Fastening device and method for endoluminal systems

Abstract

The present disclosure provides embodiments of devices useful for structural remodeling of various portions of the cardiovascular system, particularly the heart.SOLUTION: Some of the disclosed devices relate to the RAMIN procedure ("Remodeling and Ablation Using Intermyocardial Navigation"). RAMIN procedures as described herein represent a new family of non-surgical catheter-based procedures for achieving the desired ablation, drug delivery, reshaping, pacing, and related structural cardiac interventional procedures.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 050,270, filed July 10, 2020. The above-referenced patent application is incorporated herein by reference for any purpose.

[0002] FIELD OF THE DISCLOSURE The present disclosure relates generally to interventional devices for altering the shape of a portion of a luminal system. [Background technology]

[0003] Many prior art devices and systems exist for cardiac remodeling. The present disclosure solves these and other problems. Summary of the Invention

[0004] Advantages of the present disclosure will be set forth in and will be apparent from the following description. Additional advantages of the present disclosure will be realized and attained by the methods and systems particularly pointed out in the specification and claims, as well as the accompanying drawings.

[0005] In some implementations, the present disclosure provides an implant configured to pass through a passageway defined through tissue surrounding a ventricle of a heart. The implant includes an elongated flexible tether having opposite ends forming a loop and a locking body disposed on each end of the tether. The locking body can be configured to releasably engage the elongated flexible tether. The implant can further include first and second tubular limbs extending outward from the lock toward each other along the loop and on the elongated flexible tether.

[0006] In some implementations, the implant is structurally compliant or flexible, allowing it to change length in response to cardiac movement. This can be achieved in various ways, such as by including one or more implant segments that expand and contract in the transverse direction when placed under increasing tension. The implant material may be selected to achieve this. In some implementations, one or more implant segments may be formed from a compliant material in the shape of a leaf spring or tension spring, or may have a helical shape that slightly unwinds and expands when placed under tension. In another implementation, the implant body may include an elongated tether sewn through or along the implant body to form, for example, a sine wave, sawtooth, or square wave shape. When the elongated tether is under tension, one or more implant body segments can contract axially and expand radially.

[0007] If desired, the first and second tubular limbs may have different diameters. The first and second tubular limbs may have tapered distal ends. The distal end of the first tubular limb may slide within the distal end of the second tubular limb along the loop of the elongate flexible tether such that the first and second tubular limbs overlap. At least one of the first and second tubular limbs may include a plurality of radiopaque markers disposed therealong. The plurality of radiopaque markers may be arranged in a predetermined pattern along at least one of the first and second tubular limbs to facilitate measurement of the implant under visualization.

[0008] In some implementations, at least one of the first and second tubular limbs may include at least one pacing electrode for stimulating cardiac tissue. The implant may further include a controller coupled to the at least one pacing electrode for providing at least one of pacing, defibrillation, measurement, and control. If desired, the elongated flexible tether may include an antenna, such as a loop antenna, for conducting signals to and from the controller. If desired, the implant may further include a controller and a reservoir containing a beneficial agent, the controller being coupled to a dispenser coupled to the reservoir for dispensing the beneficial agent. The beneficial agent may include a drug. The beneficial agent may include a gene therapy material. The beneficial agent may include living cells seeded at at least one location in the damaged heart. At least one of the first and second tubular limbs may include at least one sensor for sensing at least one biological parameter. The at least one sensor may include at least one pressure sensor for sensing blood pressure. The at least one sensor may include at least one of a chemical sensor, a distance sensor, a sensor having circuitry for detecting electrophysiological data, a motion sensor, and a position sensor. The elongated flexible tether may include a radiopaque material along the elongated flexible tether. The elongated flexible tether may be a hollow braided suture, and the radiopaque material within the elongated flexible tether may include a radiopaque wire disposed within a heat-shrinkable polymer tube residing within a hollow core of the elongated inner tether. The implant lock may define at least one distal opening therein. The at least one distal opening may be connected to the first and second tubular limbs.

[0009] Further according to the present disclosure, there is provided an implant including an elongated inner tether having a proximal end and a distal end. The proximal end of the elongated inner tether may terminate in a loop. The implant may include an outer tubular body surrounding the elongated inner tether along at least a portion of the inner tether. The outer tubular body may have a shorter length than the elongated inner tether. In some implementations, the outer tubular body may be configured to shorten in length and increase in dimension in a passage direction when compressed axially. If desired, the outer tubular body may include a braided structure. In some implementations, the elongated inner tether may be threaded intermittently through the outer tubular body. In some implementations, the outer tubular body may include a resilient member. If desired, the outer tubular body may include a shape memory material, a resilient member, and / or a coil spring. In some implementations, the outer tubular body may include a plurality of radiopaque markers along its length. A plurality of radiopaque markers disposed along the outer tubular body may be spaced at predetermined intervals to facilitate measurement of the implant under visualization.

[0010] In some embodiments, the outer tubular body may include at least one pacing electrode for stimulating cardiac tissue. If desired, the implant may further include a controller coupled to the at least one pacing electrode to provide at least one of pacing, defibrillation, measurement, and control. The implant may include an antenna, such as a loop antenna or a dipole antenna, for conducting signals to and from the controller. If desired, the implant may include the controller and a reservoir containing a beneficial agent. The controller may be coupled to a dispenser coupled to the reservoir for dispensing the beneficial agent. If desired, the beneficial agent may include one or more of a drug, a gene therapy material, and living cells seeded at least one location of the damaged heart.

[0011] In some implementations, the outer tubular body may include at least one sensor for sensing at least one biological parameter. The at least one sensor may include at least one pressure sensor for sensing blood pressure. The at least one sensor may include at least one of a chemical sensor, a distance sensor, a sensor having circuitry for detecting electrophysiological data, a motion sensor, and a position sensor.

[0012] In some implementations, the elongate inner tether can include a radiopaque material along it. The elongate inner tether can be a hollow braided suture, and the radiopaque material within the elongate inner tether can include a radiopaque wire disposed within a heat-shrink polymer tubing that resides within the hollow core of the elongate inner tether. The implant can further include an implant lock that secures the implant in a loop configuration.

[0013] In some embodiments, the present disclosure provides a method for reducing the size of a patient's heart. The method may include advancing a guidewire into the patient's circulatory system and into the patient's heart, advancing the guidewire through the myocardium to define a passage around a portion of the heart between an outer surface of the heart and an inner surface of the heart, replacing the guidewire with an implant including a tension element such that the tension element passes through the passage, advancing a lock over the tension element, applying tension to the tension element to change the size of the portion of the heart, and securing the lock to maintain tension on the tension element.

[0014] In some embodiments, the method may further include unlocking the lock, adjusting the tension of the tension element, and re-locking the lock. In some implementations, the diameter of the tension element may be larger than the diameter of the guidewire. If desired, the lock may include two elongated tubular limbs coupled to the lock body, and the method may further include advancing the two elongated tubular limbs along the tension element to increase the effective diameter of the tension element. The distal ends of the two elongated tubular limbs may be configured to slide past and overlap each other as the tension element passes through. The first distal end of the two elongated tubular limbs may be configured to be received within the second distal end of the two elongated tubular limbs.

[0015] In some implementations, the lock may include an electrode array coupled to a signal generator configured to provide cardiac pacing, and the method may further include performing a cardiac pacing function using the electrode array and the signal generator. The pacing function may perform depolarization of the myocardium. In some implementations, the pacing function may include synchronously depolarizing the basal left ventricle. If desired, the pacing function may include applying the pacing function to the patient's HIS bundle.

[0016] In some implementations, the method may further include delivering a beneficial agent to the target location in the patient's myocardium. In some implementations, delivering the beneficial agent may include performing a chemical ablation procedure to remove the myocardium. In some implementations, the beneficial agent may include, for example, one or more of: (i) a pharmaceutical composition, (ii) light, and (iii) ultrasound energy.

[0017] In some implementations, the elongated passage through the myocardium passes through a portion of the septum. If desired, the method may further include delivering a beneficial agent, as described elsewhere herein, to a target location in the patient's septum. If desired, delivering the beneficial agent may include performing a chemical ablation procedure to remove the septum.

[0018] In other implementations, the method may include defining an elongated passageway through a path around a portion of at least one of the patient's ventricles. If desired, the elongated passageway may pass around a portion of both of the patient's ventricles. If desired, the elongated passageway may surround the one of the patient's ventricles at a base level. In other implementations, the elongated passageway may surround the one of the patient's ventricles at a mid-level of the myocardium. If desired, the elongated passageway may surround the patient's left ventricle.

[0019] In some implementations, the method may include directing a second tension element through the patient's myocardium and applying tension to the second tension element to further alter the size of the patient's heart. For example, multiple independent elongated passages may be defined and an implant may be positioned along each passage.

[0020] In some embodiments, the guidewire may include an electrical conductor coated with a dielectric coating. An exposed region of the electrical conductor near a distal portion of the guidewire may be exposed and not coated with a dielectric coating, and the elongated passage may be formed, at least in part, by ablating tissue by applying power to the electrical conductor. If desired, the power may be applied in a monopolar operating mode. In some implementations, the power may be applied in a bipolar operating mode. A return path for the current may be defined by a second conductor disposed near the exposed region of the electrical conductor. The exposed region of the electrical conductor may be located at the distal tip of the guidewire. The exposed region of the electrical conductor may be located on a side of the guidewire near the distal tip of the guidewire. The exposed region of the electrical conductor may be located on a side of the guidewire at the distal tip of the guidewire. If desired, the distal region of the guidewire may include a bend that points away from the central longitudinal axis of the guidewire. In some implementations, the guidewire or a support catheter supporting the guidewire may define a longitudinal channel in at least a portion thereof configured to emit fluid from a distal end of the longitudinal channel to facilitate tissue ablation, and the method may further include flowing pressurized fluid through the longitudinal channel to assist in defining the elongated passage.

[0021] In some implementations, the elongated passage may be formed at least in part by inflating an inflatable balloon coupled to a catheter positioned within the myocardium. The balloon may be introduced into an opening created in the myocardium by a guidewire. The balloon may be inflated to form an enlarged entrance into the myocardium to allow introduction of at least one support catheter into the myocardium. The balloon may be coupled to an inflation catheter that is at least partially slidably positioned over the guidewire.

[0022] In some implementations, the method includes using a snare catheter to secure the distal end of the guidewire, the snare catheter including an expandable member disposed within the snare, and expansion of the expandable member expands the snare. This may be done to bluntly dissect surrounding tissue to create space for the snare. The balloon may be deflated after dissection is performed, after which the snare catheter may collapse to capture the guidewire. For example, this guidewire capturing step may occur within the myocardium. Alternatively, it may be accomplished outside the myocardium. The elongated passage may be formed at least in part by passing a pressurized fluid to a target location within the myocardium.

[0023] Advancing the guidewire into the myocardium may include advancing an afferent accessor catheter over the guidewire to assist in directing the guidewire into the myocardium. The afferent accessor catheter may include a radiopaque marker near its distal end to indicate the relative rotational position of the afferent accessor catheter.

[0024] In some implementations, advancing the guidewire through the myocardium may include defining a passage by advancing the guidewire through myocardial tissue, which is at least partially ablated to define the passage. For example, the myocardial tissue may be ablated by applying electrical energy through the guidewire to energize an exposed, electrically non-insulated distal surface of the guidewire. The method may further include advancing a first support catheter disposed around the guidewire distally along a portion of the passage formed during the ablation step to surround the distal portion of the guidewire and provide column strength to the guidewire. These steps may be repeated until the passage through the myocardial tissue is formed and completed.

[0025] In some implementations, the distal portion of the guidewire may include at least one visually enhanced marker visible in a visualization mode. A related method may include visualizing the guidewire and myocardium in a visualization mode during a procedure to aid in controlling the advancement of the guidewire through myocardial tissue. The method may further include advancing a second support catheter over the first support catheter to further enlarge the passageway. Furthermore, the method may further include withdrawing the first support catheter over the guidewire, leaving the guidewire and the second support catheter in place. As a result, an annular space is formed around the guidewire within the second support catheter, and a second guidewire can be inserted through the second support catheter in parallel with the first guidewire. At this point, the method may include withdrawing the first guidewire and the second support catheter over the second guidewire. The first support catheter may then be advanced over the first guidewire, and the second support catheter may again be advanced over the first support catheter.

[0026] In some implementations, the formed passage defines a complete loop that crosses itself. The distal end of the first guidewire may then be advanced distally to re-enter the passage and complete the loop. A snare catheter may then be introduced over the second guidewire to a position near where the distal end of the first guidewire re-entered the passage. The snare catheter may then be actuated to capture the distal end of the first guidewire, and the first guidewire may be withdrawn from the patient using the snare catheter so that the first guidewire defines a loop around the passage. The method may further include exteriorizing the proximal and distal ends of the first guidewire. The distal end of a tension element may then be coupled to the proximal end of the first guidewire. The tension element may then be advanced around the path defined by the first guidewire until the tension element is positioned to allow a lock to be introduced onto the tension element.

[0027] The present disclosure further provides a method of treating a patient's vascular system, the method including: advancing a guidewire into the patient's circulatory system and a wall structure of the patient's vascular system; advancing the guidewire through the wall structure to define a passage along the wall structure between an outer surface of the wall structure and an inner surface of the wall structure; interchanging the guidewire and the tension element so that the tension element passes through the passage; advancing a lock onto the tension element; tensioning the tension element; and securing the lock onto the tension element. In some implementations, securing the tension element in place may include advancing a knot along the tension element. The tension element may include a suture. The knot may be driven onto first and second ends of the tension element to form a tension loop. Advancing the lock and securing the lock may include advancing a crimp onto the first and second ends of the tension element to form the tension loop and crimping the crimp into place.

[0028] Preferably, the procedures provided herein are percutaneous, and the tension element may be introduced via the patient's circulatory system. In some implementations, the procedure may include percutaneously advancing a guidewire through a wall of a cardiac blood vessel and through the myocardium to define an elongated passageway. The procedure may include advancing the guidewire through and around the wall of the blood vessel to define the elongated passageway. The blood vessel may include the abdominal aorta, and the passageway may be defined through a healthy portion of the abdominal aorta located above the aneurysm, and the method may further include coupling the tension element to the implant positioned in the abdominal aorta to prevent the implant from migrating. The implant may be positioned to at least partially or completely span a compromised region of the aorta, such as a region of the aorta containing an aneurysm.

[0029] In some implementations, an implant may be introduced that includes a single limb or outer tubular member, optionally including a tension element disposed therein. The method may further include axially shortening the outer tubular member by applying tension to the tension tether. The outer tubular member's dimension in the passage direction is configured to expand when axially contracted, thereby increasing its effective surface area, spreading stress over a larger area of ​​the myocardium, and preventing the implant from pulling and shearing myocardial tissue after implantation. Such procedures typically begin with a resection process, such as those disclosed herein, to define a passageway for receiving the implant, such as by using one or more support catheters. Nevertheless, when exchanging a guidewire for a tension element, the support catheter is already present or introduced over the guidewire. The distal end of the guidewire, captured using a snare catheter, is externalized and coupled to the distal end of the tension tether, such as by a crimp connection or other connection. The tension tether is then withdrawn through the support catheter to allow the distal end of the tension tether to be similarly externalized. In some embodiments, the distal end of the retention tether may be coupled to the distal end of the guidewire, and the retention tether may be withdrawn through the support catheter. The proximal end of the retention tether may be attached to the distal end of the outer tubular member. The method may further include pulling the outer tubular member along a path defined by the support catheter while the support catheter is withdrawn, thereby positioning the outer tubular member at a desired anatomical location. The distal end of the tension tether may be guided through a proximal loop formed at the proximal end of the tension tether. The outer tubular member may be positioned between the proximal loop at the proximal end of the outer tubular member and a point where the proximal loop at the distal end of the tether and the distal end of the tension tether intersect.

[0030] The present disclosure further provides a guidewire comprising an electrically conductive core member surrounded by an insulating jacket. The guidewire may define an electrically non-insulated, exposed distal end face disposed in a curved distal portion facing away from a central longitudinal axis of the proximal portion of the guidewire. The electrically non-insulated, exposed distal end face may be disposed at a distal tip of the guidewire and may be axisymmetric about the longitudinal axis of the curved distal portion of the guidewire.

[0031] The electrically non-insulated exposed distal surface may be located at the distal tip of the guidewire and may not be axially symmetrical about the longitudinal axis of the curved distal portion of the guidewire. The electrically non-insulated exposed distal surface may be located near the distal tip of the guidewire and may not be axially symmetrical about the longitudinal axis of the curved distal portion of the guidewire. The present disclosure further provides a catheter comprising the above-described guidewire disposed within a tubular member. The tubular member may include an exposed lead at its distal end coupled to a conductor extending to a proximal end region of the tubular member.

[0032] Electrosurgical systems are also provided that include a power source operably coupled to the guidewire and are configured to operate in a monopolar operating mode. Also provided are electrosurgical systems that include a power source operably coupled to the catheter, operate in a bipolar operating mode, and are configured to complete an electrical circuit from the distal tip of the guidewire to the distal tip of the tubular member. The guidewire and related methods may include detecting and processing electrical signals received from cardiac tissue. Similarly, these devices may be required to record or monitor intracardiac electrograms to aid in guiding navigation through tissue. The catheter of the system may be coupled to a tube, such as a hypotube, which in turn may be coupled to a fluid source. Related methods are provided for at least partially ablating tissue by using the catheter as described above to force fluid from the fluid source out the distal end of the hypotube. Saline or contrast may similarly be forced out the distal end of the hypotube.

[0033] The present disclosure further provides a catheter comprising an elongate tubular member coupled to an expandable member near a distal end of the catheter and a reservoir of inflation fluid, and a collapsible snare surrounding the expandable member, wherein inflation of the expandable member with inflation fluid expands the collapsible snare. The collapsible snare may be a single-loop snare. The collapsible snare may be a multiple-loop snare. The collapsible snare may be configured to remain open after the expandable member is deflated.

[0034] The present disclosure further provides a tension element expandable from a first, smaller effective diameter to a second, larger effective diameter. The tension element may include a plurality of longitudinal rails configured to separate from one another to expand to the larger effective diameter. The tension element may include a core member and at least one tubular member disposed around the core member to increase the effective diameter of the tension element. The tension element may further include a plurality of markers along the tension element that are visible under at least one visualization modality. The tension element may further include "L"-shaped locks disposed on the first and second ends of the tension element.

[0035] It is understood that the foregoing general description and the following detailed description are exemplary and are intended to provide further explanation of the disclosed embodiments. The accompanying drawings, which are incorporated in and constitute a part of this specification, are included to illustrate and provide a further understanding of the disclosed methods and systems. The drawings, together with the description, serve to explain the disclosed principles. [Brief explanation of the drawings]

[0036] [Figure 1] FIG. 1 illustrates the use of a first implant according to the present disclosure. [Figure 2] FIG. 2 illustrates the use of a first implant according to the present disclosure. [Figure 3] FIG. 3 illustrates the use of a first implant according to the present disclosure. [Figure 4]FIG. 4 illustrates the use of a first implant according to the present disclosure. [Figure 5] FIG. 5 illustrates the use of a first implant according to the present disclosure. [Figure 6] FIG. 6 illustrates the use of a first implant according to the present disclosure. [Figure 7] FIG. 7 illustrates the use of a first implant according to the present disclosure. [Figure 8] FIG. 8 illustrates the use of a second implant according to the present disclosure. [Figure 9] FIG. 9 illustrates the use of a second implant according to the present disclosure. [Figure 10] FIG. 10 illustrates the use of a second implant according to the present disclosure. [Figure 11] FIG. 11 illustrates the use of a second implant according to the present disclosure. [Figure 12] FIG. 12 illustrates the use of a second implant according to the present disclosure. [Figure 13] FIG. 13 illustrates the use of a second implant according to the present disclosure. [Figure 14] FIG. 14 illustrates the use of a second implant according to the present disclosure. [Figure 15] FIG. 15 illustrates the use of a second implant according to the present disclosure. [Figure 16] FIG. 16 illustrates the use of a second implant according to the present disclosure. [Figure 17] FIG. 17 illustrates the use of a second implant according to the present disclosure. [Figure 18] FIG. 18 illustrates the use of a second implant according to the present disclosure. [Figure 19] FIG. 19 illustrates the use of a second implant according to the present disclosure. [Figure 20] FIG. 20 illustrates the use of a second implant according to the present disclosure. [Figure 21] FIG. 21 illustrates the use of a second implant according to the present disclosure. [Figure 22]FIG. 22 shows an additional device according to the present disclosure. [Figure 23] FIG. 23 illustrates an additional device according to the present disclosure. [Figure 24] FIG. 24 shows an additional device according to the present disclosure. [Figure 25] FIG. 25 illustrates an exemplary method aspect according to the present disclosure. [Figure 26] FIG. 26 illustrates an exemplary method aspect according to the present disclosure. [Figure 27] FIG. 27 illustrates an exemplary method aspect according to the present disclosure. [Figure 28] FIG. 28 illustrates an exemplary method aspect according to the present disclosure. [Figure 29] FIG. 29 illustrates an exemplary method aspect according to the present disclosure. [Figure 30] FIG. 30 illustrates an exemplary method aspect according to the present disclosure. [Figure 31] FIG. 31 illustrates an exemplary method aspect according to the present disclosure. [Figure 32] FIG. 32 illustrates an exemplary method aspect according to the present disclosure. [Figure 33] FIG. 33 illustrates an exemplary method aspect according to the present disclosure. [Figure 34] FIG. 34 illustrates an exemplary method aspect according to the present disclosure. [Figure 35] FIG. 35 illustrates an exemplary method aspect according to the present disclosure. [Figure 36] FIG. 36 illustrates an exemplary method aspect according to the present disclosure. [Figure 37] FIG. 37 illustrates an exemplary method aspect according to the present disclosure. [Figure 38] FIG. 38 illustrates an exemplary method aspect according to the present disclosure. [Figure 39] FIG. 39 illustrates an exemplary method aspect according to the present disclosure. [Figure 40] FIG. 40 illustrates an exemplary method aspect according to the present disclosure. [Figure 41] FIG. 41 illustrates an exemplary method aspect according to the present disclosure. [Figure 42]FIG. 42 illustrates an exemplary method aspect according to the present disclosure. [Figure 43] FIG. 43 illustrates an exemplary method aspect according to the present disclosure. [Figure 44] FIG. 44 illustrates an exemplary method aspect according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0037] Reference will now be made in detail to preferred embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. The method and corresponding steps of the disclosed embodiments will be described together with a detailed description of the system.

[0038] The present disclosure provides device embodiments useful for structural remodeling of various portions of the cardiovascular system, particularly the heart, although it is understood that the disclosed techniques can be used to similarly remodel other anatomical portions, such as the aorta, other lumens, blood vessels, and portions of organs.

[0039] Some of the disclosed devices relate to RAMIN procedures ("Remodeling and Ablation with Intramyocardial Navigation"). RAMIN procedures as described herein represent a new family of non-surgical catheter-based procedures for achieving desired ablation, drug delivery, reshaping, pacing, and related structural cardiac interventional procedures.

[0040] In transcatheter mitral annuloplasty, such as that described in U.S. Pat. No. 10,433,962 (incorporated herein by reference in its entirety), a guidewire navigates the coronary vein branches, and a guidewire loop encircles the mitral annulus and left ventricular outflow tract, applying tension to allow replacement with a permanent implant to alter myocardial and mitral valve function.

[0041] In the implementation of the MIRTH (Myocardinal Intramural Restraint with Endovous Interstitial Therapy) procedure described herein, a guidewire is navigated within the left ventricular myocardium to form a deep subepicardial loop that encircles the left ventricle to apply tension to restrain or remodel the heart when it is pathologically dilated. The encirclement can be at the base, mid-myocardium, or any location. Once the guidewire navigates this trajectory, it is exchanged for a tensioning element (e.g., an implant with a tension tether) and a device that adjusts or maintains its tension. The subepicardial trajectory eliminates the risk of coronary vascular occlusion and reduces the risk of high-grade atrioventricular block due to tensioning. Furthermore, the subepicardial tensioning element avoids the risk of pull-through associated with anchor-based annuloplasty and ventriculoplasty devices.

[0042] The pathway or trajectory created using the MIRTH procedure allows for the further use of MIRTH-based pacing to provide permanent cardiac pacing or cardiac resynchronization therapy when the native cardiac conduction system fails at the AV node, His bundle, or other levels requiring permanent pacing (where right ventricular-only pacing causes or worsens cardiomyopathy). In the implementation of the SCIMITAR procedure (Suture via Coronary Sinus with Interstutial Myocardinal Navigation for MItral and Tricuspid Annular Reduction), a pathway may be created that can encompass both ventricles.

[0043] In the CEVICHE procedure (Catheter Endo-Venous myocardinal Interstitial CHEmoablation), as described herein, an intraseptal fastening trajectory is navigated to deliver a catheter for ablative agent delivery ("chemoablation"), such as ethanol or glacial acetic acid, to remove the septum in patients at risk for left ventricular outflow tract obstruction complicating transcatheter mitral valve implantation or in patients with hypertrophic cardiomyopathy. The CEVICHE procedure may also be used to ablate other pathological targets, including critical reentrant isthmuses in ventricular tachycardias or subvalvular tissue or membranes causing subvalvular pulmonary or aortic stenosis. The procedures described herein distribute load relatively evenly around the myocardium, minimizing so-called "cheese cuts" or erosions.

[0044] In some implementations, the present disclosure provides an implant configured to pass through a passageway defined through tissue surrounding a ventricle of the heart.

[0045] For purposes of illustration and not limitation, an implant designed for use in a MIRTH procedure is illustrated as embodied herein and shown in FIG. 1 . The MIRTH implant comprises an elongated flexible tether having two ends (illustrated as "radiopaque sutures" that terminate in a loop) and an adjustable lock having a lock body disposed on the two ends of the tether. The lock body may be configurable to releasably engage the elongated flexible tether using a mechanism and lock delivery catheter similar to those illustrated in U.S. Pat. No. 10,433,962. The implant may further comprise first and second tubular limbs extending outward (downward, as shown) from the lock toward each other along the loop and on the elongated flexible tether, as shown. As shown, each limb comprises an approximately 90-degree bend immediately after exiting the lock body to facilitate proper alignment of the lock and limb relative to the surrounding anatomy. The implant lock may define at least one distal opening therein. As shown, at least one distal opening may be connected to the first and second tubular limbs.

[0046] If desired, the first and second tubular limbs may be of different diameters, as shown. As shown in FIG. 1, the first and second tubular limbs may have tapered distal ends. As shown in FIG. 3, the limbs may be advanced along the suture until they contact each other and begin to overlap. As shown in FIG. 3, the distal end of the first tubular limb may slide within the distal end of the second tubular limb along the loop of the elongated flexible tether so that the first and second tubular limbs overlap. At least one of the first and second tubular limbs may include multiple radiopaque markers along it. If desired, the inner tether or suture may also include radiopaque markers at regular intervals along it. For example, FIG. 3 shows a marker band along the left, smaller diameter limb. As shown, multiple radiopaque markers may be arranged in a predetermined pattern along at least one of the first and second tubular limbs to facilitate measurement of the implant under visualization. This may be done, for example, to estimate the circumference or length of the loop implant at the time of placement. This may be accomplished by additionally or alternatively including radiopaque markers along the inner tether. As will be appreciated, both limbs may be provided with marker bands, if desired.

[0047] To aid in determining the relative position of the components, it is useful to include marker bands along different components of any implant defined herein. However, further in accordance with the present disclosure, this may also be done to enable the surgeon to quantify the amount of contraction or tightening of the implant when tensioning the tensioning tether during installation. For example, in the illustrated example of a MIRTH implant, the surgeon installing the implant can place the implant in place and introduce a lock into the limb attached to the tensioning tether and into the patient's heart. Once the lock is in place, the relative positions of the marker bands on the lock and / or limb of the inner tether can be recorded. Next, tensioning the tensioning tether by pulling the tether through the lock to hold it in place reduces the circumferential length of the implant and causes the marker bands to move relative to each other. Applying a predetermined amount of tension can lock the implant, and the amount the implant has shortened circumferentially can also be recorded. Alternatively, the implant can be circumferentially contracted a predetermined amount simply by referencing the relative positions of the marker bands. Thus, once the surgeon has recorded the desired distance of retraction, they can lock the location and lock the tether in place.

[0048] As disclosed herein, the lock couples the free ends of the tensioning elements and pulls them in opposite directions. Additionally, the lock provides a dock for delivery and adjustment and can take a variety of configurations. For example, while the MIRTH implants in FIGS. 1-4 are illustrated as having a wishbone shape combined with limbs, this need not be the case. For the illustrations in FIGS. 8-21, the lock may slide over a single tether, with no extending limbs or with one limb. Alternatively, the lock may be a crimp, if desired. Similarly, the lock may include an "L"-shaped intramyocardial lock that shifts tension from an intramyocardial location to an epicardial or right atrial location. The implants in FIGS. 8-21 may be similarly delivered over one of a pair of tethers, with the outer tubular member attached or pushed over one of the tethers, and both tethers threaded through the lock.

[0049] As shown in FIG. 3 , for example, the tubular limb shown on the right includes multiple pacing electrodes formed therein that stimulate cardiac tissue. While not explicitly shown, the implant may further include a controller coupled to at least one pacing electrode that provides at least one of pacing, defibrillation, measurement, and control. For example, the controller may be disposed within or coupled to the lock body, if desired. If desired, the elongated flexible tether may form an antenna, such as a loop antenna, that conducts signals to and from the controller. It is understood that one or more electrical conductors may be embedded in the suture or tether to form an antenna, such as a loop antenna or a dipole antenna. Alternatively, the lock body and first and second limbs may include conductive paths that form one or more conductive loops that can function as antennas when coupled to the controller.

[0050] In some embodiments, the pacing device may comprise a ring electrode array that is effectively implanted deep into the basal left ventricular myocardium along the MIRTH trajectory, allowing for synchronous activation (also referred to as depolarization) of healthy or diseased myocardium in a desired base-to-apex sequence. The ring electrodes may comprise multiple electrodes (e.g., 1, 2, or 3 mm apart) in a unipolar or multipolar configuration. Because the entire array is implanted deep within the myocardium, this cannot be achieved with surgery or epicardial or endocardial implants.

[0051] The problem of dyssynchrony with right ventricular pacing is resolved by synchronous depolarization of the entire basal left ventricle. The problem of unreliable capture and resynchronization using standard left ventricular leads (due to location, fibrosis, heterogeneous cardiomyopathy, and variable target vein location) is resolved by implanting a deep proximal circumferential ring electrode along the MIRTH location. The problem of physical lead instability with direct His bundle pacing electrodes is resolved by using a deeply implanted array electrode. The problem of high stimulation threshold variability with direct His bundle pacing electrodes is resolved by using a deep intramyocardial array electrode. The problem of unintended induction of tricuspid regurgitation with pacemaker leads is resolved by using a deep MIRTH electrode array. The problem of unstable and bulky defibrillation electrodes that can cause tricuspid regurgitation is resolved by using a deep MIRTH electrode array. The problem of endocarditis due to interaction of conventional pacing / defibrillation leads with tissues and valves is mitigated by a deep MIRTH electrode array.

[0052] The implant may additionally or alternatively include a controller and a reservoir (not shown) containing a beneficial agent, and the controller may be coupled to a dispenser (not shown) coupled to the reservoir for dispensing the beneficial agent. The beneficial agent may include one or more of a drug, a gene therapy material, live cells seeded at least one location in the damaged heart, and the like. At least one of the first and second tubular limbs may include at least one sensor (not shown) for sensing at least one biological parameter. For example, the sensor may include at least one of a pressure sensor for sensing blood pressure, a chemical sensor, a distance sensor, a sensor having circuitry for detecting electrophysiological data, a motion sensor, and a position sensor.

[0053] If desired, the elongated flexible tether may include a radiopaque material along it. The elongated flexible tether may include a hollow braided suture, and the radiopaque material within the elongated flexible tether may include a radiopaque wire that is in turn disposed within a heat-shrinkable polymer tube that resides within the hollow core of the elongated inner tether. Additionally or alternatively, the braided suture may be doped with a powdered radiopaque material. Figure 4 shows the relative placement of the implant around the left ventricle before tightening.

[0054] As a further example, the inner tether used to tension and secure the implant in place may be made from a 1-2 mm ultra-high molecular weight polyethylene ("UHMWPE") coreless round braid from DSM, Dyneema, or Teleflex. In some implementations, the tension tether can be loaded with at least 20 wt% bismuth to improve radiopacity. For example, the tension tether can be loaded with about 20 to about 70 wt%, or any amount in 1 wt% increments therebetween, of bismuth or barium sulfate. Additional or alternative radiopaque materials, such as tungsten, tantalum, and barium sulfate, may be incorporated into the tension tether or other portions of the implant or delivery device or other device defined herein. These materials may be incorporated, for example, as drawn metal (e.g., platinum, or other radiopaque material) wires incorporated into the braid, such as by weaving or by directing the drawn wire along a central channel defined within the tether. In a further embodiment, ultra-high molecular weight polyethylene may be used as the tension tether material to improve creep resistance, preferably in a size of 1-2 mm, and commercially available from Teleflex, Inc. While a braided material is exemplified for the tension tether, it will be understood that any other suitable material may be used.

[0055] In further implementations, the tension element may comprise a braided suture or another outer tubular member as described herein provided with a core member including a radiopaque core disposed within the outer tubular member, which may include a solid or braided wire or cable including a radiopaque material, or a smaller braided tether that is doped with or modified to include, for example, bismuth or other radiopaque materials.

[0056] To discuss the illustrated implant placement steps, reference is made herein to Figures 5A-7B. Figure 5A is a close-up of the image in Figure 5D, illustrating a guide catheter accessing the coronary sinus via the inferior vena cava (IVC). The navigation catheter then accesses the interstitial muscle tissue via an exit from a coronary artery branch of the coronary sinus. Figures 5B and 5E together show the navigation catheter positioned within the guide catheter moving through the interstitial space of the myocardium to form a loop around the left ventricle. The navigation catheter is then captured by a snare catheter and retracted into the guide catheter to form a complete loop. Both ends of the navigation catheter are then exteriorized. A retention tether passing through the navigation catheter is attached to the distal end of the flexible tether portion of the MIRTH implant while it is exteriorized. The MIRTH implant is then retracted into the anatomical structures surrounding the LV until both ends of the flexible tether portion of the MIRTH implant are exteriorized. A push catheter may be used to assist in pushing the MIRTH implant into place. The implant in this illustration includes a flexible body with tethers extending from each end, with both tether ends externalized to allow a limb-attached lock to be threaded over both ends of the MIRTH implant. The MIRTH implant may include a flexible loop made, for example, from a hollow braided suture with a thickened midsection that fits within the increased diameter ventricle. This can be done, for example, by inserting a solid flexible object, such as a tubular member, into the hollow tether to thicken it, or by various other techniques, as described below. In this manner, the flexible portion of the MIRTH implant may be formed from a continuous hollow suture with a thickened central section, and the portion of the tether extending beyond the lock may be empty or have minimal structural elements, such as conductive wires, within it so that it can be threaded through the lock and detached near the lock after it is deployed.Thus, as shown in Figures 5-7, the MIRTH implant is gradually introduced once a passage has been formed inside the guide catheter using a guidewire (not shown) and a navigation catheter, and optionally a support catheter, resulting in the final placement illustrated in Figures 7A and 7B.

[0057] 8-21 illustrate additional implants and associated placement methods for performing RAMIN procedures. This type of implant and placement may be used, for example, in MIRTH or SCIMITAR procedures. The following detailed description relates to examples of specific steps that may be used to establish a guidewire trajectory to create a passage for an implant as described herein, and therefore will not be described in detail here.

[0058] However, once the guidewire trajectory is established, the tension element and implant must be delivered and deployed, then shortened to alter the shape of the target myocardium. Myocardial tissue offers resistance to delivery, necessitating a combination of columnar strength, tension, and lubricity. Once delivered, the tension element can preferably be manipulated to allow it to expand in diameter and shorten in length to reduce erosion or "cheese cutting." If desired, the support catheter(s) used to assist in dilating the passage defined by the guidewire may be augmented with a saline-injectable fluid exit port to create a local pressure zone that provides hydrodissection to aid in blunt myocardial dissection and to add lubricity to assist in dilating the passage.

[0059] For ablation element thickness, start with a 0.014-0.035 inch guidewire, and then the channel is preferably expanded to accommodate an implant having a thickness of 2-3 mm. Preferably, the implant itself has length markers (e.g., radiopaque markers). Similarly, the diameter of the implant can be increased at the time of implantation, as described below. Having an implant that prevents erosion, pull-through, and myocardial laceration is of particular concern during implant delivery into tortuous myocardial trajectories, such as curves in septal-posterior SCIMITAR and anterior-reentry SCIMITAR.

[0060] For purposes of illustration and not limitation, FIG. 10 illustrates an implant including an elongated inner tether having a proximal end and a distal end. As illustrated, the proximal end of the elongated inner tether may terminate in a loop. The implant may include an outer tubular body (shown in FIGS. 10 and 11 as a thick line surrounding the looped tether) surrounding the elongated inner tether along at least a portion of the inner tether. The outer tubular body may be shorter in length than the elongated inner tether. As described below, the illustrated implant may be configured to shorten in length and increase in transit dimension when compressed axially.

[0061] As shown in Figures 8-15, the associated procedure for placing the illustrated implants typically begins with an ablation process as disclosed herein to define a passageway to receive the implant, such as by using one or more support catheters. Figures 8 and 9 illustrate a passageway defined by a support catheter (e.g., Navicross) that supports and surrounds an electrified guidewire or other ablation catheter, as described in further detail below. As shown in Figure 9, the distal ends of the guidewire and support catheter are externalized.

[0062] As shown in FIGS. 10-11 , the distal end of the tension tether within the implant's outer tubular member is then pulled through the support catheter, for example, by simply attaching the tension tether to the guidewire still present within the support catheter. The guidewire is then withdrawn through the support catheter, pulling the implant's tension tether along with it. If desired, the distal end of a "retention" tether, along with the tension tether forming the implant's core, can also be attached to the guidewire and withdrawn through the support catheter along with the tension tether. The proximal end of the retention tether can be attached to the distal end of the outer tubular member, allowing the tension tether to be withdrawn into the support catheter. However, the retention catheter pulls on the distal end of the outer tubular member, which in turn pulls the distal end of the outer tubular member into the patient's vasculature as the support catheter is withdrawn. This avoids the need to use a tension tether to pull on the outer tubular member, which can cause shortening and expansion of the outer tubular member. The outer tubular member can then be expanded by pulling on the tension tether, but does not expand while the outer tubular member is being delivered into the heart.

[0063] Thus, primarily due to tension applied by the retention catheter, the outer tubular member is then pulled against the distal end of the externalized support catheter, and the support catheter is withdrawn, pulling the implant's outer tubular member along with it. As shown in FIG. 11, the distal end of the tension tether may be routed through the proximal loop formed by its proximal end. FIGS. 12 and 13 show the loop of tension tether being pulled into the heart. As shown in FIGS. 13 and 14, the implant can then be tightened by passing a locking delivery catheter over the single tension tether, which acts as a rail. As shown in FIG. 15, the excess tether can be cut using a cutting catheter, as described, for example, in U.S. Pat. No. 10,433,962.

[0064] It is further understood that the inner tension tether of the implant embodiment of Figure 1 may similarly include a proximal loop that loops over the proximal end of the catheter used to deliver and tension the implant such that, when externalized, tension is applied to one tether end via a locking body having a single tether threaded therethrough. It is further understood that a locking body may similarly be advanced over a single tension tether, as shown in Figures 12 and 13.

[0065] Various configurations may be used to expand the diameter of the outer tubular member after it has been placed in a passageway through the heart or other anatomical structure. For example, as shown in FIG. 16, a tension tether (shown as "implant tether") may be loosely threaded in and out of the implant as the outer tubular member is being introduced. A retention tether is shown attached to the distal end of the outer tubular member. Tension is then applied to the tether after the outer tubular member is positioned.

[0066] As shown in Figures 17A-17C, the outer tubular body may include a braided structure. As shown in Figures 16, 20, and 21, in some implementations, the elongated inner tether may be threaded intermittently through the outer tubular body. More specifically, as can be seen, the elongated inner tether is threaded first across the implant, then along one side of the implant, then across the implant again in the opposite direction, then along the implant, and so on. As shown, this tether pattern may form, for example, a square wave shape, or be sinusoidal, or have a sawtooth shape. This allows the implant to be malleable and its length to change in response to cardiac activity. Specifically, because the elongated inner tether is positioned in such a way that it repeatedly crosses the implant, it will be understood that the length of the tether passing through the implant body is actually significantly longer than the implant body. Accordingly, referring to Figure 20, the implant is illustrated with the implant body at its unretracted length. As shown in FIG. 21 , as the tether is tightened, the implant's length decreases and its thickness increases. The way the tether is threaded through the implant body allows for a variety of shapes and implant body stiffnesses along the implant. For example, the implant body may be formed from a multi-layer structure including materials of different stiffness and / or thickness along the implant body. Braided layers can be formed by braiding metal or other filaments, with the braid being denser in areas not intended to flex, e.g., less braided areas. Regions of the implant with more or less braid, or areas of greater or less stiffness, can generally be aligned with the routing of the tether to facilitate axial collapse and radial expansion of the implant. Even when tightened, the tether is longer than the implant body, and the compressibility and flexibility of the implant body allow the deployed implant to bend and adjust to a useful length to accommodate the heart's movements.If desired, the implant body may be made from adjacent regions of different stiffness, such as a flexible inner layer material with discontinuous stiffer material around the inner layer that are separated from one another in a manner similar to beads on a string. When the implant is contracted, the regions of stiffer material can move toward one another, compressing the flexible inner layer between them.

[0067] In some implementations, the outer tubular body may include a resilient member. If desired, the outer tubular body may include a shape memory material, a resilient member, and / or a coil spring. In some implementations, the outer tubular body may include a plurality of radiopaque markers disposed along the outer tubular body. The plurality of radiopaque markers disposed along the outer tubular body may be spaced apart to facilitate measurement of the implant under visualization.

[0068] With respect to the MIRTH implant, the outer tubular body of the implant of FIGS. 8-21 may include at least one pacing electrode for stimulating cardiac tissue. Multiple combinations of pacing electrodes, such as four, eight, or twelve, may be used around or in portions of the heart to resynchronize the heart when there are dyssynchronous contractions caused by conduction system disease, particularly in the setting of ischemic or non-ischemic cardiomyopathy. If desired, the implant may further include a controller (e.g., embedded in the lock body) coupled to the at least one pacing electrode to provide at least one of pacing, defibrillation, measurement, and control. The implant of FIGS. 8-21 may include an antenna, such as a loop antenna, dipole antenna, monopole antenna, or helix antenna, for conducting signals to and from the controller. If desired, the implant of FIGS. 8-21 may further include a controller and a reservoir (not shown) containing a beneficial agent. The controller may be coupled to a dispenser (not shown) coupled to the reservoir for dispensing the beneficial agent. If desired, the beneficial agent may include one or more of a drug, a gene therapy material, and living cells seeded at least one location in the damaged heart. If desired, the outer tubular body of the implants of Figures 8-21 may include at least one sensor for sensing at least one biological parameter. The at least one sensor may include at least one pressure sensor for sensing blood pressure. The at least one sensor may include at least one of a chemical sensor, a distance sensor, a sensor having circuitry for detecting electrophysiological data, a motion sensor, and a position sensor. The elongate flexible tether may be a hollow braided suture, and the radiopaque material within the elongate flexible tether may include a radiopaque wire disposed within a heat-shrinkable polymer tube residing within the hollow core of the elongate inner tether.

[0069] 18 and 19, an implant is illustrated with electrodes and marker bands located along the inner tension tether portion of the implant, which shortens in length and thickens when tension is applied. As can be seen, the circuit path passes through the loop path of the inner tether and exits through the lock body, and if desired, the circuit can be completed by actuating the lock, or the circuit can be completed within the implant and simply held together with the implant by the lock.

[0070] Further according to the present disclosure, the stiffness of the limbs and outer tubular member, as well as the inner tension member, may vary along their length. For example, a portion of the limb expected to reside in the patient's septum rather than the outer wall of the heart may be provided with a different stiffness than a portion located in the outer wall of the heart. Variations in stiffness can be achieved by varying the type of material or thickness of material along the implant. Additionally or alternatively, stiffness may vary by the manner in which the implant material collapses when tension is applied to the tension tether. For example, the spacing of the undulations in the tension tether of FIG. 16 may vary along the implant, resulting in different suture frequencies per unit length of the unclamped outer tubular member in different regions of the outer tubular member.

[0071] The implant may further include an implant lock configured to secure the implant in a loop configuration. The locking function of the lock, such as by engaging the lock, completes an electrical circuit, allowing either the sensor or pacing device to be activated and / or used. For example, the inner tension tether may include various conductors or the like having an electrically insulating layer that is pierced by sharp barbs in the lock body, such as when pressure is applied to the tension tether to secure the implant in place. When pressure is applied to the conductors during the fixation process, the protrusions or barbs in the lock body pierce the insulating layer in the tether, completing the circuit.

[0072] In some implementations, advancing a guidewire through the myocardium when practicing the procedures described herein may include ablating tissue. For example, myocardial tissue may be ablated by applying electrical energy through the guidewire to energize the exposed, electrically uninsulated distal surface of the guidewire. This may typically include advancing a support catheter over the guidewire to provide additional column strength to the guidewire. The distal portion of the guidewire may include at least one visually enhanced marker that is visualized in a visualization mode. Related methods may include visualizing the guidewire and myocardium in a visualization mode during the procedure to assist in controlling the advancement of the guidewire through the myocardial tissue.

[0073] For purposes of illustration and not limitation, Figures 22A-22D are schematic diagrams of example guidewire tips according to the present disclosure. These guidewires may be used for navigation and passage through the myocardium. Once introduced into the myocardium, these guidewires can be manipulated and advanced throughout the cardiac muscle to create a range of desired trajectories for introducing other devices. This allows for adaptive electrosurgery, even when tissue planes do not readily permit passage. Monopolar or bipolar RF power may be applied at various frequencies. However, further according to the present disclosure, because different intramyocardial locations (endocardium to epicardium) exhibit characteristic unipolar and bipolar electrograms, these guidewires allow for the recording and monitoring of intramyocardial electrograms to guide navigation.

[0074] Any of the illustrated guidewires may include an elongated channel, such as a hypotube, at or near the distal tip of the guidewire to enable hydrodissection, gas dissection, or for injecting additional beneficial agents. As shown, the guidewires of FIGS. 22A-22D may include asymmetric insulation to create a tailored electromagnetic field within the myocardium. The guidewire preferably conforms to a 0.014-inch diameter form factor, has a steerable, fixed CTO curve, and is electrically insulated except for a proximal region (e.g., 10 mm) and approximately 1 mm distal region. The tip may be symmetrical (dark endpoints) as illustrated in FIG. 22A, but can be bent to allow for steering. The exposed patch may be on one side of the distal tip, as in FIG. 22B, or an asymmetric exposed patch may be located immediately proximal to the distal tip, as illustrated in FIG. 22C. FIG. 22D shows a schematic diagram of the embodiment of FIG. 22B combined with a single 0.014-inch microcatheter with a distal monopole for electrosurgical ablation. These guidewires of Figures 22A-22C can be combined into a kit with a detachable connector to a standard electrosurgical generator that allows activation of a "cut" button for continuous duty cycle RF ablation at selected operating settings.

[0075] To access the myocardium, it is typically necessary to pass a guidewire longitudinally and then laterally advance it into the tissue. An afferent access catheter may be used to provide this initial access to the myocardium. Figures 23A-23C show schematic diagrams of an exemplary, non-limiting embodiment of this device. Functionally, this catheter is used by advancing it over a guidewire to the target location so that the distal tip of the guidewire is sharply steered into the myocardium. Thus, the afferent access catheter may be made from a polymeric tubular member with a side access port for redirecting the guidewire. This may be accomplished by providing the afferent access catheter with a corrugated tip that first directs the guidewire away from the myocardium and then guides the guidewire in a 180-degree path so that it directly enters the myocardium. The afferent access catheter may include a radiopaque marker near its distal end that indicates the relative rotational position of the afferent access catheter, allowing the surgeon to determine when the correct placement of the guidewire for entry into the myocardium has been achieved. Preferably, the inner lumen of the afferent access catheter is lubricious and electrically insulated, and its outer surface is also lubricious for navigating the coronary veins. If desired, an expandable element may be provided along the side of the guide catheter opposite the guidewire exit port to provide a counteracting force against the opposing side of the lumen. Thus, the afferent access catheter is preferably advanced in parallel with the electrosurgical guidewire. An angiography port may be provided to aid in anatomical localization, and the afferent access catheter preferably has a small profile (e.g., 6-8 Fr) to accommodate larger guide catheters, such as coronary sinus balloon-tipped guide sheaths. Figure 23A shows a sketch of the guidewire path following a switchback path leading the guidewire into the myocardium. Figure 23B shows the placement of the afferent catheter relative to the LV (end view) and a side view of the catheter with the LV in the longitudinal axis. Figure 23C shows a cross-sectional view of an example catheter with a lateral guidewire exit port.

[0076] The present disclosure further provides a catheter comprising an elongate tubular member coupled to an expandable member near a distal end of the catheter and a reservoir of inflation fluid, and a collapsible snare surrounding the expandable member, wherein inflation of the expandable member with inflation fluid expands the collapsible snare. The collapsible snare may be a single-loop snare. The collapsible snare may be a multiple-loop snare. The collapsible snare may be configured to remain open after the expandable member is deflated.

[0077] Thus, a method is provided in which a snare catheter is used to position the distal end of a guidewire at a target location, the snare catheter including an expandable member disposed within the snare, and further, the snare expands upon expansion of the expandable member. This may be done to bluntly ablate surrounding tissue to create space for the snare. The balloon may be deflated after ablation is performed, after which the snare catheter can collapse to capture the guidewire and capture the guidewire. For example, this guidewire capturing step may occur within the myocardium. Alternatively, it may be accomplished outside the myocardium. The elongated passage may be at least partially formed by passing a pressurized fluid to the target location within the myocardium.

[0078] The present disclosure further provides an embodiment of a snare catheter comprising: an elongate core member having a proximal end and a distal end; an elongate intermediate tubular member having a proximal end and a distal end and defining an elongate lumen therein for slidably receiving the elongate core member therein; and a collapsible tubular lumen formed, for example, from a plurality of braided members attached from its proximal end to and from its distal end to the distal end of the elongate intermediate tubular member, wherein relative axial displacement of the distal end of the elongate intermediate tubular member toward the distal end of the elongate core member causes the collapsible tubular lumen body to expand radially outward, separating the braided members from one another, and wherein relative axial displacement of the distal end of the elongate intermediate tubular member away from the distal end of the elongate core member causes the collapsible tubular lumen body to collapse radially inward, causing the braided members to collapse together. The snare catheter further comprises a target wire disposed within the collapsible tubular lumen body, extending along the elongate core member, and having a proximal end attached to the elongate intermediate tubular member and a distal end attached to the elongate core member. The target wire may be configured to assume a first generally linear configuration when the collapsible tubular lumen body is collapsed radially inward and a second generally non-linear configuration when the collapsible tubular lumen body is expanded radially outward. The snare catheter may further comprise an elongate tubular longitudinally displaceable sheath having a proximal end and a distal end and defining a lumen for slidably receiving the elongate core member, the elongate intermediate tubular member, the collapsible tubular lumen body, and the target wire therein when the collapsible tubular lumen body is in a generally radially collapsed state. Specific embodiments of such snare catheters are described, for example, in U.S. Pat. No. 10,433,962.

[0079] If desired, the elongate core member of the snare catheter may be a tubular member defining a guidewire lumen therein. The snare catheter may include an atraumatic distal tip formed from a compliant material attached to the distal end of the elongate core member. The snare catheter (or any device described herein) may further include radiopaque marker bands disposed near the distal end of the catheter and the distal end of the elongate intermediate tubular member. If desired, the snare catheter may include a plurality of radiopaque marker bands formed on the target wire. The target wire may be at least partially formed from a radiopaque material. The collapsible tubular foraminous body may be at least partially formed from a radiopaque material.

[0080] In some implementations, the target wire may have at least one loop and / or undulation formed therein when longitudinally contracted. If desired, the target wire may have multiple loops and / or undulations formed therein when longitudinally contracted. The target wire and loops (and / or undulations) may be disposed substantially in a single plane parallel to the longitudinal axis of the catheter when the target wire is longitudinally contracted. The target wire and loops (and / or undulations) may define a three-dimensional geometric shape when the target wire is longitudinally contracted. If desired, multiple target wires may be provided, each having one or more loops and / or undulations when the target wire is longitudinally contracted. The target wire may include a composite wire, such as a wire including a core portion made from a first material and a covering portion made from a second material different from the first material.

[0081] For purposes of illustration and not limitation, FIGS. 24A-24B show a balloon snare catheter that allows for re-entry with the disclosed guidewire as it loops back, allowing for retrieval, exteriorization, and exchange of implant elements with the snare and guidewire tip embedded within the myocardium.

[0082] It is understood that capturing a guidewire in a passageway within tissue that is tense as the heart beats can be difficult. This problem can be solved by creating space using a balloon-expandable snare. This catheter can create an empty space within the myocardium by inflating the balloon to open the snare, then deflating the balloon while keeping the snare open to create space for the guidewire to enter, and then collapsing the snare to withdraw and exteriorize the tip of the guidewire. The snare may include a single or multiple loop design. The snare may include multiple straight elements that expand into a sphere or other general shape. Alternatively, the snare may include a helical wire that is generally straight when extended and expands radially when compressed, such as by rotating and / or pushing the ends of the wire together, to create a space that allows capture of the distal end of the guidewire.

[0083] In some embodiments, the present disclosure provides methods for reducing the size of a portion of a patient's heart, representative examples of which are shown with reference to Figures 25A-44.

[0084] The method includes advancing a guidewire into the patient's circulatory system and into the patient's heart, and advancing the guidewire through the myocardium to define a passage around at least a portion of the heart between an outer surface of the heart and an inner surface of the heart.

[0085] As shown in Figures 25A and 25B, the base plane is identified in a lateral projection, and in Figures 26A and 26B, the proximal CS exit zone is identified. Figures 27A and 27B illustrate electrosurgical myocardial entry, in this example using an Asahi guidewire surrounded by a Caravel microcatheter and an Astato XS20@10W. Figure 28 shows an example of dilating the tract with a 2.0 x 12 mm balloon to allow passage of a Navicross® support catheter. Figure 29 illustrates the creation of a passageway by first advancing an energized guidewire to ablate / bluntly dissect the tissue. Dissection can be facilitated by injecting pressurized fluid into the ablation site with the guidewire and microcatheter. Figure 30 shows the result of repeating this process so that the passageway approaches the anterior mesothorax. Figure 31 illustrates the passageway defined as the Asahi and Caravel catheters are advanced to the posterior septum while the Navicross support catheter remains in the anterior septum. FIG. 32 illustrates the guidewire pathway defined as the guidewire continues to define a pathway back to the LV posterior wall.

[0086] Next, as shown in Figure 33, the intermediate caravel catheter is removed, creating an annular space between the Navicross catheter and the guidewire, allowing for the introduction of a second guidewire into the Navicross. The Navicross and guide catheters are removed, and the two support catheters are reinserted over the first guidewire, parallel to the second guidewire. As shown in Figures 34A, 34B, and 35, the second guidewire is withdrawn along the passageway to the posterior wall near the point where the first guidewire entered the myocardium. A balloon catheter is introduced over this second guidewire and inflated to enlarge the passageway near the point of myocardial entry, widening the tract. Next, a snare catheter is introduced over the second guidewire and deployed to capture the distal end of the first guidewire. The distal end of the first guidewire is withdrawn and exteriorized, creating a continuous passageway within the patient, around the LV, and outside the patient's body.

[0087] With the distal end of the first guidewire externalized, the intermediate catheter (Caravel) and outer catheter (Navicross) are advanced out of the patient's body along the path of the first guidewire (Figure 38). The distal end of the guidewire is attached to the tether of the implant to be installed, and the guidewire, along with the tether, is withdrawn from the lumen of the intermediate catheter. In this example, a parallel angioplasty wire is threaded through the Navicross, which is then removed (Figure 39). Next, the tubular member (distal catheter segment) is pushed into the passage around the ventricle, and the catheter used to push the tube into position is then removed. This leaves a larger tubular member in place around the LV. Next, as shown in Figures 40A and 40B, the angioplasty wire is removed, the guide catheter is removed, and a knot is advanced over the suture until the desired tension is achieved. Excess material is cut, and Figures 41A and 41B show the MIRTH implant in place. While this example shows a prototype implant, it is preferable to use the implants of Figures 1-4 as described herein. Figures 42-44 are images of the heart removed after the procedure (on a pig heart) showing the implant in place with the tissue removed.

[0088] Generally, according to the present disclosure, it is understood that any method may further include securing a lock on the suture, then unlocking the lock, adjusting the tension of the tensioning element, and re-securing the lock. In some implementations, the method may further include delivering a beneficial agent to the target location in the patient's myocardium. In some implementations, delivering the beneficial agent may include performing a chemical ablation procedure to remove the myocardium. In some implementations, the beneficial agent may include, for example, one or more of: (i) a pharmaceutical composition, (ii) light, and (iii) ultrasound energy.

[0089] In some implementations, the elongated passage through the myocardium passes through a portion of the septum. If desired, the method may further include delivering a beneficial agent, as described elsewhere herein, to a target location in the patient's septum. If desired, delivering the beneficial agent may include performing a chemical ablation procedure to remove the septum.

[0090] In other implementations, the method may include defining an elongated passageway through a path around a portion of at least one of the patient's ventricles. If desired, the elongated passageway may pass around a portion of both of the patient's ventricles. If desired, the elongated passageway may surround the one of the patient's ventricles at a base level. In other implementations, the elongated passageway may surround the one of the patient's ventricles at a mid-level of the myocardium. If desired, the elongated passageway may surround the patient's left ventricle.

[0091] In some implementations, the method may include directing a second tension element through the patient's myocardium and applying tension to the second tension element to further alter the size of the patient's heart. For example, multiple independent elongated passages may be defined and an implant may be positioned along each passage.

[0092] Preferably, the procedures provided herein are percutaneous, and the tension element may be introduced via the patient's circulatory system. In some implementations, the procedure may include percutaneously advancing a guidewire through a wall of a cardiac blood vessel and through the myocardium to define an elongated passageway. The procedure may include advancing a guidewire through and around a wall of the blood vessel to define an elongated passageway. The blood vessel may include the abdominal aorta, and the passageway may be defined through a healthy portion of the abdominal aorta located above the aneurysm, and the method may further include coupling the tension element to an implant positioned in the abdominal aorta to prevent the implant from migrating. The implant may be positioned to at least partially or completely span a compromised region of the aorta, such as a region of the aorta containing an aneurysm.

[0093] In some implementations, the method may include directing a second tension element through the patient's myocardium and applying tension to the second tension element to further change the size of the patient's heart. For example, multiple independent elongated passages may be defined, with an implant positioned along each passage. This allows for applying forces in multiple directions through the myocardium to achieve a balance of forces to reduce the size and / or change the shape of the patient's heart. Similarly, any or all of such multiple implants may include pacing or sensor-based data collection capabilities to track and modify or treat the patient's heart while it is still beating.

[0094] In some implementations, the lock may include an electrode array coupled to a signal generator configured to provide cardiac pacing, and the method may further include performing a cardiac pacing function using the electrode array and the signal generator. The pacing function may perform depolarization of the myocardium. In some implementations, the pacing function may include synchronously depolarizing the basal left ventricle. If desired, the pacing function may include applying the pacing function to the patient's HIS bundle.

[0095] The disclosed method may include using an electrode array embedded in an implant to sense specific locations within cardiac tissue that are generating electrical signals, such as pacing signals, and then selectively ablating the tissue to, for example, alter or eliminate the specific tissue locations that generate the pacing signals. When the native tissue pacing function is eliminated, the same and / or different electrodes may be used to provide pacing signals to the cardiac tissue as needed. Electrodes may also be selectively used to detect other electrical signals generated by the cardiac tissue and depolarize the tissue. In one implementation, an implant may be implanted to pace the HIS bundle, and the implant's installed electrodes may be used to ablate tissue in the region of the AV node, after which the same or other electrodes may be used to provide pacing or other signals to the HIS bundle to achieve HIS pacing.

[0096] The systems and methods of the present disclosure, as described above and illustrated in the drawings, provide, among other things, improved techniques for cardiac remodeling. Those skilled in the art will appreciate that various modifications and variations can be made to the devices and methods of the present disclosure without departing from the spirit or scope of the present disclosure. Accordingly, the present disclosure is intended to cover modifications and variations of the subject disclosure and its equivalents.

Claims

1. 1. An implant configured to pass through a passageway defined through tissue surrounding a ventricle of the heart, comprising: a) an elongated flexible tether having opposite ends that form a loop; b) a locking body configured to releasably engage the elongate flexible tether and disposed on each end of the tether; c) first and second tubular limbs extending outwardly from the lock toward each other along the loop and on the elongated flexible tether; An implant comprising:

2. 10. The implant of claim 1, which is malleable and can change length in response to cardiac movement.

3. The implant of claim 1 , wherein the first and second tubular limbs have different diameters and have tapered distal ends.

4. 2. The implant of claim 1, wherein the distal end of the first tubular limb slides within the distal end of the second tubular limb along the loop of the elongate flexible tether such that the first and second tubular limbs overlap.

5. The implant of claim 1 , wherein at least one of the first and second tubular limbs includes a plurality of radiopaque markers therealong.

6. 10. The implant of claim 1, wherein the plurality of radiopaque markers are arranged in a predetermined pattern along the at least one of the first and second tubular limbs to facilitate measurement of the implant under visualization.

7. The implant of claim 1 , wherein at least one of the first and second tubular limbs comprises at least one pacing electrode for stimulating cardiac tissue.

8. 10. The implant of claim 7, further comprising a controller coupled to the at least one pacing electrode that provides at least one of pacing, defibrillation, measurement, and control.

9. 10. The implant of claim 8, wherein the elongated flexible tether comprises an antenna that conducts signals to and from the controller.

10. a controller and a reservoir containing a beneficial agent; the controller is coupled to a dispenser coupled to the reservoir for dispensing the beneficial agent; 10. The implant of claim 1.

11. The implant of claim 10 , wherein the beneficial agent comprises a drug.

12. The implant of claim 10 , wherein the beneficial agent comprises a gene therapy material.

13. 11. The implant of claim 10, wherein the beneficial agent comprises living cells that are seeded into at least one location of the damaged heart.

14. 10. The implant of claim 1, wherein at least one of the first and second tubular limbs comprises at least one sensor for sensing at least one biological parameter.

15. 15. The implant of claim 14, wherein the at least one sensor includes at least one pressure sensor that senses blood pressure.

16. 15. The implant of claim 14, wherein the at least one sensor comprises at least one of a chemical sensor, a distance sensor, a sensor having circuitry for detecting electrophysiological data, a motion sensor, and a position sensor.

17. The implant of claim 1 , wherein the elongate flexible tether includes a radiopaque material therealong.

18. the elongated flexible tether is a hollow braided suture; the radiopaque material within the elongate flexible tether comprises a radiopaque wire disposed within a heat-shrinkable polymer tube residing within a hollow core of the elongate inner tether; 18. The implant of claim 17.

19. 10. The implant of claim 1, wherein the electrical circuit is completed in the process of locking the locking body in place.

20. a) an elongate inner tether having a proximal end terminating in a loop and a distal end; b) an outer tubular body surrounding the elongated inner tether along at least a portion of the elongated inner tether; Equipped with The outer tubular body has a length shorter than the elongated inner tether. Implant.

21. 21. The implant of claim 20, wherein the outer tubular body is configured to shorten in length and increase in transverse dimension when compressed axially.

22. 22. The implant of claim 21, wherein the outer tubular body comprises a braided structure.

23. 22. The implant of claim 21, wherein the elongate inner tether is threaded intermittently through the outer tubular body.

24. 22. The implant of claim 21, wherein the outer tubular body comprises a resilient member.

25. 22. The implant of claim 21, wherein the outer tubular body comprises a shape memory material.

26. 22. The implant of claim 21, wherein the outer tubular body comprises a helical structural member.

27. 22. The implant of claim 21, wherein the outer tubular body comprises a coil spring.

28. 21. The implant of claim 20, wherein the outer tubular body comprises a plurality of radiopaque markers disposed therealong.

29. 30. The implant of claim 28, wherein the plurality of radiopaque markers disposed along the outer tubular body are spaced at predetermined intervals to facilitate measurement of the implant under visualization.

30. 21. The implant of claim 20, wherein the outer tubular body comprises at least one pacing electrode for stimulating cardiac tissue.

31. 31. The implant of claim 30, further comprising a controller coupled to the at least one pacing electrode that provides at least one of pacing, defibrillation, measurement, and control.

32. 32. The implant of claim 31, comprising an antenna for conducting signals to and from the controller.

33. a controller and a reservoir containing a beneficial agent; the controller is coupled to a dispenser coupled to the reservoir for dispensing a beneficial agent; 21. The implant of claim 20.

34. 34. The implant of claim 33, wherein the beneficial agent comprises one or more of a drug, a gene therapy material, and living cells seeded into at least one location of the damaged heart.

35. The implant of claim 1 , wherein the outer tubular body comprises at least one sensor for sensing at least one biological parameter.

36. 36. The implant of claim 35, wherein the at least one sensor includes at least one pressure sensor that senses blood pressure.

37. 36. The implant of claim 35, wherein the at least one sensor comprises at least one of a chemical sensor, a distance sensor, a sensor having circuitry for detecting electrophysiological data, a motion sensor, and a position sensor.

38. 21. The implant of claim 20, wherein the elongate inner tether includes radiopaque material and / or radiopaque markers therealong.

39. the elongate inner tether is a hollow braided suture; the radiopaque material within the elongate inner tether comprises a radiopaque wire disposed within a heat-shrinkable polymer tube present within a hollow core of the elongate inner tether, and / or the elongate inner tether is loaded with the radiopaque material; 39. The implant of claim 38.

40. 21. The implant of claim 20, further comprising an implant lock that secures the implant in a loop configuration.

41. 1. A method for reducing the size of a portion of a patient's heart, comprising: advancing a guidewire into the patient's circulatory system and into the patient's heart; advancing the guidewire through the myocardium to define a passage around a portion of the heart between an outer surface of the heart and an inner surface of the heart; replacing the guidewire with an implant including the tension element such that the tension element passes through the passage; advancing a lock or knot onto the tensioning element; applying tension to the tension element to change the size of the portion of the heart; securing the lock to maintain tension in the tension element; A method for providing the above.

42. Releasing the lock; adjusting the tension of the tension element; re-securing the lock; Further provided with 42. The method of claim 41.

43. 42. The method of claim 41, wherein the diameter of the tension element is greater than the diameter of the guidewire.

44. the lock comprises two elongated tubular limbs coupled to a lock body; further comprising advancing the two elongated tubular limbs along the tension element to increase the effective diameter of the tension element.

44. The method of claim 43.

45. 45. The method of claim 44, wherein the distal ends of the two elongate tubular limbs are configured to slide past each other and overlap as the tension element passes through them.

46. 46. ​​The method of claim 45, wherein a first distal end of the two elongate tubular limbs is configured to be received within a second distal end of the two elongate tubular limbs.

47. the lock comprises a limb extending therefrom that includes at least a portion of an electrode array coupled to a signal generator configured to provide cardiac pacing; performing a cardiac pacing function using the electrode array and the signal generator.

45. The method of claim 44.

48. 48. The method of claim 47, wherein the pacing function effects depolarization of the myocardium.

49. 49. The method of claim 48, wherein the pacing function comprises synchronously depolarizing the basal left ventricle.

50. 49. The method of claim 48, wherein the pacing function comprises applying a pacing function to the patient's HIS bundle.

51. 42. The method of claim 41, further comprising delivering a beneficial agent to a target location in the patient's myocardium.

52. 52. The method of claim 51, wherein delivering the beneficial agent comprises performing a chemoablation procedure to remove myocardium.

53. 42. The method of claim 41, wherein the beneficial agent comprises, for example, one or more of: (i) a pharmaceutical composition, (ii) light, and (iii) ultrasonic energy.

54. 42. The method of claim 41, wherein the elongated passageway passes through a portion of the septum.

55. 55. The method of claim 54, further comprising delivering the beneficial agent to a target location in the patient's septum.

56. The method of claim 55, wherein delivering the beneficial agent comprises at least one of: (i) performing a chemoablation procedure to remove the septum; (ii) delivering a drug to the target tissue region; (iii) delivering gene therapy material to the target tissue region; and (iv) delivering viable cells to the target tissue region that are seeded in at least one location of the damaged heart.

57. The method of claim 1 , wherein the elongated passageway follows a path around a portion of at least one ventricle of the patient.

58. The method of claim 1 , wherein the elongated passageway passes around a portion of both ventricles of the patient.

59. 58. The method of claim 57, wherein the elongated passage surrounds one ventricle of the patient at a base level.

60. 58. The method of claim 57, wherein the elongated passage surrounds one ventricle of the patient at mid-height of the myocardium.

61. 58. The method of claim 57, wherein the elongated passage surrounds the patient's left ventricle.

62. directing a second tension element through the patient's myocardium; applying tension to the second tension element through myocardial tissue to further change the size of the patient's heart; 62. The method of claim 61, further comprising:

63. the guidewire comprises an electrical conductor coated with a dielectric coating; an exposed area of ​​the conductor near the distal portion of the guidewire is not covered by the dielectric coating; the elongated passage is formed at least in part by ablating tissue by applying electrical power to the electrical conductor; 42. The method of claim 41.

64. 64. The method of claim 63, wherein the power is applied in a monopolar mode of operation.

65. the power is applied in a bipolar mode of operation; a return path for the current is defined by a second conductor disposed near the exposed region of the electrical conductor; 64. The method of claim 63.

66. 64. The method of claim 63, wherein the exposed area of ​​electrical conductor is located at a distal tip of the guidewire.

67. 64. The method of claim 63, wherein the exposed area of ​​electrical conductor is located on a side of the guidewire near the distal tip of the guidewire.

68. 64. The method of claim 63, wherein the exposed area of ​​electrical conductor is located on a side of the guidewire at the distal tip of the guidewire.

69. 64. The method of claim 63, wherein the distal end region of the guidewire comprises a bend that points away from a central longitudinal axis of the guidewire.

70. the guidewire or a support catheter supporting the guidewire defines a longitudinal channel in at least a portion thereof configured to allow fluid to exit a distal end of the longitudinal channel to facilitate tissue ablation; 64. The method of claim 63, further comprising flowing a pressurized fluid through a longitudinal channel to assist in defining the elongated passage.

71. 71. A guidewire according to any one of claims 63 to 70.

72. 72. The method of claims 41-71, wherein the elongated passage is formed at least in part by inflating an inflatable balloon coupled to a catheter positioned within the myocardium.

73. the balloon is introduced into an opening made in the myocardium by the guidewire; 73. The method of claim 72, wherein the balloon is inflated to form an enlarged entrance into the myocardium to allow introduction of at least one of the support catheters into the myocardium.

74. 73. The method of claim 72, wherein the balloon is coupled to a dilatation catheter that is at least partially slidably disposed over the guidewire.

75. 42. The method of claim 41, further comprising capturing the distal end of the guidewire with a snare catheter configured to expand to define a space that captures the guidewire therein and to collapse around the guidewire to capture the guidewire.

76. the snare catheter includes an expandable member disposed within the snare; Expansion of the expandable member expands the snare.

76. The method of claim 75.

77. 76. A catheter comprising the balloon and collapsible snare of claim 75.

78. 76. The method of claim 75, wherein the guidewire capture step occurs within the myocardium.

79. 76. The method of claim 75, wherein the guidewire capture step is accomplished outside the myocardium.

80. The method of claim 1 , wherein the elongated passage is formed at least in part by flowing a pressurized fluid to a target location within the myocardium.

81. 42. The method of claim 41, wherein advancing a guidewire through the myocardium includes advancing an afferent accessor catheter over the guidewire to help direct the guidewire into the myocardium.

82. 82. The method of claim 81, wherein the afferent accessor catheter comprises a radiopaque marker near its distal end that indicates the relative rotational position of the afferent accessor catheter.

83. Advancing a guidewire through the myocardium comprises: (a) defining a passageway by advancing the guidewire through myocardial tissue, the myocardial tissue being at least partially ablated to define the passageway, the myocardial tissue being ablated by applying electrical energy through the guidewire to energize an exposed, non-electrically insulated distal surface of the guidewire; (b) advancing a first support catheter disposed about the guidewire distally along a portion of the passageway formed during the ablation step to surround a distal portion of the guidewire and provide column strength to the guidewire; (c) repeating (a) and (b) until the passage through the myocardial tissue is completed; and 42. The method of claim 41, comprising:

84. the distal portion of the guidewire comprises at least one visually enhanced marker visible in a visualization mode; 84. The method of claim 83, comprising visualizing the guidewire and the myocardium in the visualization mode during a procedure to help control advancement of the guidewire through the myocardial tissue.

85. 84. The method of claim 83, further comprising advancing a second support catheter over the first support catheter to further enlarge the passageway.

86. 86. The method of claim 85, further comprising withdrawing the first support catheter over the guidewire, leaving the guidewire and the second support catheter in place.

87. the guidewire used to define the passageway through the myocardium is a first guidewire; further comprising advancing a second guidewire through the second support catheter parallel to the first guidewire.

87. The method of claim 86.

88. 88. The method of claim 87, comprising withdrawing the second support catheter over the first guidewire and the second guidewire.

89. 90. The method of claim 88, comprising advancing the first support catheter over the first guidewire and advancing the second support catheter over the first support catheter.

90. the passage defines a complete loop that intersects itself; the distal end of the first guidewire is advanced distally to re-enter the passageway and complete the loop.

90. The method of claim 89.

91. advancing a snare catheter over the second guidewire to a position near where the distal end of the first guidewire re-enters the passageway; actuating the snare catheter to capture the distal end of the first guidewire; withdrawing the first guidewire from the patient using the snare catheter so that the first guidewire defines a loop around the passage; 91. The method of claim 90, comprising:

92. 92. The method of claim 91, further comprising exteriorizing the proximal and distal ends of the first guidewire.

93. coupling a distal end of the tension element to a proximal end of the first guidewire; advancing the tension element around a path defined by the first guidewire until the tension element is disposed in a position that allows the lock to be introduced onto the tension element; 93. The method of claim 92, further comprising:

94. 1. A method of treating the vascular system of a patient, comprising: advancing a guidewire into the patient's circulatory system and a wall structure of the patient's vasculature; advancing the guidewire through the wall structure to define a passageway along the wall structure between an outer surface of the wall structure and an inner surface of the wall structure; exchanging the guidewire for the tension element so that the tension element passes through the passage; advancing a lock onto the tension element; tensioning the tension element; securing the lock; a method comprising:

95. 95. The method of claim 94, wherein locking the tension in place comprises advancing a knot along the tension element.

96. 95. The method of claim 94, wherein the tension element comprises a suture.

97. 96. The method of claim 95, wherein the knot is driven onto first and second ends of the tension element to form a tension loop.

98. 95. The method of claim 94, wherein advancing the lock and securing the lock comprises advancing crimps onto the first and second ends of the tension element to form the tension loop and crimping the crimps into place.

99. 95. The method of claim 94, wherein the procedure is percutaneous and the tension element is introduced via the patient's circulatory system.

100. 100. The method of claim 99, wherein the procedure comprises percutaneously advancing the guidewire through a wall of the cardiac vessel and through the myocardium to define an elongated passageway.

101. 95. The method of claim 94, comprising advancing the guidewire percutaneously through and around a wall of a blood vessel to define the elongated passage.

102. the blood vessel includes the abdominal aorta; the passageway is defined through a healthy portion of the abdominal aorta overlying the aneurysm; further comprising coupling the tension element to the implant positioned in the abdominal aorta to prevent the implant from migrating.

102. The method of claim 101.

103. 95. The method of claim 94, wherein the tension element comprises a tension tether disposed within the outer tubular member.

104. and axially shortening the outer tubular member by applying tension to the tension tether. The outer tubular member has a dimension in a passage direction that expands when contracted in an axial direction.

104. The method of claim 103.

105. Exchanging the guidewire and the tension element includes: introducing a support catheter over the guidewire; attaching a distal end of the guidewire to a distal end of the tension tether; withdrawing the tension tether through the support catheter; 104. The method of claim 103, comprising:

106. coupling a distal end of a retaining tether to the distal end of the guidewire; withdrawing the retention tether through the support catheter; 106. The method of claim 105, comprising:

107. a proximal end of the retention tether attached to a distal end of the outer tubular member; pulling the outer tubular member along a path defined by the support catheter while the support catheter is being withdrawn to position the outer tubular member at a desired anatomical location.

107. The method of claim 106.

108. directing the distal end of the tension tether through a proximal loop formed at the proximal end of the tension tether; the outer tubular member is disposed between a proximal loop at a proximal end of the outer tubular member and a point where a proximal loop at a distal end of the tension tether and a distal end of the tension tether intersect; 104. The method of claim 103.

109. 1. A guidewire comprising an electrically conductive core member surrounded by an insulating jacket, A guidewire defining an exposed, non-electrically insulated distal end surface disposed at a curved distal portion facing away from a central longitudinal axis of the proximal portion of the guidewire.

110. 110. The guidewire of claim 109, wherein the non-electrically insulated exposed distal end surface is located at the distal tip of the guidewire and is axially symmetrical about the longitudinal axis of the curved distal portion of the guidewire.

111. 110. The guidewire of claim 109, wherein the non-electrically insulated exposed distal end surface is located at the distal tip of the guidewire and is not axially symmetrical relative to the longitudinal axis of the curved distal portion of the guidewire.

112. 110. The guidewire of claim 109, wherein the non-electrically insulated exposed distal end surface is located near the distal tip of the guidewire and is not axially symmetrical about the longitudinal axis of the curved distal portion of the guidewire.

113. A catheter comprising a guidewire according to any one of claims 109 to 112 disposed within a tubular member, the tubular member including an exposed conductor at its distal end that is coupled to a conductor extending to a proximal end region of the tubular member.

114. An electrosurgical system comprising a power source operably coupled to the guidewires of the backlight 109-112 and configured to operate in a monopolar mode of operation.

115. 114. An electrosurgical system comprising a power source operably coupled to the catheter of claim 113, operating in a bipolar mode of operation and configured to complete an electrical circuit from the distal tip of the guidewire to the distal tip of the tubular member.

116. A method comprising using a guidewire according to claims 109 to 112, the method comprising detecting and processing electrical signals received from cardiac tissue.

117. 117. The method of claim 116, further comprising recording or monitoring intracardiac electrograms to assist in guiding navigation through the tissue.

118. 113. A catheter comprising a guidewire according to any one of claims 109 to 112 coupled to a hypotube which in turn is coupled to a fluid source.

119. 119. A method comprising using a catheter according to claim 118 to at least partially ablate the tissue by forcing fluid from the fluid source out the distal end of the hypotube.

120. 119. A method comprising using a catheter according to claim 118 to force saline or contrast out the distal end of the hypotube.

121. an elongated tubular member coupled to the inflatable member near the distal end of the catheter and the reservoir of inflation fluid; a collapsible snare surrounding the inflatable member; Equipped with Inflating the inflatable member with the inflation fluid expands the collapsible snare. catheter.

122. 122. The catheter of claim 121, wherein the collapsible snare is a single loop snare.

123. 122. The catheter of claim 121, wherein the collapsible snare is a multiple loop snare.

124. 122. The catheter of claim 121, wherein the collapsible snare is configured to remain open after the expandable member is deflated.

125. A tension element expandable from a first, smaller effective diameter to a second, larger effective diameter.

126. 126. The tension element of claim 125, comprising a plurality of longitudinal rails configured to separate from one another for expansion to a larger effective diameter.

127. A core member; at least one tubular member disposed about the core member to increase the effective diameter of the tension element; 126. The tension element of claim 125, comprising:

128. 126. The tension element of claim 125, further comprising a plurality of markers along the tension element that are visible under at least one visualization modality.

129. 80. The tension element of claim 79, further comprising an "L" shaped lock disposed on the first and second ends of the tension element.

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