Clip delivery catheter with spiral multi-tubular extrusion section for improved gripper operation, and method for manufacturing and using the same.

Abstract

The intervention tool includes a delivery catheter that defines a central lumen and a plurality of peripheral lumens, wherein at least one of the plurality of peripheral lumens defines a spiral path along a portion of the delivery catheter, and at least one wire disposed inside at least one of the plurality of peripheral lumens, configured to activate a medical device.

Description

Technical Field

[0005] , ,

[0001] Cross - reference to Related Applications This application claims the priority of U.S. Provisional Application No. 63 / 484,771, filed on February 14, 2023, which is hereby incorporated by reference in its entirety as if fully set forth herein.

Background Art

[0002] Mitral regurgitation is characterized by a backward flow from the left ventricle of the heart through a damaged mitral valve into the left atrium. During the normal cycle of heart contraction (systole), the mitral valve ideally functions as a one - way valve to prevent oxygenated blood from flowing back into the left atrium. In this way, oxygenated blood is sent through the aortic valve into the aorta. Valve regurgitation can significantly reduce the efficiency of the heart's pumping operation and expose the patient to the risk of severe progressive heart failure.

[0003] Mitral regurgitation can result from various structural defects in the mitral valve or the left ventricular wall. The valve leaflets, chordae tendineae connecting the leaflets to the papillary muscles, papillary muscles, or the left ventricular wall can be damaged or otherwise dysfunctional. Generally, the valve annulus can be damaged, dilated, or weakened, limiting the ability of the mitral valve to close properly against the high pressure in the left ventricle.

[0004] Common treatments for mitral regurgitation rely on valve replacement or repair procedures, including procedures to form the valve leaflets or annulus, the latter generally being called annuloplasty. Another technique for mitral valve repair that depends on suturing adjacent segments of opposing valve leaflets together is called the "bow - tie" method or "edge - to - edge" method. All of these techniques are very effective, but typically rely on open - heart surgery, which usually involves opening the patient's chest, typically by a sternotomy, and placing the patient on cardiopulmonary bypass. The need for both opening the chest and placing the patient on bypass is invasive and is associated with high mortality and morbidity.

[0005] Alternatively, mitral regurgitation may be corrected by catheter-based delivery of an implant that facilitates complete closure of the mitral valve during each cardiac contraction cycle. Catheter-based delivery can be a complex process requiring meticulous attention, numerous inputs, and maneuvers from the implantist, interventionist, or internist, collectively referred to hereafter as “physician.” In some cases, the orientation of the delivery catheter may affect its ability to maneuver the mitral valve repair implant. Specifically, the shape of the delivery catheter during implantation may affect how the repair implant is actuated. This is particularly true for repair implants that rely on gripper manipulation. [Overview of the Initiative]

[0006] In some cases, the intervention tool includes a delivery catheter that defines a central lumen and a plurality of peripheral lumens, wherein at least one of the plurality of peripheral lumens defines a spiral path along a portion of the delivery catheter, and at least one wire disposed inside at least one of the plurality of peripheral lumens, configured to activate a medical device.

[0007] In some examples, a method for activating a medical device includes providing an intervention tool comprising a delivery catheter that defines a central lumen and a plurality of peripheral lumens, wherein at least one of the plurality of peripheral lumens defines a spiral path along a portion of the delivery catheter, and at least one wire disposed inside at least one of the plurality of peripheral lumens, and activating the medical device by pulling the at least one wire. [Brief explanation of the drawing]

[0008] [Figure 1] This figure shows the left ventricle and left atrium of the heart during systole. [Figure 2A] This diagram shows the free edge of the valve leaflet in a normal junction. [Figure 2B] This figure shows the free edge in a joint with backflow. [Figure 3A-3C] These figures show, respectively, the gripping of the valve leaflet by the fixing device, the inversion of the distal element of the fixing device, and the removal of the fixing device. [Figure 4] This figure shows the position of the fixing device in the desired orientation relative to the valve leaflets. [Figure 5] This figure shows an embodiment of a fixing device at a certain position. [Figure 6A-6B] This figure shows an embodiment of the fixing device at a different location. [Figure 7] This figure shows another embodiment of the fixing device at a different location. [Figures 8A-8B] This figure shows an embodiment of a fastening device in which some or all of the components are molded as a single part. [Figure 9] This figure shows another embodiment of the fixing device of the present disclosure. [Figure 10A-10B] This figure shows embodiments of fixation devices in various possible positions during the introduction and placement of devices inside the body for performing therapeutic procedures. [Figure 11A-11B] This figure shows embodiments of fixation devices in various possible positions during the introduction and placement of devices inside the body for performing therapeutic procedures. [Figures 12A-12B] This figure shows embodiments of fixation devices in various possible positions during the introduction and placement of devices inside the body for performing therapeutic procedures. [Figures 13A-13B] This figure shows embodiments of fixation devices in various possible positions during the introduction and placement of devices inside the body for performing therapeutic procedures. [Figure 14] This figure shows embodiments of fixation devices in various possible positions during the introduction and placement of devices inside the body for performing therapeutic procedures. [Figure 15] This figure shows embodiments of fixation devices in various possible positions during the introduction and placement of devices inside the body for performing therapeutic procedures. [Figure 16]This figure shows embodiments of fixation devices in various possible positions during the introduction and placement of devices inside the body for performing therapeutic procedures. [Figure 17A-17C] This diagram shows the covering on the fixing device when the fixing device is in various positions. [Figure 18] This figure shows a delivery catheter attached to a fixation device. [Figures 19A-19B] This is a schematic diagram of the multi-lumen extrusion section of the delivery catheter, and an axial cross-sectional view of the multi-lumen extrusion section of the delivery catheter. [Figure 20] This figure shows a multi-lumen extrusion section arranged along the entire delivery catheter according to the first embodiment. [Figure 21] This figure shows a multi-lumen extrusion section arranged along only a portion of the delivery catheter according to the second embodiment. [Modes for carrying out the invention]

[0009] When used in relation to delivery devices for transporting the device to a patient, the terms “proximal” and “distal” are considered relative to the user of the delivery device. “Proximal” should be understood as being relatively close to the user, and “distal” as being relatively far from the user. When used in relation to fixation devices, the terms “proximal” and “distal” are considered relative to the treatment site. “Proximal” should be understood as being relatively close to the treatment site, and “distal” as being relatively far from the treatment site. When used herein, the terms “substantially,” “generally,” “approximately,” and “about” are intended to mean that a slight deviation from the absolute falls within the range of the thus modified term. Throughout the disclosure, the mitral valve is described in an exemplary manner. Clips can similarly be used to treat the tricuspid valve to reduce right-side regurgitation of the heart. This tricuspid valve repair approach is particularly hampered by poor imaging due to the unfavorable anatomical structure of the heart relative to the esophagus. Transesophageal echocardiography probes can be favorably pushed toward the left side of the heart to obtain appropriate imaging of the mitral valve. This is not the case for the tricuspid valve, and imaging is generally inferior. For this reason, the sensor may offer a special advantage in giving the user confidence in implanting clips in tricuspid valve repair procedures. Thus, this disclosure is not limited to mitral valve clips, and similar techniques may be used to ensure proper placement of other clips, valves or other devices in cardiac and other medical applications.

[0010] I. Cardiac Physiology The normal left ventricle LV of the heart H during systole is illustrated in FIG. 1. The left ventricle LV is contracting, and blood flows outward through the aortic valve AV in the direction of the arrow. Since the mitral valve is configured as a "check valve" that prevents backflow when the pressure in the left ventricle is higher than the pressure in the left atrium LA, backflow of blood through the mitral valve MV, that is, "regurgitation", is prevented. The mitral valve MV includes a pair of valve leaflets having free edges FE that close evenly together as illustrated in FIG. 1. Both ends of the valve leaflets LF are attached to the surrounding heart structures along an annular region called the annulus AN. The free edge FE of the valve leaflets LF is fixed to the lower part of the left ventricle LV through chordae tendineae CT (hereinafter referred to as chordae), which include a plurality of branched chords fixed across the lower surface of each of the valve leaflets LF. The chordae CT are themselves attached to papillary muscles PM that extend upward from the lower part of the left ventricle and the interventricular septum IVS.

[0011] Multiple structural defects within the heart can cause mitral valve regurgitation. Regurgitation occurs when the valve leaflets do not close properly, allowing leakage from the ventricle to the atrium. As shown in FIG. 2A, the free edges of the anterior and posterior leaflets normally meet along a line of junction C. An example of a defect causing regurgitation is shown in FIG. 2B. Here, due to the enlargement of the heart, the mitral valve annulus becomes enlarged, and the free edge FE cannot meet during systole. This results in a gap G through which blood can leak through the valve during ventricular contraction. Ruptured or elongated chordae can similarly cause prolapse of the valve leaflets because inappropriate tension is transmitted to the leaflets through the chordae. While the other valve leaflets maintain a normal shape, the two valve leaflets do not meet properly, and leakage from the left ventricle to the left atrium will occur. Such regurgitation can also occur in patients suffering from ischemic heart disease in which the left ventricle does not contract to an extent sufficient to provide proper closure.

[0012] II. General Overview The present disclosure provides methods and devices for grasping, approximating, and fixing tissue such as valve leaflets to treat cardiac valve regurgitation, particularly mitral valve regurgitation. The present disclosure also provides features that enable repositioning and removal of the device, if desired, particularly in areas where removal may be impeded by anatomical features such as chordae tendineae CT. Such removal would enable the surgeon to approach the valve again in a new configuration, if desired.

[0013] Grasping is preferably atraumatic and provides a number of advantages. By atraumatic is meant that the devices and methods of the present disclosure can be applied to and later removed from the valve leaflets without causing any significant clinical impairment to the structure or function of the valve leaflets. The valve leaflets and valves continue to function substantially the same as they did prior to the application of the present disclosure. Thus, even if some minor indentation or depression of the valve leaflets occurs using the present disclosure, it may still meet the definition of "atraumatic." For this reason, the devices of the present disclosure are applicable to diseased valves and can be removed or repositioned, if desired, without adversely affecting the function of the valve. Additionally, it is understood that in some cases it may be necessary or desirable to create a hole or otherwise permanently affect the valve leaflets, either during or between grasping and fixing, or both. In some cases, grasping and fixing can be accomplished by a single device. While multiple embodiments are provided to achieve these results, a general overview of the basic features is presented herein. Such features are not intended to limit the scope of the present disclosure and are presented for the purpose of providing a basis for the description of the individual embodiments described later in this application.

[0014] The apparatus and methods of this disclosure rely on the use of an intervention tool that is positioned near the desired treatment site and used to grasp the target tissue. In intravascular applications, the intervention tool is typically an intervention catheter. In surgical applications, the intervention tool is typically an intervention instrument. In preferred embodiments, fixation of the grasped tissue is achieved by maintaining the grasp with a portion of the intervention tool that remains as an implant. Although this disclosure has a variety of applications for tissue proximity and fixation throughout the body, it is particularly well adapted for the repair of valves, especially heart valves, such as the mitral valve. Referring to Figure 3A, an intervention tool 10 having a delivery device such as a shaft 12 and a fixation device 14 is illustrated approaching the mitral valve MV from the atrial side and grasping the valve leaflet LF. As described above, the mitral valve is accessible using surgical or endovascular techniques and by either a retrograde approach through the ventricle or an antegrade approach through the atrium. For illustrative purposes, the antegrade approach will be described.

[0015] The fixation device 14 is releasably attached to the shaft 12 of the intervention tool 10 at its distal end. When describing the devices of this disclosure in this specification, “proximal” refers to the direction toward the end of the device to be manipulated by the user outside the patient’s body, and “distal” refers to the direction toward the working end of the device to be positioned at the treatment site, away from the user. With respect to the mitral valve, “proximal” refers to the atrial side, i.e., upstream side, of the valve leaflet, and “distal” refers to the ventricular side, i.e., downstream side, of the valve leaflet.

[0016] The fixation device 14 typically includes a proximal element 16 (or gripping element) and a distal element 18 (or fixing element), which project radially outward and can be positioned on either side of the valve leaflet LF as shown for the purpose of capturing or holding the valve leaflet between them. The proximal element 16 is preferably made of cobalt-chromium, nitinol, or stainless steel, and the distal element 18 is preferably made of cobalt-chromium or stainless steel, but any suitable material can be used. The fixation device 14 can be coupled to the shaft 12 by a coupling mechanism 17. The coupling mechanism 17 allows the fixation device 14 to be detached and left as an implant to hold the valve leaflet together in the joint position.

[0017] Depending on the situation, it may be desirable to reposition or remove the fixation device 14 after the proximal element 16, the distal element 18, or both have been deployed to capture the valve leaflet LF. Such repositioning or removal may be desired for a variety of reasons, including, to reposition the device closer to the valve in an attempt to achieve better valve function, for a more optimal positioning of the device 14 on the valve leaflet, for a better foothold on the valve leaflet, to detach the device 14 from surrounding tissues such as chordae tendineae, to replace the device 14 with a device of a different design, or to interrupt the fixation procedure. To facilitate the repositioning or removal of the fixation device 14, the distal element 18 is releasable and can be optionally reversed into a configuration suitable for withdrawing the device 14 from the valve without entanglement, interference, or damage to chordae tendineae, valve leaflets, or other tissues. Figure 3B illustrates reversal in which the distal element 18 is movable in the direction of arrow 40 to the reversal position. Similarly, the proximal element 16 can be raised (upright) if desired. In the inverted position, the device 14 may be repositioned to a desired orientation, where the distal element may be returned to a gripping position relative to the valve leaflet, as shown in Figure 3A. Alternatively, the fixation device 14 may be withdrawn from the valve leaflet, as shown in Figure 3C (indicated by arrow 42). Such inversion reduces trauma to the valve leaflet and minimizes any entanglement of the device with surrounding tissues. Once the device 14 is withdrawn through the valve leaflet, the proximal and distal elements can be moved to a closed position or configuration suitable for removal from the body or reinsertion through the mitral valve.

[0018] Figure 4 illustrates the position of the fixation device 14 in a desired orientation in relation to the valve leaflet LF. Since this is a short-axis view of the mitral valve MV from the atrial side, the proximal element 16 is shown by a solid line and the distal element 18 is shown by a dashed line. The proximal element 16 and distal element 18 are positioned substantially perpendicular to the line of joint C. The device 14 can move approximately along the joint line to the location of regurgitation. During cardiac diastole, the valve leaflet LF is held in place so that it remains in a fixed position between elements 16 and 18, surrounded by the opening O resulting from the diastolic pressure gradient, as shown in Figure 4. Advantageously, the valve leaflet LF is joined so that its proximal, i.e., upstream surface faces each other in a vertical orientation, parallel to the direction of blood flow through the mitral valve MV. The upstream surfaces may be joined in contact with each other or held slightly apart, but preferably, the upstream surfaces are maintained in a vertical orientation facing each other at the joint point. This simulates the double orifice geometry of a standard surgical bowtie repair. Color Doppler echocardiography indicates whether valve regurgitation has been reduced. If the resulting mitral flow pattern is satisfactory, the leaflets can be fixed together in this orientation. If the resulting color Doppler image indicates insufficient improvement of mitral regurgitation, the intervention tool 10 may be repositioned. This can be repeated until the optimal result is obtained in which the leaflets LF are held in place.

[0019] Once the valve leaflets are joined in the desired position, the fixation device 14 is then detached from the shaft 12 and remains as an implant, holding the valve leaflets together in the joined position. As described above, the fixation device 14 is coupled to the shaft 12 by a coupling mechanism 17. Other coupling mechanisms are described in U.S. Patent No. 9,510,829 and are incorporated by reference as fully described herein.

[0020] III.Fixation device A. Introduction and placement of fixed devices The fixation device 14 is delivered to the valve or desired tissue using a delivery device. The delivery device may be rigid or flexible depending on the application. For intravascular applications, the delivery device includes a flexible delivery catheter, which will be described in a later section. Typically, however, such a catheter includes a shaft having a proximal and distal end, and a fixation device releasably attached to the distal end. The shaft is usually slender and flexible, which is suitable for intravascular introduction. Alternatively, the delivery device may include a shorter, less flexible interventional device that can be used for transthoracic introduction through the wall of the heart, but generally, some degree of flexibility and a minimal external shape are desirable. The fixation device can be releasably coupled to the delivery device, as shown in Figure 3A. The fixation device may have various forms, several embodiments thereof are described herein.

[0021] Figures 5, 6A–6B, and 7 illustrate embodiments of the fixation device 14 in various positions or configurations. Figure 5 illustrates the fixation device 14 in a closed configuration for delivery through the patient's vascular system, and in this example, through the mitral valve. The fixation device 14 includes a coupling member 19 that allows the fixation device 14 to be detached for implantation. In this example, the coupling member 19 is shown to include a lower shaft 22 and a mating surface 24, and thus the coupling member 19 will function as described above. The fixation device 14 also includes a pair of opposing distal elements 18, each distal element 18 having an engaging surface 50 facing inward toward the opposing distal element 18 in the closed configuration. The distal elements 18 preferably include elongated arms 53, each arm having a proximal end 52 and a free end 54 rotatably connected to the coupling member 19. Preferred connections of the arms 53 to the coupling member 19 include pins, living hinges, or other known rotational connection mechanisms. In the closed configuration of Figure 5, the free end 54 is oriented in a first direction, and the arms 53 and engagement surface 50 are substantially parallel to each other and to the axis 21, preferably angled slightly inward toward each other. In a preferred embodiment, if no tissue is present between the arms 53, the arms 53 may be closed until the free ends 54 contact each other or engage with the shaft 12 when the fastener 14 is attached, thereby minimizing the external shape of the fastener 14 for passage through the delivery device.

[0022] Figures 6A and 6B illustrate the fixing device 14 in the open position, where the engaging surfaces 50 are separated by a separation angle 56. Here, the separation angle 56 is typically up to about 180 degrees, preferably 90 to 180 degrees, and the arm 53 is positioned generally symmetrically with respect to the axis 21. The arm 53 may be movable to the open position by various actuation mechanisms. For example, a plunger or actuation rod may be advanced through the coupling member 19, as indicated by arrow 62, to engage with a spring attached to the distal element 18, or a spring-loaded actuation mechanism 58. By applying force to the actuation mechanism 58, the distal element 18 is rotated relative to the coupling member 19. When the distal element 18 is separated by an angle less than 180 degrees, the distal element 18 may be held in this open position by the actuation rod against the resistance force provided by the spring of the actuation mechanism 58 that biases the distal element 18 toward the closed position shown in Figure 5. The spring load of the actuation mechanism 58 resists the outward movement of the actuation mechanism 58 and biases the device 14 toward the closed position.

[0023] In this embodiment, the proximal element 16 includes an elastic loop-shaped wire form attached to the coupling member 19, biased outward so as to be rotatable inward when the arm 53 is closed, although it is biased to the open position shown in Figure 6B. The wire form may be rigidly attached to the coupling member 19 and have sufficient flexibility to be elastically deflected inward, or the wire form may be attached by a rotational coupling such as a pin or living hinge. When in use, the valve leaflet LF is positioned between the proximal element 16 and the distal element 18. When the valve leaflet LF is positioned between the proximal element 16 and the distal element 18, the distal element 18 closes, and the valve leaflet between the engagement surface 50 and the proximal element 18 can be compressed. Depending on the leaflet thickness, leaflet arrangement, the position of the fixation device on the leaflet, and other factors, the arm 53 may be maintained in the open position shown in Figures 6A-6B, moved to the fully closed position shown in Figure 5, or positioned in any of the various positions in between, in order to join the leaflet LF and hold the leaflet in the desired position with the desired degree of force. In any case, the fixation device 14 remains in place as an implant even after detachment from the delivery catheter.

[0024] Depending on the circumstances, it may be desirable to reopen the fixing device 14 after the initial positioning, as described above. To reopen the device 14, the operating rod may be advanced or reinserted through the coupling member 19 and advanced again so as to press against the operating mechanism 58, as previously shown by arrow 62 in Figure 6A. Again, such advancement applies force to the operating mechanism 58 as described above, moving the arm 53 outward to release the force on the valve leaflet and moving the engagement surface 50 away from the proximal element 16. This allows the valve leaflet to move freely relative to the fixing device 14. The fixing device 14 is then repositioned as desired, and the operating rod may be bent to reopen the distal element 18 to engage the valve leaflet.

[0025] In some situations, it may be even more desirable to pull the fixation element 14 back through the valve, or to completely withdraw the fixation device from the patient after the initial insertion through the valve. If this is attempted with the clip in the closed or open position as shown in Figures 5, 6A-6B and 7, there is a risk that the arm 53 may interfere with or become entangled with the chordae tendineae, valve leaflets, or other tissues. To avoid this, it is preferable that the fixation element 14 be adapted to the reversal of the arm 53 such that the free end 54 faces in a second direction opposite to a first direction toward the closed position, and each arm 53 forms an obtuse angle with respect to the axis 21 as shown in Figure 7. The arm 53 may be rotated so that the engagement surface 50 is positioned at a separation angle 56 of up to 360 degrees, preferably at least 270 degrees. This can be achieved by applying force to the actuation mechanism 58 with a push rod or plunger extending through the coupling member 19, as described above. In this embodiment, when the distal element 18 rotates more than 180 degrees, the spring load of the actuation mechanism 58 biases the distal element 18 toward the reversed position. The spring load of the actuation mechanism 58 resists the outward movement of the actuation mechanism 58 and biases the device 14 toward the reversed position.

[0026] When arm 53 is in the reversed position, the engagement surface 50 becomes a non-traumatic surface that deflects tissue when the fixation device is withdrawn. This allows the device to be withdrawn through the valve annulus without the risk of damaging the heart valve and other tissues. In some cases, once the fixation device 14 has been withdrawn through the valve, it is desirable to return the device to the closed position (either through the vascular system or a surgical opening) to withdraw the device from the body.

[0027] Embodiments illustrated in Figures 5, 6A–6B, and 7 are assembled from multiple separate components made of biocompatible materials. These components may be formed from the same or different materials, but are not limited to, stainless steel or other metals, Elgiloy®, Nitinol, titanium, tantalum, metal alloys, or polymers. In addition, some or all of these components may be made from bioabsorbable materials that are absorbed by the surrounding tissue or dissolved in the bloodstream after implantation. In mitral valve repair applications, it has been found that the fixation devices of this disclosure may be completely surrounded by tissue within a few months after implantation, and subsequently dissolve or be absorbed without adversely affecting the repair.

[0028] In further embodiments, some or all of the components may be molded as a single piece, as shown in Figures 8A and 8B. Here, the coupling member 19, distal element 18, and actuation mechanism 58 of the fixing device 14 are all molded as a single movable piece from a polymer material. Figure 8A shows the fixing device 14 in the open position. The forward movement of the actuation rod 64 rotates the distal element 18 relative to the coupling member 19 by a living hinge or by the elastic deformation of the plastic at the connection point between the element 18 and the coupling member 19. Typically, this connection point consists of a thinner segment of the polymer to facilitate such bending. Similarly, the actuation mechanism 58 is coupled to the distal element 18 in the same way. Figure 8B shows the fixing device 14 in the reversed position.

[0029] Figure 9 illustrates another embodiment of the fixation device 14, where it is shown coupled to the shaft 12 to form an intervention tool 10. The fixation device 14 includes a coupling member 19 and a pair of opposing distal elements 18. The distal elements 18 include elongated arms 53, each having a proximal end 52 and a free end 54 rotatably connected to the coupling member 19. The free ends 54 have a rounded shape to minimize interference with and trauma to surrounding tissue structures. Preferably, each free end 54 defines a curvature around two axes, one of which is an axis 66 perpendicular to the longitudinal axis of the arm 53. Thus, the engagement surface 50 has a cup-shaped or concave shape with respect to the surface area in contact with the tissue to assist in gripping and holding the valve leaflets. This further allows the arms 53 to be nested around the shaft 12 in the closed position to minimize the external shape of the device. Preferably, the arm 53 is at least partially cupped or curved inward around the longitudinal axis 66. Also preferably, each free end 54 defines a curvature around the axis 66 or an axis 67 perpendicular to the longitudinal axis of the arm 53. This curvature is a reverse curvature along the most distal portion of the free end 54. Similarly, the longitudinal edge of the free end 54 may flare outward. Both the reverse curvature and flaring minimize trauma to the tissue engaged with the free end.

[0030] In a preferred embodiment suitable for mitral valve repair, the transverse width across the engagement surface 50 (the width that determines the width of the engaged tissue) is at least about 2 mm, typically 3 to 10 mm, and preferably about 4 to 6 mm. In some situations, a wider engagement is desired, in which case the engagement surface 50 is larger, for example, about 2 cm, or multiple fixation devices are used adjacent to each other. The arm 53 and the engagement surface 50 are configured to engage with a tissue length of about 4 to 10 mm, preferably about 6 to 8 mm, along the longitudinal axis of the arm 53. The arm 53 further includes multiple openings to enhance grip and promote post-graft tissue grafting.

[0031] The valve leaflets are held between the distal element 18 and the proximal element 16. In some embodiments, the proximal element 16 is flexible, elastic, and extends cantilevered from the connecting member 19. The proximal element is preferably elastically biased toward the distal element. Each proximal element 16 is shaped and positioned to at least partially recess into the concave surface of the distal element 18 when no tissue is present. When the fixing device 14 is in the open position, the proximal elements 16 are shaped such that each proximal element 16 is separated from the engagement surface 50 near the proximal end 52 of the arm 53, as illustrated in Figure 9, and each proximal element has a slope toward the engagement surface 50 near the free end 54, with the free end of the proximal element in contact with the engagement surface 50. This shape of the proximal element 16 accommodates valve leaflets or other tissue of variable thickness.

[0032] The proximal element 16 includes a plurality of openings 63 and wavy side edges 61 to enhance grip on tissue. The proximal element 16 optionally includes friction attachments, friction features, or grip-enhancing elements to assist in gripping and / or retaining the valve leaflets. In a preferred embodiment, the friction attachment includes a barb 60 having a tapered, sharp tip extending toward the engagement surface 50. It will be recognized that any suitable friction attachment can be used, such as prongs, windings, bands, barbs, grooves, channels, bumps, surface roughening, sintering, high-friction pads, coatings, or combinations thereof.

[0033] Optionally, magnets may be present in the proximal and / or distal elements. It will be recognized that the occlusal surfaces are made of or contain materials with opposite magnetic poles to generate magnetic attraction. For example, the proximal and distal elements may each contain magnetic material with opposite poles so that tissue is held under constant compression between the proximal and distal elements to facilitate faster tissue healing and endografting. Alternatively, in addition to or instead of biasing the proximal element toward the distal element, magnetic force may be used to attract the proximal element 16 toward the distal element 18. This can assist in the deployment of the proximal element 16. In another example, each distal element 18 contains magnetic material with opposite poles so that tissue positioned between the distal elements 18 is held between them by magnetic force.

[0034] The proximal element 16 may be covered with a fabric or other flexible material to enhance post-graft grip and tissue endografting, as described below. Preferably, if the fabric or covering is used in combination with a fascia or other friction feature, such feature protrudes from the fabric or covering and comes into contact with another tissue with which the proximal element 16 engages.

[0035] In exemplary embodiments, the proximal element 16 is formed from a metal sheet of spring-like material using a stamping process to create an opening 63, a wavy edge 61, and a barb 60. Alternatively, the proximal element 16 may be composed of spring-like material or molded from a biocompatible polymer. While some types of friction attachments available in this disclosure may permanently alter the tissue they engage or cause some degree of trauma to that tissue, in preferred embodiments, the friction attachments are non-traumatic and do not cause clinically significant damage or other effects to the tissue. For example, in the case of the barb 60, it has been demonstrated that the barb 60 is considered non-traumatic because, after engagement of the mitral valve leaflet by the fixation device 14, the device is removed during subsequent procedures, leaving no significant permanent scarring or other damage to the valve leaflet tissue.

[0036] The fixing device 14 also includes an operating mechanism 58. In this embodiment, the operating mechanism 58 includes two link members or legs 68, each leg 68 having a first end 70 rotatably connected to one of the distal elements 18 by a rivet joint 76 and a second end 72 rotatably connected by a stud 74. The legs 68 are preferably made of a rigid or semi-rigid metal or polymer, such as Elgiloy®, cobalt-chromium or stainless steel, but any suitable material may be used. In this embodiment, both legs 68 are pinned to the stud 74 by a single rivet 78, but it can be recognized that each leg 68 may be individually attached to the stud 74 by separate rivets or pins. The stud 74 is connectable to an actuation rod 64 (not shown), which extends through a shaft 12 and is axially extendable and retractable to move the stud 74 and, consequently, the leg 68 that rotates the distal element 18 between closed, open, and reversed positions. Similarly, by immobilizing the stud 74, the leg 68 is held in place and thus the distal element 18 is held in the desired position. The stud 74 may also be locked in place by locking features, which are further described in the following sections.

[0037] In any embodiment of the fixation device 14 disclosed herein, it may be desirable to impart some mobility or flexibility to the distal element 18 and / or proximal element 16 in the closed position so that they can move or bend with the opening and closing of the valve leaflets. This provides shock absorption, thereby reducing forces on the valve leaflets and minimizing the possibility of tearing or other trauma to the valve leaflets. Such mobility or flexibility may be imparted by using a flexible and elastic metal or polymer of appropriate thickness to construct the distal element 18. Furthermore, the locking mechanism of the fixation device (described below) may be constructed of a flexible material to allow a certain slight movement of the proximal and distal elements even when locked. In addition, the distal element 18 can be connected to a coupling mechanism 19 or an actuation mechanism 58 by a mechanism that biases the distal element (inward) to the closed position but allows the arm to open slightly in response to forces applied by the valve leaflets. For example, rather than being pinned at a single point, these components can be pinned through slots that allow for slight translation of the pin in response to a force opposing the arm. A spring is used to bias the pinned components toward one end of the slot.

[0038] Figures 10A–10B, 11A–11B, 12A–12B, 13A–13B, and 14–16 illustrate embodiments of the fixation device 14 of Figure 9 in various possible positions during the introduction and placement of the device 14 inside the body for performing a therapeutic procedure. Figure 10A illustrates one embodiment of the intervention tool 10 delivered through a catheter 86. It will be recognized that the intervention tool 10 may take the form of a catheter, and similarly, the catheter 86 may take the form of a guide catheter or a sheath. However, in this example, the terms intervention tool 10 and catheter 86 are used. The intervention tool 10 includes a fixation device 14 coupled to a shaft 12, the fixation device 14 is shown in the closed position. Figure 10B illustrates a similar embodiment of the fixation device of Figure 10A in a larger view. In the closed position, opposing pairs of distal elements 18 are positioned so that their engaging surfaces 50 face each other. Each distal element 18 includes elongated arms 53 having a cup-shaped or concave shape so that the arms 53 together surround the shaft 12 and optionally contact each other on both sides of the shaft. Thus, a small form of the fixation device 14 is provided that can be easily passed through the catheter 86 and through any anatomical structure such as the mitral valve. In addition, Figure 10B further includes an actuation mechanism 58. In this embodiment, the actuation mechanism 58 includes two legs 68, each movably coupled to a base 69. The base 69 is connected to an actuation rod 64 that extends through the shaft 12 and is used to steer the fixation device 14. In some embodiments, the actuation rod 64 is directly attached to the actuation mechanism 58, in particular to the base 69. However, the actuation rod 64 may alternatively be attached to a stud 74 which itself is attached to the base 69. In some embodiments, the stud 74 is threaded so that the actuation rod 64 is attached to the stud 74 by a screw-type action. However, the rod 64 and the stud 74 may be connected by any mechanism that can be released so that the fixing device 14 can be detached from the shaft 12.

[0039] Figures 11A and 11B illustrate the fixing device 14 in the open position. In the open position, the distal element 18 is rotated so that the engaging surface 50 faces the first direction. The distal advance of the stud 74 relative to the coupling member 19 by the action of the actuating rod 64 applies force to the distal element 18, and since the distal element is free to move in this direction, it begins to rotate around the joint 76. Such rotation and movement of the distal element 18 radially outward causes the leg 68 to rotate around the joint 80, thereby orienting the leg 68 directly slightly outward. The stud 74 may be advanced to any desired distance correlated with the desired separation of the distal element 18. In the open position, the engaging surface 50 is positioned at an acute angle with respect to the shaft 12, preferably at an angle between 90 and 180 degrees with respect to each other. In one embodiment, in the open position, the free end 54 of the arm 53 has a span of approximately 10 to 20 mm, usually about 12 to 18 mm, preferably about 14 to 16 mm, between its two ends.

[0040] The proximal element 16 is typically biased outward toward the arm 53. The proximal element 16 is moved inward toward the shaft 12, and the proximal element may be held in contact with the shaft 12 using a proximal element wire 90, which can be in the form of sutures, wires, nitinol wires, rods, cables, polymer wires, or other preferred structures. The proximal element wire 90 may be connected to the proximal element 16 by sewing the wire 90 through in various ways. If the proximal element 16 has a loop shape, as shown in Figure 11A, the wire 90 can pass through the loop and fold back. If the proximal element 16 has an elongated solid shape, as shown in Figure 11B, the wire 90 can pass through one or more of the openings 63 of the element 16. Furthermore, a wire loop 48, also shown in Figure 11B, may be present on the proximal element 16, and the proximal element wire 90 may pass through the loop and fold back. Such wire loops 48 may be useful for reducing friction on the proximal element wire 90, or when the proximal element 16 is solid or does not have other loops or openings through which the proximal element wire 90 can be attached. The proximal element wire 90 can be attached to the proximal element 16 by a detachable means that allows a single wire 90 to be attached to the proximal element 16 without folding, and, if desired, allows the single wire 90 to be detached directly from the proximal element 16. Examples of such detachable means include hooks, snares, clips, or breakable joints. By applying sufficient tension to the proximal element wire 90, the detachable means can be detached from the proximal element 16, for example, by breaking the joint. Other mechanisms for detachment may also be used. Similarly, the locking wire 92 can be attached to and detached from the locking mechanism by similar detachable means.

[0041] In the open position, the fixation device 14 can engage with the tissue to be located nearby or treated. Embodiments shown in Figures 9 to 11 are adapted for mitral valve repair using an antegrade approach from the left atrium. The intervention tool 10 is advanced through the mitral valve from the left atrium to the left ventricle. The distal element 18 is oriented perpendicular to the junction line and then positioned so that the engaging surface 50 contacts the ventricular surface of the valve leaflet to grasp it. The proximal element 16 remains on the atrial side of the leaflet so that the leaflet is located between the proximal and distal elements. In this embodiment, the proximal element 16 has a friction attachment such as a barb 60 directed toward the distal element 18. However, neither the proximal element 16 nor the barb 60 contacts the valve leaflet at this point.

[0042] The intervention tool 10 may be repeatedly steered to reposition the fixation device 14 so that the valve leaflets are properly contacted or grasped at the desired location. Repositioning is achieved with the fixation device in the open position. In some cases, backflow can also be checked with the device 14 in the open position. If backflow is not sufficiently reduced, the device may be repositioned and backflow checked again until the desired result is achieved.

[0043] To assist in repositioning or removing the fixing device 14, it may be desirable to invert the fixing device 14. Figures 12A and 12B illustrate the fixing device 14 in the inverted position. By advancing the stud 74 further relative to the coupling member 19, the distal element 18 is further rotated such that the engaging surface 50 faces outward and the free end 54 faces distally, with each arm 53 forming an obtuse angle with respect to the shaft 12. The angle between the arms 53 is preferably in the range of about 270 to 360 degrees. Further advancing the stud 74 causes the distal element 18 to rotate further around the joint 76. This rotation and movement of the radially outward-facing distal element 18 results in the rotation of the legs 68 around the joint 80 so that the legs 68 are returned to their initial positions where they are generally parallel to each other. The stud 74 may be advanced to any desired distance corresponding to the desired inversion of the distal element 18. Preferably, in the fully inverted position, the span between the free ends 54 is about 20 mm or less, usually less than about 16 mm, preferably about 12 to 14 mm. In this example, the proximal element 16 remains positioned in contact with the shaft 12 by applying tension to the proximal element wire 90. Thus, a relatively large space for repositioning can be created between elements 16 and 18. In addition, the inverted position allows for withdrawal of the fixation device 14 through the valve while minimizing trauma to the valve leaflets. The engagement surface 50 provides a non-traumatic surface for deflecting tissue as the fixation device is retracted proximal. It should also be noted that the barb 60 is angled slightly distally (away from the free end of the proximal element 16) to reduce the risk of the barb catching or tearing tissue while the fixation device is being withdrawn.

[0044] Once the fixing device 14 is in contact with the valve leaflet and positioned in the desired location, the valve leaflet may then be captured between the proximal element 16 and the distal element 18. Figures 13A and 13B illustrate the fixing device 14 in such a position. Here, the proximal element 16 is lowered toward the engagement surface 50 so that the valve leaflet is held between the proximal elements. In Figure 13B, it is shown that the proximal element 16 includes a barb 60 which can be used to perform a non-traumatic grip of the valve leaflet. Alternatively, a larger, sharper barb or other penetrating structure can be used to more actively assist in perforating and holding the valve leaflet in place. This position is similar to the open position in Figures 11A and 11B, except that the proximal element 16 is lowered toward the arm 53 by releasing tension on the proximal element wire 90 to compress the valve leaflet tissue between them. If the backflow is not sufficiently reduced, the proximal element 16 can be raised and the distal element 18 adjusted or reversed at any time to reposition the fixing device 14.

[0045] After the valve leaflet is captured between the proximal element 16 and the distal element 18 in the desired position, the distal element 18 may be locked to hold the valve leaflet in this position, or the locking device 14 may be returned to or toward the closed position. Such locking will be described in a later section. Figure 14 illustrates the locking device 14 in the closed position with the valve leaflet (not shown) captured and joined. This is achieved by retracting the stud 74 proximal to the coupling member 19, the leg 68 of the actuation mechanism 58 applies an upward force to the distal element 18, and then rotates the distal element 18 so that the engaging surfaces 50 face each other again. The released proximal element 16, biased outward toward the distal element 18, is simultaneously biased inward by the distal element 18. The locking device 14 may then be locked to hold the valve leaflet in this closed position, as will be described below.

[0046] As shown in Figure 15, the fixation device 14 may then be released from the shaft 12. As described above, the fixation device 14 is releasably coupled to the shaft 12 by the coupling member 19. Figure 15 illustrates the coupling structure, which is a portion of the shaft 12 to which the coupling member 19 of the fixation device 14 is attached. As shown, the proximal element wire 90 can remain attached to the proximal element 16 after detachment from the shaft 12 and function as a tether to keep the fixation device 14 connected to the catheter 86. Optionally, another tether coupled between the shaft 12 and the fixation device 14 may be used for this purpose while the proximal element wire 90 is removed. In either case, repair of the valve leaflet or tissue can be observed by non-invasive visualization techniques such as echocardiography to ensure the desired outcome. If repair is not desired, the fixation device 14 can be retrieved using the tether or the proximal element wire 90 to reconnect the coupling member 19 to the shaft 12.

[0047] In an exemplary embodiment, the proximal element wire 90 is an elongated, flexible twisted yarn, wire, cable, suture, or bristle extending through the shaft 12, looped through the proximal element 16, and extending back through the shaft 12 to its proximal end. When detachment is desired, one end of each bristle is released at the proximal end of the shaft 12, and the other end is pulled to pull out the free end of the bristle distally through the shaft 12 and through the proximal element 16, thereby releasing the fastening device.

[0048] Figure 16 illustrates the open fixation device 14 in a closed position. As shown, the coupling member 19 remains separated from the shaft 12 of the intervention tool 10, and the proximal element 16 is deployed so that tissue (not shown) may be present between the proximal element 16 and the distal element 18.

[0049] The embodiments described above in this disclosure utilize a push-open, pull-close mechanism for opening and closing the distal element 18, but it should be understood that a pull-open, push-close mechanism is equally possible. For example, the distal element 18 may be coupled to a stud 74 rather than a coupling member 19 at its proximal end, and the leg 68 may be coupled to a coupling member 19 rather than a stud 74 at its proximal end. In this example, it is assumed that the distal element 18 is closed when the stud 74 is pushed distally relative to the coupling member 19, while the distal element 18 is opened when the stud 74 is pulled proximal toward the coupling member 19.

[0050] B. Covering on the fixing device The fixation device 14 may optionally include a covering. The covering can assist in tissue gripping and can later provide a surface for tissue ingrowth. Ingrown surrounding tissue, such as valve leaflets, can provide stability to the device 14 as the device is further fixed in place, covering the device with natural tissue and reducing the possibility of an immune response. The covering may consist of any biocompatible material, such as polyethylene terephthalate, polyester, cotton, polyurethane, stretched polytetrafluoroethylene (ePTFE), silicone, or various polymers or fibers, and may have any preferred form, such as fabric, mesh, textured weave, felt, looped, or porous structure. Generally, the covering has a small profile so as not to interfere with delivery through the introducer sheath or with the gripping and joining of valve leaflets or tissue.

[0051] Figures 17A to 17C illustrate the covering 100 on the fixation device 14 when the device 14 is in various positions. Figure 17A shows the covering 100 enclosing the distal element 18 and the operating mechanism 58 while the device 14 is in the open position. Thus, the engagement surface 50 is covered by the covering 100, which helps minimize trauma to the tissue and provides additional friction to assist in grasping and retaining the tissue. Figure 17B shows the device 14 of Figure 17A in the inverted position. The covering 100 is loosely fitted and / or flexible or elastic so that the device 14 can move freely to various positions, and the covering 100 conforms to the contour of the device 14 and remains securely attached in all positions. Figure 17C shows the device 14 in the closed position. Thus, when the fixation device 14 is left as an implant in the closed position, the exposed surface of the device 14 is substantially covered by the covering 100. It may be recognized that the covering 100 covers certain parts of the fixation device 14 while leaving other parts exposed. For example, the covering 100 may include a sleeve that fits over the distal element 18 rather than the actuation mechanism 58, a cap that fits over the distal end 54 of the distal element 18, or a pad that covers the engagement surface 50. It may be recognized that any friction attachments, such as barbs, may be left exposed. The covering 100 may also cover any other surface of the proximal element 16 and / or the fixation device 14. In any case, the covering 100 should be durable enough to withstand multiple induction cycles and, if implanted inside the heart, the duration of the cardiac cycle.

[0052] The coating 100 may alternatively consist of a polymer or other suitable material that is immersed, sprayed, coated, or otherwise adhered to the surface of the fixation device 14. Optionally, the polymer coating may include pores or contours to assist in tissue gripping and / or promote tissue endoproliferation.

[0053] Each of the coatings 100 may optionally contain, to name a few, drugs, antibiotics, antithrombotic agents, or antiplatelet agents, such as heparin, COUMADIN® (warfarin sodium). These agents may be impregnated into the coating 100 or coated onto the coating. These agents may then be delivered to the grasped tissue and / or surrounding blood flow for therapeutic effect.

[0054] C. Improved gripper operation The above disclosure describes several modifications of the fixation device and the corresponding delivery device for implanting the fixation device within the original anatomical structure. The improved gripper action embodiments described in this section may be understood by referring to Figures 1 to 17C, and any of the features, characteristics, methods, or modifications described above, or combined with other embodiments in this section. Figure 18 illustrates an example of a fixation device 14 coupled to an intervention tool 10, an intervention tool 10 having a shaft 12, a delivery catheter 86 covered with a sleeve 87, and one or more wires 90a, 90b passing through the delivery catheter 86. In some embodiments, it may be desirable to raise and lower the proximal elements 16a, 16b (also called grippers) of the fixation device 14 and to actuate these elements independently near or far from the corresponding arm 53. This may be done by actinguating a gripper lever on a handle (not shown) to maneuver the snare or wires 90a, 90b as described above. Each lever can increase the tension of the corresponding wires 90a, 90b (e.g., by pulling up the lever) or decrease the tension of the wires acting through the length of the delivery catheter 86 (e.g., by pushing down the lever). As shown in the cross-sectional view, the delivery catheter 86 may include a central lumen 91 and small or peripheral lumens 92a, 92b positioned on either side of the extrusion cross section to receive the wires 90a, 90b. In some examples, each of the wires 92a, 92b may extend through the corresponding peripheral lumen, connect to a proximal element, and be fixed to the shaft 12 at a terminal T1. After the operation of the proximal element and / or implantation of the fixation device, each of the wires 92a, 92b is released from the shaft 12 (or a component near the shaft), so that the terminal T1 can detach from the proximal element and be removed along with the delivery device. In some examples, the delivery catheter 86 includes two additional locking wire lumens 94a, 94b (shown in gray). The locking wire lumens 94a and 94b may receive polymer wires that pull the wireform harness of the fixation device 14 to lock and unlock the fixation device. The locking wire lumens 94a and 94b may be positioned along the neutral axis of the delivery catheter 86.

[0055] If the catheter is curved, as shown in Figure 18, the arc length of the peripheral lumen on or near the outer curve of the curve is longer than the neutral axis of the delivery catheter 86 in order to maneuver the fixation device 14 to the lesion of the mitral valve or tricuspid valve. On the opposite side of the cross section, the arc length of the peripheral lumen on or near the inner curve of the curve is shorter than the neutral axis of the delivery catheter. This is partially illustrated by the blue and red lines in Figure 18. This difference in lumen arc length can cause variations in the line sag between the left and right proximal elements 16a and 16b.

[0056] Uneven wire slack can affect gripping performance when the delivery catheter is rotated in a situation where the surrounding lumen is in the same plane as the curved surface, and this is particularly likely to occur when the delivery catheter 86 and fixation device 14 need to be rotated to achieve orthogonality along the junction line in the treatment of A1 / P1 or A3 / P3 mitral valve lesions, or when the complex junction line of the tricuspid valve is handled by the fixation device. Uneven wire slack can also cause slow or confusingly unresponsive proximal element operation and / or performance problems when operating the proximal element, such as wire breakage.

[0057] In the illustrated example, a wire 90a with little or no slack may fail to fully or fully lower the proximal element 16a to grip the valve leaflet when the lever is actuated. In this example, the wire 90a positioned on the outer curve has reduced slack. When tension is applied to a "slack-free" wire 90a, the wire may be subjected to higher tensile loads and become more prone to failure, especially if the wire's lumen is precisely positioned on the outer curve by the rotation of the fixing device.

[0058] Conversely, the wire 90b in the inward curve may have excessive slack, which may prevent the proximal element 16b from fully rising when the user operates the lever to the fully retracted position. In this scenario, the proximal element 16b does not rise sufficiently to create space for inserting the valve leaflet under the arm 53, making it difficult to grasp the valve leaflet. In this scenario, the partially lowered proximal element 16b prevents the valve leaflet from entering the fixation device 14. Furthermore, this excessive slack scenario also makes it difficult for the user to completely disengage the proximal element 16b from the valve leaflet if the user needs to attempt to release the valve leaflet in a subsequent attempt to re-grasp it. In addition, the excessive slack may cause problems such as the wire 90b getting caught on friction elements, making it difficult to deploy / detach the fixation device 14 from the delivery catheter 86, and / or preventing the proximal element 16b from fully descending.

[0059] Note that in some cases, when the user rotates the fixation device 14 by approximately 90 degrees, the uneven slack between the two wires begins to correct. However, when the user rotates the fixation device 14 by another 90 degrees (i.e., a total of 180 degrees), the state of the wires reverses, and due to the difference in the arc of the delivery catheter at the inner and outer curves, the previously low-slack wire becomes a high-slack wire, and vice versa.

[0060] One solution to address the aforementioned uneven slack and to reduce the risk of difficult proximal element operation, wire capture, and / or wire breakage is to provide a delivery catheter 200 having a lumen (e.g., a spiral passage, or a passage that twists spirally inside the body of the catheter 200) that defines a curved passage. In some examples, the lumen is defined as a spiral passage or in one or more curved passages (e.g., a corkscrew shape) that are uniformly or non-uniformly wound around a cylinder. In some examples, the spiral passage forms at least one full revolution (e.g., 360 degrees) over a given axial distance, the distance of which can be selected as desired. The axial distance of each revolution may be the same as or different from that of the other revolutions. In addition, the radii of the portions of the spiral passage may be uniform or non-uniform. In other words, the spiral passage may be more tightly coiled from the proximal end to the distal end (for example, with a smaller radius), and vice versa.

[0061] As shown in Figure 19A, the generally tubular delivery catheter 200 may include a central lumen 209 and a body 205 (shown as transparent for ease of illustration) having a plurality of peripheral lumens 210a, 210b and locking line lumens 212a, 212b. This embodiment may be combined with any of the features, characteristics, methods or modifications described in any of the figures above. In this example, each lumen defines a spiral or vortex passage defined within the body 205 (shown as transparent) of the delivery catheter 200, and the spiral passages twist relative to each other. In one example, the spacing between the peripheral lumens 210a, 210b and the locking line lumens 212a, 212b is constant at each axial level or “slice” of the delivery catheter 200. In this configuration, each of the peripheral lumens 210a and 210b is positioned, due to the helical geometry of the passage, partially on the outer curve and partially on the inner curve of the delivery catheter, regardless of the shape or configuration taken by the delivery catheter. Without being bound by any particular theory, the helical passage is considered to ensure that sufficient slack is available in both wires coupled to the proximal element, regardless of the rotation angle of the fixation device 14. The helical passage defined by each of the peripheral lumens 210a and 210b may be formed, for example, by twisting the extruder during the extrusion process. In this example, two peripheral lumens 210a and 210b are formed, but it will be understood that any number of lumens, including a single peripheral lumen, two peripheral lumens, three peripheral lumens, four or more peripheral lumens, may be used. The helical passage may also help prevent twisting of the delivery catheter.

[0062] Figure 19B illustrates a series of cross-sections of the delivery catheter 200. In this example, the first peripheral lumen 210a is shaded gray in each cross-section to aid in understanding the disclosure. As shown, in the first cross-section, the first peripheral lumen 210a is positioned at 0 degrees, and each consecutive slice is rotated approximately 15 degrees in the "R" direction. In this example, since each consecutive slice is 1 mm apart, the helical passage defined by the first peripheral lumen 210a rotates 15 degrees for every 2 mm of axial length. The degree to which each helical passage rotates over a given axial length determines the degree of each helical path, which is "loosely wound" or "tightly wound". In some examples, the delivery catheter 200 may make a complete turn or rotation every 30 mm to 50 mm of axial length. In some cases, the delivery catheter 200 may complete a total of 1 to 20 turns along its axial length (e.g., more than one turn or more than five turns). In other words, the delivery catheter can have a pitch, which is the axial distance between two consecutive turns of the same peripheral lumen, and the pitch can be between one turn of the spiral lumen per inch and two turns of the spiral lumen per inch.

[0063] Referring here to Figure 20, Figure 20 illustrates an example of a fixation device 14 coupled to an intervention tool 10' having a shaft 12, a delivery catheter 200 covered by a sleeve 220, and one or more wires 90a, 90b that raise and lower proximal elements 16a, 16b through the delivery catheter 200. In this example, the delivery catheter 200 includes a central lumen 209 and several peripheral lumens 210a, 210b defining their respective helical pathways. The peripheral lumens 210a, 210b may be formed outside the central lumen 209 along their entire length. In Figure 20, for ease of illustration, the helical pathway of the peripheral lumen 210a is schematically shown with a dashed line, but in this example, it is understood that four twisted helical pathways are defined for the peripheral lumens 210a, 210b and the locking wire lumens 212a, 212b (see also Figure 19A). These spiral paths may be formed along the entire length of the delivery catheter 200 (Figure 20) or along a selected portion in various examples. In some examples, each peripheral lumen 210a, 210b forms at least one complete rotation. In some examples, each peripheral lumen 210a, 210b forms at least two or more complete rotations. In some examples, each peripheral lumen 210a, 210b forms at least one complete rotation (one full revolution) or two or more rotations in the bendable portion 230 of the delivery catheter 200. Figure 20 shows schematic diagrams of three cross-sections of the peripheral lumen 210a at various axial positions, where the peripheral lumen 210a is at the 12 o'clock position in the first cross-section, at the 1 o'clock position (e.g., rotated 30 degrees (+ / - 5 degrees) from the initial position) in the second cross-section, and at the 2 o'clock position (e.g., rotated 60 degrees (+ / - 5 degrees) from the initial position) in the third cross-section. The peripheral lumen 210a is shown in gray shading for illustrative purposes only. It is understood that each of the peripheral lumen 210a-210b may have the same diameter and shape as each other or as the locking line lumen 212a, 221b. Alternatively, in some examples, one or more of the peripheral lumen 210a, 120b may have a different shape and / or a different diameter than the other peripheral lumen or locking line lumen.In at least some examples, each peripheral lumen 210a, 120b has a diameter of 0.005–0.020 inches (e.g., approximately 0.016 inches). In at least some examples, each peripheral lumen 210a, 120b has a diameter of 0.020–0.025 inches (e.g., approximately 0.024 inches). In at least some examples, each wire has a diameter of 0.0040–0.0050 inches (e.g., approximately 0.0045 inches). In some examples, the ratio of the peripheral lumen diameter to the wire diameter is between 3:1 and 6:1 (e.g., a ratio of 4:1).

[0064] One modification of a delivery catheter for use with examples of the present disclosure is shown in Figure 21. In this example, the fixation device 14 is coupled to an intervention tool 10'' having a shaft 12, a delivery catheter 300 covered by a sleeve 320, and one or more wires 90a, 90b that raise and lower proximal elements 16a, 16b through the delivery catheter 300. In this example, the delivery catheter 300 includes a central lumen 309 formed in a body 305, two peripheral lumen 310a, 310b, and two locking wire lumen 312a, 312b. The peripheral lumen 310a, 310b and the two locking wire lumen 312a, 312b may be formed outside the central lumen 309 along their respective lengths. The peripheral lumens 310a and 310b differ from the examples in Figures 19A to 20 in that each peripheral lumen 310a and 310b first defines a first linear (straight) path 315 through the most distal part 330a of the delivery catheter 300, followed by a helical path 316 in the bendable part 330b, and then another or second linear (straight) path 317 in the nearest part 330c. In Figure 21, only one complete path is fully shown for the sake of illustration, but it should be noted that all paths may be configured similarly, but may be separated around the body 305 so that their defined helical paths twist relative to each other (see also Figure 19A). Thus, each path transitions from the straight path 315 to the helical path 316 and then back to the straight path 317. The helical path is limited to the bendable portion 330b of the delivery catheter 300 (it is confined to the range of the bendable portion). Without being bound by any particular theory, such a configuration is thought to eliminate the risk of uneven slack while minimizing any additional friction inside the delivery catheter by applying the helical portion only where necessary (e.g., the bendable area).

[0065] It should be understood that the embodiments described herein are merely illustrative of the principles and applications of the disclosure. For example, the system may include any number of peripheral lumens or any number of transitions between helical and linear paths. In addition, the system may include both helical and non-helical paths that include linear paths. Furthermore, certain components are optional, and the disclosure assumes various configurations and combinations of the elements disclosed herein. It should be understood that numerous modifications can be made to the exemplary embodiments, and other arrangements can be devised without departing from the spirit and scope of the disclosure as defined by the appended claims.

[0066] The disclosures herein are described with reference to specific embodiments, but it should be understood that these embodiments are merely illustrative of the principles and applications of the disclosure. Therefore, it should be understood that numerous modifications can be made to the exemplary embodiments, and other arrangements can be devised without departing from the spirit and scope of the disclosure as defined by the appended claims.

Claims

1. A delivery catheter defining a central lumen and a plurality of peripheral lumens, wherein at least one of the plurality of peripheral lumens defines a spiral path along a portion of the delivery catheter; At least one wire disposed inside at least one of the plurality of peripheral lumens, configured to operate a medical device and An intervention tool equipped with these features.

2. The intervention tool according to claim 1, wherein the plurality of peripheral lumens include two peripheral lumens spaced equally apart from each other, and the at least one wire includes two wires.

3. The intervention tool according to claim 2, wherein the two peripheral lumens each extend along corresponding spiral pathways.

4. The intervention tool according to claim 1, wherein the helical path is limited to the bendable portion of the delivery catheter.

5. The intervention tool according to claim 1, wherein the spiral path extends along the entire length of the delivery catheter.

6. The intervention tool according to claim 1, wherein the delivery catheter includes a nearest portion, a bendable portion, and a distal portion, and the helical path of the at least one peripheral lumen is disposed within the bendable portion.

7. The intervention tool according to claim 6, wherein the at least one peripheral lumen extends along a first linear path in the nearest part and a second linear path in the most distal part.

8. The intervention tool according to claim 1, wherein the spiral path of the at least one peripheral lumen has a pitch between one turn per inch and two turns per inch.

9. The intervention tool according to claim 1, wherein the spiral path of the at least one peripheral lumen forms multiple complete circumferences.

10. The intervention tool according to claim 1, wherein the spiral path of the at least one peripheral lumen forms more than five complete circumferences.

11. The intervention tool described in claim 1, A medical device comprising two arms and two proximal elements, wherein at least one of the proximal elements is coupled to at least one wire of the intervention tool, and A system that includes these features.

12. The system according to claim 11, wherein the at least one wire comprises two wires, each of which is coupled to one of the two proximal elements selected by the system.

13. The system according to claim 12, wherein the two wires comprise a wire.

14. The system according to claim 12, wherein the two wires are configured to actuate the two proximal elements and move them relative to the two arms.

15. The system according to claim 11, wherein the medical device is a fixing device.

16. The system according to claim 11, wherein the medical device is a mitral valve clip.

17. A method for operating a medical device, An intervention tool is provided comprising a delivery catheter that defines a central lumen and a plurality of peripheral lumens, wherein at least one of the plurality of peripheral lumens defines a spiral path along a portion of the delivery catheter, and at least one wire disposed inside the at least one of the plurality of peripheral lumens. To activate the medical device by pulling on at least one of the aforementioned wires Methods that include...

18. The method according to claim 17, wherein the medical device comprises two arms and two proximal elements, and pulling the at least one wire involves moving the first of the two proximal elements with the at least one wire.

19. The method according to claim 17, wherein the medical device comprises two arms and two proximal elements, the at least one wire comprising two wires, and pulling the at least one wire involves moving each of the two proximal elements independently.

20. The method according to claim 17, wherein the plurality of peripheral lumens comprises two peripheral lumens spaced equally apart from each other, and pulling the at least one wire involves passing the at least one wire through one of the two peripheral lumens.

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