Method and apparatus for removing a heart valve treatment device

Abstract

A retrieval catheter and method of use for removing heart valve repair, such as a valve leaflet clip or prosthetic valve leaflet chordae, are described. The retrieval catheter can include a cutting element and 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 repair, then manipulating the catheter and associated tools to cut tissue as needed, then removing the heart valve repair, and withdrawing the catheter.

Description

Technical Field

[0001] (Related Applications) This application claims priority to U.S. Provisional Application No. 63 / 081,504, filed September 22, 2020, entitled "Method and Apparatus for Securing and Tightening a Valve Clip"; U.S. Provisional Application No. 63 / 144,399, filed February 1, 2021, entitled "Valve Tip Clip Removal (Snareshaft Tip)"; and U.S. Provisional Application No. 63 / 187,285, filed May 11, 2021, entitled "Clip Removal to Avoid Chordae Entanglement", the entire contents of which are incorporated herein by reference.

[0002] The present disclosure relates to novel and advantageous endovascular devices and methods for facilitating the repair and / or replacement of valves. More specifically, the devices and methods herein relate to the removal of treatments that interact with the valve leaflets of a heart valve.

Background Art

[0003] Diseases of the heart valves can occur when the valve leaflets of a patient cannot fully close, allowing blood to regurgitate or abnormally backflow. Referring to FIG. 1, regurgitation is particularly common in mitral valve 20 where the anterior leaflet 22 of the mitral valve cannot properly couple with the posterior leaflet 24. When the ventricles of heart 10 contract, some blood returns from left ventricle 14 to left atrium 12 instead of aorta 11. A similar regurgitation can occur in tricuspid valve 15, where blood can return from right ventricle 13 to right atrium 16.

[0004] A common treatment for valvular regurgitation is the use of therapeutic devices that overlap or permanently link valve leaflets. This heart valve therapeutic hardware may be implanted using surgical, transcatheter, or minimally invasive means. For example, hardware or treatments to be removed may include MitraClip (Abbott Structural, Santa Clara, CA), PASCAL devices (Edwards Lifesciences, Irvine, CA), surgically placed sutures (e.g., Alfieri sutures), or similar heart valve treatments. Other heart valve treatments may be the result of techniques in which valve leaflets are involved as part of the therapeutic target, and the involvement of part or all of the valve leaflets requires resection. Other examples include chordal replacement techniques implanted using either transcatheter or surgical methods to compensate for inadequate length, splitting, or displacement of existing chordae tendineae. For the purposes of this application, the phrase “heart valve therapeutic” is defined as any device and / or method used in the therapeutic treatment of the heart valve, including leaflet clips, sutures, artificial chordae tendineae, or other devices or methods related to the treatment of the heart valve and associated leaflets.

[0005] Figure 2 shows an exemplary transcatheter delivery procedure for a valve clip 40 (e.g., MitraClip) to treat a regurgitating mitral valve 20. The 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 Figure 3, the inner portion of the catheter 41A containing the valve clip 40 is advanced through the mitral valve 20 into the left ventricle 14. In this embodiment, the valve leaflet clip 40 includes two outer arms 40A positioned below the valve leaflets 22, 24 and two inner arms 40B positioned perpendicularly between the two valve leaflets 22, 24. As seen in Figure 3, the catheter 41 includes a control wire that can close the outer arms 40A against the inner arms 40B to pinch or engage the leaflet tissue. As shown in Figure 4, a return or similar structure on the arms 40B helps the valve leaflet clip 40 to be fixed in the tissue of the valve leaflets 22, 24. Finally, as shown in Figure 5, the catheter 41 is removed. As seen in the top view of Figure 6, the valve leaflet clip 40 is typically positioned near the center of the valve 20 to prevent the center from opening and to form two smaller valve openings on either side of the clip 40. The smaller the diameter of these openings, the better the seal of the valve leaflets is typically, thus preventing backflow.

[0006] In some cases, these structures may need to be removed to facilitate other valve treatments, such as when regurgitation requiring treatment recurs or persists. For example, the valve may require annuloplasty or rings, chordae or cords, positioning devices, or replacement valve placement, many of which may not be usable with previously performed heart valve treatments.

[0007] In some cases, these treatments may need to be removed from one or more attachment points on the valve leaflets, but not necessarily completely, in order to facilitate other valve treatments. The structure may remain in the heart, but it can be moved away from the area of ​​interest so that the desired treatment can be applied.

[0008] However, these heart valve treatments are typically removed by 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 approach to removing heart valve treatments that reduces the risk of complications. [Overview of the project]

[0009] This disclosure relates to a system and method for removing a heart valve treatment that has been used to position the valve leaflets. This removal may be necessary when further treatment is required for the treatment of a valve disease (e.g., a different repair method, valve replacement), when the heart valve treatment has caused or may cause harm to the patient (e.g., stenosis, infection), when the heart valve treatment is considered clinically unbeneficial, or when it is generally desired not to perform the treatment.

[0010] This disclosure relates to a system and method for removing a heart valve treatment used to position a valve leaflet, which may have been placed using surgical, transcatheter, or minimally invasive means. In at least one embodiment, the hardware or treatment to be removed 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 a positioning device to be removed may be the result of a technique in which a valve leaflet is involved as part of a therapeutic target, and the involvement of part or all of the valve leaflet necessitates removal. An example of such a device is chordae tendineae replacement techniques placed using either transcatheter or surgical methods. In some cases, the chordae or cords are ineffective due to improper length, splitting, misalignment, or defects in the prosthetic material.

[0011] The present invention includes a tool for cutting natural valve tissue attached to a heart valve treatment, with or without a capture tool, and holding the hardware to be removed while it is exposed from the human body. In at least one embodiment, the cutting method consists of an adjustable snare covering the heart valve treatment and mechanically cutting the natural tissue from the heart valve treatment, or by using an RF electrosurgical device that heats the tissue so that the intracellular temperature of the electrosurgical cutting device rapidly reaches 100°C, thereby converting the intracellular contents from liquid to gas, causing a large volume expansion and resulting in evaporation. In at least one embodiment, the capture tool is an adjustable basket, bag, or bin. This capture tool can be used to cut, release, compress, modify, or completely recover the heart valve treatment from the human body.

[0012] In some embodiments, a method for removing a previously placed cardiac valve treatment consists of a manipulable catheter inserted into the patient using a transseptal, transatrial, or transventricular approach. The manipulable catheter includes a delivery catheter that allows for the placement of a tool for cutting and capturing the cardiac valve treatment.

[0013] In some embodiments, capture of a heart valve helix is ​​performed by the direct insertion and implantation of a tool into, on, and / or around the heart valve helix. This approach cuts the natural tissue from the heart valve helix by using an electrosurgical cutting device (RF electro or similar device) or similar energy or force delivered from within the implanted tool. A basket or bag for capturing the heart valve helix may not be necessary for the removal of the target material. Therefore, in at least one embodiment, the cutting tool is used alone without the need for a capture basket.

[0014] In at least one embodiment, the loop structure is pressed onto a fixation method created by a tissue bridge, chordae tendineae implant, or heart valve treatment. The loop structure can be used to cut by either electrical or mechanical means. The loop structure may be circular, elliptical, or segmented and may completely or partially encapsulate an area for cutting and removal. The loop structure can be used to surround heart valve treatment and tissue for removal, after which it is exposed.

[0015] In at least one embodiment, the tool is used to expand the heart valve hemostat for removal. This expansion may be by mechanical, electrical, pneumatic, hydraulic, or similar means to unfold or alter the shape of the heart valve hemostat for removal.

[0016] The elements of the tool can be fixed in place during heart valve treatment, reducing the risk of embolism. This fixation can be achieved by anchors, which are linear, helical, ribbed, or a combination of these approaches.

[0017] In at least one embodiment, a catheter, spacer, balloon, or other device can be used in combination with a removal device to manage blood flow or regurgitation after valve removal in cardiac valve therapy. This can be done quickly if the removed cardiac valve and basket can be retracted via an operable catheter, and the sealing device can then be delivered via the same delivery catheter.

[0018] Further embodiments of the present invention relate to a removal system for valve clips or similar heart valve treatments, which may include a cutting and capture catheter and a snare catheter deployable from the same or a separate delivery catheter. The snare catheter can be used to first grasp the valve clip and pull it distally (for example, further into the left ventricle) to create tension or force on the valve leaflets. Next, the cutting loop and basket of the cutting and capture catheter can be positioned on the valve clip such that the cutting loop is positioned proximal or atrial to the heart valve treatment. Finally, the cutting loop can be activated to cut the heart valve treatment device, and the clip can finally be captured in the basket and removed from the patient. This design allows the cutting loop to be pulled through the tissue, and the capture basket to close around the heart valve treatment device while simultaneously cutting and capturing the heart valve treatment.

[0019] The snare catheter may include a snare loop having a circular shape or an elliptical saddle shape forming an arc shape along each side. The snare loop may have multiple teeth, have a friction coating, or be made of a coiled wire. The snare catheter may include features that create friction between its distal tip, which has an opening in its side wall, and the captured valve clip, such as a steep edge, ridge, groove, or hook.

[0020] The snare catheter may include a handle configured to house the snare loop within the snare catheter. The handle may include a mechanism to ensure constant tension on the clip and a mechanism to limit the force the user applies to the tightened snare. The handle may include a locking mechanism to lock the snare in the desired storage position.

[0021] Furthermore, the removal system may include a guidewire passage through one or both of the cutting / recapture catheter and the snare catheter. In specific examples, the guidewire passage may extend through the baskets of the snare catheter and the cutting / recapture catheter. The guidewire may extend longitudinally across the recapture basket, or along the inside of the tip and the outside of the surface of the basket.

[0022] The removal system may include a chordal dilator configured to at least partially block the distal opening of the delivery catheter and provide a relatively smooth transition with fewer steep surfaces where the chordae tendineae or other features of the valve might "catch."

[0023] The cutting and capture catheter may include an expandable capture basket that expands from a longitudinally compressed configuration to a longitudinally extended configuration when a valve clip is captured.

[0024] The removal system may also include a catheter configured to apply counterforce by pressing the valve clip from the atrial side of the valve. Thus, the cutting loop of the cutting / removal catheter can be better positioned between the atrial side of the valve clip and the valve leaflet. The catheter may be configured for contact only, or it may be configured to engage or attach evenly to the valve clip.

[0025] The removal system may include a snare catheter containing a cutting element that can engage with the surrounding tissue or other cardiac valve treatments to facilitate capture and removal of the valve clip.

[0026] While several embodiments are disclosed, further embodiments of this disclosure will become apparent to those skilled in the art from the following detailed description illustrating and describing exemplary embodiments of the invention. As will be understood, all the various embodiments of this disclosure can be modified in various obvious ways without departing from the spirit and scope of this disclosure. Accordingly, the drawings and detailed description should be considered as illustrative and not limiting in nature. [Brief explanation of the drawing]

[0027] These and other aspects, features, and advantages of embodiments of the present invention will become apparent and will be clarified from the following description of embodiments of the present invention.

[0028] [Figure 1] Figure 1 shows an anatomical view of the heart.

[0029] [Figure 2] Figure 2 shows a side view of a procedure for implanting a leaflet heart valve treatment device.

[0030] [Figure 3] Figure 3 shows a side view of a procedure for implanting a leaflet heart valve treatment device.

[0031] [Figure 4] Figure 4 shows a side view of a procedure for implanting a leaflet heart valve treatment device.

[0032] ] [Figure 5] Figure 5 shows a side view of a procedure for implanting a leaflet heart valve treatment device.

[0033] [Figure 6] Figure 6 shows a top view of a procedure for implanting a leaflet heart valve treatment device. [[ID=[]]

[0034] 3] [Figure 7] Figure 7 shows a side view of a removal catheter according to the present invention.

[0035] [Figure 8] Figure 8 shows a side view of a removal catheter according to the present invention.

[0036] [Figure 9] Figure 9 shows a side view of a removal catheter according to the present invention.

[0037] [Figure 10]Figure 10 shows a side perspective view of the removal catheter according to the present invention.

[0038] [Figure 11] Figure 11 shows a side view of the removal catheter according to the present invention.

[0039] [Figure 12] Figure 12 shows a cross-sectional view of the removal catheter according to the present invention.

[0040] [Figure 13] Figure 13 shows an exploded view of the removal catheter according to the present invention.

[0041] [Figure 14] Figure 14 shows a perspective view of the cut loop according to the present invention.

[0042] [Figure 15] Figure 15 shows a perspective view of the cut loop according to the present invention.

[0043] [Figure 16] Figure 16 shows a perspective view of the cut loop according to the present invention.

[0044] [Figure 17] Figure 17 shows a perspective view of the cut loop according to the present invention.

[0045] [Figure 18] Figure 18 shows a perspective view of the cut loop according to the present invention.

[0046] [Figure 19] Figure 19 shows a perspective view of the cut loop according to the present invention.

[0047] [Figure 20] Figure 20 shows a top view of the cutting loop according to the present invention.

[0048] [Figure 21]Figure 21 shows a top view of the cutting loop according to the present invention.

[0049] [Figure 22] Figure 22 shows a perspective view of the cut loop according to the present invention.

[0050] [Figure 23] Figure 23 shows a cross-sectional view of the cut loop according to the present invention.

[0051] [Figure 24] Figure 24 shows a cross-sectional view of the cut loop according to the present invention.

[0052] [Figure 25] Figure 25 shows a cross-sectional view of the cut loop according to the present invention.

[0053] [Figure 26] Figure 26 shows a cross-sectional view of the cut loop according to the present invention.

[0054] [Figure 27] Figure 27 shows a cross-sectional view of the cut loop according to the present invention.

[0055] [Figure 28] Figure 28 shows a cross-sectional view of the cut loop according to the present invention.

[0056] [Figure 29] Figure 29 shows a cross-sectional view of the cut loop according to the present invention.

[0057] [Figure 30] Figure 30 shows a cross-sectional view of the cut loop according to the present invention.

[0058] [Figure 31] Figure 31 shows a side view of the basket according to the present invention.

[0059] [Figure 32]Figure 32 shows a side view of the basket according to the present invention.

[0060] [Figure 33] Figure 33 shows a side view of the removal catheter according to the present invention.

[0061] [Figure 34] Figure 34 shows a side perspective view of the removal catheter according to the present invention.

[0062] [Figure 35] Figure 35 shows a side perspective view of the removal catheter according to the present invention.

[0063] [Figure 36] Figure 36 shows a side perspective view of the removal catheter according to the present invention.

[0064] [Figure 37] Figure 37 shows a side view of the removal catheter according to the present invention.

[0065] [Figure 37] Figure 37 shows a side view of the removal catheter according to the present invention.

[0066] [Figure 39] Figure 39 shows a side view of the removal catheter according to the present invention.

[0067] [Figure 40] Figure 40 shows a side view of the basket according to the present invention.

[0068] [Figure 41] Figure 41 shows a side view of the basket according to the present invention.

[0069] [Figure 42] Figure 42 shows a side view of the basket according to the present invention.

[0070] [Figure 43]Figure 43 shows a side view of the basket according to the present invention.

[0071] [Figure 44] Figure 44 shows a side view of the handle according to the present invention.

[0072] [Figure 45] Figure 45 shows a side view of the handle according to the present invention.

[0073] [Figure 46] Figure 46 shows a side view of the removal catheter according to the present invention.

[0074] [Figure 47] Figure 47 shows a side view of the removal catheter according to the present invention.

[0075] [Figure 48] Figure 48 shows a side view of the removal catheter according to the present invention.

[0076] [Figure 49] Figure 49 shows a side view of the removal catheter according to the present invention.

[0077] [Figure 50] Figure 50 shows a side view of the removal catheter according to the present invention.

[0078] [Figure 51] Figure 51 shows a side view of the removal catheter according to the present invention.

[0079] [Figure 52] Figure 52 shows a side view of the removal catheter according to the present invention.

[0080] [Figure 53] Figure 53 shows a side view of the removal catheter according to the present invention.

[0081] [Figure 54]Figure 54 shows a side view of the removal catheter and guide catheter according to the present invention.

[0082] [Figure 55] Figure 55 shows a side view of the removal catheter and guide catheter according to the present invention.

[0083] [Figure 56] Figure 56 shows a side view of the removal catheter procedure according to the present invention.

[0084] [Figure 57] Figure 57 shows a side view of the removal catheter procedure according to the present invention.

[0085] [Figure 58] Figure 58 shows a side view of the removal catheter procedure according to the present invention.

[0086] [Figure 59] Figure 59 shows a side view of the removal catheter procedure according to the present invention.

[0087] [Figure 60] Figure 60 shows a side view of the removal catheter procedure according to the present invention.

[0088] [Figure 61] Figure 61 shows a side view of the removal catheter procedure according to the present invention.

[0089] [Figure 62] Figure 62 shows a side view of the removal catheter procedure according to the present invention.

[0090] [Figure 63] Figure 63 shows a side view of the removal catheter procedure according to the present invention.

[0091] [Figure 64] Figure 64 shows a side view of the removal catheter procedure according to the present invention.

[0092] [Figure 65] Figure 65 shows a side view of the removal catheter procedure according to the present invention.

[0093] [Figure 66] Figure 66 shows a side view of the removal catheter procedure according to the present invention.

[0094] [Figure 67] Figure 67 shows a side view of the removal catheter procedure according to the present invention.

[0095] [Figure 68] Figure 68 shows a side view of the removal catheter procedure according to the present invention.

[0096] [Figure 69] Figure 69 shows a side view of the removal catheter procedure according to the present invention.

[0097] [Figure 70] Figure 70 shows a side view of the removal catheter procedure according to the present invention.

[0098] [Figure 71] Figure 71 shows a side view of the removal catheter procedure according to the present invention.

[0099] [Figure 72] Figure 72 shows a side view of the removal catheter procedure according to the present invention.

[0100] [Figure 73] Figure 73 shows a side view of the removal catheter procedure according to the present invention.

[0101] [Figure 74] Figure 74 shows a side view of the removal catheter procedure according to the present invention.

[0102] [Figure 75] Figure 75 shows a side view of the removal catheter procedure according to the present invention.

[0103] [Figure 76] Figure 76 shows a side view of the removal catheter procedure according to the present invention.

[0104] [Figure 77] Figure 77 shows a side view of the removal catheter procedure according to the present invention.

[0105] [Figure 78] Figure 78 shows a side view of the removal catheter procedure according to the present invention.

[0106] [Figure 79] Figure 79 shows a side view of the removal catheter procedure according to the present invention.

[0107] [Figure 80] Figure 80 shows a side view of the removal catheter procedure according to the present invention.

[0108] [Figure 81] Figure 81 shows a side view of the removal catheter procedure according to the present invention.

[0109] [Figure 82] Figure 82 shows a side view of the removal catheter procedure according to the present invention.

[0110] [Figure 83] Figure 83 shows a side view of the removal catheter procedure according to the present invention.

[0111] [Figure 84] Figure 84 shows a side view of the removal catheter procedure according to the present invention.

[0112] [Figure 85] Figure 85 shows a side view of the removal catheter procedure according to the present invention.

[0113] [Figure 86]Figure 86 shows a side view of the removal catheter procedure according to the present invention.

[0114] [Figure 87] Figure 87 shows a side view of the removal catheter procedure according to the present invention.

[0115] [Figure 88] Figure 88 shows a side view of the removal catheter procedure according to the present invention.

[0116] [Figure 89] Figure 89 shows a side view of the removal catheter procedure according to the present invention.

[0117] [Figure 90] Figure 90 shows a side view of the removal catheter procedure according to the present invention.

[0118] [Figure 91] Figure 91 shows a side view of the removal catheter procedure according to the present invention.

[0119] [Figure 92] Figure 92 shows a side view of the removal catheter procedure according to the present invention.

[0120] [Figure 93] Figure 93 shows a side view of the removal catheter procedure according to the present invention.

[0121] [Figure 94] Figure 94 shows a side view of the removal catheter procedure according to the present invention.

[0122] [Figure 95] Figure 95 shows a side view of the removal catheter procedure according to the present invention.

[0123] [Figure 96] Figure 96 shows a side view of the removal catheter procedure according to the present invention.

[0124] [Figure 97] Figure 97 shows a side view of the removal catheter procedure according to the present invention.

[0125] [Figure 98] Figure 98 shows a side view of the removal catheter procedure according to the present invention.

[0126] [Figure 99] Figure 99 shows a side view of the removal catheter procedure according to the present invention.

[0127] [Figure 100] Figure 100 shows a side view of the removal catheter procedure according to the present invention.

[0128] [Figure 101] Figure 101 shows a perspective view of the removal catheter device according to the present invention.

[0129] [Figure 102] Figure 102 shows a perspective view of the removal catheter device according to the present invention.

[0130] [Figure 103] Figure 103 shows a perspective view of the removal catheter device according to the present invention.

[0131] [Figure 104] Figure 104 shows a perspective view of the removal catheter device according to the present invention.

[0132] [Figure 105] Figure 105 shows a perspective view of the removal catheter device according to the present invention.

[0133] [Figure 106] Figure 106 shows a perspective view of the removal catheter device according to the present invention.

[0134] [Figure 107] Figure 107 shows a perspective view of an example of a valve cut.

[0135] [Figure 108] Figure 108 shows a perspective view of the removal catheter device according to the present invention.

[0136] [Figure 109] Figure 109 shows a perspective view of the removal catheter device according to the present invention.

[0137] [Figure 110] Figure 110 shows a snare and removal system according to the present invention. [Figure 111] Figure 111 shows a snare and removal system according to the present invention.

[0138] [Figure 112] Figure 112 shows the tip of the basket according to the present invention. [Figure 113] Figure 113 shows the tip of the basket according to the present invention.

[0139] [Figure 114] Figure 114 shows a snare loop according to the present invention. [Figure 115] Figure 115 shows a snare loop according to the present invention.

[0140] [Figure 116] Figure 116 shows a snare loop according to the present invention.

[0141] [Figure 117] Figure 117 shows a snare loop according to the present invention.

[0142] [Figure 118] Figure 118 shows a part of the snare loop according to the present invention.

[0143] [Figure 119] Figure 119 shows a part of the snare loop according to the present invention.

[0144] [Figure 120] Figure 120 shows the tip portion of a snare catheter according to the present invention. [Figure 121] Figure 121 shows the tip portion of a snare catheter according to the present invention.

[0145] [Figure 122] Figure 122 shows the tip portion of a snare catheter according to the present invention.

[0146] [Figure 123] Figure 123 shows the tip portion of a snare catheter according to the present invention.

[0147] [Figure 124] Figure 124 shows the tip portion of a snare catheter according to the present invention.

[0148] [Figure 125] Figure 125 shows a handle for a snare catheter according to the present invention. [Figure 126] Figure 126 shows a handle for a snare catheter according to the present invention.

[0149] [Figure 127] Figure 127 shows a method for attaching and removing a valve clip according to the present invention. [Figure 128] Figure 128 shows a method for attaching and removing a valve clip according to the present invention. [Figure 129] Figure 129 shows a method for attaching and removing a valve clip according to the present invention. [Figure 130] Figure 130 shows a method for attaching and removing a valve clip according to the present invention.

[0150] [Figure 131] Figure 131 shows a removal system configured for access via a guidewire. [Figure 132]Figure 132 shows a removal system configured for access via a guide wire. [Figure 133] Figure 133 shows a removal system configured for access via a guidewire.

[0151] [Figure 134] Figure 134 shows a chordal decongestant according to the present invention. [Figure 135] Figure 135 shows a chordal decongestant according to the present invention. [Figure 136] Figure 136 shows a chordae tendineae expander according to the present invention. [Figure 137] Figure 137 shows a chordal decongestant according to the present invention.

[0152] [Figure 138A] Figure 138A shows a removal system with an alternative guidewire path.

[0153] [Figure 138B] Figure 138B shows a removal system with an alternative guidewire path.

[0154] [Figure 139] Figure 139 shows a removal system according to the present invention, which has a pigtail wire at the distal end of the basket.

[0155] [Figure 140] Figure 140 shows an expandable basket according to the present invention. [Figure 141] Figure 141 shows an expandable basket according to the present invention.

[0156] [Figure 142] Figure 142 shows a method for applying force to a valve clip according to the present invention.

[0157] [Figure 143A] Figure 143A shows an alternative basket shape according to the present invention.

[0158] [Figure 143B] Figure 143B shows an alternative basket shape according to the present invention.

[0159] [Figure 144] Figure 144 shows an alternative removal system of the present invention without a basket.

[0160] [Figure 145] Figure 145 shows an alternative removal system according to the present invention, which has a cutting element as part of the snare loop.

[0161] [Figure 146] Figure 146 shows an alternative removal system according to the present invention, which has a cutting element as part of the snare loop. [Modes for carrying out the invention]

[0162] Specific embodiments of the present invention will be described below with reference to the accompanying drawings. However, the present invention can be embodied in many different forms and should not be construed as being limited to the embodiments described herein. Rather, the following embodiments are intended to enable those skilled in the art to comprehensively, completely, and fully understand the scope of the present invention through this disclosure. The terms shown in the accompanying drawings and used in the detailed description of the embodiments are not intended to limit the present invention. In the drawings, similar numbers refer to similar elements.

[0163] The present invention generally relates to an apparatus and method for removing a cardiac valve therapy device via a transcatheter procedure. Current methods for removing cardiac valve therapy devices require open-heart surgery, but the art and apparatus of the present invention utilize a transcatheter apparatus and method that can provide a less invasive and better patient outcome.

[0164] For the purposes of this application, the phrase “heart valve therapy” is defined as any device and / or method used in the therapeutic treatment of the heart valve, including leaflet clips, sutures, artificial chordae tendineae, or other devices or methods relating to the treatment of the heart valve and associated leaflets. While certain heart valve therapy devices or methods, such as heart valve leaflet clips, may be discussed or illustrated in specific embodiments, it should be understood that use in any heart valve therapy is particularly intended. Therefore, use in any embodiment discussed herein should not be limited solely to use with heart valve leaflet clips.

[0165] Figures 1 to 13 show various aspects of one embodiment of a removal catheter 100 for removing a valve leaflet treatment device, such as a valve clip 40 or a 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 cutting loop 104 positioned near the top opening of the basket 102. As seen in Figures 7 and 8, the basket 102 is positioned over the implanted valve clip 40, and the top of the basket 102 and the cutting loop 104 are positioned between the clip 40 and the atrial valve leaflets 22, 24. Next, the top opening of the basket 102 is closed or reduced in diameter and the cutting loop 104 is activated to cut the valve leaflet tissue surrounding the valve clip 40 (e.g., by supplying high-frequency energy), and the clip 40 is released from the valve 20. Finally, the capture basket 102 containing the valve clip 40 is withdrawn and removed from the patient. Further details and variations of the removal catheter 100 are described below, followed by exemplary approaches and removal methods for various heart valves (e.g., mitral valve 20 or tricuspid valve 15).

[0166] As best shown in Figures 9 to 11, the removal catheter 100 includes an internal control member 108 (best shown in Figure 11) located within an outer tubular sheath 110. The internal control member 108 may be a solid wire or tube extending between the distal and proximal ends of the sheath 110. The basket 102 and cutting loop 104 are connected to the distal end of the internal control member 108 such that the basket 102 and cutting loop 104 move in the same direction as the internal control member 108 moves longitudinally or rotationally relative to the outer tubular sheath 110.

[0167] Referring to Figure 11, in one embodiment, a plurality of loops 102A are arranged around the circumference of the top opening of the basket 102, and a wire or tightening loop 106 is arranged through the loops 102A. As best shown in Figure 13, the tightening loop 106 may consist of a loop-shaped wire (e.g., circular, elliptical, etc.) and an elongated straight section 106A that can be connected to a control member 108 via a connecting sleeve 112. The connecting sleeve 112 can be secured to the control member 108 by clamping, welding, adhesive / epoxy resin, or any combination thereof. Alternatively, the tightening loop 106 can be connected to the control member 108 only by welding or adhesive.

[0168] The cutting loop 104 can also be formed into a general loop shape (e.g., circular, elliptical, saddle-shaped, etc.) and may include an elongated straight section 104E that can be connected to the control member 108 via the connecting sleeve 112. In this regard, as can be seen in the cross-sectional view of Figure 12, both the elongated straight sections 106A and 104E are located within the connecting sleeve 112.

[0169] In one embodiment, the cutting loop 104 cuts tissue when high-frequency energy is supplied to the cutting loop. In one example, an RF power source is connected to the proximal end of a control member 108 made of conductive metal, and thus transmits RF energy to its distal end, and then to the attached cutting loop 104. To complete the RF energy circuit having the cutting loop 104, a second RF electrode can be connected to the RF power source and attached to the patient at another location via an electrode pad (unipolar RF system), the second electrode can be included at another location on the removal catheter 100 (bipolar RF system), or a second insulated wire can be included on the control member 108 (bipolar RF system).

[0170] It may be desirable to isolate the RF energy circuit of the severing loop 104 from both the clamping loop 106 and the basket 102 to prevent damage to other tissues in the heart. This can be achieved by using an electrical insulator as a specific location on the device. For example, as seen in the cross-sectional view of Figure 12 and the exploded view of Figure 13, an electrical wire insulator 114 can be placed on the elongated straight section 106A (or optionally over the entire clamping loop 106) to electrically isolate the clamping loop 106 from the RF current of the control member 108.

[0171] In other examples shown in Figures 14–30, the cutting loop 104 can have different structures, shapes, and electrical insulators, which helps reduce the risk of the non-insulated portion 104B (i.e., the portion that cuts the valve leaflet tissue) coming into contact with any part of the clamping wire 106 or basket 102. For example, Figure 14 shows a cutting loop 104, where the non-insulated portion 104B of the wire is located opposite the elongated straight portion 104E and adjacent to the insulated portion 104A on each side. In this example, as seen in Figure 21, the non-insulated portion 104B may extend around the entire circumference of the wire, or it may be exposed only along the inside of the loop 104, as seen in Figure 20.

[0172] The non-insulated portion 104B may consist of only a single area (e.g., about 1–5 mm) where the underlying wire 104C is exposed, as shown in Figure 14, or it may consist of multiple separate non-insulated portions 104B (e.g., 2–10 portions 104B) of relatively short lengths (e.g., about 1–5 mm), as shown in Figure 22.

[0173] In all embodiments of the cutting loop, the majority of the surface of the cutting loop 104 is insulated. To form a non-insulated portion 104B, the cutting loop insulator 104A can be selectively removed (in the case of a wire with an existing insulator) to expose the cutting loop conduction wire 104C so that RF cutting energy can be brought into contact with and delivered to the valve leaflet tissue bridge when in contact with tissue adjacent to the heart valve treatment. Alternatively, an insulator 104A can be added (e.g., by dipping, spraying, or similar techniques), and the non-insulated portion 104B can be generated by masking the intended area before applying the insulator.

[0174] It is understood that the non-insulating portion 104B can be oriented in several ways, for example, not only on the inner / outer surfaces of the cut loop 104, but also on the bottom (i.e., atrium) side of the loop 104.

[0175] The wire 104C beneath the cutting loop 104 can be made of a shape memory metal (e.g., nitinol) or a similar conductive metal (e.g., stainless steel or copper). As seen in the cross-sectional views of Figures 23, 24, and 25, the underlying wire 104C can have a rectangular, circular, triangular, and square cross-section, respectively.

[0176] The cut loop 104 may consist of one or more wires, such as a first wire 104C and a second wire 104D. Both wires may be made of similar materials (e.g., Nitinol, stainless steel, copper, silver, or similar materials), or each wire may be made of different materials. For example, one wire 104C may be made of a metal that conducts current better (e.g., stainless steel, silver, or copper), and the other wire 104D may be made of a material that retains its shape between compression and expansion configurations (e.g., a shape memory metal such as Nitinol). Multiple wires may be electrically separated or insulated from each other or independently. Further different cross-sectional shapes can be used with the same or different materials, as seen in Figures 16-18 and 26-28.

[0177] In another example, the cut loop 104 can be composed of a single wire containing multiple strands of different wire materials. For example, Figures 19 and 29 show a wire core 104D consisting of a shape memory strand with multiple conductive strands 104C arranged circumferentially around a core 104D. In another embodiment, Figure 30 includes alternating shape memory strands 104D and conductive strands 104C. In this respect, different strands can provide both the desired current conduction and the ability to expand from a compressed form into a predetermined loop shape. The multiple wires can be electrically separated or insulated from each other or independently. Both of these cable examples can have 2 to 49 or more strands internally.

[0178] The cutting loop can have various different shapes, structures, and electrical insulation patterns to facilitate the removal of tissue around the clip 104, which can, for example, provide further length and / or a predetermined path or geometric shape. Figure 101 shows an alternative example of a cutting loop 316 having a “saddle” or corrugated shape in which each side 314, 315 of the loop curves downward (i.e., proximal toward the catheter 100) and its free end 311 curves upward (i.e., distal toward the catheter 100). The sides 314 and 315 are insulated, and the middle section 311 and the ends 312 and 313 are insulated. The middle section 311 contacts or engages with the tissue on one side of the loop 316, while the ends 312 and 313 contact or engage with the tissue on the other side. The sides 315 and 316 can be bent outward to increase the width of the loop 316, bent inward to decrease the width of the loop 316, or be kept relatively straight to maintain a uniform width (i.e., a circular or elliptical shape) of the loop 316.

[0179] The cutting loop 316 facilitates many different tissue engagement methods. For example, ends 312 and 313 can be electrically activated simultaneously first, while the cutting loop 316 applies axial tension to the tissue structure, effectively cutting the tissue in contact with these parts 312 and 313 and partially releasing the valve leaflet clip 40. Next, the free end 311 can be activated to excise the tissue adjacent to it, completing the excision of the valve leaflet clip 40 from the valve leaflet. Alternatively, all three parts 311, 312, and 313 can be activated simultaneously. The axial tension on the loop 316 can be applied before, during, or intermittently to control the engagement of the loop 316. Although this embodiment shows three non-insulated cutting regions or parts 311, 312, and 313, there can be any number of cutting elements (e.g., 1 to 100) including the entire loop 316 as a single continuous non-insulated cutting member.

[0180] By including an additional length along the lateral sections 314 and 315, other tissue structures present around the valve leaflet clip 40 can be accommodated. The additional length of the lateral sections 314 and 315 is also deformable so that when tension is applied by the elongated straight section 317, the lateral sections 314 and 315 become straight, and the loop 316 is stretched into a substantially axial shape. During this tension and stretching, the axial distance between the free end 311 and the proximal ends 312, 313 increases, including a greater variety of both diameter and approach angles to the clip. Such nonlinear paths can also achieve this and are therefore considered in this disclosure, but are not shown here for the sake of simplicity.

[0181] Figure 102 illustrates a delivery mechanism having an outer tubular sheath 320 which is substantially similar to that of the previously described cutting loop 316 and sheath 110. However, the outer tubular sheath 320 further includes a sheath cutting section 321 located at the distal end of the sheath 320 and circumferentially at the distal end. This sheath cutting section 321 may have a similar structure and characteristics to the aforementioned non-insulated section of the cutting loop and may similarly be electrically activated to facilitate further areas of tissue that can be cut. This outer tubular sheath 320 can be used in combination with any of the other instruments disclosed and can be used in the manner that best facilitates the valve leaflet clip removal procedure. Again, all non-insulated cutting sections 311, 312, 313 and 321 may be activated individually at separate times or all together simultaneously.

[0182] Figure 103 shows an embodiment of Figure 102 within a cardiac valve tissue model 330, which includes chordae tendineae 13 and a leaflet positioning clip 40. This figure shows an example of how instruments 320 and 316 engage with the tissue on all sides of the clip 40, in a manner positioned to cut the attached tissue structure from the clip instrument 40.

[0183] Another exemplary embodiment of the cut 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., proximal). Furthermore, the side loop portions 314, 315 are shown bent laterally outward to increase the width of the loop 350. The loop 350 may have various different insulated and uninsulated portions as shown in Figures 101-103 (i.e., several separate uninsulated portions or the entire loop is uninsulated).

[0184] Figures 105 and 106 show another embodiment of the removal device 360, which is generally similar to the removal device 100 but further includes a first cutting loop 104 and a second cutting loop 316. In some cases, it can be difficult for a physician to accurately visualize which tissues should be cut to completely remove a cardiac treatment device. Two or more loops allow for a first series of cuts to the valve tissue, and then allow for one or more second cuts (e.g., by tightening the first cutting loop) to completely remove the cardiac treatment without requiring dramatic repositioning of the loops. In contrast, it may be necessary to move, reposition longitudinally, and / or rotate a single cutting loop to completely remove the cardiac treatment.

[0185] In this embodiment, 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 further away from the basket 104. Thus, the second loop 316 can be positioned relative to the valve leaflets and / or chordae tendineae (e.g., in Figure 107, the cut 370A through the anterolateral chordae tendineae and the cut 370B through the posteromedial chordae tendineae), and the cutting sections 311, 313, and 313 can be activated to make a first series of cuts into the tissue. This first series of cuts may not cut all of the tissue, but it can cut the cutting section 104B of the first cutting loop 104, and then be activated to make one or more second cuts (e.g., along the atrial cutting section 370C of the clip 40 in Figure 107) to completely remove the remaining tissue from the cardiac treatment device 40.

[0186] Specific embodiments of the cutting loops 104 and 316 are shown in Figures 105 and 106, but any combination of the loops described herein can be used in this manner. For example, Figure 108 shows an embodiment 180 having two loops 316 of similar shape and configuration. Thus, either loop may have a different number and pattern of cuttings, and all of these cuttings may be activated simultaneously or at different times / patterns. In one example, both cutting 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 cuttings) may have its own electrical circuit (e.g., individual conductive wires) that allows independent operation from other cutting loops. Furthermore, three or four cutting loops may be used alternately. All cutting loops may be connected to the same removal catheter, or one or more loops may be connected to a catheter separated from the other cutting loops and / or basket 104. In some embodiments, one or more cutting loops may be located on the ventricular side of the valve, and one or more cutting loops may be located on the atrial side of the valve.

[0187] If the clamping loop 106 has an insulating coating along its entire length, the cutting loop 104 may be positioned directly on top of the clamping loop 106 and in contact with the loop. The cutting loop 104 may also be spaced apart from the clamping loop 106 along its longitudinal direction, such as between approximately 0 mm and approximately 15 mm.

[0188] Preferably, the internal control member 108 (best shown in Figures 11-13) is flexible enough to advance through the vascular system while having sufficient column strength to push the basket 102 and cutting loop 104 out of the outer tubular sheath 110, can efficiently deliver RF energy from the proximal handle to the cutting loop, is insulated to prevent current leakage into the blood flow, and has a good torque response so that the user can rotate the basket and loop when it is deployed in and around the valve.

[0189] In a preferred embodiment, the internal control member 108 consists of an internal control stylet joined or welded to a more flexible internal control cable, which is then joined to the tail of the cut loop conduction wire using a distal coupler. In a preferred embodiment, the internal control stylet, internal control cable, cut loop conduction wire, and distal coupler are made of the same material (e.g., a steel alloy) to enable strong welded joints and efficient current delivery throughout. The internal control cable may be a laser-cut tube, a stranded cable, a stranded cable tube, a coil, or a combination thereof. In another embodiment, the internal control cable may extend from the proximal handle to the cut loop 104 and does not require an internal control stylet.

[0190] In other embodiments, the internal control member 108 may consist of two separate wires, one connected to the clamping loop 106 and the other to the cutting loop 104. When both internal control members are located in the same single lumen of the outer tubular sheath 110, the basket 102 can first be deployed by advancing the internal basket control member distally until the basket clamping loop 106 is fully exposed. Next, the cutting loop 104 can be deployed by advancing the internal cutting loop control member distally. Each loop can be rotated, advanced, or retracted by its respective control member. This gives the operator more degrees of freedom. The heart valve treatment may first be captured or surrounded by the cutting loop 104, followed by the basket clamping loop 106 and the basket 102. The cutting loop 104 can then be closed over the leaflet tissue bridge by retracting the internal cutting loop control member. Once the cutting loop is closed over the tissue bridge, one of two steps can be performed: 1) the basket clamping wire 104 and basket 102 can be closed by retracting the internal basket control member proximal, or 2) if the cutting 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 over the atrial tissue of the heart valve treatment, the internal cutting loop control member is energized with RF power as it is retracted proximal into the external delivery sheath 110. The internal cutting loop control member delivers cutting energy only to the cutting element through the cutting loop 104.

[0191] The internal control members described above can instead be located in separate outer tubular sheaths or in separate lumens within the same sheath 110. This system can be designed so that each sheath is located at a separate orifice (i.e., on the opposite side of the heart valve treatment). Once both loops have captured the heart valve treatment, the same steps as described above follow.

[0192] The control member insulator covering the outer surface of the internal control stylet and internal control member is preferably sufficiently flexible so as not to affect the advancement of the delivery catheter through the valve orifice. Furthermore, it is desirable that the insulator be as lubricated as possible so as to minimize friction between the internal control member and the delivery catheter when the internal control member is pushed distally and deploys the basket and cleavage loop in the left ventricle. For example, this insulator may include a hydrophilic coating, a silicone coating, a Teflon-like coating, a polyolefin coating, a thermoform or thermosetting coating, or a fluoropolymer.

[0193] Returning to the basket 102, its length and diameter may depend on the size of the heart valve treatment device or clip 40. For example, the basket 102 may have a length ranging from approximately 20 mm to approximately 50 mm and a diameter ranging from approximately 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 accordingly. For example, the larger the occlusion angle with respect to the top surface across the opening of the basket 102, the larger the diameter of the basket 102 must 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.

[0194] In one embodiment shown in Figure 31, the basket 102 can be composed of multiple braided wires. The wires can be made of a shape memory material and can be braided on a mandrel of the desired basket size, and then heat-set so that the braided shape returns to the expanded basket shape after compression. The wires can be made of a shape memory material such as nitinol, or a non-shape memory material such as stainless steel. The wires may also have an insulating coating such as ETFE, polyimide, parylene, silicone, or similar materials. The advantage of a braided basket is that its behavior / performance can be changed by changing the wire diameter of the basket, the wire material of the basket, and / or the weaving density (i.e., the basket pore size) while keeping the basket diameter and length fixed. The design of the basket diameter and length is mainly determined by the size of the heart valve treatment to be removed. The size, spacing, and number of braided basket eyelets can also be adjusted and optimized. In one example, the pores 102B of the expanded basket 102 are in the range of approximately 100 microns to approximately 4 mm in diameter.

[0195] The wire size is preferably small enough to allow it to be easily folded into and unfolded from the delivery catheter during the procedure, but large enough to give the basket sufficient rigidity to open fully in the presence of chordae tendineae or other structures. The size of the pores in the basket may vary depending on the design intent, and may differ from the woven basket. Generally, the size of the pores should be smaller than any of the length, width, or height of the heart valve treatment, in order to prevent embolus formation through the basket after it has been cut and freed. Weaving a basket with very small pores may help filter and capture any debris generated during the tissue cutting process.

[0196] One advantage of coating the metal basket is to ensure that electrical energy is concentrated within the cutting element and distributed across the entire metal structure of the basket and not within the blood pool. A second advantage of the coating is that it can also reduce friction and thus facilitate the capture of the heart valve treatment within the basket. If the basket is too rough or has too many edges within the basket, the heart valve treatment may not fully fit within the basket. By adding a lubricious coating or a smooth layer to the inner surface of the capture basket, the capture of the heart valve treatment can be facilitated.

[0197] In another embodiment seen in FIGS . 32, 33, and 34, the removal catheter 150 includes a basket 152 made of a polymer such as silicone, PET, polyester, nylon, polypropylene, Kevlar, or a similar material that can be folded or pleated into a radially compressed shape. The basket 152 can be formed with a plurality of openings sized (e.g., having a diameter of about 100 microns to about 4 mm) to prevent the passage of both the valve tip clip 40 and other biological materials that can disengage from the treatment. The basket 152 can be similar in size to the aforementioned basket 102. The top opening of the basket 152 can also include a plurality of loops or passages 152B sized to allow the passage of the tightening loop 106 so that the basket 152 can be closed during the treatment.

[0198] The structure of the polymer basket 152 can be completed using braiding, meshing, weaving, knitting, or injection molding. The possibilities for the combination of basket shape and material are infinite, and only a few will be described here. It is important to select a polymer material with high heat resistance, low hygroscopicity, and durability that can withstand repeated crushing against the outer sheath. Silicone tends to best meet these performance requirements. If the basket is made of silicone, it can be molded into a basket shape as an independent component or directly onto the loop structure. When making a basket from a flat silicone sheet, it can be cut into the designed pattern and stitched onto the loop in the desired shape.

[0199] Depending on the selected material, the size and spacing of the pores 152A can be adjusted. Generally, the size of the pores can be made smaller than any of the length, width, or height of the heart valve treatment to avoid embolization through the basket after the heart valve treatment is cut. Using a basket with very small pores can help filter and capture debris generated during the tissue cutting process. By designing a basket with pores, blood can also flow through it. Minimizing the force required to pump blood (i.e., minimizing the "parachute effect") helps improve the operator's control of the basket. The polymer basket can be created with or without using eyelets. If there are eyelets as shown in the figure, they are slidably attached to the basket tightening loop. If there are no eyelets, it is securely fixed to the basket tightening loop.

[0200] Since the polymer basket 152 does not conduct electricity, other embodiments are possible where the cutting loop 104 of the removal catheter 160, as shown in FIGS. 35 and 36, also serves as a tightening loop. The basket 152 can be directly attached to the insulating portion 104A of the cutting loop 104 (alternatively, an insulating portion can be directly formed around a non-insulated wire), leaving the exposed non-insulated portion 104B for valve tip cutting open.

[0201] Similar "single-loop" embodiments are possible in other shapes and materials. For example, Figure 37 shows multiple polymer or woven filaments woven together to form a flexible basket shape and a relatively large opening (e.g., about 0.5 mm to about 4 mm). Figure 38 shows multiple polymer or woven fibers woven into a cloth basket 164 having a relatively small opening (e.g., about 0.5 mm to about 4 mm). Figure 39 shows polymer sheets sewn together to form a basket 166. In any of these embodiments, the cut loop 104 may be exposed so that the non-insulated portion 104B can cut the valve leaflets of the valve after tightening.

[0202] In other embodiments, the basket may be composed of a partially or entirely laser-cut basket. For example, Figures 40 and 41 show a plurality of vertical laser-cut ribs having eyelets arranged along their length so that a plurality of wires or polymer filaments can be braided or woven together. Figures 42 and 43 show a laser-cut basket shape that is entirely made of laser-cut shape memory metal (e.g., a tube or sheet of shape memory metal).

[0203] The advantage of laser-cut baskets is that their behavior / performance can be modified by changing the dimensions and / or cut pattern / density (i.e., basket pore size) of the tube 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 to be removed. The size, spacing, and number of 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 mold. By using a shape-memory material, the basket can be repeatedly crushed and returned to the same shape. The wire size is preferably small enough to allow it to be easily folded into and unfolded from the delivery catheter during the procedure, but large enough to give the basket sufficient rigidity to open fully in the presence of chordae tendineae or other structures.

[0204] The pore size of the basket can be modified in the laser-cut design by altering the cut pattern to achieve the desired result. For example, the pore size can vary within a range of approximately 100 microns to approximately 4 mm. Generally, the pore size should be smaller than the length, width, or height of the heart valve treatment to avoid embolus formation through the basket after the heart valve treatment is cut and freed. One of the unique advantages of laser-cut baskets is that the size and spacing of the pores can vary over the entire length of the basket. For example, the proximal opening side of the basket may have larger pores with a certain pattern density. The pore size and pattern density can become smaller and denser towards the distal end of the basket.

[0205] Any of the basket embodiments described herein may further include an outer cover that helps to collect any debris or embolic material released during the procedure. Such an outer cover may 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 a particular embodiment, the interior of the basket may have a non-conductive liner, film, or coating (e.g., silicone) on its inner surface to help prevent electrical contact with the cutting element 104.

[0206] In one embodiment, the removal catheter 100 may include a proximal handle portion 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 slot in the housing 172. The housing 172 can be connected to an outer tubular sheath 110, while the sliding member 174 is connected to an internal control member 108, which allows the user to adjust the position of the sliding member 174 with their thumb to move the corresponding internal control member 108, basket 102, and cutting loop 106 longitudinally.

[0207] Optionally, the handle 170 may also include a fluid connection port 176 (e.g., a Luer port) communicating with the interior of the internal passage of the outer tubular sheath 110, so as to deliver an electrically neutral solution (e.g., dextrose solution) to an area near the cutting loop, amplifying the tissue cutting effect and minimizing energy loss around the area to the blood pool. The amount and timing of this fluid can be determined by a physician (e.g., via a syringe) or via an electrically operated pump mechanism based on the position of the cutting loop 106 (i.e., if the cutting loop is outside the outer tubular sheath and in good contact with the desired tissue 110).

[0208] As shown in Figure 45, the handle 170 may include a locking mechanism 173 near the distal end of the housing 172 that locks the internal control member 108 in a predetermined 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 surrounding the proximal end of the internal 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 internal control member 108 so that the internal control member can slide longitudinally within the handle 170.

[0209] Figure 46 shows an embodiment of a removal catheter 100 having a current overflow hole 111 within an outer tubular sheath 110. This embodiment is most beneficial for embodiments having a single clamping and cutting loop and either a polymer or minimally conductive basket 102. As the cutting element 104 and the fixing basket 102 are retracted into the outer tubular sheath 110 and cutting of the valve leaflet tissue begins, the distal end of the outer tubular sheath 110 is closed off from the blood pool. If this occurs after the tissue has been cut, the current supplied to the cutting element 104 will no longer be transmitted to the tissue or blood, but instead may transmit heat and / or electricity through the basket 102, potentially damaging it. The current overflow hole 111 within the outer tubular sheath 110 can ensure that the cutting element 104 remains in constant contact with the blood pool even after the cutting is complete. In this way, the current chooses to flow through the blood to an opposite RF electrode attached elsewhere on the patient, as opposed to the basket.

[0210] Alternatively, the wire 113 can be attached to the internal control member 108 to ensure that the current path always involves a blood pool, even after the cutting is complete. 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 crushed inside the outer tubular sheath 110. It is also preferable that it has a very small area of ​​exposed metal at the very distal tip, with the rest being insulated. In this way, once the cutting is complete, the current chooses to flow through the lower resistance wire into the blood, as opposed to flowing through the higher resistance basket 102 (e.g., silicone).

[0211] Figures 48–53 show side views of the removal catheter 100 with the basket 102 deployed and tightened. In Figure 48, the basket 102, the tightening loop 106, and the cutting loop 104 are all positioned within the outer tubular sheath 110. As seen in this figure, these components are radially compressed to a relatively small diameter to allow them to pass through the patient's blood vessels (by remaining compressed within the outer tubular sheath, they can pass through smaller orifices and also between multiple clips).

[0212] In Figure 49, the internal control member 108 is advanced distally (e.g., via the sliding member 174) so ​​that the basket 102 begins to extend radially out of the outer tubular sheath 110. This distal movement continues until both the basket 102 and the cutting loop 104 have unfolded and fully expanded outside the sheath 110, as shown in Figure 50.

[0213] Figures 51 and 52 show that the inner control wire 108 is being pulled back, which in turn pulls back both the tightening loop 106 and the cutting wire 104, causing them to close radially. Typically, RF energy is activated during this time to cut the tissue of the valve leaflet as the cutting wire 104 closes. The RF current is deactivated when the cutting loop 104 is fully pulled inward into the outer tubular sheath 110. This can be achieved in several different ways. For example, the aforementioned sliding member 174 of the handle 170 may include a position switch that turns the RF energy on / off at a predetermined longitudinal position. Alternatively, a manual on / off switch may be included in the handle 170 or the RF power supply.

[0214] To assist in determining when to manually switch off the RF energy, a radiopaque marker can be placed at the distal end of the outer tubular sheath 110. When a physician performs tissue bridging, they look at a fluoroscopy screen. Since tissue is typically invisible in fluoroscopy, it may be useful to provide the operator with a visual indicator on the catheter 100 that indicates the tissue bridge has been severed. The internal control member 108 and the severing loop 104 are retracted into the sheath 110 during the severing process, and the radiopaque marker is positioned so that the tissue bridge is severed when the operator views the entire severing loop 104 proximal to the radiopaque marker in fluoroscopy. This is not only a useful visual indicator for the operator but also makes the procedure safer. Once the severing loop 104 has passed the radiopaque marker, the RF severing energy can be immediately terminated by the operator to prevent unintended overheating caused by applying power for longer than necessary.

[0215] Finally, the opening of the basket 102 is tightened and closed almost completely, and the position of the internal control member 108 can be arbitrarily locked in place (for example, by the locking mechanism 173 on the handle 170). The basket 102 is maintained outside the outer tubular sheath 110 and is retracted into the larger guide catheter used during the procedure.

[0216] The present invention includes different methods or approaches for removing cardiac valve treatments such as valve clips 40. For example, Figures 56–61 illustrate removal procedures that cross the atrial septum 18 and access the mitral valve 20. While exemplary access methods and procedures are described, it should be understood that they are modifiable based on known catheter access techniques. Furthermore, these access techniques can be used in any embodiment of this specification.

[0217] The mitral valve access procedure shown in Figures 56-61 may, in one embodiment, include an internal control member 108, an external tubular sheath 110, an internally operable catheter 180, and an external transseptal guide catheter 182, which can be seen separately in Figure 54 and together in Figure 55, and will be discussed further below. The three nested but independently curved catheters with axial joints allow the removal device to be positioned anywhere in the heart, regardless of size or procedural location. However, other tools, sheaths, catheters, and similar devices may be used alternatively to orient the removal catheter 100, as will be discussed later.

[0218] Referring first to Figure 56, the left atrium 12 can 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 traverse the atrial septum 18, and finally moving the guidewire into the left atrium. Next, a relatively large-diameter lateral transseptal guide catheter 182 can be advanced on the guidewire and through the atrial septum 18 so that its distal end is located in the left atrium 12. Alternatively, the transseptal guide catheter 182 can be advanced through the atrial septum 18 without using a transseptal guidewire. The lateral transseptal guide catheter 182 may have a predetermined curve or bend to help tilt it from the inferior vena cava 17 toward the atrial septum 18, if necessary.

[0219] The guide wire can be removed, and then the inner manipulable guide catheter 180 can be advanced through the outer transseptal guide catheter 182 such that its distal end is positioned within the left atrium 12. The distal end of the inner manipulable guide catheter 180 can be "manipulated" or deflected such that its distal opening is directed to the desired location on the mitral valve 20. Since the guide catheter is independent of the outer transseptal guide catheter 182, the physician can direct the inner manipulable guide catheter 180 to any position along the mitral valve 20, rotate it, advance / retract it, or change the degree of deflection while maintaining the outer transseptal guide catheter 182 in the same position.

[0220] In the example of the mitral valve 20 having the valve leaflet clip 40, the inner manipulable guide catheter 180 preferably faces either one of the two valve openings on each side of the central clip 40 (see the top view of FIG. 6). Once directed to the desired target location, the ablation catheter 100 is advanced from its distal end through the inner manipulable 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. 56.

[0221] As shown in Figures 57 and 58, the internal control member 108 is advanced distally through the outer tubular sheath 110 of the removal catheter 100, advancing the capture basket 102, the clamping loop 106, and the cutting loop 104 from the outer tubular sheath 110. Preferably, the capture basket 102, the clamping loop 106, and the cutting loop 104 are connected to the internal control member 108 such that the openings of the basket 102 and the cutting loop 104 face toward or expand toward the valve leaflet clip 40. For example, the plane 103A of the openings of the basket 102 and the cutting loop 104 can be at an angle 103C between 45 and 135 degrees (e.g., 90 degrees) with respect to the axis 103B of the internal control member 108. The internal control member 108 can rotate relative to the outer tubular sheath 110 (or alternatively, the total removal catheter 100 can be rotated), allowing the capture basket 102, the clamping loop 106, and the cutting loop 104 to rotate within the left ventricle 14. In this way, the physician can position or orient the basket 102 to a desired position directly below the valve leaflet clip 40.

[0222] Once the capture basket 102, the tightening loop 106, and the cutting loop 104 are deployed, the internal control member 108 (or alternatively, the outer tubular sheath 110) can be pulled back proximally so that the valve leaflet clip 40 is positioned inside the basket 102, as shown in Figure 59. Preferably, both the cutting loop 104 and the tightening loop 106 are positioned above the valve leaflet clip 40, that is, between the valve leaflet clip 40 and the bottom adjacent surfaces of the valve leaflets 22 and 24.

[0223] Referring to Figure 60, the internal control member 108 is pulled back proximally to partially pull back the tightening loop 106 and the cutting loop 104. This closes the top opening of the basket 102 above the leaflet clip 40 and reduces the diameter of the cutting loop 104, causing the cutting loop 104 to engage between the atrial portions of the leaflets 22 and 24 and the leaflet clip 40.

[0224] As shown in Figure 61, RF energy is applied to the cutting loop 104 as it is pulled back proximally and its diameter decreases. The non-insulated portion 104B cuts the tissue by pressing against the portion of the valve leaflets 22, 24 closest to the leaflet clip 40, thereby releasing the leaflet clip 40 from the mitral valve 20. The RF energy is turned off relative to the cutting loop 104. Preferably, the lateral transseptal guide catheter 182 has a diameter large enough to accommodate the basket 102 containing the leaflet clip 40. However, the removal catheter 100, the internally operable catheter 180, and the lateral transseptal guide catheter 182 can all be withdrawn from the patient as a single unit if necessary.

[0225] Furthermore, after the removal of the valve leaflet clip 40, it is conceivable that the prosthetic valve can be placed in the position of the mitral valve 20. If a guidewire is used during the removal procedure, it may also be used to advance and orient the valve delivery catheter for delivery and implantation of the prosthetic valve. An example of such 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.

[0226] Furthermore, after the removal of the valve leaflet clip, blood flow management devices such as spacers, catheters, balloons, or other devices may be positioned at the valve to manage blood flow across the valve until additional treatment, such as a replacement valve, can be delivered, and may be inflated at the valve's position.

[0227] Figures 62–65 illustrate another method for removing a leaflet positioning device, such as a leaflet clip 40, by a transapical approach. First, as shown in Figure 62, an incision is made in the sternum (e.g., between the manubrium and the sternum), and the transapical sheath 184 is advanced through the incision into the left ventricle 14, passing through the apex of the heart 10. The removal catheter 100 is then advanced through the transapical sheath 184 so that the distal end of the outer tubular sheath 110 extends into the left ventricle 14.

[0228] Referring to Figure 63, the internal control member 108 is advanced distally within the outer tubular sheath 110 to release and expand the basket 102 and the cutting loop 104 into the left ventricle 14. The clamping loop 106 and the cutting loop 104 preferably have a predetermined curve (e.g., a heat-set curve) that directs the top opening of the basket 102 and the opening of the cutting loop 104 toward the valve leaflet clip 40. For example, the plane between the top opening of the basket 102 and the opening of the cutting loop 104 can be in the range of 135 to 225 degrees (e.g., about 180 degrees) with respect to the axis of the internal control member 108. The internal control member 108 can be further rotated by the physician (or the entire removal catheter 100 can be rotated) to optimally align the cutting loop 104 and the basket 102 with the valve leaflet clip 40.

[0229] As shown in Figure 64, the outer tubular sheath 110 is advanced further from the transapical sheath 184 so that the leaflet clip 40 is fully positioned within the basket 102. As shown in Figure 65, the internal control member 108 is pulled back proximal to reduce the diameters of the clamping loop 106 and the cutting loop 104. As the diameters of loops 104 and 106 are reduced, the upper opening of the basket 102 is reduced, trapping the leaflet clip 40 within it. Furthermore, as the cutting loop 104 is reduced, RF energy is activated and supplied to loop 104, allowing the non-insulated portion 104B to cut the leaflet tissue just above the leaflet clip 40.

[0230] Preferably, the capture basket 102, the clamping loop 106, and the cutting loop 104 are connected to the internal control member 108 such that the openings of the basket 102 and the cutting loop 104 face toward or extend toward the valve leaflet clip 40. For example, the plane 103A of the openings of the basket 102 and the cutting loop 104 can be at an angle 103C between 25 and 135 degrees (e.g., 90 degrees) with respect to the axis 103B of the internal control member 108.

[0231] If the transapical sheath 184 has a sufficiently large diameter, the outer tubular sheath 110 can be retracted proximally, and the basket 102 containing the valve leaflet clip 40 can be withdrawn into the passage of the transapical sheath 184 for removal. If the basket 102 and valve leaflet clip 40 are very large relative to the transapical sheath 184, both the sheath 184 and the removal catheter 100 can be withdrawn simultaneously.

[0232] Figures 66 and 67 illustrate another method for removing a heart valve treatment such as a leaflet clip 40 via a transaortic approach. Referring to Figure 66, an aortic guide catheter 186 is initially placed in the aorta 11 and then 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 below the leaflet clip 40. Alternatively, the aortic guide catheter 186 may include an operable mechanism that allows deflection in different directions.

[0233] Next, the removal catheter 100 is advanced through the aortic guide catheter 186 so that the distal end of the outer tubular sheath 110 extends into the left ventricle 14 from the distal end of the catheter 186. The internal control member 108 is advanced further distal to the outer tubular sheath 110 so that the basket 102 and the cutting loop 104 are deployed, expanded, and positioned within the left ventricle 14. The openings of the basket 102 and the cutting loop 104 are either aligned or directed to face the valve leaflet clip 40. For example, the faces of the openings of the basket 102 and the cutting loop 104 can be within a range of about 300 degrees and 45 degrees (e.g., about 320 degrees) with respect to the axis of the internal control member 108.

[0234] Referring to Figure 67, the aortic guide catheter 186 is moved or (in the case of a maneuverable catheter) deflected so that the cutting loop 104 and basket 102 are positioned over the leaflet clip 40. The internal control member 108 is pulled back proximal to the inside of 110, thereby reducing the diameter of the clamping loop 106 and cutting loop 104 and closing the top opening of the basket 102. As the diameter of the cutting loop 104 is reduced, RF energy is delivered to the loop 104, allowing the non-insulated portion 104 to cut the area of ​​leaflet tissue adjacent to 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 via the aortic guide catheter 186, or all catheters can be removed simultaneously as a single unit.

[0235] The present invention also intends to use a removal catheter 100 (or any variation described herein) on the tricuspid valve 15, as seen in Figures 68 and 69. Referring first to Figure 68, the lateral tricuspid guide catheter 188 is first delivered to the right atrium 16 by either an approach through the inferior vena cava 17 or the superior vena cava 19. The tricuspid guide catheter 188 may include a fixed curve at its distal end to assist in its distal opening toward the tricuspid valve 15, or may include an operating mechanism for doing so. The medial intermediate catheter 189 may then be advanced through the lateral tricuspid guide catheter 188 to provide a better angle toward the tricuspid valve 15. For example, the medial intermediate catheter 189 may have a fixed curve toward the tricuspid valve 15, or may include an operating catheter mechanism to allow the physician to deflect the distal end of the catheter 189 toward the tricuspid valve 15.

[0236] Next, the removal catheter 100 advances through the internal intermediate catheter 189, exiting from the distal end of the internal intermediate catheter 189, entering the right atrium 16, passing through the tricuspid valve 15, and entering the right ventricle 13. Since the valve leaflet clip 40 is typically located in the center of the valve 15 (for example, as in the top view of the mitral valve in Figure 6) and forms the valve opening laterally, it is preferable that the removal catheter 100 be positioned on each side of the valve leaflet clip 40.

[0237] The internal control member 108 is advanced further distally to the outer tubular sheath 110 so that the basket 102 and the cutting loop 104 are deployed, expanded, and positioned within the right ventricle 13. The openings of the basket 102 and the cutting loop 104 are either aligned together or oriented to face the valve leaflet clip 40. For example, the plane 103A between the openings of the basket 102 and the cutting loop 104 can be at an angle 103C (e.g., about 45 degrees) in the range of about 0 to 90 degrees with respect to the axis 103B of the internal control member 108. The removal catheter 100 is pulled back proximal to the inner intermediate catheter 189, so that the cutting loop 104 and the basket 102 are positioned above and outside the valve leaflet clip 40.

[0238] The internal control member 108 is pulled back proximal to reduce the diameters of the clamping loop 106 and the cutting loop 104, thereby closing the top opening of the basket 102. As the diameter of the cutting loop 104 decreases, RF energy is delivered to the loop 104, allowing the non-insulated portion 104 to cut 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 the leaflet clip 40 can be pulled back via the internal intermediate catheter 189, or all catheters can be removed simultaneously as a single unit.

[0239] It should be understood that any embodiment of this specification can be used in accordance with the access and delivery methods described in this application. Furthermore, additional methods, such as the delivery and implantation of artificial valves (either mitral or tricuspid valves), can be used in conjunction with these access and delivery methods.

[0240] The aforementioned embodiment of the removal catheter may include a basket or similar device for capturing cardiac valve treatments such as the valve leaflet clip 40, but different capture approaches and devices are also possible.

[0241] Figures 70-72 show a removal catheter 200 for removing a cardiac valve treatment leaflet clip 40. The removal catheter 200 includes an elongated perforating member 202 for perforating the device and an external cutting catheter 204 positioned above the perforating member 202. The elongated perforating member 202 may be a wire, catheter, or similar elongated device having a pointed spiral distal end, an expandable barb, or a rotating element, so that the elongated perforating member 202 can be pressed against (and optionally rotated or expanded) the top of the leaflet clip 40 to initially engage or capture the leaflet clip 40.

[0242] As shown in Figure 71, the external cutting catheter 204 is advanced distally along the elongated perforating member 202 until its distal end contacts the upper surface of the valve leaflet. The external cutting catheter 204 can be configured to cut the valve leaflet tissue by various different mechanisms, such as mechanical (e.g., rotation or forward pressure) and / or electrosurgical cutting devices (i.e., electrical or cryotherapy). As shown in Figure 72, once released from the valve leaflet tissue, the valve leaflet clip 40 can be removed by the elongated perforating member 202.

[0243] Figures 73–75 show a removal catheter 210 similar to the catheter 200 described above, but the cutting catheter 212 also includes a gripping mechanism having two jaw members with joints connected via a joint (Figure 76). After the elongated perforating member 202 engages with the leaflet clip 40 (Figure 73), the outer cutting member 212 advances distally along the elongated perforating member 202 until it contacts the upper surface of the leaflet (Figure 74). The jaw members with joints preferably include a tissue cutting mechanism at their ends, such as a blade or an electro / cryo-electrosurgical cutting device mechanism, to allow cutting of the leaflet tissue around the leaflet clip 40. Finally, in Figure 75, the jaw members of the cutting catheter 212 move closer to each other to engage with and grip the tissue clip 40.

[0244] Figures 77–82 show another embodiment of the removal catheter 220, which is embedded in a previously positioned valve leaflet clip 40, followed by the passage of a loop-based tool 224 that seals, cuts, and removes the clip 40. In Figure 77, the loop-based removal catheter 220 includes a central push rod 227, a lateral push rod 223, and an anchor mechanism 226 connected to a pushable element 225.

[0245] Figure 78 shows an end view of the loop-base removal catheter 220, which may be circular, elliptical, multi-segmented, or a combination of these shapes and elements. The lateral rods 223 push the pushable elements 225, and the central push rod 227 applies force to the anchor mechanism 226. In Figure 79, the entire loop-base removal catheter 220 is folded to be placed within the delivery catheter sheath 221. In Figure 80, the anchor mechanism 226 is advanced into the heart valve treatment hardware (i.e., the valve leaflet clip 40) using the central push rod 227 and the pushable elements 125. In Figures 78 and 79, the lateral push rods 223 are then used to push the pushable elements 225, wrapping the loop-base removal catheter 220 completely or partially around the valve leaflet clip 40. Cutting is performed mechanically or electrically, after which the target tissue is removed.

[0246] Figures 83–88 show a removal catheter 230 that is implanted in a previously placed heart valve treatment (e.g., a leaflet clip 40), through which a tool to expand the leaflet clip 40 passes, and then the hardware is removed. In Figure 83, an operable guide catheter 231 is used to position a removal catheter 232 containing an expansion tool 234 for expanding the leaflet clip 40. The expansion tool 234 may have a return, anchor, or implantation mechanism to remove or grasp native or exogenous leaflet or tissue material from the tissue clip 40. In Figure 84, the anchor 235 is advanced and implanted. In Figure 85, the expansion tool 234 advances within the leaflet clip 40. In Figure 86, the expansion tool 235 is mechanically expanded to expand the leaflet clip 40. Expansion may be assisted by electrocharging, heating, hydraulic means, rotation, internal or external ultrasound or energy to cut the tissue from the leaflet clip 40. In Figure 89, the expansion tool 235 is closed and removed away from the valve leaflet. Figure 88 shows a similar approach using a balloon expandable element 129.

[0247] Figures 89 and 90 are cross-sectional views of a mitral valve 20 treated with a heart valve therapy including one or more chordal structures 50. The chordal structures 50 typically include chordae tendineae or strands 52 connected to the valve leaflets and the left ventricle via anchors 54. The chordae tendineae 52 may be fixed to the ventricular side of the valve leaflets 24 (Figure 89) or the atrial side of the valve leaflets 24 (Figure 90). As will be further described in the following embodiments, devices similar to those used to remove the valve leaflet clips 40 may be used to remove the chordal structures 50.

[0248] Figures 91-92 show a removal tool 240 for cutting and capturing a previously placed heart valve treatment, including chordae tendineae or chordal structures implanted in the valve leaflets. In Figure 91, this procedure is performed using the aforementioned cutting catheter 212, which can open, close, energize, and remove the hardware, as described above for other heart valve treatments in Figures 73-76.

[0249] In Figures 93-97, this procedure is carried out by passing the hardware through a loop-based tool 250 that encloses, cuts, and removes the hardware, similar to the explanation given above in Figures 77-82.

[0250] In Figures 98-100, this procedure is performed using a cutting catheter 260, similar to the above-described procedures for other heart valve treatments shown in Figures 70-72.

[0251] Furthermore, a flow limiting device can be used to limit the flow rate during any of the procedures described herein. For example, Figure 109 shows an embodiment of the removal catheter 100 of Figure 60 with an additional flow limiting device 341. This flow limiting device 341 can be positioned within the region of the valve 20 (e.g., via the valve 20) before, during, or after the removal of the clip 40 and is maintained within the valve region to manage the patient's blood flow by limiting it. The flow limiting device 341 can be any flow limiting device known to those skilled in the art, such as a balloon, a covered stent, or a catheter, but is not limited to these. Any or all of these embodiments are configured, either by themselves or in combination with a valve structure, to occupy or have the ability to expand to occupy a clinically appropriate space for managing blood flow. The flow limiting device 341 can be introduced independently via delivery catheters 342 and 343, as shown herein. Furthermore, the flow limiting device 341 can be integrated into a delivery mechanism such as an internally operable catheter 180. Alternatively, the flow limiting device 341 could be, but is not limited to, a delivery system for other treatments, such as heart valves.

[0252] Maintaining good mechanical contact or force between the valve leaflet tissue and the cutting element (e.g., cutting wire 104) can be useful when performing the cutting procedure described herein, especially when RF energy is used as the mechanism for performing the cutting. This contact or force can be important in preventing the electrodes of the cutting element / loop from being exposed to large amounts of blood.

[0253] When using constant-power generators such as many commercially available RF energy generators, the generator typically perceives a low impedance (e.g., 0-300 ohms) when the cutting element is almost entirely exposed to the patient's blood. This low impedance may prevent sufficient voltage from being obtained for tissue cutting. In such situations, some RF energy generators increase the current to maintain a constant power level.

[0254] In contrast, if the cutting element is firmly pressed against the patient's tissue and is hardly exposed to the patient's blood, the generator perceives it as having a relatively high impedance (e.g., over 300 ohms) or higher resistance to current. This higher resistance may cause the generator to increase the voltage output to maintain a constant power. Once the voltage reaches a certain level, the tissue cutting process begins and continues as long as the cutting element remains in contact with the target tissue.

[0255] By utilizing this phenomenon, electrosurgery becomes possible within the heart and the patient's blood pool. Therefore, in the present invention, it may be useful to provide a mechanism that generates and / or assists in maintaining pressure or force between the cutting element and the target tissue.

[0256] Generally, when considering the removal of an implanted valve clip 40, it may be useful to consider several factors to ensure sufficient mechanical force between the transection element and the target valve leaflet tissue. Specifically, these include 1) the length of the valve leaflet tissue inserted into the arm of the valve clip 40, 2) the chordae tendineae extending around the valve clip 40, and 3) the use of multiple valve clips 40, including their spacing and positional angles.

[0257] Furthermore, there are at least four different scenarios for removing the valve clip. Specifically, these are: 1) when the severing loop is tightened on the atrial side of the valve clip 40 without requiring any further “counteracting force” against the clip 40 (as described in previous embodiments / methods of this specification); 2) when it is useful or necessary to apply a counteracting force to the valve clip 40 to stretch the tissue so that the severing loop can be tightened on the atrial side of the valve clip 40; 3) when a counteracting force is useful or necessary, and the severing loop must first sever a portion of the leaflet tissue before it can be tightened on the atrial side of the valve clip 40; and 4) when a severing snare is used to substantially release the engaging tissue from the clip 40, making it easier to engage the severing loop and basket.

[0258] In the first scenario, the cleavage loop and basket may be placed on the valve clip 40 as described herein, and the cleavage loop may be clamped on the tissue bridge without the use of any other instrument, such that the cleavage loop is positioned on the atrial side of the valve clip 40. This technique is described herein. By clamping the cleavage loop in this manner, the cleavage element is firmly pressed against the tissue and moves across the entire tissue bridge as it is drawn into the delivery catheter.

[0259] In the second scenario, some method is provided for pushing or pulling the valve clip 40 when retracting or tightening the cleaved loop. This counterforce assists in stretching the tissue inward / toward from the left ventricle 14 and away from the direction in which the cleaved loop is being pulled, so that the cleaved loop can be positioned on the atrial side of the valve clip 40 and tightened. Applying this counterforce may be useful, and may even be necessary, when relatively long leaflet tissue is inserted into the arms of the clip 40, when multiple clips 40 are implanted (especially when the clips 40 are close together), when the leaflets are too flexible, when the leaflets are too rigid, or when a relatively large tissue bridge has been previously created.

[0260] In the third scenario, the opposing force stabilizes the valve clip 40 and the valve leaflet, helping to firmly pull the cutting loop to the edge of the valve leaflet. Once firmly pressed against the valve leaflet tissue, the initial cut can be made by pulling the cutting loop toward the atrial side of the valve clip 40, and then the final cut can be completed by tightening the cutting loop.

[0261] In the fourth scenario, removal of the engaged tissue may be necessary to facilitate snare engagement and provide the snare with a counterforce to stabilize the valve clip.

[0262] In these scenarios, there are several embodiments and methods that can be used to generate a counterforce away from the left atrium 12 and towards / into the left ventricle 14.

[0263] In one example, a maneuverable catheter 180 for advancing a cutting and recapture catheter may be used to push the valve leaflets 22, 24 and valve clip 40 to generate a counterforce toward the left ventricle 14. For example, the distal edge of the distal opening can be positioned relative to the valve leaflets and / or valve clip 40.

[0264] As shown in Figure 142, in another example, the valve clip 40 can be pressed using a compression catheter 470 from the left atrium side toward the left ventricle. A slender standard catheter or a maneuverable catheter may be used, or the catheter 470 may be further provided with a dedicated distal end portion 472 to assist in pressing or engaging with the valve clip 40. For example, the distal end portion 472 may be selectively expandable (e.g., a balloon or expandable mesh structure) that can expand to better contact the valve clip 40. Alternatively or further, the distal end portion 472 may have a blunted distal end. Alternatively or further, the distal end portion 472 may be configured to mechanically contact the valve clip 40 or the valve leaflet tissue immediately adjacent to the valve clip 40. For example, devices and mechanisms shown in Figures 70 to 100 can be used to make contact with the valve clip 40 or adjacent tissue.

[0265] 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 cutting loop can be positioned between the atrial side of the valve clip 40 and the valve leaflets 22, 24. Finally, the cutting loop (e.g., any embodiment described herein) can be activated to cut the valve leaflet tissue.

[0266] In yet another example, the valve clip 40 can be pulled further into the left ventricle 14 from its current position to generate a counteracting force, thereby positioning the severing loop and enabling tissue severing as described above.

[0267] Figures 110 and 111 show one embodiment of a removal system 400 that generates a counteracting force by pulling a valve clip 40 into the left ventricle 14, and comprises both a cutting and capture catheter 403 and a separate snare catheter 401 (or, alternatively, a separate cutting catheter and a separate capture catheter). The snare catheter 401 can be used to first grasp the valve clip 40 and then pull it further into the left ventricle 14, while the cutting and capture catheter 403 can be used to cut the valve leaflets 22 and 24 and capture the valve clip 40. This method can also be used for other valves such as the tricuspid valve.

[0268] The cutting and retrieval catheter 403 is generally similar to the embodiments described above and may include any of the modifications described above. For example, the cutting and retrieval catheter 403 may include a basket 102 and a cutting loop 404 connected to an elongated inner control member 108 that moves all components in and out of the tubular jacket or sheath 110.

[0269] As is most commonly seen in Figures 112 and 113, the basket 102 may include a basket tip 414 at its distal end. The basket tip 414 can serve one or more of the following purposes. First, the basket tip 414 can connect to or accommodate the ends of the wires that make up the basket 102. In one example, the basket tip 414 has a cylindrical wall with a plurality of openings 414B through which the wire ends pass, thereby preventing the wire ends from fraying or injuring the patient. The wire ends can be tied, welded, or fixed within the basket tip 414. Alternatively, the wire ends can be welded or melted together with the basket tip 414 without requiring openings 414B. The basket 102 may be woven from a single wire, in which case there may be only two openings 414B. It may also be woven from multiple wires, in which case there may be multiple openings 414B (for example, two for each wire).

[0270] Secondly, the basket tip 414 has a non-invasive distal end shape 414A that helps prevent the patient's internal tissues from being injured by the basket tip 414. For example, the non-invasive distal end shape 414A may be spherical, round, elliptical, or conical. This basket tip 414 can also be used in any other embodiment of this specification.

[0271] Returning to Figures 110 and 111, the cutting and capture catheter 403 is constructed similarly to the previously described embodiment and further comprises a cutting element or loop 404 that can be used similarly. However, this cutting loop 404, like the cutting loop 350, has a saddle shape. That is, the cutting loop 404 has sides that form a valley shape that slopes or curves distally downward and then proximal upward. This shape is desirable because, as the cutting loop 404 is retracted proximal into the outer sheath 110, the loop 404 can maintain a desirable cutting angle with respect to the rest of the catheter 403. For example, if the cutting loop 404 forms a right angle perpendicular to the internal control member 108, the angle of the loop 404 may tend to become downward as its right-angle joint is retracted into the outer sheath 110. On the other hand, the curved or saddle shape helps to maintain the end of the loop 404 within a desired vertical range when retraction occurs. This approach can be particularly useful when the electrodes of the cutting loop 404 are located on the opposite side from the internal control member 108 of the loop. This cutting loop 404 can also be used in any of the embodiments described herein.

[0272] The snare catheter 401 includes a snare loop 420 connected to the distal end or vicinity of an internal control member 418 (similar to member 108) that moves longitudinally within the outer tubular jacket or sheath 416. This allows the snare loop 420 to be moved in and out of the sheath 416 by the internal control member 418. The outer tubular sheath 416 may have an opening at the bottom, similar to the sheath 110, and may include a tip member 422 having an opening in the side wall extending into the internal lumen of the sheath 416.

[0273] If necessary, the snare loop 420 may be equipped with the aforementioned cutting elements (e.g., an RF electrode near the tip) that engage with the tissue surrounding the clip, at least partially cutting the tissue to facilitate the initial capture and removal of the valve clip 40. Further cutting and capture procedures can then be performed. At least partial removal of the engaged tissue performed in this initial stage may be necessary to facilitate engagement of the snare loop 420 and to allow the snare loop 420 to provide a counterforce to stabilize the valve clip 40. For example, a channel or valley can be cut into the tissue surrounding the valve clip 40, thereby allowing the snare loop 420 to engage more firmly with the valve clip 40. Figures 145 and 146 show an example of such a configuration, which includes an RF electrode 421 at the far end of the snare loop 420 in addition to the RF electrode 405 at the far end of the cutting loop 404. However, any type of cutting element may be used.

[0274] The snare loop 420 can have a variety of different shapes configured to grip the valve clip 40. For example, Figures 114 and 115 illustrate a “saddle shape” or arc shape loop (i.e., sides that curve distally downward and then curve upward and connect to each other to form an arc or concave shape) similar to the cut loop 404. The curved shape prevents 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 end angle is upward, so when the loop 420 is retracted, its angle becomes distally downward. However, because the distal end is curved proximal, the distal angle of the loop 420 is not sufficient to dislodge the loop 420 from the valve clip 40. In other words, loop 420 is curved sufficiently proximal so that its distal end does not extend beyond the distal end of snare catheter 401.

[0275] In another example shown in Figure 116, the snare loop 424 may have an overall circular shape and may optionally have a radially outward-extending recessed or curved section 424A on the opposite side of the outer sheath 416. Although a single notch or recess 424A is illustrated in the figure, there may be multiple sections 424A, either partially or entirely, around the snare loop 424.

[0276] The snare loop 424 has a shape-memory property that allows it to connect to the internal control member 418 at approximately 90 degrees. In some cases, as the 90-degree bent portion is drawn into the snare catheter 401, the loop 424 may tilt or bend downward, potentially causing the loop 424 to detach from the valve clip 40. On the other hand, the saddle-shaped snare loop 420 has a distal / downward arc curve, which helps maintain the original orientation of the loop 420 even when it is drawn into the snare catheter 401, resulting in better retention of the loop 420 on the valve clip 40.

[0277] The snare loop 420 may have further features to grip the valve clip 40 more firmly. For example, as seen in the snare loop 420 shown in Figures 114 and 115, a friction coating or friction sleeve may be placed on part or the entire snare loop. In another example, as seen in Figure 117, a number of relatively small protrusions 426A (rounded ridges, sharp teeth, or similar shapes) may be placed on part or the entire radially inner surface / side of the snare loop 426. In yet another example, the snare loop may be constructed from a wire coil and may be configured in either a compressed configuration 428A (Figure 118) or a longitudinally expanded configuration 428B (Figure 119). This allows for varying levels of texture, which can enhance the grip of the loop on the valve clip 40. These different loop shapes and friction engagements can be mixed and adapted with each other and with any of the embodiments described herein.

[0278] Although the snare catheter 401 and snare loop 420 were previously described as being used to grasp the valve clip 40, they can also be used for other purposes. For example, they can be used to image other tissues. In some cases, it may be desirable to remove calcified nodules within the valve leaflets to facilitate valve placement. They may also be used to capture and remove valve leaflet tissue to facilitate flow after replacement valve insertion. They may also be used to remove chordae tendineae to facilitate valve movement. In this regard, the snare loop 420 can be used to grasp such tissue while the cutting loop 404 cuts it. However, it may also be useful to provide a cutting element (e.g., an RF electrode) on the snare loop 420 to assist in the initial cutting of such tissue.

[0279] The snare catheter 401 may further include a tip member 422 at the distal end of the outer tubular sheath 416, as is most commonly seen in Figures 120 and 121. The tip member 420 can 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. Since the valve clip 40 tends to have a generally conical or "V" shape, as previously shown herein, the tightening snare loop may have a tendency to squeeze out of the valve clip 40 when tightened. This tendency to slip out may increase if the snare loop 420 is positioned at an elevation angle with respect 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 (for example, without the tip member 422), the angle of the snare loop 420 increases relative to the axis as it is pulled into the outer tubular sheath 416, and it may slip out of the valve clip 40.

[0280] In contrast, the tip member 422 includes an opening 422A that penetrates its side wall, and a slope or curved surface 422B configured to guide the snare loop 420 that emerges from the opening 422A at an angle approximately perpendicular to the axis of the outer tubular sheath 416 and the axis of the valve clip 40.

[0281] Furthermore, the tip member 422 may have features that assist in engagement and / or friction with the valve clip 40, thereby allowing the snare loop 420 to tighten the valve clip 40 against the tip member 422 and preventing the valve clip 40 from slipping off the snare loop 420. In the examples of Figures 120 and 121, the shape of the opening 422A may have relatively acute or steep angles around it to assist in pushing it into the valve clip 40 and maintaining its position.

[0282] In the example shown in Figure 122, the proximal channel 422C and distal channel 422D extend from the main opening 422A, providing additional regions with acute or steep angles that extend over longer distances in the longitudinal direction. In the example shown in Figure 123, the tip member 422 may have a plurality of ridges or grooves 422E on its surface adjacent to the opening 422A and / or channels 422C, 422D. These ridges or grooves 422E may be relatively linear and circumferentially oriented relative to the opening 422A and / or channels 422C, 422D, or they may have different patterns such as wave shapes or zigzag patterns. In the example shown in Figure 124, a plurality of spikes, hooks, or similar sharp shapes may extend from the periphery of the main opening 422A or other nearby locations. Any combination of these engagement features can be used together to provide a surface that can better engage the valve clip 40 upon contact.

[0283] Furthermore, the snare catheter 401 may include a handle 440 configured to control and retract the internal control member 418, and consequently the snare loop 420. Specifically, the handle 440 allows a predetermined limited amount of force to be applied to the snare loop 420, while also allowing the snare loop 420 to be locked in place or with force at a desired level. This makes it possible to grip the valve clip 40 relatively firmly without requiring sufficient force to damage the catheter 401, and this gripping force can be maintained throughout the procedure with little to no handling of the handle 440 during the procedure.

[0284] The handle 440 may have another possible mechanism for controlling and locking the position / force of the snare loop 420. An example of such a mechanism is shown in Figures 125 and 126, which has an outer housing 442 formed in a generally cylindrical shape and a knob 448 (i.e., on the right side in the figures) located at the proximal end of the housing 442 and configured to be pulled out proximal to the housing 442. When the knob 448 is pulled out proximal to the housing 442, the internal control member 418 is also pulled proximal to the housing 442, and the snare loop 420 is pulled proximal to the opening of the tip 422.

[0285] The force applied to the knob 448 when it is pulled out is limited or resisted by a spring 450 located in the housing 442. The spring 442 can be connected to either an internal control member 418 or the distal portion 440 of the knob 448, and to the inside of the housing 442, so that when the knob 448 is pulled proximal, the spring 450 can be compressed or expanded to generate a stronger resisting force. Depending on the configuration of the spring 450 (e.g., size, initial compression, spring constant, and similar aspects), the force applied by the spring 450 can be optimized so that a predetermined constant tension is applied over the entire length to which the knob 448 can be pulled, or so that the tension increases as the knob 448 is pulled further proximal.

[0286] The handle 440 may also include a locking mechanism capable of locking the position of the internal control member 418 relative to the housing 442 and the outer sheath 416. In this example shown in Figures 125 and 126, the locking mechanism comprises a longitudinal groove 444 extending along at least a portion of the length of the housing 442. The tracking peg 446 is fixed to the internal control member 418 and is positioned at least partially within or through the groove 444. When the knob 448 is pulled back to the proximal side, the tracking peg 446 moves along the length of the groove 444. When the internal control member 418 reaches the desired position, the knob 448 can be rotated to move the tracking peg 446 laterally relative to the length of the groove 444 to one of a plurality of branch grooves. Preferably, these branch grooves are shaped to retain the position of the tracking peg 446, and thus the position of the internal control member 444, when the user releases the knob 448. For example, the branch groove can be tilted somewhat distally so that the tracking peg 446 within the branch groove is held in place by the distal force of the spring 450, thereby releasably locking the internal control member 418.

[0287] The handle 440 also includes a port 452 that communicates with the internal and external sheath 416 of the handle housing 442. This port 452 can be used to supply saline solution, contrast agent, or equivalent fluid during the procedure.

[0288] Furthermore, the handle 440 may be electrically connected to the RF generator and the snare loop 420 so as to supply energy to the cutting snare 420 during the procedure (if the snare loop includes an RF electrode or similar cutting element). As mentioned above, in some situations it may be useful for the snare loop 420 to include a cutting element that cuts at least a portion of the tissue surrounding the valve clip 40, or other cardiac valve therapeutic devices, so that the snare loop 420 engages better with the valve clip 40.

[0289] Generally, it is desirable that the same delivery catheter (e.g., the operable catheter 180) contains both the cutting / recapture catheter 403 and the snare catheter 401, and that they are delivered via this delivery catheter. However, depending on the specific procedure, the cutting / recapture catheter 403 and the snare catheter 401 may be delivered separately via independent delivery catheters, or without using any overlapping catheter.

[0290] Figures 127–130 illustrate an exemplary technique using a removal system 400, which includes a cutting and extraction catheter 403 and a snare catheter 401. While a specific removal system 401 is illustrated and described herein, variations of this procedure are also intended, including the use of different embodiments described herein.

[0291] First, a delivery catheter (e.g., a maneuverable delivery catheter 180) including a cutting and retrieval catheter 403 and a snare catheter 401 is delivered to the left atrium 12 of the patient's heart. Generally, it is desirable that the tip of the catheter 180 is first delivered to the left ventricle 14 via the valve leaflets 22, 24. This can be useful in preventing either the cutting and retrieval catheter 403 or the snare catheter 401 from becoming entangled with any of the chordae tendineae extending from the vicinity of 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 can be useful in forming a generally smooth surface that will not "get stuck" or snag when passing through the valve leaflets 22, 24 or nearby chordae tendineae.

[0292] Next, the cutting and retrieval catheter 403 and the snare catheter 401 are brought out of the catheter 180 and delivered into the left ventricle 14. Initially, the opening 422A of the tip member 422 is facing 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 proximal so that the snare loop 420 surrounds the valve clip 40, as shown in Figure 127.

[0293] During this time, the basket 102 and the cutting loop 404 may be in a different position from the snare loop 420, or in a position in the opposite direction of rotation, and / or positioned distal to the snare loop 420.

[0294] Referring to Figure 128, the snare loop 420 tightens or constricts around the valve clip 40 until the valve clip 40 is pressed against the tip member 422. This can be achieved by retracting the internal control member 418 proximal via the handle 440 (for example, by pulling back the knob 448 and locking its position in the slot 444). If not yet aligned, the cutting loop 404 and basket 102 are aligned perpendicularly to both the valve clip 40 and the snare catheter 401.

[0295] As shown in Figure 129, the snare catheter 401 is advanced distally to generate a counterforce that further pulls the valve clip 40 into the left ventricle 14. The severing and recapture catheter 403 is retracted proximal (simultaneously or simultaneously with or before the counterforce is generated) so that the severing loop 404 is positioned 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 almost completely around the valve clip 40 and the distal portion of the snare catheter 401 (e.g., the snare loop 420 and the distal tip 422).

[0296] Referring to Figure 130, both the constriction loop 106 and the cutting loop 404 are constricted or reduced while maintaining a counterforce from the snare catheter 401. As previously mentioned, this counterforce allows for good contact between the electrode of the cutting loop 404 and the valve 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 cutting and capture catheter 403 and the snare catheter 401 are removed from the patient, at least partially retracted into the delivery catheter 180. When the cutting and capture catheter 403 and the snare catheter 401 are retracted into the delivery catheter 180, the distal end / opening of the delivery catheter 180 may remain in the left atrium 12 or be retracted into the left ventricle 14.

[0297] In a scenario where the delivery catheter 180 is returned to the left ventricle 14, and then the severance / recapture catheter 403 and snare catheter 401 are retracted, the chordae tendineae of the valve may obstruct the return of the delivery catheter 180 to the left ventricle 14. For example, the distal end of the delivery catheter 180 is not sufficiently tapered and may "get caught" on the chordae tendineae.

[0298] One solution to this problem is to provide a chordal dilator that can be partially positioned at the distal opening of the delivery catheter 180 as it passes through the valve leaflets 22, 24 and the chordae tendineae. Such a chordal dilator has a tapered and / or inclined distal surface, and its radial size can be such that it covers most or all of the opening of the delivery catheter 180.

[0299] An example of the chordae tendineae dilator 432 is best seen in Figures 134 to 137. In this embodiment, the chordae tendineae dilator 432 includes a body having a base surface 432D with a bias angle (i.e., an edge that forms an angle such as approximately 45 degrees with respect to the vertical axis of the dilator 432). Furthermore, the base surface 432D may be rounded or slightly conical in shape to facilitate transfer to the delivery catheter 180. If necessary, the chordae tendineae dilator 432 may also have a top surface 432C of a similar shape, which may be useful for diverting the chordae tendineae in both directions for either the mitral valve or the tricuspid valve.

[0300] The chordae tendineae dilator 432 has two passages 432A and 432B, one passage 432A accommodating a snare catheter 401 and the other 432B accommodating a cut-and-recapture catheter 403. Alternatively, the chordae tendineae dilator 432 may have only a single passage accommodating only one of the snare catheter 401 or the cut-and-recapture catheter 403. In either case, it is preferable that each catheter within the passage be rotatable during the procedure. Furthermore, one of the passages may have a "C" shape (i.e., a shape that does not completely enclose the catheter) so that one end of the catheter can be separated from the chordae tendineae dilator 432. If necessary, the chordae tendineae dilator 432 may include one, two, or more radiopaque markers 432E. For example, the radiopaque marker 432E may be positioned on the circumferentially opposite side of the chordae tendineae expander 432, or it may extend at least partially between the proximal and distal ends of the chordae tendineae expander 432.

[0301] If the user wishes to move the delivery catheter 180 to the left ventricle and capture the snare catheter 401 and / or the cut-and-recapture catheter 403, the snare catheter 401 and / or the cut-and-recapture catheter 403 are moved relative to the delivery catheter 180, as shown in Figure 135, and the chordae tendineae dilator 432 is partially positioned at the distal opening of the delivery catheter 180. The delivery catheter 180, snare catheter 401, and cut-and-recapture catheter 403 are then all advanced distally until the distal end of the delivery catheter 180 is located within the left ventricle 14.

[0302] Alternatively, the chordal dilator 432 may be configured to connect only to the snare catheter 401 and the cutting / recapture catheter 403 without having a specific surface for chordal dilation. In this regard, the chordal dilator 432 does not need to be used for chordal dilation purposes and is primarily used to maintain the two catheters parallel to each other, and is useful for achieving the desired alignment while the procedure is being performed.

[0303] The chordae tendineae expander 432 may alternatively have three passages. For example, one passage 432A accommodates the snare catheter 401, another passage 432B accommodates the cutting and recapture catheter 403, and the third facilitates the passage of the guidewire. The chordae tendineae expander 432 can also be used to align the snare, cutting loop, and basket in the relative axial direction. The position of the other members relative to the chordae tendineae expander 432 changes the length of the arms of the free members, thereby controlling the distance between members and the angle of the members' axes.

[0304] While the snare catheter 401 was previously described as being used to grasp the valve clip 40, it can also be used for other purposes. For example, it can be used to grasp or capture a guidewire or Fogarty Balloon during a procedure (e.g., a transapical approach), which is useful for withdrawing these components through the target valve and preventing them from becoming tangled or caught.

[0305] As previously stated, the removal system 400 is delivered via a transeptal guide catheter 182 or a similar catheter. However, the removal system 400 can be further configured to have a guidewire pathway or passage so that it can be delivered onto a guidewire 430. The guidewire allows for more delicate force and stiffness transfer to the tissue when providing the removal system, ensuring safe delivery to various anatomical structures. Figures 131-133 show an example of a removal system 400 having such a guidewire passage. Specifically, the guidewire passage extends from the proximal opening to the outer sheath 416 of the snare catheter 401, through the opening of the distal tip member 422, through the basket 102, and finally through the passage at the tip of the basket 414.

[0306] Furthermore, other paths are possible for the guidewire 430. For example, Figure 138A shows a guidewire 430 extending outside the basket 405 and into a passage that opens near the outer top and bottom of the basket tip 415, allowing the guidewire 430 to pass through. In this example, the guidewire 430 does not pass inside the basket 405. Alternatively, as shown in Figure 138B, the guidewire 430 may pass through one of the meshes of the basket 405, enter an internal opening to the passage at the basket tip 415, and extend distally from the basket tip 415.

[0307] The guidewire 430 may extend proximal only through the operable catheter 180, as shown in Figure 138A, or it may extend proximal through either the snare catheter 401 or the cutting / recapture catheter 403. Alternatively, the guidewire 430 may extend proximal outside the operable catheter 180, snare catheter 401, or cutting / recapture catheter 403, except for the basket tip 415, as shown in Figure 138B.

[0308] Alternatively, as shown in Figure 139, the basket tip 415 may include a guidewire-like pigtail or curved wire 431 that is attached distally to and extends from the tip 415 to assist in passing through the valve and to avoid damaging different structures of the heart.

[0309] Using a guidewire 430 to advance the removal system 400 may make it easier to pass through valves with smaller openings, which are particularly common in valves with multiple valve clips 40 implanted. Moving along the guidewire 430 may make it easier to remove two valve clips 40. For example, a catheter with a cutting loop 420 can be advanced along the guidewire 430 and used to cut the leaflet tissue between the two valve clips 40, thereby separating the two clips 40 from each other, and then sequentially capturing them via a continuous removal system 400.

[0310] Regarding sequential removal, this procedure may include placing an operable catheter 180 in the left atrium, moving a guidewire 430 through the target opening of the valve, feeding a cutting / removal catheter 403 onto the guidewire 430, removing the guidewire 430, cutting and removing the valve clip 40 using the cutting / removal catheter 403, removing the cutting / removal catheter 403, moving the guidewire 430 again through the target opening of the valve, and repeating the removal process. If the operable catheter 180 is large enough to completely remove the valve clip 40, it may be kept in place after the removal of the first valve clip 40; otherwise, the operable catheter 180 can be removed and a second operable catheter 180 can be placed.

[0311] Furthermore, in some embodiments and procedures, it is desirable that the cutting and extraction catheter 403 includes a basket 460 that can be expanded or stretched from a longitudinally compressed configuration. This allows different sized valve clips 40 to be accommodated in a basket 460 of the same size without requiring multiple baskets of different sizes, and also allows the valve clips 40 to be "covered" by the snare catheter 401. For example, Figure 140 illustrates a basket 460 in a longitudinally compressed configuration, and Figure 141 illustrates a basket 460 in an expanded configuration.

[0312] The longitudinally stretchable function of the basket 460 can be achieved in several different ways. For example, the basket 460 can be braided or woven from one or more wires made of a shape memory material (e.g., Nitinol) and then heat-set into a compressed configuration (Figure 140). Instead of, or in addition to, heat-setting, the braided pattern may be configured to bias, or at least facilitate, the basket 460 as a whole into a compressed configuration. Instead of, or in addition to, the basket 460 may include a longitudinally elastic tether or elastic outer cover, thereby biasing the basket 460 into a compressed configuration. Alternatively, the wires of the basket 460 may be made of an extensible elastic material. In an alternative embodiment, one or more of the supports / wires of the basket 460 may be coiled to form a spring. In yet another alternative embodiment, the basket 460 may be kept in a compressed configuration by a plurality of pull wires connected to the basket 460 and the proximal end of the device closer to the user, and may be released as appropriate to increase the diameter and / or length of the basket 460 on the proximal side.

[0313] The baskets described herein (e.g., basket 102 or 460) have generally been shown having a cylindrical, expanded shape. However, other basket shapes are also possible. For example, Figure 143A shows basket 102' having a generally conical shape. As an example, the expanded basket shape is tapered from about 30 mm to about 6 mm. As seen in Figure 143B, when partially positioned outside the operable catheter 180, the tapered shape forms a non-invasive, smooth shape without large edges. This prevents the operable catheter 180 from getting caught or stuck as it passes through the valve, valve leaflets, and chordae tendineae. This shape also makes it easier to load the basket into the operable catheter 180 or other catheters.

[0314] To capture the valve clip 40 or other cardiac therapeutic device, a basket 102 is desirable, but the basket 102 can also be omitted from the cutting and capture catheter 403, as shown in Figure 144. In such a device, the cutting loop 404 can move proximal over the clip 40 and snare loop 420, and when activated to cut the desired valve tissue, the snare loop 420 (and the possible clip engagement features described above) can be used to grasp the valve clip 40. The snare loop 420 maintains its grip on the valve clip 40, and the clip 40 can be pulled proximal away from the patient.

[0315] This specification and drawings include many different embodiments and features of removal devices and methods of use thereof. While features or techniques may be described in relation to a particular embodiment, it is the applicant's intention that features shown in one embodiment can be incorporated into other embodiments. In other words, any of the features described herein can be mixed and adapted to one another, and therefore the claims should not be limited or restricted to the embodiments discussed and described herein.

[0316] As used herein, the terms “substantially” or “generally” refer to the complete or nearly complete range or extent of an action, feature, characteristic, state, structure, item, or result. For example, an object enclosed “substantially” or “generally” may mean that the object is completely enclosed or nearly completely enclosed. The exact permissible deviation from absolute completeness may depend on the specific circumstances. However, generally speaking, proximity to completeness will generally result in the same overall outcome as absolute and overall completeness would be obtained. The use of “substantially” or “generally” is equally applicable when used in a negative implication referring to the complete or nearly complete absence of an action, feature, characteristic, state, structure, item, or result. For example, an element, combination, embodiment, or composition that “substantially does not contain” or “generally does not contain” a certain component or element may actually contain such element unless there is a generally measurable effect.

[0317] As used herein, the terms “one embodiment” or “example” mean that certain elements, characteristics, structures, or features described in relation to this embodiment are included in at least one embodiment. The phrase “in one embodiment” appearing in various places in the specification does not necessarily refer to the same embodiment.

[0318] Where used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having,” or any other variation thereof are intended to include non-exclusive inclusion. For example, a process, method, article, or apparatus that includes a list of elements is not necessarily limited to those elements alone, and may include other elements that are not expressly listed in or inherent to such process, method, article, or apparatus. Furthermore, unless explicitly stated otherwise, “or” means inclusive or not exclusive or. For example, condition A or B is satisfied by one of the following: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0319] Furthermore, the use of “one (a)” or “one (an)” is used to describe the elements and components of the embodiments herein. This is done simply for convenience and to give a general meaning to the description. This description should be read as including one or at least one, and the singular form also includes the plural form unless it is clear that it has a different meaning.

[0320] Furthermore, the figures illustrate preferred embodiments for illustrative purposes only. Those skilled in the art will readily recognize from this description that alternative embodiments of the structures and methods described herein can be used without departing from the principles described herein.

[0321] While the present invention is described in relation to specific embodiments and uses, those skilled in the art can, in light of this teaching, generate additional embodiments and modifications without departing from or exceeding the spirit of the claimed invention. Accordingly, it should be understood that the drawings and description herein are provided as examples to facilitate understanding of the invention and should not be construed as limiting its scope.

Claims

1. A system for removing heart valve treatment devices, A cutting catheter comprising: a first elongated control member; and a cutting loop fixed to the distal end of the first elongated control member and configured to cut tissue; A snare catheter comprising a second elongated control member and a snare loop fixed to the distal end of the second elongated control member, A system characterized in that, with the snare loop engaged around the heart valve treatment device and the heart valve treatment device being grasped, the cutting loop is movable from a position distal to the snare loop to a position passing proximal over the snare loop and the heart valve treatment device to reach the proximal side of the snare loop, and at this proximal side of the snare loop, the cutting loop can be activated to cut valve tissue.

2. The system according to claim 1, wherein the snare loop has a saddle shape in which the side surface of the snare loop is curved to form a valley shape.

3. The system according to claim 1, wherein the cutting loop has a saddle shape in which the side surface of the cutting loop is curved to form a valley shape.

4. The system according to claim 1, wherein the cutting loop further comprises one or more separate non-insulating portions that deliver cutting energy to the tissue when in contact with the tissue.

5. The system according to claim 1, wherein the snare loop further comprises a cutting element configured to cut the tissue.

6. The system according to claim 1, wherein the snare catheter further comprises an opening penetrating its side wall, through which the snare loop is movable, and the snare loop is directed at an angle approximately perpendicular to the axis of the snare catheter.

7. The system according to claim 1, further comprising: 1) a passage in which either the snare catheter or the cutting catheter is disposed; or 2) a chordal dilator positioned partially outward from the distal opening of the delivery catheter, wherein the system comprises either a first passage in which the snare catheter is disposed and a second passage in which the cutting catheter is disposed, and the chordal dilator has a rounded, conical, or biased base.

8. The system according to claim 1, wherein the cutting loop has a first position distal to the snare loop and a second position proximal to the snare loop.

9. The system according to claim 1, wherein the snare loop comprises a single recess extending radially outward from a circular shape, or a plurality of recesses partially or entirely arranged around the snare loop.

10. The system according to claim 1, wherein the snare loop comprises a plurality of protrusions located on part or all of the radial surface on the inside of the snare loop.

11. The system according to claim 1, wherein the snare loop further comprises an electrical insulator.

12. The system according to claim 11, wherein the snare loop further comprises a coating or sleeve on part or all of the snare loop.

13. The system according to claim 11, wherein the cutting loop comprises a first metal that conducts electric current and a second metal that is a shape memory metal.

14. The system according to claim 13, wherein the first metal comprises stainless steel, copper, or silver, and the second metal comprises nitinol.

15. The system according to claim 14, wherein the first metal is electrically insulated from the second metal.

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