the width of loop 316, may be bent inward to decrease the width of loop 316, or may be relatively straight to maintain a uniform width of loop 316 (i.e., circular or oval in shape).

[0297] The resection loop 316 can facilitate many different tissue engagement methods, for example, the ends 312 and 313 can be electrically activated in unison initially while the resection loop 316 applies axial tension to the tissue structure, effectively resecting the tissue in contact with these portions 312, 313 and partially releasing the leaflet clip 40. The free end 311 can then be activated to resect the tissue adjacent to it and complete the resection of the leaflet clip 40 from the leaflet. Alternatively, all three portions 311, 312, 313 can be activated simultaneously. Axial tension on the loop 316 can be applied before, during, or intermittently to control the engagement of the loop 316. While this embodiment shows three uninsulated resection regions or portions 311, 312, 313, there can be any number of resection elements (e.g., 1-100) including the entire loop 316 as one continuous uninsulated resection member.

[0298] The inclusion of additional length along the sides 314 and 315 can accommodate other tissue structures present around the leaflet clip 40. The additional length of the sides 314 and 315 can also be deformed such that when tension is applied by the elongated straight section 317, the sides 314 and 315 straighten and stretch the loop 316 to a generally axial shape. During this tensioning and stretching, the axial distance between the free end 311 and the proximal ends 312, 313 increases, including a greater variety of both diameters and approach angles to the clip. Such non-linear paths can also accomplish this and are therefore contemplated in this disclosure, but are not shown here for simplicity.

[0299] FIG. 102 illustrates a delivery mechanism having a resection loop 316 previously described and an outer tubular sheath 320 generally similar to that of the sheath 110 previously described. However, the outer tubular sheath 320 further includes a sheath cutter 321 disposed at and circumferentially around the distal end of the sheath 320. This sheath cutter 321 may have similar structure and properties as the previously described non-insulated portion of the previous resection loop and may similarly be electrically activated to facilitate additional areas of tissue that may be cut. This outer tubular sheath 320 may be used in combination with any of the other instruments disclosed and may be used in a manner that best facilitates the leaflet clip removal procedure. Again, all of the non-insulated cutters 311, 312, 313 and 321 may be activated individually at separate times or all together at the same time.

[0300] Figure 103 shows the embodiment of Figure 102 within a heart valve tissue model 330, with chordae tendineae 21 and leaflet positioning clip 40. This figure shows one example of how instruments 320 and 316 engage tissue on all sides of clip 40 in a manner positioned to resect attached tissue structures from clip instrument 40.

[0301] Another exemplary embodiment of resection loop 350 can be seen in Figure 104, where each side loop portion 314, 315 is bent upward (i.e., distally) and its free end is bent downward (i.e., proximally). Additionally, side loop portions 314, 315 are shown bent laterally outward to increase the width of loop 350. Loop 350 can have a variety of different insulated and non-insulated portions as described in Figures 101-103 (i.e., several individual non-insulated portions or the entire loop is non-insulated).

[0302] 105 and 106 show another embodiment of a removal device 360, which is generally similar to removal device 100, but further includes a first resection loop 104 and a second resection loop 316. In some cases, it may be difficult for a physician to visualize exactly which tissue should be resected to completely remove the cardiac therapy device. Two or more loops allow for a first series of cuts to the valve tissue, and then one or more second cuts (e.g., by tightening the first resection loop) to completely remove the cardiac therapy without requiring dramatic repositioning of the loops. In contrast, a single resection loop may need to be moved, longitudinally repositioned, and / or rotated to completely resect the cardiac therapy.

[0303] In this example, the first cutting loop 104 has a somewhat larger diameter (e.g., similar to the opening of the basket 104) and the second cutting loop 316 has a smaller diameter than the first cutting loop 104 and is located away from the basket 104. Thus, the second loop 316 can be positioned against the leaflets and / or chordae (e.g., in FIG. 107, cut 370A through the anterior lateral chordae and cut 370B through the posterior medial chordae), and cuts 311, 313, and 314 can be activated to make a first series of cuts against the tissue. This first series of cuts may not cut all of the tissue, but cut 104B of the first cutting loop 104 can be cut and then activated to make one or more second cuts to completely remove the remaining tissue from the cardiac treatment device 40 (e.g., along cut 370C on the atrial side of clip 40 in FIG. 107).

[0304] 105 and 106, any combination of loops described herein may be used in this manner. For example, FIG. 108 shows an embodiment 180 having two loops 316 of similar shape and configuration. Thus, any of the loops may differ in the number and pattern of ablations, which may all be activated simultaneously or at different times / patterns. In one example, both resection loops 104 and 316 are connected to the same electrical circuit (e.g., internal control member 108). Alternatively, each loop 104, 316 (or each set of ablations) may have its own electrical circuit (e.g., individual conductive wires) that allows for independent activation from the other resection loops. Additionally, three or four resection loops may be used in an alternating fashion. The resection loops may all be connected to the same removal catheter, or one or more loops may be connected to a catheter separate from the other resection loops and / or basket 104. In some embodiments, one or more resection loops may be placed on the ventricular side of the valve and one or more resection loops may be placed on the atrial side of the valve.

[0305] If the fastening loop 106 has an insulator coating along its entire length, the resection loop 104 may be placed directly over and contacting the fastening loop 106. The resection loop 104 may also be spaced apart from the fastening loop 106 along its length, such as between about 0 mm and about 15 mm.

[0306] Preferably, the inner control member 108 (best shown in Figures 11-13) is flexible enough to navigate the vasculature while having sufficient column strength to push the basket 102 and resection loop 104 out of the outer tubular sheath 110, is capable of efficiently delivering RF energy from the proximal handle to the resection loop, is insulated to prevent current leakage into the bloodstream, and has good torque response to allow the user to rotate the basket and loop as it is deployed in and around the valve.

[0307] In a preferred embodiment, the inner control member 108 consists of an inner control stylet bonded or welded to a more flexible inner control cable, which is then bonded to the resection loop conductive wire tail with a distal coupler. In a preferred embodiment, the inner control stylet, inner control cable, resection loop conductive wire, and distal coupler are the same material (e.g., steel alloy), allowing for a strong welded joint and efficient current delivery throughout. The inner control cable can be a laser cut tube, a stranded cable, a stranded cable tube, a coil, or a combination thereof. In another embodiment, the inner control cable can extend from the proximal handle to the resection loop 104, eliminating the need for an inner control stylet.

[0308] In other embodiments, the inner control member 108 may be two separate wires, one connecting to the fastening loop 106 and the other connecting to the resection loop 104. If both inner control members are disposed in the same single lumen of the outer tubular sheath 110, the basket 102 may be deployed by first advancing the inner basket control member distally until the basket fastening loop 106 is fully exposed. The inner resection loop control member may then be advanced distally to deploy the resection loop 104. Each loop may be rotated, advanced, or pulled back by its respective control member. This allows the operator more degrees of freedom. The heart valve therapy may first be captured or surrounded by the resection loop 104, followed by the basket fastening loop 106 and basket 102. The resection loop 104 may then be closed over the leaflet tissue bridge by pulling back the inner resection loop control member. Once the resection loop is closed on the tissue bridge, one of two steps can take place: 1) the basket clamping wire 104 and basket 102 can be closed by retracting the inner basket control member proximally, or 2) if the resection loop 104 cannot reach the base of the heart valve treatment, RF cutting energy can be applied to cut one side of the device to reach the base of the clip 40 and then the basket 102 can be closed. Once both loops are properly closed on the tissue on the atrial side of the heart valve treatment, the inner resection loop control member is energized with RF power as it is retracted proximally back into the outer delivery sheath 110. The inner resection loop control member delivers ablation energy only to the ablation element via the resection loop 104.

[0309] The internal control members described above can alternatively be located in separate outer tubular sheaths or in separate lumens within the same sheath 110. The system can be designed such that each sheath can be located at a separate orifice (i.e., on opposite sides of the heart valve therapy). Once both loops have captured the heart valve therapy, the same steps as described above are followed.

[0310] The control member insulator covering the outer surface of the inner control stylet and the inner control member is preferably flexible enough so as not to affect the advancement of the delivery catheter through the valve orifice, and is desirably as lubricious as possible so as to minimize friction between the inner control member and the delivery catheter when the inner control member is pushed distally to deploy the basket and resection loop within the left ventricle. For example, the insulator may include a hydrophilic coating, a silicone coating, a Teflon-like coating, a polyolefin coating, a thermoform or thermoset coating, or a fluoropolymer.

[0311] Returning to the basket 102, the length and diameter of the basket 102 may depend on the size of the heart valve treatment device or clip 40. For example, the basket 102 may have a length in the range of about 20 mm to about 50 mm and a diameter in the range of about 10 mm to 20 mm. Depending on the size of the leaflet clip 40 and the angle at which the basket 102 is expected to capture the clip 40, the diameter of the basket 102 may be adjusted. For example, the larger the blocking angle relative to the top surface across the opening of the basket 102, the larger the diameter of the basket 102 should be. In other words, unless the basket 102 is expected to be substantially directly below the clip 40, the basket 102 should be expanded to a diameter much larger than the diameter of the clip 40.

[0312] In one embodiment seen in FIG. 31, the basket 102 can be constructed from a plurality of braided wires. The wires can be constructed from a shape memory material and can be braided over a mandrel of the desired basket size and then heat set so that the braid shape returns to the expanded basket shape after compression. The wires can be constructed from a shape memory material such as Nitinol, or a non-shape memory material such as stainless steel. The wires may also have an insulator coating such as ETFE, polyimide, parylene, silicone, or similar materials. The advantage of a woven basket is that its behavior / performance can be altered by changing the basket wire diameter, basket wire material, and / or weave density (i.e., basket pore size) while keeping the basket diameter and length fixed. The design of the basket diameter and length is primarily determined by the size of the heart valve repair that is planned to be removed. The size, spacing, and number of woven basket eyelets can also be adjusted and optimized. In one example, the pores 102B of the basket 102 when expanded are in the range of about 100 microns to about 4 mm in diameter.

[0313] The wire size is preferably small enough to allow the basket to be easily folded into and deployed from the delivery catheter during the procedure, but large enough to provide rigidity to the basket so that it can open sufficiently in the presence of valve chordae or other structures. The pore size of the basket may vary from woven basket to woven basket depending on the design intent. In general, the pore size should be smaller than either the length, width, or height of the heart valve treatment to avoid embolizing through the basket after the heart valve treatment is resected free. Weaving a basket with very small pores can help filter and capture any debris generated during the tissue resection process.

[0314] One advantage of coating the metal basket is that it ensures that the electrical energy is concentrated within the ablation element and not distributed throughout the metal structure of the basket and into the blood pool. A second advantage of the coating is that it can also reduce friction and therefore facilitate capture of the heart valve therapy within the basket. If the basket is too rough or has too many edges within the basket, the heart valve therapy may not be fully seated within the basket. Adding a lubricious coating or smooth layer to the inner surface of the capture basket can facilitate capture of the heart valve therapy.

[0315] In another embodiment seen in Figures 32, 33 and 34, a removal catheter 150 includes a basket 152 made of a polymer such as silicone, PET, polyester, nylon, polypropylene, Kevlar, or similar material that can be folded or pleated into a radially compressed shape. The basket 152 may be formed with multiple openings sized (e.g., about 100 microns to about 4 mm in diameter) to prevent the passage of both the leaflet clips 40 and other biological material that may detach from the procedure. The basket 152 may be sized similarly to the basket 102 described above. The top opening of the basket 152 may also include multiple loops or passages 152B sized to allow the passage of the fastening loops 106 so that the basket 152 can be closed during the procedure.

[0316] The structure of the polymer basket 152 can be completed using braiding, mesh, weaving, knitting, or injection molding. The possible basket shapes and material combinations are endless, and only a few are described here. It is important to choose a durable polymer material that has high heat resistance, low moisture absorption, and will collapse into the outer sheath many times. Silicone tends to meet these performance requirements best. If the basket is made of silicone, it can be molded into the basket shape as a separate component, or it can be molded directly onto the loop structure. If the basket is made from a flat silicone sheet, it can be cut into a designed pattern and sewn onto the loops into the desired shape.

[0317] Depending on the material selected, the size and spacing of the pores 152A can be adjusted. In general, the pore size can be smaller than either the length, width, or height of the heart valve treatment to avoid embolizing through the basket after the heart valve treatment has been ablated. Using a basket with very small pores can help filter and capture debris generated during the tissue ablation process. Designing the basket with pores can also allow blood to flow through them. Minimizing the forces exerted on the blood to pump (i.e., minimizing the "parachute effect") helps improve the operator's control of the basket. The polymer basket can be made with or without eyelets. If eyelets are present as shown, they are slidably attached to the basket fastening loops. If eyelets are not present, they are securely fastened to the basket fastening loops.

[0318] Because the polymer basket 152 does not conduct electrical current, other embodiments are possible in which the resection loop 104 of the removal catheter 160 also serves as the fastening loop, as shown in Figures 35 and 36. The basket 152 may be attached directly to the insulated portion 104A of the resection loop 104 (or alternatively, the insulation may be formed directly around the non-insulated wire), leaving the exposed non-insulated portion 104B open, which performs the leaflet resection.

[0319] Similar "single loop" embodiments are possible in other shapes and materials. For example, FIG. 37 shows multiple polymer or textile filaments woven together to form a flexible basket shape and relatively large openings (e.g., about 0.5 mm to about 4 mm). FIG. 38 shows multiple polymer or textile fibers woven into a textile basket 164 having relatively small openings (e.g., about 0.5 mm to about 4 mm). FIG. 39 shows polymer sheets sewn together to form a basket 166. In any of these embodiments, the resection loop 104 can be exposed after tightening so that the non-insulated portion 104B can resect the leaflets of the valve.

[0320] In other embodiments, the basket may be partially or entirely comprised of a laser cut basket. For example, Figures 40 and 41 show a plurality of vertical laser cut ribs with eyelets positioned along their length so that a plurality of wires or polymer filaments can be braided or woven. Figures 42 and 43 show a laser cut basket shape entirely made of laser cut shape memory metal (e.g., a tube or sheet of shape memory metal).

[0321] The advantage of a laser cut basket is that its behavior / performance can be altered by changing the tube dimensions and / or cut pattern / density (i.e. basket pore size) while keeping the basket diameter and length fixed. The design of the basket diameter and length is primarily determined by the size of the heart valve treatment planned to be removed. The size, spacing, and number of the laser cut eyelets can also be adjusted and optimized. The material used preferably has shape memory properties, such as Nitinol, allowing the laser cut portion of the tube to expand and shape. By using a material with shape memory, the basket can be repeatedly collapsed and returned to the same shape. The wire size is preferably small enough to allow it to be easily folded into and deployed from the delivery catheter during the procedure, but large enough to provide rigidity to the basket so that it can be opened sufficiently in the presence of valve chordae or other structures.

[0322] The pore size of the basket can be varied in the laser cut design by altering the cut pattern to achieve the desired results. For example, the pore size can vary within a range of about 100 microns to about 4 mm. In general, the pore size should be smaller than either the length, width, or height of the heart valve treatment to avoid embolizing through the basket after the heart valve treatment is cut free. One unique advantage of laser cut baskets is that the pore size and spacing can vary throughout the length of the basket. For example, the proximal open side of the basket can have large pores with a certain pattern density. The pore size and pattern density can be smaller and denser toward the distal end of the basket.

[0323] Any of the basket embodiments described herein can further include an outer covering that serves to collect any debris or embolic material released during the procedure. Such an outer covering can include a solid or perforated polymer sheet, a woven fabric, a tubular shape formed from relatively small, finely woven metal wires, or similar materials. In one particular embodiment, the interior of the basket can have a non-conductive liner, film, or coating (e.g., silicone) on its inner surface to help prevent electrical communication with the ablation element 104.

[0324] In one embodiment, the removal catheter 100 can include a proximal handle 170, as shown in Figures 44 and 45. The handle 170 includes an outer housing 172 and a sliding member 174 configured to slide within a longitudinal groove in the housing 172. The housing 172 can be connected to the outer tubular sheath 110, while the sliding member 174 is connected to the inner control member 108, allowing a user to adjust the position of the sliding member 174 with their thumb to effect corresponding longitudinal movement of the inner control member 108, basket 102, and resection loop 106.

[0325] Optionally, the handle 170 may have a fluid connection port 176 (e.g., a Luer port) in communication with the interior of the inner passageway of the outer tubular sheath 110 so that an electrically neutral solution (e.g., a dextrose solution) can be delivered to the area near the resection loop to amplify the tissue ablation effect and minimize energy loss around the area to the blood pool. The amount and timing of this fluid can be determined by the physician (e.g., via a syringe) or via an electrically actuated pump mechanism based on the position of the resection loop 106 (i.e., when the resection loop is outside the outer tubular sheath and in good contact with the desired tissue 110).

[0326] As shown in FIG. 45 , the handle 170 may include a locking mechanism 173 near the distal end of the housing 172 that locks the inner control member 108 in position relative to the outer tubular sheath 110. For example, the locking mechanism 173 may include a handle 177 configured to rotate a cam member 178 that surrounds the proximal end of the inner control member 108. When the handle 177 rotates the member 178, the cam member 178 forms an interference fit with the inside of the housing 172, locking the control member 108 in its longitudinal position. When the handle 177 rotates the cam member 178 in the opposite direction, the interference fit between the cam member 178 and the housing 172 is released, releasing the inner control member 108 so that the inner control member can slide longitudinally within the handle 170.

[0327] FIG. 46 shows an embodiment of the ablation catheter 100 having a current overflow hole 111 in the outer tubular sheath 110. This embodiment is most beneficial for embodiments having a single clamping and resection loop and either a polymer or minimally conductive basket 102. When the ablation element 104 and fixation basket 102 are retracted inside the outer tubular sheath 110 to begin the ablation of the leaflet tissue, the distal end of the outer tubular sheath 110 is closed off from the blood pool. If this were to occur after the tissue has been ablated, the current being supplied to the ablation element 104 would no longer be transferred to the tissue or blood, but would instead transfer heat and / or electricity through the basket 102, which could cause damage. The current overflow hole 111 in the outer tubular sheath 110 can ensure that the ablation element 104 is always in communication with the blood pool, even after the ablation is completed. In this way, the current chooses to flow through the blood to the opposing RF electrode attached elsewhere in the patient, as opposed to the basket.

[0328] Alternatively, as shown in FIG. 47, the wire 113 can be attached to the inner control member 108 to ensure that the current path always involves the blood pool, even after the cut is completed. The wire 113 is preferably designed to be long enough to always protrude from the distal end of the outer tubular sheath 110, even if the basket 102 is completely collapsed inside the outer tubular sheath 110. It is also preferable to have a very small area of ​​exposed metal at the very distal end, with the remainder being insulated. In this way, once the cut is completed, the current chooses to flow through the lower resistance wire to the blood, as opposed to flowing through the higher resistance basket 102 (e.g., silicone).

[0329] 48-53 show side views of the removal catheter 100 deploying and clamping the basket 102. In FIG. 48, the basket 102, clamping loop 106, and resection loop 104 are all disposed within an outer tubular sheath 110. As shown in this figure, these components are radially compressed to a relatively small diameter to allow passage through the patient's blood vessels (keeping them compressed within the outer tubular sheath allows them to pass through smaller orifices and also between multiple clips).

[0330] 49, the inner control member 108 is advanced distally (e.g., via the sliding member 174) such that the basket 102 begins to expand radially out of the outer tubular sheath 110. This distal movement continues until both the basket 102 and resection loop 104 are deployed and fully expanded outside of the sheath 110, as shown in FIG.

[0331] 51 and 52 show that the inner control wire 108 is being pulled back, which causes both the clamping loop 106 and the resection wire 104 to be pulled back and radially closed. Typically, RF energy is activated during this time to resect tissue at the leaflets as the resection wire 104 closes. Once the resection loop 104 is fully pulled inside the outer tubular sheath 110, the RF current is deactivated. This can be accomplished in a number of different ways. For example, the aforementioned sliding member 174 of the handle 170 can include a position switch that turns the RF energy on and off at a predetermined longitudinal position. Alternatively, a manual on / off switch can be included in the handle 170 or the RF power source.

[0332] A radiopaque marker can be placed at the distal end of the outer tubular sheath 110 to aid in determining when to manually turn off the RF energy. When the physician performs the tissue bridge ablation, they look to the fluoroscopy screen. Since tissue is typically not visible under fluoroscopy, it can be useful to provide the operator with a visual indicator on the catheter 100 that indicates that the tissue bridge has been ablated. The inner control member 108 and resection loop 104 are pulled back into the sheath 110 during the ablation process, and the radiopaque marker is positioned such that when the operator sees the entire resection loop 104 proximal to the radiopaque marker under fluoroscopy, the tissue bridge has been ablated. Not only is this a useful visual indicator for the operator, but it also makes the procedure safer. Once the resection loop 104 passes the radiopaque marker, the RF ablation energy can be immediately terminated by the operator, preventing unintended heating due to applying power longer than necessary.

[0333] Finally, the opening in the basket 102 is nearly completely pinched closed and the position of the inner control member 108 may be locked in place if desired (e.g., by a locking mechanism 173 on the handle 170). The basket 102 is maintained outside the outer tubular sheath 110 and is withdrawn into the larger guide catheter that will be used during the procedure.

[0334] The present invention includes different methods or techniques for removing heart valve treatments, such as the valve clip 40. For example, Figures 56-61 show a removal procedure that traverses the atrial septum 18 and accesses the mitral valve 20. Although exemplary access methods and procedures are described, it should be understood that variations are possible based on known catheter access techniques. Furthermore, these access techniques may be used with any of the embodiments herein.

[0335] The mitral valve access procedure of Figures 56-61, in one embodiment, can include an inner control member 108, an outer tubular sheath 110, an inner steerable catheter 180, and an outer transseptal guide catheter 182, which can be seen separately in Figure 54 and together in Figure 55, and are discussed further below. The three nested, but independently curved, axially articulated catheters allow for placement of the removal device anywhere within the heart, regardless of size or procedural location. However, other tools, sheaths, catheters, and similar devices can alternatively be used to direct the removal catheter 100, as described below.

[0336] Referring first to FIG. 56, the left atrium 12 may be accessed by advancing a transseptal guidewire or needle (e.g., via the inferior vena cava 17 or superior vena cava 19) into the atrial septum 18, using the guidewire to cross the atrial septum 18, and finally moving the guidewire into the left atrium. A relatively large diameter outer transseptal guide catheter 182 may then be advanced over the guidewire and through the atrial septum 18 such that its distal end is located in the left atrium 12. Alternatively, the transseptal guide catheter 182 may be advanced through the atrial septum 18 without the use of a transseptal guidewire. The outer transseptal guide catheter 182 may have a predetermined curve or bend that helps angle it from the inferior vena cava 17 toward the atrial septum 18, if desired.

[0337] The guidewire may be removed and the inner steerable guide catheter 180 can then be advanced through the outer transseptal guide catheter 182 so that its distal end is located within the left atrium 12. The distal end of the inner steerable guide catheter 180 can be "steered" or deflected so that its distal opening is directed to a desired location of the mitral valve 20. Because the guide catheters are independent of the outer transseptal guide catheter 182, the physician can direct the inner steerable guide catheter 180 to any location along the mitral valve 20, rotate it, advance / pull it back, or change the degree of deflection while keeping the outer transseptal guide catheter 182 in the same position.

[0338] In the example of a mitral valve 20 having leaflet clips 40, the inner steerable guide catheter 180 is preferably oriented toward either of two valve openings on each side of the central clip 40 (see top view in FIG. 6). Once oriented to the desired target location, the removal catheter 100 is advanced from its distal end through the inner steerable guide catheter 180, into the left atrium 12, through one of the side openings of the mitral valve 20, and into the left ventricle 14, as shown in FIG.

[0339] 57 and 58, the inner control member 108 is advanced distally through the outer tubular sheath 110 of the removal catheter 100, advancing the capture basket 102, fastening loop 106, and resection loop 104 from the outer tubular sheath 110. Preferably, the capture basket 102, fastening loop 106, and resection loop 104 are connected to the inner control member 108 such that the openings of the basket 102 and the resection loop 104 extend in an orientation that faces or points toward the leaflet clip 40. For example, the plane 103A of the openings of the basket 102 and the resection loop 104 can be at an angle 103C between 45 degrees and 135 degrees (e.g., 90 degrees) relative to the axis 103B of the inner control member 108. The inner control member 108 can be rotated relative to the outer tubular sheath 110 (or alternatively the total removal catheter 100 can be rotated), thereby rotating the capture basket 102, fastening loop 106, and resection loop 104 within the left ventricle 14. In this manner, the physician can align or orient the basket 102 in a desired position beneath the leaflet clip 40.

[0340] Once the capture basket 102, fastening loop 106, and resection loop 104 are deployed, the inner control member 108 (or alternatively the outer tubular sheath 110) can be retracted proximally such that the leaflet clip 40 is disposed inside the basket 102, as shown in FIG. 59. Preferably, both the resection loop 104 and the fastening loop 106 are disposed above the leaflet clip 40, i.e., between the leaflet clip 40 and the bottom adjacent surfaces of the leaflets 22 and 24.

[0341] 60, the inner control member 108 is retracted proximally causing the fastening loop 106 and the resection loop 104 to partially retract, causing the top opening of the basket 102 to close over the leaflet clip 40 and the diameter of the resection loop 104 to decrease so that it engages between the atrial portions of the leaflets 22, 24 and the leaflet clip 40.

[0342] As shown in Fig. 61, RF energy is applied to the resection loop 104 as it is pulled back proximally, decreasing its diameter. The non-insulated portion 104B presses against the portions of the leaflets 22, 24 nearest the leaflet clip 40, thereby resecting this tissue and releasing the leaflet clip 40 from the mitral valve 20. The RF energy is turned off to the resection loop 104. Preferably, the outer transseptal guide catheter 182 has a diameter sufficient to accommodate the basket 102 with the leaflet clip 40 contained therein. However, the removal catheter 100, inner steerable catheter 180, and outer transseptal guide catheter 182 can all be withdrawn from the patient as a single unit if desired.

[0343] It is further contemplated that a prosthetic valve may be placed in place at the mitral valve 20 after removal of the leaflet clip 40. If a guidewire is used during the removal procedure, it may be used to advance and orient a valve delivery catheter to deliver and implant the prosthetic valve. One example of such a prosthetic valve replacement is described in U.S. Patent No. 8,579,964, entitled Transcatheter Mitral Valve Prosthesis, the contents of which are incorporated herein by reference.

[0344] Additionally, after removal of the leaflet clip, it is contemplated that a blood flow management instrument, such as a spacer, catheter, balloon, or other device, may be in place and expanded at the valve to manage blood flow across the valve until such time that additional therapy, such as a replacement valve, can be delivered.

[0345] 62-65 illustrate another method of removing a leaflet positioning device, such as a leaflet clip 40, by a transapical approach. First, as shown in FIG 62, an incision is made in the sternum (e.g., between the manubrium and the sternum) and a transapical sheath 184 is advanced through the incision, through the apex of the heart 10, and into the left ventricle 14. The removal catheter 100 is then advanced through the transapical sheath 184 such that the distal end of the outer tubular sheath 110 extends into the left ventricle 14.

[0346] 63, the internal control member 108 is advanced distally within the outer tubular sheath 110 to release and expand the basket 102 and resection loop 104 into the left ventricle 14. The fastening loop 106 and resection loop 104 preferably have a predetermined curvature (e.g., a heat-set curvature / curve) that directs the top opening of the basket 102 and the opening of the resection loop 104 toward the leaflet clip 40. For example, the plane of the top opening of the basket 102 and the opening of the resection loop 104 can be within a range of 135 degrees to 225 degrees (e.g., about 180 degrees) relative to the axis of the internal control member 108. The internal control member 108 can be further rotated (or the entire removal catheter 100 can be rotated) by the physician to optimally align the resection loop 104 and basket 102 with the leaflet clip 40.

[0347] As shown in FIG. 64, the outer tubular sheath 110 is further advanced from the transapical sheath 184 such that the leaflet clip 40 is fully disposed within the basket 102. As shown in FIG. 65, the inner control member 108 is pulled back proximally to reduce the diameter of the fastening loop 106 and the resection loop 104. As the diameter of the loops 104 and 106 decreases, the top opening of the basket 102 decreases, trapping the leaflet clip 40 therein. Furthermore, as the resection loop 104 decreases, RF energy is activated and delivered to the loop 104, allowing the non-insulated portion 104B to resect the leaflet tissue immediately above the leaflet clip 40.

[0348] Preferably, the capture basket 102, fastening loop 106, and resection loop 104 are connected to the inner control member 108 such that the openings of the basket 102 and the resection loop 104 extend in an orientation that faces or points toward the leaflet clip 40. For example, the plane 103A of the openings of the basket 102 and the resection loop 104 can be at an angle 103C between 25 degrees and 135 degrees (e.g., 90 degrees) relative to the axis 103B of the inner control member 108.

[0349] If the transapical sheath 184 has a large enough diameter, the outer tubular sheath 110 can be retracted proximally and the basket 102 containing the leaflet clips 40 withdrawn into the passageway of the transapical sheath 184 for removal. If the basket 102 and leaflet clips 40 are too large for the transapical sheath 184, both the sheath 184 and the removal catheter 100 can be withdrawn simultaneously.

[0350] 66 and 67 illustrate another method of removing a heart valve treatment such as a leaflet clip 40 via a trans-aortic approach. With reference to FIG. 66, an aortic guide catheter 186 is first placed into the aorta 11 and advanced into the left ventricle 14. The aortic guide catheter 186 may have a fixed curve / shape that helps the physician direct the distal end of the catheter 186 under the leaflet clip 40. Alternatively or additionally, the aortic guide catheter 186 may have a steerable mechanism that allows for deflection in different directions.

[0351] The removal catheter 100 is then advanced through the aortic guide catheter 186 such that the distal end of the outer tubular sheath 110 extends from the distal end of the catheter 186 into the left ventricle 14. The inner control member 108 is advanced further distally relative to the outer tubular sheath 110 such that the basket 102 and resection loop 104 are deployed, expanded, and positioned within the left ventricle 14. The openings of the basket 102 and the resection loop 104 are both or oriented to face the leaflet clip 40. For example, the planes of the openings of the basket 102 and the resection loop 104 can be within a range of about 300 degrees and 45 degrees (e.g., about 320 degrees) relative to the axis of the inner control member 108.

[0352] 67, the aortic guide catheter 186 is moved or deflected (in the case of a steerable catheter) so that the resection loop 104 and basket 102 are positioned over the leaflet clip 40. The inner control member 108 is pulled back proximally inside 110, which reduces the diameter of the fastening loop 106 and resection loop 104 and closes the top opening of the basket 102. As the diameter of the resection loop 104 decreases, RF energy is delivered to the loop 104, allowing the uninsulated portion 104 to ablate the area of ​​leaflet tissue adjacent the leaflet clip 40, thereby releasing the leaflet clip 40 from the mitral valve 20. The basket 102 and leaflet clip 40 can be pulled back through the aortic guide catheter 186, or all of the catheters can be removed simultaneously as a single unit.

[0353] The present invention also contemplates the use of a removal catheter 100 (or any of the variations described herein) on the tricuspid valve 15, as shown in FIG. 68 and FIG. 69. Referring initially to FIG. 68, an outer tricuspid guide catheter 188 is first delivered to the right atrium 16, either by an approach through the inferior vena cava 17 or the superior vena cava 19. The tricuspid guide catheter 188 can include a fixed curve at its distal end to aid its distal opening towards the tricuspid valve 15, or can include a steering mechanism to do so. An inner intermediate catheter 189 can then be advanced through the outer tricuspid guide catheter 188 to provide a better angle towards the tricuspid valve 15. For example, the inner intermediate catheter 189 may have a fixed curve towards the tricuspid valve 15, or may include a steerable catheter mechanism to allow the physician to deflect the distal end of the catheter 189 towards the tricuspid valve 15.

[0354] The removal catheter 100 is then advanced through the inner intermediate catheter 189, out the distal end of the inner intermediate catheter 189, into the right atrium 16, through the tricuspid valve 15 and into the right ventricle 13. Because the leaflet clip 40 is typically positioned in the center of the valve 15 (e.g., similar to the top view of the mitral valve in FIG. 6 ) and creates a valve opening laterally, the removal catheter 100 is preferably positioned on each side of the leaflet clip 40.

[0355] The inner control member 108 is advanced further distally relative to the outer tubular sheath 110 such that the basket 102 and resection loop 104 are deployed, expanded, and positioned within the right ventricle 13. The openings of the basket 102 and the resection loop 104 are oriented together or facing the leaflet clip 40. For example, the plane 103A of the openings of the basket 102 and the resection loop 104 may be at an angle 103C within a range of about 0 to 90 degrees (e.g., about 45 degrees) relative to the axis 103B of the inner control member 108. The removal catheter 100 is retracted proximally relative to the inner intermediate catheter 189 such that the resection loop 104 and the basket 102 are positioned above and outside the leaflet clip 40.

[0356] The inner control member 108 is retracted proximally, thereby decreasing the diameter of the fastening loop 106 and the resection loop 104 and closing the top opening of the basket 102. As the diameter of the resection loop 104 decreases, RF energy is delivered to the loop 104, allowing the uninsulated portion 104 to resect the area of ​​leaflet tissue adjacent to the leaflet clip 40, thereby releasing the leaflet clip 40 from the tricuspid valve 15. The basket 102 and leaflet clip 40 can be retracted through the inner intermediate catheter 189, or all of the catheters can be removed simultaneously as a single unit.

[0357] It is to be understood that any of the embodiments herein can be used in accordance with the access and delivery methods described in this application. Additionally, additional methods can be used in conjunction with these access and delivery methods, such as delivery and implantation of prosthetic valves (either mitral or tricuspid).

[0358] The removal catheter embodiments described above may include a basket or similar device for capturing a heart valve treatment, such as leaflet clip 40, although different capturing techniques and devices are contemplated.

[0359] 70-72 show a removal catheter 200 for removing the heart valve treatment leaflet clip 40. The removal catheter 200 includes an elongated piercing member 202 for piercing the device and an outer ablation catheter 204 disposed over the piercing member 202. The elongated piercing member 202 can be a wire, catheter, or similar elongated device having a pointed, helical shaped distal end, expandable barbs, or rotating elements such that the elongated piercing member 202 can be forced (and optionally rotated or expanded) into the apex of the leaflet clip 40 to initially engage or capture the leaflet clip 40, as shown in FIG.

[0360] As shown in Fig. 71, the outer ablation catheter 204 is advanced distally over the elongated piercing member 202 until its distal end contacts the upper surface of the leaflet, as shown in Fig. 71. The outer ablation catheter 204 can be configured to ablate the leaflet tissue with a variety of different mechanisms, such as mechanical (e.g., rotation or forward pressure) and / or electrosurgical ablation devices (i.e., electrical or cryo). Once released from the leaflet tissue, the leaflet clip 40 can be removed by the elongated piercing member 202, as shown in Fig. 72.

[0361] 73-75 show a removal catheter 210 similar to the catheter 200 described above, but the ablation catheter 212 also includes a gripping mechanism having two articulated jaw members connected via a joint (FIG. 76). After the elongated piercing member 202 engages the leaflet clip 40 (FIG. 73), the outer resection member 212 advances distally over the elongated piercing member 202 until it contacts the upper surface of the leaflet (FIG. 74). The articulated jaw members preferably include a tissue resection mechanism at their ends, such as a blade or an electro / cryoelectrosurgical resection device mechanism, allowing for the resection of leaflet tissue surrounding the leaflet clip 40. Finally, in FIG. 75, the jaw members of the ablation catheter 212 approach each other to engage and grip the tissue clip 40.

[0362] 77-82 show another embodiment of a removal catheter 220 that is embedded within a previously placed leaflet clip 40, followed by passage of a loop-based tool 224 that encapsulates, excises, and removes the clip 40. In FIG. 77, the loop-based removal catheter 220 includes an anchoring mechanism 226 connected to a central push rod 227, a side push rod 223, and a pushable element 225.

[0363] FIG. 78 shows an end view of a loop-based removal catheter 220, which can be circular, elliptical, multi-segmented, or a combination of these shapes and elements. The side rods 223 push the pushable element 225, and the central push rod 227 applies force to the anchoring mechanism 226. In FIG. 79, the entire loop-based removal catheter 220 is folded for placement within the delivery catheter sheath 221. In FIG. 80, the anchoring mechanism 226 is advanced into the heart valve treatment hardware (i.e., leaflet clip 40) using the central push rod 227 and the pushable element 125. In FIG. 78 and FIG. 79, the side push rods 223 are then used to push the pushable element 225 to wrap the loop-based removal catheter 220 completely or partially around the leaflet clip 40. The ablation is performed mechanically or electrically, after which the target tissue is removed.

[0364] 83-88 show a removal catheter 230 that is implanted into a previously placed heart valve treatment (e.g., leaflet clip 40) and then a tool is passed to expand the leaflet clip 40, after which the hardware is removed. In FIG. 83, a steerable guide catheter 231 is used to position a removal catheter 232 that includes an expansion tool 234 for expanding the leaflet clip 40. The expansion tool 234 may have barbs, anchors, or embedding mechanisms to remove or grasp native or foreign leaflets or tissue material from the tissue clip 40. In FIG. 84, an anchor 235 is advanced and implanted. In FIG. 85, the expansion tool 234 is advanced within the leaflet clip 40. In FIG. 86, the expansion tool 235 is mechanically expanded to expand the leaflet clip 40. The expansion may be assisted by electrostatic charge, heating, hydraulic means, rotation, internal or external ultrasound or energy. The tissue is excised from the leaflet clip 40. In Fig. 89, the expansion tool 235 is closed and removed away from the leaflets. Fig. 88 shows a similar approach using a balloon expandable element 129.

[0365] 89 and 90 are cross-sectional views of a mitral valve 20 that has been treated with a heart valve therapy that includes one or more chordae tendineae structures 50. Chordae structures 50 typically include chordae or strands 52 connected to the leaflets and the left ventricle via anchors 54. Chordae 52 may be anchored to the ventricular side of the leaflets 24 (FIG. 89) or the atrial side of the leaflets 24 (FIG. 90). As will be further described in the embodiments below, devices similar to those used to remove leaflet clips 40 can be used to remove the chordae tendineae structures 50.

[0366] 91-92 show a removal tool 240 for ablation and capture of a previously placed heart valve repair, including chordae or structures implanted in the valve leaflets. In FIG. 91, the procedure is performed using the previously described ablation catheter 212, which can open, close, energize, and remove hardware, similar to the description above for other heart valve repairs in FIG. 73-76.

[0367] In Figures 93-97, the procedure is performed through the passage of a loop-based tool 250 that encapsulates, cuts, and removes hardware, similar to the description above of Figures 77-82.

[0368] In Figures 98-100, the procedure is performed using an ablation catheter 260, similar to that described above for other heart valve treatments shown in Figures 70-72.

[0369] Additionally, flow restriction devices can be used to restrict flow during any of the procedures described herein. For example, FIG. 109 illustrates an embodiment of the removal catheter 100 of FIG. 60 with an additional flow restriction device 341. This flow restriction device 341 can be placed in the area of ​​the valve 20 (e.g., through the valve 20) before, during, or after removal of the clip 40, and maintained in the valve area to manage the patient's blood flow by restricting blood flow. The flow restriction device 341 can be any flow restriction device known to those skilled in the art, such as, but not limited to, a balloon, a covered stent, or a catheter. Any or all of these examples, by themselves or in combination with the valve structure, are configured to occupy or have the ability to expand to a clinically appropriate space to manage blood flow. The flow restriction device 341 can be introduced independently through delivery catheters 342 and 343, as shown here. Additionally, the flow restriction device 341 can be integrated into a delivery mechanism, such as an inner steerable catheter 180. Alternatively, the flow restriction device 341 may be another therapy delivery system, such as, but not limited to, a heart valve.

[0370] Maintaining good mechanical contact or force between the leaflet tissue and the ablation element (e.g., the ablation wire 104) can be useful when performing the ablation procedures herein, particularly when using RF energy as the mechanism for performing the ablation, which can be important to prevent the electrodes of the ablation element / loop from being exposed to large amounts of blood.

[0371] When using constant power generators, such as many commercially available RF energy generators, the ablation element is generally seen by the generator as having a low impedance (e.g., 0-300 ohms) when nearly exposed to the patient's blood. This low impedance may result in insufficient voltage for tissue ablation. In these situations, some RF energy generators increase the current to maintain a constant power level.

[0372] In contrast, when the ablation element is pressed firmly against the patient's tissue and has little exposure to the patient's blood, it will be perceived by the generator as having a relatively high impedance (e.g., greater than 300 ohms) or a higher resistance to the current. This higher resistance may cause the generator to increase the voltage output to maintain constant power. Once the voltage reaches a certain level, the tissue ablation process will begin and continue as long as the ablation element remains in contact with the target tissue.

[0373] This phenomenon can be exploited to enable electrosurgery within the heart and the patient's blood pool. It may therefore be useful in the present invention to provide a mechanism for creating and / or helping to maintain a pressure or force between the ablation element and the target tissue.

[0374] Generally, when considering removal of an implanted valve clip 40, it may be useful to consider several factors to ensure sufficient mechanical force between the cutting element and the target leaflet tissue, including: 1) the length of leaflet tissue inserted into the arms of the valve clip 40, 2) the chordae tendineae extending circumferentially from the valve clip 40, and 3) the use of multiple valve clips 40, their spacing, and angle of position.

[0375] Furthermore, there are at least four different possible scenarios for removal of the valve clip: 1) when the resection loop is clamped to the atrial side of the valve clip 40 without the need for any additional "counterforce" against the clip 40 (as described in previous embodiments / methods herein); 2) when it is useful or necessary to apply a counterforce to the valve clip 40 to stretch the tissue so that the resection loop can be clamped to the atrial side of the valve clip 40; 3) when a counterforce is useful or necessary and the resection loop must first cut a portion of the leaflet side tissue before being clamped to the atrial side of the valve clip 40; and 4) when a resection snare is used to substantially release the engaged tissue from the clip 40 to facilitate engagement of the resection loop and basket.

[0376] In the first scenario, as previously described herein, the resection loop and basket may be placed onto the valve clip 40 and the resection loop may be clamped onto the tissue bridge without the use of a separate device such that the resection loop is on the atrial side of the valve clip 40. This technique has been previously described herein. Clamping the resection loop in this manner presses the resection element firmly against the tissue and moves through the entire tissue bridge as it is retracted into the delivery catheter.

[0377] In the second scenario, some method of pushing or pulling the valve clip 40 in and out as the resection loop is retracted or clamped is provided. This counter force assists in stretching the tissue into / towards the left ventricle 14 and away from the direction of pulling of the resection loop so that the resection loop can be placed and clamped on the atrial side of the valve clip 40. Application of this counter force may be useful or even necessary if a relatively large length of leaflet tissue is inserted into the arms of the clip 40, multiple clips 40 are implanted (especially if the clips 40 are in close proximity), the leaflets are too pliable, the leaflets are too stiff, or a relatively large tissue bridge has previously been created.

[0378] In the third scenario, the opposing force stabilizes the valve clip 40 and leaflets and helps draw the cutting loop tightly against the edge of the leaflet. Once firmly pressed against the leaflet tissue, the cutting loop can be pulled to the atrial side of the valve clip 40 to make the initial cut, and then the cutting loop can be tightened to complete the final cut.

[0379] In a fourth scenario, removal of engaged tissue may be necessary to facilitate engagement of the snare and allow the snare to provide a counter force that stabilizes the valve clip.

[0380] In the context of these scenarios, there are several embodiments and methods available for creating an opposing force away from the left atrium 12 and into / directed into the left ventricle 14.

[0381] In one example, a steerable catheter 180 for delivering an ablation and capture catheter may be used to push the leaflets 22, 24 and the valve clip 40 to create an opposing force towards the left ventricle 14. For example, a distal blade of the distal opening may be positioned against the leaflets and / or the valve clip 40.

[0382] As shown in FIG. 142, in another example, a pushing catheter 470 can be used to push the valve clip 40 from the left atrial side of the valve clip 40 toward the left ventricle. An elongated standard catheter or a steerable catheter can be used, or the catheter 470 can further include a dedicated distal end portion 472 to assist in pushing or engaging the valve clip 40. For example, the distal end portion 472 can be selectively expandable (e.g., a balloon or expandable mesh structure) that can be expanded to better contact the valve clip 40. Alternatively or additionally, the distal end portion 472 can have a blunted distal end. Alternatively or additionally, the distal end portion 472 can be configured to mechanically contact the valve clip 40 or the leaflet tissue immediately adjacent the valve clip 40. For example, the devices and mechanisms shown in FIGS. 70-100 can be used to contact the valve clip 40 or the adjacent tissue.

[0383] In any of these configurations, the catheter 470 can be pressed against the valve clip 40 from the left atrium 12 toward the left ventricle 14, and then the resection loop can be placed between the atrial side of the valve clip 40 and the leaflets 22, 24. Finally, the resection loop (e.g., any of the embodiments described herein) can be activated to resect the leaflet tissue.

[0384] In yet another example, the valve clip 40 may be retracted from its location within the left ventricle 14 further into the left ventricle 14 to create an opposing force to position the resection loop and enable tissue resection as previously described.

[0385] 110 and 111 show an embodiment of a removal system 400 for creating a counterforce by retracting the valve clip 40 into the left ventricle 14, which includes both a resection and capture catheter 403 and a separate snare catheter 401 (or alternatively, a separate resection catheter and a separate capture catheter). The snare catheter 401 can be used to first grasp the valve clip 40 and retract it further into the left ventricle 14, and the resection and capture catheter 403 can be used to resect the leaflets 22, 24 and capture the valve clip 40. Note that this technique can also be used with other valves, such as the tricuspid valve.

[0386] The resection and capture catheter 403 is generally similar to the previously described embodiments and may include any of the variations previously described in that regard. For example, the resection and capture catheter 403 may include a basket 102 and a resection loop 404 connected to an elongated inner control member 108 that moves all of the components in and out of a tubular jacket or sheath 110.

[0387] As best seen in FIGS. 112 and 113, the basket 102 may include a basket tip 414 at its distal end. The basket tip 414 may serve one or more of the following purposes. First, the basket tip 414 may connect to or receive the ends of the wires that make up the basket 102. In one example, the basket tip 414 includes a cylindrical wall with multiple openings 414B through which the ends of the wires pass to prevent them from unraveling and injuring the patient. The ends of the wires may be tied, welded, or glued within the basket tip 414. Alternatively, the wire ends may be welded or fused together with the basket tip 414 without the need for openings 414B. The basket 102 may be woven with a single wire, in which case only two openings 414B may be required. Alternatively, the basket 102 may be woven with multiple wires, in which case multiple openings 414B (e.g., two for each wire) may be required.

[0388] Second, the basket tip 414 has an atraumatic distal end shape 414A that helps to prevent tissue inside the patient from being traumatized by the basket tip 414. For example, the atraumatic distal end shape 414A can be spherical, round, elliptical, or conical. This basket tip 414 can also be used with any of the other embodiments herein.

[0389] 110 and 111, resection and capture catheter 403 further includes a resection element or loop 404 that is constructed similarly to the previously described embodiments and can be used in a similar manner. However, resection loop 404 has a saddle shape similar to resection loop 350. That is, resection loop 404 has sides that form a valley shape that slopes or curves distally downward and then proximally upward. This shape is desirable because it allows loop 404 to maintain a desired resection angle relative to the remaining elements of catheter 403 as resection loop 404 is retracted proximally into outer sheath 110. For example, if resection loop 404 forms a perpendicular right angle with inner control member 108, there may be a tendency for loop 404 to angle downward as the right angle joint is retracted into outer sheath 110. However, the curved or saddle shape helps maintain the end of loop 404 in the desired vertical range as retraction occurs. Doing so can be particularly useful when the electrodes of the resection loop 404 are located on the opposite side of the loop from the inner control member 108. This resection loop 404 can also be used in any of the embodiments described herein.

[0390] The snare catheter 401 includes a snare loop 420 connected to or near the distal end of an inner control member 418 (similar to member 108) that moves longitudinally within the lumen of an outer tubular jacket or sheath 416. This allows the snare loop 420 to be moved in and out of the sheath 416 by the inner control member 418. The outer tubular sheath 416 may have an opening at its distal bottom (i.e., the axis of the sheath) similar to the sheath 110, and may include a tip member 422 having an opening in a sidewall that extends into the inner lumen of the sheath 416 (e.g., a side opening that opens in a non-axial direction relative to the sheath). The outer sheath 416 may have an elongated shape with a sufficient length to enter the patient's body and reach the inside of the patient's heart (e.g., the mitral valve) at its distal end. The lumen may open at the proximal end of the outer tubular sheath 416. The inner control member 418 may be a wire, tube, or similar elongated member and may extend from the proximal end to the distal end of the outer tubular sheath 416 .

[0391] If desired, the snare loop 420 may include a resection element (e.g., an RF electrode near the tip) as described above, which may engage and at least partially resect tissue surrounding the clip to facilitate initial capture and removal of the valve clip 40. Further resection and capture procedures may be performed thereafter. At least partial removal of the engaged tissue may be required at this initial stage to facilitate engagement of the snare loop 420 and to provide a counter force to stabilize the valve clip 40. For example, a channel or valley may be cut in the tissue surrounding the valve clip 40, which may allow the snare loop 420 to more firmly engage the valve clip 40. One example of such a configuration is shown in FIGS. 145 and 146, which includes an RF electrode 421 at the distal end of the snare loop 420 in addition to an RF electrode 407 at the distal end of the resection loop 404. However, any type of resection element may be used. Alternatively, the particular electrode may be a radiopaque marker.

[0392] The snare loop 420 can have a variety of different shapes configured to grip the valve clip 40. For example, FIGS. 114 and 115 illustrate a "saddle-shaped" or arc-shaped loop (i.e., the sides curve distally downward and then return upward to join with each other to form an arc or concave shape) similar to the resection loop 404. The curved shape can prevent the distal end or tip of the snare loop 420 from moving distally downward beyond the distal end of the snare catheter 401. In other words, when the snare loop 420 is fully extended from the catheter 401, its distal angle is upward, so that as the loop 420 is retracted, it angles distally downward. However, because the distal end is curved proximally, the distal angle of the loop 420 is not sufficient to dislodge the loop 420 from the valve clip 40. In other words, the loop 420 is curved proximally enough so that the distal end of the loop is not located distally beyond the distal end of the snare catheter 401 .

[0393] 116, the snare loop 424 may have a generally circular shape and may optionally have a recessed or curved section 424A extending radially outwardly opposite the outer sheath 416. Although a single notch or recess 424A is illustrated, the sections 424A may be provided partially or entirely around the circumference of the snare loop 424.

[0394] The snare loop 424 has a shape that is given a shape memory to connect to the internal control member 418 at approximately 90 degrees. In some cases, as the 90 degree bend is retracted into the snare catheter 401, the loop 424 may tilt or bend downward, which may cause the loop 424 to become dislodged from the valve clip 40. On the other hand, the saddle shaped snare loop 420 has a distal / downward arc curve that helps maintain the original orientation of the loop 420 as it is retracted into the snare catheter 401, thereby better maintaining the loop 420 on the valve clip 40.

[0395] The snare loop 420 may further include features to provide a stronger grip on the valve clip 40. For example, as shown in the snare loop 420 shown in Figs. 114 and 115, a frictional coating or frictional sleeve may be disposed on a portion or the entirety of the snare loop. In another example, as shown in Fig. 117, a plurality of relatively small protrusions 426A (rounded ridges, sharp teeth, or similar shapes) may be disposed on a portion or the entirety of the radially inner surface / side of the snare loop 426. In another example, the snare loop may be constructed from a wire coil and may be configured in either a compressed configuration 428A (Fig. 118) or a longitudinally expanded configuration 428B (Fig. 119). This allows for various levels of texture to enhance the grip of the loop on the valve clip 40. These different loop shapes and frictional engagements may be mixed and matched with each other and with any of the embodiments described herein.

[0396] Although the snare catheter 401 and snare loop 420 have been described above as being used to grasp the valve clip 40, other uses are possible. For example, they may be used to image other tissues. It may be desirable to remove calcified nodules in the leaflets to facilitate valve placement. They may be used to capture and remove leaflet tissue to facilitate flow after insertion of a replacement valve. They may be used to remove chordae to facilitate valve movement. In this regard, the snare loop 420 may be used to grasp such tissue while the resection loop 404 resects it. However, it may be useful to provide the snare loop 420 with a resection element (e.g., an RF electrode) to initially assist in the resection of such tissue.

[0397] The snare catheter 401 may further comprise a tip member 422 at the distal end of the outer tubular sheath 416, as best shown in Figs. 120 and 121. The tip member 420 may be configured to maintain the snare loop 420 at a desired angle or orientation relative to the outer tubular sheath 416 and the valve clip 40. Because the valve clips 40 tend to have a generally conical or "V" shape, as previously indicated herein, a clamping snare loop may have a tendency to be squeezed out of the valve clip 40 as it is clamped. This tendency to slip off may be increased if the snare loop 420 is positioned at an elevation angle relative to the vertical axis of the valve clip 40. If the snare loop 420 exits the outer tubular member 416 from a distally facing opening (e.g., in the absence of the tip member 422), the angle of the snare loop 420 increases relative to the axis as it is retracted into the outer tubular sheath 416, and it may slip off the valve clip 40.

[0398] In contrast, the tip member 422 includes an opening 422A through its side wall and a beveled or curved surface 422B configured to guide the snare loop 420 emerging from the opening 422A at an angle generally perpendicular to the axis of the outer tubular sheath 416 and the axis of the valve clip 40.

[0399] Additionally, tip member 422 may feature to aid in engagement and / or friction with valve clip 40, which may allow snare loop 420 to clamp valve clip 40 against tip member 422 and prevent valve clip 40 from slipping off snare loop 420. In the example of Figures 120 and 121, the shape of opening 422A may have relatively sharp or steep corners around its periphery, which may be pressed into valve clip 40 to help maintain position.

[0400] In the example of FIG. 122, the proximal and distal channels 422C, 422D extend from the main opening 422A, providing additional areas of sharp or abrupt corners that extend a greater distance in the longitudinal direction. In the example of FIG. 123, the tip member 422 can include a number of ridges or grooves 422E in the surface of the tip member 422 adjacent the opening 422A and / or the channels 422C, 422D. These ridges or grooves 422E can be relatively linear and circumferentially oriented relative to the opening 422A and / or the channels 422C, 422D, or can have a different pattern, such as a wavy or zigzag pattern. In the example of FIG. 124, a number of spikes, hooks, or similar sharp shapes can extend from the sides or other nearby locations around the perimeter of the main opening 422A. Any combination of these engagement features can be used together to provide a surface that can better engage the valve clip 40 upon contact.

[0401] The snare catheter 401 may also include a handle 440 configured to controllably retract the internal control member 418 and, therefore, the snare loop 420. Specifically, the handle 440 allows for the application of a predetermined, limited amount of force to the snare loop 420 while allowing for the ability to lock the position or force of the snare loop 420 at a desired level. This allows for a relatively firm grip on the valve clip 40 without requiring sufficient force to damage the catheter 401, and this gripping force can be maintained throughout the entire procedure without having to hold much of the handle 440 while the procedure is being performed.

[0402] The handle 440 can have other possible mechanisms for controlling and locking the position / force of the snare loop 420. One example of such a mechanism is shown in Figures 125 and 126, which includes an outer housing 442 formed in a generally cylindrical shape and a knob 448 located at the proximal end of the housing 442 (i.e., to the right in the figures) configured to be proximally retracted from the housing 442. Retracting the knob 448 proximally also pulls the inner control member 418 proximally, retracting the snare loop 420 proximally into the opening in the tip 422.

[0403] The force applied to the knob 448 as it is pulled is limited or resisted by a spring 450 disposed in the housing 442. The spring 442 can be connected to either the internal control member 418 or the distal portion 440 of the knob 448 and inside the housing 442 such that the spring 450 can compress or expand to generate a stronger resistive force as the knob 448 is pulled proximally. Depending on the configuration of the spring 450 (e.g., size, amount of initial compression, spring constant, and similar aspects), the force applied by the spring 450 can be optimized to apply a predetermined constant tension over the length the knob 448 may be pulled or to increase the tension as the knob 448 is pulled further proximally.

[0404] The handle 440 may also include a locking mechanism capable of locking the position of the inner control member 418 relative to the housing 442 and the outer sheath 416. In this example, shown in FIGS. 125 and 126, the locking mechanism comprises a longitudinal groove 444 extending along at least a portion of the length of the housing 442. A tracking peg 446 is secured to the inner control member 418 and disposed at least partially within or through the groove 444. As the knob 448 is pulled back proximally, the tracking peg 446 moves along the length of the groove 444. Once the inner control member 418 reaches a desired position, the knob 448 can be rotated to move the tracking peg 446 transversely relative to the length of the groove 444 into one of a number of branched grooves. The branched grooves are preferably shaped to retain the position of the tracking peg 446, and therefore the position of the inner control member 444, when the user releases the knob 448. For example, the bifurcated groove may be angled somewhat distally such that the tracking peg 446 within the bifurcated groove is maintained by the distally directed force of the spring 450 to releasably lock the internal control member 418.

[0405] The handle 440 also includes a port 452 that communicates with the inner and outer sheaths 416 of the handle housing 442. The port 452 can be used to supply saline, contrast, or equivalent fluids during the procedure.

[0406] The handle 440 may also be electrically connected to an RF generator and the snare loop 420 (if the snare loop includes an RF electrode or similar cutting element) so as to provide energy to the resection snare 420 during the procedure. As previously mentioned, in some circumstances it may be useful for the snare loop 420 to include a cutting element to resect at least a portion of tissue surrounding the valve clip 40 or other heart valve treatment device so that the snare loop 420 may better engage the valve clip 40.

[0407] Generally, it is preferred that the same delivery catheter (e.g., steerable catheter 180) contain and deliver both the ablation and capture catheter 403 and the snare catheter 401. However, depending on the particular procedure, the ablation and capture catheter 403 and the snare catheter 401 may be delivered separately, either through separate delivery catheters or without the use of any overlying catheters.

[0408] 127-130 illustrate an exemplary technique using a removal system 400 including a resection and capture catheter 403 and a snare catheter 401. Although a specific removal system 401 is illustrated and described, variations of this procedure are contemplated, including the use of different embodiments described herein.

[0409] First, the delivery catheters (e.g., steerable delivery catheter 180), including the ablation and capture catheter 403 and the snare catheter 401, are advanced into the left atrium 12 of the patient's heart. Generally, it is desirable to advance the tip of the catheter 180 through the valve leaflets 22, 24 first into the left ventricle 14. This may be useful to prevent either the ablation and capture catheter 403 or the snare catheter 401 from becoming entangled with any of the chordae tendineae extending from adjacent the valve leaflets 22, 24. The basket tip 414 of the basket 102 may be positioned at or partially beyond the opening of the delivery catheter 180, which may be useful to provide a generally smooth surface that does not "catch" or get caught as it passes through the valve leaflets 22, 24 or nearby chordae tendineae.

[0410] Next, the resection / capture catheter 403 and the snare catheter 401 are advanced out of the catheter 180 into the left ventricle 14. In the initial stage, the opening 422A of the tip member 422 faces the valve clip 40. If the snare loop 420 is not yet deployed externally, the internal control member 418 is moved distally via the handle 440 to deploy and expand it. After the snare loop 420 is aligned with the valve clip 40, the snare catheter 401 is moved proximally so that the snare loop 420 surrounds the valve clip 40, as shown in FIG.

[0411] During this time, basket 102 and resection loop 404 may be either in a different position than snare loop 420 or in an opposite rotational position and / or may be positioned distally beyond snare loop 420 .

[0412] 128, the snare loop 420 is tightened or pinched around the valve clip 40 by the time the valve clip 40 is pressed against the tip member 422. This can be accomplished by retracting the inner control member 418 proximally via the handle 440 (e.g., by pulling back on the knob 448 to lock its position within the slot 444). If not already aligned, the resection loop 404 and basket 102 are vertically aligned with both the valve clip 40 and the snare catheter 401.

[0413] 129, the snare catheter 401 is advanced distally to create a counterforce that draws the valve clip 40 further into the left ventricle 14. The resection and capture catheter 403 is retracted proximally (concurrently or prior to the generation of the counterforce) to position the resection loop 404 on the atrial side of the valve clip 40, between the clip 40 and the valve leaflets 22, 24. The basket 102 is positioned partially or nearly completely around the valve clip 40 and the distal portion of the snare catheter 401 (e.g., snare loop 420 and distal end 422).

[0414] 130, both the clamping loop 106 and the resection loop 404 are clamped or contracted while maintaining the opposing force from the snare catheter 401. As previously described, this opposing force allows for good contact between the electrode of the resection loop 404 and the leaflet tissue. Thus, when the electrode of the snare loop 404 is activated, a quick and clean cut can be made through the tissue and the valve clip 40 is completely removed and captured in the basket 102. Finally, the resection and capture catheter 403 and the snare catheter 401 are at least partially retracted back into the delivery catheter 180 and removed from the patient. When the resection and capture catheter 403 and the snare catheter 401 are retracted back into the delivery catheter 180, the distal end / opening of the delivery catheter 180 may remain in the left atrium 12 or may be retracted back into the left ventricle 14.

[0415] In a scenario where the ablation and capture catheter 403 and snare catheter 401 are retracted after the delivery catheter 180 has been returned to the left ventricle 14, the valve chordae tendineae may get in the way of the delivery catheter 180 as it is returned to the left ventricle 14. For example, the distal end of the delivery catheter 180 may not be sufficiently tapered and may "get caught" by the chordae tendineae.

[0416] One solution to this problem is to provide a chordae dilator that can be positioned partially into the distal opening of the delivery catheter 180 as it passes through the leaflets 22, 24 and chordae. Such a chordae dilator can have a tapered and / or sloped distal surface and can be sized radially to include most or all of the opening in the delivery catheter 180.

[0417] An example of a chordae dilator 432 can be seen best in FIGS. 134-137. In this embodiment, the chordae dilator 432 includes a body having a bottom surface 432D with a bias angle (i.e., edges that form an angle, such as about 45 degrees, with respect to the vertical axis of the dilator 432). Additionally, the bottom surface 432D may be rounded or slightly conical to facilitate easier transition into the delivery catheter 180. Optionally, the chordae dilator 432 may have a similarly shaped top surface 432C, which may be useful in distracting the chordae in both directions for either the mitral or tricuspid valves.

[0418] The chordae dilator 432 has two passages 432A, 432B, one passage 432A for receiving the snare catheter 401 and the other 432B for receiving the cutting and capture catheter 403. Alternatively, the chordae dilator 432 may have only a single passage for receiving only the snare catheter 401 or the cutting and capture catheter 403. In either case, it is preferable that each catheter in the passage is rotatable during the procedure. Furthermore, one of the passages may have a "C" shape (i.e., a shape that does not completely surround the catheter) so that one of the catheters can be separated from the chordae dilator 432. If desired, the chordae dilator 432 may include one, two, or even more radiopaque markers 432E. For example, the radiopaque markers 432E may be located on circumferentially opposing sides of the chordae dilator 432 and may extend at least partially between the proximal and distal ends of the chordae dilator 432.

[0419] When the user wishes to move the delivery catheter 180 into the left ventricle to capture the snare catheter 401 and / or the ablation and capture catheter 403, the snare catheter 401 and / or the ablation and capture catheter 403 are moved relative to the delivery catheter 180 to partially position the chordae tendineae dilator 432 in the distal opening of the delivery catheter 180, similar to that shown in FIG. 135. The delivery catheter 180, snare catheter 401, and ablation and capture catheter 403 are then all advanced distally until the distal end of the delivery catheter 180 is located within the left ventricle 14.

[0420] Alternatively, the chordae dilator 432 may be configured only to be connected to the snare catheter 401 and the resection and capture catheter 403 without having a specific surface for chordae dilation. In this regard, the chordae dilator 432 need not be used for chordae dilation applications, but is used primarily to keep the two catheters parallel, which is useful for achieving the desired alignment while the procedure is being performed.

[0421] The chordae dilator 432 may alternatively comprise three passages. For example, one passage 432A accommodates the snare catheter 401, another passage 432B accommodates the resection / capture catheter 403, and one facilitates the passage of a guidewire. The chordae dilator 432 may also be used to provide relative axial alignment of the snare, resection loop, and basket. The position of the other members relative to the chordae dilator 432 changes the length of the free member arm, thereby controlling the distance between the members and the angle of the member axes.

[0422] Although the snare catheter 401 has been described above as being used to grasp the valve clip 40, other uses are possible, such as for example, being used to grab or capture a guidewire or Fogarty Balloon while a procedure is being performed (e.g., a Transapical Approach is being performed), which is useful for pulling these components through the targeted valve and preventing them from becoming tangled or stuck.

[0423] The removal system 400 has been described above as being delivered through a transeptal guide catheter 182 or a similar catheter. However, the removal system 400 may be further configured to have a guidewire path or passageway such that it may be delivered over a guidewire 430. The guidewire may provide a more delicate force and stiffness transition to the tissue when delivering the removal system, ensuring safe introduction into various anatomical structures. FIGS. 131-133 show an example of a removal system 400 having such a guidewire passageway. Specifically, the guidewire passageway extends from a proximal opening into the outer sheath 416 of the snare catheter 401, through an opening in the distal end member 422, through the basket 102, and finally through a passageway in the basket tip 414.

[0424] Other paths are also possible for the guidewire 430. For example, FIG. 138A shows the guidewire 430 extending outside the basket 405 and into a passageway that opens near the exterior top and bottom of the basket tip 415 to allow passage of the guidewire 430. In this example, the guidewire 430 does not pass inside the basket 405. Alternatively, the guidewire 430 may pass through one of the meshes of the basket 405, enter an interior opening to a passageway in the basket tip 415, and extend distally from the basket tip 415, as in FIG. 138B.

[0425] Guidewire 430 may extend proximally only through steerable catheter 180, as shown in FIGURE 138A, or may extend proximally through a passageway in either snare catheter 401 or ablation and capture catheter 403. Alternatively, guidewire 430 may extend proximally outside of all of steerable catheter 180, snare catheter 401, or ablation and capture catheter 403, except for basket tip 415, as shown in FIGURE 138B.

[0426] Alternatively, as shown in FIG. 139, the basket tip 415 may include a guidewire-like pigtail or curved wire 431 attached and extending distally from the tip 417 to aid in passing through the valve and avoid traumatizing different structures of the heart.

[0427] Using a guidewire 430 to deliver the removal system 400 may facilitate passage through valves with smaller openings, which are particularly common in valves with multiple valve clips 40 implanted. Traveling over the guidewire 430 may facilitate easier removal of the two valve clips 40. For example, a catheter with a resection loop 420 may be delivered over the guidewire 430 and used to resect the leaflet tissue between the two valve clips 40, thereby moving the clips 40 apart from each other before they can be captured sequentially via the successive removal systems 400.

[0428] For sequential removal, the procedure may include placing a steerable catheter 180 in the left atrium, moving a guidewire 430 through the target opening in the valve, feeding a resection and capture catheter 403 over the guidewire 430, removing the guidewire 430, resecting and removing the valve clip 40 with the resection and capture catheter 403, removing the resection and capture catheter 403, again moving the guidewire 430 through the target opening in the valve, and repeating the removal process. The steerable catheter 180 may be left in place after removal of the first valve clip 40 if it is of sufficient size to completely remove the valve clip 40, or the steerable catheter 180 may be removed and a second steerable catheter 180 may be placed.

[0429] Additionally, in some embodiments and procedures, the resection and capture catheter 403 desirably includes a basket 460 that is expandable or extendable from a longitudinally compressed configuration, thereby allowing the same sized basket 460 to accommodate different sized valve clips 40 without requiring multiple different sized baskets, and allowing the snare catheter 401 to "cover" the valve clips 40. For example, FIG. 140 illustrates the basket 460 in a longitudinally compressed configuration, and FIG. 141 illustrates the basket 460 in an expanded configuration.

[0430] The longitudinally expandable feature of the basket 460 can be achieved in a number of different ways. For example, the basket 460 can be braided or woven from one or more wires of a shape memory material (e.g., Nitinol) and then heat set into a compressed configuration (FIG. 140). Instead of or in addition to heat setting, the braid pattern can be configured to generally bias or at least encourage the basket 460 into the compressed configuration. Alternatively or additionally, the basket 460 can include a longitudinally elastic tether or elastic outer cover, which can bias the basket 460 into the compressed configuration. Alternatively, the wires of the basket 460 can be constructed of a stretchable elastic material. In an alternative embodiment, one or more of the struts / wires of the basket 460 can be coiled to form a spring. In yet another alternative embodiment, a number of pull wires connected to the basket 460 and to the proximal end of the device closer to the user may maintain the basket 460 in a compressed configuration and may be released as appropriate to allow the basket 460 to increase in diameter and / or length proximally.

[0431] The baskets described herein (e.g., basket 102 or 460) have been shown as having a generally cylindrical expanded shape. However, other basket shapes are possible. For example, FIG. 143A shows basket 102' having a generally conical shape. By way of example, the expanded basket shape tapers from about 30 mm to about 6 mm. When partially positioned outside of steerable catheter 180, as shown in FIG. 143B, the tapered shape forms an atraumatic, smooth shape without large edges. This prevents steerable catheter 180 from getting stuck or jammed as it passes through valves, leaflets, and chordae tendineae. This shape also allows the basket to be more easily loaded by steerable catheter 180 or other catheters.

[0432] While it is desirable to include a basket 102 to capture the valve clip 40 or other heart valve treatment, the basket 102 can be omitted from the resection and capture catheter 403 as shown in FIGURE 144. In such a device, the snare loop 420 (and possible clip engagement features described above) can be used to grasp the valve clip 40 as the resection loop 404 moves proximally over the clip 40 and snare loop 420 and is activated to resect the desired valve tissue. The snare loop 420 maintains its grip on the valve clip 40 and allows the clip 40 to be withdrawn proximally from the patient.

[0433] Described herein are applications of one or more snare loops of a snare catheter that may be used in connection with the removal of various cardiac valve treatments (e.g., valve clips). When using a snare loop with a resection loop (e.g., any of the techniques described herein), there is a risk that the snare loop or other components of the snare catheter may contact or move in close proximity to an active electrode on the resection loop. Generally, metal or conductive surfaces in close proximity to an active RF electrode may cause direct coupling (e.g., arcing between the active electrode and a conductive object). Unintended arcing may be undesirable as it may damage parts of the snare catheter or snare loop or damage tissue in unintended areas. Existing snares are generally not intended for use in close proximity to RF ablation elements and often have exposed metal or conductive material.

[0434] Thus, it may be desirable for the snare loop and other components of the snare catheter to be insulated and electrically isolated from other conductive components to which the loop is connected. For example, electrical insulation may be provided on one or all of the wires of the snare loop itself, the inner control member, the inner and / or outer surface of the outer sheath, and the inner and / or outer surface of the distal tip of the outer sheath. For example, the electrical insulation may be entirely made of a non-conductive material such as silicone, polyimide, a dielectric coating, PTFE (e.g., heat shrink tubing), FEP, or similar biocompatible non-conductive material, or may have one or more non-conductive layers or coatings. As a specific example, the snare loop may be constructed of one or more Nitinol wires insulated via a silicone tube, a dielectric coating, a braided polymer tube (e.g., polyimide), or a coiled polymer tube (e.g., polyimide or polyolefin). This allows current (e.g., RF current) to be prevented from flowing through the conductive material underlying the loop wire (e.g., Nitinol, 304, stainless steel, or similar moldable material) during the procedure.

[0435] 147-152 show an exemplary embodiment of a snare catheter 500 that includes electrical insulation to electrically isolate the snare loop 502 when it is in close proximity to or in contact with the resection loop. This prevents damage to the snare loop 502, other components, and non-target areas of tissue. The structure of the snare catheter 500 in use is generally similar to that previously described herein. For example, the snare loop 502 may be located at the distal portion of the snare catheter 500 and connected to an internal control member 418, which may allow a user to increase or decrease the size of the loop 502 outside of the outer tubular jacket or sheath 416 and distal end member 508. Size adjustment may be provided by a user via a proximal handle 514 having a movable interface element (e.g., a slidable tab) that moves the internal control member 418 longitudinally within the outer tubular jacket 416.

[0436] In this example, snare loop 502 has a saddle shape as previously described, but may be any shape or configuration described elsewhere herein. The loop may include features that allow visualization in medical imaging. For example, the loop may include a radiopaque material in part or in its entirety. As a specific example, the loop and / or other locations (e.g., a radiopaque tube or sleeve disposed on the nitinol wire forming loop 502) may include discrete radiopaque markers 504 at the tip. As another example, radiopaque wire may be braided, twisted, coiled, or otherwise incorporated into the nitinol wire forming loop 502.

[0437] As previously mentioned, the snare loop may include a coating, layer, or tube disposed over some or all of the underlying snare wire (e.g., a shape memory material such as Nitinol, stainless steel, or a radiopaque material as described herein). The coating, layer, or tube may include silicone, polyimide, a dielectric material (e.g., polyolefin), PTFE (e.g., heat shrink tubing), FEP, or similar biocompatible non-conductive materials. Specifically, the coating of the underlying snare loop 502 may be comprised of silicone tubing, a dielectric coating, a braided polymer tubing (e.g., polyimide), a coiled polymer tubing (e.g., polyimide). The inner control member 418 and its connection point with the snare loop 502 may also be partially or fully insulated with similar materials.

[0438] The snare catheter 500 may also have a distal end member 508 that includes an open area leading to one or more openings 510 (e.g., one or two openings) through which the snare loop 502 partially exits. These openings 510 may be located in the sidewall of the distal end member 508 as shown, or a single opening may be located at the distal, axial (does that mean distal?) end. The distal end member 508 may have an atraumatic distal tip, such as a rounded or spherical tip member as shown.

[0439] The distal end member 508 (i.e., its material of construction) may be constructed of a non-conductive material such as a polymer, or alternatively, the distal end member 508 may be constructed at least partially or entirely of a conductive metal coated with a non-conductive material as previously described.

[0440] The distal end member 508 may also have a molding or insert 512 of non-conductive material, as previously described, at least partially within the cavity or passageway of the distal end member 508 (FIG. 149). Additionally, the insert 512 may be disposed on the edge of each opening to help prevent sharp edges around the opening 510 from scraping away the insulating layer of the snare loop 502 as the snare loop 502 moves in and out of the distal end member 508. For example, the insert 512 may form a rounded, curved, or blunt shape around the edge of the opening 510. Alternatively, if the distal end member 508 has rounded or blunt edges around the opening 510 and is entirely constructed of a non-conductive material or has a non-conductive exterior coating, the insert 512 may not be necessary.

[0441] As described elsewhere herein, it may be useful for the snare loop 502 to move out of the snare catheter 500 (e.g., the distal end member 508) in a generally transverse trajectory relative to the axis of the snare catheter 500. The side exit point and generally concave shape of the snare loop 502 opening proximally may be useful in maintaining a relatively constant proximal / distal position of the captured heart valve treatment device relative to the snare catheter 500 as the snare loop 502 is tightened to move the heart valve treatment device closer to the distal end. Maintaining this constant proximal / distal position may be important to grip the heart valve treatment device in a more "atrial" position (i.e., closer to the leaflets). In general, the more "atrial" the position of the snare loop 502 gripping the heart valve treatment device, the more stable and secure the grip of the snare loop 502 will be throughout the procedure.

[0442] Unlike the distal end member 422 of FIG. 115 described above, the distal end member 508 has a vertical or axially parallel bar 511 or structural feature that separates the two openings 510. This vertical bar 511 reduces the likelihood of damage to the snare loop 502 (e.g., deformation of the loop 502 and / or removal of the insulating coating) that may occur as the snare loop 502 is fully retracted into the distal end member 508. Due to the relatively large diameter wire used in the snare loop 502 and the need to maintain a relatively small overall diameter / profile of the snare catheter, depending on the size of these components, the snare loop wire may become deformed or damaged when fully retracted into the distal end member 508.

[0443] 153 and 154 show an alternative embodiment of a distal end member 516 having a single opening, a lower beveled surface, and a cylindrical central bar 518 that can be inserted into the distal end member 516 during manufacture. Again, this central bar 518 can be useful in preventing the snare loop 502 from being completely pulled into and damaged by the distal end member 516. All of these components may be constructed entirely of or coated with a non-conductive material.

[0444] During the procedure, several factors may apply forces to the snare loop, which may cause the snare loop to bend and make it difficult to capture the heart valve treatment device. For example, the patient's heartbeat, blood flow, the presence of chordae tendineae, movement of the valve leaflets, and movement of the heart valve treatment device itself may cause the snare loop to bend, rotate, twist, or similarly move undesirably. In this regard, it is desirable for the snare loop to have a stiffness that limits damage or bending and reduces bending as the snare loop is pulled into the snare catheter. Specifically, it is desirable for the snare loop to have a stiffness that reduces or substantially prevents bending, rotation, twisting (e.g., bending proximally or distally relative to the snare catheter shaft) about the snare catheter shaft, or twisting / twisting of the snare loop relative to the snare catheter shaft. For example, the snare loop may have a stiffness that is at least sufficient to prevent bending due to blood flow through the heart. In another example, the snare loop may be stiff enough to deflect the notochordal tendons and / or push around the heart valve clip and valve tissue to optimize its ability to capture the heart valve clip.

[0445] It should be noted that in the following examples, the forces exerted on the snare loop are described in terms of mass (e.g., grams) exerted under standard gravity. One of ordinary skill in the art would be able to convert these values ​​into force values. In the following examples, it is assumed that the wire diameter of the underlying snare loop is in the range of about 0.001 inches or more and about 0.030 inches or less. In the following examples, it is assumed that the snare loop shape has a working diameter (i.e., unconstrained expanded diameter) in the range of about .100 inches or more and about 1.5 inches or less. As an example, the snare loop is configured to limit the deflection (proximal or distal) of the snare loop distal end to a range of about 0 mm or more and about 10 mm or less when a force in the range of about 0 grams or more and about 3 grams or less is applied to the snare loop (e.g., distal end). As a specific example, the snare loop is configured to limit the deflection (proximal or distal) of the snare loop distal end to a range of about 0 mm or more and about 5 mm or less when a force in the range of about 0 grams or more and about 2 grams or less is applied to the snare loop (e.g., distal end). As another specific example, the snare loop is configured to limit the deflection (proximal or distal) of the snare loop distal end to a range of about 0 mm or more and about 2 mm or less when a force in the range of about 0 grams or more and about 2 grams or less is applied to the snare loop (e.g., distal end). As a further specific example, the snare loop is configured to limit the deflection (proximal or distal) of the snare loop distal end to a range of about 0 mm or more and about 2 mm or less when a force in the range of about 0 grams or more and about 2 grams or less is applied to the snare loop (e.g., distal end). As yet another specific example, the snare loop is configured to have a distal end deflection of about 1 mm for a weight of about 0.75 grams, a deflection of about 1 mm for a weight of about 1.125 grams, a deflection of about 2 mm for a weight of about 1.5 grams, and a deflection of about 2 mm for a weight of about 1.875 grams ("about" refers to a range of ±15%). Note that the above examples of stiffness, underlying wire size, and working loop diameter of the snare loop may also be applied to the resection loop and the clamping loop of the capture basket described elsewhere herein.

[0446] In general, there are several different ways to construct a snare loop that is relatively stiff and does not flex (e.g., within the range of the examples discussed above) or twist during a procedure. As one example, the snare loop may be formed of a solid wire (e.g., Nitinol) as opposed to a braided, stranded, or twisted wire. As another example, the snare loop may be formed of a wire with an exterior coating (e.g., a metal or polymer coating). A solid, braided, stranded, or twisted Nitinol wire may be coated with stainless steel, a polymer, or a radiopaque material such as gold, platinum, or tantalum. Thus, the snare loop may use a drawn filled tubing (DFT). As another example, multiple wires may be used that are positioned adjacent to one another. As another example, a braided reinforcement tube or wire (i.e., a tube or wire with an outer layer of braided wire) may be used. As another example, the cross-sectional shape may be square or rectangular.

[0447] 155 shows an example of a snare loop 502 connected to an internal control member 418 (e.g., a core wire) that may provide a desired level of resistance or stiffness to deflection during a procedure. The snare loop 502 may be constructed of a solid shape memory wire (e.g., Nitinol wire) having a diameter ranging from about 0.001 inches or more to about 0.03 inches or less. The Nitinol wire may include one or more radiopaque markers (e.g., a radiopaque coil or sleeve at the tip or sides, or a radiopaque coating on the Nitinol wire). Additionally, a marker edge coating may be placed on both the shape memory wire and the radiopaque marker.

[0448] The proximal end of the shape memory wire may be connected to the inner control member 418 via distal crimp 505A (e.g., a metal sleeve crimped to other components). The distal region of the inner control member 418 may include a polymer heat shrink tubing 507 that may provide stiffness and electrically insulate the inner control member 418 from a resection loop used nearby. The heat shrink tubing 507 may be further connected to the inner control member 418 via distal crimp 505A and proximal crimp 505B.

[0449] The snare loop may also include a sharpened distal end to facilitate threading of the chordae during the procedure. For example, snare loop 502 of FIG. 148 has a rounded tip, but may have a steeper angled tip. For example, it is preferred that the two regions of the snare loop form a distal tip that meets within an angle range (rounded or steep) of about 80 degrees or more and about 130 degrees or less. Alternatively, the snare loop may have a protruding feature (e.g., a spherical, cubic, triangular, pyramidal, or elongated shape) that extends outward from the distal portion of the distal end.

[0450] Specifically described herein are resection loops for resection of tissue within a patient's vasculature, for example during procedures to remove heart valve repair. It is noted that the term "resection loop" is broadly defined herein to include complete loops, partial loops, and any curved shape. Additionally, the resection loops described herein may be used to resect chordae and / or heart / valve tissue. The resection loops may be used alone as part of a separate resection loop catheter or may be used with other devices described herein, such as capture baskets. For example, they may be combined into a single tool or used together as separate tools. Additionally, the resection loops herein may have the same size and particularly stiffness level as described above for the snare loop, such that bending or kinking of the resection loop is minimized or prevented based at least on the blood flow and blood pressure within the heart.

[0451] In some applications, it is desirable to provide a relatively high RF power (e.g., in the range of about 5 watts or more and 1600 watts or less) to the resection loop to better ablate the target tissue. However, such high RF power may cause an increase in temperature and damage portions of the resection loop in some circumstances (e.g., not fully embedded in tissue and partially or fully exposed to blood). Among other damage, since the resection loop is primarily made of a shape-memory material such as Nitinol, the high temperature may change any heat-set shape imparted to the material. Such damage may inhibit or hinder the resection and may make it more difficult to remove the resection loop from the patient. It is therefore desirable to improve the delivery of high RF power by imparting a predetermined material and / or shape to the electrodes. These techniques may be used with any of the resection loops or resection devices described herein.

[0452] Regarding materials first, the electrodes of the resection loop are desirably constructed of a material that can withstand high temperatures without damage. In this case, materials that do not have shape memory properties, such as stainless steel or similar metals, may be used. For example, the resection loop may be formed of one or more wire segments of shape memory wire (e.g., Nitinol) adjacent to a segment of non-shape memory wire (e.g., stainless steel). Alternatively, a non-shape memory tube or sleeve may be connected (e.g., swaged, welded, glued, etc.) to the shape memory wire (e.g., Nitinol) to form the electrode. The shape memory wire segments may include an electrically insulating outer layer such that only the non-shape memory portions are exposed to form the electrode.

[0453] One exemplary embodiment of such a configuration is shown in Figures 156 and 157, in which a resection loop 520 has a main loop segment 524 formed from a shape memory wire section and one or more electrodes 522 that are partially or entirely made from a non-shape memory material (e.g., a stainless steel wire segment or sleeve). An electrically insulating layer 525 is disposed over at least the main loop segment 524, and may optionally be disposed over a portion of the electrodes 522. Although only a single electrode 522 is shown, multiple electrodes and multiple segments may be provided.

[0454] Next, the shape of the resection loop electrode will be described, which may be useful in reducing damage to components of the resection loop, such as shape memory wires and electrical insulators. Applicant has found that electrodes with sharp edges, edges, raised surfaces, or similar features may concentrate electrical loss areas. In this regard, electrodes with such features may be useful in maintaining the temperature of the non-electrode portion of the loop at a more desirable level to avoid damage, since less RF power is required compared to electrodes without such features. Thus, such electrodes may have a larger diameter and shape as specified herein relative to adjacent main loop segments. Electrode shapes include, for example, cylindrical, spherical, cubic, curved, ridged, and similar variations and combinations (e.g., cylindrical with ridges). These electrode shapes may be used in conjunction with any of the other electrode or resection loop features described herein. Furthermore, when multiple electrodes are present, all of the electrodes may be the same shape or may be different shapes. Additionally, the electrode shape may extend evenly or uniformly around the circumference of the electrode, or may extend from only a portion of the electrode (eg, from the inside or outside of a loop).

[0455] 158-160 show one example of a resection loop 526 that is generally similar to the previously described resection loop 520, except that the electrode 528 has a generally cylindrical shape that is thicker or raised over the surrounding portion of the main loop segment 524 and insulating layer 525. The electrode 528 may be constructed as a separate segment (e.g., stainless steel) connected to the wire of the main loop segment 524, as shown in cross section in FIG. 160, or it may be constructed as a sleeve that partially or completely surrounds the underlying shape memory wire of the resection loop 526.

[0456] FIG. 161 shows another example shape of electrode 530, which has a relatively spherical or rounded shape and is elevated relative to the area adjacent the resection loop.

[0457] 162 shows a generally cylindrical electrode 532 connected to two adjacent ends of the main loop segment 524. To enhance the connection to the main loop segment 524, the electrode 532 may form a cylindrical wire-shaped cavity at either end sized to allow the main loop segment 524 and optionally the insulating layer 525 to fit within and be connected (e.g., glued, welded, etc.) therein.

[0458] The electrode 534 shown in Fig. 163 is similar to the cylindrical electrode 532, but its outer surface is rounded and higher in the middle than at either end. In other words, the electrode 534 tapers to a smaller radial diameter from its center to each end.

[0459] FIG 164 illustrates an electrode 536 having a generally cylindrical shape with a central ridge extending partially or completely around the circumference of the electrode 536. In this example, the electrode 536 is connected around the main loop segment 524, and an insulating layer is disposed on one or more end portions of the electrode 536. Alternatively, the insulating layer 525 may not be disposed on the electrode, such as the electrode 538 shown in FIG 165.

[0460] FIG. 166 shows an electrode 540 that is similar to electrodes 536, 538, but has a relatively wide cylindrical ridge in its center.

[0461] In another example, the electrode may be a wire spaced apart from the main loop segment 524 and the insulator 525 along most of its length. FIG. 167 shows one example of such a resection loop 542, where the wire electrode 544 is connected at both ends to the resection loop 542 such that the wire electrode 544 is partially or completely spaced apart from the resection loop 542, thereby forming a space or gap. In this example, the ends of the wire electrode 544 are connected at locations on either side of a mid-end or point of the resection loop 542, although they may be connected at other locations (e.g., along only one side of the resection loop 542).

[0462] As previously described herein, a resection loop may include multiple electrodes. For example, a resection loop catheter 541 is shown in FIGS. 168-170 having a distal resection loop 546 including multiple electrodes 548 (e.g., of any shape or configuration described herein). In this example, a first electrode 548A is located at the central and most distal location of the resection loop 542, and a second electrode 548B and a third electrode 548C are located on either side of the first electrode 548A and on the distal half of the resection loop 542. FIG. 171 shows a similar resection loop 545 without a central electrode and with a first electrode 547A and a second electrode 547B on either lateral side of the distal half of the resection loop 545. Reference numerals 549A and 549B indicate optional additional electrodes or alternative locations for the electrodes.

[0463] Monopolar RF may be used to power these resection loops with multiple electrodes (as well as the single electrode embodiments). In this example, each of the multiple electrodes may be connected to the same electrical circuit and activated simultaneously. For example, each electrode may be connected to a shape memory wire underlying the resection loop, which is connected to an internal control member (or separate electrical wiring) that is connected to an RF power source near the proximal end of the resection loop catheter.

[0464] Alternatively, all or some of the electrodes may be on separate circuits from one another so that they can be individually activated by the RF power source. Thus, additional electrical wiring may be provided underneath the insulating layer 525 and connected to one or more of the electrodes. This allows a user to activate some or all of the electrodes via the RF power source, as described later in this specification. Additionally, electrode impedance may be measured by the RF power source, which is useful for determining whether the electrodes are in contact with tissue or blood.

[0465] Although the resection loops described herein are primarily contemplated as being in a closed loop configuration, other configurations are possible. For example, they may be open loop, partially spiral, and the like. FIG. 172 shows an example of a resection loop device 556 having a hook, "C" or open loop shape 558. The curved shape may be substantially in a single plane or may be a non-planar spiral shape. The inner surface 558A may include one or more electrodes, the outer surface may include one or more electrodes, or electrodes may encompass both the inner and outer surfaces. This shape may be particularly useful for resecting chordae in addition to resecting tissue to release a cardiac valve treatment device.

[0466] Whether using a full loop configuration, the hook configuration previously described, or other chordae resection devices described herein, several different approaches are possible to access and resect the chordae of the mitral valve. For example, a trans-aortic approach to the mitral valve may be used. A trans-apical approach to the mitral valve may also be possible. A trans-atrial approach to the mitral valve may also be possible. If desired, a snare and / or capture basket may be used after the desired resection has been made.

[0467] The resection loops described herein, including those most recently described with reference to Figures 156-168, may be a single catheter device with a capture basket, as shown particularly in Figures 9-11, or 105, or may be a stand-alone resection loop catheter connected to an internal control member (e.g., a control wire) within a sheath, similar to the snare catheters described herein. The latter configuration allows a user to use different resection loop configurations in a procedure and / or to use a resection loop catheter separate from the capture basket catheter. That is, the resection loop catheter, capture basket catheter, and / or snare catheter can be used individually as needed.

[0468] Additionally, it is contemplated that a procedure may require only the use of a resection loop or a chordae resection tool, in which case the above-mentioned "standalone" resection loop catheter may be used. For example, the resection loop of the resection catheter may be used as both a resection loop and a snare loop. The resection loop may be advanced toward the patient's heart to resect (chordae and / or leaflet tissue). The resection loop may be placed and tightened around a cardiac valve treatment device (e.g., a valve clip) and, if necessary, the electrodes of the resection loop may be activated to resect any remaining tissue that requires resection and completely free the cardiac valve treatment device. The resection loop may then be used to remove the cardiac valve treatment device.

[0469] The resection loop and similar electrical ablation mechanisms described herein may have one or more electrodes forming a circuit connectable to an RF power source. Such electrodes may come into contact with blood and tissue to varying degrees in the cardiac environment, which may complicate tissue ablation. Applicants have found that the desired ablation of tissue may require the electrodes of the resection loop or similar device to generate a spark or plasma within the heart. Applicants have also found that the generation of said plasma and subsequent ablation of tissue may be facilitated by using RF power within a certain range, specifically within a range of about 5 watts or more and up to 1600 watts or less, and by using electrodes having specific areas. It should be noted that while adding more electrodes on the same electrical circuit requires proportionately more power (or individual generators for each electrode), individually activating certain electrodes among multiple electrodes all on different electrical circuits limits the power required.

[0470] For example, the surface area of ​​a single electrode may be in the range of about 0.003 to about 0.006 square inches. In another example, the surface area of ​​a single electrode may be in the range of about 0.003 to about 0.030 square inches. In another example, the surface area of ​​a single electrode may be in the range of about 0.004 to about 0.005 square inches. As a specific example, the surface area of ​​a single electrode may be about 0.00437506 square inches. A resection loop having multiple electrodes may have a similar value for each electrode that is part of the resection loop (e.g., 0.00437506 multiplied by the number of electrodes). The electrode area may include all exposed surfaces, including horizontal and vertical surface areas.

[0471] Described herein are various capture baskets used for capture and removal of heart valve treatment devices. As previously mentioned, the patient's heartbeat can cause movement of the valve leaflets, chordae tendineae, heart valve treatment devices, etc. This movement can cause the capture basket (and other components) to move or bounce within the patient's heart. Therefore, it can be useful to limit the freedom of movement of the capture basket in the deployed or expanded state.

[0472] For example, it may be useful to provide multiple connection points to the basket catheter (e.g., at the tip of the basket catheter) along the length of the basket. As a specific example, the catheter may be connected near a first, most distal location (e.g., at the fastening loop) and at a second, more distal location (e.g., at a portion of the wire further distal to the basket). Alternatively, the exit opening of the basket fastening loop may be located proximal to the tip of the catheter such that the tip of the catheter extends distally alongside the basket (e.g., 2-10 mm), thereby acting as a one-way stop to prevent the basket from rotating about the tip of the catheter.

[0473] For example, Figures 173-175 show various embodiments of a capture basket catheter 550 having multiple connection points to the capture basket 102. The present capture basket catheter 500 is described as including only a capture basket 102 and may be used in conjunction with other components described herein, such as a snare catheter or a resection loop catheter. However, a resection loop may also be incorporated into the catheter 550, as described in other embodiments herein.

[0474] The capture basket catheter 550 comprises at least one elongated catheter body having an internal lumen through which the fastening loops 106 are disposed, allowing a user at the proximal end of the catheter 550 to pull and fasten the basket 102 closed.

[0475] The distal portion of the catheter 550 may have a distal end member 552 that aids in connecting the basket to two axial or longitudinal locations of the catheter 550. Specifically, the distal end member 554 may have one or more (e.g., two) openings 552A at a first axial location (i.e., a first length from the distal end of the distal end member 552A). The wire of the fastening loop 106 may enter the lumen of the catheter body 554 through one or more openings 552A (e.g., if there are two openings, a portion of the wire may pass through one opening and a second portion of the wire may pass through the second opening).

[0476] Distal tip member 554 may also have a second connection point located distal to opening 552A. The second connection point may be one or more (e.g., two) openings 552B through which wires of basket 102 pass, and a separate connection member, such as a wire or tie, may be connected, tied, welded, glued, or otherwise connected to a portion of basket 102 and distal end member 554 through openings 552B. Alternatively, distal tip member 554 may be welded or glued directly to the wires of basket 102, or a more distal portion of distal tip member 554 may be unconnected and instead act as a one-way stop to prevent the basket from rotating past the axis of basket catheter 550.

[0477] As previously discussed, in some circumstances it may be desirable to use separate catheters for each of the resection loop, snare loop, and capture basket, or to use a single catheter that includes multiple components (e.g., a resection loop and a capture basket). In this regard, FIGS. 176-179 show a delivery sheath 580 that aids in the delivery and / or switching between multiple catheter devices. In general, the delivery sheath may have an elongated tubular portion 581 having a sheath lumen connected to a hub 582. The hub 582 serves as an entrance for the elongated tubular portion 581 for multiple catheters during a procedure.

[0478] The hub 582 may include multiple ports that open into an interior cavity 590 formed by the housing of the hub 582. The hub 582 may include two, three, four, five, six, or more ports. In this example, the hub 582 may include three ports 584, 588, 586 that open at various angles to one another at the proximal end of the hub 582.

[0479] Cavity 590 may be tapered or may have a reduced width distally toward elongated tubular portion 581, allowing multiple catheters to converge and enter the lumen of elongated tubular portion 581. By way of example, cavity 590 has a generally triangular shape. To further aid in convergence into elongated tubular portion 581, a funnel 591 may be provided at the distal end of cavity 590. Funnel 591 may have a passageway of reduced width and may have a generally elliptical cross-sectional shape, the width of which generally matches the width of the triangle of cavity 590. Funnel 591 may be a separate component from the housing that defines cavity 590, or may be an integral part of the housing component that defines cavity 590.

[0480] Ports 589 (FIG. 176) may further be provided accessible within cavity 590 for removing air during a procedure and / or for connection to an infusion line for fluids, the ports being positioned such that when the ports are facing upward, air within cavity 590 will rise toward the ports 589 to facilitate removal of the air. Any or all of the ports may be provided with a valve, such as a hemostatic valve, to close the port when not in use or around a catheter when the catheter is being passed through. FIG. 179 shows a delivery sheath for use with the three individual catheters 550, 500, 541 previously described herein.

[0481] It may also be desirable to use a loading tool, such as loading tool 592 shown in FIG. 178, to load catheters and guidewires into hub 582 and to facilitate easy exchange of these tools within the patient's body, particularly during a procedure. By way of example, loading tool 592 may have an elongated tubular portion, optionally tapered at its distal end, and may further have a valve, such as a hemostatic valve, at its proximal end. Some ports, such as ports 584 and 586, may be relatively larger than other ports to accommodate larger diameter loading tools during a procedure, while other ports, such as port 588, may be relatively smaller (e.g., may have a locking Tuey-Borst valve), that are not intended for use or exchange of loading tools during a procedure. Loading tool 592 may also have a releasable locking mechanism for engaging a catheter therein, thereby maintaining the position of the catheter within the patient during a procedure.

[0482] The capture basket catheter is primarily oriented to open proximally relative to the user and the catheter, as previously described. However, depending on the approach to the patient's heart, a distally opening basket may be desirable. For example, FIG. 180 shows a capture basket catheter 556 having a distally opening basket 102. The proximal end of the basket 102 may be connected to an elongated catheter or sheath 557, and the snare catheter 500 and resection loop catheter 541 may be positioned alongside or through a central channel of the capture basket catheter 556. In either case, features may be provided to reduce the likelihood of chipping of electrical insulation on the snare catheter and / or the resection catheter. For example, the basket 102 may have a coating to reduce abrasion and / or to round / reduce sharp edges. If desired, the basket 102 may also have a fastening loop 106 for closing the basket 102, similar to those previously described herein. Such a fastening loop 106 may pass through a portion of a second catheter 559 or catheter 557 having a distal end that extends distally from a distal opening of the basket 102 .

[0483] Chordae (or Chordae Tendineae) are generally thought of as inelastic cords of fibrous connective tissue that connect the papillary muscles to the tricuspid and mitral valves. There are multiple chordae at each valve leaflet or cusp. During procedures to remove heart valve repairs and other procedures, it may be desirable to displace, restrict, and / or resect one or more chordae. In this regard, chordae capture and resection devices may be useful in some procedures.

[0484] As a general example, a chordae capture and resection device may have an elongated catheter body having at least one lumen extending therethrough and a capture member accessible through a distal opening of the lumen of the catheter body. The distal end of the capture member may have a feature or shape that engages one or more chordae in the heart. For example, the capture member may be an elongated shape memory wire having a distal end that, when unconstrained, has a memory shape of a spiral, loop, hook, cone / helical loop, nautical shape, square loop, oval loop, circular loop, triangular loop, rectangular loop, and similar shapes. Alternatively, the capture member may be a steerable catheter or guidewire that can be actuated by a user to form the aforementioned shapes when desired. Once engaged with one or more chordae, the capture member may restrict the position of the chordae or resect the chordae. For example, the chordae may be partially retracted into an opening or lumen of the catheter and the chordae may be severed by advancing a cutting element having a sharp edge against the chordae or by activating an RF electrode on a capture member.

[0485] 181, a chordae capture and resection device is shown comprising an elongate catheter body 562 having at least one lumen opening at a proximal end of the device and an opening 562A at a distal end of the device. The opening 562A opens in a sidewall of the catheter body 562 (e.g., generally perpendicular to the axis of the catheter body 562), but may also open at the axially most distal end or at a distal opening location.

[0486] The cutting element 564 may be disposed within the lumen of the catheter body 562. In this example, the cutting element may have a generally tubular shape at its distal end and may extend to the proximal end of the catheter body such that a user can translate the cutting element 564 distally and proximally. The distal blade of the cutting element 564 has a sharpened edge, here having a circular terminal edge of the tubular shape, and may be used to cut one or more chordae, as described further below.

[0487] The capture member 560 may be an elongated wire, multiple wires, a tubular structure, or similar elongated structure and may be disposed within the lumen of the catheter body 562, adjacent to the ablation element 564, or within the lumen of the ablation element 564, as shown in FIGURE 181. In this example, the distal end of the capture member 560 has a curved or spiral shape (e.g., either a spiral shape or a helical / spiral shape in a single plane) when unconstrained (when in the memory shape imparted to the shape memory material).

[0488] The capture members may have a variety of different shapes at their distal ends (e.g., forming a curved diameter in the range of about 0.15 inches or more and about 1.5 inches or less) for capturing one or more chordae. For example, FIG. 182 shows a capture member 566 having a hook shape. As another example, FIG. 183 shows a capture member 568 forming a spiral-like loop. As another example, FIG. 184 shows a capture member 570 forming a plurality of loops and terminating in a spiral shape. As another example, FIG. 185 shows a capture member 572 having a spiral-shaped loop that terminates in a sharp bend or hook shape. FIG. 186 shows a capture member 574 that is relatively wide and gently curved. The diameter of the underlying wire, wires, or structure of the capture member may be in the range of about 0.001 inches or more and about 0.030 inches or less.

[0489] The cutting element 564 is shown as having a tubular shape with a distal blade generally perpendicular to the axis of the cutting element 564, although other shapes and configurations are possible. For example, FIG. 187 shows a bias cutting blade 564A with edges disposed at a non-perpendicular angle (e.g., 45 degrees) relative to the axis of the cutting element 564. As another example, FIG. 188 shows a distal blade 564B that forms multiple prongs (e.g., two prongs in the case of a fork shape). As another example, FIG. 189 shows a distal blade that forms a single prong 164C. As another example, FIG. 190 shows a distal blade 564D that has a square or step shape with relatively perpendicular edges. Any of these distal blades may be made in the form of a tube or solid device (e.g., blade 564C may be cone shaped).

[0490] Any of the examples of cutting elements may be used with the examples of capture members disclosed herein.

[0491] 191-194 show an exemplary method of using the chordae capture and ablation device. First, as shown in FIG. 191, the distal end of the catheter body 562 is advanced into the heart so that the opening 562A is located near the chordae 21 to be ablated. In this example, the left atrium can be accessed, but may also be accessed through the leaflets 22, 24 of the valve.

[0492] 192, the capture member 560 is advanced distally from the opening 562A, causing a distal portion of the capture member 560 to slowly assume its unconstrained memory shape (in this example, a spiral or loop shape) as it advances. In this example, as the distal portion of the capture member 560 advances distally, the capture member 560 slowly assumes its memory shape to partially or completely encircle one or more chordae 19. Additionally, the capture member 560, especially if having a spiral shape, can be rotated to encircle the chordae 21 one or more times.

[0493] 193, once the capture member 560 has encircled one or more chordae at its distal end, the capture member 560 can be withdrawn proximally to retract the chordae at least partially into the lumen of the catheter body 562. In this regard, it can be useful for the opening 562A to be large enough to allow the distal end of the capture member 560 to return to the lumen of the catheter body 562 after expansion without releasing the chordae 19.

[0494] 194, the user may advance the cutting element 560 distally to bring the distal cutting blade into contact with and cut the chordae 19. The above-described positioning and cutting element may be performed multiple times during a procedure until all of the targeted chordae 21 have been cut.

[0495] 195-198 show a similar technique, except that the capture member 560 is first advanced distally to encompass both the chordae 21 and the heart valve clip 40 (FIG. 196), clamped (FIG. 197), and then the capture member 560 is moved downwardly away from the heart valve clip 40 (FIG. 198). The chordae 21 may be cut with a cutting element as previously described, or may be cut with a separate cutting device (e.g., a hook-shaped cutting loop).

[0496] 199-200 show a similar procedure to that described above, but with a capture member 560 having an electrode 561 that can be energized (eg, with RF energy) to sever the chordae.

[0497] As previously described herein, any of the resection loops disclosed herein may include multiple electrodes that are independently wired (i.e., each forming a different circuit that can be independently activated), such as resection loop 546 of FIGS. 168-170. Such a multi-electrode resection loop may be connected to a power source (e.g., an RF power source) that can sense and power these electrodes independently, allowing a user to determine if a particular electrode is in contact with tissue or blood and then specify which electrode should be electrically activated.

[0498] For example, Figs. 201 and 202 show an RF power generator or power supply 600 having a user interface 602 configured to display information within the RF power generator housing or on a separate display that can be connected. The generator 600 may also have user input via a keyboard or touch screen interface. It should be understood that the generator 600 is a computing device that may have a processor and memory that stores software that can be executed by the processor to perform the described functions.

[0499] The user interface 602 may include a first tissue contact display that displays information indicating which electrode (e.g., electrodes 1, 2, and / or 3) is in contact with tissue, as shown in FIG. 201. The tissue contact display may be a graphical representation of a resection loop, as shown in FIG. 201, a numerical display, or variations thereof. Contact with tissue may be determined by continuously measuring an electrical value, e.g., impedance, of each electrode and determining that tissue contact has occurred when the electrical value exceeds a certain threshold.

[0500] The user interface 602 may also have a second electrode activation display that allows the user to determine which electrodes are electrically activated when power is applied to the resection loop, as shown in FIG. 202. The electrode activation display may be a graphical representation of the resection loop, as shown in FIG. 202, a numerical display, or variations thereof. The display may include an indicator, symbol, word, or other display element that indicates whether the electrode is activated or deactivated. Additionally, the activation display and tissue contact display may be incorporated into the same screen to display data simultaneously.

[0501] In some circumstances, the heart valve clip may need to be removed from the patient, and it may be desirable to implant a heart valve clip that is more easily removable. For example, the heart valve clip may include shapes or areas that allow for easier capture, such as grooves or an enlarged distal end. Additionally, the heart valve clip may be configured to apply RF energy to specific locations that contact the valve tissue, such that upon contact with the electrodes of the resection loop, RF energy is delivered to the tissue contacting portion, allowing for a faster and more reliable release of the heart valve clip. For example, the heart valve clip may be constructed of a conductive material (e.g., the entirety or electrical pathways), with the remainder of the clip being insulated except for the tissue engaging portion in the "arms" of the clip. Alternatively, the exterior surface of the heart valve may be provided with electrode portions (e.g., raised areas, ridges, or similar features) that form electrodes, allowing a user to apply power to the valve clip and turn, twist, pull, or otherwise move the valve clip to sever and release the valve clip from the patient.

[0502] 203-207 show an example of a heart valve clip 610 having an elongated body and a leaflet engagement mechanism having two elongated arms 610A that form an adjustable "U" shape to clamp or engage leaflet tissue. The distal end of the valve clip 610 may include a snare engagement feature 612 to facilitate engagement of a snare loop. In this example, the feature 612 may include a channel or groove that extends partially or entirely around the diameter of the valve clip 610. Alternatively, the valve clip 610 may include an enlarged portion at its distal end. In either case, a snare loop may be placed over the feature 612 and tightened to provide a tight connection. The distal end of the feature 612 is shown as being circular or cylindrical, but may be more rectangular or other shapes, such as feature 616 shown in FIG. 208.

[0503] The heart valve clip 610 may include areas for forming electrodes, such as on the inner surface of the arms 610a. These areas may include raised edges or shapes similar to the electrodes of the resection loop described above. Depending on the construction of the valve clip 610, an insulating coating may be applied to areas unlikely to come into contact with tissue.

[0504] The resection loop may contact other locations on the valve clip 610 that are in electrical communication with the electrode surfaces to pass electrical current to those electrode surfaces. For example, feature 612 may form an electrical path to the inner surface of arm 610A that contacts the leaflet tissue. In such an example, the resection loop with the electrode may act as a snare that encompasses and engages feature 612 while providing power to the various areas of the valve clip 610 that engage the leaflet tissue.

[0505] The present specification and drawings include many different embodiments and features of the removal device and its method of use. Although a feature or technique may be described in relation to a particular embodiment, it is the intention of the applicant that the features shown in any embodiment may be incorporated in other embodiments. In other words, any of the features described herein may be mixed and matched with one another, and therefore the claims should not be limited or restricted to only the embodiments discussed and depicted herein.

[0506] As used herein, the term "substantially" or "generally" refers to the complete or nearly complete extent or degree of an action, feature, characteristic, state, structure, item, or result. For example, an object that is "substantially" or "generally" surrounded may mean that the object is completely surrounded or nearly completely surrounded. The exact allowable deviation from absolute completeness may depend on the particular circumstances. Generally speaking, however, the proximity of completeness will generally result in having the same overall result as if absolute and total completeness were obtained. The use of "substantially" or "generally" is equally applicable when used in a negative connotation referring to a complete or nearly complete lack of an action, feature, characteristic, state, structure, item, or result. For example, an element, combination, embodiment, or composition that is "substantially free" or "generally free" of a component or element may actually include such element, so long as there is generally no measurable effect.

[0507] As used herein, the term "one embodiment" or "example" means that a particular element, feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment.

[0508] As used herein, the terms "comprises," "comprising," "includes," "including," "has," "having," or any other variations thereof, are intended to include non-exclusive inclusions. For example, a process, method, article, or device that includes a list of elements is not necessarily limited to only those elements, but may include other elements not expressly listed or inherent in such process, method, article, or device. Furthermore, unless expressly stated to the contrary, "or" refers to an inclusive or, not an exclusive or. For example, a condition A or B is satisfied by any one of A being true (or present) and B being false (or absent), A being false (or absent) and B being true (or present), or both A and B being true (or present).

[0509] Furthermore, the use of "a" or "an" is used to describe elements and components of the embodiments herein. This is done merely for convenience and to give a general sense of the description. The description should be read to include one or at least one, and the singular also includes the plural unless it is clear that it is meant otherwise.

[0510] Moreover, the figures depict preferred embodiments for purposes of illustration only, and those skilled in the art will readily recognize from the description herein that alternative embodiments of the structures and methods shown herein may be used without departing from the principles described herein.

[0511] Although the present invention has been described with respect to specific embodiments and applications, those skilled in the art may, in light of this teaching, generate additional embodiments and modifications without departing from the spirit or beyond the scope of the claimed invention. It is therefore to be understood that the drawings and descriptions herein are provided as examples to facilitate understanding of the present invention and should not be construed as limiting its scope.

Claims

1. 1. A snare catheter for use in a medical procedure on a patient, comprising: an elongate sheath having a lumen and one or more openings at a distal portion thereof communicating with the lumen; an internal control member extending within the elongate sheath; a snare loop disposed at a distal end of the internal control member and extending outwardly from the one or more openings; and an electrical insulator configured to reduce transmission of electrical current between electrical ablation devices within the patient's heart.

2. The snare catheter of claim 1 , wherein the electrical insulator is disposed over a portion or the entirety of the snare loop.

3. The snare catheter of claim 1 , wherein the electrical insulator comprises a coating layer or a tube comprising silicone, polyolefin, polyimide, a dielectric material, PTFE, or FEP.

4. 10. The snare catheter of claim 1, wherein the snare loop comprises one or more wires comprising nitinol or stainless steel.

5. 2. A snare catheter as described in claim 1, wherein in some aspects the technology described herein relates to a snare catheter, wherein the elongate sheath further includes a distal end member located at a distal end of the elongate sheath and defining the one or more openings, and wherein the electrical insulator further includes a layer, coating, or structural material.

6. The snare catheter of claim 5 , wherein the distal end member has a rounded, curved, or blunt shape around the one or more openings to reduce or limit damage to the electrical insulator.

7. The snare catheter of claim 6 , wherein the rounded, curved, or blunt shape is formed by an insert connected to the distal end member or by the distal end member.

8. The snare catheter of claim 7 , wherein the one or more openings are located on a side of the distal end member relative to the axis of the elongate sheath.

9. 1. A snare catheter for use in a medical procedure on a patient, comprising: an elongated sheath having a lumen; an internal control member extending within the elongate sheath; a snare loop disposed at a distal end of the internal control member; a distal end member connected to the distal end of the elongated sheath and having a first opening and a second opening leading to a lumen of the elongated sheath, wherein the snare loop is positioned passing through the first opening and the second opening such that structural features of the first opening and the second opening prevent the snare loop from being completely drawn into the lumen of the elongated sheath.

10. The snare catheter of claim 9 , wherein the structural feature of the distal end member is a bar or a pin.

11. 1. A snare catheter for use in a medical procedure on a patient, comprising: an elongate sheath having a lumen and one or more openings at a distal portion thereof communicating with the lumen; an internal control member extending within the elongate sheath; a snare loop disposed at a distal end of the internal control member and extending outwardly from the one or more openings, The snare loop is configured so that when a force in the range of about 0 grams or more and about 3 grams or less is applied to the snare loop, the deflection of the distal end of the snare loop is limited to a range of about 0 mm or more and about 10 mm or less.

12. The snare catheter of claim 11, wherein the snare loop is configured such that when a force in the range of about 0 grams or more and about 2 grams or less is applied to the snare loop, the deflection of the distal end of the snare loop is limited to a range of about 0 mm or more and about 5 mm or less.

13. The snare catheter of claim 11 , wherein the snare loop comprises a solid shape memory wire having a diameter in the range of about 0.001 inches or more and about 0.03 inches or less.

14. 1. A tissue ablation catheter for use in a medical treatment of a patient, comprising: an elongated catheter body; a resection loop extending from a distal portion of the elongated catheter body, the resection loop including one or more shape memory wire segments and one or more electrodes made of a non-shape memory material.

15. The tissue ablation catheter of claim 14 , wherein the one or more electrodes comprise stainless steel.

16. The tissue ablation catheter of claim 14 , wherein the one or more electrodes comprise a tube or sleeve connected to the one or more shape memory wire segments.

17. The tissue ablation catheter of claim 14 , wherein the one or more electrodes each comprise a non-shape memory wire segment.

18. The tissue ablation catheter of claim 14 , wherein the one or more electrodes are radially larger than the one or more shape memory wire segments.

19. The tissue ablation catheter of claim 14 , wherein the ablation loop is an open loop or a closed loop.

20. 1. A tissue ablation catheter for use in a medical treatment of a patient, comprising: an elongated catheter body; a resection loop extending from a distal portion of the elongated catheter body, the resection loop including a main loop segment and one or more electrodes, the one or more electrodes having a larger diameter than the main loop segment.

21. The tissue ablation catheter of claim 20 , wherein the one or more electrodes have a cylindrical, spherical, cubic, curved and / or ridged shape.

22. 21. The tissue ablation catheter of claim 20, wherein the one or more electrodes are disposed over a portion of the main resection loop segment, the one or more electrodes being disposed above, below, or adjacent an insulating layer of the main resection loop segment.

23. The tissue ablation catheter of claim 20 , wherein the one or more electrodes extend all or part of the circumference of the main resection loop segment.

24. 21. The tissue ablation catheter of claim 20, wherein the one or more electrodes are wire segments connected to segments adjacent the main resection loop segment.

25. 1. A tissue ablation catheter for use in a medical treatment of a patient, comprising: an elongated catheter body; a resection loop extending from a distal portion of the elongated catheter body, the resection loop including one or more main loop segments and an electrode, the electrode including a wire connected to a first location of the resection loop and a second location of the resection loop, forming a space or gap in a portion of the resection loop.

26. 1. A tissue ablation catheter for use in a medical treatment of a patient, comprising: an elongated catheter body; a resection loop extending from a distal portion of the elongated catheter body, the resection loop including a plurality of electrodes.

27. 27. The tissue ablation catheter of claim 26, wherein the plurality of electrodes includes a first electrode disposed at a central and distal-most position of the resection loop.

28. 30. The tissue ablation catheter of claim 27, wherein the plurality of electrodes includes a second electrode and a third electrode disposed in a distal half of the resection loop and on either side of the first electrode.

29. 27. The tissue ablation catheter of claim 26, wherein the plurality of electrodes includes a first electrode disposed on a first side of the resection loop and a second electrode disposed on a second side of the resection loop.

30. 1. A capture basket catheter for use in a medical treatment of a patient, comprising: an elongated catheter body; a capture basket disposed in a distal portion of the elongated catheter body, the capture basket being connected a first distance from the distal end of the elongated catheter body and a second distance from the distal end of the catheter body that is less than the first distance.

31. 31. The capture basket catheter of claim 30, wherein the capture basket is connected to the first distance by a fastening loop.

32. 32. The capture basket catheter of claim 31, wherein the capture basket is connected at the second distance between a wire of the capture basket and an opening in the elongate catheter body.

33. 33. The capture basket catheter of claim 32, wherein the opening is located at a distal end of the elongated catheter body.

34. 1. A catheter delivery device for use in a medical procedure on a patient, comprising: an elongated sheath through which the sheath lumen passes; a sheath hub connected to a proximal end of the elongated sheath, the sheath hub including a plurality of ports opening into a cavity, the cavity narrowing in width distally, the cavity having a funnel at a distal end thereof, the funnel opening into a sheath lumen of the elongated sheath.

35. 1. A chordae resection device for use in a medical procedure on a patient, comprising: an elongated catheter body having a catheter lumen, the elongated catheter body having an opening leading from a distal portion of the elongated catheter body to the catheter lumen; a longitudinally movable ablation element disposed within the catheter lumen; an elongate capture member having a distal end that forms a curved shape when unconstrained and movable by a user to extend from the opening; 1. A chordae resection device, the chordae resection device forming a curved shape configured to at least partially surround one or more chordae in the heart and draw the chordae into an opening, the resection element being movable within the catheter lumen distally relative to the chordae to resect the chordae.

36. The chordae resection device of claim 35 , wherein the elongate capture member is disposed within a lumen of the resection element.

37. The chordae resection device of claim 35, wherein the elongate capture member is disposed within the catheter lumen and outside the resection element.

38. The chordae resection device of claim 35, wherein the opening is disposed through a sidewall of the catheter body.

39. The chordae resection device of claim 35, wherein the curved shape is a loop, a spiral, a helical, a hook, or multiple loops terminating in a hook shape.

40. 36. The chordae resection device of claim 35, wherein the capture member comprises one or more wires having a diameter in the range of about 0.001 inches or more and about 0.030 inches or less.

41. 36. The chordae resection device of claim 35, wherein the curved shape has a working diameter in the range of about 0.15 inches or more and about 1.5 inches or less.

42. 36. The chordae device of claim 35, wherein the cutting element has a distal end that forms a bias cutting blade, multiple points, a single point, or a step shape.

43. 36. The chordae device of claim 35, wherein the cutting element is tubular or solid in shape.

44. 36. The chordae tendon device of claim 35, wherein the ablation element is an electrode disposed on the capture member and configured to deliver an electrical current to ablate tissue.

45. 1. A method of medical treatment for a chordae, comprising: advancing an elongate catheter body towards the heart; advancing a distal portion of an elongate capture member through an opening in the elongate catheter body; allowing a distal portion of the elongate capture member to bend around one or more chordae; moving the distal portion of the elongate capture member and a portion of one or more chordae into the lumen of the elongate catheter body; and actuating a cutting element within the lumen of the elongate capture member to cut the one or more chordae.

46. 46. ​​The method of claim 45, wherein actuating a cutting element further comprises moving a cutting blade of the cutting element distally relative to one or more chordae.

47. 46. ​​The method of claim 45, wherein actuating an ablation element comprises providing RF power to an electrode of the elongate capturing member.

48. 46. ​​The method of claim 45, wherein allowing the distal portion of the elongate capture member to bend around the one or more chordae also includes allowing the distal portion of the elongate capture member to bend around a heart valve clip.

49. 1. A method of medical treatment for a chordae, comprising: advancing an elongate catheter body towards the heart; advancing a distal portion of an elongate capture member through an opening in the elongate catheter body; allowing a distal portion of the elongate capture member to bend around one or more chordae and a heart valve clip; moving the distal portion of the elongate capture member and a portion of one or more chordae into a lumen of the elongate catheter body; and advancing another ablation element into the heart to sever the captured one or more chordae tendineae.

50. 1. A method of medical treatment for a chordae, comprising: advancing an elongate catheter body towards the heart; advancing a distal portion of an elongate capture member through an opening in the elongate catheter body; allowing a distal portion of the elongate capture member to bend around one or more chordae; and actuating an electrode of the elongate capture member to sever the one or more chordae tendineae.

51. 1. An RF power generator for medical treatment of a patient, comprising: an RF power generator housing including a processor, a memory, and software code executable by the processor; a user interface controllable by a processor and software code; The software code is configured to measure electrical signals of a plurality of electrodes of the resection loop and indicate whether each of the plurality of electrodes is in contact with tissue.

52. 1. An RF power generator for medical treatment of a patient, comprising: an RF power generator housing including a processor, a memory, and software code executable by the processor; a user interface controllable by a processor and software code; The software code is configured to individually enable or disable multiple electrodes on a resection loop, RF power generator.

53. 1. A heart valve clip for use in treating a heart valve, comprising: A clip body and a leaflet attachment mechanism configured to attach to leaflet tissue; A heart valve clip comprising: a snare engagement feature, including a channel, groove, or enlarged structure, on at least a bottom portion of the clip body.

54. 1. A heart valve clip for use in treating a heart valve, comprising: A clip body and a leaflet attachment mechanism configured to attach to leaflet tissue; an electrode configured to deliver an electrical current when an electrical current is supplied to the clip body.

55. 1. A tissue ablation catheter for use in a medical treatment of a patient, comprising: an elongated catheter body; a resection loop extending from a distal portion of the elongate catheter body and including one or more electrodes; A tissue ablation catheter, wherein each of the one or more electrodes has a surface area within the range of about 0.003 to about 0.006 square inches.

56. 56. The tissue ablation catheter of claim 55, wherein the one or more electrodes each have a surface area of ​​about 0.00437506 square inches.

57. 56. The tissue ablation catheter of claim 55, wherein the one or more electrodes are connected to a power source configured to provide RF power in the range of about 5 Watts or more and about 1600 Watts or less.

58. 56. The tissue ablation catheter of claim 55, wherein each of the one or more electrodes has a surface area within the range of about 0.003 to about 0.030 square inches.

Images